diff options
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 3518 |
1 files changed, 2601 insertions, 917 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 26d848484912..a00808f7be6a 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Routines having to do with the 'struct sk_buff' memory handlers. * @@ -25,11 +26,6 @@ * disabled, or you better be *real* sure that the operation is atomic * with respect to whatever list is being frobbed (e.g. via lock_sock() * or via disabling bottom half handlers, etc). - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. */ /* @@ -55,6 +51,7 @@ #endif #include <linux/string.h> #include <linux/skbuff.h> +#include <linux/skbuff_ref.h> #include <linux/splice.h> #include <linux/cache.h> #include <linux/rtnetlink.h> @@ -62,28 +59,137 @@ #include <linux/scatterlist.h> #include <linux/errqueue.h> #include <linux/prefetch.h> +#include <linux/bitfield.h> #include <linux/if_vlan.h> +#include <linux/mpls.h> +#include <linux/kcov.h> +#include <linux/iov_iter.h> +#include <linux/crc32.h> #include <net/protocol.h> #include <net/dst.h> #include <net/sock.h> #include <net/checksum.h> +#include <net/gro.h> +#include <net/gso.h> +#include <net/hotdata.h> #include <net/ip6_checksum.h> #include <net/xfrm.h> +#include <net/mpls.h> +#include <net/mptcp.h> +#include <net/mctp.h> +#include <net/page_pool/helpers.h> +#include <net/psp/types.h> +#include <net/dropreason.h> +#include <net/xdp_sock.h> #include <linux/uaccess.h> #include <trace/events/skb.h> #include <linux/highmem.h> #include <linux/capability.h> #include <linux/user_namespace.h> +#include <linux/indirect_call_wrapper.h> +#include <linux/textsearch.h> + +#include "dev.h" +#include "devmem.h" +#include "netmem_priv.h" +#include "sock_destructor.h" -struct kmem_cache *skbuff_head_cache __ro_after_init; -static struct kmem_cache *skbuff_fclone_cache __ro_after_init; #ifdef CONFIG_SKB_EXTENSIONS static struct kmem_cache *skbuff_ext_cache __ro_after_init; #endif -int sysctl_max_skb_frags __read_mostly = MAX_SKB_FRAGS; -EXPORT_SYMBOL(sysctl_max_skb_frags); + +#define GRO_MAX_HEAD_PAD (GRO_MAX_HEAD + NET_SKB_PAD + NET_IP_ALIGN) +#define SKB_SMALL_HEAD_SIZE SKB_HEAD_ALIGN(max(MAX_TCP_HEADER, \ + GRO_MAX_HEAD_PAD)) + +/* We want SKB_SMALL_HEAD_CACHE_SIZE to not be a power of two. + * This should ensure that SKB_SMALL_HEAD_HEADROOM is a unique + * size, and we can differentiate heads from skb_small_head_cache + * vs system slabs by looking at their size (skb_end_offset()). + */ +#define SKB_SMALL_HEAD_CACHE_SIZE \ + (is_power_of_2(SKB_SMALL_HEAD_SIZE) ? \ + (SKB_SMALL_HEAD_SIZE + L1_CACHE_BYTES) : \ + SKB_SMALL_HEAD_SIZE) + +#define SKB_SMALL_HEAD_HEADROOM \ + SKB_WITH_OVERHEAD(SKB_SMALL_HEAD_CACHE_SIZE) + +/* kcm_write_msgs() relies on casting paged frags to bio_vec to use + * iov_iter_bvec(). These static asserts ensure the cast is valid is long as the + * netmem is a page. + */ +static_assert(offsetof(struct bio_vec, bv_page) == + offsetof(skb_frag_t, netmem)); +static_assert(sizeof_field(struct bio_vec, bv_page) == + sizeof_field(skb_frag_t, netmem)); + +static_assert(offsetof(struct bio_vec, bv_len) == offsetof(skb_frag_t, len)); +static_assert(sizeof_field(struct bio_vec, bv_len) == + sizeof_field(skb_frag_t, len)); + +static_assert(offsetof(struct bio_vec, bv_offset) == + offsetof(skb_frag_t, offset)); +static_assert(sizeof_field(struct bio_vec, bv_offset) == + sizeof_field(skb_frag_t, offset)); + +#undef FN +#define FN(reason) [SKB_DROP_REASON_##reason] = #reason, +static const char * const drop_reasons[] = { + [SKB_CONSUMED] = "CONSUMED", + DEFINE_DROP_REASON(FN, FN) +}; + +static const struct drop_reason_list drop_reasons_core = { + .reasons = drop_reasons, + .n_reasons = ARRAY_SIZE(drop_reasons), +}; + +const struct drop_reason_list __rcu * +drop_reasons_by_subsys[SKB_DROP_REASON_SUBSYS_NUM] = { + [SKB_DROP_REASON_SUBSYS_CORE] = RCU_INITIALIZER(&drop_reasons_core), +}; +EXPORT_SYMBOL(drop_reasons_by_subsys); + +/** + * drop_reasons_register_subsys - register another drop reason subsystem + * @subsys: the subsystem to register, must not be the core + * @list: the list of drop reasons within the subsystem, must point to + * a statically initialized list + */ +void drop_reasons_register_subsys(enum skb_drop_reason_subsys subsys, + const struct drop_reason_list *list) +{ + if (WARN(subsys <= SKB_DROP_REASON_SUBSYS_CORE || + subsys >= ARRAY_SIZE(drop_reasons_by_subsys), + "invalid subsystem %d\n", subsys)) + return; + + /* must point to statically allocated memory, so INIT is OK */ + RCU_INIT_POINTER(drop_reasons_by_subsys[subsys], list); +} +EXPORT_SYMBOL_GPL(drop_reasons_register_subsys); + +/** + * drop_reasons_unregister_subsys - unregister a drop reason subsystem + * @subsys: the subsystem to remove, must not be the core + * + * Note: This will synchronize_rcu() to ensure no users when it returns. + */ +void drop_reasons_unregister_subsys(enum skb_drop_reason_subsys subsys) +{ + if (WARN(subsys <= SKB_DROP_REASON_SUBSYS_CORE || + subsys >= ARRAY_SIZE(drop_reasons_by_subsys), + "invalid subsystem %d\n", subsys)) + return; + + RCU_INIT_POINTER(drop_reasons_by_subsys[subsys], NULL); + + synchronize_rcu(); +} +EXPORT_SYMBOL_GPL(drop_reasons_unregister_subsys); /** * skb_panic - private function for out-of-line support @@ -100,7 +206,7 @@ EXPORT_SYMBOL(sysctl_max_skb_frags); static void skb_panic(struct sk_buff *skb, unsigned int sz, void *addr, const char msg[]) { - pr_emerg("%s: text:%p len:%d put:%d head:%p data:%p tail:%#lx end:%#lx dev:%s\n", + pr_emerg("%s: text:%px len:%d put:%d head:%px data:%px tail:%#lx end:%#lx dev:%s\n", msg, addr, skb->len, sz, skb->head, skb->data, (unsigned long)skb->tail, (unsigned long)skb->end, skb->dev ? skb->dev->name : "<NULL>"); @@ -117,154 +223,240 @@ static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr) skb_panic(skb, sz, addr, __func__); } -/* - * kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells - * the caller if emergency pfmemalloc reserves are being used. If it is and - * the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves - * may be used. Otherwise, the packet data may be discarded until enough - * memory is free - */ -#define kmalloc_reserve(size, gfp, node, pfmemalloc) \ - __kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc) +#define NAPI_SKB_CACHE_SIZE 128 +#define NAPI_SKB_CACHE_BULK 32 +#define NAPI_SKB_CACHE_FREE 32 -static void *__kmalloc_reserve(size_t size, gfp_t flags, int node, - unsigned long ip, bool *pfmemalloc) +struct napi_alloc_cache { + local_lock_t bh_lock; + struct page_frag_cache page; + unsigned int skb_count; + void *skb_cache[NAPI_SKB_CACHE_SIZE]; +}; + +static DEFINE_PER_CPU(struct page_frag_cache, netdev_alloc_cache); +static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache) = { + .bh_lock = INIT_LOCAL_LOCK(bh_lock), +}; + +void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) { - void *obj; - bool ret_pfmemalloc = false; + struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + void *data; - /* - * Try a regular allocation, when that fails and we're not entitled - * to the reserves, fail. - */ - obj = kmalloc_node_track_caller(size, - flags | __GFP_NOMEMALLOC | __GFP_NOWARN, - node); - if (obj || !(gfp_pfmemalloc_allowed(flags))) - goto out; + fragsz = SKB_DATA_ALIGN(fragsz); - /* Try again but now we are using pfmemalloc reserves */ - ret_pfmemalloc = true; - obj = kmalloc_node_track_caller(size, flags, node); + local_lock_nested_bh(&napi_alloc_cache.bh_lock); + data = __page_frag_alloc_align(&nc->page, fragsz, + GFP_ATOMIC | __GFP_NOWARN, align_mask); + local_unlock_nested_bh(&napi_alloc_cache.bh_lock); + return data; -out: - if (pfmemalloc) - *pfmemalloc = ret_pfmemalloc; +} +EXPORT_SYMBOL(__napi_alloc_frag_align); - return obj; +void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) +{ + void *data; + + if (in_hardirq() || irqs_disabled()) { + struct page_frag_cache *nc = this_cpu_ptr(&netdev_alloc_cache); + + fragsz = SKB_DATA_ALIGN(fragsz); + data = __page_frag_alloc_align(nc, fragsz, + GFP_ATOMIC | __GFP_NOWARN, + align_mask); + } else { + local_bh_disable(); + data = __napi_alloc_frag_align(fragsz, align_mask); + local_bh_enable(); + } + return data; } +EXPORT_SYMBOL(__netdev_alloc_frag_align); -/* Allocate a new skbuff. We do this ourselves so we can fill in a few - * 'private' fields and also do memory statistics to find all the - * [BEEP] leaks. - * +/* Cache kmem_cache_size(net_hotdata.skbuff_cache) to help the compiler + * remove dead code (and skbuff_cache_size) when CONFIG_KASAN is unset. */ +static u32 skbuff_cache_size __read_mostly; + +static struct sk_buff *napi_skb_cache_get(bool alloc) +{ + struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + struct sk_buff *skb; + + local_lock_nested_bh(&napi_alloc_cache.bh_lock); + if (unlikely(!nc->skb_count)) { + if (alloc) + nc->skb_count = kmem_cache_alloc_bulk(net_hotdata.skbuff_cache, + GFP_ATOMIC | __GFP_NOWARN, + NAPI_SKB_CACHE_BULK, + nc->skb_cache); + if (unlikely(!nc->skb_count)) { + local_unlock_nested_bh(&napi_alloc_cache.bh_lock); + return NULL; + } + } + + skb = nc->skb_cache[--nc->skb_count]; + if (nc->skb_count) + prefetch(nc->skb_cache[nc->skb_count - 1]); + local_unlock_nested_bh(&napi_alloc_cache.bh_lock); + kasan_mempool_unpoison_object(skb, skbuff_cache_size); + + return skb; +} /** - * __alloc_skb - allocate a network buffer - * @size: size to allocate - * @gfp_mask: allocation mask - * @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache - * instead of head cache and allocate a cloned (child) skb. - * If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for - * allocations in case the data is required for writeback - * @node: numa node to allocate memory on + * napi_skb_cache_get_bulk - obtain a number of zeroed skb heads from the cache + * @skbs: pointer to an at least @n-sized array to fill with skb pointers + * @n: number of entries to provide * - * Allocate a new &sk_buff. The returned buffer has no headroom and a - * tail room of at least size bytes. The object has a reference count - * of one. The return is the buffer. On a failure the return is %NULL. + * Tries to obtain @n &sk_buff entries from the NAPI percpu cache and writes + * the pointers into the provided array @skbs. If there are less entries + * available, tries to replenish the cache and bulk-allocates the diff from + * the MM layer if needed. + * The heads are being zeroed with either memset() or %__GFP_ZERO, so they are + * ready for {,__}build_skb_around() and don't have any data buffers attached. + * Must be called *only* from the BH context. * - * Buffers may only be allocated from interrupts using a @gfp_mask of - * %GFP_ATOMIC. + * Return: number of successfully allocated skbs (@n if no actual allocation + * needed or kmem_cache_alloc_bulk() didn't fail). */ -struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, - int flags, int node) +u32 napi_skb_cache_get_bulk(void **skbs, u32 n) { - struct kmem_cache *cache; - struct skb_shared_info *shinfo; - struct sk_buff *skb; - u8 *data; - bool pfmemalloc; + struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + u32 bulk, total = n; + + local_lock_nested_bh(&napi_alloc_cache.bh_lock); + + if (nc->skb_count >= n) + goto get; + + /* No enough cached skbs. Try refilling the cache first */ + bulk = min(NAPI_SKB_CACHE_SIZE - nc->skb_count, NAPI_SKB_CACHE_BULK); + nc->skb_count += kmem_cache_alloc_bulk(net_hotdata.skbuff_cache, + GFP_ATOMIC | __GFP_NOWARN, bulk, + &nc->skb_cache[nc->skb_count]); + if (likely(nc->skb_count >= n)) + goto get; + + /* Still not enough. Bulk-allocate the missing part directly, zeroed */ + n -= kmem_cache_alloc_bulk(net_hotdata.skbuff_cache, + GFP_ATOMIC | __GFP_ZERO | __GFP_NOWARN, + n - nc->skb_count, &skbs[nc->skb_count]); + if (likely(nc->skb_count >= n)) + goto get; + + /* kmem_cache didn't allocate the number we need, limit the output */ + total -= n - nc->skb_count; + n = nc->skb_count; + +get: + for (u32 base = nc->skb_count - n, i = 0; i < n; i++) { + skbs[i] = nc->skb_cache[base + i]; + + kasan_mempool_unpoison_object(skbs[i], skbuff_cache_size); + memset(skbs[i], 0, offsetof(struct sk_buff, tail)); + } - cache = (flags & SKB_ALLOC_FCLONE) - ? skbuff_fclone_cache : skbuff_head_cache; + nc->skb_count -= n; + local_unlock_nested_bh(&napi_alloc_cache.bh_lock); - if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX)) - gfp_mask |= __GFP_MEMALLOC; + return total; +} +EXPORT_SYMBOL_GPL(napi_skb_cache_get_bulk); - /* Get the HEAD */ - skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node); - if (!skb) - goto out; - prefetchw(skb); +static inline void __finalize_skb_around(struct sk_buff *skb, void *data, + unsigned int size) +{ + struct skb_shared_info *shinfo; - /* We do our best to align skb_shared_info on a separate cache - * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives - * aligned memory blocks, unless SLUB/SLAB debug is enabled. - * Both skb->head and skb_shared_info are cache line aligned. - */ - size = SKB_DATA_ALIGN(size); - size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); - if (!data) - goto nodata; - /* kmalloc(size) might give us more room than requested. - * Put skb_shared_info exactly at the end of allocated zone, - * to allow max possible filling before reallocation. - */ - size = SKB_WITH_OVERHEAD(ksize(data)); - prefetchw(data + size); + size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - /* - * Only clear those fields we need to clear, not those that we will - * actually initialise below. Hence, don't put any more fields after - * the tail pointer in struct sk_buff! - */ - memset(skb, 0, offsetof(struct sk_buff, tail)); - /* Account for allocated memory : skb + skb->head */ + /* Assumes caller memset cleared SKB */ skb->truesize = SKB_TRUESIZE(size); - skb->pfmemalloc = pfmemalloc; refcount_set(&skb->users, 1); skb->head = data; skb->data = data; skb_reset_tail_pointer(skb); - skb->end = skb->tail + size; + skb_set_end_offset(skb, size); skb->mac_header = (typeof(skb->mac_header))~0U; skb->transport_header = (typeof(skb->transport_header))~0U; - + skb->alloc_cpu = raw_smp_processor_id(); /* make sure we initialize shinfo sequentially */ shinfo = skb_shinfo(skb); memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); atomic_set(&shinfo->dataref, 1); - if (flags & SKB_ALLOC_FCLONE) { - struct sk_buff_fclones *fclones; + skb_set_kcov_handle(skb, kcov_common_handle()); +} - fclones = container_of(skb, struct sk_buff_fclones, skb1); +static inline void *__slab_build_skb(void *data, unsigned int *size) +{ + void *resized; - skb->fclone = SKB_FCLONE_ORIG; - refcount_set(&fclones->fclone_ref, 1); + /* Must find the allocation size (and grow it to match). */ + *size = ksize(data); + /* krealloc() will immediately return "data" when + * "ksize(data)" is requested: it is the existing upper + * bounds. As a result, GFP_ATOMIC will be ignored. Note + * that this "new" pointer needs to be passed back to the + * caller for use so the __alloc_size hinting will be + * tracked correctly. + */ + resized = krealloc(data, *size, GFP_ATOMIC); + WARN_ON_ONCE(resized != data); + return resized; +} + +/* build_skb() variant which can operate on slab buffers. + * Note that this should be used sparingly as slab buffers + * cannot be combined efficiently by GRO! + */ +struct sk_buff *slab_build_skb(void *data) +{ + struct sk_buff *skb; + unsigned int size; + + skb = kmem_cache_alloc(net_hotdata.skbuff_cache, + GFP_ATOMIC | __GFP_NOWARN); + if (unlikely(!skb)) + return NULL; + + memset(skb, 0, offsetof(struct sk_buff, tail)); + data = __slab_build_skb(data, &size); + __finalize_skb_around(skb, data, size); - fclones->skb2.fclone = SKB_FCLONE_CLONE; - } -out: return skb; -nodata: - kmem_cache_free(cache, skb); - skb = NULL; - goto out; } -EXPORT_SYMBOL(__alloc_skb); +EXPORT_SYMBOL(slab_build_skb); + +/* Caller must provide SKB that is memset cleared */ +static void __build_skb_around(struct sk_buff *skb, void *data, + unsigned int frag_size) +{ + unsigned int size = frag_size; + + /* frag_size == 0 is considered deprecated now. Callers + * using slab buffer should use slab_build_skb() instead. + */ + if (WARN_ONCE(size == 0, "Use slab_build_skb() instead")) + data = __slab_build_skb(data, &size); + + __finalize_skb_around(skb, data, size); +} /** * __build_skb - build a network buffer * @data: data buffer provided by caller - * @frag_size: size of data, or 0 if head was kmalloced + * @frag_size: size of data (must not be 0) * * Allocate a new &sk_buff. Caller provides space holding head and - * skb_shared_info. @data must have been allocated by kmalloc() only if - * @frag_size is 0, otherwise data should come from the page allocator - * or vmalloc() + * skb_shared_info. @data must have been allocated from the page + * allocator or vmalloc(). (A @frag_size of 0 to indicate a kmalloc() + * allocation is deprecated, and callers should use slab_build_skb() + * instead.) * The return is the new skb buffer. * On a failure the return is %NULL, and @data is not freed. * Notes : @@ -277,101 +469,258 @@ EXPORT_SYMBOL(__alloc_skb); */ struct sk_buff *__build_skb(void *data, unsigned int frag_size) { - struct skb_shared_info *shinfo; struct sk_buff *skb; - unsigned int size = frag_size ? : ksize(data); - skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); - if (!skb) + skb = kmem_cache_alloc(net_hotdata.skbuff_cache, + GFP_ATOMIC | __GFP_NOWARN); + if (unlikely(!skb)) return NULL; - size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - memset(skb, 0, offsetof(struct sk_buff, tail)); - skb->truesize = SKB_TRUESIZE(size); - refcount_set(&skb->users, 1); - skb->head = data; - skb->data = data; - skb_reset_tail_pointer(skb); - skb->end = skb->tail + size; - skb->mac_header = (typeof(skb->mac_header))~0U; - skb->transport_header = (typeof(skb->transport_header))~0U; - - /* make sure we initialize shinfo sequentially */ - shinfo = skb_shinfo(skb); - memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); - atomic_set(&shinfo->dataref, 1); + __build_skb_around(skb, data, frag_size); return skb; } /* build_skb() is wrapper over __build_skb(), that specifically * takes care of skb->head and skb->pfmemalloc - * This means that if @frag_size is not zero, then @data must be backed - * by a page fragment, not kmalloc() or vmalloc() */ struct sk_buff *build_skb(void *data, unsigned int frag_size) { struct sk_buff *skb = __build_skb(data, frag_size); - if (skb && frag_size) { + if (likely(skb && frag_size)) { skb->head_frag = 1; - if (page_is_pfmemalloc(virt_to_head_page(data))) - skb->pfmemalloc = 1; + skb_propagate_pfmemalloc(virt_to_head_page(data), skb); } return skb; } EXPORT_SYMBOL(build_skb); -#define NAPI_SKB_CACHE_SIZE 64 +/** + * build_skb_around - build a network buffer around provided skb + * @skb: sk_buff provide by caller, must be memset cleared + * @data: data buffer provided by caller + * @frag_size: size of data + */ +struct sk_buff *build_skb_around(struct sk_buff *skb, + void *data, unsigned int frag_size) +{ + if (unlikely(!skb)) + return NULL; -struct napi_alloc_cache { - struct page_frag_cache page; - unsigned int skb_count; - void *skb_cache[NAPI_SKB_CACHE_SIZE]; -}; + __build_skb_around(skb, data, frag_size); -static DEFINE_PER_CPU(struct page_frag_cache, netdev_alloc_cache); -static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache); + if (frag_size) { + skb->head_frag = 1; + skb_propagate_pfmemalloc(virt_to_head_page(data), skb); + } + return skb; +} +EXPORT_SYMBOL(build_skb_around); -static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask) +/** + * __napi_build_skb - build a network buffer + * @data: data buffer provided by caller + * @frag_size: size of data + * + * Version of __build_skb() that uses NAPI percpu caches to obtain + * skbuff_head instead of inplace allocation. + * + * Returns a new &sk_buff on success, %NULL on allocation failure. + */ +static struct sk_buff *__napi_build_skb(void *data, unsigned int frag_size) { - struct page_frag_cache *nc; - unsigned long flags; - void *data; + struct sk_buff *skb; - local_irq_save(flags); - nc = this_cpu_ptr(&netdev_alloc_cache); - data = page_frag_alloc(nc, fragsz, gfp_mask); - local_irq_restore(flags); - return data; + skb = napi_skb_cache_get(true); + if (unlikely(!skb)) + return NULL; + + memset(skb, 0, offsetof(struct sk_buff, tail)); + __build_skb_around(skb, data, frag_size); + + return skb; } /** - * netdev_alloc_frag - allocate a page fragment - * @fragsz: fragment size + * napi_build_skb - build a network buffer + * @data: data buffer provided by caller + * @frag_size: size of data + * + * Version of __napi_build_skb() that takes care of skb->head_frag + * and skb->pfmemalloc when the data is a page or page fragment. * - * Allocates a frag from a page for receive buffer. - * Uses GFP_ATOMIC allocations. + * Returns a new &sk_buff on success, %NULL on allocation failure. */ -void *netdev_alloc_frag(unsigned int fragsz) +struct sk_buff *napi_build_skb(void *data, unsigned int frag_size) { - return __netdev_alloc_frag(fragsz, GFP_ATOMIC); + struct sk_buff *skb = __napi_build_skb(data, frag_size); + + if (likely(skb) && frag_size) { + skb->head_frag = 1; + skb_propagate_pfmemalloc(virt_to_head_page(data), skb); + } + + return skb; } -EXPORT_SYMBOL(netdev_alloc_frag); +EXPORT_SYMBOL(napi_build_skb); -static void *__napi_alloc_frag(unsigned int fragsz, gfp_t gfp_mask) +/* + * kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells + * the caller if emergency pfmemalloc reserves are being used. If it is and + * the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves + * may be used. Otherwise, the packet data may be discarded until enough + * memory is free + */ +static void *kmalloc_reserve(unsigned int *size, gfp_t flags, int node, + bool *pfmemalloc) { - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + bool ret_pfmemalloc = false; + size_t obj_size; + void *obj; - return page_frag_alloc(&nc->page, fragsz, gfp_mask); + obj_size = SKB_HEAD_ALIGN(*size); + if (obj_size <= SKB_SMALL_HEAD_CACHE_SIZE && + !(flags & KMALLOC_NOT_NORMAL_BITS)) { + obj = kmem_cache_alloc_node(net_hotdata.skb_small_head_cache, + flags | __GFP_NOMEMALLOC | __GFP_NOWARN, + node); + *size = SKB_SMALL_HEAD_CACHE_SIZE; + if (obj || !(gfp_pfmemalloc_allowed(flags))) + goto out; + /* Try again but now we are using pfmemalloc reserves */ + ret_pfmemalloc = true; + obj = kmem_cache_alloc_node(net_hotdata.skb_small_head_cache, flags, node); + goto out; + } + + obj_size = kmalloc_size_roundup(obj_size); + /* The following cast might truncate high-order bits of obj_size, this + * is harmless because kmalloc(obj_size >= 2^32) will fail anyway. + */ + *size = (unsigned int)obj_size; + + /* + * Try a regular allocation, when that fails and we're not entitled + * to the reserves, fail. + */ + obj = kmalloc_node_track_caller(obj_size, + flags | __GFP_NOMEMALLOC | __GFP_NOWARN, + node); + if (obj || !(gfp_pfmemalloc_allowed(flags))) + goto out; + + /* Try again but now we are using pfmemalloc reserves */ + ret_pfmemalloc = true; + obj = kmalloc_node_track_caller(obj_size, flags, node); + +out: + if (pfmemalloc) + *pfmemalloc = ret_pfmemalloc; + + return obj; } -void *napi_alloc_frag(unsigned int fragsz) +/* Allocate a new skbuff. We do this ourselves so we can fill in a few + * 'private' fields and also do memory statistics to find all the + * [BEEP] leaks. + * + */ + +/** + * __alloc_skb - allocate a network buffer + * @size: size to allocate + * @gfp_mask: allocation mask + * @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache + * instead of head cache and allocate a cloned (child) skb. + * If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for + * allocations in case the data is required for writeback + * @node: numa node to allocate memory on + * + * Allocate a new &sk_buff. The returned buffer has no headroom and a + * tail room of at least size bytes. The object has a reference count + * of one. The return is the buffer. On a failure the return is %NULL. + * + * Buffers may only be allocated from interrupts using a @gfp_mask of + * %GFP_ATOMIC. + */ +struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, + int flags, int node) { - return __napi_alloc_frag(fragsz, GFP_ATOMIC); + struct sk_buff *skb = NULL; + struct kmem_cache *cache; + bool pfmemalloc; + u8 *data; + + if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX)) + gfp_mask |= __GFP_MEMALLOC; + + if (flags & SKB_ALLOC_FCLONE) { + cache = net_hotdata.skbuff_fclone_cache; + goto fallback; + } + cache = net_hotdata.skbuff_cache; + if (unlikely(node != NUMA_NO_NODE && node != numa_mem_id())) + goto fallback; + + if (flags & SKB_ALLOC_NAPI) { + skb = napi_skb_cache_get(true); + if (unlikely(!skb)) + return NULL; + } else if (!in_hardirq() && !irqs_disabled()) { + local_bh_disable(); + skb = napi_skb_cache_get(false); + local_bh_enable(); + } + + if (!skb) { +fallback: + skb = kmem_cache_alloc_node(cache, gfp_mask & ~GFP_DMA, node); + if (unlikely(!skb)) + return NULL; + } + prefetchw(skb); + + /* We do our best to align skb_shared_info on a separate cache + * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives + * aligned memory blocks, unless SLUB/SLAB debug is enabled. + * Both skb->head and skb_shared_info are cache line aligned. + */ + data = kmalloc_reserve(&size, gfp_mask, node, &pfmemalloc); + if (unlikely(!data)) + goto nodata; + /* kmalloc_size_roundup() might give us more room than requested. + * Put skb_shared_info exactly at the end of allocated zone, + * to allow max possible filling before reallocation. + */ + prefetchw(data + SKB_WITH_OVERHEAD(size)); + + /* + * Only clear those fields we need to clear, not those that we will + * actually initialise below. Hence, don't put any more fields after + * the tail pointer in struct sk_buff! + */ + memset(skb, 0, offsetof(struct sk_buff, tail)); + __build_skb_around(skb, data, size); + skb->pfmemalloc = pfmemalloc; + + if (flags & SKB_ALLOC_FCLONE) { + struct sk_buff_fclones *fclones; + + fclones = container_of(skb, struct sk_buff_fclones, skb1); + + skb->fclone = SKB_FCLONE_ORIG; + refcount_set(&fclones->fclone_ref, 1); + } + + return skb; + +nodata: + kmem_cache_free(cache, skb); + return NULL; } -EXPORT_SYMBOL(napi_alloc_frag); +EXPORT_SYMBOL(__alloc_skb); /** * __netdev_alloc_skb - allocate an skbuff for rx on a specific device @@ -390,14 +739,17 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, gfp_t gfp_mask) { struct page_frag_cache *nc; - unsigned long flags; struct sk_buff *skb; bool pfmemalloc; void *data; len += NET_SKB_PAD; - if ((len > SKB_WITH_OVERHEAD(PAGE_SIZE)) || + /* If requested length is either too small or too big, + * we use kmalloc() for skb->head allocation. + */ + if (len <= SKB_WITH_OVERHEAD(SKB_SMALL_HEAD_CACHE_SIZE) || + len > SKB_WITH_OVERHEAD(PAGE_SIZE) || (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE); if (!skb) @@ -405,19 +757,26 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, goto skb_success; } - len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - len = SKB_DATA_ALIGN(len); + len = SKB_HEAD_ALIGN(len); if (sk_memalloc_socks()) gfp_mask |= __GFP_MEMALLOC; - local_irq_save(flags); + if (in_hardirq() || irqs_disabled()) { + nc = this_cpu_ptr(&netdev_alloc_cache); + data = page_frag_alloc(nc, len, gfp_mask); + pfmemalloc = page_frag_cache_is_pfmemalloc(nc); + } else { + local_bh_disable(); + local_lock_nested_bh(&napi_alloc_cache.bh_lock); - nc = this_cpu_ptr(&netdev_alloc_cache); - data = page_frag_alloc(nc, len, gfp_mask); - pfmemalloc = nc->pfmemalloc; + nc = this_cpu_ptr(&napi_alloc_cache.page); + data = page_frag_alloc(nc, len, gfp_mask); + pfmemalloc = page_frag_cache_is_pfmemalloc(nc); - local_irq_restore(flags); + local_unlock_nested_bh(&napi_alloc_cache.bh_lock); + local_bh_enable(); + } if (unlikely(!data)) return NULL; @@ -428,7 +787,6 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, return NULL; } - /* use OR instead of assignment to avoid clearing of bits in mask */ if (pfmemalloc) skb->pfmemalloc = 1; skb->head_frag = 1; @@ -443,10 +801,9 @@ skb_fail: EXPORT_SYMBOL(__netdev_alloc_skb); /** - * __napi_alloc_skb - allocate skbuff for rx in a specific NAPI instance + * napi_alloc_skb - allocate skbuff for rx in a specific NAPI instance * @napi: napi instance this buffer was allocated for * @len: length to allocate - * @gfp_mask: get_free_pages mask, passed to alloc_skb and alloc_pages * * Allocate a new sk_buff for use in NAPI receive. This buffer will * attempt to allocate the head from a special reserved region used @@ -455,41 +812,52 @@ EXPORT_SYMBOL(__netdev_alloc_skb); * * %NULL is returned if there is no free memory. */ -struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, - gfp_t gfp_mask) +struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int len) { - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + gfp_t gfp_mask = GFP_ATOMIC | __GFP_NOWARN; + struct napi_alloc_cache *nc; struct sk_buff *skb; + bool pfmemalloc; void *data; + DEBUG_NET_WARN_ON_ONCE(!in_softirq()); len += NET_SKB_PAD + NET_IP_ALIGN; - if ((len > SKB_WITH_OVERHEAD(PAGE_SIZE)) || + /* If requested length is either too small or too big, + * we use kmalloc() for skb->head allocation. + */ + if (len <= SKB_WITH_OVERHEAD(SKB_SMALL_HEAD_CACHE_SIZE) || + len > SKB_WITH_OVERHEAD(PAGE_SIZE) || (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { - skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE); + skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX | SKB_ALLOC_NAPI, + NUMA_NO_NODE); if (!skb) goto skb_fail; goto skb_success; } - len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - len = SKB_DATA_ALIGN(len); + len = SKB_HEAD_ALIGN(len); if (sk_memalloc_socks()) gfp_mask |= __GFP_MEMALLOC; + local_lock_nested_bh(&napi_alloc_cache.bh_lock); + nc = this_cpu_ptr(&napi_alloc_cache); + data = page_frag_alloc(&nc->page, len, gfp_mask); + pfmemalloc = page_frag_cache_is_pfmemalloc(&nc->page); + local_unlock_nested_bh(&napi_alloc_cache.bh_lock); + if (unlikely(!data)) return NULL; - skb = __build_skb(data, len); + skb = __napi_build_skb(data, len); if (unlikely(!skb)) { skb_free_frag(data); return NULL; } - /* use OR instead of assignment to avoid clearing of bits in mask */ - if (nc->page.pfmemalloc) + if (pfmemalloc) skb->pfmemalloc = 1; skb->head_frag = 1; @@ -500,23 +868,27 @@ skb_success: skb_fail: return skb; } -EXPORT_SYMBOL(__napi_alloc_skb); +EXPORT_SYMBOL(napi_alloc_skb); -void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, - int size, unsigned int truesize) +void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, netmem_ref netmem, + int off, int size, unsigned int truesize) { - skb_fill_page_desc(skb, i, page, off, size); + DEBUG_NET_WARN_ON_ONCE(size > truesize); + + skb_fill_netmem_desc(skb, i, netmem, off, size); skb->len += size; skb->data_len += size; skb->truesize += truesize; } -EXPORT_SYMBOL(skb_add_rx_frag); +EXPORT_SYMBOL(skb_add_rx_frag_netmem); void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, unsigned int truesize) { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + DEBUG_NET_WARN_ON_ONCE(size > truesize); + skb_frag_size_add(frag, size); skb->len += size; skb->data_len += size; @@ -543,34 +915,207 @@ static void skb_clone_fraglist(struct sk_buff *skb) skb_get(list); } +int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb, + unsigned int headroom) +{ +#if IS_ENABLED(CONFIG_PAGE_POOL) + u32 size, truesize, len, max_head_size, off; + struct sk_buff *skb = *pskb, *nskb; + int err, i, head_off; + void *data; + + /* XDP does not support fraglist so we need to linearize + * the skb. + */ + if (skb_has_frag_list(skb)) + return -EOPNOTSUPP; + + max_head_size = SKB_WITH_OVERHEAD(PAGE_SIZE - headroom); + if (skb->len > max_head_size + MAX_SKB_FRAGS * PAGE_SIZE) + return -ENOMEM; + + size = min_t(u32, skb->len, max_head_size); + truesize = SKB_HEAD_ALIGN(size) + headroom; + data = page_pool_dev_alloc_va(pool, &truesize); + if (!data) + return -ENOMEM; + + nskb = napi_build_skb(data, truesize); + if (!nskb) { + page_pool_free_va(pool, data, true); + return -ENOMEM; + } + + skb_reserve(nskb, headroom); + skb_copy_header(nskb, skb); + skb_mark_for_recycle(nskb); + + err = skb_copy_bits(skb, 0, nskb->data, size); + if (err) { + consume_skb(nskb); + return err; + } + skb_put(nskb, size); + + head_off = skb_headroom(nskb) - skb_headroom(skb); + skb_headers_offset_update(nskb, head_off); + + off = size; + len = skb->len - off; + for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) { + struct page *page; + u32 page_off; + + size = min_t(u32, len, PAGE_SIZE); + truesize = size; + + page = page_pool_dev_alloc(pool, &page_off, &truesize); + if (!page) { + consume_skb(nskb); + return -ENOMEM; + } + + skb_add_rx_frag(nskb, i, page, page_off, size, truesize); + err = skb_copy_bits(skb, off, page_address(page) + page_off, + size); + if (err) { + consume_skb(nskb); + return err; + } + + len -= size; + off += size; + } + + consume_skb(skb); + *pskb = nskb; + + return 0; +#else + return -EOPNOTSUPP; +#endif +} +EXPORT_SYMBOL(skb_pp_cow_data); + +int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb, + const struct bpf_prog *prog) +{ + if (!prog->aux->xdp_has_frags) + return -EINVAL; + + return skb_pp_cow_data(pool, pskb, XDP_PACKET_HEADROOM); +} +EXPORT_SYMBOL(skb_cow_data_for_xdp); + +#if IS_ENABLED(CONFIG_PAGE_POOL) +bool napi_pp_put_page(netmem_ref netmem) +{ + netmem = netmem_compound_head(netmem); + + if (unlikely(!netmem_is_pp(netmem))) + return false; + + page_pool_put_full_netmem(netmem_get_pp(netmem), netmem, false); + + return true; +} +EXPORT_SYMBOL(napi_pp_put_page); +#endif + +static bool skb_pp_recycle(struct sk_buff *skb, void *data) +{ + if (!IS_ENABLED(CONFIG_PAGE_POOL) || !skb->pp_recycle) + return false; + return napi_pp_put_page(page_to_netmem(virt_to_page(data))); +} + +/** + * skb_pp_frag_ref() - Increase fragment references of a page pool aware skb + * @skb: page pool aware skb + * + * Increase the fragment reference count (pp_ref_count) of a skb. This is + * intended to gain fragment references only for page pool aware skbs, + * i.e. when skb->pp_recycle is true, and not for fragments in a + * non-pp-recycling skb. It has a fallback to increase references on normal + * pages, as page pool aware skbs may also have normal page fragments. + */ +static int skb_pp_frag_ref(struct sk_buff *skb) +{ + struct skb_shared_info *shinfo; + netmem_ref head_netmem; + int i; + + if (!skb->pp_recycle) + return -EINVAL; + + shinfo = skb_shinfo(skb); + + for (i = 0; i < shinfo->nr_frags; i++) { + head_netmem = netmem_compound_head(shinfo->frags[i].netmem); + if (likely(netmem_is_pp(head_netmem))) + page_pool_ref_netmem(head_netmem); + else + page_ref_inc(netmem_to_page(head_netmem)); + } + return 0; +} + +static void skb_kfree_head(void *head, unsigned int end_offset) +{ + if (end_offset == SKB_SMALL_HEAD_HEADROOM) + kmem_cache_free(net_hotdata.skb_small_head_cache, head); + else + kfree(head); +} + static void skb_free_head(struct sk_buff *skb) { unsigned char *head = skb->head; - if (skb->head_frag) + if (skb->head_frag) { + if (skb_pp_recycle(skb, head)) + return; skb_free_frag(head); - else - kfree(head); + } else { + skb_kfree_head(head, skb_end_offset(skb)); + } } -static void skb_release_data(struct sk_buff *skb) +static void skb_release_data(struct sk_buff *skb, enum skb_drop_reason reason) { struct skb_shared_info *shinfo = skb_shinfo(skb); int i; - if (skb->cloned && - atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1, - &shinfo->dataref)) - return; + if (!skb_data_unref(skb, shinfo)) + goto exit; + + if (skb_zcopy(skb)) { + bool skip_unref = shinfo->flags & SKBFL_MANAGED_FRAG_REFS; + + skb_zcopy_clear(skb, true); + if (skip_unref) + goto free_head; + } for (i = 0; i < shinfo->nr_frags; i++) - __skb_frag_unref(&shinfo->frags[i]); + __skb_frag_unref(&shinfo->frags[i], skb->pp_recycle); +free_head: if (shinfo->frag_list) - kfree_skb_list(shinfo->frag_list); + kfree_skb_list_reason(shinfo->frag_list, reason); - skb_zcopy_clear(skb, true); skb_free_head(skb); +exit: + /* When we clone an SKB we copy the reycling bit. The pp_recycle + * bit is only set on the head though, so in order to avoid races + * while trying to recycle fragments on __skb_frag_unref() we need + * to make one SKB responsible for triggering the recycle path. + * So disable the recycling bit if an SKB is cloned and we have + * additional references to the fragmented part of the SKB. + * Eventually the last SKB will have the recycling bit set and it's + * dataref set to 0, which will trigger the recycling + */ + skb->pp_recycle = 0; } /* @@ -582,7 +1127,7 @@ static void kfree_skbmem(struct sk_buff *skb) switch (skb->fclone) { case SKB_FCLONE_UNAVAILABLE: - kmem_cache_free(skbuff_head_cache, skb); + kmem_cache_free(net_hotdata.skbuff_cache, skb); return; case SKB_FCLONE_ORIG: @@ -603,28 +1148,38 @@ static void kfree_skbmem(struct sk_buff *skb) if (!refcount_dec_and_test(&fclones->fclone_ref)) return; fastpath: - kmem_cache_free(skbuff_fclone_cache, fclones); + kmem_cache_free(net_hotdata.skbuff_fclone_cache, fclones); } void skb_release_head_state(struct sk_buff *skb) { skb_dst_drop(skb); if (skb->destructor) { - WARN_ON(in_irq()); - skb->destructor(skb); - } -#if IS_ENABLED(CONFIG_NF_CONNTRACK) - nf_conntrack_put(skb_nfct(skb)); + DEBUG_NET_WARN_ON_ONCE(in_hardirq()); +#ifdef CONFIG_INET + INDIRECT_CALL_4(skb->destructor, + tcp_wfree, __sock_wfree, sock_wfree, + xsk_destruct_skb, + skb); +#else + INDIRECT_CALL_2(skb->destructor, + sock_wfree, xsk_destruct_skb, + skb); + #endif - skb_ext_put(skb); + skb->destructor = NULL; + skb->sk = NULL; + } + nf_reset_ct(skb); + skb_ext_reset(skb); } /* Free everything but the sk_buff shell. */ -static void skb_release_all(struct sk_buff *skb) +static void skb_release_all(struct sk_buff *skb, enum skb_drop_reason reason) { skb_release_head_state(skb); if (likely(skb->head)) - skb_release_data(skb); + skb_release_data(skb, reason); } /** @@ -638,38 +1193,206 @@ static void skb_release_all(struct sk_buff *skb) void __kfree_skb(struct sk_buff *skb) { - skb_release_all(skb); + skb_release_all(skb, SKB_DROP_REASON_NOT_SPECIFIED); kfree_skbmem(skb); } EXPORT_SYMBOL(__kfree_skb); +static __always_inline +bool __sk_skb_reason_drop(struct sock *sk, struct sk_buff *skb, + enum skb_drop_reason reason) +{ + if (unlikely(!skb_unref(skb))) + return false; + + DEBUG_NET_WARN_ON_ONCE(reason == SKB_NOT_DROPPED_YET || + u32_get_bits(reason, + SKB_DROP_REASON_SUBSYS_MASK) >= + SKB_DROP_REASON_SUBSYS_NUM); + + if (reason == SKB_CONSUMED) + trace_consume_skb(skb, __builtin_return_address(0)); + else + trace_kfree_skb(skb, __builtin_return_address(0), reason, sk); + return true; +} + /** - * kfree_skb - free an sk_buff + * sk_skb_reason_drop - free an sk_buff with special reason + * @sk: the socket to receive @skb, or NULL if not applicable * @skb: buffer to free + * @reason: reason why this skb is dropped * - * Drop a reference to the buffer and free it if the usage count has - * hit zero. + * Drop a reference to the buffer and free it if the usage count has hit + * zero. Meanwhile, pass the receiving socket and drop reason to + * 'kfree_skb' tracepoint. */ -void kfree_skb(struct sk_buff *skb) +void __fix_address +sk_skb_reason_drop(struct sock *sk, struct sk_buff *skb, enum skb_drop_reason reason) { - if (!skb_unref(skb)) + if (__sk_skb_reason_drop(sk, skb, reason)) + __kfree_skb(skb); +} +EXPORT_SYMBOL(sk_skb_reason_drop); + +#define KFREE_SKB_BULK_SIZE 16 + +struct skb_free_array { + unsigned int skb_count; + void *skb_array[KFREE_SKB_BULK_SIZE]; +}; + +static void kfree_skb_add_bulk(struct sk_buff *skb, + struct skb_free_array *sa, + enum skb_drop_reason reason) +{ + /* if SKB is a clone, don't handle this case */ + if (unlikely(skb->fclone != SKB_FCLONE_UNAVAILABLE)) { + __kfree_skb(skb); return; + } - trace_kfree_skb(skb, __builtin_return_address(0)); - __kfree_skb(skb); + skb_release_all(skb, reason); + sa->skb_array[sa->skb_count++] = skb; + + if (unlikely(sa->skb_count == KFREE_SKB_BULK_SIZE)) { + kmem_cache_free_bulk(net_hotdata.skbuff_cache, KFREE_SKB_BULK_SIZE, + sa->skb_array); + sa->skb_count = 0; + } } -EXPORT_SYMBOL(kfree_skb); -void kfree_skb_list(struct sk_buff *segs) +void __fix_address +kfree_skb_list_reason(struct sk_buff *segs, enum skb_drop_reason reason) { + struct skb_free_array sa; + + sa.skb_count = 0; + while (segs) { struct sk_buff *next = segs->next; - kfree_skb(segs); + if (__sk_skb_reason_drop(NULL, segs, reason)) { + skb_poison_list(segs); + kfree_skb_add_bulk(segs, &sa, reason); + } + segs = next; } + + if (sa.skb_count) + kmem_cache_free_bulk(net_hotdata.skbuff_cache, sa.skb_count, sa.skb_array); +} +EXPORT_SYMBOL(kfree_skb_list_reason); + +/* Dump skb information and contents. + * + * Must only be called from net_ratelimit()-ed paths. + * + * Dumps whole packets if full_pkt, only headers otherwise. + */ +void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt) +{ + struct skb_shared_info *sh = skb_shinfo(skb); + struct net_device *dev = skb->dev; + struct sock *sk = skb->sk; + struct sk_buff *list_skb; + bool has_mac, has_trans; + int headroom, tailroom; + int i, len, seg_len; + + if (full_pkt) + len = skb->len; + else + len = min_t(int, skb->len, MAX_HEADER + 128); + + headroom = skb_headroom(skb); + tailroom = skb_tailroom(skb); + + has_mac = skb_mac_header_was_set(skb); + has_trans = skb_transport_header_was_set(skb); + + printk("%sskb len=%u headroom=%u headlen=%u tailroom=%u\n" + "mac=(%d,%d) mac_len=%u net=(%d,%d) trans=%d\n" + "shinfo(txflags=%u nr_frags=%u gso(size=%hu type=%u segs=%hu))\n" + "csum(0x%x start=%u offset=%u ip_summed=%u complete_sw=%u valid=%u level=%u)\n" + "hash(0x%x sw=%u l4=%u) proto=0x%04x pkttype=%u iif=%d\n" + "priority=0x%x mark=0x%x alloc_cpu=%u vlan_all=0x%x\n" + "encapsulation=%d inner(proto=0x%04x, mac=%u, net=%u, trans=%u)\n", + level, skb->len, headroom, skb_headlen(skb), tailroom, + has_mac ? skb->mac_header : -1, + has_mac ? skb_mac_header_len(skb) : -1, + skb->mac_len, + skb->network_header, + has_trans ? skb_network_header_len(skb) : -1, + has_trans ? skb->transport_header : -1, + sh->tx_flags, sh->nr_frags, + sh->gso_size, sh->gso_type, sh->gso_segs, + skb->csum, skb->csum_start, skb->csum_offset, skb->ip_summed, + skb->csum_complete_sw, skb->csum_valid, skb->csum_level, + skb->hash, skb->sw_hash, skb->l4_hash, + ntohs(skb->protocol), skb->pkt_type, skb->skb_iif, + skb->priority, skb->mark, skb->alloc_cpu, skb->vlan_all, + skb->encapsulation, skb->inner_protocol, skb->inner_mac_header, + skb->inner_network_header, skb->inner_transport_header); + + if (dev) + printk("%sdev name=%s feat=%pNF\n", + level, dev->name, &dev->features); + if (sk) + printk("%ssk family=%hu type=%u proto=%u\n", + level, sk->sk_family, sk->sk_type, sk->sk_protocol); + + if (full_pkt && headroom) + print_hex_dump(level, "skb headroom: ", DUMP_PREFIX_OFFSET, + 16, 1, skb->head, headroom, false); + + seg_len = min_t(int, skb_headlen(skb), len); + if (seg_len) + print_hex_dump(level, "skb linear: ", DUMP_PREFIX_OFFSET, + 16, 1, skb->data, seg_len, false); + len -= seg_len; + + if (full_pkt && tailroom) + print_hex_dump(level, "skb tailroom: ", DUMP_PREFIX_OFFSET, + 16, 1, skb_tail_pointer(skb), tailroom, false); + + for (i = 0; len && i < skb_shinfo(skb)->nr_frags; i++) { + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + u32 p_off, p_len, copied; + struct page *p; + u8 *vaddr; + + if (skb_frag_is_net_iov(frag)) { + printk("%sskb frag %d: not readable\n", level, i); + len -= skb_frag_size(frag); + if (!len) + break; + continue; + } + + skb_frag_foreach_page(frag, skb_frag_off(frag), + skb_frag_size(frag), p, p_off, p_len, + copied) { + seg_len = min_t(int, p_len, len); + vaddr = kmap_atomic(p); + print_hex_dump(level, "skb frag: ", + DUMP_PREFIX_OFFSET, + 16, 1, vaddr + p_off, seg_len, false); + kunmap_atomic(vaddr); + len -= seg_len; + if (!len) + break; + } + } + + if (full_pkt && skb_has_frag_list(skb)) { + printk("skb fraglist:\n"); + skb_walk_frags(skb, list_skb) + skb_dump(level, list_skb, true); + } } -EXPORT_SYMBOL(kfree_skb_list); +EXPORT_SYMBOL(skb_dump); /** * skb_tx_error - report an sk_buff xmit error @@ -680,10 +1403,14 @@ EXPORT_SYMBOL(kfree_skb_list); */ void skb_tx_error(struct sk_buff *skb) { - skb_zcopy_clear(skb, true); + if (skb) { + skb_zcopy_downgrade_managed(skb); + skb_zcopy_clear(skb, true); + } } EXPORT_SYMBOL(skb_tx_error); +#ifdef CONFIG_TRACEPOINTS /** * consume_skb - free an skbuff * @skb: buffer to free @@ -697,13 +1424,14 @@ void consume_skb(struct sk_buff *skb) if (!skb_unref(skb)) return; - trace_consume_skb(skb); + trace_consume_skb(skb, __builtin_return_address(0)); __kfree_skb(skb); } EXPORT_SYMBOL(consume_skb); +#endif /** - * consume_stateless_skb - free an skbuff, assuming it is stateless + * __consume_stateless_skb - free an skbuff, assuming it is stateless * @skb: buffer to free * * Alike consume_skb(), but this variant assumes that this is the last @@ -711,66 +1439,74 @@ EXPORT_SYMBOL(consume_skb); */ void __consume_stateless_skb(struct sk_buff *skb) { - trace_consume_skb(skb); - skb_release_data(skb); + trace_consume_skb(skb, __builtin_return_address(0)); + skb_release_data(skb, SKB_CONSUMED); kfree_skbmem(skb); } -void __kfree_skb_flush(void) +static void napi_skb_cache_put(struct sk_buff *skb) { struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); - /* flush skb_cache if containing objects */ - if (nc->skb_count) { - kmem_cache_free_bulk(skbuff_head_cache, nc->skb_count, - nc->skb_cache); - nc->skb_count = 0; - } -} - -static inline void _kfree_skb_defer(struct sk_buff *skb) -{ - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); - - /* drop skb->head and call any destructors for packet */ - skb_release_all(skb); + if (!kasan_mempool_poison_object(skb)) + return; - /* record skb to CPU local list */ + local_lock_nested_bh(&napi_alloc_cache.bh_lock); nc->skb_cache[nc->skb_count++] = skb; -#ifdef CONFIG_SLUB - /* SLUB writes into objects when freeing */ - prefetchw(skb); -#endif - - /* flush skb_cache if it is filled */ if (unlikely(nc->skb_count == NAPI_SKB_CACHE_SIZE)) { - kmem_cache_free_bulk(skbuff_head_cache, NAPI_SKB_CACHE_SIZE, - nc->skb_cache); - nc->skb_count = 0; + u32 i, remaining = NAPI_SKB_CACHE_SIZE - NAPI_SKB_CACHE_FREE; + + for (i = remaining; i < NAPI_SKB_CACHE_SIZE; i++) + kasan_mempool_unpoison_object(nc->skb_cache[i], + skbuff_cache_size); + + kmem_cache_free_bulk(net_hotdata.skbuff_cache, + NAPI_SKB_CACHE_FREE, + nc->skb_cache + remaining); + nc->skb_count = remaining; } + local_unlock_nested_bh(&napi_alloc_cache.bh_lock); } -void __kfree_skb_defer(struct sk_buff *skb) + +void __napi_kfree_skb(struct sk_buff *skb, enum skb_drop_reason reason) { - _kfree_skb_defer(skb); + skb_release_all(skb, reason); + napi_skb_cache_put(skb); } -void napi_consume_skb(struct sk_buff *skb, int budget) +void napi_skb_free_stolen_head(struct sk_buff *skb) { - if (unlikely(!skb)) - return; + if (unlikely(skb->slow_gro)) { + nf_reset_ct(skb); + skb_dst_drop(skb); + skb_ext_put(skb); + skb_orphan(skb); + skb->slow_gro = 0; + } + napi_skb_cache_put(skb); +} +void napi_consume_skb(struct sk_buff *skb, int budget) +{ /* Zero budget indicate non-NAPI context called us, like netpoll */ - if (unlikely(!budget)) { + if (unlikely(!budget || !skb)) { dev_consume_skb_any(skb); return; } + DEBUG_NET_WARN_ON_ONCE(!in_softirq()); + + if (skb->alloc_cpu != smp_processor_id() && !skb_shared(skb)) { + skb_release_head_state(skb); + return skb_attempt_defer_free(skb); + } + if (!skb_unref(skb)) return; /* if reaching here SKB is ready to free */ - trace_consume_skb(skb); + trace_consume_skb(skb, __builtin_return_address(0)); /* if SKB is a clone, don't handle this case */ if (skb->fclone != SKB_FCLONE_UNAVAILABLE) { @@ -778,16 +1514,15 @@ void napi_consume_skb(struct sk_buff *skb, int budget) return; } - _kfree_skb_defer(skb); + skb_release_all(skb, SKB_CONSUMED); + napi_skb_cache_put(skb); } EXPORT_SYMBOL(napi_consume_skb); -/* Make sure a field is enclosed inside headers_start/headers_end section */ +/* Make sure a field is contained by headers group */ #define CHECK_SKB_FIELD(field) \ - BUILD_BUG_ON(offsetof(struct sk_buff, field) < \ - offsetof(struct sk_buff, headers_start)); \ - BUILD_BUG_ON(offsetof(struct sk_buff, field) > \ - offsetof(struct sk_buff, headers_end)); \ + BUILD_BUG_ON(offsetof(struct sk_buff, field) != \ + offsetof(struct sk_buff, headers.field)); \ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) { @@ -799,14 +1534,12 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) __skb_ext_copy(new, old); __nf_copy(new, old, false); - /* Note : this field could be in headers_start/headers_end section + /* Note : this field could be in the headers group. * It is not yet because we do not want to have a 16 bit hole */ new->queue_mapping = old->queue_mapping; - memcpy(&new->headers_start, &old->headers_start, - offsetof(struct sk_buff, headers_end) - - offsetof(struct sk_buff, headers_start)); + memcpy(&new->headers, &old->headers, sizeof(new->headers)); CHECK_SKB_FIELD(protocol); CHECK_SKB_FIELD(csum); CHECK_SKB_FIELD(hash); @@ -828,6 +1561,7 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) #ifdef CONFIG_NET_RX_BUSY_POLL CHECK_SKB_FIELD(napi_id); #endif + CHECK_SKB_FIELD(alloc_cpu); #ifdef CONFIG_XPS CHECK_SKB_FIELD(sender_cpu); #endif @@ -857,6 +1591,7 @@ static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb) n->nohdr = 0; n->peeked = 0; C(pfmemalloc); + C(pp_recycle); n->destructor = NULL; C(tail); C(end); @@ -874,6 +1609,31 @@ static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb) } /** + * alloc_skb_for_msg() - allocate sk_buff to wrap frag list forming a msg + * @first: first sk_buff of the msg + */ +struct sk_buff *alloc_skb_for_msg(struct sk_buff *first) +{ + struct sk_buff *n; + + n = alloc_skb(0, GFP_ATOMIC); + if (!n) + return NULL; + + n->len = first->len; + n->data_len = first->len; + n->truesize = first->truesize; + + skb_shinfo(n)->frag_list = first; + + __copy_skb_header(n, first); + n->destructor = NULL; + + return n; +} +EXPORT_SYMBOL_GPL(alloc_skb_for_msg); + +/** * skb_morph - morph one skb into another * @dst: the skb to receive the contents * @src: the skb to supply the contents @@ -885,30 +1645,33 @@ static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb) */ struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src) { - skb_release_all(dst); + skb_release_all(dst, SKB_CONSUMED); return __skb_clone(dst, src); } EXPORT_SYMBOL_GPL(skb_morph); int mm_account_pinned_pages(struct mmpin *mmp, size_t size) { - unsigned long max_pg, num_pg, new_pg, old_pg; + unsigned long max_pg, num_pg, new_pg, old_pg, rlim; struct user_struct *user; if (capable(CAP_IPC_LOCK) || !size) return 0; + rlim = rlimit(RLIMIT_MEMLOCK); + if (rlim == RLIM_INFINITY) + return 0; + num_pg = (size >> PAGE_SHIFT) + 2; /* worst case */ - max_pg = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + max_pg = rlim >> PAGE_SHIFT; user = mmp->user ? : current_user(); + old_pg = atomic_long_read(&user->locked_vm); do { - old_pg = atomic_long_read(&user->locked_vm); new_pg = old_pg + num_pg; if (new_pg > max_pg) return -ENOBUFS; - } while (atomic_long_cmpxchg(&user->locked_vm, old_pg, new_pg) != - old_pg); + } while (!atomic_long_try_cmpxchg(&user->locked_vm, &old_pg, new_pg)); if (!mmp->user) { mmp->user = get_uid(user); @@ -930,9 +1693,10 @@ void mm_unaccount_pinned_pages(struct mmpin *mmp) } EXPORT_SYMBOL_GPL(mm_unaccount_pinned_pages); -struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size) +static struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size, + bool devmem) { - struct ubuf_info *uarg; + struct ubuf_info_msgzc *uarg; struct sk_buff *skb; WARN_ON_ONCE(!in_task()); @@ -945,35 +1709,40 @@ struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size) uarg = (void *)skb->cb; uarg->mmp.user = NULL; - if (mm_account_pinned_pages(&uarg->mmp, size)) { + if (likely(!devmem) && mm_account_pinned_pages(&uarg->mmp, size)) { kfree_skb(skb); return NULL; } - uarg->callback = sock_zerocopy_callback; + uarg->ubuf.ops = &msg_zerocopy_ubuf_ops; uarg->id = ((u32)atomic_inc_return(&sk->sk_zckey)) - 1; uarg->len = 1; uarg->bytelen = size; uarg->zerocopy = 1; - refcount_set(&uarg->refcnt, 1); + uarg->ubuf.flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN; + refcount_set(&uarg->ubuf.refcnt, 1); sock_hold(sk); - return uarg; + return &uarg->ubuf; } -EXPORT_SYMBOL_GPL(sock_zerocopy_alloc); -static inline struct sk_buff *skb_from_uarg(struct ubuf_info *uarg) +static inline struct sk_buff *skb_from_uarg(struct ubuf_info_msgzc *uarg) { return container_of((void *)uarg, struct sk_buff, cb); } -struct ubuf_info *sock_zerocopy_realloc(struct sock *sk, size_t size, - struct ubuf_info *uarg) +struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, + struct ubuf_info *uarg, bool devmem) { if (uarg) { + struct ubuf_info_msgzc *uarg_zc; const u32 byte_limit = 1 << 19; /* limit to a few TSO */ u32 bytelen, next; + /* there might be non MSG_ZEROCOPY users */ + if (uarg->ops != &msg_zerocopy_ubuf_ops) + return NULL; + /* realloc only when socket is locked (TCP, UDP cork), * so uarg->len and sk_zckey access is serialized */ @@ -982,8 +1751,9 @@ struct ubuf_info *sock_zerocopy_realloc(struct sock *sk, size_t size, return NULL; } - bytelen = uarg->bytelen + size; - if (uarg->len == USHRT_MAX - 1 || bytelen > byte_limit) { + uarg_zc = uarg_to_msgzc(uarg); + bytelen = uarg_zc->bytelen + size; + if (uarg_zc->len == USHRT_MAX - 1 || bytelen > byte_limit) { /* TCP can create new skb to attach new uarg */ if (sk->sk_type == SOCK_STREAM) goto new_alloc; @@ -991,21 +1761,26 @@ struct ubuf_info *sock_zerocopy_realloc(struct sock *sk, size_t size, } next = (u32)atomic_read(&sk->sk_zckey); - if ((u32)(uarg->id + uarg->len) == next) { - if (mm_account_pinned_pages(&uarg->mmp, size)) + if ((u32)(uarg_zc->id + uarg_zc->len) == next) { + if (likely(!devmem) && + mm_account_pinned_pages(&uarg_zc->mmp, size)) return NULL; - uarg->len++; - uarg->bytelen = bytelen; + uarg_zc->len++; + uarg_zc->bytelen = bytelen; atomic_set(&sk->sk_zckey, ++next); - sock_zerocopy_get(uarg); + + /* no extra ref when appending to datagram (MSG_MORE) */ + if (sk->sk_type == SOCK_STREAM) + net_zcopy_get(uarg); + return uarg; } } new_alloc: - return sock_zerocopy_alloc(sk, size); + return msg_zerocopy_alloc(sk, size, devmem); } -EXPORT_SYMBOL_GPL(sock_zerocopy_realloc); +EXPORT_SYMBOL_GPL(msg_zerocopy_realloc); static bool skb_zerocopy_notify_extend(struct sk_buff *skb, u32 lo, u16 len) { @@ -1027,13 +1802,14 @@ static bool skb_zerocopy_notify_extend(struct sk_buff *skb, u32 lo, u16 len) return true; } -void sock_zerocopy_callback(struct ubuf_info *uarg, bool success) +static void __msg_zerocopy_callback(struct ubuf_info_msgzc *uarg) { struct sk_buff *tail, *skb = skb_from_uarg(uarg); struct sock_exterr_skb *serr; struct sock *sk = skb->sk; struct sk_buff_head *q; unsigned long flags; + bool is_zerocopy; u32 lo, hi; u16 len; @@ -1048,6 +1824,7 @@ void sock_zerocopy_callback(struct ubuf_info *uarg, bool success) len = uarg->len; lo = uarg->id; hi = uarg->id + len - 1; + is_zerocopy = uarg->zerocopy; serr = SKB_EXT_ERR(skb); memset(serr, 0, sizeof(*serr)); @@ -1055,7 +1832,7 @@ void sock_zerocopy_callback(struct ubuf_info *uarg, bool success) serr->ee.ee_origin = SO_EE_ORIGIN_ZEROCOPY; serr->ee.ee_data = hi; serr->ee.ee_info = lo; - if (!success) + if (!is_zerocopy) serr->ee.ee_code |= SO_EE_CODE_ZEROCOPY_COPIED; q = &sk->sk_error_queue; @@ -1068,68 +1845,70 @@ void sock_zerocopy_callback(struct ubuf_info *uarg, bool success) } spin_unlock_irqrestore(&q->lock, flags); - sk->sk_error_report(sk); + sk_error_report(sk); release: consume_skb(skb); sock_put(sk); } -EXPORT_SYMBOL_GPL(sock_zerocopy_callback); -void sock_zerocopy_put(struct ubuf_info *uarg) +static void msg_zerocopy_complete(struct sk_buff *skb, struct ubuf_info *uarg, + bool success) { - if (uarg && refcount_dec_and_test(&uarg->refcnt)) { - if (uarg->callback) - uarg->callback(uarg, uarg->zerocopy); - else - consume_skb(skb_from_uarg(uarg)); - } + struct ubuf_info_msgzc *uarg_zc = uarg_to_msgzc(uarg); + + uarg_zc->zerocopy = uarg_zc->zerocopy & success; + + if (refcount_dec_and_test(&uarg->refcnt)) + __msg_zerocopy_callback(uarg_zc); } -EXPORT_SYMBOL_GPL(sock_zerocopy_put); -void sock_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref) +void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref) { - if (uarg) { - struct sock *sk = skb_from_uarg(uarg)->sk; + struct sock *sk = skb_from_uarg(uarg_to_msgzc(uarg))->sk; - atomic_dec(&sk->sk_zckey); - uarg->len--; + atomic_dec(&sk->sk_zckey); + uarg_to_msgzc(uarg)->len--; - if (have_uref) - sock_zerocopy_put(uarg); - } + if (have_uref) + msg_zerocopy_complete(NULL, uarg, true); } -EXPORT_SYMBOL_GPL(sock_zerocopy_put_abort); - -extern int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb, - struct iov_iter *from, size_t length); +EXPORT_SYMBOL_GPL(msg_zerocopy_put_abort); -int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len) -{ - return __zerocopy_sg_from_iter(skb->sk, skb, &msg->msg_iter, len); -} -EXPORT_SYMBOL_GPL(skb_zerocopy_iter_dgram); +const struct ubuf_info_ops msg_zerocopy_ubuf_ops = { + .complete = msg_zerocopy_complete, +}; +EXPORT_SYMBOL_GPL(msg_zerocopy_ubuf_ops); int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, struct msghdr *msg, int len, - struct ubuf_info *uarg) + struct ubuf_info *uarg, + struct net_devmem_dmabuf_binding *binding) { - struct ubuf_info *orig_uarg = skb_zcopy(skb); - struct iov_iter orig_iter = msg->msg_iter; int err, orig_len = skb->len; - /* An skb can only point to one uarg. This edge case happens when - * TCP appends to an skb, but zerocopy_realloc triggered a new alloc. - */ - if (orig_uarg && uarg != orig_uarg) - return -EEXIST; + if (uarg->ops->link_skb) { + err = uarg->ops->link_skb(skb, uarg); + if (err) + return err; + } else { + struct ubuf_info *orig_uarg = skb_zcopy(skb); + + /* An skb can only point to one uarg. This edge case happens + * when TCP appends to an skb, but zerocopy_realloc triggered + * a new alloc. + */ + if (orig_uarg && uarg != orig_uarg) + return -EEXIST; + } - err = __zerocopy_sg_from_iter(sk, skb, &msg->msg_iter, len); + err = __zerocopy_sg_from_iter(msg, sk, skb, &msg->msg_iter, len, + binding); if (err == -EFAULT || (err == -EMSGSIZE && skb->len == orig_len)) { struct sock *save_sk = skb->sk; /* Streams do not free skb on error. Reset to prev state. */ - msg->msg_iter = orig_iter; + iov_iter_revert(&msg->msg_iter, skb->len - orig_len); skb->sk = sk; ___pskb_trim(skb, orig_len); skb->sk = save_sk; @@ -1141,6 +1920,16 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, } EXPORT_SYMBOL_GPL(skb_zerocopy_iter_stream); +void __skb_zcopy_downgrade_managed(struct sk_buff *skb) +{ + int i; + + skb_shinfo(skb)->flags &= ~SKBFL_MANAGED_FRAG_REFS; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) + skb_frag_ref(skb, i); +} +EXPORT_SYMBOL_GPL(__skb_zcopy_downgrade_managed); + static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig, gfp_t gfp_mask) { @@ -1166,7 +1955,7 @@ static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig, * @skb: the skb to modify * @gfp_mask: allocation priority * - * This must be called on SKBTX_DEV_ZEROCOPY skb. + * This must be called on skb with SKBFL_ZEROCOPY_ENABLE. * It will copy all frags into kernel and drop the reference * to userspace pages. * @@ -1180,18 +1969,29 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) { int num_frags = skb_shinfo(skb)->nr_frags; struct page *page, *head = NULL; - int i, new_frags; + int i, order, psize, new_frags; u32 d_off; if (skb_shared(skb) || skb_unclone(skb, gfp_mask)) return -EINVAL; + if (!skb_frags_readable(skb)) + return -EFAULT; + if (!num_frags) goto release; - new_frags = (__skb_pagelen(skb) + PAGE_SIZE - 1) >> PAGE_SHIFT; + /* We might have to allocate high order pages, so compute what minimum + * page order is needed. + */ + order = 0; + while ((PAGE_SIZE << order) * MAX_SKB_FRAGS < __skb_pagelen(skb)) + order++; + psize = (PAGE_SIZE << order); + + new_frags = (__skb_pagelen(skb) + psize - 1) >> (PAGE_SHIFT + order); for (i = 0; i < new_frags; i++) { - page = alloc_page(gfp_mask); + page = alloc_pages(gfp_mask | __GFP_COMP, order); if (!page) { while (head) { struct page *next = (struct page *)page_private(head); @@ -1212,17 +2012,17 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) struct page *p; u8 *vaddr; - skb_frag_foreach_page(f, f->page_offset, skb_frag_size(f), + skb_frag_foreach_page(f, skb_frag_off(f), skb_frag_size(f), p, p_off, p_len, copied) { u32 copy, done = 0; vaddr = kmap_atomic(p); while (done < p_len) { - if (d_off == PAGE_SIZE) { + if (d_off == psize) { d_off = 0; page = (struct page *)page_private(page); } - copy = min_t(u32, PAGE_SIZE - d_off, p_len - done); + copy = min_t(u32, psize - d_off, p_len - done); memcpy(page_address(page) + d_off, vaddr + p_off + done, copy); done += copy; @@ -1238,10 +2038,11 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) /* skb frags point to kernel buffers */ for (i = 0; i < new_frags - 1; i++) { - __skb_fill_page_desc(skb, i, head, 0, PAGE_SIZE); + __skb_fill_netmem_desc(skb, i, page_to_netmem(head), 0, psize); head = (struct page *)page_private(head); } - __skb_fill_page_desc(skb, new_frags - 1, head, 0, d_off); + __skb_fill_netmem_desc(skb, new_frags - 1, page_to_netmem(head), 0, + d_off); skb_shinfo(skb)->nr_frags = new_frags; release: @@ -1278,11 +2079,12 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask) refcount_read(&fclones->fclone_ref) == 1) { n = &fclones->skb2; refcount_set(&fclones->fclone_ref, 2); + n->fclone = SKB_FCLONE_CLONE; } else { if (skb_pfmemalloc(skb)) gfp_mask |= __GFP_MEMALLOC; - n = kmem_cache_alloc(skbuff_head_cache, gfp_mask); + n = kmem_cache_alloc(net_hotdata.skbuff_cache, gfp_mask); if (!n) return NULL; @@ -1345,11 +2147,20 @@ static inline int skb_alloc_rx_flag(const struct sk_buff *skb) struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) { - int headerlen = skb_headroom(skb); - unsigned int size = skb_end_offset(skb) + skb->data_len; - struct sk_buff *n = __alloc_skb(size, gfp_mask, - skb_alloc_rx_flag(skb), NUMA_NO_NODE); + struct sk_buff *n; + unsigned int size; + int headerlen; + + if (!skb_frags_readable(skb)) + return NULL; + + if (WARN_ON_ONCE(skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)) + return NULL; + headerlen = skb_headroom(skb); + size = skb_end_offset(skb) + skb->data_len; + n = __alloc_skb(size, gfp_mask, + skb_alloc_rx_flag(skb), NUMA_NO_NODE); if (!n) return NULL; @@ -1444,29 +2255,34 @@ EXPORT_SYMBOL(__pskb_copy_fclone); * * All the pointers pointing into skb header may change and must be * reloaded after call to this function. + * + * Note: If you skb_push() the start of the buffer after reallocating the + * header, call skb_postpush_data_move() first to move the metadata out of + * the way before writing to &sk_buff->data. */ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask) { - int i, osize = skb_end_offset(skb); - int size = osize + nhead + ntail; + unsigned int osize = skb_end_offset(skb); + unsigned int size = osize + nhead + ntail; long off; u8 *data; + int i; BUG_ON(nhead < 0); BUG_ON(skb_shared(skb)); - size = SKB_DATA_ALIGN(size); + skb_zcopy_downgrade_managed(skb); if (skb_pfmemalloc(skb)) gfp_mask |= __GFP_MEMALLOC; - data = kmalloc_reserve(size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), - gfp_mask, NUMA_NO_NODE, NULL); + + data = kmalloc_reserve(&size, gfp_mask, NUMA_NO_NODE, NULL); if (!data) goto nodata; - size = SKB_WITH_OVERHEAD(ksize(data)); + size = SKB_WITH_OVERHEAD(size); /* Copy only real data... and, alas, header. This should be * optimized for the cases when header is void. @@ -1493,7 +2309,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, if (skb_has_frag_list(skb)) skb_clone_fraglist(skb); - skb_release_data(skb); + skb_release_data(skb, SKB_CONSUMED); } else { skb_free_head(skb); } @@ -1502,11 +2318,10 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, skb->head = data; skb->head_frag = 0; skb->data += off; + + skb_set_end_offset(skb, size); #ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->end = size; off = nhead; -#else - skb->end = skb->head + size; #endif skb->tail += off; skb_headers_offset_update(skb, nhead); @@ -1515,8 +2330,6 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, skb->nohdr = 0; atomic_set(&skb_shinfo(skb)->dataref, 1); - skb_metadata_clear(skb); - /* It is not generally safe to change skb->truesize. * For the moment, we really care of rx path, or * when skb is orphaned (not attached to a socket). @@ -1527,7 +2340,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, return 0; nofrags: - kfree(data); + skb_kfree_head(data, size); nodata: return -ENOMEM; } @@ -1554,6 +2367,104 @@ struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom) } EXPORT_SYMBOL(skb_realloc_headroom); +/* Note: We plan to rework this in linux-6.4 */ +int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri) +{ + unsigned int saved_end_offset, saved_truesize; + struct skb_shared_info *shinfo; + int res; + + saved_end_offset = skb_end_offset(skb); + saved_truesize = skb->truesize; + + res = pskb_expand_head(skb, 0, 0, pri); + if (res) + return res; + + skb->truesize = saved_truesize; + + if (likely(skb_end_offset(skb) == saved_end_offset)) + return 0; + + /* We can not change skb->end if the original or new value + * is SKB_SMALL_HEAD_HEADROOM, as it might break skb_kfree_head(). + */ + if (saved_end_offset == SKB_SMALL_HEAD_HEADROOM || + skb_end_offset(skb) == SKB_SMALL_HEAD_HEADROOM) { + /* We think this path should not be taken. + * Add a temporary trace to warn us just in case. + */ + pr_err_once("__skb_unclone_keeptruesize() skb_end_offset() %u -> %u\n", + saved_end_offset, skb_end_offset(skb)); + WARN_ON_ONCE(1); + return 0; + } + + shinfo = skb_shinfo(skb); + + /* We are about to change back skb->end, + * we need to move skb_shinfo() to its new location. + */ + memmove(skb->head + saved_end_offset, + shinfo, + offsetof(struct skb_shared_info, frags[shinfo->nr_frags])); + + skb_set_end_offset(skb, saved_end_offset); + + return 0; +} + +/** + * skb_expand_head - reallocate header of &sk_buff + * @skb: buffer to reallocate + * @headroom: needed headroom + * + * Unlike skb_realloc_headroom, this one does not allocate a new skb + * if possible; copies skb->sk to new skb as needed + * and frees original skb in case of failures. + * + * It expect increased headroom and generates warning otherwise. + */ + +struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom) +{ + int delta = headroom - skb_headroom(skb); + int osize = skb_end_offset(skb); + struct sock *sk = skb->sk; + + if (WARN_ONCE(delta <= 0, + "%s is expecting an increase in the headroom", __func__)) + return skb; + + delta = SKB_DATA_ALIGN(delta); + /* pskb_expand_head() might crash, if skb is shared. */ + if (skb_shared(skb) || !is_skb_wmem(skb)) { + struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); + + if (unlikely(!nskb)) + goto fail; + + if (sk) + skb_set_owner_w(nskb, sk); + consume_skb(skb); + skb = nskb; + } + if (pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) + goto fail; + + if (sk && is_skb_wmem(skb)) { + delta = skb_end_offset(skb) - osize; + refcount_add(delta, &sk->sk_wmem_alloc); + skb->truesize += delta; + } + return skb; + +fail: + kfree_skb(skb); + return NULL; +} +EXPORT_SYMBOL(skb_expand_head); + /** * skb_copy_expand - copy and expand sk_buff * @skb: buffer to copy @@ -1579,12 +2490,20 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, /* * Allocate the copy buffer */ - struct sk_buff *n = __alloc_skb(newheadroom + skb->len + newtailroom, - gfp_mask, skb_alloc_rx_flag(skb), - NUMA_NO_NODE); - int oldheadroom = skb_headroom(skb); int head_copy_len, head_copy_off; + struct sk_buff *n; + int oldheadroom; + + if (!skb_frags_readable(skb)) + return NULL; + + if (WARN_ON_ONCE(skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)) + return NULL; + oldheadroom = skb_headroom(skb); + n = __alloc_skb(newheadroom + skb->len + newtailroom, + gfp_mask, skb_alloc_rx_flag(skb), + NUMA_NO_NODE); if (!n) return NULL; @@ -1741,6 +2660,30 @@ void *skb_pull(struct sk_buff *skb, unsigned int len) EXPORT_SYMBOL(skb_pull); /** + * skb_pull_data - remove data from the start of a buffer returning its + * original position. + * @skb: buffer to use + * @len: amount of data to remove + * + * This function removes data from the start of a buffer, returning + * the memory to the headroom. A pointer to the original data in the buffer + * is returned after checking if there is enough data to pull. Once the + * data has been pulled future pushes will overwrite the old data. + */ +void *skb_pull_data(struct sk_buff *skb, size_t len) +{ + void *data = skb->data; + + if (skb->len < len) + return NULL; + + skb_pull(skb, len); + + return data; +} +EXPORT_SYMBOL(skb_pull_data); + +/** * skb_trim - remove end from a buffer * @skb: buffer to alter * @len: new length @@ -1854,6 +2797,12 @@ int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len) skb->csum = csum_block_sub(skb->csum, skb_checksum(skb, len, delta, 0), len); + } else if (skb->ip_summed == CHECKSUM_PARTIAL) { + int hdlen = (len > skb_headlen(skb)) ? skb_headlen(skb) : len; + int offset = skb_checksum_start_offset(skb) + skb->csum_offset; + + if (offset + sizeof(__sum16) > hdlen) + return -EINVAL; } return __pskb_trim(skb, len); } @@ -1892,6 +2841,9 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta) */ int i, k, eat = (skb->tail + delta) - skb->end; + if (!skb_frags_readable(skb)) + return NULL; + if (eat > 0 || skb_cloned(skb)) { if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0, GFP_ATOMIC)) @@ -1937,6 +2889,9 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta) insp = list; } else { /* Eaten partially. */ + if (skb_is_gso(skb) && !list->head_frag && + skb_headlen(list)) + skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; if (skb_shared(list)) { /* Sucks! We need to fork list. :-( */ @@ -1961,7 +2916,7 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta) /* Free pulled out fragments. */ while ((list = skb_shinfo(skb)->frag_list) != insp) { skb_shinfo(skb)->frag_list = list->next; - kfree_skb(list); + consume_skb(list); } /* And insert new clone at head. */ if (clone) { @@ -1981,10 +2936,12 @@ pull_pages: skb_frag_unref(skb, i); eat -= size; } else { - skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i]; + skb_frag_t *frag = &skb_shinfo(skb)->frags[k]; + + *frag = skb_shinfo(skb)->frags[i]; if (eat) { - skb_shinfo(skb)->frags[k].page_offset += eat; - skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat); + skb_frag_off_add(frag, eat); + skb_frag_size_sub(frag, eat); if (!i) goto end; eat = 0; @@ -2040,6 +2997,9 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len) to += copy; } + if (!skb_frags_readable(skb)) + goto fault; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { int end; skb_frag_t *f = &skb_shinfo(skb)->frags[i]; @@ -2056,7 +3016,7 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len) copy = len; skb_frag_foreach_page(f, - f->page_offset + offset - start, + skb_frag_off(f) + offset - start, copy, p, p_off, p_len, copied) { vaddr = kmap_atomic(p); memcpy(to + copied, vaddr + p_off, p_len); @@ -2139,10 +3099,8 @@ static bool spd_can_coalesce(const struct splice_pipe_desc *spd, /* * Fill page/offset/length into spd, if it can hold more pages. */ -static bool spd_fill_page(struct splice_pipe_desc *spd, - struct pipe_inode_info *pipe, struct page *page, - unsigned int *len, unsigned int offset, - bool linear, +static bool spd_fill_page(struct splice_pipe_desc *spd, struct page *page, + unsigned int *len, unsigned int offset, bool linear, struct sock *sk) { if (unlikely(spd->nr_pages == MAX_SKB_FRAGS)) @@ -2170,8 +3128,7 @@ static bool __splice_segment(struct page *page, unsigned int poff, unsigned int plen, unsigned int *off, unsigned int *len, struct splice_pipe_desc *spd, bool linear, - struct sock *sk, - struct pipe_inode_info *pipe) + struct sock *sk) { if (!*len) return true; @@ -2190,13 +3147,14 @@ static bool __splice_segment(struct page *page, unsigned int poff, do { unsigned int flen = min(*len, plen); - if (spd_fill_page(spd, pipe, page, &flen, poff, - linear, sk)) + if (spd_fill_page(spd, page, &flen, poff, linear, sk)) return true; poff += flen; plen -= flen; *len -= flen; - } while (*len && plen); + if (!*len) + return true; + } while (plen); return false; } @@ -2209,8 +3167,8 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, unsigned int *offset, unsigned int *len, struct splice_pipe_desc *spd, struct sock *sk) { - int seg; struct sk_buff *iter; + int seg; /* map the linear part : * If skb->head_frag is set, this 'linear' part is backed by a @@ -2222,18 +3180,24 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, skb_headlen(skb), offset, len, spd, skb_head_is_locked(skb), - sk, pipe)) + sk)) return true; /* * then map the fragments */ + if (!skb_frags_readable(skb)) + return false; + for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) { const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; + if (WARN_ON_ONCE(!skb_frag_page(f))) + return false; + if (__splice_segment(skb_frag_page(f), - f->page_offset, skb_frag_size(f), - offset, len, spd, false, sk, pipe)) + skb_frag_off(f), skb_frag_size(f), + offset, len, spd, false, sk)) return true; } @@ -2281,10 +3245,34 @@ int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset, } EXPORT_SYMBOL_GPL(skb_splice_bits); -/* Send skb data on a socket. Socket must be locked. */ -int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset, - int len) +static int sendmsg_locked(struct sock *sk, struct msghdr *msg) +{ + struct socket *sock = sk->sk_socket; + size_t size = msg_data_left(msg); + + if (!sock) + return -EINVAL; + + if (!sock->ops->sendmsg_locked) + return sock_no_sendmsg_locked(sk, msg, size); + + return sock->ops->sendmsg_locked(sk, msg, size); +} + +static int sendmsg_unlocked(struct sock *sk, struct msghdr *msg) { + struct socket *sock = sk->sk_socket; + + if (!sock) + return -EINVAL; + return sock_sendmsg(sock, msg); +} + +typedef int (*sendmsg_func)(struct sock *sk, struct msghdr *msg); +static int __skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, + int len, sendmsg_func sendmsg, int flags) +{ + int more_hint = sk_is_tcp(sk) ? MSG_MORE : 0; unsigned int orig_len = len; struct sk_buff *head = skb; unsigned short fragidx; @@ -2301,8 +3289,13 @@ do_frag_list: kv.iov_base = skb->data + offset; kv.iov_len = slen; memset(&msg, 0, sizeof(msg)); + msg.msg_flags = MSG_DONTWAIT | flags; + if (slen < len) + msg.msg_flags |= more_hint; - ret = kernel_sendmsg_locked(sk, &msg, &kv, 1, slen); + iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &kv, 1, slen); + ret = INDIRECT_CALL_2(sendmsg, sendmsg_locked, + sendmsg_unlocked, sk, &msg); if (ret <= 0) goto error; @@ -2321,21 +3314,33 @@ do_frag_list: for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; fragidx++) { skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx]; - if (offset < frag->size) + if (offset < skb_frag_size(frag)) break; - offset -= frag->size; + offset -= skb_frag_size(frag); } for (; len && fragidx < skb_shinfo(skb)->nr_frags; fragidx++) { skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx]; - slen = min_t(size_t, len, frag->size - offset); + slen = min_t(size_t, len, skb_frag_size(frag) - offset); while (slen) { - ret = kernel_sendpage_locked(sk, frag->page.p, - frag->page_offset + offset, - slen, MSG_DONTWAIT); + struct bio_vec bvec; + struct msghdr msg = { + .msg_flags = MSG_SPLICE_PAGES | MSG_DONTWAIT | + flags, + }; + + if (slen < len) + msg.msg_flags |= more_hint; + bvec_set_page(&bvec, skb_frag_page(frag), slen, + skb_frag_off(frag) + offset); + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, + slen); + + ret = INDIRECT_CALL_2(sendmsg, sendmsg_locked, + sendmsg_unlocked, sk, &msg); if (ret <= 0) goto error; @@ -2367,8 +3372,28 @@ out: error: return orig_len == len ? ret : orig_len - len; } + +/* Send skb data on a socket. Socket must be locked. */ +int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset, + int len) +{ + return __skb_send_sock(sk, skb, offset, len, sendmsg_locked, 0); +} EXPORT_SYMBOL_GPL(skb_send_sock_locked); +int skb_send_sock_locked_with_flags(struct sock *sk, struct sk_buff *skb, + int offset, int len, int flags) +{ + return __skb_send_sock(sk, skb, offset, len, sendmsg_locked, flags); +} +EXPORT_SYMBOL_GPL(skb_send_sock_locked_with_flags); + +/* Send skb data on a socket. Socket must be unlocked. */ +int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len) +{ + return __skb_send_sock(sk, skb, offset, len, sendmsg_unlocked, 0); +} + /** * skb_store_bits - store bits from kernel buffer to skb * @skb: destination buffer @@ -2400,6 +3425,9 @@ int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len) from += copy; } + if (!skb_frags_readable(skb)) + goto fault; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; int end; @@ -2416,7 +3444,7 @@ int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len) copy = len; skb_frag_foreach_page(frag, - frag->page_offset + offset - start, + skb_frag_off(frag) + offset - start, copy, p, p_off, p_len, copied) { vaddr = kmap_atomic(p); memcpy(vaddr + p_off, from + copied, p_len); @@ -2459,8 +3487,7 @@ fault: EXPORT_SYMBOL(skb_store_bits); /* Checksum skb data. */ -__wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, - __wsum csum, const struct skb_checksum_ops *ops) +__wsum skb_checksum(const struct sk_buff *skb, int offset, int len, __wsum csum) { int start = skb_headlen(skb); int i, copy = start - offset; @@ -2471,13 +3498,16 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, if (copy > 0) { if (copy > len) copy = len; - csum = ops->update(skb->data + offset, copy, csum); + csum = csum_partial(skb->data + offset, copy, csum); if ((len -= copy) == 0) return csum; offset += copy; pos = copy; } + if (WARN_ON_ONCE(!skb_frags_readable(skb))) + return 0; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { int end; skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; @@ -2495,12 +3525,12 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, copy = len; skb_frag_foreach_page(frag, - frag->page_offset + offset - start, + skb_frag_off(frag) + offset - start, copy, p, p_off, p_len, copied) { vaddr = kmap_atomic(p); - csum2 = ops->update(vaddr + p_off, p_len, 0); + csum2 = csum_partial(vaddr + p_off, p_len, 0); kunmap_atomic(vaddr); - csum = ops->combine(csum, csum2, pos, p_len); + csum = csum_block_add(csum, csum2, pos); pos += p_len; } @@ -2521,9 +3551,9 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, __wsum csum2; if (copy > len) copy = len; - csum2 = __skb_checksum(frag_iter, offset - start, - copy, 0, ops); - csum = ops->combine(csum, csum2, pos, copy); + csum2 = skb_checksum(frag_iter, offset - start, copy, + 0); + csum = csum_block_add(csum, csum2, pos); if ((len -= copy) == 0) return csum; offset += copy; @@ -2535,36 +3565,25 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, return csum; } -EXPORT_SYMBOL(__skb_checksum); - -__wsum skb_checksum(const struct sk_buff *skb, int offset, - int len, __wsum csum) -{ - const struct skb_checksum_ops ops = { - .update = csum_partial_ext, - .combine = csum_block_add_ext, - }; - - return __skb_checksum(skb, offset, len, csum, &ops); -} EXPORT_SYMBOL(skb_checksum); /* Both of above in one bottle. */ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, - u8 *to, int len, __wsum csum) + u8 *to, int len) { int start = skb_headlen(skb); int i, copy = start - offset; struct sk_buff *frag_iter; int pos = 0; + __wsum csum = 0; /* Copy header. */ if (copy > 0) { if (copy > len) copy = len; csum = csum_partial_copy_nocheck(skb->data + offset, to, - copy, csum); + copy); if ((len -= copy) == 0) return csum; offset += copy; @@ -2572,6 +3591,9 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, pos = copy; } + if (!skb_frags_readable(skb)) + return 0; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { int end; @@ -2589,12 +3611,12 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, copy = len; skb_frag_foreach_page(frag, - frag->page_offset + offset - start, + skb_frag_off(frag) + offset - start, copy, p, p_off, p_len, copied) { vaddr = kmap_atomic(p); csum2 = csum_partial_copy_nocheck(vaddr + p_off, to + copied, - p_len, 0); + p_len); kunmap_atomic(vaddr); csum = csum_block_add(csum, csum2, pos); pos += p_len; @@ -2620,7 +3642,7 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, copy = len; csum2 = skb_copy_and_csum_bits(frag_iter, offset - start, - to, copy, 0); + to, copy); csum = csum_block_add(csum, csum2, pos); if ((len -= copy) == 0) return csum; @@ -2635,6 +3657,78 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, } EXPORT_SYMBOL(skb_copy_and_csum_bits); +#ifdef CONFIG_NET_CRC32C +u32 skb_crc32c(const struct sk_buff *skb, int offset, int len, u32 crc) +{ + int start = skb_headlen(skb); + int i, copy = start - offset; + struct sk_buff *frag_iter; + + if (copy > 0) { + copy = min(copy, len); + crc = crc32c(crc, skb->data + offset, copy); + len -= copy; + if (len == 0) + return crc; + offset += copy; + } + + if (WARN_ON_ONCE(!skb_frags_readable(skb))) + return 0; + + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { + int end; + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + + WARN_ON(start > offset + len); + + end = start + skb_frag_size(frag); + copy = end - offset; + if (copy > 0) { + u32 p_off, p_len, copied; + struct page *p; + u8 *vaddr; + + copy = min(copy, len); + skb_frag_foreach_page(frag, + skb_frag_off(frag) + offset - start, + copy, p, p_off, p_len, copied) { + vaddr = kmap_atomic(p); + crc = crc32c(crc, vaddr + p_off, p_len); + kunmap_atomic(vaddr); + } + len -= copy; + if (len == 0) + return crc; + offset += copy; + } + start = end; + } + + skb_walk_frags(skb, frag_iter) { + int end; + + WARN_ON(start > offset + len); + + end = start + frag_iter->len; + copy = end - offset; + if (copy > 0) { + copy = min(copy, len); + crc = skb_crc32c(frag_iter, offset - start, copy, crc); + len -= copy; + if (len == 0) + return crc; + offset += copy; + } + start = end; + } + BUG_ON(len); + + return crc; +} +EXPORT_SYMBOL(skb_crc32c); +#endif /* CONFIG_NET_CRC32C */ + __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len) { __sum16 sum; @@ -2694,32 +3788,6 @@ __sum16 __skb_checksum_complete(struct sk_buff *skb) } EXPORT_SYMBOL(__skb_checksum_complete); -static __wsum warn_crc32c_csum_update(const void *buff, int len, __wsum sum) -{ - net_warn_ratelimited( - "%s: attempt to compute crc32c without libcrc32c.ko\n", - __func__); - return 0; -} - -static __wsum warn_crc32c_csum_combine(__wsum csum, __wsum csum2, - int offset, int len) -{ - net_warn_ratelimited( - "%s: attempt to compute crc32c without libcrc32c.ko\n", - __func__); - return 0; -} - -static const struct skb_checksum_ops default_crc32c_ops = { - .update = warn_crc32c_csum_update, - .combine = warn_crc32c_csum_combine, -}; - -const struct skb_checksum_ops *crc32c_csum_stub __read_mostly = - &default_crc32c_ops; -EXPORT_SYMBOL(crc32c_csum_stub); - /** * skb_zerocopy_headlen - Calculate headroom needed for skb_zerocopy() * @from: source buffer @@ -2734,8 +3802,11 @@ skb_zerocopy_headlen(const struct sk_buff *from) if (!from->head_frag || skb_headlen(from) < L1_CACHE_BYTES || - skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS) + skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS) { hlen = skb_headlen(from); + if (!hlen) + hlen = from->len; + } if (skb_has_frag_list(from)) hlen = from->len; @@ -2787,16 +3858,15 @@ skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen) if (plen) { page = virt_to_head_page(from->head); offset = from->data - (unsigned char *)page_address(page); - __skb_fill_page_desc(to, 0, page, offset, plen); + __skb_fill_netmem_desc(to, 0, page_to_netmem(page), + offset, plen); get_page(page); j = 1; len -= plen; } } - to->truesize += len + plen; - to->len += len + plen; - to->data_len += len + plen; + skb_len_add(to, len + plen); if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) { skb_tx_error(from); @@ -2805,11 +3875,15 @@ skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen) skb_zerocopy_clone(to, from, GFP_ATOMIC); for (i = 0; i < skb_shinfo(from)->nr_frags; i++) { + int size; + if (!len) break; skb_shinfo(to)->frags[j] = skb_shinfo(from)->frags[i]; - skb_shinfo(to)->frags[j].size = min_t(int, skb_shinfo(to)->frags[j].size, len); - len -= skb_shinfo(to)->frags[j].size; + size = min_t(int, skb_frag_size(&skb_shinfo(to)->frags[j]), + len); + skb_frag_size_set(&skb_shinfo(to)->frags[j], size); + len -= size; skb_frag_ref(to, j); j++; } @@ -2836,7 +3910,7 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to) csum = 0; if (csstart != skb->len) csum = skb_copy_and_csum_bits(skb, csstart, to + csstart, - skb->len - csstart, 0); + skb->len - csstart); if (skb->ip_summed == CHECKSUM_PARTIAL) { long csstuff = csstart + skb->csum_offset; @@ -2888,20 +3962,32 @@ struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list) EXPORT_SYMBOL(skb_dequeue_tail); /** - * skb_queue_purge - empty a list + * skb_queue_purge_reason - empty a list * @list: list to empty + * @reason: drop reason * * Delete all buffers on an &sk_buff list. Each buffer is removed from * the list and one reference dropped. This function takes the list * lock and is atomic with respect to other list locking functions. */ -void skb_queue_purge(struct sk_buff_head *list) +void skb_queue_purge_reason(struct sk_buff_head *list, + enum skb_drop_reason reason) { - struct sk_buff *skb; - while ((skb = skb_dequeue(list)) != NULL) - kfree_skb(skb); + struct sk_buff_head tmp; + unsigned long flags; + + if (skb_queue_empty_lockless(list)) + return; + + __skb_queue_head_init(&tmp); + + spin_lock_irqsave(&list->lock, flags); + skb_queue_splice_init(list, &tmp); + spin_unlock_irqrestore(&list->lock, flags); + + __skb_queue_purge_reason(&tmp, reason); } -EXPORT_SYMBOL(skb_queue_purge); +EXPORT_SYMBOL(skb_queue_purge_reason); /** * skb_rbtree_purge - empty a skb rbtree @@ -2929,6 +4015,27 @@ unsigned int skb_rbtree_purge(struct rb_root *root) return sum; } +void skb_errqueue_purge(struct sk_buff_head *list) +{ + struct sk_buff *skb, *next; + struct sk_buff_head kill; + unsigned long flags; + + __skb_queue_head_init(&kill); + + spin_lock_irqsave(&list->lock, flags); + skb_queue_walk_safe(list, skb, next) { + if (SKB_EXT_ERR(skb)->ee.ee_origin == SO_EE_ORIGIN_ZEROCOPY || + SKB_EXT_ERR(skb)->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) + continue; + __skb_unlink(skb, list); + __skb_queue_tail(&kill, skb); + } + spin_unlock_irqrestore(&list->lock, flags); + __skb_queue_purge(&kill); +} +EXPORT_SYMBOL(skb_errqueue_purge); + /** * skb_queue_head - queue a buffer at the list head * @list: list to use @@ -3024,6 +4131,7 @@ static inline void skb_split_inside_header(struct sk_buff *skb, skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i]; skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags; + skb1->unreadable = skb->unreadable; skb_shinfo(skb)->nr_frags = 0; skb1->data_len = skb->data_len; skb1->len += skb1->data_len; @@ -3060,7 +4168,7 @@ static inline void skb_split_no_header(struct sk_buff *skb, * 2. Split is accurately. We make this. */ skb_frag_ref(skb, i); - skb_shinfo(skb1)->frags[0].page_offset += len - pos; + skb_frag_off_add(&skb_shinfo(skb1)->frags[0], len - pos); skb_frag_size_sub(&skb_shinfo(skb1)->frags[0], len - pos); skb_frag_size_set(&skb_shinfo(skb)->frags[i], len - pos); skb_shinfo(skb)->nr_frags++; @@ -3071,6 +4179,8 @@ static inline void skb_split_no_header(struct sk_buff *skb, pos += size; } skb_shinfo(skb1)->nr_frags = k; + + skb1->unreadable = skb->unreadable; } /** @@ -3082,9 +4192,11 @@ static inline void skb_split_no_header(struct sk_buff *skb, void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len) { int pos = skb_headlen(skb); + const int zc_flags = SKBFL_SHARED_FRAG | SKBFL_PURE_ZEROCOPY; - skb_shinfo(skb1)->tx_flags |= skb_shinfo(skb)->tx_flags & - SKBTX_SHARED_FRAG; + skb_zcopy_downgrade_managed(skb); + + skb_shinfo(skb1)->flags |= skb_shinfo(skb)->flags & zc_flags; skb_zerocopy_clone(skb1, skb, 0); if (len < pos) /* Split line is inside header. */ skb_split_inside_header(skb, skb1, len, pos); @@ -3099,7 +4211,7 @@ EXPORT_SYMBOL(skb_split); */ static int skb_prepare_for_shift(struct sk_buff *skb) { - return skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC); + return skb_unclone_keeptruesize(skb, GFP_ATOMIC); } /** @@ -3123,7 +4235,7 @@ static int skb_prepare_for_shift(struct sk_buff *skb) int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) { int from, to, merge, todo; - struct skb_frag_struct *fragfrom, *fragto; + skb_frag_t *fragfrom, *fragto; BUG_ON(shiftlen > skb->len); @@ -3132,6 +4244,9 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) if (skb_zcopy(tgt) || skb_zcopy(skb)) return 0; + DEBUG_NET_WARN_ON_ONCE(tgt->pp_recycle != skb->pp_recycle); + DEBUG_NET_WARN_ON_ONCE(skb_cmp_decrypted(tgt, skb)); + todo = shiftlen; from = 0; to = skb_shinfo(tgt)->nr_frags; @@ -3140,9 +4255,8 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) /* Actual merge is delayed until the point when we know we can * commit all, so that we don't have to undo partial changes */ - if (!to || - !skb_can_coalesce(tgt, to, skb_frag_page(fragfrom), - fragfrom->page_offset)) { + if (!skb_can_coalesce(tgt, to, skb_frag_page(fragfrom), + skb_frag_off(fragfrom))) { merge = -1; } else { merge = to - 1; @@ -3159,7 +4273,7 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) skb_frag_size_add(fragto, shiftlen); skb_frag_size_sub(fragfrom, shiftlen); - fragfrom->page_offset += shiftlen; + skb_frag_off_add(fragfrom, shiftlen); goto onlymerged; } @@ -3190,11 +4304,11 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) } else { __skb_frag_ref(fragfrom); - fragto->page = fragfrom->page; - fragto->page_offset = fragfrom->page_offset; + skb_frag_page_copy(fragto, fragfrom); + skb_frag_off_copy(fragto, fragfrom); skb_frag_size_set(fragto, todo); - fragfrom->page_offset += todo; + skb_frag_off_add(fragfrom, todo); skb_frag_size_sub(fragfrom, todo); todo = 0; @@ -3211,7 +4325,7 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) fragto = &skb_shinfo(tgt)->frags[merge]; skb_frag_size_add(fragto, skb_frag_size(fragfrom)); - __skb_frag_unref(fragfrom); + __skb_frag_unref(fragfrom, skb->pp_recycle); } /* Reposition in the original skb */ @@ -3229,13 +4343,8 @@ onlymerged: tgt->ip_summed = CHECKSUM_PARTIAL; skb->ip_summed = CHECKSUM_PARTIAL; - /* Yak, is it really working this way? Some helper please? */ - skb->len -= shiftlen; - skb->data_len -= shiftlen; - skb->truesize -= shiftlen; - tgt->len += shiftlen; - tgt->data_len += shiftlen; - tgt->truesize += shiftlen; + skb_len_add(skb, -shiftlen); + skb_len_add(tgt, shiftlen); return shiftlen; } @@ -3258,6 +4367,7 @@ void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, st->root_skb = st->cur_skb = skb; st->frag_idx = st->stepped_offset = 0; st->frag_data = NULL; + st->frag_off = 0; } EXPORT_SYMBOL(skb_prepare_seq_read); @@ -3308,18 +4418,34 @@ next_skb: return block_limit - abs_offset; } + if (!skb_frags_readable(st->cur_skb)) + return 0; + if (st->frag_idx == 0 && !st->frag_data) st->stepped_offset += skb_headlen(st->cur_skb); while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) { + unsigned int pg_idx, pg_off, pg_sz; + frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx]; - block_limit = skb_frag_size(frag) + st->stepped_offset; + pg_idx = 0; + pg_off = skb_frag_off(frag); + pg_sz = skb_frag_size(frag); + + if (skb_frag_must_loop(skb_frag_page(frag))) { + pg_idx = (pg_off + st->frag_off) >> PAGE_SHIFT; + pg_off = offset_in_page(pg_off + st->frag_off); + pg_sz = min_t(unsigned int, pg_sz - st->frag_off, + PAGE_SIZE - pg_off); + } + + block_limit = pg_sz + st->stepped_offset; if (abs_offset < block_limit) { if (!st->frag_data) - st->frag_data = kmap_atomic(skb_frag_page(frag)); + st->frag_data = kmap_atomic(skb_frag_page(frag) + pg_idx); - *data = (u8 *) st->frag_data + frag->page_offset + + *data = (u8 *)st->frag_data + pg_off + (abs_offset - st->stepped_offset); return block_limit - abs_offset; @@ -3330,8 +4456,12 @@ next_skb: st->frag_data = NULL; } - st->frag_idx++; - st->stepped_offset += skb_frag_size(frag); + st->stepped_offset += pg_sz; + st->frag_off += pg_sz; + if (st->frag_off == skb_frag_size(frag)) { + st->frag_off = 0; + st->frag_idx++; + } } if (st->frag_data) { @@ -3367,6 +4497,41 @@ void skb_abort_seq_read(struct skb_seq_state *st) } EXPORT_SYMBOL(skb_abort_seq_read); +/** + * skb_copy_seq_read() - copy from a skb_seq_state to a buffer + * @st: source skb_seq_state + * @offset: offset in source + * @to: destination buffer + * @len: number of bytes to copy + * + * Copy @len bytes from @offset bytes into the source @st to the destination + * buffer @to. `offset` should increase (or be unchanged) with each subsequent + * call to this function. If offset needs to decrease from the previous use `st` + * should be reset first. + * + * Return: 0 on success or -EINVAL if the copy ended early + */ +int skb_copy_seq_read(struct skb_seq_state *st, int offset, void *to, int len) +{ + const u8 *data; + u32 sqlen; + + for (;;) { + sqlen = skb_seq_read(offset, &data, st); + if (sqlen == 0) + return -EINVAL; + if (sqlen >= len) { + memcpy(to, data, len); + return 0; + } + memcpy(to, data, sqlen); + to += sqlen; + offset += sqlen; + len -= sqlen; + } +} +EXPORT_SYMBOL(skb_copy_seq_read); + #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb)) static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text, @@ -3396,29 +4561,33 @@ static void skb_ts_finish(struct ts_config *conf, struct ts_state *state) unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, unsigned int to, struct ts_config *config) { + unsigned int patlen = config->ops->get_pattern_len(config); struct ts_state state; unsigned int ret; + BUILD_BUG_ON(sizeof(struct skb_seq_state) > sizeof(state.cb)); + config->get_next_block = skb_ts_get_next_block; config->finish = skb_ts_finish; skb_prepare_seq_read(skb, from, to, TS_SKB_CB(&state)); ret = textsearch_find(config, &state); - return (ret <= to - from ? ret : UINT_MAX); + return (ret + patlen <= to - from ? ret : UINT_MAX); } EXPORT_SYMBOL(skb_find_text); int skb_append_pagefrags(struct sk_buff *skb, struct page *page, - int offset, size_t size) + int offset, size_t size, size_t max_frags) { int i = skb_shinfo(skb)->nr_frags; if (skb_can_coalesce(skb, i, page, offset)) { skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size); - } else if (i < MAX_SKB_FRAGS) { + } else if (i < max_frags) { + skb_zcopy_downgrade_managed(skb); get_page(page); - skb_fill_page_desc(skb, i, page, offset, size); + skb_fill_page_desc_noacc(skb, i, page, offset, size); } else { return -EMSGSIZE; } @@ -3455,13 +4624,104 @@ static inline skb_frag_t skb_head_frag_to_page_desc(struct sk_buff *frag_skb) struct page *page; page = virt_to_head_page(frag_skb->head); - head_frag.page.p = page; - head_frag.page_offset = frag_skb->data - - (unsigned char *)page_address(page); - head_frag.size = skb_headlen(frag_skb); + skb_frag_fill_page_desc(&head_frag, page, frag_skb->data - + (unsigned char *)page_address(page), + skb_headlen(frag_skb)); return head_frag; } +struct sk_buff *skb_segment_list(struct sk_buff *skb, + netdev_features_t features, + unsigned int offset) +{ + struct sk_buff *list_skb = skb_shinfo(skb)->frag_list; + unsigned int tnl_hlen = skb_tnl_header_len(skb); + unsigned int delta_truesize = 0; + unsigned int delta_len = 0; + struct sk_buff *tail = NULL; + struct sk_buff *nskb, *tmp; + int len_diff, err; + + skb_push(skb, -skb_network_offset(skb) + offset); + + /* Ensure the head is writeable before touching the shared info */ + err = skb_unclone(skb, GFP_ATOMIC); + if (err) + goto err_linearize; + + skb_shinfo(skb)->frag_list = NULL; + + while (list_skb) { + nskb = list_skb; + list_skb = list_skb->next; + + err = 0; + delta_truesize += nskb->truesize; + if (skb_shared(nskb)) { + tmp = skb_clone(nskb, GFP_ATOMIC); + if (tmp) { + consume_skb(nskb); + nskb = tmp; + err = skb_unclone(nskb, GFP_ATOMIC); + } else { + err = -ENOMEM; + } + } + + if (!tail) + skb->next = nskb; + else + tail->next = nskb; + + if (unlikely(err)) { + nskb->next = list_skb; + goto err_linearize; + } + + tail = nskb; + + delta_len += nskb->len; + + skb_push(nskb, -skb_network_offset(nskb) + offset); + + skb_release_head_state(nskb); + len_diff = skb_network_header_len(nskb) - skb_network_header_len(skb); + __copy_skb_header(nskb, skb); + + skb_headers_offset_update(nskb, skb_headroom(nskb) - skb_headroom(skb)); + nskb->transport_header += len_diff; + skb_copy_from_linear_data_offset(skb, -tnl_hlen, + nskb->data - tnl_hlen, + offset + tnl_hlen); + + if (skb_needs_linearize(nskb, features) && + __skb_linearize(nskb)) + goto err_linearize; + } + + skb->truesize = skb->truesize - delta_truesize; + skb->data_len = skb->data_len - delta_len; + skb->len = skb->len - delta_len; + + skb_gso_reset(skb); + + skb->prev = tail; + + if (skb_needs_linearize(skb, features) && + __skb_linearize(skb)) + goto err_linearize; + + skb_get(skb); + + return skb; + +err_linearize: + kfree_skb_list(skb->next); + skb->next = NULL; + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(skb_segment_list); + /** * skb_segment - Perform protocol segmentation on skb. * @head_skb: buffer to segment @@ -3477,25 +4737,44 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, struct sk_buff *segs = NULL; struct sk_buff *tail = NULL; struct sk_buff *list_skb = skb_shinfo(head_skb)->frag_list; - skb_frag_t *frag = skb_shinfo(head_skb)->frags; unsigned int mss = skb_shinfo(head_skb)->gso_size; unsigned int doffset = head_skb->data - skb_mac_header(head_skb); - struct sk_buff *frag_skb = head_skb; unsigned int offset = doffset; unsigned int tnl_hlen = skb_tnl_header_len(head_skb); unsigned int partial_segs = 0; unsigned int headroom; unsigned int len = head_skb->len; + struct sk_buff *frag_skb; + skb_frag_t *frag; __be16 proto; bool csum, sg; - int nfrags = skb_shinfo(head_skb)->nr_frags; int err = -ENOMEM; int i = 0; - int pos; - int dummy; + int nfrags, pos; + + if ((skb_shinfo(head_skb)->gso_type & SKB_GSO_DODGY) && + mss != GSO_BY_FRAGS && mss != skb_headlen(head_skb)) { + struct sk_buff *check_skb; + + for (check_skb = list_skb; check_skb; check_skb = check_skb->next) { + if (skb_headlen(check_skb) && !check_skb->head_frag) { + /* gso_size is untrusted, and we have a frag_list with + * a linear non head_frag item. + * + * If head_skb's headlen does not fit requested gso_size, + * it means that the frag_list members do NOT terminate + * on exact gso_size boundaries. Hence we cannot perform + * skb_frag_t page sharing. Therefore we must fallback to + * copying the frag_list skbs; we do so by disabling SG. + */ + features &= ~NETIF_F_SG; + break; + } + } + } __skb_push(head_skb, doffset); - proto = skb_network_protocol(head_skb, &dummy); + proto = skb_network_protocol(head_skb, NULL); if (unlikely(!proto)) return ERR_PTR(-EINVAL); @@ -3536,8 +4815,9 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, /* GSO partial only requires that we trim off any excess that * doesn't fit into an MSS sized block, so take care of that * now. + * Cap len to not accidentally hit GSO_BY_FRAGS. */ - partial_segs = len / mss; + partial_segs = min(len, GSO_BY_FRAGS - 1) / mss; if (partial_segs > 1) mss *= partial_segs; else @@ -3548,6 +4828,13 @@ normal: headroom = skb_headroom(head_skb); pos = skb_headlen(head_skb); + if (skb_orphan_frags(head_skb, GFP_ATOMIC)) + return ERR_PTR(-ENOMEM); + + nfrags = skb_shinfo(head_skb)->nr_frags; + frag = skb_shinfo(head_skb)->frags; + frag_skb = head_skb; + do { struct sk_buff *nskb; skb_frag_t *nskb_frag; @@ -3563,15 +4850,15 @@ normal: } hsize = skb_headlen(head_skb) - offset; - if (hsize < 0) - hsize = 0; - if (hsize > len || !sg) - hsize = len; - if (!hsize && i >= nfrags && skb_headlen(list_skb) && + if (hsize <= 0 && i >= nfrags && skb_headlen(list_skb) && (skb_headlen(list_skb) == len || sg)) { BUG_ON(skb_headlen(list_skb) > len); + nskb = skb_clone(list_skb, GFP_ATOMIC); + if (unlikely(!nskb)) + goto err; + i = 0; nfrags = skb_shinfo(list_skb)->nr_frags; frag = skb_shinfo(list_skb)->frags; @@ -3590,12 +4877,8 @@ normal: frag++; } - nskb = skb_clone(list_skb, GFP_ATOMIC); list_skb = list_skb->next; - if (unlikely(!nskb)) - goto err; - if (unlikely(pskb_trim(nskb, len))) { kfree_skb(nskb); goto err; @@ -3611,6 +4894,11 @@ normal: skb_release_head_state(nskb); __skb_push(nskb, doffset); } else { + if (hsize < 0) + hsize = 0; + if (hsize > len || !sg) + hsize = len; + nskb = __alloc_skb(hsize + doffset + headroom, GFP_ATOMIC, skb_alloc_rx_flag(head_skb), NUMA_NO_NODE); @@ -3641,14 +4929,20 @@ normal: goto perform_csum_check; if (!sg) { - if (!nskb->remcsum_offload) - nskb->ip_summed = CHECKSUM_NONE; - SKB_GSO_CB(nskb)->csum = - skb_copy_and_csum_bits(head_skb, offset, - skb_put(nskb, len), - len, 0); - SKB_GSO_CB(nskb)->csum_start = - skb_headroom(nskb) + doffset; + if (!csum) { + if (!nskb->remcsum_offload) + nskb->ip_summed = CHECKSUM_NONE; + SKB_GSO_CB(nskb)->csum = + skb_copy_and_csum_bits(head_skb, offset, + skb_put(nskb, + len), + len); + SKB_GSO_CB(nskb)->csum_start = + skb_headroom(nskb) + doffset; + } else { + if (skb_copy_bits(head_skb, offset, skb_put(nskb, len), len)) + goto err; + } continue; } @@ -3657,15 +4951,19 @@ normal: skb_copy_from_linear_data_offset(head_skb, offset, skb_put(nskb, hsize), hsize); - skb_shinfo(nskb)->tx_flags |= skb_shinfo(head_skb)->tx_flags & - SKBTX_SHARED_FRAG; + skb_shinfo(nskb)->flags |= skb_shinfo(head_skb)->flags & + SKBFL_SHARED_FRAG; - if (skb_orphan_frags(frag_skb, GFP_ATOMIC) || - skb_zerocopy_clone(nskb, frag_skb, GFP_ATOMIC)) + if (skb_zerocopy_clone(nskb, frag_skb, GFP_ATOMIC)) goto err; while (pos < offset + len) { if (i >= nfrags) { + if (skb_orphan_frags(list_skb, GFP_ATOMIC) || + skb_zerocopy_clone(nskb, list_skb, + GFP_ATOMIC)) + goto err; + i = 0; nfrags = skb_shinfo(list_skb)->nr_frags; frag = skb_shinfo(list_skb)->frags; @@ -3679,10 +4977,6 @@ normal: i--; frag--; } - if (skb_orphan_frags(frag_skb, GFP_ATOMIC) || - skb_zerocopy_clone(nskb, frag_skb, - GFP_ATOMIC)) - goto err; list_skb = list_skb->next; } @@ -3701,7 +4995,7 @@ normal: size = skb_frag_size(nskb_frag); if (pos < offset) { - nskb_frag->page_offset += offset - pos; + skb_frag_off_add(nskb_frag, offset - pos); skb_frag_size_sub(nskb_frag, offset - pos); } @@ -3788,118 +5082,6 @@ err: } EXPORT_SYMBOL_GPL(skb_segment); -int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) -{ - struct skb_shared_info *pinfo, *skbinfo = skb_shinfo(skb); - unsigned int offset = skb_gro_offset(skb); - unsigned int headlen = skb_headlen(skb); - unsigned int len = skb_gro_len(skb); - unsigned int delta_truesize; - struct sk_buff *lp; - - if (unlikely(p->len + len >= 65536)) - return -E2BIG; - - lp = NAPI_GRO_CB(p)->last; - pinfo = skb_shinfo(lp); - - if (headlen <= offset) { - skb_frag_t *frag; - skb_frag_t *frag2; - int i = skbinfo->nr_frags; - int nr_frags = pinfo->nr_frags + i; - - if (nr_frags > MAX_SKB_FRAGS) - goto merge; - - offset -= headlen; - pinfo->nr_frags = nr_frags; - skbinfo->nr_frags = 0; - - frag = pinfo->frags + nr_frags; - frag2 = skbinfo->frags + i; - do { - *--frag = *--frag2; - } while (--i); - - frag->page_offset += offset; - skb_frag_size_sub(frag, offset); - - /* all fragments truesize : remove (head size + sk_buff) */ - delta_truesize = skb->truesize - - SKB_TRUESIZE(skb_end_offset(skb)); - - skb->truesize -= skb->data_len; - skb->len -= skb->data_len; - skb->data_len = 0; - - NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE; - goto done; - } else if (skb->head_frag) { - int nr_frags = pinfo->nr_frags; - skb_frag_t *frag = pinfo->frags + nr_frags; - struct page *page = virt_to_head_page(skb->head); - unsigned int first_size = headlen - offset; - unsigned int first_offset; - - if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS) - goto merge; - - first_offset = skb->data - - (unsigned char *)page_address(page) + - offset; - - pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags; - - frag->page.p = page; - frag->page_offset = first_offset; - skb_frag_size_set(frag, first_size); - - memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags); - /* We dont need to clear skbinfo->nr_frags here */ - - delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff)); - NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD; - goto done; - } - -merge: - delta_truesize = skb->truesize; - if (offset > headlen) { - unsigned int eat = offset - headlen; - - skbinfo->frags[0].page_offset += eat; - skb_frag_size_sub(&skbinfo->frags[0], eat); - skb->data_len -= eat; - skb->len -= eat; - offset = headlen; - } - - __skb_pull(skb, offset); - - if (NAPI_GRO_CB(p)->last == p) - skb_shinfo(p)->frag_list = skb; - else - NAPI_GRO_CB(p)->last->next = skb; - NAPI_GRO_CB(p)->last = skb; - __skb_header_release(skb); - lp = p; - -done: - NAPI_GRO_CB(p)->count++; - p->data_len += len; - p->truesize += delta_truesize; - p->len += len; - if (lp != p) { - lp->data_len += len; - lp->truesize += delta_truesize; - lp->len += len; - } - NAPI_GRO_CB(skb)->same_flow = 1; - return 0; -} -EXPORT_SYMBOL_GPL(skb_gro_receive); - #ifdef CONFIG_SKB_EXTENSIONS #define SKB_EXT_ALIGN_VALUE 8 #define SKB_EXT_CHUNKSIZEOF(x) (ALIGN((sizeof(x)), SKB_EXT_ALIGN_VALUE) / SKB_EXT_ALIGN_VALUE) @@ -3911,24 +5093,37 @@ static const u8 skb_ext_type_len[] = { #ifdef CONFIG_XFRM [SKB_EXT_SEC_PATH] = SKB_EXT_CHUNKSIZEOF(struct sec_path), #endif +#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) + [TC_SKB_EXT] = SKB_EXT_CHUNKSIZEOF(struct tc_skb_ext), +#endif +#if IS_ENABLED(CONFIG_MPTCP) + [SKB_EXT_MPTCP] = SKB_EXT_CHUNKSIZEOF(struct mptcp_ext), +#endif +#if IS_ENABLED(CONFIG_MCTP_FLOWS) + [SKB_EXT_MCTP] = SKB_EXT_CHUNKSIZEOF(struct mctp_flow), +#endif +#if IS_ENABLED(CONFIG_INET_PSP) + [SKB_EXT_PSP] = SKB_EXT_CHUNKSIZEOF(struct psp_skb_ext), +#endif }; static __always_inline unsigned int skb_ext_total_length(void) { - return SKB_EXT_CHUNKSIZEOF(struct skb_ext) + -#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) - skb_ext_type_len[SKB_EXT_BRIDGE_NF] + -#endif -#ifdef CONFIG_XFRM - skb_ext_type_len[SKB_EXT_SEC_PATH] + -#endif - 0; + unsigned int l = SKB_EXT_CHUNKSIZEOF(struct skb_ext); + int i; + + for (i = 0; i < ARRAY_SIZE(skb_ext_type_len); i++) + l += skb_ext_type_len[i]; + + return l; } static void skb_extensions_init(void) { BUILD_BUG_ON(SKB_EXT_NUM >= 8); +#if !IS_ENABLED(CONFIG_KCOV_INSTRUMENT_ALL) BUILD_BUG_ON(skb_ext_total_length() > 255); +#endif skbuff_ext_cache = kmem_cache_create("skbuff_ext_cache", SKB_EXT_ALIGN_VALUE * skb_ext_total_length(), @@ -3940,20 +5135,44 @@ static void skb_extensions_init(void) static void skb_extensions_init(void) {} #endif +/* The SKB kmem_cache slab is critical for network performance. Never + * merge/alias the slab with similar sized objects. This avoids fragmentation + * that hurts performance of kmem_cache_{alloc,free}_bulk APIs. + */ +#ifndef CONFIG_SLUB_TINY +#define FLAG_SKB_NO_MERGE SLAB_NO_MERGE +#else /* CONFIG_SLUB_TINY - simple loop in kmem_cache_alloc_bulk */ +#define FLAG_SKB_NO_MERGE 0 +#endif + void __init skb_init(void) { - skbuff_head_cache = kmem_cache_create_usercopy("skbuff_head_cache", + net_hotdata.skbuff_cache = kmem_cache_create_usercopy("skbuff_head_cache", sizeof(struct sk_buff), 0, - SLAB_HWCACHE_ALIGN|SLAB_PANIC, + SLAB_HWCACHE_ALIGN|SLAB_PANIC| + FLAG_SKB_NO_MERGE, offsetof(struct sk_buff, cb), sizeof_field(struct sk_buff, cb), NULL); - skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache", + skbuff_cache_size = kmem_cache_size(net_hotdata.skbuff_cache); + + net_hotdata.skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache", sizeof(struct sk_buff_fclones), 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + /* usercopy should only access first SKB_SMALL_HEAD_HEADROOM bytes. + * struct skb_shared_info is located at the end of skb->head, + * and should not be copied to/from user. + */ + net_hotdata.skb_small_head_cache = kmem_cache_create_usercopy("skbuff_small_head", + SKB_SMALL_HEAD_CACHE_SIZE, + 0, + SLAB_HWCACHE_ALIGN | SLAB_PANIC, + 0, + SKB_SMALL_HEAD_HEADROOM, + NULL); skb_extensions_init(); } @@ -3993,7 +5212,7 @@ __skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len, if (copy > len) copy = len; sg_set_page(&sg[elt], skb_frag_page(frag), copy, - frag->page_offset+offset-start); + skb_frag_off(frag) + offset - start); elt++; if (!(len -= copy)) return elt; @@ -4070,7 +5289,7 @@ EXPORT_SYMBOL_GPL(skb_to_sgvec); * 3. sg_unmark_end * 4. skb_to_sgvec(payload2) * - * When mapping mutilple payload conditionally, skb_to_sgvec_nomark + * When mapping multiple payload conditionally, skb_to_sgvec_nomark * is more preferable. */ int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, @@ -4110,7 +5329,7 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer) * at the moment even if they are anonymous). */ if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) && - __pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL) + !__pskb_pull_tail(skb, __skb_pagelen(skb))) return -ENOMEM; /* Easy case. Most of packets will go this way. */ @@ -4214,7 +5433,7 @@ static void skb_set_err_queue(struct sk_buff *skb) int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) { if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= - (unsigned int)sk->sk_rcvbuf) + (unsigned int)READ_ONCE(sk->sk_rcvbuf)) return -ENOMEM; skb_orphan(skb); @@ -4228,7 +5447,7 @@ int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) skb_queue_tail(&sk->sk_error_queue, skb); if (!sock_flag(sk, SOCK_DEAD)) - sk->sk_error_report(sk); + sk_error_report(sk); return 0; } EXPORT_SYMBOL(sock_queue_err_skb); @@ -4246,12 +5465,15 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk) bool icmp_next = false; unsigned long flags; + if (skb_queue_empty_lockless(q)) + return NULL; + spin_lock_irqsave(&q->lock, flags); skb = __skb_dequeue(q); if (skb && (skb_next = skb_peek(q))) { icmp_next = is_icmp_err_skb(skb_next); if (icmp_next) - sk->sk_err = SKB_EXT_ERR(skb_next)->ee.ee_origin; + sk->sk_err = SKB_EXT_ERR(skb_next)->ee.ee_errno; } spin_unlock_irqrestore(&q->lock, flags); @@ -4259,7 +5481,7 @@ struct sk_buff *sock_dequeue_err_skb(struct sock *sk) sk->sk_err = 0; if (skb_next) - sk->sk_error_report(sk); + sk_error_report(sk); return skb; } @@ -4316,11 +5538,10 @@ static void __skb_complete_tx_timestamp(struct sk_buff *skb, serr->ee.ee_info = tstype; serr->opt_stats = opt_stats; serr->header.h4.iif = skb->dev ? skb->dev->ifindex : 0; - if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) { + if (READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID) { serr->ee.ee_data = skb_shinfo(skb)->tskey; - if (sk->sk_protocol == IPPROTO_TCP && - sk->sk_type == SOCK_STREAM) - serr->ee.ee_data -= sk->sk_tskey; + if (sk_is_tcp(sk)) + serr->ee.ee_data -= atomic_read(&sk->sk_tskey); } err = sock_queue_err_skb(sk, skb); @@ -4333,7 +5554,7 @@ static bool skb_may_tx_timestamp(struct sock *sk, bool tsonly) { bool ret; - if (likely(sysctl_tstamp_allow_data || tsonly)) + if (likely(tsonly || READ_ONCE(sock_net(sk)->core.sysctl_tstamp_allow_data))) return true; read_lock_bh(&sk->sk_callback_lock); @@ -4366,36 +5587,99 @@ err: } EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp); +static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb, + struct skb_shared_hwtstamps *hwtstamps, + int tstype) +{ + switch (tstype) { + case SCM_TSTAMP_SCHED: + return skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP; + case SCM_TSTAMP_SND: + return skb_shinfo(skb)->tx_flags & (hwtstamps ? SKBTX_HW_TSTAMP_NOBPF : + SKBTX_SW_TSTAMP); + case SCM_TSTAMP_ACK: + return TCP_SKB_CB(skb)->txstamp_ack & TSTAMP_ACK_SK; + case SCM_TSTAMP_COMPLETION: + return skb_shinfo(skb)->tx_flags & SKBTX_COMPLETION_TSTAMP; + } + + return false; +} + +static void skb_tstamp_tx_report_bpf_timestamping(struct sk_buff *skb, + struct skb_shared_hwtstamps *hwtstamps, + struct sock *sk, + int tstype) +{ + int op; + + switch (tstype) { + case SCM_TSTAMP_SCHED: + op = BPF_SOCK_OPS_TSTAMP_SCHED_CB; + break; + case SCM_TSTAMP_SND: + if (hwtstamps) { + op = BPF_SOCK_OPS_TSTAMP_SND_HW_CB; + *skb_hwtstamps(skb) = *hwtstamps; + } else { + op = BPF_SOCK_OPS_TSTAMP_SND_SW_CB; + } + break; + case SCM_TSTAMP_ACK: + op = BPF_SOCK_OPS_TSTAMP_ACK_CB; + break; + default: + return; + } + + bpf_skops_tx_timestamping(sk, skb, op); +} + void __skb_tstamp_tx(struct sk_buff *orig_skb, + const struct sk_buff *ack_skb, struct skb_shared_hwtstamps *hwtstamps, struct sock *sk, int tstype) { struct sk_buff *skb; bool tsonly, opt_stats = false; + u32 tsflags; if (!sk) return; - if (!hwtstamps && !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) && + if (skb_shinfo(orig_skb)->tx_flags & SKBTX_BPF) + skb_tstamp_tx_report_bpf_timestamping(orig_skb, hwtstamps, + sk, tstype); + + if (!skb_tstamp_tx_report_so_timestamping(orig_skb, hwtstamps, tstype)) + return; + + tsflags = READ_ONCE(sk->sk_tsflags); + if (!hwtstamps && !(tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) && skb_shinfo(orig_skb)->tx_flags & SKBTX_IN_PROGRESS) return; - tsonly = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TSONLY; + tsonly = tsflags & SOF_TIMESTAMPING_OPT_TSONLY; if (!skb_may_tx_timestamp(sk, tsonly)) return; if (tsonly) { #ifdef CONFIG_INET - if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS) && - sk->sk_protocol == IPPROTO_TCP && - sk->sk_type == SOCK_STREAM) { - skb = tcp_get_timestamping_opt_stats(sk); + if ((tsflags & SOF_TIMESTAMPING_OPT_STATS) && + sk_is_tcp(sk)) { + skb = tcp_get_timestamping_opt_stats(sk, orig_skb, + ack_skb); opt_stats = true; } else #endif skb = alloc_skb(0, GFP_ATOMIC); } else { skb = skb_clone(orig_skb, GFP_ATOMIC); + + if (skb_orphan_frags_rx(skb, GFP_ATOMIC)) { + kfree_skb(skb); + return; + } } if (!skb) return; @@ -4409,7 +5693,7 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, if (hwtstamps) *skb_hwtstamps(skb) = *hwtstamps; else - skb->tstamp = ktime_get_real(); + __net_timestamp(skb); __skb_complete_tx_timestamp(skb, sk, tstype, opt_stats); } @@ -4418,11 +5702,12 @@ EXPORT_SYMBOL_GPL(__skb_tstamp_tx); void skb_tstamp_tx(struct sk_buff *orig_skb, struct skb_shared_hwtstamps *hwtstamps) { - return __skb_tstamp_tx(orig_skb, hwtstamps, orig_skb->sk, + return __skb_tstamp_tx(orig_skb, NULL, hwtstamps, orig_skb->sk, SCM_TSTAMP_SND); } EXPORT_SYMBOL_GPL(skb_tstamp_tx); +#ifdef CONFIG_WIRELESS void skb_complete_wifi_ack(struct sk_buff *skb, bool acked) { struct sock *sk = skb->sk; @@ -4448,6 +5733,7 @@ void skb_complete_wifi_ack(struct sk_buff *skb, bool acked) kfree_skb(skb); } EXPORT_SYMBOL_GPL(skb_complete_wifi_ack); +#endif /* CONFIG_WIRELESS */ /** * skb_partial_csum_set - set up and verify partial csum values for packet @@ -4466,7 +5752,7 @@ bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off) u32 csum_end = (u32)start + (u32)off + sizeof(__sum16); u32 csum_start = skb_headroom(skb) + (u32)start; - if (unlikely(csum_start > U16_MAX || csum_end > skb_headlen(skb))) { + if (unlikely(csum_start >= U16_MAX || csum_end > skb_headlen(skb))) { net_warn_ratelimited("bad partial csum: csum=%u/%u headroom=%u headlen=%u\n", start, off, skb_headroom(skb), skb_headlen(skb)); return false; @@ -4474,7 +5760,7 @@ bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off) skb->ip_summed = CHECKSUM_PARTIAL; skb->csum_start = csum_start; skb->csum_offset = off; - skb_set_transport_header(skb, start); + skb->transport_header = csum_start; return true; } EXPORT_SYMBOL_GPL(skb_partial_csum_set); @@ -4506,9 +5792,9 @@ static __sum16 *skb_checksum_setup_ip(struct sk_buff *skb, typeof(IPPROTO_IP) proto, unsigned int off) { - switch (proto) { - int err; + int err; + switch (proto) { case IPPROTO_TCP: err = skb_maybe_pull_tail(skb, off + sizeof(struct tcphdr), off + MAX_TCP_HDR_LEN); @@ -4551,7 +5837,7 @@ static int skb_checksum_setup_ipv4(struct sk_buff *skb, bool recalculate) if (err < 0) goto out; - if (ip_hdr(skb)->frag_off & htons(IP_OFFSET | IP_MF)) + if (ip_is_fragment(ip_hdr(skb))) fragment = true; off = ip_hdrlen(skb); @@ -4808,7 +6094,7 @@ void kfree_skb_partial(struct sk_buff *skb, bool head_stolen) { if (head_stolen) { skb_release_head_state(skb); - kmem_cache_free(skbuff_head_cache, skb); + kmem_cache_free(net_hotdata.skbuff_cache, skb); } else { __kfree_skb(skb); } @@ -4833,7 +6119,19 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, if (skb_cloned(to)) return false; - if (len <= skb_tailroom(to)) { + /* In general, avoid mixing page_pool and non-page_pool allocated + * pages within the same SKB. In theory we could take full + * references if @from is cloned and !@to->pp_recycle but its + * tricky (due to potential race with the clone disappearing) and + * rare, so not worth dealing with. + */ + if (to->pp_recycle != from->pp_recycle) + return false; + + if (skb_frags_readable(from) != skb_frags_readable(to)) + return false; + + if (len <= skb_tailroom(to) && skb_frags_readable(from)) { if (len) BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len)); *delta_truesize = 0; @@ -4887,8 +6185,10 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, /* if the skb is not cloned this does nothing * since we set nr_frags to 0. */ - for (i = 0; i < from_shinfo->nr_frags; i++) - __skb_frag_ref(&from_shinfo->frags[i]); + if (skb_pp_frag_ref(from)) { + for (i = 0; i < from_shinfo->nr_frags; i++) + __skb_frag_ref(&from_shinfo->frags[i]); + } to->truesize += delta; to->len += len; @@ -4905,7 +6205,7 @@ EXPORT_SYMBOL(skb_try_coalesce); * @skb: buffer to clean * @xnet: packet is crossing netns * - * skb_scrub_packet can be used after encapsulating or decapsulting a packet + * skb_scrub_packet can be used after encapsulating or decapsulating a packet * into/from a tunnel. Some information have to be cleared during these * operations. * skb_scrub_packet can also be used to clean a skb before injecting it in @@ -4918,168 +6218,28 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet) skb->skb_iif = 0; skb->ignore_df = 0; skb_dst_drop(skb); - secpath_reset(skb); - nf_reset(skb); + skb_ext_reset(skb); + nf_reset_ct(skb); nf_reset_trace(skb); #ifdef CONFIG_NET_SWITCHDEV skb->offload_fwd_mark = 0; skb->offload_l3_fwd_mark = 0; #endif + ipvs_reset(skb); if (!xnet) return; - ipvs_reset(skb); skb->mark = 0; - skb->tstamp = 0; + skb_clear_tstamp(skb); } EXPORT_SYMBOL_GPL(skb_scrub_packet); -/** - * skb_gso_transport_seglen - Return length of individual segments of a gso packet - * - * @skb: GSO skb - * - * skb_gso_transport_seglen is used to determine the real size of the - * individual segments, including Layer4 headers (TCP/UDP). - * - * The MAC/L2 or network (IP, IPv6) headers are not accounted for. - */ -static unsigned int skb_gso_transport_seglen(const struct sk_buff *skb) -{ - const struct skb_shared_info *shinfo = skb_shinfo(skb); - unsigned int thlen = 0; - - if (skb->encapsulation) { - thlen = skb_inner_transport_header(skb) - - skb_transport_header(skb); - - if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) - thlen += inner_tcp_hdrlen(skb); - } else if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) { - thlen = tcp_hdrlen(skb); - } else if (unlikely(skb_is_gso_sctp(skb))) { - thlen = sizeof(struct sctphdr); - } else if (shinfo->gso_type & SKB_GSO_UDP_L4) { - thlen = sizeof(struct udphdr); - } - /* UFO sets gso_size to the size of the fragmentation - * payload, i.e. the size of the L4 (UDP) header is already - * accounted for. - */ - return thlen + shinfo->gso_size; -} - -/** - * skb_gso_network_seglen - Return length of individual segments of a gso packet - * - * @skb: GSO skb - * - * skb_gso_network_seglen is used to determine the real size of the - * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP). - * - * The MAC/L2 header is not accounted for. - */ -static unsigned int skb_gso_network_seglen(const struct sk_buff *skb) -{ - unsigned int hdr_len = skb_transport_header(skb) - - skb_network_header(skb); - - return hdr_len + skb_gso_transport_seglen(skb); -} - -/** - * skb_gso_mac_seglen - Return length of individual segments of a gso packet - * - * @skb: GSO skb - * - * skb_gso_mac_seglen is used to determine the real size of the - * individual segments, including MAC/L2, Layer3 (IP, IPv6) and L4 - * headers (TCP/UDP). - */ -static unsigned int skb_gso_mac_seglen(const struct sk_buff *skb) -{ - unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb); - - return hdr_len + skb_gso_transport_seglen(skb); -} - -/** - * skb_gso_size_check - check the skb size, considering GSO_BY_FRAGS - * - * There are a couple of instances where we have a GSO skb, and we - * want to determine what size it would be after it is segmented. - * - * We might want to check: - * - L3+L4+payload size (e.g. IP forwarding) - * - L2+L3+L4+payload size (e.g. sanity check before passing to driver) - * - * This is a helper to do that correctly considering GSO_BY_FRAGS. - * - * @skb: GSO skb - * - * @seg_len: The segmented length (from skb_gso_*_seglen). In the - * GSO_BY_FRAGS case this will be [header sizes + GSO_BY_FRAGS]. - * - * @max_len: The maximum permissible length. - * - * Returns true if the segmented length <= max length. - */ -static inline bool skb_gso_size_check(const struct sk_buff *skb, - unsigned int seg_len, - unsigned int max_len) { - const struct skb_shared_info *shinfo = skb_shinfo(skb); - const struct sk_buff *iter; - - if (shinfo->gso_size != GSO_BY_FRAGS) - return seg_len <= max_len; - - /* Undo this so we can re-use header sizes */ - seg_len -= GSO_BY_FRAGS; - - skb_walk_frags(skb, iter) { - if (seg_len + skb_headlen(iter) > max_len) - return false; - } - - return true; -} - -/** - * skb_gso_validate_network_len - Will a split GSO skb fit into a given MTU? - * - * @skb: GSO skb - * @mtu: MTU to validate against - * - * skb_gso_validate_network_len validates if a given skb will fit a - * wanted MTU once split. It considers L3 headers, L4 headers, and the - * payload. - */ -bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu) -{ - return skb_gso_size_check(skb, skb_gso_network_seglen(skb), mtu); -} -EXPORT_SYMBOL_GPL(skb_gso_validate_network_len); - -/** - * skb_gso_validate_mac_len - Will a split GSO skb fit in a given length? - * - * @skb: GSO skb - * @len: length to validate against - * - * skb_gso_validate_mac_len validates if a given skb will fit a wanted - * length once split, including L2, L3 and L4 headers and the payload. - */ -bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len) -{ - return skb_gso_size_check(skb, skb_gso_mac_seglen(skb), len); -} -EXPORT_SYMBOL_GPL(skb_gso_validate_mac_len); - static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb) { - int mac_len; + int mac_len, meta_len; + void *meta; if (skb_cow(skb, skb_headroom(skb)) < 0) { kfree_skb(skb); @@ -5091,6 +6251,13 @@ static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb) memmove(skb_mac_header(skb) + VLAN_HLEN, skb_mac_header(skb), mac_len - VLAN_HLEN - ETH_TLEN); } + + meta_len = skb_metadata_len(skb); + if (meta_len) { + meta = skb_metadata_end(skb) - meta_len; + memmove(meta + VLAN_HLEN, meta, meta_len); + } + skb->mac_header += VLAN_HLEN; return skb; } @@ -5108,8 +6275,8 @@ struct sk_buff *skb_vlan_untag(struct sk_buff *skb) skb = skb_share_check(skb, GFP_ATOMIC); if (unlikely(!skb)) goto err_free; - - if (unlikely(!pskb_may_pull(skb, VLAN_HLEN))) + /* We may access the two bytes after vlan_hdr in vlan_set_encap_proto(). */ + if (unlikely(!pskb_may_pull(skb, VLAN_HLEN + sizeof(unsigned short)))) goto err_free; vhdr = (struct vlan_hdr *)skb->data; @@ -5124,7 +6291,8 @@ struct sk_buff *skb_vlan_untag(struct sk_buff *skb) goto err_free; skb_reset_network_header(skb); - skb_reset_transport_header(skb); + if (!skb_transport_header_was_set(skb)) + skb_reset_transport_header(skb); skb_reset_mac_len(skb); return skb; @@ -5135,7 +6303,7 @@ err_free: } EXPORT_SYMBOL(skb_vlan_untag); -int skb_ensure_writable(struct sk_buff *skb, int write_len) +int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len) { if (!pskb_may_pull(skb, write_len)) return -ENOMEM; @@ -5147,12 +6315,36 @@ int skb_ensure_writable(struct sk_buff *skb, int write_len) } EXPORT_SYMBOL(skb_ensure_writable); +int skb_ensure_writable_head_tail(struct sk_buff *skb, struct net_device *dev) +{ + int needed_headroom = dev->needed_headroom; + int needed_tailroom = dev->needed_tailroom; + + /* For tail taggers, we need to pad short frames ourselves, to ensure + * that the tail tag does not fail at its role of being at the end of + * the packet, once the conduit interface pads the frame. Account for + * that pad length here, and pad later. + */ + if (unlikely(needed_tailroom && skb->len < ETH_ZLEN)) + needed_tailroom += ETH_ZLEN - skb->len; + /* skb_headroom() returns unsigned int... */ + needed_headroom = max_t(int, needed_headroom - skb_headroom(skb), 0); + needed_tailroom = max_t(int, needed_tailroom - skb_tailroom(skb), 0); + + if (likely(!needed_headroom && !needed_tailroom && !skb_cloned(skb))) + /* No reallocation needed, yay! */ + return 0; + + return pskb_expand_head(skb, needed_headroom, needed_tailroom, + GFP_ATOMIC); +} +EXPORT_SYMBOL(skb_ensure_writable_head_tail); + /* remove VLAN header from packet and update csum accordingly. * expects a non skb_vlan_tag_present skb with a vlan tag payload */ int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci) { - struct vlan_hdr *vhdr; int offset = skb->data - skb_mac_header(skb); int err; @@ -5168,13 +6360,8 @@ int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci) skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN); - vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN); - *vlan_tci = ntohs(vhdr->h_vlan_TCI); - - memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN); - __skb_pull(skb, VLAN_HLEN); + vlan_remove_tag(skb, vlan_tci); - vlan_set_encap_proto(skb, vhdr); skb->mac_header += VLAN_HLEN; if (skb_network_offset(skb) < ETH_HLEN) @@ -5240,7 +6427,7 @@ int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) return err; skb->protocol = skb->vlan_proto; - skb->mac_len += VLAN_HLEN; + skb->network_header -= VLAN_HLEN; skb_postpush_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN); } @@ -5250,11 +6437,257 @@ int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) EXPORT_SYMBOL(skb_vlan_push); /** + * skb_eth_pop() - Drop the Ethernet header at the head of a packet + * + * @skb: Socket buffer to modify + * + * Drop the Ethernet header of @skb. + * + * Expects that skb->data points to the mac header and that no VLAN tags are + * present. + * + * Returns 0 on success, -errno otherwise. + */ +int skb_eth_pop(struct sk_buff *skb) +{ + if (!pskb_may_pull(skb, ETH_HLEN) || skb_vlan_tagged(skb) || + skb_network_offset(skb) < ETH_HLEN) + return -EPROTO; + + skb_pull_rcsum(skb, ETH_HLEN); + skb_reset_mac_header(skb); + skb_reset_mac_len(skb); + + return 0; +} +EXPORT_SYMBOL(skb_eth_pop); + +/** + * skb_eth_push() - Add a new Ethernet header at the head of a packet + * + * @skb: Socket buffer to modify + * @dst: Destination MAC address of the new header + * @src: Source MAC address of the new header + * + * Prepend @skb with a new Ethernet header. + * + * Expects that skb->data points to the mac header, which must be empty. + * + * Returns 0 on success, -errno otherwise. + */ +int skb_eth_push(struct sk_buff *skb, const unsigned char *dst, + const unsigned char *src) +{ + struct ethhdr *eth; + int err; + + if (skb_network_offset(skb) || skb_vlan_tag_present(skb)) + return -EPROTO; + + err = skb_cow_head(skb, sizeof(*eth)); + if (err < 0) + return err; + + skb_push(skb, sizeof(*eth)); + skb_reset_mac_header(skb); + skb_reset_mac_len(skb); + + eth = eth_hdr(skb); + ether_addr_copy(eth->h_dest, dst); + ether_addr_copy(eth->h_source, src); + eth->h_proto = skb->protocol; + + skb_postpush_rcsum(skb, eth, sizeof(*eth)); + + return 0; +} +EXPORT_SYMBOL(skb_eth_push); + +/* Update the ethertype of hdr and the skb csum value if required. */ +static void skb_mod_eth_type(struct sk_buff *skb, struct ethhdr *hdr, + __be16 ethertype) +{ + if (skb->ip_summed == CHECKSUM_COMPLETE) { + __be16 diff[] = { ~hdr->h_proto, ethertype }; + + skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum); + } + + hdr->h_proto = ethertype; +} + +/** + * skb_mpls_push() - push a new MPLS header after mac_len bytes from start of + * the packet + * + * @skb: buffer + * @mpls_lse: MPLS label stack entry to push + * @mpls_proto: ethertype of the new MPLS header (expects 0x8847 or 0x8848) + * @mac_len: length of the MAC header + * @ethernet: flag to indicate if the resulting packet after skb_mpls_push is + * ethernet + * + * Expects skb->data at mac header. + * + * Returns 0 on success, -errno otherwise. + */ +int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto, + int mac_len, bool ethernet) +{ + struct mpls_shim_hdr *lse; + int err; + + if (unlikely(!eth_p_mpls(mpls_proto))) + return -EINVAL; + + /* Networking stack does not allow simultaneous Tunnel and MPLS GSO. */ + if (skb->encapsulation) + return -EINVAL; + + err = skb_cow_head(skb, MPLS_HLEN); + if (unlikely(err)) + return err; + + if (!skb->inner_protocol) { + skb_set_inner_network_header(skb, skb_network_offset(skb)); + skb_set_inner_protocol(skb, skb->protocol); + } + + skb_push(skb, MPLS_HLEN); + memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb), + mac_len); + skb_reset_mac_header(skb); + skb_set_network_header(skb, mac_len); + skb_reset_mac_len(skb); + + lse = mpls_hdr(skb); + lse->label_stack_entry = mpls_lse; + skb_postpush_rcsum(skb, lse, MPLS_HLEN); + + if (ethernet && mac_len >= ETH_HLEN) + skb_mod_eth_type(skb, eth_hdr(skb), mpls_proto); + skb->protocol = mpls_proto; + + return 0; +} +EXPORT_SYMBOL_GPL(skb_mpls_push); + +/** + * skb_mpls_pop() - pop the outermost MPLS header + * + * @skb: buffer + * @next_proto: ethertype of header after popped MPLS header + * @mac_len: length of the MAC header + * @ethernet: flag to indicate if the packet is ethernet + * + * Expects skb->data at mac header. + * + * Returns 0 on success, -errno otherwise. + */ +int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len, + bool ethernet) +{ + int err; + + if (unlikely(!eth_p_mpls(skb->protocol))) + return 0; + + err = skb_ensure_writable(skb, mac_len + MPLS_HLEN); + if (unlikely(err)) + return err; + + skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN); + memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb), + mac_len); + + __skb_pull(skb, MPLS_HLEN); + skb_reset_mac_header(skb); + skb_set_network_header(skb, mac_len); + + if (ethernet && mac_len >= ETH_HLEN) { + struct ethhdr *hdr; + + /* use mpls_hdr() to get ethertype to account for VLANs. */ + hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN); + skb_mod_eth_type(skb, hdr, next_proto); + } + skb->protocol = next_proto; + + return 0; +} +EXPORT_SYMBOL_GPL(skb_mpls_pop); + +/** + * skb_mpls_update_lse() - modify outermost MPLS header and update csum + * + * @skb: buffer + * @mpls_lse: new MPLS label stack entry to update to + * + * Expects skb->data at mac header. + * + * Returns 0 on success, -errno otherwise. + */ +int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse) +{ + int err; + + if (unlikely(!eth_p_mpls(skb->protocol))) + return -EINVAL; + + err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN); + if (unlikely(err)) + return err; + + if (skb->ip_summed == CHECKSUM_COMPLETE) { + __be32 diff[] = { ~mpls_hdr(skb)->label_stack_entry, mpls_lse }; + + skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum); + } + + mpls_hdr(skb)->label_stack_entry = mpls_lse; + + return 0; +} +EXPORT_SYMBOL_GPL(skb_mpls_update_lse); + +/** + * skb_mpls_dec_ttl() - decrement the TTL of the outermost MPLS header + * + * @skb: buffer + * + * Expects skb->data at mac header. + * + * Returns 0 on success, -errno otherwise. + */ +int skb_mpls_dec_ttl(struct sk_buff *skb) +{ + u32 lse; + u8 ttl; + + if (unlikely(!eth_p_mpls(skb->protocol))) + return -EINVAL; + + if (!pskb_may_pull(skb, skb_network_offset(skb) + MPLS_HLEN)) + return -ENOMEM; + + lse = be32_to_cpu(mpls_hdr(skb)->label_stack_entry); + ttl = (lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT; + if (!--ttl) + return -EINVAL; + + lse &= ~MPLS_LS_TTL_MASK; + lse |= ttl << MPLS_LS_TTL_SHIFT; + + return skb_mpls_update_lse(skb, cpu_to_be32(lse)); +} +EXPORT_SYMBOL_GPL(skb_mpls_dec_ttl); + +/** * alloc_skb_with_frags - allocate skb with page frags * * @header_len: size of linear part * @data_len: needed length in frags - * @max_page_order: max page order desired. + * @order: max page order desired. * @errcode: pointer to error code if any * @gfp_mask: allocation mask * @@ -5262,21 +6695,17 @@ EXPORT_SYMBOL(skb_vlan_push); */ struct sk_buff *alloc_skb_with_frags(unsigned long header_len, unsigned long data_len, - int max_page_order, + int order, int *errcode, gfp_t gfp_mask) { - int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT; unsigned long chunk; struct sk_buff *skb; struct page *page; - int i; + int nr_frags = 0; *errcode = -EMSGSIZE; - /* Note this test could be relaxed, if we succeed to allocate - * high order pages... - */ - if (npages > MAX_SKB_FRAGS) + if (unlikely(data_len > MAX_SKB_FRAGS * (PAGE_SIZE << order))) return NULL; *errcode = -ENOBUFS; @@ -5284,34 +6713,32 @@ struct sk_buff *alloc_skb_with_frags(unsigned long header_len, if (!skb) return NULL; - skb->truesize += npages << PAGE_SHIFT; - - for (i = 0; npages > 0; i++) { - int order = max_page_order; - - while (order) { - if (npages >= 1 << order) { - page = alloc_pages((gfp_mask & ~__GFP_DIRECT_RECLAIM) | - __GFP_COMP | - __GFP_NOWARN, - order); - if (page) - goto fill_page; - /* Do not retry other high order allocations */ - order = 1; - max_page_order = 0; - } + while (data_len) { + if (nr_frags == MAX_SKB_FRAGS) + goto failure; + while (order && PAGE_ALIGN(data_len) < (PAGE_SIZE << order)) order--; + + if (order) { + page = alloc_pages((gfp_mask & ~__GFP_DIRECT_RECLAIM) | + __GFP_COMP | + __GFP_NOWARN, + order); + if (!page) { + order--; + continue; + } + } else { + page = alloc_page(gfp_mask); + if (!page) + goto failure; } - page = alloc_page(gfp_mask); - if (!page) - goto failure; -fill_page: chunk = min_t(unsigned long, data_len, PAGE_SIZE << order); - skb_fill_page_desc(skb, i, page, 0, chunk); + skb_fill_page_desc(skb, nr_frags, page, 0, chunk); + nr_frags++; + skb->truesize += (PAGE_SIZE << order); data_len -= chunk; - npages -= 1 << order; } return skb; @@ -5326,21 +6753,17 @@ static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off, const int headlen, gfp_t gfp_mask) { int i; - int size = skb_end_offset(skb); + unsigned int size = skb_end_offset(skb); int new_hlen = headlen - off; u8 *data; - size = SKB_DATA_ALIGN(size); - if (skb_pfmemalloc(skb)) gfp_mask |= __GFP_MEMALLOC; - data = kmalloc_reserve(size + - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), - gfp_mask, NUMA_NO_NODE, NULL); + + data = kmalloc_reserve(&size, gfp_mask, NUMA_NO_NODE, NULL); if (!data) return -ENOMEM; - - size = SKB_WITH_OVERHEAD(ksize(data)); + size = SKB_WITH_OVERHEAD(size); /* Copy real data, and all frags */ skb_copy_from_linear_data_offset(skb, off, data, new_hlen); @@ -5353,14 +6776,14 @@ static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off, if (skb_cloned(skb)) { /* drop the old head gracefully */ if (skb_orphan_frags(skb, gfp_mask)) { - kfree(data); + skb_kfree_head(data, size); return -ENOMEM; } for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) skb_frag_ref(skb, i); if (skb_has_frag_list(skb)) skb_clone_fraglist(skb); - skb_release_data(skb); + skb_release_data(skb, SKB_CONSUMED); } else { /* we can reuse existing recount- all we did was * relocate values @@ -5371,11 +6794,7 @@ static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off, skb->head = data; skb->data = data; skb->head_frag = 0; -#ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->end = size; -#else - skb->end = skb->head + size; -#endif + skb_set_end_offset(skb, size); skb_set_tail_pointer(skb, skb_headlen(skb)); skb_headers_offset_update(skb, 0); skb->cloned = 0; @@ -5391,8 +6810,7 @@ static int pskb_carve(struct sk_buff *skb, const u32 off, gfp_t gfp); /* carve out the first eat bytes from skb's frag_list. May recurse into * pskb_carve() */ -static int pskb_carve_frag_list(struct sk_buff *skb, - struct skb_shared_info *shinfo, int eat, +static int pskb_carve_frag_list(struct skb_shared_info *shinfo, int eat, gfp_t gfp_mask) { struct sk_buff *list = shinfo->frag_list; @@ -5432,7 +6850,7 @@ static int pskb_carve_frag_list(struct sk_buff *skb, /* Free pulled out fragments. */ while ((list = shinfo->frag_list) != insp) { shinfo->frag_list = list->next; - kfree_skb(list); + consume_skb(list); } /* And insert new clone at head. */ if (clone) { @@ -5449,28 +6867,23 @@ static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off, int pos, gfp_t gfp_mask) { int i, k = 0; - int size = skb_end_offset(skb); + unsigned int size = skb_end_offset(skb); u8 *data; const int nfrags = skb_shinfo(skb)->nr_frags; struct skb_shared_info *shinfo; - size = SKB_DATA_ALIGN(size); - if (skb_pfmemalloc(skb)) gfp_mask |= __GFP_MEMALLOC; - data = kmalloc_reserve(size + - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), - gfp_mask, NUMA_NO_NODE, NULL); + + data = kmalloc_reserve(&size, gfp_mask, NUMA_NO_NODE, NULL); if (!data) return -ENOMEM; - - size = SKB_WITH_OVERHEAD(ksize(data)); + size = SKB_WITH_OVERHEAD(size); memcpy((struct skb_shared_info *)(data + size), - skb_shinfo(skb), offsetof(struct skb_shared_info, - frags[skb_shinfo(skb)->nr_frags])); + skb_shinfo(skb), offsetof(struct skb_shared_info, frags[0])); if (skb_orphan_frags(skb, gfp_mask)) { - kfree(data); + skb_kfree_head(data, size); return -ENOMEM; } shinfo = (struct skb_shared_info *)(data + size); @@ -5489,7 +6902,7 @@ static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off, * where splitting is expensive. * 2. Split is accurately. We make this. */ - shinfo->frags[0].page_offset += off - pos; + skb_frag_off_add(&shinfo->frags[0], off - pos); skb_frag_size_sub(&shinfo->frags[0], off - pos); } skb_frag_ref(skb, i); @@ -5501,20 +6914,20 @@ static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off, if (skb_has_frag_list(skb)) skb_clone_fraglist(skb); - if (k == 0) { - /* split line is in frag list */ - pskb_carve_frag_list(skb, shinfo, off - pos, gfp_mask); + /* split line is in frag list */ + if (k == 0 && pskb_carve_frag_list(shinfo, off - pos, gfp_mask)) { + /* skb_frag_unref() is not needed here as shinfo->nr_frags = 0. */ + if (skb_has_frag_list(skb)) + kfree_skb_list(skb_shinfo(skb)->frag_list); + skb_kfree_head(data, size); + return -ENOMEM; } - skb_release_data(skb); + skb_release_data(skb, SKB_CONSUMED); skb->head = data; skb->head_frag = 0; skb->data = data; -#ifdef NET_SKBUFF_DATA_USES_OFFSET - skb->end = size; -#else - skb->end = skb->head + size; -#endif + skb_set_end_offset(skb, size); skb_reset_tail_pointer(skb); skb_headers_offset_update(skb, 0); skb->cloned = 0; @@ -5573,7 +6986,7 @@ void skb_condense(struct sk_buff *skb) { if (skb->data_len) { if (skb->data_len > skb->end - skb->tail || - skb_cloned(skb)) + skb_cloned(skb) || !skb_frags_readable(skb)) return; /* Nice, we can free page frag(s) right now */ @@ -5588,6 +7001,7 @@ void skb_condense(struct sk_buff *skb) */ skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); } +EXPORT_SYMBOL(skb_condense); #ifdef CONFIG_SKB_EXTENSIONS static void *skb_ext_get_ptr(struct skb_ext *ext, enum skb_ext_id id) @@ -5595,9 +7009,18 @@ static void *skb_ext_get_ptr(struct skb_ext *ext, enum skb_ext_id id) return (void *)ext + (ext->offset[id] * SKB_EXT_ALIGN_VALUE); } -static struct skb_ext *skb_ext_alloc(void) +/** + * __skb_ext_alloc - allocate a new skb extensions storage + * + * @flags: See kmalloc(). + * + * Returns the newly allocated pointer. The pointer can later attached to a + * skb via __skb_ext_set(). + * Note: caller must handle the skb_ext as an opaque data. + */ +struct skb_ext *__skb_ext_alloc(gfp_t flags) { - struct skb_ext *new = kmem_cache_alloc(skbuff_ext_cache, GFP_ATOMIC); + struct skb_ext *new = kmem_cache_alloc(skbuff_ext_cache, flags); if (new) { memset(new->offset, 0, sizeof(new->offset)); @@ -5631,11 +7054,44 @@ static struct skb_ext *skb_ext_maybe_cow(struct skb_ext *old, xfrm_state_hold(sp->xvec[i]); } #endif +#ifdef CONFIG_MCTP_FLOWS + if (old_active & (1 << SKB_EXT_MCTP)) { + struct mctp_flow *flow = skb_ext_get_ptr(old, SKB_EXT_MCTP); + + if (flow->key) + refcount_inc(&flow->key->refs); + } +#endif __skb_ext_put(old); return new; } /** + * __skb_ext_set - attach the specified extension storage to this skb + * @skb: buffer + * @id: extension id + * @ext: extension storage previously allocated via __skb_ext_alloc() + * + * Existing extensions, if any, are cleared. + * + * Returns the pointer to the extension. + */ +void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, + struct skb_ext *ext) +{ + unsigned int newlen, newoff = SKB_EXT_CHUNKSIZEOF(*ext); + + skb_ext_put(skb); + newlen = newoff + skb_ext_type_len[id]; + ext->chunks = newlen; + ext->offset[id] = newoff; + skb->extensions = ext; + skb->active_extensions = 1 << id; + return skb_ext_get_ptr(ext, id); +} +EXPORT_SYMBOL_NS_GPL(__skb_ext_set, "NETDEV_INTERNAL"); + +/** * skb_ext_add - allocate space for given extension, COW if needed * @skb: buffer * @id: extension to allocate space for @@ -5668,7 +7124,7 @@ void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id) } else { newoff = SKB_EXT_CHUNKSIZEOF(*new); - new = skb_ext_alloc(); + new = __skb_ext_alloc(GFP_ATOMIC); if (!new) return NULL; } @@ -5677,6 +7133,7 @@ void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id) new->chunks = newlen; new->offset[id] = newoff; set_active: + skb->slow_gro = 1; skb->extensions = new; skb->active_extensions |= 1 << id; return skb_ext_get_ptr(new, id); @@ -5693,6 +7150,14 @@ static void skb_ext_put_sp(struct sec_path *sp) } #endif +#ifdef CONFIG_MCTP_FLOWS +static void skb_ext_put_mctp(struct mctp_flow *flow) +{ + if (flow->key) + mctp_key_unref(flow->key); +} +#endif + void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id) { struct skb_ext *ext = skb->extensions; @@ -5728,8 +7193,227 @@ free_now: if (__skb_ext_exist(ext, SKB_EXT_SEC_PATH)) skb_ext_put_sp(skb_ext_get_ptr(ext, SKB_EXT_SEC_PATH)); #endif +#ifdef CONFIG_MCTP_FLOWS + if (__skb_ext_exist(ext, SKB_EXT_MCTP)) + skb_ext_put_mctp(skb_ext_get_ptr(ext, SKB_EXT_MCTP)); +#endif kmem_cache_free(skbuff_ext_cache, ext); } EXPORT_SYMBOL(__skb_ext_put); #endif /* CONFIG_SKB_EXTENSIONS */ + +static void kfree_skb_napi_cache(struct sk_buff *skb) +{ + /* if SKB is a clone, don't handle this case */ + if (skb->fclone != SKB_FCLONE_UNAVAILABLE) { + __kfree_skb(skb); + return; + } + + local_bh_disable(); + __napi_kfree_skb(skb, SKB_CONSUMED); + local_bh_enable(); +} + +/** + * skb_attempt_defer_free - queue skb for remote freeing + * @skb: buffer + * + * Put @skb in a per-cpu list, using the cpu which + * allocated the skb/pages to reduce false sharing + * and memory zone spinlock contention. + */ +void skb_attempt_defer_free(struct sk_buff *skb) +{ + struct skb_defer_node *sdn; + unsigned long defer_count; + int cpu = skb->alloc_cpu; + unsigned int defer_max; + bool kick; + + if (cpu == raw_smp_processor_id() || + WARN_ON_ONCE(cpu >= nr_cpu_ids) || + !cpu_online(cpu)) { +nodefer: kfree_skb_napi_cache(skb); + return; + } + + DEBUG_NET_WARN_ON_ONCE(skb_dst(skb)); + DEBUG_NET_WARN_ON_ONCE(skb->destructor); + DEBUG_NET_WARN_ON_ONCE(skb_nfct(skb)); + + sdn = per_cpu_ptr(net_hotdata.skb_defer_nodes, cpu) + numa_node_id(); + + defer_max = READ_ONCE(net_hotdata.sysctl_skb_defer_max); + defer_count = atomic_long_inc_return(&sdn->defer_count); + + if (defer_count >= defer_max) + goto nodefer; + + llist_add(&skb->ll_node, &sdn->defer_list); + + /* Send an IPI every time queue reaches half capacity. */ + kick = (defer_count - 1) == (defer_max >> 1); + + /* Make sure to trigger NET_RX_SOFTIRQ on the remote CPU + * if we are unlucky enough (this seems very unlikely). + */ + if (unlikely(kick)) + kick_defer_list_purge(cpu); +} + +static void skb_splice_csum_page(struct sk_buff *skb, struct page *page, + size_t offset, size_t len) +{ + const char *kaddr; + __wsum csum; + + kaddr = kmap_local_page(page); + csum = csum_partial(kaddr + offset, len, 0); + kunmap_local(kaddr); + skb->csum = csum_block_add(skb->csum, csum, skb->len); +} + +/** + * skb_splice_from_iter - Splice (or copy) pages to skbuff + * @skb: The buffer to add pages to + * @iter: Iterator representing the pages to be added + * @maxsize: Maximum amount of pages to be added + * + * This is a common helper function for supporting MSG_SPLICE_PAGES. It + * extracts pages from an iterator and adds them to the socket buffer if + * possible, copying them to fragments if not possible (such as if they're slab + * pages). + * + * Returns the amount of data spliced/copied or -EMSGSIZE if there's + * insufficient space in the buffer to transfer anything. + */ +ssize_t skb_splice_from_iter(struct sk_buff *skb, struct iov_iter *iter, + ssize_t maxsize) +{ + size_t frag_limit = READ_ONCE(net_hotdata.sysctl_max_skb_frags); + struct page *pages[8], **ppages = pages; + ssize_t spliced = 0, ret = 0; + unsigned int i; + + while (iter->count > 0) { + ssize_t space, nr, len; + size_t off; + + ret = -EMSGSIZE; + space = frag_limit - skb_shinfo(skb)->nr_frags; + if (space < 0) + break; + + /* We might be able to coalesce without increasing nr_frags */ + nr = clamp_t(size_t, space, 1, ARRAY_SIZE(pages)); + + len = iov_iter_extract_pages(iter, &ppages, maxsize, nr, 0, &off); + if (len <= 0) { + ret = len ?: -EIO; + break; + } + + i = 0; + do { + struct page *page = pages[i++]; + size_t part = min_t(size_t, PAGE_SIZE - off, len); + + ret = -EIO; + if (WARN_ON_ONCE(!sendpage_ok(page))) + goto out; + + ret = skb_append_pagefrags(skb, page, off, part, + frag_limit); + if (ret < 0) { + iov_iter_revert(iter, len); + goto out; + } + + if (skb->ip_summed == CHECKSUM_NONE) + skb_splice_csum_page(skb, page, off, part); + + off = 0; + spliced += part; + maxsize -= part; + len -= part; + } while (len > 0); + + if (maxsize <= 0) + break; + } + +out: + skb_len_add(skb, spliced); + return spliced ?: ret; +} +EXPORT_SYMBOL(skb_splice_from_iter); + +static __always_inline +size_t memcpy_from_iter_csum(void *iter_from, size_t progress, + size_t len, void *to, void *priv2) +{ + __wsum *csum = priv2; + __wsum next = csum_partial_copy_nocheck(iter_from, to + progress, len); + + *csum = csum_block_add(*csum, next, progress); + return 0; +} + +static __always_inline +size_t copy_from_user_iter_csum(void __user *iter_from, size_t progress, + size_t len, void *to, void *priv2) +{ + __wsum next, *csum = priv2; + + next = csum_and_copy_from_user(iter_from, to + progress, len); + *csum = csum_block_add(*csum, next, progress); + return next ? 0 : len; +} + +bool csum_and_copy_from_iter_full(void *addr, size_t bytes, + __wsum *csum, struct iov_iter *i) +{ + size_t copied; + + if (WARN_ON_ONCE(!i->data_source)) + return false; + copied = iterate_and_advance2(i, bytes, addr, csum, + copy_from_user_iter_csum, + memcpy_from_iter_csum); + if (likely(copied == bytes)) + return true; + iov_iter_revert(i, copied); + return false; +} +EXPORT_SYMBOL(csum_and_copy_from_iter_full); + +void get_netmem(netmem_ref netmem) +{ + struct net_iov *niov; + + if (netmem_is_net_iov(netmem)) { + niov = netmem_to_net_iov(netmem); + if (net_is_devmem_iov(niov)) + net_devmem_get_net_iov(netmem_to_net_iov(netmem)); + return; + } + get_page(netmem_to_page(netmem)); +} +EXPORT_SYMBOL(get_netmem); + +void put_netmem(netmem_ref netmem) +{ + struct net_iov *niov; + + if (netmem_is_net_iov(netmem)) { + niov = netmem_to_net_iov(netmem); + if (net_is_devmem_iov(niov)) + net_devmem_put_net_iov(netmem_to_net_iov(netmem)); + return; + } + + put_page(netmem_to_page(netmem)); +} +EXPORT_SYMBOL(put_netmem); |