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2018-01-30Merge tag 'nfs-for-4.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Highlights include: Stable bugfixes: - Fix breakages in the nfsstat utility due to the inclusion of the NFSv4 LOOKUPP operation - Fix a NULL pointer dereference in nfs_idmap_prepare_pipe_upcall() due to nfs_idmap_legacy_upcall() being called without an 'aux' parameter - Fix a refcount leak in the standard O_DIRECT error path - Fix a refcount leak in the pNFS O_DIRECT fallback to MDS path - Fix CPU latency issues with nfs_commit_release_pages() - Fix the LAYOUTUNAVAILABLE error case in the file layout type - NFS: Fix a race between mmap() and O_DIRECT Features: - Support the statx() mask and query flags to enable optimisations when the user is requesting only attributes that are already up to date in the inode cache, or is specifying the AT_STATX_DONT_SYNC flag - Add a module alias for the SCSI pNFS layout type Bugfixes: - Automounting when resolving a NFSv4 referral should preserve the RDMA transport protocol settings - Various other RDMA bugfixes from Chuck - pNFS block layout fixes - Always set NFS_LOCK_LOST when a lock is lost" * tag 'nfs-for-4.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (69 commits) NFS: Fix a race between mmap() and O_DIRECT NFS: Remove a redundant call to unmap_mapping_range() pnfs/blocklayout: Ensure disk address in block device map pnfs/blocklayout: pnfs_block_dev_map uses bytes, not sectors lockd: Fix server refcounting SUNRPC: Fix null rpc_clnt dereference in rpc_task_queued tracepoint SUNRPC: Micro-optimize __rpc_execute SUNRPC: task_run_action should display tk_callback sunrpc: Format RPC events consistently for display SUNRPC: Trace xprt_timer events xprtrdma: Correct some documenting comments xprtrdma: Fix "bytes registered" accounting xprtrdma: Instrument allocation/release of rpcrdma_req/rep objects xprtrdma: Add trace points to instrument QP and CQ access upcalls xprtrdma: Add trace points in the client-side backchannel code paths xprtrdma: Add trace points for connect events xprtrdma: Add trace points to instrument MR allocation and recovery xprtrdma: Add trace points to instrument memory invalidation xprtrdma: Add trace points in reply decoder path xprtrdma: Add trace points to instrument memory registration ..
2018-01-30Merge branch 'work.sock_recvmsg' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull kern_recvmsg reduction from Al Viro: "kernel_recvmsg() is a set_fs()-using wrapper for sock_recvmsg(). In all but one case that is not needed - use of ITER_KVEC for ->msg_iter takes care of the data and does not care about set_fs(). The only exception is svc_udp_recvfrom() where we want cmsg to be store into kernel object; everything else can just use sock_recvmsg() and be done with that. A followup converting svc_udp_recvfrom() away from set_fs() (and killing kernel_recvmsg() off) is *NOT* in here - I'd like to hear what netdev folks think of the approach proposed in that followup)" * 'work.sock_recvmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: tipc: switch to sock_recvmsg() smc: switch to sock_recvmsg() ipvs: switch to sock_recvmsg() mISDN: switch to sock_recvmsg() drbd: switch to sock_recvmsg() lustre lnet_sock_read(): switch to sock_recvmsg() cfs2: switch to sock_recvmsg() ncpfs: switch to sock_recvmsg() dlm: switch to sock_recvmsg() svc_recvfrom(): switch to sock_recvmsg()
2018-01-30Merge branch 'misc.poll' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull poll annotations from Al Viro: "This introduces a __bitwise type for POLL### bitmap, and propagates the annotations through the tree. Most of that stuff is as simple as 'make ->poll() instances return __poll_t and do the same to local variables used to hold the future return value'. Some of the obvious brainos found in process are fixed (e.g. POLLIN misspelled as POLL_IN). At that point the amount of sparse warnings is low and most of them are for genuine bugs - e.g. ->poll() instance deciding to return -EINVAL instead of a bitmap. I hadn't touched those in this series - it's large enough as it is. Another problem it has caught was eventpoll() ABI mess; select.c and eventpoll.c assumed that corresponding POLL### and EPOLL### were equal. That's true for some, but not all of them - EPOLL### are arch-independent, but POLL### are not. The last commit in this series separates userland POLL### values from the (now arch-independent) kernel-side ones, converting between them in the few places where they are copied to/from userland. AFAICS, this is the least disruptive fix preserving poll(2) ABI and making epoll() work on all architectures. As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and it will trigger only on what would've triggered EPOLLWRBAND on other architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered at all on sparc. With this patch they should work consistently on all architectures" * 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits) make kernel-side POLL... arch-independent eventpoll: no need to mask the result of epi_item_poll() again eventpoll: constify struct epoll_event pointers debugging printk in sg_poll() uses %x to print POLL... bitmap annotate poll(2) guts 9p: untangle ->poll() mess ->si_band gets POLL... bitmap stored into a user-visible long field ring_buffer_poll_wait() return value used as return value of ->poll() the rest of drivers/*: annotate ->poll() instances media: annotate ->poll() instances fs: annotate ->poll() instances ipc, kernel, mm: annotate ->poll() instances net: annotate ->poll() instances apparmor: annotate ->poll() instances tomoyo: annotate ->poll() instances sound: annotate ->poll() instances acpi: annotate ->poll() instances crypto: annotate ->poll() instances block: annotate ->poll() instances x86: annotate ->poll() instances ...
2018-01-30nl80211: Sanitize array index in parse_txq_paramsDan Williams
Wireless drivers rely on parse_txq_params to validate that txq_params->ac is less than NL80211_NUM_ACS by the time the low-level driver's ->conf_tx() handler is called. Use a new helper, array_index_nospec(), to sanitize txq_params->ac with respect to speculation. I.e. ensure that any speculation into ->conf_tx() handlers is done with a value of txq_params->ac that is within the bounds of [0, NL80211_NUM_ACS). Reported-by: Christian Lamparter <chunkeey@gmail.com> Reported-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Johannes Berg <johannes@sipsolutions.net> Cc: linux-arch@vger.kernel.org Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: linux-wireless@vger.kernel.org Cc: torvalds@linux-foundation.org Cc: "David S. Miller" <davem@davemloft.net> Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727419584.33451.7700736761686184303.stgit@dwillia2-desk3.amr.corp.intel.com
2018-01-30Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main RCU changes in this cycle were: - Updates to use cond_resched() instead of cond_resched_rcu_qs() where feasible (currently everywhere except in kernel/rcu and in kernel/torture.c). Also a couple of fixes to avoid sending IPIs to offline CPUs. - Updates to simplify RCU's dyntick-idle handling. - Updates to remove almost all uses of smp_read_barrier_depends() and read_barrier_depends(). - Torture-test updates. - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) torture: Save a line in stutter_wait(): while -> for torture: Eliminate torture_runnable and perf_runnable torture: Make stutter less vulnerable to compilers and races locking/locktorture: Fix num reader/writer corner cases locking/locktorture: Fix rwsem reader_delay torture: Place all torture-test modules in one MAINTAINERS group rcutorture/kvm-build.sh: Skip build directory check rcutorture: Simplify functions.sh include path rcutorture: Simplify logging rcutorture/kvm-recheck-*: Improve result directory readability check rcutorture/kvm.sh: Support execution from any directory rcutorture/kvm.sh: Use consistent help text for --qemu-args rcutorture/kvm.sh: Remove unused variable, `alldone` rcutorture: Remove unused script, config2frag.sh rcutorture/configinit: Fix build directory error message rcutorture: Preempt RCU-preempt readers more vigorously torture: Reduce #ifdefs for preempt_schedule() rcu: Remove have_rcu_nocb_mask from tree_plugin.h rcu: Add comment giving debug strategy for double call_rcu() tracing, rcu: Hide trace event rcu_nocb_wake when not used ...
2018-01-30Merge tag v4.15 of ↵Jason Gunthorpe
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git To resolve conflicts in: drivers/infiniband/hw/mlx5/main.c drivers/infiniband/hw/mlx5/qp.c From patches merged into the -rc cycle. The conflict resolution matches what linux-next has been carrying. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-01-30ipmr: Fix ptrdiff_t print formattingJames Hogan
ipmr_vif_seq_show() prints the difference between two pointers with the format string %2zd (z for size_t), however the correct format string is %2td instead (t for ptrdiff_t). The same bug in ip6mr_vif_seq_show() was already fixed long ago by commit d430a227d272 ("bogus format in ip6mr"). Signed-off-by: James Hogan <jhogan@kernel.org> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: "David S. Miller" <davem@davemloft.net> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29tcp: release sk_frag.page in tcp_disconnectLi RongQing
socket can be disconnected and gets transformed back to a listening socket, if sk_frag.page is not released, which will be cloned into a new socket by sk_clone_lock, but the reference count of this page is increased, lead to a use after free or double free issue Signed-off-by: Li RongQing <lirongqing@baidu.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29ipv4: Get the address of interface correctly.Tonghao Zhang
When using ioctl to get address of interface, we can't get it anymore. For example, the command is show as below. # ifconfig eth0 In the patch ("03aef17bb79b3"), the devinet_ioctl does not return a suitable value, even though we can find it in the kernel. Then fix it now. Fixes: 03aef17bb79b3 ("devinet_ioctl(): take copyin/copyout to caller") Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29net_sched: gen_estimator: fix lockdep splatEric Dumazet
syzbot reported a lockdep splat in gen_new_estimator() / est_fetch_counters() when attempting to lock est->stats_lock. Since est_fetch_counters() is called from BH context from timer interrupt, we need to block BH as well when calling it from process context. Most qdiscs use per cpu counters and are immune to the problem, but net/sched/act_api.c and net/netfilter/xt_RATEEST.c are using a spinlock to protect their data. They both call gen_new_estimator() while object is created and not yet alive, so this bug could not trigger a deadlock, only a lockdep splat. Fixes: 1c0d32fde5bd ("net_sched: gen_estimator: complete rewrite of rate estimators") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29ipv6: addrconf: break critical section in addrconf_verify_rtnl()Eric Dumazet
Heiner reported a lockdep splat [1] This is caused by attempting GFP_KERNEL allocation while RCU lock is held and BH blocked. We believe that addrconf_verify_rtnl() could run for a long period, so instead of using GFP_ATOMIC here as Ido suggested, we should break the critical section and restart it after the allocation. [1] [86220.125562] ============================= [86220.125586] WARNING: suspicious RCU usage [86220.125612] 4.15.0-rc7-next-20180110+ #7 Not tainted [86220.125641] ----------------------------- [86220.125666] kernel/sched/core.c:6026 Illegal context switch in RCU-bh read-side critical section! [86220.125711] other info that might help us debug this: [86220.125755] rcu_scheduler_active = 2, debug_locks = 1 [86220.125792] 4 locks held by kworker/0:2/1003: [86220.125817] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680 [86220.125895] #1: ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680 [86220.125959] #2: (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20 [86220.126017] #3: (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6] [86220.126111] stack backtrace: [86220.126142] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7 [86220.126185] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015 [86220.126250] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6] [86220.126288] Call Trace: [86220.126312] dump_stack+0x70/0x9e [86220.126337] lockdep_rcu_suspicious+0xce/0xf0 [86220.126365] ___might_sleep+0x1d3/0x240 [86220.126390] __might_sleep+0x45/0x80 [86220.126416] kmem_cache_alloc_trace+0x53/0x250 [86220.126458] ? ipv6_add_addr+0xfe/0x6e0 [ipv6] [86220.126498] ipv6_add_addr+0xfe/0x6e0 [ipv6] [86220.126538] ipv6_create_tempaddr+0x24d/0x430 [ipv6] [86220.126580] ? ipv6_create_tempaddr+0x24d/0x430 [ipv6] [86220.126623] addrconf_verify_rtnl+0x339/0x510 [ipv6] [86220.126664] ? addrconf_verify_rtnl+0x339/0x510 [ipv6] [86220.126708] addrconf_verify_work+0xe/0x20 [ipv6] [86220.126738] process_one_work+0x258/0x680 [86220.126765] worker_thread+0x35/0x3f0 [86220.126790] kthread+0x124/0x140 [86220.126813] ? process_one_work+0x680/0x680 [86220.126839] ? kthread_create_worker_on_cpu+0x40/0x40 [86220.126869] ? umh_complete+0x40/0x40 [86220.126893] ? call_usermodehelper_exec_async+0x12a/0x160 [86220.126926] ret_from_fork+0x4b/0x60 [86220.126999] BUG: sleeping function called from invalid context at mm/slab.h:420 [86220.127041] in_atomic(): 1, irqs_disabled(): 0, pid: 1003, name: kworker/0:2 [86220.127082] 4 locks held by kworker/0:2/1003: [86220.127107] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680 [86220.127179] #1: ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680 [86220.127242] #2: (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20 [86220.127300] #3: (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6] [86220.127414] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7 [86220.127463] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015 [86220.127528] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6] [86220.127568] Call Trace: [86220.127591] dump_stack+0x70/0x9e [86220.127616] ___might_sleep+0x14d/0x240 [86220.127644] __might_sleep+0x45/0x80 [86220.127672] kmem_cache_alloc_trace+0x53/0x250 [86220.127717] ? ipv6_add_addr+0xfe/0x6e0 [ipv6] [86220.127762] ipv6_add_addr+0xfe/0x6e0 [ipv6] [86220.127807] ipv6_create_tempaddr+0x24d/0x430 [ipv6] [86220.127854] ? ipv6_create_tempaddr+0x24d/0x430 [ipv6] [86220.127903] addrconf_verify_rtnl+0x339/0x510 [ipv6] [86220.127950] ? addrconf_verify_rtnl+0x339/0x510 [ipv6] [86220.127998] addrconf_verify_work+0xe/0x20 [ipv6] [86220.128032] process_one_work+0x258/0x680 [86220.128063] worker_thread+0x35/0x3f0 [86220.128091] kthread+0x124/0x140 [86220.128117] ? process_one_work+0x680/0x680 [86220.128146] ? kthread_create_worker_on_cpu+0x40/0x40 [86220.128180] ? umh_complete+0x40/0x40 [86220.128207] ? call_usermodehelper_exec_async+0x12a/0x160 [86220.128243] ret_from_fork+0x4b/0x60 Fixes: f3d9832e56c4 ("ipv6: addrconf: cleanup locking in ipv6_add_addr") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29ipv6: change route cache aging logicWei Wang
In current route cache aging logic, if a route has both RTF_EXPIRE and RTF_GATEWAY set, the route will only be removed if the neighbor cache has no NTF_ROUTER flag. Otherwise, even if the route has expired, it won't get deleted. Fix this logic to always check if the route has expired first and then do the gateway neighbor cache check if previous check decide to not remove the exception entry. Fixes: 1859bac04fb6 ("ipv6: remove from fib tree aged out RTF_CACHE dst") Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29net: ipv6: send unsolicited NA after DADDavid Ahern
Unsolicited IPv6 neighbor advertisements should be sent after DAD completes. Update ndisc_send_unsol_na to skip tentative, non-optimistic addresses and have those sent by addrconf_dad_completed after DAD. Fixes: 4a6e3c5def13c ("net: ipv6: send unsolicited NA on admin up") Reported-by: Vivek Venkatraman <vivek@cumulusnetworks.com> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29net_sched: implement ->change_tx_queue_len() for pfifo_fastCong Wang
pfifo_fast used to drop based on qdisc_dev(qdisc)->tx_queue_len, so we have to resize skb array when we change tx_queue_len. Other qdiscs which read tx_queue_len are fine because they all save it to sch->limit or somewhere else in qdisc during init. They don't have to implement this, it is nicer if they do so that users don't have to re-configure qdisc after changing tx_queue_len. Cc: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29net_sched: plug in qdisc ops change_tx_queue_lenCong Wang
Introduce a new qdisc ops ->change_tx_queue_len() so that each qdisc could decide how to implement this if it wants. Previously we simply read dev->tx_queue_len, after pfifo_fast switches to skb array, we need this API to resize the skb array when we change dev->tx_queue_len. To avoid handling race conditions with TX BH, we need to deactivate all TX queues before change the value and bring them back after we are done, this also makes implementation easier. Cc: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29net: introduce helper dev_change_tx_queue_len()Cong Wang
This patch promotes the local change_tx_queue_len() to a core helper function, dev_change_tx_queue_len(), so that rtnetlink and net-sysfs could share the code. This also prepares for the following patch. Note, the -EFAULT in the original code doesn't make sense, we should propagate the errno from notifiers. Cc: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29libceph: check kstrndup() return valueChengguang Xu
Should check result of kstrndup() in case of memory allocation failure. Signed-off-by: Chengguang Xu <cgxu519@icloud.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2018-01-29dev: advertise the new ifindex when the netns iface changesNicolas Dichtel
The goal is to let the user follow an interface that moves to another netns. CC: Jiri Benc <jbenc@redhat.com> CC: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29dev: always advertise the new nsid when the netns iface changesNicolas Dichtel
The user should be able to follow any interface that moves to another netns. There is no reason to hide physical interfaces. CC: Jiri Benc <jbenc@redhat.com> CC: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29ipv6: Fix SO_REUSEPORT UDP socket with implicit sk_ipv6onlyMartin KaFai Lau
If a sk_v6_rcv_saddr is !IPV6_ADDR_ANY and !IPV6_ADDR_MAPPED, it implicitly implies it is an ipv6only socket. However, in inet6_bind(), this addr_type checking and setting sk->sk_ipv6only to 1 are only done after sk->sk_prot->get_port(sk, snum) has been completed successfully. This inconsistency between sk_v6_rcv_saddr and sk_ipv6only confuses the 'get_port()'. In particular, when binding SO_REUSEPORT UDP sockets, udp_reuseport_add_sock(sk,...) is called. udp_reuseport_add_sock() checks "ipv6_only_sock(sk2) == ipv6_only_sock(sk)" before adding sk to sk2->sk_reuseport_cb. In this case, ipv6_only_sock(sk2) could be 1 while ipv6_only_sock(sk) is still 0 here. The end result is, reuseport_alloc(sk) is called instead of adding sk to the existing sk2->sk_reuseport_cb. It can be reproduced by binding two SO_REUSEPORT UDP sockets on an IPv6 address (!ANY and !MAPPED). Only one of the socket will receive packet. The fix is to set the implicit sk_ipv6only before calling get_port(). The original sk_ipv6only has to be saved such that it can be restored in case get_port() failed. The situation is similar to the inet_reset_saddr(sk) after get_port() has failed. Thanks to Calvin Owens <calvinowens@fb.com> who created an easy reproduction which leads to a fix. Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29rtnetlink: enable IFLA_IF_NETNSID for RTM_DELLINKChristian Brauner
- Backwards Compatibility: If userspace wants to determine whether RTM_DELLINK supports the IFLA_IF_NETNSID property they should first send an RTM_GETLINK request with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply does not include IFLA_IF_NETNSID userspace should assume that IFLA_IF_NETNSID is not supported on this kernel. If the reply does contain an IFLA_IF_NETNSID property userspace can send an RTM_DELLINK with a IFLA_IF_NETNSID property. If they receive EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property with RTM_DELLINK. Userpace should then fallback to other means. - Security: Callers must have CAP_NET_ADMIN in the owning user namespace of the target network namespace. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29rtnetlink: enable IFLA_IF_NETNSID for RTM_SETLINKChristian Brauner
- Backwards Compatibility: If userspace wants to determine whether RTM_SETLINK supports the IFLA_IF_NETNSID property they should first send an RTM_GETLINK request with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply does not include IFLA_IF_NETNSID userspace should assume that IFLA_IF_NETNSID is not supported on this kernel. If the reply does contain an IFLA_IF_NETNSID property userspace can send an RTM_SETLINK with a IFLA_IF_NETNSID property. If they receive EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property with RTM_SETLINK. Userpace should then fallback to other means. To retain backwards compatibility the kernel will first check whether a IFLA_NET_NS_PID or IFLA_NET_NS_FD property has been passed. If either one is found it will be used to identify the target network namespace. This implies that users who do not care whether their running kernel supports IFLA_IF_NETNSID with RTM_SETLINK can pass both IFLA_NET_NS_{FD,PID} and IFLA_IF_NETNSID referring to the same network namespace. - Security: Callers must have CAP_NET_ADMIN in the owning user namespace of the target network namespace. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29rtnetlink: enable IFLA_IF_NETNSID in do_setlink()Christian Brauner
RTM_{NEW,SET}LINK already allow operations on other network namespaces by identifying the target network namespace through IFLA_NET_NS_{FD,PID} properties. This is done by looking for the corresponding properties in do_setlink(). Extend do_setlink() to also look for the IFLA_IF_NETNSID property. This introduces no functional changes since all callers of do_setlink() currently block IFLA_IF_NETNSID by reporting an error before they reach do_setlink(). This introduces the helpers: static struct net *rtnl_link_get_net_by_nlattr(struct net *src_net, struct nlattr *tb[]) static struct net *rtnl_link_get_net_capable(const struct sk_buff *skb, struct net *src_net, struct nlattr *tb[], int cap) to simplify permission checks and target network namespace retrieval for RTM_* requests that already support IFLA_NET_NS_{FD,PID} but get extended to IFLA_IF_NETNSID. To perserve backwards compatibility the helpers look for IFLA_NET_NS_{FD,PID} properties first before checking for IFLA_IF_NETNSID. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2018-01-26 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) A number of extensions to tcp-bpf, from Lawrence. - direct R or R/W access to many tcp_sock fields via bpf_sock_ops - passing up to 3 arguments to bpf_sock_ops functions - tcp_sock field bpf_sock_ops_cb_flags for controlling callbacks - optionally calling bpf_sock_ops program when RTO fires - optionally calling bpf_sock_ops program when packet is retransmitted - optionally calling bpf_sock_ops program when TCP state changes - access to tclass and sk_txhash - new selftest 2) div/mod exception handling, from Daniel. One of the ugly leftovers from the early eBPF days is that div/mod operations based on registers have a hard-coded src_reg == 0 test in the interpreter as well as in JIT code generators that would return from the BPF program with exit code 0. This was basically adopted from cBPF interpreter for historical reasons. There are multiple reasons why this is very suboptimal and prone to bugs. To name one: the return code mapping for such abnormal program exit of 0 does not always match with a suitable program type's exit code mapping. For example, '0' in tc means action 'ok' where the packet gets passed further up the stack, which is just undesirable for such cases (e.g. when implementing policy) and also does not match with other program types. After considering _four_ different ways to address the problem, we adapt the same behavior as on some major archs like ARMv8: X div 0 results in 0, and X mod 0 results in X. aarch64 and aarch32 ISA do not generate any traps or otherwise aborts of program execution for unsigned divides. Given the options, it seems the most suitable from all of them, also since major archs have similar schemes in place. Given this is all in the realm of undefined behavior, we still have the option to adapt if deemed necessary. 3) sockmap sample refactoring, from John. 4) lpm map get_next_key fixes, from Yonghong. 5) test cleanups, from Alexei and Prashant. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26bpf: fix subprog verifier bypass by div/mod by 0 exceptionDaniel Borkmann
One of the ugly leftovers from the early eBPF days is that div/mod operations based on registers have a hard-coded src_reg == 0 test in the interpreter as well as in JIT code generators that would return from the BPF program with exit code 0. This was basically adopted from cBPF interpreter for historical reasons. There are multiple reasons why this is very suboptimal and prone to bugs. To name one: the return code mapping for such abnormal program exit of 0 does not always match with a suitable program type's exit code mapping. For example, '0' in tc means action 'ok' where the packet gets passed further up the stack, which is just undesirable for such cases (e.g. when implementing policy) and also does not match with other program types. While trying to work out an exception handling scheme, I also noticed that programs crafted like the following will currently pass the verifier: 0: (bf) r6 = r1 1: (85) call pc+8 caller: R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1 callee: frame1: R1=ctx(id=0,off=0,imm=0) R10=fp0,call_1 10: (b4) (u32) r2 = (u32) 0 11: (b4) (u32) r3 = (u32) 1 12: (3c) (u32) r3 /= (u32) r2 13: (61) r0 = *(u32 *)(r1 +76) 14: (95) exit returning from callee: frame1: R0_w=pkt(id=0,off=0,r=0,imm=0) R1=ctx(id=0,off=0,imm=0) R2_w=inv0 R3_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0,call_1 to caller at 2: R0_w=pkt(id=0,off=0,r=0,imm=0) R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1 from 14 to 2: R0=pkt(id=0,off=0,r=0,imm=0) R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1 2: (bf) r1 = r6 3: (61) r1 = *(u32 *)(r1 +80) 4: (bf) r2 = r0 5: (07) r2 += 8 6: (2d) if r2 > r1 goto pc+1 R0=pkt(id=0,off=0,r=8,imm=0) R1=pkt_end(id=0,off=0,imm=0) R2=pkt(id=0,off=8,r=8,imm=0) R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1 7: (71) r0 = *(u8 *)(r0 +0) 8: (b7) r0 = 1 9: (95) exit from 6 to 8: safe processed 16 insns (limit 131072), stack depth 0+0 Basically what happens is that in the subprog we make use of a div/mod by 0 exception and in the 'normal' subprog's exit path we just return skb->data back to the main prog. This has the implication that the verifier thinks we always get a pkt pointer in R0 while we still have the implicit 'return 0' from the div as an alternative unconditional return path earlier. Thus, R0 then contains 0, meaning back in the parent prog we get the address range of [0x0, skb->data_end] as read and writeable. Similar can be crafted with other pointer register types. Since i) BPF_ABS/IND is not allowed in programs that contain BPF to BPF calls (and generally it's also disadvised to use in native eBPF context), ii) unknown opcodes don't return zero anymore, iii) we don't return an exception code in dead branches, the only last missing case affected and to fix is the div/mod handling. What we would really need is some infrastructure to propagate exceptions all the way to the original prog unwinding the current stack and returning that code to the caller of the BPF program. In user space such exception handling for similar runtimes is typically implemented with setjmp(3) and longjmp(3) as one possibility which is not available in the kernel, though (kgdb used to implement it in kernel long time ago). I implemented a PoC exception handling mechanism into the BPF interpreter with porting setjmp()/longjmp() into x86_64 and adding a new internal BPF_ABRT opcode that can use a program specific exception code for all exception cases we have (e.g. div/mod by 0, unknown opcodes, etc). While this seems to work in the constrained BPF environment (meaning, here, we don't need to deal with state e.g. from memory allocations that we would need to undo before going into exception state), it still has various drawbacks: i) we would need to implement the setjmp()/longjmp() for every arch supported in the kernel and for x86_64, arm64, sparc64 JITs currently supporting calls, ii) it has unconditional additional cost on main program entry to store CPU register state in initial setjmp() call, and we would need some way to pass the jmp_buf down into ___bpf_prog_run() for main prog and all subprogs, but also storing on stack is not really nice (other option would be per-cpu storage for this, but it also has the drawback that we need to disable preemption for every BPF program types). All in all this approach would add a lot of complexity. Another poor-man's solution would be to have some sort of additional shared register or scratch buffer to hold state for exceptions, and test that after every call return to chain returns and pass R0 all the way down to BPF prog caller. This is also problematic in various ways: i) an additional register doesn't map well into JITs, and some other scratch space could only be on per-cpu storage, which, again has the side-effect that this only works when we disable preemption, or somewhere in the input context which is not available everywhere either, and ii) this adds significant runtime overhead by putting conditionals after each and every call, as well as implementation complexity. Yet another option is to teach verifier that div/mod can return an integer, which however is also complex to implement as verifier would need to walk such fake 'mov r0,<code>; exit;' sequeuence and there would still be no guarantee for having propagation of this further down to the BPF caller as proper exception code. For parent prog, it is also is not distinguishable from a normal return of a constant scalar value. The approach taken here is a completely different one with little complexity and no additional overhead involved in that we make use of the fact that a div/mod by 0 is undefined behavior. Instead of bailing out, we adapt the same behavior as on some major archs like ARMv8 [0] into eBPF as well: X div 0 results in 0, and X mod 0 results in X. aarch64 and aarch32 ISA do not generate any traps or otherwise aborts of program execution for unsigned divides. I verified this also with a test program compiled by gcc and clang, and the behavior matches with the spec. Going forward we adapt the eBPF verifier to emit such rewrites once div/mod by register was seen. cBPF is not touched and will keep existing 'return 0' semantics. Given the options, it seems the most suitable from all of them, also since major archs have similar schemes in place. Given this is all in the realm of undefined behavior, we still have the option to adapt if deemed necessary and this way we would also have the option of more flexibility from LLVM code generation side (which is then fully visible to verifier). Thus, this patch i) fixes the panic seen in above program and ii) doesn't bypass the verifier observations. [0] ARM Architecture Reference Manual, ARMv8 [ARM DDI 0487B.b] http://infocenter.arm.com/help/topic/com.arm.doc.ddi0487b.b/DDI0487B_b_armv8_arm.pdf 1) aarch64 instruction set: section C3.4.7 and C6.2.279 (UDIV) "A division by zero results in a zero being written to the destination register, without any indication that the division by zero occurred." 2) aarch32 instruction set: section F1.4.8 and F5.1.263 (UDIV) "For the SDIV and UDIV instructions, division by zero always returns a zero result." Fixes: f4d7e40a5b71 ("bpf: introduce function calls (verification)") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-26bpf: xor of a/x in cbpf can be done in 32 bit aluDaniel Borkmann
Very minor optimization; saves 1 byte per program in x86_64 JIT in cBPF prologue. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-26VSOCK: set POLLOUT | POLLWRNORM for TCP_CLOSINGStefan Hajnoczi
select(2) with wfds but no rfds must return when the socket is shut down by the peer. This way userspace notices socket activity and gets -EPIPE from the next write(2). Currently select(2) does not return for virtio-vsock when a SEND+RCV shutdown packet is received. This is because vsock_poll() only sets POLLOUT | POLLWRNORM for TCP_CLOSE, not the TCP_CLOSING state that the socket is in when the shutdown is received. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26dccp: don't restart ccid2_hc_tx_rto_expire() if sk in closed stateAlexey Kodanev
ccid2_hc_tx_rto_expire() timer callback always restarts the timer again and can run indefinitely (unless it is stopped outside), and after commit 120e9dabaf55 ("dccp: defer ccid_hc_tx_delete() at dismantle time"), which moved ccid_hc_tx_delete() (also includes sk_stop_timer()) from dccp_destroy_sock() to sk_destruct(), this started to happen quite often. The timer prevents releasing the socket, as a result, sk_destruct() won't be called. Found with LTP/dccp_ipsec tests running on the bonding device, which later couldn't be unloaded after the tests were completed: unregister_netdevice: waiting for bond0 to become free. Usage count = 148 Fixes: 2a91aa396739 ("[DCCP] CCID2: Initial CCID2 (TCP-Like) implementation") Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26Merge tag 'linux-can-next-for-4.16-20180126' of ↵David S. Miller
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next Marc Kleine-Budde says: ==================== pull-request: can-next 2018-01-26 this is a pull request for net-next/master consisting of 3 patches. The first two patches target the CAN documentation. The first is by me and fixes pointer to location of fsl,mpc5200-mscan node in the mpc5200 documentation. The second patch is by Robert Schwebel and it converts the plain ASCII documentation to restructured text. The third patch is by Fabrizio Castro add the r8a774[35] support to the rcar_can dt-bindings documentation. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26net/smc: return booleans instead of integersGustavo A. R. Silva
Return statements in functions returning bool should use true/false instead of 1/0. This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26net/smc: release clcsock from tcp_listen_workerUrsula Braun
Closing a listen socket may hit the warning WARN_ON(sock_owned_by_user(sk)) of tcp_close(), if the wake up of the smc_tcp_listen_worker has not yet finished. This patch introduces smc_close_wait_listen_clcsock() making sure the listening internal clcsock has been closed in smc_tcp_listen_work(), before the listening external SMC socket finishes closing. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26net/smc: replace sock_put worker by socket refcountingUrsula Braun
Proper socket refcounting makes the sock_put worker obsolete. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26net/smc: smc_poll improvementsUrsula Braun
Increase the socket refcount during poll wait. Take the socket lock before checking socket state. For a listening socket return a mask independent of state SMC_ACTIVE and cover errors or closed state as well. Get rid of the accept_q loop in smc_accept_poll(). Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26net/smc: handle device, port, and QP error eventsUrsula Braun
RoCE device changes cause an IB event, processed in the global event handler for the ROCE device. Problems for a certain Queue Pair cause a QP event, processed in the QP event handler for this QP. Among those events are port errors and other fatal device errors. All link groups using such a port or device must be terminated in those cases. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2018-01-26 One last patch for this development cycle: 1) Add ESN support for IPSec HW offload. From Yossef Efraim. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26net/ipv6: Add support for onlink flagDavid Ahern
Similar to IPv4 allow routes to be added with the RTNH_F_ONLINK flag. The onlink option requires a gateway and a nexthop device. Any unicast gateway is allowed (including IPv4 mapped addresses and unresolved ones) as long as the gateway is not a local address and if it resolves it must match the given device. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26net/ipv6: Add flags and table id to ip6_nh_lookup_tableDavid Ahern
onlink verification needs to do a lookup in potentially different table than the table in fib6_config and without the RT6_LOOKUP_F_IFACE flag. Change ip6_nh_lookup_table to take table id and flags as input arguments. Both verifications want to ignore link state, so add that flag can stay in the lookup helper. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26net/ipv6: Move gateway validation into helperDavid Ahern
Move existing code to validate nexthop into a helper. Follow on patch adds support for nexthops marked with onlink, and this helper keeps the complexity of ip6_route_info_create in check. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-26can: migrate documentation to restructured textRobert Schwebel
The kernel documentation is now restructured text. Convert the SocketCAN documentation and include it in the toplevel kernel documentation. This patch doesn't do any content change. All references to can.txt in the code are converted to can.rst. Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-01-25net/ipv4: Allow send to local broadcast from a socket bound to a VRFDavid Ahern
Message sends to the local broadcast address (255.255.255.255) require uc_index or sk_bound_dev_if to be set to an egress device. However, responses or only received if the socket is bound to the device. This is overly constraining for processes running in an L3 domain. This patch allows a socket bound to the VRF device to send to the local broadcast address by using IP_UNICAST_IF to set the egress interface with packet receipt handled by the VRF binding. Similar to IP_MULTICAST_IF, relax the constraint on setting IP_UNICAST_IF if a socket is bound to an L3 master device. In this case allow uc_index to be set to an enslaved if sk_bound_dev_if is an L3 master device and is the master device for the ifindex. In udp and raw sendmsg, allow uc_index to override the oif if uc_index master device is oif (ie., the oif is an L3 master and the index is an L3 slave). Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-25openvswitch: add erspan version I and II supportWilliam Tu
The patch adds support for openvswitch to configure erspan v1 and v2. The OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS attr is added to uapi as a binary blob to support all ERSPAN v1 and v2's fields. Note that Previous commit "openvswitch: Add erspan tunnel support." was reverted since it does not design properly. Signed-off-by: William Tu <u9012063@gmail.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-25net: erspan: use bitfield instead of mask and offsetWilliam Tu
Originally the erspan fields are defined as a group into a __be16 field, and use mask and offset to access each field. This is more costly due to calling ntohs/htons. The patch changes it to use bitfields. Signed-off-by: William Tu <u9012063@gmail.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-25bpf: Add BPF_SOCK_OPS_STATE_CBLawrence Brakmo
Adds support for calling sock_ops BPF program when there is a TCP state change. Two arguments are used; one for the old state and another for the new state. There is a new enum in include/uapi/linux/bpf.h that exports the TCP states that prepends BPF_ to the current TCP state names. If it is ever necessary to change the internal TCP state values (other than adding more to the end), then it will become necessary to convert from the internal TCP state value to the BPF value before calling the BPF sock_ops function. There are a set of compile checks added in tcp.c to detect if the internal and BPF values differ so we can make the necessary fixes. New op: BPF_SOCK_OPS_STATE_CB. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Add BPF_SOCK_OPS_RETRANS_CBLawrence Brakmo
Adds support for calling sock_ops BPF program when there is a retransmission. Three arguments are used; one for the sequence number, another for the number of segments retransmitted, and the last one for the return value of tcp_transmit_skb (0 => success). Does not include syn-ack retransmissions. New op: BPF_SOCK_OPS_RETRANS_CB. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Add sock_ops R/W access to tclassLawrence Brakmo
Adds direct write access to sk_txhash and access to tclass for ipv6 flows through getsockopt and setsockopt. Sample usage for tclass: bpf_getsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v, sizeof(v)) where skops is a pointer to the ctx (struct bpf_sock_ops). Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Add support for reading sk_state and moreLawrence Brakmo
Add support for reading many more tcp_sock fields state, same as sk->sk_state rtt_min same as sk->rtt_min.s[0].v (current rtt_min) snd_ssthresh rcv_nxt snd_nxt snd_una mss_cache ecn_flags rate_delivered rate_interval_us packets_out retrans_out total_retrans segs_in data_segs_in segs_out data_segs_out lost_out sacked_out sk_txhash bytes_received (__u64) bytes_acked (__u64) Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Add sock_ops RTO callbackLawrence Brakmo
Adds an optional call to sock_ops BPF program based on whether the BPF_SOCK_OPS_RTO_CB_FLAG is set in bpf_sock_ops_flags. The BPF program is passed 2 arguments: icsk_retransmits and whether the RTO has expired. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Adds field bpf_sock_ops_cb_flags to tcp_sockLawrence Brakmo
Adds field bpf_sock_ops_cb_flags to tcp_sock and bpf_sock_ops. Its primary use is to determine if there should be calls to sock_ops bpf program at various points in the TCP code. The field is initialized to zero, disabling the calls. A sock_ops BPF program can set it, per connection and as necessary, when the connection is established. It also adds support for reading and writting the field within a sock_ops BPF program. Reading is done by accessing the field directly. However, writing is done through the helper function bpf_sock_ops_cb_flags_set, in order to return an error if a BPF program is trying to set a callback that is not supported in the current kernel (i.e. running an older kernel). The helper function returns 0 if it was able to set all of the bits set in the argument, a positive number containing the bits that could not be set, or -EINVAL if the socket is not a full TCP socket. Examples of where one could call the bpf program: 1) When RTO fires 2) When a packet is retransmitted 3) When the connection terminates 4) When a packet is sent 5) When a packet is received Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-25bpf: Support passing args to sock_ops bpf functionLawrence Brakmo
Adds support for passing up to 4 arguments to sock_ops bpf functions. It reusues the reply union, so the bpf_sock_ops structures are not increased in size. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>