diff options
Diffstat (limited to 'net/core/datagram.c')
| -rw-r--r-- | net/core/datagram.c | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index 176eb5834746..37c89d0933b7 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -50,7 +50,7 @@ #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/pagemap.h> -#include <linux/uio.h> +#include <linux/iov_iter.h> #include <linux/indirect_call_wrapper.h> #include <net/protocol.h> @@ -716,6 +716,54 @@ int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from) } EXPORT_SYMBOL(zerocopy_sg_from_iter); +static __always_inline +size_t copy_to_user_iter_csum(void __user *iter_to, size_t progress, + size_t len, void *from, void *priv2) +{ + __wsum next, *csum = priv2; + + next = csum_and_copy_to_user(from + progress, iter_to, len); + *csum = csum_block_add(*csum, next, progress); + return next ? 0 : len; +} + +static __always_inline +size_t memcpy_to_iter_csum(void *iter_to, size_t progress, + size_t len, void *from, void *priv2) +{ + __wsum *csum = priv2; + + *csum = csum_and_memcpy(iter_to, from + progress, len, *csum, progress); + return 0; +} + +static size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, + struct iov_iter *i) +{ + struct csum_state *csstate = _csstate; + __wsum sum; + + if (WARN_ON_ONCE(i->data_source)) + return 0; + if (unlikely(iov_iter_is_discard(i))) { + // can't use csum_memcpy() for that one - data is not copied + csstate->csum = csum_block_add(csstate->csum, + csum_partial(addr, bytes, 0), + csstate->off); + csstate->off += bytes; + return bytes; + } + + sum = csum_shift(csstate->csum, csstate->off); + + bytes = iterate_and_advance2(i, bytes, (void *)addr, &sum, + copy_to_user_iter_csum, + memcpy_to_iter_csum); + csstate->csum = csum_shift(sum, csstate->off); + csstate->off += bytes; + return bytes; +} + /** * skb_copy_and_csum_datagram - Copy datagram to an iovec iterator * and update a checksum. |