diff options
| author |   Willem de Bruijn <willemb@google.com> | 2017-08-03 16:29:40 -0400 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-08-03 21:37:29 -0700 |
| commit | 76851d1212c11365362525e1e2c0a18c97478e6b (patch) | |
| tree | a9f9c1795f51c31d46e8282674e5d45f46ce1cbe /net | |
| parent | sock: add MSG_ZEROCOPY (diff) | |
| download | linux-dev-76851d1212c11365362525e1e2c0a18c97478e6b.tar.xz linux-dev-76851d1212c11365362525e1e2c0a18c97478e6b.zip | |
sock: add SOCK_ZEROCOPY sockopt
The send call ignores unknown flags. Legacy applications may already
unwittingly pass MSG_ZEROCOPY. Continue to ignore this flag unless a
socket opts in to zerocopy.
Introduce socket option SO_ZEROCOPY to enable MSG_ZEROCOPY processing.
Processes can also query this socket option to detect kernel support
for the feature. Older kernels will return ENOPROTOOPT.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/skbuff.c | 3 | ||||
| -rw-r--r-- | net/core/sock.c | 18 |
2 files changed, 21 insertions, 0 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0603e44950da..29e34bc6a17c 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -922,6 +922,9 @@ struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size) WARN_ON_ONCE(!in_task()); + if (!sock_flag(sk, SOCK_ZEROCOPY)) + return NULL; + skb = sock_omalloc(sk, 0, GFP_KERNEL); if (!skb) return NULL; diff --git a/net/core/sock.c b/net/core/sock.c index e8b696858cad..9ea988d25b0a 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1055,6 +1055,20 @@ set_rcvbuf: if (val == 1) dst_negative_advice(sk); break; + + case SO_ZEROCOPY: + if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) + ret = -ENOTSUPP; + else if (sk->sk_protocol != IPPROTO_TCP) + ret = -ENOTSUPP; + else if (sk->sk_state != TCP_CLOSE) + ret = -EBUSY; + else if (val < 0 || val > 1) + ret = -EINVAL; + else + sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool); + break; + default: ret = -ENOPROTOOPT; break; @@ -1383,6 +1397,10 @@ int sock_getsockopt(struct socket *sock, int level, int optname, v.val64 = sock_gen_cookie(sk); break; + case SO_ZEROCOPY: + v.val = sock_flag(sk, SOCK_ZEROCOPY); + break; + default: /* We implement the SO_SNDLOWAT etc to not be settable * (1003.1g 7). |