]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
bpf: tcp_bpf_recvmsg should return EAGAIN when nonblocking and no data
authorJohn Fastabend <john.fastabend@gmail.com>
Mon, 29 Oct 2018 19:31:28 +0000 (12:31 -0700)
committerDaniel Borkmann <daniel@iogearbox.net>
Tue, 30 Oct 2018 22:31:22 +0000 (23:31 +0100)
commit27b31e68bc9fc25c519c7772fa23913687218d5f
treeefc8ca26473eb98d494b0ad3c01af4d5a54050f8
parentb31d30d9be32d41bef3e6076a965565d3a3d8005
bpf: tcp_bpf_recvmsg should return EAGAIN when nonblocking and no data

We return 0 in the case of a nonblocking socket that has no data
available. However, this is incorrect and may confuse applications.
After this patch we do the correct thing and return the error
EAGAIN.

Quoting return codes from recvmsg manpage,

EAGAIN or EWOULDBLOCK
 The socket is marked nonblocking and the receive operation would
 block, or a receive timeout had been set and the timeout expired
 before data was received.

Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
net/ipv4/tcp_bpf.c