2c7269b231
If the peer is closed, we will never get more data, so
tcp_bpf_wait_data will get stuck forever. In case we passed
MSG_DONTWAIT to recv(), we get EAGAIN but we should actually get
0.
>From man 2 recv:
RETURN VALUE
When a stream socket peer has performed an orderly shutdown, the
return value will be 0 (the traditional "end-of-file" return).
This patch makes tcp_bpf_wait_data always return 1 when the peer
socket has been shutdown. Either we have data available, and it would
have returned 1 anyway, or there isn't, in which case we'll call
tcp_recvmsg which does the right thing in this situation.
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/26038a28c21fea5d04d4bd4744c5686d3f2e5504.1591784177.git.sd@queasysnail.net
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.