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| author | Pali Rohár <pali@kernel.org> | 2021-01-24 16:10:39 +0100 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2021-01-25 08:01:56 +0100 |
| commit | bc766f2c0c7d9eb8bb64c1b22e723945e8abe33a (patch) | |
| tree | 2dd521288c6cb12857bb3bc2b8c73bfe1d961217 /man7 | |
| parent | 29dee4ce10a37e069200623e2d581a18a673b37d (diff) | |
| download | man-pages-bc766f2c0c7d9eb8bb64c1b22e723945e8abe33a.tar.gz | |
sock_diag.7: Fix recvmsg() usage in the example
The msg_name field for recvmsg() call points to a caller-allocated buffer
nladdr that is used to return the source address of the (netlink) socket.
As recvmsg() does not read this buffer and fills it for a caller, do not
initialize it and instead check its value in the example.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Diffstat (limited to 'man7')
| -rw-r--r-- | man7/sock_diag.7 | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/man7/sock_diag.7 b/man7/sock_diag.7 index 8b4ed340bf..97cab46327 100644 --- a/man7/sock_diag.7 +++ b/man7/sock_diag.7 @@ -753,9 +753,7 @@ static int receive_responses(int fd) { long buf[8192 / sizeof(long)]; - struct sockaddr_nl nladdr = { - .nl_family = AF_NETLINK - }; + struct sockaddr_nl nladdr; struct iovec iov = { .iov_base = buf, .iov_len = sizeof(buf) @@ -782,6 +780,11 @@ receive_responses(int fd) if (ret == 0) return 0; + if (nladdr.nl_family != AF_NETLINK) { + fputs("!AF_NETLINK\en", stderr); + return \-1; + } + const struct nlmsghdr *h = (struct nlmsghdr *) buf; if (!NLMSG_OK(h, ret)) { |