On 1/24/21 4:10 PM, Alejandro Colomar wrote:
> From: Pali Rohár <pali@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Signed-off-by: Alejandro Colomar <alx.manpages@xxxxxxxxx>
Hello Alex, Pali,
Thanks. Patch applied.
Cheers,
Michael
> ---
> man7/sock_diag.7 | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/man7/sock_diag.7 b/man7/sock_diag.7
> index b732b2571..569106dd6 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)) {
>
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
