Re: [Patch iproute2] ss: add UNIX_DIAG_VFS and UNIX_DIAG_ICONS for unix sockets

[Stephen Hemminger <stephen@networkplumber.org>]

On Mon, 27 Aug 2018 14:46:52 -0700
Cong Wang <xiyou.wangcong@gmail.com> wrote:

> UNIX_DIAG_VFS and UNIX_DIAG_ICONS are never used by ss,
> make them available in ss -e output.
> 
> Cc: Stephen Hemminger <stephen@networkplumber.org>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> ---
>  misc/ss.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/misc/ss.c b/misc/ss.c
> index 41e7762b..d28bc1ec 100644
> --- a/misc/ss.c
> +++ b/misc/ss.c
> @@ -16,6 +16,7 @@
>  #include <sys/ioctl.h>
>  #include <sys/socket.h>
>  #include <sys/uio.h>
> +#include <sys/sysmacros.h>

Why is this included, it isn't on my system.

>  #include <netinet/in.h>
>  #include <string.h>
>  #include <errno.h>
> @@ -3604,6 +3605,28 @@ static int unix_show_sock(const struct sockaddr_nl *addr, struct nlmsghdr *nlh,
>  			out(" %c-%c",
>  			    mask & 1 ? '-' : '<', mask & 2 ? '-' : '>');
>  		}
> +		if (tb[UNIX_DIAG_VFS]) {
> +			struct unix_diag_vfs uv;
> +
> +			memcpy(&uv, RTA_DATA(tb[UNIX_DIAG_VFS]), sizeof(uv));

Copy here is unnecessary, you can just do:
			const struct unix_diag_vfs *uv
				= RTA_DATA(tb[UNIX_DIAG_VFS]);

> +			out(" ino:%u dev:%u/%u", uv.udiag_vfs_ino, major(uv.udiag_vfs_dev),
> +						 minor(uv.udiag_vfs_dev));
> +		}
> +		if (tb[UNIX_DIAG_ICONS]) {
> +			int len = RTA_PAYLOAD(tb[UNIX_DIAG_ICONS]);
> +			__u32 *peers = malloc(len);
> +			int i;

Ditto, allocation and copy are not necessary, just reference the data.

> +			if (!peers) {
> +				fprintf(stderr, "ss: failed to malloc buffer\n");
> +				abort();
> +			}
> +			memcpy(peers, RTA_DATA(tb[UNIX_DIAG_ICONS]), len);
> +			out(" peers:");
> +			for (i = 0; i < len / sizeof(__u32); i++)
> +				out(" %u", peers[i]);
> +			free(peers);
> +		}
>  	}
>  
>  	return 0;
> @@ -3641,6 +3664,8 @@ static int unix_show_netlink(struct filter *f)
>  	req.r.udiag_show = UDIAG_SHOW_NAME | UDIAG_SHOW_PEER | UDIAG_SHOW_RQLEN;
>  	if (show_mem)
>  		req.r.udiag_show |= UDIAG_SHOW_MEMINFO;
> +	if (show_details)
> +		req.r.udiag_show |= UDIAG_SHOW_VFS | UDIAG_SHOW_ICONS;
>  
>  	return handle_netlink_request(f, &req.nlh, sizeof(req), unix_show_sock);
>  }