[patch] fstat: print the owner process for UNIX domain sockets

Hi.
This patch adds support for fstat(1) to identify which process opened the
specified socket file, to bring in line with regular files. E.g.:

# fstat /var/run/devd.pipe
USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W NAME
root     devd        1259    4* local stream fffffe0002a1a870
/var/run/devd.pipe
# fstat /var/run/logpriv
USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W NAME
root     syslogd     1495    5* local dgram fffffe0002a1a3c0  /var/run/logpriv

Comments are welcome.

Index: usr.bin/fstat/fstat.c
===================================================================
--- usr.bin/fstat/fstat.c       (revision 230505)
+++ usr.bin/fstat/fstat.c       (working copy)
_at__at_ -38,6 +38,7 _at__at_ __FBSDID("$FreeBSD$");
 #include <sys/socketvar.h>
 #include <sys/sysctl.h>
 #include <sys/queue.h>
+#include <sys/un.h>

 #include <netinet/in.h>

_at__at_ -224,28 +225,53 _at__at_ static void
 print_file_info(struct procstat *procstat, struct filestat *fst,
     const char *uname, const char *cmd, int pid)
 {
+       struct sockstat sock;
        struct vnstat vn;
        DEVS *d;
        const char *filename;
        int error, fsmatch = 0;
        char errbuf[_POSIX2_LINE_MAX];

+       error = 0;
        filename = NULL;
        if (checkfile != 0) {
-               if (fst->fs_type != PS_FST_TYPE_VNODE &&
-                   fst->fs_type != PS_FST_TYPE_FIFO)
+               switch (fst->fs_type) {
+               case PS_FST_TYPE_VNODE:
+               case PS_FST_TYPE_FIFO:
+                       error = procstat_get_vnode_info(procstat, fst,
&vn, errbuf);
+                       break;
+               case PS_FST_TYPE_SOCKET:
+                       error = procstat_get_socket_info(procstat,
fst, &sock, errbuf);
+                       break;
+               default:
                        return;
-               error = procstat_get_vnode_info(procstat, fst, &vn, errbuf);
+               }
                if (error != 0)
                        return;

                for (d = devs; d != NULL; d = d->next)
-                       if (d->fsid == vn.vn_fsid) {
-                               fsmatch = 1;
-                               if ((unsigned)d->ino == vn.vn_fileid) {
-                                       filename = d->name;
-                                       break;
+                       switch (fst->fs_type) {
+                       case PS_FST_TYPE_VNODE:
+                       case PS_FST_TYPE_FIFO:
+                               if (d->fsid == vn.vn_fsid) {
+                                       fsmatch = 1;
+                                       if ((unsigned)d->ino == vn.vn_fileid) {
+                                               filename = d->name;
+                                               break;
+                                       }
                                }
+                               break;
+                       case PS_FST_TYPE_SOCKET:
+                               if (sock.dom_family == AF_UNIX) {
+                                       fsmatch = 1;
+                                       if (strcmp(((struct sockaddr_un *)
+                                           (&sock.sa_local))->sun_path,
+                                           d->name) == 0) {
+                                               filename = d->name;
+                                               break;
+                                       }
+                               }
+                               break;
                        }
                if (fsmatch == 0 || (filename == NULL && fsflg == 0))
                        return;

-- 
wbr,
pluknet