Improve the structure of linux netlink messaging code

diff --git a/interface.c b/interface.c
index e4625a13e4569678b9c6da897f68c40f09b7c079..6177380fb493f080b40e39cab216a50c6b543baf 100644 (file)
--- a/interface.c
+++ b/interface.c
@@ -705,6 +705,7 @@ static int send_netlink(struct nlmsghdr *hdr)
                for (h.buffer = buffer; bytes >= (signed) sizeof (*h.nlm); ) {
                        int len = h.nlm->nlmsg_len;
                        int l = len - sizeof (*h.nlm);
+                       struct nlmsgerr *err = (struct nlmsgerr *) NLMSG_DATA (h.nlm);
 
                        if (l < 0 || len > bytes) {
                                if (msg.msg_flags & MSG_TRUNC)
@@ -714,45 +715,38 @@ static int send_netlink(struct nlmsghdr *hdr)
                                goto eexit;
                        }
 
+                       /* Ensure it's our message */
                        if (nl.nl_pid != 0 ||
                                (pid_t) h.nlm->nlmsg_pid != mypid ||
                                h.nlm->nlmsg_seq != seq)
-                               /* Message isn't for us, so skip it */
-                               goto next;
-
+                       {
+                               /* Next Message */
+                               bytes -= NLMSG_ALIGN (len);
+                               h.buffer += NLMSG_ALIGN (len);
+                               continue;
+                       }
+                       
                        /* We get an NLMSG_ERROR back with a code of zero for success */
-                       if (h.nlm->nlmsg_type == NLMSG_ERROR) {
-                               struct nlmsgerr *err = (struct nlmsgerr *) NLMSG_DATA (h.nlm);
-                               if ((unsigned) l < sizeof (struct nlmsgerr))
-                                       logger (LOG_ERR, "netlink: truncated error message");
-                               else {
-                                       errno = -err->error;
-                                       if (errno == 0) {
-                                               close (s);
-                                               free (buffer);
-                                               return 0;
-                                       }
-
-                                       /* Don't report on something already existing */
-                                       if (errno != EEXIST)
-                                               logger (LOG_ERR, "netlink: %s", strerror (errno));
-                               }
+                       if (h.nlm->nlmsg_type != NLMSG_ERROR) {
+                               logger (LOG_ERR, "netlink: unexpected reply %d", h.nlm->nlmsg_type);
                                goto eexit;
                        }
 
-                       logger (LOG_ERR, "netlink: unexpected reply");
-next:
-                       bytes -= NLMSG_ALIGN (len);
-                       h.buffer += NLMSG_ALIGN (len);
-               }
+                       if ((unsigned) l < sizeof (struct nlmsgerr)) {
+                               logger (LOG_ERR, "netlink: error truncated");
+                               goto eexit;
+                       }
 
-               if (msg.msg_flags & MSG_TRUNC) {
-                       logger (LOG_ERR, "netlink: truncated message");
-                       continue;
-               }
+                       if (err->error == 0) {
+                               close (s);
+                               free (buffer);
+                               return 0;
+                       }
 
-               if (bytes) {
-                       logger (LOG_ERR, "netlink: remnant of size %d", bytes);
+                       errno = -err->error;
+                       /* Don't report on something already existing */
+                       if (errno != EEXIST)
+                               logger (LOG_ERR, "netlink: %s", strerror (errno));
                        goto eexit;
                }
        }