src/liboping.c: Document ping_open_socket().

Also make sure that obj->errmsg is set on all error paths and evaluate
errno as soon as possible so that calls to close() and such don't reset it.

diff --git a/src/liboping.c b/src/liboping.c
index edc3522..4579ab0 100644 (file)
--- a/src/liboping.c
+++ b/src/liboping.c
@@ -969,6 +969,9 @@ static void ping_free (pinghost_t *ph)
        free (ph);
 }
 
+/* ping_open_socket opens, initializes and returns a new raw socket to use for
+ * ICMPv4 or ICMPv6 packets. addrfam must be either AF_INET or AF_INET6. On
+ * error, -1 is returned and obj->errmsg is set appropriately. */
 static int ping_open_socket(pingobj_t *obj, int addrfam)
 {
        int fd;
@@ -982,27 +985,28 @@ static int ping_open_socket(pingobj_t *obj, int addrfam)
        }
        else /* this should not happen */
        {
+               ping_set_error (obj, "ping_open_socket", "Unknown address family");
                dprintf ("Unknown address family: %i\n", addrfam);
-               return (-1);
+               return -1;
        }
 
        if (fd == -1)
        {
+               ping_set_errno (obj, errno);
 #if WITH_DEBUG
                char errbuf[PING_ERRMSG_LEN];
                dprintf ("socket: %s\n",
                                sstrerror (errno, errbuf, sizeof (errbuf)));
 #endif
-               ping_set_errno (obj, errno);
                return -1;
        }
        else if (fd >= FD_SETSIZE)
        {
+               ping_set_errno (obj, EMFILE);
                dprintf ("socket(2) returned file descriptor %d, which is above the file "
                         "descriptor limit for select(2) (FD_SETSIZE = %d)\n",
                         fd, FD_SETSIZE);
                close (fd);
-               ping_set_errno (obj, EMFILE);
                return -1;
        }
 
@@ -1013,12 +1017,12 @@ static int ping_open_socket(pingobj_t *obj, int addrfam)
 
                if (bind (fd, obj->srcaddr, obj->srcaddrlen) == -1)
                {
+                       ping_set_errno (obj, errno);
 #if WITH_DEBUG
                        char errbuf[PING_ERRMSG_LEN];
                        dprintf ("bind: %s\n",
                                        sstrerror (errno, errbuf, sizeof (errbuf)));
 #endif
-                       ping_set_errno (obj, errno);
                        close (fd);
                        return -1;
                }
@@ -1030,12 +1034,12 @@ static int ping_open_socket(pingobj_t *obj, int addrfam)
                if (setsockopt (fd, SOL_SOCKET, SO_BINDTODEVICE,
                                obj->device, strlen (obj->device) + 1) != 0)
                {
+                       ping_set_errno (obj, errno);
 #if WITH_DEBUG
                        char errbuf[PING_ERRMSG_LEN];
                        dprintf ("setsockopt (SO_BINDTODEVICE): %s\n",
                                        sstrerror (errno, errbuf, sizeof (errbuf)));
 #endif
-                       ping_set_errno (obj, errno);
                        close (fd);
                        return -1;
                }
@@ -1069,12 +1073,12 @@ static int ping_open_socket(pingobj_t *obj, int addrfam)
                                &opt, sizeof (opt));
                if (status != 0)
                {
+                       ping_set_errno (obj, errno);
 #if WITH_DEBUG
                        char errbuf[PING_ERRMSG_LEN];
                        dprintf ("setsockopt (SO_TIMESTAMP): %s\n",
                                        sstrerror (errno, errbuf, sizeof (errbuf)));
 #endif
-                       ping_set_errno (obj, errno);
                        close (fd);
                        return -1;
                }