libbb: introduce and use bb_getsockname()

function                                             old     new   delta
bb_getsockname                                         -      18     +18
xrtnl_open                                            88      83      -5
do_iplink                                           1216    1209      -7
arping_main                                         1686    1668     -18
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/3 up/down: 18/-30)            Total: -12 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 5 insertions, 10 deletions

diff --git a/networking/arping.c b/networking/arping.c
index a16f04b9f..59092a7d7 100644
--- a/networking/arping.c
+++ b/networking/arping.c
@@ -363,15 +363,13 @@ int arping_main(int argc UNUSED_PARAM, char **argv)
                         xbind(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
                 } else { /* !(option_mask32 & DAD) case */
                         /* Find IP address on this iface */
-                        socklen_t alen = sizeof(saddr);
-
                         saddr.sin_port = htons(1025);
                         saddr.sin_addr = dst;
 
                         if (setsockopt_SOL_SOCKET_1(probe_fd, SO_DONTROUTE) != 0)
                                 bb_perror_msg("setsockopt(%s)", "SO_DONTROUTE");
                         xconnect(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
-                        getsockname(probe_fd, (struct sockaddr *) &saddr, &alen);
+                        bb_getsockname(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
                         //never happens:
                         //if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) == -1)
                         //      bb_perror_msg_and_die("getsockname");
@@ -387,13 +385,10 @@ int arping_main(int argc UNUSED_PARAM, char **argv)
         me.sll_protocol = htons(ETH_P_ARP);
         xbind(sock_fd, (struct sockaddr *) &me, sizeof(me));
 
-        {
-                socklen_t alen = sizeof(me);
-                getsockname(sock_fd, (struct sockaddr *) &me, &alen);
-                //never happens:
-                //if (getsockname(sock_fd, (struct sockaddr *) &me, &alen) == -1)
-                //      bb_perror_msg_and_die("getsockname");
-        }
+        bb_getsockname(sock_fd, (struct sockaddr *) &me, sizeof(me));
+        //never happens:
+        //if (getsockname(sock_fd, (struct sockaddr *) &me, &alen) == -1)
+        //      bb_perror_msg_and_die("getsockname");
         if (me.sll_halen == 0) {
                 bb_error_msg(err_str, "is not ARPable (no ll address)");
                 BUILD_BUG_ON(DAD != 2);