arping: code shrink

function                                             old     new   delta
catcher                                              310     309      -1
arping_main                                         1668    1641     -27

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

1 files changed, 20 insertions, 19 deletions

diff --git a/networking/arping.c b/networking/arping.c
index 59092a7d7..788fded3c 100644
--- a/networking/arping.c
+++ b/networking/arping.c
@@ -28,6 +28,7 @@
 //usage:     "\n        -A              ARP answer mode, update your neighbors"
 //usage:     "\n        -c N            Stop after sending N ARP requests"
 //usage:     "\n        -w TIMEOUT      Seconds to wait for ARP reply"
+//NB: in iputils-s20160308, iface is mandatory, no default
 //usage:     "\n        -I IFACE        Interface to use (default eth0)"
 //usage:     "\n        -s SRC_IP       Sender IP address"
 //usage:     "\n        DST_IP          Target IP address"
@@ -56,8 +57,8 @@ enum {
 #define GETOPT32(str_timeout, device, source) \
         getopt32(argv, "^" \
                 "UDAqfbc:+w:I:s:" \
-                /* Dad also sets quit_on_reply, */ \
-                /* Advert also sets unsolicited: */ \
+                /* DAD also sets quit_on_reply, */ \
+                /* advert also sets unsolicited: */ \
                 "\0" "=1:Df:AU", \
                 &count, &str_timeout, &device, &source \
         );
@@ -67,7 +68,6 @@ struct globals {
         struct in_addr dst;
         struct sockaddr_ll me;
         struct sockaddr_ll he;
-        int sock_fd;
 
         int count; // = -1;
         unsigned last;
@@ -80,7 +80,9 @@ struct globals {
         unsigned brd_recv;
         unsigned req_recv;
 
+        /* should be in main(), but are here to reduce stack use: */
         struct ifreq ifr;
+        struct sockaddr_in probe_saddr;
         sigset_t sset;
         unsigned char packet[4096];
 } FIX_ALIASING;
@@ -88,7 +90,6 @@ struct globals {
 #define dst        (G.dst       )
 #define me         (G.me        )
 #define he         (G.he        )
-#define sock_fd    (G.sock_fd   )
 #define count      (G.count     )
 #define last       (G.last      )
 #define timeout_us (G.timeout_us)
@@ -106,6 +107,8 @@ struct globals {
         count = -1; \
 } while (0)
 
+#define sock_fd 3
+
 static int send_pack(struct in_addr *src_addr,
                         struct in_addr *dst_addr,
                         struct sockaddr_ll *ME,
@@ -299,7 +302,7 @@ int arping_main(int argc UNUSED_PARAM, char **argv)
 
         INIT_G();
 
-        sock_fd = xsocket(AF_PACKET, SOCK_DGRAM, 0);
+        xmove_fd(xsocket(AF_PACKET, SOCK_DGRAM, 0), sock_fd);
 
         // If you ever change BB_SUID_DROP to BB_SUID_REQUIRE,
         // drop suid root privileges here:
@@ -351,31 +354,29 @@ int arping_main(int argc UNUSED_PARAM, char **argv)
                 src = dst;
 
         if (!(option_mask32 & DAD) || src.s_addr) {
-                struct sockaddr_in saddr;
+                /*struct sockaddr_in probe_saddr;*/
                 int probe_fd = xsocket(AF_INET, SOCK_DGRAM, 0);
 
                 setsockopt_bindtodevice(probe_fd, device);
-                memset(&saddr, 0, sizeof(saddr));
-                saddr.sin_family = AF_INET;
+
+                /*memset(&G.probe_saddr, 0, sizeof(G.probe_saddr)); - zeroed by INIT_G */
+                G.probe_saddr.sin_family = AF_INET;
                 if (src.s_addr) {
                         /* Check that this is indeed our IP */
-                        saddr.sin_addr = src;
-                        xbind(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));
+                        G.probe_saddr.sin_addr = src;
+                        xbind(probe_fd, (struct sockaddr *) &G.probe_saddr, sizeof(G.probe_saddr));
                 } else { /* !(option_mask32 & DAD) case */
                         /* Find IP address on this iface */
-                        saddr.sin_port = htons(1025);
-                        saddr.sin_addr = dst;
+                        G.probe_saddr.sin_port = htons(1025);
+                        G.probe_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));
-                        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");
-                        if (saddr.sin_family != AF_INET)
+                        xconnect(probe_fd, (struct sockaddr *) &G.probe_saddr, sizeof(G.probe_saddr));
+                        bb_getsockname(probe_fd, (struct sockaddr *) &G.probe_saddr, sizeof(G.probe_saddr));
+                        if (G.probe_saddr.sin_family != AF_INET)
                                 bb_error_msg_and_die("no IP address configured");
-                        src = saddr.sin_addr;
+                        src = G.probe_saddr.sin_addr;
                 }
                 close(probe_fd);
         }