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>

diff --git a/networking/arping.c b/networking/arping.c
index 59092a7d75a84b521e020419511546a1af2140ff..788fded3ca363918054989fd657559e1e1aa6a35 100644 (file)
--- 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);
        }