zcip: open ARP socket before openlog

(else we can thrash syslog socket)

1 files changed, 13 insertions, 11 deletions

diff --git a/networking/zcip.c b/networking/zcip.c
index 6e1c0d148..d8d9a2de1 100644
--- a/networking/zcip.c
+++ b/networking/zcip.c
@@ -178,7 +178,7 @@ int zcip_main(int argc, char **argv)
         char *r_opt;
         unsigned opts;
 
-        /* Ugly trick, but I want these zeroed in one go */
+        // ugly trick, but I want these zeroed in one go
         struct {
                 const struct in_addr null_ip;
                 const struct ether_addr null_addr;
@@ -212,8 +212,17 @@ int zcip_main(int argc, char **argv)
         // exactly 2 args; -v accumulates and implies -f
         opt_complementary = "=2:vv:vf";
         opts = getopt32(argv, "fqr:v", &r_opt, &verbose);
+#if !BB_MMU
+        // on NOMMU reexec early (or else we will rerun things twice)
+        if (!FOREGROUND)
+                bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
+#endif
+        // open an ARP socket
+        // (need to do it before openlog to prevent openlog from taking
+        // fd 3 (sock_fd==3))
+        xmove_fd(xsocket(AF_PACKET, SOCK_PACKET, htons(ETH_P_ARP)), sock_fd);
         if (!FOREGROUND) {
-                /* Do it early, before all bb_xx_msg calls */
+                // do it before all bb_xx_msg calls
                 openlog(applet_name, 0, LOG_DAEMON);
                 logmode |= LOGMODE_SYSLOG;
         }
@@ -224,11 +233,6 @@ int zcip_main(int argc, char **argv)
                         bb_error_msg_and_die("invalid link address");
                 }
         }
-        // On NOMMU reexec early (or else we will rerun things twice)
-#if !BB_MMU
-        if (!FOREGROUND)
-                bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
-#endif
         argc -= optind;
         argv += optind;
 
@@ -247,8 +251,6 @@ int zcip_main(int argc, char **argv)
         //TODO: are we leaving sa_family == 0 (AF_UNSPEC)?!
         safe_strncpy(saddr.sa_data, intf, sizeof(saddr.sa_data));
 
-        // open an ARP socket
-        xmove_fd(xsocket(AF_PACKET, SOCK_PACKET, htons(ETH_P_ARP)), sock_fd);
         // bind to the interface's ARP socket
         xbind(sock_fd, &saddr, sizeof(saddr));
 
@@ -288,7 +290,7 @@ int zcip_main(int argc, char **argv)
         // restarting after address conflicts:
         //  - start with some address we want to try
         //  - short random delay
-        //  - arp probes to see if another host else uses it
+        //  - arp probes to see if another host uses it
         //  - arp announcements that we're claiming it
         //  - use it
         //  - defend it, within limits
@@ -319,7 +321,7 @@ int zcip_main(int argc, char **argv)
                 switch (safe_poll(fds, 1, timeout_ms)) {
 
                 default:
-                        /*bb_perror_msg("poll"); - done in safe_poll */
+                        //bb_perror_msg("poll"); - done in safe_poll
                         return EXIT_FAILURE;
 
                 // timeout