More verbose failures, early logging also to stderr.

diff --git a/6bed4peer.c b/6bed4peer.c
index 66fee24..b4670f9 100644 (file)
--- a/6bed4peer.c
+++ b/6bed4peer.c
@@ -334,10 +334,12 @@ syslog (LOG_DEBUG, "Found Interface Index %d for name %s\n", ifreq.ifr_ifindex,
        char cmd [512+1];
        snprintf (cmd, 512, "/sbin/sysctl -q -w net.ipv6.conf.%s.forwarding=0", ifreq.ifr_name);
        if (ok && system (cmd) != 0) {
+               fprintf (stderr, "Failed command: %s\n", cmd);
                ok = false;
        }
        snprintf (cmd, 512, "/sbin/sysctl -q -w net.ipv6.conf.%s.accept_dad=0", ifreq.ifr_name);
        if (ok && system (cmd) != 0) {
+               fprintf (stderr, "Failed command: %s\n", cmd);
                ok = false;
        }
        if (!ok) {
@@ -357,15 +359,18 @@ bool setup_tunnel_address (void) {
        }
        snprintf (cmd, 512, "/sbin/ip link set %s up mtu %d", ifreq.ifr_name, MTU);
        if (ok && system (cmd) != 0) {
+               fprintf (stderr, "Failed command: %s\n", cmd);
                ok = false;
        }
        snprintf (cmd, 512, "/sbin/ip -6 addr add %s/114 dev %s", v6prefix, ifreq.ifr_name);
        if (ok && system (cmd) != 0) {
+               fprintf (stderr, "Failed command: %s\n", cmd);
                ok = false;
        }
        if (default_route) {
                snprintf (cmd, 512, "/sbin/ip -6 route add default via fe80:: dev %s metric 1042", ifreq.ifr_name);
                if (ok && system (cmd) != 0) {
+                       fprintf (stderr, "Failed command: %s\n", cmd);
                        ok = false;
                }
        }
@@ -766,15 +771,17 @@ syslog (LOG_DEBUG, "Message of %zd bytes from neighbor cache, total is now %zd\n
                        if (resp->hd.nlmsg_type == NLMSG_DONE) {
                                return false;
                        } else if (resp->hd.nlmsg_type != RTM_NEWNEIGH) {
-                               syslog (LOG_ERR, "Kernel sent an unexpected nlmsg_type 0x%02x, ending neighbor interpretation\n", resp->hd.nlmsg_type);
+                               syslog (LOG_ERR, "Kernel sent an unexpected nlmsg_type 0x%02x, ending neighbor interpretation", resp->hd.nlmsg_type);
                                ok = false;
                        } else if (resp->nd.ndm_ifindex != ifreq.ifr_ifindex) {
+                               syslog (LOG_ERR, "Kernel sent an unexpected interface index");
                                ok = false;
                        } else if (resp->nd.ndm_family != AF_INET6) {
                                syslog (LOG_ERR, "Kernel reported unknown neighbor family %d\n", resp->nd.ndm_family);
                                ok = false;
                        } else
                        if (!(resp->nd.ndm_state & (NUD_REACHABLE | NUD_DELAY | NUD_PROBE | NUD_PERMANENT | NUD_STALE))) {
+                               syslog (LOG_ERR, "Kernel sent a funnily flagged interface state");
                                ok = false;
                        }
                        struct rtattr *ra = (struct rtattr *) ((char *) &resp + pos + sizeof (struct nlmsghdr) + sizeof (struct ndmsg) + 8);
@@ -1644,59 +1651,68 @@ int process_args (int argc, char *argv []) {
                case 'r':
                        if (default_route) {
                                fprintf (stderr, "%s: You can only request default route setup once\n", program);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        default_route = true;
                        break;
                case 'l':
                        if (inet_pton (AF_INET, optarg, &v4bind.sin_addr.s_addr) != 1) {
                                fprintf (stderr, "%s: IPv4 address %s is not valid\n", program, optarg);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        break;
                case 'p':
                        tmpport = strtoul (optarg, &endarg, 10);
                        if ((*endarg) || (tmpport > 65535)) {
                                fprintf (stderr, "%s: UDP port number %s is not valid\n", program, optarg);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        if (tmpport & 0x0001) {
                                fprintf (stderr, "%s: UDP port number %ld is odd, which is not permitted\n", program, tmpport);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        v4bind.sin_port = htons (tmpport);
                        break;
                case 'f':
                        if (foreground) {
                                fprintf (stderr, "%s: You can only request foreground operation once\n", program);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        foreground = true;
                        break;
                case 'e':
                        if (log_to_stderr) {
                                fprintf (stderr, "%s: You can only specify logging to stderr once\n", program);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        log_to_stderr = true;
                        break;
                case 't':
                        if (v4ttl_mcast != -1) {
                                fprintf (stderr, "%s: You can set the ttl for multicast once\n", program);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        char *zero;
                        long setting = strtol(optarg, &zero, 10);
                        if (*zero || (setting < 0) || (setting > 255)) {
                                fprintf (stderr, "%s: Multicast radius must be a number in the range 0 to 255, inclusive, not %s\n", program, optarg);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        v4ttl_mcast = setting;
                        break;
                case 'k':
                        if (keepalive_ttl != -1) {
                                fprintf (stderr, "%s: You can only set the keepalive period and TTL once\n", program);
-                               exit (1);
+                               ok = 0;
+                               break;
                        }
                        char *rest;
                        keepalive_period = strtol (optarg, &rest, 10);
@@ -1705,7 +1721,8 @@ int process_args (int argc, char *argv []) {
                                keepalive_ttl = strtol (rest, &rest, 10);
                                if ((keepalive_ttl < 0) || (keepalive_ttl > 255)) {
                                        fprintf (stderr, "%s: The keepalive TTL must be in the range 0 to 255, inclusive\n", program);
-                                       exit (1);
+                                       ok = 0;
+                                       break;
                                }
                        } else {
                                keepalive_ttl = 3;
@@ -1747,9 +1764,12 @@ int process_args (int argc, char *argv []) {
        if (v6sox == -1) {
                if (geteuid () != 0) {
                        fprintf (stderr, "%s: You should be root, or use -d to specify an accessible tunnel device\n", program);
-                       return false;
+                       return 0;
                } else {
-                       return setup_tunnel ();
+                       ok = setup_tunnel ();
+                       if (!ok) {
+                               fprintf (stderr, "Failed to setup tunnel\n");
+                       }
                }
        }
 #else /* ! HAVE_SETUP_TUNNEL */
@@ -1793,9 +1813,15 @@ int main (int argc, char *argv []) {
 #endif
        //
        // Parse commandline arguments
+       openlog (program, LOG_NDELAY | LOG_PID | LOG_PERROR, LOG_DAEMON);
        if (!process_args (argc, argv)) {
+               fprintf (stderr, "Argument processing failed\n");
                exit (1);
        }
+       if (!log_to_stderr) {
+               closelog ();
+               openlog (program, LOG_NDELAY | LOG_PID, LOG_DAEMON);
+       }
        //
        // Construct the 6bed4 Router's complete link-layer address
        router_linklocal_address_complete [8] = (ntohs (v4peer.sin_port) & 0xff) ^ 0x02;
@@ -1805,9 +1831,6 @@ int main (int argc, char *argv []) {
        router_linklocal_address_complete [12] = 0xfe;
        memcpy (router_linklocal_address_complete + 13, &((uint8_t *) &v4peer.sin_addr) [1], 3);
        //
-       // Open the syslog channel
-       openlog (program, LOG_NDELAY | LOG_PID | ( log_to_stderr? LOG_PERROR: 0), LOG_DAEMON);
-       //
        // Create memory for the freequeue buffer
        freequeue = calloc (freequeue_items, sizeof (struct ndqueue));
        if (!freequeue) {