Avoid updating too often if ISP spams RAs

[odhcp6c.git] / src / odhcp6c.c

diff --git a/src/odhcp6c.c b/src/odhcp6c.c
index 7e0710b7e1a10a5d59bb72bd13b48cdebcd8a01b..e81b15f92a5bcfc0a8b54895a336cdf46a8d6ace 100644 (file)
--- a/src/odhcp6c.c
+++ b/src/odhcp6c.c
@@ -58,11 +58,12 @@ int main(_unused int argc, char* const argv[])
        enum odhcp6c_ia_mode ia_na_mode = IA_MODE_TRY;
        enum odhcp6c_ia_mode ia_pd_mode = IA_MODE_TRY;
        static struct in6_addr ifid = IN6ADDR_ANY_INIT;
+       int sol_timeout = 120;
 
        bool help = false, daemonize = false;
        int logopt = LOG_PID;
        int c, request_pd = 0;
-       while ((c = getopt(argc, argv, "S::N:P:Fc:i:r:s:khedp:")) != -1) {
+       while ((c = getopt(argc, argv, "S::N:P:Fc:i:r:s:kt:hedp:")) != -1) {
                switch (c) {
                case 'S':
                        allow_slaac_only = (optarg) ? atoi(optarg) : -1;
@@ -135,6 +136,10 @@ int main(_unused int argc, char* const argv[])
                        release = false;
                        break;
 
+               case 't':
+                       sol_timeout = atoi(optarg);
+                       break;
+
                case 'e':
                        logopt |= LOG_PERROR;
                        break;
@@ -168,8 +173,8 @@ int main(_unused int argc, char* const argv[])
        signal(SIGUSR2, sighandler);
 
        if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
-                       init_dhcpv6(ifname, request_pd) || ra_init(ifname, &ifid) ||
-                       script_init(script, ifname)) {
+                       init_dhcpv6(ifname, request_pd, sol_timeout) ||
+                       ra_init(ifname, &ifid) || script_init(script, ifname)) {
                syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
                return 3;
        }
@@ -345,6 +350,7 @@ static int usage(void)
        "       -r <options>    Options to be requested (comma-separated)\n"
        "       -s <script>     Status update script (/usr/sbin/odhcp6c-update)\n"
        "       -k              Don't send a RELEASE when stopping\n"
+       "       -t <seconds>    Maximum timeout for DHCPv6-SOLICIT (120)\n"
        "\nInvocation options:\n"
        "       -p <pidfile>    Set pidfile (/var/run/6relayd.pid)\n"
        "       -d              Daemonize\n"
@@ -457,17 +463,23 @@ struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct
 }
 
 
-void odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
+bool odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
 {
        size_t len;
        struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
        struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
+       bool changed = true;
 
        if (x && x->valid > new->valid && new->valid < safe)
                new->valid = safe;
 
        if (new->valid > 0) {
                if (x) {
+                       if (new->valid >= x->valid && new->valid - x->valid < 60 &&
+                                       new->preferred >= x->preferred &&
+                                       new->preferred - x->preferred < 60 &&
+                                       x->class == new->class)
+                               changed = false;
                        x->valid = new->valid;
                        x->preferred = new->preferred;
                        x->class = new->class;
@@ -477,12 +489,13 @@ void odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *n
        } else if (x) {
                odhcp6c_remove_state(state, (x - start) * sizeof(*x), sizeof(*x));
        }
+       return changed;
 }
 
 
-void odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
+bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
 {
-       odhcp6c_update_entry_safe(state, new, 0);
+       return odhcp6c_update_entry_safe(state, new, 0);
 }