rtnl: Add support for RFC6106 DNSSL

diff --git a/src/rtnl.c b/src/rtnl.c
index b56a80d..96f8061 100644 (file)
--- a/src/rtnl.c
+++ b/src/rtnl.c
@@ -1044,11 +1044,67 @@ static void *rtnl_nd_opt_rdnss(struct nd_opt_hdr *opt, guint32 *lifetime,
        return optint + 2;
 }
 
+static const char **rtnl_nd_opt_dnssl(struct nd_opt_hdr *opt, guint32 *lifetime)
+{
+       const char **domains = NULL;
+       guint32 *optint = (void *)opt;
+       unsigned char *optc = (void *)&optint[2];
+       int data_len = (opt->nd_opt_len * 8) - 8;
+       int nr_domains = 0;
+       int i, tmp;
+
+       if (*lifetime > ntohl(optint[1]))
+               *lifetime = ntohl(optint[1]);
+
+       /* Turn it into normal strings by converting the length bytes into '.',
+          and count how many search domains there are while we're at it. */
+       i = 0;
+       while (i < data_len) {
+               if (optc[i] > 0x3f) {
+                       DBG("DNSSL contains compressed elements in violation of RFC6106");
+                       return NULL;
+               }
+
+               if (optc[i] == 0) {
+                       nr_domains++;
+                       i++;
+                       /* Check for double zero */
+                       if (i < data_len && optc[i] == 0)
+                               break;
+                       continue;
+               }
+
+               tmp = i;
+               i += optc[i] + 1;
+
+               if (i >= data_len) {
+                       DBG("DNSSL data overflows option length");
+                       return NULL;
+               }
+
+               optc[tmp] = '.';
+       }
+
+       domains = g_try_new0(const char *, nr_domains + 1);
+       if (!domains)
+               return NULL;
+
+       /* Now point to the normal strings, missing out the leading '.' that
+          each of them will have now. */
+       for (i = 0; i < nr_domains; i++) {
+               domains[i] = (char *)optc + 1;
+               optc += strlen((char *)optc) + 1;
+       }
+
+       return domains;
+}
+
 static void rtnl_newnduseropt(struct nlmsghdr *hdr)
 {
        struct nduseroptmsg *msg = (struct nduseroptmsg *) NLMSG_DATA(hdr);
        struct nd_opt_hdr *opt = (void *)&msg[1];
        guint32 lifetime = -1;
+       const char **domains = NULL;
        struct in6_addr *servers;
        int nr_servers = 0;
        int msglen = msg->nduseropt_opts_len;
@@ -1079,6 +1135,8 @@ static void rtnl_newnduseropt(struct nlmsghdr *hdr)
                if (opt->nd_opt_type == 25)
                        servers = rtnl_nd_opt_rdnss(opt, &lifetime,
                                                    &nr_servers);
+               else if (opt->nd_opt_type == 31)
+                       domains = rtnl_nd_opt_dnssl(opt, &lifetime);
        }
 
        if (nr_servers) {
@@ -1088,9 +1146,10 @@ static void rtnl_newnduseropt(struct nlmsghdr *hdr)
                for (i = 0; i < nr_servers; i++) {
                        if (inet_ntop(AF_INET6, servers + i, buf, sizeof(buf)))
                                connman_resolver_append_lifetime(interface,
-                                                       NULL, buf, lifetime);
+                                      domains?domains[0]:NULL, buf, lifetime);
                }
        }
+       g_free(domains);
        g_free(interface);
 }