Merge pull request #274 from coova/rfc7710

Implement RFC 7710 - Captive Portal URI DHCP option

Author: wlanmac

src/cmdline.ggo

@@ -290,6 +290,8 @@ option "forcedns1port"   - "Force all DNS to a specific port" int default="0" no
 option "forcedns2"   - "Force all secondary DNS to a specific address" string no 
 option "forcedns2port"   - "Force all secondary DNS to a specific port" int default="0" no 
 
+option "rfc7710uri" - "DHCP Captive Portal URI. Defaults to http://uamlisten:uamport/prelogin." string no
+
 option "ipv6" - "Enable IPv6 support" flag off
 option "ipv6mode" - "IPv6 mode is either 6and4 (default), 4to6, or 6to4" string no
 option "ipv6only" - "Enable IPv6-Only" flag off

src/dhcp.c

@@ -3241,6 +3241,15 @@ static int dhcp_accept_opt(struct dhcp_conn_t *conn, uint8_t *o, int pos) {
   }
 #endif
 
+  if (_options.rfc7710uri) {
+    o[pos++] = DHCP_OPTION_CAPTIVE_PORTAL_URI;
+    o[pos++] = strlen(_options.rfc7710uri);
+    memcpy(&o[pos], _options.rfc7710uri, strlen(_options.rfc7710uri));
+    pos += strlen(_options.rfc7710uri);
+    if (_options.debug)
+      syslog(LOG_DEBUG, "DHCP Captive Portal URI %s\n", _options.rfc7710uri);
+  }
+
   o[pos++] = DHCP_OPTION_END;
 
   return pos;

src/dhcp.h

@@ -47,6 +47,7 @@
 #define DHCP_OPTION_CLIENT_IDENTIFIER 61
 #define DHCP_OPTION_CLIENT_FQDN    81
 #define DHCP_OPTION_82    82
+#define DHCP_OPTION_CAPTIVE_PORTAL_URI 160
 
 /* !!highly experimental!! */
 #define DHCP_OPTION_CALLED_STATION_ID  197

src/main-opt.c

@@ -721,6 +721,27 @@ int main(int argc, char **argv) {
   syslog(LOG_DEBUG, "DHCP Listen: %s", inet_ntoa(_options.dhcplisten));
   syslog(LOG_DEBUG, "UAM Listen: %s", inet_ntoa(_options.uamlisten));
 
+  if (args_info.rfc7710uri_given) {
+    /*
+     * When given, but set to an empty string, the feature is disabled.
+     */
+    if (strlen(args_info.rfc7710uri_arg) > 255) {
+      syslog(LOG_ERR, "Captive portal URI is too long for DHCP option.");
+      if (!args_info.forgiving_flag)
+	goto end_processing;
+    } else {
+      _options.rfc7710uri = STRDUP(args_info.rfc7710uri_arg);
+    }
+  } else {
+    /*
+     * When not explicitly set, default to the /prelogin routine.
+     */
+    char uri[128];
+    snprintf(uri, sizeof(uri), "http://%s:%d/prelogin",
+	     inet_ntoa(_options.uamlisten), _options.uamport);
+    _options.rfc7710uri = STRDUP(uri);
+  }
+
   if (!args_info.uamserver_arg) {
     syslog(LOG_ERR, "WARNING: No uamserver defiend!");
   }

src/options.c

@@ -306,6 +306,8 @@ int options_fromfd(int fd, bstring bt) {
   if (!option_s_l(bt, &o.routeif)) return 0;
   if (!option_s_l(bt, &o.peerkey)) return 0;
 
+  if (!option_s_l(bt, &o.rfc7710uri)) return 0;
+
   if (!option_s_l(bt, &o.macsuffix)) return 0;
   if (!option_s_l(bt, &o.macpasswd)) return 0;
 
@@ -507,6 +509,8 @@ int options_save(char *file, bstring bt) {
   if (!option_s_s(bt, &o.routeif)) return 0;
   if (!option_s_s(bt, &o.peerkey)) return 0;
 
+  if (!option_s_s(bt, &o.rfc7710uri)) return 0;
+
   if (!option_s_s(bt, &o.macsuffix)) return 0;
   if (!option_s_s(bt, &o.macpasswd)) return 0;
 

src/options.h

@@ -322,6 +322,8 @@ struct options_t {
   uint32_t ipsrc_num_pass_throughs;
 #endif
 
+  char* rfc7710uri; /* RFC 7710 URI, nullptr if not used. */
+
   char* uamdomains[MAX_UAM_DOMAINS];
   int uamdomain_ttl;