WPS ER: Use random event identifier in event URL

This avoids some issues in cases where the ER has been started and
stopped multiple times on the same address and an AP may have stored
multiple event notification addresses for the same ER. The random
identifier allows the ER to filter out unexpected messages from further
processing.

diff --git a/src/wps/wps_er.c b/src/wps/wps_er.c
index 3c94bec351fac0bd36efd8638d819df606ce1001..bedd60ace680f9494eb77f1fe9ee705ea1910ccf 100644 (file)
--- a/src/wps/wps_er.c
+++ b/src/wps/wps_er.c
@@ -293,12 +293,13 @@ static void wps_er_subscribe(struct wps_er_ap *ap)
        wpabuf_printf(req,
                      "SUBSCRIBE %s HTTP/1.1\r\n"
                      "HOST: %s:%d\r\n"
-                     "CALLBACK: <http://%s:%d/event/%d>\r\n"
+                     "CALLBACK: <http://%s:%d/event/%u/%u>\r\n"
                      "NT: upnp:event\r\n"
                      "TIMEOUT: Second-%d\r\n"
                      "\r\n",
                      path, inet_ntoa(dst.sin_addr), ntohs(dst.sin_port),
-                     ap->er->ip_addr_text, ap->er->http_port, ap->id, 1800);
+                     ap->er->ip_addr_text, ap->er->http_port,
+                     ap->er->event_id, ap->id, 1800);
        os_free(url);
        wpa_hexdump_ascii(MSG_MSGDUMP, "WPS ER: Subscription request",
                          wpabuf_head(req), wpabuf_len(req));
@@ -981,7 +982,19 @@ static void wps_er_http_notify(struct wps_er *er, struct http_request *req)
        char *uri = http_request_get_uri(req);
 
        if (os_strncmp(uri, "/event/", 7) == 0) {
-               wps_er_http_event(er, req, atoi(uri + 7));
+               unsigned int event_id;
+               char *pos;
+               event_id = atoi(uri + 7);
+               if (event_id != er->event_id) {
+                       wpa_printf(MSG_DEBUG, "WPS ER: HTTP event for an "
+                                  "unknown event id %u", event_id);
+                       return;
+               }
+               pos = os_strchr(uri + 7, '/');
+               if (pos == NULL)
+                       return;
+               pos++;
+               wps_er_http_event(er, req, atoi(pos));
        } else {
                wpa_printf(MSG_DEBUG, "WPS ER: Unknown HTTP NOTIFY for '%s'",
                           uri);
@@ -1040,6 +1053,7 @@ wps_er_init(struct wps_context *wps, const char *ifname)
 
        os_strlcpy(er->ifname, ifname, sizeof(er->ifname));
        er->wps = wps;
+       os_get_random((unsigned char *) &er->event_id, sizeof(er->event_id));
 
        if (get_netif_info(ifname,
                           &er->ip_addr, &er->ip_addr_text,

diff --git a/src/wps/wps_er.h b/src/wps/wps_er.h
index cf2048c8bea8f1b181c54159064c1a906b19b571..8f502d2b483dc1193bc3a9a59b02c614bec0cd5d 100644 (file)
--- a/src/wps/wps_er.h
+++ b/src/wps/wps_er.h
@@ -68,6 +68,7 @@ struct wps_er {
        struct http_server *http_srv;
        int http_port;
        unsigned int next_ap_id;
+       unsigned int event_id;
 };