agent: Support adding optional headers to HTTP proxy client

One use case for this is adding an ALPN header which is a MUST
requirement when a HTTP proxy is used in WebRTC (see RFC8835, section
3.4).

4 files changed, 76 insertions, 17 deletions

diff --git a/agent/agent-priv.h b/agent/agent-priv.h
index 1d8b683..35ae5ab 100644
--- a/agent/agent-priv.h
+++ b/agent/agent-priv.h
@@ -140,6 +140,7 @@ struct _NiceAgent
   NiceProxyType proxy_type;       /* property: Proxy type */
   gchar *proxy_username;          /* property: Proxy username */
   gchar *proxy_password;          /* property: Proxy password */
+  GHashTable *proxy_extra_headers;/* property: Proxy extra headers */
   gboolean saved_controlling_mode;/* property: controlling-mode */
   guint timer_ta;                 /* property: timer Ta */
   guint max_conn_checks;          /* property: max connectivity checks */
diff --git a/agent/agent.c b/agent/agent.c
index a2e150f..6278fa7 100644
--- a/agent/agent.c
+++ b/agent/agent.c
@@ -112,6 +112,7 @@ enum
   PROP_PROXY_PORT,
   PROP_PROXY_USERNAME,
   PROP_PROXY_PASSWORD,
+  PROP_PROXY_EXTRA_HEADERS,
   PROP_UPNP,
   PROP_UPNP_TIMEOUT,
   PROP_RELIABLE,
@@ -615,6 +616,23 @@ nice_agent_class_init (NiceAgentClass *klass)
         G_PARAM_READWRITE));
 
   /**
+   * NiceAgent:proxy-extra-headers: (type GLib.HashTable(utf8,utf8))
+   *
+   * Optional extra headers to append to the HTTP proxy CONNECT request.
+   * Provided as key/value-pairs in hash table corresponding to
+   * header-name/header-value.
+   *
+   * Since: 0.1.20
+   */
+  g_object_class_install_property (gobject_class, PROP_PROXY_EXTRA_HEADERS,
+      g_param_spec_boxed (
+        "proxy-extra-headers",
+        "Extra headers for HTTP proxy connect",
+        "Extra headers to append to the HTTP proxy CONNECT request",
+        G_TYPE_HASH_TABLE,
+        G_PARAM_READWRITE));
+
+  /**
    * NiceAgent:upnp:
    *
    * Whether the agent should use UPnP to open a port in the router and
@@ -1427,6 +1445,10 @@ nice_agent_get_property (
       g_value_set_string (value, agent->proxy_password);
       break;
 
+    case PROP_PROXY_EXTRA_HEADERS:
+      g_value_set_boxed (value, agent->proxy_extra_headers);
+      break;
+
     case PROP_UPNP:
 #ifdef HAVE_GUPNP
       g_value_set_boolean (value, agent->upnp_enabled);
@@ -1564,6 +1586,12 @@ nice_agent_reset_all_stun_agents (NiceAgent *agent, gboolean only_software)
 }
 
 static void
+copy_hash_entry (const gchar *key, const gchar *value, GHashTable *hdest)
+{
+    g_hash_table_insert (hdest, g_strdup (key), g_strdup (value));
+}
+
+static void
 nice_agent_set_property (
   GObject *object,
   guint property_id,
@@ -1652,6 +1680,17 @@ nice_agent_set_property (
       agent->proxy_password = g_value_dup_string (value);
       break;
 
+    case PROP_PROXY_EXTRA_HEADERS:{
+      GHashTable *h = g_value_get_boxed (value);
+      if (agent->proxy_extra_headers) {
+        g_hash_table_unref (agent->proxy_extra_headers);
+      }
+      agent->proxy_extra_headers = g_hash_table_new_full (g_str_hash,
+          g_str_equal, g_free, g_free);
+      g_hash_table_foreach (h, (GHFunc)copy_hash_entry,
+          agent->proxy_extra_headers);
+      break;
+    }
     case PROP_UPNP_TIMEOUT:
 #ifdef HAVE_GUPNP
       agent->upnp_timeout = g_value_get_uint (value);
@@ -2673,7 +2712,8 @@ agent_create_tcp_turn_socket (NiceAgent *agent, NiceStream *stream,
             agent->proxy_username, agent->proxy_password);
       } else if (agent->proxy_type == NICE_PROXY_TYPE_HTTP){
         nicesock = nice_http_socket_new (nicesock, server,
-            agent->proxy_username, agent->proxy_password);
+            agent->proxy_username, agent->proxy_password,
+            agent->proxy_extra_headers);
       } else {
         nice_socket_free (nicesock);
         nicesock = NULL;
@@ -5761,7 +5801,10 @@ nice_agent_dispose (GObject *object)
   agent->proxy_username = NULL;
   g_free (agent->proxy_password);
   agent->proxy_password = NULL;
-
+  if (agent->proxy_extra_headers != NULL) {
+    g_hash_table_unref (agent->proxy_extra_headers);
+    agent->proxy_extra_headers = NULL;
+  }
   nice_rng_free (agent->rng);
   agent->rng = NULL;
 
diff --git a/socket/http.c b/socket/http.c
index 96ddfd8..d16b317 100644
--- a/socket/http.c
+++ b/socket/http.c
@@ -97,9 +97,17 @@ static void socket_set_writable_callback (NiceSocket *sock,
     NiceSocketWritableCb callback, gpointer user_data);
 static gboolean socket_is_based_on (NiceSocket *sock, NiceSocket *other);
 
+static void
+_append_extra_header (gpointer key, gpointer value, gpointer user_data)
+{
+  GString *str = user_data;
+  g_string_append_printf (str, "%s: %s\r\n", (gchar *)key, (gchar *)value);
+}
+
 NiceSocket *
 nice_http_socket_new (NiceSocket *base_socket,
-    NiceAddress *addr, gchar *username, gchar *password)
+    NiceAddress *addr, gchar *username, gchar *password,
+    GHashTable *extra_headers)
 {
   HttpPriv *priv;
   NiceSocket *sock = NULL;
@@ -133,7 +141,7 @@ nice_http_socket_new (NiceSocket *base_socket,
     /* Send HTTP CONNECT */
     {
       gchar *msg = NULL;
-      gchar *credential = NULL;
+      GString *str = NULL;
       gchar host[INET6_ADDRSTRLEN];
       gint port = nice_address_get_port (&priv->addr);
       GOutputVector local_bufs;
@@ -141,25 +149,31 @@ nice_http_socket_new (NiceSocket *base_socket,
 
       nice_address_to_string (&priv->addr, host);
 
+      str = g_string_new (NULL);
+      g_string_printf (str, "CONNECT %s:%d HTTP/1.0\r\n"
+          "Host: %s\r\n"
+          "User-Agent: %s\r\n"
+          "Content-Length: 0\r\n"
+          "Proxy-Connection: Keep-Alive\r\n"
+          "Connection: Keep-Alive\r\n"
+          "Cache-Control: no-cache\r\n"
+          "Pragma: no-cache\r\n",
+          host, port, host, HTTP_USER_AGENT);
+
+      if (extra_headers) {
+        g_hash_table_foreach (extra_headers, _append_extra_header, str);
+      }
+
       if (username) {
         gchar * userpass = g_strdup_printf ("%s:%s", username,
             password ? password : "");
         gchar * auth = g_base64_encode ((guchar *)userpass, strlen (userpass));
-        credential = g_strdup_printf ("Proxy-Authorization: Basic %s\r\n", auth);
+        g_string_append_printf (str, "Proxy-Authorization: Basic %s\r\n", auth);
         g_free (auth);
         g_free (userpass);
       }
-      msg = g_strdup_printf ("CONNECT %s:%d HTTP/1.0\r\n"
-          "Host: %s\r\n"
-          "User-Agent: %s\r\n"
-          "Content-Length: 0\r\n"
-          "Proxy-Connection: Keep-Alive\r\n"
-          "Connection: Keep-Alive\r\n"
-          "Cache-Control: no-cache\r\n"
-          "Pragma: no-cache\r\n"
-          "%s\r\n", host, port, host, HTTP_USER_AGENT,
-          credential? credential : "" );
-      g_free (credential);
+      g_string_append_printf (str, "\r\n");
+      msg = g_string_free (str, FALSE);
 
       local_bufs.buffer = msg;
       local_bufs.size = strlen (msg);
diff --git a/socket/http.h b/socket/http.h
index 7f095a0..b2df362 100644
--- a/socket/http.h
+++ b/socket/http.h
@@ -45,7 +45,8 @@ G_BEGIN_DECLS
 
 NiceSocket *
 nice_http_socket_new (NiceSocket *base_socket,
-    NiceAddress *addr, gchar *username, gchar *password);
+    NiceAddress *addr, gchar *username, gchar *password,
+    GHashTable *extra_headers);
 
 
 G_END_DECLS