[libsoup/wip/server-steal: 9/9] soup-server: add soup_client_context_steal_connection()

[Dan Winship <danw src gnome org>]

commit aa4a885388d6aca0fe9302bfa257d91777087bdf
Author: Dan Winship <danw gnome org>
Date:   Sun Jan 19 10:48:56 2014 -0500

    soup-server: add soup_client_context_steal_connection()
    
    Add a method to allow a SoupServer handler to steal the connection
    from the server, and use this in simple-proxy to implement CONNECT.

 docs/reference/libsoup-2.4-sections.txt |    1 +
 examples/simple-proxy.c                 |  213 ++++++++++++++++++++++++++++++-
 libsoup/libsoup-2.4.sym                 |    1 +
 libsoup/soup-message-server-io.c        |   28 ++++-
 libsoup/soup-server.c                   |   44 ++++++-
 libsoup/soup-server.h                   |    2 +
 6 files changed, 284 insertions(+), 5 deletions(-)
---
diff --git a/docs/reference/libsoup-2.4-sections.txt b/docs/reference/libsoup-2.4-sections.txt
index 11f650f..805a391 100644
--- a/docs/reference/libsoup-2.4-sections.txt
+++ b/docs/reference/libsoup-2.4-sections.txt
@@ -238,6 +238,7 @@ soup_client_context_get_host
 soup_client_context_get_auth_domain
 soup_client_context_get_auth_user
 soup_client_context_get_gsocket
+soup_client_context_steal_connection
 <SUBSECTION>
 soup_server_add_auth_domain
 soup_server_remove_auth_domain
diff --git a/examples/simple-proxy.c b/examples/simple-proxy.c
index 08bd847..7657355 100644
--- a/examples/simple-proxy.c
+++ b/examples/simple-proxy.c
@@ -15,6 +15,217 @@
 static SoupSession *session;
 static SoupServer *server;
 
+typedef struct {
+       GIOStream *iostream;
+       GInputStream *istream;
+       GOutputStream *ostream;
+
+       gssize nread, nwrote;
+       guchar *buffer;
+} TunnelEnd;
+
+typedef struct {
+       SoupServer *self;
+       SoupMessage *msg;
+       SoupClientContext *context;
+       GCancellable *cancellable;
+
+       TunnelEnd client, server;
+} Tunnel;
+
+#define BUFSIZE 8192
+
+static void tunnel_read_cb (GObject      *object,
+                           GAsyncResult *result,
+                           gpointer      user_data);
+
+static void
+tunnel_close (Tunnel *tunnel)
+{
+       if (tunnel->cancellable) {
+               g_cancellable_cancel (tunnel->cancellable);
+               g_object_unref (tunnel->cancellable);
+       }
+
+       if (tunnel->client.iostream) {
+               g_io_stream_close (tunnel->client.iostream, NULL, NULL);
+               g_object_unref (tunnel->client.iostream);
+       }
+       if (tunnel->server.iostream) {
+               g_io_stream_close (tunnel->server.iostream, NULL, NULL);
+               g_object_unref (tunnel->server.iostream);
+       }
+
+       g_free (tunnel->client.buffer);
+       g_free (tunnel->server.buffer);
+
+       g_object_unref (tunnel->self);
+       g_object_unref (tunnel->msg);
+
+       g_free (tunnel);
+}
+
+static void
+tunnel_wrote_cb (GObject      *object,
+                GAsyncResult *result,
+                gpointer      user_data)
+{
+       Tunnel *tunnel = user_data;
+       TunnelEnd *write_end, *read_end;
+       GError *error = NULL;
+       gssize nwrote;
+
+       nwrote = g_output_stream_write_finish (G_OUTPUT_STREAM (object), result, &error);
+       if (nwrote <= 0) {
+               if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+                       g_error_free (error);
+                       return;
+               } else if (error) {
+                       g_print ("Tunnel write failed: %s\n", error->message);
+                       g_error_free (error);
+               }
+               tunnel_close (tunnel);
+               return;
+       }
+
+       if (object == (GObject *)tunnel->client.ostream) {
+               write_end = &tunnel->client;
+               read_end = &tunnel->server;
+       } else {
+               write_end = &tunnel->server;
+               read_end = &tunnel->client;
+       }
+
+       write_end->nwrote += nwrote;
+       if (write_end->nwrote < read_end->nread) {
+               g_output_stream_write_async (write_end->ostream,
+                                            read_end->buffer + write_end->nwrote,
+                                            read_end->nread - write_end->nwrote,
+                                            G_PRIORITY_DEFAULT, tunnel->cancellable,
+                                            tunnel_wrote_cb, tunnel);
+       } else {
+               g_input_stream_read_async (read_end->istream,
+                                          read_end->buffer, BUFSIZE,
+                                          G_PRIORITY_DEFAULT, tunnel->cancellable,
+                                          tunnel_read_cb, tunnel);
+       }
+}
+
+static void
+tunnel_read_cb (GObject      *object,
+               GAsyncResult *result,
+               gpointer      user_data)
+{
+       Tunnel *tunnel = user_data;
+       TunnelEnd *read_end, *write_end;
+       GError *error = NULL;
+       gssize nread;
+
+       nread = g_input_stream_read_finish (G_INPUT_STREAM (object), result, &error);
+       if (nread <= 0) {
+               if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+                       g_error_free (error);
+                       return;
+               } else if (error) {
+                       g_print ("Tunnel read failed: %s\n", error->message);
+                       g_error_free (error);
+               }
+               tunnel_close (tunnel);
+               return;
+       }
+
+       if (object == (GObject *)tunnel->client.istream) {
+               read_end = &tunnel->client;
+               write_end = &tunnel->server;
+       } else {
+               read_end = &tunnel->server;
+               write_end = &tunnel->client;
+       }
+
+       read_end->nread = nread;
+       write_end->nwrote = 0;
+       g_output_stream_write_async (write_end->ostream,
+                                    read_end->buffer, read_end->nread,
+                                    G_PRIORITY_DEFAULT, tunnel->cancellable,
+                                    tunnel_wrote_cb, tunnel);
+}
+
+static void
+start_tunnel (SoupMessage *msg, gpointer user_data)
+{
+       Tunnel *tunnel = user_data;
+
+       tunnel->client.iostream = soup_client_context_steal_connection (tunnel->context);
+       tunnel->client.istream = g_io_stream_get_input_stream (tunnel->client.iostream);
+       tunnel->client.ostream = g_io_stream_get_output_stream (tunnel->client.iostream);
+
+       tunnel->client.buffer = g_malloc (BUFSIZE);
+       tunnel->server.buffer = g_malloc (BUFSIZE);
+
+       tunnel->cancellable = g_cancellable_new ();
+
+       g_input_stream_read_async (tunnel->client.istream,
+                                  tunnel->client.buffer, BUFSIZE,
+                                  G_PRIORITY_DEFAULT, tunnel->cancellable,
+                                  tunnel_read_cb, tunnel);
+       g_input_stream_read_async (tunnel->server.istream,
+                                  tunnel->server.buffer, BUFSIZE,
+                                  G_PRIORITY_DEFAULT, tunnel->cancellable,
+                                  tunnel_read_cb, tunnel);
+}
+
+
+static void
+tunnel_connected_cb (GObject      *object,
+                    GAsyncResult *result,
+                    gpointer      user_data)
+{
+       Tunnel *tunnel = user_data;
+       GError *error = NULL;
+
+       tunnel->server.iostream = (GIOStream *)
+               g_socket_client_connect_to_host_finish (G_SOCKET_CLIENT (object), result, &error);
+       if (!tunnel->server.iostream) {
+               soup_message_set_status (tunnel->msg, SOUP_STATUS_BAD_GATEWAY);
+               soup_message_set_response (tunnel->msg, "text/plain",
+                                          SOUP_MEMORY_COPY,
+                                          error->message, strlen (error->message));
+               g_error_free (error);
+               soup_server_unpause_message (tunnel->self, tunnel->msg);
+               tunnel_close (tunnel);
+               return;
+       }
+
+       tunnel->server.istream = g_io_stream_get_input_stream (tunnel->server.iostream);
+       tunnel->server.ostream = g_io_stream_get_output_stream (tunnel->server.iostream);
+
+       soup_message_set_status (tunnel->msg, SOUP_STATUS_OK);
+       soup_server_unpause_message (tunnel->self, tunnel->msg);
+       g_signal_connect (tunnel->msg, "finished",
+                         G_CALLBACK (start_tunnel), tunnel);
+}
+
+static void
+try_tunnel (SoupServer *server, SoupMessage *msg, SoupClientContext *context)
+{
+       Tunnel *tunnel;
+       SoupURI *dest_uri;
+       GSocketClient *sclient;
+
+       soup_server_pause_message (server, msg);
+
+       tunnel = g_new0 (Tunnel, 1);
+       tunnel->self = g_object_ref (server);
+       tunnel->msg = g_object_ref (msg);
+       tunnel->context = context;
+
+       dest_uri = soup_message_get_uri (msg);
+       sclient = g_socket_client_new ();
+       g_socket_client_connect_to_host_async (sclient, dest_uri->host, dest_uri->port,
+                                              NULL, tunnel_connected_cb, tunnel);
+       g_object_unref (sclient);
+}
+
 static void
 copy_header (const char *name, const char *value, gpointer dest_headers)
 {
@@ -78,7 +289,7 @@ server_callback (SoupServer *server, SoupMessage *msg,
                 soup_message_get_http_version (msg));
 
        if (msg->method == SOUP_METHOD_CONNECT) {
-               soup_message_set_status (msg, SOUP_STATUS_NOT_IMPLEMENTED);
+               try_tunnel (server, msg, context);
                return;
        }
 
diff --git a/libsoup/libsoup-2.4.sym b/libsoup/libsoup-2.4.sym
index d1b8388..908c26b 100644
--- a/libsoup/libsoup-2.4.sym
+++ b/libsoup/libsoup-2.4.sym
@@ -93,6 +93,7 @@ soup_client_context_get_local_address
 soup_client_context_get_remote_address
 soup_client_context_get_socket
 soup_client_context_get_type
+soup_client_context_steal_connection
 soup_connection_state_get_type
 soup_content_decoder_get_type
 soup_content_sniffer_get_buffer_size
diff --git a/libsoup/soup-message-server-io.c b/libsoup/soup-message-server-io.c
index 00272f3..cd8edde 100644
--- a/libsoup/soup-message-server-io.c
+++ b/libsoup/soup-message-server-io.c
@@ -9,6 +9,7 @@
 #include "config.h"
 #endif
 
+#include <stdlib.h>
 #include <string.h>
 
 #include <glib/gi18n-lib.h>
@@ -18,6 +19,28 @@
 #include "soup-misc-private.h"
 #include "soup-socket-private.h"
 
+static SoupURI *
+parse_connect_authority (const char *req_path)
+{
+       SoupURI *uri;
+       char *fake_uri;
+
+       fake_uri = g_strdup_printf ("http://%s";, req_path);
+       uri = soup_uri_new (fake_uri);
+       g_free (fake_uri);
+
+       if (uri->user || uri->password ||
+           uri->query || uri->fragment ||
+           !uri->host ||
+           (uri->port == 0) ||
+           (strcmp (uri->path, "/") != 0)) {
+               soup_uri_free (uri);
+               return NULL;
+       }
+
+       return uri;
+}
+
 static guint
 parse_request_headers (SoupMessage *msg, char *headers, guint headers_len,
                       SoupEncoding *encoding, gpointer sock, GError **error)
@@ -74,8 +97,11 @@ parse_request_headers (SoupMessage *msg, char *headers, guint headers_len,
                if (uri)
                        soup_uri_set_path (uri, "*");
                g_free (url);
+       } else if (msg->method == SOUP_METHOD_CONNECT) {
+               /* Authority */
+               uri = parse_connect_authority (req_path);
        } else if (*req_path != '/') {
-               /* Must be an absolute URI */
+               /* Absolute URI */
                uri = soup_uri_new (req_path);
        } else if (req_host) {
                url = g_strdup_printf ("%s://%s%s",
diff --git a/libsoup/soup-server.c b/libsoup/soup-server.c
index a947077..065c7fe 100644
--- a/libsoup/soup-server.c
+++ b/libsoup/soup-server.c
@@ -99,6 +99,7 @@ struct SoupClientContext {
        GSocketAddress *local_addr;
 
        int             ref_count;
+       gboolean        stole_connection;
 };
 
 typedef struct {
@@ -1136,8 +1137,15 @@ request_finished (SoupMessage *msg, gboolean io_complete, gpointer user_data)
                       0, msg, client);
 
        soup_client_context_cleanup (client);
-       if (io_complete && soup_socket_is_connected (sock) &&
-           soup_message_is_keepalive (msg)) {
+
+       if (client->stole_connection) {
+               g_object_set (G_OBJECT (sock),
+                             SOUP_SOCKET_CLOSE_ON_DISPOSE, FALSE,
+                             NULL);
+               soup_client_context_unref (client);
+       } else if (io_complete &&
+                  soup_socket_is_connected (sock) &&
+                  soup_message_is_keepalive (msg)) {
                /* Start a new request */
                start_request (server, client);
        } else {
@@ -2161,6 +2169,37 @@ soup_client_context_get_auth_user (SoupClientContext *client)
 }
 
 /**
+ * soup_client_context_steal_connection:
+ * @client: a #SoupClientContext
+ *
+ * "Steals" the HTTP connection associated with @client from its
+ * #SoupServer. Note that this happens immediately, regardless of the
+ * current state of the connection; if the response to the current
+ * #SoupMessage has not yet finished being sent, then it will be
+ * discarded; you can steal the connection from a
+ * #SoupMessage:finished or #SoupServer:request-finished handler
+ * if you want to wait for the response to be sent.
+ *
+ * Return value: the #GIOStream connected to @client. No guarantees
+ *   are made about what kind of #GIOStream this is.
+ *
+ * Since: 2.46
+ **/
+GIOStream *
+soup_client_context_steal_connection (SoupClientContext *client)
+{
+       g_return_val_if_fail (client != NULL, NULL);
+       g_return_val_if_fail (client->stole_connection == FALSE, NULL);
+
+       client->stole_connection = TRUE;
+
+       if (soup_message_io_in_progress (client->msg))
+               soup_message_io_finished (client->msg);
+
+       return soup_socket_get_iostream (client->sock);
+}
+
+/**
  * SoupServerCallback:
  * @server: the #SoupServer
  * @msg: the message being processed
@@ -2405,4 +2444,3 @@ soup_server_unpause_message (SoupServer *server,
 
        soup_message_io_unpause (msg);
 }
-
diff --git a/libsoup/soup-server.h b/libsoup/soup-server.h
index a79673f..c751471 100644
--- a/libsoup/soup-server.h
+++ b/libsoup/soup-server.h
@@ -145,6 +145,8 @@ const char     *soup_client_context_get_host           (SoupClientContext *clien
 SoupAuthDomain *soup_client_context_get_auth_domain    (SoupClientContext *client);
 const char     *soup_client_context_get_auth_user      (SoupClientContext *client);
 
+SOUP_AVAILABLE_IN_2_46
+GIOStream      *soup_client_context_steal_connection   (SoupClientContext *client);
 
 /* Legacy API */