Do not run multiple instances of empathy. Fixes bug #501805 (Marco Barisione).

svn path=/trunk/; revision=711

1 files changed, 396 insertions, 0 deletions

diff --git a/src/bacon-message-connection.c b/src/bacon-message-connection.c
new file mode 100644
index 000000000..c8000de24
--- /dev/null
+++ b/src/bacon-message-connection.c
@@ -0,0 +1,396 @@
+/*
+ * Copyright (C) 2003 Bastien Nocera <hadess@hadess.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <errno.h>
+
+#include "bacon-message-connection.h"
+
+#ifndef UNIX_PATH_MAX
+#define UNIX_PATH_MAX 108
+#endif
+
+struct BaconMessageConnection {
+	/* A server accepts connections */
+	gboolean is_server;
+
+	/* The socket path itself */
+	char *path;
+
+	/* File descriptor of the socket */
+	int fd;
+	/* Channel to watch */
+	GIOChannel *chan;
+	/* Event id returned by g_io_add_watch() */
+	int conn_id;
+
+	/* Connections accepted by this connection */
+	GSList *accepted_connections;
+
+	/* callback */
+	void (*func) (const char *message, gpointer user_data);
+	gpointer data;
+};
+
+static gboolean
+test_is_socket (const char *path)
+{
+	struct stat s;
+
+	if (stat (path, &s) == -1)
+		return FALSE;
+
+	if (S_ISSOCK (s.st_mode))
+		return TRUE;
+
+	return FALSE;
+}
+
+static gboolean
+is_owned_by_user_and_socket (const char *path)
+{
+	struct stat s;
+
+	if (stat (path, &s) == -1)
+		return FALSE;
+
+	if (s.st_uid != geteuid ())
+		return FALSE;
+
+	if ((s.st_mode & S_IFSOCK) != S_IFSOCK)
+		return FALSE;
+	
+	return TRUE;
+}
+
+static gboolean server_cb (GIOChannel *source,
+			   GIOCondition condition, gpointer data);
+
+static gboolean
+setup_connection (BaconMessageConnection *conn)
+{
+	g_return_val_if_fail (conn->chan == NULL, FALSE);
+
+	conn->chan = g_io_channel_unix_new (conn->fd);
+	if (!conn->chan) {
+		return FALSE;
+	}
+	g_io_channel_set_line_term (conn->chan, "\n", 1);
+	conn->conn_id = g_io_add_watch (conn->chan, G_IO_IN, server_cb, conn);
+
+	return TRUE;
+}
+
+static void
+accept_new_connection (BaconMessageConnection *server_conn)
+{
+	BaconMessageConnection *conn;
+	int alen;
+
+	g_return_if_fail (server_conn->is_server);
+
+	conn = g_new0 (BaconMessageConnection, 1);
+	conn->is_server = FALSE;
+	conn->func = server_conn->func;
+	conn->data = server_conn->data;
+
+	conn->fd = accept (server_conn->fd, NULL, (guint *)&alen);
+
+	server_conn->accepted_connections =
+		g_slist_prepend (server_conn->accepted_connections, conn);
+
+	setup_connection (conn);
+}
+
+static gboolean
+server_cb (GIOChannel *source, GIOCondition condition, gpointer data)
+{
+	BaconMessageConnection *conn = (BaconMessageConnection *)data;
+	char *message, *subs, buf;
+	int cd, rc, offset;
+	gboolean finished;
+
+	offset = 0;
+	if (conn->is_server && conn->fd == g_io_channel_unix_get_fd (source)) {
+		accept_new_connection (conn);
+		return TRUE;
+	}
+	message = g_malloc (1);
+	cd = conn->fd;
+	rc = read (cd, &buf, 1);
+	while (rc > 0 && buf != '\n')
+	{
+		message = g_realloc (message, rc + offset + 1);
+		message[offset] = buf;
+		offset = offset + rc;
+		rc = read (cd, &buf, 1);
+	}
+	if (rc <= 0) {
+		g_io_channel_shutdown (conn->chan, FALSE, NULL);
+		g_io_channel_unref (conn->chan);
+		conn->chan = NULL;
+		close (conn->fd);
+		conn->fd = -1;
+		g_free (message);
+		conn->conn_id = 0;
+
+		return FALSE;
+	}
+	message[offset] = '\0';
+
+	subs = message;
+	finished = FALSE;
+
+	while (finished == FALSE && *subs != '\0')
+	{
+		if (conn->func != NULL)
+			(*conn->func) (subs, conn->data);
+
+		subs += strlen (subs) + 1;
+		if (subs - message >= offset)
+			finished = TRUE;
+	}
+
+	g_free (message);
+
+	return TRUE;
+}
+
+static char *
+find_file_with_pattern (const char *dir, const char *pattern)
+{
+	GDir *filedir;
+	char *found_filename;
+	const char *filename;
+	GPatternSpec *pat;
+
+	filedir = g_dir_open (dir, 0, NULL);
+	if (filedir == NULL)
+		return NULL;
+
+	pat = g_pattern_spec_new (pattern);
+	if (pat == NULL)
+	{
+		g_dir_close (filedir);
+		return NULL;
+	}
+
+	found_filename = NULL;
+
+	while ((filename = g_dir_read_name (filedir)))
+	{
+		if (g_pattern_match_string (pat, filename))
+		{
+			char *tmp = g_build_filename (dir, filename, NULL);
+			if (is_owned_by_user_and_socket (tmp))
+				found_filename = g_strdup (filename);
+			g_free (tmp);
+		}
+
+		if (found_filename != NULL)
+			break;
+	}
+
+	g_pattern_spec_free (pat);
+	g_dir_close (filedir);
+
+	return found_filename;
+}
+
+static char *
+socket_filename (const char *prefix)
+{
+	char *pattern, *newfile, *path, *filename;
+	const char *tmpdir;
+
+	pattern = g_strdup_printf ("%s.%s.*", prefix, g_get_user_name ());
+	tmpdir = g_get_tmp_dir ();
+	filename = find_file_with_pattern (tmpdir, pattern);
+	if (filename == NULL)
+	{
+		newfile = g_strdup_printf ("%s.%s.%u", prefix,
+				g_get_user_name (), g_random_int ());
+		path = g_build_filename (tmpdir, newfile, NULL);
+		g_free (newfile);
+	} else {
+		path = g_build_filename (tmpdir, filename, NULL);
+		g_free (filename);
+	}
+
+	g_free (pattern);
+	return path;
+}
+
+static gboolean
+try_server (BaconMessageConnection *conn)
+{
+	struct sockaddr_un uaddr;
+
+	uaddr.sun_family = AF_UNIX;
+	strncpy (uaddr.sun_path, conn->path,
+			MIN (strlen(conn->path)+1, UNIX_PATH_MAX));
+	conn->fd = socket (PF_UNIX, SOCK_STREAM, 0);
+	if (bind (conn->fd, (struct sockaddr *) &uaddr, sizeof (uaddr)) == -1)
+	{
+		conn->fd = -1;
+		return FALSE;
+	}
+	listen (conn->fd, 5);
+
+	if (!setup_connection (conn))
+		return FALSE;
+	return TRUE;
+}
+
+static gboolean
+try_client (BaconMessageConnection *conn)
+{
+	struct sockaddr_un uaddr;
+
+	uaddr.sun_family = AF_UNIX;
+	strncpy (uaddr.sun_path, conn->path,
+			MIN(strlen(conn->path)+1, UNIX_PATH_MAX));
+	conn->fd = socket (PF_UNIX, SOCK_STREAM, 0);
+	if (connect (conn->fd, (struct sockaddr *) &uaddr,
+				sizeof (uaddr)) == -1)
+	{
+		conn->fd = -1;
+		return FALSE;
+	}
+
+	return setup_connection (conn);
+}
+
+BaconMessageConnection *
+bacon_message_connection_new (const char *prefix)
+{
+	BaconMessageConnection *conn;
+
+	g_return_val_if_fail (prefix != NULL, NULL);
+
+	conn = g_new0 (BaconMessageConnection, 1);
+	conn->path = socket_filename (prefix);
+
+	if (test_is_socket (conn->path) == FALSE)
+	{
+		if (!try_server (conn))
+		{
+			bacon_message_connection_free (conn);
+			return NULL;
+		}
+
+		conn->is_server = TRUE;
+		return conn;
+	}
+
+	if (try_client (conn) == FALSE)
+	{
+		unlink (conn->path);
+		try_server (conn);
+		if (conn->fd == -1)
+		{
+			bacon_message_connection_free (conn);
+			return NULL;
+		}
+
+		conn->is_server = TRUE;
+		return conn;
+	}
+
+	conn->is_server = FALSE;
+	return conn;
+}
+
+void
+bacon_message_connection_free (BaconMessageConnection *conn)
+{
+	GSList *child_conn;
+
+	g_return_if_fail (conn != NULL);
+	/* Only servers can accept other connections */
+	g_return_if_fail (conn->is_server != FALSE ||
+			  conn->accepted_connections == NULL);
+
+	child_conn = conn->accepted_connections;
+	while (child_conn != NULL) {
+		bacon_message_connection_free (child_conn->data);
+		child_conn = g_slist_next (child_conn);
+	}
+	g_slist_free (conn->accepted_connections);
+
+	if (conn->conn_id) {
+		g_source_remove (conn->conn_id);
+		conn->conn_id = 0;
+	}
+	if (conn->chan) {
+		g_io_channel_shutdown (conn->chan, FALSE, NULL);
+		g_io_channel_unref (conn->chan);
+	}
+
+	if (conn->is_server != FALSE) {
+		unlink (conn->path);
+	}
+	if (conn->fd != -1) {
+		close (conn->fd);
+	}
+
+	g_free (conn->path);
+	g_free (conn);
+}
+
+void
+bacon_message_connection_set_callback (BaconMessageConnection *conn,
+				       BaconMessageReceivedFunc func,
+				       gpointer user_data)
+{
+	g_return_if_fail (conn != NULL);
+
+	conn->func = func;
+	conn->data = user_data;
+}
+
+void
+bacon_message_connection_send (BaconMessageConnection *conn,
+			       const char *message)
+{
+	g_return_if_fail (conn != NULL);
+	g_return_if_fail (message != NULL);
+
+	g_io_channel_write_chars (conn->chan, message, strlen (message),
+				  NULL, NULL);
+	g_io_channel_write_chars (conn->chan, "\n", 1, NULL, NULL);
+	g_io_channel_flush (conn->chan, NULL);
+}
+
+gboolean
+bacon_message_connection_get_is_server (BaconMessageConnection *conn)
+{
+	g_return_val_if_fail (conn != NULL, FALSE);
+
+	return conn->is_server;
+}
+