sugar-toolkit-gtk3/src/sugar/gsm-xsmp.c

536 lines
15 KiB
C

/* xsmp.c
* Copyright (C) 2007 Novell, Inc.
*
* 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
* Lesser 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <glib.h>
#include <glib/gi18n.h>
#include "gsm-client-xsmp.h"
#include "gsm-xsmp.h"
#include <X11/ICE/ICElib.h>
#include <X11/ICE/ICEutil.h>
#include <X11/ICE/ICEconn.h>
#include <X11/SM/SMlib.h>
#ifdef HAVE_X11_XTRANS_XTRANS_H
/* Get the proto for _IceTransNoListen */
#define ICE_t
#define TRANS_SERVER
#include <X11/Xtrans/Xtrans.h>
#undef ICE_t
#undef TRANS_SERVER
#endif /* HAVE_X11_XTRANS_XTRANS_H */
static IceListenObj *xsmp_sockets;
static int num_xsmp_sockets, num_local_xsmp_sockets;
static gboolean update_iceauthority (gboolean adding);
static gboolean accept_ice_connection (GIOChannel *source,
GIOCondition condition,
gpointer data);
static Status accept_xsmp_connection (SmsConn conn,
SmPointer manager_data,
unsigned long *mask_ret,
SmsCallbacks *callbacks_ret,
char **failure_reason_ret);
static void ice_error_handler (IceConn conn,
Bool swap,
int offending_minor_opcode,
unsigned long offending_sequence_num,
int error_class,
int severity,
IcePointer values);
static void ice_io_error_handler (IceConn conn);
static void sms_error_handler (SmsConn sms_conn,
Bool swap,
int offending_minor_opcode,
unsigned long offending_sequence_num,
int error_class,
int severity,
IcePointer values);
/**
* gsm_xsmp_init:
*
* Initializes XSMP. Notably, it creates the XSMP listening socket and
* sets the SESSION_MANAGER environment variable to point to it.
**/
char *
gsm_xsmp_init (void)
{
char error[256];
mode_t saved_umask;
char *network_id_list;
int i;
/* Set up sane error handlers */
IceSetErrorHandler (ice_error_handler);
IceSetIOErrorHandler (ice_io_error_handler);
SmsSetErrorHandler (sms_error_handler);
/* Initialize libSM; we pass NULL for hostBasedAuthProc to disable
* host-based authentication.
*/
if (!SmsInitialize (PACKAGE, VERSION, accept_xsmp_connection,
NULL, NULL, sizeof (error), error))
g_error("Could not initialize libSM: %s", error);
#ifdef HAVE_X11_XTRANS_XTRANS_H
/* By default, IceListenForConnections will open one socket for each
* transport type known to X. We don't want connections from remote
* hosts, so for security reasons it would be best if ICE didn't
* even open any non-local sockets. So we use an internal ICElib
* method to disable them here. Unfortunately, there is no way to
* ask X what transport types it knows about, so we're forced to
* guess.
*/
_IceTransNoListen ("tcp");
#endif
/* Create the XSMP socket. Older versions of IceListenForConnections
* have a bug which causes the umask to be set to 0 on certain types
* of failures. Probably not an issue on any modern systems, but
* we'll play it safe.
*/
saved_umask = umask (0);
umask (saved_umask);
if (!IceListenForConnections (&num_xsmp_sockets, &xsmp_sockets,
sizeof (error), error))
g_error ("Could not create ICE listening socket: %s", error);
umask (saved_umask);
/* Find the local sockets in the returned socket list and move them
* to the start of the list.
*/
for (i = num_local_xsmp_sockets = 0; i < num_xsmp_sockets; i++)
{
char *id = IceGetListenConnectionString (xsmp_sockets[i]);
if (!strncmp (id, "local/", sizeof ("local/") - 1) ||
!strncmp (id, "unix/", sizeof ("unix/") - 1))
{
if (i > num_local_xsmp_sockets)
{
IceListenObj tmp = xsmp_sockets[i];
xsmp_sockets[i] = xsmp_sockets[num_local_xsmp_sockets];
xsmp_sockets[num_local_xsmp_sockets] = tmp;
}
num_local_xsmp_sockets++;
}
free (id);
}
if (num_local_xsmp_sockets == 0)
g_error ("IceListenForConnections did not return a local listener!");
#ifdef HAVE_X11_XTRANS_XTRANS_H
if (num_local_xsmp_sockets != num_xsmp_sockets)
{
/* Xtrans was apparently compiled with support for some
* non-local transport besides TCP (which we disabled above); we
* won't create IO watches on those extra sockets, so
* connections to them will never be noticed, but they're still
* there, which is inelegant.
*
* If the g_warning below is triggering for you and you want to
* stop it, the fix is to add additional _IceTransNoListen()
* calls above.
*/
network_id_list =
IceComposeNetworkIdList (num_xsmp_sockets - num_local_xsmp_sockets,
xsmp_sockets + num_local_xsmp_sockets);
g_warning ("IceListenForConnections returned %d non-local listeners: %s",
num_xsmp_sockets - num_local_xsmp_sockets, network_id_list);
free (network_id_list);
}
#endif
/* Update .ICEauthority with new auth entries for our socket */
if (!update_iceauthority (TRUE))
{
/* FIXME: is this really fatal? Hm... */
g_error ("Could not update ICEauthority file %s",
IceAuthFileName ());
}
network_id_list = IceComposeNetworkIdList (num_local_xsmp_sockets,
xsmp_sockets);
return network_id_list;
}
/**
* gsm_xsmp_run:
*
* Sets the XSMP server to start accepting connections.
**/
void
gsm_xsmp_run (void)
{
GIOChannel *channel;
int i;
for (i = 0; i < num_local_xsmp_sockets; i++)
{
channel = g_io_channel_unix_new (IceGetListenConnectionNumber (xsmp_sockets[i]));
g_io_add_watch (channel, G_IO_IN | G_IO_HUP | G_IO_ERR,
accept_ice_connection, xsmp_sockets[i]);
g_io_channel_unref (channel);
}
}
/**
* gsm_xsmp_shutdown:
*
* Shuts down the XSMP server and closes the ICE listening socket
**/
void
gsm_xsmp_shutdown (void)
{
update_iceauthority (FALSE);
IceFreeListenObjs (num_xsmp_sockets, xsmp_sockets);
xsmp_sockets = NULL;
}
/**
* gsm_xsmp_generate_client_id:
*
* Generates a new XSMP client ID.
*
* Return value: an XSMP client ID.
**/
char *
gsm_xsmp_generate_client_id (void)
{
static int sequence = -1;
static guint rand1 = 0, rand2 = 0;
static pid_t pid = 0;
struct timeval tv;
/* The XSMP spec defines the ID as:
*
* Version: "1"
* Address type and address:
* "1" + an IPv4 address as 8 hex digits
* "2" + a DECNET address as 12 hex digits
* "6" + an IPv6 address as 32 hex digits
* Time stamp: milliseconds since UNIX epoch as 13 decimal digits
* Process-ID type and process-ID:
* "1" + POSIX PID as 10 decimal digits
* Sequence number as 4 decimal digits
*
* XSMP client IDs are supposed to be globally unique: if
* SmsGenerateClientID() is unable to determine a network
* address for the machine, it gives up and returns %NULL.
* GNOME and KDE have traditionally used a fourth address
* format in this case:
* "0" + 16 random hex digits
*
* We don't even bother trying SmsGenerateClientID(), since the
* user's IP address is probably "192.168.1.*" anyway, so a random
* number is actually more likely to be globally unique.
*/
if (!rand1)
{
rand1 = g_random_int ();
rand2 = g_random_int ();
pid = getpid ();
}
sequence = (sequence + 1) % 10000;
gettimeofday (&tv, NULL);
return g_strdup_printf ("10%.04x%.04x%.10lu%.3u%.10lu%.4d",
rand1, rand2,
(unsigned long) tv.tv_sec,
(unsigned) tv.tv_usec,
(unsigned long) pid,
sequence);
}
/* This is called (by glib via xsmp->ice_connection_watch) when a
* connection is first received on the ICE listening socket. (We
* expect that the client will then initiate XSMP on the connection;
* if it does not, GsmClientXSMP will eventually time out and close
* the connection.)
*
* FIXME: it would probably make more sense to not create a
* GsmClientXSMP object until accept_xsmp_connection, below (and to do
* the timing-out here in xsmp.c).
*/
static gboolean
accept_ice_connection (GIOChannel *source,
GIOCondition condition,
gpointer data)
{
IceListenObj listener = data;
IceConn ice_conn;
IceAcceptStatus status;
GsmClientXSMP *client;
g_debug ("accept_ice_connection()");
ice_conn = IceAcceptConnection (listener, &status);
if (status != IceAcceptSuccess)
{
g_debug ("IceAcceptConnection returned %d", status);
return TRUE;
}
client = gsm_client_xsmp_new (ice_conn);
ice_conn->context = client;
return TRUE;
}
/* This is called (by libSM) when XSMP is initiated on an ICE
* connection that was already accepted by accept_ice_connection.
*/
static Status
accept_xsmp_connection (SmsConn sms_conn, SmPointer manager_data,
unsigned long *mask_ret, SmsCallbacks *callbacks_ret,
char **failure_reason_ret)
{
IceConn ice_conn;
GsmClientXSMP *client;
/* FIXME: what about during shutdown but before gsm_xsmp_shutdown? */
if (!xsmp_sockets)
{
g_debug ("In shutdown, rejecting new client");
*failure_reason_ret =
strdup (_("Refusing new client connection because the session is currently being shut down\n"));
return FALSE;
}
ice_conn = SmsGetIceConnection (sms_conn);
client = ice_conn->context;
g_return_val_if_fail (client != NULL, TRUE);
gsm_client_xsmp_connect (client, sms_conn, mask_ret, callbacks_ret);
return TRUE;
}
/* ICEauthority stuff */
/* Various magic numbers stolen from iceauth.c */
#define GSM_ICE_AUTH_RETRIES 10
#define GSM_ICE_AUTH_INTERVAL 2 /* 2 seconds */
#define GSM_ICE_AUTH_LOCK_TIMEOUT 600 /* 10 minutes */
#define GSM_ICE_MAGIC_COOKIE_AUTH_NAME "MIT-MAGIC-COOKIE-1"
#define GSM_ICE_MAGIC_COOKIE_LEN 16
static IceAuthFileEntry *
auth_entry_new (const char *protocol, const char *network_id)
{
IceAuthFileEntry *file_entry;
IceAuthDataEntry data_entry;
file_entry = malloc (sizeof (IceAuthFileEntry));
file_entry->protocol_name = strdup (protocol);
file_entry->protocol_data = NULL;
file_entry->protocol_data_length = 0;
file_entry->network_id = strdup (network_id);
file_entry->auth_name = strdup (GSM_ICE_MAGIC_COOKIE_AUTH_NAME);
file_entry->auth_data = IceGenerateMagicCookie (GSM_ICE_MAGIC_COOKIE_LEN);
file_entry->auth_data_length = GSM_ICE_MAGIC_COOKIE_LEN;
/* Also create an in-memory copy, which is what the server will
* actually use for checking client auth.
*/
data_entry.protocol_name = file_entry->protocol_name;
data_entry.network_id = file_entry->network_id;
data_entry.auth_name = file_entry->auth_name;
data_entry.auth_data = file_entry->auth_data;
data_entry.auth_data_length = file_entry->auth_data_length;
IceSetPaAuthData (1, &data_entry);
return file_entry;
}
static gboolean
update_iceauthority (gboolean adding)
{
char *filename = IceAuthFileName ();
char **our_network_ids;
FILE *fp;
IceAuthFileEntry *auth_entry;
GSList *entries, *e;
int i;
gboolean ok = FALSE;
if (IceLockAuthFile (filename, GSM_ICE_AUTH_RETRIES, GSM_ICE_AUTH_INTERVAL,
GSM_ICE_AUTH_LOCK_TIMEOUT) != IceAuthLockSuccess)
return FALSE;
our_network_ids = g_malloc (num_local_xsmp_sockets * sizeof (char *));
for (i = 0; i < num_local_xsmp_sockets; i++)
our_network_ids[i] = IceGetListenConnectionString (xsmp_sockets[i]);
entries = NULL;
fp = fopen (filename, "r+");
if (fp)
{
while ((auth_entry = IceReadAuthFileEntry (fp)) != NULL)
{
/* Skip/delete entries with no network ID (invalid), or with
* our network ID; if we're starting up, an entry with our
* ID must be a stale entry left behind by an old process,
* and if we're shutting down, it won't be valid in the
* future, so either way we want to remove it from the list.
*/
if (!auth_entry->network_id)
{
IceFreeAuthFileEntry (auth_entry);
continue;
}
for (i = 0; i < num_local_xsmp_sockets; i++)
{
if (!strcmp (auth_entry->network_id, our_network_ids[i]))
{
IceFreeAuthFileEntry (auth_entry);
break;
}
}
if (i != num_local_xsmp_sockets)
continue;
entries = g_slist_prepend (entries, auth_entry);
}
rewind (fp);
}
else
{
int fd;
if (g_file_test (filename, G_FILE_TEST_EXISTS))
{
g_warning ("Unable to read ICE authority file: %s", filename);
goto cleanup;
}
fd = open (filename, O_CREAT | O_WRONLY, 0600);
fp = fdopen (fd, "w");
if (!fp)
{
g_warning ("Unable to write to ICE authority file: %s", filename);
if (fd != -1)
close (fd);
goto cleanup;
}
}
if (adding)
{
for (i = 0; i < num_local_xsmp_sockets; i++)
{
entries = g_slist_append (entries,
auth_entry_new ("ICE", our_network_ids[i]));
entries = g_slist_prepend (entries,
auth_entry_new ("XSMP", our_network_ids[i]));
}
}
for (e = entries; e; e = e->next)
{
IceAuthFileEntry *auth_entry = e->data;
IceWriteAuthFileEntry (fp, auth_entry);
IceFreeAuthFileEntry (auth_entry);
}
g_slist_free (entries);
fclose (fp);
ok = TRUE;
cleanup:
IceUnlockAuthFile (filename);
for (i = 0; i < num_local_xsmp_sockets; i++)
free (our_network_ids[i]);
g_free (our_network_ids);
return ok;
}
/* Error handlers */
static void
ice_error_handler (IceConn conn, Bool swap, int offending_minor_opcode,
unsigned long offending_sequence, int error_class,
int severity, IcePointer values)
{
g_debug ("ice_error_handler (%p, %s, %d, %lx, %d, %d)",
conn, swap ? "TRUE" : "FALSE", offending_minor_opcode,
offending_sequence, error_class, severity);
if (severity == IceCanContinue)
return;
/* FIXME: the ICElib docs are completely vague about what we're
* supposed to do in this case. Need to verify that calling
* IceCloseConnection() here is guaranteed to cause neither
* free-memory-reads nor leaks.
*/
IceCloseConnection (conn);
}
static void
ice_io_error_handler (IceConn conn)
{
g_debug ("ice_io_error_handler (%p)", conn);
/* We don't need to do anything here; the next call to
* IceProcessMessages() for this connection will receive
* IceProcessMessagesIOError and we can handle the error there.
*/
}
static void
sms_error_handler (SmsConn conn, Bool swap, int offending_minor_opcode,
unsigned long offending_sequence_num, int error_class,
int severity, IcePointer values)
{
g_debug ("sms_error_handler (%p, %s, %d, %lx, %d, %d)",
conn, swap ? "TRUE" : "FALSE", offending_minor_opcode,
offending_sequence_num, error_class, severity);
/* We don't need to do anything here; if the connection needs to be
* closed, libSM will do that itself.
*/
}