/* -*- mode: C; c-file-style: "gnu" -*- */
/* dbus-transport-socket.c Socket subclasses of DBusTransport
*
* Copyright (C) 2002, 2003, 2004, 2006 Red Hat Inc.
*
* Licensed under the Academic Free License version 2.1
*
* 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 "dbus-internals.h"
#include "dbus-connection-internal.h"
#include "dbus-transport-socket.h"
#include "dbus-transport-protected.h"
#include "dbus-watch.h"
/**
* @defgroup DBusTransportSocket DBusTransport implementations for sockets
* @ingroup DBusInternals
* @brief Implementation details of DBusTransport on sockets
*
* @{
*/
/**
* Opaque object representing a socket file descriptor transport.
*/
typedef struct DBusTransportSocket DBusTransportSocket;
/**
* Implementation details of DBusTransportSocket. All members are private.
*/
struct DBusTransportSocket
{
DBusTransport base; /**< Parent instance */
int fd; /**< File descriptor. */
DBusWatch *read_watch; /**< Watch for readability. */
DBusWatch *write_watch; /**< Watch for writability. */
int max_bytes_read_per_iteration; /**< To avoid blocking too long. */
int max_bytes_written_per_iteration; /**< To avoid blocking too long. */
int message_bytes_written; /**< Number of bytes of current
* outgoing message that have
* been written.
*/
DBusString encoded_outgoing; /**< Encoded version of current
* outgoing message.
*/
DBusString encoded_incoming; /**< Encoded version of current
* incoming data.
*/
};
static void
free_watches (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
_dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
if (socket_transport->read_watch)
{
if (transport->connection)
_dbus_connection_remove_watch_unlocked (transport->connection,
socket_transport->read_watch);
_dbus_watch_invalidate (socket_transport->read_watch);
_dbus_watch_unref (socket_transport->read_watch);
socket_transport->read_watch = NULL;
}
if (socket_transport->write_watch)
{
if (transport->connection)
_dbus_connection_remove_watch_unlocked (transport->connection,
socket_transport->write_watch);
_dbus_watch_invalidate (socket_transport->write_watch);
_dbus_watch_unref (socket_transport->write_watch);
socket_transport->write_watch = NULL;
}
_dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME);
}
static void
socket_finalize (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
_dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME);
free_watches (transport);
_dbus_string_free (&socket_transport->encoded_outgoing);
_dbus_string_free (&socket_transport->encoded_incoming);
_dbus_transport_finalize_base (transport);
_dbus_assert (socket_transport->read_watch == NULL);
_dbus_assert (socket_transport->write_watch == NULL);
dbus_free (transport);
}
static void
check_write_watch (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
dbus_bool_t needed;
if (transport->connection == NULL)
return;
if (transport->disconnected)
{
_dbus_assert (socket_transport->write_watch == NULL);
return;
}
_dbus_transport_ref (transport);
if (_dbus_transport_get_is_authenticated (transport))
needed = _dbus_connection_has_messages_to_send_unlocked (transport->connection);
else
{
if (transport->send_credentials_pending)
needed = TRUE;
else
{
DBusAuthState auth_state;
auth_state = _dbus_auth_do_work (transport->auth);
/* If we need memory we install the write watch just in case,
* if there's no need for it, it will get de-installed
* next time we try reading.
*/
if (auth_state == DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND ||
auth_state == DBUS_AUTH_STATE_WAITING_FOR_MEMORY)
needed = TRUE;
else
needed = FALSE;
}
}
_dbus_verbose ("check_write_watch(): needed = %d on connection %p watch %p fd = %d outgoing messages exist %d\n",
needed, transport->connection, socket_transport->write_watch,
socket_transport->fd,
_dbus_connection_has_messages_to_send_unlocked (transport->connection));
_dbus_connection_toggle_watch_unlocked (transport->connection,
socket_transport->write_watch,
needed);
_dbus_transport_unref (transport);
}
static void
check_read_watch (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
dbus_bool_t need_read_watch;
_dbus_verbose ("%s: fd = %d\n",
_DBUS_FUNCTION_NAME, socket_transport->fd);
if (transport->connection == NULL)
return;
if (transport->disconnected)
{
_dbus_assert (socket_transport->read_watch == NULL);
return;
}
_dbus_transport_ref (transport);
if (_dbus_transport_get_is_authenticated (transport))
need_read_watch =
_dbus_counter_get_value (transport->live_messages_size) < transport->max_live_messages_size;
else
{
if (transport->receive_credentials_pending)
need_read_watch = TRUE;
else
{
/* The reason to disable need_read_watch when not WAITING_FOR_INPUT
* is to avoid spinning on the file descriptor when we're waiting
* to write or for some other part of the auth process
*/
DBusAuthState auth_state;
auth_state = _dbus_auth_do_work (transport->auth);
/* If we need memory we install the read watch just in case,
* if there's no need for it, it will get de-installed
* next time we try reading. If we're authenticated we
* install it since we normally have it installed while
* authenticated.
*/
if (auth_state == DBUS_AUTH_STATE_WAITING_FOR_INPUT ||
auth_state == DBUS_AUTH_STATE_WAITING_FOR_MEMORY ||
auth_state == DBUS_AUTH_STATE_AUTHENTICATED)
need_read_watch = TRUE;
else
need_read_watch = FALSE;
}
}
_dbus_verbose (" setting read watch enabled = %d\n", need_read_watch);
_dbus_connection_toggle_watch_unlocked (transport->connection,
socket_transport->read_watch,
need_read_watch);
_dbus_transport_unref (transport);
}
static void
do_io_error (DBusTransport *transport)
{
_dbus_transport_ref (transport);
_dbus_transport_disconnect (transport);
_dbus_transport_unref (transport);
}
/* return value is whether we successfully read any new data. */
static dbus_bool_t
read_data_into_auth (DBusTransport *transport,
dbus_bool_t *oom)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
DBusString *buffer;
int bytes_read;
*oom = FALSE;
_dbus_auth_get_buffer (transport->auth, &buffer);
bytes_read = _dbus_read_socket (socket_transport->fd,
buffer, socket_transport->max_bytes_read_per_iteration);
_dbus_auth_return_buffer (transport->auth, buffer,
bytes_read > 0 ? bytes_read : 0);
if (bytes_read > 0)
{
_dbus_verbose (" read %d bytes in auth phase\n", bytes_read);
return TRUE;
}
else if (bytes_read < 0)
{
/* EINTR already handled for us */
if (errno == ENOMEM)
{
*oom = TRUE;
}
else if (errno == EAGAIN ||
errno == EWOULDBLOCK)
; /* do nothing, just return FALSE below */
else
{
_dbus_verbose ("Error reading from remote app: %s\n",
_dbus_strerror (errno));
do_io_error (transport);
}
return FALSE;
}
else
{
_dbus_assert (bytes_read == 0);
_dbus_verbose ("Disconnected from remote app\n");
do_io_error (transport);
return FALSE;
}
}
/* Return value is whether we successfully wrote any bytes */
static dbus_bool_t
write_data_from_auth (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
int bytes_written;
const DBusString *buffer;
if (!_dbus_auth_get_bytes_to_send (transport->auth,
&buffer))
return FALSE;
bytes_written = _dbus_write_socket (socket_transport->fd,
buffer,
0, _dbus_string_get_length (buffer));
if (bytes_written > 0)
{
_dbus_auth_bytes_sent (transport->auth, bytes_written);
return TRUE;
}
else if (bytes_written < 0)
{
/* EINTR already handled for us */
if (errno == EAGAIN ||
errno == EWOULDBLOCK)
;
else
{
_dbus_verbose ("Error writing to remote app: %s\n",
_dbus_strerror (errno));
do_io_error (transport);
}
}
return FALSE;
}
static void
exchange_credentials (DBusTransport *transport,
dbus_bool_t do_reading,
dbus_bool_t do_writing)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
DBusError error;
_dbus_verbose ("exchange_credentials: do_reading = %d, do_writing = %d\n",
do_reading, do_writing);
dbus_error_init (&error);
if (do_writing && transport->send_credentials_pending)
{
if (_dbus_send_credentials_unix_socket (socket_transport->fd,
&error))
{
transport->send_credentials_pending = FALSE;
}
else
{
_dbus_verbose ("Failed to write credentials: %s\n", error.message);
dbus_error_free (&error);
do_io_error (transport);
}
}
if (do_reading && transport->receive_credentials_pending)
{
if (_dbus_read_credentials_unix_socket (socket_transport->fd,
&transport->credentials,
&error))
{
transport->receive_credentials_pending = FALSE;
}
else
{
_dbus_verbose ("Failed to read credentials %s\n", error.message);
dbus_error_free (&error);
do_io_error (transport);
}
}
if (!(transport->send_credentials_pending ||
transport->receive_credentials_pending))
{
_dbus_auth_set_credentials (transport->auth,
&transport->credentials);
}
}
static dbus_bool_t
do_authentication (DBusTransport *transport,
dbus_bool_t do_reading,
dbus_bool_t do_writing,
dbus_bool_t *auth_completed)
{
dbus_bool_t oom;
dbus_bool_t orig_auth_state;
oom = FALSE;
orig_auth_state = _dbus_transport_get_is_authenticated (transport);
/* This is essential to avoid the check_write_watch() at the end,
* we don't want to add a write watch in do_iteration before
* we try writing and get EAGAIN
*/
if (orig_auth_state)
{
if (auth_completed)
*auth_completed = FALSE;
return TRUE;
}
_dbus_transport_ref (transport);
while (!_dbus_transport_get_is_authenticated (transport) &&
_dbus_transport_get_is_connected (transport))
{
exchange_credentials (transport, do_reading, do_writing);
if (transport->send_credentials_pending ||
transport->receive_credentials_pending)
{
_dbus_verbose ("send_credentials_pending = %d receive_credentials_pending = %d\n",
transport->send_credentials_pending,
transport->receive_credentials_pending);
goto out;
}
#define TRANSPORT_SIDE(t) ((t)->is_server ? "server" : "client")
switch (_dbus_auth_do_work (transport->auth))
{
case DBUS_AUTH_STATE_WAITING_FOR_INPUT:
_dbus_verbose (" %s auth state: waiting for input\n",
TRANSPORT_SIDE (transport));
if (!do_reading || !read_data_into_auth (transport, &oom))
goto out;
break;
case DBUS_AUTH_STATE_WAITING_FOR_MEMORY:
_dbus_verbose (" %s auth state: waiting for memory\n",
TRANSPORT_SIDE (transport));
oom = TRUE;
goto out;
break;
case DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND:
_dbus_verbose (" %s auth state: bytes to send\n",
TRANSPORT_SIDE (transport));
if (!do_writing || !write_data_from_auth (transport))
goto out;
break;
case DBUS_AUTH_STATE_NEED_DISCONNECT:
_dbus_verbose (" %s auth state: need to disconnect\n",
TRANSPORT_SIDE (transport));
do_io_error (transport);
break;
case DBUS_AUTH_STATE_AUTHENTICATED:
_dbus_verbose (" %s auth state: authenticated\n",
TRANSPORT_SIDE (transport));
break;
}
}
out:
if (auth_completed)
*auth_completed = (orig_auth_state != _dbus_transport_get_is_authenticated (transport));
check_read_watch (transport);
check_write_watch (transport);
_dbus_transport_unref (transport);
if (oom)
return FALSE;
else
return TRUE;
}
/* returns false on oom */
static dbus_bool_t
do_writing (DBusTransport *transport)
{
int total;
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
dbus_bool_t oom;
/* No messages without authentication! */
if (!_dbus_transport_get_is_authenticated (transport))
{
_dbus_verbose ("Not authenticated, not writing anything\n");
return TRUE;
}
if (transport->disconnected)
{
_dbus_verbose ("Not connected, not writing anything\n");
return TRUE;
}
#if 1
_dbus_verbose ("do_writing(), have_messages = %d, fd = %d\n",
_dbus_connection_has_messages_to_send_unlocked (transport->connection),
socket_transport->fd);
#endif
oom = FALSE;
total = 0;
while (!transport->disconnected &&
_dbus_connection_has_messages_to_send_unlocked (transport->connection))
{
int bytes_written;
DBusMessage *message;
const DBusString *header;
const DBusString *body;
int header_len, body_len;
int total_bytes_to_write;
if (total > socket_transport->max_bytes_written_per_iteration)
{
_dbus_verbose ("%d bytes exceeds %d bytes written per iteration, returning\n",
total, socket_transport->max_bytes_written_per_iteration);
goto out;
}
message = _dbus_connection_get_message_to_send (transport->connection);
_dbus_assert (message != NULL);
_dbus_message_lock (message);
#if 0
_dbus_verbose ("writing message %p\n", message);
#endif
_dbus_message_get_network_data (message,
&header, &body);
header_len = _dbus_string_get_length (header);
body_len = _dbus_string_get_length (body);
if (_dbus_auth_needs_encoding (transport->auth))
{
if (_dbus_string_get_length (&socket_transport->encoded_outgoing) == 0)
{
if (!_dbus_auth_encode_data (transport->auth,
header, &socket_transport->encoded_outgoing))
{
oom = TRUE;
goto out;
}
if (!_dbus_auth_encode_data (transport->auth,
body, &socket_transport->encoded_outgoing))
{
_dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
oom = TRUE;
goto out;
}
}
total_bytes_to_write = _dbus_string_get_length (&socket_transport->encoded_outgoing);
#if 0
_dbus_verbose ("encoded message is %d bytes\n",
total_bytes_to_write);
#endif
bytes_written =
_dbus_write_socket (socket_transport->fd,
&socket_transport->encoded_outgoing,
socket_transport->message_bytes_written,
total_bytes_to_write - socket_transport->message_bytes_written);
}
else
{
total_bytes_to_write = header_len + body_len;
#if 0
_dbus_verbose ("message is %d bytes\n",
total_bytes_to_write);
#endif
if (socket_transport->message_bytes_written < header_len)
{
bytes_written =
_dbus_write_socket_two (socket_transport->fd,
header,
socket_transport->message_bytes_written,
header_len - socket_transport->message_bytes_written,
body,
0, body_len);
}
else
{
bytes_written =
_dbus_write_socket (socket_transport->fd,
body,
(socket_transport->message_bytes_written - header_len),
body_len -
(socket_transport->message_bytes_written - header_len));
}
}
if (bytes_written < 0)
{
/* EINTR already handled for us */
if (errno == EAGAIN ||
errno == EWOULDBLOCK)
goto out;
else
{
_dbus_verbose ("Error writing to remote app: %s\n",
_dbus_strerror (errno));
do_io_error (transport);
goto out;
}
}
else
{
_dbus_verbose (" wrote %d bytes of %d\n", bytes_written,
total_bytes_to_write);
total += bytes_written;
socket_transport->message_bytes_written += bytes_written;
_dbus_assert (socket_transport->message_bytes_written <=
total_bytes_to_write);
if (socket_transport->message_bytes_written == total_bytes_to_write)
{
socket_transport->message_bytes_written = 0;
_dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
_dbus_connection_message_sent (transport->connection,
message);
}
}
}
out:
if (oom)
return FALSE;
else
return TRUE;
}
/* returns false on out-of-memory */
static dbus_bool_t
do_reading (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
DBusString *buffer;
int bytes_read;
int total;
dbus_bool_t oom;
_dbus_verbose ("%s: fd = %d\n", _DBUS_FUNCTION_NAME,
socket_transport->fd);
/* No messages without authentication! */
if (!_dbus_transport_get_is_authenticated (transport))
return TRUE;
oom = FALSE;
total = 0;
again:
/* See if we've exceeded max messages and need to disable reading */
check_read_watch (transport);
if (total > socket_transport->max_bytes_read_per_iteration)
{
_dbus_verbose ("%d bytes exceeds %d bytes read per iteration, returning\n",
total, socket_transport->max_bytes_read_per_iteration);
goto out;
}
_dbus_assert (socket_transport->read_watch != NULL ||
transport->disconnected);
if (transport->disconnected)
goto out;
if (!dbus_watch_get_enabled (socket_transport->read_watch))
return TRUE;
if (_dbus_auth_needs_decoding (transport->auth))
{
if (_dbus_string_get_length (&socket_transport->encoded_incoming) > 0)
bytes_read = _dbus_string_get_length (&socket_transport->encoded_incoming);
else
bytes_read = _dbus_read_socket (socket_transport->fd,
&socket_transport->encoded_incoming,
socket_transport->max_bytes_read_per_iteration);
_dbus_assert (_dbus_string_get_length (&socket_transport->encoded_incoming) ==
bytes_read);
if (bytes_read > 0)
{
int orig_len;
_dbus_message_loader_get_buffer (transport->loader,
&buffer);
orig_len = _dbus_string_get_length (buffer);
if (!_dbus_auth_decode_data (transport->auth,
&socket_transport->encoded_incoming,
buffer))
{
_dbus_verbose ("Out of memory decoding incoming data\n");
oom = TRUE;
goto out;
}
_dbus_message_loader_return_buffer (transport->loader,
buffer,
_dbus_string_get_length (buffer) - orig_len);
_dbus_string_set_length (&socket_transport->encoded_incoming, 0);
}
}
else
{
_dbus_message_loader_get_buffer (transport->loader,
&buffer);
bytes_read = _dbus_read_socket (socket_transport->fd,
buffer, socket_transport->max_bytes_read_per_iteration);
_dbus_message_loader_return_buffer (transport->loader,
buffer,
bytes_read < 0 ? 0 : bytes_read);
}
if (bytes_read < 0)
{
/* EINTR already handled for us */
if (errno == ENOMEM)
{
_dbus_verbose ("Out of memory in read()/do_reading()\n");
oom = TRUE;
goto out;
}
else if (errno == EAGAIN ||
errno == EWOULDBLOCK)
goto out;
else
{
_dbus_verbose ("Error reading from remote app: %s\n",
_dbus_strerror (errno));
do_io_error (transport);
goto out;
}
}
else if (bytes_read == 0)
{
_dbus_verbose ("Disconnected from remote app\n");
do_io_error (transport);
goto out;
}
else
{
_dbus_verbose (" read %d bytes\n", bytes_read);
total += bytes_read;
if (!_dbus_transport_queue_messages (transport))
{
oom = TRUE;
_dbus_verbose (" out of memory when queueing messages we just read in the transport\n");
goto out;
}
/* Try reading more data until we get EAGAIN and return, or
* exceed max bytes per iteration. If in blocking mode of
* course we'll block instead of returning.
*/
goto again;
}
out:
if (oom)
return FALSE;
else
return TRUE;
}
static dbus_bool_t
socket_handle_watch (DBusTransport *transport,
DBusWatch *watch,
unsigned int flags)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
_dbus_assert (watch == socket_transport->read_watch ||
watch == socket_transport->write_watch);
_dbus_assert (watch != NULL);
/* Disconnect in case of an error. In case of hangup do not
* disconnect the transport because data can still be in the buffer
* and do_reading may need several iteration to read it all (because
* of its max_bytes_read_per_iteration limit). The condition where
* flags == HANGUP (without READABLE) probably never happen in fact.
*/
if ((flags & DBUS_WATCH_ERROR) ||
((flags & DBUS_WATCH_HANGUP) && !(flags & DBUS_WATCH_READABLE)))
{
_dbus_verbose ("Hang up or error on watch\n");
_dbus_transport_disconnect (transport);
return TRUE;
}
if (watch == socket_transport->read_watch &&
(flags & DBUS_WATCH_READABLE))
{
dbus_bool_t auth_finished;
#if 1
_dbus_verbose ("handling read watch %p flags = %x\n",
watch, flags);
#endif
if (!do_authentication (transport, TRUE, FALSE, &auth_finished))
return FALSE;
/* We don't want to do a read immediately following
* a successful authentication. This is so we
* have a chance to propagate the authentication
* state further up. Specifically, we need to
* process any pending data from the auth object.
*/
if (!auth_finished)
{
if (!do_reading (transport))
{
_dbus_verbose ("no memory to read\n");
return FALSE;
}
}
else
{
_dbus_verbose ("Not reading anything since we just completed the authentication\n");
}
}
else if (watch == socket_transport->write_watch &&
(flags & DBUS_WATCH_WRITABLE))
{
#if 1
_dbus_verbose ("handling write watch, have_outgoing_messages = %d\n",
_dbus_connection_has_messages_to_send_unlocked (transport->connection));
#endif
if (!do_authentication (transport, FALSE, TRUE, NULL))
return FALSE;
if (!do_writing (transport))
{
_dbus_verbose ("no memory to write\n");
return FALSE;
}
/* See if we still need the write watch */
check_write_watch (transport);
}
#ifdef DBUS_ENABLE_VERBOSE_MODE
else
{
if (watch == socket_transport->read_watch)
_dbus_verbose ("asked to handle read watch with non-read condition 0x%x\n",
flags);
else if (watch == socket_transport->write_watch)
_dbus_verbose ("asked to handle write watch with non-write condition 0x%x\n",
flags);
else
_dbus_verbose ("asked to handle watch %p on fd %d that we don't recognize\n",
watch, dbus_watch_get_fd (watch));
}
#endif /* DBUS_ENABLE_VERBOSE_MODE */
return TRUE;
}
static void
socket_disconnect (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
_dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME);
free_watches (transport);
_dbus_close_socket (socket_transport->fd, NULL);
socket_transport->fd = -1;
}
static dbus_bool_t
socket_connection_set (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
_dbus_watch_set_handler (socket_transport->write_watch,
_dbus_connection_handle_watch,
transport->connection, NULL);
_dbus_watch_set_handler (socket_transport->read_watch,
_dbus_connection_handle_watch,
transport->connection, NULL);
if (!_dbus_connection_add_watch_unlocked (transport->connection,
socket_transport->write_watch))
return FALSE;
if (!_dbus_connection_add_watch_unlocked (transport->connection,
socket_transport->read_watch))
{
_dbus_connection_remove_watch_unlocked (transport->connection,
socket_transport->write_watch);
return FALSE;
}
check_read_watch (transport);
check_write_watch (transport);
return TRUE;
}
/**
* @todo We need to have a way to wake up the select sleep if
* a new iteration request comes in with a flag (read/write) that
* we're not currently serving. Otherwise a call that just reads
* could block a write call forever (if there are no incoming
* messages).
*/
static void
socket_do_iteration (DBusTransport *transport,
unsigned int flags,
int timeout_milliseconds)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
DBusPollFD poll_fd;
int poll_res;
int poll_timeout;
_dbus_verbose (" iteration flags = %s%s timeout = %d read_watch = %p write_watch = %p fd = %d\n",
flags & DBUS_ITERATION_DO_READING ? "read" : "",
flags & DBUS_ITERATION_DO_WRITING ? "write" : "",
timeout_milliseconds,
socket_transport->read_watch,
socket_transport->write_watch,
socket_transport->fd);
/* the passed in DO_READING/DO_WRITING flags indicate whether to
* read/write messages, but regardless of those we may need to block
* for reading/writing to do auth. But if we do reading for auth,
* we don't want to read any messages yet if not given DO_READING.
*/
poll_fd.fd = socket_transport->fd;
poll_fd.events = 0;
if (_dbus_transport_get_is_authenticated (transport))
{
/* This is kind of a hack; if we have stuff to write, then try
* to avoid the poll. This is probably about a 5% speedup on an
* echo client/server.
*
* If both reading and writing were requested, we want to avoid this
* since it could have funky effects:
* - both ends spinning waiting for the other one to read
* data so they can finish writing
* - prioritizing all writing ahead of reading
*/
if ((flags & DBUS_ITERATION_DO_WRITING) &&
!(flags & (DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK)) &&
!transport->disconnected &&
_dbus_connection_has_messages_to_send_unlocked (transport->connection))
{
do_writing (transport);
if (transport->disconnected ||
!_dbus_connection_has_messages_to_send_unlocked (transport->connection))
goto out;
}
/* If we get here, we decided to do the poll() after all */
_dbus_assert (socket_transport->read_watch);
if (flags & DBUS_ITERATION_DO_READING)
poll_fd.events |= _DBUS_POLLIN;
_dbus_assert (socket_transport->write_watch);
if (flags & DBUS_ITERATION_DO_WRITING)
poll_fd.events |= _DBUS_POLLOUT;
}
else
{
DBusAuthState auth_state;
auth_state = _dbus_auth_do_work (transport->auth);
if (transport->receive_credentials_pending ||
auth_state == DBUS_AUTH_STATE_WAITING_FOR_INPUT)
poll_fd.events |= _DBUS_POLLIN;
if (transport->send_credentials_pending ||
auth_state == DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND)
poll_fd.events |= _DBUS_POLLOUT;
}
if (poll_fd.events)
{
if (flags & DBUS_ITERATION_BLOCK)
poll_timeout = timeout_milliseconds;
else
poll_timeout = 0;
/* For blocking selects we drop the connection lock here
* to avoid blocking out connection access during a potentially
* indefinite blocking call. The io path is still protected
* by the io_path_cond condvar, so we won't reenter this.
*/
if (flags & DBUS_ITERATION_BLOCK)
{
_dbus_verbose ("unlock %s pre poll\n", _DBUS_FUNCTION_NAME);
_dbus_connection_unlock (transport->connection);
}
again:
poll_res = _dbus_poll (&poll_fd, 1, poll_timeout);
if (poll_res < 0 && errno == EINTR)
goto again;
if (flags & DBUS_ITERATION_BLOCK)
{
_dbus_verbose ("lock %s post poll\n", _DBUS_FUNCTION_NAME);
_dbus_connection_lock (transport->connection);
}
if (poll_res >= 0)
{
if (poll_res == 0)
poll_fd.revents = 0; /* some concern that posix does not guarantee this;
* valgrind flags it as an error. though it probably
* is guaranteed on linux at least.
*/
if (poll_fd.revents & _DBUS_POLLERR)
do_io_error (transport);
else
{
dbus_bool_t need_read = (poll_fd.revents & _DBUS_POLLIN) > 0;
dbus_bool_t need_write = (poll_fd.revents & _DBUS_POLLOUT) > 0;
dbus_bool_t authentication_completed;
_dbus_verbose ("in iteration, need_read=%d need_write=%d\n",
need_read, need_write);
do_authentication (transport, need_read, need_write,
&authentication_completed);
/* See comment in socket_handle_watch. */
if (authentication_completed)
goto out;
if (need_read && (flags & DBUS_ITERATION_DO_READING))
do_reading (transport);
if (need_write && (flags & DBUS_ITERATION_DO_WRITING))
do_writing (transport);
}
}
else
{
_dbus_verbose ("Error from _dbus_poll(): %s\n",
_dbus_strerror (errno));
}
}
out:
/* We need to install the write watch only if we did not
* successfully write everything. Note we need to be careful that we
* don't call check_write_watch *before* do_writing, since it's
* inefficient to add the write watch, and we can avoid it most of
* the time since we can write immediately.
*
* However, we MUST always call check_write_watch(); DBusConnection code
* relies on the fact that running an iteration will notice that
* messages are pending.
*/
check_write_watch (transport);
_dbus_verbose (" ... leaving do_iteration()\n");
}
static void
socket_live_messages_changed (DBusTransport *transport)
{
/* See if we should look for incoming messages again */
check_read_watch (transport);
}
static dbus_bool_t
socket_get_socket_fd (DBusTransport *transport,
int *fd_p)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
*fd_p = socket_transport->fd;
return TRUE;
}
static const DBusTransportVTable socket_vtable = {
socket_finalize,
socket_handle_watch,
socket_disconnect,
socket_connection_set,
socket_do_iteration,
socket_live_messages_changed,
socket_get_socket_fd
};
/**
* Creates a new transport for the given socket file descriptor. The file
* descriptor must be nonblocking (use _dbus_set_fd_nonblocking() to
* make it so). This function is shared by various transports that
* boil down to a full duplex file descriptor.
*
* @param fd the file descriptor.
* @param server_guid non-#NULL if this transport is on the server side of a connection
* @param address the transport's address
* @returns the new transport, or #NULL if no memory.
*/
DBusTransport*
_dbus_transport_new_for_socket (int fd,
const DBusString *server_guid,
const DBusString *address)
{
DBusTransportSocket *socket_transport;
socket_transport = dbus_new0 (DBusTransportSocket, 1);
if (socket_transport == NULL)
return NULL;
if (!_dbus_string_init (&socket_transport->encoded_outgoing))
goto failed_0;
if (!_dbus_string_init (&socket_transport->encoded_incoming))
goto failed_1;
socket_transport->write_watch = _dbus_watch_new (fd,
DBUS_WATCH_WRITABLE,
FALSE,
NULL, NULL, NULL);
if (socket_transport->write_watch == NULL)
goto failed_2;
socket_transport->read_watch = _dbus_watch_new (fd,
DBUS_WATCH_READABLE,
FALSE,
NULL, NULL, NULL);
if (socket_transport->read_watch == NULL)
goto failed_3;
if (!_dbus_transport_init_base (&socket_transport->base,
&socket_vtable,
server_guid, address))
goto failed_4;
socket_transport->fd = fd;
socket_transport->message_bytes_written = 0;
/* These values should probably be tunable or something. */
socket_transport->max_bytes_read_per_iteration = 2048;
socket_transport->max_bytes_written_per_iteration = 2048;
return (DBusTransport*) socket_transport;
failed_4:
_dbus_watch_unref (socket_transport->read_watch);
failed_3:
_dbus_watch_unref (socket_transport->write_watch);
failed_2:
_dbus_string_free (&socket_transport->encoded_incoming);
failed_1:
_dbus_string_free (&socket_transport->encoded_outgoing);
failed_0:
dbus_free (socket_transport);
return NULL;
}
/**
* Creates a new transport for the given hostname and port.
*
* @param host the host to connect to
* @param port the port to connect to
* @param error location to store reason for failure.
* @returns a new transport, or #NULL on failure.
*/
DBusTransport*
_dbus_transport_new_for_tcp_socket (const char *host,
dbus_int32_t port,
DBusError *error)
{
int fd;
DBusTransport *transport;
DBusString address;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
if (!_dbus_string_init (&address))
{
dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
return NULL;
}
if (!_dbus_string_append (&address, "tcp:"))
goto error;
if (host != NULL &&
(!_dbus_string_append (&address, "host=") ||
!_dbus_string_append (&address, host)))
goto error;
if (!_dbus_string_append (&address, ",port=") ||
!_dbus_string_append_int (&address, port))
goto error;
fd = _dbus_connect_tcp_socket (host, port, error);
if (fd < 0)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
_dbus_string_free (&address);
return NULL;
}
_dbus_fd_set_close_on_exec (fd);
_dbus_verbose ("Successfully connected to tcp socket %s:%d\n",
host, port);
transport = _dbus_transport_new_for_socket (fd, NULL, &address);
if (transport == NULL)
{
dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
_dbus_close_socket (fd, NULL);
_dbus_string_free (&address);
fd = -1;
}
_dbus_string_free (&address);
return transport;
error:
_dbus_string_free (&address);
dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
return NULL;
}
/**
* Opens a TCP socket transport.
*
* @param entry the address entry to try opening as a tcp transport.
* @param transport_p return location for the opened transport
* @param error error to be set
* @returns result of the attempt
*/
DBusTransportOpenResult
_dbus_transport_open_socket(DBusAddressEntry *entry,
DBusTransport **transport_p,
DBusError *error)
{
const char *method;
method = dbus_address_entry_get_method (entry);
_dbus_assert (method != NULL);
if (strcmp (method, "tcp") == 0)
{
const char *host = dbus_address_entry_get_value (entry, "host");
const char *port = dbus_address_entry_get_value (entry, "port");
DBusString str;
long lport;
dbus_bool_t sresult;
if (port == NULL)
{
_dbus_set_bad_address (error, "tcp", "port", NULL);
return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
}
_dbus_string_init_const (&str, port);
sresult = _dbus_string_parse_int (&str, 0, &lport, NULL);
_dbus_string_free (&str);
if (sresult == FALSE || lport <= 0 || lport > 65535)
{
_dbus_set_bad_address (error, NULL, NULL,
"Port is not an integer between 0 and 65535");
return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
}
*transport_p = _dbus_transport_new_for_tcp_socket (host, lport, error);
if (*transport_p == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
}
else
{
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
return DBUS_TRANSPORT_OPEN_OK;
}
}
else
{
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
return DBUS_TRANSPORT_OPEN_NOT_HANDLED;
}
}
/** @} */