libpurple/protocols/qq/recv_core.c

/**
 * @file recv_core.c
 *
 * purple
 *
 * Purple is the legal property of its developers, whose names are too numerous
 * to list here.  Please refer to the COPYRIGHT file distributed with this
 * source distribution.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
 */

#include "debug.h"
#include "internal.h"

#include "buddy_info.h"
#include "buddy_list.h"
#include "buddy_opt.h"
#include "buddy_status.h"
#include "char_conv.h"
#include "crypt.h"
#include "group_network.h"
#include "header_info.h"
#include "keep_alive.h"
#include "im.h"
#include "login_logout.h"
#include "packet_parse.h"
#include "qq_proxy.h"
#include "recv_core.h"
#include "sendqueue.h"
#include "sys_msg.h"
#include "utils.h"

typedef struct _packet_before_login packet_before_login;
typedef struct _qq_recv_msg_header qq_recv_msg_header;

struct _packet_before_login {
	guint8 *buf;
	gint len;
};

struct _qq_recv_msg_header {
	guint8 header_tag;
	guint16 source_tag;
	guint16 cmd;
	guint16 seq;		/* can be ack_seq or send_seq, depends on cmd */
};

/* check whether one sequence number is duplicated or not
 * return TRUE if it is duplicated, otherwise FALSE */
static gboolean _qq_check_packet_set_window(guint16 seq, PurpleConnection *gc)
{
	qq_data *qd;
	guint8 *byte, mask;

	qd = (qq_data *) gc->proto_data;
	byte = &(qd->window[seq / 8]);
	mask = (1 << (seq % 8));

	if ((*byte) & mask)
		return TRUE;	/* check mask */
	(*byte) |= mask;
	return FALSE;		/* set mask */
}

/* default process, decrypt and dump */
static void _qq_process_packet_default(guint8 *buf, gint buf_len, guint16 cmd, guint16 seq, PurpleConnection *gc)
{
	qq_data *qd;
	guint8 *data;
	gchar *msg_utf8;
	gint len;

	g_return_if_fail(buf != NULL && buf_len != 0);

	qd = (qq_data *) gc->proto_data;
	len = buf_len;
	data = g_newa(guint8, len);
	msg_utf8 = NULL;

	_qq_show_packet("Processing unknown packet", buf, len);
	if (qq_decrypt(buf, buf_len, qd->session_key, data, &len)) {
		gchar *hex_dump = hex_dump_to_str(data, len);
		purple_debug(PURPLE_DEBUG_WARNING, "QQ",
				">>> [%d] %s, %d bytes -> [default] decrypt and dump\n%s",
				seq, qq_get_cmd_desc(cmd), buf_len, hex_dump);
		g_free(hex_dump);
		try_dump_as_gbk(data, len);
	} else {
		purple_debug(PURPLE_DEBUG_ERROR, "QQ", "Fail decrypt packet with default process\n");
	}
}

/* process the incoming packet from qq_pending */
static void _qq_packet_process(guint8 *buf, gint buf_len, PurpleConnection *gc)
{
	qq_data *qd;
	gint bytes_notread, bytes_expected, bytes;
	guint16 buf_len_read;	/* two bytes in the begining of TCP packet */
	qq_recv_msg_header header;
	packet_before_login *b4_packet;

	g_return_if_fail(buf != NULL && buf_len > 0);

	qd = (qq_data *) gc->proto_data;
	bytes_expected = qd->use_tcp ? QQ_TCP_HEADER_LENGTH : QQ_UDP_HEADER_LENGTH;

	if (buf_len < bytes_expected) {
		gchar *hex_dump = hex_dump_to_str(buf, buf_len);
		purple_debug(PURPLE_DEBUG_ERROR,
				"QQ", "Received packet is too short, dump and drop\n%s", hex_dump);
		g_free(hex_dump);
		return;
	}

	/* initialize */
	bytes = 0;
	/* QQ TCP packet returns first 2 bytes the length of this packet */
	if (qd->use_tcp) {
		bytes += qq_get16(&buf_len_read, buf + bytes);
		if (buf_len_read != buf_len) {	/* wrong */
			purple_debug
				(PURPLE_DEBUG_ERROR,
				 "QQ",
				 "TCP read %d bytes, header says %d bytes, use header anyway\n", buf_len, buf_len_read);
			buf_len = buf_len_read;	/* we believe header is more accurate */
		}
	}

	/* now goes the normal QQ packet as UDP packet */
	bytes += qq_get8(&header.header_tag, buf + bytes);
	bytes += qq_get16(&header.source_tag, buf + bytes);
	bytes += qq_get16(&header.cmd, buf + bytes);
	bytes += qq_get16(&header.seq, buf + bytes);

	if (bytes != bytes_expected) {	/* read error */
		purple_debug(PURPLE_DEBUG_ERROR, "QQ",
				"Fail reading packet header, expect %d bytes, read %d bytes\n", 
				bytes_expected, bytes);
		return;
	}

	if ((buf[buf_len - 1] != QQ_PACKET_TAIL) || (header.header_tag != QQ_PACKET_TAG)) {
		gchar *hex_dump = hex_dump_to_str(buf, buf_len);
		purple_debug(PURPLE_DEBUG_ERROR,
				"QQ", "Unknown QQ proctocol, dump and drop\n%s", hex_dump);
		g_free(hex_dump);
		return;
	}

	if (QQ_DEBUG)
		purple_debug(PURPLE_DEBUG_INFO, "QQ",
				"==> [%05d] %s, from (%s)\n",
				header.seq, qq_get_cmd_desc(header.cmd), qq_get_source_str(header.source_tag));

	if (header.cmd != QQ_CMD_LOGIN && header.cmd != QQ_CMD_REQUEST_LOGIN_TOKEN) {
		if (!qd->logged_in) {	/* packets before login */
			b4_packet = g_new0(packet_before_login, 1);
			/* must duplicate, buffer will be freed after exiting this function */
			b4_packet->buf = g_memdup(buf, buf_len);
			b4_packet->len = buf_len;
			if (qd->before_login_packets == NULL)
				qd->before_login_packets = g_queue_new();
			g_queue_push_head(qd->before_login_packets, b4_packet);
			return;	/* do not process it now */
		} else if (!g_queue_is_empty(qd->before_login_packets)) {
			/* logged_in, but we have packets before login */
			b4_packet = (packet_before_login *)
				g_queue_pop_head(qd->before_login_packets);
			_qq_packet_process(b4_packet->buf, b4_packet->len, gc);
			/* in fact this is a recursive call,  
			 * all packets before login will be processed before goes on */
			g_free(b4_packet->buf);	/* the buf is duplicated, need to be freed */
			g_free(b4_packet);
		}
	}

	/* this is the length of all the encrypted data (also remove tail tag */
	bytes_notread = buf_len - bytes - 1;

	/* whether it is an ack */
	switch (header.cmd) {
		case QQ_CMD_RECV_IM:
		case QQ_CMD_RECV_MSG_SYS:
		case QQ_CMD_RECV_MSG_FRIEND_CHANGE_STATUS:
			/* server intiated packet, we need to send ack and check duplicaion 
			 * this must be put after processing b4_packet
			 * as these packets will be passed in twice */
			if (_qq_check_packet_set_window(header.seq, gc)) {
				purple_debug(PURPLE_DEBUG_WARNING,
						"QQ", "dup [%05d] %s, discard...\n", header.seq, qq_get_cmd_desc(header.cmd));
				return;
			}
			break;
		default:{	/* ack packet, we need to update sendqueue */
				/* we do not check duplication for server ack */
				qq_sendqueue_remove(qd, header.seq);
				if (QQ_DEBUG)
					purple_debug(PURPLE_DEBUG_INFO, "QQ",
							"ack [%05d] %s, remove from sendqueue\n",
							header.seq, qq_get_cmd_desc(header.cmd));
			}
	}

	/* now process the packet */
	switch (header.cmd) {
		case QQ_CMD_KEEP_ALIVE:
			qq_process_keep_alive_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_UPDATE_INFO:
			qq_process_modify_info_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_ADD_FRIEND_WO_AUTH:
			qq_process_add_buddy_reply(buf + bytes, bytes_notread, header.seq, gc);
			break;
		case QQ_CMD_DEL_FRIEND:
			qq_process_remove_buddy_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_REMOVE_SELF:
			qq_process_remove_self_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_BUDDY_AUTH:
			qq_process_add_buddy_auth_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_GET_USER_INFO:
			qq_process_get_info_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_CHANGE_ONLINE_STATUS:
			qq_process_change_status_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_SEND_IM:
			qq_process_send_im_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_RECV_IM:
			qq_process_recv_im(buf + bytes, bytes_notread, header.seq, gc);
			break;
		case QQ_CMD_LOGIN:
			qq_process_login_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_GET_FRIENDS_LIST:
			qq_process_get_buddies_list_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_GET_FRIENDS_ONLINE:
			qq_process_get_buddies_online_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_GROUP_CMD:
			qq_process_group_cmd_reply(buf + bytes, bytes_notread, header.seq, gc);
			break;
		case QQ_CMD_GET_ALL_LIST_WITH_GROUP:
			qq_process_get_all_list_with_group_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_GET_LEVEL:
			qq_process_get_level_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_REQUEST_LOGIN_TOKEN:
			qq_process_request_login_token_reply(buf + bytes, bytes_notread, gc);
			break;
		case QQ_CMD_RECV_MSG_SYS:
			qq_process_msg_sys(buf + bytes, bytes_notread, header.seq, gc);
			break;
		case QQ_CMD_RECV_MSG_FRIEND_CHANGE_STATUS:
			qq_process_friend_change_status(buf + bytes, bytes_notread, gc);
			break;
		default:
			_qq_process_packet_default(buf + bytes, bytes_notread, header.cmd, header.seq, gc);
			break;
	}
}

/* clean up the packets before login */
void qq_b4_packets_free(qq_data *qd)
{
	packet_before_login *b4_packet;
	g_return_if_fail(qd != NULL);
	/* now clean up my own data structures */
	if (qd->before_login_packets != NULL) {
		while (NULL != (b4_packet = g_queue_pop_tail(qd->before_login_packets))) {
			g_free(b4_packet->buf);
			g_free(b4_packet);
		}
		g_queue_free(qd->before_login_packets);
	}
}

void qq_input_pending(gpointer data, gint source, PurpleInputCondition cond)
{
	PurpleConnection *gc;
	qq_data *qd;
	guint8 *buf;
	gint len;

	gc = (PurpleConnection *) data;

	if(cond != PURPLE_INPUT_READ) {
		purple_connection_error_reason(gc, PURPLE_CONNECTION_ERROR_NETWORK_ERROR,
				_("Socket error"));
		return;
	}

	qd = (qq_data *) gc->proto_data;
	buf = g_newa(guint8, MAX_PACKET_SIZE);

	/* here we have UDP proxy suppport */
	len = qq_proxy_read(qd, buf, MAX_PACKET_SIZE);
	if (len <= 0) {
		purple_connection_error_reason(gc, PURPLE_CONNECTION_ERROR_NETWORK_ERROR,
				_("Unable to read from socket"));
		return;
	} else {
		_qq_packet_process(buf, len, gc);
	}
}