file_trans.c

Linux下的多协议即时通讯程序源代码

/**
 * @file file_trans.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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifdef _WIN32
#define random rand
#endif

#include "debug.h"
#include "ft.h"
#include "cipher.h"

#include "crypt.h"
#include "file_trans.h"
#include "header_info.h"
#include "im.h"
#include "packet_parse.h"
#include "proxy.h"
#include "send_core.h"
#include "send_file.h"
#include "utils.h"

struct _qq_file_header {
	guint8 tag;
	guint16 client_ver;
	guint8 file_key;
	guint32 sender_uid;
	guint32 receiver_uid;
};

typedef struct _qq_file_header qq_file_header;

static guint32 _get_file_key(guint8 seed)
{
	guint32 key;
	key = seed | (seed << 8) | (seed << 16) | (seed << 24);
	return key;
}
		
static guint32 _gen_file_key()
{
	guint8 seed;
	
	seed = random();
	return _get_file_key(seed);
}

static guint32 _decrypt_qq_uid(guint32 uid, guint32 key)
{
	return ~(uid ^ key);
}

static guint32 _encrypt_qq_uid(guint32 uid, guint32 key)
{
	return (~uid) ^ key;
}

static void _fill_filename_md5(const gchar *filename, guint8 *md5)
{
	PurpleCipher *cipher;
	PurpleCipherContext *context;

	g_return_if_fail(filename != NULL && md5 != NULL);

	cipher = purple_ciphers_find_cipher("md5");
	context = purple_cipher_context_new(cipher, NULL);
	purple_cipher_context_append(context, (guint8 *) filename, strlen(filename));
	purple_cipher_context_digest(context, 16, md5, NULL);
	purple_cipher_context_destroy(context);
}

static void _fill_file_md5(const gchar *filename, gint filelen, guint8 *md5)
{
	FILE *fp;
	guint8 *buffer;
	PurpleCipher *cipher;
	PurpleCipherContext *context;

	const gint QQ_MAX_FILE_MD5_LENGTH = 10002432;

	g_return_if_fail(filename != NULL && md5 != NULL);
	if (filelen > QQ_MAX_FILE_MD5_LENGTH) 
		filelen = QQ_MAX_FILE_MD5_LENGTH;

	fp = fopen(filename, "rb");
	g_return_if_fail(fp != NULL);

	buffer = g_newa(guint8, filelen);
	g_return_if_fail(buffer != NULL);
	fread(buffer, filelen, 1, fp);

	cipher = purple_ciphers_find_cipher("md5");
	context = purple_cipher_context_new(cipher, NULL);
	purple_cipher_context_append(context, buffer, filelen);
	purple_cipher_context_digest(context, 16, md5, NULL);
	purple_cipher_context_destroy(context);

	fclose(fp);
}

static void _qq_get_file_header(guint8 *buf, guint8 **cursor, gint buflen, qq_file_header *fh)
{
	read_packet_b(buf, cursor, buflen, &(fh->tag));
	read_packet_w(buf, cursor, buflen, &(fh->client_ver));
	read_packet_b(buf, cursor, buflen, &fh->file_key);
	read_packet_dw(buf, cursor, buflen, &(fh->sender_uid));
	read_packet_dw(buf, cursor, buflen, &(fh->receiver_uid));

	fh->sender_uid = _decrypt_qq_uid(fh->sender_uid, _get_file_key(fh->file_key));
	fh->receiver_uid = _decrypt_qq_uid(fh->receiver_uid, _get_file_key(fh->file_key));
}

static const gchar *qq_get_file_cmd_desc(gint type)
{
	switch (type) {
		case QQ_FILE_CMD_SENDER_SAY_HELLO:
			return "QQ_FILE_CMD_SENDER_SAY_HELLO";
		case QQ_FILE_CMD_SENDER_SAY_HELLO_ACK:
			return "QQ_FILE_CMD_SENDER_SAY_HELLO_ACK";
		case QQ_FILE_CMD_RECEIVER_SAY_HELLO:
			return "QQ_FILE_CMD_RECEIVER_SAY_HELLO";
		case QQ_FILE_CMD_RECEIVER_SAY_HELLO_ACK:
			return "QQ_FILE_CMD_RECEIVER_SAY_HELLO_ACK";
		case QQ_FILE_CMD_NOTIFY_IP_ACK:
			return "QQ_FILE_CMD_NOTIFY_IP_ACK";
		case QQ_FILE_CMD_PING:
			return "QQ_FILE_CMD_PING";
		case QQ_FILE_CMD_PONG:
			return "QQ_FILE_CMD_PONG";
		case QQ_FILE_CMD_INITATIVE_CONNECT:
			return "QQ_FILE_CMD_INITATIVE_CONNECT";
		case QQ_FILE_CMD_FILE_OP:
			return "QQ_FILE_CMD_FILE_OP";
		case QQ_FILE_CMD_FILE_OP_ACK:
			return "QQ_FILE_CMD_FILE_OP_ACK";
		case QQ_FILE_BASIC_INFO:
			return "QQ_FILE_BASIC_INFO";
		case QQ_FILE_DATA_INFO:
			return "QQ_FILE_DATA_INFO";
		case QQ_FILE_EOF:
			return "QQ_FILE_EOF";
		default:
			return "UNKNOWN_TYPE";
	}
}

/* The memmap version has better performance for big files transfering
 * but it will spend plenty of memory, so do not use it in a low-memory host */
#ifdef USE_MMAP
#include <sys/mman.h>

static int _qq_xfer_open_file(const gchar *filename, const gchar *method, PurpleXfer *xfer)
{
	ft_info *info = xfer->data;
	int fd;
	if (method[0] == 'r') {
		fd = open(purple_xfer_get_local_filename(xfer), O_RDONLY);
		info->buffer = mmap(0, purple_xfer_get_size(xfer), PROT_READ, MAP_PRIVATE, fd, 0);
	}
	else 
	{
		fd = open(purple_xfer_get_local_filename(xfer), O_RDWR|O_CREAT, 0644);
		info->buffer = mmap(0, purple_xfer_get_size(xfer), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FILE, fd, 0);
	}
		
	if (info->buffer == NULL) {
		return - 1;
	}
	return 0;
}

static gint _qq_xfer_read_file(guint8 *buffer, guint index, guint len, PurpleXfer *xfer)
{
	ft_info *info = xfer->data;
	gint readbytes;

	buffer = info->buffer + len * index;
	readbytes = purple_xfer_get_size(xfer) - (buffer - info->buffer);
	if (readbytes > info->fragment_len) readbytes = info->fragment_len;
	return readbytes;
}

static gint _qq_xfer_write_file(guint8 *buffer, guint index, guint len, PurpleXfer *xfer)
{
	ft_info *info = xfer->data;

	memcpy(info->buffer + index * len, buffer, len);
	return 0;
}

void qq_xfer_close_file(PurpleXfer *xfer)
{
	ft_info *info = xfer->data;

	if (info->buffer) munmap(info->buffer, purple_xfer_get_size(xfer));
}
#else
static int _qq_xfer_open_file(const gchar *filename, const gchar *method, PurpleXfer *xfer)
{
	ft_info *info = xfer->data;
	info->dest_fp = fopen(purple_xfer_get_local_filename(xfer), method);
	if (info->dest_fp == NULL) {
		return -1;
	}
	return 0;
}

static gint _qq_xfer_read_file(guint8 *buffer, guint index, guint len, PurpleXfer *xfer)
{
	ft_info *info = xfer->data;

	fseek(info->dest_fp, index * len, SEEK_SET);
	return fread(buffer, 1, len, info->dest_fp);
}

static gint _qq_xfer_write_file(guint8 *buffer, guint index, guint len, PurpleXfer *xfer)
{
	ft_info *info = xfer->data;
	fseek(info->dest_fp, index * len, SEEK_SET);
	return fwrite(buffer, 1, len, info->dest_fp);
}

void qq_xfer_close_file(PurpleXfer *xfer)
{
	ft_info *info = xfer->data;

	if (info->dest_fp) fclose(info->dest_fp);
}
#endif

static gint _qq_send_file(PurpleConnection *gc, guint8 *data, gint len, guint16 packet_type, guint32 to_uid)
{
	gint bytes;
	guint8 *cursor, *buf;
	guint32 file_key;
	qq_data *qd;
	ft_info *info;

	qd = (qq_data *) gc->proto_data;
	g_return_val_if_fail(qd->session_key != NULL, -1);
	info = (ft_info *) qd->xfer->data;
	bytes = 0;

	buf = g_newa(guint8, MAX_PACKET_SIZE);
	cursor = buf;
	file_key = _gen_file_key();

	bytes += create_packet_b(buf, &cursor, packet_type);
	bytes += create_packet_w(buf, &cursor, QQ_CLIENT);
	bytes += create_packet_b(buf, &cursor, file_key & 0xff);
	bytes += create_packet_dw(buf, &cursor, _encrypt_qq_uid(qd->uid, file_key));
	bytes += create_packet_dw(buf, &cursor, _encrypt_qq_uid(to_uid, file_key));
	bytes += create_packet_data(buf, &cursor, data, len);

	if (bytes == len + 12) {
		_qq_xfer_write(buf, bytes, qd->xfer);
	} else
		purple_debug(PURPLE_DEBUG_INFO, "QQ", "send_file: want %d but got %d\n", len + 12, bytes);
	return bytes;
}

/* send a file to udp channel with QQ_FILE_CONTROL_PACKET_TAG */
void qq_send_file_ctl_packet(PurpleConnection *gc, guint16 packet_type, guint32 to_uid, guint8 hellobyte)
{
	qq_data *qd;
	gint bytes, bytes_expected, encrypted_len;
	guint8 *raw_data, *cursor, *encrypted_data;
	time_t now;
	ft_info *info;
	
	qd = (qq_data *) gc->proto_data;
	info = (ft_info *) qd->xfer->data;

	raw_data = g_new0 (guint8, 61);
	cursor = raw_data;
	
	bytes = 0;
	now = time(NULL);

	bytes += create_packet_data(raw_data, &cursor, qd->session_md5, 16);
	bytes += create_packet_w(raw_data, &cursor, packet_type);
	switch (packet_type) {
		case QQ_FILE_CMD_SENDER_SAY_HELLO:
		case QQ_FILE_CMD_SENDER_SAY_HELLO_ACK:
		case QQ_FILE_CMD_RECEIVER_SAY_HELLO_ACK:
		case QQ_FILE_CMD_NOTIFY_IP_ACK:
		case QQ_FILE_CMD_RECEIVER_SAY_HELLO:
			bytes += create_packet_w(raw_data, &cursor, info->send_seq);
			break;
		default:
			bytes += create_packet_w(raw_data, &cursor, ++qd->send_seq);
	}
	bytes += create_packet_dw(raw_data, &cursor, (guint32) now);
	bytes += create_packet_b(raw_data, &cursor, 0x00);
	bytes += create_packet_b(raw_data, &cursor, qd->my_icon);
	bytes += create_packet_dw(raw_data, &cursor, 0x00000000);
	bytes += create_packet_dw(raw_data, &cursor, 0x00000000);
	bytes += create_packet_dw(raw_data, &cursor, 0x00000000);
	bytes += create_packet_dw(raw_data, &cursor, 0x00000000);
	bytes += create_packet_w(raw_data, &cursor, 0x0000);
	bytes += create_packet_b(raw_data, &cursor, 0x00);
	/* 0x65: send a file, 0x6b: send a custom face */
	bytes += create_packet_b(raw_data, &cursor, QQ_FILE_TRANSFER_FILE); /* FIXME temp by gfhuang */
	switch (packet_type)
	{
		case QQ_FILE_CMD_SENDER_SAY_HELLO:
		case QQ_FILE_CMD_RECEIVER_SAY_HELLO:
		case QQ_FILE_CMD_SENDER_SAY_HELLO_ACK:
		case QQ_FILE_CMD_RECEIVER_SAY_HELLO_ACK:
			bytes += create_packet_b(raw_data, &cursor, 0x00);
			bytes += create_packet_b(raw_data, &cursor, hellobyte);
			bytes_expected = 48;
			break;
		case QQ_FILE_CMD_PING:
		case QQ_FILE_CMD_PONG:
		case QQ_FILE_CMD_NOTIFY_IP_ACK:
			bytes += qq_fill_conn_info(raw_data, &cursor, info);
			bytes_expected = 61;
			break;
		default:
			purple_debug(PURPLE_DEBUG_INFO, "QQ", "qq_send_file_ctl_packet: Unknown packet type[%d]\n",
					packet_type);
			bytes_expected = 0;
	}
	
	if (bytes == bytes_expected) {
		gchar *hex_dump = hex_dump_to_str(raw_data, bytes);
		purple_debug(PURPLE_DEBUG_INFO, "QQ", "sending packet[%s]: \n%s", qq_get_file_cmd_desc(packet_type), hex_dump);
		g_free(hex_dump);
		encrypted_len = bytes + 16;
		encrypted_data = g_newa(guint8, encrypted_len);
		qq_crypt(ENCRYPT, raw_data, bytes, info->file_session_key, encrypted_data, &encrypted_len);
		/*debug: try to decrypt it */
		/*
		if (QQ_DEBUG) {
			guint8 *buf;
			int buflen;
			hex_dump = hex_dump_to_str(encrypted_data, encrypted_len);
			purple_debug(PURPLE_DEBUG_INFO, "QQ", "encrypted packet: \n%s", hex_dump);
			g_free(hex_dump);
			buf = g_newa(guint8, MAX_PACKET_SIZE);
			buflen = encrypted_len;
			if (qq_crypt(DECRYPT, encrypted_data, encrypted_len, info->file_session_key, buf, &buflen)) {
				purple_debug(PURPLE_DEBUG_INFO, "QQ", "decrypt success\n");
				if (buflen == bytes && memcmp(raw_data, buf, buflen) == 0)
					purple_debug(PURPLE_DEBUG_INFO, "QQ", "checksum ok\n");
				hex_dump = hex_dump_to_str(buf, buflen);
				purple_debug(PURPLE_DEBUG_INFO, "QQ", "decrypted packet: \n%s", hex_dump);
				g_free(hex_dump);
			} else {
				purple_debug(PURPLE_DEBUG_INFO, "QQ", "decrypt fail\n");
			}
		}
		*/

		purple_debug(PURPLE_DEBUG_INFO, "QQ", "<== send %s packet\n", qq_get_file_cmd_desc(packet_type));
		_qq_send_file(gc, encrypted_data, encrypted_len, QQ_FILE_CONTROL_PACKET_TAG, info->to_uid);
	}
	else
		purple_debug(PURPLE_DEBUG_ERROR, "QQ", "qq_send_file_ctl_packet: Expected to get %d bytes, but get %d",
				bytes_expected, bytes);
}

/* send a file to udp channel with QQ_FILE_DATA_PACKET_TAG */
static void _qq_send_file_data_packet(PurpleConnection *gc, guint16 packet_type, guint8 sub_type, 
		guint32 fragment_index, guint16 seq, guint8 *data, gint len)
{
	gint bytes;
	guint8 *raw_data, *cursor, filename_md5[QQ_KEY_LENGTH], file_md5[QQ_KEY_LENGTH];
	guint32 fragment_size = 1000;
	gchar *filename;
	gint filename_len, filesize;
	qq_data *qd;
	ft_info *info;

	qd = (qq_data *) gc->proto_data;
	info = (ft_info *) qd->xfer->data;

	filename = (gchar *) purple_xfer_get_filename(qd->xfer);
	filesize = purple_xfer_get_size(qd->xfer);

	raw_data = g_newa(guint8, MAX_PACKET_SIZE);
	cursor = raw_data;
	bytes = 0;

	bytes += create_packet_b(raw_data, &cursor, 0x00);
	bytes += create_packet_w(raw_data, &cursor, packet_type);
	switch (packet_type) {
		case QQ_FILE_BASIC_INFO:
		case QQ_FILE_DATA_INFO:
		case QQ_FILE_EOF:
			bytes += create_packet_w(raw_data, &cursor, 0x0000);
			bytes += create_packet_b(raw_data, &cursor, 0x00);
			break;
		case QQ_FILE_CMD_FILE_OP:
			switch(sub_type)
			{
				case QQ_FILE_BASIC_INFO: