diff options
Diffstat (limited to 'src/tsg_tamper.cpp')
| -rw-r--r-- | src/tsg_tamper.cpp | 132 |
1 files changed, 22 insertions, 110 deletions
diff --git a/src/tsg_tamper.cpp b/src/tsg_tamper.cpp index b3d100c..b12c4b8 100644 --- a/src/tsg_tamper.cpp +++ b/src/tsg_tamper.cpp @@ -31,6 +31,7 @@ #define IPV6_UDP_PALYLOAD_START_INDEX 48 //ipv6_len(40) + udp_len(8) #define IPV6_IP_PAYLOAD_INDEX 4 //ipv6_payload_index(4) + int tamper_calc(char *str, int startlen, int endlen) { int i = 0; @@ -39,136 +40,47 @@ int tamper_calc(char *str, int startlen, int endlen) //最小交换paythod的第2个字节和第四个字节，否则不处理 if ((endlen - startlen) < 4){ - return STATE_DROPPKT; + return -1; } //start_len+1 : 因为计算校验和是16bit为单位，这里调换16bit的低8bit。 - for(i = startlen+1; i < endlen; i++){ - for (j = i+2; j < endlen; j++){ + for(i=startlen+1; i<endlen; i=i+2){ + for (j=i+2; j<endlen; j=j+2){ if(str[i] != str[j]){ temp = str[i]; str[i] = str[j]; str[j] = temp; - return STATE_GIVEME; + return 0; } } } - return STATE_DROPPKT; -} - -int stamp_calc2(char *str, int startlen, int endlen) -{ - int i = 0; - char temp; - - if(endlen - startlen < 4){ - return STATE_DROPPKT; - } - - for(i = startlen; (i < endlen) && (i+3 < endlen); i=i+4){ - printf("ii = %d \n", i); - if(str[i+1] != str[i+3]){ - temp = str[i+1]; - str[i+1] = str[i+3]; - str[i+3] = temp; - return STATE_GIVEME; - } - } - return STATE_DROPPKT; -} - -int tamper_ipv4(const char *packet, char *ret_packet, int *ret_len){ - int packet_len = 0; - int src_ipv4_total_len = 0; - char tcp_head_len; - char protocol_type = packet[IPV4_PROTOCOL_INDEX]; - int payload_start_index = 0; - int tcp_head_all_len = 0; - - //get packet_len - memcpy(&src_ipv4_total_len, &packet[IPV4_IP_LEN_INDEX], sizeof(short)); - packet_len = htons(src_ipv4_total_len); - - if(protocol_type == TCP_TYPE){ - tcp_head_len = ret_packet[IPV4_TCP_HEAD_LEN_INDEX]; - tcp_head_len = ((tcp_head_len>>4)&0x0f)*4; - tcp_head_all_len = tcp_head_len + IPV4_LEN; - if(packet_len == tcp_head_all_len){ - return -1; - } - payload_start_index = IPV4_LEN + tcp_head_len; - }else if(protocol_type == UDP_TYPE){ - if(ETH_IPV4_IP_UPD_LEN == packet_len){ - return -1; - } - payload_start_index = ETH_IPV4_IP_UPD_LEN; - } - - *ret_len = packet_len-payload_start_index+1; - memcpy(ret_packet, &packet[payload_start_index], *ret_len); - return tamper_calc(ret_packet, payload_start_index, packet_len); -} - -//int tamper_ipv6(char *packet, int packet_len){ -int tamper_ipv6(const char *packet, char *ret_packet, int *ret_len){ - int packet_len = 0; - short src_ipv6_total_len = 0; - char tcp_head_len; - char protocol_type = packet[IPV6_PROTOCOL_INDEX]; - int payload_start_index = 0; - int packet_all_len = 0; - - memcpy(&src_ipv6_total_len, &packet[IPV6_IP_PAYLOAD_INDEX], sizeof(short)); //get ipv6_payload_len - packet_len = htons(src_ipv6_total_len) + IPV6_LEN; - *ret_len = packet_len; - - if(protocol_type == TCP_TYPE){ - tcp_head_len = ret_packet[IPV6_TCP_OPTION_LEN_INDEX]; - tcp_head_len = ((tcp_head_len>>4)&0x0f)*4; - packet_all_len = tcp_head_len + IPV6_LEN; - if(packet_len == packet_all_len){ - return -1; - } - payload_start_index = IPV6_LEN + tcp_head_len; - }else if(protocol_type == UDP_TYPE){ - if(IPV6_UDP_PALYLOAD_START_INDEX == packet_len){ - return -1; - } - payload_start_index = IPV6_UDP_PALYLOAD_START_INDEX; - } - - *ret_len = packet_len-payload_start_index+1; - memcpy(ret_packet, &packet[payload_start_index], *ret_len); - return tamper_calc(ret_packet, payload_start_index, packet_len); -} - -static int format_tamper(const char *packet, char *tamper_buf, int *tamper_len, int ip_type){ - int ret = 0; - - if(IPV4_TYPE == ip_type) { - ret = tamper_ipv4((char *)packet, tamper_buf, tamper_len); - }else{ - ret = tamper_ipv6((char *)packet, tamper_buf, tamper_len); - } - - return ret; + return -1; } unsigned char send_tamper_xxx(const struct streaminfo *a_stream, const void *raw_pkt) { + const char *p_trans_payload = (char *)a_stream->ptcpdetail->pdata; + int trans_layload_len = a_stream->ptcpdetail->datalen; char tamper_buf[MTU_LEN] = {0}; unsigned char raw_route_dir = 0; - int tamper_len = 0; int ret = 0; + + if(a_stream == NULL){ + return STATE_DROPPKT; + } - ret = format_tamper((char *)raw_pkt, tamper_buf, &tamper_len, a_stream->addr.addrtype); - if (ret < 0){ + if((p_trans_payload==NULL)||(trans_layload_len<=0)||(a_stream->curdir== DIR_S2C)){ return STATE_DROPPKT; } - raw_route_dir=(a_stream->curdir==DIR_C2S) ? a_stream->routedir : MESA_dir_reverse(a_stream->routedir); - tsg_send_inject_packet(a_stream, SIO_DEFAULT, tamper_buf, tamper_len, raw_route_dir); + memcpy(tamper_buf, p_trans_payload, trans_layload_len); + ret = tamper_calc(tamper_buf, 0, trans_layload_len); + if (ret < 0){ + return STATE_DROPPKT; + } - return STATE_DROPPKT|STATE_DROPME; -} + raw_route_dir = (a_stream->curdir==DIR_C2S) ? a_stream->routedir : MESA_dir_reverse(a_stream->routedir); + tsg_send_inject_packet(a_stream, SIO_DEFAULT, tamper_buf, trans_layload_len, raw_route_dir); + return STATE_DROPPKT; +} |