/************************************************************************* > File Name : telnet_proxy.c > Author : TL Song > EMail : songtianlun@frytea.com > Created Time : Thu Feb 18 18:57:20 2021 ************************************************************************/ #include #include // #include #include #define RECV_SEND_DEVICE "eth1" #define RETU_DEVICE "linux_dal" #define RETU_SEND_DEVICE RECV_DEVICE #define RECV_FILTER "src host 192.168.8.123 and arp or icmp or dst port 23" #define RETU_FILTER "" // switch, 1、定义后以多进程模式运行；2、定义后为抓到的包追加vlan标签。 // #define RUNNING_WITH_MULT_PROGRESS 0 // #define GREP_WITH_MAKE_VLAN 0 #define SNAP_LEN 65536 #ifndef GREP_WITH_MAKE_VLAN #define RECV_DEVICE "eth0" #else #define RECV_DEVICE "eth0.3000" #endif static char g_vlan_tag[4] = {0x81, 0x00, 0x0B, 0xB8}; #define dPrint(fmt, ...) do{fprintf(stderr, "[%s:%d] " fmt "\r\n", __FUNCTION__, __LINE__, ##__VA_ARGS__);}while(0) #define HexPrint(_buf, _len) \ {\ int _m_i = 0;\ char *_m_buf = (char *)(_buf);\ int _m_len = (int)(_len);\ printf("[%s:%d] \r\n", __FUNCTION__, __LINE__);\ printf("*****************************\n");\ for(_m_i = 0; _m_i < _m_len; _m_i++)\ {\ printf("\033[32m%02x \033[0m", _m_buf[_m_i] & 0xff);\ if(!((_m_i+1) % 10)) printf("\n");\ }\ printf("\nsize = %d\n*****************************\n", _m_len);\ } char err_buf[PCAP_ERRBUF_SIZE]; struct bpf_program fp_recv; /* The compiled filter expression */ struct bpf_program fp_retu; /* The compiled filter expression */ char filter_recv[] = RECV_FILTER; /* The filter expression (filter 53 port)*/ char filter_retu[] = RETU_FILTER; /* The filter expression (filter 53 port)*/ pcap_t *handle_recv; pcap_t *handle_retu; pcap_t *handle_recv_send; bpf_u_int32 mask_recv; /* The netmask of our sniffing device */ bpf_u_int32 mask_retu; /* The netmask of our sniffing device */ bpf_u_int32 net_recv; /* The IP of our sniffing device */ bpf_u_int32 net_retu; /* The IP of our sniffing device */ void recv_dispatcher_handler(u_char *temp1, const struct pcap_pkthdr *header, const u_char *pkt_data) { // HexPrint((const char *)pkt_data, header->caplen); #ifndef GREP_WITH_MAKE_VLAN u_char pkt_send[header->caplen]; memset(pkt_send, 0x00, sizeof(pkt_send)); memcpy(pkt_send, pkt_data, header->caplen); #else u_char pkt_send[header->caplen + sizeof(g_vlan_tag)]; memset(pkt_send, 0x00, sizeof(pkt_send)); memcpy(pkt_send, pkt_data, header->caplen); memcpy(pkt_send+16, pkt_send+12, header->caplen-12); memcpy(pkt_send+12, g_vlan_tag, sizeof(g_vlan_tag)); #endif // HexPrint((const char *)pkt_send, sizeof(pkt_send)); dPrint("Send to %s ret : %d", RECV_SEND_DEVICE, pcap_sendpacket(handle_recv_send, pkt_send, sizeof(pkt_send)) ); } void retu_dispatcher_handler(u_char *temp1, const struct pcap_pkthdr *header, const u_char *pkt_data) { // HexPrint((const char *)pkt_data, header->caplen); u_char pkt_send[header->caplen]; memset(pkt_send, 0x00, sizeof(pkt_send)); memcpy(pkt_send, pkt_data, header->caplen); // HexPrint((const char *)pkt_send, sizeof(pkt_send)); dPrint("Send to %s ret : %d", RECV_DEVICE, pcap_sendpacket(handle_recv, pkt_send, sizeof(pkt_send)) ); } // 接收前面板 eth0 发来的消息，转发到 eth1 void *recv_handl(void *args) { pcap_loop(handle_recv, -1, recv_dispatcher_handler, NULL); dPrint("Capture complete."); } // 接收 linux_dal 发来的流量，转发到 eth0 void *retu_handl(void *args) { pcap_loop(handle_retu, -1, retu_dispatcher_handler, NULL); dPrint("Capture complete."); } int main() { pthread_t tid_retu; printf("Recv Device: %s\n", RECV_DEVICE); printf("Retu Device: %s\n", RETU_DEVICE); printf("Recv Send Device: %s\n", RECV_SEND_DEVICE); printf("Retu Send Device: %s\n", RETU_SEND_DEVICE); /*get network mask*/ if (pcap_lookupnet(RECV_DEVICE, &net_recv, &mask_recv, err_buf) == -1) { fprintf(stderr, "Can't get netmask for device %s\n", RECV_DEVICE); net_recv = 0; mask_recv = 0; } if (pcap_lookupnet(RETU_DEVICE, &net_retu, &mask_retu, err_buf) == -1) { fprintf(stderr, "Can't get netmask for device %s\n", RETU_DEVICE); net_retu = 0; mask_retu = 0; } /*Open the session in promiscuous mode*/ handle_recv = pcap_open_live(RECV_DEVICE, BUFSIZ, 1, 1000, err_buf); if (handle_recv == NULL) { fprintf(stderr, "Couldn't open device %s: %s\n", RECV_DEVICE, err_buf); return; } handle_recv_send = pcap_open_live(RECV_SEND_DEVICE, SNAP_LEN, 1, 1000, err_buf); if (handle_recv_send == NULL) { fprintf(stderr, "Couldn't open device %s: %s\n", RECV_SEND_DEVICE, err_buf); return 0; } handle_retu = pcap_open_live(RETU_DEVICE, BUFSIZ, 1, 1000, err_buf); if (handle_retu == NULL) { fprintf(stderr, "Couldn't open device %s: %s\n", RETU_DEVICE, err_buf); return; } /* Compile and apply the filter */ if (pcap_compile(handle_recv, &fp_recv, filter_recv, 0, net_recv) == -1) { fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_recv, pcap_geterr(handle_recv)); return; } if (pcap_compile(handle_retu, &fp_retu, filter_retu, 0, net_retu) == -1) { fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_retu, pcap_geterr(handle_retu)); return; } if (pcap_setfilter(handle_recv, &fp_recv) == -1) { fprintf(stderr, "Couldn't install filter %s: %s\n", filter_recv, pcap_geterr(handle_recv)); return; } if (pcap_setfilter(handle_retu, &fp_retu) == -1) { fprintf(stderr, "Couldn't install filter %s: %s\n", filter_retu, pcap_geterr(handle_retu)); return; } #ifndef RUNNING_WITH_MULT_PROGRESS int ret = pthread_create(&tid_retu, NULL, retu_handl, NULL); if (ret != 0) { printf("pthread_create error: error_code = %d\n", ret); } recv_handl(NULL); pthread_exit(NULL); #else pid_t fpid=fork(); if(fpid==0) { retu_handl(NULL); printf("son/n"); } else { recv_handl(NULL); printf("father/n"); } #endif /* cleanup */ pcap_freecode(&fp_recv); pcap_close(handle_recv); pcap_freecode(&fp_retu); pcap_close(handle_retu); dPrint("Capture complete."); return 0; }