/************************************************************************* > 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 SNAP_LEN 65536 // #define Make_VLAN #ifdef Make_VLAN #define RECV_DEVICE "eth0.3000" #else #define RECV_DEVICE "eth0" #endif #define RECV_SEND_DEVICE "eth1" #define RETU_DEVICE "linux_dal" #define RETU_SEND_DEVICE "eth0" #define RECV_FILTER "src host 192.168.8.123 and arp or icmp or dst port 23" #define RETU_FILTER "" 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);\ } int send_pkt_pcap(char *dev, const u_char *pkt, int len) { static pcap_t *handle = NULL; char dev_str[64]; char err_buf[PCAP_ERRBUF_SIZE]; strcpy(dev_str, dev); if(NULL == handle) { handle = pcap_open_live(dev_str, SNAP_LEN, 1, 1000, err_buf); if (handle == NULL) { fprintf(stderr, "Couldn't open device %s: %s\n", dev_str, err_buf); return 0; } } return pcap_sendpacket(handle, pkt, len); } void recv_dispatcher_handler(u_char *temp1, const struct pcap_pkthdr *header, const u_char *pkt_data) { HexPrint((const char *)pkt_data, header->caplen); #ifdef Make_VLAN 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)); #else u_char pkt_send[header->caplen]; memset(pkt_send, 0x00, sizeof(pkt_send)); memcpy(pkt_send, pkt_data, header->caplen); #endif HexPrint((const char *)pkt_send, sizeof(pkt_send)); dPrint("Send to %s ret : %d\n", RECV_SEND_DEVICE, send_pkt_pcap(RECV_SEND_DEVICE, (const u_char *)pkt_send, sizeof(pkt_send))); // sleep(1); } 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\n",RETU_SEND_DEVICE, send_pkt_pcap(RETU_SEND_DEVICE, (const u_char *)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) { char errbuf[PCAP_ERRBUF_SIZE]; struct bpf_program fp; /* The compiled filter expression */ char filter_exp[] = RECV_FILTER; /* The filter expression (filter 53 port)*/ pcap_t *handle; bpf_u_int32 mask; /* The netmask of our sniffing device */ bpf_u_int32 net; /* The IP of our sniffing device */ printf("Recv Device: %s\n", RECV_DEVICE); /*get network mask*/ if (pcap_lookupnet(RECV_DEVICE, &net, &mask, errbuf) == -1) { fprintf(stderr, "Can't get netmask for device %s\n", RECV_DEVICE); net = 0; mask = 0; } /*Open the session in promiscuous mode*/ handle = pcap_open_live(RECV_DEVICE, BUFSIZ, 1, 1000, errbuf); if (handle == NULL) { fprintf(stderr, "Couldn't open device %s: %s\n", RECV_DEVICE, errbuf); return; } /* Compile and apply the filter */ if (pcap_compile(handle, &fp, filter_exp, 0, net) == -1) { fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_exp, pcap_geterr(handle)); return; } if (pcap_setfilter(handle, &fp) == -1) { fprintf(stderr, "Couldn't install filter %s: %s\n", filter_exp, pcap_geterr(handle)); return; } pcap_loop(handle, -1, recv_dispatcher_handler, NULL); /* cleanup */ pcap_freecode(&fp); pcap_close(handle); dPrint("Capture complete."); } // 接收 linux_dal 发来的流量，转发到 eth0 void *retu_handl(void *args) { char errbuf[PCAP_ERRBUF_SIZE]; struct bpf_program fp; /* The compiled filter expression */ char filter_exp[] = RETU_FILTER; /* The filter expression (filter 53 port)*/ pcap_t *handle; bpf_u_int32 mask; /* The netmask of our sniffing device */ bpf_u_int32 net; /* The IP of our sniffing device */ printf("Recv Device: %s\n", RETU_DEVICE); /*get network mask*/ if (pcap_lookupnet(RETU_DEVICE, &net, &mask, errbuf) == -1) { fprintf(stderr, "Can't get netmask for device %s\n", RETU_DEVICE); net = 0; mask = 0; } /*Open the session in promiscuous mode*/ handle = pcap_open_live(RETU_DEVICE, BUFSIZ, 1, 1000, errbuf); if (handle == NULL) { fprintf(stderr, "Couldn't open device %s: %s\n", RETU_DEVICE, errbuf); return; } /* Compile and apply the filter */ if (pcap_compile(handle, &fp, filter_exp, 0, net) == -1) { fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_exp, pcap_geterr(handle)); return; } if (pcap_setfilter(handle, &fp) == -1) { fprintf(stderr, "Couldn't install filter %s: %s\n", filter_exp, pcap_geterr(handle)); return; } pcap_loop(handle, -1, retu_dispatcher_handler, NULL); /* cleanup */ pcap_freecode(&fp); pcap_close(handle); dPrint("Capture complete."); } int main() { int ret = 0; pthread_t tid_recv, tid_return; // pthread_attr_t attr; // pthread_attr_init(&attr); // pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); //设置线程可分离 // 创建线程，参数依次是：创建的线程id，线程参数，调用的函数，传入的函数参数 // ret = pthread_create(&tid_recv, NULL, recv_handl, NULL); // if (ret != 0) { // printf("pthread_create error: error_code = %d\n", ret); // } // ret = pthread_create(&tid_return, NULL, retu_handl, NULL); // if (ret != 0) { // printf("pthread_create error: error_code = %d\n", ret); // } // while(1) {}; // 线程分离 // pthread_exit(NULL); pid_t fpid=fork(); if(fpid==0) { retu_handl(NULL); printf("son/n"); } else { recv_handl(NULL); printf("father/n"); } return 0; }