rarp.rar_rarp_run

//File Name : rarp_server.cpp extern "C" { #include <sys/types.h> #include <sys/time.h> #include <time.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/if_ether.h> #include <net/if_arp.h> #include <netinet/in.h> #include <stdio.h> #include <string.h> #include <unistd.h> #include <errno.h> #include <netinet/if_ether.h> #include <net/if_arp.h> #include <net/if.h> #include <netinet/in.h> #include <arpa/inet.h> #include <sys/ioctl.h> #include <netpacket/packet.h> } #include <cstdlib> /* args: yiaddr - what IP to ping * ip - our ip * mac - our arp address * interface - interface to use * retn: 1 addr free * 0 addr used * -1 error */ /* FIXME: match response against chaddr */ struct arpMsg { struct ethhdr ethhdr; /* Ethernet header */ u_short htype; /* hardware type (must be ARPHRD_ETHER) */ u_short ptype; /* protocol type (must be ETH_P_IP) */ u_char hlen; /* hardware address length (must be 6) */ u_char plen; /* protocol address length (must be 4) */ u_short operation; /* ARP opcode */ u_char sHaddr[6]; /* sender's hardware address */ u_char sInaddr[4]; /* sender's IP address */ u_char tHaddr[6]; /* target's hardware address */ u_char tInaddr[4]; /* target's IP address */ u_char pad[18]; /* pad for min. Ethernet payload (60 bytes) */ }; /* miscellaneous defines */ #define MAC_BCAST_ADDR (uint8_t *) "\xff\xff\xff\xff\xff\xff" #define OPT_CODE 0 #define OPT_LEN 1 #define OPT_DATA 2 struct interface_info { char ifname[64]; unsigned char ip[4]; unsigned char mac[6]; }; struct interface_info if_info[10]; int eth_num = 0; void print_mac(unsigned char * mac_addr) { for (int i =0; i < 6; ++i) { printf("%02X", mac_addr[i]); if (i != 5) printf(":"); } printf("\n"); } void print_ip(unsigned char * ip_addr) { for (int i =0; i < 4; ++i) { printf("%d", ip_addr[i]); if (i != 3) printf("."); } printf("\n"); } int get_iface_index(int fd, const char* interface_name) { struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strcpy (ifr.ifr_name, interface_name); if (ioctl(fd, SIOCGIFINDEX, &ifr) == -1) { return (-1); } return ifr.ifr_ifindex; } int get_interfaces() { int sock; int len = 64; int last_len = 0; char *pBuff = NULL; int interface_num = 0; struct ifconf interface_conf; struct ifreq ifreq1; struct sockaddr_in *psockaddr_in = NULL; if ( (sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { perror("Could not create socket for geting interface info"); exit(1); } while(1) { pBuff = (char*)malloc(len); interface_conf.ifc_len = len; interface_conf.ifc_buf = pBuff; if (ioctl(sock, SIOCGIFCONF, &interface_conf) < 0) { perror("ioctl error"); } else { if (interface_conf.ifc_len == last_len) { break; } else { last_len = interface_conf.ifc_len; } } len += 2*sizeof(struct ifreq); free(pBuff); } interface_num = last_len / sizeof(struct ifreq); for (int i =0; i < interface_num; ++i) { strcpy(ifreq1.ifr_name, interface_conf.ifc_ifcu.ifcu_req[i].ifr_name); if (strcmp(ifreq1.ifr_name, "lo") == 0) { continue; } if (ioctl(sock, SIOCGIFHWADDR, &ifreq1) < 0) { continue; } memcpy(if_info[eth_num].mac, ifreq1.ifr_hwaddr.sa_data, 6); strcpy(if_info[eth_num].ifname, ifreq1.ifr_name); psockaddr_in = (struct sockaddr_in*)&interface_conf.ifc_req[i].ifr_addr; memcpy(if_info[eth_num].ip, &(psockaddr_in->sin_addr.s_addr), 4); printf("Interface name: %s", if_info[eth_num].ifname); printf(" ip address: "); print_ip(if_info[eth_num].ip); printf(" mac address:"); print_mac(if_info[eth_num].mac); eth_num++; } free(pBuff); close(sock); } int equal_mac(unsigned char* mac1, unsigned char* mac2) { for (int i =0; i < 6; ++i) { if (mac1[i] != mac2[i]) return 0; } return 1; } int main() { int timeout = 2; int optval = 1; int s; /* socket */ int rv = 1; /* return value */ struct sockaddr_ll addr; /* for interface name */ struct arpMsg arp; struct arpMsg *parp; fd_set fdset; struct timeval tm; time_t prevTime; u_int32_t ip; u_int32_t yiaddr; struct in_addr my_ip; struct in_addr dst_ip; char buff[2000]; int nLen; char szBuffer[4096]; if ((s = socket (PF_PACKET, SOCK_RAW, htons(ETH_P_RARP))) == -1) { printf("Could not open raw socket\n"); return -1; } if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval)) == -1) { printf("Could not setsocketopt on raw socket\n"); close(s); return -1; } memset(&addr, 0, sizeof(addr)); addr.sll_family = AF_PACKET; addr.sll_ifindex = get_iface_index(s, "eth0"); addr.sll_protocol = htons(ETH_P_ARP); get_interfaces(); memset(szBuffer, 0, sizeof(szBuffer)); while ((nLen = recvfrom(s, szBuffer, sizeof(szBuffer), MSG_TRUNC, NULL, NULL)) > 0) { parp = (struct arpMsg*)szBuffer; printf("The request is from "); print_ip(parp->sInaddr); for (int i = 0; i < eth_num; ++i) { if (equal_mac(if_info[i].mac, parp->tHaddr)) { /* send arp request */ memset(&arp, 0, sizeof(arp)); memcpy(arp.ethhdr.h_dest, parp->sHaddr, 6); // MAC DA memcpy(arp.ethhdr.h_source, parp->tHaddr, 6); // MAC SA arp.ethhdr.h_proto = htons(ETH_P_RARP); // protocol type (Ethernet) arp.htype = htons(ARPHRD_ETHER); // hardware type arp.ptype = htons(ETH_P_IP); // protocol type (ARP message) arp.hlen = 6; // hardware address length arp.plen = 4; // protocol address length arp.operation = htons(4); // RARP reply code memcpy(arp.sInaddr, if_info[i].ip, 4); // source IP address memcpy(arp.sHaddr, parp->tHaddr, 6); // source hardware address memcpy(arp.tInaddr, parp->sInaddr, 4); // target IP address memcpy(arp.tHaddr, parp->sHaddr, 6); if (sendto(s, &arp, sizeof(arp), 0, (struct sockaddr*)&addr, sizeof(addr)) < 0) { perror("Unabele to send arp request"); return 0; } else printf("send reply\n"); } } } close(s); return 0; }