| 1 | #define _DEFAULT_SOURCE 1 |
| 2 | #define _POSIX_C_SOURCE 200809L |
| 3 | #define _XOPEN_SOURCE 700 |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <endian.h> |
| 7 | #include <unistd.h> |
| 8 | #include <stdint.h> |
| 9 | #include <arpa/inet.h> |
| 10 | #include <sys/ioctl.h> |
| 11 | #include <string.h> |
| 12 | #include <net/if_arp.h> |
| 13 | |
| 14 | uint64_t arp_ip2mac(const char *dev, const char *ip) { |
| 15 | int ret; |
| 16 | struct arpreq arpreq; |
| 17 | int iArpFD; |
| 18 | |
| 19 | struct sockaddr_in *sin = (struct sockaddr_in *) &arpreq.arp_pa; |
| 20 | uint64_t mac = 0; |
| 21 | |
| 22 | memset(&arpreq, 0, sizeof(struct arpreq)); |
| 23 | |
| 24 | strcpy(arpreq.arp_dev, dev); |
| 25 | //sprintf(arpreq.arp_dev, "eth-pub.%d", vlan); |
| 26 | |
| 27 | iArpFD = socket(AF_INET, SOCK_DGRAM, 0); |
| 28 | if (iArpFD == -1) |
| 29 | { |
| 30 | printf("Cannot open packet socket"); |
| 31 | return 0; |
| 32 | } |
| 33 | |
| 34 | struct timeval tv = { |
| 35 | .tv_sec = 0, |
| 36 | .tv_usec = 200000 |
| 37 | }; |
| 38 | setsockopt(iArpFD, SOL_SOCKET, SO_RCVTIMEO,&tv,sizeof(struct timeval)); |
| 39 | |
| 40 | sin->sin_family = AF_INET; |
| 41 | sin->sin_addr.s_addr = inet_addr(ip); |
| 42 | sin->sin_port = htons(4242); |
| 43 | |
| 44 | sendto(iArpFD, "PING", 4, MSG_NOSIGNAL, |
| 45 | (struct sockaddr*) sin, sizeof(struct sockaddr_in)); |
| 46 | |
| 47 | |
| 48 | char blah[5]; |
| 49 | if(recvfrom(iArpFD, blah, sizeof(blah), 0, |
| 50 | (struct sockaddr *) sin, (socklen_t * restrict) sizeof(struct sockaddr)) < 0) |
| 51 | { |
| 52 | //printf("UDP ping timeout\n"); |
| 53 | } |
| 54 | |
| 55 | ret = ioctl(iArpFD, SIOCGARP, &arpreq); |
| 56 | close(iArpFD); |
| 57 | |
| 58 | if(ret < 0) { |
| 59 | printf("RET: %d FAMILY: %d\n", ret, arpreq.arp_ha.sa_family); |
| 60 | perror("SIOCGARP"); |
| 61 | return 0; |
| 62 | } |
| 63 | |
| 64 | memcpy(&mac, &arpreq.arp_ha.sa_data[0], 6); |
| 65 | mac = be64toh(mac<<16); |
| 66 | |
| 67 | return mac; |
| 68 | } |
| 69 | |
| 70 | int main() { |
| 71 | char *dev = "eth0"; |
| 72 | char *ip = "10.10.161.3"; |
| 73 | uint64_t mac = arp_ip2mac(dev, ip); |
| 74 | |
| 75 | printf("DEV %s IP %s MAC: %.12lX %s\n", dev, ip, mac, mac?"OK":"FAIL"); |
| 76 | } |
| 77 | |