1 /**
  2  * @file arp_request.c
  3  */
  4 
  5 #include <stdio.h>
  6 #include <stdlib.h>
  7 #include <string.h>
  8 #include <unistd.h>
  9 #include <sys/ioctl.h>
 10 #include <sys/socket.h>
 11 #include <arpa/inet.h>
 12 #include <netinet/in.h>
 13 #include <netinet/if_ether.h>
 14
 
 #include <net/ethernet.h>
 15 #include <net/if_arp.h>
 16 #include <net/if.h>
 17 #include <netpacket/packet.h>
 18 
 19 /* 乙太網幀首部長度 */
 20 #define ETHER_HEADER_LEN sizeof(struct ether_header)
 21 /* 整個arp結構長度 */
 22 #define ETHER_ARP_LEN sizeof(struct ether_arp)
 23 /* 乙太網 + 整個arp結構長度 
 
*/
 24 #define ETHER_ARP_PACKET_LEN ETHER_HEADER_LEN + ETHER_ARP_LEN
 25 /* IP地址長度 */
 26 #define IP_ADDR_LEN 4
 27 /* 廣播地址 */
 28 #define BROADCAST_ADDR {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
 29 
 30 void err_exit(const char *err_msg)
 31 {
 32     perror(err_msg);
 33     exit(1);
 34 }
 35 
 36 /* 填充arp包 */
 37
 
 struct ether_arp *fill_arp_packet(const unsigned char *src_mac_addr, const char *src_ip, const char *dst_ip)
 38 {
 39     struct ether_arp *arp_packet;
 40     struct in_addr src_in_addr, dst_in_addr;
 41     unsigned char dst_mac_addr[ETH_ALEN] = BROADCAST_ADDR;
 42 
 43     /* IP地址轉換 */
 44     inet_pton(AF_INET, src_ip, &src_in_addr);
 45     inet_pton(AF_INET, dst_ip, &dst_in_addr);
 46 
 47     /* 整個arp包 */
 48     arp_packet = (struct ether_arp *)malloc(ETHER_ARP_LEN);
 49     arp_packet->arp_hrd = htons(ARPHRD_ETHER);
 50     arp_packet->arp_pro = htons(ETHERTYPE_IP);
 51     arp_packet->arp_hln = ETH_ALEN;
 52     arp_packet->arp_pln = IP_ADDR_LEN;
 53     arp_packet->arp_op = htons(ARPOP_REQUEST);
 54     memcpy(arp_packet->arp_sha, src_mac_addr, ETH_ALEN);
 55     memcpy(arp_packet->arp_tha, dst_mac_addr, ETH_ALEN);
 56     memcpy(arp_packet->arp_spa, &src_in_addr, IP_ADDR_LEN);
 57     memcpy(arp_packet->arp_tpa, &dst_in_addr, IP_ADDR_LEN);
 58 
 59     return arp_packet;
 60 }
 61 
 62 /* arp請求 */
 63 void arp_request(const char *if_name, const char *dst_ip)
 64 {
 65     struct sockaddr_ll saddr_ll;
 66     struct ether_header *eth_header;
 67     struct ether_arp *arp_packet;
 68     struct ifreq ifr;
 69     char buf[ETHER_ARP_PACKET_LEN];
 70     unsigned char src_mac_addr[ETH_ALEN];
 71     unsigned char dst_mac_addr[ETH_ALEN] = BROADCAST_ADDR;
 72     char *src_ip;
 73     int sock_raw_fd, ret_len, i;
 74 
 75     if ((sock_raw_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ARP))) == -1)
 76         err_exit("socket()");
 77 
 78     bzero(&saddr_ll, sizeof(struct sockaddr_ll));
 79     bzero(&ifr, sizeof(struct ifreq));
 80     /* 網絡卡介面名 */
 81     memcpy(ifr.ifr_name, if_name, strlen(if_name));
 82 
 83     /* 獲取網絡卡介面索引 */
 84     if (ioctl(sock_raw_fd, SIOCGIFINDEX, &ifr) == -1)
 85         err_exit("ioctl() get ifindex");
 86     saddr_ll.sll_ifindex = ifr.ifr_ifindex;
 87     saddr_ll.sll_family = PF_PACKET;
 88 
 89     /* 獲取網絡卡介面IP */
 90     if (ioctl(sock_raw_fd, SIOCGIFADDR, &ifr) == -1)
 91         err_exit("ioctl() get ip");
 92     src_ip = inet_ntoa(((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr);
 93     printf("local ip:%s\n", src_ip);
 94 
 95     /* 獲取網絡卡介面MAC地址 */
 96     if (ioctl(sock_raw_fd, SIOCGIFHWADDR, &ifr))
 97         err_exit("ioctl() get mac");
 98     memcpy(src_mac_addr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
 99     printf("local mac");
100     for (i = 0; i < ETH_ALEN; i++)
101         printf(":%02x", src_mac_addr[i]);
102     printf("\n");
103 
104     bzero(buf, ETHER_ARP_PACKET_LEN);
105     /* 填充以太首部 */
106     eth_header = (struct ether_header *)buf;
107     memcpy(eth_header->ether_shost, src_mac_addr, ETH_ALEN);
108     memcpy(eth_header->ether_dhost, dst_mac_addr, ETH_ALEN);
109     eth_header->ether_type = htons(ETHERTYPE_ARP);
110     /* arp包 */
111     arp_packet = fill_arp_packet(src_mac_addr, src_ip, dst_ip);
112     memcpy(buf + ETHER_HEADER_LEN, arp_packet, ETHER_ARP_LEN);
113 
114     /* 傳送請求 */
115     ret_len = sendto(sock_raw_fd, buf, ETHER_ARP_PACKET_LEN, 0, (struct sockaddr *)&saddr_ll, sizeof(struct sockaddr_ll));
116     if ( ret_len > 0)
117         printf("sendto() ok!!!\n");
118 
119     close(sock_raw_fd);
120 }
121 
122 int main(int argc, const char *argv[])
123 {
124     if (argc != 3)
125     {
126         printf("usage:%s device_name dst_ip\n", argv[0]);
127         exit(1);
128     }
129 
130     arp_request(argv[1], argv[2]);
131     
132     return 0;
133 }