1 #include <stdio.h>  2 #include <unistd.h>  3 #include <linux/if_ether.h>  4 #include <linux/ip.h>  5 #include <linux/udp.h>  6 #include <linux/types.h>  7   8 void show_mac(const unsigned char *data);  9 void show_ip(const unsigned char *data); 10 void show_arp(const unsigned char *data); 11 void show_udp(const unsigned char *data); 12 void show_tcp(const unsigned char *data); 13 void show_app(const unsigned char *data); 14  15 int main() 16 { 17         unsigned char data[1024] = { 18         0x00, 0x26, 0xc6, 0x41, 0x06, 0xb2, 0x00, 0x26, 19         0xc6, 0x39, 0x8c, 0x36, 0x08, 0x00, 0x45, 0x00, 20         0x00, 0x20, 0x00, 0x00, 0x40, 0x00, 0x40, 0x11, 21         0x7a, 0x90, 0xc0, 0xa8, 0x1f, 0x72, 0xc0, 0xa8, 22         0x1f, 0x7a, 0x94, 0x2b, 0x25, 0x37, 0x00, 0x0c, 23         0xa0, 0x6d, 0x77, 0x61, 0x6e, 0x67 24         }; 25  26         show_mac(data); 27 28 } 29  30 void show_mac(const unsigned char *data) 31 { 32         struct ethhdr *eth = (struct ethhdr *)data; 33         printf("-------------物理层-------------\n"); 34         printf("目的MAC地址:  %02x:%02x:%02x:%02x:%02x:%02x\n", 35                 eth->h_dest[0], eth->h_dest[1], 36                 eth->h_dest[2], eth->h_dest[3], 37                 eth->h_dest[4], eth->h_dest[5] 38                 ); 39         printf("源端MAC地址:  %02x:%02x:%02x:%02x:%02x:%02x\n", 40                 eth->h_source[0], eth->h_source[1], 41                 eth->h_source[2], eth->h_source[3], 42                 eth->h_source[4], eth->h_source[5] 43                 ); 44         printf("使用的协议:   %04x\n\n", ntohs(eth->h_proto)); 45         if(ntohs(eth->h_proto) == 0x0800) 46         show_ip(data); 47         if(ntohs(eth->h_proto) == 0x0806) 48         show_arp(data); 49 } 50 void show_ip(const unsigned char *data) 51 { 52         printf("-------------网络层-------------\n");53  54         struct iphdr *ip = (struct iphdr *)(data + sizeof(struct ethhdr)); 55         printf("版本号:       %d\n", ip->version); 56         printf("IP首部长度:   %d\n", (ip->ihl)*4); 57         printf("服务类型:     %d\n", ip->tos); 58         printf("总长度:       %d\n", ntohs(ip->tot_len)); 59         printf("标识:         %d\n", ip->id); 60         printf("片偏移:       %d\n", ip->frag_off); 61         printf("生存时间:     %d\n", ip->ttl); 62         printf("上层使用协议: %d\n", ip->protocol); 63         printf("首部检验和:   %d\n", ip->check); 64         printf("源IP地址:     %s\n", inet_ntoa(ip->saddr)); 65         printf("目的IP地址:   %s\n\n", inet_ntoa(ip->daddr)); 66         if(ip->protocol == 6) 67         show_tcp(data); 68         if(ip->protocol == 17) 69         show_udp(data); 70 } 71 void show_arp(const unsigned char *data) 72 { 73  74 } 75 void show_udp(const unsigned char *data)76 { 77         printf("-------------传输层-------------\n"); 78         struct udphdr *udp = (struct udphdr *)(data + sizeof(struct ethhdr)+ sizeof(struct iphdr)); 79         printf("源端口号:     %d\n", htons(udp->source)); 80         printf("目的端口号:   %d\n", htons(udp->dest)); 81         printf("UDP长度:      %d\n", htons(udp->len)); 82         printf("UDP检验和:    %x\n\n", htons(udp->check)); 83         show_app(data); 84 } 85 void show_tcp(const unsigned char *data) 86 { 87  88 } 89 void show_app(const unsigned char *data) 90 { 91         printf("-------------应用层-------------\n"); 92         char *p = (char *)(data + sizeof(struct ethhdr)+ sizeof(struct iphdr)+sizeof(struct udphdr)); 93         printf("数据:%s\n\n", p); 94  95 }