链路层原始套接字编程-服务端

来源：互联网发布：javascript实例书籍编辑：程序博客网时间：2024/06/01 22:39
#include <stdio.h>#include <string.h>#include <errno.h>#include <sys/types.h> #include <sys/socket.h>#include <netpacket/packet.h>#include <net/if.h>#include <net/if_arp.h>#include <sys/ioctl.h>#define LEN     60void print_str16(unsigned char buf[], size_t len){        int     i;        unsigned char   c;        if(buf == NULL || len <= 0)                return;        for(i=0; i<len; i++){                c = buf[i];                printf("%02x", c);        }        printf("\n");}void print_sockaddr_ll(struct sockaddr_ll *sa){        if(sa == NULL)                return;        printf("sll_family:%d\n", sa->sll_family);        printf("sll_protocol:%#x\n", ntohs(sa->sll_protocol));        printf("sll_ifindex:%#x\n", sa->sll_ifindex);        printf("sll_hatype:%d\n", sa->sll_hatype);        printf("sll_pkttype:%d\n", sa->sll_pkttype);        printf("sll_halen:%d\n", sa->sll_halen);        printf("sll_addr:"); print_str16(sa->sll_addr, sa->sll_halen);}int main(){        int             result=0, fd, n, count=0;        char    buf[LEN];        struct sockaddr_ll      sa, sa_recv;        struct ifreq    ifr;        socklen_t       sa_len=0;        char    if_name[]="eth1";        memset(&sa, 0, sizeof(sa));        sa.sll_family = PF_PACKET;        sa.sll_protocol = htons(0x8902);        //create socket        fd = socket(PF_PACKET, SOCK_RAW, htons(0x8902));        if(fd < 0){                perror("socket error\n");                return errno;        }        // get flags         strcpy(ifr.ifr_name, if_name);        result = ioctl(fd, SIOCGIFFLAGS, &ifr);        if(result != 0){                 perror("ioctl error, get flags\n");                return errno;        }               ifr.ifr_flags |= IFF_PROMISC;        // set promisc mode        result = ioctl(fd, SIOCSIFFLAGS, &ifr);        if(result != 0){                perror("ioctl error, set promisc\n");                return errno;        }        //get index        result = ioctl(fd, SIOCGIFINDEX, &ifr);        if(result != 0){                perror("ioctl error, get index\n");                return errno;        }        sa.sll_ifindex = ifr.ifr_ifindex;        //bind fd        result = bind(fd, (struct sockaddr*)&sa, sizeof(struct sockaddr_ll));        if(result != 0){                perror("bind error\n");                return errno;        }        //recvfrom        while(1){                memset(buf, 0, sizeof(buf));                n = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *)&sa_recv, &sa_len);                if(n < 0){                        printf("sendto error, %d\n", errno);                        return errno;                }                printf("******************* recvfrom msg %d ****************\n", ++count);                print_str16(buf, n);                print_sockaddr_ll(&sa_recv);                printf("sa_len:%d\n", sa_len);        }        return 0;}
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