我编写了这个程序来在 eth0 上发送和接收来自 ipv6 的数据包：
#include<sys/socket.h>
#include<sys/types.h>
#include <netinet/in.h>
#include <stdio.h>
#include <netdb.h>
#include <errno.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
int main() {
int sock,i;
struct sockaddr_in6 *address;
struct protoent *proto;
struct ifreq ethreq, Interface, Interface1;
unsigned char buffer[2048];
unsigned char tbuff[2048];
unsigned char *iphead, *ethhead,*phead;
static const uint8_t mys6_addr[16]={0x54,0x04,0x20,0x49,0x0e,0x40,0xc7,0x03,0xa0};
//open socket for receive ipv6 packet
sock=socket(AF_INET6, SOCK_RAW,255);
//control error
if(sock<0) {
perror("socket");
exit(1);
}
strncpy(ethreq.ifr_name, "eth0", IFNAMSIZ);
if (ioctl(sock,SIOCGIFFLAGS, ðreq) == -1) {
perror("ioctl");
close(sock);
exit(1);
}
ethreq.ifr_flags |= IFF_PROMISC;
if (ioctl(sock, SIOCSIFFLAGS, ðreq) == -1) {
perror("ioctl");
close(sock);
exit(1);
}
//bind to sock with eth0
memset(&Interface, 0, sizeof(Interface));
strncpy(Interface.ifr_ifrn.ifrn_name, "eth0", IFNAMSIZ);
if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, &Interface, sizeof(Interface))<0)
close(sock);
//open the RAW socket for sendto
int s = socket (AF_INET6, SOCK_RAW, 255);
struct sockaddr_in6 sin6;
memset(&sin6,0,sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_port = htons(0);
memcpy(sin6.sin6_addr.s6_addr, mys6_addr, sizeof(mys6_addr));
//bind the sock descriptor with eth0
memset(&Interface1, 0, sizeof(Interface1));
strncpy(Interface1.ifr_ifrn.ifrn_name, "eth0", IFNAMSIZ);
if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, &Interface1, sizeof(Interface1)) < 0) {
close(s);
}
while (1) {
printf("----------------------\n");
i = recv(sock, buffer, sizeof(buffer), 0);
printf("%d bytes read\n", i);
// check header size: Ethernet = 14, IP = 20, TCP = 8 (sum = 42)
i=43;
if (i < 42) {
perror("recvfrom():");
printf("Incomplete packet (errno is %d)\n", errno);
close(sock);
exit(0);
}
phead = buffer + 14; // (skip ethernet header)
memcpy(tbuff,phead,i-14);
iphead=tbuff;
if (*iphead == 0x45) {
int ptrindex= iphead[9];
switch(ptrindex){
case 1:
printf("The transport protocl is:ICMP\n");
break;
case 2:
printf("The transport protol is:IGMP\n");
break;
case 6:
printf("The transport protocol is:TCP\n");
break;
case 17:
printf("The transport protocol is:UDP\n");
break;
case 103:
printf("The transport protocol is:PIM\n");
break;
default:
printf("The transport protocol is:%d\n",iphead[9]);
}
//printf("%d",*ptrindex);
// printf("\n The transport protocol is :%u\n",iphead[9]);
printf("Source Address: %d.%d.%d.%d, Port: %d\n",
iphead[12], iphead[13], iphead[14], iphead[15], (iphead[20] << 8) + iphead[21]);
printf("Dest Address: %d.%d.%d.%d, Port: %d\n",
iphead[16], iphead[17], iphead[18], iphead[19], (iphead[22] << 8) + iphead[23]);
/* if(sendto(s,tbuff,i-14,0,(struct sockaddr_in6 *)&sin6,sizeof(sin6))<0)
printf("error\n"); */
if(send(s,tbuff,i-14,0)<0) {
printf("error\n");
} else {
printf("\nThe received packet is send\n");
}
memset(buffer,0,sizeof(buffer));
memset(tbuff,0,sizeof(tbuff));
} else{
printf("The non ip had received");
}
}
close(sock);
return 0;
}
大部分代码是我读过的问题的一部分，但现在我不记得是什么了。该程序在 printf("----------------\n") 处陷入死锁。为什么？你能帮助我吗？