一段端口扫描的代码，原始套接字，怎么老是recvfrom收不到呢？

scu_guzo

static int FIN_scan(const char *ip_addr, const unsigned short port) {     struct sockaddr_in addr;     int sockfd;     fd_set fdset;     struct timeval timeout;     struct tcphdr *tcp;     struct ip *ip;     char buf[sizeof(struct tcphdr) + sizeof(struct ip)];     int buflen, addrlen;     addr.sin_family = AF_INET;     addr.sin_port = htons(port);     addr.sin_addr.s_addr = inet_addr("119.75.216.30");    //119.75.216.30百度     timeout.tv_sec = TIME_OUT;     timeout.tv_usec = 0;     memset(buf, 0, sizeof(buf));     sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_TCP);     ip = (struct ip *)buf;     tcp = (struct tcphdr *)(buf + sizeof(struct ip));     buflen = sizeof(struct tcphdr) + sizeof(struct ip);     addrlen = sizeof(struct sockaddr_in);     tcp->source = htons(55555);     tcp->dest = htons(port);     tcp->fin = 1;     tcp->doff = 5;     if (sendto(sockfd, buf, buflen, 0, (struct sockaddr *)&addr, addrlen)         == buflen)         printf("sendto successn");     if (recvfrom(sockfd, buf, buflen, 0, (struct sockaddr *)&addr,          &addrlen) == buflen)         printf("recvfrom successn"); //recvfrom收不到     return 1; }

hijohnny

man sockaddr_ll

scu_guzo

嗯  谢了