我想用raw socket发送一个字符串，这个字符串填在哪里？
是填在tcp头的“选项”里吗？

if((sockfd = socket(AF_INET,SOCK_RAW,IPPROTO_UDP))id = htons(getpid());
        ip_header->ttl = ttl; /* #define IPTTL 60;*/
        ip_header->protocol = protocol;
        ip_header->saddr = saddr.s_addr;
        ip_header->daddr = daddr.s_addr;
        ip_header->check = 0;
        ip_header->check = ((unsigned short)ip_cksum1((unsigned short *)ip_header,sizeof(struct iphdr)));
        return;
}







void build_udphdr(char *packet,unsigned short sport,unsigned short dport,unsigned short length)
{
        struct udphdr *udp;
        char *packetck = NULL;

        udp = (struct udphdr *)packet;
        udp->source = htons(sport);
        udp->dest = htons(dport);
        udp->len = htons(length);
        udp->check = 0;

        packetck = (char*)malloc(8 + sizeof(struct pseudoudp) + length - sizeof(struct udphdr));
        memset(packetck, 0, 8 + length - sizeof(struct udphdr) + sizeof(struct pseudoudp));
        psudp = (struct pseudoudp *) (packetck);
        psudp->ipdest = 0xffffffff;
        psudp->ipsource = 0;
        psudp->zero = 0;
        psudp->proto = 17;
        psudp->length = htons(8+length-sizeof(struct udphdr));
        memcpy(packetck+sizeof(struct pseudoudp), &udp, 8);
        printf("%d %drn", length, sizeof(struct udphdr));
        //memcpy(packetck+sizeof(struct pseudoudp)+8, (char*)(packet+sizeof(struct udphdr)), length-sizeof(struct udphdr));

        udp->check = 0;
        //udp->check = udp_cksum((u_short *)packetck, 8 + length - sizeof(struct udphdr) + sizeof(struct pseudoudp));
        //udp->check = (tcp_check1(packet, length, htonl(inet_addr("61.235.102.98")), htonl(inet_addr ("202.100.4.15"))));
}


这也是当时一个人的问题 帮他调了调 能用
你参考吧

http://bricks.diy.myrice.com/linux/program/raw-socket.txt

楼上的废话！