原始套接字不發送

我想寫一個示例原始套接字程序來清除我對原始套接字的理解。我創建一個Raw UDP套接字，然後調用sendto。我sendto成功，但我從來沒有看到對方收到的數據包。我沒有任何接收方運行，所以我依靠在發送方和接收方上運行的Wireshark。我正在粘貼這裏的代碼片段。請指出任何錯誤。原始套接字不發送

#include<stdio.h> 
#include<stdlib.h> 
#include<sys/types.h> 
#include<netinet/in.h> 
#include<string.h> 

#include "protHeaders.x" 
#include "gen.h" 

U16 csum(U16* buf, S32 nwords) 
    { 
    U32 sum; 
    for (sum = 0; nwords > 0; nwords--) 
    sum += *buf++; 
    sum = (sum >> 16) + (sum & 0xffff); 
    sum += (sum >> 16); 


    return ~sum; 
    }/*csum*/ 

int main(int argc,char** argv) 
    { 
    U8 datagram[MAX_IPPACKET]; 
    U8 udpPayLoad[MAX_UDPPAYLOAD]; 
    CustIpHeader* ipH; 
    CustUdpHeader* udpH; 
    struct sockaddr_in sin; 
    S32 sockFd; 
    S32 one = 1; 
    const S32* val = &one; 


    ipH = (CustIpHeader *)datagram; 
    udpH = (CustUdpHeader *)(datagram + sizeof(CustIpHeader)); 

    memset(datagram,0,sizeof(datagram)); 
    memset(udpPayLoad,0,sizeof(udpPayLoad)); 
    memset(&sin,0,sizeof(struct sockaddr_in)); 

    strcpy(udpPayLoad,"<<<<Aditya>>>>"); 

    sin.sin_family = AF_INET; 
    sin.sin_port = htons(atoi(argv[4])); 

    /* fill the Ip header */ 

    ipH->ip_hl   = 5; 
    ipH->ip_v   = 4; 
    ipH->ip_tos  = 0; 
    ipH->ip_len  = sizeof(CustIpHeader) + sizeof(CustUdpHeader) + strlen(udpPayLoad); 
    ipH->ip_id   = htonl(54321); 
    ipH->ip_off  = 0; 
    ipH->ip_p   = 17; 
    ipH->ip_ttl  = 65; 
    ipH->ip_sum  = 0; 
    ipH->ip_src.s_addr = inet_addr(argv[1]); 
    ipH->ip_dst.s_addr = inet_addr(argv[3]); 

    /* fill the Udp header */ 

    udpH->uh_sport  = htons(atoi(argv[2])); 
    udpH->uh_dport  = htons(atoi(argv[4])); 
    udpH->uh_len  = sizeof(CustUdpHeader) + strlen(udpPayLoad); 
    udpH->uh_check  = 0; 

    printf("Checksum = %u\n",udpH->uh_check); 
    /* copy udpPayLoad */ 
    strcpy(datagram+sizeof(CustIpHeader)+sizeof(CustUdpHeader),udpPayLoad); 
    #if 1 
    printf("Datagram %p,UdpPayload %p\n",(void *)datagram,(void *)datagram+sizeof(CustIpHeader)+sizeof(CustUdpHeader)); 
    printf("IpHeader %p, UdpHeader %p\n",(void *)ipH,udpH); 
    #endif 

    /* fill in the checksum */ 

    ipH->ip_sum = csum((U16 *)datagram,ipH->ip_len >> 1); 

    printf("Checksum = %u\n",ipH->ip_sum); 


    if ((sockFd = socket(PF_INET,SOCK_RAW,IPPROTO_UDP)) < 0) 
     { 
     perror("socket:create"); 
     RETURN(RFAILED); 
     } 
    /* doing the IP_HDRINCL call */ 

    if (setsockopt(sockFd,IPPROTO_IP,IP_HDRINCL,val,sizeof(one)) < 0) 
    { 
     perror("Client:setsockopt"); 
    } 


    while(1) 
    { 
     if (sendto(sockFd, 
        datagram, 
        ipH->ip_len, 
        0, 
        (struct sockaddr *)&sin, 
        sizeof (sin)) < 0) 
      { perror("Client:sendto"); } 

     else 
      printf("."); 

    } 

    RETURN(ROK); 
    }

的IP和UDP報頭是：

typedef struct _ipheader 
{ 
    U8 ip_hl:4,ip_v:4; /* ip_hl: the ip header length in 32bit octets. 
         * ip_v : ip version (always 4 for our case). 
         */ 

    U8 ip_tos;   /* reliability of the service. 0x00 is Normal */ 

    U16 ip_len;  /* totoal length including ip header,icmp/tcp/udp header 
         * and payload size in bytes 
         */ 

    U16 ip_id;   /* sequence no. used for reassembly of fragmented IP packets */ 

    U16 ip_off;  /* the fragment offset used for reassembly of fragmented packets */ 

    U16 ip_p;   /* the transport layer protocol. can be tcp (6), udp(17) */ 


    U8 ip_ttl;   /* time to live */ 

    U16 ip_sum;  /* the datagram checksum for the whole IP packet */ 

    struct in_addr ip_src;  /* the source IP address, converted to a long format */ 

    struct in_addr ip_dst;  /* the desitnation IP address, converted to a long format */ 
}CustIpHeader; /* total ip header length: 20 bytes */ 



typedef struct _udpheader 
{ 

U16 uh_sport;  /* The source port that a client bind()s to */ 
U16 uh_dport;  /* The desination port that a server bind()s to*/ 
U16 uh_len;  /* The length of udp header and payload data in bytes */ 
U16 uh_check;  /* The checksum of header and data */ 

}CustUdpHeader; /* total udp header length: 8 bytes (=64 bits) */

我以根用戶身份運行，因此權限是沒有問題的。

語言：C

操作系統：Linux

來源

2009-06-24 Aditya Sehgal

我讓wireshark在慢速系統上運行。數據包確實正在發送，但Wireshark只能在6分鐘左右的時間間隔後才顯示。轉向更快的系統有所幫助。我如何關閉這個問題？ – 2009-06-24 11:11:58