版主帮忙!!!关于"永远的unix上"ping的源码的调试问题!

reddatura

因为我要作这个程序,
所以当了这上面的源码,
但是我发现,
发送icmp数据包后
得不到回应
这是为什么?????

但是ping本机是可以通的!!!!!!!!!!!!!!!!111
谢谢

源码如下我只改动了一点)



/* PING.C  
/*  
/* ping source code distribute by cpu || digger.  
/* for unix family only. compil and link success in sco unix.  
/* i think linux no problem too. u can try it.
/* before read this code, you shoud know about the principle of  
/* tcp/ip, especially icmp protocol, u also should also know some  
/* about BSD socket API, and unix system signal programmin/g.
/*  
/* cc -o ping ping.c -lsocket, then u will get executable file,  
/* but must act as root when cc it, and then set euid attribute  
/* for this ping, then u can execute it as common user.  
/* because only root can have authority to creat raw socket.  
/*  
/* i love socket, if so do u,  
/* call me, cpu == digger  

*/

#include <sys/types.h>;
#include <sys/socket.h>;
#include <netinet/in.h>;
#include <arpa/inet.h>;
#include <fcntl.h>;
#include <unistd.h>;
#include <stdarg.h>;
#include <stdio.h>;
#include <netdb.h>;
#include <sys/ioctl.h>;
#include <net/if.h>;
#include <stdlib.h>;
#include <stdio.h>;
#include <string.h>;
#include <signal.h>;
#include <errno.h>;

#define MAX(x,y) (x>;y)?x:y
#define MIN(x,y) (x<y)?x:y
#define ICMP_ECHO 8 /* icmp echo requir */
#define ICMP_ECHOREPLY 0 /* icmp echo reply */  
#define ICMP_HEADSIZE 8 /* icmp packet header size */  
#define IP_HEADSIZE 20 /* ip packet header size */  

typedef struct tagIpHead /* icmp packet header */  
{  
  u_char ip_verlen; /* ip version and ip header lenth*/  
  u_char ip_tos; /* ip type of service */  
  u_short ip_len; /* ip packet lenghth */  
  u_short ip_id; /* ip packet identification */  
  u_short ip_fragoff; /* ip packet fragment and offset */  
  u_char ip_ttl; /* ip packet time to live */  
  u_char ip_proto; /* ip packet protocol type */  
  u_short ip_chksum; /* ip packet header checksum */  
  u_long ip_src_addr; /* ip source ip adress */  
  u_long ip_dst_addr; /* ip destination ip adress */  
} IPHEAD;  

typedef struct tagIcmpHead /* icmp header */  
{  
  u_char icmp_type; /* icmp service type */  
  /* 8 echo require, 0 echo reply */  
  u_char icmp_code; /* icmp header code */  
  u_short icmp_chksum; /* icmp header chksum */  
  u_short icmp_id; /* icmp packet identification */  
  u_short icmp_seq; /* icmp packet sequent */  
  u_char icmp_data[1]; /* icmp data, use as pointer */  
} ICMPHEAD;  

/* for check sum of icmp header */
u_short ChkSum( u_short * pIcmpData, int iDataLen )  
{  
  u_short iSum;  
  u_short iOddByte;  

  iSum = 0;  

  while ( iDataLen >; 1 )
  { /* xor the next unsigned int data */  
    iSum ^= *pIcmpData++;  
    iDataLen -= 2;  
  }  

  if ( iDataLen == 1 )
  { /* the rest odd byte */  
    iOddByte = 0;  
    *((u_char *)&iOddByte) = *(u_char *)pIcmpData;  
    iSum ^= iOddByte;  
  }  

  iSum ^= 0xffff; /* xor 0xffff == not it */  
  return(iSum);  
}  

/* since 1970.1.1 00:00:00, */
/* in 1/1000000 second */
long time_now() /* return time passed by */  
{  
  struct timeval now;  
  long lPassed;  
  gettimeofday(&now, 0);  
  lPassed = now.tv_sec * 1000000 + now.tv_usec;  
  /* now.tv_sec in second */  
  /* now.tv_usec in 1/1000000 second */  
  return lPassed;  
}  

char* host; /* destination host */  
char* prog; /* program name */  
extern errno; /* system global parameter */  
long lSendTime; /* each time when send, change it */  
u_short seq; /* the icmp packet seqence */  
int iTimeOut; /* time out parameter */  
int sock, sent, recvd, max, min, total;  
/* sent : icmp packet already sent */  
/* recvd: proper icmp packet received */  
/* max, min: max min round trip time */  
/* total: total round trip time */  
/* store to calculate average */  
u_long lHostIp; /* host ip adress */  
struct sockaddr_in it; /* destination host information */  

int ping();  
void stat();  

main(int argc, char** argv)  
{  
  struct hostent* h;  
  char buf[200];  
  char dst_host[32];  
  int i, namelen;  
  IPHEAD* pIpHead;  
  ICMPHEAD* pIcmpHead;  

  if (argc < 2)
  {
    /* ping the destination host */  



    /* every timeout second */  
    /* default timeout is 1 second */  

    printf("usage: %s [-timeout] host|IP\n", argv[0]);  
    exit(0);  
  }  
  prog = argv[0];  
  host = argc == 2 ? argv[1] : argv[2];  
  iTimeOut = argc == 2 ? 1 : atoi(argv[1]);  

  /* creat the raw socket for icmp */  

  if ((sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0)
  {  
    perror("socket";
    exit(2);  
  }  

  /* set destination host information */  

  bzero(&it, sizeof(it));  
  it.sin_family = AF_INET;  

  /* check host format */  

  if ( ( lHostIp = inet_addr(host) ) != INADDR_NONE )
  {  
  /* is available ip adress */  
  it.sin_addr.s_addr = lHostIp;  
  strcpy( dst_host, host );  
  }
  else if ( h = gethostbyname(host) )
  {  
    /* is available host name */  
    /* from hosts file of local host */  
    /* or from DNS */  
    bcopy(h->;h_addr, &it.sin_addr, h->;h_length);  
    sprintf( dst_host, "%s (%s)", host,  
    inet_ntoa(it.sin_addr) );  
  }
  else
  {  
    /* bad ip adress or host name */  
    /* exit */  
    fprintf( stderr, "bad IP or host\n" );  
    exit(3);  
  }

  namelen = sizeof(it);

  printf("\nPinging %s, send %d bytes\n", dst_host,  
    IP_HEADSIZE + ICMP_HEADSIZE + sizeof(long));

  seq = 0; /* first icmp_seq = 0 */  
  sigset(SIGINT, stat); /* when press del or ctrl+c, call stat */  
  /* to statistic the result , and then exit */  
  sigset(SIGALRM, ping); /* hook ping function to timer */  
  alarm(iTimeOut); /* start timer, call ping every timeout */  
  /* seconds */  
  ping();
  for ( ;; )
  { /* waiting for every echo back */  
    /* icmp packet and check it */  
    register size;  
    register u_char ttl;  
    register delta;  
    register iIpHeadLen;  

    /* block to received echo back datagram */  

    size = recvfrom(sock, buf, sizeof(buf), 0,  
    (struct sockaddr *)&it, &namelen);
//    size = recv(sock, buf, sizeof(buf), 0);

    printf("size:%d\n", size);
    printf("errno:%d\n", errno);
    printf("eintr:%d\n", EINTR);
   
//    if (size == -1 && errno == EINTR)
    if (size == -1)
    {
      /* receive error or system call */  
      /* interrupted */
      printf("error\n";
      continue;  
    }  

    /* calculate the round trip time, */  
    /* time when receive minus time when send */  

    delta = (int)((time_now() - lSendTime)/1000);  

    /* get echo back packet and check its ip header */  

    pIpHead = (IPHEAD *)buf;  

    /* get the ip packet lenth */  
    /* if too small, not the icmp echoreply packet */  
    /* give it up */  

    iIpHeadLen = (int)((pIpHead->;ip_verlen & 0x0f) << 2);  
    if (size < iIpHeadLen + ICMP_HEADSIZE)
    {  
      continue;  
    }  
    ttl = pIpHead->;ip_ttl; /* time to live param */  

    /* get the icmp header information */  
    pIcmpHead = (ICMPHEAD *)(buf + iIpHeadLen);  

    /* not icmp echo reply packet, give it up */  
    if (pIcmpHead->;icmp_type != ICMP_ECHOREPLY)
    {  
      continue;  
    }  

    /* not proper icmp sequent number, give it up */  
    if (pIcmpHead->;icmp_id != seq || pIcmpHead->;icmp_seq != seq)
    {  
      continue;  
    }  

    /* print out result for each icmp */  
    /* echo reply information */  
    sprintf( buf, "icmp_seq=%u bytes=%d ttl=%d", pIcmpHead->;icmp_seq, size, ttl );  
    fprintf(stderr, "reply from %s: %s time=%d ms\n", host, buf, delta);  

    /* calculate some statistic information */  
    /* max, min, average round trip time */  
    /* received icmp echo reply packet numbers */  
    max = MAX(delta, max);  
    min = min ? MIN(delta, min) : delta;  
    total += delta;  
    ++ recvd;  

    /* for next icmp sequence */  

    ++ seq;  
  }  
}  

ping()  
{  
  char buf[200];  
  int iPacketSize;

  
  /* make the icmp header information */  

  ICMPHEAD *pIcmpHead;
  pIcmpHead =(ICMPHEAD *)buf;
  pIcmpHead->;icmp_type = ICMP_ECHO;  
  pIcmpHead->;icmp_code = 0;  
  pIcmpHead->;icmp_id = seq;  
  pIcmpHead->;icmp_seq = seq;  
  pIcmpHead->;icmp_chksum = 0;  

  /* store time information as icmp packet content, 4 bytes */  
  /* u may store other information instead */  

  *((long *)pIcmpHead->;icmp_data) = time_now();  

  iPacketSize = ICMP_HEADSIZE + 4; /* icmp packet length */  

  /* icmp header check sum */  

  pIcmpHead->;icmp_chksum = ChkSum((u_short *)pIcmpHead,  
  iPacketSize );  

  /* remember the time when send for calculate round trip time */  
  lSendTime = time_now();  

  printf("pIcmpHead:%s:::\n", pIcmpHead);
  /* send the icmp packet to des host */
  int s;
//  if ( (s = sendto(sock, pIcmpHead, iPacketSize, 0, (struct sockaddr *)&it, sizeof(it) )) < 0)  //change把buf该成了pIcmpHead
  if ( (s = sendto(sock, pIcmpHead, iPacketSize, 0, (struct sockaddr *)&it, sizeof(it) )) < 0)  //change
  {  
    perror("send failed";  
    exit(6);
  }
  printf("s:%d\n", s);
  printf("here\n";
  
  /* packet number been sent */  
  ++sent;  
  printf("sent:%d\n", sent);

  /* reset the timer hooker to me again */  
  alarm(iTimeOut);

}  

void stat() /* print the statistic information for this time's ping */  
{  
  if (sent)
  {  
    printf("\n----- %s ping statistics summerized -----\n", host );  
    printf("%d packets sent, %d packets received, %.2f%% lost\n",  
      sent, recvd, (float)(sent-recvd)/(float)sent*100 );  
  }  
  if (recvd)
  {  
    printf("round_trip min/avg/max: %d/%d/%d ms\n\n",  min, total/recvd, max );  
  }  
  exit(0);  
}

reddatura

难道没有人能帮我么??

无双

发的时候成功没有

另外看看它的说明
会不会是你自己改错了

源码排版一下看的人会更多

reddatura

发的时候一经编译成功了,
我不会源码排版阿

帮帮忙!!

reddatura

1. 
   
2. 
   
3. /* PING.C  
   
4. /*  
   
5. /* ping source code distribute by cpu || digger.  
   
6. /* for unix family only. compil and link success in sco unix.  
   
7. /* i think linux no problem too. u can try it.
   
8. /* before read this code, you shoud know about the principle of  
   
9. /* tcp/ip, especially icmp protocol, u also should also know some  
   
10. /* about BSD socket API, and unix system signal programmin/g.
    
11. /*  
    
12. /* cc -o ping ping.c -lsocket, then u will get executable file,  
    
13. /* but must act as root when cc it, and then set euid attribute  
    
14. /* for this ping, then u can execute it as common user.  
    
15. /* because only root can have authority to creat raw socket.  
    
16. /*  
    
17. /* i love socket, if so do u,  
    
18. /* call me, cpu == digger  
    
19. 
    
20. */
    
21. 
    
22. #include <sys/types.h>;
    
23. #include <sys/socket.h>;
    
24. #include <netinet/in.h>;
    
25. #include <arpa/inet.h>;
    
26. #include <fcntl.h>;
    
27. #include <unistd.h>;
    
28. #include <stdarg.h>;
    
29. #include <stdio.h>;
    
30. #include <netdb.h>;
    
31. #include <sys/ioctl.h>;
    
32. #include <net/if.h>;
    
33. #include <stdlib.h>;
    
34. #include <stdio.h>;
    
35. #include <string.h>;
    
36. #include <signal.h>;
    
37. #include <errno.h>;
    
38. 
    
39. #define MAX(x,y) (x>;y)?x:y
    
40. #define MIN(x,y) (x<y)?x:y
    
41. #define ICMP_ECHO 8 /* icmp echo requir */
    
42. #define ICMP_ECHOREPLY 0 /* icmp echo reply */  
    
43. #define ICMP_HEADSIZE 8 /* icmp packet header size */  
    
44. #define IP_HEADSIZE 20 /* ip packet header size */  
    
45. 
    
46. typedef struct tagIpHead /* icmp packet header */  
    
47. {  
    
48.   u_char ip_verlen; /* ip version and ip header lenth*/  
    
49.   u_char ip_tos; /* ip type of service */  
    
50.   u_short ip_len; /* ip packet lenghth */  
    
51.   u_short ip_id; /* ip packet identification */  
    
52.   u_short ip_fragoff; /* ip packet fragment and offset */  
    
53.   u_char ip_ttl; /* ip packet time to live */  
    
54.   u_char ip_proto; /* ip packet protocol type */  
    
55.   u_short ip_chksum; /* ip packet header checksum */  
    
56.   u_long ip_src_addr; /* ip source ip adress */  
    
57.   u_long ip_dst_addr; /* ip destination ip adress */  
    
58. } IPHEAD;  
    
59. 
    
60. typedef struct tagIcmpHead /* icmp header */  
    
61. {  
    
62.   u_char icmp_type; /* icmp service type */  
    
63.   /* 8 echo require, 0 echo reply */  
    
64.   u_char icmp_code; /* icmp header code */  
    
65.   u_short icmp_chksum; /* icmp header chksum */  
    
66.   u_short icmp_id; /* icmp packet identification */  
    
67.   u_short icmp_seq; /* icmp packet sequent */  
    
68.   u_char icmp_data[1]; /* icmp data, use as pointer */  
    
69. } ICMPHEAD;  
    
70. 
    
71. /* for check sum of icmp header */
    
72. u_short ChkSum( u_short * pIcmpData, int iDataLen )  
    
73. {  
    
74.   u_short iSum;  
    
75.   u_short iOddByte;  
    
76. 
    
77.   iSum = 0;  
    
78. 
    
79.   while ( iDataLen >; 1 )
    
80.   { /* xor the next unsigned int data */  
    
81.     iSum ^= *pIcmpData++;  
    
82.     iDataLen -= 2;  
    
83.   }  
    
84. 
    
85.   if ( iDataLen == 1 )
    
86.   { /* the rest odd byte */  
    
87.     iOddByte = 0;  
    
88.     *((u_char *)&iOddByte) = *(u_char *)pIcmpData;  
    
89.     iSum ^= iOddByte;  
    
90.   }  
    
91. 
    
92.   iSum ^= 0xffff; /* xor 0xffff == not it */  
    
93.   return(iSum);  
    
94. }  
    
95. 
    
96. /* since 1970.1.1 00:00:00, */
    
97. /* in 1/1000000 second */
    
98. long time_now() /* return time passed by */  
    
99. {  
    
100.   struct timeval now;  
     
101.   long lPassed;  
     
102.   gettimeofday(&now, 0);  
     
103.   lPassed = now.tv_sec * 1000000 + now.tv_usec;  
     
104.   /* now.tv_sec in second */  
     
105.   /* now.tv_usec in 1/1000000 second */  
     
106.   return lPassed;  
     
107. }  
     
108. 
     
109. char* host; /* destination host */  
     
110. char* prog; /* program name */  
     
111. extern errno; /* system global parameter */  
     
112. long lSendTime; /* each time when send, change it */  
     
113. u_short seq; /* the icmp packet seqence */  
     
114. int iTimeOut; /* time out parameter */  
     
115. int sock, sent, recvd, max, min, total;  
     
116. /* sent : icmp packet already sent */  
     
117. /* recvd: proper icmp packet received */  
     
118. /* max, min: max min round trip time */  
     
119. /* total: total round trip time */  
     
120. /* store to calculate average */  
     
121. u_long lHostIp; /* host ip adress */  
     
122. struct sockaddr_in it; /* destination host information */  
     
123. 
     
124. int ping();  
     
125. void stat();  
     
126. 
     
127. main(int argc, char** argv)  
     
128. {  
     
129.   struct hostent* h;  
     
130.   char buf[200];  
     
131.   char dst_host[32];  
     
132.   int i, namelen;  
     
133.   IPHEAD* pIpHead;  
     
134.   ICMPHEAD* pIcmpHead;  
     
135. 
     
136.   if (argc < 2)
     
137.   {
     
138.     /* ping the destination host */  
     
139. 
     
140. 
     
141. 
     
142. 
     
143.     /* every timeout second */  
     
144.     /* default timeout is 1 second */  
     
145. 
     
146.     printf("usage: %s [-timeout] host|IP\n", argv[0]);  
     
147.     exit(0);  
     
148.   }  
     
149.   prog = argv[0];  
     
150.   host = argc == 2 ? argv[1] : argv[2];  
     
151.   iTimeOut = argc == 2 ? 1 : atoi(argv[1]);  
     
152. 
     
153.   /* creat the raw socket for icmp */  
     
154. 
     
155.   if ((sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0)
     
156.   {  
     
157.     perror("socket");
     
158.     exit(2);  
     
159.   }  
     
160. 
     
161.   /* set destination host information */  
     
162. 
     
163.   bzero(&it, sizeof(it));  
     
164.   it.sin_family = AF_INET;  
     
165. 
     
166.   /* check host format */  
     
167. 
     
168.   if ( ( lHostIp = inet_addr(host) ) != INADDR_NONE )
     
169.   {  
     
170.   /* is available ip adress */  
     
171.   it.sin_addr.s_addr = lHostIp;  
     
172.   strcpy( dst_host, host );  
     
173.   }
     
174.   else if ( h = gethostbyname(host) )
     
175.   {  
     
176.     /* is available host name */  
     
177.     /* from hosts file of local host */  
     
178.     /* or from DNS */  
     
179.     bcopy(h->;h_addr, &it.sin_addr, h->;h_length);  
     
180.     sprintf( dst_host, "%s (%s)", host,  
     
181.     inet_ntoa(it.sin_addr) );  
     
182.   }
     
183.   else
     
184.   {  
     
185.     /* bad ip adress or host name */  
     
186.     /* exit */  
     
187.     fprintf( stderr, "bad IP or host\n" );  
     
188.     exit(3);  
     
189.   }
     
190. 
     
191.   namelen = sizeof(it);
     
192. 
     
193.   printf("\nPinging %s, send %d bytes\n", dst_host,  
     
194.     IP_HEADSIZE + ICMP_HEADSIZE + sizeof(long));
     
195. 
     
196.   seq = 0; /* first icmp_seq = 0 */  
     
197.   sigset(SIGINT, stat); /* when press del or ctrl+c, call stat */  
     
198.   /* to statistic the result , and then exit */  
     
199.   sigset(SIGALRM, ping); /* hook ping function to timer */  
     
200.   alarm(iTimeOut); /* start timer, call ping every timeout */  
     
201.   /* seconds */  
     
202.   ping();
     
203.   for ( ;; )
     
204.   { /* waiting for every echo back */  
     
205.     /* icmp packet and check it */  
     
206.     register size;  
     
207.     register u_char ttl;  
     
208.     register delta;  
     
209.     register iIpHeadLen;  
     
210. 
     
211.     /* block to received echo back datagram */  
     
212. 
     
213.     size = recvfrom(sock, buf, sizeof(buf), 0,  
     
214.     (struct sockaddr *)&it, &namelen);
     
215. //    size = recv(sock, buf, sizeof(buf), 0);
     
216. 
     
217.     printf("size:%d\n", size);
     
218.     printf("errno:%d\n", errno);
     
219.     printf("eintr:%d\n", EINTR);
     
220.    
     
221. //    if (size == -1 && errno == EINTR)
     
222.     if (size == -1)
     
223.     {
     
224.       /* receive error or system call */  
     
225.       /* interrupted */
     
226.       printf("error\n");
     
227.       continue;  
     
228.     }  
     
229. 
     
230.     printf("recvbuf:%s\n", buf);
     
231.     /* calculate the round trip time, */  
     
232.     /* time when receive minus time when send */  
     
233. 
     
234.     delta = (int)((time_now() - lSendTime)/1000);  
     
235. 
     
236.     /* get echo back packet and check its ip header */  
     
237. 
     
238.     pIpHead = (IPHEAD *)buf;  
     
239. 
     
240.     /* get the ip packet lenth */  
     
241.     /* if too small, not the icmp echoreply packet */  
     
242.     /* give it up */  
     
243. 
     
244.     iIpHeadLen = (int)((pIpHead->;ip_verlen & 0x0f) << 2);  
     
245.     if (size < iIpHeadLen + ICMP_HEADSIZE)
     
246.     {  
     
247.       continue;  
     
248.     }  
     
249.     ttl = pIpHead->;ip_ttl; /* time to live param */  
     
250. 
     
251.     /* get the icmp header information */  
     
252.     pIcmpHead = (ICMPHEAD *)(buf + iIpHeadLen);  
     
253. 
     
254.     /* not icmp echo reply packet, give it up */  
     
255.     if (pIcmpHead->;icmp_type != ICMP_ECHOREPLY)
     
256.     {  
     
257.       continue;  
     
258.     }  
     
259. 
     
260.     /* not proper icmp sequent number, give it up */  
     
261.     if (pIcmpHead->;icmp_id != seq || pIcmpHead->;icmp_seq != seq)
     
262.     {  
     
263.       continue;  
     
264.     }  
     
265. 
     
266.     /* print out result for each icmp */  
     
267.     /* echo reply information */  
     
268.     sprintf( buf, "icmp_seq=%u bytes=%d ttl=%d", pIcmpHead->;icmp_seq, size, ttl );  
     
269.     fprintf(stderr, "reply from %s: %s time=%d ms\n", host, buf, delta);  
     
270. 
     
271.     /* calculate some statistic information */  
     
272.     /* max, min, average round trip time */  
     
273.     /* received icmp echo reply packet numbers */  
     
274.     max = MAX(delta, max);  
     
275.     min = min ? MIN(delta, min) : delta;  
     
276.     total += delta;  
     
277.     ++ recvd;  
     
278. 
     
279.     /* for next icmp sequence */  
     
280. 
     
281.     ++ seq;  
     
282.   }  
     
283. }  
     
284. 
     
285. ping()  
     
286. {  
     
287.   char buf[200];  
     
288.   int iPacketSize;
     
289. 
     
290.   
     
291.   /* make the icmp header information */  
     
292. 
     
293.   ICMPHEAD *pIcmpHead;
     
294.   pIcmpHead =(ICMPHEAD *)buf;
     
295.   pIcmpHead->;icmp_type = ICMP_ECHO;  
     
296.   pIcmpHead->;icmp_code = 0;  
     
297.   pIcmpHead->;icmp_id = seq;  
     
298.   pIcmpHead->;icmp_seq = seq;  
     
299.   pIcmpHead->;icmp_chksum = 0;  
     
300. 
     
301.   /* store time information as icmp packet content, 4 bytes */  
     
302.   /* u may store other information instead */  
     
303. 
     
304.   *((long *)pIcmpHead->;icmp_data) = time_now();  
     
305. 
     
306.   iPacketSize = ICMP_HEADSIZE + 4; /* icmp packet length */  
     
307. 
     
308.   /* icmp header check sum */  
     
309. 
     
310.   pIcmpHead->;icmp_chksum = ChkSum((u_short *)pIcmpHead,  
     
311.   iPacketSize );  
     
312. 
     
313.   /* remember the time when send for calculate round trip time */  
     
314.   lSendTime = time_now();  
     
315. 
     
316.   printf("pIcmpHead:%s:::\n", pIcmpHead);
     
317.   /* send the icmp packet to des host */
     
318.   int s;
     
319. //  if ( (s = sendto(sock, pIcmpHead, iPacketSize, 0, (struct sockaddr *)&it, sizeof(it) )) < 0)  //change
     
320.   if ( (s = sendto(sock, buf, iPacketSize, 0, (struct sockaddr *)&it, sizeof(it) )) < 0)  //change
     
321.   {  
     
322.     perror("send failed");  
     
323.     exit(6);
     
324.   }
     
325.   printf("s:%d\n", s);
     
326.   printf("here\n");
     
327.   
     
328.   /* packet number been sent */  
     
329.   ++sent;  
     
330. 
     
331.   printf("sent:%d\n", sent);
     
332. 
     
333.   /* reset the timer hooker to me again */  
     
334.   alarm(iTimeOut);
     
335. 
     
336. }  
     
337. 
     
338. void stat() /* print the statistic information for this time's ping */  
     
339. {  
     
340.   if (sent)
     
341.   {  
     
342.     printf("\n----- %s ping statistics summerized -----\n", host );  
     
343.     printf("%d packets sent, %d packets received, %.2f%% lost\n",  
     
344.       sent, recvd, (float)(sent-recvd)/(float)sent*100 );  
     
345.   }  
     
346.   if (recvd)
     
347.   {  
     
348.     printf("round_trip min/avg/max: %d/%d/%d ms\n\n",  min, total/recvd, max );  
     
349.   }  
     
350.   exit(0);  
     
351. }  
     
352. 
     
353. 
     
354. 
     
355. 
     
356. 
     
357. 
     
358. 
     

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无双

1. 
   
2.         if ( (s = sendto(sock, buf, iPacketSize, 0, (struct sockaddr *)&it, sizeof(it) )) < 0)  //change
   
3.         {  
   
4.                 perror("send failed");  
   
5.                 exit(6);
   
6.         }
   

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这里s返回值等于几

liupch

如果我没记错的话，那个源程序在作数据包首部校验和的算法有错误。
我用我的一个计算校验和的函数替代原来的chkSum就可以了。

1. 
   
2. u_short myChkSum(u_short *addr, int len)
   
3. {
   
4.         register int nleft = len;
   
5.         register u_short *w = addr;
   
6.         register u_short answer;
   
7.         register int sum = 0;
   
8. 
   
9.         /*
   
10.          *  Our algorithm is simple, using a 32 bit accumulator (sum),
    
11.          *  we add sequential 16 bit words to it, and at the end, fold
    
12.          *  back all the carry bits from the top 16 bits into the lower
    
13.          *  16 bits.
    
14.          */
    
15.         while( nleft >; 1 )  {
    
16.                 sum += *w++;
    
17.                 nleft -= 2;
    
18.         }
    
19. 
    
20.         /* mop up an odd byte, if necessary */
    
21.        
    
22.         if( nleft == 1 ) {
    
23.                 u_short        u = 0;
    
24. 
    
25.                 *(u_char *)(&u) = *(u_char *)w ;
    
26.                 sum += u;
    
27.         }
    
28. 
    
29.         /*
    
30.          * add back carry outs from top 16 bits to low 16 bits
    
31.          */
    
32.         sum = (sum >;>; 16) + (sum & 0xffff);        /* add hi 16 to low 16 */
    
33.         sum += (sum >;>; 16);                        /* add carry */
    
34.         answer = ~sum;                                /* truncate to 16 bits */
    
35.         return (answer);
    
36. }
    

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无双

liupch  兄能不能介绍它的校验和产生原理

liupch

[quote]原帖由 "无双"]liupch  兄能不能介绍它的校验和产生原理[/quote 发表：
     

就是标准的RCR冗余校验

reddatura

真是厉害!!!!!!!!!!!!!!!!!11


多谢!!!!!!!!!!!!!!