ping.c 5.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308
  1. #include <u.h>
  2. #include <libc.h>
  3. #include <ip.h>
  4. typedef struct Icmp Icmp;
  5. struct Icmp
  6. {
  7. uchar vihl; /* Version and header length */
  8. uchar tos; /* Type of service */
  9. uchar length[2]; /* packet length */
  10. uchar id[2]; /* Identification */
  11. uchar frag[2]; /* Fragment information */
  12. uchar ttl; /* Time to live */
  13. uchar proto; /* Protocol */
  14. uchar ipcksum[2]; /* Header checksum */
  15. uchar src[4]; /* Ip source */
  16. uchar dst[4]; /* Ip destination */
  17. uchar type;
  18. uchar code;
  19. uchar cksum[2];
  20. uchar icmpid[2];
  21. uchar seq[2];
  22. uchar data[1];
  23. };
  24. enum
  25. { /* Packet Types */
  26. EchoReply = 0,
  27. Unreachable = 3,
  28. SrcQuench = 4,
  29. EchoRequest = 8,
  30. TimeExceed = 11,
  31. Timestamp = 13,
  32. TimestampReply = 14,
  33. InfoRequest = 15,
  34. InfoReply = 16,
  35. ICMP_IPSIZE = 20,
  36. ICMP_HDRSIZE = 8,
  37. MAXMSG = 32,
  38. SLEEPMS = 1000,
  39. };
  40. typedef struct Req Req;
  41. struct Req
  42. {
  43. int seq; // sequence number
  44. vlong time; // time sent
  45. vlong rtt;
  46. int ttl;
  47. int replied;
  48. Req *next;
  49. };
  50. Req *first; // request list
  51. Req *last; // ...
  52. Lock listlock;
  53. char *argv0;
  54. int debug;
  55. int quiet;
  56. int lostmsgs;
  57. int rcvdmsgs;
  58. int done;
  59. vlong sum;
  60. ushort firstseq;
  61. int addresses;
  62. void usage(void);
  63. void lost(Req*);
  64. void reply(Req*, Icmp*);
  65. #define SECOND 1000000000LL
  66. #define MINUTE (60LL*SECOND)
  67. void
  68. usage(void)
  69. {
  70. fprint(2, "usage: %s destination\n", argv0);
  71. exits("usage");
  72. }
  73. static void
  74. catch(void *a, char *msg)
  75. {
  76. USED(a);
  77. if(strstr(msg, "alarm"))
  78. noted(NCONT);
  79. else
  80. noted(NDFLT);
  81. }
  82. void
  83. clean(ushort seq, vlong now, Icmp *ip)
  84. {
  85. Req **l, *r;
  86. lock(&listlock);
  87. for(l = &first; *l; ){
  88. r = *l;
  89. if(r->seq == seq){
  90. r->rtt = now-r->time;
  91. r->ttl = ip->ttl;
  92. reply(r, ip);
  93. }
  94. if(now-r->time > MINUTE){
  95. *l = r->next;
  96. r->rtt = now-r->time;
  97. r->ttl = ip->ttl;
  98. if(r->replied == 0)
  99. lost(r);
  100. free(r);
  101. } else {
  102. last = r;
  103. l = &(r->next);
  104. }
  105. }
  106. unlock(&listlock);
  107. }
  108. void
  109. sender(int fd, int msglen, int interval, int n)
  110. {
  111. char buf[64*1024+512];
  112. Icmp *ip;
  113. int i;
  114. Req *r;
  115. ushort seq;
  116. ip = (Icmp*)buf;
  117. srand(time(0));
  118. firstseq = seq = rand();
  119. for(i = 32; i < msglen; i++)
  120. buf[i] = i;
  121. ip->type = EchoRequest;
  122. ip->code = 0;
  123. for(i = 0; i < n; i++){
  124. if(i != 0)
  125. sleep(interval);
  126. r = malloc(sizeof *r);
  127. if(r != nil){
  128. ip->seq[0] = seq;
  129. ip->seq[1] = seq>>8;
  130. r->seq = seq;
  131. r->next = nil;
  132. lock(&listlock);
  133. if(first == nil)
  134. first = r;
  135. else
  136. last->next = r;
  137. last = r;
  138. unlock(&listlock);
  139. r->replied = 0;
  140. r->time = nsec();
  141. if(write(fd, ip, msglen) < msglen){
  142. fprint(2, "%s: write failed: %r\n", argv0);
  143. return;
  144. }
  145. seq++;
  146. }
  147. }
  148. done = 1;
  149. }
  150. void
  151. rcvr(int fd, int msglen, int interval, int nmsg)
  152. {
  153. uchar buf[64*1024+512];
  154. Icmp *ip;
  155. ushort x;
  156. int i, n, munged;
  157. vlong now;
  158. Req *r;
  159. ip = (Icmp*)buf;
  160. sum = 0;
  161. while(!done || first != nil){
  162. alarm((nmsg-lostmsgs-rcvdmsgs)*interval+5000);
  163. n = read(fd, buf, sizeof(buf));
  164. alarm(0);
  165. now = nsec();
  166. if(n <= 0)
  167. break;
  168. if(n < msglen){
  169. print("bad len %d/%d\n", n, msglen);
  170. continue;
  171. }
  172. munged = 0;
  173. for(i = 32; i < msglen; i++)
  174. if(buf[i] != (i&0xff))
  175. munged++;
  176. if(munged)
  177. print("currupted reply\n");
  178. x = (ip->seq[1]<<8)|ip->seq[0];
  179. if(ip->type != EchoReply || ip->code != 0) {
  180. print("bad sequence/code/type %d/%d/%d\n",
  181. ip->type, ip->code, x);
  182. continue;
  183. }
  184. clean(x, now, ip);
  185. }
  186. lock(&listlock);
  187. for(r = first; r; r = r->next)
  188. if(r->replied == 0)
  189. lostmsgs++;
  190. unlock(&listlock);
  191. if(lostmsgs)
  192. print("%d out of %d messages lost\n", lostmsgs, lostmsgs+rcvdmsgs);
  193. }
  194. void
  195. main(int argc, char **argv)
  196. {
  197. int fd;
  198. int msglen, interval, nmsg;
  199. nsec(); /* make sure time file is already open */
  200. fmtinstall('V', eipfmt);
  201. msglen = interval = 0;
  202. nmsg = MAXMSG;
  203. ARGBEGIN {
  204. case 'd':
  205. debug++;
  206. break;
  207. case 's':
  208. msglen = atoi(ARGF());
  209. break;
  210. case 'i':
  211. interval = atoi(ARGF());
  212. break;
  213. case 'n':
  214. nmsg = atoi(ARGF());
  215. break;
  216. case 'a':
  217. addresses = 1;
  218. break;
  219. case 'q':
  220. quiet = 1;
  221. break;
  222. } ARGEND;
  223. if(msglen < 32)
  224. msglen = 64;
  225. if(msglen >= 65*1024)
  226. msglen = 65*1024-1;
  227. if(interval <= 0)
  228. interval = SLEEPMS;
  229. if(argc < 1)
  230. usage();
  231. notify(catch);
  232. fd = dial(netmkaddr(argv[0], "icmp", "1"), 0, 0, 0);
  233. if(fd < 0){
  234. fprint(2, "%s: couldn't dial: %r\n", argv0);
  235. exits("dialing");
  236. }
  237. print("sending %d %d byte messages %d ms apart\n", nmsg, msglen, interval);
  238. switch(rfork(RFPROC|RFMEM|RFFDG)){
  239. case -1:
  240. fprint(2, "%s: can't fork: %r\n", argv0);
  241. case 0:
  242. rcvr(fd, msglen, interval, nmsg);
  243. exits(0);
  244. default:
  245. sender(fd, msglen, interval, nmsg);
  246. wait();
  247. exits(lostmsgs ? "lost messages" : "");
  248. }
  249. }
  250. void
  251. lost(Req *)
  252. {
  253. lostmsgs++;
  254. }
  255. void
  256. reply(Req *r, Icmp *ip)
  257. {
  258. rcvdmsgs++;
  259. r->rtt /= 1000LL;
  260. sum += r->rtt;
  261. if(!quiet){
  262. if(addresses)
  263. print("%ud: %V->%V rtt %lld µs, avg rtt %lld µs, ttl = %d\n",
  264. r->seq-firstseq,
  265. ip->src, ip->dst,
  266. r->rtt, sum/rcvdmsgs, r->ttl);
  267. else
  268. print("%ud: rtt %lld µs, avg rtt %lld µs, ttl = %d\n",
  269. r->seq-firstseq,
  270. r->rtt, sum/rcvdmsgs, r->ttl);
  271. }
  272. r->replied = 1;
  273. }