networking/ping.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * $Id: ping.c,v 1.56 2004/03/15 08:28:48 andersen Exp $
   4  * Mini ping implementation for busybox
   5  *
   6  * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
   7  *
   8  * Adapted from the ping in netkit-base 0.10:
   9  * Copyright (c) 1989 The Regents of the University of California.
  10  * Derived from software contributed to Berkeley by Mike Muuss.
  11  *
  12  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  13  */
  14
  15 #include <sys/param.h>
  16 #include <sys/socket.h>
  17 #include <sys/file.h>
  18 #include <sys/times.h>
  19 #include <signal.h>
  20
  21 #include <netinet/in.h>
  22 #include <netinet/ip.h>
  23 #include <netinet/ip_icmp.h>
  24 #include <arpa/inet.h>
  25 #include <netdb.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <errno.h>
  29 #include <unistd.h>
  30 #include <string.h>
  31 #include <stdlib.h>
  32 #include "busybox.h"
  33
  34 enum {
  35         DEFDATALEN = 56,
  36         MAXIPLEN = 60,
  37         MAXICMPLEN = 76,
  38         MAXPACKET = 65468,
  39         MAX_DUP_CHK = (8 * 128),
  40         MAXWAIT = 10,
  41         PINGINTERVAL = 1                /* second */
  42 };
  43
  44 #define O_QUIET         (1 << 0)
  45
  46 #define A(bit)          rcvd_tbl[(bit)>>3]      /* identify byte in array */
  47 #define B(bit)          (1 << ((bit) & 0x07))   /* identify bit in byte */
  48 #define SET(bit)        (A(bit) |= B(bit))
  49 #define CLR(bit)        (A(bit) &= (~B(bit)))
  50 #define TST(bit)        (A(bit) & B(bit))
  51
  52 static void ping(const char *host);
  53
  54 /* common routines */
  55 static int in_cksum(unsigned short *buf, int sz)
  56 {
  57         int nleft = sz;
  58         int sum = 0;
  59         unsigned short *w = buf;
  60         unsigned short ans = 0;
  61
  62         while (nleft > 1) {
  63                 sum += *w++;
  64                 nleft -= 2;
  65         }
  66
  67         if (nleft == 1) {
  68                 *(unsigned char *) (&ans) = *(unsigned char *) w;
  69                 sum += ans;
  70         }
  71
  72         sum = (sum >> 16) + (sum & 0xFFFF);
  73         sum += (sum >> 16);
  74         ans = ~sum;
  75         return (ans);
  76 }
  77
  78 /* simple version */
  79 #ifndef CONFIG_FEATURE_FANCY_PING
  80 static char *hostname;
  81
  82 static void noresp(int ign)
  83 {
  84         printf("No response from %s\n", hostname);
  85         exit(EXIT_FAILURE);
  86 }
  87
  88 static void ping(const char *host)
  89 {
  90         struct hostent *h;
  91         struct sockaddr_in pingaddr;
  92         struct icmp *pkt;
  93         int pingsock, c;
  94         char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
  95
  96         pingsock = create_icmp_socket();
  97
  98         memset(&pingaddr, 0, sizeof(struct sockaddr_in));
  99
 100         pingaddr.sin_family = AF_INET;
 101         h = xgethostbyname(host);
 102         memcpy(&pingaddr.sin_addr, h->h_addr, sizeof(pingaddr.sin_addr));
 103         hostname = h->h_name;
 104
 105         pkt = (struct icmp *) packet;
 106         memset(pkt, 0, sizeof(packet));
 107         pkt->icmp_type = ICMP_ECHO;
 108         pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));
 109
 110         c = sendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN, 0,
 111                            (struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));
 112
 113         if (c < 0) {
 114                 if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
 115                 bb_perror_msg_and_die("sendto");
 116         }
 117
 118         signal(SIGALRM, noresp);
 119         alarm(5);                                       /* give the host 5000ms to respond */
 120         /* listen for replies */
 121         while (1) {
 122                 struct sockaddr_in from;
 123                 socklen_t fromlen = sizeof(from);
 124
 125                 if ((c = recvfrom(pingsock, packet, sizeof(packet), 0,
 126                                                   (struct sockaddr *) &from, &fromlen)) < 0) {
 127                         if (errno == EINTR)
 128                                 continue;
 129                         bb_perror_msg("recvfrom");
 130                         continue;
 131                 }
 132                 if (c >= 76) {                  /* ip + icmp */
 133                         struct iphdr *iphdr = (struct iphdr *) packet;
 134
 135                         pkt = (struct icmp *) (packet + (iphdr->ihl << 2));     /* skip ip hdr */
 136                         if (pkt->icmp_type == ICMP_ECHOREPLY)
 137                                 break;
 138                 }
 139         }
 140         if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
 141         printf("%s is alive!\n", hostname);
 142         return;
 143 }
 144
 145 int ping_main(int argc, char **argv)
 146 {
 147         argc--;
 148         argv++;
 149         if (argc < 1)
 150                 bb_show_usage();
 151         ping(*argv);
 152         return EXIT_SUCCESS;
 153 }
 154
 155 #else /* ! CONFIG_FEATURE_FANCY_PING */
 156 /* full(er) version */
 157 static struct sockaddr_in pingaddr;
 158 static struct sockaddr_in sourceaddr;
 159 static int pingsock = -1;
 160 static int datalen; /* intentionally uninitialized to work around gcc bug */
 161
 162 static long ntransmitted, nreceived, nrepeats, pingcount;
 163 static int myid, options;
 164 static unsigned long tmin = ULONG_MAX, tmax, tsum;
 165 static char rcvd_tbl[MAX_DUP_CHK / 8];
 166
 167 static struct hostent *hostent;
 168
 169 static void sendping(int);
 170 static void pingstats(int);
 171 static void unpack(char *, int, struct sockaddr_in *);
 172
 173 /**************************************************************************/
 174
 175 static void pingstats(int junk)
 176 {
 177         int status;
 178
 179         signal(SIGINT, SIG_IGN);
 180
 181         printf("\n--- %s ping statistics ---\n", hostent->h_name);
 182         printf("%ld packets transmitted, ", ntransmitted);
 183         printf("%ld packets received, ", nreceived);
 184         if (nrepeats)
 185                 printf("%ld duplicates, ", nrepeats);
 186         if (ntransmitted)
 187                 printf("%ld%% packet loss\n",
 188                            (ntransmitted - nreceived) * 100 / ntransmitted);
 189         if (nreceived)
 190                 printf("round-trip min/avg/max = %lu.%lu/%lu.%lu/%lu.%lu ms\n",
 191                            tmin / 10, tmin % 10,
 192                            (tsum / (nreceived + nrepeats)) / 10,
 193                            (tsum / (nreceived + nrepeats)) % 10, tmax / 10, tmax % 10);
 194         if (nreceived != 0)
 195                 status = EXIT_SUCCESS;
 196         else
 197                 status = EXIT_FAILURE;
 198         exit(status);
 199 }
 200
 201 static void sendping(int junk)
 202 {
 203         struct icmp *pkt;
 204         int i;
 205         char packet[datalen + ICMP_MINLEN];
 206
 207         pkt = (struct icmp *) packet;
 208
 209         pkt->icmp_type = ICMP_ECHO;
 210         pkt->icmp_code = 0;
 211         pkt->icmp_cksum = 0;
 212         pkt->icmp_seq = htons(ntransmitted++);
 213         pkt->icmp_id = myid;
 214         CLR(ntohs(pkt->icmp_seq) % MAX_DUP_CHK);
 215
 216         gettimeofday((struct timeval *) &pkt->icmp_dun, NULL);
 217         pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));
 218
 219         i = sendto(pingsock, packet, sizeof(packet), 0,
 220                            (struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));
 221
 222         if (i < 0)
 223                 bb_perror_msg_and_die("sendto");
 224         else if ((size_t)i != sizeof(packet))
 225                 bb_error_msg_and_die("ping wrote %d chars; %d expected", i,
 226                            (int)sizeof(packet));
 227
 228         signal(SIGALRM, sendping);
 229         if (pingcount == 0 || ntransmitted < pingcount) {       /* schedule next in 1s */
 230                 alarm(PINGINTERVAL);
 231         } else {                                        /* done, wait for the last ping to come back */
 232                 /* todo, don't necessarily need to wait so long... */
 233                 signal(SIGALRM, pingstats);
 234                 alarm(MAXWAIT);
 235         }
 236 }
 237
 238 static char *icmp_type_name(int id)
 239 {
 240         switch (id) {
 241         case ICMP_ECHOREPLY:            return "Echo Reply";
 242         case ICMP_DEST_UNREACH:         return "Destination Unreachable";
 243         case ICMP_SOURCE_QUENCH:        return "Source Quench";
 244         case ICMP_REDIRECT:                     return "Redirect (change route)";
 245         case ICMP_ECHO:                         return "Echo Request";
 246         case ICMP_TIME_EXCEEDED:        return "Time Exceeded";
 247         case ICMP_PARAMETERPROB:        return "Parameter Problem";
 248         case ICMP_TIMESTAMP:            return "Timestamp Request";
 249         case ICMP_TIMESTAMPREPLY:       return "Timestamp Reply";
 250         case ICMP_INFO_REQUEST:         return "Information Request";
 251         case ICMP_INFO_REPLY:           return "Information Reply";
 252         case ICMP_ADDRESS:                      return "Address Mask Request";
 253         case ICMP_ADDRESSREPLY:         return "Address Mask Reply";
 254         default:                                        return "unknown ICMP type";
 255         }
 256 }
 257
 258 static void unpack(char *buf, int sz, struct sockaddr_in *from)
 259 {
 260         struct icmp *icmppkt;
 261         struct iphdr *iphdr;
 262         struct timeval tv, *tp;
 263         int hlen, dupflag;
 264         unsigned long triptime;
 265
 266         gettimeofday(&tv, NULL);
 267
 268         /* discard if too short */
 269         if (sz < (datalen + ICMP_MINLEN))
 270                 return;
 271
 272         /* check IP header */
 273         iphdr = (struct iphdr *) buf;
 274         hlen = iphdr->ihl << 2;
 275         sz -= hlen;
 276         icmppkt = (struct icmp *) (buf + hlen);
 277         if (icmppkt->icmp_id != myid)
 278                 return;                         /* not our ping */
 279
 280         if (icmppkt->icmp_type == ICMP_ECHOREPLY) {
 281                 u_int16_t recv_seq = ntohs(icmppkt->icmp_seq);
 282                 ++nreceived;
 283                 tp = (struct timeval *) icmppkt->icmp_data;
 284
 285                 if ((tv.tv_usec -= tp->tv_usec) < 0) {
 286                         --tv.tv_sec;
 287                         tv.tv_usec += 1000000;
 288                 }
 289                 tv.tv_sec -= tp->tv_sec;
 290
 291                 triptime = tv.tv_sec * 10000 + (tv.tv_usec / 100);
 292                 tsum += triptime;
 293                 if (triptime < tmin)
 294                         tmin = triptime;
 295                 if (triptime > tmax)
 296                         tmax = triptime;
 297
 298                 if (TST(recv_seq % MAX_DUP_CHK)) {
 299                         ++nrepeats;
 300                         --nreceived;
 301                         dupflag = 1;
 302                 } else {
 303                         SET(recv_seq % MAX_DUP_CHK);
 304                         dupflag = 0;
 305                 }
 306
 307                 if (options & O_QUIET)
 308                         return;
 309
 310                 printf("%d bytes from %s: icmp_seq=%u", sz,
 311                            inet_ntoa(*(struct in_addr *) &from->sin_addr.s_addr),
 312                            recv_seq);
 313                 printf(" ttl=%d", iphdr->ttl);
 314                 printf(" time=%lu.%lu ms", triptime / 10, triptime % 10);
 315                 if (dupflag)
 316                         printf(" (DUP!)");
 317                 printf("\n");
 318         } else
 319                 if (icmppkt->icmp_type != ICMP_ECHO)
 320                         bb_error_msg("Warning: Got ICMP %d (%s)",
 321                                         icmppkt->icmp_type, icmp_type_name(icmppkt->icmp_type));
 322         fflush(stdout);
 323 }
 324
 325 static void ping(const char *host)
 326 {
 327         char packet[datalen + MAXIPLEN + MAXICMPLEN];
 328         int sockopt;
 329
 330         pingsock = create_icmp_socket();
 331
 332         if (sourceaddr.sin_addr.s_addr) {
 333                 if (bind(pingsock, (struct sockaddr*)&sourceaddr, sizeof(sourceaddr)) == -1)
 334                         bb_error_msg_and_die("could not bind to address");
 335         }
 336
 337         memset(&pingaddr, 0, sizeof(struct sockaddr_in));
 338
 339         pingaddr.sin_family = AF_INET;
 340         hostent = xgethostbyname(host);
 341         if (hostent->h_addrtype != AF_INET)
 342                 bb_error_msg_and_die("unknown address type; only AF_INET is currently supported");
 343
 344         memcpy(&pingaddr.sin_addr, hostent->h_addr, sizeof(pingaddr.sin_addr));
 345
 346         /* enable broadcast pings */
 347         sockopt = 1;
 348         setsockopt(pingsock, SOL_SOCKET, SO_BROADCAST, (char *) &sockopt,
 349                            sizeof(sockopt));
 350
 351         /* set recv buf for broadcast pings */
 352         sockopt = 48 * 1024;
 353         setsockopt(pingsock, SOL_SOCKET, SO_RCVBUF, (char *) &sockopt,
 354                            sizeof(sockopt));
 355
 356         printf("PING %s (%s)",
 357                         hostent->h_name,
 358                         inet_ntoa(*(struct in_addr *) &pingaddr.sin_addr.s_addr));
 359         if (sourceaddr.sin_addr.s_addr) {
 360                 printf(" from %s",
 361                         inet_ntoa(*(struct in_addr *) &sourceaddr.sin_addr.s_addr));
 362         }
 363         printf(": %d data bytes\n", datalen);
 364
 365         signal(SIGINT, pingstats);
 366
 367         /* start the ping's going ... */
 368         sendping(0);
 369
 370         /* listen for replies */
 371         while (1) {
 372                 struct sockaddr_in from;
 373                 socklen_t fromlen = (socklen_t) sizeof(from);
 374                 int c;
 375
 376                 if ((c = recvfrom(pingsock, packet, sizeof(packet), 0,
 377                                                   (struct sockaddr *) &from, &fromlen)) < 0) {
 378                         if (errno == EINTR)
 379                                 continue;
 380                         bb_perror_msg("recvfrom");
 381                         continue;
 382                 }
 383                 unpack(packet, c, &from);
 384                 if (pingcount > 0 && nreceived >= pingcount)
 385                         break;
 386         }
 387         pingstats(0);
 388 }
 389
 390 /* TODO: consolidate ether-wake.c, dnsd.c, ifupdown.c, nslookup.c
 391  * versions of below thing. BTW we have far too many "%u.%u.%u.%u" too...
 392 */
 393 static int parse_nipquad(const char *str, struct sockaddr_in* addr)
 394 {
 395         char dummy;
 396         unsigned i1, i2, i3, i4;
 397         if (sscanf(str, "%u.%u.%u.%u%c",
 398                            &i1, &i2, &i3, &i4, &dummy) == 4
 399         && ( (i1|i2|i3|i4) <= 0xff )
 400         ) {
 401                 uint8_t* ptr = (uint8_t*)&addr->sin_addr;
 402                 ptr[0] = i1;
 403                 ptr[1] = i2;
 404                 ptr[2] = i3;
 405                 ptr[3] = i4;
 406                 return 0;
 407         }
 408         return 1; /* error */
 409 }
 410
 411 int ping_main(int argc, char **argv)
 412 {
 413         char *thisarg;
 414
 415         datalen = DEFDATALEN; /* initialized here rather than in global scope to work around gcc bug */
 416
 417         argc--;
 418         argv++;
 419         /* Parse any options */
 420         while (argc >= 1 && **argv == '-') {
 421                 thisarg = *argv;
 422                 thisarg++;
 423                 switch (*thisarg) {
 424                 case 'q':
 425                         options |= O_QUIET;
 426                         break;
 427                 case 'c':
 428                         if (--argc <= 0)
 429                                 bb_show_usage();
 430                         argv++;
 431                         pingcount = atoi(*argv);
 432                         break;
 433                 case 's':
 434                         if (--argc <= 0)
 435                                 bb_show_usage();
 436                         argv++;
 437                         datalen = atoi(*argv);
 438                         break;
 439                 case 'I':
 440                         if (--argc <= 0)
 441                                 bb_show_usage();
 442                         argv++;
 443 /* ping6 accepts iface too:
 444                         if_index = if_nametoindex(*argv);
 445                         if (!if_index) ...
 446    make it true for ping too. TODO.
 447 */
 448                         if (parse_nipquad(*argv, &sourceaddr))
 449                                 bb_show_usage();
 450                         break;
 451                 default:
 452                         bb_show_usage();
 453                 }
 454                 argc--;
 455                 argv++;
 456         }
 457         if (argc < 1)
 458                 bb_show_usage();
 459
 460         myid = (int16_t) getpid();
 461         ping(*argv);
 462         return EXIT_SUCCESS;
 463 }
 464 #endif /* ! CONFIG_FEATURE_FANCY_PING */