src/pinger.cc

   1
   2 /*
   3  * $Id: pinger.cc,v 1.28 1997/10/31 05:15:08 wessels Exp $
   4  *
   5  * DEBUG: section 42    ICMP Pinger program
   6  * AUTHOR: Duane Wessels
   7  *
   8  * SQUID Internet Object Cache  http://squid.nlanr.net/Squid/
   9  * --------------------------------------------------------
  10  *
  11  *  Squid is the result of efforts by numerous individuals from the
  12  *  Internet community.  Development is led by Duane Wessels of the
  13  *  National Laboratory for Applied Network Research and funded by
  14  *  the National Science Foundation.
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License as published by
  18  *  the Free Software Foundation; either version 2 of the License, or
  19  *  (at your option) any later version.
  20  *
  21  *  This program is distributed in the hope that it will be useful,
  22  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *  GNU General Public License for more details.
  25  *
  26  *  You should have received a copy of the GNU General Public License
  27  *  along with this program; if not, write to the Free Software
  28  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  29  *
  30  */
  31
  32 #include "squid.h"
  33
  34 #if USE_ICMP
  35
  36 #include <netinet/in_systm.h>
  37 #include <netinet/in.h>
  38 #include <netinet/ip.h>
  39 #include <netinet/ip_icmp.h>
  40
  41 #ifndef _SQUID_LINUX_
  42 #define icmphdr icmp
  43 #define iphdr ip
  44 #endif
  45
  46 #ifdef _SQUID_LINUX_
  47 #define icmp_type type
  48 #define icmp_code code
  49 #define icmp_cksum checksum
  50 #define icmp_id un.echo.id
  51 #define icmp_seq un.echo.sequence
  52 #define icmp_gwaddr un.gateway
  53 #define ip_hl ihl
  54 #define ip_v version
  55 #define ip_tos tos
  56 #define ip_len tot_len
  57 #define ip_id id
  58 #define ip_off frag_off
  59 #define ip_ttl ttl
  60 #define ip_p protocol
  61 #define ip_sum check
  62 #define ip_src saddr
  63 #define ip_dst daddr
  64 #endif
  65
  66 #define MAX_PKT_SZ 8192
  67 #define MAX_PAYLOAD (MAX_PKT_SZ - sizeof(struct icmphdr) - sizeof (char) - sizeof(struct timeval) - 1)
  68
  69 typedef struct {
  70     struct timeval tv;
  71     unsigned char opcode;
  72     char payload[MAX_PAYLOAD];
  73 } icmpEchoData;
  74
  75 int icmp_ident = -1;
  76 int icmp_pkts_sent = 0;
  77
  78 static const char *icmpPktStr[] =
  79 {
  80     "Echo Reply",
  81     "ICMP 1",
  82     "ICMP 2",
  83     "Destination Unreachable",
  84     "Source Quench",
  85     "Redirect",
  86     "ICMP 6",
  87     "ICMP 7",
  88     "Echo",
  89     "ICMP 9",
  90     "ICMP 10",
  91     "Time Exceeded",
  92     "Parameter Problem",
  93     "Timestamp",
  94     "Timestamp Reply",
  95     "Info Request",
  96     "Info Reply",
  97     "Out of Range Type"
  98 };
  99
 100 static int in_cksum(unsigned short *ptr, int size);
 101 static void pingerRecv(void);
 102 static void pingerLog(struct icmphdr *, struct in_addr, int, int);
 103 static int ipHops(int ttl);
 104 static void pingerSendtoSquid(pingerReplyData * preply);
 105
 106 void
 107 pingerOpen(void)
 108 {
 109     struct protoent *proto = NULL;
 110     if ((proto = getprotobyname("icmp")) == 0) {
 111         debug(42, 0) ("pingerOpen: unknown protocol: icmp\n");
 112         exit(1);
 113     }
 114     icmp_sock = socket(PF_INET, SOCK_RAW, proto->p_proto);
 115     if (icmp_sock < 0) {
 116         debug(50, 0) ("pingerOpen: icmp_sock: %s\n", xstrerror());
 117         exit(1);
 118     }
 119     icmp_ident = getpid() & 0xffff;
 120     debug(42, 0) ("ICMP socket opened\n", icmp_sock);
 121 }
 122
 123 void
 124 pingerClose(void)
 125 {
 126     close(icmp_sock);
 127     icmp_sock = -1;
 128     icmp_ident = 0;
 129 }
 130
 131 static void
 132 pingerSendEcho(struct in_addr to, int opcode, char *payload, int len)
 133 {
 134     LOCAL_ARRAY(char, pkt, MAX_PKT_SZ);
 135     struct icmphdr *icmp = NULL;
 136     icmpEchoData *echo;
 137     int icmp_pktsize = sizeof(struct icmphdr);
 138     int x;
 139     struct sockaddr_in S;
 140     memset(pkt, '\0', MAX_PKT_SZ);
 141     icmp = (struct icmphdr *) (void *) pkt;
 142     icmp->icmp_type = ICMP_ECHO;
 143     icmp->icmp_code = 0;
 144     icmp->icmp_cksum = 0;
 145     icmp->icmp_id = icmp_ident;
 146     icmp->icmp_seq = icmp_pkts_sent++;
 147     echo = (icmpEchoData *) (icmp + 1);
 148     echo->opcode = (unsigned char) opcode;
 149     echo->tv = current_time;
 150     icmp_pktsize += sizeof(icmpEchoData) - MAX_PAYLOAD;
 151     if (payload) {
 152         if (len > MAX_PAYLOAD)
 153             len = MAX_PAYLOAD;
 154         xmemcpy(echo->payload, payload, len);
 155         icmp_pktsize += len;
 156     }
 157     icmp->icmp_cksum = in_cksum((u_short *) icmp, icmp_pktsize);
 158     S.sin_family = AF_INET;
 159     S.sin_addr = to;
 160     S.sin_port = 0;
 161     x = sendto(icmp_sock,
 162         pkt,
 163         icmp_pktsize,
 164         0,
 165         (struct sockaddr *) &S,
 166         sizeof(struct sockaddr_in));
 167     pingerLog(icmp, to, 0, 0);
 168 }
 169
 170 static void
 171 pingerRecv(void)
 172 {
 173     int n;
 174     int fromlen;
 175     struct sockaddr_in from;
 176     int iphdrlen = 20;
 177     struct iphdr *ip = NULL;
 178     struct icmphdr *icmp = NULL;
 179     LOCAL_ARRAY(char, pkt, MAX_PKT_SZ);
 180     struct timeval now;
 181     icmpEchoData *echo;
 182     static pingerReplyData preply;
 183
 184     fromlen = sizeof(from);
 185     n = recvfrom(icmp_sock,
 186         pkt,
 187         MAX_PKT_SZ,
 188         0,
 189         (struct sockaddr *) &from,
 190         &fromlen);
 191     gettimeofday(&now, NULL);
 192     debug(42, 9) ("pingerRecv: %d bytes from %s\n", n, inet_ntoa(from.sin_addr));
 193     ip = (struct iphdr *) (void *) pkt;
 194 #if HAVE_IP_HL
 195     iphdrlen = ip->ip_hl << 2;
 196 #else /* HAVE_IP_HL */
 197 #if WORDS_BIGENDIAN
 198     iphdrlen = (ip->ip_vhl >> 4) << 2;
 199 #else
 200     iphdrlen = (ip->ip_vhl & 0xF) << 2;
 201 #endif
 202 #endif /* HAVE_IP_HL */
 203     icmp = (struct icmphdr *) (void *) (pkt + iphdrlen);
 204     if (icmp->icmp_type != ICMP_ECHOREPLY)
 205         return;
 206     if (icmp->icmp_id != icmp_ident)
 207         return;
 208     echo = (icmpEchoData *) (void *) (icmp + 1);
 209     preply.from = from.sin_addr;
 210     preply.opcode = echo->opcode;
 211     preply.hops = ipHops(ip->ip_ttl);
 212     preply.rtt = tvSubMsec(echo->tv, now);
 213     preply.psize = n - iphdrlen - (sizeof(icmpEchoData) - MAX_PKT_SZ);
 214     pingerSendtoSquid(&preply);
 215     pingerLog(icmp, from.sin_addr, preply.rtt, preply.hops);
 216 }
 217
 218
 219 static int
 220 in_cksum(unsigned short *ptr, int size)
 221 {
 222     long sum;
 223     unsigned short oddbyte;
 224     unsigned short answer;
 225     sum = 0;
 226     while (size > 1) {
 227         sum += *ptr++;
 228         size -= 2;
 229     }
 230     if (size == 1) {
 231         oddbyte = 0;
 232         *((unsigned char *) &oddbyte) = *(unsigned char *) ptr;
 233         sum += oddbyte;
 234     }
 235     sum = (sum >> 16) + (sum & 0xffff);
 236     sum += (sum >> 16);
 237     answer = ~sum;
 238     return (answer);
 239 }
 240
 241 static void
 242 pingerLog(struct icmphdr *icmp, struct in_addr addr, int rtt, int hops)
 243 {
 244     debug(42, 2) ("pingerLog: %9d.%06d %-16s %d %-15.15s %dms %d hops\n",
 245         (int) current_time.tv_sec,
 246         (int) current_time.tv_usec,
 247         inet_ntoa(addr),
 248         (int) icmp->icmp_type,
 249         icmpPktStr[icmp->icmp_type],
 250         rtt,
 251         hops);
 252 }
 253
 254 static int
 255 ipHops(int ttl)
 256 {
 257     if (ttl < 33)
 258         return 33 - ttl;
 259     if (ttl < 63)
 260         return 63 - ttl;        /* 62 = (64+60)/2 */
 261     if (ttl < 65)
 262         return 65 - ttl;        /* 62 = (64+60)/2 */
 263     if (ttl < 129)
 264         return 129 - ttl;
 265     if (ttl < 193)
 266         return 193 - ttl;
 267     return 256 - ttl;
 268 }
 269
 270 static int
 271 pingerReadRequest(void)
 272 {
 273     static pingerEchoData pecho;
 274     int n;
 275     int guess_size;
 276     memset(&pecho, '\0', sizeof(pecho));
 277     n = recv(0, (char *) &pecho, sizeof(pecho), 0);
 278     if (n < 0)
 279         return n;
 280     guess_size = n - (sizeof(pingerEchoData) - MAX_PKT_SZ);
 281     if (guess_size != pecho.psize)
 282         fprintf(stderr, "size mismatch, guess=%d psize=%d\n",
 283             guess_size, pecho.psize);
 284     pingerSendEcho(pecho.to,
 285         pecho.opcode,
 286         pecho.payload,
 287         pecho.psize);
 288     return n;
 289 }
 290
 291 static void
 292 pingerSendtoSquid(pingerReplyData * preply)
 293 {
 294     int len = sizeof(pingerReplyData) - MAX_PKT_SZ + preply->psize;
 295     if (send(1, (char *) preply, len, 0) < 0) {
 296         debug(50, 0) ("pinger: send: %s\n", xstrerror());
 297         exit(1);
 298     }
 299 }
 300
 301 time_t
 302 getCurrentTime(void)
 303 {
 304 #if GETTIMEOFDAY_NO_TZP
 305     gettimeofday(&current_time);
 306 #else
 307     gettimeofday(&current_time, NULL);
 308 #endif
 309     return squid_curtime = current_time.tv_sec;
 310 }
 311
 312
 313 int
 314 main(int argc, char *argv[])
 315 {
 316     fd_set R;
 317     int x;
 318     struct timeval tv;
 319     const char *debug_args = "ALL,1";
 320     char *t;
 321     time_t last_check_time = 0;
 322
 323     if ((t = getenv("SQUID_DEBUG")))
 324         debug_args = xstrdup(t);
 325     getCurrentTime();
 326     _db_init(NULL, debug_args);
 327
 328     pingerOpen();
 329     for (;;) {
 330         tv.tv_sec = 10;
 331         tv.tv_usec = 0;
 332         FD_ZERO(&R);
 333         FD_SET(0, &R);
 334         FD_SET(icmp_sock, &R);
 335         x = select(icmp_sock + 1, &R, NULL, NULL, &tv);
 336         getCurrentTime();
 337         if (x < 0)
 338             return 1;
 339         if (FD_ISSET(0, &R))
 340             if (pingerReadRequest() < 0) {
 341                 debug(42, 0) ("Pinger exiting.\n");
 342                 return 1;
 343             }
 344         if (FD_ISSET(icmp_sock, &R))
 345             pingerRecv();
 346         if (10 + last_check_time < squid_curtime) {
 347             if (send(1, (char *) &tv, 0, 0) < 0)
 348                 return 1;
 349             last_check_time = squid_curtime;
 350         }
 351     }
 352     /* NOTREACHED */
 353 }
 354
 355 #else
 356 #include <stdio.h>
 357 int
 358 main(int argc, char *argv[])
 359 {
 360     fprintf(stderr, "%s: ICMP support not compiled in.\n", argv[0]);
 361     return 1;
 362 }
 363 #endif /* USE_ICMP */