src/icmp/IcmpSquid.cc

   1 /*
   2  * $Id$
   3  *
   4  * DEBUG: section 37    ICMP Routines
   5  * AUTHOR: Duane Wessels, Amos Jeffries
   6  *
   7  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   8  * ----------------------------------------------------------
   9  *
  10  *  Squid is the result of efforts by numerous individuals from
  11  *  the Internet community; see the CONTRIBUTORS file for full
  12  *  details.   Many organizations have provided support for Squid's
  13  *  development; see the SPONSORS file for full details.  Squid is
  14  *  Copyrighted (C) 2001 by the Regents of the University of
  15  *  California; see the COPYRIGHT file for full details.  Squid
  16  *  incorporates software developed and/or copyrighted by other
  17  *  sources; see the CREDITS file for full details.
  18  *
  19  *  This program is free software; you can redistribute it and/or modify
  20  *  it under the terms of the GNU General Public License as published by
  21  *  the Free Software Foundation; either version 2 of the License, or
  22  *  (at your option) any later version.
  23  *
  24  *  This program is distributed in the hope that it will be useful,
  25  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  *  GNU General Public License for more details.
  28  *
  29  *  You should have received a copy of the GNU General Public License
  30  *  along with this program; if not, write to the Free Software
  31  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  32  *
  33  */
  34
  35 #include "squid.h"
  36 #include "comm.h"
  37 #include "comm/Loops.h"
  38 #include "icmp/IcmpSquid.h"
  39 #include "icmp/net_db.h"
  40 #include "ip/tools.h"
  41 #include "protos.h"
  42 #include "SquidTime.h"
  43
  44 #if HAVE_ERRNO_H
  45 #include <errno.h>
  46 #endif
  47
  48 // Instance global to be available in main() and elsewhere.
  49 IcmpSquid icmpEngine;
  50
  51 #if USE_ICMP
  52
  53 #define S_ICMP_ECHO     1
  54 #if DEAD_CODE
  55 #define S_ICMP_ICP      2
  56 #endif
  57 #define S_ICMP_DOM      3
  58
  59 static void * hIpc;
  60 static pid_t pid;
  61
  62 #endif /* USE_ICMP */
  63
  64
  65 IcmpSquid::IcmpSquid() : Icmp()
  66 {
  67     ; // nothing new.
  68 }
  69
  70 IcmpSquid::~IcmpSquid()
  71 {
  72     Close();
  73 }
  74
  75
  76 #if USE_ICMP
  77
  78 void
  79 IcmpSquid::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  80 {
  81     static pingerEchoData pecho;
  82     int x, slen;
  83
  84     /** \li Does nothing if the pinger socket is not available. */
  85     if (icmp_sock < 0) {
  86         debugs(37, 2, HERE << " Socket Closed. Aborted send to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  87         return;
  88     }
  89
  90     /** \li  If no payload is given or is set as NULL it will ignore payload and len */
  91     if (!payload)
  92         len = 0;
  93
  94     /** \li Otherwise if len is 0, uses strlen() to detect length of payload.
  95      \bug This will result in part of the payload being truncated if it contains a NULL character.
  96      \bug Or it may result in a buffer over-run if the payload is not nul-terminated properly.
  97      */
  98     else if (payload && len == 0)
  99         len = strlen(payload);
 100
 101     /** \li
 102      \bug If length specified or auto-detected is greater than the possible payload squid will die with an assert.
 103      \todo This should perhapse be reduced to a truncated payload? or no payload. A WARNING is due anyway.
 104      */
 105     assert(len <= PINGER_PAYLOAD_SZ);
 106
 107     pecho.to = to;
 108
 109     pecho.opcode = (unsigned char) opcode;
 110
 111     pecho.psize = len;
 112
 113     if (len > 0)
 114         memcpy(pecho.payload, payload, len);
 115
 116     slen = sizeof(pingerEchoData) - PINGER_PAYLOAD_SZ + pecho.psize;
 117
 118     debugs(37, 2, HERE << "to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
 119
 120     x = comm_udp_send(icmp_sock, (char *)&pecho, slen, 0);
 121
 122     if (x < 0) {
 123         debugs(37, DBG_IMPORTANT, HERE << "send: " << xstrerror());
 124
 125         /** \li  If the send results in ECONNREFUSED or EPIPE errors from helper, will cleanly shutdown the module. */
 126         /** \todo This should try restarting the helper a few times?? before giving up? */
 127         if (errno == ECONNREFUSED || errno == EPIPE) {
 128             Close();
 129             return;
 130         }
 131         /** All other send errors are ignored. */
 132     } else if (x != slen) {
 133         debugs(37, DBG_IMPORTANT, HERE << "Wrote " << x << " of " << slen << " bytes");
 134     }
 135 }
 136
 137 // static Callback to wrap the squid-side ICMP handler.
 138 // the IcmpSquid::Recv cannot be declared both static and virtual.
 139 static void
 140 icmpSquidRecv(int unused1, void *unused2)
 141 {
 142     icmpEngine.Recv();
 143 }
 144
 145 void
 146 IcmpSquid::Recv()
 147 {
 148     int n;
 149     static int fail_count = 0;
 150     pingerReplyData preply;
 151     static Ip::Address F;
 152
 153     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 154     memset(&preply, '\0', sizeof(pingerReplyData));
 155     n = comm_udp_recv(icmp_sock,
 156                       (char *) &preply,
 157                       sizeof(pingerReplyData),
 158                       0);
 159
 160     if (n < 0 && EAGAIN != errno) {
 161         debugs(37, DBG_IMPORTANT, HERE << "recv: " << xstrerror());
 162
 163         if (errno == ECONNREFUSED)
 164             Close();
 165
 166         if (errno == ECONNRESET)
 167             Close();
 168
 169         if (++fail_count == 10)
 170             Close();
 171
 172         return;
 173     }
 174
 175     fail_count = 0;
 176
 177     /** If its a test probe from the pinger. Do nothing. */
 178     if (n == 0) {
 179         return;
 180     }
 181
 182     F = preply.from;
 183
 184     F.SetPort(0);
 185
 186     switch (preply.opcode) {
 187
 188     case S_ICMP_ECHO:
 189         debugs(37,4, HERE << " ICMP_ECHO of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 190         break;
 191
 192     case S_ICMP_DOM:
 193         debugs(37,4, HERE << " DomainPing of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 194         netdbHandlePingReply(F, preply.hops, preply.rtt);
 195         break;
 196
 197     default:
 198         debugs(37, DBG_IMPORTANT, HERE << "Bad opcode: " << preply.opcode << " from " << F);
 199         break;
 200     }
 201 }
 202
 203 #endif /* USE_ICMP */
 204
 205 void
 206 IcmpSquid::DomainPing(Ip::Address &to, const char *domain)
 207 {
 208 #if USE_ICMP
 209     debugs(37, 4, HERE << "'" << domain << "' (" << to << ")");
 210     SendEcho(to, S_ICMP_DOM, domain, 0);
 211 #endif
 212 }
 213
 214 int
 215 IcmpSquid::Open(void)
 216 {
 217 #if USE_ICMP
 218     const char *args[2];
 219     int rfd;
 220     int wfd;
 221     Ip::Address localhost;
 222
 223     /* User configured disabled. */
 224     if (!Config.pinger.enable) {
 225         Close();
 226         return -1;
 227     }
 228
 229     args[0] = "(pinger)";
 230     args[1] = NULL;
 231     localhost.SetLocalhost();
 232
 233     /*
 234      * Do NOT use IPC_DGRAM (=IPC_UNIX_DGRAM) here because you can't
 235      * send() more than 4096 bytes on a socketpair() socket (at
 236      * least on FreeBSD).
 237      */
 238     pid = ipcCreate(IPC_UDP_SOCKET,
 239                     Config.pinger.program,
 240                     args,
 241                     "Pinger Socket",
 242                     localhost,
 243                     &rfd,
 244                     &wfd,
 245                     &hIpc);
 246
 247     if (pid < 0)
 248         return -1;
 249
 250     assert(rfd == wfd);
 251
 252     icmp_sock = rfd;
 253
 254     fd_note(icmp_sock, "pinger");
 255
 256     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 257
 258     commUnsetFdTimeout(icmp_sock);
 259
 260     debugs(37, DBG_IMPORTANT, HERE << "Pinger socket opened on FD " << icmp_sock);
 261
 262     /* Tests the pinger immediately using localhost */
 263     if (Ip::EnableIpv6)
 264         SendEcho(localhost, S_ICMP_ECHO, "ip6-localhost");
 265     if (localhost.SetIPv4())
 266         SendEcho(localhost, S_ICMP_ECHO, "localhost");
 267
 268 #if _SQUID_MSWIN_
 269
 270     debugs(37, 4, HERE << "Pinger handle: 0x" << std::hex << hIpc << std::dec << ", PID: " << pid);
 271
 272 #endif /* _SQUID_MSWIN_ */
 273     return icmp_sock;
 274 #else /* USE_ICMP */
 275     return -1;
 276 #endif /* USE_ICMP */
 277 }
 278
 279 void
 280 IcmpSquid::Close(void)
 281 {
 282 #if USE_ICMP
 283
 284     if (icmp_sock < 0)
 285         return;
 286
 287     debugs(37, DBG_IMPORTANT, HERE << "Closing Pinger socket on FD " << icmp_sock);
 288
 289 #if _SQUID_MSWIN_
 290
 291     send(icmp_sock, (const void *) "$shutdown\n", 10, 0);
 292
 293 #endif
 294
 295     comm_close(icmp_sock);
 296
 297 #if _SQUID_MSWIN_
 298
 299     if (hIpc) {
 300         if (WaitForSingleObject(hIpc, 12000) != WAIT_OBJECT_0) {
 301             getCurrentTime();
 302             debugs(37, DBG_CRITICAL, HERE << "WARNING: (pinger," << pid << ") didn't exit in 12 seconds");
 303         }
 304
 305         CloseHandle(hIpc);
 306     }
 307
 308 #endif
 309     icmp_sock = -1;
 310
 311 #endif
 312 }