src/icmp/IcmpSquid.cc

   1 /*
   2  * DEBUG: section 37    ICMP Routines
   3  * AUTHOR: Duane Wessels, Amos Jeffries
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32
  33 #include "squid.h"
  34 #include "comm.h"
  35 #include "comm/Loops.h"
  36 #include "defines.h"
  37 #include "fd.h"
  38 #include "icmp/IcmpSquid.h"
  39 #include "icmp/net_db.h"
  40 #include "ip/tools.h"
  41 #include "SquidConfig.h"
  42 #include "SquidIpc.h"
  43 #include "SquidTime.h"
  44
  45 #if HAVE_ERRNO_H
  46 #include <errno.h>
  47 #endif
  48
  49 // Instance global to be available in main() and elsewhere.
  50 IcmpSquid icmpEngine;
  51
  52 #if USE_ICMP
  53
  54 #define S_ICMP_ECHO     1
  55 #define S_ICMP_DOM      3
  56
  57 static void * hIpc;
  58 static pid_t pid;
  59
  60 #endif /* USE_ICMP */
  61
  62 IcmpSquid::IcmpSquid() : Icmp()
  63 {
  64     ; // nothing new.
  65 }
  66
  67 IcmpSquid::~IcmpSquid()
  68 {
  69     Close();
  70 }
  71
  72 #if USE_ICMP
  73
  74 void
  75 IcmpSquid::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  76 {
  77     static pingerEchoData pecho;
  78     int x, slen;
  79
  80     /** \li Does nothing if the pinger socket is not available. */
  81     if (icmp_sock < 0) {
  82         debugs(37, 2, HERE << " Socket Closed. Aborted send to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  83         return;
  84     }
  85
  86     /** \li  If no payload is given or is set as NULL it will ignore payload and len */
  87     if (!payload)
  88         len = 0;
  89
  90     /** \li Otherwise if len is 0, uses strlen() to detect length of payload.
  91      \bug This will result in part of the payload being truncated if it contains a NULL character.
  92      \bug Or it may result in a buffer over-run if the payload is not nul-terminated properly.
  93      */
  94     else if (payload && len == 0)
  95         len = strlen(payload);
  96
  97     /** \li
  98      \bug If length specified or auto-detected is greater than the possible payload squid will die with an assert.
  99      \todo This should perhapse be reduced to a truncated payload? or no payload. A WARNING is due anyway.
 100      */
 101     assert(len <= PINGER_PAYLOAD_SZ);
 102
 103     pecho.to = to;
 104
 105     pecho.opcode = (unsigned char) opcode;
 106
 107     pecho.psize = len;
 108
 109     if (len > 0)
 110         memcpy(pecho.payload, payload, len);
 111
 112     slen = sizeof(pingerEchoData) - PINGER_PAYLOAD_SZ + pecho.psize;
 113
 114     debugs(37, 2, HERE << "to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
 115
 116     x = comm_udp_send(icmp_sock, (char *)&pecho, slen, 0);
 117
 118     if (x < 0) {
 119         debugs(37, DBG_IMPORTANT, HERE << "send: " << xstrerror());
 120
 121         /** \li  If the send results in ECONNREFUSED or EPIPE errors from helper, will cleanly shutdown the module. */
 122         /** \todo This should try restarting the helper a few times?? before giving up? */
 123         if (errno == ECONNREFUSED || errno == EPIPE) {
 124             Close();
 125             return;
 126         }
 127         /** All other send errors are ignored. */
 128     } else if (x != slen) {
 129         debugs(37, DBG_IMPORTANT, HERE << "Wrote " << x << " of " << slen << " bytes");
 130     }
 131 }
 132
 133 // static Callback to wrap the squid-side ICMP handler.
 134 // the IcmpSquid::Recv cannot be declared both static and virtual.
 135 static void
 136 icmpSquidRecv(int unused1, void *unused2)
 137 {
 138     icmpEngine.Recv();
 139 }
 140
 141 void
 142 IcmpSquid::Recv()
 143 {
 144     int n;
 145     static int fail_count = 0;
 146     pingerReplyData preply;
 147     static Ip::Address F;
 148
 149     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 150     memset(&preply, '\0', sizeof(pingerReplyData));
 151     n = comm_udp_recv(icmp_sock,
 152                       (char *) &preply,
 153                       sizeof(pingerReplyData),
 154                       0);
 155
 156     if (n < 0 && EAGAIN != errno) {
 157         debugs(37, DBG_IMPORTANT, HERE << "recv: " << xstrerror());
 158
 159         if (errno == ECONNREFUSED)
 160             Close();
 161
 162         if (errno == ECONNRESET)
 163             Close();
 164
 165         if (++fail_count == 10)
 166             Close();
 167
 168         return;
 169     }
 170
 171     fail_count = 0;
 172
 173     /** If its a test probe from the pinger. Do nothing. */
 174     if (n == 0) {
 175         return;
 176     }
 177
 178     F = preply.from;
 179
 180     F.port(0);
 181
 182     switch (preply.opcode) {
 183
 184     case S_ICMP_ECHO:
 185         debugs(37,4, HERE << " ICMP_ECHO of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 186         break;
 187
 188     case S_ICMP_DOM:
 189         debugs(37,4, HERE << " DomainPing of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 190         netdbHandlePingReply(F, preply.hops, preply.rtt);
 191         break;
 192
 193     default:
 194         debugs(37, DBG_IMPORTANT, HERE << "Bad opcode: " << preply.opcode << " from " << F);
 195         break;
 196     }
 197 }
 198
 199 #endif /* USE_ICMP */
 200
 201 void
 202 IcmpSquid::DomainPing(Ip::Address &to, const char *domain)
 203 {
 204 #if USE_ICMP
 205     debugs(37, 4, HERE << "'" << domain << "' (" << to << ")");
 206     SendEcho(to, S_ICMP_DOM, domain, 0);
 207 #endif
 208 }
 209
 210 int
 211 IcmpSquid::Open(void)
 212 {
 213 #if USE_ICMP
 214     const char *args[2];
 215     int rfd;
 216     int wfd;
 217     Ip::Address localhost;
 218
 219     /* User configured disabled. */
 220     if (!Config.pinger.enable) {
 221         Close();
 222         return -1;
 223     }
 224
 225     args[0] = "(pinger)";
 226     args[1] = NULL;
 227     localhost.setLocalhost();
 228
 229     /*
 230      * Do NOT use IPC_DGRAM (=IPC_UNIX_DGRAM) here because you can't
 231      * send() more than 4096 bytes on a socketpair() socket (at
 232      * least on FreeBSD).
 233      */
 234     pid = ipcCreate(IPC_UDP_SOCKET,
 235                     Config.pinger.program,
 236                     args,
 237                     "Pinger Socket",
 238                     localhost,
 239                     &rfd,
 240                     &wfd,
 241                     &hIpc);
 242
 243     if (pid < 0)
 244         return -1;
 245
 246     assert(rfd == wfd);
 247
 248     icmp_sock = rfd;
 249
 250     fd_note(icmp_sock, "pinger");
 251
 252     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 253
 254     commUnsetFdTimeout(icmp_sock);
 255
 256     debugs(37, DBG_IMPORTANT, HERE << "Pinger socket opened on FD " << icmp_sock);
 257
 258     /* Tests the pinger immediately using localhost */
 259     if (Ip::EnableIpv6)
 260         SendEcho(localhost, S_ICMP_ECHO, "ip6-localhost");
 261     if (localhost.setIPv4())
 262         SendEcho(localhost, S_ICMP_ECHO, "localhost");
 263
 264 #if _SQUID_WINDOWS_
 265
 266     debugs(37, 4, HERE << "Pinger handle: 0x" << std::hex << hIpc << std::dec << ", PID: " << pid);
 267
 268 #endif /* _SQUID_WINDOWS_ */
 269     return icmp_sock;
 270 #else /* USE_ICMP */
 271     return -1;
 272 #endif /* USE_ICMP */
 273 }
 274
 275 void
 276 IcmpSquid::Close(void)
 277 {
 278 #if USE_ICMP
 279
 280     if (icmp_sock < 0)
 281         return;
 282
 283     debugs(37, DBG_IMPORTANT, HERE << "Closing Pinger socket on FD " << icmp_sock);
 284
 285 #if _SQUID_WINDOWS_
 286
 287     send(icmp_sock, (const void *) "$shutdown\n", 10, 0);
 288
 289 #endif
 290
 291     comm_close(icmp_sock);
 292
 293 #if _SQUID_WINDOWS_
 294
 295     if (hIpc) {
 296         if (WaitForSingleObject(hIpc, 12000) != WAIT_OBJECT_0) {
 297             getCurrentTime();
 298             debugs(37, DBG_CRITICAL, HERE << "WARNING: (pinger," << pid << ") didn't exit in 12 seconds");
 299         }
 300
 301         CloseHandle(hIpc);
 302     }
 303
 304 #endif
 305     icmp_sock = -1;
 306
 307 #endif
 308 }