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 IcmpSquid::IcmpSquid() : Icmp()
  65 {
  66     ; // nothing new.
  67 }
  68
  69 IcmpSquid::~IcmpSquid()
  70 {
  71     Close();
  72 }
  73
  74 #if USE_ICMP
  75
  76 void
  77 IcmpSquid::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  78 {
  79     static pingerEchoData pecho;
  80     int x, slen;
  81
  82     /** \li Does nothing if the pinger socket is not available. */
  83     if (icmp_sock < 0) {
  84         debugs(37, 2, HERE << " Socket Closed. Aborted send to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  85         return;
  86     }
  87
  88     /** \li  If no payload is given or is set as NULL it will ignore payload and len */
  89     if (!payload)
  90         len = 0;
  91
  92     /** \li Otherwise if len is 0, uses strlen() to detect length of payload.
  93      \bug This will result in part of the payload being truncated if it contains a NULL character.
  94      \bug Or it may result in a buffer over-run if the payload is not nul-terminated properly.
  95      */
  96     else if (payload && len == 0)
  97         len = strlen(payload);
  98
  99     /** \li
 100      \bug If length specified or auto-detected is greater than the possible payload squid will die with an assert.
 101      \todo This should perhapse be reduced to a truncated payload? or no payload. A WARNING is due anyway.
 102      */
 103     assert(len <= PINGER_PAYLOAD_SZ);
 104
 105     pecho.to = to;
 106
 107     pecho.opcode = (unsigned char) opcode;
 108
 109     pecho.psize = len;
 110
 111     if (len > 0)
 112         memcpy(pecho.payload, payload, len);
 113
 114     slen = sizeof(pingerEchoData) - PINGER_PAYLOAD_SZ + pecho.psize;
 115
 116     debugs(37, 2, HERE << "to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
 117
 118     x = comm_udp_send(icmp_sock, (char *)&pecho, slen, 0);
 119
 120     if (x < 0) {
 121         debugs(37, DBG_IMPORTANT, HERE << "send: " << xstrerror());
 122
 123         /** \li  If the send results in ECONNREFUSED or EPIPE errors from helper, will cleanly shutdown the module. */
 124         /** \todo This should try restarting the helper a few times?? before giving up? */
 125         if (errno == ECONNREFUSED || errno == EPIPE) {
 126             Close();
 127             return;
 128         }
 129         /** All other send errors are ignored. */
 130     } else if (x != slen) {
 131         debugs(37, DBG_IMPORTANT, HERE << "Wrote " << x << " of " << slen << " bytes");
 132     }
 133 }
 134
 135 // static Callback to wrap the squid-side ICMP handler.
 136 // the IcmpSquid::Recv cannot be declared both static and virtual.
 137 static void
 138 icmpSquidRecv(int unused1, void *unused2)
 139 {
 140     icmpEngine.Recv();
 141 }
 142
 143 void
 144 IcmpSquid::Recv()
 145 {
 146     int n;
 147     static int fail_count = 0;
 148     pingerReplyData preply;
 149     static Ip::Address F;
 150
 151     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 152     memset(&preply, '\0', sizeof(pingerReplyData));
 153     n = comm_udp_recv(icmp_sock,
 154                       (char *) &preply,
 155                       sizeof(pingerReplyData),
 156                       0);
 157
 158     if (n < 0 && EAGAIN != errno) {
 159         debugs(37, DBG_IMPORTANT, HERE << "recv: " << xstrerror());
 160
 161         if (errno == ECONNREFUSED)
 162             Close();
 163
 164         if (errno == ECONNRESET)
 165             Close();
 166
 167         if (++fail_count == 10)
 168             Close();
 169
 170         return;
 171     }
 172
 173     fail_count = 0;
 174
 175     /** If its a test probe from the pinger. Do nothing. */
 176     if (n == 0) {
 177         return;
 178     }
 179
 180     F = preply.from;
 181
 182     F.SetPort(0);
 183
 184     switch (preply.opcode) {
 185
 186     case S_ICMP_ECHO:
 187         debugs(37,4, HERE << " ICMP_ECHO of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 188         break;
 189
 190     case S_ICMP_DOM:
 191         debugs(37,4, HERE << " DomainPing of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 192         netdbHandlePingReply(F, preply.hops, preply.rtt);
 193         break;
 194
 195     default:
 196         debugs(37, DBG_IMPORTANT, HERE << "Bad opcode: " << preply.opcode << " from " << F);
 197         break;
 198     }
 199 }
 200
 201 #endif /* USE_ICMP */
 202
 203 void
 204 IcmpSquid::DomainPing(Ip::Address &to, const char *domain)
 205 {
 206 #if USE_ICMP
 207     debugs(37, 4, HERE << "'" << domain << "' (" << to << ")");
 208     SendEcho(to, S_ICMP_DOM, domain, 0);
 209 #endif
 210 }
 211
 212 int
 213 IcmpSquid::Open(void)
 214 {
 215 #if USE_ICMP
 216     const char *args[2];
 217     int rfd;
 218     int wfd;
 219     Ip::Address localhost;
 220
 221     /* User configured disabled. */
 222     if (!Config.pinger.enable) {
 223         Close();
 224         return -1;
 225     }
 226
 227     args[0] = "(pinger)";
 228     args[1] = NULL;
 229     localhost.SetLocalhost();
 230
 231     /*
 232      * Do NOT use IPC_DGRAM (=IPC_UNIX_DGRAM) here because you can't
 233      * send() more than 4096 bytes on a socketpair() socket (at
 234      * least on FreeBSD).
 235      */
 236     pid = ipcCreate(IPC_UDP_SOCKET,
 237                     Config.pinger.program,
 238                     args,
 239                     "Pinger Socket",
 240                     localhost,
 241                     &rfd,
 242                     &wfd,
 243                     &hIpc);
 244
 245     if (pid < 0)
 246         return -1;
 247
 248     assert(rfd == wfd);
 249
 250     icmp_sock = rfd;
 251
 252     fd_note(icmp_sock, "pinger");
 253
 254     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 255
 256     commUnsetFdTimeout(icmp_sock);
 257
 258     debugs(37, DBG_IMPORTANT, HERE << "Pinger socket opened on FD " << icmp_sock);
 259
 260     /* Tests the pinger immediately using localhost */
 261     if (Ip::EnableIpv6)
 262         SendEcho(localhost, S_ICMP_ECHO, "ip6-localhost");
 263     if (localhost.SetIPv4())
 264         SendEcho(localhost, S_ICMP_ECHO, "localhost");
 265
 266 #if _SQUID_MSWIN_
 267
 268     debugs(37, 4, HERE << "Pinger handle: 0x" << std::hex << hIpc << std::dec << ", PID: " << pid);
 269
 270 #endif /* _SQUID_MSWIN_ */
 271     return icmp_sock;
 272 #else /* USE_ICMP */
 273     return -1;
 274 #endif /* USE_ICMP */
 275 }
 276
 277 void
 278 IcmpSquid::Close(void)
 279 {
 280 #if USE_ICMP
 281
 282     if (icmp_sock < 0)
 283         return;
 284
 285     debugs(37, DBG_IMPORTANT, HERE << "Closing Pinger socket on FD " << icmp_sock);
 286
 287 #if _SQUID_MSWIN_
 288
 289     send(icmp_sock, (const void *) "$shutdown\n", 10, 0);
 290
 291 #endif
 292
 293     comm_close(icmp_sock);
 294
 295 #if _SQUID_MSWIN_
 296
 297     if (hIpc) {
 298         if (WaitForSingleObject(hIpc, 12000) != WAIT_OBJECT_0) {
 299             getCurrentTime();
 300             debugs(37, DBG_CRITICAL, HERE << "WARNING: (pinger," << pid << ") didn't exit in 12 seconds");
 301         }
 302
 303         CloseHandle(hIpc);
 304     }
 305
 306 #endif
 307     icmp_sock = -1;
 308
 309 #endif
 310 }