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 "icmp/IcmpSquid.h"
  37 #include "icmp/net_db.h"
  38 #include "comm.h"
  39 #include "SquidTime.h"
  40
  41 // Instance global to be available in main() and elsewhere.
  42 IcmpSquid icmpEngine;
  43
  44 #if USE_ICMP
  45
  46 #define S_ICMP_ECHO     1
  47 #if DEAD_CODE
  48 #define S_ICMP_ICP      2
  49 #endif
  50 #define S_ICMP_DOM      3
  51
  52 static void * hIpc;
  53 static pid_t pid;
  54
  55 #endif /* USE_ICMP */
  56
  57
  58 IcmpSquid::IcmpSquid() : Icmp()
  59 {
  60     ; // nothing new.
  61 }
  62
  63 IcmpSquid::~IcmpSquid()
  64 {
  65     Close();
  66 }
  67
  68
  69 #if USE_ICMP
  70
  71 void
  72 IcmpSquid::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  73 {
  74     static pingerEchoData pecho;
  75     int x, slen;
  76
  77     /** \li Does nothing if the pinger socket is not available. */
  78     if (icmp_sock < 0) {
  79         debugs(37, 2, HERE << " Socket Closed. Aborted send to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  80         return;
  81     }
  82
  83     /** \li  If no payload is given or is set as NULL it will ignore payload and len */
  84     if (!payload)
  85         len = 0;
  86
  87     /** \li Otherwise if len is 0, uses strlen() to detect length of payload.
  88      \bug This will result in part of the payload being truncated if it contains a NULL character.
  89      \bug Or it may result in a buffer over-run if the payload is not nul-terminated properly.
  90      */
  91     else if (payload && len == 0)
  92         len = strlen(payload);
  93
  94     /** \li
  95      \bug If length specified or auto-detected is greater than the possible payload squid will die with an assert.
  96      \todo This should perhapse be reduced to a truncated payload? or no payload. A WARNING is due anyway.
  97      */
  98     assert(len <= PINGER_PAYLOAD_SZ);
  99
 100     pecho.to = to;
 101
 102     pecho.opcode = (unsigned char) opcode;
 103
 104     pecho.psize = len;
 105
 106     if (len > 0)
 107         xmemcpy(pecho.payload, payload, len);
 108
 109     slen = sizeof(pingerEchoData) - PINGER_PAYLOAD_SZ + pecho.psize;
 110
 111     debugs(37, 2, HERE << "to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
 112
 113     x = comm_udp_send(icmp_sock, (char *)&pecho, slen, 0);
 114
 115     if (x < 0) {
 116         debugs(37, 1, HERE << "send: " << xstrerror());
 117
 118         /** \li  If the send results in ECONNREFUSED or EPIPE errors from helper, will cleanly shutdown the module. */
 119         /** \todo This should try restarting the helper a few times?? before giving up? */
 120         if (errno == ECONNREFUSED || errno == EPIPE) {
 121             Close();
 122             return;
 123         }
 124         /** All other send errors are ignored. */
 125     } else if (x != slen) {
 126         debugs(37, 1, HERE << "Wrote " << x << " of " << slen << " bytes");
 127     }
 128 }
 129
 130 // static Callback to wrap the squid-side ICMP handler.
 131 // the IcmpSquid::Recv cannot be declared both static and virtual.
 132 static void
 133 icmpSquidRecv(int unused1, void *unused2)
 134 {
 135     icmpEngine.Recv();
 136 }
 137
 138 void
 139 IcmpSquid::Recv()
 140 {
 141     int n;
 142     static int fail_count = 0;
 143     pingerReplyData preply;
 144     static Ip::Address F;
 145
 146     commSetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 147     memset(&preply, '\0', sizeof(pingerReplyData));
 148     n = comm_udp_recv(icmp_sock,
 149                       (char *) &preply,
 150                       sizeof(pingerReplyData),
 151                       0);
 152
 153     if (n < 0 && EAGAIN != errno) {
 154         debugs(37, 1, HERE << "recv: " << xstrerror());
 155
 156         if (errno == ECONNREFUSED)
 157             Close();
 158
 159         if (errno == ECONNRESET)
 160             Close();
 161
 162         if (++fail_count == 10)
 163             Close();
 164
 165         return;
 166     }
 167
 168     fail_count = 0;
 169
 170     /** If its a test probe from the pinger. Do nothing. */
 171     if (n == 0) {
 172         return;
 173     }
 174
 175     F = preply.from;
 176
 177     F.SetPort(0);
 178
 179     switch (preply.opcode) {
 180
 181     case S_ICMP_ECHO:
 182         debugs(37,4, HERE << " ICMP_ECHO of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 183         break;
 184
 185     case S_ICMP_DOM:
 186         debugs(37,4, HERE << " DomainPing of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 187         netdbHandlePingReply(F, preply.hops, preply.rtt);
 188         break;
 189
 190     default:
 191         debugs(37, 1, HERE << "Bad opcode: " << preply.opcode << " from " << F);
 192         break;
 193     }
 194 }
 195
 196 #endif /* USE_ICMP */
 197
 198 void
 199 IcmpSquid::DomainPing(Ip::Address &to, const char *domain)
 200 {
 201 #if USE_ICMP
 202     debugs(37, 4, HERE << "'" << domain << "' (" << to << ")");
 203     SendEcho(to, S_ICMP_DOM, domain, 0);
 204 #endif
 205 }
 206
 207 int
 208 IcmpSquid::Open(void)
 209 {
 210 #if USE_ICMP
 211     const char *args[2];
 212     int rfd;
 213     int wfd;
 214     Ip::Address localhost;
 215
 216     /* User configured disabled. */
 217     if (!Config.pinger.enable) {
 218         Close();
 219         return -1;
 220     }
 221
 222     args[0] = "(pinger)";
 223     args[1] = NULL;
 224     localhost.SetLocalhost();
 225
 226     /*
 227      * Do NOT use IPC_DGRAM (=IPC_UNIX_DGRAM) here because you can't
 228      * send() more than 4096 bytes on a socketpair() socket (at
 229      * least on FreeBSD).
 230      */
 231     pid = ipcCreate(IPC_UDP_SOCKET,
 232                     Config.pinger.program,
 233                     args,
 234                     "Pinger Socket",
 235                     localhost,
 236                     &rfd,
 237                     &wfd,
 238                     &hIpc);
 239
 240     if (pid < 0)
 241         return -1;
 242
 243     assert(rfd == wfd);
 244
 245     icmp_sock = rfd;
 246
 247     fd_note(icmp_sock, "pinger");
 248
 249     commSetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 250
 251     commSetTimeout(icmp_sock, -1, NULL, NULL);
 252
 253     debugs(37, 1, HERE << "Pinger socket opened on FD " << icmp_sock);
 254
 255     /* Tests the pinger immediately using localhost */
 256 #if USE_IPV6
 257     SendEcho(localhost, S_ICMP_ECHO, "ip6-localhost");
 258 #endif
 259     if (localhost.SetIPv4())
 260         SendEcho(localhost, S_ICMP_ECHO, "localhost");
 261
 262 #ifdef _SQUID_MSWIN_
 263
 264     debugs(37, 4, HERE << "Pinger handle: 0x" << std::hex << hIpc << std::dec << ", PID: " << pid);
 265
 266 #endif /* _SQUID_MSWIN_ */
 267     return icmp_sock;
 268 #else /* USE_ICMP */
 269     return -1;
 270 #endif /* USE_ICMP */
 271 }
 272
 273 void
 274 IcmpSquid::Close(void)
 275 {
 276 #if USE_ICMP
 277
 278     if (icmp_sock < 0)
 279         return;
 280
 281     debugs(37, 1, HERE << "Closing Pinger socket on FD " << icmp_sock);
 282
 283 #ifdef _SQUID_MSWIN_
 284
 285     send(icmp_sock, (const void *) "$shutdown\n", 10, 0);
 286
 287 #endif
 288
 289     comm_close(icmp_sock);
 290
 291 #ifdef _SQUID_MSWIN_
 292
 293     if (hIpc) {
 294         if (WaitForSingleObject(hIpc, 12000) != WAIT_OBJECT_0) {
 295             getCurrentTime();
 296             debugs(37, 0, HERE << "WARNING: (pinger," << pid << ") didn't exit in 12 seconds");
 297         }
 298
 299         CloseHandle(hIpc);
 300     }
 301
 302 #endif
 303     icmp_sock = -1;
 304
 305 #endif
 306 }