src/icmp/IcmpSquid.cc

   1 /*
   2  * Copyright (C) 1996-2014 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 37    ICMP Routines */
  10
  11 #include "squid.h"
  12 #include "comm.h"
  13 #include "comm/Loops.h"
  14 #include "defines.h"
  15 #include "fd.h"
  16 #include "icmp/IcmpSquid.h"
  17 #include "icmp/net_db.h"
  18 #include "ip/tools.h"
  19 #include "SquidConfig.h"
  20 #include "SquidIpc.h"
  21 #include "SquidTime.h"
  22
  23 #include <cerrno>
  24
  25 // Instance global to be available in main() and elsewhere.
  26 IcmpSquid icmpEngine;
  27
  28 #if USE_ICMP
  29
  30 #define S_ICMP_ECHO     1
  31 #define S_ICMP_DOM      3
  32
  33 static void * hIpc;
  34 static pid_t pid;
  35
  36 #endif /* USE_ICMP */
  37
  38 IcmpSquid::IcmpSquid() : Icmp()
  39 {
  40     ; // nothing new.
  41 }
  42
  43 IcmpSquid::~IcmpSquid()
  44 {
  45     Close();
  46 }
  47
  48 #if USE_ICMP
  49
  50 void
  51 IcmpSquid::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  52 {
  53     static pingerEchoData pecho;
  54     int x, slen;
  55
  56     /** \li Does nothing if the pinger socket is not available. */
  57     if (icmp_sock < 0) {
  58         debugs(37, 2, HERE << " Socket Closed. Aborted send to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  59         return;
  60     }
  61
  62     /** \li  If no payload is given or is set as NULL it will ignore payload and len */
  63     if (!payload)
  64         len = 0;
  65
  66     /** \li Otherwise if len is 0, uses strlen() to detect length of payload.
  67      \bug This will result in part of the payload being truncated if it contains a NULL character.
  68      \bug Or it may result in a buffer over-run if the payload is not nul-terminated properly.
  69      */
  70     else if (payload && len == 0)
  71         len = strlen(payload);
  72
  73     /** \li
  74      \bug If length specified or auto-detected is greater than the possible payload squid will die with an assert.
  75      \todo This should perhapse be reduced to a truncated payload? or no payload. A WARNING is due anyway.
  76      */
  77     assert(len <= PINGER_PAYLOAD_SZ);
  78
  79     pecho.to = to;
  80
  81     pecho.opcode = (unsigned char) opcode;
  82
  83     pecho.psize = len;
  84
  85     if (len > 0)
  86         memcpy(pecho.payload, payload, len);
  87
  88     slen = sizeof(pingerEchoData) - PINGER_PAYLOAD_SZ + pecho.psize;
  89
  90     debugs(37, 2, HERE << "to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  91
  92     x = comm_udp_send(icmp_sock, (char *)&pecho, slen, 0);
  93
  94     if (x < 0) {
  95         debugs(37, DBG_IMPORTANT, HERE << "send: " << xstrerror());
  96
  97         /** \li  If the send results in ECONNREFUSED or EPIPE errors from helper, will cleanly shutdown the module. */
  98         /** \todo This should try restarting the helper a few times?? before giving up? */
  99         if (errno == ECONNREFUSED || errno == EPIPE) {
 100             Close();
 101             return;
 102         }
 103         /** All other send errors are ignored. */
 104     } else if (x != slen) {
 105         debugs(37, DBG_IMPORTANT, HERE << "Wrote " << x << " of " << slen << " bytes");
 106     }
 107 }
 108
 109 // static Callback to wrap the squid-side ICMP handler.
 110 // the IcmpSquid::Recv cannot be declared both static and virtual.
 111 static void
 112 icmpSquidRecv(int unused1, void *unused2)
 113 {
 114     icmpEngine.Recv();
 115 }
 116
 117 void
 118 IcmpSquid::Recv()
 119 {
 120     int n;
 121     static int fail_count = 0;
 122     pingerReplyData preply;
 123     static Ip::Address F;
 124
 125     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 126     memset(&preply, '\0', sizeof(pingerReplyData));
 127     n = comm_udp_recv(icmp_sock,
 128                       (char *) &preply,
 129                       sizeof(pingerReplyData),
 130                       0);
 131
 132     if (n < 0 && EAGAIN != errno) {
 133         debugs(37, DBG_IMPORTANT, HERE << "recv: " << xstrerror());
 134
 135         if (errno == ECONNREFUSED)
 136             Close();
 137
 138         if (errno == ECONNRESET)
 139             Close();
 140
 141         if (++fail_count == 10)
 142             Close();
 143
 144         return;
 145     }
 146
 147     fail_count = 0;
 148
 149     /** If its a test probe from the pinger. Do nothing. */
 150     if (n == 0) {
 151         return;
 152     }
 153
 154     F = preply.from;
 155
 156     F.port(0);
 157
 158     switch (preply.opcode) {
 159
 160     case S_ICMP_ECHO:
 161         debugs(37,4, HERE << " ICMP_ECHO of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 162         break;
 163
 164     case S_ICMP_DOM:
 165         debugs(37,4, HERE << " DomainPing of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 166         netdbHandlePingReply(F, preply.hops, preply.rtt);
 167         break;
 168
 169     default:
 170         debugs(37, DBG_IMPORTANT, HERE << "Bad opcode: " << preply.opcode << " from " << F);
 171         break;
 172     }
 173 }
 174
 175 #endif /* USE_ICMP */
 176
 177 void
 178 IcmpSquid::DomainPing(Ip::Address &to, const char *domain)
 179 {
 180 #if USE_ICMP
 181     debugs(37, 4, HERE << "'" << domain << "' (" << to << ")");
 182     SendEcho(to, S_ICMP_DOM, domain, 0);
 183 #endif
 184 }
 185
 186 int
 187 IcmpSquid::Open(void)
 188 {
 189 #if USE_ICMP
 190     const char *args[2];
 191     int rfd;
 192     int wfd;
 193     Ip::Address localhost;
 194
 195     /* User configured disabled. */
 196     if (!Config.pinger.enable) {
 197         Close();
 198         return -1;
 199     }
 200
 201     args[0] = "(pinger)";
 202     args[1] = NULL;
 203     localhost.setLocalhost();
 204
 205     /*
 206      * Do NOT use IPC_DGRAM (=IPC_UNIX_DGRAM) here because you can't
 207      * send() more than 4096 bytes on a socketpair() socket (at
 208      * least on FreeBSD).
 209      */
 210     pid = ipcCreate(IPC_UDP_SOCKET,
 211                     Config.pinger.program,
 212                     args,
 213                     "Pinger Socket",
 214                     localhost,
 215                     &rfd,
 216                     &wfd,
 217                     &hIpc);
 218
 219     if (pid < 0)
 220         return -1;
 221
 222     assert(rfd == wfd);
 223
 224     icmp_sock = rfd;
 225
 226     fd_note(icmp_sock, "pinger");
 227
 228     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 229
 230     commUnsetFdTimeout(icmp_sock);
 231
 232     debugs(37, DBG_IMPORTANT, HERE << "Pinger socket opened on FD " << icmp_sock);
 233
 234     /* Tests the pinger immediately using localhost */
 235     if (Ip::EnableIpv6)
 236         SendEcho(localhost, S_ICMP_ECHO, "ip6-localhost");
 237     if (localhost.setIPv4())
 238         SendEcho(localhost, S_ICMP_ECHO, "localhost");
 239
 240 #if _SQUID_WINDOWS_
 241
 242     debugs(37, 4, HERE << "Pinger handle: 0x" << std::hex << hIpc << std::dec << ", PID: " << pid);
 243
 244 #endif /* _SQUID_WINDOWS_ */
 245     return icmp_sock;
 246 #else /* USE_ICMP */
 247     return -1;
 248 #endif /* USE_ICMP */
 249 }
 250
 251 void
 252 IcmpSquid::Close(void)
 253 {
 254 #if USE_ICMP
 255
 256     if (icmp_sock < 0)
 257         return;
 258
 259     debugs(37, DBG_IMPORTANT, HERE << "Closing Pinger socket on FD " << icmp_sock);
 260
 261 #if _SQUID_WINDOWS_
 262
 263     send(icmp_sock, (const void *) "$shutdown\n", 10, 0);
 264
 265 #endif
 266
 267     comm_close(icmp_sock);
 268
 269 #if _SQUID_WINDOWS_
 270
 271     if (hIpc) {
 272         if (WaitForSingleObject(hIpc, 12000) != WAIT_OBJECT_0) {
 273             getCurrentTime();
 274             debugs(37, DBG_CRITICAL, HERE << "WARNING: (pinger," << pid << ") didn't exit in 12 seconds");
 275         }
 276
 277         CloseHandle(hIpc);
 278     }
 279
 280 #endif
 281     icmp_sock = -1;
 282
 283 #endif
 284 }