src/icmp/IcmpSquid.cc

   1 /*
   2  * Copyright (C) 1996-2015 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/IcmpConfig.h"
  17 #include "icmp/IcmpSquid.h"
  18 #include "icmp/net_db.h"
  19 #include "ip/tools.h"
  20 #include "SquidConfig.h"
  21 #include "SquidIpc.h"
  22 #include "SquidTime.h"
  23
  24 #include <cerrno>
  25
  26 // Instance global to be available in main() and elsewhere.
  27 IcmpSquid icmpEngine;
  28
  29 #if USE_ICMP
  30
  31 #define S_ICMP_ECHO     1
  32 #define S_ICMP_DOM      3
  33
  34 static void * hIpc;
  35 static pid_t pid;
  36
  37 #endif /* USE_ICMP */
  38
  39 IcmpSquid::IcmpSquid() : Icmp()
  40 {
  41     ; // nothing new.
  42 }
  43
  44 IcmpSquid::~IcmpSquid()
  45 {
  46     Close();
  47 }
  48
  49 #if USE_ICMP
  50
  51 void
  52 IcmpSquid::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  53 {
  54     static pingerEchoData pecho;
  55     int x, slen;
  56
  57     /** \li Does nothing if the pinger socket is not available. */
  58     if (icmp_sock < 0) {
  59         debugs(37, 2, HERE << " Socket Closed. Aborted send to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  60         return;
  61     }
  62
  63     /** \li  If no payload is given or is set as NULL it will ignore payload and len */
  64     if (!payload)
  65         len = 0;
  66
  67     /** \li Otherwise if len is 0, uses strlen() to detect length of payload.
  68      \bug This will result in part of the payload being truncated if it contains a NULL character.
  69      \bug Or it may result in a buffer over-run if the payload is not nul-terminated properly.
  70      */
  71     else if (payload && len == 0)
  72         len = strlen(payload);
  73
  74     /** \li
  75      \bug If length specified or auto-detected is greater than the possible payload squid will die with an assert.
  76      \todo This should perhapse be reduced to a truncated payload? or no payload. A WARNING is due anyway.
  77      */
  78     assert(len <= PINGER_PAYLOAD_SZ);
  79
  80     pecho.to = to;
  81
  82     pecho.opcode = (unsigned char) opcode;
  83
  84     pecho.psize = len;
  85
  86     if (len > 0)
  87         memcpy(pecho.payload, payload, len);
  88
  89     slen = sizeof(pingerEchoData) - PINGER_PAYLOAD_SZ + pecho.psize;
  90
  91     debugs(37, 2, HERE << "to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  92
  93     x = comm_udp_send(icmp_sock, (char *)&pecho, slen, 0);
  94
  95     if (x < 0) {
  96         debugs(37, DBG_IMPORTANT, HERE << "send: " << xstrerror());
  97
  98         /** \li  If the send results in ECONNREFUSED or EPIPE errors from helper, will cleanly shutdown the module. */
  99         /** \todo This should try restarting the helper a few times?? before giving up? */
 100         if (errno == ECONNREFUSED || errno == EPIPE) {
 101             Close();
 102             return;
 103         }
 104         /** All other send errors are ignored. */
 105     } else if (x != slen) {
 106         debugs(37, DBG_IMPORTANT, HERE << "Wrote " << x << " of " << slen << " bytes");
 107     }
 108 }
 109
 110 // static Callback to wrap the squid-side ICMP handler.
 111 // the IcmpSquid::Recv cannot be declared both static and virtual.
 112 static void
 113 icmpSquidRecv(int unused1, void *unused2)
 114 {
 115     icmpEngine.Recv();
 116 }
 117
 118 void
 119 IcmpSquid::Recv()
 120 {
 121     int n;
 122     static int fail_count = 0;
 123     pingerReplyData preply;
 124     static Ip::Address F;
 125
 126     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 127     memset(&preply, '\0', sizeof(pingerReplyData));
 128     n = comm_udp_recv(icmp_sock,
 129                       (char *) &preply,
 130                       sizeof(pingerReplyData),
 131                       0);
 132
 133     if (n < 0 && EAGAIN != errno) {
 134         debugs(37, DBG_IMPORTANT, HERE << "recv: " << xstrerror());
 135
 136         if (errno == ECONNREFUSED)
 137             Close();
 138
 139         if (errno == ECONNRESET)
 140             Close();
 141
 142         if (++fail_count == 10)
 143             Close();
 144
 145         return;
 146     }
 147
 148     fail_count = 0;
 149
 150     /** If its a test probe from the pinger. Do nothing. */
 151     if (n == 0) {
 152         return;
 153     }
 154
 155     F = preply.from;
 156
 157     F.port(0);
 158
 159     switch (preply.opcode) {
 160
 161     case S_ICMP_ECHO:
 162         debugs(37,4, HERE << " ICMP_ECHO of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 163         break;
 164
 165     case S_ICMP_DOM:
 166         debugs(37,4, HERE << " DomainPing of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 167         netdbHandlePingReply(F, preply.hops, preply.rtt);
 168         break;
 169
 170     default:
 171         debugs(37, DBG_IMPORTANT, HERE << "Bad opcode: " << preply.opcode << " from " << F);
 172         break;
 173     }
 174 }
 175
 176 #endif /* USE_ICMP */
 177
 178 void
 179 IcmpSquid::DomainPing(Ip::Address &to, const char *domain)
 180 {
 181 #if USE_ICMP
 182     debugs(37, 4, HERE << "'" << domain << "' (" << to << ")");
 183     SendEcho(to, S_ICMP_DOM, domain, 0);
 184 #endif
 185 }
 186
 187 int
 188 IcmpSquid::Open(void)
 189 {
 190 #if USE_ICMP
 191     const char *args[2];
 192     int rfd;
 193     int wfd;
 194     Ip::Address localhost;
 195
 196     /* User configured disabled. */
 197     if (!IcmpCfg.enable) {
 198         Close();
 199         return -1;
 200     }
 201
 202     args[0] = "(pinger)";
 203     args[1] = NULL;
 204     localhost.setLocalhost();
 205
 206     /*
 207      * Do NOT use IPC_DGRAM (=IPC_UNIX_DGRAM) here because you can't
 208      * send() more than 4096 bytes on a socketpair() socket (at
 209      * least on FreeBSD).
 210      */
 211     pid = ipcCreate(IPC_UDP_SOCKET,
 212                     IcmpCfg.program.c_str(),
 213                     args,
 214                     "Pinger Socket",
 215                     localhost,
 216                     &rfd,
 217                     &wfd,
 218                     &hIpc);
 219
 220     if (pid < 0)
 221         return -1;
 222
 223     assert(rfd == wfd);
 224
 225     icmp_sock = rfd;
 226
 227     fd_note(icmp_sock, "pinger");
 228
 229     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 230
 231     commUnsetFdTimeout(icmp_sock);
 232
 233     debugs(37, DBG_IMPORTANT, HERE << "Pinger socket opened on FD " << icmp_sock);
 234
 235     /* Tests the pinger immediately using localhost */
 236     if (Ip::EnableIpv6)
 237         SendEcho(localhost, S_ICMP_ECHO, "ip6-localhost");
 238     if (localhost.setIPv4())
 239         SendEcho(localhost, S_ICMP_ECHO, "localhost");
 240
 241 #if _SQUID_WINDOWS_
 242
 243     debugs(37, 4, HERE << "Pinger handle: 0x" << std::hex << hIpc << std::dec << ", PID: " << pid);
 244
 245 #endif /* _SQUID_WINDOWS_ */
 246     return icmp_sock;
 247 #else /* USE_ICMP */
 248     return -1;
 249 #endif /* USE_ICMP */
 250 }
 251
 252 void
 253 IcmpSquid::Close(void)
 254 {
 255 #if USE_ICMP
 256
 257     if (icmp_sock < 0)
 258         return;
 259
 260     debugs(37, DBG_IMPORTANT, HERE << "Closing Pinger socket on FD " << icmp_sock);
 261
 262 #if _SQUID_WINDOWS_
 263
 264     send(icmp_sock, (const void *) "$shutdown\n", 10, 0);
 265
 266 #endif
 267
 268     comm_close(icmp_sock);
 269
 270 #if _SQUID_WINDOWS_
 271
 272     if (hIpc) {
 273         if (WaitForSingleObject(hIpc, 12000) != WAIT_OBJECT_0) {
 274             getCurrentTime();
 275             debugs(37, DBG_CRITICAL, HERE << "WARNING: (pinger," << pid << ") didn't exit in 12 seconds");
 276         }
 277
 278         CloseHandle(hIpc);
 279     }
 280
 281 #endif
 282     icmp_sock = -1;
 283
 284 #endif
 285 }
 286