src/icmp/IcmpSquid.cc

   1 /*
   2  * Copyright (C) 1996-2017 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         int xerrno = errno;
  97         debugs(37, DBG_IMPORTANT, MYNAME << "send: " << xstrerr(xerrno));
  98
  99         /** \li  If the send results in ECONNREFUSED or EPIPE errors from helper, will cleanly shutdown the module. */
 100         /** \todo This should try restarting the helper a few times?? before giving up? */
 101         if (xerrno == ECONNREFUSED || xerrno == EPIPE) {
 102             Close();
 103             return;
 104         }
 105         /** All other send errors are ignored. */
 106     } else if (x != slen) {
 107         debugs(37, DBG_IMPORTANT, HERE << "Wrote " << x << " of " << slen << " bytes");
 108     }
 109 }
 110
 111 // static Callback to wrap the squid-side ICMP handler.
 112 // the IcmpSquid::Recv cannot be declared both static and virtual.
 113 static void
 114 icmpSquidRecv(int unused1, void *unused2)
 115 {
 116     icmpEngine.Recv();
 117 }
 118
 119 void
 120 IcmpSquid::Recv()
 121 {
 122     int n;
 123     static int fail_count = 0;
 124     pingerReplyData preply;
 125     static Ip::Address F;
 126
 127     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 128     memset(&preply, '\0', sizeof(pingerReplyData));
 129     n = comm_udp_recv(icmp_sock,
 130                       (char *) &preply,
 131                       sizeof(pingerReplyData),
 132                       0);
 133
 134     if (n < 0 && EAGAIN != errno) {
 135         int xerrno = errno;
 136         debugs(37, DBG_IMPORTANT, MYNAME << "recv: " << xstrerr(xerrno));
 137
 138         if (xerrno == ECONNREFUSED)
 139             Close();
 140
 141         if (xerrno == ECONNRESET)
 142             Close();
 143
 144         if (++fail_count == 10)
 145             Close();
 146
 147         return;
 148     }
 149
 150     fail_count = 0;
 151
 152     /** If its a test probe from the pinger. Do nothing. */
 153     if (n == 0) {
 154         return;
 155     }
 156
 157     F = preply.from;
 158
 159     F.port(0);
 160
 161     switch (preply.opcode) {
 162
 163     case S_ICMP_ECHO:
 164         debugs(37,4, HERE << " ICMP_ECHO of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 165         break;
 166
 167     case S_ICMP_DOM:
 168         debugs(37,4, HERE << " DomainPing of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 169         netdbHandlePingReply(F, preply.hops, preply.rtt);
 170         break;
 171
 172     default:
 173         debugs(37, DBG_IMPORTANT, HERE << "Bad opcode: " << preply.opcode << " from " << F);
 174         break;
 175     }
 176 }
 177
 178 #endif /* USE_ICMP */
 179
 180 void
 181 IcmpSquid::DomainPing(Ip::Address &to, const char *domain)
 182 {
 183 #if USE_ICMP
 184     debugs(37, 4, HERE << "'" << domain << "' (" << to << ")");
 185     SendEcho(to, S_ICMP_DOM, domain, 0);
 186 #endif
 187 }
 188
 189 int
 190 IcmpSquid::Open(void)
 191 {
 192 #if USE_ICMP
 193     const char *args[2];
 194     int rfd;
 195     int wfd;
 196     Ip::Address localhost;
 197
 198     /* User configured disabled. */
 199     if (!IcmpCfg.enable) {
 200         Close();
 201         return -1;
 202     }
 203
 204     args[0] = "(pinger)";
 205     args[1] = NULL;
 206     localhost.setLocalhost();
 207
 208     /*
 209      * Do NOT use IPC_DGRAM (=IPC_UNIX_DGRAM) here because you can't
 210      * send() more than 4096 bytes on a socketpair() socket (at
 211      * least on FreeBSD).
 212      */
 213     pid = ipcCreate(IPC_UDP_SOCKET,
 214                     IcmpCfg.program.c_str(),
 215                     args,
 216                     "Pinger Socket",
 217                     localhost,
 218                     &rfd,
 219                     &wfd,
 220                     &hIpc);
 221
 222     if (pid < 0)
 223         return -1;
 224
 225     assert(rfd == wfd);
 226
 227     icmp_sock = rfd;
 228
 229     fd_note(icmp_sock, "pinger");
 230
 231     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 232
 233     commUnsetFdTimeout(icmp_sock);
 234
 235     debugs(37, DBG_IMPORTANT, HERE << "Pinger socket opened on FD " << icmp_sock);
 236
 237     /* Tests the pinger immediately using localhost */
 238     if (Ip::EnableIpv6)
 239         SendEcho(localhost, S_ICMP_ECHO, "ip6-localhost");
 240     if (localhost.setIPv4())
 241         SendEcho(localhost, S_ICMP_ECHO, "localhost");
 242
 243 #if _SQUID_WINDOWS_
 244
 245     debugs(37, 4, HERE << "Pinger handle: 0x" << std::hex << hIpc << std::dec << ", PID: " << pid);
 246
 247 #endif /* _SQUID_WINDOWS_ */
 248     return icmp_sock;
 249 #else /* USE_ICMP */
 250     return -1;
 251 #endif /* USE_ICMP */
 252 }
 253
 254 void
 255 IcmpSquid::Close(void)
 256 {
 257 #if USE_ICMP
 258
 259     if (icmp_sock < 0)
 260         return;
 261
 262     debugs(37, DBG_IMPORTANT, HERE << "Closing Pinger socket on FD " << icmp_sock);
 263
 264 #if _SQUID_WINDOWS_
 265
 266     send(icmp_sock, (const void *) "$shutdown\n", 10, 0);
 267
 268 #endif
 269
 270     comm_close(icmp_sock);
 271
 272 #if _SQUID_WINDOWS_
 273
 274     if (hIpc) {
 275         if (WaitForSingleObject(hIpc, 12000) != WAIT_OBJECT_0) {
 276             getCurrentTime();
 277             debugs(37, DBG_CRITICAL, HERE << "WARNING: (pinger," << pid << ") didn't exit in 12 seconds");
 278         }
 279
 280         CloseHandle(hIpc);
 281     }
 282
 283 #endif
 284     icmp_sock = -1;
 285
 286 #endif
 287 }
 288