src/icmp/Icmp6.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 42    ICMP Pinger program */
  10
  11 //#define SQUID_HELPER 1
  12
  13 #include "squid.h"
  14
  15 #if USE_ICMP
  16
  17 #include "Debug.h"
  18 #include "Icmp6.h"
  19 #include "IcmpPinger.h"
  20 #include "leakcheck.h"
  21 #include "SquidTime.h"
  22
  23 // Some system headers are only neeed internally here.
  24 // They should not be included via the header.
  25
  26 #if HAVE_NETINET_IP6_H
  27 #include <netinet/ip6.h>
  28 #endif
  29
  30 // Icmp6 OP-Codes
  31 // see http://www.iana.org/assignments/icmpv6-parameters
  32 static const char *
  33 IcmpPacketType(uint8_t v)
  34 {
  35     // NP: LowPktStr is for codes 0-127
  36     static const char *icmp6LowPktStr[] = {
  37         "ICMPv6 0",         // 0
  38         "Destination Unreachable",  // 1 - RFC2463
  39         "Packet Too Big",       // 2 - RFC2463
  40         "Time Exceeded",        // 3 - RFC2463
  41         "Parameter Problem",        // 4 - RFC2463
  42     };
  43
  44     // low codes 1-4 registered
  45     if (0 < v && v < 5)
  46         return icmp6LowPktStr[(int)(v&0x7f)];
  47
  48     // NP: HighPktStr is for codes 128-255
  49     static const char *icmp6HighPktStr[] = {
  50         "Echo Request",                 // 128 - RFC2463
  51         "Echo Reply",                   // 129 - RFC2463
  52         "Multicast Listener Query",         // 130 - RFC2710
  53         "Multicast Listener Report",            // 131 - RFC2710
  54         "Multicast Listener Done",          // 132 - RFC2710
  55         "Router Solicitation",              // 133 - RFC4861
  56         "Router Advertisement",             // 134 - RFC4861
  57         "Neighbor Solicitation",            // 135 - RFC4861
  58         "Neighbor Advertisement",           // 136 - RFC4861
  59         "Redirect Message",             // 137 - RFC4861
  60         "Router Renumbering",               // 138 - Crawford
  61         "ICMP Node Information Query",          // 139 - RFC4620
  62         "ICMP Node Information Response",       // 140 - RFC4620
  63         "Inverse Neighbor Discovery Solicitation",  // 141 - RFC3122
  64         "Inverse Neighbor Discovery Advertisement", // 142 - RFC3122
  65         "Version 2 Multicast Listener Report",      // 143 - RFC3810
  66         "Home Agent Address Discovery Request",     // 144 - RFC3775
  67         "Home Agent Address Discovery Reply",       // 145 - RFC3775
  68         "Mobile Prefix Solicitation",           // 146 - RFC3775
  69         "Mobile Prefix Advertisement",          // 147 - RFC3775
  70         "Certification Path Solicitation",      // 148 - RFC3971
  71         "Certification Path Advertisement",     // 149 - RFC3971
  72         "ICMP Experimental (150)",          // 150 - RFC4065
  73         "Multicast Router Advertisement",       // 151 - RFC4286
  74         "Multicast Router Solicitation",        // 152 - RFC4286
  75         "Multicast Router Termination",         // 153 - [RFC4286]
  76     };
  77
  78     // high codes 127-153 registered
  79     if (127 < v && v < 154)
  80         return icmp6HighPktStr[(int)(v&0x7f)];
  81
  82     // give all others a generic display
  83     static char buf[50];
  84     snprintf(buf, sizeof(buf), "ICMPv6 %u", v);
  85     return buf;
  86 }
  87
  88 Icmp6::Icmp6() : Icmp()
  89 {
  90     ; // nothing new.
  91 }
  92
  93 Icmp6::~Icmp6()
  94 {
  95     Close();
  96 }
  97
  98 int
  99 Icmp6::Open(void)
 100 {
 101     icmp_sock = socket(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
 102
 103     if (icmp_sock < 0) {
 104         debugs(50, DBG_CRITICAL, HERE << " icmp_sock: " << xstrerror());
 105         return -1;
 106     }
 107
 108     icmp_ident = getpid() & 0xffff;
 109     debugs(42, DBG_IMPORTANT, "pinger: ICMPv6 socket opened");
 110
 111     return icmp_sock;
 112 }
 113
 114 /**
 115  * Generates an RFC 4443 Icmp6 ECHO Packet and sends into the network.
 116  */
 117 void
 118 Icmp6::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
 119 {
 120     int x;
 121     LOCAL_ARRAY(char, pkt, MAX_PKT6_SZ);
 122     struct icmp6_hdr *icmp = NULL;
 123     icmpEchoData *echo = NULL;
 124     struct addrinfo *S = NULL;
 125     size_t icmp6_pktsize = 0;
 126
 127     memset(pkt, '\0', MAX_PKT6_SZ);
 128     icmp = (struct icmp6_hdr *)pkt;
 129
 130     /*
 131      * cevans - beware signed/unsigned issues in untrusted data from
 132      * the network!!
 133      */
 134     if (len < 0) {
 135         len = 0;
 136     }
 137
 138     // Construct Icmp6 ECHO header
 139     icmp->icmp6_type = ICMP6_ECHO_REQUEST;
 140     icmp->icmp6_code = 0;
 141     icmp->icmp6_cksum = 0;
 142     icmp->icmp6_id = icmp_ident;
 143     icmp->icmp6_seq = (unsigned short) icmp_pkts_sent;
 144     ++icmp_pkts_sent;
 145
 146     icmp6_pktsize = sizeof(struct icmp6_hdr);
 147
 148     // Fill Icmp6 ECHO data content
 149     echo = (icmpEchoData *) (pkt + sizeof(icmp6_hdr));
 150     echo->opcode = (unsigned char) opcode;
 151     memcpy(&echo->tv, &current_time, sizeof(struct timeval));
 152
 153     icmp6_pktsize += sizeof(struct timeval) + sizeof(char);
 154
 155     if (payload) {
 156         if (len > MAX_PAYLOAD)
 157             len = MAX_PAYLOAD;
 158
 159         memcpy(echo->payload, payload, len);
 160
 161         icmp6_pktsize += len;
 162     }
 163
 164     icmp->icmp6_cksum = CheckSum((unsigned short *) icmp, icmp6_pktsize);
 165
 166     to.getAddrInfo(S);
 167     ((sockaddr_in6*)S->ai_addr)->sin6_port = 0;
 168
 169     assert(icmp6_pktsize <= MAX_PKT6_SZ);
 170
 171     debugs(42, 5, HERE << "Send Icmp6 packet to " << to << ".");
 172
 173     x = sendto(icmp_sock,
 174                (const void *) pkt,
 175                icmp6_pktsize,
 176                0,
 177                S->ai_addr,
 178                S->ai_addrlen);
 179
 180     if (x < 0) {
 181         debugs(42, DBG_IMPORTANT, HERE << "Error sending to ICMPv6 packet to " << to << ". ERR: " << xstrerror());
 182     }
 183     debugs(42,9, HERE << "x=" << x);
 184
 185     Log(to, 0, NULL, 0, 0);
 186     Ip::Address::FreeAddr(S);
 187 }
 188
 189 /**
 190  * Reads an RFC 4443 Icmp6 ECHO-REPLY Packet from the network.
 191  */
 192 void
 193 Icmp6::Recv(void)
 194 {
 195     int n;
 196     struct addrinfo *from = NULL;
 197 //    struct ip6_hdr *ip = NULL;
 198     static char *pkt = NULL;
 199     struct icmp6_hdr *icmp6header = NULL;
 200     icmpEchoData *echo = NULL;
 201     struct timeval now;
 202     static pingerReplyData preply;
 203
 204     if (icmp_sock < 0) {
 205         debugs(42, DBG_CRITICAL, HERE << "dropping ICMPv6 read. No socket!?");
 206         return;
 207     }
 208
 209     if (pkt == NULL) {
 210         pkt = (char *)xmalloc(MAX_PKT6_SZ);
 211     }
 212
 213     Ip::Address::InitAddr(from);
 214
 215     n = recvfrom(icmp_sock,
 216                  (void *)pkt,
 217                  MAX_PKT6_SZ,
 218                  0,
 219                  from->ai_addr,
 220                  &from->ai_addrlen);
 221
 222     if (n <= 0) {
 223         debugs(42, DBG_CRITICAL, HERE << "Error when calling recvfrom() on ICMPv6 socket.");
 224         Ip::Address::FreeAddr(from);
 225         return;
 226     }
 227
 228     preply.from = *from;
 229
 230 #if GETTIMEOFDAY_NO_TZP
 231
 232     gettimeofday(&now);
 233
 234 #else
 235
 236     gettimeofday(&now, NULL);
 237
 238 #endif
 239
 240     debugs(42, 8, HERE << n << " bytes from " << preply.from);
 241
 242 // FIXME INET6 : The IPv6 Header (ip6_hdr) is not availble directly >:-(
 243 //
 244 // TTL still has to come from the IP header somewhere.
 245 //  still need to strip and process it properly.
 246 //  probably have to rely on RTT as given by timestamp in data sent and current.
 247     /* IPv6 Header Structures (linux)
 248     struct ip6_hdr
 249
 250     // fields (via simple define)
 251     #define ip6_vfc     // N.A
 252     #define ip6_flow    // N/A
 253     #define ip6_plen    // payload length.
 254     #define ip6_nxt     // expect to be type 0x3a - ICMPv6
 255     #define ip6_hlim    // MAX hops  (always 64, but no guarantee)
 256     #define ip6_hops    // HOPS!!!  (can it be true??)
 257
 258         ip = (struct ip6_hdr *) pkt;
 259         pkt += sizeof(ip6_hdr);
 260
 261     debugs(42, DBG_CRITICAL, HERE << "ip6_nxt=" << ip->ip6_nxt <<
 262             ", ip6_plen=" << ip->ip6_plen <<
 263             ", ip6_hlim=" << ip->ip6_hlim <<
 264             ", ip6_hops=" << ip->ip6_hops   <<
 265             " ::: 40 == sizef(ip6_hdr) == " << sizeof(ip6_hdr)
 266     );
 267     */
 268
 269     icmp6header = (struct icmp6_hdr *) pkt;
 270     pkt += sizeof(icmp6_hdr);
 271
 272     if (icmp6header->icmp6_type != ICMP6_ECHO_REPLY) {
 273
 274         switch (icmp6header->icmp6_type) {
 275         case 134:
 276         case 135:
 277         case 136:
 278             /* ignore Router/Neighbour Advertisements */
 279             break;
 280
 281         default:
 282             debugs(42, 8, HERE << preply.from << " said: " << icmp6header->icmp6_type << "/" << (int)icmp6header->icmp6_code << " " <<
 283                    IcmpPacketType(icmp6header->icmp6_type));
 284         }
 285         Ip::Address::FreeAddr(from);
 286         return;
 287     }
 288
 289     if (icmp6header->icmp6_id != icmp_ident) {
 290         debugs(42, 8, HERE << "dropping Icmp6 read. IDENT check failed. ident=='" << icmp_ident << "'=='" << icmp6header->icmp6_id << "'");
 291         Ip::Address::FreeAddr(from);
 292         return;
 293     }
 294
 295     echo = (icmpEchoData *) pkt;
 296
 297     preply.opcode = echo->opcode;
 298
 299     struct timeval tv;
 300     memcpy(&tv, &echo->tv, sizeof(struct timeval));
 301     preply.rtt = tvSubMsec(tv, now);
 302
 303     /*
 304      * FIXME INET6: Without access to the IPv6-Hops header we must rely on the total RTT
 305      *      and could caculate the hops from that, but it produces some weird value mappings using ipHops
 306      *  for now everything is 1 v6 hop away with variant RTT
 307      * WANT:    preply.hops = ip->ip6_hops; // ipHops(ip->ip_hops);
 308      */
 309     preply.hops = 1;
 310
 311     preply.psize = n - /* sizeof(ip6_hdr) - */ sizeof(icmp6_hdr) - (sizeof(icmpEchoData) - MAX_PKT6_SZ);
 312
 313     /* Ensure the response packet has safe payload size */
 314     if ( preply.psize > (unsigned short) MAX_PKT6_SZ) {
 315         preply.psize = MAX_PKT6_SZ;
 316     } else if ( preply.psize < (unsigned short)0) {
 317         preply.psize = 0;
 318     }
 319
 320     Log(preply.from,
 321         icmp6header->icmp6_type,
 322         IcmpPacketType(icmp6header->icmp6_type),
 323         preply.rtt,
 324         preply.hops);
 325
 326     /* send results of the lookup back to squid.*/
 327     control.SendResult(preply, (sizeof(pingerReplyData) - PINGER_PAYLOAD_SZ + preply.psize) );
 328     Ip::Address::FreeAddr(from);
 329 }
 330
 331 #endif /* USE_ICMP */
 332