src/icmp/Icmp6.cc

   1 /*
   2  * Copyright (C) 1996-2020 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         int xerrno = errno;
 105         debugs(50, DBG_CRITICAL, MYNAME << " icmp_sock: " << xstrerr(xerrno));
 106         return -1;
 107     }
 108
 109     icmp_ident = getpid() & 0xffff;
 110     debugs(42, DBG_IMPORTANT, "pinger: ICMPv6 socket opened");
 111
 112     return icmp_sock;
 113 }
 114
 115 /**
 116  * Generates an RFC 4443 Icmp6 ECHO Packet and sends into the network.
 117  */
 118 void
 119 Icmp6::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
 120 {
 121     int x;
 122     LOCAL_ARRAY(char, pkt, MAX_PKT6_SZ);
 123     struct icmp6_hdr *icmp = NULL;
 124     icmpEchoData *echo = NULL;
 125     struct addrinfo *S = NULL;
 126     size_t icmp6_pktsize = 0;
 127
 128     memset(pkt, '\0', MAX_PKT6_SZ);
 129     icmp = (struct icmp6_hdr *)pkt;
 130
 131     /*
 132      * cevans - beware signed/unsigned issues in untrusted data from
 133      * the network!!
 134      */
 135     if (len < 0) {
 136         len = 0;
 137     }
 138
 139     // Construct Icmp6 ECHO header
 140     icmp->icmp6_type = ICMP6_ECHO_REQUEST;
 141     icmp->icmp6_code = 0;
 142     icmp->icmp6_cksum = 0;
 143     icmp->icmp6_id = icmp_ident;
 144     icmp->icmp6_seq = (unsigned short) icmp_pkts_sent;
 145     ++icmp_pkts_sent;
 146
 147     icmp6_pktsize = sizeof(struct icmp6_hdr);
 148
 149     // Fill Icmp6 ECHO data content
 150     echo = (icmpEchoData *) (pkt + sizeof(icmp6_hdr));
 151     echo->opcode = (unsigned char) opcode;
 152     memcpy(&echo->tv, &current_time, sizeof(struct timeval));
 153
 154     icmp6_pktsize += sizeof(struct timeval) + sizeof(char);
 155
 156     if (payload) {
 157         if (len > MAX_PAYLOAD)
 158             len = MAX_PAYLOAD;
 159
 160         memcpy(echo->payload, payload, len);
 161
 162         icmp6_pktsize += len;
 163     }
 164
 165     icmp->icmp6_cksum = CheckSum((unsigned short *) icmp, icmp6_pktsize);
 166
 167     to.getAddrInfo(S);
 168     ((sockaddr_in6*)S->ai_addr)->sin6_port = 0;
 169
 170     assert(icmp6_pktsize <= MAX_PKT6_SZ);
 171
 172     debugs(42, 5, HERE << "Send Icmp6 packet to " << to << ".");
 173
 174     x = sendto(icmp_sock,
 175                (const void *) pkt,
 176                icmp6_pktsize,
 177                0,
 178                S->ai_addr,
 179                S->ai_addrlen);
 180
 181     if (x < 0) {
 182         int xerrno = errno;
 183         debugs(42, DBG_IMPORTANT, MYNAME << "ERROR: sending to ICMPv6 packet to " << to << ": " << xstrerr(xerrno));
 184     }
 185     debugs(42,9, HERE << "x=" << x);
 186
 187     Log(to, 0, NULL, 0, 0);
 188     Ip::Address::FreeAddr(S);
 189 }
 190
 191 /**
 192  * Reads an RFC 4443 Icmp6 ECHO-REPLY Packet from the network.
 193  */
 194 void
 195 Icmp6::Recv(void)
 196 {
 197     int n;
 198     struct addrinfo *from = NULL;
 199 //    struct ip6_hdr *ip = NULL;
 200     static char *pkt = NULL;
 201     struct icmp6_hdr *icmp6header = NULL;
 202     icmpEchoData *echo = NULL;
 203     struct timeval now;
 204     static pingerReplyData preply;
 205
 206     if (icmp_sock < 0) {
 207         debugs(42, DBG_CRITICAL, HERE << "dropping ICMPv6 read. No socket!?");
 208         return;
 209     }
 210
 211     if (pkt == NULL) {
 212         pkt = (char *)xmalloc(MAX_PKT6_SZ);
 213     }
 214
 215     Ip::Address::InitAddr(from);
 216
 217     n = recvfrom(icmp_sock,
 218                  (void *)pkt,
 219                  MAX_PKT6_SZ,
 220                  0,
 221                  from->ai_addr,
 222                  &from->ai_addrlen);
 223
 224     if (n <= 0) {
 225         debugs(42, DBG_CRITICAL, HERE << "Error when calling recvfrom() on ICMPv6 socket.");
 226         Ip::Address::FreeAddr(from);
 227         return;
 228     }
 229
 230     preply.from = *from;
 231
 232 #if GETTIMEOFDAY_NO_TZP
 233
 234     gettimeofday(&now);
 235
 236 #else
 237
 238     gettimeofday(&now, NULL);
 239
 240 #endif
 241
 242     debugs(42, 8, HERE << n << " bytes from " << preply.from);
 243
 244 // FIXME INET6 : The IPv6 Header (ip6_hdr) is not availble directly >:-(
 245 //
 246 // TTL still has to come from the IP header somewhere.
 247 //  still need to strip and process it properly.
 248 //  probably have to rely on RTT as given by timestamp in data sent and current.
 249     /* IPv6 Header Structures (linux)
 250     struct ip6_hdr
 251
 252     // fields (via simple define)
 253     #define ip6_vfc     // N.A
 254     #define ip6_flow    // N/A
 255     #define ip6_plen    // payload length.
 256     #define ip6_nxt     // expect to be type 0x3a - ICMPv6
 257     #define ip6_hlim    // MAX hops  (always 64, but no guarantee)
 258     #define ip6_hops    // HOPS!!!  (can it be true??)
 259
 260         ip = (struct ip6_hdr *) pkt;
 261         FIXME  += sizeof(ip6_hdr);
 262
 263     debugs(42, DBG_CRITICAL, HERE << "ip6_nxt=" << ip->ip6_nxt <<
 264             ", ip6_plen=" << ip->ip6_plen <<
 265             ", ip6_hlim=" << ip->ip6_hlim <<
 266             ", ip6_hops=" << ip->ip6_hops   <<
 267             " ::: 40 == sizef(ip6_hdr) == " << sizeof(ip6_hdr)
 268     );
 269     */
 270
 271     icmp6header = (struct icmp6_hdr *) pkt;
 272
 273     if (icmp6header->icmp6_type != ICMP6_ECHO_REPLY) {
 274
 275         switch (icmp6header->icmp6_type) {
 276         case 134:
 277         case 135:
 278         case 136:
 279             /* ignore Router/Neighbour Advertisements */
 280             break;
 281
 282         default:
 283             debugs(42, 8, HERE << preply.from << " said: " << icmp6header->icmp6_type << "/" << (int)icmp6header->icmp6_code << " " <<
 284                    IcmpPacketType(icmp6header->icmp6_type));
 285         }
 286         Ip::Address::FreeAddr(from);
 287         return;
 288     }
 289
 290     if (icmp6header->icmp6_id != icmp_ident) {
 291         debugs(42, 8, HERE << "dropping Icmp6 read. IDENT check failed. ident=='" << icmp_ident << "'=='" << icmp6header->icmp6_id << "'");
 292         Ip::Address::FreeAddr(from);
 293         return;
 294     }
 295
 296     echo = (icmpEchoData *) (pkt + sizeof(icmp6_hdr));
 297
 298     preply.opcode = echo->opcode;
 299
 300     struct timeval tv;
 301     memcpy(&tv, &echo->tv, sizeof(struct timeval));
 302     preply.rtt = tvSubMsec(tv, now);
 303
 304     /*
 305      * FIXME INET6: Without access to the IPv6-Hops header we must rely on the total RTT
 306      *      and could caculate the hops from that, but it produces some weird value mappings using ipHops
 307      *  for now everything is 1 v6 hop away with variant RTT
 308      * WANT:    preply.hops = ip->ip6_hops; // ipHops(ip->ip_hops);
 309      */
 310     preply.hops = 1;
 311
 312     preply.psize = n - /* sizeof(ip6_hdr) - */ sizeof(icmp6_hdr) - (sizeof(icmpEchoData) - MAX_PKT6_SZ);
 313
 314     /* Ensure the response packet has safe payload size */
 315     if ( preply.psize > (unsigned short) MAX_PKT6_SZ) {
 316         preply.psize = MAX_PKT6_SZ;
 317     } else if ( preply.psize < (unsigned short)0) {
 318         preply.psize = 0;
 319     }
 320
 321     Log(preply.from,
 322         icmp6header->icmp6_type,
 323         IcmpPacketType(icmp6header->icmp6_type),
 324         preply.rtt,
 325         preply.hops);
 326
 327     /* send results of the lookup back to squid.*/
 328     control.SendResult(preply, (sizeof(pingerReplyData) - PINGER_PAYLOAD_SZ + preply.psize) );
 329     Ip::Address::FreeAddr(from);
 330 }
 331
 332 #endif /* USE_ICMP */
 333