src/icmp/Icmp4.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 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 "Icmp4.h"
  19 #include "IcmpPinger.h"
  20 #include "leakcheck.h"
  21 #include "SquidTime.h"
  22
  23 static const char *
  24 IcmpPacketType(uint8_t v)
  25 {
  26     static const char *icmpPktStr[] = {
  27         "Echo Reply",
  28         "ICMP 1",
  29         "ICMP 2",
  30         "Destination Unreachable",
  31         "Source Quench",
  32         "Redirect",
  33         "ICMP 6",
  34         "ICMP 7",
  35         "Echo",
  36         "ICMP 9",
  37         "ICMP 10",
  38         "Time Exceeded",
  39         "Parameter Problem",
  40         "Timestamp",
  41         "Timestamp Reply",
  42         "Info Request",
  43         "Info Reply",
  44         "Out of Range Type"
  45     };
  46
  47     if (v > 17) {
  48         static char buf[50];
  49         snprintf(buf, sizeof(buf), "ICMP %u (invalid)", v);
  50         return buf;
  51     }
  52
  53     return icmpPktStr[v];
  54 }
  55
  56 Icmp4::Icmp4() : Icmp()
  57 {
  58     ;
  59 }
  60
  61 Icmp4::~Icmp4()
  62 {
  63     Close();
  64 }
  65
  66 int
  67 Icmp4::Open(void)
  68 {
  69     icmp_sock = socket(PF_INET, SOCK_RAW, IPPROTO_ICMP);
  70
  71     if (icmp_sock < 0) {
  72         int xerrno = errno;
  73         debugs(50, DBG_CRITICAL, MYNAME << " icmp_sock: " << xstrerr(xerrno));
  74         return -1;
  75     }
  76
  77     icmp_ident = getpid() & 0xffff;
  78     debugs(42, DBG_IMPORTANT, "pinger: ICMP socket opened.");
  79
  80     return icmp_sock;
  81 }
  82
  83 void
  84 Icmp4::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  85 {
  86     int x;
  87     LOCAL_ARRAY(char, pkt, MAX_PKT4_SZ);
  88
  89     struct icmphdr *icmp = NULL;
  90     icmpEchoData *echo;
  91     size_t icmp_pktsize = sizeof(struct icmphdr);
  92     struct addrinfo *S = NULL;
  93
  94     memset(pkt, '\0', MAX_PKT4_SZ);
  95
  96     icmp = (struct icmphdr *) (void *) pkt;
  97
  98     /*
  99      * cevans - beware signed/unsigned issues in untrusted data from
 100      * the network!!
 101      */
 102     if (len < 0) {
 103         len = 0;
 104     }
 105
 106     // Construct ICMP packet header
 107     icmp->icmp_type = ICMP_ECHO;
 108     icmp->icmp_code = 0;
 109     icmp->icmp_cksum = 0;
 110     icmp->icmp_id = icmp_ident;
 111     icmp->icmp_seq = (unsigned short) icmp_pkts_sent;
 112     ++icmp_pkts_sent;
 113
 114     // Construct ICMP packet data content
 115     echo = (icmpEchoData *) (icmp + 1);
 116     echo->opcode = (unsigned char) opcode;
 117     memcpy(&echo->tv, &current_time, sizeof(struct timeval));
 118
 119     icmp_pktsize += sizeof(struct timeval) + sizeof(char);
 120
 121     if (payload) {
 122         if (len > MAX_PAYLOAD)
 123             len = MAX_PAYLOAD;
 124
 125         memcpy(echo->payload, payload, len);
 126
 127         icmp_pktsize += len;
 128     }
 129
 130     icmp->icmp_cksum = CheckSum((unsigned short *) icmp, icmp_pktsize);
 131
 132     to.getAddrInfo(S);
 133     ((sockaddr_in*)S->ai_addr)->sin_port = 0;
 134     assert(icmp_pktsize <= MAX_PKT4_SZ);
 135
 136     debugs(42, 5, HERE << "Send ICMP packet to " << to << ".");
 137
 138     x = sendto(icmp_sock,
 139                (const void *) pkt,
 140                icmp_pktsize,
 141                0,
 142                S->ai_addr,
 143                S->ai_addrlen);
 144
 145     if (x < 0) {
 146         int xerrno = errno;
 147         debugs(42, DBG_IMPORTANT, MYNAME << "ERROR: sending to ICMP packet to " << to << ": " << xstrerr(xerrno));
 148     }
 149
 150     Log(to, ' ', NULL, 0, 0);
 151     Ip::Address::FreeAddr(S);
 152 }
 153
 154 void
 155 Icmp4::Recv(void)
 156 {
 157     int n;
 158     struct addrinfo *from = NULL;
 159     int iphdrlen = sizeof(iphdr);
 160     struct iphdr *ip = NULL;
 161     struct icmphdr *icmp = NULL;
 162     static char *pkt = NULL;
 163     struct timeval now;
 164     icmpEchoData *echo;
 165     static pingerReplyData preply;
 166
 167     if (icmp_sock < 0) {
 168         debugs(42, DBG_CRITICAL, HERE << "No socket! Recv() should not be called.");
 169         return;
 170     }
 171
 172     if (pkt == NULL)
 173         pkt = (char *)xmalloc(MAX_PKT4_SZ);
 174
 175     Ip::Address::InitAddr(from);
 176     n = recvfrom(icmp_sock,
 177                  (void *)pkt,
 178                  MAX_PKT4_SZ,
 179                  0,
 180                  from->ai_addr,
 181                  &from->ai_addrlen);
 182
 183     if (n <= 0) {
 184         debugs(42, DBG_CRITICAL, HERE << "Error when calling recvfrom() on ICMP socket.");
 185         Ip::Address::FreeAddr(from);
 186         return;
 187     }
 188
 189     preply.from = *from;
 190
 191 #if GETTIMEOFDAY_NO_TZP
 192
 193     gettimeofday(&now);
 194
 195 #else
 196
 197     gettimeofday(&now, NULL);
 198
 199 #endif
 200
 201     debugs(42, 8, HERE << n << " bytes from " << preply.from);
 202
 203     ip = (struct iphdr *) (void *) pkt;
 204
 205 #if HAVE_STRUCT_IPHDR_IP_HL
 206
 207     iphdrlen = ip->ip_hl << 2;
 208
 209 #else /* HAVE_STRUCT_IPHDR_IP_HL */
 210 #if WORDS_BIGENDIAN
 211
 212     iphdrlen = (ip->ip_vhl >> 4) << 2;
 213
 214 #else
 215
 216     iphdrlen = (ip->ip_vhl & 0xF) << 2;
 217
 218 #endif
 219 #endif /* HAVE_STRUCT_IPHDR_IP_HL */
 220
 221     icmp = (struct icmphdr *) (void *) (pkt + iphdrlen);
 222
 223     if (icmp->icmp_type != ICMP_ECHOREPLY) {
 224         Ip::Address::FreeAddr(from);
 225         return;
 226     }
 227
 228     if (icmp->icmp_id != icmp_ident) {
 229         Ip::Address::FreeAddr(from);
 230         return;
 231     }
 232
 233     echo = (icmpEchoData *) (void *) (icmp + 1);
 234
 235     preply.opcode = echo->opcode;
 236
 237     preply.hops = ipHops(ip->ip_ttl);
 238
 239     struct timeval tv;
 240     memcpy(&tv, &echo->tv, sizeof(struct timeval));
 241     preply.rtt = tvSubMsec(tv, now);
 242
 243     preply.psize = n - iphdrlen - (sizeof(icmpEchoData) - MAX_PKT4_SZ);
 244
 245     if (preply.psize < 0) {
 246         debugs(42, DBG_CRITICAL, HERE << "Malformed ICMP packet.");
 247         Ip::Address::FreeAddr(from);
 248         return;
 249     }
 250
 251     control.SendResult(preply, (sizeof(pingerReplyData) - MAX_PKT4_SZ + preply.psize) );
 252
 253     Log(preply.from, icmp->icmp_type, IcmpPacketType(icmp->icmp_type), preply.rtt, preply.hops);
 254     Ip::Address::FreeAddr(from);
 255 }
 256
 257 #endif /* USE_ICMP */
 258