src/icmp/Icmp4.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 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         debugs(50, DBG_CRITICAL, HERE << " icmp_sock: " << xstrerror());
  73         return -1;
  74     }
  75
  76     icmp_ident = getpid() & 0xffff;
  77     debugs(42, DBG_IMPORTANT, "pinger: ICMP socket opened.");
  78
  79     return icmp_sock;
  80 }
  81
  82 void
  83 Icmp4::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  84 {
  85     int x;
  86     LOCAL_ARRAY(char, pkt, MAX_PKT4_SZ);
  87
  88     struct icmphdr *icmp = NULL;
  89     icmpEchoData *echo;
  90     size_t icmp_pktsize = sizeof(struct icmphdr);
  91     struct addrinfo *S = NULL;
  92
  93     memset(pkt, '\0', MAX_PKT4_SZ);
  94
  95     icmp = (struct icmphdr *) (void *) pkt;
  96
  97     /*
  98      * cevans - beware signed/unsigned issues in untrusted data from
  99      * the network!!
 100      */
 101     if (len < 0) {
 102         len = 0;
 103     }
 104
 105     // Construct ICMP packet header
 106     icmp->icmp_type = ICMP_ECHO;
 107     icmp->icmp_code = 0;
 108     icmp->icmp_cksum = 0;
 109     icmp->icmp_id = icmp_ident;
 110     icmp->icmp_seq = (unsigned short) icmp_pkts_sent;
 111     ++icmp_pkts_sent;
 112
 113     // Construct ICMP packet data content
 114     echo = (icmpEchoData *) (icmp + 1);
 115     echo->opcode = (unsigned char) opcode;
 116     memcpy(&echo->tv, &current_time, sizeof(struct timeval));
 117
 118     icmp_pktsize += sizeof(struct timeval) + sizeof(char);
 119
 120     if (payload) {
 121         if (len > MAX_PAYLOAD)
 122             len = MAX_PAYLOAD;
 123
 124         memcpy(echo->payload, payload, len);
 125
 126         icmp_pktsize += len;
 127     }
 128
 129     icmp->icmp_cksum = CheckSum((unsigned short *) icmp, icmp_pktsize);
 130
 131     to.getAddrInfo(S);
 132     ((sockaddr_in*)S->ai_addr)->sin_port = 0;
 133     assert(icmp_pktsize <= MAX_PKT4_SZ);
 134
 135     debugs(42, 5, HERE << "Send ICMP packet to " << to << ".");
 136
 137     x = sendto(icmp_sock,
 138                (const void *) pkt,
 139                icmp_pktsize,
 140                0,
 141                S->ai_addr,
 142                S->ai_addrlen);
 143
 144     if (x < 0) {
 145         debugs(42, DBG_IMPORTANT, HERE << "Error sending to ICMP packet to " << to << ". ERR: " << xstrerror());
 146     }
 147
 148     Log(to, ' ', NULL, 0, 0);
 149     Ip::Address::FreeAddr(S);
 150 }
 151
 152 void
 153 Icmp4::Recv(void)
 154 {
 155     int n;
 156     struct addrinfo *from = NULL;
 157     int iphdrlen = sizeof(iphdr);
 158     struct iphdr *ip = NULL;
 159     struct icmphdr *icmp = NULL;
 160     static char *pkt = NULL;
 161     struct timeval now;
 162     icmpEchoData *echo;
 163     static pingerReplyData preply;
 164
 165     if (icmp_sock < 0) {
 166         debugs(42, DBG_CRITICAL, HERE << "No socket! Recv() should not be called.");
 167         return;
 168     }
 169
 170     if (pkt == NULL)
 171         pkt = (char *)xmalloc(MAX_PKT4_SZ);
 172
 173     Ip::Address::InitAddr(from);
 174     n = recvfrom(icmp_sock,
 175                  (void *)pkt,
 176                  MAX_PKT4_SZ,
 177                  0,
 178                  from->ai_addr,
 179                  &from->ai_addrlen);
 180
 181     if (n <= 0) {
 182         debugs(42, DBG_CRITICAL, HERE << "Error when calling recvfrom() on ICMP socket.");
 183         Ip::Address::FreeAddr(from);
 184         return;
 185     }
 186
 187     preply.from = *from;
 188
 189 #if GETTIMEOFDAY_NO_TZP
 190
 191     gettimeofday(&now);
 192
 193 #else
 194
 195     gettimeofday(&now, NULL);
 196
 197 #endif
 198
 199     debugs(42, 8, HERE << n << " bytes from " << preply.from);
 200
 201     ip = (struct iphdr *) (void *) pkt;
 202
 203 #if HAVE_STRUCT_IPHDR_IP_HL
 204
 205     iphdrlen = ip->ip_hl << 2;
 206
 207 #else /* HAVE_STRUCT_IPHDR_IP_HL */
 208 #if WORDS_BIGENDIAN
 209
 210     iphdrlen = (ip->ip_vhl >> 4) << 2;
 211
 212 #else
 213
 214     iphdrlen = (ip->ip_vhl & 0xF) << 2;
 215
 216 #endif
 217 #endif /* HAVE_STRUCT_IPHDR_IP_HL */
 218
 219     icmp = (struct icmphdr *) (void *) (pkt + iphdrlen);
 220
 221     if (icmp->icmp_type != ICMP_ECHOREPLY) {
 222         Ip::Address::FreeAddr(from);
 223         return;
 224     }
 225
 226     if (icmp->icmp_id != icmp_ident) {
 227         Ip::Address::FreeAddr(from);
 228         return;
 229     }
 230
 231     echo = (icmpEchoData *) (void *) (icmp + 1);
 232
 233     preply.opcode = echo->opcode;
 234
 235     preply.hops = ipHops(ip->ip_ttl);
 236
 237     struct timeval tv;
 238     memcpy(&tv, &echo->tv, sizeof(struct timeval));
 239     preply.rtt = tvSubMsec(tv, now);
 240
 241     preply.psize = n - iphdrlen - (sizeof(icmpEchoData) - MAX_PKT4_SZ);
 242
 243     if (preply.psize < 0) {
 244         debugs(42, DBG_CRITICAL, HERE << "Malformed ICMP packet.");
 245         Ip::Address::FreeAddr(from);
 246         return;
 247     }
 248
 249     control.SendResult(preply, (sizeof(pingerReplyData) - MAX_PKT4_SZ + preply.psize) );
 250
 251     Log(preply.from, icmp->icmp_type, IcmpPacketType(icmp->icmp_type), preply.rtt, preply.hops);
 252     Ip::Address::FreeAddr(from);
 253 }
 254
 255 #endif /* USE_ICMP */
 256