src/icmp/Icmp.h

   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 37    ICMP Routines */
  10
  11 #ifndef _INCLUDE_ICMP_H
  12 #define _INCLUDE_ICMP_H
  13
  14 #include "ip/Address.h"
  15
  16 #define PINGER_PAYLOAD_SZ   8192
  17
  18 #define MAX_PAYLOAD 256 // WAS: SQUIDHOSTNAMELEN
  19 #define MAX_PKT4_SZ (MAX_PAYLOAD + sizeof(struct timeval) + sizeof (char) + sizeof(struct icmphdr) + 1)
  20 #define MAX_PKT6_SZ (MAX_PAYLOAD + sizeof(struct timeval) + sizeof (char) + sizeof(struct icmp6_hdr) + 1)
  21
  22 #if USE_ICMP
  23
  24 /* This is a line-data format struct. DO NOT alter. */
  25 struct pingerEchoData {
  26     Ip::Address to;
  27     unsigned char opcode;
  28     int psize;
  29     char payload[PINGER_PAYLOAD_SZ];
  30 };
  31
  32 /* This is a line-data format struct. DO NOT alter. */
  33 struct pingerReplyData {
  34     Ip::Address from;
  35     unsigned char opcode;
  36     int rtt;
  37     int hops;
  38     int psize;
  39     char payload[PINGER_PAYLOAD_SZ];
  40 };
  41
  42 struct icmpEchoData {
  43     struct timeval tv;
  44     unsigned char opcode;
  45     char payload[MAX_PAYLOAD];
  46 };
  47
  48 extern int icmp_pkts_sent;
  49
  50 #endif /* USE_ICMP */
  51
  52 /**
  53  * Implements the squid interface to access ICMP operations
  54  *
  55  \par
  56  * Child implementations define specific parts of these operations
  57  * using these methods as a naming and parameter template.
  58  *
  59  * IcmpSquid - implements the squid side of squid-pinger interface
  60  * IcmpPinger - implements the pinger side of the squid-pinger interface
  61  * Icmpv4 - implements pinger helper for Icmpv4
  62  * Icmpv6 - implements pinger helper for Icmpv6
  63  */
  64 class Icmp
  65 {
  66 public:
  67     Icmp();
  68     virtual ~Icmp() {};
  69
  70     /// Start pinger helper and initiate control channel
  71     virtual int Open() =0;
  72
  73     /// Shutdown pinger helper and control channel
  74     virtual void Close();
  75
  76 #if USE_ICMP
  77
  78     /**
  79      * Construct and Send an ECHO request
  80      *
  81      \param to        Destination address being 'pinged'
  82      \param opcode    Specific code for ECHO request, see RFC ????.
  83      \param payload   A payload MAY be sent in the ICMP message.
  84      *                Content longer than MAX_PAYLOAD will be truncated.
  85      \param len       Length of the payload in bytes if any is to be sent or 0.
  86      */
  87     virtual void SendEcho(Ip::Address &to, int opcode, const char *payload=NULL, int len=0) =0;
  88
  89     /// Handle ICMP responses.
  90     virtual void Recv(void) =0;
  91
  92 protected:
  93     /* shared internal methods */
  94
  95     /// Calculate a packet checksum
  96     int CheckSum(unsigned short *ptr, int size);
  97
  98     /**
  99      * Translate TTL to a hop distance
 100      *
 101      \param ttl negative     : n > 33
 102      \param ttl n(0...32)    : 32 >= n >= 1
 103      \param ttl n(33...62)   : 32 >= n >= 1
 104      \param ttl n(63...64)   : 2 >= n >= 1
 105      \param ttl n(65...128)  : 64 >= n >= 1
 106      \param ttl n(129...192) : 64 >= n >= 1
 107      \param ttl n(193...)    : n < 255
 108      *
 109      \bug BUG? ttl<0 can produce high hop values
 110      \bug BUG? ttl>255 can produce zero or negative hop values
 111      */
 112     int ipHops(int ttl);
 113
 114     /// Log the packet.
 115     void Log(const Ip::Address &addr, const uint8_t type, const char* pkt_str, const int rtt, const int hops);
 116
 117     /* no use wasting memory */
 118     int icmp_sock;
 119     int icmp_ident;
 120 #endif /* USE_ICMP */
 121 };
 122
 123 #endif
 124