src/icmp/Icmp.h

   1 /*
   2  * Copyright (C) 1996-2021 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 {
  27     pingerEchoData() { memset(&payload, 0, sizeof(payload)); }
  28     Ip::Address to;
  29     unsigned char opcode = '\0';
  30     int psize = 0;
  31     char payload[PINGER_PAYLOAD_SZ];
  32 };
  33
  34 /* This is a line-data format struct. DO NOT alter. */
  35 struct pingerReplyData {
  36     pingerReplyData() { memset(&payload, 0, sizeof(payload)); }
  37     Ip::Address from;
  38     unsigned char opcode = '\0';
  39     int rtt = 0;
  40     int hops = 0;
  41     int psize = 0;
  42     char payload[PINGER_PAYLOAD_SZ];
  43 };
  44
  45 struct icmpEchoData {
  46     struct timeval tv;
  47     unsigned char opcode;
  48     char payload[MAX_PAYLOAD];
  49 };
  50
  51 extern int icmp_pkts_sent;
  52
  53 #endif /* USE_ICMP */
  54
  55 /**
  56  * Implements the squid interface to access ICMP operations
  57  *
  58  \par
  59  * Child implementations define specific parts of these operations
  60  * using these methods as a naming and parameter template.
  61  *
  62  * IcmpSquid - implements the squid side of squid-pinger interface
  63  * IcmpPinger - implements the pinger side of the squid-pinger interface
  64  * Icmpv4 - implements pinger helper for Icmpv4
  65  * Icmpv6 - implements pinger helper for Icmpv6
  66  */
  67 class Icmp
  68 {
  69 public:
  70     Icmp();
  71     virtual ~Icmp() {}
  72
  73     /// Start pinger helper and initiate control channel
  74     virtual int Open() =0;
  75
  76     /// Shutdown pinger helper and control channel
  77     virtual void Close();
  78
  79 #if USE_ICMP
  80
  81     /**
  82      * Construct and Send an ECHO request
  83      *
  84      \param to        Destination address being 'pinged'
  85      \param opcode    Specific code for ECHO request, see RFC ????.
  86      \param payload   A payload MAY be sent in the ICMP message.
  87      *                Content longer than MAX_PAYLOAD will be truncated.
  88      \param len       Length of the payload in bytes if any is to be sent or 0.
  89      */
  90     virtual void SendEcho(Ip::Address &to, int opcode, const char *payload=NULL, int len=0) =0;
  91
  92     /// Handle ICMP responses.
  93     virtual void Recv(void) =0;
  94
  95 protected:
  96     /* shared internal methods */
  97
  98     /// Calculate a packet checksum
  99     int CheckSum(unsigned short *ptr, int size);
 100
 101     /**
 102      * Translate TTL to a hop distance
 103      *
 104      \param ttl negative     : n > 33
 105      \param ttl n(0...32)    : 32 >= n >= 1
 106      \param ttl n(33...62)   : 32 >= n >= 1
 107      \param ttl n(63...64)   : 2 >= n >= 1
 108      \param ttl n(65...128)  : 64 >= n >= 1
 109      \param ttl n(129...192) : 64 >= n >= 1
 110      \param ttl n(193...)    : n < 255
 111      *
 112      \bug BUG? ttl<0 can produce high hop values
 113      \bug BUG? ttl>255 can produce zero or negative hop values
 114      */
 115     int ipHops(int ttl);
 116
 117     /// Log the packet.
 118     void Log(const Ip::Address &addr, const uint8_t type, const char* pkt_str, const int rtt, const int hops);
 119
 120     /* no use wasting memory */
 121     int icmp_sock;
 122     int icmp_ident;
 123 #endif /* USE_ICMP */
 124 };
 125
 126 #endif
 127