src/icmp/Icmp.h

   1 /*
   2  * DEBUG: section 37    ICMP Routines
   3  * AUTHOR: Duane Wessels, Amos Jeffries
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32 #ifndef _INCLUDE_ICMP_H
  33 #define _INCLUDE_ICMP_H
  34
  35 #include "ip/Address.h"
  36
  37 #define PINGER_PAYLOAD_SZ       8192
  38
  39 #define MAX_PAYLOAD 256 // WAS: SQUIDHOSTNAMELEN
  40 #define MAX_PKT4_SZ (MAX_PAYLOAD + sizeof(struct timeval) + sizeof (char) + sizeof(struct icmphdr) + 1)
  41 #define MAX_PKT6_SZ (MAX_PAYLOAD + sizeof(struct timeval) + sizeof (char) + sizeof(struct icmp6_hdr) + 1)
  42
  43 #if USE_ICMP
  44
  45 /* This is a line-data format struct. DO NOT alter. */
  46 struct pingerEchoData {
  47     Ip::Address to;
  48     unsigned char opcode;
  49     int psize;
  50     char payload[PINGER_PAYLOAD_SZ];
  51 };
  52
  53 /* This is a line-data format struct. DO NOT alter. */
  54 struct pingerReplyData {
  55     Ip::Address from;
  56     unsigned char opcode;
  57     int rtt;
  58     int hops;
  59     int psize;
  60     char payload[PINGER_PAYLOAD_SZ];
  61 };
  62
  63 struct icmpEchoData {
  64     struct timeval tv;
  65     unsigned char opcode;
  66     char payload[MAX_PAYLOAD];
  67 };
  68
  69 SQUIDCEXTERN int icmp_pkts_sent;
  70
  71 #endif /* USE_ICMP */
  72
  73
  74 /**
  75  * Implements the squid interface to access ICMP operations
  76  *
  77  \par
  78  * Child implementations define specific parts of these operations
  79  * using these methods as a naming and parameter template.
  80  *
  81  * IcmpSquid - implements the squid side of squid-pinger interface
  82  * IcmpPinger - implements the pinger side of the squid-pinger interface
  83  * Icmpv4 - implements pinger helper for Icmpv4
  84  * Icmpv6 - implements pinger helper for Icmpv6
  85  */
  86 class Icmp
  87 {
  88 public:
  89     Icmp();
  90     virtual ~Icmp() {};
  91
  92     /// Start pinger helper and initiate control channel
  93     virtual int Open() =0;
  94
  95     /// Shutdown pinger helper and control channel
  96     virtual void Close();
  97
  98 #if USE_ICMP
  99
 100     /**
 101      * Construct and Send an ECHO request
 102      *
 103      \param to        Destination address being 'pinged'
 104      \param opcode    Specific code for ECHO request, see RFC ????.
 105      \param payload   A payload MAY be sent in the ICMP message.
 106      *                Content longer than MAX_PAYLOAD will be truncated.
 107      \param len       Length of the payload in bytes if any is to be sent or 0.
 108      */
 109     virtual void SendEcho(Ip::Address &to, int opcode, const char *payload=NULL, int len=0) =0;
 110
 111     /// Handle ICMP responses.
 112     virtual void Recv(void) =0;
 113
 114 protected:
 115     /* shared internal methods */
 116
 117     /// Calculate a packet checksum
 118     int CheckSum(unsigned short *ptr, int size);
 119
 120     /**
 121      * Translate TTL to a hop distance
 122      *
 123      \param ttl negative     : n > 33
 124      \param ttl n(0...32)    : 32 >= n >= 1
 125      \param ttl n(33...62)   : 32 >= n >= 1
 126      \param ttl n(63...64)   : 2 >= n >= 1
 127      \param ttl n(65...128)  : 64 >= n >= 1
 128      \param ttl n(129...192) : 64 >= n >= 1
 129      \param ttl n(193...)    : n < 255
 130      *
 131      \bug BUG? ttl<0 can produce high hop values
 132      \bug BUG? ttl>255 can produce zero or negative hop values
 133      */
 134     int ipHops(int ttl);
 135
 136     /// Log the packet.
 137     void Log(const Ip::Address &addr, const uint8_t type, const char* pkt_str, const int rtt, const int hops);
 138
 139     /* no use wasting memory */
 140     int icmp_sock;
 141     int icmp_ident;
 142 #endif /* USE_ICMP */
 143 };
 144
 145 #endif