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 "config.h"
  36 #include "ip/Address.h"
  37
  38 #define PINGER_PAYLOAD_SZ       8192
  39
  40 #define MAX_PAYLOAD 256 // WAS: SQUIDHOSTNAMELEN
  41 #define MAX_PKT4_SZ (MAX_PAYLOAD + sizeof(struct timeval) + sizeof (char) + sizeof(struct icmphdr) + 1)
  42 #if USE_IPV6
  43 #define MAX_PKT6_SZ (MAX_PAYLOAD + sizeof(struct timeval) + sizeof (char) + sizeof(struct icmp6_hdr) + 1)
  44 #endif
  45
  46 #if USE_ICMP
  47
  48 /* This is a line-data format struct. DO NOT alter. */
  49 struct pingerEchoData {
  50     Ip::Address to;
  51     unsigned char opcode;
  52     int psize;
  53     char payload[PINGER_PAYLOAD_SZ];
  54 };
  55
  56 /* This is a line-data format struct. DO NOT alter. */
  57 struct pingerReplyData {
  58     Ip::Address from;
  59     unsigned char opcode;
  60     int rtt;
  61     int hops;
  62     int psize;
  63     char payload[PINGER_PAYLOAD_SZ];
  64 };
  65
  66 struct icmpEchoData {
  67     struct timeval tv;
  68     unsigned char opcode;
  69     char payload[MAX_PAYLOAD];
  70 };
  71
  72 SQUIDCEXTERN int icmp_pkts_sent;
  73
  74 #endif /* USE_ICMP */
  75
  76
  77 /**
  78  * Implements the squid interface to access ICMP operations
  79  *
  80  \par
  81  * Child implementations define specific parts of these operations
  82  * using these methods as a naming and parameter template.
  83  *
  84  * IcmpSquid - implements the squid side of squid-pinger interface
  85  * IcmpPinger - implements the pinger side of the squid-pinger interface
  86  * Icmpv4 - implements pinger helper for Icmpv4
  87  * Icmpv6 - implements pinger helper for Icmpv6
  88  */
  89 class Icmp
  90 {
  91 public:
  92     Icmp();
  93     virtual ~Icmp() {};
  94
  95     /// Start pinger helper and initiate control channel
  96     virtual int Open() =0;
  97
  98     /// Shutdown pinger helper and control channel
  99     virtual void Close();
 100
 101 #if USE_ICMP
 102
 103     /**
 104      * Construct and Send an ECHO request
 105      *
 106      \param to        Destination address being 'pinged'
 107      \param opcode    Specific code for ECHO request, see RFC ????.
 108      \param payload   A payload MAY be sent in the ICMP message.
 109      *                Content longer than MAX_PAYLOAD will be truncated.
 110      \param len       Length of the payload in bytes if any is to be sent or 0.
 111      */
 112     virtual void SendEcho(Ip::Address &to, int opcode, const char *payload=NULL, int len=0) =0;
 113
 114     /// Handle ICMP responses.
 115     virtual void Recv(void) =0;
 116
 117 protected:
 118     /* shared internal methods */
 119
 120     /// Calculate a packet checksum
 121     int CheckSum(unsigned short *ptr, int size);
 122
 123     /**
 124      * Translate TTL to a hop distance
 125      *
 126      \param ttl negative     : n > 33
 127      \param ttl n(0...32)    : 32 >= n >= 1
 128      \param ttl n(33...62)   : 32 >= n >= 1
 129      \param ttl n(63...64)   : 2 >= n >= 1
 130      \param ttl n(65...128)  : 64 >= n >= 1
 131      \param ttl n(129...192) : 64 >= n >= 1
 132      \param ttl n(193...)    : n < 255
 133      *
 134      \bug BUG? ttl<0 can produce high hop values
 135      \bug BUG? ttl>255 can produce zero or negative hop values
 136      */
 137     int ipHops(int ttl);
 138
 139     /// Log the packet.
 140     void Log(const Ip::Address &addr, const uint8_t type, const char* pkt_str, const int rtt, const int hops);
 141
 142     /* no use wasting memory */
 143     int icmp_sock;
 144     int icmp_ident;
 145 #endif /* USE_ICMP */
 146 };
 147
 148 #endif