pdns/dnspcap.hh

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #pragma once
  23 #include <cstdio>
  24 #include <stdexcept>
  25 #include "iputils.hh"
  26 #include <string>
  27 #include "misc.hh"
  28 #include <iostream>
  29 #define __FAVOR_BSD
  30 #include <netinet/in_systm.h>
  31 #include <netinet/ip.h>
  32 #include <netinet/ip6.h>
  33 #include <netinet/udp.h>
  34 #if defined(__NetBSD__)
  35 #include <net/if.h>
  36 #include <net/if_ether.h>
  37 #elif defined (__OpenBSD__)
  38 #include <net/if.h>
  39 #include <netinet/if_ether.h>
  40 #elif defined (__SVR4) && defined (__sun)
  41 #include <sys/ethernet.h>
  42 #else
  43 #include <net/ethernet.h>
  44 #endif
  45
  46 #include "namespaces.hh"
  47
  48 struct pdns_pcap_file_header {
  49   uint32_t magic;
  50   uint16_t version_major;
  51   uint16_t version_minor;
  52   uint32_t thiszone;     /* gmt to local correction */
  53   uint32_t sigfigs;    /* accuracy of timestamps */
  54   uint32_t snaplen;    /* max length saved portion of each pkt */
  55   uint32_t linktype;   /* data link type (LINKTYPE_*) */
  56 };
  57
  58
  59 struct pdns_timeval
  60 {
  61   uint32_t tv_sec{0};
  62   uint32_t tv_usec{0};
  63 };
  64
  65 struct pdns_pcap_pkthdr {
  66   struct pdns_timeval ts;      /* time stamp */
  67   uint32_t caplen{0};     /* length of portion present */
  68   uint32_t len{0};        /* length this packet (off wire) */
  69 };
  70
  71 struct pdns_lcc_header {
  72   uint16_t lcc_pkttype;/* packet type */
  73   uint16_t lcc_hatype;/* link-layer address type */
  74   uint16_t lcc_halen;/* link-layer address length */
  75   uint8_t lcc_addr[8];/* link-layer address */
  76   uint16_t lcc_protocol;/* protocol */
  77 };
  78
  79 class PcapPacketReader
  80 {
  81 public:
  82   class EofException : public runtime_error
  83   {
  84   public:
  85     EofException(const string& str="PcapPacketReader::EofException") : runtime_error(str)
  86     {
  87     }
  88   };
  89
  90   PcapPacketReader(const string& fname);
  91
  92   template<typename T>
  93   void checkedFread(T* ptr)
  94   {
  95     checkedFreadSize(ptr, sizeof(*ptr));
  96   }
  97
  98   void checkedFreadSize(void* ptr, size_t size) ;
  99
 100   bool getUDPPacket();
 101
 102   ComboAddress getSource() const;
 103   ComboAddress getDest() const;
 104
 105   struct pdns_lcc_header* d_lcc{nullptr};
 106   struct ether_header* d_ether{nullptr};
 107   struct ip *d_ip{nullptr};
 108   struct ip6_hdr *d_ip6{nullptr};
 109   const struct tcphdr *d_tcp{nullptr};
 110   const struct udphdr *d_udp{nullptr};
 111   const uint8_t* d_payload{nullptr};
 112   unsigned int d_len{0};
 113   struct pdns_pcap_pkthdr d_pheader;
 114
 115   pdns_pcap_file_header d_pfh;
 116   unsigned int d_runts, d_oversized, d_correctpackets, d_nonetheripudp;
 117   alignas (struct ip) char d_readbuffer[32768];
 118   char *d_buffer;
 119   size_t d_bufsize;
 120 private:
 121   pdns::UniqueFilePtr d_fp{nullptr};
 122   string d_fname;
 123   unsigned int d_skipMediaHeader;
 124 };
 125
 126 class PcapPacketWriter
 127 {
 128 public:
 129   PcapPacketWriter(const string& fname, const PcapPacketReader& ppr);
 130   PcapPacketWriter(const string& fname);
 131
 132   void write();
 133   void setPPR(const PcapPacketReader& ppr) { d_ppr = &ppr; }
 134
 135 private:
 136   string d_fname;
 137   const PcapPacketReader* d_ppr{nullptr};
 138
 139   pdns::UniqueFilePtr d_fp{nullptr};
 140   bool d_first{true};
 141 };