src/dns/rfc1035.h

   1 /*
   2  * Copyright (C) 1996-2017 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 #ifndef SQUID_RFC1035_H
  10 #define SQUID_RFC1035_H
  11
  12 #if HAVE_SYS_TYPES_H
  13 #include <sys/types.h>
  14 #endif
  15 #if HAVE_NETINET_IN_H
  16 #include <netinet/in.h>
  17 #endif
  18 #if HAVE_ARPA_INET_H
  19 #include <arpa/inet.h>
  20 #endif
  21
  22 #include "rfc2181.h"
  23
  24 /**
  25  \par RFC 1035 Section 3.1:
  26  *  To simplify implementations, the total length of a domain name (i.e.,
  27  *  label octets and label length octets) is restricted to 255 octets or
  28  *  less.
  29  *\par
  30  *  Clarified by RFC 2181 Section 11. (RFC2181_MAXHOSTNAMELEN)
  31  */
  32 #define RFC1035_MAXHOSTNAMESZ RFC2181_MAXHOSTNAMELEN
  33
  34 #define RFC1035_DEFAULT_PACKET_SZ 512
  35
  36 class rfc1035_rr
  37 {
  38 public:
  39     char name[RFC1035_MAXHOSTNAMESZ];
  40     unsigned short type;
  41     unsigned short _class;
  42     unsigned int ttl;
  43     unsigned short rdlength;
  44     char *rdata;
  45 };
  46
  47 typedef struct _rfc1035_query rfc1035_query;
  48 struct _rfc1035_query {
  49     char name[RFC1035_MAXHOSTNAMESZ];
  50     unsigned short qtype;
  51     unsigned short qclass;
  52 };
  53
  54 typedef struct _rfc1035_message rfc1035_message;
  55 struct _rfc1035_message {
  56     unsigned short id;
  57     unsigned int qr:1;
  58     unsigned int opcode:4;
  59     unsigned int aa:1;
  60     unsigned int tc:1;
  61     unsigned int rd:1;
  62     unsigned int ra:1;
  63     unsigned int rcode:4;
  64     unsigned short qdcount;
  65     unsigned short ancount;
  66     unsigned short nscount;
  67     unsigned short arcount;
  68     rfc1035_query *query;
  69     rfc1035_rr *answer;
  70 };
  71
  72 SQUIDCEXTERN ssize_t rfc1035BuildAQuery(const char *hostname,
  73                                         char *buf,
  74                                         size_t sz,
  75                                         unsigned short qid,
  76                                         rfc1035_query * query,
  77                                         ssize_t edns_sz);
  78 SQUIDCEXTERN ssize_t rfc1035BuildPTRQuery(const struct in_addr,
  79         char *buf,
  80         size_t sz,
  81         unsigned short qid,
  82         rfc1035_query * query,
  83         ssize_t edns_sz);
  84 SQUIDCEXTERN void rfc1035SetQueryID(char *, unsigned short qid);
  85 SQUIDCEXTERN int rfc1035MessageUnpack(const char *buf,
  86                                       size_t sz,
  87                                       rfc1035_message ** answer);
  88 SQUIDCEXTERN int rfc1035QueryCompare(const rfc1035_query *, const rfc1035_query *);
  89 SQUIDCEXTERN void rfc1035RRDestroy(rfc1035_rr ** rr, int n);
  90 SQUIDCEXTERN void rfc1035MessageDestroy(rfc1035_message ** message);
  91 SQUIDCEXTERN const char * rfc1035ErrorMessage(int n);
  92
  93 #define RFC1035_TYPE_A 1
  94 #define RFC1035_TYPE_CNAME 5
  95 #define RFC1035_TYPE_PTR 12
  96 #define RFC1035_CLASS_IN 1
  97
  98 /* Child Library RFC3596 Depends on some otherwise internal functions */
  99 SQUIDCEXTERN int rfc1035HeaderPack(char *buf,
 100                                    size_t sz,
 101                                    rfc1035_message * hdr);
 102 SQUIDCEXTERN int rfc1035HeaderUnpack(const char *buf,
 103                                      size_t sz,
 104                                      unsigned int *off,
 105                                      rfc1035_message * h);
 106 SQUIDCEXTERN int rfc1035QuestionPack(char *buf,
 107                                      size_t sz,
 108                                      const char *name,
 109                                      const unsigned short type,
 110                                      const unsigned short _class);
 111 SQUIDCEXTERN int rfc1035RRPack(char *buf, size_t sz, const rfc1035_rr * RR);
 112
 113 #endif /* SQUID_RFC1035_H */
 114