include/res.h

   1 /** @file
   2  * @brief IRC resolver API.
   3  * @version $Id: res.h,v 1.17 2005/06/27 13:25:51 entrope Exp $
   4  */
   5
   6 #ifndef INCLUDED_res_h
   7 #define INCLUDED_res_h
   8
   9 #ifndef INCLUDED_config_h
  10 #include "config.h"
  11 #endif
  12
  13 #ifndef INCLUDED_sys_types_h
  14 #include <sys/types.h>
  15 #define INCLUDED_sys_types_h
  16 #endif
  17
  18 #ifndef INCLUDED_sys_socket_h
  19 #include <sys/socket.h>
  20 #define INCLUDED_sys_socket_h
  21 #endif
  22
  23 #include <netdb.h>
  24
  25 #ifndef INCLUDED_netinet_in_h
  26 #include <netinet/in.h>
  27 #define INCLUDED_netinet_in_h
  28 #endif
  29
  30 #ifdef HAVE_STDINT_H
  31 #ifndef INCLUDED_stdint_h
  32 #include <stdint.h>
  33 #define INCLUDED_stdint_h
  34 #endif
  35 #endif
  36
  37 struct Client;
  38 struct StatDesc;
  39
  40 /* Here we define some values lifted from nameser.h */
  41 #define NS_INT16SZ 2 /**< Size of a 16-bit value. */
  42 #define NS_INT32SZ 4 /**< Size of a 32-bit value. */
  43 #define NS_CMPRSFLGS 0xc0 /**< Prefix flags that indicate special types */
  44 #define NS_MAXCDNAME 255 /**< Maximum length of a compressed domain name. */
  45 #define QUERY 0      /**< Forward (normal) DNS query operation. */
  46 #define NO_ERRORS 0  /**< No errors processing a query. */
  47 #define SERVFAIL 2   /**< Server error while processing a query. */
  48 #define T_A 1        /**< Hostname -> IPv4 query type. */
  49 #define T_AAAA 28    /**< Hostname -> IPv6 query type. */
  50 #define T_PTR 12     /**< IP(v4 or v6) -> hostname query type. */
  51 #define T_CNAME 5    /**< Canonical name resolution query type. */
  52 #define C_IN 1       /**< Internet query class. */
  53 #define QFIXEDSZ 4   /**< Length of fixed-size part of query. */
  54 #define HFIXEDSZ 12  /**< Length of fixed-size DNS header. */
  55
  56 /** Structure to store an IP address. */
  57 struct irc_in_addr
  58 {
  59   unsigned short in6_16[8]; /**< IPv6 encoded parts, little-endian. */
  60 };
  61
  62 /** Structure to store an IP address and port number. */
  63 struct irc_sockaddr
  64 {
  65   struct irc_in_addr addr; /**< IP address. */
  66   unsigned short port;     /**< Port number, host-endian. */
  67 };
  68
  69 /** DNS callback function signature. */
  70 typedef void (*dns_callback_f)(void *vptr, const struct irc_in_addr *addr, const char *h_name);
  71
  72 /** DNS query and response header. */
  73 typedef struct
  74 {
  75         unsigned        id :16;         /**< query identification number */
  76 #ifdef WORDS_BIGENDIAN
  77                         /* fields in third byte */
  78         unsigned        qr: 1;          /**< response flag */
  79         unsigned        opcode: 4;      /**< purpose of message */
  80         unsigned        aa: 1;          /**< authoritive answer */
  81         unsigned        tc: 1;          /**< truncated message */
  82         unsigned        rd: 1;          /**< recursion desired */
  83                         /* fields in fourth byte */
  84         unsigned        ra: 1;          /**< recursion available */
  85         unsigned        unused :1;      /**< unused bits (MBZ as of 4.9.3a3) */
  86         unsigned        ad: 1;          /**< authentic data from named */
  87         unsigned        cd: 1;          /**< checking disabled by resolver */
  88         unsigned        rcode :4;       /**< response code */
  89 #else
  90                         /* fields in third byte */
  91         unsigned        rd :1;          /**< recursion desired */
  92         unsigned        tc :1;          /**< truncated message */
  93         unsigned        aa :1;          /**< authoritive answer */
  94         unsigned        opcode :4;      /**< purpose of message */
  95         unsigned        qr :1;          /**< response flag */
  96                         /* fields in fourth byte */
  97         unsigned        rcode :4;       /**< response code */
  98         unsigned        cd: 1;          /**< checking disabled by resolver */
  99         unsigned        ad: 1;          /**< authentic data from named */
 100         unsigned        unused :1;      /**< unused bits (MBZ as of 4.9.3a3) */
 101         unsigned        ra :1;          /**< recursion available */
 102 #endif
 103                         /* remaining bytes */
 104         unsigned        qdcount :16;    /**< number of question entries */
 105         unsigned        ancount :16;    /**< number of answer entries */
 106         unsigned        nscount :16;    /**< number of authority entries */
 107         unsigned        arcount :16;    /**< number of resource entries */
 108 } HEADER;
 109
 110 extern void restart_resolver(void);
 111 extern void add_local_domain(char *hname, size_t size);
 112 extern size_t cres_mem(struct Client* cptr);
 113 extern void delete_resolver_queries(const void *vptr);
 114 extern void report_dns_servers(struct Client *source_p, const struct StatDesc *sd, char *param);
 115 extern void gethost_byname(const char *name, dns_callback_f callback, void *ctx);
 116 extern void gethost_byaddr(const struct irc_in_addr *addr, dns_callback_f callback, void *ctx);
 117
 118 /** Evaluate to non-zero if \a ADDR is a valid address (not all 0s and not all 1s). */
 119 #define irc_in_addr_valid(ADDR) (((ADDR)->in6_16[0] && ~(ADDR)->in6_16[0]) \
 120                                  || (ADDR)->in6_16[1] != (ADDR)->in6_16[0] \
 121                                  || (ADDR)->in6_16[2] != (ADDR)->in6_16[0] \
 122                                  || (ADDR)->in6_16[3] != (ADDR)->in6_16[0] \
 123                                  || (ADDR)->in6_16[4] != (ADDR)->in6_16[0] \
 124                                  || (ADDR)->in6_16[5] != (ADDR)->in6_16[0] \
 125                                  || (ADDR)->in6_16[6] != (ADDR)->in6_16[0] \
 126                                  || (ADDR)->in6_16[7] != (ADDR)->in6_16[0])
 127 /** Evaluate to non-zero if \a ADDR (of type struct irc_in_addr) is an IPv4 address. */
 128 #define irc_in_addr_is_ipv4(ADDR) (!(ADDR)->in6_16[0] && !(ADDR)->in6_16[1] && !(ADDR)->in6_16[2] \
 129                                    && !(ADDR)->in6_16[3] && !(ADDR)->in6_16[4] && (ADDR)->in6_16[6] \
 130                                    && (!(ADDR)->in6_16[5] || (ADDR)->in6_16[5] == 65535))
 131 /** Evaluate to non-zero if \a A is a different IP than \a B. */
 132 #define irc_in_addr_cmp(A,B) (irc_in_addr_is_ipv4(A) ? ((A)->in6_16[6] != (B)->in6_16[6] \
 133                                   || (A)->in6_16[7] != (B)->in6_16[7] || !irc_in_addr_is_ipv4(B)) \
 134                               : memcmp((A), (B), sizeof(struct irc_in_addr)))
 135 /** Evaluate to non-zero if \a ADDR is a loopback address. */
 136 #define irc_in_addr_is_loopback(ADDR) (!(ADDR)->in6_16[0] && !(ADDR)->in6_16[1] && !(ADDR)->in6_16[2] \
 137                                        && !(ADDR)->in6_16[3] && !(ADDR)->in6_16[4] \
 138                                        && ((!(ADDR)->in6_16[5] \
 139                                             && ((!(ADDR)->in6_16[6] && (ADDR)->in6_16[7] == htons(1)) \
 140                                                 || (ntohs((ADDR)->in6_16[6]) & 0xff00) == 0x7f00)) \
 141                                            || (((ADDR)->in6_16[5] == 65535) \
 142                                                && (ntohs((ADDR)->in6_16[6]) & 0xff00) == 0x7f00)))
 143
 144 #endif