include/reslib.h

   1 /*
   2  * include/irc_reslib.h
   3  *
   4  * $Id: reslib.h 446 2006-02-12 02:46:54Z db $
   5  */
   6
   7 #ifndef _CHARYBDIS_RESLIB_H
   8 #define _CHARYBDIS_RESLIB_H
   9
  10 /* Longest hostname we're willing to work with.
  11  * Due to DNSBLs this is more than HOSTLEN.
  12  */
  13 #define IRCD_RES_HOSTLEN 255
  14
  15 /* Here we define some values lifted from nameser.h */
  16 #define NS_NOTIFY_OP 4
  17 #define NS_INT16SZ 2
  18 #define NS_IN6ADDRSZ    16
  19 #define NS_INADDRSZ      4
  20 #define NS_INT32SZ 4
  21 #define NS_CMPRSFLGS    0xc0
  22 #define NS_MAXCDNAME 255
  23 #define QUERY 0
  24 #define IQUERY 1
  25 #define NO_ERRORS 0
  26 #define SERVFAIL 2
  27 #define NXDOMAIN 3
  28 #define T_A 1
  29 #define T_AAAA 28
  30 #define T_PTR 12
  31 #define T_CNAME 5
  32 #define T_NULL 10
  33 #define C_IN 1
  34 #define QFIXEDSZ 4
  35 #define RRFIXEDSZ 10
  36 #define HFIXEDSZ 12
  37
  38 typedef struct
  39 {
  40         unsigned        id :16;         /* query identification number */
  41 #ifdef WORDS_BIGENDIAN
  42                         /* fields in third byte */
  43         unsigned        qr: 1;          /* response flag */
  44         unsigned        opcode: 4;      /* purpose of message */
  45         unsigned        aa: 1;          /* authoritive answer */
  46         unsigned        tc: 1;          /* truncated message */
  47         unsigned        rd: 1;          /* recursion desired */
  48                         /* fields in fourth byte */
  49         unsigned        ra: 1;          /* recursion available */
  50         unsigned        unused :1;      /* unused bits (MBZ as of 4.9.3a3) */
  51         unsigned        ad: 1;          /* authentic data from named */
  52         unsigned        cd: 1;          /* checking disabled by resolver */
  53         unsigned        rcode :4;       /* response code */
  54 #else
  55                         /* fields in third byte */
  56         unsigned        rd :1;          /* recursion desired */
  57         unsigned        tc :1;          /* truncated message */
  58         unsigned        aa :1;          /* authoritive answer */
  59         unsigned        opcode :4;      /* purpose of message */
  60         unsigned        qr :1;          /* response flag */
  61                         /* fields in fourth byte */
  62         unsigned        rcode :4;       /* response code */
  63         unsigned        cd: 1;          /* checking disabled by resolver */
  64         unsigned        ad: 1;          /* authentic data from named */
  65         unsigned        unused :1;      /* unused bits (MBZ as of 4.9.3a3) */
  66         unsigned        ra :1;          /* recursion available */
  67 #endif
  68                         /* remaining bytes */
  69         unsigned        qdcount :16;    /* number of question entries */
  70         unsigned        ancount :16;    /* number of answer entries */
  71         unsigned        nscount :16;    /* number of authority entries */
  72         unsigned        arcount :16;    /* number of resource entries */
  73 } HEADER;
  74
  75 /*
  76  * Inline versions of get/put short/long.  Pointer is advanced.
  77  */
  78 #define IRC_NS_GET16(s, cp) { \
  79         const unsigned char *t_cp = (const unsigned char *)(cp); \
  80         (s) = ((u_int16_t)t_cp[0] << 8) \
  81             | ((u_int16_t)t_cp[1]) \
  82             ; \
  83         (cp) += NS_INT16SZ; \
  84 }
  85
  86 #define IRC_NS_GET32(l, cp) { \
  87         const unsigned char *t_cp = (const unsigned char *)(cp); \
  88         (l) = ((u_int32_t)t_cp[0] << 24) \
  89             | ((u_int32_t)t_cp[1] << 16) \
  90             | ((u_int32_t)t_cp[2] << 8) \
  91             | ((u_int32_t)t_cp[3]) \
  92             ; \
  93         (cp) += NS_INT32SZ; \
  94 }
  95
  96 #define IRC_NS_PUT16(s, cp) { \
  97         u_int16_t t_s = (u_int16_t)(s); \
  98         unsigned char *t_cp = (unsigned char *)(cp); \
  99         *t_cp++ = t_s >> 8; \
 100         *t_cp   = t_s; \
 101         (cp) += NS_INT16SZ; \
 102 }
 103
 104 #define IRC_NS_PUT32(l, cp) { \
 105         u_int32_t t_l = (u_int32_t)(l); \
 106         unsigned char *t_cp = (unsigned char *)(cp); \
 107         *t_cp++ = t_l >> 24; \
 108         *t_cp++ = t_l >> 16; \
 109         *t_cp++ = t_l >> 8; \
 110         *t_cp   = t_l; \
 111         (cp) += NS_INT32SZ; \
 112 }
 113
 114 extern int irc_res_init(void);
 115 extern int irc_dn_expand(const unsigned char *msg, const unsigned char *eom, const unsigned char *src, char *dst, int dstsiz);
 116 extern int irc_dn_skipname(const unsigned char *ptr, const unsigned char *eom);
 117 extern unsigned int irc_ns_get16(const unsigned char *src);
 118 extern unsigned long irc_ns_get32(const unsigned char *src);
 119 extern void irc_ns_put16(unsigned int src, unsigned char *dst);
 120 extern void irc_ns_put32(unsigned long src, unsigned char *dst);
 121 extern int irc_res_mkquery(const char *dname, int class, int type, unsigned char *buf, int buflen);
 122
 123 extern char irc_domain[IRCD_RES_HOSTLEN + 1];
 124
 125 #endif