dns.h

#ifndef DNS_H
#define DNS_H

#include "sysdeps.h"
#include "systime.h"
#include "ipv4.h"
#include "ipv6.h"
#include "str.h"
#include "uint16.h"

#define TV_LESS(A,B) (((A)->tv_sec < (B)->tv_sec) || ((A)->tv_sec == (B)->tv_sec && (A)->tv_usec < (B)->tv_usec))

#define DNS_C_IN 1

#define DNS_C_ANY 255

#define DNS_T_A 1

#define DNS_T_NS 2

#define DNS_T_CNAME 5

#define DNS_T_SOA 6

#define DNS_T_PTR 12

#define DNS_T_HINFO 13

#define DNS_T_MX 15

#define DNS_T_TXT 16

#define DNS_T_RP 17

#define DNS_T_SIG 24

#define DNS_T_KEY 25

#define DNS_T_AAAA 28

#define DNS_T_AXFR 252

#define DNS_T_ANY 255

#define DNS_RANDOM_SEED (32*4)

#define DNS_MAX_IPS 16

#define DNS_NAME4_DOMAIN (4*4+14)

#define DNS_NAME6_DOMAIN (32*2+10)

struct dns_transmit {
  char *query;
  unsigned int querylen;
  char *packet;
  unsigned int packetlen;
  int s1;
  int tcpstate;
  unsigned int udploop;
  unsigned int curserver;
  struct timeval deadline;
  unsigned int pos;
  const ipv4addr *servers;
  ipv4addr localip;
  uint16 qtype;
};

struct dns_mx
{
  uint16 distance;
  char* name;
};

union dns_result_rrs
{
  void* __ptr;
  ipv4addr* ip4;
  ipv6addr* ip6;
  struct dns_mx* mx;
  char** name;
};

struct dns_result
{
  int count;
  int type;
  union dns_result_rrs rr;
  void* __buffer;
};

extern int dns_result_alloc(struct dns_result* d, int type, int count, int size);
extern void dns_result_free(struct dns_result* d);

extern void dns_random_init(const char [DNS_RANDOM_SEED]);
extern unsigned int dns_random(unsigned int);

extern void dns_rotate(unsigned char*, unsigned int n, unsigned int shift);
extern void dns_rotateipv4(ipv4addr*, unsigned int);
extern void dns_rotateipv6(ipv6addr*, unsigned int);

extern void dns_sort_mx(struct dns_mx* mxs, int count);

extern void dns_domain_free(char **);
extern int dns_domain_copy(char **,const char *);
extern unsigned int dns_domain_length(const char *);
extern int dns_domain_equal(const char *,const char *);
extern int dns_domain_suffix(const char *,const char *);
extern unsigned int dns_domain_suffixpos(const char *,const char *);
extern int dns_domain_fromdot(char **,const char *,unsigned int);
extern int dns_domain_todot_cat(str *,const char *);

extern unsigned int dns_packet_copy(const char *,unsigned int,unsigned int,unsigned char *,unsigned int);
extern unsigned int dns_packet_getname(const char *,unsigned int,unsigned int,char **);
extern unsigned int dns_packet_skipname(const char *,unsigned int,unsigned int);
extern int dns_packet_extract(struct dns_result* out, const char* buf, unsigned int len, uint16 rrtype, uint16 rrclass,
                              int (*sizefn)(const char* buf, unsigned int len, unsigned int pos, uint16 datalen),
                              int (*copy)(struct dns_result* out, unsigned int index, unsigned int offset,
                                          const char* buf, unsigned int len, unsigned int pos, uint16 datalen));

extern int dns_transmit_start(struct dns_transmit *,const ipv4addr [DNS_MAX_IPS],int,const char *,uint16,const ipv4addr *);
extern void dns_transmit_free(struct dns_transmit *);
extern void dns_transmit_io(const struct dns_transmit *,iopoll_fd *,struct timeval *);
extern int dns_transmit_get(struct dns_transmit *,const iopoll_fd *,const struct timeval *);

extern int dns_read_resolvconf(str *out);
extern int dns_resolvconfip(ipv4addr [DNS_MAX_IPS]);
extern int dns_resolve(struct dns_transmit *,const char *,uint16);

extern int dns_ip4_packet(struct dns_result*, const char*, unsigned int);
extern int dns_ip4_r(struct dns_transmit*, struct dns_result*, const char *);
extern int dns_ip4(struct dns_result*, const char *);
extern int dns_ip6_packet(struct dns_result*, const char*, unsigned int);
extern int dns_ip6_r(struct dns_transmit*, struct dns_result*, const char *);
extern int dns_ip6(struct dns_result*, const char*);
extern int dns_name_packet(struct dns_result*, const char *,unsigned int);
extern void dns_name4_domain(char [DNS_NAME4_DOMAIN],const ipv4addr *);
extern void dns_name6_domain(char [DNS_NAME6_DOMAIN],const ipv6addr *);
extern int dns_name4_r(struct dns_transmit*, struct dns_result*, const ipv4addr*);
extern int dns_name4(struct dns_result*, const ipv4addr*);
extern int dns_name6_r(struct dns_transmit*, struct dns_result*, const ipv6addr*);
extern int dns_name6(struct dns_result*, const ipv6addr*);
extern int dns_txt_packet(struct dns_result*, const char *,unsigned int);
extern int dns_txt_r(struct dns_transmit *,struct dns_result*, const char *);
extern int dns_txt(struct dns_result*, const char *);
extern int dns_mx_packet(struct dns_result*, const char *,unsigned int);
extern int dns_mx_r(struct dns_transmit *,struct dns_result*, const char *);
extern int dns_mx(struct dns_result*, const char *);

extern int dns_resolvconfrewrite(str *);
extern int dns_qualify_rules(struct dns_result*,str *,const char *,const str *,
                             int (*)(struct dns_transmit*, struct dns_result*, const char*));
extern int dns_qualify(struct dns_result*,str *,const char *,
                       int (*)(struct dns_transmit*, struct dns_result*, const char*));

extern unsigned fmt_dns_domain(char*, const char*);

#define DNS_R_FN_WRAP(NAME,TYPE)                        \
  int dns_##NAME(struct dns_result* out,TYPE in)        \
  {                                                     \
    struct dns_transmit tx = {0};                       \
    int r = dns_##NAME##_r(&tx,out,in);                 \
    dns_transmit_free(&tx);                             \
    return r;                                           \
  }

#endif