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gnupg/dirmngr/dns.h

1322 lines
34 KiB

/* ==========================================================================
* dns.h - Recursive, Reentrant DNS Resolver.
* --------------------------------------------------------------------------
* Copyright (c) 2009, 2010, 2012-2015 William Ahern
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to permit
* persons to whom the Software is furnished to do so, subject to the
* following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
* NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
* ==========================================================================
*/
#ifndef DNS_H
#define DNS_H
#include <stddef.h> /* size_t offsetof() */
#include <stdint.h> /* uint64_t */
#include <stdio.h> /* FILE */
#include <string.h> /* strlen(3) */
#include <time.h> /* struct timespec time_t */
#if _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#else
#include <sys/param.h> /* BYTE_ORDER BIG_ENDIAN _BIG_ENDIAN */
#include <sys/types.h> /* socklen_t */
#include <sys/socket.h> /* struct socket */
#include <poll.h> /* POLLIN POLLOUT */
#include <netinet/in.h> /* struct in_addr struct in6_addr */
#include <netdb.h> /* struct addrinfo */
#endif
/*
* V I S I B I L I T Y
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#ifndef DNS_PUBLIC
#define DNS_PUBLIC
#endif
/*
* V E R S I O N
*
* Vendor: Entity for which versions numbers are relevant. (If forking
* change DNS_VENDOR to avoid confusion.)
*
* Three versions:
*
* REL Official "release"--bug fixes, new features, etc.
* ABI Changes to existing object sizes or parameter types
* API Changes that might effect application source.
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#define DNS_VENDOR "william@25thandClement.com"
#define DNS_V_REL 0x20160809
#define DNS_V_ABI 0x20160608
#define DNS_V_API 0x20160809
DNS_PUBLIC const char *dns_vendor(void);
DNS_PUBLIC int dns_v_rel(void);
DNS_PUBLIC int dns_v_abi(void);
DNS_PUBLIC int dns_v_api(void);
/*
* E R R O R S
*
* Errors and exceptions are always returned through an int. This should
* hopefully make integration easier in the majority of circumstances, and
* also cut down on useless compiler warnings.
*
* System and library errors are returned together. POSIX guarantees that
* all system errors are positive integers. Library errors are always
* negative integers in the range DNS_EBASE to DNS_ELAST, with the high bits
* set to the three magic ASCII characters "dns".
*
* dns_strerror() returns static English string descriptions of all known
* errors, and punts the remainder to strerror(3).
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#define DNS_EBASE -(('d' << 24) | ('n' << 16) | ('s' << 8) | 64)
#define dns_error_t int /* for documentation only */
enum dns_errno {
DNS_ENOBUFS = DNS_EBASE,
DNS_EILLEGAL,
DNS_EORDER,
DNS_ESECTION,
DNS_EUNKNOWN,
DNS_EADDRESS,
DNS_ENOQUERY,
DNS_ENOANSWER,
DNS_EFETCHED,
DNS_ESERVICE, /* EAI_SERVICE */
DNS_ENONAME, /* EAI_NONAME */
DNS_EFAIL, /* EAI_FAIL */
DNS_ECONNFIN,
DNS_EVERIFY,
DNS_ELAST,
}; /* dns_errno */
DNS_PUBLIC const char *dns_strerror(dns_error_t);
DNS_PUBLIC int *dns_debug_p(void);
#define dns_debug (*dns_debug_p()) /* was extern int dns_debug before 20160523 API */
/*
* C O M P I L E R A N N O T A T I O N S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#if defined __clang__
#define DNS_PRAGMA_PUSH _Pragma("clang diagnostic push")
#define DNS_PRAGMA_QUIET _Pragma("clang diagnostic ignored \"-Winitializer-overrides\"")
#define DNS_PRAGMA_POP _Pragma("clang diagnostic pop")
#elif (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) || __GNUC__ > 4
#define DNS_PRAGMA_PUSH _Pragma("GCC diagnostic push")
#define DNS_PRAGMA_QUIET _Pragma("GCC diagnostic ignored \"-Woverride-init\"")
#define DNS_PRAGMA_POP _Pragma("GCC diagnostic pop")
#else
#define DNS_PRAGMA_PUSH
#define DNS_PRAGMA_QUIET
#define DNS_PRAGMA_POP
#endif
#if defined __GNUC__
#define DNS_PRAGMA_EXTENSION __extension__
#else
#define DNS_PRAGMA_EXTENSION
#endif
/*
* E V E N T S I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#if defined(POLLIN)
#define DNS_POLLIN POLLIN
#else
#define DNS_POLLIN 1
#endif
#if defined(POLLOUT)
#define DNS_POLLOUT POLLOUT
#else
#define DNS_POLLOUT 2
#endif
/*
* See Application Interface below for configuring libevent bitmasks instead
* of poll(2) bitmasks.
*/
#define DNS_EVREAD 2
#define DNS_EVWRITE 4
#define DNS_POLL2EV(set) \
(((set) & DNS_POLLIN)? DNS_EVREAD : 0) | (((set) & DNS_POLLOUT)? DNS_EVWRITE : 0)
#define DNS_EV2POLL(set) \
(((set) & DNS_EVREAD)? DNS_POLLIN : 0) | (((set) & DNS_EVWRITE)? DNS_POLLOUT : 0)
/*
* E N U M E R A T I O N I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
enum dns_section {
DNS_S_QD = 0x01,
#define DNS_S_QUESTION DNS_S_QD
DNS_S_AN = 0x02,
#define DNS_S_ANSWER DNS_S_AN
DNS_S_NS = 0x04,
#define DNS_S_AUTHORITY DNS_S_NS
DNS_S_AR = 0x08,
#define DNS_S_ADDITIONAL DNS_S_AR
DNS_S_ALL = 0x0f
}; /* enum dns_section */
enum dns_class {
DNS_C_IN = 1,
DNS_C_ANY = 255
}; /* enum dns_class */
enum dns_type {
DNS_T_A = 1,
DNS_T_NS = 2,
DNS_T_CNAME = 5,
DNS_T_SOA = 6,
DNS_T_PTR = 12,
DNS_T_MX = 15,
DNS_T_TXT = 16,
DNS_T_AAAA = 28,
DNS_T_SRV = 33,
DNS_T_OPT = 41,
DNS_T_SSHFP = 44,
DNS_T_SPF = 99,
DNS_T_AXFR = 252,
DNS_T_ALL = 255
}; /* enum dns_type */
enum dns_opcode {
DNS_OP_QUERY = 0,
DNS_OP_IQUERY = 1,
DNS_OP_STATUS = 2,
DNS_OP_NOTIFY = 4,
DNS_OP_UPDATE = 5,
}; /* dns_opcode */
enum dns_rcode {
DNS_RC_NOERROR = 0,
DNS_RC_FORMERR = 1,
DNS_RC_SERVFAIL = 2,
DNS_RC_NXDOMAIN = 3,
DNS_RC_NOTIMP = 4,
DNS_RC_REFUSED = 5,
DNS_RC_YXDOMAIN = 6,
DNS_RC_YXRRSET = 7,
DNS_RC_NXRRSET = 8,
DNS_RC_NOTAUTH = 9,
DNS_RC_NOTZONE = 10,
/* EDNS(0) extended RCODEs */
DNS_RC_BADVERS = 16,
}; /* dns_rcode */
/*
* NOTE: These string functions need a small buffer in case the literal
* integer value needs to be printed and returned. UNLESS this buffer is
* SPECIFIED, the returned string has ONLY BLOCK SCOPE.
*/
#define DNS_STRMAXLEN 47 /* "QUESTION|ANSWER|AUTHORITY|ADDITIONAL" */
DNS_PUBLIC const char *dns_strsection(enum dns_section, char *);
DNS_PUBLIC enum dns_section dns_isection(const char *);
DNS_PUBLIC const char *dns_strclass(enum dns_class, char *);
DNS_PUBLIC enum dns_class dns_iclass(const char *);
DNS_PUBLIC const char *dns_strtype(enum dns_type, char *);
DNS_PUBLIC enum dns_type dns_itype(const char *);
DNS_PUBLIC const char *dns_stropcode(enum dns_opcode);
DNS_PUBLIC enum dns_opcode dns_iopcode(const char *);
DNS_PUBLIC const char *dns_strrcode(enum dns_rcode);
DNS_PUBLIC enum dns_rcode dns_ircode(const char *);
/*
* A T O M I C I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
typedef unsigned long dns_atomic_t;
typedef unsigned long dns_refcount_t; /* must be same value type as dns_atomic_t */
/*
* C R Y P T O I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
typedef unsigned dns_random_f(void);
DNS_PUBLIC dns_random_f **dns_random_p(void);
#define dns_random (*dns_random_p()) /* was extern unsigned (*dns_random)(void) before 20160523 API */
/*
* P A C K E T I N T E R F A C E
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct dns_header {
unsigned qid:16;
#if (defined BYTE_ORDER && BYTE_ORDER == BIG_ENDIAN) || (defined __sun && defined _BIG_ENDIAN)
unsigned qr:1;
unsigned opcode:4;
unsigned aa:1;
unsigned tc:1;
unsigned rd:1;
unsigned ra:1;
unsigned unused:3;
unsigned rcode:4;
#else
unsigned rd:1;
unsigned tc:1;
unsigned aa:1;
unsigned opcode:4;
unsigned qr:1;
unsigned rcode:4;
unsigned unused:3;
unsigned ra:1;
#endif
unsigned qdcount:16;
unsigned ancount:16;
unsigned nscount:16;
unsigned arcount:16;
}; /* struct dns_header */
#define dns_header(p) (&(p)->header)
#ifndef DNS_P_QBUFSIZ
#define DNS_P_QBUFSIZ dns_p_calcsize(256 + 4)
#endif
#ifndef DNS_P_DICTSIZE
#define DNS_P_DICTSIZE 16
#endif
struct dns_packet {
unsigned short dict[DNS_P_DICTSIZE];
struct dns_p_memo {
struct dns_s_memo {
unsigned short base, end;
} qd, an, ns, ar;
struct {
unsigned short p;
unsigned short maxudp;
unsigned ttl;
} opt;
} memo;
struct { struct dns_packet *cqe_next, *cqe_prev; } cqe;
size_t size, end;
int:16; /* tcp padding */
DNS_PRAGMA_EXTENSION union {
struct dns_header header;
unsigned char data[1];
};
}; /* struct dns_packet */
#define dns_p_calcsize(n) (offsetof(struct dns_packet, data) + DNS_PP_MAX(12, (n)))
#define dns_p_sizeof(P) dns_p_calcsize((P)->end)
/** takes size of entire packet structure as allocated */
DNS_PUBLIC struct dns_packet *dns_p_init(struct dns_packet *, size_t);
/** takes size of maximum desired payload */
DNS_PUBLIC struct dns_packet *dns_p_make(size_t, int *);
DNS_PUBLIC int dns_p_grow(struct dns_packet **);
DNS_PUBLIC struct dns_packet *dns_p_copy(struct dns_packet *, const struct dns_packet *);
#define dns_p_opcode(P) (dns_header(P)->opcode)
DNS_PUBLIC enum dns_rcode dns_p_rcode(struct dns_packet *);
DNS_PUBLIC unsigned dns_p_count(struct dns_packet *, enum dns_section);
DNS_PUBLIC int dns_p_push(struct dns_packet *, enum dns_section, const void *, size_t, enum dns_type, enum dns_class, unsigned, const void *);
DNS_PUBLIC void dns_p_dictadd(struct dns_packet *, unsigned short);
DNS_PUBLIC struct dns_packet *dns_p_merge(struct dns_packet *, enum dns_section, struct dns_packet *, enum dns_section, int *);
DNS_PUBLIC void dns_p_dump(struct dns_packet *, FILE *);
DNS_PUBLIC int dns_p_study(struct dns_packet *);
/*
* D O M A I N N A M E I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#define DNS_D_MAXLABEL 63 /* + 1 '\0' */
#define DNS_D_MAXNAME 255 /* + 1 '\0' */
#define DNS_D_ANCHOR 1 /* anchor domain w/ root "." */
#define DNS_D_CLEAVE 2 /* cleave sub-domain */
#define DNS_D_TRIM 4 /* remove superfluous dots */
DNS_PUBLIC char *dns_d_init(void *, size_t, const void *, size_t, int);
DNS_PUBLIC size_t dns_d_anchor(void *, size_t, const void *, size_t);
DNS_PUBLIC size_t dns_d_cleave(void *, size_t, const void *, size_t);
DNS_PUBLIC size_t dns_d_comp(void *, size_t, const void *, size_t, struct dns_packet *, int *);
DNS_PUBLIC size_t dns_d_expand(void *, size_t, unsigned short, struct dns_packet *, int *);
DNS_PUBLIC unsigned short dns_d_skip(unsigned short, struct dns_packet *);
DNS_PUBLIC int dns_d_push(struct dns_packet *, const void *, size_t);
DNS_PUBLIC size_t dns_d_cname(void *, size_t, const void *, size_t, struct dns_packet *, int *error);
/*
* R E S O U R C E R E C O R D I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct dns_rr {
enum dns_section section;
struct {
unsigned short p;
unsigned short len;
} dn;
enum dns_type type;
enum dns_class class;
unsigned ttl;
struct {
unsigned short p;
unsigned short len;
} rd;
}; /* struct dns_rr */
DNS_PUBLIC int dns_rr_copy(struct dns_packet *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_rr_parse(struct dns_rr *, unsigned short, struct dns_packet *);
DNS_PUBLIC unsigned short dns_rr_skip(unsigned short, struct dns_packet *);
DNS_PUBLIC int dns_rr_cmp(struct dns_rr *, struct dns_packet *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC size_t dns_rr_print(void *, size_t, struct dns_rr *, struct dns_packet *, int *);
struct dns_rr_i {
enum dns_section section;
const void *name;
enum dns_type type;
enum dns_class class;
const void *data;
int follow;
int (*sort)(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *);
unsigned args[2];
struct {
unsigned short next;
unsigned short count;
unsigned exec;
unsigned regs[2];
} state, saved;
}; /* struct dns_rr_i */
DNS_PUBLIC int dns_rr_i_packet(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *);
DNS_PUBLIC int dns_rr_i_order(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *);
DNS_PUBLIC int dns_rr_i_shuffle(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *);
DNS_PUBLIC void dns_rr_i_init(struct dns_rr_i *);
#define dns_rr_i_save(i) ((i)->saved = (i)->state)
#define dns_rr_i_rewind(i) ((i)->state = (i)->saved)
#define dns_rr_i_count(i) ((i)->state.count)
DNS_PUBLIC unsigned dns_rr_grep(struct dns_rr *, unsigned, struct dns_rr_i *, struct dns_packet *, int *);
#define dns_rr_foreach_(rr, P, ...) \
for (struct dns_rr_i DNS_PP_XPASTE(i, __LINE__) = { __VA_ARGS__ }; dns_rr_grep((rr), 1, &DNS_PP_XPASTE(i, __LINE__), (P), NULL); )
#define dns_rr_foreach(...) dns_rr_foreach_(__VA_ARGS__)
/*
* A R E S O U R C E R E C O R D
*/
struct dns_a {
struct in_addr addr;
}; /* struct dns_a */
DNS_PUBLIC int dns_a_parse(struct dns_a *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_a_push(struct dns_packet *, struct dns_a *);
DNS_PUBLIC int dns_a_cmp(const struct dns_a *, const struct dns_a *);
DNS_PUBLIC size_t dns_a_print(void *, size_t, struct dns_a *);
DNS_PUBLIC size_t dns_a_arpa(void *, size_t, const struct dns_a *);
/*
* AAAA R E S O U R C E R E C O R D
*/
struct dns_aaaa {
struct in6_addr addr;
}; /* struct dns_aaaa */
DNS_PUBLIC int dns_aaaa_parse(struct dns_aaaa *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_aaaa_push(struct dns_packet *, struct dns_aaaa *);
DNS_PUBLIC int dns_aaaa_cmp(const struct dns_aaaa *, const struct dns_aaaa *);
DNS_PUBLIC size_t dns_aaaa_print(void *, size_t, struct dns_aaaa *);
DNS_PUBLIC size_t dns_aaaa_arpa(void *, size_t, const struct dns_aaaa *);
/*
* MX R E S O U R C E R E C O R D
*/
struct dns_mx {
unsigned short preference;
char host[DNS_D_MAXNAME + 1];
}; /* struct dns_mx */
DNS_PUBLIC int dns_mx_parse(struct dns_mx *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_mx_push(struct dns_packet *, struct dns_mx *);
DNS_PUBLIC int dns_mx_cmp(const struct dns_mx *, const struct dns_mx *);
DNS_PUBLIC size_t dns_mx_print(void *, size_t, struct dns_mx *);
DNS_PUBLIC size_t dns_mx_cname(void *, size_t, struct dns_mx *);
/*
* NS R E S O U R C E R E C O R D
*/
struct dns_ns {
char host[DNS_D_MAXNAME + 1];
}; /* struct dns_ns */
DNS_PUBLIC int dns_ns_parse(struct dns_ns *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_ns_push(struct dns_packet *, struct dns_ns *);
DNS_PUBLIC int dns_ns_cmp(const struct dns_ns *, const struct dns_ns *);
DNS_PUBLIC size_t dns_ns_print(void *, size_t, struct dns_ns *);
DNS_PUBLIC size_t dns_ns_cname(void *, size_t, struct dns_ns *);
/*
* CNAME R E S O U R C E R E C O R D
*/
struct dns_cname {
char host[DNS_D_MAXNAME + 1];
}; /* struct dns_cname */
DNS_PUBLIC int dns_cname_parse(struct dns_cname *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_cname_push(struct dns_packet *, struct dns_cname *);
DNS_PUBLIC int dns_cname_cmp(const struct dns_cname *, const struct dns_cname *);
DNS_PUBLIC size_t dns_cname_print(void *, size_t, struct dns_cname *);
DNS_PUBLIC size_t dns_cname_cname(void *, size_t, struct dns_cname *);
/*
* SOA R E S O U R C E R E C O R D
*/
struct dns_soa {
char mname[DNS_D_MAXNAME + 1];
char rname[DNS_D_MAXNAME + 1];
unsigned serial, refresh, retry, expire, minimum;
}; /* struct dns_soa */
DNS_PUBLIC int dns_soa_parse(struct dns_soa *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_soa_push(struct dns_packet *, struct dns_soa *);
DNS_PUBLIC int dns_soa_cmp(const struct dns_soa *, const struct dns_soa *);
DNS_PUBLIC size_t dns_soa_print(void *, size_t, struct dns_soa *);
/*
* PTR R E S O U R C E R E C O R D
*/
struct dns_ptr {
char host[DNS_D_MAXNAME + 1];
}; /* struct dns_ptr */
DNS_PUBLIC int dns_ptr_parse(struct dns_ptr *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_ptr_push(struct dns_packet *, struct dns_ptr *);
DNS_PUBLIC int dns_ptr_cmp(const struct dns_ptr *, const struct dns_ptr *);
DNS_PUBLIC size_t dns_ptr_print(void *, size_t, struct dns_ptr *);
DNS_PUBLIC size_t dns_ptr_cname(void *, size_t, struct dns_ptr *);
DNS_PUBLIC size_t dns_ptr_qname(void *, size_t, int, void *);
/*
* SRV R E S O U R C E R E C O R D
*/
struct dns_srv {
unsigned short priority;
unsigned short weight;
unsigned short port;
char target[DNS_D_MAXNAME + 1];
}; /* struct dns_srv */
DNS_PUBLIC int dns_srv_parse(struct dns_srv *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_srv_push(struct dns_packet *, struct dns_srv *);
DNS_PUBLIC int dns_srv_cmp(const struct dns_srv *, const struct dns_srv *);
DNS_PUBLIC size_t dns_srv_print(void *, size_t, struct dns_srv *);
DNS_PUBLIC size_t dns_srv_cname(void *, size_t, struct dns_srv *);
/*
* OPT R E S O U R C E R E C O R D
*/
#ifndef DNS_OPT_MINDATA
#define DNS_OPT_MINDATA 256
#endif
#define DNS_OPT_DNSSEC 0x8000
struct dns_opt {
enum dns_rcode rcode;
unsigned char version;
unsigned short flags;
union {
unsigned short maxsize; /* deprecated as confusing */
unsigned short maxudp; /* maximum UDP payload size */
};
size_t size, len;
unsigned char data[DNS_OPT_MINDATA];
}; /* struct dns_opt */
#define DNS_OPT_INIT(opt) { .size = sizeof (*opt) - offsetof(struct dns_opt, data) }
DNS_PUBLIC struct dns_opt *dns_opt_init(struct dns_opt *, size_t);
DNS_PUBLIC int dns_opt_parse(struct dns_opt *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_opt_push(struct dns_packet *, struct dns_opt *);
DNS_PUBLIC int dns_opt_cmp(const struct dns_opt *, const struct dns_opt *);
DNS_PUBLIC size_t dns_opt_print(void *, size_t, struct dns_opt *);
DNS_PUBLIC unsigned int dns_opt_ttl(const struct dns_opt *);
DNS_PUBLIC unsigned short dns_opt_class(const struct dns_opt *);
DNS_PUBLIC dns_error_t dns_opt_data_push(struct dns_opt *, unsigned char, unsigned short, const void *);
/*
* SSHFP R E S O U R C E R E C O R D
*/
struct dns_sshfp {
enum dns_sshfp_key {
DNS_SSHFP_RSA = 1,
DNS_SSHFP_DSA = 2,
} algo;
enum dns_sshfp_digest {
DNS_SSHFP_SHA1 = 1,
} type;
union {
unsigned char sha1[20];
} digest;
}; /* struct dns_sshfp */
DNS_PUBLIC int dns_sshfp_parse(struct dns_sshfp *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_sshfp_push(struct dns_packet *, struct dns_sshfp *);
DNS_PUBLIC int dns_sshfp_cmp(const struct dns_sshfp *, const struct dns_sshfp *);
DNS_PUBLIC size_t dns_sshfp_print(void *, size_t, struct dns_sshfp *);
/*
* TXT R E S O U R C E R E C O R D
*/
#ifndef DNS_TXT_MINDATA
#define DNS_TXT_MINDATA 1024
#endif
struct dns_txt {
size_t size, len;
unsigned char data[DNS_TXT_MINDATA];
}; /* struct dns_txt */
DNS_PUBLIC struct dns_txt *dns_txt_init(struct dns_txt *, size_t);
DNS_PUBLIC int dns_txt_parse(struct dns_txt *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_txt_push(struct dns_packet *, struct dns_txt *);
DNS_PUBLIC int dns_txt_cmp(const struct dns_txt *, const struct dns_txt *);
DNS_PUBLIC size_t dns_txt_print(void *, size_t, struct dns_txt *);
/*
* ANY R E S O U R C E R E C O R D
*/
union dns_any {
struct dns_a a;
struct dns_aaaa aaaa;
struct dns_mx mx;
struct dns_ns ns;
struct dns_cname cname;
struct dns_soa soa;
struct dns_ptr ptr;
struct dns_srv srv;
struct dns_opt opt;
struct dns_sshfp sshfp;
struct dns_txt txt, spf, rdata;
}; /* union dns_any */
#define DNS_ANY_INIT(any) { .rdata = { .size = sizeof *(any) - offsetof(struct dns_txt, data) } }
DNS_PUBLIC union dns_any *dns_any_init(union dns_any *, size_t);
DNS_PUBLIC int dns_any_parse(union dns_any *, struct dns_rr *, struct dns_packet *);
DNS_PUBLIC int dns_any_push(struct dns_packet *, union dns_any *, enum dns_type);
DNS_PUBLIC int dns_any_cmp(const union dns_any *, enum dns_type, const union dns_any *, enum dns_type);
DNS_PUBLIC size_t dns_any_print(void *, size_t, union dns_any *, enum dns_type);
DNS_PUBLIC size_t dns_any_cname(void *, size_t, union dns_any *, enum dns_type);
/*
* H O S T S I N T E R F A C E
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct dns_hosts;
DNS_PUBLIC struct dns_hosts *dns_hosts_open(int *);
DNS_PUBLIC void dns_hosts_close(struct dns_hosts *);
DNS_PUBLIC dns_refcount_t dns_hosts_acquire(struct dns_hosts *);
DNS_PUBLIC dns_refcount_t dns_hosts_release(struct dns_hosts *);
DNS_PUBLIC struct dns_hosts *dns_hosts_mortal(struct dns_hosts *);
DNS_PUBLIC struct dns_hosts *dns_hosts_local(int *);
DNS_PUBLIC int dns_hosts_loadfile(struct dns_hosts *, FILE *);
DNS_PUBLIC int dns_hosts_loadpath(struct dns_hosts *, const char *);
DNS_PUBLIC int dns_hosts_dump(struct dns_hosts *, FILE *);
DNS_PUBLIC int dns_hosts_insert(struct dns_hosts *, int, const void *, const void *, _Bool);
DNS_PUBLIC struct dns_packet *dns_hosts_query(struct dns_hosts *, struct dns_packet *, int *);
/*
* R E S O L V . C O N F I N T E R F A C E
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct dns_resolv_conf {
struct sockaddr_storage nameserver[3];
char search[4][DNS_D_MAXNAME + 1];
/* (f)ile, (b)ind, (c)ache */
char lookup[4 * (1 + (4 * 2))];
/* getaddrinfo family by preference order ("inet4", "inet6") */
int family[3];
struct {
_Bool edns0;
unsigned ndots;
unsigned timeout;
unsigned attempts;
_Bool rotate;
_Bool recurse;
_Bool smart;
enum {
DNS_RESCONF_TCP_ENABLE,
DNS_RESCONF_TCP_ONLY,
DNS_RESCONF_TCP_SOCKS,
DNS_RESCONF_TCP_DISABLE,
} tcp;
} options;
struct sockaddr_storage iface;
struct { /* PRIVATE */
dns_atomic_t refcount;
} _;
}; /* struct dns_resolv_conf */
DNS_PUBLIC struct dns_resolv_conf *dns_resconf_open(int *);
DNS_PUBLIC void dns_resconf_close(struct dns_resolv_conf *);
DNS_PUBLIC dns_refcount_t dns_resconf_acquire(struct dns_resolv_conf *);
DNS_PUBLIC dns_refcount_t dns_resconf_release(struct dns_resolv_conf *);
DNS_PUBLIC struct dns_resolv_conf *dns_resconf_mortal(struct dns_resolv_conf *);
DNS_PUBLIC struct dns_resolv_conf *dns_resconf_local(int *);
DNS_PUBLIC struct dns_resolv_conf *dns_resconf_root(int *);
DNS_PUBLIC int dns_resconf_pton(struct sockaddr_storage *, const char *);
DNS_PUBLIC int dns_resconf_loadfile(struct dns_resolv_conf *, FILE *);
DNS_PUBLIC int dns_resconf_loadpath(struct dns_resolv_conf *, const char *);
DNS_PUBLIC int dns_nssconf_loadfile(struct dns_resolv_conf *, FILE *);
DNS_PUBLIC int dns_nssconf_loadpath(struct dns_resolv_conf *, const char *);
DNS_PUBLIC int dns_resconf_dump(struct dns_resolv_conf *, FILE *);
DNS_PUBLIC int dns_nssconf_dump(struct dns_resolv_conf *, FILE *);
DNS_PUBLIC int dns_resconf_setiface(struct dns_resolv_conf *, const char *, unsigned short);
typedef unsigned long dns_resconf_i_t;
DNS_PUBLIC size_t dns_resconf_search(void *, size_t, const void *, size_t, struct dns_resolv_conf *, dns_resconf_i_t *);
/*
* H I N T S E R V E R I N T E R F A C E
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct dns_hints;
DNS_PUBLIC struct dns_hints *dns_hints_open(struct dns_resolv_conf *, int *);
DNS_PUBLIC void dns_hints_close(struct dns_hints *);
DNS_PUBLIC dns_refcount_t dns_hints_acquire(struct dns_hints *);
DNS_PUBLIC dns_refcount_t dns_hints_release(struct dns_hints *);
DNS_PUBLIC struct dns_hints *dns_hints_mortal(struct dns_hints *);
DNS_PUBLIC int dns_hints_insert(struct dns_hints *, const char *, const struct sockaddr *, unsigned);
DNS_PUBLIC unsigned dns_hints_insert_resconf(struct dns_hints *, const char *, const struct dns_resolv_conf *, int *);
DNS_PUBLIC struct dns_hints *dns_hints_local(struct dns_resolv_conf *, int *);
DNS_PUBLIC struct dns_hints *dns_hints_root(struct dns_resolv_conf *, int *);
DNS_PUBLIC struct dns_packet *dns_hints_query(struct dns_hints *, struct dns_packet *, int *);
DNS_PUBLIC int dns_hints_dump(struct dns_hints *, FILE *);
struct dns_hints_i {
const char *zone;
struct {
unsigned next;
unsigned seed;
} state;
}; /* struct dns_hints_i */
DNS_PUBLIC unsigned dns_hints_grep(struct sockaddr **, socklen_t *, unsigned, struct dns_hints_i *, struct dns_hints *);
/*
* C A C H E I N T E R F A C E
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct dns_cache {
void *state;
dns_refcount_t (*acquire)(struct dns_cache *);
dns_refcount_t (*release)(struct dns_cache *);
struct dns_packet *(*query)(struct dns_packet *, struct dns_cache *, int *);
int (*submit)(struct dns_packet *, struct dns_cache *);
int (*check)(struct dns_cache *);
struct dns_packet *(*fetch)(struct dns_cache *, int *);
int (*pollfd)(struct dns_cache *);
short (*events)(struct dns_cache *);
void (*clear)(struct dns_cache *);
union {
long i;
void *p;
} arg[3];
struct { /* PRIVATE */
dns_atomic_t refcount;
} _;
}; /* struct dns_cache */
DNS_PUBLIC struct dns_cache *dns_cache_init(struct dns_cache *);
DNS_PUBLIC void dns_cache_close(struct dns_cache *);
/*
* A P P L I C A T I O N I N T E R F A C E
*
* Options to change the behavior of the API. Applies across all the
* different components.
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#define DNS_OPTS_INITIALIZER_ { 0, 0 }, 0, 0
#define DNS_OPTS_INITIALIZER { DNS_OPTS_INITIALIZER_ }
struct dns_options {
/*
* If the callback closes *fd, it must set it to -1. Otherwise, the
* descriptor is queued and lazily closed at object destruction or
* by an explicit call to _clear(). This allows safe use of
* kqueue(2), epoll(2), et al -style persistent events.
*/
struct {
void *arg;
int (*cb)(int *fd, void *arg);
} closefd;
/* bitmask for _events() routines */
enum dns_events {
DNS_SYSPOLL,
DNS_LIBEVENT,
} events;
/* Use this SOCKS server. */
const struct sockaddr_storage *socks_host;
/* Credentials for the SOCKS server (optional). */
const char *socks_user;
const char *socks_password;
}; /* struct dns_options */
/*
* S T A T S I N T E R F A C E S
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct dns_stat {
size_t queries;
struct {
struct {
size_t count, bytes;
} sent, rcvd;
} udp, tcp;
}; /* struct dns_stat */
/*
* S O C K E T I N T E R F A C E
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct dns_socket;
DNS_PUBLIC struct dns_socket *dns_so_open(const struct sockaddr *, int, const struct dns_options *, int *error);