res_data.c

/*-
 * SPDX-License-Identifier: ISC
 *
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1995-1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "port_before.h"

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>

#include <ctype.h>
#include <netdb.h>
#include <resolv.h>
#include <res_update.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "port_after.h"

const char *_res_opcodes[] = {
	"QUERY",
	"IQUERY",
	"CQUERYM",
	"CQUERYU",	/*%< experimental */
	"NOTIFY",	/*%< experimental */
	"UPDATE",
	"6",
	"7",
	"8",
	"9",
	"10",
	"11",
	"12",
	"13",
	"ZONEINIT",
	"ZONEREF",
};

#ifdef BIND_UPDATE
const char *_res_sectioncodes[] = {
	"ZONE",
	"PREREQUISITES",
	"UPDATE",
	"ADDITIONAL",
};
#endif

#ifndef __BIND_NOSTATIC

/* Proto. */

int  res_ourserver_p(const res_state, const struct sockaddr_in *);

__noinline int
res_init(void) {
	extern int __res_vinit(res_state, int);
	res_state statp = &_res;

	/*
	 * These three fields used to be statically initialized.  This made
	 * it hard to use this code in a shared library.  It is necessary,
	 * now that we're doing dynamic initialization here, that we preserve
	 * the old semantics: if an application modifies one of these three
	 * fields of _res before res_init() is called, res_init() will not
	 * alter them.  Of course, if an application is setting them to
	 * _zero_ before calling res_init(), hoping to override what used
	 * to be the static default, we can't detect it and unexpected results
	 * will follow.  Zero for any of these fields would make no sense,
	 * so one can safely assume that the applications were already getting
	 * unexpected results.
	 *
	 * _res.options is tricky since some apps were known to diddle the bits
	 * before res_init() was first called. We can't replicate that semantic
	 * with dynamic initialization (they may have turned bits off that are
	 * set in RES_DEFAULT).  Our solution is to declare such applications
	 * "broken".  They could fool us by setting RES_INIT but none do (yet).
	 */
	if (!statp->retrans)
		statp->retrans = RES_TIMEOUT;
	if (!statp->retry)
		statp->retry = RES_DFLRETRY;
	if (!(statp->options & RES_INIT))
		statp->options = RES_DEFAULT;

	return (__res_vinit(statp, 1));
}

void
p_query(const u_char *msg) {
	fp_query(msg, stdout);
}

void
fp_query(const u_char *msg, FILE *file) {
	fp_nquery(msg, PACKETSZ, file);
}

void
fp_nquery(const u_char *msg, int len, FILE *file) {
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1)
		return;

	res_pquery(statp, msg, len, file);
}

int
res_mkquery(int op,			/*!< opcode of query  */
	    const char *dname,		/*!< domain name  */
	    int class, int type,	/*!< class and type of query  */
	    const u_char *data,		/*!< resource record data  */
	    int datalen,		/*!< length of data  */
	    const u_char *newrr_in,	/*!< new rr for modify or append  */
	    u_char *buf,		/*!< buffer to put query  */
	    int buflen)			/*!< size of buffer  */
{
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
		return (-1);
	}
	return (res_nmkquery(statp, op, dname, class, type,
			     data, datalen,
			     newrr_in, buf, buflen));
}

int
res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
		return (-1);
	}

	return (res_nmkupdate(statp, rrecp_in, buf, buflen));
}

int
res_query(const char *name,	/*!< domain name  */
	  int class, int type,	/*!< class and type of query  */
	  u_char *answer,	/*!< buffer to put answer  */
	  int anslen)		/*!< size of answer buffer  */
{
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
		return (-1);
	}
	return (res_nquery(statp, name, class, type, answer, anslen));
}

#ifndef _LIBC
void
res_send_setqhook(res_send_qhook hook) {
	_res.qhook = hook;
}

void
res_send_setrhook(res_send_rhook hook) {
	_res.rhook = hook;
}
#endif

int
res_isourserver(const struct sockaddr_in *inp) {
	return (res_ourserver_p(&_res, inp));
}

int
res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		/* errno should have been set by res_init() in this case. */
		return (-1);
	}

	return (res_nsend(statp, buf, buflen, ans, anssiz));
}

#ifndef _LIBC
int
res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
	       u_char *ans, int anssiz)
{
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		/* errno should have been set by res_init() in this case. */
		return (-1);
	}

	return (res_nsendsigned(statp, buf, buflen, key, ans, anssiz));
}
#endif

void
res_close(void) {
	res_nclose(&_res);
}

int
res_update(ns_updrec *rrecp_in) {
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
		return (-1);
	}

	return (res_nupdate(statp, rrecp_in, NULL));
}

int
res_search(const char *name,	/*!< domain name  */
	   int class, int type,	/*!< class and type of query  */
	   u_char *answer,	/*!< buffer to put answer  */
	   int anslen)		/*!< size of answer  */
{
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
		return (-1);
	}

	return (res_nsearch(statp, name, class, type, answer, anslen));
}

int
res_querydomain(const char *name,
		const char *domain,
		int class, int type,	/*!< class and type of query  */
		u_char *answer,		/*!< buffer to put answer  */
		int anslen)		/*!< size of answer  */
{
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
		return (-1);
	}

	return (res_nquerydomain(statp, name, domain,
				 class, type,
				 answer, anslen));
}

u_int
res_randomid(void) {
	res_state statp = &_res;
	if ((statp->options & RES_INIT) == 0U && res_init() == -1) {
		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
		return (-1);
	}

	return (res_nrandomid(statp));
}

int
res_opt(int n0, u_char *buf, int buflen, int anslen)
{
	return (res_nopt(&_res, n0, buf, buflen, anslen));
}

const char *
hostalias(const char *name) {
	static char abuf[MAXDNAME];

	return (res_hostalias(&_res, name, abuf, sizeof abuf));
}

#ifdef ultrix
int
local_hostname_length(const char *hostname) {
	int len_host, len_domain;
	res_state statp;

	statp = &_res;
	if (!*statp->defdname)
		res_init();
	len_host = strlen(hostname);
	len_domain = strlen(statp->defdname);
	if (len_host > len_domain &&
	    !strcasecmp(hostname + len_host - len_domain, statp->defdname) &&
	    hostname[len_host - len_domain - 1] == '.')
		return (len_host - len_domain - 1);
	return (0);
}
#endif /*ultrix*/

/*
 * Weak aliases for applications that use certain private entry points,
 * and fail to include <resolv.h>.
 */
#undef res_init
__weak_reference(__res_init, res_init);
#undef p_query
__weak_reference(__p_query, p_query);
#undef res_mkquery
__weak_reference(__res_mkquery, res_mkquery);
#undef res_query
__weak_reference(__res_query, res_query);
#undef res_send
__weak_reference(__res_send, res_send);
#undef res_close
__weak_reference(__res_close, _res_close);
#undef res_search
__weak_reference(__res_search, res_search);
#undef res_querydomain
__weak_reference(__res_querydomain, res_querydomain);

#endif

/*! \file */