resolv/res_data.c

/*	$NetBSD: res_data.c,v 1.8 2004/06/09 18:07:03 christos Exp $	*/

/*
 * 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 <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#ifdef notdef
static const char rcsid[] = "Id: res_data.c,v 1.1.206.2 2004/03/16 12:34:18 marka Exp";
#else
__RCSID("$NetBSD: res_data.c,v 1.8 2004/06/09 18:07:03 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

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

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

#include <ctype.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "resolv_private.h"

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

#ifndef __BIND_NOSTATIC
extern struct __res_state _nres;

/* Proto. */

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

#define res_need_init() ((_nres.options & RES_INIT) == 0U)

int res_init(void) {
    int rv;
    extern int __res_vinit(res_state, int);
#ifdef COMPAT__RES
    /*
     * Compatibility with program that were accessing _res directly
     * to set options. We keep another struct res that is the same
     * size as the original res structure, and then copy fields to
     * it so that we achieve the same initialization
     */
    extern void* __res_get_old_state(void);
    extern void __res_put_old_state(void*);
    res_state ores = __res_get_old_state();

    if (ores->options != 0) _nres.options = ores->options;
    if (ores->retrans != 0) _nres.retrans = ores->retrans;
    if (ores->retry != 0) _nres.retry = ores->retry;
#endif

    /*
     * 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.
     *
     * _nres.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 (!_nres.retrans) _nres.retrans = RES_TIMEOUT;
    if (!_nres.retry) _nres.retry = 4;
    if (!(_nres.options & RES_INIT)) _nres.options = RES_DEFAULT;

    /*
     * This one used to initialize implicitly to zero, so unless the app
     * has set it to something in particular, we can randomize it now.
     */
    if (!_nres.id) _nres.id = res_randomid();

    rv = __res_vinit(&_nres, 1);
#ifdef COMPAT__RES
    __res_put_old_state(&_nres);
#endif
    return rv;
}

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) {
    if (res_need_init() && res_init() == -1) return;

    res_pquery(&_nres, 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 */
{
    if (res_need_init() && res_init() == -1) {
        RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
        return (-1);
    }
    return (res_nmkquery(&_nres, op, dname, class, type, data, datalen, newrr_in, buf, buflen));
}

#ifdef _LIBRESOLV
int res_mkupdate(ns_updrec* rrecp_in, u_char* buf, int buflen) {
    if (res_need_init() && res_init() == -1) {
        RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
        return (-1);
    }

    return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
}
#endif

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 */
{
    if (res_need_init() && res_init() == -1) {
        RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
        return (-1);
    }
    return (res_nquery(&_nres, name, class, type, answer, anslen));
}

void res_send_setqhook(res_send_qhook hook) {
    _nres.qhook = hook;
}

void res_send_setrhook(res_send_rhook hook) {
    _nres.rhook = hook;
}

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

int res_send(const u_char* buf, int buflen, u_char* ans, int anssiz) {
    if (res_need_init() && res_init() == -1) {
        /* errno should have been set by res_init() in this case. */
        return (-1);
    }

    return (res_nsend(&_nres, buf, buflen, ans, anssiz));
}

#ifdef _LIBRESOLV
int res_sendsigned(const u_char* buf, int buflen, ns_tsig_key* key, u_char* ans, int anssiz) {
    if (res_need_init() && res_init() == -1) {
        /* errno should have been set by res_init() in this case. */
        return (-1);
    }

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

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

#ifdef _LIBRESOLV
int res_update(ns_updrec* rrecp_in) {
    if (res_need_init() && res_init() == -1) {
        RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
        return (-1);
    }

    return (res_nupdate(&_nres, rrecp_in, NULL));
}
#endif

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 */
{
    if (res_need_init() && res_init() == -1) {
        RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
        return (-1);
    }

    return (res_nsearch(&_nres, 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 */
{
    if (res_need_init() && res_init() == -1) {
        RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
        return (-1);
    }

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

int res_opt(int a, u_char* b, int c, int d) {
    return res_nopt(&_nres, a, b, c, d);
}

const char* hostalias(const char* name) {
    return NULL;
}

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

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

#endif