NetBSD-5.0.2/crypto/dist/ssh/getrrsetbyname.c
/* $NetBSD: getrrsetbyname.c,v 1.3 2006/09/28 21:22:14 christos Exp $ */
/* $OpenBSD: getrrsetbyname.c,v 1.10 2005/03/30 02:58:28 tedu Exp $ */
/*
* Copyright (c) 2001 Jakob Schlyter. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Portions Copyright (c) 1999-2001 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 INTERNET SOFTWARE CONSORTIUM
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
* INTERNET SOFTWARE CONSORTIUM 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.
*/
/* OPENBSD ORIGINAL: lib/libc/net/getrrsetbyname.c */
#include "includes.h"
__RCSID("$NetBSD: getrrsetbyname.c,v 1.3 2006/09/28 21:22:14 christos Exp $");
#ifndef HAVE_GETRRSETBYNAME
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "getrrsetbyname.h"
#if defined(HAVE_DECL_H_ERRNO) && !HAVE_DECL_H_ERRNO
extern int h_errno;
#endif
/* We don't need multithread support here */
#ifdef _THREAD_PRIVATE
# undef _THREAD_PRIVATE
#endif
#define _THREAD_PRIVATE(a,b,c) (c)
#ifndef __NetBSD__
struct __res_state _res;
#else
#define HAVE__GETSHORT
#define HAVE__GETLONG
#endif
/* Necessary functions and macros */
/*
* Inline versions of get/put short/long. Pointer is advanced.
*
* These macros demonstrate the property of C whereby it can be
* portable or it can be elegant but rarely both.
*/
#ifndef INT32SZ
# define INT32SZ 4
#endif
#ifndef INT16SZ
# define INT16SZ 2
#endif
#ifndef GETSHORT
#define GETSHORT(s, cp) { \
register u_char *t_cp = (u_char *)(cp); \
(s) = ((u_int16_t)t_cp[0] << 8) \
| ((u_int16_t)t_cp[1]) \
; \
(cp) += INT16SZ; \
}
#endif
#ifndef GETLONG
#define GETLONG(l, cp) { \
register u_char *t_cp = (u_char *)(cp); \
(l) = ((u_int32_t)t_cp[0] << 24) \
| ((u_int32_t)t_cp[1] << 16) \
| ((u_int32_t)t_cp[2] << 8) \
| ((u_int32_t)t_cp[3]) \
; \
(cp) += INT32SZ; \
}
#endif
/*
* Routines to insert/extract short/long's.
*/
#ifndef HAVE__GETSHORT
static u_int16_t
_getshort(msgp)
register const u_char *msgp;
{
register u_int16_t u;
GETSHORT(u, msgp);
return (u);
}
#elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
u_int16_t _getshort(register const u_char *);
#endif
#ifndef HAVE__GETLONG
static u_int32_t
_getlong(msgp)
register const u_char *msgp;
{
register u_int32_t u;
GETLONG(u, msgp);
return (u);
}
#elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
u_int32_t _getlong(register const u_char *);
#endif
/* ************** */
#define ANSWER_BUFFER_SIZE 1024*64
struct dns_query {
char *name;
u_int16_t type;
u_int16_t class;
struct dns_query *next;
};
struct dns_rr {
char *name;
u_int16_t type;
u_int16_t class;
u_int16_t ttl;
u_int16_t size;
void *rdata;
struct dns_rr *next;
};
struct dns_response {
HEADER header;
struct dns_query *query;
struct dns_rr *answer;
struct dns_rr *authority;
struct dns_rr *additional;
};
static struct dns_response *parse_dns_response(const u_char *, int);
static struct dns_query *parse_dns_qsection(const u_char *, int,
const u_char **, int);
static struct dns_rr *parse_dns_rrsection(const u_char *, int, const u_char **,
int);
static void free_dns_query(struct dns_query *);
static void free_dns_rr(struct dns_rr *);
static void free_dns_response(struct dns_response *);
static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
int
getrrsetbyname(const char *hostname, unsigned int rdclass,
unsigned int rdtype, unsigned int flags,
struct rrsetinfo **res)
{
struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
int result;
struct rrsetinfo *rrset = NULL;
struct dns_response *response = NULL;
struct dns_rr *rr;
struct rdatainfo *rdata;
int length;
unsigned int index_ans, index_sig;
u_char answer[ANSWER_BUFFER_SIZE];
/* check for invalid class and type */
if (rdclass > 0xffff || rdtype > 0xffff) {
result = ERRSET_INVAL;
goto fail;
}
/* don't allow queries of class or type ANY */
if (rdclass == 0xff || rdtype == 0xff) {
result = ERRSET_INVAL;
goto fail;
}
/* don't allow flags yet, unimplemented */
if (flags) {
result = ERRSET_INVAL;
goto fail;
}
/* initialize resolver */
if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
result = ERRSET_FAIL;
goto fail;
}
#ifdef DEBUG
_resp->options |= RES_DEBUG;
#endif /* DEBUG */
#ifdef RES_USE_DNSSEC
/* turn on DNSSEC if EDNS0 is configured */
if (_resp->options & RES_USE_EDNS0)
_resp->options |= RES_USE_DNSSEC;
#endif /* RES_USE_DNSEC */
/* make query */
length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
answer, sizeof(answer));
if (length < 0) {
switch(h_errno) {
case HOST_NOT_FOUND:
result = ERRSET_NONAME;
goto fail;
case NO_DATA:
result = ERRSET_NODATA;
goto fail;
default:
result = ERRSET_FAIL;
goto fail;
}
}
/* parse result */
response = parse_dns_response(answer, length);
if (response == NULL) {
result = ERRSET_FAIL;
goto fail;
}
if (response->header.qdcount != 1) {
result = ERRSET_FAIL;
goto fail;
}
/* initialize rrset */
rrset = calloc(1, sizeof(struct rrsetinfo));
if (rrset == NULL) {
result = ERRSET_NOMEMORY;
goto fail;
}
rrset->rri_rdclass = response->query->class;
rrset->rri_rdtype = response->query->type;
rrset->rri_ttl = response->answer->ttl;
rrset->rri_nrdatas = response->header.ancount;
#ifdef HAVE_HEADER_AD
/* check for authenticated data */
if (response->header.ad == 1)
rrset->rri_flags |= RRSET_VALIDATED;
#endif
/* copy name from answer section */
rrset->rri_name = strdup(response->answer->name);
if (rrset->rri_name == NULL) {
result = ERRSET_NOMEMORY;
goto fail;
}
/* count answers */
rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
rrset->rri_rdtype);
rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
T_SIG);
/* allocate memory for answers */
rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
sizeof(struct rdatainfo));
if (rrset->rri_rdatas == NULL) {
result = ERRSET_NOMEMORY;
goto fail;
}
/* allocate memory for signatures */
rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
if (rrset->rri_sigs == NULL) {
result = ERRSET_NOMEMORY;
goto fail;
}
/* copy answers & signatures */
for (rr = response->answer, index_ans = 0, index_sig = 0;
rr; rr = rr->next) {
rdata = NULL;
if (rr->class == rrset->rri_rdclass &&
rr->type == rrset->rri_rdtype)
rdata = &rrset->rri_rdatas[index_ans++];
if (rr->class == rrset->rri_rdclass &&
rr->type == T_SIG)
rdata = &rrset->rri_sigs[index_sig++];
if (rdata) {
rdata->rdi_length = rr->size;
rdata->rdi_data = malloc(rr->size);
if (rdata->rdi_data == NULL) {
result = ERRSET_NOMEMORY;
goto fail;
}
memcpy(rdata->rdi_data, rr->rdata, rr->size);
}
}
free_dns_response(response);
*res = rrset;
return (ERRSET_SUCCESS);
fail:
if (rrset != NULL)
freerrset(rrset);
if (response != NULL)
free_dns_response(response);
return (result);
}
void
freerrset(struct rrsetinfo *rrset)
{
u_int16_t i;
if (rrset == NULL)
return;
if (rrset->rri_rdatas) {
for (i = 0; i < rrset->rri_nrdatas; i++) {
if (rrset->rri_rdatas[i].rdi_data == NULL)
break;
free(rrset->rri_rdatas[i].rdi_data);
}
free(rrset->rri_rdatas);
}
if (rrset->rri_sigs) {
for (i = 0; i < rrset->rri_nsigs; i++) {
if (rrset->rri_sigs[i].rdi_data == NULL)
break;
free(rrset->rri_sigs[i].rdi_data);
}
free(rrset->rri_sigs);
}
if (rrset->rri_name)
free(rrset->rri_name);
free(rrset);
}
/*
* DNS response parsing routines
*/
static struct dns_response *
parse_dns_response(const u_char *answer, int size)
{
struct dns_response *resp;
const u_char *cp;
/* allocate memory for the response */
resp = calloc(1, sizeof(*resp));
if (resp == NULL)
return (NULL);
/* initialize current pointer */
cp = answer;
/* copy header */
memcpy(&resp->header, cp, HFIXEDSZ);
cp += HFIXEDSZ;
/* fix header byte order */
resp->header.qdcount = ntohs(resp->header.qdcount);
resp->header.ancount = ntohs(resp->header.ancount);
resp->header.nscount = ntohs(resp->header.nscount);
resp->header.arcount = ntohs(resp->header.arcount);
/* there must be at least one query */
if (resp->header.qdcount < 1) {
free_dns_response(resp);
return (NULL);
}
/* parse query section */
resp->query = parse_dns_qsection(answer, size, &cp,
resp->header.qdcount);
if (resp->header.qdcount && resp->query == NULL) {
free_dns_response(resp);
return (NULL);
}
/* parse answer section */
resp->answer = parse_dns_rrsection(answer, size, &cp,
resp->header.ancount);
if (resp->header.ancount && resp->answer == NULL) {
free_dns_response(resp);
return (NULL);
}
/* parse authority section */
resp->authority = parse_dns_rrsection(answer, size, &cp,
resp->header.nscount);
if (resp->header.nscount && resp->authority == NULL) {
free_dns_response(resp);
return (NULL);
}
/* parse additional section */
resp->additional = parse_dns_rrsection(answer, size, &cp,
resp->header.arcount);
if (resp->header.arcount && resp->additional == NULL) {
free_dns_response(resp);
return (NULL);
}
return (resp);
}
static struct dns_query *
parse_dns_qsection(const u_char *answer, int size, const u_char **cp, int count)
{
struct dns_query *head, *curr, *prev;
int i, length;
char name[MAXDNAME];
for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
/* allocate and initialize struct */
curr = calloc(1, sizeof(struct dns_query));
if (curr == NULL) {
free_dns_query(head);
return (NULL);
}
if (head == NULL)
head = curr;
if (prev != NULL)
prev->next = curr;
/* name */
length = dn_expand(answer, answer + size, *cp, name,
sizeof(name));
if (length < 0) {
free_dns_query(head);
return (NULL);
}
curr->name = strdup(name);
if (curr->name == NULL) {
free_dns_query(head);
return (NULL);
}
*cp += length;
/* type */
curr->type = _getshort(*cp);
*cp += INT16SZ;
/* class */
curr->class = _getshort(*cp);
*cp += INT16SZ;
}
return (head);
}
static struct dns_rr *
parse_dns_rrsection(const u_char *answer, int size, const u_char **cp,
int count)
{
struct dns_rr *head, *curr, *prev;
int i, length;
char name[MAXDNAME];
for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
/* allocate and initialize struct */
curr = calloc(1, sizeof(struct dns_rr));
if (curr == NULL) {
free_dns_rr(head);
return (NULL);
}
if (head == NULL)
head = curr;
if (prev != NULL)
prev->next = curr;
/* name */
length = dn_expand(answer, answer + size, *cp, name,
sizeof(name));
if (length < 0) {
free_dns_rr(head);
return (NULL);
}
curr->name = strdup(name);
if (curr->name == NULL) {
free_dns_rr(head);
return (NULL);
}
*cp += length;
/* type */
curr->type = _getshort(*cp);
*cp += INT16SZ;
/* class */
curr->class = _getshort(*cp);
*cp += INT16SZ;
/* ttl */
curr->ttl = _getlong(*cp);
*cp += INT32SZ;
/* rdata size */
curr->size = _getshort(*cp);
*cp += INT16SZ;
/* rdata itself */
curr->rdata = malloc(curr->size);
if (curr->rdata == NULL) {
free_dns_rr(head);
return (NULL);
}
memcpy(curr->rdata, *cp, curr->size);
*cp += curr->size;
}
return (head);
}
static void
free_dns_query(struct dns_query *p)
{
if (p == NULL)
return;
if (p->name)
free(p->name);
free_dns_query(p->next);
free(p);
}
static void
free_dns_rr(struct dns_rr *p)
{
if (p == NULL)
return;
if (p->name)
free(p->name);
if (p->rdata)
free(p->rdata);
free_dns_rr(p->next);
free(p);
}
static void
free_dns_response(struct dns_response *p)
{
if (p == NULL)
return;
free_dns_query(p->query);
free_dns_rr(p->answer);
free_dns_rr(p->authority);
free_dns_rr(p->additional);
free(p);
}
static int
count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
{
int n = 0;
while(p) {
if (p->class == class && p->type == type)
n++;
p = p->next;
}
return (n);
}
#endif /* !defined(HAVE_GETRRSETBYNAME) */