612 lines
16 KiB
C
612 lines
16 KiB
C
/* Copyright (C) 1996 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* Parts of this file are plain copies of the file `getnetnamadr.c' from
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the bind package and it has the following copyright. */
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/* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
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* Dep. Matematica Universidade de Coimbra, Portugal, Europe
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*/
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/*
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* Copyright (c) 1983, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <ctype.h>
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#include <errno.h>
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#include <netdb.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <string.h>
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#include <sys/syslog.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <arpa/nameser.h>
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#include <resolv.h>
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#include "nsswitch.h"
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/* Get implementation for some internal functions. */
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#include "../resolv/mapv4v6addr.h"
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#include "../resolv/mapv4v6hostent.h"
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/* Maximum number of aliases we allow. */
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#define MAX_NR_ALIASES 48
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#define MAX_NR_ADDRS 48
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#if PACKETSZ > 1024
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# define MAXPACKET PACKETSZ
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#else
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# define MAXPACKET 1024
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#endif
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static const char AskedForGot[] = "\
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gethostby*.getanswer: asked for \"%s\", got \"%s\"";
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/* We need this time later. */
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typedef union querybuf
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{
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HEADER hdr;
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u_char buf[MAXPACKET];
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} querybuf;
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static enum nss_status getanswer_r (const querybuf *answer, int anslen,
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const char *qname, int qtype,
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struct hostent *result,
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char *buffer, int buflen, int *h_errnop);
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enum nss_status
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_nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result,
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char *buffer, int buflen, int *h_errnop)
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{
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struct host_data
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{
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char *aliases[MAX_NR_ALIASES];
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unsigned char host_addr[16]; /* IPv4 or IPv6 */
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char *h_addr_ptrs[MAX_NR_ADDRS + 1];
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char linebuffer[0];
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} *host_data = (struct host_data *) buffer;
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int linebuflen = buflen - offsetof (struct host_data, linebuffer);
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querybuf host_buffer;
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int size, type, n;
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const char *cp;
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switch (af) {
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case AF_INET:
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size = INADDRSZ;
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type = T_A;
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break;
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case AF_INET6:
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size = IN6ADDRSZ;
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type = T_AAAA;
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break;
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default:
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*h_errnop = NETDB_INTERNAL;
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errno = EAFNOSUPPORT;
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return NSS_STATUS_UNAVAIL;
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}
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result->h_addrtype = af;
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result->h_length = size;
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/*
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* if there aren't any dots, it could be a user-level alias.
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* this is also done in res_query() since we are not the only
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* function that looks up host names.
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*/
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if (strchr (name, '.') == NULL && (cp = __hostalias (name)) != NULL)
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name = cp;
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/*
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* disallow names consisting only of digits/dots, unless
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* they end in a dot.
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*/
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if (isdigit (name[0]))
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for (cp = name;; ++cp)
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{
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if (*cp == '\0')
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{
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char *bp;
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if (*--cp == '.')
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break;
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/*
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* All-numeric, no dot at the end. Fake up a hostent
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* as if we'd actually done a lookup.
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*/
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if (inet_pton (af, name, host_data->host_addr) <= 0)
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{
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*h_errnop = HOST_NOT_FOUND;
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return NSS_STATUS_NOTFOUND;
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}
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bp = __stpncpy (host_data->linebuffer, name, linebuflen);
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host_data->linebuffer[linebuflen - 1] = '\0';
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linebuflen -= bp - host_data->linebuffer;
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result->h_name = host_data->linebuffer;
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result->h_aliases = host_data->aliases;
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host_data->aliases[0] = NULL;
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host_data->h_addr_ptrs[0] = (char *) host_data->host_addr;
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host_data->h_addr_ptrs[1] = NULL;
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result->h_addr_list = host_data->h_addr_ptrs;
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if (_res.options & RES_USE_INET6)
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map_v4v6_hostent (result, &bp, &linebuflen);
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*h_errnop = NETDB_SUCCESS;
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return NSS_STATUS_SUCCESS;
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}
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if (!isdigit (*cp) && *cp != '.')
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break;
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}
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n = res_search (name, C_IN, type, host_buffer.buf, sizeof (host_buffer));
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if (n < 0)
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return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
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return getanswer_r (&host_buffer, n, name, type, result, buffer, buflen,
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h_errnop);
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}
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enum nss_status
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_nss_dns_gethostbyname_r (const char *name, struct hostent *result,
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char *buffer, int buflen, int *h_errnop)
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{
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enum nss_status status = NSS_STATUS_NOTFOUND;
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if (_res.options & RES_USE_INET6)
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status = _nss_dns_gethostbyname2_r (name, AF_INET6, result, buffer,
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buflen, h_errnop);
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if (status == NSS_STATUS_NOTFOUND)
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status = _nss_dns_gethostbyname2_r (name, AF_INET, result, buffer,
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buflen, h_errnop);
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return status;
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}
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enum nss_status
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_nss_dns_gethostbyaddr_r (const char *addr, int len, int af,
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struct hostent *result, char *buffer, int buflen,
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int *h_errnop)
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{
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static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
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static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
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const u_char *uaddr = (const u_char *)addr;
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struct host_data
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{
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char *aliases[MAX_NR_ALIASES];
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unsigned char host_addr[16]; /* IPv4 or IPv6 */
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char *h_addr_ptrs[MAX_NR_ADDRS + 1];
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char linebuffer[0];
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} *host_data = (struct host_data *) buffer;
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querybuf host_buffer;
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char qbuf[MAXDNAME+1], *qp;
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int size, n, status;
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if (af == AF_INET6 && len == IN6ADDRSZ &&
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(bcmp (uaddr, mapped, sizeof mapped) == 0
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|| bcmp (uaddr, tunnelled, sizeof tunnelled) == 0))
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{
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/* Unmap. */
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addr += sizeof mapped;
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uaddr += sizeof mapped;
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af = AF_INET;
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len = INADDRSZ;
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}
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switch (af)
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{
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case AF_INET:
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size = INADDRSZ;
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break;
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case AF_INET6:
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size = IN6ADDRSZ;
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break;
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default:
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errno = EAFNOSUPPORT;
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*h_errnop = NETDB_INTERNAL;
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return NSS_STATUS_UNAVAIL;
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}
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if (size != len)
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{
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errno = EAFNOSUPPORT;
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*h_errnop = NETDB_INTERNAL;
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return NSS_STATUS_UNAVAIL;
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}
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switch (af)
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{
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case AF_INET:
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sprintf (qbuf, "%u.%u.%u.%u.in-addr.arpa", (uaddr[3] & 0xff),
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(uaddr[2] & 0xff), (uaddr[1] & 0xff), (uaddr[0] & 0xff));
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break;
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case AF_INET6:
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qp = qbuf;
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for (n = IN6ADDRSZ - 1; n >= 0; n--)
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qp += sprintf (qp, "%x.%x.", uaddr[n] & 0xf, (uaddr[n] >> 4) & 0xf);
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strcpy(qp, "ip6.int");
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break;
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default:
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/* Cannot happen. */
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}
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n = res_query (qbuf, C_IN, T_PTR, (u_char *)host_buffer.buf,
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sizeof host_buffer);
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if (n < 0)
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return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
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status = getanswer_r (&host_buffer, n, qbuf, T_PTR, result, buffer, buflen,
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h_errnop);
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if (status != NSS_STATUS_SUCCESS)
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return status;
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#ifdef SUNSECURITY
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This is not implemented because it is not possible to use the current
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source from bind in a multi-threaded program.
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#endif
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result->h_addrtype = af;
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result->h_length = len;
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bcopy (addr, host_data->host_addr, len);
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host_data->h_addr_ptrs[0] = (char *) host_data->host_addr;
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host_data->h_addr_ptrs[1] = NULL;
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if (af == AF_INET && (_res.options & RES_USE_INET6))
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{
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map_v4v6_address ((char *) host_data->host_addr,
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(char *) host_data->host_addr);
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result->h_addrtype = AF_INET6;
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result->h_length = IN6ADDRSZ;
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}
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*h_errnop = NETDB_SUCCESS;
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return NSS_STATUS_SUCCESS;
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}
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static enum nss_status
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getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
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struct hostent *result, char *buffer, int buflen, int *h_errnop)
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{
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struct host_data
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{
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char *aliases[MAX_NR_ALIASES];
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unsigned char host_addr[16]; /* IPv4 or IPv6 */
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char *h_addr_ptrs[MAX_NR_ADDRS + 1];
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char linebuffer[0];
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} *host_data = (struct host_data *) buffer;
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int linebuflen = buflen - offsetof (struct host_data, linebuffer);
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register const HEADER *hp;
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const u_char *end_of_message, *cp;
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int n, ancount, qdcount;
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int haveanswer, had_error;
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char *bp, **ap, **hap;
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char tbuf[MAXDNAME+1];
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const char *tname;
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int (*name_ok) __P ((const char *));
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tname = qname;
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result->h_name = NULL;
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end_of_message = answer->buf + anslen;
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switch (qtype)
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{
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case T_A:
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case T_AAAA:
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name_ok = res_hnok;
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break;
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case T_PTR:
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name_ok = res_dnok;
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break;
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default:
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return NSS_STATUS_UNAVAIL; /* XXX should be abort(); */
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}
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/*
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* find first satisfactory answer
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*/
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hp = &answer->hdr;
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bp = host_data->linebuffer;
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ancount = ntohs (hp->ancount);
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qdcount = ntohs (hp->qdcount);
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cp = answer->buf + HFIXEDSZ;
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if (qdcount != 1)
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{
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*h_errnop = NO_RECOVERY;
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return NSS_STATUS_UNAVAIL;
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}
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n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
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if (n < 0 || (*name_ok) (bp) == 0)
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{
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*h_errnop = NO_RECOVERY;
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return NSS_STATUS_UNAVAIL;
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}
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cp += n + QFIXEDSZ;
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if (qtype == T_A || qtype == T_AAAA)
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{
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/* res_send() has already verified that the query name is the
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* same as the one we sent; this just gets the expanded name
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* (i.e., with the succeeding search-domain tacked on).
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*/
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n = strlen (bp) + 1; /* for the \0 */
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result->h_name = bp;
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bp += n;
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linebuflen -= n;
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/* The qname can be abbreviated, but h_name is now absolute. */
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qname = result->h_name;
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}
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ap = host_data->aliases;
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*ap = NULL;
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result->h_aliases = host_data->aliases;
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hap = host_data->h_addr_ptrs;
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*hap = NULL;
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result->h_addr_list = host_data->h_addr_ptrs;
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haveanswer = 0;
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had_error = 0;
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while (ancount-- > 0 && cp < end_of_message && had_error == 0)
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{
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int type, class;
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n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
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if (n < 0 || (*name_ok) (bp) == 0)
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{
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++had_error;
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continue;
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}
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cp += n; /* name */
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type = _getshort (cp);
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cp += INT16SZ; /* type */
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class = _getshort(cp);
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cp += INT16SZ + INT32SZ; /* class, TTL */
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n = _getshort(cp);
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cp += INT16SZ; /* len */
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if (class != C_IN)
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{
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/* XXX - debug? syslog? */
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cp += n;
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continue; /* XXX - had_error++ ? */
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}
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if ((qtype ==T_A || qtype == T_AAAA) && type == T_CNAME)
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{
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if (ap >= &host_data->aliases[MAX_NR_ALIASES - 1])
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continue;
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n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
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if (n < 0 || (*name_ok) (tbuf) == 0)
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{
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++had_error;
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continue;
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}
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cp += n;
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/* Store alias. */
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*ap++ = bp;
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n = strlen (bp) + 1; /* For the \0. */
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bp += n;
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linebuflen -= n;
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/* Get canonical name. */
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n = strlen (tbuf) + 1; /* For the \0. */
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if (n > buflen)
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{
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++had_error;
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continue;
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}
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strcpy (bp, tbuf);
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result->h_name = bp;
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bp += n;
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linebuflen -= n;
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continue;
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}
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if (qtype == T_PTR && type == T_CNAME)
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{
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n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
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if (n < 0 || res_hnok (tbuf) == 0)
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{
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++had_error;
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continue;
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}
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cp += n;
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/* Get canonical name. */
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n = strlen (tbuf) + 1; /* For the \0. */
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if (n > buflen)
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{
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++had_error;
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continue;
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}
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strcpy (bp, tbuf);
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tname = bp;
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bp += n;
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linebuflen -= n;
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continue;
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}
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if (type != qtype)
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{
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syslog (LOG_NOTICE | LOG_AUTH,
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"gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
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qname, p_class (C_IN), p_type (qtype), p_type (type));
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cp += n;
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continue; /* XXX - had_error++ ? */
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}
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switch (type)
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{
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case T_PTR:
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if (strcasecmp (tname, bp) != 0)
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{
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syslog (LOG_NOTICE | LOG_AUTH, AskedForGot, qname, bp);
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cp += n;
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continue; /* XXX - had_error++ ? */
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}
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n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen);
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if (n < 0 || res_hnok (bp) == 0)
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{
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++had_error;
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break;
|
|
}
|
|
#if MULTI_PTRS_ARE_ALIASES
|
|
cp += n;
|
|
if (haveanswer == 0)
|
|
result->h_name = bp;
|
|
else if (ap < &host_data->aliases[MAXALIASES-1])
|
|
*ap++ = bp;
|
|
else
|
|
n = -1;
|
|
if (n != -1)
|
|
{
|
|
n = strlen (bp) + 1; /* for the \0 */
|
|
bp += n;
|
|
linebuflen -= n;
|
|
}
|
|
break;
|
|
#else
|
|
result->h_name = bp;
|
|
if (_res.options & RES_USE_INET6)
|
|
{
|
|
n = strlen (bp) + 1; /* for the \0 */
|
|
bp += n;
|
|
linebuflen -= n;
|
|
map_v4v6_hostent (result, &bp, &linebuflen);
|
|
}
|
|
*h_errnop = NETDB_SUCCESS;
|
|
return NSS_STATUS_SUCCESS;
|
|
#endif
|
|
case T_A:
|
|
case T_AAAA:
|
|
if (strcasecmp (result->h_name, bp) != 0)
|
|
{
|
|
syslog (LOG_NOTICE | LOG_AUTH, AskedForGot, result->h_name, bp);
|
|
cp += n;
|
|
continue; /* XXX - had_error++ ? */
|
|
}
|
|
if (haveanswer)
|
|
{
|
|
if (n != result->h_length)
|
|
{
|
|
cp += n;
|
|
continue;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
register int nn;
|
|
|
|
result->h_name = bp;
|
|
nn = strlen (bp) + 1; /* for the \0 */
|
|
bp += nn;
|
|
linebuflen -= nn;
|
|
}
|
|
|
|
bp += sizeof (align) - ((u_long) bp % sizeof (align));
|
|
|
|
if (n >= linebuflen)
|
|
{
|
|
++had_error;
|
|
continue;
|
|
}
|
|
if (hap >= &host_data->h_addr_ptrs[MAX_NR_ADDRS-1])
|
|
{
|
|
cp += n;
|
|
continue;
|
|
}
|
|
bcopy (cp, *hap++ = bp, n);
|
|
bp += n;
|
|
cp += n;
|
|
linebuflen -= n;
|
|
break;
|
|
default:
|
|
abort ();
|
|
}
|
|
if (had_error == 0)
|
|
++haveanswer;
|
|
}
|
|
|
|
if (haveanswer > 0)
|
|
{
|
|
*ap = NULL;
|
|
*hap = NULL;
|
|
#if defined(RESOLVSORT)
|
|
/*
|
|
* Note: we sort even if host can take only one address
|
|
* in its return structures - should give it the "best"
|
|
* address in that case, not some random one
|
|
*/
|
|
if (_res.nsort && haveanswer > 1 && qtype == T_A)
|
|
addrsort (host_data->h_addr_ptrs, haveanswer);
|
|
#endif /*RESOLVSORT*/
|
|
|
|
if (result->h_name == NULL)
|
|
{
|
|
n = strlen (qname) + 1; /* For the \0. */
|
|
if (n > linebuflen)
|
|
goto try_again;
|
|
strcpy (bp, qname);
|
|
result->h_name = bp;
|
|
bp += n;
|
|
linebuflen -= n;
|
|
}
|
|
|
|
if (_res.options & RES_USE_INET6)
|
|
map_v4v6_hostent (result, &bp, &linebuflen);
|
|
*h_errnop = NETDB_SUCCESS;
|
|
return NSS_STATUS_SUCCESS;
|
|
}
|
|
try_again:
|
|
*h_errnop = TRY_AGAIN;
|
|
return NSS_STATUS_TRYAGAIN;
|
|
}
|