diff options
Diffstat (limited to 'nss/nss_dns/dns-host.c')
| -rw-r--r-- | nss/nss_dns/dns-host.c | 611 |
1 files changed, 611 insertions, 0 deletions
diff --git a/nss/nss_dns/dns-host.c b/nss/nss_dns/dns-host.c new file mode 100644 index 0000000000..eaa9e81218 --- /dev/null +++ b/nss/nss_dns/dns-host.c @@ -0,0 +1,611 @@ +/* Copyright (C) 1996 Free Software Foundation, Inc. +This file is part of the GNU C Library. +Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + +/* Parts of this file are plain copies of the file `getnetnamadr.c' from + the bind package and it has the following copyright. */ + +/* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro + * Dep. Matematica Universidade de Coimbra, Portugal, Europe + * + * 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. + */ +/* + * Copyright (c) 1983, 1993 + * The Regents of the University of California. 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. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. + */ + +#include <ctype.h> +#include <errno.h> +#include <netdb.h> +#include <stdio.h> +#include <stdlib.h> +#include <stddef.h> +#include <string.h> +#include <sys/syslog.h> + +#include <netinet/in.h> +#include <arpa/inet.h> +#include <arpa/nameser.h> +#include <resolv.h> + +#include "nsswitch.h" + +/* Get implementation for some internal functions. */ +#include "../resolv/mapv4v6addr.h" +#include "../resolv/mapv4v6hostent.h" + +/* Maximum number of aliases we allow. */ +#define MAX_NR_ALIASES 48 +#define MAX_NR_ADDRS 48 + +#if PACKETSZ > 1024 +# define MAXPACKET PACKETSZ +#else +# define MAXPACKET 1024 +#endif + +static const char AskedForGot[] = "\ +gethostby*.getanswer: asked for \"%s\", got \"%s\""; + + +/* We need this time later. */ +typedef union querybuf +{ + HEADER hdr; + u_char buf[MAXPACKET]; +} querybuf; + + +static enum nss_status getanswer_r (const querybuf *answer, int anslen, + const char *qname, int qtype, + struct hostent *result, + char *buffer, int buflen, int *h_errnop); + +enum nss_status +_nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result, + char *buffer, int buflen, int *h_errnop) +{ + struct host_data + { + char *aliases[MAX_NR_ALIASES]; + unsigned char host_addr[16]; /* IPv4 or IPv6 */ + char *h_addr_ptrs[MAX_NR_ADDRS + 1]; + char linebuffer[0]; + } *host_data = (struct host_data *) buffer; + int linebuflen = buflen - offsetof (struct host_data, linebuffer); + querybuf host_buffer; + int size, type, n; + const char *cp; + + switch (af) { + case AF_INET: + size = INADDRSZ; + type = T_A; + break; + case AF_INET6: + size = IN6ADDRSZ; + type = T_AAAA; + break; + default: + *h_errnop = NETDB_INTERNAL; + errno = EAFNOSUPPORT; + return NSS_STATUS_UNAVAIL; + } + + result->h_addrtype = af; + result->h_length = size; + + /* + * if there aren't any dots, it could be a user-level alias. + * this is also done in res_query() since we are not the only + * function that looks up host names. + */ + if (strchr (name, '.') == NULL && (cp = __hostalias (name)) != NULL) + name = cp; + + /* + * disallow names consisting only of digits/dots, unless + * they end in a dot. + */ + if (isdigit (name[0])) + for (cp = name;; ++cp) + { + if (*cp == '\0') + { + char *bp; + + if (*--cp == '.') + break; + /* + * All-numeric, no dot at the end. Fake up a hostent + * as if we'd actually done a lookup. + */ + if (inet_pton (af, name, host_data->host_addr) <= 0) + { + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + bp = __stpncpy (host_data->linebuffer, name, linebuflen); + host_data->linebuffer[linebuflen - 1] = '\0'; + linebuflen -= bp - host_data->linebuffer; + + result->h_name = host_data->linebuffer; + result->h_aliases = host_data->aliases; + host_data->aliases[0] = NULL; + host_data->h_addr_ptrs[0] = (char *) host_data->host_addr; + host_data->h_addr_ptrs[1] = NULL; + result->h_addr_list = host_data->h_addr_ptrs; + + if (_res.options & RES_USE_INET6) + map_v4v6_hostent (result, &bp, &linebuflen); + *h_errnop = NETDB_SUCCESS; + return NSS_STATUS_SUCCESS; + } + if (!isdigit (*cp) && *cp != '.') + break; + } + + n = res_search (name, C_IN, type, host_buffer.buf, sizeof (host_buffer)); + if (n < 0) + return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND; + + return getanswer_r (&host_buffer, n, name, type, result, buffer, buflen, + h_errnop); +} + + +enum nss_status +_nss_dns_gethostbyname_r (const char *name, struct hostent *result, + char *buffer, int buflen, int *h_errnop) +{ + enum nss_status status = NSS_STATUS_NOTFOUND; + + if (_res.options & RES_USE_INET6) + status = _nss_dns_gethostbyname2_r (name, AF_INET6, result, buffer, + buflen, h_errnop); + if (status == NSS_STATUS_NOTFOUND) + status = _nss_dns_gethostbyname2_r (name, AF_INET, result, buffer, + buflen, h_errnop); + + return status; +} + + +enum nss_status +_nss_dns_gethostbyaddr_r (const char *addr, int len, int af, + struct hostent *result, char *buffer, int buflen, + int *h_errnop) +{ + static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff }; + static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 }; + const u_char *uaddr = (const u_char *)addr; + struct host_data + { + char *aliases[MAX_NR_ALIASES]; + unsigned char host_addr[16]; /* IPv4 or IPv6 */ + char *h_addr_ptrs[MAX_NR_ADDRS + 1]; + char linebuffer[0]; + } *host_data = (struct host_data *) buffer; + querybuf host_buffer; + char qbuf[MAXDNAME+1], *qp; + int size, n, status; + + if (af == AF_INET6 && len == IN6ADDRSZ && + (bcmp (uaddr, mapped, sizeof mapped) == 0 + || bcmp (uaddr, tunnelled, sizeof tunnelled) == 0)) + { + /* Unmap. */ + addr += sizeof mapped; + uaddr += sizeof mapped; + af = AF_INET; + len = INADDRSZ; + } + + switch (af) + { + case AF_INET: + size = INADDRSZ; + break; + case AF_INET6: + size = IN6ADDRSZ; + break; + default: + errno = EAFNOSUPPORT; + *h_errnop = NETDB_INTERNAL; + return NSS_STATUS_UNAVAIL; + } + if (size != len) + { + errno = EAFNOSUPPORT; + *h_errnop = NETDB_INTERNAL; + return NSS_STATUS_UNAVAIL; + } + + switch (af) + { + case AF_INET: + sprintf (qbuf, "%u.%u.%u.%u.in-addr.arpa", (uaddr[3] & 0xff), + (uaddr[2] & 0xff), (uaddr[1] & 0xff), (uaddr[0] & 0xff)); + break; + case AF_INET6: + qp = qbuf; + for (n = IN6ADDRSZ - 1; n >= 0; n--) + qp += sprintf (qp, "%x.%x.", uaddr[n] & 0xf, (uaddr[n] >> 4) & 0xf); + strcpy(qp, "ip6.int"); + break; + default: + /* Cannot happen. */ + } + + n = res_query (qbuf, C_IN, T_PTR, (u_char *)host_buffer.buf, + sizeof host_buffer); + if (n < 0) + return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND; + + status = getanswer_r (&host_buffer, n, qbuf, T_PTR, result, buffer, buflen, + h_errnop); + if (status != NSS_STATUS_SUCCESS) + return status; + +#ifdef SUNSECURITY + This is not implemented because it is not possible to use the current + source from bind in a multi-threaded program. +#endif + + result->h_addrtype = af; + result->h_length = len; + bcopy (addr, host_data->host_addr, len); + host_data->h_addr_ptrs[0] = (char *) host_data->host_addr; + host_data->h_addr_ptrs[1] = NULL; + if (af == AF_INET && (_res.options & RES_USE_INET6)) + { + map_v4v6_address ((char *) host_data->host_addr, + (char *) host_data->host_addr); + result->h_addrtype = AF_INET6; + result->h_length = IN6ADDRSZ; + } + *h_errnop = NETDB_SUCCESS; + return NSS_STATUS_SUCCESS; +} + + +static enum nss_status +getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype, + struct hostent *result, char *buffer, int buflen, int *h_errnop) +{ + struct host_data + { + char *aliases[MAX_NR_ALIASES]; + unsigned char host_addr[16]; /* IPv4 or IPv6 */ + char *h_addr_ptrs[MAX_NR_ADDRS + 1]; + char linebuffer[0]; + } *host_data = (struct host_data *) buffer; + int linebuflen = buflen - offsetof (struct host_data, linebuffer); + register const HEADER *hp; + const u_char *end_of_message, *cp; + int n, ancount, qdcount; + int haveanswer, had_error; + char *bp, **ap, **hap; + char tbuf[MAXDNAME+1]; + const char *tname; + int (*name_ok) __P ((const char *)); + + tname = qname; + result->h_name = NULL; + end_of_message = answer->buf + anslen; + switch (qtype) + { + case T_A: + case T_AAAA: + name_ok = res_hnok; + break; + case T_PTR: + name_ok = res_dnok; + break; + default: + return NSS_STATUS_UNAVAIL; /* XXX should be abort(); */ + } + + /* + * find first satisfactory answer + */ + hp = &answer->hdr; + bp = host_data->linebuffer; + ancount = ntohs (hp->ancount); + qdcount = ntohs (hp->qdcount); + cp = answer->buf + HFIXEDSZ; + if (qdcount != 1) + { + *h_errnop = NO_RECOVERY; + return NSS_STATUS_UNAVAIL; + } + + n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen); + if (n < 0 || (*name_ok) (bp) == 0) + { + *h_errnop = NO_RECOVERY; + return NSS_STATUS_UNAVAIL; + } + cp += n + QFIXEDSZ; + + if (qtype == T_A || qtype == T_AAAA) + { + /* res_send() has already verified that the query name is the + * same as the one we sent; this just gets the expanded name + * (i.e., with the succeeding search-domain tacked on). + */ + n = strlen (bp) + 1; /* for the \0 */ + result->h_name = bp; + bp += n; + linebuflen -= n; + /* The qname can be abbreviated, but h_name is now absolute. */ + qname = result->h_name; + } + + ap = host_data->aliases; + *ap = NULL; + result->h_aliases = host_data->aliases; + hap = host_data->h_addr_ptrs; + *hap = NULL; + result->h_addr_list = host_data->h_addr_ptrs; + haveanswer = 0; + had_error = 0; + + while (ancount-- > 0 && cp < end_of_message && had_error == 0) + { + int type, class; + + n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen); + if (n < 0 || (*name_ok) (bp) == 0) + { + ++had_error; + continue; + } + cp += n; /* name */ + type = _getshort (cp); + cp += INT16SZ; /* type */ + class = _getshort(cp); + cp += INT16SZ + INT32SZ; /* class, TTL */ + n = _getshort(cp); + cp += INT16SZ; /* len */ + if (class != C_IN) + { + /* XXX - debug? syslog? */ + cp += n; + continue; /* XXX - had_error++ ? */ + } + + if ((qtype ==T_A || qtype == T_AAAA) && type == T_CNAME) + { + if (ap >= &host_data->aliases[MAX_NR_ALIASES - 1]) + continue; + n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf); + if (n < 0 || (*name_ok) (tbuf) == 0) + { + ++had_error; + continue; + } + cp += n; + /* Store alias. */ + *ap++ = bp; + n = strlen (bp) + 1; /* For the \0. */ + bp += n; + linebuflen -= n; + /* Get canonical name. */ + n = strlen (tbuf) + 1; /* For the \0. */ + if (n > buflen) + { + ++had_error; + continue; + } + strcpy (bp, tbuf); + result->h_name = bp; + bp += n; + linebuflen -= n; + continue; + } + + if (qtype == T_PTR && type == T_CNAME) + { + n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf); + if (n < 0 || res_hnok (tbuf) == 0) + { + ++had_error; + continue; + } + cp += n; + /* Get canonical name. */ + n = strlen (tbuf) + 1; /* For the \0. */ + if (n > buflen) + { + ++had_error; + continue; + } + strcpy (bp, tbuf); + tname = bp; + bp += n; + linebuflen -= n; + continue; + } + if (type != qtype) + { + syslog (LOG_NOTICE | LOG_AUTH, + "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", + qname, p_class (C_IN), p_type (qtype), p_type (type)); + cp += n; + continue; /* XXX - had_error++ ? */ + } + + switch (type) + { + case T_PTR: + if (strcasecmp (tname, bp) != 0) + { + syslog (LOG_NOTICE | LOG_AUTH, AskedForGot, qname, bp); + cp += n; + continue; /* XXX - had_error++ ? */ + } + n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen); + if (n < 0 || res_hnok (bp) == 0) + { + ++had_error; + 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; +} |