diff options
Diffstat (limited to 'nss/nss_dns/dns-network.c')
| -rw-r--r-- | nss/nss_dns/dns-network.c | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/nss/nss_dns/dns-network.c b/nss/nss_dns/dns-network.c new file mode 100644 index 0000000..b714128 --- /dev/null +++ b/nss/nss_dns/dns-network.c @@ -0,0 +1,338 @@ +/* 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 <string.h> + +#include "nsswitch.h" +#include <arpa/inet.h> + +/* Maximum number of aliases we allow. */ +#define MAX_NR_ALIASES 48 + + +#if PACKETSZ > 1024 +#define MAXPACKET PACKETSZ +#else +#define MAXPACKET 1024 +#endif + + +typedef enum +{ + BYADDR, + BYNAME +} lookup_method; + + +/* We need this time later. */ +typedef union querybuf +{ + HEADER hdr; + u_char buf[MAXPACKET]; +} querybuf; + + +/* Protortypes for local functions. */ +static int getanswer_r (const querybuf *answer, int anslen, + struct netent *result, char *buffer, int buflen, + lookup_method net_i); + + +int +_nss_dns_getnetbyname_r (const char *name, struct netent *result, + char *buffer, int buflen) +{ + /* Return entry for network with NAME. */ + querybuf net_buffer; + int anslen; + char *qbuf; + + qbuf = strdupa (name); + anslen = res_search (qbuf, C_IN, T_PTR, (u_char *) &net_buffer, + sizeof (querybuf)); + if (anslen < 0) + /* Nothing found. */ + return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND; + + return getanswer_r (&net_buffer, anslen, result, buffer, buflen, BYNAME); +} + + +int +_nss_dns_getnetbyaddr_r (long net, int type, struct netent *result, + char *buffer, int buflen) +{ + /* Return entry for network with NAME. */ + int status; + querybuf net_buffer; + unsigned int net_bytes[4]; + char qbuf[MAXDNAME]; + int cnt, anslen; + u_int32_t net2; + + /* No net address lookup for IPv6 yet. */ + if (type != AF_INET) + return NSS_STATUS_UNAVAIL; + + net2 = (u_int32_t) net; + for (cnt = 4; net2 != 0; net2 >>= 8) + net_bytes[--cnt] = net2 & 0xff; + + switch (cnt) + { + case 3: + /* Class A network. */ + sprintf (qbuf, "0.0.0.%u.in-addr.arpa", net_bytes[3]); + break; + case 2: + /* Class B network. */ + sprintf (qbuf, "0.0.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2]); + break; + case 1: + /* Class C network. */ + sprintf (qbuf, "0.%u.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2], + net_bytes[1]); + break; + case 0: + /* Class D - E network. */ + sprintf (qbuf, "%u.%u.%u.%u.in-addr.arpa", net_bytes[3], net_bytes[2], + net_bytes[1], net_bytes[0]); + break; + } + + anslen = res_query (qbuf, C_IN, T_PTR, (u_char *) &net_buffer, + sizeof (querybuf)); + if (anslen < 0) + /* Nothing found. */ + return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND; + + status = getanswer_r (&net_buffer, anslen, result, buffer, buflen, BYADDR); + if (status == NSS_STATUS_SUCCESS) + { + /* Strip trailing zeros. */ + unsigned int u_net = net; /* Maybe net should be unsigned? */ + + while ((u_net & 0xff) == 0 && u_net != 0) + u_net >>= 8; + result->n_net = u_net; + } + + return status; +} + + +#undef offsetof +#define offsetof(Type, Member) ((size_t) &((Type *) NULL)->Member) + +static int +getanswer_r (const querybuf *answer, int anslen, struct netent *result, + char *buffer, int buflen, lookup_method net_i) +{ + /* + * Find first satisfactory answer + * + * answer --> +------------+ ( MESSAGE ) + * | Header | + * +------------+ + * | Question | the question for the name server + * +------------+ + * | Answer | RRs answering the question + * +------------+ + * | Authority | RRs pointing toward an authority + * | Additional | RRs holding additional information + * +------------+ + */ + struct net_data + { + char *aliases[MAX_NR_ALIASES]; + char linebuffer[0]; + } *net_data = (struct net_data *) buffer; + int linebuflen = buflen - offsetof (struct net_data, linebuffer); + const char *end_of_message = &answer->buf[anslen]; + const HEADER *header_pointer = &answer->hdr; + /* #/records in the answer section. */ + int answer_count = ntohs (header_pointer->ancount); + /* #/entries in the question section. */ + int question_count = ntohs (header_pointer->qdcount); + char *bp = net_data->linebuffer; + const char *cp = &answer->buf[HFIXEDSZ]; + char **alias_pointer; + int have_answer; + char *ans; + + if (question_count == 0) + /* FIXME: the Sun version uses for host name lookup an additional + parameter for pointing to h_errno. this is missing here. + OSF/1 has a per-thread h_errno variable. */ + if (header_pointer->aa != 0) + { + h_errno = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + else + { + h_errno = TRY_AGAIN; + return NSS_STATUS_TRYAGAIN; + } + + /* Skip the question part. */ + while (question_count-- > 0) + cp += __dn_skipname (cp, end_of_message) + QFIXEDSZ; + + alias_pointer = result->n_aliases = &net_data->aliases[0]; + *alias_pointer = NULL; + have_answer = 0; + ans = NULL; + + while (--answer_count >= 0 && cp < end_of_message) + { + int n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen); + int type, class; + + if (n < 0 || res_dnok (bp) == 0) + break; + cp += n; + ans = strdupa (bp); + GETSHORT (type, cp); + GETSHORT (class, cp); + cp += INT32SZ; /* TTL */ + GETSHORT (n, cp); + + if (class == C_IN && type == T_PTR) + { + n = dn_expand (answer->buf, end_of_message, cp, bp, linebuflen); + if (n < 0 || !res_hnok (bp)) + { + /* XXX What does this mean? The original form from bind + returns NULL. Incrementing cp has no effect in any case. + What should I return here. ??? */ + cp += n; + return NSS_STATUS_UNAVAIL; + } + cp += n; + *alias_pointer++ = bp; + bp += strlen (bp) + 1; + result->n_addrtype = class == C_IN ? AF_INET : AF_UNSPEC; + ++have_answer; + } + } + + if (have_answer) + { + char *tmp; + int len; + char *in, *cp, *rp, *wp; + int cnt, first_flag; + + *alias_pointer = NULL; + switch (net_i) + { + case BYADDR: + result->n_name = result->n_aliases[0]; + result->n_net = 0L; + break; + case BYNAME: + len = strlen (result->n_aliases[0]); + tmp = (char *) alloca (len + 1); + tmp[len] = 0; + wp = &tmp[len - 1]; + + rp = in = result->n_aliases[0]; + result->n_name = ans; + + first_flag = 1; + for (cnt = 0; cnt < 4; ++cnt) + { + char *startp; + + startp = rp; + while (*rp != '.') + ++rp; + if (rp - startp > 1 || *startp != '0' || !first_flag) + { + first_flag = 0; + if (cnt > 0) + *wp-- = '.'; + cp = rp; + while (cp > startp) + *wp-- = *--cp; + } + in = rp + 1; + } + + result->n_net = inet_network (wp); + break; + } + + ++result->n_aliases; + return NSS_STATUS_SUCCESS; + } + + /* XXX Really use global variable??? */ + h_errno = TRY_AGAIN; + return NSS_STATUS_TRYAGAIN; +} |