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- /* resolv.c: DNS Resolver
- *
- * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>,
- * The Silver Hammer Group, Ltd.
- *
- * This 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.
- */
- /*
- * Portions Copyright (c) 1985, 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.
- * 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.
- */
- /*
- * Portions Copyright (c) 1993 by Digital Equipment Corporation.
- *
- * 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, and that
- * the name of Digital Equipment Corporation not be used in advertising or
- * publicity pertaining to distribution of the document or software without
- * specific, written prior permission.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
- * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
- * CORPORATION 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.
- */
- /*
- * Portions Copyright (c) 1996-1999 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 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.
- */
- /*
- *
- * 5-Oct-2000 W. Greathouse wgreathouse@smva.com
- * Fix memory leak and memory corruption.
- * -- Every name resolution resulted in
- * a new parse of resolv.conf and new
- * copy of nameservers allocated by
- * strdup.
- * -- Every name resolution resulted in
- * a new read of resolv.conf without
- * resetting index from prior read...
- * resulting in exceeding array bounds.
- *
- * Limit nameservers read from resolv.conf
- *
- * Add "search" domains from resolv.conf
- *
- * Some systems will return a security
- * signature along with query answer for
- * dynamic DNS entries.
- * -- skip/ignore this answer
- *
- * Include arpa/nameser.h for defines.
- *
- * General cleanup
- *
- * 20-Jun-2001 Michal Moskal <malekith@pld.org.pl>
- * partial IPv6 support (i.e. gethostbyname2() and resolve_address2()
- * functions added), IPv6 nameservers are also supported.
- *
- * 6-Oct-2001 Jari Korva <jari.korva@iki.fi>
- * more IPv6 support (IPv6 support for gethostbyaddr();
- * address family parameter and improved IPv6 support for get_hosts_byname
- * and read_etc_hosts; getnameinfo() port from glibc; defined
- * defined ip6addr_any and in6addr_loopback)
- *
- * 2-Feb-2002 Erik Andersen <andersen@codepoet.org>
- * Added gethostent(), sethostent(), and endhostent()
- *
- * 17-Aug-2002 Manuel Novoa III <mjn3@codepoet.org>
- * Fixed __read_etc_hosts_r to return alias list, and modified buffer
- * allocation accordingly. See MAX_ALIASES and ALIAS_DIM below.
- * This fixes the segfault in the Python 2.2.1 socket test.
- *
- * 04-Jan-2003 Jay Kulpinski <jskulpin@berkshire.rr.com>
- * Fixed __decode_dotted to count the terminating null character
- * in a host name.
- *
- * 02-Oct-2003 Tony J. White <tjw@tjw.org>
- * Lifted dn_expand() and dependent ns_name_uncompress(), ns_name_unpack(),
- * and ns_name_ntop() from glibc 2.3.2 for compatibility with ipsec-tools
- * and openldap.
- *
- * 7-Sep-2004 Erik Andersen <andersen@codepoet.org>
- * Added gethostent_r()
- *
- */
- #define __FORCE_GLIBC
- #include <features.h>
- #include <string.h>
- #include <stdio.h>
- #include <signal.h>
- #include <errno.h>
- #include <sys/poll.h>
- #include <sys/socket.h>
- #include <sys/types.h>
- #include <sys/time.h>
- #include <netinet/in.h>
- #include <arpa/inet.h>
- #include <stdlib.h>
- #include <unistd.h>
- #include <resolv.h>
- #include <netdb.h>
- #include <ctype.h>
- #include <stdbool.h>
- #include <arpa/nameser.h>
- #include <sys/utsname.h>
- #include <sys/un.h>
- #include <bits/uClibc_mutex.h>
- /* poll() is not supported in kernel <= 2.0, therefore if __NR_poll is
- * not available, we assume an old Linux kernel is in use and we will
- * use select() instead. */
- #include <sys/syscall.h>
- #ifndef __NR_poll
- # define USE_SELECT
- #endif
- /* Experimentally off - libc_hidden_proto(memcpy) */
- /* Experimentally off - libc_hidden_proto(memset) */
- /* Experimentally off - libc_hidden_proto(memmove) */
- /* Experimentally off - libc_hidden_proto(strchr) */
- /* Experimentally off - libc_hidden_proto(strcmp) */
- /* Experimentally off - libc_hidden_proto(strcpy) */
- /* Experimentally off - libc_hidden_proto(strdup) */
- /* Experimentally off - libc_hidden_proto(strlen) */
- /* Experimentally off - libc_hidden_proto(strncat) */
- /* Experimentally off - libc_hidden_proto(strncpy) */
- /* libc_hidden_proto(strnlen) */
- /* Experimentally off - libc_hidden_proto(strstr) */
- /* Experimentally off - libc_hidden_proto(strcasecmp) */
- /* libc_hidden_proto(socket) */
- /* libc_hidden_proto(close) */
- /* libc_hidden_proto(fopen) */
- /* libc_hidden_proto(fclose) */
- /* libc_hidden_proto(random) */
- /* libc_hidden_proto(getservbyport) */
- /* libc_hidden_proto(gethostname) */
- /* libc_hidden_proto(uname) */
- /* libc_hidden_proto(inet_addr) */
- /* libc_hidden_proto(inet_aton) */
- /* libc_hidden_proto(inet_pton) */
- /* libc_hidden_proto(inet_ntop) */
- /* libc_hidden_proto(connect) */
- /* libc_hidden_proto(poll) */
- /* libc_hidden_proto(select) */
- /* libc_hidden_proto(recv) */
- /* libc_hidden_proto(send) */
- /* libc_hidden_proto(printf) */
- /* libc_hidden_proto(sprintf) */
- /* libc_hidden_proto(snprintf) */
- /* libc_hidden_proto(fgets) */
- /* libc_hidden_proto(getnameinfo) */
- /* libc_hidden_proto(gethostbyname) */
- /* libc_hidden_proto(gethostbyname_r) */
- /* libc_hidden_proto(gethostbyname2_r) */
- /* libc_hidden_proto(gethostbyaddr) */
- /* libc_hidden_proto(gethostbyaddr_r) */
- /* libc_hidden_proto(ns_name_uncompress) */
- /* libc_hidden_proto(ns_name_unpack) */
- /* libc_hidden_proto(ns_name_ntop) */
- /* libc_hidden_proto(res_init) */
- /* libc_hidden_proto(res_query) */
- /* libc_hidden_proto(res_querydomain) */
- /* libc_hidden_proto(gethostent_r) */
- /* libc_hidden_proto(fprintf) */
- /* libc_hidden_proto(__h_errno_location) */
- #ifdef __UCLIBC_HAS_XLOCALE__
- /* libc_hidden_proto(__ctype_b_loc) */
- #elif defined __UCLIBC_HAS_CTYPE_TABLES__
- /* libc_hidden_proto(__ctype_b) */
- #endif
- extern int __libc_getdomainname(char *name, size_t len);
- libc_hidden_proto(__libc_getdomainname)
- #define MAX_RECURSE 5
- #define MAX_ALIASES 5
- /* 1:ip + 1:full + MAX_ALIASES:aliases + 1:NULL */
- #define ALIAS_DIM (2 + MAX_ALIASES + 1)
- #undef DEBUG
- /* #define DEBUG */
- #ifdef DEBUG
- #define DPRINTF(X,args...) fprintf(stderr, X, ##args)
- #else
- #define DPRINTF(X,args...)
- #endif
- #undef ARRAY_SIZE
- #define ARRAY_SIZE(v) (sizeof(v) / sizeof((v)[0]))
- /* Make sure the incoming char * buffer is aligned enough to handle our random
- * structures. This define is the same as we use for malloc alignment (which
- * has same requirements). The offset is the number of bytes we need to adjust
- * in order to attain desired alignment.
- */
- #define ALIGN_ATTR __alignof__(double __attribute_aligned__ (sizeof(size_t)))
- #define ALIGN_BUFFER_OFFSET(buf) ((ALIGN_ATTR - ((size_t)buf % ALIGN_ATTR)) % ALIGN_ATTR)
- /* Structs */
- struct resolv_header {
- int id;
- int qr,opcode,aa,tc,rd,ra,rcode;
- int qdcount;
- int ancount;
- int nscount;
- int arcount;
- };
- struct resolv_question {
- char * dotted;
- int qtype;
- int qclass;
- };
- struct resolv_answer {
- char * dotted;
- int atype;
- int aclass;
- int ttl;
- int rdlength;
- const unsigned char * rdata;
- int rdoffset;
- char* buf;
- size_t buflen;
- size_t add_count;
- };
- enum etc_hosts_action {
- GET_HOSTS_BYNAME = 0,
- GETHOSTENT,
- GET_HOSTS_BYADDR,
- };
- typedef union sockaddr46_t {
- struct sockaddr sa;
- #ifdef __UCLIBC_HAS_IPV4__
- struct sockaddr_in sa4;
- #endif
- #ifdef __UCLIBC_HAS_IPV6__
- struct sockaddr_in6 sa6;
- #endif
- } sockaddr46_t;
- __UCLIBC_MUTEX_EXTERN(__resolv_lock);
- /* Protected by __resolv_lock */
- extern void (*__res_sync)(void) attribute_hidden;
- //extern uint32_t __resolv_opts attribute_hidden;
- extern unsigned __nameservers attribute_hidden;
- extern unsigned __searchdomains attribute_hidden;
- extern sockaddr46_t *__nameserver attribute_hidden;
- extern char **__searchdomain attribute_hidden;
- #ifdef __UCLIBC_HAS_IPV4__
- extern const struct sockaddr_in __local_nameserver attribute_hidden;
- #else
- extern const struct sockaddr_in6 __local_nameserver attribute_hidden;
- #endif
- /* Arbitrary */
- #define MAXLEN_searchdomain 128
- /* function prototypes */
- extern int __get_hosts_byname_r(const char * name, int type,
- struct hostent * result_buf,
- char * buf, size_t buflen,
- struct hostent ** result,
- int * h_errnop) attribute_hidden;
- extern int __get_hosts_byaddr_r(const char * addr, int len, int type,
- struct hostent * result_buf,
- char * buf, size_t buflen,
- struct hostent ** result,
- int * h_errnop) attribute_hidden;
- extern FILE * __open_etc_hosts(void) attribute_hidden;
- extern int __read_etc_hosts_r(FILE *fp, const char * name, int type,
- enum etc_hosts_action action,
- struct hostent * result_buf,
- char * buf, size_t buflen,
- struct hostent ** result,
- int * h_errnop) attribute_hidden;
- extern int __dns_lookup(const char * name, int type,
- unsigned char ** outpacket,
- struct resolv_answer * a) attribute_hidden;
- extern int __encode_dotted(const char * dotted, unsigned char * dest, int maxlen) attribute_hidden;
- extern int __decode_dotted(const unsigned char * const message, int offset,
- char * dest, int maxlen) attribute_hidden;
- extern int __length_dotted(const unsigned char * const message, int offset) attribute_hidden;
- extern int __encode_header(struct resolv_header * h, unsigned char * dest, int maxlen) attribute_hidden;
- extern void __decode_header(unsigned char * data, struct resolv_header * h) attribute_hidden;
- extern int __encode_question(const struct resolv_question * const q,
- unsigned char * dest, int maxlen) attribute_hidden;
- extern int __decode_question(const unsigned char * const message, int offset,
- struct resolv_question * q) attribute_hidden;
- extern int __encode_answer(struct resolv_answer * a,
- unsigned char * dest, int maxlen) attribute_hidden;
- extern int __decode_answer(const unsigned char * message, int offset,
- int len, struct resolv_answer * a) attribute_hidden;
- extern int __length_question(const unsigned char * const message, int offset) attribute_hidden;
- extern void __open_nameservers(void) attribute_hidden;
- extern void __close_nameservers(void) attribute_hidden;
- extern int __dn_expand(const u_char *, const u_char *, const u_char *,
- char *, int);
- /*
- * Theory of operation.
- *
- * gethostbyname, getaddrinfo and friends end up here, and they sometimes
- * need to talk to DNS servers. In order to do this, we need to read /etc/resolv.conf
- * and determine servers' addresses and the like. resolv.conf format:
- *
- * nameserver <IP[v6]>
- * Address of DNS server. Cumulative.
- * If not specified, assumed to be on localhost.
- * search <domain1>[ <domain2>]...
- * Append these domains to unqualified names.
- * See ndots:n option.
- * $LOCALDOMAIN (space-separated list) overrides this.
- * domain <domain>
- * Effectively same as "search" with one domain.
- * If no "domain" line is present, the domain is determined
- * from the local host name returned by gethostname();
- * the domain part is taken to be everything after the first dot.
- * If there are no dots, there will be no "domain".
- * The domain and search keywords are mutually exclusive.
- * If more than one instance of these keywords is present,
- * the last instance wins.
- * sortlist 130.155.160.0[/255.255.240.0] 130.155.0.0
- * Allows addresses returned by gethostbyname to be sorted.
- * Not supported.
- * options option[ option]...
- * (so far we support none)
- * $RES_OPTIONS (space-separated list) is to be added to "options"
- * debug sets RES_DEBUG in _res.options
- * ndots:n how many dots there should be so that name will be tried
- * first as an absolute name before any search list elements
- * are appended to it. Default 1
- * timeout:n how long to wait for response. Default 5
- * (sun seems to have retrans:n synonym)
- * attempts:n number of rounds to do before giving up and returning
- * an error. Default 2
- * (sun seems to have retry:n synonym)
- * rotate sets RES_ROTATE in _res.options, round robin
- * selection of nameservers. Otherwise try
- * the first listed server first every time
- * no-check-names
- * sets RES_NOCHECKNAME in _res.options, which disables
- * checking of incoming host names for invalid characters
- * such as underscore (_), non-ASCII, or control characters
- * inet6 sets RES_USE_INET6 in _res.options. Try a AAAA query
- * before an A query inside the gethostbyname(), and map
- * IPv4 responses in IPv6 "tunnelled form" if no AAAA records
- * are found but an A record set exists
- * no_tld_query (FreeBSDism?)
- * do not attempt to resolve names without dots
- *
- * We will read and analyze /etc/resolv.conf as needed before
- * we do a DNS request. This happens in __dns_lookup.
- * (TODO: also re-parse it after a timeout, to catch updates).
- *
- * BSD has res_init routine which is used to initialize resolver state
- * which is held in global structure _res.
- * Generally, programs call res_init, then fiddle with _res.XXX
- * (_res.options and _res.nscount, _res.nsaddr_list[N]
- * are popular targets of fiddling) and expect subsequent calls
- * to gethostbyname, getaddrinfo, etc to use modified information.
- *
- * However, historical _res structure is quite awkward.
- * Using it for storing /etc/resolv.conf info is not desirable,
- * and __dns_lookup does not use it.
- *
- * We would like to avoid using it unless absolutely necessary.
- * If user doesn't use res_init, we should arrange it so that
- * _res structure doesn't even *get linked in* into user's application
- * (imagine static uclibc build here).
- *
- * The solution is a __res_sync function pointer, which is normally NULL.
- * But if res_init is called, it gets set and any subsequent gethostbyname
- * et al "syncronizes" our internal structures with potentially
- * modified _res.XXX stuff by calling __res_sync.
- * The trick here is that if res_init is not used and not linked in,
- * gethostbyname itself won't reference _res and _res won't be linked in
- * either. Other possible methods like
- * if (__res_sync_just_an_int_flag)
- * __sync_me_with_res()
- * would pull in __sync_me_with_res, which pulls in _res. Bad.
- */
- #ifdef L_encodeh
- int attribute_hidden __encode_header(struct resolv_header *h, unsigned char *dest, int maxlen)
- {
- if (maxlen < HFIXEDSZ)
- return -1;
- dest[0] = (h->id & 0xff00) >> 8;
- dest[1] = (h->id & 0x00ff) >> 0;
- dest[2] = (h->qr ? 0x80 : 0) |
- ((h->opcode & 0x0f) << 3) |
- (h->aa ? 0x04 : 0) |
- (h->tc ? 0x02 : 0) |
- (h->rd ? 0x01 : 0);
- dest[3] = (h->ra ? 0x80 : 0) | (h->rcode & 0x0f);
- dest[4] = (h->qdcount & 0xff00) >> 8;
- dest[5] = (h->qdcount & 0x00ff) >> 0;
- dest[6] = (h->ancount & 0xff00) >> 8;
- dest[7] = (h->ancount & 0x00ff) >> 0;
- dest[8] = (h->nscount & 0xff00) >> 8;
- dest[9] = (h->nscount & 0x00ff) >> 0;
- dest[10] = (h->arcount & 0xff00) >> 8;
- dest[11] = (h->arcount & 0x00ff) >> 0;
- return HFIXEDSZ;
- }
- #endif
- #ifdef L_decodeh
- void attribute_hidden __decode_header(unsigned char *data, struct resolv_header *h)
- {
- h->id = (data[0] << 8) | data[1];
- h->qr = (data[2] & 0x80) ? 1 : 0;
- h->opcode = (data[2] >> 3) & 0x0f;
- h->aa = (data[2] & 0x04) ? 1 : 0;
- h->tc = (data[2] & 0x02) ? 1 : 0;
- h->rd = (data[2] & 0x01) ? 1 : 0;
- h->ra = (data[3] & 0x80) ? 1 : 0;
- h->rcode = data[3] & 0x0f;
- h->qdcount = (data[4] << 8) | data[5];
- h->ancount = (data[6] << 8) | data[7];
- h->nscount = (data[8] << 8) | data[9];
- h->arcount = (data[10] << 8) | data[11];
- }
- #endif
- #ifdef L_encoded
- /* Encode a dotted string into nameserver transport-level encoding.
- This routine is fairly dumb, and doesn't attempt to compress
- the data */
- int attribute_hidden __encode_dotted(const char *dotted, unsigned char *dest, int maxlen)
- {
- unsigned used = 0;
- while (dotted && *dotted) {
- char *c = strchr(dotted, '.');
- int l = c ? c - dotted : strlen(dotted);
- /* two consecutive dots are not valid */
- if (l == 0)
- return -1;
- if (l >= (maxlen - used - 1))
- return -1;
- dest[used++] = l;
- memcpy(dest + used, dotted, l);
- used += l;
- if (!c)
- break;
- dotted = c + 1;
- }
- if (maxlen < 1)
- return -1;
- dest[used++] = 0;
- return used;
- }
- #endif
- #ifdef L_decoded
- /* Decode a dotted string from nameserver transport-level encoding.
- This routine understands compressed data. */
- int attribute_hidden __decode_dotted(const unsigned char * const data, int offset,
- char *dest, int maxlen)
- {
- int l;
- bool measure = 1;
- unsigned total = 0;
- unsigned used = 0;
- if (!data)
- return -1;
- while ((l = data[offset++])) {
- if (measure)
- total++;
- if ((l & 0xc0) == (0xc0)) {
- if (measure)
- total++;
- /* compressed item, redirect */
- offset = ((l & 0x3f) << 8) | data[offset];
- measure = 0;
- continue;
- }
- if ((used + l + 1) >= maxlen)
- return -1;
- memcpy(dest + used, data + offset, l);
- offset += l;
- used += l;
- if (measure)
- total += l;
- if (data[offset] != 0)
- dest[used++] = '.';
- else
- dest[used++] = '\0';
- }
- /* The null byte must be counted too */
- if (measure)
- total++;
- DPRINTF("Total decode len = %d\n", total);
- return total;
- }
- #endif
- #ifdef L_lengthd
- /* Returns -1 only if data == NULL */
- int attribute_hidden __length_dotted(const unsigned char * const data, int offset)
- {
- int orig_offset = offset;
- int l;
- if (!data)
- return -1;
- while ((l = data[offset++])) {
- if ((l & 0xc0) == (0xc0)) {
- offset++;
- break;
- }
- offset += l;
- }
- return offset - orig_offset;
- }
- #endif
- #ifdef L_encodeq
- int attribute_hidden __encode_question(const struct resolv_question * const q,
- unsigned char *dest, int maxlen)
- {
- int i;
- i = __encode_dotted(q->dotted, dest, maxlen);
- if (i < 0)
- return i;
- dest += i;
- maxlen -= i;
- if (maxlen < 4)
- return -1;
- dest[0] = (q->qtype & 0xff00) >> 8;
- dest[1] = (q->qtype & 0x00ff) >> 0;
- dest[2] = (q->qclass & 0xff00) >> 8;
- dest[3] = (q->qclass & 0x00ff) >> 0;
- return i + 4;
- }
- #endif
- #ifdef L_decodeq
- int attribute_hidden __decode_question(const unsigned char * const message, int offset,
- struct resolv_question *q)
- {
- char temp[256];
- int i;
- i = __decode_dotted(message, offset, temp, sizeof(temp));
- if (i < 0)
- return i;
- offset += i;
- //TODO: what if strdup fails?
- q->dotted = strdup(temp);
- q->qtype = (message[offset + 0] << 8) | message[offset + 1];
- q->qclass = (message[offset + 2] << 8) | message[offset + 3];
- return i + 4;
- }
- #endif
- #ifdef L_lengthq
- /* Returns -1 only if message == NULL */
- int attribute_hidden __length_question(const unsigned char * const message, int offset)
- {
- int i;
- /* returns -1 only if message == NULL */
- i = __length_dotted(message, offset);
- if (i < 0)
- return i;
- return i + 4;
- }
- #endif
- #ifdef L_encodea
- int attribute_hidden __encode_answer(struct resolv_answer *a, unsigned char *dest, int maxlen)
- {
- int i;
- i = __encode_dotted(a->dotted, dest, maxlen);
- if (i < 0)
- return i;
- dest += i;
- maxlen -= i;
- if (maxlen < (RRFIXEDSZ + a->rdlength))
- return -1;
- *dest++ = (a->atype & 0xff00) >> 8;
- *dest++ = (a->atype & 0x00ff) >> 0;
- *dest++ = (a->aclass & 0xff00) >> 8;
- *dest++ = (a->aclass & 0x00ff) >> 0;
- *dest++ = (a->ttl & 0xff000000) >> 24;
- *dest++ = (a->ttl & 0x00ff0000) >> 16;
- *dest++ = (a->ttl & 0x0000ff00) >> 8;
- *dest++ = (a->ttl & 0x000000ff) >> 0;
- *dest++ = (a->rdlength & 0xff00) >> 8;
- *dest++ = (a->rdlength & 0x00ff) >> 0;
- memcpy(dest, a->rdata, a->rdlength);
- return i + RRFIXEDSZ + a->rdlength;
- }
- #endif
- #ifdef L_decodea
- int attribute_hidden __decode_answer(const unsigned char *message, int offset,
- int len, struct resolv_answer *a)
- {
- char temp[256];
- int i;
- DPRINTF("decode_answer(start): off %d, len %d\n", offset, len);
- i = __decode_dotted(message, offset, temp, sizeof(temp));
- if (i < 0)
- return i;
- message += offset + i;
- len -= i + RRFIXEDSZ + offset;
- if (len < 0) {
- DPRINTF("decode_answer: off %d, len %d, i %d\n", offset, len, i);
- return len;
- }
- // TODO: what if strdup fails?
- a->dotted = strdup(temp);
- a->atype = (message[0] << 8) | message[1];
- message += 2;
- a->aclass = (message[0] << 8) | message[1];
- message += 2;
- a->ttl = (message[0] << 24) |
- (message[1] << 16) | (message[2] << 8) | (message[3] << 0);
- message += 4;
- a->rdlength = (message[0] << 8) | message[1];
- message += 2;
- a->rdata = message;
- a->rdoffset = offset + i + RRFIXEDSZ;
- DPRINTF("i=%d,rdlength=%d\n", i, a->rdlength);
- if (len < a->rdlength)
- return -1;
- return i + RRFIXEDSZ + a->rdlength;
- }
- #endif
- #ifdef CURRENTLY_UNUSED
- #ifdef L_encodep
- int __encode_packet(struct resolv_header *h,
- struct resolv_question **q,
- struct resolv_answer **an,
- struct resolv_answer **ns,
- struct resolv_answer **ar,
- unsigned char *dest, int maxlen) attribute_hidden;
- int __encode_packet(struct resolv_header *h,
- struct resolv_question **q,
- struct resolv_answer **an,
- struct resolv_answer **ns,
- struct resolv_answer **ar,
- unsigned char *dest, int maxlen)
- {
- int i, total = 0;
- unsigned j;
- i = __encode_header(h, dest, maxlen);
- if (i < 0)
- return i;
- dest += i;
- maxlen -= i;
- total += i;
- for (j = 0; j < h->qdcount; j++) {
- i = __encode_question(q[j], dest, maxlen);
- if (i < 0)
- return i;
- dest += i;
- maxlen -= i;
- total += i;
- }
- for (j = 0; j < h->ancount; j++) {
- i = __encode_answer(an[j], dest, maxlen);
- if (i < 0)
- return i;
- dest += i;
- maxlen -= i;
- total += i;
- }
- for (j = 0; j < h->nscount; j++) {
- i = __encode_answer(ns[j], dest, maxlen);
- if (i < 0)
- return i;
- dest += i;
- maxlen -= i;
- total += i;
- }
- for (j = 0; j < h->arcount; j++) {
- i = __encode_answer(ar[j], dest, maxlen);
- if (i < 0)
- return i;
- dest += i;
- maxlen -= i;
- total += i;
- }
- return total;
- }
- #endif
- #ifdef L_decodep
- int __decode_packet(unsigned char *data, struct resolv_header *h) attribute_hidden;
- int __decode_packet(unsigned char *data, struct resolv_header *h)
- {
- __decode_header(data, h);
- return HFIXEDSZ;
- }
- #endif
- #ifdef L_formquery
- int __form_query(int id, const char *name, int type, unsigned char *packet, int maxlen);
- int __form_query(int id, const char *name, int type, unsigned char *packet,
- int maxlen)
- {
- struct resolv_header h;
- struct resolv_question q;
- int i, j;
- memset(&h, 0, sizeof(h));
- h.id = id;
- h.qdcount = 1;
- q.dotted = (char *) name;
- q.qtype = type;
- q.qclass = C_IN; /* CLASS_IN */
- i = __encode_header(&h, packet, maxlen);
- if (i < 0)
- return i;
- j = __encode_question(&q, packet + i, maxlen - i);
- if (j < 0)
- return j;
- return i + j;
- }
- #endif
- #endif /* CURRENTLY_UNUSED */
- #ifdef L_opennameservers
- # if __BYTE_ORDER == __LITTLE_ENDIAN
- #define NAMESERVER_PORT_N (__bswap_constant_16(NAMESERVER_PORT))
- #else
- #define NAMESERVER_PORT_N NAMESERVER_PORT
- #endif
- __UCLIBC_MUTEX_INIT(__resolv_lock, PTHREAD_MUTEX_INITIALIZER);
- /* Protected by __resolv_lock */
- void (*__res_sync)(void);
- //uint32_t __resolv_opts;
- unsigned __nameservers;
- unsigned __searchdomains;
- sockaddr46_t *__nameserver;
- char **__searchdomain;
- #ifdef __UCLIBC_HAS_IPV4__
- const struct sockaddr_in __local_nameserver = {
- .sin_family = AF_INET,
- .sin_port = NAMESERVER_PORT_N,
- };
- #else
- const struct sockaddr_in6 __local_nameserver = {
- .sin6_family = AF_INET6,
- .sin6_port = NAMESERVER_PORT_N,
- };
- #endif
- /* Helpers. Both stop on EOL, if it's '\n', it is converted to NUL first */
- static char *skip_nospace(char *p)
- {
- while (*p != '\0' && !isspace(*p)) {
- if (*p == '\n') {
- *p = '\0';
- break;
- }
- p++;
- }
- return p;
- }
- static char *skip_and_NUL_space(char *p)
- {
- /* NB: '\n' is not isspace! */
- while (1) {
- char c = *p;
- if (c == '\0' || !isspace(c))
- break;
- *p = '\0';
- if (c == '\n' || c == '#')
- break;
- p++;
- }
- return p;
- }
- /* Must be called under __resolv_lock. */
- void attribute_hidden __open_nameservers(void)
- {
- char szBuffer[MAXLEN_searchdomain];
- FILE *fp;
- int i;
- sockaddr46_t sa;
- //if (!__res_sync && last_time_was_long_ago)
- // __close_nameservers(); /* force config reread */
- if (__nameservers)
- goto sync;
- fp = fopen("/etc/resolv.conf", "r");
- if (!fp) {
- // TODO: why? google says nothing about this...
- fp = fopen("/etc/config/resolv.conf", "r");
- }
- if (fp) {
- while (fgets(szBuffer, sizeof(szBuffer), fp) != NULL) {
- void *ptr;
- char *keyword, *p;
- keyword = p = skip_and_NUL_space(szBuffer);
- /* skip keyword */
- p = skip_nospace(p);
- /* find next word */
- p = skip_and_NUL_space(p);
- if (strcmp(keyword, "nameserver") == 0) {
- /* terminate IP addr */
- *skip_nospace(p) = '\0';
- memset(&sa, 0, sizeof(sa));
- if (0) /* nothing */;
- #ifdef __UCLIBC_HAS_IPV6__
- else if (inet_pton(AF_INET6, p, &sa.sa6.sin6_addr) > 0) {
- sa.sa6.sin6_family = AF_INET6;
- sa.sa6.sin6_port = htons(NAMESERVER_PORT);
- }
- #endif
- #ifdef __UCLIBC_HAS_IPV4__
- else if (inet_pton(AF_INET, p, &sa.sa4.sin_addr) > 0) {
- sa.sa4.sin_family = AF_INET;
- sa.sa4.sin_port = htons(NAMESERVER_PORT);
- }
- #endif
- else
- continue; /* garbage on this line */
- ptr = realloc(__nameserver, (__nameservers + 1) * sizeof(__nameserver[0]));
- if (!ptr)
- continue;
- __nameserver = ptr;
- __nameserver[__nameservers++] = sa; /* struct copy */
- continue;
- }
- if (strcmp(keyword, "domain") == 0 || strcmp(keyword, "search") == 0) {
- char *p1;
- /* free old domains ("last 'domain' or 'search' wins" rule) */
- while (__searchdomains)
- free(__searchdomain[--__searchdomains]);
- /*free(__searchdomain);*/
- /*__searchdomain = NULL; - not necessary */
- next_word:
- /* terminate current word */
- p1 = skip_nospace(p);
- /* find next word (maybe) */
- p1 = skip_and_NUL_space(p1);
- /* add it */
- ptr = realloc(__searchdomain, (__searchdomains + 1) * sizeof(__searchdomain[0]));
- if (!ptr)
- continue;
- __searchdomain = ptr;
- /* NB: strlen(p) <= MAXLEN_searchdomain) because szBuffer[] is smaller */
- ptr = strdup(p);
- if (!ptr)
- continue;
- DPRINTF("adding search %s\n", (char*)ptr);
- __searchdomain[__searchdomains++] = (char*)ptr;
- p = p1;
- if (*p)
- goto next_word;
- continue;
- }
- /* if (strcmp(keyword, "sortlist") == 0)... */
- /* if (strcmp(keyword, "options") == 0)... */
- }
- fclose(fp);
- }
- if (__nameservers == 0) {
- /* Have to handle malloc failure! What a mess...
- * And it's not only here, we need to be careful
- * to never write into __nameserver[0] if it points
- * to constant __local_nameserver, or free it. */
- __nameserver = malloc(sizeof(__nameserver[0]));
- if (__nameserver)
- memcpy(__nameserver, &__local_nameserver, sizeof(__local_nameserver));
- else
- __nameserver = (void*) &__local_nameserver;
- __nameservers++;
- }
- if (__searchdomains == 0) {
- char buf[256];
- char *p;
- i = gethostname(buf, sizeof(buf) - 1);
- buf[sizeof(buf) - 1] = '\0';
- if (i == 0 && (p = strchr(buf, '.')) != NULL && p[1]) {
- p = strdup(p + 1);
- if (!p)
- goto err;
- __searchdomain = malloc(sizeof(__searchdomain[0]));
- if (!__searchdomain) {
- free(p);
- goto err;
- }
- __searchdomain[0] = p;
- __searchdomains++;
- err: ;
- }
- }
- DPRINTF("nameservers = %d\n", __nameservers);
- sync:
- if (__res_sync)
- __res_sync();
- }
- #endif
- #ifdef L_closenameservers
- /* Must be called under __resolv_lock. */
- void attribute_hidden __close_nameservers(void)
- {
- if (__nameserver != (void*) &__local_nameserver)
- free(__nameserver);
- __nameserver = NULL;
- __nameservers = 0;
- while (__searchdomains)
- free(__searchdomain[--__searchdomains]);
- free(__searchdomain);
- __searchdomain = NULL;
- /*__searchdomains = 0; - already is */
- }
- #endif
- #ifdef L_dnslookup
- /* On entry:
- * a.buf(len) = auxiliary buffer for IP addresses after first one
- * a.add_count = how many additional addresses are there already
- * outpacket = where to save ptr to raw packet? can be NULL
- * On exit:
- * ret < 0: error, all other data is not valid
- * a.add_count & a.buf: updated
- * a.rdlength: length of addresses (4 bytes for IPv4)
- * *outpacket: updated (packet is malloced, you need to free it)
- * a.rdata: points into *outpacket to 1st IP addr
- * NB: don't pass outpacket == NULL if you need to use a.rdata!
- * a.atype: type of query?
- * a.dotted: which name we _actually_ used. May contain search domains
- * appended. (why the filed is called "dotted" I have no idea)
- * This is a malloced string. May be NULL because strdup failed.
- */
- int attribute_hidden __dns_lookup(const char *name, int type,
- unsigned char **outpacket,
- struct resolv_answer *a)
- {
- /* Protected by __resolv_lock: */
- static int last_ns_num = 0;
- static uint16_t last_id = 1;
- int i, j, len, fd, pos, rc;
- int name_len;
- #ifdef USE_SELECT
- struct timeval tv;
- fd_set fds;
- #else
- struct pollfd fds;
- #endif
- struct resolv_header h;
- struct resolv_question q;
- struct resolv_answer ma;
- bool first_answer = 1;
- int retries_left;
- unsigned char *packet = malloc(PACKETSZ);
- char *lookup;
- int variant = -1; /* search domain to append, -1: none */
- int local_ns_num = -1; /* Nth server to use */
- int local_id = local_id; /* for compiler */
- int sdomains;
- bool ends_with_dot;
- sockaddr46_t sa;
- fd = -1;
- lookup = NULL;
- name_len = strlen(name);
- if ((unsigned)name_len >= MAXDNAME - MAXLEN_searchdomain - 2)
- goto fail; /* paranoia */
- lookup = malloc(name_len + 1/*for '.'*/ + MAXLEN_searchdomain + 1);
- if (!packet || !lookup || !name[0])
- goto fail;
- ends_with_dot = (name[name_len - 1] == '.');
- /* no strcpy! paranoia, user might change name[] under us */
- memcpy(lookup, name, name_len);
- DPRINTF("Looking up type %d answer for '%s'\n", type, name);
- retries_left = 0; /* for compiler */
- do {
- unsigned reply_timeout;
- if (fd != -1) {
- close(fd);
- fd = -1;
- }
- /* Mess with globals while under lock */
- /* NB: even data *pointed to* by globals may vanish
- * outside the locks. We should assume any and all
- * globals can completely change between locked
- * code regions. OTOH, this is rare, so we don't need
- * to handle it "nicely" (do not skip servers,
- * search domains, etc), we only need to ensure
- * we do not SEGV, use freed+overwritten data
- * or do other Really Bad Things. */
- __UCLIBC_MUTEX_LOCK(__resolv_lock);
- __open_nameservers();
- sdomains = __searchdomains;
- lookup[name_len] = '\0';
- if ((unsigned)variant < sdomains) {
- /* lookup is name_len + 1 + MAXLEN_searchdomain + 1 long */
- /* __searchdomain[] is not bigger than MAXLEN_searchdomain */
- lookup[name_len] = '.';
- strcpy(&lookup[name_len + 1], __searchdomain[variant]);
- }
- /* first time? pick starting server etc */
- if (local_ns_num < 0) {
- local_id = last_id;
- //TODO: implement /etc/resolv.conf's "options rotate"
- // (a.k.a. RES_ROTATE bit in _res.options)
- // local_ns_num = 0;
- // if (_res.options & RES_ROTATE)
- local_ns_num = last_ns_num;
- //TODO: use _res.retry
- retries_left = __nameservers * RES_DFLRETRY;
- }
- retries_left--;
- if (local_ns_num >= __nameservers)
- local_ns_num = 0;
- local_id++;
- local_id &= 0xffff;
- /* write new values back while still under lock */
- last_id = local_id;
- last_ns_num = local_ns_num;
- /* struct copy */
- /* can't just take a pointer, __nameserver[x]
- * is not safe to use outside of locks */
- sa = __nameserver[local_ns_num];
- __UCLIBC_MUTEX_UNLOCK(__resolv_lock);
- memset(packet, 0, PACKETSZ);
- memset(&h, 0, sizeof(h));
- /* encode header */
- h.id = local_id;
- h.qdcount = 1;
- h.rd = 1;
- DPRINTF("encoding header\n", h.rd);
- i = __encode_header(&h, packet, PACKETSZ);
- if (i < 0)
- goto fail;
- /* encode question */
- DPRINTF("lookup name: %s\n", lookup);
- q.dotted = lookup;
- q.qtype = type;
- q.qclass = C_IN; /* CLASS_IN */
- j = __encode_question(&q, packet+i, PACKETSZ-i);
- if (j < 0)
- goto fail;
- len = i + j;
- /* send packet */
- DPRINTF("On try %d, sending query to port %d\n",
- retries_left, NAMESERVER_PORT);
- fd = socket(sa.sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
- if (fd < 0) /* paranoia */
- goto try_next_server;
- rc = connect(fd, &sa.sa, sizeof(sa));
- if (rc < 0) {
- //if (errno == ENETUNREACH) {
- /* routing error, presume not transient */
- goto try_next_server;
- //}
- //For example, what transient error this can be? Can't think of any
- ///* retry */
- //continue;
- }
- DPRINTF("Xmit packet len:%d id:%d qr:%d\n", len, h.id, h.qr);
- /* no error check - if it fails, we time out on recv */
- send(fd, packet, len, 0);
- #ifdef USE_SELECT
- //TODO: use _res.retrans
- reply_timeout = RES_TIMEOUT;
- wait_again:
- FD_ZERO(&fds);
- FD_SET(fd, &fds);
- tv.tv_sec = reply_timeout;
- tv.tv_usec = 0;
- if (select(fd + 1, &fds, NULL, NULL, &tv) <= 0) {
- DPRINTF("Timeout\n");
- /* timed out, so retry send and receive
- * to next nameserver */
- goto try_next_server;
- }
- reply_timeout--;
- #else
- reply_timeout = RES_TIMEOUT * 1000;
- wait_again:
- fds.fd = fd;
- fds.events = POLLIN;
- if (poll(&fds, 1, reply_timeout) <= 0) {
- DPRINTF("Timeout\n");
- /* timed out, so retry send and receive
- * to next nameserver */
- goto try_next_server;
- }
- //TODO: better timeout accounting?
- reply_timeout -= 1000;
- #endif
- len = recv(fd, packet, PACKETSZ, MSG_DONTWAIT);
- if (len < HFIXEDSZ) {
- /* too short!
- * it's just a bogus packet from somewhere */
- bogus_packet:
- if (reply_timeout)
- goto wait_again;
- goto try_next_server;
- }
- __decode_header(packet, &h);
- DPRINTF("id = %d, qr = %d\n", h.id, h.qr);
- if (h.id != local_id || !h.qr) {
- /* unsolicited */
- goto bogus_packet;
- }
- DPRINTF("Got response (i think)!\n");
- DPRINTF("qrcount=%d,ancount=%d,nscount=%d,arcount=%d\n",
- h.qdcount, h.ancount, h.nscount, h.arcount);
- DPRINTF("opcode=%d,aa=%d,tc=%d,rd=%d,ra=%d,rcode=%d\n",
- h.opcode, h.aa, h.tc, h.rd, h.ra, h.rcode);
- /* bug 660 says we treat negative response as an error
- * and retry, which is, eh, an error. :)
- * We were incurring long delays because of this. */
- if (h.rcode == NXDOMAIN) {
- /* if possible, try next search domain */
- if (!ends_with_dot) {
- DPRINTF("variant:%d sdomains:%d\n", variant, sdomains);
- if (variant < sdomains - 1) {
- /* next search domain */
- variant++;
- continue;
- }
- /* no more search domains to try */
- }
- /* dont loop, this is "no such host" situation */
- h_errno = HOST_NOT_FOUND;
- goto fail1;
- }
- if (h.rcode != 0) /* error */
- goto try_next_sdomain;
- /* code below won't work correctly with h.ancount == 0, so... */
- if (h.ancount <= 0) {
- h_errno = NO_DATA; /* is this correct code? */
- goto fail1;
- }
- pos = HFIXEDSZ;
- for (j = 0; j < h.qdcount; j++) {
- DPRINTF("Skipping question %d at %d\n", j, pos);
- /* returns -1 only if packet == NULL (can't happen) */
- i = __length_question(packet, pos);
- DPRINTF("Length of question %d is %d\n", j, i);
- pos += i;
- }
- DPRINTF("Decoding answer at pos %d\n", pos);
- first_answer = 1;
- for (j = 0; j < h.ancount && pos < len; j++) {
- i = __decode_answer(packet, pos, len, &ma);
- if (i < 0) {
- DPRINTF("failed decode %d\n", i);
- /* if the message was truncated and we have
- * decoded some answers, pretend it's OK */
- if (j && h.tc)
- break;
- goto try_next_sdomain;
- }
- pos += i;
- if (first_answer) {
- ma.buf = a->buf;
- ma.buflen = a->buflen;
- ma.add_count = a->add_count;
- memcpy(a, &ma, sizeof(ma));
- if (a->atype != T_SIG && (NULL == a->buf || (type != T_A && type != T_AAAA)))
- break;
- if (a->atype != type) {
- free(a->dotted);
- continue;
- }
- a->add_count = h.ancount - j - 1;
- if ((a->rdlength + sizeof(struct in_addr*)) * a->add_count > a->buflen)
- break;
- a->add_count = 0;
- first_answer = 0;
- } else {
- free(ma.dotted);
- if (ma.atype != type)
- continue;
- if (a->rdlength != ma.rdlength) {
- free(a->dotted);
- DPRINTF("Answer address len(%u) differs from original(%u)\n",
- ma.rdlength, a->rdlength);
- goto try_next_sdomain;
- }
- memcpy(a->buf + (a->add_count * ma.rdlength), ma.rdata, ma.rdlength);
- ++a->add_count;
- }
- }
- /* success! */
- DPRINTF("Answer name = |%s|\n", a->dotted);
- DPRINTF("Answer type = |%d|\n", a->atype);
- if (fd != -1)
- close(fd);
- if (outpacket)
- *outpacket = packet;
- else
- free(packet);
- free(lookup);
- return len;
- //TODO: audit whether *any* "goto try_next_sdomain" is actually correct:
- //trying next search domain makes sense only if we got NXDOMAIN!
- //why we do it in other cases too?
- try_next_sdomain:
- /* if there are searchdomains, try them */
- if (!ends_with_dot) {
- if (variant < sdomains - 1) {
- /* next search */
- variant++;
- continue;
- }
- }
- try_next_server:
- /* if there are other nameservers, try them */
- local_ns_num++;
- variant = -1;
- } while (retries_left > 0);
- fail:
- h_errno = NETDB_INTERNAL;
- fail1:
- if (fd != -1)
- close(fd);
- free(lookup);
- free(packet);
- return -1;
- }
- #endif
- #ifdef L_read_etc_hosts_r
- FILE * __open_etc_hosts(void)
- {
- FILE * fp;
- if ((fp = fopen("/etc/hosts", "r")) == NULL) {
- fp = fopen("/etc/config/hosts", "r");
- }
- return fp;
- }
- int attribute_hidden __read_etc_hosts_r(
- FILE * fp,
- const char * name,
- int type,
- enum etc_hosts_action action,
- struct hostent * result_buf,
- char * buf, size_t buflen,
- struct hostent ** result,
- int * h_errnop)
- {
- struct in_addr *in = NULL;
- struct in_addr **addr_list = NULL;
- #ifdef __UCLIBC_HAS_IPV6__
- struct in6_addr *in6 = NULL;
- struct in6_addr **addr_list6 = NULL;
- #endif /* __UCLIBC_HAS_IPV6__ */
- char *cp, **alias;
- int aliases, i, ret = HOST_NOT_FOUND;
- /* make sure user char * is aligned */
- i = ALIGN_BUFFER_OFFSET(buf);
- buf += i;
- buflen -= i;
- alias = (char **)buf;
- buf += sizeof(char **) * ALIAS_DIM;
- buflen -= sizeof(char **) * ALIAS_DIM;
- if ((ssize_t)buflen < 0)
- return ERANGE;
- if (action != GETHOSTENT) {
- #ifdef __UCLIBC_HAS_IPV6__
- char *p = buf;
- size_t len = buflen;
- #endif
- *h_errnop = NETDB_INTERNAL;
- in = (struct in_addr*)buf;
- buf += sizeof(*in);
- buflen -= sizeof(*in);
- addr_list = (struct in_addr **)buf;
- buf += sizeof(*addr_list) * 2;
- buflen -= sizeof(*addr_list) * 2;
- if ((ssize_t)buflen < 0)
- return ERANGE;
- #ifdef __UCLIBC_HAS_IPV6__
- in6 = (struct in6_addr*)p;
- p += sizeof(*in6);
- len -= sizeof(*in6);
- addr_list6 = (struct in6_addr**)p;
- p += sizeof(*addr_list6) * 2;
- len -= sizeof(*addr_list6) * 2;
- if ((ssize_t)len < 0)
- return ERANGE;
- if (len < buflen) {
- buflen = len;
- buf = p;
- }
- #endif
- if ((ssize_t)buflen < 80)
- return ERANGE;
- fp = __open_etc_hosts();
- if (fp == NULL) {
- *result = NULL;
- return errno;
- }
- }
- *h_errnop = HOST_NOT_FOUND;
- while (fgets(buf, buflen, fp)) {
- cp = strchr(buf, '#');
- if (cp)
- *cp = '\0';
- DPRINTF("Looking at: %s\n", buf);
- aliases = 0;
- cp = buf;
- while (*cp) {
- while (*cp && isspace(*cp))
- *cp++ = '\0';
- if (!*cp)
- break;
- if (aliases < (2+MAX_ALIASES))
- alias[aliases++] = cp;
- while (*cp && !isspace(*cp))
- cp++;
- }
- alias[aliases] = NULL;
- if (aliases < 2)
- continue; /* syntax error really */
- if (action == GETHOSTENT) {
- /* Return whatever the next entry happens to be. */
- break;
- }
- if (action == GET_HOSTS_BYADDR) {
- if (strcmp(name, alias[0]) != 0)
- continue;
- } else {
- /* GET_HOSTS_BYNAME */
- for (i = 1; i < aliases; i++)
- if (strcasecmp(name, alias[i]) == 0)
- break;
- if (i >= aliases)
- continue;
- }
- if (type == AF_INET && inet_pton(AF_INET, alias[0], in) > 0) {
- DPRINTF("Found INET\n");
- addr_list[0] = in;
- addr_list[1] = NULL;
- result_buf->h_name = alias[1];
- result_buf->h_addrtype = AF_INET;
- result_buf->h_length = sizeof(*in);
- result_buf->h_addr_list = (char**) addr_list;
- result_buf->h_aliases = alias + 2;
- *result = result_buf;
- ret = NETDB_SUCCESS;
- }
- #ifdef __UCLIBC_HAS_IPV6__
- else if (type == AF_INET6 && inet_pton(AF_INET6, alias[0], in6) > 0) {
- DPRINTF("Found INET6\n");
- addr_list6[0] = in6;
- addr_list6[1] = NULL;
- result_buf->h_name = alias[1];
- result_buf->h_addrtype = AF_INET6;
- result_buf->h_length = sizeof(*in6);
- result_buf->h_addr_list = (char**) addr_list6;
- result_buf->h_aliases = alias + 2;
- *result = result_buf;
- ret = NETDB_SUCCESS;
- }
- #endif
- else {
- /* continue parsing in the hope the user has multiple
- * host types listed in the database like so:
- * <ipv4 addr> host
- * <ipv6 addr> host
- * If looking for an IPv6 addr, don't bail when we got the IPv4
- */
- DPRINTF("Error: Found host but diff network type\n");
- /* NB: gethostbyname2_r depends on this feature
- * to avoid looking for IPv6 addr of "localhost" etc */
- ret = TRY_AGAIN;
- continue;
- }
- break;
- }
- if (action != GETHOSTENT)
- fclose(fp);
- return ret;
- }
- #endif
- #ifdef L_get_hosts_byname_r
- int attribute_hidden __get_hosts_byname_r(const char * name, int type,
- struct hostent * result_buf,
- char * buf, size_t buflen,
- struct hostent ** result,
- int * h_errnop)
- {
- return __read_etc_hosts_r(NULL, name, type, GET_HOSTS_BYNAME,
- result_buf, buf, buflen, result, h_errnop);
- }
- #endif
- #ifdef L_get_hosts_byaddr_r
- int attribute_hidden __get_hosts_byaddr_r(const char * addr, int len, int type,
- struct hostent * result_buf,
- char * buf, size_t buflen,
- struct hostent ** result,
- int * h_errnop)
- {
- #ifndef __UCLIBC_HAS_IPV6__
- char ipaddr[INET_ADDRSTRLEN];
- #else
- char ipaddr[INET6_ADDRSTRLEN];
- #endif /* __UCLIBC_HAS_IPV6__ */
- switch (type) {
- case AF_INET:
- if (len != sizeof(struct in_addr))
- return 0;
- break;
- #ifdef __UCLIBC_HAS_IPV6__
- case AF_INET6:
- if (len != sizeof(struct in6_addr))
- return 0;
- break;
- #endif /* __UCLIBC_HAS_IPV6__ */
- default:
- return 0;
- }
- inet_ntop(type, addr, ipaddr, sizeof(ipaddr));
- return __read_etc_hosts_r(NULL, ipaddr, type, GET_HOSTS_BYADDR,
- result_buf, buf, buflen, result, h_errnop);
- }
- #endif
- #ifdef L_getnameinfo
- int getnameinfo(const struct sockaddr *sa, socklen_t addrlen, char *host,
- socklen_t hostlen, char *serv, socklen_t servlen,
- unsigned int flags)
- {
- int serrno = errno;
- unsigned ok;
- struct hostent *h = NULL;
- char domain[256];
- if (flags & ~(NI_NUMERICHOST|NI_NUMERICSERV|NI_NOFQDN|NI_NAMEREQD|NI_DGRAM))
- return EAI_BADFLAGS;
- if (sa == NULL || addrlen < sizeof(sa_family_t))
- goto BAD_FAM;
- ok = sa->sa_family;
- if (ok == AF_LOCAL) /* valid */;
- #ifdef __UCLIBC_HAS_IPV4__
- else if (ok == AF_INET) {
- if (addrlen < sizeof(struct sockaddr_in))
- goto BAD_FAM;
- }
- #endif
- #ifdef __UCLIBC_HAS_IPV6__
- else if (ok == AF_INET6) {
- if (addrlen < sizeof(struct sockaddr_in6))
- goto BAD_FAM;
- }
- #endif /* __UCLIBC_HAS_IPV6__ */
- else
- BAD_FAM:
- return EAI_FAMILY;
- ok = 0;
- if (host != NULL && hostlen > 0)
- switch (sa->sa_family) {
- case AF_INET:
- #ifdef __UCLIBC_HAS_IPV6__
- case AF_INET6:
- #endif
- if (!(flags & NI_NUMERICHOST)) {
- if (0) /* nothing */;
- #ifdef __UCLIBC_HAS_IPV6__
- else if (sa->sa_family == AF_INET6)
- h = gethostbyaddr((const void *)
- &(((const struct sockaddr_in6 *) sa)->sin6_addr),
- sizeof(struct in6_addr), AF_INET6);
- #endif
- #ifdef __UCLIBC_HAS_IPV4__
- else
- h = gethostbyaddr((const void *)
- &(((const struct sockaddr_in *)sa)->sin_addr),
- sizeof(struct in_addr), AF_INET);
- #endif
- if (h) {
- char *c;
- #undef min
- #define min(x,y) (((x) > (y)) ? (y) : (x))
- if ((flags & NI_NOFQDN)
- && (__libc_getdomainname(domain, sizeof(domain)) == 0)
- && (c = strstr(h->h_name, domain)) != NULL
- && (c != h->h_name) && (*(--c) == '.')
- ) {
- strncpy(host, h->h_name,
- min(hostlen, (size_t) (c - h->h_name)));
- host[min(hostlen - 1, (size_t) (c - h->h_name))] = '\0';
- } else {
- strncpy(host, h->h_name, hostlen);
- }
- ok = 1;
- #undef min
- }
- }
- if (!ok) {
- const char *c = NULL;
- if (flags & NI_NAMEREQD) {
- errno = serrno;
- return EAI_NONAME;
- }
- if (0) /* nothing */;
- #ifdef __UCLIBC_HAS_IPV6__
- else if (sa->sa_family == AF_INET6) {
- const struct sockaddr_in6 *sin6p;
- sin6p = (const struct sockaddr_in6 *) sa;
- c = inet_ntop(AF_INET6,
- (const void *) &sin6p->sin6_addr,
- host, hostlen);
- #if 0
- /* Does scope id need to be supported? */
- uint32_t scopeid;
- scopeid = sin6p->sin6_scope_id;
- if (scopeid != 0) {
- /* Buffer is >= IFNAMSIZ+1. */
- char scopebuf[IFNAMSIZ + 1];
- char *scopeptr;
- int ni_numericscope = 0;
- size_t real_hostlen = strnlen(host, hostlen);
- size_t scopelen = 0;
- scopebuf[0] = SCOPE_DELIMITER;
- scopebuf[1] = '\0';
- scopeptr = &scopebuf[1];
- if (IN6_IS_ADDR_LINKLOCAL(&sin6p->sin6_addr)
- || IN6_IS_ADDR_MC_LINKLOCAL(&sin6p->sin6_addr)) {
- if (if_indextoname(scopeid, scopeptr) == NULL)
- ++ni_numericscope;
- else
- scopelen = strlen(scopebuf);
- } else {
- ++ni_numericscope;
- }
- if (ni_numericscope)
- scopelen = 1 + snprintf(scopeptr,
- (scopebuf
- + sizeof scopebuf
- - scopeptr),
- "%u", scopeid);
- if (real_hostlen + scopelen + 1 > hostlen)
- return EAI_SYSTEM;
- memcpy(host + real_hostlen, scopebuf, scopelen + 1);
- }
- #endif
- }
- #endif /* __UCLIBC_HAS_IPV6__ */
- #if defined __UCLIBC_HAS_IPV4__
- else {
- c = inet_ntop(AF_INET, (const void *)
- &(((const struct sockaddr_in *) sa)->sin_addr),
- host, hostlen);
- }
- #endif
- if (c == NULL) {
- errno = serrno;
- return EAI_SYSTEM;
- }
- ok = 1;
- }
- break;
- case AF_LOCAL:
- if (!(flags & NI_NUMERICHOST)) {
- struct utsname utsname;
- if (!uname(&utsname)) {
- strncpy(host, utsname.nodename, hostlen);
- break;
- };
- };
- if (flags & NI_NAMEREQD) {
- errno = serrno;
- return EAI_NONAME;
- }
- strncpy(host, "localhost", hostlen);
- break;
- /* Already checked above
- default:
- return EAI_FAMILY;
- */
- }
- if (serv && (servlen > 0)) {
- if (sa->sa_family == AF_LOCAL) {
- strncpy(serv, ((const struct sockaddr_un *) sa)->sun_path, servlen);
- } else { /* AF_INET || AF_INET6 */
- if (!(flags & NI_NUMERICSERV)) {
- struct servent *s;
- s = getservbyport(((const struct sockaddr_in *) sa)->sin_port,
- ((flags & NI_DGRAM) ? "udp" : "tcp"));
- if (s) {
- strncpy(serv, s->s_name, servlen);
- goto DONE;
- }
- }
- snprintf(serv, servlen, "%d",
- ntohs(((const struct sockaddr_in *) sa)->sin_port));
- }
- }
- DONE:
- if (host && (hostlen > 0))
- host[hostlen-1] = 0;
- if (serv && (servlen > 0))
- serv[servlen-1] = 0;
- errno = serrno;
- return 0;
- }
- libc_hidden_def(getnameinfo)
- #endif
- #ifdef L_gethostbyname_r
- /* Bug 671 says:
- * "uClibc resolver's gethostbyname does not return the requested name
- * as an alias, but instead returns the canonical name. glibc's
- * gethostbyname has a similar bug where it returns the requested name
- * with the search domain name appended (to make a FQDN) as an alias,
- * but not the original name itself. Both contradict POSIX, which says
- * that the name argument passed to gethostbyname must be in the alias list"
- * This is fixed now, and we differ from glibc:
- *
- * $ ./gethostbyname_uclibc wer.google.com
- * h_name:'c13-ss-2-lb.cnet.com'
- * h_length:4
- * h_addrtype:2 AF_INET
- * alias:'wer.google.com' <===
- * addr: 0x4174efd8 '216.239.116.65'
- *
- * $ ./gethostbyname_glibc wer.google.com
- * h_name:'c13-ss-2-lb.cnet.com'
- * h_length:4
- * h_addrtype:2 AF_INET
- * alias:'wer.google.com.com' <===
- * addr:'216.239.116.65'
- *
- * When examples were run, /etc/resolv.conf contained "search com" line.
- */
- int gethostbyname_r(const char * name,
- struct hostent * result_buf,
- char * buf,
- size_t buflen,
- struct hostent ** result,
- int * h_errnop)
- {
- struct in_addr **addr_list;
- char **alias;
- char *alias0;
- unsigned char *packet;
- struct resolv_answer a;
- int i;
- int wrong_af = 0;
- *result = NULL;
- if (!name)
- return EINVAL;
- /* do /etc/hosts first */
- {
- int old_errno = errno; /* save the old errno and reset errno */
- __set_errno(0); /* to check for missing /etc/hosts. */
- i = __get_hosts_byname_r(name, AF_INET, result_buf,
- buf, buflen, result, h_errnop);
- if (i == NETDB_SUCCESS) {
- __set_errno(old_errno);
- return i;
- }
- switch (*h_errnop) {
- case HOST_NOT_FOUND:
- wrong_af = (i == TRY_AGAIN);
- case NO_ADDRESS:
- break;
- case NETDB_INTERNAL:
- if (errno == ENOENT) {
- break;
- }
- /* else fall through */
- default:
- return i;
- }
- __set_errno(old_errno);
- }
- DPRINTF("Nothing found in /etc/hosts\n");
- *h_errnop = NETDB_INTERNAL;
- /* prepare future h_aliases[0] */
- i = strlen(name) + 1;
- if ((ssize_t)buflen <= i)
- return ERANGE;
- strcpy(buf, name);
- alias0 = buf;
- buf += i;
- buflen -= i;
- /* make sure pointer is aligned */
- i = ALIGN_BUFFER_OFFSET(buf);
- buf += i;
- buflen -= i;
- alias = (char **)buf;
- buf += sizeof(alias[0]) * 2;
- buflen -= sizeof(alias[0]) * 2;
- addr_list = (struct in_addr **)buf;
- /* do not use *buf or buflen before this verification! */
- /* buflen may be < 0, must do signed compare */
- if ((ssize_t)buflen < 256)
- return ERANGE;
- /* we store only one "alias" - the name itself */
- #ifdef __UCLIBC_MJN3_ONLY__
- #warning TODO -- generate the full list
- #endif
- alias[0] = alias0;
- alias[1] = NULL;
- /* maybe it is already an address? */
- {
- struct in_addr *in = (struct in_addr *)(buf + sizeof(addr_list[0]) * 2);
- if (inet_aton(name, in)) {
- addr_list[0] = in;
- addr_list[1] = NULL;
- result_buf->h_name = alias0;
- result_buf->h_aliases = alias;
- result_buf->h_addrtype = AF_INET;
- result_buf->h_length = sizeof(struct in_addr);
- result_buf->h_addr_list = (char **) addr_list;
- *result = result_buf;
- *h_errnop = NETDB_SUCCESS;
- return NETDB_SUCCESS;
- }
- }
- /* what if /etc/hosts has it but it's not IPv4?
- * F.e. "::1 localhost6". We don't do DNS query for such hosts -
- * "ping localhost6" should be fast even if DNS server is down! */
- if (wrong_af) {
- *h_errnop = HOST_NOT_FOUND;
- return TRY_AGAIN;
- }
- /* talk to DNS servers */
- {
- a.buf = buf;
- /* take into account that at least one address will be there,
- * we'll need space of one in_addr + two addr_list[] elems */
- a.buflen = buflen - ((sizeof(addr_list[0]) * 2 + sizeof(struct in_addr)));
- a.add_count = 0;
- i = __dns_lookup(name, T_A, &packet, &a);
- if (i < 0) {
- *h_errnop = HOST_NOT_FOUND;
- DPRINTF("__dns_lookup returned < 0\n");
- return TRY_AGAIN;
- }
- }
- if (a.atype == T_A) { /* ADDRESS */
- /* we need space for addr_list[] and one IPv4 address */
- /* + 1 accounting for 1st addr (it's in a.rdata),
- * another + 1 for NULL in last addr_list[]: */
- int need_bytes = sizeof(addr_list[0]) * (a.add_count + 1 + 1)
- /* for 1st addr (it's in a.rdata): */
- + sizeof(struct in_addr);
- /* how many bytes will 2nd and following addresses take? */
- int ips_len = a.add_count * a.rdlength;
- buflen -= (need_bytes + ips_len);
- if ((ssize_t)buflen < 0) {
- DPRINTF("buffer too small for all addresses\n");
- /* *h_errnop = NETDB_INTERNAL; - already is */
- i = ERANGE;
- goto free_and_ret;
- }
- /* if there are additional addresses in buf,
- * move them forward so that they are not destroyed */
- DPRINTF("a.add_count:%d a.rdlength:%d a.rdata:%p\n", a.add_count, a.rdlength, a.rdata);
- memmove(buf + need_bytes, buf, ips_len);
- /* 1st address is in a.rdata, insert it */
- buf += need_bytes - sizeof(struct in_addr);
- memcpy(buf, a.rdata, sizeof(struct in_addr));
- /* fill addr_list[] */
- for (i = 0; i <= a.add_count; i++) {
- addr_list[i] = (struct in_addr*)buf;
- buf += sizeof(struct in_addr);
- }
- addr_list[i] = NULL;
- /* if we have enough space, we can report "better" name
- * (it may contain search domains attached by __dns_lookup,
- * or CNAME of the host if it is different from the name
- * we used to find it) */
- if (a.dotted && buflen > strlen(a.dotted)) {
- strcpy(buf, a.dotted);
- alias0 = buf;
- }
- result_buf->h_name = alias0;
- result_buf->h_aliases = alias;
- result_buf->h_addrtype = AF_INET;
- result_buf->h_length = sizeof(struct in_addr);
- result_buf->h_addr_list = (char **) addr_list;
- *result = result_buf;
- *h_errnop = NETDB_SUCCESS;
- i = NETDB_SUCCESS;
- goto free_and_ret;
- }
- *h_errnop = HOST_NOT_FOUND;
- i = TRY_AGAIN;
- free_and_ret:
- free(a.dotted);
- free(packet);
- return i;
- }
- libc_hidden_def(gethostbyname_r)
- #endif
- #ifdef L_gethostbyname2_r
- int gethostbyname2_r(const char *name,
- int family,
- struct hostent * result_buf,
- char * buf,
- size_t buflen,
- struct hostent ** result,
- int * h_errnop)
- {
- #ifndef __UCLIBC_HAS_IPV6__
- return family == (AF_INET)
- ? gethostbyname_r(name, result_buf, buf, buflen, result, h_errnop)
- : HOST_NOT_FOUND;
- #else
- struct in6_addr *in;
- struct in6_addr **addr_list;
- unsigned char *packet;
- struct resolv_answer a;
- int i;
- int nest = 0;
- int wrong_af = 0;
- if (family == AF_INET)
- return gethostbyname_r(name, result_buf, buf, buflen, result, h_errnop);
- *result = NULL;
- if (family != AF_INET6)
- return EINVAL;
- if (!name)
- return EINVAL;
- /* do /etc/hosts first */
- {
- int old_errno = errno; /* Save the old errno and reset errno */
- __set_errno(0); /* to check for missing /etc/hosts. */
- i = __get_hosts_byname_r(name, AF_INET6 /*family*/, result_buf,
- buf, buflen, result, h_errnop);
- if (i == NETDB_SUCCESS) {
- __set_errno(old_errno);
- return i;
- }
- switch (*h_errnop) {
- case HOST_NOT_FOUND:
- wrong_af = (i == TRY_AGAIN);
- case NO_ADDRESS:
- break;
- case NETDB_INTERNAL:
- if (errno == ENOENT) {
- break;
- }
- /* else fall through */
- default:
- return i;
- }
- __set_errno(old_errno);
- }
- DPRINTF("Nothing found in /etc/hosts\n");
- *h_errnop = NETDB_INTERNAL;
- /* make sure pointer is aligned */
- i = ALIGN_BUFFER_OFFSET(buf);
- buf += i;
- buflen -= i;
- in = (struct in6_addr*)buf;
- buf += sizeof(*in);
- buflen -= sizeof(*in);
- addr_list = (struct in6_addr**)buf;
- buf += sizeof(*addr_list) * 2;
- buflen -= sizeof(*addr_list) * 2;
- if ((ssize_t)buflen < 256)
- return ERANGE;
- addr_list[0] = in;
- addr_list[1] = NULL;
- strncpy(buf, name, buflen);
- /* maybe it is already an address? */
- if (inet_pton(AF_INET6, name, in)) {
- result_buf->h_name = buf;
- result_buf->h_addrtype = AF_INET6;
- result_buf->h_length = sizeof(*in);
- result_buf->h_addr_list = (char **) addr_list;
- *result = result_buf;
- *h_errnop = NETDB_SUCCESS;
- return NETDB_SUCCESS;
- }
- /* what if /etc/hosts has it but it's not IPv6?
- * F.e. "127.0.0.1 localhost". We don't do DNS query for such hosts -
- * "ping localhost" should be fast even if DNS server is down! */
- if (wrong_af) {
- *h_errnop = HOST_NOT_FOUND;
- return TRY_AGAIN;
- }
- /* talk to DNS servers */
- // TODO: why it's so different from gethostbyname_r (IPv4 case)?
- memset(&a, '\0', sizeof(a));
- for (;;) {
- i = __dns_lookup(buf, T_AAAA, &packet, &a);
- if (i < 0) {
- *h_errnop = HOST_NOT_FOUND;
- return TRY_AGAIN;
- }
- strncpy(buf, a.dotted, buflen);
- free(a.dotted);
- if (a.atype == T_CNAME) { /* CNAME */
- DPRINTF("Got a CNAME in gethostbyname()\n");
- i = __decode_dotted(packet, a.rdoffset, buf, buflen);
- free(packet);
- if (i < 0) {
- *h_errnop = NO_RECOVERY;
- return -1;
- }
- if (++nest > MAX_RECURSE) {
- *h_errnop = NO_RECOVERY;
- return -1;
- }
- continue;
- }
- if (a.atype == T_AAAA) { /* ADDRESS */
- memcpy(in, a.rdata, sizeof(*in));
- result_buf->h_name = buf;
- result_buf->h_addrtype = AF_INET6;
- result_buf->h_length = sizeof(*in);
- result_buf->h_addr_list = (char **) addr_list;
- free(packet);
- break;
- }
- free(packet);
- *h_errnop = HOST_NOT_FOUND;
- return TRY_AGAIN;
- }
- *result = result_buf;
- *h_errnop = NETDB_SUCCESS;
- return NETDB_SUCCESS;
- #endif /* __UCLIBC_HAS_IPV6__ */
- }
- libc_hidden_def(gethostbyname2_r)
- #endif
- #ifdef L_gethostbyaddr_r
- int gethostbyaddr_r(const void *addr, socklen_t len, int type,
- struct hostent * result_buf,
- char * buf, size_t buflen,
- struct hostent ** result,
- int * h_errnop)
- {
- struct in_addr *in;
- struct in_addr **addr_list;
- #ifdef __UCLIBC_HAS_IPV6__
- char *qp;
- size_t plen;
- struct in6_addr *in6;
- struct in6_addr **addr_list6;
- #endif /* __UCLIBC_HAS_IPV6__ */
- char **alias;
- unsigned char *packet;
- struct resolv_answer a;
- int i;
- int nest = 0;
- *result = NULL;
- if (!addr)
- return EINVAL;
- memset(&a, '\0', sizeof(a));
- switch (type) {
- case AF_INET:
- if (len != sizeof(struct in_addr))
- return EINVAL;
- break;
- #ifdef __UCLIBC_HAS_IPV6__
- case AF_INET6:
- if (len != sizeof(struct in6_addr))
- return EINVAL;
- break;
- #endif /* __UCLIBC_HAS_IPV6__ */
- default:
- return EINVAL;
- }
- /* do /etc/hosts first */
- i = __get_hosts_byaddr_r(addr, len, type, result_buf,
- buf, buflen, result, h_errnop);
- if (i == 0)
- return i;
- switch (*h_errnop) {
- case HOST_NOT_FOUND:
- case NO_ADDRESS:
- break;
- default:
- return i;
- }
- *h_errnop = NETDB_INTERNAL;
- /* make sure pointer is aligned */
- i = ALIGN_BUFFER_OFFSET(buf);
- buf += i;
- buflen -= i;
- #ifdef __UCLIBC_HAS_IPV6__
- qp = buf;
- plen = buflen;
- #endif
- in = (struct in_addr*)buf;
- buf += sizeof(*in);
- buflen -= sizeof(*in);
- addr_list = (struct in_addr**)buf;
- buf += sizeof(*addr_list) * 2;
- buflen -= sizeof(*addr_list) * 2;
- alias = (char **)buf;
- buf += sizeof(*alias) * ALIAS_DIM;
- buflen -= sizeof(*alias) * ALIAS_DIM;
- if ((ssize_t)buflen < 0)
- return ERANGE;
- #ifdef __UCLIBC_HAS_IPV6__
- in6 = (struct in6_addr*)qp;
- qp += sizeof(*in6);
- plen -= sizeof(*in6);
- addr_list6 = (struct in6_addr**)qp;
- qp += sizeof(*addr_list6) * 2;
- plen -= sizeof(*addr_list6) * 2;
- if ((ssize_t)plen < 0)
- return ERANGE;
- if (plen < buflen) {
- buflen = plen;
- buf = qp;
- }
- #endif
- if (buflen < 256)
- return ERANGE;
- if (type == AF_INET) {
- unsigned char *tmp_addr = (unsigned char *)addr;
- memcpy(&in->s_addr, addr, len);
- addr_list[0] = in;
- sprintf(buf, "%u.%u.%u.%u.in-addr.arpa",
- tmp_addr[3], tmp_addr[2], tmp_addr[1], tmp_addr[0]);
- }
- #ifdef __UCLIBC_HAS_IPV6__
- else {
- memcpy(in6->s6_addr, addr, len);
- addr_list6[0] = in6;
- qp = buf;
- for (i = len - 1; i >= 0; i--) {
- qp += sprintf(qp, "%x.%x.",
- in6->s6_addr[i] & 0xf,
- (in6->s6_addr[i] >> 4) & 0xf);
- }
- strcpy(qp, "ip6.arpa");
- }
- #endif
- addr_list[1] = NULL;
- alias[0] = buf;
- alias[1] = NULL;
- for (;;) {
- i = __dns_lookup(buf, T_PTR, &packet, &a);
- if (i < 0) {
- *h_errnop = HOST_NOT_FOUND;
- return TRY_AGAIN;
- }
- strncpy(buf, a.dotted, buflen);
- free(a.dotted);
- if (a.atype == T_CNAME) { /* CNAME */
- DPRINTF("Got a CNAME in gethostbyaddr()\n");
- i = __decode_dotted(packet, a.rdoffset, buf, buflen);
- free(packet);
- if (i < 0) {
- *h_errnop = NO_RECOVERY;
- return -1;
- }
- if (++nest > MAX_RECURSE) {
- *h_errnop = NO_RECOVERY;
- return -1;
- }
- continue;
- }
- if (a.atype == T_PTR) { /* ADDRESS */
- i = __decode_dotted(packet, a.rdoffset, buf, buflen);
- free(packet);
- result_buf->h_name = buf;
- result_buf->h_addrtype = type;
- if (type == AF_INET)
- result_buf->h_length = sizeof(*in);
- #ifdef __UCLIBC_HAS_IPV6__
- else
- result_buf->h_length = sizeof(*in6);
- #endif
- result_buf->h_addr_list = (char **) addr_list;
- result_buf->h_aliases = alias;
- break;
- }
- free(packet);
- *h_errnop = NO_ADDRESS;
- return TRY_AGAIN;
- }
- *result = result_buf;
- *h_errnop = NETDB_SUCCESS;
- return NETDB_SUCCESS;
- }
- libc_hidden_def(gethostbyaddr_r)
- #endif
- #ifdef L_gethostent_r
- __UCLIBC_MUTEX_STATIC(mylock, PTHREAD_MUTEX_INITIALIZER);
- static smallint __stay_open;
- static FILE * __gethostent_fp;
- void endhostent(void)
- {
- __UCLIBC_MUTEX_LOCK(mylock);
- __stay_open = 0;
- if (__gethostent_fp) {
- fclose(__gethostent_fp);
- __gethostent_fp = NULL;
- }
- __UCLIBC_MUTEX_UNLOCK(mylock);
- }
- void sethostent(int stay_open)
- {
- __UCLIBC_MUTEX_LOCK(mylock);
- __stay_open = (stay_open != 0);
- __UCLIBC_MUTEX_UNLOCK(mylock);
- }
- int gethostent_r(struct hostent *result_buf, char *buf, size_t buflen,
- struct hostent **result, int *h_errnop)
- {
- int ret;
- __UCLIBC_MUTEX_LOCK(mylock);
- if (__gethostent_fp == NULL) {
- __gethostent_fp = __open_etc_hosts();
- if (__gethostent_fp == NULL) {
- *result = NULL;
- ret = TRY_AGAIN;
- goto DONE;
- }
- }
- ret = __read_etc_hosts_r(__gethostent_fp, NULL, AF_INET, GETHOSTENT,
- result_buf, buf, buflen, result, h_errnop);
- if (__stay_open == 0) {
- fclose(__gethostent_fp);
- __gethostent_fp = NULL;
- }
- DONE:
- __UCLIBC_MUTEX_UNLOCK(mylock);
- return ret;
- }
- libc_hidden_def(gethostent_r)
- #endif
- #ifdef L_gethostent
- struct hostent *gethostent(void)
- {
- static struct hostent h;
- static char buf[
- #ifndef __UCLIBC_HAS_IPV6__
- sizeof(struct in_addr) + sizeof(struct in_addr *) * 2 +
- #else
- sizeof(struct in6_addr) + sizeof(struct in6_addr *) * 2 +
- #endif /* __UCLIBC_HAS_IPV6__ */
- sizeof(char *) * ALIAS_DIM +
- 80 /*namebuffer*/ + 2 /* margin */];
- struct hostent *host;
- gethostent_r(&h, buf, sizeof(buf), &host, &h_errno);
- return host;
- }
- #endif
- #ifdef L_gethostbyname2
- struct hostent *gethostbyname2(const char *name, int family)
- {
- #ifndef __UCLIBC_HAS_IPV6__
- return family == AF_INET ? gethostbyname(name) : (struct hostent*)NULL;
- #else
- static struct hostent h;
- static char buf[sizeof(struct in6_addr) +
- sizeof(struct in6_addr *) * 2 +
- sizeof(char *)*ALIAS_DIM + 384/*namebuffer*/ + 32/* margin */];
- struct hostent *hp;
- gethostbyname2_r(name, family, &h, buf, sizeof(buf), &hp, &h_errno);
- return hp;
- #endif
- }
- libc_hidden_def(gethostbyname2)
- #endif
- #ifdef L_gethostbyname
- struct hostent *gethostbyname(const char *name)
- {
- #ifndef __UCLIBC_HAS_IPV6__
- static struct hostent h;
- static char buf[sizeof(struct in_addr) +
- sizeof(struct in_addr *) * 2 +
- sizeof(char *)*ALIAS_DIM + 384/*namebuffer*/ + 32/* margin */];
- struct hostent *hp;
- gethostbyname_r(name, &h, buf, sizeof(buf), &hp, &h_errno);
- return hp;
- #else
- return gethostbyname2(name, AF_INET);
- #endif
- }
- libc_hidden_def(gethostbyname)
- #endif
- #ifdef L_gethostbyaddr
- struct hostent *gethostbyaddr(const void *addr, socklen_t len, int type)
- {
- static struct hostent h;
- static char buf[
- #ifndef __UCLIBC_HAS_IPV6__
- sizeof(struct in_addr) + sizeof(struct in_addr *)*2 +
- #else
- sizeof(struct in6_addr) + sizeof(struct in6_addr *)*2 +
- #endif /* __UCLIBC_HAS_IPV6__ */
- sizeof(char *)*ALIAS_DIM + 384 /*namebuffer*/ + 32 /* margin */];
- struct hostent *hp;
- gethostbyaddr_r(addr, len, type, &h, buf, sizeof(buf), &hp, &h_errno);
- return hp;
- }
- libc_hidden_def(gethostbyaddr)
- #endif
- #ifdef L_res_comp
- /*
- * Expand compressed domain name 'comp_dn' to full domain name.
- * 'msg' is a pointer to the begining of the message,
- * 'eomorig' points to the first location after the message,
- * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
- * Return size of compressed name or -1 if there was an error.
- */
- int __dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
- char *dst, int dstsiz)
- {
- int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
- if (n > 0 && dst[0] == '.')
- dst[0] = '\0';
- return n;
- }
- #endif /* L_res_comp */
- #ifdef L_ns_name
- /* Thinking in noninternationalized USASCII (per the DNS spec),
- * is this character visible and not a space when printed ?
- */
- static int printable(int ch)
- {
- return (ch > 0x20 && ch < 0x7f);
- }
- /* Thinking in noninternationalized USASCII (per the DNS spec),
- * is this characted special ("in need of quoting") ?
- */
- static int special(int ch)
- {
- switch (ch) {
- case 0x22: /* '"' */
- case 0x2E: /* '.' */
- case 0x3B: /* ';' */
- case 0x5C: /* '\\' */
- /* Special modifiers in zone files. */
- case 0x40: /* '@' */
- case 0x24: /* '$' */
- return 1;
- default:
- return 0;
- }
- }
- /*
- * ns_name_uncompress(msg, eom, src, dst, dstsiz)
- * Expand compressed domain name to presentation format.
- * return:
- * Number of bytes read out of `src', or -1 (with errno set).
- * note:
- * Root domain returns as "." not "".
- */
- int ns_name_uncompress(const u_char *msg, const u_char *eom,
- const u_char *src, char *dst, size_t dstsiz)
- {
- u_char tmp[NS_MAXCDNAME];
- int n;
- n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp);
- if (n == -1)
- return -1;
- if (ns_name_ntop(tmp, dst, dstsiz) == -1)
- return -1;
- return n;
- }
- libc_hidden_def(ns_name_uncompress)
- /*
- * ns_name_ntop(src, dst, dstsiz)
- * Convert an encoded domain name to printable ascii as per RFC1035.
- * return:
- * Number of bytes written to buffer, or -1 (with errno set)
- * notes:
- * The root is returned as "."
- * All other domains are returned in non absolute form
- */
- int ns_name_ntop(const u_char *src, char *dst, size_t dstsiz)
- {
- static const char digits[] = "0123456789";
- const u_char *cp;
- char *dn, *eom;
- u_char c;
- u_int n;
- cp = src;
- dn = dst;
- eom = dst + dstsiz;
- while ((n = *cp++) != 0) {
- if ((n & NS_CMPRSFLGS) != 0) {
- /* Some kind of compression pointer. */
- __set_errno(EMSGSIZE);
- return -1;
- }
- if (dn != dst) {
- if (dn >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- *dn++ = '.';
- }
- if (dn + n >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- for ((void)NULL; n > 0; n--) {
- c = *cp++;
- if (special(c)) {
- if (dn + 1 >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- *dn++ = '\\';
- *dn++ = (char)c;
- } else if (!printable(c)) {
- if (dn + 3 >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- *dn++ = '\\';
- *dn++ = digits[c / 100];
- *dn++ = digits[(c % 100) / 10];
- *dn++ = digits[c % 10];
- } else {
- if (dn >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- *dn++ = (char)c;
- }
- }
- }
- if (dn == dst) {
- if (dn >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- *dn++ = '.';
- }
- if (dn >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- *dn++ = '\0';
- return (dn - dst);
- }
- libc_hidden_def(ns_name_ntop)
- /*
- * ns_name_unpack(msg, eom, src, dst, dstsiz)
- * Unpack a domain name from a message, source may be compressed.
- * return:
- * -1 if it fails, or consumed octets if it succeeds.
- */
- int ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
- u_char *dst, size_t dstsiz)
- {
- const u_char *srcp, *dstlim;
- u_char *dstp;
- int n, len, checked;
- len = -1;
- checked = 0;
- dstp = dst;
- srcp = src;
- dstlim = dst + dstsiz;
- if (srcp < msg || srcp >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- /* Fetch next label in domain name. */
- while ((n = *srcp++) != 0) {
- /* Check for indirection. */
- switch (n & NS_CMPRSFLGS) {
- case 0:
- /* Limit checks. */
- if (dstp + n + 1 >= dstlim || srcp + n >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- checked += n + 1;
- *dstp++ = n;
- memcpy(dstp, srcp, n);
- dstp += n;
- srcp += n;
- break;
- case NS_CMPRSFLGS:
- if (srcp >= eom) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- if (len < 0)
- len = srcp - src + 1;
- srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
- if (srcp < msg || srcp >= eom) { /* Out of range. */
- __set_errno(EMSGSIZE);
- return -1;
- }
- checked += 2;
- /*
- * Check for loops in the compressed name;
- * if we've looked at the whole message,
- * there must be a loop.
- */
- if (checked >= eom - msg) {
- __set_errno(EMSGSIZE);
- return -1;
- }
- break;
- default:
- __set_errno(EMSGSIZE);
- return -1; /* flag error */
- }
- }
- *dstp = '\0';
- if (len < 0)
- len = srcp - src;
- return len;
- }
- libc_hidden_def(ns_name_unpack)
- #endif /* L_ns_name */
- #ifdef L_res_init
- /* Protected by __resolv_lock */
- struct __res_state _res;
- /* Will be called under __resolv_lock. */
- static void res_sync_func(void)
- {
- struct __res_state *rp = &(_res);
- int n;
- /* If we didn't get malloc failure earlier... */
- if (__nameserver != (void*) &__local_nameserver) {
- /* TODO:
- * if (__nameservers < rp->nscount) - try to grow __nameserver[]?
- */
- #ifdef __UCLIBC_HAS_IPV6__
- if (__nameservers > rp->_u._ext.nscount)
- __nameservers = rp->_u._ext.nscount;
- n = __nameservers;
- while (--n >= 0)
- __nameserver[n].sa6 = *rp->_u._ext.nsaddrs[n]; /* struct copy */
- #else /* IPv4 only */
- if (__nameservers > rp->nscount)
- __nameservers = rp->nscount;
- n = __nameservers;
- while (--n >= 0)
- __nameserver[n].sa4 = rp->nsaddr_list[n]; /* struct copy */
- #endif
- }
- /* Extend and comment what program is known
- * to use which _res.XXX member(s).
- */
- // __resolv_opts = rp->options;
- // ...
- }
- /* Our res_init never fails (always returns 0) */
- int res_init(void)
- {
- struct __res_state *rp = &(_res);
- int i;
- int n;
- #ifdef __UCLIBC_HAS_IPV6__
- int m = 0;
- #endif
- __UCLIBC_MUTEX_LOCK(__resolv_lock);
- __close_nameservers();
- __open_nameservers();
- __res_sync = res_sync_func;
- memset(rp, 0, sizeof(*rp));
- rp->options = RES_INIT;
- #ifdef __UCLIBC_HAS_COMPAT_RES_STATE__
- rp->retrans = RES_TIMEOUT;
- rp->retry = 4;
- //TODO: pulls in largish static buffers... use simpler one?
- rp->id = random();
- #endif
- rp->ndots = 1;
- #ifdef __UCLIBC_HAS_EXTRA_COMPAT_RES_STATE__
- rp->_vcsock = -1;
- #endif
- n = __searchdomains;
- if (n > ARRAY_SIZE(rp->dnsrch))
- n = ARRAY_SIZE(rp->dnsrch);
- for (i = 0; i < n; i++)
- rp->dnsrch[i] = __searchdomain[i];
- /* copy nameservers' addresses */
- i = 0;
- #ifdef __UCLIBC_HAS_IPV4__
- n = 0;
- while (n < ARRAY_SIZE(rp->nsaddr_list) && i < __nameservers) {
- if (__nameserver[i].sa.sa_family == AF_INET) {
- rp->nsaddr_list[n] = __nameserver[i].sa4; /* struct copy */
- #ifdef __UCLIBC_HAS_IPV6__
- if (m < ARRAY_SIZE(rp->_u._ext.nsaddrs)) {
- rp->_u._ext.nsaddrs[m] = (void*) &rp->nsaddr_list[n];
- m++;
- }
- #endif
- n++;
- }
- #ifdef __UCLIBC_HAS_IPV6__
- if (__nameserver[i].sa.sa_family == AF_INET6
- && m < ARRAY_SIZE(rp->_u._ext.nsaddrs)
- ) {
- struct sockaddr_in6 *sa6 = malloc(sizeof(sa6));
- if (sa6) {
- *sa6 = __nameserver[i].sa6; /* struct copy */
- rp->_u._ext.nsaddrs[m] = sa6;
- m++;
- }
- }
- #endif
- i++;
- }
- rp->nscount = n;
- #ifdef __UCLIBC_HAS_IPV6__
- rp->_u._ext.nscount = m;
- #endif
- #else /* IPv6 only */
- while (m < ARRAY_SIZE(rp->_u._ext.nsaddrs) && i < __nameservers) {
- struct sockaddr_in6 *sa6 = malloc(sizeof(sa6));
- if (sa6) {
- *sa6 = __nameserver[i].sa6; /* struct copy */
- rp->_u._ext.nsaddrs[m] = sa6;
- m++;
- }
- i++;
- }
- rp->_u._ext.nscount = m;
- #endif
- __UCLIBC_MUTEX_UNLOCK(__resolv_lock);
- return 0;
- }
- libc_hidden_def(res_init)
- #ifdef __UCLIBC_HAS_BSD_RES_CLOSE__
- void res_close(void)
- {
- __UCLIBC_MUTEX_LOCK(__resolv_lock);
- __close_nameservers();
- __res_sync = NULL;
- #ifdef __UCLIBC_HAS_IPV6__
- {
- char *p1 = (char*) &(_res.nsaddr_list[0]);
- int m = 0;
- /* free nsaddrs[m] if they do not point to nsaddr_list[x] */
- while (m < ARRAY_SIZE(_res._u._ext.nsaddrs)) {
- char *p2 = (char*)(_res._u._ext.nsaddrs[m]);
- if (p2 < p1 || (p2 - p1) > sizeof(_res.nsaddr_list))
- free(p2);
- }
- }
- #endif
- memset(&_res, 0, sizeof(_res));
- __UCLIBC_MUTEX_UNLOCK(__resolv_lock);
- }
- #endif
- #endif /* L_res_init */
- #ifdef L_res_query
- int res_query(const char *dname, int class, int type,
- unsigned char *answer, int anslen)
- {
- int i;
- unsigned char * packet = NULL;
- struct resolv_answer a;
- if (!dname || class != 1 /* CLASS_IN */) {
- h_errno = NO_RECOVERY;
- return -1;
- }
- memset(&a, '\0', sizeof(a));
- i = __dns_lookup(dname, type, &packet, &a);
- if (i < 0) {
- h_errno = TRY_AGAIN;
- return -1;
- }
- free(a.dotted);
- if (a.atype == type) { /* CNAME */
- if (i > anslen)
- i = anslen;
- memcpy(answer, packet, i);
- }
- free(packet);
- return i;
- }
- libc_hidden_def(res_query)
- /*
- * Formulate a normal query, send, and retrieve answer in supplied buffer.
- * Return the size of the response on success, -1 on error.
- * If enabled, implement search rules until answer or unrecoverable failure
- * is detected. Error code, if any, is left in h_errno.
- */
- #define __TRAILING_DOT (1<<0)
- #define __GOT_NODATA (1<<1)
- #define __GOT_SERVFAIL (1<<2)
- #define __TRIED_AS_IS (1<<3)
- int res_search(const char *name, int class, int type, u_char *answer,
- int anslen)
- {
- const char *cp, * const *domain;
- HEADER *hp = (HEADER *)(void *)answer;
- unsigned dots;
- unsigned state;
- int ret, saved_herrno;
- uint32_t _res_options;
- unsigned _res_ndots;
- char **_res_dnsrch;
- if (!name || !answer) {
- h_errno = NETDB_INTERNAL;
- return -1;
- }
- again:
- __UCLIBC_MUTEX_LOCK(__resolv_lock);
- _res_options = _res.options;
- _res_ndots = _res.ndots;
- _res_dnsrch = _res.dnsrch;
- __UCLIBC_MUTEX_UNLOCK(__resolv_lock);
- if (!(_res_options & RES_INIT)) {
- res_init(); /* our res_init never fails */
- goto again;
- }
- state = 0;
- errno = 0;
- h_errno = HOST_NOT_FOUND; /* default, if we never query */
- dots = 0;
- for (cp = name; *cp; cp++)
- dots += (*cp == '.');
- if (cp > name && *--cp == '.')
- state |= __TRAILING_DOT;
- /*
- * If there are dots in the name already, let's just give it a try
- * 'as is'. The threshold can be set with the "ndots" option.
- */
- saved_herrno = -1;
- if (dots >= _res_ndots) {
- ret = res_querydomain(name, NULL, class, type, answer, anslen);
- if (ret > 0)
- return ret;
- saved_herrno = h_errno;
- state |= __TRIED_AS_IS;
- }
- /*
- * We do at least one level of search if
- * - there is no dot and RES_DEFNAME is set, or
- * - there is at least one dot, there is no trailing dot,
- * and RES_DNSRCH is set.
- */
- if ((!dots && (_res_options & RES_DEFNAMES))
- || (dots && !(state & __TRAILING_DOT) && (_res_options & RES_DNSRCH))
- ) {
- bool done = 0;
- for (domain = (const char * const *)_res_dnsrch;
- *domain && !done;
- domain++) {
- ret = res_querydomain(name, *domain, class, type,
- answer, anslen);
- if (ret > 0)
- return ret;
- /*
- * If no server present, give up.
- * If name isn't found in this domain,
- * keep trying higher domains in the search list
- * (if that's enabled).
- * On a NO_DATA error, keep trying, otherwise
- * a wildcard entry of another type could keep us
- * from finding this entry higher in the domain.
- * If we get some other error (negative answer or
- * server failure), then stop searching up,
- * but try the input name below in case it's
- * fully-qualified.
- */
- if (errno == ECONNREFUSED) {
- h_errno = TRY_AGAIN;
- return -1;
- }
- switch (h_errno) {
- case NO_DATA:
- state |= __GOT_NODATA;
- /* FALLTHROUGH */
- case HOST_NOT_FOUND:
- /* keep trying */
- break;
- case TRY_AGAIN:
- if (hp->rcode == SERVFAIL) {
- /* try next search element, if any */
- state |= __GOT_SERVFAIL;
- break;
- }
- /* FALLTHROUGH */
- default:
- /* anything else implies that we're done */
- done = 1;
- }
- /*
- * if we got here for some reason other than DNSRCH,
- * we only wanted one iteration of the loop, so stop.
- */
- if (!(_res_options & RES_DNSRCH))
- done = 1;
- }
- }
- /*
- * if we have not already tried the name "as is", do that now.
- * note that we do this regardless of how many dots were in the
- * name or whether it ends with a dot.
- */
- if (!(state & __TRIED_AS_IS)) {
- ret = res_querydomain(name, NULL, class, type, answer, anslen);
- if (ret > 0)
- return ret;
- }
- /*
- * if we got here, we didn't satisfy the search.
- * if we did an initial full query, return that query's h_errno
- * (note that we wouldn't be here if that query had succeeded).
- * else if we ever got a nodata, send that back as the reason.
- * else send back meaningless h_errno, that being the one from
- * the last DNSRCH we did.
- */
- if (saved_herrno != -1)
- h_errno = saved_herrno;
- else if (state & __GOT_NODATA)
- h_errno = NO_DATA;
- else if (state & __GOT_SERVFAIL)
- h_errno = TRY_AGAIN;
- return -1;
- }
- #undef __TRAILING_DOT
- #undef __GOT_NODATA
- #undef __GOT_SERVFAIL
- #undef __TRIED_AS_IS
- /*
- * Perform a call on res_query on the concatenation of name and domain,
- * removing a trailing dot from name if domain is NULL.
- */
- int res_querydomain(const char *name, const char *domain, int class, int type,
- u_char * answer, int anslen)
- {
- char nbuf[MAXDNAME];
- const char *longname = nbuf;
- size_t n, d;
- #ifdef DEBUG
- uint32_t _res_options;
- #endif
- if (!name || !answer) {
- h_errno = NETDB_INTERNAL;
- return -1;
- }
- #ifdef DEBUG
- again:
- __UCLIBC_MUTEX_LOCK(__resolv_lock);
- _res_options = _res.options;
- __UCLIBC_MUTEX_UNLOCK(__resolv_lock);
- if (!(_res_options & RES_INIT)) {
- res_init(); /* our res_init never fails */
- goto again:
- }
- if (_res_options & RES_DEBUG)
- printf(";; res_querydomain(%s, %s, %d, %d)\n",
- name, (domain ? domain : "<Nil>"), class, type);
- #endif
- if (domain == NULL) {
- /*
- * Check for trailing '.';
- * copy without '.' if present.
- */
- n = strlen(name);
- if (n + 1 > sizeof(nbuf)) {
- h_errno = NO_RECOVERY;
- return -1;
- }
- if (n > 0 && name[--n] == '.') {
- strncpy(nbuf, name, n);
- nbuf[n] = '\0';
- } else
- longname = name;
- } else {
- n = strlen(name);
- d = strlen(domain);
- if (n + 1 + d + 1 > sizeof(nbuf)) {
- h_errno = NO_RECOVERY;
- return -1;
- }
- snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
- }
- return res_query(longname, class, type, answer, anslen);
- }
- libc_hidden_def(res_querydomain)
- /* res_mkquery */
- /* res_send */
- /* dn_comp */
- /* dn_expand */
- #endif
- /* vi: set sw=4 ts=4: */
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