diff options
Diffstat (limited to 'lib/libc/net/res_query.c')
| -rw-r--r-- | lib/libc/net/res_query.c | 478 |
1 files changed, 0 insertions, 478 deletions
diff --git a/lib/libc/net/res_query.c b/lib/libc/net/res_query.c deleted file mode 100644 index 0cfed03..0000000 --- a/lib/libc/net/res_query.c +++ /dev/null @@ -1,478 +0,0 @@ -/*- - * Copyright (c) 1988, 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. - */ - -/* - * 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 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. - */ - -#if defined(LIBC_SCCS) && !defined(lint) -static char sccsid[] = "@(#)res_query.c 8.1 (Berkeley) 6/4/93"; -static char rcsid[] = "$Id: res_query.c,v 8.14 1997/06/09 17:47:05 halley Exp $"; -#endif /* LIBC_SCCS and not lint */ -#include <sys/cdefs.h> -__FBSDID("$FreeBSD$"); - -#include <sys/types.h> -#include <sys/param.h> -#include <netinet/in.h> -#include <arpa/inet.h> -#include <arpa/nameser.h> -#include <ctype.h> -#include <errno.h> -#include <netdb.h> -#include <resolv.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> - -#include "res_config.h" - -#if PACKETSZ > 1024 -#define MAXPACKET PACKETSZ -#else -#define MAXPACKET 1024 -#endif - -const char *_res_hostalias(const char *, char *, size_t); - -/* - * Formulate a normal query, send, and await answer. - * Returned answer is placed in supplied buffer "answer". - * Perform preliminary check of answer, returning success only - * if no error is indicated and the answer count is nonzero. - * Return the size of the response on success, -1 on error. - * Error number is left in h_errno. - * - * Caller must parse answer and determine whether it answers the question. - */ -int -res_query(name, class, type, answer, anslen) - const char *name; /* domain name */ - int class, type; /* class and type of query */ - u_char *answer; /* buffer to put answer */ - int anslen; /* size of answer buffer */ -{ - u_char buf[MAXPACKET]; - HEADER *hp = (HEADER *) answer; - int n; - - hp->rcode = NOERROR; /* default */ - - if ((_res.options & RES_INIT) == 0 && res_init() == -1) { - h_errno = NETDB_INTERNAL; - return (-1); - } -#ifdef DEBUG - if (_res.options & RES_DEBUG) - printf(";; res_query(%s, %d, %d)\n", name, class, type); -#endif - - n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, - buf, sizeof(buf)); - if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) - n = res_opt(n, buf, sizeof(buf), anslen); - if (n <= 0) { -#ifdef DEBUG - if (_res.options & RES_DEBUG) - printf(";; res_query: mkquery failed\n"); -#endif - h_errno = NO_RECOVERY; - return (n); - } - n = res_send(buf, n, answer, anslen); - if (n < 0) { -#ifdef DEBUG - if (_res.options & RES_DEBUG) - printf(";; res_query: send error\n"); -#endif - h_errno = TRY_AGAIN; - return (n); - } - - if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { -#ifdef DEBUG - if (_res.options & RES_DEBUG) - printf(";; rcode = %d, ancount=%d\n", hp->rcode, - ntohs(hp->ancount)); -#endif - switch (hp->rcode) { - case NXDOMAIN: - h_errno = HOST_NOT_FOUND; - break; - case SERVFAIL: - h_errno = TRY_AGAIN; - break; - case NOERROR: - h_errno = NO_DATA; - break; - case FORMERR: - case NOTIMP: - case REFUSED: - default: - h_errno = NO_RECOVERY; - break; - } - return (-1); - } - return (n); -} - -/* - * 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. - */ -int -res_search(name, class, type, answer, anslen) - const char *name; /* domain name */ - int class, type; /* class and type of query */ - u_char *answer; /* buffer to put answer */ - int anslen; /* size of answer */ -{ - const char *cp, * const *domain; - char tmp[MAXDNAME]; - u_int dots; - int trailing_dot, ret, saved_herrno; - int got_nodata = 0, got_servfail = 0, root_on_list = 0; - int tried_as_is = 0; - int searched = 0; - - if ((_res.options & RES_INIT) == 0 && res_init() == -1) { - h_errno = NETDB_INTERNAL; - return (-1); - } - errno = 0; - h_errno = HOST_NOT_FOUND; /* default, if we never query */ - dots = 0; - for (cp = name; *cp; cp++) - dots += (*cp == '.'); - trailing_dot = 0; - if (cp > name && *--cp == '.') - trailing_dot++; - - /* If there aren't any dots, it could be a user-level alias */ - if (!dots && (cp = _res_hostalias(name, tmp, sizeof tmp)) != NULL) - return (res_query(cp, class, type, answer, anslen)); - - /* - * If there are enough dots in the name, let's just give it a - * try 'as is'. The threshold can be set with the "ndots" option. - * Also, query 'as is', if there is a trailing dot in the name. - */ - saved_herrno = -1; - if (dots >= _res.ndots || trailing_dot) { - ret = res_querydomain(name, NULL, class, type, answer, anslen); - if (ret > 0 || trailing_dot) - return (ret); - if (errno == ECONNREFUSED) { - h_errno = TRY_AGAIN; - return (-1); - } - switch (h_errno) { - case NO_DATA: - case HOST_NOT_FOUND: - break; - default: - return (-1); - } - saved_herrno = h_errno; - 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 && !trailing_dot && (_res.options & RES_DNSRCH))) { - int done = 0; - - for (domain = (const char * const *)_res.dnsrch; - *domain && !done; - domain++) { - searched = 1; - - if (domain[0][0] == '\0' || - (domain[0][0] == '.' && domain[0][1] == '\0')) - root_on_list++; - - if (root_on_list && tried_as_is) - continue; - - 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: - got_nodata++; - /* FALLTHROUGH */ - case HOST_NOT_FOUND: - /* keep trying */ - break; - case TRY_AGAIN: - /* - * This can occur due to a server failure - * (that is, all listed servers have failed), - * or all listed servers have timed out. - * ((HEADER *)answer)->rcode may not be set - * to SERVFAIL in the case of a timeout. - * - * Either way we must terminate the search - * and return TRY_AGAIN in order to avoid - * non-deterministic return codes. For - * example, loaded name servers or races - * against network startup/validation (dhcp, - * ppp, etc) can cause the search to timeout - * on one search element, e.g. 'fu.bar.com', - * and return a definitive failure on the - * next search element, e.g. 'fu.'. - */ - ++got_servfail; - /* FALLTHROUGH */ - default: - /* anything else implies that we're done */ - done++; - } - - /* 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++; - } - } - - switch (h_errno) { - case NO_DATA: - case HOST_NOT_FOUND: - break; - default: - goto giveup; - } - - /* - * If the query has not already been tried as is then try it - * unless RES_NOTLDQUERY is set and there were no dots. - */ - if ((dots || !searched || !(_res.options & RES_NOTLDQUERY)) && - !(tried_as_is || root_on_list)) { - 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. - */ -giveup: - if (saved_herrno != -1) - h_errno = saved_herrno; - else if (got_nodata) - h_errno = NO_DATA; - else if (got_servfail) - h_errno = TRY_AGAIN; - return (-1); -} - -/* - * 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(name, domain, class, type, answer, anslen) - const char *name, *domain; - int class, type; /* class and type of query */ - u_char *answer; /* buffer to put answer */ - int anslen; /* size of answer */ -{ - char nbuf[MAXDNAME]; - const char *longname = nbuf; - int n, d; - - if ((_res.options & RES_INIT) == 0 && res_init() == -1) { - h_errno = NETDB_INTERNAL; - return (-1); - } -#ifdef DEBUG - 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 >= MAXDNAME) { - h_errno = NO_RECOVERY; - return (-1); - } - n--; - if (n >= 0 && name[n] == '.') { - strncpy(nbuf, name, n); - nbuf[n] = '\0'; - } else - longname = name; - } else { - n = strlen(name); - d = strlen(domain); - if (n + d + 1 >= MAXDNAME) { - h_errno = NO_RECOVERY; - return (-1); - } - sprintf(nbuf, "%s.%s", name, domain); - } - return (res_query(longname, class, type, answer, anslen)); -} - -const char * -_res_hostalias(const char *name, char *dst, size_t siz) -{ - char *file, *cp1, *cp2; - char buf[BUFSIZ]; - FILE *fp; - - if (_res.options & RES_NOALIASES) - return (NULL); - if (issetugid()) - return (NULL); - file = getenv("HOSTALIASES"); - if (file == NULL || (fp = fopen(file, "r")) == NULL) - return (NULL); - setbuf(fp, NULL); - buf[sizeof(buf) - 1] = '\0'; - while (fgets(buf, sizeof(buf), fp)) { - for (cp1 = buf; *cp1 && !isspace((unsigned char)*cp1); ++cp1) - ; - if (!*cp1) - break; - *cp1 = '\0'; - if (!strcasecmp(buf, name)) { - while (isspace((unsigned char)*++cp1)) - ; - if (!*cp1) - break; - for (cp2 = cp1 + 1; *cp2 && - !isspace((unsigned char)*cp2); ++cp2) - ; - *cp2 = '\0'; - strncpy(dst, cp1, siz - 1); - dst[siz - 1] = '\0'; - fclose(fp); - return (dst); - } - } - fclose(fp); - return (NULL); -} - -const char * -hostalias(const char *name) -{ - static char abuf[MAXDNAME]; - - return (_res_hostalias(name, abuf, sizeof abuf)); -} - -/* - * Weak aliases for applications that use certain private entry points, - * and fail to include <resolv.h>. - */ -#undef res_query -__weak_reference(__res_query, res_query); -#undef res_search -__weak_reference(__res_search, res_search); -#undef res_querydomain -__weak_reference(__res_querydomain, res_querydomain); |
