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-rw-r--r--lib/libc/resolv/res_query.c432
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diff --git a/lib/libc/resolv/res_query.c b/lib/libc/resolv/res_query.c
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+/*
+ * 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.
+ */
+
+/*
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * 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 ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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 const char sccsid[] = "@(#)res_query.c 8.1 (Berkeley) 6/4/93";
+static const char rcsid[] = "$Id: res_query.c,v 1.2.2.3.4.2 2004/03/16 12:34:19 marka Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include "port_before.h"
+#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 "port_after.h"
+
+/* Options. Leave them on. */
+#define DEBUG
+
+#if PACKETSZ > 1024
+#define MAXPACKET PACKETSZ
+#else
+#define MAXPACKET 1024
+#endif
+
+/*
+ * 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_nquery(res_state statp,
+ const char *name, /* domain name */
+ int class, int 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;
+ u_int oflags;
+
+ oflags = statp->_flags;
+
+again:
+ hp->rcode = NOERROR; /* default */
+
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG)
+ printf(";; res_query(%s, %d, %d)\n", name, class, type);
+#endif
+
+ n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL,
+ buf, sizeof(buf));
+#ifdef RES_USE_EDNS0
+ if (n > 0 && (statp->_flags & RES_F_EDNS0ERR) == 0 &&
+ (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U)
+ n = res_nopt(statp, n, buf, sizeof(buf), anslen);
+#endif
+ if (n <= 0) {
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG)
+ printf(";; res_query: mkquery failed\n");
+#endif
+ RES_SET_H_ERRNO(statp, NO_RECOVERY);
+ return (n);
+ }
+ n = res_nsend(statp, buf, n, answer, anslen);
+ if (n < 0) {
+#ifdef RES_USE_EDNS0
+ /* if the query choked with EDNS0, retry without EDNS0 */
+ if ((statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U &&
+ ((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) {
+ statp->_flags |= RES_F_EDNS0ERR;
+ if (statp->options & RES_DEBUG)
+ printf(";; res_nquery: retry without EDNS0\n");
+ goto again;
+ }
+#endif
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG)
+ printf(";; res_query: send error\n");
+#endif
+ RES_SET_H_ERRNO(statp, TRY_AGAIN);
+ return (n);
+ }
+
+ if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG)
+ printf(";; rcode = (%s), counts = an:%d ns:%d ar:%d\n",
+ p_rcode(hp->rcode),
+ ntohs(hp->ancount),
+ ntohs(hp->nscount),
+ ntohs(hp->arcount));
+#endif
+ switch (hp->rcode) {
+ case NXDOMAIN:
+ RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
+ break;
+ case SERVFAIL:
+ RES_SET_H_ERRNO(statp, TRY_AGAIN);
+ break;
+ case NOERROR:
+ RES_SET_H_ERRNO(statp, NO_DATA);
+ break;
+ case FORMERR:
+ case NOTIMP:
+ case REFUSED:
+ default:
+ RES_SET_H_ERRNO(statp, 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_nsearch(res_state statp,
+ const char *name, /* domain name */
+ int class, int type, /* class and type of query */
+ u_char *answer, /* buffer to put answer */
+ int anslen) /* size of answer */
+{
+ const char *cp, * const *domain;
+ HEADER *hp = (HEADER *) answer;
+ char tmp[NS_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;
+
+ errno = 0;
+ RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); /* True if we never query. */
+
+ dots = 0;
+ for (cp = name; *cp != '\0'; 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(statp, name, tmp, sizeof tmp))!= NULL)
+ return (res_nquery(statp, 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 >= statp->ndots || trailing_dot) {
+ ret = res_nquerydomain(statp, name, NULL, class, type,
+ answer, anslen);
+ if (ret > 0 || trailing_dot)
+ return (ret);
+ saved_herrno = statp->res_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 && (statp->options & RES_DEFNAMES) != 0U) ||
+ (dots && !trailing_dot && (statp->options & RES_DNSRCH) != 0U)) {
+ int done = 0;
+
+ for (domain = (const char * const *)statp->dnsrch;
+ *domain && !done;
+ domain++) {
+ searched = 1;
+
+ if (domain[0][0] == '\0' ||
+ (domain[0][0] == '.' && domain[0][1] == '\0'))
+ root_on_list++;
+
+ ret = res_nquerydomain(statp, 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) {
+ RES_SET_H_ERRNO(statp, TRY_AGAIN);
+ return (-1);
+ }
+
+ switch (statp->res_h_errno) {
+ case NO_DATA:
+ got_nodata++;
+ /* FALLTHROUGH */
+ case HOST_NOT_FOUND:
+ /* keep trying */
+ break;
+ case TRY_AGAIN:
+ if (hp->rcode == SERVFAIL) {
+ /* try next search element, if any */
+ got_servfail++;
+ break;
+ }
+ /* 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 ((statp->options & RES_DNSRCH) == 0U)
+ done++;
+ }
+ }
+
+ /*
+ * 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 || (statp->options & RES_NOTLDQUERY) == 0U) &&
+ !(tried_as_is || root_on_list)) {
+ ret = res_nquerydomain(statp, 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)
+ RES_SET_H_ERRNO(statp, saved_herrno);
+ else if (got_nodata)
+ RES_SET_H_ERRNO(statp, NO_DATA);
+ else if (got_servfail)
+ RES_SET_H_ERRNO(statp, 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_nquerydomain(res_state statp,
+ const char *name,
+ const char *domain,
+ int class, int 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;
+
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG)
+ printf(";; res_nquerydomain(%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) {
+ RES_SET_H_ERRNO(statp, 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) {
+ RES_SET_H_ERRNO(statp, NO_RECOVERY);
+ return (-1);
+ }
+ sprintf(nbuf, "%s.%s", name, domain);
+ }
+ return (res_nquery(statp, longname, class, type, answer, anslen));
+}
+
+const char *
+res_hostalias(const res_state statp, const char *name, char *dst, size_t siz) {
+ char *file, *cp1, *cp2;
+ char buf[BUFSIZ];
+ FILE *fp;
+
+ if (statp->options & RES_NOALIASES)
+ 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 (ns_samename(buf, name) == 1) {
+ 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);
+}
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