1 files changed, 405 insertions, 0 deletions

diff --git a/src/lib/libc/net/res_query.c b/src/lib/libc/net/res_query.c
new file mode 100644
index 0000000000..9c1aef1218
--- /dev/null
+++ b/src/lib/libc/net/res_query.c
@@ -0,0 +1,405 @@
+/*      $OpenBSD: res_query.c,v 1.19 2002/06/27 09:55:49 itojun Exp $   */
+
+/*
+ * ++Copyright++ 1988, 1993
+ * -
+ * 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--
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)res_query.c 8.1 (Berkeley) 6/4/93";
+static char rcsid[] = "$From: res_query.c,v 8.9 1996/09/22 00:13:28 vixie Exp $";
+#else
+static char rcsid[] = "$OpenBSD: res_query.c,v 1.19 2002/06/27 09:55:49 itojun Exp $";
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+
+#include <stdio.h>
+#include <netdb.h>
+#include <resolv.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#if PACKETSZ > 1024
+#define MAXPACKET       PACKETSZ
+#else
+#define MAXPACKET       1024
+#endif
+
+const char *hostalias(const char *);
+int h_errno;
+extern int res_opt(int, u_char *, int, int);
+
+/*
+ * 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];
+        register 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) ||
+            (_res.options & RES_USE_DNSSEC))) {
+                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 = %u, ancount=%u\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 */
+{
+        register const char *cp, * const *domain;
+        HEADER *hp = (HEADER *) answer;
+        u_int dots;
+        int trailing_dot, ret, saved_herrno;
+        int got_nodata = 0, got_servfail = 0, tried_as_is = 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 = __hostalias(name)) != NULL)
+                return (res_query(cp, class, type, answer, anslen));
+
+        /*
+         * 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;
+                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++) {
+
+                        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:
+                                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 (!(_res.options & RES_DNSRCH))
+                                done++;
+                }
+        }
+
+        /* 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 (!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 (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*2+1+1];
+        const char *longname = nbuf;
+        int n;
+
+        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) - 1;
+                if (n != (0 - 1) && name[n] == '.' && n < sizeof(nbuf) - 1) {
+                        bcopy(name, nbuf, n);
+                        nbuf[n] = '\0';
+                } else
+                        longname = name;
+        } else
+                snprintf(nbuf, sizeof nbuf, "%.*s.%.*s",
+                    MAXDNAME, name, MAXDNAME, domain);
+
+        return (res_query(longname, class, type, answer, anslen));
+}
+
+const char *
+hostalias(name)
+        register const char *name;
+{
+        register char *cp1, *cp2;
+        FILE *fp;
+        char *file;
+        char buf[BUFSIZ];
+        static char abuf[MAXDNAME];
+        size_t len;
+
+        if (_res.options & RES_NOALIASES)
+                return (NULL);
+        file = getenv("HOSTALIASES");
+        if (issetugid() != 0 || file == NULL || (fp = fopen(file, "r")) == NULL)
+                return (NULL);
+        setbuf(fp, NULL);
+        while ((cp1 = fgetln(fp, &len)) != NULL) {
+                if (cp1[len-1] == '\n')
+                        len--;
+                if (len >= sizeof(buf) || len == 0)
+                        continue;
+                (void)memcpy(buf, cp1, len);
+                buf[len] = '\0';
+                
+                for (cp1 = buf; *cp1 && !isspace(*cp1); ++cp1)
+                        ;
+                if (!*cp1)
+                        break;
+                *cp1 = '\0';
+                if (!strcasecmp(buf, name)) {
+                        while (isspace(*++cp1))
+                                ;
+                        if (!*cp1)
+                                break;
+                        for (cp2 = cp1 + 1; *cp2 && !isspace(*cp2); ++cp2)
+                                ;
+                        *cp2 = '\0';
+                        strlcpy(abuf, cp1, sizeof(abuf));
+                        fclose(fp);
+                        return (abuf);
+                }
+        }
+        fclose(fp);
+        return (NULL);
+}