/*
* 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:
* 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
/*
* 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
static const char rcsid[] = "$BINDId: res_query.c,v 8.20 2000/02/29 05:39:12 vixie Exp $";
#endif /* LIBC_SCCS and not lint */
+#include <assert.h>
#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
/* Options. Leave them on. */
/* #undef DEBUG */
-#if PACKETSZ > 1024
+#if PACKETSZ > 65536
#define MAXPACKET PACKETSZ
#else
-#define MAXPACKET 1024
+#define MAXPACKET 65536
#endif
+#define QUERYSIZE (HFIXEDSZ + QFIXEDSZ + MAXCDNAME + 1)
+
+static int
+__libc_res_nquerydomain(res_state statp, const char *name, const char *domain,
+ int class, int type, u_char *answer, int anslen,
+ u_char **answerp, u_char **answerp2, int *nanswerp2,
+ int *resplen2, int *answerp2_malloced);
+
/*
* Formulate a normal query, send, and await answer.
* Returned answer is placed in supplied buffer "answer".
* 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 */
+__libc_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 **answerp, /* if buffer needs to be enlarged */
+ u_char **answerp2,
+ int *nanswerp2,
+ int *resplen2,
+ int *answerp2_malloced)
{
- u_char buf[MAXPACKET];
HEADER *hp = (HEADER *) answer;
- int n;
+ HEADER *hp2;
+ int n, use_malloc = 0;
+ u_int oflags = statp->_flags;
+
+ size_t bufsize = (type == T_UNSPEC ? 2 : 1) * QUERYSIZE;
+ u_char *buf = alloca (bufsize);
+ u_char *query1 = buf;
+ int nquery1 = -1;
+ u_char *query2 = NULL;
+ int nquery2 = 0;
+ again:
hp->rcode = NOERROR; /* default */
#ifdef 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));
- if (n <= 0) {
+ if (type == T_UNSPEC)
+ {
+ n = res_nmkquery(statp, QUERY, name, class, T_A, NULL, 0, NULL,
+ query1, bufsize);
+ if (n > 0)
+ {
+ if ((oflags & RES_F_EDNS0ERR) == 0
+ && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0)
+ {
+ n = __res_nopt(statp, n, query1, bufsize, anslen / 2);
+ if (n < 0)
+ goto unspec_nomem;
+ }
+
+ nquery1 = n;
+ /* Align the buffer. */
+ int npad = ((nquery1 + __alignof__ (HEADER) - 1)
+ & ~(__alignof__ (HEADER) - 1)) - nquery1;
+ if (n > bufsize - npad)
+ {
+ n = -1;
+ goto unspec_nomem;
+ }
+ int nused = n + npad;
+ query2 = buf + nused;
+ n = res_nmkquery(statp, QUERY, name, class, T_AAAA, NULL, 0,
+ NULL, query2, bufsize - nused);
+ if (n > 0
+ && (oflags & RES_F_EDNS0ERR) == 0
+ && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0)
+ n = __res_nopt(statp, n, query2, bufsize - nused - n,
+ anslen / 2);
+ nquery2 = n;
+ }
+
+ unspec_nomem:;
+ }
+ else
+ {
+ n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL,
+ query1, bufsize);
+
+ if (n > 0
+ && (oflags & RES_F_EDNS0ERR) == 0
+ && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0)
+ n = __res_nopt(statp, n, query1, bufsize, anslen);
+
+ nquery1 = n;
+ }
+
+ if (__builtin_expect (n <= 0, 0) && !use_malloc) {
+ /* Retry just in case res_nmkquery failed because of too
+ short buffer. Shouldn't happen. */
+ bufsize = (type == T_UNSPEC ? 2 : 1) * MAXPACKET;
+ buf = malloc (bufsize);
+ if (buf != NULL) {
+ query1 = buf;
+ use_malloc = 1;
+ goto again;
+ }
+ }
+ if (__glibc_unlikely (n <= 0)) {
+ /* If the query choked with EDNS0, retry without EDNS0. */
+ if ((statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0
+ && ((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) {
+ statp->_flags |= RES_F_EDNS0ERR;
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG)
+ printf(";; res_nquery: retry without EDNS0\n");
+#endif
+ goto again;
+ }
#ifdef DEBUG
if (statp->options & RES_DEBUG)
printf(";; res_query: mkquery failed\n");
#endif
RES_SET_H_ERRNO(statp, NO_RECOVERY);
+ if (use_malloc)
+ free (buf);
return (n);
}
- n = res_nsend(statp, buf, n, answer, anslen);
+ assert (answerp == NULL || (void *) *answerp == (void *) answer);
+ n = __libc_res_nsend(statp, query1, nquery1, query2, nquery2, answer,
+ anslen, answerp, answerp2, nanswerp2, resplen2,
+ answerp2_malloced);
+ if (use_malloc)
+ free (buf);
if (n < 0) {
#ifdef DEBUG
if (statp->options & RES_DEBUG)
return (n);
}
- if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
+ if (answerp != NULL)
+ /* __libc_res_nsend might have reallocated the buffer. */
+ hp = (HEADER *) *answerp;
+
+ /* We simplify the following tests by assigning HP to HP2 or
+ vice versa. It is easy to verify that this is the same as
+ ignoring all tests of HP or HP2. */
+ if (answerp2 == NULL || *resplen2 < (int) sizeof (HEADER))
+ {
+ hp2 = hp;
+ }
+ else
+ {
+ hp2 = (HEADER *) *answerp2;
+ if (n < (int) sizeof (HEADER))
+ {
+ hp = hp2;
+ }
+ }
+
+ /* Make sure both hp and hp2 are defined */
+ assert((hp != NULL) && (hp2 != NULL));
+
+ if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0)
+ && (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) {
#ifdef DEBUG
- if (statp->options & RES_DEBUG)
+ if (statp->options & RES_DEBUG) {
printf(";; rcode = %d, ancount=%d\n", hp->rcode,
ntohs(hp->ancount));
+ if (hp != hp2)
+ printf(";; rcode2 = %d, ancount2=%d\n", hp2->rcode,
+ ntohs(hp2->ancount));
+ }
#endif
- switch (hp->rcode) {
+ switch (hp->rcode == NOERROR ? hp2->rcode : hp->rcode) {
case NXDOMAIN:
+ if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0)
+ || (hp2->rcode == NOERROR
+ && ntohs (hp2->ancount) != 0))
+ goto success;
RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
break;
case SERVFAIL:
RES_SET_H_ERRNO(statp, TRY_AGAIN);
break;
case NOERROR:
+ if (ntohs (hp->ancount) != 0
+ || ntohs (hp2->ancount) != 0)
+ goto success;
RES_SET_H_ERRNO(statp, NO_DATA);
break;
case FORMERR:
case NOTIMP:
+ /* Servers must not reply to AAAA queries with
+ NOTIMP etc but some of them do. */
+ if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0)
+ || (hp2->rcode == NOERROR
+ && ntohs (hp2->ancount) != 0))
+ goto success;
+ /* FALLTHROUGH */
case REFUSED:
default:
RES_SET_H_ERRNO(statp, NO_RECOVERY);
}
return (-1);
}
+ success:
return (n);
}
+libresolv_hidden_def (__libc_res_nquery)
+
+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 */
+{
+ return __libc_res_nquery(statp, name, class, type, answer, anslen,
+ NULL, NULL, NULL, NULL, NULL);
+}
+libresolv_hidden_def (res_nquery)
/*
* Formulate a normal query, send, and retrieve answer in supplied buffer.
* 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 */
+__libc_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 */
+ u_char **answerp,
+ u_char **answerp2,
+ int *nanswerp2,
+ int *resplen2,
+ int *answerp2_malloced)
{
const char *cp, * const *domain;
HEADER *hp = (HEADER *) answer;
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;
__set_errno (0);
RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); /* True if we never query. */
/* 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));
+ return (__libc_res_nquery(statp, cp, class, type, answer,
+ anslen, answerp, answerp2,
+ nanswerp2, resplen2, answerp2_malloced));
+
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG)
+ printf("dots=%d, statp->ndots=%d, trailing_dot=%d, name=%s\n",
+ (int)dots,(int)statp->ndots,(int)trailing_dot,name);
+#endif
/*
* If there are enough dots in the name, let's just give it a
*/
saved_herrno = -1;
if (dots >= statp->ndots || trailing_dot) {
- ret = res_nquerydomain(statp, name, NULL, class, type,
- answer, anslen);
- if (ret > 0 || trailing_dot)
+ ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
+ answer, anslen, answerp,
+ answerp2, nanswerp2, resplen2,
+ answerp2_malloced);
+ if (ret > 0 || trailing_dot
+ /* If the second response is valid then we use that. */
+ || (ret == 0 && resplen2 != NULL && *resplen2 > 0))
return (ret);
saved_herrno = h_errno;
tried_as_is++;
+ if (answerp && *answerp != answer) {
+ answer = *answerp;
+ anslen = MAXPACKET;
+ }
+ if (answerp2 && *answerp2_malloced)
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ *answerp2_malloced = 0;
+ }
}
/*
for (domain = (const char * const *)statp->dnsrch;
*domain && !done;
domain++) {
+ const char *dname = domain[0];
+ searched = 1;
- if (domain[0][0] == '\0' ||
- (domain[0][0] == '.' && domain[0][1] == '\0'))
+ /* __libc_res_nquerydoman concatenates name
+ with dname with a "." in between. If we
+ pass it in dname the "." we got from the
+ configured default search path, we'll end
+ up with "name..", which won't resolve.
+ OTOH, passing it "" will result in "name.",
+ which has the intended effect for both
+ possible representations of the root
+ domain. */
+ if (dname[0] == '.')
+ dname++;
+ if (dname[0] == '\0')
root_on_list++;
- ret = res_nquerydomain(statp, name, *domain,
- class, type,
- answer, anslen);
- if (ret > 0)
+ ret = __libc_res_nquerydomain(statp, name, dname,
+ class, type,
+ answer, anslen, answerp,
+ answerp2, nanswerp2,
+ resplen2, answerp2_malloced);
+ if (ret > 0 || (ret == 0 && resplen2 != NULL
+ && *resplen2 > 0))
return (ret);
+ if (answerp && *answerp != answer) {
+ answer = *answerp;
+ anslen = MAXPACKET;
+ }
+ if (answerp2 && *answerp2_malloced)
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ *answerp2_malloced = 0;
+ }
+
/*
* If no server present, give up.
* If name isn't found in this domain,
}
/*
- * If the name has any dots at all, and no earlier 'as-is' query
- * for the name, and "." is not on the search list, then try an as-is
- * query now.
+ * If the query has not already been tried as is then try it
+ * unless RES_NOTLDQUERY is set and there were no dots.
*/
- if (statp->ndots && !(tried_as_is || root_on_list)) {
- ret = res_nquerydomain(statp, name, NULL, class, type,
- answer, anslen);
- if (ret > 0)
+ if ((dots || !searched || (statp->options & RES_NOTLDQUERY) == 0)
+ && !(tried_as_is || root_on_list)) {
+ ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
+ answer, anslen, answerp,
+ answerp2, nanswerp2, resplen2,
+ answerp2_malloced);
+ if (ret > 0 || (ret == 0 && resplen2 != NULL
+ && *resplen2 > 0))
return (ret);
}
* else send back meaningless H_ERRNO, that being the one from
* the last DNSRCH we did.
*/
+ if (answerp2 && *answerp2_malloced)
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ *answerp2_malloced = 0;
+ }
if (saved_herrno != -1)
RES_SET_H_ERRNO(statp, saved_herrno);
else if (got_nodata)
RES_SET_H_ERRNO(statp, TRY_AGAIN);
return (-1);
}
+libresolv_hidden_def (__libc_res_nsearch)
-/*
- * 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,
+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 */
+ u_char *answer, /* buffer to put answer */
int anslen) /* size of answer */
+{
+ return __libc_res_nsearch(statp, name, class, type, answer,
+ anslen, NULL, NULL, NULL, NULL, NULL);
+}
+libresolv_hidden_def (res_nsearch)
+
+/*
+ * Perform a call on res_query on the concatenation of name and domain.
+ */
+static int
+__libc_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 */
+ u_char **answerp,
+ u_char **answerp2,
+ int *nanswerp2,
+ int *resplen2,
+ int *answerp2_malloced)
{
char nbuf[MAXDNAME];
const char *longname = nbuf;
- int n, d;
+ size_t n, d;
#ifdef DEBUG
if (statp->options & RES_DEBUG)
name, domain?domain:"<Nil>", class, type);
#endif
if (domain == NULL) {
- /*
- * Check for trailing '.';
- * copy without '.' if present.
- */
n = strlen(name);
- if (n >= MAXDNAME) {
+
+ /* Decrement N prior to checking it against MAXDNAME
+ so that we detect a wrap to SIZE_MAX and return
+ a reasonable error. */
+ n--;
+ if (n >= MAXDNAME - 1) {
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;
+ longname = name;
} else {
n = strlen(name);
d = strlen(domain);
}
sprintf(nbuf, "%s.%s", name, domain);
}
- return (res_nquery(statp, longname, class, type, answer, anslen));
+ return (__libc_res_nquery(statp, longname, class, type, answer,
+ anslen, answerp, answerp2, nanswerp2,
+ resplen2, answerp2_malloced));
+}
+
+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 */
+{
+ return __libc_res_nquerydomain(statp, name, domain, class, type,
+ answer, anslen, NULL, NULL, NULL, NULL,
+ NULL);
}
+libresolv_hidden_def (res_nquerydomain)
const char *
res_hostalias(const res_state statp, const char *name, char *dst, size_t siz) {
if (statp->options & RES_NOALIASES)
return (NULL);
- file = __secure_getenv("HOSTALIASES");
- if (file == NULL || (fp = fopen(file, "r")) == NULL)
+ file = getenv("HOSTALIASES");
+ if (file == NULL || (fp = fopen(file, "rce")) == NULL)
return (NULL);
setbuf(fp, NULL);
buf[sizeof(buf) - 1] = '\0';
fclose(fp);
return (NULL);
}
+libresolv_hidden_def (res_hostalias)
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