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Diffstat (limited to 'resolv/res_query.c')
-rw-r--r--resolv/res_query.c149
1 files changed, 114 insertions, 35 deletions
diff --git a/resolv/res_query.c b/resolv/res_query.c
index 4371af5b05..a8e8d7b739 100644
--- a/resolv/res_query.c
+++ b/resolv/res_query.c
@@ -97,7 +97,7 @@ static const char rcsid[] = "$BINDId: res_query.c,v 8.20 2000/02/29 05:39:12 vix
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 **answerp, u_char **answerp2, int *nanswerp2);
/*
* Formulate a normal query, send, and await answer.
@@ -115,15 +115,20 @@ __libc_res_nquery(res_state statp,
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 **answerp, /* if buffer needs to be enlarged */
+ u_char **answerp2,
+ int *nanswerp2)
{
- u_char *buf;
HEADER *hp = (HEADER *) answer;
int n, use_malloc = 0;
u_int oflags = statp->_flags;
- size_t bufsize = QUERYSIZE;
- buf = alloca (bufsize);
+ 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 */
@@ -133,18 +138,47 @@ __libc_res_nquery(res_state statp,
printf(";; res_query(%s, %d, %d)\n", name, class, type);
#endif
- n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL,
- buf, bufsize);
- if (n > 0
- && (oflags & RES_F_EDNS0ERR) == 0
- && (statp->options & RES_USE_EDNS0) != 0)
- n = __res_nopt(statp, n, buf, bufsize, anslen);
+ 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) != 0)
+ n = __res_nopt(statp, n, query1, bufsize, anslen / 2);
+
+ nquery1 = n;
+ query2 = buf + nquery1;
+ n = res_nmkquery(statp, QUERY, name, class, T_AAAA, NULL, 0,
+ NULL, query2, bufsize - n);
+ if (n > 0
+ && (oflags & RES_F_EDNS0ERR) == 0
+ && (statp->options & RES_USE_EDNS0) != 0)
+ n = __res_nopt(statp, n, query2, bufsize - n, anslen / 2);
+ nquery2 = n;
+ }
+ }
+ 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) != 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 = MAXPACKET;
+ bufsize = (type == T_UNSPEC ? 2 : 1) * MAXPACKET;
buf = malloc (bufsize);
if (buf != NULL) {
+ query1 = buf;
use_malloc = 1;
goto again;
}
@@ -168,7 +202,8 @@ __libc_res_nquery(res_state statp,
return (n);
}
assert (answerp == NULL || (void *) *answerp == (void *) answer);
- n = __libc_res_nsend(statp, buf, n, answer, anslen, answerp);
+ n = __libc_res_nsend(statp, query1, nquery1, query2, nquery2, answer,
+ anslen, answerp, answerp2, nanswerp2);
if (use_malloc)
free (buf);
if (n < 0) {
@@ -184,20 +219,37 @@ __libc_res_nquery(res_state statp,
/* __libc_res_nsend might have reallocated the buffer. */
hp = (HEADER *) *answerp;
- if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
+ /* We simplify the following tests by assigning HP to HP2. It
+ is easy to verify that this is the same as ignoring all
+ tests of HP2. */
+ HEADER *hp2 = answerp2 ? (HEADER *) *answerp2 : hp;
+
+ 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:
@@ -209,6 +261,7 @@ __libc_res_nquery(res_state statp,
}
return (-1);
}
+ success:
return (n);
}
libresolv_hidden_def (__libc_res_nquery)
@@ -221,7 +274,7 @@ res_nquery(res_state statp,
int anslen) /* size of answer buffer */
{
return __libc_res_nquery(statp, name, class, type, answer, anslen,
- NULL);
+ NULL, NULL, NULL);
}
libresolv_hidden_def (res_nquery)
@@ -233,11 +286,13 @@ libresolv_hidden_def (res_nquery)
*/
int
__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)
+ 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)
{
const char *cp, * const *domain;
HEADER *hp = (HEADER *) answer;
@@ -260,7 +315,8 @@ __libc_res_nsearch(res_state statp,
/* 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 (__libc_res_nquery(statp, cp, class, type, answer,
- anslen, answerp));
+ anslen, answerp, answerp2,
+ nanswerp2));
#ifdef DEBUG
if (statp->options & RES_DEBUG)
@@ -276,7 +332,8 @@ __libc_res_nsearch(res_state statp,
saved_herrno = -1;
if (dots >= statp->ndots || trailing_dot) {
ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
- answer, anslen, answerp);
+ answer, anslen, answerp,
+ answerp2, nanswerp2);
if (ret > 0 || trailing_dot)
return (ret);
saved_herrno = h_errno;
@@ -285,6 +342,12 @@ __libc_res_nsearch(res_state statp,
answer = *answerp;
anslen = MAXPACKET;
}
+ if (answerp2
+ && (*answerp2 < answer || *answerp2 >= answer + anslen))
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ }
}
/*
@@ -307,7 +370,8 @@ __libc_res_nsearch(res_state statp,
ret = __libc_res_nquerydomain(statp, name, *domain,
class, type,
- answer, anslen, answerp);
+ answer, anslen, answerp,
+ answerp2, nanswerp2);
if (ret > 0)
return (ret);
@@ -315,6 +379,13 @@ __libc_res_nsearch(res_state statp,
answer = *answerp;
anslen = MAXPACKET;
}
+ if (answerp2
+ && (*answerp2 < answer
+ || *answerp2 >= answer + anslen))
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ }
/*
* If no server present, give up.
@@ -368,7 +439,8 @@ __libc_res_nsearch(res_state statp,
*/
if (dots && !(tried_as_is || root_on_list)) {
ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
- answer, anslen, answerp);
+ answer, anslen, answerp,
+ answerp2, nanswerp2);
if (ret > 0)
return (ret);
}
@@ -380,6 +452,11 @@ __libc_res_nsearch(res_state statp,
* else send back meaningless H_ERRNO, that being the one from
* the last DNSRCH we did.
*/
+ if (answerp2 && (*answerp2 < answer || *answerp2 >= answer + anslen))
+ {
+ free (*answerp2);
+ *answerp2 = NULL;
+ }
if (saved_herrno != -1)
RES_SET_H_ERRNO(statp, saved_herrno);
else if (got_nodata)
@@ -398,7 +475,7 @@ res_nsearch(res_state statp,
int anslen) /* size of answer */
{
return __libc_res_nsearch(statp, name, class, type, answer,
- anslen, NULL);
+ anslen, NULL, NULL, NULL);
}
libresolv_hidden_def (res_nsearch)
@@ -408,12 +485,14 @@ libresolv_hidden_def (res_nsearch)
*/
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)
+ 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)
{
char nbuf[MAXDNAME];
const char *longname = nbuf;
@@ -450,7 +529,7 @@ __libc_res_nquerydomain(res_state statp,
sprintf(nbuf, "%s.%s", name, domain);
}
return (__libc_res_nquery(statp, longname, class, type, answer,
- anslen, answerp));
+ anslen, answerp, answerp2, nanswerp2));
}
int
@@ -462,7 +541,7 @@ res_nquerydomain(res_state statp,
int anslen) /* size of answer */
{
return __libc_res_nquerydomain(statp, name, domain, class, type,
- answer, anslen, NULL);
+ answer, anslen, NULL, NULL, NULL);
}
libresolv_hidden_def (res_nquerydomain)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 09:22:05 +0000