Do not take external buffers for storing DNS responses in the internal

async API.  That is actually useless and it makes the code more
complicated.  The required buffers are always allocated when needed.

12 files changed, 55 insertions, 122 deletions

diff --git a/lib/libc/asr/asr.c b/lib/libc/asr/asr.c
index 5bde5097142..1aea2bd4e7c 100644
--- a/lib/libc/asr/asr.c
+++ b/lib/libc/asr/asr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: asr.c,v 1.24 2013/04/17 19:13:23 otto Exp $	*/
+/*	$OpenBSD: asr.c,v 1.25 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2010-2012 Eric Faurot <eric@openbsd.org>
  *
@@ -277,7 +277,7 @@ async_free(struct async *as)
 			close(as->as_fd);
 		if (as->as.dns.obuf && !(as->as.dns.flags & ASYNC_EXTOBUF))
 			free(as->as.dns.obuf);
-		if (as->as.dns.ibuf && !(as->as.dns.flags & ASYNC_EXTIBUF))
+		if (as->as.dns.ibuf)
 			free(as->as.dns.ibuf);
 		if (as->as.dns.dname)
 			free(as->as.dns.dname);
diff --git a/lib/libc/asr/asr.h b/lib/libc/asr/asr.h
index 8f9f11729c6..b0513b8f167 100644
--- a/lib/libc/asr/asr.h
+++ b/lib/libc/asr/asr.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: asr.h,v 1.5 2013/04/01 15:49:54 deraadt Exp $	*/
+/*	$OpenBSD: asr.h,v 1.6 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -80,12 +80,9 @@ void	    async_resolver_done(struct asr *);
 
 /* Async version of the resolver API */
 
-struct async *res_send_async(const unsigned char *, int, unsigned char *, int,
-    struct asr *);
-struct async *res_query_async(const char *, int, int, unsigned char *, int,
-    struct asr *);
-struct async *res_search_async(const char *, int, int, unsigned char *, int,
-    struct asr *);
+struct async *res_send_async(const unsigned char *, int, struct asr *);
+struct async *res_query_async(const char *, int, int, struct asr *);
+struct async *res_search_async(const char *, int, int, struct asr *);
 
 struct async *getrrsetbyname_async(const char *, unsigned int, unsigned int,
     unsigned int, struct asr *);
diff --git a/lib/libc/asr/asr_private.h b/lib/libc/asr/asr_private.h
index f5f524c77f1..275d18eb576 100644
--- a/lib/libc/asr/asr_private.h
+++ b/lib/libc/asr/asr_private.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: asr_private.h,v 1.16 2013/04/02 16:38:37 eric Exp $	*/
+/*	$OpenBSD: asr_private.h,v 1.17 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -164,7 +164,6 @@ struct asr {
 #define	ASYNC_NODATA		0x00000100
 #define	ASYNC_AGAIN		0x00000200
 
-#define	ASYNC_EXTIBUF		0x00001000
 #define	ASYNC_EXTOBUF		0x00002000
 
 
@@ -217,9 +216,6 @@ struct async {
 			char		*name;
 			struct async	*subq;
 			int		 saved_h_errno;
-			unsigned char	*ibuf;
-			size_t		 ibuflen;
-			size_t		 ibufsize;
 		} search;
 
 		struct {
@@ -330,10 +326,8 @@ int asr_iter_domain(struct async *, const char *, char *, size_t);
 int asr_parse_namedb_line(FILE *, char **, int);
 
 /* <*>_async.h */
-struct async *res_query_async_ctx(const char *, int, int, unsigned char *, int,
-    struct asr_ctx *);
-struct async *res_search_async_ctx(const char *, int, int, unsigned char *, int,
-    struct asr_ctx *);
+struct async *res_query_async_ctx(const char *, int, int, struct asr_ctx *);
+struct async *res_search_async_ctx(const char *, int, int, struct asr_ctx *);
 struct async *gethostbyaddr_async_ctx(const void *, socklen_t, int,
     struct asr_ctx *);
 
diff --git a/lib/libc/asr/async_resolver.3 b/lib/libc/asr/async_resolver.3
index 38f71f4ca81..10216920faf 100644
--- a/lib/libc/asr/async_resolver.3
+++ b/lib/libc/asr/async_resolver.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: async_resolver.3,v 1.10 2013/04/01 15:49:54 deraadt Exp $
+.\"	$OpenBSD: async_resolver.3,v 1.11 2013/04/30 12:02:39 eric Exp $
 .\"
 .\" Copyright (c) 2012, Eric Faurot <eric@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: April 1 2013 $
+.Dd $Mdocdate: April 30 2013 $
 .Dt ASYN_RESOLVER 3
 .Os
 .Sh NAME
@@ -49,9 +49,11 @@
 .Ft void
 .Fn async_abort "struct async *as"
 .Ft struct async *
-.Fn res_send_async "const unsigned char *pkt" "int pktlen" "unsigned char *ans" "int anslen" "struct asr *asr"
+.Fn res_send_async "const unsigned char *pkt" "int pktlen" "struct asr *asr"
 .Ft struct async *
-.Fn res_query_async "const char *name" "int class" "int type" "unsigned char *ans" "int anslen" "struct asr *asr"
+.Fn res_query_async "const char *name" "int class" "int type" "struct asr *asr"
+.Ft struct async *
+.Fn res_search_async "const char *name" "int class" "int type" "struct asr *asr"
 .Ft struct async *
 .Fn getrrsetbyname_async "const char *hostname" "unsigned int rdclass" "unsigned int rdtype" "unsigned int flags" "struct asr *asr"
 .Ft struct async *
@@ -255,8 +257,8 @@ The
 and
 .Fn res_search_async
 functions are asynchronous versions of the standard libc resolver routines.
-Their interface is very similar, except that they take a resolver context as
-last argument, and the return value is found upon completion in the
+Their interface is very similar, except that the response buffer is always
+allocated internally.  The return value is found upon completion in the
 .Fa ar_datalen
 member of the response structure.
 In addition, the
@@ -266,8 +268,8 @@ union contains the address of the DNS server that sent the response,
 contains the code returned by the server in the DNS response packet, and
 .Fa ar_count
 contains the number of answers in the packet.
-If no answer buffer is provided, a new one is allocated to fit the response
-and returned as the
+If a response is received it placed in a newly allocated buffer
+and returned as
 .Fa ar_data
 member.
 This buffer must be freed by the caller.
diff --git a/lib/libc/asr/getaddrinfo_async.c b/lib/libc/asr/getaddrinfo_async.c
index 68824865714..30b2a6b1e41 100644
--- a/lib/libc/asr/getaddrinfo_async.c
+++ b/lib/libc/asr/getaddrinfo_async.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getaddrinfo_async.c,v 1.16 2013/04/30 06:53:07 eric Exp $	*/
+/*	$OpenBSD: getaddrinfo_async.c,v 1.17 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -296,13 +296,13 @@ getaddrinfo_async_run(struct async *as, struct async_res *ar)
 			if (as->as.ai.fqdn) {
 				as->as.ai.subq = res_query_async_ctx(
 				    as->as.ai.fqdn, C_IN,
-				    (family == AF_INET6) ? T_AAAA : T_A, NULL, 0,
+				    (family == AF_INET6) ? T_AAAA : T_A,
 				    as->as_ctx);
 			}
 			else {
 				as->as.ai.subq = res_search_async_ctx(
 				    as->as.ai.hostname, C_IN,
-				    (family == AF_INET6) ? T_AAAA : T_A, NULL, 0,
+				    (family == AF_INET6) ? T_AAAA : T_A,
 				    as->as_ctx);
 			}
 			if (as->as.ai.subq == NULL) {
diff --git a/lib/libc/asr/gethostnamadr_async.c b/lib/libc/asr/gethostnamadr_async.c
index 1cbd1289e6e..2dd251382bf 100644
--- a/lib/libc/asr/gethostnamadr_async.c
+++ b/lib/libc/asr/gethostnamadr_async.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gethostnamadr_async.c,v 1.18 2013/04/14 22:23:08 deraadt Exp $	*/
+/*	$OpenBSD: gethostnamadr_async.c,v 1.19 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -216,13 +216,13 @@ gethostnamadr_async_run(struct async *as, struct async_res *ar)
 				    T_A : T_AAAA;
 				as->as.hostnamadr.subq = res_search_async_ctx(
 				    as->as.hostnamadr.name,
-				    C_IN, type, NULL, 0, as->as_ctx);
+				    C_IN, type, as->as_ctx);
 			} else {
 				addr_as_fqdn(as->as.hostnamadr.addr,
 				    as->as.hostnamadr.family,
 				    dname, sizeof(dname));
 				as->as.hostnamadr.subq = res_query_async_ctx(
-				    dname, C_IN, T_PTR, NULL, 0, as->as_ctx);
+				    dname, C_IN, T_PTR, as->as_ctx);
 			}
 
 			if (as->as.hostnamadr.subq == NULL) {
diff --git a/lib/libc/asr/getnetnamadr_async.c b/lib/libc/asr/getnetnamadr_async.c
index 644ba66ca0e..c7da0cf4b82 100644
--- a/lib/libc/asr/getnetnamadr_async.c
+++ b/lib/libc/asr/getnetnamadr_async.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getnetnamadr_async.c,v 1.8 2013/04/01 15:49:54 deraadt Exp $	*/
+/*	$OpenBSD: getnetnamadr_async.c,v 1.9 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -148,7 +148,7 @@ getnetnamadr_async_run(struct async *as, struct async_res *ar)
 				type = T_PTR;
 				name = as->as.netnamadr.name;
 				as->as.netnamadr.subq = res_search_async_ctx(
-				    name, C_IN, type, NULL, 0, as->as_ctx);
+				    name, C_IN, type, as->as_ctx);
 			} else {
 				type = T_PTR;
 				name = dname;
@@ -158,7 +158,7 @@ getnetnamadr_async_run(struct async *as, struct async_res *ar)
 				    as->as.netnamadr.family,
 				    dname, sizeof(dname));
 				as->as.netnamadr.subq = res_query_async_ctx(
-				    name, C_IN, type, NULL, 0, as->as_ctx);
+				    name, C_IN, type, as->as_ctx);
 			}
 
 			if (as->as.netnamadr.subq == NULL) {
diff --git a/lib/libc/asr/getrrsetbyname_async.c b/lib/libc/asr/getrrsetbyname_async.c
index 540d13bd4fe..1e0e77617dc 100644
--- a/lib/libc/asr/getrrsetbyname_async.c
+++ b/lib/libc/asr/getrrsetbyname_async.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getrrsetbyname_async.c,v 1.3 2012/11/24 15:12:48 eric Exp $	*/
+/*	$OpenBSD: getrrsetbyname_async.c,v 1.4 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -97,7 +97,7 @@ getrrsetbyname_async_run(struct async *as, struct async_res *ar)
 		    as->as.rrset.name,
 		    as->as.rrset.class,
 		    as->as.rrset.type,
-		    NULL, 0, as->as_ctx);
+		    as->as_ctx);
 		if (as->as.rrset.subq == NULL) {
 			ar->ar_rrset_errno = ERRSET_FAIL;
 			async_set_state(as, ASR_STATE_HALT);
@@ -169,7 +169,7 @@ getrrsetbyname_async_run(struct async *as, struct async_res *ar)
 
 /* The rest of this file is taken from the orignal implementation. */
 
-/* $OpenBSD: getrrsetbyname_async.c,v 1.3 2012/11/24 15:12:48 eric Exp $ */
+/* $OpenBSD: getrrsetbyname_async.c,v 1.4 2013/04/30 12:02:39 eric Exp $ */
 
 /*
  * Copyright (c) 2001 Jakob Schlyter. All rights reserved.
diff --git a/lib/libc/asr/res_query.c b/lib/libc/asr/res_query.c
index 7351c8750a5..7a6a1db0ca4 100644
--- a/lib/libc/asr/res_query.c
+++ b/lib/libc/asr/res_query.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: res_query.c,v 1.2 2013/04/08 20:03:15 eric Exp $	*/
+/*	$OpenBSD: res_query.c,v 1.3 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -37,7 +37,7 @@ res_query(const char *name, int class, int type, u_char *ans, int anslen)
 		return (-1);
 	}
 
-	as = res_query_async(name, class, type, NULL, 0, NULL);
+	as = res_query_async(name, class, type, NULL);
 	if (as == NULL) {
 		if (errno == EINVAL)
 			h_errno = NO_RECOVERY;
@@ -77,7 +77,7 @@ res_search(const char *name, int class, int type, u_char *ans, int anslen)
 		return (-1);
 	}
 
-	as = res_search_async(name, class, type, NULL, 0, NULL);
+	as = res_search_async(name, class, type, NULL);
 	if (as == NULL) {
 		if (errno == EINVAL)
 			h_errno = NO_RECOVERY;
diff --git a/lib/libc/asr/res_search_async.c b/lib/libc/asr/res_search_async.c
index fae802f5e93..060a545eafa 100644
--- a/lib/libc/asr/res_search_async.c
+++ b/lib/libc/asr/res_search_async.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: res_search_async.c,v 1.6 2013/04/01 20:22:27 eric Exp $	*/
+/*	$OpenBSD: res_search_async.c,v 1.7 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -25,13 +25,6 @@
 #include <string.h>
 #include <unistd.h>
 
-/*
- * TODO:
- *
- * - make it possible to reuse ibuf if it was NULL when first called,
- *   to avoid reallocating buffers everytime.
- */
-
 #include "asr.h"
 #include "asr_private.h"
 
@@ -42,8 +35,7 @@ static int res_search_async_run(struct async *, struct async_res *);
  * h_errno is NETDB_SUCCESS.
  */
 struct async *
-res_search_async(const char *name, int class, int type, unsigned char *ans,
-	int anslen, struct asr *asr)
+res_search_async(const char *name, int class, int type, struct asr *asr)
 {
 	struct asr_ctx	*ac;
 	struct async	*as;
@@ -51,15 +43,14 @@ res_search_async(const char *name, int class, int type, unsigned char *ans,
 	DPRINT("asr: res_search_async(\"%s\", %i, %i)\n", name, class, type);
 
 	ac = asr_use_resolver(asr);
-	as = res_search_async_ctx(name, class, type, ans, anslen, ac);
+	as = res_search_async_ctx(name, class, type, ac);
 	asr_ctx_unref(ac);
 
 	return (as);
 }
 
 struct async *
-res_search_async_ctx(const char *name, int class, int type, unsigned char *ans,
-	int anslen, struct asr_ctx *ac)
+res_search_async_ctx(const char *name, int class, int type, struct asr_ctx *ac)
 {
 	struct async	*as;
 
@@ -72,16 +63,6 @@ res_search_async_ctx(const char *name, int class, int type, unsigned char *ans,
 	if ((as->as.search.name = strdup(name)) == NULL)
 		goto err; /* errno set */
 
-	if (ans) {
-		as->as.search.flags |= ASYNC_EXTIBUF;
-		as->as.search.ibuf = ans;
-		as->as.search.ibufsize = anslen;
-	} else {
-		as->as.search.ibuf = NULL;
-		as->as.search.ibufsize = 0;
-	}
-	as->as.search.ibuflen = 0;
-
 	as->as.search.class = class;
 	as->as.search.type = type;
 
@@ -130,8 +111,7 @@ res_search_async_run(struct async *as, struct async_res *ar)
 			break;
 		}
 		as->as.search.subq = res_query_async_ctx(fqdn,
-		    as->as.search.class, as->as.search.type,
-		    as->as.search.ibuf, as->as.search.ibufsize, as->as_ctx);
+		    as->as.search.class, as->as.search.type, as->as_ctx);
 		if (as->as.search.subq == NULL) {
 			ar->ar_errno = errno;
 			if (errno == EINVAL)
@@ -169,12 +149,7 @@ res_search_async_run(struct async *as, struct async_res *ar)
 			break;
 		}
 
-		/*
-		 * If we don't use an external buffer, the packet was allocated
-		 * by the subquery and it must be freed now.
-		 */
-		if ((as->as.search.flags & ASYNC_EXTIBUF) == 0)
-			free(ar->ar_data);
+		free(ar->ar_data);
 
 		/*
 		 * The original resolver does something like this.
diff --git a/lib/libc/asr/res_send.c b/lib/libc/asr/res_send.c
index d1379c6a67b..5135a8d15da 100644
--- a/lib/libc/asr/res_send.c
+++ b/lib/libc/asr/res_send.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: res_send.c,v 1.2 2013/04/08 20:03:15 eric Exp $	*/
+/*	$OpenBSD: res_send.c,v 1.3 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -36,7 +36,7 @@ res_send(const u_char *buf, int buflen, u_char *ans, int anslen)
 		return (-1);
 	}
 
-	as = res_send_async(buf, buflen, NULL, 0, NULL);
+	as = res_send_async(buf, buflen, NULL);
 	if (as == NULL)
 		return (-1); /* errno set */
 
diff --git a/lib/libc/asr/res_send_async.c b/lib/libc/asr/res_send_async.c
index 7a91d190b83..2a661a12e95 100644
--- a/lib/libc/asr/res_send_async.c
+++ b/lib/libc/asr/res_send_async.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: res_send_async.c,v 1.16 2013/04/14 22:23:08 deraadt Exp $	*/
+/*	$OpenBSD: res_send_async.c,v 1.17 2013/04/30 12:02:39 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -49,8 +49,7 @@ static int ensure_ibuf(struct async *, size_t);
 
 
 struct async *
-res_send_async(const unsigned char *buf, int buflen, unsigned char *ans,
-	int anslen, struct asr *asr)
+res_send_async(const unsigned char *buf, int buflen, struct asr *asr)
 {
 	struct asr_ctx  *ac;
 	struct async	*as;
@@ -67,17 +66,6 @@ res_send_async(const unsigned char *buf, int buflen, unsigned char *ans,
 	}
 	as->as_run = res_send_async_run;
 
-	if (ans) {
-		as->as.dns.flags |= ASYNC_EXTIBUF;
-		as->as.dns.ibuf = ans;
-		as->as.dns.ibufsize = anslen;
-		as->as.dns.ibuflen = 0;
-	} else {
-		as->as.dns.ibuf = NULL;
-		as->as.dns.ibufsize = 0;
-		as->as.dns.ibuflen = 0;
-	}
-
 	as->as.dns.flags |= ASYNC_EXTOBUF;
 	as->as.dns.obuf = (unsigned char *)buf;
 	as->as.dns.obuflen = buflen;
@@ -113,8 +101,7 @@ res_send_async(const unsigned char *buf, int buflen, unsigned char *ans,
  * (ans == NULL).
  */
 struct async *
-res_query_async(const char *name, int class, int type, unsigned char *ans,
-	int anslen, struct asr *asr)
+res_query_async(const char *name, int class, int type, struct asr *asr)
 {
 	struct asr_ctx	*ac;
 	struct async	*as;
@@ -122,15 +109,14 @@ res_query_async(const char *name, int class, int type, unsigned char *ans,
 	DPRINT("asr: res_query_async(\"%s\", %i, %i)\n", name, class, type);
 
 	ac = asr_use_resolver(asr);
-	as = res_query_async_ctx(name, class, type, ans, anslen, ac);
+	as = res_query_async_ctx(name, class, type, ac);
 	asr_ctx_unref(ac);
 
 	return (as);
 }
 
 struct async *
-res_query_async_ctx(const char *name, int class, int type, unsigned char *ans,
-	int anslen, struct asr_ctx *a_ctx)
+res_query_async_ctx(const char *name, int class, int type, struct asr_ctx *a_ctx)
 {
 	struct async	*as;
 
@@ -140,16 +126,6 @@ res_query_async_ctx(const char *name, int class, int type, unsigned char *ans,
 		return (NULL); /* errno set */
 	as->as_run = res_send_async_run;
 
-	if (ans) {
-		as->as.dns.flags |= ASYNC_EXTIBUF;
-		as->as.dns.ibuf = ans;
-		as->as.dns.ibufsize = anslen;
-	} else {
-		as->as.dns.ibuf = NULL;
-		as->as.dns.ibufsize = 0;
-	}
-	as->as.dns.ibuflen = 0;
-
 	/* This adds a "." to name if it doesn't already has one.
 	 * That's how res_query() behaves (through res_mkquery").
 	 */
@@ -478,15 +454,12 @@ udp_recv(struct async *as)
 	ssize_t		 n;
 	int		 save_errno;
 
-	/* Allocate input buf if needed */
-	if (as->as.dns.ibuf == NULL) {
-		if (ensure_ibuf(as, PACKETSZ) == -1) {
-			save_errno = errno;
-			close(as->as_fd);
-			errno = save_errno;
-			as->as_fd = -1;
-			return (-1);
-		}
+	if (ensure_ibuf(as, PACKETSZ) == -1) {
+		save_errno = errno;
+		close(as->as_fd);
+		errno = save_errno;
+		as->as_fd = -1;
+		return (-1);
 	}
 
 	n = recv(as->as_fd, as->as.dns.ibuf, as->as.dns.ibufsize, 0);
@@ -664,22 +637,14 @@ close:
 }
 
 /*
- * Make sure the input buffer is at least "n" bytes long.
- * If not (or not allocated) allocated enough space, unless the
- * buffer is external (owned by the caller), in which case it fails.
+ * Make sure the input buffer is at least "n" bytes long, and allocate or
+ * extend it if necessary. Return 0 on success, or set errno and return -1.
  */
 static int
 ensure_ibuf(struct async *as, size_t n)
 {
 	char	*t;
 
-	if (as->as.dns.flags & ASYNC_EXTIBUF) {
-		if (n <= as->as.dns.ibufsize)
-			return (0);
-		errno = EINVAL;
-		return (-1);
-	}
-
 	if (as->as.dns.ibuf == NULL) {
 		as->as.dns.ibuf = malloc(n);
 		if (as->as.dns.ibuf == NULL)