Attachment 13868 Details for Bug 13191 – possible patch for master and 4.7

[patch] possible patch for master and 4.7

dns-wildcard-performance.patch.txt (text/plain), 4.52 KB, created by Andrew Bartlett on 2017-12-14 23:43:08 UTC

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Creator: Andrew Bartlett

Created: 2017-12-14 23:43:08 UTC

Size: 4.52 KB

patch

obsolete

>From b8f7342774507350b7897a82030ddfeee57ccf11 Mon Sep 17 00:00:00 2001
>From: Andrew Bartlett <abartlet@samba.org>
>Date: Fri, 15 Dec 2017 11:40:28 +1300
>Subject: [PATCH 1/3] dns_server: Do not look for a wildcard for @
>
>This query is made for every record returned via BIND9 DLZ.
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=13191
>
>Signed-off-by: Andrew Bartlett <abartlet@samba.org>
>---
> source4/dns_server/dnsserver_common.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
>diff --git a/source4/dns_server/dnsserver_common.c b/source4/dns_server/dnsserver_common.c
>index 217e65b39f4..093898361d0 100644
>--- a/source4/dns_server/dnsserver_common.c
>+++ b/source4/dns_server/dnsserver_common.c
>@@ -547,6 +547,16 @@ WERROR dns_common_wildcard_lookup(struct ldb_context *samdb,
> 		return DNS_ERR(NAME_ERROR);
> 	}
> 
>+	/* Don't look for a wildcard for @ */
>+	if (name->length == 1 && name->data[0] == '@') {
>+		return dns_common_lookup(samdb,
>+					 mem_ctx,
>+					 dn,
>+					 records,
>+					 num_records,
>+					 NULL);
>+	}
>+
> 	werr =  dns_name_check(
> 			mem_ctx,
> 			strlen((const char*)name->data),
>-- 
>2.11.0
>
>
>From 9a22603499230e51dd8173a2ebd31c63e6c8911f Mon Sep 17 00:00:00 2001
>From: Andrew Bartlett <abartlet@samba.org>
>Date: Fri, 15 Dec 2017 11:41:15 +1300
>Subject: [PATCH 2/3] dns_server: Do not embed a trailing NUL in the query
>
>The data to match on does not include the NUL, just the significant bytes
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=13191
>
>Signed-off-by: Andrew Bartlett <abartlet@samba.org>
>---
> source4/dns_server/dnsserver_common.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
>diff --git a/source4/dns_server/dnsserver_common.c b/source4/dns_server/dnsserver_common.c
>index 093898361d0..574d1510230 100644
>--- a/source4/dns_server/dnsserver_common.c
>+++ b/source4/dns_server/dnsserver_common.c
>@@ -250,9 +250,11 @@ static struct ldb_parse_tree *build_equality_operation(
> 	struct ldb_parse_tree *el = NULL;  /* Equality node being built */
> 	struct ldb_val *value = NULL;      /* Value the attr will be compared
> 					      with */
>-	size_t length = 0;                 /* calculated length of the value
>-	                                      including option '*' prefix and
>-					      '\0' string terminator */
>+	size_t length = 0;                 /* calculated length of the
>+	                                      value including option
>+	                                      '*' prefix but no '\0'
>+	                                      string terminator (this
>+	                                      is an ldb_val) */
> 
> 	el = talloc(mem_ctx, struct ldb_parse_tree);
> 	if (el == NULL) {
>@@ -263,7 +265,7 @@ static struct ldb_parse_tree *build_equality_operation(
> 	el->operation = LDB_OP_EQUALITY;
> 	el->u.equality.attr = talloc_strdup(mem_ctx, attr);
> 	value = &el->u.equality.value;
>-	length = (add_asterix) ? size + 2 : size + 1;
>+	length = (add_asterix) ? size + 1 : size;
> 	value->data = talloc_zero_array(el, uint8_t, length);
> 	if (el == NULL) {
> 		DBG_ERR("Unable to allocate value->data\n");
>-- 
>2.11.0
>
>
>From 007efcf5d9cc15a200581ff7c8f24137ec0e5a8e Mon Sep 17 00:00:00 2001
>From: Andrew Bartlett <abartlet@samba.org>
>Date: Fri, 15 Dec 2017 12:30:50 +1300
>Subject: [PATCH 3/3] dns_server: Do the exact match query first, then do the
> wildcard lookup
>
>The wildcard lookup is SCOPE_ONELEVEL which in current ldb will load the full index for that zone.
>
>This is inefficient as we do not currently intersect that index with the
>index on DN=
>
>Not that a not-found and wildcard response will still go via the ONELEVEL
>index for now so this only helps for correct, directly matching queries.
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=13191
>
>Signed-off-by: Andrew Bartlett <abartlet@samba.org>
>---
> source4/dns_server/dnsserver_common.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
>diff --git a/source4/dns_server/dnsserver_common.c b/source4/dns_server/dnsserver_common.c
>index 574d1510230..368d32326b0 100644
>--- a/source4/dns_server/dnsserver_common.c
>+++ b/source4/dns_server/dnsserver_common.c
>@@ -567,6 +567,20 @@ WERROR dns_common_wildcard_lookup(struct ldb_context *samdb,
> 		return werr;
> 	}
> 
>+	/* 
>+	 * Do a point search first, then fall back to a wildcard
>+	 * lookup if it does not exist
>+	 */
>+	werr = dns_common_lookup(samdb,
>+				 mem_ctx,
>+				 dn,
>+				 records,
>+				 num_records,
>+				 NULL);
>+	if (!W_ERROR_EQUAL(werr, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
>+		return werr;
>+	}
>+	
> 	ret = dns_wildcard_lookup(samdb, mem_ctx, dn, &msg);
> 	if (ret == LDB_ERR_OPERATIONS_ERROR) {
> 		return DNS_ERR(SERVER_FAILURE);
>-- 
>2.11.0
>

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Attachments on bug 13191: 13868 | 13879 | 13880