Attachment 7468 Details for Bug 8880 – Proposed patch to fix

[patch] Proposed patch to fix

0001-Hack-to-work-around-DNS-not-returning-a-coresponding.patch (text/plain), 2.98 KB, created by Matthieu Patou on 2012-04-19 07:44:30 UTC

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Creator: Matthieu Patou

Created: 2012-04-19 07:44:30 UTC

Size: 2.98 KB

patch

obsolete

>From 630e1ab06a81f3467149ae6d7973a26e45ecf2ae Mon Sep 17 00:00:00 2001
>From: Matthieu Patou <mat@matws.net>
>Date: Wed, 18 Apr 2012 02:18:19 -0700
>Subject: [PATCH] Hack to work around DNS not returning a coresponding A(AAA)
> record for CNAMEs when A(AAA) record is asked for
>
>---
> source4/dns_server/dns_query.c |   54 +++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 53 insertions(+), 1 deletions(-)
>
>diff --git a/source4/dns_server/dns_query.c b/source4/dns_server/dns_query.c
>index b3984a4..90bef41 100644
>--- a/source4/dns_server/dns_query.c
>+++ b/source4/dns_server/dns_query.c
>@@ -186,6 +186,7 @@ static WERROR handle_question(struct dns_server *dns,
> 	struct dnsp_DnssrvRpcRecord *recs;
> 	uint16_t rec_count, ai = 0;
> 	struct ldb_dn *dn = NULL;
>+	unsigned int ans_size;
> 
> 	werror = dns_name2dn(dns, mem_ctx, question->name, &dn);
> 	W_ERROR_NOT_OK_RETURN(werror);
>@@ -193,15 +194,66 @@ static WERROR handle_question(struct dns_server *dns,
> 	werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
> 	W_ERROR_NOT_OK_RETURN(werror);
> 
>-	ans = talloc_zero_array(mem_ctx, struct dns_res_rec, rec_count);
>+	ans_size = rec_count;
>+	ans = talloc_zero_array(mem_ctx, struct dns_res_rec, ans_size);
> 	W_ERROR_HAVE_NO_MEMORY(ans);
> 
> 	for (ri = 0; ri < rec_count; ri++) {
>+		bool need_cname_recursion = false;
>+
>+		/*
>+		 * As per kai through RFC. rfc1034
>+		 * If we ask for A(AAA) and the actual record is CNAME
>+		 * we return the CNAME + the A or AAAA record.
>+		 */
>+		if (recs[ri].wType == DNS_QTYPE_CNAME &&
>+		   (question->question_type == DNS_QTYPE_A || question->question_type == DNS_QTYPE_AAAA)) {
>+			need_cname_recursion = true;
>+		}
>+
> 		if ((question->question_type != DNS_QTYPE_ALL) &&
>+		    !need_cname_recursion &&
> 		    (recs[ri].wType != question->question_type)) {
> 			continue;
> 		}
>+
> 		werror = create_response_rr(question, &recs[ri], &ans, &ai);
>+
>+		if (need_cname_recursion) {
>+			/* This is not very elegant and we should be able to call ourselves for
>+			 * a recursive call, but it's working.
>+			 */
>+			struct dnsp_DnssrvRpcRecord *recs2;
>+			uint16_t rec_count2;
>+			unsigned int ri2;
>+			struct ldb_dn *dn2 = NULL;
>+			struct dns_name_question pseudoq;
>+
>+			memset(&pseudoq, 0, sizeof(struct dns_name_question));
>+			pseudoq.name = recs[ri].data.cname;
>+			werror = dns_name2dn(dns, mem_ctx, pseudoq.name, &dn2);
>+
>+			if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_RCODE_NAME_ERROR))
>+				continue;
>+			W_ERROR_NOT_OK_RETURN(werror);
>+
>+			werror = dns_lookup_records(dns, mem_ctx, dn2, &recs2, &rec_count2);
>+			W_ERROR_NOT_OK_RETURN(werror);
>+
>+			if (rec_count2 > 0) {
>+				ans_size += rec_count2;
>+				ans = talloc_realloc(mem_ctx, ans, struct dns_res_rec, ans_size);
>+				W_ERROR_HAVE_NO_MEMORY(ans);
>+
>+				for (ri2 = 0; ri2 < rec_count2; ri2++) {
>+					if (recs2[ri2].wType != ((enum dns_record_type)question->question_type)) {
>+						continue;
>+					}
>+					werror = create_response_rr(&pseudoq, &recs2[ri2], &ans, &ai);
>+				}
>+			}
>+		}
>+
> 		W_ERROR_NOT_OK_RETURN(werror);
> 	}
> 
>-- 
>1.7.5.4
>

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