net-dns/c-ares: backport RR sanity check fix

Signed-off-by: Sam James <sam@gentoo.org>

1 files changed, 166 insertions, 0 deletions

diff --git a/net-dns/c-ares/files/c-ares-1.25.0-fix-sanity-check-rr.patch b/net-dns/c-ares/files/c-ares-1.25.0-fix-sanity-check-rr.patch
new file mode 100644
index 000000000000..9b494ebfe8fe
--- /dev/null
+++ b/net-dns/c-ares/files/c-ares-1.25.0-fix-sanity-check-rr.patch
@@ -0,0 +1,166 @@
+https://github.com/c-ares/c-ares/issues/683
+https://github.com/c-ares/c-ares/commit/626dcb155b4daf3360e4251c64ce052e7e520b34
+
+From 626dcb155b4daf3360e4251c64ce052e7e520b34 Mon Sep 17 00:00:00 2001
+From: Brad House <brad@brad-house.com>
+Date: Fri, 12 Jan 2024 09:55:42 -0500
+Subject: [PATCH] Do not sanity check RR Name vs Question (#685)
+
+It appears as though we should never sanity check the RR name vs the question name as some DNS servers may return results for alias records.
+
+Fixes Bug: #683
+Fix By: Brad House (@bradh352)
+--- a/src/lib/ares__parse_into_addrinfo.c
++++ b/src/lib/ares__parse_into_addrinfo.c
+@@ -81,7 +81,6 @@ ares_status_t ares__parse_into_addrinfo(const unsigned char *abuf, size_t alen,
+   }
+ 
+   for (i = 0; i < ancount; i++) {
+-    const char          *rname = NULL;
+     ares_dns_rec_type_t  rtype;
+     const ares_dns_rr_t *rr =
+       ares_dns_record_rr_get(dnsrec, ARES_SECTION_ANSWER, i);
+@@ -91,13 +90,18 @@ ares_status_t ares__parse_into_addrinfo(const unsigned char *abuf, size_t alen,
+     }
+ 
+     rtype = ares_dns_rr_get_type(rr);
+-    rname = ares_dns_rr_get_name(rr);
+ 
+-    /* Old code did this hostname sanity check */
+-    if ((rtype == ARES_REC_TYPE_A || rtype == ARES_REC_TYPE_AAAA) &&
+-        strcasecmp(rname, hostname) != 0) {
+-      continue;
+-    }
++    /* Issue #683
++     * Old code did this hostname sanity check, however it appears this is
++     * flawed logic.  Other resolvers don't do this sanity check.  Leaving
++     * this code commented out for future reference.
++     *
++     * rname = ares_dns_rr_get_name(rr);
++     * if ((rtype == ARES_REC_TYPE_A || rtype == ARES_REC_TYPE_AAAA) &&
++     *     strcasecmp(rname, hostname) != 0) {
++     *   continue;
++     * }
++     */
+ 
+     if (rtype == ARES_REC_TYPE_CNAME) {
+       struct ares_addrinfo_cname *cname;
+--- a/src/lib/ares_parse_ptr_reply.c
++++ b/src/lib/ares_parse_ptr_reply.c
+@@ -113,7 +113,6 @@ int ares_parse_ptr_reply(const unsigned char *abuf, int alen_int,
+ 
+   /* Cycle through answers */
+   for (i = 0; i < ancount; i++) {
+-    const char          *rname = NULL;
+     const ares_dns_rr_t *rr =
+       ares_dns_record_rr_get(dnsrec, ARES_SECTION_ANSWER, i);
+ 
+@@ -141,17 +140,20 @@ int ares_parse_ptr_reply(const unsigned char *abuf, int alen_int,
+       continue;
+     }
+ 
+-    /* Old code compared the name in the rr to the ptrname, so we'll do that
+-     * check here, but I'm not sure its necessary */
+-    rname = ares_dns_rr_get_name(rr);
+-    if (rname == NULL) {
+-      /* Shouldn't be possible */
+-      status = ARES_EBADRESP;
+-      goto done;
+-    }
+-    if (strcasecmp(ptrname, rname) != 0) {
+-      continue;
+-    }
++    /* Issue #683
++     * Old code compared the name in the rr to the ptrname, but I think this
++     * is wrong since it was proven wrong for A & AAAA records.  Leaving
++     * this code commented out for future reference
++     *
++     * rname = ares_dns_rr_get_name(rr);
++     * if (rname == NULL) {
++     *   status = ARES_EBADRESP;
++     *   goto done;
++     * }
++     * if (strcasecmp(ptrname, rname) != 0) {
++     *   continue;
++     * }
++     */
+ 
+     /* Save most recent PTR record as the hostname */
+     hostname = ares_dns_rr_get_str(rr, ARES_RR_PTR_DNAME);
+--- a/test/ares-test-parse-a.cc
++++ b/test/ares-test-parse-a.cc
+@@ -312,13 +312,19 @@ TEST_F(LibraryTest, ParseAReplyErrors) {
+   EXPECT_EQ(nullptr, host);
+   pkt.add_question(new DNSQuestion("example.com", T_A));
+ 
+-  // Question != answer
++  // Question != answer, this is ok as of Issue #683
+   pkt.questions_.clear();
+   pkt.add_question(new DNSQuestion("Axample.com", T_A));
+   data = pkt.data();
+-  EXPECT_EQ(ARES_ENODATA, ares_parse_a_reply(data.data(), (int)data.size(),
++  EXPECT_EQ(ARES_SUCCESS, ares_parse_a_reply(data.data(), (int)data.size(),
+                                               &host, info, &count));
+-  EXPECT_EQ(nullptr, host);
++  ASSERT_NE(nullptr, host);
++  std::stringstream ss;
++  ss << HostEnt(host);
++  EXPECT_EQ("{'Axample.com' aliases=[] addrs=[2.3.4.5]}", ss.str());
++  ares_free_hostent(host);
++  host = nullptr;
++
+   pkt.questions_.clear();
+   pkt.add_question(new DNSQuestion("example.com", T_A));
+ 
+--- a/test/ares-test-parse-aaaa.cc
++++ b/test/ares-test-parse-aaaa.cc
+@@ -139,13 +139,19 @@ TEST_F(LibraryTest, ParseAaaaReplyErrors) {
+   EXPECT_EQ(nullptr, host);
+   pkt.add_question(new DNSQuestion("example.com", T_AAAA));
+ 
+-  // Question != answer
++  // Question != answer, this is ok as of Issue #683
+   pkt.questions_.clear();
+   pkt.add_question(new DNSQuestion("Axample.com", T_AAAA));
+   data = pkt.data();
+-  EXPECT_EQ(ARES_ENODATA, ares_parse_aaaa_reply(data.data(), (int)data.size(),
++  EXPECT_EQ(ARES_SUCCESS, ares_parse_aaaa_reply(data.data(), (int)data.size(),
+                                                 &host, info, &count));
+-  EXPECT_EQ(nullptr, host);
++  ASSERT_NE(nullptr, host);
++  std::stringstream ss;
++  ss << HostEnt(host);
++  EXPECT_EQ("{'Axample.com' aliases=[] addrs=[0101:0101:0202:0202:0303:0303:0404:0404]}", ss.str());
++  ares_free_hostent(host);
++
++  host = nullptr;
+   pkt.questions_.clear();
+   pkt.add_question(new DNSQuestion("example.com", T_AAAA));
+ 
+--- a/test/ares-test-parse-ptr.cc
++++ b/test/ares-test-parse-ptr.cc
+@@ -163,13 +163,20 @@ TEST_F(LibraryTest, ParsePtrReplyErrors) {
+                                                 addrv4, sizeof(addrv4), AF_INET, &host));
+   pkt.add_question(new DNSQuestion("64.48.32.16.in-addr.arpa", T_PTR));
+ 
+-  // Question != answer
++  // Question != answer, ok after #683
++  host = nullptr;
+   pkt.questions_.clear();
+   pkt.add_question(new DNSQuestion("99.48.32.16.in-addr.arpa", T_PTR));
+   data = pkt.data();
+-  EXPECT_EQ(ARES_ENODATA, ares_parse_ptr_reply(data.data(), (int)data.size(),
++  EXPECT_EQ(ARES_SUCCESS, ares_parse_ptr_reply(data.data(), (int)data.size(),
+                                                addrv4, sizeof(addrv4), AF_INET, &host));
+-  EXPECT_EQ(nullptr, host);
++  ASSERT_NE(nullptr, host);
++  std::stringstream ss;
++  ss << HostEnt(host);
++  EXPECT_EQ("{'other.com' aliases=[other.com] addrs=[16.32.48.64]}", ss.str());
++  ares_free_hostent(host);
++
++  host = nullptr;
+   pkt.questions_.clear();
+   pkt.add_question(new DNSQuestion("64.48.32.16.in-addr.arpa", T_PTR));
+ 
+