resolv: Add test for getaddrinfo returning FQDN in ai_canonname

Test for BZ #15218.  This test verifies that getaddrinfo returns a
fully-qualified domain name in the ai_canonname field then
AI_CANONNAME is set and search domains apply.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

diff --git a/resolv/Makefile b/resolv/Makefile
index a49fac7f8a4405754683b5f3c7b34e55d3898e97..8fa3398d7618ae13bf48101a04981d4669588212 100644 (file)
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -140,6 +140,7 @@ tests += \
   tst-resolv-ai_idn-latin1 \
   tst-resolv-ai_idn-nolibidn2 \
   tst-resolv-canonname \
+  tst-resolv-getaddrinfo-fqdn \
   tst-resolv-trustad \
 
 # Needs resolv_context.
@@ -316,6 +317,7 @@ $(objpfx)tst-resolv-threads: $(objpfx)libresolv.so $(shared-thread-library)
 $(objpfx)tst-resolv-txnid-collision: $(objpfx)libresolv.a \
   $(static-thread-library)
 $(objpfx)tst-resolv-canonname: $(objpfx)libresolv.so $(shared-thread-library)
+$(objpfx)tst-resolv-getaddrinfo-fqdn: $(objpfx)libresolv.so $(shared-thread-library)
 $(objpfx)tst-resolv-trustad: $(objpfx)libresolv.so $(shared-thread-library)
 
 $(objpfx)tst-ns_name: $(objpfx)libresolv.so

diff --git a/resolv/tst-resolv-getaddrinfo-fqdn.c b/resolv/tst-resolv-getaddrinfo-fqdn.c
new file mode 100644 (file)
index 0000000..75bfe7e
--- /dev/null
+++ b/resolv/tst-resolv-getaddrinfo-fqdn.c
@@ -0,0 +1,147 @@
+/* Test for BZ #15218.  Verify that getaddrinfo returns FQDN in
+   ai_canonname, when AI_CANONNAME is requested and search domain apply.
+   Copyright (C) 2025 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <resolv.h>
+#include <stdlib.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/check_nss.h>
+#include <support/resolv_test.h>
+#include <support/support.h>
+
+static void
+response (const struct resolv_response_context *ctx,
+          struct resolv_response_builder *b,
+          const char *qname, uint16_t qclass, uint16_t qtype)
+{
+  if (strcmp (qname, "foo.site.example") == 0
+      || strcmp (qname, "bar.foo.site.example") == 0
+      || strcmp (qname, "site.example") == 0)
+    {
+      struct resolv_response_flags flags = { };
+      resolv_response_init (b, flags);
+      resolv_response_add_question (b, qname, qclass, qtype);
+      resolv_response_section (b, ns_s_an);
+      if (qtype == T_A)
+        {
+          char addr_ipv4[4] = { 127, 126, 125, 124 };
+          resolv_response_open_record (b, qname, qclass, T_A, 0x12345678);
+          resolv_response_add_data (b, addr_ipv4, sizeof (addr_ipv4));
+          resolv_response_close_record (b);
+        }
+      else if (qtype == T_AAAA)
+        {
+          char addr_ipv6[16] =
+            { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 };
+          resolv_response_open_record (b, qname, qclass, T_AAAA, 0x12345678);
+          resolv_response_add_data (b, addr_ipv6, sizeof (addr_ipv6));
+          resolv_response_close_record (b);
+        }
+      else
+        FAIL_EXIT1 ("qtype must be one of A, AAAA");
+    }
+  else
+    {
+      struct resolv_response_flags flags = {.rcode = ns_r_nxdomain, };
+      resolv_response_init (b, flags);
+      resolv_response_add_question (b, qname, qclass, qtype);
+    }
+}
+
+void
+query_host (const char *host_name, const char *expected_name)
+{
+  int family[] = { AF_INET, AF_INET6, AF_UNSPEC };
+  const char *family_names[] = { "AF_INET", "AF_INET6", "AF_UNSPEC" };
+
+  for (int i = 0; i < 3; i++)
+    {
+      struct addrinfo hints = {
+        .ai_socktype = 0,
+        .ai_protocol = 0,
+        .ai_family = family[i],
+        .ai_flags = AI_CANONNAME,
+      };
+      struct addrinfo *result, *current;
+      int res = getaddrinfo (host_name, NULL, &hints, &result);
+      if (res != 0)
+        FAIL_EXIT1 ("getaddrinfo (%s, %s): %s\n", host_name, family_names[i],
+                    gai_strerror (res));
+      else
+        {
+          int count = 0;
+          for (current = result;
+               current != NULL && current->ai_canonname != NULL;
+               current = current->ai_next)
+            {
+              TEST_COMPARE_STRING (current->ai_canonname, expected_name);
+              count++;
+            }
+          freeaddrinfo (result);
+          if (count > 1)
+            FAIL_EXIT1 ("Expected exactly one canonname, but got %d\n", count);
+        }
+    }
+}
+
+/* test with site.example domain.  */
+void
+test_search_with_site_example_domain (void)
+{
+  struct resolv_test *aux = resolv_test_start
+    ((struct resolv_redirect_config)
+     {
+       .response_callback = response,
+       .search = { "site.example" },
+     });
+
+  query_host ("foo", "foo.site.example");
+  query_host ("bar.foo", "bar.foo.site.example");
+
+  resolv_test_end (aux);
+}
+
+/* test with example domain.  */
+void
+test_search_with_example_domain (void)
+{
+  struct resolv_test *aux = resolv_test_start
+    ((struct resolv_redirect_config)
+     {
+       .response_callback = response,
+       .search = { "example" },
+     });
+
+  query_host ("foo.site", "foo.site.example");
+  query_host ("bar.foo.site", "bar.foo.site.example");
+  query_host ("site", "site.example");
+
+  resolv_test_end (aux);
+}
+
+static int
+do_test (void)
+{
+  test_search_with_site_example_domain ();
+  test_search_with_example_domain ();
+
+  return 0;
+}
+
+#include <support/test-driver.c>