From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH v2 02/13] resolv: Add tst-resolv-aliases
Date: Fri, 26 Aug 2022 12:33:23 +0200 [thread overview]
Message-ID: <54b9a79f91655996cfe4f21b4e9206d7138247f3.1661509943.git.fweimer@redhat.com> (raw)
In-Reply-To: <cover.1661509943.git.fweimer@redhat.com>
---
resolv/Makefile | 2 +
resolv/tst-resolv-aliases.c | 254 ++++++++++++++++++++++++++++++++++++
2 files changed, 256 insertions(+)
create mode 100644 resolv/tst-resolv-aliases.c
diff --git a/resolv/Makefile b/resolv/Makefile
index 98b10d97a0..0038bb7028 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -89,6 +89,7 @@ tests += \
tst-ns_name_pton \
tst-res_hconf_reorder \
tst-res_hnok \
+ tst-resolv-aliases \
tst-resolv-basic \
tst-resolv-binary \
tst-resolv-byaddr \
@@ -259,6 +260,7 @@ $(objpfx)tst-resolv-ai_idn.out: $(gen-locales)
$(objpfx)tst-resolv-ai_idn-latin1.out: $(gen-locales)
$(objpfx)tst-resolv-ai_idn-nolibidn2.out: \
$(gen-locales) $(objpfx)tst-no-libidn2.so
+$(objpfx)tst-resolv-aliases: $(objpfx)libresolv.so $(shared-thread-library)
$(objpfx)tst-resolv-basic: $(objpfx)libresolv.so $(shared-thread-library)
$(objpfx)tst-resolv-binary: $(objpfx)libresolv.so $(shared-thread-library)
$(objpfx)tst-resolv-byaddr: $(objpfx)libresolv.so $(shared-thread-library)
diff --git a/resolv/tst-resolv-aliases.c b/resolv/tst-resolv-aliases.c
new file mode 100644
index 0000000000..b212823aa0
--- /dev/null
+++ b/resolv/tst-resolv-aliases.c
@@ -0,0 +1,254 @@
+/* Test alias handling (mainly for gethostbyname).
+ Copyright (C) 2022 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 <array_length.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <stdbool.h>
+#include <stdio.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>
+
+#include "tst-resolv-maybe_insert_sig.h"
+
+/* QNAME format:
+
+ aADDRESSES-cCNAMES.example.net
+
+ CNAMES is the length of the CNAME chain, ADDRESSES is the number of
+ addresses in the response. The special value 255 means that there
+ are no addresses, and the RCODE is NXDOMAIN. */
+static void
+response (const struct resolv_response_context *ctx,
+ struct resolv_response_builder *b,
+ const char *qname, uint16_t qclass, uint16_t qtype)
+{
+ TEST_COMPARE (qclass, C_IN);
+ if (qtype != T_A)
+ TEST_COMPARE (qtype, T_AAAA);
+
+ unsigned int addresses, cnames;
+ char *tail;
+ if (sscanf (qname, "a%u-c%u%ms", &addresses, &cnames, &tail) == 3)
+ {
+ if (strcmp (tail, ".example.com") == 0
+ || strcmp (tail, ".example.net.example.net") == 0
+ || strcmp (tail, ".example.net.example.com") == 0)
+ /* These only happen after NXDOMAIN. */
+ TEST_VERIFY (addresses == 255);
+ else if (strcmp (tail, ".example.net") != 0)
+ FAIL_EXIT1 ("invalid QNAME: %s", qname);
+ }
+ free (tail);
+
+ int rcode;
+ if (addresses == 255)
+ {
+ /* Special case: Use no addresses with NXDOMAIN response. */
+ rcode = ns_r_nxdomain;
+ addresses = 0;
+ }
+ else
+ rcode = 0;
+
+ struct resolv_response_flags flags = { .rcode = rcode };
+ resolv_response_init (b, flags);
+ resolv_response_add_question (b, qname, qclass, qtype);
+ resolv_response_section (b, ns_s_an);
+ maybe_insert_sig (b, qname);
+
+ /* Provide the requested number of CNAME records. */
+ char *previous_name = (char *) qname;
+ for (int unique = 0; unique < cnames; ++unique)
+ {
+ resolv_response_open_record (b, previous_name, qclass, T_CNAME, 60);
+ char *new_name = xasprintf ("%d.alias.example", unique);
+ resolv_response_add_name (b, new_name);
+ resolv_response_close_record (b);
+
+ maybe_insert_sig (b, qname);
+
+ if (previous_name != qname)
+ free (previous_name);
+ previous_name = new_name;
+ }
+
+ for (int unique = 0; unique < addresses; ++unique)
+ {
+ resolv_response_open_record (b, previous_name, qclass, qtype, 60);
+
+ if (qtype == T_A)
+ {
+ char ipv4[4] = {192, 0, 2, 1 + unique};
+ resolv_response_add_data (b, &ipv4, sizeof (ipv4));
+ }
+ else if (qtype == T_AAAA)
+ {
+ char ipv6[16] =
+ {
+ 0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 1 + unique
+ };
+ resolv_response_add_data (b, &ipv6, sizeof (ipv6));
+ }
+ resolv_response_close_record (b);
+ }
+
+ if (previous_name != qname)
+ free (previous_name);
+}
+
+static char *
+make_qname (bool do_search, int cnames, int addresses)
+{
+ return xasprintf ("a%d-c%d%s",
+ addresses, cnames, do_search ? "" : ".example.net");
+}
+
+static void
+check_cnames_failure (int af, bool do_search, int cnames, int addresses)
+{
+ char *qname = make_qname (do_search, cnames, addresses);
+
+ struct hostent *e;
+ if (af == AF_UNSPEC)
+ e = gethostbyname (qname);
+ else
+ e = gethostbyname2 (qname, af);
+
+ if (addresses == 0)
+ check_hostent (qname, e, "error: NO_RECOVERY\n");
+ else
+ check_hostent (qname, e, "error: HOST_NOT_FOUND\n");
+
+ free (qname);
+}
+
+static void
+check (int af, bool do_search, int cnames, int addresses)
+{
+ char *qname = make_qname (do_search, cnames, addresses);
+ char *fqdn = make_qname (false, cnames, addresses);
+
+ struct hostent *e;
+ if (af == AF_UNSPEC)
+ e = gethostbyname (qname);
+ else
+ e = gethostbyname2 (qname, af);
+ if (e == NULL)
+ FAIL_EXIT1 ("unexpected failure for %d, %d, %d", af, cnames, addresses);
+
+ if (af == AF_UNSPEC || af == AF_INET)
+ {
+ TEST_COMPARE (e->h_addrtype, AF_INET);
+ TEST_COMPARE (e->h_length, 4);
+ }
+ else
+ {
+ TEST_COMPARE (e->h_addrtype, AF_INET6);
+ TEST_COMPARE (e->h_length, 16);
+ }
+
+ for (int i = 0; i < addresses; ++i)
+ {
+ char ipv4[4] = {192, 0, 2, 1 + i};
+ char ipv6[16] =
+ { 0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 + i };
+ char *expected = e->h_addrtype == AF_INET ? ipv4 : ipv6;
+ TEST_COMPARE_BLOB (e->h_addr_list[i], e->h_length,
+ expected, e->h_length);
+ }
+ TEST_VERIFY (e->h_addr_list[addresses] == NULL);
+
+
+ if (cnames == 0)
+ {
+ /* QNAME is fully qualified. */
+ TEST_COMPARE_STRING (e->h_name, fqdn);
+ TEST_VERIFY (e->h_aliases[0] == NULL);
+ }
+ else
+ {
+ /* Fully-qualified QNAME is demoted to an aliases. */
+ TEST_COMPARE_STRING (e->h_aliases[0], fqdn);
+
+ for (int i = 1; i <= cnames; ++i)
+ {
+ char *expected = xasprintf ("%d.alias.example", i - 1);
+ if (i == cnames)
+ TEST_COMPARE_STRING (e->h_name, expected);
+ else
+ TEST_COMPARE_STRING (e->h_aliases[i], expected);
+ free (expected);
+ }
+ TEST_VERIFY (e->h_aliases[cnames] == NULL);
+ }
+
+ free (fqdn);
+ free (qname);
+}
+
+static int
+do_test (void)
+{
+ struct resolv_test *obj = resolv_test_start
+ ((struct resolv_redirect_config)
+ {
+ .response_callback = response,
+ .search = { "example.net", "example.com" },
+ });
+
+ static const int families[] = { AF_UNSPEC, AF_INET, AF_INET6 };
+
+ for (int do_insert_sig = 0; do_insert_sig < 2; ++do_insert_sig)
+ {
+ insert_sig = do_insert_sig;
+
+ /* If do_search is true, a bare host name (for example, a1-c1)
+ is used. This exercises search path processing and FQDN
+ qualification. */
+ for (int do_search = 0; do_search < 2; ++do_search)
+ for (const int *paf = families; paf != array_end (families); ++paf)
+ {
+ for (int cnames = 0; cnames <= 100; ++cnames)
+ {
+ check_cnames_failure (*paf, do_search, cnames, 0);
+ /* Now with NXDOMAIN responses. */
+ check_cnames_failure (*paf, do_search, cnames, 255);
+ }
+
+ for (int cnames = 0; cnames <= 10; ++cnames)
+ for (int addresses = 1; addresses <= 10; ++addresses)
+ check (*paf, do_search, cnames, addresses);
+
+ /* The current implementation is limited to 47 aliases.
+ Addresses do not have such a limit. */
+ check (*paf, do_search, 47, 60);
+ }
+ }
+
+ resolv_test_end (obj);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
--
2.37.1
next prev parent reply other threads:[~2022-08-26 10:33 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-26 10:33 [PATCH v2 00/13] nss_dns: Fix handling of non-host CNAMEs (bug 12154) Florian Weimer
2022-08-26 10:33 ` [PATCH v2 01/13] resolv: Add tst-resolv-byaddr for testing reverse lookup Florian Weimer
2022-08-29 19:56 ` Siddhesh Poyarekar
2022-08-26 10:33 ` Florian Weimer [this message]
2022-08-29 19:57 ` [PATCH v2 02/13] resolv: Add tst-resolv-aliases Siddhesh Poyarekar
2022-08-26 10:33 ` [PATCH v2 03/13] resolv: Add internal __res_binary_hnok function Florian Weimer
2022-08-26 10:33 ` [PATCH v2 04/13] resolv: Add the __ns_samebinaryname function Florian Weimer
2022-08-26 10:33 ` [PATCH v2 05/13] resolv: Add internal __ns_name_length_uncompressed function Florian Weimer
2022-08-26 10:33 ` [PATCH v2 06/13] resolv: Add DNS packet parsing helpers geared towards wire format Florian Weimer
2022-08-26 10:33 ` [PATCH v2 07/13] nss_dns: Split getanswer_ptr from getanswer_r Florian Weimer
2022-08-26 10:33 ` [PATCH v2 08/13] nss_dns: Rewrite _nss_dns_gethostbyaddr2_r and getanswer_ptr Florian Weimer
2022-08-26 10:33 ` [PATCH v2 09/13] nss_dns: Remove remnants of IPv6 address mapping Florian Weimer
2022-08-26 10:34 ` [PATCH v2 10/13] nss_dns: Rewrite getanswer_r to match getanswer_ptr (bug 12154, bug 29305) Florian Weimer
2022-08-26 10:34 ` [PATCH v2 11/13] nss_dns: In gaih_getanswer_slice, skip strange aliases (bug 12154) Florian Weimer
2022-08-26 10:34 ` [PATCH v2 12/13] resolv: Add new tst-resolv-invalid-cname Florian Weimer
2022-08-30 10:59 ` Szabolcs Nagy
2022-08-30 11:13 ` Florian Weimer
2022-08-26 10:34 ` [PATCH v2 13/13] nss_dns: Rewrite _nss_dns_gethostbyname4_r using current interfaces Florian Weimer
2022-08-29 20:01 ` Siddhesh Poyarekar
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