diff options
| -rw-r--r-- | resolv/Makefile | 2 | ||||
| -rw-r--r-- | resolv/tst-resolv-aliases.c | 254 |
2 files changed, 256 insertions, 0 deletions
diff --git a/resolv/Makefile b/resolv/Makefile index 98b10d9..0038bb7 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 0000000..b212823 --- /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> |