diff options
| -rw-r--r-- | resolv/Makefile | 2 | ||||
| -rw-r--r-- | resolv/tst-resolv-byaddr.c | 326 | ||||
| -rw-r--r-- | resolv/tst-resolv-maybe_insert_sig.h | 32 |
3 files changed, 360 insertions, 0 deletions
diff --git a/resolv/Makefile b/resolv/Makefile index 438672786f..b4132ffd04 100644 --- a/resolv/Makefile +++ b/resolv/Makefile @@ -90,6 +90,7 @@ tests += \ tst-res_hnok \ tst-resolv-basic \ tst-resolv-binary \ + tst-resolv-byaddr \ tst-resolv-edns \ tst-resolv-network \ tst-resolv-nondecimal \ @@ -258,6 +259,7 @@ $(objpfx)tst-resolv-ai_idn-nolibidn2.out: \ $(gen-locales) $(objpfx)tst-no-libidn2.so $(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) $(objpfx)tst-resolv-edns: $(objpfx)libresolv.so $(shared-thread-library) $(objpfx)tst-resolv-network: $(objpfx)libresolv.so $(shared-thread-library) $(objpfx)tst-resolv-res_init: $(objpfx)libresolv.so diff --git a/resolv/tst-resolv-byaddr.c b/resolv/tst-resolv-byaddr.c new file mode 100644 index 0000000000..6299e89837 --- /dev/null +++ b/resolv/tst-resolv-byaddr.c @@ -0,0 +1,326 @@ +/* Test reverse DNS lookup. + 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 <arpa/inet.h> +#include <errno.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/next_to_fault.h> +#include <support/resolv_test.h> +#include <support/support.h> + +#include "tst-resolv-maybe_insert_sig.h" + +/* QNAME format: + + ADDRESSES.CNAMES...(lots of 0s)...8.b.d.0.1.0.0.2.ip6.arpa. + CNAMES|ADDRESSES.2.0.192.in-addr-arpa. + + For the IPv4 reverse lookup, the address count is in the lower + bits. + + CNAMES is the length of the CNAME chain, ADDRESSES is the number of + addresses in the response. The special value 15 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); + TEST_COMPARE (qtype, T_PTR); + + unsigned int addresses, cnames, bits; + char *tail; + if (strstr (qname, "ip6.arpa") != NULL + && sscanf (qname, "%x.%x.%ms", &addresses, &cnames, &tail) == 3) + TEST_COMPARE_STRING (tail, "\ +0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa"); + else if (sscanf (qname, "%u.%ms", &bits, &tail) == 2) + { + TEST_COMPARE_STRING (tail, "2.0.192.in-addr.arpa"); + addresses = bits & 0x0f; + cnames = bits >> 4; + } + else + FAIL_EXIT1 ("invalid QNAME: %s", qname); + free (tail); + + int rcode; + if (addresses == 15) + { + /* 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, T_PTR, 60); + char *ptr = xasprintf ("unique-%d.cnames-%u.addresses-%u.example", + unique, cnames, addresses); + resolv_response_add_name (b, ptr); + free (ptr); + resolv_response_close_record (b); + } + + if (previous_name != qname) + free (previous_name); +} + +/* Used to check that gethostbyaddr_r does not write past the buffer + end. */ +static struct support_next_to_fault ntf; + +/* Perform a gethostbyaddr call and check the result. */ +static void +check_gethostbyaddr (const char *address, const char *expected) +{ + unsigned char bytes[16]; + unsigned int byteslen; + int family; + if (strchr (address, ':') != NULL) + { + family = AF_INET6; + byteslen = 16; + } + else + { + family = AF_INET; + byteslen = 4; + } + TEST_COMPARE (inet_pton (family, address, bytes), 1); + + struct hostent *e = gethostbyaddr (bytes, byteslen, family); + check_hostent (address, e, expected); + + if (e == NULL) + return; + + /* Try gethostbyaddr_r with increasing sizes until success. First + compute a reasonable minimum buffer size, to avoid many pointless + attempts. */ + size_t minimum_size = strlen (e->h_name); + for (int i = 0; e->h_addr_list[i] != NULL; ++i) + minimum_size += e->h_length + sizeof (char *); + for (int i = 0; e->h_aliases[i] != NULL; ++i) + minimum_size += strlen (e->h_aliases[i]) + 1 + sizeof (char *); + + /* Gradually increase the size until success. */ + for (size_t size = minimum_size; size < ntf.length; ++size) + { + struct hostent result; + int herrno; + int ret = gethostbyaddr_r (bytes, byteslen, family, &result, + ntf.buffer + ntf.length - size, size, + &e, &herrno); + if (ret == ERANGE) + /* Retry with larger size. */ + TEST_COMPARE (herrno, NETDB_INTERNAL); + else if (ret == 0) + { + TEST_VERIFY (size > minimum_size); + check_hostent (address, e, expected); + return; + } + else + FAIL_EXIT1 ("Unexpected gethostbyaddr_r failure: %d", ret); + } + + FAIL_EXIT1 ("gethostbyaddr_r always failed for: %s", address); +} + +/* Perform a getnameinfo call and check the result. */ +static void +check_getnameinfo (const char *address, const char *expected) +{ + struct sockaddr_in sin = { }; + struct sockaddr_in6 sin6 = { }; + void *sa; + socklen_t salen; + if (strchr (address, ':') != NULL) + { + sin6.sin6_family = AF_INET6; + TEST_COMPARE (inet_pton (AF_INET6, address, &sin6.sin6_addr), 1); + sin6.sin6_port = htons (80); + sa = &sin6; + salen = sizeof (sin6); + } + else + { + sin.sin_family = AF_INET; + TEST_COMPARE (inet_pton (AF_INET, address, &sin.sin_addr), 1); + sin.sin_port = htons (80); + sa = &sin; + salen = sizeof (sin); + } + + char host[64]; + char service[64]; + int ret = getnameinfo (sa, salen, host, + sizeof (host), service, sizeof (service), + NI_NAMEREQD | NI_NUMERICSERV); + switch (ret) + { + case 0: + TEST_COMPARE_STRING (host, expected); + TEST_COMPARE_STRING (service, "80"); + break; + case EAI_SYSTEM: + TEST_COMPARE_STRING (strerror (errno), expected); + break; + default: + TEST_COMPARE_STRING (gai_strerror (ret), expected); + } +} + +static int +do_test (void) +{ + /* Some reasonably upper bound for the maximum response size. */ + ntf = support_next_to_fault_allocate (4096); + + struct resolv_test *obj = resolv_test_start + ((struct resolv_redirect_config) + { + .response_callback = response + }); + + for (int do_insert_sig = 0; do_insert_sig < 2; ++do_insert_sig) + { + insert_sig = do_insert_sig; + + /* No PTR record, RCODE=0. */ + check_gethostbyaddr ("192.0.2.0", "error: NO_RECOVERY\n"); + check_getnameinfo ("192.0.2.0", "Name or service not known"); + check_gethostbyaddr ("192.0.2.16", "error: NO_RECOVERY\n"); + check_getnameinfo ("192.0.2.16", "Name or service not known"); + check_gethostbyaddr ("192.0.2.32", "error: NO_RECOVERY\n"); + check_getnameinfo ("192.0.2.32", "Name or service not known"); + check_gethostbyaddr ("2001:db8::", "error: NO_RECOVERY\n"); + check_getnameinfo ("2001:db8::", "Name or service not known"); + check_gethostbyaddr ("2001:db8::10", "error: NO_RECOVERY\n"); + check_getnameinfo ("2001:db8::10", "Name or service not known"); + check_gethostbyaddr ("2001:db8::20", "error: NO_RECOVERY\n"); + check_getnameinfo ("2001:db8::20", "Name or service not known"); + + /* No PTR record, NXDOMAIN. */ + check_gethostbyaddr ("192.0.2.15", "error: HOST_NOT_FOUND\n"); + check_getnameinfo ("192.0.2.15", "Name or service not known"); + check_gethostbyaddr ("192.0.2.31", "error: HOST_NOT_FOUND\n"); + check_getnameinfo ("192.0.2.31", "Name or service not known"); + check_gethostbyaddr ("192.0.2.47", "error: HOST_NOT_FOUND\n"); + check_getnameinfo ("192.0.2.47", "Name or service not known"); + check_gethostbyaddr ("2001:db8::f", "error: HOST_NOT_FOUND\n"); + check_getnameinfo ("2001:db8::f", "Name or service not known"); + check_gethostbyaddr ("2001:db8::1f", "error: HOST_NOT_FOUND\n"); + check_getnameinfo ("2001:db8::1f", "Name or service not known"); + check_gethostbyaddr ("2001:db8::2f", "error: HOST_NOT_FOUND\n"); + check_getnameinfo ("2001:db8::2f", "Name or service not known"); + + /* Actual response data. Only the first PTR record is returned. */ + check_gethostbyaddr ("192.0.2.1", + "name: unique-0.cnames-0.addresses-1.example\n" + "address: 192.0.2.1\n"); + check_getnameinfo ("192.0.2.1", + "unique-0.cnames-0.addresses-1.example"); + check_gethostbyaddr ("192.0.2.17", + "name: unique-0.cnames-1.addresses-1.example\n" + "address: 192.0.2.17\n"); + check_getnameinfo ("192.0.2.17", + "unique-0.cnames-1.addresses-1.example"); + check_gethostbyaddr ("192.0.2.18", + "name: unique-0.cnames-1.addresses-2.example\n" + "address: 192.0.2.18\n"); + check_getnameinfo ("192.0.2.18", + "unique-0.cnames-1.addresses-2.example"); + check_gethostbyaddr ("192.0.2.33", + "name: unique-0.cnames-2.addresses-1.example\n" + "address: 192.0.2.33\n"); + check_getnameinfo ("192.0.2.33", + "unique-0.cnames-2.addresses-1.example"); + check_gethostbyaddr ("192.0.2.34", + "name: unique-0.cnames-2.addresses-2.example\n" + "address: 192.0.2.34\n"); + check_getnameinfo ("192.0.2.34", + "unique-0.cnames-2.addresses-2.example"); + + /* Same for IPv6 addresses. */ + check_gethostbyaddr ("2001:db8::1", + "name: unique-0.cnames-0.addresses-1.example\n" + "address: 2001:db8::1\n"); + check_getnameinfo ("2001:db8::1", + "unique-0.cnames-0.addresses-1.example"); + check_gethostbyaddr ("2001:db8::11", + "name: unique-0.cnames-1.addresses-1.example\n" + "address: 2001:db8::11\n"); + check_getnameinfo ("2001:db8::11", + "unique-0.cnames-1.addresses-1.example"); + check_gethostbyaddr ("2001:db8::12", + "name: unique-0.cnames-1.addresses-2.example\n" + "address: 2001:db8::12\n"); + check_getnameinfo ("2001:db8::12", + "unique-0.cnames-1.addresses-2.example"); + check_gethostbyaddr ("2001:db8::21", + "name: unique-0.cnames-2.addresses-1.example\n" + "address: 2001:db8::21\n"); + check_getnameinfo ("2001:db8::21", + "unique-0.cnames-2.addresses-1.example"); + check_gethostbyaddr ("2001:db8::22", + "name: unique-0.cnames-2.addresses-2.example\n" + "address: 2001:db8::22\n"); + check_getnameinfo ("2001:db8::22", + "unique-0.cnames-2.addresses-2.example"); + } + + resolv_test_end (obj); + + support_next_to_fault_free (&ntf); + return 0; +} + +#include <support/test-driver.c> diff --git a/resolv/tst-resolv-maybe_insert_sig.h b/resolv/tst-resolv-maybe_insert_sig.h new file mode 100644 index 0000000000..05725225af --- /dev/null +++ b/resolv/tst-resolv-maybe_insert_sig.h @@ -0,0 +1,32 @@ +/* Code snippet for optionally inserting ignored SIG records in resolver tests. + 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/>. */ + +/* Set to true for an alternative pass that inserts (ignored) SIG + records. This does not alter the response, so this property is not + encoded in the QNAME. The variable needs to be volatile because + leaf attributes tell GCC that the response function is not + called. */ +static volatile bool insert_sig; + +static void +maybe_insert_sig (struct resolv_response_builder *b, const char *owner) +{ + resolv_response_open_record (b, owner, C_IN, T_SIG, 60); + resolv_response_add_data (b, "", 1); + resolv_response_close_record (b); +} |