diff options
Diffstat (limited to 'resolv/tst-resolv-invalid-cname.c')
| -rw-r--r-- | resolv/tst-resolv-invalid-cname.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/resolv/tst-resolv-invalid-cname.c b/resolv/tst-resolv-invalid-cname.c new file mode 100644 index 0000000000..ae2d4419b1 --- /dev/null +++ b/resolv/tst-resolv-invalid-cname.c @@ -0,0 +1,406 @@ +/* Test handling of CNAMEs with non-host domain names (bug 12154). + 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 <errno.h> +#include <netdb.h> +#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> +#include <support/xmemstream.h> + +/* Query strings describe the CNAME chain in the response. They have + the format "bitsBITS.countCOUNT.example.", where BITS and COUNT are + replaced by unsigned decimal numbers. COUNT is the number of CNAME + records in the response. BITS has two bits for each CNAME record, + describing a special prefix that is added to that CNAME. + + 0: No special leading label. + 1: Starting with "*.". + 2: Starting with "-x.". + 3: Starting with "star.*.". + + The first CNAME in the response using the two least significant + bits. + + For PTR queries, the QNAME format is different, it is either + COUNT.BITS.168.192.in-addr.arpa. (with BITS and COUNT still + decimal), or: + +COUNT.BITS0.BITS1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa. + + where BITS and COUNT are hexadecimal. */ + +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); + + /* The only other query type besides A is PTR. */ + if (qtype != T_A && qtype != T_AAAA) + TEST_COMPARE (qtype, T_PTR); + + unsigned int bits, bits1, count; + char *tail = NULL; + if (sscanf (qname, "bits%u.count%u.%ms", &bits, &count, &tail) == 3) + TEST_COMPARE_STRING (tail, "example"); + else if (strstr (qname, "in-addr.arpa") != NULL + && sscanf (qname, "%u.%u.%ms", &bits, &count, &tail) == 3) + TEST_COMPARE_STRING (tail, "168.192.in-addr.arpa"); + else if (sscanf (qname, "%x.%x.%x.%ms", &bits, &bits1, &count, &tail) == 4) + { + TEST_COMPARE_STRING (tail, "\ +0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa"); + bits |= bits1 << 4; + } + else + FAIL_EXIT1 ("invalid QNAME: %s\n", qname); + free (tail); + + 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); + + /* Provide the requested number of CNAME records. */ + char *previous_name = (char *) qname; + unsigned int original_bits = bits; + for (int unique = 0; unique < count; ++unique) + { + resolv_response_open_record (b, previous_name, qclass, T_CNAME, 60); + + static const char bits_to_prefix[4][8] = { "", "*.", "-x.", "star.*." }; + char *new_name = xasprintf ("%sunique%d.example", + bits_to_prefix[bits & 3], unique); + bits >>= 2; + resolv_response_add_name (b, new_name); + resolv_response_close_record (b); + + if (previous_name != qname) + free (previous_name); + previous_name = new_name; + } + + /* Actual answer record. */ + resolv_response_open_record (b, previous_name, qclass, qtype, 60); + switch (qtype) + { + case T_A: + { + char ipv4[4] = {192, 168, count, original_bits}; + resolv_response_add_data (b, &ipv4, sizeof (ipv4)); + } + break; + case T_AAAA: + { + char ipv6[16] = + { + 0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + count, original_bits + }; + resolv_response_add_data (b, &ipv6, sizeof (ipv6)); + } + break; + + case T_PTR: + { + char *name = xasprintf ("bits%u.count%u.example", + original_bits, count); + resolv_response_add_name (b, name); + free (name); + } + break; + } + resolv_response_close_record (b); + + if (previous_name != qname) + free (previous_name); +} + +/* Controls which name resolution function is invoked. */ +enum test_mode + { + byname, /* gethostbyname. */ + byname2, /* gethostbyname2. */ + gai, /* getaddrinfo without AI_CANONNAME. */ + gai_canon, /* getaddrinfo with AI_CANONNAME. */ + + test_mode_num /* Number of enum values. */ + }; + +static const char * +test_mode_to_string (enum test_mode mode) +{ + switch (mode) + { + case byname: + return "byname"; + case byname2: + return "byname2"; + case gai: + return "gai"; + case gai_canon: + return "gai_canon"; + case test_mode_num: + /* Report error below. */ + } + FAIL_EXIT1 ("invalid test_mode: %d", mode); +} + +/* Append the name and aliases to OUT. */ +static void +append_names (FILE *out, const char *qname, int bits, int count, + enum test_mode mode) +{ + /* Largest valid index which has a corresponding zero in bits + (meaning a syntactically valid CNAME). */ + int last_valid_cname = -1; + + for (int i = 0; i < count; ++i) + if ((bits & (3 << (i * 2))) == 0) + last_valid_cname = i; + + if (mode != gai) + { + const char *label; + if (mode == gai_canon) + label = "canonname"; + else + label = "name"; + if (last_valid_cname >= 0) + fprintf (out, "%s: unique%d.example\n", label, last_valid_cname); + else + fprintf (out, "%s: %s\n", label, qname); + } + + if (mode == byname || mode == byname2) + { + if (last_valid_cname >= 0) + fprintf (out, "alias: %s\n", qname); + for (int i = 0; i < count; ++i) + { + if ((bits & (3 << (i * 2))) == 0 && i != last_valid_cname) + fprintf (out, "alias: unique%d.example\n", i); + } + } +} + +/* Append the address information to OUT. */ +static void +append_addresses (FILE *out, int af, int bits, int count, enum test_mode mode) +{ + int last = count * 256 + bits; + if (mode == gai || mode == gai_canon) + { + if (af == AF_INET || af == AF_UNSPEC) + fprintf (out, "address: STREAM/TCP 192.168.%d.%d 80\n", count, bits); + if (af == AF_INET6 || af == AF_UNSPEC) + { + if (last == 0) + fprintf (out, "address: STREAM/TCP 2001:db8:: 80\n"); + else + fprintf (out, "address: STREAM/TCP 2001:db8::%x 80\n", last); + } + } + else + { + TEST_VERIFY (af != AF_UNSPEC); + if (af == AF_INET) + fprintf (out, "address: 192.168.%d.%d\n", count, bits); + if (af == AF_INET6) + { + if (last == 0) + fprintf (out, "address: 2001:db8::\n"); + else + fprintf (out, "address: 2001:db8::%x\n", last); + } + } +} + +/* Perform one test using a forward lookup. */ +static void +check_forward (int af, int bits, int count, enum test_mode mode) +{ + char *qname = xasprintf ("bits%d.count%d.example", bits, count); + char *label = xasprintf ("af=%d bits=%d count=%d mode=%s qname=%s", + af, bits, count, test_mode_to_string (mode), qname); + + struct xmemstream expected; + xopen_memstream (&expected); + if (mode == gai_canon) + fprintf (expected.out, "flags: AI_CANONNAME\n"); + append_names (expected.out, qname, bits, count, mode); + append_addresses (expected.out, af, bits, count, mode); + xfclose_memstream (&expected); + + if (mode == gai || mode == gai_canon) + { + struct addrinfo *ai; + struct addrinfo hints = + { + .ai_family = af, + .ai_socktype = SOCK_STREAM, + }; + if (mode == gai_canon) + hints.ai_flags |= AI_CANONNAME; + int ret = getaddrinfo (qname, "80", &hints, &ai); + check_addrinfo (label, ai, ret, expected.buffer); + if (ret == 0) + freeaddrinfo (ai); + } + else + { + struct hostent *e; + if (mode == gai) + { + TEST_COMPARE (af, AF_INET); + e = gethostbyname (qname); + } + else + { + if (af != AF_INET) + TEST_COMPARE (af, AF_INET6); + e = gethostbyname2 (qname, af); + } + check_hostent (label, e, expected.buffer); + } + + free (expected.buffer); + free (label); + free (qname); +} + +/* Perform one check using a reverse lookup. */ + +static void +check_reverse (int af, int bits, int count) +{ + TEST_VERIFY (af == AF_INET || af == AF_INET6); + + char *label = xasprintf ("af=%d bits=%d count=%d", af, bits, count); + char *fqdn = xasprintf ("bits%d.count%d.example", bits, count); + + struct xmemstream expected; + xopen_memstream (&expected); + fprintf (expected.out, "name: %s\n", fqdn); + append_addresses (expected.out, af, bits, count, byname); + xfclose_memstream (&expected); + + char addr[16] = { 0 }; + socklen_t addrlen; + if (af == AF_INET) + { + addr[0] = 192; + addr[1] = 168; + addr[2] = count; + addr[3] = bits; + addrlen = 4; + } + else + { + addr[0] = 0x20; + addr[1] = 0x01; + addr[2] = 0x0d; + addr[3] = 0xb8; + addr[14] = count; + addr[15] = bits; + addrlen = 16; + } + + struct hostent *e = gethostbyaddr (addr, addrlen, af); + check_hostent (label, e, expected.buffer); + + /* getnameinfo check is different. There is no generic check_* + function for it. */ + { + struct sockaddr_in sin = { }; + struct sockaddr_in6 sin6 = { }; + void *sa; + socklen_t salen; + if (af == AF_INET) + { + sin.sin_family = AF_INET; + memcpy (&sin.sin_addr, addr, addrlen); + sin.sin_port = htons (80); + sa = &sin; + salen = sizeof (sin); + } + else + { + sin6.sin6_family = AF_INET6; + memcpy (&sin6.sin6_addr, addr, addrlen); + sin6.sin6_port = htons (80); + sa = &sin6; + salen = sizeof (sin6); + } + + char host[64]; + char service[64]; + int ret = getnameinfo (sa, salen, host, + sizeof (host), service, sizeof (service), + NI_NAMEREQD | NI_NUMERICSERV); + TEST_COMPARE (ret, 0); + TEST_COMPARE_STRING (host, fqdn); + TEST_COMPARE_STRING (service, "80"); + } + + free (expected.buffer); + free (fqdn); + free (label); +} + +static int +do_test (void) +{ + struct resolv_test *obj = resolv_test_start + ((struct resolv_redirect_config) + { + .response_callback = response + }); + + for (int count = 0; count <= 3; ++count) + for (int bits = 0; bits <= 1 << (count * 2); ++bits) + { + if (count > 0 && bits == count) + /* The last bits value is only checked if count == 0. */ + continue; + + for (enum test_mode mode = 0; mode < test_mode_num; ++mode) + { + check_forward (AF_INET, bits, count, mode); + if (mode != byname) + check_forward (AF_INET6, bits, count, mode); + if (mode == gai || mode == gai_canon) + check_forward (AF_UNSPEC, bits, count, mode); + } + + check_reverse (AF_INET, bits, count); + check_reverse (AF_INET6, bits, count); + } + + resolv_test_end (obj); + + return 0; +} + +#include <support/test-driver.c> |