/* Test search/default domain name behavior. Copyright (C) 2016-2024 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 . */ #include #include #include #include #include #include #include #include struct item { const char *name; int response; }; const struct item items[] = { {"hostname.usersys.example.com", 1}, {"hostname.corp.example.com", 1}, {"hostname.example.com", 1}, {"mail.corp.example.com", 1}, {"mail.example.com", 1}, {"file.corp.example.com", 2}, {"file.corp", 1}, {"file.example.com", 1}, {"servfail-usersys.usersys.example.com", -ns_r_servfail}, {"servfail-usersys.corp.example.com", 1}, {"servfail-usersys.example.com", 1}, {"servfail-corp.usersys.example.com", 1}, {"servfail-corp.corp.example.com", -ns_r_servfail}, {"servfail-corp.example.com", 1}, {"www.example.com", 1}, {"large.example.com", 200}, /* Test query amplification with a SERVFAIL response combined with a large RRset. */ {"large-servfail.usersys.example.com", -ns_r_servfail}, {"large-servfail.example.com", 2000}, {} }; enum { name_not_found = -1, name_no_data = -2 }; static int find_name (const char *name) { for (int i = 0; items[i].name != NULL; ++i) { if (strcmp (name, items[i].name) == 0) return i; } if (strcmp (name, "example.com") == 0 || strcmp (name, "usersys.example.com") == 0 || strcmp (name, "corp.example.com") == 0) return name_no_data; return name_not_found; } static int rcode_override_server_index = -1; static int rcode_override; static void response (const struct resolv_response_context *ctx, struct resolv_response_builder *b, const char *qname, uint16_t qclass, uint16_t qtype) { if (ctx->server_index == rcode_override_server_index) { struct resolv_response_flags flags = {.rcode = rcode_override}; resolv_response_init (b, flags); resolv_response_add_question (b, qname, qclass, qtype); return; } int index = find_name (qname); struct resolv_response_flags flags = {}; if (index == name_not_found) flags.rcode = ns_r_nxdomain; else if (index >= 0 && items[index].response < 0) flags.rcode = -items[index].response; else if (index >= 0 && items[index].response > 5 && !ctx->tcp) /* Force TCP if more than 5 addresses where requested. */ flags.tc = true; resolv_response_init (b, flags); resolv_response_add_question (b, qname, qclass, qtype); if (flags.tc || index < 0 || items[index].response < 0) return; resolv_response_section (b, ns_s_an); for (int i = 0; i < items[index].response; ++i) { resolv_response_open_record (b, qname, qclass, qtype, 0); switch (qtype) { case T_A: { char addr[4] = {10, index, i >> 8, i}; resolv_response_add_data (b, addr, sizeof (addr)); } break; case T_AAAA: { char addr[16] = {0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, index + 1, (i + 1) >> 8, i + 1}; resolv_response_add_data (b, addr, sizeof (addr)); } break; default: support_record_failure (); printf ("error: unexpected QTYPE: %s/%u/%u\n", qname, qclass, qtype); } resolv_response_close_record (b); } } enum output_format { format_get, format_gai }; static void format_expected_1 (FILE *out, int family, enum output_format format, int index) { for (int i = 0; i < items[index].response; ++i) { char address[200]; switch (family) { case AF_INET: snprintf (address, sizeof (address), "10.%d.%d.%d", index, (i >> 8) & 0xff, i & 0xff); break; case AF_INET6: snprintf (address, sizeof (address), "2001:db8::%x:%x", index + 1, i + 1); break; default: FAIL_EXIT1 ("unreachable"); } switch (format) { case format_get: fprintf (out, "address: %s\n", address); break; case format_gai: fprintf (out, "address: STREAM/TCP %s 80\n", address); } } } static char * format_expected (const char *fqdn, int family, enum output_format format) { int index = find_name (fqdn); TEST_VERIFY_EXIT (index >= 0); struct xmemstream stream; xopen_memstream (&stream); TEST_VERIFY_EXIT (items[index].response >= 0); if (format == format_get) fprintf (stream.out, "name: %s\n", items[index].name); if (family == AF_INET || family == AF_UNSPEC) format_expected_1 (stream.out, AF_INET, format, index); if (family == AF_INET6 || family == AF_UNSPEC) format_expected_1 (stream.out, AF_INET6, format, index); xfclose_memstream (&stream); return stream.buffer; } static void do_get (const char *name, const char *fqdn, int family) { char *expected = format_expected (fqdn, family, format_get); if (family == AF_INET) { char *query = xasprintf ("gethostbyname (\"%s\")", name); check_hostent (query, gethostbyname (name), expected); free (query); } char *query = xasprintf ("gethostbyname2 (\"%s\", %d)", name, family); check_hostent (query, gethostbyname2 (name, family), expected); /* Test res_search. */ int qtype; switch (family) { case AF_INET: qtype = T_A; break; case AF_INET6: qtype = T_AAAA; break; default: qtype = -1; } if (qtype >= 0) { int sz = 512; unsigned char *response = xmalloc (sz); int ret = res_search (name, C_IN, qtype, response, sz); TEST_VERIFY_EXIT (ret >= 0); if (ret > sz) { /* Truncation. Retry with a larger buffer. */ sz = 65535; unsigned char *newptr = xrealloc (response, sz); response = newptr; ret = res_search (name, C_IN, qtype, response, sz); TEST_VERIFY_EXIT (ret >= 0); TEST_VERIFY_EXIT (ret < sz); } check_dns_packet (query, response, ret, expected); free (response); } free (query); free (expected); } static void do_gai (const char *name, const char *fqdn, int family) { struct addrinfo hints = { .ai_family = family, .ai_protocol = IPPROTO_TCP, .ai_socktype = SOCK_STREAM }; struct addrinfo *ai; char *query = xasprintf ("%s:80 [%d]", name, family); int ret = getaddrinfo (name, "80", &hints, &ai); char *expected = format_expected (fqdn, family, format_gai); check_addrinfo (query, ai, ret, expected); if (ret == 0) freeaddrinfo (ai); free (expected); free (query); } static void do_both (const char *name, const char *fqdn) { do_get (name, fqdn, AF_INET); do_get (name, fqdn, AF_INET6); do_gai (name, fqdn, AF_INET); do_gai (name, fqdn, AF_INET6); do_gai (name, fqdn, AF_UNSPEC); } static void do_test_all (bool unconnectable_server) { struct resolv_redirect_config config = { .response_callback = response, .search = {"usersys.example.com", "corp.example.com", "example.com"}, }; struct resolv_test *obj = resolv_test_start (config); if (unconnectable_server) { /* 255.255.255.255 results in an immediate connect failure. The next server will supply the answer instead. This is a triggering condition for bug 19791. */ _res.nsaddr_list[0].sin_addr.s_addr = -1; _res.nsaddr_list[0].sin_port = htons (53); } do_both ("file", "file.corp.example.com"); do_both ("www", "www.example.com"); do_both ("servfail-usersys", "servfail-usersys.corp.example.com"); do_both ("servfail-corp", "servfail-corp.usersys.example.com"); do_both ("large", "large.example.com"); do_both ("large-servfail", "large-servfail.example.com"); do_both ("file.corp", "file.corp"); /* Check that SERVFAIL and REFUSED responses do not alter the search path resolution. */ rcode_override_server_index = 0; rcode_override = ns_r_servfail; do_both ("hostname", "hostname.usersys.example.com"); do_both ("large", "large.example.com"); do_both ("large-servfail", "large-servfail.example.com"); rcode_override = ns_r_refused; do_both ("hostname", "hostname.usersys.example.com"); do_both ("large", "large.example.com"); do_both ("large-servfail", "large-servfail.example.com"); /* Likewise, but with an NXDOMAIN for the first search path entry. */ rcode_override = ns_r_servfail; do_both ("mail", "mail.corp.example.com"); rcode_override = ns_r_refused; do_both ("mail", "mail.corp.example.com"); /* Likewise, but with ndots handling. */ rcode_override = ns_r_servfail; do_both ("file.corp", "file.corp"); rcode_override = ns_r_refused; do_both ("file.corp", "file.corp"); resolv_test_end (obj); } static int do_test (void) { for (int unconnectable_server = 0; unconnectable_server < 2; ++unconnectable_server) do_test_all (unconnectable_server); return 0; } #include