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-rw-r--r--bin/named/builtin.c650
1 files changed, 650 insertions, 0 deletions
diff --git a/bin/named/builtin.c b/bin/named/builtin.c
new file mode 100644
index 0000000..26348fd
--- /dev/null
+++ b/bin/named/builtin.c
@@ -0,0 +1,650 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file
+ * \brief
+ * The built-in "version", "hostname", "id", "authors" and "empty" databases.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/util.h>
+
+#include <dns/sdb.h>
+
+#include <named/builtin.h>
+#include <named/globals.h>
+#include <named/os.h>
+#include <named/server.h>
+
+typedef struct builtin builtin_t;
+
+static isc_result_t
+do_authors_lookup(dns_sdblookup_t *lookup);
+static isc_result_t
+do_dns64_lookup(dns_sdblookup_t *lookup);
+static isc_result_t
+do_empty_lookup(dns_sdblookup_t *lookup);
+static isc_result_t
+do_hostname_lookup(dns_sdblookup_t *lookup);
+static isc_result_t
+do_id_lookup(dns_sdblookup_t *lookup);
+static isc_result_t
+do_ipv4only_lookup(dns_sdblookup_t *lookup);
+static isc_result_t
+do_ipv4reverse_lookup(dns_sdblookup_t *lookup);
+static isc_result_t
+do_version_lookup(dns_sdblookup_t *lookup);
+
+/*
+ * We can't use function pointers as the db_data directly
+ * because ANSI C does not guarantee that function pointers
+ * can safely be cast to void pointers and back.
+ */
+
+struct builtin {
+ isc_result_t (*do_lookup)(dns_sdblookup_t *lookup);
+ char *server;
+ char *contact;
+};
+
+static builtin_t authors_builtin = { do_authors_lookup, NULL, NULL };
+static builtin_t dns64_builtin = { do_dns64_lookup, NULL, NULL };
+static builtin_t empty_builtin = { do_empty_lookup, NULL, NULL };
+static builtin_t hostname_builtin = { do_hostname_lookup, NULL, NULL };
+static builtin_t id_builtin = { do_id_lookup, NULL, NULL };
+static builtin_t ipv4only_builtin = { do_ipv4only_lookup, NULL, NULL };
+static builtin_t ipv4reverse_builtin = { do_ipv4reverse_lookup, NULL, NULL };
+static builtin_t version_builtin = { do_version_lookup, NULL, NULL };
+
+static dns_sdbimplementation_t *builtin_impl;
+static dns_sdbimplementation_t *dns64_impl;
+
+/*
+ * Pre computed HEX * 16 or 1 table.
+ */
+static const unsigned char hex16[256] = {
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*00*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*10*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*20*/
+ 0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 1, 1, 1, 1, 1, 1, /*30*/
+ 1, 160, 176, 192, 208, 224, 240, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*40*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*50*/
+ 1, 160, 176, 192, 208, 224, 240, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*60*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*70*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*80*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*90*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*A0*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*B0*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*C0*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*D0*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /*E0*/
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 /*F0*/
+};
+
+static const unsigned char decimal[] = "0123456789";
+static const unsigned char ipv4only[] = "\010ipv4only\004arpa";
+
+static size_t
+dns64_rdata(unsigned char *v, size_t start, unsigned char *rdata) {
+ size_t i, j = 0;
+
+ for (i = 0; i < 4U; i++) {
+ unsigned char c = v[start++];
+ if (start == 7U) {
+ start++;
+ }
+ if (c > 99) {
+ rdata[j++] = 3;
+ rdata[j++] = decimal[c / 100];
+ c = c % 100;
+ rdata[j++] = decimal[c / 10];
+ c = c % 10;
+ rdata[j++] = decimal[c];
+ } else if (c > 9) {
+ rdata[j++] = 2;
+ rdata[j++] = decimal[c / 10];
+ c = c % 10;
+ rdata[j++] = decimal[c];
+ } else {
+ rdata[j++] = 1;
+ rdata[j++] = decimal[c];
+ }
+ }
+ memmove(&rdata[j], "\07in-addr\04arpa", 14);
+ return (j + 14);
+}
+
+static isc_result_t
+dns64_cname(const dns_name_t *zone, const dns_name_t *name,
+ dns_sdblookup_t *lookup) {
+ size_t zlen, nlen, j, len;
+ unsigned char v[16], n;
+ unsigned int i;
+ unsigned char rdata[sizeof("123.123.123.123.in-addr.arpa.")];
+ unsigned char *ndata;
+
+ /*
+ * The combined length of the zone and name is 74.
+ *
+ * The minimum zone length is 10 ((3)ip6(4)arpa(0)).
+ *
+ * The length of name should always be even as we are expecting
+ * a series of nibbles.
+ */
+ zlen = zone->length;
+ nlen = name->length;
+ if ((zlen + nlen) > 74U || zlen < 10U || (nlen % 2) != 0U) {
+ return (ISC_R_NOTFOUND);
+ }
+
+ /*
+ * We assume the zone name is well formed.
+ */
+
+ /*
+ * XXXMPA We could check the dns64 suffix here if we need to.
+ */
+ /*
+ * Check that name is a series of nibbles.
+ * Compute the byte values that correspond to the nibbles as we go.
+ *
+ * Shift the final result 4 bits, by setting 'i' to 1, if we if we
+ * have a odd number of nibbles so that "must be zero" tests below
+ * are byte aligned and we correctly return ISC_R_NOTFOUND or
+ * ISC_R_SUCCESS. We will not generate a CNAME in this case.
+ */
+ ndata = name->ndata;
+ i = (nlen % 4) == 2U ? 1 : 0;
+ j = nlen;
+ memset(v, 0, sizeof(v));
+ while (j != 0U) {
+ INSIST((i / 2) < sizeof(v));
+ if (ndata[0] != 1) {
+ return (ISC_R_NOTFOUND);
+ }
+ n = hex16[ndata[1] & 0xff];
+ if (n == 1) {
+ return (ISC_R_NOTFOUND);
+ }
+ v[i / 2] = n | (v[i / 2] >> 4);
+ j -= 2;
+ ndata += 2;
+ i++;
+ }
+
+ /*
+ * If we get here then we know name only consisted of nibbles.
+ * Now we need to determine if the name exists or not and whether
+ * it corresponds to a empty node in the zone or there should be
+ * a CNAME.
+ */
+#define ZLEN(x) (10 + (x) / 2)
+ switch (zlen) {
+ case ZLEN(32): /* prefix len 32 */
+ /*
+ * The nibbles that map to this byte must be zero for 'name'
+ * to exist in the zone.
+ */
+ if (nlen > 16U && v[(nlen - 1) / 4 - 4] != 0) {
+ return (ISC_R_NOTFOUND);
+ }
+ /*
+ * If the total length is not 74 then this is a empty node
+ * so return success.
+ */
+ if (nlen + zlen != 74U) {
+ return (ISC_R_SUCCESS);
+ }
+ len = dns64_rdata(v, 8, rdata);
+ break;
+ case ZLEN(40): /* prefix len 40 */
+ /*
+ * The nibbles that map to this byte must be zero for 'name'
+ * to exist in the zone.
+ */
+ if (nlen > 12U && v[(nlen - 1) / 4 - 3] != 0) {
+ return (ISC_R_NOTFOUND);
+ }
+ /*
+ * If the total length is not 74 then this is a empty node
+ * so return success.
+ */
+ if (nlen + zlen != 74U) {
+ return (ISC_R_SUCCESS);
+ }
+ len = dns64_rdata(v, 6, rdata);
+ break;
+ case ZLEN(48): /* prefix len 48 */
+ /*
+ * The nibbles that map to this byte must be zero for 'name'
+ * to exist in the zone.
+ */
+ if (nlen > 8U && v[(nlen - 1) / 4 - 2] != 0) {
+ return (ISC_R_NOTFOUND);
+ }
+ /*
+ * If the total length is not 74 then this is a empty node
+ * so return success.
+ */
+ if (nlen + zlen != 74U) {
+ return (ISC_R_SUCCESS);
+ }
+ len = dns64_rdata(v, 5, rdata);
+ break;
+ case ZLEN(56): /* prefix len 56 */
+ /*
+ * The nibbles that map to this byte must be zero for 'name'
+ * to exist in the zone.
+ */
+ if (nlen > 4U && v[(nlen - 1) / 4 - 1] != 0) {
+ return (ISC_R_NOTFOUND);
+ }
+ /*
+ * If the total length is not 74 then this is a empty node
+ * so return success.
+ */
+ if (nlen + zlen != 74U) {
+ return (ISC_R_SUCCESS);
+ }
+ len = dns64_rdata(v, 4, rdata);
+ break;
+ case ZLEN(64): /* prefix len 64 */
+ /*
+ * The nibbles that map to this byte must be zero for 'name'
+ * to exist in the zone.
+ */
+ if (v[(nlen - 1) / 4] != 0) {
+ return (ISC_R_NOTFOUND);
+ }
+ /*
+ * If the total length is not 74 then this is a empty node
+ * so return success.
+ */
+ if (nlen + zlen != 74U) {
+ return (ISC_R_SUCCESS);
+ }
+ len = dns64_rdata(v, 3, rdata);
+ break;
+ case ZLEN(96): /* prefix len 96 */
+ /*
+ * If the total length is not 74 then this is a empty node
+ * so return success.
+ */
+ if (nlen + zlen != 74U) {
+ return (ISC_R_SUCCESS);
+ }
+ len = dns64_rdata(v, 0, rdata);
+ break;
+ default:
+ /*
+ * This should never be reached unless someone adds a
+ * zone declaration with this internal type to named.conf.
+ */
+ return (ISC_R_NOTFOUND);
+ }
+
+ /*
+ * Reverse of 192.0.0.170 or 192.0.0.171 maps to ipv4only.arpa.
+ */
+ if ((v[0] == 170 || v[0] == 171) && v[1] == 0 && v[2] == 0 &&
+ v[3] == 192)
+ {
+ return (dns_sdb_putrdata(lookup, dns_rdatatype_ptr, 3600,
+ ipv4only, sizeof(ipv4only)));
+ }
+
+ return (dns_sdb_putrdata(lookup, dns_rdatatype_cname, 600, rdata,
+ (unsigned int)len));
+}
+
+static isc_result_t
+builtin_lookup(const char *zone, const char *name, void *dbdata,
+ dns_sdblookup_t *lookup, dns_clientinfomethods_t *methods,
+ dns_clientinfo_t *clientinfo) {
+ builtin_t *b = (builtin_t *)dbdata;
+
+ UNUSED(zone);
+ UNUSED(methods);
+ UNUSED(clientinfo);
+
+ if (strcmp(name, "@") == 0) {
+ return (b->do_lookup(lookup));
+ } else {
+ return (ISC_R_NOTFOUND);
+ }
+}
+
+static isc_result_t
+dns64_lookup(const dns_name_t *zone, const dns_name_t *name, void *dbdata,
+ dns_sdblookup_t *lookup, dns_clientinfomethods_t *methods,
+ dns_clientinfo_t *clientinfo) {
+ builtin_t *b = (builtin_t *)dbdata;
+
+ UNUSED(methods);
+ UNUSED(clientinfo);
+
+ if (name->labels == 0 && name->length == 0) {
+ return (b->do_lookup(lookup));
+ } else {
+ return (dns64_cname(zone, name, lookup));
+ }
+}
+
+static isc_result_t
+put_txt(dns_sdblookup_t *lookup, const char *text) {
+ unsigned char buf[256];
+ unsigned int len = strlen(text);
+ if (len > 255) {
+ len = 255; /* Silently truncate */
+ }
+ buf[0] = len;
+ memmove(&buf[1], text, len);
+ return (dns_sdb_putrdata(lookup, dns_rdatatype_txt, 0, buf, len + 1));
+}
+
+static isc_result_t
+do_version_lookup(dns_sdblookup_t *lookup) {
+ if (named_g_server->version_set) {
+ if (named_g_server->version == NULL) {
+ return (ISC_R_SUCCESS);
+ } else {
+ return (put_txt(lookup, named_g_server->version));
+ }
+ } else {
+ return (put_txt(lookup, PACKAGE_VERSION));
+ }
+}
+
+static isc_result_t
+do_hostname_lookup(dns_sdblookup_t *lookup) {
+ if (named_g_server->hostname_set) {
+ if (named_g_server->hostname == NULL) {
+ return (ISC_R_SUCCESS);
+ } else {
+ return (put_txt(lookup, named_g_server->hostname));
+ }
+ } else {
+ char buf[256];
+ if (gethostname(buf, sizeof(buf)) != 0) {
+ return (ISC_R_FAILURE);
+ }
+ return (put_txt(lookup, buf));
+ }
+}
+
+static isc_result_t
+do_authors_lookup(dns_sdblookup_t *lookup) {
+ isc_result_t result;
+ const char **p;
+ static const char *authors[] = {
+ "Mark Andrews", "Curtis Blackburn", "James Brister",
+ "Ben Cottrell", "John H. DuBois III", "Francis Dupont",
+ "Michael Graff", "Andreas Gustafsson", "Bob Halley",
+ "Evan Hunt", "JINMEI Tatuya", "Witold Krecicki",
+ "David Lawrence", "Scott Mann", "Danny Mayer",
+ "Damien Neil", "Matt Nelson", "Jeremy C. Reed",
+ "Michael Sawyer", "Brian Wellington", NULL
+ };
+
+ /*
+ * If a version string is specified, disable the authors.bind zone.
+ */
+ if (named_g_server->version_set) {
+ return (ISC_R_SUCCESS);
+ }
+
+ for (p = authors; *p != NULL; p++) {
+ result = put_txt(lookup, *p);
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ }
+ return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+do_id_lookup(dns_sdblookup_t *lookup) {
+ if (named_g_server->sctx->usehostname) {
+ char buf[256];
+ if (gethostname(buf, sizeof(buf)) != 0) {
+ return (ISC_R_FAILURE);
+ }
+ return (put_txt(lookup, buf));
+ } else if (named_g_server->sctx->server_id != NULL) {
+ return (put_txt(lookup, named_g_server->sctx->server_id));
+ } else {
+ return (ISC_R_SUCCESS);
+ }
+}
+
+static isc_result_t
+do_dns64_lookup(dns_sdblookup_t *lookup) {
+ UNUSED(lookup);
+ return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+do_empty_lookup(dns_sdblookup_t *lookup) {
+ UNUSED(lookup);
+ return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+do_ipv4only_lookup(dns_sdblookup_t *lookup) {
+ isc_result_t result;
+ unsigned char data[2][4] = { { 192, 0, 0, 170 }, { 192, 0, 0, 171 } };
+
+ for (int i = 0; i < 2; i++) {
+ result = dns_sdb_putrdata(lookup, dns_rdatatype_a, 3600,
+ data[i], 4);
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ }
+ return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+do_ipv4reverse_lookup(dns_sdblookup_t *lookup) {
+ isc_result_t result;
+
+ result = dns_sdb_putrdata(lookup, dns_rdatatype_ptr, 3600, ipv4only,
+ sizeof(ipv4only));
+ return (result);
+}
+
+static isc_result_t
+builtin_authority(const char *zone, void *dbdata, dns_sdblookup_t *lookup) {
+ isc_result_t result;
+ const char *contact = "hostmaster";
+ const char *server = "@";
+ builtin_t *b = (builtin_t *)dbdata;
+
+ UNUSED(zone);
+ UNUSED(dbdata);
+
+ if (b == &empty_builtin) {
+ server = ".";
+ contact = ".";
+ } else {
+ if (b->server != NULL) {
+ server = b->server;
+ }
+ if (b->contact != NULL) {
+ contact = b->contact;
+ }
+ }
+
+ result = dns_sdb_putsoa(lookup, server, contact, 0);
+ if (result != ISC_R_SUCCESS) {
+ return (ISC_R_FAILURE);
+ }
+
+ result = dns_sdb_putrr(lookup, "ns", 0, server);
+ if (result != ISC_R_SUCCESS) {
+ return (ISC_R_FAILURE);
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+builtin_create(const char *zone, int argc, char **argv, void *driverdata,
+ void **dbdata) {
+ REQUIRE(argc >= 1);
+
+ UNUSED(zone);
+ UNUSED(driverdata);
+
+ if (strcmp(argv[0], "dns64") == 0 || strcmp(argv[0], "empty") == 0 ||
+ strcmp(argv[0], "ipv4only") == 0 ||
+ strcmp(argv[0], "ipv4reverse") == 0)
+ {
+ if (argc != 3) {
+ return (DNS_R_SYNTAX);
+ }
+ } else if (argc != 1) {
+ return (DNS_R_SYNTAX);
+ }
+
+ if (strcmp(argv[0], "authors") == 0) {
+ *dbdata = &authors_builtin;
+ } else if (strcmp(argv[0], "hostname") == 0) {
+ *dbdata = &hostname_builtin;
+ } else if (strcmp(argv[0], "id") == 0) {
+ *dbdata = &id_builtin;
+ } else if (strcmp(argv[0], "version") == 0) {
+ *dbdata = &version_builtin;
+ } else if (strcmp(argv[0], "dns64") == 0 ||
+ strcmp(argv[0], "empty") == 0 ||
+ strcmp(argv[0], "ipv4only") == 0 ||
+ strcmp(argv[0], "ipv4reverse") == 0)
+ {
+ builtin_t *empty;
+ char *server;
+ char *contact;
+
+ if (argc != 3) {
+ return (DNS_R_SYNTAX);
+ }
+
+ /*
+ * We don't want built-in zones to fail. Fallback to
+ * the static configuration if memory allocation fails.
+ */
+ empty = isc_mem_get(named_g_mctx, sizeof(*empty));
+ server = isc_mem_strdup(named_g_mctx, argv[1]);
+ contact = isc_mem_strdup(named_g_mctx, argv[2]);
+ if (empty == NULL || server == NULL || contact == NULL) {
+ if (strcmp(argv[0], "dns64") == 0) {
+ *dbdata = &dns64_builtin;
+ } else if (strcmp(argv[0], "empty") == 0) {
+ *dbdata = &empty_builtin;
+ } else if (strcmp(argv[0], "ipv4only") == 0) {
+ *dbdata = &ipv4only_builtin;
+ } else {
+ *dbdata = &ipv4reverse_builtin;
+ }
+ if (server != NULL) {
+ isc_mem_free(named_g_mctx, server);
+ }
+ if (contact != NULL) {
+ isc_mem_free(named_g_mctx, contact);
+ }
+ if (empty != NULL) {
+ isc_mem_put(named_g_mctx, empty,
+ sizeof(*empty));
+ }
+ } else {
+ if (strcmp(argv[0], "dns64") == 0) {
+ memmove(empty, &dns64_builtin,
+ sizeof(empty_builtin));
+ } else if (strcmp(argv[0], "empty") == 0) {
+ memmove(empty, &empty_builtin,
+ sizeof(empty_builtin));
+ } else if (strcmp(argv[0], "ipv4only") == 0) {
+ memmove(empty, &ipv4only_builtin,
+ sizeof(empty_builtin));
+ } else {
+ memmove(empty, &ipv4reverse_builtin,
+ sizeof(empty_builtin));
+ }
+ empty->server = server;
+ empty->contact = contact;
+ *dbdata = empty;
+ }
+ } else {
+ return (ISC_R_NOTIMPLEMENTED);
+ }
+ return (ISC_R_SUCCESS);
+}
+
+static void
+builtin_destroy(const char *zone, void *driverdata, void **dbdata) {
+ builtin_t *b = (builtin_t *)*dbdata;
+
+ UNUSED(zone);
+ UNUSED(driverdata);
+
+ /*
+ * Don't free the static versions.
+ */
+ if (*dbdata == &authors_builtin || *dbdata == &dns64_builtin ||
+ *dbdata == &empty_builtin || *dbdata == &hostname_builtin ||
+ *dbdata == &id_builtin || *dbdata == &ipv4only_builtin ||
+ *dbdata == &ipv4reverse_builtin || *dbdata == &version_builtin)
+ {
+ return;
+ }
+
+ isc_mem_free(named_g_mctx, b->server);
+ isc_mem_free(named_g_mctx, b->contact);
+ isc_mem_put(named_g_mctx, b, sizeof(*b));
+}
+
+static dns_sdbmethods_t builtin_methods = {
+ builtin_lookup, builtin_authority, NULL, /* allnodes */
+ builtin_create, builtin_destroy, NULL
+};
+
+static dns_sdbmethods_t dns64_methods = {
+ NULL, builtin_authority, NULL, /* allnodes */
+ builtin_create, builtin_destroy, dns64_lookup,
+};
+
+isc_result_t
+named_builtin_init(void) {
+ RUNTIME_CHECK(dns_sdb_register("_builtin", &builtin_methods, NULL,
+ DNS_SDBFLAG_RELATIVEOWNER |
+ DNS_SDBFLAG_RELATIVERDATA,
+ named_g_mctx,
+ &builtin_impl) == ISC_R_SUCCESS);
+ RUNTIME_CHECK(dns_sdb_register("_dns64", &dns64_methods, NULL,
+ DNS_SDBFLAG_RELATIVEOWNER |
+ DNS_SDBFLAG_RELATIVERDATA |
+ DNS_SDBFLAG_DNS64,
+ named_g_mctx,
+ &dns64_impl) == ISC_R_SUCCESS);
+ return (ISC_R_SUCCESS);
+}
+
+void
+named_builtin_deinit(void) {
+ dns_sdb_unregister(&builtin_impl);
+ dns_sdb_unregister(&dns64_impl);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 09:22:00 +0000