#include <config.h>
#include <string.h>
#include <stdio.h>
#include <isc/mem.h>
#include <isc/print.h>
#include <isc/result.h>
#include <isc/util.h>
#include <dns/result.h>
#include <dns/sdb.h>
#include <named/builtin.h>
#include <named/globals.h>
#include <named/server.h>
#include <named/os.h>
typedef struct builtin builtin_t;
static isc_result_t do_version_lookup(dns_sdblookup_t *lookup);
static isc_result_t do_hostname_lookup(dns_sdblookup_t *lookup);
static isc_result_t do_authors_lookup(dns_sdblookup_t *lookup);
static isc_result_t do_id_lookup(dns_sdblookup_t *lookup);
static isc_result_t do_empty_lookup(dns_sdblookup_t *lookup);
static isc_result_t do_dns64_lookup(dns_sdblookup_t *lookup);
struct builtin {
isc_result_t (*do_lookup)(dns_sdblookup_t *lookup);
char *server;
char *contact;
};
static builtin_t version_builtin = { do_version_lookup, NULL, NULL };
static builtin_t hostname_builtin = { do_hostname_lookup, NULL, NULL };
static builtin_t authors_builtin = { do_authors_lookup, NULL, NULL };
static builtin_t id_builtin = { do_id_lookup, NULL, NULL };
static builtin_t empty_builtin = { do_empty_lookup, NULL, NULL };
static builtin_t dns64_builtin = { do_dns64_lookup, NULL, NULL };
static dns_sdbimplementation_t *builtin_impl;
static const char hex[] = "0123456789abcdef";
static const char HEX[] = "0123456789ABCDEF";
static isc_result_t
dns64_cname(const char *zone, const char *name, dns_sdblookup_t *lookup) {
size_t zlen, nlen, j;
const char *s;
unsigned char v[16];
unsigned int i;
char reverse[sizeof("123.123.123.123.in-addr.arpa.")];
zlen = strlen(zone);
nlen = strlen(name);
if ((zlen + nlen) > 71U || zlen < 8U || (nlen % 2) != 1U)
return (ISC_R_NOTFOUND);
i = (nlen % 4) == 1U ? 1 : 0;
j = nlen;
memset(v, 0, sizeof(v));
while (j >= 1U) {
INSIST((i/2) < sizeof(v));
if (j > 1U && name[1] != '.')
return (ISC_R_NOTFOUND);
v[i/2] >>= 4;
if ((s = strchr(hex, name[0])) != NULL)
v[i/2] |= (s - hex) << 4;
else if ((s = strchr(HEX, name[0])) != NULL)
v[i/2] |= (s - HEX) << 4;
else
return (ISC_R_NOTFOUND);
if (j > 1U)
j -= 2;
else
j -= 1;
name += 2;
i++;
}
switch (zlen) {
case 24:
if (nlen + zlen != 71U)
return (ISC_R_SUCCESS);
snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
v[8], v[9], v[10], v[11]);
break;
case 28:
if (nlen > 11U && v[nlen/4 - 3] != 0)
return (ISC_R_NOTFOUND);
if (nlen + zlen != 71U)
return (ISC_R_SUCCESS);
snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
v[6], v[8], v[9], v[10]);
break;
case 32:
if (nlen > 7U && v[nlen/4 - 2] != 0)
return (ISC_R_NOTFOUND);
if (nlen + zlen != 71U)
return (ISC_R_SUCCESS);
snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
v[5], v[6], v[8], v[9]);
break;
case 36:
if (nlen > 3U && v[nlen/4 - 1] != 0)
return (ISC_R_NOTFOUND);
if (nlen + zlen != 71U)
return (ISC_R_SUCCESS);
snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
v[4], v[5], v[6], v[8]);
break;
case 40:
if (v[nlen/4] != 0)
return (ISC_R_NOTFOUND);
if (nlen + zlen != 71U)
return (ISC_R_SUCCESS);
snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
v[3], v[4], v[5], v[6]);
break;
case 56:
if (nlen + zlen != 71U)
return (ISC_R_SUCCESS);
snprintf(reverse, sizeof(reverse), "%u.%u.%u.%u.in-addr.arpa.",
v[0], v[1], v[2], v[3]);
break;
default:
return (ISC_R_NOTFOUND);
}
return (dns_sdb_putrr(lookup, "CNAME", 600, reverse));
}
static isc_result_t
builtin_lookup(const char *zone, const char *name, void *dbdata,
dns_sdblookup_t *lookup)
{
builtin_t *b = (builtin_t *) dbdata;
UNUSED(zone);
if (strcmp(name, "@") == 0)
return (b->do_lookup(lookup));
else if (b->do_lookup == do_dns64_lookup)
return (dns64_cname(zone, name, lookup));
else
return (ISC_R_NOTFOUND);
}
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;
buf[0] = len;
memcpy(&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 (ns_g_server->version_set) {
if (ns_g_server->version == NULL)
return (ISC_R_SUCCESS);
else
return (put_txt(lookup, ns_g_server->version));
} else {
return (put_txt(lookup, ns_g_version));
}
}
static isc_result_t
do_hostname_lookup(dns_sdblookup_t *lookup) {
if (ns_g_server->hostname_set) {
if (ns_g_server->hostname == NULL)
return (ISC_R_SUCCESS);
else
return (put_txt(lookup, ns_g_server->hostname));
} else {
char buf[256];
isc_result_t result = ns_os_gethostname(buf, sizeof(buf));
if (result != ISC_R_SUCCESS)
return (result);
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",
"James Brister",
"Ben Cottrell",
"Michael Graff",
"Andreas Gustafsson",
"Bob Halley",
"Evan Hunt",
"JINMEI Tatuya",
"David Lawrence",
"Danny Mayer",
"Damien Neil",
"Matt Nelson",
"Jeremy C. Reed",
"Michael Sawyer",
"Brian Wellington",
NULL
};
if (ns_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 (ns_g_server->server_usehostname) {
char buf[256];
isc_result_t result = ns_os_gethostname(buf, sizeof(buf));
if (result != ISC_R_SUCCESS)
return (result);
return (put_txt(lookup, buf));
}
if (ns_g_server->server_id == NULL)
return (ISC_R_SUCCESS);
else
return (put_txt(lookup, ns_g_server->server_id));
}
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
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], "empty") == 0 || strcmp(argv[0], "dns64") == 0) {
if (argc != 3)
return (DNS_R_SYNTAX);
} else if (argc != 1)
return (DNS_R_SYNTAX);
if (strcmp(argv[0], "version") == 0)
*dbdata = &version_builtin;
else if (strcmp(argv[0], "hostname") == 0)
*dbdata = &hostname_builtin;
else if (strcmp(argv[0], "authors") == 0)
*dbdata = &authors_builtin;
else if (strcmp(argv[0], "id") == 0)
*dbdata = &id_builtin;
else if (strcmp(argv[0], "empty") == 0 ||
strcmp(argv[0], "dns64") == 0) {
builtin_t *empty;
char *server;
char *contact;
empty = isc_mem_get(ns_g_mctx, sizeof(*empty));
server = isc_mem_strdup(ns_g_mctx, argv[1]);
contact = isc_mem_strdup(ns_g_mctx, argv[2]);
if (empty == NULL || server == NULL || contact == NULL) {
if (strcmp(argv[0], "empty") == 0)
*dbdata = &empty_builtin;
else
*dbdata = &dns64_builtin;
if (server != NULL)
isc_mem_free(ns_g_mctx, server);
if (contact != NULL)
isc_mem_free(ns_g_mctx, contact);
if (empty != NULL)
isc_mem_put(ns_g_mctx, empty, sizeof (*empty));
} else {
if (strcmp(argv[0], "empty") == 0)
memcpy(empty, &empty_builtin,
sizeof (empty_builtin));
else
memcpy(empty, &dns64_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);
if (*dbdata == &version_builtin || *dbdata == &hostname_builtin ||
*dbdata == &authors_builtin || *dbdata == &id_builtin ||
*dbdata == &empty_builtin || *dbdata == &dns64_builtin)
return;
isc_mem_free(ns_g_mctx, b->server);
isc_mem_free(ns_g_mctx, b->contact);
isc_mem_put(ns_g_mctx, b, sizeof (*b));
}
static dns_sdbmethods_t builtin_methods = {
builtin_lookup,
builtin_authority,
NULL,
builtin_create,
builtin_destroy
};
isc_result_t
ns_builtin_init(void) {
RUNTIME_CHECK(dns_sdb_register("_builtin", &builtin_methods, NULL,
DNS_SDBFLAG_RELATIVEOWNER |
DNS_SDBFLAG_RELATIVERDATA,
ns_g_mctx, &builtin_impl)
== ISC_R_SUCCESS);
return (ISC_R_SUCCESS);
}
void
ns_builtin_deinit(void) {
dns_sdb_unregister(&builtin_impl);
}