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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* 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 http://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
/*
* A simple database driver that returns basic information about
* files and directories in the Unix file system as DNS data.
*/
#include <config.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <isc/mem.h>
#include <isc/print.h>
#include <isc/result.h>
#include <isc/util.h>
#include <dns/sdb.h>
#include <named/globals.h>
#include "dirdb.h"
static dns_sdbimplementation_t *dirdb = NULL;
#define CHECK(op) \
do { result = (op); \
if (result != ISC_R_SUCCESS) return (result); \
} while (0)
#define CHECKN(op) \
do { n = (op); \
if (n < 0) return (ISC_R_FAILURE); \
} while (0)
/*
* This database operates on relative names.
*
* Any name will be interpreted as a pathname offset from the directory
* specified in the configuration file.
*/
#ifdef DNS_CLIENTINFO_VERSION
static isc_result_t
dirdb_lookup(const char *zone, const char *name, void *dbdata,
dns_sdblookup_t *lookup, dns_clientinfomethods_t *methods,
dns_clientinfo_t *clientinfo)
#else
static isc_result_t
dirdb_lookup(const char *zone, const char *name, void *dbdata,
dns_sdblookup_t *lookup)
#endif /* DNS_CLIENTINFO_VERSION */
{
char filename[255];
char filename2[255];
char buf[1024];
struct stat statbuf;
isc_result_t result;
int n;
UNUSED(zone);
UNUSED(dbdata);
#ifdef DNS_CLIENTINFO_VERSION
UNUSED(methods);
UNUSED(clientinfo);
#endif /* DNS_CLIENTINFO_VERSION */
if (strcmp(name, "@") == 0)
snprintf(filename, sizeof(filename), "%s", (char *)dbdata);
else
snprintf(filename, sizeof(filename), "%s/%s",
(char *)dbdata, name);
CHECKN(lstat(filename, &statbuf));
if (S_ISDIR(statbuf.st_mode))
CHECK(dns_sdb_putrr(lookup, "txt", 3600, "dir"));
else if (S_ISCHR(statbuf.st_mode) || S_ISBLK(statbuf.st_mode)) {
CHECKN(snprintf(buf, sizeof(buf),
"\"%sdev\" \"major %d\" \"minor %d\"",
S_ISCHR(statbuf.st_mode) ? "chr" : "blk",
major(statbuf.st_rdev),
minor(statbuf.st_rdev)));
CHECK(dns_sdb_putrr(lookup, "txt", 3600, buf));
} else if (S_ISFIFO(statbuf.st_mode))
CHECK(dns_sdb_putrr(lookup, "txt", 3600, "pipe"));
else if (S_ISSOCK(statbuf.st_mode))
CHECK(dns_sdb_putrr(lookup, "txt", 3600, "socket"));
else if (S_ISLNK(statbuf.st_mode)) {
CHECKN(readlink(filename, filename2, sizeof(filename2) - 1));
buf[n] = 0;
CHECKN(snprintf(buf, sizeof(buf), "\"symlink\" \"%s\"",
filename2));
CHECK(dns_sdb_putrr(lookup, "txt", 3600, buf));
} else if (!S_ISREG(statbuf.st_mode))
CHECK(dns_sdb_putrr(lookup, "txt", 3600, "unknown"));
else {
CHECKN(snprintf(buf, sizeof(buf), "\"file\" \"size = %u\"",
(unsigned int)statbuf.st_size));
CHECK(dns_sdb_putrr(lookup, "txt", 3600, buf));
}
return (ISC_R_SUCCESS);
}
/*
* lookup () does not return SOA or NS records, so authority() must be defined.
*/
static isc_result_t
dirdb_authority(const char *zone, void *dbdata, dns_sdblookup_t *lookup) {
isc_result_t result;
UNUSED(zone);
UNUSED(dbdata);
result = dns_sdb_putsoa(lookup, "ns", "hostmaster", 0);
INSIST(result == ISC_R_SUCCESS);
result = dns_sdb_putrr(lookup, "ns", 86400, "ns1");
INSIST(result == ISC_R_SUCCESS);
result = dns_sdb_putrr(lookup, "ns", 86400, "ns2");
INSIST(result == ISC_R_SUCCESS);
return (ISC_R_SUCCESS);
}
/*
* Each database stores the top-level directory as the dbdata opaque
* object. The create() function allocates it. argv[0] holds the top
* level directory.
*/
static isc_result_t
dirdb_create(const char *zone, int argc, char **argv,
void *driverdata, void **dbdata)
{
UNUSED(zone);
UNUSED(driverdata);
if (argc < 1)
return (ISC_R_FAILURE);
*dbdata = isc_mem_strdup((isc_mem_t *)driverdata, argv[0]);
if (*dbdata == NULL)
return (ISC_R_NOMEMORY);
return (ISC_R_SUCCESS);
}
/*
* The destroy() function frees the memory allocated by create().
*/
static void
dirdb_destroy(const char *zone, void *driverdata, void **dbdata) {
UNUSED(zone);
UNUSED(driverdata);
isc_mem_free((isc_mem_t *)driverdata, *dbdata);
}
/*
* This zone does not support zone transfer, so allnodes() is NULL.
*/
static dns_sdbmethods_t dirdb_methods = {
dirdb_lookup,
dirdb_authority,
NULL, /* allnodes */
dirdb_create,
dirdb_destroy,
NULL /* lookup2 */
};
/*
* Wrapper around dns_sdb_register(). Note that the first ns_g_mctx is
* being passed as the "driverdata" parameter, so that will it will be
* passed to create() and destroy().
*/
isc_result_t
dirdb_init(void) {
unsigned int flags;
flags = DNS_SDBFLAG_RELATIVEOWNER | DNS_SDBFLAG_RELATIVERDATA |
DNS_SDBFLAG_THREADSAFE;
return (dns_sdb_register("dir", &dirdb_methods, ns_g_mctx, flags,
ns_g_mctx, &dirdb));
}
/*
* Wrapper around dns_sdb_unregister().
*/
void
dirdb_clear(void) {
if (dirdb != NULL)
dns_sdb_unregister(&dirdb);
}
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