summaryrefslogtreecommitdiffstats
path: root/contrib/sdb/tcl/tcldb.c
blob: de6f4c58a447ca3ad4bdb3fa20652d3bfc5ac9eb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
/*
 * Copyright (C) 2004, 2007  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: tcldb.c,v 1.10 2007/06/19 23:47:10 tbox Exp $ */

/*
 * A simple database driver that calls a Tcl procedure to define
 * the contents of the DNS namespace.  The procedure is loaded
 * from the file lookup.tcl; look at the comments there for
 * more information.
 */

#include <config.h>

#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>

#include <isc/mem.h>
#include <isc/print.h>
#include <isc/result.h>
#include <isc/util.h>

#include <dns/log.h>
#include <dns/sdb.h>

#include <named/globals.h>

#include <tcl.h>

#include <tcldb.h>

#define CHECK(op)						\
	do { result = (op);					\
		if (result != ISC_R_SUCCESS) return (result);	\
	} while (0)

typedef struct tcldb_driver {
	isc_mem_t *mctx;
	Tcl_Interp *interp;
} tcldb_driver_t;

static tcldb_driver_t *the_driver = NULL;

static dns_sdbimplementation_t *tcldb = NULL;

static isc_result_t
tcldb_driver_create(isc_mem_t *mctx, tcldb_driver_t **driverp) {
	int tclres;
	isc_result_t result = ISC_R_SUCCESS;
	tcldb_driver_t *driver = isc_mem_get(mctx, sizeof(tcldb_driver_t));
	if (driver == NULL)
		return (ISC_R_NOMEMORY);
	driver->mctx = mctx;
	driver->interp = Tcl_CreateInterp();

	tclres = Tcl_EvalFile(driver->interp, (char *) "lookup.tcl");
	if (tclres != TCL_OK) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
			      DNS_LOGMODULE_SDB, ISC_LOG_ERROR,
			      "initializing tcldb: "
			      "loading 'lookup.tcl' failed: %s",
			      driver->interp->result);
		result = ISC_R_FAILURE;
		goto cleanup;
	}
	*driverp = driver;
	return (ISC_R_SUCCESS);

 cleanup:
	isc_mem_put(mctx, driver, sizeof(tcldb_driver_t));
	return (result);
	
}

static void
tcldb_driver_destroy(tcldb_driver_t **driverp) {
	tcldb_driver_t *driver = *driverp;
	Tcl_DeleteInterp(driver->interp);
	isc_mem_put(driver->mctx, driver, sizeof(tcldb_driver_t));
}

/*
 * Perform a lookup, by invoking the Tcl procedure "lookup".
 */
static isc_result_t
tcldb_lookup(const char *zone, const char *name, void *dbdata,
	      dns_sdblookup_t *lookup)
{
	isc_result_t result = ISC_R_SUCCESS;
	int tclres;
	int rrc;	/* RR count */
	char **rrv;	/* RR vector */
	int i;
	char *cmdv[3];
	char *cmd;

	tcldb_driver_t *driver = (tcldb_driver_t *) dbdata;

	cmdv[0] = "lookup";
	cmdv[1] = zone;
	cmdv[2] = name;
	cmd = Tcl_Merge(3, cmdv);
	tclres = Tcl_Eval(driver->interp, cmd);
	Tcl_Free(cmd);

	if (tclres != TCL_OK) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
			      DNS_LOGMODULE_SDB, ISC_LOG_ERROR,
			      "zone '%s': tcl lookup function failed: %s",
			      zone, driver->interp->result);
		return (ISC_R_FAILURE);
	}

	if (strcmp(driver->interp->result, "NXDOMAIN") == 0) {
		result = ISC_R_NOTFOUND;
		goto fail;
	}

	tclres = Tcl_SplitList(driver->interp, driver->interp->result,
			       &rrc, &rrv);
	if (tclres != TCL_OK)
		goto malformed;

	for (i = 0; i < rrc; i++) {
		isc_result_t tmpres;
		int fieldc;	/* Field count */
		char **fieldv;	/* Field vector */
		tclres = Tcl_SplitList(driver->interp, rrv[i],
				       &fieldc, &fieldv);
		if (tclres != TCL_OK) {
			tmpres = ISC_R_FAILURE;
			goto failrr;
		}
		if (fieldc != 3)
			goto malformed;
		tmpres = dns_sdb_putrr(lookup, fieldv[0], atoi(fieldv[1]),
				       fieldv[2]);
		Tcl_Free((char *) fieldv);
	failrr:
		if (tmpres != ISC_R_SUCCESS)
			result = tmpres;
	}
	Tcl_Free((char *) rrv);
	if (result == ISC_R_SUCCESS)
		return (result);

 malformed:
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
		      DNS_LOGMODULE_SDB, ISC_LOG_ERROR,
		      "zone '%s': "
		      "malformed return value from tcl lookup function: %s",
		      zone, driver->interp->result);
	result = ISC_R_FAILURE;
 fail:
	return (result);
}

/*
 * Set up per-zone state.  In our case, the database arguments of the
 * zone are collected into a Tcl list and assigned to an element of
 * the global array "dbargs".
 */
static isc_result_t
tcldb_create(const char *zone, int argc, char **argv,
	     void *driverdata, void **dbdata)
{
	tcldb_driver_t *driver = (tcldb_driver_t *) driverdata;

	char *list = Tcl_Merge(argc, argv);
	
	Tcl_SetVar2(driver->interp, (char *) "dbargs", (char *) zone, list, 0);

	Tcl_Free(list);

	*dbdata = driverdata;
	
	return (ISC_R_SUCCESS);
}

/*
 * This driver does not support zone transfer, so allnodes() is NULL.
 */
static dns_sdbmethods_t tcldb_methods = {
	tcldb_lookup,
	NULL, /* authority */
	NULL, /* allnodes */
	tcldb_create,
	NULL /* destroy */
};

/*
 * Initialize the tcldb driver.
 */
isc_result_t
tcldb_init(void) {
	isc_result_t result;
	int flags = DNS_SDBFLAG_RELATIVEOWNER | DNS_SDBFLAG_RELATIVERDATA;
	
	result = tcldb_driver_create(ns_g_mctx, &the_driver);
	if (result != ISC_R_SUCCESS)
		return (result);
	
	return (dns_sdb_register("tcl", &tcldb_methods, the_driver, flags,
				 ns_g_mctx, &tcldb));
}

/*
 * Wrapper around dns_sdb_unregister().
 */
void
tcldb_clear(void) {
	if (tcldb != NULL)
		dns_sdb_unregister(&tcldb);
	if (the_driver != NULL)
		tcldb_driver_destroy(&the_driver);
}