1/*-
2 * Copyright (c) 2011-2012 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by Christos Zoulas.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30/*
31 * NPF variables are used to build the intermediate representation (IR)
32 * of the configuration grammar.  They represent primitive types (strings,
33 * numbers, etc) as well as complex types (address and mask, table, etc).
34 */
35
36#include <sys/cdefs.h>
37__RCSID("$NetBSD: npf_var.c,v 1.13 2020/05/30 14:16:56 rmind Exp $");
38
39#include <stdlib.h>
40#include <string.h>
41#include <unistd.h>
42
43#define _NPFVAR_PRIVATE
44#include "npfctl.h"
45
46typedef struct npf_element {
47	void *		e_data;
48	unsigned	e_type;
49	struct npf_element *e_next;
50} npf_element_t;
51
52struct npfvar {
53	char *		v_key;
54	npf_element_t *	v_elements;
55	npf_element_t *	v_last;
56	size_t		v_count;
57	void *		v_next;
58};
59
60static npfvar_t *	var_list = NULL;
61static size_t		var_num = 0;
62
63npfvar_t *
64npfvar_create(void)
65{
66	npfvar_t *vp = ecalloc(1, sizeof(*vp));
67	var_num++;
68	return vp;
69}
70
71npfvar_t *
72npfvar_lookup(const char *key)
73{
74	for (npfvar_t *it = var_list; it != NULL; it = it->v_next)
75		if (strcmp(it->v_key, key) == 0)
76			return it;
77	return NULL;
78}
79
80const char *
81npfvar_type(size_t t)
82{
83	if (t >= __arraycount(npfvar_types)) {
84		return "unknown";
85	}
86	return npfvar_types[t];
87}
88
89void
90npfvar_add(npfvar_t *vp, const char *name)
91{
92	vp->v_key = estrdup(name);
93	vp->v_next = var_list;
94	var_list = vp;
95}
96
97npfvar_t *
98npfvar_create_element(unsigned type, const void *data, size_t len)
99{
100	npfvar_t *vp = npfvar_create();
101	return npfvar_add_element(vp, type, data, len);
102}
103
104npfvar_t *
105npfvar_create_from_string(unsigned type, const char *string)
106{
107	return npfvar_create_element(type, string, strlen(string) + 1);
108}
109
110npfvar_t *
111npfvar_add_element(npfvar_t *vp, unsigned type, const void *data, size_t len)
112{
113	npf_element_t *el;
114
115	el = ecalloc(1, sizeof(*el));
116	el->e_data = ecalloc(1, len);
117	el->e_type = type;
118	memcpy(el->e_data, data, len);
119
120	/* Preserve the order of insertion. */
121	if (vp->v_elements == NULL) {
122		vp->v_elements = el;
123	} else {
124		vp->v_last->e_next = el;
125	}
126	vp->v_last = el;
127	vp->v_count++;
128	return vp;
129}
130
131npfvar_t *
132npfvar_add_elements(npfvar_t *vp, npfvar_t *vp2)
133{
134	if (vp2 == NULL)
135		return vp;
136	if (vp == NULL)
137		return vp2;
138
139	if (vp->v_elements == NULL) {
140		if (vp2->v_elements) {
141			vp->v_elements = vp2->v_elements;
142		}
143	} else if (vp2->v_elements) {
144		vp->v_last->e_next = vp2->v_elements;
145	}
146	if (vp2->v_elements) {
147		vp->v_last = vp2->v_last;
148		vp->v_count += vp2->v_count;
149		vp2->v_elements = NULL;
150		vp2->v_count = 0;
151		vp2->v_last = NULL;
152	}
153	npfvar_destroy(vp2);
154	return vp;
155}
156
157static void
158npfvar_free_elements(npf_element_t *el)
159{
160	if (el == NULL)
161		return;
162	npfvar_free_elements(el->e_next);
163	free(el->e_data);
164	free(el);
165}
166
167void
168npfvar_destroy(npfvar_t *vp)
169{
170	npfvar_free_elements(vp->v_elements);
171	free(vp->v_key);
172	free(vp);
173	var_num--;
174}
175
176char *
177npfvar_expand_string(const npfvar_t *vp)
178{
179	if (npfvar_get_count(vp) != 1) {
180		yyerror("variable '%s' has multiple elements", vp->v_key);
181		return NULL;
182	}
183	return npfvar_get_data(vp, NPFVAR_STRING, 0);
184}
185
186size_t
187npfvar_get_count(const npfvar_t *vp)
188{
189	return vp ? vp->v_count : 0;
190}
191
192static npf_element_t *
193npfvar_get_element(const npfvar_t *vp, size_t idx, size_t level)
194{
195	npf_element_t *el;
196
197	/*
198	 * Verify the parameters.
199	 */
200	if (vp == NULL) {
201		return NULL;
202	}
203	if (level >= var_num) {
204		yyerror("circular dependency for variable '%s'", vp->v_key);
205		return NULL;
206	}
207	if (vp->v_count <= idx) {
208		yyerror("variable '%s' has only %zu elements, requested %zu",
209		    vp->v_key, vp->v_count, idx);
210		return NULL;
211	}
212
213	/*
214	 * Get the element at the given index.
215	 */
216	el = vp->v_elements;
217	while (idx--) {
218		el = el->e_next;
219	}
220
221	/*
222	 * Resolve if it is a reference to another variable.
223	 */
224	if (el->e_type == NPFVAR_VAR_ID) {
225		const npfvar_t *rvp = npfvar_lookup(el->e_data);
226		return npfvar_get_element(rvp, 0, level + 1);
227	}
228	return el;
229}
230
231int
232npfvar_get_type(const npfvar_t *vp, size_t idx)
233{
234	npf_element_t *el = npfvar_get_element(vp, idx, 0);
235	return el ? (int)el->e_type : -1;
236}
237
238void *
239npfvar_get_data(const npfvar_t *vp, unsigned type, size_t idx)
240{
241	npf_element_t *el = npfvar_get_element(vp, idx, 0);
242
243	if (el && NPFVAR_TYPE(el->e_type) != NPFVAR_TYPE(type)) {
244		yyerror("variable '%s' element %zu "
245		    "is of type '%s' rather than '%s'", vp->v_key,
246		    idx, npfvar_type(el->e_type), npfvar_type(type));
247		return NULL;
248	}
249	return el->e_data;
250}
251