1/*
2 * Copyright (c) 2004-2005, 2007-2010
3 *	Todd C. Miller <Todd.Miller@courtesan.com>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
17 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
18 */
19
20#include <config.h>
21
22#include <sys/types.h>
23#include <sys/param.h>
24#include <stdio.h>
25#ifdef STDC_HEADERS
26# include <stdlib.h>
27# include <stddef.h>
28#else
29# ifdef HAVE_STDLIB_H
30#  include <stdlib.h>
31# endif
32#endif /* STDC_HEADERS */
33#ifdef HAVE_STRING_H
34# include <string.h>
35#endif /* HAVE_STRING_H */
36#ifdef HAVE_STRINGS_H
37# include <strings.h>
38#endif /* HAVE_STRING_H */
39#ifdef HAVE_UNISTD_H
40# include <unistd.h>
41#endif /* HAVE_UNISTD_H */
42#include <errno.h>
43
44#include "sudo.h"
45#include "parse.h"
46#include "redblack.h"
47#include <gram.h>
48
49/*
50 * Globals
51 */
52struct rbtree *aliases;
53unsigned int alias_seqno;
54
55/*
56 * Comparison function for the red-black tree.
57 * Aliases are sorted by name with the type used as a tie-breaker.
58 */
59int
60alias_compare(v1, v2)
61    const void *v1, *v2;
62{
63    const struct alias *a1 = (const struct alias *)v1;
64    const struct alias *a2 = (const struct alias *)v2;
65    int res;
66
67    if (v1 == NULL)
68	res = -1;
69    else if (v2 == NULL)
70	res = 1;
71    else if ((res = strcmp(a1->name, a2->name)) == 0)
72	res = a1->type - a2->type;
73    return res;
74}
75
76/*
77 * Search the tree for an alias with the specified name and type.
78 * Returns a pointer to the alias structure or NULL if not found.
79 */
80struct alias *
81alias_find(name, type)
82    char *name;
83    int type;
84{
85    struct alias key;
86    struct rbnode *node;
87    struct alias *a = NULL;
88
89    key.name = name;
90    key.type = type;
91    if ((node = rbfind(aliases, &key)) != NULL) {
92	/*
93	 * Compare the global sequence number with the one stored
94	 * in the alias.  If they match then we've seen this alias
95	 * before and found a loop.
96	 */
97	a = node->data;
98	if (a->seqno == alias_seqno) {
99	    errno = ELOOP;
100	    return NULL;
101	}
102	a->seqno = alias_seqno;
103    } else {
104	errno = ENOENT;
105    }
106    return a;
107}
108
109/*
110 * Add an alias to the aliases redblack tree.
111 * Returns NULL on success and an error string on failure.
112 */
113char *
114alias_add(name, type, members)
115    char *name;
116    int type;
117    struct member *members;
118{
119    static char errbuf[512];
120    struct alias *a;
121
122    a = ecalloc(1, sizeof(*a));
123    a->name = name;
124    a->type = type;
125    /* a->seqno = 0; */
126    list2tq(&a->members, members);
127    if (rbinsert(aliases, a)) {
128	snprintf(errbuf, sizeof(errbuf), "Alias `%s' already defined", name);
129	alias_free(a);
130	return errbuf;
131    }
132    return NULL;
133}
134
135/*
136 * Apply a function to each alias entry and pass in a cookie.
137 */
138void
139alias_apply(func, cookie)
140    int (*func) __P((void *, void *));
141    void *cookie;
142{
143    rbapply(aliases, func, cookie, inorder);
144}
145
146/*
147 * Returns TRUE if there are no aliases, else FALSE.
148 */
149int
150no_aliases()
151{
152    return rbisempty(aliases);
153}
154
155/*
156 * Free memory used by an alias struct and its members.
157 */
158void
159alias_free(v)
160    void *v;
161{
162    struct alias *a = (struct alias *)v;
163    struct member *m;
164    struct sudo_command *c;
165    void *next;
166
167    efree(a->name);
168    for (m = a->members.first; m != NULL; m = next) {
169	next = m->next;
170	if (m->type == COMMAND) {
171		c = (struct sudo_command *) m->name;
172		efree(c->cmnd);
173		efree(c->args);
174	}
175	efree(m->name);
176	efree(m);
177    }
178    efree(a);
179}
180
181/*
182 * Find the named alias, remove it from the tree and return it.
183 */
184struct alias *
185alias_remove(name, type)
186    char *name;
187    int type;
188{
189    struct rbnode *node;
190    struct alias key;
191
192    key.name = name;
193    key.type = type;
194    if ((node = rbfind(aliases, &key)) == NULL) {
195	errno = ENOENT;
196	return NULL;
197    }
198    return rbdelete(aliases, node);
199}
200
201void
202init_aliases()
203{
204    if (aliases != NULL)
205	rbdestroy(aliases, alias_free);
206    aliases = rbcreate(alias_compare);
207}
208