1/*	$NetBSD: catgets.c,v 1.18 2008/04/28 20:23:00 martin Exp $	*/
2
3/*-
4 * Copyright (c) 1996 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by J.T. Conklin.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34__RCSID("$NetBSD: catgets.c,v 1.18 2008/04/28 20:23:00 martin Exp $");
35#endif /* LIBC_SCCS and not lint */
36
37#define _NLS_PRIVATE
38
39#include "namespace.h"
40#include <errno.h>
41#include <stdlib.h>
42#include <string.h>
43#include <nl_types.h>
44
45#ifdef __weak_alias
46__weak_alias(catgets, _catgets)
47#endif
48
49char *
50_catgets(nl_catd catd, int set_id, int msg_id, const char *s)
51{
52	struct _nls_cat_hdr *cat_hdr;
53	struct _nls_set_hdr *set_hdr;
54	struct _nls_msg_hdr *msg_hdr;
55	int l, u, i, r;
56
57	if (catd == (nl_catd) -1) {
58		errno = EBADF;
59		return __UNCONST(s);
60	}
61
62	cat_hdr = (struct _nls_cat_hdr *)catd->__data;
63	set_hdr = (struct _nls_set_hdr *)(void *)((char *)catd->__data
64		+ sizeof(struct _nls_cat_hdr));
65
66	/* binary search, see knuth algorithm b */
67	l = 0;
68	u = ntohl((u_int32_t)cat_hdr->__nsets) - 1;
69	while (l <= u) {
70		i = (l + u) / 2;
71		r = set_id - ntohl((u_int32_t)set_hdr[i].__setno);
72
73		if (r == 0) {
74			msg_hdr = (struct _nls_msg_hdr *)
75			    (void *)((char *)catd->__data +
76			    sizeof(struct _nls_cat_hdr) +
77			    ntohl((u_int32_t)cat_hdr->__msg_hdr_offset));
78
79			l = ntohl((u_int32_t)set_hdr[i].__index);
80			u = l + ntohl((u_int32_t)set_hdr[i].__nmsgs) - 1;
81			while (l <= u) {
82				i = (l + u) / 2;
83				r = msg_id -
84				    ntohl((u_int32_t)msg_hdr[i].__msgno);
85				if (r == 0) {
86					return ((char *) catd->__data +
87					    sizeof(struct _nls_cat_hdr) +
88					    ntohl((u_int32_t)
89					    cat_hdr->__msg_txt_offset) +
90					    ntohl((u_int32_t)
91					    msg_hdr[i].__offset));
92				} else if (r < 0) {
93					u = i - 1;
94				} else {
95					l = i + 1;
96				}
97			}
98
99			/* not found */
100			goto notfound;
101
102		} else if (r < 0) {
103			u = i - 1;
104		} else {
105			l = i + 1;
106		}
107	}
108
109notfound:
110	/* not found */
111	errno = ENOMSG;
112	return __UNCONST(s);
113}
114