pathdup.c revision 9781:ccf49524d5dc 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
28/* All Rights Reserved */
29
30
31
32#include <limits.h>
33#include <string.h>
34#include <stdlib.h>
35#include <unistd.h>
36#include <errno.h>
37#include <locale.h>
38#include <libintl.h>
39#include <pkglib.h>
40#include <libadm.h>
41
42#define	ERR_MEMORY	"memory allocation failure, errno=%d"
43
44/*
45 * using factor of eight limits maximum
46 * memory fragmentation to 12.5%
47 */
48#define	MEMSIZ	PATH_MAX*8
49#define	NULL	0
50
51struct dup {
52	char	mem[MEMSIZ];
53	struct dup *next;
54};
55
56static struct dup *head, *tail, *new;
57
58static int	size, initialized;
59static void	pathinit();
60static void	growstore();
61
62/*
63 * These functions allocate space for all the path names required
64 * in the packaging code. They are all allocated here so as to reduce
65 * memory fragmentation.
66 */
67
68/* Initialize storage area. */
69static void
70pathinit()
71{
72	if (head == NULL)
73		size = (-1);
74	else {
75		/* free all memory used except initial structure */
76		tail = head->next;
77		while (tail) {
78			new = tail->next;
79			free(tail);
80			tail = new;
81		}
82		tail = head;
83		size = MEMSIZ;
84	}
85
86	initialized = 1;
87}
88
89/* Allocate additional space for storage area. */
90static void
91growstore()
92{
93	/* need more memory */
94	new = calloc(1, sizeof (struct dup));
95	if (new == NULL) {
96		progerr(gettext(ERR_MEMORY), errno);
97		quit(99);
98	}
99	if (head == NULL)
100		head = new;
101	else
102		tail->next = new;
103	tail = new;
104	size = MEMSIZ;
105}
106
107/* Allocate and return a pointer. If n == 0, initialize. */
108char *
109pathalloc(int n)
110{
111	char	*pt;
112
113	if (n <= 0) {
114		pathinit();
115		pt = NULL;
116	} else {
117		if (!initialized)
118			pathinit();
119
120		n++;	/* Account for terminating null. */
121
122		if (size < n)
123			growstore();
124
125		pt = &tail->mem[MEMSIZ-size];
126		size -= n;
127	}
128
129	return (pt);
130}
131
132/* Allocate and insert a pathname returning a pointer to the new string. */
133char *
134pathdup(char *s)
135{
136	char	*pt;
137	int	n;
138
139	if (s == NULL) {
140		pathinit();
141		pt = NULL;
142	} else {
143		if (!initialized)
144			pathinit();
145
146		n = strlen(s) + 1;	/* string + null terminator */
147
148		if (size < n)
149			growstore();
150
151		pt = &tail->mem[MEMSIZ-size];
152		size -= n;
153
154		(void) strcpy(pt, s);
155	}
156
157	return (pt);
158}
159