[go: nahoru, domu]
1/*	$OpenBSD: getdelim.c,v 1.4 2015/08/31 02:53:57 guenther Exp $	*/
2/* $NetBSD: getdelim.c,v 1.13 2011/07/22 23:12:30 joerg Exp $ */
3
4/*
5 * Copyright (c) 2009 The NetBSD Foundation, Inc.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Roy Marples.
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 AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <errno.h>
32#include <limits.h>
33#include <stdint.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37
38#include "local.h"
39
40/* Minimum buffer size we create.
41 * This should allow config files to fit into our power of 2 buffer growth
42 * without the need for a realloc. */
43#define MINBUF	128
44
45ssize_t
46getdelim(char **__restrict buf, size_t *__restrict buflen,
47    int sep, FILE *__restrict fp)
48{
49	unsigned char *p;
50	size_t len, newlen, off;
51	char *newb;
52
53	FLOCKFILE(fp);
54
55	if (buf == NULL || buflen == NULL) {
56		errno = EINVAL;
57		goto error;
58	}
59
60	/* If buf is NULL, we have to assume a size of zero */
61	if (*buf == NULL)
62		*buflen = 0;
63
64	_SET_ORIENTATION(fp, -1);
65	off = 0;
66	do {
67		/* If the input buffer is empty, refill it */
68		if (fp->_r <= 0 && __srefill(fp)) {
69			if (__sferror(fp))
70				goto error;
71			/* No error, so EOF. */
72			break;
73		}
74
75		/* Scan through looking for the separator */
76		p = memchr(fp->_p, sep, (size_t)fp->_r);
77		if (p == NULL)
78			len = fp->_r;
79		else
80			len = (p - fp->_p) + 1;
81
82		/* Ensure we can handle it */
83		if (off > SSIZE_MAX || len + 1 > SSIZE_MAX - off) {
84			errno = EOVERFLOW;
85			goto error;
86		}
87		newlen = off + len + 1; /* reserve space for NUL terminator */
88		if (newlen > *buflen) {
89			if (newlen < MINBUF)
90				newlen = MINBUF;
91#define powerof2(x) ((((x)-1)&(x))==0)
92			if (!powerof2(newlen)) {
93				/* Grow the buffer to the next power of 2 */
94				newlen--;
95				newlen |= newlen >> 1;
96				newlen |= newlen >> 2;
97				newlen |= newlen >> 4;
98				newlen |= newlen >> 8;
99				newlen |= newlen >> 16;
100#if SIZE_MAX > 0xffffffffU
101				newlen |= newlen >> 32;
102#endif
103				newlen++;
104			}
105
106			newb = realloc(*buf, newlen);
107			if (newb == NULL)
108				goto error;
109			*buf = newb;
110			*buflen = newlen;
111		}
112
113		(void)memcpy((*buf + off), fp->_p, len);
114		/* Safe, len is never greater than what fp->_r can fit. */
115		fp->_r -= (int)len;
116		fp->_p += (int)len;
117		off += len;
118	} while (p == NULL);
119
120	FUNLOCKFILE(fp);
121
122	/* POSIX demands we return -1 on EOF. */
123	if (off == 0)
124		return -1;
125
126	if (*buf != NULL)
127		*(*buf + off) = '\0';
128	return off;
129
130error:
131	fp->_flags |= __SERR;
132	FUNLOCKFILE(fp);
133	return -1;
134}
135DEF_WEAK(getdelim);
136