1 /* $OpenBSD: getdelim.c,v 1.1 2012/03/21 23:44:35 fgsch 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 <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36
37 #include "local.h"
38
39 /* Minimum buffer size we create.
40 * This should allow config files to fit into our power of 2 buffer growth
41 * without the need for a realloc. */
42 #define MINBUF 128
43
44 ssize_t
getdelim(char ** __restrict buf,size_t * __restrict buflen,int sep,FILE * __restrict fp)45 getdelim(char **__restrict buf, size_t *__restrict buflen,
46 int sep, FILE *__restrict fp)
47 {
48 unsigned char *p;
49 size_t len, newlen, off;
50 char *newb;
51
52 FLOCKFILE(fp);
53
54 if (buf == NULL || buflen == NULL) {
55 errno = EINVAL;
56 goto error;
57 }
58
59 /* If buf is NULL, we have to assume a size of zero */
60 if (*buf == NULL)
61 *buflen = 0;
62
63 _SET_ORIENTATION(fp, -1);
64 off = 0;
65 do {
66 /* If the input buffer is empty, refill it */
67 if (fp->_r <= 0 && __srefill(fp)) {
68 if (__sferror(fp))
69 goto error;
70 /* No error, so EOF. */
71 break;
72 }
73
74 /* Scan through looking for the separator */
75 p = memchr(fp->_p, sep, (size_t)fp->_r);
76 if (p == NULL)
77 len = fp->_r;
78 else
79 len = (p - fp->_p) + 1;
80
81 newlen = off + len;
82 /* Ensure we can handle it */
83 if (newlen < off || newlen > SSIZE_MAX) {
84 errno = EOVERFLOW;
85 goto error;
86 }
87 newlen++; /* reserve space for the NULL 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_T_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
130 error:
131 fp->_flags |= __SERR;
132 FUNLOCKFILE(fp);
133 return -1;
134 }
135