1 /* $NetBSD: getdelim.c,v 1.14 2017/06/08 15:59:45 uwe Exp $ */
2
3 /*
4 * Copyright (c) 2009 The NetBSD Foundation, Inc.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Roy Marples.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __RCSID("$NetBSD: getdelim.c,v 1.14 2017/06/08 15:59:45 uwe Exp $");
32
33 #include "namespace.h"
34
35 #include <sys/param.h>
36
37 #include <assert.h>
38 #include <errno.h>
39 #include <limits.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43
44 #include "reentrant.h"
45 #include "local.h"
46
47 #ifdef __weak_alias
__weak_alias(getdelim,_getdelim)48 __weak_alias(getdelim, _getdelim)
49 #endif
50
51 /* Minimum buffer size we create.
52 * This should allow config files to fit into our power of 2 buffer growth
53 * without the need for a realloc. */
54 #define MINBUF 128
55
56 ssize_t
57 __getdelim(char **__restrict buf, size_t *__restrict buflen,
58 int sep, FILE *__restrict fp)
59 {
60 unsigned char *p;
61 size_t len, newlen, off;
62 char *newb;
63
64 _DIAGASSERT(fp != NULL);
65
66 if (buf == NULL || buflen == NULL) {
67 errno = EINVAL;
68 goto error;
69 }
70
71 /* If buf is NULL, we have to assume a size of zero */
72 if (*buf == NULL)
73 *buflen = 0;
74
75 _SET_ORIENTATION(fp, -1);
76 off = 0;
77 do {
78 /* If the input buffer is empty, refill it */
79 if (fp->_r <= 0 && __srefill(fp)) {
80 if (__sferror(fp))
81 goto error;
82 /* No error, so EOF. */
83 break;
84 }
85
86 /* Scan through looking for the separator */
87 p = memchr(fp->_p, sep, (size_t)fp->_r);
88 if (p == NULL)
89 len = fp->_r;
90 else
91 len = (p - fp->_p) + 1;
92
93 newlen = off + len;
94 /* Ensure we can handle it */
95 if (newlen < off || newlen > SSIZE_MAX) {
96 errno = EOVERFLOW;
97 goto error;
98 }
99 newlen++; /* reserve space for the null terminator */
100 if (newlen > *buflen) {
101 if (newlen < MINBUF)
102 newlen = MINBUF;
103 if (!powerof2(newlen)) {
104 /* Grow the buffer to the next power of 2 */
105 newlen--;
106 newlen |= newlen >> 1;
107 newlen |= newlen >> 2;
108 newlen |= newlen >> 4;
109 newlen |= newlen >> 8;
110 newlen |= newlen >> 16;
111 #if SIZE_T_MAX > 0xffffffffU
112 newlen |= newlen >> 32;
113 #endif
114 newlen++;
115 }
116
117 newb = realloc(*buf, newlen);
118 if (newb == NULL)
119 goto error;
120 *buf = newb;
121 *buflen = newlen;
122 }
123
124 (void)memcpy((*buf + off), fp->_p, len);
125 /* Safe, len is never greater than what fp->_r can fit. */
126 fp->_r -= (int)len;
127 fp->_p += (int)len;
128 off += len;
129 } while (p == NULL);
130
131 /* POSIX demands we return -1 on EOF. */
132 if (off == 0)
133 return -1;
134
135 if (*buf != NULL)
136 *(*buf + off) = '\0';
137 return off;
138
139 error:
140 fp->_flags |= __SERR;
141 return -1;
142 }
143
144 ssize_t
getdelim(char ** __restrict buf,size_t * __restrict buflen,int sep,FILE * __restrict fp)145 getdelim(char **__restrict buf, size_t *__restrict buflen,
146 int sep, FILE *__restrict fp)
147 {
148 ssize_t n;
149
150 FLOCKFILE(fp);
151 n = __getdelim(buf, buflen, sep, fp);
152 FUNLOCKFILE(fp);
153 return n;
154 }
155