1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2009 David Schultz <[email protected]>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include "namespace.h"
33 #include <sys/param.h>
34 #include <errno.h>
35 #include <limits.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include "un-namespace.h"
40
41 #include "libc_private.h"
42 #include "local.h"
43
44 static inline size_t
p2roundup(size_t n)45 p2roundup(size_t n)
46 {
47
48 if (!powerof2(n)) {
49 n--;
50 n |= n >> 1;
51 n |= n >> 2;
52 n |= n >> 4;
53 n |= n >> 8;
54 n |= n >> 16;
55 #if SIZE_T_MAX > 0xffffffffU
56 n |= n >> 32;
57 #endif
58 n++;
59 }
60 return (n);
61 }
62
63 /*
64 * Expand *linep to hold len bytes (up to SSIZE_MAX + 1).
65 */
66 static inline int
expandtofit(char ** __restrict linep,size_t len,size_t * __restrict capp)67 expandtofit(char ** __restrict linep, size_t len, size_t * __restrict capp)
68 {
69 char *newline;
70 size_t newcap;
71
72 if (len > (size_t)SSIZE_MAX + 1) {
73 errno = EOVERFLOW;
74 return (-1);
75 }
76 if (len > *capp) {
77 if (len == (size_t)SSIZE_MAX + 1) /* avoid overflow */
78 newcap = (size_t)SSIZE_MAX + 1;
79 else
80 newcap = p2roundup(len);
81 newline = realloc(*linep, newcap);
82 if (newline == NULL)
83 return (-1);
84 *capp = newcap;
85 *linep = newline;
86 }
87 return (0);
88 }
89
90 /*
91 * Append the src buffer to the *dstp buffer. The buffers are of
92 * length srclen and *dstlenp, respectively, and dst has space for
93 * *dstlenp bytes. After the call, *dstlenp and *dstcapp are updated
94 * appropriately, and *dstp is reallocated if needed. Returns 0 on
95 * success, -1 on allocation failure.
96 */
97 static int
sappend(char ** __restrict dstp,size_t * __restrict dstlenp,size_t * __restrict dstcapp,char * __restrict src,size_t srclen)98 sappend(char ** __restrict dstp, size_t * __restrict dstlenp,
99 size_t * __restrict dstcapp, char * __restrict src, size_t srclen)
100 {
101
102 /* ensure room for srclen + dstlen + terminating NUL */
103 if (expandtofit(dstp, srclen + *dstlenp + 1, dstcapp))
104 return (-1);
105 memcpy(*dstp + *dstlenp, src, srclen);
106 *dstlenp += srclen;
107 return (0);
108 }
109
110 ssize_t
getdelim(char ** __restrict linep,size_t * __restrict linecapp,int delim,FILE * __restrict fp)111 getdelim(char ** __restrict linep, size_t * __restrict linecapp, int delim,
112 FILE * __restrict fp)
113 {
114 u_char *endp;
115 size_t linelen;
116
117 FLOCKFILE_CANCELSAFE(fp);
118 ORIENT(fp, -1);
119
120 if (linep == NULL || linecapp == NULL) {
121 errno = EINVAL;
122 goto error;
123 }
124
125 if (*linep == NULL)
126 *linecapp = 0;
127
128 if (fp->_r <= 0 && __srefill(fp)) {
129 /* If fp is at EOF already, we just need space for the NUL. */
130 if (!__sfeof(fp) || expandtofit(linep, 1, linecapp))
131 goto error;
132 (*linep)[0] = '\0';
133 linelen = -1;
134 goto end;
135 }
136
137 linelen = 0;
138 while ((endp = memchr(fp->_p, delim, fp->_r)) == NULL) {
139 if (sappend(linep, &linelen, linecapp, fp->_p, fp->_r))
140 goto error;
141 if (__srefill(fp)) {
142 if (!__sfeof(fp))
143 goto error;
144 goto done; /* hit EOF */
145 }
146 }
147 endp++; /* snarf the delimiter, too */
148 if (sappend(linep, &linelen, linecapp, fp->_p, endp - fp->_p))
149 goto error;
150 fp->_r -= endp - fp->_p;
151 fp->_p = endp;
152 done:
153 /* Invariant: *linep has space for at least linelen+1 bytes. */
154 (*linep)[linelen] = '\0';
155 end:
156 FUNLOCKFILE_CANCELSAFE();
157 return (linelen);
158
159 error:
160 fp->_flags |= __SERR;
161 linelen = -1;
162 goto end;
163 }
164