1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2013 Hudson River Trading LLC
5 * Written by: John H. Baldwin <jhb@FreeBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include "namespace.h"
31 #include <sys/param.h>
32 #include <assert.h>
33 #include <errno.h>
34 #include <limits.h>
35 #include <stdckdint.h>
36 #ifdef DEBUG
37 #include <stdint.h>
38 #endif
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <wchar.h>
43 #include "un-namespace.h"
44
45 /* XXX: There is no FPOS_MAX. This assumes fpos_t is an off_t. */
46 #define FPOS_MAX OFF_MAX
47
48 struct memstream {
49 char **bufp;
50 size_t *sizep;
51 size_t size;
52 ssize_t len;
53 fpos_t offset;
54 };
55
56 static int
memstream_grow(struct memstream * ms,fpos_t newoff)57 memstream_grow(struct memstream *ms, fpos_t newoff)
58 {
59 char *buf;
60 ssize_t newlen;
61
62 if (newoff < 0 || newoff >= SSIZE_MAX)
63 newlen = SSIZE_MAX - 1;
64 else
65 newlen = newoff;
66 if (newlen > ms->size) {
67 size_t newsize;
68
69 if (ckd_add(&newsize, ms->size, ms->size / 2))
70 newsize = SSIZE_MAX - 1;
71
72 newsize = MAX(newsize, newlen);
73
74 buf = realloc(*ms->bufp, newsize + 1);
75 if (buf == NULL)
76 return (0);
77
78 #ifdef DEBUG
79 fprintf(stderr, "MS: %p growing from %zd to %zd\n",
80 ms, ms->size, newsize);
81 #endif
82 memset(buf + ms->size + 1, 0, newsize - ms->size);
83 *ms->bufp = buf;
84 ms->size = newsize;
85 }
86
87 if (newlen > ms->len)
88 ms->len = newlen;
89 return (1);
90 }
91
92 static void
memstream_update(struct memstream * ms)93 memstream_update(struct memstream *ms)
94 {
95
96 assert(ms->len >= 0 && ms->offset >= 0);
97 *ms->sizep = ms->len < ms->offset ? ms->len : ms->offset;
98 }
99
100 static int
memstream_write(void * cookie,const char * buf,int len)101 memstream_write(void *cookie, const char *buf, int len)
102 {
103 struct memstream *ms;
104 ssize_t tocopy;
105
106 ms = cookie;
107 if (!memstream_grow(ms, ms->offset + len))
108 return (-1);
109 tocopy = ms->len - ms->offset;
110 if (len < tocopy)
111 tocopy = len;
112 memcpy(*ms->bufp + ms->offset, buf, tocopy);
113 ms->offset += tocopy;
114 memstream_update(ms);
115 #ifdef DEBUG
116 fprintf(stderr, "MS: write(%p, %d) = %zd\n", ms, len, tocopy);
117 #endif
118 return (tocopy);
119 }
120
121 static fpos_t
memstream_seek(void * cookie,fpos_t pos,int whence)122 memstream_seek(void *cookie, fpos_t pos, int whence)
123 {
124 struct memstream *ms;
125 #ifdef DEBUG
126 fpos_t old;
127 #endif
128
129 ms = cookie;
130 #ifdef DEBUG
131 old = ms->offset;
132 #endif
133 switch (whence) {
134 case SEEK_SET:
135 /* _fseeko() checks for negative offsets. */
136 assert(pos >= 0);
137 ms->offset = pos;
138 break;
139 case SEEK_CUR:
140 /* This is only called by _ftello(). */
141 assert(pos == 0);
142 break;
143 case SEEK_END:
144 if (pos < 0) {
145 if (pos + ms->len < 0) {
146 #ifdef DEBUG
147 fprintf(stderr,
148 "MS: bad SEEK_END: pos %jd, len %zd\n",
149 (intmax_t)pos, ms->len);
150 #endif
151 errno = EINVAL;
152 return (-1);
153 }
154 } else {
155 if (FPOS_MAX - ms->len < pos) {
156 #ifdef DEBUG
157 fprintf(stderr,
158 "MS: bad SEEK_END: pos %jd, len %zd\n",
159 (intmax_t)pos, ms->len);
160 #endif
161 errno = EOVERFLOW;
162 return (-1);
163 }
164 }
165 ms->offset = ms->len + pos;
166 break;
167 }
168 memstream_update(ms);
169 #ifdef DEBUG
170 fprintf(stderr, "MS: seek(%p, %jd, %d) %jd -> %jd\n", ms, (intmax_t)pos,
171 whence, (intmax_t)old, (intmax_t)ms->offset);
172 #endif
173 return (ms->offset);
174 }
175
176 static int
memstream_close(void * cookie)177 memstream_close(void *cookie)
178 {
179
180 free(cookie);
181 return (0);
182 }
183
184 FILE *
open_memstream(char ** bufp,size_t * sizep)185 open_memstream(char **bufp, size_t *sizep)
186 {
187 struct memstream *ms;
188 int save_errno;
189 FILE *fp;
190
191 if (bufp == NULL || sizep == NULL) {
192 errno = EINVAL;
193 return (NULL);
194 }
195 *bufp = calloc(1, 1);
196 if (*bufp == NULL)
197 return (NULL);
198 ms = malloc(sizeof(*ms));
199 if (ms == NULL) {
200 save_errno = errno;
201 free(*bufp);
202 *bufp = NULL;
203 errno = save_errno;
204 return (NULL);
205 }
206 ms->bufp = bufp;
207 ms->sizep = sizep;
208 ms->size = 0;
209 ms->len = 0;
210 ms->offset = 0;
211 memstream_update(ms);
212 fp = funopen(ms, NULL, memstream_write, memstream_seek,
213 memstream_close);
214 if (fp == NULL) {
215 save_errno = errno;
216 free(ms);
217 free(*bufp);
218 *bufp = NULL;
219 errno = save_errno;
220 return (NULL);
221 }
222 fwide(fp, -1);
223 return (fp);
224 }
225