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1/*-
2 * Copyright (c) 2013 Hudson River Trading LLC
3 * Written by: John H. Baldwin <jhb@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31#include <assert.h>
32#include <errno.h>
33#include <limits.h>
34#ifdef DEBUG
35#include <stdint.h>
36#endif
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include <wchar.h>
41
42#include <malloc_private.h>
43
44/* XXX: There is no FPOS_MAX. This assumes fpos_t is an off_t. */
45#define FPOS_MAX OFF_MAX
46
47struct wmemstream {
48 wchar_t **bufp;
49 size_t *sizep;
50 ssize_t len;
51 fpos_t offset;
52 mbstate_t mbstate;
53};
54
55static int
56wmemstream_grow(struct wmemstream *ms, fpos_t newoff)
57{
58 wchar_t *buf;
59 ssize_t newsize;
60
61 if (newoff < 0 || newoff >= SSIZE_MAX / sizeof(wchar_t))
62 newsize = SSIZE_MAX / sizeof(wchar_t) - 1;
63 else
64 newsize = newoff;
65 if (newsize > ms->len) {
66 buf = reallocarray(*ms->bufp, newsize + 1, sizeof(wchar_t));
67 if (buf != NULL) {
68#ifdef DEBUG
69 fprintf(stderr, "WMS: %p growing from %zd to %zd\n",
70 ms, ms->len, newsize);
71#endif
72 wmemset(buf + ms->len + 1, 0, newsize - ms->len);
73 *ms->bufp = buf;
74 ms->len = newsize;
75 return (1);
76 }
77 return (0);
78 }
79 return (1);
80}
81
82static void
83wmemstream_update(struct wmemstream *ms)
84{
85
86 assert(ms->len >= 0 && ms->offset >= 0);
87 *ms->sizep = ms->len < ms->offset ? ms->len : ms->offset;
88}
89
90/*
91 * Based on a starting multibyte state and an input buffer, determine
92 * how many wchar_t's would be output. This doesn't use mbsnrtowcs()
93 * so that it can handle embedded null characters.
94 */
95static size_t
96wbuflen(const mbstate_t *state, const char *buf, int len)
97{
98 mbstate_t lenstate;
99 size_t charlen, count;
100
101 count = 0;
102 lenstate = *state;
103 while (len > 0) {
104 charlen = mbrlen(buf, len, &lenstate);
105 if (charlen == (size_t)-1)
106 return (-1);
107 if (charlen == (size_t)-2)
108 break;
109 if (charlen == 0)
110 /* XXX: Not sure how else to handle this. */
111 charlen = 1;
112 len -= charlen;
113 buf += charlen;
114 count++;
115 }
116 return (count);
117}
118
119static int
120wmemstream_write(void *cookie, const char *buf, int len)
121{
122 struct wmemstream *ms;
123 ssize_t consumed, wlen;
124 size_t charlen;
125
126 ms = cookie;
127 wlen = wbuflen(&ms->mbstate, buf, len);
128 if (wlen < 0) {
129 errno = EILSEQ;
130 return (-1);
131 }
132 if (!wmemstream_grow(ms, ms->offset + wlen))
133 return (-1);
134
135 /*
136 * This copies characters one at a time rather than using
137 * mbsnrtowcs() so it can properly handle embedded null
138 * characters.
139 */
140 consumed = 0;
141 while (len > 0 && ms->offset < ms->len) {
142 charlen = mbrtowc(*ms->bufp + ms->offset, buf, len,
143 &ms->mbstate);
144 if (charlen == (size_t)-1) {
145 if (consumed == 0) {
146 errno = EILSEQ;
147 return (-1);
148 }
149 /* Treat it as a successful short write. */
150 break;
151 }
152 if (charlen == 0)
153 /* XXX: Not sure how else to handle this. */
154 charlen = 1;
155 if (charlen == (size_t)-2) {
156 consumed += len;
157 len = 0;
158 } else {
159 consumed += charlen;
160 buf += charlen;
161 len -= charlen;
162 ms->offset++;
163 }
164 }
165 wmemstream_update(ms);
166#ifdef DEBUG
167 fprintf(stderr, "WMS: write(%p, %d) = %zd\n", ms, len, consumed);
168#endif
169 return (consumed);
170}
171
172static fpos_t
173wmemstream_seek(void *cookie, fpos_t pos, int whence)
174{
175 struct wmemstream *ms;
176 fpos_t old;
177
178 ms = cookie;
179 old = ms->offset;
180 switch (whence) {
181 case SEEK_SET:
182 /* _fseeko() checks for negative offsets. */
183 assert(pos >= 0);
184 ms->offset = pos;
185 break;
186 case SEEK_CUR:
187 /* This is only called by _ftello(). */
188 assert(pos == 0);
189 break;
190 case SEEK_END:
191 if (pos < 0) {
192 if (pos + ms->len < 0) {
193#ifdef DEBUG
194 fprintf(stderr,
195 "WMS: bad SEEK_END: pos %jd, len %zd\n",
196 (intmax_t)pos, ms->len);
197#endif
198 errno = EINVAL;
199 return (-1);
200 }
201 } else {
202 if (FPOS_MAX - ms->len < pos) {
203#ifdef DEBUG
204 fprintf(stderr,
205 "WMS: bad SEEK_END: pos %jd, len %zd\n",
206 (intmax_t)pos, ms->len);
207#endif
208 errno = EOVERFLOW;
209 return (-1);
210 }
211 }
212 ms->offset = ms->len + pos;
213 break;
214 }
215 /* Reset the multibyte state if a seek changes the position. */
216 if (ms->offset != old)
217 memset(&ms->mbstate, 0, sizeof(ms->mbstate));
218 wmemstream_update(ms);
219#ifdef DEBUG
220 fprintf(stderr, "WMS: seek(%p, %jd, %d) %jd -> %jd\n", ms,
221 (intmax_t)pos, whence, (intmax_t)old, (intmax_t)ms->offset);
222#endif
223 return (ms->offset);
224}
225
226static int
227wmemstream_close(void *cookie)
228{
229
230 free(cookie);
231 return (0);
232}
233
234FILE *
235open_wmemstream(wchar_t **bufp, size_t *sizep)
236{
237 struct wmemstream *ms;
238 int save_errno;
239 FILE *fp;
240
241 if (bufp == NULL || sizep == NULL) {
242 errno = EINVAL;
243 return (NULL);
244 }
245 *bufp = calloc(1, sizeof(wchar_t));
246 if (*bufp == NULL)
247 return (NULL);
248 ms = malloc(sizeof(*ms));
249 if (ms == NULL) {
250 save_errno = errno;
251 free(*bufp);
252 *bufp = NULL;
253 errno = save_errno;
254 return (NULL);
255 }
256 ms->bufp = bufp;
257 ms->sizep = sizep;
258 ms->len = 0;
259 ms->offset = 0;
260 memset(&ms->mbstate, 0, sizeof(mbstate_t));
261 wmemstream_update(ms);
262 fp = funopen(ms, NULL, wmemstream_write, wmemstream_seek,
263 wmemstream_close);
264 if (fp == NULL) {
265 save_errno = errno;
266 free(ms);
267 free(*bufp);
268 *bufp = NULL;
269 errno = save_errno;
270 return (NULL);
271 }
272 fwide(fp, 1);
273 return (fp);
274}