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1 74b37681 2019-02-07 stsp /* $OpenBSD: buf.c,v 1.27 2016/10/16 13:35:51 okan Exp $ */
2 74b37681 2019-02-07 stsp /*
3 74b37681 2019-02-07 stsp * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
4 74b37681 2019-02-07 stsp * All rights reserved.
5 74b37681 2019-02-07 stsp *
6 74b37681 2019-02-07 stsp * Redistribution and use in source and binary forms, with or without
7 74b37681 2019-02-07 stsp * modification, are permitted provided that the following conditions
8 74b37681 2019-02-07 stsp * are met:
9 74b37681 2019-02-07 stsp *
10 74b37681 2019-02-07 stsp * 1. Redistributions of source code must retain the above copyright
11 74b37681 2019-02-07 stsp * notice, this list of conditions and the following disclaimer.
12 74b37681 2019-02-07 stsp * 2. The name of the author may not be used to endorse or promote products
13 74b37681 2019-02-07 stsp * derived from this software without specific prior written permission.
14 74b37681 2019-02-07 stsp *
15 74b37681 2019-02-07 stsp * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16 74b37681 2019-02-07 stsp * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17 74b37681 2019-02-07 stsp * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18 74b37681 2019-02-07 stsp * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 74b37681 2019-02-07 stsp * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 74b37681 2019-02-07 stsp * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21 74b37681 2019-02-07 stsp * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 74b37681 2019-02-07 stsp * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23 74b37681 2019-02-07 stsp * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24 74b37681 2019-02-07 stsp * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 74b37681 2019-02-07 stsp */
26 74b37681 2019-02-07 stsp
27 74b37681 2019-02-07 stsp #include <sys/queue.h>
28 74b37681 2019-02-07 stsp #include <sys/stat.h>
29 74b37681 2019-02-07 stsp
30 74b37681 2019-02-07 stsp #include <errno.h>
31 74b37681 2019-02-07 stsp #include <fcntl.h>
32 74b37681 2019-02-07 stsp #include <stdint.h>
33 74b37681 2019-02-07 stsp #include <stdio.h>
34 74b37681 2019-02-07 stsp #include <stdlib.h>
35 74b37681 2019-02-07 stsp #include <string.h>
36 74b37681 2019-02-07 stsp #include <unistd.h>
37 74b37681 2019-02-07 stsp
38 74b37681 2019-02-07 stsp #include "buf.h"
39 74b37681 2019-02-07 stsp #include "worklist.h"
40 74b37681 2019-02-07 stsp
41 af45e626 2019-02-08 stsp #include "got_error.h"
42 af45e626 2019-02-08 stsp
43 74b37681 2019-02-07 stsp #define BUF_INCR 128
44 74b37681 2019-02-07 stsp
45 74b37681 2019-02-07 stsp struct buf {
46 74b37681 2019-02-07 stsp /* buffer handle, buffer size, and data length */
47 74b37681 2019-02-07 stsp u_char *cb_buf;
48 74b37681 2019-02-07 stsp size_t cb_size;
49 74b37681 2019-02-07 stsp size_t cb_len;
50 74b37681 2019-02-07 stsp };
51 74b37681 2019-02-07 stsp
52 74b37681 2019-02-07 stsp #define SIZE_LEFT(b) (b->cb_size - b->cb_len)
53 74b37681 2019-02-07 stsp
54 af45e626 2019-02-08 stsp static const struct got_error *buf_grow(BUF *, size_t);
55 74b37681 2019-02-07 stsp
56 74b37681 2019-02-07 stsp /*
57 74b37681 2019-02-07 stsp * Create a new buffer structure and return a pointer to it. This structure
58 74b37681 2019-02-07 stsp * uses dynamically-allocated memory and must be freed with buf_free(), once
59 74b37681 2019-02-07 stsp * the buffer is no longer needed.
60 74b37681 2019-02-07 stsp */
61 74b37681 2019-02-07 stsp BUF *
62 74b37681 2019-02-07 stsp buf_alloc(size_t len)
63 74b37681 2019-02-07 stsp {
64 74b37681 2019-02-07 stsp BUF *b;
65 74b37681 2019-02-07 stsp
66 af45e626 2019-02-08 stsp b = malloc(sizeof(*b));
67 af45e626 2019-02-08 stsp if (b == NULL)
68 af45e626 2019-02-08 stsp return NULL;
69 74b37681 2019-02-07 stsp /* Postpone creation of zero-sized buffers */
70 af45e626 2019-02-08 stsp if (len > 0) {
71 af45e626 2019-02-08 stsp b->cb_buf = calloc(1, len);
72 57ebf19f 2019-08-28 hiltjo if (b->cb_buf == NULL) {
73 57ebf19f 2019-08-28 hiltjo free(b);
74 af45e626 2019-02-08 stsp return NULL;
75 57ebf19f 2019-08-28 hiltjo }
76 af45e626 2019-02-08 stsp } else
77 74b37681 2019-02-07 stsp b->cb_buf = NULL;
78 74b37681 2019-02-07 stsp
79 74b37681 2019-02-07 stsp b->cb_size = len;
80 74b37681 2019-02-07 stsp b->cb_len = 0;
81 74b37681 2019-02-07 stsp
82 74b37681 2019-02-07 stsp return (b);
83 74b37681 2019-02-07 stsp }
84 74b37681 2019-02-07 stsp
85 74b37681 2019-02-07 stsp /*
86 74b37681 2019-02-07 stsp * Open the file specified by <path> and load all of its contents into a
87 74b37681 2019-02-07 stsp * buffer.
88 74b37681 2019-02-07 stsp * Returns the loaded buffer on success or NULL on failure.
89 74b37681 2019-02-07 stsp * Sets errno on error.
90 74b37681 2019-02-07 stsp */
91 74b37681 2019-02-07 stsp BUF *
92 74b37681 2019-02-07 stsp buf_load(const char *path)
93 74b37681 2019-02-07 stsp {
94 74b37681 2019-02-07 stsp int fd;
95 74b37681 2019-02-07 stsp ssize_t ret;
96 74b37681 2019-02-07 stsp size_t len;
97 74b37681 2019-02-07 stsp u_char *bp;
98 74b37681 2019-02-07 stsp struct stat st;
99 74b37681 2019-02-07 stsp BUF *buf;
100 74b37681 2019-02-07 stsp
101 74b37681 2019-02-07 stsp buf = NULL;
102 74b37681 2019-02-07 stsp
103 74b37681 2019-02-07 stsp if ((fd = open(path, O_RDONLY, 0600)) == -1)
104 74b37681 2019-02-07 stsp goto out;
105 74b37681 2019-02-07 stsp
106 74b37681 2019-02-07 stsp if (fstat(fd, &st) == -1)
107 74b37681 2019-02-07 stsp goto out;
108 74b37681 2019-02-07 stsp
109 74b37681 2019-02-07 stsp if ((uintmax_t)st.st_size > SIZE_MAX) {
110 74b37681 2019-02-07 stsp errno = EFBIG;
111 74b37681 2019-02-07 stsp goto out;
112 74b37681 2019-02-07 stsp }
113 74b37681 2019-02-07 stsp buf = buf_alloc(st.st_size);
114 74b37681 2019-02-07 stsp for (bp = buf->cb_buf; ; bp += (size_t)ret) {
115 74b37681 2019-02-07 stsp len = SIZE_LEFT(buf);
116 74b37681 2019-02-07 stsp ret = read(fd, bp, len);
117 74b37681 2019-02-07 stsp if (ret == -1) {
118 74b37681 2019-02-07 stsp int saved_errno;
119 74b37681 2019-02-07 stsp
120 74b37681 2019-02-07 stsp saved_errno = errno;
121 74b37681 2019-02-07 stsp buf_free(buf);
122 74b37681 2019-02-07 stsp buf = NULL;
123 74b37681 2019-02-07 stsp errno = saved_errno;
124 74b37681 2019-02-07 stsp goto out;
125 74b37681 2019-02-07 stsp } else if (ret == 0)
126 74b37681 2019-02-07 stsp break;
127 74b37681 2019-02-07 stsp
128 74b37681 2019-02-07 stsp buf->cb_len += (size_t)ret;
129 74b37681 2019-02-07 stsp }
130 74b37681 2019-02-07 stsp
131 74b37681 2019-02-07 stsp out:
132 74b37681 2019-02-07 stsp if (fd != -1) {
133 74b37681 2019-02-07 stsp int saved_errno;
134 74b37681 2019-02-07 stsp
135 74b37681 2019-02-07 stsp /* We may want to preserve errno here. */
136 74b37681 2019-02-07 stsp saved_errno = errno;
137 74b37681 2019-02-07 stsp (void)close(fd);
138 74b37681 2019-02-07 stsp errno = saved_errno;
139 74b37681 2019-02-07 stsp }
140 74b37681 2019-02-07 stsp
141 74b37681 2019-02-07 stsp return (buf);
142 74b37681 2019-02-07 stsp }
143 74b37681 2019-02-07 stsp
144 74b37681 2019-02-07 stsp void
145 74b37681 2019-02-07 stsp buf_free(BUF *b)
146 74b37681 2019-02-07 stsp {
147 74b37681 2019-02-07 stsp if (b == NULL)
148 74b37681 2019-02-07 stsp return;
149 74b37681 2019-02-07 stsp free(b->cb_buf);
150 74b37681 2019-02-07 stsp free(b);
151 74b37681 2019-02-07 stsp }
152 74b37681 2019-02-07 stsp
153 74b37681 2019-02-07 stsp /*
154 74b37681 2019-02-07 stsp * Free the buffer <b>'s structural information but do not free the contents
155 74b37681 2019-02-07 stsp * of the buffer. Instead, they are returned and should be freed later using
156 74b37681 2019-02-07 stsp * free().
157 74b37681 2019-02-07 stsp */
158 74b37681 2019-02-07 stsp void *
159 74b37681 2019-02-07 stsp buf_release(BUF *b)
160 74b37681 2019-02-07 stsp {
161 74b37681 2019-02-07 stsp void *tmp;
162 74b37681 2019-02-07 stsp
163 74b37681 2019-02-07 stsp tmp = b->cb_buf;
164 74b37681 2019-02-07 stsp free(b);
165 74b37681 2019-02-07 stsp return (tmp);
166 74b37681 2019-02-07 stsp }
167 74b37681 2019-02-07 stsp
168 74b37681 2019-02-07 stsp u_char *
169 74b37681 2019-02-07 stsp buf_get(BUF *b)
170 74b37681 2019-02-07 stsp {
171 74b37681 2019-02-07 stsp return (b->cb_buf);
172 74b37681 2019-02-07 stsp }
173 74b37681 2019-02-07 stsp
174 74b37681 2019-02-07 stsp /*
175 74b37681 2019-02-07 stsp * Empty the contents of the buffer <b> and reset pointers.
176 74b37681 2019-02-07 stsp */
177 74b37681 2019-02-07 stsp void
178 74b37681 2019-02-07 stsp buf_empty(BUF *b)
179 74b37681 2019-02-07 stsp {
180 74b37681 2019-02-07 stsp memset(b->cb_buf, 0, b->cb_size);
181 74b37681 2019-02-07 stsp b->cb_len = 0;
182 74b37681 2019-02-07 stsp }
183 74b37681 2019-02-07 stsp
184 74b37681 2019-02-07 stsp /*
185 74b37681 2019-02-07 stsp * Append a single character <c> to the end of the buffer <b>.
186 74b37681 2019-02-07 stsp */
187 af45e626 2019-02-08 stsp const struct got_error *
188 74b37681 2019-02-07 stsp buf_putc(BUF *b, int c)
189 74b37681 2019-02-07 stsp {
190 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
191 74b37681 2019-02-07 stsp u_char *bp;
192 74b37681 2019-02-07 stsp
193 af45e626 2019-02-08 stsp if (SIZE_LEFT(b) == 0) {
194 af45e626 2019-02-08 stsp err = buf_grow(b, BUF_INCR);
195 af45e626 2019-02-08 stsp if (err)
196 af45e626 2019-02-08 stsp return err;
197 af45e626 2019-02-08 stsp }
198 74b37681 2019-02-07 stsp bp = b->cb_buf + b->cb_len;
199 74b37681 2019-02-07 stsp *bp = (u_char)c;
200 74b37681 2019-02-07 stsp b->cb_len++;
201 af45e626 2019-02-08 stsp return NULL;
202 74b37681 2019-02-07 stsp }
203 74b37681 2019-02-07 stsp
204 74b37681 2019-02-07 stsp /*
205 74b37681 2019-02-07 stsp * Append a string <s> to the end of buffer <b>.
206 74b37681 2019-02-07 stsp */
207 af45e626 2019-02-08 stsp const struct got_error *
208 af45e626 2019-02-08 stsp buf_puts(size_t *newlen, BUF *b, const char *str)
209 74b37681 2019-02-07 stsp {
210 af45e626 2019-02-08 stsp return buf_append(newlen, b, str, strlen(str));
211 74b37681 2019-02-07 stsp }
212 74b37681 2019-02-07 stsp
213 74b37681 2019-02-07 stsp /*
214 74b37681 2019-02-07 stsp * Return u_char at buffer position <pos>.
215 74b37681 2019-02-07 stsp */
216 74b37681 2019-02-07 stsp u_char
217 74b37681 2019-02-07 stsp buf_getc(BUF *b, size_t pos)
218 74b37681 2019-02-07 stsp {
219 74b37681 2019-02-07 stsp return (b->cb_buf[pos]);
220 74b37681 2019-02-07 stsp }
221 74b37681 2019-02-07 stsp
222 74b37681 2019-02-07 stsp /*
223 74b37681 2019-02-07 stsp * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
224 74b37681 2019-02-07 stsp * buffer is too small to accept all data, it will get resized to an
225 74b37681 2019-02-07 stsp * appropriate size to accept all data.
226 74b37681 2019-02-07 stsp * Returns the number of bytes successfully appended to the buffer.
227 74b37681 2019-02-07 stsp */
228 af45e626 2019-02-08 stsp const struct got_error *
229 af45e626 2019-02-08 stsp buf_append(size_t *newlen, BUF *b, const void *data, size_t len)
230 74b37681 2019-02-07 stsp {
231 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
232 74b37681 2019-02-07 stsp size_t left, rlen;
233 74b37681 2019-02-07 stsp u_char *bp;
234 74b37681 2019-02-07 stsp
235 74b37681 2019-02-07 stsp left = SIZE_LEFT(b);
236 74b37681 2019-02-07 stsp rlen = len;
237 74b37681 2019-02-07 stsp
238 af45e626 2019-02-08 stsp if (left < len) {
239 af45e626 2019-02-08 stsp err = buf_grow(b, len - left);
240 af45e626 2019-02-08 stsp if (err)
241 af45e626 2019-02-08 stsp return err;
242 af45e626 2019-02-08 stsp }
243 74b37681 2019-02-07 stsp bp = b->cb_buf + b->cb_len;
244 74b37681 2019-02-07 stsp memcpy(bp, data, rlen);
245 74b37681 2019-02-07 stsp b->cb_len += rlen;
246 74b37681 2019-02-07 stsp
247 af45e626 2019-02-08 stsp *newlen = rlen;
248 af45e626 2019-02-08 stsp return NULL;
249 74b37681 2019-02-07 stsp }
250 74b37681 2019-02-07 stsp
251 74b37681 2019-02-07 stsp /*
252 74b37681 2019-02-07 stsp * Returns the size of the buffer that is being used.
253 74b37681 2019-02-07 stsp */
254 74b37681 2019-02-07 stsp size_t
255 74b37681 2019-02-07 stsp buf_len(BUF *b)
256 74b37681 2019-02-07 stsp {
257 74b37681 2019-02-07 stsp return (b->cb_len);
258 74b37681 2019-02-07 stsp }
259 74b37681 2019-02-07 stsp
260 74b37681 2019-02-07 stsp /*
261 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to the specified <fd>
262 74b37681 2019-02-07 stsp */
263 74b37681 2019-02-07 stsp int
264 74b37681 2019-02-07 stsp buf_write_fd(BUF *b, int fd)
265 74b37681 2019-02-07 stsp {
266 74b37681 2019-02-07 stsp u_char *bp;
267 74b37681 2019-02-07 stsp size_t len;
268 74b37681 2019-02-07 stsp ssize_t ret;
269 74b37681 2019-02-07 stsp
270 74b37681 2019-02-07 stsp len = b->cb_len;
271 74b37681 2019-02-07 stsp bp = b->cb_buf;
272 74b37681 2019-02-07 stsp
273 74b37681 2019-02-07 stsp do {
274 74b37681 2019-02-07 stsp ret = write(fd, bp, len);
275 74b37681 2019-02-07 stsp if (ret == -1) {
276 74b37681 2019-02-07 stsp if (errno == EINTR || errno == EAGAIN)
277 74b37681 2019-02-07 stsp continue;
278 74b37681 2019-02-07 stsp return (-1);
279 74b37681 2019-02-07 stsp }
280 74b37681 2019-02-07 stsp
281 74b37681 2019-02-07 stsp len -= (size_t)ret;
282 74b37681 2019-02-07 stsp bp += (size_t)ret;
283 74b37681 2019-02-07 stsp } while (len > 0);
284 74b37681 2019-02-07 stsp
285 74b37681 2019-02-07 stsp return (0);
286 74b37681 2019-02-07 stsp }
287 74b37681 2019-02-07 stsp
288 74b37681 2019-02-07 stsp /*
289 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to the file whose path is given in
290 74b37681 2019-02-07 stsp * <path>. If the file does not exist, it is created with mode <mode>.
291 74b37681 2019-02-07 stsp */
292 af45e626 2019-02-08 stsp const struct got_error *
293 74b37681 2019-02-07 stsp buf_write(BUF *b, const char *path, mode_t mode)
294 74b37681 2019-02-07 stsp {
295 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
296 74b37681 2019-02-07 stsp int fd;
297 74b37681 2019-02-07 stsp open:
298 74b37681 2019-02-07 stsp if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
299 202329ae 2019-08-11 stsp err = got_error_from_errno2("open", path);
300 74b37681 2019-02-07 stsp if (errno == EACCES && unlink(path) != -1)
301 74b37681 2019-02-07 stsp goto open;
302 74b37681 2019-02-07 stsp else
303 202329ae 2019-08-11 stsp return err;
304 74b37681 2019-02-07 stsp }
305 74b37681 2019-02-07 stsp
306 74b37681 2019-02-07 stsp if (buf_write_fd(b, fd) == -1) {
307 638f9024 2019-05-13 stsp err = got_error_from_errno("buf_write_fd");
308 74b37681 2019-02-07 stsp (void)unlink(path);
309 af45e626 2019-02-08 stsp return err;
310 74b37681 2019-02-07 stsp }
311 74b37681 2019-02-07 stsp
312 74b37681 2019-02-07 stsp if (fchmod(fd, mode) < 0)
313 638f9024 2019-05-13 stsp err = got_error_from_errno2("fchmod", path);
314 74b37681 2019-02-07 stsp
315 3a6ce05a 2019-02-11 stsp if (close(fd) != 0 && err == NULL)
316 638f9024 2019-05-13 stsp err = got_error_from_errno2("close", path);
317 74b37681 2019-02-07 stsp
318 af45e626 2019-02-08 stsp return err;
319 74b37681 2019-02-07 stsp }
320 74b37681 2019-02-07 stsp
321 74b37681 2019-02-07 stsp /*
322 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to a temporary file whose path is
323 74b37681 2019-02-07 stsp * specified using <template> (see mkstemp.3).
324 74b37681 2019-02-07 stsp * NB. This function will modify <template>, as per mkstemp
325 74b37681 2019-02-07 stsp */
326 af45e626 2019-02-08 stsp const struct got_error *
327 af45e626 2019-02-08 stsp buf_write_stmp(BUF *b, char *template, struct wklhead *temp_files)
328 74b37681 2019-02-07 stsp {
329 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
330 74b37681 2019-02-07 stsp int fd;
331 74b37681 2019-02-07 stsp
332 74b37681 2019-02-07 stsp if ((fd = mkstemp(template)) == -1)
333 638f9024 2019-05-13 stsp return got_error_from_errno("mkstemp");
334 74b37681 2019-02-07 stsp
335 af45e626 2019-02-08 stsp worklist_add(template, temp_files);
336 74b37681 2019-02-07 stsp
337 74b37681 2019-02-07 stsp if (buf_write_fd(b, fd) == -1) {
338 638f9024 2019-05-13 stsp err = got_error_from_errno("buf_write_fd");
339 74b37681 2019-02-07 stsp (void)unlink(template);
340 74b37681 2019-02-07 stsp }
341 74b37681 2019-02-07 stsp
342 3a6ce05a 2019-02-11 stsp if (close(fd) != 0 && err == NULL)
343 638f9024 2019-05-13 stsp err = got_error_from_errno("close");
344 3a6ce05a 2019-02-11 stsp
345 af45e626 2019-02-08 stsp return err;
346 74b37681 2019-02-07 stsp }
347 74b37681 2019-02-07 stsp
348 74b37681 2019-02-07 stsp /*
349 74b37681 2019-02-07 stsp * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
350 74b37681 2019-02-07 stsp * operation regardless of the result.
351 74b37681 2019-02-07 stsp */
352 af45e626 2019-02-08 stsp static const struct got_error *
353 74b37681 2019-02-07 stsp buf_grow(BUF *b, size_t len)
354 74b37681 2019-02-07 stsp {
355 af45e626 2019-02-08 stsp u_char *buf;
356 af45e626 2019-02-08 stsp buf = reallocarray(b->cb_buf, 1, b->cb_size + len);
357 af45e626 2019-02-08 stsp if (buf == NULL)
358 638f9024 2019-05-13 stsp return got_error_from_errno("reallocarray");
359 af45e626 2019-02-08 stsp b->cb_buf = buf;
360 74b37681 2019-02-07 stsp b->cb_size += len;
361 af45e626 2019-02-08 stsp return NULL;
362 74b37681 2019-02-07 stsp }