1 74b37681 2019-02-07 stsp /* $OpenBSD: buf.c,v 1.27 2016/10/16 13:35:51 okan Exp $ */
3 74b37681 2019-02-07 stsp * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
4 74b37681 2019-02-07 stsp * All rights reserved.
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
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.
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.
27 74b37681 2019-02-07 stsp #include <sys/queue.h>
28 74b37681 2019-02-07 stsp #include <sys/stat.h>
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>
38 74b37681 2019-02-07 stsp #include "buf.h"
39 74b37681 2019-02-07 stsp #include "worklist.h"
41 af45e626 2019-02-08 stsp #include "got_error.h"
43 74b37681 2019-02-07 stsp #define BUF_INCR 128
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;
52 74b37681 2019-02-07 stsp #define SIZE_LEFT(b) (b->cb_size - b->cb_len)
54 af45e626 2019-02-08 stsp static const struct got_error *buf_grow(BUF *, size_t);
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.
62 74b37681 2019-02-07 stsp buf_alloc(size_t len)
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 af45e626 2019-02-08 stsp if (b->cb_buf == NULL)
73 af45e626 2019-02-08 stsp return NULL;
75 74b37681 2019-02-07 stsp b->cb_buf = NULL;
77 74b37681 2019-02-07 stsp b->cb_size = len;
78 74b37681 2019-02-07 stsp b->cb_len = 0;
84 74b37681 2019-02-07 stsp * Open the file specified by <path> and load all of its contents into a
86 74b37681 2019-02-07 stsp * Returns the loaded buffer on success or NULL on failure.
87 74b37681 2019-02-07 stsp * Sets errno on error.
90 74b37681 2019-02-07 stsp buf_load(const char *path)
93 74b37681 2019-02-07 stsp ssize_t ret;
96 74b37681 2019-02-07 stsp struct stat st;
101 74b37681 2019-02-07 stsp if ((fd = open(path, O_RDONLY, 0600)) == -1)
104 74b37681 2019-02-07 stsp if (fstat(fd, &st) == -1)
107 74b37681 2019-02-07 stsp if ((uintmax_t)st.st_size > SIZE_MAX) {
108 74b37681 2019-02-07 stsp errno = EFBIG;
111 74b37681 2019-02-07 stsp buf = buf_alloc(st.st_size);
112 74b37681 2019-02-07 stsp for (bp = buf->cb_buf; ; bp += (size_t)ret) {
113 74b37681 2019-02-07 stsp len = SIZE_LEFT(buf);
114 74b37681 2019-02-07 stsp ret = read(fd, bp, len);
115 74b37681 2019-02-07 stsp if (ret == -1) {
116 74b37681 2019-02-07 stsp int saved_errno;
118 74b37681 2019-02-07 stsp saved_errno = errno;
119 74b37681 2019-02-07 stsp buf_free(buf);
120 74b37681 2019-02-07 stsp buf = NULL;
121 74b37681 2019-02-07 stsp errno = saved_errno;
123 74b37681 2019-02-07 stsp } else if (ret == 0)
126 74b37681 2019-02-07 stsp buf->cb_len += (size_t)ret;
130 74b37681 2019-02-07 stsp if (fd != -1) {
131 74b37681 2019-02-07 stsp int saved_errno;
133 74b37681 2019-02-07 stsp /* We may want to preserve errno here. */
134 74b37681 2019-02-07 stsp saved_errno = errno;
135 74b37681 2019-02-07 stsp (void)close(fd);
136 74b37681 2019-02-07 stsp errno = saved_errno;
139 74b37681 2019-02-07 stsp return (buf);
143 74b37681 2019-02-07 stsp buf_free(BUF *b)
145 74b37681 2019-02-07 stsp if (b == NULL)
147 74b37681 2019-02-07 stsp free(b->cb_buf);
152 74b37681 2019-02-07 stsp * Free the buffer <b>'s structural information but do not free the contents
153 74b37681 2019-02-07 stsp * of the buffer. Instead, they are returned and should be freed later using
157 74b37681 2019-02-07 stsp buf_release(BUF *b)
161 74b37681 2019-02-07 stsp tmp = b->cb_buf;
163 74b37681 2019-02-07 stsp return (tmp);
167 74b37681 2019-02-07 stsp buf_get(BUF *b)
169 74b37681 2019-02-07 stsp return (b->cb_buf);
173 74b37681 2019-02-07 stsp * Empty the contents of the buffer <b> and reset pointers.
176 74b37681 2019-02-07 stsp buf_empty(BUF *b)
178 74b37681 2019-02-07 stsp memset(b->cb_buf, 0, b->cb_size);
179 74b37681 2019-02-07 stsp b->cb_len = 0;
183 74b37681 2019-02-07 stsp * Append a single character <c> to the end of the buffer <b>.
185 af45e626 2019-02-08 stsp const struct got_error *
186 74b37681 2019-02-07 stsp buf_putc(BUF *b, int c)
188 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
189 74b37681 2019-02-07 stsp u_char *bp;
191 af45e626 2019-02-08 stsp if (SIZE_LEFT(b) == 0) {
192 af45e626 2019-02-08 stsp err = buf_grow(b, BUF_INCR);
194 af45e626 2019-02-08 stsp return err;
196 74b37681 2019-02-07 stsp bp = b->cb_buf + b->cb_len;
197 74b37681 2019-02-07 stsp *bp = (u_char)c;
198 74b37681 2019-02-07 stsp b->cb_len++;
199 af45e626 2019-02-08 stsp return NULL;
203 74b37681 2019-02-07 stsp * Append a string <s> to the end of buffer <b>.
205 af45e626 2019-02-08 stsp const struct got_error *
206 af45e626 2019-02-08 stsp buf_puts(size_t *newlen, BUF *b, const char *str)
208 af45e626 2019-02-08 stsp return buf_append(newlen, b, str, strlen(str));
212 74b37681 2019-02-07 stsp * Return u_char at buffer position <pos>.
215 74b37681 2019-02-07 stsp buf_getc(BUF *b, size_t pos)
217 74b37681 2019-02-07 stsp return (b->cb_buf[pos]);
221 74b37681 2019-02-07 stsp * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
222 74b37681 2019-02-07 stsp * buffer is too small to accept all data, it will get resized to an
223 74b37681 2019-02-07 stsp * appropriate size to accept all data.
224 74b37681 2019-02-07 stsp * Returns the number of bytes successfully appended to the buffer.
226 af45e626 2019-02-08 stsp const struct got_error *
227 af45e626 2019-02-08 stsp buf_append(size_t *newlen, BUF *b, const void *data, size_t len)
229 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
230 74b37681 2019-02-07 stsp size_t left, rlen;
231 74b37681 2019-02-07 stsp u_char *bp;
233 74b37681 2019-02-07 stsp left = SIZE_LEFT(b);
234 74b37681 2019-02-07 stsp rlen = len;
236 af45e626 2019-02-08 stsp if (left < len) {
237 af45e626 2019-02-08 stsp err = buf_grow(b, len - left);
239 af45e626 2019-02-08 stsp return err;
241 74b37681 2019-02-07 stsp bp = b->cb_buf + b->cb_len;
242 74b37681 2019-02-07 stsp memcpy(bp, data, rlen);
243 74b37681 2019-02-07 stsp b->cb_len += rlen;
245 af45e626 2019-02-08 stsp *newlen = rlen;
246 af45e626 2019-02-08 stsp return NULL;
250 74b37681 2019-02-07 stsp * Returns the size of the buffer that is being used.
253 74b37681 2019-02-07 stsp buf_len(BUF *b)
255 74b37681 2019-02-07 stsp return (b->cb_len);
259 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to the specified <fd>
262 74b37681 2019-02-07 stsp buf_write_fd(BUF *b, int fd)
264 74b37681 2019-02-07 stsp u_char *bp;
265 74b37681 2019-02-07 stsp size_t len;
266 74b37681 2019-02-07 stsp ssize_t ret;
268 74b37681 2019-02-07 stsp len = b->cb_len;
269 74b37681 2019-02-07 stsp bp = b->cb_buf;
272 74b37681 2019-02-07 stsp ret = write(fd, bp, len);
273 74b37681 2019-02-07 stsp if (ret == -1) {
274 74b37681 2019-02-07 stsp if (errno == EINTR || errno == EAGAIN)
276 74b37681 2019-02-07 stsp return (-1);
279 74b37681 2019-02-07 stsp len -= (size_t)ret;
280 74b37681 2019-02-07 stsp bp += (size_t)ret;
281 74b37681 2019-02-07 stsp } while (len > 0);
283 74b37681 2019-02-07 stsp return (0);
287 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to the file whose path is given in
288 74b37681 2019-02-07 stsp * <path>. If the file does not exist, it is created with mode <mode>.
290 af45e626 2019-02-08 stsp const struct got_error *
291 74b37681 2019-02-07 stsp buf_write(BUF *b, const char *path, mode_t mode)
293 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
296 74b37681 2019-02-07 stsp if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
297 74b37681 2019-02-07 stsp if (errno == EACCES && unlink(path) != -1)
300 af45e626 2019-02-08 stsp return got_error_from_errno();
303 74b37681 2019-02-07 stsp if (buf_write_fd(b, fd) == -1) {
304 af45e626 2019-02-08 stsp err = got_error_from_errno();
305 74b37681 2019-02-07 stsp (void)unlink(path);
306 af45e626 2019-02-08 stsp return err;
309 74b37681 2019-02-07 stsp if (fchmod(fd, mode) < 0)
310 af45e626 2019-02-08 stsp err = got_error_from_errno();
312 3a6ce05a 2019-02-11 stsp if (close(fd) != 0 && err == NULL)
313 3a6ce05a 2019-02-11 stsp err = got_error_from_errno();
315 af45e626 2019-02-08 stsp return err;
319 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to a temporary file whose path is
320 74b37681 2019-02-07 stsp * specified using <template> (see mkstemp.3).
321 74b37681 2019-02-07 stsp * NB. This function will modify <template>, as per mkstemp
323 af45e626 2019-02-08 stsp const struct got_error *
324 af45e626 2019-02-08 stsp buf_write_stmp(BUF *b, char *template, struct wklhead *temp_files)
326 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
329 74b37681 2019-02-07 stsp if ((fd = mkstemp(template)) == -1)
330 af45e626 2019-02-08 stsp return got_error_from_errno();
332 af45e626 2019-02-08 stsp worklist_add(template, temp_files);
334 74b37681 2019-02-07 stsp if (buf_write_fd(b, fd) == -1) {
335 af45e626 2019-02-08 stsp err = got_error_from_errno();
336 74b37681 2019-02-07 stsp (void)unlink(template);
339 3a6ce05a 2019-02-11 stsp if (close(fd) != 0 && err == NULL)
340 3a6ce05a 2019-02-11 stsp err = got_error_from_errno();
342 af45e626 2019-02-08 stsp return err;
346 74b37681 2019-02-07 stsp * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
347 74b37681 2019-02-07 stsp * operation regardless of the result.
349 af45e626 2019-02-08 stsp static const struct got_error *
350 74b37681 2019-02-07 stsp buf_grow(BUF *b, size_t len)
352 af45e626 2019-02-08 stsp u_char *buf;
353 af45e626 2019-02-08 stsp buf = reallocarray(b->cb_buf, 1, b->cb_size + len);
354 af45e626 2019-02-08 stsp if (buf == NULL)
355 af45e626 2019-02-08 stsp return got_error_from_errno();
356 af45e626 2019-02-08 stsp b->cb_buf = buf;
357 74b37681 2019-02-07 stsp b->cb_size += len;
358 af45e626 2019-02-08 stsp return NULL;