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"
40 af45e626 2019-02-08 stsp #include "got_error.h"
42 74b37681 2019-02-07 stsp #define BUF_INCR 128
44 575e8218 2019-10-07 stsp #define SIZE_LEFT(b) ((b)->cb_size - (b)->cb_len)
46 af45e626 2019-02-08 stsp static const struct got_error *buf_grow(BUF *, size_t);
49 74b37681 2019-02-07 stsp * Create a new buffer structure and return a pointer to it. This structure
50 74b37681 2019-02-07 stsp * uses dynamically-allocated memory and must be freed with buf_free(), once
51 74b37681 2019-02-07 stsp * the buffer is no longer needed.
53 575e8218 2019-10-07 stsp const struct got_error *
54 575e8218 2019-10-07 stsp buf_alloc(BUF **b, size_t len)
56 575e8218 2019-10-07 stsp const struct got_error *err = NULL;
58 575e8218 2019-10-07 stsp *b = malloc(sizeof(**b));
59 575e8218 2019-10-07 stsp if (*b == NULL)
60 af45e626 2019-02-08 stsp return NULL;
61 74b37681 2019-02-07 stsp /* Postpone creation of zero-sized buffers */
62 af45e626 2019-02-08 stsp if (len > 0) {
63 575e8218 2019-10-07 stsp (*b)->cb_buf = calloc(1, len);
64 575e8218 2019-10-07 stsp if ((*b)->cb_buf == NULL) {
65 575e8218 2019-10-07 stsp err = got_error_from_errno("calloc");
71 575e8218 2019-10-07 stsp (*b)->cb_buf = NULL;
73 575e8218 2019-10-07 stsp (*b)->cb_size = len;
74 575e8218 2019-10-07 stsp (*b)->cb_len = 0;
76 575e8218 2019-10-07 stsp return NULL;
80 74b37681 2019-02-07 stsp * Open the file specified by <path> and load all of its contents into a
82 74b37681 2019-02-07 stsp * Returns the loaded buffer on success or NULL on failure.
83 74b37681 2019-02-07 stsp * Sets errno on error.
85 575e8218 2019-10-07 stsp const struct got_error *
86 db590691 2021-06-02 stsp buf_load(BUF **buf, FILE *f)
88 575e8218 2019-10-07 stsp const struct got_error *err = NULL;
92 74b37681 2019-02-07 stsp struct stat st;
94 575e8218 2019-10-07 stsp *buf = NULL;
96 db590691 2021-06-02 stsp if (fstat(fileno(f), &st) == -1) {
97 db590691 2021-06-02 stsp err = got_error_from_errno("fstat");
101 74b37681 2019-02-07 stsp if ((uintmax_t)st.st_size > SIZE_MAX) {
102 db590691 2021-06-02 stsp err = got_error_set_errno(EFBIG,
103 db590691 2021-06-02 stsp "cannot fit file into memory buffer");
106 575e8218 2019-10-07 stsp err = buf_alloc(buf, st.st_size);
109 db590691 2021-06-02 stsp for (bp = (*buf)->cb_buf; ; bp += ret) {
110 575e8218 2019-10-07 stsp len = SIZE_LEFT(*buf);
111 db590691 2021-06-02 stsp ret = fread(bp, 1, len, f);
112 db590691 2021-06-02 stsp if (ret == 0 && ferror(f)) {
113 db590691 2021-06-02 stsp err = got_ferror(f, GOT_ERR_IO);
115 74b37681 2019-02-07 stsp } else if (ret == 0)
118 575e8218 2019-10-07 stsp (*buf)->cb_len += (size_t)ret;
123 575e8218 2019-10-07 stsp buf_free(*buf);
124 575e8218 2019-10-07 stsp *buf = NULL;
126 575e8218 2019-10-07 stsp return err;
130 74b37681 2019-02-07 stsp buf_free(BUF *b)
132 74b37681 2019-02-07 stsp if (b == NULL)
134 74b37681 2019-02-07 stsp free(b->cb_buf);
139 74b37681 2019-02-07 stsp * Free the buffer <b>'s structural information but do not free the contents
140 74b37681 2019-02-07 stsp * of the buffer. Instead, they are returned and should be freed later using
144 74b37681 2019-02-07 stsp buf_release(BUF *b)
148 74b37681 2019-02-07 stsp tmp = b->cb_buf;
150 74b37681 2019-02-07 stsp return (tmp);
154 74b37681 2019-02-07 stsp buf_get(BUF *b)
156 74b37681 2019-02-07 stsp return (b->cb_buf);
160 74b37681 2019-02-07 stsp * Empty the contents of the buffer <b> and reset pointers.
163 74b37681 2019-02-07 stsp buf_empty(BUF *b)
165 74b37681 2019-02-07 stsp memset(b->cb_buf, 0, b->cb_size);
166 74b37681 2019-02-07 stsp b->cb_len = 0;
170 74b37681 2019-02-07 stsp * Append a single character <c> to the end of the buffer <b>.
172 af45e626 2019-02-08 stsp const struct got_error *
173 74b37681 2019-02-07 stsp buf_putc(BUF *b, int c)
175 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
176 74b37681 2019-02-07 stsp u_char *bp;
178 af45e626 2019-02-08 stsp if (SIZE_LEFT(b) == 0) {
179 af45e626 2019-02-08 stsp err = buf_grow(b, BUF_INCR);
181 af45e626 2019-02-08 stsp return err;
183 74b37681 2019-02-07 stsp bp = b->cb_buf + b->cb_len;
184 74b37681 2019-02-07 stsp *bp = (u_char)c;
185 74b37681 2019-02-07 stsp b->cb_len++;
186 af45e626 2019-02-08 stsp return NULL;
190 74b37681 2019-02-07 stsp * Append a string <s> to the end of buffer <b>.
192 af45e626 2019-02-08 stsp const struct got_error *
193 af45e626 2019-02-08 stsp buf_puts(size_t *newlen, BUF *b, const char *str)
195 af45e626 2019-02-08 stsp return buf_append(newlen, b, str, strlen(str));
199 74b37681 2019-02-07 stsp * Return u_char at buffer position <pos>.
202 74b37681 2019-02-07 stsp buf_getc(BUF *b, size_t pos)
204 74b37681 2019-02-07 stsp return (b->cb_buf[pos]);
208 74b37681 2019-02-07 stsp * Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
209 74b37681 2019-02-07 stsp * buffer is too small to accept all data, it will get resized to an
210 74b37681 2019-02-07 stsp * appropriate size to accept all data.
211 74b37681 2019-02-07 stsp * Returns the number of bytes successfully appended to the buffer.
213 af45e626 2019-02-08 stsp const struct got_error *
214 af45e626 2019-02-08 stsp buf_append(size_t *newlen, BUF *b, const void *data, size_t len)
216 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
217 74b37681 2019-02-07 stsp size_t left, rlen;
218 74b37681 2019-02-07 stsp u_char *bp;
220 74b37681 2019-02-07 stsp left = SIZE_LEFT(b);
221 74b37681 2019-02-07 stsp rlen = len;
223 af45e626 2019-02-08 stsp if (left < len) {
224 af45e626 2019-02-08 stsp err = buf_grow(b, len - left);
226 af45e626 2019-02-08 stsp return err;
228 74b37681 2019-02-07 stsp bp = b->cb_buf + b->cb_len;
229 74b37681 2019-02-07 stsp memcpy(bp, data, rlen);
230 74b37681 2019-02-07 stsp b->cb_len += rlen;
232 af45e626 2019-02-08 stsp *newlen = rlen;
233 af45e626 2019-02-08 stsp return NULL;
237 74b37681 2019-02-07 stsp * Returns the size of the buffer that is being used.
240 74b37681 2019-02-07 stsp buf_len(BUF *b)
242 74b37681 2019-02-07 stsp return (b->cb_len);
246 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to the specified <fd>
249 74b37681 2019-02-07 stsp buf_write_fd(BUF *b, int fd)
251 74b37681 2019-02-07 stsp u_char *bp;
252 74b37681 2019-02-07 stsp size_t len;
253 74b37681 2019-02-07 stsp ssize_t ret;
255 74b37681 2019-02-07 stsp len = b->cb_len;
256 74b37681 2019-02-07 stsp bp = b->cb_buf;
259 74b37681 2019-02-07 stsp ret = write(fd, bp, len);
260 74b37681 2019-02-07 stsp if (ret == -1) {
261 74b37681 2019-02-07 stsp if (errno == EINTR || errno == EAGAIN)
263 74b37681 2019-02-07 stsp return (-1);
266 74b37681 2019-02-07 stsp len -= (size_t)ret;
267 74b37681 2019-02-07 stsp bp += (size_t)ret;
268 74b37681 2019-02-07 stsp } while (len > 0);
270 74b37681 2019-02-07 stsp return (0);
274 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to the file whose path is given in
275 74b37681 2019-02-07 stsp * <path>. If the file does not exist, it is created with mode <mode>.
277 af45e626 2019-02-08 stsp const struct got_error *
278 74b37681 2019-02-07 stsp buf_write(BUF *b, const char *path, mode_t mode)
280 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
283 8bd0cdad 2021-12-31 stsp if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, mode)) == -1) {
284 202329ae 2019-08-11 stsp err = got_error_from_errno2("open", path);
285 74b37681 2019-02-07 stsp if (errno == EACCES && unlink(path) != -1)
288 202329ae 2019-08-11 stsp return err;
291 74b37681 2019-02-07 stsp if (buf_write_fd(b, fd) == -1) {
292 638f9024 2019-05-13 stsp err = got_error_from_errno("buf_write_fd");
293 74b37681 2019-02-07 stsp (void)unlink(path);
294 af45e626 2019-02-08 stsp return err;
297 74b37681 2019-02-07 stsp if (fchmod(fd, mode) < 0)
298 638f9024 2019-05-13 stsp err = got_error_from_errno2("fchmod", path);
300 08578a35 2021-01-22 stsp if (close(fd) == -1 && err == NULL)
301 638f9024 2019-05-13 stsp err = got_error_from_errno2("close", path);
303 af45e626 2019-02-08 stsp return err;
307 74b37681 2019-02-07 stsp * Write the contents of the buffer <b> to a temporary file whose path is
308 74b37681 2019-02-07 stsp * specified using <template> (see mkstemp.3).
309 74b37681 2019-02-07 stsp * NB. This function will modify <template>, as per mkstemp
311 af45e626 2019-02-08 stsp const struct got_error *
312 96cbb597 2019-10-09 stsp buf_write_stmp(BUF *b, char *template)
314 af45e626 2019-02-08 stsp const struct got_error *err = NULL;
317 74b37681 2019-02-07 stsp if ((fd = mkstemp(template)) == -1)
318 638f9024 2019-05-13 stsp return got_error_from_errno("mkstemp");
320 74b37681 2019-02-07 stsp if (buf_write_fd(b, fd) == -1) {
321 638f9024 2019-05-13 stsp err = got_error_from_errno("buf_write_fd");
322 74b37681 2019-02-07 stsp (void)unlink(template);
325 08578a35 2021-01-22 stsp if (close(fd) == -1 && err == NULL)
326 638f9024 2019-05-13 stsp err = got_error_from_errno("close");
328 af45e626 2019-02-08 stsp return err;
332 74b37681 2019-02-07 stsp * Grow the buffer <b> by <len> bytes. The contents are unchanged by this
333 74b37681 2019-02-07 stsp * operation regardless of the result.
335 af45e626 2019-02-08 stsp static const struct got_error *
336 74b37681 2019-02-07 stsp buf_grow(BUF *b, size_t len)
338 af45e626 2019-02-08 stsp u_char *buf;
339 af45e626 2019-02-08 stsp buf = reallocarray(b->cb_buf, 1, b->cb_size + len);
340 af45e626 2019-02-08 stsp if (buf == NULL)
341 638f9024 2019-05-13 stsp return got_error_from_errno("reallocarray");
342 af45e626 2019-02-08 stsp b->cb_buf = buf;
343 74b37681 2019-02-07 stsp b->cb_size += len;
344 af45e626 2019-02-08 stsp return NULL;