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 
 40 af45e626 2019-02-08 stsp #include "got_error.h"
 41 af45e626 2019-02-08 stsp 
 42 74b37681 2019-02-07 stsp #define BUF_INCR	128
 43 74b37681 2019-02-07 stsp 
 44 575e8218 2019-10-07 stsp #define SIZE_LEFT(b)	((b)->cb_size - (b)->cb_len)
 45 74b37681 2019-02-07 stsp 
 46 af45e626 2019-02-08 stsp static const struct got_error *buf_grow(BUF *, size_t);
 47 74b37681 2019-02-07 stsp 
 48 74b37681 2019-02-07 stsp /*
 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.
 52 74b37681 2019-02-07 stsp  */
 53 575e8218 2019-10-07 stsp const struct got_error *
 54 575e8218 2019-10-07 stsp buf_alloc(BUF **b, size_t len)
 55 74b37681 2019-02-07 stsp {
 56 575e8218 2019-10-07 stsp 	const struct got_error *err = NULL;
 57 74b37681 2019-02-07 stsp 
 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");
 66 575e8218 2019-10-07 stsp 			free(*b);
 67 575e8218 2019-10-07 stsp 			*b = NULL;
 68 575e8218 2019-10-07 stsp 			return err;
 69 57ebf19f 2019-08-28 hiltjo 		}
 70 af45e626 2019-02-08 stsp 	} else
 71 575e8218 2019-10-07 stsp 		(*b)->cb_buf = NULL;
 72 74b37681 2019-02-07 stsp 
 73 575e8218 2019-10-07 stsp 	(*b)->cb_size = len;
 74 575e8218 2019-10-07 stsp 	(*b)->cb_len = 0;
 75 74b37681 2019-02-07 stsp 
 76 575e8218 2019-10-07 stsp 	return NULL;
 77 74b37681 2019-02-07 stsp }
 78 74b37681 2019-02-07 stsp 
 79 74b37681 2019-02-07 stsp /*
 80 74b37681 2019-02-07 stsp  * Open the file specified by <path> and load all of its contents into a
 81 74b37681 2019-02-07 stsp  * buffer.
 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.
 84 74b37681 2019-02-07 stsp  */
 85 575e8218 2019-10-07 stsp const struct got_error *
 86 575e8218 2019-10-07 stsp buf_load(BUF **buf, const char *path)
 87 74b37681 2019-02-07 stsp {
 88 575e8218 2019-10-07 stsp 	const struct got_error *err = NULL;
 89 74b37681 2019-02-07 stsp 	int fd;
 90 74b37681 2019-02-07 stsp 	ssize_t ret;
 91 74b37681 2019-02-07 stsp 	size_t len;
 92 74b37681 2019-02-07 stsp 	u_char *bp;
 93 74b37681 2019-02-07 stsp 	struct stat st;
 94 74b37681 2019-02-07 stsp 
 95 575e8218 2019-10-07 stsp 	*buf = NULL;
 96 74b37681 2019-02-07 stsp 
 97 575e8218 2019-10-07 stsp 	fd = open(path, O_RDONLY, 0600);
 98 575e8218 2019-10-07 stsp 	if (fd == -1)
 99 575e8218 2019-10-07 stsp 		return got_error_from_errno2("open", path);
100 74b37681 2019-02-07 stsp 
101 575e8218 2019-10-07 stsp 	if (fstat(fd, &st) == -1) {
102 575e8218 2019-10-07 stsp 		err = got_error_from_errno2("fstat", path);
103 74b37681 2019-02-07 stsp 		goto out;
104 575e8218 2019-10-07 stsp 	}
105 74b37681 2019-02-07 stsp 
106 74b37681 2019-02-07 stsp 	if ((uintmax_t)st.st_size > SIZE_MAX) {
107 575e8218 2019-10-07 stsp 		err = got_error_set_errno(EFBIG, path);
108 74b37681 2019-02-07 stsp 		goto out;
109 74b37681 2019-02-07 stsp 	}
110 575e8218 2019-10-07 stsp 	err = buf_alloc(buf, st.st_size);
111 575e8218 2019-10-07 stsp 	if (err)
112 575e8218 2019-10-07 stsp 		goto out;
113 575e8218 2019-10-07 stsp 	for (bp = (*buf)->cb_buf; ; bp += (size_t)ret) {
114 575e8218 2019-10-07 stsp 		len = SIZE_LEFT(*buf);
115 74b37681 2019-02-07 stsp 		ret = read(fd, bp, len);
116 74b37681 2019-02-07 stsp 		if (ret == -1) {
117 575e8218 2019-10-07 stsp 			err = got_error_from_errno2("read", path);
118 74b37681 2019-02-07 stsp 			goto out;
119 74b37681 2019-02-07 stsp 		} else if (ret == 0)
120 74b37681 2019-02-07 stsp 			break;
121 74b37681 2019-02-07 stsp 
122 575e8218 2019-10-07 stsp 		(*buf)->cb_len += (size_t)ret;
123 74b37681 2019-02-07 stsp 	}
124 74b37681 2019-02-07 stsp 
125 74b37681 2019-02-07 stsp out:
126 575e8218 2019-10-07 stsp 	if (close(fd) == -1 && err == NULL)
127 575e8218 2019-10-07 stsp 		err = got_error_from_errno2("close", path);
128 575e8218 2019-10-07 stsp 	if (err) {
129 575e8218 2019-10-07 stsp 		buf_free(*buf);
130 575e8218 2019-10-07 stsp 		*buf = NULL;
131 74b37681 2019-02-07 stsp 	}
132 575e8218 2019-10-07 stsp 	return err;
133 74b37681 2019-02-07 stsp }
134 74b37681 2019-02-07 stsp 
135 74b37681 2019-02-07 stsp void
136 74b37681 2019-02-07 stsp buf_free(BUF *b)
137 74b37681 2019-02-07 stsp {
138 74b37681 2019-02-07 stsp 	if (b == NULL)
139 74b37681 2019-02-07 stsp 		return;
140 74b37681 2019-02-07 stsp 	free(b->cb_buf);
141 74b37681 2019-02-07 stsp 	free(b);
142 74b37681 2019-02-07 stsp }
143 74b37681 2019-02-07 stsp 
144 74b37681 2019-02-07 stsp /*
145 74b37681 2019-02-07 stsp  * Free the buffer <b>'s structural information but do not free the contents
146 74b37681 2019-02-07 stsp  * of the buffer.  Instead, they are returned and should be freed later using
147 74b37681 2019-02-07 stsp  * free().
148 74b37681 2019-02-07 stsp  */
149 74b37681 2019-02-07 stsp void *
150 74b37681 2019-02-07 stsp buf_release(BUF *b)
151 74b37681 2019-02-07 stsp {
152 74b37681 2019-02-07 stsp 	void *tmp;
153 74b37681 2019-02-07 stsp 
154 74b37681 2019-02-07 stsp 	tmp = b->cb_buf;
155 74b37681 2019-02-07 stsp 	free(b);
156 74b37681 2019-02-07 stsp 	return (tmp);
157 74b37681 2019-02-07 stsp }
158 74b37681 2019-02-07 stsp 
159 74b37681 2019-02-07 stsp u_char *
160 74b37681 2019-02-07 stsp buf_get(BUF *b)
161 74b37681 2019-02-07 stsp {
162 74b37681 2019-02-07 stsp 	return (b->cb_buf);
163 74b37681 2019-02-07 stsp }
164 74b37681 2019-02-07 stsp 
165 74b37681 2019-02-07 stsp /*
166 74b37681 2019-02-07 stsp  * Empty the contents of the buffer <b> and reset pointers.
167 74b37681 2019-02-07 stsp  */
168 74b37681 2019-02-07 stsp void
169 74b37681 2019-02-07 stsp buf_empty(BUF *b)
170 74b37681 2019-02-07 stsp {
171 74b37681 2019-02-07 stsp 	memset(b->cb_buf, 0, b->cb_size);
172 74b37681 2019-02-07 stsp 	b->cb_len = 0;
173 74b37681 2019-02-07 stsp }
174 74b37681 2019-02-07 stsp 
175 74b37681 2019-02-07 stsp /*
176 74b37681 2019-02-07 stsp  * Append a single character <c> to the end of the buffer <b>.
177 74b37681 2019-02-07 stsp  */
178 af45e626 2019-02-08 stsp const struct got_error *
179 74b37681 2019-02-07 stsp buf_putc(BUF *b, int c)
180 74b37681 2019-02-07 stsp {
181 af45e626 2019-02-08 stsp 	const struct got_error *err = NULL;
182 74b37681 2019-02-07 stsp 	u_char *bp;
183 74b37681 2019-02-07 stsp 
184 af45e626 2019-02-08 stsp 	if (SIZE_LEFT(b) == 0) {
185 af45e626 2019-02-08 stsp 		err = buf_grow(b, BUF_INCR);
186 af45e626 2019-02-08 stsp 		if (err)
187 af45e626 2019-02-08 stsp 			return err;
188 af45e626 2019-02-08 stsp 	}
189 74b37681 2019-02-07 stsp 	bp = b->cb_buf + b->cb_len;
190 74b37681 2019-02-07 stsp 	*bp = (u_char)c;
191 74b37681 2019-02-07 stsp 	b->cb_len++;
192 af45e626 2019-02-08 stsp 	return NULL;
193 74b37681 2019-02-07 stsp }
194 74b37681 2019-02-07 stsp 
195 74b37681 2019-02-07 stsp /*
196 74b37681 2019-02-07 stsp  * Append a string <s> to the end of buffer <b>.
197 74b37681 2019-02-07 stsp  */
198 af45e626 2019-02-08 stsp const struct got_error *
199 af45e626 2019-02-08 stsp buf_puts(size_t *newlen, BUF *b, const char *str)
200 74b37681 2019-02-07 stsp {
201 af45e626 2019-02-08 stsp 	return buf_append(newlen, b, str, strlen(str));
202 74b37681 2019-02-07 stsp }
203 74b37681 2019-02-07 stsp 
204 74b37681 2019-02-07 stsp /*
205 74b37681 2019-02-07 stsp  * Return u_char at buffer position <pos>.
206 74b37681 2019-02-07 stsp  */
207 74b37681 2019-02-07 stsp u_char
208 74b37681 2019-02-07 stsp buf_getc(BUF *b, size_t pos)
209 74b37681 2019-02-07 stsp {
210 74b37681 2019-02-07 stsp 	return (b->cb_buf[pos]);
211 74b37681 2019-02-07 stsp }
212 74b37681 2019-02-07 stsp 
213 74b37681 2019-02-07 stsp /*
214 74b37681 2019-02-07 stsp  * Append <len> bytes of data pointed to by <data> to the buffer <b>.  If the
215 74b37681 2019-02-07 stsp  * buffer is too small to accept all data, it will get resized to an
216 74b37681 2019-02-07 stsp  * appropriate size to accept all data.
217 74b37681 2019-02-07 stsp  * Returns the number of bytes successfully appended to the buffer.
218 74b37681 2019-02-07 stsp  */
219 af45e626 2019-02-08 stsp const struct got_error *
220 af45e626 2019-02-08 stsp buf_append(size_t *newlen, BUF *b, const void *data, size_t len)
221 74b37681 2019-02-07 stsp {
222 af45e626 2019-02-08 stsp 	const struct got_error *err = NULL;
223 74b37681 2019-02-07 stsp 	size_t left, rlen;
224 74b37681 2019-02-07 stsp 	u_char *bp;
225 74b37681 2019-02-07 stsp 
226 74b37681 2019-02-07 stsp 	left = SIZE_LEFT(b);
227 74b37681 2019-02-07 stsp 	rlen = len;
228 74b37681 2019-02-07 stsp 
229 af45e626 2019-02-08 stsp 	if (left < len) {
230 af45e626 2019-02-08 stsp 		err = buf_grow(b, len - left);
231 af45e626 2019-02-08 stsp 		if (err)
232 af45e626 2019-02-08 stsp 			return err;
233 af45e626 2019-02-08 stsp 	}
234 74b37681 2019-02-07 stsp 	bp = b->cb_buf + b->cb_len;
235 74b37681 2019-02-07 stsp 	memcpy(bp, data, rlen);
236 74b37681 2019-02-07 stsp 	b->cb_len += rlen;
237 74b37681 2019-02-07 stsp 
238 af45e626 2019-02-08 stsp 	*newlen = rlen;
239 af45e626 2019-02-08 stsp 	return NULL;
240 74b37681 2019-02-07 stsp }
241 74b37681 2019-02-07 stsp 
242 74b37681 2019-02-07 stsp /*
243 74b37681 2019-02-07 stsp  * Returns the size of the buffer that is being used.
244 74b37681 2019-02-07 stsp  */
245 74b37681 2019-02-07 stsp size_t
246 74b37681 2019-02-07 stsp buf_len(BUF *b)
247 74b37681 2019-02-07 stsp {
248 74b37681 2019-02-07 stsp 	return (b->cb_len);
249 74b37681 2019-02-07 stsp }
250 74b37681 2019-02-07 stsp 
251 74b37681 2019-02-07 stsp /*
252 74b37681 2019-02-07 stsp  * Write the contents of the buffer <b> to the specified <fd>
253 74b37681 2019-02-07 stsp  */
254 74b37681 2019-02-07 stsp int
255 74b37681 2019-02-07 stsp buf_write_fd(BUF *b, int fd)
256 74b37681 2019-02-07 stsp {
257 74b37681 2019-02-07 stsp 	u_char *bp;
258 74b37681 2019-02-07 stsp 	size_t len;
259 74b37681 2019-02-07 stsp 	ssize_t ret;
260 74b37681 2019-02-07 stsp 
261 74b37681 2019-02-07 stsp 	len = b->cb_len;
262 74b37681 2019-02-07 stsp 	bp = b->cb_buf;
263 74b37681 2019-02-07 stsp 
264 74b37681 2019-02-07 stsp 	do {
265 74b37681 2019-02-07 stsp 		ret = write(fd, bp, len);
266 74b37681 2019-02-07 stsp 		if (ret == -1) {
267 74b37681 2019-02-07 stsp 			if (errno == EINTR || errno == EAGAIN)
268 74b37681 2019-02-07 stsp 				continue;
269 74b37681 2019-02-07 stsp 			return (-1);
270 74b37681 2019-02-07 stsp 		}
271 74b37681 2019-02-07 stsp 
272 74b37681 2019-02-07 stsp 		len -= (size_t)ret;
273 74b37681 2019-02-07 stsp 		bp += (size_t)ret;
274 74b37681 2019-02-07 stsp 	} while (len > 0);
275 74b37681 2019-02-07 stsp 
276 74b37681 2019-02-07 stsp 	return (0);
277 74b37681 2019-02-07 stsp }
278 74b37681 2019-02-07 stsp 
279 74b37681 2019-02-07 stsp /*
280 74b37681 2019-02-07 stsp  * Write the contents of the buffer <b> to the file whose path is given in
281 74b37681 2019-02-07 stsp  * <path>.  If the file does not exist, it is created with mode <mode>.
282 74b37681 2019-02-07 stsp  */
283 af45e626 2019-02-08 stsp const struct got_error *
284 74b37681 2019-02-07 stsp buf_write(BUF *b, const char *path, mode_t mode)
285 74b37681 2019-02-07 stsp {
286 af45e626 2019-02-08 stsp 	const struct got_error *err = NULL;
287 74b37681 2019-02-07 stsp 	int fd;
288 74b37681 2019-02-07 stsp  open:
289 74b37681 2019-02-07 stsp 	if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
290 202329ae 2019-08-11 stsp 		err = got_error_from_errno2("open", path);
291 74b37681 2019-02-07 stsp 		if (errno == EACCES && unlink(path) != -1)
292 74b37681 2019-02-07 stsp 			goto open;
293 74b37681 2019-02-07 stsp 		else
294 202329ae 2019-08-11 stsp 			return err;
295 74b37681 2019-02-07 stsp 	}
296 74b37681 2019-02-07 stsp 
297 74b37681 2019-02-07 stsp 	if (buf_write_fd(b, fd) == -1) {
298 638f9024 2019-05-13 stsp 		err = got_error_from_errno("buf_write_fd");
299 74b37681 2019-02-07 stsp 		(void)unlink(path);
300 af45e626 2019-02-08 stsp 		return err;
301 74b37681 2019-02-07 stsp 	}
302 74b37681 2019-02-07 stsp 
303 74b37681 2019-02-07 stsp 	if (fchmod(fd, mode) < 0)
304 638f9024 2019-05-13 stsp 		err = got_error_from_errno2("fchmod", path);
305 74b37681 2019-02-07 stsp 
306 3a6ce05a 2019-02-11 stsp 	if (close(fd) != 0 && err == NULL)
307 638f9024 2019-05-13 stsp 		err = got_error_from_errno2("close", path);
308 74b37681 2019-02-07 stsp 
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 /*
313 74b37681 2019-02-07 stsp  * Write the contents of the buffer <b> to a temporary file whose path is
314 74b37681 2019-02-07 stsp  * specified using <template> (see mkstemp.3).
315 74b37681 2019-02-07 stsp  * NB. This function will modify <template>, as per mkstemp
316 74b37681 2019-02-07 stsp  */
317 af45e626 2019-02-08 stsp const struct got_error *
318 96cbb597 2019-10-09 stsp buf_write_stmp(BUF *b, char *template)
319 74b37681 2019-02-07 stsp {
320 af45e626 2019-02-08 stsp 	const struct got_error *err = NULL;
321 74b37681 2019-02-07 stsp 	int fd;
322 74b37681 2019-02-07 stsp 
323 74b37681 2019-02-07 stsp 	if ((fd = mkstemp(template)) == -1)
324 638f9024 2019-05-13 stsp 		return got_error_from_errno("mkstemp");
325 74b37681 2019-02-07 stsp 
326 74b37681 2019-02-07 stsp 	if (buf_write_fd(b, fd) == -1) {
327 638f9024 2019-05-13 stsp 		err = got_error_from_errno("buf_write_fd");
328 74b37681 2019-02-07 stsp 		(void)unlink(template);
329 74b37681 2019-02-07 stsp 	}
330 74b37681 2019-02-07 stsp 
331 3a6ce05a 2019-02-11 stsp 	if (close(fd) != 0 && err == NULL)
332 638f9024 2019-05-13 stsp 		err = got_error_from_errno("close");
333 3a6ce05a 2019-02-11 stsp 
334 af45e626 2019-02-08 stsp 	return err;
335 74b37681 2019-02-07 stsp }
336 74b37681 2019-02-07 stsp 
337 74b37681 2019-02-07 stsp /*
338 74b37681 2019-02-07 stsp  * Grow the buffer <b> by <len> bytes.  The contents are unchanged by this
339 74b37681 2019-02-07 stsp  * operation regardless of the result.
340 74b37681 2019-02-07 stsp  */
341 af45e626 2019-02-08 stsp static const struct got_error *
342 74b37681 2019-02-07 stsp buf_grow(BUF *b, size_t len)
343 74b37681 2019-02-07 stsp {
344 af45e626 2019-02-08 stsp 	u_char *buf;
345 af45e626 2019-02-08 stsp 	buf = reallocarray(b->cb_buf, 1, b->cb_size + len);
346 af45e626 2019-02-08 stsp 	if (buf == NULL)
347 638f9024 2019-05-13 stsp 		return got_error_from_errno("reallocarray");
348 af45e626 2019-02-08 stsp 	b->cb_buf = buf;
349 74b37681 2019-02-07 stsp 	b->cb_size += len;
350 af45e626 2019-02-08 stsp 	return NULL;
351 74b37681 2019-02-07 stsp }