2 This file is part of GNUnet.
3 Copyright (C) 2006, 2009, 2013 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
22 * @brief functions for buffering IO
23 * @author Christian Grothoff
26 #include "gnunet_util_lib.h"
28 #define LOG(kind, ...) GNUNET_log_from (kind, "util-bio", __VA_ARGS__)
32 * Assumed maximum path length (for source file names).
39 * Size for I/O buffers.
41 #define BIO_BUFFER_SIZE 65536
44 * Maximum size allowed for meta data written/read from disk.
45 * File-sharing limits to 64k, so this should be rather generous.
47 #define MAX_META_DATA (1024 * 1024)
51 * Handle for buffered reading.
53 struct GNUNET_BIO_ReadHandle
56 * Underlying file abstraction.
58 struct GNUNET_DISK_FileHandle *fd;
61 * Error message, NULL if there were no errors.
66 * I/O buffer. Allocated at the end of the struct, do not free!
71 * Number of bytes available in read @e buffer.
76 * Total size of @e buffer.
81 * Current read offset in @e buffer.
88 * Open a file for reading.
90 * @param fn file name to be opened
91 * @return IO handle on success, NULL on error
93 struct GNUNET_BIO_ReadHandle *
94 GNUNET_BIO_read_open (const char *fn)
96 struct GNUNET_DISK_FileHandle *fd;
97 struct GNUNET_BIO_ReadHandle *h;
99 fd = GNUNET_DISK_file_open (fn, GNUNET_DISK_OPEN_READ, GNUNET_DISK_PERM_NONE);
102 h = GNUNET_malloc (sizeof(struct GNUNET_BIO_ReadHandle) + BIO_BUFFER_SIZE);
103 h->buffer = (char *) &h[1];
104 h->size = BIO_BUFFER_SIZE;
111 * Close an open file. Reports if any errors reading
112 * from the file were encountered.
114 * @param h file handle
115 * @param emsg set to the error message
116 * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
119 GNUNET_BIO_read_close (struct GNUNET_BIO_ReadHandle *h, char **emsg)
123 err = (NULL == h->emsg) ? GNUNET_OK : GNUNET_SYSERR;
127 GNUNET_free_non_null (h->emsg);
128 GNUNET_DISK_file_close (h->fd);
135 * Read the contents of a binary file into a buffer.
137 * @param h handle to an open file
138 * @param what describes what is being read (for error message creation)
139 * @param result the buffer to write the result to
140 * @param len the number of bytes to read
141 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
144 GNUNET_BIO_read (struct GNUNET_BIO_ReadHandle *h,
155 return GNUNET_SYSERR;
159 /* first, use buffer */
160 min = h->have - h->pos;
165 GNUNET_memcpy (&dst[pos], &h->buffer[h->pos], min);
170 return GNUNET_OK; /* done! */
171 GNUNET_assert (((off_t) h->have) == h->pos);
173 ret = GNUNET_DISK_file_read (h->fd, h->buffer, h->size);
176 GNUNET_asprintf (&h->emsg,
177 _ ("Error reading `%s': %s"),
180 return GNUNET_SYSERR;
184 GNUNET_asprintf (&h->emsg,
185 _ ("Error reading `%s': %s"),
188 return GNUNET_SYSERR;
193 while (pos < len); /* should always be true */
199 * Read the contents of a binary file into a buffer.
201 * @param h handle to an open file
202 * @param file name of the source file
203 * @param line line number in the source file
204 * @param result the buffer to write the result to
205 * @param len the number of bytes to read
206 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
209 GNUNET_BIO_read_fn (struct GNUNET_BIO_ReadHandle *h,
215 char what[PATH_MAX + 1024];
217 GNUNET_snprintf (what, sizeof(what), "%s:%d", file, line);
218 return GNUNET_BIO_read (h, what, result, len);
223 * Read 0-terminated string from a file.
225 * @param h handle to an open file
226 * @param what describes what is being read (for error message creation)
227 * @param result the buffer to store a pointer to the (allocated) string to
228 * (note that *result could be set to NULL as well)
229 * @param max_length maximum allowed length for the string
230 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
233 GNUNET_BIO_read_string (struct GNUNET_BIO_ReadHandle *h,
241 if (GNUNET_OK != GNUNET_BIO_read_int32 (h, &big))
243 GNUNET_free_non_null (h->emsg);
244 GNUNET_asprintf (&h->emsg, _ ("Error reading length of string `%s'"), what);
245 return GNUNET_SYSERR;
252 if (big > max_length)
254 GNUNET_asprintf (&h->emsg,
255 _ ("String `%s' longer than allowed (%u > %u)"),
259 return GNUNET_SYSERR;
261 buf = GNUNET_malloc (big);
266 if (GNUNET_OK != GNUNET_BIO_read (h, what, buf, big))
270 return GNUNET_SYSERR;
277 * Read metadata container from a file.
279 * @param h handle to an open file
280 * @param what describes what is being read (for error message creation)
281 * @param result the buffer to store a pointer to the (allocated) metadata
282 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
285 GNUNET_BIO_read_meta_data (struct GNUNET_BIO_ReadHandle *h,
287 struct GNUNET_CONTAINER_MetaData **result)
291 struct GNUNET_CONTAINER_MetaData *meta;
293 if (GNUNET_OK != GNUNET_BIO_read_int32 (h, (int32_t *) &size))
294 return GNUNET_SYSERR;
300 if (size > MAX_META_DATA)
302 GNUNET_asprintf (&h->emsg,
303 _ ("Serialized metadata `%s' larger than allowed (%u>%u)"),
307 return GNUNET_SYSERR;
309 buf = GNUNET_malloc (size);
310 if (GNUNET_OK != GNUNET_BIO_read (h, what, buf, size))
313 return GNUNET_SYSERR;
315 meta = GNUNET_CONTAINER_meta_data_deserialize (buf, size);
319 GNUNET_asprintf (&h->emsg, _ ("Metadata `%s' failed to deserialize"), what);
320 return GNUNET_SYSERR;
329 * Read an (u)int32_t.
331 * @param h hande to open file
332 * @param file name of the source file
333 * @param line line number in the source file
334 * @param i address of 32-bit integer to read
335 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
338 GNUNET_BIO_read_int32__ (struct GNUNET_BIO_ReadHandle *h,
345 if (GNUNET_OK != GNUNET_BIO_read_fn (h, file, line, &big, sizeof(int32_t)))
346 return GNUNET_SYSERR;
353 * Read an (u)int64_t.
355 * @param h hande to open file
356 * @param file name of the source file
357 * @param line line number in the source file
358 * @param i address of 64-bit integer to read
359 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
362 GNUNET_BIO_read_int64__ (struct GNUNET_BIO_ReadHandle *h,
369 if (GNUNET_OK != GNUNET_BIO_read_fn (h, file, line, &big, sizeof(int64_t)))
370 return GNUNET_SYSERR;
371 *i = GNUNET_ntohll (big);
377 * Handle for buffered writing.
379 struct GNUNET_BIO_WriteHandle
382 * Underlying file handle.
384 struct GNUNET_DISK_FileHandle *fd;
387 * I/O buffer. Do not free, allocated at the end of the struct.
392 * Number of bytes already in @e buffer.
397 * Total size of @e buffer.
404 * Open a file for writing.
406 * @param fn file name to be opened
407 * @return IO handle on success, NULL on error
409 struct GNUNET_BIO_WriteHandle *
410 GNUNET_BIO_write_open (const char *fn)
412 struct GNUNET_DISK_FileHandle *fd;
413 struct GNUNET_BIO_WriteHandle *h;
416 GNUNET_DISK_file_open (fn,
417 GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_TRUNCATE
418 | GNUNET_DISK_OPEN_CREATE,
419 GNUNET_DISK_PERM_USER_READ
420 | GNUNET_DISK_PERM_USER_WRITE);
423 h = GNUNET_malloc (sizeof(struct GNUNET_BIO_WriteHandle) + BIO_BUFFER_SIZE);
424 h->buffer = (char *) &h[1];
425 h->size = BIO_BUFFER_SIZE;
432 * Close an open file for writing.
434 * @param h file handle
435 * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
438 GNUNET_BIO_write_close (struct GNUNET_BIO_WriteHandle *h)
443 if ((NULL != h->fd) && (GNUNET_OK == (ret = GNUNET_BIO_flush (h))))
444 GNUNET_DISK_file_close (h->fd);
451 * Force a buffered writer to flush its buffer
453 * @param h the writer handle
454 * @return #GNUNET_OK upon success. Upon failure #GNUNET_SYSERR is returned and
458 GNUNET_BIO_flush (struct GNUNET_BIO_WriteHandle *h)
462 ret = GNUNET_DISK_file_write (h->fd, h->buffer, h->have);
463 if (ret != (ssize_t) h->have)
465 GNUNET_DISK_file_close (h->fd);
467 return GNUNET_SYSERR; /* error */
475 * Write a buffer to a file.
477 * @param h handle to open file
478 * @param buffer the data to write
479 * @param n number of bytes to write
480 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
483 GNUNET_BIO_write (struct GNUNET_BIO_WriteHandle *h,
487 const char *src = buffer;
492 return GNUNET_SYSERR;
496 /* first, just use buffer */
497 min = h->size - h->have;
500 GNUNET_memcpy (&h->buffer[h->have], &src[pos], min);
504 return GNUNET_OK; /* done */
505 GNUNET_assert (h->have == h->size);
506 if (GNUNET_OK != GNUNET_BIO_flush (h))
507 return GNUNET_SYSERR; /* error */
509 while (pos < n); /* should always be true */
516 * Write a string to a file.
518 * @param h handle to open file
519 * @param s string to write (can be NULL)
520 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
523 GNUNET_BIO_write_string (struct GNUNET_BIO_WriteHandle *h, const char *s)
527 slen = (uint32_t) ((s == NULL) ? 0 : strlen (s) + 1);
528 if (GNUNET_OK != GNUNET_BIO_write_int32 (h, slen))
529 return GNUNET_SYSERR;
531 return GNUNET_BIO_write (h, s, slen - 1);
537 * Write metadata container to a file.
539 * @param h handle to open file
540 * @param m metadata to write
541 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
544 GNUNET_BIO_write_meta_data (struct GNUNET_BIO_WriteHandle *h,
545 const struct GNUNET_CONTAINER_MetaData *m)
551 return GNUNET_BIO_write_int32 (h, 0);
553 size = GNUNET_CONTAINER_meta_data_serialize (
557 GNUNET_CONTAINER_META_DATA_SERIALIZE_PART);
561 return GNUNET_SYSERR;
563 if ((GNUNET_OK != GNUNET_BIO_write_int32 (h, (uint32_t) size)) ||
564 (GNUNET_OK != GNUNET_BIO_write (h, buf, size)))
567 return GNUNET_SYSERR;
575 * Write an (u)int32_t.
577 * @param h hande to open file
578 * @param i 32-bit integer to write
579 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
582 GNUNET_BIO_write_int32 (struct GNUNET_BIO_WriteHandle *h, int32_t i)
587 return GNUNET_BIO_write (h, &big, sizeof(int32_t));
592 * Write an (u)int64_t.
594 * @param h hande to open file
595 * @param i 64-bit integer to write
596 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
599 GNUNET_BIO_write_int64 (struct GNUNET_BIO_WriteHandle *h, int64_t i)
603 big = GNUNET_htonll (i);
604 return GNUNET_BIO_write (h, &big, sizeof(int64_t));