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Diffstat (limited to 'src/lib/util/mst.c')
-rw-r--r-- | src/lib/util/mst.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/src/lib/util/mst.c b/src/lib/util/mst.c new file mode 100644 index 000000000..d8509b7ec --- /dev/null +++ b/src/lib/util/mst.c | |||
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1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | Copyright (C) 2010, 2016, 2017 GNUnet e.V. | ||
4 | |||
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. | ||
9 | |||
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. | ||
14 | |||
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/>. | ||
17 | |||
18 | SPDX-License-Identifier: AGPL3.0-or-later | ||
19 | */ | ||
20 | |||
21 | /** | ||
22 | * @file util/mst.c | ||
23 | * @brief convenience functions for handling inbound message buffers | ||
24 | * @author Christian Grothoff | ||
25 | */ | ||
26 | |||
27 | |||
28 | #include "platform.h" | ||
29 | #include "gnunet_util_lib.h" | ||
30 | |||
31 | |||
32 | #if HAVE_UNALIGNED_64_ACCESS | ||
33 | #define ALIGN_FACTOR 4 | ||
34 | #else | ||
35 | #define ALIGN_FACTOR 8 | ||
36 | #endif | ||
37 | |||
38 | #define LOG(kind, ...) GNUNET_log_from (kind, "util-mst", __VA_ARGS__) | ||
39 | |||
40 | |||
41 | /** | ||
42 | * Handle to a message stream tokenizer. | ||
43 | */ | ||
44 | struct GNUNET_MessageStreamTokenizer | ||
45 | { | ||
46 | /** | ||
47 | * Function to call on completed messages. | ||
48 | */ | ||
49 | GNUNET_MessageTokenizerCallback cb; | ||
50 | |||
51 | /** | ||
52 | * Closure for @e cb. | ||
53 | */ | ||
54 | void *cb_cls; | ||
55 | |||
56 | /** | ||
57 | * Size of the buffer (starting at @e hdr). | ||
58 | */ | ||
59 | size_t curr_buf; | ||
60 | |||
61 | /** | ||
62 | * How many bytes in buffer have we already processed? | ||
63 | */ | ||
64 | size_t off; | ||
65 | |||
66 | /** | ||
67 | * How many bytes in buffer are valid right now? | ||
68 | */ | ||
69 | size_t pos; | ||
70 | |||
71 | /** | ||
72 | * Beginning of the buffer. Typed like this to force alignment. | ||
73 | */ | ||
74 | struct GNUNET_MessageHeader *hdr; | ||
75 | }; | ||
76 | |||
77 | |||
78 | /** | ||
79 | * Create a message stream tokenizer. | ||
80 | * | ||
81 | * @param cb function to call on completed messages | ||
82 | * @param cb_cls closure for @a cb | ||
83 | * @return handle to tokenizer | ||
84 | */ | ||
85 | struct GNUNET_MessageStreamTokenizer * | ||
86 | GNUNET_MST_create (GNUNET_MessageTokenizerCallback cb, | ||
87 | void *cb_cls) | ||
88 | { | ||
89 | struct GNUNET_MessageStreamTokenizer *ret; | ||
90 | |||
91 | ret = GNUNET_new (struct GNUNET_MessageStreamTokenizer); | ||
92 | ret->hdr = GNUNET_malloc (GNUNET_MIN_MESSAGE_SIZE); | ||
93 | ret->curr_buf = GNUNET_MIN_MESSAGE_SIZE; | ||
94 | ret->cb = cb; | ||
95 | ret->cb_cls = cb_cls; | ||
96 | return ret; | ||
97 | } | ||
98 | |||
99 | |||
100 | enum GNUNET_GenericReturnValue | ||
101 | GNUNET_MST_from_buffer (struct GNUNET_MessageStreamTokenizer *mst, | ||
102 | const char *buf, | ||
103 | size_t size, | ||
104 | int purge, | ||
105 | int one_shot) | ||
106 | { | ||
107 | const struct GNUNET_MessageHeader *hdr; | ||
108 | size_t delta; | ||
109 | uint16_t want; | ||
110 | char *ibuf; | ||
111 | int ret; | ||
112 | int cbret; | ||
113 | |||
114 | GNUNET_assert (mst->off <= mst->pos); | ||
115 | GNUNET_assert (mst->pos <= mst->curr_buf); | ||
116 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
117 | "MST receives %u bytes with %u (%u/%u) bytes already in private buffer\n", | ||
118 | (unsigned int) size, | ||
119 | (unsigned int) (mst->pos - mst->off), | ||
120 | (unsigned int) mst->pos, | ||
121 | (unsigned int) mst->off); | ||
122 | ret = GNUNET_OK; | ||
123 | ibuf = (char *) mst->hdr; | ||
124 | while (mst->pos > 0) | ||
125 | { | ||
126 | do_align: | ||
127 | GNUNET_assert (mst->pos >= mst->off); | ||
128 | if ((mst->curr_buf - mst->off < sizeof(struct GNUNET_MessageHeader)) || | ||
129 | (0 != (mst->off % ALIGN_FACTOR))) | ||
130 | { | ||
131 | /* need to align or need more space */ | ||
132 | mst->pos -= mst->off; | ||
133 | memmove (ibuf, | ||
134 | &ibuf[mst->off], | ||
135 | mst->pos); | ||
136 | mst->off = 0; | ||
137 | } | ||
138 | if (mst->pos - mst->off < sizeof(struct GNUNET_MessageHeader)) | ||
139 | { | ||
140 | delta | ||
141 | = GNUNET_MIN (sizeof(struct GNUNET_MessageHeader) | ||
142 | - (mst->pos - mst->off), | ||
143 | size); | ||
144 | GNUNET_memcpy (&ibuf[mst->pos], | ||
145 | buf, | ||
146 | delta); | ||
147 | mst->pos += delta; | ||
148 | buf += delta; | ||
149 | size -= delta; | ||
150 | } | ||
151 | if (mst->pos - mst->off < sizeof(struct GNUNET_MessageHeader)) | ||
152 | { | ||
153 | if (purge) | ||
154 | { | ||
155 | mst->off = 0; | ||
156 | mst->pos = 0; | ||
157 | } | ||
158 | return GNUNET_OK; | ||
159 | } | ||
160 | hdr = (const struct GNUNET_MessageHeader *) &ibuf[mst->off]; | ||
161 | want = ntohs (hdr->size); | ||
162 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
163 | "We want to read message of size %u\n", | ||
164 | want); | ||
165 | if (want < sizeof(struct GNUNET_MessageHeader)) | ||
166 | { | ||
167 | GNUNET_break_op (0); | ||
168 | return GNUNET_SYSERR; | ||
169 | } | ||
170 | if ((mst->curr_buf - mst->off < want) && | ||
171 | (mst->off > 0)) | ||
172 | { | ||
173 | /* can get more space by moving */ | ||
174 | mst->pos -= mst->off; | ||
175 | memmove (ibuf, | ||
176 | &ibuf[mst->off], | ||
177 | mst->pos); | ||
178 | mst->off = 0; | ||
179 | } | ||
180 | if (mst->curr_buf < want) | ||
181 | { | ||
182 | /* need to get more space by growing buffer */ | ||
183 | GNUNET_assert (0 == mst->off); | ||
184 | mst->hdr = GNUNET_realloc (mst->hdr, | ||
185 | want); | ||
186 | ibuf = (char *) mst->hdr; | ||
187 | mst->curr_buf = want; | ||
188 | } | ||
189 | hdr = (const struct GNUNET_MessageHeader *) &ibuf[mst->off]; | ||
190 | if (mst->pos - mst->off < want) | ||
191 | { | ||
192 | delta = GNUNET_MIN (want - (mst->pos - mst->off), | ||
193 | size); | ||
194 | GNUNET_assert (mst->pos + delta <= mst->curr_buf); | ||
195 | GNUNET_memcpy (&ibuf[mst->pos], | ||
196 | buf, | ||
197 | delta); | ||
198 | mst->pos += delta; | ||
199 | buf += delta; | ||
200 | size -= delta; | ||
201 | } | ||
202 | if (mst->pos - mst->off < want) | ||
203 | { | ||
204 | if (purge) | ||
205 | { | ||
206 | mst->off = 0; | ||
207 | mst->pos = 0; | ||
208 | } | ||
209 | return GNUNET_OK; | ||
210 | } | ||
211 | if (one_shot == GNUNET_SYSERR) | ||
212 | { | ||
213 | /* cannot call callback again, but return value saying that | ||
214 | * we have another full message in the buffer */ | ||
215 | ret = GNUNET_NO; | ||
216 | goto copy; | ||
217 | } | ||
218 | if (one_shot == GNUNET_YES) | ||
219 | one_shot = GNUNET_SYSERR; | ||
220 | mst->off += want; | ||
221 | if (GNUNET_OK != | ||
222 | (cbret = mst->cb (mst->cb_cls, | ||
223 | hdr))) | ||
224 | { | ||
225 | if (GNUNET_SYSERR == cbret) | ||
226 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
227 | "Failure processing message of type %u and size %u\n", | ||
228 | ntohs (hdr->type), | ||
229 | ntohs (hdr->size)); | ||
230 | return GNUNET_SYSERR; | ||
231 | } | ||
232 | if (mst->off == mst->pos) | ||
233 | { | ||
234 | /* reset to beginning of buffer, it's free right now! */ | ||
235 | mst->off = 0; | ||
236 | mst->pos = 0; | ||
237 | } | ||
238 | } | ||
239 | GNUNET_assert (0 == mst->pos); | ||
240 | while (size > 0) | ||
241 | { | ||
242 | unsigned long offset = (unsigned long) buf; | ||
243 | bool need_align = (0 != (offset % ALIGN_FACTOR)); | ||
244 | |||
245 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
246 | "Server-mst has %u bytes left in inbound buffer\n", | ||
247 | (unsigned int) size); | ||
248 | if (size < sizeof(struct GNUNET_MessageHeader)) | ||
249 | break; | ||
250 | if (! need_align) | ||
251 | { | ||
252 | /* can try to do zero-copy and process directly from original buffer */ | ||
253 | hdr = (const struct GNUNET_MessageHeader *) buf; | ||
254 | want = ntohs (hdr->size); | ||
255 | if (want < sizeof(struct GNUNET_MessageHeader)) | ||
256 | { | ||
257 | GNUNET_break_op (0); | ||
258 | mst->off = 0; | ||
259 | return GNUNET_SYSERR; | ||
260 | } | ||
261 | if (size < want) | ||
262 | break; /* or not: buffer incomplete, so copy to private buffer... */ | ||
263 | if (one_shot == GNUNET_SYSERR) | ||
264 | { | ||
265 | /* cannot call callback again, but return value saying that | ||
266 | * we have another full message in the buffer */ | ||
267 | ret = GNUNET_NO; | ||
268 | goto copy; | ||
269 | } | ||
270 | if (GNUNET_YES == one_shot) | ||
271 | one_shot = GNUNET_SYSERR; | ||
272 | if (GNUNET_OK != | ||
273 | (cbret = mst->cb (mst->cb_cls, | ||
274 | hdr))) | ||
275 | { | ||
276 | if (GNUNET_SYSERR == cbret) | ||
277 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
278 | "Failure processing message of type %u and size %u\n", | ||
279 | ntohs (hdr->type), | ||
280 | ntohs (hdr->size)); | ||
281 | return GNUNET_SYSERR; | ||
282 | } | ||
283 | buf += want; | ||
284 | size -= want; | ||
285 | } | ||
286 | else | ||
287 | { | ||
288 | /* need to copy to private buffer to align; | ||
289 | * yes, we go a bit more spaghetti than usual here */ | ||
290 | goto do_align; | ||
291 | } | ||
292 | } | ||
293 | copy: | ||
294 | if ((size > 0) && (! purge)) | ||
295 | { | ||
296 | if (size + mst->pos > mst->curr_buf) | ||
297 | { | ||
298 | mst->hdr = GNUNET_realloc (mst->hdr, | ||
299 | size + mst->pos); | ||
300 | ibuf = (char *) mst->hdr; | ||
301 | mst->curr_buf = size + mst->pos; | ||
302 | } | ||
303 | GNUNET_assert (size + mst->pos <= mst->curr_buf); | ||
304 | GNUNET_memcpy (&ibuf[mst->pos], | ||
305 | buf, | ||
306 | size); | ||
307 | mst->pos += size; | ||
308 | } | ||
309 | if (purge) | ||
310 | { | ||
311 | mst->off = 0; | ||
312 | mst->pos = 0; | ||
313 | } | ||
314 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
315 | "Server-mst leaves %u (%u/%u) bytes in private buffer\n", | ||
316 | (unsigned int) (mst->pos - mst->off), | ||
317 | (unsigned int) mst->pos, | ||
318 | (unsigned int) mst->off); | ||
319 | return ret; | ||
320 | } | ||
321 | |||
322 | |||
323 | /** | ||
324 | * Add incoming data to the receive buffer and call the | ||
325 | * callback for all complete messages. | ||
326 | * | ||
327 | * @param mst tokenizer to use | ||
328 | * @param buf input data to add | ||
329 | * @param size number of bytes in @a buf | ||
330 | * @param purge should any excess bytes in the buffer be discarded | ||
331 | * (i.e. for packet-based services like UDP) | ||
332 | * @param one_shot only call callback once, keep rest of message in buffer | ||
333 | * @return #GNUNET_OK if we are done processing (need more data) | ||
334 | * #GNUNET_NO if one_shot was set and we have another message ready | ||
335 | * #GNUNET_SYSERR if the data stream is corrupt | ||
336 | */ | ||
337 | enum GNUNET_GenericReturnValue | ||
338 | GNUNET_MST_read (struct GNUNET_MessageStreamTokenizer *mst, | ||
339 | struct GNUNET_NETWORK_Handle *sock, | ||
340 | int purge, | ||
341 | int one_shot) | ||
342 | { | ||
343 | ssize_t ret; | ||
344 | size_t left; | ||
345 | char *buf; | ||
346 | |||
347 | left = mst->curr_buf - mst->pos; | ||
348 | buf = (char *) mst->hdr; | ||
349 | ret = GNUNET_NETWORK_socket_recv (sock, | ||
350 | &buf[mst->pos], | ||
351 | left); | ||
352 | if (-1 == ret) | ||
353 | { | ||
354 | if ((EAGAIN == errno) || | ||
355 | (EINTR == errno)) | ||
356 | return GNUNET_OK; | ||
357 | GNUNET_log_strerror (GNUNET_ERROR_TYPE_INFO, | ||
358 | "recv"); | ||
359 | return GNUNET_SYSERR; | ||
360 | } | ||
361 | if (0 == ret) | ||
362 | { | ||
363 | /* other side closed connection, treat as error */ | ||
364 | return GNUNET_SYSERR; | ||
365 | } | ||
366 | mst->pos += ret; | ||
367 | return GNUNET_MST_from_buffer (mst, | ||
368 | NULL, | ||
369 | 0, | ||
370 | purge, | ||
371 | one_shot); | ||
372 | } | ||
373 | |||
374 | |||
375 | /** | ||
376 | * Obtain the next message from the @a mst, assuming that | ||
377 | * there are more unprocessed messages in the internal buffer | ||
378 | * of the @a mst. | ||
379 | * | ||
380 | * @param mst tokenizer to use | ||
381 | * @param one_shot only call callback once, keep rest of message in buffer | ||
382 | * @return #GNUNET_OK if we are done processing (need more data) | ||
383 | * #GNUNET_NO if one_shot was set and we have another message ready | ||
384 | * #GNUNET_SYSERR if the data stream is corrupt | ||
385 | */ | ||
386 | enum GNUNET_GenericReturnValue | ||
387 | GNUNET_MST_next (struct GNUNET_MessageStreamTokenizer *mst, | ||
388 | int one_shot) | ||
389 | { | ||
390 | return GNUNET_MST_from_buffer (mst, | ||
391 | NULL, | ||
392 | 0, | ||
393 | GNUNET_NO, | ||
394 | one_shot); | ||
395 | } | ||
396 | |||
397 | |||
398 | /** | ||
399 | * Destroys a tokenizer. | ||
400 | * | ||
401 | * @param mst tokenizer to destroy | ||
402 | */ | ||
403 | void | ||
404 | GNUNET_MST_destroy (struct GNUNET_MessageStreamTokenizer *mst) | ||
405 | { | ||
406 | GNUNET_free (mst->hdr); | ||
407 | GNUNET_free (mst); | ||
408 | } | ||
409 | |||
410 | |||
411 | /* end of server_mst.c */ | ||