GNUnet 0.21.1
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
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
45{
50
54 void *cb_cls;
55
59 size_t curr_buf;
60
64 size_t off;
65
69 size_t pos;
70
75};
76
77
87 void *cb_cls)
88{
90
93 ret->curr_buf = GNUNET_MIN_MESSAGE_SIZE;
94 ret->cb = cb;
95 ret->cb_cls = cb_cls;
96 return ret;
97}
98
99
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);
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 {
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);
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)
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
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)
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 }
293copy:
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 }
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
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;
350 &buf[mst->pos],
351 left);
352 if (-1 == ret)
353 {
354 if ((EAGAIN == errno) ||
355 (EINTR == errno))
356 return GNUNET_OK;
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
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
403void
405{
406 GNUNET_free (mst->hdr);
407 GNUNET_free (mst);
408}
409
410
411/* end of server_mst.c */
static size_t do_align(size_t start_position, size_t end_position)
Given the start and end position of a block of data, return the end position of that data after align...
Definition: fs_directory.c:488
static int ret
Final status code.
Definition: gnunet-arm.c:94
#define GNUNET_MIN_MESSAGE_SIZE
Smallest supported message.
#define GNUNET_log(kind,...)
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
GNUNET_GenericReturnValue
Named constants for return values.
#define GNUNET_MIN(a, b)
@ GNUNET_OK
@ GNUNET_YES
@ GNUNET_NO
@ GNUNET_SYSERR
#define GNUNET_break_op(cond)
Use this for assertion violations caused by other peers (i.e.
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
#define GNUNET_log_strerror(level, cmd)
Log an error message at log-level 'level' that indicates a failure of the command 'cmd' with the mess...
@ GNUNET_ERROR_TYPE_WARNING
@ GNUNET_ERROR_TYPE_DEBUG
@ GNUNET_ERROR_TYPE_INFO
#define GNUNET_new(type)
Allocate a struct or union of the given type.
#define GNUNET_malloc(size)
Wrapper around malloc.
#define GNUNET_realloc(ptr, size)
Wrapper around realloc.
#define GNUNET_free(ptr)
Wrapper around free.
ssize_t GNUNET_NETWORK_socket_recv(const struct GNUNET_NETWORK_Handle *desc, void *buffer, size_t length)
Read data from a connected socket (always non-blocking).
Definition: network.c:716
int(* GNUNET_MessageTokenizerCallback)(void *cls, const struct GNUNET_MessageHeader *message)
Functions with this signature are called whenever a complete message is received by the tokenizer.
enum GNUNET_GenericReturnValue GNUNET_MST_next(struct GNUNET_MessageStreamTokenizer *mst, int one_shot)
Obtain the next message from the mst, assuming that there are more unprocessed messages in the intern...
Definition: mst.c:387
enum GNUNET_GenericReturnValue GNUNET_MST_from_buffer(struct GNUNET_MessageStreamTokenizer *mst, const char *buf, size_t size, int purge, int one_shot)
Add incoming data to the receive buffer and call the callback for all complete messages.
Definition: mst.c:101
struct GNUNET_MessageStreamTokenizer * GNUNET_MST_create(GNUNET_MessageTokenizerCallback cb, void *cb_cls)
Create a message stream tokenizer.
Definition: mst.c:86
void GNUNET_MST_destroy(struct GNUNET_MessageStreamTokenizer *mst)
Destroys a tokenizer.
Definition: mst.c:404
enum GNUNET_GenericReturnValue GNUNET_MST_read(struct GNUNET_MessageStreamTokenizer *mst, struct GNUNET_NETWORK_Handle *sock, int purge, int one_shot)
Add incoming data to the receive buffer and call the callback for all complete messages.
Definition: mst.c:338
#define ALIGN_FACTOR
Definition: mst.c:35
#define LOG(kind,...)
Definition: mst.c:38
static unsigned int size
Size of the "table".
Definition: peer.c:68
static struct GNUNET_TIME_Relative delta
Definition: speedup.c:36
Header for all communications.
uint16_t type
The type of the message (GNUNET_MESSAGE_TYPE_XXXX), in big-endian format.
uint16_t size
The length of the struct (in bytes, including the length field itself), in big-endian format.
Handle to a message stream tokenizer.
Definition: mst.c:45
size_t curr_buf
Size of the buffer (starting at hdr).
Definition: mst.c:59
size_t pos
How many bytes in buffer are valid right now?
Definition: mst.c:69
void * cb_cls
Closure for cb.
Definition: mst.c:54
struct GNUNET_MessageHeader * hdr
Beginning of the buffer.
Definition: mst.c:74
size_t off
How many bytes in buffer have we already processed?
Definition: mst.c:64
GNUNET_MessageTokenizerCallback cb
Function to call on completed messages.
Definition: mst.c:49
handle to a socket
Definition: network.c:53