GNUnet  0.10.x
tcp_server_mst_legacy.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2010 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 
27 #include "platform.h"
28 #include "gnunet_util_lib.h"
29 
30 
31 #if HAVE_UNALIGNED_64_ACCESS
32 #define ALIGN_FACTOR 4
33 #else
34 #define ALIGN_FACTOR 8
35 #endif
36 
37 
46 
50  void *cb_cls;
51 
55  size_t curr_buf;
56 
60  size_t off;
61 
65  size_t pos;
66 
71 };
72 
73 
74 
84  void *cb_cls)
85 {
87 
91  ret->cb = cb;
92  ret->cb_cls = cb_cls;
93  return ret;
94 }
95 
96 
112 int
114  void *client_identity,
115  const char *buf, size_t size,
116  int purge, int one_shot)
117 {
118  const struct GNUNET_MessageHeader *hdr;
119  size_t delta;
120  uint16_t want;
121  char *ibuf;
122  int need_align;
123  unsigned long offset;
124  int ret;
125 
126  GNUNET_assert(mst->off <= mst->pos);
127  GNUNET_assert(mst->pos <= mst->curr_buf);
129  "Server-mst receives %u bytes with %u bytes already in private buffer\n",
130  (unsigned int)size, (unsigned int)(mst->pos - mst->off));
131  ret = GNUNET_OK;
132  ibuf = (char *)mst->hdr;
133  while (mst->pos > 0)
134  {
135 do_align:
136  GNUNET_assert(mst->pos >= mst->off);
137  if ((mst->curr_buf - mst->off < sizeof(struct GNUNET_MessageHeader)) ||
138  (0 != (mst->off % ALIGN_FACTOR)))
139  {
140  /* need to align or need more space */
141  mst->pos -= mst->off;
142  memmove(ibuf, &ibuf[mst->off], mst->pos);
143  mst->off = 0;
144  }
145  if (mst->pos - mst->off < sizeof(struct GNUNET_MessageHeader))
146  {
147  delta =
148  GNUNET_MIN(sizeof(struct GNUNET_MessageHeader) -
149  (mst->pos - mst->off), size);
150  GNUNET_memcpy(&ibuf[mst->pos], buf, delta);
151  mst->pos += delta;
152  buf += delta;
153  size -= delta;
154  }
155  if (mst->pos - mst->off < sizeof(struct GNUNET_MessageHeader))
156  {
157  if (purge)
158  {
159  mst->off = 0;
160  mst->pos = 0;
161  }
162  return GNUNET_OK;
163  }
164  hdr = (const struct GNUNET_MessageHeader *)&ibuf[mst->off];
165  want = ntohs(hdr->size);
166  if (want < sizeof(struct GNUNET_MessageHeader))
167  {
168  GNUNET_break_op(0);
169  return GNUNET_SYSERR;
170  }
171  if ((mst->curr_buf - mst->off < want) &&
172  (mst->off > 0))
173  {
174  /* can get more space by moving */
175  mst->pos -= mst->off;
176  memmove(ibuf, &ibuf[mst->off], mst->pos);
177  mst->off = 0;
178  }
179  if (mst->curr_buf < want)
180  {
181  /* need to get more space by growing buffer */
182  GNUNET_assert(0 == mst->off);
183  mst->hdr = GNUNET_realloc(mst->hdr, want);
184  ibuf = (char *)mst->hdr;
185  mst->curr_buf = want;
186  }
187  hdr = (const struct GNUNET_MessageHeader *)&ibuf[mst->off];
188  if (mst->pos - mst->off < want)
189  {
190  delta = GNUNET_MIN(want - (mst->pos - mst->off), size);
191  GNUNET_assert(mst->pos + delta <= mst->curr_buf);
192  GNUNET_memcpy(&ibuf[mst->pos], buf, delta);
193  mst->pos += delta;
194  buf += delta;
195  size -= delta;
196  }
197  if (mst->pos - mst->off < want)
198  {
199  if (purge)
200  {
201  mst->off = 0;
202  mst->pos = 0;
203  }
204  return GNUNET_OK;
205  }
206  if (one_shot == GNUNET_SYSERR)
207  {
208  /* cannot call callback again, but return value saying that
209  * we have another full message in the buffer */
210  ret = GNUNET_NO;
211  goto copy;
212  }
213  if (one_shot == GNUNET_YES)
214  one_shot = GNUNET_SYSERR;
215  mst->off += want;
216  if (GNUNET_SYSERR == mst->cb(mst->cb_cls, client_identity, hdr))
217  return GNUNET_SYSERR;
218  if (mst->off == mst->pos)
219  {
220  /* reset to beginning of buffer, it's free right now! */
221  mst->off = 0;
222  mst->pos = 0;
223  }
224  }
225  GNUNET_assert(0 == mst->pos);
226  while (size > 0)
227  {
229  "Server-mst has %u bytes left in inbound buffer\n",
230  (unsigned int)size);
231  if (size < sizeof(struct GNUNET_MessageHeader))
232  break;
233  offset = (unsigned long)buf;
234  need_align = (0 != (offset % ALIGN_FACTOR)) ? GNUNET_YES : GNUNET_NO;
235  if (GNUNET_NO == need_align)
236  {
237  /* can try to do zero-copy and process directly from original buffer */
238  hdr = (const struct GNUNET_MessageHeader *)buf;
239  want = ntohs(hdr->size);
240  if (want < sizeof(struct GNUNET_MessageHeader))
241  {
242  GNUNET_break_op(0);
243  mst->off = 0;
244  return GNUNET_SYSERR;
245  }
246  if (size < want)
247  break; /* or not: buffer incomplete, so copy to private buffer... */
248  if (one_shot == GNUNET_SYSERR)
249  {
250  /* cannot call callback again, but return value saying that
251  * we have another full message in the buffer */
252  ret = GNUNET_NO;
253  goto copy;
254  }
255  if (one_shot == GNUNET_YES)
256  one_shot = GNUNET_SYSERR;
257  if (GNUNET_SYSERR == mst->cb(mst->cb_cls, client_identity, hdr))
258  return GNUNET_SYSERR;
259  buf += want;
260  size -= want;
261  }
262  else
263  {
264  /* need to copy to private buffer to align;
265  * yes, we go a bit more spagetti than usual here */
266  goto do_align;
267  }
268  }
269 copy:
270  if ((size > 0) && (!purge))
271  {
272  if (size + mst->pos > mst->curr_buf)
273  {
274  mst->hdr = GNUNET_realloc(mst->hdr, size + mst->pos);
275  ibuf = (char *)mst->hdr;
276  mst->curr_buf = size + mst->pos;
277  }
278  GNUNET_assert(size + mst->pos <= mst->curr_buf);
279  GNUNET_memcpy(&ibuf[mst->pos], buf, size);
280  mst->pos += size;
281  }
282  if (purge)
283  {
284  mst->off = 0;
285  mst->pos = 0;
286  }
288  "Server-mst leaves %u bytes in private buffer\n",
289  (unsigned int)(mst->pos - mst->off));
290  return ret;
291 }
292 
293 
299 void
301 {
302  GNUNET_free(mst->hdr);
303  GNUNET_free(mst);
304 }
305 
306 
307 
308 /* end of server_mst.c */
static struct GNUNET_TIME_Relative delta
Definition: speedup.c:35
#define ALIGN_FACTOR
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:480
#define LOG(kind,...)
Definition: arm_api.c:33
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
struct GNUNET_SERVER_MessageStreamTokenizer * GNUNET_SERVER_mst_create(GNUNET_SERVER_MessageTokenizerCallback cb, void *cb_cls)
Create a message stream tokenizer.
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
#define GNUNET_NO
Definition: gnunet_common.h:78
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
#define GNUNET_new(type)
Allocate a struct or union of the given type.
int GNUNET_SERVER_mst_receive(struct GNUNET_SERVER_MessageStreamTokenizer *mst, void *client_identity, 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.
size_t pos
How many bytes in buffer are valid right now?
uint16_t size
The length of the struct (in bytes, including the length field itself), in big-endian format...
static int ret
Final status code.
Definition: gnunet-arm.c:89
int(* GNUNET_SERVER_MessageTokenizerCallback)(void *cls, void *client, const struct GNUNET_MessageHeader *message)
Functions with this signature are called whenever a complete message is received by the tokenizer...
size_t off
How many bytes in buffer have we already processed?
Handle to a message stream tokenizer.
#define GNUNET_break_op(cond)
Use this for assertion violations caused by other peers (i.e.
#define GNUNET_realloc(ptr, size)
Wrapper around realloc.
#define GNUNET_MIN(a, b)
Definition: gnunet_common.h:80
static char buf[2048]
#define GNUNET_MIN_MESSAGE_SIZE
Smallest supported message.
#define GNUNET_SYSERR
Definition: gnunet_common.h:76
static unsigned int size
Size of the "table".
Definition: peer.c:66
struct GNUNET_MessageHeader * hdr
Beginning of the buffer.
GNUNET_SERVER_MessageTokenizerCallback cb
Function to call on completed messages.
size_t curr_buf
Size of the buffer (starting at hdr).
void GNUNET_SERVER_mst_destroy(struct GNUNET_SERVER_MessageStreamTokenizer *mst)
Destroys a tokenizer.
Header for all communications.
#define GNUNET_YES
Definition: gnunet_common.h:77
#define GNUNET_malloc(size)
Wrapper around malloc.
#define GNUNET_free(ptr)
Wrapper around free.