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8a67d61d | 1 | /** @file\r |
2 | \r | |
3 | Copyright (c) 2005 - 2006, Intel Corporation\r | |
4 | All rights reserved. This program and the accompanying materials\r | |
5 | are licensed and made available under the terms and conditions of the BSD License\r | |
6 | which accompanies this distribution. The full text of the license may be found at\r | |
7 | http://opensource.org/licenses/bsd-license.php\r | |
8 | \r | |
9 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
10 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
11 | \r | |
12 | Module Name:\r | |
13 | \r | |
14 | Tcp4Output.c\r | |
15 | \r | |
16 | Abstract:\r | |
17 | \r | |
18 | TCP output process routines.\r | |
19 | \r | |
20 | \r | |
21 | **/\r | |
22 | \r | |
23 | #include "Tcp4Main.h"\r | |
24 | \r | |
25 | STATIC UINT8 mTcpOutFlag[] = {\r | |
26 | 0, // TCP_CLOSED\r | |
27 | 0, // TCP_LISTEN\r | |
28 | TCP_FLG_SYN, // TCP_SYN_SENT\r | |
29 | TCP_FLG_SYN | TCP_FLG_ACK, // TCP_SYN_RCVD\r | |
30 | TCP_FLG_ACK, // TCP_ESTABLISHED\r | |
31 | TCP_FLG_FIN | TCP_FLG_ACK, // TCP_FIN_WAIT_1\r | |
32 | TCP_FLG_ACK, // TCP_FIN_WAIT_2\r | |
33 | TCP_FLG_ACK | TCP_FLG_FIN, // TCP_CLOSING\r | |
34 | TCP_FLG_ACK, // TCP_TIME_WAIT\r | |
35 | TCP_FLG_ACK, // TCP_CLOSE_WAIT\r | |
36 | TCP_FLG_FIN | TCP_FLG_ACK // TCP_LAST_ACK\r | |
37 | };\r | |
38 | \r | |
39 | \r | |
40 | /**\r | |
41 | Compute the sequence space left in the old receive window.\r | |
42 | \r | |
43 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
44 | \r | |
45 | @return The sequence space left in the old receive window.\r | |
46 | \r | |
47 | **/\r | |
48 | UINT32\r | |
49 | TcpRcvWinOld (\r | |
50 | IN TCP_CB *Tcb\r | |
51 | )\r | |
52 | {\r | |
53 | UINT32 OldWin;\r | |
54 | \r | |
55 | OldWin = 0;\r | |
56 | \r | |
57 | if (TCP_SEQ_GT (Tcb->RcvWl2 + Tcb->RcvWnd, Tcb->RcvNxt)) {\r | |
58 | \r | |
59 | OldWin = TCP_SUB_SEQ (\r | |
60 | Tcb->RcvWl2 + Tcb->RcvWnd,\r | |
61 | Tcb->RcvNxt\r | |
62 | );\r | |
63 | }\r | |
64 | \r | |
65 | return OldWin;\r | |
66 | }\r | |
67 | \r | |
68 | \r | |
69 | /**\r | |
70 | Compute the current receive window.\r | |
71 | \r | |
72 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
73 | \r | |
74 | @return The size of the current receive window, in bytes.\r | |
75 | \r | |
76 | **/\r | |
77 | UINT32\r | |
78 | TcpRcvWinNow (\r | |
79 | IN TCP_CB *Tcb\r | |
80 | )\r | |
81 | {\r | |
82 | SOCKET *Sk;\r | |
83 | UINT32 Win;\r | |
84 | UINT32 Increase;\r | |
85 | UINT32 OldWin;\r | |
86 | \r | |
87 | Sk = Tcb->Sk;\r | |
88 | ASSERT (Sk);\r | |
89 | \r | |
90 | OldWin = TcpRcvWinOld (Tcb);\r | |
91 | \r | |
92 | Win = SockGetFreeSpace (Sk, SOCK_RCV_BUF);\r | |
93 | \r | |
94 | Increase = 0;\r | |
95 | if (Win > OldWin) {\r | |
96 | Increase = Win - OldWin;\r | |
97 | }\r | |
98 | \r | |
99 | //\r | |
100 | // Receiver's SWS: don't advertise a bigger window\r | |
101 | // unless it can be increased by at least one Mss or\r | |
102 | // half of the receive buffer.\r | |
103 | //\r | |
104 | if ((Increase > Tcb->SndMss) ||\r | |
105 | (2 * Increase >= GET_RCV_BUFFSIZE (Sk))) {\r | |
106 | \r | |
107 | return Win;\r | |
108 | }\r | |
109 | \r | |
110 | return OldWin;\r | |
111 | }\r | |
112 | \r | |
113 | \r | |
114 | /**\r | |
115 | Compute the value to fill in the window size field\r | |
116 | of the outgoing segment.\r | |
117 | \r | |
118 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
119 | @param Syn The flag to indicate whether the outgoing segment is a SYN\r | |
120 | segment.\r | |
121 | \r | |
122 | @return The value of the local receive window size used to fill the outing segment.\r | |
123 | \r | |
124 | **/\r | |
125 | STATIC\r | |
126 | UINT16\r | |
127 | TcpComputeWnd (\r | |
128 | IN TCP_CB *Tcb,\r | |
129 | IN BOOLEAN Syn\r | |
130 | )\r | |
131 | {\r | |
132 | UINT32 Wnd;\r | |
133 | \r | |
134 | //\r | |
135 | // RFC requires that initial window not be scaled\r | |
136 | //\r | |
137 | if (Syn) {\r | |
138 | \r | |
139 | Wnd = GET_RCV_BUFFSIZE (Tcb->Sk);\r | |
140 | } else {\r | |
141 | \r | |
142 | Wnd = TcpRcvWinNow (Tcb);\r | |
143 | \r | |
144 | Tcb->RcvWnd = Wnd;\r | |
145 | }\r | |
146 | \r | |
147 | Wnd = NET_MIN (Wnd >> Tcb->RcvWndScale, 0xffff);\r | |
148 | return NTOHS ((UINT16) Wnd);\r | |
149 | }\r | |
150 | \r | |
151 | \r | |
152 | /**\r | |
153 | Get the maximum SndNxt.\r | |
154 | \r | |
155 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
156 | \r | |
157 | @return The sequence number of the maximum SndNxt.\r | |
158 | \r | |
159 | **/\r | |
160 | TCP_SEQNO\r | |
161 | TcpGetMaxSndNxt (\r | |
162 | IN TCP_CB *Tcb\r | |
163 | )\r | |
164 | {\r | |
165 | NET_LIST_ENTRY *Entry;\r | |
166 | NET_BUF *Nbuf;\r | |
167 | \r | |
168 | if (NetListIsEmpty (&Tcb->SndQue)) {\r | |
169 | return Tcb->SndNxt;\r | |
170 | }\r | |
171 | \r | |
172 | Entry = Tcb->SndQue.BackLink;\r | |
173 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r | |
174 | \r | |
175 | ASSERT (TCP_SEQ_GEQ (TCPSEG_NETBUF (Nbuf)->End, Tcb->SndNxt));\r | |
176 | return TCPSEG_NETBUF (Nbuf)->End;\r | |
177 | }\r | |
178 | \r | |
179 | \r | |
180 | /**\r | |
181 | Compute how much data to send.\r | |
182 | \r | |
183 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
184 | @param Force Whether to ignore the sender's SWS avoidance algorithm and send\r | |
185 | out data by force.\r | |
186 | \r | |
187 | @return The length of the data can be sent, if 0, no data can be sent.\r | |
188 | \r | |
189 | **/\r | |
190 | UINT32\r | |
191 | TcpDataToSend (\r | |
192 | IN TCP_CB *Tcb,\r | |
193 | IN INTN Force\r | |
194 | )\r | |
195 | {\r | |
196 | SOCKET *Sk;\r | |
197 | UINT32 Win;\r | |
198 | UINT32 Len;\r | |
199 | UINT32 Left;\r | |
200 | UINT32 Limit;\r | |
201 | \r | |
202 | Sk = Tcb->Sk;\r | |
203 | ASSERT (Sk);\r | |
204 | \r | |
205 | //\r | |
206 | // TCP should NOT send data beyond the send window\r | |
207 | // and congestion window. The right edge of send\r | |
208 | // window is defined as SND.WL2 + SND.WND. The right\r | |
209 | // edge of congestion window is defined as SND.UNA +\r | |
210 | // CWND.\r | |
211 | //\r | |
212 | Win = 0;\r | |
213 | Limit = Tcb->SndWl2 + Tcb->SndWnd;\r | |
214 | \r | |
215 | if (TCP_SEQ_GT (Limit, Tcb->SndUna + Tcb->CWnd)) {\r | |
216 | \r | |
217 | Limit = Tcb->SndUna + Tcb->CWnd;\r | |
218 | }\r | |
219 | \r | |
220 | if (TCP_SEQ_GT (Limit, Tcb->SndNxt)) {\r | |
221 | Win = TCP_SUB_SEQ (Limit, Tcb->SndNxt);\r | |
222 | }\r | |
223 | \r | |
224 | //\r | |
225 | // The data to send contains two parts: the data on the\r | |
226 | // socket send queue, and the data on the TCB's send\r | |
227 | // buffer. The later can be non-zero if the peer shrinks\r | |
228 | // its advertised window.\r | |
229 | //\r | |
230 | Left = GET_SND_DATASIZE (Sk) +\r | |
231 | TCP_SUB_SEQ (TcpGetMaxSndNxt (Tcb), Tcb->SndNxt);\r | |
232 | \r | |
233 | Len = NET_MIN (Win, Left);\r | |
234 | \r | |
235 | if (Len > Tcb->SndMss) {\r | |
236 | Len = Tcb->SndMss;\r | |
237 | }\r | |
238 | \r | |
239 | if (Force || (Len == 0 && Left == 0)) {\r | |
240 | return Len;\r | |
241 | }\r | |
242 | \r | |
243 | if (Len == 0 && Left != 0) {\r | |
244 | goto SetPersistTimer;\r | |
245 | }\r | |
246 | \r | |
247 | //\r | |
248 | // Sender's SWS avoidance: Don't send a small segment unless\r | |
249 | // a)A full-sized segment can be sent,\r | |
250 | // b)at least one-half of the maximum sized windows that\r | |
251 | // the other end has ever advertised.\r | |
252 | // c)It can send everything it has and either it isn't\r | |
253 | // expecting an ACK or the Nagle algorithm is disabled.\r | |
254 | //\r | |
255 | if ((Len == Tcb->SndMss) || (2 * Len >= Tcb->SndWndMax)) {\r | |
256 | \r | |
257 | return Len;\r | |
258 | }\r | |
259 | \r | |
260 | if ((Len == Left) &&\r | |
261 | ((Tcb->SndNxt == Tcb->SndUna) ||\r | |
262 | TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_NO_NAGLE))) {\r | |
263 | \r | |
264 | return Len;\r | |
265 | }\r | |
266 | \r | |
267 | //\r | |
268 | // RFC1122 suggests to set a timer when SWSA forbids TCP\r | |
269 | // sending more data, and combine it with probe timer.\r | |
270 | //\r | |
271 | SetPersistTimer:\r | |
272 | if (!TCP_TIMER_ON (Tcb->EnabledTimer, TCP_TIMER_REXMIT)) {\r | |
273 | \r | |
274 | TCP4_DEBUG_WARN (\r | |
275 | ("TcpDataToSend: enter persistent state for TCB %x\n",\r | |
276 | Tcb)\r | |
277 | );\r | |
278 | \r | |
279 | TcpSetProbeTimer (Tcb);\r | |
280 | }\r | |
281 | \r | |
282 | return 0;\r | |
283 | }\r | |
284 | \r | |
285 | \r | |
286 | /**\r | |
287 | Build the TCP header of the TCP segment and transmit the\r | |
288 | segment by IP.\r | |
289 | \r | |
290 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
291 | @param Nbuf Pointer to the buffer containing the segment to be sent out.\r | |
292 | \r | |
293 | @retval 0 The segment is sent out successfully.\r | |
294 | @retval other Error condition occurred.\r | |
295 | \r | |
296 | **/\r | |
297 | STATIC\r | |
298 | INTN\r | |
299 | TcpTransmitSegment (\r | |
300 | IN TCP_CB *Tcb,\r | |
301 | IN NET_BUF *Nbuf\r | |
302 | )\r | |
303 | {\r | |
304 | UINT16 Len;\r | |
305 | TCP_HEAD *Head;\r | |
306 | TCP_SEG *Seg;\r | |
307 | BOOLEAN Syn;\r | |
308 | UINT32 DataLen;\r | |
309 | \r | |
310 | ASSERT (Nbuf && (Nbuf->Tcp == NULL) && TcpVerifySegment (Nbuf));\r | |
311 | \r | |
312 | DataLen = Nbuf->TotalSize;\r | |
313 | \r | |
314 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
315 | Syn = TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN);\r | |
316 | \r | |
317 | if (Syn) {\r | |
318 | \r | |
319 | Len = TcpSynBuildOption (Tcb, Nbuf);\r | |
320 | } else {\r | |
321 | \r | |
322 | Len = TcpBuildOption (Tcb, Nbuf);\r | |
323 | }\r | |
324 | \r | |
325 | ASSERT ((Len % 4 == 0) && (Len <= 40));\r | |
326 | \r | |
327 | Len += sizeof (TCP_HEAD);\r | |
328 | \r | |
329 | Head = (TCP_HEAD *) NetbufAllocSpace (\r | |
330 | Nbuf,\r | |
331 | sizeof (TCP_HEAD),\r | |
332 | NET_BUF_HEAD\r | |
333 | );\r | |
334 | \r | |
335 | ASSERT (Head != NULL);\r | |
336 | \r | |
337 | Nbuf->Tcp = Head;\r | |
338 | \r | |
339 | Head->SrcPort = Tcb->LocalEnd.Port;\r | |
340 | Head->DstPort = Tcb->RemoteEnd.Port;\r | |
341 | Head->Seq = NTOHL (Seg->Seq);\r | |
342 | Head->Ack = NTOHL (Tcb->RcvNxt);\r | |
343 | Head->HeadLen = (UINT8) (Len >> 2);\r | |
344 | Head->Res = 0;\r | |
345 | Head->Wnd = TcpComputeWnd (Tcb, Syn);\r | |
346 | Head->Checksum = 0;\r | |
347 | \r | |
348 | //\r | |
349 | // Check whether to set the PSH flag.\r | |
350 | //\r | |
351 | TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_PSH);\r | |
352 | \r | |
353 | if (DataLen != 0) {\r | |
354 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_PSH) &&\r | |
355 | TCP_SEQ_BETWEEN (Seg->Seq, Tcb->SndPsh, Seg->End)) {\r | |
356 | \r | |
357 | TCP_SET_FLG (Seg->Flag, TCP_FLG_PSH);\r | |
358 | TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_SND_PSH);\r | |
359 | \r | |
360 | } else if ((Seg->End == Tcb->SndNxt) &&\r | |
361 | (GET_SND_DATASIZE (Tcb->Sk) == 0)) {\r | |
362 | \r | |
363 | TCP_SET_FLG (Seg->Flag, TCP_FLG_PSH);\r | |
364 | }\r | |
365 | }\r | |
366 | \r | |
367 | //\r | |
368 | // Check whether to set the URG flag and the urgent pointer.\r | |
369 | //\r | |
370 | TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_URG);\r | |
371 | \r | |
372 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_URG) &&\r | |
373 | TCP_SEQ_LEQ (Seg->Seq, Tcb->SndUp)) {\r | |
374 | \r | |
375 | TCP_SET_FLG (Seg->Flag, TCP_FLG_URG);\r | |
376 | \r | |
377 | if (TCP_SEQ_LT (Tcb->SndUp, Seg->End)) {\r | |
378 | \r | |
379 | Seg->Urg = (UINT16) TCP_SUB_SEQ (Tcb->SndUp, Seg->Seq);\r | |
380 | } else {\r | |
381 | \r | |
382 | Seg->Urg = (UINT16) NET_MIN (\r | |
383 | TCP_SUB_SEQ (Tcb->SndUp,\r | |
384 | Seg->Seq),\r | |
385 | 0xffff\r | |
386 | );\r | |
387 | }\r | |
388 | }\r | |
389 | \r | |
390 | Head->Flag = Seg->Flag;\r | |
391 | Head->Urg = NTOHS (Seg->Urg);\r | |
392 | Head->Checksum = TcpChecksum (Nbuf, Tcb->HeadSum);\r | |
393 | \r | |
394 | //\r | |
395 | // update the TCP session's control information\r | |
396 | //\r | |
397 | Tcb->RcvWl2 = Tcb->RcvNxt;\r | |
398 | if (Syn) {\r | |
399 | Tcb->RcvWnd = NTOHS (Head->Wnd);\r | |
400 | }\r | |
401 | \r | |
402 | //\r | |
403 | // clear delayedack flag\r | |
404 | //\r | |
405 | Tcb->DelayedAck = 0;\r | |
406 | \r | |
407 | return TcpSendIpPacket (Tcb, Nbuf, Tcb->LocalEnd.Ip, Tcb->RemoteEnd.Ip);\r | |
408 | }\r | |
409 | \r | |
410 | \r | |
411 | /**\r | |
412 | Get a segment from the Tcb's SndQue.\r | |
413 | \r | |
414 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
415 | @param Seq The sequence number of the segment.\r | |
416 | @param Len The maximum length of the segment.\r | |
417 | \r | |
418 | @return Pointer to the segment, if NULL some error occurred.\r | |
419 | \r | |
420 | **/\r | |
421 | NET_BUF *\r | |
422 | TcpGetSegmentSndQue (\r | |
423 | IN TCP_CB *Tcb,\r | |
424 | IN TCP_SEQNO Seq,\r | |
425 | IN UINT32 Len\r | |
426 | )\r | |
427 | {\r | |
428 | NET_LIST_ENTRY *Head;\r | |
429 | NET_LIST_ENTRY *Cur;\r | |
430 | NET_BUF *Node;\r | |
431 | TCP_SEG *Seg;\r | |
432 | NET_BUF *Nbuf;\r | |
433 | TCP_SEQNO End;\r | |
434 | UINT8 *Data;\r | |
435 | UINT8 Flag;\r | |
436 | INT32 Offset;\r | |
437 | INT32 CopyLen;\r | |
438 | \r | |
439 | ASSERT (Tcb && TCP_SEQ_LEQ (Seq, Tcb->SndNxt) && (Len > 0));\r | |
440 | \r | |
441 | //\r | |
442 | // Find the segment that contains the Seq.\r | |
443 | //\r | |
444 | Head = &Tcb->SndQue;\r | |
445 | \r | |
446 | Node = NULL;\r | |
447 | Seg = NULL;\r | |
448 | \r | |
449 | NET_LIST_FOR_EACH (Cur, Head) {\r | |
450 | Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);\r | |
451 | Seg = TCPSEG_NETBUF (Node);\r | |
452 | \r | |
453 | if (TCP_SEQ_LT (Seq, Seg->End) && TCP_SEQ_LEQ (Seg->Seq, Seq)) {\r | |
454 | \r | |
455 | break;\r | |
456 | }\r | |
457 | }\r | |
458 | \r | |
459 | ASSERT (Cur != Head);\r | |
460 | \r | |
461 | //\r | |
462 | // Return the buffer if it can be returned without\r | |
463 | // adjustment:\r | |
464 | //\r | |
465 | if ((Seg->Seq == Seq) &&\r | |
466 | TCP_SEQ_LEQ (Seg->End, Seg->Seq + Len) &&\r | |
467 | !NET_BUF_SHARED (Node)) {\r | |
468 | \r | |
469 | NET_GET_REF (Node);\r | |
470 | return Node;\r | |
471 | }\r | |
472 | \r | |
473 | //\r | |
474 | // Create a new buffer and copy data there.\r | |
475 | //\r | |
476 | Nbuf = NetbufAlloc (Len + TCP_MAX_HEAD);\r | |
477 | \r | |
478 | if (Nbuf == NULL) {\r | |
479 | return NULL;\r | |
480 | }\r | |
481 | \r | |
482 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r | |
483 | \r | |
484 | Flag = Seg->Flag;\r | |
485 | End = Seg->End;\r | |
486 | \r | |
487 | if (TCP_SEQ_LT (Seq + Len, Seg->End)) {\r | |
488 | End = Seq + Len;\r | |
489 | }\r | |
490 | \r | |
491 | CopyLen = TCP_SUB_SEQ (End, Seq);\r | |
492 | Offset = TCP_SUB_SEQ (Seq, Seg->Seq);\r | |
493 | \r | |
494 | //\r | |
495 | // If SYN is set and out of the range, clear the flag.\r | |
496 | // Becuase the sequence of the first byte is SEG.SEQ+1,\r | |
497 | // adjust Offset by -1. If SYN is in the range, copy\r | |
498 | // one byte less.\r | |
499 | //\r | |
500 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {\r | |
501 | \r | |
502 | if (TCP_SEQ_LT (Seg->Seq, Seq)) {\r | |
503 | \r | |
504 | TCP_CLEAR_FLG (Flag, TCP_FLG_SYN);\r | |
505 | Offset--;\r | |
506 | } else {\r | |
507 | \r | |
508 | CopyLen--;\r | |
509 | }\r | |
510 | }\r | |
511 | \r | |
512 | //\r | |
513 | // If FIN is set and in the range, copy one byte less,\r | |
514 | // and if it is out of the range, clear the flag.\r | |
515 | //\r | |
516 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {\r | |
517 | \r | |
518 | if (Seg->End == End) {\r | |
519 | \r | |
520 | CopyLen--;\r | |
521 | } else {\r | |
522 | \r | |
523 | TCP_CLEAR_FLG (Flag, TCP_FLG_FIN);\r | |
524 | }\r | |
525 | }\r | |
526 | \r | |
527 | ASSERT (CopyLen >= 0);\r | |
528 | \r | |
529 | //\r | |
530 | // copy data to the segment\r | |
531 | //\r | |
532 | if (CopyLen) {\r | |
533 | Data = NetbufAllocSpace (Nbuf, CopyLen, NET_BUF_TAIL);\r | |
534 | ASSERT (Data);\r | |
535 | \r | |
536 | if ((INT32) NetbufCopy (Node, Offset, CopyLen, Data) != CopyLen) {\r | |
537 | goto OnError;\r | |
538 | }\r | |
539 | }\r | |
540 | \r | |
541 | NetCopyMem (TCPSEG_NETBUF (Nbuf), Seg, sizeof (TCP_SEG));\r | |
542 | \r | |
543 | TCPSEG_NETBUF (Nbuf)->Seq = Seq;\r | |
544 | TCPSEG_NETBUF (Nbuf)->End = End;\r | |
545 | TCPSEG_NETBUF (Nbuf)->Flag = Flag;\r | |
546 | \r | |
547 | return Nbuf;\r | |
548 | \r | |
549 | OnError:\r | |
550 | NetbufFree (Nbuf);\r | |
551 | return NULL;\r | |
552 | }\r | |
553 | \r | |
554 | \r | |
555 | /**\r | |
556 | Get a segment from the Tcb's socket buffer.\r | |
557 | \r | |
558 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
559 | @param Seq The sequence number of the segment.\r | |
560 | @param Len The maximum length of the segment.\r | |
561 | \r | |
562 | @return Pointer to the segment, if NULL some error occurred.\r | |
563 | \r | |
564 | **/\r | |
565 | NET_BUF *\r | |
566 | TcpGetSegmentSock (\r | |
567 | IN TCP_CB *Tcb,\r | |
568 | IN TCP_SEQNO Seq,\r | |
569 | IN UINT32 Len\r | |
570 | )\r | |
571 | {\r | |
572 | NET_BUF *Nbuf;\r | |
573 | UINT8 *Data;\r | |
574 | UINT32 DataGet;\r | |
575 | \r | |
576 | ASSERT (Tcb && Tcb->Sk);\r | |
577 | \r | |
578 | Nbuf = NetbufAlloc (Len + TCP_MAX_HEAD);\r | |
579 | \r | |
580 | if (Nbuf == NULL) {\r | |
581 | TCP4_DEBUG_ERROR (("TcpGetSegmentSock: failed to allocate "\r | |
582 | "a netbuf for TCB %x\n",Tcb));\r | |
583 | \r | |
584 | return NULL;\r | |
585 | }\r | |
586 | \r | |
587 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r | |
588 | \r | |
589 | DataGet = 0;\r | |
590 | \r | |
591 | if (Len) {\r | |
592 | //\r | |
593 | // copy data to the segment.\r | |
594 | //\r | |
595 | Data = NetbufAllocSpace (Nbuf, Len, NET_BUF_TAIL);\r | |
596 | ASSERT (Data);\r | |
597 | \r | |
598 | DataGet = SockGetDataToSend (Tcb->Sk, 0, Len, Data);\r | |
599 | }\r | |
600 | \r | |
601 | NET_GET_REF (Nbuf);\r | |
602 | \r | |
603 | TCPSEG_NETBUF (Nbuf)->Seq = Seq;\r | |
604 | TCPSEG_NETBUF (Nbuf)->End = Seq + Len;\r | |
605 | \r | |
606 | NetListInsertTail (&(Tcb->SndQue), &(Nbuf->List));\r | |
607 | \r | |
608 | if (DataGet != 0) {\r | |
609 | \r | |
610 | SockDataSent (Tcb->Sk, DataGet);\r | |
611 | }\r | |
612 | \r | |
613 | return Nbuf;\r | |
614 | }\r | |
615 | \r | |
616 | \r | |
617 | /**\r | |
618 | Get a segment starting from sequence Seq of a maximum\r | |
619 | length of Len.\r | |
620 | \r | |
621 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
622 | @param Seq The sequence number of the segment.\r | |
623 | @param Len The maximum length of the segment.\r | |
624 | \r | |
625 | @return Pointer to the segment, if NULL some error occurred.\r | |
626 | \r | |
627 | **/\r | |
628 | NET_BUF *\r | |
629 | TcpGetSegment (\r | |
630 | IN TCP_CB *Tcb,\r | |
631 | IN TCP_SEQNO Seq,\r | |
632 | IN UINT32 Len\r | |
633 | )\r | |
634 | {\r | |
635 | NET_BUF *Nbuf;\r | |
636 | \r | |
637 | ASSERT (Tcb);\r | |
638 | \r | |
639 | //\r | |
640 | // Compare the SndNxt with the max sequence number sent.\r | |
641 | //\r | |
642 | if ((Len != 0) && TCP_SEQ_LT (Seq, TcpGetMaxSndNxt (Tcb))) {\r | |
643 | \r | |
644 | Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r | |
645 | } else {\r | |
646 | \r | |
647 | Nbuf = TcpGetSegmentSock (Tcb, Seq, Len);\r | |
648 | }\r | |
649 | \r | |
650 | ASSERT (TcpVerifySegment (Nbuf));\r | |
651 | return Nbuf;\r | |
652 | }\r | |
653 | \r | |
654 | \r | |
655 | /**\r | |
656 | Retransmit the segment from sequence Seq.\r | |
657 | \r | |
658 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
659 | @param Seq The sequence number of the segment to be retransmitted.\r | |
660 | \r | |
661 | @retval 0 Retransmission succeeded.\r | |
662 | @retval -1 Error condition occurred.\r | |
663 | \r | |
664 | **/\r | |
665 | INTN\r | |
666 | TcpRetransmit (\r | |
667 | IN TCP_CB *Tcb,\r | |
668 | IN TCP_SEQNO Seq\r | |
669 | )\r | |
670 | {\r | |
671 | NET_BUF *Nbuf;\r | |
672 | UINT32 Len;\r | |
673 | \r | |
674 | //\r | |
675 | // Compute the maxium length of retransmission. It is\r | |
676 | // limited by three factors:\r | |
677 | // 1. Less than SndMss\r | |
678 | // 2. must in the current send window\r | |
679 | // 3. will not change the boundaries of queued segments.\r | |
680 | //\r | |
681 | if (TCP_SEQ_LT (Tcb->SndWl2 + Tcb->SndWnd, Seq)) {\r | |
682 | TCP4_DEBUG_WARN (("TcpRetransmit: retransmission cancelled "\r | |
683 | "because send window too small for TCB %x\n", Tcb));\r | |
684 | \r | |
685 | return 0;\r | |
686 | }\r | |
687 | \r | |
688 | Len = TCP_SUB_SEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq);\r | |
689 | Len = NET_MIN (Len, Tcb->SndMss);\r | |
690 | \r | |
691 | Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r | |
692 | if (Nbuf == NULL) {\r | |
693 | return -1;\r | |
694 | }\r | |
695 | \r | |
696 | ASSERT (TcpVerifySegment (Nbuf));\r | |
697 | \r | |
698 | if (TcpTransmitSegment (Tcb, Nbuf) != 0) {\r | |
699 | goto OnError;\r | |
700 | }\r | |
701 | \r | |
702 | //\r | |
703 | // The retransmitted buffer may be on the SndQue,\r | |
704 | // trim TCP head because all the buffer on SndQue\r | |
705 | // are headless.\r | |
706 | //\r | |
707 | ASSERT (Nbuf->Tcp);\r | |
708 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r | |
709 | Nbuf->Tcp = NULL;\r | |
710 | \r | |
711 | NetbufFree (Nbuf);\r | |
712 | return 0;\r | |
713 | \r | |
714 | OnError:\r | |
715 | if (Nbuf != NULL) {\r | |
716 | NetbufFree (Nbuf);\r | |
717 | }\r | |
718 | \r | |
719 | return -1;\r | |
720 | }\r | |
721 | \r | |
722 | \r | |
723 | /**\r | |
724 | Check whether to send data/SYN/FIN and piggy back an ACK.\r | |
725 | \r | |
726 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
727 | @param Force Whether to ignore the sender's SWS avoidance algorithm and send\r | |
728 | out data by force.\r | |
729 | \r | |
730 | @return The number of bytes sent.\r | |
731 | \r | |
732 | **/\r | |
733 | INTN\r | |
734 | TcpToSendData (\r | |
735 | IN TCP_CB *Tcb,\r | |
736 | IN INTN Force\r | |
737 | )\r | |
738 | {\r | |
739 | UINT32 Len;\r | |
740 | INTN Sent;\r | |
741 | UINT8 Flag;\r | |
742 | NET_BUF *Nbuf;\r | |
743 | TCP_SEG *Seg;\r | |
744 | TCP_SEQNO Seq;\r | |
745 | TCP_SEQNO End;\r | |
746 | \r | |
747 | ASSERT (Tcb && Tcb->Sk && (Tcb->State != TCP_LISTEN));\r | |
748 | \r | |
749 | Sent = 0;\r | |
750 | \r | |
751 | if ((Tcb->State == TCP_CLOSED) ||\r | |
752 | TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT)) {\r | |
753 | \r | |
754 | return 0;\r | |
755 | }\r | |
756 | \r | |
757 | SEND_AGAIN:\r | |
758 | //\r | |
759 | // compute how much data can be sent\r | |
760 | //\r | |
761 | Len = TcpDataToSend (Tcb, Force);\r | |
762 | Seq = Tcb->SndNxt;\r | |
763 | \r | |
764 | Flag = mTcpOutFlag[Tcb->State];\r | |
765 | \r | |
766 | if (Flag & TCP_FLG_SYN) {\r | |
767 | \r | |
768 | Seq = Tcb->Iss;\r | |
769 | Len = 0;\r | |
770 | }\r | |
771 | \r | |
772 | //\r | |
773 | // only send a segment without data if SYN or\r | |
774 | // FIN is set.\r | |
775 | //\r | |
776 | if ((Len == 0) && !(Flag & (TCP_FLG_SYN | TCP_FLG_FIN))) {\r | |
777 | return Sent;\r | |
778 | }\r | |
779 | \r | |
780 | Nbuf = TcpGetSegment (Tcb, Seq, Len);\r | |
781 | \r | |
782 | if (Nbuf == NULL) {\r | |
783 | TCP4_DEBUG_ERROR (\r | |
784 | ("TcpToSendData: failed to get a segment for TCB %x\n",\r | |
785 | Tcb)\r | |
786 | );\r | |
787 | \r | |
788 | goto OnError;\r | |
789 | }\r | |
790 | \r | |
791 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
792 | \r | |
793 | //\r | |
794 | // Set the TcpSeg in Nbuf.\r | |
795 | //\r | |
796 | Len = Nbuf->TotalSize;\r | |
797 | End = Seq + Len;\r | |
798 | if (TCP_FLG_ON (Flag, TCP_FLG_SYN)) {\r | |
799 | End++;\r | |
800 | }\r | |
801 | \r | |
802 | if (Flag & TCP_FLG_FIN) {\r | |
803 | //\r | |
804 | // Send FIN if all data is sent, and FIN is\r | |
805 | // in the window\r | |
806 | //\r | |
807 | if ((TcpGetMaxSndNxt (Tcb) == Tcb->SndNxt) &&\r | |
808 | (GET_SND_DATASIZE (Tcb->Sk) == 0) &&\r | |
809 | TCP_SEQ_LT (End + 1, Tcb->SndWnd + Tcb->SndWl2)\r | |
810 | ) {\r | |
811 | \r | |
812 | TCP4_DEBUG_TRACE (("TcpToSendData: send FIN "\r | |
813 | "to peer for TCB %x in state %d\n", Tcb, Tcb->State));\r | |
814 | \r | |
815 | End++;\r | |
816 | } else {\r | |
817 | TCP_CLEAR_FLG (Flag, TCP_FLG_FIN);\r | |
818 | }\r | |
819 | }\r | |
820 | \r | |
821 | Seg->Seq = Seq;\r | |
822 | Seg->End = End;\r | |
823 | Seg->Flag = Flag;\r | |
824 | \r | |
825 | ASSERT (TcpVerifySegment (Nbuf));\r | |
826 | ASSERT (TcpCheckSndQue (&Tcb->SndQue));\r | |
827 | \r | |
828 | //\r | |
829 | // don't send an empty segment here.\r | |
830 | //\r | |
831 | if (Seg->End == Seg->Seq) {\r | |
832 | TCP4_DEBUG_WARN (("TcpToSendData: created a empty"\r | |
833 | " segment for TCB %x, free it now\n", Tcb));\r | |
834 | \r | |
835 | NetbufFree (Nbuf);\r | |
836 | return Sent;\r | |
837 | }\r | |
838 | \r | |
839 | if (TcpTransmitSegment (Tcb, Nbuf) != 0) {\r | |
840 | //\r | |
841 | // TODO: double check this\r | |
842 | //\r | |
843 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r | |
844 | Nbuf->Tcp = NULL;\r | |
845 | \r | |
846 | if (Flag & TCP_FLG_FIN) {\r | |
847 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT);\r | |
848 | }\r | |
849 | \r | |
850 | goto OnError;\r | |
851 | }\r | |
852 | \r | |
853 | Sent += TCP_SUB_SEQ (End, Seq);\r | |
854 | \r | |
855 | //\r | |
856 | // All the buffer in the SndQue is headless\r | |
857 | //\r | |
858 | ASSERT (Nbuf->Tcp);\r | |
859 | \r | |
860 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r | |
861 | Nbuf->Tcp = NULL;\r | |
862 | \r | |
863 | NetbufFree (Nbuf);\r | |
864 | \r | |
865 | //\r | |
866 | // update status in TCB\r | |
867 | //\r | |
868 | Tcb->DelayedAck = 0;\r | |
869 | \r | |
870 | if (Flag & TCP_FLG_FIN) {\r | |
871 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT);\r | |
872 | }\r | |
873 | \r | |
874 | if (TCP_SEQ_GT (End, Tcb->SndNxt)) {\r | |
875 | Tcb->SndNxt = End;\r | |
876 | }\r | |
877 | \r | |
878 | if (!TCP_TIMER_ON (Tcb->EnabledTimer, TCP_TIMER_REXMIT)) {\r | |
879 | TcpSetTimer (Tcb, TCP_TIMER_REXMIT, Tcb->Rto);\r | |
880 | }\r | |
881 | \r | |
882 | //\r | |
883 | // Enable RTT measurement only if not in retransmit.\r | |
884 | // Karn's algorithm reqires not to update RTT when in loss.\r | |
885 | //\r | |
886 | if ((Tcb->CongestState == TCP_CONGEST_OPEN) &&\r | |
887 | !TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {\r | |
888 | \r | |
889 | TCP4_DEBUG_TRACE (("TcpToSendData: set RTT measure "\r | |
890 | "sequence %d for TCB %x\n", Seq, Tcb));\r | |
891 | \r | |
892 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);\r | |
893 | Tcb->RttSeq = Seq;\r | |
894 | Tcb->RttMeasure = 0;\r | |
895 | }\r | |
896 | \r | |
897 | if (Len == Tcb->SndMss) {\r | |
898 | goto SEND_AGAIN;\r | |
899 | }\r | |
900 | \r | |
901 | return Sent;\r | |
902 | \r | |
903 | OnError:\r | |
904 | if (Nbuf != NULL) {\r | |
905 | NetbufFree (Nbuf);\r | |
906 | }\r | |
907 | \r | |
908 | return Sent;\r | |
909 | }\r | |
910 | \r | |
911 | \r | |
912 | /**\r | |
913 | Send an ACK immediately.\r | |
914 | \r | |
915 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
916 | \r | |
917 | @return None.\r | |
918 | \r | |
919 | **/\r | |
920 | VOID\r | |
921 | TcpSendAck (\r | |
922 | IN TCP_CB *Tcb\r | |
923 | )\r | |
924 | {\r | |
925 | NET_BUF *Nbuf;\r | |
926 | TCP_SEG *Seg;\r | |
927 | \r | |
928 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r | |
929 | \r | |
930 | if (Nbuf == NULL) {\r | |
931 | return;\r | |
932 | }\r | |
933 | \r | |
934 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r | |
935 | \r | |
936 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
937 | Seg->Seq = Tcb->SndNxt;\r | |
938 | Seg->End = Tcb->SndNxt;\r | |
939 | Seg->Flag = TCP_FLG_ACK;\r | |
940 | \r | |
941 | if (TcpTransmitSegment (Tcb, Nbuf) == 0) {\r | |
942 | TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);\r | |
943 | Tcb->DelayedAck = 0;\r | |
944 | }\r | |
945 | \r | |
946 | NetbufFree (Nbuf);\r | |
947 | }\r | |
948 | \r | |
949 | \r | |
950 | /**\r | |
951 | Send a zero probe segment. It can be used by keepalive\r | |
952 | and zero window probe.\r | |
953 | \r | |
954 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
955 | \r | |
956 | @retval 0 The zero probe segment was sent out successfully.\r | |
957 | @retval other Error condition occurred.\r | |
958 | \r | |
959 | **/\r | |
960 | INTN\r | |
961 | TcpSendZeroProbe (\r | |
962 | IN TCP_CB *Tcb\r | |
963 | )\r | |
964 | {\r | |
965 | NET_BUF *Nbuf;\r | |
966 | TCP_SEG *Seg;\r | |
967 | INTN Result;\r | |
968 | \r | |
969 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r | |
970 | \r | |
971 | if (Nbuf == NULL) {\r | |
972 | return -1;\r | |
973 | }\r | |
974 | \r | |
975 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r | |
976 | \r | |
977 | //\r | |
978 | // SndNxt-1 is out of window. The peer should respond\r | |
979 | // with an ACK.\r | |
980 | //\r | |
981 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
982 | Seg->Seq = Tcb->SndNxt - 1;\r | |
983 | Seg->End = Tcb->SndNxt - 1;\r | |
984 | Seg->Flag = TCP_FLG_ACK;\r | |
985 | \r | |
986 | Result = TcpTransmitSegment (Tcb, Nbuf);\r | |
987 | NetbufFree (Nbuf);\r | |
988 | \r | |
989 | return Result;\r | |
990 | }\r | |
991 | \r | |
992 | \r | |
993 | /**\r | |
994 | Check whether to send an ACK or delayed ACK.\r | |
995 | \r | |
996 | @param Tcb Pointer to the TCP_CB of this TCP instance.\r | |
997 | \r | |
998 | @return None.\r | |
999 | \r | |
1000 | **/\r | |
1001 | VOID\r | |
1002 | TcpToSendAck (\r | |
1003 | IN TCP_CB *Tcb\r | |
1004 | )\r | |
1005 | {\r | |
4eb65aff | 1006 | UINT32 TcpNow;\r |
1007 | \r | |
1008 | TcpNow = TcpRcvWinNow (Tcb);\r | |
8a67d61d | 1009 | //\r |
1010 | // Generally, TCP should send a delayed ACK unless:\r | |
1011 | // 1. ACK at least every other FULL sized segment received,\r | |
1012 | // 2. Packets received out of order\r | |
1013 | // 3. Receiving window is open\r | |
1014 | //\r | |
1015 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW) ||\r | |
1016 | (Tcb->DelayedAck >= 1) ||\r | |
4eb65aff | 1017 | (TcpNow > TcpRcvWinOld (Tcb))\r |
8a67d61d | 1018 | ) {\r |
1019 | TcpSendAck (Tcb);\r | |
1020 | return;\r | |
1021 | }\r | |
1022 | \r | |
1023 | TCP4_DEBUG_TRACE (("TcpToSendAck: scheduled a delayed"\r | |
1024 | " ACK for TCB %x\n", Tcb));\r | |
1025 | \r | |
1026 | //\r | |
1027 | // schedule a delayed ACK\r | |
1028 | //\r | |
1029 | Tcb->DelayedAck++;\r | |
1030 | }\r | |
1031 | \r | |
1032 | \r | |
1033 | /**\r | |
1034 | Send a RESET segment in response to the segment received.\r | |
1035 | \r | |
1036 | @param Tcb Pointer to the TCP_CB of this TCP instance, may be NULL.\r | |
1037 | @param Head TCP header of the segment that triggers the reset.\r | |
1038 | @param Len Length of the segment that triggers the reset.\r | |
1039 | @param Local Local IP address.\r | |
1040 | @param Remote Remote peer's IP address.\r | |
1041 | \r | |
1042 | @retval 0 A reset is sent or no need to send it.\r | |
1043 | @retval -1 No reset is sent.\r | |
1044 | \r | |
1045 | **/\r | |
1046 | INTN\r | |
1047 | TcpSendReset (\r | |
1048 | IN TCP_CB *Tcb,\r | |
1049 | IN TCP_HEAD *Head,\r | |
1050 | IN INT32 Len,\r | |
1051 | IN UINT32 Local,\r | |
1052 | IN UINT32 Remote\r | |
1053 | )\r | |
1054 | {\r | |
1055 | NET_BUF *Nbuf;\r | |
1056 | TCP_HEAD *Nhead;\r | |
1057 | UINT16 HeadSum;\r | |
1058 | \r | |
1059 | //\r | |
1060 | // Don't respond to a Reset with reset\r | |
1061 | //\r | |
1062 | if (Head->Flag & TCP_FLG_RST) {\r | |
1063 | return 0;\r | |
1064 | }\r | |
1065 | \r | |
1066 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r | |
1067 | \r | |
1068 | if (Nbuf == NULL) {\r | |
1069 | return -1;\r | |
1070 | }\r | |
1071 | \r | |
1072 | Nhead = (TCP_HEAD *) NetbufAllocSpace (\r | |
1073 | Nbuf,\r | |
1074 | sizeof (TCP_HEAD),\r | |
1075 | NET_BUF_TAIL\r | |
1076 | );\r | |
1077 | \r | |
1078 | ASSERT (Nhead != NULL);\r | |
1079 | \r | |
1080 | Nbuf->Tcp = Nhead;\r | |
1081 | Nhead->Flag = TCP_FLG_RST;\r | |
1082 | \r | |
1083 | //\r | |
1084 | // Derive Seq/ACK from the segment if no TCB\r | |
1085 | // associated with it, otherwise from the Tcb\r | |
1086 | //\r | |
1087 | if (Tcb == NULL) {\r | |
1088 | \r | |
1089 | if (TCP_FLG_ON (Head->Flag, TCP_FLG_ACK)) {\r | |
1090 | Nhead->Seq = Head->Ack;\r | |
1091 | Nhead->Ack = 0;\r | |
1092 | } else {\r | |
1093 | Nhead->Seq = 0;\r | |
1094 | TCP_SET_FLG (Nhead->Flag, TCP_FLG_ACK);\r | |
1095 | Nhead->Ack = HTONL (NTOHL (Head->Seq) + Len);\r | |
1096 | }\r | |
1097 | } else {\r | |
1098 | \r | |
1099 | Nhead->Seq = HTONL (Tcb->SndNxt);\r | |
1100 | Nhead->Ack = HTONL (Tcb->RcvNxt);\r | |
1101 | TCP_SET_FLG (Nhead->Flag, TCP_FLG_ACK);\r | |
1102 | }\r | |
1103 | \r | |
1104 | Nhead->SrcPort = Head->DstPort;\r | |
1105 | Nhead->DstPort = Head->SrcPort;\r | |
1106 | Nhead->HeadLen = (sizeof (TCP_HEAD) >> 2);\r | |
1107 | Nhead->Res = 0;\r | |
1108 | Nhead->Wnd = HTONS (0xFFFF);\r | |
1109 | Nhead->Checksum = 0;\r | |
1110 | Nhead->Urg = 0;\r | |
1111 | \r | |
1112 | HeadSum = NetPseudoHeadChecksum (Local, Remote, 6, 0);\r | |
1113 | Nhead->Checksum = TcpChecksum (Nbuf, HeadSum);\r | |
1114 | \r | |
1115 | TcpSendIpPacket (Tcb, Nbuf, Local, Remote);\r | |
1116 | \r | |
1117 | NetbufFree (Nbuf);\r | |
1118 | return 0;\r | |
1119 | }\r | |
1120 | \r | |
1121 | \r | |
1122 | /**\r | |
1123 | Verify that the segment is in good shape.\r | |
1124 | \r | |
1125 | @param Nbuf Buffer that contains the segment to be checked.\r | |
1126 | \r | |
1127 | @retval 0 The segment is broken.\r | |
1128 | @retval 1 The segment is in good shape.\r | |
1129 | \r | |
1130 | **/\r | |
1131 | INTN\r | |
1132 | TcpVerifySegment (\r | |
1133 | IN NET_BUF *Nbuf\r | |
1134 | )\r | |
1135 | {\r | |
1136 | TCP_HEAD *Head;\r | |
1137 | TCP_SEG *Seg;\r | |
1138 | UINT32 Len;\r | |
1139 | \r | |
1140 | if (Nbuf == NULL) {\r | |
1141 | return 1;\r | |
1142 | }\r | |
1143 | \r | |
1144 | NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE);\r | |
1145 | \r | |
1146 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
1147 | Len = Nbuf->TotalSize;\r | |
1148 | Head = Nbuf->Tcp;\r | |
1149 | \r | |
1150 | if (Head != NULL) {\r | |
1151 | if (Head->Flag != Seg->Flag) {\r | |
1152 | return 0;\r | |
1153 | }\r | |
1154 | \r | |
1155 | Len -= (Head->HeadLen << 2);\r | |
1156 | }\r | |
1157 | \r | |
1158 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {\r | |
1159 | Len++;\r | |
1160 | }\r | |
1161 | \r | |
1162 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {\r | |
1163 | Len++;\r | |
1164 | }\r | |
1165 | \r | |
1166 | if (Seg->Seq + Len != Seg->End) {\r | |
1167 | return 0;\r | |
1168 | }\r | |
1169 | \r | |
1170 | return 1;\r | |
1171 | }\r | |
1172 | \r | |
1173 | \r | |
1174 | /**\r | |
1175 | Verify that all the segments in SndQue are in good shape.\r | |
1176 | \r | |
1177 | @param Head Pointer to the head node of the SndQue.\r | |
1178 | \r | |
1179 | @retval 0 At least one segment is broken.\r | |
1180 | @retval 1 All segments in the specific queue are in good shape.\r | |
1181 | \r | |
1182 | **/\r | |
1183 | INTN\r | |
1184 | TcpCheckSndQue (\r | |
1185 | IN NET_LIST_ENTRY *Head\r | |
1186 | )\r | |
1187 | {\r | |
1188 | NET_LIST_ENTRY *Entry;\r | |
1189 | NET_BUF *Nbuf;\r | |
1190 | TCP_SEQNO Seq;\r | |
1191 | \r | |
1192 | if (NetListIsEmpty (Head)) {\r | |
1193 | return 1;\r | |
1194 | }\r | |
1195 | //\r | |
1196 | // Initialize the Seq\r | |
1197 | //\r | |
1198 | Entry = Head->ForwardLink;\r | |
1199 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r | |
1200 | Seq = TCPSEG_NETBUF (Nbuf)->Seq;\r | |
1201 | \r | |
1202 | NET_LIST_FOR_EACH (Entry, Head) {\r | |
1203 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r | |
1204 | \r | |
1205 | if (TcpVerifySegment (Nbuf) == 0) {\r | |
1206 | return 0;\r | |
1207 | }\r | |
1208 | \r | |
1209 | //\r | |
1210 | // All the node in the SndQue should has:\r | |
1211 | // SEG.SEQ = LAST_SEG.END\r | |
1212 | //\r | |
1213 | if (Seq != TCPSEG_NETBUF (Nbuf)->Seq) {\r | |
1214 | return 0;\r | |
1215 | }\r | |
1216 | \r | |
1217 | Seq = TCPSEG_NETBUF (Nbuf)->End;\r | |
1218 | }\r | |
1219 | \r | |
1220 | return 1;\r | |
1221 | }\r |