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1 | /** @file\r | |
2 | TCP output process routines.\r | |
3 | \r | |
4 | Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>\r | |
5 | \r | |
6 | This program and the accompanying materials\r | |
7 | are licensed and made available under the terms and conditions of the BSD License\r | |
8 | which accompanies this distribution. The full text of the license may be found at\r | |
9 | http://opensource.org/licenses/bsd-license.php.\r | |
10 | \r | |
11 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
12 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
13 | \r | |
14 | **/\r | |
15 | \r | |
16 | #include "TcpMain.h"\r | |
17 | \r | |
18 | UINT8 mTcpOutFlag[] = {\r | |
19 | 0, // TCP_CLOSED\r | |
20 | 0, // TCP_LISTEN\r | |
21 | TCP_FLG_SYN, // TCP_SYN_SENT\r | |
22 | TCP_FLG_SYN | TCP_FLG_ACK, // TCP_SYN_RCVD\r | |
23 | TCP_FLG_ACK, // TCP_ESTABLISHED\r | |
24 | TCP_FLG_FIN | TCP_FLG_ACK, // TCP_FIN_WAIT_1\r | |
25 | TCP_FLG_ACK, // TCP_FIN_WAIT_2\r | |
26 | TCP_FLG_ACK | TCP_FLG_FIN, // TCP_CLOSING\r | |
27 | TCP_FLG_ACK, // TCP_TIME_WAIT\r | |
28 | TCP_FLG_ACK, // TCP_CLOSE_WAIT\r | |
29 | TCP_FLG_FIN | TCP_FLG_ACK // TCP_LAST_ACK\r | |
30 | };\r | |
31 | \r | |
32 | /**\r | |
33 | Compute the sequence space left in the old receive window.\r | |
34 | \r | |
35 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
36 | \r | |
37 | @return The sequence space left in the old receive window.\r | |
38 | \r | |
39 | **/\r | |
40 | UINT32\r | |
41 | TcpRcvWinOld (\r | |
42 | IN TCP_CB *Tcb\r | |
43 | )\r | |
44 | {\r | |
45 | UINT32 OldWin;\r | |
46 | \r | |
47 | OldWin = 0;\r | |
48 | \r | |
49 | if (TCP_SEQ_GT (Tcb->RcvWl2 + Tcb->RcvWnd, Tcb->RcvNxt)) {\r | |
50 | \r | |
51 | OldWin = TCP_SUB_SEQ (\r | |
52 | Tcb->RcvWl2 + Tcb->RcvWnd,\r | |
53 | Tcb->RcvNxt\r | |
54 | );\r | |
55 | }\r | |
56 | \r | |
57 | return OldWin;\r | |
58 | }\r | |
59 | \r | |
60 | /**\r | |
61 | Compute the current receive window.\r | |
62 | \r | |
63 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
64 | \r | |
65 | @return The size of the current receive window, in bytes.\r | |
66 | \r | |
67 | **/\r | |
68 | UINT32\r | |
69 | TcpRcvWinNow (\r | |
70 | IN TCP_CB *Tcb\r | |
71 | )\r | |
72 | {\r | |
73 | SOCKET *Sk;\r | |
74 | UINT32 Win;\r | |
75 | UINT32 Increase;\r | |
76 | UINT32 OldWin;\r | |
77 | \r | |
78 | Sk = Tcb->Sk;\r | |
79 | ASSERT (Sk != NULL);\r | |
80 | \r | |
81 | OldWin = TcpRcvWinOld (Tcb);\r | |
82 | \r | |
83 | Win = SockGetFreeSpace (Sk, SOCK_RCV_BUF);\r | |
84 | \r | |
85 | Increase = 0;\r | |
86 | if (Win > OldWin) {\r | |
87 | Increase = Win - OldWin;\r | |
88 | }\r | |
89 | \r | |
90 | //\r | |
91 | // Receiver's SWS: don't advertise a bigger window\r | |
92 | // unless it can be increased by at least one Mss or\r | |
93 | // half of the receive buffer.\r | |
94 | //\r | |
95 | if ((Increase > Tcb->SndMss) || (2 * Increase >= GET_RCV_BUFFSIZE (Sk))) {\r | |
96 | \r | |
97 | return Win;\r | |
98 | }\r | |
99 | \r | |
100 | return OldWin;\r | |
101 | }\r | |
102 | \r | |
103 | /**\r | |
104 | Compute the value to fill in the window size field of the outgoing segment.\r | |
105 | \r | |
106 | @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
107 | @param[in] Syn The flag to indicate whether the outgoing segment\r | |
108 | is a SYN segment.\r | |
109 | \r | |
110 | @return The value of the local receive window size used to fill the outgoing segment.\r | |
111 | \r | |
112 | **/\r | |
113 | UINT16\r | |
114 | TcpComputeWnd (\r | |
115 | IN OUT TCP_CB *Tcb,\r | |
116 | IN BOOLEAN Syn\r | |
117 | )\r | |
118 | {\r | |
119 | UINT32 Wnd;\r | |
120 | \r | |
121 | //\r | |
122 | // RFC requires that initial window not be scaled\r | |
123 | //\r | |
124 | if (Syn) {\r | |
125 | \r | |
126 | Wnd = GET_RCV_BUFFSIZE (Tcb->Sk);\r | |
127 | } else {\r | |
128 | \r | |
129 | Wnd = TcpRcvWinNow (Tcb);\r | |
130 | \r | |
131 | Tcb->RcvWnd = Wnd;\r | |
132 | }\r | |
133 | \r | |
134 | Wnd = MIN (Wnd >> Tcb->RcvWndScale, 0xffff);\r | |
135 | return NTOHS ((UINT16) Wnd);\r | |
136 | }\r | |
137 | \r | |
138 | /**\r | |
139 | Get the maximum SndNxt.\r | |
140 | \r | |
141 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
142 | \r | |
143 | @return The sequence number of the maximum SndNxt.\r | |
144 | \r | |
145 | **/\r | |
146 | TCP_SEQNO\r | |
147 | TcpGetMaxSndNxt (\r | |
148 | IN TCP_CB *Tcb\r | |
149 | )\r | |
150 | {\r | |
151 | LIST_ENTRY *Entry;\r | |
152 | NET_BUF *Nbuf;\r | |
153 | \r | |
154 | if (IsListEmpty (&Tcb->SndQue)) {\r | |
155 | return Tcb->SndNxt;\r | |
156 | }\r | |
157 | \r | |
158 | Entry = Tcb->SndQue.BackLink;\r | |
159 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r | |
160 | \r | |
161 | ASSERT (TCP_SEQ_GEQ (TCPSEG_NETBUF (Nbuf)->End, Tcb->SndNxt));\r | |
162 | return TCPSEG_NETBUF (Nbuf)->End;\r | |
163 | }\r | |
164 | \r | |
165 | /**\r | |
166 | Compute how much data to send.\r | |
167 | \r | |
168 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
169 | @param[in] Force If TRUE, to ignore the sender's SWS avoidance algorithm and send\r | |
170 | out data by force.\r | |
171 | \r | |
172 | @return The length of the data can be sent. If 0, no data can be sent.\r | |
173 | \r | |
174 | **/\r | |
175 | UINT32\r | |
176 | TcpDataToSend (\r | |
177 | IN TCP_CB *Tcb,\r | |
178 | IN INTN Force\r | |
179 | )\r | |
180 | {\r | |
181 | SOCKET *Sk;\r | |
182 | UINT32 Win;\r | |
183 | UINT32 Len;\r | |
184 | UINT32 Left;\r | |
185 | UINT32 Limit;\r | |
186 | \r | |
187 | Sk = Tcb->Sk;\r | |
188 | ASSERT (Sk != NULL);\r | |
189 | \r | |
190 | //\r | |
191 | // TCP should NOT send data beyond the send window\r | |
192 | // and congestion window. The right edge of send\r | |
193 | // window is defined as SND.WL2 + SND.WND. The right\r | |
194 | // edge of congestion window is defined as SND.UNA +\r | |
195 | // CWND.\r | |
196 | //\r | |
197 | Win = 0;\r | |
198 | Limit = Tcb->SndWl2 + Tcb->SndWnd;\r | |
199 | \r | |
200 | if (TCP_SEQ_GT (Limit, Tcb->SndUna + Tcb->CWnd)) {\r | |
201 | \r | |
202 | Limit = Tcb->SndUna + Tcb->CWnd;\r | |
203 | }\r | |
204 | \r | |
205 | if (TCP_SEQ_GT (Limit, Tcb->SndNxt)) {\r | |
206 | Win = TCP_SUB_SEQ (Limit, Tcb->SndNxt);\r | |
207 | }\r | |
208 | \r | |
209 | //\r | |
210 | // The data to send contains two parts: the data on the\r | |
211 | // socket send queue, and the data on the TCB's send\r | |
212 | // buffer. The later can be non-zero if the peer shrinks\r | |
213 | // its advertised window.\r | |
214 | //\r | |
215 | Left = GET_SND_DATASIZE (Sk) + TCP_SUB_SEQ (TcpGetMaxSndNxt (Tcb), Tcb->SndNxt);\r | |
216 | \r | |
217 | Len = MIN (Win, Left);\r | |
218 | \r | |
219 | if (Len > Tcb->SndMss) {\r | |
220 | Len = Tcb->SndMss;\r | |
221 | }\r | |
222 | \r | |
223 | if ((Force != 0)|| (Len == 0 && Left == 0)) {\r | |
224 | return Len;\r | |
225 | }\r | |
226 | \r | |
227 | if (Len == 0 && Left != 0) {\r | |
228 | goto SetPersistTimer;\r | |
229 | }\r | |
230 | \r | |
231 | //\r | |
232 | // Sender's SWS avoidance: Don't send a small segment unless\r | |
233 | // a)A full-sized segment can be sent,\r | |
234 | // b)At least one-half of the maximum sized windows that\r | |
235 | // the other end has ever advertised.\r | |
236 | // c)It can send everything it has, and either it isn't\r | |
237 | // expecting an ACK, or the Nagle algorithm is disabled.\r | |
238 | //\r | |
239 | if ((Len == Tcb->SndMss) || (2 * Len >= Tcb->SndWndMax)) {\r | |
240 | \r | |
241 | return Len;\r | |
242 | }\r | |
243 | \r | |
244 | if ((Len == Left) &&\r | |
245 | ((Tcb->SndNxt == Tcb->SndUna) || TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_NO_NAGLE))\r | |
246 | ) {\r | |
247 | \r | |
248 | return Len;\r | |
249 | }\r | |
250 | \r | |
251 | //\r | |
252 | // RFC1122 suggests to set a timer when SWSA forbids TCP\r | |
253 | // sending more data, and combines it with a probe timer.\r | |
254 | //\r | |
255 | SetPersistTimer:\r | |
256 | if (!TCP_TIMER_ON (Tcb->EnabledTimer, TCP_TIMER_REXMIT)) {\r | |
257 | \r | |
258 | DEBUG (\r | |
259 | (EFI_D_WARN,\r | |
260 | "TcpDataToSend: enter persistent state for TCB %p\n",\r | |
261 | Tcb)\r | |
262 | );\r | |
263 | \r | |
264 | if (!Tcb->ProbeTimerOn) {\r | |
265 | TcpSetProbeTimer (Tcb);\r | |
266 | }\r | |
267 | }\r | |
268 | \r | |
269 | return 0;\r | |
270 | }\r | |
271 | \r | |
272 | /**\r | |
273 | Build the TCP header of the TCP segment and transmit the segment by IP.\r | |
274 | \r | |
275 | @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
276 | @param[in] Nbuf Pointer to the buffer containing the segment to be\r | |
277 | sent out.\r | |
278 | \r | |
279 | @retval 0 The segment was sent out successfully.\r | |
280 | @retval -1 An error condition occurred.\r | |
281 | \r | |
282 | **/\r | |
283 | INTN\r | |
284 | TcpTransmitSegment (\r | |
285 | IN OUT TCP_CB *Tcb,\r | |
286 | IN NET_BUF *Nbuf\r | |
287 | )\r | |
288 | {\r | |
289 | UINT16 Len;\r | |
290 | TCP_HEAD *Head;\r | |
291 | TCP_SEG *Seg;\r | |
292 | BOOLEAN Syn;\r | |
293 | UINT32 DataLen;\r | |
294 | \r | |
295 | ASSERT ((Nbuf != NULL) && (Nbuf->Tcp == NULL) && (TcpVerifySegment (Nbuf) != 0));\r | |
296 | \r | |
297 | DataLen = Nbuf->TotalSize;\r | |
298 | \r | |
299 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
300 | Syn = TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN);\r | |
301 | \r | |
302 | if (Syn) {\r | |
303 | \r | |
304 | Len = TcpSynBuildOption (Tcb, Nbuf);\r | |
305 | } else {\r | |
306 | \r | |
307 | Len = TcpBuildOption (Tcb, Nbuf);\r | |
308 | }\r | |
309 | \r | |
310 | ASSERT ((Len % 4 == 0) && (Len <= 40));\r | |
311 | \r | |
312 | Len += sizeof (TCP_HEAD);\r | |
313 | \r | |
314 | Head = (TCP_HEAD *) NetbufAllocSpace (\r | |
315 | Nbuf,\r | |
316 | sizeof (TCP_HEAD),\r | |
317 | NET_BUF_HEAD\r | |
318 | );\r | |
319 | \r | |
320 | ASSERT (Head != NULL);\r | |
321 | \r | |
322 | Nbuf->Tcp = Head;\r | |
323 | \r | |
324 | Head->SrcPort = Tcb->LocalEnd.Port;\r | |
325 | Head->DstPort = Tcb->RemoteEnd.Port;\r | |
326 | Head->Seq = NTOHL (Seg->Seq);\r | |
327 | Head->Ack = NTOHL (Tcb->RcvNxt);\r | |
328 | Head->HeadLen = (UINT8) (Len >> 2);\r | |
329 | Head->Res = 0;\r | |
330 | Head->Wnd = TcpComputeWnd (Tcb, Syn);\r | |
331 | Head->Checksum = 0;\r | |
332 | \r | |
333 | //\r | |
334 | // Check whether to set the PSH flag.\r | |
335 | //\r | |
336 | TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_PSH);\r | |
337 | \r | |
338 | if (DataLen != 0) {\r | |
339 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_PSH) &&\r | |
340 | TCP_SEQ_BETWEEN (Seg->Seq, Tcb->SndPsh, Seg->End)\r | |
341 | ) {\r | |
342 | \r | |
343 | TCP_SET_FLG (Seg->Flag, TCP_FLG_PSH);\r | |
344 | TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_SND_PSH);\r | |
345 | \r | |
346 | } else if ((Seg->End == Tcb->SndNxt) && (GET_SND_DATASIZE (Tcb->Sk) == 0)) {\r | |
347 | \r | |
348 | TCP_SET_FLG (Seg->Flag, TCP_FLG_PSH);\r | |
349 | }\r | |
350 | }\r | |
351 | \r | |
352 | //\r | |
353 | // Check whether to set the URG flag and the urgent pointer.\r | |
354 | //\r | |
355 | TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_URG);\r | |
356 | \r | |
357 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_URG) && TCP_SEQ_LEQ (Seg->Seq, Tcb->SndUp)) {\r | |
358 | \r | |
359 | TCP_SET_FLG (Seg->Flag, TCP_FLG_URG);\r | |
360 | \r | |
361 | if (TCP_SEQ_LT (Tcb->SndUp, Seg->End)) {\r | |
362 | \r | |
363 | Seg->Urg = (UINT16) TCP_SUB_SEQ (Tcb->SndUp, Seg->Seq);\r | |
364 | } else {\r | |
365 | \r | |
366 | Seg->Urg = (UINT16) MIN (\r | |
367 | TCP_SUB_SEQ (Tcb->SndUp,\r | |
368 | Seg->Seq),\r | |
369 | 0xffff\r | |
370 | );\r | |
371 | }\r | |
372 | }\r | |
373 | \r | |
374 | Head->Flag = Seg->Flag;\r | |
375 | Head->Urg = NTOHS (Seg->Urg);\r | |
376 | Head->Checksum = TcpChecksum (Nbuf, Tcb->HeadSum);\r | |
377 | \r | |
378 | //\r | |
379 | // Update the TCP session's control information.\r | |
380 | //\r | |
381 | Tcb->RcvWl2 = Tcb->RcvNxt;\r | |
382 | if (Syn) {\r | |
383 | Tcb->RcvWnd = NTOHS (Head->Wnd);\r | |
384 | }\r | |
385 | \r | |
386 | //\r | |
387 | // Clear the delayedack flag.\r | |
388 | //\r | |
389 | Tcb->DelayedAck = 0;\r | |
390 | \r | |
391 | return TcpSendIpPacket (Tcb, Nbuf, &Tcb->LocalEnd.Ip, &Tcb->RemoteEnd.Ip, Tcb->Sk->IpVersion);\r | |
392 | }\r | |
393 | \r | |
394 | /**\r | |
395 | Get a segment from the Tcb's SndQue.\r | |
396 | \r | |
397 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
398 | @param[in] Seq The sequence number of the segment.\r | |
399 | @param[in] Len The maximum length of the segment.\r | |
400 | \r | |
401 | @return Pointer to the segment. If NULL, some error occurred.\r | |
402 | \r | |
403 | **/\r | |
404 | NET_BUF *\r | |
405 | TcpGetSegmentSndQue (\r | |
406 | IN TCP_CB *Tcb,\r | |
407 | IN TCP_SEQNO Seq,\r | |
408 | IN UINT32 Len\r | |
409 | )\r | |
410 | {\r | |
411 | LIST_ENTRY *Head;\r | |
412 | LIST_ENTRY *Cur;\r | |
413 | NET_BUF *Node;\r | |
414 | TCP_SEG *Seg;\r | |
415 | NET_BUF *Nbuf;\r | |
416 | TCP_SEQNO End;\r | |
417 | UINT8 *Data;\r | |
418 | UINT8 Flag;\r | |
419 | INT32 Offset;\r | |
420 | INT32 CopyLen;\r | |
421 | \r | |
422 | ASSERT ((Tcb != NULL) && TCP_SEQ_LEQ (Seq, Tcb->SndNxt) && (Len > 0));\r | |
423 | \r | |
424 | //\r | |
425 | // Find the segment that contains the Seq.\r | |
426 | //\r | |
427 | Head = &Tcb->SndQue;\r | |
428 | \r | |
429 | Node = NULL;\r | |
430 | Seg = NULL;\r | |
431 | \r | |
432 | NET_LIST_FOR_EACH (Cur, Head) {\r | |
433 | Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);\r | |
434 | Seg = TCPSEG_NETBUF (Node);\r | |
435 | \r | |
436 | if (TCP_SEQ_LT (Seq, Seg->End) && TCP_SEQ_LEQ (Seg->Seq, Seq)) {\r | |
437 | \r | |
438 | break;\r | |
439 | }\r | |
440 | }\r | |
441 | \r | |
442 | if ((Cur == Head) || (Seg == NULL) || (Node == NULL)) {\r | |
443 | return NULL;\r | |
444 | }\r | |
445 | \r | |
446 | //\r | |
447 | // Return the buffer if it can be returned without\r | |
448 | // adjustment:\r | |
449 | //\r | |
450 | if ((Seg->Seq == Seq) &&\r | |
451 | TCP_SEQ_LEQ (Seg->End, Seg->Seq + Len) &&\r | |
452 | !NET_BUF_SHARED (Node)\r | |
453 | ) {\r | |
454 | \r | |
455 | NET_GET_REF (Node);\r | |
456 | return Node;\r | |
457 | }\r | |
458 | \r | |
459 | //\r | |
460 | // Create a new buffer and copy data there.\r | |
461 | //\r | |
462 | Nbuf = NetbufAlloc (Len + TCP_MAX_HEAD);\r | |
463 | \r | |
464 | if (Nbuf == NULL) {\r | |
465 | return NULL;\r | |
466 | }\r | |
467 | \r | |
468 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r | |
469 | \r | |
470 | Flag = Seg->Flag;\r | |
471 | End = Seg->End;\r | |
472 | \r | |
473 | if (TCP_SEQ_LT (Seq + Len, Seg->End)) {\r | |
474 | End = Seq + Len;\r | |
475 | }\r | |
476 | \r | |
477 | CopyLen = TCP_SUB_SEQ (End, Seq);\r | |
478 | Offset = TCP_SUB_SEQ (Seq, Seg->Seq);\r | |
479 | \r | |
480 | //\r | |
481 | // If SYN is set and out of the range, clear the flag.\r | |
482 | // Becuase the sequence of the first byte is SEG.SEQ+1,\r | |
483 | // adjust Offset by -1. If SYN is in the range, copy\r | |
484 | // one byte less.\r | |
485 | //\r | |
486 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {\r | |
487 | \r | |
488 | if (TCP_SEQ_LT (Seg->Seq, Seq)) {\r | |
489 | \r | |
490 | TCP_CLEAR_FLG (Flag, TCP_FLG_SYN);\r | |
491 | Offset--;\r | |
492 | } else {\r | |
493 | \r | |
494 | CopyLen--;\r | |
495 | }\r | |
496 | }\r | |
497 | \r | |
498 | //\r | |
499 | // If FIN is set and in the range, copy one byte less,\r | |
500 | // and if it is out of the range, clear the flag.\r | |
501 | //\r | |
502 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {\r | |
503 | \r | |
504 | if (Seg->End == End) {\r | |
505 | \r | |
506 | CopyLen--;\r | |
507 | } else {\r | |
508 | \r | |
509 | TCP_CLEAR_FLG (Flag, TCP_FLG_FIN);\r | |
510 | }\r | |
511 | }\r | |
512 | \r | |
513 | ASSERT (CopyLen >= 0);\r | |
514 | \r | |
515 | //\r | |
516 | // Copy data to the segment\r | |
517 | //\r | |
518 | if (CopyLen != 0) {\r | |
519 | Data = NetbufAllocSpace (Nbuf, CopyLen, NET_BUF_TAIL);\r | |
520 | ASSERT (Data != NULL);\r | |
521 | \r | |
522 | if ((INT32) NetbufCopy (Node, Offset, CopyLen, Data) != CopyLen) {\r | |
523 | goto OnError;\r | |
524 | }\r | |
525 | }\r | |
526 | \r | |
527 | CopyMem (TCPSEG_NETBUF (Nbuf), Seg, sizeof (TCP_SEG));\r | |
528 | \r | |
529 | TCPSEG_NETBUF (Nbuf)->Seq = Seq;\r | |
530 | TCPSEG_NETBUF (Nbuf)->End = End;\r | |
531 | TCPSEG_NETBUF (Nbuf)->Flag = Flag;\r | |
532 | \r | |
533 | return Nbuf;\r | |
534 | \r | |
535 | OnError:\r | |
536 | NetbufFree (Nbuf);\r | |
537 | return NULL;\r | |
538 | }\r | |
539 | \r | |
540 | /**\r | |
541 | Get a segment from the Tcb's socket buffer.\r | |
542 | \r | |
543 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
544 | @param[in] Seq The sequence number of the segment.\r | |
545 | @param[in] Len The maximum length of the segment.\r | |
546 | \r | |
547 | @return Pointer to the segment. If NULL, some error occurred.\r | |
548 | \r | |
549 | **/\r | |
550 | NET_BUF *\r | |
551 | TcpGetSegmentSock (\r | |
552 | IN TCP_CB *Tcb,\r | |
553 | IN TCP_SEQNO Seq,\r | |
554 | IN UINT32 Len\r | |
555 | )\r | |
556 | {\r | |
557 | NET_BUF *Nbuf;\r | |
558 | UINT8 *Data;\r | |
559 | UINT32 DataGet;\r | |
560 | \r | |
561 | ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));\r | |
562 | \r | |
563 | Nbuf = NetbufAlloc (Len + TCP_MAX_HEAD);\r | |
564 | \r | |
565 | if (Nbuf == NULL) {\r | |
566 | DEBUG (\r | |
567 | (EFI_D_ERROR,\r | |
568 | "TcpGetSegmentSock: failed to allocate a netbuf for TCB %p\n",\r | |
569 | Tcb)\r | |
570 | );\r | |
571 | \r | |
572 | return NULL;\r | |
573 | }\r | |
574 | \r | |
575 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r | |
576 | \r | |
577 | DataGet = 0;\r | |
578 | \r | |
579 | if (Len != 0) {\r | |
580 | //\r | |
581 | // copy data to the segment.\r | |
582 | //\r | |
583 | Data = NetbufAllocSpace (Nbuf, Len, NET_BUF_TAIL);\r | |
584 | ASSERT (Data != NULL);\r | |
585 | \r | |
586 | DataGet = SockGetDataToSend (Tcb->Sk, 0, Len, Data);\r | |
587 | }\r | |
588 | \r | |
589 | NET_GET_REF (Nbuf);\r | |
590 | \r | |
591 | TCPSEG_NETBUF (Nbuf)->Seq = Seq;\r | |
592 | TCPSEG_NETBUF (Nbuf)->End = Seq + Len;\r | |
593 | \r | |
594 | InsertTailList (&(Tcb->SndQue), &(Nbuf->List));\r | |
595 | \r | |
596 | if (DataGet != 0) {\r | |
597 | \r | |
598 | SockDataSent (Tcb->Sk, DataGet);\r | |
599 | }\r | |
600 | \r | |
601 | return Nbuf;\r | |
602 | }\r | |
603 | \r | |
604 | /**\r | |
605 | Get a segment starting from sequence Seq of a maximum\r | |
606 | length of Len.\r | |
607 | \r | |
608 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
609 | @param[in] Seq The sequence number of the segment.\r | |
610 | @param[in] Len The maximum length of the segment.\r | |
611 | \r | |
612 | @return Pointer to the segment. If NULL, some error occurred.\r | |
613 | \r | |
614 | **/\r | |
615 | NET_BUF *\r | |
616 | TcpGetSegment (\r | |
617 | IN TCP_CB *Tcb,\r | |
618 | IN TCP_SEQNO Seq,\r | |
619 | IN UINT32 Len\r | |
620 | )\r | |
621 | {\r | |
622 | NET_BUF *Nbuf;\r | |
623 | \r | |
624 | ASSERT (Tcb != NULL);\r | |
625 | \r | |
626 | //\r | |
627 | // Compare the SndNxt with the max sequence number sent.\r | |
628 | //\r | |
629 | if ((Len != 0) && TCP_SEQ_LT (Seq, TcpGetMaxSndNxt (Tcb))) {\r | |
630 | \r | |
631 | Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r | |
632 | } else {\r | |
633 | \r | |
634 | Nbuf = TcpGetSegmentSock (Tcb, Seq, Len);\r | |
635 | }\r | |
636 | \r | |
637 | ASSERT (TcpVerifySegment (Nbuf) != 0);\r | |
638 | return Nbuf;\r | |
639 | }\r | |
640 | \r | |
641 | /**\r | |
642 | Retransmit the segment from sequence Seq.\r | |
643 | \r | |
644 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
645 | @param[in] Seq The sequence number of the segment to be retransmitted.\r | |
646 | \r | |
647 | @retval 0 Retransmission succeeded.\r | |
648 | @retval -1 Error condition occurred.\r | |
649 | \r | |
650 | **/\r | |
651 | INTN\r | |
652 | TcpRetransmit (\r | |
653 | IN TCP_CB *Tcb,\r | |
654 | IN TCP_SEQNO Seq\r | |
655 | )\r | |
656 | {\r | |
657 | NET_BUF *Nbuf;\r | |
658 | UINT32 Len;\r | |
659 | \r | |
660 | //\r | |
661 | // Compute the maxium length of retransmission. It is\r | |
662 | // limited by three factors:\r | |
663 | // 1. Less than SndMss\r | |
664 | // 2. Must in the current send window\r | |
665 | // 3. Will not change the boundaries of queued segments.\r | |
666 | //\r | |
667 | if (TCP_SEQ_LT (Tcb->SndWl2 + Tcb->SndWnd, Seq)) {\r | |
668 | DEBUG (\r | |
669 | (EFI_D_WARN,\r | |
670 | "TcpRetransmit: retransmission cancelled because send window too small for TCB %p\n",\r | |
671 | Tcb)\r | |
672 | );\r | |
673 | \r | |
674 | return 0;\r | |
675 | }\r | |
676 | \r | |
677 | Len = TCP_SUB_SEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq);\r | |
678 | Len = MIN (Len, Tcb->SndMss);\r | |
679 | \r | |
680 | Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r | |
681 | if (Nbuf == NULL) {\r | |
682 | return -1;\r | |
683 | }\r | |
684 | \r | |
685 | ASSERT (TcpVerifySegment (Nbuf) != 0);\r | |
686 | \r | |
687 | if (TcpTransmitSegment (Tcb, Nbuf) != 0) {\r | |
688 | goto OnError;\r | |
689 | }\r | |
690 | \r | |
691 | //\r | |
692 | // The retransmitted buffer may be on the SndQue,\r | |
693 | // trim TCP head because all the buffers on SndQue\r | |
694 | // are headless.\r | |
695 | //\r | |
696 | ASSERT (Nbuf->Tcp != NULL);\r | |
697 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r | |
698 | Nbuf->Tcp = NULL;\r | |
699 | \r | |
700 | NetbufFree (Nbuf);\r | |
701 | return 0;\r | |
702 | \r | |
703 | OnError:\r | |
704 | if (Nbuf != NULL) {\r | |
705 | NetbufFree (Nbuf);\r | |
706 | }\r | |
707 | \r | |
708 | return -1;\r | |
709 | }\r | |
710 | \r | |
711 | /**\r | |
712 | Verify that all the segments in SndQue are in good shape.\r | |
713 | \r | |
714 | @param[in] Head Pointer to the head node of the SndQue.\r | |
715 | \r | |
716 | @retval 0 At least one segment is broken.\r | |
717 | @retval 1 All segments in the specific queue are in good shape.\r | |
718 | \r | |
719 | **/\r | |
720 | INTN\r | |
721 | TcpCheckSndQue (\r | |
722 | IN LIST_ENTRY *Head\r | |
723 | )\r | |
724 | {\r | |
725 | LIST_ENTRY *Entry;\r | |
726 | NET_BUF *Nbuf;\r | |
727 | TCP_SEQNO Seq;\r | |
728 | \r | |
729 | if (IsListEmpty (Head)) {\r | |
730 | return 1;\r | |
731 | }\r | |
732 | //\r | |
733 | // Initialize the Seq.\r | |
734 | //\r | |
735 | Entry = Head->ForwardLink;\r | |
736 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r | |
737 | Seq = TCPSEG_NETBUF (Nbuf)->Seq;\r | |
738 | \r | |
739 | NET_LIST_FOR_EACH (Entry, Head) {\r | |
740 | Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r | |
741 | \r | |
742 | if (TcpVerifySegment (Nbuf) == 0) {\r | |
743 | return 0;\r | |
744 | }\r | |
745 | \r | |
746 | //\r | |
747 | // All the node in the SndQue should has:\r | |
748 | // SEG.SEQ = LAST_SEG.END\r | |
749 | //\r | |
750 | if (Seq != TCPSEG_NETBUF (Nbuf)->Seq) {\r | |
751 | return 0;\r | |
752 | }\r | |
753 | \r | |
754 | Seq = TCPSEG_NETBUF (Nbuf)->End;\r | |
755 | }\r | |
756 | \r | |
757 | return 1;\r | |
758 | }\r | |
759 | \r | |
760 | /**\r | |
761 | Check whether to send data/SYN/FIN and piggyback an ACK.\r | |
762 | \r | |
763 | @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
764 | @param[in] Force If TRUE, ignore the sender's SWS avoidance algorithm\r | |
765 | and send out data by force.\r | |
766 | \r | |
767 | @return The number of bytes sent.\r | |
768 | \r | |
769 | **/\r | |
770 | INTN\r | |
771 | TcpToSendData (\r | |
772 | IN OUT TCP_CB *Tcb,\r | |
773 | IN INTN Force\r | |
774 | )\r | |
775 | {\r | |
776 | UINT32 Len;\r | |
777 | INTN Sent;\r | |
778 | UINT8 Flag;\r | |
779 | NET_BUF *Nbuf;\r | |
780 | TCP_SEG *Seg;\r | |
781 | TCP_SEQNO Seq;\r | |
782 | TCP_SEQNO End;\r | |
783 | \r | |
784 | ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL) && (Tcb->State != TCP_LISTEN));\r | |
785 | \r | |
786 | Sent = 0;\r | |
787 | \r | |
788 | if ((Tcb->State == TCP_CLOSED) || TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT)) {\r | |
789 | \r | |
790 | return 0;\r | |
791 | }\r | |
792 | \r | |
793 | do {\r | |
794 | //\r | |
795 | // Compute how much data can be sent\r | |
796 | //\r | |
797 | Len = TcpDataToSend (Tcb, Force);\r | |
798 | Seq = Tcb->SndNxt;\r | |
799 | \r | |
800 | ASSERT ((Tcb->State) < (ARRAY_SIZE (mTcpOutFlag)));\r | |
801 | Flag = mTcpOutFlag[Tcb->State];\r | |
802 | \r | |
803 | if ((Flag & TCP_FLG_SYN) != 0) {\r | |
804 | \r | |
805 | Seq = Tcb->Iss;\r | |
806 | Len = 0;\r | |
807 | }\r | |
808 | \r | |
809 | //\r | |
810 | // Only send a segment without data if SYN or\r | |
811 | // FIN is set.\r | |
812 | //\r | |
813 | if ((Len == 0) && ((Flag & (TCP_FLG_SYN | TCP_FLG_FIN)) == 0)) {\r | |
814 | return Sent;\r | |
815 | }\r | |
816 | \r | |
817 | Nbuf = TcpGetSegment (Tcb, Seq, Len);\r | |
818 | \r | |
819 | if (Nbuf == NULL) {\r | |
820 | DEBUG (\r | |
821 | (EFI_D_ERROR,\r | |
822 | "TcpToSendData: failed to get a segment for TCB %p\n",\r | |
823 | Tcb)\r | |
824 | );\r | |
825 | \r | |
826 | goto OnError;\r | |
827 | }\r | |
828 | \r | |
829 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
830 | \r | |
831 | //\r | |
832 | // Set the TcpSeg in Nbuf.\r | |
833 | //\r | |
834 | Len = Nbuf->TotalSize;\r | |
835 | End = Seq + Len;\r | |
836 | if (TCP_FLG_ON (Flag, TCP_FLG_SYN)) {\r | |
837 | End++;\r | |
838 | }\r | |
839 | \r | |
840 | if ((Flag & TCP_FLG_FIN) != 0) {\r | |
841 | //\r | |
842 | // Send FIN if all data is sent, and FIN is\r | |
843 | // in the window\r | |
844 | //\r | |
845 | if ((TcpGetMaxSndNxt (Tcb) == Tcb->SndNxt) &&\r | |
846 | (GET_SND_DATASIZE (Tcb->Sk) == 0) &&\r | |
847 | TCP_SEQ_LT (End + 1, Tcb->SndWnd + Tcb->SndWl2)\r | |
848 | ) {\r | |
849 | DEBUG (\r | |
850 | (EFI_D_NET,\r | |
851 | "TcpToSendData: send FIN to peer for TCB %p in state %s\n",\r | |
852 | Tcb,\r | |
853 | mTcpStateName[Tcb->State])\r | |
854 | );\r | |
855 | \r | |
856 | End++;\r | |
857 | } else {\r | |
858 | TCP_CLEAR_FLG (Flag, TCP_FLG_FIN);\r | |
859 | }\r | |
860 | }\r | |
861 | \r | |
862 | Seg->Seq = Seq;\r | |
863 | Seg->End = End;\r | |
864 | Seg->Flag = Flag;\r | |
865 | \r | |
866 | ASSERT (TcpVerifySegment (Nbuf) != 0);\r | |
867 | ASSERT (TcpCheckSndQue (&Tcb->SndQue) != 0);\r | |
868 | \r | |
869 | //\r | |
870 | // Don't send an empty segment here.\r | |
871 | //\r | |
872 | if (Seg->End == Seg->Seq) {\r | |
873 | DEBUG (\r | |
874 | (EFI_D_WARN,\r | |
875 | "TcpToSendData: created a empty segment for TCB %p, free it now\n",\r | |
876 | Tcb)\r | |
877 | );\r | |
878 | \r | |
879 | NetbufFree (Nbuf);\r | |
880 | return Sent;\r | |
881 | }\r | |
882 | \r | |
883 | if (TcpTransmitSegment (Tcb, Nbuf) != 0) {\r | |
884 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r | |
885 | Nbuf->Tcp = NULL;\r | |
886 | \r | |
887 | if ((Flag & TCP_FLG_FIN) != 0) {\r | |
888 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT);\r | |
889 | }\r | |
890 | \r | |
891 | goto OnError;\r | |
892 | }\r | |
893 | \r | |
894 | Sent += TCP_SUB_SEQ (End, Seq);\r | |
895 | \r | |
896 | //\r | |
897 | // All the buffers in the SndQue are headless.\r | |
898 | //\r | |
899 | ASSERT (Nbuf->Tcp != NULL);\r | |
900 | \r | |
901 | NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r | |
902 | Nbuf->Tcp = NULL;\r | |
903 | \r | |
904 | NetbufFree (Nbuf);\r | |
905 | \r | |
906 | //\r | |
907 | // Update the status in TCB.\r | |
908 | //\r | |
909 | Tcb->DelayedAck = 0;\r | |
910 | \r | |
911 | if ((Flag & TCP_FLG_FIN) != 0) {\r | |
912 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT);\r | |
913 | }\r | |
914 | \r | |
915 | if (TCP_SEQ_GT (End, Tcb->SndNxt)) {\r | |
916 | Tcb->SndNxt = End;\r | |
917 | }\r | |
918 | \r | |
919 | if (!TCP_TIMER_ON (Tcb->EnabledTimer, TCP_TIMER_REXMIT)) {\r | |
920 | TcpSetTimer (Tcb, TCP_TIMER_REXMIT, Tcb->Rto);\r | |
921 | }\r | |
922 | \r | |
923 | //\r | |
924 | // Enable RTT measurement only if not in retransmit.\r | |
925 | // Karn's algorithm requires not to update RTT when in loss.\r | |
926 | //\r | |
927 | if ((Tcb->CongestState == TCP_CONGEST_OPEN) && !TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {\r | |
928 | \r | |
929 | DEBUG (\r | |
930 | (EFI_D_NET,\r | |
931 | "TcpToSendData: set RTT measure sequence %d for TCB %p\n",\r | |
932 | Seq,\r | |
933 | Tcb)\r | |
934 | );\r | |
935 | \r | |
936 | TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);\r | |
937 | Tcb->RttSeq = Seq;\r | |
938 | Tcb->RttMeasure = 0;\r | |
939 | }\r | |
940 | \r | |
941 | } while (Len == Tcb->SndMss);\r | |
942 | \r | |
943 | return Sent;\r | |
944 | \r | |
945 | OnError:\r | |
946 | if (Nbuf != NULL) {\r | |
947 | NetbufFree (Nbuf);\r | |
948 | }\r | |
949 | \r | |
950 | return Sent;\r | |
951 | }\r | |
952 | \r | |
953 | /**\r | |
954 | Send an ACK immediately.\r | |
955 | \r | |
956 | @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
957 | \r | |
958 | **/\r | |
959 | VOID\r | |
960 | TcpSendAck (\r | |
961 | IN OUT TCP_CB *Tcb\r | |
962 | )\r | |
963 | {\r | |
964 | NET_BUF *Nbuf;\r | |
965 | TCP_SEG *Seg;\r | |
966 | \r | |
967 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r | |
968 | \r | |
969 | if (Nbuf == NULL) {\r | |
970 | return;\r | |
971 | }\r | |
972 | \r | |
973 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r | |
974 | \r | |
975 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
976 | Seg->Seq = Tcb->SndNxt;\r | |
977 | Seg->End = Tcb->SndNxt;\r | |
978 | Seg->Flag = TCP_FLG_ACK;\r | |
979 | \r | |
980 | if (TcpTransmitSegment (Tcb, Nbuf) == 0) {\r | |
981 | TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);\r | |
982 | Tcb->DelayedAck = 0;\r | |
983 | }\r | |
984 | \r | |
985 | NetbufFree (Nbuf);\r | |
986 | }\r | |
987 | \r | |
988 | /**\r | |
989 | Send a zero probe segment. It can be used by keepalive and zero window probe.\r | |
990 | \r | |
991 | @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
992 | \r | |
993 | @retval 0 The zero probe segment was sent out successfully.\r | |
994 | @retval other An error condition occurred.\r | |
995 | \r | |
996 | **/\r | |
997 | INTN\r | |
998 | TcpSendZeroProbe (\r | |
999 | IN OUT TCP_CB *Tcb\r | |
1000 | )\r | |
1001 | {\r | |
1002 | NET_BUF *Nbuf;\r | |
1003 | TCP_SEG *Seg;\r | |
1004 | INTN Result;\r | |
1005 | \r | |
1006 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r | |
1007 | \r | |
1008 | if (Nbuf == NULL) {\r | |
1009 | return -1;\r | |
1010 | }\r | |
1011 | \r | |
1012 | NetbufReserve (Nbuf, TCP_MAX_HEAD);\r | |
1013 | \r | |
1014 | //\r | |
1015 | // SndNxt-1 is out of window. The peer should respond\r | |
1016 | // with an ACK.\r | |
1017 | //\r | |
1018 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
1019 | Seg->Seq = Tcb->SndNxt - 1;\r | |
1020 | Seg->End = Tcb->SndNxt - 1;\r | |
1021 | Seg->Flag = TCP_FLG_ACK;\r | |
1022 | \r | |
1023 | Result = TcpTransmitSegment (Tcb, Nbuf);\r | |
1024 | NetbufFree (Nbuf);\r | |
1025 | \r | |
1026 | return Result;\r | |
1027 | }\r | |
1028 | \r | |
1029 | /**\r | |
1030 | Check whether to send an ACK or delayed ACK.\r | |
1031 | \r | |
1032 | @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.\r | |
1033 | \r | |
1034 | **/\r | |
1035 | VOID\r | |
1036 | TcpToSendAck (\r | |
1037 | IN OUT TCP_CB *Tcb\r | |
1038 | )\r | |
1039 | {\r | |
1040 | UINT32 TcpNow;\r | |
1041 | \r | |
1042 | //\r | |
1043 | // Generally, TCP should send a delayed ACK unless:\r | |
1044 | // 1. ACK at least every other FULL sized segment received.\r | |
1045 | // 2. Packets received out of order.\r | |
1046 | // 3. Receiving window is open.\r | |
1047 | //\r | |
1048 | if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW) || (Tcb->DelayedAck >= 1)) {\r | |
1049 | TcpSendAck (Tcb);\r | |
1050 | return;\r | |
1051 | }\r | |
1052 | \r | |
1053 | TcpNow = TcpRcvWinNow (Tcb);\r | |
1054 | \r | |
1055 | if (TcpNow > TcpRcvWinOld (Tcb)) {\r | |
1056 | TcpSendAck (Tcb);\r | |
1057 | return;\r | |
1058 | }\r | |
1059 | \r | |
1060 | DEBUG (\r | |
1061 | (EFI_D_NET,\r | |
1062 | "TcpToSendAck: scheduled a delayed ACK for TCB %p\n",\r | |
1063 | Tcb)\r | |
1064 | );\r | |
1065 | \r | |
1066 | //\r | |
1067 | // Schedule a delayed ACK.\r | |
1068 | //\r | |
1069 | Tcb->DelayedAck++;\r | |
1070 | }\r | |
1071 | \r | |
1072 | /**\r | |
1073 | Send a RESET segment in response to the segment received.\r | |
1074 | \r | |
1075 | @param[in] Tcb Pointer to the TCP_CB of this TCP instance. May be NULL.\r | |
1076 | @param[in] Head TCP header of the segment that triggers the reset.\r | |
1077 | @param[in] Len Length of the segment that triggers the reset.\r | |
1078 | @param[in] Local Local IP address.\r | |
1079 | @param[in] Remote Remote peer's IP address.\r | |
1080 | @param[in] Version IP_VERSION_4 indicates TCP is running on IP4 stack,\r | |
1081 | IP_VERSION_6 indicates TCP is running on IP6 stack.\r | |
1082 | \r | |
1083 | @retval 0 A reset was sent or there is no need to send it.\r | |
1084 | @retval -1 No reset is sent.\r | |
1085 | \r | |
1086 | **/\r | |
1087 | INTN\r | |
1088 | TcpSendReset (\r | |
1089 | IN TCP_CB *Tcb,\r | |
1090 | IN TCP_HEAD *Head,\r | |
1091 | IN INT32 Len,\r | |
1092 | IN EFI_IP_ADDRESS *Local,\r | |
1093 | IN EFI_IP_ADDRESS *Remote,\r | |
1094 | IN UINT8 Version\r | |
1095 | )\r | |
1096 | {\r | |
1097 | NET_BUF *Nbuf;\r | |
1098 | TCP_HEAD *Nhead;\r | |
1099 | UINT16 HeadSum;\r | |
1100 | \r | |
1101 | //\r | |
1102 | // Don't respond to a Reset with reset.\r | |
1103 | //\r | |
1104 | if ((Head->Flag & TCP_FLG_RST) != 0) {\r | |
1105 | return 0;\r | |
1106 | }\r | |
1107 | \r | |
1108 | Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r | |
1109 | \r | |
1110 | if (Nbuf == NULL) {\r | |
1111 | return -1;\r | |
1112 | }\r | |
1113 | \r | |
1114 | Nhead = (TCP_HEAD *) NetbufAllocSpace (\r | |
1115 | Nbuf,\r | |
1116 | sizeof (TCP_HEAD),\r | |
1117 | NET_BUF_TAIL\r | |
1118 | );\r | |
1119 | \r | |
1120 | ASSERT (Nhead != NULL);\r | |
1121 | \r | |
1122 | Nbuf->Tcp = Nhead;\r | |
1123 | Nhead->Flag = TCP_FLG_RST;\r | |
1124 | \r | |
1125 | //\r | |
1126 | // Derive Seq/ACK from the segment if no TCB\r | |
1127 | // is associated with it, otherwise derive from the Tcb.\r | |
1128 | //\r | |
1129 | if (Tcb == NULL) {\r | |
1130 | \r | |
1131 | if (TCP_FLG_ON (Head->Flag, TCP_FLG_ACK)) {\r | |
1132 | Nhead->Seq = Head->Ack;\r | |
1133 | Nhead->Ack = 0;\r | |
1134 | } else {\r | |
1135 | Nhead->Seq = 0;\r | |
1136 | TCP_SET_FLG (Nhead->Flag, TCP_FLG_ACK);\r | |
1137 | Nhead->Ack = HTONL (NTOHL (Head->Seq) + Len);\r | |
1138 | }\r | |
1139 | } else {\r | |
1140 | \r | |
1141 | Nhead->Seq = HTONL (Tcb->SndNxt);\r | |
1142 | Nhead->Ack = HTONL (Tcb->RcvNxt);\r | |
1143 | TCP_SET_FLG (Nhead->Flag, TCP_FLG_ACK);\r | |
1144 | }\r | |
1145 | \r | |
1146 | Nhead->SrcPort = Head->DstPort;\r | |
1147 | Nhead->DstPort = Head->SrcPort;\r | |
1148 | Nhead->HeadLen = (UINT8) (sizeof (TCP_HEAD) >> 2);\r | |
1149 | Nhead->Res = 0;\r | |
1150 | Nhead->Wnd = HTONS (0xFFFF);\r | |
1151 | Nhead->Checksum = 0;\r | |
1152 | Nhead->Urg = 0;\r | |
1153 | \r | |
1154 | if (Version == IP_VERSION_4) {\r | |
1155 | HeadSum = NetPseudoHeadChecksum (Local->Addr[0], Remote->Addr[0], 6, 0);\r | |
1156 | } else {\r | |
1157 | HeadSum = NetIp6PseudoHeadChecksum (&Local->v6, &Remote->v6, 6, 0);\r | |
1158 | }\r | |
1159 | \r | |
1160 | Nhead->Checksum = TcpChecksum (Nbuf, HeadSum);\r | |
1161 | \r | |
1162 | TcpSendIpPacket (Tcb, Nbuf, Local, Remote, Version);\r | |
1163 | \r | |
1164 | NetbufFree (Nbuf);\r | |
1165 | \r | |
1166 | return 0;\r | |
1167 | }\r | |
1168 | \r | |
1169 | /**\r | |
1170 | Verify that the segment is in good shape.\r | |
1171 | \r | |
1172 | @param[in] Nbuf The buffer that contains the segment to be checked.\r | |
1173 | \r | |
1174 | @retval 0 The segment is broken.\r | |
1175 | @retval 1 The segment is in good shape.\r | |
1176 | \r | |
1177 | **/\r | |
1178 | INTN\r | |
1179 | TcpVerifySegment (\r | |
1180 | IN NET_BUF *Nbuf\r | |
1181 | )\r | |
1182 | {\r | |
1183 | TCP_HEAD *Head;\r | |
1184 | TCP_SEG *Seg;\r | |
1185 | UINT32 Len;\r | |
1186 | \r | |
1187 | if (Nbuf == NULL) {\r | |
1188 | return 1;\r | |
1189 | }\r | |
1190 | \r | |
1191 | NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE);\r | |
1192 | \r | |
1193 | Seg = TCPSEG_NETBUF (Nbuf);\r | |
1194 | Len = Nbuf->TotalSize;\r | |
1195 | Head = Nbuf->Tcp;\r | |
1196 | \r | |
1197 | if (Head != NULL) {\r | |
1198 | if (Head->Flag != Seg->Flag) {\r | |
1199 | return 0;\r | |
1200 | }\r | |
1201 | \r | |
1202 | Len -= (Head->HeadLen << 2);\r | |
1203 | }\r | |
1204 | \r | |
1205 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {\r | |
1206 | Len++;\r | |
1207 | }\r | |
1208 | \r | |
1209 | if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {\r | |
1210 | Len++;\r | |
1211 | }\r | |
1212 | \r | |
1213 | if (Seg->Seq + Len != Seg->End) {\r | |
1214 | return 0;\r | |
1215 | }\r | |
1216 | \r | |
1217 | return 1;\r | |
1218 | }\r | |
1219 | \r |