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8a67d61d 1/** @file\r
2\r
3Copyright (c) 2005 - 2006, Intel Corporation\r
4All rights reserved. This program and the accompanying materials\r
5are licensed and made available under the terms and conditions of the BSD License\r
6which accompanies this distribution. The full text of the license may be found at\r
7http://opensource.org/licenses/bsd-license.php\r
8\r
9THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
10WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
11\r
12Module Name:\r
13\r
14 Tcp4Output.c\r
15\r
16Abstract:\r
17\r
18 TCP output process routines.\r
19\r
20\r
21**/\r
22\r
23#include "Tcp4Main.h"\r
24\r
25STATIC 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
48UINT32\r
49TcpRcvWinOld (\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
77UINT32\r
78TcpRcvWinNow (\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
125STATIC\r
126UINT16\r
127TcpComputeWnd (\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
36ee91ca 147 Wnd = MIN (Wnd >> Tcb->RcvWndScale, 0xffff);\r
8a67d61d 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
160TCP_SEQNO\r
161TcpGetMaxSndNxt (\r
162 IN TCP_CB *Tcb\r
163 )\r
164{\r
e48e37fc 165 LIST_ENTRY *Entry;\r
8a67d61d 166 NET_BUF *Nbuf;\r
167\r
e48e37fc 168 if (IsListEmpty (&Tcb->SndQue)) {\r
8a67d61d 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
190UINT32\r
191TcpDataToSend (\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
36ee91ca 233 Len = MIN (Win, Left);\r
8a67d61d 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
271SetPersistTimer:\r
272 if (!TCP_TIMER_ON (Tcb->EnabledTimer, TCP_TIMER_REXMIT)) {\r
273\r
e48e37fc 274 DEBUG (\r
275 (EFI_D_WARN,\r
0e549d5b 276 "TcpDataToSend: enter persistent state for TCB %p\n",\r
8a67d61d 277 Tcb)\r
278 );\r
279\r
280 TcpSetProbeTimer (Tcb);\r
281 }\r
282\r
283 return 0;\r
284}\r
285\r
286\r
287/**\r
288 Build the TCP header of the TCP segment and transmit the\r
289 segment by IP.\r
290\r
291 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
292 @param Nbuf Pointer to the buffer containing the segment to be sent out.\r
293\r
294 @retval 0 The segment is sent out successfully.\r
295 @retval other Error condition occurred.\r
296\r
297**/\r
298STATIC\r
299INTN\r
300TcpTransmitSegment (\r
301 IN TCP_CB *Tcb,\r
302 IN NET_BUF *Nbuf\r
303 )\r
304{\r
305 UINT16 Len;\r
306 TCP_HEAD *Head;\r
307 TCP_SEG *Seg;\r
308 BOOLEAN Syn;\r
309 UINT32 DataLen;\r
310\r
311 ASSERT (Nbuf && (Nbuf->Tcp == NULL) && TcpVerifySegment (Nbuf));\r
312\r
313 DataLen = Nbuf->TotalSize;\r
314\r
315 Seg = TCPSEG_NETBUF (Nbuf);\r
316 Syn = TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN);\r
317\r
318 if (Syn) {\r
319\r
320 Len = TcpSynBuildOption (Tcb, Nbuf);\r
321 } else {\r
322\r
323 Len = TcpBuildOption (Tcb, Nbuf);\r
324 }\r
325\r
326 ASSERT ((Len % 4 == 0) && (Len <= 40));\r
327\r
328 Len += sizeof (TCP_HEAD);\r
329\r
330 Head = (TCP_HEAD *) NetbufAllocSpace (\r
331 Nbuf,\r
332 sizeof (TCP_HEAD),\r
333 NET_BUF_HEAD\r
334 );\r
335\r
336 ASSERT (Head != NULL);\r
337\r
338 Nbuf->Tcp = Head;\r
339\r
340 Head->SrcPort = Tcb->LocalEnd.Port;\r
341 Head->DstPort = Tcb->RemoteEnd.Port;\r
342 Head->Seq = NTOHL (Seg->Seq);\r
343 Head->Ack = NTOHL (Tcb->RcvNxt);\r
344 Head->HeadLen = (UINT8) (Len >> 2);\r
345 Head->Res = 0;\r
346 Head->Wnd = TcpComputeWnd (Tcb, Syn);\r
347 Head->Checksum = 0;\r
348\r
349 //\r
350 // Check whether to set the PSH flag.\r
351 //\r
352 TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_PSH);\r
353\r
354 if (DataLen != 0) {\r
355 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_PSH) &&\r
356 TCP_SEQ_BETWEEN (Seg->Seq, Tcb->SndPsh, Seg->End)) {\r
357\r
358 TCP_SET_FLG (Seg->Flag, TCP_FLG_PSH);\r
359 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_SND_PSH);\r
360\r
361 } else if ((Seg->End == Tcb->SndNxt) &&\r
362 (GET_SND_DATASIZE (Tcb->Sk) == 0)) {\r
363\r
364 TCP_SET_FLG (Seg->Flag, TCP_FLG_PSH);\r
365 }\r
366 }\r
367\r
368 //\r
369 // Check whether to set the URG flag and the urgent pointer.\r
370 //\r
371 TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_URG);\r
372\r
373 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_URG) &&\r
374 TCP_SEQ_LEQ (Seg->Seq, Tcb->SndUp)) {\r
375\r
376 TCP_SET_FLG (Seg->Flag, TCP_FLG_URG);\r
377\r
378 if (TCP_SEQ_LT (Tcb->SndUp, Seg->End)) {\r
379\r
380 Seg->Urg = (UINT16) TCP_SUB_SEQ (Tcb->SndUp, Seg->Seq);\r
381 } else {\r
382\r
36ee91ca 383 Seg->Urg = (UINT16) MIN (\r
8a67d61d 384 TCP_SUB_SEQ (Tcb->SndUp,\r
385 Seg->Seq),\r
386 0xffff\r
387 );\r
388 }\r
389 }\r
390\r
391 Head->Flag = Seg->Flag;\r
392 Head->Urg = NTOHS (Seg->Urg);\r
393 Head->Checksum = TcpChecksum (Nbuf, Tcb->HeadSum);\r
394\r
395 //\r
396 // update the TCP session's control information\r
397 //\r
398 Tcb->RcvWl2 = Tcb->RcvNxt;\r
399 if (Syn) {\r
400 Tcb->RcvWnd = NTOHS (Head->Wnd);\r
401 }\r
402\r
403 //\r
404 // clear delayedack flag\r
405 //\r
406 Tcb->DelayedAck = 0;\r
407\r
408 return TcpSendIpPacket (Tcb, Nbuf, Tcb->LocalEnd.Ip, Tcb->RemoteEnd.Ip);\r
409}\r
410\r
411\r
412/**\r
413 Get a segment from the Tcb's SndQue.\r
414\r
415 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
416 @param Seq The sequence number of the segment.\r
417 @param Len The maximum length of the segment.\r
418\r
419 @return Pointer to the segment, if NULL some error occurred.\r
420\r
421**/\r
422NET_BUF *\r
423TcpGetSegmentSndQue (\r
424 IN TCP_CB *Tcb,\r
425 IN TCP_SEQNO Seq,\r
426 IN UINT32 Len\r
427 )\r
428{\r
e48e37fc 429 LIST_ENTRY *Head;\r
430 LIST_ENTRY *Cur;\r
8a67d61d 431 NET_BUF *Node;\r
432 TCP_SEG *Seg;\r
433 NET_BUF *Nbuf;\r
434 TCP_SEQNO End;\r
435 UINT8 *Data;\r
436 UINT8 Flag;\r
437 INT32 Offset;\r
438 INT32 CopyLen;\r
439\r
440 ASSERT (Tcb && TCP_SEQ_LEQ (Seq, Tcb->SndNxt) && (Len > 0));\r
441\r
442 //\r
443 // Find the segment that contains the Seq.\r
444 //\r
445 Head = &Tcb->SndQue;\r
446\r
447 Node = NULL;\r
448 Seg = NULL;\r
449\r
450 NET_LIST_FOR_EACH (Cur, Head) {\r
451 Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);\r
452 Seg = TCPSEG_NETBUF (Node);\r
453\r
454 if (TCP_SEQ_LT (Seq, Seg->End) && TCP_SEQ_LEQ (Seg->Seq, Seq)) {\r
455\r
456 break;\r
457 }\r
458 }\r
459\r
460 ASSERT (Cur != Head);\r
461\r
462 //\r
463 // Return the buffer if it can be returned without\r
464 // adjustment:\r
465 //\r
466 if ((Seg->Seq == Seq) &&\r
467 TCP_SEQ_LEQ (Seg->End, Seg->Seq + Len) &&\r
468 !NET_BUF_SHARED (Node)) {\r
469\r
470 NET_GET_REF (Node);\r
471 return Node;\r
472 }\r
473\r
474 //\r
475 // Create a new buffer and copy data there.\r
476 //\r
477 Nbuf = NetbufAlloc (Len + TCP_MAX_HEAD);\r
478\r
479 if (Nbuf == NULL) {\r
480 return NULL;\r
481 }\r
482\r
483 NetbufReserve (Nbuf, TCP_MAX_HEAD);\r
484\r
485 Flag = Seg->Flag;\r
486 End = Seg->End;\r
487\r
488 if (TCP_SEQ_LT (Seq + Len, Seg->End)) {\r
489 End = Seq + Len;\r
490 }\r
491\r
492 CopyLen = TCP_SUB_SEQ (End, Seq);\r
493 Offset = TCP_SUB_SEQ (Seq, Seg->Seq);\r
494\r
495 //\r
496 // If SYN is set and out of the range, clear the flag.\r
497 // Becuase the sequence of the first byte is SEG.SEQ+1,\r
498 // adjust Offset by -1. If SYN is in the range, copy\r
499 // one byte less.\r
500 //\r
501 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {\r
502\r
503 if (TCP_SEQ_LT (Seg->Seq, Seq)) {\r
504\r
505 TCP_CLEAR_FLG (Flag, TCP_FLG_SYN);\r
506 Offset--;\r
507 } else {\r
508\r
509 CopyLen--;\r
510 }\r
511 }\r
512\r
513 //\r
514 // If FIN is set and in the range, copy one byte less,\r
515 // and if it is out of the range, clear the flag.\r
516 //\r
517 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {\r
518\r
519 if (Seg->End == End) {\r
520\r
521 CopyLen--;\r
522 } else {\r
523\r
524 TCP_CLEAR_FLG (Flag, TCP_FLG_FIN);\r
525 }\r
526 }\r
527\r
528 ASSERT (CopyLen >= 0);\r
529\r
530 //\r
531 // copy data to the segment\r
532 //\r
533 if (CopyLen) {\r
534 Data = NetbufAllocSpace (Nbuf, CopyLen, NET_BUF_TAIL);\r
535 ASSERT (Data);\r
536\r
537 if ((INT32) NetbufCopy (Node, Offset, CopyLen, Data) != CopyLen) {\r
538 goto OnError;\r
539 }\r
540 }\r
541\r
e48e37fc 542 CopyMem (TCPSEG_NETBUF (Nbuf), Seg, sizeof (TCP_SEG));\r
8a67d61d 543\r
544 TCPSEG_NETBUF (Nbuf)->Seq = Seq;\r
545 TCPSEG_NETBUF (Nbuf)->End = End;\r
546 TCPSEG_NETBUF (Nbuf)->Flag = Flag;\r
547\r
548 return Nbuf;\r
549\r
550OnError:\r
551 NetbufFree (Nbuf);\r
552 return NULL;\r
553}\r
554\r
555\r
556/**\r
557 Get a segment from the Tcb's socket buffer.\r
558\r
559 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
560 @param Seq The sequence number of the segment.\r
561 @param Len The maximum length of the segment.\r
562\r
563 @return Pointer to the segment, if NULL some error occurred.\r
564\r
565**/\r
566NET_BUF *\r
567TcpGetSegmentSock (\r
568 IN TCP_CB *Tcb,\r
569 IN TCP_SEQNO Seq,\r
570 IN UINT32 Len\r
571 )\r
572{\r
573 NET_BUF *Nbuf;\r
574 UINT8 *Data;\r
575 UINT32 DataGet;\r
576\r
577 ASSERT (Tcb && Tcb->Sk);\r
578\r
579 Nbuf = NetbufAlloc (Len + TCP_MAX_HEAD);\r
580\r
581 if (Nbuf == NULL) {\r
e48e37fc 582 DEBUG ((EFI_D_ERROR, "TcpGetSegmentSock: failed to allocate "\r
0e549d5b 583 "a netbuf for TCB %p\n",Tcb));\r
8a67d61d 584\r
585 return NULL;\r
586 }\r
587\r
588 NetbufReserve (Nbuf, TCP_MAX_HEAD);\r
589\r
590 DataGet = 0;\r
591\r
592 if (Len) {\r
593 //\r
594 // copy data to the segment.\r
595 //\r
596 Data = NetbufAllocSpace (Nbuf, Len, NET_BUF_TAIL);\r
597 ASSERT (Data);\r
598\r
599 DataGet = SockGetDataToSend (Tcb->Sk, 0, Len, Data);\r
600 }\r
601\r
602 NET_GET_REF (Nbuf);\r
603\r
604 TCPSEG_NETBUF (Nbuf)->Seq = Seq;\r
605 TCPSEG_NETBUF (Nbuf)->End = Seq + Len;\r
606\r
e48e37fc 607 InsertTailList (&(Tcb->SndQue), &(Nbuf->List));\r
8a67d61d 608\r
609 if (DataGet != 0) {\r
610\r
611 SockDataSent (Tcb->Sk, DataGet);\r
612 }\r
613\r
614 return Nbuf;\r
615}\r
616\r
617\r
618/**\r
619 Get a segment starting from sequence Seq of a maximum\r
620 length of Len.\r
621\r
622 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
623 @param Seq The sequence number of the segment.\r
624 @param Len The maximum length of the segment.\r
625\r
626 @return Pointer to the segment, if NULL some error occurred.\r
627\r
628**/\r
629NET_BUF *\r
630TcpGetSegment (\r
631 IN TCP_CB *Tcb,\r
632 IN TCP_SEQNO Seq,\r
633 IN UINT32 Len\r
634 )\r
635{\r
636 NET_BUF *Nbuf;\r
637\r
638 ASSERT (Tcb);\r
639\r
640 //\r
641 // Compare the SndNxt with the max sequence number sent.\r
642 //\r
643 if ((Len != 0) && TCP_SEQ_LT (Seq, TcpGetMaxSndNxt (Tcb))) {\r
644\r
645 Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r
646 } else {\r
647\r
648 Nbuf = TcpGetSegmentSock (Tcb, Seq, Len);\r
649 }\r
650\r
651 ASSERT (TcpVerifySegment (Nbuf));\r
652 return Nbuf;\r
653}\r
654\r
655\r
656/**\r
657 Retransmit the segment from sequence Seq.\r
658\r
659 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
660 @param Seq The sequence number of the segment to be retransmitted.\r
661\r
662 @retval 0 Retransmission succeeded.\r
663 @retval -1 Error condition occurred.\r
664\r
665**/\r
666INTN\r
667TcpRetransmit (\r
668 IN TCP_CB *Tcb,\r
669 IN TCP_SEQNO Seq\r
670 )\r
671{\r
672 NET_BUF *Nbuf;\r
673 UINT32 Len;\r
674\r
675 //\r
676 // Compute the maxium length of retransmission. It is\r
677 // limited by three factors:\r
678 // 1. Less than SndMss\r
679 // 2. must in the current send window\r
680 // 3. will not change the boundaries of queued segments.\r
681 //\r
682 if (TCP_SEQ_LT (Tcb->SndWl2 + Tcb->SndWnd, Seq)) {\r
e48e37fc 683 DEBUG ((EFI_D_WARN, "TcpRetransmit: retransmission cancelled "\r
0e549d5b 684 "because send window too small for TCB %p\n", Tcb));\r
8a67d61d 685\r
686 return 0;\r
687 }\r
688\r
689 Len = TCP_SUB_SEQ (Tcb->SndWl2 + Tcb->SndWnd, Seq);\r
36ee91ca 690 Len = MIN (Len, Tcb->SndMss);\r
8a67d61d 691\r
692 Nbuf = TcpGetSegmentSndQue (Tcb, Seq, Len);\r
693 if (Nbuf == NULL) {\r
694 return -1;\r
695 }\r
696\r
697 ASSERT (TcpVerifySegment (Nbuf));\r
698\r
699 if (TcpTransmitSegment (Tcb, Nbuf) != 0) {\r
700 goto OnError;\r
701 }\r
702\r
703 //\r
704 // The retransmitted buffer may be on the SndQue,\r
705 // trim TCP head because all the buffer on SndQue\r
706 // are headless.\r
707 //\r
708 ASSERT (Nbuf->Tcp);\r
709 NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r
710 Nbuf->Tcp = NULL;\r
711\r
712 NetbufFree (Nbuf);\r
713 return 0;\r
714\r
715OnError:\r
716 if (Nbuf != NULL) {\r
717 NetbufFree (Nbuf);\r
718 }\r
719\r
720 return -1;\r
721}\r
722\r
723\r
724/**\r
725 Check whether to send data/SYN/FIN and piggy back an ACK.\r
726\r
727 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
728 @param Force Whether to ignore the sender's SWS avoidance algorithm and send\r
729 out data by force.\r
730\r
731 @return The number of bytes sent.\r
732\r
733**/\r
734INTN\r
735TcpToSendData (\r
736 IN TCP_CB *Tcb,\r
737 IN INTN Force\r
738 )\r
739{\r
740 UINT32 Len;\r
741 INTN Sent;\r
742 UINT8 Flag;\r
743 NET_BUF *Nbuf;\r
744 TCP_SEG *Seg;\r
745 TCP_SEQNO Seq;\r
746 TCP_SEQNO End;\r
747\r
748 ASSERT (Tcb && Tcb->Sk && (Tcb->State != TCP_LISTEN));\r
749\r
750 Sent = 0;\r
751\r
752 if ((Tcb->State == TCP_CLOSED) ||\r
753 TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT)) {\r
754\r
755 return 0;\r
756 }\r
757\r
758SEND_AGAIN:\r
759 //\r
760 // compute how much data can be sent\r
761 //\r
762 Len = TcpDataToSend (Tcb, Force);\r
763 Seq = Tcb->SndNxt;\r
764\r
765 Flag = mTcpOutFlag[Tcb->State];\r
766\r
767 if (Flag & TCP_FLG_SYN) {\r
768\r
769 Seq = Tcb->Iss;\r
770 Len = 0;\r
771 }\r
772\r
773 //\r
774 // only send a segment without data if SYN or\r
775 // FIN is set.\r
776 //\r
777 if ((Len == 0) && !(Flag & (TCP_FLG_SYN | TCP_FLG_FIN))) {\r
778 return Sent;\r
779 }\r
780\r
781 Nbuf = TcpGetSegment (Tcb, Seq, Len);\r
782\r
783 if (Nbuf == NULL) {\r
e48e37fc 784 DEBUG (\r
785 (EFI_D_ERROR,\r
0e549d5b 786 "TcpToSendData: failed to get a segment for TCB %p\n",\r
8a67d61d 787 Tcb)\r
788 );\r
789\r
790 goto OnError;\r
791 }\r
792\r
793 Seg = TCPSEG_NETBUF (Nbuf);\r
794\r
795 //\r
796 // Set the TcpSeg in Nbuf.\r
797 //\r
798 Len = Nbuf->TotalSize;\r
799 End = Seq + Len;\r
800 if (TCP_FLG_ON (Flag, TCP_FLG_SYN)) {\r
801 End++;\r
802 }\r
803\r
804 if (Flag & TCP_FLG_FIN) {\r
805 //\r
806 // Send FIN if all data is sent, and FIN is\r
807 // in the window\r
808 //\r
809 if ((TcpGetMaxSndNxt (Tcb) == Tcb->SndNxt) &&\r
810 (GET_SND_DATASIZE (Tcb->Sk) == 0) &&\r
811 TCP_SEQ_LT (End + 1, Tcb->SndWnd + Tcb->SndWl2)\r
812 ) {\r
813\r
e48e37fc 814 DEBUG ((EFI_D_INFO, "TcpToSendData: send FIN "\r
0e549d5b 815 "to peer for TCB %p in state %d\n", Tcb, Tcb->State));\r
8a67d61d 816\r
817 End++;\r
818 } else {\r
819 TCP_CLEAR_FLG (Flag, TCP_FLG_FIN);\r
820 }\r
821 }\r
822\r
823 Seg->Seq = Seq;\r
824 Seg->End = End;\r
825 Seg->Flag = Flag;\r
826\r
827 ASSERT (TcpVerifySegment (Nbuf));\r
828 ASSERT (TcpCheckSndQue (&Tcb->SndQue));\r
829\r
830 //\r
831 // don't send an empty segment here.\r
832 //\r
833 if (Seg->End == Seg->Seq) {\r
e48e37fc 834 DEBUG ((EFI_D_WARN, "TcpToSendData: created a empty"\r
0e549d5b 835 " segment for TCB %p, free it now\n", Tcb));\r
8a67d61d 836\r
837 NetbufFree (Nbuf);\r
838 return Sent;\r
839 }\r
840\r
841 if (TcpTransmitSegment (Tcb, Nbuf) != 0) {\r
842 //\r
843 // TODO: double check this\r
844 //\r
845 NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r
846 Nbuf->Tcp = NULL;\r
847\r
848 if (Flag & TCP_FLG_FIN) {\r
849 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT);\r
850 }\r
851\r
852 goto OnError;\r
853 }\r
854\r
855 Sent += TCP_SUB_SEQ (End, Seq);\r
856\r
857 //\r
858 // All the buffer in the SndQue is headless\r
859 //\r
860 ASSERT (Nbuf->Tcp);\r
861\r
862 NetbufTrim (Nbuf, (Nbuf->Tcp->HeadLen << 2), NET_BUF_HEAD);\r
863 Nbuf->Tcp = NULL;\r
864\r
865 NetbufFree (Nbuf);\r
866\r
867 //\r
868 // update status in TCB\r
869 //\r
870 Tcb->DelayedAck = 0;\r
871\r
872 if (Flag & TCP_FLG_FIN) {\r
873 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT);\r
874 }\r
875\r
876 if (TCP_SEQ_GT (End, Tcb->SndNxt)) {\r
877 Tcb->SndNxt = End;\r
878 }\r
879\r
880 if (!TCP_TIMER_ON (Tcb->EnabledTimer, TCP_TIMER_REXMIT)) {\r
881 TcpSetTimer (Tcb, TCP_TIMER_REXMIT, Tcb->Rto);\r
882 }\r
883\r
884 //\r
885 // Enable RTT measurement only if not in retransmit.\r
886 // Karn's algorithm reqires not to update RTT when in loss.\r
887 //\r
888 if ((Tcb->CongestState == TCP_CONGEST_OPEN) &&\r
889 !TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {\r
890\r
e48e37fc 891 DEBUG ((EFI_D_INFO, "TcpToSendData: set RTT measure "\r
0e549d5b 892 "sequence %d for TCB %p\n", Seq, Tcb));\r
8a67d61d 893\r
894 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);\r
895 Tcb->RttSeq = Seq;\r
896 Tcb->RttMeasure = 0;\r
897 }\r
898\r
899 if (Len == Tcb->SndMss) {\r
900 goto SEND_AGAIN;\r
901 }\r
902\r
903 return Sent;\r
904\r
905OnError:\r
906 if (Nbuf != NULL) {\r
907 NetbufFree (Nbuf);\r
908 }\r
909\r
910 return Sent;\r
911}\r
912\r
913\r
914/**\r
915 Send an ACK immediately.\r
916\r
917 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
918\r
919 @return None.\r
920\r
921**/\r
922VOID\r
923TcpSendAck (\r
924 IN TCP_CB *Tcb\r
925 )\r
926{\r
927 NET_BUF *Nbuf;\r
928 TCP_SEG *Seg;\r
929\r
930 Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r
931\r
932 if (Nbuf == NULL) {\r
933 return;\r
934 }\r
935\r
936 NetbufReserve (Nbuf, TCP_MAX_HEAD);\r
937\r
938 Seg = TCPSEG_NETBUF (Nbuf);\r
939 Seg->Seq = Tcb->SndNxt;\r
940 Seg->End = Tcb->SndNxt;\r
941 Seg->Flag = TCP_FLG_ACK;\r
942\r
943 if (TcpTransmitSegment (Tcb, Nbuf) == 0) {\r
944 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);\r
945 Tcb->DelayedAck = 0;\r
946 }\r
947\r
948 NetbufFree (Nbuf);\r
949}\r
950\r
951\r
952/**\r
953 Send a zero probe segment. It can be used by keepalive\r
954 and zero window probe.\r
955\r
956 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
957\r
958 @retval 0 The zero probe segment was sent out successfully.\r
959 @retval other Error condition occurred.\r
960\r
961**/\r
962INTN\r
963TcpSendZeroProbe (\r
964 IN TCP_CB *Tcb\r
965 )\r
966{\r
967 NET_BUF *Nbuf;\r
968 TCP_SEG *Seg;\r
969 INTN Result;\r
970\r
971 Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r
972\r
973 if (Nbuf == NULL) {\r
974 return -1;\r
975 }\r
976\r
977 NetbufReserve (Nbuf, TCP_MAX_HEAD);\r
978\r
979 //\r
980 // SndNxt-1 is out of window. The peer should respond\r
981 // with an ACK.\r
982 //\r
983 Seg = TCPSEG_NETBUF (Nbuf);\r
984 Seg->Seq = Tcb->SndNxt - 1;\r
985 Seg->End = Tcb->SndNxt - 1;\r
986 Seg->Flag = TCP_FLG_ACK;\r
987\r
988 Result = TcpTransmitSegment (Tcb, Nbuf);\r
989 NetbufFree (Nbuf);\r
990\r
991 return Result;\r
992}\r
993\r
994\r
995/**\r
996 Check whether to send an ACK or delayed ACK.\r
997\r
998 @param Tcb Pointer to the TCP_CB of this TCP instance.\r
999\r
1000 @return None.\r
1001\r
1002**/\r
1003VOID\r
1004TcpToSendAck (\r
1005 IN TCP_CB *Tcb\r
1006 )\r
1007{\r
4eb65aff 1008 UINT32 TcpNow;\r
1009\r
1010 TcpNow = TcpRcvWinNow (Tcb);\r
8a67d61d 1011 //\r
1012 // Generally, TCP should send a delayed ACK unless:\r
1013 // 1. ACK at least every other FULL sized segment received,\r
1014 // 2. Packets received out of order\r
1015 // 3. Receiving window is open\r
1016 //\r
1017 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW) ||\r
1018 (Tcb->DelayedAck >= 1) ||\r
4eb65aff 1019 (TcpNow > TcpRcvWinOld (Tcb))\r
8a67d61d 1020 ) {\r
1021 TcpSendAck (Tcb);\r
1022 return;\r
1023 }\r
1024\r
e48e37fc 1025 DEBUG ((EFI_D_INFO, "TcpToSendAck: scheduled a delayed"\r
0e549d5b 1026 " ACK for TCB %p\n", Tcb));\r
8a67d61d 1027\r
1028 //\r
1029 // schedule a delayed ACK\r
1030 //\r
1031 Tcb->DelayedAck++;\r
1032}\r
1033\r
1034\r
1035/**\r
1036 Send a RESET segment in response to the segment received.\r
1037\r
1038 @param Tcb Pointer to the TCP_CB of this TCP instance, may be NULL.\r
1039 @param Head TCP header of the segment that triggers the reset.\r
1040 @param Len Length of the segment that triggers the reset.\r
1041 @param Local Local IP address.\r
1042 @param Remote Remote peer's IP address.\r
1043\r
1044 @retval 0 A reset is sent or no need to send it.\r
1045 @retval -1 No reset is sent.\r
1046\r
1047**/\r
1048INTN\r
1049TcpSendReset (\r
1050 IN TCP_CB *Tcb,\r
1051 IN TCP_HEAD *Head,\r
1052 IN INT32 Len,\r
1053 IN UINT32 Local,\r
1054 IN UINT32 Remote\r
1055 )\r
1056{\r
1057 NET_BUF *Nbuf;\r
1058 TCP_HEAD *Nhead;\r
1059 UINT16 HeadSum;\r
1060\r
1061 //\r
1062 // Don't respond to a Reset with reset\r
1063 //\r
1064 if (Head->Flag & TCP_FLG_RST) {\r
1065 return 0;\r
1066 }\r
1067\r
1068 Nbuf = NetbufAlloc (TCP_MAX_HEAD);\r
1069\r
1070 if (Nbuf == NULL) {\r
1071 return -1;\r
1072 }\r
1073\r
1074 Nhead = (TCP_HEAD *) NetbufAllocSpace (\r
1075 Nbuf,\r
1076 sizeof (TCP_HEAD),\r
1077 NET_BUF_TAIL\r
1078 );\r
1079\r
1080 ASSERT (Nhead != NULL);\r
1081\r
1082 Nbuf->Tcp = Nhead;\r
1083 Nhead->Flag = TCP_FLG_RST;\r
1084\r
1085 //\r
1086 // Derive Seq/ACK from the segment if no TCB\r
1087 // associated with it, otherwise from the Tcb\r
1088 //\r
1089 if (Tcb == NULL) {\r
1090\r
1091 if (TCP_FLG_ON (Head->Flag, TCP_FLG_ACK)) {\r
1092 Nhead->Seq = Head->Ack;\r
1093 Nhead->Ack = 0;\r
1094 } else {\r
1095 Nhead->Seq = 0;\r
1096 TCP_SET_FLG (Nhead->Flag, TCP_FLG_ACK);\r
1097 Nhead->Ack = HTONL (NTOHL (Head->Seq) + Len);\r
1098 }\r
1099 } else {\r
1100\r
1101 Nhead->Seq = HTONL (Tcb->SndNxt);\r
1102 Nhead->Ack = HTONL (Tcb->RcvNxt);\r
1103 TCP_SET_FLG (Nhead->Flag, TCP_FLG_ACK);\r
1104 }\r
1105\r
1106 Nhead->SrcPort = Head->DstPort;\r
1107 Nhead->DstPort = Head->SrcPort;\r
1108 Nhead->HeadLen = (sizeof (TCP_HEAD) >> 2);\r
1109 Nhead->Res = 0;\r
1110 Nhead->Wnd = HTONS (0xFFFF);\r
1111 Nhead->Checksum = 0;\r
1112 Nhead->Urg = 0;\r
1113\r
1114 HeadSum = NetPseudoHeadChecksum (Local, Remote, 6, 0);\r
1115 Nhead->Checksum = TcpChecksum (Nbuf, HeadSum);\r
1116\r
1117 TcpSendIpPacket (Tcb, Nbuf, Local, Remote);\r
1118\r
1119 NetbufFree (Nbuf);\r
1120 return 0;\r
1121}\r
1122\r
1123\r
1124/**\r
1125 Verify that the segment is in good shape.\r
1126\r
1127 @param Nbuf Buffer that contains the segment to be checked.\r
1128\r
1129 @retval 0 The segment is broken.\r
1130 @retval 1 The segment is in good shape.\r
1131\r
1132**/\r
1133INTN\r
1134TcpVerifySegment (\r
1135 IN NET_BUF *Nbuf\r
1136 )\r
1137{\r
1138 TCP_HEAD *Head;\r
1139 TCP_SEG *Seg;\r
1140 UINT32 Len;\r
1141\r
1142 if (Nbuf == NULL) {\r
1143 return 1;\r
1144 }\r
1145\r
1146 NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE);\r
1147\r
1148 Seg = TCPSEG_NETBUF (Nbuf);\r
1149 Len = Nbuf->TotalSize;\r
1150 Head = Nbuf->Tcp;\r
1151\r
1152 if (Head != NULL) {\r
1153 if (Head->Flag != Seg->Flag) {\r
1154 return 0;\r
1155 }\r
1156\r
1157 Len -= (Head->HeadLen << 2);\r
1158 }\r
1159\r
1160 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {\r
1161 Len++;\r
1162 }\r
1163\r
1164 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {\r
1165 Len++;\r
1166 }\r
1167\r
1168 if (Seg->Seq + Len != Seg->End) {\r
1169 return 0;\r
1170 }\r
1171\r
1172 return 1;\r
1173}\r
1174\r
1175\r
1176/**\r
1177 Verify that all the segments in SndQue are in good shape.\r
1178\r
1179 @param Head Pointer to the head node of the SndQue.\r
1180\r
1181 @retval 0 At least one segment is broken.\r
1182 @retval 1 All segments in the specific queue are in good shape.\r
1183\r
1184**/\r
1185INTN\r
1186TcpCheckSndQue (\r
e48e37fc 1187 IN LIST_ENTRY *Head\r
8a67d61d 1188 )\r
1189{\r
e48e37fc 1190 LIST_ENTRY *Entry;\r
8a67d61d 1191 NET_BUF *Nbuf;\r
1192 TCP_SEQNO Seq;\r
1193\r
e48e37fc 1194 if (IsListEmpty (Head)) {\r
8a67d61d 1195 return 1;\r
1196 }\r
1197 //\r
1198 // Initialize the Seq\r
1199 //\r
1200 Entry = Head->ForwardLink;\r
1201 Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r
1202 Seq = TCPSEG_NETBUF (Nbuf)->Seq;\r
1203\r
1204 NET_LIST_FOR_EACH (Entry, Head) {\r
1205 Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);\r
1206\r
1207 if (TcpVerifySegment (Nbuf) == 0) {\r
1208 return 0;\r
1209 }\r
1210\r
1211 //\r
1212 // All the node in the SndQue should has:\r
1213 // SEG.SEQ = LAST_SEG.END\r
1214 //\r
1215 if (Seq != TCPSEG_NETBUF (Nbuf)->Seq) {\r
1216 return 0;\r
1217 }\r
1218\r
1219 Seq = TCPSEG_NETBUF (Nbuf)->End;\r
1220 }\r
1221\r
1222 return 1;\r
1223}\r