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[mirror_edk2.git] / NetworkPkg / TcpDxe / TcpInput.c
1 /** @file
2 TCP input process routines.
3
4 Copyright (c) 2009 - 2016 Intel Corporation. All rights reserved.<BR>
5
6 This program and the accompanying materials
7 are licensed and made available under the terms and conditions of the BSD License
8 which accompanies this distribution. The full text of the license may be found at
9 http://opensource.org/licenses/bsd-license.php.
10
11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
13
14 **/
15
16 #include "TcpMain.h"
17
18 /**
19 Check whether the sequence number of the incoming segment is acceptable.
20
21 @param[in] Tcb Pointer to the TCP_CB of this TCP instance.
22 @param[in] Seg Pointer to the incoming segment.
23
24 @retval 1 The sequence number is acceptable.
25 @retval 0 The sequence number is not acceptable.
26
27 **/
28 INTN
29 TcpSeqAcceptable (
30 IN TCP_CB *Tcb,
31 IN TCP_SEG *Seg
32 )
33 {
34 return (TCP_SEQ_LEQ (Tcb->RcvWl2, Seg->End) &&
35 TCP_SEQ_LT (Seg->Seq, Tcb->RcvWl2 + Tcb->RcvWnd));
36 }
37
38 /**
39 NewReno fast recovery defined in RFC3782.
40
41 @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
42 @param[in] Seg Segment that triggers the fast recovery.
43
44 **/
45 VOID
46 TcpFastRecover (
47 IN OUT TCP_CB *Tcb,
48 IN TCP_SEG *Seg
49 )
50 {
51 UINT32 FlightSize;
52 UINT32 Acked;
53
54 //
55 // Step 1: Three duplicate ACKs and not in fast recovery
56 //
57 if (Tcb->CongestState != TCP_CONGEST_RECOVER) {
58
59 //
60 // Step 1A: Invoking fast retransmission.
61 //
62 FlightSize = TCP_SUB_SEQ (Tcb->SndNxt, Tcb->SndUna);
63
64 Tcb->Ssthresh = MAX (FlightSize >> 1, (UINT32) (2 * Tcb->SndMss));
65 Tcb->Recover = Tcb->SndNxt;
66
67 Tcb->CongestState = TCP_CONGEST_RECOVER;
68 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);
69
70 //
71 // Step 2: Entering fast retransmission
72 //
73 TcpRetransmit (Tcb, Tcb->SndUna);
74 Tcb->CWnd = Tcb->Ssthresh + 3 * Tcb->SndMss;
75
76 DEBUG (
77 (EFI_D_INFO,
78 "TcpFastRecover: enter fast retransmission for TCB %p, recover point is %d\n",
79 Tcb,
80 Tcb->Recover)
81 );
82 return;
83 }
84
85 //
86 // During fast recovery, execute Step 3, 4, 5 of RFC3782
87 //
88 if (Seg->Ack == Tcb->SndUna) {
89
90 //
91 // Step 3: Fast Recovery,
92 // If this is a duplicated ACK, increse Cwnd by SMSS.
93 //
94
95 // Step 4 is skipped here only to be executed later
96 // by TcpToSendData
97 //
98 Tcb->CWnd += Tcb->SndMss;
99 DEBUG (
100 (EFI_D_INFO,
101 "TcpFastRecover: received another duplicated ACK (%d) for TCB %p\n",
102 Seg->Ack,
103 Tcb)
104 );
105
106 } else {
107
108 //
109 // New data is ACKed, check whether it is a
110 // full ACK or partial ACK
111 //
112 if (TCP_SEQ_GEQ (Seg->Ack, Tcb->Recover)) {
113
114 //
115 // Step 5 - Full ACK:
116 // deflate the congestion window, and exit fast recovery
117 //
118 FlightSize = TCP_SUB_SEQ (Tcb->SndNxt, Tcb->SndUna);
119
120 Tcb->CWnd = MIN (Tcb->Ssthresh, FlightSize + Tcb->SndMss);
121
122 Tcb->CongestState = TCP_CONGEST_OPEN;
123 DEBUG (
124 (EFI_D_INFO,
125 "TcpFastRecover: received a full ACK(%d) for TCB %p, exit fast recovery\n",
126 Seg->Ack,
127 Tcb)
128 );
129
130 } else {
131
132 //
133 // Step 5 - Partial ACK:
134 // fast retransmit the first unacknowledge field
135 // , then deflate the CWnd
136 //
137 TcpRetransmit (Tcb, Seg->Ack);
138 Acked = TCP_SUB_SEQ (Seg->Ack, Tcb->SndUna);
139
140 //
141 // Deflate the CWnd by the amount of new data
142 // ACKed by SEG.ACK. If more than one SMSS data
143 // is ACKed, add back SMSS byte to CWnd after
144 //
145 if (Acked >= Tcb->SndMss) {
146 Acked -= Tcb->SndMss;
147
148 }
149
150 Tcb->CWnd -= Acked;
151
152 DEBUG (
153 (EFI_D_INFO,
154 "TcpFastRecover: received a partial ACK(%d) for TCB %p\n",
155 Seg->Ack,
156 Tcb)
157 );
158
159 }
160 }
161 }
162
163 /**
164 NewReno fast loss recovery defined in RFC3792.
165
166 @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
167 @param[in] Seg Segment that triggers the fast loss recovery.
168
169 **/
170 VOID
171 TcpFastLossRecover (
172 IN OUT TCP_CB *Tcb,
173 IN TCP_SEG *Seg
174 )
175 {
176 if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {
177
178 //
179 // New data is ACKed, check whether it is a
180 // full ACK or partial ACK
181 //
182 if (TCP_SEQ_GEQ (Seg->Ack, Tcb->LossRecover)) {
183
184 //
185 // Full ACK: exit the loss recovery.
186 //
187 Tcb->LossTimes = 0;
188 Tcb->CongestState = TCP_CONGEST_OPEN;
189
190 DEBUG (
191 (EFI_D_INFO,
192 "TcpFastLossRecover: received a full ACK(%d) for TCB %p\n",
193 Seg->Ack,
194 Tcb)
195 );
196
197 } else {
198
199 //
200 // Partial ACK:
201 // fast retransmit the first unacknowledge field.
202 //
203 TcpRetransmit (Tcb, Seg->Ack);
204 DEBUG (
205 (EFI_D_INFO,
206 "TcpFastLossRecover: received a partial ACK(%d) for TCB %p\n",
207 Seg->Ack,
208 Tcb)
209 );
210 }
211 }
212 }
213
214 /**
215 Compute the RTT as specified in RFC2988.
216
217 @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
218 @param[in] Measure Currently measured RTT in heartbeats.
219
220 **/
221 VOID
222 TcpComputeRtt (
223 IN OUT TCP_CB *Tcb,
224 IN UINT32 Measure
225 )
226 {
227 INT32 Var;
228
229 //
230 // Step 2.3: Compute the RTO for subsequent RTT measurement.
231 //
232 if (Tcb->SRtt != 0) {
233
234 Var = Tcb->SRtt - (Measure << TCP_RTT_SHIFT);
235
236 if (Var < 0) {
237 Var = -Var;
238 }
239
240 Tcb->RttVar = (3 * Tcb->RttVar + Var) >> 2;
241 Tcb->SRtt = 7 * (Tcb->SRtt >> 3) + Measure;
242
243 } else {
244 //
245 // Step 2.2: compute the first RTT measure
246 //
247 Tcb->SRtt = Measure << TCP_RTT_SHIFT;
248 Tcb->RttVar = Measure << (TCP_RTT_SHIFT - 1);
249 }
250
251 Tcb->Rto = (Tcb->SRtt + MAX (8, 4 * Tcb->RttVar)) >> TCP_RTT_SHIFT;
252
253 //
254 // Step 2.4: Limit the RTO to at least 1 second
255 // Step 2.5: Limit the RTO to a maxium value that
256 // is at least 60 second
257 //
258 if (Tcb->Rto < TCP_RTO_MIN) {
259 Tcb->Rto = TCP_RTO_MIN;
260
261 } else if (Tcb->Rto > TCP_RTO_MAX) {
262 Tcb->Rto = TCP_RTO_MAX;
263
264 }
265
266 DEBUG (
267 (EFI_D_INFO,
268 "TcpComputeRtt: new RTT for TCB %p computed SRTT: %d RTTVAR: %d RTO: %d\n",
269 Tcb,
270 Tcb->SRtt,
271 Tcb->RttVar,
272 Tcb->Rto)
273 );
274
275 }
276
277 /**
278 Trim the data; SYN and FIN to fit into the window defined by Left and Right.
279
280 @param[in] Nbuf The buffer that contains a received TCP segment without an IP header.
281 @param[in] Left The sequence number of the window's left edge.
282 @param[in] Right The sequence number of the window's right edge.
283
284 **/
285 VOID
286 TcpTrimSegment (
287 IN NET_BUF *Nbuf,
288 IN TCP_SEQNO Left,
289 IN TCP_SEQNO Right
290 )
291 {
292 TCP_SEG *Seg;
293 TCP_SEQNO Urg;
294 UINT32 Drop;
295
296 Seg = TCPSEG_NETBUF (Nbuf);
297
298 //
299 // If the segment is completely out of window,
300 // truncate every thing, include SYN and FIN.
301 //
302 if (TCP_SEQ_LEQ (Seg->End, Left) || TCP_SEQ_LEQ (Right, Seg->Seq)) {
303
304 TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_SYN);
305 TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_FIN);
306
307 Seg->Seq = Seg->End;
308 NetbufTrim (Nbuf, Nbuf->TotalSize, NET_BUF_HEAD);
309 return;
310 }
311
312 //
313 // Adjust the buffer header
314 //
315 if (TCP_SEQ_LT (Seg->Seq, Left)) {
316
317 Drop = TCP_SUB_SEQ (Left, Seg->Seq);
318 Urg = Seg->Seq + Seg->Urg;
319 Seg->Seq = Left;
320
321 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
322 TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_SYN);
323 Drop--;
324 }
325
326 //
327 // Adjust the urgent point
328 //
329 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_URG)) {
330
331 if (TCP_SEQ_LT (Urg, Seg->Seq)) {
332
333 TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_URG);
334 } else {
335 Seg->Urg = (UINT16) TCP_SUB_SEQ (Urg, Seg->Seq);
336 }
337 }
338
339 if (Drop != 0) {
340 NetbufTrim (Nbuf, Drop, NET_BUF_HEAD);
341 }
342 }
343
344 //
345 // Adjust the buffer tail
346 //
347 if (TCP_SEQ_GT (Seg->End, Right)) {
348
349 Drop = TCP_SUB_SEQ (Seg->End, Right);
350 Seg->End = Right;
351
352 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {
353 TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_FIN);
354 Drop--;
355 }
356
357 if (Drop != 0) {
358 NetbufTrim (Nbuf, Drop, NET_BUF_TAIL);
359 }
360 }
361
362 ASSERT (TcpVerifySegment (Nbuf) != 0);
363 }
364
365 /**
366 Trim off the data outside the tcb's receive window.
367
368 @param[in] Tcb Pointer to the TCP_CB of this TCP instance.
369 @param[in] Nbuf Pointer to the NET_BUF containing the received tcp segment.
370
371 **/
372 VOID
373 TcpTrimInWnd (
374 IN TCP_CB *Tcb,
375 IN NET_BUF *Nbuf
376 )
377 {
378 TcpTrimSegment (Nbuf, Tcb->RcvNxt, Tcb->RcvWl2 + Tcb->RcvWnd);
379 }
380
381 /**
382 Process the data and FIN flag, and check whether to deliver
383 data to the socket layer.
384
385 @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
386
387 @retval 0 No error occurred to deliver data.
388 @retval -1 An error condition occurred. The proper response is to reset the
389 connection.
390
391 **/
392 INTN
393 TcpDeliverData (
394 IN OUT TCP_CB *Tcb
395 )
396 {
397 LIST_ENTRY *Entry;
398 NET_BUF *Nbuf;
399 TCP_SEQNO Seq;
400 TCP_SEG *Seg;
401 UINT32 Urgent;
402
403 ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));
404
405 //
406 // make sure there is some data queued,
407 // and TCP is in a proper state
408 //
409 if (IsListEmpty (&Tcb->RcvQue) || !TCP_CONNECTED (Tcb->State)) {
410
411 return 0;
412 }
413
414 //
415 // Deliver data to the socket layer
416 //
417 Entry = Tcb->RcvQue.ForwardLink;
418 Seq = Tcb->RcvNxt;
419
420 while (Entry != &Tcb->RcvQue) {
421 Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);
422 Seg = TCPSEG_NETBUF (Nbuf);
423
424 ASSERT (TcpVerifySegment (Nbuf) != 0);
425 ASSERT (Nbuf->Tcp == NULL);
426
427 if (TCP_SEQ_GT (Seg->Seq, Seq)) {
428 break;
429 }
430
431 Entry = Entry->ForwardLink;
432 Seq = Seg->End;
433 Tcb->RcvNxt = Seq;
434
435 RemoveEntryList (&Nbuf->List);
436
437 //
438 // RFC793 Eighth step: process FIN in sequence
439 //
440 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {
441
442 //
443 // The peer sends to us junky data after FIN,
444 // reset the connection.
445 //
446 if (!IsListEmpty (&Tcb->RcvQue)) {
447 DEBUG (
448 (EFI_D_ERROR,
449 "TcpDeliverData: data received after FIN from peer of TCB %p, reset connection\n",
450 Tcb)
451 );
452
453 NetbufFree (Nbuf);
454 return -1;
455 }
456
457 DEBUG (
458 (EFI_D_INFO,
459 "TcpDeliverData: processing FIN from peer of TCB %p\n",
460 Tcb)
461 );
462
463 switch (Tcb->State) {
464 case TCP_SYN_RCVD:
465 case TCP_ESTABLISHED:
466
467 TcpSetState (Tcb, TCP_CLOSE_WAIT);
468 break;
469
470 case TCP_FIN_WAIT_1:
471
472 if (!TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
473
474 TcpSetState (Tcb, TCP_CLOSING);
475 break;
476 }
477
478 //
479 // fall through
480 //
481 case TCP_FIN_WAIT_2:
482
483 TcpSetState (Tcb, TCP_TIME_WAIT);
484 TcpClearAllTimer (Tcb);
485
486 if (Tcb->TimeWaitTimeout != 0) {
487
488 TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);
489 } else {
490
491 DEBUG (
492 (EFI_D_WARN,
493 "Connection closed immediately because app disables TIME_WAIT timer for %p\n",
494 Tcb)
495 );
496
497 TcpSendAck (Tcb);
498 TcpClose (Tcb);
499 }
500 break;
501
502 case TCP_CLOSE_WAIT:
503 case TCP_CLOSING:
504 case TCP_LAST_ACK:
505 case TCP_TIME_WAIT:
506 //
507 // The peer sends to us junk FIN byte. Discard
508 // the buffer then reset the connection
509 //
510 NetbufFree (Nbuf);
511 return -1;
512 break;
513 default:
514 break;
515 }
516
517 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
518
519 Seg->End--;
520 }
521
522 //
523 // Don't delay the ack if PUSH flag is on.
524 //
525 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_PSH)) {
526
527 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
528 }
529
530 if (Nbuf->TotalSize != 0) {
531 Urgent = 0;
532
533 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG) &&
534 TCP_SEQ_LEQ (Seg->Seq, Tcb->RcvUp))
535 {
536
537 if (TCP_SEQ_LEQ (Seg->End, Tcb->RcvUp)) {
538 Urgent = Nbuf->TotalSize;
539 } else {
540 Urgent = TCP_SUB_SEQ (Tcb->RcvUp, Seg->Seq) + 1;
541 }
542 }
543
544 SockDataRcvd (Tcb->Sk, Nbuf, Urgent);
545 }
546
547 if (TCP_FIN_RCVD (Tcb->State)) {
548
549 SockNoMoreData (Tcb->Sk);
550 }
551
552 NetbufFree (Nbuf);
553 }
554
555 return 0;
556 }
557
558 /**
559 Store the data into the reassemble queue.
560
561 @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
562 @param[in] Nbuf Pointer to the buffer containing the data to be queued.
563
564 **/
565 VOID
566 TcpQueueData (
567 IN OUT TCP_CB *Tcb,
568 IN NET_BUF *Nbuf
569 )
570 {
571 TCP_SEG *Seg;
572 LIST_ENTRY *Head;
573 LIST_ENTRY *Prev;
574 LIST_ENTRY *Cur;
575 NET_BUF *Node;
576
577 ASSERT ((Tcb != NULL) && (Nbuf != NULL) && (Nbuf->Tcp == NULL));
578
579 NET_GET_REF (Nbuf);
580
581 Seg = TCPSEG_NETBUF (Nbuf);
582 Head = &Tcb->RcvQue;
583
584 //
585 // Fast path to process normal case. That is,
586 // no out-of-order segments are received.
587 //
588 if (IsListEmpty (Head)) {
589
590 InsertTailList (Head, &Nbuf->List);
591 return;
592 }
593
594 //
595 // Find the point to insert the buffer
596 //
597 for (Prev = Head, Cur = Head->ForwardLink;
598 Cur != Head;
599 Prev = Cur, Cur = Cur->ForwardLink) {
600
601 Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);
602
603 if (TCP_SEQ_LT (Seg->Seq, TCPSEG_NETBUF (Node)->Seq)) {
604 break;
605 }
606 }
607
608 //
609 // Check whether the current segment overlaps with the
610 // previous segment.
611 //
612 if (Prev != Head) {
613 Node = NET_LIST_USER_STRUCT (Prev, NET_BUF, List);
614
615 if (TCP_SEQ_LT (Seg->Seq, TCPSEG_NETBUF (Node)->End)) {
616
617 if (TCP_SEQ_LEQ (Seg->End, TCPSEG_NETBUF (Node)->End)) {
618
619 NetbufFree (Nbuf);
620 return;
621 }
622
623 TcpTrimSegment (Nbuf, TCPSEG_NETBUF (Node)->End, Seg->End);
624 }
625 }
626
627 InsertHeadList (Prev, &Nbuf->List);
628
629 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
630
631 //
632 // Check the segments after the insert point.
633 //
634 while (Cur != Head) {
635 Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);
636
637 if (TCP_SEQ_LEQ (TCPSEG_NETBUF (Node)->End, Seg->End)) {
638
639 Cur = Cur->ForwardLink;
640
641 RemoveEntryList (&Node->List);
642 NetbufFree (Node);
643 continue;
644 }
645
646 if (TCP_SEQ_LT (TCPSEG_NETBUF (Node)->Seq, Seg->End)) {
647
648 if (TCP_SEQ_LEQ (TCPSEG_NETBUF (Node)->Seq, Seg->Seq)) {
649
650 RemoveEntryList (&Nbuf->List);
651 NetbufFree (Nbuf);
652 return;
653 }
654
655 TcpTrimSegment (Nbuf, Seg->Seq, TCPSEG_NETBUF (Node)->Seq);
656 break;
657 }
658
659 Cur = Cur->ForwardLink;
660 }
661 }
662
663
664 /**
665 Adjust the send queue or the retransmit queue.
666
667 @param[in] Tcb Pointer to the TCP_CB of this TCP instance.
668 @param[in] Ack The acknowledge seuqence number of the received segment.
669
670 **/
671 VOID
672 TcpAdjustSndQue (
673 IN TCP_CB *Tcb,
674 IN TCP_SEQNO Ack
675 )
676 {
677 LIST_ENTRY *Head;
678 LIST_ENTRY *Cur;
679 NET_BUF *Node;
680 TCP_SEG *Seg;
681
682 Head = &Tcb->SndQue;
683 Cur = Head->ForwardLink;
684
685 while (Cur != Head) {
686 Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);
687 Seg = TCPSEG_NETBUF (Node);
688
689 if (TCP_SEQ_GEQ (Seg->Seq, Ack)) {
690 break;
691 }
692
693 //
694 // Remove completely ACKed segments
695 //
696 if (TCP_SEQ_LEQ (Seg->End, Ack)) {
697 Cur = Cur->ForwardLink;
698
699 RemoveEntryList (&Node->List);
700 NetbufFree (Node);
701 continue;
702 }
703
704 TcpTrimSegment (Node, Ack, Seg->End);
705 break;
706 }
707 }
708
709 /**
710 Process the received TCP segments.
711
712 @param[in] Nbuf Buffer that contains received a TCP segment without an IP header.
713 @param[in] Src Source address of the segment, or the peer's IP address.
714 @param[in] Dst Destination address of the segment, or the local end's IP
715 address.
716 @param[in] Version IP_VERSION_4 indicates IP4 stack. IP_VERSION_6 indicates
717 IP6 stack.
718
719 @retval 0 Segment processed successfully. It is either accepted or
720 discarded. However, no connection is reset by the segment.
721 @retval -1 A connection is reset by the segment.
722
723 **/
724 INTN
725 TcpInput (
726 IN NET_BUF *Nbuf,
727 IN EFI_IP_ADDRESS *Src,
728 IN EFI_IP_ADDRESS *Dst,
729 IN UINT8 Version
730 )
731 {
732 TCP_CB *Tcb;
733 TCP_CB *Parent;
734 TCP_OPTION Option;
735 TCP_HEAD *Head;
736 INT32 Len;
737 TCP_SEG *Seg;
738 TCP_SEQNO Right;
739 TCP_SEQNO Urg;
740 UINT16 Checksum;
741
742 ASSERT ((Version == IP_VERSION_4) || (Version == IP_VERSION_6));
743
744 NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE);
745
746 Parent = NULL;
747 Tcb = NULL;
748
749 Head = (TCP_HEAD *) NetbufGetByte (Nbuf, 0, NULL);
750 ASSERT (Head != NULL);
751
752 if (Nbuf->TotalSize < sizeof (TCP_HEAD)) {
753 DEBUG ((EFI_D_INFO, "TcpInput: received a malformed packet\n"));
754 goto DISCARD;
755 }
756
757 Len = Nbuf->TotalSize - (Head->HeadLen << 2);
758
759 if ((Head->HeadLen < 5) || (Len < 0)) {
760
761 DEBUG ((EFI_D_INFO, "TcpInput: received a malformed packet\n"));
762
763 goto DISCARD;
764 }
765
766 if (Version == IP_VERSION_4) {
767 Checksum = NetPseudoHeadChecksum (Src->Addr[0], Dst->Addr[0], 6, 0);
768 } else {
769 Checksum = NetIp6PseudoHeadChecksum (&Src->v6, &Dst->v6, 6, 0);
770 }
771
772 Checksum = TcpChecksum (Nbuf, Checksum);
773
774 if (Checksum != 0) {
775 DEBUG ((EFI_D_ERROR, "TcpInput: received a checksum error packet\n"));
776 goto DISCARD;
777 }
778
779 if (TCP_FLG_ON (Head->Flag, TCP_FLG_SYN)) {
780 Len++;
781 }
782
783 if (TCP_FLG_ON (Head->Flag, TCP_FLG_FIN)) {
784 Len++;
785 }
786
787 Tcb = TcpLocateTcb (
788 Head->DstPort,
789 Dst,
790 Head->SrcPort,
791 Src,
792 Version,
793 (BOOLEAN) TCP_FLG_ON (Head->Flag, TCP_FLG_SYN)
794 );
795
796 if ((Tcb == NULL) || (Tcb->State == TCP_CLOSED)) {
797 DEBUG ((EFI_D_INFO, "TcpInput: send reset because no TCB found\n"));
798
799 Tcb = NULL;
800 goto SEND_RESET;
801 }
802
803 Seg = TcpFormatNetbuf (Tcb, Nbuf);
804
805 //
806 // RFC1122 recommended reaction to illegal option
807 // (in fact, an illegal option length) is reset.
808 //
809 if (TcpParseOption (Nbuf->Tcp, &Option) == -1) {
810 DEBUG (
811 (EFI_D_ERROR,
812 "TcpInput: reset the peer because of malformed option for TCB %p\n",
813 Tcb)
814 );
815
816 goto SEND_RESET;
817 }
818
819 //
820 // From now on, the segment is headless
821 //
822 NetbufTrim (Nbuf, (Head->HeadLen << 2), NET_BUF_HEAD);
823 Nbuf->Tcp = NULL;
824
825 //
826 // Process the segment in LISTEN state.
827 //
828 if (Tcb->State == TCP_LISTEN) {
829 //
830 // First step: Check RST
831 //
832 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
833 DEBUG (
834 (EFI_D_WARN,
835 "TcpInput: discard a reset segment for TCB %p in listening\n",
836 Tcb)
837 );
838
839 goto DISCARD;
840 }
841
842 //
843 // Second step: Check ACK.
844 // Any ACK sent to TCP in LISTEN is reseted.
845 //
846 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
847 DEBUG (
848 (EFI_D_WARN,
849 "TcpInput: send reset because of segment with ACK for TCB %p in listening\n",
850 Tcb)
851 );
852
853 goto SEND_RESET;
854 }
855
856 //
857 // Third step: Check SYN
858 //
859 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
860 //
861 // create a child TCB to handle the data
862 //
863 Parent = Tcb;
864
865 Tcb = TcpCloneTcb (Parent);
866 if (Tcb == NULL) {
867 DEBUG (
868 (EFI_D_ERROR,
869 "TcpInput: discard a segment because failed to clone a child for TCB %p\n",
870 Tcb)
871 );
872
873 goto DISCARD;
874 }
875
876 DEBUG (
877 (EFI_D_INFO,
878 "TcpInput: create a child for TCB %p in listening\n",
879 Tcb)
880 );
881
882 //
883 // init the TCB structure
884 //
885 IP6_COPY_ADDRESS (&Tcb->LocalEnd.Ip, Dst);
886 IP6_COPY_ADDRESS (&Tcb->RemoteEnd.Ip, Src);
887 Tcb->LocalEnd.Port = Head->DstPort;
888 Tcb->RemoteEnd.Port = Head->SrcPort;
889
890 TcpInitTcbLocal (Tcb);
891 TcpInitTcbPeer (Tcb, Seg, &Option);
892
893 TcpSetState (Tcb, TCP_SYN_RCVD);
894 TcpSetTimer (Tcb, TCP_TIMER_CONNECT, Tcb->ConnectTimeout);
895 TcpTrimInWnd (Tcb, Nbuf);
896
897 goto StepSix;
898 }
899
900 goto DISCARD;
901
902 } else if (Tcb->State == TCP_SYN_SENT) {
903 //
904 // First step: Check ACK bit
905 //
906 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK) && (Seg->Ack != Tcb->Iss + 1)) {
907
908 DEBUG (
909 (EFI_D_WARN,
910 "TcpInput: send reset because of wrong ACK received for TCB %p in SYN_SENT\n",
911 Tcb)
912 );
913
914 goto SEND_RESET;
915 }
916
917 //
918 // Second step: Check RST bit
919 //
920 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
921
922 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
923
924 DEBUG (
925 (EFI_D_WARN,
926 "TcpInput: connection reset by peer for TCB %p in SYN_SENT\n",
927 Tcb)
928 );
929
930 SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
931 goto DROP_CONNECTION;
932 } else {
933
934 DEBUG (
935 (EFI_D_WARN,
936 "TcpInput: discard a reset segment because of no ACK for TCB %p in SYN_SENT\n",
937 Tcb)
938 );
939
940 goto DISCARD;
941 }
942 }
943
944 //
945 // Third step: Check security and precedence. Skipped
946 //
947
948 //
949 // Fourth step: Check SYN. Pay attention to simultaneous open
950 //
951 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
952
953 TcpInitTcbPeer (Tcb, Seg, &Option);
954
955 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
956
957 Tcb->SndUna = Seg->Ack;
958 }
959
960 TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
961
962 if (TCP_SEQ_GT (Tcb->SndUna, Tcb->Iss)) {
963
964 TcpSetState (Tcb, TCP_ESTABLISHED);
965
966 TcpClearTimer (Tcb, TCP_TIMER_CONNECT);
967 TcpDeliverData (Tcb);
968
969 if ((Tcb->CongestState == TCP_CONGEST_OPEN) &&
970 TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON))
971 {
972
973 TcpComputeRtt (Tcb, Tcb->RttMeasure);
974 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);
975 }
976
977 TcpTrimInWnd (Tcb, Nbuf);
978
979 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
980
981 DEBUG (
982 (EFI_D_INFO,
983 "TcpInput: connection established for TCB %p in SYN_SENT\n",
984 Tcb)
985 );
986
987 goto StepSix;
988 } else {
989 //
990 // Received a SYN segment without ACK, simultanous open.
991 //
992 TcpSetState (Tcb, TCP_SYN_RCVD);
993
994 ASSERT (Tcb->SndNxt == Tcb->Iss + 1);
995 TcpAdjustSndQue (Tcb, Tcb->SndNxt);
996
997 TcpTrimInWnd (Tcb, Nbuf);
998
999 DEBUG (
1000 (EFI_D_WARN,
1001 "TcpInput: simultaneous open for TCB %p in SYN_SENT\n",
1002 Tcb)
1003 );
1004
1005 goto StepSix;
1006 }
1007 }
1008
1009 goto DISCARD;
1010 }
1011
1012 //
1013 // Process segment in SYN_RCVD or TCP_CONNECTED states
1014 //
1015
1016 //
1017 // Clear probe timer since the RecvWindow is opened.
1018 //
1019 if (Tcb->ProbeTimerOn && (Seg->Wnd != 0)) {
1020 TcpClearTimer (Tcb, TCP_TIMER_PROBE);
1021 Tcb->ProbeTimerOn = FALSE;
1022 }
1023
1024 //
1025 // First step: Check whether SEG.SEQ is acceptable
1026 //
1027 if (TcpSeqAcceptable (Tcb, Seg) == 0) {
1028 DEBUG (
1029 (EFI_D_WARN,
1030 "TcpInput: sequence acceptance test failed for segment of TCB %p\n",
1031 Tcb)
1032 );
1033
1034 if (!TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
1035 TcpSendAck (Tcb);
1036 }
1037
1038 goto DISCARD;
1039 }
1040
1041 if ((TCP_SEQ_LT (Seg->Seq, Tcb->RcvWl2)) &&
1042 (Tcb->RcvWl2 == Seg->End) &&
1043 !TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN | TCP_FLG_FIN))
1044 {
1045
1046 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
1047 }
1048
1049 //
1050 // Second step: Check the RST
1051 //
1052 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
1053
1054 DEBUG ((EFI_D_WARN, "TcpInput: connection reset for TCB %p\n", Tcb));
1055
1056 if (Tcb->State == TCP_SYN_RCVD) {
1057
1058 SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_REFUSED);
1059
1060 //
1061 // This TCB comes from either a LISTEN TCB,
1062 // or active open TCB with simultanous open.
1063 // Do NOT signal user CONNECTION refused
1064 // if it comes from a LISTEN TCB.
1065 //
1066 } else if ((Tcb->State == TCP_ESTABLISHED) ||
1067 (Tcb->State == TCP_FIN_WAIT_1) ||
1068 (Tcb->State == TCP_FIN_WAIT_2) ||
1069 (Tcb->State == TCP_CLOSE_WAIT))
1070 {
1071
1072 SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
1073
1074 } else {
1075 }
1076
1077 goto DROP_CONNECTION;
1078 }
1079
1080 //
1081 // Trim the data and flags.
1082 //
1083 TcpTrimInWnd (Tcb, Nbuf);
1084
1085 //
1086 // Third step: Check security and precedence, Ignored
1087 //
1088
1089 //
1090 // Fourth step: Check the SYN bit.
1091 //
1092 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
1093
1094 DEBUG (
1095 (EFI_D_WARN,
1096 "TcpInput: connection reset because received extra SYN for TCB %p\n",
1097 Tcb)
1098 );
1099
1100 SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
1101 goto RESET_THEN_DROP;
1102 }
1103 //
1104 // Fifth step: Check the ACK
1105 //
1106 if (!TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
1107 DEBUG (
1108 (EFI_D_WARN,
1109 "TcpInput: segment discard because of no ACK for connected TCB %p\n",
1110 Tcb)
1111 );
1112
1113 goto DISCARD;
1114 } else {
1115 if (Tcb->IpInfo->IpVersion == IP_VERSION_6 && Tcb->Tick == 0) {
1116 Tcp6RefreshNeighbor (Tcb, Src, TCP6_KEEP_NEIGHBOR_TIME * TICKS_PER_SECOND);
1117 Tcb->Tick = TCP6_REFRESH_NEIGHBOR_TICK;
1118 }
1119 }
1120
1121 if (Tcb->State == TCP_SYN_RCVD) {
1122
1123 if (TCP_SEQ_LT (Tcb->SndUna, Seg->Ack) &&
1124 TCP_SEQ_LEQ (Seg->Ack, Tcb->SndNxt))
1125 {
1126
1127 Tcb->SndWnd = Seg->Wnd;
1128 Tcb->SndWndMax = MAX (Tcb->SndWnd, Tcb->SndWndMax);
1129 Tcb->SndWl1 = Seg->Seq;
1130 Tcb->SndWl2 = Seg->Ack;
1131 TcpSetState (Tcb, TCP_ESTABLISHED);
1132
1133 TcpClearTimer (Tcb, TCP_TIMER_CONNECT);
1134 TcpDeliverData (Tcb);
1135
1136 DEBUG (
1137 (EFI_D_INFO,
1138 "TcpInput: connection established for TCB %p in SYN_RCVD\n",
1139 Tcb)
1140 );
1141
1142 //
1143 // Continue the process as ESTABLISHED state
1144 //
1145 } else {
1146 DEBUG (
1147 (EFI_D_WARN,
1148 "TcpInput: send reset because of wrong ACK for TCB %p in SYN_RCVD\n",
1149 Tcb)
1150 );
1151
1152 goto SEND_RESET;
1153 }
1154 }
1155
1156 if (TCP_SEQ_LT (Seg->Ack, Tcb->SndUna)) {
1157
1158 DEBUG (
1159 (EFI_D_WARN,
1160 "TcpInput: ignore the out-of-data ACK for connected TCB %p\n",
1161 Tcb)
1162 );
1163
1164 goto StepSix;
1165
1166 } else if (TCP_SEQ_GT (Seg->Ack, Tcb->SndNxt)) {
1167
1168 DEBUG (
1169 (EFI_D_WARN,
1170 "TcpInput: discard segment for future ACK for connected TCB %p\n",
1171 Tcb)
1172 );
1173
1174 TcpSendAck (Tcb);
1175 goto DISCARD;
1176 }
1177
1178 //
1179 // From now on: SND.UNA <= SEG.ACK <= SND.NXT.
1180 //
1181 if (TCP_FLG_ON (Option.Flag, TCP_OPTION_RCVD_TS)) {
1182 //
1183 // update TsRecent as specified in page 16 RFC1323.
1184 // RcvWl2 equals to the variable "LastAckSent"
1185 // defined there.
1186 //
1187 if (TCP_SEQ_LEQ (Seg->Seq, Tcb->RcvWl2) &&
1188 TCP_SEQ_LT (Tcb->RcvWl2, Seg->End))
1189 {
1190
1191 Tcb->TsRecent = Option.TSVal;
1192 Tcb->TsRecentAge = mTcpTick;
1193 }
1194
1195 TcpComputeRtt (Tcb, TCP_SUB_TIME (mTcpTick, Option.TSEcr));
1196
1197 } else if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {
1198
1199 ASSERT (Tcb->CongestState == TCP_CONGEST_OPEN);
1200
1201 TcpComputeRtt (Tcb, Tcb->RttMeasure);
1202 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);
1203 }
1204
1205 if (Seg->Ack == Tcb->SndNxt) {
1206
1207 TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
1208 } else {
1209
1210 TcpSetTimer (Tcb, TCP_TIMER_REXMIT, Tcb->Rto);
1211 }
1212
1213 //
1214 // Count duplicate acks.
1215 //
1216 if ((Seg->Ack == Tcb->SndUna) &&
1217 (Tcb->SndUna != Tcb->SndNxt) &&
1218 (Seg->Wnd == Tcb->SndWnd) &&
1219 (0 == Len))
1220 {
1221
1222 Tcb->DupAck++;
1223 } else {
1224
1225 Tcb->DupAck = 0;
1226 }
1227
1228 //
1229 // Congestion avoidance, fast recovery and fast retransmission.
1230 //
1231 if (((Tcb->CongestState == TCP_CONGEST_OPEN) && (Tcb->DupAck < 3)) ||
1232 (Tcb->CongestState == TCP_CONGEST_LOSS))
1233 {
1234
1235 if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {
1236
1237 if (Tcb->CWnd < Tcb->Ssthresh) {
1238
1239 Tcb->CWnd += Tcb->SndMss;
1240 } else {
1241
1242 Tcb->CWnd += MAX (Tcb->SndMss * Tcb->SndMss / Tcb->CWnd, 1);
1243 }
1244
1245 Tcb->CWnd = MIN (Tcb->CWnd, TCP_MAX_WIN << Tcb->SndWndScale);
1246 }
1247
1248 if (Tcb->CongestState == TCP_CONGEST_LOSS) {
1249 TcpFastLossRecover (Tcb, Seg);
1250 }
1251 } else {
1252
1253 TcpFastRecover (Tcb, Seg);
1254 }
1255
1256 if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {
1257
1258 TcpAdjustSndQue (Tcb, Seg->Ack);
1259 Tcb->SndUna = Seg->Ack;
1260
1261 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_URG) &&
1262 TCP_SEQ_LT (Tcb->SndUp, Seg->Ack))
1263 {
1264
1265 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_SND_URG);
1266 }
1267 }
1268
1269 //
1270 // Update window info
1271 //
1272 if (TCP_SEQ_LT (Tcb->SndWl1, Seg->Seq) ||
1273 ((Tcb->SndWl1 == Seg->Seq) && TCP_SEQ_LEQ (Tcb->SndWl2, Seg->Ack)))
1274 {
1275
1276 Right = Seg->Ack + Seg->Wnd;
1277
1278 if (TCP_SEQ_LT (Right, Tcb->SndWl2 + Tcb->SndWnd)) {
1279
1280 if ((Tcb->SndWl1 == Seg->Seq) &&
1281 (Tcb->SndWl2 == Seg->Ack) &&
1282 (Len == 0))
1283 {
1284
1285 goto NO_UPDATE;
1286 }
1287
1288 DEBUG (
1289 (EFI_D_WARN,
1290 "TcpInput: peer shrinks the window for connected TCB %p\n",
1291 Tcb)
1292 );
1293
1294 if ((Tcb->CongestState == TCP_CONGEST_RECOVER) &&
1295 (TCP_SEQ_LT (Right, Tcb->Recover)))
1296 {
1297
1298 Tcb->Recover = Right;
1299 }
1300
1301 if ((Tcb->CongestState == TCP_CONGEST_LOSS) &&
1302 (TCP_SEQ_LT (Right, Tcb->LossRecover)))
1303 {
1304
1305 Tcb->LossRecover = Right;
1306 }
1307
1308 if (TCP_SEQ_LT (Right, Tcb->SndNxt)) {
1309
1310 Tcb->SndNxt = Right;
1311
1312 if (Right == Tcb->SndUna) {
1313
1314 TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
1315 TcpSetProbeTimer (Tcb);
1316 }
1317 }
1318 }
1319
1320 Tcb->SndWnd = Seg->Wnd;
1321 Tcb->SndWndMax = MAX (Tcb->SndWnd, Tcb->SndWndMax);
1322 Tcb->SndWl1 = Seg->Seq;
1323 Tcb->SndWl2 = Seg->Ack;
1324 }
1325
1326 NO_UPDATE:
1327
1328 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT) &&
1329 (Tcb->SndUna == Tcb->SndNxt))
1330 {
1331
1332 DEBUG (
1333 (EFI_D_INFO,
1334 "TcpInput: local FIN is ACKed by peer for connected TCB %p\n",
1335 Tcb)
1336 );
1337
1338 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED);
1339 }
1340
1341 //
1342 // Transit the state if proper.
1343 //
1344 switch (Tcb->State) {
1345 case TCP_FIN_WAIT_1:
1346
1347 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
1348
1349 TcpSetState (Tcb, TCP_FIN_WAIT_2);
1350
1351 TcpClearAllTimer (Tcb);
1352 TcpSetTimer (Tcb, TCP_TIMER_FINWAIT2, Tcb->FinWait2Timeout);
1353 }
1354
1355 case TCP_FIN_WAIT_2:
1356
1357 break;
1358
1359 case TCP_CLOSE_WAIT:
1360 break;
1361
1362 case TCP_CLOSING:
1363
1364 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
1365
1366 TcpSetState (Tcb, TCP_TIME_WAIT);
1367
1368 TcpClearAllTimer (Tcb);
1369
1370 if (Tcb->TimeWaitTimeout != 0) {
1371
1372 TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);
1373 } else {
1374
1375 DEBUG (
1376 (EFI_D_WARN,
1377 "Connection closed immediately because app disables TIME_WAIT timer for %p\n",
1378 Tcb)
1379 );
1380
1381 TcpClose (Tcb);
1382 }
1383 }
1384 break;
1385
1386 case TCP_LAST_ACK:
1387
1388 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
1389
1390 TcpSetState (Tcb, TCP_CLOSED);
1391 }
1392
1393 break;
1394
1395 case TCP_TIME_WAIT:
1396
1397 TcpSendAck (Tcb);
1398
1399 if (Tcb->TimeWaitTimeout != 0) {
1400
1401 TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);
1402 } else {
1403
1404 DEBUG (
1405 (EFI_D_WARN,
1406 "Connection closed immediately because app disables TIME_WAIT timer for %p\n",
1407 Tcb)
1408 );
1409
1410 TcpClose (Tcb);
1411 }
1412 break;
1413
1414 default:
1415 break;
1416 }
1417 //
1418 // Sixth step: Check the URG bit.update the Urg point
1419 // if in TCP_CAN_RECV, otherwise, leave the RcvUp intact.
1420 //
1421 StepSix:
1422
1423 Tcb->Idle = 0;
1424 TcpSetKeepaliveTimer (Tcb);
1425
1426 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_URG) && !TCP_FIN_RCVD (Tcb->State)) {
1427
1428 DEBUG (
1429 (EFI_D_INFO,
1430 "TcpInput: received urgent data from peer for connected TCB %p\n",
1431 Tcb)
1432 );
1433
1434 Urg = Seg->Seq + Seg->Urg;
1435
1436 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG) &&
1437 TCP_SEQ_GT (Urg, Tcb->RcvUp))
1438 {
1439
1440 Tcb->RcvUp = Urg;
1441 } else {
1442
1443 Tcb->RcvUp = Urg;
1444 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG);
1445 }
1446 }
1447 //
1448 // Seventh step: Process the segment data
1449 //
1450 if (Seg->End != Seg->Seq) {
1451
1452 if (TCP_FIN_RCVD (Tcb->State)) {
1453
1454 DEBUG (
1455 (EFI_D_WARN,
1456 "TcpInput: connection reset because data is lost for connected TCB %p\n",
1457 Tcb)
1458 );
1459
1460 goto RESET_THEN_DROP;
1461 }
1462
1463 if (TCP_LOCAL_CLOSED (Tcb->State) && (Nbuf->TotalSize != 0)) {
1464 DEBUG (
1465 (EFI_D_WARN,
1466 "TcpInput: connection reset because data is lost for connected TCB %p\n",
1467 Tcb)
1468 );
1469
1470 goto RESET_THEN_DROP;
1471 }
1472
1473 TcpQueueData (Tcb, Nbuf);
1474 if (TcpDeliverData (Tcb) == -1) {
1475 goto RESET_THEN_DROP;
1476 }
1477
1478 if (!IsListEmpty (&Tcb->RcvQue)) {
1479 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
1480 }
1481 }
1482
1483 //
1484 // Eighth step: check the FIN.
1485 // This step is moved to TcpDeliverData. FIN will be
1486 // processed in sequence there. Check the comments in
1487 // the beginning of the file header for information.
1488 //
1489
1490 //
1491 // Tcb is a new child of the listening Parent,
1492 // commit it.
1493 //
1494 if (Parent != NULL) {
1495 Tcb->Parent = Parent;
1496 TcpInsertTcb (Tcb);
1497 }
1498
1499 if ((Tcb->State != TCP_CLOSED) &&
1500 (TcpToSendData (Tcb, 0) == 0) &&
1501 (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW) || (Nbuf->TotalSize != 0)))
1502 {
1503
1504 TcpToSendAck (Tcb);
1505 }
1506
1507 NetbufFree (Nbuf);
1508 return 0;
1509
1510 RESET_THEN_DROP:
1511 TcpSendReset (Tcb, Head, Len, Dst, Src, Version);
1512
1513 DROP_CONNECTION:
1514 ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));
1515
1516 NetbufFree (Nbuf);
1517 TcpClose (Tcb);
1518
1519 return -1;
1520
1521 SEND_RESET:
1522
1523 TcpSendReset (Tcb, Head, Len, Dst, Src, Version);
1524
1525 DISCARD:
1526
1527 //
1528 // Tcb is a child of Parent, and it doesn't survive
1529 //
1530 DEBUG ((EFI_D_WARN, "TcpInput: Discard a packet\n"));
1531 NetbufFree (Nbuf);
1532
1533 if ((Parent != NULL) && (Tcb != NULL)) {
1534
1535 ASSERT (Tcb->Sk != NULL);
1536 TcpClose (Tcb);
1537 }
1538
1539 return 0;
1540 }
1541
1542 /**
1543 Process the received ICMP error messages for TCP.
1544
1545 @param[in] Nbuf The buffer that contains part of the TCP segment without an IP header
1546 truncated from the ICMP error packet.
1547 @param[in] IcmpErr The ICMP error code interpreted from an ICMP error packet.
1548 @param[in] Src Source address of the ICMP error message.
1549 @param[in] Dst Destination address of the ICMP error message.
1550 @param[in] Version IP_VERSION_4 indicates IP4 stack. IP_VERSION_6 indicates
1551 IP6 stack.
1552
1553 **/
1554 VOID
1555 TcpIcmpInput (
1556 IN NET_BUF *Nbuf,
1557 IN UINT8 IcmpErr,
1558 IN EFI_IP_ADDRESS *Src,
1559 IN EFI_IP_ADDRESS *Dst,
1560 IN UINT8 Version
1561 )
1562 {
1563 TCP_HEAD *Head;
1564 TCP_CB *Tcb;
1565 TCP_SEQNO Seq;
1566 EFI_STATUS IcmpErrStatus;
1567 BOOLEAN IcmpErrIsHard;
1568 BOOLEAN IcmpErrNotify;
1569
1570 if (Nbuf->TotalSize < sizeof (TCP_HEAD)) {
1571 goto CLEAN_EXIT;
1572 }
1573
1574 Head = (TCP_HEAD *) NetbufGetByte (Nbuf, 0, NULL);
1575 ASSERT (Head != NULL);
1576
1577 Tcb = TcpLocateTcb (
1578 Head->DstPort,
1579 Dst,
1580 Head->SrcPort,
1581 Src,
1582 Version,
1583 FALSE
1584 );
1585 if (Tcb == NULL || Tcb->State == TCP_CLOSED) {
1586
1587 goto CLEAN_EXIT;
1588 }
1589
1590 //
1591 // Validate the sequence number.
1592 //
1593 Seq = NTOHL (Head->Seq);
1594 if (!(TCP_SEQ_LEQ (Tcb->SndUna, Seq) && TCP_SEQ_LT (Seq, Tcb->SndNxt))) {
1595
1596 goto CLEAN_EXIT;
1597 }
1598
1599 IcmpErrStatus = IpIoGetIcmpErrStatus (
1600 IcmpErr,
1601 Tcb->Sk->IpVersion,
1602 &IcmpErrIsHard,
1603 &IcmpErrNotify
1604 );
1605
1606 if (IcmpErrNotify) {
1607
1608 SOCK_ERROR (Tcb->Sk, IcmpErrStatus);
1609 }
1610
1611 if (IcmpErrIsHard) {
1612
1613 TcpClose (Tcb);
1614 }
1615
1616 CLEAN_EXIT:
1617
1618 NetbufFree (Nbuf);
1619 }
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