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SecurityPkg: Add TPM PTP support in TCG2 SMM.
[mirror_edk2.git] / NetworkPkg / TcpDxe / TcpInput.c
1 /** @file
2 TCP input process routines.
3
4 Copyright (c) 2009 - 2015, 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 Len = Nbuf->TotalSize - (Head->HeadLen << 2);
752
753 if ((Head->HeadLen < 5) || (Len < 0)) {
754
755 DEBUG ((EFI_D_INFO, "TcpInput: received a malformed packet\n"));
756 goto DISCARD;
757 }
758
759 if (Version == IP_VERSION_4) {
760 Checksum = NetPseudoHeadChecksum (Src->Addr[0], Dst->Addr[0], 6, 0);
761 } else {
762 Checksum = NetIp6PseudoHeadChecksum (&Src->v6, &Dst->v6, 6, 0);
763 }
764
765 Checksum = TcpChecksum (Nbuf, Checksum);
766
767 if (Checksum != 0) {
768 DEBUG ((EFI_D_ERROR, "TcpInput: received a checksum error packet\n"));
769 goto DISCARD;
770 }
771
772 if (TCP_FLG_ON (Head->Flag, TCP_FLG_SYN)) {
773 Len++;
774 }
775
776 if (TCP_FLG_ON (Head->Flag, TCP_FLG_FIN)) {
777 Len++;
778 }
779
780 Tcb = TcpLocateTcb (
781 Head->DstPort,
782 Dst,
783 Head->SrcPort,
784 Src,
785 Version,
786 (BOOLEAN) TCP_FLG_ON (Head->Flag, TCP_FLG_SYN)
787 );
788
789 if ((Tcb == NULL) || (Tcb->State == TCP_CLOSED)) {
790 DEBUG ((EFI_D_INFO, "TcpInput: send reset because no TCB found\n"));
791
792 Tcb = NULL;
793 goto SEND_RESET;
794 }
795
796 Seg = TcpFormatNetbuf (Tcb, Nbuf);
797
798 //
799 // RFC1122 recommended reaction to illegal option
800 // (in fact, an illegal option length) is reset.
801 //
802 if (TcpParseOption (Nbuf->Tcp, &Option) == -1) {
803 DEBUG (
804 (EFI_D_ERROR,
805 "TcpInput: reset the peer because of malformed option for TCB %p\n",
806 Tcb)
807 );
808
809 goto SEND_RESET;
810 }
811
812 //
813 // From now on, the segment is headless
814 //
815 NetbufTrim (Nbuf, (Head->HeadLen << 2), NET_BUF_HEAD);
816 Nbuf->Tcp = NULL;
817
818 //
819 // Process the segment in LISTEN state.
820 //
821 if (Tcb->State == TCP_LISTEN) {
822 //
823 // First step: Check RST
824 //
825 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
826 DEBUG (
827 (EFI_D_WARN,
828 "TcpInput: discard a reset segment for TCB %p in listening\n",
829 Tcb)
830 );
831
832 goto DISCARD;
833 }
834
835 //
836 // Second step: Check ACK.
837 // Any ACK sent to TCP in LISTEN is reseted.
838 //
839 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
840 DEBUG (
841 (EFI_D_WARN,
842 "TcpInput: send reset because of segment with ACK for TCB %p in listening\n",
843 Tcb)
844 );
845
846 goto SEND_RESET;
847 }
848
849 //
850 // Third step: Check SYN
851 //
852 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
853 //
854 // create a child TCB to handle the data
855 //
856 Parent = Tcb;
857
858 Tcb = TcpCloneTcb (Parent);
859 if (Tcb == NULL) {
860 DEBUG (
861 (EFI_D_ERROR,
862 "TcpInput: discard a segment because failed to clone a child for TCB %p\n",
863 Tcb)
864 );
865
866 goto DISCARD;
867 }
868
869 DEBUG (
870 (EFI_D_INFO,
871 "TcpInput: create a child for TCB %p in listening\n",
872 Tcb)
873 );
874
875 //
876 // init the TCB structure
877 //
878 IP6_COPY_ADDRESS (&Tcb->LocalEnd.Ip, Dst);
879 IP6_COPY_ADDRESS (&Tcb->RemoteEnd.Ip, Src);
880 Tcb->LocalEnd.Port = Head->DstPort;
881 Tcb->RemoteEnd.Port = Head->SrcPort;
882
883 TcpInitTcbLocal (Tcb);
884 TcpInitTcbPeer (Tcb, Seg, &Option);
885
886 TcpSetState (Tcb, TCP_SYN_RCVD);
887 TcpSetTimer (Tcb, TCP_TIMER_CONNECT, Tcb->ConnectTimeout);
888 TcpTrimInWnd (Tcb, Nbuf);
889
890 goto StepSix;
891 }
892
893 goto DISCARD;
894
895 } else if (Tcb->State == TCP_SYN_SENT) {
896 //
897 // First step: Check ACK bit
898 //
899 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK) && (Seg->Ack != Tcb->Iss + 1)) {
900
901 DEBUG (
902 (EFI_D_WARN,
903 "TcpInput: send reset because of wrong ACK received for TCB %p in SYN_SENT\n",
904 Tcb)
905 );
906
907 goto SEND_RESET;
908 }
909
910 //
911 // Second step: Check RST bit
912 //
913 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
914
915 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
916
917 DEBUG (
918 (EFI_D_WARN,
919 "TcpInput: connection reset by peer for TCB %p in SYN_SENT\n",
920 Tcb)
921 );
922
923 SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
924 goto DROP_CONNECTION;
925 } else {
926
927 DEBUG (
928 (EFI_D_WARN,
929 "TcpInput: discard a reset segment because of no ACK for TCB %p in SYN_SENT\n",
930 Tcb)
931 );
932
933 goto DISCARD;
934 }
935 }
936
937 //
938 // Third step: Check security and precedence. Skipped
939 //
940
941 //
942 // Fourth step: Check SYN. Pay attention to simultaneous open
943 //
944 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
945
946 TcpInitTcbPeer (Tcb, Seg, &Option);
947
948 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
949
950 Tcb->SndUna = Seg->Ack;
951 }
952
953 TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
954
955 if (TCP_SEQ_GT (Tcb->SndUna, Tcb->Iss)) {
956
957 TcpSetState (Tcb, TCP_ESTABLISHED);
958
959 TcpClearTimer (Tcb, TCP_TIMER_CONNECT);
960 TcpDeliverData (Tcb);
961
962 if ((Tcb->CongestState == TCP_CONGEST_OPEN) &&
963 TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON))
964 {
965
966 TcpComputeRtt (Tcb, Tcb->RttMeasure);
967 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);
968 }
969
970 TcpTrimInWnd (Tcb, Nbuf);
971
972 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
973
974 DEBUG (
975 (EFI_D_INFO,
976 "TcpInput: connection established for TCB %p in SYN_SENT\n",
977 Tcb)
978 );
979
980 goto StepSix;
981 } else {
982 //
983 // Received a SYN segment without ACK, simultanous open.
984 //
985 TcpSetState (Tcb, TCP_SYN_RCVD);
986
987 ASSERT (Tcb->SndNxt == Tcb->Iss + 1);
988 TcpAdjustSndQue (Tcb, Tcb->SndNxt);
989
990 TcpTrimInWnd (Tcb, Nbuf);
991
992 DEBUG (
993 (EFI_D_WARN,
994 "TcpInput: simultaneous open for TCB %p in SYN_SENT\n",
995 Tcb)
996 );
997
998 goto StepSix;
999 }
1000 }
1001
1002 goto DISCARD;
1003 }
1004
1005 //
1006 // Process segment in SYN_RCVD or TCP_CONNECTED states
1007 //
1008
1009 //
1010 // Clear probe timer since the RecvWindow is opened.
1011 //
1012 if (Tcb->ProbeTimerOn && (Seg->Wnd != 0)) {
1013 TcpClearTimer (Tcb, TCP_TIMER_PROBE);
1014 Tcb->ProbeTimerOn = FALSE;
1015 }
1016
1017 //
1018 // First step: Check whether SEG.SEQ is acceptable
1019 //
1020 if (TcpSeqAcceptable (Tcb, Seg) == 0) {
1021 DEBUG (
1022 (EFI_D_WARN,
1023 "TcpInput: sequence acceptance test failed for segment of TCB %p\n",
1024 Tcb)
1025 );
1026
1027 if (!TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
1028 TcpSendAck (Tcb);
1029 }
1030
1031 goto DISCARD;
1032 }
1033
1034 if ((TCP_SEQ_LT (Seg->Seq, Tcb->RcvWl2)) &&
1035 (Tcb->RcvWl2 == Seg->End) &&
1036 !TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN | TCP_FLG_FIN))
1037 {
1038
1039 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
1040 }
1041
1042 //
1043 // Second step: Check the RST
1044 //
1045 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
1046
1047 DEBUG ((EFI_D_WARN, "TcpInput: connection reset for TCB %p\n", Tcb));
1048
1049 if (Tcb->State == TCP_SYN_RCVD) {
1050
1051 SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_REFUSED);
1052
1053 //
1054 // This TCB comes from either a LISTEN TCB,
1055 // or active open TCB with simultanous open.
1056 // Do NOT signal user CONNECTION refused
1057 // if it comes from a LISTEN TCB.
1058 //
1059 } else if ((Tcb->State == TCP_ESTABLISHED) ||
1060 (Tcb->State == TCP_FIN_WAIT_1) ||
1061 (Tcb->State == TCP_FIN_WAIT_2) ||
1062 (Tcb->State == TCP_CLOSE_WAIT))
1063 {
1064
1065 SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
1066
1067 } else {
1068 }
1069
1070 goto DROP_CONNECTION;
1071 }
1072
1073 //
1074 // Trim the data and flags.
1075 //
1076 TcpTrimInWnd (Tcb, Nbuf);
1077
1078 //
1079 // Third step: Check security and precedence, Ignored
1080 //
1081
1082 //
1083 // Fourth step: Check the SYN bit.
1084 //
1085 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
1086
1087 DEBUG (
1088 (EFI_D_WARN,
1089 "TcpInput: connection reset because received extra SYN for TCB %p\n",
1090 Tcb)
1091 );
1092
1093 SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
1094 goto RESET_THEN_DROP;
1095 }
1096 //
1097 // Fifth step: Check the ACK
1098 //
1099 if (!TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
1100 DEBUG (
1101 (EFI_D_WARN,
1102 "TcpInput: segment discard because of no ACK for connected TCB %p\n",
1103 Tcb)
1104 );
1105
1106 goto DISCARD;
1107 } else {
1108 if (Tcb->IpInfo->IpVersion == IP_VERSION_6 && Tcb->Tick == 0) {
1109 Tcp6RefreshNeighbor (Tcb, Src, TCP6_KEEP_NEIGHBOR_TIME * TICKS_PER_SECOND);
1110 Tcb->Tick = TCP6_REFRESH_NEIGHBOR_TICK;
1111 }
1112 }
1113
1114 if (Tcb->State == TCP_SYN_RCVD) {
1115
1116 if (TCP_SEQ_LT (Tcb->SndUna, Seg->Ack) &&
1117 TCP_SEQ_LEQ (Seg->Ack, Tcb->SndNxt))
1118 {
1119
1120 Tcb->SndWnd = Seg->Wnd;
1121 Tcb->SndWndMax = MAX (Tcb->SndWnd, Tcb->SndWndMax);
1122 Tcb->SndWl1 = Seg->Seq;
1123 Tcb->SndWl2 = Seg->Ack;
1124 TcpSetState (Tcb, TCP_ESTABLISHED);
1125
1126 TcpClearTimer (Tcb, TCP_TIMER_CONNECT);
1127 TcpDeliverData (Tcb);
1128
1129 DEBUG (
1130 (EFI_D_INFO,
1131 "TcpInput: connection established for TCB %p in SYN_RCVD\n",
1132 Tcb)
1133 );
1134
1135 //
1136 // Continue the process as ESTABLISHED state
1137 //
1138 } else {
1139 DEBUG (
1140 (EFI_D_WARN,
1141 "TcpInput: send reset because of wrong ACK for TCB %p in SYN_RCVD\n",
1142 Tcb)
1143 );
1144
1145 goto SEND_RESET;
1146 }
1147 }
1148
1149 if (TCP_SEQ_LT (Seg->Ack, Tcb->SndUna)) {
1150
1151 DEBUG (
1152 (EFI_D_WARN,
1153 "TcpInput: ignore the out-of-data ACK for connected TCB %p\n",
1154 Tcb)
1155 );
1156
1157 goto StepSix;
1158
1159 } else if (TCP_SEQ_GT (Seg->Ack, Tcb->SndNxt)) {
1160
1161 DEBUG (
1162 (EFI_D_WARN,
1163 "TcpInput: discard segment for future ACK for connected TCB %p\n",
1164 Tcb)
1165 );
1166
1167 TcpSendAck (Tcb);
1168 goto DISCARD;
1169 }
1170
1171 //
1172 // From now on: SND.UNA <= SEG.ACK <= SND.NXT.
1173 //
1174 if (TCP_FLG_ON (Option.Flag, TCP_OPTION_RCVD_TS)) {
1175 //
1176 // update TsRecent as specified in page 16 RFC1323.
1177 // RcvWl2 equals to the variable "LastAckSent"
1178 // defined there.
1179 //
1180 if (TCP_SEQ_LEQ (Seg->Seq, Tcb->RcvWl2) &&
1181 TCP_SEQ_LT (Tcb->RcvWl2, Seg->End))
1182 {
1183
1184 Tcb->TsRecent = Option.TSVal;
1185 Tcb->TsRecentAge = mTcpTick;
1186 }
1187
1188 TcpComputeRtt (Tcb, TCP_SUB_TIME (mTcpTick, Option.TSEcr));
1189
1190 } else if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {
1191
1192 ASSERT (Tcb->CongestState == TCP_CONGEST_OPEN);
1193
1194 TcpComputeRtt (Tcb, Tcb->RttMeasure);
1195 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);
1196 }
1197
1198 if (Seg->Ack == Tcb->SndNxt) {
1199
1200 TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
1201 } else {
1202
1203 TcpSetTimer (Tcb, TCP_TIMER_REXMIT, Tcb->Rto);
1204 }
1205
1206 //
1207 // Count duplicate acks.
1208 //
1209 if ((Seg->Ack == Tcb->SndUna) &&
1210 (Tcb->SndUna != Tcb->SndNxt) &&
1211 (Seg->Wnd == Tcb->SndWnd) &&
1212 (0 == Len))
1213 {
1214
1215 Tcb->DupAck++;
1216 } else {
1217
1218 Tcb->DupAck = 0;
1219 }
1220
1221 //
1222 // Congestion avoidance, fast recovery and fast retransmission.
1223 //
1224 if (((Tcb->CongestState == TCP_CONGEST_OPEN) && (Tcb->DupAck < 3)) ||
1225 (Tcb->CongestState == TCP_CONGEST_LOSS))
1226 {
1227
1228 if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {
1229
1230 if (Tcb->CWnd < Tcb->Ssthresh) {
1231
1232 Tcb->CWnd += Tcb->SndMss;
1233 } else {
1234
1235 Tcb->CWnd += MAX (Tcb->SndMss * Tcb->SndMss / Tcb->CWnd, 1);
1236 }
1237
1238 Tcb->CWnd = MIN (Tcb->CWnd, TCP_MAX_WIN << Tcb->SndWndScale);
1239 }
1240
1241 if (Tcb->CongestState == TCP_CONGEST_LOSS) {
1242 TcpFastLossRecover (Tcb, Seg);
1243 }
1244 } else {
1245
1246 TcpFastRecover (Tcb, Seg);
1247 }
1248
1249 if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {
1250
1251 TcpAdjustSndQue (Tcb, Seg->Ack);
1252 Tcb->SndUna = Seg->Ack;
1253
1254 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_URG) &&
1255 TCP_SEQ_LT (Tcb->SndUp, Seg->Ack))
1256 {
1257
1258 TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_SND_URG);
1259 }
1260 }
1261
1262 //
1263 // Update window info
1264 //
1265 if (TCP_SEQ_LT (Tcb->SndWl1, Seg->Seq) ||
1266 ((Tcb->SndWl1 == Seg->Seq) && TCP_SEQ_LEQ (Tcb->SndWl2, Seg->Ack)))
1267 {
1268
1269 Right = Seg->Ack + Seg->Wnd;
1270
1271 if (TCP_SEQ_LT (Right, Tcb->SndWl2 + Tcb->SndWnd)) {
1272
1273 if ((Tcb->SndWl1 == Seg->Seq) &&
1274 (Tcb->SndWl2 == Seg->Ack) &&
1275 (Len == 0))
1276 {
1277
1278 goto NO_UPDATE;
1279 }
1280
1281 DEBUG (
1282 (EFI_D_WARN,
1283 "TcpInput: peer shrinks the window for connected TCB %p\n",
1284 Tcb)
1285 );
1286
1287 if ((Tcb->CongestState == TCP_CONGEST_RECOVER) &&
1288 (TCP_SEQ_LT (Right, Tcb->Recover)))
1289 {
1290
1291 Tcb->Recover = Right;
1292 }
1293
1294 if ((Tcb->CongestState == TCP_CONGEST_LOSS) &&
1295 (TCP_SEQ_LT (Right, Tcb->LossRecover)))
1296 {
1297
1298 Tcb->LossRecover = Right;
1299 }
1300
1301 if (TCP_SEQ_LT (Right, Tcb->SndNxt)) {
1302
1303 Tcb->SndNxt = Right;
1304
1305 if (Right == Tcb->SndUna) {
1306
1307 TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
1308 TcpSetProbeTimer (Tcb);
1309 }
1310 }
1311 }
1312
1313 Tcb->SndWnd = Seg->Wnd;
1314 Tcb->SndWndMax = MAX (Tcb->SndWnd, Tcb->SndWndMax);
1315 Tcb->SndWl1 = Seg->Seq;
1316 Tcb->SndWl2 = Seg->Ack;
1317 }
1318
1319 NO_UPDATE:
1320
1321 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT) &&
1322 (Tcb->SndUna == Tcb->SndNxt))
1323 {
1324
1325 DEBUG (
1326 (EFI_D_INFO,
1327 "TcpInput: local FIN is ACKed by peer for connected TCB %p\n",
1328 Tcb)
1329 );
1330
1331 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED);
1332 }
1333
1334 //
1335 // Transit the state if proper.
1336 //
1337 switch (Tcb->State) {
1338 case TCP_FIN_WAIT_1:
1339
1340 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
1341
1342 TcpSetState (Tcb, TCP_FIN_WAIT_2);
1343
1344 TcpClearAllTimer (Tcb);
1345 TcpSetTimer (Tcb, TCP_TIMER_FINWAIT2, Tcb->FinWait2Timeout);
1346 }
1347
1348 case TCP_FIN_WAIT_2:
1349
1350 break;
1351
1352 case TCP_CLOSE_WAIT:
1353 break;
1354
1355 case TCP_CLOSING:
1356
1357 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
1358
1359 TcpSetState (Tcb, TCP_TIME_WAIT);
1360
1361 TcpClearAllTimer (Tcb);
1362
1363 if (Tcb->TimeWaitTimeout != 0) {
1364
1365 TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);
1366 } else {
1367
1368 DEBUG (
1369 (EFI_D_WARN,
1370 "Connection closed immediately because app disables TIME_WAIT timer for %p\n",
1371 Tcb)
1372 );
1373
1374 TcpClose (Tcb);
1375 }
1376 }
1377 break;
1378
1379 case TCP_LAST_ACK:
1380
1381 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
1382
1383 TcpSetState (Tcb, TCP_CLOSED);
1384 }
1385
1386 break;
1387
1388 case TCP_TIME_WAIT:
1389
1390 TcpSendAck (Tcb);
1391
1392 if (Tcb->TimeWaitTimeout != 0) {
1393
1394 TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);
1395 } else {
1396
1397 DEBUG (
1398 (EFI_D_WARN,
1399 "Connection closed immediately because app disables TIME_WAIT timer for %p\n",
1400 Tcb)
1401 );
1402
1403 TcpClose (Tcb);
1404 }
1405 break;
1406
1407 default:
1408 break;
1409 }
1410 //
1411 // Sixth step: Check the URG bit.update the Urg point
1412 // if in TCP_CAN_RECV, otherwise, leave the RcvUp intact.
1413 //
1414 StepSix:
1415
1416 Tcb->Idle = 0;
1417 TcpSetKeepaliveTimer (Tcb);
1418
1419 if (TCP_FLG_ON (Seg->Flag, TCP_FLG_URG) && !TCP_FIN_RCVD (Tcb->State)) {
1420
1421 DEBUG (
1422 (EFI_D_INFO,
1423 "TcpInput: received urgent data from peer for connected TCB %p\n",
1424 Tcb)
1425 );
1426
1427 Urg = Seg->Seq + Seg->Urg;
1428
1429 if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG) &&
1430 TCP_SEQ_GT (Urg, Tcb->RcvUp))
1431 {
1432
1433 Tcb->RcvUp = Urg;
1434 } else {
1435
1436 Tcb->RcvUp = Urg;
1437 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG);
1438 }
1439 }
1440 //
1441 // Seventh step: Process the segment data
1442 //
1443 if (Seg->End != Seg->Seq) {
1444
1445 if (TCP_FIN_RCVD (Tcb->State)) {
1446
1447 DEBUG (
1448 (EFI_D_WARN,
1449 "TcpInput: connection reset because data is lost for connected TCB %p\n",
1450 Tcb)
1451 );
1452
1453 goto RESET_THEN_DROP;
1454 }
1455
1456 if (TCP_LOCAL_CLOSED (Tcb->State) && (Nbuf->TotalSize != 0)) {
1457 DEBUG (
1458 (EFI_D_WARN,
1459 "TcpInput: connection reset because data is lost for connected TCB %p\n",
1460 Tcb)
1461 );
1462
1463 goto RESET_THEN_DROP;
1464 }
1465
1466 TcpQueueData (Tcb, Nbuf);
1467 if (TcpDeliverData (Tcb) == -1) {
1468 goto RESET_THEN_DROP;
1469 }
1470
1471 if (!IsListEmpty (&Tcb->RcvQue)) {
1472 TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
1473 }
1474 }
1475
1476 //
1477 // Eighth step: check the FIN.
1478 // This step is moved to TcpDeliverData. FIN will be
1479 // processed in sequence there. Check the comments in
1480 // the beginning of the file header for information.
1481 //
1482
1483 //
1484 // Tcb is a new child of the listening Parent,
1485 // commit it.
1486 //
1487 if (Parent != NULL) {
1488 Tcb->Parent = Parent;
1489 TcpInsertTcb (Tcb);
1490 }
1491
1492 if ((Tcb->State != TCP_CLOSED) &&
1493 (TcpToSendData (Tcb, 0) == 0) &&
1494 (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW) || (Nbuf->TotalSize != 0)))
1495 {
1496
1497 TcpToSendAck (Tcb);
1498 }
1499
1500 NetbufFree (Nbuf);
1501 return 0;
1502
1503 RESET_THEN_DROP:
1504 TcpSendReset (Tcb, Head, Len, Dst, Src, Version);
1505
1506 DROP_CONNECTION:
1507 ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));
1508
1509 NetbufFree (Nbuf);
1510 TcpClose (Tcb);
1511
1512 return -1;
1513
1514 SEND_RESET:
1515
1516 TcpSendReset (Tcb, Head, Len, Dst, Src, Version);
1517
1518 DISCARD:
1519
1520 //
1521 // Tcb is a child of Parent, and it doesn't survive
1522 //
1523 DEBUG ((EFI_D_WARN, "TcpInput: Discard a packet\n"));
1524 NetbufFree (Nbuf);
1525
1526 if ((Parent != NULL) && (Tcb != NULL)) {
1527
1528 ASSERT (Tcb->Sk != NULL);
1529 TcpClose (Tcb);
1530 }
1531
1532 return 0;
1533 }
1534
1535 /**
1536 Process the received ICMP error messages for TCP.
1537
1538 @param[in] Nbuf The buffer that contains part of the TCP segment without an IP header
1539 truncated from the ICMP error packet.
1540 @param[in] IcmpErr The ICMP error code interpreted from an ICMP error packet.
1541 @param[in] Src Source address of the ICMP error message.
1542 @param[in] Dst Destination address of the ICMP error message.
1543 @param[in] Version IP_VERSION_4 indicates IP4 stack. IP_VERSION_6 indicates
1544 IP6 stack.
1545
1546 **/
1547 VOID
1548 TcpIcmpInput (
1549 IN NET_BUF *Nbuf,
1550 IN UINT8 IcmpErr,
1551 IN EFI_IP_ADDRESS *Src,
1552 IN EFI_IP_ADDRESS *Dst,
1553 IN UINT8 Version
1554 )
1555 {
1556 TCP_HEAD *Head;
1557 TCP_CB *Tcb;
1558 TCP_SEQNO Seq;
1559 EFI_STATUS IcmpErrStatus;
1560 BOOLEAN IcmpErrIsHard;
1561 BOOLEAN IcmpErrNotify;
1562
1563 Head = (TCP_HEAD *) NetbufGetByte (Nbuf, 0, NULL);
1564 ASSERT (Head != NULL);
1565
1566 Tcb = TcpLocateTcb (
1567 Head->DstPort,
1568 Dst,
1569 Head->SrcPort,
1570 Src,
1571 Version,
1572 FALSE
1573 );
1574 if (Tcb == NULL || Tcb->State == TCP_CLOSED) {
1575
1576 goto CLEAN_EXIT;
1577 }
1578
1579 //
1580 // Validate the sequence number.
1581 //
1582 Seq = NTOHL (Head->Seq);
1583 if (!(TCP_SEQ_LEQ (Tcb->SndUna, Seq) && TCP_SEQ_LT (Seq, Tcb->SndNxt))) {
1584
1585 goto CLEAN_EXIT;
1586 }
1587
1588 IcmpErrStatus = IpIoGetIcmpErrStatus (
1589 IcmpErr,
1590 Tcb->Sk->IpVersion,
1591 &IcmpErrIsHard,
1592 &IcmpErrNotify
1593 );
1594
1595 if (IcmpErrNotify) {
1596
1597 SOCK_ERROR (Tcb->Sk, IcmpErrStatus);
1598 }
1599
1600 if (IcmpErrIsHard) {
1601
1602 TcpClose (Tcb);
1603 }
1604
1605 CLEAN_EXIT:
1606
1607 NetbufFree (Nbuf);
1608 }
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