diff options
Diffstat (limited to 'NetworkPkg/TcpDxe/TcpInput.c')
| -rw-r--r-- | NetworkPkg/TcpDxe/TcpInput.c | 1592 |
1 files changed, 1592 insertions, 0 deletions
diff --git a/NetworkPkg/TcpDxe/TcpInput.c b/NetworkPkg/TcpDxe/TcpInput.c new file mode 100644 index 0000000000..e63469adb9 --- /dev/null +++ b/NetworkPkg/TcpDxe/TcpInput.c @@ -0,0 +1,1592 @@ +/** @file
+ TCP input process routines.
+
+ Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
+
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include "TcpMain.h"
+
+/**
+ Check whether the sequence number of the incoming segment is acceptable.
+
+ @param[in] Tcb Pointer to the TCP_CB of this TCP instance.
+ @param[in] Seg Pointer to the incoming segment.
+
+ @retval 1 The sequence number is acceptable.
+ @retval 0 The sequence number is not acceptable.
+
+**/
+INTN
+TcpSeqAcceptable (
+ IN TCP_CB *Tcb,
+ IN TCP_SEG *Seg
+ )
+{
+ return (TCP_SEQ_LEQ (Tcb->RcvWl2, Seg->End) &&
+ TCP_SEQ_LT (Seg->Seq, Tcb->RcvWl2 + Tcb->RcvWnd));
+}
+
+/**
+ NewReno fast recovery defined in RFC3782.
+
+ @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
+ @param[in] Seg Segment that triggers the fast recovery.
+
+**/
+VOID
+TcpFastRecover (
+ IN OUT TCP_CB *Tcb,
+ IN TCP_SEG *Seg
+ )
+{
+ UINT32 FlightSize;
+ UINT32 Acked;
+
+ //
+ // Step 1: Three duplicate ACKs and not in fast recovery
+ //
+ if (Tcb->CongestState != TCP_CONGEST_RECOVER) {
+
+ //
+ // Step 1A: Invoking fast retransmission.
+ //
+ FlightSize = TCP_SUB_SEQ (Tcb->SndNxt, Tcb->SndUna);
+
+ Tcb->Ssthresh = MAX (FlightSize >> 1, (UINT32) (2 * Tcb->SndMss));
+ Tcb->Recover = Tcb->SndNxt;
+
+ Tcb->CongestState = TCP_CONGEST_RECOVER;
+ TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);
+
+ //
+ // Step 2: Entering fast retransmission
+ //
+ TcpRetransmit (Tcb, Tcb->SndUna);
+ Tcb->CWnd = Tcb->Ssthresh + 3 * Tcb->SndMss;
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpFastRecover: enter fast retransmission for TCB %p, recover point is %d\n",
+ Tcb,
+ Tcb->Recover)
+ );
+ return;
+ }
+
+ //
+ // During fast recovery, execute Step 3, 4, 5 of RFC3782
+ //
+ if (Seg->Ack == Tcb->SndUna) {
+
+ //
+ // Step 3: Fast Recovery,
+ // If this is a duplicated ACK, increse Cwnd by SMSS.
+ //
+
+ // Step 4 is skipped here only to be executed later
+ // by TcpToSendData
+ //
+ Tcb->CWnd += Tcb->SndMss;
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpFastRecover: received another duplicated ACK (%d) for TCB %p\n",
+ Seg->Ack,
+ Tcb)
+ );
+
+ } else {
+
+ //
+ // New data is ACKed, check whether it is a
+ // full ACK or partial ACK
+ //
+ if (TCP_SEQ_GEQ (Seg->Ack, Tcb->Recover)) {
+
+ //
+ // Step 5 - Full ACK:
+ // deflate the congestion window, and exit fast recovery
+ //
+ FlightSize = TCP_SUB_SEQ (Tcb->SndNxt, Tcb->SndUna);
+
+ Tcb->CWnd = MIN (Tcb->Ssthresh, FlightSize + Tcb->SndMss);
+
+ Tcb->CongestState = TCP_CONGEST_OPEN;
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpFastRecover: received a full ACK(%d) for TCB %p, exit fast recovery\n",
+ Seg->Ack,
+ Tcb)
+ );
+
+ } else {
+
+ //
+ // Step 5 - Partial ACK:
+ // fast retransmit the first unacknowledge field
+ // , then deflate the CWnd
+ //
+ TcpRetransmit (Tcb, Seg->Ack);
+ Acked = TCP_SUB_SEQ (Seg->Ack, Tcb->SndUna);
+
+ //
+ // Deflate the CWnd by the amount of new data
+ // ACKed by SEG.ACK. If more than one SMSS data
+ // is ACKed, add back SMSS byte to CWnd after
+ //
+ if (Acked >= Tcb->SndMss) {
+ Acked -= Tcb->SndMss;
+
+ }
+
+ Tcb->CWnd -= Acked;
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpFastRecover: received a partial ACK(%d) for TCB %p\n",
+ Seg->Ack,
+ Tcb)
+ );
+
+ }
+ }
+}
+
+/**
+ NewReno fast loss recovery defined in RFC3792.
+
+ @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
+ @param[in] Seg Segment that triggers the fast loss recovery.
+
+**/
+VOID
+TcpFastLossRecover (
+ IN OUT TCP_CB *Tcb,
+ IN TCP_SEG *Seg
+ )
+{
+ if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {
+
+ //
+ // New data is ACKed, check whether it is a
+ // full ACK or partial ACK
+ //
+ if (TCP_SEQ_GEQ (Seg->Ack, Tcb->LossRecover)) {
+
+ //
+ // Full ACK: exit the loss recovery.
+ //
+ Tcb->LossTimes = 0;
+ Tcb->CongestState = TCP_CONGEST_OPEN;
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpFastLossRecover: received a full ACK(%d) for TCB %p\n",
+ Seg->Ack,
+ Tcb)
+ );
+
+ } else {
+
+ //
+ // Partial ACK:
+ // fast retransmit the first unacknowledge field.
+ //
+ TcpRetransmit (Tcb, Seg->Ack);
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpFastLossRecover: received a partial ACK(%d) for TCB %p\n",
+ Seg->Ack,
+ Tcb)
+ );
+ }
+ }
+}
+
+/**
+ Compute the RTT as specified in RFC2988.
+
+ @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
+ @param[in] Measure Currently measured RTT in heartbeats.
+
+**/
+VOID
+TcpComputeRtt (
+ IN OUT TCP_CB *Tcb,
+ IN UINT32 Measure
+ )
+{
+ INT32 Var;
+
+ //
+ // Step 2.3: Compute the RTO for subsequent RTT measurement.
+ //
+ if (Tcb->SRtt != 0) {
+
+ Var = Tcb->SRtt - (Measure << TCP_RTT_SHIFT);
+
+ if (Var < 0) {
+ Var = -Var;
+ }
+
+ Tcb->RttVar = (3 * Tcb->RttVar + Var) >> 2;
+ Tcb->SRtt = 7 * (Tcb->SRtt >> 3) + Measure;
+
+ } else {
+ //
+ // Step 2.2: compute the first RTT measure
+ //
+ Tcb->SRtt = Measure << TCP_RTT_SHIFT;
+ Tcb->RttVar = Measure << (TCP_RTT_SHIFT - 1);
+ }
+
+ Tcb->Rto = (Tcb->SRtt + MAX (8, 4 * Tcb->RttVar)) >> TCP_RTT_SHIFT;
+
+ //
+ // Step 2.4: Limit the RTO to at least 1 second
+ // Step 2.5: Limit the RTO to a maxium value that
+ // is at least 60 second
+ //
+ if (Tcb->Rto < TCP_RTO_MIN) {
+ Tcb->Rto = TCP_RTO_MIN;
+
+ } else if (Tcb->Rto > TCP_RTO_MAX) {
+ Tcb->Rto = TCP_RTO_MAX;
+
+ }
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpComputeRtt: new RTT for TCB %p computed SRTT: %d RTTVAR: %d RTO: %d\n",
+ Tcb,
+ Tcb->SRtt,
+ Tcb->RttVar,
+ Tcb->Rto)
+ );
+
+}
+
+/**
+ Trim the data; SYN and FIN to fit into the window defined by Left and Right.
+
+ @param[in] Nbuf The buffer that contains a received TCP segment without an IP header.
+ @param[in] Left The sequence number of the window's left edge.
+ @param[in] Right The sequence number of the window's right edge.
+
+**/
+VOID
+TcpTrimSegment (
+ IN NET_BUF *Nbuf,
+ IN TCP_SEQNO Left,
+ IN TCP_SEQNO Right
+ )
+{
+ TCP_SEG *Seg;
+ TCP_SEQNO Urg;
+ UINT32 Drop;
+
+ Seg = TCPSEG_NETBUF (Nbuf);
+
+ //
+ // If the segment is completely out of window,
+ // truncate every thing, include SYN and FIN.
+ //
+ if (TCP_SEQ_LEQ (Seg->End, Left) || TCP_SEQ_LEQ (Right, Seg->Seq)) {
+
+ TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_SYN);
+ TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_FIN);
+
+ Seg->Seq = Seg->End;
+ NetbufTrim (Nbuf, Nbuf->TotalSize, NET_BUF_HEAD);
+ return;
+ }
+
+ //
+ // Adjust the buffer header
+ //
+ if (TCP_SEQ_LT (Seg->Seq, Left)) {
+
+ Drop = TCP_SUB_SEQ (Left, Seg->Seq);
+ Urg = Seg->Seq + Seg->Urg;
+ Seg->Seq = Left;
+
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
+ TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_SYN);
+ Drop--;
+ }
+
+ //
+ // Adjust the urgent point
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_URG)) {
+
+ if (TCP_SEQ_LT (Urg, Seg->Seq)) {
+
+ TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_URG);
+ } else {
+ Seg->Urg = (UINT16) TCP_SUB_SEQ (Urg, Seg->Seq);
+ }
+ }
+
+ if (Drop != 0) {
+ NetbufTrim (Nbuf, Drop, NET_BUF_HEAD);
+ }
+ }
+
+ //
+ // Adjust the buffer tail
+ //
+ if (TCP_SEQ_GT (Seg->End, Right)) {
+
+ Drop = TCP_SUB_SEQ (Seg->End, Right);
+ Seg->End = Right;
+
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {
+ TCP_CLEAR_FLG (Seg->Flag, TCP_FLG_FIN);
+ Drop--;
+ }
+
+ if (Drop != 0) {
+ NetbufTrim (Nbuf, Drop, NET_BUF_TAIL);
+ }
+ }
+
+ ASSERT (TcpVerifySegment (Nbuf) != 0);
+}
+
+/**
+ Trim off the data outside the tcb's receive window.
+
+ @param[in] Tcb Pointer to the TCP_CB of this TCP instance.
+ @param[in] Nbuf Pointer to the NET_BUF containing the received tcp segment.
+
+**/
+VOID
+TcpTrimInWnd (
+ IN TCP_CB *Tcb,
+ IN NET_BUF *Nbuf
+ )
+{
+ TcpTrimSegment (Nbuf, Tcb->RcvNxt, Tcb->RcvWl2 + Tcb->RcvWnd);
+}
+
+/**
+ Process the data and FIN flag, and check whether to deliver
+ data to the socket layer.
+
+ @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
+
+ @retval 0 No error occurred to deliver data.
+ @retval -1 An error condition occurred. The proper response is to reset the
+ connection.
+
+**/
+INTN
+TcpDeliverData (
+ IN OUT TCP_CB *Tcb
+ )
+{
+ LIST_ENTRY *Entry;
+ NET_BUF *Nbuf;
+ TCP_SEQNO Seq;
+ TCP_SEG *Seg;
+ UINT32 Urgent;
+
+ ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));
+
+ //
+ // make sure there is some data queued,
+ // and TCP is in a proper state
+ //
+ if (IsListEmpty (&Tcb->RcvQue) || !TCP_CONNECTED (Tcb->State)) {
+
+ return 0;
+ }
+
+ //
+ // Deliver data to the socket layer
+ //
+ Entry = Tcb->RcvQue.ForwardLink;
+ Seq = Tcb->RcvNxt;
+
+ while (Entry != &Tcb->RcvQue) {
+ Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);
+ Seg = TCPSEG_NETBUF (Nbuf);
+
+ ASSERT (TcpVerifySegment (Nbuf) != 0);
+ ASSERT (Nbuf->Tcp == NULL);
+
+ if (TCP_SEQ_GT (Seg->Seq, Seq)) {
+ break;
+ }
+
+ Entry = Entry->ForwardLink;
+ Seq = Seg->End;
+ Tcb->RcvNxt = Seq;
+
+ RemoveEntryList (&Nbuf->List);
+
+ //
+ // RFC793 Eighth step: process FIN in sequence
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_FIN)) {
+
+ //
+ // The peer sends to us junky data after FIN,
+ // reset the connection.
+ //
+ if (!IsListEmpty (&Tcb->RcvQue)) {
+ DEBUG (
+ (EFI_D_ERROR,
+ "TcpDeliverData: data received after FIN from peer of TCB %p, reset connection\n",
+ Tcb)
+ );
+
+ NetbufFree (Nbuf);
+ return -1;
+ }
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpDeliverData: processing FIN from peer of TCB %p\n",
+ Tcb)
+ );
+
+ switch (Tcb->State) {
+ case TCP_SYN_RCVD:
+ case TCP_ESTABLISHED:
+
+ TcpSetState (Tcb, TCP_CLOSE_WAIT);
+ break;
+
+ case TCP_FIN_WAIT_1:
+
+ if (!TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
+
+ TcpSetState (Tcb, TCP_CLOSING);
+ break;
+ }
+
+ //
+ // fall through
+ //
+ case TCP_FIN_WAIT_2:
+
+ TcpSetState (Tcb, TCP_TIME_WAIT);
+ TcpClearAllTimer (Tcb);
+
+ if (Tcb->TimeWaitTimeout != 0) {
+
+ TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);
+ } else {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "Connection closed immediately because app disables TIME_WAIT timer for %p\n",
+ Tcb)
+ );
+
+ TcpSendAck (Tcb);
+ TcpClose (Tcb);
+ }
+ break;
+
+ case TCP_CLOSE_WAIT:
+ case TCP_CLOSING:
+ case TCP_LAST_ACK:
+ case TCP_TIME_WAIT:
+ //
+ // The peer sends to us junk FIN byte. Discard
+ // the buffer then reset the connection
+ //
+ NetbufFree (Nbuf);
+ return -1;
+ break;
+ default:
+ break;
+ }
+
+ TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
+
+ Seg->End--;
+ }
+
+ //
+ // Don't delay the ack if PUSH flag is on.
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_PSH)) {
+
+ TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
+ }
+
+ if (Nbuf->TotalSize != 0) {
+ Urgent = 0;
+
+ if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG) &&
+ TCP_SEQ_LEQ (Seg->Seq, Tcb->RcvUp)
+ ) {
+
+ if (TCP_SEQ_LEQ (Seg->End, Tcb->RcvUp)) {
+ Urgent = Nbuf->TotalSize;
+ } else {
+ Urgent = TCP_SUB_SEQ (Tcb->RcvUp, Seg->Seq) + 1;
+ }
+ }
+
+ SockDataRcvd (Tcb->Sk, Nbuf, Urgent);
+ }
+
+ if (TCP_FIN_RCVD (Tcb->State)) {
+
+ SockNoMoreData (Tcb->Sk);
+ }
+
+ NetbufFree (Nbuf);
+ }
+
+ return 0;
+}
+
+/**
+ Store the data into the reassemble queue.
+
+ @param[in, out] Tcb Pointer to the TCP_CB of this TCP instance.
+ @param[in] Nbuf Pointer to the buffer containing the data to be queued.
+
+**/
+VOID
+TcpQueueData (
+ IN OUT TCP_CB *Tcb,
+ IN NET_BUF *Nbuf
+ )
+{
+ TCP_SEG *Seg;
+ LIST_ENTRY *Head;
+ LIST_ENTRY *Prev;
+ LIST_ENTRY *Cur;
+ NET_BUF *Node;
+
+ ASSERT ((Tcb != NULL) && (Nbuf != NULL) && (Nbuf->Tcp == NULL));
+
+ NET_GET_REF (Nbuf);
+
+ Seg = TCPSEG_NETBUF (Nbuf);
+ Head = &Tcb->RcvQue;
+
+ //
+ // Fast path to process normal case. That is,
+ // no out-of-order segments are received.
+ //
+ if (IsListEmpty (Head)) {
+
+ InsertTailList (Head, &Nbuf->List);
+ return;
+ }
+
+ //
+ // Find the point to insert the buffer
+ //
+ for (Prev = Head, Cur = Head->ForwardLink;
+ Cur != Head;
+ Prev = Cur, Cur = Cur->ForwardLink
+ ) {
+
+ Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);
+
+ if (TCP_SEQ_LT (Seg->Seq, TCPSEG_NETBUF (Node)->Seq)) {
+ break;
+ }
+ }
+
+ //
+ // Check whether the current segment overlaps with the
+ // previous segment.
+ //
+ if (Prev != Head) {
+ Node = NET_LIST_USER_STRUCT (Prev, NET_BUF, List);
+
+ if (TCP_SEQ_LT (Seg->Seq, TCPSEG_NETBUF (Node)->End)) {
+
+ if (TCP_SEQ_LEQ (Seg->End, TCPSEG_NETBUF (Node)->End)) {
+
+ NetbufFree (Nbuf);
+ return;
+ }
+
+ TcpTrimSegment (Nbuf, TCPSEG_NETBUF (Node)->End, Seg->End);
+ }
+ }
+
+ InsertHeadList (Prev, &Nbuf->List);
+
+ TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
+
+ //
+ // Check the segments after the insert point.
+ //
+ while (Cur != Head) {
+ Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);
+
+ if (TCP_SEQ_LEQ (TCPSEG_NETBUF (Node)->End, Seg->End)) {
+
+ Cur = Cur->ForwardLink;
+
+ RemoveEntryList (&Node->List);
+ NetbufFree (Node);
+ continue;
+ }
+
+ if (TCP_SEQ_LT (TCPSEG_NETBUF (Node)->Seq, Seg->End)) {
+
+ if (TCP_SEQ_LEQ (TCPSEG_NETBUF (Node)->Seq, Seg->Seq)) {
+
+ RemoveEntryList (&Nbuf->List);
+ NetbufFree (Nbuf);
+ return;
+ }
+
+ TcpTrimSegment (Nbuf, Seg->Seq, TCPSEG_NETBUF (Node)->Seq);
+ break;
+ }
+
+ Cur = Cur->ForwardLink;
+ }
+}
+
+
+/**
+ Adjust the send queue or the retransmit queue.
+
+ @param[in] Tcb Pointer to the TCP_CB of this TCP instance.
+ @param[in] Ack The acknowledge seuqence number of the received segment.
+
+**/
+VOID
+TcpAdjustSndQue (
+ IN TCP_CB *Tcb,
+ IN TCP_SEQNO Ack
+ )
+{
+ LIST_ENTRY *Head;
+ LIST_ENTRY *Cur;
+ NET_BUF *Node;
+ TCP_SEG *Seg;
+
+ Head = &Tcb->SndQue;
+ Cur = Head->ForwardLink;
+
+ while (Cur != Head) {
+ Node = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);
+ Seg = TCPSEG_NETBUF (Node);
+
+ if (TCP_SEQ_GEQ (Seg->Seq, Ack)) {
+ break;
+ }
+
+ //
+ // Remove completely ACKed segments
+ //
+ if (TCP_SEQ_LEQ (Seg->End, Ack)) {
+ Cur = Cur->ForwardLink;
+
+ RemoveEntryList (&Node->List);
+ NetbufFree (Node);
+ continue;
+ }
+
+ TcpTrimSegment (Node, Ack, Seg->End);
+ break;
+ }
+}
+
+/**
+ Process the received TCP segments.
+
+ @param[in] Nbuf Buffer that contains received a TCP segment without an IP header.
+ @param[in] Src Source address of the segment, or the peer's IP address.
+ @param[in] Dst Destination address of the segment, or the local end's IP
+ address.
+ @param[in] Version IP_VERSION_4 indicates IP4 stack. IP_VERSION_6 indicates
+ IP6 stack.
+
+ @retval 0 Segment processed successfully. It is either accepted or
+ discarded. However, no connection is reset by the segment.
+ @retval -1 A connection is reset by the segment.
+
+**/
+INTN
+TcpInput (
+ IN NET_BUF *Nbuf,
+ IN EFI_IP_ADDRESS *Src,
+ IN EFI_IP_ADDRESS *Dst,
+ IN UINT8 Version
+ )
+{
+ TCP_CB *Tcb;
+ TCP_CB *Parent;
+ TCP_OPTION Option;
+ TCP_HEAD *Head;
+ INT32 Len;
+ TCP_SEG *Seg;
+ TCP_SEQNO Right;
+ TCP_SEQNO Urg;
+ UINT16 Checksum;
+
+ ASSERT ((Version == IP_VERSION_4) || (Version == IP_VERSION_6));
+
+ NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE);
+
+ Parent = NULL;
+ Tcb = NULL;
+
+ Head = (TCP_HEAD *) NetbufGetByte (Nbuf, 0, NULL);
+ ASSERT (Head != NULL);
+ Len = Nbuf->TotalSize - (Head->HeadLen << 2);
+
+ if ((Head->HeadLen < 5) || (Len < 0)) {
+
+ DEBUG ((EFI_D_INFO, "TcpInput: received an mal-formated packet\n"));
+ goto DISCARD;
+ }
+
+ if (Version == IP_VERSION_4) {
+ Checksum = NetPseudoHeadChecksum (Src->Addr[0], Dst->Addr[0], 6, 0);
+ } else {
+ Checksum = NetIp6PseudoHeadChecksum (&Src->v6, &Dst->v6, 6, 0);
+ }
+
+ Checksum = TcpChecksum (Nbuf, Checksum);
+
+ if (Checksum != 0) {
+ DEBUG ((EFI_D_ERROR, "TcpInput: received a checksum error packet\n"));
+ goto DISCARD;
+ }
+
+ if (TCP_FLG_ON (Head->Flag, TCP_FLG_SYN)) {
+ Len++;
+ }
+
+ if (TCP_FLG_ON (Head->Flag, TCP_FLG_FIN)) {
+ Len++;
+ }
+
+ Tcb = TcpLocateTcb (
+ Head->DstPort,
+ Dst,
+ Head->SrcPort,
+ Src,
+ Version,
+ (BOOLEAN) TCP_FLG_ON (Head->Flag, TCP_FLG_SYN)
+ );
+
+ if ((Tcb == NULL) || (Tcb->State == TCP_CLOSED)) {
+ DEBUG ((EFI_D_INFO, "TcpInput: send reset because no TCB find\n"));
+
+ Tcb = NULL;
+ goto SEND_RESET;
+ }
+
+ Seg = TcpFormatNetbuf (Tcb, Nbuf);
+
+ //
+ // RFC1122 recommended reaction to illegal option
+ // (in fact, an illegal option length) is reset.
+ //
+ if (TcpParseOption (Nbuf->Tcp, &Option) == -1) {
+ DEBUG (
+ (EFI_D_ERROR,
+ "TcpInput: reset the peer because of mal-format option for Tcb %p\n",
+ Tcb)
+ );
+
+ goto SEND_RESET;
+ }
+
+ //
+ // From now on, the segment is headless
+ //
+ NetbufTrim (Nbuf, (Head->HeadLen << 2), NET_BUF_HEAD);
+ Nbuf->Tcp = NULL;
+
+ //
+ // Process the segment in LISTEN state.
+ //
+ if (Tcb->State == TCP_LISTEN) {
+ //
+ // First step: Check RST
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: discard a reset segment for TCB %p in listening\n",
+ Tcb)
+ );
+
+ goto DISCARD;
+ }
+
+ //
+ // Second step: Check ACK.
+ // Any ACK sent to TCP in LISTEN is reseted.
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: send reset because of segment with ACK for TCB %p in listening\n",
+ Tcb)
+ );
+
+ goto SEND_RESET;
+ }
+
+ //
+ // Third step: Check SYN
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
+ //
+ // create a child TCB to handle the data
+ //
+ Parent = Tcb;
+
+ Tcb = TcpCloneTcb (Parent);
+ if (Tcb == NULL) {
+ DEBUG (
+ (EFI_D_ERROR,
+ "TcpInput: discard a segment because failed to clone a child for TCB%p\n",
+ Tcb)
+ );
+
+ goto DISCARD;
+ }
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpInput: create a child for TCB %p in listening\n",
+ Tcb)
+ );
+
+ //
+ // init the TCB structure
+ //
+ IP6_COPY_ADDRESS (&Tcb->LocalEnd.Ip, Dst);
+ IP6_COPY_ADDRESS (&Tcb->RemoteEnd.Ip, Src);
+ Tcb->LocalEnd.Port = Head->DstPort;
+ Tcb->RemoteEnd.Port = Head->SrcPort;
+
+ TcpInitTcbLocal (Tcb);
+ TcpInitTcbPeer (Tcb, Seg, &Option);
+
+ TcpSetState (Tcb, TCP_SYN_RCVD);
+ TcpSetTimer (Tcb, TCP_TIMER_CONNECT, Tcb->ConnectTimeout);
+ TcpTrimInWnd (Tcb, Nbuf);
+
+ goto StepSix;
+ }
+
+ goto DISCARD;
+
+ } else if (Tcb->State == TCP_SYN_SENT) {
+ //
+ // First step: Check ACK bit
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK) && (Seg->Ack != Tcb->Iss + 1)) {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: send reset because of wrong ACK received for TCB %p in SYN_SENT\n",
+ Tcb)
+ );
+
+ goto SEND_RESET;
+ }
+
+ //
+ // Second step: Check RST bit
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
+
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: connection reset by peer for TCB %p in SYN_SENT\n",
+ Tcb)
+ );
+
+ SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
+ goto DROP_CONNECTION;
+ } else {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: discard a reset segment because of no ACK for TCB %p in SYN_SENT\n",
+ Tcb)
+ );
+
+ goto DISCARD;
+ }
+ }
+
+ //
+ // Third step: Check security and precedence. Skipped
+ //
+
+ //
+ // Fourth step: Check SYN. Pay attention to sitimulatous open
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
+
+ TcpInitTcbPeer (Tcb, Seg, &Option);
+
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
+
+ Tcb->SndUna = Seg->Ack;
+ }
+
+ TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
+
+ if (TCP_SEQ_GT (Tcb->SndUna, Tcb->Iss)) {
+
+ TcpSetState (Tcb, TCP_ESTABLISHED);
+
+ TcpClearTimer (Tcb, TCP_TIMER_CONNECT);
+ TcpDeliverData (Tcb);
+
+ if ((Tcb->CongestState == TCP_CONGEST_OPEN) &&
+ TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)
+ ) {
+
+ TcpComputeRtt (Tcb, Tcb->RttMeasure);
+ TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);
+ }
+
+ TcpTrimInWnd (Tcb, Nbuf);
+
+ TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpInput: connection established for TCB %p in SYN_SENT\n",
+ Tcb)
+ );
+
+ goto StepSix;
+ } else {
+ //
+ // Received a SYN segment without ACK, simultanous open.
+ //
+ TcpSetState (Tcb, TCP_SYN_RCVD);
+
+ ASSERT (Tcb->SndNxt == Tcb->Iss + 1);
+ TcpAdjustSndQue (Tcb, Tcb->SndNxt);
+
+ TcpTrimInWnd (Tcb, Nbuf);
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: simultanous open for TCB %p in SYN_SENT\n",
+ Tcb)
+ );
+
+ goto StepSix;
+ }
+ }
+
+ goto DISCARD;
+ }
+
+ //
+ // Process segment in SYN_RCVD or TCP_CONNECTED states
+ //
+
+ //
+ // Clear probe timer since the RecvWindow is opened.
+ //
+ if (Tcb->ProbeTimerOn && (Seg->Wnd != 0)) {
+ TcpClearTimer (Tcb, TCP_TIMER_PROBE);
+ Tcb->ProbeTimerOn = FALSE;
+ }
+
+ //
+ // First step: Check whether SEG.SEQ is acceptable
+ //
+ if (TcpSeqAcceptable (Tcb, Seg) == 0) {
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: sequence acceptance test failed for segment of TCB %p\n",
+ Tcb)
+ );
+
+ if (!TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
+ TcpSendAck (Tcb);
+ }
+
+ goto DISCARD;
+ }
+
+ if ((TCP_SEQ_LT (Seg->Seq, Tcb->RcvWl2)) &&
+ (Tcb->RcvWl2 == Seg->End) &&
+ !TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN | TCP_FLG_FIN)
+ ) {
+
+ TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
+ }
+
+ //
+ // Second step: Check the RST
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_RST)) {
+
+ DEBUG ((EFI_D_WARN, "TcpInput: connection reset for TCB %p\n", Tcb));
+
+ if (Tcb->State == TCP_SYN_RCVD) {
+
+ SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_REFUSED);
+
+ //
+ // This TCB comes from either a LISTEN TCB,
+ // or active open TCB with simultanous open.
+ // Do NOT signal user CONNECTION refused
+ // if it comes from a LISTEN TCB.
+ //
+ } else if ((Tcb->State == TCP_ESTABLISHED) ||
+ (Tcb->State == TCP_FIN_WAIT_1) ||
+ (Tcb->State == TCP_FIN_WAIT_2) ||
+ (Tcb->State == TCP_CLOSE_WAIT)
+ ) {
+
+ SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
+
+ } else {
+ }
+
+ goto DROP_CONNECTION;
+ }
+
+ //
+ // Trim the data and flags.
+ //
+ TcpTrimInWnd (Tcb, Nbuf);
+
+ //
+ // Third step: Check security and precedence, Ignored
+ //
+
+ //
+ // Fourth step: Check the SYN bit.
+ //
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_SYN)) {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: connection reset because received extra SYN for TCB %p\n",
+ Tcb)
+ );
+
+ SOCK_ERROR (Tcb->Sk, EFI_CONNECTION_RESET);
+ goto RESET_THEN_DROP;
+ }
+ //
+ // Fifth step: Check the ACK
+ //
+ if (!TCP_FLG_ON (Seg->Flag, TCP_FLG_ACK)) {
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: segment discard because of no ACK for connected TCB %p\n",
+ Tcb)
+ );
+
+ goto DISCARD;
+ } else {
+ if (Tcb->IpInfo->IpVersion == IP_VERSION_6 && Tcb->Tick == 0) {
+ Tcp6RefreshNeighbor (Tcb, Src, TCP6_KEEP_NEIGHBOR_TIME * TICKS_PER_SECOND);
+ Tcb->Tick = TCP6_REFRESH_NEIGHBOR_TICK;
+ }
+ }
+
+ if (Tcb->State == TCP_SYN_RCVD) {
+
+ if (TCP_SEQ_LT (Tcb->SndUna, Seg->Ack) && TCP_SEQ_LEQ (Seg->Ack, Tcb->SndNxt)) {
+
+ Tcb->SndWnd = Seg->Wnd;
+ Tcb->SndWndMax = MAX (Tcb->SndWnd, Tcb->SndWndMax);
+ Tcb->SndWl1 = Seg->Seq;
+ Tcb->SndWl2 = Seg->Ack;
+ TcpSetState (Tcb, TCP_ESTABLISHED);
+
+ TcpClearTimer (Tcb, TCP_TIMER_CONNECT);
+ TcpDeliverData (Tcb);
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpInput: connection established for TCB %p in SYN_RCVD\n",
+ Tcb)
+ );
+
+ //
+ // Continue the process as ESTABLISHED state
+ //
+ } else {
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: send reset because of wrong ACK for TCB %p in SYN_RCVD\n",
+ Tcb)
+ );
+
+ goto SEND_RESET;
+ }
+ }
+
+ if (TCP_SEQ_LT (Seg->Ack, Tcb->SndUna)) {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: ignore the out-of-data ACK for connected TCB %p\n",
+ Tcb)
+ );
+
+ goto StepSix;
+
+ } else if (TCP_SEQ_GT (Seg->Ack, Tcb->SndNxt)) {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: discard segment for future ACK for connected TCB %p\n",
+ Tcb)
+ );
+
+ TcpSendAck (Tcb);
+ goto DISCARD;
+ }
+
+ //
+ // From now on: SND.UNA <= SEG.ACK <= SND.NXT.
+ //
+ if (TCP_FLG_ON (Option.Flag, TCP_OPTION_RCVD_TS)) {
+ //
+ // update TsRecent as specified in page 16 RFC1323.
+ // RcvWl2 equals to the variable "LastAckSent"
+ // defined there.
+ //
+ if (TCP_SEQ_LEQ (Seg->Seq, Tcb->RcvWl2) && TCP_SEQ_LT (Tcb->RcvWl2, Seg->End)) {
+
+ Tcb->TsRecent = Option.TSVal;
+ Tcb->TsRecentAge = mTcpTick;
+ }
+
+ TcpComputeRtt (Tcb, TCP_SUB_TIME (mTcpTick, Option.TSEcr));
+
+ } else if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RTT_ON)) {
+
+ ASSERT (Tcb->CongestState == TCP_CONGEST_OPEN);
+
+ TcpComputeRtt (Tcb, Tcb->RttMeasure);
+ TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_RTT_ON);
+ }
+
+ if (Seg->Ack == Tcb->SndNxt) {
+
+ TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
+ } else {
+
+ TcpSetTimer (Tcb, TCP_TIMER_REXMIT, Tcb->Rto);
+ }
+
+ //
+ // Count duplicate acks.
+ //
+ if ((Seg->Ack == Tcb->SndUna) &&
+ (Tcb->SndUna != Tcb->SndNxt) &&
+ (Seg->Wnd == Tcb->SndWnd) &&
+ (0 == Len)
+ ) {
+
+ Tcb->DupAck++;
+ } else {
+
+ Tcb->DupAck = 0;
+ }
+
+ //
+ // Congestion avoidance, fast recovery and fast retransmission.
+ //
+ if (((Tcb->CongestState == TCP_CONGEST_OPEN) && (Tcb->DupAck < 3)) ||
+ (Tcb->CongestState == TCP_CONGEST_LOSS)
+ ) {
+
+ if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {
+
+ if (Tcb->CWnd < Tcb->Ssthresh) {
+
+ Tcb->CWnd += Tcb->SndMss;
+ } else {
+
+ Tcb->CWnd += MAX (Tcb->SndMss * Tcb->SndMss / Tcb->CWnd, 1);
+ }
+
+ Tcb->CWnd = MIN (Tcb->CWnd, TCP_MAX_WIN << Tcb->SndWndScale);
+ }
+
+ if (Tcb->CongestState == TCP_CONGEST_LOSS) {
+ TcpFastLossRecover (Tcb, Seg);
+ }
+ } else {
+
+ TcpFastRecover (Tcb, Seg);
+ }
+
+ if (TCP_SEQ_GT (Seg->Ack, Tcb->SndUna)) {
+
+ TcpAdjustSndQue (Tcb, Seg->Ack);
+ Tcb->SndUna = Seg->Ack;
+
+ if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_SND_URG) &&
+ TCP_SEQ_LT (Tcb->SndUp, Seg->Ack)
+ ) {
+
+ TCP_CLEAR_FLG (Tcb->CtrlFlag, TCP_CTRL_SND_URG);
+ }
+ }
+
+ //
+ // Update window info
+ //
+ if (TCP_SEQ_LT (Tcb->SndWl1, Seg->Seq) ||
+ ((Tcb->SndWl1 == Seg->Seq) && TCP_SEQ_LEQ (Tcb->SndWl2, Seg->Ack))
+ ) {
+
+ Right = Seg->Ack + Seg->Wnd;
+
+ if (TCP_SEQ_LT (Right, Tcb->SndWl2 + Tcb->SndWnd)) {
+
+ if ((Tcb->SndWl1 == Seg->Seq) &&
+ (Tcb->SndWl2 == Seg->Ack) &&
+ (Len == 0)
+ ) {
+
+ goto NO_UPDATE;
+ }
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: peer shrinks the window for connected TCB %p\n",
+ Tcb)
+ );
+
+ if ((Tcb->CongestState == TCP_CONGEST_RECOVER) && (TCP_SEQ_LT (Right, Tcb->Recover))) {
+
+ Tcb->Recover = Right;
+ }
+
+ if ((Tcb->CongestState == TCP_CONGEST_LOSS) && (TCP_SEQ_LT (Right, Tcb->LossRecover))) {
+
+ Tcb->LossRecover = Right;
+ }
+
+ if (TCP_SEQ_LT (Right, Tcb->SndNxt)) {
+
+ Tcb->SndNxt = Right;
+
+ if (Right == Tcb->SndUna) {
+
+ TcpClearTimer (Tcb, TCP_TIMER_REXMIT);
+ TcpSetProbeTimer (Tcb);
+ }
+ }
+ }
+
+ Tcb->SndWnd = Seg->Wnd;
+ Tcb->SndWndMax = MAX (Tcb->SndWnd, Tcb->SndWndMax);
+ Tcb->SndWl1 = Seg->Seq;
+ Tcb->SndWl2 = Seg->Ack;
+ }
+
+NO_UPDATE:
+
+ if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_SENT) && (Tcb->SndUna == Tcb->SndNxt)) {
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpInput: local FIN is ACKed by peer for connected TCB %p\n",
+ Tcb)
+ );
+
+ TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED);
+ }
+
+ //
+ // Transit the state if proper.
+ //
+ switch (Tcb->State) {
+ case TCP_FIN_WAIT_1:
+
+ if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
+
+ TcpSetState (Tcb, TCP_FIN_WAIT_2);
+
+ TcpClearAllTimer (Tcb);
+ TcpSetTimer (Tcb, TCP_TIMER_FINWAIT2, Tcb->FinWait2Timeout);
+ }
+
+ case TCP_FIN_WAIT_2:
+
+ break;
+
+ case TCP_CLOSE_WAIT:
+ break;
+
+ case TCP_CLOSING:
+
+ if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
+
+ TcpSetState (Tcb, TCP_TIME_WAIT);
+
+ TcpClearAllTimer (Tcb);
+
+ if (Tcb->TimeWaitTimeout != 0) {
+
+ TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);
+ } else {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "Connection closed immediately because app disables TIME_WAIT timer for %p\n",
+ Tcb)
+ );
+
+ TcpClose (Tcb);
+ }
+ }
+ break;
+
+ case TCP_LAST_ACK:
+
+ if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_FIN_ACKED)) {
+
+ TcpSetState (Tcb, TCP_CLOSED);
+ }
+
+ break;
+
+ case TCP_TIME_WAIT:
+
+ TcpSendAck (Tcb);
+
+ if (Tcb->TimeWaitTimeout != 0) {
+
+ TcpSetTimer (Tcb, TCP_TIMER_2MSL, Tcb->TimeWaitTimeout);
+ } else {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "Connection closed immediately because app disables TIME_WAIT timer for %p\n",
+ Tcb)
+ );
+
+ TcpClose (Tcb);
+ }
+ break;
+
+ default:
+ break;
+ }
+ //
+ // Sixth step: Check the URG bit.update the Urg point
+ // if in TCP_CAN_RECV, otherwise, leave the RcvUp intact.
+ //
+StepSix:
+
+ Tcb->Idle = 0;
+ TcpSetKeepaliveTimer (Tcb);
+
+ if (TCP_FLG_ON (Seg->Flag, TCP_FLG_URG) && !TCP_FIN_RCVD (Tcb->State)) {
+
+ DEBUG (
+ (EFI_D_INFO,
+ "TcpInput: received urgent data from peer for connected TCB %p\n",
+ Tcb)
+ );
+
+ Urg = Seg->Seq + Seg->Urg;
+
+ if (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG) && TCP_SEQ_GT (Urg, Tcb->RcvUp)) {
+
+ Tcb->RcvUp = Urg;
+ } else {
+
+ Tcb->RcvUp = Urg;
+ TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_RCVD_URG);
+ }
+ }
+ //
+ // Seventh step: Process the segment data
+ //
+ if (Seg->End != Seg->Seq) {
+
+ if (TCP_FIN_RCVD (Tcb->State)) {
+
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: connection reset because data is lost for connected TCB %p\n",
+ Tcb)
+ );
+
+ goto RESET_THEN_DROP;
+ }
+
+ if (TCP_LOCAL_CLOSED (Tcb->State) && (Nbuf->TotalSize != 0)) {
+ DEBUG (
+ (EFI_D_WARN,
+ "TcpInput: connection reset because data is lost for connected TCB %p\n",
+ Tcb)
+ );
+
+ goto RESET_THEN_DROP;
+ }
+
+ TcpQueueData (Tcb, Nbuf);
+ if (TcpDeliverData (Tcb) == -1) {
+ goto RESET_THEN_DROP;
+ }
+
+ if (!IsListEmpty (&Tcb->RcvQue)) {
+ TCP_SET_FLG (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW);
+ }
+ }
+
+ //
+ // Eighth step: check the FIN.
+ // This step is moved to TcpDeliverData. FIN will be
+ // processed in sequence there. Check the comments in
+ // the beginning of the file header for information.
+ //
+
+ //
+ // Tcb is a new child of the listening Parent,
+ // commit it.
+ //
+ if (Parent != NULL) {
+ Tcb->Parent = Parent;
+ TcpInsertTcb (Tcb);
+ }
+
+ if ((Tcb->State != TCP_CLOSED) &&
+ (TcpToSendData (Tcb, 0) == 0) &&
+ (TCP_FLG_ON (Tcb->CtrlFlag, TCP_CTRL_ACK_NOW) || (Nbuf->TotalSize != 0))
+ ) {
+
+ TcpToSendAck (Tcb);
+ }
+
+ NetbufFree (Nbuf);
+ return 0;
+
+RESET_THEN_DROP:
+ TcpSendReset (Tcb, Head, Len, Dst, Src, Version);
+
+DROP_CONNECTION:
+ ASSERT ((Tcb != NULL) && (Tcb->Sk != NULL));
+
+ NetbufFree (Nbuf);
+ TcpClose (Tcb);
+
+ return -1;
+
+SEND_RESET:
+
+ TcpSendReset (Tcb, Head, Len, Dst, Src, Version);
+
+DISCARD:
+
+ //
+ // Tcb is a child of Parent, and it doesn't survive
+ //
+ DEBUG ((EFI_D_WARN, "TcpInput: Discard a packet\n"));
+ NetbufFree (Nbuf);
+
+ if ((Parent != NULL) && (Tcb != NULL)) {
+
+ ASSERT (Tcb->Sk != NULL);
+ TcpClose (Tcb);
+ }
+
+ return 0;
+}
+
+/**
+ Process the received ICMP error messages for TCP.
+
+ @param[in] Nbuf The buffer that contains part of the TCP segment without an IP header
+ truncated from the ICMP error packet.
+ @param[in] IcmpErr The ICMP error code interpreted from an ICMP error packet.
+ @param[in] Src Source address of the ICMP error message.
+ @param[in] Dst Destination address of the ICMP error message.
+ @param[in] Version IP_VERSION_4 indicates IP4 stack. IP_VERSION_6 indicates
+ IP6 stack.
+
+**/
+VOID
+TcpIcmpInput (
+ IN NET_BUF *Nbuf,
+ IN UINT8 IcmpErr,
+ IN EFI_IP_ADDRESS *Src,
+ IN EFI_IP_ADDRESS *Dst,
+ IN UINT8 Version
+ )
+{
+ TCP_HEAD *Head;
+ TCP_CB *Tcb;
+ TCP_SEQNO Seq;
+ EFI_STATUS IcmpErrStatus;
+ BOOLEAN IcmpErrIsHard;
+ BOOLEAN IcmpErrNotify;
+
+ Head = (TCP_HEAD *) NetbufGetByte (Nbuf, 0, NULL);
+ ASSERT (Head != NULL);
+
+ Tcb = TcpLocateTcb (
+ Head->DstPort,
+ Dst,
+ Head->SrcPort,
+ Src,
+ Version,
+ FALSE
+ );
+ if (Tcb == NULL || Tcb->State == TCP_CLOSED) {
+
+ goto CLEAN_EXIT;
+ }
+
+ //
+ // Validate the sequence number.
+ //
+ Seq = NTOHL (Head->Seq);
+ if (!(TCP_SEQ_LEQ (Tcb->SndUna, Seq) && TCP_SEQ_LT (Seq, Tcb->SndNxt))) {
+
+ goto CLEAN_EXIT;
+ }
+
+ IcmpErrStatus = IpIoGetIcmpErrStatus (IcmpErr, Tcb->Sk->IpVersion, &IcmpErrIsHard, &IcmpErrNotify);
+
+ if (IcmpErrNotify) {
+
+ SOCK_ERROR (Tcb->Sk, IcmpErrStatus);
+ }
+
+ if (IcmpErrIsHard) {
+
+ TcpClose (Tcb);
+ }
+
+CLEAN_EXIT:
+
+ NetbufFree (Nbuf);
+}
|