From bea1fd210b84e28583da9674ec1b9ee6b5e0f3f6 Mon Sep 17 00:00:00 2001
From: impact-eintr <yixingwei4@gmail.com>
Date: Wed, 7 Dec 2022 21:28:51 +0800
Subject: [PATCH] =?UTF-8?q?=E5=A5=BD=E9=9A=BE=20=E5=A5=BD=E9=9A=BE=20?=
 =?UTF-8?q?=E5=A5=BD=E9=9A=BE=20ListenLoop=E7=9A=84Sleeper=E4=B8=BA?=
 =?UTF-8?q?=E4=BB=80=E4=B9=88=E6=B2=A1=E6=9C=89=E8=A2=AB=E5=94=A4=E9=86=92?=
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Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .vscode/c_cpp_properties.json  | 17 -----------------
 sleep/sleep_unsafe.go          |  2 ++
 tcpip/buffer/prependable.go    |  2 +-
 tcpip/network/ipv4/ipv4.go     |  7 +++++--
 tcpip/transport/tcp/accept.go  |  6 ++++++
 tcpip/transport/tcp/connect.go | 17 ++++++++---------
 6 files changed, 22 insertions(+), 29 deletions(-)
 delete mode 100644 .vscode/c_cpp_properties.json

diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json
deleted file mode 100644
index f6d7322..0000000
--- a/.vscode/c_cpp_properties.json
+++ /dev/null
@@ -1,17 +0,0 @@
-{
-    "configurations": [
-        {
-            "name": "Win32",
-            "includePath": [
-                "${workspaceFolder}/**"
-            ],
-            "defines": [
-                "_DEBUG",
-                "UNICODE",
-                "_UNICODE"
-            ],
-            "intelliSenseMode": "windows-msvc-x64"
-        }
-    ],
-    "version": 4
-}
\ No newline at end of file
diff --git a/sleep/sleep_unsafe.go b/sleep/sleep_unsafe.go
index 0aca751..43478e4 100644
--- a/sleep/sleep_unsafe.go
+++ b/sleep/sleep_unsafe.go
@@ -233,7 +233,9 @@ func (s *Sleeper) Fetch(block bool) (id int, ok bool) {
 		// Reassociate the waker with the sleeper. If the waker was
 		// still asserted we can return it, otherwise try the next one.
 		old := (*Sleeper)(atomic.SwapPointer(&w.s, usleeper(s)))
+		log.Println("Sleeper", unsafe.Pointer(s), "old", unsafe.Pointer(old), "&assertSleeper", unsafe.Pointer(&assertedSleeper), "w.id", w.id)
 		if old == &assertedSleeper {
+			log.Println("成功返回 没有阻塞")
 			return w.id, true
 		}
 	}
diff --git a/tcpip/buffer/prependable.go b/tcpip/buffer/prependable.go
index 02bdef6..ea1c8f9 100644
--- a/tcpip/buffer/prependable.go
+++ b/tcpip/buffer/prependable.go
@@ -23,7 +23,7 @@ func (p Prependable) UsedLength() int {
 	return len(p.buf) - p.usedIdx
 }
 
-// 从内到外暴露报文头的协议 eth|ipv4|tcp
+// Prepend 向前扩展size个字节
 func (p *Prependable) Prepend(size int) []byte {
 	if size > p.usedIdx {
 		return nil
diff --git a/tcpip/network/ipv4/ipv4.go b/tcpip/network/ipv4/ipv4.go
index cac91e0..5b0d8e6 100644
--- a/tcpip/network/ipv4/ipv4.go
+++ b/tcpip/network/ipv4/ipv4.go
@@ -110,8 +110,11 @@ func (e *endpoint) WritePacket(r *stack.Route, hdr buffer.Prependable, payload b
 	if protocol == header.ICMPv4ProtocolNumber {
 		log.Println("IP 写回ICMP报文", header.IPv4(append(ip, payload.ToView()...)))
 	} else {
-		//log.Printf("send ipv4 packet %d bytes, proto: 0x%x", hdr.UsedLength()+payload.Size(), protocol)
-		log.Println(header.IPv4(append(ip, payload.ToView()...)))
+		if payload.Size() == 0 {
+			log.Printf("send ipv4 packet %d bytes, proto: 0x%x", hdr.UsedLength()+payload.Size(), protocol)
+		} else {
+			log.Println(header.IPv4(append(ip, payload.ToView()...)))
+		}
 	}
 	return e.linkEP.WritePacket(r, hdr, payload, ProtocolNumber)
 }
diff --git a/tcpip/transport/tcp/accept.go b/tcpip/transport/tcp/accept.go
index 3640967..88ac2e0 100644
--- a/tcpip/transport/tcp/accept.go
+++ b/tcpip/transport/tcp/accept.go
@@ -263,6 +263,7 @@ func (e *endpoint) handleSynSegment(ctx *listenContext, s *segment, opts *header
 // handleListenSegment is called when a listening endpoint receives a segment
 // and needs to handle it.
 func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) {
+	log.Println(s.flags)
 	switch s.flags {
 	case flagSyn: // syn报文处理
 		// 分析tcp选项
@@ -276,6 +277,8 @@ func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) {
 	// 返回一个syn+ack报文
 	case flagFin: // fin报文处理
 		// 三次握手最后一次 ack 报文
+	default:
+		panic(nil)
 	}
 }
 
@@ -306,6 +309,7 @@ func (e *endpoint) protocolListenLoop(rcvWnd seqnum.Size) *tcpip.Error {
 	for {
 		switch index, _ := s.Fetch(true); index { // Fetch(true) 阻塞获取
 		case wakerForNewSegment:
+			log.Println("新数据来咯 欸嘿嘿嘿")
 			mayRequeue := true
 			// 接收和处理tcp报文
 			for i := 0; i < maxSegmentsPerWake; i++ {
@@ -325,6 +329,8 @@ func (e *endpoint) protocolListenLoop(rcvWnd seqnum.Size) *tcpip.Error {
 		case wakerForNotification:
 			// TODO 触发其他事件
 			log.Println("其他事件?")
+		default:
+			panic((nil))
 		}
 	}
 }
diff --git a/tcpip/transport/tcp/connect.go b/tcpip/transport/tcp/connect.go
index d0618ed..30961e0 100644
--- a/tcpip/transport/tcp/connect.go
+++ b/tcpip/transport/tcp/connect.go
@@ -205,14 +205,14 @@ func (h *handshake) execute() *tcpip.Error {
 			// 如果是客户端当发送 syn 报文，超过一定的时间未收到回包，触发超时重传
 			// 如果是服务端当发送 syn+ack 报文，超过一定的时间未收到 ack 回包，触发超时重传
 			// 超时时间变为上次的2倍
-			timeOut *= 2
-			if timeOut > 60*time.Second {
-				return tcpip.ErrTimeout
-			}
-			rt.Reset(timeOut)
-			// 重新发送syn报文
-			sendSynTCP(&h.ep.route, h.ep.id, h.flags, h.iss, h.ackNum, h.rcvWnd, synOpts)
-
+			//timeOut *= 2
+			//if timeOut > 60*time.Second {
+			//	return tcpip.ErrTimeout
+			//}
+			//rt.Reset(timeOut)
+			//// 重新发送syn报文
+			//sendSynTCP(&h.ep.route, h.ep.id, h.flags, h.iss, h.ackNum, h.rcvWnd, synOpts)
+			log.Println("超时重发了 xdm")
 		case wakerForNotification:
 
 		case wakerForNewSegment:
@@ -308,7 +308,6 @@ func sendSynTCP(r *stack.Route, id stack.TransportEndpointID, flags byte,
 // 发送一个tcp段数据，封装 tcp 首部，并写入网路层
 func sendTCP(r *stack.Route, id stack.TransportEndpointID, data buffer.VectorisedView, ttl uint8, flags byte,
 	seq, ack seqnum.Value, rcvWnd seqnum.Size, opts []byte) *tcpip.Error {
-	log.Println("进行一个报文的发送")
 	optLen := len(opts)
 	// Allocate a buffer for the TCP header.
 	hdr := buffer.NewPrependable(header.TCPMinimumSize + int(r.MaxHeaderLength()) + optLen)