TCP/IP
网络协议栈
基于 linux 3.10
分为上篇和下篇，上 篇共九章，部侧重于 TCP/IP 数据收发流程，即 OSI
模型的 IP 和 TCP 层，下篇也是九章，并不属于 TCP/IP 本身，但是多少和
网络有关且常用到，比如 LC-trie 路由、netfilter 包过滤防火、还有一些
网络相关的命令行工具等，文末给出 IPV6 的协议栈模型图，此外还给出了
测试源码。
2015
葛世超
定价 0 元
2015/4/22
第零章内核网络相关配置选项 ............................................................................................... 5
0.1 Kconfig 选项 ....................................................................................................... 5
0.2 ip-sysctl 意义 ................................................................................................................... 8
第一章 网络子系统初始化 ............................................................................................ 9
1.1 网络初始化函数调用顺序 ............................................................................................. 9
1.2 调用函数浅析 .............................................................................................................. 12
1.3 inet_init ......................................................................................................................... 16
1.4 总结 .............................................................................................................................. 21
第二章 主机到网络层（网卡） ........................................................................................... 22
2.1 TCP/IP 协议栈模型 ....................................................................................................... 22
2.2 网卡数据结构 .............................................................................................................. 22
2.3 网卡注册流程 .............................................................................................................. 26
第三章 套接字相关数据结构 ............................................................................................... 31
3.1 socket 对应的内核结构体 ............................................................................................ 31
3.2 struct proto_ops ............................................................................................................ 33
3.3 struct proto .................................................................................................................... 33
3.4 sk_buff(SKB)................................................................................................................... 34
3.5 softnet_data .................................................................................................................. 35
3.6 struct packet_type ......................................................................................................... 36
3.7 一些名词简称 .............................................................................................................. 36
第四章 网络层接收数据包流程 ........................................................................................... 37
4.1 主机到网络层的过渡 .................................................................................................. 37
4.2 进入网络层 .................................................................................................................. 40
第五章 传输层（tcp）到网络层（ip） ............................................................................... 44
第六章 应用层 ....................................................................................................................... 49
第七章 tcp 发送（传输层) .................................................................................................... 55
7.2 MSS ............................................................................................................................ 69
第八章 tcp 接（传输层) ........................................................................................................ 70
第九章 tcp 拥塞控制 ............................................................................................................. 79
9.1 CUBIC 拥塞控制 ............................................................................................................ 79
cubic 使用的算法 ............................................................................................................ 79
cubic 慢启动门限阈值 .................................................................................................... 79
9.2 cubic 拥塞代码实现 ...................................................................................................... 82
慢启动 slow start ............................................................................................................ 82
拥塞避免 congestion avoid .......................................................................................... 83
快速重传和快速恢复 ..................................................................................................... 85
下篇 杂项汇总 ....................................................................................................................... 86
第十章 网络工具 ................................................................................................................... 87
10.1 ss .................................................................................................................................. 87
10.2 netstat ......................................................................................................................... 88
列标题 ............................................................................................................................. 88
常用选项 ......................................................................................................................... 89
10.3 netstress ...................................................................................................................... 89
10.4 netperf 参考 ................................................................................................................ 90
10.5 iperf ............................................................................................................................. 90
10.6 iptraf ............................................................................................................................ 90
10.7 TcpDump ..................................................................................................................... 91
10.7.1 数据过滤 ............................................................................................................. 91
10.7.2 输入输出 ............................................................................................................. 92
10.8 nicstat .......................................................................................................................... 92
10.8.1 nicstat 的安装: ..................................................................................................... 92
10.8.2 nicstat 使用 .......................................................................................................... 93
10.9 ethtool 工具： ............................................................................................................ 95
第十一章 Linux 包过滤防火墙-netfilter iptables ................................................................. 96
11.1 netfilter 框架 ............................................................................................................... 96
11.2 防火墙规则表 .......................................................................................................... 104
11.2.1 xt_init 初始化防火墙表 ..................................................................................... 106
11.2.2 规则的组成 ....................................................................................................... 108
11.3 防火墙规则遍历 ...................................................................................................... 110
11.3.2 Hook 函数 .......................................................................................................... 117
11.4 iptables ...................................................................................................................... 123
第十二章 路由 ..................................................................................................................... 124
12.1 路由核心数据结构 ................................................................................................... 124
12.2 LC-trie（字典树、单词查找树） ............................................................................ 127
12.3 ifconfig ....................................................................................................................... 132
12.3.1 /proc/net/路由下路由信息 ............................................................................... 132
12.3.2 路由通知链函数的注册 ................................................................................... 133
12.3.3 ifconfig 调用流程 ............................................................................................... 134
12.3.4 put_child ............................................................................................................. 153
12.4 route 添加路由项 ..................................................................................................... 154
12.5 路由缓存 .................................................................................................................. 161
12.5.1 路由缓存的查找 ............................................................................................... 161
12.5.2 路由缓存的创建 ............................................................................................... 162
12.5.3 路由缓存的内存管理 ....................................................................................... 166
12.6 路由查找 .................................................................................................................. 166
12.6.1 相关数据结构 ................................................................................................... 166
12.6.2 接收包路由项查找 ........................................................................................... 170
第十三章 网络命名空间 ..................................................................................................... 177
13.1 命名空间创建 .......................................................................................................... 177
13.2 网络命名空间管理 .................................................................................................. 178
第十四章 netlink 机制 ......................................................................................................... 181
14.1 netlink 支持的通信 ................................................................................................... 181
14.2 netlink 用户空间 API ................................................................................................ 184
14.3 netlink 内核空间 API ................................................................................................ 184
第十五章 提升网络性能技术 ............................................................................................. 188
15.1 TSO/GSO .................................................................................................................... 189
15.2 LRO/GRO .................................................................................................................... 191
15.3 RSS（Receive Side Scaling）队列： ......................................................................... 196
15.4 RPS（Receive Packet Steering）队列： .................................................................. 196
15.5 RFS(Receive Flow Steering)，Accelerated Receive Flow Steering ............................ 199
15.6 XPS（Transmit Packet Steering） ............................................................................. 200
第十六章 PHY ...................................................................................................................... 203
16.1 PHY ............................................................................................................................ 203
16.2 MAC 驱动 .................................................................................................................. 205
16.3 PHY 驱动 ................................................................................................................... 209
16.3.1 PHY 初始化......................................................................................................... 209
16.3.2 PHY 驱动实例..................................................................................................... 211
16.3.3 PHY 状态机......................................................................................................... 213
第十七章 ping-icmp ............................................................................................................. 218
第十八章 ipv6 简介 ............................................................................................................. 223
附录 tcp 测试程序 ............................................................................................................... 224
TCP/IP 状态图 ....................................................................................................................... 227
参考文献 ............................................................................................................................... 228
