Kernel Study Notes

0.1. Summary0.1.1. Part 1: Register multi queue net device.In this part, only the framework is prepared for qdisc,and the noop_qdisc is set as default. 0.1.1.1. prepare netdev_queues.for example: inte

0.0.1. Qdisc_ops is the core of a Qdisc.All kinds of the Qdisc_ops are linked in a list by qdisc_base.The key item of different Qdisc_ops is id[IFNAMSIZ]. Note: the list is a Singly-linked list, not

0.0.1. IP HEADER以前找工作时，常被问到IP头都有哪些字段？现在觉得真的理解了记起来没那么难。 上路时总要记得终点和起点(src/dst ip),要倒几次车，大体也知道（ttl). 路有大路有小路，有高速路和土路。大路到小路要分片，小路到大路可能重组。上高速路需要通行证（qos/tos). 路上有警察，查你是不是非法(csum, header len, ip op

0.0.0.1. summaryTwo packets will be proessed by tcp server side: SYN pakcet: For the first packet(syn) of handshake, it first lookup the listen socket,and create a req socket as temporary. Send SYN+A

For the packet to localhost, ip_local_deliver_finish will be thelast funciton called by network layer. In ip_local_deliver_finish, it will be process the protocolhander of a array element of inet_prot

0.0.1. Data StructureEvery xsock has parent sock as its first filed.

0.0.1. Data struct.12345123 /* The inetsw table contains everything that inet_create needs to124 * build a new socket.125 */126 static struct list_head inetsw[SOCK_MAX];127 static DEFINE_SPINLOCK(in

0.0.1. Data Structure123451019 static const struct net_proto_family inet_family_ops = {1020 .family = PF_INET,1021 .create = inet_create,1022 .owner = THIS_MODULE,1023 &#

0.0.1. SummarySystem call socket will do two things: create a struct socket *sock. Mainly done by __sock_create, which alloc a struct socket *sock,then init it with the creating method of net_familie

0.0.1. summaryEach family has a corresponding array element of struct net_proto_family,which will be called in system call socket. 0.0.2. Data Structure123456181 struct net_proto_family {182