supermartian

IT IS PAINFUL.

./configure --disable-sanity-checks CFLAGS="-O2 -U_FORTIFY_SOURCE -fno-stack-protector -march=native" --disable-profile --enable-kernel=2.6.25

supermartian

pthread mutex lock comes with different types:
1. private: process only
2. shared: cross the process boundary

Private:
Spins in the userspace for a while, after a timeout, goes to futex. In this way it saves some system calls.

Shared:
Goes to futex directly.

supermartian

opkg install kernel-dev
opkg install wireless-tools
CONFIG_POWER_SAVING=n

supermartian

<M>   Hierarchical Token Bucket (HTB)
<M>   Hierarchical Fair Service Curve (HFSC)
<M>   Multi Band Priority Queueing (PRIO) (NEW)
<M>   Stochastic Fairness Queueing (SFQ)
<M>   Token Bucket Filter (TBF) (NEW)
<M>   Elementary classification (BASIC)
<M>   Traffic-Control Index (TCINDEX)
<M>   Routing decision (ROUTE)
<M>   Netfilter mark (FW)
<M>   Universal 32bit comparisons w/ hashing (U32)

supermartian

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <memory.h>
#include <linux/types.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>

struct nl_req_s {

supermartian

1、Netfilter核心基于在IP层插入的5个HOOK
    PREROUTING:     NF_IP_PRE_ROUTING
    LOCAL_INPUT:    NF_IP_LOCAL_IN    
    FORWARD:        NF_IP_FORWARD
    LOCAL_OUTPUT:   NF_IP_LOCAL_OUT
    POSTROUTING:    NF_IP_POST_ROUTING

2、Netfilter在PRE_ROUTING和LOCAL_OUT处进行分片重组，也就是进入Netfilter的模块确保全部都是不分片的（？）
    nf_defrag_ipv4.c
    重组从外面进来的包，和本地主机生成的数据包