iptables和tc的使用及开发实例总结

AP处理专线CPE的实例及实现的逻辑算法：

1、CPE桥接关联AP，它们在同一个桥上面；

2、初始化tc规则：

int tc_rule_init( void )

{

char filename[256] = {0};

char ifname[32] = {0};

char enable[10] = {0};

char uplink[10] = {0};

char downlink[10] = {0};

FILE *fp = NULL;

char *ifname_up = "eth0";

strcpy(filename, "/var/etc/wlan_tc_init.sh");

fp = fopen(filename, "w");

if (fp == NULL)

{

log(LG_ERR, "can't create file \"%s\"", filename);

return -1;

}

fchmod(fileno(fp), 0755);

fprintf(fp, "#!/bin/sh\n");

nvramGetValue("wlan0/enable", enable, sizeof(enable));

//for downlink

if (atoi(enable) == 1)

{

strcpy(ifname, "wlan0");

nvramGetValue("wlan0/downlink_bandwidth", downlink, sizeof(downlink));

if (strlen(downlink) == 0)

strcpy(downlink, "500000");

fprintf(fp, "tc qdisc add dev %s root handle 1: htb default 100\n", ifname);

fprintf(fp, "tc class add dev %s parent 1: classid 1:1 htb rate %skbit ceil %skbit prio 1\n", ifname, downlink, downlink);

//default class

fprintf(fp, "tc class add dev %s parent 1:1 classid 1:100 htb rate 100kbit ceil %skbit prio 1\n", ifname, downlink);

}

nvramGetValue("ath0/enable", enable, sizeof(enable));

if (atoi(enable) == 1)

{

strcpy(ifname, "ath0");

memset(downlink, 0, sizeof(downlink));

nvramGetValue("ath0/downlink_bandwidth", downlink, sizeof(downlink));

if (strlen(downlink) == 0)

strcpy(downlink, "500000");

fprintf(fp, "tc qdisc add dev %s root handle 1: htb default 100\n", ifname);

fprintf(fp, "tc class add dev %s parent 1: classid 1:1 htb rate %skbit ceil %skbit prio 1\n", ifname, downlink, downlink);

fprintf(fp, "tc qdisc add dev %s parent 1:1 handle 11: sfq perturb 10\n", ifname);

//default class

fprintf(fp, "tc class add dev %s parent 1:1 classid 1:100 htb rate 100kbit ceil %skbit prio 1\n", ifname, downlink);

}

//for uplink

nvramGetValue("wlan0/uplink_bandwidth", uplink, sizeof(uplink));//for 2.4G classid 1:11

if (strlen(uplink) == 0)

strcpy(uplink, "500000");

fprintf(fp, "tc qdisc add dev %s root handle 1: htb default 100\n", ifname_up);

fprintf(fp, "tc class add dev %s parent 1: classid 1:1 htb rate 10000kbit ceil 10000kbit prio 1\n", ifname_up);

fprintf(fp, "tc class add dev %s parent 1:1 classid 1:11 htb rate %skbit ceil %skbit prio 1\n", ifname_up, uplink, uplink);

//default class

fprintf(fp, "tc class add dev %s parent 1:1 classid 1:100 htb rate 100kbit ceil %skbit prio 1\n", ifname_up, uplink);

memset(uplink, 0, sizeof(uplink));

nvramGetValue("ath0/uplink_bandwidth", uplink, sizeof(uplink));//for 5.8G classid 1:12

if (strlen(uplink) == 0)

strcpy(uplink, "500000");

fprintf(fp, "tc class add dev %s parent 1:1 classid 1:12 htb rate %skbit ceil %skbit prio 1\n", ifname_up, uplink, uplink);

//fprintf(fp, "tc qdisc add dev %s parent 1:12 handle 112: sfq perturb 10\n", ifname_up);

fclose(fp);

eval(filename);

return 1;

}

前两步实现基本流量控制操作，针对普通CPE的流量做的限制，对于专线CPE的流量配置，如下：

3、web端设置指定的CPE后，通过netlink发送mac到无线驱动端，无线驱动再netlink发送消息到上面处理流量控制的应用程序；

4、从无线接口端获取所有关联的cpe的mac地址；

typedef struct sta_buf

{

unsigned char sta_mac[32];

char ifname[32];

unsigned int max_uplink;

unsigned int min_uplink;

unsigned int max_downlink;

unsigned int min_downlink;

int parent_tag;

int tag;

int prio;

int online;

}*_p_sta_buf;将该Mac地址在存储于sta_buf结构体中的mac做查找；

若能找到，则设置这些mac地址的状态为在线；

若不能找到，则做如下处理；

判断是否在专线cpe列表中，如果在，则在 sta_buf结构体中标记为专线CPE，如果不在，则加入到sta_buf中；

设置mac为上线，并添加tc规则做流量控制；

5、当netlink将mac地址发送过来时，就会对mac的类型做判断，是上线，还是离线，还是加入网络，还是离开网络，并做好标记；然后对Mac添加tc规则做流量控制；

逻辑+标记