网络子系统28_桥接ioctl

//1.网桥子系统向用户空间提供的接口：//1.1 通过socket ioctl创建网桥//1.2 通过网桥的特殊设备文件ioctl添加网桥端口//桥接在socket ioctl中的衔接处理//处理的命令类型：//1.获取网桥信息//2.设置网桥信息//3.添加网桥//4.删除网桥1.1 static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg){...case SIOCGIFBR:case SIOCSIFBR:case SIOCBRADDBR:case SIOCBRDELBR:err = -ENOPKG;if (!br_ioctl_hook)//如果钩子函数没有被设置，则加载桥接模块request_module("bridge");down(&br_ioctl_mutex);//在执行钩子函数的过程中，获取信号量，防止在钩子函数被执行的过程，被设置if (br_ioctl_hook) err = br_ioctl_hook(cmd, argp);up(&br_ioctl_mutex);break;...}//网桥的socket ioctl//在网桥子系统初始化时，由brioctl_set设置br_ioctl_hook = br_ioctl_deviceless_stub//调用路径: sock_ioctl->br_ioctl_hook1.2 int br_ioctl_deviceless_stub(unsigned int cmd, void __user *uarg){switch (cmd) {case SIOCGIFBR:case SIOCSIFBR:return old_deviceless(uarg);//老式网桥命令case SIOCBRADDBR://新网桥命令，添加或删除网桥case SIOCBRDELBR:{char buf[IFNAMSIZ];if (!capable(CAP_NET_ADMIN))//当前进程需要admin权限return -EPERM;if (copy_from_user(buf, uarg, IFNAMSIZ))//uarg提供网桥名字return -EFAULT;buf[IFNAMSIZ-1] = 0;//c格式字符串if (cmd == SIOCBRADDBR)//添加网桥return br_add_bridge(buf);return br_del_bridge(buf);//删除}}return -EOPNOTSUPP;}//网桥老式ioctl命令处理//处理的命令类型为SIOCGIFBR, SIOCSIFBR//调用路径:br_ioctl_deviceless_stub->old_deviceless1.3 static int old_deviceless(void __user *uarg){unsigned long args[3];if (copy_from_user(args, uarg, sizeof(args)))//从用户空间拷贝参数return -EFAULT;switch (args[0]) {//由uarg[0]提供命令case BRCTL_GET_VERSION://获取网桥版本return BRCTL_VERSION;case BRCTL_GET_BRIDGES://获取网桥接口的index{int *indices;int ret = 0;indices = kmalloc(args[2]*sizeof(int), GFP_KERNEL);//uarg[2]指示获取接口数if (indices == NULL)return -ENOMEM;memset(indices, 0, args[2]*sizeof(int));args[2] = get_bridge_ifindices(indices, args[2]);//实际获取到的接口数ret = copy_to_user((void __user *)args[1], indices, args[2]*sizeof(int))//uarg[1]包含保存返回值的位置? -EFAULT : args[2];kfree(indices);return ret;}case BRCTL_ADD_BRIDGE://添加或删除网桥，网桥名主机内唯一case BRCTL_DEL_BRIDGE:{char buf[IFNAMSIZ];if (!capable(CAP_NET_ADMIN))//当前进程admin权限return -EPERM;if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))//uarg[1]保存网桥名的内存地址return -EFAULT;buf[IFNAMSIZ-1] = 0;//c风格字符串if (args[0] == BRCTL_ADD_BRIDGE)return br_add_bridge(buf);//添加网桥return br_del_bridge(buf);//删除网桥}}return -EOPNOTSUPP;}//网桥的特殊设备文件ioctl处理//通过打开网桥设备文件，ioctl//处理的命令：//1.老式网桥命令//2.新式添加删除网桥端口命令2.1 int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd){struct net_bridge *br = netdev_priv(dev);switch(cmd) {case SIOCDEVPRIVATE://老式命令return old_dev_ioctl(dev, rq, cmd);case SIOCBRADDIF://添加删除接口case SIOCBRDELIF:return add_del_if(br, rq->ifr_ifindex, cmd == SIOCBRADDIF);}pr_debug("Bridge does not support ioctl 0x%x\n", cmd);return -EOPNOTSUPP;}//遗留的老式设备文件ioctl//通过cmd=SIOCDEVPRIVATE调用//调用路径：br_dev_ioctl->old_dev_ioctl2.2 static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd){struct net_bridge *br = netdev_priv(dev);unsigned long args[4];if (copy_from_user(args, rq->ifr_data, sizeof(args)))return -EFAULT;switch (args[0]) {//删除添加接口case BRCTL_ADD_IF:case BRCTL_DEL_IF:return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);case BRCTL_GET_BRIDGE_INFO:{struct __bridge_info b;//获取网桥设备信息...if (copy_to_user((void __user *)args[1], &b, sizeof(b)))return -EFAULT;return 0;}case BRCTL_GET_PORT_LIST://获取网桥端口链表{int num, *indices;...//返回网桥端口的indexget_port_ifindices(br, indices, num);if (copy_to_user((void __user *)args[1], indices, num*sizeof(int)))num =  -EFAULT;kfree(indices);return num;}case BRCTL_SET_BRIDGE_FORWARD_DELAY://设置状态转移时间间隔if (!capable(CAP_NET_ADMIN))//当前进程需要admin权限return -EPERM;spin_lock_bh(&br->lock);br->bridge_forward_delay = clock_t_to_jiffies(args[1]);if (br_is_root_bridge(br))br->forward_delay = br->bridge_forward_delay;spin_unlock_bh(&br->lock);return 0;case BRCTL_SET_BRIDGE_HELLO_TIME://设置hello时间间隔if (!capable(CAP_NET_ADMIN))return -EPERM;spin_lock_bh(&br->lock);br->bridge_hello_time = clock_t_to_jiffies(args[1]);if (br_is_root_bridge(br))br->hello_time = br->bridge_hello_time;spin_unlock_bh(&br->lock);return 0;case BRCTL_SET_BRIDGE_MAX_AGE://BPDU信息的生存期if (!capable(CAP_NET_ADMIN))return -EPERM;spin_lock_bh(&br->lock);br->bridge_max_age = clock_t_to_jiffies(args[1]);if (br_is_root_bridge(br))br->max_age = br->bridge_max_age;spin_unlock_bh(&br->lock);return 0;case BRCTL_SET_AGEING_TIME://转发项的老化时间if (!capable(CAP_NET_ADMIN))return -EPERM;br->ageing_time = clock_t_to_jiffies(args[1]);return 0;case BRCTL_GET_PORT_INFO://端口信息{struct __port_info p;struct net_bridge_port *pt;rcu_read_lock();if ((pt = br_get_port(br, args[2])) == NULL) {rcu_read_unlock();return -EINVAL;}....rcu_read_unlock();if (copy_to_user((void __user *)args[1], &p, sizeof(p)))return -EFAULT;return 0;}case BRCTL_SET_BRIDGE_STP_STATE://启动或关闭stpif (!capable(CAP_NET_ADMIN))return -EPERM;br->stp_enabled = args[1]?1:0;return 0;case BRCTL_SET_BRIDGE_PRIORITY://设置网桥的优先级if (!capable(CAP_NET_ADMIN))return -EPERM;spin_lock_bh(&br->lock);br_stp_set_bridge_priority(br, args[1]);spin_unlock_bh(&br->lock);return 0;case BRCTL_SET_PORT_PRIORITY://设置端口的优先级{struct net_bridge_port *p;int ret = 0;if (!capable(CAP_NET_ADMIN))return -EPERM;if (args[2] >= (1<<(16-BR_PORT_BITS)))//2字节中，端口号使用的位数return -ERANGE;spin_lock_bh(&br->lock);if ((p = br_get_port(br, args[1])) == NULL) ret = -EINVAL;elsebr_stp_set_port_priority(p, args[2]);spin_unlock_bh(&br->lock);return ret;}case BRCTL_SET_PATH_COST://设置路径开销{struct net_bridge_port *p;int ret = 0;if (!capable(CAP_NET_ADMIN))return -EPERM;spin_lock_bh(&br->lock);if ((p = br_get_port(br, args[1])) == NULL)ret = -EINVAL;elsebr_stp_set_path_cost(p, args[2]);spin_unlock_bh(&br->lock);return ret;}case BRCTL_GET_FDB_ENTRIES://获取转发项的个数return get_fdb_entries(br, (void __user *)args[1],        args[2], args[3]);}return -EOPNOTSUPP;}