netifd [4] - interface

数据结构

/**
 * interface object
 */
struct interface {
    struct vlist_node node;
    struct list_head hotplug_list;
    enum interface_event hotplug_ev;

    const char *name;
    const char *ifname;

    bool available;
    bool autostart;
    bool config_autostart;
    bool device_config;
    bool enabled;
    bool link_state;
    bool force_link;
    bool dynamic;

    time_t start_time;
    enum interface_state state;
    enum interface_config_state config_state;
    enum interface_update_flags updated;

    struct list_head users;

    const char *parent_ifname;
    struct interface_user parent_iface;

    /* main interface that the interface is bound to */
    struct device_user main_dev;

    /* interface that layer 3 communication will go through */
    struct device_user l3_dev;

    struct blob_attr *config;

    /* primary protocol state */
    const struct proto_handler *proto_handler;
    struct interface_proto_state *proto;

    struct interface_ip_settings proto_ip;
    struct interface_ip_settings config_ip;
    struct vlist_tree host_routes;

    int metric;
    unsigned int ip4table;
    unsigned int ip6table;

    /* IPv6 assignment parameters */
    uint8_t assignment_length;
    int32_t assignment_hint;
    struct list_head assignment_classes;

    /* errors/warnings while trying to bring up the interface */
    struct list_head errors;

    /* extra data provided by protocol handlers or modules */
    struct avl_tree data;

    struct uloop_timeout remove_timer;
    struct ubus_object ubus;
};

enum interface_event {
    IFEV_DOWN,
    IFEV_UP,
    IFEV_UPDATE,
    IFEV_FREE,
    IFEV_RELOAD,
};

enum interface_state {
    IFS_SETUP,
    IFS_UP,
    IFS_TEARDOWN,
    IFS_DOWN,
};

enum interface_config_state {
    IFC_NORMAL,
    IFC_RELOAD,
    IFC_REMOVE
};

enum interface_update_flags {
    IUF_ADDRESS = (1 << 0),
    IUF_ROUTE   = (1 << 1),
    IUF_PREFIX  = (1 << 2),
    IUF_DATA    = (1 << 3),
};

struct interface_error {
    struct list_head list;

    const char *subsystem;
    const char *code;
    const char *data[];
};

/**
 * interface 引用
 */
struct interface_user {
    struct list_head list;
    struct interface *iface;
    void (*cb)(struct interface_user *dep, struct interface *iface, enum interface_event ev);
};

/**
 * interface ip 配置对象
 */
struct interface_ip_settings {
    struct interface *iface;
    bool enabled;
    bool no_defaultroute;
    bool no_dns;
    bool no_delegation;

    struct vlist_tree addr;
    struct vlist_tree route;
    struct vlist_tree prefix;

    struct vlist_simple_tree dns_servers;
    struct vlist_simple_tree dns_search;
};

struct interface_data {
    struct avl_node node;
    struct blob_attr data[];
};

struct interface_assignment_class {
    struct list_head head;
    char name[];
};

接口说明

/**
 * 根据输入配置创建并初始化interface object
 *
 * @param name interface name
 * @param config configure of interface object
 * @return interface object
 */
struct interface *interface_alloc(const char *name, struct blob_attr *config)

/**
 * 添加设置到interface中
 *
 * @param iface interface object
 * @param config configure of interface object
 */
void interface_add(struct interface *iface, struct blob_attr *config)

/**
 * 设置interface object的proto处理对象
 *
 * @param iface interface object
 * @param state proto handler object
 */
void interface_set_proto_state(struct interface *iface, struct interface_proto_state *state)

/**
 * 使能interface object
 *
 * @param iface interface object
 * @return true - success false - failed
 */
int interface_set_up(struct interface *iface)

/**
 * 停用interface object
 *
 * @param iface interface object
 * @return true - success false - failed
 */
int interface_set_down(struct interface *iface)

/**
 * 设置interface对象主device对象
 *
 * @param iface interface object
 * @param dev device object
 */
void interface_set_main_dev(struct interface *iface, struct device *dev)

/**
 * 设置interface对象3层device对象
 *
 * @param iface interface object
 * @param dev device object
 */
void interface_set_l3_dev(struct interface *iface, struct device *dev)

/**
 * 添加interface object引用
 *
 * @param dep interface reference object
 * @param iface interface object
 */
void interface_add_user(struct interface_user *dep, struct interface *iface)

/**
 * 删除interface object引用
 *
 * @param dep interface reference object
 */
void interface_remove_user(struct interface_user *dep)

/**
 *
 */
int interface_add_link(struct interface *iface, struct device *dev)

/**
 *
 */
int interface_remove_link(struct interface *iface, struct device *dev)

/**
 *
 */
int interface_handle_link(struct interface *iface, const char *name, bool add)

注意

interface对象avl tree链表设置了keep_old和no_delete标志，每次执行config_init_all时首先vlist_update把avl tree链表头结点的version标志加1,当根据UCI更新interface链表中对象时每个node的version保持与头结点version一致，后继做vlist_flush时如果存在node的version与头结点version不一致的将被删除，而netifd在删除某个interface时其实并没有把相应的对象从avl tree链表中删除，而是等下一次restart或reload时再