OVS端口模塊的重要數據結構3

1 端口模塊

struct vport {
	struct rcu_head rcu;                                     //一種鎖機制
	struct datapath	*dp;                                     //網橋結構體指針，表示該端口屬於哪個網橋的
	u32 upcall_portid;	                                     //Netlink端口收到的數據包時使用的端口id
	u16 port_no;                                             //端口號，唯一標識該端口

	// 因爲一個網橋上有多個端口，而這些端口都是用哈希鏈表來存儲的。
	//所以這些是鏈表元素（裏邊沒有數據，只有next和prev前驅後繼指針，數據部分就是vport結構體中的其他成員）
	struct hlist_node hash_node;
	struct hlist_node dp_hash_node;                          //網橋的hash鏈表元素
	const struct vport_ops *ops;                             //這是端口結構體的操作函數指針結構體，結構體裏邊存放了很多操作函數的函數指針

	struct pcpu_tstats __percpu *percpu_stats;               //vport 只想每個cpu的統計數據使用和維護

	spinlock_t stats_lock;                                   //自旋鎖，防止異步操作，保護下面的兩個成員
	struct vport_err_stats err_stats;   					 //錯誤狀態支出錯誤vport使用和維護的統計數字
	struct ovs_vport_stats offset_stats;					 //添加到實際統計數據，部分原因是爲了兼容
};

/**
 * struct vport_parms - parameters for creating a new vport
 *
 * @name: New vport's name.
 * @type: New vport's type.
 * @options: %OVS_VPORT_ATTR_OPTIONS attribute from Netlink message, %NULL if
 * none was supplied.
 * @dp: New vport's datapath.
 * @port_no: New vport's port number.
 */
struct vport_parms {                                         //端口參數，當創建一個新的vport端口時要傳入的參數
	const char *name;										 //新端口的名字
	enum ovs_vport_type type;								 //新端口的類型，類型不止一種，所以使用枚舉型
	struct nlattr *options;

	/* For ovs_vport_alloc(). */
	struct datapath *dp;									 //新的端口是屬於哪個網橋的
	u16 port_no;											 //新端口的端口號
	u32 upcall_portid;										 //和Netlink通信時使用的端口id
};

/**
 * struct vport_ops - definition of a type of virtual port
 *
 * @type: %OVS_VPORT_TYPE_* value for this type of virtual port.
 * @create: Create a new vport configured as specified.  On success returns
 * a new vport allocated with ovs_vport_alloc(), otherwise an ERR_PTR() value.
 * @destroy: Destroys a vport.  Must call vport_free() on the vport but not
 * before an RCU grace period has elapsed.
 * @set_options: Modify the configuration of an existing vport.  May be %NULL
 * if modification is not supported.
 * @get_options: Appends vport-specific attributes for the configuration of an
 * existing vport to a &struct sk_buff.  May be %NULL for a vport that does not
 * have any configuration.
 * @get_name: Get the device's name.
 * @send: Send a packet on the device.  Returns the length of the packet sent,
 * zero for dropped packets or negative for error.
 */

//這是端口vport操作函數的函數指針結構體，是操作函數的集合，裏面存放了所有有關vport操作函數的函數指針
struct vport_ops {
	enum ovs_vport_type type;								 //端口的類型

	/* Called with ovs_mutex. */
	struct vport *(*create)(const struct vport_parms *);	 //根據指定的參數配置創建一個新的vport，成功返回新端口指針
	void (*destroy)(struct vport *);						 //銷燬端口函數

	int (*set_options)(struct vport *, struct nlattr *);	 //得到和設置option成員函數
	int (*get_options)(const struct vport *, struct sk_buff *);

	/* Called with rcu_read_lock or ovs_mutex. */
	const char *(*get_name)(const struct vport *);

	int (*send)(struct vport *, struct sk_buff *);
};
// 端口vport的類型枚舉類型存儲
enum vport_err_type {
	VPORT_E_RX_DROPPED,
	VPORT_E_RX_ERROR,
	VPORT_E_TX_DROPPED,
	VPORT_E_TX_ERROR,
};

2 網橋模塊

struct datapath {										//網橋結構體
	struct rcu_head rcu;								//RCU調整延遲破壞
	struct list_head list_node;							//網橋hash鏈表元素，裏面只有next和prev前驅後繼指針

	/* Flow table. */
	struct flow_table __rcu *table;						//哈希流表，裏邊包含了哈希桶的地址指針。該hash表受_rcu保護

	/* Switch ports. */
	struct hlist_head *ports;							//一個網橋有多個端口，這些端口都是用哈希鏈表來鏈接的

	/* Stats. */
	struct dp_stats_percpu __percpu *stats_percpu;

#ifdef CONFIG_NET_NS
	/* Network namespace ref. */
	struct net *net;
#endif
};

3 流表模塊flow

struct sw_flow_key {							//隧道相關變量
	struct ovs_key_ipv4_tunnel tun_key;  /* Encapsulating tunnel key. */
	struct {									//包的優先級
		u32	priority;	/* Packet QoS priority. */
		u32	skb_mark;	/* SKB mark. */
		u16	in_port;	/* Input switch port (or DP_MAX_PORTS). */
	} phy;
	struct {
		u8     src[ETH_ALEN];	/* Ethernet source address. */
		u8     dst[ETH_ALEN];	/* Ethernet destination address. */
		__be16 tci;		/* 0 if no VLAN, VLAN_TAG_PRESENT set otherwise. */
		__be16 type;		/* Ethernet frame type. */
	} eth;
	struct {
		u8     proto;		/* IP protocol or lower 8 bits of ARP opcode. */
		u8     tos;		/* IP ToS. */
		u8     ttl;		/* IP TTL/hop limit. */
		u8     frag;		/* One of OVS_FRAG_TYPE_*. */
	} ip;
	union {
		struct {
			struct {
				__be32 src;	/* IP source address. */
				__be32 dst;	/* IP destination address. */
			} addr;
			union {
				struct {
					__be16 src;		/* TCP/UDP/SCTP source port. */
					__be16 dst;		/* TCP/UDP/SCTP destination port. */
				} tp;
				struct {
					u8 sha[ETH_ALEN];	/* ARP source hardware address. */
					u8 tha[ETH_ALEN];	/* ARP target hardware address. */
				} arp;
			};
		} ipv4;
		struct {
			struct {
				struct in6_addr src;	/* IPv6 source address. */
				struct in6_addr dst;	/* IPv6 destination address. */
			} addr;
			__be32 label;			/* IPv6 flow label. */
			struct {
				__be16 src;		/* TCP/UDP/SCTP source port. */
				__be16 dst;		/* TCP/UDP/SCTP destination port. */
			} tp;
			struct {
				struct in6_addr target;	/* ND target address. */
				u8 sll[ETH_ALEN];	/* ND source link layer address. */
				u8 tll[ETH_ALEN];	/* ND target link layer address. */
			} nd;
		} ipv6;
	};