OVS端口模块的重要数据结构3

1 端口模块

struct vport {
struct rcu_head rcu;                                     //一种锁机制
struct datapath	*dp;                                     //网桥结构体指针，表示该端口属于哪个网桥的
u32 upcall_portid;	                                     //Netlink端口收到的数据包时使用的端口id
u16 port_no;                                             //端口号，唯一标识该端口

// 因为一个网桥上有多个端口，而这些端口都是用哈希链表来存储的。
//所以这些是链表元素（里边没有数据，只有next和prev前驱后继指针，数据部分就是vport结构体中的其他成员）
struct hlist_node hash_node;
struct hlist_node dp_hash_node;                          //网桥的hash链表元素
const struct vport_ops *ops;                             //这是端口结构体的操作函数指针结构体，结构体里边存放了很多操作函数的函数指针

struct pcpu_tstats __percpu *percpu_stats;               //vport 只想每个cpu的统计数据使用和维护

spinlock_t stats_lock;                                   //自旋锁，防止异步操作，保护下面的两个成员
struct vport_err_stats err_stats;   					 //错误状态支出错误vport使用和维护的统计数字
struct ovs_vport_stats offset_stats;					 //添加到实际统计数据，部分原因是为了兼容
};

/**
* 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 {                                         //端口参数，当创建一个新的vport端口时要传入的参数
const char *name;										 //新端口的名字
enum ovs_vport_type type;								 //新端口的类型，类型不止一种，所以使用枚举型
struct nlattr *options;

/* For ovs_vport_alloc(). */
struct datapath *dp;									 //新的端口是属于哪个网桥的
u16 port_no;											 //新端口的端口号
u32 upcall_portid;										 //和Netlink通信时使用的端口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.
*/

//这是端口vport操作函数的函数指针结构体，是操作函数的集合，里面存放了所有有关vport操作函数的函数指针
struct vport_ops {
enum ovs_vport_type type;								 //端口的类型

/* Called with ovs_mutex. */
struct vport *(*create)(const struct vport_parms *);	 //根据指定的参数配置创建一个新的vport，成功返回新端口指针
void (*destroy)(struct vport *);						 //销毁端口函数

int (*set_options)(struct vport *, struct nlattr *);	 //得到和设置option成员函数
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的类型枚举类型存储
enum vport_err_type {
VPORT_E_RX_DROPPED,
VPORT_E_RX_ERROR,
VPORT_E_TX_DROPPED,
VPORT_E_TX_ERROR,
};

2 网桥模块

struct datapath {										//网桥结构体
struct rcu_head rcu;								//RCU调整延迟破坏
struct list_head list_node;							//网桥hash链表元素，里面只有next和prev前驱后继指针

/* Flow table. */
struct flow_table __rcu *table;						//哈希流表，里边包含了哈希桶的地址指针。该hash表受_rcu保护

/* Switch ports. */
struct hlist_head *ports;							//一个网桥有多个端口，这些端口都是用哈希链表来链接的

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

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

3 流表模块flow

struct sw_flow_key {							//隧道相关变量
struct ovs_key_ipv4_tunnel tun_key;  /* Encapsulating tunnel key. */
struct {									//包的优先级
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;
};