网络驱动之net_device结构体

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char    name[IFNAMSIZ]; 

char    *ifalias;  //用于SNMP协议

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struct pm_qos_request_list pm_qos_req;

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//网络设备内存映射时在主机中的内存区域 

unsigned long   mem_end; 

unsigned long   mem_start; 

//网络设备I/O基地址 

unsigned long   base_addr; 

//中断号 

unsigned int    irq; 

//传输介质，如双绞线、同轴电缆等，在多端口设备中指定使用哪个端口 

unsigned char   if_port; 

/* if_port可能的取值如下：

enum {

            IF_PORT_UNKNOWN = 0,

        IF_PORT_10BASE2,

        IF_PORT_10BASET,

        IF_PORT_AUI,

        IF_PORT_100BASET,

        IF_PORT_100BASETX,

        IF_PORT_100BASEFX

};

 **/  

// DMA通道 

unsigned char   dma; 

//最大传输单元，以太网数据帧最大为1500字节 

unsigned int    mtu; 

//网络设备硬件类型，如10Mbps以太网ARPHRD_ETHER 

unsigned short  type; 

//硬件数据帧头的长度，以太网为14字节 

unsigned short  hard_header_len; 

//广播地址 

unsigned char   broadcast[MAX_ADDR_LEN]; 

//硬件(如MAC)地址长度以及设备的硬件地址 

unsigned char   addr_len; 

unsigned char   *dev_addr; 

unsigned char   perm_addr[MAX_ADDR_LEN]; 

unsigned char   addr_assign_type;

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int ifindex; //标识网络设备的唯一索引号 

int iflink;  //用于虚拟网络设备 

unsigned short  dev_id; //用于共享网络设备

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unsigned short  needed_headroom; 

unsigned short  needed_tailroom;

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struct device   dev; 

const struct attribute_group *sysfs_groups[4];

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//以设备名为关键字的网络设备哈希链表 

struct hlist_node   name_hlist; 

//网络设备链表 

struct list_head    dev_list; 

//支持NAPI传输的网络设备链表 

struct list_head    napi_list; 

//被注销的网络设备链表 

struct list_head    unreg_list; 

//网络设备硬件地址组成的链表 

struct netdev_hw_addr_list  dev_addrs;  

/* n-tuple filter list attached to this device */ 

struct ethtool_rx_ntuple_list ethtool_ntuple_list; 

//单播地址链表 

struct netdev_hw_addr_list  uc; 

//组播地址链表 

struct netdev_hw_addr_list  mc; 

//防止单播地址链表和组播地址链表被并发访问的自旋锁 

spinlock_t      addr_list_lock; 

//监听所有组播地址 

unsigned int        allmulti; 

//延迟注册/注销的网络设备链表 

struct list_head    todo_list; 

//以索引号为关键字的网络设备哈希链表 

struct hlist_node   index_hlist; 

//链路查看机制链表 

struct list_head    link_watch_list;

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//混杂模式时的单播地址个数 

int     uc_promisc; 

//混杂模式的计数器 

unsigned int    promiscuity;

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struct vlan_group __rcu *vlgrp;     /* VLAN group */ 

void            *dsa_ptr;   /* dsa specific data */ 

void            *atalk_ptr; /* AppleTalk link   */ 

struct in_device __rcu  *ip_ptr;    /* IPv4 specific data   */ 

struct dn_dev __rcu     *dn_ptr;        /* DECnet specific data */ 

struct inet6_dev __rcu  *ip6_ptr;       /* IPv6 specific data */ 

void            *ec_ptr;    /* Econet specific data */ 

void            *ax25_ptr;  /* AX.25 specific data */ 

struct wireless_dev *ieee80211_ptr; /* IEEE 802.11 specific data,

                       assign before registering */

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unsigned long       features; 

    // features的可能取值如下： 

#define NETIF_F_SG      1   /* Scatter/gather IO. */ 

#define NETIF_F_IP_CSUM     2   /* Can checksum TCP/UDP over IPv4. */ 

#define NETIF_F_NO_CSUM     4   /* Does not require checksum. F.e. loopack. */ 

#define NETIF_F_HW_CSUM     8   /* Can checksum all the packets. */ 

#define NETIF_F_IPV6_CSUM   16  /* Can checksum TCP/UDP over IPV6 */ 

#define NETIF_F_HIGHDMA     32  /* Can DMA to high memory. */ 

#define NETIF_F_FRAGLIST    64  /* Scatter/gather IO. */ 

#define NETIF_F_HW_VLAN_TX  128 /* Transmit VLAN hw acceleration */ 

#define NETIF_F_HW_VLAN_RX  256 /* Receive VLAN hw acceleration */ 

#define NETIF_F_HW_VLAN_FILTER  512 /* Receive filtering on VLAN */ 

#define NETIF_F_VLAN_CHALLENGED 1024    /* Device cannot handle VLAN packets */ 

#define NETIF_F_GSO     2048    /* Enable software GSO. */ 

#define NETIF_F_LLTX        4096    /* LockLess TX - deprecated. Please */ 

                    /* do not use LLTX in new drivers */ 

#define NETIF_F_NETNS_LOCAL 8192    /* Does not change network namespaces */ 

#define NETIF_F_GRO     16384   /* Generic receive offload */ 

#define NETIF_F_LRO     32768   /* large receive offload */ 

#define NETIF_F_FCOE_CRC    (1 << 24) /* FCoE CRC32 */ 

#define NETIF_F_SCTP_CSUM   (1 << 25) /* SCTP checksum offload */ 

#define NETIF_F_FCOE_MTU    (1 << 26) /* Supports max FCoE MTU, 2158 bytes*/ 

#define NETIF_F_NTUPLE      (1 << 27) /* N-tuple filters supported */ 

#define NETIF_F_RXHASH      (1 << 28) /* Receive hashing offload */ 

#define NETIF_F_GSO_SHIFT   16 

#define NETIF_F_GSO_MASK    0x00ff0000 

#define NETIF_F_TSO     (SKB_GSO_TCPV4 << NETIF_F_GSO_SHIFT) 

#define NETIF_F_UFO     (SKB_GSO_UDP << NETIF_F_GSO_SHIFT) 

#define NETIF_F_GSO_ROBUST  (SKB_GSO_DODGY << NETIF_F_GSO_SHIFT) 

#define NETIF_F_TSO_ECN     (SKB_GSO_TCP_ECN << NETIF_F_GSO_SHIFT) 

#define NETIF_F_TSO6        (SKB_GSO_TCPV6 << NETIF_F_GSO_SHIFT) 

#define NETIF_F_FSO     (SKB_GSO_FCOE << NETIF_F_GSO_SHIFT) 

#define NETIF_F_GSO_SOFTWARE    (NETIF_F_TSO | NETIF_F_TSO_ECN |  

                 NETIF_F_TSO6 | NETIF_F_UFO) 

#define NETIF_F_GEN_CSUM    (NETIF_F_NO_CSUM | NETIF_F_HW_CSUM) 

#define NETIF_F_V4_CSUM     (NETIF_F_GEN_CSUM | NETIF_F_IP_CSUM) 

#define NETIF_F_V6_CSUM     (NETIF_F_GEN_CSUM | NETIF_F_IPV6_CSUM) 

#define NETIF_F_ALL_CSUM    (NETIF_F_V4_CSUM | NETIF_F_V6_CSUM) 

#define NETIF_F_ONE_FOR_ALL (NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ROBUST |  

                 NETIF_F_SG | NETIF_F_HIGHDMA |      

                 NETIF_F_FRAGLIST)

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unsigned short  padded;

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//NETPOLL相关信息 

struct netpoll_info *npinfo; 

//网络命名空间 

struct net      *nd_net; 

//中间层的私有数据 

union { 

    void                *ml_priv; 

    struct pcpu_lstats __percpu *lstats; /* loopback stats */ 

    struct pcpu_tstats __percpu *tstats; /* tunnel stats */ 

    struct pcpu_dstats __percpu *dstats; /* dummy stats */ 

}; 

//GARP协议相关 

struct garp_port __rcu  *garp_port; 

//虚拟局域网相关 

unsigned long vlan_features; 

//GSO最大值 

unsigned int        gso_max_size; 

//max exchange id for FCoE LRO by ddp 

unsigned int        fcoe_ddp_xid; 

//PHY实例 

struct phy_device *phydev;

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unsigned long       state; 

/* state的可能取值如下：

enum netdev_state_t {

    __LINK_STATE_START,

    __LINK_STATE_PRESENT,

    __LINK_STATE_NOCARRIER,

    __LINK_STATE_LINKWATCH_PENDING,

    __LINK_STATE_DORMANT,

};

**/

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//它们的可能取值定义在linux-2.6.38.8/include/linux/if.h文件中。 

unsigned int        flags; 

unsigned short      gflags; 

unsigned int            priv_flags; //类似flags,但对用户空间不可见

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struct net_device_stats stats; 

//在接收过程中丢弃的数据包数目（在网络驱动中不使用此项） 

atomic_long_t       rx_dropped;

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//RFC 2863操作状态 

unsigned char       operstate; 

/* operstate的可能取值如下：

enum {

    IF_OPER_UNKNOWN,

    IF_OPER_NOTPRESENT,

    IF_OPER_DOWN,

    IF_OPER_LOWERLAYERDOWN,

    IF_OPER_TESTING,

    IF_OPER_DORMANT,

    IF_OPER_UP,

};

 **/  

//映射到RFC2863兼容状态的策略 

unsigned char       link_mode; 

/* link_mode的可能取值如下：

enum {

    IF_LINK_MODE_DEFAULT,

    IF_LINK_MODE_DORMANT,

};

 **/

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//最后接收数据包的时间 

unsigned long       last_rx; 

//最近传送数据包的时间 

unsigned long       trans_start; 

//发生传输超时时，设置的标志 

int         watchdog_timeo; 

//网络层设置的传送数据包超时的时钟   

struct timer_list   watchdog_timer;

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enum { NETREG_UNINITIALIZED=0, 

       NETREG_REGISTERED,   /* completed register_netdevice */ 

       NETREG_UNREGISTERING,    /* called unregister_netdevice */ 

       NETREG_UNREGISTERED, /* completed unregister todo */ 

       NETREG_RELEASED,     /* called free_netdev */ 

       NETREG_DUMMY,        /* dummy device for NAPI poll */ 

} reg_state:16;

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int __percpu        *pcpu_refcnt;

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struct net_device   *master;

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enum { 

    RTNL_LINK_INITIALIZED, 

    RTNL_LINK_INITIALIZING, 

} rtnl_link_state:16;

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//使用无线网络设备扩展功能的一组操作函数 

const struct iw_handler_def *   wireless_handlers; 

//无线网络设备处理函数所使用的数据 

struct iw_public_data * wireless_data; 

//网络设备驱动程序需要实现的一组操作函数 

const struct net_device_ops *netdev_ops; 

//支持ethtool功能的一组操作函数 

const struct ethtool_ops *ethtool_ops; 

//数据链路层协议头相关的一组操作函数 

const struct header_ops *header_ops; 

//析构函数，注销网络设备时被调用 

void (*destructor)(struct net_device *dev); 

//rtnetlink操作函数 

const struct rtnl_link_ops *rtnl_link_ops; 

//DCB操作函数 

const struct dcbnl_rtnl_ops *dcbnl_ops;

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//RPS(Receive Packet Steering)特性 

struct kset     *queues_kset; 

struct netdev_rx_queue  *_rx; 

unsigned int        num_rx_queues; 

unsigned int        real_num_rx_queues; 

rx_handler_func_t __rcu *rx_handler; 

void __rcu      *rx_handler_data; 

struct netdev_queue __rcu *ingress_queue;

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struct netdev_queue *_tx ____cacheline_aligned_in_smp; 

unsigned int        num_tx_queues; 

unsigned int        real_num_tx_queues; 

struct Qdisc        *qdisc; 

unsigned long       tx_queue_len; 

spinlock_t      tx_global_lock; 

//XPS(Transmit Packet Steering)特性 

struct xps_dev_maps __rcu *xps_maps;