分类: LINUX
2018-01-31 12:14:48
#define M_SIZE 4504
#ifndef MAX_MBUF /* 得到s_mbuf中的数据转换成指定的类型t */ /* 这个宏没有被别的地方调用,用途是将data指定偏移地址o的指针转为类型t */ |
struct sk_buff { /* These two members must be first. */ /* 这两个变量用于形成sk_buff的双链表 */ struct sk_buff *next; struct sk_buff *prev;
/* 数据包到达的时间 */ ktime_t tstamp;
/* 这个sk_buff被哪个sock拥有 */ struct sock *sk; /* 这个sk_buff到达的device或者要从哪个device发送 */ struct net_device *dev;
/* * This is the control buffer. It is free to use for every * layer. Please put your private variables there. If you * want to keep them across layers you have to do a skb_clone() * first. This is owned by whoever has the skb queued ATM. */ char cb[48] __aligned(8);
/* destination entry */ unsigned long _skb_refdst; #ifdef CONFIG_XFRM struct sec_path *sp; #endif /* len为实际数据长度,data_len为数据长度 */ unsigned int len, data_len; /* mac_len:数据链路层地址长度,hdr_len:克隆的skb可写头部的长度 */ __u16 mac_len, hdr_len;
union { __wsum csum; struct { __u16 csum_start; __u16 csum_offset; }; }; /* 包的排队优先级 */ __u32 priority;
kmemcheck_bitfield_begin(flags1); /* 一些标志位: local_df:允许本地分片; nohdr:只能引用其payload */ __u8 local_df:1, cloned:1, ip_summed:2, nohdr:1, nfctinfo:3; __u8 pkt_type:3, fclone:2, ipvs_property:1, peeked:1, nf_trace:1;
kmemcheck_bitfield_end(flags1);
__be16 protocol;
void (*destructor)(struct sk_buff *skb); #if defined(CONFIG_NF_CONNTRACK) ||defined(CONFIG_NF_CONNTRACK_MODULE) struct nf_conntrack *nfct; struct sk_buff *nfct_reasm; #endif #ifdef CONFIG_BRIDGE_NETFILTER struct nf_bridge_info *nf_bridge; #endif
/* 由哪个interface到达的 */ int skb_iif; #ifdef CONFIG_NET_SCHED __u16 tc_index; /* traffic control index */ #ifdef CONFIG_NET_CLS_ACT __u16 tc_verd; /* traffic control verdict */ #endif #endif
__u32 rxhash;
kmemcheck_bitfield_begin(flags2); __u16 queue_mapping:16; #ifdef CONFIG_IPV6_NDISC_NODETYPE __u8 ndisc_nodetype:2, deliver_no_wcard:1; #else __u8 deliver_no_wcard:1; #endif kmemcheck_bitfield_end(flags2);
/* 0/14 bit hole */
#ifdef CONFIG_NET_DMA dma_cookie_t dma_cookie; #endif #ifdef CONFIG_NETWORK_SECMARK __u32 secmark; #endif /* 这个sk_buff被哪个sock拥有 */ union { __u32 mark; __u32 dropcount; }; __u16 vlan_tci;
/* 传输层报头 */ sk_buff_data_t transport_header; /* 网络层报头 */ sk_buff_data_t network_header; /* 链路层报头 */ sk_buff_data_t mac_header;
sk_buff_data_t tail; sk_buff_data_t end; unsigned char *head, *data; unsigned int truesize; atomic_t users; }; |