struct sk_buff_head {
/* These two members must be first. */
struct sk_buff
*next;
struct sk_buff
*prev;
__u32
qlen;
spinlock_t
lock;
};
/**
*
struct sk_buff - socket buffer
*
@next: Next buffer in list
*
@prev: Previous buffer in list
*
@tstamp: Time we arrived/left
*
@rbnode: RB tree node, alternative to next/prev for netem/tcp
*
@sk: Socket we are owned by
*
@dev: Device we arrived on/are leaving by
*
@cb: Control buffer. Free for use by every layer. Put private vars here
*
@_skb_refdst: destination entry (with norefcount bit)
*
@sp: the security path, used for xfrm
*
@len: Length of actual data
*
@data_len: Data length
*
@mac_len: Length of link layer header
*
@hdr_len: writable header length of cloned skb
*
@csum: Checksum (must include start/offset pair)
*
@csum_start: Offset from skb->head where checksumming should start
*
@csum_offset: Offset from csum_start where checksum should be stored
*
@priority: Packet queueing priority
*
@ignore_df: allow local fragmentation
*
@cloned: Head may be cloned (check refcnt to be sure)
*
@ip_summed: Driver fed us an IP checksum
*
@nohdr: Payload reference only, must not modify header
*
@nfctinfo: Relationship of this skb to the connection
*
@pkt_type: Packet class
*
@fclone: skbuff clone status
*
@ipvs_property: skbuff is owned by ipvs
*
@peeked: this packet has been seen already, so stats have been
*
done for it, don't do them again
*
@nf_trace: netfilter packet trace flag
*
@protocol: Packet protocol from driver
*
@destructor: Destruct function
*
@nfct: Associated connection, if any
*
@nf_bridge: Saved data about a bridged frame - see br_netfilter.c
*
@skb_iif: ifindex of device we arrived on
*
@tc_index: Traffic control index
*
@tc_verd: traffic control verdict
*
@hash: the packet hash
*
@queue_mapping: Queue mapping for multiqueue devices
*
@xmit_more: More SKBs are pending for this queue
*
@ndisc_nodetype: router type (from link layer)
*
@ooo_okay: allow the mapping of a socket to a queue to be changed
*
@l4_hash: indicate hash is a canonical 4-tuple hash over transport
*
ports.
*
@sw_hash: indicates hash was computed in software stack
*
@wifi_acked_valid: wifi_acked was set
*
@wifi_acked: whether frame was acked on wifi or not
*
@no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
*
@napi_id: id of the NAPI struct this skb came from
*
@secmark: security marking
*
@mark: Generic packet mark
*
@vlan_proto: vlan encapsulation protocol
*
@vlan_tci: vlan tag control information
*
@inner_protocol: Protocol (encapsulation)
*
@inner_transport_header: Inner transport layer header (encapsulation)
*
@inner_network_header: Network layer header (encapsulation)
*
@inner_mac_header: Link layer header (encapsulation)
*
@transport_header: Transport layer header
*
@network_header: Network layer header
*
@mac_header: Link layer header
*
@tail: Tail pointer
*
@end: End pointer
*
@head: Head of buffer
*
@data: Data head pointer
*
@truesize: Buffer size
*
@users: User count - see {datagram,tcp}.c
*/
struct sk_buff {
union {
struct {
/* These two members must be first. */
struct sk_buff
*next;
struct sk_buff
*prev;
union {
ktime_t
tstamp;
struct skb_mstamp skb_mstamp;
};
};
struct rb_node
rbnode; /* used in netem & tcp stack */
};
struct sock
*sk;
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);
unsigned long
_skb_refdst;
void
(*destructor)(struct sk_buff *skb);
#ifdef CONFIG_XFRM
struct
sec_path
*sp;
#endif
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
struct nf_conntrack
*nfct;
#endif
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
struct nf_bridge_info
*nf_bridge;
#endif
unsigned int
len,
data_len;
__u16
mac_len,
hdr_len;
/* Following fields are _not_ copied in __copy_skb_header()
* Note that queue_mapping is here mostly to fill a hole.
*/
kmemcheck_bitfield_begin(flags1);
__u16
queue_mapping;
/* if you move cloned around you also must adapt those constants */
#ifdef __BIG_ENDIAN_BITFIELD
#define CLONED_MASK
(1 << 7)
#else
#define CLONED_MASK
1
#endif
#define CLONED_OFFSET()
offsetof(struct sk_buff, __cloned_offset)
__u8
__cloned_offset[0];
__u8
cloned:1,
nohdr:1,
fclone:2,
peeked:1,
head_frag:1,
xmit_more:1,
__unused:1; /* one bit hole */
kmemcheck_bitfield_end(flags1);
/* fields enclosed in headers_start/headers_end are copied
* using a single memcpy() in __copy_skb_header()
*/
/* private: */
__u32
headers_start[0];
/* public: */
/* if you move pkt_type around you also must adapt those constants */
#ifdef __BIG_ENDIAN_BITFIELD
#define PKT_TYPE_MAX
(7 << 5)
#else
#define PKT_TYPE_MAX
7
#endif
#define PKT_TYPE_OFFSET()
offsetof(struct sk_buff, __pkt_type_offset)
__u8
__pkt_type_offset[0];
__u8
pkt_type:3;
__u8
pfmemalloc:1;
__u8
ignore_df:1;
__u8
nfctinfo:3;
__u8
nf_trace:1;
__u8
ip_summed:2;
__u8
ooo_okay:1;
__u8
l4_hash:1;
__u8
sw_hash:1;
__u8
wifi_acked_valid:1;
__u8
wifi_acked:1;
__u8
no_fcs:1;
/* Indicates the inner headers are valid in the skbuff. */
__u8
encapsulation:1;
__u8
encap_hdr_csum:1;
__u8
csum_valid:1;
__u8
csum_complete_sw:1;
__u8
csum_level:2;
__u8
csum_bad:1;
#ifdef CONFIG_IPV6_NDISC_NODETYPE
__u8
ndisc_nodetype:2;
#endif
__u8
ipvs_property:1;
__u8
inner_protocol_type:1;
__u8
remcsum_offload:1;
#ifdef CONFIG_NET_SWITCHDEV
__u8
offload_fwd_mark:1;
#endif
/* 2, 4 or 5 bit hole */
#ifdef CONFIG_NET_SCHED
__u16
tc_index;
/* traffic control index */
#ifdef CONFIG_NET_CLS_ACT
__u16
tc_verd;
/* traffic control verdict */
#endif
#endif
union {
__wsum
csum;
struct {
__u16
csum_start;
__u16
csum_offset;
};
};
__u32
priority;
int
skb_iif;
__u32
hash;
__be16
vlan_proto;
__u16
vlan_tci;
#if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
union {
unsigned int
napi_id;
unsigned int
sender_cpu;
};
#endif
#ifdef CONFIG_NETWORK_SECMARK
__u32
secmark;
#endif
union {
__u32
mark;
__u32
reserved_tailroom;
};
union {
__be16
inner_protocol;
__u8
inner_ipproto;
};
__u16
inner_transport_header;
__u16
inner_network_header;
__u16
inner_mac_header;
__be16
protocol;
__u16
transport_header;
__u16
network_header;
__u16
mac_header;
/* private: */
__u32
headers_end[0];
/* public: */
/* These elements must be at the end, see alloc_skb() for details. */
sk_buff_data_t
tail;
sk_buff_data_t
end;
unsigned char
*head,
*data;
unsigned int
truesize;
atomic_t
users;
};
