[mirror_ubuntu-bionic-kernel.git] / include / linux / skbuff.h

/*
 *	Definitions for the 'struct sk_buff' memory handlers.
 *
 *	Authors:
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *		Florian La Roche, <rzsfl@rz.uni-sb.de>
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#ifndef _LINUX_SKBUFF_H
#define _LINUX_SKBUFF_H

#include <linux/kernel.h>
#include <linux/compiler.h>
#include <linux/time.h>
#include <linux/cache.h>

#include <asm/atomic.h>
#include <asm/types.h>
#include <linux/spinlock.h>
#include <linux/net.h>
#include <linux/textsearch.h>
#include <net/checksum.h>
#include <linux/rcupdate.h>
#include <linux/dmaengine.h>
#include <linux/hrtimer.h>

/* Don't change this without changing skb_csum_unnecessary! */
#define CHECKSUM_NONE 0
#define CHECKSUM_UNNECESSARY 1
#define CHECKSUM_COMPLETE 2
#define CHECKSUM_PARTIAL 3

#define SKB_DATA_ALIGN(X)	(((X) + (SMP_CACHE_BYTES - 1)) & \
				 ~(SMP_CACHE_BYTES - 1))
#define SKB_WITH_OVERHEAD(X)	\
	((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
#define SKB_MAX_ORDER(X, ORDER) \
	SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
#define SKB_MAX_HEAD(X)		(SKB_MAX_ORDER((X), 0))
#define SKB_MAX_ALLOC		(SKB_MAX_ORDER(0, 2))

/* A. Checksumming of received packets by device.
 *
 *	NONE: device failed to checksum this packet.
 *		skb->csum is undefined.
 *
 *	UNNECESSARY: device parsed packet and wouldbe verified checksum.
 *		skb->csum is undefined.
 *	      It is bad option, but, unfortunately, many of vendors do this.
 *	      Apparently with secret goal to sell you new device, when you
 *	      will add new protocol to your host. F.e. IPv6. 8)
 *
 *	COMPLETE: the most generic way. Device supplied checksum of _all_
 *	    the packet as seen by netif_rx in skb->csum.
 *	    NOTE: Even if device supports only some protocols, but
 *	    is able to produce some skb->csum, it MUST use COMPLETE,
 *	    not UNNECESSARY.
 *
 *	PARTIAL: identical to the case for output below.  This may occur
 *	    on a packet received directly from another Linux OS, e.g.,
 *	    a virtualised Linux kernel on the same host.  The packet can
 *	    be treated in the same way as UNNECESSARY except that on
 *	    output (i.e., forwarding) the checksum must be filled in
 *	    by the OS or the hardware.
 *
 * B. Checksumming on output.
 *
 *	NONE: skb is checksummed by protocol or csum is not required.
 *
 *	PARTIAL: device is required to csum packet as seen by hard_start_xmit
 *	from skb->csum_start to the end and to record the checksum
 *	at skb->csum_start + skb->csum_offset.
 *
 *	Device must show its capabilities in dev->features, set
 *	at device setup time.
 *	NETIF_F_HW_CSUM	- it is clever device, it is able to checksum
 *			  everything.
 *	NETIF_F_NO_CSUM - loopback or reliable single hop media.
 *	NETIF_F_IP_CSUM - device is dumb. It is able to csum only
 *			  TCP/UDP over IPv4. Sigh. Vendors like this
 *			  way by an unknown reason. Though, see comment above
 *			  about CHECKSUM_UNNECESSARY. 8)
 *	NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
 *
 *	Any questions? No questions, good. 		--ANK
 */

struct net_device;
struct scatterlist;
struct pipe_inode_info;

#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
struct nf_conntrack {
	atomic_t use;
};
#endif

#ifdef CONFIG_BRIDGE_NETFILTER
struct nf_bridge_info {
	atomic_t use;
	struct net_device *physindev;
	struct net_device *physoutdev;
	unsigned int mask;
	unsigned long data[32 / sizeof(unsigned long)];
};
#endif

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;

/* To allow 64K frame to be packed as single skb without frag_list */
#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)

typedef struct skb_frag_struct skb_frag_t;

struct skb_frag_struct {
	struct page *page;
	__u32 page_offset;
	__u32 size;
};

#define HAVE_HW_TIME_STAMP

/**
 * struct skb_shared_hwtstamps - hardware time stamps
 * @hwtstamp:	hardware time stamp transformed into duration
 *		since arbitrary point in time
 * @syststamp:	hwtstamp transformed to system time base
 *
 * Software time stamps generated by ktime_get_real() are stored in
 * skb->tstamp. The relation between the different kinds of time
 * stamps is as follows:
 *
 * syststamp and tstamp can be compared against each other in
 * arbitrary combinations.  The accuracy of a
 * syststamp/tstamp/"syststamp from other device" comparison is
 * limited by the accuracy of the transformation into system time
 * base. This depends on the device driver and its underlying
 * hardware.
 *
 * hwtstamps can only be compared against other hwtstamps from
 * the same device.
 *
 * This structure is attached to packets as part of the
 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
 */
struct skb_shared_hwtstamps {
	ktime_t	hwtstamp;
	ktime_t	syststamp;
};

/**
 * struct skb_shared_tx - instructions for time stamping of outgoing packets
 * @hardware:		generate hardware time stamp
 * @software:		generate software time stamp
 * @in_progress:	device driver is going to provide
 *			hardware time stamp
 *
 * These flags are attached to packets as part of the
 * &skb_shared_info. Use skb_tx() to get a pointer.
 */
union skb_shared_tx {
	struct {
		__u8	hardware:1,
			software:1,
			in_progress:1;
	};
	__u8 flags;
};

/* This data is invariant across clones and lives at
 * the end of the header data, ie. at skb->end.
 */
struct skb_shared_info {
	atomic_t	dataref;
	unsigned short	nr_frags;
	unsigned short	gso_size;
	/* Warning: this field is not always filled in (UFO)! */
	unsigned short	gso_segs;
	unsigned short  gso_type;
	__be32          ip6_frag_id;
	union skb_shared_tx tx_flags;
#ifdef CONFIG_HAS_DMA
	unsigned int	num_dma_maps;
#endif
	struct sk_buff	*frag_list;
	struct skb_shared_hwtstamps hwtstamps;
	skb_frag_t	frags[MAX_SKB_FRAGS];
#ifdef CONFIG_HAS_DMA
	dma_addr_t	dma_maps[MAX_SKB_FRAGS + 1];
#endif
};

/* We divide dataref into two halves.  The higher 16 bits hold references
 * to the payload part of skb->data.  The lower 16 bits hold references to
 * the entire skb->data.  A clone of a headerless skb holds the length of
 * the header in skb->hdr_len.
 *
 * All users must obey the rule that the skb->data reference count must be
 * greater than or equal to the payload reference count.
 *
 * Holding a reference to the payload part means that the user does not
 * care about modifications to the header part of skb->data.
 */
#define SKB_DATAREF_SHIFT 16
#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)


enum {
	SKB_FCLONE_UNAVAILABLE,
	SKB_FCLONE_ORIG,
	SKB_FCLONE_CLONE,
};

enum {
	SKB_GSO_TCPV4 = 1 << 0,
	SKB_GSO_UDP = 1 << 1,

	/* This indicates the skb is from an untrusted source. */
	SKB_GSO_DODGY = 1 << 2,

	/* This indicates the tcp segment has CWR set. */
	SKB_GSO_TCP_ECN = 1 << 3,

	SKB_GSO_TCPV6 = 1 << 4,
};

#if BITS_PER_LONG > 32
#define NET_SKBUFF_DATA_USES_OFFSET 1
#endif

#ifdef NET_SKBUFF_DATA_USES_OFFSET
typedef unsigned int sk_buff_data_t;
#else
typedef unsigned char *sk_buff_data_t;
#endif

/** 
 *	struct sk_buff - socket buffer
 *	@next: Next buffer in list
 *	@prev: Previous buffer in list
 *	@sk: Socket we are owned by
 *	@tstamp: Time we arrived
 *	@dev: Device we arrived on/are leaving by
 *	@transport_header: Transport layer header
 *	@network_header: Network layer header
 *	@mac_header: Link layer header
 *	@dst: destination entry
 *	@sp: the security path, used for xfrm
 *	@cb: Control buffer. Free for use by every layer. Put private vars here
 *	@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
 *	@local_df: allow local fragmentation
 *	@cloned: Head may be cloned (check refcnt to be sure)
 *	@nohdr: Payload reference only, must not modify header
 *	@pkt_type: Packet class
 *	@fclone: skbuff clone status
 *	@ip_summed: Driver fed us an IP checksum
 *	@priority: Packet queueing priority
 *	@users: User count - see {datagram,tcp}.c
 *	@protocol: Packet protocol from driver
 *	@truesize: Buffer size 
 *	@head: Head of buffer
 *	@data: Data head pointer
 *	@tail: Tail pointer
 *	@end: End pointer
 *	@destructor: Destruct function
 *	@mark: Generic packet mark
 *	@nfct: Associated connection, if any
 *	@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
 *	@nfctinfo: Relationship of this skb to the connection
 *	@nfct_reasm: netfilter conntrack re-assembly pointer
 *	@nf_bridge: Saved data about a bridged frame - see br_netfilter.c
 *	@iif: ifindex of device we arrived on
 *	@queue_mapping: Queue mapping for multiqueue devices
 *	@tc_index: Traffic control index
 *	@tc_verd: traffic control verdict
 *	@ndisc_nodetype: router type (from link layer)
 *	@do_not_encrypt: set to prevent encryption of this frame
 *	@requeue: set to indicate that the wireless core should attempt
 *		a software retry on this frame if we failed to
 *		receive an ACK for it
 *	@dma_cookie: a cookie to one of several possible DMA operations
 *		done by skb DMA functions
 *	@secmark: security marking
 *	@vlan_tci: vlan tag control information
 */

struct sk_buff {
	/* These two members must be first. */
	struct sk_buff		*next;
	struct sk_buff		*prev;

	struct sock		*sk;
	ktime_t			tstamp;
	struct net_device	*dev;

	union {
		struct  dst_entry	*dst;
		struct  rtable		*rtable;
	};
#ifdef CONFIG_XFRM
	struct	sec_path	*sp;
#endif
	/*
	 * 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];

	unsigned int		len,
				data_len;
	__u16			mac_len,
				hdr_len;
	union {
		__wsum		csum;
		struct {
			__u16	csum_start;
			__u16	csum_offset;
		};
	};
	__u32			priority;
	__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;
	__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

	int			iif;
	__u16			queue_mapping;
#ifdef CONFIG_NET_SCHED
	__u16			tc_index;	/* traffic control index */
#ifdef CONFIG_NET_CLS_ACT
	__u16			tc_verd;	/* traffic control verdict */
#endif
#endif
#ifdef CONFIG_IPV6_NDISC_NODETYPE
	__u8			ndisc_nodetype:2;
#endif
#if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
	__u8			do_not_encrypt:1;
	__u8			requeue:1;
#endif
	/* 0/13/14 bit hole */

#ifdef CONFIG_NET_DMA
	dma_cookie_t		dma_cookie;
#endif
#ifdef CONFIG_NETWORK_SECMARK
	__u32			secmark;
#endif

	__u32			mark;

	__u16			vlan_tci;

	sk_buff_data_t		transport_header;
	sk_buff_data_t		network_header;
	sk_buff_data_t		mac_header;
	/* 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;
};

#ifdef __KERNEL__
/*
 *	Handling routines are only of interest to the kernel
 */
#include <linux/slab.h>

#include <asm/system.h>

#ifdef CONFIG_HAS_DMA
#include <linux/dma-mapping.h>
extern int skb_dma_map(struct device *dev, struct sk_buff *skb,
		       enum dma_data_direction dir);
extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
			  enum dma_data_direction dir);
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Definitions for the 'struct sk_buff' memory handlers.
	3	*
	4	* Authors:
	5	* Alan Cox, <gw4pts@gw4pts.ampr.org>
	6	* Florian La Roche, <rzsfl@rz.uni-sb.de>
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* as published by the Free Software Foundation; either version
	11	* 2 of the License, or (at your option) any later version.
	12	*/
	13
	14	#ifndef _LINUX_SKBUFF_H
	15	#define _LINUX_SKBUFF_H
	16
1da177e4 LT	17	#include <linux/kernel.h>
	18	#include <linux/compiler.h>
	19	#include <linux/time.h>
	20	#include <linux/cache.h>
	21
	22	#include <asm/atomic.h>
	23	#include <asm/types.h>
	24	#include <linux/spinlock.h>
1da177e4	25	#include <linux/net.h>
3fc7e8a6	26	#include <linux/textsearch.h>
1da177e4	27	#include <net/checksum.h>
a80958f4	28	#include <linux/rcupdate.h>
97fc2f08	29	#include <linux/dmaengine.h>
b7aa0bf7	30	#include <linux/hrtimer.h>
1da177e4	31
60476372	32	/* Don't change this without changing skb_csum_unnecessary! */
1da177e4	33	#define CHECKSUM_NONE 0
60476372 HX	34	#define CHECKSUM_UNNECESSARY 1
	35	#define CHECKSUM_COMPLETE 2
	36	#define CHECKSUM_PARTIAL 3
1da177e4 LT	37
	38	#define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
	39	~(SMP_CACHE_BYTES - 1))
fc910a27	40	#define SKB_WITH_OVERHEAD(X) \
deea84b0	41	((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
fc910a27 DM	42	#define SKB_MAX_ORDER(X, ORDER) \
fc910a27 DM	43	SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
1da177e4 LT	44	#define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
	45	#define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
	46
	47	/* A. Checksumming of received packets by device.
	48	*
	49	* NONE: device failed to checksum this packet.
	50	* skb->csum is undefined.
	51	*
	52	* UNNECESSARY: device parsed packet and wouldbe verified checksum.
	53	* skb->csum is undefined.
	54	* It is bad option, but, unfortunately, many of vendors do this.
	55	* Apparently with secret goal to sell you new device, when you
	56	* will add new protocol to your host. F.e. IPv6. 8)
	57	*
84fa7933	58	* COMPLETE: the most generic way. Device supplied checksum of _all_
1da177e4 LT	59	* the packet as seen by netif_rx in skb->csum.
1da177e4 LT	60	* NOTE: Even if device supports only some protocols, but
84fa7933	61	* is able to produce some skb->csum, it MUST use COMPLETE,
1da177e4 LT	62	* not UNNECESSARY.
1da177e4 LT	63	*
c6c6e3e0 HX	64	* PARTIAL: identical to the case for output below. This may occur
	65	* on a packet received directly from another Linux OS, e.g.,
	66	* a virtualised Linux kernel on the same host. The packet can
	67	* be treated in the same way as UNNECESSARY except that on
	68	* output (i.e., forwarding) the checksum must be filled in
	69	* by the OS or the hardware.
	70	*
1da177e4 LT	71	* B. Checksumming on output.
	72	*
	73	* NONE: skb is checksummed by protocol or csum is not required.
	74	*
84fa7933	75	* PARTIAL: device is required to csum packet as seen by hard_start_xmit
c6c6e3e0 HX	76	* from skb->csum_start to the end and to record the checksum
c6c6e3e0 HX	77	* at skb->csum_start + skb->csum_offset.
1da177e4 LT	78	*
	79	* Device must show its capabilities in dev->features, set
	80	* at device setup time.
	81	* NETIF_F_HW_CSUM - it is clever device, it is able to checksum
	82	* everything.
	83	* NETIF_F_NO_CSUM - loopback or reliable single hop media.
	84	* NETIF_F_IP_CSUM - device is dumb. It is able to csum only
	85	* TCP/UDP over IPv4. Sigh. Vendors like this
	86	* way by an unknown reason. Though, see comment above
	87	* about CHECKSUM_UNNECESSARY. 8)
c6c6e3e0	88	* NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
1da177e4 LT	89	*
	90	* Any questions? No questions, good. --ANK
	91	*/
	92
1da177e4	93	struct net_device;
716ea3a7	94	struct scatterlist;
9c55e01c	95	struct pipe_inode_info;
1da177e4	96
5f79e0f9	97	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
1da177e4 LT	98	struct nf_conntrack {
1da177e4 LT	99	atomic_t use;
1da177e4	100	};
5f79e0f9	101	#endif
1da177e4 LT	102
	103	#ifdef CONFIG_BRIDGE_NETFILTER
	104	struct nf_bridge_info {
	105	atomic_t use;
	106	struct net_device *physindev;
	107	struct net_device *physoutdev;
1da177e4 LT	108	unsigned int mask;
	109	unsigned long data[32 / sizeof(unsigned long)];
	110	};
	111	#endif
	112
1da177e4 LT	113	struct sk_buff_head {
	114	/* These two members must be first. */
	115	struct sk_buff *next;
	116	struct sk_buff *prev;
	117
	118	__u32 qlen;
	119	spinlock_t lock;
	120	};
	121
	122	struct sk_buff;
	123
	124	/* To allow 64K frame to be packed as single skb without frag_list */
	125	#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
	126
	127	typedef struct skb_frag_struct skb_frag_t;
	128
	129	struct skb_frag_struct {
	130	struct page *page;
a309bb07 DM	131	__u32 page_offset;
a309bb07 DM	132	__u32 size;
1da177e4 LT	133	};
1da177e4 LT	134
ac45f602 PO	135	#define HAVE_HW_TIME_STAMP
	136
	137	/**
d3a21be8	138	* struct skb_shared_hwtstamps - hardware time stamps
ac45f602 PO	139	* @hwtstamp: hardware time stamp transformed into duration
	140	* since arbitrary point in time
	141	* @syststamp: hwtstamp transformed to system time base
	142	*
	143	* Software time stamps generated by ktime_get_real() are stored in
	144	* skb->tstamp. The relation between the different kinds of time
	145	* stamps is as follows:
	146	*
	147	* syststamp and tstamp can be compared against each other in
	148	* arbitrary combinations. The accuracy of a
	149	* syststamp/tstamp/"syststamp from other device" comparison is
	150	* limited by the accuracy of the transformation into system time
	151	* base. This depends on the device driver and its underlying
	152	* hardware.
	153	*
	154	* hwtstamps can only be compared against other hwtstamps from
	155	* the same device.
	156	*
	157	* This structure is attached to packets as part of the
	158	* &skb_shared_info. Use skb_hwtstamps() to get a pointer.
	159	*/
	160	struct skb_shared_hwtstamps {
	161	ktime_t hwtstamp;
	162	ktime_t syststamp;
	163	};
	164
	165	/**
d3a21be8	166	* struct skb_shared_tx - instructions for time stamping of outgoing packets
ac45f602 PO	167	* @hardware: generate hardware time stamp
	168	* @software: generate software time stamp
	169	* @in_progress: device driver is going to provide
	170	* hardware time stamp
	171	*
	172	* These flags are attached to packets as part of the
	173	* &skb_shared_info. Use skb_tx() to get a pointer.
	174	*/
	175	union skb_shared_tx {
	176	struct {
	177	__u8 hardware:1,
	178	software:1,
	179	in_progress:1;
	180	};
	181	__u8 flags;
	182	};
	183
1da177e4 LT	184	/* This data is invariant across clones and lives at
	185	* the end of the header data, ie. at skb->end.
	186	*/
	187	struct skb_shared_info {
	188	atomic_t dataref;
4947d3ef	189	unsigned short nr_frags;
7967168c HX	190	unsigned short gso_size;
	191	/* Warning: this field is not always filled in (UFO)! */
	192	unsigned short gso_segs;
	193	unsigned short gso_type;
ae08e1f0	194	__be32 ip6_frag_id;
ac45f602	195	union skb_shared_tx tx_flags;
271bff7a DM	196	#ifdef CONFIG_HAS_DMA
	197	unsigned int num_dma_maps;
	198	#endif
1da177e4	199	struct sk_buff *frag_list;
ac45f602	200	struct skb_shared_hwtstamps hwtstamps;
1da177e4	201	skb_frag_t frags[MAX_SKB_FRAGS];
271bff7a DM	202	#ifdef CONFIG_HAS_DMA
	203	dma_addr_t dma_maps[MAX_SKB_FRAGS + 1];
	204	#endif
1da177e4 LT	205	};
	206
	207	/* We divide dataref into two halves. The higher 16 bits hold references
	208	* to the payload part of skb->data. The lower 16 bits hold references to
334a8132 PM	209	* the entire skb->data. A clone of a headerless skb holds the length of
334a8132 PM	210	* the header in skb->hdr_len.
1da177e4 LT	211	*
	212	* All users must obey the rule that the skb->data reference count must be
	213	* greater than or equal to the payload reference count.
	214	*
	215	* Holding a reference to the payload part means that the user does not
	216	* care about modifications to the header part of skb->data.
	217	*/
	218	#define SKB_DATAREF_SHIFT 16
	219	#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
	220
d179cd12 DM	221
	222	enum {
	223	SKB_FCLONE_UNAVAILABLE,
	224	SKB_FCLONE_ORIG,
	225	SKB_FCLONE_CLONE,
	226	};
	227
7967168c HX	228	enum {
7967168c HX	229	SKB_GSO_TCPV4 = 1 << 0,
f83ef8c0	230	SKB_GSO_UDP = 1 << 1,
576a30eb HX	231
	232	/* This indicates the skb is from an untrusted source. */
	233	SKB_GSO_DODGY = 1 << 2,
b0da8537 MC	234
b0da8537 MC	235	/* This indicates the tcp segment has CWR set. */
f83ef8c0 HX	236	SKB_GSO_TCP_ECN = 1 << 3,
	237
	238	SKB_GSO_TCPV6 = 1 << 4,
7967168c HX	239	};
7967168c HX	240
2e07fa9c ACM	241	#if BITS_PER_LONG > 32
	242	#define NET_SKBUFF_DATA_USES_OFFSET 1
	243	#endif
	244
	245	#ifdef NET_SKBUFF_DATA_USES_OFFSET
	246	typedef unsigned int sk_buff_data_t;
	247	#else
	248	typedef unsigned char *sk_buff_data_t;
	249	#endif
	250
1da177e4 LT	251	/**
	252	* struct sk_buff - socket buffer
	253	* @next: Next buffer in list
	254	* @prev: Previous buffer in list
1da177e4	255	* @sk: Socket we are owned by
325ed823	256	* @tstamp: Time we arrived
1da177e4	257	* @dev: Device we arrived on/are leaving by
be52178b	258	* @transport_header: Transport layer header
b0e380b1 ACM	259	* @network_header: Network layer header
b0e380b1 ACM	260	* @mac_header: Link layer header
67be2dd1 MW	261	* @dst: destination entry
67be2dd1 MW	262	* @sp: the security path, used for xfrm
1da177e4 LT	263	* @cb: Control buffer. Free for use by every layer. Put private vars here
	264	* @len: Length of actual data
	265	* @data_len: Data length
	266	* @mac_len: Length of link layer header
334a8132	267	* @hdr_len: writable header length of cloned skb
663ead3b HX	268	* @csum: Checksum (must include start/offset pair)
	269	* @csum_start: Offset from skb->head where checksumming should start
	270	* @csum_offset: Offset from csum_start where checksum should be stored
67be2dd1	271	* @local_df: allow local fragmentation
1da177e4 LT	272	* @cloned: Head may be cloned (check refcnt to be sure)
	273	* @nohdr: Payload reference only, must not modify header
	274	* @pkt_type: Packet class
c83c2486	275	* @fclone: skbuff clone status
1da177e4 LT	276	* @ip_summed: Driver fed us an IP checksum
	277	* @priority: Packet queueing priority
	278	* @users: User count - see {datagram,tcp}.c
	279	* @protocol: Packet protocol from driver
1da177e4 LT	280	* @truesize: Buffer size
	281	* @head: Head of buffer
	282	* @data: Data head pointer
	283	* @tail: Tail pointer
	284	* @end: End pointer
	285	* @destructor: Destruct function
82e91ffe	286	* @mark: Generic packet mark
1da177e4	287	* @nfct: Associated connection, if any
c83c2486	288	* @ipvs_property: skbuff is owned by ipvs
31729363 RD	289	* @peeked: this packet has been seen already, so stats have been
31729363 RD	290	* done for it, don't do them again
ba9dda3a	291	* @nf_trace: netfilter packet trace flag
1da177e4	292	* @nfctinfo: Relationship of this skb to the connection
461ddf3b	293	* @nfct_reasm: netfilter conntrack re-assembly pointer
1da177e4	294	* @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
f25f4e44 PWJ	295	* @iif: ifindex of device we arrived on
f25f4e44 PWJ	296	* @queue_mapping: Queue mapping for multiqueue devices
1da177e4 LT	297	* @tc_index: Traffic control index
1da177e4 LT	298	* @tc_verd: traffic control verdict
553a5672	299	* @ndisc_nodetype: router type (from link layer)
4a7b61d2	300	* @do_not_encrypt: set to prevent encryption of this frame
8b30b1fe S	301	* @requeue: set to indicate that the wireless core should attempt
	302	* a software retry on this frame if we failed to
	303	* receive an ACK for it
f4b8ea78 RD	304	* @dma_cookie: a cookie to one of several possible DMA operations
f4b8ea78 RD	305	* done by skb DMA functions
984bc16c	306	* @secmark: security marking
6aa895b0	307	* @vlan_tci: vlan tag control information
1da177e4 LT	308	*/
	309
	310	struct sk_buff {
	311	/* These two members must be first. */
	312	struct sk_buff *next;
	313	struct sk_buff *prev;
	314
1da177e4	315	struct sock *sk;
b7aa0bf7	316	ktime_t tstamp;
1da177e4	317	struct net_device *dev;
1da177e4	318
ee6b9673 ED	319	union {
	320	struct dst_entry *dst;
	321	struct rtable *rtable;
	322	};
def8b4fa	323	#ifdef CONFIG_XFRM
1da177e4	324	struct sec_path *sp;
def8b4fa	325	#endif
1da177e4 LT	326	/*
	327	* This is the control buffer. It is free to use for every
	328	* layer. Please put your private variables there. If you
	329	* want to keep them across layers you have to do a skb_clone()
	330	* first. This is owned by whoever has the skb queued ATM.
	331	*/
3e3850e9	332	char cb[48];
1da177e4 LT	333
1da177e4 LT	334	unsigned int len,
334a8132 PM	335	data_len;
	336	__u16 mac_len,
	337	hdr_len;
ff1dcadb AV	338	union {
ff1dcadb AV	339	__wsum csum;
663ead3b HX	340	struct {
	341	__u16 csum_start;
	342	__u16 csum_offset;
	343	};
ff1dcadb	344	};
1da177e4	345	__u32 priority;
1cbb3380 TG	346	__u8 local_df:1,
	347	cloned:1,
	348	ip_summed:2,
6869c4d8 HW	349	nohdr:1,
6869c4d8 HW	350	nfctinfo:3;
d179cd12	351	__u8 pkt_type:3,
b84f4cc9	352	fclone:2,
ba9dda3a	353	ipvs_property:1,
a59322be	354	peeked:1,
ba9dda3a	355	nf_trace:1;
a0d3bea3	356	__be16 protocol;
1da177e4 LT	357
1da177e4 LT	358	void (destructor)(struct sk_buff skb);
9fb9cbb1	359	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
5f79e0f9	360	struct nf_conntrack *nfct;
9fb9cbb1 YK	361	struct sk_buff *nfct_reasm;
9fb9cbb1 YK	362	#endif
1da177e4 LT	363	#ifdef CONFIG_BRIDGE_NETFILTER
	364	struct nf_bridge_info *nf_bridge;
	365	#endif
f25f4e44 PWJ	366
	367	int iif;
	368	__u16 queue_mapping;
1da177e4	369	#ifdef CONFIG_NET_SCHED
b6b99eb5	370	__u16 tc_index; /* traffic control index */
1da177e4	371	#ifdef CONFIG_NET_CLS_ACT
b6b99eb5	372	__u16 tc_verd; /* traffic control verdict */
1da177e4	373	#endif
1da177e4	374	#endif
de357cc0	375	#ifdef CONFIG_IPV6_NDISC_NODETYPE
fadf6bf0	376	__u8 ndisc_nodetype:2;
de357cc0	377	#endif
d0f09804 JB	378	#if defined(CONFIG_MAC80211) \|\| defined(CONFIG_MAC80211_MODULE)
d0f09804 JB	379	__u8 do_not_encrypt:1;
8b30b1fe	380	__u8 requeue:1;
d0f09804 JB	381	#endif
d0f09804 JB	382	/* 0/13/14 bit hole */
f25f4e44	383
97fc2f08 CL	384	#ifdef CONFIG_NET_DMA
	385	dma_cookie_t dma_cookie;
	386	#endif
984bc16c JM	387	#ifdef CONFIG_NETWORK_SECMARK
	388	__u32 secmark;
	389	#endif
1da177e4	390
82e91ffe	391	__u32 mark;
1da177e4	392
6aa895b0 PM	393	__u16 vlan_tci;
6aa895b0 PM	394
27a884dc ACM	395	sk_buff_data_t transport_header;
	396	sk_buff_data_t network_header;
	397	sk_buff_data_t mac_header;
1da177e4	398	/* These elements must be at the end, see alloc_skb() for details. */
27a884dc	399	sk_buff_data_t tail;
4305b541	400	sk_buff_data_t end;
1da177e4	401	unsigned char *head,
4305b541	402	*data;
27a884dc ACM	403	unsigned int truesize;
27a884dc ACM	404	atomic_t users;
1da177e4 LT	405	};
	406
	407	#ifdef __KERNEL__
	408	/*
	409	* Handling routines are only of interest to the kernel
	410	*/
	411	#include <linux/slab.h>
	412
	413	#include <asm/system.h>
	414
a40c24a1 DM	415	#ifdef CONFIG_HAS_DMA
	416	#include <linux/dma-mapping.h>
	417	extern int skb_dma_map(struct device dev, struct sk_buff skb,
	418	enum dma_data_direction dir);
	419	extern void skb_dma_unmap(struct device dev, struct sk_buff skb,
	420	enum dma_data_direction dir);
	421	#endif
	422