skbuff.h 57.0 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
/*
 *	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>
26
#include <linux/textsearch.h>
L
Linus Torvalds 已提交
27
#include <net/checksum.h>
28
#include <linux/rcupdate.h>
29
#include <linux/dmaengine.h>
30
#include <linux/hrtimer.h>
L
Linus Torvalds 已提交
31

32
/* Don't change this without changing skb_csum_unnecessary! */
L
Linus Torvalds 已提交
33
#define CHECKSUM_NONE 0
34 35 36
#define CHECKSUM_UNNECESSARY 1
#define CHECKSUM_COMPLETE 2
#define CHECKSUM_PARTIAL 3
L
Linus Torvalds 已提交
37 38 39

#define SKB_DATA_ALIGN(X)	(((X) + (SMP_CACHE_BYTES - 1)) & \
				 ~(SMP_CACHE_BYTES - 1))
40
#define SKB_WITH_OVERHEAD(X)	\
41
	((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
42 43
#define SKB_MAX_ORDER(X, ORDER) \
	SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
L
Linus Torvalds 已提交
44 45 46 47 48 49 50 51 52 53 54 55 56 57
#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)
 *
58
 *	COMPLETE: the most generic way. Device supplied checksum of _all_
L
Linus Torvalds 已提交
59 60
 *	    the packet as seen by netif_rx in skb->csum.
 *	    NOTE: Even if device supports only some protocols, but
61
 *	    is able to produce some skb->csum, it MUST use COMPLETE,
L
Linus Torvalds 已提交
62 63
 *	    not UNNECESSARY.
 *
64 65 66 67 68 69 70
 *	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.
 *
L
Linus Torvalds 已提交
71 72 73 74
 * B. Checksumming on output.
 *
 *	NONE: skb is checksummed by protocol or csum is not required.
 *
75
 *	PARTIAL: device is required to csum packet as seen by hard_start_xmit
76 77
 *	from skb->csum_start to the end and to record the checksum
 *	at skb->csum_start + skb->csum_offset.
L
Linus Torvalds 已提交
78 79 80 81 82 83 84 85 86 87
 *
 *	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)
88
 *	NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
L
Linus Torvalds 已提交
89 90 91 92 93
 *
 *	Any questions? No questions, good. 		--ANK
 */

struct net_device;
94
struct scatterlist;
J
Jens Axboe 已提交
95
struct pipe_inode_info;
L
Linus Torvalds 已提交
96

97
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
L
Linus Torvalds 已提交
98 99 100
struct nf_conntrack {
	atomic_t use;
};
101
#endif
L
Linus Torvalds 已提交
102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130

#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;
131 132
	__u32 page_offset;
	__u32 size;
L
Linus Torvalds 已提交
133 134
};

135 136 137
#define HAVE_HW_TIME_STAMP

/**
138
 * struct skb_shared_hwtstamps - hardware time stamps
139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165
 * @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;
};

/**
166
 * struct skb_shared_tx - instructions for time stamping of outgoing packets
167 168 169 170
 * @hardware:		generate hardware time stamp
 * @software:		generate software time stamp
 * @in_progress:	device driver is going to provide
 *			hardware time stamp
R
Randy Dunlap 已提交
171
 * @flags:		all shared_tx flags
172 173 174 175 176 177 178 179 180 181 182 183 184
 *
 * 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;
};

L
Linus Torvalds 已提交
185 186 187 188 189
/* 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;
B
Benjamin LaHaise 已提交
190
	unsigned short	nr_frags;
191 192 193 194
	unsigned short	gso_size;
	/* Warning: this field is not always filled in (UFO)! */
	unsigned short	gso_segs;
	unsigned short  gso_type;
A
Al Viro 已提交
195
	__be32          ip6_frag_id;
196
	union skb_shared_tx tx_flags;
197 198 199
#ifdef CONFIG_HAS_DMA
	unsigned int	num_dma_maps;
#endif
L
Linus Torvalds 已提交
200
	struct sk_buff	*frag_list;
201
	struct skb_shared_hwtstamps hwtstamps;
L
Linus Torvalds 已提交
202
	skb_frag_t	frags[MAX_SKB_FRAGS];
203 204 205
#ifdef CONFIG_HAS_DMA
	dma_addr_t	dma_maps[MAX_SKB_FRAGS + 1];
#endif
J
Johann Baudy 已提交
206 207 208
	/* Intermediate layers must ensure that destructor_arg
	 * remains valid until skb destructor */
	void *		destructor_arg;
L
Linus Torvalds 已提交
209 210 211 212
};

/* 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
213 214
 * the entire skb->data.  A clone of a headerless skb holds the length of
 * the header in skb->hdr_len.
L
Linus Torvalds 已提交
215 216 217 218 219 220 221 222 223 224
 *
 * 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)

225 226 227 228 229 230 231

enum {
	SKB_FCLONE_UNAVAILABLE,
	SKB_FCLONE_ORIG,
	SKB_FCLONE_CLONE,
};

232 233
enum {
	SKB_GSO_TCPV4 = 1 << 0,
H
Herbert Xu 已提交
234
	SKB_GSO_UDP = 1 << 1,
235 236 237

	/* This indicates the skb is from an untrusted source. */
	SKB_GSO_DODGY = 1 << 2,
M
Michael Chan 已提交
238 239

	/* This indicates the tcp segment has CWR set. */
H
Herbert Xu 已提交
240 241 242
	SKB_GSO_TCP_ECN = 1 << 3,

	SKB_GSO_TCPV6 = 1 << 4,
243 244

	SKB_GSO_FCOE = 1 << 5,
245 246
};

247 248 249 250 251 252 253 254 255 256
#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

L
Linus Torvalds 已提交
257 258 259 260 261
/** 
 *	struct sk_buff - socket buffer
 *	@next: Next buffer in list
 *	@prev: Previous buffer in list
 *	@sk: Socket we are owned by
H
Herbert Xu 已提交
262
 *	@tstamp: Time we arrived
L
Linus Torvalds 已提交
263
 *	@dev: Device we arrived on/are leaving by
R
Randy Dunlap 已提交
264
 *	@transport_header: Transport layer header
265 266
 *	@network_header: Network layer header
 *	@mac_header: Link layer header
267 268
 *	@dst: destination entry
 *	@sp: the security path, used for xfrm
L
Linus Torvalds 已提交
269 270 271 272
 *	@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
273
 *	@hdr_len: writable header length of cloned skb
274 275 276
 *	@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
277
 *	@local_df: allow local fragmentation
L
Linus Torvalds 已提交
278 279 280
 *	@cloned: Head may be cloned (check refcnt to be sure)
 *	@nohdr: Payload reference only, must not modify header
 *	@pkt_type: Packet class
281
 *	@fclone: skbuff clone status
L
Linus Torvalds 已提交
282 283 284 285 286 287 288 289 290 291
 *	@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
T
Thomas Graf 已提交
292
 *	@mark: Generic packet mark
L
Linus Torvalds 已提交
293
 *	@nfct: Associated connection, if any
294
 *	@ipvs_property: skbuff is owned by ipvs
295 296
 *	@peeked: this packet has been seen already, so stats have been
 *		done for it, don't do them again
297
 *	@nf_trace: netfilter packet trace flag
L
Linus Torvalds 已提交
298
 *	@nfctinfo: Relationship of this skb to the connection
R
Randy Dunlap 已提交
299
 *	@nfct_reasm: netfilter conntrack re-assembly pointer
L
Linus Torvalds 已提交
300
 *	@nf_bridge: Saved data about a bridged frame - see br_netfilter.c
301 302
 *	@iif: ifindex of device we arrived on
 *	@queue_mapping: Queue mapping for multiqueue devices
L
Linus Torvalds 已提交
303 304
 *	@tc_index: Traffic control index
 *	@tc_verd: traffic control verdict
305
 *	@ndisc_nodetype: router type (from link layer)
306
 *	@do_not_encrypt: set to prevent encryption of this frame
S
Sujith 已提交
307 308 309
 *	@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
R
Randy Dunlap 已提交
310 311
 *	@dma_cookie: a cookie to one of several possible DMA operations
 *		done by skb DMA functions
312
 *	@secmark: security marking
313
 *	@vlan_tci: vlan tag control information
L
Linus Torvalds 已提交
314 315 316 317 318 319 320 321
 */

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

	struct sock		*sk;
322
	ktime_t			tstamp;
L
Linus Torvalds 已提交
323 324
	struct net_device	*dev;

325 326
	union {
		struct  dst_entry	*dst;
E
Eric Dumazet 已提交
327
		unsigned long		_skb_dst;
328
	};
329
#ifdef CONFIG_XFRM
L
Linus Torvalds 已提交
330
	struct	sec_path	*sp;
331
#endif
L
Linus Torvalds 已提交
332 333 334 335 336 337
	/*
	 * 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.
	 */
338
	char			cb[48];
L
Linus Torvalds 已提交
339 340

	unsigned int		len,
341 342 343
				data_len;
	__u16			mac_len,
				hdr_len;
A
Al Viro 已提交
344 345
	union {
		__wsum		csum;
346 347 348 349
		struct {
			__u16	csum_start;
			__u16	csum_offset;
		};
A
Al Viro 已提交
350
	};
L
Linus Torvalds 已提交
351
	__u32			priority;
352 353 354
	__u8			local_df:1,
				cloned:1,
				ip_summed:2,
355 356
				nohdr:1,
				nfctinfo:3;
357
	__u8			pkt_type:3,
358
				fclone:2,
359
				ipvs_property:1,
360
				peeked:1,
361
				nf_trace:1;
362
	__be16			protocol;
L
Linus Torvalds 已提交
363 364

	void			(*destructor)(struct sk_buff *skb);
365
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
366
	struct nf_conntrack	*nfct;
367 368
	struct sk_buff		*nfct_reasm;
#endif
L
Linus Torvalds 已提交
369 370 371
#ifdef CONFIG_BRIDGE_NETFILTER
	struct nf_bridge_info	*nf_bridge;
#endif
372 373 374

	int			iif;
	__u16			queue_mapping;
L
Linus Torvalds 已提交
375
#ifdef CONFIG_NET_SCHED
376
	__u16			tc_index;	/* traffic control index */
L
Linus Torvalds 已提交
377
#ifdef CONFIG_NET_CLS_ACT
378
	__u16			tc_verd;	/* traffic control verdict */
L
Linus Torvalds 已提交
379 380
#endif
#endif
381
#ifdef CONFIG_IPV6_NDISC_NODETYPE
382
	__u8			ndisc_nodetype:2;
383
#endif
384 385
#if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
	__u8			do_not_encrypt:1;
S
Sujith 已提交
386
	__u8			requeue:1;
387 388
#endif
	/* 0/13/14 bit hole */
389

390 391 392
#ifdef CONFIG_NET_DMA
	dma_cookie_t		dma_cookie;
#endif
393 394 395
#ifdef CONFIG_NETWORK_SECMARK
	__u32			secmark;
#endif
L
Linus Torvalds 已提交
396

T
Thomas Graf 已提交
397
	__u32			mark;
L
Linus Torvalds 已提交
398

399 400
	__u16			vlan_tci;

401 402 403
	sk_buff_data_t		transport_header;
	sk_buff_data_t		network_header;
	sk_buff_data_t		mac_header;
L
Linus Torvalds 已提交
404
	/* These elements must be at the end, see alloc_skb() for details.  */
405
	sk_buff_data_t		tail;
406
	sk_buff_data_t		end;
L
Linus Torvalds 已提交
407
	unsigned char		*head,
408
				*data;
409 410
	unsigned int		truesize;
	atomic_t		users;
L
Linus Torvalds 已提交
411 412 413 414 415 416 417 418 419 420
};

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

#include <asm/system.h>

421 422 423 424 425 426 427 428
#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

E
Eric Dumazet 已提交
429 430 431 432 433
static inline struct rtable *skb_rtable(const struct sk_buff *skb)
{
	return (struct rtable *)skb->_skb_dst;
}

434
extern void kfree_skb(struct sk_buff *skb);
435
extern void consume_skb(struct sk_buff *skb);
L
Linus Torvalds 已提交
436
extern void	       __kfree_skb(struct sk_buff *skb);
437
extern struct sk_buff *__alloc_skb(unsigned int size,
438
				   gfp_t priority, int fclone, int node);
439
static inline struct sk_buff *alloc_skb(unsigned int size,
A
Al Viro 已提交
440
					gfp_t priority)
441
{
442
	return __alloc_skb(size, priority, 0, -1);
443 444 445
}

static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
A
Al Viro 已提交
446
					       gfp_t priority)
447
{
448
	return __alloc_skb(size, priority, 1, -1);
449 450
}

451 452
extern int skb_recycle_check(struct sk_buff *skb, int skb_size);

H
Herbert Xu 已提交
453
extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
V
Victor Fusco 已提交
454
extern struct sk_buff *skb_clone(struct sk_buff *skb,
A
Al Viro 已提交
455
				 gfp_t priority);
V
Victor Fusco 已提交
456
extern struct sk_buff *skb_copy(const struct sk_buff *skb,
A
Al Viro 已提交
457
				gfp_t priority);
V
Victor Fusco 已提交
458
extern struct sk_buff *pskb_copy(struct sk_buff *skb,
A
Al Viro 已提交
459
				 gfp_t gfp_mask);
L
Linus Torvalds 已提交
460
extern int	       pskb_expand_head(struct sk_buff *skb,
V
Victor Fusco 已提交
461
					int nhead, int ntail,
A
Al Viro 已提交
462
					gfp_t gfp_mask);
L
Linus Torvalds 已提交
463 464 465 466
extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
					    unsigned int headroom);
extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
				       int newheadroom, int newtailroom,
A
Al Viro 已提交
467
				       gfp_t priority);
468 469 470 471 472
extern int	       skb_to_sgvec(struct sk_buff *skb,
				    struct scatterlist *sg, int offset,
				    int len);
extern int	       skb_cow_data(struct sk_buff *skb, int tailbits,
				    struct sk_buff **trailer);
473
extern int	       skb_pad(struct sk_buff *skb, int pad);
474 475
#define dev_kfree_skb(a)	consume_skb(a)
#define dev_consume_skb(a)	kfree_skb_clean(a)
L
Linus Torvalds 已提交
476 477 478 479 480
extern void	      skb_over_panic(struct sk_buff *skb, int len,
				     void *here);
extern void	      skb_under_panic(struct sk_buff *skb, int len,
				      void *here);

481 482 483 484 485
extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
			int getfrag(void *from, char *to, int offset,
			int len,int odd, struct sk_buff *skb),
			void *from, int length);

486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503
struct skb_seq_state
{
	__u32		lower_offset;
	__u32		upper_offset;
	__u32		frag_idx;
	__u32		stepped_offset;
	struct sk_buff	*root_skb;
	struct sk_buff	*cur_skb;
	__u8		*frag_data;
};

extern void	      skb_prepare_seq_read(struct sk_buff *skb,
					   unsigned int from, unsigned int to,
					   struct skb_seq_state *st);
extern unsigned int   skb_seq_read(unsigned int consumed, const u8 **data,
				   struct skb_seq_state *st);
extern void	      skb_abort_seq_read(struct skb_seq_state *st);

504 505 506 507
extern unsigned int   skb_find_text(struct sk_buff *skb, unsigned int from,
				    unsigned int to, struct ts_config *config,
				    struct ts_state *state);

508 509 510 511 512 513 514 515 516 517 518 519
#ifdef NET_SKBUFF_DATA_USES_OFFSET
static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
{
	return skb->head + skb->end;
}
#else
static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
{
	return skb->end;
}
#endif

L
Linus Torvalds 已提交
520
/* Internal */
521
#define skb_shinfo(SKB)	((struct skb_shared_info *)(skb_end_pointer(SKB)))
L
Linus Torvalds 已提交
522

523 524 525 526 527 528 529 530 531 532
static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
{
	return &skb_shinfo(skb)->hwtstamps;
}

static inline union skb_shared_tx *skb_tx(struct sk_buff *skb)
{
	return &skb_shinfo(skb)->tx_flags;
}

L
Linus Torvalds 已提交
533 534 535 536 537 538 539 540 541 542 543
/**
 *	skb_queue_empty - check if a queue is empty
 *	@list: queue head
 *
 *	Returns true if the queue is empty, false otherwise.
 */
static inline int skb_queue_empty(const struct sk_buff_head *list)
{
	return list->next == (struct sk_buff *)list;
}

D
David S. Miller 已提交
544 545 546 547 548 549 550 551 552 553 554 555 556
/**
 *	skb_queue_is_last - check if skb is the last entry in the queue
 *	@list: queue head
 *	@skb: buffer
 *
 *	Returns true if @skb is the last buffer on the list.
 */
static inline bool skb_queue_is_last(const struct sk_buff_head *list,
				     const struct sk_buff *skb)
{
	return (skb->next == (struct sk_buff *) list);
}

557 558 559 560 561 562 563 564 565 566 567 568 569
/**
 *	skb_queue_is_first - check if skb is the first entry in the queue
 *	@list: queue head
 *	@skb: buffer
 *
 *	Returns true if @skb is the first buffer on the list.
 */
static inline bool skb_queue_is_first(const struct sk_buff_head *list,
				      const struct sk_buff *skb)
{
	return (skb->prev == (struct sk_buff *) list);
}

D
David S. Miller 已提交
570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587
/**
 *	skb_queue_next - return the next packet in the queue
 *	@list: queue head
 *	@skb: current buffer
 *
 *	Return the next packet in @list after @skb.  It is only valid to
 *	call this if skb_queue_is_last() evaluates to false.
 */
static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
					     const struct sk_buff *skb)
{
	/* This BUG_ON may seem severe, but if we just return then we
	 * are going to dereference garbage.
	 */
	BUG_ON(skb_queue_is_last(list, skb));
	return skb->next;
}

588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605
/**
 *	skb_queue_prev - return the prev packet in the queue
 *	@list: queue head
 *	@skb: current buffer
 *
 *	Return the prev packet in @list before @skb.  It is only valid to
 *	call this if skb_queue_is_first() evaluates to false.
 */
static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
					     const struct sk_buff *skb)
{
	/* This BUG_ON may seem severe, but if we just return then we
	 * are going to dereference garbage.
	 */
	BUG_ON(skb_queue_is_first(list, skb));
	return skb->prev;
}

L
Linus Torvalds 已提交
606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696
/**
 *	skb_get - reference buffer
 *	@skb: buffer to reference
 *
 *	Makes another reference to a socket buffer and returns a pointer
 *	to the buffer.
 */
static inline struct sk_buff *skb_get(struct sk_buff *skb)
{
	atomic_inc(&skb->users);
	return skb;
}

/*
 * If users == 1, we are the only owner and are can avoid redundant
 * atomic change.
 */

/**
 *	skb_cloned - is the buffer a clone
 *	@skb: buffer to check
 *
 *	Returns true if the buffer was generated with skb_clone() and is
 *	one of multiple shared copies of the buffer. Cloned buffers are
 *	shared data so must not be written to under normal circumstances.
 */
static inline int skb_cloned(const struct sk_buff *skb)
{
	return skb->cloned &&
	       (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
}

/**
 *	skb_header_cloned - is the header a clone
 *	@skb: buffer to check
 *
 *	Returns true if modifying the header part of the buffer requires
 *	the data to be copied.
 */
static inline int skb_header_cloned(const struct sk_buff *skb)
{
	int dataref;

	if (!skb->cloned)
		return 0;

	dataref = atomic_read(&skb_shinfo(skb)->dataref);
	dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
	return dataref != 1;
}

/**
 *	skb_header_release - release reference to header
 *	@skb: buffer to operate on
 *
 *	Drop a reference to the header part of the buffer.  This is done
 *	by acquiring a payload reference.  You must not read from the header
 *	part of skb->data after this.
 */
static inline void skb_header_release(struct sk_buff *skb)
{
	BUG_ON(skb->nohdr);
	skb->nohdr = 1;
	atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
}

/**
 *	skb_shared - is the buffer shared
 *	@skb: buffer to check
 *
 *	Returns true if more than one person has a reference to this
 *	buffer.
 */
static inline int skb_shared(const struct sk_buff *skb)
{
	return atomic_read(&skb->users) != 1;
}

/**
 *	skb_share_check - check if buffer is shared and if so clone it
 *	@skb: buffer to check
 *	@pri: priority for memory allocation
 *
 *	If the buffer is shared the buffer is cloned and the old copy
 *	drops a reference. A new clone with a single reference is returned.
 *	If the buffer is not shared the original buffer is returned. When
 *	being called from interrupt status or with spinlocks held pri must
 *	be GFP_ATOMIC.
 *
 *	NULL is returned on a memory allocation failure.
 */
V
Victor Fusco 已提交
697
static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
A
Al Viro 已提交
698
					      gfp_t pri)
L
Linus Torvalds 已提交
699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728
{
	might_sleep_if(pri & __GFP_WAIT);
	if (skb_shared(skb)) {
		struct sk_buff *nskb = skb_clone(skb, pri);
		kfree_skb(skb);
		skb = nskb;
	}
	return skb;
}

/*
 *	Copy shared buffers into a new sk_buff. We effectively do COW on
 *	packets to handle cases where we have a local reader and forward
 *	and a couple of other messy ones. The normal one is tcpdumping
 *	a packet thats being forwarded.
 */

/**
 *	skb_unshare - make a copy of a shared buffer
 *	@skb: buffer to check
 *	@pri: priority for memory allocation
 *
 *	If the socket buffer is a clone then this function creates a new
 *	copy of the data, drops a reference count on the old copy and returns
 *	the new copy with the reference count at 1. If the buffer is not a clone
 *	the original buffer is returned. When called with a spinlock held or
 *	from interrupt state @pri must be %GFP_ATOMIC
 *
 *	%NULL is returned on a memory allocation failure.
 */
729
static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
A
Al Viro 已提交
730
					  gfp_t pri)
L
Linus Torvalds 已提交
731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793
{
	might_sleep_if(pri & __GFP_WAIT);
	if (skb_cloned(skb)) {
		struct sk_buff *nskb = skb_copy(skb, pri);
		kfree_skb(skb);	/* Free our shared copy */
		skb = nskb;
	}
	return skb;
}

/**
 *	skb_peek
 *	@list_: list to peek at
 *
 *	Peek an &sk_buff. Unlike most other operations you _MUST_
 *	be careful with this one. A peek leaves the buffer on the
 *	list and someone else may run off with it. You must hold
 *	the appropriate locks or have a private queue to do this.
 *
 *	Returns %NULL for an empty list or a pointer to the head element.
 *	The reference count is not incremented and the reference is therefore
 *	volatile. Use with caution.
 */
static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
{
	struct sk_buff *list = ((struct sk_buff *)list_)->next;
	if (list == (struct sk_buff *)list_)
		list = NULL;
	return list;
}

/**
 *	skb_peek_tail
 *	@list_: list to peek at
 *
 *	Peek an &sk_buff. Unlike most other operations you _MUST_
 *	be careful with this one. A peek leaves the buffer on the
 *	list and someone else may run off with it. You must hold
 *	the appropriate locks or have a private queue to do this.
 *
 *	Returns %NULL for an empty list or a pointer to the tail element.
 *	The reference count is not incremented and the reference is therefore
 *	volatile. Use with caution.
 */
static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
{
	struct sk_buff *list = ((struct sk_buff *)list_)->prev;
	if (list == (struct sk_buff *)list_)
		list = NULL;
	return list;
}

/**
 *	skb_queue_len	- get queue length
 *	@list_: list to measure
 *
 *	Return the length of an &sk_buff queue.
 */
static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
{
	return list_->qlen;
}

794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809
/**
 *	__skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
 *	@list: queue to initialize
 *
 *	This initializes only the list and queue length aspects of
 *	an sk_buff_head object.  This allows to initialize the list
 *	aspects of an sk_buff_head without reinitializing things like
 *	the spinlock.  It can also be used for on-stack sk_buff_head
 *	objects where the spinlock is known to not be used.
 */
static inline void __skb_queue_head_init(struct sk_buff_head *list)
{
	list->prev = list->next = (struct sk_buff *)list;
	list->qlen = 0;
}

810 811 812 813 814 815 816 817
/*
 * This function creates a split out lock class for each invocation;
 * this is needed for now since a whole lot of users of the skb-queue
 * infrastructure in drivers have different locking usage (in hardirq)
 * than the networking core (in softirq only). In the long run either the
 * network layer or drivers should need annotation to consolidate the
 * main types of usage into 3 classes.
 */
L
Linus Torvalds 已提交
818 819 820
static inline void skb_queue_head_init(struct sk_buff_head *list)
{
	spin_lock_init(&list->lock);
821
	__skb_queue_head_init(list);
L
Linus Torvalds 已提交
822 823
}

824 825 826 827 828 829 830
static inline void skb_queue_head_init_class(struct sk_buff_head *list,
		struct lock_class_key *class)
{
	skb_queue_head_init(list);
	lockdep_set_class(&list->lock, class);
}

L
Linus Torvalds 已提交
831
/*
832
 *	Insert an sk_buff on a list.
L
Linus Torvalds 已提交
833 834 835 836
 *
 *	The "__skb_xxxx()" functions are the non-atomic ones that
 *	can only be called with interrupts disabled.
 */
837 838 839 840 841 842 843 844 845 846
extern void        skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
static inline void __skb_insert(struct sk_buff *newsk,
				struct sk_buff *prev, struct sk_buff *next,
				struct sk_buff_head *list)
{
	newsk->next = next;
	newsk->prev = prev;
	next->prev  = prev->next = newsk;
	list->qlen++;
}
L
Linus Torvalds 已提交
847

848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871
static inline void __skb_queue_splice(const struct sk_buff_head *list,
				      struct sk_buff *prev,
				      struct sk_buff *next)
{
	struct sk_buff *first = list->next;
	struct sk_buff *last = list->prev;

	first->prev = prev;
	prev->next = first;

	last->next = next;
	next->prev = last;
}

/**
 *	skb_queue_splice - join two skb lists, this is designed for stacks
 *	@list: the new list to add
 *	@head: the place to add it in the first list
 */
static inline void skb_queue_splice(const struct sk_buff_head *list,
				    struct sk_buff_head *head)
{
	if (!skb_queue_empty(list)) {
		__skb_queue_splice(list, (struct sk_buff *) head, head->next);
872
		head->qlen += list->qlen;
873 874 875 876 877 878 879 880 881 882 883 884 885 886 887
	}
}

/**
 *	skb_queue_splice - join two skb lists and reinitialise the emptied list
 *	@list: the new list to add
 *	@head: the place to add it in the first list
 *
 *	The list at @list is reinitialised
 */
static inline void skb_queue_splice_init(struct sk_buff_head *list,
					 struct sk_buff_head *head)
{
	if (!skb_queue_empty(list)) {
		__skb_queue_splice(list, (struct sk_buff *) head, head->next);
888
		head->qlen += list->qlen;
889 890 891 892 893 894 895 896 897 898 899 900 901 902
		__skb_queue_head_init(list);
	}
}

/**
 *	skb_queue_splice_tail - join two skb lists, each list being a queue
 *	@list: the new list to add
 *	@head: the place to add it in the first list
 */
static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
					 struct sk_buff_head *head)
{
	if (!skb_queue_empty(list)) {
		__skb_queue_splice(list, head->prev, (struct sk_buff *) head);
903
		head->qlen += list->qlen;
904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919
	}
}

/**
 *	skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
 *	@list: the new list to add
 *	@head: the place to add it in the first list
 *
 *	Each of the lists is a queue.
 *	The list at @list is reinitialised
 */
static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
					      struct sk_buff_head *head)
{
	if (!skb_queue_empty(list)) {
		__skb_queue_splice(list, head->prev, (struct sk_buff *) head);
920
		head->qlen += list->qlen;
921 922 923 924
		__skb_queue_head_init(list);
	}
}

L
Linus Torvalds 已提交
925
/**
926
 *	__skb_queue_after - queue a buffer at the list head
L
Linus Torvalds 已提交
927
 *	@list: list to use
928
 *	@prev: place after this buffer
L
Linus Torvalds 已提交
929 930
 *	@newsk: buffer to queue
 *
931
 *	Queue a buffer int the middle of a list. This function takes no locks
L
Linus Torvalds 已提交
932 933 934 935
 *	and you must therefore hold required locks before calling it.
 *
 *	A buffer cannot be placed on two lists at the same time.
 */
936 937 938
static inline void __skb_queue_after(struct sk_buff_head *list,
				     struct sk_buff *prev,
				     struct sk_buff *newsk)
L
Linus Torvalds 已提交
939
{
940
	__skb_insert(newsk, prev, prev->next, list);
L
Linus Torvalds 已提交
941 942
}

943 944 945
extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
		       struct sk_buff_head *list);

946 947 948 949 950 951 952
static inline void __skb_queue_before(struct sk_buff_head *list,
				      struct sk_buff *next,
				      struct sk_buff *newsk)
{
	__skb_insert(newsk, next->prev, next, list);
}

953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969
/**
 *	__skb_queue_head - queue a buffer at the list head
 *	@list: list to use
 *	@newsk: buffer to queue
 *
 *	Queue a buffer at the start of a list. This function takes no locks
 *	and you must therefore hold required locks before calling it.
 *
 *	A buffer cannot be placed on two lists at the same time.
 */
extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
static inline void __skb_queue_head(struct sk_buff_head *list,
				    struct sk_buff *newsk)
{
	__skb_queue_after(list, (struct sk_buff *)list, newsk);
}

L
Linus Torvalds 已提交
970 971 972 973 974 975 976 977 978 979 980 981 982 983
/**
 *	__skb_queue_tail - queue a buffer at the list tail
 *	@list: list to use
 *	@newsk: buffer to queue
 *
 *	Queue a buffer at the end of a list. This function takes no locks
 *	and you must therefore hold required locks before calling it.
 *
 *	A buffer cannot be placed on two lists at the same time.
 */
extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
static inline void __skb_queue_tail(struct sk_buff_head *list,
				   struct sk_buff *newsk)
{
984
	__skb_queue_before(list, (struct sk_buff *)list, newsk);
L
Linus Torvalds 已提交
985 986 987 988 989 990
}

/*
 * remove sk_buff from list. _Must_ be called atomically, and with
 * the list known..
 */
D
David S. Miller 已提交
991
extern void	   skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
L
Linus Torvalds 已提交
992 993 994 995 996 997 998 999 1000 1001 1002 1003
static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
{
	struct sk_buff *next, *prev;

	list->qlen--;
	next	   = skb->next;
	prev	   = skb->prev;
	skb->next  = skb->prev = NULL;
	next->prev = prev;
	prev->next = next;
}

1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019
/**
 *	__skb_dequeue - remove from the head of the queue
 *	@list: list to dequeue from
 *
 *	Remove the head of the list. This function does not take any locks
 *	so must be used with appropriate locks held only. The head item is
 *	returned or %NULL if the list is empty.
 */
extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
{
	struct sk_buff *skb = skb_peek(list);
	if (skb)
		__skb_unlink(skb, list);
	return skb;
}
L
Linus Torvalds 已提交
1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068

/**
 *	__skb_dequeue_tail - remove from the tail of the queue
 *	@list: list to dequeue from
 *
 *	Remove the tail of the list. This function does not take any locks
 *	so must be used with appropriate locks held only. The tail item is
 *	returned or %NULL if the list is empty.
 */
extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
{
	struct sk_buff *skb = skb_peek_tail(list);
	if (skb)
		__skb_unlink(skb, list);
	return skb;
}


static inline int skb_is_nonlinear(const struct sk_buff *skb)
{
	return skb->data_len;
}

static inline unsigned int skb_headlen(const struct sk_buff *skb)
{
	return skb->len - skb->data_len;
}

static inline int skb_pagelen(const struct sk_buff *skb)
{
	int i, len = 0;

	for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
		len += skb_shinfo(skb)->frags[i].size;
	return len + skb_headlen(skb);
}

static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
				      struct page *page, int off, int size)
{
	skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

	frag->page		  = page;
	frag->page_offset	  = off;
	frag->size		  = size;
	skb_shinfo(skb)->nr_frags = i + 1;
}

P
Peter Zijlstra 已提交
1069 1070 1071
extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
			    int off, int size);

L
Linus Torvalds 已提交
1072 1073 1074 1075
#define SKB_PAGE_ASSERT(skb) 	BUG_ON(skb_shinfo(skb)->nr_frags)
#define SKB_FRAG_ASSERT(skb) 	BUG_ON(skb_shinfo(skb)->frag_list)
#define SKB_LINEAR_ASSERT(skb)  BUG_ON(skb_is_nonlinear(skb))

1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106
#ifdef NET_SKBUFF_DATA_USES_OFFSET
static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
{
	return skb->head + skb->tail;
}

static inline void skb_reset_tail_pointer(struct sk_buff *skb)
{
	skb->tail = skb->data - skb->head;
}

static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
{
	skb_reset_tail_pointer(skb);
	skb->tail += offset;
}
#else /* NET_SKBUFF_DATA_USES_OFFSET */
static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
{
	return skb->tail;
}

static inline void skb_reset_tail_pointer(struct sk_buff *skb)
{
	skb->tail = skb->data;
}

static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
{
	skb->tail = skb->data + offset;
}
1107

1108 1109
#endif /* NET_SKBUFF_DATA_USES_OFFSET */

L
Linus Torvalds 已提交
1110 1111 1112
/*
 *	Add data to an sk_buff
 */
1113
extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
L
Linus Torvalds 已提交
1114 1115
static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
{
1116
	unsigned char *tmp = skb_tail_pointer(skb);
L
Linus Torvalds 已提交
1117 1118 1119 1120 1121 1122
	SKB_LINEAR_ASSERT(skb);
	skb->tail += len;
	skb->len  += len;
	return tmp;
}

1123
extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
L
Linus Torvalds 已提交
1124 1125 1126 1127 1128 1129 1130
static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
{
	skb->data -= len;
	skb->len  += len;
	return skb->data;
}

1131
extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
L
Linus Torvalds 已提交
1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
{
	skb->len -= len;
	BUG_ON(skb->len < skb->data_len);
	return skb->data += len;
}

extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);

static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
{
	if (len > skb_headlen(skb) &&
G
Gerrit Renker 已提交
1144
	    !__pskb_pull_tail(skb, len - skb_headlen(skb)))
L
Linus Torvalds 已提交
1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160
		return NULL;
	skb->len -= len;
	return skb->data += len;
}

static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
{
	return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
}

static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
{
	if (likely(len <= skb_headlen(skb)))
		return 1;
	if (unlikely(len > skb->len))
		return 0;
G
Gerrit Renker 已提交
1161
	return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
L
Linus Torvalds 已提交
1162 1163 1164 1165 1166 1167 1168 1169
}

/**
 *	skb_headroom - bytes at buffer head
 *	@skb: buffer to check
 *
 *	Return the number of bytes of free space at the head of an &sk_buff.
 */
1170
static inline unsigned int skb_headroom(const struct sk_buff *skb)
L
Linus Torvalds 已提交
1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182
{
	return skb->data - skb->head;
}

/**
 *	skb_tailroom - bytes at buffer end
 *	@skb: buffer to check
 *
 *	Return the number of bytes of free space at the tail of an sk_buff
 */
static inline int skb_tailroom(const struct sk_buff *skb)
{
1183
	return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
L
Linus Torvalds 已提交
1184 1185 1186 1187 1188 1189 1190 1191 1192 1193
}

/**
 *	skb_reserve - adjust headroom
 *	@skb: buffer to alter
 *	@len: bytes to move
 *
 *	Increase the headroom of an empty &sk_buff by reducing the tail
 *	room. This is only allowed for an empty buffer.
 */
1194
static inline void skb_reserve(struct sk_buff *skb, int len)
L
Linus Torvalds 已提交
1195 1196 1197 1198 1199
{
	skb->data += len;
	skb->tail += len;
}

1200
#ifdef NET_SKBUFF_DATA_USES_OFFSET
1201 1202
static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
{
1203
	return skb->head + skb->transport_header;
1204 1205
}

1206 1207
static inline void skb_reset_transport_header(struct sk_buff *skb)
{
1208
	skb->transport_header = skb->data - skb->head;
1209 1210
}

1211 1212 1213
static inline void skb_set_transport_header(struct sk_buff *skb,
					    const int offset)
{
1214 1215
	skb_reset_transport_header(skb);
	skb->transport_header += offset;
1216 1217
}

1218 1219
static inline unsigned char *skb_network_header(const struct sk_buff *skb)
{
1220
	return skb->head + skb->network_header;
1221 1222
}

1223 1224
static inline void skb_reset_network_header(struct sk_buff *skb)
{
1225
	skb->network_header = skb->data - skb->head;
1226 1227
}

1228 1229
static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
{
1230 1231
	skb_reset_network_header(skb);
	skb->network_header += offset;
1232 1233
}

1234
static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1235
{
1236
	return skb->head + skb->mac_header;
1237 1238
}

1239
static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1240
{
1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285
	return skb->mac_header != ~0U;
}

static inline void skb_reset_mac_header(struct sk_buff *skb)
{
	skb->mac_header = skb->data - skb->head;
}

static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
{
	skb_reset_mac_header(skb);
	skb->mac_header += offset;
}

#else /* NET_SKBUFF_DATA_USES_OFFSET */

static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
{
	return skb->transport_header;
}

static inline void skb_reset_transport_header(struct sk_buff *skb)
{
	skb->transport_header = skb->data;
}

static inline void skb_set_transport_header(struct sk_buff *skb,
					    const int offset)
{
	skb->transport_header = skb->data + offset;
}

static inline unsigned char *skb_network_header(const struct sk_buff *skb)
{
	return skb->network_header;
}

static inline void skb_reset_network_header(struct sk_buff *skb)
{
	skb->network_header = skb->data;
}

static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
{
	skb->network_header = skb->data + offset;
1286 1287
}

1288 1289
static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
{
1290
	return skb->mac_header;
1291 1292 1293 1294
}

static inline int skb_mac_header_was_set(const struct sk_buff *skb)
{
1295
	return skb->mac_header != NULL;
1296 1297
}

1298 1299
static inline void skb_reset_mac_header(struct sk_buff *skb)
{
1300
	skb->mac_header = skb->data;
1301 1302
}

1303 1304
static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
{
1305
	skb->mac_header = skb->data + offset;
1306
}
1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
#endif /* NET_SKBUFF_DATA_USES_OFFSET */

static inline int skb_transport_offset(const struct sk_buff *skb)
{
	return skb_transport_header(skb) - skb->data;
}

static inline u32 skb_network_header_len(const struct sk_buff *skb)
{
	return skb->transport_header - skb->network_header;
}

static inline int skb_network_offset(const struct sk_buff *skb)
{
	return skb_network_header(skb) - skb->data;
}
1323

L
Linus Torvalds 已提交
1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347
/*
 * CPUs often take a performance hit when accessing unaligned memory
 * locations. The actual performance hit varies, it can be small if the
 * hardware handles it or large if we have to take an exception and fix it
 * in software.
 *
 * Since an ethernet header is 14 bytes network drivers often end up with
 * the IP header at an unaligned offset. The IP header can be aligned by
 * shifting the start of the packet by 2 bytes. Drivers should do this
 * with:
 *
 * skb_reserve(NET_IP_ALIGN);
 *
 * The downside to this alignment of the IP header is that the DMA is now
 * unaligned. On some architectures the cost of an unaligned DMA is high
 * and this cost outweighs the gains made by aligning the IP header.
 * 
 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
 * to be overridden.
 */
#ifndef NET_IP_ALIGN
#define NET_IP_ALIGN	2
#endif

1348 1349 1350 1351
/*
 * The networking layer reserves some headroom in skb data (via
 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
 * the header has to grow. In the default case, if the header has to grow
1352
 * 32 bytes or less we avoid the reallocation.
1353 1354 1355 1356 1357 1358 1359
 *
 * Unfortunately this headroom changes the DMA alignment of the resulting
 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
 * on some architectures. An architecture can override this value,
 * perhaps setting it to a cacheline in size (since that will maintain
 * cacheline alignment of the DMA). It must be a power of 2.
 *
1360
 * Various parts of the networking layer expect at least 32 bytes of
1361 1362 1363
 * headroom, you should not reduce this.
 */
#ifndef NET_SKB_PAD
1364
#define NET_SKB_PAD	32
1365 1366
#endif

1367
extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
L
Linus Torvalds 已提交
1368 1369 1370

static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
{
1371 1372 1373 1374
	if (unlikely(skb->data_len)) {
		WARN_ON(1);
		return;
	}
1375 1376
	skb->len = len;
	skb_set_tail_pointer(skb, len);
L
Linus Torvalds 已提交
1377 1378
}

1379
extern void skb_trim(struct sk_buff *skb, unsigned int len);
L
Linus Torvalds 已提交
1380 1381 1382

static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
{
1383 1384 1385 1386
	if (skb->data_len)
		return ___pskb_trim(skb, len);
	__skb_trim(skb, len);
	return 0;
L
Linus Torvalds 已提交
1387 1388 1389 1390 1391 1392 1393
}

static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
{
	return (len < skb->len) ? __pskb_trim(skb, len) : 0;
}

1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408
/**
 *	pskb_trim_unique - remove end from a paged unique (not cloned) buffer
 *	@skb: buffer to alter
 *	@len: new length
 *
 *	This is identical to pskb_trim except that the caller knows that
 *	the skb is not cloned so we should never get an error due to out-
 *	of-memory.
 */
static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
{
	int err = pskb_trim(skb, len);
	BUG_ON(err);
}

L
Linus Torvalds 已提交
1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441
/**
 *	skb_orphan - orphan a buffer
 *	@skb: buffer to orphan
 *
 *	If a buffer currently has an owner then we call the owner's
 *	destructor function and make the @skb unowned. The buffer continues
 *	to exist but is no longer charged to its former owner.
 */
static inline void skb_orphan(struct sk_buff *skb)
{
	if (skb->destructor)
		skb->destructor(skb);
	skb->destructor = NULL;
	skb->sk		= NULL;
}

/**
 *	__skb_queue_purge - empty a list
 *	@list: list to empty
 *
 *	Delete all buffers on an &sk_buff list. Each buffer is removed from
 *	the list and one reference dropped. This function does not take the
 *	list lock and the caller must hold the relevant locks to use it.
 */
extern void skb_queue_purge(struct sk_buff_head *list);
static inline void __skb_queue_purge(struct sk_buff_head *list)
{
	struct sk_buff *skb;
	while ((skb = __skb_dequeue(list)) != NULL)
		kfree_skb(skb);
}

/**
1442
 *	__dev_alloc_skb - allocate an skbuff for receiving
L
Linus Torvalds 已提交
1443 1444 1445 1446 1447 1448 1449 1450
 *	@length: length to allocate
 *	@gfp_mask: get_free_pages mask, passed to alloc_skb
 *
 *	Allocate a new &sk_buff and assign it a usage count of one. The
 *	buffer has unspecified headroom built in. Users should allocate
 *	the headroom they think they need without accounting for the
 *	built in space. The built in space is used for optimisations.
 *
1451
 *	%NULL is returned if there is no free memory.
L
Linus Torvalds 已提交
1452 1453
 */
static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
A
Al Viro 已提交
1454
					      gfp_t gfp_mask)
L
Linus Torvalds 已提交
1455
{
1456
	struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
L
Linus Torvalds 已提交
1457
	if (likely(skb))
1458
		skb_reserve(skb, NET_SKB_PAD);
L
Linus Torvalds 已提交
1459 1460 1461
	return skb;
}

1462
extern struct sk_buff *dev_alloc_skb(unsigned int length);
L
Linus Torvalds 已提交
1463

1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485
extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
		unsigned int length, gfp_t gfp_mask);

/**
 *	netdev_alloc_skb - allocate an skbuff for rx on a specific device
 *	@dev: network device to receive on
 *	@length: length to allocate
 *
 *	Allocate a new &sk_buff and assign it a usage count of one. The
 *	buffer has unspecified headroom built in. Users should allocate
 *	the headroom they think they need without accounting for the
 *	built in space. The built in space is used for optimisations.
 *
 *	%NULL is returned if there is no free memory. Although this function
 *	allocates memory it can be called from an interrupt.
 */
static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
		unsigned int length)
{
	return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
}

P
Peter Zijlstra 已提交
1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505
extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask);

/**
 *	netdev_alloc_page - allocate a page for ps-rx on a specific device
 *	@dev: network device to receive on
 *
 * 	Allocate a new page node local to the specified device.
 *
 * 	%NULL is returned if there is no free memory.
 */
static inline struct page *netdev_alloc_page(struct net_device *dev)
{
	return __netdev_alloc_page(dev, GFP_ATOMIC);
}

static inline void netdev_free_page(struct net_device *dev, struct page *page)
{
	__free_page(page);
}

1506 1507 1508 1509 1510 1511 1512 1513
/**
 *	skb_clone_writable - is the header of a clone writable
 *	@skb: buffer to check
 *	@len: length up to which to write
 *
 *	Returns true if modifying the header part of the cloned buffer
 *	does not requires the data to be copied.
 */
1514
static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1515 1516 1517 1518 1519
{
	return !skb_header_cloned(skb) &&
	       skb_headroom(skb) + len <= skb->hdr_len;
}

H
Herbert Xu 已提交
1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535
static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
			    int cloned)
{
	int delta = 0;

	if (headroom < NET_SKB_PAD)
		headroom = NET_SKB_PAD;
	if (headroom > skb_headroom(skb))
		delta = headroom - skb_headroom(skb);

	if (delta || cloned)
		return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
					GFP_ATOMIC);
	return 0;
}

L
Linus Torvalds 已提交
1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549
/**
 *	skb_cow - copy header of skb when it is required
 *	@skb: buffer to cow
 *	@headroom: needed headroom
 *
 *	If the skb passed lacks sufficient headroom or its data part
 *	is shared, data is reallocated. If reallocation fails, an error
 *	is returned and original skb is not changed.
 *
 *	The result is skb with writable area skb->head...skb->tail
 *	and at least @headroom of space at head.
 */
static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
{
H
Herbert Xu 已提交
1550 1551
	return __skb_cow(skb, headroom, skb_cloned(skb));
}
L
Linus Torvalds 已提交
1552

H
Herbert Xu 已提交
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565
/**
 *	skb_cow_head - skb_cow but only making the head writable
 *	@skb: buffer to cow
 *	@headroom: needed headroom
 *
 *	This function is identical to skb_cow except that we replace the
 *	skb_cloned check by skb_header_cloned.  It should be used when
 *	you only need to push on some header and do not need to modify
 *	the data.
 */
static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
{
	return __skb_cow(skb, headroom, skb_header_cloned(skb));
L
Linus Torvalds 已提交
1566 1567 1568 1569 1570 1571 1572 1573 1574
}

/**
 *	skb_padto	- pad an skbuff up to a minimal size
 *	@skb: buffer to pad
 *	@len: minimal length
 *
 *	Pads up a buffer to ensure the trailing bytes exist and are
 *	blanked. If the buffer already contains sufficient data it
1575 1576
 *	is untouched. Otherwise it is extended. Returns zero on
 *	success. The skb is freed on error.
L
Linus Torvalds 已提交
1577 1578
 */
 
1579
static inline int skb_padto(struct sk_buff *skb, unsigned int len)
L
Linus Torvalds 已提交
1580 1581 1582
{
	unsigned int size = skb->len;
	if (likely(size >= len))
1583
		return 0;
G
Gerrit Renker 已提交
1584
	return skb_pad(skb, len - size);
L
Linus Torvalds 已提交
1585 1586 1587 1588 1589 1590 1591 1592 1593
}

static inline int skb_add_data(struct sk_buff *skb,
			       char __user *from, int copy)
{
	const int off = skb->len;

	if (skb->ip_summed == CHECKSUM_NONE) {
		int err = 0;
1594
		__wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
L
Linus Torvalds 已提交
1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618
							    copy, 0, &err);
		if (!err) {
			skb->csum = csum_block_add(skb->csum, csum, off);
			return 0;
		}
	} else if (!copy_from_user(skb_put(skb, copy), from, copy))
		return 0;

	__skb_trim(skb, off);
	return -EFAULT;
}

static inline int skb_can_coalesce(struct sk_buff *skb, int i,
				   struct page *page, int off)
{
	if (i) {
		struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];

		return page == frag->page &&
		       off == frag->page_offset + frag->size;
	}
	return 0;
}

H
Herbert Xu 已提交
1619 1620 1621 1622 1623
static inline int __skb_linearize(struct sk_buff *skb)
{
	return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
}

L
Linus Torvalds 已提交
1624 1625 1626 1627 1628 1629 1630
/**
 *	skb_linearize - convert paged skb to linear one
 *	@skb: buffer to linarize
 *
 *	If there is no free memory -ENOMEM is returned, otherwise zero
 *	is returned and the old skb data released.
 */
H
Herbert Xu 已提交
1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643
static inline int skb_linearize(struct sk_buff *skb)
{
	return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
}

/**
 *	skb_linearize_cow - make sure skb is linear and writable
 *	@skb: buffer to process
 *
 *	If there is no free memory -ENOMEM is returned, otherwise zero
 *	is returned and the old skb data released.
 */
static inline int skb_linearize_cow(struct sk_buff *skb)
L
Linus Torvalds 已提交
1644
{
H
Herbert Xu 已提交
1645 1646
	return skb_is_nonlinear(skb) || skb_cloned(skb) ?
	       __skb_linearize(skb) : 0;
L
Linus Torvalds 已提交
1647 1648 1649 1650 1651 1652 1653 1654 1655
}

/**
 *	skb_postpull_rcsum - update checksum for received skb after pull
 *	@skb: buffer to update
 *	@start: start of data before pull
 *	@len: length of data pulled
 *
 *	After doing a pull on a received packet, you need to call this to
1656 1657
 *	update the CHECKSUM_COMPLETE checksum, or set ip_summed to
 *	CHECKSUM_NONE so that it can be recomputed from scratch.
L
Linus Torvalds 已提交
1658 1659 1660
 */

static inline void skb_postpull_rcsum(struct sk_buff *skb,
1661
				      const void *start, unsigned int len)
L
Linus Torvalds 已提交
1662
{
1663
	if (skb->ip_summed == CHECKSUM_COMPLETE)
L
Linus Torvalds 已提交
1664 1665 1666
		skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
}

1667 1668
unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);

L
Linus Torvalds 已提交
1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
/**
 *	pskb_trim_rcsum - trim received skb and update checksum
 *	@skb: buffer to trim
 *	@len: new length
 *
 *	This is exactly the same as pskb_trim except that it ensures the
 *	checksum of received packets are still valid after the operation.
 */

static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
{
1680
	if (likely(len >= skb->len))
L
Linus Torvalds 已提交
1681
		return 0;
1682
	if (skb->ip_summed == CHECKSUM_COMPLETE)
L
Linus Torvalds 已提交
1683 1684 1685 1686 1687 1688 1689 1690 1691
		skb->ip_summed = CHECKSUM_NONE;
	return __pskb_trim(skb, len);
}

#define skb_queue_walk(queue, skb) \
		for (skb = (queue)->next;					\
		     prefetch(skb->next), (skb != (struct sk_buff *)(queue));	\
		     skb = skb->next)

1692 1693 1694 1695 1696
#define skb_queue_walk_safe(queue, skb, tmp)					\
		for (skb = (queue)->next, tmp = skb->next;			\
		     skb != (struct sk_buff *)(queue);				\
		     skb = tmp, tmp = skb->next)

1697 1698 1699 1700 1701 1702 1703 1704 1705
#define skb_queue_walk_from(queue, skb)						\
		for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue));	\
		     skb = skb->next)

#define skb_queue_walk_from_safe(queue, skb, tmp)				\
		for (tmp = skb->next;						\
		     skb != (struct sk_buff *)(queue);				\
		     skb = tmp, tmp = skb->next)

1706 1707 1708 1709 1710
#define skb_queue_reverse_walk(queue, skb) \
		for (skb = (queue)->prev;					\
		     prefetch(skb->prev), (skb != (struct sk_buff *)(queue));	\
		     skb = skb->prev)

L
Linus Torvalds 已提交
1711

1712 1713
extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
					   int *peeked, int *err);
L
Linus Torvalds 已提交
1714 1715 1716 1717 1718 1719 1720
extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
					 int noblock, int *err);
extern unsigned int    datagram_poll(struct file *file, struct socket *sock,
				     struct poll_table_struct *wait);
extern int	       skb_copy_datagram_iovec(const struct sk_buff *from,
					       int offset, struct iovec *to,
					       int size);
1721
extern int	       skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
L
Linus Torvalds 已提交
1722 1723
							int hlen,
							struct iovec *iov);
1724 1725
extern int	       skb_copy_datagram_from_iovec(struct sk_buff *skb,
						    int offset,
1726 1727
						    const struct iovec *from,
						    int from_offset,
1728
						    int len);
1729 1730 1731 1732 1733
extern int	       skb_copy_datagram_const_iovec(const struct sk_buff *from,
						     int offset,
						     const struct iovec *to,
						     int to_offset,
						     int size);
L
Linus Torvalds 已提交
1734
extern void	       skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1735
extern int	       skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1736
					 unsigned int flags);
1737 1738
extern __wsum	       skb_checksum(const struct sk_buff *skb, int offset,
				    int len, __wsum csum);
L
Linus Torvalds 已提交
1739 1740
extern int	       skb_copy_bits(const struct sk_buff *skb, int offset,
				     void *to, int len);
1741 1742
extern int	       skb_store_bits(struct sk_buff *skb, int offset,
				      const void *from, int len);
1743
extern __wsum	       skb_copy_and_csum_bits(const struct sk_buff *skb,
L
Linus Torvalds 已提交
1744
					      int offset, u8 *to, int len,
1745
					      __wsum csum);
J
Jens Axboe 已提交
1746 1747 1748 1749 1750
extern int             skb_splice_bits(struct sk_buff *skb,
						unsigned int offset,
						struct pipe_inode_info *pipe,
						unsigned int len,
						unsigned int flags);
L
Linus Torvalds 已提交
1751 1752 1753
extern void	       skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
extern void	       skb_split(struct sk_buff *skb,
				 struct sk_buff *skb1, const u32 len);
1754 1755
extern int	       skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
				 int shiftlen);
L
Linus Torvalds 已提交
1756

1757
extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1758

L
Linus Torvalds 已提交
1759 1760 1761 1762 1763
static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
				       int len, void *buffer)
{
	int hlen = skb_headlen(skb);

1764
	if (hlen - offset >= len)
L
Linus Torvalds 已提交
1765 1766 1767 1768 1769 1770 1771 1772
		return skb->data + offset;

	if (skb_copy_bits(skb, offset, buffer, len) < 0)
		return NULL;

	return buffer;
}

1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
					     void *to,
					     const unsigned int len)
{
	memcpy(to, skb->data, len);
}

static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
						    const int offset, void *to,
						    const unsigned int len)
{
	memcpy(to, skb->data + offset, len);
}

1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801
static inline void skb_copy_to_linear_data(struct sk_buff *skb,
					   const void *from,
					   const unsigned int len)
{
	memcpy(skb->data, from, len);
}

static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
						  const int offset,
						  const void *from,
						  const unsigned int len)
{
	memcpy(skb->data + offset, from, len);
}

L
Linus Torvalds 已提交
1802 1803
extern void skb_init(void);

1804 1805 1806 1807 1808
static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
{
	return skb->tstamp;
}

1809 1810 1811 1812 1813 1814 1815 1816 1817
/**
 *	skb_get_timestamp - get timestamp from a skb
 *	@skb: skb to get stamp from
 *	@stamp: pointer to struct timeval to store stamp in
 *
 *	Timestamps are stored in the skb as offsets to a base timestamp.
 *	This function converts the offset back to a struct timeval and stores
 *	it in stamp.
 */
1818 1819
static inline void skb_get_timestamp(const struct sk_buff *skb,
				     struct timeval *stamp)
1820
{
1821
	*stamp = ktime_to_timeval(skb->tstamp);
1822 1823
}

1824 1825 1826 1827 1828 1829
static inline void skb_get_timestampns(const struct sk_buff *skb,
				       struct timespec *stamp)
{
	*stamp = ktime_to_timespec(skb->tstamp);
}

1830
static inline void __net_timestamp(struct sk_buff *skb)
1831
{
1832
	skb->tstamp = ktime_get_real();
1833 1834
}

1835 1836 1837 1838 1839
static inline ktime_t net_timedelta(ktime_t t)
{
	return ktime_sub(ktime_get_real(), t);
}

1840 1841 1842 1843
static inline ktime_t net_invalid_timestamp(void)
{
	return ktime_set(0, 0);
}
1844

1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858
/**
 * skb_tstamp_tx - queue clone of skb with send time stamps
 * @orig_skb:	the original outgoing packet
 * @hwtstamps:	hardware time stamps, may be NULL if not available
 *
 * If the skb has a socket associated, then this function clones the
 * skb (thus sharing the actual data and optional structures), stores
 * the optional hardware time stamping information (if non NULL) or
 * generates a software time stamp (otherwise), then queues the clone
 * to the error queue of the socket.  Errors are silently ignored.
 */
extern void skb_tstamp_tx(struct sk_buff *orig_skb,
			struct skb_shared_hwtstamps *hwtstamps);

1859
extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1860
extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1861

1862 1863 1864 1865 1866
static inline int skb_csum_unnecessary(const struct sk_buff *skb)
{
	return skb->ip_summed & CHECKSUM_UNNECESSARY;
}

1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882
/**
 *	skb_checksum_complete - Calculate checksum of an entire packet
 *	@skb: packet to process
 *
 *	This function calculates the checksum over the entire packet plus
 *	the value of skb->csum.  The latter can be used to supply the
 *	checksum of a pseudo header as used by TCP/UDP.  It returns the
 *	checksum.
 *
 *	For protocols that contain complete checksums such as ICMP/TCP/UDP,
 *	this function can be used to verify that checksum on received
 *	packets.  In that case the function should return zero if the
 *	checksum is correct.  In particular, this function will return zero
 *	if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
 *	hardware has already verified the correctness of the checksum.
 */
1883
static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1884
{
1885 1886
	return skb_csum_unnecessary(skb) ?
	       0 : __skb_checksum_complete(skb);
1887 1888
}

1889
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1890
extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
L
Linus Torvalds 已提交
1891 1892 1893
static inline void nf_conntrack_put(struct nf_conntrack *nfct)
{
	if (nfct && atomic_dec_and_test(&nfct->use))
1894
		nf_conntrack_destroy(nfct);
L
Linus Torvalds 已提交
1895 1896 1897 1898 1899 1900
}
static inline void nf_conntrack_get(struct nf_conntrack *nfct)
{
	if (nfct)
		atomic_inc(&nfct->use);
}
1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911
static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
{
	if (skb)
		atomic_inc(&skb->users);
}
static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
{
	if (skb)
		kfree_skb(skb);
}
#endif
L
Linus Torvalds 已提交
1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923
#ifdef CONFIG_BRIDGE_NETFILTER
static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
{
	if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
		kfree(nf_bridge);
}
static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
{
	if (nf_bridge)
		atomic_inc(&nf_bridge->use);
}
#endif /* CONFIG_BRIDGE_NETFILTER */
1924 1925
static inline void nf_reset(struct sk_buff *skb)
{
1926
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937
	nf_conntrack_put(skb->nfct);
	skb->nfct = NULL;
	nf_conntrack_put_reasm(skb->nfct_reasm);
	skb->nfct_reasm = NULL;
#endif
#ifdef CONFIG_BRIDGE_NETFILTER
	nf_bridge_put(skb->nf_bridge);
	skb->nf_bridge = NULL;
#endif
}

1938 1939 1940
/* Note: This doesn't put any conntrack and bridge info in dst. */
static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
{
1941
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953
	dst->nfct = src->nfct;
	nf_conntrack_get(src->nfct);
	dst->nfctinfo = src->nfctinfo;
	dst->nfct_reasm = src->nfct_reasm;
	nf_conntrack_get_reasm(src->nfct_reasm);
#endif
#ifdef CONFIG_BRIDGE_NETFILTER
	dst->nf_bridge  = src->nf_bridge;
	nf_bridge_get(src->nf_bridge);
#endif
}

1954 1955 1956
static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
{
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1957
	nf_conntrack_put(dst->nfct);
1958 1959 1960 1961 1962 1963 1964 1965
	nf_conntrack_put_reasm(dst->nfct_reasm);
#endif
#ifdef CONFIG_BRIDGE_NETFILTER
	nf_bridge_put(dst->nf_bridge);
#endif
	__nf_copy(dst, src);
}

1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983
#ifdef CONFIG_NETWORK_SECMARK
static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
{
	to->secmark = from->secmark;
}

static inline void skb_init_secmark(struct sk_buff *skb)
{
	skb->secmark = 0;
}
#else
static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
{ }

static inline void skb_init_secmark(struct sk_buff *skb)
{ }
#endif

1984 1985 1986 1987 1988
static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
{
	skb->queue_mapping = queue_mapping;
}

1989
static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
1990 1991 1992 1993
{
	return skb->queue_mapping;
}

1994 1995 1996 1997 1998
static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
{
	to->queue_mapping = from->queue_mapping;
}

1999 2000 2001 2002 2003
static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
{
	skb->queue_mapping = rx_queue + 1;
}

2004
static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2005 2006 2007 2008
{
	return skb->queue_mapping - 1;
}

2009
static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2010 2011 2012 2013
{
	return (skb->queue_mapping != 0);
}

2014 2015 2016
extern u16 skb_tx_hash(const struct net_device *dev,
		       const struct sk_buff *skb);

2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028
#ifdef CONFIG_XFRM
static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
{
	return skb->sp;
}
#else
static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
{
	return NULL;
}
#endif

H
Herbert Xu 已提交
2029 2030 2031 2032 2033
static inline int skb_is_gso(const struct sk_buff *skb)
{
	return skb_shinfo(skb)->gso_size;
}

B
Brice Goglin 已提交
2034 2035 2036 2037 2038
static inline int skb_is_gso_v6(const struct sk_buff *skb)
{
	return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
}

2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052
extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);

static inline bool skb_warn_if_lro(const struct sk_buff *skb)
{
	/* LRO sets gso_size but not gso_type, whereas if GSO is really
	 * wanted then gso_type will be set. */
	struct skb_shared_info *shinfo = skb_shinfo(skb);
	if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
		__skb_warn_lro_forwarding(skb);
		return true;
	}
	return false;
}

2053 2054 2055 2056 2057 2058 2059
static inline void skb_forward_csum(struct sk_buff *skb)
{
	/* Unfortunately we don't support this one.  Any brave souls? */
	if (skb->ip_summed == CHECKSUM_COMPLETE)
		skb->ip_summed = CHECKSUM_NONE;
}

2060
bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
L
Linus Torvalds 已提交
2061 2062
#endif	/* __KERNEL__ */
#endif	/* _LINUX_SKBUFF_H */