Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  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
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
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
131
132
133
134
135
136
137
138
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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
/* SPDX-License-Identifier: GPL-2.0-or-later */

#ifndef _NET_IPV6_GRO_H
#define _NET_IPV6_GRO_H

#include <linux/indirect_call_wrapper.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <net/ip6_checksum.h>
#include <linux/skbuff.h>
#include <net/udp.h>

struct napi_gro_cb {
	union {
		struct {
			/* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */
			void	*frag0;

			/* Length of frag0. */
			unsigned int frag0_len;
		};

		struct {
			/* used in skb_gro_receive() slow path */
			struct sk_buff *last;

			/* jiffies when first packet was created/queued */
			unsigned long age;
		};
	};

	/* This indicates where we are processing relative to skb->data. */
	int	data_offset;

	/* This is non-zero if the packet cannot be merged with the new skb. */
	u16	flush;

	/* Save the IP ID here and check when we get to the transport layer */
	u16	flush_id;

	/* Number of segments aggregated. */
	u16	count;

	/* Used in ipv6_gro_receive() and foo-over-udp and esp-in-udp */
	u16	proto;

/* Used in napi_gro_cb::free */
#define NAPI_GRO_FREE             1
#define NAPI_GRO_FREE_STOLEN_HEAD 2
	/* portion of the cb set to zero at every gro iteration */
	struct_group(zeroed,

		/* Start offset for remote checksum offload */
		u16	gro_remcsum_start;

		/* This is non-zero if the packet may be of the same flow. */
		u8	same_flow:1;

		/* Used in tunnel GRO receive */
		u8	encap_mark:1;

		/* GRO checksum is valid */
		u8	csum_valid:1;

		/* Number of checksums via CHECKSUM_UNNECESSARY */
		u8	csum_cnt:3;

		/* Free the skb? */
		u8	free:2;

		/* Used in foo-over-udp, set in udp[46]_gro_receive */
		u8	is_ipv6:1;

		/* Used in GRE, set in fou/gue_gro_receive */
		u8	is_fou:1;

		/* Used to determine if flush_id can be ignored */
		u8	is_atomic:1;

		/* Number of gro_receive callbacks this packet already went through */
		u8 recursion_counter:4;

		/* GRO is done by frag_list pointer chaining. */
		u8	is_flist:1;
	);

	/* used to support CHECKSUM_COMPLETE for tunneling protocols */
	__wsum	csum;
};

#define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)

#define GRO_RECURSION_LIMIT 15
static inline int gro_recursion_inc_test(struct sk_buff *skb)
{
	return ++NAPI_GRO_CB(skb)->recursion_counter == GRO_RECURSION_LIMIT;
}

typedef struct sk_buff *(*gro_receive_t)(struct list_head *, struct sk_buff *);
static inline struct sk_buff *call_gro_receive(gro_receive_t cb,
					       struct list_head *head,
					       struct sk_buff *skb)
{
	if (unlikely(gro_recursion_inc_test(skb))) {
		NAPI_GRO_CB(skb)->flush |= 1;
		return NULL;
	}

	return cb(head, skb);
}

typedef struct sk_buff *(*gro_receive_sk_t)(struct sock *, struct list_head *,
					    struct sk_buff *);
static inline struct sk_buff *call_gro_receive_sk(gro_receive_sk_t cb,
						  struct sock *sk,
						  struct list_head *head,
						  struct sk_buff *skb)
{
	if (unlikely(gro_recursion_inc_test(skb))) {
		NAPI_GRO_CB(skb)->flush |= 1;
		return NULL;
	}

	return cb(sk, head, skb);
}

static inline unsigned int skb_gro_offset(const struct sk_buff *skb)
{
	return NAPI_GRO_CB(skb)->data_offset;
}

static inline unsigned int skb_gro_len(const struct sk_buff *skb)
{
	return skb->len - NAPI_GRO_CB(skb)->data_offset;
}

static inline void skb_gro_pull(struct sk_buff *skb, unsigned int len)
{
	NAPI_GRO_CB(skb)->data_offset += len;
}

static inline void *skb_gro_header_fast(struct sk_buff *skb,
					unsigned int offset)
{
	return NAPI_GRO_CB(skb)->frag0 + offset;
}

static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen)
{
	return NAPI_GRO_CB(skb)->frag0_len < hlen;
}

static inline void skb_gro_frag0_invalidate(struct sk_buff *skb)
{
	NAPI_GRO_CB(skb)->frag0 = NULL;
	NAPI_GRO_CB(skb)->frag0_len = 0;
}

static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen,
					unsigned int offset)
{
	if (!pskb_may_pull(skb, hlen))
		return NULL;

	skb_gro_frag0_invalidate(skb);
	return skb->data + offset;
}

static inline void *skb_gro_header(struct sk_buff *skb,
					unsigned int hlen, unsigned int offset)
{
	void *ptr;

	ptr = skb_gro_header_fast(skb, offset);
	if (skb_gro_header_hard(skb, hlen))
		ptr = skb_gro_header_slow(skb, hlen, offset);
	return ptr;
}

static inline void *skb_gro_network_header(struct sk_buff *skb)
{
	return (NAPI_GRO_CB(skb)->frag0 ?: skb->data) +
	       skb_network_offset(skb);
}

static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
{
	const struct iphdr *iph = skb_gro_network_header(skb);

	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
				  skb_gro_len(skb), proto, 0);
}

static inline void skb_gro_postpull_rcsum(struct sk_buff *skb,
					const void *start, unsigned int len)
{
	if (NAPI_GRO_CB(skb)->csum_valid)
		NAPI_GRO_CB(skb)->csum = wsum_negate(csum_partial(start, len,
						wsum_negate(NAPI_GRO_CB(skb)->csum)));
}

/* GRO checksum functions. These are logical equivalents of the normal
 * checksum functions (in skbuff.h) except that they operate on the GRO
 * offsets and fields in sk_buff.
 */

__sum16 __skb_gro_checksum_complete(struct sk_buff *skb);

static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb)
{
	return (NAPI_GRO_CB(skb)->gro_remcsum_start == skb_gro_offset(skb));
}

static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,
						      bool zero_okay,
						      __sum16 check)
{
	return ((skb->ip_summed != CHECKSUM_PARTIAL ||
		skb_checksum_start_offset(skb) <
		 skb_gro_offset(skb)) &&
		!skb_at_gro_remcsum_start(skb) &&
		NAPI_GRO_CB(skb)->csum_cnt == 0 &&
		(!zero_okay || check));
}

static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb,
							   __wsum psum)
{
	if (NAPI_GRO_CB(skb)->csum_valid &&
	    !csum_fold(csum_add(psum, NAPI_GRO_CB(skb)->csum)))
		return 0;

	NAPI_GRO_CB(skb)->csum = psum;

	return __skb_gro_checksum_complete(skb);
}

static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
{
	if (NAPI_GRO_CB(skb)->csum_cnt > 0) {
		/* Consume a checksum from CHECKSUM_UNNECESSARY */
		NAPI_GRO_CB(skb)->csum_cnt--;
	} else {
		/* Update skb for CHECKSUM_UNNECESSARY and csum_level when we
		 * verified a new top level checksum or an encapsulated one
		 * during GRO. This saves work if we fallback to normal path.
		 */
		__skb_incr_checksum_unnecessary(skb);
	}
}

#define __skb_gro_checksum_validate(skb, proto, zero_okay, check,	\
				    compute_pseudo)			\
({									\
	__sum16 __ret = 0;						\
	if (__skb_gro_checksum_validate_needed(skb, zero_okay, check))	\
		__ret = __skb_gro_checksum_validate_complete(skb,	\
				compute_pseudo(skb, proto));		\
	if (!__ret)							\
		skb_gro_incr_csum_unnecessary(skb);			\
	__ret;								\
})

#define skb_gro_checksum_validate(skb, proto, compute_pseudo)		\
	__skb_gro_checksum_validate(skb, proto, false, 0, compute_pseudo)

#define skb_gro_checksum_validate_zero_check(skb, proto, check,		\
					     compute_pseudo)		\
	__skb_gro_checksum_validate(skb, proto, true, check, compute_pseudo)

#define skb_gro_checksum_simple_validate(skb)				\
	__skb_gro_checksum_validate(skb, 0, false, 0, null_compute_pseudo)

static inline bool __skb_gro_checksum_convert_check(struct sk_buff *skb)
{
	return (NAPI_GRO_CB(skb)->csum_cnt == 0 &&
		!NAPI_GRO_CB(skb)->csum_valid);
}

static inline void __skb_gro_checksum_convert(struct sk_buff *skb,
					      __wsum pseudo)
{
	NAPI_GRO_CB(skb)->csum = ~pseudo;
	NAPI_GRO_CB(skb)->csum_valid = 1;
}

#define skb_gro_checksum_try_convert(skb, proto, compute_pseudo)	\
do {									\
	if (__skb_gro_checksum_convert_check(skb))			\
		__skb_gro_checksum_convert(skb, 			\
					   compute_pseudo(skb, proto));	\
} while (0)

struct gro_remcsum {
	int offset;
	__wsum delta;
};

static inline void skb_gro_remcsum_init(struct gro_remcsum *grc)
{
	grc->offset = 0;
	grc->delta = 0;
}

static inline void *skb_gro_remcsum_process(struct sk_buff *skb, void *ptr,
					    unsigned int off, size_t hdrlen,
					    int start, int offset,
					    struct gro_remcsum *grc,
					    bool nopartial)
{
	__wsum delta;
	size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start);

	BUG_ON(!NAPI_GRO_CB(skb)->csum_valid);

	if (!nopartial) {
		NAPI_GRO_CB(skb)->gro_remcsum_start = off + hdrlen + start;
		return ptr;
	}

	ptr = skb_gro_header(skb, off + plen, off);
	if (!ptr)
		return NULL;

	delta = remcsum_adjust(ptr + hdrlen, NAPI_GRO_CB(skb)->csum,
			       start, offset);

	/* Adjust skb->csum since we changed the packet */
	NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, delta);

	grc->offset = off + hdrlen + offset;
	grc->delta = delta;

	return ptr;
}

static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb,
					   struct gro_remcsum *grc)
{
	void *ptr;
	size_t plen = grc->offset + sizeof(u16);

	if (!grc->delta)
		return;

	ptr = skb_gro_header(skb, plen, grc->offset);
	if (!ptr)
		return;

	remcsum_unadjust((__sum16 *)ptr, grc->delta);
}

#ifdef CONFIG_XFRM_OFFLOAD
static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
{
	if (PTR_ERR(pp) != -EINPROGRESS)
		NAPI_GRO_CB(skb)->flush |= flush;
}
static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
					       struct sk_buff *pp,
					       int flush,
					       struct gro_remcsum *grc)
{
	if (PTR_ERR(pp) != -EINPROGRESS) {
		NAPI_GRO_CB(skb)->flush |= flush;
		skb_gro_remcsum_cleanup(skb, grc);
		skb->remcsum_offload = 0;
	}
}
#else
static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
{
	NAPI_GRO_CB(skb)->flush |= flush;
}
static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
					       struct sk_buff *pp,
					       int flush,
					       struct gro_remcsum *grc)
{
	NAPI_GRO_CB(skb)->flush |= flush;
	skb_gro_remcsum_cleanup(skb, grc);
	skb->remcsum_offload = 0;
}
#endif

INDIRECT_CALLABLE_DECLARE(struct sk_buff *ipv6_gro_receive(struct list_head *,
							   struct sk_buff *));
INDIRECT_CALLABLE_DECLARE(int ipv6_gro_complete(struct sk_buff *, int));
INDIRECT_CALLABLE_DECLARE(struct sk_buff *inet_gro_receive(struct list_head *,
							   struct sk_buff *));
INDIRECT_CALLABLE_DECLARE(int inet_gro_complete(struct sk_buff *, int));

INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
							   struct sk_buff *));
INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));

INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,
							   struct sk_buff *));
INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));

#define indirect_call_gro_receive_inet(cb, f2, f1, head, skb)	\
({								\
	unlikely(gro_recursion_inc_test(skb)) ?			\
		NAPI_GRO_CB(skb)->flush |= 1, NULL :		\
		INDIRECT_CALL_INET(cb, f2, f1, head, skb);	\
})

struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
				struct udphdr *uh, struct sock *sk);
int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);

static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
{
	struct udphdr *uh;
	unsigned int hlen, off;

	off  = skb_gro_offset(skb);
	hlen = off + sizeof(*uh);
	uh   = skb_gro_header(skb, hlen, off);

	return uh;
}

static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
{
	const struct ipv6hdr *iph = skb_gro_network_header(skb);

	return ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
					    skb_gro_len(skb), proto, 0));
}

int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);

/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
static inline void gro_normal_list(struct napi_struct *napi)
{
	if (!napi->rx_count)
		return;
	netif_receive_skb_list_internal(&napi->rx_list);
	INIT_LIST_HEAD(&napi->rx_list);
	napi->rx_count = 0;
}

/* Queue one GRO_NORMAL SKB up for list processing. If batch size exceeded,
 * pass the whole batch up to the stack.
 */
static inline void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb, int segs)
{
	list_add_tail(&skb->list, &napi->rx_list);
	napi->rx_count += segs;
	if (napi->rx_count >= READ_ONCE(gro_normal_batch))
		gro_normal_list(napi);
}

/* This function is the alternative of 'inet_iif' and 'inet_sdif'
 * functions in case we can not rely on fields of IPCB.
 *
 * The caller must verify skb_valid_dst(skb) is false and skb->dev is initialized.
 * The caller must hold the RCU read lock.
 */
static inline void inet_get_iif_sdif(const struct sk_buff *skb, int *iif, int *sdif)
{
	*iif = inet_iif(skb) ?: skb->dev->ifindex;
	*sdif = 0;

#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
	if (netif_is_l3_slave(skb->dev)) {
		struct net_device *master = netdev_master_upper_dev_get_rcu(skb->dev);

		*sdif = *iif;
		*iif = master ? master->ifindex : 0;
	}
#endif
}

/* This function is the alternative of 'inet6_iif' and 'inet6_sdif'
 * functions in case we can not rely on fields of IP6CB.
 *
 * The caller must verify skb_valid_dst(skb) is false and skb->dev is initialized.
 * The caller must hold the RCU read lock.
 */
static inline void inet6_get_iif_sdif(const struct sk_buff *skb, int *iif, int *sdif)
{
	/* using skb->dev->ifindex because skb_dst(skb) is not initialized */
	*iif = skb->dev->ifindex;
	*sdif = 0;

#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
	if (netif_is_l3_slave(skb->dev)) {
		struct net_device *master = netdev_master_upper_dev_get_rcu(skb->dev);

		*sdif = *iif;
		*iif = master ? master->ifindex : 0;
	}
#endif
}

extern struct list_head offload_base;

#endif /* _NET_IPV6_GRO_H */