xref: /linux/net/packet/af_packet.c (revision 83439a0f1ce6a592f95e41338320b5f01b98a356)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		PACKET - implements raw packet sockets.
8  *
9  * Authors:	Ross Biro
10  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11  *		Alan Cox, <gw4pts@gw4pts.ampr.org>
12  *
13  * Fixes:
14  *		Alan Cox	:	verify_area() now used correctly
15  *		Alan Cox	:	new skbuff lists, look ma no backlogs!
16  *		Alan Cox	:	tidied skbuff lists.
17  *		Alan Cox	:	Now uses generic datagram routines I
18  *					added. Also fixed the peek/read crash
19  *					from all old Linux datagram code.
20  *		Alan Cox	:	Uses the improved datagram code.
21  *		Alan Cox	:	Added NULL's for socket options.
22  *		Alan Cox	:	Re-commented the code.
23  *		Alan Cox	:	Use new kernel side addressing
24  *		Rob Janssen	:	Correct MTU usage.
25  *		Dave Platt	:	Counter leaks caused by incorrect
26  *					interrupt locking and some slightly
27  *					dubious gcc output. Can you read
28  *					compiler: it said _VOLATILE_
29  *	Richard Kooijman	:	Timestamp fixes.
30  *		Alan Cox	:	New buffers. Use sk->mac.raw.
31  *		Alan Cox	:	sendmsg/recvmsg support.
32  *		Alan Cox	:	Protocol setting support
33  *	Alexey Kuznetsov	:	Untied from IPv4 stack.
34  *	Cyrus Durgin		:	Fixed kerneld for kmod.
35  *	Michal Ostrowski        :       Module initialization cleanup.
36  *         Ulises Alonso        :       Frame number limit removal and
37  *                                      packet_set_ring memory leak.
38  *		Eric Biederman	:	Allow for > 8 byte hardware addresses.
39  *					The convention is that longer addresses
40  *					will simply extend the hardware address
41  *					byte arrays at the end of sockaddr_ll
42  *					and packet_mreq.
43  *		Johann Baudy	:	Added TX RING.
44  *		Chetan Loke	:	Implemented TPACKET_V3 block abstraction
45  *					layer.
46  *					Copyright (C) 2011, <lokec@ccs.neu.edu>
47  */
48 
49 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
50 
51 #include <linux/ethtool.h>
52 #include <linux/filter.h>
53 #include <linux/types.h>
54 #include <linux/mm.h>
55 #include <linux/capability.h>
56 #include <linux/fcntl.h>
57 #include <linux/socket.h>
58 #include <linux/in.h>
59 #include <linux/inet.h>
60 #include <linux/netdevice.h>
61 #include <linux/if_packet.h>
62 #include <linux/wireless.h>
63 #include <linux/kernel.h>
64 #include <linux/kmod.h>
65 #include <linux/slab.h>
66 #include <linux/vmalloc.h>
67 #include <net/net_namespace.h>
68 #include <net/ip.h>
69 #include <net/protocol.h>
70 #include <linux/skbuff.h>
71 #include <net/sock.h>
72 #include <linux/errno.h>
73 #include <linux/timer.h>
74 #include <linux/uaccess.h>
75 #include <asm/ioctls.h>
76 #include <asm/page.h>
77 #include <asm/cacheflush.h>
78 #include <asm/io.h>
79 #include <linux/proc_fs.h>
80 #include <linux/seq_file.h>
81 #include <linux/poll.h>
82 #include <linux/module.h>
83 #include <linux/init.h>
84 #include <linux/mutex.h>
85 #include <linux/if_vlan.h>
86 #include <linux/virtio_net.h>
87 #include <linux/errqueue.h>
88 #include <linux/net_tstamp.h>
89 #include <linux/percpu.h>
90 #ifdef CONFIG_INET
91 #include <net/inet_common.h>
92 #endif
93 #include <linux/bpf.h>
94 #include <net/compat.h>
95 #include <linux/netfilter_netdev.h>
96 
97 #include "internal.h"
98 
99 /*
100    Assumptions:
101    - If the device has no dev->header_ops->create, there is no LL header
102      visible above the device. In this case, its hard_header_len should be 0.
103      The device may prepend its own header internally. In this case, its
104      needed_headroom should be set to the space needed for it to add its
105      internal header.
106      For example, a WiFi driver pretending to be an Ethernet driver should
107      set its hard_header_len to be the Ethernet header length, and set its
108      needed_headroom to be (the real WiFi header length - the fake Ethernet
109      header length).
110    - packet socket receives packets with pulled ll header,
111      so that SOCK_RAW should push it back.
112 
113 On receive:
114 -----------
115 
116 Incoming, dev_has_header(dev) == true
117    mac_header -> ll header
118    data       -> data
119 
120 Outgoing, dev_has_header(dev) == true
121    mac_header -> ll header
122    data       -> ll header
123 
124 Incoming, dev_has_header(dev) == false
125    mac_header -> data
126      However drivers often make it point to the ll header.
127      This is incorrect because the ll header should be invisible to us.
128    data       -> data
129 
130 Outgoing, dev_has_header(dev) == false
131    mac_header -> data. ll header is invisible to us.
132    data       -> data
133 
134 Resume
135   If dev_has_header(dev) == false we are unable to restore the ll header,
136     because it is invisible to us.
137 
138 
139 On transmit:
140 ------------
141 
142 dev_has_header(dev) == true
143    mac_header -> ll header
144    data       -> ll header
145 
146 dev_has_header(dev) == false (ll header is invisible to us)
147    mac_header -> data
148    data       -> data
149 
150    We should set network_header on output to the correct position,
151    packet classifier depends on it.
152  */
153 
154 /* Private packet socket structures. */
155 
156 /* identical to struct packet_mreq except it has
157  * a longer address field.
158  */
159 struct packet_mreq_max {
160 	int		mr_ifindex;
161 	unsigned short	mr_type;
162 	unsigned short	mr_alen;
163 	unsigned char	mr_address[MAX_ADDR_LEN];
164 };
165 
166 union tpacket_uhdr {
167 	struct tpacket_hdr  *h1;
168 	struct tpacket2_hdr *h2;
169 	struct tpacket3_hdr *h3;
170 	void *raw;
171 };
172 
173 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
174 		int closing, int tx_ring);
175 
176 #define V3_ALIGNMENT	(8)
177 
178 #define BLK_HDR_LEN	(ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
179 
180 #define BLK_PLUS_PRIV(sz_of_priv) \
181 	(BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
182 
183 #define BLOCK_STATUS(x)	((x)->hdr.bh1.block_status)
184 #define BLOCK_NUM_PKTS(x)	((x)->hdr.bh1.num_pkts)
185 #define BLOCK_O2FP(x)		((x)->hdr.bh1.offset_to_first_pkt)
186 #define BLOCK_LEN(x)		((x)->hdr.bh1.blk_len)
187 #define BLOCK_SNUM(x)		((x)->hdr.bh1.seq_num)
188 #define BLOCK_O2PRIV(x)	((x)->offset_to_priv)
189 
190 struct packet_sock;
191 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
192 		       struct packet_type *pt, struct net_device *orig_dev);
193 
194 static void *packet_previous_frame(struct packet_sock *po,
195 		struct packet_ring_buffer *rb,
196 		int status);
197 static void packet_increment_head(struct packet_ring_buffer *buff);
198 static int prb_curr_blk_in_use(struct tpacket_block_desc *);
199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
200 			struct packet_sock *);
201 static void prb_retire_current_block(struct tpacket_kbdq_core *,
202 		struct packet_sock *, unsigned int status);
203 static int prb_queue_frozen(struct tpacket_kbdq_core *);
204 static void prb_open_block(struct tpacket_kbdq_core *,
205 		struct tpacket_block_desc *);
206 static void prb_retire_rx_blk_timer_expired(struct timer_list *);
207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
208 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
209 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
210 		struct tpacket3_hdr *);
211 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
212 		struct tpacket3_hdr *);
213 static void packet_flush_mclist(struct sock *sk);
214 static u16 packet_pick_tx_queue(struct sk_buff *skb);
215 
216 struct packet_skb_cb {
217 	union {
218 		struct sockaddr_pkt pkt;
219 		union {
220 			/* Trick: alias skb original length with
221 			 * ll.sll_family and ll.protocol in order
222 			 * to save room.
223 			 */
224 			unsigned int origlen;
225 			struct sockaddr_ll ll;
226 		};
227 	} sa;
228 };
229 
230 #define vio_le() virtio_legacy_is_little_endian()
231 
232 #define PACKET_SKB_CB(__skb)	((struct packet_skb_cb *)((__skb)->cb))
233 
234 #define GET_PBDQC_FROM_RB(x)	((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
235 #define GET_PBLOCK_DESC(x, bid)	\
236 	((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
237 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)	\
238 	((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
239 #define GET_NEXT_PRB_BLK_NUM(x) \
240 	(((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
241 	((x)->kactive_blk_num+1) : 0)
242 
243 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
244 static void __fanout_link(struct sock *sk, struct packet_sock *po);
245 
246 #ifdef CONFIG_NETFILTER_EGRESS
247 static noinline struct sk_buff *nf_hook_direct_egress(struct sk_buff *skb)
248 {
249 	struct sk_buff *next, *head = NULL, *tail;
250 	int rc;
251 
252 	rcu_read_lock();
253 	for (; skb != NULL; skb = next) {
254 		next = skb->next;
255 		skb_mark_not_on_list(skb);
256 
257 		if (!nf_hook_egress(skb, &rc, skb->dev))
258 			continue;
259 
260 		if (!head)
261 			head = skb;
262 		else
263 			tail->next = skb;
264 
265 		tail = skb;
266 	}
267 	rcu_read_unlock();
268 
269 	return head;
270 }
271 #endif
272 
273 static int packet_direct_xmit(struct sk_buff *skb)
274 {
275 #ifdef CONFIG_NETFILTER_EGRESS
276 	if (nf_hook_egress_active()) {
277 		skb = nf_hook_direct_egress(skb);
278 		if (!skb)
279 			return NET_XMIT_DROP;
280 	}
281 #endif
282 	return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
283 }
284 
285 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
286 {
287 	struct net_device *dev;
288 
289 	rcu_read_lock();
290 	dev = rcu_dereference(po->cached_dev);
291 	dev_hold(dev);
292 	rcu_read_unlock();
293 
294 	return dev;
295 }
296 
297 static void packet_cached_dev_assign(struct packet_sock *po,
298 				     struct net_device *dev)
299 {
300 	rcu_assign_pointer(po->cached_dev, dev);
301 }
302 
303 static void packet_cached_dev_reset(struct packet_sock *po)
304 {
305 	RCU_INIT_POINTER(po->cached_dev, NULL);
306 }
307 
308 static bool packet_use_direct_xmit(const struct packet_sock *po)
309 {
310 	return po->xmit == packet_direct_xmit;
311 }
312 
313 static u16 packet_pick_tx_queue(struct sk_buff *skb)
314 {
315 	struct net_device *dev = skb->dev;
316 	const struct net_device_ops *ops = dev->netdev_ops;
317 	int cpu = raw_smp_processor_id();
318 	u16 queue_index;
319 
320 #ifdef CONFIG_XPS
321 	skb->sender_cpu = cpu + 1;
322 #endif
323 	skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
324 	if (ops->ndo_select_queue) {
325 		queue_index = ops->ndo_select_queue(dev, skb, NULL);
326 		queue_index = netdev_cap_txqueue(dev, queue_index);
327 	} else {
328 		queue_index = netdev_pick_tx(dev, skb, NULL);
329 	}
330 
331 	return queue_index;
332 }
333 
334 /* __register_prot_hook must be invoked through register_prot_hook
335  * or from a context in which asynchronous accesses to the packet
336  * socket is not possible (packet_create()).
337  */
338 static void __register_prot_hook(struct sock *sk)
339 {
340 	struct packet_sock *po = pkt_sk(sk);
341 
342 	if (!po->running) {
343 		if (po->fanout)
344 			__fanout_link(sk, po);
345 		else
346 			dev_add_pack(&po->prot_hook);
347 
348 		sock_hold(sk);
349 		po->running = 1;
350 	}
351 }
352 
353 static void register_prot_hook(struct sock *sk)
354 {
355 	lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
356 	__register_prot_hook(sk);
357 }
358 
359 /* If the sync parameter is true, we will temporarily drop
360  * the po->bind_lock and do a synchronize_net to make sure no
361  * asynchronous packet processing paths still refer to the elements
362  * of po->prot_hook.  If the sync parameter is false, it is the
363  * callers responsibility to take care of this.
364  */
365 static void __unregister_prot_hook(struct sock *sk, bool sync)
366 {
367 	struct packet_sock *po = pkt_sk(sk);
368 
369 	lockdep_assert_held_once(&po->bind_lock);
370 
371 	po->running = 0;
372 
373 	if (po->fanout)
374 		__fanout_unlink(sk, po);
375 	else
376 		__dev_remove_pack(&po->prot_hook);
377 
378 	__sock_put(sk);
379 
380 	if (sync) {
381 		spin_unlock(&po->bind_lock);
382 		synchronize_net();
383 		spin_lock(&po->bind_lock);
384 	}
385 }
386 
387 static void unregister_prot_hook(struct sock *sk, bool sync)
388 {
389 	struct packet_sock *po = pkt_sk(sk);
390 
391 	if (po->running)
392 		__unregister_prot_hook(sk, sync);
393 }
394 
395 static inline struct page * __pure pgv_to_page(void *addr)
396 {
397 	if (is_vmalloc_addr(addr))
398 		return vmalloc_to_page(addr);
399 	return virt_to_page(addr);
400 }
401 
402 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
403 {
404 	union tpacket_uhdr h;
405 
406 	h.raw = frame;
407 	switch (po->tp_version) {
408 	case TPACKET_V1:
409 		h.h1->tp_status = status;
410 		flush_dcache_page(pgv_to_page(&h.h1->tp_status));
411 		break;
412 	case TPACKET_V2:
413 		h.h2->tp_status = status;
414 		flush_dcache_page(pgv_to_page(&h.h2->tp_status));
415 		break;
416 	case TPACKET_V3:
417 		h.h3->tp_status = status;
418 		flush_dcache_page(pgv_to_page(&h.h3->tp_status));
419 		break;
420 	default:
421 		WARN(1, "TPACKET version not supported.\n");
422 		BUG();
423 	}
424 
425 	smp_wmb();
426 }
427 
428 static int __packet_get_status(const struct packet_sock *po, void *frame)
429 {
430 	union tpacket_uhdr h;
431 
432 	smp_rmb();
433 
434 	h.raw = frame;
435 	switch (po->tp_version) {
436 	case TPACKET_V1:
437 		flush_dcache_page(pgv_to_page(&h.h1->tp_status));
438 		return h.h1->tp_status;
439 	case TPACKET_V2:
440 		flush_dcache_page(pgv_to_page(&h.h2->tp_status));
441 		return h.h2->tp_status;
442 	case TPACKET_V3:
443 		flush_dcache_page(pgv_to_page(&h.h3->tp_status));
444 		return h.h3->tp_status;
445 	default:
446 		WARN(1, "TPACKET version not supported.\n");
447 		BUG();
448 		return 0;
449 	}
450 }
451 
452 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts,
453 				   unsigned int flags)
454 {
455 	struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
456 
457 	if (shhwtstamps &&
458 	    (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
459 	    ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts))
460 		return TP_STATUS_TS_RAW_HARDWARE;
461 
462 	if ((flags & SOF_TIMESTAMPING_SOFTWARE) &&
463 	    ktime_to_timespec64_cond(skb_tstamp(skb), ts))
464 		return TP_STATUS_TS_SOFTWARE;
465 
466 	return 0;
467 }
468 
469 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
470 				    struct sk_buff *skb)
471 {
472 	union tpacket_uhdr h;
473 	struct timespec64 ts;
474 	__u32 ts_status;
475 
476 	if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
477 		return 0;
478 
479 	h.raw = frame;
480 	/*
481 	 * versions 1 through 3 overflow the timestamps in y2106, since they
482 	 * all store the seconds in a 32-bit unsigned integer.
483 	 * If we create a version 4, that should have a 64-bit timestamp,
484 	 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit
485 	 * nanoseconds.
486 	 */
487 	switch (po->tp_version) {
488 	case TPACKET_V1:
489 		h.h1->tp_sec = ts.tv_sec;
490 		h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
491 		break;
492 	case TPACKET_V2:
493 		h.h2->tp_sec = ts.tv_sec;
494 		h.h2->tp_nsec = ts.tv_nsec;
495 		break;
496 	case TPACKET_V3:
497 		h.h3->tp_sec = ts.tv_sec;
498 		h.h3->tp_nsec = ts.tv_nsec;
499 		break;
500 	default:
501 		WARN(1, "TPACKET version not supported.\n");
502 		BUG();
503 	}
504 
505 	/* one flush is safe, as both fields always lie on the same cacheline */
506 	flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
507 	smp_wmb();
508 
509 	return ts_status;
510 }
511 
512 static void *packet_lookup_frame(const struct packet_sock *po,
513 				 const struct packet_ring_buffer *rb,
514 				 unsigned int position,
515 				 int status)
516 {
517 	unsigned int pg_vec_pos, frame_offset;
518 	union tpacket_uhdr h;
519 
520 	pg_vec_pos = position / rb->frames_per_block;
521 	frame_offset = position % rb->frames_per_block;
522 
523 	h.raw = rb->pg_vec[pg_vec_pos].buffer +
524 		(frame_offset * rb->frame_size);
525 
526 	if (status != __packet_get_status(po, h.raw))
527 		return NULL;
528 
529 	return h.raw;
530 }
531 
532 static void *packet_current_frame(struct packet_sock *po,
533 		struct packet_ring_buffer *rb,
534 		int status)
535 {
536 	return packet_lookup_frame(po, rb, rb->head, status);
537 }
538 
539 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
540 {
541 	del_timer_sync(&pkc->retire_blk_timer);
542 }
543 
544 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
545 		struct sk_buff_head *rb_queue)
546 {
547 	struct tpacket_kbdq_core *pkc;
548 
549 	pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
550 
551 	spin_lock_bh(&rb_queue->lock);
552 	pkc->delete_blk_timer = 1;
553 	spin_unlock_bh(&rb_queue->lock);
554 
555 	prb_del_retire_blk_timer(pkc);
556 }
557 
558 static void prb_setup_retire_blk_timer(struct packet_sock *po)
559 {
560 	struct tpacket_kbdq_core *pkc;
561 
562 	pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
563 	timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
564 		    0);
565 	pkc->retire_blk_timer.expires = jiffies;
566 }
567 
568 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
569 				int blk_size_in_bytes)
570 {
571 	struct net_device *dev;
572 	unsigned int mbits, div;
573 	struct ethtool_link_ksettings ecmd;
574 	int err;
575 
576 	rtnl_lock();
577 	dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
578 	if (unlikely(!dev)) {
579 		rtnl_unlock();
580 		return DEFAULT_PRB_RETIRE_TOV;
581 	}
582 	err = __ethtool_get_link_ksettings(dev, &ecmd);
583 	rtnl_unlock();
584 	if (err)
585 		return DEFAULT_PRB_RETIRE_TOV;
586 
587 	/* If the link speed is so slow you don't really
588 	 * need to worry about perf anyways
589 	 */
590 	if (ecmd.base.speed < SPEED_1000 ||
591 	    ecmd.base.speed == SPEED_UNKNOWN)
592 		return DEFAULT_PRB_RETIRE_TOV;
593 
594 	div = ecmd.base.speed / 1000;
595 	mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
596 
597 	if (div)
598 		mbits /= div;
599 
600 	if (div)
601 		return mbits + 1;
602 	return mbits;
603 }
604 
605 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
606 			union tpacket_req_u *req_u)
607 {
608 	p1->feature_req_word = req_u->req3.tp_feature_req_word;
609 }
610 
611 static void init_prb_bdqc(struct packet_sock *po,
612 			struct packet_ring_buffer *rb,
613 			struct pgv *pg_vec,
614 			union tpacket_req_u *req_u)
615 {
616 	struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
617 	struct tpacket_block_desc *pbd;
618 
619 	memset(p1, 0x0, sizeof(*p1));
620 
621 	p1->knxt_seq_num = 1;
622 	p1->pkbdq = pg_vec;
623 	pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
624 	p1->pkblk_start	= pg_vec[0].buffer;
625 	p1->kblk_size = req_u->req3.tp_block_size;
626 	p1->knum_blocks	= req_u->req3.tp_block_nr;
627 	p1->hdrlen = po->tp_hdrlen;
628 	p1->version = po->tp_version;
629 	p1->last_kactive_blk_num = 0;
630 	po->stats.stats3.tp_freeze_q_cnt = 0;
631 	if (req_u->req3.tp_retire_blk_tov)
632 		p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
633 	else
634 		p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
635 						req_u->req3.tp_block_size);
636 	p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
637 	p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
638 	rwlock_init(&p1->blk_fill_in_prog_lock);
639 
640 	p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
641 	prb_init_ft_ops(p1, req_u);
642 	prb_setup_retire_blk_timer(po);
643 	prb_open_block(p1, pbd);
644 }
645 
646 /*  Do NOT update the last_blk_num first.
647  *  Assumes sk_buff_head lock is held.
648  */
649 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
650 {
651 	mod_timer(&pkc->retire_blk_timer,
652 			jiffies + pkc->tov_in_jiffies);
653 	pkc->last_kactive_blk_num = pkc->kactive_blk_num;
654 }
655 
656 /*
657  * Timer logic:
658  * 1) We refresh the timer only when we open a block.
659  *    By doing this we don't waste cycles refreshing the timer
660  *	  on packet-by-packet basis.
661  *
662  * With a 1MB block-size, on a 1Gbps line, it will take
663  * i) ~8 ms to fill a block + ii) memcpy etc.
664  * In this cut we are not accounting for the memcpy time.
665  *
666  * So, if the user sets the 'tmo' to 10ms then the timer
667  * will never fire while the block is still getting filled
668  * (which is what we want). However, the user could choose
669  * to close a block early and that's fine.
670  *
671  * But when the timer does fire, we check whether or not to refresh it.
672  * Since the tmo granularity is in msecs, it is not too expensive
673  * to refresh the timer, lets say every '8' msecs.
674  * Either the user can set the 'tmo' or we can derive it based on
675  * a) line-speed and b) block-size.
676  * prb_calc_retire_blk_tmo() calculates the tmo.
677  *
678  */
679 static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
680 {
681 	struct packet_sock *po =
682 		from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
683 	struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
684 	unsigned int frozen;
685 	struct tpacket_block_desc *pbd;
686 
687 	spin_lock(&po->sk.sk_receive_queue.lock);
688 
689 	frozen = prb_queue_frozen(pkc);
690 	pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
691 
692 	if (unlikely(pkc->delete_blk_timer))
693 		goto out;
694 
695 	/* We only need to plug the race when the block is partially filled.
696 	 * tpacket_rcv:
697 	 *		lock(); increment BLOCK_NUM_PKTS; unlock()
698 	 *		copy_bits() is in progress ...
699 	 *		timer fires on other cpu:
700 	 *		we can't retire the current block because copy_bits
701 	 *		is in progress.
702 	 *
703 	 */
704 	if (BLOCK_NUM_PKTS(pbd)) {
705 		/* Waiting for skb_copy_bits to finish... */
706 		write_lock(&pkc->blk_fill_in_prog_lock);
707 		write_unlock(&pkc->blk_fill_in_prog_lock);
708 	}
709 
710 	if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
711 		if (!frozen) {
712 			if (!BLOCK_NUM_PKTS(pbd)) {
713 				/* An empty block. Just refresh the timer. */
714 				goto refresh_timer;
715 			}
716 			prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
717 			if (!prb_dispatch_next_block(pkc, po))
718 				goto refresh_timer;
719 			else
720 				goto out;
721 		} else {
722 			/* Case 1. Queue was frozen because user-space was
723 			 *	   lagging behind.
724 			 */
725 			if (prb_curr_blk_in_use(pbd)) {
726 				/*
727 				 * Ok, user-space is still behind.
728 				 * So just refresh the timer.
729 				 */
730 				goto refresh_timer;
731 			} else {
732 			       /* Case 2. queue was frozen,user-space caught up,
733 				* now the link went idle && the timer fired.
734 				* We don't have a block to close.So we open this
735 				* block and restart the timer.
736 				* opening a block thaws the queue,restarts timer
737 				* Thawing/timer-refresh is a side effect.
738 				*/
739 				prb_open_block(pkc, pbd);
740 				goto out;
741 			}
742 		}
743 	}
744 
745 refresh_timer:
746 	_prb_refresh_rx_retire_blk_timer(pkc);
747 
748 out:
749 	spin_unlock(&po->sk.sk_receive_queue.lock);
750 }
751 
752 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
753 		struct tpacket_block_desc *pbd1, __u32 status)
754 {
755 	/* Flush everything minus the block header */
756 
757 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
758 	u8 *start, *end;
759 
760 	start = (u8 *)pbd1;
761 
762 	/* Skip the block header(we know header WILL fit in 4K) */
763 	start += PAGE_SIZE;
764 
765 	end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
766 	for (; start < end; start += PAGE_SIZE)
767 		flush_dcache_page(pgv_to_page(start));
768 
769 	smp_wmb();
770 #endif
771 
772 	/* Now update the block status. */
773 
774 	BLOCK_STATUS(pbd1) = status;
775 
776 	/* Flush the block header */
777 
778 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
779 	start = (u8 *)pbd1;
780 	flush_dcache_page(pgv_to_page(start));
781 
782 	smp_wmb();
783 #endif
784 }
785 
786 /*
787  * Side effect:
788  *
789  * 1) flush the block
790  * 2) Increment active_blk_num
791  *
792  * Note:We DONT refresh the timer on purpose.
793  *	Because almost always the next block will be opened.
794  */
795 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
796 		struct tpacket_block_desc *pbd1,
797 		struct packet_sock *po, unsigned int stat)
798 {
799 	__u32 status = TP_STATUS_USER | stat;
800 
801 	struct tpacket3_hdr *last_pkt;
802 	struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
803 	struct sock *sk = &po->sk;
804 
805 	if (atomic_read(&po->tp_drops))
806 		status |= TP_STATUS_LOSING;
807 
808 	last_pkt = (struct tpacket3_hdr *)pkc1->prev;
809 	last_pkt->tp_next_offset = 0;
810 
811 	/* Get the ts of the last pkt */
812 	if (BLOCK_NUM_PKTS(pbd1)) {
813 		h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
814 		h1->ts_last_pkt.ts_nsec	= last_pkt->tp_nsec;
815 	} else {
816 		/* Ok, we tmo'd - so get the current time.
817 		 *
818 		 * It shouldn't really happen as we don't close empty
819 		 * blocks. See prb_retire_rx_blk_timer_expired().
820 		 */
821 		struct timespec64 ts;
822 		ktime_get_real_ts64(&ts);
823 		h1->ts_last_pkt.ts_sec = ts.tv_sec;
824 		h1->ts_last_pkt.ts_nsec	= ts.tv_nsec;
825 	}
826 
827 	smp_wmb();
828 
829 	/* Flush the block */
830 	prb_flush_block(pkc1, pbd1, status);
831 
832 	sk->sk_data_ready(sk);
833 
834 	pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
835 }
836 
837 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
838 {
839 	pkc->reset_pending_on_curr_blk = 0;
840 }
841 
842 /*
843  * Side effect of opening a block:
844  *
845  * 1) prb_queue is thawed.
846  * 2) retire_blk_timer is refreshed.
847  *
848  */
849 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
850 	struct tpacket_block_desc *pbd1)
851 {
852 	struct timespec64 ts;
853 	struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
854 
855 	smp_rmb();
856 
857 	/* We could have just memset this but we will lose the
858 	 * flexibility of making the priv area sticky
859 	 */
860 
861 	BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
862 	BLOCK_NUM_PKTS(pbd1) = 0;
863 	BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
864 
865 	ktime_get_real_ts64(&ts);
866 
867 	h1->ts_first_pkt.ts_sec = ts.tv_sec;
868 	h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
869 
870 	pkc1->pkblk_start = (char *)pbd1;
871 	pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
872 
873 	BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
874 	BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
875 
876 	pbd1->version = pkc1->version;
877 	pkc1->prev = pkc1->nxt_offset;
878 	pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
879 
880 	prb_thaw_queue(pkc1);
881 	_prb_refresh_rx_retire_blk_timer(pkc1);
882 
883 	smp_wmb();
884 }
885 
886 /*
887  * Queue freeze logic:
888  * 1) Assume tp_block_nr = 8 blocks.
889  * 2) At time 't0', user opens Rx ring.
890  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
891  * 4) user-space is either sleeping or processing block '0'.
892  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
893  *    it will close block-7,loop around and try to fill block '0'.
894  *    call-flow:
895  *    __packet_lookup_frame_in_block
896  *      prb_retire_current_block()
897  *      prb_dispatch_next_block()
898  *        |->(BLOCK_STATUS == USER) evaluates to true
899  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
900  * 6) Now there are two cases:
901  *    6.1) Link goes idle right after the queue is frozen.
902  *         But remember, the last open_block() refreshed the timer.
903  *         When this timer expires,it will refresh itself so that we can
904  *         re-open block-0 in near future.
905  *    6.2) Link is busy and keeps on receiving packets. This is a simple
906  *         case and __packet_lookup_frame_in_block will check if block-0
907  *         is free and can now be re-used.
908  */
909 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
910 				  struct packet_sock *po)
911 {
912 	pkc->reset_pending_on_curr_blk = 1;
913 	po->stats.stats3.tp_freeze_q_cnt++;
914 }
915 
916 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
917 
918 /*
919  * If the next block is free then we will dispatch it
920  * and return a good offset.
921  * Else, we will freeze the queue.
922  * So, caller must check the return value.
923  */
924 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
925 		struct packet_sock *po)
926 {
927 	struct tpacket_block_desc *pbd;
928 
929 	smp_rmb();
930 
931 	/* 1. Get current block num */
932 	pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
933 
934 	/* 2. If this block is currently in_use then freeze the queue */
935 	if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
936 		prb_freeze_queue(pkc, po);
937 		return NULL;
938 	}
939 
940 	/*
941 	 * 3.
942 	 * open this block and return the offset where the first packet
943 	 * needs to get stored.
944 	 */
945 	prb_open_block(pkc, pbd);
946 	return (void *)pkc->nxt_offset;
947 }
948 
949 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
950 		struct packet_sock *po, unsigned int status)
951 {
952 	struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
953 
954 	/* retire/close the current block */
955 	if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
956 		/*
957 		 * Plug the case where copy_bits() is in progress on
958 		 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
959 		 * have space to copy the pkt in the current block and
960 		 * called prb_retire_current_block()
961 		 *
962 		 * We don't need to worry about the TMO case because
963 		 * the timer-handler already handled this case.
964 		 */
965 		if (!(status & TP_STATUS_BLK_TMO)) {
966 			/* Waiting for skb_copy_bits to finish... */
967 			write_lock(&pkc->blk_fill_in_prog_lock);
968 			write_unlock(&pkc->blk_fill_in_prog_lock);
969 		}
970 		prb_close_block(pkc, pbd, po, status);
971 		return;
972 	}
973 }
974 
975 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
976 {
977 	return TP_STATUS_USER & BLOCK_STATUS(pbd);
978 }
979 
980 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
981 {
982 	return pkc->reset_pending_on_curr_blk;
983 }
984 
985 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
986 	__releases(&pkc->blk_fill_in_prog_lock)
987 {
988 	struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
989 
990 	read_unlock(&pkc->blk_fill_in_prog_lock);
991 }
992 
993 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
994 			struct tpacket3_hdr *ppd)
995 {
996 	ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
997 }
998 
999 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
1000 			struct tpacket3_hdr *ppd)
1001 {
1002 	ppd->hv1.tp_rxhash = 0;
1003 }
1004 
1005 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
1006 			struct tpacket3_hdr *ppd)
1007 {
1008 	if (skb_vlan_tag_present(pkc->skb)) {
1009 		ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1010 		ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1011 		ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1012 	} else {
1013 		ppd->hv1.tp_vlan_tci = 0;
1014 		ppd->hv1.tp_vlan_tpid = 0;
1015 		ppd->tp_status = TP_STATUS_AVAILABLE;
1016 	}
1017 }
1018 
1019 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1020 			struct tpacket3_hdr *ppd)
1021 {
1022 	ppd->hv1.tp_padding = 0;
1023 	prb_fill_vlan_info(pkc, ppd);
1024 
1025 	if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1026 		prb_fill_rxhash(pkc, ppd);
1027 	else
1028 		prb_clear_rxhash(pkc, ppd);
1029 }
1030 
1031 static void prb_fill_curr_block(char *curr,
1032 				struct tpacket_kbdq_core *pkc,
1033 				struct tpacket_block_desc *pbd,
1034 				unsigned int len)
1035 	__acquires(&pkc->blk_fill_in_prog_lock)
1036 {
1037 	struct tpacket3_hdr *ppd;
1038 
1039 	ppd  = (struct tpacket3_hdr *)curr;
1040 	ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1041 	pkc->prev = curr;
1042 	pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1043 	BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1044 	BLOCK_NUM_PKTS(pbd) += 1;
1045 	read_lock(&pkc->blk_fill_in_prog_lock);
1046 	prb_run_all_ft_ops(pkc, ppd);
1047 }
1048 
1049 /* Assumes caller has the sk->rx_queue.lock */
1050 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1051 					    struct sk_buff *skb,
1052 					    unsigned int len
1053 					    )
1054 {
1055 	struct tpacket_kbdq_core *pkc;
1056 	struct tpacket_block_desc *pbd;
1057 	char *curr, *end;
1058 
1059 	pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1060 	pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1061 
1062 	/* Queue is frozen when user space is lagging behind */
1063 	if (prb_queue_frozen(pkc)) {
1064 		/*
1065 		 * Check if that last block which caused the queue to freeze,
1066 		 * is still in_use by user-space.
1067 		 */
1068 		if (prb_curr_blk_in_use(pbd)) {
1069 			/* Can't record this packet */
1070 			return NULL;
1071 		} else {
1072 			/*
1073 			 * Ok, the block was released by user-space.
1074 			 * Now let's open that block.
1075 			 * opening a block also thaws the queue.
1076 			 * Thawing is a side effect.
1077 			 */
1078 			prb_open_block(pkc, pbd);
1079 		}
1080 	}
1081 
1082 	smp_mb();
1083 	curr = pkc->nxt_offset;
1084 	pkc->skb = skb;
1085 	end = (char *)pbd + pkc->kblk_size;
1086 
1087 	/* first try the current block */
1088 	if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1089 		prb_fill_curr_block(curr, pkc, pbd, len);
1090 		return (void *)curr;
1091 	}
1092 
1093 	/* Ok, close the current block */
1094 	prb_retire_current_block(pkc, po, 0);
1095 
1096 	/* Now, try to dispatch the next block */
1097 	curr = (char *)prb_dispatch_next_block(pkc, po);
1098 	if (curr) {
1099 		pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1100 		prb_fill_curr_block(curr, pkc, pbd, len);
1101 		return (void *)curr;
1102 	}
1103 
1104 	/*
1105 	 * No free blocks are available.user_space hasn't caught up yet.
1106 	 * Queue was just frozen and now this packet will get dropped.
1107 	 */
1108 	return NULL;
1109 }
1110 
1111 static void *packet_current_rx_frame(struct packet_sock *po,
1112 					    struct sk_buff *skb,
1113 					    int status, unsigned int len)
1114 {
1115 	char *curr = NULL;
1116 	switch (po->tp_version) {
1117 	case TPACKET_V1:
1118 	case TPACKET_V2:
1119 		curr = packet_lookup_frame(po, &po->rx_ring,
1120 					po->rx_ring.head, status);
1121 		return curr;
1122 	case TPACKET_V3:
1123 		return __packet_lookup_frame_in_block(po, skb, len);
1124 	default:
1125 		WARN(1, "TPACKET version not supported\n");
1126 		BUG();
1127 		return NULL;
1128 	}
1129 }
1130 
1131 static void *prb_lookup_block(const struct packet_sock *po,
1132 			      const struct packet_ring_buffer *rb,
1133 			      unsigned int idx,
1134 			      int status)
1135 {
1136 	struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1137 	struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1138 
1139 	if (status != BLOCK_STATUS(pbd))
1140 		return NULL;
1141 	return pbd;
1142 }
1143 
1144 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1145 {
1146 	unsigned int prev;
1147 	if (rb->prb_bdqc.kactive_blk_num)
1148 		prev = rb->prb_bdqc.kactive_blk_num-1;
1149 	else
1150 		prev = rb->prb_bdqc.knum_blocks-1;
1151 	return prev;
1152 }
1153 
1154 /* Assumes caller has held the rx_queue.lock */
1155 static void *__prb_previous_block(struct packet_sock *po,
1156 					 struct packet_ring_buffer *rb,
1157 					 int status)
1158 {
1159 	unsigned int previous = prb_previous_blk_num(rb);
1160 	return prb_lookup_block(po, rb, previous, status);
1161 }
1162 
1163 static void *packet_previous_rx_frame(struct packet_sock *po,
1164 					     struct packet_ring_buffer *rb,
1165 					     int status)
1166 {
1167 	if (po->tp_version <= TPACKET_V2)
1168 		return packet_previous_frame(po, rb, status);
1169 
1170 	return __prb_previous_block(po, rb, status);
1171 }
1172 
1173 static void packet_increment_rx_head(struct packet_sock *po,
1174 					    struct packet_ring_buffer *rb)
1175 {
1176 	switch (po->tp_version) {
1177 	case TPACKET_V1:
1178 	case TPACKET_V2:
1179 		return packet_increment_head(rb);
1180 	case TPACKET_V3:
1181 	default:
1182 		WARN(1, "TPACKET version not supported.\n");
1183 		BUG();
1184 		return;
1185 	}
1186 }
1187 
1188 static void *packet_previous_frame(struct packet_sock *po,
1189 		struct packet_ring_buffer *rb,
1190 		int status)
1191 {
1192 	unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1193 	return packet_lookup_frame(po, rb, previous, status);
1194 }
1195 
1196 static void packet_increment_head(struct packet_ring_buffer *buff)
1197 {
1198 	buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1199 }
1200 
1201 static void packet_inc_pending(struct packet_ring_buffer *rb)
1202 {
1203 	this_cpu_inc(*rb->pending_refcnt);
1204 }
1205 
1206 static void packet_dec_pending(struct packet_ring_buffer *rb)
1207 {
1208 	this_cpu_dec(*rb->pending_refcnt);
1209 }
1210 
1211 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1212 {
1213 	unsigned int refcnt = 0;
1214 	int cpu;
1215 
1216 	/* We don't use pending refcount in rx_ring. */
1217 	if (rb->pending_refcnt == NULL)
1218 		return 0;
1219 
1220 	for_each_possible_cpu(cpu)
1221 		refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1222 
1223 	return refcnt;
1224 }
1225 
1226 static int packet_alloc_pending(struct packet_sock *po)
1227 {
1228 	po->rx_ring.pending_refcnt = NULL;
1229 
1230 	po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1231 	if (unlikely(po->tx_ring.pending_refcnt == NULL))
1232 		return -ENOBUFS;
1233 
1234 	return 0;
1235 }
1236 
1237 static void packet_free_pending(struct packet_sock *po)
1238 {
1239 	free_percpu(po->tx_ring.pending_refcnt);
1240 }
1241 
1242 #define ROOM_POW_OFF	2
1243 #define ROOM_NONE	0x0
1244 #define ROOM_LOW	0x1
1245 #define ROOM_NORMAL	0x2
1246 
1247 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1248 {
1249 	int idx, len;
1250 
1251 	len = READ_ONCE(po->rx_ring.frame_max) + 1;
1252 	idx = READ_ONCE(po->rx_ring.head);
1253 	if (pow_off)
1254 		idx += len >> pow_off;
1255 	if (idx >= len)
1256 		idx -= len;
1257 	return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1258 }
1259 
1260 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1261 {
1262 	int idx, len;
1263 
1264 	len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1265 	idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1266 	if (pow_off)
1267 		idx += len >> pow_off;
1268 	if (idx >= len)
1269 		idx -= len;
1270 	return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1271 }
1272 
1273 static int __packet_rcv_has_room(const struct packet_sock *po,
1274 				 const struct sk_buff *skb)
1275 {
1276 	const struct sock *sk = &po->sk;
1277 	int ret = ROOM_NONE;
1278 
1279 	if (po->prot_hook.func != tpacket_rcv) {
1280 		int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1281 		int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1282 				   - (skb ? skb->truesize : 0);
1283 
1284 		if (avail > (rcvbuf >> ROOM_POW_OFF))
1285 			return ROOM_NORMAL;
1286 		else if (avail > 0)
1287 			return ROOM_LOW;
1288 		else
1289 			return ROOM_NONE;
1290 	}
1291 
1292 	if (po->tp_version == TPACKET_V3) {
1293 		if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1294 			ret = ROOM_NORMAL;
1295 		else if (__tpacket_v3_has_room(po, 0))
1296 			ret = ROOM_LOW;
1297 	} else {
1298 		if (__tpacket_has_room(po, ROOM_POW_OFF))
1299 			ret = ROOM_NORMAL;
1300 		else if (__tpacket_has_room(po, 0))
1301 			ret = ROOM_LOW;
1302 	}
1303 
1304 	return ret;
1305 }
1306 
1307 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1308 {
1309 	int pressure, ret;
1310 
1311 	ret = __packet_rcv_has_room(po, skb);
1312 	pressure = ret != ROOM_NORMAL;
1313 
1314 	if (READ_ONCE(po->pressure) != pressure)
1315 		WRITE_ONCE(po->pressure, pressure);
1316 
1317 	return ret;
1318 }
1319 
1320 static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1321 {
1322 	if (READ_ONCE(po->pressure) &&
1323 	    __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1324 		WRITE_ONCE(po->pressure,  0);
1325 }
1326 
1327 static void packet_sock_destruct(struct sock *sk)
1328 {
1329 	skb_queue_purge(&sk->sk_error_queue);
1330 
1331 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1332 	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1333 
1334 	if (!sock_flag(sk, SOCK_DEAD)) {
1335 		pr_err("Attempt to release alive packet socket: %p\n", sk);
1336 		return;
1337 	}
1338 
1339 	sk_refcnt_debug_dec(sk);
1340 }
1341 
1342 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1343 {
1344 	u32 *history = po->rollover->history;
1345 	u32 victim, rxhash;
1346 	int i, count = 0;
1347 
1348 	rxhash = skb_get_hash(skb);
1349 	for (i = 0; i < ROLLOVER_HLEN; i++)
1350 		if (READ_ONCE(history[i]) == rxhash)
1351 			count++;
1352 
1353 	victim = prandom_u32() % ROLLOVER_HLEN;
1354 
1355 	/* Avoid dirtying the cache line if possible */
1356 	if (READ_ONCE(history[victim]) != rxhash)
1357 		WRITE_ONCE(history[victim], rxhash);
1358 
1359 	return count > (ROLLOVER_HLEN >> 1);
1360 }
1361 
1362 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1363 				      struct sk_buff *skb,
1364 				      unsigned int num)
1365 {
1366 	return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1367 }
1368 
1369 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1370 				    struct sk_buff *skb,
1371 				    unsigned int num)
1372 {
1373 	unsigned int val = atomic_inc_return(&f->rr_cur);
1374 
1375 	return val % num;
1376 }
1377 
1378 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1379 				     struct sk_buff *skb,
1380 				     unsigned int num)
1381 {
1382 	return smp_processor_id() % num;
1383 }
1384 
1385 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1386 				     struct sk_buff *skb,
1387 				     unsigned int num)
1388 {
1389 	return prandom_u32_max(num);
1390 }
1391 
1392 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1393 					  struct sk_buff *skb,
1394 					  unsigned int idx, bool try_self,
1395 					  unsigned int num)
1396 {
1397 	struct packet_sock *po, *po_next, *po_skip = NULL;
1398 	unsigned int i, j, room = ROOM_NONE;
1399 
1400 	po = pkt_sk(rcu_dereference(f->arr[idx]));
1401 
1402 	if (try_self) {
1403 		room = packet_rcv_has_room(po, skb);
1404 		if (room == ROOM_NORMAL ||
1405 		    (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1406 			return idx;
1407 		po_skip = po;
1408 	}
1409 
1410 	i = j = min_t(int, po->rollover->sock, num - 1);
1411 	do {
1412 		po_next = pkt_sk(rcu_dereference(f->arr[i]));
1413 		if (po_next != po_skip && !READ_ONCE(po_next->pressure) &&
1414 		    packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1415 			if (i != j)
1416 				po->rollover->sock = i;
1417 			atomic_long_inc(&po->rollover->num);
1418 			if (room == ROOM_LOW)
1419 				atomic_long_inc(&po->rollover->num_huge);
1420 			return i;
1421 		}
1422 
1423 		if (++i == num)
1424 			i = 0;
1425 	} while (i != j);
1426 
1427 	atomic_long_inc(&po->rollover->num_failed);
1428 	return idx;
1429 }
1430 
1431 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1432 				    struct sk_buff *skb,
1433 				    unsigned int num)
1434 {
1435 	return skb_get_queue_mapping(skb) % num;
1436 }
1437 
1438 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1439 				     struct sk_buff *skb,
1440 				     unsigned int num)
1441 {
1442 	struct bpf_prog *prog;
1443 	unsigned int ret = 0;
1444 
1445 	rcu_read_lock();
1446 	prog = rcu_dereference(f->bpf_prog);
1447 	if (prog)
1448 		ret = bpf_prog_run_clear_cb(prog, skb) % num;
1449 	rcu_read_unlock();
1450 
1451 	return ret;
1452 }
1453 
1454 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1455 {
1456 	return f->flags & (flag >> 8);
1457 }
1458 
1459 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1460 			     struct packet_type *pt, struct net_device *orig_dev)
1461 {
1462 	struct packet_fanout *f = pt->af_packet_priv;
1463 	unsigned int num = READ_ONCE(f->num_members);
1464 	struct net *net = read_pnet(&f->net);
1465 	struct packet_sock *po;
1466 	unsigned int idx;
1467 
1468 	if (!net_eq(dev_net(dev), net) || !num) {
1469 		kfree_skb(skb);
1470 		return 0;
1471 	}
1472 
1473 	if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1474 		skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1475 		if (!skb)
1476 			return 0;
1477 	}
1478 	switch (f->type) {
1479 	case PACKET_FANOUT_HASH:
1480 	default:
1481 		idx = fanout_demux_hash(f, skb, num);
1482 		break;
1483 	case PACKET_FANOUT_LB:
1484 		idx = fanout_demux_lb(f, skb, num);
1485 		break;
1486 	case PACKET_FANOUT_CPU:
1487 		idx = fanout_demux_cpu(f, skb, num);
1488 		break;
1489 	case PACKET_FANOUT_RND:
1490 		idx = fanout_demux_rnd(f, skb, num);
1491 		break;
1492 	case PACKET_FANOUT_QM:
1493 		idx = fanout_demux_qm(f, skb, num);
1494 		break;
1495 	case PACKET_FANOUT_ROLLOVER:
1496 		idx = fanout_demux_rollover(f, skb, 0, false, num);
1497 		break;
1498 	case PACKET_FANOUT_CBPF:
1499 	case PACKET_FANOUT_EBPF:
1500 		idx = fanout_demux_bpf(f, skb, num);
1501 		break;
1502 	}
1503 
1504 	if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1505 		idx = fanout_demux_rollover(f, skb, idx, true, num);
1506 
1507 	po = pkt_sk(rcu_dereference(f->arr[idx]));
1508 	return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1509 }
1510 
1511 DEFINE_MUTEX(fanout_mutex);
1512 EXPORT_SYMBOL_GPL(fanout_mutex);
1513 static LIST_HEAD(fanout_list);
1514 static u16 fanout_next_id;
1515 
1516 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1517 {
1518 	struct packet_fanout *f = po->fanout;
1519 
1520 	spin_lock(&f->lock);
1521 	rcu_assign_pointer(f->arr[f->num_members], sk);
1522 	smp_wmb();
1523 	f->num_members++;
1524 	if (f->num_members == 1)
1525 		dev_add_pack(&f->prot_hook);
1526 	spin_unlock(&f->lock);
1527 }
1528 
1529 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1530 {
1531 	struct packet_fanout *f = po->fanout;
1532 	int i;
1533 
1534 	spin_lock(&f->lock);
1535 	for (i = 0; i < f->num_members; i++) {
1536 		if (rcu_dereference_protected(f->arr[i],
1537 					      lockdep_is_held(&f->lock)) == sk)
1538 			break;
1539 	}
1540 	BUG_ON(i >= f->num_members);
1541 	rcu_assign_pointer(f->arr[i],
1542 			   rcu_dereference_protected(f->arr[f->num_members - 1],
1543 						     lockdep_is_held(&f->lock)));
1544 	f->num_members--;
1545 	if (f->num_members == 0)
1546 		__dev_remove_pack(&f->prot_hook);
1547 	spin_unlock(&f->lock);
1548 }
1549 
1550 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1551 {
1552 	if (sk->sk_family != PF_PACKET)
1553 		return false;
1554 
1555 	return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1556 }
1557 
1558 static void fanout_init_data(struct packet_fanout *f)
1559 {
1560 	switch (f->type) {
1561 	case PACKET_FANOUT_LB:
1562 		atomic_set(&f->rr_cur, 0);
1563 		break;
1564 	case PACKET_FANOUT_CBPF:
1565 	case PACKET_FANOUT_EBPF:
1566 		RCU_INIT_POINTER(f->bpf_prog, NULL);
1567 		break;
1568 	}
1569 }
1570 
1571 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1572 {
1573 	struct bpf_prog *old;
1574 
1575 	spin_lock(&f->lock);
1576 	old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1577 	rcu_assign_pointer(f->bpf_prog, new);
1578 	spin_unlock(&f->lock);
1579 
1580 	if (old) {
1581 		synchronize_net();
1582 		bpf_prog_destroy(old);
1583 	}
1584 }
1585 
1586 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data,
1587 				unsigned int len)
1588 {
1589 	struct bpf_prog *new;
1590 	struct sock_fprog fprog;
1591 	int ret;
1592 
1593 	if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1594 		return -EPERM;
1595 
1596 	ret = copy_bpf_fprog_from_user(&fprog, data, len);
1597 	if (ret)
1598 		return ret;
1599 
1600 	ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1601 	if (ret)
1602 		return ret;
1603 
1604 	__fanout_set_data_bpf(po->fanout, new);
1605 	return 0;
1606 }
1607 
1608 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data,
1609 				unsigned int len)
1610 {
1611 	struct bpf_prog *new;
1612 	u32 fd;
1613 
1614 	if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1615 		return -EPERM;
1616 	if (len != sizeof(fd))
1617 		return -EINVAL;
1618 	if (copy_from_sockptr(&fd, data, len))
1619 		return -EFAULT;
1620 
1621 	new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1622 	if (IS_ERR(new))
1623 		return PTR_ERR(new);
1624 
1625 	__fanout_set_data_bpf(po->fanout, new);
1626 	return 0;
1627 }
1628 
1629 static int fanout_set_data(struct packet_sock *po, sockptr_t data,
1630 			   unsigned int len)
1631 {
1632 	switch (po->fanout->type) {
1633 	case PACKET_FANOUT_CBPF:
1634 		return fanout_set_data_cbpf(po, data, len);
1635 	case PACKET_FANOUT_EBPF:
1636 		return fanout_set_data_ebpf(po, data, len);
1637 	default:
1638 		return -EINVAL;
1639 	}
1640 }
1641 
1642 static void fanout_release_data(struct packet_fanout *f)
1643 {
1644 	switch (f->type) {
1645 	case PACKET_FANOUT_CBPF:
1646 	case PACKET_FANOUT_EBPF:
1647 		__fanout_set_data_bpf(f, NULL);
1648 	}
1649 }
1650 
1651 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1652 {
1653 	struct packet_fanout *f;
1654 
1655 	list_for_each_entry(f, &fanout_list, list) {
1656 		if (f->id == candidate_id &&
1657 		    read_pnet(&f->net) == sock_net(sk)) {
1658 			return false;
1659 		}
1660 	}
1661 	return true;
1662 }
1663 
1664 static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1665 {
1666 	u16 id = fanout_next_id;
1667 
1668 	do {
1669 		if (__fanout_id_is_free(sk, id)) {
1670 			*new_id = id;
1671 			fanout_next_id = id + 1;
1672 			return true;
1673 		}
1674 
1675 		id++;
1676 	} while (id != fanout_next_id);
1677 
1678 	return false;
1679 }
1680 
1681 static int fanout_add(struct sock *sk, struct fanout_args *args)
1682 {
1683 	struct packet_rollover *rollover = NULL;
1684 	struct packet_sock *po = pkt_sk(sk);
1685 	u16 type_flags = args->type_flags;
1686 	struct packet_fanout *f, *match;
1687 	u8 type = type_flags & 0xff;
1688 	u8 flags = type_flags >> 8;
1689 	u16 id = args->id;
1690 	int err;
1691 
1692 	switch (type) {
1693 	case PACKET_FANOUT_ROLLOVER:
1694 		if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1695 			return -EINVAL;
1696 		break;
1697 	case PACKET_FANOUT_HASH:
1698 	case PACKET_FANOUT_LB:
1699 	case PACKET_FANOUT_CPU:
1700 	case PACKET_FANOUT_RND:
1701 	case PACKET_FANOUT_QM:
1702 	case PACKET_FANOUT_CBPF:
1703 	case PACKET_FANOUT_EBPF:
1704 		break;
1705 	default:
1706 		return -EINVAL;
1707 	}
1708 
1709 	mutex_lock(&fanout_mutex);
1710 
1711 	err = -EALREADY;
1712 	if (po->fanout)
1713 		goto out;
1714 
1715 	if (type == PACKET_FANOUT_ROLLOVER ||
1716 	    (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1717 		err = -ENOMEM;
1718 		rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1719 		if (!rollover)
1720 			goto out;
1721 		atomic_long_set(&rollover->num, 0);
1722 		atomic_long_set(&rollover->num_huge, 0);
1723 		atomic_long_set(&rollover->num_failed, 0);
1724 	}
1725 
1726 	if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1727 		if (id != 0) {
1728 			err = -EINVAL;
1729 			goto out;
1730 		}
1731 		if (!fanout_find_new_id(sk, &id)) {
1732 			err = -ENOMEM;
1733 			goto out;
1734 		}
1735 		/* ephemeral flag for the first socket in the group: drop it */
1736 		flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1737 	}
1738 
1739 	match = NULL;
1740 	list_for_each_entry(f, &fanout_list, list) {
1741 		if (f->id == id &&
1742 		    read_pnet(&f->net) == sock_net(sk)) {
1743 			match = f;
1744 			break;
1745 		}
1746 	}
1747 	err = -EINVAL;
1748 	if (match) {
1749 		if (match->flags != flags)
1750 			goto out;
1751 		if (args->max_num_members &&
1752 		    args->max_num_members != match->max_num_members)
1753 			goto out;
1754 	} else {
1755 		if (args->max_num_members > PACKET_FANOUT_MAX)
1756 			goto out;
1757 		if (!args->max_num_members)
1758 			/* legacy PACKET_FANOUT_MAX */
1759 			args->max_num_members = 256;
1760 		err = -ENOMEM;
1761 		match = kvzalloc(struct_size(match, arr, args->max_num_members),
1762 				 GFP_KERNEL);
1763 		if (!match)
1764 			goto out;
1765 		write_pnet(&match->net, sock_net(sk));
1766 		match->id = id;
1767 		match->type = type;
1768 		match->flags = flags;
1769 		INIT_LIST_HEAD(&match->list);
1770 		spin_lock_init(&match->lock);
1771 		refcount_set(&match->sk_ref, 0);
1772 		fanout_init_data(match);
1773 		match->prot_hook.type = po->prot_hook.type;
1774 		match->prot_hook.dev = po->prot_hook.dev;
1775 		match->prot_hook.func = packet_rcv_fanout;
1776 		match->prot_hook.af_packet_priv = match;
1777 		match->prot_hook.af_packet_net = read_pnet(&match->net);
1778 		match->prot_hook.id_match = match_fanout_group;
1779 		match->max_num_members = args->max_num_members;
1780 		list_add(&match->list, &fanout_list);
1781 	}
1782 	err = -EINVAL;
1783 
1784 	spin_lock(&po->bind_lock);
1785 	if (po->running &&
1786 	    match->type == type &&
1787 	    match->prot_hook.type == po->prot_hook.type &&
1788 	    match->prot_hook.dev == po->prot_hook.dev) {
1789 		err = -ENOSPC;
1790 		if (refcount_read(&match->sk_ref) < match->max_num_members) {
1791 			__dev_remove_pack(&po->prot_hook);
1792 
1793 			/* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */
1794 			WRITE_ONCE(po->fanout, match);
1795 
1796 			po->rollover = rollover;
1797 			rollover = NULL;
1798 			refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1799 			__fanout_link(sk, po);
1800 			err = 0;
1801 		}
1802 	}
1803 	spin_unlock(&po->bind_lock);
1804 
1805 	if (err && !refcount_read(&match->sk_ref)) {
1806 		list_del(&match->list);
1807 		kvfree(match);
1808 	}
1809 
1810 out:
1811 	kfree(rollover);
1812 	mutex_unlock(&fanout_mutex);
1813 	return err;
1814 }
1815 
1816 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1817  * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1818  * It is the responsibility of the caller to call fanout_release_data() and
1819  * free the returned packet_fanout (after synchronize_net())
1820  */
1821 static struct packet_fanout *fanout_release(struct sock *sk)
1822 {
1823 	struct packet_sock *po = pkt_sk(sk);
1824 	struct packet_fanout *f;
1825 
1826 	mutex_lock(&fanout_mutex);
1827 	f = po->fanout;
1828 	if (f) {
1829 		po->fanout = NULL;
1830 
1831 		if (refcount_dec_and_test(&f->sk_ref))
1832 			list_del(&f->list);
1833 		else
1834 			f = NULL;
1835 	}
1836 	mutex_unlock(&fanout_mutex);
1837 
1838 	return f;
1839 }
1840 
1841 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1842 					  struct sk_buff *skb)
1843 {
1844 	/* Earlier code assumed this would be a VLAN pkt, double-check
1845 	 * this now that we have the actual packet in hand. We can only
1846 	 * do this check on Ethernet devices.
1847 	 */
1848 	if (unlikely(dev->type != ARPHRD_ETHER))
1849 		return false;
1850 
1851 	skb_reset_mac_header(skb);
1852 	return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1853 }
1854 
1855 static const struct proto_ops packet_ops;
1856 
1857 static const struct proto_ops packet_ops_spkt;
1858 
1859 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1860 			   struct packet_type *pt, struct net_device *orig_dev)
1861 {
1862 	struct sock *sk;
1863 	struct sockaddr_pkt *spkt;
1864 
1865 	/*
1866 	 *	When we registered the protocol we saved the socket in the data
1867 	 *	field for just this event.
1868 	 */
1869 
1870 	sk = pt->af_packet_priv;
1871 
1872 	/*
1873 	 *	Yank back the headers [hope the device set this
1874 	 *	right or kerboom...]
1875 	 *
1876 	 *	Incoming packets have ll header pulled,
1877 	 *	push it back.
1878 	 *
1879 	 *	For outgoing ones skb->data == skb_mac_header(skb)
1880 	 *	so that this procedure is noop.
1881 	 */
1882 
1883 	if (skb->pkt_type == PACKET_LOOPBACK)
1884 		goto out;
1885 
1886 	if (!net_eq(dev_net(dev), sock_net(sk)))
1887 		goto out;
1888 
1889 	skb = skb_share_check(skb, GFP_ATOMIC);
1890 	if (skb == NULL)
1891 		goto oom;
1892 
1893 	/* drop any routing info */
1894 	skb_dst_drop(skb);
1895 
1896 	/* drop conntrack reference */
1897 	nf_reset_ct(skb);
1898 
1899 	spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1900 
1901 	skb_push(skb, skb->data - skb_mac_header(skb));
1902 
1903 	/*
1904 	 *	The SOCK_PACKET socket receives _all_ frames.
1905 	 */
1906 
1907 	spkt->spkt_family = dev->type;
1908 	strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1909 	spkt->spkt_protocol = skb->protocol;
1910 
1911 	/*
1912 	 *	Charge the memory to the socket. This is done specifically
1913 	 *	to prevent sockets using all the memory up.
1914 	 */
1915 
1916 	if (sock_queue_rcv_skb(sk, skb) == 0)
1917 		return 0;
1918 
1919 out:
1920 	kfree_skb(skb);
1921 oom:
1922 	return 0;
1923 }
1924 
1925 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1926 {
1927 	int depth;
1928 
1929 	if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1930 	    sock->type == SOCK_RAW) {
1931 		skb_reset_mac_header(skb);
1932 		skb->protocol = dev_parse_header_protocol(skb);
1933 	}
1934 
1935 	/* Move network header to the right position for VLAN tagged packets */
1936 	if (likely(skb->dev->type == ARPHRD_ETHER) &&
1937 	    eth_type_vlan(skb->protocol) &&
1938 	    __vlan_get_protocol(skb, skb->protocol, &depth) != 0) {
1939 		if (pskb_may_pull(skb, depth))
1940 			skb_set_network_header(skb, depth);
1941 	}
1942 
1943 	skb_probe_transport_header(skb);
1944 }
1945 
1946 /*
1947  *	Output a raw packet to a device layer. This bypasses all the other
1948  *	protocol layers and you must therefore supply it with a complete frame
1949  */
1950 
1951 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1952 			       size_t len)
1953 {
1954 	struct sock *sk = sock->sk;
1955 	DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1956 	struct sk_buff *skb = NULL;
1957 	struct net_device *dev;
1958 	struct sockcm_cookie sockc;
1959 	__be16 proto = 0;
1960 	int err;
1961 	int extra_len = 0;
1962 
1963 	/*
1964 	 *	Get and verify the address.
1965 	 */
1966 
1967 	if (saddr) {
1968 		if (msg->msg_namelen < sizeof(struct sockaddr))
1969 			return -EINVAL;
1970 		if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1971 			proto = saddr->spkt_protocol;
1972 	} else
1973 		return -ENOTCONN;	/* SOCK_PACKET must be sent giving an address */
1974 
1975 	/*
1976 	 *	Find the device first to size check it
1977 	 */
1978 
1979 	saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1980 retry:
1981 	rcu_read_lock();
1982 	dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1983 	err = -ENODEV;
1984 	if (dev == NULL)
1985 		goto out_unlock;
1986 
1987 	err = -ENETDOWN;
1988 	if (!(dev->flags & IFF_UP))
1989 		goto out_unlock;
1990 
1991 	/*
1992 	 * You may not queue a frame bigger than the mtu. This is the lowest level
1993 	 * raw protocol and you must do your own fragmentation at this level.
1994 	 */
1995 
1996 	if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1997 		if (!netif_supports_nofcs(dev)) {
1998 			err = -EPROTONOSUPPORT;
1999 			goto out_unlock;
2000 		}
2001 		extra_len = 4; /* We're doing our own CRC */
2002 	}
2003 
2004 	err = -EMSGSIZE;
2005 	if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
2006 		goto out_unlock;
2007 
2008 	if (!skb) {
2009 		size_t reserved = LL_RESERVED_SPACE(dev);
2010 		int tlen = dev->needed_tailroom;
2011 		unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
2012 
2013 		rcu_read_unlock();
2014 		skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
2015 		if (skb == NULL)
2016 			return -ENOBUFS;
2017 		/* FIXME: Save some space for broken drivers that write a hard
2018 		 * header at transmission time by themselves. PPP is the notable
2019 		 * one here. This should really be fixed at the driver level.
2020 		 */
2021 		skb_reserve(skb, reserved);
2022 		skb_reset_network_header(skb);
2023 
2024 		/* Try to align data part correctly */
2025 		if (hhlen) {
2026 			skb->data -= hhlen;
2027 			skb->tail -= hhlen;
2028 			if (len < hhlen)
2029 				skb_reset_network_header(skb);
2030 		}
2031 		err = memcpy_from_msg(skb_put(skb, len), msg, len);
2032 		if (err)
2033 			goto out_free;
2034 		goto retry;
2035 	}
2036 
2037 	if (!dev_validate_header(dev, skb->data, len)) {
2038 		err = -EINVAL;
2039 		goto out_unlock;
2040 	}
2041 	if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
2042 	    !packet_extra_vlan_len_allowed(dev, skb)) {
2043 		err = -EMSGSIZE;
2044 		goto out_unlock;
2045 	}
2046 
2047 	sockcm_init(&sockc, sk);
2048 	if (msg->msg_controllen) {
2049 		err = sock_cmsg_send(sk, msg, &sockc);
2050 		if (unlikely(err))
2051 			goto out_unlock;
2052 	}
2053 
2054 	skb->protocol = proto;
2055 	skb->dev = dev;
2056 	skb->priority = sk->sk_priority;
2057 	skb->mark = sk->sk_mark;
2058 	skb->tstamp = sockc.transmit_time;
2059 
2060 	skb_setup_tx_timestamp(skb, sockc.tsflags);
2061 
2062 	if (unlikely(extra_len == 4))
2063 		skb->no_fcs = 1;
2064 
2065 	packet_parse_headers(skb, sock);
2066 
2067 	dev_queue_xmit(skb);
2068 	rcu_read_unlock();
2069 	return len;
2070 
2071 out_unlock:
2072 	rcu_read_unlock();
2073 out_free:
2074 	kfree_skb(skb);
2075 	return err;
2076 }
2077 
2078 static unsigned int run_filter(struct sk_buff *skb,
2079 			       const struct sock *sk,
2080 			       unsigned int res)
2081 {
2082 	struct sk_filter *filter;
2083 
2084 	rcu_read_lock();
2085 	filter = rcu_dereference(sk->sk_filter);
2086 	if (filter != NULL)
2087 		res = bpf_prog_run_clear_cb(filter->prog, skb);
2088 	rcu_read_unlock();
2089 
2090 	return res;
2091 }
2092 
2093 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2094 			   size_t *len)
2095 {
2096 	struct virtio_net_hdr vnet_hdr;
2097 
2098 	if (*len < sizeof(vnet_hdr))
2099 		return -EINVAL;
2100 	*len -= sizeof(vnet_hdr);
2101 
2102 	if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0))
2103 		return -EINVAL;
2104 
2105 	return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2106 }
2107 
2108 /*
2109  * This function makes lazy skb cloning in hope that most of packets
2110  * are discarded by BPF.
2111  *
2112  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2113  * and skb->cb are mangled. It works because (and until) packets
2114  * falling here are owned by current CPU. Output packets are cloned
2115  * by dev_queue_xmit_nit(), input packets are processed by net_bh
2116  * sequentially, so that if we return skb to original state on exit,
2117  * we will not harm anyone.
2118  */
2119 
2120 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2121 		      struct packet_type *pt, struct net_device *orig_dev)
2122 {
2123 	struct sock *sk;
2124 	struct sockaddr_ll *sll;
2125 	struct packet_sock *po;
2126 	u8 *skb_head = skb->data;
2127 	int skb_len = skb->len;
2128 	unsigned int snaplen, res;
2129 	bool is_drop_n_account = false;
2130 
2131 	if (skb->pkt_type == PACKET_LOOPBACK)
2132 		goto drop;
2133 
2134 	sk = pt->af_packet_priv;
2135 	po = pkt_sk(sk);
2136 
2137 	if (!net_eq(dev_net(dev), sock_net(sk)))
2138 		goto drop;
2139 
2140 	skb->dev = dev;
2141 
2142 	if (dev_has_header(dev)) {
2143 		/* The device has an explicit notion of ll header,
2144 		 * exported to higher levels.
2145 		 *
2146 		 * Otherwise, the device hides details of its frame
2147 		 * structure, so that corresponding packet head is
2148 		 * never delivered to user.
2149 		 */
2150 		if (sk->sk_type != SOCK_DGRAM)
2151 			skb_push(skb, skb->data - skb_mac_header(skb));
2152 		else if (skb->pkt_type == PACKET_OUTGOING) {
2153 			/* Special case: outgoing packets have ll header at head */
2154 			skb_pull(skb, skb_network_offset(skb));
2155 		}
2156 	}
2157 
2158 	snaplen = skb->len;
2159 
2160 	res = run_filter(skb, sk, snaplen);
2161 	if (!res)
2162 		goto drop_n_restore;
2163 	if (snaplen > res)
2164 		snaplen = res;
2165 
2166 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2167 		goto drop_n_acct;
2168 
2169 	if (skb_shared(skb)) {
2170 		struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2171 		if (nskb == NULL)
2172 			goto drop_n_acct;
2173 
2174 		if (skb_head != skb->data) {
2175 			skb->data = skb_head;
2176 			skb->len = skb_len;
2177 		}
2178 		consume_skb(skb);
2179 		skb = nskb;
2180 	}
2181 
2182 	sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2183 
2184 	sll = &PACKET_SKB_CB(skb)->sa.ll;
2185 	sll->sll_hatype = dev->type;
2186 	sll->sll_pkttype = skb->pkt_type;
2187 	if (unlikely(po->origdev))
2188 		sll->sll_ifindex = orig_dev->ifindex;
2189 	else
2190 		sll->sll_ifindex = dev->ifindex;
2191 
2192 	sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2193 
2194 	/* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2195 	 * Use their space for storing the original skb length.
2196 	 */
2197 	PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2198 
2199 	if (pskb_trim(skb, snaplen))
2200 		goto drop_n_acct;
2201 
2202 	skb_set_owner_r(skb, sk);
2203 	skb->dev = NULL;
2204 	skb_dst_drop(skb);
2205 
2206 	/* drop conntrack reference */
2207 	nf_reset_ct(skb);
2208 
2209 	spin_lock(&sk->sk_receive_queue.lock);
2210 	po->stats.stats1.tp_packets++;
2211 	sock_skb_set_dropcount(sk, skb);
2212 	skb_clear_delivery_time(skb);
2213 	__skb_queue_tail(&sk->sk_receive_queue, skb);
2214 	spin_unlock(&sk->sk_receive_queue.lock);
2215 	sk->sk_data_ready(sk);
2216 	return 0;
2217 
2218 drop_n_acct:
2219 	is_drop_n_account = true;
2220 	atomic_inc(&po->tp_drops);
2221 	atomic_inc(&sk->sk_drops);
2222 
2223 drop_n_restore:
2224 	if (skb_head != skb->data && skb_shared(skb)) {
2225 		skb->data = skb_head;
2226 		skb->len = skb_len;
2227 	}
2228 drop:
2229 	if (!is_drop_n_account)
2230 		consume_skb(skb);
2231 	else
2232 		kfree_skb(skb);
2233 	return 0;
2234 }
2235 
2236 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2237 		       struct packet_type *pt, struct net_device *orig_dev)
2238 {
2239 	struct sock *sk;
2240 	struct packet_sock *po;
2241 	struct sockaddr_ll *sll;
2242 	union tpacket_uhdr h;
2243 	u8 *skb_head = skb->data;
2244 	int skb_len = skb->len;
2245 	unsigned int snaplen, res;
2246 	unsigned long status = TP_STATUS_USER;
2247 	unsigned short macoff, hdrlen;
2248 	unsigned int netoff;
2249 	struct sk_buff *copy_skb = NULL;
2250 	struct timespec64 ts;
2251 	__u32 ts_status;
2252 	bool is_drop_n_account = false;
2253 	unsigned int slot_id = 0;
2254 	bool do_vnet = false;
2255 
2256 	/* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2257 	 * We may add members to them until current aligned size without forcing
2258 	 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2259 	 */
2260 	BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2261 	BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2262 
2263 	if (skb->pkt_type == PACKET_LOOPBACK)
2264 		goto drop;
2265 
2266 	sk = pt->af_packet_priv;
2267 	po = pkt_sk(sk);
2268 
2269 	if (!net_eq(dev_net(dev), sock_net(sk)))
2270 		goto drop;
2271 
2272 	if (dev_has_header(dev)) {
2273 		if (sk->sk_type != SOCK_DGRAM)
2274 			skb_push(skb, skb->data - skb_mac_header(skb));
2275 		else if (skb->pkt_type == PACKET_OUTGOING) {
2276 			/* Special case: outgoing packets have ll header at head */
2277 			skb_pull(skb, skb_network_offset(skb));
2278 		}
2279 	}
2280 
2281 	snaplen = skb->len;
2282 
2283 	res = run_filter(skb, sk, snaplen);
2284 	if (!res)
2285 		goto drop_n_restore;
2286 
2287 	/* If we are flooded, just give up */
2288 	if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2289 		atomic_inc(&po->tp_drops);
2290 		goto drop_n_restore;
2291 	}
2292 
2293 	if (skb->ip_summed == CHECKSUM_PARTIAL)
2294 		status |= TP_STATUS_CSUMNOTREADY;
2295 	else if (skb->pkt_type != PACKET_OUTGOING &&
2296 		 (skb->ip_summed == CHECKSUM_COMPLETE ||
2297 		  skb_csum_unnecessary(skb)))
2298 		status |= TP_STATUS_CSUM_VALID;
2299 
2300 	if (snaplen > res)
2301 		snaplen = res;
2302 
2303 	if (sk->sk_type == SOCK_DGRAM) {
2304 		macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2305 				  po->tp_reserve;
2306 	} else {
2307 		unsigned int maclen = skb_network_offset(skb);
2308 		netoff = TPACKET_ALIGN(po->tp_hdrlen +
2309 				       (maclen < 16 ? 16 : maclen)) +
2310 				       po->tp_reserve;
2311 		if (po->has_vnet_hdr) {
2312 			netoff += sizeof(struct virtio_net_hdr);
2313 			do_vnet = true;
2314 		}
2315 		macoff = netoff - maclen;
2316 	}
2317 	if (netoff > USHRT_MAX) {
2318 		atomic_inc(&po->tp_drops);
2319 		goto drop_n_restore;
2320 	}
2321 	if (po->tp_version <= TPACKET_V2) {
2322 		if (macoff + snaplen > po->rx_ring.frame_size) {
2323 			if (po->copy_thresh &&
2324 			    atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2325 				if (skb_shared(skb)) {
2326 					copy_skb = skb_clone(skb, GFP_ATOMIC);
2327 				} else {
2328 					copy_skb = skb_get(skb);
2329 					skb_head = skb->data;
2330 				}
2331 				if (copy_skb) {
2332 					memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0,
2333 					       sizeof(PACKET_SKB_CB(copy_skb)->sa.ll));
2334 					skb_set_owner_r(copy_skb, sk);
2335 				}
2336 			}
2337 			snaplen = po->rx_ring.frame_size - macoff;
2338 			if ((int)snaplen < 0) {
2339 				snaplen = 0;
2340 				do_vnet = false;
2341 			}
2342 		}
2343 	} else if (unlikely(macoff + snaplen >
2344 			    GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2345 		u32 nval;
2346 
2347 		nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2348 		pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2349 			    snaplen, nval, macoff);
2350 		snaplen = nval;
2351 		if (unlikely((int)snaplen < 0)) {
2352 			snaplen = 0;
2353 			macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2354 			do_vnet = false;
2355 		}
2356 	}
2357 	spin_lock(&sk->sk_receive_queue.lock);
2358 	h.raw = packet_current_rx_frame(po, skb,
2359 					TP_STATUS_KERNEL, (macoff+snaplen));
2360 	if (!h.raw)
2361 		goto drop_n_account;
2362 
2363 	if (po->tp_version <= TPACKET_V2) {
2364 		slot_id = po->rx_ring.head;
2365 		if (test_bit(slot_id, po->rx_ring.rx_owner_map))
2366 			goto drop_n_account;
2367 		__set_bit(slot_id, po->rx_ring.rx_owner_map);
2368 	}
2369 
2370 	if (do_vnet &&
2371 	    virtio_net_hdr_from_skb(skb, h.raw + macoff -
2372 				    sizeof(struct virtio_net_hdr),
2373 				    vio_le(), true, 0)) {
2374 		if (po->tp_version == TPACKET_V3)
2375 			prb_clear_blk_fill_status(&po->rx_ring);
2376 		goto drop_n_account;
2377 	}
2378 
2379 	if (po->tp_version <= TPACKET_V2) {
2380 		packet_increment_rx_head(po, &po->rx_ring);
2381 	/*
2382 	 * LOSING will be reported till you read the stats,
2383 	 * because it's COR - Clear On Read.
2384 	 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2385 	 * at packet level.
2386 	 */
2387 		if (atomic_read(&po->tp_drops))
2388 			status |= TP_STATUS_LOSING;
2389 	}
2390 
2391 	po->stats.stats1.tp_packets++;
2392 	if (copy_skb) {
2393 		status |= TP_STATUS_COPY;
2394 		skb_clear_delivery_time(copy_skb);
2395 		__skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2396 	}
2397 	spin_unlock(&sk->sk_receive_queue.lock);
2398 
2399 	skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2400 
2401 	/* Always timestamp; prefer an existing software timestamp taken
2402 	 * closer to the time of capture.
2403 	 */
2404 	ts_status = tpacket_get_timestamp(skb, &ts,
2405 					  po->tp_tstamp | SOF_TIMESTAMPING_SOFTWARE);
2406 	if (!ts_status)
2407 		ktime_get_real_ts64(&ts);
2408 
2409 	status |= ts_status;
2410 
2411 	switch (po->tp_version) {
2412 	case TPACKET_V1:
2413 		h.h1->tp_len = skb->len;
2414 		h.h1->tp_snaplen = snaplen;
2415 		h.h1->tp_mac = macoff;
2416 		h.h1->tp_net = netoff;
2417 		h.h1->tp_sec = ts.tv_sec;
2418 		h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2419 		hdrlen = sizeof(*h.h1);
2420 		break;
2421 	case TPACKET_V2:
2422 		h.h2->tp_len = skb->len;
2423 		h.h2->tp_snaplen = snaplen;
2424 		h.h2->tp_mac = macoff;
2425 		h.h2->tp_net = netoff;
2426 		h.h2->tp_sec = ts.tv_sec;
2427 		h.h2->tp_nsec = ts.tv_nsec;
2428 		if (skb_vlan_tag_present(skb)) {
2429 			h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2430 			h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2431 			status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2432 		} else {
2433 			h.h2->tp_vlan_tci = 0;
2434 			h.h2->tp_vlan_tpid = 0;
2435 		}
2436 		memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2437 		hdrlen = sizeof(*h.h2);
2438 		break;
2439 	case TPACKET_V3:
2440 		/* tp_nxt_offset,vlan are already populated above.
2441 		 * So DONT clear those fields here
2442 		 */
2443 		h.h3->tp_status |= status;
2444 		h.h3->tp_len = skb->len;
2445 		h.h3->tp_snaplen = snaplen;
2446 		h.h3->tp_mac = macoff;
2447 		h.h3->tp_net = netoff;
2448 		h.h3->tp_sec  = ts.tv_sec;
2449 		h.h3->tp_nsec = ts.tv_nsec;
2450 		memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2451 		hdrlen = sizeof(*h.h3);
2452 		break;
2453 	default:
2454 		BUG();
2455 	}
2456 
2457 	sll = h.raw + TPACKET_ALIGN(hdrlen);
2458 	sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2459 	sll->sll_family = AF_PACKET;
2460 	sll->sll_hatype = dev->type;
2461 	sll->sll_protocol = skb->protocol;
2462 	sll->sll_pkttype = skb->pkt_type;
2463 	if (unlikely(po->origdev))
2464 		sll->sll_ifindex = orig_dev->ifindex;
2465 	else
2466 		sll->sll_ifindex = dev->ifindex;
2467 
2468 	smp_mb();
2469 
2470 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2471 	if (po->tp_version <= TPACKET_V2) {
2472 		u8 *start, *end;
2473 
2474 		end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2475 					macoff + snaplen);
2476 
2477 		for (start = h.raw; start < end; start += PAGE_SIZE)
2478 			flush_dcache_page(pgv_to_page(start));
2479 	}
2480 	smp_wmb();
2481 #endif
2482 
2483 	if (po->tp_version <= TPACKET_V2) {
2484 		spin_lock(&sk->sk_receive_queue.lock);
2485 		__packet_set_status(po, h.raw, status);
2486 		__clear_bit(slot_id, po->rx_ring.rx_owner_map);
2487 		spin_unlock(&sk->sk_receive_queue.lock);
2488 		sk->sk_data_ready(sk);
2489 	} else if (po->tp_version == TPACKET_V3) {
2490 		prb_clear_blk_fill_status(&po->rx_ring);
2491 	}
2492 
2493 drop_n_restore:
2494 	if (skb_head != skb->data && skb_shared(skb)) {
2495 		skb->data = skb_head;
2496 		skb->len = skb_len;
2497 	}
2498 drop:
2499 	if (!is_drop_n_account)
2500 		consume_skb(skb);
2501 	else
2502 		kfree_skb(skb);
2503 	return 0;
2504 
2505 drop_n_account:
2506 	spin_unlock(&sk->sk_receive_queue.lock);
2507 	atomic_inc(&po->tp_drops);
2508 	is_drop_n_account = true;
2509 
2510 	sk->sk_data_ready(sk);
2511 	kfree_skb(copy_skb);
2512 	goto drop_n_restore;
2513 }
2514 
2515 static void tpacket_destruct_skb(struct sk_buff *skb)
2516 {
2517 	struct packet_sock *po = pkt_sk(skb->sk);
2518 
2519 	if (likely(po->tx_ring.pg_vec)) {
2520 		void *ph;
2521 		__u32 ts;
2522 
2523 		ph = skb_zcopy_get_nouarg(skb);
2524 		packet_dec_pending(&po->tx_ring);
2525 
2526 		ts = __packet_set_timestamp(po, ph, skb);
2527 		__packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2528 
2529 		if (!packet_read_pending(&po->tx_ring))
2530 			complete(&po->skb_completion);
2531 	}
2532 
2533 	sock_wfree(skb);
2534 }
2535 
2536 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2537 {
2538 	if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2539 	    (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2540 	     __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2541 	      __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2542 		vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2543 			 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2544 			__virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2545 
2546 	if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2547 		return -EINVAL;
2548 
2549 	return 0;
2550 }
2551 
2552 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2553 				 struct virtio_net_hdr *vnet_hdr)
2554 {
2555 	if (*len < sizeof(*vnet_hdr))
2556 		return -EINVAL;
2557 	*len -= sizeof(*vnet_hdr);
2558 
2559 	if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2560 		return -EFAULT;
2561 
2562 	return __packet_snd_vnet_parse(vnet_hdr, *len);
2563 }
2564 
2565 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2566 		void *frame, struct net_device *dev, void *data, int tp_len,
2567 		__be16 proto, unsigned char *addr, int hlen, int copylen,
2568 		const struct sockcm_cookie *sockc)
2569 {
2570 	union tpacket_uhdr ph;
2571 	int to_write, offset, len, nr_frags, len_max;
2572 	struct socket *sock = po->sk.sk_socket;
2573 	struct page *page;
2574 	int err;
2575 
2576 	ph.raw = frame;
2577 
2578 	skb->protocol = proto;
2579 	skb->dev = dev;
2580 	skb->priority = po->sk.sk_priority;
2581 	skb->mark = po->sk.sk_mark;
2582 	skb->tstamp = sockc->transmit_time;
2583 	skb_setup_tx_timestamp(skb, sockc->tsflags);
2584 	skb_zcopy_set_nouarg(skb, ph.raw);
2585 
2586 	skb_reserve(skb, hlen);
2587 	skb_reset_network_header(skb);
2588 
2589 	to_write = tp_len;
2590 
2591 	if (sock->type == SOCK_DGRAM) {
2592 		err = dev_hard_header(skb, dev, ntohs(proto), addr,
2593 				NULL, tp_len);
2594 		if (unlikely(err < 0))
2595 			return -EINVAL;
2596 	} else if (copylen) {
2597 		int hdrlen = min_t(int, copylen, tp_len);
2598 
2599 		skb_push(skb, dev->hard_header_len);
2600 		skb_put(skb, copylen - dev->hard_header_len);
2601 		err = skb_store_bits(skb, 0, data, hdrlen);
2602 		if (unlikely(err))
2603 			return err;
2604 		if (!dev_validate_header(dev, skb->data, hdrlen))
2605 			return -EINVAL;
2606 
2607 		data += hdrlen;
2608 		to_write -= hdrlen;
2609 	}
2610 
2611 	offset = offset_in_page(data);
2612 	len_max = PAGE_SIZE - offset;
2613 	len = ((to_write > len_max) ? len_max : to_write);
2614 
2615 	skb->data_len = to_write;
2616 	skb->len += to_write;
2617 	skb->truesize += to_write;
2618 	refcount_add(to_write, &po->sk.sk_wmem_alloc);
2619 
2620 	while (likely(to_write)) {
2621 		nr_frags = skb_shinfo(skb)->nr_frags;
2622 
2623 		if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2624 			pr_err("Packet exceed the number of skb frags(%lu)\n",
2625 			       MAX_SKB_FRAGS);
2626 			return -EFAULT;
2627 		}
2628 
2629 		page = pgv_to_page(data);
2630 		data += len;
2631 		flush_dcache_page(page);
2632 		get_page(page);
2633 		skb_fill_page_desc(skb, nr_frags, page, offset, len);
2634 		to_write -= len;
2635 		offset = 0;
2636 		len_max = PAGE_SIZE;
2637 		len = ((to_write > len_max) ? len_max : to_write);
2638 	}
2639 
2640 	packet_parse_headers(skb, sock);
2641 
2642 	return tp_len;
2643 }
2644 
2645 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2646 				int size_max, void **data)
2647 {
2648 	union tpacket_uhdr ph;
2649 	int tp_len, off;
2650 
2651 	ph.raw = frame;
2652 
2653 	switch (po->tp_version) {
2654 	case TPACKET_V3:
2655 		if (ph.h3->tp_next_offset != 0) {
2656 			pr_warn_once("variable sized slot not supported");
2657 			return -EINVAL;
2658 		}
2659 		tp_len = ph.h3->tp_len;
2660 		break;
2661 	case TPACKET_V2:
2662 		tp_len = ph.h2->tp_len;
2663 		break;
2664 	default:
2665 		tp_len = ph.h1->tp_len;
2666 		break;
2667 	}
2668 	if (unlikely(tp_len > size_max)) {
2669 		pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2670 		return -EMSGSIZE;
2671 	}
2672 
2673 	if (unlikely(po->tp_tx_has_off)) {
2674 		int off_min, off_max;
2675 
2676 		off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2677 		off_max = po->tx_ring.frame_size - tp_len;
2678 		if (po->sk.sk_type == SOCK_DGRAM) {
2679 			switch (po->tp_version) {
2680 			case TPACKET_V3:
2681 				off = ph.h3->tp_net;
2682 				break;
2683 			case TPACKET_V2:
2684 				off = ph.h2->tp_net;
2685 				break;
2686 			default:
2687 				off = ph.h1->tp_net;
2688 				break;
2689 			}
2690 		} else {
2691 			switch (po->tp_version) {
2692 			case TPACKET_V3:
2693 				off = ph.h3->tp_mac;
2694 				break;
2695 			case TPACKET_V2:
2696 				off = ph.h2->tp_mac;
2697 				break;
2698 			default:
2699 				off = ph.h1->tp_mac;
2700 				break;
2701 			}
2702 		}
2703 		if (unlikely((off < off_min) || (off_max < off)))
2704 			return -EINVAL;
2705 	} else {
2706 		off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2707 	}
2708 
2709 	*data = frame + off;
2710 	return tp_len;
2711 }
2712 
2713 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2714 {
2715 	struct sk_buff *skb = NULL;
2716 	struct net_device *dev;
2717 	struct virtio_net_hdr *vnet_hdr = NULL;
2718 	struct sockcm_cookie sockc;
2719 	__be16 proto;
2720 	int err, reserve = 0;
2721 	void *ph;
2722 	DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2723 	bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2724 	unsigned char *addr = NULL;
2725 	int tp_len, size_max;
2726 	void *data;
2727 	int len_sum = 0;
2728 	int status = TP_STATUS_AVAILABLE;
2729 	int hlen, tlen, copylen = 0;
2730 	long timeo = 0;
2731 
2732 	mutex_lock(&po->pg_vec_lock);
2733 
2734 	/* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2735 	 * we need to confirm it under protection of pg_vec_lock.
2736 	 */
2737 	if (unlikely(!po->tx_ring.pg_vec)) {
2738 		err = -EBUSY;
2739 		goto out;
2740 	}
2741 	if (likely(saddr == NULL)) {
2742 		dev	= packet_cached_dev_get(po);
2743 		proto	= READ_ONCE(po->num);
2744 	} else {
2745 		err = -EINVAL;
2746 		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2747 			goto out;
2748 		if (msg->msg_namelen < (saddr->sll_halen
2749 					+ offsetof(struct sockaddr_ll,
2750 						sll_addr)))
2751 			goto out;
2752 		proto	= saddr->sll_protocol;
2753 		dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2754 		if (po->sk.sk_socket->type == SOCK_DGRAM) {
2755 			if (dev && msg->msg_namelen < dev->addr_len +
2756 				   offsetof(struct sockaddr_ll, sll_addr))
2757 				goto out_put;
2758 			addr = saddr->sll_addr;
2759 		}
2760 	}
2761 
2762 	err = -ENXIO;
2763 	if (unlikely(dev == NULL))
2764 		goto out;
2765 	err = -ENETDOWN;
2766 	if (unlikely(!(dev->flags & IFF_UP)))
2767 		goto out_put;
2768 
2769 	sockcm_init(&sockc, &po->sk);
2770 	if (msg->msg_controllen) {
2771 		err = sock_cmsg_send(&po->sk, msg, &sockc);
2772 		if (unlikely(err))
2773 			goto out_put;
2774 	}
2775 
2776 	if (po->sk.sk_socket->type == SOCK_RAW)
2777 		reserve = dev->hard_header_len;
2778 	size_max = po->tx_ring.frame_size
2779 		- (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2780 
2781 	if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2782 		size_max = dev->mtu + reserve + VLAN_HLEN;
2783 
2784 	reinit_completion(&po->skb_completion);
2785 
2786 	do {
2787 		ph = packet_current_frame(po, &po->tx_ring,
2788 					  TP_STATUS_SEND_REQUEST);
2789 		if (unlikely(ph == NULL)) {
2790 			if (need_wait && skb) {
2791 				timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2792 				timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2793 				if (timeo <= 0) {
2794 					err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2795 					goto out_put;
2796 				}
2797 			}
2798 			/* check for additional frames */
2799 			continue;
2800 		}
2801 
2802 		skb = NULL;
2803 		tp_len = tpacket_parse_header(po, ph, size_max, &data);
2804 		if (tp_len < 0)
2805 			goto tpacket_error;
2806 
2807 		status = TP_STATUS_SEND_REQUEST;
2808 		hlen = LL_RESERVED_SPACE(dev);
2809 		tlen = dev->needed_tailroom;
2810 		if (po->has_vnet_hdr) {
2811 			vnet_hdr = data;
2812 			data += sizeof(*vnet_hdr);
2813 			tp_len -= sizeof(*vnet_hdr);
2814 			if (tp_len < 0 ||
2815 			    __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2816 				tp_len = -EINVAL;
2817 				goto tpacket_error;
2818 			}
2819 			copylen = __virtio16_to_cpu(vio_le(),
2820 						    vnet_hdr->hdr_len);
2821 		}
2822 		copylen = max_t(int, copylen, dev->hard_header_len);
2823 		skb = sock_alloc_send_skb(&po->sk,
2824 				hlen + tlen + sizeof(struct sockaddr_ll) +
2825 				(copylen - dev->hard_header_len),
2826 				!need_wait, &err);
2827 
2828 		if (unlikely(skb == NULL)) {
2829 			/* we assume the socket was initially writeable ... */
2830 			if (likely(len_sum > 0))
2831 				err = len_sum;
2832 			goto out_status;
2833 		}
2834 		tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2835 					  addr, hlen, copylen, &sockc);
2836 		if (likely(tp_len >= 0) &&
2837 		    tp_len > dev->mtu + reserve &&
2838 		    !po->has_vnet_hdr &&
2839 		    !packet_extra_vlan_len_allowed(dev, skb))
2840 			tp_len = -EMSGSIZE;
2841 
2842 		if (unlikely(tp_len < 0)) {
2843 tpacket_error:
2844 			if (po->tp_loss) {
2845 				__packet_set_status(po, ph,
2846 						TP_STATUS_AVAILABLE);
2847 				packet_increment_head(&po->tx_ring);
2848 				kfree_skb(skb);
2849 				continue;
2850 			} else {
2851 				status = TP_STATUS_WRONG_FORMAT;
2852 				err = tp_len;
2853 				goto out_status;
2854 			}
2855 		}
2856 
2857 		if (po->has_vnet_hdr) {
2858 			if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2859 				tp_len = -EINVAL;
2860 				goto tpacket_error;
2861 			}
2862 			virtio_net_hdr_set_proto(skb, vnet_hdr);
2863 		}
2864 
2865 		skb->destructor = tpacket_destruct_skb;
2866 		__packet_set_status(po, ph, TP_STATUS_SENDING);
2867 		packet_inc_pending(&po->tx_ring);
2868 
2869 		status = TP_STATUS_SEND_REQUEST;
2870 		err = po->xmit(skb);
2871 		if (unlikely(err != 0)) {
2872 			if (err > 0)
2873 				err = net_xmit_errno(err);
2874 			if (err && __packet_get_status(po, ph) ==
2875 				   TP_STATUS_AVAILABLE) {
2876 				/* skb was destructed already */
2877 				skb = NULL;
2878 				goto out_status;
2879 			}
2880 			/*
2881 			 * skb was dropped but not destructed yet;
2882 			 * let's treat it like congestion or err < 0
2883 			 */
2884 			err = 0;
2885 		}
2886 		packet_increment_head(&po->tx_ring);
2887 		len_sum += tp_len;
2888 	} while (likely((ph != NULL) ||
2889 		/* Note: packet_read_pending() might be slow if we have
2890 		 * to call it as it's per_cpu variable, but in fast-path
2891 		 * we already short-circuit the loop with the first
2892 		 * condition, and luckily don't have to go that path
2893 		 * anyway.
2894 		 */
2895 		 (need_wait && packet_read_pending(&po->tx_ring))));
2896 
2897 	err = len_sum;
2898 	goto out_put;
2899 
2900 out_status:
2901 	__packet_set_status(po, ph, status);
2902 	kfree_skb(skb);
2903 out_put:
2904 	dev_put(dev);
2905 out:
2906 	mutex_unlock(&po->pg_vec_lock);
2907 	return err;
2908 }
2909 
2910 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2911 				        size_t reserve, size_t len,
2912 				        size_t linear, int noblock,
2913 				        int *err)
2914 {
2915 	struct sk_buff *skb;
2916 
2917 	/* Under a page?  Don't bother with paged skb. */
2918 	if (prepad + len < PAGE_SIZE || !linear)
2919 		linear = len;
2920 
2921 	skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2922 				   err, 0);
2923 	if (!skb)
2924 		return NULL;
2925 
2926 	skb_reserve(skb, reserve);
2927 	skb_put(skb, linear);
2928 	skb->data_len = len - linear;
2929 	skb->len += len - linear;
2930 
2931 	return skb;
2932 }
2933 
2934 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2935 {
2936 	struct sock *sk = sock->sk;
2937 	DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2938 	struct sk_buff *skb;
2939 	struct net_device *dev;
2940 	__be16 proto;
2941 	unsigned char *addr = NULL;
2942 	int err, reserve = 0;
2943 	struct sockcm_cookie sockc;
2944 	struct virtio_net_hdr vnet_hdr = { 0 };
2945 	int offset = 0;
2946 	struct packet_sock *po = pkt_sk(sk);
2947 	bool has_vnet_hdr = false;
2948 	int hlen, tlen, linear;
2949 	int extra_len = 0;
2950 
2951 	/*
2952 	 *	Get and verify the address.
2953 	 */
2954 
2955 	if (likely(saddr == NULL)) {
2956 		dev	= packet_cached_dev_get(po);
2957 		proto	= READ_ONCE(po->num);
2958 	} else {
2959 		err = -EINVAL;
2960 		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2961 			goto out;
2962 		if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2963 			goto out;
2964 		proto	= saddr->sll_protocol;
2965 		dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2966 		if (sock->type == SOCK_DGRAM) {
2967 			if (dev && msg->msg_namelen < dev->addr_len +
2968 				   offsetof(struct sockaddr_ll, sll_addr))
2969 				goto out_unlock;
2970 			addr = saddr->sll_addr;
2971 		}
2972 	}
2973 
2974 	err = -ENXIO;
2975 	if (unlikely(dev == NULL))
2976 		goto out_unlock;
2977 	err = -ENETDOWN;
2978 	if (unlikely(!(dev->flags & IFF_UP)))
2979 		goto out_unlock;
2980 
2981 	sockcm_init(&sockc, sk);
2982 	sockc.mark = sk->sk_mark;
2983 	if (msg->msg_controllen) {
2984 		err = sock_cmsg_send(sk, msg, &sockc);
2985 		if (unlikely(err))
2986 			goto out_unlock;
2987 	}
2988 
2989 	if (sock->type == SOCK_RAW)
2990 		reserve = dev->hard_header_len;
2991 	if (po->has_vnet_hdr) {
2992 		err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2993 		if (err)
2994 			goto out_unlock;
2995 		has_vnet_hdr = true;
2996 	}
2997 
2998 	if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2999 		if (!netif_supports_nofcs(dev)) {
3000 			err = -EPROTONOSUPPORT;
3001 			goto out_unlock;
3002 		}
3003 		extra_len = 4; /* We're doing our own CRC */
3004 	}
3005 
3006 	err = -EMSGSIZE;
3007 	if (!vnet_hdr.gso_type &&
3008 	    (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
3009 		goto out_unlock;
3010 
3011 	err = -ENOBUFS;
3012 	hlen = LL_RESERVED_SPACE(dev);
3013 	tlen = dev->needed_tailroom;
3014 	linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
3015 	linear = max(linear, min_t(int, len, dev->hard_header_len));
3016 	skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
3017 			       msg->msg_flags & MSG_DONTWAIT, &err);
3018 	if (skb == NULL)
3019 		goto out_unlock;
3020 
3021 	skb_reset_network_header(skb);
3022 
3023 	err = -EINVAL;
3024 	if (sock->type == SOCK_DGRAM) {
3025 		offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
3026 		if (unlikely(offset < 0))
3027 			goto out_free;
3028 	} else if (reserve) {
3029 		skb_reserve(skb, -reserve);
3030 		if (len < reserve + sizeof(struct ipv6hdr) &&
3031 		    dev->min_header_len != dev->hard_header_len)
3032 			skb_reset_network_header(skb);
3033 	}
3034 
3035 	/* Returns -EFAULT on error */
3036 	err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
3037 	if (err)
3038 		goto out_free;
3039 
3040 	if ((sock->type == SOCK_RAW &&
3041 	     !dev_validate_header(dev, skb->data, len)) || !skb->len) {
3042 		err = -EINVAL;
3043 		goto out_free;
3044 	}
3045 
3046 	skb_setup_tx_timestamp(skb, sockc.tsflags);
3047 
3048 	if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
3049 	    !packet_extra_vlan_len_allowed(dev, skb)) {
3050 		err = -EMSGSIZE;
3051 		goto out_free;
3052 	}
3053 
3054 	skb->protocol = proto;
3055 	skb->dev = dev;
3056 	skb->priority = sk->sk_priority;
3057 	skb->mark = sockc.mark;
3058 	skb->tstamp = sockc.transmit_time;
3059 
3060 	if (unlikely(extra_len == 4))
3061 		skb->no_fcs = 1;
3062 
3063 	packet_parse_headers(skb, sock);
3064 
3065 	if (has_vnet_hdr) {
3066 		err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
3067 		if (err)
3068 			goto out_free;
3069 		len += sizeof(vnet_hdr);
3070 		virtio_net_hdr_set_proto(skb, &vnet_hdr);
3071 	}
3072 
3073 	err = po->xmit(skb);
3074 	if (unlikely(err != 0)) {
3075 		if (err > 0)
3076 			err = net_xmit_errno(err);
3077 		if (err)
3078 			goto out_unlock;
3079 	}
3080 
3081 	dev_put(dev);
3082 
3083 	return len;
3084 
3085 out_free:
3086 	kfree_skb(skb);
3087 out_unlock:
3088 	dev_put(dev);
3089 out:
3090 	return err;
3091 }
3092 
3093 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
3094 {
3095 	struct sock *sk = sock->sk;
3096 	struct packet_sock *po = pkt_sk(sk);
3097 
3098 	/* Reading tx_ring.pg_vec without holding pg_vec_lock is racy.
3099 	 * tpacket_snd() will redo the check safely.
3100 	 */
3101 	if (data_race(po->tx_ring.pg_vec))
3102 		return tpacket_snd(po, msg);
3103 
3104 	return packet_snd(sock, msg, len);
3105 }
3106 
3107 /*
3108  *	Close a PACKET socket. This is fairly simple. We immediately go
3109  *	to 'closed' state and remove our protocol entry in the device list.
3110  */
3111 
3112 static int packet_release(struct socket *sock)
3113 {
3114 	struct sock *sk = sock->sk;
3115 	struct packet_sock *po;
3116 	struct packet_fanout *f;
3117 	struct net *net;
3118 	union tpacket_req_u req_u;
3119 
3120 	if (!sk)
3121 		return 0;
3122 
3123 	net = sock_net(sk);
3124 	po = pkt_sk(sk);
3125 
3126 	mutex_lock(&net->packet.sklist_lock);
3127 	sk_del_node_init_rcu(sk);
3128 	mutex_unlock(&net->packet.sklist_lock);
3129 
3130 	sock_prot_inuse_add(net, sk->sk_prot, -1);
3131 
3132 	spin_lock(&po->bind_lock);
3133 	unregister_prot_hook(sk, false);
3134 	packet_cached_dev_reset(po);
3135 
3136 	if (po->prot_hook.dev) {
3137 		netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker);
3138 		po->prot_hook.dev = NULL;
3139 	}
3140 	spin_unlock(&po->bind_lock);
3141 
3142 	packet_flush_mclist(sk);
3143 
3144 	lock_sock(sk);
3145 	if (po->rx_ring.pg_vec) {
3146 		memset(&req_u, 0, sizeof(req_u));
3147 		packet_set_ring(sk, &req_u, 1, 0);
3148 	}
3149 
3150 	if (po->tx_ring.pg_vec) {
3151 		memset(&req_u, 0, sizeof(req_u));
3152 		packet_set_ring(sk, &req_u, 1, 1);
3153 	}
3154 	release_sock(sk);
3155 
3156 	f = fanout_release(sk);
3157 
3158 	synchronize_net();
3159 
3160 	kfree(po->rollover);
3161 	if (f) {
3162 		fanout_release_data(f);
3163 		kvfree(f);
3164 	}
3165 	/*
3166 	 *	Now the socket is dead. No more input will appear.
3167 	 */
3168 	sock_orphan(sk);
3169 	sock->sk = NULL;
3170 
3171 	/* Purge queues */
3172 
3173 	skb_queue_purge(&sk->sk_receive_queue);
3174 	packet_free_pending(po);
3175 	sk_refcnt_debug_release(sk);
3176 
3177 	sock_put(sk);
3178 	return 0;
3179 }
3180 
3181 /*
3182  *	Attach a packet hook.
3183  */
3184 
3185 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3186 			  __be16 proto)
3187 {
3188 	struct packet_sock *po = pkt_sk(sk);
3189 	struct net_device *dev = NULL;
3190 	bool unlisted = false;
3191 	bool need_rehook;
3192 	int ret = 0;
3193 
3194 	lock_sock(sk);
3195 	spin_lock(&po->bind_lock);
3196 	rcu_read_lock();
3197 
3198 	if (po->fanout) {
3199 		ret = -EINVAL;
3200 		goto out_unlock;
3201 	}
3202 
3203 	if (name) {
3204 		dev = dev_get_by_name_rcu(sock_net(sk), name);
3205 		if (!dev) {
3206 			ret = -ENODEV;
3207 			goto out_unlock;
3208 		}
3209 	} else if (ifindex) {
3210 		dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3211 		if (!dev) {
3212 			ret = -ENODEV;
3213 			goto out_unlock;
3214 		}
3215 	}
3216 
3217 	need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev;
3218 
3219 	if (need_rehook) {
3220 		dev_hold(dev);
3221 		if (po->running) {
3222 			rcu_read_unlock();
3223 			/* prevents packet_notifier() from calling
3224 			 * register_prot_hook()
3225 			 */
3226 			WRITE_ONCE(po->num, 0);
3227 			__unregister_prot_hook(sk, true);
3228 			rcu_read_lock();
3229 			if (dev)
3230 				unlisted = !dev_get_by_index_rcu(sock_net(sk),
3231 								 dev->ifindex);
3232 		}
3233 
3234 		BUG_ON(po->running);
3235 		WRITE_ONCE(po->num, proto);
3236 		po->prot_hook.type = proto;
3237 
3238 		netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker);
3239 
3240 		if (unlikely(unlisted)) {
3241 			po->prot_hook.dev = NULL;
3242 			WRITE_ONCE(po->ifindex, -1);
3243 			packet_cached_dev_reset(po);
3244 		} else {
3245 			netdev_hold(dev, &po->prot_hook.dev_tracker,
3246 				    GFP_ATOMIC);
3247 			po->prot_hook.dev = dev;
3248 			WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0);
3249 			packet_cached_dev_assign(po, dev);
3250 		}
3251 		dev_put(dev);
3252 	}
3253 
3254 	if (proto == 0 || !need_rehook)
3255 		goto out_unlock;
3256 
3257 	if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3258 		register_prot_hook(sk);
3259 	} else {
3260 		sk->sk_err = ENETDOWN;
3261 		if (!sock_flag(sk, SOCK_DEAD))
3262 			sk_error_report(sk);
3263 	}
3264 
3265 out_unlock:
3266 	rcu_read_unlock();
3267 	spin_unlock(&po->bind_lock);
3268 	release_sock(sk);
3269 	return ret;
3270 }
3271 
3272 /*
3273  *	Bind a packet socket to a device
3274  */
3275 
3276 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3277 			    int addr_len)
3278 {
3279 	struct sock *sk = sock->sk;
3280 	char name[sizeof(uaddr->sa_data) + 1];
3281 
3282 	/*
3283 	 *	Check legality
3284 	 */
3285 
3286 	if (addr_len != sizeof(struct sockaddr))
3287 		return -EINVAL;
3288 	/* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3289 	 * zero-terminated.
3290 	 */
3291 	memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3292 	name[sizeof(uaddr->sa_data)] = 0;
3293 
3294 	return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3295 }
3296 
3297 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3298 {
3299 	struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3300 	struct sock *sk = sock->sk;
3301 
3302 	/*
3303 	 *	Check legality
3304 	 */
3305 
3306 	if (addr_len < sizeof(struct sockaddr_ll))
3307 		return -EINVAL;
3308 	if (sll->sll_family != AF_PACKET)
3309 		return -EINVAL;
3310 
3311 	return packet_do_bind(sk, NULL, sll->sll_ifindex,
3312 			      sll->sll_protocol ? : pkt_sk(sk)->num);
3313 }
3314 
3315 static struct proto packet_proto = {
3316 	.name	  = "PACKET",
3317 	.owner	  = THIS_MODULE,
3318 	.obj_size = sizeof(struct packet_sock),
3319 };
3320 
3321 /*
3322  *	Create a packet of type SOCK_PACKET.
3323  */
3324 
3325 static int packet_create(struct net *net, struct socket *sock, int protocol,
3326 			 int kern)
3327 {
3328 	struct sock *sk;
3329 	struct packet_sock *po;
3330 	__be16 proto = (__force __be16)protocol; /* weird, but documented */
3331 	int err;
3332 
3333 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
3334 		return -EPERM;
3335 	if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3336 	    sock->type != SOCK_PACKET)
3337 		return -ESOCKTNOSUPPORT;
3338 
3339 	sock->state = SS_UNCONNECTED;
3340 
3341 	err = -ENOBUFS;
3342 	sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3343 	if (sk == NULL)
3344 		goto out;
3345 
3346 	sock->ops = &packet_ops;
3347 	if (sock->type == SOCK_PACKET)
3348 		sock->ops = &packet_ops_spkt;
3349 
3350 	sock_init_data(sock, sk);
3351 
3352 	po = pkt_sk(sk);
3353 	init_completion(&po->skb_completion);
3354 	sk->sk_family = PF_PACKET;
3355 	po->num = proto;
3356 	po->xmit = dev_queue_xmit;
3357 
3358 	err = packet_alloc_pending(po);
3359 	if (err)
3360 		goto out2;
3361 
3362 	packet_cached_dev_reset(po);
3363 
3364 	sk->sk_destruct = packet_sock_destruct;
3365 	sk_refcnt_debug_inc(sk);
3366 
3367 	/*
3368 	 *	Attach a protocol block
3369 	 */
3370 
3371 	spin_lock_init(&po->bind_lock);
3372 	mutex_init(&po->pg_vec_lock);
3373 	po->rollover = NULL;
3374 	po->prot_hook.func = packet_rcv;
3375 
3376 	if (sock->type == SOCK_PACKET)
3377 		po->prot_hook.func = packet_rcv_spkt;
3378 
3379 	po->prot_hook.af_packet_priv = sk;
3380 	po->prot_hook.af_packet_net = sock_net(sk);
3381 
3382 	if (proto) {
3383 		po->prot_hook.type = proto;
3384 		__register_prot_hook(sk);
3385 	}
3386 
3387 	mutex_lock(&net->packet.sklist_lock);
3388 	sk_add_node_tail_rcu(sk, &net->packet.sklist);
3389 	mutex_unlock(&net->packet.sklist_lock);
3390 
3391 	sock_prot_inuse_add(net, &packet_proto, 1);
3392 
3393 	return 0;
3394 out2:
3395 	sk_free(sk);
3396 out:
3397 	return err;
3398 }
3399 
3400 /*
3401  *	Pull a packet from our receive queue and hand it to the user.
3402  *	If necessary we block.
3403  */
3404 
3405 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3406 			  int flags)
3407 {
3408 	struct sock *sk = sock->sk;
3409 	struct sk_buff *skb;
3410 	int copied, err;
3411 	int vnet_hdr_len = 0;
3412 	unsigned int origlen = 0;
3413 
3414 	err = -EINVAL;
3415 	if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3416 		goto out;
3417 
3418 #if 0
3419 	/* What error should we return now? EUNATTACH? */
3420 	if (pkt_sk(sk)->ifindex < 0)
3421 		return -ENODEV;
3422 #endif
3423 
3424 	if (flags & MSG_ERRQUEUE) {
3425 		err = sock_recv_errqueue(sk, msg, len,
3426 					 SOL_PACKET, PACKET_TX_TIMESTAMP);
3427 		goto out;
3428 	}
3429 
3430 	/*
3431 	 *	Call the generic datagram receiver. This handles all sorts
3432 	 *	of horrible races and re-entrancy so we can forget about it
3433 	 *	in the protocol layers.
3434 	 *
3435 	 *	Now it will return ENETDOWN, if device have just gone down,
3436 	 *	but then it will block.
3437 	 */
3438 
3439 	skb = skb_recv_datagram(sk, flags, &err);
3440 
3441 	/*
3442 	 *	An error occurred so return it. Because skb_recv_datagram()
3443 	 *	handles the blocking we don't see and worry about blocking
3444 	 *	retries.
3445 	 */
3446 
3447 	if (skb == NULL)
3448 		goto out;
3449 
3450 	packet_rcv_try_clear_pressure(pkt_sk(sk));
3451 
3452 	if (pkt_sk(sk)->has_vnet_hdr) {
3453 		err = packet_rcv_vnet(msg, skb, &len);
3454 		if (err)
3455 			goto out_free;
3456 		vnet_hdr_len = sizeof(struct virtio_net_hdr);
3457 	}
3458 
3459 	/* You lose any data beyond the buffer you gave. If it worries
3460 	 * a user program they can ask the device for its MTU
3461 	 * anyway.
3462 	 */
3463 	copied = skb->len;
3464 	if (copied > len) {
3465 		copied = len;
3466 		msg->msg_flags |= MSG_TRUNC;
3467 	}
3468 
3469 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3470 	if (err)
3471 		goto out_free;
3472 
3473 	if (sock->type != SOCK_PACKET) {
3474 		struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3475 
3476 		/* Original length was stored in sockaddr_ll fields */
3477 		origlen = PACKET_SKB_CB(skb)->sa.origlen;
3478 		sll->sll_family = AF_PACKET;
3479 		sll->sll_protocol = skb->protocol;
3480 	}
3481 
3482 	sock_recv_cmsgs(msg, sk, skb);
3483 
3484 	if (msg->msg_name) {
3485 		const size_t max_len = min(sizeof(skb->cb),
3486 					   sizeof(struct sockaddr_storage));
3487 		int copy_len;
3488 
3489 		/* If the address length field is there to be filled
3490 		 * in, we fill it in now.
3491 		 */
3492 		if (sock->type == SOCK_PACKET) {
3493 			__sockaddr_check_size(sizeof(struct sockaddr_pkt));
3494 			msg->msg_namelen = sizeof(struct sockaddr_pkt);
3495 			copy_len = msg->msg_namelen;
3496 		} else {
3497 			struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3498 
3499 			msg->msg_namelen = sll->sll_halen +
3500 				offsetof(struct sockaddr_ll, sll_addr);
3501 			copy_len = msg->msg_namelen;
3502 			if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3503 				memset(msg->msg_name +
3504 				       offsetof(struct sockaddr_ll, sll_addr),
3505 				       0, sizeof(sll->sll_addr));
3506 				msg->msg_namelen = sizeof(struct sockaddr_ll);
3507 			}
3508 		}
3509 		if (WARN_ON_ONCE(copy_len > max_len)) {
3510 			copy_len = max_len;
3511 			msg->msg_namelen = copy_len;
3512 		}
3513 		memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3514 	}
3515 
3516 	if (pkt_sk(sk)->auxdata) {
3517 		struct tpacket_auxdata aux;
3518 
3519 		aux.tp_status = TP_STATUS_USER;
3520 		if (skb->ip_summed == CHECKSUM_PARTIAL)
3521 			aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3522 		else if (skb->pkt_type != PACKET_OUTGOING &&
3523 			 (skb->ip_summed == CHECKSUM_COMPLETE ||
3524 			  skb_csum_unnecessary(skb)))
3525 			aux.tp_status |= TP_STATUS_CSUM_VALID;
3526 
3527 		aux.tp_len = origlen;
3528 		aux.tp_snaplen = skb->len;
3529 		aux.tp_mac = 0;
3530 		aux.tp_net = skb_network_offset(skb);
3531 		if (skb_vlan_tag_present(skb)) {
3532 			aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3533 			aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3534 			aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3535 		} else {
3536 			aux.tp_vlan_tci = 0;
3537 			aux.tp_vlan_tpid = 0;
3538 		}
3539 		put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3540 	}
3541 
3542 	/*
3543 	 *	Free or return the buffer as appropriate. Again this
3544 	 *	hides all the races and re-entrancy issues from us.
3545 	 */
3546 	err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3547 
3548 out_free:
3549 	skb_free_datagram(sk, skb);
3550 out:
3551 	return err;
3552 }
3553 
3554 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3555 			       int peer)
3556 {
3557 	struct net_device *dev;
3558 	struct sock *sk	= sock->sk;
3559 
3560 	if (peer)
3561 		return -EOPNOTSUPP;
3562 
3563 	uaddr->sa_family = AF_PACKET;
3564 	memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3565 	rcu_read_lock();
3566 	dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex));
3567 	if (dev)
3568 		strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3569 	rcu_read_unlock();
3570 
3571 	return sizeof(*uaddr);
3572 }
3573 
3574 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3575 			  int peer)
3576 {
3577 	struct net_device *dev;
3578 	struct sock *sk = sock->sk;
3579 	struct packet_sock *po = pkt_sk(sk);
3580 	DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3581 	int ifindex;
3582 
3583 	if (peer)
3584 		return -EOPNOTSUPP;
3585 
3586 	ifindex = READ_ONCE(po->ifindex);
3587 	sll->sll_family = AF_PACKET;
3588 	sll->sll_ifindex = ifindex;
3589 	sll->sll_protocol = READ_ONCE(po->num);
3590 	sll->sll_pkttype = 0;
3591 	rcu_read_lock();
3592 	dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3593 	if (dev) {
3594 		sll->sll_hatype = dev->type;
3595 		sll->sll_halen = dev->addr_len;
3596 		memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3597 	} else {
3598 		sll->sll_hatype = 0;	/* Bad: we have no ARPHRD_UNSPEC */
3599 		sll->sll_halen = 0;
3600 	}
3601 	rcu_read_unlock();
3602 
3603 	return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3604 }
3605 
3606 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3607 			 int what)
3608 {
3609 	switch (i->type) {
3610 	case PACKET_MR_MULTICAST:
3611 		if (i->alen != dev->addr_len)
3612 			return -EINVAL;
3613 		if (what > 0)
3614 			return dev_mc_add(dev, i->addr);
3615 		else
3616 			return dev_mc_del(dev, i->addr);
3617 		break;
3618 	case PACKET_MR_PROMISC:
3619 		return dev_set_promiscuity(dev, what);
3620 	case PACKET_MR_ALLMULTI:
3621 		return dev_set_allmulti(dev, what);
3622 	case PACKET_MR_UNICAST:
3623 		if (i->alen != dev->addr_len)
3624 			return -EINVAL;
3625 		if (what > 0)
3626 			return dev_uc_add(dev, i->addr);
3627 		else
3628 			return dev_uc_del(dev, i->addr);
3629 		break;
3630 	default:
3631 		break;
3632 	}
3633 	return 0;
3634 }
3635 
3636 static void packet_dev_mclist_delete(struct net_device *dev,
3637 				     struct packet_mclist **mlp)
3638 {
3639 	struct packet_mclist *ml;
3640 
3641 	while ((ml = *mlp) != NULL) {
3642 		if (ml->ifindex == dev->ifindex) {
3643 			packet_dev_mc(dev, ml, -1);
3644 			*mlp = ml->next;
3645 			kfree(ml);
3646 		} else
3647 			mlp = &ml->next;
3648 	}
3649 }
3650 
3651 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3652 {
3653 	struct packet_sock *po = pkt_sk(sk);
3654 	struct packet_mclist *ml, *i;
3655 	struct net_device *dev;
3656 	int err;
3657 
3658 	rtnl_lock();
3659 
3660 	err = -ENODEV;
3661 	dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3662 	if (!dev)
3663 		goto done;
3664 
3665 	err = -EINVAL;
3666 	if (mreq->mr_alen > dev->addr_len)
3667 		goto done;
3668 
3669 	err = -ENOBUFS;
3670 	i = kmalloc(sizeof(*i), GFP_KERNEL);
3671 	if (i == NULL)
3672 		goto done;
3673 
3674 	err = 0;
3675 	for (ml = po->mclist; ml; ml = ml->next) {
3676 		if (ml->ifindex == mreq->mr_ifindex &&
3677 		    ml->type == mreq->mr_type &&
3678 		    ml->alen == mreq->mr_alen &&
3679 		    memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3680 			ml->count++;
3681 			/* Free the new element ... */
3682 			kfree(i);
3683 			goto done;
3684 		}
3685 	}
3686 
3687 	i->type = mreq->mr_type;
3688 	i->ifindex = mreq->mr_ifindex;
3689 	i->alen = mreq->mr_alen;
3690 	memcpy(i->addr, mreq->mr_address, i->alen);
3691 	memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3692 	i->count = 1;
3693 	i->next = po->mclist;
3694 	po->mclist = i;
3695 	err = packet_dev_mc(dev, i, 1);
3696 	if (err) {
3697 		po->mclist = i->next;
3698 		kfree(i);
3699 	}
3700 
3701 done:
3702 	rtnl_unlock();
3703 	return err;
3704 }
3705 
3706 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3707 {
3708 	struct packet_mclist *ml, **mlp;
3709 
3710 	rtnl_lock();
3711 
3712 	for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3713 		if (ml->ifindex == mreq->mr_ifindex &&
3714 		    ml->type == mreq->mr_type &&
3715 		    ml->alen == mreq->mr_alen &&
3716 		    memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3717 			if (--ml->count == 0) {
3718 				struct net_device *dev;
3719 				*mlp = ml->next;
3720 				dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3721 				if (dev)
3722 					packet_dev_mc(dev, ml, -1);
3723 				kfree(ml);
3724 			}
3725 			break;
3726 		}
3727 	}
3728 	rtnl_unlock();
3729 	return 0;
3730 }
3731 
3732 static void packet_flush_mclist(struct sock *sk)
3733 {
3734 	struct packet_sock *po = pkt_sk(sk);
3735 	struct packet_mclist *ml;
3736 
3737 	if (!po->mclist)
3738 		return;
3739 
3740 	rtnl_lock();
3741 	while ((ml = po->mclist) != NULL) {
3742 		struct net_device *dev;
3743 
3744 		po->mclist = ml->next;
3745 		dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3746 		if (dev != NULL)
3747 			packet_dev_mc(dev, ml, -1);
3748 		kfree(ml);
3749 	}
3750 	rtnl_unlock();
3751 }
3752 
3753 static int
3754 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
3755 		  unsigned int optlen)
3756 {
3757 	struct sock *sk = sock->sk;
3758 	struct packet_sock *po = pkt_sk(sk);
3759 	int ret;
3760 
3761 	if (level != SOL_PACKET)
3762 		return -ENOPROTOOPT;
3763 
3764 	switch (optname) {
3765 	case PACKET_ADD_MEMBERSHIP:
3766 	case PACKET_DROP_MEMBERSHIP:
3767 	{
3768 		struct packet_mreq_max mreq;
3769 		int len = optlen;
3770 		memset(&mreq, 0, sizeof(mreq));
3771 		if (len < sizeof(struct packet_mreq))
3772 			return -EINVAL;
3773 		if (len > sizeof(mreq))
3774 			len = sizeof(mreq);
3775 		if (copy_from_sockptr(&mreq, optval, len))
3776 			return -EFAULT;
3777 		if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3778 			return -EINVAL;
3779 		if (optname == PACKET_ADD_MEMBERSHIP)
3780 			ret = packet_mc_add(sk, &mreq);
3781 		else
3782 			ret = packet_mc_drop(sk, &mreq);
3783 		return ret;
3784 	}
3785 
3786 	case PACKET_RX_RING:
3787 	case PACKET_TX_RING:
3788 	{
3789 		union tpacket_req_u req_u;
3790 		int len;
3791 
3792 		lock_sock(sk);
3793 		switch (po->tp_version) {
3794 		case TPACKET_V1:
3795 		case TPACKET_V2:
3796 			len = sizeof(req_u.req);
3797 			break;
3798 		case TPACKET_V3:
3799 		default:
3800 			len = sizeof(req_u.req3);
3801 			break;
3802 		}
3803 		if (optlen < len) {
3804 			ret = -EINVAL;
3805 		} else {
3806 			if (copy_from_sockptr(&req_u.req, optval, len))
3807 				ret = -EFAULT;
3808 			else
3809 				ret = packet_set_ring(sk, &req_u, 0,
3810 						    optname == PACKET_TX_RING);
3811 		}
3812 		release_sock(sk);
3813 		return ret;
3814 	}
3815 	case PACKET_COPY_THRESH:
3816 	{
3817 		int val;
3818 
3819 		if (optlen != sizeof(val))
3820 			return -EINVAL;
3821 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3822 			return -EFAULT;
3823 
3824 		pkt_sk(sk)->copy_thresh = val;
3825 		return 0;
3826 	}
3827 	case PACKET_VERSION:
3828 	{
3829 		int val;
3830 
3831 		if (optlen != sizeof(val))
3832 			return -EINVAL;
3833 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3834 			return -EFAULT;
3835 		switch (val) {
3836 		case TPACKET_V1:
3837 		case TPACKET_V2:
3838 		case TPACKET_V3:
3839 			break;
3840 		default:
3841 			return -EINVAL;
3842 		}
3843 		lock_sock(sk);
3844 		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3845 			ret = -EBUSY;
3846 		} else {
3847 			po->tp_version = val;
3848 			ret = 0;
3849 		}
3850 		release_sock(sk);
3851 		return ret;
3852 	}
3853 	case PACKET_RESERVE:
3854 	{
3855 		unsigned int val;
3856 
3857 		if (optlen != sizeof(val))
3858 			return -EINVAL;
3859 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3860 			return -EFAULT;
3861 		if (val > INT_MAX)
3862 			return -EINVAL;
3863 		lock_sock(sk);
3864 		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3865 			ret = -EBUSY;
3866 		} else {
3867 			po->tp_reserve = val;
3868 			ret = 0;
3869 		}
3870 		release_sock(sk);
3871 		return ret;
3872 	}
3873 	case PACKET_LOSS:
3874 	{
3875 		unsigned int val;
3876 
3877 		if (optlen != sizeof(val))
3878 			return -EINVAL;
3879 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3880 			return -EFAULT;
3881 
3882 		lock_sock(sk);
3883 		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3884 			ret = -EBUSY;
3885 		} else {
3886 			po->tp_loss = !!val;
3887 			ret = 0;
3888 		}
3889 		release_sock(sk);
3890 		return ret;
3891 	}
3892 	case PACKET_AUXDATA:
3893 	{
3894 		int val;
3895 
3896 		if (optlen < sizeof(val))
3897 			return -EINVAL;
3898 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3899 			return -EFAULT;
3900 
3901 		lock_sock(sk);
3902 		po->auxdata = !!val;
3903 		release_sock(sk);
3904 		return 0;
3905 	}
3906 	case PACKET_ORIGDEV:
3907 	{
3908 		int val;
3909 
3910 		if (optlen < sizeof(val))
3911 			return -EINVAL;
3912 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3913 			return -EFAULT;
3914 
3915 		lock_sock(sk);
3916 		po->origdev = !!val;
3917 		release_sock(sk);
3918 		return 0;
3919 	}
3920 	case PACKET_VNET_HDR:
3921 	{
3922 		int val;
3923 
3924 		if (sock->type != SOCK_RAW)
3925 			return -EINVAL;
3926 		if (optlen < sizeof(val))
3927 			return -EINVAL;
3928 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3929 			return -EFAULT;
3930 
3931 		lock_sock(sk);
3932 		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3933 			ret = -EBUSY;
3934 		} else {
3935 			po->has_vnet_hdr = !!val;
3936 			ret = 0;
3937 		}
3938 		release_sock(sk);
3939 		return ret;
3940 	}
3941 	case PACKET_TIMESTAMP:
3942 	{
3943 		int val;
3944 
3945 		if (optlen != sizeof(val))
3946 			return -EINVAL;
3947 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3948 			return -EFAULT;
3949 
3950 		po->tp_tstamp = val;
3951 		return 0;
3952 	}
3953 	case PACKET_FANOUT:
3954 	{
3955 		struct fanout_args args = { 0 };
3956 
3957 		if (optlen != sizeof(int) && optlen != sizeof(args))
3958 			return -EINVAL;
3959 		if (copy_from_sockptr(&args, optval, optlen))
3960 			return -EFAULT;
3961 
3962 		return fanout_add(sk, &args);
3963 	}
3964 	case PACKET_FANOUT_DATA:
3965 	{
3966 		/* Paired with the WRITE_ONCE() in fanout_add() */
3967 		if (!READ_ONCE(po->fanout))
3968 			return -EINVAL;
3969 
3970 		return fanout_set_data(po, optval, optlen);
3971 	}
3972 	case PACKET_IGNORE_OUTGOING:
3973 	{
3974 		int val;
3975 
3976 		if (optlen != sizeof(val))
3977 			return -EINVAL;
3978 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3979 			return -EFAULT;
3980 		if (val < 0 || val > 1)
3981 			return -EINVAL;
3982 
3983 		po->prot_hook.ignore_outgoing = !!val;
3984 		return 0;
3985 	}
3986 	case PACKET_TX_HAS_OFF:
3987 	{
3988 		unsigned int val;
3989 
3990 		if (optlen != sizeof(val))
3991 			return -EINVAL;
3992 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3993 			return -EFAULT;
3994 
3995 		lock_sock(sk);
3996 		if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec)
3997 			po->tp_tx_has_off = !!val;
3998 
3999 		release_sock(sk);
4000 		return 0;
4001 	}
4002 	case PACKET_QDISC_BYPASS:
4003 	{
4004 		int val;
4005 
4006 		if (optlen != sizeof(val))
4007 			return -EINVAL;
4008 		if (copy_from_sockptr(&val, optval, sizeof(val)))
4009 			return -EFAULT;
4010 
4011 		po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
4012 		return 0;
4013 	}
4014 	default:
4015 		return -ENOPROTOOPT;
4016 	}
4017 }
4018 
4019 static int packet_getsockopt(struct socket *sock, int level, int optname,
4020 			     char __user *optval, int __user *optlen)
4021 {
4022 	int len;
4023 	int val, lv = sizeof(val);
4024 	struct sock *sk = sock->sk;
4025 	struct packet_sock *po = pkt_sk(sk);
4026 	void *data = &val;
4027 	union tpacket_stats_u st;
4028 	struct tpacket_rollover_stats rstats;
4029 	int drops;
4030 
4031 	if (level != SOL_PACKET)
4032 		return -ENOPROTOOPT;
4033 
4034 	if (get_user(len, optlen))
4035 		return -EFAULT;
4036 
4037 	if (len < 0)
4038 		return -EINVAL;
4039 
4040 	switch (optname) {
4041 	case PACKET_STATISTICS:
4042 		spin_lock_bh(&sk->sk_receive_queue.lock);
4043 		memcpy(&st, &po->stats, sizeof(st));
4044 		memset(&po->stats, 0, sizeof(po->stats));
4045 		spin_unlock_bh(&sk->sk_receive_queue.lock);
4046 		drops = atomic_xchg(&po->tp_drops, 0);
4047 
4048 		if (po->tp_version == TPACKET_V3) {
4049 			lv = sizeof(struct tpacket_stats_v3);
4050 			st.stats3.tp_drops = drops;
4051 			st.stats3.tp_packets += drops;
4052 			data = &st.stats3;
4053 		} else {
4054 			lv = sizeof(struct tpacket_stats);
4055 			st.stats1.tp_drops = drops;
4056 			st.stats1.tp_packets += drops;
4057 			data = &st.stats1;
4058 		}
4059 
4060 		break;
4061 	case PACKET_AUXDATA:
4062 		val = po->auxdata;
4063 		break;
4064 	case PACKET_ORIGDEV:
4065 		val = po->origdev;
4066 		break;
4067 	case PACKET_VNET_HDR:
4068 		val = po->has_vnet_hdr;
4069 		break;
4070 	case PACKET_VERSION:
4071 		val = po->tp_version;
4072 		break;
4073 	case PACKET_HDRLEN:
4074 		if (len > sizeof(int))
4075 			len = sizeof(int);
4076 		if (len < sizeof(int))
4077 			return -EINVAL;
4078 		if (copy_from_user(&val, optval, len))
4079 			return -EFAULT;
4080 		switch (val) {
4081 		case TPACKET_V1:
4082 			val = sizeof(struct tpacket_hdr);
4083 			break;
4084 		case TPACKET_V2:
4085 			val = sizeof(struct tpacket2_hdr);
4086 			break;
4087 		case TPACKET_V3:
4088 			val = sizeof(struct tpacket3_hdr);
4089 			break;
4090 		default:
4091 			return -EINVAL;
4092 		}
4093 		break;
4094 	case PACKET_RESERVE:
4095 		val = po->tp_reserve;
4096 		break;
4097 	case PACKET_LOSS:
4098 		val = po->tp_loss;
4099 		break;
4100 	case PACKET_TIMESTAMP:
4101 		val = po->tp_tstamp;
4102 		break;
4103 	case PACKET_FANOUT:
4104 		val = (po->fanout ?
4105 		       ((u32)po->fanout->id |
4106 			((u32)po->fanout->type << 16) |
4107 			((u32)po->fanout->flags << 24)) :
4108 		       0);
4109 		break;
4110 	case PACKET_IGNORE_OUTGOING:
4111 		val = po->prot_hook.ignore_outgoing;
4112 		break;
4113 	case PACKET_ROLLOVER_STATS:
4114 		if (!po->rollover)
4115 			return -EINVAL;
4116 		rstats.tp_all = atomic_long_read(&po->rollover->num);
4117 		rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4118 		rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4119 		data = &rstats;
4120 		lv = sizeof(rstats);
4121 		break;
4122 	case PACKET_TX_HAS_OFF:
4123 		val = po->tp_tx_has_off;
4124 		break;
4125 	case PACKET_QDISC_BYPASS:
4126 		val = packet_use_direct_xmit(po);
4127 		break;
4128 	default:
4129 		return -ENOPROTOOPT;
4130 	}
4131 
4132 	if (len > lv)
4133 		len = lv;
4134 	if (put_user(len, optlen))
4135 		return -EFAULT;
4136 	if (copy_to_user(optval, data, len))
4137 		return -EFAULT;
4138 	return 0;
4139 }
4140 
4141 static int packet_notifier(struct notifier_block *this,
4142 			   unsigned long msg, void *ptr)
4143 {
4144 	struct sock *sk;
4145 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4146 	struct net *net = dev_net(dev);
4147 
4148 	rcu_read_lock();
4149 	sk_for_each_rcu(sk, &net->packet.sklist) {
4150 		struct packet_sock *po = pkt_sk(sk);
4151 
4152 		switch (msg) {
4153 		case NETDEV_UNREGISTER:
4154 			if (po->mclist)
4155 				packet_dev_mclist_delete(dev, &po->mclist);
4156 			fallthrough;
4157 
4158 		case NETDEV_DOWN:
4159 			if (dev->ifindex == po->ifindex) {
4160 				spin_lock(&po->bind_lock);
4161 				if (po->running) {
4162 					__unregister_prot_hook(sk, false);
4163 					sk->sk_err = ENETDOWN;
4164 					if (!sock_flag(sk, SOCK_DEAD))
4165 						sk_error_report(sk);
4166 				}
4167 				if (msg == NETDEV_UNREGISTER) {
4168 					packet_cached_dev_reset(po);
4169 					WRITE_ONCE(po->ifindex, -1);
4170 					netdev_put(po->prot_hook.dev,
4171 						   &po->prot_hook.dev_tracker);
4172 					po->prot_hook.dev = NULL;
4173 				}
4174 				spin_unlock(&po->bind_lock);
4175 			}
4176 			break;
4177 		case NETDEV_UP:
4178 			if (dev->ifindex == po->ifindex) {
4179 				spin_lock(&po->bind_lock);
4180 				if (po->num)
4181 					register_prot_hook(sk);
4182 				spin_unlock(&po->bind_lock);
4183 			}
4184 			break;
4185 		}
4186 	}
4187 	rcu_read_unlock();
4188 	return NOTIFY_DONE;
4189 }
4190 
4191 
4192 static int packet_ioctl(struct socket *sock, unsigned int cmd,
4193 			unsigned long arg)
4194 {
4195 	struct sock *sk = sock->sk;
4196 
4197 	switch (cmd) {
4198 	case SIOCOUTQ:
4199 	{
4200 		int amount = sk_wmem_alloc_get(sk);
4201 
4202 		return put_user(amount, (int __user *)arg);
4203 	}
4204 	case SIOCINQ:
4205 	{
4206 		struct sk_buff *skb;
4207 		int amount = 0;
4208 
4209 		spin_lock_bh(&sk->sk_receive_queue.lock);
4210 		skb = skb_peek(&sk->sk_receive_queue);
4211 		if (skb)
4212 			amount = skb->len;
4213 		spin_unlock_bh(&sk->sk_receive_queue.lock);
4214 		return put_user(amount, (int __user *)arg);
4215 	}
4216 #ifdef CONFIG_INET
4217 	case SIOCADDRT:
4218 	case SIOCDELRT:
4219 	case SIOCDARP:
4220 	case SIOCGARP:
4221 	case SIOCSARP:
4222 	case SIOCGIFADDR:
4223 	case SIOCSIFADDR:
4224 	case SIOCGIFBRDADDR:
4225 	case SIOCSIFBRDADDR:
4226 	case SIOCGIFNETMASK:
4227 	case SIOCSIFNETMASK:
4228 	case SIOCGIFDSTADDR:
4229 	case SIOCSIFDSTADDR:
4230 	case SIOCSIFFLAGS:
4231 		return inet_dgram_ops.ioctl(sock, cmd, arg);
4232 #endif
4233 
4234 	default:
4235 		return -ENOIOCTLCMD;
4236 	}
4237 	return 0;
4238 }
4239 
4240 static __poll_t packet_poll(struct file *file, struct socket *sock,
4241 				poll_table *wait)
4242 {
4243 	struct sock *sk = sock->sk;
4244 	struct packet_sock *po = pkt_sk(sk);
4245 	__poll_t mask = datagram_poll(file, sock, wait);
4246 
4247 	spin_lock_bh(&sk->sk_receive_queue.lock);
4248 	if (po->rx_ring.pg_vec) {
4249 		if (!packet_previous_rx_frame(po, &po->rx_ring,
4250 			TP_STATUS_KERNEL))
4251 			mask |= EPOLLIN | EPOLLRDNORM;
4252 	}
4253 	packet_rcv_try_clear_pressure(po);
4254 	spin_unlock_bh(&sk->sk_receive_queue.lock);
4255 	spin_lock_bh(&sk->sk_write_queue.lock);
4256 	if (po->tx_ring.pg_vec) {
4257 		if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4258 			mask |= EPOLLOUT | EPOLLWRNORM;
4259 	}
4260 	spin_unlock_bh(&sk->sk_write_queue.lock);
4261 	return mask;
4262 }
4263 
4264 
4265 /* Dirty? Well, I still did not learn better way to account
4266  * for user mmaps.
4267  */
4268 
4269 static void packet_mm_open(struct vm_area_struct *vma)
4270 {
4271 	struct file *file = vma->vm_file;
4272 	struct socket *sock = file->private_data;
4273 	struct sock *sk = sock->sk;
4274 
4275 	if (sk)
4276 		atomic_inc(&pkt_sk(sk)->mapped);
4277 }
4278 
4279 static void packet_mm_close(struct vm_area_struct *vma)
4280 {
4281 	struct file *file = vma->vm_file;
4282 	struct socket *sock = file->private_data;
4283 	struct sock *sk = sock->sk;
4284 
4285 	if (sk)
4286 		atomic_dec(&pkt_sk(sk)->mapped);
4287 }
4288 
4289 static const struct vm_operations_struct packet_mmap_ops = {
4290 	.open	=	packet_mm_open,
4291 	.close	=	packet_mm_close,
4292 };
4293 
4294 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4295 			unsigned int len)
4296 {
4297 	int i;
4298 
4299 	for (i = 0; i < len; i++) {
4300 		if (likely(pg_vec[i].buffer)) {
4301 			if (is_vmalloc_addr(pg_vec[i].buffer))
4302 				vfree(pg_vec[i].buffer);
4303 			else
4304 				free_pages((unsigned long)pg_vec[i].buffer,
4305 					   order);
4306 			pg_vec[i].buffer = NULL;
4307 		}
4308 	}
4309 	kfree(pg_vec);
4310 }
4311 
4312 static char *alloc_one_pg_vec_page(unsigned long order)
4313 {
4314 	char *buffer;
4315 	gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4316 			  __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4317 
4318 	buffer = (char *) __get_free_pages(gfp_flags, order);
4319 	if (buffer)
4320 		return buffer;
4321 
4322 	/* __get_free_pages failed, fall back to vmalloc */
4323 	buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4324 	if (buffer)
4325 		return buffer;
4326 
4327 	/* vmalloc failed, lets dig into swap here */
4328 	gfp_flags &= ~__GFP_NORETRY;
4329 	buffer = (char *) __get_free_pages(gfp_flags, order);
4330 	if (buffer)
4331 		return buffer;
4332 
4333 	/* complete and utter failure */
4334 	return NULL;
4335 }
4336 
4337 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4338 {
4339 	unsigned int block_nr = req->tp_block_nr;
4340 	struct pgv *pg_vec;
4341 	int i;
4342 
4343 	pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4344 	if (unlikely(!pg_vec))
4345 		goto out;
4346 
4347 	for (i = 0; i < block_nr; i++) {
4348 		pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4349 		if (unlikely(!pg_vec[i].buffer))
4350 			goto out_free_pgvec;
4351 	}
4352 
4353 out:
4354 	return pg_vec;
4355 
4356 out_free_pgvec:
4357 	free_pg_vec(pg_vec, order, block_nr);
4358 	pg_vec = NULL;
4359 	goto out;
4360 }
4361 
4362 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4363 		int closing, int tx_ring)
4364 {
4365 	struct pgv *pg_vec = NULL;
4366 	struct packet_sock *po = pkt_sk(sk);
4367 	unsigned long *rx_owner_map = NULL;
4368 	int was_running, order = 0;
4369 	struct packet_ring_buffer *rb;
4370 	struct sk_buff_head *rb_queue;
4371 	__be16 num;
4372 	int err;
4373 	/* Added to avoid minimal code churn */
4374 	struct tpacket_req *req = &req_u->req;
4375 
4376 	rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4377 	rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4378 
4379 	err = -EBUSY;
4380 	if (!closing) {
4381 		if (atomic_read(&po->mapped))
4382 			goto out;
4383 		if (packet_read_pending(rb))
4384 			goto out;
4385 	}
4386 
4387 	if (req->tp_block_nr) {
4388 		unsigned int min_frame_size;
4389 
4390 		/* Sanity tests and some calculations */
4391 		err = -EBUSY;
4392 		if (unlikely(rb->pg_vec))
4393 			goto out;
4394 
4395 		switch (po->tp_version) {
4396 		case TPACKET_V1:
4397 			po->tp_hdrlen = TPACKET_HDRLEN;
4398 			break;
4399 		case TPACKET_V2:
4400 			po->tp_hdrlen = TPACKET2_HDRLEN;
4401 			break;
4402 		case TPACKET_V3:
4403 			po->tp_hdrlen = TPACKET3_HDRLEN;
4404 			break;
4405 		}
4406 
4407 		err = -EINVAL;
4408 		if (unlikely((int)req->tp_block_size <= 0))
4409 			goto out;
4410 		if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4411 			goto out;
4412 		min_frame_size = po->tp_hdrlen + po->tp_reserve;
4413 		if (po->tp_version >= TPACKET_V3 &&
4414 		    req->tp_block_size <
4415 		    BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4416 			goto out;
4417 		if (unlikely(req->tp_frame_size < min_frame_size))
4418 			goto out;
4419 		if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4420 			goto out;
4421 
4422 		rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4423 		if (unlikely(rb->frames_per_block == 0))
4424 			goto out;
4425 		if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4426 			goto out;
4427 		if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4428 					req->tp_frame_nr))
4429 			goto out;
4430 
4431 		err = -ENOMEM;
4432 		order = get_order(req->tp_block_size);
4433 		pg_vec = alloc_pg_vec(req, order);
4434 		if (unlikely(!pg_vec))
4435 			goto out;
4436 		switch (po->tp_version) {
4437 		case TPACKET_V3:
4438 			/* Block transmit is not supported yet */
4439 			if (!tx_ring) {
4440 				init_prb_bdqc(po, rb, pg_vec, req_u);
4441 			} else {
4442 				struct tpacket_req3 *req3 = &req_u->req3;
4443 
4444 				if (req3->tp_retire_blk_tov ||
4445 				    req3->tp_sizeof_priv ||
4446 				    req3->tp_feature_req_word) {
4447 					err = -EINVAL;
4448 					goto out_free_pg_vec;
4449 				}
4450 			}
4451 			break;
4452 		default:
4453 			if (!tx_ring) {
4454 				rx_owner_map = bitmap_alloc(req->tp_frame_nr,
4455 					GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
4456 				if (!rx_owner_map)
4457 					goto out_free_pg_vec;
4458 			}
4459 			break;
4460 		}
4461 	}
4462 	/* Done */
4463 	else {
4464 		err = -EINVAL;
4465 		if (unlikely(req->tp_frame_nr))
4466 			goto out;
4467 	}
4468 
4469 
4470 	/* Detach socket from network */
4471 	spin_lock(&po->bind_lock);
4472 	was_running = po->running;
4473 	num = po->num;
4474 	if (was_running) {
4475 		WRITE_ONCE(po->num, 0);
4476 		__unregister_prot_hook(sk, false);
4477 	}
4478 	spin_unlock(&po->bind_lock);
4479 
4480 	synchronize_net();
4481 
4482 	err = -EBUSY;
4483 	mutex_lock(&po->pg_vec_lock);
4484 	if (closing || atomic_read(&po->mapped) == 0) {
4485 		err = 0;
4486 		spin_lock_bh(&rb_queue->lock);
4487 		swap(rb->pg_vec, pg_vec);
4488 		if (po->tp_version <= TPACKET_V2)
4489 			swap(rb->rx_owner_map, rx_owner_map);
4490 		rb->frame_max = (req->tp_frame_nr - 1);
4491 		rb->head = 0;
4492 		rb->frame_size = req->tp_frame_size;
4493 		spin_unlock_bh(&rb_queue->lock);
4494 
4495 		swap(rb->pg_vec_order, order);
4496 		swap(rb->pg_vec_len, req->tp_block_nr);
4497 
4498 		rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4499 		po->prot_hook.func = (po->rx_ring.pg_vec) ?
4500 						tpacket_rcv : packet_rcv;
4501 		skb_queue_purge(rb_queue);
4502 		if (atomic_read(&po->mapped))
4503 			pr_err("packet_mmap: vma is busy: %d\n",
4504 			       atomic_read(&po->mapped));
4505 	}
4506 	mutex_unlock(&po->pg_vec_lock);
4507 
4508 	spin_lock(&po->bind_lock);
4509 	if (was_running) {
4510 		WRITE_ONCE(po->num, num);
4511 		register_prot_hook(sk);
4512 	}
4513 	spin_unlock(&po->bind_lock);
4514 	if (pg_vec && (po->tp_version > TPACKET_V2)) {
4515 		/* Because we don't support block-based V3 on tx-ring */
4516 		if (!tx_ring)
4517 			prb_shutdown_retire_blk_timer(po, rb_queue);
4518 	}
4519 
4520 out_free_pg_vec:
4521 	if (pg_vec) {
4522 		bitmap_free(rx_owner_map);
4523 		free_pg_vec(pg_vec, order, req->tp_block_nr);
4524 	}
4525 out:
4526 	return err;
4527 }
4528 
4529 static int packet_mmap(struct file *file, struct socket *sock,
4530 		struct vm_area_struct *vma)
4531 {
4532 	struct sock *sk = sock->sk;
4533 	struct packet_sock *po = pkt_sk(sk);
4534 	unsigned long size, expected_size;
4535 	struct packet_ring_buffer *rb;
4536 	unsigned long start;
4537 	int err = -EINVAL;
4538 	int i;
4539 
4540 	if (vma->vm_pgoff)
4541 		return -EINVAL;
4542 
4543 	mutex_lock(&po->pg_vec_lock);
4544 
4545 	expected_size = 0;
4546 	for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4547 		if (rb->pg_vec) {
4548 			expected_size += rb->pg_vec_len
4549 						* rb->pg_vec_pages
4550 						* PAGE_SIZE;
4551 		}
4552 	}
4553 
4554 	if (expected_size == 0)
4555 		goto out;
4556 
4557 	size = vma->vm_end - vma->vm_start;
4558 	if (size != expected_size)
4559 		goto out;
4560 
4561 	start = vma->vm_start;
4562 	for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4563 		if (rb->pg_vec == NULL)
4564 			continue;
4565 
4566 		for (i = 0; i < rb->pg_vec_len; i++) {
4567 			struct page *page;
4568 			void *kaddr = rb->pg_vec[i].buffer;
4569 			int pg_num;
4570 
4571 			for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4572 				page = pgv_to_page(kaddr);
4573 				err = vm_insert_page(vma, start, page);
4574 				if (unlikely(err))
4575 					goto out;
4576 				start += PAGE_SIZE;
4577 				kaddr += PAGE_SIZE;
4578 			}
4579 		}
4580 	}
4581 
4582 	atomic_inc(&po->mapped);
4583 	vma->vm_ops = &packet_mmap_ops;
4584 	err = 0;
4585 
4586 out:
4587 	mutex_unlock(&po->pg_vec_lock);
4588 	return err;
4589 }
4590 
4591 static const struct proto_ops packet_ops_spkt = {
4592 	.family =	PF_PACKET,
4593 	.owner =	THIS_MODULE,
4594 	.release =	packet_release,
4595 	.bind =		packet_bind_spkt,
4596 	.connect =	sock_no_connect,
4597 	.socketpair =	sock_no_socketpair,
4598 	.accept =	sock_no_accept,
4599 	.getname =	packet_getname_spkt,
4600 	.poll =		datagram_poll,
4601 	.ioctl =	packet_ioctl,
4602 	.gettstamp =	sock_gettstamp,
4603 	.listen =	sock_no_listen,
4604 	.shutdown =	sock_no_shutdown,
4605 	.sendmsg =	packet_sendmsg_spkt,
4606 	.recvmsg =	packet_recvmsg,
4607 	.mmap =		sock_no_mmap,
4608 	.sendpage =	sock_no_sendpage,
4609 };
4610 
4611 static const struct proto_ops packet_ops = {
4612 	.family =	PF_PACKET,
4613 	.owner =	THIS_MODULE,
4614 	.release =	packet_release,
4615 	.bind =		packet_bind,
4616 	.connect =	sock_no_connect,
4617 	.socketpair =	sock_no_socketpair,
4618 	.accept =	sock_no_accept,
4619 	.getname =	packet_getname,
4620 	.poll =		packet_poll,
4621 	.ioctl =	packet_ioctl,
4622 	.gettstamp =	sock_gettstamp,
4623 	.listen =	sock_no_listen,
4624 	.shutdown =	sock_no_shutdown,
4625 	.setsockopt =	packet_setsockopt,
4626 	.getsockopt =	packet_getsockopt,
4627 	.sendmsg =	packet_sendmsg,
4628 	.recvmsg =	packet_recvmsg,
4629 	.mmap =		packet_mmap,
4630 	.sendpage =	sock_no_sendpage,
4631 };
4632 
4633 static const struct net_proto_family packet_family_ops = {
4634 	.family =	PF_PACKET,
4635 	.create =	packet_create,
4636 	.owner	=	THIS_MODULE,
4637 };
4638 
4639 static struct notifier_block packet_netdev_notifier = {
4640 	.notifier_call =	packet_notifier,
4641 };
4642 
4643 #ifdef CONFIG_PROC_FS
4644 
4645 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4646 	__acquires(RCU)
4647 {
4648 	struct net *net = seq_file_net(seq);
4649 
4650 	rcu_read_lock();
4651 	return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4652 }
4653 
4654 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4655 {
4656 	struct net *net = seq_file_net(seq);
4657 	return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4658 }
4659 
4660 static void packet_seq_stop(struct seq_file *seq, void *v)
4661 	__releases(RCU)
4662 {
4663 	rcu_read_unlock();
4664 }
4665 
4666 static int packet_seq_show(struct seq_file *seq, void *v)
4667 {
4668 	if (v == SEQ_START_TOKEN)
4669 		seq_printf(seq,
4670 			   "%*sRefCnt Type Proto  Iface R Rmem   User   Inode\n",
4671 			   IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk");
4672 	else {
4673 		struct sock *s = sk_entry(v);
4674 		const struct packet_sock *po = pkt_sk(s);
4675 
4676 		seq_printf(seq,
4677 			   "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4678 			   s,
4679 			   refcount_read(&s->sk_refcnt),
4680 			   s->sk_type,
4681 			   ntohs(READ_ONCE(po->num)),
4682 			   READ_ONCE(po->ifindex),
4683 			   po->running,
4684 			   atomic_read(&s->sk_rmem_alloc),
4685 			   from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4686 			   sock_i_ino(s));
4687 	}
4688 
4689 	return 0;
4690 }
4691 
4692 static const struct seq_operations packet_seq_ops = {
4693 	.start	= packet_seq_start,
4694 	.next	= packet_seq_next,
4695 	.stop	= packet_seq_stop,
4696 	.show	= packet_seq_show,
4697 };
4698 #endif
4699 
4700 static int __net_init packet_net_init(struct net *net)
4701 {
4702 	mutex_init(&net->packet.sklist_lock);
4703 	INIT_HLIST_HEAD(&net->packet.sklist);
4704 
4705 #ifdef CONFIG_PROC_FS
4706 	if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4707 			sizeof(struct seq_net_private)))
4708 		return -ENOMEM;
4709 #endif /* CONFIG_PROC_FS */
4710 
4711 	return 0;
4712 }
4713 
4714 static void __net_exit packet_net_exit(struct net *net)
4715 {
4716 	remove_proc_entry("packet", net->proc_net);
4717 	WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4718 }
4719 
4720 static struct pernet_operations packet_net_ops = {
4721 	.init = packet_net_init,
4722 	.exit = packet_net_exit,
4723 };
4724 
4725 
4726 static void __exit packet_exit(void)
4727 {
4728 	sock_unregister(PF_PACKET);
4729 	proto_unregister(&packet_proto);
4730 	unregister_netdevice_notifier(&packet_netdev_notifier);
4731 	unregister_pernet_subsys(&packet_net_ops);
4732 }
4733 
4734 static int __init packet_init(void)
4735 {
4736 	int rc;
4737 
4738 	rc = register_pernet_subsys(&packet_net_ops);
4739 	if (rc)
4740 		goto out;
4741 	rc = register_netdevice_notifier(&packet_netdev_notifier);
4742 	if (rc)
4743 		goto out_pernet;
4744 	rc = proto_register(&packet_proto, 0);
4745 	if (rc)
4746 		goto out_notifier;
4747 	rc = sock_register(&packet_family_ops);
4748 	if (rc)
4749 		goto out_proto;
4750 
4751 	return 0;
4752 
4753 out_proto:
4754 	proto_unregister(&packet_proto);
4755 out_notifier:
4756 	unregister_netdevice_notifier(&packet_netdev_notifier);
4757 out_pernet:
4758 	unregister_pernet_subsys(&packet_net_ops);
4759 out:
4760 	return rc;
4761 }
4762 
4763 module_init(packet_init);
4764 module_exit(packet_exit);
4765 MODULE_LICENSE("GPL");
4766 MODULE_ALIAS_NETPROTO(PF_PACKET);
4767