xref: /linux/net/packet/af_packet.c (revision 2b0cfa6e49566c8fa6759734cf821aa6e8271a9e)
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_xmit(const struct packet_sock *po, struct sk_buff *skb)
274 {
275 	if (!packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS))
276 		return dev_queue_xmit(skb);
277 
278 #ifdef CONFIG_NETFILTER_EGRESS
279 	if (nf_hook_egress_active()) {
280 		skb = nf_hook_direct_egress(skb);
281 		if (!skb)
282 			return NET_XMIT_DROP;
283 	}
284 #endif
285 	return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
286 }
287 
288 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
289 {
290 	struct net_device *dev;
291 
292 	rcu_read_lock();
293 	dev = rcu_dereference(po->cached_dev);
294 	dev_hold(dev);
295 	rcu_read_unlock();
296 
297 	return dev;
298 }
299 
300 static void packet_cached_dev_assign(struct packet_sock *po,
301 				     struct net_device *dev)
302 {
303 	rcu_assign_pointer(po->cached_dev, dev);
304 }
305 
306 static void packet_cached_dev_reset(struct packet_sock *po)
307 {
308 	RCU_INIT_POINTER(po->cached_dev, NULL);
309 }
310 
311 static u16 packet_pick_tx_queue(struct sk_buff *skb)
312 {
313 	struct net_device *dev = skb->dev;
314 	const struct net_device_ops *ops = dev->netdev_ops;
315 	int cpu = raw_smp_processor_id();
316 	u16 queue_index;
317 
318 #ifdef CONFIG_XPS
319 	skb->sender_cpu = cpu + 1;
320 #endif
321 	skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
322 	if (ops->ndo_select_queue) {
323 		queue_index = ops->ndo_select_queue(dev, skb, NULL);
324 		queue_index = netdev_cap_txqueue(dev, queue_index);
325 	} else {
326 		queue_index = netdev_pick_tx(dev, skb, NULL);
327 	}
328 
329 	return queue_index;
330 }
331 
332 /* __register_prot_hook must be invoked through register_prot_hook
333  * or from a context in which asynchronous accesses to the packet
334  * socket is not possible (packet_create()).
335  */
336 static void __register_prot_hook(struct sock *sk)
337 {
338 	struct packet_sock *po = pkt_sk(sk);
339 
340 	if (!packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
341 		if (po->fanout)
342 			__fanout_link(sk, po);
343 		else
344 			dev_add_pack(&po->prot_hook);
345 
346 		sock_hold(sk);
347 		packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 1);
348 	}
349 }
350 
351 static void register_prot_hook(struct sock *sk)
352 {
353 	lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
354 	__register_prot_hook(sk);
355 }
356 
357 /* If the sync parameter is true, we will temporarily drop
358  * the po->bind_lock and do a synchronize_net to make sure no
359  * asynchronous packet processing paths still refer to the elements
360  * of po->prot_hook.  If the sync parameter is false, it is the
361  * callers responsibility to take care of this.
362  */
363 static void __unregister_prot_hook(struct sock *sk, bool sync)
364 {
365 	struct packet_sock *po = pkt_sk(sk);
366 
367 	lockdep_assert_held_once(&po->bind_lock);
368 
369 	packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 0);
370 
371 	if (po->fanout)
372 		__fanout_unlink(sk, po);
373 	else
374 		__dev_remove_pack(&po->prot_hook);
375 
376 	__sock_put(sk);
377 
378 	if (sync) {
379 		spin_unlock(&po->bind_lock);
380 		synchronize_net();
381 		spin_lock(&po->bind_lock);
382 	}
383 }
384 
385 static void unregister_prot_hook(struct sock *sk, bool sync)
386 {
387 	struct packet_sock *po = pkt_sk(sk);
388 
389 	if (packet_sock_flag(po, PACKET_SOCK_RUNNING))
390 		__unregister_prot_hook(sk, sync);
391 }
392 
393 static inline struct page * __pure pgv_to_page(void *addr)
394 {
395 	if (is_vmalloc_addr(addr))
396 		return vmalloc_to_page(addr);
397 	return virt_to_page(addr);
398 }
399 
400 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
401 {
402 	union tpacket_uhdr h;
403 
404 	/* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */
405 
406 	h.raw = frame;
407 	switch (po->tp_version) {
408 	case TPACKET_V1:
409 		WRITE_ONCE(h.h1->tp_status, status);
410 		flush_dcache_page(pgv_to_page(&h.h1->tp_status));
411 		break;
412 	case TPACKET_V2:
413 		WRITE_ONCE(h.h2->tp_status, status);
414 		flush_dcache_page(pgv_to_page(&h.h2->tp_status));
415 		break;
416 	case TPACKET_V3:
417 		WRITE_ONCE(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 	/* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */
435 
436 	h.raw = frame;
437 	switch (po->tp_version) {
438 	case TPACKET_V1:
439 		flush_dcache_page(pgv_to_page(&h.h1->tp_status));
440 		return READ_ONCE(h.h1->tp_status);
441 	case TPACKET_V2:
442 		flush_dcache_page(pgv_to_page(&h.h2->tp_status));
443 		return READ_ONCE(h.h2->tp_status);
444 	case TPACKET_V3:
445 		flush_dcache_page(pgv_to_page(&h.h3->tp_status));
446 		return READ_ONCE(h.h3->tp_status);
447 	default:
448 		WARN(1, "TPACKET version not supported.\n");
449 		BUG();
450 		return 0;
451 	}
452 }
453 
454 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts,
455 				   unsigned int flags)
456 {
457 	struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
458 
459 	if (shhwtstamps &&
460 	    (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
461 	    ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts))
462 		return TP_STATUS_TS_RAW_HARDWARE;
463 
464 	if ((flags & SOF_TIMESTAMPING_SOFTWARE) &&
465 	    ktime_to_timespec64_cond(skb_tstamp(skb), ts))
466 		return TP_STATUS_TS_SOFTWARE;
467 
468 	return 0;
469 }
470 
471 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
472 				    struct sk_buff *skb)
473 {
474 	union tpacket_uhdr h;
475 	struct timespec64 ts;
476 	__u32 ts_status;
477 
478 	if (!(ts_status = tpacket_get_timestamp(skb, &ts, READ_ONCE(po->tp_tstamp))))
479 		return 0;
480 
481 	h.raw = frame;
482 	/*
483 	 * versions 1 through 3 overflow the timestamps in y2106, since they
484 	 * all store the seconds in a 32-bit unsigned integer.
485 	 * If we create a version 4, that should have a 64-bit timestamp,
486 	 * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit
487 	 * nanoseconds.
488 	 */
489 	switch (po->tp_version) {
490 	case TPACKET_V1:
491 		h.h1->tp_sec = ts.tv_sec;
492 		h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
493 		break;
494 	case TPACKET_V2:
495 		h.h2->tp_sec = ts.tv_sec;
496 		h.h2->tp_nsec = ts.tv_nsec;
497 		break;
498 	case TPACKET_V3:
499 		h.h3->tp_sec = ts.tv_sec;
500 		h.h3->tp_nsec = ts.tv_nsec;
501 		break;
502 	default:
503 		WARN(1, "TPACKET version not supported.\n");
504 		BUG();
505 	}
506 
507 	/* one flush is safe, as both fields always lie on the same cacheline */
508 	flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
509 	smp_wmb();
510 
511 	return ts_status;
512 }
513 
514 static void *packet_lookup_frame(const struct packet_sock *po,
515 				 const struct packet_ring_buffer *rb,
516 				 unsigned int position,
517 				 int status)
518 {
519 	unsigned int pg_vec_pos, frame_offset;
520 	union tpacket_uhdr h;
521 
522 	pg_vec_pos = position / rb->frames_per_block;
523 	frame_offset = position % rb->frames_per_block;
524 
525 	h.raw = rb->pg_vec[pg_vec_pos].buffer +
526 		(frame_offset * rb->frame_size);
527 
528 	if (status != __packet_get_status(po, h.raw))
529 		return NULL;
530 
531 	return h.raw;
532 }
533 
534 static void *packet_current_frame(struct packet_sock *po,
535 		struct packet_ring_buffer *rb,
536 		int status)
537 {
538 	return packet_lookup_frame(po, rb, rb->head, status);
539 }
540 
541 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
542 {
543 	del_timer_sync(&pkc->retire_blk_timer);
544 }
545 
546 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
547 		struct sk_buff_head *rb_queue)
548 {
549 	struct tpacket_kbdq_core *pkc;
550 
551 	pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
552 
553 	spin_lock_bh(&rb_queue->lock);
554 	pkc->delete_blk_timer = 1;
555 	spin_unlock_bh(&rb_queue->lock);
556 
557 	prb_del_retire_blk_timer(pkc);
558 }
559 
560 static void prb_setup_retire_blk_timer(struct packet_sock *po)
561 {
562 	struct tpacket_kbdq_core *pkc;
563 
564 	pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
565 	timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
566 		    0);
567 	pkc->retire_blk_timer.expires = jiffies;
568 }
569 
570 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
571 				int blk_size_in_bytes)
572 {
573 	struct net_device *dev;
574 	unsigned int mbits, div;
575 	struct ethtool_link_ksettings ecmd;
576 	int err;
577 
578 	rtnl_lock();
579 	dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
580 	if (unlikely(!dev)) {
581 		rtnl_unlock();
582 		return DEFAULT_PRB_RETIRE_TOV;
583 	}
584 	err = __ethtool_get_link_ksettings(dev, &ecmd);
585 	rtnl_unlock();
586 	if (err)
587 		return DEFAULT_PRB_RETIRE_TOV;
588 
589 	/* If the link speed is so slow you don't really
590 	 * need to worry about perf anyways
591 	 */
592 	if (ecmd.base.speed < SPEED_1000 ||
593 	    ecmd.base.speed == SPEED_UNKNOWN)
594 		return DEFAULT_PRB_RETIRE_TOV;
595 
596 	div = ecmd.base.speed / 1000;
597 	mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
598 
599 	if (div)
600 		mbits /= div;
601 
602 	if (div)
603 		return mbits + 1;
604 	return mbits;
605 }
606 
607 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
608 			union tpacket_req_u *req_u)
609 {
610 	p1->feature_req_word = req_u->req3.tp_feature_req_word;
611 }
612 
613 static void init_prb_bdqc(struct packet_sock *po,
614 			struct packet_ring_buffer *rb,
615 			struct pgv *pg_vec,
616 			union tpacket_req_u *req_u)
617 {
618 	struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
619 	struct tpacket_block_desc *pbd;
620 
621 	memset(p1, 0x0, sizeof(*p1));
622 
623 	p1->knxt_seq_num = 1;
624 	p1->pkbdq = pg_vec;
625 	pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
626 	p1->pkblk_start	= pg_vec[0].buffer;
627 	p1->kblk_size = req_u->req3.tp_block_size;
628 	p1->knum_blocks	= req_u->req3.tp_block_nr;
629 	p1->hdrlen = po->tp_hdrlen;
630 	p1->version = po->tp_version;
631 	p1->last_kactive_blk_num = 0;
632 	po->stats.stats3.tp_freeze_q_cnt = 0;
633 	if (req_u->req3.tp_retire_blk_tov)
634 		p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
635 	else
636 		p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
637 						req_u->req3.tp_block_size);
638 	p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
639 	p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
640 	rwlock_init(&p1->blk_fill_in_prog_lock);
641 
642 	p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
643 	prb_init_ft_ops(p1, req_u);
644 	prb_setup_retire_blk_timer(po);
645 	prb_open_block(p1, pbd);
646 }
647 
648 /*  Do NOT update the last_blk_num first.
649  *  Assumes sk_buff_head lock is held.
650  */
651 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
652 {
653 	mod_timer(&pkc->retire_blk_timer,
654 			jiffies + pkc->tov_in_jiffies);
655 	pkc->last_kactive_blk_num = pkc->kactive_blk_num;
656 }
657 
658 /*
659  * Timer logic:
660  * 1) We refresh the timer only when we open a block.
661  *    By doing this we don't waste cycles refreshing the timer
662  *	  on packet-by-packet basis.
663  *
664  * With a 1MB block-size, on a 1Gbps line, it will take
665  * i) ~8 ms to fill a block + ii) memcpy etc.
666  * In this cut we are not accounting for the memcpy time.
667  *
668  * So, if the user sets the 'tmo' to 10ms then the timer
669  * will never fire while the block is still getting filled
670  * (which is what we want). However, the user could choose
671  * to close a block early and that's fine.
672  *
673  * But when the timer does fire, we check whether or not to refresh it.
674  * Since the tmo granularity is in msecs, it is not too expensive
675  * to refresh the timer, lets say every '8' msecs.
676  * Either the user can set the 'tmo' or we can derive it based on
677  * a) line-speed and b) block-size.
678  * prb_calc_retire_blk_tmo() calculates the tmo.
679  *
680  */
681 static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
682 {
683 	struct packet_sock *po =
684 		from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
685 	struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
686 	unsigned int frozen;
687 	struct tpacket_block_desc *pbd;
688 
689 	spin_lock(&po->sk.sk_receive_queue.lock);
690 
691 	frozen = prb_queue_frozen(pkc);
692 	pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
693 
694 	if (unlikely(pkc->delete_blk_timer))
695 		goto out;
696 
697 	/* We only need to plug the race when the block is partially filled.
698 	 * tpacket_rcv:
699 	 *		lock(); increment BLOCK_NUM_PKTS; unlock()
700 	 *		copy_bits() is in progress ...
701 	 *		timer fires on other cpu:
702 	 *		we can't retire the current block because copy_bits
703 	 *		is in progress.
704 	 *
705 	 */
706 	if (BLOCK_NUM_PKTS(pbd)) {
707 		/* Waiting for skb_copy_bits to finish... */
708 		write_lock(&pkc->blk_fill_in_prog_lock);
709 		write_unlock(&pkc->blk_fill_in_prog_lock);
710 	}
711 
712 	if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
713 		if (!frozen) {
714 			if (!BLOCK_NUM_PKTS(pbd)) {
715 				/* An empty block. Just refresh the timer. */
716 				goto refresh_timer;
717 			}
718 			prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
719 			if (!prb_dispatch_next_block(pkc, po))
720 				goto refresh_timer;
721 			else
722 				goto out;
723 		} else {
724 			/* Case 1. Queue was frozen because user-space was
725 			 *	   lagging behind.
726 			 */
727 			if (prb_curr_blk_in_use(pbd)) {
728 				/*
729 				 * Ok, user-space is still behind.
730 				 * So just refresh the timer.
731 				 */
732 				goto refresh_timer;
733 			} else {
734 			       /* Case 2. queue was frozen,user-space caught up,
735 				* now the link went idle && the timer fired.
736 				* We don't have a block to close.So we open this
737 				* block and restart the timer.
738 				* opening a block thaws the queue,restarts timer
739 				* Thawing/timer-refresh is a side effect.
740 				*/
741 				prb_open_block(pkc, pbd);
742 				goto out;
743 			}
744 		}
745 	}
746 
747 refresh_timer:
748 	_prb_refresh_rx_retire_blk_timer(pkc);
749 
750 out:
751 	spin_unlock(&po->sk.sk_receive_queue.lock);
752 }
753 
754 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
755 		struct tpacket_block_desc *pbd1, __u32 status)
756 {
757 	/* Flush everything minus the block header */
758 
759 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
760 	u8 *start, *end;
761 
762 	start = (u8 *)pbd1;
763 
764 	/* Skip the block header(we know header WILL fit in 4K) */
765 	start += PAGE_SIZE;
766 
767 	end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
768 	for (; start < end; start += PAGE_SIZE)
769 		flush_dcache_page(pgv_to_page(start));
770 
771 	smp_wmb();
772 #endif
773 
774 	/* Now update the block status. */
775 
776 	BLOCK_STATUS(pbd1) = status;
777 
778 	/* Flush the block header */
779 
780 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
781 	start = (u8 *)pbd1;
782 	flush_dcache_page(pgv_to_page(start));
783 
784 	smp_wmb();
785 #endif
786 }
787 
788 /*
789  * Side effect:
790  *
791  * 1) flush the block
792  * 2) Increment active_blk_num
793  *
794  * Note:We DONT refresh the timer on purpose.
795  *	Because almost always the next block will be opened.
796  */
797 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
798 		struct tpacket_block_desc *pbd1,
799 		struct packet_sock *po, unsigned int stat)
800 {
801 	__u32 status = TP_STATUS_USER | stat;
802 
803 	struct tpacket3_hdr *last_pkt;
804 	struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
805 	struct sock *sk = &po->sk;
806 
807 	if (atomic_read(&po->tp_drops))
808 		status |= TP_STATUS_LOSING;
809 
810 	last_pkt = (struct tpacket3_hdr *)pkc1->prev;
811 	last_pkt->tp_next_offset = 0;
812 
813 	/* Get the ts of the last pkt */
814 	if (BLOCK_NUM_PKTS(pbd1)) {
815 		h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
816 		h1->ts_last_pkt.ts_nsec	= last_pkt->tp_nsec;
817 	} else {
818 		/* Ok, we tmo'd - so get the current time.
819 		 *
820 		 * It shouldn't really happen as we don't close empty
821 		 * blocks. See prb_retire_rx_blk_timer_expired().
822 		 */
823 		struct timespec64 ts;
824 		ktime_get_real_ts64(&ts);
825 		h1->ts_last_pkt.ts_sec = ts.tv_sec;
826 		h1->ts_last_pkt.ts_nsec	= ts.tv_nsec;
827 	}
828 
829 	smp_wmb();
830 
831 	/* Flush the block */
832 	prb_flush_block(pkc1, pbd1, status);
833 
834 	sk->sk_data_ready(sk);
835 
836 	pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
837 }
838 
839 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
840 {
841 	pkc->reset_pending_on_curr_blk = 0;
842 }
843 
844 /*
845  * Side effect of opening a block:
846  *
847  * 1) prb_queue is thawed.
848  * 2) retire_blk_timer is refreshed.
849  *
850  */
851 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
852 	struct tpacket_block_desc *pbd1)
853 {
854 	struct timespec64 ts;
855 	struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
856 
857 	smp_rmb();
858 
859 	/* We could have just memset this but we will lose the
860 	 * flexibility of making the priv area sticky
861 	 */
862 
863 	BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
864 	BLOCK_NUM_PKTS(pbd1) = 0;
865 	BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
866 
867 	ktime_get_real_ts64(&ts);
868 
869 	h1->ts_first_pkt.ts_sec = ts.tv_sec;
870 	h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
871 
872 	pkc1->pkblk_start = (char *)pbd1;
873 	pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
874 
875 	BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
876 	BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
877 
878 	pbd1->version = pkc1->version;
879 	pkc1->prev = pkc1->nxt_offset;
880 	pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
881 
882 	prb_thaw_queue(pkc1);
883 	_prb_refresh_rx_retire_blk_timer(pkc1);
884 
885 	smp_wmb();
886 }
887 
888 /*
889  * Queue freeze logic:
890  * 1) Assume tp_block_nr = 8 blocks.
891  * 2) At time 't0', user opens Rx ring.
892  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
893  * 4) user-space is either sleeping or processing block '0'.
894  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
895  *    it will close block-7,loop around and try to fill block '0'.
896  *    call-flow:
897  *    __packet_lookup_frame_in_block
898  *      prb_retire_current_block()
899  *      prb_dispatch_next_block()
900  *        |->(BLOCK_STATUS == USER) evaluates to true
901  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
902  * 6) Now there are two cases:
903  *    6.1) Link goes idle right after the queue is frozen.
904  *         But remember, the last open_block() refreshed the timer.
905  *         When this timer expires,it will refresh itself so that we can
906  *         re-open block-0 in near future.
907  *    6.2) Link is busy and keeps on receiving packets. This is a simple
908  *         case and __packet_lookup_frame_in_block will check if block-0
909  *         is free and can now be re-used.
910  */
911 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
912 				  struct packet_sock *po)
913 {
914 	pkc->reset_pending_on_curr_blk = 1;
915 	po->stats.stats3.tp_freeze_q_cnt++;
916 }
917 
918 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
919 
920 /*
921  * If the next block is free then we will dispatch it
922  * and return a good offset.
923  * Else, we will freeze the queue.
924  * So, caller must check the return value.
925  */
926 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
927 		struct packet_sock *po)
928 {
929 	struct tpacket_block_desc *pbd;
930 
931 	smp_rmb();
932 
933 	/* 1. Get current block num */
934 	pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
935 
936 	/* 2. If this block is currently in_use then freeze the queue */
937 	if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
938 		prb_freeze_queue(pkc, po);
939 		return NULL;
940 	}
941 
942 	/*
943 	 * 3.
944 	 * open this block and return the offset where the first packet
945 	 * needs to get stored.
946 	 */
947 	prb_open_block(pkc, pbd);
948 	return (void *)pkc->nxt_offset;
949 }
950 
951 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
952 		struct packet_sock *po, unsigned int status)
953 {
954 	struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
955 
956 	/* retire/close the current block */
957 	if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
958 		/*
959 		 * Plug the case where copy_bits() is in progress on
960 		 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
961 		 * have space to copy the pkt in the current block and
962 		 * called prb_retire_current_block()
963 		 *
964 		 * We don't need to worry about the TMO case because
965 		 * the timer-handler already handled this case.
966 		 */
967 		if (!(status & TP_STATUS_BLK_TMO)) {
968 			/* Waiting for skb_copy_bits to finish... */
969 			write_lock(&pkc->blk_fill_in_prog_lock);
970 			write_unlock(&pkc->blk_fill_in_prog_lock);
971 		}
972 		prb_close_block(pkc, pbd, po, status);
973 		return;
974 	}
975 }
976 
977 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
978 {
979 	return TP_STATUS_USER & BLOCK_STATUS(pbd);
980 }
981 
982 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
983 {
984 	return pkc->reset_pending_on_curr_blk;
985 }
986 
987 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
988 	__releases(&pkc->blk_fill_in_prog_lock)
989 {
990 	struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
991 
992 	read_unlock(&pkc->blk_fill_in_prog_lock);
993 }
994 
995 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
996 			struct tpacket3_hdr *ppd)
997 {
998 	ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
999 }
1000 
1001 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
1002 			struct tpacket3_hdr *ppd)
1003 {
1004 	ppd->hv1.tp_rxhash = 0;
1005 }
1006 
1007 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
1008 			struct tpacket3_hdr *ppd)
1009 {
1010 	if (skb_vlan_tag_present(pkc->skb)) {
1011 		ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1012 		ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1013 		ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1014 	} else {
1015 		ppd->hv1.tp_vlan_tci = 0;
1016 		ppd->hv1.tp_vlan_tpid = 0;
1017 		ppd->tp_status = TP_STATUS_AVAILABLE;
1018 	}
1019 }
1020 
1021 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1022 			struct tpacket3_hdr *ppd)
1023 {
1024 	ppd->hv1.tp_padding = 0;
1025 	prb_fill_vlan_info(pkc, ppd);
1026 
1027 	if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1028 		prb_fill_rxhash(pkc, ppd);
1029 	else
1030 		prb_clear_rxhash(pkc, ppd);
1031 }
1032 
1033 static void prb_fill_curr_block(char *curr,
1034 				struct tpacket_kbdq_core *pkc,
1035 				struct tpacket_block_desc *pbd,
1036 				unsigned int len)
1037 	__acquires(&pkc->blk_fill_in_prog_lock)
1038 {
1039 	struct tpacket3_hdr *ppd;
1040 
1041 	ppd  = (struct tpacket3_hdr *)curr;
1042 	ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1043 	pkc->prev = curr;
1044 	pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1045 	BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1046 	BLOCK_NUM_PKTS(pbd) += 1;
1047 	read_lock(&pkc->blk_fill_in_prog_lock);
1048 	prb_run_all_ft_ops(pkc, ppd);
1049 }
1050 
1051 /* Assumes caller has the sk->rx_queue.lock */
1052 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1053 					    struct sk_buff *skb,
1054 					    unsigned int len
1055 					    )
1056 {
1057 	struct tpacket_kbdq_core *pkc;
1058 	struct tpacket_block_desc *pbd;
1059 	char *curr, *end;
1060 
1061 	pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1062 	pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1063 
1064 	/* Queue is frozen when user space is lagging behind */
1065 	if (prb_queue_frozen(pkc)) {
1066 		/*
1067 		 * Check if that last block which caused the queue to freeze,
1068 		 * is still in_use by user-space.
1069 		 */
1070 		if (prb_curr_blk_in_use(pbd)) {
1071 			/* Can't record this packet */
1072 			return NULL;
1073 		} else {
1074 			/*
1075 			 * Ok, the block was released by user-space.
1076 			 * Now let's open that block.
1077 			 * opening a block also thaws the queue.
1078 			 * Thawing is a side effect.
1079 			 */
1080 			prb_open_block(pkc, pbd);
1081 		}
1082 	}
1083 
1084 	smp_mb();
1085 	curr = pkc->nxt_offset;
1086 	pkc->skb = skb;
1087 	end = (char *)pbd + pkc->kblk_size;
1088 
1089 	/* first try the current block */
1090 	if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1091 		prb_fill_curr_block(curr, pkc, pbd, len);
1092 		return (void *)curr;
1093 	}
1094 
1095 	/* Ok, close the current block */
1096 	prb_retire_current_block(pkc, po, 0);
1097 
1098 	/* Now, try to dispatch the next block */
1099 	curr = (char *)prb_dispatch_next_block(pkc, po);
1100 	if (curr) {
1101 		pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1102 		prb_fill_curr_block(curr, pkc, pbd, len);
1103 		return (void *)curr;
1104 	}
1105 
1106 	/*
1107 	 * No free blocks are available.user_space hasn't caught up yet.
1108 	 * Queue was just frozen and now this packet will get dropped.
1109 	 */
1110 	return NULL;
1111 }
1112 
1113 static void *packet_current_rx_frame(struct packet_sock *po,
1114 					    struct sk_buff *skb,
1115 					    int status, unsigned int len)
1116 {
1117 	char *curr = NULL;
1118 	switch (po->tp_version) {
1119 	case TPACKET_V1:
1120 	case TPACKET_V2:
1121 		curr = packet_lookup_frame(po, &po->rx_ring,
1122 					po->rx_ring.head, status);
1123 		return curr;
1124 	case TPACKET_V3:
1125 		return __packet_lookup_frame_in_block(po, skb, len);
1126 	default:
1127 		WARN(1, "TPACKET version not supported\n");
1128 		BUG();
1129 		return NULL;
1130 	}
1131 }
1132 
1133 static void *prb_lookup_block(const struct packet_sock *po,
1134 			      const struct packet_ring_buffer *rb,
1135 			      unsigned int idx,
1136 			      int status)
1137 {
1138 	struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1139 	struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1140 
1141 	if (status != BLOCK_STATUS(pbd))
1142 		return NULL;
1143 	return pbd;
1144 }
1145 
1146 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1147 {
1148 	unsigned int prev;
1149 	if (rb->prb_bdqc.kactive_blk_num)
1150 		prev = rb->prb_bdqc.kactive_blk_num-1;
1151 	else
1152 		prev = rb->prb_bdqc.knum_blocks-1;
1153 	return prev;
1154 }
1155 
1156 /* Assumes caller has held the rx_queue.lock */
1157 static void *__prb_previous_block(struct packet_sock *po,
1158 					 struct packet_ring_buffer *rb,
1159 					 int status)
1160 {
1161 	unsigned int previous = prb_previous_blk_num(rb);
1162 	return prb_lookup_block(po, rb, previous, status);
1163 }
1164 
1165 static void *packet_previous_rx_frame(struct packet_sock *po,
1166 					     struct packet_ring_buffer *rb,
1167 					     int status)
1168 {
1169 	if (po->tp_version <= TPACKET_V2)
1170 		return packet_previous_frame(po, rb, status);
1171 
1172 	return __prb_previous_block(po, rb, status);
1173 }
1174 
1175 static void packet_increment_rx_head(struct packet_sock *po,
1176 					    struct packet_ring_buffer *rb)
1177 {
1178 	switch (po->tp_version) {
1179 	case TPACKET_V1:
1180 	case TPACKET_V2:
1181 		return packet_increment_head(rb);
1182 	case TPACKET_V3:
1183 	default:
1184 		WARN(1, "TPACKET version not supported.\n");
1185 		BUG();
1186 		return;
1187 	}
1188 }
1189 
1190 static void *packet_previous_frame(struct packet_sock *po,
1191 		struct packet_ring_buffer *rb,
1192 		int status)
1193 {
1194 	unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1195 	return packet_lookup_frame(po, rb, previous, status);
1196 }
1197 
1198 static void packet_increment_head(struct packet_ring_buffer *buff)
1199 {
1200 	buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1201 }
1202 
1203 static void packet_inc_pending(struct packet_ring_buffer *rb)
1204 {
1205 	this_cpu_inc(*rb->pending_refcnt);
1206 }
1207 
1208 static void packet_dec_pending(struct packet_ring_buffer *rb)
1209 {
1210 	this_cpu_dec(*rb->pending_refcnt);
1211 }
1212 
1213 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1214 {
1215 	unsigned int refcnt = 0;
1216 	int cpu;
1217 
1218 	/* We don't use pending refcount in rx_ring. */
1219 	if (rb->pending_refcnt == NULL)
1220 		return 0;
1221 
1222 	for_each_possible_cpu(cpu)
1223 		refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1224 
1225 	return refcnt;
1226 }
1227 
1228 static int packet_alloc_pending(struct packet_sock *po)
1229 {
1230 	po->rx_ring.pending_refcnt = NULL;
1231 
1232 	po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1233 	if (unlikely(po->tx_ring.pending_refcnt == NULL))
1234 		return -ENOBUFS;
1235 
1236 	return 0;
1237 }
1238 
1239 static void packet_free_pending(struct packet_sock *po)
1240 {
1241 	free_percpu(po->tx_ring.pending_refcnt);
1242 }
1243 
1244 #define ROOM_POW_OFF	2
1245 #define ROOM_NONE	0x0
1246 #define ROOM_LOW	0x1
1247 #define ROOM_NORMAL	0x2
1248 
1249 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1250 {
1251 	int idx, len;
1252 
1253 	len = READ_ONCE(po->rx_ring.frame_max) + 1;
1254 	idx = READ_ONCE(po->rx_ring.head);
1255 	if (pow_off)
1256 		idx += len >> pow_off;
1257 	if (idx >= len)
1258 		idx -= len;
1259 	return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1260 }
1261 
1262 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1263 {
1264 	int idx, len;
1265 
1266 	len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1267 	idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1268 	if (pow_off)
1269 		idx += len >> pow_off;
1270 	if (idx >= len)
1271 		idx -= len;
1272 	return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1273 }
1274 
1275 static int __packet_rcv_has_room(const struct packet_sock *po,
1276 				 const struct sk_buff *skb)
1277 {
1278 	const struct sock *sk = &po->sk;
1279 	int ret = ROOM_NONE;
1280 
1281 	if (po->prot_hook.func != tpacket_rcv) {
1282 		int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1283 		int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1284 				   - (skb ? skb->truesize : 0);
1285 
1286 		if (avail > (rcvbuf >> ROOM_POW_OFF))
1287 			return ROOM_NORMAL;
1288 		else if (avail > 0)
1289 			return ROOM_LOW;
1290 		else
1291 			return ROOM_NONE;
1292 	}
1293 
1294 	if (po->tp_version == TPACKET_V3) {
1295 		if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1296 			ret = ROOM_NORMAL;
1297 		else if (__tpacket_v3_has_room(po, 0))
1298 			ret = ROOM_LOW;
1299 	} else {
1300 		if (__tpacket_has_room(po, ROOM_POW_OFF))
1301 			ret = ROOM_NORMAL;
1302 		else if (__tpacket_has_room(po, 0))
1303 			ret = ROOM_LOW;
1304 	}
1305 
1306 	return ret;
1307 }
1308 
1309 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1310 {
1311 	bool pressure;
1312 	int ret;
1313 
1314 	ret = __packet_rcv_has_room(po, skb);
1315 	pressure = ret != ROOM_NORMAL;
1316 
1317 	if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure)
1318 		packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure);
1319 
1320 	return ret;
1321 }
1322 
1323 static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1324 {
1325 	if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) &&
1326 	    __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1327 		packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false);
1328 }
1329 
1330 static void packet_sock_destruct(struct sock *sk)
1331 {
1332 	skb_queue_purge(&sk->sk_error_queue);
1333 
1334 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1335 	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1336 
1337 	if (!sock_flag(sk, SOCK_DEAD)) {
1338 		pr_err("Attempt to release alive packet socket: %p\n", sk);
1339 		return;
1340 	}
1341 }
1342 
1343 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1344 {
1345 	u32 *history = po->rollover->history;
1346 	u32 victim, rxhash;
1347 	int i, count = 0;
1348 
1349 	rxhash = skb_get_hash(skb);
1350 	for (i = 0; i < ROLLOVER_HLEN; i++)
1351 		if (READ_ONCE(history[i]) == rxhash)
1352 			count++;
1353 
1354 	victim = get_random_u32_below(ROLLOVER_HLEN);
1355 
1356 	/* Avoid dirtying the cache line if possible */
1357 	if (READ_ONCE(history[victim]) != rxhash)
1358 		WRITE_ONCE(history[victim], rxhash);
1359 
1360 	return count > (ROLLOVER_HLEN >> 1);
1361 }
1362 
1363 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1364 				      struct sk_buff *skb,
1365 				      unsigned int num)
1366 {
1367 	return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1368 }
1369 
1370 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1371 				    struct sk_buff *skb,
1372 				    unsigned int num)
1373 {
1374 	unsigned int val = atomic_inc_return(&f->rr_cur);
1375 
1376 	return val % num;
1377 }
1378 
1379 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1380 				     struct sk_buff *skb,
1381 				     unsigned int num)
1382 {
1383 	return smp_processor_id() % num;
1384 }
1385 
1386 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1387 				     struct sk_buff *skb,
1388 				     unsigned int num)
1389 {
1390 	return get_random_u32_below(num);
1391 }
1392 
1393 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1394 					  struct sk_buff *skb,
1395 					  unsigned int idx, bool try_self,
1396 					  unsigned int num)
1397 {
1398 	struct packet_sock *po, *po_next, *po_skip = NULL;
1399 	unsigned int i, j, room = ROOM_NONE;
1400 
1401 	po = pkt_sk(rcu_dereference(f->arr[idx]));
1402 
1403 	if (try_self) {
1404 		room = packet_rcv_has_room(po, skb);
1405 		if (room == ROOM_NORMAL ||
1406 		    (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1407 			return idx;
1408 		po_skip = po;
1409 	}
1410 
1411 	i = j = min_t(int, po->rollover->sock, num - 1);
1412 	do {
1413 		po_next = pkt_sk(rcu_dereference(f->arr[i]));
1414 		if (po_next != po_skip &&
1415 		    !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) &&
1416 		    packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1417 			if (i != j)
1418 				po->rollover->sock = i;
1419 			atomic_long_inc(&po->rollover->num);
1420 			if (room == ROOM_LOW)
1421 				atomic_long_inc(&po->rollover->num_huge);
1422 			return i;
1423 		}
1424 
1425 		if (++i == num)
1426 			i = 0;
1427 	} while (i != j);
1428 
1429 	atomic_long_inc(&po->rollover->num_failed);
1430 	return idx;
1431 }
1432 
1433 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1434 				    struct sk_buff *skb,
1435 				    unsigned int num)
1436 {
1437 	return skb_get_queue_mapping(skb) % num;
1438 }
1439 
1440 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1441 				     struct sk_buff *skb,
1442 				     unsigned int num)
1443 {
1444 	struct bpf_prog *prog;
1445 	unsigned int ret = 0;
1446 
1447 	rcu_read_lock();
1448 	prog = rcu_dereference(f->bpf_prog);
1449 	if (prog)
1450 		ret = bpf_prog_run_clear_cb(prog, skb) % num;
1451 	rcu_read_unlock();
1452 
1453 	return ret;
1454 }
1455 
1456 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1457 {
1458 	return f->flags & (flag >> 8);
1459 }
1460 
1461 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1462 			     struct packet_type *pt, struct net_device *orig_dev)
1463 {
1464 	struct packet_fanout *f = pt->af_packet_priv;
1465 	unsigned int num = READ_ONCE(f->num_members);
1466 	struct net *net = read_pnet(&f->net);
1467 	struct packet_sock *po;
1468 	unsigned int idx;
1469 
1470 	if (!net_eq(dev_net(dev), net) || !num) {
1471 		kfree_skb(skb);
1472 		return 0;
1473 	}
1474 
1475 	if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1476 		skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1477 		if (!skb)
1478 			return 0;
1479 	}
1480 	switch (f->type) {
1481 	case PACKET_FANOUT_HASH:
1482 	default:
1483 		idx = fanout_demux_hash(f, skb, num);
1484 		break;
1485 	case PACKET_FANOUT_LB:
1486 		idx = fanout_demux_lb(f, skb, num);
1487 		break;
1488 	case PACKET_FANOUT_CPU:
1489 		idx = fanout_demux_cpu(f, skb, num);
1490 		break;
1491 	case PACKET_FANOUT_RND:
1492 		idx = fanout_demux_rnd(f, skb, num);
1493 		break;
1494 	case PACKET_FANOUT_QM:
1495 		idx = fanout_demux_qm(f, skb, num);
1496 		break;
1497 	case PACKET_FANOUT_ROLLOVER:
1498 		idx = fanout_demux_rollover(f, skb, 0, false, num);
1499 		break;
1500 	case PACKET_FANOUT_CBPF:
1501 	case PACKET_FANOUT_EBPF:
1502 		idx = fanout_demux_bpf(f, skb, num);
1503 		break;
1504 	}
1505 
1506 	if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1507 		idx = fanout_demux_rollover(f, skb, idx, true, num);
1508 
1509 	po = pkt_sk(rcu_dereference(f->arr[idx]));
1510 	return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1511 }
1512 
1513 DEFINE_MUTEX(fanout_mutex);
1514 EXPORT_SYMBOL_GPL(fanout_mutex);
1515 static LIST_HEAD(fanout_list);
1516 static u16 fanout_next_id;
1517 
1518 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1519 {
1520 	struct packet_fanout *f = po->fanout;
1521 
1522 	spin_lock(&f->lock);
1523 	rcu_assign_pointer(f->arr[f->num_members], sk);
1524 	smp_wmb();
1525 	f->num_members++;
1526 	if (f->num_members == 1)
1527 		dev_add_pack(&f->prot_hook);
1528 	spin_unlock(&f->lock);
1529 }
1530 
1531 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1532 {
1533 	struct packet_fanout *f = po->fanout;
1534 	int i;
1535 
1536 	spin_lock(&f->lock);
1537 	for (i = 0; i < f->num_members; i++) {
1538 		if (rcu_dereference_protected(f->arr[i],
1539 					      lockdep_is_held(&f->lock)) == sk)
1540 			break;
1541 	}
1542 	BUG_ON(i >= f->num_members);
1543 	rcu_assign_pointer(f->arr[i],
1544 			   rcu_dereference_protected(f->arr[f->num_members - 1],
1545 						     lockdep_is_held(&f->lock)));
1546 	f->num_members--;
1547 	if (f->num_members == 0)
1548 		__dev_remove_pack(&f->prot_hook);
1549 	spin_unlock(&f->lock);
1550 }
1551 
1552 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1553 {
1554 	if (sk->sk_family != PF_PACKET)
1555 		return false;
1556 
1557 	return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1558 }
1559 
1560 static void fanout_init_data(struct packet_fanout *f)
1561 {
1562 	switch (f->type) {
1563 	case PACKET_FANOUT_LB:
1564 		atomic_set(&f->rr_cur, 0);
1565 		break;
1566 	case PACKET_FANOUT_CBPF:
1567 	case PACKET_FANOUT_EBPF:
1568 		RCU_INIT_POINTER(f->bpf_prog, NULL);
1569 		break;
1570 	}
1571 }
1572 
1573 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1574 {
1575 	struct bpf_prog *old;
1576 
1577 	spin_lock(&f->lock);
1578 	old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1579 	rcu_assign_pointer(f->bpf_prog, new);
1580 	spin_unlock(&f->lock);
1581 
1582 	if (old) {
1583 		synchronize_net();
1584 		bpf_prog_destroy(old);
1585 	}
1586 }
1587 
1588 static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data,
1589 				unsigned int len)
1590 {
1591 	struct bpf_prog *new;
1592 	struct sock_fprog fprog;
1593 	int ret;
1594 
1595 	if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1596 		return -EPERM;
1597 
1598 	ret = copy_bpf_fprog_from_user(&fprog, data, len);
1599 	if (ret)
1600 		return ret;
1601 
1602 	ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1603 	if (ret)
1604 		return ret;
1605 
1606 	__fanout_set_data_bpf(po->fanout, new);
1607 	return 0;
1608 }
1609 
1610 static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data,
1611 				unsigned int len)
1612 {
1613 	struct bpf_prog *new;
1614 	u32 fd;
1615 
1616 	if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1617 		return -EPERM;
1618 	if (len != sizeof(fd))
1619 		return -EINVAL;
1620 	if (copy_from_sockptr(&fd, data, len))
1621 		return -EFAULT;
1622 
1623 	new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1624 	if (IS_ERR(new))
1625 		return PTR_ERR(new);
1626 
1627 	__fanout_set_data_bpf(po->fanout, new);
1628 	return 0;
1629 }
1630 
1631 static int fanout_set_data(struct packet_sock *po, sockptr_t data,
1632 			   unsigned int len)
1633 {
1634 	switch (po->fanout->type) {
1635 	case PACKET_FANOUT_CBPF:
1636 		return fanout_set_data_cbpf(po, data, len);
1637 	case PACKET_FANOUT_EBPF:
1638 		return fanout_set_data_ebpf(po, data, len);
1639 	default:
1640 		return -EINVAL;
1641 	}
1642 }
1643 
1644 static void fanout_release_data(struct packet_fanout *f)
1645 {
1646 	switch (f->type) {
1647 	case PACKET_FANOUT_CBPF:
1648 	case PACKET_FANOUT_EBPF:
1649 		__fanout_set_data_bpf(f, NULL);
1650 	}
1651 }
1652 
1653 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1654 {
1655 	struct packet_fanout *f;
1656 
1657 	list_for_each_entry(f, &fanout_list, list) {
1658 		if (f->id == candidate_id &&
1659 		    read_pnet(&f->net) == sock_net(sk)) {
1660 			return false;
1661 		}
1662 	}
1663 	return true;
1664 }
1665 
1666 static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1667 {
1668 	u16 id = fanout_next_id;
1669 
1670 	do {
1671 		if (__fanout_id_is_free(sk, id)) {
1672 			*new_id = id;
1673 			fanout_next_id = id + 1;
1674 			return true;
1675 		}
1676 
1677 		id++;
1678 	} while (id != fanout_next_id);
1679 
1680 	return false;
1681 }
1682 
1683 static int fanout_add(struct sock *sk, struct fanout_args *args)
1684 {
1685 	struct packet_rollover *rollover = NULL;
1686 	struct packet_sock *po = pkt_sk(sk);
1687 	u16 type_flags = args->type_flags;
1688 	struct packet_fanout *f, *match;
1689 	u8 type = type_flags & 0xff;
1690 	u8 flags = type_flags >> 8;
1691 	u16 id = args->id;
1692 	int err;
1693 
1694 	switch (type) {
1695 	case PACKET_FANOUT_ROLLOVER:
1696 		if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1697 			return -EINVAL;
1698 		break;
1699 	case PACKET_FANOUT_HASH:
1700 	case PACKET_FANOUT_LB:
1701 	case PACKET_FANOUT_CPU:
1702 	case PACKET_FANOUT_RND:
1703 	case PACKET_FANOUT_QM:
1704 	case PACKET_FANOUT_CBPF:
1705 	case PACKET_FANOUT_EBPF:
1706 		break;
1707 	default:
1708 		return -EINVAL;
1709 	}
1710 
1711 	mutex_lock(&fanout_mutex);
1712 
1713 	err = -EALREADY;
1714 	if (po->fanout)
1715 		goto out;
1716 
1717 	if (type == PACKET_FANOUT_ROLLOVER ||
1718 	    (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1719 		err = -ENOMEM;
1720 		rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1721 		if (!rollover)
1722 			goto out;
1723 		atomic_long_set(&rollover->num, 0);
1724 		atomic_long_set(&rollover->num_huge, 0);
1725 		atomic_long_set(&rollover->num_failed, 0);
1726 	}
1727 
1728 	if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1729 		if (id != 0) {
1730 			err = -EINVAL;
1731 			goto out;
1732 		}
1733 		if (!fanout_find_new_id(sk, &id)) {
1734 			err = -ENOMEM;
1735 			goto out;
1736 		}
1737 		/* ephemeral flag for the first socket in the group: drop it */
1738 		flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1739 	}
1740 
1741 	match = NULL;
1742 	list_for_each_entry(f, &fanout_list, list) {
1743 		if (f->id == id &&
1744 		    read_pnet(&f->net) == sock_net(sk)) {
1745 			match = f;
1746 			break;
1747 		}
1748 	}
1749 	err = -EINVAL;
1750 	if (match) {
1751 		if (match->flags != flags)
1752 			goto out;
1753 		if (args->max_num_members &&
1754 		    args->max_num_members != match->max_num_members)
1755 			goto out;
1756 	} else {
1757 		if (args->max_num_members > PACKET_FANOUT_MAX)
1758 			goto out;
1759 		if (!args->max_num_members)
1760 			/* legacy PACKET_FANOUT_MAX */
1761 			args->max_num_members = 256;
1762 		err = -ENOMEM;
1763 		match = kvzalloc(struct_size(match, arr, args->max_num_members),
1764 				 GFP_KERNEL);
1765 		if (!match)
1766 			goto out;
1767 		write_pnet(&match->net, sock_net(sk));
1768 		match->id = id;
1769 		match->type = type;
1770 		match->flags = flags;
1771 		INIT_LIST_HEAD(&match->list);
1772 		spin_lock_init(&match->lock);
1773 		refcount_set(&match->sk_ref, 0);
1774 		fanout_init_data(match);
1775 		match->prot_hook.type = po->prot_hook.type;
1776 		match->prot_hook.dev = po->prot_hook.dev;
1777 		match->prot_hook.func = packet_rcv_fanout;
1778 		match->prot_hook.af_packet_priv = match;
1779 		match->prot_hook.af_packet_net = read_pnet(&match->net);
1780 		match->prot_hook.id_match = match_fanout_group;
1781 		match->max_num_members = args->max_num_members;
1782 		match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING;
1783 		list_add(&match->list, &fanout_list);
1784 	}
1785 	err = -EINVAL;
1786 
1787 	spin_lock(&po->bind_lock);
1788 	if (packet_sock_flag(po, PACKET_SOCK_RUNNING) &&
1789 	    match->type == type &&
1790 	    match->prot_hook.type == po->prot_hook.type &&
1791 	    match->prot_hook.dev == po->prot_hook.dev) {
1792 		err = -ENOSPC;
1793 		if (refcount_read(&match->sk_ref) < match->max_num_members) {
1794 			__dev_remove_pack(&po->prot_hook);
1795 
1796 			/* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */
1797 			WRITE_ONCE(po->fanout, match);
1798 
1799 			po->rollover = rollover;
1800 			rollover = NULL;
1801 			refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1802 			__fanout_link(sk, po);
1803 			err = 0;
1804 		}
1805 	}
1806 	spin_unlock(&po->bind_lock);
1807 
1808 	if (err && !refcount_read(&match->sk_ref)) {
1809 		list_del(&match->list);
1810 		kvfree(match);
1811 	}
1812 
1813 out:
1814 	kfree(rollover);
1815 	mutex_unlock(&fanout_mutex);
1816 	return err;
1817 }
1818 
1819 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1820  * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1821  * It is the responsibility of the caller to call fanout_release_data() and
1822  * free the returned packet_fanout (after synchronize_net())
1823  */
1824 static struct packet_fanout *fanout_release(struct sock *sk)
1825 {
1826 	struct packet_sock *po = pkt_sk(sk);
1827 	struct packet_fanout *f;
1828 
1829 	mutex_lock(&fanout_mutex);
1830 	f = po->fanout;
1831 	if (f) {
1832 		po->fanout = NULL;
1833 
1834 		if (refcount_dec_and_test(&f->sk_ref))
1835 			list_del(&f->list);
1836 		else
1837 			f = NULL;
1838 	}
1839 	mutex_unlock(&fanout_mutex);
1840 
1841 	return f;
1842 }
1843 
1844 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1845 					  struct sk_buff *skb)
1846 {
1847 	/* Earlier code assumed this would be a VLAN pkt, double-check
1848 	 * this now that we have the actual packet in hand. We can only
1849 	 * do this check on Ethernet devices.
1850 	 */
1851 	if (unlikely(dev->type != ARPHRD_ETHER))
1852 		return false;
1853 
1854 	skb_reset_mac_header(skb);
1855 	return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1856 }
1857 
1858 static const struct proto_ops packet_ops;
1859 
1860 static const struct proto_ops packet_ops_spkt;
1861 
1862 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1863 			   struct packet_type *pt, struct net_device *orig_dev)
1864 {
1865 	struct sock *sk;
1866 	struct sockaddr_pkt *spkt;
1867 
1868 	/*
1869 	 *	When we registered the protocol we saved the socket in the data
1870 	 *	field for just this event.
1871 	 */
1872 
1873 	sk = pt->af_packet_priv;
1874 
1875 	/*
1876 	 *	Yank back the headers [hope the device set this
1877 	 *	right or kerboom...]
1878 	 *
1879 	 *	Incoming packets have ll header pulled,
1880 	 *	push it back.
1881 	 *
1882 	 *	For outgoing ones skb->data == skb_mac_header(skb)
1883 	 *	so that this procedure is noop.
1884 	 */
1885 
1886 	if (skb->pkt_type == PACKET_LOOPBACK)
1887 		goto out;
1888 
1889 	if (!net_eq(dev_net(dev), sock_net(sk)))
1890 		goto out;
1891 
1892 	skb = skb_share_check(skb, GFP_ATOMIC);
1893 	if (skb == NULL)
1894 		goto oom;
1895 
1896 	/* drop any routing info */
1897 	skb_dst_drop(skb);
1898 
1899 	/* drop conntrack reference */
1900 	nf_reset_ct(skb);
1901 
1902 	spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1903 
1904 	skb_push(skb, skb->data - skb_mac_header(skb));
1905 
1906 	/*
1907 	 *	The SOCK_PACKET socket receives _all_ frames.
1908 	 */
1909 
1910 	spkt->spkt_family = dev->type;
1911 	strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1912 	spkt->spkt_protocol = skb->protocol;
1913 
1914 	/*
1915 	 *	Charge the memory to the socket. This is done specifically
1916 	 *	to prevent sockets using all the memory up.
1917 	 */
1918 
1919 	if (sock_queue_rcv_skb(sk, skb) == 0)
1920 		return 0;
1921 
1922 out:
1923 	kfree_skb(skb);
1924 oom:
1925 	return 0;
1926 }
1927 
1928 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1929 {
1930 	int depth;
1931 
1932 	if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1933 	    sock->type == SOCK_RAW) {
1934 		skb_reset_mac_header(skb);
1935 		skb->protocol = dev_parse_header_protocol(skb);
1936 	}
1937 
1938 	/* Move network header to the right position for VLAN tagged packets */
1939 	if (likely(skb->dev->type == ARPHRD_ETHER) &&
1940 	    eth_type_vlan(skb->protocol) &&
1941 	    vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0)
1942 		skb_set_network_header(skb, depth);
1943 
1944 	skb_probe_transport_header(skb);
1945 }
1946 
1947 /*
1948  *	Output a raw packet to a device layer. This bypasses all the other
1949  *	protocol layers and you must therefore supply it with a complete frame
1950  */
1951 
1952 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1953 			       size_t len)
1954 {
1955 	struct sock *sk = sock->sk;
1956 	DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1957 	struct sk_buff *skb = NULL;
1958 	struct net_device *dev;
1959 	struct sockcm_cookie sockc;
1960 	__be16 proto = 0;
1961 	int err;
1962 	int extra_len = 0;
1963 
1964 	/*
1965 	 *	Get and verify the address.
1966 	 */
1967 
1968 	if (saddr) {
1969 		if (msg->msg_namelen < sizeof(struct sockaddr))
1970 			return -EINVAL;
1971 		if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1972 			proto = saddr->spkt_protocol;
1973 	} else
1974 		return -ENOTCONN;	/* SOCK_PACKET must be sent giving an address */
1975 
1976 	/*
1977 	 *	Find the device first to size check it
1978 	 */
1979 
1980 	saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1981 retry:
1982 	rcu_read_lock();
1983 	dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1984 	err = -ENODEV;
1985 	if (dev == NULL)
1986 		goto out_unlock;
1987 
1988 	err = -ENETDOWN;
1989 	if (!(dev->flags & IFF_UP))
1990 		goto out_unlock;
1991 
1992 	/*
1993 	 * You may not queue a frame bigger than the mtu. This is the lowest level
1994 	 * raw protocol and you must do your own fragmentation at this level.
1995 	 */
1996 
1997 	if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1998 		if (!netif_supports_nofcs(dev)) {
1999 			err = -EPROTONOSUPPORT;
2000 			goto out_unlock;
2001 		}
2002 		extra_len = 4; /* We're doing our own CRC */
2003 	}
2004 
2005 	err = -EMSGSIZE;
2006 	if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
2007 		goto out_unlock;
2008 
2009 	if (!skb) {
2010 		size_t reserved = LL_RESERVED_SPACE(dev);
2011 		int tlen = dev->needed_tailroom;
2012 		unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
2013 
2014 		rcu_read_unlock();
2015 		skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
2016 		if (skb == NULL)
2017 			return -ENOBUFS;
2018 		/* FIXME: Save some space for broken drivers that write a hard
2019 		 * header at transmission time by themselves. PPP is the notable
2020 		 * one here. This should really be fixed at the driver level.
2021 		 */
2022 		skb_reserve(skb, reserved);
2023 		skb_reset_network_header(skb);
2024 
2025 		/* Try to align data part correctly */
2026 		if (hhlen) {
2027 			skb->data -= hhlen;
2028 			skb->tail -= hhlen;
2029 			if (len < hhlen)
2030 				skb_reset_network_header(skb);
2031 		}
2032 		err = memcpy_from_msg(skb_put(skb, len), msg, len);
2033 		if (err)
2034 			goto out_free;
2035 		goto retry;
2036 	}
2037 
2038 	if (!dev_validate_header(dev, skb->data, len) || !skb->len) {
2039 		err = -EINVAL;
2040 		goto out_unlock;
2041 	}
2042 	if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
2043 	    !packet_extra_vlan_len_allowed(dev, skb)) {
2044 		err = -EMSGSIZE;
2045 		goto out_unlock;
2046 	}
2047 
2048 	sockcm_init(&sockc, sk);
2049 	if (msg->msg_controllen) {
2050 		err = sock_cmsg_send(sk, msg, &sockc);
2051 		if (unlikely(err))
2052 			goto out_unlock;
2053 	}
2054 
2055 	skb->protocol = proto;
2056 	skb->dev = dev;
2057 	skb->priority = READ_ONCE(sk->sk_priority);
2058 	skb->mark = READ_ONCE(sk->sk_mark);
2059 	skb->tstamp = sockc.transmit_time;
2060 
2061 	skb_setup_tx_timestamp(skb, sockc.tsflags);
2062 
2063 	if (unlikely(extra_len == 4))
2064 		skb->no_fcs = 1;
2065 
2066 	packet_parse_headers(skb, sock);
2067 
2068 	dev_queue_xmit(skb);
2069 	rcu_read_unlock();
2070 	return len;
2071 
2072 out_unlock:
2073 	rcu_read_unlock();
2074 out_free:
2075 	kfree_skb(skb);
2076 	return err;
2077 }
2078 
2079 static unsigned int run_filter(struct sk_buff *skb,
2080 			       const struct sock *sk,
2081 			       unsigned int res)
2082 {
2083 	struct sk_filter *filter;
2084 
2085 	rcu_read_lock();
2086 	filter = rcu_dereference(sk->sk_filter);
2087 	if (filter != NULL)
2088 		res = bpf_prog_run_clear_cb(filter->prog, skb);
2089 	rcu_read_unlock();
2090 
2091 	return res;
2092 }
2093 
2094 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2095 			   size_t *len, int vnet_hdr_sz)
2096 {
2097 	struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 };
2098 
2099 	if (*len < vnet_hdr_sz)
2100 		return -EINVAL;
2101 	*len -= vnet_hdr_sz;
2102 
2103 	if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0))
2104 		return -EINVAL;
2105 
2106 	return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz);
2107 }
2108 
2109 /*
2110  * This function makes lazy skb cloning in hope that most of packets
2111  * are discarded by BPF.
2112  *
2113  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2114  * and skb->cb are mangled. It works because (and until) packets
2115  * falling here are owned by current CPU. Output packets are cloned
2116  * by dev_queue_xmit_nit(), input packets are processed by net_bh
2117  * sequentially, so that if we return skb to original state on exit,
2118  * we will not harm anyone.
2119  */
2120 
2121 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2122 		      struct packet_type *pt, struct net_device *orig_dev)
2123 {
2124 	enum skb_drop_reason drop_reason = SKB_CONSUMED;
2125 	struct sock *sk;
2126 	struct sockaddr_ll *sll;
2127 	struct packet_sock *po;
2128 	u8 *skb_head = skb->data;
2129 	int skb_len = skb->len;
2130 	unsigned int snaplen, res;
2131 
2132 	if (skb->pkt_type == PACKET_LOOPBACK)
2133 		goto drop;
2134 
2135 	sk = pt->af_packet_priv;
2136 	po = pkt_sk(sk);
2137 
2138 	if (!net_eq(dev_net(dev), sock_net(sk)))
2139 		goto drop;
2140 
2141 	skb->dev = dev;
2142 
2143 	if (dev_has_header(dev)) {
2144 		/* The device has an explicit notion of ll header,
2145 		 * exported to higher levels.
2146 		 *
2147 		 * Otherwise, the device hides details of its frame
2148 		 * structure, so that corresponding packet head is
2149 		 * never delivered to user.
2150 		 */
2151 		if (sk->sk_type != SOCK_DGRAM)
2152 			skb_push(skb, skb->data - skb_mac_header(skb));
2153 		else if (skb->pkt_type == PACKET_OUTGOING) {
2154 			/* Special case: outgoing packets have ll header at head */
2155 			skb_pull(skb, skb_network_offset(skb));
2156 		}
2157 	}
2158 
2159 	snaplen = skb->len;
2160 
2161 	res = run_filter(skb, sk, snaplen);
2162 	if (!res)
2163 		goto drop_n_restore;
2164 	if (snaplen > res)
2165 		snaplen = res;
2166 
2167 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2168 		goto drop_n_acct;
2169 
2170 	if (skb_shared(skb)) {
2171 		struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2172 		if (nskb == NULL)
2173 			goto drop_n_acct;
2174 
2175 		if (skb_head != skb->data) {
2176 			skb->data = skb_head;
2177 			skb->len = skb_len;
2178 		}
2179 		consume_skb(skb);
2180 		skb = nskb;
2181 	}
2182 
2183 	sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2184 
2185 	sll = &PACKET_SKB_CB(skb)->sa.ll;
2186 	sll->sll_hatype = dev->type;
2187 	sll->sll_pkttype = skb->pkt_type;
2188 	if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
2189 		sll->sll_ifindex = orig_dev->ifindex;
2190 	else
2191 		sll->sll_ifindex = dev->ifindex;
2192 
2193 	sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2194 
2195 	/* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2196 	 * Use their space for storing the original skb length.
2197 	 */
2198 	PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2199 
2200 	if (pskb_trim(skb, snaplen))
2201 		goto drop_n_acct;
2202 
2203 	skb_set_owner_r(skb, sk);
2204 	skb->dev = NULL;
2205 	skb_dst_drop(skb);
2206 
2207 	/* drop conntrack reference */
2208 	nf_reset_ct(skb);
2209 
2210 	spin_lock(&sk->sk_receive_queue.lock);
2211 	po->stats.stats1.tp_packets++;
2212 	sock_skb_set_dropcount(sk, skb);
2213 	skb_clear_delivery_time(skb);
2214 	__skb_queue_tail(&sk->sk_receive_queue, skb);
2215 	spin_unlock(&sk->sk_receive_queue.lock);
2216 	sk->sk_data_ready(sk);
2217 	return 0;
2218 
2219 drop_n_acct:
2220 	atomic_inc(&po->tp_drops);
2221 	atomic_inc(&sk->sk_drops);
2222 	drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR;
2223 
2224 drop_n_restore:
2225 	if (skb_head != skb->data && skb_shared(skb)) {
2226 		skb->data = skb_head;
2227 		skb->len = skb_len;
2228 	}
2229 drop:
2230 	kfree_skb_reason(skb, drop_reason);
2231 	return 0;
2232 }
2233 
2234 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2235 		       struct packet_type *pt, struct net_device *orig_dev)
2236 {
2237 	enum skb_drop_reason drop_reason = SKB_CONSUMED;
2238 	struct sock *sk;
2239 	struct packet_sock *po;
2240 	struct sockaddr_ll *sll;
2241 	union tpacket_uhdr h;
2242 	u8 *skb_head = skb->data;
2243 	int skb_len = skb->len;
2244 	unsigned int snaplen, res;
2245 	unsigned long status = TP_STATUS_USER;
2246 	unsigned short macoff, hdrlen;
2247 	unsigned int netoff;
2248 	struct sk_buff *copy_skb = NULL;
2249 	struct timespec64 ts;
2250 	__u32 ts_status;
2251 	unsigned int slot_id = 0;
2252 	int vnet_hdr_sz = 0;
2253 
2254 	/* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2255 	 * We may add members to them until current aligned size without forcing
2256 	 * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2257 	 */
2258 	BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2259 	BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2260 
2261 	if (skb->pkt_type == PACKET_LOOPBACK)
2262 		goto drop;
2263 
2264 	sk = pt->af_packet_priv;
2265 	po = pkt_sk(sk);
2266 
2267 	if (!net_eq(dev_net(dev), sock_net(sk)))
2268 		goto drop;
2269 
2270 	if (dev_has_header(dev)) {
2271 		if (sk->sk_type != SOCK_DGRAM)
2272 			skb_push(skb, skb->data - skb_mac_header(skb));
2273 		else if (skb->pkt_type == PACKET_OUTGOING) {
2274 			/* Special case: outgoing packets have ll header at head */
2275 			skb_pull(skb, skb_network_offset(skb));
2276 		}
2277 	}
2278 
2279 	snaplen = skb->len;
2280 
2281 	res = run_filter(skb, sk, snaplen);
2282 	if (!res)
2283 		goto drop_n_restore;
2284 
2285 	/* If we are flooded, just give up */
2286 	if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2287 		atomic_inc(&po->tp_drops);
2288 		goto drop_n_restore;
2289 	}
2290 
2291 	if (skb->ip_summed == CHECKSUM_PARTIAL)
2292 		status |= TP_STATUS_CSUMNOTREADY;
2293 	else if (skb->pkt_type != PACKET_OUTGOING &&
2294 		 skb_csum_unnecessary(skb))
2295 		status |= TP_STATUS_CSUM_VALID;
2296 	if (skb_is_gso(skb) && skb_is_gso_tcp(skb))
2297 		status |= TP_STATUS_GSO_TCP;
2298 
2299 	if (snaplen > res)
2300 		snaplen = res;
2301 
2302 	if (sk->sk_type == SOCK_DGRAM) {
2303 		macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2304 				  po->tp_reserve;
2305 	} else {
2306 		unsigned int maclen = skb_network_offset(skb);
2307 		netoff = TPACKET_ALIGN(po->tp_hdrlen +
2308 				       (maclen < 16 ? 16 : maclen)) +
2309 				       po->tp_reserve;
2310 		vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
2311 		if (vnet_hdr_sz)
2312 			netoff += vnet_hdr_sz;
2313 		macoff = netoff - maclen;
2314 	}
2315 	if (netoff > USHRT_MAX) {
2316 		atomic_inc(&po->tp_drops);
2317 		goto drop_n_restore;
2318 	}
2319 	if (po->tp_version <= TPACKET_V2) {
2320 		if (macoff + snaplen > po->rx_ring.frame_size) {
2321 			if (po->copy_thresh &&
2322 			    atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2323 				if (skb_shared(skb)) {
2324 					copy_skb = skb_clone(skb, GFP_ATOMIC);
2325 				} else {
2326 					copy_skb = skb_get(skb);
2327 					skb_head = skb->data;
2328 				}
2329 				if (copy_skb) {
2330 					memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0,
2331 					       sizeof(PACKET_SKB_CB(copy_skb)->sa.ll));
2332 					skb_set_owner_r(copy_skb, sk);
2333 				}
2334 			}
2335 			snaplen = po->rx_ring.frame_size - macoff;
2336 			if ((int)snaplen < 0) {
2337 				snaplen = 0;
2338 				vnet_hdr_sz = 0;
2339 			}
2340 		}
2341 	} else if (unlikely(macoff + snaplen >
2342 			    GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2343 		u32 nval;
2344 
2345 		nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2346 		pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2347 			    snaplen, nval, macoff);
2348 		snaplen = nval;
2349 		if (unlikely((int)snaplen < 0)) {
2350 			snaplen = 0;
2351 			macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2352 			vnet_hdr_sz = 0;
2353 		}
2354 	}
2355 	spin_lock(&sk->sk_receive_queue.lock);
2356 	h.raw = packet_current_rx_frame(po, skb,
2357 					TP_STATUS_KERNEL, (macoff+snaplen));
2358 	if (!h.raw)
2359 		goto drop_n_account;
2360 
2361 	if (po->tp_version <= TPACKET_V2) {
2362 		slot_id = po->rx_ring.head;
2363 		if (test_bit(slot_id, po->rx_ring.rx_owner_map))
2364 			goto drop_n_account;
2365 		__set_bit(slot_id, po->rx_ring.rx_owner_map);
2366 	}
2367 
2368 	if (vnet_hdr_sz &&
2369 	    virtio_net_hdr_from_skb(skb, h.raw + macoff -
2370 				    sizeof(struct virtio_net_hdr),
2371 				    vio_le(), true, 0)) {
2372 		if (po->tp_version == TPACKET_V3)
2373 			prb_clear_blk_fill_status(&po->rx_ring);
2374 		goto drop_n_account;
2375 	}
2376 
2377 	if (po->tp_version <= TPACKET_V2) {
2378 		packet_increment_rx_head(po, &po->rx_ring);
2379 	/*
2380 	 * LOSING will be reported till you read the stats,
2381 	 * because it's COR - Clear On Read.
2382 	 * Anyways, moving it for V1/V2 only as V3 doesn't need this
2383 	 * at packet level.
2384 	 */
2385 		if (atomic_read(&po->tp_drops))
2386 			status |= TP_STATUS_LOSING;
2387 	}
2388 
2389 	po->stats.stats1.tp_packets++;
2390 	if (copy_skb) {
2391 		status |= TP_STATUS_COPY;
2392 		skb_clear_delivery_time(copy_skb);
2393 		__skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2394 	}
2395 	spin_unlock(&sk->sk_receive_queue.lock);
2396 
2397 	skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2398 
2399 	/* Always timestamp; prefer an existing software timestamp taken
2400 	 * closer to the time of capture.
2401 	 */
2402 	ts_status = tpacket_get_timestamp(skb, &ts,
2403 					  READ_ONCE(po->tp_tstamp) |
2404 					  SOF_TIMESTAMPING_SOFTWARE);
2405 	if (!ts_status)
2406 		ktime_get_real_ts64(&ts);
2407 
2408 	status |= ts_status;
2409 
2410 	switch (po->tp_version) {
2411 	case TPACKET_V1:
2412 		h.h1->tp_len = skb->len;
2413 		h.h1->tp_snaplen = snaplen;
2414 		h.h1->tp_mac = macoff;
2415 		h.h1->tp_net = netoff;
2416 		h.h1->tp_sec = ts.tv_sec;
2417 		h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2418 		hdrlen = sizeof(*h.h1);
2419 		break;
2420 	case TPACKET_V2:
2421 		h.h2->tp_len = skb->len;
2422 		h.h2->tp_snaplen = snaplen;
2423 		h.h2->tp_mac = macoff;
2424 		h.h2->tp_net = netoff;
2425 		h.h2->tp_sec = ts.tv_sec;
2426 		h.h2->tp_nsec = ts.tv_nsec;
2427 		if (skb_vlan_tag_present(skb)) {
2428 			h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2429 			h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2430 			status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2431 		} else {
2432 			h.h2->tp_vlan_tci = 0;
2433 			h.h2->tp_vlan_tpid = 0;
2434 		}
2435 		memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2436 		hdrlen = sizeof(*h.h2);
2437 		break;
2438 	case TPACKET_V3:
2439 		/* tp_nxt_offset,vlan are already populated above.
2440 		 * So DONT clear those fields here
2441 		 */
2442 		h.h3->tp_status |= status;
2443 		h.h3->tp_len = skb->len;
2444 		h.h3->tp_snaplen = snaplen;
2445 		h.h3->tp_mac = macoff;
2446 		h.h3->tp_net = netoff;
2447 		h.h3->tp_sec  = ts.tv_sec;
2448 		h.h3->tp_nsec = ts.tv_nsec;
2449 		memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2450 		hdrlen = sizeof(*h.h3);
2451 		break;
2452 	default:
2453 		BUG();
2454 	}
2455 
2456 	sll = h.raw + TPACKET_ALIGN(hdrlen);
2457 	sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2458 	sll->sll_family = AF_PACKET;
2459 	sll->sll_hatype = dev->type;
2460 	sll->sll_protocol = skb->protocol;
2461 	sll->sll_pkttype = skb->pkt_type;
2462 	if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
2463 		sll->sll_ifindex = orig_dev->ifindex;
2464 	else
2465 		sll->sll_ifindex = dev->ifindex;
2466 
2467 	smp_mb();
2468 
2469 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2470 	if (po->tp_version <= TPACKET_V2) {
2471 		u8 *start, *end;
2472 
2473 		end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2474 					macoff + snaplen);
2475 
2476 		for (start = h.raw; start < end; start += PAGE_SIZE)
2477 			flush_dcache_page(pgv_to_page(start));
2478 	}
2479 	smp_wmb();
2480 #endif
2481 
2482 	if (po->tp_version <= TPACKET_V2) {
2483 		spin_lock(&sk->sk_receive_queue.lock);
2484 		__packet_set_status(po, h.raw, status);
2485 		__clear_bit(slot_id, po->rx_ring.rx_owner_map);
2486 		spin_unlock(&sk->sk_receive_queue.lock);
2487 		sk->sk_data_ready(sk);
2488 	} else if (po->tp_version == TPACKET_V3) {
2489 		prb_clear_blk_fill_status(&po->rx_ring);
2490 	}
2491 
2492 drop_n_restore:
2493 	if (skb_head != skb->data && skb_shared(skb)) {
2494 		skb->data = skb_head;
2495 		skb->len = skb_len;
2496 	}
2497 drop:
2498 	kfree_skb_reason(skb, drop_reason);
2499 	return 0;
2500 
2501 drop_n_account:
2502 	spin_unlock(&sk->sk_receive_queue.lock);
2503 	atomic_inc(&po->tp_drops);
2504 	drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR;
2505 
2506 	sk->sk_data_ready(sk);
2507 	kfree_skb_reason(copy_skb, drop_reason);
2508 	goto drop_n_restore;
2509 }
2510 
2511 static void tpacket_destruct_skb(struct sk_buff *skb)
2512 {
2513 	struct packet_sock *po = pkt_sk(skb->sk);
2514 
2515 	if (likely(po->tx_ring.pg_vec)) {
2516 		void *ph;
2517 		__u32 ts;
2518 
2519 		ph = skb_zcopy_get_nouarg(skb);
2520 		packet_dec_pending(&po->tx_ring);
2521 
2522 		ts = __packet_set_timestamp(po, ph, skb);
2523 		__packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2524 
2525 		if (!packet_read_pending(&po->tx_ring))
2526 			complete(&po->skb_completion);
2527 	}
2528 
2529 	sock_wfree(skb);
2530 }
2531 
2532 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2533 {
2534 	if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2535 	    (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2536 	     __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2537 	      __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2538 		vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2539 			 __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2540 			__virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2541 
2542 	if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2543 		return -EINVAL;
2544 
2545 	return 0;
2546 }
2547 
2548 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2549 				 struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz)
2550 {
2551 	int ret;
2552 
2553 	if (*len < vnet_hdr_sz)
2554 		return -EINVAL;
2555 	*len -= vnet_hdr_sz;
2556 
2557 	if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2558 		return -EFAULT;
2559 
2560 	ret = __packet_snd_vnet_parse(vnet_hdr, *len);
2561 	if (ret)
2562 		return ret;
2563 
2564 	/* move iter to point to the start of mac header */
2565 	if (vnet_hdr_sz != sizeof(struct virtio_net_hdr))
2566 		iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr));
2567 
2568 	return 0;
2569 }
2570 
2571 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2572 		void *frame, struct net_device *dev, void *data, int tp_len,
2573 		__be16 proto, unsigned char *addr, int hlen, int copylen,
2574 		const struct sockcm_cookie *sockc)
2575 {
2576 	union tpacket_uhdr ph;
2577 	int to_write, offset, len, nr_frags, len_max;
2578 	struct socket *sock = po->sk.sk_socket;
2579 	struct page *page;
2580 	int err;
2581 
2582 	ph.raw = frame;
2583 
2584 	skb->protocol = proto;
2585 	skb->dev = dev;
2586 	skb->priority = READ_ONCE(po->sk.sk_priority);
2587 	skb->mark = READ_ONCE(po->sk.sk_mark);
2588 	skb->tstamp = sockc->transmit_time;
2589 	skb_setup_tx_timestamp(skb, sockc->tsflags);
2590 	skb_zcopy_set_nouarg(skb, ph.raw);
2591 
2592 	skb_reserve(skb, hlen);
2593 	skb_reset_network_header(skb);
2594 
2595 	to_write = tp_len;
2596 
2597 	if (sock->type == SOCK_DGRAM) {
2598 		err = dev_hard_header(skb, dev, ntohs(proto), addr,
2599 				NULL, tp_len);
2600 		if (unlikely(err < 0))
2601 			return -EINVAL;
2602 	} else if (copylen) {
2603 		int hdrlen = min_t(int, copylen, tp_len);
2604 
2605 		skb_push(skb, dev->hard_header_len);
2606 		skb_put(skb, copylen - dev->hard_header_len);
2607 		err = skb_store_bits(skb, 0, data, hdrlen);
2608 		if (unlikely(err))
2609 			return err;
2610 		if (!dev_validate_header(dev, skb->data, hdrlen))
2611 			return -EINVAL;
2612 
2613 		data += hdrlen;
2614 		to_write -= hdrlen;
2615 	}
2616 
2617 	offset = offset_in_page(data);
2618 	len_max = PAGE_SIZE - offset;
2619 	len = ((to_write > len_max) ? len_max : to_write);
2620 
2621 	skb->data_len = to_write;
2622 	skb->len += to_write;
2623 	skb->truesize += to_write;
2624 	refcount_add(to_write, &po->sk.sk_wmem_alloc);
2625 
2626 	while (likely(to_write)) {
2627 		nr_frags = skb_shinfo(skb)->nr_frags;
2628 
2629 		if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2630 			pr_err("Packet exceed the number of skb frags(%u)\n",
2631 			       (unsigned int)MAX_SKB_FRAGS);
2632 			return -EFAULT;
2633 		}
2634 
2635 		page = pgv_to_page(data);
2636 		data += len;
2637 		flush_dcache_page(page);
2638 		get_page(page);
2639 		skb_fill_page_desc(skb, nr_frags, page, offset, len);
2640 		to_write -= len;
2641 		offset = 0;
2642 		len_max = PAGE_SIZE;
2643 		len = ((to_write > len_max) ? len_max : to_write);
2644 	}
2645 
2646 	packet_parse_headers(skb, sock);
2647 
2648 	return tp_len;
2649 }
2650 
2651 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2652 				int size_max, void **data)
2653 {
2654 	union tpacket_uhdr ph;
2655 	int tp_len, off;
2656 
2657 	ph.raw = frame;
2658 
2659 	switch (po->tp_version) {
2660 	case TPACKET_V3:
2661 		if (ph.h3->tp_next_offset != 0) {
2662 			pr_warn_once("variable sized slot not supported");
2663 			return -EINVAL;
2664 		}
2665 		tp_len = ph.h3->tp_len;
2666 		break;
2667 	case TPACKET_V2:
2668 		tp_len = ph.h2->tp_len;
2669 		break;
2670 	default:
2671 		tp_len = ph.h1->tp_len;
2672 		break;
2673 	}
2674 	if (unlikely(tp_len > size_max)) {
2675 		pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2676 		return -EMSGSIZE;
2677 	}
2678 
2679 	if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) {
2680 		int off_min, off_max;
2681 
2682 		off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2683 		off_max = po->tx_ring.frame_size - tp_len;
2684 		if (po->sk.sk_type == SOCK_DGRAM) {
2685 			switch (po->tp_version) {
2686 			case TPACKET_V3:
2687 				off = ph.h3->tp_net;
2688 				break;
2689 			case TPACKET_V2:
2690 				off = ph.h2->tp_net;
2691 				break;
2692 			default:
2693 				off = ph.h1->tp_net;
2694 				break;
2695 			}
2696 		} else {
2697 			switch (po->tp_version) {
2698 			case TPACKET_V3:
2699 				off = ph.h3->tp_mac;
2700 				break;
2701 			case TPACKET_V2:
2702 				off = ph.h2->tp_mac;
2703 				break;
2704 			default:
2705 				off = ph.h1->tp_mac;
2706 				break;
2707 			}
2708 		}
2709 		if (unlikely((off < off_min) || (off_max < off)))
2710 			return -EINVAL;
2711 	} else {
2712 		off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2713 	}
2714 
2715 	*data = frame + off;
2716 	return tp_len;
2717 }
2718 
2719 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2720 {
2721 	struct sk_buff *skb = NULL;
2722 	struct net_device *dev;
2723 	struct virtio_net_hdr *vnet_hdr = NULL;
2724 	struct sockcm_cookie sockc;
2725 	__be16 proto;
2726 	int err, reserve = 0;
2727 	void *ph;
2728 	DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2729 	bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2730 	int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
2731 	unsigned char *addr = NULL;
2732 	int tp_len, size_max;
2733 	void *data;
2734 	int len_sum = 0;
2735 	int status = TP_STATUS_AVAILABLE;
2736 	int hlen, tlen, copylen = 0;
2737 	long timeo = 0;
2738 
2739 	mutex_lock(&po->pg_vec_lock);
2740 
2741 	/* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2742 	 * we need to confirm it under protection of pg_vec_lock.
2743 	 */
2744 	if (unlikely(!po->tx_ring.pg_vec)) {
2745 		err = -EBUSY;
2746 		goto out;
2747 	}
2748 	if (likely(saddr == NULL)) {
2749 		dev	= packet_cached_dev_get(po);
2750 		proto	= READ_ONCE(po->num);
2751 	} else {
2752 		err = -EINVAL;
2753 		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2754 			goto out;
2755 		if (msg->msg_namelen < (saddr->sll_halen
2756 					+ offsetof(struct sockaddr_ll,
2757 						sll_addr)))
2758 			goto out;
2759 		proto	= saddr->sll_protocol;
2760 		dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2761 		if (po->sk.sk_socket->type == SOCK_DGRAM) {
2762 			if (dev && msg->msg_namelen < dev->addr_len +
2763 				   offsetof(struct sockaddr_ll, sll_addr))
2764 				goto out_put;
2765 			addr = saddr->sll_addr;
2766 		}
2767 	}
2768 
2769 	err = -ENXIO;
2770 	if (unlikely(dev == NULL))
2771 		goto out;
2772 	err = -ENETDOWN;
2773 	if (unlikely(!(dev->flags & IFF_UP)))
2774 		goto out_put;
2775 
2776 	sockcm_init(&sockc, &po->sk);
2777 	if (msg->msg_controllen) {
2778 		err = sock_cmsg_send(&po->sk, msg, &sockc);
2779 		if (unlikely(err))
2780 			goto out_put;
2781 	}
2782 
2783 	if (po->sk.sk_socket->type == SOCK_RAW)
2784 		reserve = dev->hard_header_len;
2785 	size_max = po->tx_ring.frame_size
2786 		- (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2787 
2788 	if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz)
2789 		size_max = dev->mtu + reserve + VLAN_HLEN;
2790 
2791 	reinit_completion(&po->skb_completion);
2792 
2793 	do {
2794 		ph = packet_current_frame(po, &po->tx_ring,
2795 					  TP_STATUS_SEND_REQUEST);
2796 		if (unlikely(ph == NULL)) {
2797 			if (need_wait && skb) {
2798 				timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2799 				timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2800 				if (timeo <= 0) {
2801 					err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2802 					goto out_put;
2803 				}
2804 			}
2805 			/* check for additional frames */
2806 			continue;
2807 		}
2808 
2809 		skb = NULL;
2810 		tp_len = tpacket_parse_header(po, ph, size_max, &data);
2811 		if (tp_len < 0)
2812 			goto tpacket_error;
2813 
2814 		status = TP_STATUS_SEND_REQUEST;
2815 		hlen = LL_RESERVED_SPACE(dev);
2816 		tlen = dev->needed_tailroom;
2817 		if (vnet_hdr_sz) {
2818 			vnet_hdr = data;
2819 			data += vnet_hdr_sz;
2820 			tp_len -= vnet_hdr_sz;
2821 			if (tp_len < 0 ||
2822 			    __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2823 				tp_len = -EINVAL;
2824 				goto tpacket_error;
2825 			}
2826 			copylen = __virtio16_to_cpu(vio_le(),
2827 						    vnet_hdr->hdr_len);
2828 		}
2829 		copylen = max_t(int, copylen, dev->hard_header_len);
2830 		skb = sock_alloc_send_skb(&po->sk,
2831 				hlen + tlen + sizeof(struct sockaddr_ll) +
2832 				(copylen - dev->hard_header_len),
2833 				!need_wait, &err);
2834 
2835 		if (unlikely(skb == NULL)) {
2836 			/* we assume the socket was initially writeable ... */
2837 			if (likely(len_sum > 0))
2838 				err = len_sum;
2839 			goto out_status;
2840 		}
2841 		tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2842 					  addr, hlen, copylen, &sockc);
2843 		if (likely(tp_len >= 0) &&
2844 		    tp_len > dev->mtu + reserve &&
2845 		    !vnet_hdr_sz &&
2846 		    !packet_extra_vlan_len_allowed(dev, skb))
2847 			tp_len = -EMSGSIZE;
2848 
2849 		if (unlikely(tp_len < 0)) {
2850 tpacket_error:
2851 			if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) {
2852 				__packet_set_status(po, ph,
2853 						TP_STATUS_AVAILABLE);
2854 				packet_increment_head(&po->tx_ring);
2855 				kfree_skb(skb);
2856 				continue;
2857 			} else {
2858 				status = TP_STATUS_WRONG_FORMAT;
2859 				err = tp_len;
2860 				goto out_status;
2861 			}
2862 		}
2863 
2864 		if (vnet_hdr_sz) {
2865 			if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2866 				tp_len = -EINVAL;
2867 				goto tpacket_error;
2868 			}
2869 			virtio_net_hdr_set_proto(skb, vnet_hdr);
2870 		}
2871 
2872 		skb->destructor = tpacket_destruct_skb;
2873 		__packet_set_status(po, ph, TP_STATUS_SENDING);
2874 		packet_inc_pending(&po->tx_ring);
2875 
2876 		status = TP_STATUS_SEND_REQUEST;
2877 		err = packet_xmit(po, skb);
2878 		if (unlikely(err != 0)) {
2879 			if (err > 0)
2880 				err = net_xmit_errno(err);
2881 			if (err && __packet_get_status(po, ph) ==
2882 				   TP_STATUS_AVAILABLE) {
2883 				/* skb was destructed already */
2884 				skb = NULL;
2885 				goto out_status;
2886 			}
2887 			/*
2888 			 * skb was dropped but not destructed yet;
2889 			 * let's treat it like congestion or err < 0
2890 			 */
2891 			err = 0;
2892 		}
2893 		packet_increment_head(&po->tx_ring);
2894 		len_sum += tp_len;
2895 	} while (likely((ph != NULL) ||
2896 		/* Note: packet_read_pending() might be slow if we have
2897 		 * to call it as it's per_cpu variable, but in fast-path
2898 		 * we already short-circuit the loop with the first
2899 		 * condition, and luckily don't have to go that path
2900 		 * anyway.
2901 		 */
2902 		 (need_wait && packet_read_pending(&po->tx_ring))));
2903 
2904 	err = len_sum;
2905 	goto out_put;
2906 
2907 out_status:
2908 	__packet_set_status(po, ph, status);
2909 	kfree_skb(skb);
2910 out_put:
2911 	dev_put(dev);
2912 out:
2913 	mutex_unlock(&po->pg_vec_lock);
2914 	return err;
2915 }
2916 
2917 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2918 				        size_t reserve, size_t len,
2919 				        size_t linear, int noblock,
2920 				        int *err)
2921 {
2922 	struct sk_buff *skb;
2923 
2924 	/* Under a page?  Don't bother with paged skb. */
2925 	if (prepad + len < PAGE_SIZE || !linear)
2926 		linear = len;
2927 
2928 	if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER))
2929 		linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER);
2930 	skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2931 				   err, PAGE_ALLOC_COSTLY_ORDER);
2932 	if (!skb)
2933 		return NULL;
2934 
2935 	skb_reserve(skb, reserve);
2936 	skb_put(skb, linear);
2937 	skb->data_len = len - linear;
2938 	skb->len += len - linear;
2939 
2940 	return skb;
2941 }
2942 
2943 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2944 {
2945 	struct sock *sk = sock->sk;
2946 	DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2947 	struct sk_buff *skb;
2948 	struct net_device *dev;
2949 	__be16 proto;
2950 	unsigned char *addr = NULL;
2951 	int err, reserve = 0;
2952 	struct sockcm_cookie sockc;
2953 	struct virtio_net_hdr vnet_hdr = { 0 };
2954 	int offset = 0;
2955 	struct packet_sock *po = pkt_sk(sk);
2956 	int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz);
2957 	int hlen, tlen, linear;
2958 	int extra_len = 0;
2959 
2960 	/*
2961 	 *	Get and verify the address.
2962 	 */
2963 
2964 	if (likely(saddr == NULL)) {
2965 		dev	= packet_cached_dev_get(po);
2966 		proto	= READ_ONCE(po->num);
2967 	} else {
2968 		err = -EINVAL;
2969 		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2970 			goto out;
2971 		if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2972 			goto out;
2973 		proto	= saddr->sll_protocol;
2974 		dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2975 		if (sock->type == SOCK_DGRAM) {
2976 			if (dev && msg->msg_namelen < dev->addr_len +
2977 				   offsetof(struct sockaddr_ll, sll_addr))
2978 				goto out_unlock;
2979 			addr = saddr->sll_addr;
2980 		}
2981 	}
2982 
2983 	err = -ENXIO;
2984 	if (unlikely(dev == NULL))
2985 		goto out_unlock;
2986 	err = -ENETDOWN;
2987 	if (unlikely(!(dev->flags & IFF_UP)))
2988 		goto out_unlock;
2989 
2990 	sockcm_init(&sockc, sk);
2991 	sockc.mark = READ_ONCE(sk->sk_mark);
2992 	if (msg->msg_controllen) {
2993 		err = sock_cmsg_send(sk, msg, &sockc);
2994 		if (unlikely(err))
2995 			goto out_unlock;
2996 	}
2997 
2998 	if (sock->type == SOCK_RAW)
2999 		reserve = dev->hard_header_len;
3000 	if (vnet_hdr_sz) {
3001 		err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz);
3002 		if (err)
3003 			goto out_unlock;
3004 	}
3005 
3006 	if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
3007 		if (!netif_supports_nofcs(dev)) {
3008 			err = -EPROTONOSUPPORT;
3009 			goto out_unlock;
3010 		}
3011 		extra_len = 4; /* We're doing our own CRC */
3012 	}
3013 
3014 	err = -EMSGSIZE;
3015 	if (!vnet_hdr.gso_type &&
3016 	    (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
3017 		goto out_unlock;
3018 
3019 	err = -ENOBUFS;
3020 	hlen = LL_RESERVED_SPACE(dev);
3021 	tlen = dev->needed_tailroom;
3022 	linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
3023 	linear = max(linear, min_t(int, len, dev->hard_header_len));
3024 	skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
3025 			       msg->msg_flags & MSG_DONTWAIT, &err);
3026 	if (skb == NULL)
3027 		goto out_unlock;
3028 
3029 	skb_reset_network_header(skb);
3030 
3031 	err = -EINVAL;
3032 	if (sock->type == SOCK_DGRAM) {
3033 		offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
3034 		if (unlikely(offset < 0))
3035 			goto out_free;
3036 	} else if (reserve) {
3037 		skb_reserve(skb, -reserve);
3038 		if (len < reserve + sizeof(struct ipv6hdr) &&
3039 		    dev->min_header_len != dev->hard_header_len)
3040 			skb_reset_network_header(skb);
3041 	}
3042 
3043 	/* Returns -EFAULT on error */
3044 	err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
3045 	if (err)
3046 		goto out_free;
3047 
3048 	if ((sock->type == SOCK_RAW &&
3049 	     !dev_validate_header(dev, skb->data, len)) || !skb->len) {
3050 		err = -EINVAL;
3051 		goto out_free;
3052 	}
3053 
3054 	skb_setup_tx_timestamp(skb, sockc.tsflags);
3055 
3056 	if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
3057 	    !packet_extra_vlan_len_allowed(dev, skb)) {
3058 		err = -EMSGSIZE;
3059 		goto out_free;
3060 	}
3061 
3062 	skb->protocol = proto;
3063 	skb->dev = dev;
3064 	skb->priority = READ_ONCE(sk->sk_priority);
3065 	skb->mark = sockc.mark;
3066 	skb->tstamp = sockc.transmit_time;
3067 
3068 	if (unlikely(extra_len == 4))
3069 		skb->no_fcs = 1;
3070 
3071 	packet_parse_headers(skb, sock);
3072 
3073 	if (vnet_hdr_sz) {
3074 		err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
3075 		if (err)
3076 			goto out_free;
3077 		len += vnet_hdr_sz;
3078 		virtio_net_hdr_set_proto(skb, &vnet_hdr);
3079 	}
3080 
3081 	err = packet_xmit(po, skb);
3082 
3083 	if (unlikely(err != 0)) {
3084 		if (err > 0)
3085 			err = net_xmit_errno(err);
3086 		if (err)
3087 			goto out_unlock;
3088 	}
3089 
3090 	dev_put(dev);
3091 
3092 	return len;
3093 
3094 out_free:
3095 	kfree_skb(skb);
3096 out_unlock:
3097 	dev_put(dev);
3098 out:
3099 	return err;
3100 }
3101 
3102 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
3103 {
3104 	struct sock *sk = sock->sk;
3105 	struct packet_sock *po = pkt_sk(sk);
3106 
3107 	/* Reading tx_ring.pg_vec without holding pg_vec_lock is racy.
3108 	 * tpacket_snd() will redo the check safely.
3109 	 */
3110 	if (data_race(po->tx_ring.pg_vec))
3111 		return tpacket_snd(po, msg);
3112 
3113 	return packet_snd(sock, msg, len);
3114 }
3115 
3116 /*
3117  *	Close a PACKET socket. This is fairly simple. We immediately go
3118  *	to 'closed' state and remove our protocol entry in the device list.
3119  */
3120 
3121 static int packet_release(struct socket *sock)
3122 {
3123 	struct sock *sk = sock->sk;
3124 	struct packet_sock *po;
3125 	struct packet_fanout *f;
3126 	struct net *net;
3127 	union tpacket_req_u req_u;
3128 
3129 	if (!sk)
3130 		return 0;
3131 
3132 	net = sock_net(sk);
3133 	po = pkt_sk(sk);
3134 
3135 	mutex_lock(&net->packet.sklist_lock);
3136 	sk_del_node_init_rcu(sk);
3137 	mutex_unlock(&net->packet.sklist_lock);
3138 
3139 	sock_prot_inuse_add(net, sk->sk_prot, -1);
3140 
3141 	spin_lock(&po->bind_lock);
3142 	unregister_prot_hook(sk, false);
3143 	packet_cached_dev_reset(po);
3144 
3145 	if (po->prot_hook.dev) {
3146 		netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker);
3147 		po->prot_hook.dev = NULL;
3148 	}
3149 	spin_unlock(&po->bind_lock);
3150 
3151 	packet_flush_mclist(sk);
3152 
3153 	lock_sock(sk);
3154 	if (po->rx_ring.pg_vec) {
3155 		memset(&req_u, 0, sizeof(req_u));
3156 		packet_set_ring(sk, &req_u, 1, 0);
3157 	}
3158 
3159 	if (po->tx_ring.pg_vec) {
3160 		memset(&req_u, 0, sizeof(req_u));
3161 		packet_set_ring(sk, &req_u, 1, 1);
3162 	}
3163 	release_sock(sk);
3164 
3165 	f = fanout_release(sk);
3166 
3167 	synchronize_net();
3168 
3169 	kfree(po->rollover);
3170 	if (f) {
3171 		fanout_release_data(f);
3172 		kvfree(f);
3173 	}
3174 	/*
3175 	 *	Now the socket is dead. No more input will appear.
3176 	 */
3177 	sock_orphan(sk);
3178 	sock->sk = NULL;
3179 
3180 	/* Purge queues */
3181 
3182 	skb_queue_purge(&sk->sk_receive_queue);
3183 	packet_free_pending(po);
3184 
3185 	sock_put(sk);
3186 	return 0;
3187 }
3188 
3189 /*
3190  *	Attach a packet hook.
3191  */
3192 
3193 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3194 			  __be16 proto)
3195 {
3196 	struct packet_sock *po = pkt_sk(sk);
3197 	struct net_device *dev = NULL;
3198 	bool unlisted = false;
3199 	bool need_rehook;
3200 	int ret = 0;
3201 
3202 	lock_sock(sk);
3203 	spin_lock(&po->bind_lock);
3204 	if (!proto)
3205 		proto = po->num;
3206 
3207 	rcu_read_lock();
3208 
3209 	if (po->fanout) {
3210 		ret = -EINVAL;
3211 		goto out_unlock;
3212 	}
3213 
3214 	if (name) {
3215 		dev = dev_get_by_name_rcu(sock_net(sk), name);
3216 		if (!dev) {
3217 			ret = -ENODEV;
3218 			goto out_unlock;
3219 		}
3220 	} else if (ifindex) {
3221 		dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3222 		if (!dev) {
3223 			ret = -ENODEV;
3224 			goto out_unlock;
3225 		}
3226 	}
3227 
3228 	need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev;
3229 
3230 	if (need_rehook) {
3231 		dev_hold(dev);
3232 		if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
3233 			rcu_read_unlock();
3234 			/* prevents packet_notifier() from calling
3235 			 * register_prot_hook()
3236 			 */
3237 			WRITE_ONCE(po->num, 0);
3238 			__unregister_prot_hook(sk, true);
3239 			rcu_read_lock();
3240 			if (dev)
3241 				unlisted = !dev_get_by_index_rcu(sock_net(sk),
3242 								 dev->ifindex);
3243 		}
3244 
3245 		BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING));
3246 		WRITE_ONCE(po->num, proto);
3247 		po->prot_hook.type = proto;
3248 
3249 		netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker);
3250 
3251 		if (unlikely(unlisted)) {
3252 			po->prot_hook.dev = NULL;
3253 			WRITE_ONCE(po->ifindex, -1);
3254 			packet_cached_dev_reset(po);
3255 		} else {
3256 			netdev_hold(dev, &po->prot_hook.dev_tracker,
3257 				    GFP_ATOMIC);
3258 			po->prot_hook.dev = dev;
3259 			WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0);
3260 			packet_cached_dev_assign(po, dev);
3261 		}
3262 		dev_put(dev);
3263 	}
3264 
3265 	if (proto == 0 || !need_rehook)
3266 		goto out_unlock;
3267 
3268 	if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3269 		register_prot_hook(sk);
3270 	} else {
3271 		sk->sk_err = ENETDOWN;
3272 		if (!sock_flag(sk, SOCK_DEAD))
3273 			sk_error_report(sk);
3274 	}
3275 
3276 out_unlock:
3277 	rcu_read_unlock();
3278 	spin_unlock(&po->bind_lock);
3279 	release_sock(sk);
3280 	return ret;
3281 }
3282 
3283 /*
3284  *	Bind a packet socket to a device
3285  */
3286 
3287 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3288 			    int addr_len)
3289 {
3290 	struct sock *sk = sock->sk;
3291 	char name[sizeof(uaddr->sa_data_min) + 1];
3292 
3293 	/*
3294 	 *	Check legality
3295 	 */
3296 
3297 	if (addr_len != sizeof(struct sockaddr))
3298 		return -EINVAL;
3299 	/* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3300 	 * zero-terminated.
3301 	 */
3302 	memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min));
3303 	name[sizeof(uaddr->sa_data_min)] = 0;
3304 
3305 	return packet_do_bind(sk, name, 0, 0);
3306 }
3307 
3308 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3309 {
3310 	struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3311 	struct sock *sk = sock->sk;
3312 
3313 	/*
3314 	 *	Check legality
3315 	 */
3316 
3317 	if (addr_len < sizeof(struct sockaddr_ll))
3318 		return -EINVAL;
3319 	if (sll->sll_family != AF_PACKET)
3320 		return -EINVAL;
3321 
3322 	return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol);
3323 }
3324 
3325 static struct proto packet_proto = {
3326 	.name	  = "PACKET",
3327 	.owner	  = THIS_MODULE,
3328 	.obj_size = sizeof(struct packet_sock),
3329 };
3330 
3331 /*
3332  *	Create a packet of type SOCK_PACKET.
3333  */
3334 
3335 static int packet_create(struct net *net, struct socket *sock, int protocol,
3336 			 int kern)
3337 {
3338 	struct sock *sk;
3339 	struct packet_sock *po;
3340 	__be16 proto = (__force __be16)protocol; /* weird, but documented */
3341 	int err;
3342 
3343 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
3344 		return -EPERM;
3345 	if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3346 	    sock->type != SOCK_PACKET)
3347 		return -ESOCKTNOSUPPORT;
3348 
3349 	sock->state = SS_UNCONNECTED;
3350 
3351 	err = -ENOBUFS;
3352 	sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3353 	if (sk == NULL)
3354 		goto out;
3355 
3356 	sock->ops = &packet_ops;
3357 	if (sock->type == SOCK_PACKET)
3358 		sock->ops = &packet_ops_spkt;
3359 
3360 	sock_init_data(sock, sk);
3361 
3362 	po = pkt_sk(sk);
3363 	init_completion(&po->skb_completion);
3364 	sk->sk_family = PF_PACKET;
3365 	po->num = proto;
3366 
3367 	err = packet_alloc_pending(po);
3368 	if (err)
3369 		goto out2;
3370 
3371 	packet_cached_dev_reset(po);
3372 
3373 	sk->sk_destruct = packet_sock_destruct;
3374 
3375 	/*
3376 	 *	Attach a protocol block
3377 	 */
3378 
3379 	spin_lock_init(&po->bind_lock);
3380 	mutex_init(&po->pg_vec_lock);
3381 	po->rollover = NULL;
3382 	po->prot_hook.func = packet_rcv;
3383 
3384 	if (sock->type == SOCK_PACKET)
3385 		po->prot_hook.func = packet_rcv_spkt;
3386 
3387 	po->prot_hook.af_packet_priv = sk;
3388 	po->prot_hook.af_packet_net = sock_net(sk);
3389 
3390 	if (proto) {
3391 		po->prot_hook.type = proto;
3392 		__register_prot_hook(sk);
3393 	}
3394 
3395 	mutex_lock(&net->packet.sklist_lock);
3396 	sk_add_node_tail_rcu(sk, &net->packet.sklist);
3397 	mutex_unlock(&net->packet.sklist_lock);
3398 
3399 	sock_prot_inuse_add(net, &packet_proto, 1);
3400 
3401 	return 0;
3402 out2:
3403 	sk_free(sk);
3404 out:
3405 	return err;
3406 }
3407 
3408 /*
3409  *	Pull a packet from our receive queue and hand it to the user.
3410  *	If necessary we block.
3411  */
3412 
3413 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3414 			  int flags)
3415 {
3416 	struct sock *sk = sock->sk;
3417 	struct sk_buff *skb;
3418 	int copied, err;
3419 	int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz);
3420 	unsigned int origlen = 0;
3421 
3422 	err = -EINVAL;
3423 	if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3424 		goto out;
3425 
3426 #if 0
3427 	/* What error should we return now? EUNATTACH? */
3428 	if (pkt_sk(sk)->ifindex < 0)
3429 		return -ENODEV;
3430 #endif
3431 
3432 	if (flags & MSG_ERRQUEUE) {
3433 		err = sock_recv_errqueue(sk, msg, len,
3434 					 SOL_PACKET, PACKET_TX_TIMESTAMP);
3435 		goto out;
3436 	}
3437 
3438 	/*
3439 	 *	Call the generic datagram receiver. This handles all sorts
3440 	 *	of horrible races and re-entrancy so we can forget about it
3441 	 *	in the protocol layers.
3442 	 *
3443 	 *	Now it will return ENETDOWN, if device have just gone down,
3444 	 *	but then it will block.
3445 	 */
3446 
3447 	skb = skb_recv_datagram(sk, flags, &err);
3448 
3449 	/*
3450 	 *	An error occurred so return it. Because skb_recv_datagram()
3451 	 *	handles the blocking we don't see and worry about blocking
3452 	 *	retries.
3453 	 */
3454 
3455 	if (skb == NULL)
3456 		goto out;
3457 
3458 	packet_rcv_try_clear_pressure(pkt_sk(sk));
3459 
3460 	if (vnet_hdr_len) {
3461 		err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len);
3462 		if (err)
3463 			goto out_free;
3464 	}
3465 
3466 	/* You lose any data beyond the buffer you gave. If it worries
3467 	 * a user program they can ask the device for its MTU
3468 	 * anyway.
3469 	 */
3470 	copied = skb->len;
3471 	if (copied > len) {
3472 		copied = len;
3473 		msg->msg_flags |= MSG_TRUNC;
3474 	}
3475 
3476 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3477 	if (err)
3478 		goto out_free;
3479 
3480 	if (sock->type != SOCK_PACKET) {
3481 		struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3482 
3483 		/* Original length was stored in sockaddr_ll fields */
3484 		origlen = PACKET_SKB_CB(skb)->sa.origlen;
3485 		sll->sll_family = AF_PACKET;
3486 		sll->sll_protocol = skb->protocol;
3487 	}
3488 
3489 	sock_recv_cmsgs(msg, sk, skb);
3490 
3491 	if (msg->msg_name) {
3492 		const size_t max_len = min(sizeof(skb->cb),
3493 					   sizeof(struct sockaddr_storage));
3494 		int copy_len;
3495 
3496 		/* If the address length field is there to be filled
3497 		 * in, we fill it in now.
3498 		 */
3499 		if (sock->type == SOCK_PACKET) {
3500 			__sockaddr_check_size(sizeof(struct sockaddr_pkt));
3501 			msg->msg_namelen = sizeof(struct sockaddr_pkt);
3502 			copy_len = msg->msg_namelen;
3503 		} else {
3504 			struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3505 
3506 			msg->msg_namelen = sll->sll_halen +
3507 				offsetof(struct sockaddr_ll, sll_addr);
3508 			copy_len = msg->msg_namelen;
3509 			if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3510 				memset(msg->msg_name +
3511 				       offsetof(struct sockaddr_ll, sll_addr),
3512 				       0, sizeof(sll->sll_addr));
3513 				msg->msg_namelen = sizeof(struct sockaddr_ll);
3514 			}
3515 		}
3516 		if (WARN_ON_ONCE(copy_len > max_len)) {
3517 			copy_len = max_len;
3518 			msg->msg_namelen = copy_len;
3519 		}
3520 		memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3521 	}
3522 
3523 	if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) {
3524 		struct tpacket_auxdata aux;
3525 
3526 		aux.tp_status = TP_STATUS_USER;
3527 		if (skb->ip_summed == CHECKSUM_PARTIAL)
3528 			aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3529 		else if (skb->pkt_type != PACKET_OUTGOING &&
3530 			 skb_csum_unnecessary(skb))
3531 			aux.tp_status |= TP_STATUS_CSUM_VALID;
3532 		if (skb_is_gso(skb) && skb_is_gso_tcp(skb))
3533 			aux.tp_status |= TP_STATUS_GSO_TCP;
3534 
3535 		aux.tp_len = origlen;
3536 		aux.tp_snaplen = skb->len;
3537 		aux.tp_mac = 0;
3538 		aux.tp_net = skb_network_offset(skb);
3539 		if (skb_vlan_tag_present(skb)) {
3540 			aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3541 			aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3542 			aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3543 		} else {
3544 			aux.tp_vlan_tci = 0;
3545 			aux.tp_vlan_tpid = 0;
3546 		}
3547 		put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3548 	}
3549 
3550 	/*
3551 	 *	Free or return the buffer as appropriate. Again this
3552 	 *	hides all the races and re-entrancy issues from us.
3553 	 */
3554 	err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3555 
3556 out_free:
3557 	skb_free_datagram(sk, skb);
3558 out:
3559 	return err;
3560 }
3561 
3562 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3563 			       int peer)
3564 {
3565 	struct net_device *dev;
3566 	struct sock *sk	= sock->sk;
3567 
3568 	if (peer)
3569 		return -EOPNOTSUPP;
3570 
3571 	uaddr->sa_family = AF_PACKET;
3572 	memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data_min));
3573 	rcu_read_lock();
3574 	dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex));
3575 	if (dev)
3576 		strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data_min));
3577 	rcu_read_unlock();
3578 
3579 	return sizeof(*uaddr);
3580 }
3581 
3582 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3583 			  int peer)
3584 {
3585 	struct net_device *dev;
3586 	struct sock *sk = sock->sk;
3587 	struct packet_sock *po = pkt_sk(sk);
3588 	DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3589 	int ifindex;
3590 
3591 	if (peer)
3592 		return -EOPNOTSUPP;
3593 
3594 	ifindex = READ_ONCE(po->ifindex);
3595 	sll->sll_family = AF_PACKET;
3596 	sll->sll_ifindex = ifindex;
3597 	sll->sll_protocol = READ_ONCE(po->num);
3598 	sll->sll_pkttype = 0;
3599 	rcu_read_lock();
3600 	dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3601 	if (dev) {
3602 		sll->sll_hatype = dev->type;
3603 		sll->sll_halen = dev->addr_len;
3604 
3605 		/* Let __fortify_memcpy_chk() know the actual buffer size. */
3606 		memcpy(((struct sockaddr_storage *)sll)->__data +
3607 		       offsetof(struct sockaddr_ll, sll_addr) -
3608 		       offsetofend(struct sockaddr_ll, sll_family),
3609 		       dev->dev_addr, dev->addr_len);
3610 	} else {
3611 		sll->sll_hatype = 0;	/* Bad: we have no ARPHRD_UNSPEC */
3612 		sll->sll_halen = 0;
3613 	}
3614 	rcu_read_unlock();
3615 
3616 	return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3617 }
3618 
3619 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3620 			 int what)
3621 {
3622 	switch (i->type) {
3623 	case PACKET_MR_MULTICAST:
3624 		if (i->alen != dev->addr_len)
3625 			return -EINVAL;
3626 		if (what > 0)
3627 			return dev_mc_add(dev, i->addr);
3628 		else
3629 			return dev_mc_del(dev, i->addr);
3630 		break;
3631 	case PACKET_MR_PROMISC:
3632 		return dev_set_promiscuity(dev, what);
3633 	case PACKET_MR_ALLMULTI:
3634 		return dev_set_allmulti(dev, what);
3635 	case PACKET_MR_UNICAST:
3636 		if (i->alen != dev->addr_len)
3637 			return -EINVAL;
3638 		if (what > 0)
3639 			return dev_uc_add(dev, i->addr);
3640 		else
3641 			return dev_uc_del(dev, i->addr);
3642 		break;
3643 	default:
3644 		break;
3645 	}
3646 	return 0;
3647 }
3648 
3649 static void packet_dev_mclist_delete(struct net_device *dev,
3650 				     struct packet_mclist **mlp)
3651 {
3652 	struct packet_mclist *ml;
3653 
3654 	while ((ml = *mlp) != NULL) {
3655 		if (ml->ifindex == dev->ifindex) {
3656 			packet_dev_mc(dev, ml, -1);
3657 			*mlp = ml->next;
3658 			kfree(ml);
3659 		} else
3660 			mlp = &ml->next;
3661 	}
3662 }
3663 
3664 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3665 {
3666 	struct packet_sock *po = pkt_sk(sk);
3667 	struct packet_mclist *ml, *i;
3668 	struct net_device *dev;
3669 	int err;
3670 
3671 	rtnl_lock();
3672 
3673 	err = -ENODEV;
3674 	dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3675 	if (!dev)
3676 		goto done;
3677 
3678 	err = -EINVAL;
3679 	if (mreq->mr_alen > dev->addr_len)
3680 		goto done;
3681 
3682 	err = -ENOBUFS;
3683 	i = kmalloc(sizeof(*i), GFP_KERNEL);
3684 	if (i == NULL)
3685 		goto done;
3686 
3687 	err = 0;
3688 	for (ml = po->mclist; ml; ml = ml->next) {
3689 		if (ml->ifindex == mreq->mr_ifindex &&
3690 		    ml->type == mreq->mr_type &&
3691 		    ml->alen == mreq->mr_alen &&
3692 		    memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3693 			ml->count++;
3694 			/* Free the new element ... */
3695 			kfree(i);
3696 			goto done;
3697 		}
3698 	}
3699 
3700 	i->type = mreq->mr_type;
3701 	i->ifindex = mreq->mr_ifindex;
3702 	i->alen = mreq->mr_alen;
3703 	memcpy(i->addr, mreq->mr_address, i->alen);
3704 	memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3705 	i->count = 1;
3706 	i->next = po->mclist;
3707 	po->mclist = i;
3708 	err = packet_dev_mc(dev, i, 1);
3709 	if (err) {
3710 		po->mclist = i->next;
3711 		kfree(i);
3712 	}
3713 
3714 done:
3715 	rtnl_unlock();
3716 	return err;
3717 }
3718 
3719 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3720 {
3721 	struct packet_mclist *ml, **mlp;
3722 
3723 	rtnl_lock();
3724 
3725 	for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3726 		if (ml->ifindex == mreq->mr_ifindex &&
3727 		    ml->type == mreq->mr_type &&
3728 		    ml->alen == mreq->mr_alen &&
3729 		    memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3730 			if (--ml->count == 0) {
3731 				struct net_device *dev;
3732 				*mlp = ml->next;
3733 				dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3734 				if (dev)
3735 					packet_dev_mc(dev, ml, -1);
3736 				kfree(ml);
3737 			}
3738 			break;
3739 		}
3740 	}
3741 	rtnl_unlock();
3742 	return 0;
3743 }
3744 
3745 static void packet_flush_mclist(struct sock *sk)
3746 {
3747 	struct packet_sock *po = pkt_sk(sk);
3748 	struct packet_mclist *ml;
3749 
3750 	if (!po->mclist)
3751 		return;
3752 
3753 	rtnl_lock();
3754 	while ((ml = po->mclist) != NULL) {
3755 		struct net_device *dev;
3756 
3757 		po->mclist = ml->next;
3758 		dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3759 		if (dev != NULL)
3760 			packet_dev_mc(dev, ml, -1);
3761 		kfree(ml);
3762 	}
3763 	rtnl_unlock();
3764 }
3765 
3766 static int
3767 packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
3768 		  unsigned int optlen)
3769 {
3770 	struct sock *sk = sock->sk;
3771 	struct packet_sock *po = pkt_sk(sk);
3772 	int ret;
3773 
3774 	if (level != SOL_PACKET)
3775 		return -ENOPROTOOPT;
3776 
3777 	switch (optname) {
3778 	case PACKET_ADD_MEMBERSHIP:
3779 	case PACKET_DROP_MEMBERSHIP:
3780 	{
3781 		struct packet_mreq_max mreq;
3782 		int len = optlen;
3783 		memset(&mreq, 0, sizeof(mreq));
3784 		if (len < sizeof(struct packet_mreq))
3785 			return -EINVAL;
3786 		if (len > sizeof(mreq))
3787 			len = sizeof(mreq);
3788 		if (copy_from_sockptr(&mreq, optval, len))
3789 			return -EFAULT;
3790 		if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3791 			return -EINVAL;
3792 		if (optname == PACKET_ADD_MEMBERSHIP)
3793 			ret = packet_mc_add(sk, &mreq);
3794 		else
3795 			ret = packet_mc_drop(sk, &mreq);
3796 		return ret;
3797 	}
3798 
3799 	case PACKET_RX_RING:
3800 	case PACKET_TX_RING:
3801 	{
3802 		union tpacket_req_u req_u;
3803 		int len;
3804 
3805 		lock_sock(sk);
3806 		switch (po->tp_version) {
3807 		case TPACKET_V1:
3808 		case TPACKET_V2:
3809 			len = sizeof(req_u.req);
3810 			break;
3811 		case TPACKET_V3:
3812 		default:
3813 			len = sizeof(req_u.req3);
3814 			break;
3815 		}
3816 		if (optlen < len) {
3817 			ret = -EINVAL;
3818 		} else {
3819 			if (copy_from_sockptr(&req_u.req, optval, len))
3820 				ret = -EFAULT;
3821 			else
3822 				ret = packet_set_ring(sk, &req_u, 0,
3823 						    optname == PACKET_TX_RING);
3824 		}
3825 		release_sock(sk);
3826 		return ret;
3827 	}
3828 	case PACKET_COPY_THRESH:
3829 	{
3830 		int val;
3831 
3832 		if (optlen != sizeof(val))
3833 			return -EINVAL;
3834 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3835 			return -EFAULT;
3836 
3837 		pkt_sk(sk)->copy_thresh = val;
3838 		return 0;
3839 	}
3840 	case PACKET_VERSION:
3841 	{
3842 		int val;
3843 
3844 		if (optlen != sizeof(val))
3845 			return -EINVAL;
3846 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3847 			return -EFAULT;
3848 		switch (val) {
3849 		case TPACKET_V1:
3850 		case TPACKET_V2:
3851 		case TPACKET_V3:
3852 			break;
3853 		default:
3854 			return -EINVAL;
3855 		}
3856 		lock_sock(sk);
3857 		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3858 			ret = -EBUSY;
3859 		} else {
3860 			po->tp_version = val;
3861 			ret = 0;
3862 		}
3863 		release_sock(sk);
3864 		return ret;
3865 	}
3866 	case PACKET_RESERVE:
3867 	{
3868 		unsigned int val;
3869 
3870 		if (optlen != sizeof(val))
3871 			return -EINVAL;
3872 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3873 			return -EFAULT;
3874 		if (val > INT_MAX)
3875 			return -EINVAL;
3876 		lock_sock(sk);
3877 		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3878 			ret = -EBUSY;
3879 		} else {
3880 			po->tp_reserve = val;
3881 			ret = 0;
3882 		}
3883 		release_sock(sk);
3884 		return ret;
3885 	}
3886 	case PACKET_LOSS:
3887 	{
3888 		unsigned int val;
3889 
3890 		if (optlen != sizeof(val))
3891 			return -EINVAL;
3892 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3893 			return -EFAULT;
3894 
3895 		lock_sock(sk);
3896 		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3897 			ret = -EBUSY;
3898 		} else {
3899 			packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val);
3900 			ret = 0;
3901 		}
3902 		release_sock(sk);
3903 		return ret;
3904 	}
3905 	case PACKET_AUXDATA:
3906 	{
3907 		int val;
3908 
3909 		if (optlen < sizeof(val))
3910 			return -EINVAL;
3911 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3912 			return -EFAULT;
3913 
3914 		packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val);
3915 		return 0;
3916 	}
3917 	case PACKET_ORIGDEV:
3918 	{
3919 		int val;
3920 
3921 		if (optlen < sizeof(val))
3922 			return -EINVAL;
3923 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3924 			return -EFAULT;
3925 
3926 		packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val);
3927 		return 0;
3928 	}
3929 	case PACKET_VNET_HDR:
3930 	case PACKET_VNET_HDR_SZ:
3931 	{
3932 		int val, hdr_len;
3933 
3934 		if (sock->type != SOCK_RAW)
3935 			return -EINVAL;
3936 		if (optlen < sizeof(val))
3937 			return -EINVAL;
3938 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3939 			return -EFAULT;
3940 
3941 		if (optname == PACKET_VNET_HDR_SZ) {
3942 			if (val && val != sizeof(struct virtio_net_hdr) &&
3943 			    val != sizeof(struct virtio_net_hdr_mrg_rxbuf))
3944 				return -EINVAL;
3945 			hdr_len = val;
3946 		} else {
3947 			hdr_len = val ? sizeof(struct virtio_net_hdr) : 0;
3948 		}
3949 		lock_sock(sk);
3950 		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3951 			ret = -EBUSY;
3952 		} else {
3953 			WRITE_ONCE(po->vnet_hdr_sz, hdr_len);
3954 			ret = 0;
3955 		}
3956 		release_sock(sk);
3957 		return ret;
3958 	}
3959 	case PACKET_TIMESTAMP:
3960 	{
3961 		int val;
3962 
3963 		if (optlen != sizeof(val))
3964 			return -EINVAL;
3965 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3966 			return -EFAULT;
3967 
3968 		WRITE_ONCE(po->tp_tstamp, val);
3969 		return 0;
3970 	}
3971 	case PACKET_FANOUT:
3972 	{
3973 		struct fanout_args args = { 0 };
3974 
3975 		if (optlen != sizeof(int) && optlen != sizeof(args))
3976 			return -EINVAL;
3977 		if (copy_from_sockptr(&args, optval, optlen))
3978 			return -EFAULT;
3979 
3980 		return fanout_add(sk, &args);
3981 	}
3982 	case PACKET_FANOUT_DATA:
3983 	{
3984 		/* Paired with the WRITE_ONCE() in fanout_add() */
3985 		if (!READ_ONCE(po->fanout))
3986 			return -EINVAL;
3987 
3988 		return fanout_set_data(po, optval, optlen);
3989 	}
3990 	case PACKET_IGNORE_OUTGOING:
3991 	{
3992 		int val;
3993 
3994 		if (optlen != sizeof(val))
3995 			return -EINVAL;
3996 		if (copy_from_sockptr(&val, optval, sizeof(val)))
3997 			return -EFAULT;
3998 		if (val < 0 || val > 1)
3999 			return -EINVAL;
4000 
4001 		po->prot_hook.ignore_outgoing = !!val;
4002 		return 0;
4003 	}
4004 	case PACKET_TX_HAS_OFF:
4005 	{
4006 		unsigned int val;
4007 
4008 		if (optlen != sizeof(val))
4009 			return -EINVAL;
4010 		if (copy_from_sockptr(&val, optval, sizeof(val)))
4011 			return -EFAULT;
4012 
4013 		lock_sock(sk);
4014 		if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec)
4015 			packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val);
4016 
4017 		release_sock(sk);
4018 		return 0;
4019 	}
4020 	case PACKET_QDISC_BYPASS:
4021 	{
4022 		int val;
4023 
4024 		if (optlen != sizeof(val))
4025 			return -EINVAL;
4026 		if (copy_from_sockptr(&val, optval, sizeof(val)))
4027 			return -EFAULT;
4028 
4029 		packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val);
4030 		return 0;
4031 	}
4032 	default:
4033 		return -ENOPROTOOPT;
4034 	}
4035 }
4036 
4037 static int packet_getsockopt(struct socket *sock, int level, int optname,
4038 			     char __user *optval, int __user *optlen)
4039 {
4040 	int len;
4041 	int val, lv = sizeof(val);
4042 	struct sock *sk = sock->sk;
4043 	struct packet_sock *po = pkt_sk(sk);
4044 	void *data = &val;
4045 	union tpacket_stats_u st;
4046 	struct tpacket_rollover_stats rstats;
4047 	int drops;
4048 
4049 	if (level != SOL_PACKET)
4050 		return -ENOPROTOOPT;
4051 
4052 	if (get_user(len, optlen))
4053 		return -EFAULT;
4054 
4055 	if (len < 0)
4056 		return -EINVAL;
4057 
4058 	switch (optname) {
4059 	case PACKET_STATISTICS:
4060 		spin_lock_bh(&sk->sk_receive_queue.lock);
4061 		memcpy(&st, &po->stats, sizeof(st));
4062 		memset(&po->stats, 0, sizeof(po->stats));
4063 		spin_unlock_bh(&sk->sk_receive_queue.lock);
4064 		drops = atomic_xchg(&po->tp_drops, 0);
4065 
4066 		if (po->tp_version == TPACKET_V3) {
4067 			lv = sizeof(struct tpacket_stats_v3);
4068 			st.stats3.tp_drops = drops;
4069 			st.stats3.tp_packets += drops;
4070 			data = &st.stats3;
4071 		} else {
4072 			lv = sizeof(struct tpacket_stats);
4073 			st.stats1.tp_drops = drops;
4074 			st.stats1.tp_packets += drops;
4075 			data = &st.stats1;
4076 		}
4077 
4078 		break;
4079 	case PACKET_AUXDATA:
4080 		val = packet_sock_flag(po, PACKET_SOCK_AUXDATA);
4081 		break;
4082 	case PACKET_ORIGDEV:
4083 		val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV);
4084 		break;
4085 	case PACKET_VNET_HDR:
4086 		val = !!READ_ONCE(po->vnet_hdr_sz);
4087 		break;
4088 	case PACKET_VNET_HDR_SZ:
4089 		val = READ_ONCE(po->vnet_hdr_sz);
4090 		break;
4091 	case PACKET_VERSION:
4092 		val = po->tp_version;
4093 		break;
4094 	case PACKET_HDRLEN:
4095 		if (len > sizeof(int))
4096 			len = sizeof(int);
4097 		if (len < sizeof(int))
4098 			return -EINVAL;
4099 		if (copy_from_user(&val, optval, len))
4100 			return -EFAULT;
4101 		switch (val) {
4102 		case TPACKET_V1:
4103 			val = sizeof(struct tpacket_hdr);
4104 			break;
4105 		case TPACKET_V2:
4106 			val = sizeof(struct tpacket2_hdr);
4107 			break;
4108 		case TPACKET_V3:
4109 			val = sizeof(struct tpacket3_hdr);
4110 			break;
4111 		default:
4112 			return -EINVAL;
4113 		}
4114 		break;
4115 	case PACKET_RESERVE:
4116 		val = po->tp_reserve;
4117 		break;
4118 	case PACKET_LOSS:
4119 		val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS);
4120 		break;
4121 	case PACKET_TIMESTAMP:
4122 		val = READ_ONCE(po->tp_tstamp);
4123 		break;
4124 	case PACKET_FANOUT:
4125 		val = (po->fanout ?
4126 		       ((u32)po->fanout->id |
4127 			((u32)po->fanout->type << 16) |
4128 			((u32)po->fanout->flags << 24)) :
4129 		       0);
4130 		break;
4131 	case PACKET_IGNORE_OUTGOING:
4132 		val = po->prot_hook.ignore_outgoing;
4133 		break;
4134 	case PACKET_ROLLOVER_STATS:
4135 		if (!po->rollover)
4136 			return -EINVAL;
4137 		rstats.tp_all = atomic_long_read(&po->rollover->num);
4138 		rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4139 		rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4140 		data = &rstats;
4141 		lv = sizeof(rstats);
4142 		break;
4143 	case PACKET_TX_HAS_OFF:
4144 		val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF);
4145 		break;
4146 	case PACKET_QDISC_BYPASS:
4147 		val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS);
4148 		break;
4149 	default:
4150 		return -ENOPROTOOPT;
4151 	}
4152 
4153 	if (len > lv)
4154 		len = lv;
4155 	if (put_user(len, optlen))
4156 		return -EFAULT;
4157 	if (copy_to_user(optval, data, len))
4158 		return -EFAULT;
4159 	return 0;
4160 }
4161 
4162 static int packet_notifier(struct notifier_block *this,
4163 			   unsigned long msg, void *ptr)
4164 {
4165 	struct sock *sk;
4166 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4167 	struct net *net = dev_net(dev);
4168 
4169 	rcu_read_lock();
4170 	sk_for_each_rcu(sk, &net->packet.sklist) {
4171 		struct packet_sock *po = pkt_sk(sk);
4172 
4173 		switch (msg) {
4174 		case NETDEV_UNREGISTER:
4175 			if (po->mclist)
4176 				packet_dev_mclist_delete(dev, &po->mclist);
4177 			fallthrough;
4178 
4179 		case NETDEV_DOWN:
4180 			if (dev->ifindex == po->ifindex) {
4181 				spin_lock(&po->bind_lock);
4182 				if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) {
4183 					__unregister_prot_hook(sk, false);
4184 					sk->sk_err = ENETDOWN;
4185 					if (!sock_flag(sk, SOCK_DEAD))
4186 						sk_error_report(sk);
4187 				}
4188 				if (msg == NETDEV_UNREGISTER) {
4189 					packet_cached_dev_reset(po);
4190 					WRITE_ONCE(po->ifindex, -1);
4191 					netdev_put(po->prot_hook.dev,
4192 						   &po->prot_hook.dev_tracker);
4193 					po->prot_hook.dev = NULL;
4194 				}
4195 				spin_unlock(&po->bind_lock);
4196 			}
4197 			break;
4198 		case NETDEV_UP:
4199 			if (dev->ifindex == po->ifindex) {
4200 				spin_lock(&po->bind_lock);
4201 				if (po->num)
4202 					register_prot_hook(sk);
4203 				spin_unlock(&po->bind_lock);
4204 			}
4205 			break;
4206 		}
4207 	}
4208 	rcu_read_unlock();
4209 	return NOTIFY_DONE;
4210 }
4211 
4212 
4213 static int packet_ioctl(struct socket *sock, unsigned int cmd,
4214 			unsigned long arg)
4215 {
4216 	struct sock *sk = sock->sk;
4217 
4218 	switch (cmd) {
4219 	case SIOCOUTQ:
4220 	{
4221 		int amount = sk_wmem_alloc_get(sk);
4222 
4223 		return put_user(amount, (int __user *)arg);
4224 	}
4225 	case SIOCINQ:
4226 	{
4227 		struct sk_buff *skb;
4228 		int amount = 0;
4229 
4230 		spin_lock_bh(&sk->sk_receive_queue.lock);
4231 		skb = skb_peek(&sk->sk_receive_queue);
4232 		if (skb)
4233 			amount = skb->len;
4234 		spin_unlock_bh(&sk->sk_receive_queue.lock);
4235 		return put_user(amount, (int __user *)arg);
4236 	}
4237 #ifdef CONFIG_INET
4238 	case SIOCADDRT:
4239 	case SIOCDELRT:
4240 	case SIOCDARP:
4241 	case SIOCGARP:
4242 	case SIOCSARP:
4243 	case SIOCGIFADDR:
4244 	case SIOCSIFADDR:
4245 	case SIOCGIFBRDADDR:
4246 	case SIOCSIFBRDADDR:
4247 	case SIOCGIFNETMASK:
4248 	case SIOCSIFNETMASK:
4249 	case SIOCGIFDSTADDR:
4250 	case SIOCSIFDSTADDR:
4251 	case SIOCSIFFLAGS:
4252 		return inet_dgram_ops.ioctl(sock, cmd, arg);
4253 #endif
4254 
4255 	default:
4256 		return -ENOIOCTLCMD;
4257 	}
4258 	return 0;
4259 }
4260 
4261 static __poll_t packet_poll(struct file *file, struct socket *sock,
4262 				poll_table *wait)
4263 {
4264 	struct sock *sk = sock->sk;
4265 	struct packet_sock *po = pkt_sk(sk);
4266 	__poll_t mask = datagram_poll(file, sock, wait);
4267 
4268 	spin_lock_bh(&sk->sk_receive_queue.lock);
4269 	if (po->rx_ring.pg_vec) {
4270 		if (!packet_previous_rx_frame(po, &po->rx_ring,
4271 			TP_STATUS_KERNEL))
4272 			mask |= EPOLLIN | EPOLLRDNORM;
4273 	}
4274 	packet_rcv_try_clear_pressure(po);
4275 	spin_unlock_bh(&sk->sk_receive_queue.lock);
4276 	spin_lock_bh(&sk->sk_write_queue.lock);
4277 	if (po->tx_ring.pg_vec) {
4278 		if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4279 			mask |= EPOLLOUT | EPOLLWRNORM;
4280 	}
4281 	spin_unlock_bh(&sk->sk_write_queue.lock);
4282 	return mask;
4283 }
4284 
4285 
4286 /* Dirty? Well, I still did not learn better way to account
4287  * for user mmaps.
4288  */
4289 
4290 static void packet_mm_open(struct vm_area_struct *vma)
4291 {
4292 	struct file *file = vma->vm_file;
4293 	struct socket *sock = file->private_data;
4294 	struct sock *sk = sock->sk;
4295 
4296 	if (sk)
4297 		atomic_long_inc(&pkt_sk(sk)->mapped);
4298 }
4299 
4300 static void packet_mm_close(struct vm_area_struct *vma)
4301 {
4302 	struct file *file = vma->vm_file;
4303 	struct socket *sock = file->private_data;
4304 	struct sock *sk = sock->sk;
4305 
4306 	if (sk)
4307 		atomic_long_dec(&pkt_sk(sk)->mapped);
4308 }
4309 
4310 static const struct vm_operations_struct packet_mmap_ops = {
4311 	.open	=	packet_mm_open,
4312 	.close	=	packet_mm_close,
4313 };
4314 
4315 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4316 			unsigned int len)
4317 {
4318 	int i;
4319 
4320 	for (i = 0; i < len; i++) {
4321 		if (likely(pg_vec[i].buffer)) {
4322 			if (is_vmalloc_addr(pg_vec[i].buffer))
4323 				vfree(pg_vec[i].buffer);
4324 			else
4325 				free_pages((unsigned long)pg_vec[i].buffer,
4326 					   order);
4327 			pg_vec[i].buffer = NULL;
4328 		}
4329 	}
4330 	kfree(pg_vec);
4331 }
4332 
4333 static char *alloc_one_pg_vec_page(unsigned long order)
4334 {
4335 	char *buffer;
4336 	gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4337 			  __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4338 
4339 	buffer = (char *) __get_free_pages(gfp_flags, order);
4340 	if (buffer)
4341 		return buffer;
4342 
4343 	/* __get_free_pages failed, fall back to vmalloc */
4344 	buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4345 	if (buffer)
4346 		return buffer;
4347 
4348 	/* vmalloc failed, lets dig into swap here */
4349 	gfp_flags &= ~__GFP_NORETRY;
4350 	buffer = (char *) __get_free_pages(gfp_flags, order);
4351 	if (buffer)
4352 		return buffer;
4353 
4354 	/* complete and utter failure */
4355 	return NULL;
4356 }
4357 
4358 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4359 {
4360 	unsigned int block_nr = req->tp_block_nr;
4361 	struct pgv *pg_vec;
4362 	int i;
4363 
4364 	pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4365 	if (unlikely(!pg_vec))
4366 		goto out;
4367 
4368 	for (i = 0; i < block_nr; i++) {
4369 		pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4370 		if (unlikely(!pg_vec[i].buffer))
4371 			goto out_free_pgvec;
4372 	}
4373 
4374 out:
4375 	return pg_vec;
4376 
4377 out_free_pgvec:
4378 	free_pg_vec(pg_vec, order, block_nr);
4379 	pg_vec = NULL;
4380 	goto out;
4381 }
4382 
4383 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4384 		int closing, int tx_ring)
4385 {
4386 	struct pgv *pg_vec = NULL;
4387 	struct packet_sock *po = pkt_sk(sk);
4388 	unsigned long *rx_owner_map = NULL;
4389 	int was_running, order = 0;
4390 	struct packet_ring_buffer *rb;
4391 	struct sk_buff_head *rb_queue;
4392 	__be16 num;
4393 	int err;
4394 	/* Added to avoid minimal code churn */
4395 	struct tpacket_req *req = &req_u->req;
4396 
4397 	rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4398 	rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4399 
4400 	err = -EBUSY;
4401 	if (!closing) {
4402 		if (atomic_long_read(&po->mapped))
4403 			goto out;
4404 		if (packet_read_pending(rb))
4405 			goto out;
4406 	}
4407 
4408 	if (req->tp_block_nr) {
4409 		unsigned int min_frame_size;
4410 
4411 		/* Sanity tests and some calculations */
4412 		err = -EBUSY;
4413 		if (unlikely(rb->pg_vec))
4414 			goto out;
4415 
4416 		switch (po->tp_version) {
4417 		case TPACKET_V1:
4418 			po->tp_hdrlen = TPACKET_HDRLEN;
4419 			break;
4420 		case TPACKET_V2:
4421 			po->tp_hdrlen = TPACKET2_HDRLEN;
4422 			break;
4423 		case TPACKET_V3:
4424 			po->tp_hdrlen = TPACKET3_HDRLEN;
4425 			break;
4426 		}
4427 
4428 		err = -EINVAL;
4429 		if (unlikely((int)req->tp_block_size <= 0))
4430 			goto out;
4431 		if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4432 			goto out;
4433 		min_frame_size = po->tp_hdrlen + po->tp_reserve;
4434 		if (po->tp_version >= TPACKET_V3 &&
4435 		    req->tp_block_size <
4436 		    BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4437 			goto out;
4438 		if (unlikely(req->tp_frame_size < min_frame_size))
4439 			goto out;
4440 		if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4441 			goto out;
4442 
4443 		rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4444 		if (unlikely(rb->frames_per_block == 0))
4445 			goto out;
4446 		if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4447 			goto out;
4448 		if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4449 					req->tp_frame_nr))
4450 			goto out;
4451 
4452 		err = -ENOMEM;
4453 		order = get_order(req->tp_block_size);
4454 		pg_vec = alloc_pg_vec(req, order);
4455 		if (unlikely(!pg_vec))
4456 			goto out;
4457 		switch (po->tp_version) {
4458 		case TPACKET_V3:
4459 			/* Block transmit is not supported yet */
4460 			if (!tx_ring) {
4461 				init_prb_bdqc(po, rb, pg_vec, req_u);
4462 			} else {
4463 				struct tpacket_req3 *req3 = &req_u->req3;
4464 
4465 				if (req3->tp_retire_blk_tov ||
4466 				    req3->tp_sizeof_priv ||
4467 				    req3->tp_feature_req_word) {
4468 					err = -EINVAL;
4469 					goto out_free_pg_vec;
4470 				}
4471 			}
4472 			break;
4473 		default:
4474 			if (!tx_ring) {
4475 				rx_owner_map = bitmap_alloc(req->tp_frame_nr,
4476 					GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
4477 				if (!rx_owner_map)
4478 					goto out_free_pg_vec;
4479 			}
4480 			break;
4481 		}
4482 	}
4483 	/* Done */
4484 	else {
4485 		err = -EINVAL;
4486 		if (unlikely(req->tp_frame_nr))
4487 			goto out;
4488 	}
4489 
4490 
4491 	/* Detach socket from network */
4492 	spin_lock(&po->bind_lock);
4493 	was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING);
4494 	num = po->num;
4495 	if (was_running) {
4496 		WRITE_ONCE(po->num, 0);
4497 		__unregister_prot_hook(sk, false);
4498 	}
4499 	spin_unlock(&po->bind_lock);
4500 
4501 	synchronize_net();
4502 
4503 	err = -EBUSY;
4504 	mutex_lock(&po->pg_vec_lock);
4505 	if (closing || atomic_long_read(&po->mapped) == 0) {
4506 		err = 0;
4507 		spin_lock_bh(&rb_queue->lock);
4508 		swap(rb->pg_vec, pg_vec);
4509 		if (po->tp_version <= TPACKET_V2)
4510 			swap(rb->rx_owner_map, rx_owner_map);
4511 		rb->frame_max = (req->tp_frame_nr - 1);
4512 		rb->head = 0;
4513 		rb->frame_size = req->tp_frame_size;
4514 		spin_unlock_bh(&rb_queue->lock);
4515 
4516 		swap(rb->pg_vec_order, order);
4517 		swap(rb->pg_vec_len, req->tp_block_nr);
4518 
4519 		rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4520 		po->prot_hook.func = (po->rx_ring.pg_vec) ?
4521 						tpacket_rcv : packet_rcv;
4522 		skb_queue_purge(rb_queue);
4523 		if (atomic_long_read(&po->mapped))
4524 			pr_err("packet_mmap: vma is busy: %ld\n",
4525 			       atomic_long_read(&po->mapped));
4526 	}
4527 	mutex_unlock(&po->pg_vec_lock);
4528 
4529 	spin_lock(&po->bind_lock);
4530 	if (was_running) {
4531 		WRITE_ONCE(po->num, num);
4532 		register_prot_hook(sk);
4533 	}
4534 	spin_unlock(&po->bind_lock);
4535 	if (pg_vec && (po->tp_version > TPACKET_V2)) {
4536 		/* Because we don't support block-based V3 on tx-ring */
4537 		if (!tx_ring)
4538 			prb_shutdown_retire_blk_timer(po, rb_queue);
4539 	}
4540 
4541 out_free_pg_vec:
4542 	if (pg_vec) {
4543 		bitmap_free(rx_owner_map);
4544 		free_pg_vec(pg_vec, order, req->tp_block_nr);
4545 	}
4546 out:
4547 	return err;
4548 }
4549 
4550 static int packet_mmap(struct file *file, struct socket *sock,
4551 		struct vm_area_struct *vma)
4552 {
4553 	struct sock *sk = sock->sk;
4554 	struct packet_sock *po = pkt_sk(sk);
4555 	unsigned long size, expected_size;
4556 	struct packet_ring_buffer *rb;
4557 	unsigned long start;
4558 	int err = -EINVAL;
4559 	int i;
4560 
4561 	if (vma->vm_pgoff)
4562 		return -EINVAL;
4563 
4564 	mutex_lock(&po->pg_vec_lock);
4565 
4566 	expected_size = 0;
4567 	for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4568 		if (rb->pg_vec) {
4569 			expected_size += rb->pg_vec_len
4570 						* rb->pg_vec_pages
4571 						* PAGE_SIZE;
4572 		}
4573 	}
4574 
4575 	if (expected_size == 0)
4576 		goto out;
4577 
4578 	size = vma->vm_end - vma->vm_start;
4579 	if (size != expected_size)
4580 		goto out;
4581 
4582 	start = vma->vm_start;
4583 	for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4584 		if (rb->pg_vec == NULL)
4585 			continue;
4586 
4587 		for (i = 0; i < rb->pg_vec_len; i++) {
4588 			struct page *page;
4589 			void *kaddr = rb->pg_vec[i].buffer;
4590 			int pg_num;
4591 
4592 			for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4593 				page = pgv_to_page(kaddr);
4594 				err = vm_insert_page(vma, start, page);
4595 				if (unlikely(err))
4596 					goto out;
4597 				start += PAGE_SIZE;
4598 				kaddr += PAGE_SIZE;
4599 			}
4600 		}
4601 	}
4602 
4603 	atomic_long_inc(&po->mapped);
4604 	vma->vm_ops = &packet_mmap_ops;
4605 	err = 0;
4606 
4607 out:
4608 	mutex_unlock(&po->pg_vec_lock);
4609 	return err;
4610 }
4611 
4612 static const struct proto_ops packet_ops_spkt = {
4613 	.family =	PF_PACKET,
4614 	.owner =	THIS_MODULE,
4615 	.release =	packet_release,
4616 	.bind =		packet_bind_spkt,
4617 	.connect =	sock_no_connect,
4618 	.socketpair =	sock_no_socketpair,
4619 	.accept =	sock_no_accept,
4620 	.getname =	packet_getname_spkt,
4621 	.poll =		datagram_poll,
4622 	.ioctl =	packet_ioctl,
4623 	.gettstamp =	sock_gettstamp,
4624 	.listen =	sock_no_listen,
4625 	.shutdown =	sock_no_shutdown,
4626 	.sendmsg =	packet_sendmsg_spkt,
4627 	.recvmsg =	packet_recvmsg,
4628 	.mmap =		sock_no_mmap,
4629 };
4630 
4631 static const struct proto_ops packet_ops = {
4632 	.family =	PF_PACKET,
4633 	.owner =	THIS_MODULE,
4634 	.release =	packet_release,
4635 	.bind =		packet_bind,
4636 	.connect =	sock_no_connect,
4637 	.socketpair =	sock_no_socketpair,
4638 	.accept =	sock_no_accept,
4639 	.getname =	packet_getname,
4640 	.poll =		packet_poll,
4641 	.ioctl =	packet_ioctl,
4642 	.gettstamp =	sock_gettstamp,
4643 	.listen =	sock_no_listen,
4644 	.shutdown =	sock_no_shutdown,
4645 	.setsockopt =	packet_setsockopt,
4646 	.getsockopt =	packet_getsockopt,
4647 	.sendmsg =	packet_sendmsg,
4648 	.recvmsg =	packet_recvmsg,
4649 	.mmap =		packet_mmap,
4650 };
4651 
4652 static const struct net_proto_family packet_family_ops = {
4653 	.family =	PF_PACKET,
4654 	.create =	packet_create,
4655 	.owner	=	THIS_MODULE,
4656 };
4657 
4658 static struct notifier_block packet_netdev_notifier = {
4659 	.notifier_call =	packet_notifier,
4660 };
4661 
4662 #ifdef CONFIG_PROC_FS
4663 
4664 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4665 	__acquires(RCU)
4666 {
4667 	struct net *net = seq_file_net(seq);
4668 
4669 	rcu_read_lock();
4670 	return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4671 }
4672 
4673 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4674 {
4675 	struct net *net = seq_file_net(seq);
4676 	return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4677 }
4678 
4679 static void packet_seq_stop(struct seq_file *seq, void *v)
4680 	__releases(RCU)
4681 {
4682 	rcu_read_unlock();
4683 }
4684 
4685 static int packet_seq_show(struct seq_file *seq, void *v)
4686 {
4687 	if (v == SEQ_START_TOKEN)
4688 		seq_printf(seq,
4689 			   "%*sRefCnt Type Proto  Iface R Rmem   User   Inode\n",
4690 			   IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk");
4691 	else {
4692 		struct sock *s = sk_entry(v);
4693 		const struct packet_sock *po = pkt_sk(s);
4694 
4695 		seq_printf(seq,
4696 			   "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4697 			   s,
4698 			   refcount_read(&s->sk_refcnt),
4699 			   s->sk_type,
4700 			   ntohs(READ_ONCE(po->num)),
4701 			   READ_ONCE(po->ifindex),
4702 			   packet_sock_flag(po, PACKET_SOCK_RUNNING),
4703 			   atomic_read(&s->sk_rmem_alloc),
4704 			   from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4705 			   sock_i_ino(s));
4706 	}
4707 
4708 	return 0;
4709 }
4710 
4711 static const struct seq_operations packet_seq_ops = {
4712 	.start	= packet_seq_start,
4713 	.next	= packet_seq_next,
4714 	.stop	= packet_seq_stop,
4715 	.show	= packet_seq_show,
4716 };
4717 #endif
4718 
4719 static int __net_init packet_net_init(struct net *net)
4720 {
4721 	mutex_init(&net->packet.sklist_lock);
4722 	INIT_HLIST_HEAD(&net->packet.sklist);
4723 
4724 #ifdef CONFIG_PROC_FS
4725 	if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4726 			sizeof(struct seq_net_private)))
4727 		return -ENOMEM;
4728 #endif /* CONFIG_PROC_FS */
4729 
4730 	return 0;
4731 }
4732 
4733 static void __net_exit packet_net_exit(struct net *net)
4734 {
4735 	remove_proc_entry("packet", net->proc_net);
4736 	WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4737 }
4738 
4739 static struct pernet_operations packet_net_ops = {
4740 	.init = packet_net_init,
4741 	.exit = packet_net_exit,
4742 };
4743 
4744 
4745 static void __exit packet_exit(void)
4746 {
4747 	sock_unregister(PF_PACKET);
4748 	proto_unregister(&packet_proto);
4749 	unregister_netdevice_notifier(&packet_netdev_notifier);
4750 	unregister_pernet_subsys(&packet_net_ops);
4751 }
4752 
4753 static int __init packet_init(void)
4754 {
4755 	int rc;
4756 
4757 	rc = register_pernet_subsys(&packet_net_ops);
4758 	if (rc)
4759 		goto out;
4760 	rc = register_netdevice_notifier(&packet_netdev_notifier);
4761 	if (rc)
4762 		goto out_pernet;
4763 	rc = proto_register(&packet_proto, 0);
4764 	if (rc)
4765 		goto out_notifier;
4766 	rc = sock_register(&packet_family_ops);
4767 	if (rc)
4768 		goto out_proto;
4769 
4770 	return 0;
4771 
4772 out_proto:
4773 	proto_unregister(&packet_proto);
4774 out_notifier:
4775 	unregister_netdevice_notifier(&packet_netdev_notifier);
4776 out_pernet:
4777 	unregister_pernet_subsys(&packet_net_ops);
4778 out:
4779 	return rc;
4780 }
4781 
4782 module_init(packet_init);
4783 module_exit(packet_exit);
4784 MODULE_DESCRIPTION("Packet socket support (AF_PACKET)");
4785 MODULE_LICENSE("GPL");
4786 MODULE_ALIAS_NETPROTO(PF_PACKET);
4787