xref: /linux-6.15/net/openvswitch/datapath.c (revision bbb03029)
1 /*
2  * Copyright (c) 2007-2014 Nicira, Inc.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of version 2 of the GNU General Public
6  * License as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16  * 02110-1301, USA
17  */
18 
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/if_arp.h>
24 #include <linux/if_vlan.h>
25 #include <linux/in.h>
26 #include <linux/ip.h>
27 #include <linux/jhash.h>
28 #include <linux/delay.h>
29 #include <linux/time.h>
30 #include <linux/etherdevice.h>
31 #include <linux/genetlink.h>
32 #include <linux/kernel.h>
33 #include <linux/kthread.h>
34 #include <linux/mutex.h>
35 #include <linux/percpu.h>
36 #include <linux/rcupdate.h>
37 #include <linux/tcp.h>
38 #include <linux/udp.h>
39 #include <linux/ethtool.h>
40 #include <linux/wait.h>
41 #include <asm/div64.h>
42 #include <linux/highmem.h>
43 #include <linux/netfilter_bridge.h>
44 #include <linux/netfilter_ipv4.h>
45 #include <linux/inetdevice.h>
46 #include <linux/list.h>
47 #include <linux/openvswitch.h>
48 #include <linux/rculist.h>
49 #include <linux/dmi.h>
50 #include <net/genetlink.h>
51 #include <net/net_namespace.h>
52 #include <net/netns/generic.h>
53 
54 #include "datapath.h"
55 #include "flow.h"
56 #include "flow_table.h"
57 #include "flow_netlink.h"
58 #include "vport-internal_dev.h"
59 #include "vport-netdev.h"
60 
61 unsigned int ovs_net_id __read_mostly;
62 
63 static struct genl_family dp_packet_genl_family;
64 static struct genl_family dp_flow_genl_family;
65 static struct genl_family dp_datapath_genl_family;
66 
67 static const struct nla_policy flow_policy[];
68 
69 static const struct genl_multicast_group ovs_dp_flow_multicast_group = {
70 	.name = OVS_FLOW_MCGROUP,
71 };
72 
73 static const struct genl_multicast_group ovs_dp_datapath_multicast_group = {
74 	.name = OVS_DATAPATH_MCGROUP,
75 };
76 
77 static const struct genl_multicast_group ovs_dp_vport_multicast_group = {
78 	.name = OVS_VPORT_MCGROUP,
79 };
80 
81 /* Check if need to build a reply message.
82  * OVS userspace sets the NLM_F_ECHO flag if it needs the reply. */
83 static bool ovs_must_notify(struct genl_family *family, struct genl_info *info,
84 			    unsigned int group)
85 {
86 	return info->nlhdr->nlmsg_flags & NLM_F_ECHO ||
87 	       genl_has_listeners(family, genl_info_net(info), group);
88 }
89 
90 static void ovs_notify(struct genl_family *family,
91 		       struct sk_buff *skb, struct genl_info *info)
92 {
93 	genl_notify(family, skb, info, 0, GFP_KERNEL);
94 }
95 
96 /**
97  * DOC: Locking:
98  *
99  * All writes e.g. Writes to device state (add/remove datapath, port, set
100  * operations on vports, etc.), Writes to other state (flow table
101  * modifications, set miscellaneous datapath parameters, etc.) are protected
102  * by ovs_lock.
103  *
104  * Reads are protected by RCU.
105  *
106  * There are a few special cases (mostly stats) that have their own
107  * synchronization but they nest under all of above and don't interact with
108  * each other.
109  *
110  * The RTNL lock nests inside ovs_mutex.
111  */
112 
113 static DEFINE_MUTEX(ovs_mutex);
114 
115 void ovs_lock(void)
116 {
117 	mutex_lock(&ovs_mutex);
118 }
119 
120 void ovs_unlock(void)
121 {
122 	mutex_unlock(&ovs_mutex);
123 }
124 
125 #ifdef CONFIG_LOCKDEP
126 int lockdep_ovsl_is_held(void)
127 {
128 	if (debug_locks)
129 		return lockdep_is_held(&ovs_mutex);
130 	else
131 		return 1;
132 }
133 #endif
134 
135 static struct vport *new_vport(const struct vport_parms *);
136 static int queue_gso_packets(struct datapath *dp, struct sk_buff *,
137 			     const struct sw_flow_key *,
138 			     const struct dp_upcall_info *,
139 			     uint32_t cutlen);
140 static int queue_userspace_packet(struct datapath *dp, struct sk_buff *,
141 				  const struct sw_flow_key *,
142 				  const struct dp_upcall_info *,
143 				  uint32_t cutlen);
144 
145 /* Must be called with rcu_read_lock. */
146 static struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
147 {
148 	struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
149 
150 	if (dev) {
151 		struct vport *vport = ovs_internal_dev_get_vport(dev);
152 		if (vport)
153 			return vport->dp;
154 	}
155 
156 	return NULL;
157 }
158 
159 /* The caller must hold either ovs_mutex or rcu_read_lock to keep the
160  * returned dp pointer valid.
161  */
162 static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
163 {
164 	struct datapath *dp;
165 
166 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
167 	rcu_read_lock();
168 	dp = get_dp_rcu(net, dp_ifindex);
169 	rcu_read_unlock();
170 
171 	return dp;
172 }
173 
174 /* Must be called with rcu_read_lock or ovs_mutex. */
175 const char *ovs_dp_name(const struct datapath *dp)
176 {
177 	struct vport *vport = ovs_vport_ovsl_rcu(dp, OVSP_LOCAL);
178 	return ovs_vport_name(vport);
179 }
180 
181 static int get_dpifindex(const struct datapath *dp)
182 {
183 	struct vport *local;
184 	int ifindex;
185 
186 	rcu_read_lock();
187 
188 	local = ovs_vport_rcu(dp, OVSP_LOCAL);
189 	if (local)
190 		ifindex = local->dev->ifindex;
191 	else
192 		ifindex = 0;
193 
194 	rcu_read_unlock();
195 
196 	return ifindex;
197 }
198 
199 static void destroy_dp_rcu(struct rcu_head *rcu)
200 {
201 	struct datapath *dp = container_of(rcu, struct datapath, rcu);
202 
203 	ovs_flow_tbl_destroy(&dp->table);
204 	free_percpu(dp->stats_percpu);
205 	kfree(dp->ports);
206 	kfree(dp);
207 }
208 
209 static struct hlist_head *vport_hash_bucket(const struct datapath *dp,
210 					    u16 port_no)
211 {
212 	return &dp->ports[port_no & (DP_VPORT_HASH_BUCKETS - 1)];
213 }
214 
215 /* Called with ovs_mutex or RCU read lock. */
216 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no)
217 {
218 	struct vport *vport;
219 	struct hlist_head *head;
220 
221 	head = vport_hash_bucket(dp, port_no);
222 	hlist_for_each_entry_rcu(vport, head, dp_hash_node) {
223 		if (vport->port_no == port_no)
224 			return vport;
225 	}
226 	return NULL;
227 }
228 
229 /* Called with ovs_mutex. */
230 static struct vport *new_vport(const struct vport_parms *parms)
231 {
232 	struct vport *vport;
233 
234 	vport = ovs_vport_add(parms);
235 	if (!IS_ERR(vport)) {
236 		struct datapath *dp = parms->dp;
237 		struct hlist_head *head = vport_hash_bucket(dp, vport->port_no);
238 
239 		hlist_add_head_rcu(&vport->dp_hash_node, head);
240 	}
241 	return vport;
242 }
243 
244 void ovs_dp_detach_port(struct vport *p)
245 {
246 	ASSERT_OVSL();
247 
248 	/* First drop references to device. */
249 	hlist_del_rcu(&p->dp_hash_node);
250 
251 	/* Then destroy it. */
252 	ovs_vport_del(p);
253 }
254 
255 /* Must be called with rcu_read_lock. */
256 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key)
257 {
258 	const struct vport *p = OVS_CB(skb)->input_vport;
259 	struct datapath *dp = p->dp;
260 	struct sw_flow *flow;
261 	struct sw_flow_actions *sf_acts;
262 	struct dp_stats_percpu *stats;
263 	u64 *stats_counter;
264 	u32 n_mask_hit;
265 
266 	stats = this_cpu_ptr(dp->stats_percpu);
267 
268 	/* Look up flow. */
269 	flow = ovs_flow_tbl_lookup_stats(&dp->table, key, &n_mask_hit);
270 	if (unlikely(!flow)) {
271 		struct dp_upcall_info upcall;
272 		int error;
273 
274 		memset(&upcall, 0, sizeof(upcall));
275 		upcall.cmd = OVS_PACKET_CMD_MISS;
276 		upcall.portid = ovs_vport_find_upcall_portid(p, skb);
277 		upcall.mru = OVS_CB(skb)->mru;
278 		error = ovs_dp_upcall(dp, skb, key, &upcall, 0);
279 		if (unlikely(error))
280 			kfree_skb(skb);
281 		else
282 			consume_skb(skb);
283 		stats_counter = &stats->n_missed;
284 		goto out;
285 	}
286 
287 	ovs_flow_stats_update(flow, key->tp.flags, skb);
288 	sf_acts = rcu_dereference(flow->sf_acts);
289 	ovs_execute_actions(dp, skb, sf_acts, key);
290 
291 	stats_counter = &stats->n_hit;
292 
293 out:
294 	/* Update datapath statistics. */
295 	u64_stats_update_begin(&stats->syncp);
296 	(*stats_counter)++;
297 	stats->n_mask_hit += n_mask_hit;
298 	u64_stats_update_end(&stats->syncp);
299 }
300 
301 int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
302 		  const struct sw_flow_key *key,
303 		  const struct dp_upcall_info *upcall_info,
304 		  uint32_t cutlen)
305 {
306 	struct dp_stats_percpu *stats;
307 	int err;
308 
309 	if (upcall_info->portid == 0) {
310 		err = -ENOTCONN;
311 		goto err;
312 	}
313 
314 	if (!skb_is_gso(skb))
315 		err = queue_userspace_packet(dp, skb, key, upcall_info, cutlen);
316 	else
317 		err = queue_gso_packets(dp, skb, key, upcall_info, cutlen);
318 	if (err)
319 		goto err;
320 
321 	return 0;
322 
323 err:
324 	stats = this_cpu_ptr(dp->stats_percpu);
325 
326 	u64_stats_update_begin(&stats->syncp);
327 	stats->n_lost++;
328 	u64_stats_update_end(&stats->syncp);
329 
330 	return err;
331 }
332 
333 static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
334 			     const struct sw_flow_key *key,
335 			     const struct dp_upcall_info *upcall_info,
336 				 uint32_t cutlen)
337 {
338 	struct sk_buff *segs, *nskb;
339 	int err;
340 
341 	BUILD_BUG_ON(sizeof(*OVS_CB(skb)) > SKB_SGO_CB_OFFSET);
342 	segs = __skb_gso_segment(skb, NETIF_F_SG, false);
343 	if (IS_ERR(segs))
344 		return PTR_ERR(segs);
345 	if (segs == NULL)
346 		return -EINVAL;
347 
348 	/* Queue all of the segments. */
349 	skb = segs;
350 	do {
351 		err = queue_userspace_packet(dp, skb, key, upcall_info, cutlen);
352 		if (err)
353 			break;
354 
355 	} while ((skb = skb->next));
356 
357 	/* Free all of the segments. */
358 	skb = segs;
359 	do {
360 		nskb = skb->next;
361 		if (err)
362 			kfree_skb(skb);
363 		else
364 			consume_skb(skb);
365 	} while ((skb = nskb));
366 	return err;
367 }
368 
369 static size_t upcall_msg_size(const struct dp_upcall_info *upcall_info,
370 			      unsigned int hdrlen)
371 {
372 	size_t size = NLMSG_ALIGN(sizeof(struct ovs_header))
373 		+ nla_total_size(hdrlen) /* OVS_PACKET_ATTR_PACKET */
374 		+ nla_total_size(ovs_key_attr_size()) /* OVS_PACKET_ATTR_KEY */
375 		+ nla_total_size(sizeof(unsigned int)); /* OVS_PACKET_ATTR_LEN */
376 
377 	/* OVS_PACKET_ATTR_USERDATA */
378 	if (upcall_info->userdata)
379 		size += NLA_ALIGN(upcall_info->userdata->nla_len);
380 
381 	/* OVS_PACKET_ATTR_EGRESS_TUN_KEY */
382 	if (upcall_info->egress_tun_info)
383 		size += nla_total_size(ovs_tun_key_attr_size());
384 
385 	/* OVS_PACKET_ATTR_ACTIONS */
386 	if (upcall_info->actions_len)
387 		size += nla_total_size(upcall_info->actions_len);
388 
389 	/* OVS_PACKET_ATTR_MRU */
390 	if (upcall_info->mru)
391 		size += nla_total_size(sizeof(upcall_info->mru));
392 
393 	return size;
394 }
395 
396 static void pad_packet(struct datapath *dp, struct sk_buff *skb)
397 {
398 	if (!(dp->user_features & OVS_DP_F_UNALIGNED)) {
399 		size_t plen = NLA_ALIGN(skb->len) - skb->len;
400 
401 		if (plen > 0)
402 			skb_put_zero(skb, plen);
403 	}
404 }
405 
406 static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
407 				  const struct sw_flow_key *key,
408 				  const struct dp_upcall_info *upcall_info,
409 				  uint32_t cutlen)
410 {
411 	struct ovs_header *upcall;
412 	struct sk_buff *nskb = NULL;
413 	struct sk_buff *user_skb = NULL; /* to be queued to userspace */
414 	struct nlattr *nla;
415 	size_t len;
416 	unsigned int hlen;
417 	int err, dp_ifindex;
418 
419 	dp_ifindex = get_dpifindex(dp);
420 	if (!dp_ifindex)
421 		return -ENODEV;
422 
423 	if (skb_vlan_tag_present(skb)) {
424 		nskb = skb_clone(skb, GFP_ATOMIC);
425 		if (!nskb)
426 			return -ENOMEM;
427 
428 		nskb = __vlan_hwaccel_push_inside(nskb);
429 		if (!nskb)
430 			return -ENOMEM;
431 
432 		skb = nskb;
433 	}
434 
435 	if (nla_attr_size(skb->len) > USHRT_MAX) {
436 		err = -EFBIG;
437 		goto out;
438 	}
439 
440 	/* Complete checksum if needed */
441 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
442 	    (err = skb_csum_hwoffload_help(skb, 0)))
443 		goto out;
444 
445 	/* Older versions of OVS user space enforce alignment of the last
446 	 * Netlink attribute to NLA_ALIGNTO which would require extensive
447 	 * padding logic. Only perform zerocopy if padding is not required.
448 	 */
449 	if (dp->user_features & OVS_DP_F_UNALIGNED)
450 		hlen = skb_zerocopy_headlen(skb);
451 	else
452 		hlen = skb->len;
453 
454 	len = upcall_msg_size(upcall_info, hlen - cutlen);
455 	user_skb = genlmsg_new(len, GFP_ATOMIC);
456 	if (!user_skb) {
457 		err = -ENOMEM;
458 		goto out;
459 	}
460 
461 	upcall = genlmsg_put(user_skb, 0, 0, &dp_packet_genl_family,
462 			     0, upcall_info->cmd);
463 	upcall->dp_ifindex = dp_ifindex;
464 
465 	err = ovs_nla_put_key(key, key, OVS_PACKET_ATTR_KEY, false, user_skb);
466 	BUG_ON(err);
467 
468 	if (upcall_info->userdata)
469 		__nla_put(user_skb, OVS_PACKET_ATTR_USERDATA,
470 			  nla_len(upcall_info->userdata),
471 			  nla_data(upcall_info->userdata));
472 
473 	if (upcall_info->egress_tun_info) {
474 		nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_EGRESS_TUN_KEY);
475 		err = ovs_nla_put_tunnel_info(user_skb,
476 					      upcall_info->egress_tun_info);
477 		BUG_ON(err);
478 		nla_nest_end(user_skb, nla);
479 	}
480 
481 	if (upcall_info->actions_len) {
482 		nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_ACTIONS);
483 		err = ovs_nla_put_actions(upcall_info->actions,
484 					  upcall_info->actions_len,
485 					  user_skb);
486 		if (!err)
487 			nla_nest_end(user_skb, nla);
488 		else
489 			nla_nest_cancel(user_skb, nla);
490 	}
491 
492 	/* Add OVS_PACKET_ATTR_MRU */
493 	if (upcall_info->mru) {
494 		if (nla_put_u16(user_skb, OVS_PACKET_ATTR_MRU,
495 				upcall_info->mru)) {
496 			err = -ENOBUFS;
497 			goto out;
498 		}
499 		pad_packet(dp, user_skb);
500 	}
501 
502 	/* Add OVS_PACKET_ATTR_LEN when packet is truncated */
503 	if (cutlen > 0) {
504 		if (nla_put_u32(user_skb, OVS_PACKET_ATTR_LEN,
505 				skb->len)) {
506 			err = -ENOBUFS;
507 			goto out;
508 		}
509 		pad_packet(dp, user_skb);
510 	}
511 
512 	/* Only reserve room for attribute header, packet data is added
513 	 * in skb_zerocopy() */
514 	if (!(nla = nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, 0))) {
515 		err = -ENOBUFS;
516 		goto out;
517 	}
518 	nla->nla_len = nla_attr_size(skb->len - cutlen);
519 
520 	err = skb_zerocopy(user_skb, skb, skb->len - cutlen, hlen);
521 	if (err)
522 		goto out;
523 
524 	/* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */
525 	pad_packet(dp, user_skb);
526 
527 	((struct nlmsghdr *) user_skb->data)->nlmsg_len = user_skb->len;
528 
529 	err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid);
530 	user_skb = NULL;
531 out:
532 	if (err)
533 		skb_tx_error(skb);
534 	kfree_skb(user_skb);
535 	kfree_skb(nskb);
536 	return err;
537 }
538 
539 static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
540 {
541 	struct ovs_header *ovs_header = info->userhdr;
542 	struct net *net = sock_net(skb->sk);
543 	struct nlattr **a = info->attrs;
544 	struct sw_flow_actions *acts;
545 	struct sk_buff *packet;
546 	struct sw_flow *flow;
547 	struct sw_flow_actions *sf_acts;
548 	struct datapath *dp;
549 	struct vport *input_vport;
550 	u16 mru = 0;
551 	int len;
552 	int err;
553 	bool log = !a[OVS_PACKET_ATTR_PROBE];
554 
555 	err = -EINVAL;
556 	if (!a[OVS_PACKET_ATTR_PACKET] || !a[OVS_PACKET_ATTR_KEY] ||
557 	    !a[OVS_PACKET_ATTR_ACTIONS])
558 		goto err;
559 
560 	len = nla_len(a[OVS_PACKET_ATTR_PACKET]);
561 	packet = __dev_alloc_skb(NET_IP_ALIGN + len, GFP_KERNEL);
562 	err = -ENOMEM;
563 	if (!packet)
564 		goto err;
565 	skb_reserve(packet, NET_IP_ALIGN);
566 
567 	nla_memcpy(__skb_put(packet, len), a[OVS_PACKET_ATTR_PACKET], len);
568 
569 	/* Set packet's mru */
570 	if (a[OVS_PACKET_ATTR_MRU]) {
571 		mru = nla_get_u16(a[OVS_PACKET_ATTR_MRU]);
572 		packet->ignore_df = 1;
573 	}
574 	OVS_CB(packet)->mru = mru;
575 
576 	/* Build an sw_flow for sending this packet. */
577 	flow = ovs_flow_alloc();
578 	err = PTR_ERR(flow);
579 	if (IS_ERR(flow))
580 		goto err_kfree_skb;
581 
582 	err = ovs_flow_key_extract_userspace(net, a[OVS_PACKET_ATTR_KEY],
583 					     packet, &flow->key, log);
584 	if (err)
585 		goto err_flow_free;
586 
587 	err = ovs_nla_copy_actions(net, a[OVS_PACKET_ATTR_ACTIONS],
588 				   &flow->key, &acts, log);
589 	if (err)
590 		goto err_flow_free;
591 
592 	rcu_assign_pointer(flow->sf_acts, acts);
593 	packet->priority = flow->key.phy.priority;
594 	packet->mark = flow->key.phy.skb_mark;
595 
596 	rcu_read_lock();
597 	dp = get_dp_rcu(net, ovs_header->dp_ifindex);
598 	err = -ENODEV;
599 	if (!dp)
600 		goto err_unlock;
601 
602 	input_vport = ovs_vport_rcu(dp, flow->key.phy.in_port);
603 	if (!input_vport)
604 		input_vport = ovs_vport_rcu(dp, OVSP_LOCAL);
605 
606 	if (!input_vport)
607 		goto err_unlock;
608 
609 	packet->dev = input_vport->dev;
610 	OVS_CB(packet)->input_vport = input_vport;
611 	sf_acts = rcu_dereference(flow->sf_acts);
612 
613 	local_bh_disable();
614 	err = ovs_execute_actions(dp, packet, sf_acts, &flow->key);
615 	local_bh_enable();
616 	rcu_read_unlock();
617 
618 	ovs_flow_free(flow, false);
619 	return err;
620 
621 err_unlock:
622 	rcu_read_unlock();
623 err_flow_free:
624 	ovs_flow_free(flow, false);
625 err_kfree_skb:
626 	kfree_skb(packet);
627 err:
628 	return err;
629 }
630 
631 static const struct nla_policy packet_policy[OVS_PACKET_ATTR_MAX + 1] = {
632 	[OVS_PACKET_ATTR_PACKET] = { .len = ETH_HLEN },
633 	[OVS_PACKET_ATTR_KEY] = { .type = NLA_NESTED },
634 	[OVS_PACKET_ATTR_ACTIONS] = { .type = NLA_NESTED },
635 	[OVS_PACKET_ATTR_PROBE] = { .type = NLA_FLAG },
636 	[OVS_PACKET_ATTR_MRU] = { .type = NLA_U16 },
637 };
638 
639 static const struct genl_ops dp_packet_genl_ops[] = {
640 	{ .cmd = OVS_PACKET_CMD_EXECUTE,
641 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
642 	  .policy = packet_policy,
643 	  .doit = ovs_packet_cmd_execute
644 	}
645 };
646 
647 static struct genl_family dp_packet_genl_family __ro_after_init = {
648 	.hdrsize = sizeof(struct ovs_header),
649 	.name = OVS_PACKET_FAMILY,
650 	.version = OVS_PACKET_VERSION,
651 	.maxattr = OVS_PACKET_ATTR_MAX,
652 	.netnsok = true,
653 	.parallel_ops = true,
654 	.ops = dp_packet_genl_ops,
655 	.n_ops = ARRAY_SIZE(dp_packet_genl_ops),
656 	.module = THIS_MODULE,
657 };
658 
659 static void get_dp_stats(const struct datapath *dp, struct ovs_dp_stats *stats,
660 			 struct ovs_dp_megaflow_stats *mega_stats)
661 {
662 	int i;
663 
664 	memset(mega_stats, 0, sizeof(*mega_stats));
665 
666 	stats->n_flows = ovs_flow_tbl_count(&dp->table);
667 	mega_stats->n_masks = ovs_flow_tbl_num_masks(&dp->table);
668 
669 	stats->n_hit = stats->n_missed = stats->n_lost = 0;
670 
671 	for_each_possible_cpu(i) {
672 		const struct dp_stats_percpu *percpu_stats;
673 		struct dp_stats_percpu local_stats;
674 		unsigned int start;
675 
676 		percpu_stats = per_cpu_ptr(dp->stats_percpu, i);
677 
678 		do {
679 			start = u64_stats_fetch_begin_irq(&percpu_stats->syncp);
680 			local_stats = *percpu_stats;
681 		} while (u64_stats_fetch_retry_irq(&percpu_stats->syncp, start));
682 
683 		stats->n_hit += local_stats.n_hit;
684 		stats->n_missed += local_stats.n_missed;
685 		stats->n_lost += local_stats.n_lost;
686 		mega_stats->n_mask_hit += local_stats.n_mask_hit;
687 	}
688 }
689 
690 static bool should_fill_key(const struct sw_flow_id *sfid, uint32_t ufid_flags)
691 {
692 	return ovs_identifier_is_ufid(sfid) &&
693 	       !(ufid_flags & OVS_UFID_F_OMIT_KEY);
694 }
695 
696 static bool should_fill_mask(uint32_t ufid_flags)
697 {
698 	return !(ufid_flags & OVS_UFID_F_OMIT_MASK);
699 }
700 
701 static bool should_fill_actions(uint32_t ufid_flags)
702 {
703 	return !(ufid_flags & OVS_UFID_F_OMIT_ACTIONS);
704 }
705 
706 static size_t ovs_flow_cmd_msg_size(const struct sw_flow_actions *acts,
707 				    const struct sw_flow_id *sfid,
708 				    uint32_t ufid_flags)
709 {
710 	size_t len = NLMSG_ALIGN(sizeof(struct ovs_header));
711 
712 	/* OVS_FLOW_ATTR_UFID */
713 	if (sfid && ovs_identifier_is_ufid(sfid))
714 		len += nla_total_size(sfid->ufid_len);
715 
716 	/* OVS_FLOW_ATTR_KEY */
717 	if (!sfid || should_fill_key(sfid, ufid_flags))
718 		len += nla_total_size(ovs_key_attr_size());
719 
720 	/* OVS_FLOW_ATTR_MASK */
721 	if (should_fill_mask(ufid_flags))
722 		len += nla_total_size(ovs_key_attr_size());
723 
724 	/* OVS_FLOW_ATTR_ACTIONS */
725 	if (should_fill_actions(ufid_flags))
726 		len += nla_total_size(acts->orig_len);
727 
728 	return len
729 		+ nla_total_size_64bit(sizeof(struct ovs_flow_stats)) /* OVS_FLOW_ATTR_STATS */
730 		+ nla_total_size(1) /* OVS_FLOW_ATTR_TCP_FLAGS */
731 		+ nla_total_size_64bit(8); /* OVS_FLOW_ATTR_USED */
732 }
733 
734 /* Called with ovs_mutex or RCU read lock. */
735 static int ovs_flow_cmd_fill_stats(const struct sw_flow *flow,
736 				   struct sk_buff *skb)
737 {
738 	struct ovs_flow_stats stats;
739 	__be16 tcp_flags;
740 	unsigned long used;
741 
742 	ovs_flow_stats_get(flow, &stats, &used, &tcp_flags);
743 
744 	if (used &&
745 	    nla_put_u64_64bit(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used),
746 			      OVS_FLOW_ATTR_PAD))
747 		return -EMSGSIZE;
748 
749 	if (stats.n_packets &&
750 	    nla_put_64bit(skb, OVS_FLOW_ATTR_STATS,
751 			  sizeof(struct ovs_flow_stats), &stats,
752 			  OVS_FLOW_ATTR_PAD))
753 		return -EMSGSIZE;
754 
755 	if ((u8)ntohs(tcp_flags) &&
756 	     nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, (u8)ntohs(tcp_flags)))
757 		return -EMSGSIZE;
758 
759 	return 0;
760 }
761 
762 /* Called with ovs_mutex or RCU read lock. */
763 static int ovs_flow_cmd_fill_actions(const struct sw_flow *flow,
764 				     struct sk_buff *skb, int skb_orig_len)
765 {
766 	struct nlattr *start;
767 	int err;
768 
769 	/* If OVS_FLOW_ATTR_ACTIONS doesn't fit, skip dumping the actions if
770 	 * this is the first flow to be dumped into 'skb'.  This is unusual for
771 	 * Netlink but individual action lists can be longer than
772 	 * NLMSG_GOODSIZE and thus entirely undumpable if we didn't do this.
773 	 * The userspace caller can always fetch the actions separately if it
774 	 * really wants them.  (Most userspace callers in fact don't care.)
775 	 *
776 	 * This can only fail for dump operations because the skb is always
777 	 * properly sized for single flows.
778 	 */
779 	start = nla_nest_start(skb, OVS_FLOW_ATTR_ACTIONS);
780 	if (start) {
781 		const struct sw_flow_actions *sf_acts;
782 
783 		sf_acts = rcu_dereference_ovsl(flow->sf_acts);
784 		err = ovs_nla_put_actions(sf_acts->actions,
785 					  sf_acts->actions_len, skb);
786 
787 		if (!err)
788 			nla_nest_end(skb, start);
789 		else {
790 			if (skb_orig_len)
791 				return err;
792 
793 			nla_nest_cancel(skb, start);
794 		}
795 	} else if (skb_orig_len) {
796 		return -EMSGSIZE;
797 	}
798 
799 	return 0;
800 }
801 
802 /* Called with ovs_mutex or RCU read lock. */
803 static int ovs_flow_cmd_fill_info(const struct sw_flow *flow, int dp_ifindex,
804 				  struct sk_buff *skb, u32 portid,
805 				  u32 seq, u32 flags, u8 cmd, u32 ufid_flags)
806 {
807 	const int skb_orig_len = skb->len;
808 	struct ovs_header *ovs_header;
809 	int err;
810 
811 	ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family,
812 				 flags, cmd);
813 	if (!ovs_header)
814 		return -EMSGSIZE;
815 
816 	ovs_header->dp_ifindex = dp_ifindex;
817 
818 	err = ovs_nla_put_identifier(flow, skb);
819 	if (err)
820 		goto error;
821 
822 	if (should_fill_key(&flow->id, ufid_flags)) {
823 		err = ovs_nla_put_masked_key(flow, skb);
824 		if (err)
825 			goto error;
826 	}
827 
828 	if (should_fill_mask(ufid_flags)) {
829 		err = ovs_nla_put_mask(flow, skb);
830 		if (err)
831 			goto error;
832 	}
833 
834 	err = ovs_flow_cmd_fill_stats(flow, skb);
835 	if (err)
836 		goto error;
837 
838 	if (should_fill_actions(ufid_flags)) {
839 		err = ovs_flow_cmd_fill_actions(flow, skb, skb_orig_len);
840 		if (err)
841 			goto error;
842 	}
843 
844 	genlmsg_end(skb, ovs_header);
845 	return 0;
846 
847 error:
848 	genlmsg_cancel(skb, ovs_header);
849 	return err;
850 }
851 
852 /* May not be called with RCU read lock. */
853 static struct sk_buff *ovs_flow_cmd_alloc_info(const struct sw_flow_actions *acts,
854 					       const struct sw_flow_id *sfid,
855 					       struct genl_info *info,
856 					       bool always,
857 					       uint32_t ufid_flags)
858 {
859 	struct sk_buff *skb;
860 	size_t len;
861 
862 	if (!always && !ovs_must_notify(&dp_flow_genl_family, info, 0))
863 		return NULL;
864 
865 	len = ovs_flow_cmd_msg_size(acts, sfid, ufid_flags);
866 	skb = genlmsg_new(len, GFP_KERNEL);
867 	if (!skb)
868 		return ERR_PTR(-ENOMEM);
869 
870 	return skb;
871 }
872 
873 /* Called with ovs_mutex. */
874 static struct sk_buff *ovs_flow_cmd_build_info(const struct sw_flow *flow,
875 					       int dp_ifindex,
876 					       struct genl_info *info, u8 cmd,
877 					       bool always, u32 ufid_flags)
878 {
879 	struct sk_buff *skb;
880 	int retval;
881 
882 	skb = ovs_flow_cmd_alloc_info(ovsl_dereference(flow->sf_acts),
883 				      &flow->id, info, always, ufid_flags);
884 	if (IS_ERR_OR_NULL(skb))
885 		return skb;
886 
887 	retval = ovs_flow_cmd_fill_info(flow, dp_ifindex, skb,
888 					info->snd_portid, info->snd_seq, 0,
889 					cmd, ufid_flags);
890 	BUG_ON(retval < 0);
891 	return skb;
892 }
893 
894 static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
895 {
896 	struct net *net = sock_net(skb->sk);
897 	struct nlattr **a = info->attrs;
898 	struct ovs_header *ovs_header = info->userhdr;
899 	struct sw_flow *flow = NULL, *new_flow;
900 	struct sw_flow_mask mask;
901 	struct sk_buff *reply;
902 	struct datapath *dp;
903 	struct sw_flow_actions *acts;
904 	struct sw_flow_match match;
905 	u32 ufid_flags = ovs_nla_get_ufid_flags(a[OVS_FLOW_ATTR_UFID_FLAGS]);
906 	int error;
907 	bool log = !a[OVS_FLOW_ATTR_PROBE];
908 
909 	/* Must have key and actions. */
910 	error = -EINVAL;
911 	if (!a[OVS_FLOW_ATTR_KEY]) {
912 		OVS_NLERR(log, "Flow key attr not present in new flow.");
913 		goto error;
914 	}
915 	if (!a[OVS_FLOW_ATTR_ACTIONS]) {
916 		OVS_NLERR(log, "Flow actions attr not present in new flow.");
917 		goto error;
918 	}
919 
920 	/* Most of the time we need to allocate a new flow, do it before
921 	 * locking.
922 	 */
923 	new_flow = ovs_flow_alloc();
924 	if (IS_ERR(new_flow)) {
925 		error = PTR_ERR(new_flow);
926 		goto error;
927 	}
928 
929 	/* Extract key. */
930 	ovs_match_init(&match, &new_flow->key, false, &mask);
931 	error = ovs_nla_get_match(net, &match, a[OVS_FLOW_ATTR_KEY],
932 				  a[OVS_FLOW_ATTR_MASK], log);
933 	if (error)
934 		goto err_kfree_flow;
935 
936 	/* Extract flow identifier. */
937 	error = ovs_nla_get_identifier(&new_flow->id, a[OVS_FLOW_ATTR_UFID],
938 				       &new_flow->key, log);
939 	if (error)
940 		goto err_kfree_flow;
941 
942 	/* unmasked key is needed to match when ufid is not used. */
943 	if (ovs_identifier_is_key(&new_flow->id))
944 		match.key = new_flow->id.unmasked_key;
945 
946 	ovs_flow_mask_key(&new_flow->key, &new_flow->key, true, &mask);
947 
948 	/* Validate actions. */
949 	error = ovs_nla_copy_actions(net, a[OVS_FLOW_ATTR_ACTIONS],
950 				     &new_flow->key, &acts, log);
951 	if (error) {
952 		OVS_NLERR(log, "Flow actions may not be safe on all matching packets.");
953 		goto err_kfree_flow;
954 	}
955 
956 	reply = ovs_flow_cmd_alloc_info(acts, &new_flow->id, info, false,
957 					ufid_flags);
958 	if (IS_ERR(reply)) {
959 		error = PTR_ERR(reply);
960 		goto err_kfree_acts;
961 	}
962 
963 	ovs_lock();
964 	dp = get_dp(net, ovs_header->dp_ifindex);
965 	if (unlikely(!dp)) {
966 		error = -ENODEV;
967 		goto err_unlock_ovs;
968 	}
969 
970 	/* Check if this is a duplicate flow */
971 	if (ovs_identifier_is_ufid(&new_flow->id))
972 		flow = ovs_flow_tbl_lookup_ufid(&dp->table, &new_flow->id);
973 	if (!flow)
974 		flow = ovs_flow_tbl_lookup(&dp->table, &new_flow->key);
975 	if (likely(!flow)) {
976 		rcu_assign_pointer(new_flow->sf_acts, acts);
977 
978 		/* Put flow in bucket. */
979 		error = ovs_flow_tbl_insert(&dp->table, new_flow, &mask);
980 		if (unlikely(error)) {
981 			acts = NULL;
982 			goto err_unlock_ovs;
983 		}
984 
985 		if (unlikely(reply)) {
986 			error = ovs_flow_cmd_fill_info(new_flow,
987 						       ovs_header->dp_ifindex,
988 						       reply, info->snd_portid,
989 						       info->snd_seq, 0,
990 						       OVS_FLOW_CMD_NEW,
991 						       ufid_flags);
992 			BUG_ON(error < 0);
993 		}
994 		ovs_unlock();
995 	} else {
996 		struct sw_flow_actions *old_acts;
997 
998 		/* Bail out if we're not allowed to modify an existing flow.
999 		 * We accept NLM_F_CREATE in place of the intended NLM_F_EXCL
1000 		 * because Generic Netlink treats the latter as a dump
1001 		 * request.  We also accept NLM_F_EXCL in case that bug ever
1002 		 * gets fixed.
1003 		 */
1004 		if (unlikely(info->nlhdr->nlmsg_flags & (NLM_F_CREATE
1005 							 | NLM_F_EXCL))) {
1006 			error = -EEXIST;
1007 			goto err_unlock_ovs;
1008 		}
1009 		/* The flow identifier has to be the same for flow updates.
1010 		 * Look for any overlapping flow.
1011 		 */
1012 		if (unlikely(!ovs_flow_cmp(flow, &match))) {
1013 			if (ovs_identifier_is_key(&flow->id))
1014 				flow = ovs_flow_tbl_lookup_exact(&dp->table,
1015 								 &match);
1016 			else /* UFID matches but key is different */
1017 				flow = NULL;
1018 			if (!flow) {
1019 				error = -ENOENT;
1020 				goto err_unlock_ovs;
1021 			}
1022 		}
1023 		/* Update actions. */
1024 		old_acts = ovsl_dereference(flow->sf_acts);
1025 		rcu_assign_pointer(flow->sf_acts, acts);
1026 
1027 		if (unlikely(reply)) {
1028 			error = ovs_flow_cmd_fill_info(flow,
1029 						       ovs_header->dp_ifindex,
1030 						       reply, info->snd_portid,
1031 						       info->snd_seq, 0,
1032 						       OVS_FLOW_CMD_NEW,
1033 						       ufid_flags);
1034 			BUG_ON(error < 0);
1035 		}
1036 		ovs_unlock();
1037 
1038 		ovs_nla_free_flow_actions_rcu(old_acts);
1039 		ovs_flow_free(new_flow, false);
1040 	}
1041 
1042 	if (reply)
1043 		ovs_notify(&dp_flow_genl_family, reply, info);
1044 	return 0;
1045 
1046 err_unlock_ovs:
1047 	ovs_unlock();
1048 	kfree_skb(reply);
1049 err_kfree_acts:
1050 	ovs_nla_free_flow_actions(acts);
1051 err_kfree_flow:
1052 	ovs_flow_free(new_flow, false);
1053 error:
1054 	return error;
1055 }
1056 
1057 /* Factor out action copy to avoid "Wframe-larger-than=1024" warning. */
1058 static struct sw_flow_actions *get_flow_actions(struct net *net,
1059 						const struct nlattr *a,
1060 						const struct sw_flow_key *key,
1061 						const struct sw_flow_mask *mask,
1062 						bool log)
1063 {
1064 	struct sw_flow_actions *acts;
1065 	struct sw_flow_key masked_key;
1066 	int error;
1067 
1068 	ovs_flow_mask_key(&masked_key, key, true, mask);
1069 	error = ovs_nla_copy_actions(net, a, &masked_key, &acts, log);
1070 	if (error) {
1071 		OVS_NLERR(log,
1072 			  "Actions may not be safe on all matching packets");
1073 		return ERR_PTR(error);
1074 	}
1075 
1076 	return acts;
1077 }
1078 
1079 /* Factor out match-init and action-copy to avoid
1080  * "Wframe-larger-than=1024" warning. Because mask is only
1081  * used to get actions, we new a function to save some
1082  * stack space.
1083  *
1084  * If there are not key and action attrs, we return 0
1085  * directly. In the case, the caller will also not use the
1086  * match as before. If there is action attr, we try to get
1087  * actions and save them to *acts. Before returning from
1088  * the function, we reset the match->mask pointer. Because
1089  * we should not to return match object with dangling reference
1090  * to mask.
1091  * */
1092 static int ovs_nla_init_match_and_action(struct net *net,
1093 					 struct sw_flow_match *match,
1094 					 struct sw_flow_key *key,
1095 					 struct nlattr **a,
1096 					 struct sw_flow_actions **acts,
1097 					 bool log)
1098 {
1099 	struct sw_flow_mask mask;
1100 	int error = 0;
1101 
1102 	if (a[OVS_FLOW_ATTR_KEY]) {
1103 		ovs_match_init(match, key, true, &mask);
1104 		error = ovs_nla_get_match(net, match, a[OVS_FLOW_ATTR_KEY],
1105 					  a[OVS_FLOW_ATTR_MASK], log);
1106 		if (error)
1107 			goto error;
1108 	}
1109 
1110 	if (a[OVS_FLOW_ATTR_ACTIONS]) {
1111 		if (!a[OVS_FLOW_ATTR_KEY]) {
1112 			OVS_NLERR(log,
1113 				  "Flow key attribute not present in set flow.");
1114 			return -EINVAL;
1115 		}
1116 
1117 		*acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], key,
1118 					 &mask, log);
1119 		if (IS_ERR(*acts)) {
1120 			error = PTR_ERR(*acts);
1121 			goto error;
1122 		}
1123 	}
1124 
1125 	/* On success, error is 0. */
1126 error:
1127 	match->mask = NULL;
1128 	return error;
1129 }
1130 
1131 static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
1132 {
1133 	struct net *net = sock_net(skb->sk);
1134 	struct nlattr **a = info->attrs;
1135 	struct ovs_header *ovs_header = info->userhdr;
1136 	struct sw_flow_key key;
1137 	struct sw_flow *flow;
1138 	struct sk_buff *reply = NULL;
1139 	struct datapath *dp;
1140 	struct sw_flow_actions *old_acts = NULL, *acts = NULL;
1141 	struct sw_flow_match match;
1142 	struct sw_flow_id sfid;
1143 	u32 ufid_flags = ovs_nla_get_ufid_flags(a[OVS_FLOW_ATTR_UFID_FLAGS]);
1144 	int error = 0;
1145 	bool log = !a[OVS_FLOW_ATTR_PROBE];
1146 	bool ufid_present;
1147 
1148 	ufid_present = ovs_nla_get_ufid(&sfid, a[OVS_FLOW_ATTR_UFID], log);
1149 	if (!a[OVS_FLOW_ATTR_KEY] && !ufid_present) {
1150 		OVS_NLERR(log,
1151 			  "Flow set message rejected, Key attribute missing.");
1152 		return -EINVAL;
1153 	}
1154 
1155 	error = ovs_nla_init_match_and_action(net, &match, &key, a,
1156 					      &acts, log);
1157 	if (error)
1158 		goto error;
1159 
1160 	if (acts) {
1161 		/* Can allocate before locking if have acts. */
1162 		reply = ovs_flow_cmd_alloc_info(acts, &sfid, info, false,
1163 						ufid_flags);
1164 		if (IS_ERR(reply)) {
1165 			error = PTR_ERR(reply);
1166 			goto err_kfree_acts;
1167 		}
1168 	}
1169 
1170 	ovs_lock();
1171 	dp = get_dp(net, ovs_header->dp_ifindex);
1172 	if (unlikely(!dp)) {
1173 		error = -ENODEV;
1174 		goto err_unlock_ovs;
1175 	}
1176 	/* Check that the flow exists. */
1177 	if (ufid_present)
1178 		flow = ovs_flow_tbl_lookup_ufid(&dp->table, &sfid);
1179 	else
1180 		flow = ovs_flow_tbl_lookup_exact(&dp->table, &match);
1181 	if (unlikely(!flow)) {
1182 		error = -ENOENT;
1183 		goto err_unlock_ovs;
1184 	}
1185 
1186 	/* Update actions, if present. */
1187 	if (likely(acts)) {
1188 		old_acts = ovsl_dereference(flow->sf_acts);
1189 		rcu_assign_pointer(flow->sf_acts, acts);
1190 
1191 		if (unlikely(reply)) {
1192 			error = ovs_flow_cmd_fill_info(flow,
1193 						       ovs_header->dp_ifindex,
1194 						       reply, info->snd_portid,
1195 						       info->snd_seq, 0,
1196 						       OVS_FLOW_CMD_NEW,
1197 						       ufid_flags);
1198 			BUG_ON(error < 0);
1199 		}
1200 	} else {
1201 		/* Could not alloc without acts before locking. */
1202 		reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
1203 						info, OVS_FLOW_CMD_NEW, false,
1204 						ufid_flags);
1205 
1206 		if (IS_ERR(reply)) {
1207 			error = PTR_ERR(reply);
1208 			goto err_unlock_ovs;
1209 		}
1210 	}
1211 
1212 	/* Clear stats. */
1213 	if (a[OVS_FLOW_ATTR_CLEAR])
1214 		ovs_flow_stats_clear(flow);
1215 	ovs_unlock();
1216 
1217 	if (reply)
1218 		ovs_notify(&dp_flow_genl_family, reply, info);
1219 	if (old_acts)
1220 		ovs_nla_free_flow_actions_rcu(old_acts);
1221 
1222 	return 0;
1223 
1224 err_unlock_ovs:
1225 	ovs_unlock();
1226 	kfree_skb(reply);
1227 err_kfree_acts:
1228 	ovs_nla_free_flow_actions(acts);
1229 error:
1230 	return error;
1231 }
1232 
1233 static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
1234 {
1235 	struct nlattr **a = info->attrs;
1236 	struct ovs_header *ovs_header = info->userhdr;
1237 	struct net *net = sock_net(skb->sk);
1238 	struct sw_flow_key key;
1239 	struct sk_buff *reply;
1240 	struct sw_flow *flow;
1241 	struct datapath *dp;
1242 	struct sw_flow_match match;
1243 	struct sw_flow_id ufid;
1244 	u32 ufid_flags = ovs_nla_get_ufid_flags(a[OVS_FLOW_ATTR_UFID_FLAGS]);
1245 	int err = 0;
1246 	bool log = !a[OVS_FLOW_ATTR_PROBE];
1247 	bool ufid_present;
1248 
1249 	ufid_present = ovs_nla_get_ufid(&ufid, a[OVS_FLOW_ATTR_UFID], log);
1250 	if (a[OVS_FLOW_ATTR_KEY]) {
1251 		ovs_match_init(&match, &key, true, NULL);
1252 		err = ovs_nla_get_match(net, &match, a[OVS_FLOW_ATTR_KEY], NULL,
1253 					log);
1254 	} else if (!ufid_present) {
1255 		OVS_NLERR(log,
1256 			  "Flow get message rejected, Key attribute missing.");
1257 		err = -EINVAL;
1258 	}
1259 	if (err)
1260 		return err;
1261 
1262 	ovs_lock();
1263 	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
1264 	if (!dp) {
1265 		err = -ENODEV;
1266 		goto unlock;
1267 	}
1268 
1269 	if (ufid_present)
1270 		flow = ovs_flow_tbl_lookup_ufid(&dp->table, &ufid);
1271 	else
1272 		flow = ovs_flow_tbl_lookup_exact(&dp->table, &match);
1273 	if (!flow) {
1274 		err = -ENOENT;
1275 		goto unlock;
1276 	}
1277 
1278 	reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex, info,
1279 					OVS_FLOW_CMD_NEW, true, ufid_flags);
1280 	if (IS_ERR(reply)) {
1281 		err = PTR_ERR(reply);
1282 		goto unlock;
1283 	}
1284 
1285 	ovs_unlock();
1286 	return genlmsg_reply(reply, info);
1287 unlock:
1288 	ovs_unlock();
1289 	return err;
1290 }
1291 
1292 static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info)
1293 {
1294 	struct nlattr **a = info->attrs;
1295 	struct ovs_header *ovs_header = info->userhdr;
1296 	struct net *net = sock_net(skb->sk);
1297 	struct sw_flow_key key;
1298 	struct sk_buff *reply;
1299 	struct sw_flow *flow = NULL;
1300 	struct datapath *dp;
1301 	struct sw_flow_match match;
1302 	struct sw_flow_id ufid;
1303 	u32 ufid_flags = ovs_nla_get_ufid_flags(a[OVS_FLOW_ATTR_UFID_FLAGS]);
1304 	int err;
1305 	bool log = !a[OVS_FLOW_ATTR_PROBE];
1306 	bool ufid_present;
1307 
1308 	ufid_present = ovs_nla_get_ufid(&ufid, a[OVS_FLOW_ATTR_UFID], log);
1309 	if (a[OVS_FLOW_ATTR_KEY]) {
1310 		ovs_match_init(&match, &key, true, NULL);
1311 		err = ovs_nla_get_match(net, &match, a[OVS_FLOW_ATTR_KEY],
1312 					NULL, log);
1313 		if (unlikely(err))
1314 			return err;
1315 	}
1316 
1317 	ovs_lock();
1318 	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
1319 	if (unlikely(!dp)) {
1320 		err = -ENODEV;
1321 		goto unlock;
1322 	}
1323 
1324 	if (unlikely(!a[OVS_FLOW_ATTR_KEY] && !ufid_present)) {
1325 		err = ovs_flow_tbl_flush(&dp->table);
1326 		goto unlock;
1327 	}
1328 
1329 	if (ufid_present)
1330 		flow = ovs_flow_tbl_lookup_ufid(&dp->table, &ufid);
1331 	else
1332 		flow = ovs_flow_tbl_lookup_exact(&dp->table, &match);
1333 	if (unlikely(!flow)) {
1334 		err = -ENOENT;
1335 		goto unlock;
1336 	}
1337 
1338 	ovs_flow_tbl_remove(&dp->table, flow);
1339 	ovs_unlock();
1340 
1341 	reply = ovs_flow_cmd_alloc_info((const struct sw_flow_actions __force *) flow->sf_acts,
1342 					&flow->id, info, false, ufid_flags);
1343 	if (likely(reply)) {
1344 		if (likely(!IS_ERR(reply))) {
1345 			rcu_read_lock();	/*To keep RCU checker happy. */
1346 			err = ovs_flow_cmd_fill_info(flow, ovs_header->dp_ifindex,
1347 						     reply, info->snd_portid,
1348 						     info->snd_seq, 0,
1349 						     OVS_FLOW_CMD_DEL,
1350 						     ufid_flags);
1351 			rcu_read_unlock();
1352 			BUG_ON(err < 0);
1353 
1354 			ovs_notify(&dp_flow_genl_family, reply, info);
1355 		} else {
1356 			netlink_set_err(sock_net(skb->sk)->genl_sock, 0, 0, PTR_ERR(reply));
1357 		}
1358 	}
1359 
1360 	ovs_flow_free(flow, true);
1361 	return 0;
1362 unlock:
1363 	ovs_unlock();
1364 	return err;
1365 }
1366 
1367 static int ovs_flow_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
1368 {
1369 	struct nlattr *a[__OVS_FLOW_ATTR_MAX];
1370 	struct ovs_header *ovs_header = genlmsg_data(nlmsg_data(cb->nlh));
1371 	struct table_instance *ti;
1372 	struct datapath *dp;
1373 	u32 ufid_flags;
1374 	int err;
1375 
1376 	err = genlmsg_parse(cb->nlh, &dp_flow_genl_family, a,
1377 			    OVS_FLOW_ATTR_MAX, flow_policy, NULL);
1378 	if (err)
1379 		return err;
1380 	ufid_flags = ovs_nla_get_ufid_flags(a[OVS_FLOW_ATTR_UFID_FLAGS]);
1381 
1382 	rcu_read_lock();
1383 	dp = get_dp_rcu(sock_net(skb->sk), ovs_header->dp_ifindex);
1384 	if (!dp) {
1385 		rcu_read_unlock();
1386 		return -ENODEV;
1387 	}
1388 
1389 	ti = rcu_dereference(dp->table.ti);
1390 	for (;;) {
1391 		struct sw_flow *flow;
1392 		u32 bucket, obj;
1393 
1394 		bucket = cb->args[0];
1395 		obj = cb->args[1];
1396 		flow = ovs_flow_tbl_dump_next(ti, &bucket, &obj);
1397 		if (!flow)
1398 			break;
1399 
1400 		if (ovs_flow_cmd_fill_info(flow, ovs_header->dp_ifindex, skb,
1401 					   NETLINK_CB(cb->skb).portid,
1402 					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
1403 					   OVS_FLOW_CMD_NEW, ufid_flags) < 0)
1404 			break;
1405 
1406 		cb->args[0] = bucket;
1407 		cb->args[1] = obj;
1408 	}
1409 	rcu_read_unlock();
1410 	return skb->len;
1411 }
1412 
1413 static const struct nla_policy flow_policy[OVS_FLOW_ATTR_MAX + 1] = {
1414 	[OVS_FLOW_ATTR_KEY] = { .type = NLA_NESTED },
1415 	[OVS_FLOW_ATTR_MASK] = { .type = NLA_NESTED },
1416 	[OVS_FLOW_ATTR_ACTIONS] = { .type = NLA_NESTED },
1417 	[OVS_FLOW_ATTR_CLEAR] = { .type = NLA_FLAG },
1418 	[OVS_FLOW_ATTR_PROBE] = { .type = NLA_FLAG },
1419 	[OVS_FLOW_ATTR_UFID] = { .type = NLA_UNSPEC, .len = 1 },
1420 	[OVS_FLOW_ATTR_UFID_FLAGS] = { .type = NLA_U32 },
1421 };
1422 
1423 static const struct genl_ops dp_flow_genl_ops[] = {
1424 	{ .cmd = OVS_FLOW_CMD_NEW,
1425 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
1426 	  .policy = flow_policy,
1427 	  .doit = ovs_flow_cmd_new
1428 	},
1429 	{ .cmd = OVS_FLOW_CMD_DEL,
1430 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
1431 	  .policy = flow_policy,
1432 	  .doit = ovs_flow_cmd_del
1433 	},
1434 	{ .cmd = OVS_FLOW_CMD_GET,
1435 	  .flags = 0,		    /* OK for unprivileged users. */
1436 	  .policy = flow_policy,
1437 	  .doit = ovs_flow_cmd_get,
1438 	  .dumpit = ovs_flow_cmd_dump
1439 	},
1440 	{ .cmd = OVS_FLOW_CMD_SET,
1441 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
1442 	  .policy = flow_policy,
1443 	  .doit = ovs_flow_cmd_set,
1444 	},
1445 };
1446 
1447 static struct genl_family dp_flow_genl_family __ro_after_init = {
1448 	.hdrsize = sizeof(struct ovs_header),
1449 	.name = OVS_FLOW_FAMILY,
1450 	.version = OVS_FLOW_VERSION,
1451 	.maxattr = OVS_FLOW_ATTR_MAX,
1452 	.netnsok = true,
1453 	.parallel_ops = true,
1454 	.ops = dp_flow_genl_ops,
1455 	.n_ops = ARRAY_SIZE(dp_flow_genl_ops),
1456 	.mcgrps = &ovs_dp_flow_multicast_group,
1457 	.n_mcgrps = 1,
1458 	.module = THIS_MODULE,
1459 };
1460 
1461 static size_t ovs_dp_cmd_msg_size(void)
1462 {
1463 	size_t msgsize = NLMSG_ALIGN(sizeof(struct ovs_header));
1464 
1465 	msgsize += nla_total_size(IFNAMSIZ);
1466 	msgsize += nla_total_size_64bit(sizeof(struct ovs_dp_stats));
1467 	msgsize += nla_total_size_64bit(sizeof(struct ovs_dp_megaflow_stats));
1468 	msgsize += nla_total_size(sizeof(u32)); /* OVS_DP_ATTR_USER_FEATURES */
1469 
1470 	return msgsize;
1471 }
1472 
1473 /* Called with ovs_mutex. */
1474 static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
1475 				u32 portid, u32 seq, u32 flags, u8 cmd)
1476 {
1477 	struct ovs_header *ovs_header;
1478 	struct ovs_dp_stats dp_stats;
1479 	struct ovs_dp_megaflow_stats dp_megaflow_stats;
1480 	int err;
1481 
1482 	ovs_header = genlmsg_put(skb, portid, seq, &dp_datapath_genl_family,
1483 				   flags, cmd);
1484 	if (!ovs_header)
1485 		goto error;
1486 
1487 	ovs_header->dp_ifindex = get_dpifindex(dp);
1488 
1489 	err = nla_put_string(skb, OVS_DP_ATTR_NAME, ovs_dp_name(dp));
1490 	if (err)
1491 		goto nla_put_failure;
1492 
1493 	get_dp_stats(dp, &dp_stats, &dp_megaflow_stats);
1494 	if (nla_put_64bit(skb, OVS_DP_ATTR_STATS, sizeof(struct ovs_dp_stats),
1495 			  &dp_stats, OVS_DP_ATTR_PAD))
1496 		goto nla_put_failure;
1497 
1498 	if (nla_put_64bit(skb, OVS_DP_ATTR_MEGAFLOW_STATS,
1499 			  sizeof(struct ovs_dp_megaflow_stats),
1500 			  &dp_megaflow_stats, OVS_DP_ATTR_PAD))
1501 		goto nla_put_failure;
1502 
1503 	if (nla_put_u32(skb, OVS_DP_ATTR_USER_FEATURES, dp->user_features))
1504 		goto nla_put_failure;
1505 
1506 	genlmsg_end(skb, ovs_header);
1507 	return 0;
1508 
1509 nla_put_failure:
1510 	genlmsg_cancel(skb, ovs_header);
1511 error:
1512 	return -EMSGSIZE;
1513 }
1514 
1515 static struct sk_buff *ovs_dp_cmd_alloc_info(void)
1516 {
1517 	return genlmsg_new(ovs_dp_cmd_msg_size(), GFP_KERNEL);
1518 }
1519 
1520 /* Called with rcu_read_lock or ovs_mutex. */
1521 static struct datapath *lookup_datapath(struct net *net,
1522 					const struct ovs_header *ovs_header,
1523 					struct nlattr *a[OVS_DP_ATTR_MAX + 1])
1524 {
1525 	struct datapath *dp;
1526 
1527 	if (!a[OVS_DP_ATTR_NAME])
1528 		dp = get_dp(net, ovs_header->dp_ifindex);
1529 	else {
1530 		struct vport *vport;
1531 
1532 		vport = ovs_vport_locate(net, nla_data(a[OVS_DP_ATTR_NAME]));
1533 		dp = vport && vport->port_no == OVSP_LOCAL ? vport->dp : NULL;
1534 	}
1535 	return dp ? dp : ERR_PTR(-ENODEV);
1536 }
1537 
1538 static void ovs_dp_reset_user_features(struct sk_buff *skb, struct genl_info *info)
1539 {
1540 	struct datapath *dp;
1541 
1542 	dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
1543 	if (IS_ERR(dp))
1544 		return;
1545 
1546 	WARN(dp->user_features, "Dropping previously announced user features\n");
1547 	dp->user_features = 0;
1548 }
1549 
1550 static void ovs_dp_change(struct datapath *dp, struct nlattr *a[])
1551 {
1552 	if (a[OVS_DP_ATTR_USER_FEATURES])
1553 		dp->user_features = nla_get_u32(a[OVS_DP_ATTR_USER_FEATURES]);
1554 }
1555 
1556 static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
1557 {
1558 	struct nlattr **a = info->attrs;
1559 	struct vport_parms parms;
1560 	struct sk_buff *reply;
1561 	struct datapath *dp;
1562 	struct vport *vport;
1563 	struct ovs_net *ovs_net;
1564 	int err, i;
1565 
1566 	err = -EINVAL;
1567 	if (!a[OVS_DP_ATTR_NAME] || !a[OVS_DP_ATTR_UPCALL_PID])
1568 		goto err;
1569 
1570 	reply = ovs_dp_cmd_alloc_info();
1571 	if (!reply)
1572 		return -ENOMEM;
1573 
1574 	err = -ENOMEM;
1575 	dp = kzalloc(sizeof(*dp), GFP_KERNEL);
1576 	if (dp == NULL)
1577 		goto err_free_reply;
1578 
1579 	ovs_dp_set_net(dp, sock_net(skb->sk));
1580 
1581 	/* Allocate table. */
1582 	err = ovs_flow_tbl_init(&dp->table);
1583 	if (err)
1584 		goto err_free_dp;
1585 
1586 	dp->stats_percpu = netdev_alloc_pcpu_stats(struct dp_stats_percpu);
1587 	if (!dp->stats_percpu) {
1588 		err = -ENOMEM;
1589 		goto err_destroy_table;
1590 	}
1591 
1592 	dp->ports = kmalloc(DP_VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
1593 			    GFP_KERNEL);
1594 	if (!dp->ports) {
1595 		err = -ENOMEM;
1596 		goto err_destroy_percpu;
1597 	}
1598 
1599 	for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++)
1600 		INIT_HLIST_HEAD(&dp->ports[i]);
1601 
1602 	/* Set up our datapath device. */
1603 	parms.name = nla_data(a[OVS_DP_ATTR_NAME]);
1604 	parms.type = OVS_VPORT_TYPE_INTERNAL;
1605 	parms.options = NULL;
1606 	parms.dp = dp;
1607 	parms.port_no = OVSP_LOCAL;
1608 	parms.upcall_portids = a[OVS_DP_ATTR_UPCALL_PID];
1609 
1610 	ovs_dp_change(dp, a);
1611 
1612 	/* So far only local changes have been made, now need the lock. */
1613 	ovs_lock();
1614 
1615 	vport = new_vport(&parms);
1616 	if (IS_ERR(vport)) {
1617 		err = PTR_ERR(vport);
1618 		if (err == -EBUSY)
1619 			err = -EEXIST;
1620 
1621 		if (err == -EEXIST) {
1622 			/* An outdated user space instance that does not understand
1623 			 * the concept of user_features has attempted to create a new
1624 			 * datapath and is likely to reuse it. Drop all user features.
1625 			 */
1626 			if (info->genlhdr->version < OVS_DP_VER_FEATURES)
1627 				ovs_dp_reset_user_features(skb, info);
1628 		}
1629 
1630 		goto err_destroy_ports_array;
1631 	}
1632 
1633 	err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
1634 				   info->snd_seq, 0, OVS_DP_CMD_NEW);
1635 	BUG_ON(err < 0);
1636 
1637 	ovs_net = net_generic(ovs_dp_get_net(dp), ovs_net_id);
1638 	list_add_tail_rcu(&dp->list_node, &ovs_net->dps);
1639 
1640 	ovs_unlock();
1641 
1642 	ovs_notify(&dp_datapath_genl_family, reply, info);
1643 	return 0;
1644 
1645 err_destroy_ports_array:
1646 	ovs_unlock();
1647 	kfree(dp->ports);
1648 err_destroy_percpu:
1649 	free_percpu(dp->stats_percpu);
1650 err_destroy_table:
1651 	ovs_flow_tbl_destroy(&dp->table);
1652 err_free_dp:
1653 	kfree(dp);
1654 err_free_reply:
1655 	kfree_skb(reply);
1656 err:
1657 	return err;
1658 }
1659 
1660 /* Called with ovs_mutex. */
1661 static void __dp_destroy(struct datapath *dp)
1662 {
1663 	int i;
1664 
1665 	for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++) {
1666 		struct vport *vport;
1667 		struct hlist_node *n;
1668 
1669 		hlist_for_each_entry_safe(vport, n, &dp->ports[i], dp_hash_node)
1670 			if (vport->port_no != OVSP_LOCAL)
1671 				ovs_dp_detach_port(vport);
1672 	}
1673 
1674 	list_del_rcu(&dp->list_node);
1675 
1676 	/* OVSP_LOCAL is datapath internal port. We need to make sure that
1677 	 * all ports in datapath are destroyed first before freeing datapath.
1678 	 */
1679 	ovs_dp_detach_port(ovs_vport_ovsl(dp, OVSP_LOCAL));
1680 
1681 	/* RCU destroy the flow table */
1682 	call_rcu(&dp->rcu, destroy_dp_rcu);
1683 }
1684 
1685 static int ovs_dp_cmd_del(struct sk_buff *skb, struct genl_info *info)
1686 {
1687 	struct sk_buff *reply;
1688 	struct datapath *dp;
1689 	int err;
1690 
1691 	reply = ovs_dp_cmd_alloc_info();
1692 	if (!reply)
1693 		return -ENOMEM;
1694 
1695 	ovs_lock();
1696 	dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
1697 	err = PTR_ERR(dp);
1698 	if (IS_ERR(dp))
1699 		goto err_unlock_free;
1700 
1701 	err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
1702 				   info->snd_seq, 0, OVS_DP_CMD_DEL);
1703 	BUG_ON(err < 0);
1704 
1705 	__dp_destroy(dp);
1706 	ovs_unlock();
1707 
1708 	ovs_notify(&dp_datapath_genl_family, reply, info);
1709 
1710 	return 0;
1711 
1712 err_unlock_free:
1713 	ovs_unlock();
1714 	kfree_skb(reply);
1715 	return err;
1716 }
1717 
1718 static int ovs_dp_cmd_set(struct sk_buff *skb, struct genl_info *info)
1719 {
1720 	struct sk_buff *reply;
1721 	struct datapath *dp;
1722 	int err;
1723 
1724 	reply = ovs_dp_cmd_alloc_info();
1725 	if (!reply)
1726 		return -ENOMEM;
1727 
1728 	ovs_lock();
1729 	dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
1730 	err = PTR_ERR(dp);
1731 	if (IS_ERR(dp))
1732 		goto err_unlock_free;
1733 
1734 	ovs_dp_change(dp, info->attrs);
1735 
1736 	err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
1737 				   info->snd_seq, 0, OVS_DP_CMD_NEW);
1738 	BUG_ON(err < 0);
1739 
1740 	ovs_unlock();
1741 	ovs_notify(&dp_datapath_genl_family, reply, info);
1742 
1743 	return 0;
1744 
1745 err_unlock_free:
1746 	ovs_unlock();
1747 	kfree_skb(reply);
1748 	return err;
1749 }
1750 
1751 static int ovs_dp_cmd_get(struct sk_buff *skb, struct genl_info *info)
1752 {
1753 	struct sk_buff *reply;
1754 	struct datapath *dp;
1755 	int err;
1756 
1757 	reply = ovs_dp_cmd_alloc_info();
1758 	if (!reply)
1759 		return -ENOMEM;
1760 
1761 	ovs_lock();
1762 	dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
1763 	if (IS_ERR(dp)) {
1764 		err = PTR_ERR(dp);
1765 		goto err_unlock_free;
1766 	}
1767 	err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
1768 				   info->snd_seq, 0, OVS_DP_CMD_NEW);
1769 	BUG_ON(err < 0);
1770 	ovs_unlock();
1771 
1772 	return genlmsg_reply(reply, info);
1773 
1774 err_unlock_free:
1775 	ovs_unlock();
1776 	kfree_skb(reply);
1777 	return err;
1778 }
1779 
1780 static int ovs_dp_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
1781 {
1782 	struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
1783 	struct datapath *dp;
1784 	int skip = cb->args[0];
1785 	int i = 0;
1786 
1787 	ovs_lock();
1788 	list_for_each_entry(dp, &ovs_net->dps, list_node) {
1789 		if (i >= skip &&
1790 		    ovs_dp_cmd_fill_info(dp, skb, NETLINK_CB(cb->skb).portid,
1791 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
1792 					 OVS_DP_CMD_NEW) < 0)
1793 			break;
1794 		i++;
1795 	}
1796 	ovs_unlock();
1797 
1798 	cb->args[0] = i;
1799 
1800 	return skb->len;
1801 }
1802 
1803 static const struct nla_policy datapath_policy[OVS_DP_ATTR_MAX + 1] = {
1804 	[OVS_DP_ATTR_NAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
1805 	[OVS_DP_ATTR_UPCALL_PID] = { .type = NLA_U32 },
1806 	[OVS_DP_ATTR_USER_FEATURES] = { .type = NLA_U32 },
1807 };
1808 
1809 static const struct genl_ops dp_datapath_genl_ops[] = {
1810 	{ .cmd = OVS_DP_CMD_NEW,
1811 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
1812 	  .policy = datapath_policy,
1813 	  .doit = ovs_dp_cmd_new
1814 	},
1815 	{ .cmd = OVS_DP_CMD_DEL,
1816 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
1817 	  .policy = datapath_policy,
1818 	  .doit = ovs_dp_cmd_del
1819 	},
1820 	{ .cmd = OVS_DP_CMD_GET,
1821 	  .flags = 0,		    /* OK for unprivileged users. */
1822 	  .policy = datapath_policy,
1823 	  .doit = ovs_dp_cmd_get,
1824 	  .dumpit = ovs_dp_cmd_dump
1825 	},
1826 	{ .cmd = OVS_DP_CMD_SET,
1827 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
1828 	  .policy = datapath_policy,
1829 	  .doit = ovs_dp_cmd_set,
1830 	},
1831 };
1832 
1833 static struct genl_family dp_datapath_genl_family __ro_after_init = {
1834 	.hdrsize = sizeof(struct ovs_header),
1835 	.name = OVS_DATAPATH_FAMILY,
1836 	.version = OVS_DATAPATH_VERSION,
1837 	.maxattr = OVS_DP_ATTR_MAX,
1838 	.netnsok = true,
1839 	.parallel_ops = true,
1840 	.ops = dp_datapath_genl_ops,
1841 	.n_ops = ARRAY_SIZE(dp_datapath_genl_ops),
1842 	.mcgrps = &ovs_dp_datapath_multicast_group,
1843 	.n_mcgrps = 1,
1844 	.module = THIS_MODULE,
1845 };
1846 
1847 /* Called with ovs_mutex or RCU read lock. */
1848 static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb,
1849 				   u32 portid, u32 seq, u32 flags, u8 cmd)
1850 {
1851 	struct ovs_header *ovs_header;
1852 	struct ovs_vport_stats vport_stats;
1853 	int err;
1854 
1855 	ovs_header = genlmsg_put(skb, portid, seq, &dp_vport_genl_family,
1856 				 flags, cmd);
1857 	if (!ovs_header)
1858 		return -EMSGSIZE;
1859 
1860 	ovs_header->dp_ifindex = get_dpifindex(vport->dp);
1861 
1862 	if (nla_put_u32(skb, OVS_VPORT_ATTR_PORT_NO, vport->port_no) ||
1863 	    nla_put_u32(skb, OVS_VPORT_ATTR_TYPE, vport->ops->type) ||
1864 	    nla_put_string(skb, OVS_VPORT_ATTR_NAME,
1865 			   ovs_vport_name(vport)))
1866 		goto nla_put_failure;
1867 
1868 	ovs_vport_get_stats(vport, &vport_stats);
1869 	if (nla_put_64bit(skb, OVS_VPORT_ATTR_STATS,
1870 			  sizeof(struct ovs_vport_stats), &vport_stats,
1871 			  OVS_VPORT_ATTR_PAD))
1872 		goto nla_put_failure;
1873 
1874 	if (ovs_vport_get_upcall_portids(vport, skb))
1875 		goto nla_put_failure;
1876 
1877 	err = ovs_vport_get_options(vport, skb);
1878 	if (err == -EMSGSIZE)
1879 		goto error;
1880 
1881 	genlmsg_end(skb, ovs_header);
1882 	return 0;
1883 
1884 nla_put_failure:
1885 	err = -EMSGSIZE;
1886 error:
1887 	genlmsg_cancel(skb, ovs_header);
1888 	return err;
1889 }
1890 
1891 static struct sk_buff *ovs_vport_cmd_alloc_info(void)
1892 {
1893 	return nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1894 }
1895 
1896 /* Called with ovs_mutex, only via ovs_dp_notify_wq(). */
1897 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, u32 portid,
1898 					 u32 seq, u8 cmd)
1899 {
1900 	struct sk_buff *skb;
1901 	int retval;
1902 
1903 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1904 	if (!skb)
1905 		return ERR_PTR(-ENOMEM);
1906 
1907 	retval = ovs_vport_cmd_fill_info(vport, skb, portid, seq, 0, cmd);
1908 	BUG_ON(retval < 0);
1909 
1910 	return skb;
1911 }
1912 
1913 /* Called with ovs_mutex or RCU read lock. */
1914 static struct vport *lookup_vport(struct net *net,
1915 				  const struct ovs_header *ovs_header,
1916 				  struct nlattr *a[OVS_VPORT_ATTR_MAX + 1])
1917 {
1918 	struct datapath *dp;
1919 	struct vport *vport;
1920 
1921 	if (a[OVS_VPORT_ATTR_NAME]) {
1922 		vport = ovs_vport_locate(net, nla_data(a[OVS_VPORT_ATTR_NAME]));
1923 		if (!vport)
1924 			return ERR_PTR(-ENODEV);
1925 		if (ovs_header->dp_ifindex &&
1926 		    ovs_header->dp_ifindex != get_dpifindex(vport->dp))
1927 			return ERR_PTR(-ENODEV);
1928 		return vport;
1929 	} else if (a[OVS_VPORT_ATTR_PORT_NO]) {
1930 		u32 port_no = nla_get_u32(a[OVS_VPORT_ATTR_PORT_NO]);
1931 
1932 		if (port_no >= DP_MAX_PORTS)
1933 			return ERR_PTR(-EFBIG);
1934 
1935 		dp = get_dp(net, ovs_header->dp_ifindex);
1936 		if (!dp)
1937 			return ERR_PTR(-ENODEV);
1938 
1939 		vport = ovs_vport_ovsl_rcu(dp, port_no);
1940 		if (!vport)
1941 			return ERR_PTR(-ENODEV);
1942 		return vport;
1943 	} else
1944 		return ERR_PTR(-EINVAL);
1945 }
1946 
1947 /* Called with ovs_mutex */
1948 static void update_headroom(struct datapath *dp)
1949 {
1950 	unsigned dev_headroom, max_headroom = 0;
1951 	struct net_device *dev;
1952 	struct vport *vport;
1953 	int i;
1954 
1955 	for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++) {
1956 		hlist_for_each_entry_rcu(vport, &dp->ports[i], dp_hash_node) {
1957 			dev = vport->dev;
1958 			dev_headroom = netdev_get_fwd_headroom(dev);
1959 			if (dev_headroom > max_headroom)
1960 				max_headroom = dev_headroom;
1961 		}
1962 	}
1963 
1964 	dp->max_headroom = max_headroom;
1965 	for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++)
1966 		hlist_for_each_entry_rcu(vport, &dp->ports[i], dp_hash_node)
1967 			netdev_set_rx_headroom(vport->dev, max_headroom);
1968 }
1969 
1970 static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
1971 {
1972 	struct nlattr **a = info->attrs;
1973 	struct ovs_header *ovs_header = info->userhdr;
1974 	struct vport_parms parms;
1975 	struct sk_buff *reply;
1976 	struct vport *vport;
1977 	struct datapath *dp;
1978 	u32 port_no;
1979 	int err;
1980 
1981 	if (!a[OVS_VPORT_ATTR_NAME] || !a[OVS_VPORT_ATTR_TYPE] ||
1982 	    !a[OVS_VPORT_ATTR_UPCALL_PID])
1983 		return -EINVAL;
1984 
1985 	port_no = a[OVS_VPORT_ATTR_PORT_NO]
1986 		? nla_get_u32(a[OVS_VPORT_ATTR_PORT_NO]) : 0;
1987 	if (port_no >= DP_MAX_PORTS)
1988 		return -EFBIG;
1989 
1990 	reply = ovs_vport_cmd_alloc_info();
1991 	if (!reply)
1992 		return -ENOMEM;
1993 
1994 	ovs_lock();
1995 restart:
1996 	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
1997 	err = -ENODEV;
1998 	if (!dp)
1999 		goto exit_unlock_free;
2000 
2001 	if (port_no) {
2002 		vport = ovs_vport_ovsl(dp, port_no);
2003 		err = -EBUSY;
2004 		if (vport)
2005 			goto exit_unlock_free;
2006 	} else {
2007 		for (port_no = 1; ; port_no++) {
2008 			if (port_no >= DP_MAX_PORTS) {
2009 				err = -EFBIG;
2010 				goto exit_unlock_free;
2011 			}
2012 			vport = ovs_vport_ovsl(dp, port_no);
2013 			if (!vport)
2014 				break;
2015 		}
2016 	}
2017 
2018 	parms.name = nla_data(a[OVS_VPORT_ATTR_NAME]);
2019 	parms.type = nla_get_u32(a[OVS_VPORT_ATTR_TYPE]);
2020 	parms.options = a[OVS_VPORT_ATTR_OPTIONS];
2021 	parms.dp = dp;
2022 	parms.port_no = port_no;
2023 	parms.upcall_portids = a[OVS_VPORT_ATTR_UPCALL_PID];
2024 
2025 	vport = new_vport(&parms);
2026 	err = PTR_ERR(vport);
2027 	if (IS_ERR(vport)) {
2028 		if (err == -EAGAIN)
2029 			goto restart;
2030 		goto exit_unlock_free;
2031 	}
2032 
2033 	err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
2034 				      info->snd_seq, 0, OVS_VPORT_CMD_NEW);
2035 
2036 	if (netdev_get_fwd_headroom(vport->dev) > dp->max_headroom)
2037 		update_headroom(dp);
2038 	else
2039 		netdev_set_rx_headroom(vport->dev, dp->max_headroom);
2040 
2041 	BUG_ON(err < 0);
2042 	ovs_unlock();
2043 
2044 	ovs_notify(&dp_vport_genl_family, reply, info);
2045 	return 0;
2046 
2047 exit_unlock_free:
2048 	ovs_unlock();
2049 	kfree_skb(reply);
2050 	return err;
2051 }
2052 
2053 static int ovs_vport_cmd_set(struct sk_buff *skb, struct genl_info *info)
2054 {
2055 	struct nlattr **a = info->attrs;
2056 	struct sk_buff *reply;
2057 	struct vport *vport;
2058 	int err;
2059 
2060 	reply = ovs_vport_cmd_alloc_info();
2061 	if (!reply)
2062 		return -ENOMEM;
2063 
2064 	ovs_lock();
2065 	vport = lookup_vport(sock_net(skb->sk), info->userhdr, a);
2066 	err = PTR_ERR(vport);
2067 	if (IS_ERR(vport))
2068 		goto exit_unlock_free;
2069 
2070 	if (a[OVS_VPORT_ATTR_TYPE] &&
2071 	    nla_get_u32(a[OVS_VPORT_ATTR_TYPE]) != vport->ops->type) {
2072 		err = -EINVAL;
2073 		goto exit_unlock_free;
2074 	}
2075 
2076 	if (a[OVS_VPORT_ATTR_OPTIONS]) {
2077 		err = ovs_vport_set_options(vport, a[OVS_VPORT_ATTR_OPTIONS]);
2078 		if (err)
2079 			goto exit_unlock_free;
2080 	}
2081 
2082 
2083 	if (a[OVS_VPORT_ATTR_UPCALL_PID]) {
2084 		struct nlattr *ids = a[OVS_VPORT_ATTR_UPCALL_PID];
2085 
2086 		err = ovs_vport_set_upcall_portids(vport, ids);
2087 		if (err)
2088 			goto exit_unlock_free;
2089 	}
2090 
2091 	err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
2092 				      info->snd_seq, 0, OVS_VPORT_CMD_NEW);
2093 	BUG_ON(err < 0);
2094 
2095 	ovs_unlock();
2096 	ovs_notify(&dp_vport_genl_family, reply, info);
2097 	return 0;
2098 
2099 exit_unlock_free:
2100 	ovs_unlock();
2101 	kfree_skb(reply);
2102 	return err;
2103 }
2104 
2105 static int ovs_vport_cmd_del(struct sk_buff *skb, struct genl_info *info)
2106 {
2107 	bool must_update_headroom = false;
2108 	struct nlattr **a = info->attrs;
2109 	struct sk_buff *reply;
2110 	struct datapath *dp;
2111 	struct vport *vport;
2112 	int err;
2113 
2114 	reply = ovs_vport_cmd_alloc_info();
2115 	if (!reply)
2116 		return -ENOMEM;
2117 
2118 	ovs_lock();
2119 	vport = lookup_vport(sock_net(skb->sk), info->userhdr, a);
2120 	err = PTR_ERR(vport);
2121 	if (IS_ERR(vport))
2122 		goto exit_unlock_free;
2123 
2124 	if (vport->port_no == OVSP_LOCAL) {
2125 		err = -EINVAL;
2126 		goto exit_unlock_free;
2127 	}
2128 
2129 	err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
2130 				      info->snd_seq, 0, OVS_VPORT_CMD_DEL);
2131 	BUG_ON(err < 0);
2132 
2133 	/* the vport deletion may trigger dp headroom update */
2134 	dp = vport->dp;
2135 	if (netdev_get_fwd_headroom(vport->dev) == dp->max_headroom)
2136 		must_update_headroom = true;
2137 	netdev_reset_rx_headroom(vport->dev);
2138 	ovs_dp_detach_port(vport);
2139 
2140 	if (must_update_headroom)
2141 		update_headroom(dp);
2142 	ovs_unlock();
2143 
2144 	ovs_notify(&dp_vport_genl_family, reply, info);
2145 	return 0;
2146 
2147 exit_unlock_free:
2148 	ovs_unlock();
2149 	kfree_skb(reply);
2150 	return err;
2151 }
2152 
2153 static int ovs_vport_cmd_get(struct sk_buff *skb, struct genl_info *info)
2154 {
2155 	struct nlattr **a = info->attrs;
2156 	struct ovs_header *ovs_header = info->userhdr;
2157 	struct sk_buff *reply;
2158 	struct vport *vport;
2159 	int err;
2160 
2161 	reply = ovs_vport_cmd_alloc_info();
2162 	if (!reply)
2163 		return -ENOMEM;
2164 
2165 	rcu_read_lock();
2166 	vport = lookup_vport(sock_net(skb->sk), ovs_header, a);
2167 	err = PTR_ERR(vport);
2168 	if (IS_ERR(vport))
2169 		goto exit_unlock_free;
2170 	err = ovs_vport_cmd_fill_info(vport, reply, info->snd_portid,
2171 				      info->snd_seq, 0, OVS_VPORT_CMD_NEW);
2172 	BUG_ON(err < 0);
2173 	rcu_read_unlock();
2174 
2175 	return genlmsg_reply(reply, info);
2176 
2177 exit_unlock_free:
2178 	rcu_read_unlock();
2179 	kfree_skb(reply);
2180 	return err;
2181 }
2182 
2183 static int ovs_vport_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
2184 {
2185 	struct ovs_header *ovs_header = genlmsg_data(nlmsg_data(cb->nlh));
2186 	struct datapath *dp;
2187 	int bucket = cb->args[0], skip = cb->args[1];
2188 	int i, j = 0;
2189 
2190 	rcu_read_lock();
2191 	dp = get_dp_rcu(sock_net(skb->sk), ovs_header->dp_ifindex);
2192 	if (!dp) {
2193 		rcu_read_unlock();
2194 		return -ENODEV;
2195 	}
2196 	for (i = bucket; i < DP_VPORT_HASH_BUCKETS; i++) {
2197 		struct vport *vport;
2198 
2199 		j = 0;
2200 		hlist_for_each_entry_rcu(vport, &dp->ports[i], dp_hash_node) {
2201 			if (j >= skip &&
2202 			    ovs_vport_cmd_fill_info(vport, skb,
2203 						    NETLINK_CB(cb->skb).portid,
2204 						    cb->nlh->nlmsg_seq,
2205 						    NLM_F_MULTI,
2206 						    OVS_VPORT_CMD_NEW) < 0)
2207 				goto out;
2208 
2209 			j++;
2210 		}
2211 		skip = 0;
2212 	}
2213 out:
2214 	rcu_read_unlock();
2215 
2216 	cb->args[0] = i;
2217 	cb->args[1] = j;
2218 
2219 	return skb->len;
2220 }
2221 
2222 static const struct nla_policy vport_policy[OVS_VPORT_ATTR_MAX + 1] = {
2223 	[OVS_VPORT_ATTR_NAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
2224 	[OVS_VPORT_ATTR_STATS] = { .len = sizeof(struct ovs_vport_stats) },
2225 	[OVS_VPORT_ATTR_PORT_NO] = { .type = NLA_U32 },
2226 	[OVS_VPORT_ATTR_TYPE] = { .type = NLA_U32 },
2227 	[OVS_VPORT_ATTR_UPCALL_PID] = { .type = NLA_U32 },
2228 	[OVS_VPORT_ATTR_OPTIONS] = { .type = NLA_NESTED },
2229 };
2230 
2231 static const struct genl_ops dp_vport_genl_ops[] = {
2232 	{ .cmd = OVS_VPORT_CMD_NEW,
2233 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
2234 	  .policy = vport_policy,
2235 	  .doit = ovs_vport_cmd_new
2236 	},
2237 	{ .cmd = OVS_VPORT_CMD_DEL,
2238 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
2239 	  .policy = vport_policy,
2240 	  .doit = ovs_vport_cmd_del
2241 	},
2242 	{ .cmd = OVS_VPORT_CMD_GET,
2243 	  .flags = 0,		    /* OK for unprivileged users. */
2244 	  .policy = vport_policy,
2245 	  .doit = ovs_vport_cmd_get,
2246 	  .dumpit = ovs_vport_cmd_dump
2247 	},
2248 	{ .cmd = OVS_VPORT_CMD_SET,
2249 	  .flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
2250 	  .policy = vport_policy,
2251 	  .doit = ovs_vport_cmd_set,
2252 	},
2253 };
2254 
2255 struct genl_family dp_vport_genl_family __ro_after_init = {
2256 	.hdrsize = sizeof(struct ovs_header),
2257 	.name = OVS_VPORT_FAMILY,
2258 	.version = OVS_VPORT_VERSION,
2259 	.maxattr = OVS_VPORT_ATTR_MAX,
2260 	.netnsok = true,
2261 	.parallel_ops = true,
2262 	.ops = dp_vport_genl_ops,
2263 	.n_ops = ARRAY_SIZE(dp_vport_genl_ops),
2264 	.mcgrps = &ovs_dp_vport_multicast_group,
2265 	.n_mcgrps = 1,
2266 	.module = THIS_MODULE,
2267 };
2268 
2269 static struct genl_family * const dp_genl_families[] = {
2270 	&dp_datapath_genl_family,
2271 	&dp_vport_genl_family,
2272 	&dp_flow_genl_family,
2273 	&dp_packet_genl_family,
2274 };
2275 
2276 static void dp_unregister_genl(int n_families)
2277 {
2278 	int i;
2279 
2280 	for (i = 0; i < n_families; i++)
2281 		genl_unregister_family(dp_genl_families[i]);
2282 }
2283 
2284 static int __init dp_register_genl(void)
2285 {
2286 	int err;
2287 	int i;
2288 
2289 	for (i = 0; i < ARRAY_SIZE(dp_genl_families); i++) {
2290 
2291 		err = genl_register_family(dp_genl_families[i]);
2292 		if (err)
2293 			goto error;
2294 	}
2295 
2296 	return 0;
2297 
2298 error:
2299 	dp_unregister_genl(i);
2300 	return err;
2301 }
2302 
2303 static int __net_init ovs_init_net(struct net *net)
2304 {
2305 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2306 
2307 	INIT_LIST_HEAD(&ovs_net->dps);
2308 	INIT_WORK(&ovs_net->dp_notify_work, ovs_dp_notify_wq);
2309 	ovs_ct_init(net);
2310 	return 0;
2311 }
2312 
2313 static void __net_exit list_vports_from_net(struct net *net, struct net *dnet,
2314 					    struct list_head *head)
2315 {
2316 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2317 	struct datapath *dp;
2318 
2319 	list_for_each_entry(dp, &ovs_net->dps, list_node) {
2320 		int i;
2321 
2322 		for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++) {
2323 			struct vport *vport;
2324 
2325 			hlist_for_each_entry(vport, &dp->ports[i], dp_hash_node) {
2326 				if (vport->ops->type != OVS_VPORT_TYPE_INTERNAL)
2327 					continue;
2328 
2329 				if (dev_net(vport->dev) == dnet)
2330 					list_add(&vport->detach_list, head);
2331 			}
2332 		}
2333 	}
2334 }
2335 
2336 static void __net_exit ovs_exit_net(struct net *dnet)
2337 {
2338 	struct datapath *dp, *dp_next;
2339 	struct ovs_net *ovs_net = net_generic(dnet, ovs_net_id);
2340 	struct vport *vport, *vport_next;
2341 	struct net *net;
2342 	LIST_HEAD(head);
2343 
2344 	ovs_ct_exit(dnet);
2345 	ovs_lock();
2346 	list_for_each_entry_safe(dp, dp_next, &ovs_net->dps, list_node)
2347 		__dp_destroy(dp);
2348 
2349 	rtnl_lock();
2350 	for_each_net(net)
2351 		list_vports_from_net(net, dnet, &head);
2352 	rtnl_unlock();
2353 
2354 	/* Detach all vports from given namespace. */
2355 	list_for_each_entry_safe(vport, vport_next, &head, detach_list) {
2356 		list_del(&vport->detach_list);
2357 		ovs_dp_detach_port(vport);
2358 	}
2359 
2360 	ovs_unlock();
2361 
2362 	cancel_work_sync(&ovs_net->dp_notify_work);
2363 }
2364 
2365 static struct pernet_operations ovs_net_ops = {
2366 	.init = ovs_init_net,
2367 	.exit = ovs_exit_net,
2368 	.id   = &ovs_net_id,
2369 	.size = sizeof(struct ovs_net),
2370 };
2371 
2372 static int __init dp_init(void)
2373 {
2374 	int err;
2375 
2376 	BUILD_BUG_ON(sizeof(struct ovs_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
2377 
2378 	pr_info("Open vSwitch switching datapath\n");
2379 
2380 	err = action_fifos_init();
2381 	if (err)
2382 		goto error;
2383 
2384 	err = ovs_internal_dev_rtnl_link_register();
2385 	if (err)
2386 		goto error_action_fifos_exit;
2387 
2388 	err = ovs_flow_init();
2389 	if (err)
2390 		goto error_unreg_rtnl_link;
2391 
2392 	err = ovs_vport_init();
2393 	if (err)
2394 		goto error_flow_exit;
2395 
2396 	err = register_pernet_device(&ovs_net_ops);
2397 	if (err)
2398 		goto error_vport_exit;
2399 
2400 	err = register_netdevice_notifier(&ovs_dp_device_notifier);
2401 	if (err)
2402 		goto error_netns_exit;
2403 
2404 	err = ovs_netdev_init();
2405 	if (err)
2406 		goto error_unreg_notifier;
2407 
2408 	err = dp_register_genl();
2409 	if (err < 0)
2410 		goto error_unreg_netdev;
2411 
2412 	return 0;
2413 
2414 error_unreg_netdev:
2415 	ovs_netdev_exit();
2416 error_unreg_notifier:
2417 	unregister_netdevice_notifier(&ovs_dp_device_notifier);
2418 error_netns_exit:
2419 	unregister_pernet_device(&ovs_net_ops);
2420 error_vport_exit:
2421 	ovs_vport_exit();
2422 error_flow_exit:
2423 	ovs_flow_exit();
2424 error_unreg_rtnl_link:
2425 	ovs_internal_dev_rtnl_link_unregister();
2426 error_action_fifos_exit:
2427 	action_fifos_exit();
2428 error:
2429 	return err;
2430 }
2431 
2432 static void dp_cleanup(void)
2433 {
2434 	dp_unregister_genl(ARRAY_SIZE(dp_genl_families));
2435 	ovs_netdev_exit();
2436 	unregister_netdevice_notifier(&ovs_dp_device_notifier);
2437 	unregister_pernet_device(&ovs_net_ops);
2438 	rcu_barrier();
2439 	ovs_vport_exit();
2440 	ovs_flow_exit();
2441 	ovs_internal_dev_rtnl_link_unregister();
2442 	action_fifos_exit();
2443 }
2444 
2445 module_init(dp_init);
2446 module_exit(dp_cleanup);
2447 
2448 MODULE_DESCRIPTION("Open vSwitch switching datapath");
2449 MODULE_LICENSE("GPL");
2450 MODULE_ALIAS_GENL_FAMILY(OVS_DATAPATH_FAMILY);
2451 MODULE_ALIAS_GENL_FAMILY(OVS_VPORT_FAMILY);
2452 MODULE_ALIAS_GENL_FAMILY(OVS_FLOW_FAMILY);
2453 MODULE_ALIAS_GENL_FAMILY(OVS_PACKET_FAMILY);
2454