datapath.c 45.6 KB
Newer Older
1
/*
2
 * Copyright (c) 2007-2013 Nicira, Inc.
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/jhash.h>
#include <linux/delay.h>
#include <linux/time.h>
#include <linux/etherdevice.h>
#include <linux/genetlink.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/percpu.h>
#include <linux/rcupdate.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/ethtool.h>
#include <linux/wait.h>
#include <asm/div64.h>
#include <linux/highmem.h>
#include <linux/netfilter_bridge.h>
#include <linux/netfilter_ipv4.h>
#include <linux/inetdevice.h>
#include <linux/list.h>
47
#include <linux/lockdep.h>
48 49 50 51 52
#include <linux/openvswitch.h>
#include <linux/rculist.h>
#include <linux/dmi.h>
#include <linux/workqueue.h>
#include <net/genetlink.h>
53 54
#include <net/net_namespace.h>
#include <net/netns/generic.h>
55 56 57

#include "datapath.h"
#include "flow.h"
58
#include "flow_netlink.h"
59
#include "vport-internal_dev.h"
60
#include "vport-netdev.h"
61

62 63
int ovs_net_id __read_mostly;

64 65 66 67 68 69 70
static void ovs_notify(struct sk_buff *skb, struct genl_info *info,
		       struct genl_multicast_group *grp)
{
	genl_notify(skb, genl_info_net(info), info->snd_portid,
		    grp->id, info->nlhdr, GFP_KERNEL);
}

71 72 73
/**
 * DOC: Locking:
 *
74 75 76 77
 * All writes e.g. Writes to device state (add/remove datapath, port, set
 * operations on vports, etc.), Writes to other state (flow table
 * modifications, set miscellaneous datapath parameters, etc.) are protected
 * by ovs_lock.
78 79 80 81 82 83
 *
 * Reads are protected by RCU.
 *
 * There are a few special cases (mostly stats) that have their own
 * synchronization but they nest under all of above and don't interact with
 * each other.
84 85
 *
 * The RTNL lock nests inside ovs_mutex.
86 87
 */

88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
static DEFINE_MUTEX(ovs_mutex);

void ovs_lock(void)
{
	mutex_lock(&ovs_mutex);
}

void ovs_unlock(void)
{
	mutex_unlock(&ovs_mutex);
}

#ifdef CONFIG_LOCKDEP
int lockdep_ovsl_is_held(void)
{
	if (debug_locks)
		return lockdep_is_held(&ovs_mutex);
	else
		return 1;
}
#endif

110
static struct vport *new_vport(const struct vport_parms *);
111
static int queue_gso_packets(struct net *, int dp_ifindex, struct sk_buff *,
112
			     const struct dp_upcall_info *);
113 114
static int queue_userspace_packet(struct net *, int dp_ifindex,
				  struct sk_buff *,
115 116
				  const struct dp_upcall_info *);

117
/* Must be called with rcu_read_lock or ovs_mutex. */
118
static struct datapath *get_dp(struct net *net, int dp_ifindex)
119 120 121 122 123
{
	struct datapath *dp = NULL;
	struct net_device *dev;

	rcu_read_lock();
124
	dev = dev_get_by_index_rcu(net, dp_ifindex);
125 126 127 128 129 130 131 132 133 134
	if (dev) {
		struct vport *vport = ovs_internal_dev_get_vport(dev);
		if (vport)
			dp = vport->dp;
	}
	rcu_read_unlock();

	return dp;
}

135
/* Must be called with rcu_read_lock or ovs_mutex. */
136 137
const char *ovs_dp_name(const struct datapath *dp)
{
138
	struct vport *vport = ovs_vport_ovsl_rcu(dp, OVSP_LOCAL);
139 140 141 142 143 144 145 146 147 148
	return vport->ops->get_name(vport);
}

static int get_dpifindex(struct datapath *dp)
{
	struct vport *local;
	int ifindex;

	rcu_read_lock();

149
	local = ovs_vport_rcu(dp, OVSP_LOCAL);
150
	if (local)
151
		ifindex = netdev_vport_priv(local)->dev->ifindex;
152 153 154 155 156 157 158 159 160 161 162 163
	else
		ifindex = 0;

	rcu_read_unlock();

	return ifindex;
}

static void destroy_dp_rcu(struct rcu_head *rcu)
{
	struct datapath *dp = container_of(rcu, struct datapath, rcu);

164
	ovs_flow_tbl_destroy(&dp->table);
165
	free_percpu(dp->stats_percpu);
166
	release_net(ovs_dp_get_net(dp));
167
	kfree(dp->ports);
168 169 170
	kfree(dp);
}

171 172 173 174 175 176 177 178 179 180 181 182
static struct hlist_head *vport_hash_bucket(const struct datapath *dp,
					    u16 port_no)
{
	return &dp->ports[port_no & (DP_VPORT_HASH_BUCKETS - 1)];
}

struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no)
{
	struct vport *vport;
	struct hlist_head *head;

	head = vport_hash_bucket(dp, port_no);
183
	hlist_for_each_entry_rcu(vport, head, dp_hash_node) {
184 185 186 187 188 189
		if (vport->port_no == port_no)
			return vport;
	}
	return NULL;
}

190
/* Called with ovs_mutex. */
191 192 193 194 195 196 197
static struct vport *new_vport(const struct vport_parms *parms)
{
	struct vport *vport;

	vport = ovs_vport_add(parms);
	if (!IS_ERR(vport)) {
		struct datapath *dp = parms->dp;
198
		struct hlist_head *head = vport_hash_bucket(dp, vport->port_no);
199

200
		hlist_add_head_rcu(&vport->dp_hash_node, head);
201 202 203 204 205 206
	}
	return vport;
}

void ovs_dp_detach_port(struct vport *p)
{
207
	ASSERT_OVSL();
208 209

	/* First drop references to device. */
210
	hlist_del_rcu(&p->dp_hash_node);
211 212 213 214 215 216 217 218 219 220 221 222 223

	/* Then destroy it. */
	ovs_vport_del(p);
}

/* Must be called with rcu_read_lock. */
void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
{
	struct datapath *dp = p->dp;
	struct sw_flow *flow;
	struct dp_stats_percpu *stats;
	struct sw_flow_key key;
	u64 *stats_counter;
224
	u32 n_mask_hit;
225 226
	int error;

227
	stats = this_cpu_ptr(dp->stats_percpu);
228 229

	/* Extract flow from 'skb' into 'key'. */
230
	error = ovs_flow_extract(skb, p->port_no, &key);
231 232 233 234 235 236
	if (unlikely(error)) {
		kfree_skb(skb);
		return;
	}

	/* Look up flow. */
237
	flow = ovs_flow_tbl_lookup(&dp->table, &key, &n_mask_hit);
238 239 240 241 242 243
	if (unlikely(!flow)) {
		struct dp_upcall_info upcall;

		upcall.cmd = OVS_PACKET_CMD_MISS;
		upcall.key = &key;
		upcall.userdata = NULL;
244
		upcall.portid = p->upcall_portid;
245 246 247 248 249 250 251
		ovs_dp_upcall(dp, skb, &upcall);
		consume_skb(skb);
		stats_counter = &stats->n_missed;
		goto out;
	}

	OVS_CB(skb)->flow = flow;
252
	OVS_CB(skb)->pkt_key = &key;
253 254 255 256 257 258 259 260 261

	stats_counter = &stats->n_hit;
	ovs_flow_used(OVS_CB(skb)->flow, skb);
	ovs_execute_actions(dp, skb);

out:
	/* Update datapath statistics. */
	u64_stats_update_begin(&stats->sync);
	(*stats_counter)++;
262
	stats->n_mask_hit += n_mask_hit;
263 264 265 266 267 268 269 270
	u64_stats_update_end(&stats->sync);
}

static struct genl_family dp_packet_genl_family = {
	.id = GENL_ID_GENERATE,
	.hdrsize = sizeof(struct ovs_header),
	.name = OVS_PACKET_FAMILY,
	.version = OVS_PACKET_VERSION,
271
	.maxattr = OVS_PACKET_ATTR_MAX,
272 273
	.netnsok = true,
	.parallel_ops = true,
274 275 276
};

int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
277
		  const struct dp_upcall_info *upcall_info)
278 279 280 281 282
{
	struct dp_stats_percpu *stats;
	int dp_ifindex;
	int err;

283
	if (upcall_info->portid == 0) {
284 285 286 287 288 289 290 291 292 293 294
		err = -ENOTCONN;
		goto err;
	}

	dp_ifindex = get_dpifindex(dp);
	if (!dp_ifindex) {
		err = -ENODEV;
		goto err;
	}

	if (!skb_is_gso(skb))
295
		err = queue_userspace_packet(ovs_dp_get_net(dp), dp_ifindex, skb, upcall_info);
296
	else
297
		err = queue_gso_packets(ovs_dp_get_net(dp), dp_ifindex, skb, upcall_info);
298 299 300 301 302 303
	if (err)
		goto err;

	return 0;

err:
304
	stats = this_cpu_ptr(dp->stats_percpu);
305 306 307 308 309 310 311 312

	u64_stats_update_begin(&stats->sync);
	stats->n_lost++;
	u64_stats_update_end(&stats->sync);

	return err;
}

313 314
static int queue_gso_packets(struct net *net, int dp_ifindex,
			     struct sk_buff *skb,
315 316
			     const struct dp_upcall_info *upcall_info)
{
317
	unsigned short gso_type = skb_shinfo(skb)->gso_type;
318 319 320 321 322
	struct dp_upcall_info later_info;
	struct sw_flow_key later_key;
	struct sk_buff *segs, *nskb;
	int err;

323
	segs = __skb_gso_segment(skb, NETIF_F_SG | NETIF_F_HW_CSUM, false);
324 325
	if (IS_ERR(segs))
		return PTR_ERR(segs);
326 327 328 329

	/* Queue all of the segments. */
	skb = segs;
	do {
330
		err = queue_userspace_packet(net, dp_ifindex, skb, upcall_info);
331 332 333
		if (err)
			break;

334
		if (skb == segs && gso_type & SKB_GSO_UDP) {
335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359
			/* The initial flow key extracted by ovs_flow_extract()
			 * in this case is for a first fragment, so we need to
			 * properly mark later fragments.
			 */
			later_key = *upcall_info->key;
			later_key.ip.frag = OVS_FRAG_TYPE_LATER;

			later_info = *upcall_info;
			later_info.key = &later_key;
			upcall_info = &later_info;
		}
	} while ((skb = skb->next));

	/* Free all of the segments. */
	skb = segs;
	do {
		nskb = skb->next;
		if (err)
			kfree_skb(skb);
		else
			consume_skb(skb);
	} while ((skb = nskb));
	return err;
}

360 361 362
static size_t key_attr_size(void)
{
	return    nla_total_size(4)   /* OVS_KEY_ATTR_PRIORITY */
363 364 365 366 367 368 369 370
		+ nla_total_size(0)   /* OVS_KEY_ATTR_TUNNEL */
		  + nla_total_size(8)   /* OVS_TUNNEL_KEY_ATTR_ID */
		  + nla_total_size(4)   /* OVS_TUNNEL_KEY_ATTR_IPV4_SRC */
		  + nla_total_size(4)   /* OVS_TUNNEL_KEY_ATTR_IPV4_DST */
		  + nla_total_size(1)   /* OVS_TUNNEL_KEY_ATTR_TOS */
		  + nla_total_size(1)   /* OVS_TUNNEL_KEY_ATTR_TTL */
		  + nla_total_size(0)   /* OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT */
		  + nla_total_size(0)   /* OVS_TUNNEL_KEY_ATTR_CSUM */
371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396
		+ nla_total_size(4)   /* OVS_KEY_ATTR_IN_PORT */
		+ nla_total_size(4)   /* OVS_KEY_ATTR_SKB_MARK */
		+ nla_total_size(12)  /* OVS_KEY_ATTR_ETHERNET */
		+ nla_total_size(2)   /* OVS_KEY_ATTR_ETHERTYPE */
		+ nla_total_size(4)   /* OVS_KEY_ATTR_8021Q */
		+ nla_total_size(0)   /* OVS_KEY_ATTR_ENCAP */
		+ nla_total_size(2)   /* OVS_KEY_ATTR_ETHERTYPE */
		+ nla_total_size(40)  /* OVS_KEY_ATTR_IPV6 */
		+ nla_total_size(2)   /* OVS_KEY_ATTR_ICMPV6 */
		+ nla_total_size(28); /* OVS_KEY_ATTR_ND */
}

static size_t upcall_msg_size(const struct sk_buff *skb,
			      const struct nlattr *userdata)
{
	size_t size = NLMSG_ALIGN(sizeof(struct ovs_header))
		+ nla_total_size(skb->len) /* OVS_PACKET_ATTR_PACKET */
		+ nla_total_size(key_attr_size()); /* OVS_PACKET_ATTR_KEY */

	/* OVS_PACKET_ATTR_USERDATA */
	if (userdata)
		size += NLA_ALIGN(userdata->nla_len);

	return size;
}

397 398
static int queue_userspace_packet(struct net *net, int dp_ifindex,
				  struct sk_buff *skb,
399 400 401 402 403 404 405 406 407 408 409 410 411
				  const struct dp_upcall_info *upcall_info)
{
	struct ovs_header *upcall;
	struct sk_buff *nskb = NULL;
	struct sk_buff *user_skb; /* to be queued to userspace */
	struct nlattr *nla;
	int err;

	if (vlan_tx_tag_present(skb)) {
		nskb = skb_clone(skb, GFP_ATOMIC);
		if (!nskb)
			return -ENOMEM;

412
		nskb = __vlan_put_tag(nskb, nskb->vlan_proto, vlan_tx_tag_get(nskb));
413
		if (!nskb)
414 415 416 417 418 419 420 421 422 423 424
			return -ENOMEM;

		nskb->vlan_tci = 0;
		skb = nskb;
	}

	if (nla_attr_size(skb->len) > USHRT_MAX) {
		err = -EFBIG;
		goto out;
	}

425
	user_skb = genlmsg_new(upcall_msg_size(skb, upcall_info->userdata), GFP_ATOMIC);
426 427 428 429 430 431 432 433 434 435
	if (!user_skb) {
		err = -ENOMEM;
		goto out;
	}

	upcall = genlmsg_put(user_skb, 0, 0, &dp_packet_genl_family,
			     0, upcall_info->cmd);
	upcall->dp_ifindex = dp_ifindex;

	nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_KEY);
436
	ovs_nla_put_flow(upcall_info->key, upcall_info->key, user_skb);
437 438 439
	nla_nest_end(user_skb, nla);

	if (upcall_info->userdata)
440 441 442
		__nla_put(user_skb, OVS_PACKET_ATTR_USERDATA,
			  nla_len(upcall_info->userdata),
			  nla_data(upcall_info->userdata));
443 444 445 446 447

	nla = __nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, skb->len);

	skb_copy_and_csum_dev(skb, nla_data(nla));

448
	genlmsg_end(user_skb, upcall);
449
	err = genlmsg_unicast(net, user_skb, upcall_info->portid);
450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477

out:
	kfree_skb(nskb);
	return err;
}

static void clear_stats(struct sw_flow *flow)
{
	flow->used = 0;
	flow->tcp_flags = 0;
	flow->packet_count = 0;
	flow->byte_count = 0;
}

static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
{
	struct ovs_header *ovs_header = info->userhdr;
	struct nlattr **a = info->attrs;
	struct sw_flow_actions *acts;
	struct sk_buff *packet;
	struct sw_flow *flow;
	struct datapath *dp;
	struct ethhdr *eth;
	int len;
	int err;

	err = -EINVAL;
	if (!a[OVS_PACKET_ATTR_PACKET] || !a[OVS_PACKET_ATTR_KEY] ||
478
	    !a[OVS_PACKET_ATTR_ACTIONS])
479 480 481 482 483 484 485 486 487
		goto err;

	len = nla_len(a[OVS_PACKET_ATTR_PACKET]);
	packet = __dev_alloc_skb(NET_IP_ALIGN + len, GFP_KERNEL);
	err = -ENOMEM;
	if (!packet)
		goto err;
	skb_reserve(packet, NET_IP_ALIGN);

488
	nla_memcpy(__skb_put(packet, len), a[OVS_PACKET_ATTR_PACKET], len);
489 490 491 492 493 494 495

	skb_reset_mac_header(packet);
	eth = eth_hdr(packet);

	/* Normally, setting the skb 'protocol' field would be handled by a
	 * call to eth_type_trans(), but it assumes there's a sending
	 * device, which we may not have. */
Simon Horman's avatar
Simon Horman committed
496
	if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN)
497 498 499 500 501 502 503 504 505 506
		packet->protocol = eth->h_proto;
	else
		packet->protocol = htons(ETH_P_802_2);

	/* Build an sw_flow for sending this packet. */
	flow = ovs_flow_alloc();
	err = PTR_ERR(flow);
	if (IS_ERR(flow))
		goto err_kfree_skb;

507
	err = ovs_flow_extract(packet, -1, &flow->key);
508 509 510
	if (err)
		goto err_flow_free;

511
	err = ovs_nla_get_flow_metadata(flow, a[OVS_PACKET_ATTR_KEY]);
512 513
	if (err)
		goto err_flow_free;
514
	acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_PACKET_ATTR_ACTIONS]));
515 516 517
	err = PTR_ERR(acts);
	if (IS_ERR(acts))
		goto err_flow_free;
518

519 520
	err = ovs_nla_copy_actions(a[OVS_PACKET_ATTR_ACTIONS],
				   &flow->key, 0, &acts);
521
	rcu_assign_pointer(flow->sf_acts, acts);
522 523
	if (err)
		goto err_flow_free;
524 525

	OVS_CB(packet)->flow = flow;
526
	OVS_CB(packet)->pkt_key = &flow->key;
527
	packet->priority = flow->key.phy.priority;
528
	packet->mark = flow->key.phy.skb_mark;
529 530

	rcu_read_lock();
531
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
532 533 534 535 536 537 538 539 540
	err = -ENODEV;
	if (!dp)
		goto err_unlock;

	local_bh_disable();
	err = ovs_execute_actions(dp, packet);
	local_bh_enable();
	rcu_read_unlock();

541
	ovs_flow_free(flow, false);
542 543 544 545 546
	return err;

err_unlock:
	rcu_read_unlock();
err_flow_free:
547
	ovs_flow_free(flow, false);
548 549 550 551 552 553 554
err_kfree_skb:
	kfree_skb(packet);
err:
	return err;
}

static const struct nla_policy packet_policy[OVS_PACKET_ATTR_MAX + 1] = {
555
	[OVS_PACKET_ATTR_PACKET] = { .len = ETH_HLEN },
556 557 558 559 560 561 562 563 564 565 566 567
	[OVS_PACKET_ATTR_KEY] = { .type = NLA_NESTED },
	[OVS_PACKET_ATTR_ACTIONS] = { .type = NLA_NESTED },
};

static struct genl_ops dp_packet_genl_ops[] = {
	{ .cmd = OVS_PACKET_CMD_EXECUTE,
	  .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
	  .policy = packet_policy,
	  .doit = ovs_packet_cmd_execute
	}
};

568 569
static void get_dp_stats(struct datapath *dp, struct ovs_dp_stats *stats,
			 struct ovs_dp_megaflow_stats *mega_stats)
570 571 572
{
	int i;

573 574
	memset(mega_stats, 0, sizeof(*mega_stats));

575
	stats->n_flows = ovs_flow_tbl_count(&dp->table);
576
	mega_stats->n_masks = ovs_flow_tbl_num_masks(&dp->table);
577 578

	stats->n_hit = stats->n_missed = stats->n_lost = 0;
579

580 581 582 583 584 585 586 587 588 589 590 591 592 593 594
	for_each_possible_cpu(i) {
		const struct dp_stats_percpu *percpu_stats;
		struct dp_stats_percpu local_stats;
		unsigned int start;

		percpu_stats = per_cpu_ptr(dp->stats_percpu, i);

		do {
			start = u64_stats_fetch_begin_bh(&percpu_stats->sync);
			local_stats = *percpu_stats;
		} while (u64_stats_fetch_retry_bh(&percpu_stats->sync, start));

		stats->n_hit += local_stats.n_hit;
		stats->n_missed += local_stats.n_missed;
		stats->n_lost += local_stats.n_lost;
595
		mega_stats->n_mask_hit += local_stats.n_mask_hit;
596 597 598 599 600 601 602 603 604 605 606 607 608 609
	}
}

static const struct nla_policy flow_policy[OVS_FLOW_ATTR_MAX + 1] = {
	[OVS_FLOW_ATTR_KEY] = { .type = NLA_NESTED },
	[OVS_FLOW_ATTR_ACTIONS] = { .type = NLA_NESTED },
	[OVS_FLOW_ATTR_CLEAR] = { .type = NLA_FLAG },
};

static struct genl_family dp_flow_genl_family = {
	.id = GENL_ID_GENERATE,
	.hdrsize = sizeof(struct ovs_header),
	.name = OVS_FLOW_FAMILY,
	.version = OVS_FLOW_VERSION,
610
	.maxattr = OVS_FLOW_ATTR_MAX,
611 612
	.netnsok = true,
	.parallel_ops = true,
613 614 615 616 617 618
};

static struct genl_multicast_group ovs_dp_flow_multicast_group = {
	.name = OVS_FLOW_MCGROUP
};

619 620 621 622
static size_t ovs_flow_cmd_msg_size(const struct sw_flow_actions *acts)
{
	return NLMSG_ALIGN(sizeof(struct ovs_header))
		+ nla_total_size(key_attr_size()) /* OVS_FLOW_ATTR_KEY */
623
		+ nla_total_size(key_attr_size()) /* OVS_FLOW_ATTR_MASK */
624 625 626 627 628 629
		+ nla_total_size(sizeof(struct ovs_flow_stats)) /* OVS_FLOW_ATTR_STATS */
		+ nla_total_size(1) /* OVS_FLOW_ATTR_TCP_FLAGS */
		+ nla_total_size(8) /* OVS_FLOW_ATTR_USED */
		+ nla_total_size(acts->actions_len); /* OVS_FLOW_ATTR_ACTIONS */
}

630
/* Called with ovs_mutex. */
631
static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
632
				  struct sk_buff *skb, u32 portid,
633 634 635
				  u32 seq, u32 flags, u8 cmd)
{
	const int skb_orig_len = skb->len;
636
	struct nlattr *start;
637 638 639 640 641 642 643
	struct ovs_flow_stats stats;
	struct ovs_header *ovs_header;
	struct nlattr *nla;
	unsigned long used;
	u8 tcp_flags;
	int err;

644
	ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family, flags, cmd);
645 646 647 648 649
	if (!ovs_header)
		return -EMSGSIZE;

	ovs_header->dp_ifindex = get_dpifindex(dp);

650
	/* Fill flow key. */
651 652 653
	nla = nla_nest_start(skb, OVS_FLOW_ATTR_KEY);
	if (!nla)
		goto nla_put_failure;
654

655
	err = ovs_nla_put_flow(&flow->unmasked_key, &flow->unmasked_key, skb);
656 657 658 659 660 661 662 663
	if (err)
		goto error;
	nla_nest_end(skb, nla);

	nla = nla_nest_start(skb, OVS_FLOW_ATTR_MASK);
	if (!nla)
		goto nla_put_failure;

664
	err = ovs_nla_put_flow(&flow->key, &flow->mask->key, skb);
665 666
	if (err)
		goto error;
667

668 669 670 671 672 673
	nla_nest_end(skb, nla);

	spin_lock_bh(&flow->lock);
	used = flow->used;
	stats.n_packets = flow->packet_count;
	stats.n_bytes = flow->byte_count;
674
	tcp_flags = (u8)ntohs(flow->tcp_flags);
675 676
	spin_unlock_bh(&flow->lock);

677 678 679
	if (used &&
	    nla_put_u64(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used)))
		goto nla_put_failure;
680

681 682 683 684
	if (stats.n_packets &&
	    nla_put(skb, OVS_FLOW_ATTR_STATS,
		    sizeof(struct ovs_flow_stats), &stats))
		goto nla_put_failure;
685

686 687 688
	if (tcp_flags &&
	    nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, tcp_flags))
		goto nla_put_failure;
689 690 691 692 693 694 695 696 697 698 699

	/* If OVS_FLOW_ATTR_ACTIONS doesn't fit, skip dumping the actions if
	 * this is the first flow to be dumped into 'skb'.  This is unusual for
	 * Netlink but individual action lists can be longer than
	 * NLMSG_GOODSIZE and thus entirely undumpable if we didn't do this.
	 * The userspace caller can always fetch the actions separately if it
	 * really wants them.  (Most userspace callers in fact don't care.)
	 *
	 * This can only fail for dump operations because the skb is always
	 * properly sized for single flows.
	 */
700 701
	start = nla_nest_start(skb, OVS_FLOW_ATTR_ACTIONS);
	if (start) {
702 703 704 705 706
		const struct sw_flow_actions *sf_acts;

		sf_acts = rcu_dereference_check(flow->sf_acts,
						lockdep_ovsl_is_held());

707 708
		err = ovs_nla_put_actions(sf_acts->actions,
					  sf_acts->actions_len, skb);
709 710 711 712 713 714 715 716 717 718
		if (!err)
			nla_nest_end(skb, start);
		else {
			if (skb_orig_len)
				goto error;

			nla_nest_cancel(skb, start);
		}
	} else if (skb_orig_len)
		goto nla_put_failure;
719 720 721 722 723 724 725 726 727 728 729 730 731 732

	return genlmsg_end(skb, ovs_header);

nla_put_failure:
	err = -EMSGSIZE;
error:
	genlmsg_cancel(skb, ovs_header);
	return err;
}

static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow)
{
	const struct sw_flow_actions *sf_acts;

733
	sf_acts = ovsl_dereference(flow->sf_acts);
734

735
	return genlmsg_new(ovs_flow_cmd_msg_size(sf_acts), GFP_KERNEL);
736 737 738 739
}

static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
					       struct datapath *dp,
740
					       u32 portid, u32 seq, u8 cmd)
741 742 743 744 745 746 747 748
{
	struct sk_buff *skb;
	int retval;

	skb = ovs_flow_cmd_alloc_info(flow);
	if (!skb)
		return ERR_PTR(-ENOMEM);

749
	retval = ovs_flow_cmd_fill_info(flow, dp, skb, portid, seq, 0, cmd);
750 751 752 753
	BUG_ON(retval < 0);
	return skb;
}

754 755 756 757 758 759 760 761
static struct sw_flow *__ovs_flow_tbl_lookup(struct flow_table *tbl,
					      const struct sw_flow_key *key)
{
	u32 __always_unused n_mask_hit;

	return ovs_flow_tbl_lookup(tbl, key, &n_mask_hit);
}

762 763 764 765
static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
{
	struct nlattr **a = info->attrs;
	struct ovs_header *ovs_header = info->userhdr;
766 767 768
	struct sw_flow_key key, masked_key;
	struct sw_flow *flow = NULL;
	struct sw_flow_mask mask;
769 770
	struct sk_buff *reply;
	struct datapath *dp;
771
	struct sw_flow_actions *acts = NULL;
772
	struct sw_flow_match match;
773 774 775 776 777 778
	int error;

	/* Extract key. */
	error = -EINVAL;
	if (!a[OVS_FLOW_ATTR_KEY])
		goto error;
779 780

	ovs_match_init(&match, &key, &mask);
781 782
	error = ovs_nla_get_match(&match,
				  a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);
783 784 785 786 787
	if (error)
		goto error;

	/* Validate actions. */
	if (a[OVS_FLOW_ATTR_ACTIONS]) {
788
		acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
789 790
		error = PTR_ERR(acts);
		if (IS_ERR(acts))
791
			goto error;
792

793 794 795
		ovs_flow_mask_key(&masked_key, &key, &mask);
		error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
					     &masked_key, 0, &acts);
796 797
		if (error) {
			OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
798
			goto err_kfree;
799
		}
800 801 802 803 804
	} else if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW) {
		error = -EINVAL;
		goto error;
	}

805
	ovs_lock();
806
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
807 808
	error = -ENODEV;
	if (!dp)
809
		goto err_unlock_ovs;
810

811
	/* Check if this is a duplicate flow */
812
	flow = __ovs_flow_tbl_lookup(&dp->table, &key);
813 814 815 816
	if (!flow) {
		/* Bail out if we're not allowed to create a new flow. */
		error = -ENOENT;
		if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
817
			goto err_unlock_ovs;
818 819 820 821 822

		/* Allocate flow. */
		flow = ovs_flow_alloc();
		if (IS_ERR(flow)) {
			error = PTR_ERR(flow);
823
			goto err_unlock_ovs;
824 825 826
		}
		clear_stats(flow);

827 828
		flow->key = masked_key;
		flow->unmasked_key = key;
829 830 831
		rcu_assign_pointer(flow->sf_acts, acts);

		/* Put flow in bucket. */
832 833 834 835 836
		error = ovs_flow_tbl_insert(&dp->table, flow, &mask);
		if (error) {
			acts = NULL;
			goto err_flow_free;
		}
837

838
		reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
839
						info->snd_seq, OVS_FLOW_CMD_NEW);
840 841 842 843 844 845 846 847 848 849 850 851 852
	} else {
		/* We found a matching flow. */
		struct sw_flow_actions *old_acts;

		/* Bail out if we're not allowed to modify an existing flow.
		 * We accept NLM_F_CREATE in place of the intended NLM_F_EXCL
		 * because Generic Netlink treats the latter as a dump
		 * request.  We also accept NLM_F_EXCL in case that bug ever
		 * gets fixed.
		 */
		error = -EEXIST;
		if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW &&
		    info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
853
			goto err_unlock_ovs;
854

855 856
		/* The unmasked key has to be the same for flow updates. */
		error = -EINVAL;
857
		if (!ovs_flow_cmp_unmasked_key(flow, &match)) {
858 859 860 861
			OVS_NLERR("Flow modification message rejected, unmasked key does not match.\n");
			goto err_unlock_ovs;
		}

862
		/* Update actions. */
863
		old_acts = ovsl_dereference(flow->sf_acts);
864
		rcu_assign_pointer(flow->sf_acts, acts);
865
		ovs_nla_free_flow_actions(old_acts);
866

867
		reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
868 869 870 871 872 873 874 875 876
					       info->snd_seq, OVS_FLOW_CMD_NEW);

		/* Clear stats. */
		if (a[OVS_FLOW_ATTR_CLEAR]) {
			spin_lock_bh(&flow->lock);
			clear_stats(flow);
			spin_unlock_bh(&flow->lock);
		}
	}
877
	ovs_unlock();
878 879

	if (!IS_ERR(reply))
880
		ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
881
	else
882
		netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
883 884 885
				ovs_dp_flow_multicast_group.id, PTR_ERR(reply));
	return 0;

886 887
err_flow_free:
	ovs_flow_free(flow, false);
888 889
err_unlock_ovs:
	ovs_unlock();
890 891
err_kfree:
	kfree(acts);
892 893 894 895 896 897 898 899 900 901 902 903
error:
	return error;
}

static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
{
	struct nlattr **a = info->attrs;
	struct ovs_header *ovs_header = info->userhdr;
	struct sw_flow_key key;
	struct sk_buff *reply;
	struct sw_flow *flow;
	struct datapath *dp;
904
	struct sw_flow_match match;
905 906
	int err;

907 908
	if (!a[OVS_FLOW_ATTR_KEY]) {
		OVS_NLERR("Flow get message rejected, Key attribute missing.\n");
909
		return -EINVAL;
910 911 912
	}

	ovs_match_init(&match, &key, NULL);
913
	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
914 915 916
	if (err)
		return err;

917
	ovs_lock();
918
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
919 920 921 922
	if (!dp) {
		err = -ENODEV;
		goto unlock;
	}
923

924
	flow = __ovs_flow_tbl_lookup(&dp->table, &key);
925
	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
926 927 928
		err = -ENOENT;
		goto unlock;
	}
929

930
	reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
931
					info->snd_seq, OVS_FLOW_CMD_NEW);
932 933 934 935
	if (IS_ERR(reply)) {
		err = PTR_ERR(reply);
		goto unlock;
	}
936

937
	ovs_unlock();
938
	return genlmsg_reply(reply, info);
939 940 941
unlock:
	ovs_unlock();
	return err;
942 943 944 945 946 947 948 949 950 951
}

static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info)
{
	struct nlattr **a = info->attrs;
	struct ovs_header *ovs_header = info->userhdr;
	struct sw_flow_key key;
	struct sk_buff *reply;
	struct sw_flow *flow;
	struct datapath *dp;
952
	struct sw_flow_match match;
953 954
	int err;

955
	ovs_lock();
956
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
957 958 959 960
	if (!dp) {
		err = -ENODEV;
		goto unlock;
	}
961

962
	if (!a[OVS_FLOW_ATTR_KEY]) {
963
		err = ovs_flow_tbl_flush(&dp->table);
964 965
		goto unlock;
	}
966 967

	ovs_match_init(&match, &key, NULL);
968
	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
969
	if (err)
970
		goto unlock;
971

972
	flow = __ovs_flow_tbl_lookup(&dp->table, &key);
973
	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
974 975 976
		err = -ENOENT;
		goto unlock;
	}
977 978

	reply = ovs_flow_cmd_alloc_info(flow);
979 980 981 982
	if (!reply) {
		err = -ENOMEM;
		goto unlock;
	}
983

984
	ovs_flow_tbl_remove(&dp->table, flow);
985

986
	err = ovs_flow_cmd_fill_info(flow, dp, reply, info->snd_portid,
987 988 989
				     info->snd_seq, 0, OVS_FLOW_CMD_DEL);
	BUG_ON(err < 0);

990
	ovs_flow_free(flow, true);
991
	ovs_unlock();
992

993
	ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
994
	return 0;
995 996 997
unlock:
	ovs_unlock();
	return err;
998 999 1000 1001 1002
}

static int ovs_flow_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct ovs_header *ovs_header = genlmsg_data(nlmsg_data(cb->nlh));
1003
	struct table_instance *ti;
1004 1005
	struct datapath *dp;

1006
	rcu_read_lock();
1007
	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
1008
	if (!dp) {
1009
		rcu_read_unlock();
1010
		return -ENODEV;
1011
	}
1012

1013
	ti = rcu_dereference(dp->table.ti);
1014 1015 1016 1017 1018 1019
	for (;;) {
		struct sw_flow *flow;
		u32 bucket, obj;

		bucket = cb->args[0];
		obj = cb->args[1];
1020
		flow = ovs_flow_tbl_dump_next(ti, &bucket, &obj);
1021 1022 1023 1024
		if (!flow)
			break;

		if (ovs_flow_cmd_fill_info(flow, dp, skb,
1025
					   NETLINK_CB(cb->skb).portid,
1026 1027 1028 1029 1030 1031 1032
					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
					   OVS_FLOW_CMD_NEW) < 0)
			break;

		cb->args[0] = bucket;
		cb->args[1] = obj;
	}
1033
	rcu_read_unlock();
1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070
	return skb->len;
}

static struct genl_ops dp_flow_genl_ops[] = {
	{ .cmd = OVS_FLOW_CMD_NEW,
	  .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
	  .policy = flow_policy,
	  .doit = ovs_flow_cmd_new_or_set
	},
	{ .cmd = OVS_FLOW_CMD_DEL,
	  .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
	  .policy = flow_policy,
	  .doit = ovs_flow_cmd_del
	},
	{ .cmd = OVS_FLOW_CMD_GET,
	  .flags = 0,		    /* OK for unprivileged users. */
	  .policy = flow_policy,
	  .doit = ovs_flow_cmd_get,
	  .dumpit = ovs_flow_cmd_dump
	},
	{ .cmd = OVS_FLOW_CMD_SET,
	  .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
	  .policy = flow_policy,
	  .doit = ovs_flow_cmd_new_or_set,
	},
};

static const struct nla_policy datapath_policy[OVS_DP_ATTR_MAX + 1] = {
	[OVS_DP_ATTR_NAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
	[OVS_DP_ATTR_UPCALL_PID] = { .type = NLA_U32 },
};

static struct genl_family dp_datapath_genl_family = {
	.id = GENL_ID_GENERATE,
	.hdrsize = sizeof(struct ovs_header),
	.name = OVS_DATAPATH_FAMILY,
	.version = OVS_DATAPATH_VERSION,
1071
	.maxattr = OVS_DP_ATTR_MAX,
1072 1073
	.netnsok = true,
	.parallel_ops = true,
1074 1075 1076 1077 1078 1079
};

static struct genl_multicast_group ovs_dp_datapath_multicast_group = {
	.name = OVS_DATAPATH_MCGROUP
};

1080 1081 1082 1083 1084 1085
static size_t ovs_dp_cmd_msg_size(void)
{
	size_t msgsize = NLMSG_ALIGN(sizeof(struct ovs_header));

	msgsize += nla_total_size(IFNAMSIZ);
	msgsize += nla_total_size(sizeof(struct ovs_dp_stats));
1086
	msgsize += nla_total_size(sizeof(struct ovs_dp_megaflow_stats));
1087 1088 1089 1090

	return msgsize;
}

1091
static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
1092
				u32 portid, u32 seq, u32 flags, u8 cmd)
1093 1094 1095
{
	struct ovs_header *ovs_header;
	struct ovs_dp_stats dp_stats;
1096
	struct ovs_dp_megaflow_stats dp_megaflow_stats;
1097 1098
	int err;

1099
	ovs_header = genlmsg_put(skb, portid, seq, &dp_datapath_genl_family,
1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
				   flags, cmd);
	if (!ovs_header)
		goto error;

	ovs_header->dp_ifindex = get_dpifindex(dp);

	rcu_read_lock();
	err = nla_put_string(skb, OVS_DP_ATTR_NAME, ovs_dp_name(dp));
	rcu_read_unlock();
	if (err)
		goto nla_put_failure;

1112 1113 1114 1115 1116 1117 1118 1119
	get_dp_stats(dp, &dp_stats, &dp_megaflow_stats);
	if (nla_put(skb, OVS_DP_ATTR_STATS, sizeof(struct ovs_dp_stats),
			&dp_stats))
		goto nla_put_failure;

	if (nla_put(skb, OVS_DP_ATTR_MEGAFLOW_STATS,
			sizeof(struct ovs_dp_megaflow_stats),
			&dp_megaflow_stats))
1120
		goto nla_put_failure;
1121 1122 1123 1124 1125 1126 1127 1128 1129

	return genlmsg_end(skb, ovs_header);

nla_put_failure:
	genlmsg_cancel(skb, ovs_header);
error:
	return -EMSGSIZE;
}