xref: /openbmc/linux/net/openvswitch/actions.c (revision 96de2506)
1 /*
2  * Copyright (c) 2007-2017 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/skbuff.h>
22 #include <linux/in.h>
23 #include <linux/ip.h>
24 #include <linux/openvswitch.h>
25 #include <linux/netfilter_ipv6.h>
26 #include <linux/sctp.h>
27 #include <linux/tcp.h>
28 #include <linux/udp.h>
29 #include <linux/in6.h>
30 #include <linux/if_arp.h>
31 #include <linux/if_vlan.h>
32 
33 #include <net/dst.h>
34 #include <net/ip.h>
35 #include <net/ipv6.h>
36 #include <net/ip6_fib.h>
37 #include <net/checksum.h>
38 #include <net/dsfield.h>
39 #include <net/mpls.h>
40 #include <net/sctp/checksum.h>
41 
42 #include "datapath.h"
43 #include "flow.h"
44 #include "conntrack.h"
45 #include "vport.h"
46 #include "flow_netlink.h"
47 
48 struct deferred_action {
49 	struct sk_buff *skb;
50 	const struct nlattr *actions;
51 	int actions_len;
52 
53 	/* Store pkt_key clone when creating deferred action. */
54 	struct sw_flow_key pkt_key;
55 };
56 
57 #define MAX_L2_LEN	(VLAN_ETH_HLEN + 3 * MPLS_HLEN)
58 struct ovs_frag_data {
59 	unsigned long dst;
60 	struct vport *vport;
61 	struct ovs_skb_cb cb;
62 	__be16 inner_protocol;
63 	u16 network_offset;	/* valid only for MPLS */
64 	u16 vlan_tci;
65 	__be16 vlan_proto;
66 	unsigned int l2_len;
67 	u8 mac_proto;
68 	u8 l2_data[MAX_L2_LEN];
69 };
70 
71 static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage);
72 
73 #define DEFERRED_ACTION_FIFO_SIZE 10
74 #define OVS_RECURSION_LIMIT 5
75 #define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2)
76 struct action_fifo {
77 	int head;
78 	int tail;
79 	/* Deferred action fifo queue storage. */
80 	struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
81 };
82 
83 struct action_flow_keys {
84 	struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD];
85 };
86 
87 static struct action_fifo __percpu *action_fifos;
88 static struct action_flow_keys __percpu *flow_keys;
89 static DEFINE_PER_CPU(int, exec_actions_level);
90 
91 /* Make a clone of the 'key', using the pre-allocated percpu 'flow_keys'
92  * space. Return NULL if out of key spaces.
93  */
94 static struct sw_flow_key *clone_key(const struct sw_flow_key *key_)
95 {
96 	struct action_flow_keys *keys = this_cpu_ptr(flow_keys);
97 	int level = this_cpu_read(exec_actions_level);
98 	struct sw_flow_key *key = NULL;
99 
100 	if (level <= OVS_DEFERRED_ACTION_THRESHOLD) {
101 		key = &keys->key[level - 1];
102 		*key = *key_;
103 	}
104 
105 	return key;
106 }
107 
108 static void action_fifo_init(struct action_fifo *fifo)
109 {
110 	fifo->head = 0;
111 	fifo->tail = 0;
112 }
113 
114 static bool action_fifo_is_empty(const struct action_fifo *fifo)
115 {
116 	return (fifo->head == fifo->tail);
117 }
118 
119 static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
120 {
121 	if (action_fifo_is_empty(fifo))
122 		return NULL;
123 
124 	return &fifo->fifo[fifo->tail++];
125 }
126 
127 static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
128 {
129 	if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
130 		return NULL;
131 
132 	return &fifo->fifo[fifo->head++];
133 }
134 
135 /* Return true if fifo is not full */
136 static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
137 				    const struct sw_flow_key *key,
138 				    const struct nlattr *actions,
139 				    const int actions_len)
140 {
141 	struct action_fifo *fifo;
142 	struct deferred_action *da;
143 
144 	fifo = this_cpu_ptr(action_fifos);
145 	da = action_fifo_put(fifo);
146 	if (da) {
147 		da->skb = skb;
148 		da->actions = actions;
149 		da->actions_len = actions_len;
150 		da->pkt_key = *key;
151 	}
152 
153 	return da;
154 }
155 
156 static void invalidate_flow_key(struct sw_flow_key *key)
157 {
158 	key->mac_proto |= SW_FLOW_KEY_INVALID;
159 }
160 
161 static bool is_flow_key_valid(const struct sw_flow_key *key)
162 {
163 	return !(key->mac_proto & SW_FLOW_KEY_INVALID);
164 }
165 
166 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
167 			 struct sw_flow_key *key,
168 			 u32 recirc_id,
169 			 const struct nlattr *actions, int len,
170 			 bool last, bool clone_flow_key);
171 
172 static void update_ethertype(struct sk_buff *skb, struct ethhdr *hdr,
173 			     __be16 ethertype)
174 {
175 	if (skb->ip_summed == CHECKSUM_COMPLETE) {
176 		__be16 diff[] = { ~(hdr->h_proto), ethertype };
177 
178 		skb->csum = ~csum_partial((char *)diff, sizeof(diff),
179 					~skb->csum);
180 	}
181 
182 	hdr->h_proto = ethertype;
183 }
184 
185 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
186 		     const struct ovs_action_push_mpls *mpls)
187 {
188 	struct mpls_shim_hdr *new_mpls_lse;
189 
190 	/* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
191 	if (skb->encapsulation)
192 		return -ENOTSUPP;
193 
194 	if (skb_cow_head(skb, MPLS_HLEN) < 0)
195 		return -ENOMEM;
196 
197 	if (!skb->inner_protocol) {
198 		skb_set_inner_network_header(skb, skb->mac_len);
199 		skb_set_inner_protocol(skb, skb->protocol);
200 	}
201 
202 	skb_push(skb, MPLS_HLEN);
203 	memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
204 		skb->mac_len);
205 	skb_reset_mac_header(skb);
206 	skb_set_network_header(skb, skb->mac_len);
207 
208 	new_mpls_lse = mpls_hdr(skb);
209 	new_mpls_lse->label_stack_entry = mpls->mpls_lse;
210 
211 	skb_postpush_rcsum(skb, new_mpls_lse, MPLS_HLEN);
212 
213 	if (ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET)
214 		update_ethertype(skb, eth_hdr(skb), mpls->mpls_ethertype);
215 	skb->protocol = mpls->mpls_ethertype;
216 
217 	invalidate_flow_key(key);
218 	return 0;
219 }
220 
221 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
222 		    const __be16 ethertype)
223 {
224 	int err;
225 
226 	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
227 	if (unlikely(err))
228 		return err;
229 
230 	skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN);
231 
232 	memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
233 		skb->mac_len);
234 
235 	__skb_pull(skb, MPLS_HLEN);
236 	skb_reset_mac_header(skb);
237 	skb_set_network_header(skb, skb->mac_len);
238 
239 	if (ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET) {
240 		struct ethhdr *hdr;
241 
242 		/* mpls_hdr() is used to locate the ethertype field correctly in the
243 		 * presence of VLAN tags.
244 		 */
245 		hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN);
246 		update_ethertype(skb, hdr, ethertype);
247 	}
248 	if (eth_p_mpls(skb->protocol))
249 		skb->protocol = ethertype;
250 
251 	invalidate_flow_key(key);
252 	return 0;
253 }
254 
255 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
256 		    const __be32 *mpls_lse, const __be32 *mask)
257 {
258 	struct mpls_shim_hdr *stack;
259 	__be32 lse;
260 	int err;
261 
262 	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
263 	if (unlikely(err))
264 		return err;
265 
266 	stack = mpls_hdr(skb);
267 	lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
268 	if (skb->ip_summed == CHECKSUM_COMPLETE) {
269 		__be32 diff[] = { ~(stack->label_stack_entry), lse };
270 
271 		skb->csum = ~csum_partial((char *)diff, sizeof(diff),
272 					  ~skb->csum);
273 	}
274 
275 	stack->label_stack_entry = lse;
276 	flow_key->mpls.top_lse = lse;
277 	return 0;
278 }
279 
280 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
281 {
282 	int err;
283 
284 	err = skb_vlan_pop(skb);
285 	if (skb_vlan_tag_present(skb)) {
286 		invalidate_flow_key(key);
287 	} else {
288 		key->eth.vlan.tci = 0;
289 		key->eth.vlan.tpid = 0;
290 	}
291 	return err;
292 }
293 
294 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
295 		     const struct ovs_action_push_vlan *vlan)
296 {
297 	if (skb_vlan_tag_present(skb)) {
298 		invalidate_flow_key(key);
299 	} else {
300 		key->eth.vlan.tci = vlan->vlan_tci;
301 		key->eth.vlan.tpid = vlan->vlan_tpid;
302 	}
303 	return skb_vlan_push(skb, vlan->vlan_tpid,
304 			     ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
305 }
306 
307 /* 'src' is already properly masked. */
308 static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
309 {
310 	u16 *dst = (u16 *)dst_;
311 	const u16 *src = (const u16 *)src_;
312 	const u16 *mask = (const u16 *)mask_;
313 
314 	OVS_SET_MASKED(dst[0], src[0], mask[0]);
315 	OVS_SET_MASKED(dst[1], src[1], mask[1]);
316 	OVS_SET_MASKED(dst[2], src[2], mask[2]);
317 }
318 
319 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
320 			const struct ovs_key_ethernet *key,
321 			const struct ovs_key_ethernet *mask)
322 {
323 	int err;
324 
325 	err = skb_ensure_writable(skb, ETH_HLEN);
326 	if (unlikely(err))
327 		return err;
328 
329 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
330 
331 	ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
332 			       mask->eth_src);
333 	ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
334 			       mask->eth_dst);
335 
336 	skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
337 
338 	ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
339 	ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
340 	return 0;
341 }
342 
343 /* pop_eth does not support VLAN packets as this action is never called
344  * for them.
345  */
346 static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key)
347 {
348 	skb_pull_rcsum(skb, ETH_HLEN);
349 	skb_reset_mac_header(skb);
350 	skb_reset_mac_len(skb);
351 
352 	/* safe right before invalidate_flow_key */
353 	key->mac_proto = MAC_PROTO_NONE;
354 	invalidate_flow_key(key);
355 	return 0;
356 }
357 
358 static int push_eth(struct sk_buff *skb, struct sw_flow_key *key,
359 		    const struct ovs_action_push_eth *ethh)
360 {
361 	struct ethhdr *hdr;
362 
363 	/* Add the new Ethernet header */
364 	if (skb_cow_head(skb, ETH_HLEN) < 0)
365 		return -ENOMEM;
366 
367 	skb_push(skb, ETH_HLEN);
368 	skb_reset_mac_header(skb);
369 	skb_reset_mac_len(skb);
370 
371 	hdr = eth_hdr(skb);
372 	ether_addr_copy(hdr->h_source, ethh->addresses.eth_src);
373 	ether_addr_copy(hdr->h_dest, ethh->addresses.eth_dst);
374 	hdr->h_proto = skb->protocol;
375 
376 	skb_postpush_rcsum(skb, hdr, ETH_HLEN);
377 
378 	/* safe right before invalidate_flow_key */
379 	key->mac_proto = MAC_PROTO_ETHERNET;
380 	invalidate_flow_key(key);
381 	return 0;
382 }
383 
384 static int push_nsh(struct sk_buff *skb, struct sw_flow_key *key,
385 		    const struct nshhdr *nh)
386 {
387 	int err;
388 
389 	err = nsh_push(skb, nh);
390 	if (err)
391 		return err;
392 
393 	/* safe right before invalidate_flow_key */
394 	key->mac_proto = MAC_PROTO_NONE;
395 	invalidate_flow_key(key);
396 	return 0;
397 }
398 
399 static int pop_nsh(struct sk_buff *skb, struct sw_flow_key *key)
400 {
401 	int err;
402 
403 	err = nsh_pop(skb);
404 	if (err)
405 		return err;
406 
407 	/* safe right before invalidate_flow_key */
408 	if (skb->protocol == htons(ETH_P_TEB))
409 		key->mac_proto = MAC_PROTO_ETHERNET;
410 	else
411 		key->mac_proto = MAC_PROTO_NONE;
412 	invalidate_flow_key(key);
413 	return 0;
414 }
415 
416 static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
417 				  __be32 addr, __be32 new_addr)
418 {
419 	int transport_len = skb->len - skb_transport_offset(skb);
420 
421 	if (nh->frag_off & htons(IP_OFFSET))
422 		return;
423 
424 	if (nh->protocol == IPPROTO_TCP) {
425 		if (likely(transport_len >= sizeof(struct tcphdr)))
426 			inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
427 						 addr, new_addr, true);
428 	} else if (nh->protocol == IPPROTO_UDP) {
429 		if (likely(transport_len >= sizeof(struct udphdr))) {
430 			struct udphdr *uh = udp_hdr(skb);
431 
432 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
433 				inet_proto_csum_replace4(&uh->check, skb,
434 							 addr, new_addr, true);
435 				if (!uh->check)
436 					uh->check = CSUM_MANGLED_0;
437 			}
438 		}
439 	}
440 }
441 
442 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
443 			__be32 *addr, __be32 new_addr)
444 {
445 	update_ip_l4_checksum(skb, nh, *addr, new_addr);
446 	csum_replace4(&nh->check, *addr, new_addr);
447 	skb_clear_hash(skb);
448 	*addr = new_addr;
449 }
450 
451 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
452 				 __be32 addr[4], const __be32 new_addr[4])
453 {
454 	int transport_len = skb->len - skb_transport_offset(skb);
455 
456 	if (l4_proto == NEXTHDR_TCP) {
457 		if (likely(transport_len >= sizeof(struct tcphdr)))
458 			inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
459 						  addr, new_addr, true);
460 	} else if (l4_proto == NEXTHDR_UDP) {
461 		if (likely(transport_len >= sizeof(struct udphdr))) {
462 			struct udphdr *uh = udp_hdr(skb);
463 
464 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
465 				inet_proto_csum_replace16(&uh->check, skb,
466 							  addr, new_addr, true);
467 				if (!uh->check)
468 					uh->check = CSUM_MANGLED_0;
469 			}
470 		}
471 	} else if (l4_proto == NEXTHDR_ICMP) {
472 		if (likely(transport_len >= sizeof(struct icmp6hdr)))
473 			inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
474 						  skb, addr, new_addr, true);
475 	}
476 }
477 
478 static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
479 			   const __be32 mask[4], __be32 masked[4])
480 {
481 	masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
482 	masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
483 	masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
484 	masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
485 }
486 
487 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
488 			  __be32 addr[4], const __be32 new_addr[4],
489 			  bool recalculate_csum)
490 {
491 	if (recalculate_csum)
492 		update_ipv6_checksum(skb, l4_proto, addr, new_addr);
493 
494 	skb_clear_hash(skb);
495 	memcpy(addr, new_addr, sizeof(__be32[4]));
496 }
497 
498 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
499 {
500 	/* Bits 21-24 are always unmasked, so this retains their values. */
501 	OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
502 	OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
503 	OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
504 }
505 
506 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
507 		       u8 mask)
508 {
509 	new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);
510 
511 	csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
512 	nh->ttl = new_ttl;
513 }
514 
515 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
516 		    const struct ovs_key_ipv4 *key,
517 		    const struct ovs_key_ipv4 *mask)
518 {
519 	struct iphdr *nh;
520 	__be32 new_addr;
521 	int err;
522 
523 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
524 				  sizeof(struct iphdr));
525 	if (unlikely(err))
526 		return err;
527 
528 	nh = ip_hdr(skb);
529 
530 	/* Setting an IP addresses is typically only a side effect of
531 	 * matching on them in the current userspace implementation, so it
532 	 * makes sense to check if the value actually changed.
533 	 */
534 	if (mask->ipv4_src) {
535 		new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
536 
537 		if (unlikely(new_addr != nh->saddr)) {
538 			set_ip_addr(skb, nh, &nh->saddr, new_addr);
539 			flow_key->ipv4.addr.src = new_addr;
540 		}
541 	}
542 	if (mask->ipv4_dst) {
543 		new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
544 
545 		if (unlikely(new_addr != nh->daddr)) {
546 			set_ip_addr(skb, nh, &nh->daddr, new_addr);
547 			flow_key->ipv4.addr.dst = new_addr;
548 		}
549 	}
550 	if (mask->ipv4_tos) {
551 		ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
552 		flow_key->ip.tos = nh->tos;
553 	}
554 	if (mask->ipv4_ttl) {
555 		set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
556 		flow_key->ip.ttl = nh->ttl;
557 	}
558 
559 	return 0;
560 }
561 
562 static bool is_ipv6_mask_nonzero(const __be32 addr[4])
563 {
564 	return !!(addr[0] | addr[1] | addr[2] | addr[3]);
565 }
566 
567 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
568 		    const struct ovs_key_ipv6 *key,
569 		    const struct ovs_key_ipv6 *mask)
570 {
571 	struct ipv6hdr *nh;
572 	int err;
573 
574 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
575 				  sizeof(struct ipv6hdr));
576 	if (unlikely(err))
577 		return err;
578 
579 	nh = ipv6_hdr(skb);
580 
581 	/* Setting an IP addresses is typically only a side effect of
582 	 * matching on them in the current userspace implementation, so it
583 	 * makes sense to check if the value actually changed.
584 	 */
585 	if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
586 		__be32 *saddr = (__be32 *)&nh->saddr;
587 		__be32 masked[4];
588 
589 		mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
590 
591 		if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
592 			set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
593 				      true);
594 			memcpy(&flow_key->ipv6.addr.src, masked,
595 			       sizeof(flow_key->ipv6.addr.src));
596 		}
597 	}
598 	if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
599 		unsigned int offset = 0;
600 		int flags = IP6_FH_F_SKIP_RH;
601 		bool recalc_csum = true;
602 		__be32 *daddr = (__be32 *)&nh->daddr;
603 		__be32 masked[4];
604 
605 		mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
606 
607 		if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
608 			if (ipv6_ext_hdr(nh->nexthdr))
609 				recalc_csum = (ipv6_find_hdr(skb, &offset,
610 							     NEXTHDR_ROUTING,
611 							     NULL, &flags)
612 					       != NEXTHDR_ROUTING);
613 
614 			set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
615 				      recalc_csum);
616 			memcpy(&flow_key->ipv6.addr.dst, masked,
617 			       sizeof(flow_key->ipv6.addr.dst));
618 		}
619 	}
620 	if (mask->ipv6_tclass) {
621 		ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
622 		flow_key->ip.tos = ipv6_get_dsfield(nh);
623 	}
624 	if (mask->ipv6_label) {
625 		set_ipv6_fl(nh, ntohl(key->ipv6_label),
626 			    ntohl(mask->ipv6_label));
627 		flow_key->ipv6.label =
628 		    *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
629 	}
630 	if (mask->ipv6_hlimit) {
631 		OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit,
632 			       mask->ipv6_hlimit);
633 		flow_key->ip.ttl = nh->hop_limit;
634 	}
635 	return 0;
636 }
637 
638 static int set_nsh(struct sk_buff *skb, struct sw_flow_key *flow_key,
639 		   const struct nlattr *a)
640 {
641 	struct nshhdr *nh;
642 	size_t length;
643 	int err;
644 	u8 flags;
645 	u8 ttl;
646 	int i;
647 
648 	struct ovs_key_nsh key;
649 	struct ovs_key_nsh mask;
650 
651 	err = nsh_key_from_nlattr(a, &key, &mask);
652 	if (err)
653 		return err;
654 
655 	/* Make sure the NSH base header is there */
656 	if (!pskb_may_pull(skb, skb_network_offset(skb) + NSH_BASE_HDR_LEN))
657 		return -ENOMEM;
658 
659 	nh = nsh_hdr(skb);
660 	length = nsh_hdr_len(nh);
661 
662 	/* Make sure the whole NSH header is there */
663 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
664 				       length);
665 	if (unlikely(err))
666 		return err;
667 
668 	nh = nsh_hdr(skb);
669 	skb_postpull_rcsum(skb, nh, length);
670 	flags = nsh_get_flags(nh);
671 	flags = OVS_MASKED(flags, key.base.flags, mask.base.flags);
672 	flow_key->nsh.base.flags = flags;
673 	ttl = nsh_get_ttl(nh);
674 	ttl = OVS_MASKED(ttl, key.base.ttl, mask.base.ttl);
675 	flow_key->nsh.base.ttl = ttl;
676 	nsh_set_flags_and_ttl(nh, flags, ttl);
677 	nh->path_hdr = OVS_MASKED(nh->path_hdr, key.base.path_hdr,
678 				  mask.base.path_hdr);
679 	flow_key->nsh.base.path_hdr = nh->path_hdr;
680 	switch (nh->mdtype) {
681 	case NSH_M_TYPE1:
682 		for (i = 0; i < NSH_MD1_CONTEXT_SIZE; i++) {
683 			nh->md1.context[i] =
684 			    OVS_MASKED(nh->md1.context[i], key.context[i],
685 				       mask.context[i]);
686 		}
687 		memcpy(flow_key->nsh.context, nh->md1.context,
688 		       sizeof(nh->md1.context));
689 		break;
690 	case NSH_M_TYPE2:
691 		memset(flow_key->nsh.context, 0,
692 		       sizeof(flow_key->nsh.context));
693 		break;
694 	default:
695 		return -EINVAL;
696 	}
697 	skb_postpush_rcsum(skb, nh, length);
698 	return 0;
699 }
700 
701 /* Must follow skb_ensure_writable() since that can move the skb data. */
702 static void set_tp_port(struct sk_buff *skb, __be16 *port,
703 			__be16 new_port, __sum16 *check)
704 {
705 	inet_proto_csum_replace2(check, skb, *port, new_port, false);
706 	*port = new_port;
707 }
708 
709 static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
710 		   const struct ovs_key_udp *key,
711 		   const struct ovs_key_udp *mask)
712 {
713 	struct udphdr *uh;
714 	__be16 src, dst;
715 	int err;
716 
717 	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
718 				  sizeof(struct udphdr));
719 	if (unlikely(err))
720 		return err;
721 
722 	uh = udp_hdr(skb);
723 	/* Either of the masks is non-zero, so do not bother checking them. */
724 	src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src);
725 	dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst);
726 
727 	if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
728 		if (likely(src != uh->source)) {
729 			set_tp_port(skb, &uh->source, src, &uh->check);
730 			flow_key->tp.src = src;
731 		}
732 		if (likely(dst != uh->dest)) {
733 			set_tp_port(skb, &uh->dest, dst, &uh->check);
734 			flow_key->tp.dst = dst;
735 		}
736 
737 		if (unlikely(!uh->check))
738 			uh->check = CSUM_MANGLED_0;
739 	} else {
740 		uh->source = src;
741 		uh->dest = dst;
742 		flow_key->tp.src = src;
743 		flow_key->tp.dst = dst;
744 	}
745 
746 	skb_clear_hash(skb);
747 
748 	return 0;
749 }
750 
751 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
752 		   const struct ovs_key_tcp *key,
753 		   const struct ovs_key_tcp *mask)
754 {
755 	struct tcphdr *th;
756 	__be16 src, dst;
757 	int err;
758 
759 	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
760 				  sizeof(struct tcphdr));
761 	if (unlikely(err))
762 		return err;
763 
764 	th = tcp_hdr(skb);
765 	src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src);
766 	if (likely(src != th->source)) {
767 		set_tp_port(skb, &th->source, src, &th->check);
768 		flow_key->tp.src = src;
769 	}
770 	dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
771 	if (likely(dst != th->dest)) {
772 		set_tp_port(skb, &th->dest, dst, &th->check);
773 		flow_key->tp.dst = dst;
774 	}
775 	skb_clear_hash(skb);
776 
777 	return 0;
778 }
779 
780 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
781 		    const struct ovs_key_sctp *key,
782 		    const struct ovs_key_sctp *mask)
783 {
784 	unsigned int sctphoff = skb_transport_offset(skb);
785 	struct sctphdr *sh;
786 	__le32 old_correct_csum, new_csum, old_csum;
787 	int err;
788 
789 	err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
790 	if (unlikely(err))
791 		return err;
792 
793 	sh = sctp_hdr(skb);
794 	old_csum = sh->checksum;
795 	old_correct_csum = sctp_compute_cksum(skb, sctphoff);
796 
797 	sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src);
798 	sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
799 
800 	new_csum = sctp_compute_cksum(skb, sctphoff);
801 
802 	/* Carry any checksum errors through. */
803 	sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
804 
805 	skb_clear_hash(skb);
806 	flow_key->tp.src = sh->source;
807 	flow_key->tp.dst = sh->dest;
808 
809 	return 0;
810 }
811 
812 static int ovs_vport_output(struct net *net, struct sock *sk, struct sk_buff *skb)
813 {
814 	struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
815 	struct vport *vport = data->vport;
816 
817 	if (skb_cow_head(skb, data->l2_len) < 0) {
818 		kfree_skb(skb);
819 		return -ENOMEM;
820 	}
821 
822 	__skb_dst_copy(skb, data->dst);
823 	*OVS_CB(skb) = data->cb;
824 	skb->inner_protocol = data->inner_protocol;
825 	skb->vlan_tci = data->vlan_tci;
826 	skb->vlan_proto = data->vlan_proto;
827 
828 	/* Reconstruct the MAC header.  */
829 	skb_push(skb, data->l2_len);
830 	memcpy(skb->data, &data->l2_data, data->l2_len);
831 	skb_postpush_rcsum(skb, skb->data, data->l2_len);
832 	skb_reset_mac_header(skb);
833 
834 	if (eth_p_mpls(skb->protocol)) {
835 		skb->inner_network_header = skb->network_header;
836 		skb_set_network_header(skb, data->network_offset);
837 		skb_reset_mac_len(skb);
838 	}
839 
840 	ovs_vport_send(vport, skb, data->mac_proto);
841 	return 0;
842 }
843 
844 static unsigned int
845 ovs_dst_get_mtu(const struct dst_entry *dst)
846 {
847 	return dst->dev->mtu;
848 }
849 
850 static struct dst_ops ovs_dst_ops = {
851 	.family = AF_UNSPEC,
852 	.mtu = ovs_dst_get_mtu,
853 };
854 
855 /* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
856  * ovs_vport_output(), which is called once per fragmented packet.
857  */
858 static void prepare_frag(struct vport *vport, struct sk_buff *skb,
859 			 u16 orig_network_offset, u8 mac_proto)
860 {
861 	unsigned int hlen = skb_network_offset(skb);
862 	struct ovs_frag_data *data;
863 
864 	data = this_cpu_ptr(&ovs_frag_data_storage);
865 	data->dst = skb->_skb_refdst;
866 	data->vport = vport;
867 	data->cb = *OVS_CB(skb);
868 	data->inner_protocol = skb->inner_protocol;
869 	data->network_offset = orig_network_offset;
870 	data->vlan_tci = skb->vlan_tci;
871 	data->vlan_proto = skb->vlan_proto;
872 	data->mac_proto = mac_proto;
873 	data->l2_len = hlen;
874 	memcpy(&data->l2_data, skb->data, hlen);
875 
876 	memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
877 	skb_pull(skb, hlen);
878 }
879 
880 static void ovs_fragment(struct net *net, struct vport *vport,
881 			 struct sk_buff *skb, u16 mru,
882 			 struct sw_flow_key *key)
883 {
884 	u16 orig_network_offset = 0;
885 
886 	if (eth_p_mpls(skb->protocol)) {
887 		orig_network_offset = skb_network_offset(skb);
888 		skb->network_header = skb->inner_network_header;
889 	}
890 
891 	if (skb_network_offset(skb) > MAX_L2_LEN) {
892 		OVS_NLERR(1, "L2 header too long to fragment");
893 		goto err;
894 	}
895 
896 	if (key->eth.type == htons(ETH_P_IP)) {
897 		struct dst_entry ovs_dst;
898 		unsigned long orig_dst;
899 
900 		prepare_frag(vport, skb, orig_network_offset,
901 			     ovs_key_mac_proto(key));
902 		dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
903 			 DST_OBSOLETE_NONE, DST_NOCOUNT);
904 		ovs_dst.dev = vport->dev;
905 
906 		orig_dst = skb->_skb_refdst;
907 		skb_dst_set_noref(skb, &ovs_dst);
908 		IPCB(skb)->frag_max_size = mru;
909 
910 		ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
911 		refdst_drop(orig_dst);
912 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
913 		const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
914 		unsigned long orig_dst;
915 		struct rt6_info ovs_rt;
916 
917 		if (!v6ops)
918 			goto err;
919 
920 		prepare_frag(vport, skb, orig_network_offset,
921 			     ovs_key_mac_proto(key));
922 		memset(&ovs_rt, 0, sizeof(ovs_rt));
923 		dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
924 			 DST_OBSOLETE_NONE, DST_NOCOUNT);
925 		ovs_rt.dst.dev = vport->dev;
926 
927 		orig_dst = skb->_skb_refdst;
928 		skb_dst_set_noref(skb, &ovs_rt.dst);
929 		IP6CB(skb)->frag_max_size = mru;
930 
931 		v6ops->fragment(net, skb->sk, skb, ovs_vport_output);
932 		refdst_drop(orig_dst);
933 	} else {
934 		WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
935 			  ovs_vport_name(vport), ntohs(key->eth.type), mru,
936 			  vport->dev->mtu);
937 		goto err;
938 	}
939 
940 	return;
941 err:
942 	kfree_skb(skb);
943 }
944 
945 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
946 		      struct sw_flow_key *key)
947 {
948 	struct vport *vport = ovs_vport_rcu(dp, out_port);
949 
950 	if (likely(vport)) {
951 		u16 mru = OVS_CB(skb)->mru;
952 		u32 cutlen = OVS_CB(skb)->cutlen;
953 
954 		if (unlikely(cutlen > 0)) {
955 			if (skb->len - cutlen > ovs_mac_header_len(key))
956 				pskb_trim(skb, skb->len - cutlen);
957 			else
958 				pskb_trim(skb, ovs_mac_header_len(key));
959 		}
960 
961 		if (likely(!mru ||
962 		           (skb->len <= mru + vport->dev->hard_header_len))) {
963 			ovs_vport_send(vport, skb, ovs_key_mac_proto(key));
964 		} else if (mru <= vport->dev->mtu) {
965 			struct net *net = read_pnet(&dp->net);
966 
967 			ovs_fragment(net, vport, skb, mru, key);
968 		} else {
969 			kfree_skb(skb);
970 		}
971 	} else {
972 		kfree_skb(skb);
973 	}
974 }
975 
976 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
977 			    struct sw_flow_key *key, const struct nlattr *attr,
978 			    const struct nlattr *actions, int actions_len,
979 			    uint32_t cutlen)
980 {
981 	struct dp_upcall_info upcall;
982 	const struct nlattr *a;
983 	int rem;
984 
985 	memset(&upcall, 0, sizeof(upcall));
986 	upcall.cmd = OVS_PACKET_CMD_ACTION;
987 	upcall.mru = OVS_CB(skb)->mru;
988 
989 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
990 		 a = nla_next(a, &rem)) {
991 		switch (nla_type(a)) {
992 		case OVS_USERSPACE_ATTR_USERDATA:
993 			upcall.userdata = a;
994 			break;
995 
996 		case OVS_USERSPACE_ATTR_PID:
997 			upcall.portid = nla_get_u32(a);
998 			break;
999 
1000 		case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
1001 			/* Get out tunnel info. */
1002 			struct vport *vport;
1003 
1004 			vport = ovs_vport_rcu(dp, nla_get_u32(a));
1005 			if (vport) {
1006 				int err;
1007 
1008 				err = dev_fill_metadata_dst(vport->dev, skb);
1009 				if (!err)
1010 					upcall.egress_tun_info = skb_tunnel_info(skb);
1011 			}
1012 
1013 			break;
1014 		}
1015 
1016 		case OVS_USERSPACE_ATTR_ACTIONS: {
1017 			/* Include actions. */
1018 			upcall.actions = actions;
1019 			upcall.actions_len = actions_len;
1020 			break;
1021 		}
1022 
1023 		} /* End of switch. */
1024 	}
1025 
1026 	return ovs_dp_upcall(dp, skb, key, &upcall, cutlen);
1027 }
1028 
1029 /* When 'last' is true, sample() should always consume the 'skb'.
1030  * Otherwise, sample() should keep 'skb' intact regardless what
1031  * actions are executed within sample().
1032  */
1033 static int sample(struct datapath *dp, struct sk_buff *skb,
1034 		  struct sw_flow_key *key, const struct nlattr *attr,
1035 		  bool last)
1036 {
1037 	struct nlattr *actions;
1038 	struct nlattr *sample_arg;
1039 	int rem = nla_len(attr);
1040 	const struct sample_arg *arg;
1041 	bool clone_flow_key;
1042 
1043 	/* The first action is always 'OVS_SAMPLE_ATTR_ARG'. */
1044 	sample_arg = nla_data(attr);
1045 	arg = nla_data(sample_arg);
1046 	actions = nla_next(sample_arg, &rem);
1047 
1048 	if ((arg->probability != U32_MAX) &&
1049 	    (!arg->probability || prandom_u32() > arg->probability)) {
1050 		if (last)
1051 			consume_skb(skb);
1052 		return 0;
1053 	}
1054 
1055 	clone_flow_key = !arg->exec;
1056 	return clone_execute(dp, skb, key, 0, actions, rem, last,
1057 			     clone_flow_key);
1058 }
1059 
1060 /* When 'last' is true, clone() should always consume the 'skb'.
1061  * Otherwise, clone() should keep 'skb' intact regardless what
1062  * actions are executed within clone().
1063  */
1064 static int clone(struct datapath *dp, struct sk_buff *skb,
1065 		 struct sw_flow_key *key, const struct nlattr *attr,
1066 		 bool last)
1067 {
1068 	struct nlattr *actions;
1069 	struct nlattr *clone_arg;
1070 	int rem = nla_len(attr);
1071 	bool dont_clone_flow_key;
1072 
1073 	/* The first action is always 'OVS_CLONE_ATTR_ARG'. */
1074 	clone_arg = nla_data(attr);
1075 	dont_clone_flow_key = nla_get_u32(clone_arg);
1076 	actions = nla_next(clone_arg, &rem);
1077 
1078 	return clone_execute(dp, skb, key, 0, actions, rem, last,
1079 			     !dont_clone_flow_key);
1080 }
1081 
1082 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
1083 			 const struct nlattr *attr)
1084 {
1085 	struct ovs_action_hash *hash_act = nla_data(attr);
1086 	u32 hash = 0;
1087 
1088 	/* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
1089 	hash = skb_get_hash(skb);
1090 	hash = jhash_1word(hash, hash_act->hash_basis);
1091 	if (!hash)
1092 		hash = 0x1;
1093 
1094 	key->ovs_flow_hash = hash;
1095 }
1096 
1097 static int execute_set_action(struct sk_buff *skb,
1098 			      struct sw_flow_key *flow_key,
1099 			      const struct nlattr *a)
1100 {
1101 	/* Only tunnel set execution is supported without a mask. */
1102 	if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
1103 		struct ovs_tunnel_info *tun = nla_data(a);
1104 
1105 		skb_dst_drop(skb);
1106 		dst_hold((struct dst_entry *)tun->tun_dst);
1107 		skb_dst_set(skb, (struct dst_entry *)tun->tun_dst);
1108 		return 0;
1109 	}
1110 
1111 	return -EINVAL;
1112 }
1113 
1114 /* Mask is at the midpoint of the data. */
1115 #define get_mask(a, type) ((const type)nla_data(a) + 1)
1116 
1117 static int execute_masked_set_action(struct sk_buff *skb,
1118 				     struct sw_flow_key *flow_key,
1119 				     const struct nlattr *a)
1120 {
1121 	int err = 0;
1122 
1123 	switch (nla_type(a)) {
1124 	case OVS_KEY_ATTR_PRIORITY:
1125 		OVS_SET_MASKED(skb->priority, nla_get_u32(a),
1126 			       *get_mask(a, u32 *));
1127 		flow_key->phy.priority = skb->priority;
1128 		break;
1129 
1130 	case OVS_KEY_ATTR_SKB_MARK:
1131 		OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
1132 		flow_key->phy.skb_mark = skb->mark;
1133 		break;
1134 
1135 	case OVS_KEY_ATTR_TUNNEL_INFO:
1136 		/* Masked data not supported for tunnel. */
1137 		err = -EINVAL;
1138 		break;
1139 
1140 	case OVS_KEY_ATTR_ETHERNET:
1141 		err = set_eth_addr(skb, flow_key, nla_data(a),
1142 				   get_mask(a, struct ovs_key_ethernet *));
1143 		break;
1144 
1145 	case OVS_KEY_ATTR_NSH:
1146 		err = set_nsh(skb, flow_key, a);
1147 		break;
1148 
1149 	case OVS_KEY_ATTR_IPV4:
1150 		err = set_ipv4(skb, flow_key, nla_data(a),
1151 			       get_mask(a, struct ovs_key_ipv4 *));
1152 		break;
1153 
1154 	case OVS_KEY_ATTR_IPV6:
1155 		err = set_ipv6(skb, flow_key, nla_data(a),
1156 			       get_mask(a, struct ovs_key_ipv6 *));
1157 		break;
1158 
1159 	case OVS_KEY_ATTR_TCP:
1160 		err = set_tcp(skb, flow_key, nla_data(a),
1161 			      get_mask(a, struct ovs_key_tcp *));
1162 		break;
1163 
1164 	case OVS_KEY_ATTR_UDP:
1165 		err = set_udp(skb, flow_key, nla_data(a),
1166 			      get_mask(a, struct ovs_key_udp *));
1167 		break;
1168 
1169 	case OVS_KEY_ATTR_SCTP:
1170 		err = set_sctp(skb, flow_key, nla_data(a),
1171 			       get_mask(a, struct ovs_key_sctp *));
1172 		break;
1173 
1174 	case OVS_KEY_ATTR_MPLS:
1175 		err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
1176 								    __be32 *));
1177 		break;
1178 
1179 	case OVS_KEY_ATTR_CT_STATE:
1180 	case OVS_KEY_ATTR_CT_ZONE:
1181 	case OVS_KEY_ATTR_CT_MARK:
1182 	case OVS_KEY_ATTR_CT_LABELS:
1183 	case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4:
1184 	case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6:
1185 		err = -EINVAL;
1186 		break;
1187 	}
1188 
1189 	return err;
1190 }
1191 
1192 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
1193 			  struct sw_flow_key *key,
1194 			  const struct nlattr *a, bool last)
1195 {
1196 	u32 recirc_id;
1197 
1198 	if (!is_flow_key_valid(key)) {
1199 		int err;
1200 
1201 		err = ovs_flow_key_update(skb, key);
1202 		if (err)
1203 			return err;
1204 	}
1205 	BUG_ON(!is_flow_key_valid(key));
1206 
1207 	recirc_id = nla_get_u32(a);
1208 	return clone_execute(dp, skb, key, recirc_id, NULL, 0, last, true);
1209 }
1210 
1211 /* Execute a list of actions against 'skb'. */
1212 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
1213 			      struct sw_flow_key *key,
1214 			      const struct nlattr *attr, int len)
1215 {
1216 	const struct nlattr *a;
1217 	int rem;
1218 
1219 	for (a = attr, rem = len; rem > 0;
1220 	     a = nla_next(a, &rem)) {
1221 		int err = 0;
1222 
1223 		switch (nla_type(a)) {
1224 		case OVS_ACTION_ATTR_OUTPUT: {
1225 			int port = nla_get_u32(a);
1226 			struct sk_buff *clone;
1227 
1228 			/* Every output action needs a separate clone
1229 			 * of 'skb', In case the output action is the
1230 			 * last action, cloning can be avoided.
1231 			 */
1232 			if (nla_is_last(a, rem)) {
1233 				do_output(dp, skb, port, key);
1234 				/* 'skb' has been used for output.
1235 				 */
1236 				return 0;
1237 			}
1238 
1239 			clone = skb_clone(skb, GFP_ATOMIC);
1240 			if (clone)
1241 				do_output(dp, clone, port, key);
1242 			OVS_CB(skb)->cutlen = 0;
1243 			break;
1244 		}
1245 
1246 		case OVS_ACTION_ATTR_TRUNC: {
1247 			struct ovs_action_trunc *trunc = nla_data(a);
1248 
1249 			if (skb->len > trunc->max_len)
1250 				OVS_CB(skb)->cutlen = skb->len - trunc->max_len;
1251 			break;
1252 		}
1253 
1254 		case OVS_ACTION_ATTR_USERSPACE:
1255 			output_userspace(dp, skb, key, a, attr,
1256 						     len, OVS_CB(skb)->cutlen);
1257 			OVS_CB(skb)->cutlen = 0;
1258 			break;
1259 
1260 		case OVS_ACTION_ATTR_HASH:
1261 			execute_hash(skb, key, a);
1262 			break;
1263 
1264 		case OVS_ACTION_ATTR_PUSH_MPLS:
1265 			err = push_mpls(skb, key, nla_data(a));
1266 			break;
1267 
1268 		case OVS_ACTION_ATTR_POP_MPLS:
1269 			err = pop_mpls(skb, key, nla_get_be16(a));
1270 			break;
1271 
1272 		case OVS_ACTION_ATTR_PUSH_VLAN:
1273 			err = push_vlan(skb, key, nla_data(a));
1274 			break;
1275 
1276 		case OVS_ACTION_ATTR_POP_VLAN:
1277 			err = pop_vlan(skb, key);
1278 			break;
1279 
1280 		case OVS_ACTION_ATTR_RECIRC: {
1281 			bool last = nla_is_last(a, rem);
1282 
1283 			err = execute_recirc(dp, skb, key, a, last);
1284 			if (last) {
1285 				/* If this is the last action, the skb has
1286 				 * been consumed or freed.
1287 				 * Return immediately.
1288 				 */
1289 				return err;
1290 			}
1291 			break;
1292 		}
1293 
1294 		case OVS_ACTION_ATTR_SET:
1295 			err = execute_set_action(skb, key, nla_data(a));
1296 			break;
1297 
1298 		case OVS_ACTION_ATTR_SET_MASKED:
1299 		case OVS_ACTION_ATTR_SET_TO_MASKED:
1300 			err = execute_masked_set_action(skb, key, nla_data(a));
1301 			break;
1302 
1303 		case OVS_ACTION_ATTR_SAMPLE: {
1304 			bool last = nla_is_last(a, rem);
1305 
1306 			err = sample(dp, skb, key, a, last);
1307 			if (last)
1308 				return err;
1309 
1310 			break;
1311 		}
1312 
1313 		case OVS_ACTION_ATTR_CT:
1314 			if (!is_flow_key_valid(key)) {
1315 				err = ovs_flow_key_update(skb, key);
1316 				if (err)
1317 					return err;
1318 			}
1319 
1320 			err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
1321 					     nla_data(a));
1322 
1323 			/* Hide stolen IP fragments from user space. */
1324 			if (err)
1325 				return err == -EINPROGRESS ? 0 : err;
1326 			break;
1327 
1328 		case OVS_ACTION_ATTR_CT_CLEAR:
1329 			err = ovs_ct_clear(skb, key);
1330 			break;
1331 
1332 		case OVS_ACTION_ATTR_PUSH_ETH:
1333 			err = push_eth(skb, key, nla_data(a));
1334 			break;
1335 
1336 		case OVS_ACTION_ATTR_POP_ETH:
1337 			err = pop_eth(skb, key);
1338 			break;
1339 
1340 		case OVS_ACTION_ATTR_PUSH_NSH: {
1341 			u8 buffer[NSH_HDR_MAX_LEN];
1342 			struct nshhdr *nh = (struct nshhdr *)buffer;
1343 
1344 			err = nsh_hdr_from_nlattr(nla_data(a), nh,
1345 						  NSH_HDR_MAX_LEN);
1346 			if (unlikely(err))
1347 				break;
1348 			err = push_nsh(skb, key, nh);
1349 			break;
1350 		}
1351 
1352 		case OVS_ACTION_ATTR_POP_NSH:
1353 			err = pop_nsh(skb, key);
1354 			break;
1355 
1356 		case OVS_ACTION_ATTR_METER:
1357 			if (ovs_meter_execute(dp, skb, key, nla_get_u32(a))) {
1358 				consume_skb(skb);
1359 				return 0;
1360 			}
1361 			break;
1362 
1363 		case OVS_ACTION_ATTR_CLONE: {
1364 			bool last = nla_is_last(a, rem);
1365 
1366 			err = clone(dp, skb, key, a, last);
1367 			if (last)
1368 				return err;
1369 
1370 			break;
1371 		}
1372 		}
1373 
1374 		if (unlikely(err)) {
1375 			kfree_skb(skb);
1376 			return err;
1377 		}
1378 	}
1379 
1380 	consume_skb(skb);
1381 	return 0;
1382 }
1383 
1384 /* Execute the actions on the clone of the packet. The effect of the
1385  * execution does not affect the original 'skb' nor the original 'key'.
1386  *
1387  * The execution may be deferred in case the actions can not be executed
1388  * immediately.
1389  */
1390 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
1391 			 struct sw_flow_key *key, u32 recirc_id,
1392 			 const struct nlattr *actions, int len,
1393 			 bool last, bool clone_flow_key)
1394 {
1395 	struct deferred_action *da;
1396 	struct sw_flow_key *clone;
1397 
1398 	skb = last ? skb : skb_clone(skb, GFP_ATOMIC);
1399 	if (!skb) {
1400 		/* Out of memory, skip this action.
1401 		 */
1402 		return 0;
1403 	}
1404 
1405 	/* When clone_flow_key is false, the 'key' will not be change
1406 	 * by the actions, then the 'key' can be used directly.
1407 	 * Otherwise, try to clone key from the next recursion level of
1408 	 * 'flow_keys'. If clone is successful, execute the actions
1409 	 * without deferring.
1410 	 */
1411 	clone = clone_flow_key ? clone_key(key) : key;
1412 	if (clone) {
1413 		int err = 0;
1414 
1415 		if (actions) { /* Sample action */
1416 			if (clone_flow_key)
1417 				__this_cpu_inc(exec_actions_level);
1418 
1419 			err = do_execute_actions(dp, skb, clone,
1420 						 actions, len);
1421 
1422 			if (clone_flow_key)
1423 				__this_cpu_dec(exec_actions_level);
1424 		} else { /* Recirc action */
1425 			clone->recirc_id = recirc_id;
1426 			ovs_dp_process_packet(skb, clone);
1427 		}
1428 		return err;
1429 	}
1430 
1431 	/* Out of 'flow_keys' space. Defer actions */
1432 	da = add_deferred_actions(skb, key, actions, len);
1433 	if (da) {
1434 		if (!actions) { /* Recirc action */
1435 			key = &da->pkt_key;
1436 			key->recirc_id = recirc_id;
1437 		}
1438 	} else {
1439 		/* Out of per CPU action FIFO space. Drop the 'skb' and
1440 		 * log an error.
1441 		 */
1442 		kfree_skb(skb);
1443 
1444 		if (net_ratelimit()) {
1445 			if (actions) { /* Sample action */
1446 				pr_warn("%s: deferred action limit reached, drop sample action\n",
1447 					ovs_dp_name(dp));
1448 			} else {  /* Recirc action */
1449 				pr_warn("%s: deferred action limit reached, drop recirc action\n",
1450 					ovs_dp_name(dp));
1451 			}
1452 		}
1453 	}
1454 	return 0;
1455 }
1456 
1457 static void process_deferred_actions(struct datapath *dp)
1458 {
1459 	struct action_fifo *fifo = this_cpu_ptr(action_fifos);
1460 
1461 	/* Do not touch the FIFO in case there is no deferred actions. */
1462 	if (action_fifo_is_empty(fifo))
1463 		return;
1464 
1465 	/* Finishing executing all deferred actions. */
1466 	do {
1467 		struct deferred_action *da = action_fifo_get(fifo);
1468 		struct sk_buff *skb = da->skb;
1469 		struct sw_flow_key *key = &da->pkt_key;
1470 		const struct nlattr *actions = da->actions;
1471 		int actions_len = da->actions_len;
1472 
1473 		if (actions)
1474 			do_execute_actions(dp, skb, key, actions, actions_len);
1475 		else
1476 			ovs_dp_process_packet(skb, key);
1477 	} while (!action_fifo_is_empty(fifo));
1478 
1479 	/* Reset FIFO for the next packet.  */
1480 	action_fifo_init(fifo);
1481 }
1482 
1483 /* Execute a list of actions against 'skb'. */
1484 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
1485 			const struct sw_flow_actions *acts,
1486 			struct sw_flow_key *key)
1487 {
1488 	int err, level;
1489 
1490 	level = __this_cpu_inc_return(exec_actions_level);
1491 	if (unlikely(level > OVS_RECURSION_LIMIT)) {
1492 		net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n",
1493 				     ovs_dp_name(dp));
1494 		kfree_skb(skb);
1495 		err = -ENETDOWN;
1496 		goto out;
1497 	}
1498 
1499 	OVS_CB(skb)->acts_origlen = acts->orig_len;
1500 	err = do_execute_actions(dp, skb, key,
1501 				 acts->actions, acts->actions_len);
1502 
1503 	if (level == 1)
1504 		process_deferred_actions(dp);
1505 
1506 out:
1507 	__this_cpu_dec(exec_actions_level);
1508 	return err;
1509 }
1510 
1511 int action_fifos_init(void)
1512 {
1513 	action_fifos = alloc_percpu(struct action_fifo);
1514 	if (!action_fifos)
1515 		return -ENOMEM;
1516 
1517 	flow_keys = alloc_percpu(struct action_flow_keys);
1518 	if (!flow_keys) {
1519 		free_percpu(action_fifos);
1520 		return -ENOMEM;
1521 	}
1522 
1523 	return 0;
1524 }
1525 
1526 void action_fifos_exit(void)
1527 {
1528 	free_percpu(action_fifos);
1529 	free_percpu(flow_keys);
1530 }
1531