xref: /openbmc/linux/net/openvswitch/actions.c (revision a3a66c38)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2007-2017 Nicira, Inc.
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/skbuff.h>
9 #include <linux/in.h>
10 #include <linux/ip.h>
11 #include <linux/openvswitch.h>
12 #include <linux/netfilter_ipv6.h>
13 #include <linux/sctp.h>
14 #include <linux/tcp.h>
15 #include <linux/udp.h>
16 #include <linux/in6.h>
17 #include <linux/if_arp.h>
18 #include <linux/if_vlan.h>
19 
20 #include <net/dst.h>
21 #include <net/ip.h>
22 #include <net/ipv6.h>
23 #include <net/ip6_fib.h>
24 #include <net/checksum.h>
25 #include <net/dsfield.h>
26 #include <net/mpls.h>
27 #include <net/sctp/checksum.h>
28 
29 #include "datapath.h"
30 #include "flow.h"
31 #include "conntrack.h"
32 #include "vport.h"
33 #include "flow_netlink.h"
34 
35 struct deferred_action {
36 	struct sk_buff *skb;
37 	const struct nlattr *actions;
38 	int actions_len;
39 
40 	/* Store pkt_key clone when creating deferred action. */
41 	struct sw_flow_key pkt_key;
42 };
43 
44 #define MAX_L2_LEN	(VLAN_ETH_HLEN + 3 * MPLS_HLEN)
45 struct ovs_frag_data {
46 	unsigned long dst;
47 	struct vport *vport;
48 	struct ovs_skb_cb cb;
49 	__be16 inner_protocol;
50 	u16 network_offset;	/* valid only for MPLS */
51 	u16 vlan_tci;
52 	__be16 vlan_proto;
53 	unsigned int l2_len;
54 	u8 mac_proto;
55 	u8 l2_data[MAX_L2_LEN];
56 };
57 
58 static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage);
59 
60 #define DEFERRED_ACTION_FIFO_SIZE 10
61 #define OVS_RECURSION_LIMIT 5
62 #define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2)
63 struct action_fifo {
64 	int head;
65 	int tail;
66 	/* Deferred action fifo queue storage. */
67 	struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
68 };
69 
70 struct action_flow_keys {
71 	struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD];
72 };
73 
74 static struct action_fifo __percpu *action_fifos;
75 static struct action_flow_keys __percpu *flow_keys;
76 static DEFINE_PER_CPU(int, exec_actions_level);
77 
78 /* Make a clone of the 'key', using the pre-allocated percpu 'flow_keys'
79  * space. Return NULL if out of key spaces.
80  */
81 static struct sw_flow_key *clone_key(const struct sw_flow_key *key_)
82 {
83 	struct action_flow_keys *keys = this_cpu_ptr(flow_keys);
84 	int level = this_cpu_read(exec_actions_level);
85 	struct sw_flow_key *key = NULL;
86 
87 	if (level <= OVS_DEFERRED_ACTION_THRESHOLD) {
88 		key = &keys->key[level - 1];
89 		*key = *key_;
90 	}
91 
92 	return key;
93 }
94 
95 static void action_fifo_init(struct action_fifo *fifo)
96 {
97 	fifo->head = 0;
98 	fifo->tail = 0;
99 }
100 
101 static bool action_fifo_is_empty(const struct action_fifo *fifo)
102 {
103 	return (fifo->head == fifo->tail);
104 }
105 
106 static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
107 {
108 	if (action_fifo_is_empty(fifo))
109 		return NULL;
110 
111 	return &fifo->fifo[fifo->tail++];
112 }
113 
114 static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
115 {
116 	if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
117 		return NULL;
118 
119 	return &fifo->fifo[fifo->head++];
120 }
121 
122 /* Return true if fifo is not full */
123 static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
124 				    const struct sw_flow_key *key,
125 				    const struct nlattr *actions,
126 				    const int actions_len)
127 {
128 	struct action_fifo *fifo;
129 	struct deferred_action *da;
130 
131 	fifo = this_cpu_ptr(action_fifos);
132 	da = action_fifo_put(fifo);
133 	if (da) {
134 		da->skb = skb;
135 		da->actions = actions;
136 		da->actions_len = actions_len;
137 		da->pkt_key = *key;
138 	}
139 
140 	return da;
141 }
142 
143 static void invalidate_flow_key(struct sw_flow_key *key)
144 {
145 	key->mac_proto |= SW_FLOW_KEY_INVALID;
146 }
147 
148 static bool is_flow_key_valid(const struct sw_flow_key *key)
149 {
150 	return !(key->mac_proto & SW_FLOW_KEY_INVALID);
151 }
152 
153 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
154 			 struct sw_flow_key *key,
155 			 u32 recirc_id,
156 			 const struct nlattr *actions, int len,
157 			 bool last, bool clone_flow_key);
158 
159 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
160 			      struct sw_flow_key *key,
161 			      const struct nlattr *attr, int len);
162 
163 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
164 		     __be32 mpls_lse, __be16 mpls_ethertype, __u16 mac_len)
165 {
166 	int err;
167 
168 	err = skb_mpls_push(skb, mpls_lse, mpls_ethertype, mac_len, !!mac_len);
169 	if (err)
170 		return err;
171 
172 	if (!mac_len)
173 		key->mac_proto = MAC_PROTO_NONE;
174 
175 	invalidate_flow_key(key);
176 	return 0;
177 }
178 
179 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
180 		    const __be16 ethertype)
181 {
182 	int err;
183 
184 	err = skb_mpls_pop(skb, ethertype, skb->mac_len,
185 			   ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET);
186 	if (err)
187 		return err;
188 
189 	if (ethertype == htons(ETH_P_TEB))
190 		key->mac_proto = MAC_PROTO_ETHERNET;
191 
192 	invalidate_flow_key(key);
193 	return 0;
194 }
195 
196 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
197 		    const __be32 *mpls_lse, const __be32 *mask)
198 {
199 	struct mpls_shim_hdr *stack;
200 	__be32 lse;
201 	int err;
202 
203 	stack = mpls_hdr(skb);
204 	lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
205 	err = skb_mpls_update_lse(skb, lse);
206 	if (err)
207 		return err;
208 
209 	flow_key->mpls.lse[0] = lse;
210 	return 0;
211 }
212 
213 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
214 {
215 	int err;
216 
217 	err = skb_vlan_pop(skb);
218 	if (skb_vlan_tag_present(skb)) {
219 		invalidate_flow_key(key);
220 	} else {
221 		key->eth.vlan.tci = 0;
222 		key->eth.vlan.tpid = 0;
223 	}
224 	return err;
225 }
226 
227 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
228 		     const struct ovs_action_push_vlan *vlan)
229 {
230 	if (skb_vlan_tag_present(skb)) {
231 		invalidate_flow_key(key);
232 	} else {
233 		key->eth.vlan.tci = vlan->vlan_tci;
234 		key->eth.vlan.tpid = vlan->vlan_tpid;
235 	}
236 	return skb_vlan_push(skb, vlan->vlan_tpid,
237 			     ntohs(vlan->vlan_tci) & ~VLAN_CFI_MASK);
238 }
239 
240 /* 'src' is already properly masked. */
241 static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
242 {
243 	u16 *dst = (u16 *)dst_;
244 	const u16 *src = (const u16 *)src_;
245 	const u16 *mask = (const u16 *)mask_;
246 
247 	OVS_SET_MASKED(dst[0], src[0], mask[0]);
248 	OVS_SET_MASKED(dst[1], src[1], mask[1]);
249 	OVS_SET_MASKED(dst[2], src[2], mask[2]);
250 }
251 
252 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
253 			const struct ovs_key_ethernet *key,
254 			const struct ovs_key_ethernet *mask)
255 {
256 	int err;
257 
258 	err = skb_ensure_writable(skb, ETH_HLEN);
259 	if (unlikely(err))
260 		return err;
261 
262 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
263 
264 	ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
265 			       mask->eth_src);
266 	ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
267 			       mask->eth_dst);
268 
269 	skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
270 
271 	ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
272 	ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
273 	return 0;
274 }
275 
276 /* pop_eth does not support VLAN packets as this action is never called
277  * for them.
278  */
279 static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key)
280 {
281 	skb_pull_rcsum(skb, ETH_HLEN);
282 	skb_reset_mac_header(skb);
283 	skb_reset_mac_len(skb);
284 
285 	/* safe right before invalidate_flow_key */
286 	key->mac_proto = MAC_PROTO_NONE;
287 	invalidate_flow_key(key);
288 	return 0;
289 }
290 
291 static int push_eth(struct sk_buff *skb, struct sw_flow_key *key,
292 		    const struct ovs_action_push_eth *ethh)
293 {
294 	struct ethhdr *hdr;
295 
296 	/* Add the new Ethernet header */
297 	if (skb_cow_head(skb, ETH_HLEN) < 0)
298 		return -ENOMEM;
299 
300 	skb_push(skb, ETH_HLEN);
301 	skb_reset_mac_header(skb);
302 	skb_reset_mac_len(skb);
303 
304 	hdr = eth_hdr(skb);
305 	ether_addr_copy(hdr->h_source, ethh->addresses.eth_src);
306 	ether_addr_copy(hdr->h_dest, ethh->addresses.eth_dst);
307 	hdr->h_proto = skb->protocol;
308 
309 	skb_postpush_rcsum(skb, hdr, ETH_HLEN);
310 
311 	/* safe right before invalidate_flow_key */
312 	key->mac_proto = MAC_PROTO_ETHERNET;
313 	invalidate_flow_key(key);
314 	return 0;
315 }
316 
317 static int push_nsh(struct sk_buff *skb, struct sw_flow_key *key,
318 		    const struct nshhdr *nh)
319 {
320 	int err;
321 
322 	err = nsh_push(skb, nh);
323 	if (err)
324 		return err;
325 
326 	/* safe right before invalidate_flow_key */
327 	key->mac_proto = MAC_PROTO_NONE;
328 	invalidate_flow_key(key);
329 	return 0;
330 }
331 
332 static int pop_nsh(struct sk_buff *skb, struct sw_flow_key *key)
333 {
334 	int err;
335 
336 	err = nsh_pop(skb);
337 	if (err)
338 		return err;
339 
340 	/* safe right before invalidate_flow_key */
341 	if (skb->protocol == htons(ETH_P_TEB))
342 		key->mac_proto = MAC_PROTO_ETHERNET;
343 	else
344 		key->mac_proto = MAC_PROTO_NONE;
345 	invalidate_flow_key(key);
346 	return 0;
347 }
348 
349 static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
350 				  __be32 addr, __be32 new_addr)
351 {
352 	int transport_len = skb->len - skb_transport_offset(skb);
353 
354 	if (nh->frag_off & htons(IP_OFFSET))
355 		return;
356 
357 	if (nh->protocol == IPPROTO_TCP) {
358 		if (likely(transport_len >= sizeof(struct tcphdr)))
359 			inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
360 						 addr, new_addr, true);
361 	} else if (nh->protocol == IPPROTO_UDP) {
362 		if (likely(transport_len >= sizeof(struct udphdr))) {
363 			struct udphdr *uh = udp_hdr(skb);
364 
365 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
366 				inet_proto_csum_replace4(&uh->check, skb,
367 							 addr, new_addr, true);
368 				if (!uh->check)
369 					uh->check = CSUM_MANGLED_0;
370 			}
371 		}
372 	}
373 }
374 
375 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
376 			__be32 *addr, __be32 new_addr)
377 {
378 	update_ip_l4_checksum(skb, nh, *addr, new_addr);
379 	csum_replace4(&nh->check, *addr, new_addr);
380 	skb_clear_hash(skb);
381 	*addr = new_addr;
382 }
383 
384 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
385 				 __be32 addr[4], const __be32 new_addr[4])
386 {
387 	int transport_len = skb->len - skb_transport_offset(skb);
388 
389 	if (l4_proto == NEXTHDR_TCP) {
390 		if (likely(transport_len >= sizeof(struct tcphdr)))
391 			inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
392 						  addr, new_addr, true);
393 	} else if (l4_proto == NEXTHDR_UDP) {
394 		if (likely(transport_len >= sizeof(struct udphdr))) {
395 			struct udphdr *uh = udp_hdr(skb);
396 
397 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
398 				inet_proto_csum_replace16(&uh->check, skb,
399 							  addr, new_addr, true);
400 				if (!uh->check)
401 					uh->check = CSUM_MANGLED_0;
402 			}
403 		}
404 	} else if (l4_proto == NEXTHDR_ICMP) {
405 		if (likely(transport_len >= sizeof(struct icmp6hdr)))
406 			inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
407 						  skb, addr, new_addr, true);
408 	}
409 }
410 
411 static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
412 			   const __be32 mask[4], __be32 masked[4])
413 {
414 	masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
415 	masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
416 	masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
417 	masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
418 }
419 
420 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
421 			  __be32 addr[4], const __be32 new_addr[4],
422 			  bool recalculate_csum)
423 {
424 	if (recalculate_csum)
425 		update_ipv6_checksum(skb, l4_proto, addr, new_addr);
426 
427 	skb_clear_hash(skb);
428 	memcpy(addr, new_addr, sizeof(__be32[4]));
429 }
430 
431 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
432 {
433 	/* Bits 21-24 are always unmasked, so this retains their values. */
434 	OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
435 	OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
436 	OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
437 }
438 
439 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
440 		       u8 mask)
441 {
442 	new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);
443 
444 	csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
445 	nh->ttl = new_ttl;
446 }
447 
448 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
449 		    const struct ovs_key_ipv4 *key,
450 		    const struct ovs_key_ipv4 *mask)
451 {
452 	struct iphdr *nh;
453 	__be32 new_addr;
454 	int err;
455 
456 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
457 				  sizeof(struct iphdr));
458 	if (unlikely(err))
459 		return err;
460 
461 	nh = ip_hdr(skb);
462 
463 	/* Setting an IP addresses is typically only a side effect of
464 	 * matching on them in the current userspace implementation, so it
465 	 * makes sense to check if the value actually changed.
466 	 */
467 	if (mask->ipv4_src) {
468 		new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
469 
470 		if (unlikely(new_addr != nh->saddr)) {
471 			set_ip_addr(skb, nh, &nh->saddr, new_addr);
472 			flow_key->ipv4.addr.src = new_addr;
473 		}
474 	}
475 	if (mask->ipv4_dst) {
476 		new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
477 
478 		if (unlikely(new_addr != nh->daddr)) {
479 			set_ip_addr(skb, nh, &nh->daddr, new_addr);
480 			flow_key->ipv4.addr.dst = new_addr;
481 		}
482 	}
483 	if (mask->ipv4_tos) {
484 		ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
485 		flow_key->ip.tos = nh->tos;
486 	}
487 	if (mask->ipv4_ttl) {
488 		set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
489 		flow_key->ip.ttl = nh->ttl;
490 	}
491 
492 	return 0;
493 }
494 
495 static bool is_ipv6_mask_nonzero(const __be32 addr[4])
496 {
497 	return !!(addr[0] | addr[1] | addr[2] | addr[3]);
498 }
499 
500 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
501 		    const struct ovs_key_ipv6 *key,
502 		    const struct ovs_key_ipv6 *mask)
503 {
504 	struct ipv6hdr *nh;
505 	int err;
506 
507 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
508 				  sizeof(struct ipv6hdr));
509 	if (unlikely(err))
510 		return err;
511 
512 	nh = ipv6_hdr(skb);
513 
514 	/* Setting an IP addresses is typically only a side effect of
515 	 * matching on them in the current userspace implementation, so it
516 	 * makes sense to check if the value actually changed.
517 	 */
518 	if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
519 		__be32 *saddr = (__be32 *)&nh->saddr;
520 		__be32 masked[4];
521 
522 		mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
523 
524 		if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
525 			set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
526 				      true);
527 			memcpy(&flow_key->ipv6.addr.src, masked,
528 			       sizeof(flow_key->ipv6.addr.src));
529 		}
530 	}
531 	if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
532 		unsigned int offset = 0;
533 		int flags = IP6_FH_F_SKIP_RH;
534 		bool recalc_csum = true;
535 		__be32 *daddr = (__be32 *)&nh->daddr;
536 		__be32 masked[4];
537 
538 		mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
539 
540 		if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
541 			if (ipv6_ext_hdr(nh->nexthdr))
542 				recalc_csum = (ipv6_find_hdr(skb, &offset,
543 							     NEXTHDR_ROUTING,
544 							     NULL, &flags)
545 					       != NEXTHDR_ROUTING);
546 
547 			set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
548 				      recalc_csum);
549 			memcpy(&flow_key->ipv6.addr.dst, masked,
550 			       sizeof(flow_key->ipv6.addr.dst));
551 		}
552 	}
553 	if (mask->ipv6_tclass) {
554 		ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
555 		flow_key->ip.tos = ipv6_get_dsfield(nh);
556 	}
557 	if (mask->ipv6_label) {
558 		set_ipv6_fl(nh, ntohl(key->ipv6_label),
559 			    ntohl(mask->ipv6_label));
560 		flow_key->ipv6.label =
561 		    *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
562 	}
563 	if (mask->ipv6_hlimit) {
564 		OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit,
565 			       mask->ipv6_hlimit);
566 		flow_key->ip.ttl = nh->hop_limit;
567 	}
568 	return 0;
569 }
570 
571 static int set_nsh(struct sk_buff *skb, struct sw_flow_key *flow_key,
572 		   const struct nlattr *a)
573 {
574 	struct nshhdr *nh;
575 	size_t length;
576 	int err;
577 	u8 flags;
578 	u8 ttl;
579 	int i;
580 
581 	struct ovs_key_nsh key;
582 	struct ovs_key_nsh mask;
583 
584 	err = nsh_key_from_nlattr(a, &key, &mask);
585 	if (err)
586 		return err;
587 
588 	/* Make sure the NSH base header is there */
589 	if (!pskb_may_pull(skb, skb_network_offset(skb) + NSH_BASE_HDR_LEN))
590 		return -ENOMEM;
591 
592 	nh = nsh_hdr(skb);
593 	length = nsh_hdr_len(nh);
594 
595 	/* Make sure the whole NSH header is there */
596 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
597 				       length);
598 	if (unlikely(err))
599 		return err;
600 
601 	nh = nsh_hdr(skb);
602 	skb_postpull_rcsum(skb, nh, length);
603 	flags = nsh_get_flags(nh);
604 	flags = OVS_MASKED(flags, key.base.flags, mask.base.flags);
605 	flow_key->nsh.base.flags = flags;
606 	ttl = nsh_get_ttl(nh);
607 	ttl = OVS_MASKED(ttl, key.base.ttl, mask.base.ttl);
608 	flow_key->nsh.base.ttl = ttl;
609 	nsh_set_flags_and_ttl(nh, flags, ttl);
610 	nh->path_hdr = OVS_MASKED(nh->path_hdr, key.base.path_hdr,
611 				  mask.base.path_hdr);
612 	flow_key->nsh.base.path_hdr = nh->path_hdr;
613 	switch (nh->mdtype) {
614 	case NSH_M_TYPE1:
615 		for (i = 0; i < NSH_MD1_CONTEXT_SIZE; i++) {
616 			nh->md1.context[i] =
617 			    OVS_MASKED(nh->md1.context[i], key.context[i],
618 				       mask.context[i]);
619 		}
620 		memcpy(flow_key->nsh.context, nh->md1.context,
621 		       sizeof(nh->md1.context));
622 		break;
623 	case NSH_M_TYPE2:
624 		memset(flow_key->nsh.context, 0,
625 		       sizeof(flow_key->nsh.context));
626 		break;
627 	default:
628 		return -EINVAL;
629 	}
630 	skb_postpush_rcsum(skb, nh, length);
631 	return 0;
632 }
633 
634 /* Must follow skb_ensure_writable() since that can move the skb data. */
635 static void set_tp_port(struct sk_buff *skb, __be16 *port,
636 			__be16 new_port, __sum16 *check)
637 {
638 	inet_proto_csum_replace2(check, skb, *port, new_port, false);
639 	*port = new_port;
640 }
641 
642 static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
643 		   const struct ovs_key_udp *key,
644 		   const struct ovs_key_udp *mask)
645 {
646 	struct udphdr *uh;
647 	__be16 src, dst;
648 	int err;
649 
650 	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
651 				  sizeof(struct udphdr));
652 	if (unlikely(err))
653 		return err;
654 
655 	uh = udp_hdr(skb);
656 	/* Either of the masks is non-zero, so do not bother checking them. */
657 	src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src);
658 	dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst);
659 
660 	if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
661 		if (likely(src != uh->source)) {
662 			set_tp_port(skb, &uh->source, src, &uh->check);
663 			flow_key->tp.src = src;
664 		}
665 		if (likely(dst != uh->dest)) {
666 			set_tp_port(skb, &uh->dest, dst, &uh->check);
667 			flow_key->tp.dst = dst;
668 		}
669 
670 		if (unlikely(!uh->check))
671 			uh->check = CSUM_MANGLED_0;
672 	} else {
673 		uh->source = src;
674 		uh->dest = dst;
675 		flow_key->tp.src = src;
676 		flow_key->tp.dst = dst;
677 	}
678 
679 	skb_clear_hash(skb);
680 
681 	return 0;
682 }
683 
684 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
685 		   const struct ovs_key_tcp *key,
686 		   const struct ovs_key_tcp *mask)
687 {
688 	struct tcphdr *th;
689 	__be16 src, dst;
690 	int err;
691 
692 	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
693 				  sizeof(struct tcphdr));
694 	if (unlikely(err))
695 		return err;
696 
697 	th = tcp_hdr(skb);
698 	src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src);
699 	if (likely(src != th->source)) {
700 		set_tp_port(skb, &th->source, src, &th->check);
701 		flow_key->tp.src = src;
702 	}
703 	dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
704 	if (likely(dst != th->dest)) {
705 		set_tp_port(skb, &th->dest, dst, &th->check);
706 		flow_key->tp.dst = dst;
707 	}
708 	skb_clear_hash(skb);
709 
710 	return 0;
711 }
712 
713 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
714 		    const struct ovs_key_sctp *key,
715 		    const struct ovs_key_sctp *mask)
716 {
717 	unsigned int sctphoff = skb_transport_offset(skb);
718 	struct sctphdr *sh;
719 	__le32 old_correct_csum, new_csum, old_csum;
720 	int err;
721 
722 	err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
723 	if (unlikely(err))
724 		return err;
725 
726 	sh = sctp_hdr(skb);
727 	old_csum = sh->checksum;
728 	old_correct_csum = sctp_compute_cksum(skb, sctphoff);
729 
730 	sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src);
731 	sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
732 
733 	new_csum = sctp_compute_cksum(skb, sctphoff);
734 
735 	/* Carry any checksum errors through. */
736 	sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
737 
738 	skb_clear_hash(skb);
739 	flow_key->tp.src = sh->source;
740 	flow_key->tp.dst = sh->dest;
741 
742 	return 0;
743 }
744 
745 static int ovs_vport_output(struct net *net, struct sock *sk, struct sk_buff *skb)
746 {
747 	struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
748 	struct vport *vport = data->vport;
749 
750 	if (skb_cow_head(skb, data->l2_len) < 0) {
751 		kfree_skb(skb);
752 		return -ENOMEM;
753 	}
754 
755 	__skb_dst_copy(skb, data->dst);
756 	*OVS_CB(skb) = data->cb;
757 	skb->inner_protocol = data->inner_protocol;
758 	if (data->vlan_tci & VLAN_CFI_MASK)
759 		__vlan_hwaccel_put_tag(skb, data->vlan_proto, data->vlan_tci & ~VLAN_CFI_MASK);
760 	else
761 		__vlan_hwaccel_clear_tag(skb);
762 
763 	/* Reconstruct the MAC header.  */
764 	skb_push(skb, data->l2_len);
765 	memcpy(skb->data, &data->l2_data, data->l2_len);
766 	skb_postpush_rcsum(skb, skb->data, data->l2_len);
767 	skb_reset_mac_header(skb);
768 
769 	if (eth_p_mpls(skb->protocol)) {
770 		skb->inner_network_header = skb->network_header;
771 		skb_set_network_header(skb, data->network_offset);
772 		skb_reset_mac_len(skb);
773 	}
774 
775 	ovs_vport_send(vport, skb, data->mac_proto);
776 	return 0;
777 }
778 
779 static unsigned int
780 ovs_dst_get_mtu(const struct dst_entry *dst)
781 {
782 	return dst->dev->mtu;
783 }
784 
785 static struct dst_ops ovs_dst_ops = {
786 	.family = AF_UNSPEC,
787 	.mtu = ovs_dst_get_mtu,
788 };
789 
790 /* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
791  * ovs_vport_output(), which is called once per fragmented packet.
792  */
793 static void prepare_frag(struct vport *vport, struct sk_buff *skb,
794 			 u16 orig_network_offset, u8 mac_proto)
795 {
796 	unsigned int hlen = skb_network_offset(skb);
797 	struct ovs_frag_data *data;
798 
799 	data = this_cpu_ptr(&ovs_frag_data_storage);
800 	data->dst = skb->_skb_refdst;
801 	data->vport = vport;
802 	data->cb = *OVS_CB(skb);
803 	data->inner_protocol = skb->inner_protocol;
804 	data->network_offset = orig_network_offset;
805 	if (skb_vlan_tag_present(skb))
806 		data->vlan_tci = skb_vlan_tag_get(skb) | VLAN_CFI_MASK;
807 	else
808 		data->vlan_tci = 0;
809 	data->vlan_proto = skb->vlan_proto;
810 	data->mac_proto = mac_proto;
811 	data->l2_len = hlen;
812 	memcpy(&data->l2_data, skb->data, hlen);
813 
814 	memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
815 	skb_pull(skb, hlen);
816 }
817 
818 static void ovs_fragment(struct net *net, struct vport *vport,
819 			 struct sk_buff *skb, u16 mru,
820 			 struct sw_flow_key *key)
821 {
822 	u16 orig_network_offset = 0;
823 
824 	if (eth_p_mpls(skb->protocol)) {
825 		orig_network_offset = skb_network_offset(skb);
826 		skb->network_header = skb->inner_network_header;
827 	}
828 
829 	if (skb_network_offset(skb) > MAX_L2_LEN) {
830 		OVS_NLERR(1, "L2 header too long to fragment");
831 		goto err;
832 	}
833 
834 	if (key->eth.type == htons(ETH_P_IP)) {
835 		struct dst_entry ovs_dst;
836 		unsigned long orig_dst;
837 
838 		prepare_frag(vport, skb, orig_network_offset,
839 			     ovs_key_mac_proto(key));
840 		dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
841 			 DST_OBSOLETE_NONE, DST_NOCOUNT);
842 		ovs_dst.dev = vport->dev;
843 
844 		orig_dst = skb->_skb_refdst;
845 		skb_dst_set_noref(skb, &ovs_dst);
846 		IPCB(skb)->frag_max_size = mru;
847 
848 		ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
849 		refdst_drop(orig_dst);
850 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
851 		const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
852 		unsigned long orig_dst;
853 		struct rt6_info ovs_rt;
854 
855 		if (!v6ops)
856 			goto err;
857 
858 		prepare_frag(vport, skb, orig_network_offset,
859 			     ovs_key_mac_proto(key));
860 		memset(&ovs_rt, 0, sizeof(ovs_rt));
861 		dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
862 			 DST_OBSOLETE_NONE, DST_NOCOUNT);
863 		ovs_rt.dst.dev = vport->dev;
864 
865 		orig_dst = skb->_skb_refdst;
866 		skb_dst_set_noref(skb, &ovs_rt.dst);
867 		IP6CB(skb)->frag_max_size = mru;
868 
869 		v6ops->fragment(net, skb->sk, skb, ovs_vport_output);
870 		refdst_drop(orig_dst);
871 	} else {
872 		WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
873 			  ovs_vport_name(vport), ntohs(key->eth.type), mru,
874 			  vport->dev->mtu);
875 		goto err;
876 	}
877 
878 	return;
879 err:
880 	kfree_skb(skb);
881 }
882 
883 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
884 		      struct sw_flow_key *key)
885 {
886 	struct vport *vport = ovs_vport_rcu(dp, out_port);
887 
888 	if (likely(vport)) {
889 		u16 mru = OVS_CB(skb)->mru;
890 		u32 cutlen = OVS_CB(skb)->cutlen;
891 
892 		if (unlikely(cutlen > 0)) {
893 			if (skb->len - cutlen > ovs_mac_header_len(key))
894 				pskb_trim(skb, skb->len - cutlen);
895 			else
896 				pskb_trim(skb, ovs_mac_header_len(key));
897 		}
898 
899 		if (likely(!mru ||
900 		           (skb->len <= mru + vport->dev->hard_header_len))) {
901 			ovs_vport_send(vport, skb, ovs_key_mac_proto(key));
902 		} else if (mru <= vport->dev->mtu) {
903 			struct net *net = read_pnet(&dp->net);
904 
905 			ovs_fragment(net, vport, skb, mru, key);
906 		} else {
907 			kfree_skb(skb);
908 		}
909 	} else {
910 		kfree_skb(skb);
911 	}
912 }
913 
914 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
915 			    struct sw_flow_key *key, const struct nlattr *attr,
916 			    const struct nlattr *actions, int actions_len,
917 			    uint32_t cutlen)
918 {
919 	struct dp_upcall_info upcall;
920 	const struct nlattr *a;
921 	int rem;
922 
923 	memset(&upcall, 0, sizeof(upcall));
924 	upcall.cmd = OVS_PACKET_CMD_ACTION;
925 	upcall.mru = OVS_CB(skb)->mru;
926 
927 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
928 		 a = nla_next(a, &rem)) {
929 		switch (nla_type(a)) {
930 		case OVS_USERSPACE_ATTR_USERDATA:
931 			upcall.userdata = a;
932 			break;
933 
934 		case OVS_USERSPACE_ATTR_PID:
935 			upcall.portid = nla_get_u32(a);
936 			break;
937 
938 		case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
939 			/* Get out tunnel info. */
940 			struct vport *vport;
941 
942 			vport = ovs_vport_rcu(dp, nla_get_u32(a));
943 			if (vport) {
944 				int err;
945 
946 				err = dev_fill_metadata_dst(vport->dev, skb);
947 				if (!err)
948 					upcall.egress_tun_info = skb_tunnel_info(skb);
949 			}
950 
951 			break;
952 		}
953 
954 		case OVS_USERSPACE_ATTR_ACTIONS: {
955 			/* Include actions. */
956 			upcall.actions = actions;
957 			upcall.actions_len = actions_len;
958 			break;
959 		}
960 
961 		} /* End of switch. */
962 	}
963 
964 	return ovs_dp_upcall(dp, skb, key, &upcall, cutlen);
965 }
966 
967 static int dec_ttl_exception_handler(struct datapath *dp, struct sk_buff *skb,
968 				     struct sw_flow_key *key,
969 				     const struct nlattr *attr, bool last)
970 {
971 	/* The first action is always 'OVS_DEC_TTL_ATTR_ARG'. */
972 	struct nlattr *dec_ttl_arg = nla_data(attr);
973 	int rem = nla_len(attr);
974 
975 	if (nla_len(dec_ttl_arg)) {
976 		struct nlattr *actions = nla_next(dec_ttl_arg, &rem);
977 
978 		if (actions)
979 			return clone_execute(dp, skb, key, 0, actions, rem,
980 					     last, false);
981 	}
982 	consume_skb(skb);
983 	return 0;
984 }
985 
986 /* When 'last' is true, sample() should always consume the 'skb'.
987  * Otherwise, sample() should keep 'skb' intact regardless what
988  * actions are executed within sample().
989  */
990 static int sample(struct datapath *dp, struct sk_buff *skb,
991 		  struct sw_flow_key *key, const struct nlattr *attr,
992 		  bool last)
993 {
994 	struct nlattr *actions;
995 	struct nlattr *sample_arg;
996 	int rem = nla_len(attr);
997 	const struct sample_arg *arg;
998 	bool clone_flow_key;
999 
1000 	/* The first action is always 'OVS_SAMPLE_ATTR_ARG'. */
1001 	sample_arg = nla_data(attr);
1002 	arg = nla_data(sample_arg);
1003 	actions = nla_next(sample_arg, &rem);
1004 
1005 	if ((arg->probability != U32_MAX) &&
1006 	    (!arg->probability || prandom_u32() > arg->probability)) {
1007 		if (last)
1008 			consume_skb(skb);
1009 		return 0;
1010 	}
1011 
1012 	clone_flow_key = !arg->exec;
1013 	return clone_execute(dp, skb, key, 0, actions, rem, last,
1014 			     clone_flow_key);
1015 }
1016 
1017 /* When 'last' is true, clone() should always consume the 'skb'.
1018  * Otherwise, clone() should keep 'skb' intact regardless what
1019  * actions are executed within clone().
1020  */
1021 static int clone(struct datapath *dp, struct sk_buff *skb,
1022 		 struct sw_flow_key *key, const struct nlattr *attr,
1023 		 bool last)
1024 {
1025 	struct nlattr *actions;
1026 	struct nlattr *clone_arg;
1027 	int rem = nla_len(attr);
1028 	bool dont_clone_flow_key;
1029 
1030 	/* The first action is always 'OVS_CLONE_ATTR_ARG'. */
1031 	clone_arg = nla_data(attr);
1032 	dont_clone_flow_key = nla_get_u32(clone_arg);
1033 	actions = nla_next(clone_arg, &rem);
1034 
1035 	return clone_execute(dp, skb, key, 0, actions, rem, last,
1036 			     !dont_clone_flow_key);
1037 }
1038 
1039 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
1040 			 const struct nlattr *attr)
1041 {
1042 	struct ovs_action_hash *hash_act = nla_data(attr);
1043 	u32 hash = 0;
1044 
1045 	/* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
1046 	hash = skb_get_hash(skb);
1047 	hash = jhash_1word(hash, hash_act->hash_basis);
1048 	if (!hash)
1049 		hash = 0x1;
1050 
1051 	key->ovs_flow_hash = hash;
1052 }
1053 
1054 static int execute_set_action(struct sk_buff *skb,
1055 			      struct sw_flow_key *flow_key,
1056 			      const struct nlattr *a)
1057 {
1058 	/* Only tunnel set execution is supported without a mask. */
1059 	if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
1060 		struct ovs_tunnel_info *tun = nla_data(a);
1061 
1062 		skb_dst_drop(skb);
1063 		dst_hold((struct dst_entry *)tun->tun_dst);
1064 		skb_dst_set(skb, (struct dst_entry *)tun->tun_dst);
1065 		return 0;
1066 	}
1067 
1068 	return -EINVAL;
1069 }
1070 
1071 /* Mask is at the midpoint of the data. */
1072 #define get_mask(a, type) ((const type)nla_data(a) + 1)
1073 
1074 static int execute_masked_set_action(struct sk_buff *skb,
1075 				     struct sw_flow_key *flow_key,
1076 				     const struct nlattr *a)
1077 {
1078 	int err = 0;
1079 
1080 	switch (nla_type(a)) {
1081 	case OVS_KEY_ATTR_PRIORITY:
1082 		OVS_SET_MASKED(skb->priority, nla_get_u32(a),
1083 			       *get_mask(a, u32 *));
1084 		flow_key->phy.priority = skb->priority;
1085 		break;
1086 
1087 	case OVS_KEY_ATTR_SKB_MARK:
1088 		OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
1089 		flow_key->phy.skb_mark = skb->mark;
1090 		break;
1091 
1092 	case OVS_KEY_ATTR_TUNNEL_INFO:
1093 		/* Masked data not supported for tunnel. */
1094 		err = -EINVAL;
1095 		break;
1096 
1097 	case OVS_KEY_ATTR_ETHERNET:
1098 		err = set_eth_addr(skb, flow_key, nla_data(a),
1099 				   get_mask(a, struct ovs_key_ethernet *));
1100 		break;
1101 
1102 	case OVS_KEY_ATTR_NSH:
1103 		err = set_nsh(skb, flow_key, a);
1104 		break;
1105 
1106 	case OVS_KEY_ATTR_IPV4:
1107 		err = set_ipv4(skb, flow_key, nla_data(a),
1108 			       get_mask(a, struct ovs_key_ipv4 *));
1109 		break;
1110 
1111 	case OVS_KEY_ATTR_IPV6:
1112 		err = set_ipv6(skb, flow_key, nla_data(a),
1113 			       get_mask(a, struct ovs_key_ipv6 *));
1114 		break;
1115 
1116 	case OVS_KEY_ATTR_TCP:
1117 		err = set_tcp(skb, flow_key, nla_data(a),
1118 			      get_mask(a, struct ovs_key_tcp *));
1119 		break;
1120 
1121 	case OVS_KEY_ATTR_UDP:
1122 		err = set_udp(skb, flow_key, nla_data(a),
1123 			      get_mask(a, struct ovs_key_udp *));
1124 		break;
1125 
1126 	case OVS_KEY_ATTR_SCTP:
1127 		err = set_sctp(skb, flow_key, nla_data(a),
1128 			       get_mask(a, struct ovs_key_sctp *));
1129 		break;
1130 
1131 	case OVS_KEY_ATTR_MPLS:
1132 		err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
1133 								    __be32 *));
1134 		break;
1135 
1136 	case OVS_KEY_ATTR_CT_STATE:
1137 	case OVS_KEY_ATTR_CT_ZONE:
1138 	case OVS_KEY_ATTR_CT_MARK:
1139 	case OVS_KEY_ATTR_CT_LABELS:
1140 	case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4:
1141 	case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6:
1142 		err = -EINVAL;
1143 		break;
1144 	}
1145 
1146 	return err;
1147 }
1148 
1149 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
1150 			  struct sw_flow_key *key,
1151 			  const struct nlattr *a, bool last)
1152 {
1153 	u32 recirc_id;
1154 
1155 	if (!is_flow_key_valid(key)) {
1156 		int err;
1157 
1158 		err = ovs_flow_key_update(skb, key);
1159 		if (err)
1160 			return err;
1161 	}
1162 	BUG_ON(!is_flow_key_valid(key));
1163 
1164 	recirc_id = nla_get_u32(a);
1165 	return clone_execute(dp, skb, key, recirc_id, NULL, 0, last, true);
1166 }
1167 
1168 static int execute_check_pkt_len(struct datapath *dp, struct sk_buff *skb,
1169 				 struct sw_flow_key *key,
1170 				 const struct nlattr *attr, bool last)
1171 {
1172 	struct ovs_skb_cb *ovs_cb = OVS_CB(skb);
1173 	const struct nlattr *actions, *cpl_arg;
1174 	int len, max_len, rem = nla_len(attr);
1175 	const struct check_pkt_len_arg *arg;
1176 	bool clone_flow_key;
1177 
1178 	/* The first netlink attribute in 'attr' is always
1179 	 * 'OVS_CHECK_PKT_LEN_ATTR_ARG'.
1180 	 */
1181 	cpl_arg = nla_data(attr);
1182 	arg = nla_data(cpl_arg);
1183 
1184 	len = ovs_cb->mru ? ovs_cb->mru + skb->mac_len : skb->len;
1185 	max_len = arg->pkt_len;
1186 
1187 	if ((skb_is_gso(skb) && skb_gso_validate_mac_len(skb, max_len)) ||
1188 	    len <= max_len) {
1189 		/* Second netlink attribute in 'attr' is always
1190 		 * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'.
1191 		 */
1192 		actions = nla_next(cpl_arg, &rem);
1193 		clone_flow_key = !arg->exec_for_lesser_equal;
1194 	} else {
1195 		/* Third netlink attribute in 'attr' is always
1196 		 * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER'.
1197 		 */
1198 		actions = nla_next(cpl_arg, &rem);
1199 		actions = nla_next(actions, &rem);
1200 		clone_flow_key = !arg->exec_for_greater;
1201 	}
1202 
1203 	return clone_execute(dp, skb, key, 0, nla_data(actions),
1204 			     nla_len(actions), last, clone_flow_key);
1205 }
1206 
1207 static int execute_dec_ttl(struct sk_buff *skb, struct sw_flow_key *key)
1208 {
1209 	int err;
1210 
1211 	if (skb->protocol == htons(ETH_P_IPV6)) {
1212 		struct ipv6hdr *nh;
1213 
1214 		err = skb_ensure_writable(skb, skb_network_offset(skb) +
1215 					  sizeof(*nh));
1216 		if (unlikely(err))
1217 			return err;
1218 
1219 		nh = ipv6_hdr(skb);
1220 
1221 		if (nh->hop_limit <= 1)
1222 			return -EHOSTUNREACH;
1223 
1224 		key->ip.ttl = --nh->hop_limit;
1225 	} else {
1226 		struct iphdr *nh;
1227 		u8 old_ttl;
1228 
1229 		err = skb_ensure_writable(skb, skb_network_offset(skb) +
1230 					  sizeof(*nh));
1231 		if (unlikely(err))
1232 			return err;
1233 
1234 		nh = ip_hdr(skb);
1235 		if (nh->ttl <= 1)
1236 			return -EHOSTUNREACH;
1237 
1238 		old_ttl = nh->ttl--;
1239 		csum_replace2(&nh->check, htons(old_ttl << 8),
1240 			      htons(nh->ttl << 8));
1241 		key->ip.ttl = nh->ttl;
1242 	}
1243 	return 0;
1244 }
1245 
1246 /* Execute a list of actions against 'skb'. */
1247 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
1248 			      struct sw_flow_key *key,
1249 			      const struct nlattr *attr, int len)
1250 {
1251 	const struct nlattr *a;
1252 	int rem;
1253 
1254 	for (a = attr, rem = len; rem > 0;
1255 	     a = nla_next(a, &rem)) {
1256 		int err = 0;
1257 
1258 		switch (nla_type(a)) {
1259 		case OVS_ACTION_ATTR_OUTPUT: {
1260 			int port = nla_get_u32(a);
1261 			struct sk_buff *clone;
1262 
1263 			/* Every output action needs a separate clone
1264 			 * of 'skb', In case the output action is the
1265 			 * last action, cloning can be avoided.
1266 			 */
1267 			if (nla_is_last(a, rem)) {
1268 				do_output(dp, skb, port, key);
1269 				/* 'skb' has been used for output.
1270 				 */
1271 				return 0;
1272 			}
1273 
1274 			clone = skb_clone(skb, GFP_ATOMIC);
1275 			if (clone)
1276 				do_output(dp, clone, port, key);
1277 			OVS_CB(skb)->cutlen = 0;
1278 			break;
1279 		}
1280 
1281 		case OVS_ACTION_ATTR_TRUNC: {
1282 			struct ovs_action_trunc *trunc = nla_data(a);
1283 
1284 			if (skb->len > trunc->max_len)
1285 				OVS_CB(skb)->cutlen = skb->len - trunc->max_len;
1286 			break;
1287 		}
1288 
1289 		case OVS_ACTION_ATTR_USERSPACE:
1290 			output_userspace(dp, skb, key, a, attr,
1291 						     len, OVS_CB(skb)->cutlen);
1292 			OVS_CB(skb)->cutlen = 0;
1293 			break;
1294 
1295 		case OVS_ACTION_ATTR_HASH:
1296 			execute_hash(skb, key, a);
1297 			break;
1298 
1299 		case OVS_ACTION_ATTR_PUSH_MPLS: {
1300 			struct ovs_action_push_mpls *mpls = nla_data(a);
1301 
1302 			err = push_mpls(skb, key, mpls->mpls_lse,
1303 					mpls->mpls_ethertype, skb->mac_len);
1304 			break;
1305 		}
1306 		case OVS_ACTION_ATTR_ADD_MPLS: {
1307 			struct ovs_action_add_mpls *mpls = nla_data(a);
1308 			__u16 mac_len = 0;
1309 
1310 			if (mpls->tun_flags & OVS_MPLS_L3_TUNNEL_FLAG_MASK)
1311 				mac_len = skb->mac_len;
1312 
1313 			err = push_mpls(skb, key, mpls->mpls_lse,
1314 					mpls->mpls_ethertype, mac_len);
1315 			break;
1316 		}
1317 		case OVS_ACTION_ATTR_POP_MPLS:
1318 			err = pop_mpls(skb, key, nla_get_be16(a));
1319 			break;
1320 
1321 		case OVS_ACTION_ATTR_PUSH_VLAN:
1322 			err = push_vlan(skb, key, nla_data(a));
1323 			break;
1324 
1325 		case OVS_ACTION_ATTR_POP_VLAN:
1326 			err = pop_vlan(skb, key);
1327 			break;
1328 
1329 		case OVS_ACTION_ATTR_RECIRC: {
1330 			bool last = nla_is_last(a, rem);
1331 
1332 			err = execute_recirc(dp, skb, key, a, last);
1333 			if (last) {
1334 				/* If this is the last action, the skb has
1335 				 * been consumed or freed.
1336 				 * Return immediately.
1337 				 */
1338 				return err;
1339 			}
1340 			break;
1341 		}
1342 
1343 		case OVS_ACTION_ATTR_SET:
1344 			err = execute_set_action(skb, key, nla_data(a));
1345 			break;
1346 
1347 		case OVS_ACTION_ATTR_SET_MASKED:
1348 		case OVS_ACTION_ATTR_SET_TO_MASKED:
1349 			err = execute_masked_set_action(skb, key, nla_data(a));
1350 			break;
1351 
1352 		case OVS_ACTION_ATTR_SAMPLE: {
1353 			bool last = nla_is_last(a, rem);
1354 
1355 			err = sample(dp, skb, key, a, last);
1356 			if (last)
1357 				return err;
1358 
1359 			break;
1360 		}
1361 
1362 		case OVS_ACTION_ATTR_CT:
1363 			if (!is_flow_key_valid(key)) {
1364 				err = ovs_flow_key_update(skb, key);
1365 				if (err)
1366 					return err;
1367 			}
1368 
1369 			err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
1370 					     nla_data(a));
1371 
1372 			/* Hide stolen IP fragments from user space. */
1373 			if (err)
1374 				return err == -EINPROGRESS ? 0 : err;
1375 			break;
1376 
1377 		case OVS_ACTION_ATTR_CT_CLEAR:
1378 			err = ovs_ct_clear(skb, key);
1379 			break;
1380 
1381 		case OVS_ACTION_ATTR_PUSH_ETH:
1382 			err = push_eth(skb, key, nla_data(a));
1383 			break;
1384 
1385 		case OVS_ACTION_ATTR_POP_ETH:
1386 			err = pop_eth(skb, key);
1387 			break;
1388 
1389 		case OVS_ACTION_ATTR_PUSH_NSH: {
1390 			u8 buffer[NSH_HDR_MAX_LEN];
1391 			struct nshhdr *nh = (struct nshhdr *)buffer;
1392 
1393 			err = nsh_hdr_from_nlattr(nla_data(a), nh,
1394 						  NSH_HDR_MAX_LEN);
1395 			if (unlikely(err))
1396 				break;
1397 			err = push_nsh(skb, key, nh);
1398 			break;
1399 		}
1400 
1401 		case OVS_ACTION_ATTR_POP_NSH:
1402 			err = pop_nsh(skb, key);
1403 			break;
1404 
1405 		case OVS_ACTION_ATTR_METER:
1406 			if (ovs_meter_execute(dp, skb, key, nla_get_u32(a))) {
1407 				consume_skb(skb);
1408 				return 0;
1409 			}
1410 			break;
1411 
1412 		case OVS_ACTION_ATTR_CLONE: {
1413 			bool last = nla_is_last(a, rem);
1414 
1415 			err = clone(dp, skb, key, a, last);
1416 			if (last)
1417 				return err;
1418 
1419 			break;
1420 		}
1421 
1422 		case OVS_ACTION_ATTR_CHECK_PKT_LEN: {
1423 			bool last = nla_is_last(a, rem);
1424 
1425 			err = execute_check_pkt_len(dp, skb, key, a, last);
1426 			if (last)
1427 				return err;
1428 
1429 			break;
1430 		}
1431 
1432 		case OVS_ACTION_ATTR_DEC_TTL:
1433 			err = execute_dec_ttl(skb, key);
1434 			if (err == -EHOSTUNREACH) {
1435 				err = dec_ttl_exception_handler(dp, skb, key,
1436 								a, true);
1437 				return err;
1438 			}
1439 			break;
1440 		}
1441 
1442 		if (unlikely(err)) {
1443 			kfree_skb(skb);
1444 			return err;
1445 		}
1446 	}
1447 
1448 	consume_skb(skb);
1449 	return 0;
1450 }
1451 
1452 /* Execute the actions on the clone of the packet. The effect of the
1453  * execution does not affect the original 'skb' nor the original 'key'.
1454  *
1455  * The execution may be deferred in case the actions can not be executed
1456  * immediately.
1457  */
1458 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
1459 			 struct sw_flow_key *key, u32 recirc_id,
1460 			 const struct nlattr *actions, int len,
1461 			 bool last, bool clone_flow_key)
1462 {
1463 	struct deferred_action *da;
1464 	struct sw_flow_key *clone;
1465 
1466 	skb = last ? skb : skb_clone(skb, GFP_ATOMIC);
1467 	if (!skb) {
1468 		/* Out of memory, skip this action.
1469 		 */
1470 		return 0;
1471 	}
1472 
1473 	/* When clone_flow_key is false, the 'key' will not be change
1474 	 * by the actions, then the 'key' can be used directly.
1475 	 * Otherwise, try to clone key from the next recursion level of
1476 	 * 'flow_keys'. If clone is successful, execute the actions
1477 	 * without deferring.
1478 	 */
1479 	clone = clone_flow_key ? clone_key(key) : key;
1480 	if (clone) {
1481 		int err = 0;
1482 
1483 		if (actions) { /* Sample action */
1484 			if (clone_flow_key)
1485 				__this_cpu_inc(exec_actions_level);
1486 
1487 			err = do_execute_actions(dp, skb, clone,
1488 						 actions, len);
1489 
1490 			if (clone_flow_key)
1491 				__this_cpu_dec(exec_actions_level);
1492 		} else { /* Recirc action */
1493 			clone->recirc_id = recirc_id;
1494 			ovs_dp_process_packet(skb, clone);
1495 		}
1496 		return err;
1497 	}
1498 
1499 	/* Out of 'flow_keys' space. Defer actions */
1500 	da = add_deferred_actions(skb, key, actions, len);
1501 	if (da) {
1502 		if (!actions) { /* Recirc action */
1503 			key = &da->pkt_key;
1504 			key->recirc_id = recirc_id;
1505 		}
1506 	} else {
1507 		/* Out of per CPU action FIFO space. Drop the 'skb' and
1508 		 * log an error.
1509 		 */
1510 		kfree_skb(skb);
1511 
1512 		if (net_ratelimit()) {
1513 			if (actions) { /* Sample action */
1514 				pr_warn("%s: deferred action limit reached, drop sample action\n",
1515 					ovs_dp_name(dp));
1516 			} else {  /* Recirc action */
1517 				pr_warn("%s: deferred action limit reached, drop recirc action\n",
1518 					ovs_dp_name(dp));
1519 			}
1520 		}
1521 	}
1522 	return 0;
1523 }
1524 
1525 static void process_deferred_actions(struct datapath *dp)
1526 {
1527 	struct action_fifo *fifo = this_cpu_ptr(action_fifos);
1528 
1529 	/* Do not touch the FIFO in case there is no deferred actions. */
1530 	if (action_fifo_is_empty(fifo))
1531 		return;
1532 
1533 	/* Finishing executing all deferred actions. */
1534 	do {
1535 		struct deferred_action *da = action_fifo_get(fifo);
1536 		struct sk_buff *skb = da->skb;
1537 		struct sw_flow_key *key = &da->pkt_key;
1538 		const struct nlattr *actions = da->actions;
1539 		int actions_len = da->actions_len;
1540 
1541 		if (actions)
1542 			do_execute_actions(dp, skb, key, actions, actions_len);
1543 		else
1544 			ovs_dp_process_packet(skb, key);
1545 	} while (!action_fifo_is_empty(fifo));
1546 
1547 	/* Reset FIFO for the next packet.  */
1548 	action_fifo_init(fifo);
1549 }
1550 
1551 /* Execute a list of actions against 'skb'. */
1552 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
1553 			const struct sw_flow_actions *acts,
1554 			struct sw_flow_key *key)
1555 {
1556 	int err, level;
1557 
1558 	level = __this_cpu_inc_return(exec_actions_level);
1559 	if (unlikely(level > OVS_RECURSION_LIMIT)) {
1560 		net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n",
1561 				     ovs_dp_name(dp));
1562 		kfree_skb(skb);
1563 		err = -ENETDOWN;
1564 		goto out;
1565 	}
1566 
1567 	OVS_CB(skb)->acts_origlen = acts->orig_len;
1568 	err = do_execute_actions(dp, skb, key,
1569 				 acts->actions, acts->actions_len);
1570 
1571 	if (level == 1)
1572 		process_deferred_actions(dp);
1573 
1574 out:
1575 	__this_cpu_dec(exec_actions_level);
1576 	return err;
1577 }
1578 
1579 int action_fifos_init(void)
1580 {
1581 	action_fifos = alloc_percpu(struct action_fifo);
1582 	if (!action_fifos)
1583 		return -ENOMEM;
1584 
1585 	flow_keys = alloc_percpu(struct action_flow_keys);
1586 	if (!flow_keys) {
1587 		free_percpu(action_fifos);
1588 		return -ENOMEM;
1589 	}
1590 
1591 	return 0;
1592 }
1593 
1594 void action_fifos_exit(void)
1595 {
1596 	free_percpu(action_fifos);
1597 	free_percpu(flow_keys);
1598 }
1599