xref: /openbmc/linux/net/openvswitch/actions.c (revision 6cbbfe1c)
1 /*
2  * Copyright (c) 2007-2014 Nicira, Inc.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of version 2 of the GNU General Public
6  * License as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16  * 02110-1301, USA
17  */
18 
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 
21 #include <linux/skbuff.h>
22 #include <linux/in.h>
23 #include <linux/ip.h>
24 #include <linux/openvswitch.h>
25 #include <linux/sctp.h>
26 #include <linux/tcp.h>
27 #include <linux/udp.h>
28 #include <linux/in6.h>
29 #include <linux/if_arp.h>
30 #include <linux/if_vlan.h>
31 
32 #include <net/ip.h>
33 #include <net/ipv6.h>
34 #include <net/checksum.h>
35 #include <net/dsfield.h>
36 #include <net/mpls.h>
37 #include <net/sctp/checksum.h>
38 
39 #include "datapath.h"
40 #include "flow.h"
41 #include "vport.h"
42 
43 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
44 			      struct sw_flow_key *key,
45 			      const struct nlattr *attr, int len);
46 
47 struct deferred_action {
48 	struct sk_buff *skb;
49 	const struct nlattr *actions;
50 
51 	/* Store pkt_key clone when creating deferred action. */
52 	struct sw_flow_key pkt_key;
53 };
54 
55 #define DEFERRED_ACTION_FIFO_SIZE 10
56 struct action_fifo {
57 	int head;
58 	int tail;
59 	/* Deferred action fifo queue storage. */
60 	struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
61 };
62 
63 static struct action_fifo __percpu *action_fifos;
64 static DEFINE_PER_CPU(int, exec_actions_level);
65 
66 static void action_fifo_init(struct action_fifo *fifo)
67 {
68 	fifo->head = 0;
69 	fifo->tail = 0;
70 }
71 
72 static bool action_fifo_is_empty(const struct action_fifo *fifo)
73 {
74 	return (fifo->head == fifo->tail);
75 }
76 
77 static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
78 {
79 	if (action_fifo_is_empty(fifo))
80 		return NULL;
81 
82 	return &fifo->fifo[fifo->tail++];
83 }
84 
85 static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
86 {
87 	if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
88 		return NULL;
89 
90 	return &fifo->fifo[fifo->head++];
91 }
92 
93 /* Return true if fifo is not full */
94 static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
95 						    const struct sw_flow_key *key,
96 						    const struct nlattr *attr)
97 {
98 	struct action_fifo *fifo;
99 	struct deferred_action *da;
100 
101 	fifo = this_cpu_ptr(action_fifos);
102 	da = action_fifo_put(fifo);
103 	if (da) {
104 		da->skb = skb;
105 		da->actions = attr;
106 		da->pkt_key = *key;
107 	}
108 
109 	return da;
110 }
111 
112 static void invalidate_flow_key(struct sw_flow_key *key)
113 {
114 	key->eth.type = htons(0);
115 }
116 
117 static bool is_flow_key_valid(const struct sw_flow_key *key)
118 {
119 	return !!key->eth.type;
120 }
121 
122 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
123 		     const struct ovs_action_push_mpls *mpls)
124 {
125 	__be32 *new_mpls_lse;
126 	struct ethhdr *hdr;
127 
128 	/* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
129 	if (skb->encapsulation)
130 		return -ENOTSUPP;
131 
132 	if (skb_cow_head(skb, MPLS_HLEN) < 0)
133 		return -ENOMEM;
134 
135 	skb_push(skb, MPLS_HLEN);
136 	memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
137 		skb->mac_len);
138 	skb_reset_mac_header(skb);
139 
140 	new_mpls_lse = (__be32 *)skb_mpls_header(skb);
141 	*new_mpls_lse = mpls->mpls_lse;
142 
143 	if (skb->ip_summed == CHECKSUM_COMPLETE)
144 		skb->csum = csum_add(skb->csum, csum_partial(new_mpls_lse,
145 							     MPLS_HLEN, 0));
146 
147 	hdr = eth_hdr(skb);
148 	hdr->h_proto = mpls->mpls_ethertype;
149 
150 	if (!skb->inner_protocol)
151 		skb_set_inner_protocol(skb, skb->protocol);
152 	skb->protocol = mpls->mpls_ethertype;
153 
154 	invalidate_flow_key(key);
155 	return 0;
156 }
157 
158 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
159 		    const __be16 ethertype)
160 {
161 	struct ethhdr *hdr;
162 	int err;
163 
164 	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
165 	if (unlikely(err))
166 		return err;
167 
168 	skb_postpull_rcsum(skb, skb_mpls_header(skb), MPLS_HLEN);
169 
170 	memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
171 		skb->mac_len);
172 
173 	__skb_pull(skb, MPLS_HLEN);
174 	skb_reset_mac_header(skb);
175 
176 	/* skb_mpls_header() is used to locate the ethertype
177 	 * field correctly in the presence of VLAN tags.
178 	 */
179 	hdr = (struct ethhdr *)(skb_mpls_header(skb) - ETH_HLEN);
180 	hdr->h_proto = ethertype;
181 	if (eth_p_mpls(skb->protocol))
182 		skb->protocol = ethertype;
183 
184 	invalidate_flow_key(key);
185 	return 0;
186 }
187 
188 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key,
189 		    const __be32 *mpls_lse)
190 {
191 	__be32 *stack;
192 	int err;
193 
194 	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
195 	if (unlikely(err))
196 		return err;
197 
198 	stack = (__be32 *)skb_mpls_header(skb);
199 	if (skb->ip_summed == CHECKSUM_COMPLETE) {
200 		__be32 diff[] = { ~(*stack), *mpls_lse };
201 		skb->csum = ~csum_partial((char *)diff, sizeof(diff),
202 					  ~skb->csum);
203 	}
204 
205 	*stack = *mpls_lse;
206 	key->mpls.top_lse = *mpls_lse;
207 	return 0;
208 }
209 
210 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
211 {
212 	int err;
213 
214 	err = skb_vlan_pop(skb);
215 	if (vlan_tx_tag_present(skb))
216 		invalidate_flow_key(key);
217 	else
218 		key->eth.tci = 0;
219 	return err;
220 }
221 
222 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
223 		     const struct ovs_action_push_vlan *vlan)
224 {
225 	if (vlan_tx_tag_present(skb))
226 		invalidate_flow_key(key);
227 	else
228 		key->eth.tci = vlan->vlan_tci;
229 	return skb_vlan_push(skb, vlan->vlan_tpid,
230 			     ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
231 }
232 
233 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key,
234 			const struct ovs_key_ethernet *eth_key)
235 {
236 	int err;
237 	err = skb_ensure_writable(skb, ETH_HLEN);
238 	if (unlikely(err))
239 		return err;
240 
241 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
242 
243 	ether_addr_copy(eth_hdr(skb)->h_source, eth_key->eth_src);
244 	ether_addr_copy(eth_hdr(skb)->h_dest, eth_key->eth_dst);
245 
246 	ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
247 
248 	ether_addr_copy(key->eth.src, eth_key->eth_src);
249 	ether_addr_copy(key->eth.dst, eth_key->eth_dst);
250 	return 0;
251 }
252 
253 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
254 			__be32 *addr, __be32 new_addr)
255 {
256 	int transport_len = skb->len - skb_transport_offset(skb);
257 
258 	if (nh->protocol == IPPROTO_TCP) {
259 		if (likely(transport_len >= sizeof(struct tcphdr)))
260 			inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
261 						 *addr, new_addr, 1);
262 	} else if (nh->protocol == IPPROTO_UDP) {
263 		if (likely(transport_len >= sizeof(struct udphdr))) {
264 			struct udphdr *uh = udp_hdr(skb);
265 
266 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
267 				inet_proto_csum_replace4(&uh->check, skb,
268 							 *addr, new_addr, 1);
269 				if (!uh->check)
270 					uh->check = CSUM_MANGLED_0;
271 			}
272 		}
273 	}
274 
275 	csum_replace4(&nh->check, *addr, new_addr);
276 	skb_clear_hash(skb);
277 	*addr = new_addr;
278 }
279 
280 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
281 				 __be32 addr[4], const __be32 new_addr[4])
282 {
283 	int transport_len = skb->len - skb_transport_offset(skb);
284 
285 	if (l4_proto == NEXTHDR_TCP) {
286 		if (likely(transport_len >= sizeof(struct tcphdr)))
287 			inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
288 						  addr, new_addr, 1);
289 	} else if (l4_proto == NEXTHDR_UDP) {
290 		if (likely(transport_len >= sizeof(struct udphdr))) {
291 			struct udphdr *uh = udp_hdr(skb);
292 
293 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
294 				inet_proto_csum_replace16(&uh->check, skb,
295 							  addr, new_addr, 1);
296 				if (!uh->check)
297 					uh->check = CSUM_MANGLED_0;
298 			}
299 		}
300 	} else if (l4_proto == NEXTHDR_ICMP) {
301 		if (likely(transport_len >= sizeof(struct icmp6hdr)))
302 			inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
303 						  skb, addr, new_addr, 1);
304 	}
305 }
306 
307 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
308 			  __be32 addr[4], const __be32 new_addr[4],
309 			  bool recalculate_csum)
310 {
311 	if (recalculate_csum)
312 		update_ipv6_checksum(skb, l4_proto, addr, new_addr);
313 
314 	skb_clear_hash(skb);
315 	memcpy(addr, new_addr, sizeof(__be32[4]));
316 }
317 
318 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
319 {
320 	nh->priority = tc >> 4;
321 	nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
322 }
323 
324 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
325 {
326 	nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
327 	nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
328 	nh->flow_lbl[2] = fl & 0x000000FF;
329 }
330 
331 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
332 {
333 	csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
334 	nh->ttl = new_ttl;
335 }
336 
337 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *key,
338 		    const struct ovs_key_ipv4 *ipv4_key)
339 {
340 	struct iphdr *nh;
341 	int err;
342 
343 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
344 				  sizeof(struct iphdr));
345 	if (unlikely(err))
346 		return err;
347 
348 	nh = ip_hdr(skb);
349 
350 	if (ipv4_key->ipv4_src != nh->saddr) {
351 		set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
352 		key->ipv4.addr.src = ipv4_key->ipv4_src;
353 	}
354 
355 	if (ipv4_key->ipv4_dst != nh->daddr) {
356 		set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
357 		key->ipv4.addr.dst = ipv4_key->ipv4_dst;
358 	}
359 
360 	if (ipv4_key->ipv4_tos != nh->tos) {
361 		ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
362 		key->ip.tos = nh->tos;
363 	}
364 
365 	if (ipv4_key->ipv4_ttl != nh->ttl) {
366 		set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
367 		key->ip.ttl = ipv4_key->ipv4_ttl;
368 	}
369 
370 	return 0;
371 }
372 
373 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *key,
374 		    const struct ovs_key_ipv6 *ipv6_key)
375 {
376 	struct ipv6hdr *nh;
377 	int err;
378 	__be32 *saddr;
379 	__be32 *daddr;
380 
381 	err = skb_ensure_writable(skb, skb_network_offset(skb) +
382 				  sizeof(struct ipv6hdr));
383 	if (unlikely(err))
384 		return err;
385 
386 	nh = ipv6_hdr(skb);
387 	saddr = (__be32 *)&nh->saddr;
388 	daddr = (__be32 *)&nh->daddr;
389 
390 	if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src))) {
391 		set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
392 			      ipv6_key->ipv6_src, true);
393 		memcpy(&key->ipv6.addr.src, ipv6_key->ipv6_src,
394 		       sizeof(ipv6_key->ipv6_src));
395 	}
396 
397 	if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
398 		unsigned int offset = 0;
399 		int flags = IP6_FH_F_SKIP_RH;
400 		bool recalc_csum = true;
401 
402 		if (ipv6_ext_hdr(nh->nexthdr))
403 			recalc_csum = ipv6_find_hdr(skb, &offset,
404 						    NEXTHDR_ROUTING, NULL,
405 						    &flags) != NEXTHDR_ROUTING;
406 
407 		set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
408 			      ipv6_key->ipv6_dst, recalc_csum);
409 		memcpy(&key->ipv6.addr.dst, ipv6_key->ipv6_dst,
410 		       sizeof(ipv6_key->ipv6_dst));
411 	}
412 
413 	set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
414 	key->ip.tos = ipv6_get_dsfield(nh);
415 
416 	set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
417 	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
418 
419 	nh->hop_limit = ipv6_key->ipv6_hlimit;
420 	key->ip.ttl = ipv6_key->ipv6_hlimit;
421 	return 0;
422 }
423 
424 /* Must follow skb_ensure_writable() since that can move the skb data. */
425 static void set_tp_port(struct sk_buff *skb, __be16 *port,
426 			 __be16 new_port, __sum16 *check)
427 {
428 	inet_proto_csum_replace2(check, skb, *port, new_port, 0);
429 	*port = new_port;
430 	skb_clear_hash(skb);
431 }
432 
433 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
434 {
435 	struct udphdr *uh = udp_hdr(skb);
436 
437 	if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
438 		set_tp_port(skb, port, new_port, &uh->check);
439 
440 		if (!uh->check)
441 			uh->check = CSUM_MANGLED_0;
442 	} else {
443 		*port = new_port;
444 		skb_clear_hash(skb);
445 	}
446 }
447 
448 static int set_udp(struct sk_buff *skb, struct sw_flow_key *key,
449 		   const struct ovs_key_udp *udp_port_key)
450 {
451 	struct udphdr *uh;
452 	int err;
453 
454 	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
455 				  sizeof(struct udphdr));
456 	if (unlikely(err))
457 		return err;
458 
459 	uh = udp_hdr(skb);
460 	if (udp_port_key->udp_src != uh->source) {
461 		set_udp_port(skb, &uh->source, udp_port_key->udp_src);
462 		key->tp.src = udp_port_key->udp_src;
463 	}
464 
465 	if (udp_port_key->udp_dst != uh->dest) {
466 		set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
467 		key->tp.dst = udp_port_key->udp_dst;
468 	}
469 
470 	return 0;
471 }
472 
473 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *key,
474 		   const struct ovs_key_tcp *tcp_port_key)
475 {
476 	struct tcphdr *th;
477 	int err;
478 
479 	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
480 				  sizeof(struct tcphdr));
481 	if (unlikely(err))
482 		return err;
483 
484 	th = tcp_hdr(skb);
485 	if (tcp_port_key->tcp_src != th->source) {
486 		set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
487 		key->tp.src = tcp_port_key->tcp_src;
488 	}
489 
490 	if (tcp_port_key->tcp_dst != th->dest) {
491 		set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
492 		key->tp.dst = tcp_port_key->tcp_dst;
493 	}
494 
495 	return 0;
496 }
497 
498 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *key,
499 		    const struct ovs_key_sctp *sctp_port_key)
500 {
501 	struct sctphdr *sh;
502 	int err;
503 	unsigned int sctphoff = skb_transport_offset(skb);
504 
505 	err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
506 	if (unlikely(err))
507 		return err;
508 
509 	sh = sctp_hdr(skb);
510 	if (sctp_port_key->sctp_src != sh->source ||
511 	    sctp_port_key->sctp_dst != sh->dest) {
512 		__le32 old_correct_csum, new_csum, old_csum;
513 
514 		old_csum = sh->checksum;
515 		old_correct_csum = sctp_compute_cksum(skb, sctphoff);
516 
517 		sh->source = sctp_port_key->sctp_src;
518 		sh->dest = sctp_port_key->sctp_dst;
519 
520 		new_csum = sctp_compute_cksum(skb, sctphoff);
521 
522 		/* Carry any checksum errors through. */
523 		sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
524 
525 		skb_clear_hash(skb);
526 		key->tp.src = sctp_port_key->sctp_src;
527 		key->tp.dst = sctp_port_key->sctp_dst;
528 	}
529 
530 	return 0;
531 }
532 
533 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
534 {
535 	struct vport *vport = ovs_vport_rcu(dp, out_port);
536 
537 	if (likely(vport))
538 		ovs_vport_send(vport, skb);
539 	else
540 		kfree_skb(skb);
541 }
542 
543 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
544 			    struct sw_flow_key *key, const struct nlattr *attr)
545 {
546 	struct ovs_tunnel_info info;
547 	struct dp_upcall_info upcall;
548 	const struct nlattr *a;
549 	int rem;
550 
551 	upcall.cmd = OVS_PACKET_CMD_ACTION;
552 	upcall.userdata = NULL;
553 	upcall.portid = 0;
554 	upcall.egress_tun_info = NULL;
555 
556 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
557 		 a = nla_next(a, &rem)) {
558 		switch (nla_type(a)) {
559 		case OVS_USERSPACE_ATTR_USERDATA:
560 			upcall.userdata = a;
561 			break;
562 
563 		case OVS_USERSPACE_ATTR_PID:
564 			upcall.portid = nla_get_u32(a);
565 			break;
566 
567 		case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
568 			/* Get out tunnel info. */
569 			struct vport *vport;
570 
571 			vport = ovs_vport_rcu(dp, nla_get_u32(a));
572 			if (vport) {
573 				int err;
574 
575 				err = ovs_vport_get_egress_tun_info(vport, skb,
576 								    &info);
577 				if (!err)
578 					upcall.egress_tun_info = &info;
579 			}
580 			break;
581 		}
582 
583 		} /* End of switch. */
584 	}
585 
586 	return ovs_dp_upcall(dp, skb, key, &upcall);
587 }
588 
589 static int sample(struct datapath *dp, struct sk_buff *skb,
590 		  struct sw_flow_key *key, const struct nlattr *attr)
591 {
592 	const struct nlattr *acts_list = NULL;
593 	const struct nlattr *a;
594 	int rem;
595 
596 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
597 		 a = nla_next(a, &rem)) {
598 		switch (nla_type(a)) {
599 		case OVS_SAMPLE_ATTR_PROBABILITY:
600 			if (prandom_u32() >= nla_get_u32(a))
601 				return 0;
602 			break;
603 
604 		case OVS_SAMPLE_ATTR_ACTIONS:
605 			acts_list = a;
606 			break;
607 		}
608 	}
609 
610 	rem = nla_len(acts_list);
611 	a = nla_data(acts_list);
612 
613 	/* Actions list is empty, do nothing */
614 	if (unlikely(!rem))
615 		return 0;
616 
617 	/* The only known usage of sample action is having a single user-space
618 	 * action. Treat this usage as a special case.
619 	 * The output_userspace() should clone the skb to be sent to the
620 	 * user space. This skb will be consumed by its caller.
621 	 */
622 	if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
623 		   nla_is_last(a, rem)))
624 		return output_userspace(dp, skb, key, a);
625 
626 	skb = skb_clone(skb, GFP_ATOMIC);
627 	if (!skb)
628 		/* Skip the sample action when out of memory. */
629 		return 0;
630 
631 	if (!add_deferred_actions(skb, key, a)) {
632 		if (net_ratelimit())
633 			pr_warn("%s: deferred actions limit reached, dropping sample action\n",
634 				ovs_dp_name(dp));
635 
636 		kfree_skb(skb);
637 	}
638 	return 0;
639 }
640 
641 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
642 			 const struct nlattr *attr)
643 {
644 	struct ovs_action_hash *hash_act = nla_data(attr);
645 	u32 hash = 0;
646 
647 	/* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
648 	hash = skb_get_hash(skb);
649 	hash = jhash_1word(hash, hash_act->hash_basis);
650 	if (!hash)
651 		hash = 0x1;
652 
653 	key->ovs_flow_hash = hash;
654 }
655 
656 static int execute_set_action(struct sk_buff *skb, struct sw_flow_key *key,
657 			      const struct nlattr *nested_attr)
658 {
659 	int err = 0;
660 
661 	switch (nla_type(nested_attr)) {
662 	case OVS_KEY_ATTR_PRIORITY:
663 		skb->priority = nla_get_u32(nested_attr);
664 		key->phy.priority = skb->priority;
665 		break;
666 
667 	case OVS_KEY_ATTR_SKB_MARK:
668 		skb->mark = nla_get_u32(nested_attr);
669 		key->phy.skb_mark = skb->mark;
670 		break;
671 
672 	case OVS_KEY_ATTR_TUNNEL_INFO:
673 		OVS_CB(skb)->egress_tun_info = nla_data(nested_attr);
674 		break;
675 
676 	case OVS_KEY_ATTR_ETHERNET:
677 		err = set_eth_addr(skb, key, nla_data(nested_attr));
678 		break;
679 
680 	case OVS_KEY_ATTR_IPV4:
681 		err = set_ipv4(skb, key, nla_data(nested_attr));
682 		break;
683 
684 	case OVS_KEY_ATTR_IPV6:
685 		err = set_ipv6(skb, key, nla_data(nested_attr));
686 		break;
687 
688 	case OVS_KEY_ATTR_TCP:
689 		err = set_tcp(skb, key, nla_data(nested_attr));
690 		break;
691 
692 	case OVS_KEY_ATTR_UDP:
693 		err = set_udp(skb, key, nla_data(nested_attr));
694 		break;
695 
696 	case OVS_KEY_ATTR_SCTP:
697 		err = set_sctp(skb, key, nla_data(nested_attr));
698 		break;
699 
700 	case OVS_KEY_ATTR_MPLS:
701 		err = set_mpls(skb, key, nla_data(nested_attr));
702 		break;
703 	}
704 
705 	return err;
706 }
707 
708 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
709 			  struct sw_flow_key *key,
710 			  const struct nlattr *a, int rem)
711 {
712 	struct deferred_action *da;
713 
714 	if (!is_flow_key_valid(key)) {
715 		int err;
716 
717 		err = ovs_flow_key_update(skb, key);
718 		if (err)
719 			return err;
720 	}
721 	BUG_ON(!is_flow_key_valid(key));
722 
723 	if (!nla_is_last(a, rem)) {
724 		/* Recirc action is the not the last action
725 		 * of the action list, need to clone the skb.
726 		 */
727 		skb = skb_clone(skb, GFP_ATOMIC);
728 
729 		/* Skip the recirc action when out of memory, but
730 		 * continue on with the rest of the action list.
731 		 */
732 		if (!skb)
733 			return 0;
734 	}
735 
736 	da = add_deferred_actions(skb, key, NULL);
737 	if (da) {
738 		da->pkt_key.recirc_id = nla_get_u32(a);
739 	} else {
740 		kfree_skb(skb);
741 
742 		if (net_ratelimit())
743 			pr_warn("%s: deferred action limit reached, drop recirc action\n",
744 				ovs_dp_name(dp));
745 	}
746 
747 	return 0;
748 }
749 
750 /* Execute a list of actions against 'skb'. */
751 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
752 			      struct sw_flow_key *key,
753 			      const struct nlattr *attr, int len)
754 {
755 	/* Every output action needs a separate clone of 'skb', but the common
756 	 * case is just a single output action, so that doing a clone and
757 	 * then freeing the original skbuff is wasteful.  So the following code
758 	 * is slightly obscure just to avoid that.
759 	 */
760 	int prev_port = -1;
761 	const struct nlattr *a;
762 	int rem;
763 
764 	for (a = attr, rem = len; rem > 0;
765 	     a = nla_next(a, &rem)) {
766 		int err = 0;
767 
768 		if (unlikely(prev_port != -1)) {
769 			struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
770 
771 			if (out_skb)
772 				do_output(dp, out_skb, prev_port);
773 
774 			prev_port = -1;
775 		}
776 
777 		switch (nla_type(a)) {
778 		case OVS_ACTION_ATTR_OUTPUT:
779 			prev_port = nla_get_u32(a);
780 			break;
781 
782 		case OVS_ACTION_ATTR_USERSPACE:
783 			output_userspace(dp, skb, key, a);
784 			break;
785 
786 		case OVS_ACTION_ATTR_HASH:
787 			execute_hash(skb, key, a);
788 			break;
789 
790 		case OVS_ACTION_ATTR_PUSH_MPLS:
791 			err = push_mpls(skb, key, nla_data(a));
792 			break;
793 
794 		case OVS_ACTION_ATTR_POP_MPLS:
795 			err = pop_mpls(skb, key, nla_get_be16(a));
796 			break;
797 
798 		case OVS_ACTION_ATTR_PUSH_VLAN:
799 			err = push_vlan(skb, key, nla_data(a));
800 			break;
801 
802 		case OVS_ACTION_ATTR_POP_VLAN:
803 			err = pop_vlan(skb, key);
804 			break;
805 
806 		case OVS_ACTION_ATTR_RECIRC:
807 			err = execute_recirc(dp, skb, key, a, rem);
808 			if (nla_is_last(a, rem)) {
809 				/* If this is the last action, the skb has
810 				 * been consumed or freed.
811 				 * Return immediately.
812 				 */
813 				return err;
814 			}
815 			break;
816 
817 		case OVS_ACTION_ATTR_SET:
818 			err = execute_set_action(skb, key, nla_data(a));
819 			break;
820 
821 		case OVS_ACTION_ATTR_SAMPLE:
822 			err = sample(dp, skb, key, a);
823 			break;
824 		}
825 
826 		if (unlikely(err)) {
827 			kfree_skb(skb);
828 			return err;
829 		}
830 	}
831 
832 	if (prev_port != -1)
833 		do_output(dp, skb, prev_port);
834 	else
835 		consume_skb(skb);
836 
837 	return 0;
838 }
839 
840 static void process_deferred_actions(struct datapath *dp)
841 {
842 	struct action_fifo *fifo = this_cpu_ptr(action_fifos);
843 
844 	/* Do not touch the FIFO in case there is no deferred actions. */
845 	if (action_fifo_is_empty(fifo))
846 		return;
847 
848 	/* Finishing executing all deferred actions. */
849 	do {
850 		struct deferred_action *da = action_fifo_get(fifo);
851 		struct sk_buff *skb = da->skb;
852 		struct sw_flow_key *key = &da->pkt_key;
853 		const struct nlattr *actions = da->actions;
854 
855 		if (actions)
856 			do_execute_actions(dp, skb, key, actions,
857 					   nla_len(actions));
858 		else
859 			ovs_dp_process_packet(skb, key);
860 	} while (!action_fifo_is_empty(fifo));
861 
862 	/* Reset FIFO for the next packet.  */
863 	action_fifo_init(fifo);
864 }
865 
866 /* Execute a list of actions against 'skb'. */
867 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
868 			const struct sw_flow_actions *acts,
869 			struct sw_flow_key *key)
870 {
871 	int level = this_cpu_read(exec_actions_level);
872 	int err;
873 
874 	this_cpu_inc(exec_actions_level);
875 	OVS_CB(skb)->egress_tun_info = NULL;
876 	err = do_execute_actions(dp, skb, key,
877 				 acts->actions, acts->actions_len);
878 
879 	if (!level)
880 		process_deferred_actions(dp);
881 
882 	this_cpu_dec(exec_actions_level);
883 	return err;
884 }
885 
886 int action_fifos_init(void)
887 {
888 	action_fifos = alloc_percpu(struct action_fifo);
889 	if (!action_fifos)
890 		return -ENOMEM;
891 
892 	return 0;
893 }
894 
895 void action_fifos_exit(void)
896 {
897 	free_percpu(action_fifos);
898 }
899