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[deliverable/linux.git] / actions.c
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/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
47 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
48 struct sw_flow_key *key,
49 const struct nlattr *attr, int len);
50
51 struct deferred_action {
52 struct sk_buff *skb;
53 const struct nlattr *actions;
54
55 /* Store pkt_key clone when creating deferred action. */
56 struct sw_flow_key pkt_key;
57 };
58
59 #define MAX_L2_LEN (VLAN_ETH_HLEN + 3 * MPLS_HLEN)
60 struct ovs_frag_data {
61 unsigned long dst;
62 struct vport *vport;
63 struct ovs_skb_cb cb;
64 __be16 inner_protocol;
65 __u16 vlan_tci;
66 __be16 vlan_proto;
67 unsigned int l2_len;
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 struct action_fifo {
75 int head;
76 int tail;
77 /* Deferred action fifo queue storage. */
78 struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
79 };
80
81 static struct action_fifo __percpu *action_fifos;
82 static DEFINE_PER_CPU(int, exec_actions_level);
83
84 static void action_fifo_init(struct action_fifo *fifo)
85 {
86 fifo->head = 0;
87 fifo->tail = 0;
88 }
89
90 static bool action_fifo_is_empty(const struct action_fifo *fifo)
91 {
92 return (fifo->head == fifo->tail);
93 }
94
95 static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
96 {
97 if (action_fifo_is_empty(fifo))
98 return NULL;
99
100 return &fifo->fifo[fifo->tail++];
101 }
102
103 static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
104 {
105 if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
106 return NULL;
107
108 return &fifo->fifo[fifo->head++];
109 }
110
111 /* Return true if fifo is not full */
112 static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
113 const struct sw_flow_key *key,
114 const struct nlattr *attr)
115 {
116 struct action_fifo *fifo;
117 struct deferred_action *da;
118
119 fifo = this_cpu_ptr(action_fifos);
120 da = action_fifo_put(fifo);
121 if (da) {
122 da->skb = skb;
123 da->actions = attr;
124 da->pkt_key = *key;
125 }
126
127 return da;
128 }
129
130 static void invalidate_flow_key(struct sw_flow_key *key)
131 {
132 key->eth.type = htons(0);
133 }
134
135 static bool is_flow_key_valid(const struct sw_flow_key *key)
136 {
137 return !!key->eth.type;
138 }
139
140 static void update_ethertype(struct sk_buff *skb, struct ethhdr *hdr,
141 __be16 ethertype)
142 {
143 if (skb->ip_summed == CHECKSUM_COMPLETE) {
144 __be16 diff[] = { ~(hdr->h_proto), ethertype };
145
146 skb->csum = ~csum_partial((char *)diff, sizeof(diff),
147 ~skb->csum);
148 }
149
150 hdr->h_proto = ethertype;
151 }
152
153 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
154 const struct ovs_action_push_mpls *mpls)
155 {
156 __be32 *new_mpls_lse;
157
158 /* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
159 if (skb->encapsulation)
160 return -ENOTSUPP;
161
162 if (skb_cow_head(skb, MPLS_HLEN) < 0)
163 return -ENOMEM;
164
165 if (!skb->inner_protocol) {
166 skb_set_inner_network_header(skb, skb->mac_len);
167 skb_set_inner_protocol(skb, skb->protocol);
168 }
169
170 skb_push(skb, MPLS_HLEN);
171 memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
172 skb->mac_len);
173 skb_reset_mac_header(skb);
174 skb_set_network_header(skb, skb->mac_len);
175
176 new_mpls_lse = (__be32 *)skb_mpls_header(skb);
177 *new_mpls_lse = mpls->mpls_lse;
178
179 skb_postpush_rcsum(skb, new_mpls_lse, MPLS_HLEN);
180
181 update_ethertype(skb, eth_hdr(skb), mpls->mpls_ethertype);
182 skb->protocol = mpls->mpls_ethertype;
183
184 invalidate_flow_key(key);
185 return 0;
186 }
187
188 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
189 const __be16 ethertype)
190 {
191 struct ethhdr *hdr;
192 int err;
193
194 err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
195 if (unlikely(err))
196 return err;
197
198 skb_postpull_rcsum(skb, skb_mpls_header(skb), MPLS_HLEN);
199
200 memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
201 skb->mac_len);
202
203 __skb_pull(skb, MPLS_HLEN);
204 skb_reset_mac_header(skb);
205 skb_set_network_header(skb, skb->mac_len);
206
207 /* skb_mpls_header() is used to locate the ethertype
208 * field correctly in the presence of VLAN tags.
209 */
210 hdr = (struct ethhdr *)(skb_mpls_header(skb) - ETH_HLEN);
211 update_ethertype(skb, hdr, ethertype);
212 if (eth_p_mpls(skb->protocol))
213 skb->protocol = ethertype;
214
215 invalidate_flow_key(key);
216 return 0;
217 }
218
219 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
220 const __be32 *mpls_lse, const __be32 *mask)
221 {
222 __be32 *stack;
223 __be32 lse;
224 int err;
225
226 err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
227 if (unlikely(err))
228 return err;
229
230 stack = (__be32 *)skb_mpls_header(skb);
231 lse = OVS_MASKED(*stack, *mpls_lse, *mask);
232 if (skb->ip_summed == CHECKSUM_COMPLETE) {
233 __be32 diff[] = { ~(*stack), lse };
234
235 skb->csum = ~csum_partial((char *)diff, sizeof(diff),
236 ~skb->csum);
237 }
238
239 *stack = lse;
240 flow_key->mpls.top_lse = lse;
241 return 0;
242 }
243
244 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
245 {
246 int err;
247
248 err = skb_vlan_pop(skb);
249 if (skb_vlan_tag_present(skb)) {
250 invalidate_flow_key(key);
251 } else {
252 key->eth.vlan.tci = 0;
253 key->eth.vlan.tpid = 0;
254 }
255 return err;
256 }
257
258 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
259 const struct ovs_action_push_vlan *vlan)
260 {
261 if (skb_vlan_tag_present(skb)) {
262 invalidate_flow_key(key);
263 } else {
264 key->eth.vlan.tci = vlan->vlan_tci;
265 key->eth.vlan.tpid = vlan->vlan_tpid;
266 }
267 return skb_vlan_push(skb, vlan->vlan_tpid,
268 ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
269 }
270
271 /* 'src' is already properly masked. */
272 static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
273 {
274 u16 *dst = (u16 *)dst_;
275 const u16 *src = (const u16 *)src_;
276 const u16 *mask = (const u16 *)mask_;
277
278 OVS_SET_MASKED(dst[0], src[0], mask[0]);
279 OVS_SET_MASKED(dst[1], src[1], mask[1]);
280 OVS_SET_MASKED(dst[2], src[2], mask[2]);
281 }
282
283 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
284 const struct ovs_key_ethernet *key,
285 const struct ovs_key_ethernet *mask)
286 {
287 int err;
288
289 err = skb_ensure_writable(skb, ETH_HLEN);
290 if (unlikely(err))
291 return err;
292
293 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
294
295 ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
296 mask->eth_src);
297 ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
298 mask->eth_dst);
299
300 skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
301
302 ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
303 ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
304 return 0;
305 }
306
307 static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
308 __be32 addr, __be32 new_addr)
309 {
310 int transport_len = skb->len - skb_transport_offset(skb);
311
312 if (nh->frag_off & htons(IP_OFFSET))
313 return;
314
315 if (nh->protocol == IPPROTO_TCP) {
316 if (likely(transport_len >= sizeof(struct tcphdr)))
317 inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
318 addr, new_addr, true);
319 } else if (nh->protocol == IPPROTO_UDP) {
320 if (likely(transport_len >= sizeof(struct udphdr))) {
321 struct udphdr *uh = udp_hdr(skb);
322
323 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
324 inet_proto_csum_replace4(&uh->check, skb,
325 addr, new_addr, true);
326 if (!uh->check)
327 uh->check = CSUM_MANGLED_0;
328 }
329 }
330 }
331 }
332
333 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
334 __be32 *addr, __be32 new_addr)
335 {
336 update_ip_l4_checksum(skb, nh, *addr, new_addr);
337 csum_replace4(&nh->check, *addr, new_addr);
338 skb_clear_hash(skb);
339 *addr = new_addr;
340 }
341
342 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
343 __be32 addr[4], const __be32 new_addr[4])
344 {
345 int transport_len = skb->len - skb_transport_offset(skb);
346
347 if (l4_proto == NEXTHDR_TCP) {
348 if (likely(transport_len >= sizeof(struct tcphdr)))
349 inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
350 addr, new_addr, true);
351 } else if (l4_proto == NEXTHDR_UDP) {
352 if (likely(transport_len >= sizeof(struct udphdr))) {
353 struct udphdr *uh = udp_hdr(skb);
354
355 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
356 inet_proto_csum_replace16(&uh->check, skb,
357 addr, new_addr, true);
358 if (!uh->check)
359 uh->check = CSUM_MANGLED_0;
360 }
361 }
362 } else if (l4_proto == NEXTHDR_ICMP) {
363 if (likely(transport_len >= sizeof(struct icmp6hdr)))
364 inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
365 skb, addr, new_addr, true);
366 }
367 }
368
369 static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
370 const __be32 mask[4], __be32 masked[4])
371 {
372 masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
373 masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
374 masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
375 masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
376 }
377
378 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
379 __be32 addr[4], const __be32 new_addr[4],
380 bool recalculate_csum)
381 {
382 if (recalculate_csum)
383 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
384
385 skb_clear_hash(skb);
386 memcpy(addr, new_addr, sizeof(__be32[4]));
387 }
388
389 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
390 {
391 /* Bits 21-24 are always unmasked, so this retains their values. */
392 OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
393 OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
394 OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
395 }
396
397 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
398 u8 mask)
399 {
400 new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);
401
402 csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
403 nh->ttl = new_ttl;
404 }
405
406 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
407 const struct ovs_key_ipv4 *key,
408 const struct ovs_key_ipv4 *mask)
409 {
410 struct iphdr *nh;
411 __be32 new_addr;
412 int err;
413
414 err = skb_ensure_writable(skb, skb_network_offset(skb) +
415 sizeof(struct iphdr));
416 if (unlikely(err))
417 return err;
418
419 nh = ip_hdr(skb);
420
421 /* Setting an IP addresses is typically only a side effect of
422 * matching on them in the current userspace implementation, so it
423 * makes sense to check if the value actually changed.
424 */
425 if (mask->ipv4_src) {
426 new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
427
428 if (unlikely(new_addr != nh->saddr)) {
429 set_ip_addr(skb, nh, &nh->saddr, new_addr);
430 flow_key->ipv4.addr.src = new_addr;
431 }
432 }
433 if (mask->ipv4_dst) {
434 new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
435
436 if (unlikely(new_addr != nh->daddr)) {
437 set_ip_addr(skb, nh, &nh->daddr, new_addr);
438 flow_key->ipv4.addr.dst = new_addr;
439 }
440 }
441 if (mask->ipv4_tos) {
442 ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
443 flow_key->ip.tos = nh->tos;
444 }
445 if (mask->ipv4_ttl) {
446 set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
447 flow_key->ip.ttl = nh->ttl;
448 }
449
450 return 0;
451 }
452
453 static bool is_ipv6_mask_nonzero(const __be32 addr[4])
454 {
455 return !!(addr[0] | addr[1] | addr[2] | addr[3]);
456 }
457
458 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
459 const struct ovs_key_ipv6 *key,
460 const struct ovs_key_ipv6 *mask)
461 {
462 struct ipv6hdr *nh;
463 int err;
464
465 err = skb_ensure_writable(skb, skb_network_offset(skb) +
466 sizeof(struct ipv6hdr));
467 if (unlikely(err))
468 return err;
469
470 nh = ipv6_hdr(skb);
471
472 /* Setting an IP addresses is typically only a side effect of
473 * matching on them in the current userspace implementation, so it
474 * makes sense to check if the value actually changed.
475 */
476 if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
477 __be32 *saddr = (__be32 *)&nh->saddr;
478 __be32 masked[4];
479
480 mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
481
482 if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
483 set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
484 true);
485 memcpy(&flow_key->ipv6.addr.src, masked,
486 sizeof(flow_key->ipv6.addr.src));
487 }
488 }
489 if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
490 unsigned int offset = 0;
491 int flags = IP6_FH_F_SKIP_RH;
492 bool recalc_csum = true;
493 __be32 *daddr = (__be32 *)&nh->daddr;
494 __be32 masked[4];
495
496 mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
497
498 if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
499 if (ipv6_ext_hdr(nh->nexthdr))
500 recalc_csum = (ipv6_find_hdr(skb, &offset,
501 NEXTHDR_ROUTING,
502 NULL, &flags)
503 != NEXTHDR_ROUTING);
504
505 set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
506 recalc_csum);
507 memcpy(&flow_key->ipv6.addr.dst, masked,
508 sizeof(flow_key->ipv6.addr.dst));
509 }
510 }
511 if (mask->ipv6_tclass) {
512 ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
513 flow_key->ip.tos = ipv6_get_dsfield(nh);
514 }
515 if (mask->ipv6_label) {
516 set_ipv6_fl(nh, ntohl(key->ipv6_label),
517 ntohl(mask->ipv6_label));
518 flow_key->ipv6.label =
519 *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
520 }
521 if (mask->ipv6_hlimit) {
522 OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit,
523 mask->ipv6_hlimit);
524 flow_key->ip.ttl = nh->hop_limit;
525 }
526 return 0;
527 }
528
529 /* Must follow skb_ensure_writable() since that can move the skb data. */
530 static void set_tp_port(struct sk_buff *skb, __be16 *port,
531 __be16 new_port, __sum16 *check)
532 {
533 inet_proto_csum_replace2(check, skb, *port, new_port, false);
534 *port = new_port;
535 }
536
537 static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
538 const struct ovs_key_udp *key,
539 const struct ovs_key_udp *mask)
540 {
541 struct udphdr *uh;
542 __be16 src, dst;
543 int err;
544
545 err = skb_ensure_writable(skb, skb_transport_offset(skb) +
546 sizeof(struct udphdr));
547 if (unlikely(err))
548 return err;
549
550 uh = udp_hdr(skb);
551 /* Either of the masks is non-zero, so do not bother checking them. */
552 src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src);
553 dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst);
554
555 if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
556 if (likely(src != uh->source)) {
557 set_tp_port(skb, &uh->source, src, &uh->check);
558 flow_key->tp.src = src;
559 }
560 if (likely(dst != uh->dest)) {
561 set_tp_port(skb, &uh->dest, dst, &uh->check);
562 flow_key->tp.dst = dst;
563 }
564
565 if (unlikely(!uh->check))
566 uh->check = CSUM_MANGLED_0;
567 } else {
568 uh->source = src;
569 uh->dest = dst;
570 flow_key->tp.src = src;
571 flow_key->tp.dst = dst;
572 }
573
574 skb_clear_hash(skb);
575
576 return 0;
577 }
578
579 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
580 const struct ovs_key_tcp *key,
581 const struct ovs_key_tcp *mask)
582 {
583 struct tcphdr *th;
584 __be16 src, dst;
585 int err;
586
587 err = skb_ensure_writable(skb, skb_transport_offset(skb) +
588 sizeof(struct tcphdr));
589 if (unlikely(err))
590 return err;
591
592 th = tcp_hdr(skb);
593 src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src);
594 if (likely(src != th->source)) {
595 set_tp_port(skb, &th->source, src, &th->check);
596 flow_key->tp.src = src;
597 }
598 dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
599 if (likely(dst != th->dest)) {
600 set_tp_port(skb, &th->dest, dst, &th->check);
601 flow_key->tp.dst = dst;
602 }
603 skb_clear_hash(skb);
604
605 return 0;
606 }
607
608 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
609 const struct ovs_key_sctp *key,
610 const struct ovs_key_sctp *mask)
611 {
612 unsigned int sctphoff = skb_transport_offset(skb);
613 struct sctphdr *sh;
614 __le32 old_correct_csum, new_csum, old_csum;
615 int err;
616
617 err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
618 if (unlikely(err))
619 return err;
620
621 sh = sctp_hdr(skb);
622 old_csum = sh->checksum;
623 old_correct_csum = sctp_compute_cksum(skb, sctphoff);
624
625 sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src);
626 sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
627
628 new_csum = sctp_compute_cksum(skb, sctphoff);
629
630 /* Carry any checksum errors through. */
631 sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
632
633 skb_clear_hash(skb);
634 flow_key->tp.src = sh->source;
635 flow_key->tp.dst = sh->dest;
636
637 return 0;
638 }
639
640 static int ovs_vport_output(struct net *net, struct sock *sk, struct sk_buff *skb)
641 {
642 struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
643 struct vport *vport = data->vport;
644
645 if (skb_cow_head(skb, data->l2_len) < 0) {
646 kfree_skb(skb);
647 return -ENOMEM;
648 }
649
650 __skb_dst_copy(skb, data->dst);
651 *OVS_CB(skb) = data->cb;
652 skb->inner_protocol = data->inner_protocol;
653 skb->vlan_tci = data->vlan_tci;
654 skb->vlan_proto = data->vlan_proto;
655
656 /* Reconstruct the MAC header. */
657 skb_push(skb, data->l2_len);
658 memcpy(skb->data, &data->l2_data, data->l2_len);
659 skb_postpush_rcsum(skb, skb->data, data->l2_len);
660 skb_reset_mac_header(skb);
661
662 ovs_vport_send(vport, skb);
663 return 0;
664 }
665
666 static unsigned int
667 ovs_dst_get_mtu(const struct dst_entry *dst)
668 {
669 return dst->dev->mtu;
670 }
671
672 static struct dst_ops ovs_dst_ops = {
673 .family = AF_UNSPEC,
674 .mtu = ovs_dst_get_mtu,
675 };
676
677 /* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
678 * ovs_vport_output(), which is called once per fragmented packet.
679 */
680 static void prepare_frag(struct vport *vport, struct sk_buff *skb)
681 {
682 unsigned int hlen = skb_network_offset(skb);
683 struct ovs_frag_data *data;
684
685 data = this_cpu_ptr(&ovs_frag_data_storage);
686 data->dst = skb->_skb_refdst;
687 data->vport = vport;
688 data->cb = *OVS_CB(skb);
689 data->inner_protocol = skb->inner_protocol;
690 data->vlan_tci = skb->vlan_tci;
691 data->vlan_proto = skb->vlan_proto;
692 data->l2_len = hlen;
693 memcpy(&data->l2_data, skb->data, hlen);
694
695 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
696 skb_pull(skb, hlen);
697 }
698
699 static void ovs_fragment(struct net *net, struct vport *vport,
700 struct sk_buff *skb, u16 mru, __be16 ethertype)
701 {
702 if (skb_network_offset(skb) > MAX_L2_LEN) {
703 OVS_NLERR(1, "L2 header too long to fragment");
704 goto err;
705 }
706
707 if (ethertype == htons(ETH_P_IP)) {
708 struct dst_entry ovs_dst;
709 unsigned long orig_dst;
710
711 prepare_frag(vport, skb);
712 dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
713 DST_OBSOLETE_NONE, DST_NOCOUNT);
714 ovs_dst.dev = vport->dev;
715
716 orig_dst = skb->_skb_refdst;
717 skb_dst_set_noref(skb, &ovs_dst);
718 IPCB(skb)->frag_max_size = mru;
719
720 ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
721 refdst_drop(orig_dst);
722 } else if (ethertype == htons(ETH_P_IPV6)) {
723 const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
724 unsigned long orig_dst;
725 struct rt6_info ovs_rt;
726
727 if (!v6ops) {
728 goto err;
729 }
730
731 prepare_frag(vport, skb);
732 memset(&ovs_rt, 0, sizeof(ovs_rt));
733 dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
734 DST_OBSOLETE_NONE, DST_NOCOUNT);
735 ovs_rt.dst.dev = vport->dev;
736
737 orig_dst = skb->_skb_refdst;
738 skb_dst_set_noref(skb, &ovs_rt.dst);
739 IP6CB(skb)->frag_max_size = mru;
740
741 v6ops->fragment(net, skb->sk, skb, ovs_vport_output);
742 refdst_drop(orig_dst);
743 } else {
744 WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
745 ovs_vport_name(vport), ntohs(ethertype), mru,
746 vport->dev->mtu);
747 goto err;
748 }
749
750 return;
751 err:
752 kfree_skb(skb);
753 }
754
755 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
756 struct sw_flow_key *key)
757 {
758 struct vport *vport = ovs_vport_rcu(dp, out_port);
759
760 if (likely(vport)) {
761 u16 mru = OVS_CB(skb)->mru;
762 u32 cutlen = OVS_CB(skb)->cutlen;
763
764 if (unlikely(cutlen > 0)) {
765 if (skb->len - cutlen > ETH_HLEN)
766 pskb_trim(skb, skb->len - cutlen);
767 else
768 pskb_trim(skb, ETH_HLEN);
769 }
770
771 if (likely(!mru || (skb->len <= mru + ETH_HLEN))) {
772 ovs_vport_send(vport, skb);
773 } else if (mru <= vport->dev->mtu) {
774 struct net *net = read_pnet(&dp->net);
775 __be16 ethertype = key->eth.type;
776
777 if (!is_flow_key_valid(key)) {
778 if (eth_p_mpls(skb->protocol))
779 ethertype = skb->inner_protocol;
780 else
781 ethertype = vlan_get_protocol(skb);
782 }
783
784 ovs_fragment(net, vport, skb, mru, ethertype);
785 } else {
786 kfree_skb(skb);
787 }
788 } else {
789 kfree_skb(skb);
790 }
791 }
792
793 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
794 struct sw_flow_key *key, const struct nlattr *attr,
795 const struct nlattr *actions, int actions_len,
796 uint32_t cutlen)
797 {
798 struct dp_upcall_info upcall;
799 const struct nlattr *a;
800 int rem;
801
802 memset(&upcall, 0, sizeof(upcall));
803 upcall.cmd = OVS_PACKET_CMD_ACTION;
804 upcall.mru = OVS_CB(skb)->mru;
805
806 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
807 a = nla_next(a, &rem)) {
808 switch (nla_type(a)) {
809 case OVS_USERSPACE_ATTR_USERDATA:
810 upcall.userdata = a;
811 break;
812
813 case OVS_USERSPACE_ATTR_PID:
814 upcall.portid = nla_get_u32(a);
815 break;
816
817 case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
818 /* Get out tunnel info. */
819 struct vport *vport;
820
821 vport = ovs_vport_rcu(dp, nla_get_u32(a));
822 if (vport) {
823 int err;
824
825 err = dev_fill_metadata_dst(vport->dev, skb);
826 if (!err)
827 upcall.egress_tun_info = skb_tunnel_info(skb);
828 }
829
830 break;
831 }
832
833 case OVS_USERSPACE_ATTR_ACTIONS: {
834 /* Include actions. */
835 upcall.actions = actions;
836 upcall.actions_len = actions_len;
837 break;
838 }
839
840 } /* End of switch. */
841 }
842
843 return ovs_dp_upcall(dp, skb, key, &upcall, cutlen);
844 }
845
846 static int sample(struct datapath *dp, struct sk_buff *skb,
847 struct sw_flow_key *key, const struct nlattr *attr,
848 const struct nlattr *actions, int actions_len)
849 {
850 const struct nlattr *acts_list = NULL;
851 const struct nlattr *a;
852 int rem;
853 u32 cutlen = 0;
854
855 for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
856 a = nla_next(a, &rem)) {
857 u32 probability;
858
859 switch (nla_type(a)) {
860 case OVS_SAMPLE_ATTR_PROBABILITY:
861 probability = nla_get_u32(a);
862 if (!probability || prandom_u32() > probability)
863 return 0;
864 break;
865
866 case OVS_SAMPLE_ATTR_ACTIONS:
867 acts_list = a;
868 break;
869 }
870 }
871
872 rem = nla_len(acts_list);
873 a = nla_data(acts_list);
874
875 /* Actions list is empty, do nothing */
876 if (unlikely(!rem))
877 return 0;
878
879 /* The only known usage of sample action is having a single user-space
880 * action, or having a truncate action followed by a single user-space
881 * action. Treat this usage as a special case.
882 * The output_userspace() should clone the skb to be sent to the
883 * user space. This skb will be consumed by its caller.
884 */
885 if (unlikely(nla_type(a) == OVS_ACTION_ATTR_TRUNC)) {
886 struct ovs_action_trunc *trunc = nla_data(a);
887
888 if (skb->len > trunc->max_len)
889 cutlen = skb->len - trunc->max_len;
890
891 a = nla_next(a, &rem);
892 }
893
894 if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
895 nla_is_last(a, rem)))
896 return output_userspace(dp, skb, key, a, actions,
897 actions_len, cutlen);
898
899 skb = skb_clone(skb, GFP_ATOMIC);
900 if (!skb)
901 /* Skip the sample action when out of memory. */
902 return 0;
903
904 if (!add_deferred_actions(skb, key, a)) {
905 if (net_ratelimit())
906 pr_warn("%s: deferred actions limit reached, dropping sample action\n",
907 ovs_dp_name(dp));
908
909 kfree_skb(skb);
910 }
911 return 0;
912 }
913
914 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
915 const struct nlattr *attr)
916 {
917 struct ovs_action_hash *hash_act = nla_data(attr);
918 u32 hash = 0;
919
920 /* OVS_HASH_ALG_L4 is the only possible hash algorithm. */
921 hash = skb_get_hash(skb);
922 hash = jhash_1word(hash, hash_act->hash_basis);
923 if (!hash)
924 hash = 0x1;
925
926 key->ovs_flow_hash = hash;
927 }
928
929 static int execute_set_action(struct sk_buff *skb,
930 struct sw_flow_key *flow_key,
931 const struct nlattr *a)
932 {
933 /* Only tunnel set execution is supported without a mask. */
934 if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
935 struct ovs_tunnel_info *tun = nla_data(a);
936
937 skb_dst_drop(skb);
938 dst_hold((struct dst_entry *)tun->tun_dst);
939 skb_dst_set(skb, (struct dst_entry *)tun->tun_dst);
940 return 0;
941 }
942
943 return -EINVAL;
944 }
945
946 /* Mask is at the midpoint of the data. */
947 #define get_mask(a, type) ((const type)nla_data(a) + 1)
948
949 static int execute_masked_set_action(struct sk_buff *skb,
950 struct sw_flow_key *flow_key,
951 const struct nlattr *a)
952 {
953 int err = 0;
954
955 switch (nla_type(a)) {
956 case OVS_KEY_ATTR_PRIORITY:
957 OVS_SET_MASKED(skb->priority, nla_get_u32(a),
958 *get_mask(a, u32 *));
959 flow_key->phy.priority = skb->priority;
960 break;
961
962 case OVS_KEY_ATTR_SKB_MARK:
963 OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
964 flow_key->phy.skb_mark = skb->mark;
965 break;
966
967 case OVS_KEY_ATTR_TUNNEL_INFO:
968 /* Masked data not supported for tunnel. */
969 err = -EINVAL;
970 break;
971
972 case OVS_KEY_ATTR_ETHERNET:
973 err = set_eth_addr(skb, flow_key, nla_data(a),
974 get_mask(a, struct ovs_key_ethernet *));
975 break;
976
977 case OVS_KEY_ATTR_IPV4:
978 err = set_ipv4(skb, flow_key, nla_data(a),
979 get_mask(a, struct ovs_key_ipv4 *));
980 break;
981
982 case OVS_KEY_ATTR_IPV6:
983 err = set_ipv6(skb, flow_key, nla_data(a),
984 get_mask(a, struct ovs_key_ipv6 *));
985 break;
986
987 case OVS_KEY_ATTR_TCP:
988 err = set_tcp(skb, flow_key, nla_data(a),
989 get_mask(a, struct ovs_key_tcp *));
990 break;
991
992 case OVS_KEY_ATTR_UDP:
993 err = set_udp(skb, flow_key, nla_data(a),
994 get_mask(a, struct ovs_key_udp *));
995 break;
996
997 case OVS_KEY_ATTR_SCTP:
998 err = set_sctp(skb, flow_key, nla_data(a),
999 get_mask(a, struct ovs_key_sctp *));
1000 break;
1001
1002 case OVS_KEY_ATTR_MPLS:
1003 err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
1004 __be32 *));
1005 break;
1006
1007 case OVS_KEY_ATTR_CT_STATE:
1008 case OVS_KEY_ATTR_CT_ZONE:
1009 case OVS_KEY_ATTR_CT_MARK:
1010 case OVS_KEY_ATTR_CT_LABELS:
1011 err = -EINVAL;
1012 break;
1013 }
1014
1015 return err;
1016 }
1017
1018 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
1019 struct sw_flow_key *key,
1020 const struct nlattr *a, int rem)
1021 {
1022 struct deferred_action *da;
1023
1024 if (!is_flow_key_valid(key)) {
1025 int err;
1026
1027 err = ovs_flow_key_update(skb, key);
1028 if (err)
1029 return err;
1030 }
1031 BUG_ON(!is_flow_key_valid(key));
1032
1033 if (!nla_is_last(a, rem)) {
1034 /* Recirc action is the not the last action
1035 * of the action list, need to clone the skb.
1036 */
1037 skb = skb_clone(skb, GFP_ATOMIC);
1038
1039 /* Skip the recirc action when out of memory, but
1040 * continue on with the rest of the action list.
1041 */
1042 if (!skb)
1043 return 0;
1044 }
1045
1046 da = add_deferred_actions(skb, key, NULL);
1047 if (da) {
1048 da->pkt_key.recirc_id = nla_get_u32(a);
1049 } else {
1050 kfree_skb(skb);
1051
1052 if (net_ratelimit())
1053 pr_warn("%s: deferred action limit reached, drop recirc action\n",
1054 ovs_dp_name(dp));
1055 }
1056
1057 return 0;
1058 }
1059
1060 /* Execute a list of actions against 'skb'. */
1061 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
1062 struct sw_flow_key *key,
1063 const struct nlattr *attr, int len)
1064 {
1065 /* Every output action needs a separate clone of 'skb', but the common
1066 * case is just a single output action, so that doing a clone and
1067 * then freeing the original skbuff is wasteful. So the following code
1068 * is slightly obscure just to avoid that.
1069 */
1070 int prev_port = -1;
1071 const struct nlattr *a;
1072 int rem;
1073
1074 for (a = attr, rem = len; rem > 0;
1075 a = nla_next(a, &rem)) {
1076 int err = 0;
1077
1078 if (unlikely(prev_port != -1)) {
1079 struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
1080
1081 if (out_skb)
1082 do_output(dp, out_skb, prev_port, key);
1083
1084 OVS_CB(skb)->cutlen = 0;
1085 prev_port = -1;
1086 }
1087
1088 switch (nla_type(a)) {
1089 case OVS_ACTION_ATTR_OUTPUT:
1090 prev_port = nla_get_u32(a);
1091 break;
1092
1093 case OVS_ACTION_ATTR_TRUNC: {
1094 struct ovs_action_trunc *trunc = nla_data(a);
1095
1096 if (skb->len > trunc->max_len)
1097 OVS_CB(skb)->cutlen = skb->len - trunc->max_len;
1098 break;
1099 }
1100
1101 case OVS_ACTION_ATTR_USERSPACE:
1102 output_userspace(dp, skb, key, a, attr,
1103 len, OVS_CB(skb)->cutlen);
1104 OVS_CB(skb)->cutlen = 0;
1105 break;
1106
1107 case OVS_ACTION_ATTR_HASH:
1108 execute_hash(skb, key, a);
1109 break;
1110
1111 case OVS_ACTION_ATTR_PUSH_MPLS:
1112 err = push_mpls(skb, key, nla_data(a));
1113 break;
1114
1115 case OVS_ACTION_ATTR_POP_MPLS:
1116 err = pop_mpls(skb, key, nla_get_be16(a));
1117 break;
1118
1119 case OVS_ACTION_ATTR_PUSH_VLAN:
1120 err = push_vlan(skb, key, nla_data(a));
1121 break;
1122
1123 case OVS_ACTION_ATTR_POP_VLAN:
1124 err = pop_vlan(skb, key);
1125 break;
1126
1127 case OVS_ACTION_ATTR_RECIRC:
1128 err = execute_recirc(dp, skb, key, a, rem);
1129 if (nla_is_last(a, rem)) {
1130 /* If this is the last action, the skb has
1131 * been consumed or freed.
1132 * Return immediately.
1133 */
1134 return err;
1135 }
1136 break;
1137
1138 case OVS_ACTION_ATTR_SET:
1139 err = execute_set_action(skb, key, nla_data(a));
1140 break;
1141
1142 case OVS_ACTION_ATTR_SET_MASKED:
1143 case OVS_ACTION_ATTR_SET_TO_MASKED:
1144 err = execute_masked_set_action(skb, key, nla_data(a));
1145 break;
1146
1147 case OVS_ACTION_ATTR_SAMPLE:
1148 err = sample(dp, skb, key, a, attr, len);
1149 break;
1150
1151 case OVS_ACTION_ATTR_CT:
1152 if (!is_flow_key_valid(key)) {
1153 err = ovs_flow_key_update(skb, key);
1154 if (err)
1155 return err;
1156 }
1157
1158 err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
1159 nla_data(a));
1160
1161 /* Hide stolen IP fragments from user space. */
1162 if (err)
1163 return err == -EINPROGRESS ? 0 : err;
1164 break;
1165 }
1166
1167 if (unlikely(err)) {
1168 kfree_skb(skb);
1169 return err;
1170 }
1171 }
1172
1173 if (prev_port != -1)
1174 do_output(dp, skb, prev_port, key);
1175 else
1176 consume_skb(skb);
1177
1178 return 0;
1179 }
1180
1181 static void process_deferred_actions(struct datapath *dp)
1182 {
1183 struct action_fifo *fifo = this_cpu_ptr(action_fifos);
1184
1185 /* Do not touch the FIFO in case there is no deferred actions. */
1186 if (action_fifo_is_empty(fifo))
1187 return;
1188
1189 /* Finishing executing all deferred actions. */
1190 do {
1191 struct deferred_action *da = action_fifo_get(fifo);
1192 struct sk_buff *skb = da->skb;
1193 struct sw_flow_key *key = &da->pkt_key;
1194 const struct nlattr *actions = da->actions;
1195
1196 if (actions)
1197 do_execute_actions(dp, skb, key, actions,
1198 nla_len(actions));
1199 else
1200 ovs_dp_process_packet(skb, key);
1201 } while (!action_fifo_is_empty(fifo));
1202
1203 /* Reset FIFO for the next packet. */
1204 action_fifo_init(fifo);
1205 }
1206
1207 /* Execute a list of actions against 'skb'. */
1208 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
1209 const struct sw_flow_actions *acts,
1210 struct sw_flow_key *key)
1211 {
1212 static const int ovs_recursion_limit = 5;
1213 int err, level;
1214
1215 level = __this_cpu_inc_return(exec_actions_level);
1216 if (unlikely(level > ovs_recursion_limit)) {
1217 net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n",
1218 ovs_dp_name(dp));
1219 kfree_skb(skb);
1220 err = -ENETDOWN;
1221 goto out;
1222 }
1223
1224 err = do_execute_actions(dp, skb, key,
1225 acts->actions, acts->actions_len);
1226
1227 if (level == 1)
1228 process_deferred_actions(dp);
1229
1230 out:
1231 __this_cpu_dec(exec_actions_level);
1232 return err;
1233 }
1234
1235 int action_fifos_init(void)
1236 {
1237 action_fifos = alloc_percpu(struct action_fifo);
1238 if (!action_fifos)
1239 return -ENOMEM;
1240
1241 return 0;
1242 }
1243
1244 void action_fifos_exit(void)
1245 {
1246 free_percpu(action_fifos);
1247 }
Linux kernel - Deliverables
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