Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
[firefly-linux-kernel-4.4.55.git] / net / openvswitch / actions.c
1 /*
2  * Copyright (c) 2007-2012 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/tcp.h>
26 #include <linux/udp.h>
27 #include <linux/in6.h>
28 #include <linux/if_arp.h>
29 #include <linux/if_vlan.h>
30 #include <net/ip.h>
31 #include <net/ipv6.h>
32 #include <net/checksum.h>
33 #include <net/dsfield.h>
34
35 #include "datapath.h"
36 #include "vport.h"
37
38 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
39                         const struct nlattr *attr, int len, bool keep_skb);
40
41 static int make_writable(struct sk_buff *skb, int write_len)
42 {
43         if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
44                 return 0;
45
46         return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
47 }
48
49 /* remove VLAN header from packet and update csum accordingly. */
50 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
51 {
52         struct vlan_hdr *vhdr;
53         int err;
54
55         err = make_writable(skb, VLAN_ETH_HLEN);
56         if (unlikely(err))
57                 return err;
58
59         if (skb->ip_summed == CHECKSUM_COMPLETE)
60                 skb->csum = csum_sub(skb->csum, csum_partial(skb->data
61                                         + (2 * ETH_ALEN), VLAN_HLEN, 0));
62
63         vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
64         *current_tci = vhdr->h_vlan_TCI;
65
66         memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
67         __skb_pull(skb, VLAN_HLEN);
68
69         vlan_set_encap_proto(skb, vhdr);
70         skb->mac_header += VLAN_HLEN;
71         skb_reset_mac_len(skb);
72
73         return 0;
74 }
75
76 static int pop_vlan(struct sk_buff *skb)
77 {
78         __be16 tci;
79         int err;
80
81         if (likely(vlan_tx_tag_present(skb))) {
82                 skb->vlan_tci = 0;
83         } else {
84                 if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
85                              skb->len < VLAN_ETH_HLEN))
86                         return 0;
87
88                 err = __pop_vlan_tci(skb, &tci);
89                 if (err)
90                         return err;
91         }
92         /* move next vlan tag to hw accel tag */
93         if (likely(skb->protocol != htons(ETH_P_8021Q) ||
94                    skb->len < VLAN_ETH_HLEN))
95                 return 0;
96
97         err = __pop_vlan_tci(skb, &tci);
98         if (unlikely(err))
99                 return err;
100
101         __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
102         return 0;
103 }
104
105 static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan)
106 {
107         if (unlikely(vlan_tx_tag_present(skb))) {
108                 u16 current_tag;
109
110                 /* push down current VLAN tag */
111                 current_tag = vlan_tx_tag_get(skb);
112
113                 if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag))
114                         return -ENOMEM;
115
116                 if (skb->ip_summed == CHECKSUM_COMPLETE)
117                         skb->csum = csum_add(skb->csum, csum_partial(skb->data
118                                         + (2 * ETH_ALEN), VLAN_HLEN, 0));
119
120         }
121         __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
122         return 0;
123 }
124
125 static int set_eth_addr(struct sk_buff *skb,
126                         const struct ovs_key_ethernet *eth_key)
127 {
128         int err;
129         err = make_writable(skb, ETH_HLEN);
130         if (unlikely(err))
131                 return err;
132
133         memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);
134         memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN);
135
136         return 0;
137 }
138
139 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
140                                 __be32 *addr, __be32 new_addr)
141 {
142         int transport_len = skb->len - skb_transport_offset(skb);
143
144         if (nh->protocol == IPPROTO_TCP) {
145                 if (likely(transport_len >= sizeof(struct tcphdr)))
146                         inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
147                                                  *addr, new_addr, 1);
148         } else if (nh->protocol == IPPROTO_UDP) {
149                 if (likely(transport_len >= sizeof(struct udphdr))) {
150                         struct udphdr *uh = udp_hdr(skb);
151
152                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
153                                 inet_proto_csum_replace4(&uh->check, skb,
154                                                          *addr, new_addr, 1);
155                                 if (!uh->check)
156                                         uh->check = CSUM_MANGLED_0;
157                         }
158                 }
159         }
160
161         csum_replace4(&nh->check, *addr, new_addr);
162         skb->rxhash = 0;
163         *addr = new_addr;
164 }
165
166 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
167                                  __be32 addr[4], const __be32 new_addr[4])
168 {
169         int transport_len = skb->len - skb_transport_offset(skb);
170
171         if (l4_proto == IPPROTO_TCP) {
172                 if (likely(transport_len >= sizeof(struct tcphdr)))
173                         inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
174                                                   addr, new_addr, 1);
175         } else if (l4_proto == IPPROTO_UDP) {
176                 if (likely(transport_len >= sizeof(struct udphdr))) {
177                         struct udphdr *uh = udp_hdr(skb);
178
179                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
180                                 inet_proto_csum_replace16(&uh->check, skb,
181                                                           addr, new_addr, 1);
182                                 if (!uh->check)
183                                         uh->check = CSUM_MANGLED_0;
184                         }
185                 }
186         }
187 }
188
189 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
190                           __be32 addr[4], const __be32 new_addr[4],
191                           bool recalculate_csum)
192 {
193         if (recalculate_csum)
194                 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
195
196         skb->rxhash = 0;
197         memcpy(addr, new_addr, sizeof(__be32[4]));
198 }
199
200 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
201 {
202         nh->priority = tc >> 4;
203         nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
204 }
205
206 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
207 {
208         nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
209         nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
210         nh->flow_lbl[2] = fl & 0x000000FF;
211 }
212
213 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
214 {
215         csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
216         nh->ttl = new_ttl;
217 }
218
219 static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
220 {
221         struct iphdr *nh;
222         int err;
223
224         err = make_writable(skb, skb_network_offset(skb) +
225                                  sizeof(struct iphdr));
226         if (unlikely(err))
227                 return err;
228
229         nh = ip_hdr(skb);
230
231         if (ipv4_key->ipv4_src != nh->saddr)
232                 set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
233
234         if (ipv4_key->ipv4_dst != nh->daddr)
235                 set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
236
237         if (ipv4_key->ipv4_tos != nh->tos)
238                 ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
239
240         if (ipv4_key->ipv4_ttl != nh->ttl)
241                 set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
242
243         return 0;
244 }
245
246 static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
247 {
248         struct ipv6hdr *nh;
249         int err;
250         __be32 *saddr;
251         __be32 *daddr;
252
253         err = make_writable(skb, skb_network_offset(skb) +
254                             sizeof(struct ipv6hdr));
255         if (unlikely(err))
256                 return err;
257
258         nh = ipv6_hdr(skb);
259         saddr = (__be32 *)&nh->saddr;
260         daddr = (__be32 *)&nh->daddr;
261
262         if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src)))
263                 set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
264                               ipv6_key->ipv6_src, true);
265
266         if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
267                 unsigned int offset = 0;
268                 int flags = IP6_FH_F_SKIP_RH;
269                 bool recalc_csum = true;
270
271                 if (ipv6_ext_hdr(nh->nexthdr))
272                         recalc_csum = ipv6_find_hdr(skb, &offset,
273                                                     NEXTHDR_ROUTING, NULL,
274                                                     &flags) != NEXTHDR_ROUTING;
275
276                 set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
277                               ipv6_key->ipv6_dst, recalc_csum);
278         }
279
280         set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
281         set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
282         nh->hop_limit = ipv6_key->ipv6_hlimit;
283
284         return 0;
285 }
286
287 /* Must follow make_writable() since that can move the skb data. */
288 static void set_tp_port(struct sk_buff *skb, __be16 *port,
289                          __be16 new_port, __sum16 *check)
290 {
291         inet_proto_csum_replace2(check, skb, *port, new_port, 0);
292         *port = new_port;
293         skb->rxhash = 0;
294 }
295
296 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
297 {
298         struct udphdr *uh = udp_hdr(skb);
299
300         if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
301                 set_tp_port(skb, port, new_port, &uh->check);
302
303                 if (!uh->check)
304                         uh->check = CSUM_MANGLED_0;
305         } else {
306                 *port = new_port;
307                 skb->rxhash = 0;
308         }
309 }
310
311 static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
312 {
313         struct udphdr *uh;
314         int err;
315
316         err = make_writable(skb, skb_transport_offset(skb) +
317                                  sizeof(struct udphdr));
318         if (unlikely(err))
319                 return err;
320
321         uh = udp_hdr(skb);
322         if (udp_port_key->udp_src != uh->source)
323                 set_udp_port(skb, &uh->source, udp_port_key->udp_src);
324
325         if (udp_port_key->udp_dst != uh->dest)
326                 set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
327
328         return 0;
329 }
330
331 static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key)
332 {
333         struct tcphdr *th;
334         int err;
335
336         err = make_writable(skb, skb_transport_offset(skb) +
337                                  sizeof(struct tcphdr));
338         if (unlikely(err))
339                 return err;
340
341         th = tcp_hdr(skb);
342         if (tcp_port_key->tcp_src != th->source)
343                 set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
344
345         if (tcp_port_key->tcp_dst != th->dest)
346                 set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
347
348         return 0;
349 }
350
351 static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
352 {
353         struct vport *vport;
354
355         if (unlikely(!skb))
356                 return -ENOMEM;
357
358         vport = ovs_vport_rcu(dp, out_port);
359         if (unlikely(!vport)) {
360                 kfree_skb(skb);
361                 return -ENODEV;
362         }
363
364         ovs_vport_send(vport, skb);
365         return 0;
366 }
367
368 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
369                             const struct nlattr *attr)
370 {
371         struct dp_upcall_info upcall;
372         const struct nlattr *a;
373         int rem;
374
375         upcall.cmd = OVS_PACKET_CMD_ACTION;
376         upcall.key = &OVS_CB(skb)->flow->key;
377         upcall.userdata = NULL;
378         upcall.portid = 0;
379
380         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
381                  a = nla_next(a, &rem)) {
382                 switch (nla_type(a)) {
383                 case OVS_USERSPACE_ATTR_USERDATA:
384                         upcall.userdata = a;
385                         break;
386
387                 case OVS_USERSPACE_ATTR_PID:
388                         upcall.portid = nla_get_u32(a);
389                         break;
390                 }
391         }
392
393         return ovs_dp_upcall(dp, skb, &upcall);
394 }
395
396 static int sample(struct datapath *dp, struct sk_buff *skb,
397                   const struct nlattr *attr)
398 {
399         const struct nlattr *acts_list = NULL;
400         const struct nlattr *a;
401         int rem;
402
403         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
404                  a = nla_next(a, &rem)) {
405                 switch (nla_type(a)) {
406                 case OVS_SAMPLE_ATTR_PROBABILITY:
407                         if (net_random() >= nla_get_u32(a))
408                                 return 0;
409                         break;
410
411                 case OVS_SAMPLE_ATTR_ACTIONS:
412                         acts_list = a;
413                         break;
414                 }
415         }
416
417         return do_execute_actions(dp, skb, nla_data(acts_list),
418                                                  nla_len(acts_list), true);
419 }
420
421 static int execute_set_action(struct sk_buff *skb,
422                                  const struct nlattr *nested_attr)
423 {
424         int err = 0;
425
426         switch (nla_type(nested_attr)) {
427         case OVS_KEY_ATTR_PRIORITY:
428                 skb->priority = nla_get_u32(nested_attr);
429                 break;
430
431         case OVS_KEY_ATTR_SKB_MARK:
432                 skb->mark = nla_get_u32(nested_attr);
433                 break;
434
435         case OVS_KEY_ATTR_ETHERNET:
436                 err = set_eth_addr(skb, nla_data(nested_attr));
437                 break;
438
439         case OVS_KEY_ATTR_IPV4:
440                 err = set_ipv4(skb, nla_data(nested_attr));
441                 break;
442
443         case OVS_KEY_ATTR_IPV6:
444                 err = set_ipv6(skb, nla_data(nested_attr));
445                 break;
446
447         case OVS_KEY_ATTR_TCP:
448                 err = set_tcp(skb, nla_data(nested_attr));
449                 break;
450
451         case OVS_KEY_ATTR_UDP:
452                 err = set_udp(skb, nla_data(nested_attr));
453                 break;
454         }
455
456         return err;
457 }
458
459 /* Execute a list of actions against 'skb'. */
460 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
461                         const struct nlattr *attr, int len, bool keep_skb)
462 {
463         /* Every output action needs a separate clone of 'skb', but the common
464          * case is just a single output action, so that doing a clone and
465          * then freeing the original skbuff is wasteful.  So the following code
466          * is slightly obscure just to avoid that. */
467         int prev_port = -1;
468         const struct nlattr *a;
469         int rem;
470
471         for (a = attr, rem = len; rem > 0;
472              a = nla_next(a, &rem)) {
473                 int err = 0;
474
475                 if (prev_port != -1) {
476                         do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
477                         prev_port = -1;
478                 }
479
480                 switch (nla_type(a)) {
481                 case OVS_ACTION_ATTR_OUTPUT:
482                         prev_port = nla_get_u32(a);
483                         break;
484
485                 case OVS_ACTION_ATTR_USERSPACE:
486                         output_userspace(dp, skb, a);
487                         break;
488
489                 case OVS_ACTION_ATTR_PUSH_VLAN:
490                         err = push_vlan(skb, nla_data(a));
491                         if (unlikely(err)) /* skb already freed. */
492                                 return err;
493                         break;
494
495                 case OVS_ACTION_ATTR_POP_VLAN:
496                         err = pop_vlan(skb);
497                         break;
498
499                 case OVS_ACTION_ATTR_SET:
500                         err = execute_set_action(skb, nla_data(a));
501                         break;
502
503                 case OVS_ACTION_ATTR_SAMPLE:
504                         err = sample(dp, skb, a);
505                         break;
506                 }
507
508                 if (unlikely(err)) {
509                         kfree_skb(skb);
510                         return err;
511                 }
512         }
513
514         if (prev_port != -1) {
515                 if (keep_skb)
516                         skb = skb_clone(skb, GFP_ATOMIC);
517
518                 do_output(dp, skb, prev_port);
519         } else if (!keep_skb)
520                 consume_skb(skb);
521
522         return 0;
523 }
524
525 /* Execute a list of actions against 'skb'. */
526 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb)
527 {
528         struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
529
530         return do_execute_actions(dp, skb, acts->actions,
531                                          acts->actions_len, false);
532 }