datapath: Use __read_mostly annotations where appropriate.
[openvswitch] / datapath / tunnel.c
1 /*
2  * Copyright (c) 2010 Nicira Networks.
3  * Distributed under the terms of the GNU GPL version 2.
4  *
5  * Significant portions of this file may be copied from parts of the Linux
6  * kernel, by Linus Torvalds and others.
7  */
8
9 #include <linux/if_arp.h>
10 #include <linux/if_ether.h>
11 #include <linux/ip.h>
12 #include <linux/if_vlan.h>
13 #include <linux/in.h>
14 #include <linux/in_route.h>
15 #include <linux/jhash.h>
16 #include <linux/kernel.h>
17 #include <linux/version.h>
18 #include <linux/workqueue.h>
19
20 #include <net/dsfield.h>
21 #include <net/dst.h>
22 #include <net/icmp.h>
23 #include <net/inet_ecn.h>
24 #include <net/ip.h>
25 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
26 #include <net/ipv6.h>
27 #endif
28 #include <net/route.h>
29 #include <net/xfrm.h>
30
31 #include "actions.h"
32 #include "datapath.h"
33 #include "table.h"
34 #include "tunnel.h"
35 #include "vport.h"
36 #include "vport-generic.h"
37 #include "vport-internal_dev.h"
38
39 #ifdef NEED_CACHE_TIMEOUT
40 /*
41  * On kernels where we can't quickly detect changes in the rest of the system
42  * we use an expiration time to invalidate the cache.  A shorter expiration
43  * reduces the length of time that we may potentially blackhole packets while
44  * a longer time increases performance by reducing the frequency that the
45  * cache needs to be rebuilt.  A variety of factors may cause the cache to be
46  * invalidated before the expiration time but this is the maximum.  The time
47  * is expressed in jiffies.
48  */
49 #define MAX_CACHE_EXP HZ
50 #endif
51
52 /*
53  * Interval to check for and remove caches that are no longer valid.  Caches
54  * are checked for validity before they are used for packet encapsulation and
55  * old caches are removed at that time.  However, if no packets are sent through
56  * the tunnel then the cache will never be destroyed.  Since it holds
57  * references to a number of system objects, the cache will continue to use
58  * system resources by not allowing those objects to be destroyed.  The cache
59  * cleaner is periodically run to free invalid caches.  It does not
60  * significantly affect system performance.  A lower interval will release
61  * resources faster but will itself consume resources by requiring more frequent
62  * checks.  A longer interval may result in messages being printed to the kernel
63  * message buffer about unreleased resources.  The interval is expressed in
64  * jiffies.
65  */
66 #define CACHE_CLEANER_INTERVAL (5 * HZ)
67
68 #define CACHE_DATA_ALIGN 16
69
70 /* Protected by RCU. */
71 static struct tbl *port_table __read_mostly;
72
73 static void cache_cleaner(struct work_struct *work);
74 DECLARE_DELAYED_WORK(cache_cleaner_wq, cache_cleaner);
75
76 /*
77  * These are just used as an optimization: they don't require any kind of
78  * synchronization because we could have just as easily read the value before
79  * the port change happened.
80  */
81 static unsigned int key_local_remote_ports __read_mostly;
82 static unsigned int key_remote_ports __read_mostly;
83 static unsigned int local_remote_ports __read_mostly;
84 static unsigned int remote_ports __read_mostly;
85
86 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
87 #define rt_dst(rt) (rt->dst)
88 #else
89 #define rt_dst(rt) (rt->u.dst)
90 #endif
91
92 static inline struct vport *tnl_vport_to_vport(const struct tnl_vport *tnl_vport)
93 {
94         return vport_from_priv(tnl_vport);
95 }
96
97 static inline struct tnl_vport *tnl_vport_table_cast(const struct tbl_node *node)
98 {
99         return container_of(node, struct tnl_vport, tbl_node);
100 }
101
102 static inline void schedule_cache_cleaner(void)
103 {
104         schedule_delayed_work(&cache_cleaner_wq, CACHE_CLEANER_INTERVAL);
105 }
106
107 static void free_cache(struct tnl_cache *cache)
108 {
109         if (!cache)
110                 return;
111
112         flow_put(cache->flow);
113         ip_rt_put(cache->rt);
114         kfree(cache);
115 }
116
117 static void free_config_rcu(struct rcu_head *rcu)
118 {
119         struct tnl_mutable_config *c = container_of(rcu, struct tnl_mutable_config, rcu);
120         kfree(c);
121 }
122
123 static void free_cache_rcu(struct rcu_head *rcu)
124 {
125         struct tnl_cache *c = container_of(rcu, struct tnl_cache, rcu);
126         free_cache(c);
127 }
128
129 static void assign_config_rcu(struct vport *vport,
130                               struct tnl_mutable_config *new_config)
131 {
132         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
133         struct tnl_mutable_config *old_config;
134
135         old_config = tnl_vport->mutable;
136         rcu_assign_pointer(tnl_vport->mutable, new_config);
137         call_rcu(&old_config->rcu, free_config_rcu);
138 }
139
140 static void assign_cache_rcu(struct vport *vport, struct tnl_cache *new_cache)
141 {
142         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
143         struct tnl_cache *old_cache;
144
145         old_cache = tnl_vport->cache;
146         rcu_assign_pointer(tnl_vport->cache, new_cache);
147
148         if (old_cache)
149                 call_rcu(&old_cache->rcu, free_cache_rcu);
150 }
151
152 static unsigned int *find_port_pool(const struct tnl_mutable_config *mutable)
153 {
154         if (mutable->port_config.flags & TNL_F_IN_KEY_MATCH) {
155                 if (mutable->port_config.saddr)
156                         return &local_remote_ports;
157                 else
158                         return &remote_ports;
159         } else {
160                 if (mutable->port_config.saddr)
161                         return &key_local_remote_ports;
162                 else
163                         return &key_remote_ports;
164         }
165 }
166
167 enum lookup_key {
168         LOOKUP_TUNNEL_TYPE      = 0,
169         LOOKUP_SADDR            = 1,
170         LOOKUP_DADDR            = 2,
171         LOOKUP_KEY              = 3,
172 };
173
174 struct port_lookup_key {
175         u32 vals[4];                    /* Contains enum lookup_key keys. */
176         const struct tnl_mutable_config *mutable;
177 };
178
179 /*
180  * Modifies 'target' to store the rcu_dereferenced pointer that was used to do
181  * the comparision.
182  */
183 static int port_cmp(const struct tbl_node *node, void *target)
184 {
185         const struct tnl_vport *tnl_vport = tnl_vport_table_cast(node);
186         struct port_lookup_key *lookup = target;
187
188         lookup->mutable = rcu_dereference(tnl_vport->mutable);
189
190         return (lookup->mutable->tunnel_type == lookup->vals[LOOKUP_TUNNEL_TYPE]) &&
191                lookup->mutable->port_config.daddr == lookup->vals[LOOKUP_DADDR] &&
192                lookup->mutable->port_config.in_key == lookup->vals[LOOKUP_KEY] &&
193                lookup->mutable->port_config.saddr == lookup->vals[LOOKUP_SADDR];
194 }
195
196 static u32 port_hash(struct port_lookup_key *lookup)
197 {
198         return jhash2(lookup->vals, ARRAY_SIZE(lookup->vals), 0);
199 }
200
201 static u32 mutable_hash(const struct tnl_mutable_config *mutable)
202 {
203         struct port_lookup_key lookup;
204
205         lookup.vals[LOOKUP_SADDR] = mutable->port_config.saddr;
206         lookup.vals[LOOKUP_DADDR] = mutable->port_config.daddr;
207         lookup.vals[LOOKUP_KEY] = mutable->port_config.in_key;
208         lookup.vals[LOOKUP_TUNNEL_TYPE] = mutable->tunnel_type;
209
210         return port_hash(&lookup);
211 }
212
213 static void check_table_empty(void)
214 {
215         if (tbl_count(port_table) == 0) {
216                 struct tbl *old_table = port_table;
217
218                 cancel_delayed_work_sync(&cache_cleaner_wq);
219                 rcu_assign_pointer(port_table, NULL);
220                 tbl_deferred_destroy(old_table, NULL);
221         }
222 }
223
224 static int add_port(struct vport *vport)
225 {
226         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
227         int err;
228
229         if (!port_table) {
230                 struct tbl *new_table;
231
232                 new_table = tbl_create(0);
233                 if (!new_table)
234                         return -ENOMEM;
235
236                 rcu_assign_pointer(port_table, new_table);
237                 schedule_cache_cleaner();
238
239         } else if (tbl_count(port_table) > tbl_n_buckets(port_table)) {
240                 struct tbl *old_table = port_table;
241                 struct tbl *new_table;
242
243                 new_table = tbl_expand(old_table);
244                 if (IS_ERR(new_table))
245                         return PTR_ERR(new_table);
246
247                 rcu_assign_pointer(port_table, new_table);
248                 tbl_deferred_destroy(old_table, NULL);
249         }
250
251         err = tbl_insert(port_table, &tnl_vport->tbl_node, mutable_hash(tnl_vport->mutable));
252         if (err) {
253                 check_table_empty();
254                 return err;
255         }
256
257         (*find_port_pool(tnl_vport->mutable))++;
258
259         return 0;
260 }
261
262 static int move_port(struct vport *vport, struct tnl_mutable_config *new_mutable)
263 {
264         int err;
265         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
266         u32 hash;
267
268         hash = mutable_hash(new_mutable);
269         if (hash == tnl_vport->tbl_node.hash)
270                 goto table_updated;
271
272         /*
273          * Ideally we should make this move atomic to avoid having gaps in
274          * finding tunnels or the possibility of failure.  However, if we do
275          * find a tunnel it will always be consistent.
276          */
277         err = tbl_remove(port_table, &tnl_vport->tbl_node);
278         if (err)
279                 return err;
280
281         err = tbl_insert(port_table, &tnl_vport->tbl_node, hash);
282         if (err) {
283                 check_table_empty();
284                 return err;
285         }
286
287 table_updated:
288         assign_config_rcu(vport, new_mutable);
289
290         return 0;
291 }
292
293 static int del_port(struct vport *vport)
294 {
295         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
296         int err;
297
298         err = tbl_remove(port_table, &tnl_vport->tbl_node);
299         if (err)
300                 return err;
301
302         check_table_empty();
303         (*find_port_pool(tnl_vport->mutable))--;
304
305         return 0;
306 }
307
308 struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be32 key,
309                             int tunnel_type,
310                             const struct tnl_mutable_config **mutable)
311 {
312         struct port_lookup_key lookup;
313         struct tbl *table = rcu_dereference(port_table);
314         struct tbl_node *tbl_node;
315
316         if (unlikely(!table))
317                 return NULL;
318
319         lookup.vals[LOOKUP_SADDR] = saddr;
320         lookup.vals[LOOKUP_DADDR] = daddr;
321
322         if (tunnel_type & TNL_T_KEY_EXACT) {
323                 lookup.vals[LOOKUP_KEY] = key;
324                 lookup.vals[LOOKUP_TUNNEL_TYPE] = tunnel_type & ~TNL_T_KEY_MATCH;
325
326                 if (key_local_remote_ports) {
327                         tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
328                         if (tbl_node)
329                                 goto found;
330                 }
331
332                 if (key_remote_ports) {
333                         lookup.vals[LOOKUP_SADDR] = 0;
334
335                         tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
336                         if (tbl_node)
337                                 goto found;
338
339                         lookup.vals[LOOKUP_SADDR] = saddr;
340                 }
341         }
342
343         if (tunnel_type & TNL_T_KEY_MATCH) {
344                 lookup.vals[LOOKUP_KEY] = 0;
345                 lookup.vals[LOOKUP_TUNNEL_TYPE] = tunnel_type & ~TNL_T_KEY_EXACT;
346
347                 if (local_remote_ports) {
348                         tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
349                         if (tbl_node)
350                                 goto found;
351                 }
352
353                 if (remote_ports) {
354                         lookup.vals[LOOKUP_SADDR] = 0;
355
356                         tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
357                         if (tbl_node)
358                                 goto found;
359                 }
360         }
361
362         return NULL;
363
364 found:
365         *mutable = lookup.mutable;
366         return tnl_vport_to_vport(tnl_vport_table_cast(tbl_node));
367 }
368
369 static inline void ecn_decapsulate(struct sk_buff *skb)
370 {
371         u8 tos = ip_hdr(skb)->tos;
372
373         if (INET_ECN_is_ce(tos)) {
374                 __be16 protocol = skb->protocol;
375                 unsigned int nw_header = skb_network_offset(skb);
376
377                 if (skb->protocol == htons(ETH_P_8021Q)) {
378                         if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
379                                 return;
380
381                         protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
382                         nw_header += VLAN_HLEN;
383                 }
384
385                 if (protocol == htons(ETH_P_IP)) {
386                         if (unlikely(!pskb_may_pull(skb, nw_header
387                             + sizeof(struct iphdr))))
388                                 return;
389
390                         IP_ECN_set_ce((struct iphdr *)(skb->data + nw_header));
391                 }
392 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
393                 else if (protocol == htons(ETH_P_IPV6)) {
394                         if (unlikely(!pskb_may_pull(skb, nw_header
395                             + sizeof(struct ipv6hdr))))
396                                 return;
397
398                         IP6_ECN_set_ce((struct ipv6hdr *)(skb->data + nw_header));
399                 }
400 #endif
401         }
402 }
403
404 /* Called with rcu_read_lock. */
405 void tnl_rcv(struct vport *vport, struct sk_buff *skb)
406 {
407         skb->pkt_type = PACKET_HOST;
408         skb->protocol = eth_type_trans(skb, skb->dev);
409
410         skb_dst_drop(skb);
411         nf_reset(skb);
412         secpath_reset(skb);
413         skb_reset_network_header(skb);
414
415         ecn_decapsulate(skb);
416
417         skb_push(skb, ETH_HLEN);
418         compute_ip_summed(skb, false);
419
420         vport_receive(vport, skb);
421 }
422
423 static bool check_ipv4_address(__be32 addr)
424 {
425         if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr)
426             || ipv4_is_loopback(addr) || ipv4_is_zeronet(addr))
427                 return false;
428
429         return true;
430 }
431
432 static bool ipv4_should_icmp(struct sk_buff *skb)
433 {
434         struct iphdr *old_iph = ip_hdr(skb);
435
436         /* Don't respond to L2 broadcast. */
437         if (is_multicast_ether_addr(eth_hdr(skb)->h_dest))
438                 return false;
439
440         /* Don't respond to L3 broadcast or invalid addresses. */
441         if (!check_ipv4_address(old_iph->daddr) ||
442             !check_ipv4_address(old_iph->saddr))
443                 return false;
444
445         /* Only respond to the first fragment. */
446         if (old_iph->frag_off & htons(IP_OFFSET))
447                 return false;
448
449         /* Don't respond to ICMP error messages. */
450         if (old_iph->protocol == IPPROTO_ICMP) {
451                 u8 icmp_type, *icmp_typep;
452
453                 icmp_typep = skb_header_pointer(skb, (u8 *)old_iph +
454                                                 (old_iph->ihl << 2) +
455                                                 offsetof(struct icmphdr, type) -
456                                                 skb->data, sizeof(icmp_type),
457                                                 &icmp_type);
458
459                 if (!icmp_typep)
460                         return false;
461
462                 if (*icmp_typep > NR_ICMP_TYPES
463                         || (*icmp_typep <= ICMP_PARAMETERPROB
464                                 && *icmp_typep != ICMP_ECHOREPLY
465                                 && *icmp_typep != ICMP_ECHO))
466                         return false;
467         }
468
469         return true;
470 }
471
472 static void ipv4_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
473                             unsigned int mtu, unsigned int payload_length)
474 {
475         struct iphdr *iph, *old_iph = ip_hdr(skb);
476         struct icmphdr *icmph;
477         u8 *payload;
478
479         iph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
480         icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
481         payload = skb_put(nskb, payload_length);
482
483         /* IP */
484         iph->version            =       4;
485         iph->ihl                =       sizeof(struct iphdr) >> 2;
486         iph->tos                =       (old_iph->tos & IPTOS_TOS_MASK) |
487                                         IPTOS_PREC_INTERNETCONTROL;
488         iph->tot_len            =       htons(sizeof(struct iphdr)
489                                               + sizeof(struct icmphdr)
490                                               + payload_length);
491         get_random_bytes(&iph->id, sizeof(iph->id));
492         iph->frag_off           =       0;
493         iph->ttl                =       IPDEFTTL;
494         iph->protocol           =       IPPROTO_ICMP;
495         iph->daddr              =       old_iph->saddr;
496         iph->saddr              =       old_iph->daddr;
497
498         ip_send_check(iph);
499
500         /* ICMP */
501         icmph->type             =       ICMP_DEST_UNREACH;
502         icmph->code             =       ICMP_FRAG_NEEDED;
503         icmph->un.gateway       =       htonl(mtu);
504         icmph->checksum         =       0;
505
506         nskb->csum = csum_partial((u8 *)icmph, sizeof(struct icmphdr), 0);
507         nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_iph - skb->data,
508                                             payload, payload_length,
509                                             nskb->csum);
510         icmph->checksum = csum_fold(nskb->csum);
511 }
512
513 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
514 static bool ipv6_should_icmp(struct sk_buff *skb)
515 {
516         struct ipv6hdr *old_ipv6h = ipv6_hdr(skb);
517         int addr_type;
518         int payload_off = (u8 *)(old_ipv6h + 1) - skb->data;
519         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
520
521         /* Check source address is valid. */
522         addr_type = ipv6_addr_type(&old_ipv6h->saddr);
523         if (addr_type & IPV6_ADDR_MULTICAST || addr_type == IPV6_ADDR_ANY)
524                 return false;
525
526         /* Don't reply to unspecified addresses. */
527         if (ipv6_addr_type(&old_ipv6h->daddr) == IPV6_ADDR_ANY)
528                 return false;
529
530         /* Don't respond to ICMP error messages. */
531         payload_off = ipv6_skip_exthdr(skb, payload_off, &nexthdr);
532         if (payload_off < 0)
533                 return false;
534
535         if (nexthdr == NEXTHDR_ICMP) {
536                 u8 icmp_type, *icmp_typep;
537
538                 icmp_typep = skb_header_pointer(skb, payload_off +
539                                                 offsetof(struct icmp6hdr,
540                                                         icmp6_type),
541                                                 sizeof(icmp_type), &icmp_type);
542
543                 if (!icmp_typep || !(*icmp_typep & ICMPV6_INFOMSG_MASK))
544                         return false;
545         }
546
547         return true;
548 }
549
550 static void ipv6_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
551                             unsigned int mtu, unsigned int payload_length)
552 {
553         struct ipv6hdr *ipv6h, *old_ipv6h = ipv6_hdr(skb);
554         struct icmp6hdr *icmp6h;
555         u8 *payload;
556
557         ipv6h = (struct ipv6hdr *)skb_put(nskb, sizeof(struct ipv6hdr));
558         icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr));
559         payload = skb_put(nskb, payload_length);
560
561         /* IPv6 */
562         ipv6h->version          =       6;
563         ipv6h->priority         =       0;
564         memset(&ipv6h->flow_lbl, 0, sizeof(ipv6h->flow_lbl));
565         ipv6h->payload_len      =       htons(sizeof(struct icmp6hdr)
566                                               + payload_length);
567         ipv6h->nexthdr          =       NEXTHDR_ICMP;
568         ipv6h->hop_limit        =       IPV6_DEFAULT_HOPLIMIT;
569         ipv6_addr_copy(&ipv6h->daddr, &old_ipv6h->saddr);
570         ipv6_addr_copy(&ipv6h->saddr, &old_ipv6h->daddr);
571
572         /* ICMPv6 */
573         icmp6h->icmp6_type      =       ICMPV6_PKT_TOOBIG;
574         icmp6h->icmp6_code      =       0;
575         icmp6h->icmp6_cksum     =       0;
576         icmp6h->icmp6_mtu       =       htonl(mtu);
577
578         nskb->csum = csum_partial((u8 *)icmp6h, sizeof(struct icmp6hdr), 0);
579         nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_ipv6h - skb->data,
580                                             payload, payload_length,
581                                             nskb->csum);
582         icmp6h->icmp6_cksum = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
583                                                 sizeof(struct icmp6hdr)
584                                                 + payload_length,
585                                                 ipv6h->nexthdr, nskb->csum);
586 }
587 #endif /* IPv6 */
588
589 bool tnl_frag_needed(struct vport *vport, const struct tnl_mutable_config *mutable,
590                      struct sk_buff *skb, unsigned int mtu, __be32 flow_key)
591 {
592         unsigned int eth_hdr_len = ETH_HLEN;
593         unsigned int total_length = 0, header_length = 0, payload_length;
594         struct ethhdr *eh, *old_eh = eth_hdr(skb);
595         struct sk_buff *nskb;
596
597         /* Sanity check */
598         if (skb->protocol == htons(ETH_P_IP)) {
599                 if (mtu < IP_MIN_MTU)
600                         return false;
601
602                 if (!ipv4_should_icmp(skb))
603                         return true;
604         }
605 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
606         else if (skb->protocol == htons(ETH_P_IPV6)) {
607                 if (mtu < IPV6_MIN_MTU)
608                         return false;
609
610                 /*
611                  * In theory we should do PMTUD on IPv6 multicast messages but
612                  * we don't have an address to send from so just fragment.
613                  */
614                 if (ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST)
615                         return false;
616
617                 if (!ipv6_should_icmp(skb))
618                         return true;
619         }
620 #endif
621         else
622                 return false;
623
624         /* Allocate */
625         if (old_eh->h_proto == htons(ETH_P_8021Q))
626                 eth_hdr_len = VLAN_ETH_HLEN;
627
628         payload_length = skb->len - eth_hdr_len;
629         if (skb->protocol == htons(ETH_P_IP)) {
630                 header_length = sizeof(struct iphdr) + sizeof(struct icmphdr);
631                 total_length = min_t(unsigned int, header_length +
632                                                    payload_length, 576);
633         }
634 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
635         else {
636                 header_length = sizeof(struct ipv6hdr) +
637                                 sizeof(struct icmp6hdr);
638                 total_length = min_t(unsigned int, header_length +
639                                                   payload_length, IPV6_MIN_MTU);
640         }
641 #endif
642
643         total_length = min(total_length, mutable->mtu);
644         payload_length = total_length - header_length;
645
646         nskb = dev_alloc_skb(NET_IP_ALIGN + eth_hdr_len + header_length +
647                              payload_length);
648         if (!nskb)
649                 return false;
650
651         skb_reserve(nskb, NET_IP_ALIGN);
652
653         /* Ethernet / VLAN */
654         eh = (struct ethhdr *)skb_put(nskb, eth_hdr_len);
655         memcpy(eh->h_dest, old_eh->h_source, ETH_ALEN);
656         memcpy(eh->h_source, mutable->eth_addr, ETH_ALEN);
657         nskb->protocol = eh->h_proto = old_eh->h_proto;
658         if (old_eh->h_proto == htons(ETH_P_8021Q)) {
659                 struct vlan_ethhdr *vh = (struct vlan_ethhdr *)eh;
660
661                 vh->h_vlan_TCI = vlan_eth_hdr(skb)->h_vlan_TCI;
662                 vh->h_vlan_encapsulated_proto = skb->protocol;
663         }
664         skb_reset_mac_header(nskb);
665
666         /* Protocol */
667         if (skb->protocol == htons(ETH_P_IP))
668                 ipv4_build_icmp(skb, nskb, mtu, payload_length);
669 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
670         else
671                 ipv6_build_icmp(skb, nskb, mtu, payload_length);
672 #endif
673
674         /*
675          * Assume that flow based keys are symmetric with respect to input
676          * and output and use the key that we were going to put on the
677          * outgoing packet for the fake received packet.  If the keys are
678          * not symmetric then PMTUD needs to be disabled since we won't have
679          * any way of synthesizing packets.
680          */
681         if ((mutable->port_config.flags & (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) ==
682             (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION))
683                 OVS_CB(nskb)->tun_id = flow_key;
684
685         compute_ip_summed(nskb, false);
686         vport_receive(vport, nskb);
687
688         return true;
689 }
690
691 static bool check_mtu(struct sk_buff *skb,
692                       struct vport *vport,
693                       const struct tnl_mutable_config *mutable,
694                       const struct rtable *rt, __be16 *frag_offp)
695 {
696         int mtu;
697         __be16 frag_off;
698
699         frag_off = (mutable->port_config.flags & TNL_F_PMTUD) ? htons(IP_DF) : 0;
700         if (frag_off)
701                 mtu = dst_mtu(&rt_dst(rt))
702                         - ETH_HLEN
703                         - mutable->tunnel_hlen
704                         - (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
705         else
706                 mtu = mutable->mtu;
707
708         if (skb->protocol == htons(ETH_P_IP)) {
709                 struct iphdr *old_iph = ip_hdr(skb);
710
711                 frag_off |= old_iph->frag_off & htons(IP_DF);
712                 mtu = max(mtu, IP_MIN_MTU);
713
714                 if ((old_iph->frag_off & htons(IP_DF)) &&
715                     mtu < ntohs(old_iph->tot_len)) {
716                         if (tnl_frag_needed(vport, mutable, skb, mtu, OVS_CB(skb)->tun_id))
717                                 goto drop;
718                 }
719         }
720 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
721         else if (skb->protocol == htons(ETH_P_IPV6)) {
722                 unsigned int packet_length = skb->len - ETH_HLEN
723                         - (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
724
725                 mtu = max(mtu, IPV6_MIN_MTU);
726
727                 /* IPv6 requires PMTUD if the packet is above the minimum MTU. */
728                 if (packet_length > IPV6_MIN_MTU)
729                         frag_off = htons(IP_DF);
730
731                 if (mtu < packet_length) {
732                         if (tnl_frag_needed(vport, mutable, skb, mtu, OVS_CB(skb)->tun_id))
733                                 goto drop;
734                 }
735         }
736 #endif
737
738         *frag_offp = frag_off;
739         return true;
740
741 drop:
742         *frag_offp = 0;
743         return false;
744 }
745
746 static void create_tunnel_header(const struct vport *vport,
747                                  const struct tnl_mutable_config *mutable,
748                                  const struct rtable *rt, void *header)
749 {
750         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
751         struct iphdr *iph = header;
752
753         iph->version    = 4;
754         iph->ihl        = sizeof(struct iphdr) >> 2;
755         iph->frag_off   = htons(IP_DF);
756         iph->protocol   = tnl_vport->tnl_ops->ipproto;
757         iph->tos        = mutable->port_config.tos;
758         iph->daddr      = rt->rt_dst;
759         iph->saddr      = rt->rt_src;
760         iph->ttl        = mutable->port_config.ttl;
761         if (!iph->ttl)
762                 iph->ttl = dst_metric(&rt_dst(rt), RTAX_HOPLIMIT);
763
764         tnl_vport->tnl_ops->build_header(vport, mutable, iph + 1);
765 }
766
767 static inline void *get_cached_header(const struct tnl_cache *cache)
768 {
769         return (void *)cache + ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN);
770 }
771
772 static inline bool check_cache_valid(const struct tnl_cache *cache,
773                                      const struct tnl_mutable_config *mutable)
774 {
775         return cache &&
776 #ifdef NEED_CACHE_TIMEOUT
777                 time_before(jiffies, cache->expiration) &&
778 #endif
779 #ifdef HAVE_RT_GENID
780                 atomic_read(&init_net.ipv4.rt_genid) == cache->rt->rt_genid &&
781 #endif
782 #ifdef HAVE_HH_SEQ
783                 rt_dst(cache->rt).hh->hh_lock.sequence == cache->hh_seq &&
784 #endif
785                 mutable->seq == cache->mutable_seq &&
786                 (!is_internal_dev(rt_dst(cache->rt).dev) ||
787                 (cache->flow && !cache->flow->dead));
788 }
789
790 static int cache_cleaner_cb(struct tbl_node *tbl_node, void *aux)
791 {
792         struct tnl_vport *tnl_vport = tnl_vport_table_cast(tbl_node);
793         const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable);
794         const struct tnl_cache *cache = rcu_dereference(tnl_vport->cache);
795
796         if (cache && !check_cache_valid(cache, mutable) &&
797             spin_trylock_bh(&tnl_vport->cache_lock)) {
798                 assign_cache_rcu(tnl_vport_to_vport(tnl_vport), NULL);
799                 spin_unlock_bh(&tnl_vport->cache_lock);
800         }
801
802         return 0;
803 }
804
805 static void cache_cleaner(struct work_struct *work)
806 {
807         schedule_cache_cleaner();
808
809         rcu_read_lock();
810         tbl_foreach(port_table, cache_cleaner_cb, NULL);
811         rcu_read_unlock();
812 }
813
814 static inline void create_eth_hdr(struct tnl_cache *cache,
815                                   const struct rtable *rt)
816 {
817         void *cache_data = get_cached_header(cache);
818         int hh_len = rt_dst(rt).hh->hh_len;
819         int hh_off = HH_DATA_ALIGN(rt_dst(rt).hh->hh_len) - hh_len;
820
821 #ifdef HAVE_HH_SEQ
822         unsigned hh_seq;
823
824         do {
825                 hh_seq = read_seqbegin(&rt_dst(rt).hh->hh_lock);
826                 memcpy(cache_data, (void *)rt_dst(rt).hh->hh_data + hh_off, hh_len);
827         } while (read_seqretry(&rt_dst(rt).hh->hh_lock, hh_seq));
828
829         cache->hh_seq = hh_seq;
830 #else
831         read_lock_bh(&rt_dst(rt).hh->hh_lock);
832         memcpy(cache_data, (void *)rt_dst(rt).hh->hh_data + hh_off, hh_len);
833         read_unlock_bh(&rt_dst(rt).hh->hh_lock);
834 #endif
835 }
836
837 static struct tnl_cache *build_cache(struct vport *vport,
838                                      const struct tnl_mutable_config *mutable,
839                                      struct rtable *rt)
840 {
841         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
842         struct tnl_cache *cache;
843         void *cache_data;
844         int cache_len;
845
846         if (!(mutable->port_config.flags & TNL_F_HDR_CACHE))
847                 return NULL;
848
849         /*
850          * If there is no entry in the ARP cache or if this device does not
851          * support hard header caching just fall back to the IP stack.
852          */
853         if (!rt_dst(rt).hh)
854                 return NULL;
855
856         /*
857          * If lock is contended fall back to directly building the header.
858          * We're not going to help performance by sitting here spinning.
859          */
860         if (!spin_trylock_bh(&tnl_vport->cache_lock))
861                 return NULL;
862
863         cache = tnl_vport->cache;
864         if (check_cache_valid(cache, mutable))
865                 goto unlock;
866         else
867                 cache = NULL;
868
869         cache_len = rt_dst(rt).hh->hh_len + mutable->tunnel_hlen;
870
871         cache = kzalloc(ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN) +
872                         cache_len, GFP_ATOMIC);
873         if (!cache)
874                 goto unlock;
875
876         cache->len = cache_len;
877
878         create_eth_hdr(cache, rt);
879         cache_data = get_cached_header(cache) + rt_dst(rt).hh->hh_len;
880
881         create_tunnel_header(vport, mutable, rt, cache_data);
882
883         cache->mutable_seq = mutable->seq;
884         cache->rt = rt;
885 #ifdef NEED_CACHE_TIMEOUT
886         cache->expiration = jiffies + tnl_vport->cache_exp_interval;
887 #endif
888
889         if (is_internal_dev(rt_dst(rt).dev)) {
890                 int err;
891                 struct vport *vport;
892                 struct dp_port *dp_port;
893                 struct sk_buff *skb;
894                 bool is_frag;
895                 struct odp_flow_key flow_key;
896                 struct tbl_node *flow_node;
897
898                 vport = internal_dev_get_vport(rt_dst(rt).dev);
899                 if (!vport)
900                         goto done;
901
902                 dp_port = vport_get_dp_port(vport);
903                 if (!dp_port)
904                         goto done;
905
906                 skb = alloc_skb(cache->len, GFP_ATOMIC);
907                 if (!skb)
908                         goto done;
909
910                 __skb_put(skb, cache->len);
911                 memcpy(skb->data, get_cached_header(cache), cache->len);
912
913                 err = flow_extract(skb, dp_port->port_no, &flow_key, &is_frag);
914
915                 kfree_skb(skb);
916                 if (err || is_frag)
917                         goto done;
918
919                 flow_node = tbl_lookup(rcu_dereference(dp_port->dp->table),
920                                        &flow_key, flow_hash(&flow_key),
921                                        flow_cmp);
922                 if (flow_node) {
923                         struct sw_flow *flow = flow_cast(flow_node);
924
925                         cache->flow = flow;
926                         flow_hold(flow);
927                 }
928         }
929
930 done:
931         assign_cache_rcu(vport, cache);
932
933 unlock:
934         spin_unlock_bh(&tnl_vport->cache_lock);
935
936         return cache;
937 }
938
939 static struct rtable *find_route(struct vport *vport,
940                                  const struct tnl_mutable_config *mutable,
941                                  u8 tos, struct tnl_cache **cache)
942 {
943         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
944         struct tnl_cache *cur_cache = rcu_dereference(tnl_vport->cache);
945
946         *cache = NULL;
947         tos = RT_TOS(tos);
948
949         if (likely(tos == mutable->port_config.tos &&
950                    check_cache_valid(cur_cache, mutable))) {
951                 *cache = cur_cache;
952                 return cur_cache->rt;
953         } else {
954                 struct rtable *rt;
955                 struct flowi fl = { .nl_u = { .ip4_u =
956                                               { .daddr = mutable->port_config.daddr,
957                                                 .saddr = mutable->port_config.saddr,
958                                                 .tos = tos } },
959                                     .proto = tnl_vport->tnl_ops->ipproto };
960
961                 if (unlikely(ip_route_output_key(&init_net, &rt, &fl)))
962                         return NULL;
963
964                 if (likely(tos == mutable->port_config.tos))
965                         *cache = build_cache(vport, mutable, rt);
966
967                 return rt;
968         }
969 }
970
971 static struct sk_buff *check_headroom(struct sk_buff *skb, int headroom)
972 {
973         if (skb_headroom(skb) < headroom || skb_header_cloned(skb)) {
974                 struct sk_buff *nskb = skb_realloc_headroom(skb, headroom + 16);
975                 if (unlikely(!nskb)) {
976                         kfree_skb(skb);
977                         return ERR_PTR(-ENOMEM);
978                 }
979
980                 set_skb_csum_bits(skb, nskb);
981
982                 if (skb->sk)
983                         skb_set_owner_w(nskb, skb->sk);
984
985                 kfree_skb(skb);
986                 return nskb;
987         }
988
989         return skb;
990 }
991
992 static inline bool need_linearize(const struct sk_buff *skb)
993 {
994         int i;
995
996         if (unlikely(skb_shinfo(skb)->frag_list))
997                 return true;
998
999         /*
1000          * Generally speaking we should linearize if there are paged frags.
1001          * However, if all of the refcounts are 1 we know nobody else can
1002          * change them from underneath us and we can skip the linearization.
1003          */
1004         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1005                 if (unlikely(page_count(skb_shinfo(skb)->frags[0].page) > 1))
1006                         return true;
1007
1008         return false;
1009 }
1010
1011 static struct sk_buff *handle_offloads(struct sk_buff *skb,
1012                                        const struct tnl_mutable_config *mutable,
1013                                        const struct rtable *rt)
1014 {
1015         int min_headroom;
1016         int err;
1017
1018         forward_ip_summed(skb);
1019
1020         err = vswitch_skb_checksum_setup(skb);
1021         if (unlikely(err))
1022                 goto error_free;
1023
1024         min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
1025                         + mutable->tunnel_hlen;
1026
1027         if (skb_is_gso(skb)) {
1028                 struct sk_buff *nskb;
1029
1030                 /*
1031                  * If we are doing GSO on a pskb it is better to make sure that
1032                  * the headroom is correct now.  We will only have to copy the
1033                  * portion in the linear data area and GSO will preserve
1034                  * headroom when it creates the segments.  This is particularly
1035                  * beneficial on Xen where we get a lot of GSO pskbs.
1036                  * Conversely, we avoid copying if it is just to get our own
1037                  * writable clone because GSO will do the copy for us.
1038                  */
1039                 if (skb_headroom(skb) < min_headroom) {
1040                         skb = check_headroom(skb, min_headroom);
1041                         if (unlikely(IS_ERR(skb))) {
1042                                 err = PTR_ERR(skb);
1043                                 goto error;
1044                         }
1045                 }
1046
1047                 nskb = skb_gso_segment(skb, 0);
1048                 kfree_skb(skb);
1049                 if (unlikely(IS_ERR(nskb))) {
1050                         err = PTR_ERR(nskb);
1051                         goto error;
1052                 }
1053
1054                 skb = nskb;
1055         } else {
1056                 skb = check_headroom(skb, min_headroom);
1057                 if (unlikely(IS_ERR(skb))) {
1058                         err = PTR_ERR(skb);
1059                         goto error;
1060                 }
1061
1062                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1063                         /*
1064                          * Pages aren't locked and could change at any time.
1065                          * If this happens after we compute the checksum, the
1066                          * checksum will be wrong.  We linearize now to avoid
1067                          * this problem.
1068                          */
1069                         if (unlikely(need_linearize(skb))) {
1070                                 err = __skb_linearize(skb);
1071                                 if (unlikely(err))
1072                                         goto error_free;
1073                         }
1074
1075                         err = skb_checksum_help(skb);
1076                         if (unlikely(err))
1077                                 goto error_free;
1078                 } else if (skb->ip_summed == CHECKSUM_COMPLETE)
1079                         skb->ip_summed = CHECKSUM_NONE;
1080         }
1081
1082         return skb;
1083
1084 error_free:
1085         kfree_skb(skb);
1086 error:
1087         return ERR_PTR(err);
1088 }
1089
1090 static int send_frags(struct sk_buff *skb,
1091                       const struct tnl_mutable_config *mutable)
1092 {
1093         int sent_len;
1094         int err;
1095
1096         sent_len = 0;
1097         while (skb) {
1098                 struct sk_buff *next = skb->next;
1099                 int frag_len = skb->len - mutable->tunnel_hlen;
1100
1101                 skb->next = NULL;
1102                 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
1103
1104                 err = ip_local_out(skb);
1105                 if (likely(net_xmit_eval(err) == 0))
1106                         sent_len += frag_len;
1107                 else {
1108                         skb = next;
1109                         goto free_frags;
1110                 }
1111
1112                 skb = next;
1113         }
1114
1115         return sent_len;
1116
1117 free_frags:
1118         /*
1119          * There's no point in continuing to send fragments once one has been
1120          * dropped so just free the rest.  This may help improve the congestion
1121          * that caused the first packet to be dropped.
1122          */
1123         tnl_free_linked_skbs(skb);
1124         return sent_len;
1125 }
1126
1127 int tnl_send(struct vport *vport, struct sk_buff *skb)
1128 {
1129         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1130         const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable);
1131
1132         enum vport_err_type err = VPORT_E_TX_ERROR;
1133         struct rtable *rt;
1134         struct dst_entry *unattached_dst = NULL;
1135         struct tnl_cache *cache;
1136         int sent_len = 0;
1137         __be16 frag_off;
1138         u8 ttl;
1139         u8 inner_tos;
1140         u8 tos;
1141
1142         /* Validate the protocol headers before we try to use them. */
1143         if (skb->protocol == htons(ETH_P_8021Q)) {
1144                 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
1145                         goto error_free;
1146
1147                 skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
1148                 skb_set_network_header(skb, VLAN_ETH_HLEN);
1149         }
1150
1151         if (skb->protocol == htons(ETH_P_IP)) {
1152                 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
1153                     + sizeof(struct iphdr))))
1154                         skb->protocol = 0;
1155         }
1156 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1157         else if (skb->protocol == htons(ETH_P_IPV6)) {
1158                 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
1159                     + sizeof(struct ipv6hdr))))
1160                         skb->protocol = 0;
1161         }
1162 #endif
1163
1164         /* ToS */
1165         if (skb->protocol == htons(ETH_P_IP))
1166                 inner_tos = ip_hdr(skb)->tos;
1167 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1168         else if (skb->protocol == htons(ETH_P_IPV6))
1169                 inner_tos = ipv6_get_dsfield(ipv6_hdr(skb));
1170 #endif
1171         else
1172                 inner_tos = 0;
1173
1174         if (mutable->port_config.flags & TNL_F_TOS_INHERIT)
1175                 tos = inner_tos;
1176         else
1177                 tos = mutable->port_config.tos;
1178
1179         tos = INET_ECN_encapsulate(tos, inner_tos);
1180
1181         /* Route lookup */
1182         rt = find_route(vport, mutable, tos, &cache);
1183         if (unlikely(!rt))
1184                 goto error_free;
1185         if (unlikely(!cache))
1186                 unattached_dst = &rt_dst(rt);
1187
1188         /* Reset SKB */
1189         nf_reset(skb);
1190         secpath_reset(skb);
1191         skb_dst_drop(skb);
1192
1193         /* Offloading */
1194         skb = handle_offloads(skb, mutable, rt);
1195         if (unlikely(IS_ERR(skb)))
1196                 goto error;
1197
1198         /* MTU */
1199         if (unlikely(!check_mtu(skb, vport, mutable, rt, &frag_off))) {
1200                 err = VPORT_E_TX_DROPPED;
1201                 goto error_free;
1202         }
1203
1204         /*
1205          * If we are over the MTU, allow the IP stack to handle fragmentation.
1206          * Fragmentation is a slow path anyways.
1207          */
1208         if (unlikely(skb->len + mutable->tunnel_hlen > dst_mtu(&rt_dst(rt)) &&
1209                      cache)) {
1210                 unattached_dst = &rt_dst(rt);
1211                 dst_hold(unattached_dst);
1212                 cache = NULL;
1213         }
1214
1215         /* TTL */
1216         ttl = mutable->port_config.ttl;
1217         if (!ttl)
1218                 ttl = dst_metric(&rt_dst(rt), RTAX_HOPLIMIT);
1219
1220         if (mutable->port_config.flags & TNL_F_TTL_INHERIT) {
1221                 if (skb->protocol == htons(ETH_P_IP))
1222                         ttl = ip_hdr(skb)->ttl;
1223 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1224                 else if (skb->protocol == htons(ETH_P_IPV6))
1225                         ttl = ipv6_hdr(skb)->hop_limit;
1226 #endif
1227         }
1228
1229         while (skb) {
1230                 struct iphdr *iph;
1231                 struct sk_buff *next_skb = skb->next;
1232                 skb->next = NULL;
1233
1234                 if (likely(cache)) {
1235                         skb_push(skb, cache->len);
1236                         memcpy(skb->data, get_cached_header(cache), cache->len);
1237                         skb_reset_mac_header(skb);
1238                         skb_set_network_header(skb, rt_dst(rt).hh->hh_len);
1239
1240                 } else {
1241                         skb_push(skb, mutable->tunnel_hlen);
1242                         create_tunnel_header(vport, mutable, rt, skb->data);
1243                         skb_reset_network_header(skb);
1244
1245                         if (next_skb)
1246                                 skb_dst_set(skb, dst_clone(unattached_dst));
1247                         else {
1248                                 skb_dst_set(skb, unattached_dst);
1249                                 unattached_dst = NULL;
1250                         }
1251                 }
1252                 skb_set_transport_header(skb, skb_network_offset(skb) + sizeof(struct iphdr));
1253
1254                 iph = ip_hdr(skb);
1255                 iph->tos = tos;
1256                 iph->ttl = ttl;
1257                 iph->frag_off = frag_off;
1258                 ip_select_ident(iph, &rt_dst(rt), NULL);
1259
1260                 skb = tnl_vport->tnl_ops->update_header(vport, mutable, &rt_dst(rt), skb);
1261                 if (unlikely(!skb))
1262                         goto next;
1263
1264                 if (likely(cache)) {
1265                         int orig_len = skb->len - cache->len;
1266                         struct vport *cache_vport = internal_dev_get_vport(rt_dst(rt).dev);
1267
1268                         skb->protocol = htons(ETH_P_IP);
1269                         iph->tot_len = htons(skb->len - skb_network_offset(skb));
1270                         ip_send_check(iph);
1271
1272                         if (cache_vport) {
1273                                 OVS_CB(skb)->flow = cache->flow;
1274                                 compute_ip_summed(skb, true);
1275                                 vport_receive(cache_vport, skb);
1276                                 sent_len += orig_len;
1277                         } else {
1278                                 int err;
1279
1280                                 skb->dev = rt_dst(rt).dev;
1281                                 err = dev_queue_xmit(skb);
1282
1283                                 if (likely(net_xmit_eval(err) == 0))
1284                                         sent_len += orig_len;
1285                         }
1286                 } else
1287                         sent_len += send_frags(skb, mutable);
1288
1289 next:
1290                 skb = next_skb;
1291         }
1292
1293         if (unlikely(sent_len == 0))
1294                 vport_record_error(vport, VPORT_E_TX_DROPPED);
1295
1296         goto out;
1297
1298 error_free:
1299         tnl_free_linked_skbs(skb);
1300 error:
1301         dst_release(unattached_dst);
1302         vport_record_error(vport, err);
1303 out:
1304         return sent_len;
1305 }
1306
1307 static int set_config(const void __user *uconfig, const struct tnl_ops *tnl_ops,
1308                       const struct vport *cur_vport,
1309                       struct tnl_mutable_config *mutable)
1310 {
1311         const struct vport *old_vport;
1312         const struct tnl_mutable_config *old_mutable;
1313
1314         if (copy_from_user(&mutable->port_config, uconfig, sizeof(struct tnl_port_config)))
1315                 return -EFAULT;
1316
1317         if (mutable->port_config.daddr == 0)
1318                 return -EINVAL;
1319
1320         if (mutable->port_config.tos != RT_TOS(mutable->port_config.tos))
1321                 return -EINVAL;
1322
1323         mutable->tunnel_hlen = tnl_ops->hdr_len(&mutable->port_config);
1324         if (mutable->tunnel_hlen < 0)
1325                 return mutable->tunnel_hlen;
1326
1327         mutable->tunnel_hlen += sizeof(struct iphdr);
1328
1329         mutable->tunnel_type = tnl_ops->tunnel_type;
1330         if (mutable->port_config.flags & TNL_F_IN_KEY_MATCH) {
1331                 mutable->tunnel_type |= TNL_T_KEY_MATCH;
1332                 mutable->port_config.in_key = 0;
1333         } else
1334                 mutable->tunnel_type |= TNL_T_KEY_EXACT;
1335
1336         old_vport = tnl_find_port(mutable->port_config.saddr,
1337                                   mutable->port_config.daddr,
1338                                   mutable->port_config.in_key,
1339                                   mutable->tunnel_type,
1340                                   &old_mutable);
1341
1342         if (old_vport && old_vport != cur_vport)
1343                 return -EEXIST;
1344
1345         if (mutable->port_config.flags & TNL_F_OUT_KEY_ACTION)
1346                 mutable->port_config.out_key = 0;
1347
1348         return 0;
1349 }
1350
1351 struct vport *tnl_create(const char *name, const void __user *config,
1352                          const struct vport_ops *vport_ops,
1353                          const struct tnl_ops *tnl_ops)
1354 {
1355         struct vport *vport;
1356         struct tnl_vport *tnl_vport;
1357         int initial_frag_id;
1358         int err;
1359
1360         vport = vport_alloc(sizeof(struct tnl_vport), vport_ops);
1361         if (IS_ERR(vport)) {
1362                 err = PTR_ERR(vport);
1363                 goto error;
1364         }
1365
1366         tnl_vport = tnl_vport_priv(vport);
1367
1368         strcpy(tnl_vport->name, name);
1369         tnl_vport->tnl_ops = tnl_ops;
1370
1371         tnl_vport->mutable = kzalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL);
1372         if (!tnl_vport->mutable) {
1373                 err = -ENOMEM;
1374                 goto error_free_vport;
1375         }
1376
1377         vport_gen_rand_ether_addr(tnl_vport->mutable->eth_addr);
1378         tnl_vport->mutable->mtu = ETH_DATA_LEN;
1379
1380         get_random_bytes(&initial_frag_id, sizeof(int));
1381         atomic_set(&tnl_vport->frag_id, initial_frag_id);
1382
1383         err = set_config(config, tnl_ops, NULL, tnl_vport->mutable);
1384         if (err)
1385                 goto error_free_mutable;
1386
1387         spin_lock_init(&tnl_vport->cache_lock);
1388
1389 #ifdef NEED_CACHE_TIMEOUT
1390         tnl_vport->cache_exp_interval = MAX_CACHE_EXP -
1391                                         (net_random() % (MAX_CACHE_EXP / 2));
1392 #endif
1393
1394         err = add_port(vport);
1395         if (err)
1396                 goto error_free_mutable;
1397
1398         return vport;
1399
1400 error_free_mutable:
1401         kfree(tnl_vport->mutable);
1402 error_free_vport:
1403         vport_free(vport);
1404 error:
1405         return ERR_PTR(err);
1406 }
1407
1408 int tnl_modify(struct vport *vport, const void __user *config)
1409 {
1410         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1411         struct tnl_mutable_config *mutable;
1412         int err;
1413
1414         mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL);
1415         if (!mutable) {
1416                 err = -ENOMEM;
1417                 goto error;
1418         }
1419
1420         err = set_config(config, tnl_vport->tnl_ops, vport, mutable);
1421         if (err)
1422                 goto error_free;
1423
1424         mutable->seq++;
1425
1426         err = move_port(vport, mutable);
1427         if (err)
1428                 goto error_free;
1429
1430         return 0;
1431
1432 error_free:
1433         kfree(mutable);
1434 error:
1435         return err;
1436 }
1437
1438 static void free_port_rcu(struct rcu_head *rcu)
1439 {
1440         struct tnl_vport *tnl_vport = container_of(rcu, struct tnl_vport, rcu);
1441
1442         spin_lock_bh(&tnl_vport->cache_lock);
1443         free_cache(tnl_vport->cache);
1444         spin_unlock_bh(&tnl_vport->cache_lock);
1445
1446         kfree(tnl_vport->mutable);
1447         vport_free(tnl_vport_to_vport(tnl_vport));
1448 }
1449
1450 int tnl_destroy(struct vport *vport)
1451 {
1452         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1453         const struct tnl_mutable_config *old_mutable;
1454
1455         if (vport == tnl_find_port(tnl_vport->mutable->port_config.saddr,
1456             tnl_vport->mutable->port_config.daddr,
1457             tnl_vport->mutable->port_config.in_key,
1458             tnl_vport->mutable->tunnel_type,
1459             &old_mutable))
1460                 del_port(vport);
1461
1462         call_rcu(&tnl_vport->rcu, free_port_rcu);
1463
1464         return 0;
1465 }
1466
1467 int tnl_set_mtu(struct vport *vport, int mtu)
1468 {
1469         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1470         struct tnl_mutable_config *mutable;
1471
1472         mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL);
1473         if (!mutable)
1474                 return -ENOMEM;
1475
1476         mutable->mtu = mtu;
1477         assign_config_rcu(vport, mutable);
1478
1479         return 0;
1480 }
1481
1482 int tnl_set_addr(struct vport *vport, const unsigned char *addr)
1483 {
1484         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1485         struct tnl_mutable_config *mutable;
1486
1487         mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL);
1488         if (!mutable)
1489                 return -ENOMEM;
1490
1491         memcpy(mutable->eth_addr, addr, ETH_ALEN);
1492         assign_config_rcu(vport, mutable);
1493
1494         return 0;
1495 }
1496
1497 const char *tnl_get_name(const struct vport *vport)
1498 {
1499         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1500         return tnl_vport->name;
1501 }
1502
1503 const unsigned char *tnl_get_addr(const struct vport *vport)
1504 {
1505         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1506         return rcu_dereference(tnl_vport->mutable)->eth_addr;
1507 }
1508
1509 int tnl_get_mtu(const struct vport *vport)
1510 {
1511         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1512         return rcu_dereference(tnl_vport->mutable)->mtu;
1513 }
1514
1515 void tnl_free_linked_skbs(struct sk_buff *skb)
1516 {
1517         if (unlikely(!skb))
1518                 return;
1519
1520         while (skb) {
1521                 struct sk_buff *next = skb->next;
1522                 kfree_skb(skb);
1523                 skb = next;
1524         }
1525 }