2 * Copyright (c) 2010 Nicira Networks.
3 * Distributed under the terms of the GNU GPL version 2.
5 * Significant portions of this file may be copied from parts of the Linux
6 * kernel, by Linus Torvalds and others.
9 #include <linux/if_arp.h>
10 #include <linux/if_ether.h>
12 #include <linux/if_vlan.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>
20 #include <net/dsfield.h>
23 #include <net/inet_ecn.h>
25 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
28 #include <net/route.h>
37 #include "vport-generic.h"
38 #include "vport-internal_dev.h"
40 #ifdef NEED_CACHE_TIMEOUT
42 * On kernels where we can't quickly detect changes in the rest of the system
43 * we use an expiration time to invalidate the cache. A shorter expiration
44 * reduces the length of time that we may potentially blackhole packets while
45 * a longer time increases performance by reducing the frequency that the
46 * cache needs to be rebuilt. A variety of factors may cause the cache to be
47 * invalidated before the expiration time but this is the maximum. The time
48 * is expressed in jiffies.
50 #define MAX_CACHE_EXP HZ
54 * Interval to check for and remove caches that are no longer valid. Caches
55 * are checked for validity before they are used for packet encapsulation and
56 * old caches are removed at that time. However, if no packets are sent through
57 * the tunnel then the cache will never be destroyed. Since it holds
58 * references to a number of system objects, the cache will continue to use
59 * system resources by not allowing those objects to be destroyed. The cache
60 * cleaner is periodically run to free invalid caches. It does not
61 * significantly affect system performance. A lower interval will release
62 * resources faster but will itself consume resources by requiring more frequent
63 * checks. A longer interval may result in messages being printed to the kernel
64 * message buffer about unreleased resources. The interval is expressed in
67 #define CACHE_CLEANER_INTERVAL (5 * HZ)
69 #define CACHE_DATA_ALIGN 16
71 static struct tbl __rcu *port_table __read_mostly;
73 static void cache_cleaner(struct work_struct *work);
74 static DECLARE_DELAYED_WORK(cache_cleaner_wq, cache_cleaner);
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.
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;
86 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
87 #define rt_dst(rt) (rt->dst)
89 #define rt_dst(rt) (rt->u.dst)
92 static inline struct vport *tnl_vport_to_vport(const struct tnl_vport *tnl_vport)
94 return vport_from_priv(tnl_vport);
97 static inline struct tnl_vport *tnl_vport_table_cast(const struct tbl_node *node)
99 return container_of(node, struct tnl_vport, tbl_node);
102 static inline void schedule_cache_cleaner(void)
104 schedule_delayed_work(&cache_cleaner_wq, CACHE_CLEANER_INTERVAL);
107 static void free_cache(struct tnl_cache *cache)
112 flow_put(cache->flow);
113 ip_rt_put(cache->rt);
117 static void free_config_rcu(struct rcu_head *rcu)
119 struct tnl_mutable_config *c = container_of(rcu, struct tnl_mutable_config, rcu);
123 static void free_cache_rcu(struct rcu_head *rcu)
125 struct tnl_cache *c = container_of(rcu, struct tnl_cache, rcu);
129 static void assign_config_rcu(struct vport *vport,
130 struct tnl_mutable_config *new_config)
132 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
133 struct tnl_mutable_config *old_config;
135 old_config = rtnl_dereference(tnl_vport->mutable);
136 rcu_assign_pointer(tnl_vport->mutable, new_config);
137 call_rcu(&old_config->rcu, free_config_rcu);
140 static void assign_cache_rcu(struct vport *vport, struct tnl_cache *new_cache)
142 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
143 struct tnl_cache *old_cache;
145 old_cache = tnl_vport->cache;
146 rcu_assign_pointer(tnl_vport->cache, new_cache);
149 call_rcu(&old_cache->rcu, free_cache_rcu);
152 static unsigned int *find_port_pool(const struct tnl_mutable_config *mutable)
154 if (mutable->port_config.flags & TNL_F_IN_KEY_MATCH) {
155 if (mutable->port_config.saddr)
156 return &local_remote_ports;
158 return &remote_ports;
160 if (mutable->port_config.saddr)
161 return &key_local_remote_ports;
163 return &key_remote_ports;
167 struct port_lookup_key {
168 const struct tnl_mutable_config *mutable;
176 * Modifies 'target' to store the rcu_dereferenced pointer that was used to do
179 static int port_cmp(const struct tbl_node *node, void *target)
181 const struct tnl_vport *tnl_vport = tnl_vport_table_cast(node);
182 struct port_lookup_key *lookup = target;
184 lookup->mutable = rcu_dereference_rtnl(tnl_vport->mutable);
186 return (lookup->mutable->tunnel_type == lookup->tunnel_type &&
187 lookup->mutable->port_config.daddr == lookup->daddr &&
188 lookup->mutable->port_config.in_key == lookup->key &&
189 lookup->mutable->port_config.saddr == lookup->saddr);
192 static u32 port_hash(struct port_lookup_key *k)
194 u32 x = jhash_3words((__force u32)k->saddr, (__force u32)k->daddr,
196 return jhash_2words((__force u64)k->key >> 32, (__force u32)k->key, x);
199 static u32 mutable_hash(const struct tnl_mutable_config *mutable)
201 struct port_lookup_key lookup;
203 lookup.saddr = mutable->port_config.saddr;
204 lookup.daddr = mutable->port_config.daddr;
205 lookup.key = mutable->port_config.in_key;
206 lookup.tunnel_type = mutable->tunnel_type;
208 return port_hash(&lookup);
211 static void check_table_empty(void)
213 struct tbl *old_table = rtnl_dereference(port_table);
215 if (tbl_count(old_table) == 0) {
216 cancel_delayed_work_sync(&cache_cleaner_wq);
217 rcu_assign_pointer(port_table, NULL);
218 tbl_deferred_destroy(old_table, NULL);
222 static int add_port(struct vport *vport)
224 struct tbl *cur_table = rtnl_dereference(port_table);
225 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
229 struct tbl *new_table;
231 new_table = tbl_create(0);
235 rcu_assign_pointer(port_table, new_table);
236 schedule_cache_cleaner();
238 } else if (tbl_count(cur_table) > tbl_n_buckets(cur_table)) {
239 struct tbl *new_table;
241 new_table = tbl_expand(cur_table);
242 if (IS_ERR(new_table))
243 return PTR_ERR(new_table);
245 rcu_assign_pointer(port_table, new_table);
246 tbl_deferred_destroy(cur_table, NULL);
249 err = tbl_insert(rtnl_dereference(port_table), &tnl_vport->tbl_node,
250 mutable_hash(rtnl_dereference(tnl_vport->mutable)));
256 (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
261 static int move_port(struct vport *vport, struct tnl_mutable_config *new_mutable)
264 struct tbl *cur_table = rtnl_dereference(port_table);
265 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
268 hash = mutable_hash(new_mutable);
269 if (hash == tnl_vport->tbl_node.hash)
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.
277 err = tbl_remove(cur_table, &tnl_vport->tbl_node);
281 err = tbl_insert(cur_table, &tnl_vport->tbl_node, hash);
283 (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
289 (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
290 assign_config_rcu(vport, new_mutable);
291 (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
296 static int del_port(struct vport *vport)
298 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
301 err = tbl_remove(rtnl_dereference(port_table), &tnl_vport->tbl_node);
306 (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
311 struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be64 key,
313 const struct tnl_mutable_config **mutable)
315 struct port_lookup_key lookup;
316 struct tbl *table = rcu_dereference_rtnl(port_table);
317 struct tbl_node *tbl_node;
319 if (unlikely(!table))
322 lookup.saddr = saddr;
323 lookup.daddr = daddr;
325 if (tunnel_type & TNL_T_KEY_EXACT) {
327 lookup.tunnel_type = tunnel_type & ~TNL_T_KEY_MATCH;
329 if (key_local_remote_ports) {
330 tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
335 if (key_remote_ports) {
338 tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
342 lookup.saddr = saddr;
346 if (tunnel_type & TNL_T_KEY_MATCH) {
348 lookup.tunnel_type = tunnel_type & ~TNL_T_KEY_EXACT;
350 if (local_remote_ports) {
351 tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
359 tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
368 *mutable = lookup.mutable;
369 return tnl_vport_to_vport(tnl_vport_table_cast(tbl_node));
372 static inline void ecn_decapsulate(struct sk_buff *skb)
374 /* This is accessing the outer IP header of the tunnel, which we've
375 * already validated to be OK. skb->data is currently set to the start
376 * of the inner Ethernet header, and we've validated ETH_HLEN.
378 if (unlikely(INET_ECN_is_ce(ip_hdr(skb)->tos))) {
379 __be16 protocol = skb->protocol;
381 skb_set_network_header(skb, ETH_HLEN);
383 if (skb->protocol == htons(ETH_P_8021Q)) {
384 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
387 protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
388 skb_set_network_header(skb, VLAN_ETH_HLEN);
391 if (protocol == htons(ETH_P_IP)) {
392 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
393 + sizeof(struct iphdr))))
396 IP_ECN_set_ce(ip_hdr(skb));
398 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
399 else if (protocol == htons(ETH_P_IPV6)) {
400 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
401 + sizeof(struct ipv6hdr))))
404 IP6_ECN_set_ce(ipv6_hdr(skb));
410 /* Called with rcu_read_lock. */
411 void tnl_rcv(struct vport *vport, struct sk_buff *skb)
413 /* Packets received by this function are in the following state:
414 * - skb->data points to the inner Ethernet header.
415 * - The inner Ethernet header is in the linear data area.
416 * - skb->csum does not include the inner Ethernet header.
417 * - The layer pointers point at the outer headers.
420 struct ethhdr *eh = (struct ethhdr *)skb->data;
422 if (likely(ntohs(eh->h_proto) >= 1536))
423 skb->protocol = eh->h_proto;
425 skb->protocol = htons(ETH_P_802_2);
431 ecn_decapsulate(skb);
432 compute_ip_summed(skb, false);
434 vport_receive(vport, skb);
437 static bool check_ipv4_address(__be32 addr)
439 if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr)
440 || ipv4_is_loopback(addr) || ipv4_is_zeronet(addr))
446 static bool ipv4_should_icmp(struct sk_buff *skb)
448 struct iphdr *old_iph = ip_hdr(skb);
450 /* Don't respond to L2 broadcast. */
451 if (is_multicast_ether_addr(eth_hdr(skb)->h_dest))
454 /* Don't respond to L3 broadcast or invalid addresses. */
455 if (!check_ipv4_address(old_iph->daddr) ||
456 !check_ipv4_address(old_iph->saddr))
459 /* Only respond to the first fragment. */
460 if (old_iph->frag_off & htons(IP_OFFSET))
463 /* Don't respond to ICMP error messages. */
464 if (old_iph->protocol == IPPROTO_ICMP) {
465 u8 icmp_type, *icmp_typep;
467 icmp_typep = skb_header_pointer(skb, (u8 *)old_iph +
468 (old_iph->ihl << 2) +
469 offsetof(struct icmphdr, type) -
470 skb->data, sizeof(icmp_type),
476 if (*icmp_typep > NR_ICMP_TYPES
477 || (*icmp_typep <= ICMP_PARAMETERPROB
478 && *icmp_typep != ICMP_ECHOREPLY
479 && *icmp_typep != ICMP_ECHO))
486 static void ipv4_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
487 unsigned int mtu, unsigned int payload_length)
489 struct iphdr *iph, *old_iph = ip_hdr(skb);
490 struct icmphdr *icmph;
493 iph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
494 icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
495 payload = skb_put(nskb, payload_length);
499 iph->ihl = sizeof(struct iphdr) >> 2;
500 iph->tos = (old_iph->tos & IPTOS_TOS_MASK) |
501 IPTOS_PREC_INTERNETCONTROL;
502 iph->tot_len = htons(sizeof(struct iphdr)
503 + sizeof(struct icmphdr)
505 get_random_bytes(&iph->id, sizeof(iph->id));
508 iph->protocol = IPPROTO_ICMP;
509 iph->daddr = old_iph->saddr;
510 iph->saddr = old_iph->daddr;
515 icmph->type = ICMP_DEST_UNREACH;
516 icmph->code = ICMP_FRAG_NEEDED;
517 icmph->un.gateway = htonl(mtu);
520 nskb->csum = csum_partial((u8 *)icmph, sizeof(struct icmphdr), 0);
521 nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_iph - skb->data,
522 payload, payload_length,
524 icmph->checksum = csum_fold(nskb->csum);
527 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
528 static bool ipv6_should_icmp(struct sk_buff *skb)
530 struct ipv6hdr *old_ipv6h = ipv6_hdr(skb);
532 int payload_off = (u8 *)(old_ipv6h + 1) - skb->data;
533 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
535 /* Check source address is valid. */
536 addr_type = ipv6_addr_type(&old_ipv6h->saddr);
537 if (addr_type & IPV6_ADDR_MULTICAST || addr_type == IPV6_ADDR_ANY)
540 /* Don't reply to unspecified addresses. */
541 if (ipv6_addr_type(&old_ipv6h->daddr) == IPV6_ADDR_ANY)
544 /* Don't respond to ICMP error messages. */
545 payload_off = ipv6_skip_exthdr(skb, payload_off, &nexthdr);
549 if (nexthdr == NEXTHDR_ICMP) {
550 u8 icmp_type, *icmp_typep;
552 icmp_typep = skb_header_pointer(skb, payload_off +
553 offsetof(struct icmp6hdr,
555 sizeof(icmp_type), &icmp_type);
557 if (!icmp_typep || !(*icmp_typep & ICMPV6_INFOMSG_MASK))
564 static void ipv6_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
565 unsigned int mtu, unsigned int payload_length)
567 struct ipv6hdr *ipv6h, *old_ipv6h = ipv6_hdr(skb);
568 struct icmp6hdr *icmp6h;
571 ipv6h = (struct ipv6hdr *)skb_put(nskb, sizeof(struct ipv6hdr));
572 icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr));
573 payload = skb_put(nskb, payload_length);
578 memset(&ipv6h->flow_lbl, 0, sizeof(ipv6h->flow_lbl));
579 ipv6h->payload_len = htons(sizeof(struct icmp6hdr)
581 ipv6h->nexthdr = NEXTHDR_ICMP;
582 ipv6h->hop_limit = IPV6_DEFAULT_HOPLIMIT;
583 ipv6_addr_copy(&ipv6h->daddr, &old_ipv6h->saddr);
584 ipv6_addr_copy(&ipv6h->saddr, &old_ipv6h->daddr);
587 icmp6h->icmp6_type = ICMPV6_PKT_TOOBIG;
588 icmp6h->icmp6_code = 0;
589 icmp6h->icmp6_cksum = 0;
590 icmp6h->icmp6_mtu = htonl(mtu);
592 nskb->csum = csum_partial((u8 *)icmp6h, sizeof(struct icmp6hdr), 0);
593 nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_ipv6h - skb->data,
594 payload, payload_length,
596 icmp6h->icmp6_cksum = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
597 sizeof(struct icmp6hdr)
599 ipv6h->nexthdr, nskb->csum);
603 bool tnl_frag_needed(struct vport *vport, const struct tnl_mutable_config *mutable,
604 struct sk_buff *skb, unsigned int mtu, __be64 flow_key)
606 unsigned int eth_hdr_len = ETH_HLEN;
607 unsigned int total_length = 0, header_length = 0, payload_length;
608 struct ethhdr *eh, *old_eh = eth_hdr(skb);
609 struct sk_buff *nskb;
612 if (skb->protocol == htons(ETH_P_IP)) {
613 if (mtu < IP_MIN_MTU)
616 if (!ipv4_should_icmp(skb))
619 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
620 else if (skb->protocol == htons(ETH_P_IPV6)) {
621 if (mtu < IPV6_MIN_MTU)
625 * In theory we should do PMTUD on IPv6 multicast messages but
626 * we don't have an address to send from so just fragment.
628 if (ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST)
631 if (!ipv6_should_icmp(skb))
639 if (old_eh->h_proto == htons(ETH_P_8021Q))
640 eth_hdr_len = VLAN_ETH_HLEN;
642 payload_length = skb->len - eth_hdr_len;
643 if (skb->protocol == htons(ETH_P_IP)) {
644 header_length = sizeof(struct iphdr) + sizeof(struct icmphdr);
645 total_length = min_t(unsigned int, header_length +
646 payload_length, 576);
648 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
650 header_length = sizeof(struct ipv6hdr) +
651 sizeof(struct icmp6hdr);
652 total_length = min_t(unsigned int, header_length +
653 payload_length, IPV6_MIN_MTU);
657 total_length = min(total_length, mutable->mtu);
658 payload_length = total_length - header_length;
660 nskb = dev_alloc_skb(NET_IP_ALIGN + eth_hdr_len + header_length +
665 skb_reserve(nskb, NET_IP_ALIGN);
667 /* Ethernet / VLAN */
668 eh = (struct ethhdr *)skb_put(nskb, eth_hdr_len);
669 memcpy(eh->h_dest, old_eh->h_source, ETH_ALEN);
670 memcpy(eh->h_source, mutable->eth_addr, ETH_ALEN);
671 nskb->protocol = eh->h_proto = old_eh->h_proto;
672 if (old_eh->h_proto == htons(ETH_P_8021Q)) {
673 struct vlan_ethhdr *vh = (struct vlan_ethhdr *)eh;
675 vh->h_vlan_TCI = vlan_eth_hdr(skb)->h_vlan_TCI;
676 vh->h_vlan_encapsulated_proto = skb->protocol;
678 skb_reset_mac_header(nskb);
681 if (skb->protocol == htons(ETH_P_IP))
682 ipv4_build_icmp(skb, nskb, mtu, payload_length);
683 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
685 ipv6_build_icmp(skb, nskb, mtu, payload_length);
689 * Assume that flow based keys are symmetric with respect to input
690 * and output and use the key that we were going to put on the
691 * outgoing packet for the fake received packet. If the keys are
692 * not symmetric then PMTUD needs to be disabled since we won't have
693 * any way of synthesizing packets.
695 if ((mutable->port_config.flags & (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) ==
696 (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION))
697 OVS_CB(nskb)->tun_id = flow_key;
699 compute_ip_summed(nskb, false);
700 vport_receive(vport, nskb);
705 static bool check_mtu(struct sk_buff *skb,
707 const struct tnl_mutable_config *mutable,
708 const struct rtable *rt, __be16 *frag_offp)
713 frag_off = (mutable->port_config.flags & TNL_F_PMTUD) ? htons(IP_DF) : 0;
715 mtu = dst_mtu(&rt_dst(rt))
717 - mutable->tunnel_hlen
718 - (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
722 if (skb->protocol == htons(ETH_P_IP)) {
723 struct iphdr *old_iph = ip_hdr(skb);
725 frag_off |= old_iph->frag_off & htons(IP_DF);
726 mtu = max(mtu, IP_MIN_MTU);
728 if ((old_iph->frag_off & htons(IP_DF)) &&
729 mtu < ntohs(old_iph->tot_len)) {
730 if (tnl_frag_needed(vport, mutable, skb, mtu, OVS_CB(skb)->tun_id))
734 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
735 else if (skb->protocol == htons(ETH_P_IPV6)) {
736 unsigned int packet_length = skb->len - ETH_HLEN
737 - (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
739 mtu = max(mtu, IPV6_MIN_MTU);
741 /* IPv6 requires PMTUD if the packet is above the minimum MTU. */
742 if (packet_length > IPV6_MIN_MTU)
743 frag_off = htons(IP_DF);
745 if (mtu < packet_length) {
746 if (tnl_frag_needed(vport, mutable, skb, mtu, OVS_CB(skb)->tun_id))
752 *frag_offp = frag_off;
760 static void create_tunnel_header(const struct vport *vport,
761 const struct tnl_mutable_config *mutable,
762 const struct rtable *rt, void *header)
764 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
765 struct iphdr *iph = header;
768 iph->ihl = sizeof(struct iphdr) >> 2;
769 iph->frag_off = htons(IP_DF);
770 iph->protocol = tnl_vport->tnl_ops->ipproto;
771 iph->tos = mutable->port_config.tos;
772 iph->daddr = rt->rt_dst;
773 iph->saddr = rt->rt_src;
774 iph->ttl = mutable->port_config.ttl;
776 iph->ttl = dst_metric(&rt_dst(rt), RTAX_HOPLIMIT);
778 tnl_vport->tnl_ops->build_header(vport, mutable, iph + 1);
781 static inline void *get_cached_header(const struct tnl_cache *cache)
783 return (void *)cache + ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN);
786 static inline bool check_cache_valid(const struct tnl_cache *cache,
787 const struct tnl_mutable_config *mutable)
790 #ifdef NEED_CACHE_TIMEOUT
791 time_before(jiffies, cache->expiration) &&
794 atomic_read(&init_net.ipv4.rt_genid) == cache->rt->rt_genid &&
797 rt_dst(cache->rt).hh->hh_lock.sequence == cache->hh_seq &&
799 mutable->seq == cache->mutable_seq &&
800 (!is_internal_dev(rt_dst(cache->rt).dev) ||
801 (cache->flow && !cache->flow->dead));
804 static int cache_cleaner_cb(struct tbl_node *tbl_node, void *aux)
806 struct tnl_vport *tnl_vport = tnl_vport_table_cast(tbl_node);
807 const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable);
808 const struct tnl_cache *cache = rcu_dereference(tnl_vport->cache);
810 if (cache && !check_cache_valid(cache, mutable) &&
811 spin_trylock_bh(&tnl_vport->cache_lock)) {
812 assign_cache_rcu(tnl_vport_to_vport(tnl_vport), NULL);
813 spin_unlock_bh(&tnl_vport->cache_lock);
819 static void cache_cleaner(struct work_struct *work)
821 schedule_cache_cleaner();
824 tbl_foreach(rcu_dereference(port_table), cache_cleaner_cb, NULL);
828 static inline void create_eth_hdr(struct tnl_cache *cache,
829 const struct rtable *rt)
831 void *cache_data = get_cached_header(cache);
832 int hh_len = rt_dst(rt).hh->hh_len;
833 int hh_off = HH_DATA_ALIGN(rt_dst(rt).hh->hh_len) - hh_len;
839 hh_seq = read_seqbegin(&rt_dst(rt).hh->hh_lock);
840 memcpy(cache_data, (void *)rt_dst(rt).hh->hh_data + hh_off, hh_len);
841 } while (read_seqretry(&rt_dst(rt).hh->hh_lock, hh_seq));
843 cache->hh_seq = hh_seq;
845 read_lock_bh(&rt_dst(rt).hh->hh_lock);
846 memcpy(cache_data, (void *)rt_dst(rt).hh->hh_data + hh_off, hh_len);
847 read_unlock_bh(&rt_dst(rt).hh->hh_lock);
851 static struct tnl_cache *build_cache(struct vport *vport,
852 const struct tnl_mutable_config *mutable,
855 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
856 struct tnl_cache *cache;
860 if (!(mutable->port_config.flags & TNL_F_HDR_CACHE))
864 * If there is no entry in the ARP cache or if this device does not
865 * support hard header caching just fall back to the IP stack.
871 * If lock is contended fall back to directly building the header.
872 * We're not going to help performance by sitting here spinning.
874 if (!spin_trylock_bh(&tnl_vport->cache_lock))
877 cache = tnl_vport->cache;
878 if (check_cache_valid(cache, mutable))
883 cache_len = rt_dst(rt).hh->hh_len + mutable->tunnel_hlen;
885 cache = kzalloc(ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN) +
886 cache_len, GFP_ATOMIC);
890 cache->len = cache_len;
892 create_eth_hdr(cache, rt);
893 cache_data = get_cached_header(cache) + rt_dst(rt).hh->hh_len;
895 create_tunnel_header(vport, mutable, rt, cache_data);
897 cache->mutable_seq = mutable->seq;
899 #ifdef NEED_CACHE_TIMEOUT
900 cache->expiration = jiffies + tnl_vport->cache_exp_interval;
903 if (is_internal_dev(rt_dst(rt).dev)) {
904 struct odp_flow_key flow_key;
905 struct tbl_node *flow_node;
911 vport = internal_dev_get_vport(rt_dst(rt).dev);
915 skb = alloc_skb(cache->len, GFP_ATOMIC);
919 __skb_put(skb, cache->len);
920 memcpy(skb->data, get_cached_header(cache), cache->len);
922 err = flow_extract(skb, vport->port_no, &flow_key, &is_frag);
928 flow_node = tbl_lookup(rcu_dereference(vport->dp->table),
929 &flow_key, flow_hash(&flow_key),
932 struct sw_flow *flow = flow_cast(flow_node);
940 assign_cache_rcu(vport, cache);
943 spin_unlock_bh(&tnl_vport->cache_lock);
948 static struct rtable *find_route(struct vport *vport,
949 const struct tnl_mutable_config *mutable,
950 u8 tos, struct tnl_cache **cache)
952 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
953 struct tnl_cache *cur_cache = rcu_dereference(tnl_vport->cache);
958 if (likely(tos == mutable->port_config.tos &&
959 check_cache_valid(cur_cache, mutable))) {
961 return cur_cache->rt;
964 struct flowi fl = { .nl_u = { .ip4_u =
965 { .daddr = mutable->port_config.daddr,
966 .saddr = mutable->port_config.saddr,
968 .proto = tnl_vport->tnl_ops->ipproto };
970 if (unlikely(ip_route_output_key(&init_net, &rt, &fl)))
973 if (likely(tos == mutable->port_config.tos))
974 *cache = build_cache(vport, mutable, rt);
980 static struct sk_buff *check_headroom(struct sk_buff *skb, int headroom)
982 if (skb_headroom(skb) < headroom || skb_header_cloned(skb)) {
983 struct sk_buff *nskb = skb_realloc_headroom(skb, headroom + 16);
984 if (unlikely(!nskb)) {
986 return ERR_PTR(-ENOMEM);
989 set_skb_csum_bits(skb, nskb);
992 skb_set_owner_w(nskb, skb->sk);
1001 static inline bool need_linearize(const struct sk_buff *skb)
1005 if (unlikely(skb_shinfo(skb)->frag_list))
1009 * Generally speaking we should linearize if there are paged frags.
1010 * However, if all of the refcounts are 1 we know nobody else can
1011 * change them from underneath us and we can skip the linearization.
1013 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1014 if (unlikely(page_count(skb_shinfo(skb)->frags[0].page) > 1))
1020 static struct sk_buff *handle_offloads(struct sk_buff *skb,
1021 const struct tnl_mutable_config *mutable,
1022 const struct rtable *rt)
1027 forward_ip_summed(skb);
1029 err = vswitch_skb_checksum_setup(skb);
1033 min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
1034 + mutable->tunnel_hlen;
1036 if (skb_is_gso(skb)) {
1037 struct sk_buff *nskb;
1040 * If we are doing GSO on a pskb it is better to make sure that
1041 * the headroom is correct now. We will only have to copy the
1042 * portion in the linear data area and GSO will preserve
1043 * headroom when it creates the segments. This is particularly
1044 * beneficial on Xen where we get a lot of GSO pskbs.
1045 * Conversely, we avoid copying if it is just to get our own
1046 * writable clone because GSO will do the copy for us.
1048 if (skb_headroom(skb) < min_headroom) {
1049 skb = check_headroom(skb, min_headroom);
1056 nskb = skb_gso_segment(skb, 0);
1059 err = PTR_ERR(nskb);
1065 skb = check_headroom(skb, min_headroom);
1071 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1073 * Pages aren't locked and could change at any time.
1074 * If this happens after we compute the checksum, the
1075 * checksum will be wrong. We linearize now to avoid
1078 if (unlikely(need_linearize(skb))) {
1079 err = __skb_linearize(skb);
1084 err = skb_checksum_help(skb);
1087 } else if (skb->ip_summed == CHECKSUM_COMPLETE)
1088 skb->ip_summed = CHECKSUM_NONE;
1096 return ERR_PTR(err);
1099 static int send_frags(struct sk_buff *skb,
1100 const struct tnl_mutable_config *mutable)
1107 struct sk_buff *next = skb->next;
1108 int frag_len = skb->len - mutable->tunnel_hlen;
1111 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
1113 err = ip_local_out(skb);
1114 if (likely(net_xmit_eval(err) == 0))
1115 sent_len += frag_len;
1128 * There's no point in continuing to send fragments once one has been
1129 * dropped so just free the rest. This may help improve the congestion
1130 * that caused the first packet to be dropped.
1132 tnl_free_linked_skbs(skb);
1136 int tnl_send(struct vport *vport, struct sk_buff *skb)
1138 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1139 const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable);
1141 enum vport_err_type err = VPORT_E_TX_ERROR;
1143 struct dst_entry *unattached_dst = NULL;
1144 struct tnl_cache *cache;
1151 /* Validate the protocol headers before we try to use them. */
1152 if (skb->protocol == htons(ETH_P_8021Q)) {
1153 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
1156 skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
1157 skb_set_network_header(skb, VLAN_ETH_HLEN);
1160 if (skb->protocol == htons(ETH_P_IP)) {
1161 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
1162 + sizeof(struct iphdr))))
1165 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1166 else if (skb->protocol == htons(ETH_P_IPV6)) {
1167 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
1168 + sizeof(struct ipv6hdr))))
1174 if (skb->protocol == htons(ETH_P_IP))
1175 inner_tos = ip_hdr(skb)->tos;
1176 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1177 else if (skb->protocol == htons(ETH_P_IPV6))
1178 inner_tos = ipv6_get_dsfield(ipv6_hdr(skb));
1183 if (mutable->port_config.flags & TNL_F_TOS_INHERIT)
1186 tos = mutable->port_config.tos;
1188 tos = INET_ECN_encapsulate(tos, inner_tos);
1191 rt = find_route(vport, mutable, tos, &cache);
1194 if (unlikely(!cache))
1195 unattached_dst = &rt_dst(rt);
1203 skb = handle_offloads(skb, mutable, rt);
1208 if (unlikely(!check_mtu(skb, vport, mutable, rt, &frag_off))) {
1209 err = VPORT_E_TX_DROPPED;
1214 * If we are over the MTU, allow the IP stack to handle fragmentation.
1215 * Fragmentation is a slow path anyways.
1217 if (unlikely(skb->len + mutable->tunnel_hlen > dst_mtu(&rt_dst(rt)) &&
1219 unattached_dst = &rt_dst(rt);
1220 dst_hold(unattached_dst);
1225 ttl = mutable->port_config.ttl;
1227 ttl = dst_metric(&rt_dst(rt), RTAX_HOPLIMIT);
1229 if (mutable->port_config.flags & TNL_F_TTL_INHERIT) {
1230 if (skb->protocol == htons(ETH_P_IP))
1231 ttl = ip_hdr(skb)->ttl;
1232 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1233 else if (skb->protocol == htons(ETH_P_IPV6))
1234 ttl = ipv6_hdr(skb)->hop_limit;
1240 struct sk_buff *next_skb = skb->next;
1243 if (likely(cache)) {
1244 skb_push(skb, cache->len);
1245 memcpy(skb->data, get_cached_header(cache), cache->len);
1246 skb_reset_mac_header(skb);
1247 skb_set_network_header(skb, rt_dst(rt).hh->hh_len);
1250 skb_push(skb, mutable->tunnel_hlen);
1251 create_tunnel_header(vport, mutable, rt, skb->data);
1252 skb_reset_network_header(skb);
1255 skb_dst_set(skb, dst_clone(unattached_dst));
1257 skb_dst_set(skb, unattached_dst);
1258 unattached_dst = NULL;
1261 skb_set_transport_header(skb, skb_network_offset(skb) + sizeof(struct iphdr));
1266 iph->frag_off = frag_off;
1267 ip_select_ident(iph, &rt_dst(rt), NULL);
1269 skb = tnl_vport->tnl_ops->update_header(vport, mutable, &rt_dst(rt), skb);
1273 if (likely(cache)) {
1274 int orig_len = skb->len - cache->len;
1275 struct vport *cache_vport = internal_dev_get_vport(rt_dst(rt).dev);
1277 skb->protocol = htons(ETH_P_IP);
1278 iph->tot_len = htons(skb->len - skb_network_offset(skb));
1282 OVS_CB(skb)->flow = cache->flow;
1283 compute_ip_summed(skb, true);
1284 vport_receive(cache_vport, skb);
1285 sent_len += orig_len;
1289 skb->dev = rt_dst(rt).dev;
1290 err = dev_queue_xmit(skb);
1292 if (likely(net_xmit_eval(err) == 0))
1293 sent_len += orig_len;
1296 sent_len += send_frags(skb, mutable);
1302 if (unlikely(sent_len == 0))
1303 vport_record_error(vport, VPORT_E_TX_DROPPED);
1308 tnl_free_linked_skbs(skb);
1310 dst_release(unattached_dst);
1311 vport_record_error(vport, err);
1316 static int set_config(const void *config, const struct tnl_ops *tnl_ops,
1317 const struct vport *cur_vport,
1318 struct tnl_mutable_config *mutable)
1320 const struct vport *old_vport;
1321 const struct tnl_mutable_config *old_mutable;
1323 mutable->port_config = *(struct tnl_port_config *)config;
1325 if (mutable->port_config.daddr == 0)
1328 if (mutable->port_config.tos != RT_TOS(mutable->port_config.tos))
1331 mutable->tunnel_hlen = tnl_ops->hdr_len(&mutable->port_config);
1332 if (mutable->tunnel_hlen < 0)
1333 return mutable->tunnel_hlen;
1335 mutable->tunnel_hlen += sizeof(struct iphdr);
1337 mutable->tunnel_type = tnl_ops->tunnel_type;
1338 if (mutable->port_config.flags & TNL_F_IN_KEY_MATCH) {
1339 mutable->tunnel_type |= TNL_T_KEY_MATCH;
1340 mutable->port_config.in_key = 0;
1342 mutable->tunnel_type |= TNL_T_KEY_EXACT;
1344 old_vport = tnl_find_port(mutable->port_config.saddr,
1345 mutable->port_config.daddr,
1346 mutable->port_config.in_key,
1347 mutable->tunnel_type,
1350 if (old_vport && old_vport != cur_vport)
1353 if (mutable->port_config.flags & TNL_F_OUT_KEY_ACTION)
1354 mutable->port_config.out_key = 0;
1359 struct vport *tnl_create(const struct vport_parms *parms,
1360 const struct vport_ops *vport_ops,
1361 const struct tnl_ops *tnl_ops)
1363 struct vport *vport;
1364 struct tnl_vport *tnl_vport;
1365 int initial_frag_id;
1368 vport = vport_alloc(sizeof(struct tnl_vport), vport_ops, parms);
1369 if (IS_ERR(vport)) {
1370 err = PTR_ERR(vport);
1374 tnl_vport = tnl_vport_priv(vport);
1376 strcpy(tnl_vport->name, parms->name);
1377 tnl_vport->tnl_ops = tnl_ops;
1379 tnl_vport->mutable = kzalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL);
1380 if (!tnl_vport->mutable) {
1382 goto error_free_vport;
1385 vport_gen_rand_ether_addr(tnl_vport->mutable->eth_addr);
1386 tnl_vport->mutable->mtu = ETH_DATA_LEN;
1388 get_random_bytes(&initial_frag_id, sizeof(int));
1389 atomic_set(&tnl_vport->frag_id, initial_frag_id);
1391 err = set_config(parms->config, tnl_ops, NULL, tnl_vport->mutable);
1393 goto error_free_mutable;
1395 spin_lock_init(&tnl_vport->cache_lock);
1397 #ifdef NEED_CACHE_TIMEOUT
1398 tnl_vport->cache_exp_interval = MAX_CACHE_EXP -
1399 (net_random() % (MAX_CACHE_EXP / 2));
1402 err = add_port(vport);
1404 goto error_free_mutable;
1409 kfree(tnl_vport->mutable);
1413 return ERR_PTR(err);
1416 int tnl_modify(struct vport *vport, struct odp_port *port)
1418 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1419 struct tnl_mutable_config *mutable;
1422 mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL);
1428 err = set_config(port->config, tnl_vport->tnl_ops, vport, mutable);
1434 err = move_port(vport, mutable);
1446 static void free_port_rcu(struct rcu_head *rcu)
1448 struct tnl_vport *tnl_vport = container_of(rcu, struct tnl_vport, rcu);
1450 spin_lock_bh(&tnl_vport->cache_lock);
1451 free_cache(tnl_vport->cache);
1452 spin_unlock_bh(&tnl_vport->cache_lock);
1454 kfree(tnl_vport->mutable);
1455 vport_free(tnl_vport_to_vport(tnl_vport));
1458 int tnl_destroy(struct vport *vport)
1460 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1461 const struct tnl_mutable_config *old_mutable;
1463 if (vport == tnl_find_port(tnl_vport->mutable->port_config.saddr,
1464 tnl_vport->mutable->port_config.daddr,
1465 tnl_vport->mutable->port_config.in_key,
1466 tnl_vport->mutable->tunnel_type,
1470 call_rcu(&tnl_vport->rcu, free_port_rcu);
1475 int tnl_set_mtu(struct vport *vport, int mtu)
1477 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1478 struct tnl_mutable_config *mutable;
1480 mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL);
1485 assign_config_rcu(vport, mutable);
1490 int tnl_set_addr(struct vport *vport, const unsigned char *addr)
1492 struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1493 struct tnl_mutable_config *mutable;
1495 mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL);
1499 memcpy(mutable->eth_addr, addr, ETH_ALEN);
1500 assign_config_rcu(vport, mutable);
1505 const char *tnl_get_name(const struct vport *vport)
1507 const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1508 return tnl_vport->name;
1511 const unsigned char *tnl_get_addr(const struct vport *vport)
1513 const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1514 return rcu_dereference_rtnl(tnl_vport->mutable)->eth_addr;
1517 int tnl_get_mtu(const struct vport *vport)
1519 const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1520 return rcu_dereference_rtnl(tnl_vport->mutable)->mtu;
1523 void tnl_free_linked_skbs(struct sk_buff *skb)
1529 struct sk_buff *next = skb->next;