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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 | ||
19 | #include <net/dsfield.h> | |
20 | #include <net/dst.h> | |
21 | #include <net/icmp.h> | |
22 | #include <net/inet_ecn.h> | |
23 | #include <net/ip.h> | |
24 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
25 | #include <net/ipv6.h> | |
26 | #endif | |
27 | #include <net/route.h> | |
28 | #include <net/xfrm.h> | |
29 | ||
30 | #include "actions.h" | |
31 | #include "datapath.h" | |
32 | #include "table.h" | |
33 | #include "tunnel.h" | |
34 | #include "vport.h" | |
35 | #include "vport-generic.h" | |
36 | ||
37 | /* Protected by RCU. */ | |
38 | static struct tbl *port_table; | |
39 | ||
40 | /* | |
41 | * These are just used as an optimization: they don't require any kind of | |
42 | * synchronization because we could have just as easily read the value before | |
43 | * the port change happened. | |
44 | */ | |
45 | static unsigned int key_local_remote_ports; | |
46 | static unsigned int key_remote_ports; | |
47 | static unsigned int local_remote_ports; | |
48 | static unsigned int remote_ports; | |
49 | ||
50 | #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36) | |
51 | #define rt_dst(rt) (rt->dst) | |
52 | #else | |
53 | #define rt_dst(rt) (rt->u.dst) | |
54 | #endif | |
55 | ||
56 | static inline struct vport *tnl_vport_to_vport(const struct tnl_vport *tnl_vport) | |
57 | { | |
58 | return vport_from_priv(tnl_vport); | |
59 | } | |
60 | ||
61 | static inline struct tnl_vport *tnl_vport_table_cast(const struct tbl_node *node) | |
62 | { | |
63 | return container_of(node, struct tnl_vport, tbl_node); | |
64 | } | |
65 | ||
66 | /* RCU callback. */ | |
67 | static void free_config(struct rcu_head *rcu) | |
68 | { | |
69 | struct tnl_mutable_config *c = container_of(rcu, struct tnl_mutable_config, rcu); | |
70 | kfree(c); | |
71 | } | |
72 | ||
73 | static void assign_config_rcu(struct vport *vport, | |
74 | struct tnl_mutable_config *new_config) | |
75 | { | |
76 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
77 | struct tnl_mutable_config *old_config; | |
78 | ||
79 | old_config = rcu_dereference(tnl_vport->mutable); | |
80 | rcu_assign_pointer(tnl_vport->mutable, new_config); | |
81 | call_rcu(&old_config->rcu, free_config); | |
82 | } | |
83 | ||
84 | static unsigned int *find_port_pool(const struct tnl_mutable_config *mutable) | |
85 | { | |
86 | if (mutable->port_config.flags & TNL_F_IN_KEY_MATCH) { | |
87 | if (mutable->port_config.saddr) | |
88 | return &local_remote_ports; | |
89 | else | |
90 | return &remote_ports; | |
91 | } else { | |
92 | if (mutable->port_config.saddr) | |
93 | return &key_local_remote_ports; | |
94 | else | |
95 | return &key_remote_ports; | |
96 | } | |
97 | } | |
98 | ||
99 | enum lookup_key { | |
100 | LOOKUP_TUNNEL_TYPE = 0, | |
101 | LOOKUP_SADDR = 1, | |
102 | LOOKUP_DADDR = 2, | |
103 | LOOKUP_KEY = 3, | |
104 | }; | |
105 | ||
106 | struct port_lookup_key { | |
107 | u32 vals[4]; /* Contains enum lookup_key keys. */ | |
108 | const struct tnl_mutable_config *mutable; | |
109 | }; | |
110 | ||
111 | /* | |
112 | * Modifies 'target' to store the rcu_dereferenced pointer that was used to do | |
113 | * the comparision. | |
114 | */ | |
115 | static int port_cmp(const struct tbl_node *node, void *target) | |
116 | { | |
117 | const struct tnl_vport *tnl_vport = tnl_vport_table_cast(node); | |
118 | struct port_lookup_key *lookup = target; | |
119 | ||
120 | lookup->mutable = rcu_dereference(tnl_vport->mutable); | |
121 | ||
122 | return (lookup->mutable->tunnel_type == lookup->vals[LOOKUP_TUNNEL_TYPE]) && | |
123 | lookup->mutable->port_config.daddr == lookup->vals[LOOKUP_DADDR] && | |
124 | lookup->mutable->port_config.in_key == lookup->vals[LOOKUP_KEY] && | |
125 | lookup->mutable->port_config.saddr == lookup->vals[LOOKUP_SADDR]; | |
126 | } | |
127 | ||
128 | static u32 port_hash(struct port_lookup_key *lookup) | |
129 | { | |
130 | return jhash2(lookup->vals, ARRAY_SIZE(lookup->vals), 0); | |
131 | } | |
132 | ||
133 | static int add_port(struct vport *vport) | |
134 | { | |
135 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
136 | struct port_lookup_key lookup; | |
137 | int err; | |
138 | ||
139 | if (!port_table) { | |
140 | struct tbl *new_table; | |
141 | ||
142 | new_table = tbl_create(0); | |
143 | if (!new_table) | |
144 | return -ENOMEM; | |
145 | ||
146 | rcu_assign_pointer(port_table, new_table); | |
147 | ||
148 | } else if (tbl_count(port_table) > tbl_n_buckets(port_table)) { | |
149 | struct tbl *old_table = port_table; | |
150 | struct tbl *new_table; | |
151 | ||
152 | new_table = tbl_expand(old_table); | |
153 | if (IS_ERR(new_table)) | |
154 | return PTR_ERR(new_table); | |
155 | ||
156 | rcu_assign_pointer(port_table, new_table); | |
157 | tbl_deferred_destroy(old_table, NULL); | |
158 | } | |
159 | ||
160 | lookup.vals[LOOKUP_SADDR] = tnl_vport->mutable->port_config.saddr; | |
161 | lookup.vals[LOOKUP_DADDR] = tnl_vport->mutable->port_config.daddr; | |
162 | lookup.vals[LOOKUP_KEY] = tnl_vport->mutable->port_config.in_key; | |
163 | lookup.vals[LOOKUP_TUNNEL_TYPE] = tnl_vport->mutable->tunnel_type; | |
164 | ||
165 | err = tbl_insert(port_table, &tnl_vport->tbl_node, port_hash(&lookup)); | |
166 | if (err) | |
167 | return err; | |
168 | ||
169 | (*find_port_pool(tnl_vport->mutable))++; | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
174 | static int del_port(struct vport *vport) | |
175 | { | |
176 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
177 | int err; | |
178 | ||
179 | err = tbl_remove(port_table, &tnl_vport->tbl_node); | |
180 | if (err) | |
181 | return err; | |
182 | ||
183 | (*find_port_pool(tnl_vport->mutable))--; | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
188 | struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be32 key, | |
189 | int tunnel_type, | |
190 | const struct tnl_mutable_config **mutable) | |
191 | { | |
192 | struct port_lookup_key lookup; | |
193 | struct tbl *table = rcu_dereference(port_table); | |
194 | struct tbl_node *tbl_node; | |
195 | ||
196 | if (!table) | |
197 | return NULL; | |
198 | ||
199 | lookup.vals[LOOKUP_SADDR] = saddr; | |
200 | lookup.vals[LOOKUP_DADDR] = daddr; | |
201 | ||
202 | if (tunnel_type & TNL_T_KEY_EXACT) { | |
203 | lookup.vals[LOOKUP_KEY] = key; | |
204 | lookup.vals[LOOKUP_TUNNEL_TYPE] = tunnel_type & ~TNL_T_KEY_MATCH; | |
205 | ||
206 | if (key_local_remote_ports) { | |
207 | tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp); | |
208 | if (tbl_node) | |
209 | goto found; | |
210 | } | |
211 | ||
212 | if (key_remote_ports) { | |
213 | lookup.vals[LOOKUP_SADDR] = 0; | |
214 | ||
215 | tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp); | |
216 | if (tbl_node) | |
217 | goto found; | |
218 | ||
219 | lookup.vals[LOOKUP_SADDR] = saddr; | |
220 | } | |
221 | } | |
222 | ||
223 | if (tunnel_type & TNL_T_KEY_MATCH) { | |
224 | lookup.vals[LOOKUP_KEY] = 0; | |
225 | lookup.vals[LOOKUP_TUNNEL_TYPE] = tunnel_type & ~TNL_T_KEY_EXACT; | |
226 | ||
227 | if (local_remote_ports) { | |
228 | tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp); | |
229 | if (tbl_node) | |
230 | goto found; | |
231 | } | |
232 | ||
233 | if (remote_ports) { | |
234 | lookup.vals[LOOKUP_SADDR] = 0; | |
235 | ||
236 | tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp); | |
237 | if (tbl_node) | |
238 | goto found; | |
239 | } | |
240 | } | |
241 | ||
242 | return NULL; | |
243 | ||
244 | found: | |
245 | *mutable = lookup.mutable; | |
246 | return tnl_vport_to_vport(tnl_vport_table_cast(tbl_node)); | |
247 | } | |
248 | ||
249 | static bool check_ipv4_address(__be32 addr) | |
250 | { | |
251 | if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr) | |
252 | || ipv4_is_loopback(addr) || ipv4_is_zeronet(addr)) | |
253 | return false; | |
254 | ||
255 | return true; | |
256 | } | |
257 | ||
258 | static bool ipv4_should_icmp(struct sk_buff *skb) | |
259 | { | |
260 | struct iphdr *old_iph = ip_hdr(skb); | |
261 | ||
262 | /* Don't respond to L2 broadcast. */ | |
263 | if (is_multicast_ether_addr(eth_hdr(skb)->h_dest)) | |
264 | return false; | |
265 | ||
266 | /* Don't respond to L3 broadcast or invalid addresses. */ | |
267 | if (!check_ipv4_address(old_iph->daddr) || | |
268 | !check_ipv4_address(old_iph->saddr)) | |
269 | return false; | |
270 | ||
271 | /* Only respond to the first fragment. */ | |
272 | if (old_iph->frag_off & htons(IP_OFFSET)) | |
273 | return false; | |
274 | ||
275 | /* Don't respond to ICMP error messages. */ | |
276 | if (old_iph->protocol == IPPROTO_ICMP) { | |
277 | u8 icmp_type, *icmp_typep; | |
278 | ||
279 | icmp_typep = skb_header_pointer(skb, (u8 *)old_iph + | |
280 | (old_iph->ihl << 2) + | |
281 | offsetof(struct icmphdr, type) - | |
282 | skb->data, sizeof(icmp_type), | |
283 | &icmp_type); | |
284 | ||
285 | if (!icmp_typep) | |
286 | return false; | |
287 | ||
288 | if (*icmp_typep > NR_ICMP_TYPES | |
289 | || (*icmp_typep <= ICMP_PARAMETERPROB | |
290 | && *icmp_typep != ICMP_ECHOREPLY | |
291 | && *icmp_typep != ICMP_ECHO)) | |
292 | return false; | |
293 | } | |
294 | ||
295 | return true; | |
296 | } | |
297 | ||
298 | static void ipv4_build_icmp(struct sk_buff *skb, struct sk_buff *nskb, | |
299 | unsigned int mtu, unsigned int payload_length) | |
300 | { | |
301 | struct iphdr *iph, *old_iph = ip_hdr(skb); | |
302 | struct icmphdr *icmph; | |
303 | u8 *payload; | |
304 | ||
305 | iph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr)); | |
306 | icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr)); | |
307 | payload = skb_put(nskb, payload_length); | |
308 | ||
309 | /* IP */ | |
310 | iph->version = 4; | |
311 | iph->ihl = sizeof(struct iphdr) >> 2; | |
312 | iph->tos = (old_iph->tos & IPTOS_TOS_MASK) | | |
313 | IPTOS_PREC_INTERNETCONTROL; | |
314 | iph->tot_len = htons(sizeof(struct iphdr) | |
315 | + sizeof(struct icmphdr) | |
316 | + payload_length); | |
317 | get_random_bytes(&iph->id, sizeof(iph->id)); | |
318 | iph->frag_off = 0; | |
319 | iph->ttl = IPDEFTTL; | |
320 | iph->protocol = IPPROTO_ICMP; | |
321 | iph->daddr = old_iph->saddr; | |
322 | iph->saddr = old_iph->daddr; | |
323 | ||
324 | ip_send_check(iph); | |
325 | ||
326 | /* ICMP */ | |
327 | icmph->type = ICMP_DEST_UNREACH; | |
328 | icmph->code = ICMP_FRAG_NEEDED; | |
329 | icmph->un.gateway = htonl(mtu); | |
330 | icmph->checksum = 0; | |
331 | ||
332 | nskb->csum = csum_partial((u8 *)icmph, sizeof(struct icmphdr), 0); | |
333 | nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_iph - skb->data, | |
334 | payload, payload_length, | |
335 | nskb->csum); | |
336 | icmph->checksum = csum_fold(nskb->csum); | |
337 | } | |
338 | ||
339 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
340 | static bool ipv6_should_icmp(struct sk_buff *skb) | |
341 | { | |
342 | struct ipv6hdr *old_ipv6h = ipv6_hdr(skb); | |
343 | int addr_type; | |
344 | int payload_off = (u8 *)(old_ipv6h + 1) - skb->data; | |
345 | u8 nexthdr = ipv6_hdr(skb)->nexthdr; | |
346 | ||
347 | /* Check source address is valid. */ | |
348 | addr_type = ipv6_addr_type(&old_ipv6h->saddr); | |
349 | if (addr_type & IPV6_ADDR_MULTICAST || addr_type == IPV6_ADDR_ANY) | |
350 | return false; | |
351 | ||
352 | /* Don't reply to unspecified addresses. */ | |
353 | if (ipv6_addr_type(&old_ipv6h->daddr) == IPV6_ADDR_ANY) | |
354 | return false; | |
355 | ||
356 | /* Don't respond to ICMP error messages. */ | |
357 | payload_off = ipv6_skip_exthdr(skb, payload_off, &nexthdr); | |
358 | if (payload_off < 0) | |
359 | return false; | |
360 | ||
361 | if (nexthdr == NEXTHDR_ICMP) { | |
362 | u8 icmp_type, *icmp_typep; | |
363 | ||
364 | icmp_typep = skb_header_pointer(skb, payload_off + | |
365 | offsetof(struct icmp6hdr, | |
366 | icmp6_type), | |
367 | sizeof(icmp_type), &icmp_type); | |
368 | ||
369 | if (!icmp_typep || !(*icmp_typep & ICMPV6_INFOMSG_MASK)) | |
370 | return false; | |
371 | } | |
372 | ||
373 | return true; | |
374 | } | |
375 | ||
376 | static void ipv6_build_icmp(struct sk_buff *skb, struct sk_buff *nskb, | |
377 | unsigned int mtu, unsigned int payload_length) | |
378 | { | |
379 | struct ipv6hdr *ipv6h, *old_ipv6h = ipv6_hdr(skb); | |
380 | struct icmp6hdr *icmp6h; | |
381 | u8 *payload; | |
382 | ||
383 | ipv6h = (struct ipv6hdr *)skb_put(nskb, sizeof(struct ipv6hdr)); | |
384 | icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr)); | |
385 | payload = skb_put(nskb, payload_length); | |
386 | ||
387 | /* IPv6 */ | |
388 | ipv6h->version = 6; | |
389 | ipv6h->priority = 0; | |
390 | memset(&ipv6h->flow_lbl, 0, sizeof(ipv6h->flow_lbl)); | |
391 | ipv6h->payload_len = htons(sizeof(struct icmp6hdr) | |
392 | + payload_length); | |
393 | ipv6h->nexthdr = NEXTHDR_ICMP; | |
394 | ipv6h->hop_limit = IPV6_DEFAULT_HOPLIMIT; | |
395 | ipv6_addr_copy(&ipv6h->daddr, &old_ipv6h->saddr); | |
396 | ipv6_addr_copy(&ipv6h->saddr, &old_ipv6h->daddr); | |
397 | ||
398 | /* ICMPv6 */ | |
399 | icmp6h->icmp6_type = ICMPV6_PKT_TOOBIG; | |
400 | icmp6h->icmp6_code = 0; | |
401 | icmp6h->icmp6_cksum = 0; | |
402 | icmp6h->icmp6_mtu = htonl(mtu); | |
403 | ||
404 | nskb->csum = csum_partial((u8 *)icmp6h, sizeof(struct icmp6hdr), 0); | |
405 | nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_ipv6h - skb->data, | |
406 | payload, payload_length, | |
407 | nskb->csum); | |
408 | icmp6h->icmp6_cksum = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, | |
409 | sizeof(struct icmp6hdr) | |
410 | + payload_length, | |
411 | ipv6h->nexthdr, nskb->csum); | |
412 | } | |
413 | #endif /* IPv6 */ | |
414 | ||
415 | bool tnl_frag_needed(struct vport *vport, const struct tnl_mutable_config *mutable, | |
416 | struct sk_buff *skb, unsigned int mtu, __be32 flow_key) | |
417 | { | |
418 | unsigned int eth_hdr_len = ETH_HLEN; | |
419 | unsigned int total_length = 0, header_length = 0, payload_length; | |
420 | struct ethhdr *eh, *old_eh = eth_hdr(skb); | |
421 | struct sk_buff *nskb; | |
422 | ||
423 | /* Sanity check */ | |
424 | if (skb->protocol == htons(ETH_P_IP)) { | |
425 | if (mtu < IP_MIN_MTU) | |
426 | return false; | |
427 | ||
428 | if (!ipv4_should_icmp(skb)) | |
429 | return true; | |
430 | } | |
431 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
432 | else if (skb->protocol == htons(ETH_P_IPV6)) { | |
433 | if (mtu < IPV6_MIN_MTU) | |
434 | return false; | |
435 | ||
436 | /* | |
437 | * In theory we should do PMTUD on IPv6 multicast messages but | |
438 | * we don't have an address to send from so just fragment. | |
439 | */ | |
440 | if (ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST) | |
441 | return false; | |
442 | ||
443 | if (!ipv6_should_icmp(skb)) | |
444 | return true; | |
445 | } | |
446 | #endif | |
447 | else | |
448 | return false; | |
449 | ||
450 | /* Allocate */ | |
451 | if (old_eh->h_proto == htons(ETH_P_8021Q)) | |
452 | eth_hdr_len = VLAN_ETH_HLEN; | |
453 | ||
454 | payload_length = skb->len - eth_hdr_len; | |
455 | if (skb->protocol == htons(ETH_P_IP)) { | |
456 | header_length = sizeof(struct iphdr) + sizeof(struct icmphdr); | |
457 | total_length = min_t(unsigned int, header_length + | |
458 | payload_length, 576); | |
459 | } | |
460 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
461 | else { | |
462 | header_length = sizeof(struct ipv6hdr) + | |
463 | sizeof(struct icmp6hdr); | |
464 | total_length = min_t(unsigned int, header_length + | |
465 | payload_length, IPV6_MIN_MTU); | |
466 | } | |
467 | #endif | |
468 | ||
469 | total_length = min(total_length, mutable->mtu); | |
470 | payload_length = total_length - header_length; | |
471 | ||
472 | nskb = dev_alloc_skb(NET_IP_ALIGN + eth_hdr_len + header_length + | |
473 | payload_length); | |
474 | if (!nskb) | |
475 | return false; | |
476 | ||
477 | skb_reserve(nskb, NET_IP_ALIGN); | |
478 | ||
479 | /* Ethernet / VLAN */ | |
480 | eh = (struct ethhdr *)skb_put(nskb, eth_hdr_len); | |
481 | memcpy(eh->h_dest, old_eh->h_source, ETH_ALEN); | |
482 | memcpy(eh->h_source, mutable->eth_addr, ETH_ALEN); | |
483 | nskb->protocol = eh->h_proto = old_eh->h_proto; | |
484 | if (old_eh->h_proto == htons(ETH_P_8021Q)) { | |
485 | struct vlan_ethhdr *vh = (struct vlan_ethhdr *)eh; | |
486 | ||
487 | vh->h_vlan_TCI = vlan_eth_hdr(skb)->h_vlan_TCI; | |
488 | vh->h_vlan_encapsulated_proto = skb->protocol; | |
489 | } | |
490 | skb_reset_mac_header(nskb); | |
491 | ||
492 | /* Protocol */ | |
493 | if (skb->protocol == htons(ETH_P_IP)) | |
494 | ipv4_build_icmp(skb, nskb, mtu, payload_length); | |
495 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
496 | else | |
497 | ipv6_build_icmp(skb, nskb, mtu, payload_length); | |
498 | #endif | |
499 | ||
500 | /* | |
501 | * Assume that flow based keys are symmetric with respect to input | |
502 | * and output and use the key that we were going to put on the | |
503 | * outgoing packet for the fake received packet. If the keys are | |
504 | * not symmetric then PMTUD needs to be disabled since we won't have | |
505 | * any way of synthesizing packets. | |
506 | */ | |
507 | if ((mutable->port_config.flags & (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) == | |
508 | (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) | |
509 | OVS_CB(nskb)->tun_id = flow_key; | |
510 | ||
511 | compute_ip_summed(nskb, false); | |
512 | vport_receive(vport, nskb); | |
513 | ||
514 | return true; | |
515 | } | |
516 | ||
517 | static struct sk_buff *check_headroom(struct sk_buff *skb, int headroom) | |
518 | { | |
519 | if (skb_headroom(skb) < headroom || skb_header_cloned(skb)) { | |
520 | struct sk_buff *nskb = skb_realloc_headroom(skb, headroom + 16); | |
521 | if (unlikely(!nskb)) { | |
522 | kfree_skb(skb); | |
523 | return ERR_PTR(-ENOMEM); | |
524 | } | |
525 | ||
526 | set_skb_csum_bits(skb, nskb); | |
527 | ||
528 | if (skb->sk) | |
529 | skb_set_owner_w(nskb, skb->sk); | |
530 | ||
531 | dev_kfree_skb(skb); | |
532 | return nskb; | |
533 | } | |
534 | ||
535 | return skb; | |
536 | } | |
537 | ||
538 | static inline u8 ecn_encapsulate(u8 tos, struct sk_buff *skb) | |
539 | { | |
540 | u8 inner; | |
541 | ||
542 | if (skb->protocol == htons(ETH_P_IP)) | |
543 | inner = ((struct iphdr *)skb_network_header(skb))->tos; | |
544 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
545 | else if (skb->protocol == htons(ETH_P_IPV6)) | |
546 | inner = ipv6_get_dsfield((struct ipv6hdr *)skb_network_header(skb)); | |
547 | #endif | |
548 | else | |
549 | inner = 0; | |
550 | ||
551 | return INET_ECN_encapsulate(tos, inner); | |
552 | } | |
553 | ||
554 | static inline void ecn_decapsulate(struct sk_buff *skb) | |
555 | { | |
556 | u8 tos = ip_hdr(skb)->tos; | |
557 | ||
558 | if (INET_ECN_is_ce(tos)) { | |
559 | __be16 protocol = skb->protocol; | |
560 | unsigned int nw_header = skb_network_header(skb) - skb->data; | |
561 | ||
562 | if (skb->protocol == htons(ETH_P_8021Q)) { | |
563 | if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN))) | |
564 | return; | |
565 | ||
566 | protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto; | |
567 | nw_header += VLAN_HLEN; | |
568 | } | |
569 | ||
570 | if (protocol == htons(ETH_P_IP)) { | |
571 | if (unlikely(!pskb_may_pull(skb, nw_header | |
572 | + sizeof(struct iphdr)))) | |
573 | return; | |
574 | ||
575 | IP_ECN_set_ce((struct iphdr *)(nw_header + skb->data)); | |
576 | } | |
577 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
578 | else if (protocol == htons(ETH_P_IPV6)) { | |
579 | if (unlikely(!pskb_may_pull(skb, nw_header | |
580 | + sizeof(struct ipv6hdr)))) | |
581 | return; | |
582 | ||
583 | IP6_ECN_set_ce((struct ipv6hdr *)(nw_header | |
584 | + skb->data)); | |
585 | } | |
586 | #endif | |
587 | } | |
588 | } | |
589 | ||
590 | static struct sk_buff *handle_gso(struct sk_buff *skb) | |
591 | { | |
592 | if (skb_is_gso(skb)) { | |
593 | struct sk_buff *nskb = skb_gso_segment(skb, 0); | |
594 | ||
595 | dev_kfree_skb(skb); | |
596 | return nskb; | |
597 | } | |
598 | ||
599 | return skb; | |
600 | } | |
601 | ||
602 | static int handle_csum_offload(struct sk_buff *skb) | |
603 | { | |
604 | if (skb->ip_summed == CHECKSUM_PARTIAL) | |
605 | return skb_checksum_help(skb); | |
606 | else { | |
607 | skb->ip_summed = CHECKSUM_NONE; | |
608 | return 0; | |
609 | } | |
610 | } | |
611 | ||
612 | /* Called with rcu_read_lock. */ | |
613 | void tnl_rcv(struct vport *vport, struct sk_buff *skb) | |
614 | { | |
615 | skb->pkt_type = PACKET_HOST; | |
616 | skb->protocol = eth_type_trans(skb, skb->dev); | |
617 | ||
618 | skb_dst_drop(skb); | |
619 | nf_reset(skb); | |
620 | secpath_reset(skb); | |
621 | skb_reset_network_header(skb); | |
622 | ||
623 | ecn_decapsulate(skb); | |
624 | ||
625 | skb_push(skb, ETH_HLEN); | |
626 | compute_ip_summed(skb, false); | |
627 | ||
628 | vport_receive(vport, skb); | |
629 | } | |
630 | ||
631 | static int build_packet(struct vport *vport, const struct tnl_mutable_config *mutable, | |
632 | struct iphdr *iph, struct rtable *rt, int max_headroom, | |
633 | int mtu, struct sk_buff *skb) | |
634 | { | |
635 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
636 | int err; | |
637 | struct iphdr *new_iph; | |
638 | int orig_len = skb->len; | |
639 | __be16 frag_off = iph->frag_off; | |
640 | ||
641 | skb = check_headroom(skb, max_headroom); | |
642 | if (unlikely(IS_ERR(skb))) | |
643 | goto error; | |
644 | ||
645 | err = handle_csum_offload(skb); | |
646 | if (unlikely(err)) | |
647 | goto error_free; | |
648 | ||
649 | if (skb->protocol == htons(ETH_P_IP)) { | |
650 | struct iphdr *old_iph = ip_hdr(skb); | |
651 | ||
652 | if ((old_iph->frag_off & htons(IP_DF)) && | |
653 | mtu < ntohs(old_iph->tot_len)) { | |
654 | if (tnl_frag_needed(vport, mutable, skb, mtu, OVS_CB(skb)->tun_id)) | |
655 | goto error_free; | |
656 | } | |
657 | ||
658 | } | |
659 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
660 | else if (skb->protocol == htons(ETH_P_IPV6)) { | |
661 | unsigned int packet_length = skb->len - ETH_HLEN | |
662 | - (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q) ? VLAN_HLEN : 0); | |
663 | ||
664 | /* IPv6 requires PMTUD if the packet is above the minimum MTU. */ | |
665 | if (packet_length > IPV6_MIN_MTU) | |
666 | frag_off = htons(IP_DF); | |
667 | ||
668 | if (mtu < packet_length) { | |
669 | if (tnl_frag_needed(vport, mutable, skb, mtu, OVS_CB(skb)->tun_id)) | |
670 | goto error_free; | |
671 | } | |
672 | } | |
673 | #endif | |
674 | ||
675 | new_iph = (struct iphdr *)skb_push(skb, mutable->tunnel_hlen); | |
676 | skb_reset_network_header(skb); | |
677 | skb_set_transport_header(skb, sizeof(struct iphdr)); | |
678 | ||
679 | memcpy(new_iph, iph, sizeof(struct iphdr)); | |
680 | new_iph->frag_off = frag_off; | |
681 | ip_select_ident(new_iph, &rt_dst(rt), NULL); | |
682 | ||
683 | tnl_vport->tnl_ops->build_header(skb, vport, mutable); | |
684 | ||
685 | /* Allow our local IP stack to fragment the outer packet even if the | |
686 | * DF bit is set as a last resort. */ | |
687 | skb->local_df = 1; | |
688 | ||
689 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
690 | IPCB(skb)->flags = 0; | |
691 | ||
692 | err = ip_local_out(skb); | |
693 | if (likely(net_xmit_eval(err) == 0)) | |
694 | return orig_len; | |
695 | else { | |
696 | vport_record_error(vport, VPORT_E_TX_ERROR); | |
697 | return 0; | |
698 | } | |
699 | ||
700 | error_free: | |
701 | kfree_skb(skb); | |
702 | error: | |
703 | vport_record_error(vport, VPORT_E_TX_DROPPED); | |
704 | ||
705 | return 0; | |
706 | } | |
707 | ||
708 | int tnl_send(struct vport *vport, struct sk_buff *skb) | |
709 | { | |
710 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
711 | const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable); | |
712 | ||
713 | struct iphdr *old_iph; | |
714 | int orig_len; | |
715 | struct iphdr iph; | |
716 | struct rtable *rt; | |
717 | int max_headroom; | |
718 | int mtu; | |
719 | ||
720 | /* Validate the protocol headers before we try to use them. */ | |
721 | if (skb->protocol == htons(ETH_P_8021Q)) { | |
722 | if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN))) | |
723 | goto error_free; | |
724 | ||
725 | skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto; | |
726 | skb_set_network_header(skb, VLAN_ETH_HLEN); | |
727 | } | |
728 | ||
729 | if (skb->protocol == htons(ETH_P_IP)) { | |
730 | if (unlikely(!pskb_may_pull(skb, skb_network_header(skb) | |
731 | + sizeof(struct iphdr) - skb->data))) | |
732 | skb->protocol = 0; | |
733 | } | |
734 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
735 | else if (skb->protocol == htons(ETH_P_IPV6)) { | |
736 | if (unlikely(!pskb_may_pull(skb, skb_network_header(skb) | |
737 | + sizeof(struct ipv6hdr) - skb->data))) | |
738 | skb->protocol = 0; | |
739 | } | |
740 | #endif | |
741 | old_iph = ip_hdr(skb); | |
742 | ||
743 | iph.tos = mutable->port_config.tos; | |
744 | if (mutable->port_config.flags & TNL_F_TOS_INHERIT) { | |
745 | if (skb->protocol == htons(ETH_P_IP)) | |
746 | iph.tos = old_iph->tos; | |
747 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
748 | else if (skb->protocol == htons(ETH_P_IPV6)) | |
749 | iph.tos = ipv6_get_dsfield(ipv6_hdr(skb)); | |
750 | #endif | |
751 | } | |
752 | iph.tos = ecn_encapsulate(iph.tos, skb); | |
753 | ||
754 | { | |
755 | struct flowi fl = { .nl_u = { .ip4_u = | |
756 | { .daddr = mutable->port_config.daddr, | |
757 | .saddr = mutable->port_config.saddr, | |
758 | .tos = RT_TOS(iph.tos) } }, | |
759 | .proto = tnl_vport->tnl_ops->ipproto }; | |
760 | ||
761 | if (unlikely(ip_route_output_key(&init_net, &rt, &fl))) | |
762 | goto error_free; | |
763 | } | |
764 | ||
765 | iph.ttl = mutable->port_config.ttl; | |
766 | if (mutable->port_config.flags & TNL_F_TTL_INHERIT) { | |
767 | if (skb->protocol == htons(ETH_P_IP)) | |
768 | iph.ttl = old_iph->ttl; | |
769 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
770 | else if (skb->protocol == htons(ETH_P_IPV6)) | |
771 | iph.ttl = ipv6_hdr(skb)->hop_limit; | |
772 | #endif | |
773 | } | |
774 | if (!iph.ttl) | |
775 | iph.ttl = dst_metric(&rt_dst(rt), RTAX_HOPLIMIT); | |
776 | ||
777 | iph.frag_off = (mutable->port_config.flags & TNL_F_PMTUD) ? htons(IP_DF) : 0; | |
778 | if (iph.frag_off) | |
779 | mtu = dst_mtu(&rt_dst(rt)) | |
780 | - ETH_HLEN | |
781 | - mutable->tunnel_hlen | |
782 | - (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q) ? VLAN_HLEN : 0); | |
783 | else | |
784 | mtu = mutable->mtu; | |
785 | ||
786 | if (skb->protocol == htons(ETH_P_IP)) { | |
787 | iph.frag_off |= old_iph->frag_off & htons(IP_DF); | |
788 | mtu = max(mtu, IP_MIN_MTU); | |
789 | } | |
790 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
791 | else if (skb->protocol == htons(ETH_P_IPV6)) | |
792 | mtu = max(mtu, IPV6_MIN_MTU); | |
793 | #endif | |
794 | ||
795 | iph.version = 4; | |
796 | iph.ihl = sizeof(struct iphdr) >> 2; | |
797 | iph.protocol = tnl_vport->tnl_ops->ipproto; | |
798 | iph.daddr = rt->rt_dst; | |
799 | iph.saddr = rt->rt_src; | |
800 | ||
801 | nf_reset(skb); | |
802 | secpath_reset(skb); | |
803 | skb_dst_drop(skb); | |
804 | skb_dst_set(skb, &rt_dst(rt)); | |
805 | ||
806 | /* | |
807 | * If we are doing GSO on a pskb it is better to make sure that the | |
808 | * headroom is correct now. We will only have to copy the portion in | |
809 | * the linear data area and GSO will preserve headroom when it creates | |
810 | * the segments. This is particularly beneficial on Xen where we get | |
811 | * lots of GSO pskbs. Conversely, we delay copying if it is just to | |
812 | * get our own writable clone because GSO may do the copy for us. | |
813 | */ | |
814 | max_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len | |
815 | + mutable->tunnel_hlen; | |
816 | ||
817 | if (skb_headroom(skb) < max_headroom) { | |
818 | skb = check_headroom(skb, max_headroom); | |
819 | if (unlikely(IS_ERR(skb))) { | |
820 | vport_record_error(vport, VPORT_E_TX_DROPPED); | |
821 | goto error; | |
822 | } | |
823 | } | |
824 | ||
825 | forward_ip_summed(skb); | |
826 | ||
827 | if (unlikely(vswitch_skb_checksum_setup(skb))) | |
828 | goto error_free; | |
829 | ||
830 | skb = handle_gso(skb); | |
831 | if (unlikely(IS_ERR(skb))) { | |
832 | vport_record_error(vport, VPORT_E_TX_DROPPED); | |
833 | goto error; | |
834 | } | |
835 | ||
836 | /* | |
837 | * Process GSO segments. Try to do any work for the entire packet that | |
838 | * doesn't involve actually writing to it before this point. | |
839 | */ | |
840 | orig_len = 0; | |
841 | do { | |
842 | struct sk_buff *next_skb = skb->next; | |
843 | skb->next = NULL; | |
844 | ||
845 | orig_len += build_packet(vport, mutable, &iph, rt, max_headroom, mtu, skb); | |
846 | ||
847 | skb = next_skb; | |
848 | } while (skb); | |
849 | ||
850 | return orig_len; | |
851 | ||
852 | error_free: | |
853 | kfree_skb(skb); | |
854 | vport_record_error(vport, VPORT_E_TX_ERROR); | |
855 | error: | |
856 | return 0; | |
857 | } | |
858 | ||
859 | int tnl_init(void) | |
860 | { | |
861 | return 0; | |
862 | } | |
863 | ||
864 | void tnl_exit(void) | |
865 | { | |
866 | tbl_destroy(port_table, NULL); | |
867 | port_table = NULL; | |
868 | } | |
869 | ||
870 | static int set_config(const void __user *uconfig, const struct tnl_ops *tnl_ops, | |
871 | const struct vport *cur_vport, | |
872 | struct tnl_mutable_config *mutable) | |
873 | { | |
874 | const struct vport *old_vport; | |
875 | const struct tnl_mutable_config *old_mutable; | |
876 | ||
877 | if (copy_from_user(&mutable->port_config, uconfig, sizeof(struct tnl_port_config))) | |
878 | return -EFAULT; | |
879 | ||
880 | mutable->tunnel_hlen = tnl_ops->hdr_len(&mutable->port_config); | |
881 | if (mutable->tunnel_hlen < 0) | |
882 | return mutable->tunnel_hlen; | |
883 | ||
884 | mutable->tunnel_hlen += sizeof(struct iphdr); | |
885 | ||
886 | if (mutable->port_config.daddr == 0) | |
887 | return -EINVAL; | |
888 | ||
889 | mutable->tunnel_type = tnl_ops->tunnel_type; | |
890 | if (mutable->port_config.flags & TNL_F_IN_KEY_MATCH) { | |
891 | mutable->tunnel_type |= TNL_T_KEY_MATCH; | |
892 | mutable->port_config.in_key = 0; | |
893 | } else | |
894 | mutable->tunnel_type |= TNL_T_KEY_EXACT; | |
895 | ||
896 | old_vport = tnl_find_port(mutable->port_config.saddr, | |
897 | mutable->port_config.daddr, | |
898 | mutable->port_config.in_key, | |
899 | mutable->tunnel_type, | |
900 | &old_mutable); | |
901 | ||
902 | if (old_vport && old_vport != cur_vport) | |
903 | return -EEXIST; | |
904 | ||
905 | if (mutable->port_config.flags & TNL_F_OUT_KEY_ACTION) | |
906 | mutable->port_config.out_key = 0; | |
907 | ||
908 | return 0; | |
909 | } | |
910 | ||
911 | struct vport *tnl_create(const char *name, const void __user *config, | |
912 | const struct vport_ops *vport_ops, | |
913 | const struct tnl_ops *tnl_ops) | |
914 | { | |
915 | struct vport *vport; | |
916 | struct tnl_vport *tnl_vport; | |
917 | int err; | |
918 | ||
919 | vport = vport_alloc(sizeof(struct tnl_vport), vport_ops); | |
920 | if (IS_ERR(vport)) { | |
921 | err = PTR_ERR(vport); | |
922 | goto error; | |
923 | } | |
924 | ||
925 | tnl_vport = tnl_vport_priv(vport); | |
926 | ||
927 | strcpy(tnl_vport->name, name); | |
928 | tnl_vport->tnl_ops = tnl_ops; | |
929 | ||
930 | tnl_vport->mutable = kmalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL); | |
931 | if (!tnl_vport->mutable) { | |
932 | err = -ENOMEM; | |
933 | goto error_free_vport; | |
934 | } | |
935 | ||
936 | vport_gen_rand_ether_addr(tnl_vport->mutable->eth_addr); | |
937 | tnl_vport->mutable->mtu = ETH_DATA_LEN; | |
938 | ||
939 | err = set_config(config, tnl_ops, NULL, tnl_vport->mutable); | |
940 | if (err) | |
941 | goto error_free_mutable; | |
942 | ||
943 | err = add_port(vport); | |
944 | if (err) | |
945 | goto error_free_mutable; | |
946 | ||
947 | return vport; | |
948 | ||
949 | error_free_mutable: | |
950 | kfree(tnl_vport->mutable); | |
951 | error_free_vport: | |
952 | vport_free(vport); | |
953 | error: | |
954 | return ERR_PTR(err); | |
955 | } | |
956 | ||
957 | int tnl_modify(struct vport *vport, const void __user *config) | |
958 | { | |
959 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
960 | struct tnl_mutable_config *mutable; | |
961 | int err; | |
962 | bool update_hash = false; | |
963 | ||
964 | mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL); | |
965 | if (!mutable) { | |
966 | err = -ENOMEM; | |
967 | goto error; | |
968 | } | |
969 | ||
970 | err = set_config(config, tnl_vport->tnl_ops, vport, mutable); | |
971 | if (err) | |
972 | goto error_free; | |
973 | ||
974 | /* | |
975 | * Only remove the port from the hash table if something that would | |
976 | * affect the lookup has changed. | |
977 | */ | |
978 | if (tnl_vport->mutable->port_config.saddr != mutable->port_config.saddr || | |
979 | tnl_vport->mutable->port_config.daddr != mutable->port_config.daddr || | |
980 | tnl_vport->mutable->port_config.in_key != mutable->port_config.in_key || | |
981 | (tnl_vport->mutable->port_config.flags & TNL_F_IN_KEY_MATCH) != | |
982 | (mutable->port_config.flags & TNL_F_IN_KEY_MATCH)) | |
983 | update_hash = true; | |
984 | ||
985 | ||
986 | /* | |
987 | * This update is not atomic but the lookup uses the config, which | |
988 | * serves as an inherent double check. | |
989 | */ | |
990 | if (update_hash) { | |
991 | err = del_port(vport); | |
992 | if (err) | |
993 | goto error_free; | |
994 | } | |
995 | ||
996 | assign_config_rcu(vport, mutable); | |
997 | ||
998 | if (update_hash) { | |
999 | err = add_port(vport); | |
1000 | if (err) | |
1001 | goto error_free; | |
1002 | } | |
1003 | ||
1004 | return 0; | |
1005 | ||
1006 | error_free: | |
1007 | kfree(mutable); | |
1008 | error: | |
1009 | return err; | |
1010 | } | |
1011 | ||
1012 | static void free_port(struct rcu_head *rcu) | |
1013 | { | |
1014 | struct tnl_vport *tnl_vport = container_of(rcu, struct tnl_vport, rcu); | |
1015 | ||
1016 | kfree(tnl_vport->mutable); | |
1017 | vport_free(tnl_vport_to_vport(tnl_vport)); | |
1018 | } | |
1019 | ||
1020 | int tnl_destroy(struct vport *vport) | |
1021 | { | |
1022 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
1023 | const struct tnl_mutable_config *old_mutable; | |
1024 | ||
1025 | if (vport == tnl_find_port(tnl_vport->mutable->port_config.saddr, | |
1026 | tnl_vport->mutable->port_config.daddr, | |
1027 | tnl_vport->mutable->port_config.in_key, | |
1028 | tnl_vport->mutable->tunnel_type, | |
1029 | &old_mutable)) | |
1030 | del_port(vport); | |
1031 | ||
1032 | call_rcu(&tnl_vport->rcu, free_port); | |
1033 | ||
1034 | return 0; | |
1035 | } | |
1036 | ||
1037 | int tnl_set_mtu(struct vport *vport, int mtu) | |
1038 | { | |
1039 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
1040 | struct tnl_mutable_config *mutable; | |
1041 | ||
1042 | mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL); | |
1043 | if (!mutable) | |
1044 | return -ENOMEM; | |
1045 | ||
1046 | mutable->mtu = mtu; | |
1047 | assign_config_rcu(vport, mutable); | |
1048 | ||
1049 | return 0; | |
1050 | } | |
1051 | ||
1052 | int tnl_set_addr(struct vport *vport, const unsigned char *addr) | |
1053 | { | |
1054 | struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
1055 | struct tnl_mutable_config *mutable; | |
1056 | ||
1057 | mutable = kmemdup(tnl_vport->mutable, sizeof(struct tnl_mutable_config), GFP_KERNEL); | |
1058 | if (!mutable) | |
1059 | return -ENOMEM; | |
1060 | ||
1061 | memcpy(mutable->eth_addr, addr, ETH_ALEN); | |
1062 | assign_config_rcu(vport, mutable); | |
1063 | ||
1064 | return 0; | |
1065 | } | |
1066 | ||
1067 | ||
1068 | const char *tnl_get_name(const struct vport *vport) | |
1069 | { | |
1070 | const struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
1071 | return tnl_vport->name; | |
1072 | } | |
1073 | ||
1074 | const unsigned char *tnl_get_addr(const struct vport *vport) | |
1075 | { | |
1076 | const struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
1077 | return rcu_dereference(tnl_vport->mutable)->eth_addr; | |
1078 | } | |
1079 | ||
1080 | int tnl_get_mtu(const struct vport *vport) | |
1081 | { | |
1082 | const struct tnl_vport *tnl_vport = tnl_vport_priv(vport); | |
1083 | return rcu_dereference(tnl_vport->mutable)->mtu; | |
1084 | } |