1 /*
2  * Copyright (c) 2007-2011 Nicira Networks.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of version 2 of the GNU General Public
6  * License as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16  * 02110-1301, USA
17  */
18 
19 #include "flow.h"
20 #include "datapath.h"
21 #include <linux/uaccess.h>
22 #include <linux/netdevice.h>
23 #include <linux/etherdevice.h>
24 #include <linux/if_ether.h>
25 #include <linux/if_vlan.h>
26 #include <net/llc_pdu.h>
27 #include <linux/kernel.h>
28 #include <linux/jhash.h>
29 #include <linux/jiffies.h>
30 #include <linux/llc.h>
31 #include <linux/module.h>
32 #include <linux/in.h>
33 #include <linux/rcupdate.h>
34 #include <linux/if_arp.h>
35 #include <linux/ip.h>
36 #include <linux/ipv6.h>
37 #include <linux/tcp.h>
38 #include <linux/udp.h>
39 #include <linux/icmp.h>
40 #include <linux/icmpv6.h>
41 #include <linux/rculist.h>
42 #include <net/ip.h>
43 #include <net/ipv6.h>
44 #include <net/ndisc.h>
45 
46 static struct kmem_cache *flow_cache;
47 
check_header(struct sk_buff * skb,int len)48 static int check_header(struct sk_buff *skb, int len)
49 {
50 	if (unlikely(skb->len < len))
51 		return -EINVAL;
52 	if (unlikely(!pskb_may_pull(skb, len)))
53 		return -ENOMEM;
54 	return 0;
55 }
56 
arphdr_ok(struct sk_buff * skb)57 static bool arphdr_ok(struct sk_buff *skb)
58 {
59 	return pskb_may_pull(skb, skb_network_offset(skb) +
60 				  sizeof(struct arp_eth_header));
61 }
62 
check_iphdr(struct sk_buff * skb)63 static int check_iphdr(struct sk_buff *skb)
64 {
65 	unsigned int nh_ofs = skb_network_offset(skb);
66 	unsigned int ip_len;
67 	int err;
68 
69 	err = check_header(skb, nh_ofs + sizeof(struct iphdr));
70 	if (unlikely(err))
71 		return err;
72 
73 	ip_len = ip_hdrlen(skb);
74 	if (unlikely(ip_len < sizeof(struct iphdr) ||
75 		     skb->len < nh_ofs + ip_len))
76 		return -EINVAL;
77 
78 	skb_set_transport_header(skb, nh_ofs + ip_len);
79 	return 0;
80 }
81 
tcphdr_ok(struct sk_buff * skb)82 static bool tcphdr_ok(struct sk_buff *skb)
83 {
84 	int th_ofs = skb_transport_offset(skb);
85 	int tcp_len;
86 
87 	if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
88 		return false;
89 
90 	tcp_len = tcp_hdrlen(skb);
91 	if (unlikely(tcp_len < sizeof(struct tcphdr) ||
92 		     skb->len < th_ofs + tcp_len))
93 		return false;
94 
95 	return true;
96 }
97 
udphdr_ok(struct sk_buff * skb)98 static bool udphdr_ok(struct sk_buff *skb)
99 {
100 	return pskb_may_pull(skb, skb_transport_offset(skb) +
101 				  sizeof(struct udphdr));
102 }
103 
icmphdr_ok(struct sk_buff * skb)104 static bool icmphdr_ok(struct sk_buff *skb)
105 {
106 	return pskb_may_pull(skb, skb_transport_offset(skb) +
107 				  sizeof(struct icmphdr));
108 }
109 
ovs_flow_used_time(unsigned long flow_jiffies)110 u64 ovs_flow_used_time(unsigned long flow_jiffies)
111 {
112 	struct timespec cur_ts;
113 	u64 cur_ms, idle_ms;
114 
115 	ktime_get_ts(&cur_ts);
116 	idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
117 	cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC +
118 		 cur_ts.tv_nsec / NSEC_PER_MSEC;
119 
120 	return cur_ms - idle_ms;
121 }
122 
123 #define SW_FLOW_KEY_OFFSET(field)		\
124 	(offsetof(struct sw_flow_key, field) +	\
125 	 FIELD_SIZEOF(struct sw_flow_key, field))
126 
parse_ipv6hdr(struct sk_buff * skb,struct sw_flow_key * key,int * key_lenp)127 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key,
128 			 int *key_lenp)
129 {
130 	unsigned int nh_ofs = skb_network_offset(skb);
131 	unsigned int nh_len;
132 	int payload_ofs;
133 	struct ipv6hdr *nh;
134 	uint8_t nexthdr;
135 	__be16 frag_off;
136 	int err;
137 
138 	*key_lenp = SW_FLOW_KEY_OFFSET(ipv6.label);
139 
140 	err = check_header(skb, nh_ofs + sizeof(*nh));
141 	if (unlikely(err))
142 		return err;
143 
144 	nh = ipv6_hdr(skb);
145 	nexthdr = nh->nexthdr;
146 	payload_ofs = (u8 *)(nh + 1) - skb->data;
147 
148 	key->ip.proto = NEXTHDR_NONE;
149 	key->ip.tos = ipv6_get_dsfield(nh);
150 	key->ip.ttl = nh->hop_limit;
151 	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
152 	key->ipv6.addr.src = nh->saddr;
153 	key->ipv6.addr.dst = nh->daddr;
154 
155 	payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);
156 	if (unlikely(payload_ofs < 0))
157 		return -EINVAL;
158 
159 	if (frag_off) {
160 		if (frag_off & htons(~0x7))
161 			key->ip.frag = OVS_FRAG_TYPE_LATER;
162 		else
163 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
164 	}
165 
166 	nh_len = payload_ofs - nh_ofs;
167 	skb_set_transport_header(skb, nh_ofs + nh_len);
168 	key->ip.proto = nexthdr;
169 	return nh_len;
170 }
171 
icmp6hdr_ok(struct sk_buff * skb)172 static bool icmp6hdr_ok(struct sk_buff *skb)
173 {
174 	return pskb_may_pull(skb, skb_transport_offset(skb) +
175 				  sizeof(struct icmp6hdr));
176 }
177 
178 #define TCP_FLAGS_OFFSET 13
179 #define TCP_FLAG_MASK 0x3f
180 
ovs_flow_used(struct sw_flow * flow,struct sk_buff * skb)181 void ovs_flow_used(struct sw_flow *flow, struct sk_buff *skb)
182 {
183 	u8 tcp_flags = 0;
184 
185 	if (flow->key.eth.type == htons(ETH_P_IP) &&
186 	    flow->key.ip.proto == IPPROTO_TCP &&
187 	    likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) {
188 		u8 *tcp = (u8 *)tcp_hdr(skb);
189 		tcp_flags = *(tcp + TCP_FLAGS_OFFSET) & TCP_FLAG_MASK;
190 	}
191 
192 	spin_lock(&flow->lock);
193 	flow->used = jiffies;
194 	flow->packet_count++;
195 	flow->byte_count += skb->len;
196 	flow->tcp_flags |= tcp_flags;
197 	spin_unlock(&flow->lock);
198 }
199 
ovs_flow_actions_alloc(const struct nlattr * actions)200 struct sw_flow_actions *ovs_flow_actions_alloc(const struct nlattr *actions)
201 {
202 	int actions_len = nla_len(actions);
203 	struct sw_flow_actions *sfa;
204 
205 	/* At least DP_MAX_PORTS actions are required to be able to flood a
206 	 * packet to every port.  Factor of 2 allows for setting VLAN tags,
207 	 * etc. */
208 	if (actions_len > 2 * DP_MAX_PORTS * nla_total_size(4))
209 		return ERR_PTR(-EINVAL);
210 
211 	sfa = kmalloc(sizeof(*sfa) + actions_len, GFP_KERNEL);
212 	if (!sfa)
213 		return ERR_PTR(-ENOMEM);
214 
215 	sfa->actions_len = actions_len;
216 	memcpy(sfa->actions, nla_data(actions), actions_len);
217 	return sfa;
218 }
219 
ovs_flow_alloc(void)220 struct sw_flow *ovs_flow_alloc(void)
221 {
222 	struct sw_flow *flow;
223 
224 	flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
225 	if (!flow)
226 		return ERR_PTR(-ENOMEM);
227 
228 	spin_lock_init(&flow->lock);
229 	flow->sf_acts = NULL;
230 
231 	return flow;
232 }
233 
find_bucket(struct flow_table * table,u32 hash)234 static struct hlist_head *find_bucket(struct flow_table *table, u32 hash)
235 {
236 	hash = jhash_1word(hash, table->hash_seed);
237 	return flex_array_get(table->buckets,
238 				(hash & (table->n_buckets - 1)));
239 }
240 
alloc_buckets(unsigned int n_buckets)241 static struct flex_array *alloc_buckets(unsigned int n_buckets)
242 {
243 	struct flex_array *buckets;
244 	int i, err;
245 
246 	buckets = flex_array_alloc(sizeof(struct hlist_head *),
247 				   n_buckets, GFP_KERNEL);
248 	if (!buckets)
249 		return NULL;
250 
251 	err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
252 	if (err) {
253 		flex_array_free(buckets);
254 		return NULL;
255 	}
256 
257 	for (i = 0; i < n_buckets; i++)
258 		INIT_HLIST_HEAD((struct hlist_head *)
259 					flex_array_get(buckets, i));
260 
261 	return buckets;
262 }
263 
free_buckets(struct flex_array * buckets)264 static void free_buckets(struct flex_array *buckets)
265 {
266 	flex_array_free(buckets);
267 }
268 
ovs_flow_tbl_alloc(int new_size)269 struct flow_table *ovs_flow_tbl_alloc(int new_size)
270 {
271 	struct flow_table *table = kmalloc(sizeof(*table), GFP_KERNEL);
272 
273 	if (!table)
274 		return NULL;
275 
276 	table->buckets = alloc_buckets(new_size);
277 
278 	if (!table->buckets) {
279 		kfree(table);
280 		return NULL;
281 	}
282 	table->n_buckets = new_size;
283 	table->count = 0;
284 	table->node_ver = 0;
285 	table->keep_flows = false;
286 	get_random_bytes(&table->hash_seed, sizeof(u32));
287 
288 	return table;
289 }
290 
ovs_flow_tbl_destroy(struct flow_table * table)291 void ovs_flow_tbl_destroy(struct flow_table *table)
292 {
293 	int i;
294 
295 	if (!table)
296 		return;
297 
298 	if (table->keep_flows)
299 		goto skip_flows;
300 
301 	for (i = 0; i < table->n_buckets; i++) {
302 		struct sw_flow *flow;
303 		struct hlist_head *head = flex_array_get(table->buckets, i);
304 		struct hlist_node *node, *n;
305 		int ver = table->node_ver;
306 
307 		hlist_for_each_entry_safe(flow, node, n, head, hash_node[ver]) {
308 			hlist_del_rcu(&flow->hash_node[ver]);
309 			ovs_flow_free(flow);
310 		}
311 	}
312 
313 skip_flows:
314 	free_buckets(table->buckets);
315 	kfree(table);
316 }
317 
flow_tbl_destroy_rcu_cb(struct rcu_head * rcu)318 static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
319 {
320 	struct flow_table *table = container_of(rcu, struct flow_table, rcu);
321 
322 	ovs_flow_tbl_destroy(table);
323 }
324 
ovs_flow_tbl_deferred_destroy(struct flow_table * table)325 void ovs_flow_tbl_deferred_destroy(struct flow_table *table)
326 {
327 	if (!table)
328 		return;
329 
330 	call_rcu(&table->rcu, flow_tbl_destroy_rcu_cb);
331 }
332 
ovs_flow_tbl_next(struct flow_table * table,u32 * bucket,u32 * last)333 struct sw_flow *ovs_flow_tbl_next(struct flow_table *table, u32 *bucket, u32 *last)
334 {
335 	struct sw_flow *flow;
336 	struct hlist_head *head;
337 	struct hlist_node *n;
338 	int ver;
339 	int i;
340 
341 	ver = table->node_ver;
342 	while (*bucket < table->n_buckets) {
343 		i = 0;
344 		head = flex_array_get(table->buckets, *bucket);
345 		hlist_for_each_entry_rcu(flow, n, head, hash_node[ver]) {
346 			if (i < *last) {
347 				i++;
348 				continue;
349 			}
350 			*last = i + 1;
351 			return flow;
352 		}
353 		(*bucket)++;
354 		*last = 0;
355 	}
356 
357 	return NULL;
358 }
359 
flow_table_copy_flows(struct flow_table * old,struct flow_table * new)360 static void flow_table_copy_flows(struct flow_table *old, struct flow_table *new)
361 {
362 	int old_ver;
363 	int i;
364 
365 	old_ver = old->node_ver;
366 	new->node_ver = !old_ver;
367 
368 	/* Insert in new table. */
369 	for (i = 0; i < old->n_buckets; i++) {
370 		struct sw_flow *flow;
371 		struct hlist_head *head;
372 		struct hlist_node *n;
373 
374 		head = flex_array_get(old->buckets, i);
375 
376 		hlist_for_each_entry(flow, n, head, hash_node[old_ver])
377 			ovs_flow_tbl_insert(new, flow);
378 	}
379 	old->keep_flows = true;
380 }
381 
__flow_tbl_rehash(struct flow_table * table,int n_buckets)382 static struct flow_table *__flow_tbl_rehash(struct flow_table *table, int n_buckets)
383 {
384 	struct flow_table *new_table;
385 
386 	new_table = ovs_flow_tbl_alloc(n_buckets);
387 	if (!new_table)
388 		return ERR_PTR(-ENOMEM);
389 
390 	flow_table_copy_flows(table, new_table);
391 
392 	return new_table;
393 }
394 
ovs_flow_tbl_rehash(struct flow_table * table)395 struct flow_table *ovs_flow_tbl_rehash(struct flow_table *table)
396 {
397 	return __flow_tbl_rehash(table, table->n_buckets);
398 }
399 
ovs_flow_tbl_expand(struct flow_table * table)400 struct flow_table *ovs_flow_tbl_expand(struct flow_table *table)
401 {
402 	return __flow_tbl_rehash(table, table->n_buckets * 2);
403 }
404 
ovs_flow_free(struct sw_flow * flow)405 void ovs_flow_free(struct sw_flow *flow)
406 {
407 	if (unlikely(!flow))
408 		return;
409 
410 	kfree((struct sf_flow_acts __force *)flow->sf_acts);
411 	kmem_cache_free(flow_cache, flow);
412 }
413 
414 /* RCU callback used by ovs_flow_deferred_free. */
rcu_free_flow_callback(struct rcu_head * rcu)415 static void rcu_free_flow_callback(struct rcu_head *rcu)
416 {
417 	struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
418 
419 	ovs_flow_free(flow);
420 }
421 
422 /* Schedules 'flow' to be freed after the next RCU grace period.
423  * The caller must hold rcu_read_lock for this to be sensible. */
ovs_flow_deferred_free(struct sw_flow * flow)424 void ovs_flow_deferred_free(struct sw_flow *flow)
425 {
426 	call_rcu(&flow->rcu, rcu_free_flow_callback);
427 }
428 
429 /* RCU callback used by ovs_flow_deferred_free_acts. */
rcu_free_acts_callback(struct rcu_head * rcu)430 static void rcu_free_acts_callback(struct rcu_head *rcu)
431 {
432 	struct sw_flow_actions *sf_acts = container_of(rcu,
433 			struct sw_flow_actions, rcu);
434 	kfree(sf_acts);
435 }
436 
437 /* Schedules 'sf_acts' to be freed after the next RCU grace period.
438  * The caller must hold rcu_read_lock for this to be sensible. */
ovs_flow_deferred_free_acts(struct sw_flow_actions * sf_acts)439 void ovs_flow_deferred_free_acts(struct sw_flow_actions *sf_acts)
440 {
441 	call_rcu(&sf_acts->rcu, rcu_free_acts_callback);
442 }
443 
parse_vlan(struct sk_buff * skb,struct sw_flow_key * key)444 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
445 {
446 	struct qtag_prefix {
447 		__be16 eth_type; /* ETH_P_8021Q */
448 		__be16 tci;
449 	};
450 	struct qtag_prefix *qp;
451 
452 	if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16)))
453 		return 0;
454 
455 	if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
456 					 sizeof(__be16))))
457 		return -ENOMEM;
458 
459 	qp = (struct qtag_prefix *) skb->data;
460 	key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
461 	__skb_pull(skb, sizeof(struct qtag_prefix));
462 
463 	return 0;
464 }
465 
parse_ethertype(struct sk_buff * skb)466 static __be16 parse_ethertype(struct sk_buff *skb)
467 {
468 	struct llc_snap_hdr {
469 		u8  dsap;  /* Always 0xAA */
470 		u8  ssap;  /* Always 0xAA */
471 		u8  ctrl;
472 		u8  oui[3];
473 		__be16 ethertype;
474 	};
475 	struct llc_snap_hdr *llc;
476 	__be16 proto;
477 
478 	proto = *(__be16 *) skb->data;
479 	__skb_pull(skb, sizeof(__be16));
480 
481 	if (ntohs(proto) >= 1536)
482 		return proto;
483 
484 	if (skb->len < sizeof(struct llc_snap_hdr))
485 		return htons(ETH_P_802_2);
486 
487 	if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
488 		return htons(0);
489 
490 	llc = (struct llc_snap_hdr *) skb->data;
491 	if (llc->dsap != LLC_SAP_SNAP ||
492 	    llc->ssap != LLC_SAP_SNAP ||
493 	    (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
494 		return htons(ETH_P_802_2);
495 
496 	__skb_pull(skb, sizeof(struct llc_snap_hdr));
497 	return llc->ethertype;
498 }
499 
parse_icmpv6(struct sk_buff * skb,struct sw_flow_key * key,int * key_lenp,int nh_len)500 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
501 			int *key_lenp, int nh_len)
502 {
503 	struct icmp6hdr *icmp = icmp6_hdr(skb);
504 	int error = 0;
505 	int key_len;
506 
507 	/* The ICMPv6 type and code fields use the 16-bit transport port
508 	 * fields, so we need to store them in 16-bit network byte order.
509 	 */
510 	key->ipv6.tp.src = htons(icmp->icmp6_type);
511 	key->ipv6.tp.dst = htons(icmp->icmp6_code);
512 	key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
513 
514 	if (icmp->icmp6_code == 0 &&
515 	    (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
516 	     icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
517 		int icmp_len = skb->len - skb_transport_offset(skb);
518 		struct nd_msg *nd;
519 		int offset;
520 
521 		key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
522 
523 		/* In order to process neighbor discovery options, we need the
524 		 * entire packet.
525 		 */
526 		if (unlikely(icmp_len < sizeof(*nd)))
527 			goto out;
528 		if (unlikely(skb_linearize(skb))) {
529 			error = -ENOMEM;
530 			goto out;
531 		}
532 
533 		nd = (struct nd_msg *)skb_transport_header(skb);
534 		key->ipv6.nd.target = nd->target;
535 		key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
536 
537 		icmp_len -= sizeof(*nd);
538 		offset = 0;
539 		while (icmp_len >= 8) {
540 			struct nd_opt_hdr *nd_opt =
541 				 (struct nd_opt_hdr *)(nd->opt + offset);
542 			int opt_len = nd_opt->nd_opt_len * 8;
543 
544 			if (unlikely(!opt_len || opt_len > icmp_len))
545 				goto invalid;
546 
547 			/* Store the link layer address if the appropriate
548 			 * option is provided.  It is considered an error if
549 			 * the same link layer option is specified twice.
550 			 */
551 			if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
552 			    && opt_len == 8) {
553 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
554 					goto invalid;
555 				memcpy(key->ipv6.nd.sll,
556 				    &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
557 			} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
558 				   && opt_len == 8) {
559 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
560 					goto invalid;
561 				memcpy(key->ipv6.nd.tll,
562 				    &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
563 			}
564 
565 			icmp_len -= opt_len;
566 			offset += opt_len;
567 		}
568 	}
569 
570 	goto out;
571 
572 invalid:
573 	memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
574 	memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
575 	memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
576 
577 out:
578 	*key_lenp = key_len;
579 	return error;
580 }
581 
582 /**
583  * ovs_flow_extract - extracts a flow key from an Ethernet frame.
584  * @skb: sk_buff that contains the frame, with skb->data pointing to the
585  * Ethernet header
586  * @in_port: port number on which @skb was received.
587  * @key: output flow key
588  * @key_lenp: length of output flow key
589  *
590  * The caller must ensure that skb->len >= ETH_HLEN.
591  *
592  * Returns 0 if successful, otherwise a negative errno value.
593  *
594  * Initializes @skb header pointers as follows:
595  *
596  *    - skb->mac_header: the Ethernet header.
597  *
598  *    - skb->network_header: just past the Ethernet header, or just past the
599  *      VLAN header, to the first byte of the Ethernet payload.
600  *
601  *    - skb->transport_header: If key->dl_type is ETH_P_IP or ETH_P_IPV6
602  *      on output, then just past the IP header, if one is present and
603  *      of a correct length, otherwise the same as skb->network_header.
604  *      For other key->dl_type values it is left untouched.
605  */
ovs_flow_extract(struct sk_buff * skb,u16 in_port,struct sw_flow_key * key,int * key_lenp)606 int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key,
607 		 int *key_lenp)
608 {
609 	int error = 0;
610 	int key_len = SW_FLOW_KEY_OFFSET(eth);
611 	struct ethhdr *eth;
612 
613 	memset(key, 0, sizeof(*key));
614 
615 	key->phy.priority = skb->priority;
616 	key->phy.in_port = in_port;
617 
618 	skb_reset_mac_header(skb);
619 
620 	/* Link layer.  We are guaranteed to have at least the 14 byte Ethernet
621 	 * header in the linear data area.
622 	 */
623 	eth = eth_hdr(skb);
624 	memcpy(key->eth.src, eth->h_source, ETH_ALEN);
625 	memcpy(key->eth.dst, eth->h_dest, ETH_ALEN);
626 
627 	__skb_pull(skb, 2 * ETH_ALEN);
628 
629 	if (vlan_tx_tag_present(skb))
630 		key->eth.tci = htons(skb->vlan_tci);
631 	else if (eth->h_proto == htons(ETH_P_8021Q))
632 		if (unlikely(parse_vlan(skb, key)))
633 			return -ENOMEM;
634 
635 	key->eth.type = parse_ethertype(skb);
636 	if (unlikely(key->eth.type == htons(0)))
637 		return -ENOMEM;
638 
639 	skb_reset_network_header(skb);
640 	__skb_push(skb, skb->data - skb_mac_header(skb));
641 
642 	/* Network layer. */
643 	if (key->eth.type == htons(ETH_P_IP)) {
644 		struct iphdr *nh;
645 		__be16 offset;
646 
647 		key_len = SW_FLOW_KEY_OFFSET(ipv4.addr);
648 
649 		error = check_iphdr(skb);
650 		if (unlikely(error)) {
651 			if (error == -EINVAL) {
652 				skb->transport_header = skb->network_header;
653 				error = 0;
654 			}
655 			goto out;
656 		}
657 
658 		nh = ip_hdr(skb);
659 		key->ipv4.addr.src = nh->saddr;
660 		key->ipv4.addr.dst = nh->daddr;
661 
662 		key->ip.proto = nh->protocol;
663 		key->ip.tos = nh->tos;
664 		key->ip.ttl = nh->ttl;
665 
666 		offset = nh->frag_off & htons(IP_OFFSET);
667 		if (offset) {
668 			key->ip.frag = OVS_FRAG_TYPE_LATER;
669 			goto out;
670 		}
671 		if (nh->frag_off & htons(IP_MF) ||
672 			 skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
673 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
674 
675 		/* Transport layer. */
676 		if (key->ip.proto == IPPROTO_TCP) {
677 			key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
678 			if (tcphdr_ok(skb)) {
679 				struct tcphdr *tcp = tcp_hdr(skb);
680 				key->ipv4.tp.src = tcp->source;
681 				key->ipv4.tp.dst = tcp->dest;
682 			}
683 		} else if (key->ip.proto == IPPROTO_UDP) {
684 			key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
685 			if (udphdr_ok(skb)) {
686 				struct udphdr *udp = udp_hdr(skb);
687 				key->ipv4.tp.src = udp->source;
688 				key->ipv4.tp.dst = udp->dest;
689 			}
690 		} else if (key->ip.proto == IPPROTO_ICMP) {
691 			key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
692 			if (icmphdr_ok(skb)) {
693 				struct icmphdr *icmp = icmp_hdr(skb);
694 				/* The ICMP type and code fields use the 16-bit
695 				 * transport port fields, so we need to store
696 				 * them in 16-bit network byte order. */
697 				key->ipv4.tp.src = htons(icmp->type);
698 				key->ipv4.tp.dst = htons(icmp->code);
699 			}
700 		}
701 
702 	} else if (key->eth.type == htons(ETH_P_ARP) && arphdr_ok(skb)) {
703 		struct arp_eth_header *arp;
704 
705 		arp = (struct arp_eth_header *)skb_network_header(skb);
706 
707 		if (arp->ar_hrd == htons(ARPHRD_ETHER)
708 				&& arp->ar_pro == htons(ETH_P_IP)
709 				&& arp->ar_hln == ETH_ALEN
710 				&& arp->ar_pln == 4) {
711 
712 			/* We only match on the lower 8 bits of the opcode. */
713 			if (ntohs(arp->ar_op) <= 0xff)
714 				key->ip.proto = ntohs(arp->ar_op);
715 
716 			if (key->ip.proto == ARPOP_REQUEST
717 					|| key->ip.proto == ARPOP_REPLY) {
718 				memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
719 				memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
720 				memcpy(key->ipv4.arp.sha, arp->ar_sha, ETH_ALEN);
721 				memcpy(key->ipv4.arp.tha, arp->ar_tha, ETH_ALEN);
722 				key_len = SW_FLOW_KEY_OFFSET(ipv4.arp);
723 			}
724 		}
725 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
726 		int nh_len;             /* IPv6 Header + Extensions */
727 
728 		nh_len = parse_ipv6hdr(skb, key, &key_len);
729 		if (unlikely(nh_len < 0)) {
730 			if (nh_len == -EINVAL)
731 				skb->transport_header = skb->network_header;
732 			else
733 				error = nh_len;
734 			goto out;
735 		}
736 
737 		if (key->ip.frag == OVS_FRAG_TYPE_LATER)
738 			goto out;
739 		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
740 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
741 
742 		/* Transport layer. */
743 		if (key->ip.proto == NEXTHDR_TCP) {
744 			key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
745 			if (tcphdr_ok(skb)) {
746 				struct tcphdr *tcp = tcp_hdr(skb);
747 				key->ipv6.tp.src = tcp->source;
748 				key->ipv6.tp.dst = tcp->dest;
749 			}
750 		} else if (key->ip.proto == NEXTHDR_UDP) {
751 			key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
752 			if (udphdr_ok(skb)) {
753 				struct udphdr *udp = udp_hdr(skb);
754 				key->ipv6.tp.src = udp->source;
755 				key->ipv6.tp.dst = udp->dest;
756 			}
757 		} else if (key->ip.proto == NEXTHDR_ICMP) {
758 			key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
759 			if (icmp6hdr_ok(skb)) {
760 				error = parse_icmpv6(skb, key, &key_len, nh_len);
761 				if (error < 0)
762 					goto out;
763 			}
764 		}
765 	}
766 
767 out:
768 	*key_lenp = key_len;
769 	return error;
770 }
771 
ovs_flow_hash(const struct sw_flow_key * key,int key_len)772 u32 ovs_flow_hash(const struct sw_flow_key *key, int key_len)
773 {
774 	return jhash2((u32 *)key, DIV_ROUND_UP(key_len, sizeof(u32)), 0);
775 }
776 
ovs_flow_tbl_lookup(struct flow_table * table,struct sw_flow_key * key,int key_len)777 struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *table,
778 				struct sw_flow_key *key, int key_len)
779 {
780 	struct sw_flow *flow;
781 	struct hlist_node *n;
782 	struct hlist_head *head;
783 	u32 hash;
784 
785 	hash = ovs_flow_hash(key, key_len);
786 
787 	head = find_bucket(table, hash);
788 	hlist_for_each_entry_rcu(flow, n, head, hash_node[table->node_ver]) {
789 
790 		if (flow->hash == hash &&
791 		    !memcmp(&flow->key, key, key_len)) {
792 			return flow;
793 		}
794 	}
795 	return NULL;
796 }
797 
ovs_flow_tbl_insert(struct flow_table * table,struct sw_flow * flow)798 void ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow)
799 {
800 	struct hlist_head *head;
801 
802 	head = find_bucket(table, flow->hash);
803 	hlist_add_head_rcu(&flow->hash_node[table->node_ver], head);
804 	table->count++;
805 }
806 
ovs_flow_tbl_remove(struct flow_table * table,struct sw_flow * flow)807 void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
808 {
809 	hlist_del_rcu(&flow->hash_node[table->node_ver]);
810 	table->count--;
811 	BUG_ON(table->count < 0);
812 }
813 
814 /* The size of the argument for each %OVS_KEY_ATTR_* Netlink attribute.  */
815 const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
816 	[OVS_KEY_ATTR_ENCAP] = -1,
817 	[OVS_KEY_ATTR_PRIORITY] = sizeof(u32),
818 	[OVS_KEY_ATTR_IN_PORT] = sizeof(u32),
819 	[OVS_KEY_ATTR_ETHERNET] = sizeof(struct ovs_key_ethernet),
820 	[OVS_KEY_ATTR_VLAN] = sizeof(__be16),
821 	[OVS_KEY_ATTR_ETHERTYPE] = sizeof(__be16),
822 	[OVS_KEY_ATTR_IPV4] = sizeof(struct ovs_key_ipv4),
823 	[OVS_KEY_ATTR_IPV6] = sizeof(struct ovs_key_ipv6),
824 	[OVS_KEY_ATTR_TCP] = sizeof(struct ovs_key_tcp),
825 	[OVS_KEY_ATTR_UDP] = sizeof(struct ovs_key_udp),
826 	[OVS_KEY_ATTR_ICMP] = sizeof(struct ovs_key_icmp),
827 	[OVS_KEY_ATTR_ICMPV6] = sizeof(struct ovs_key_icmpv6),
828 	[OVS_KEY_ATTR_ARP] = sizeof(struct ovs_key_arp),
829 	[OVS_KEY_ATTR_ND] = sizeof(struct ovs_key_nd),
830 };
831 
ipv4_flow_from_nlattrs(struct sw_flow_key * swkey,int * key_len,const struct nlattr * a[],u32 * attrs)832 static int ipv4_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_len,
833 				  const struct nlattr *a[], u32 *attrs)
834 {
835 	const struct ovs_key_icmp *icmp_key;
836 	const struct ovs_key_tcp *tcp_key;
837 	const struct ovs_key_udp *udp_key;
838 
839 	switch (swkey->ip.proto) {
840 	case IPPROTO_TCP:
841 		if (!(*attrs & (1 << OVS_KEY_ATTR_TCP)))
842 			return -EINVAL;
843 		*attrs &= ~(1 << OVS_KEY_ATTR_TCP);
844 
845 		*key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
846 		tcp_key = nla_data(a[OVS_KEY_ATTR_TCP]);
847 		swkey->ipv4.tp.src = tcp_key->tcp_src;
848 		swkey->ipv4.tp.dst = tcp_key->tcp_dst;
849 		break;
850 
851 	case IPPROTO_UDP:
852 		if (!(*attrs & (1 << OVS_KEY_ATTR_UDP)))
853 			return -EINVAL;
854 		*attrs &= ~(1 << OVS_KEY_ATTR_UDP);
855 
856 		*key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
857 		udp_key = nla_data(a[OVS_KEY_ATTR_UDP]);
858 		swkey->ipv4.tp.src = udp_key->udp_src;
859 		swkey->ipv4.tp.dst = udp_key->udp_dst;
860 		break;
861 
862 	case IPPROTO_ICMP:
863 		if (!(*attrs & (1 << OVS_KEY_ATTR_ICMP)))
864 			return -EINVAL;
865 		*attrs &= ~(1 << OVS_KEY_ATTR_ICMP);
866 
867 		*key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
868 		icmp_key = nla_data(a[OVS_KEY_ATTR_ICMP]);
869 		swkey->ipv4.tp.src = htons(icmp_key->icmp_type);
870 		swkey->ipv4.tp.dst = htons(icmp_key->icmp_code);
871 		break;
872 	}
873 
874 	return 0;
875 }
876 
ipv6_flow_from_nlattrs(struct sw_flow_key * swkey,int * key_len,const struct nlattr * a[],u32 * attrs)877 static int ipv6_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_len,
878 				  const struct nlattr *a[], u32 *attrs)
879 {
880 	const struct ovs_key_icmpv6 *icmpv6_key;
881 	const struct ovs_key_tcp *tcp_key;
882 	const struct ovs_key_udp *udp_key;
883 
884 	switch (swkey->ip.proto) {
885 	case IPPROTO_TCP:
886 		if (!(*attrs & (1 << OVS_KEY_ATTR_TCP)))
887 			return -EINVAL;
888 		*attrs &= ~(1 << OVS_KEY_ATTR_TCP);
889 
890 		*key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
891 		tcp_key = nla_data(a[OVS_KEY_ATTR_TCP]);
892 		swkey->ipv6.tp.src = tcp_key->tcp_src;
893 		swkey->ipv6.tp.dst = tcp_key->tcp_dst;
894 		break;
895 
896 	case IPPROTO_UDP:
897 		if (!(*attrs & (1 << OVS_KEY_ATTR_UDP)))
898 			return -EINVAL;
899 		*attrs &= ~(1 << OVS_KEY_ATTR_UDP);
900 
901 		*key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
902 		udp_key = nla_data(a[OVS_KEY_ATTR_UDP]);
903 		swkey->ipv6.tp.src = udp_key->udp_src;
904 		swkey->ipv6.tp.dst = udp_key->udp_dst;
905 		break;
906 
907 	case IPPROTO_ICMPV6:
908 		if (!(*attrs & (1 << OVS_KEY_ATTR_ICMPV6)))
909 			return -EINVAL;
910 		*attrs &= ~(1 << OVS_KEY_ATTR_ICMPV6);
911 
912 		*key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
913 		icmpv6_key = nla_data(a[OVS_KEY_ATTR_ICMPV6]);
914 		swkey->ipv6.tp.src = htons(icmpv6_key->icmpv6_type);
915 		swkey->ipv6.tp.dst = htons(icmpv6_key->icmpv6_code);
916 
917 		if (swkey->ipv6.tp.src == htons(NDISC_NEIGHBOUR_SOLICITATION) ||
918 		    swkey->ipv6.tp.src == htons(NDISC_NEIGHBOUR_ADVERTISEMENT)) {
919 			const struct ovs_key_nd *nd_key;
920 
921 			if (!(*attrs & (1 << OVS_KEY_ATTR_ND)))
922 				return -EINVAL;
923 			*attrs &= ~(1 << OVS_KEY_ATTR_ND);
924 
925 			*key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
926 			nd_key = nla_data(a[OVS_KEY_ATTR_ND]);
927 			memcpy(&swkey->ipv6.nd.target, nd_key->nd_target,
928 			       sizeof(swkey->ipv6.nd.target));
929 			memcpy(swkey->ipv6.nd.sll, nd_key->nd_sll, ETH_ALEN);
930 			memcpy(swkey->ipv6.nd.tll, nd_key->nd_tll, ETH_ALEN);
931 		}
932 		break;
933 	}
934 
935 	return 0;
936 }
937 
parse_flow_nlattrs(const struct nlattr * attr,const struct nlattr * a[],u32 * attrsp)938 static int parse_flow_nlattrs(const struct nlattr *attr,
939 			      const struct nlattr *a[], u32 *attrsp)
940 {
941 	const struct nlattr *nla;
942 	u32 attrs;
943 	int rem;
944 
945 	attrs = 0;
946 	nla_for_each_nested(nla, attr, rem) {
947 		u16 type = nla_type(nla);
948 		int expected_len;
949 
950 		if (type > OVS_KEY_ATTR_MAX || attrs & (1 << type))
951 			return -EINVAL;
952 
953 		expected_len = ovs_key_lens[type];
954 		if (nla_len(nla) != expected_len && expected_len != -1)
955 			return -EINVAL;
956 
957 		attrs |= 1 << type;
958 		a[type] = nla;
959 	}
960 	if (rem)
961 		return -EINVAL;
962 
963 	*attrsp = attrs;
964 	return 0;
965 }
966 
967 /**
968  * ovs_flow_from_nlattrs - parses Netlink attributes into a flow key.
969  * @swkey: receives the extracted flow key.
970  * @key_lenp: number of bytes used in @swkey.
971  * @attr: Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink attribute
972  * sequence.
973  */
ovs_flow_from_nlattrs(struct sw_flow_key * swkey,int * key_lenp,const struct nlattr * attr)974 int ovs_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_lenp,
975 		      const struct nlattr *attr)
976 {
977 	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
978 	const struct ovs_key_ethernet *eth_key;
979 	int key_len;
980 	u32 attrs;
981 	int err;
982 
983 	memset(swkey, 0, sizeof(struct sw_flow_key));
984 	key_len = SW_FLOW_KEY_OFFSET(eth);
985 
986 	err = parse_flow_nlattrs(attr, a, &attrs);
987 	if (err)
988 		return err;
989 
990 	/* Metadata attributes. */
991 	if (attrs & (1 << OVS_KEY_ATTR_PRIORITY)) {
992 		swkey->phy.priority = nla_get_u32(a[OVS_KEY_ATTR_PRIORITY]);
993 		attrs &= ~(1 << OVS_KEY_ATTR_PRIORITY);
994 	}
995 	if (attrs & (1 << OVS_KEY_ATTR_IN_PORT)) {
996 		u32 in_port = nla_get_u32(a[OVS_KEY_ATTR_IN_PORT]);
997 		if (in_port >= DP_MAX_PORTS)
998 			return -EINVAL;
999 		swkey->phy.in_port = in_port;
1000 		attrs &= ~(1 << OVS_KEY_ATTR_IN_PORT);
1001 	} else {
1002 		swkey->phy.in_port = USHRT_MAX;
1003 	}
1004 
1005 	/* Data attributes. */
1006 	if (!(attrs & (1 << OVS_KEY_ATTR_ETHERNET)))
1007 		return -EINVAL;
1008 	attrs &= ~(1 << OVS_KEY_ATTR_ETHERNET);
1009 
1010 	eth_key = nla_data(a[OVS_KEY_ATTR_ETHERNET]);
1011 	memcpy(swkey->eth.src, eth_key->eth_src, ETH_ALEN);
1012 	memcpy(swkey->eth.dst, eth_key->eth_dst, ETH_ALEN);
1013 
1014 	if (attrs & (1u << OVS_KEY_ATTR_ETHERTYPE) &&
1015 	    nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]) == htons(ETH_P_8021Q)) {
1016 		const struct nlattr *encap;
1017 		__be16 tci;
1018 
1019 		if (attrs != ((1 << OVS_KEY_ATTR_VLAN) |
1020 			      (1 << OVS_KEY_ATTR_ETHERTYPE) |
1021 			      (1 << OVS_KEY_ATTR_ENCAP)))
1022 			return -EINVAL;
1023 
1024 		encap = a[OVS_KEY_ATTR_ENCAP];
1025 		tci = nla_get_be16(a[OVS_KEY_ATTR_VLAN]);
1026 		if (tci & htons(VLAN_TAG_PRESENT)) {
1027 			swkey->eth.tci = tci;
1028 
1029 			err = parse_flow_nlattrs(encap, a, &attrs);
1030 			if (err)
1031 				return err;
1032 		} else if (!tci) {
1033 			/* Corner case for truncated 802.1Q header. */
1034 			if (nla_len(encap))
1035 				return -EINVAL;
1036 
1037 			swkey->eth.type = htons(ETH_P_8021Q);
1038 			*key_lenp = key_len;
1039 			return 0;
1040 		} else {
1041 			return -EINVAL;
1042 		}
1043 	}
1044 
1045 	if (attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) {
1046 		swkey->eth.type = nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]);
1047 		if (ntohs(swkey->eth.type) < 1536)
1048 			return -EINVAL;
1049 		attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
1050 	} else {
1051 		swkey->eth.type = htons(ETH_P_802_2);
1052 	}
1053 
1054 	if (swkey->eth.type == htons(ETH_P_IP)) {
1055 		const struct ovs_key_ipv4 *ipv4_key;
1056 
1057 		if (!(attrs & (1 << OVS_KEY_ATTR_IPV4)))
1058 			return -EINVAL;
1059 		attrs &= ~(1 << OVS_KEY_ATTR_IPV4);
1060 
1061 		key_len = SW_FLOW_KEY_OFFSET(ipv4.addr);
1062 		ipv4_key = nla_data(a[OVS_KEY_ATTR_IPV4]);
1063 		if (ipv4_key->ipv4_frag > OVS_FRAG_TYPE_MAX)
1064 			return -EINVAL;
1065 		swkey->ip.proto = ipv4_key->ipv4_proto;
1066 		swkey->ip.tos = ipv4_key->ipv4_tos;
1067 		swkey->ip.ttl = ipv4_key->ipv4_ttl;
1068 		swkey->ip.frag = ipv4_key->ipv4_frag;
1069 		swkey->ipv4.addr.src = ipv4_key->ipv4_src;
1070 		swkey->ipv4.addr.dst = ipv4_key->ipv4_dst;
1071 
1072 		if (swkey->ip.frag != OVS_FRAG_TYPE_LATER) {
1073 			err = ipv4_flow_from_nlattrs(swkey, &key_len, a, &attrs);
1074 			if (err)
1075 				return err;
1076 		}
1077 	} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
1078 		const struct ovs_key_ipv6 *ipv6_key;
1079 
1080 		if (!(attrs & (1 << OVS_KEY_ATTR_IPV6)))
1081 			return -EINVAL;
1082 		attrs &= ~(1 << OVS_KEY_ATTR_IPV6);
1083 
1084 		key_len = SW_FLOW_KEY_OFFSET(ipv6.label);
1085 		ipv6_key = nla_data(a[OVS_KEY_ATTR_IPV6]);
1086 		if (ipv6_key->ipv6_frag > OVS_FRAG_TYPE_MAX)
1087 			return -EINVAL;
1088 		swkey->ipv6.label = ipv6_key->ipv6_label;
1089 		swkey->ip.proto = ipv6_key->ipv6_proto;
1090 		swkey->ip.tos = ipv6_key->ipv6_tclass;
1091 		swkey->ip.ttl = ipv6_key->ipv6_hlimit;
1092 		swkey->ip.frag = ipv6_key->ipv6_frag;
1093 		memcpy(&swkey->ipv6.addr.src, ipv6_key->ipv6_src,
1094 		       sizeof(swkey->ipv6.addr.src));
1095 		memcpy(&swkey->ipv6.addr.dst, ipv6_key->ipv6_dst,
1096 		       sizeof(swkey->ipv6.addr.dst));
1097 
1098 		if (swkey->ip.frag != OVS_FRAG_TYPE_LATER) {
1099 			err = ipv6_flow_from_nlattrs(swkey, &key_len, a, &attrs);
1100 			if (err)
1101 				return err;
1102 		}
1103 	} else if (swkey->eth.type == htons(ETH_P_ARP)) {
1104 		const struct ovs_key_arp *arp_key;
1105 
1106 		if (!(attrs & (1 << OVS_KEY_ATTR_ARP)))
1107 			return -EINVAL;
1108 		attrs &= ~(1 << OVS_KEY_ATTR_ARP);
1109 
1110 		key_len = SW_FLOW_KEY_OFFSET(ipv4.arp);
1111 		arp_key = nla_data(a[OVS_KEY_ATTR_ARP]);
1112 		swkey->ipv4.addr.src = arp_key->arp_sip;
1113 		swkey->ipv4.addr.dst = arp_key->arp_tip;
1114 		if (arp_key->arp_op & htons(0xff00))
1115 			return -EINVAL;
1116 		swkey->ip.proto = ntohs(arp_key->arp_op);
1117 		memcpy(swkey->ipv4.arp.sha, arp_key->arp_sha, ETH_ALEN);
1118 		memcpy(swkey->ipv4.arp.tha, arp_key->arp_tha, ETH_ALEN);
1119 	}
1120 
1121 	if (attrs)
1122 		return -EINVAL;
1123 	*key_lenp = key_len;
1124 
1125 	return 0;
1126 }
1127 
1128 /**
1129  * ovs_flow_metadata_from_nlattrs - parses Netlink attributes into a flow key.
1130  * @in_port: receives the extracted input port.
1131  * @key: Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink attribute
1132  * sequence.
1133  *
1134  * This parses a series of Netlink attributes that form a flow key, which must
1135  * take the same form accepted by flow_from_nlattrs(), but only enough of it to
1136  * get the metadata, that is, the parts of the flow key that cannot be
1137  * extracted from the packet itself.
1138  */
ovs_flow_metadata_from_nlattrs(u32 * priority,u16 * in_port,const struct nlattr * attr)1139 int ovs_flow_metadata_from_nlattrs(u32 *priority, u16 *in_port,
1140 			       const struct nlattr *attr)
1141 {
1142 	const struct nlattr *nla;
1143 	int rem;
1144 
1145 	*in_port = USHRT_MAX;
1146 	*priority = 0;
1147 
1148 	nla_for_each_nested(nla, attr, rem) {
1149 		int type = nla_type(nla);
1150 
1151 		if (type <= OVS_KEY_ATTR_MAX && ovs_key_lens[type] > 0) {
1152 			if (nla_len(nla) != ovs_key_lens[type])
1153 				return -EINVAL;
1154 
1155 			switch (type) {
1156 			case OVS_KEY_ATTR_PRIORITY:
1157 				*priority = nla_get_u32(nla);
1158 				break;
1159 
1160 			case OVS_KEY_ATTR_IN_PORT:
1161 				if (nla_get_u32(nla) >= DP_MAX_PORTS)
1162 					return -EINVAL;
1163 				*in_port = nla_get_u32(nla);
1164 				break;
1165 			}
1166 		}
1167 	}
1168 	if (rem)
1169 		return -EINVAL;
1170 	return 0;
1171 }
1172 
ovs_flow_to_nlattrs(const struct sw_flow_key * swkey,struct sk_buff * skb)1173 int ovs_flow_to_nlattrs(const struct sw_flow_key *swkey, struct sk_buff *skb)
1174 {
1175 	struct ovs_key_ethernet *eth_key;
1176 	struct nlattr *nla, *encap;
1177 
1178 	if (swkey->phy.priority)
1179 		NLA_PUT_U32(skb, OVS_KEY_ATTR_PRIORITY, swkey->phy.priority);
1180 
1181 	if (swkey->phy.in_port != USHRT_MAX)
1182 		NLA_PUT_U32(skb, OVS_KEY_ATTR_IN_PORT, swkey->phy.in_port);
1183 
1184 	nla = nla_reserve(skb, OVS_KEY_ATTR_ETHERNET, sizeof(*eth_key));
1185 	if (!nla)
1186 		goto nla_put_failure;
1187 	eth_key = nla_data(nla);
1188 	memcpy(eth_key->eth_src, swkey->eth.src, ETH_ALEN);
1189 	memcpy(eth_key->eth_dst, swkey->eth.dst, ETH_ALEN);
1190 
1191 	if (swkey->eth.tci || swkey->eth.type == htons(ETH_P_8021Q)) {
1192 		NLA_PUT_BE16(skb, OVS_KEY_ATTR_ETHERTYPE, htons(ETH_P_8021Q));
1193 		NLA_PUT_BE16(skb, OVS_KEY_ATTR_VLAN, swkey->eth.tci);
1194 		encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
1195 		if (!swkey->eth.tci)
1196 			goto unencap;
1197 	} else {
1198 		encap = NULL;
1199 	}
1200 
1201 	if (swkey->eth.type == htons(ETH_P_802_2))
1202 		goto unencap;
1203 
1204 	NLA_PUT_BE16(skb, OVS_KEY_ATTR_ETHERTYPE, swkey->eth.type);
1205 
1206 	if (swkey->eth.type == htons(ETH_P_IP)) {
1207 		struct ovs_key_ipv4 *ipv4_key;
1208 
1209 		nla = nla_reserve(skb, OVS_KEY_ATTR_IPV4, sizeof(*ipv4_key));
1210 		if (!nla)
1211 			goto nla_put_failure;
1212 		ipv4_key = nla_data(nla);
1213 		ipv4_key->ipv4_src = swkey->ipv4.addr.src;
1214 		ipv4_key->ipv4_dst = swkey->ipv4.addr.dst;
1215 		ipv4_key->ipv4_proto = swkey->ip.proto;
1216 		ipv4_key->ipv4_tos = swkey->ip.tos;
1217 		ipv4_key->ipv4_ttl = swkey->ip.ttl;
1218 		ipv4_key->ipv4_frag = swkey->ip.frag;
1219 	} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
1220 		struct ovs_key_ipv6 *ipv6_key;
1221 
1222 		nla = nla_reserve(skb, OVS_KEY_ATTR_IPV6, sizeof(*ipv6_key));
1223 		if (!nla)
1224 			goto nla_put_failure;
1225 		ipv6_key = nla_data(nla);
1226 		memcpy(ipv6_key->ipv6_src, &swkey->ipv6.addr.src,
1227 				sizeof(ipv6_key->ipv6_src));
1228 		memcpy(ipv6_key->ipv6_dst, &swkey->ipv6.addr.dst,
1229 				sizeof(ipv6_key->ipv6_dst));
1230 		ipv6_key->ipv6_label = swkey->ipv6.label;
1231 		ipv6_key->ipv6_proto = swkey->ip.proto;
1232 		ipv6_key->ipv6_tclass = swkey->ip.tos;
1233 		ipv6_key->ipv6_hlimit = swkey->ip.ttl;
1234 		ipv6_key->ipv6_frag = swkey->ip.frag;
1235 	} else if (swkey->eth.type == htons(ETH_P_ARP)) {
1236 		struct ovs_key_arp *arp_key;
1237 
1238 		nla = nla_reserve(skb, OVS_KEY_ATTR_ARP, sizeof(*arp_key));
1239 		if (!nla)
1240 			goto nla_put_failure;
1241 		arp_key = nla_data(nla);
1242 		memset(arp_key, 0, sizeof(struct ovs_key_arp));
1243 		arp_key->arp_sip = swkey->ipv4.addr.src;
1244 		arp_key->arp_tip = swkey->ipv4.addr.dst;
1245 		arp_key->arp_op = htons(swkey->ip.proto);
1246 		memcpy(arp_key->arp_sha, swkey->ipv4.arp.sha, ETH_ALEN);
1247 		memcpy(arp_key->arp_tha, swkey->ipv4.arp.tha, ETH_ALEN);
1248 	}
1249 
1250 	if ((swkey->eth.type == htons(ETH_P_IP) ||
1251 	     swkey->eth.type == htons(ETH_P_IPV6)) &&
1252 	     swkey->ip.frag != OVS_FRAG_TYPE_LATER) {
1253 
1254 		if (swkey->ip.proto == IPPROTO_TCP) {
1255 			struct ovs_key_tcp *tcp_key;
1256 
1257 			nla = nla_reserve(skb, OVS_KEY_ATTR_TCP, sizeof(*tcp_key));
1258 			if (!nla)
1259 				goto nla_put_failure;
1260 			tcp_key = nla_data(nla);
1261 			if (swkey->eth.type == htons(ETH_P_IP)) {
1262 				tcp_key->tcp_src = swkey->ipv4.tp.src;
1263 				tcp_key->tcp_dst = swkey->ipv4.tp.dst;
1264 			} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
1265 				tcp_key->tcp_src = swkey->ipv6.tp.src;
1266 				tcp_key->tcp_dst = swkey->ipv6.tp.dst;
1267 			}
1268 		} else if (swkey->ip.proto == IPPROTO_UDP) {
1269 			struct ovs_key_udp *udp_key;
1270 
1271 			nla = nla_reserve(skb, OVS_KEY_ATTR_UDP, sizeof(*udp_key));
1272 			if (!nla)
1273 				goto nla_put_failure;
1274 			udp_key = nla_data(nla);
1275 			if (swkey->eth.type == htons(ETH_P_IP)) {
1276 				udp_key->udp_src = swkey->ipv4.tp.src;
1277 				udp_key->udp_dst = swkey->ipv4.tp.dst;
1278 			} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
1279 				udp_key->udp_src = swkey->ipv6.tp.src;
1280 				udp_key->udp_dst = swkey->ipv6.tp.dst;
1281 			}
1282 		} else if (swkey->eth.type == htons(ETH_P_IP) &&
1283 			   swkey->ip.proto == IPPROTO_ICMP) {
1284 			struct ovs_key_icmp *icmp_key;
1285 
1286 			nla = nla_reserve(skb, OVS_KEY_ATTR_ICMP, sizeof(*icmp_key));
1287 			if (!nla)
1288 				goto nla_put_failure;
1289 			icmp_key = nla_data(nla);
1290 			icmp_key->icmp_type = ntohs(swkey->ipv4.tp.src);
1291 			icmp_key->icmp_code = ntohs(swkey->ipv4.tp.dst);
1292 		} else if (swkey->eth.type == htons(ETH_P_IPV6) &&
1293 			   swkey->ip.proto == IPPROTO_ICMPV6) {
1294 			struct ovs_key_icmpv6 *icmpv6_key;
1295 
1296 			nla = nla_reserve(skb, OVS_KEY_ATTR_ICMPV6,
1297 						sizeof(*icmpv6_key));
1298 			if (!nla)
1299 				goto nla_put_failure;
1300 			icmpv6_key = nla_data(nla);
1301 			icmpv6_key->icmpv6_type = ntohs(swkey->ipv6.tp.src);
1302 			icmpv6_key->icmpv6_code = ntohs(swkey->ipv6.tp.dst);
1303 
1304 			if (icmpv6_key->icmpv6_type == NDISC_NEIGHBOUR_SOLICITATION ||
1305 			    icmpv6_key->icmpv6_type == NDISC_NEIGHBOUR_ADVERTISEMENT) {
1306 				struct ovs_key_nd *nd_key;
1307 
1308 				nla = nla_reserve(skb, OVS_KEY_ATTR_ND, sizeof(*nd_key));
1309 				if (!nla)
1310 					goto nla_put_failure;
1311 				nd_key = nla_data(nla);
1312 				memcpy(nd_key->nd_target, &swkey->ipv6.nd.target,
1313 							sizeof(nd_key->nd_target));
1314 				memcpy(nd_key->nd_sll, swkey->ipv6.nd.sll, ETH_ALEN);
1315 				memcpy(nd_key->nd_tll, swkey->ipv6.nd.tll, ETH_ALEN);
1316 			}
1317 		}
1318 	}
1319 
1320 unencap:
1321 	if (encap)
1322 		nla_nest_end(skb, encap);
1323 
1324 	return 0;
1325 
1326 nla_put_failure:
1327 	return -EMSGSIZE;
1328 }
1329 
1330 /* Initializes the flow module.
1331  * Returns zero if successful or a negative error code. */
ovs_flow_init(void)1332 int ovs_flow_init(void)
1333 {
1334 	flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
1335 					0, NULL);
1336 	if (flow_cache == NULL)
1337 		return -ENOMEM;
1338 
1339 	return 0;
1340 }
1341 
1342 /* Uninitializes the flow module. */
ovs_flow_exit(void)1343 void ovs_flow_exit(void)
1344 {
1345 	kmem_cache_destroy(flow_cache);
1346 }
1347