projects/linux·blob v3.13 · refs

524 lines · 13.6 KiB

1/*
2 * Copyright (c) 2007-2013 Nicira, Inc.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16 * 02110-1301, USA
17 */
18
19#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/sctp.h>
38#include <linux/tcp.h>
39#include <linux/udp.h>
40#include <linux/icmp.h>
41#include <linux/icmpv6.h>
42#include <linux/rculist.h>
43#include <net/ip.h>
44#include <net/ip_tunnels.h>
45#include <net/ipv6.h>
46#include <net/ndisc.h>
47
48u64 ovs_flow_used_time(unsigned long flow_jiffies)
49{
50 struct timespec cur_ts;
51 u64 cur_ms, idle_ms;
52
53 ktime_get_ts(&cur_ts);
54 idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
55 cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC +
56 cur_ts.tv_nsec / NSEC_PER_MSEC;
57
58 return cur_ms - idle_ms;
59}
60
61#define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF))
62
63void ovs_flow_used(struct sw_flow *flow, struct sk_buff *skb)
64{
65 __be16 tcp_flags = 0;
66
67 if ((flow->key.eth.type == htons(ETH_P_IP) ||
68 flow->key.eth.type == htons(ETH_P_IPV6)) &&
69 flow->key.ip.proto == IPPROTO_TCP &&
70 likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) {
71 tcp_flags = TCP_FLAGS_BE16(tcp_hdr(skb));
72 }
73
74 spin_lock(&flow->lock);
75 flow->used = jiffies;
76 flow->packet_count++;
77 flow->byte_count += skb->len;
78 flow->tcp_flags |= tcp_flags;
79 spin_unlock(&flow->lock);
80}
81
82static int check_header(struct sk_buff *skb, int len)
83{
84 if (unlikely(skb->len < len))
85 return -EINVAL;
86 if (unlikely(!pskb_may_pull(skb, len)))
87 return -ENOMEM;
88 return 0;
89}
90
91static bool arphdr_ok(struct sk_buff *skb)
92{
93 return pskb_may_pull(skb, skb_network_offset(skb) +
94 sizeof(struct arp_eth_header));
95}
96
97static int check_iphdr(struct sk_buff *skb)
98{
99 unsigned int nh_ofs = skb_network_offset(skb);
100 unsigned int ip_len;
101 int err;
102
103 err = check_header(skb, nh_ofs + sizeof(struct iphdr));
104 if (unlikely(err))
105 return err;
106
107 ip_len = ip_hdrlen(skb);
108 if (unlikely(ip_len < sizeof(struct iphdr) ||
109 skb->len < nh_ofs + ip_len))
110 return -EINVAL;
111
112 skb_set_transport_header(skb, nh_ofs + ip_len);
113 return 0;
114}
115
116static bool tcphdr_ok(struct sk_buff *skb)
117{
118 int th_ofs = skb_transport_offset(skb);
119 int tcp_len;
120
121 if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
122 return false;
123
124 tcp_len = tcp_hdrlen(skb);
125 if (unlikely(tcp_len < sizeof(struct tcphdr) ||
126 skb->len < th_ofs + tcp_len))
127 return false;
128
129 return true;
130}
131
132static bool udphdr_ok(struct sk_buff *skb)
133{
134 return pskb_may_pull(skb, skb_transport_offset(skb) +
135 sizeof(struct udphdr));
136}
137
138static bool sctphdr_ok(struct sk_buff *skb)
139{
140 return pskb_may_pull(skb, skb_transport_offset(skb) +
141 sizeof(struct sctphdr));
142}
143
144static bool icmphdr_ok(struct sk_buff *skb)
145{
146 return pskb_may_pull(skb, skb_transport_offset(skb) +
147 sizeof(struct icmphdr));
148}
149
150static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
151{
152 unsigned int nh_ofs = skb_network_offset(skb);
153 unsigned int nh_len;
154 int payload_ofs;
155 struct ipv6hdr *nh;
156 uint8_t nexthdr;
157 __be16 frag_off;
158 int err;
159
160 err = check_header(skb, nh_ofs + sizeof(*nh));
161 if (unlikely(err))
162 return err;
163
164 nh = ipv6_hdr(skb);
165 nexthdr = nh->nexthdr;
166 payload_ofs = (u8 *)(nh + 1) - skb->data;
167
168 key->ip.proto = NEXTHDR_NONE;
169 key->ip.tos = ipv6_get_dsfield(nh);
170 key->ip.ttl = nh->hop_limit;
171 key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
172 key->ipv6.addr.src = nh->saddr;
173 key->ipv6.addr.dst = nh->daddr;
174
175 payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);
176 if (unlikely(payload_ofs < 0))
177 return -EINVAL;
178
179 if (frag_off) {
180 if (frag_off & htons(~0x7))
181 key->ip.frag = OVS_FRAG_TYPE_LATER;
182 else
183 key->ip.frag = OVS_FRAG_TYPE_FIRST;
184 }
185
186 nh_len = payload_ofs - nh_ofs;
187 skb_set_transport_header(skb, nh_ofs + nh_len);
188 key->ip.proto = nexthdr;
189 return nh_len;
190}
191
192static bool icmp6hdr_ok(struct sk_buff *skb)
193{
194 return pskb_may_pull(skb, skb_transport_offset(skb) +
195 sizeof(struct icmp6hdr));
196}
197
198static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
199{
200 struct qtag_prefix {
201 __be16 eth_type; /* ETH_P_8021Q */
202 __be16 tci;
203 };
204 struct qtag_prefix *qp;
205
206 if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16)))
207 return 0;
208
209 if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
210 sizeof(__be16))))
211 return -ENOMEM;
212
213 qp = (struct qtag_prefix *) skb->data;
214 key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
215 __skb_pull(skb, sizeof(struct qtag_prefix));
216
217 return 0;
218}
219
220static __be16 parse_ethertype(struct sk_buff *skb)
221{
222 struct llc_snap_hdr {
223 u8 dsap; /* Always 0xAA */
224 u8 ssap; /* Always 0xAA */
225 u8 ctrl;
226 u8 oui[3];
227 __be16 ethertype;
228 };
229 struct llc_snap_hdr *llc;
230 __be16 proto;
231
232 proto = *(__be16 *) skb->data;
233 __skb_pull(skb, sizeof(__be16));
234
235 if (ntohs(proto) >= ETH_P_802_3_MIN)
236 return proto;
237
238 if (skb->len < sizeof(struct llc_snap_hdr))
239 return htons(ETH_P_802_2);
240
241 if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
242 return htons(0);
243
244 llc = (struct llc_snap_hdr *) skb->data;
245 if (llc->dsap != LLC_SAP_SNAP ||
246 llc->ssap != LLC_SAP_SNAP ||
247 (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
248 return htons(ETH_P_802_2);
249
250 __skb_pull(skb, sizeof(struct llc_snap_hdr));
251
252 if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN)
253 return llc->ethertype;
254
255 return htons(ETH_P_802_2);
256}
257
258static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
259 int nh_len)
260{
261 struct icmp6hdr *icmp = icmp6_hdr(skb);
262
263 /* The ICMPv6 type and code fields use the 16-bit transport port
264 * fields, so we need to store them in 16-bit network byte order.
265 */
266 key->ipv6.tp.src = htons(icmp->icmp6_type);
267 key->ipv6.tp.dst = htons(icmp->icmp6_code);
268
269 if (icmp->icmp6_code == 0 &&
270 (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
271 icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
272 int icmp_len = skb->len - skb_transport_offset(skb);
273 struct nd_msg *nd;
274 int offset;
275
276 /* In order to process neighbor discovery options, we need the
277 * entire packet.
278 */
279 if (unlikely(icmp_len < sizeof(*nd)))
280 return 0;
281
282 if (unlikely(skb_linearize(skb)))
283 return -ENOMEM;
284
285 nd = (struct nd_msg *)skb_transport_header(skb);
286 key->ipv6.nd.target = nd->target;
287
288 icmp_len -= sizeof(*nd);
289 offset = 0;
290 while (icmp_len >= 8) {
291 struct nd_opt_hdr *nd_opt =
292 (struct nd_opt_hdr *)(nd->opt + offset);
293 int opt_len = nd_opt->nd_opt_len * 8;
294
295 if (unlikely(!opt_len || opt_len > icmp_len))
296 return 0;
297
298 /* Store the link layer address if the appropriate
299 * option is provided. It is considered an error if
300 * the same link layer option is specified twice.
301 */
302 if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
303 && opt_len == 8) {
304 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
305 goto invalid;
306 memcpy(key->ipv6.nd.sll,
307 &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
308 } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
309 && opt_len == 8) {
310 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
311 goto invalid;
312 memcpy(key->ipv6.nd.tll,
313 &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
314 }
315
316 icmp_len -= opt_len;
317 offset += opt_len;
318 }
319 }
320
321 return 0;
322
323invalid:
324 memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
325 memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
326 memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
327
328 return 0;
329}
330
331/**
332 * ovs_flow_extract - extracts a flow key from an Ethernet frame.
333 * @skb: sk_buff that contains the frame, with skb->data pointing to the
334 * Ethernet header
335 * @in_port: port number on which @skb was received.
336 * @key: output flow key
337 *
338 * The caller must ensure that skb->len >= ETH_HLEN.
339 *
340 * Returns 0 if successful, otherwise a negative errno value.
341 *
342 * Initializes @skb header pointers as follows:
343 *
344 * - skb->mac_header: the Ethernet header.
345 *
346 * - skb->network_header: just past the Ethernet header, or just past the
347 * VLAN header, to the first byte of the Ethernet payload.
348 *
349 * - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
350 * on output, then just past the IP header, if one is present and
351 * of a correct length, otherwise the same as skb->network_header.
352 * For other key->eth.type values it is left untouched.
353 */
354int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key)
355{
356 int error;
357 struct ethhdr *eth;
358
359 memset(key, 0, sizeof(*key));
360
361 key->phy.priority = skb->priority;
362 if (OVS_CB(skb)->tun_key)
363 memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key));
364 key->phy.in_port = in_port;
365 key->phy.skb_mark = skb->mark;
366
367 skb_reset_mac_header(skb);
368
369 /* Link layer. We are guaranteed to have at least the 14 byte Ethernet
370 * header in the linear data area.
371 */
372 eth = eth_hdr(skb);
373 memcpy(key->eth.src, eth->h_source, ETH_ALEN);
374 memcpy(key->eth.dst, eth->h_dest, ETH_ALEN);
375
376 __skb_pull(skb, 2 * ETH_ALEN);
377 /* We are going to push all headers that we pull, so no need to
378 * update skb->csum here.
379 */
380
381 if (vlan_tx_tag_present(skb))
382 key->eth.tci = htons(skb->vlan_tci);
383 else if (eth->h_proto == htons(ETH_P_8021Q))
384 if (unlikely(parse_vlan(skb, key)))
385 return -ENOMEM;
386
387 key->eth.type = parse_ethertype(skb);
388 if (unlikely(key->eth.type == htons(0)))
389 return -ENOMEM;
390
391 skb_reset_network_header(skb);
392 __skb_push(skb, skb->data - skb_mac_header(skb));
393
394 /* Network layer. */
395 if (key->eth.type == htons(ETH_P_IP)) {
396 struct iphdr *nh;
397 __be16 offset;
398
399 error = check_iphdr(skb);
400 if (unlikely(error)) {
401 if (error == -EINVAL) {
402 skb->transport_header = skb->network_header;
403 error = 0;
404 }
405 return error;
406 }
407
408 nh = ip_hdr(skb);
409 key->ipv4.addr.src = nh->saddr;
410 key->ipv4.addr.dst = nh->daddr;
411
412 key->ip.proto = nh->protocol;
413 key->ip.tos = nh->tos;
414 key->ip.ttl = nh->ttl;
415
416 offset = nh->frag_off & htons(IP_OFFSET);
417 if (offset) {
418 key->ip.frag = OVS_FRAG_TYPE_LATER;
419 return 0;
420 }
421 if (nh->frag_off & htons(IP_MF) ||
422 skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
423 key->ip.frag = OVS_FRAG_TYPE_FIRST;
424
425 /* Transport layer. */
426 if (key->ip.proto == IPPROTO_TCP) {
427 if (tcphdr_ok(skb)) {
428 struct tcphdr *tcp = tcp_hdr(skb);
429 key->ipv4.tp.src = tcp->source;
430 key->ipv4.tp.dst = tcp->dest;
431 key->ipv4.tp.flags = TCP_FLAGS_BE16(tcp);
432 }
433 } else if (key->ip.proto == IPPROTO_UDP) {
434 if (udphdr_ok(skb)) {
435 struct udphdr *udp = udp_hdr(skb);
436 key->ipv4.tp.src = udp->source;
437 key->ipv4.tp.dst = udp->dest;
438 }
439 } else if (key->ip.proto == IPPROTO_SCTP) {
440 if (sctphdr_ok(skb)) {
441 struct sctphdr *sctp = sctp_hdr(skb);
442 key->ipv4.tp.src = sctp->source;
443 key->ipv4.tp.dst = sctp->dest;
444 }
445 } else if (key->ip.proto == IPPROTO_ICMP) {
446 if (icmphdr_ok(skb)) {
447 struct icmphdr *icmp = icmp_hdr(skb);
448 /* The ICMP type and code fields use the 16-bit
449 * transport port fields, so we need to store
450 * them in 16-bit network byte order. */
451 key->ipv4.tp.src = htons(icmp->type);
452 key->ipv4.tp.dst = htons(icmp->code);
453 }
454 }
455
456 } else if ((key->eth.type == htons(ETH_P_ARP) ||
457 key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) {
458 struct arp_eth_header *arp;
459
460 arp = (struct arp_eth_header *)skb_network_header(skb);
461
462 if (arp->ar_hrd == htons(ARPHRD_ETHER)
463 && arp->ar_pro == htons(ETH_P_IP)
464 && arp->ar_hln == ETH_ALEN
465 && arp->ar_pln == 4) {
466
467 /* We only match on the lower 8 bits of the opcode. */
468 if (ntohs(arp->ar_op) <= 0xff)
469 key->ip.proto = ntohs(arp->ar_op);
470 memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
471 memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
472 memcpy(key->ipv4.arp.sha, arp->ar_sha, ETH_ALEN);
473 memcpy(key->ipv4.arp.tha, arp->ar_tha, ETH_ALEN);
474 }
475 } else if (key->eth.type == htons(ETH_P_IPV6)) {
476 int nh_len; /* IPv6 Header + Extensions */
477
478 nh_len = parse_ipv6hdr(skb, key);
479 if (unlikely(nh_len < 0)) {
480 if (nh_len == -EINVAL) {
481 skb->transport_header = skb->network_header;
482 error = 0;
483 } else {
484 error = nh_len;
485 }
486 return error;
487 }
488
489 if (key->ip.frag == OVS_FRAG_TYPE_LATER)
490 return 0;
491 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
492 key->ip.frag = OVS_FRAG_TYPE_FIRST;
493
494 /* Transport layer. */
495 if (key->ip.proto == NEXTHDR_TCP) {
496 if (tcphdr_ok(skb)) {
497 struct tcphdr *tcp = tcp_hdr(skb);
498 key->ipv6.tp.src = tcp->source;
499 key->ipv6.tp.dst = tcp->dest;
500 key->ipv6.tp.flags = TCP_FLAGS_BE16(tcp);
501 }
502 } else if (key->ip.proto == NEXTHDR_UDP) {
503 if (udphdr_ok(skb)) {
504 struct udphdr *udp = udp_hdr(skb);
505 key->ipv6.tp.src = udp->source;
506 key->ipv6.tp.dst = udp->dest;
507 }
508 } else if (key->ip.proto == NEXTHDR_SCTP) {
509 if (sctphdr_ok(skb)) {
510 struct sctphdr *sctp = sctp_hdr(skb);
511 key->ipv6.tp.src = sctp->source;
512 key->ipv6.tp.dst = sctp->dest;
513 }
514 } else if (key->ip.proto == NEXTHDR_ICMP) {
515 if (icmp6hdr_ok(skb)) {
516 error = parse_icmpv6(skb, key, nh_len);
517 if (error)
518 return error;
519 }
520 }
521 }
522
523 return 0;
524}