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1/* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU General Public License as
5 * published by the Free Software Foundation; either version 2 of
6 * the License, or (at your option) any later version.
7 *
8 */
9
10#include "ipvlan.h"
11
12static u32 ipvlan_jhash_secret __read_mostly;
13
14void ipvlan_init_secret(void)
15{
16 net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
17}
18
19static void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
20 unsigned int len, bool success, bool mcast)
21{
22 if (!ipvlan)
23 return;
24
25 if (likely(success)) {
26 struct ipvl_pcpu_stats *pcptr;
27
28 pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
29 u64_stats_update_begin(&pcptr->syncp);
30 pcptr->rx_pkts++;
31 pcptr->rx_bytes += len;
32 if (mcast)
33 pcptr->rx_mcast++;
34 u64_stats_update_end(&pcptr->syncp);
35 } else {
36 this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
37 }
38}
39
40static u8 ipvlan_get_v6_hash(const void *iaddr)
41{
42 const struct in6_addr *ip6_addr = iaddr;
43
44 return __ipv6_addr_jhash(ip6_addr, ipvlan_jhash_secret) &
45 IPVLAN_HASH_MASK;
46}
47
48static u8 ipvlan_get_v4_hash(const void *iaddr)
49{
50 const struct in_addr *ip4_addr = iaddr;
51
52 return jhash_1word(ip4_addr->s_addr, ipvlan_jhash_secret) &
53 IPVLAN_HASH_MASK;
54}
55
56static struct ipvl_addr *ipvlan_ht_addr_lookup(const struct ipvl_port *port,
57 const void *iaddr, bool is_v6)
58{
59 struct ipvl_addr *addr;
60 u8 hash;
61
62 hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
63 ipvlan_get_v4_hash(iaddr);
64 hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode) {
65 if (is_v6 && addr->atype == IPVL_IPV6 &&
66 ipv6_addr_equal(&addr->ip6addr, iaddr))
67 return addr;
68 else if (!is_v6 && addr->atype == IPVL_IPV4 &&
69 addr->ip4addr.s_addr ==
70 ((struct in_addr *)iaddr)->s_addr)
71 return addr;
72 }
73 return NULL;
74}
75
76void ipvlan_ht_addr_add(struct ipvl_dev *ipvlan, struct ipvl_addr *addr)
77{
78 struct ipvl_port *port = ipvlan->port;
79 u8 hash;
80
81 hash = (addr->atype == IPVL_IPV6) ?
82 ipvlan_get_v6_hash(&addr->ip6addr) :
83 ipvlan_get_v4_hash(&addr->ip4addr);
84 if (hlist_unhashed(&addr->hlnode))
85 hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
86}
87
88void ipvlan_ht_addr_del(struct ipvl_addr *addr)
89{
90 hlist_del_init_rcu(&addr->hlnode);
91}
92
93struct ipvl_addr *ipvlan_find_addr(const struct ipvl_dev *ipvlan,
94 const void *iaddr, bool is_v6)
95{
96 struct ipvl_addr *addr;
97
98 list_for_each_entry(addr, &ipvlan->addrs, anode) {
99 if ((is_v6 && addr->atype == IPVL_IPV6 &&
100 ipv6_addr_equal(&addr->ip6addr, iaddr)) ||
101 (!is_v6 && addr->atype == IPVL_IPV4 &&
102 addr->ip4addr.s_addr == ((struct in_addr *)iaddr)->s_addr))
103 return addr;
104 }
105 return NULL;
106}
107
108bool ipvlan_addr_busy(struct ipvl_port *port, void *iaddr, bool is_v6)
109{
110 struct ipvl_dev *ipvlan;
111
112 ASSERT_RTNL();
113
114 list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
115 if (ipvlan_find_addr(ipvlan, iaddr, is_v6))
116 return true;
117 }
118 return false;
119}
120
121static void *ipvlan_get_L3_hdr(struct sk_buff *skb, int *type)
122{
123 void *lyr3h = NULL;
124
125 switch (skb->protocol) {
126 case htons(ETH_P_ARP): {
127 struct arphdr *arph;
128
129 if (unlikely(!pskb_may_pull(skb, sizeof(*arph))))
130 return NULL;
131
132 arph = arp_hdr(skb);
133 *type = IPVL_ARP;
134 lyr3h = arph;
135 break;
136 }
137 case htons(ETH_P_IP): {
138 u32 pktlen;
139 struct iphdr *ip4h;
140
141 if (unlikely(!pskb_may_pull(skb, sizeof(*ip4h))))
142 return NULL;
143
144 ip4h = ip_hdr(skb);
145 pktlen = ntohs(ip4h->tot_len);
146 if (ip4h->ihl < 5 || ip4h->version != 4)
147 return NULL;
148 if (skb->len < pktlen || pktlen < (ip4h->ihl * 4))
149 return NULL;
150
151 *type = IPVL_IPV4;
152 lyr3h = ip4h;
153 break;
154 }
155 case htons(ETH_P_IPV6): {
156 struct ipv6hdr *ip6h;
157
158 if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
159 return NULL;
160
161 ip6h = ipv6_hdr(skb);
162 if (ip6h->version != 6)
163 return NULL;
164
165 *type = IPVL_IPV6;
166 lyr3h = ip6h;
167 /* Only Neighbour Solicitation pkts need different treatment */
168 if (ipv6_addr_any(&ip6h->saddr) &&
169 ip6h->nexthdr == NEXTHDR_ICMP) {
170 *type = IPVL_ICMPV6;
171 lyr3h = ip6h + 1;
172 }
173 break;
174 }
175 default:
176 return NULL;
177 }
178
179 return lyr3h;
180}
181
182unsigned int ipvlan_mac_hash(const unsigned char *addr)
183{
184 u32 hash = jhash_1word(__get_unaligned_cpu32(addr+2),
185 ipvlan_jhash_secret);
186
187 return hash & IPVLAN_MAC_FILTER_MASK;
188}
189
190void ipvlan_process_multicast(struct work_struct *work)
191{
192 struct ipvl_port *port = container_of(work, struct ipvl_port, wq);
193 struct ethhdr *ethh;
194 struct ipvl_dev *ipvlan;
195 struct sk_buff *skb, *nskb;
196 struct sk_buff_head list;
197 unsigned int len;
198 unsigned int mac_hash;
199 int ret;
200 u8 pkt_type;
201 bool hlocal, dlocal;
202
203 __skb_queue_head_init(&list);
204
205 spin_lock_bh(&port->backlog.lock);
206 skb_queue_splice_tail_init(&port->backlog, &list);
207 spin_unlock_bh(&port->backlog.lock);
208
209 while ((skb = __skb_dequeue(&list)) != NULL) {
210 ethh = eth_hdr(skb);
211 hlocal = ether_addr_equal(ethh->h_source, port->dev->dev_addr);
212 mac_hash = ipvlan_mac_hash(ethh->h_dest);
213
214 if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
215 pkt_type = PACKET_BROADCAST;
216 else
217 pkt_type = PACKET_MULTICAST;
218
219 dlocal = false;
220 rcu_read_lock();
221 list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
222 if (hlocal && (ipvlan->dev == skb->dev)) {
223 dlocal = true;
224 continue;
225 }
226 if (!test_bit(mac_hash, ipvlan->mac_filters))
227 continue;
228
229 ret = NET_RX_DROP;
230 len = skb->len + ETH_HLEN;
231 nskb = skb_clone(skb, GFP_ATOMIC);
232 if (!nskb)
233 goto acct;
234
235 nskb->pkt_type = pkt_type;
236 nskb->dev = ipvlan->dev;
237 if (hlocal)
238 ret = dev_forward_skb(ipvlan->dev, nskb);
239 else
240 ret = netif_rx(nskb);
241acct:
242 ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
243 }
244 rcu_read_unlock();
245
246 if (dlocal) {
247 /* If the packet originated here, send it out. */
248 skb->dev = port->dev;
249 skb->pkt_type = pkt_type;
250 dev_queue_xmit(skb);
251 } else {
252 kfree_skb(skb);
253 }
254 }
255}
256
257static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
258 bool local)
259{
260 struct ipvl_dev *ipvlan = addr->master;
261 struct net_device *dev = ipvlan->dev;
262 unsigned int len;
263 rx_handler_result_t ret = RX_HANDLER_CONSUMED;
264 bool success = false;
265 struct sk_buff *skb = *pskb;
266
267 len = skb->len + ETH_HLEN;
268 /* Only packets exchanged between two local slaves need to have
269 * device-up check as well as skb-share check.
270 */
271 if (local) {
272 if (unlikely(!(dev->flags & IFF_UP))) {
273 kfree_skb(skb);
274 goto out;
275 }
276
277 skb = skb_share_check(skb, GFP_ATOMIC);
278 if (!skb)
279 goto out;
280
281 *pskb = skb;
282 }
283 skb->dev = dev;
284
285 if (local) {
286 skb->pkt_type = PACKET_HOST;
287 if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
288 success = true;
289 } else {
290 ret = RX_HANDLER_ANOTHER;
291 success = true;
292 }
293
294out:
295 ipvlan_count_rx(ipvlan, len, success, false);
296 return ret;
297}
298
299static struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port,
300 void *lyr3h, int addr_type,
301 bool use_dest)
302{
303 struct ipvl_addr *addr = NULL;
304
305 if (addr_type == IPVL_IPV6) {
306 struct ipv6hdr *ip6h;
307 struct in6_addr *i6addr;
308
309 ip6h = (struct ipv6hdr *)lyr3h;
310 i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
311 addr = ipvlan_ht_addr_lookup(port, i6addr, true);
312 } else if (addr_type == IPVL_ICMPV6) {
313 struct nd_msg *ndmh;
314 struct in6_addr *i6addr;
315
316 /* Make sure that the NeighborSolicitation ICMPv6 packets
317 * are handled to avoid DAD issue.
318 */
319 ndmh = (struct nd_msg *)lyr3h;
320 if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
321 i6addr = &ndmh->target;
322 addr = ipvlan_ht_addr_lookup(port, i6addr, true);
323 }
324 } else if (addr_type == IPVL_IPV4) {
325 struct iphdr *ip4h;
326 __be32 *i4addr;
327
328 ip4h = (struct iphdr *)lyr3h;
329 i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
330 addr = ipvlan_ht_addr_lookup(port, i4addr, false);
331 } else if (addr_type == IPVL_ARP) {
332 struct arphdr *arph;
333 unsigned char *arp_ptr;
334 __be32 dip;
335
336 arph = (struct arphdr *)lyr3h;
337 arp_ptr = (unsigned char *)(arph + 1);
338 if (use_dest)
339 arp_ptr += (2 * port->dev->addr_len) + 4;
340 else
341 arp_ptr += port->dev->addr_len;
342
343 memcpy(&dip, arp_ptr, 4);
344 addr = ipvlan_ht_addr_lookup(port, &dip, false);
345 }
346
347 return addr;
348}
349
350static int ipvlan_process_v4_outbound(struct sk_buff *skb, bool xnet)
351{
352 const struct iphdr *ip4h = ip_hdr(skb);
353 struct net_device *dev = skb->dev;
354 struct net *net = dev_net(dev);
355 struct rtable *rt;
356 int err, ret = NET_XMIT_DROP;
357 struct flowi4 fl4 = {
358 .flowi4_oif = dev->ifindex,
359 .flowi4_tos = RT_TOS(ip4h->tos),
360 .flowi4_flags = FLOWI_FLAG_ANYSRC,
361 .daddr = ip4h->daddr,
362 .saddr = ip4h->saddr,
363 };
364
365 rt = ip_route_output_flow(net, &fl4, NULL);
366 if (IS_ERR(rt))
367 goto err;
368
369 if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
370 ip_rt_put(rt);
371 goto err;
372 }
373 skb_scrub_packet(skb, xnet);
374 skb_dst_set(skb, &rt->dst);
375 err = ip_local_out(net, skb->sk, skb);
376 if (unlikely(net_xmit_eval(err)))
377 dev->stats.tx_errors++;
378 else
379 ret = NET_XMIT_SUCCESS;
380 goto out;
381err:
382 dev->stats.tx_errors++;
383 kfree_skb(skb);
384out:
385 return ret;
386}
387
388static int ipvlan_process_v6_outbound(struct sk_buff *skb, bool xnet)
389{
390 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
391 struct net_device *dev = skb->dev;
392 struct net *net = dev_net(dev);
393 struct dst_entry *dst;
394 int err, ret = NET_XMIT_DROP;
395 struct flowi6 fl6 = {
396 .flowi6_iif = dev->ifindex,
397 .daddr = ip6h->daddr,
398 .saddr = ip6h->saddr,
399 .flowi6_flags = FLOWI_FLAG_ANYSRC,
400 .flowlabel = ip6_flowinfo(ip6h),
401 .flowi6_mark = skb->mark,
402 .flowi6_proto = ip6h->nexthdr,
403 };
404
405 dst = ip6_route_output(net, NULL, &fl6);
406 if (dst->error) {
407 ret = dst->error;
408 dst_release(dst);
409 goto err;
410 }
411 skb_scrub_packet(skb, xnet);
412 skb_dst_set(skb, dst);
413 err = ip6_local_out(net, skb->sk, skb);
414 if (unlikely(net_xmit_eval(err)))
415 dev->stats.tx_errors++;
416 else
417 ret = NET_XMIT_SUCCESS;
418 goto out;
419err:
420 dev->stats.tx_errors++;
421 kfree_skb(skb);
422out:
423 return ret;
424}
425
426static int ipvlan_process_outbound(struct sk_buff *skb, bool xnet)
427{
428 struct ethhdr *ethh = eth_hdr(skb);
429 int ret = NET_XMIT_DROP;
430
431 /* In this mode we dont care about multicast and broadcast traffic */
432 if (is_multicast_ether_addr(ethh->h_dest)) {
433 pr_warn_ratelimited("Dropped {multi|broad}cast of type= [%x]\n",
434 ntohs(skb->protocol));
435 kfree_skb(skb);
436 goto out;
437 }
438
439 /* The ipvlan is a pseudo-L2 device, so the packets that we receive
440 * will have L2; which need to discarded and processed further
441 * in the net-ns of the main-device.
442 */
443 if (skb_mac_header_was_set(skb)) {
444 skb_pull(skb, sizeof(*ethh));
445 skb->mac_header = (typeof(skb->mac_header))~0U;
446 skb_reset_network_header(skb);
447 }
448
449 if (skb->protocol == htons(ETH_P_IPV6))
450 ret = ipvlan_process_v6_outbound(skb, xnet);
451 else if (skb->protocol == htons(ETH_P_IP))
452 ret = ipvlan_process_v4_outbound(skb, xnet);
453 else {
454 pr_warn_ratelimited("Dropped outbound packet type=%x\n",
455 ntohs(skb->protocol));
456 kfree_skb(skb);
457 }
458out:
459 return ret;
460}
461
462static void ipvlan_multicast_enqueue(struct ipvl_port *port,
463 struct sk_buff *skb)
464{
465 if (skb->protocol == htons(ETH_P_PAUSE)) {
466 kfree_skb(skb);
467 return;
468 }
469
470 spin_lock(&port->backlog.lock);
471 if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
472 __skb_queue_tail(&port->backlog, skb);
473 spin_unlock(&port->backlog.lock);
474 schedule_work(&port->wq);
475 } else {
476 spin_unlock(&port->backlog.lock);
477 atomic_long_inc(&skb->dev->rx_dropped);
478 kfree_skb(skb);
479 }
480}
481
482static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
483{
484 const struct ipvl_dev *ipvlan = netdev_priv(dev);
485 void *lyr3h;
486 struct ipvl_addr *addr;
487 int addr_type;
488 bool xnet;
489
490 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
491 if (!lyr3h)
492 goto out;
493
494 addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
495 if (addr)
496 return ipvlan_rcv_frame(addr, &skb, true);
497
498out:
499 xnet = !net_eq(dev_net(skb->dev), dev_net(ipvlan->phy_dev));
500 skb->dev = ipvlan->phy_dev;
501 return ipvlan_process_outbound(skb, xnet);
502}
503
504static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
505{
506 const struct ipvl_dev *ipvlan = netdev_priv(dev);
507 struct ethhdr *eth = eth_hdr(skb);
508 struct ipvl_addr *addr;
509 void *lyr3h;
510 int addr_type;
511
512 if (ether_addr_equal(eth->h_dest, eth->h_source)) {
513 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
514 if (lyr3h) {
515 addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
516 if (addr)
517 return ipvlan_rcv_frame(addr, &skb, true);
518 }
519 skb = skb_share_check(skb, GFP_ATOMIC);
520 if (!skb)
521 return NET_XMIT_DROP;
522
523 /* Packet definitely does not belong to any of the
524 * virtual devices, but the dest is local. So forward
525 * the skb for the main-dev. At the RX side we just return
526 * RX_PASS for it to be processed further on the stack.
527 */
528 return dev_forward_skb(ipvlan->phy_dev, skb);
529
530 } else if (is_multicast_ether_addr(eth->h_dest)) {
531 ipvlan_multicast_enqueue(ipvlan->port, skb);
532 return NET_XMIT_SUCCESS;
533 }
534
535 skb->dev = ipvlan->phy_dev;
536 return dev_queue_xmit(skb);
537}
538
539int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
540{
541 struct ipvl_dev *ipvlan = netdev_priv(dev);
542 struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);
543
544 if (!port)
545 goto out;
546
547 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
548 goto out;
549
550 switch(port->mode) {
551 case IPVLAN_MODE_L2:
552 return ipvlan_xmit_mode_l2(skb, dev);
553 case IPVLAN_MODE_L3:
554 return ipvlan_xmit_mode_l3(skb, dev);
555 }
556
557 /* Should not reach here */
558 WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
559 port->mode);
560out:
561 kfree_skb(skb);
562 return NET_XMIT_DROP;
563}
564
565static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
566{
567 struct ethhdr *eth = eth_hdr(skb);
568 struct ipvl_addr *addr;
569 void *lyr3h;
570 int addr_type;
571
572 if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
573 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
574 if (!lyr3h)
575 return true;
576
577 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
578 if (addr)
579 return false;
580 }
581
582 return true;
583}
584
585static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
586 struct ipvl_port *port)
587{
588 void *lyr3h;
589 int addr_type;
590 struct ipvl_addr *addr;
591 struct sk_buff *skb = *pskb;
592 rx_handler_result_t ret = RX_HANDLER_PASS;
593
594 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
595 if (!lyr3h)
596 goto out;
597
598 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
599 if (addr)
600 ret = ipvlan_rcv_frame(addr, pskb, false);
601
602out:
603 return ret;
604}
605
606static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
607 struct ipvl_port *port)
608{
609 struct sk_buff *skb = *pskb;
610 struct ethhdr *eth = eth_hdr(skb);
611 rx_handler_result_t ret = RX_HANDLER_PASS;
612 void *lyr3h;
613 int addr_type;
614
615 if (is_multicast_ether_addr(eth->h_dest)) {
616 if (ipvlan_external_frame(skb, port)) {
617 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
618
619 /* External frames are queued for device local
620 * distribution, but a copy is given to master
621 * straight away to avoid sending duplicates later
622 * when work-queue processes this frame. This is
623 * achieved by returning RX_HANDLER_PASS.
624 */
625 if (nskb)
626 ipvlan_multicast_enqueue(port, nskb);
627 }
628 } else {
629 struct ipvl_addr *addr;
630
631 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
632 if (!lyr3h)
633 return ret;
634
635 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
636 if (addr)
637 ret = ipvlan_rcv_frame(addr, pskb, false);
638 }
639
640 return ret;
641}
642
643rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
644{
645 struct sk_buff *skb = *pskb;
646 struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
647
648 if (!port)
649 return RX_HANDLER_PASS;
650
651 switch (port->mode) {
652 case IPVLAN_MODE_L2:
653 return ipvlan_handle_mode_l2(pskb, port);
654 case IPVLAN_MODE_L3:
655 return ipvlan_handle_mode_l3(pskb, port);
656 }
657
658 /* Should not reach here */
659 WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
660 port->mode);
661 kfree_skb(skb);
662 return RX_HANDLER_CONSUMED;
663}