Linux-libre 4.4.228-gnu
[librecmc/linux-libre.git] / drivers / net / ipvlan / ipvlan_core.c
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
12 static u32 ipvlan_jhash_secret __read_mostly;
13
14 void ipvlan_init_secret(void)
15 {
16         net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
17 }
18
19 static 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
40 static 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
48 static 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
56 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
76 void 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
88 void ipvlan_ht_addr_del(struct ipvl_addr *addr)
89 {
90         hlist_del_init_rcu(&addr->hlnode);
91 }
92
93 struct 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
108 bool 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
121 static 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
182 unsigned 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
190 void 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);
241 acct:
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                 cond_resched();
255         }
256 }
257
258 static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
259                             bool local)
260 {
261         struct ipvl_dev *ipvlan = addr->master;
262         struct net_device *dev = ipvlan->dev;
263         unsigned int len;
264         rx_handler_result_t ret = RX_HANDLER_CONSUMED;
265         bool success = false;
266         struct sk_buff *skb = *pskb;
267
268         len = skb->len + ETH_HLEN;
269         if (unlikely(!(dev->flags & IFF_UP))) {
270                 kfree_skb(skb);
271                 goto out;
272         }
273
274         skb = skb_share_check(skb, GFP_ATOMIC);
275         if (!skb)
276                 goto out;
277
278         *pskb = skb;
279         skb->dev = dev;
280         skb->pkt_type = PACKET_HOST;
281
282         if (local) {
283                 if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
284                         success = true;
285         } else {
286                 if (!ether_addr_equal_64bits(eth_hdr(skb)->h_dest,
287                                              ipvlan->phy_dev->dev_addr))
288                         skb->pkt_type = PACKET_OTHERHOST;
289
290                 ret = RX_HANDLER_ANOTHER;
291                 success = true;
292         }
293
294 out:
295         ipvlan_count_rx(ipvlan, len, success, false);
296         return ret;
297 }
298
299 static 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
350 static int ipvlan_process_v4_outbound(struct sk_buff *skb)
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                 .flowi4_mark = skb->mark,
362                 .daddr = ip4h->daddr,
363                 .saddr = ip4h->saddr,
364         };
365
366         rt = ip_route_output_flow(net, &fl4, NULL);
367         if (IS_ERR(rt))
368                 goto err;
369
370         if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
371                 ip_rt_put(rt);
372                 goto err;
373         }
374         skb_dst_drop(skb);
375         skb_dst_set(skb, &rt->dst);
376         err = ip_local_out(net, skb->sk, skb);
377         if (unlikely(net_xmit_eval(err)))
378                 dev->stats.tx_errors++;
379         else
380                 ret = NET_XMIT_SUCCESS;
381         goto out;
382 err:
383         dev->stats.tx_errors++;
384         kfree_skb(skb);
385 out:
386         return ret;
387 }
388
389 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
390 {
391         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
392         struct net_device *dev = skb->dev;
393         struct net *net = dev_net(dev);
394         struct dst_entry *dst;
395         int err, ret = NET_XMIT_DROP;
396         struct flowi6 fl6 = {
397                 .flowi6_oif = dev->ifindex,
398                 .daddr = ip6h->daddr,
399                 .saddr = ip6h->saddr,
400                 .flowi6_flags = FLOWI_FLAG_ANYSRC,
401                 .flowlabel = ip6_flowinfo(ip6h),
402                 .flowi6_mark = skb->mark,
403                 .flowi6_proto = ip6h->nexthdr,
404         };
405
406         dst = ip6_route_output(net, NULL, &fl6);
407         if (dst->error) {
408                 ret = dst->error;
409                 dst_release(dst);
410                 goto err;
411         }
412         skb_dst_drop(skb);
413         skb_dst_set(skb, dst);
414         err = ip6_local_out(net, skb->sk, skb);
415         if (unlikely(net_xmit_eval(err)))
416                 dev->stats.tx_errors++;
417         else
418                 ret = NET_XMIT_SUCCESS;
419         goto out;
420 err:
421         dev->stats.tx_errors++;
422         kfree_skb(skb);
423 out:
424         return ret;
425 }
426
427 static int ipvlan_process_outbound(struct sk_buff *skb,
428                                    const struct ipvl_dev *ipvlan)
429 {
430         struct ethhdr *ethh = eth_hdr(skb);
431         int ret = NET_XMIT_DROP;
432
433         /* The ipvlan is a pseudo-L2 device, so the packets that we receive
434          * will have L2; which need to discarded and processed further
435          * in the net-ns of the main-device.
436          */
437         if (skb_mac_header_was_set(skb)) {
438                 /* In this mode we dont care about
439                  * multicast and broadcast traffic */
440                 if (is_multicast_ether_addr(ethh->h_dest)) {
441                         pr_debug_ratelimited(
442                                 "Dropped {multi|broad}cast of type=[%x]\n",
443                                 ntohs(skb->protocol));
444                         kfree_skb(skb);
445                         goto out;
446                 }
447
448                 skb_pull(skb, sizeof(*ethh));
449                 skb->mac_header = (typeof(skb->mac_header))~0U;
450                 skb_reset_network_header(skb);
451         }
452
453         if (skb->protocol == htons(ETH_P_IPV6))
454                 ret = ipvlan_process_v6_outbound(skb);
455         else if (skb->protocol == htons(ETH_P_IP))
456                 ret = ipvlan_process_v4_outbound(skb);
457         else {
458                 pr_warn_ratelimited("Dropped outbound packet type=%x\n",
459                                     ntohs(skb->protocol));
460                 kfree_skb(skb);
461         }
462 out:
463         return ret;
464 }
465
466 static void ipvlan_multicast_enqueue(struct ipvl_port *port,
467                                      struct sk_buff *skb)
468 {
469         if (skb->protocol == htons(ETH_P_PAUSE)) {
470                 kfree_skb(skb);
471                 return;
472         }
473
474         spin_lock(&port->backlog.lock);
475         if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
476                 __skb_queue_tail(&port->backlog, skb);
477                 spin_unlock(&port->backlog.lock);
478                 schedule_work(&port->wq);
479         } else {
480                 spin_unlock(&port->backlog.lock);
481                 atomic_long_inc(&skb->dev->rx_dropped);
482                 kfree_skb(skb);
483         }
484 }
485
486 static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
487 {
488         const struct ipvl_dev *ipvlan = netdev_priv(dev);
489         void *lyr3h;
490         struct ipvl_addr *addr;
491         int addr_type;
492
493         lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
494         if (!lyr3h)
495                 goto out;
496
497         addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
498         if (addr)
499                 return ipvlan_rcv_frame(addr, &skb, true);
500
501 out:
502         skb->dev = ipvlan->phy_dev;
503         return ipvlan_process_outbound(skb, ipvlan);
504 }
505
506 static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
507 {
508         const struct ipvl_dev *ipvlan = netdev_priv(dev);
509         struct ethhdr *eth = eth_hdr(skb);
510         struct ipvl_addr *addr;
511         void *lyr3h;
512         int addr_type;
513
514         if (ether_addr_equal(eth->h_dest, eth->h_source)) {
515                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
516                 if (lyr3h) {
517                         addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
518                         if (addr)
519                                 return ipvlan_rcv_frame(addr, &skb, true);
520                 }
521                 skb = skb_share_check(skb, GFP_ATOMIC);
522                 if (!skb)
523                         return NET_XMIT_DROP;
524
525                 /* Packet definitely does not belong to any of the
526                  * virtual devices, but the dest is local. So forward
527                  * the skb for the main-dev. At the RX side we just return
528                  * RX_PASS for it to be processed further on the stack.
529                  */
530                 return dev_forward_skb(ipvlan->phy_dev, skb);
531
532         } else if (is_multicast_ether_addr(eth->h_dest)) {
533                 ipvlan_multicast_enqueue(ipvlan->port, skb);
534                 return NET_XMIT_SUCCESS;
535         }
536
537         skb->dev = ipvlan->phy_dev;
538         return dev_queue_xmit(skb);
539 }
540
541 int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
542 {
543         struct ipvl_dev *ipvlan = netdev_priv(dev);
544         struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);
545
546         if (!port)
547                 goto out;
548
549         if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
550                 goto out;
551
552         switch(port->mode) {
553         case IPVLAN_MODE_L2:
554                 return ipvlan_xmit_mode_l2(skb, dev);
555         case IPVLAN_MODE_L3:
556                 return ipvlan_xmit_mode_l3(skb, dev);
557         }
558
559         /* Should not reach here */
560         WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
561                           port->mode);
562 out:
563         kfree_skb(skb);
564         return NET_XMIT_DROP;
565 }
566
567 static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
568 {
569         struct ethhdr *eth = eth_hdr(skb);
570         struct ipvl_addr *addr;
571         void *lyr3h;
572         int addr_type;
573
574         if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
575                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
576                 if (!lyr3h)
577                         return true;
578
579                 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
580                 if (addr)
581                         return false;
582         }
583
584         return true;
585 }
586
587 static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
588                                                  struct ipvl_port *port)
589 {
590         void *lyr3h;
591         int addr_type;
592         struct ipvl_addr *addr;
593         struct sk_buff *skb = *pskb;
594         rx_handler_result_t ret = RX_HANDLER_PASS;
595
596         lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
597         if (!lyr3h)
598                 goto out;
599
600         addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
601         if (addr)
602                 ret = ipvlan_rcv_frame(addr, pskb, false);
603
604 out:
605         return ret;
606 }
607
608 static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
609                                                  struct ipvl_port *port)
610 {
611         struct sk_buff *skb = *pskb;
612         struct ethhdr *eth = eth_hdr(skb);
613         rx_handler_result_t ret = RX_HANDLER_PASS;
614         void *lyr3h;
615         int addr_type;
616
617         if (is_multicast_ether_addr(eth->h_dest)) {
618                 if (ipvlan_external_frame(skb, port)) {
619                         struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
620
621                         /* External frames are queued for device local
622                          * distribution, but a copy is given to master
623                          * straight away to avoid sending duplicates later
624                          * when work-queue processes this frame. This is
625                          * achieved by returning RX_HANDLER_PASS.
626                          */
627                         if (nskb)
628                                 ipvlan_multicast_enqueue(port, nskb);
629                 }
630         } else {
631                 struct ipvl_addr *addr;
632
633                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
634                 if (!lyr3h)
635                         return ret;
636
637                 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
638                 if (addr)
639                         ret = ipvlan_rcv_frame(addr, pskb, false);
640         }
641
642         return ret;
643 }
644
645 rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
646 {
647         struct sk_buff *skb = *pskb;
648         struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
649
650         if (!port)
651                 return RX_HANDLER_PASS;
652
653         switch (port->mode) {
654         case IPVLAN_MODE_L2:
655                 return ipvlan_handle_mode_l2(pskb, port);
656         case IPVLAN_MODE_L3:
657                 return ipvlan_handle_mode_l3(pskb, port);
658         }
659
660         /* Should not reach here */
661         WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
662                           port->mode);
663         kfree_skb(skb);
664         return RX_HANDLER_CONSUMED;
665 }