2 * vrf.c: device driver to encapsulate a VRF space
4 * Copyright (c) 2015 Cumulus Networks. All rights reserved.
5 * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com>
6 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
8 * Based on dummy, team and ipvlan drivers
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
21 #include <linux/init.h>
22 #include <linux/moduleparam.h>
23 #include <linux/netfilter.h>
24 #include <linux/rtnetlink.h>
25 #include <net/rtnetlink.h>
26 #include <linux/u64_stats_sync.h>
27 #include <linux/hashtable.h>
29 #include <linux/inetdevice.h>
32 #include <net/ip_fib.h>
33 #include <net/ip6_route.h>
34 #include <net/rtnetlink.h>
35 #include <net/route.h>
36 #include <net/addrconf.h>
37 #include <net/l3mdev.h>
39 #define RT_FL_TOS(oldflp4) \
40 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
42 #define DRV_NAME "vrf"
43 #define DRV_VERSION "1.0"
45 #define vrf_master_get_rcu(dev) \
46 ((struct net_device *)rcu_dereference(dev->rx_handler_data))
49 struct list_head list
;
50 struct net_device
*dev
;
54 struct list_head all_slaves
;
58 struct slave_queue queue
;
69 struct u64_stats_sync syncp
;
72 static struct dst_entry
*vrf_ip_check(struct dst_entry
*dst
, u32 cookie
)
77 static int vrf_ip_local_out(struct sk_buff
*skb
)
79 return ip_local_out(skb
);
82 static unsigned int vrf_v4_mtu(const struct dst_entry
*dst
)
84 /* TO-DO: return max ethernet size? */
88 static void vrf_dst_destroy(struct dst_entry
*dst
)
90 /* our dst lives forever - or until the device is closed */
93 static unsigned int vrf_default_advmss(const struct dst_entry
*dst
)
98 static struct dst_ops vrf_dst_ops
= {
100 .local_out
= vrf_ip_local_out
,
101 .check
= vrf_ip_check
,
103 .destroy
= vrf_dst_destroy
,
104 .default_advmss
= vrf_default_advmss
,
107 static bool is_ip_rx_frame(struct sk_buff
*skb
)
109 switch (skb
->protocol
) {
110 case htons(ETH_P_IP
):
111 case htons(ETH_P_IPV6
):
117 static void vrf_tx_error(struct net_device
*vrf_dev
, struct sk_buff
*skb
)
119 vrf_dev
->stats
.tx_errors
++;
123 /* note: already called with rcu_read_lock */
124 static rx_handler_result_t
vrf_handle_frame(struct sk_buff
**pskb
)
126 struct sk_buff
*skb
= *pskb
;
128 if (is_ip_rx_frame(skb
)) {
129 struct net_device
*dev
= vrf_master_get_rcu(skb
->dev
);
130 struct pcpu_dstats
*dstats
= this_cpu_ptr(dev
->dstats
);
132 u64_stats_update_begin(&dstats
->syncp
);
134 dstats
->rx_bytes
+= skb
->len
;
135 u64_stats_update_end(&dstats
->syncp
);
139 return RX_HANDLER_ANOTHER
;
141 return RX_HANDLER_PASS
;
144 static struct rtnl_link_stats64
*vrf_get_stats64(struct net_device
*dev
,
145 struct rtnl_link_stats64
*stats
)
149 for_each_possible_cpu(i
) {
150 const struct pcpu_dstats
*dstats
;
151 u64 tbytes
, tpkts
, tdrops
, rbytes
, rpkts
;
154 dstats
= per_cpu_ptr(dev
->dstats
, i
);
156 start
= u64_stats_fetch_begin_irq(&dstats
->syncp
);
157 tbytes
= dstats
->tx_bytes
;
158 tpkts
= dstats
->tx_pkts
;
159 tdrops
= dstats
->tx_drps
;
160 rbytes
= dstats
->rx_bytes
;
161 rpkts
= dstats
->rx_pkts
;
162 } while (u64_stats_fetch_retry_irq(&dstats
->syncp
, start
));
163 stats
->tx_bytes
+= tbytes
;
164 stats
->tx_packets
+= tpkts
;
165 stats
->tx_dropped
+= tdrops
;
166 stats
->rx_bytes
+= rbytes
;
167 stats
->rx_packets
+= rpkts
;
172 static netdev_tx_t
vrf_process_v6_outbound(struct sk_buff
*skb
,
173 struct net_device
*dev
)
175 vrf_tx_error(dev
, skb
);
176 return NET_XMIT_DROP
;
179 static int vrf_send_v4_prep(struct sk_buff
*skb
, struct flowi4
*fl4
,
180 struct net_device
*vrf_dev
)
185 rt
= ip_route_output_flow(dev_net(vrf_dev
), fl4
, NULL
);
189 /* TO-DO: what about broadcast ? */
190 if (rt
->rt_type
!= RTN_UNICAST
&& rt
->rt_type
!= RTN_LOCAL
) {
196 skb_dst_set(skb
, &rt
->dst
);
202 static netdev_tx_t
vrf_process_v4_outbound(struct sk_buff
*skb
,
203 struct net_device
*vrf_dev
)
205 struct iphdr
*ip4h
= ip_hdr(skb
);
206 int ret
= NET_XMIT_DROP
;
207 struct flowi4 fl4
= {
208 /* needed to match OIF rule */
209 .flowi4_oif
= vrf_dev
->ifindex
,
210 .flowi4_iif
= LOOPBACK_IFINDEX
,
211 .flowi4_tos
= RT_TOS(ip4h
->tos
),
212 .flowi4_flags
= FLOWI_FLAG_ANYSRC
| FLOWI_FLAG_L3MDEV_SRC
|
213 FLOWI_FLAG_SKIP_NH_OIF
,
214 .daddr
= ip4h
->daddr
,
217 if (vrf_send_v4_prep(skb
, &fl4
, vrf_dev
))
221 ip4h
->saddr
= inet_select_addr(skb_dst(skb
)->dev
, 0,
225 ret
= ip_local_out(skb
);
226 if (unlikely(net_xmit_eval(ret
)))
227 vrf_dev
->stats
.tx_errors
++;
229 ret
= NET_XMIT_SUCCESS
;
234 vrf_tx_error(vrf_dev
, skb
);
238 static netdev_tx_t
is_ip_tx_frame(struct sk_buff
*skb
, struct net_device
*dev
)
240 /* strip the ethernet header added for pass through VRF device */
241 __skb_pull(skb
, skb_network_offset(skb
));
243 switch (skb
->protocol
) {
244 case htons(ETH_P_IP
):
245 return vrf_process_v4_outbound(skb
, dev
);
246 case htons(ETH_P_IPV6
):
247 return vrf_process_v6_outbound(skb
, dev
);
249 vrf_tx_error(dev
, skb
);
250 return NET_XMIT_DROP
;
254 static netdev_tx_t
vrf_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
256 netdev_tx_t ret
= is_ip_tx_frame(skb
, dev
);
258 if (likely(ret
== NET_XMIT_SUCCESS
|| ret
== NET_XMIT_CN
)) {
259 struct pcpu_dstats
*dstats
= this_cpu_ptr(dev
->dstats
);
261 u64_stats_update_begin(&dstats
->syncp
);
263 dstats
->tx_bytes
+= skb
->len
;
264 u64_stats_update_end(&dstats
->syncp
);
266 this_cpu_inc(dev
->dstats
->tx_drps
);
272 /* modelled after ip_finish_output2 */
273 static int vrf_finish_output(struct net
*net
, struct sock
*sk
, struct sk_buff
*skb
)
275 struct dst_entry
*dst
= skb_dst(skb
);
276 struct rtable
*rt
= (struct rtable
*)dst
;
277 struct net_device
*dev
= dst
->dev
;
278 unsigned int hh_len
= LL_RESERVED_SPACE(dev
);
279 struct neighbour
*neigh
;
283 /* Be paranoid, rather than too clever. */
284 if (unlikely(skb_headroom(skb
) < hh_len
&& dev
->header_ops
)) {
285 struct sk_buff
*skb2
;
287 skb2
= skb_realloc_headroom(skb
, LL_RESERVED_SPACE(dev
));
293 skb_set_owner_w(skb2
, skb
->sk
);
301 nexthop
= (__force u32
)rt_nexthop(rt
, ip_hdr(skb
)->daddr
);
302 neigh
= __ipv4_neigh_lookup_noref(dev
, nexthop
);
303 if (unlikely(!neigh
))
304 neigh
= __neigh_create(&arp_tbl
, &nexthop
, dev
, false);
306 ret
= dst_neigh_output(dst
, neigh
, skb
);
308 rcu_read_unlock_bh();
310 if (unlikely(ret
< 0))
311 vrf_tx_error(skb
->dev
, skb
);
315 static int vrf_output(struct sock
*sk
, struct sk_buff
*skb
)
317 struct net_device
*dev
= skb_dst(skb
)->dev
;
318 struct net
*net
= dev_net(dev
);
320 IP_UPD_PO_STATS(net
, IPSTATS_MIB_OUT
, skb
->len
);
323 skb
->protocol
= htons(ETH_P_IP
);
325 return NF_HOOK_COND(NFPROTO_IPV4
, NF_INET_POST_ROUTING
,
326 net
, sk
, skb
, NULL
, dev
,
328 !(IPCB(skb
)->flags
& IPSKB_REROUTED
));
331 static void vrf_rtable_destroy(struct net_vrf
*vrf
)
333 struct dst_entry
*dst
= (struct dst_entry
*)vrf
->rth
;
339 static struct rtable
*vrf_rtable_create(struct net_device
*dev
)
341 struct net_vrf
*vrf
= netdev_priv(dev
);
344 rth
= dst_alloc(&vrf_dst_ops
, dev
, 2,
346 (DST_HOST
| DST_NOPOLICY
| DST_NOXFRM
));
348 rth
->dst
.output
= vrf_output
;
349 rth
->rt_genid
= rt_genid_ipv4(dev_net(dev
));
351 rth
->rt_type
= RTN_UNICAST
;
352 rth
->rt_is_input
= 0;
356 rth
->rt_uses_gateway
= 0;
357 rth
->rt_table_id
= vrf
->tb_id
;
358 INIT_LIST_HEAD(&rth
->rt_uncached
);
359 rth
->rt_uncached_list
= NULL
;
365 /**************************** device handling ********************/
367 /* cycle interface to flush neighbor cache and move routes across tables */
368 static void cycle_netdev(struct net_device
*dev
)
370 unsigned int flags
= dev
->flags
;
373 if (!netif_running(dev
))
376 ret
= dev_change_flags(dev
, flags
& ~IFF_UP
);
378 ret
= dev_change_flags(dev
, flags
);
382 "Failed to cycle device %s; route tables might be wrong!\n",
387 static struct slave
*__vrf_find_slave_dev(struct slave_queue
*queue
,
388 struct net_device
*dev
)
390 struct list_head
*head
= &queue
->all_slaves
;
393 list_for_each_entry(slave
, head
, list
) {
394 if (slave
->dev
== dev
)
401 /* inverse of __vrf_insert_slave */
402 static void __vrf_remove_slave(struct slave_queue
*queue
, struct slave
*slave
)
404 list_del(&slave
->list
);
407 static void __vrf_insert_slave(struct slave_queue
*queue
, struct slave
*slave
)
409 list_add(&slave
->list
, &queue
->all_slaves
);
412 static int do_vrf_add_slave(struct net_device
*dev
, struct net_device
*port_dev
)
414 struct slave
*slave
= kzalloc(sizeof(*slave
), GFP_KERNEL
);
415 struct net_vrf
*vrf
= netdev_priv(dev
);
416 struct slave_queue
*queue
= &vrf
->queue
;
422 slave
->dev
= port_dev
;
424 /* register the packet handler for slave ports */
425 ret
= netdev_rx_handler_register(port_dev
, vrf_handle_frame
, dev
);
428 "Device %s failed to register rx_handler\n",
433 ret
= netdev_master_upper_dev_link(port_dev
, dev
);
437 port_dev
->priv_flags
|= IFF_L3MDEV_SLAVE
;
438 __vrf_insert_slave(queue
, slave
);
439 cycle_netdev(port_dev
);
444 netdev_rx_handler_unregister(port_dev
);
450 static int vrf_add_slave(struct net_device
*dev
, struct net_device
*port_dev
)
452 if (netif_is_l3_master(port_dev
) || netif_is_l3_slave(port_dev
))
455 return do_vrf_add_slave(dev
, port_dev
);
458 /* inverse of do_vrf_add_slave */
459 static int do_vrf_del_slave(struct net_device
*dev
, struct net_device
*port_dev
)
461 struct net_vrf
*vrf
= netdev_priv(dev
);
462 struct slave_queue
*queue
= &vrf
->queue
;
465 netdev_upper_dev_unlink(port_dev
, dev
);
466 port_dev
->priv_flags
&= ~IFF_L3MDEV_SLAVE
;
468 netdev_rx_handler_unregister(port_dev
);
470 cycle_netdev(port_dev
);
472 slave
= __vrf_find_slave_dev(queue
, port_dev
);
474 __vrf_remove_slave(queue
, slave
);
481 static int vrf_del_slave(struct net_device
*dev
, struct net_device
*port_dev
)
483 return do_vrf_del_slave(dev
, port_dev
);
486 static void vrf_dev_uninit(struct net_device
*dev
)
488 struct net_vrf
*vrf
= netdev_priv(dev
);
489 struct slave_queue
*queue
= &vrf
->queue
;
490 struct list_head
*head
= &queue
->all_slaves
;
491 struct slave
*slave
, *next
;
493 vrf_rtable_destroy(vrf
);
495 list_for_each_entry_safe(slave
, next
, head
, list
)
496 vrf_del_slave(dev
, slave
->dev
);
498 free_percpu(dev
->dstats
);
502 static int vrf_dev_init(struct net_device
*dev
)
504 struct net_vrf
*vrf
= netdev_priv(dev
);
506 INIT_LIST_HEAD(&vrf
->queue
.all_slaves
);
508 dev
->dstats
= netdev_alloc_pcpu_stats(struct pcpu_dstats
);
512 /* create the default dst which points back to us */
513 vrf
->rth
= vrf_rtable_create(dev
);
517 dev
->flags
= IFF_MASTER
| IFF_NOARP
;
522 free_percpu(dev
->dstats
);
528 static const struct net_device_ops vrf_netdev_ops
= {
529 .ndo_init
= vrf_dev_init
,
530 .ndo_uninit
= vrf_dev_uninit
,
531 .ndo_start_xmit
= vrf_xmit
,
532 .ndo_get_stats64
= vrf_get_stats64
,
533 .ndo_add_slave
= vrf_add_slave
,
534 .ndo_del_slave
= vrf_del_slave
,
537 static u32
vrf_fib_table(const struct net_device
*dev
)
539 struct net_vrf
*vrf
= netdev_priv(dev
);
544 static struct rtable
*vrf_get_rtable(const struct net_device
*dev
,
545 const struct flowi4
*fl4
)
547 struct rtable
*rth
= NULL
;
549 if (!(fl4
->flowi4_flags
& FLOWI_FLAG_L3MDEV_SRC
)) {
550 struct net_vrf
*vrf
= netdev_priv(dev
);
553 atomic_inc(&rth
->dst
.__refcnt
);
559 /* called under rcu_read_lock */
560 static void vrf_get_saddr(struct net_device
*dev
, struct flowi4
*fl4
)
562 struct fib_result res
= { .tclassid
= 0 };
563 struct net
*net
= dev_net(dev
);
564 u32 orig_tos
= fl4
->flowi4_tos
;
565 u8 flags
= fl4
->flowi4_flags
;
566 u8 scope
= fl4
->flowi4_scope
;
567 u8 tos
= RT_FL_TOS(fl4
);
569 if (unlikely(!fl4
->daddr
))
572 fl4
->flowi4_flags
|= FLOWI_FLAG_SKIP_NH_OIF
;
573 fl4
->flowi4_iif
= LOOPBACK_IFINDEX
;
574 fl4
->flowi4_tos
= tos
& IPTOS_RT_MASK
;
575 fl4
->flowi4_scope
= ((tos
& RTO_ONLINK
) ?
576 RT_SCOPE_LINK
: RT_SCOPE_UNIVERSE
);
578 if (!fib_lookup(net
, fl4
, &res
, 0)) {
579 if (res
.type
== RTN_LOCAL
)
580 fl4
->saddr
= res
.fi
->fib_prefsrc
? : fl4
->daddr
;
582 fib_select_path(net
, &res
, fl4
, -1);
585 fl4
->flowi4_flags
= flags
;
586 fl4
->flowi4_tos
= orig_tos
;
587 fl4
->flowi4_scope
= scope
;
590 static const struct l3mdev_ops vrf_l3mdev_ops
= {
591 .l3mdev_fib_table
= vrf_fib_table
,
592 .l3mdev_get_rtable
= vrf_get_rtable
,
593 .l3mdev_get_saddr
= vrf_get_saddr
,
596 static void vrf_get_drvinfo(struct net_device
*dev
,
597 struct ethtool_drvinfo
*info
)
599 strlcpy(info
->driver
, DRV_NAME
, sizeof(info
->driver
));
600 strlcpy(info
->version
, DRV_VERSION
, sizeof(info
->version
));
603 static const struct ethtool_ops vrf_ethtool_ops
= {
604 .get_drvinfo
= vrf_get_drvinfo
,
607 static void vrf_setup(struct net_device
*dev
)
611 /* Initialize the device structure. */
612 dev
->netdev_ops
= &vrf_netdev_ops
;
613 dev
->l3mdev_ops
= &vrf_l3mdev_ops
;
614 dev
->ethtool_ops
= &vrf_ethtool_ops
;
615 dev
->destructor
= free_netdev
;
617 /* Fill in device structure with ethernet-generic values. */
618 eth_hw_addr_random(dev
);
620 /* don't acquire vrf device's netif_tx_lock when transmitting */
621 dev
->features
|= NETIF_F_LLTX
;
623 /* don't allow vrf devices to change network namespaces. */
624 dev
->features
|= NETIF_F_NETNS_LOCAL
;
627 static int vrf_validate(struct nlattr
*tb
[], struct nlattr
*data
[])
629 if (tb
[IFLA_ADDRESS
]) {
630 if (nla_len(tb
[IFLA_ADDRESS
]) != ETH_ALEN
)
632 if (!is_valid_ether_addr(nla_data(tb
[IFLA_ADDRESS
])))
633 return -EADDRNOTAVAIL
;
638 static void vrf_dellink(struct net_device
*dev
, struct list_head
*head
)
640 unregister_netdevice_queue(dev
, head
);
643 static int vrf_newlink(struct net
*src_net
, struct net_device
*dev
,
644 struct nlattr
*tb
[], struct nlattr
*data
[])
646 struct net_vrf
*vrf
= netdev_priv(dev
);
649 if (!data
|| !data
[IFLA_VRF_TABLE
])
652 vrf
->tb_id
= nla_get_u32(data
[IFLA_VRF_TABLE
]);
654 dev
->priv_flags
|= IFF_L3MDEV_MASTER
;
656 err
= register_netdevice(dev
);
667 static size_t vrf_nl_getsize(const struct net_device
*dev
)
669 return nla_total_size(sizeof(u32
)); /* IFLA_VRF_TABLE */
672 static int vrf_fillinfo(struct sk_buff
*skb
,
673 const struct net_device
*dev
)
675 struct net_vrf
*vrf
= netdev_priv(dev
);
677 return nla_put_u32(skb
, IFLA_VRF_TABLE
, vrf
->tb_id
);
680 static const struct nla_policy vrf_nl_policy
[IFLA_VRF_MAX
+ 1] = {
681 [IFLA_VRF_TABLE
] = { .type
= NLA_U32
},
684 static struct rtnl_link_ops vrf_link_ops __read_mostly
= {
686 .priv_size
= sizeof(struct net_vrf
),
688 .get_size
= vrf_nl_getsize
,
689 .policy
= vrf_nl_policy
,
690 .validate
= vrf_validate
,
691 .fill_info
= vrf_fillinfo
,
693 .newlink
= vrf_newlink
,
694 .dellink
= vrf_dellink
,
696 .maxtype
= IFLA_VRF_MAX
,
699 static int vrf_device_event(struct notifier_block
*unused
,
700 unsigned long event
, void *ptr
)
702 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
704 /* only care about unregister events to drop slave references */
705 if (event
== NETDEV_UNREGISTER
) {
706 struct net_device
*vrf_dev
;
708 if (!netif_is_l3_slave(dev
))
711 vrf_dev
= netdev_master_upper_dev_get(dev
);
712 vrf_del_slave(vrf_dev
, dev
);
718 static struct notifier_block vrf_notifier_block __read_mostly
= {
719 .notifier_call
= vrf_device_event
,
722 static int __init
vrf_init_module(void)
726 vrf_dst_ops
.kmem_cachep
=
727 kmem_cache_create("vrf_ip_dst_cache",
728 sizeof(struct rtable
), 0,
732 if (!vrf_dst_ops
.kmem_cachep
)
735 register_netdevice_notifier(&vrf_notifier_block
);
737 rc
= rtnl_link_register(&vrf_link_ops
);
744 unregister_netdevice_notifier(&vrf_notifier_block
);
745 kmem_cache_destroy(vrf_dst_ops
.kmem_cachep
);
749 static void __exit
vrf_cleanup_module(void)
751 rtnl_link_unregister(&vrf_link_ops
);
752 unregister_netdevice_notifier(&vrf_notifier_block
);
753 kmem_cache_destroy(vrf_dst_ops
.kmem_cachep
);
756 module_init(vrf_init_module
);
757 module_exit(vrf_cleanup_module
);
758 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
759 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
760 MODULE_LICENSE("GPL");
761 MODULE_ALIAS_RTNL_LINK(DRV_NAME
);
762 MODULE_VERSION(DRV_VERSION
);