• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	XFRM virtual interface
4  *
5  *	Copyright (C) 2018 secunet Security Networks AG
6  *
7  *	Author:
8  *	Steffen Klassert <steffen.klassert@secunet.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/capability.h>
13 #include <linux/errno.h>
14 #include <linux/types.h>
15 #include <linux/sockios.h>
16 #include <linux/icmp.h>
17 #include <linux/if.h>
18 #include <linux/in.h>
19 #include <linux/ip.h>
20 #include <linux/net.h>
21 #include <linux/in6.h>
22 #include <linux/netdevice.h>
23 #include <linux/if_link.h>
24 #include <linux/if_arp.h>
25 #include <linux/icmpv6.h>
26 #include <linux/init.h>
27 #include <linux/route.h>
28 #include <linux/rtnetlink.h>
29 #include <linux/netfilter_ipv6.h>
30 #include <linux/slab.h>
31 #include <linux/hash.h>
32 
33 #include <linux/uaccess.h>
34 #include <linux/atomic.h>
35 
36 #include <net/icmp.h>
37 #include <net/ip.h>
38 #include <net/ipv6.h>
39 #include <net/ip6_route.h>
40 #include <net/addrconf.h>
41 #include <net/xfrm.h>
42 #include <net/net_namespace.h>
43 #include <net/netns/generic.h>
44 #include <linux/etherdevice.h>
45 
46 static int xfrmi_dev_init(struct net_device *dev);
47 static void xfrmi_dev_setup(struct net_device *dev);
48 static struct rtnl_link_ops xfrmi_link_ops __read_mostly;
49 static unsigned int xfrmi_net_id __read_mostly;
50 
51 struct xfrmi_net {
52 	/* lists for storing interfaces in use */
53 	struct xfrm_if __rcu *xfrmi[1];
54 };
55 
56 #define for_each_xfrmi_rcu(start, xi) \
57 	for (xi = rcu_dereference(start); xi; xi = rcu_dereference(xi->next))
58 
xfrmi_lookup(struct net * net,struct xfrm_state * x)59 static struct xfrm_if *xfrmi_lookup(struct net *net, struct xfrm_state *x)
60 {
61 	struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
62 	struct xfrm_if *xi;
63 
64 	for_each_xfrmi_rcu(xfrmn->xfrmi[0], xi) {
65 		if (x->if_id == xi->p.if_id &&
66 		    (xi->dev->flags & IFF_UP))
67 			return xi;
68 	}
69 
70 	return NULL;
71 }
72 
xfrmi_decode_session(struct sk_buff * skb)73 static struct xfrm_if *xfrmi_decode_session(struct sk_buff *skb)
74 {
75 	struct xfrmi_net *xfrmn;
76 	int ifindex;
77 	struct xfrm_if *xi;
78 
79 	if (!skb->dev)
80 		return NULL;
81 
82 	xfrmn = net_generic(dev_net(skb->dev), xfrmi_net_id);
83 	ifindex = skb->dev->ifindex;
84 
85 	for_each_xfrmi_rcu(xfrmn->xfrmi[0], xi) {
86 		if (ifindex == xi->dev->ifindex &&
87 			(xi->dev->flags & IFF_UP))
88 				return xi;
89 	}
90 
91 	return NULL;
92 }
93 
xfrmi_link(struct xfrmi_net * xfrmn,struct xfrm_if * xi)94 static void xfrmi_link(struct xfrmi_net *xfrmn, struct xfrm_if *xi)
95 {
96 	struct xfrm_if __rcu **xip = &xfrmn->xfrmi[0];
97 
98 	rcu_assign_pointer(xi->next , rtnl_dereference(*xip));
99 	rcu_assign_pointer(*xip, xi);
100 }
101 
xfrmi_unlink(struct xfrmi_net * xfrmn,struct xfrm_if * xi)102 static void xfrmi_unlink(struct xfrmi_net *xfrmn, struct xfrm_if *xi)
103 {
104 	struct xfrm_if __rcu **xip;
105 	struct xfrm_if *iter;
106 
107 	for (xip = &xfrmn->xfrmi[0];
108 	     (iter = rtnl_dereference(*xip)) != NULL;
109 	     xip = &iter->next) {
110 		if (xi == iter) {
111 			rcu_assign_pointer(*xip, xi->next);
112 			break;
113 		}
114 	}
115 }
116 
xfrmi_dev_free(struct net_device * dev)117 static void xfrmi_dev_free(struct net_device *dev)
118 {
119 	free_percpu(dev->tstats);
120 }
121 
xfrmi_create2(struct net_device * dev)122 static int xfrmi_create2(struct net_device *dev)
123 {
124 	struct xfrm_if *xi = netdev_priv(dev);
125 	struct net *net = dev_net(dev);
126 	struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
127 	int err;
128 
129 	dev->rtnl_link_ops = &xfrmi_link_ops;
130 	err = register_netdevice(dev);
131 	if (err < 0)
132 		goto out;
133 
134 	strcpy(xi->p.name, dev->name);
135 
136 	dev_hold(dev);
137 	xfrmi_link(xfrmn, xi);
138 
139 	return 0;
140 
141 out:
142 	return err;
143 }
144 
xfrmi_create(struct net * net,struct xfrm_if_parms * p)145 static struct xfrm_if *xfrmi_create(struct net *net, struct xfrm_if_parms *p)
146 {
147 	struct net_device *dev;
148 	struct xfrm_if *xi;
149 	char name[IFNAMSIZ];
150 	int err;
151 
152 	if (p->name[0]) {
153 		strlcpy(name, p->name, IFNAMSIZ);
154 	} else {
155 		err = -EINVAL;
156 		goto failed;
157 	}
158 
159 	dev = alloc_netdev(sizeof(*xi), name, NET_NAME_UNKNOWN, xfrmi_dev_setup);
160 	if (!dev) {
161 		err = -EAGAIN;
162 		goto failed;
163 	}
164 
165 	dev_net_set(dev, net);
166 
167 	xi = netdev_priv(dev);
168 	xi->p = *p;
169 	xi->net = net;
170 	xi->dev = dev;
171 	xi->phydev = dev_get_by_index(net, p->link);
172 	if (!xi->phydev) {
173 		err = -ENODEV;
174 		goto failed_free;
175 	}
176 
177 	err = xfrmi_create2(dev);
178 	if (err < 0)
179 		goto failed_dev_put;
180 
181 	return xi;
182 
183 failed_dev_put:
184 	dev_put(xi->phydev);
185 failed_free:
186 	free_netdev(dev);
187 failed:
188 	return ERR_PTR(err);
189 }
190 
xfrmi_locate(struct net * net,struct xfrm_if_parms * p,int create)191 static struct xfrm_if *xfrmi_locate(struct net *net, struct xfrm_if_parms *p,
192 				   int create)
193 {
194 	struct xfrm_if __rcu **xip;
195 	struct xfrm_if *xi;
196 	struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
197 
198 	for (xip = &xfrmn->xfrmi[0];
199 	     (xi = rtnl_dereference(*xip)) != NULL;
200 	     xip = &xi->next) {
201 		if (xi->p.if_id == p->if_id) {
202 			if (create)
203 				return ERR_PTR(-EEXIST);
204 
205 			return xi;
206 		}
207 	}
208 	if (!create)
209 		return ERR_PTR(-ENODEV);
210 	return xfrmi_create(net, p);
211 }
212 
xfrmi_dev_uninit(struct net_device * dev)213 static void xfrmi_dev_uninit(struct net_device *dev)
214 {
215 	struct xfrm_if *xi = netdev_priv(dev);
216 	struct xfrmi_net *xfrmn = net_generic(xi->net, xfrmi_net_id);
217 
218 	xfrmi_unlink(xfrmn, xi);
219 	dev_put(xi->phydev);
220 	dev_put(dev);
221 }
222 
xfrmi_scrub_packet(struct sk_buff * skb,bool xnet)223 static void xfrmi_scrub_packet(struct sk_buff *skb, bool xnet)
224 {
225 	skb->tstamp = 0;
226 	skb->pkt_type = PACKET_HOST;
227 	skb->skb_iif = 0;
228 	skb->ignore_df = 0;
229 	skb_dst_drop(skb);
230 	nf_reset(skb);
231 	nf_reset_trace(skb);
232 
233 	if (!xnet)
234 		return;
235 
236 	ipvs_reset(skb);
237 	secpath_reset(skb);
238 	skb_orphan(skb);
239 	skb->mark = 0;
240 }
241 
xfrmi_rcv_cb(struct sk_buff * skb,int err)242 static int xfrmi_rcv_cb(struct sk_buff *skb, int err)
243 {
244 	struct pcpu_sw_netstats *tstats;
245 	struct xfrm_mode *inner_mode;
246 	struct net_device *dev;
247 	struct xfrm_state *x;
248 	struct xfrm_if *xi;
249 	bool xnet;
250 
251 	if (err && !skb->sp)
252 		return 0;
253 
254 	x = xfrm_input_state(skb);
255 
256 	xi = xfrmi_lookup(xs_net(x), x);
257 	if (!xi)
258 		return 1;
259 
260 	dev = xi->dev;
261 	skb->dev = dev;
262 
263 	if (err) {
264 		dev->stats.rx_errors++;
265 		dev->stats.rx_dropped++;
266 
267 		return 0;
268 	}
269 
270 	xnet = !net_eq(xi->net, dev_net(skb->dev));
271 
272 	if (xnet) {
273 		inner_mode = x->inner_mode;
274 
275 		if (x->sel.family == AF_UNSPEC) {
276 			inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
277 			if (inner_mode == NULL) {
278 				XFRM_INC_STATS(dev_net(skb->dev),
279 					       LINUX_MIB_XFRMINSTATEMODEERROR);
280 				return -EINVAL;
281 			}
282 		}
283 
284 		if (!xfrm_policy_check(NULL, XFRM_POLICY_IN, skb,
285 				       inner_mode->afinfo->family))
286 			return -EPERM;
287 	}
288 
289 	xfrmi_scrub_packet(skb, xnet);
290 
291 	tstats = this_cpu_ptr(dev->tstats);
292 
293 	u64_stats_update_begin(&tstats->syncp);
294 	tstats->rx_packets++;
295 	tstats->rx_bytes += skb->len;
296 	u64_stats_update_end(&tstats->syncp);
297 
298 	return 0;
299 }
300 
301 static int
xfrmi_xmit2(struct sk_buff * skb,struct net_device * dev,struct flowi * fl)302 xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
303 {
304 	struct xfrm_if *xi = netdev_priv(dev);
305 	struct net_device_stats *stats = &xi->dev->stats;
306 	struct dst_entry *dst = skb_dst(skb);
307 	unsigned int length = skb->len;
308 	struct net_device *tdev;
309 	struct xfrm_state *x;
310 	int err = -1;
311 	int mtu;
312 
313 	if (!dst)
314 		goto tx_err_link_failure;
315 
316 	dst_hold(dst);
317 	dst = xfrm_lookup_with_ifid(xi->net, dst, fl, NULL, 0, xi->p.if_id);
318 	if (IS_ERR(dst)) {
319 		err = PTR_ERR(dst);
320 		dst = NULL;
321 		goto tx_err_link_failure;
322 	}
323 
324 	x = dst->xfrm;
325 	if (!x)
326 		goto tx_err_link_failure;
327 
328 	if (x->if_id != xi->p.if_id)
329 		goto tx_err_link_failure;
330 
331 	tdev = dst->dev;
332 
333 	if (tdev == dev) {
334 		stats->collisions++;
335 		net_warn_ratelimited("%s: Local routing loop detected!\n",
336 				     xi->p.name);
337 		goto tx_err_dst_release;
338 	}
339 
340 	mtu = dst_mtu(dst);
341 	if (!skb->ignore_df && skb->len > mtu) {
342 		skb_dst_update_pmtu(skb, mtu);
343 
344 		if (skb->protocol == htons(ETH_P_IPV6)) {
345 			if (mtu < IPV6_MIN_MTU)
346 				mtu = IPV6_MIN_MTU;
347 
348 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
349 		} else {
350 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
351 				  htonl(mtu));
352 		}
353 
354 		dst_release(dst);
355 		return -EMSGSIZE;
356 	}
357 
358 	xfrmi_scrub_packet(skb, !net_eq(xi->net, dev_net(dev)));
359 	skb_dst_set(skb, dst);
360 	skb->dev = tdev;
361 
362 	err = dst_output(xi->net, skb->sk, skb);
363 	if (net_xmit_eval(err) == 0) {
364 		struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);
365 
366 		u64_stats_update_begin(&tstats->syncp);
367 		tstats->tx_bytes += length;
368 		tstats->tx_packets++;
369 		u64_stats_update_end(&tstats->syncp);
370 	} else {
371 		stats->tx_errors++;
372 		stats->tx_aborted_errors++;
373 	}
374 
375 	return 0;
376 tx_err_link_failure:
377 	stats->tx_carrier_errors++;
378 	dst_link_failure(skb);
379 tx_err_dst_release:
380 	dst_release(dst);
381 	return err;
382 }
383 
xfrmi_xmit(struct sk_buff * skb,struct net_device * dev)384 static netdev_tx_t xfrmi_xmit(struct sk_buff *skb, struct net_device *dev)
385 {
386 	struct xfrm_if *xi = netdev_priv(dev);
387 	struct net_device_stats *stats = &xi->dev->stats;
388 	struct flowi fl;
389 	int ret;
390 
391 	memset(&fl, 0, sizeof(fl));
392 
393 	switch (skb->protocol) {
394 	case htons(ETH_P_IPV6):
395 		xfrm_decode_session(skb, &fl, AF_INET6);
396 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
397 		break;
398 	case htons(ETH_P_IP):
399 		xfrm_decode_session(skb, &fl, AF_INET);
400 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
401 		break;
402 	default:
403 		goto tx_err;
404 	}
405 
406 	fl.flowi_oif = xi->phydev->ifindex;
407 
408 	ret = xfrmi_xmit2(skb, dev, &fl);
409 	if (ret < 0)
410 		goto tx_err;
411 
412 	return NETDEV_TX_OK;
413 
414 tx_err:
415 	stats->tx_errors++;
416 	stats->tx_dropped++;
417 	kfree_skb(skb);
418 	return NETDEV_TX_OK;
419 }
420 
xfrmi4_err(struct sk_buff * skb,u32 info)421 static int xfrmi4_err(struct sk_buff *skb, u32 info)
422 {
423 	const struct iphdr *iph = (const struct iphdr *)skb->data;
424 	struct net *net = dev_net(skb->dev);
425 	int protocol = iph->protocol;
426 	struct ip_comp_hdr *ipch;
427 	struct ip_esp_hdr *esph;
428 	struct ip_auth_hdr *ah ;
429 	struct xfrm_state *x;
430 	struct xfrm_if *xi;
431 	__be32 spi;
432 
433 	switch (protocol) {
434 	case IPPROTO_ESP:
435 		esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
436 		spi = esph->spi;
437 		break;
438 	case IPPROTO_AH:
439 		ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
440 		spi = ah->spi;
441 		break;
442 	case IPPROTO_COMP:
443 		ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
444 		spi = htonl(ntohs(ipch->cpi));
445 		break;
446 	default:
447 		return 0;
448 	}
449 
450 	switch (icmp_hdr(skb)->type) {
451 	case ICMP_DEST_UNREACH:
452 		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
453 			return 0;
454 	case ICMP_REDIRECT:
455 		break;
456 	default:
457 		return 0;
458 	}
459 
460 	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
461 			      spi, protocol, AF_INET);
462 	if (!x)
463 		return 0;
464 
465 	xi = xfrmi_lookup(net, x);
466 	if (!xi) {
467 		xfrm_state_put(x);
468 		return -1;
469 	}
470 
471 	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
472 		ipv4_update_pmtu(skb, net, info, 0, 0, protocol, 0);
473 	else
474 		ipv4_redirect(skb, net, 0, 0, protocol, 0);
475 	xfrm_state_put(x);
476 
477 	return 0;
478 }
479 
xfrmi6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)480 static int xfrmi6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
481 		    u8 type, u8 code, int offset, __be32 info)
482 {
483 	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
484 	struct net *net = dev_net(skb->dev);
485 	int protocol = iph->nexthdr;
486 	struct ip_comp_hdr *ipch;
487 	struct ip_esp_hdr *esph;
488 	struct ip_auth_hdr *ah;
489 	struct xfrm_state *x;
490 	struct xfrm_if *xi;
491 	__be32 spi;
492 
493 	switch (protocol) {
494 	case IPPROTO_ESP:
495 		esph = (struct ip_esp_hdr *)(skb->data + offset);
496 		spi = esph->spi;
497 		break;
498 	case IPPROTO_AH:
499 		ah = (struct ip_auth_hdr *)(skb->data + offset);
500 		spi = ah->spi;
501 		break;
502 	case IPPROTO_COMP:
503 		ipch = (struct ip_comp_hdr *)(skb->data + offset);
504 		spi = htonl(ntohs(ipch->cpi));
505 		break;
506 	default:
507 		return 0;
508 	}
509 
510 	if (type != ICMPV6_PKT_TOOBIG &&
511 	    type != NDISC_REDIRECT)
512 		return 0;
513 
514 	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
515 			      spi, protocol, AF_INET6);
516 	if (!x)
517 		return 0;
518 
519 	xi = xfrmi_lookup(net, x);
520 	if (!xi) {
521 		xfrm_state_put(x);
522 		return -1;
523 	}
524 
525 	if (type == NDISC_REDIRECT)
526 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
527 			     sock_net_uid(net, NULL));
528 	else
529 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
530 	xfrm_state_put(x);
531 
532 	return 0;
533 }
534 
xfrmi_change(struct xfrm_if * xi,const struct xfrm_if_parms * p)535 static int xfrmi_change(struct xfrm_if *xi, const struct xfrm_if_parms *p)
536 {
537 	if (xi->p.link != p->link)
538 		return -EINVAL;
539 
540 	xi->p.if_id = p->if_id;
541 
542 	return 0;
543 }
544 
xfrmi_update(struct xfrm_if * xi,struct xfrm_if_parms * p)545 static int xfrmi_update(struct xfrm_if *xi, struct xfrm_if_parms *p)
546 {
547 	struct net *net = dev_net(xi->dev);
548 	struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
549 	int err;
550 
551 	xfrmi_unlink(xfrmn, xi);
552 	synchronize_net();
553 	err = xfrmi_change(xi, p);
554 	xfrmi_link(xfrmn, xi);
555 	netdev_state_change(xi->dev);
556 	return err;
557 }
558 
xfrmi_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * s)559 static void xfrmi_get_stats64(struct net_device *dev,
560 			       struct rtnl_link_stats64 *s)
561 {
562 	int cpu;
563 
564 	if (!dev->tstats)
565 		return;
566 
567 	for_each_possible_cpu(cpu) {
568 		struct pcpu_sw_netstats *stats;
569 		struct pcpu_sw_netstats tmp;
570 		int start;
571 
572 		stats = per_cpu_ptr(dev->tstats, cpu);
573 		do {
574 			start = u64_stats_fetch_begin_irq(&stats->syncp);
575 			tmp.rx_packets = stats->rx_packets;
576 			tmp.rx_bytes   = stats->rx_bytes;
577 			tmp.tx_packets = stats->tx_packets;
578 			tmp.tx_bytes   = stats->tx_bytes;
579 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
580 
581 		s->rx_packets += tmp.rx_packets;
582 		s->rx_bytes   += tmp.rx_bytes;
583 		s->tx_packets += tmp.tx_packets;
584 		s->tx_bytes   += tmp.tx_bytes;
585 	}
586 
587 	s->rx_dropped = dev->stats.rx_dropped;
588 	s->tx_dropped = dev->stats.tx_dropped;
589 }
590 
xfrmi_get_iflink(const struct net_device * dev)591 static int xfrmi_get_iflink(const struct net_device *dev)
592 {
593 	struct xfrm_if *xi = netdev_priv(dev);
594 
595 	return xi->phydev->ifindex;
596 }
597 
598 
599 static const struct net_device_ops xfrmi_netdev_ops = {
600 	.ndo_init	= xfrmi_dev_init,
601 	.ndo_uninit	= xfrmi_dev_uninit,
602 	.ndo_start_xmit = xfrmi_xmit,
603 	.ndo_get_stats64 = xfrmi_get_stats64,
604 	.ndo_get_iflink = xfrmi_get_iflink,
605 };
606 
xfrmi_dev_setup(struct net_device * dev)607 static void xfrmi_dev_setup(struct net_device *dev)
608 {
609 	dev->netdev_ops 	= &xfrmi_netdev_ops;
610 	dev->type		= ARPHRD_NONE;
611 	dev->hard_header_len 	= ETH_HLEN;
612 	dev->min_header_len	= ETH_HLEN;
613 	dev->mtu		= ETH_DATA_LEN;
614 	dev->min_mtu		= ETH_MIN_MTU;
615 	dev->max_mtu		= ETH_DATA_LEN;
616 	dev->addr_len		= ETH_ALEN;
617 	dev->flags 		= IFF_NOARP;
618 	dev->needs_free_netdev	= true;
619 	dev->priv_destructor	= xfrmi_dev_free;
620 	netif_keep_dst(dev);
621 }
622 
xfrmi_dev_init(struct net_device * dev)623 static int xfrmi_dev_init(struct net_device *dev)
624 {
625 	struct xfrm_if *xi = netdev_priv(dev);
626 	struct net_device *phydev = xi->phydev;
627 	int err;
628 
629 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
630 	if (!dev->tstats)
631 		return -ENOMEM;
632 
633 	err = gro_cells_init(&xi->gro_cells, dev);
634 	if (err) {
635 		free_percpu(dev->tstats);
636 		return err;
637 	}
638 
639 	dev->features |= NETIF_F_LLTX;
640 
641 	dev->needed_headroom = phydev->needed_headroom;
642 	dev->needed_tailroom = phydev->needed_tailroom;
643 
644 	if (is_zero_ether_addr(dev->dev_addr))
645 		eth_hw_addr_inherit(dev, phydev);
646 	if (is_zero_ether_addr(dev->broadcast))
647 		memcpy(dev->broadcast, phydev->broadcast, dev->addr_len);
648 
649 	return 0;
650 }
651 
xfrmi_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)652 static int xfrmi_validate(struct nlattr *tb[], struct nlattr *data[],
653 			 struct netlink_ext_ack *extack)
654 {
655 	return 0;
656 }
657 
xfrmi_netlink_parms(struct nlattr * data[],struct xfrm_if_parms * parms)658 static void xfrmi_netlink_parms(struct nlattr *data[],
659 			       struct xfrm_if_parms *parms)
660 {
661 	memset(parms, 0, sizeof(*parms));
662 
663 	if (!data)
664 		return;
665 
666 	if (data[IFLA_XFRM_LINK])
667 		parms->link = nla_get_u32(data[IFLA_XFRM_LINK]);
668 
669 	if (data[IFLA_XFRM_IF_ID])
670 		parms->if_id = nla_get_u32(data[IFLA_XFRM_IF_ID]);
671 }
672 
xfrmi_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)673 static int xfrmi_newlink(struct net *src_net, struct net_device *dev,
674 			struct nlattr *tb[], struct nlattr *data[],
675 			struct netlink_ext_ack *extack)
676 {
677 	struct net *net = dev_net(dev);
678 	struct xfrm_if_parms *p;
679 	struct xfrm_if *xi;
680 
681 	xi = netdev_priv(dev);
682 	p = &xi->p;
683 
684 	xfrmi_netlink_parms(data, p);
685 
686 	if (!tb[IFLA_IFNAME])
687 		return -EINVAL;
688 
689 	nla_strlcpy(p->name, tb[IFLA_IFNAME], IFNAMSIZ);
690 
691 	xi = xfrmi_locate(net, p, 1);
692 	return PTR_ERR_OR_ZERO(xi);
693 }
694 
xfrmi_dellink(struct net_device * dev,struct list_head * head)695 static void xfrmi_dellink(struct net_device *dev, struct list_head *head)
696 {
697 	unregister_netdevice_queue(dev, head);
698 }
699 
xfrmi_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)700 static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[],
701 			   struct nlattr *data[],
702 			   struct netlink_ext_ack *extack)
703 {
704 	struct xfrm_if *xi = netdev_priv(dev);
705 	struct net *net = dev_net(dev);
706 
707 	xfrmi_netlink_parms(data, &xi->p);
708 
709 	xi = xfrmi_locate(net, &xi->p, 0);
710 
711 	if (IS_ERR_OR_NULL(xi)) {
712 		xi = netdev_priv(dev);
713 	} else {
714 		if (xi->dev != dev)
715 			return -EEXIST;
716 	}
717 
718 	return xfrmi_update(xi, &xi->p);
719 }
720 
xfrmi_get_size(const struct net_device * dev)721 static size_t xfrmi_get_size(const struct net_device *dev)
722 {
723 	return
724 		/* IFLA_XFRM_LINK */
725 		nla_total_size(4) +
726 		/* IFLA_XFRM_IF_ID */
727 		nla_total_size(4) +
728 		0;
729 }
730 
xfrmi_fill_info(struct sk_buff * skb,const struct net_device * dev)731 static int xfrmi_fill_info(struct sk_buff *skb, const struct net_device *dev)
732 {
733 	struct xfrm_if *xi = netdev_priv(dev);
734 	struct xfrm_if_parms *parm = &xi->p;
735 
736 	if (nla_put_u32(skb, IFLA_XFRM_LINK, parm->link) ||
737 	    nla_put_u32(skb, IFLA_XFRM_IF_ID, parm->if_id))
738 		goto nla_put_failure;
739 	return 0;
740 
741 nla_put_failure:
742 	return -EMSGSIZE;
743 }
744 
xfrmi_get_link_net(const struct net_device * dev)745 struct net *xfrmi_get_link_net(const struct net_device *dev)
746 {
747 	struct xfrm_if *xi = netdev_priv(dev);
748 
749 	return dev_net(xi->phydev);
750 }
751 
752 static const struct nla_policy xfrmi_policy[IFLA_XFRM_MAX + 1] = {
753 	[IFLA_XFRM_LINK]	= { .type = NLA_U32 },
754 	[IFLA_XFRM_IF_ID]	= { .type = NLA_U32 },
755 };
756 
757 static struct rtnl_link_ops xfrmi_link_ops __read_mostly = {
758 	.kind		= "xfrm",
759 	.maxtype	= IFLA_XFRM_MAX,
760 	.policy		= xfrmi_policy,
761 	.priv_size	= sizeof(struct xfrm_if),
762 	.setup		= xfrmi_dev_setup,
763 	.validate	= xfrmi_validate,
764 	.newlink	= xfrmi_newlink,
765 	.dellink	= xfrmi_dellink,
766 	.changelink	= xfrmi_changelink,
767 	.get_size	= xfrmi_get_size,
768 	.fill_info	= xfrmi_fill_info,
769 	.get_link_net	= xfrmi_get_link_net,
770 };
771 
xfrmi_destroy_interfaces(struct xfrmi_net * xfrmn)772 static void __net_exit xfrmi_destroy_interfaces(struct xfrmi_net *xfrmn)
773 {
774 	struct xfrm_if *xi;
775 	LIST_HEAD(list);
776 
777 	xi = rtnl_dereference(xfrmn->xfrmi[0]);
778 	if (!xi)
779 		return;
780 
781 	unregister_netdevice_queue(xi->dev, &list);
782 	unregister_netdevice_many(&list);
783 }
784 
xfrmi_init_net(struct net * net)785 static int __net_init xfrmi_init_net(struct net *net)
786 {
787 	return 0;
788 }
789 
xfrmi_exit_net(struct net * net)790 static void __net_exit xfrmi_exit_net(struct net *net)
791 {
792 	struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
793 
794 	rtnl_lock();
795 	xfrmi_destroy_interfaces(xfrmn);
796 	rtnl_unlock();
797 }
798 
799 static struct pernet_operations xfrmi_net_ops = {
800 	.init = xfrmi_init_net,
801 	.exit = xfrmi_exit_net,
802 	.id   = &xfrmi_net_id,
803 	.size = sizeof(struct xfrmi_net),
804 };
805 
806 static struct xfrm6_protocol xfrmi_esp6_protocol __read_mostly = {
807 	.handler	=	xfrm6_rcv,
808 	.cb_handler	=	xfrmi_rcv_cb,
809 	.err_handler	=	xfrmi6_err,
810 	.priority	=	10,
811 };
812 
813 static struct xfrm6_protocol xfrmi_ah6_protocol __read_mostly = {
814 	.handler	=	xfrm6_rcv,
815 	.cb_handler	=	xfrmi_rcv_cb,
816 	.err_handler	=	xfrmi6_err,
817 	.priority	=	10,
818 };
819 
820 static struct xfrm6_protocol xfrmi_ipcomp6_protocol __read_mostly = {
821 	.handler	=	xfrm6_rcv,
822 	.cb_handler	=	xfrmi_rcv_cb,
823 	.err_handler	=	xfrmi6_err,
824 	.priority	=	10,
825 };
826 
827 static struct xfrm4_protocol xfrmi_esp4_protocol __read_mostly = {
828 	.handler	=	xfrm4_rcv,
829 	.input_handler	=	xfrm_input,
830 	.cb_handler	=	xfrmi_rcv_cb,
831 	.err_handler	=	xfrmi4_err,
832 	.priority	=	10,
833 };
834 
835 static struct xfrm4_protocol xfrmi_ah4_protocol __read_mostly = {
836 	.handler	=	xfrm4_rcv,
837 	.input_handler	=	xfrm_input,
838 	.cb_handler	=	xfrmi_rcv_cb,
839 	.err_handler	=	xfrmi4_err,
840 	.priority	=	10,
841 };
842 
843 static struct xfrm4_protocol xfrmi_ipcomp4_protocol __read_mostly = {
844 	.handler	=	xfrm4_rcv,
845 	.input_handler	=	xfrm_input,
846 	.cb_handler	=	xfrmi_rcv_cb,
847 	.err_handler	=	xfrmi4_err,
848 	.priority	=	10,
849 };
850 
xfrmi4_init(void)851 static int __init xfrmi4_init(void)
852 {
853 	int err;
854 
855 	err = xfrm4_protocol_register(&xfrmi_esp4_protocol, IPPROTO_ESP);
856 	if (err < 0)
857 		goto xfrm_proto_esp_failed;
858 	err = xfrm4_protocol_register(&xfrmi_ah4_protocol, IPPROTO_AH);
859 	if (err < 0)
860 		goto xfrm_proto_ah_failed;
861 	err = xfrm4_protocol_register(&xfrmi_ipcomp4_protocol, IPPROTO_COMP);
862 	if (err < 0)
863 		goto xfrm_proto_comp_failed;
864 
865 	return 0;
866 
867 xfrm_proto_comp_failed:
868 	xfrm4_protocol_deregister(&xfrmi_ah4_protocol, IPPROTO_AH);
869 xfrm_proto_ah_failed:
870 	xfrm4_protocol_deregister(&xfrmi_esp4_protocol, IPPROTO_ESP);
871 xfrm_proto_esp_failed:
872 	return err;
873 }
874 
xfrmi4_fini(void)875 static void xfrmi4_fini(void)
876 {
877 	xfrm4_protocol_deregister(&xfrmi_ipcomp4_protocol, IPPROTO_COMP);
878 	xfrm4_protocol_deregister(&xfrmi_ah4_protocol, IPPROTO_AH);
879 	xfrm4_protocol_deregister(&xfrmi_esp4_protocol, IPPROTO_ESP);
880 }
881 
xfrmi6_init(void)882 static int __init xfrmi6_init(void)
883 {
884 	int err;
885 
886 	err = xfrm6_protocol_register(&xfrmi_esp6_protocol, IPPROTO_ESP);
887 	if (err < 0)
888 		goto xfrm_proto_esp_failed;
889 	err = xfrm6_protocol_register(&xfrmi_ah6_protocol, IPPROTO_AH);
890 	if (err < 0)
891 		goto xfrm_proto_ah_failed;
892 	err = xfrm6_protocol_register(&xfrmi_ipcomp6_protocol, IPPROTO_COMP);
893 	if (err < 0)
894 		goto xfrm_proto_comp_failed;
895 
896 	return 0;
897 
898 xfrm_proto_comp_failed:
899 	xfrm6_protocol_deregister(&xfrmi_ah6_protocol, IPPROTO_AH);
900 xfrm_proto_ah_failed:
901 	xfrm6_protocol_deregister(&xfrmi_esp6_protocol, IPPROTO_ESP);
902 xfrm_proto_esp_failed:
903 	return err;
904 }
905 
xfrmi6_fini(void)906 static void xfrmi6_fini(void)
907 {
908 	xfrm6_protocol_deregister(&xfrmi_ipcomp6_protocol, IPPROTO_COMP);
909 	xfrm6_protocol_deregister(&xfrmi_ah6_protocol, IPPROTO_AH);
910 	xfrm6_protocol_deregister(&xfrmi_esp6_protocol, IPPROTO_ESP);
911 }
912 
913 static const struct xfrm_if_cb xfrm_if_cb = {
914 	.decode_session =	xfrmi_decode_session,
915 };
916 
xfrmi_init(void)917 static int __init xfrmi_init(void)
918 {
919 	const char *msg;
920 	int err;
921 
922 	pr_info("IPsec XFRM device driver\n");
923 
924 	msg = "tunnel device";
925 	err = register_pernet_device(&xfrmi_net_ops);
926 	if (err < 0)
927 		goto pernet_dev_failed;
928 
929 	msg = "xfrm4 protocols";
930 	err = xfrmi4_init();
931 	if (err < 0)
932 		goto xfrmi4_failed;
933 
934 	msg = "xfrm6 protocols";
935 	err = xfrmi6_init();
936 	if (err < 0)
937 		goto xfrmi6_failed;
938 
939 
940 	msg = "netlink interface";
941 	err = rtnl_link_register(&xfrmi_link_ops);
942 	if (err < 0)
943 		goto rtnl_link_failed;
944 
945 	xfrm_if_register_cb(&xfrm_if_cb);
946 
947 	return err;
948 
949 rtnl_link_failed:
950 	xfrmi6_fini();
951 xfrmi6_failed:
952 	xfrmi4_fini();
953 xfrmi4_failed:
954 	unregister_pernet_device(&xfrmi_net_ops);
955 pernet_dev_failed:
956 	pr_err("xfrmi init: failed to register %s\n", msg);
957 	return err;
958 }
959 
xfrmi_fini(void)960 static void __exit xfrmi_fini(void)
961 {
962 	xfrm_if_unregister_cb();
963 	rtnl_link_unregister(&xfrmi_link_ops);
964 	xfrmi4_fini();
965 	xfrmi6_fini();
966 	unregister_pernet_device(&xfrmi_net_ops);
967 }
968 
969 module_init(xfrmi_init);
970 module_exit(xfrmi_fini);
971 MODULE_LICENSE("GPL");
972 MODULE_ALIAS_RTNL_LINK("xfrm");
973 MODULE_ALIAS_NETDEV("xfrm0");
974 MODULE_AUTHOR("Steffen Klassert");
975 MODULE_DESCRIPTION("XFRM virtual interface");
976