1/*
2 * Copyright (c) 2005 Voltaire Inc.  All rights reserved.
3 * Copyright (c) 2002-2005, Network Appliance, Inc. All rights reserved.
4 * Copyright (c) 1999-2005, Mellanox Technologies, Inc. All rights reserved.
5 * Copyright (c) 2005 Intel Corporation.  All rights reserved.
6 *
7 * This software is available to you under a choice of one of two
8 * licenses.  You may choose to be licensed under the terms of the GNU
9 * General Public License (GPL) Version 2, available from the file
10 * COPYING in the main directory of this source tree, or the
11 * OpenIB.org BSD license below:
12 *
13 *     Redistribution and use in source and binary forms, with or
14 *     without modification, are permitted provided that the following
15 *     conditions are met:
16 *
17 *      - Redistributions of source code must retain the above
18 *        copyright notice, this list of conditions and the following
19 *        disclaimer.
20 *
21 *      - Redistributions in binary form must reproduce the above
22 *        copyright notice, this list of conditions and the following
23 *        disclaimer in the documentation and/or other materials
24 *        provided with the distribution.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
27 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
28 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
29 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
30 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
31 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
32 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 * SOFTWARE.
34 */
35
36#include <linux/mutex.h>
37#include <linux/inetdevice.h>
38#include <linux/slab.h>
39#include <linux/workqueue.h>
40#include <linux/module.h>
41#include <net/arp.h>
42#include <net/neighbour.h>
43#include <net/route.h>
44#include <net/netevent.h>
45#include <net/addrconf.h>
46#include <net/ip6_route.h>
47#include <rdma/ib_addr.h>
48#include <rdma/ib.h>
49
50MODULE_AUTHOR("Sean Hefty");
51MODULE_DESCRIPTION("IB Address Translation");
52MODULE_LICENSE("Dual BSD/GPL");
53
54struct addr_req {
55	struct list_head list;
56	struct sockaddr_storage src_addr;
57	struct sockaddr_storage dst_addr;
58	struct rdma_dev_addr *addr;
59	struct rdma_addr_client *client;
60	void *context;
61	void (*callback)(int status, struct sockaddr *src_addr,
62			 struct rdma_dev_addr *addr, void *context);
63	unsigned long timeout;
64	int status;
65};
66
67static void process_req(struct work_struct *work);
68
69static DEFINE_MUTEX(lock);
70static LIST_HEAD(req_list);
71static DECLARE_DELAYED_WORK(work, process_req);
72static struct workqueue_struct *addr_wq;
73
74int rdma_addr_size(struct sockaddr *addr)
75{
76	switch (addr->sa_family) {
77	case AF_INET:
78		return sizeof(struct sockaddr_in);
79	case AF_INET6:
80		return sizeof(struct sockaddr_in6);
81	case AF_IB:
82		return sizeof(struct sockaddr_ib);
83	default:
84		return 0;
85	}
86}
87EXPORT_SYMBOL(rdma_addr_size);
88
89static struct rdma_addr_client self;
90
91void rdma_addr_register_client(struct rdma_addr_client *client)
92{
93	atomic_set(&client->refcount, 1);
94	init_completion(&client->comp);
95}
96EXPORT_SYMBOL(rdma_addr_register_client);
97
98static inline void put_client(struct rdma_addr_client *client)
99{
100	if (atomic_dec_and_test(&client->refcount))
101		complete(&client->comp);
102}
103
104void rdma_addr_unregister_client(struct rdma_addr_client *client)
105{
106	put_client(client);
107	wait_for_completion(&client->comp);
108}
109EXPORT_SYMBOL(rdma_addr_unregister_client);
110
111int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
112		     const unsigned char *dst_dev_addr)
113{
114	dev_addr->dev_type = dev->type;
115	memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
116	memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
117	if (dst_dev_addr)
118		memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
119	dev_addr->bound_dev_if = dev->ifindex;
120	return 0;
121}
122EXPORT_SYMBOL(rdma_copy_addr);
123
124int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr,
125		      u16 *vlan_id)
126{
127	struct net_device *dev;
128	int ret = -EADDRNOTAVAIL;
129
130	if (dev_addr->bound_dev_if) {
131		dev = dev_get_by_index(&init_net, dev_addr->bound_dev_if);
132		if (!dev)
133			return -ENODEV;
134		ret = rdma_copy_addr(dev_addr, dev, NULL);
135		dev_put(dev);
136		return ret;
137	}
138
139	switch (addr->sa_family) {
140	case AF_INET:
141		dev = ip_dev_find(&init_net,
142			((struct sockaddr_in *) addr)->sin_addr.s_addr);
143
144		if (!dev)
145			return ret;
146
147		ret = rdma_copy_addr(dev_addr, dev, NULL);
148		if (vlan_id)
149			*vlan_id = rdma_vlan_dev_vlan_id(dev);
150		dev_put(dev);
151		break;
152
153#if IS_ENABLED(CONFIG_IPV6)
154	case AF_INET6:
155		rcu_read_lock();
156		for_each_netdev_rcu(&init_net, dev) {
157			if (ipv6_chk_addr(&init_net,
158					  &((struct sockaddr_in6 *) addr)->sin6_addr,
159					  dev, 1)) {
160				ret = rdma_copy_addr(dev_addr, dev, NULL);
161				if (vlan_id)
162					*vlan_id = rdma_vlan_dev_vlan_id(dev);
163				break;
164			}
165		}
166		rcu_read_unlock();
167		break;
168#endif
169	}
170	return ret;
171}
172EXPORT_SYMBOL(rdma_translate_ip);
173
174static void set_timeout(unsigned long time)
175{
176	unsigned long delay;
177
178	delay = time - jiffies;
179	if ((long)delay < 0)
180		delay = 0;
181
182	mod_delayed_work(addr_wq, &work, delay);
183}
184
185static void queue_req(struct addr_req *req)
186{
187	struct addr_req *temp_req;
188
189	mutex_lock(&lock);
190	list_for_each_entry_reverse(temp_req, &req_list, list) {
191		if (time_after_eq(req->timeout, temp_req->timeout))
192			break;
193	}
194
195	list_add(&req->list, &temp_req->list);
196
197	if (req_list.next == &req->list)
198		set_timeout(req->timeout);
199	mutex_unlock(&lock);
200}
201
202static int dst_fetch_ha(struct dst_entry *dst, struct rdma_dev_addr *dev_addr, void *daddr)
203{
204	struct neighbour *n;
205	int ret;
206
207	n = dst_neigh_lookup(dst, daddr);
208
209	rcu_read_lock();
210	if (!n || !(n->nud_state & NUD_VALID)) {
211		if (n)
212			neigh_event_send(n, NULL);
213		ret = -ENODATA;
214	} else {
215		ret = rdma_copy_addr(dev_addr, dst->dev, n->ha);
216	}
217	rcu_read_unlock();
218
219	if (n)
220		neigh_release(n);
221
222	return ret;
223}
224
225static int addr4_resolve(struct sockaddr_in *src_in,
226			 struct sockaddr_in *dst_in,
227			 struct rdma_dev_addr *addr)
228{
229	__be32 src_ip = src_in->sin_addr.s_addr;
230	__be32 dst_ip = dst_in->sin_addr.s_addr;
231	struct rtable *rt;
232	struct flowi4 fl4;
233	int ret;
234
235	memset(&fl4, 0, sizeof(fl4));
236	fl4.daddr = dst_ip;
237	fl4.saddr = src_ip;
238	fl4.flowi4_oif = addr->bound_dev_if;
239	rt = ip_route_output_key(&init_net, &fl4);
240	if (IS_ERR(rt)) {
241		ret = PTR_ERR(rt);
242		goto out;
243	}
244	src_in->sin_family = AF_INET;
245	src_in->sin_addr.s_addr = fl4.saddr;
246
247	if (rt->dst.dev->flags & IFF_LOOPBACK) {
248		ret = rdma_translate_ip((struct sockaddr *)dst_in, addr, NULL);
249		if (!ret)
250			memcpy(addr->dst_dev_addr, addr->src_dev_addr, MAX_ADDR_LEN);
251		goto put;
252	}
253
254	/* If the device does ARP internally, return 'done' */
255	if (rt->dst.dev->flags & IFF_NOARP) {
256		ret = rdma_copy_addr(addr, rt->dst.dev, NULL);
257		goto put;
258	}
259
260	ret = dst_fetch_ha(&rt->dst, addr, &fl4.daddr);
261put:
262	ip_rt_put(rt);
263out:
264	return ret;
265}
266
267#if IS_ENABLED(CONFIG_IPV6)
268static int addr6_resolve(struct sockaddr_in6 *src_in,
269			 struct sockaddr_in6 *dst_in,
270			 struct rdma_dev_addr *addr)
271{
272	struct flowi6 fl6;
273	struct dst_entry *dst;
274	int ret;
275
276	memset(&fl6, 0, sizeof fl6);
277	fl6.daddr = dst_in->sin6_addr;
278	fl6.saddr = src_in->sin6_addr;
279	fl6.flowi6_oif = addr->bound_dev_if;
280
281	dst = ip6_route_output(&init_net, NULL, &fl6);
282	if ((ret = dst->error))
283		goto put;
284
285	if (ipv6_addr_any(&fl6.saddr)) {
286		ret = ipv6_dev_get_saddr(&init_net, ip6_dst_idev(dst)->dev,
287					 &fl6.daddr, 0, &fl6.saddr);
288		if (ret)
289			goto put;
290
291		src_in->sin6_family = AF_INET6;
292		src_in->sin6_addr = fl6.saddr;
293	}
294
295	if (dst->dev->flags & IFF_LOOPBACK) {
296		ret = rdma_translate_ip((struct sockaddr *)dst_in, addr, NULL);
297		if (!ret)
298			memcpy(addr->dst_dev_addr, addr->src_dev_addr, MAX_ADDR_LEN);
299		goto put;
300	}
301
302	/* If the device does ARP internally, return 'done' */
303	if (dst->dev->flags & IFF_NOARP) {
304		ret = rdma_copy_addr(addr, dst->dev, NULL);
305		goto put;
306	}
307
308	ret = dst_fetch_ha(dst, addr, &fl6.daddr);
309put:
310	dst_release(dst);
311	return ret;
312}
313#else
314static int addr6_resolve(struct sockaddr_in6 *src_in,
315			 struct sockaddr_in6 *dst_in,
316			 struct rdma_dev_addr *addr)
317{
318	return -EADDRNOTAVAIL;
319}
320#endif
321
322static int addr_resolve(struct sockaddr *src_in,
323			struct sockaddr *dst_in,
324			struct rdma_dev_addr *addr)
325{
326	if (src_in->sa_family == AF_INET) {
327		return addr4_resolve((struct sockaddr_in *) src_in,
328			(struct sockaddr_in *) dst_in, addr);
329	} else
330		return addr6_resolve((struct sockaddr_in6 *) src_in,
331			(struct sockaddr_in6 *) dst_in, addr);
332}
333
334static void process_req(struct work_struct *work)
335{
336	struct addr_req *req, *temp_req;
337	struct sockaddr *src_in, *dst_in;
338	struct list_head done_list;
339
340	INIT_LIST_HEAD(&done_list);
341
342	mutex_lock(&lock);
343	list_for_each_entry_safe(req, temp_req, &req_list, list) {
344		if (req->status == -ENODATA) {
345			src_in = (struct sockaddr *) &req->src_addr;
346			dst_in = (struct sockaddr *) &req->dst_addr;
347			req->status = addr_resolve(src_in, dst_in, req->addr);
348			if (req->status && time_after_eq(jiffies, req->timeout))
349				req->status = -ETIMEDOUT;
350			else if (req->status == -ENODATA)
351				continue;
352		}
353		list_move_tail(&req->list, &done_list);
354	}
355
356	if (!list_empty(&req_list)) {
357		req = list_entry(req_list.next, struct addr_req, list);
358		set_timeout(req->timeout);
359	}
360	mutex_unlock(&lock);
361
362	list_for_each_entry_safe(req, temp_req, &done_list, list) {
363		list_del(&req->list);
364		req->callback(req->status, (struct sockaddr *) &req->src_addr,
365			req->addr, req->context);
366		put_client(req->client);
367		kfree(req);
368	}
369}
370
371int rdma_resolve_ip(struct rdma_addr_client *client,
372		    struct sockaddr *src_addr, struct sockaddr *dst_addr,
373		    struct rdma_dev_addr *addr, int timeout_ms,
374		    void (*callback)(int status, struct sockaddr *src_addr,
375				     struct rdma_dev_addr *addr, void *context),
376		    void *context)
377{
378	struct sockaddr *src_in, *dst_in;
379	struct addr_req *req;
380	int ret = 0;
381
382	req = kzalloc(sizeof *req, GFP_KERNEL);
383	if (!req)
384		return -ENOMEM;
385
386	src_in = (struct sockaddr *) &req->src_addr;
387	dst_in = (struct sockaddr *) &req->dst_addr;
388
389	if (src_addr) {
390		if (src_addr->sa_family != dst_addr->sa_family) {
391			ret = -EINVAL;
392			goto err;
393		}
394
395		memcpy(src_in, src_addr, rdma_addr_size(src_addr));
396	} else {
397		src_in->sa_family = dst_addr->sa_family;
398	}
399
400	memcpy(dst_in, dst_addr, rdma_addr_size(dst_addr));
401	req->addr = addr;
402	req->callback = callback;
403	req->context = context;
404	req->client = client;
405	atomic_inc(&client->refcount);
406
407	req->status = addr_resolve(src_in, dst_in, addr);
408	switch (req->status) {
409	case 0:
410		req->timeout = jiffies;
411		queue_req(req);
412		break;
413	case -ENODATA:
414		req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
415		queue_req(req);
416		break;
417	default:
418		ret = req->status;
419		atomic_dec(&client->refcount);
420		goto err;
421	}
422	return ret;
423err:
424	kfree(req);
425	return ret;
426}
427EXPORT_SYMBOL(rdma_resolve_ip);
428
429void rdma_addr_cancel(struct rdma_dev_addr *addr)
430{
431	struct addr_req *req, *temp_req;
432
433	mutex_lock(&lock);
434	list_for_each_entry_safe(req, temp_req, &req_list, list) {
435		if (req->addr == addr) {
436			req->status = -ECANCELED;
437			req->timeout = jiffies;
438			list_move(&req->list, &req_list);
439			set_timeout(req->timeout);
440			break;
441		}
442	}
443	mutex_unlock(&lock);
444}
445EXPORT_SYMBOL(rdma_addr_cancel);
446
447struct resolve_cb_context {
448	struct rdma_dev_addr *addr;
449	struct completion comp;
450};
451
452static void resolve_cb(int status, struct sockaddr *src_addr,
453	     struct rdma_dev_addr *addr, void *context)
454{
455	memcpy(((struct resolve_cb_context *)context)->addr, addr, sizeof(struct
456				rdma_dev_addr));
457	complete(&((struct resolve_cb_context *)context)->comp);
458}
459
460int rdma_addr_find_dmac_by_grh(union ib_gid *sgid, union ib_gid *dgid, u8 *dmac,
461			       u16 *vlan_id)
462{
463	int ret = 0;
464	struct rdma_dev_addr dev_addr;
465	struct resolve_cb_context ctx;
466	struct net_device *dev;
467
468	union {
469		struct sockaddr     _sockaddr;
470		struct sockaddr_in  _sockaddr_in;
471		struct sockaddr_in6 _sockaddr_in6;
472	} sgid_addr, dgid_addr;
473
474
475	rdma_gid2ip(&sgid_addr._sockaddr, sgid);
476	rdma_gid2ip(&dgid_addr._sockaddr, dgid);
477
478	memset(&dev_addr, 0, sizeof(dev_addr));
479
480	ctx.addr = &dev_addr;
481	init_completion(&ctx.comp);
482	ret = rdma_resolve_ip(&self, &sgid_addr._sockaddr, &dgid_addr._sockaddr,
483			&dev_addr, 1000, resolve_cb, &ctx);
484	if (ret)
485		return ret;
486
487	wait_for_completion(&ctx.comp);
488
489	memcpy(dmac, dev_addr.dst_dev_addr, ETH_ALEN);
490	dev = dev_get_by_index(&init_net, dev_addr.bound_dev_if);
491	if (!dev)
492		return -ENODEV;
493	if (vlan_id)
494		*vlan_id = rdma_vlan_dev_vlan_id(dev);
495	dev_put(dev);
496	return ret;
497}
498EXPORT_SYMBOL(rdma_addr_find_dmac_by_grh);
499
500int rdma_addr_find_smac_by_sgid(union ib_gid *sgid, u8 *smac, u16 *vlan_id)
501{
502	int ret = 0;
503	struct rdma_dev_addr dev_addr;
504	union {
505		struct sockaddr     _sockaddr;
506		struct sockaddr_in  _sockaddr_in;
507		struct sockaddr_in6 _sockaddr_in6;
508	} gid_addr;
509
510	rdma_gid2ip(&gid_addr._sockaddr, sgid);
511
512	memset(&dev_addr, 0, sizeof(dev_addr));
513	ret = rdma_translate_ip(&gid_addr._sockaddr, &dev_addr, vlan_id);
514	if (ret)
515		return ret;
516
517	memcpy(smac, dev_addr.src_dev_addr, ETH_ALEN);
518	return ret;
519}
520EXPORT_SYMBOL(rdma_addr_find_smac_by_sgid);
521
522static int netevent_callback(struct notifier_block *self, unsigned long event,
523	void *ctx)
524{
525	if (event == NETEVENT_NEIGH_UPDATE) {
526		struct neighbour *neigh = ctx;
527
528		if (neigh->nud_state & NUD_VALID) {
529			set_timeout(jiffies);
530		}
531	}
532	return 0;
533}
534
535static struct notifier_block nb = {
536	.notifier_call = netevent_callback
537};
538
539static int __init addr_init(void)
540{
541	addr_wq = create_singlethread_workqueue("ib_addr");
542	if (!addr_wq)
543		return -ENOMEM;
544
545	register_netevent_notifier(&nb);
546	rdma_addr_register_client(&self);
547	return 0;
548}
549
550static void __exit addr_cleanup(void)
551{
552	rdma_addr_unregister_client(&self);
553	unregister_netevent_notifier(&nb);
554	destroy_workqueue(addr_wq);
555}
556
557module_init(addr_init);
558module_exit(addr_cleanup);
559