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 licensed under one of the following licenses:
8 *
9 * 1) under the terms of the "Common Public License 1.0" a copy of which is
10 *    available from the Open Source Initiative, see
11 *    http://www.opensource.org/licenses/cpl.php.
12 *
13 * 2) under the terms of the "The BSD License" a copy of which is
14 *    available from the Open Source Initiative, see
15 *    http://www.opensource.org/licenses/bsd-license.php.
16 *
17 * 3) under the terms of the "GNU General Public License (GPL) Version 2" a
18 *    copy of which is available from the Open Source Initiative, see
19 *    http://www.opensource.org/licenses/gpl-license.php.
20 *
21 * Licensee has the right to choose one of the above licenses.
22 *
23 * Redistributions of source code must retain the above copyright
24 * notice and one of the license notices.
25 *
26 * Redistributions in binary form must reproduce both the above copyright
27 * notice, one of the license notices in the documentation
28 * and/or other materials provided with the distribution.
29 */
30
31#include <linux/mutex.h>
32#include <linux/inetdevice.h>
33#include <linux/workqueue.h>
34#include <linux/if_arp.h>
35#include <net/arp.h>
36#include <net/neighbour.h>
37#include <net/route.h>
38#include <net/netevent.h>
39#include <rdma/ib_addr.h>
40
41MODULE_AUTHOR("Sean Hefty");
42MODULE_DESCRIPTION("IB Address Translation");
43MODULE_LICENSE("Dual BSD/GPL");
44
45struct addr_req {
46	struct list_head list;
47	struct sockaddr src_addr;
48	struct sockaddr dst_addr;
49	struct rdma_dev_addr *addr;
50	struct rdma_addr_client *client;
51	void *context;
52	void (*callback)(int status, struct sockaddr *src_addr,
53			 struct rdma_dev_addr *addr, void *context);
54	unsigned long timeout;
55	int status;
56};
57
58static void process_req(struct work_struct *work);
59
60static DEFINE_MUTEX(lock);
61static LIST_HEAD(req_list);
62static DECLARE_DELAYED_WORK(work, process_req);
63static struct workqueue_struct *addr_wq;
64
65void rdma_addr_register_client(struct rdma_addr_client *client)
66{
67	atomic_set(&client->refcount, 1);
68	init_completion(&client->comp);
69}
70EXPORT_SYMBOL(rdma_addr_register_client);
71
72static inline void put_client(struct rdma_addr_client *client)
73{
74	if (atomic_dec_and_test(&client->refcount))
75		complete(&client->comp);
76}
77
78void rdma_addr_unregister_client(struct rdma_addr_client *client)
79{
80	put_client(client);
81	wait_for_completion(&client->comp);
82}
83EXPORT_SYMBOL(rdma_addr_unregister_client);
84
85int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
86		     const unsigned char *dst_dev_addr)
87{
88	switch (dev->type) {
89	case ARPHRD_INFINIBAND:
90		dev_addr->dev_type = RDMA_NODE_IB_CA;
91		break;
92	case ARPHRD_ETHER:
93		dev_addr->dev_type = RDMA_NODE_RNIC;
94		break;
95	default:
96		return -EADDRNOTAVAIL;
97	}
98
99	memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
100	memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
101	if (dst_dev_addr)
102		memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
103	return 0;
104}
105EXPORT_SYMBOL(rdma_copy_addr);
106
107int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
108{
109	struct net_device *dev;
110	__be32 ip = ((struct sockaddr_in *) addr)->sin_addr.s_addr;
111	int ret;
112
113	dev = ip_dev_find(ip);
114	if (!dev)
115		return -EADDRNOTAVAIL;
116
117	ret = rdma_copy_addr(dev_addr, dev, NULL);
118	dev_put(dev);
119	return ret;
120}
121EXPORT_SYMBOL(rdma_translate_ip);
122
123static void set_timeout(unsigned long time)
124{
125	unsigned long delay;
126
127	cancel_delayed_work(&work);
128
129	delay = time - jiffies;
130	if ((long)delay <= 0)
131		delay = 1;
132
133	queue_delayed_work(addr_wq, &work, delay);
134}
135
136static void queue_req(struct addr_req *req)
137{
138	struct addr_req *temp_req;
139
140	mutex_lock(&lock);
141	list_for_each_entry_reverse(temp_req, &req_list, list) {
142		if (time_after_eq(req->timeout, temp_req->timeout))
143			break;
144	}
145
146	list_add(&req->list, &temp_req->list);
147
148	if (req_list.next == &req->list)
149		set_timeout(req->timeout);
150	mutex_unlock(&lock);
151}
152
153static void addr_send_arp(struct sockaddr_in *dst_in)
154{
155	struct rtable *rt;
156	struct flowi fl;
157	u32 dst_ip = dst_in->sin_addr.s_addr;
158
159	memset(&fl, 0, sizeof fl);
160	fl.nl_u.ip4_u.daddr = dst_ip;
161	if (ip_route_output_key(&rt, &fl))
162		return;
163
164	arp_send(ARPOP_REQUEST, ETH_P_ARP, rt->rt_gateway, rt->idev->dev,
165		 rt->rt_src, NULL, rt->idev->dev->dev_addr, NULL);
166	ip_rt_put(rt);
167}
168
169static int addr_resolve_remote(struct sockaddr_in *src_in,
170			       struct sockaddr_in *dst_in,
171			       struct rdma_dev_addr *addr)
172{
173	u32 src_ip = src_in->sin_addr.s_addr;
174	u32 dst_ip = dst_in->sin_addr.s_addr;
175	struct flowi fl;
176	struct rtable *rt;
177	struct neighbour *neigh;
178	int ret;
179
180	memset(&fl, 0, sizeof fl);
181	fl.nl_u.ip4_u.daddr = dst_ip;
182	fl.nl_u.ip4_u.saddr = src_ip;
183	ret = ip_route_output_key(&rt, &fl);
184	if (ret)
185		goto out;
186
187	/* If the device does ARP internally, return 'done' */
188	if (rt->idev->dev->flags & IFF_NOARP) {
189		rdma_copy_addr(addr, rt->idev->dev, NULL);
190		goto put;
191	}
192
193	neigh = neigh_lookup(&arp_tbl, &rt->rt_gateway, rt->idev->dev);
194	if (!neigh) {
195		ret = -ENODATA;
196		goto put;
197	}
198
199	if (!(neigh->nud_state & NUD_VALID)) {
200		ret = -ENODATA;
201		goto release;
202	}
203
204	if (!src_ip) {
205		src_in->sin_family = dst_in->sin_family;
206		src_in->sin_addr.s_addr = rt->rt_src;
207	}
208
209	ret = rdma_copy_addr(addr, neigh->dev, neigh->ha);
210release:
211	neigh_release(neigh);
212put:
213	ip_rt_put(rt);
214out:
215	return ret;
216}
217
218static void process_req(struct work_struct *work)
219{
220	struct addr_req *req, *temp_req;
221	struct sockaddr_in *src_in, *dst_in;
222	struct list_head done_list;
223
224	INIT_LIST_HEAD(&done_list);
225
226	mutex_lock(&lock);
227	list_for_each_entry_safe(req, temp_req, &req_list, list) {
228		if (req->status == -ENODATA) {
229			src_in = (struct sockaddr_in *) &req->src_addr;
230			dst_in = (struct sockaddr_in *) &req->dst_addr;
231			req->status = addr_resolve_remote(src_in, dst_in,
232							  req->addr);
233			if (req->status && time_after_eq(jiffies, req->timeout))
234				req->status = -ETIMEDOUT;
235			else if (req->status == -ENODATA)
236				continue;
237		}
238		list_move_tail(&req->list, &done_list);
239	}
240
241	if (!list_empty(&req_list)) {
242		req = list_entry(req_list.next, struct addr_req, list);
243		set_timeout(req->timeout);
244	}
245	mutex_unlock(&lock);
246
247	list_for_each_entry_safe(req, temp_req, &done_list, list) {
248		list_del(&req->list);
249		req->callback(req->status, &req->src_addr, req->addr,
250			      req->context);
251		put_client(req->client);
252		kfree(req);
253	}
254}
255
256static int addr_resolve_local(struct sockaddr_in *src_in,
257			      struct sockaddr_in *dst_in,
258			      struct rdma_dev_addr *addr)
259{
260	struct net_device *dev;
261	u32 src_ip = src_in->sin_addr.s_addr;
262	__be32 dst_ip = dst_in->sin_addr.s_addr;
263	int ret;
264
265	dev = ip_dev_find(dst_ip);
266	if (!dev)
267		return -EADDRNOTAVAIL;
268
269	if (ZERONET(src_ip)) {
270		src_in->sin_family = dst_in->sin_family;
271		src_in->sin_addr.s_addr = dst_ip;
272		ret = rdma_copy_addr(addr, dev, dev->dev_addr);
273	} else if (LOOPBACK(src_ip)) {
274		ret = rdma_translate_ip((struct sockaddr *)dst_in, addr);
275		if (!ret)
276			memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
277	} else {
278		ret = rdma_translate_ip((struct sockaddr *)src_in, addr);
279		if (!ret)
280			memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
281	}
282
283	dev_put(dev);
284	return ret;
285}
286
287int rdma_resolve_ip(struct rdma_addr_client *client,
288		    struct sockaddr *src_addr, struct sockaddr *dst_addr,
289		    struct rdma_dev_addr *addr, int timeout_ms,
290		    void (*callback)(int status, struct sockaddr *src_addr,
291				     struct rdma_dev_addr *addr, void *context),
292		    void *context)
293{
294	struct sockaddr_in *src_in, *dst_in;
295	struct addr_req *req;
296	int ret = 0;
297
298	req = kmalloc(sizeof *req, GFP_KERNEL);
299	if (!req)
300		return -ENOMEM;
301	memset(req, 0, sizeof *req);
302
303	if (src_addr)
304		memcpy(&req->src_addr, src_addr, ip_addr_size(src_addr));
305	memcpy(&req->dst_addr, dst_addr, ip_addr_size(dst_addr));
306	req->addr = addr;
307	req->callback = callback;
308	req->context = context;
309	req->client = client;
310	atomic_inc(&client->refcount);
311
312	src_in = (struct sockaddr_in *) &req->src_addr;
313	dst_in = (struct sockaddr_in *) &req->dst_addr;
314
315	req->status = addr_resolve_local(src_in, dst_in, addr);
316	if (req->status == -EADDRNOTAVAIL)
317		req->status = addr_resolve_remote(src_in, dst_in, addr);
318
319	switch (req->status) {
320	case 0:
321		req->timeout = jiffies;
322		queue_req(req);
323		break;
324	case -ENODATA:
325		req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
326		queue_req(req);
327		addr_send_arp(dst_in);
328		break;
329	default:
330		ret = req->status;
331		atomic_dec(&client->refcount);
332		kfree(req);
333		break;
334	}
335	return ret;
336}
337EXPORT_SYMBOL(rdma_resolve_ip);
338
339void rdma_addr_cancel(struct rdma_dev_addr *addr)
340{
341	struct addr_req *req, *temp_req;
342
343	mutex_lock(&lock);
344	list_for_each_entry_safe(req, temp_req, &req_list, list) {
345		if (req->addr == addr) {
346			req->status = -ECANCELED;
347			req->timeout = jiffies;
348			list_move(&req->list, &req_list);
349			set_timeout(req->timeout);
350			break;
351		}
352	}
353	mutex_unlock(&lock);
354}
355EXPORT_SYMBOL(rdma_addr_cancel);
356
357static int netevent_callback(struct notifier_block *self, unsigned long event,
358	void *ctx)
359{
360	if (event == NETEVENT_NEIGH_UPDATE) {
361		struct neighbour *neigh = ctx;
362
363		if (neigh->nud_state & NUD_VALID) {
364			set_timeout(jiffies);
365		}
366	}
367	return 0;
368}
369
370static struct notifier_block nb = {
371	.notifier_call = netevent_callback
372};
373
374static int addr_init(void)
375{
376	addr_wq = create_singlethread_workqueue("ib_addr");
377	if (!addr_wq)
378		return -ENOMEM;
379
380	register_netevent_notifier(&nb);
381	return 0;
382}
383
384static void addr_cleanup(void)
385{
386	unregister_netevent_notifier(&nb);
387	destroy_workqueue(addr_wq);
388}
389
390module_init(addr_init);
391module_exit(addr_cleanup);
392