xref: /linux/drivers/infiniband/core/addr.c (revision 5e8d780d745c1619aba81fe7166c5a4b5cad2b84)
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 <rdma/ib_addr.h>
39 
40 MODULE_AUTHOR("Sean Hefty");
41 MODULE_DESCRIPTION("IB Address Translation");
42 MODULE_LICENSE("Dual BSD/GPL");
43 
44 struct addr_req {
45 	struct list_head list;
46 	struct sockaddr src_addr;
47 	struct sockaddr dst_addr;
48 	struct rdma_dev_addr *addr;
49 	void *context;
50 	void (*callback)(int status, struct sockaddr *src_addr,
51 			 struct rdma_dev_addr *addr, void *context);
52 	unsigned long timeout;
53 	int status;
54 };
55 
56 static void process_req(void *data);
57 
58 static DEFINE_MUTEX(lock);
59 static LIST_HEAD(req_list);
60 static DECLARE_WORK(work, process_req, NULL);
61 static struct workqueue_struct *addr_wq;
62 
63 static int copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
64 		     unsigned char *dst_dev_addr)
65 {
66 	switch (dev->type) {
67 	case ARPHRD_INFINIBAND:
68 		dev_addr->dev_type = IB_NODE_CA;
69 		break;
70 	default:
71 		return -EADDRNOTAVAIL;
72 	}
73 
74 	memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
75 	memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
76 	if (dst_dev_addr)
77 		memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
78 	return 0;
79 }
80 
81 int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
82 {
83 	struct net_device *dev;
84 	u32 ip = ((struct sockaddr_in *) addr)->sin_addr.s_addr;
85 	int ret;
86 
87 	dev = ip_dev_find(ip);
88 	if (!dev)
89 		return -EADDRNOTAVAIL;
90 
91 	ret = copy_addr(dev_addr, dev, NULL);
92 	dev_put(dev);
93 	return ret;
94 }
95 EXPORT_SYMBOL(rdma_translate_ip);
96 
97 static void set_timeout(unsigned long time)
98 {
99 	unsigned long delay;
100 
101 	cancel_delayed_work(&work);
102 
103 	delay = time - jiffies;
104 	if ((long)delay <= 0)
105 		delay = 1;
106 
107 	queue_delayed_work(addr_wq, &work, delay);
108 }
109 
110 static void queue_req(struct addr_req *req)
111 {
112 	struct addr_req *temp_req;
113 
114 	mutex_lock(&lock);
115 	list_for_each_entry_reverse(temp_req, &req_list, list) {
116 		if (time_after(req->timeout, temp_req->timeout))
117 			break;
118 	}
119 
120 	list_add(&req->list, &temp_req->list);
121 
122 	if (req_list.next == &req->list)
123 		set_timeout(req->timeout);
124 	mutex_unlock(&lock);
125 }
126 
127 static void addr_send_arp(struct sockaddr_in *dst_in)
128 {
129 	struct rtable *rt;
130 	struct flowi fl;
131 	u32 dst_ip = dst_in->sin_addr.s_addr;
132 
133 	memset(&fl, 0, sizeof fl);
134 	fl.nl_u.ip4_u.daddr = dst_ip;
135 	if (ip_route_output_key(&rt, &fl))
136 		return;
137 
138 	arp_send(ARPOP_REQUEST, ETH_P_ARP, rt->rt_gateway, rt->idev->dev,
139 		 rt->rt_src, NULL, rt->idev->dev->dev_addr, NULL);
140 	ip_rt_put(rt);
141 }
142 
143 static int addr_resolve_remote(struct sockaddr_in *src_in,
144 			       struct sockaddr_in *dst_in,
145 			       struct rdma_dev_addr *addr)
146 {
147 	u32 src_ip = src_in->sin_addr.s_addr;
148 	u32 dst_ip = dst_in->sin_addr.s_addr;
149 	struct flowi fl;
150 	struct rtable *rt;
151 	struct neighbour *neigh;
152 	int ret;
153 
154 	memset(&fl, 0, sizeof fl);
155 	fl.nl_u.ip4_u.daddr = dst_ip;
156 	fl.nl_u.ip4_u.saddr = src_ip;
157 	ret = ip_route_output_key(&rt, &fl);
158 	if (ret)
159 		goto out;
160 
161 	/* If the device does ARP internally, return 'done' */
162 	if (rt->idev->dev->flags & IFF_NOARP) {
163 		copy_addr(addr, rt->idev->dev, NULL);
164 		goto put;
165 	}
166 
167 	neigh = neigh_lookup(&arp_tbl, &rt->rt_gateway, rt->idev->dev);
168 	if (!neigh) {
169 		ret = -ENODATA;
170 		goto put;
171 	}
172 
173 	if (!(neigh->nud_state & NUD_VALID)) {
174 		ret = -ENODATA;
175 		goto release;
176 	}
177 
178 	if (!src_ip) {
179 		src_in->sin_family = dst_in->sin_family;
180 		src_in->sin_addr.s_addr = rt->rt_src;
181 	}
182 
183 	ret = copy_addr(addr, neigh->dev, neigh->ha);
184 release:
185 	neigh_release(neigh);
186 put:
187 	ip_rt_put(rt);
188 out:
189 	return ret;
190 }
191 
192 static void process_req(void *data)
193 {
194 	struct addr_req *req, *temp_req;
195 	struct sockaddr_in *src_in, *dst_in;
196 	struct list_head done_list;
197 
198 	INIT_LIST_HEAD(&done_list);
199 
200 	mutex_lock(&lock);
201 	list_for_each_entry_safe(req, temp_req, &req_list, list) {
202 		if (req->status) {
203 			src_in = (struct sockaddr_in *) &req->src_addr;
204 			dst_in = (struct sockaddr_in *) &req->dst_addr;
205 			req->status = addr_resolve_remote(src_in, dst_in,
206 							  req->addr);
207 		}
208 		if (req->status && time_after(jiffies, req->timeout))
209 			req->status = -ETIMEDOUT;
210 		else if (req->status == -ENODATA)
211 			continue;
212 
213 		list_del(&req->list);
214 		list_add_tail(&req->list, &done_list);
215 	}
216 
217 	if (!list_empty(&req_list)) {
218 		req = list_entry(req_list.next, struct addr_req, list);
219 		set_timeout(req->timeout);
220 	}
221 	mutex_unlock(&lock);
222 
223 	list_for_each_entry_safe(req, temp_req, &done_list, list) {
224 		list_del(&req->list);
225 		req->callback(req->status, &req->src_addr, req->addr,
226 			      req->context);
227 		kfree(req);
228 	}
229 }
230 
231 static int addr_resolve_local(struct sockaddr_in *src_in,
232 			      struct sockaddr_in *dst_in,
233 			      struct rdma_dev_addr *addr)
234 {
235 	struct net_device *dev;
236 	u32 src_ip = src_in->sin_addr.s_addr;
237 	u32 dst_ip = dst_in->sin_addr.s_addr;
238 	int ret;
239 
240 	dev = ip_dev_find(dst_ip);
241 	if (!dev)
242 		return -EADDRNOTAVAIL;
243 
244 	if (ZERONET(src_ip)) {
245 		src_in->sin_family = dst_in->sin_family;
246 		src_in->sin_addr.s_addr = dst_ip;
247 		ret = copy_addr(addr, dev, dev->dev_addr);
248 	} else if (LOOPBACK(src_ip)) {
249 		ret = rdma_translate_ip((struct sockaddr *)dst_in, addr);
250 		if (!ret)
251 			memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
252 	} else {
253 		ret = rdma_translate_ip((struct sockaddr *)src_in, addr);
254 		if (!ret)
255 			memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
256 	}
257 
258 	dev_put(dev);
259 	return ret;
260 }
261 
262 int rdma_resolve_ip(struct sockaddr *src_addr, struct sockaddr *dst_addr,
263 		    struct rdma_dev_addr *addr, int timeout_ms,
264 		    void (*callback)(int status, struct sockaddr *src_addr,
265 				     struct rdma_dev_addr *addr, void *context),
266 		    void *context)
267 {
268 	struct sockaddr_in *src_in, *dst_in;
269 	struct addr_req *req;
270 	int ret = 0;
271 
272 	req = kmalloc(sizeof *req, GFP_KERNEL);
273 	if (!req)
274 		return -ENOMEM;
275 	memset(req, 0, sizeof *req);
276 
277 	if (src_addr)
278 		memcpy(&req->src_addr, src_addr, ip_addr_size(src_addr));
279 	memcpy(&req->dst_addr, dst_addr, ip_addr_size(dst_addr));
280 	req->addr = addr;
281 	req->callback = callback;
282 	req->context = context;
283 
284 	src_in = (struct sockaddr_in *) &req->src_addr;
285 	dst_in = (struct sockaddr_in *) &req->dst_addr;
286 
287 	req->status = addr_resolve_local(src_in, dst_in, addr);
288 	if (req->status == -EADDRNOTAVAIL)
289 		req->status = addr_resolve_remote(src_in, dst_in, addr);
290 
291 	switch (req->status) {
292 	case 0:
293 		req->timeout = jiffies;
294 		queue_req(req);
295 		break;
296 	case -ENODATA:
297 		req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
298 		queue_req(req);
299 		addr_send_arp(dst_in);
300 		break;
301 	default:
302 		ret = req->status;
303 		kfree(req);
304 		break;
305 	}
306 	return ret;
307 }
308 EXPORT_SYMBOL(rdma_resolve_ip);
309 
310 void rdma_addr_cancel(struct rdma_dev_addr *addr)
311 {
312 	struct addr_req *req, *temp_req;
313 
314 	mutex_lock(&lock);
315 	list_for_each_entry_safe(req, temp_req, &req_list, list) {
316 		if (req->addr == addr) {
317 			req->status = -ECANCELED;
318 			req->timeout = jiffies;
319 			list_del(&req->list);
320 			list_add(&req->list, &req_list);
321 			set_timeout(req->timeout);
322 			break;
323 		}
324 	}
325 	mutex_unlock(&lock);
326 }
327 EXPORT_SYMBOL(rdma_addr_cancel);
328 
329 static int addr_arp_recv(struct sk_buff *skb, struct net_device *dev,
330 			 struct packet_type *pkt, struct net_device *orig_dev)
331 {
332 	struct arphdr *arp_hdr;
333 
334 	arp_hdr = (struct arphdr *) skb->nh.raw;
335 
336 	if (arp_hdr->ar_op == htons(ARPOP_REQUEST) ||
337 	    arp_hdr->ar_op == htons(ARPOP_REPLY))
338 		set_timeout(jiffies);
339 
340 	kfree_skb(skb);
341 	return 0;
342 }
343 
344 static struct packet_type addr_arp = {
345 	.type           = __constant_htons(ETH_P_ARP),
346 	.func           = addr_arp_recv,
347 	.af_packet_priv = (void*) 1,
348 };
349 
350 static int addr_init(void)
351 {
352 	addr_wq = create_singlethread_workqueue("ib_addr_wq");
353 	if (!addr_wq)
354 		return -ENOMEM;
355 
356 	dev_add_pack(&addr_arp);
357 	return 0;
358 }
359 
360 static void addr_cleanup(void)
361 {
362 	dev_remove_pack(&addr_arp);
363 	destroy_workqueue(addr_wq);
364 }
365 
366 module_init(addr_init);
367 module_exit(addr_cleanup);
368