IB/mad: Fix incorrect access to items on local_list
[linux-2.6] / drivers / infiniband / core / addr.c
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
41 MODULE_AUTHOR("Sean Hefty");
42 MODULE_DESCRIPTION("IB Address Translation");
43 MODULE_LICENSE("Dual BSD/GPL");
44
45 struct 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
58 static void process_req(struct work_struct *work);
59
60 static DEFINE_MUTEX(lock);
61 static LIST_HEAD(req_list);
62 static DECLARE_DELAYED_WORK(work, process_req);
63 static struct workqueue_struct *addr_wq;
64
65 void rdma_addr_register_client(struct rdma_addr_client *client)
66 {
67         atomic_set(&client->refcount, 1);
68         init_completion(&client->comp);
69 }
70 EXPORT_SYMBOL(rdma_addr_register_client);
71
72 static inline void put_client(struct rdma_addr_client *client)
73 {
74         if (atomic_dec_and_test(&client->refcount))
75                 complete(&client->comp);
76 }
77
78 void rdma_addr_unregister_client(struct rdma_addr_client *client)
79 {
80         put_client(client);
81         wait_for_completion(&client->comp);
82 }
83 EXPORT_SYMBOL(rdma_addr_unregister_client);
84
85 int 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 }
105 EXPORT_SYMBOL(rdma_copy_addr);
106
107 int 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 }
121 EXPORT_SYMBOL(rdma_translate_ip);
122
123 static 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
136 static 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
153 static 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         neigh_event_send(rt->u.dst.neighbour, NULL);
165         ip_rt_put(rt);
166 }
167
168 static int addr_resolve_remote(struct sockaddr_in *src_in,
169                                struct sockaddr_in *dst_in,
170                                struct rdma_dev_addr *addr)
171 {
172         u32 src_ip = src_in->sin_addr.s_addr;
173         u32 dst_ip = dst_in->sin_addr.s_addr;
174         struct flowi fl;
175         struct rtable *rt;
176         struct neighbour *neigh;
177         int ret;
178
179         memset(&fl, 0, sizeof fl);
180         fl.nl_u.ip4_u.daddr = dst_ip;
181         fl.nl_u.ip4_u.saddr = src_ip;
182         ret = ip_route_output_key(&rt, &fl);
183         if (ret)
184                 goto out;
185
186         /* If the device does ARP internally, return 'done' */
187         if (rt->idev->dev->flags & IFF_NOARP) {
188                 rdma_copy_addr(addr, rt->idev->dev, NULL);
189                 goto put;
190         }
191
192         neigh = neigh_lookup(&arp_tbl, &rt->rt_gateway, rt->idev->dev);
193         if (!neigh) {
194                 ret = -ENODATA;
195                 goto put;
196         }
197
198         if (!(neigh->nud_state & NUD_VALID)) {
199                 ret = -ENODATA;
200                 goto release;
201         }
202
203         if (!src_ip) {
204                 src_in->sin_family = dst_in->sin_family;
205                 src_in->sin_addr.s_addr = rt->rt_src;
206         }
207
208         ret = rdma_copy_addr(addr, neigh->dev, neigh->ha);
209 release:
210         neigh_release(neigh);
211 put:
212         ip_rt_put(rt);
213 out:
214         return ret;
215 }
216
217 static void process_req(struct work_struct *work)
218 {
219         struct addr_req *req, *temp_req;
220         struct sockaddr_in *src_in, *dst_in;
221         struct list_head done_list;
222
223         INIT_LIST_HEAD(&done_list);
224
225         mutex_lock(&lock);
226         list_for_each_entry_safe(req, temp_req, &req_list, list) {
227                 if (req->status == -ENODATA) {
228                         src_in = (struct sockaddr_in *) &req->src_addr;
229                         dst_in = (struct sockaddr_in *) &req->dst_addr;
230                         req->status = addr_resolve_remote(src_in, dst_in,
231                                                           req->addr);
232                         if (req->status && time_after_eq(jiffies, req->timeout))
233                                 req->status = -ETIMEDOUT;
234                         else if (req->status == -ENODATA)
235                                 continue;
236                 }
237                 list_move_tail(&req->list, &done_list);
238         }
239
240         if (!list_empty(&req_list)) {
241                 req = list_entry(req_list.next, struct addr_req, list);
242                 set_timeout(req->timeout);
243         }
244         mutex_unlock(&lock);
245
246         list_for_each_entry_safe(req, temp_req, &done_list, list) {
247                 list_del(&req->list);
248                 req->callback(req->status, &req->src_addr, req->addr,
249                               req->context);
250                 put_client(req->client);
251                 kfree(req);
252         }
253 }
254
255 static int addr_resolve_local(struct sockaddr_in *src_in,
256                               struct sockaddr_in *dst_in,
257                               struct rdma_dev_addr *addr)
258 {
259         struct net_device *dev;
260         u32 src_ip = src_in->sin_addr.s_addr;
261         __be32 dst_ip = dst_in->sin_addr.s_addr;
262         int ret;
263
264         dev = ip_dev_find(dst_ip);
265         if (!dev)
266                 return -EADDRNOTAVAIL;
267
268         if (ZERONET(src_ip)) {
269                 src_in->sin_family = dst_in->sin_family;
270                 src_in->sin_addr.s_addr = dst_ip;
271                 ret = rdma_copy_addr(addr, dev, dev->dev_addr);
272         } else if (LOOPBACK(src_ip)) {
273                 ret = rdma_translate_ip((struct sockaddr *)dst_in, addr);
274                 if (!ret)
275                         memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
276         } else {
277                 ret = rdma_translate_ip((struct sockaddr *)src_in, addr);
278                 if (!ret)
279                         memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
280         }
281
282         dev_put(dev);
283         return ret;
284 }
285
286 int rdma_resolve_ip(struct rdma_addr_client *client,
287                     struct sockaddr *src_addr, struct sockaddr *dst_addr,
288                     struct rdma_dev_addr *addr, int timeout_ms,
289                     void (*callback)(int status, struct sockaddr *src_addr,
290                                      struct rdma_dev_addr *addr, void *context),
291                     void *context)
292 {
293         struct sockaddr_in *src_in, *dst_in;
294         struct addr_req *req;
295         int ret = 0;
296
297         req = kzalloc(sizeof *req, GFP_KERNEL);
298         if (!req)
299                 return -ENOMEM;
300
301         if (src_addr)
302                 memcpy(&req->src_addr, src_addr, ip_addr_size(src_addr));
303         memcpy(&req->dst_addr, dst_addr, ip_addr_size(dst_addr));
304         req->addr = addr;
305         req->callback = callback;
306         req->context = context;
307         req->client = client;
308         atomic_inc(&client->refcount);
309
310         src_in = (struct sockaddr_in *) &req->src_addr;
311         dst_in = (struct sockaddr_in *) &req->dst_addr;
312
313         req->status = addr_resolve_local(src_in, dst_in, addr);
314         if (req->status == -EADDRNOTAVAIL)
315                 req->status = addr_resolve_remote(src_in, dst_in, addr);
316
317         switch (req->status) {
318         case 0:
319                 req->timeout = jiffies;
320                 queue_req(req);
321                 break;
322         case -ENODATA:
323                 req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
324                 queue_req(req);
325                 addr_send_arp(dst_in);
326                 break;
327         default:
328                 ret = req->status;
329                 atomic_dec(&client->refcount);
330                 kfree(req);
331                 break;
332         }
333         return ret;
334 }
335 EXPORT_SYMBOL(rdma_resolve_ip);
336
337 void rdma_addr_cancel(struct rdma_dev_addr *addr)
338 {
339         struct addr_req *req, *temp_req;
340
341         mutex_lock(&lock);
342         list_for_each_entry_safe(req, temp_req, &req_list, list) {
343                 if (req->addr == addr) {
344                         req->status = -ECANCELED;
345                         req->timeout = jiffies;
346                         list_move(&req->list, &req_list);
347                         set_timeout(req->timeout);
348                         break;
349                 }
350         }
351         mutex_unlock(&lock);
352 }
353 EXPORT_SYMBOL(rdma_addr_cancel);
354
355 static int netevent_callback(struct notifier_block *self, unsigned long event,
356         void *ctx)
357 {
358         if (event == NETEVENT_NEIGH_UPDATE) {
359                 struct neighbour *neigh = ctx;
360
361                 if (neigh->nud_state & NUD_VALID) {
362                         set_timeout(jiffies);
363                 }
364         }
365         return 0;
366 }
367
368 static struct notifier_block nb = {
369         .notifier_call = netevent_callback
370 };
371
372 static int addr_init(void)
373 {
374         addr_wq = create_singlethread_workqueue("ib_addr");
375         if (!addr_wq)
376                 return -ENOMEM;
377
378         register_netevent_notifier(&nb);
379         return 0;
380 }
381
382 static void addr_cleanup(void)
383 {
384         unregister_netevent_notifier(&nb);
385         destroy_workqueue(addr_wq);
386 }
387
388 module_init(addr_init);
389 module_exit(addr_cleanup);