xref: /linux/net/tipc/ib_media.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * net/tipc/ib_media.c: Infiniband bearer support for TIPC
3  *
4  * Copyright (c) 2013 Patrick McHardy <kaber@trash.net>
5  *
6  * Based on eth_media.c, which carries the following copyright notice:
7  *
8  * Copyright (c) 2001-2007, Ericsson AB
9  * Copyright (c) 2005-2008, 2011, Wind River Systems
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions are met:
14  *
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the names of the copyright holders nor the names of its
21  *    contributors may be used to endorse or promote products derived from
22  *    this software without specific prior written permission.
23  *
24  * Alternatively, this software may be distributed under the terms of the
25  * GNU General Public License ("GPL") version 2 as published by the Free
26  * Software Foundation.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
29  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
32  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38  * POSSIBILITY OF SUCH DAMAGE.
39  */
40 
41 #include <linux/if_infiniband.h>
42 #include "core.h"
43 #include "bearer.h"
44 
45 #define MAX_IB_MEDIA		MAX_BEARERS
46 
47 /**
48  * struct ib_media - Infiniband media data structure
49  * @bearer: ptr to associated "generic" bearer structure
50  * @dev: ptr to associated Infiniband network device
51  * @tipc_packet_type: used in binding TIPC to Infiniband driver
52  * @cleanup: work item used when disabling bearer
53  */
54 
55 struct ib_media {
56 	struct tipc_bearer *bearer;
57 	struct net_device *dev;
58 	struct packet_type tipc_packet_type;
59 	struct work_struct setup;
60 	struct work_struct cleanup;
61 };
62 
63 static struct tipc_media ib_media_info;
64 static struct ib_media ib_media_array[MAX_IB_MEDIA];
65 static int ib_started;
66 
67 /**
68  * ib_media_addr_set - initialize Infiniband media address structure
69  *
70  * Media-dependent "value" field stores MAC address in first 6 bytes
71  * and zeroes out the remaining bytes.
72  */
73 static void ib_media_addr_set(const struct tipc_bearer *tb_ptr,
74 			      struct tipc_media_addr *a, char *mac)
75 {
76 	BUILD_BUG_ON(sizeof(a->value) < INFINIBAND_ALEN);
77 	memcpy(a->value, mac, INFINIBAND_ALEN);
78 	a->media_id = TIPC_MEDIA_TYPE_IB;
79 	a->broadcast = !memcmp(mac, tb_ptr->bcast_addr.value, INFINIBAND_ALEN);
80 }
81 
82 /**
83  * send_msg - send a TIPC message out over an InfiniBand interface
84  */
85 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
86 		    struct tipc_media_addr *dest)
87 {
88 	struct sk_buff *clone;
89 	struct net_device *dev;
90 	int delta;
91 
92 	clone = skb_clone(buf, GFP_ATOMIC);
93 	if (!clone)
94 		return 0;
95 
96 	dev = ((struct ib_media *)(tb_ptr->usr_handle))->dev;
97 	delta = dev->hard_header_len - skb_headroom(buf);
98 
99 	if ((delta > 0) &&
100 	    pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
101 		kfree_skb(clone);
102 		return 0;
103 	}
104 
105 	skb_reset_network_header(clone);
106 	clone->dev = dev;
107 	clone->protocol = htons(ETH_P_TIPC);
108 	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
109 			dev->dev_addr, clone->len);
110 	dev_queue_xmit(clone);
111 	return 0;
112 }
113 
114 /**
115  * recv_msg - handle incoming TIPC message from an InfiniBand interface
116  *
117  * Accept only packets explicitly sent to this node, or broadcast packets;
118  * ignores packets sent using InfiniBand multicast, and traffic sent to other
119  * nodes (which can happen if interface is running in promiscuous mode).
120  */
121 static int recv_msg(struct sk_buff *buf, struct net_device *dev,
122 		    struct packet_type *pt, struct net_device *orig_dev)
123 {
124 	struct ib_media *ib_ptr = (struct ib_media *)pt->af_packet_priv;
125 
126 	if (!net_eq(dev_net(dev), &init_net)) {
127 		kfree_skb(buf);
128 		return NET_RX_DROP;
129 	}
130 
131 	if (likely(ib_ptr->bearer)) {
132 		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
133 			buf->next = NULL;
134 			tipc_recv_msg(buf, ib_ptr->bearer);
135 			return NET_RX_SUCCESS;
136 		}
137 	}
138 	kfree_skb(buf);
139 	return NET_RX_DROP;
140 }
141 
142 /**
143  * setup_bearer - setup association between InfiniBand bearer and interface
144  */
145 static void setup_media(struct work_struct *work)
146 {
147 	struct ib_media *ib_ptr =
148 		container_of(work, struct ib_media, setup);
149 
150 	dev_add_pack(&ib_ptr->tipc_packet_type);
151 }
152 
153 /**
154  * enable_media - attach TIPC bearer to an InfiniBand interface
155  */
156 static int enable_media(struct tipc_bearer *tb_ptr)
157 {
158 	struct net_device *dev;
159 	struct ib_media *ib_ptr = &ib_media_array[0];
160 	struct ib_media *stop = &ib_media_array[MAX_IB_MEDIA];
161 	char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
162 	int pending_dev = 0;
163 
164 	/* Find unused InfiniBand bearer structure */
165 	while (ib_ptr->dev) {
166 		if (!ib_ptr->bearer)
167 			pending_dev++;
168 		if (++ib_ptr == stop)
169 			return pending_dev ? -EAGAIN : -EDQUOT;
170 	}
171 
172 	/* Find device with specified name */
173 	dev = dev_get_by_name(&init_net, driver_name);
174 	if (!dev)
175 		return -ENODEV;
176 
177 	/* Create InfiniBand bearer for device */
178 	ib_ptr->dev = dev;
179 	ib_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
180 	ib_ptr->tipc_packet_type.dev = dev;
181 	ib_ptr->tipc_packet_type.func = recv_msg;
182 	ib_ptr->tipc_packet_type.af_packet_priv = ib_ptr;
183 	INIT_LIST_HEAD(&(ib_ptr->tipc_packet_type.list));
184 	INIT_WORK(&ib_ptr->setup, setup_media);
185 	schedule_work(&ib_ptr->setup);
186 
187 	/* Associate TIPC bearer with InfiniBand bearer */
188 	ib_ptr->bearer = tb_ptr;
189 	tb_ptr->usr_handle = (void *)ib_ptr;
190 	memset(tb_ptr->bcast_addr.value, 0, sizeof(tb_ptr->bcast_addr.value));
191 	memcpy(tb_ptr->bcast_addr.value, dev->broadcast, INFINIBAND_ALEN);
192 	tb_ptr->bcast_addr.media_id = TIPC_MEDIA_TYPE_IB;
193 	tb_ptr->bcast_addr.broadcast = 1;
194 	tb_ptr->mtu = dev->mtu;
195 	tb_ptr->blocked = 0;
196 	ib_media_addr_set(tb_ptr, &tb_ptr->addr, (char *)dev->dev_addr);
197 	return 0;
198 }
199 
200 /**
201  * cleanup_bearer - break association between InfiniBand bearer and interface
202  *
203  * This routine must be invoked from a work queue because it can sleep.
204  */
205 static void cleanup_bearer(struct work_struct *work)
206 {
207 	struct ib_media *ib_ptr =
208 		container_of(work, struct ib_media, cleanup);
209 
210 	dev_remove_pack(&ib_ptr->tipc_packet_type);
211 	dev_put(ib_ptr->dev);
212 	ib_ptr->dev = NULL;
213 }
214 
215 /**
216  * disable_media - detach TIPC bearer from an InfiniBand interface
217  *
218  * Mark InfiniBand bearer as inactive so that incoming buffers are thrown away,
219  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
220  * here because cleanup code needs to sleep and caller holds spinlocks.)
221  */
222 static void disable_media(struct tipc_bearer *tb_ptr)
223 {
224 	struct ib_media *ib_ptr = (struct ib_media *)tb_ptr->usr_handle;
225 
226 	ib_ptr->bearer = NULL;
227 	INIT_WORK(&ib_ptr->cleanup, cleanup_bearer);
228 	schedule_work(&ib_ptr->cleanup);
229 }
230 
231 /**
232  * recv_notification - handle device updates from OS
233  *
234  * Change the state of the InfiniBand bearer (if any) associated with the
235  * specified device.
236  */
237 static int recv_notification(struct notifier_block *nb, unsigned long evt,
238 			     void *ptr)
239 {
240 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
241 	struct ib_media *ib_ptr = &ib_media_array[0];
242 	struct ib_media *stop = &ib_media_array[MAX_IB_MEDIA];
243 
244 	if (!net_eq(dev_net(dev), &init_net))
245 		return NOTIFY_DONE;
246 
247 	while ((ib_ptr->dev != dev)) {
248 		if (++ib_ptr == stop)
249 			return NOTIFY_DONE;	/* couldn't find device */
250 	}
251 	if (!ib_ptr->bearer)
252 		return NOTIFY_DONE;		/* bearer had been disabled */
253 
254 	ib_ptr->bearer->mtu = dev->mtu;
255 
256 	switch (evt) {
257 	case NETDEV_CHANGE:
258 		if (netif_carrier_ok(dev))
259 			tipc_continue(ib_ptr->bearer);
260 		else
261 			tipc_block_bearer(ib_ptr->bearer);
262 		break;
263 	case NETDEV_UP:
264 		tipc_continue(ib_ptr->bearer);
265 		break;
266 	case NETDEV_DOWN:
267 		tipc_block_bearer(ib_ptr->bearer);
268 		break;
269 	case NETDEV_CHANGEMTU:
270 	case NETDEV_CHANGEADDR:
271 		tipc_block_bearer(ib_ptr->bearer);
272 		tipc_continue(ib_ptr->bearer);
273 		break;
274 	case NETDEV_UNREGISTER:
275 	case NETDEV_CHANGENAME:
276 		tipc_disable_bearer(ib_ptr->bearer->name);
277 		break;
278 	}
279 	return NOTIFY_OK;
280 }
281 
282 static struct notifier_block notifier = {
283 	.notifier_call	= recv_notification,
284 	.priority	= 0,
285 };
286 
287 /**
288  * ib_addr2str - convert InfiniBand address to string
289  */
290 static int ib_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
291 {
292 	if (str_size < 60)	/* 60 = 19 * strlen("xx:") + strlen("xx\0") */
293 		return 1;
294 
295 	sprintf(str_buf, "%20phC", a->value);
296 
297 	return 0;
298 }
299 
300 /**
301  * ib_addr2msg - convert InfiniBand address format to message header format
302  */
303 static int ib_addr2msg(struct tipc_media_addr *a, char *msg_area)
304 {
305 	memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
306 	msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_IB;
307 	memcpy(msg_area, a->value, INFINIBAND_ALEN);
308 	return 0;
309 }
310 
311 /**
312  * ib_msg2addr - convert message header address format to InfiniBand format
313  */
314 static int ib_msg2addr(const struct tipc_bearer *tb_ptr,
315 		       struct tipc_media_addr *a, char *msg_area)
316 {
317 	ib_media_addr_set(tb_ptr, a, msg_area);
318 	return 0;
319 }
320 
321 /*
322  * InfiniBand media registration info
323  */
324 static struct tipc_media ib_media_info = {
325 	.send_msg	= send_msg,
326 	.enable_media	= enable_media,
327 	.disable_media	= disable_media,
328 	.addr2str	= ib_addr2str,
329 	.addr2msg	= ib_addr2msg,
330 	.msg2addr	= ib_msg2addr,
331 	.priority	= TIPC_DEF_LINK_PRI,
332 	.tolerance	= TIPC_DEF_LINK_TOL,
333 	.window		= TIPC_DEF_LINK_WIN,
334 	.type_id	= TIPC_MEDIA_TYPE_IB,
335 	.name		= "ib"
336 };
337 
338 /**
339  * tipc_ib_media_start - activate InfiniBand bearer support
340  *
341  * Register InfiniBand media type with TIPC bearer code.  Also register
342  * with OS for notifications about device state changes.
343  */
344 int tipc_ib_media_start(void)
345 {
346 	int res;
347 
348 	if (ib_started)
349 		return -EINVAL;
350 
351 	res = tipc_register_media(&ib_media_info);
352 	if (res)
353 		return res;
354 
355 	res = register_netdevice_notifier(&notifier);
356 	if (!res)
357 		ib_started = 1;
358 	return res;
359 }
360 
361 /**
362  * tipc_ib_media_stop - deactivate InfiniBand bearer support
363  */
364 void tipc_ib_media_stop(void)
365 {
366 	if (!ib_started)
367 		return;
368 
369 	flush_scheduled_work();
370 	unregister_netdevice_notifier(&notifier);
371 	ib_started = 0;
372 }
373