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block: remove WARN_ON_ONCE() in exit_io_context()
[linux-2.6.git] / net / caif / chnl_net.c
blob865690948bbc7da373cbb12a3abd6c787cb1b7cb
1 /*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Authors: Sjur Brendeland/sjur.brandeland@stericsson.com
4 * Daniel Martensson / Daniel.Martensson@stericsson.com
5 * License terms: GNU General Public License (GPL) version 2
6 */
7
8 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
9
10 #include <linux/fs.h>
11 #include <linux/hardirq.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/netdevice.h>
15 #include <linux/if_ether.h>
16 #include <linux/moduleparam.h>
17 #include <linux/ip.h>
18 #include <linux/sched.h>
19 #include <linux/sockios.h>
20 #include <linux/caif/if_caif.h>
21 #include <net/rtnetlink.h>
22 #include <net/caif/caif_layer.h>
23 #include <net/caif/cfpkt.h>
24 #include <net/caif/caif_dev.h>
25
26 /* GPRS PDP connection has MTU to 1500 */
27 #define GPRS_PDP_MTU 1500
28 /* 5 sec. connect timeout */
29 #define CONNECT_TIMEOUT (5 * HZ)
30 #define CAIF_NET_DEFAULT_QUEUE_LEN 500
31
32 /*This list is protected by the rtnl lock. */
33 static LIST_HEAD(chnl_net_list);
34
35 MODULE_LICENSE("GPL");
36 MODULE_ALIAS_RTNL_LINK("caif");
37
38 enum caif_states {
39 CAIF_CONNECTED = 1,
40 CAIF_CONNECTING,
41 CAIF_DISCONNECTED,
42 CAIF_SHUTDOWN
43 };
44
45 struct chnl_net {
46 struct cflayer chnl;
47 struct net_device_stats stats;
48 struct caif_connect_request conn_req;
49 struct list_head list_field;
50 struct net_device *netdev;
51 char name[256];
52 wait_queue_head_t netmgmt_wq;
53 /* Flow status to remember and control the transmission. */
54 bool flowenabled;
55 enum caif_states state;
56 };
57
58 static void robust_list_del(struct list_head *delete_node)
59 {
60 struct list_head *list_node;
61 struct list_head *n;
62 ASSERT_RTNL();
63 list_for_each_safe(list_node, n, &chnl_net_list) {
64 if (list_node == delete_node) {
65 list_del(list_node);
66 return;
67 }
68 }
69 WARN_ON(1);
70 }
71
72 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
73 {
74 struct sk_buff *skb;
75 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
76 int pktlen;
77 int err = 0;
78 const u8 *ip_version;
79 u8 buf;
80
81 priv = container_of(layr, struct chnl_net, chnl);
82
83 if (!priv)
84 return -EINVAL;
85
86 skb = (struct sk_buff *) cfpkt_tonative(pkt);
87
88 /* Get length of CAIF packet. */
89 pktlen = skb->len;
90
91 /* Pass some minimum information and
92 * send the packet to the net stack.
93 */
94 skb->dev = priv->netdev;
95
96 /* check the version of IP */
97 ip_version = skb_header_pointer(skb, 0, 1, &buf);
98 if (!ip_version)
99 return -EINVAL;
100 switch (*ip_version >> 4) {
101 case 4:
102 skb->protocol = htons(ETH_P_IP);
103 break;
104 case 6:
105 skb->protocol = htons(ETH_P_IPV6);
106 break;
107 default:
108 return -EINVAL;
109 }
110
111 /* If we change the header in loop mode, the checksum is corrupted. */
112 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
113 skb->ip_summed = CHECKSUM_UNNECESSARY;
114 else
115 skb->ip_summed = CHECKSUM_NONE;
116
117 if (in_interrupt())
118 netif_rx(skb);
119 else
120 netif_rx_ni(skb);
121
122 /* Update statistics. */
123 priv->netdev->stats.rx_packets++;
124 priv->netdev->stats.rx_bytes += pktlen;
125
126 return err;
127 }
128
129 static int delete_device(struct chnl_net *dev)
130 {
131 ASSERT_RTNL();
132 if (dev->netdev)
133 unregister_netdevice(dev->netdev);
134 return 0;
135 }
136
137 static void close_work(struct work_struct *work)
138 {
139 struct chnl_net *dev = NULL;
140 struct list_head *list_node;
141 struct list_head *_tmp;
142
143 rtnl_lock();
144 list_for_each_safe(list_node, _tmp, &chnl_net_list) {
145 dev = list_entry(list_node, struct chnl_net, list_field);
146 if (dev->state == CAIF_SHUTDOWN)
147 dev_close(dev->netdev);
148 }
149 rtnl_unlock();
150 }
151 static DECLARE_WORK(close_worker, close_work);
152
153 static void chnl_hold(struct cflayer *lyr)
154 {
155 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
156 dev_hold(priv->netdev);
157 }
158
159 static void chnl_put(struct cflayer *lyr)
160 {
161 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
162 dev_put(priv->netdev);
163 }
164
165 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
166 int phyid)
167 {
168 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
169 pr_debug("NET flowctrl func called flow: %s\n",
170 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
171 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
172 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
173 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
174 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
175 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
176 "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
177
178
179
180 switch (flow) {
181 case CAIF_CTRLCMD_FLOW_OFF_IND:
182 priv->flowenabled = false;
183 netif_stop_queue(priv->netdev);
184 break;
185 case CAIF_CTRLCMD_DEINIT_RSP:
186 priv->state = CAIF_DISCONNECTED;
187 break;
188 case CAIF_CTRLCMD_INIT_FAIL_RSP:
189 priv->state = CAIF_DISCONNECTED;
190 wake_up_interruptible(&priv->netmgmt_wq);
191 break;
192 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
193 priv->state = CAIF_SHUTDOWN;
194 netif_tx_disable(priv->netdev);
195 schedule_work(&close_worker);
196 break;
197 case CAIF_CTRLCMD_FLOW_ON_IND:
198 priv->flowenabled = true;
199 netif_wake_queue(priv->netdev);
200 break;
201 case CAIF_CTRLCMD_INIT_RSP:
202 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
203 priv->state = CAIF_CONNECTED;
204 priv->flowenabled = true;
205 netif_wake_queue(priv->netdev);
206 wake_up_interruptible(&priv->netmgmt_wq);
207 break;
208 default:
209 break;
210 }
211 }
212
213 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
214 {
215 struct chnl_net *priv;
216 struct cfpkt *pkt = NULL;
217 int len;
218 int result = -1;
219 /* Get our private data. */
220 priv = netdev_priv(dev);
221
222 if (skb->len > priv->netdev->mtu) {
223 pr_warn("Size of skb exceeded MTU\n");
224 return -ENOSPC;
225 }
226
227 if (!priv->flowenabled) {
228 pr_debug("dropping packets flow off\n");
229 return NETDEV_TX_BUSY;
230 }
231
232 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
233 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
234
235 /* Store original SKB length. */
236 len = skb->len;
237
238 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
239
240 /* Send the packet down the stack. */
241 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
242 if (result) {
243 if (result == -EAGAIN)
244 result = NETDEV_TX_BUSY;
245 return result;
246 }
247
248 /* Update statistics. */
249 dev->stats.tx_packets++;
250 dev->stats.tx_bytes += len;
251
252 return NETDEV_TX_OK;
253 }
254
255 static int chnl_net_open(struct net_device *dev)
256 {
257 struct chnl_net *priv = NULL;
258 int result = -1;
259 int llifindex, headroom, tailroom, mtu;
260 struct net_device *lldev;
261 ASSERT_RTNL();
262 priv = netdev_priv(dev);
263 if (!priv) {
264 pr_debug("chnl_net_open: no priv\n");
265 return -ENODEV;
266 }
267
268 if (priv->state != CAIF_CONNECTING) {
269 priv->state = CAIF_CONNECTING;
270 result = caif_connect_client(dev_net(dev), &priv->conn_req,
271 &priv->chnl, &llifindex,
272 &headroom, &tailroom);
273 if (result != 0) {
274 pr_debug("err: "
275 "Unable to register and open device,"
276 " Err:%d\n",
277 result);
278 goto error;
279 }
280
281 lldev = dev_get_by_index(dev_net(dev), llifindex);
282
283 if (lldev == NULL) {
284 pr_debug("no interface?\n");
285 result = -ENODEV;
286 goto error;
287 }
288
289 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
290 dev->hard_header_len = headroom + lldev->hard_header_len +
291 lldev->needed_tailroom;
292
293 /*
294 * MTU, head-room etc is not know before we have a
295 * CAIF link layer device available. MTU calculation may
296 * override initial RTNL configuration.
297 * MTU is minimum of current mtu, link layer mtu pluss
298 * CAIF head and tail, and PDP GPRS contexts max MTU.
299 */
300 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
301 mtu = min_t(int, GPRS_PDP_MTU, mtu);
302 dev_set_mtu(dev, mtu);
303 dev_put(lldev);
304
305 if (mtu < 100) {
306 pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
307 result = -ENODEV;
308 goto error;
309 }
310 }
311
312 rtnl_unlock(); /* Release RTNL lock during connect wait */
313
314 result = wait_event_interruptible_timeout(priv->netmgmt_wq,
315 priv->state != CAIF_CONNECTING,
316 CONNECT_TIMEOUT);
317
318 rtnl_lock();
319
320 if (result == -ERESTARTSYS) {
321 pr_debug("wait_event_interruptible woken by a signal\n");
322 result = -ERESTARTSYS;
323 goto error;
324 }
325
326 if (result == 0) {
327 pr_debug("connect timeout\n");
328 caif_disconnect_client(dev_net(dev), &priv->chnl);
329 priv->state = CAIF_DISCONNECTED;
330 pr_debug("state disconnected\n");
331 result = -ETIMEDOUT;
332 goto error;
333 }
334
335 if (priv->state != CAIF_CONNECTED) {
336 pr_debug("connect failed\n");
337 result = -ECONNREFUSED;
338 goto error;
339 }
340 pr_debug("CAIF Netdevice connected\n");
341 return 0;
342
343 error:
344 caif_disconnect_client(dev_net(dev), &priv->chnl);
345 priv->state = CAIF_DISCONNECTED;
346 pr_debug("state disconnected\n");
347 return result;
348
349 }
350
351 static int chnl_net_stop(struct net_device *dev)
352 {
353 struct chnl_net *priv;
354
355 ASSERT_RTNL();
356 priv = netdev_priv(dev);
357 priv->state = CAIF_DISCONNECTED;
358 caif_disconnect_client(dev_net(dev), &priv->chnl);
359 return 0;
360 }
361
362 static int chnl_net_init(struct net_device *dev)
363 {
364 struct chnl_net *priv;
365 ASSERT_RTNL();
366 priv = netdev_priv(dev);
367 strncpy(priv->name, dev->name, sizeof(priv->name));
368 return 0;
369 }
370
371 static void chnl_net_uninit(struct net_device *dev)
372 {
373 struct chnl_net *priv;
374 ASSERT_RTNL();
375 priv = netdev_priv(dev);
376 robust_list_del(&priv->list_field);
377 }
378
379 static const struct net_device_ops netdev_ops = {
380 .ndo_open = chnl_net_open,
381 .ndo_stop = chnl_net_stop,
382 .ndo_init = chnl_net_init,
383 .ndo_uninit = chnl_net_uninit,
384 .ndo_start_xmit = chnl_net_start_xmit,
385 };
386
387 static void chnl_net_destructor(struct net_device *dev)
388 {
389 struct chnl_net *priv = netdev_priv(dev);
390 caif_free_client(&priv->chnl);
391 free_netdev(dev);
392 }
393
394 static void ipcaif_net_setup(struct net_device *dev)
395 {
396 struct chnl_net *priv;
397 dev->netdev_ops = &netdev_ops;
398 dev->destructor = chnl_net_destructor;
399 dev->flags |= IFF_NOARP;
400 dev->flags |= IFF_POINTOPOINT;
401 dev->mtu = GPRS_PDP_MTU;
402 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
403
404 priv = netdev_priv(dev);
405 priv->chnl.receive = chnl_recv_cb;
406 priv->chnl.ctrlcmd = chnl_flowctrl_cb;
407 priv->netdev = dev;
408 priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
409 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
410 priv->conn_req.priority = CAIF_PRIO_LOW;
411 /* Insert illegal value */
412 priv->conn_req.sockaddr.u.dgm.connection_id = 0;
413 priv->flowenabled = false;
414
415 init_waitqueue_head(&priv->netmgmt_wq);
416 }
417
418
419 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
420 {
421 struct chnl_net *priv;
422 u8 loop;
423 priv = netdev_priv(dev);
424 NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID,
425 priv->conn_req.sockaddr.u.dgm.connection_id);
426 NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID,
427 priv->conn_req.sockaddr.u.dgm.connection_id);
428 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
429 NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop);
430
431
432 return 0;
433 nla_put_failure:
434 return -EMSGSIZE;
435
436 }
437
438 static void caif_netlink_parms(struct nlattr *data[],
439 struct caif_connect_request *conn_req)
440 {
441 if (!data) {
442 pr_warn("no params data found\n");
443 return;
444 }
445 if (data[IFLA_CAIF_IPV4_CONNID])
446 conn_req->sockaddr.u.dgm.connection_id =
447 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
448 if (data[IFLA_CAIF_IPV6_CONNID])
449 conn_req->sockaddr.u.dgm.connection_id =
450 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
451 if (data[IFLA_CAIF_LOOPBACK]) {
452 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
453 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
454 else
455 conn_req->protocol = CAIFPROTO_DATAGRAM;
456 }
457 }
458
459 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
460 struct nlattr *tb[], struct nlattr *data[])
461 {
462 int ret;
463 struct chnl_net *caifdev;
464 ASSERT_RTNL();
465 caifdev = netdev_priv(dev);
466 caif_netlink_parms(data, &caifdev->conn_req);
467 dev_net_set(caifdev->netdev, src_net);
468
469 ret = register_netdevice(dev);
470 if (ret)
471 pr_warn("device rtml registration failed\n");
472 else
473 list_add(&caifdev->list_field, &chnl_net_list);
474
475 /* Take ifindex as connection-id if null */
476 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == 0)
477 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
478 return ret;
479 }
480
481 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
482 struct nlattr *data[])
483 {
484 struct chnl_net *caifdev;
485 ASSERT_RTNL();
486 caifdev = netdev_priv(dev);
487 caif_netlink_parms(data, &caifdev->conn_req);
488 netdev_state_change(dev);
489 return 0;
490 }
491
492 static size_t ipcaif_get_size(const struct net_device *dev)
493 {
494 return
495 /* IFLA_CAIF_IPV4_CONNID */
496 nla_total_size(4) +
497 /* IFLA_CAIF_IPV6_CONNID */
498 nla_total_size(4) +
499 /* IFLA_CAIF_LOOPBACK */
500 nla_total_size(2) +
501 0;
502 }
503
504 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
505 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 },
506 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 },
507 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 }
508 };
509
510
511 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
512 .kind = "caif",
513 .priv_size = sizeof(struct chnl_net),
514 .setup = ipcaif_net_setup,
515 .maxtype = IFLA_CAIF_MAX,
516 .policy = ipcaif_policy,
517 .newlink = ipcaif_newlink,
518 .changelink = ipcaif_changelink,
519 .get_size = ipcaif_get_size,
520 .fill_info = ipcaif_fill_info,
521
522 };
523
524 static int __init chnl_init_module(void)
525 {
526 return rtnl_link_register(&ipcaif_link_ops);
527 }
528
529 static void __exit chnl_exit_module(void)
530 {
531 struct chnl_net *dev = NULL;
532 struct list_head *list_node;
533 struct list_head *_tmp;
534 rtnl_link_unregister(&ipcaif_link_ops);
535 rtnl_lock();
536 list_for_each_safe(list_node, _tmp, &chnl_net_list) {
537 dev = list_entry(list_node, struct chnl_net, list_field);
538 list_del(list_node);
539 delete_device(dev);
540 }
541 rtnl_unlock();
542 }
543
544 module_init(chnl_init_module);
545 module_exit(chnl_exit_module);
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