ARM: tegra: dvfs: Add interface to set fmax at vmin
[linux-3.10.git] / net / caif / chnl_net.c
1 /*
2  * Copyright (C) ST-Ericsson AB 2010
3  * Authors:     Sjur Brendeland
4  *              Daniel Martensson
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 #define UNDEF_CONNID 0xffffffff
32
33 /*This list is protected by the rtnl lock. */
34 static LIST_HEAD(chnl_net_list);
35
36 MODULE_LICENSE("GPL");
37 MODULE_ALIAS_RTNL_LINK("caif");
38
39 enum caif_states {
40         CAIF_CONNECTED          = 1,
41         CAIF_CONNECTING,
42         CAIF_DISCONNECTED,
43         CAIF_SHUTDOWN
44 };
45
46 struct chnl_net {
47         struct cflayer chnl;
48         struct net_device_stats stats;
49         struct caif_connect_request conn_req;
50         struct list_head list_field;
51         struct net_device *netdev;
52         char name[256];
53         wait_queue_head_t netmgmt_wq;
54         /* Flow status to remember and control the transmission. */
55         bool flowenabled;
56         enum caif_states state;
57 };
58
59 static void robust_list_del(struct list_head *delete_node)
60 {
61         struct list_head *list_node;
62         struct list_head *n;
63         ASSERT_RTNL();
64         list_for_each_safe(list_node, n, &chnl_net_list) {
65                 if (list_node == delete_node) {
66                         list_del(list_node);
67                         return;
68                 }
69         }
70         WARN_ON(1);
71 }
72
73 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
74 {
75         struct sk_buff *skb;
76         struct chnl_net *priv;
77         int pktlen;
78         const u8 *ip_version;
79         u8 buf;
80
81         priv = container_of(layr, struct chnl_net, chnl);
82         if (!priv)
83                 return -EINVAL;
84
85         skb = (struct sk_buff *) cfpkt_tonative(pkt);
86
87         /* Get length of CAIF packet. */
88         pktlen = skb->len;
89
90         /* Pass some minimum information and
91          * send the packet to the net stack.
92          */
93         skb->dev = priv->netdev;
94
95         /* check the version of IP */
96         ip_version = skb_header_pointer(skb, 0, 1, &buf);
97         if (!ip_version) {
98                 kfree_skb(skb);
99                 return -EINVAL;
100         }
101
102         switch (*ip_version >> 4) {
103         case 4:
104                 skb->protocol = htons(ETH_P_IP);
105                 break;
106         case 6:
107                 skb->protocol = htons(ETH_P_IPV6);
108                 break;
109         default:
110                 kfree_skb(skb);
111                 priv->netdev->stats.rx_errors++;
112                 return -EINVAL;
113         }
114
115         /* If we change the header in loop mode, the checksum is corrupted. */
116         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
117                 skb->ip_summed = CHECKSUM_UNNECESSARY;
118         else
119                 skb->ip_summed = CHECKSUM_NONE;
120
121         if (in_interrupt())
122                 netif_rx(skb);
123         else
124                 netif_rx_ni(skb);
125
126         /* Update statistics. */
127         priv->netdev->stats.rx_packets++;
128         priv->netdev->stats.rx_bytes += pktlen;
129
130         return 0;
131 }
132
133 static int delete_device(struct chnl_net *dev)
134 {
135         ASSERT_RTNL();
136         if (dev->netdev)
137                 unregister_netdevice(dev->netdev);
138         return 0;
139 }
140
141 static void close_work(struct work_struct *work)
142 {
143         struct chnl_net *dev = NULL;
144         struct list_head *list_node;
145         struct list_head *_tmp;
146
147         rtnl_lock();
148         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
149                 dev = list_entry(list_node, struct chnl_net, list_field);
150                 if (dev->state == CAIF_SHUTDOWN)
151                         dev_close(dev->netdev);
152         }
153         rtnl_unlock();
154 }
155 static DECLARE_WORK(close_worker, close_work);
156
157 static void chnl_hold(struct cflayer *lyr)
158 {
159         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
160         dev_hold(priv->netdev);
161 }
162
163 static void chnl_put(struct cflayer *lyr)
164 {
165         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
166         dev_put(priv->netdev);
167 }
168
169 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
170                              int phyid)
171 {
172         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
173         pr_debug("NET flowctrl func called flow: %s\n",
174                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
175                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
176                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
177                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
178                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
179                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
180                  "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
181
182
183
184         switch (flow) {
185         case CAIF_CTRLCMD_FLOW_OFF_IND:
186                 priv->flowenabled = false;
187                 netif_stop_queue(priv->netdev);
188                 break;
189         case CAIF_CTRLCMD_DEINIT_RSP:
190                 priv->state = CAIF_DISCONNECTED;
191                 break;
192         case CAIF_CTRLCMD_INIT_FAIL_RSP:
193                 priv->state = CAIF_DISCONNECTED;
194                 wake_up_interruptible(&priv->netmgmt_wq);
195                 break;
196         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
197                 priv->state = CAIF_SHUTDOWN;
198                 netif_tx_disable(priv->netdev);
199                 schedule_work(&close_worker);
200                 break;
201         case CAIF_CTRLCMD_FLOW_ON_IND:
202                 priv->flowenabled = true;
203                 netif_wake_queue(priv->netdev);
204                 break;
205         case CAIF_CTRLCMD_INIT_RSP:
206                 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
207                 priv->state = CAIF_CONNECTED;
208                 priv->flowenabled = true;
209                 netif_wake_queue(priv->netdev);
210                 wake_up_interruptible(&priv->netmgmt_wq);
211                 break;
212         default:
213                 break;
214         }
215 }
216
217 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
218 {
219         struct chnl_net *priv;
220         struct cfpkt *pkt = NULL;
221         int len;
222         int result = -1;
223         /* Get our private data. */
224         priv = netdev_priv(dev);
225
226         if (skb->len > priv->netdev->mtu) {
227                 pr_warn("Size of skb exceeded MTU\n");
228                 kfree_skb(skb);
229                 dev->stats.tx_errors++;
230                 return NETDEV_TX_OK;
231         }
232
233         if (!priv->flowenabled) {
234                 pr_debug("dropping packets flow off\n");
235                 kfree_skb(skb);
236                 dev->stats.tx_dropped++;
237                 return NETDEV_TX_OK;
238         }
239
240         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
241                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
242
243         /* Store original SKB length. */
244         len = skb->len;
245
246         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
247
248         /* Send the packet down the stack. */
249         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
250         if (result) {
251                 dev->stats.tx_dropped++;
252                 return NETDEV_TX_OK;
253         }
254
255         /* Update statistics. */
256         dev->stats.tx_packets++;
257         dev->stats.tx_bytes += len;
258
259         return NETDEV_TX_OK;
260 }
261
262 static int chnl_net_open(struct net_device *dev)
263 {
264         struct chnl_net *priv = NULL;
265         int result = -1;
266         int llifindex, headroom, tailroom, mtu;
267         struct net_device *lldev;
268         ASSERT_RTNL();
269         priv = netdev_priv(dev);
270         if (!priv) {
271                 pr_debug("chnl_net_open: no priv\n");
272                 return -ENODEV;
273         }
274
275         if (priv->state != CAIF_CONNECTING) {
276                 priv->state = CAIF_CONNECTING;
277                 result = caif_connect_client(dev_net(dev), &priv->conn_req,
278                                                 &priv->chnl, &llifindex,
279                                                 &headroom, &tailroom);
280                 if (result != 0) {
281                                 pr_debug("err: "
282                                          "Unable to register and open device,"
283                                          " Err:%d\n",
284                                          result);
285                                 goto error;
286                 }
287
288                 lldev = dev_get_by_index(dev_net(dev), llifindex);
289
290                 if (lldev == NULL) {
291                         pr_debug("no interface?\n");
292                         result = -ENODEV;
293                         goto error;
294                 }
295
296                 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
297                 dev->hard_header_len = headroom + lldev->hard_header_len +
298                         lldev->needed_tailroom;
299
300                 /*
301                  * MTU, head-room etc is not know before we have a
302                  * CAIF link layer device available. MTU calculation may
303                  * override initial RTNL configuration.
304                  * MTU is minimum of current mtu, link layer mtu pluss
305                  * CAIF head and tail, and PDP GPRS contexts max MTU.
306                  */
307                 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
308                 mtu = min_t(int, GPRS_PDP_MTU, mtu);
309                 dev_set_mtu(dev, mtu);
310                 dev_put(lldev);
311
312                 if (mtu < 100) {
313                         pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
314                         result = -ENODEV;
315                         goto error;
316                 }
317         }
318
319         rtnl_unlock();  /* Release RTNL lock during connect wait */
320
321         result = wait_event_interruptible_timeout(priv->netmgmt_wq,
322                                                 priv->state != CAIF_CONNECTING,
323                                                 CONNECT_TIMEOUT);
324
325         rtnl_lock();
326
327         if (result == -ERESTARTSYS) {
328                 pr_debug("wait_event_interruptible woken by a signal\n");
329                 result = -ERESTARTSYS;
330                 goto error;
331         }
332
333         if (result == 0) {
334                 pr_debug("connect timeout\n");
335                 caif_disconnect_client(dev_net(dev), &priv->chnl);
336                 priv->state = CAIF_DISCONNECTED;
337                 pr_debug("state disconnected\n");
338                 result = -ETIMEDOUT;
339                 goto error;
340         }
341
342         if (priv->state != CAIF_CONNECTED) {
343                 pr_debug("connect failed\n");
344                 result = -ECONNREFUSED;
345                 goto error;
346         }
347         pr_debug("CAIF Netdevice connected\n");
348         return 0;
349
350 error:
351         caif_disconnect_client(dev_net(dev), &priv->chnl);
352         priv->state = CAIF_DISCONNECTED;
353         pr_debug("state disconnected\n");
354         return result;
355
356 }
357
358 static int chnl_net_stop(struct net_device *dev)
359 {
360         struct chnl_net *priv;
361
362         ASSERT_RTNL();
363         priv = netdev_priv(dev);
364         priv->state = CAIF_DISCONNECTED;
365         caif_disconnect_client(dev_net(dev), &priv->chnl);
366         return 0;
367 }
368
369 static int chnl_net_init(struct net_device *dev)
370 {
371         struct chnl_net *priv;
372         ASSERT_RTNL();
373         priv = netdev_priv(dev);
374         strncpy(priv->name, dev->name, sizeof(priv->name));
375         return 0;
376 }
377
378 static void chnl_net_uninit(struct net_device *dev)
379 {
380         struct chnl_net *priv;
381         ASSERT_RTNL();
382         priv = netdev_priv(dev);
383         robust_list_del(&priv->list_field);
384 }
385
386 static const struct net_device_ops netdev_ops = {
387         .ndo_open = chnl_net_open,
388         .ndo_stop = chnl_net_stop,
389         .ndo_init = chnl_net_init,
390         .ndo_uninit = chnl_net_uninit,
391         .ndo_start_xmit = chnl_net_start_xmit,
392 };
393
394 static void chnl_net_destructor(struct net_device *dev)
395 {
396         struct chnl_net *priv = netdev_priv(dev);
397         caif_free_client(&priv->chnl);
398         free_netdev(dev);
399 }
400
401 static void ipcaif_net_setup(struct net_device *dev)
402 {
403         struct chnl_net *priv;
404         dev->netdev_ops = &netdev_ops;
405         dev->destructor = chnl_net_destructor;
406         dev->flags |= IFF_NOARP;
407         dev->flags |= IFF_POINTOPOINT;
408         dev->mtu = GPRS_PDP_MTU;
409         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
410
411         priv = netdev_priv(dev);
412         priv->chnl.receive = chnl_recv_cb;
413         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
414         priv->netdev = dev;
415         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
416         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
417         priv->conn_req.priority = CAIF_PRIO_LOW;
418         /* Insert illegal value */
419         priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
420         priv->flowenabled = false;
421
422         init_waitqueue_head(&priv->netmgmt_wq);
423 }
424
425
426 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
427 {
428         struct chnl_net *priv;
429         u8 loop;
430         priv = netdev_priv(dev);
431         if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
432                         priv->conn_req.sockaddr.u.dgm.connection_id) ||
433             nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
434                         priv->conn_req.sockaddr.u.dgm.connection_id))
435                 goto nla_put_failure;
436         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
437         if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
438                 goto nla_put_failure;
439         return 0;
440 nla_put_failure:
441         return -EMSGSIZE;
442
443 }
444
445 static void caif_netlink_parms(struct nlattr *data[],
446                                struct caif_connect_request *conn_req)
447 {
448         if (!data) {
449                 pr_warn("no params data found\n");
450                 return;
451         }
452         if (data[IFLA_CAIF_IPV4_CONNID])
453                 conn_req->sockaddr.u.dgm.connection_id =
454                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
455         if (data[IFLA_CAIF_IPV6_CONNID])
456                 conn_req->sockaddr.u.dgm.connection_id =
457                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
458         if (data[IFLA_CAIF_LOOPBACK]) {
459                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
460                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
461                 else
462                         conn_req->protocol = CAIFPROTO_DATAGRAM;
463         }
464 }
465
466 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
467                           struct nlattr *tb[], struct nlattr *data[])
468 {
469         int ret;
470         struct chnl_net *caifdev;
471         ASSERT_RTNL();
472         caifdev = netdev_priv(dev);
473         caif_netlink_parms(data, &caifdev->conn_req);
474         dev_net_set(caifdev->netdev, src_net);
475
476         ret = register_netdevice(dev);
477         if (ret)
478                 pr_warn("device rtml registration failed\n");
479         else
480                 list_add(&caifdev->list_field, &chnl_net_list);
481
482         /* Use ifindex as connection id, and use loopback channel default. */
483         if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
484                 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
485                 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
486         }
487         return ret;
488 }
489
490 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
491                              struct nlattr *data[])
492 {
493         struct chnl_net *caifdev;
494         ASSERT_RTNL();
495         caifdev = netdev_priv(dev);
496         caif_netlink_parms(data, &caifdev->conn_req);
497         netdev_state_change(dev);
498         return 0;
499 }
500
501 static size_t ipcaif_get_size(const struct net_device *dev)
502 {
503         return
504                 /* IFLA_CAIF_IPV4_CONNID */
505                 nla_total_size(4) +
506                 /* IFLA_CAIF_IPV6_CONNID */
507                 nla_total_size(4) +
508                 /* IFLA_CAIF_LOOPBACK */
509                 nla_total_size(2) +
510                 0;
511 }
512
513 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
514         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
515         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
516         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
517 };
518
519
520 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
521         .kind           = "caif",
522         .priv_size      = sizeof(struct chnl_net),
523         .setup          = ipcaif_net_setup,
524         .maxtype        = IFLA_CAIF_MAX,
525         .policy         = ipcaif_policy,
526         .newlink        = ipcaif_newlink,
527         .changelink     = ipcaif_changelink,
528         .get_size       = ipcaif_get_size,
529         .fill_info      = ipcaif_fill_info,
530
531 };
532
533 static int __init chnl_init_module(void)
534 {
535         return rtnl_link_register(&ipcaif_link_ops);
536 }
537
538 static void __exit chnl_exit_module(void)
539 {
540         struct chnl_net *dev = NULL;
541         struct list_head *list_node;
542         struct list_head *_tmp;
543         rtnl_link_unregister(&ipcaif_link_ops);
544         rtnl_lock();
545         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
546                 dev = list_entry(list_node, struct chnl_net, list_field);
547                 list_del(list_node);
548                 delete_device(dev);
549         }
550         rtnl_unlock();
551 }
552
553 module_init(chnl_init_module);
554 module_exit(chnl_exit_module);