GNU Linux-libre 4.19.211-gnu1
[releases.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/init.h>
12 #include <linux/module.h>
13 #include <linux/netdevice.h>
14 #include <linux/if_ether.h>
15 #include <linux/ip.h>
16 #include <linux/sched.h>
17 #include <linux/sockios.h>
18 #include <linux/caif/if_caif.h>
19 #include <net/rtnetlink.h>
20 #include <net/caif/caif_layer.h>
21 #include <net/caif/cfpkt.h>
22 #include <net/caif/caif_dev.h>
23
24 /* GPRS PDP connection has MTU to 1500 */
25 #define GPRS_PDP_MTU 1500
26 /* 5 sec. connect timeout */
27 #define CONNECT_TIMEOUT (5 * HZ)
28 #define CAIF_NET_DEFAULT_QUEUE_LEN 500
29 #define UNDEF_CONNID 0xffffffff
30
31 /*This list is protected by the rtnl lock. */
32 static LIST_HEAD(chnl_net_list);
33
34 MODULE_LICENSE("GPL");
35 MODULE_ALIAS_RTNL_LINK("caif");
36
37 enum caif_states {
38         CAIF_CONNECTED          = 1,
39         CAIF_CONNECTING,
40         CAIF_DISCONNECTED,
41         CAIF_SHUTDOWN
42 };
43
44 struct chnl_net {
45         struct cflayer chnl;
46         struct caif_connect_request conn_req;
47         struct list_head list_field;
48         struct net_device *netdev;
49         char name[256];
50         wait_queue_head_t netmgmt_wq;
51         /* Flow status to remember and control the transmission. */
52         bool flowenabled;
53         enum caif_states state;
54 };
55
56 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
57 {
58         struct sk_buff *skb;
59         struct chnl_net *priv;
60         int pktlen;
61         const u8 *ip_version;
62         u8 buf;
63
64         priv = container_of(layr, struct chnl_net, chnl);
65         if (!priv)
66                 return -EINVAL;
67
68         skb = (struct sk_buff *) cfpkt_tonative(pkt);
69
70         /* Get length of CAIF packet. */
71         pktlen = skb->len;
72
73         /* Pass some minimum information and
74          * send the packet to the net stack.
75          */
76         skb->dev = priv->netdev;
77
78         /* check the version of IP */
79         ip_version = skb_header_pointer(skb, 0, 1, &buf);
80         if (!ip_version) {
81                 kfree_skb(skb);
82                 return -EINVAL;
83         }
84
85         switch (*ip_version >> 4) {
86         case 4:
87                 skb->protocol = htons(ETH_P_IP);
88                 break;
89         case 6:
90                 skb->protocol = htons(ETH_P_IPV6);
91                 break;
92         default:
93                 kfree_skb(skb);
94                 priv->netdev->stats.rx_errors++;
95                 return -EINVAL;
96         }
97
98         /* If we change the header in loop mode, the checksum is corrupted. */
99         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
100                 skb->ip_summed = CHECKSUM_UNNECESSARY;
101         else
102                 skb->ip_summed = CHECKSUM_NONE;
103
104         if (in_interrupt())
105                 netif_rx(skb);
106         else
107                 netif_rx_ni(skb);
108
109         /* Update statistics. */
110         priv->netdev->stats.rx_packets++;
111         priv->netdev->stats.rx_bytes += pktlen;
112
113         return 0;
114 }
115
116 static int delete_device(struct chnl_net *dev)
117 {
118         ASSERT_RTNL();
119         if (dev->netdev)
120                 unregister_netdevice(dev->netdev);
121         return 0;
122 }
123
124 static void close_work(struct work_struct *work)
125 {
126         struct chnl_net *dev = NULL;
127         struct list_head *list_node;
128         struct list_head *_tmp;
129
130         rtnl_lock();
131         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
132                 dev = list_entry(list_node, struct chnl_net, list_field);
133                 if (dev->state == CAIF_SHUTDOWN)
134                         dev_close(dev->netdev);
135         }
136         rtnl_unlock();
137 }
138 static DECLARE_WORK(close_worker, close_work);
139
140 static void chnl_hold(struct cflayer *lyr)
141 {
142         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
143         dev_hold(priv->netdev);
144 }
145
146 static void chnl_put(struct cflayer *lyr)
147 {
148         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
149         dev_put(priv->netdev);
150 }
151
152 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
153                              int phyid)
154 {
155         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
156         pr_debug("NET flowctrl func called flow: %s\n",
157                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
158                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
159                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
160                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
161                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
162                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
163                  "REMOTE_SHUTDOWN" : "UNKNOWN CTRL COMMAND");
164
165
166
167         switch (flow) {
168         case CAIF_CTRLCMD_FLOW_OFF_IND:
169                 priv->flowenabled = false;
170                 netif_stop_queue(priv->netdev);
171                 break;
172         case CAIF_CTRLCMD_DEINIT_RSP:
173                 priv->state = CAIF_DISCONNECTED;
174                 break;
175         case CAIF_CTRLCMD_INIT_FAIL_RSP:
176                 priv->state = CAIF_DISCONNECTED;
177                 wake_up_interruptible(&priv->netmgmt_wq);
178                 break;
179         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
180                 priv->state = CAIF_SHUTDOWN;
181                 netif_tx_disable(priv->netdev);
182                 schedule_work(&close_worker);
183                 break;
184         case CAIF_CTRLCMD_FLOW_ON_IND:
185                 priv->flowenabled = true;
186                 netif_wake_queue(priv->netdev);
187                 break;
188         case CAIF_CTRLCMD_INIT_RSP:
189                 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
190                 priv->state = CAIF_CONNECTED;
191                 priv->flowenabled = true;
192                 netif_wake_queue(priv->netdev);
193                 wake_up_interruptible(&priv->netmgmt_wq);
194                 break;
195         default:
196                 break;
197         }
198 }
199
200 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
201 {
202         struct chnl_net *priv;
203         struct cfpkt *pkt = NULL;
204         int len;
205         int result = -1;
206         /* Get our private data. */
207         priv = netdev_priv(dev);
208
209         if (skb->len > priv->netdev->mtu) {
210                 pr_warn("Size of skb exceeded MTU\n");
211                 kfree_skb(skb);
212                 dev->stats.tx_errors++;
213                 return NETDEV_TX_OK;
214         }
215
216         if (!priv->flowenabled) {
217                 pr_debug("dropping packets flow off\n");
218                 kfree_skb(skb);
219                 dev->stats.tx_dropped++;
220                 return NETDEV_TX_OK;
221         }
222
223         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
224                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
225
226         /* Store original SKB length. */
227         len = skb->len;
228
229         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
230
231         /* Send the packet down the stack. */
232         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
233         if (result) {
234                 dev->stats.tx_dropped++;
235                 return NETDEV_TX_OK;
236         }
237
238         /* Update statistics. */
239         dev->stats.tx_packets++;
240         dev->stats.tx_bytes += len;
241
242         return NETDEV_TX_OK;
243 }
244
245 static int chnl_net_open(struct net_device *dev)
246 {
247         struct chnl_net *priv = NULL;
248         int result = -1;
249         int llifindex, headroom, tailroom, mtu;
250         struct net_device *lldev;
251         ASSERT_RTNL();
252         priv = netdev_priv(dev);
253         if (!priv) {
254                 pr_debug("chnl_net_open: no priv\n");
255                 return -ENODEV;
256         }
257
258         if (priv->state != CAIF_CONNECTING) {
259                 priv->state = CAIF_CONNECTING;
260                 result = caif_connect_client(dev_net(dev), &priv->conn_req,
261                                                 &priv->chnl, &llifindex,
262                                                 &headroom, &tailroom);
263                 if (result != 0) {
264                                 pr_debug("err: "
265                                          "Unable to register and open device,"
266                                          " Err:%d\n",
267                                          result);
268                                 goto error;
269                 }
270
271                 lldev = __dev_get_by_index(dev_net(dev), llifindex);
272
273                 if (lldev == NULL) {
274                         pr_debug("no interface?\n");
275                         result = -ENODEV;
276                         goto error;
277                 }
278
279                 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
280                 dev->hard_header_len = headroom + lldev->hard_header_len +
281                         lldev->needed_tailroom;
282
283                 /*
284                  * MTU, head-room etc is not know before we have a
285                  * CAIF link layer device available. MTU calculation may
286                  * override initial RTNL configuration.
287                  * MTU is minimum of current mtu, link layer mtu pluss
288                  * CAIF head and tail, and PDP GPRS contexts max MTU.
289                  */
290                 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
291                 mtu = min_t(int, GPRS_PDP_MTU, mtu);
292                 dev_set_mtu(dev, mtu);
293
294                 if (mtu < 100) {
295                         pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
296                         result = -ENODEV;
297                         goto error;
298                 }
299         }
300
301         rtnl_unlock();  /* Release RTNL lock during connect wait */
302
303         result = wait_event_interruptible_timeout(priv->netmgmt_wq,
304                                                 priv->state != CAIF_CONNECTING,
305                                                 CONNECT_TIMEOUT);
306
307         rtnl_lock();
308
309         if (result == -ERESTARTSYS) {
310                 pr_debug("wait_event_interruptible woken by a signal\n");
311                 result = -ERESTARTSYS;
312                 goto error;
313         }
314
315         if (result == 0) {
316                 pr_debug("connect timeout\n");
317                 caif_disconnect_client(dev_net(dev), &priv->chnl);
318                 priv->state = CAIF_DISCONNECTED;
319                 pr_debug("state disconnected\n");
320                 result = -ETIMEDOUT;
321                 goto error;
322         }
323
324         if (priv->state != CAIF_CONNECTED) {
325                 pr_debug("connect failed\n");
326                 result = -ECONNREFUSED;
327                 goto error;
328         }
329         pr_debug("CAIF Netdevice connected\n");
330         return 0;
331
332 error:
333         caif_disconnect_client(dev_net(dev), &priv->chnl);
334         priv->state = CAIF_DISCONNECTED;
335         pr_debug("state disconnected\n");
336         return result;
337
338 }
339
340 static int chnl_net_stop(struct net_device *dev)
341 {
342         struct chnl_net *priv;
343
344         ASSERT_RTNL();
345         priv = netdev_priv(dev);
346         priv->state = CAIF_DISCONNECTED;
347         caif_disconnect_client(dev_net(dev), &priv->chnl);
348         return 0;
349 }
350
351 static int chnl_net_init(struct net_device *dev)
352 {
353         struct chnl_net *priv;
354         ASSERT_RTNL();
355         priv = netdev_priv(dev);
356         strncpy(priv->name, dev->name, sizeof(priv->name));
357         INIT_LIST_HEAD(&priv->list_field);
358         return 0;
359 }
360
361 static void chnl_net_uninit(struct net_device *dev)
362 {
363         struct chnl_net *priv;
364         ASSERT_RTNL();
365         priv = netdev_priv(dev);
366         list_del_init(&priv->list_field);
367 }
368
369 static const struct net_device_ops netdev_ops = {
370         .ndo_open = chnl_net_open,
371         .ndo_stop = chnl_net_stop,
372         .ndo_init = chnl_net_init,
373         .ndo_uninit = chnl_net_uninit,
374         .ndo_start_xmit = chnl_net_start_xmit,
375 };
376
377 static void chnl_net_destructor(struct net_device *dev)
378 {
379         struct chnl_net *priv = netdev_priv(dev);
380         caif_free_client(&priv->chnl);
381 }
382
383 static void ipcaif_net_setup(struct net_device *dev)
384 {
385         struct chnl_net *priv;
386         dev->netdev_ops = &netdev_ops;
387         dev->needs_free_netdev = true;
388         dev->priv_destructor = chnl_net_destructor;
389         dev->flags |= IFF_NOARP;
390         dev->flags |= IFF_POINTOPOINT;
391         dev->mtu = GPRS_PDP_MTU;
392         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
393
394         priv = netdev_priv(dev);
395         priv->chnl.receive = chnl_recv_cb;
396         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
397         priv->netdev = dev;
398         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
399         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
400         priv->conn_req.priority = CAIF_PRIO_LOW;
401         /* Insert illegal value */
402         priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
403         priv->flowenabled = false;
404
405         init_waitqueue_head(&priv->netmgmt_wq);
406 }
407
408
409 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
410 {
411         struct chnl_net *priv;
412         u8 loop;
413         priv = netdev_priv(dev);
414         if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
415                         priv->conn_req.sockaddr.u.dgm.connection_id) ||
416             nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
417                         priv->conn_req.sockaddr.u.dgm.connection_id))
418                 goto nla_put_failure;
419         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
420         if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
421                 goto nla_put_failure;
422         return 0;
423 nla_put_failure:
424         return -EMSGSIZE;
425
426 }
427
428 static void caif_netlink_parms(struct nlattr *data[],
429                                struct caif_connect_request *conn_req)
430 {
431         if (!data) {
432                 pr_warn("no params data found\n");
433                 return;
434         }
435         if (data[IFLA_CAIF_IPV4_CONNID])
436                 conn_req->sockaddr.u.dgm.connection_id =
437                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
438         if (data[IFLA_CAIF_IPV6_CONNID])
439                 conn_req->sockaddr.u.dgm.connection_id =
440                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
441         if (data[IFLA_CAIF_LOOPBACK]) {
442                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
443                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
444                 else
445                         conn_req->protocol = CAIFPROTO_DATAGRAM;
446         }
447 }
448
449 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
450                           struct nlattr *tb[], struct nlattr *data[],
451                           struct netlink_ext_ack *extack)
452 {
453         int ret;
454         struct chnl_net *caifdev;
455         ASSERT_RTNL();
456         caifdev = netdev_priv(dev);
457         caif_netlink_parms(data, &caifdev->conn_req);
458
459         ret = register_netdevice(dev);
460         if (ret)
461                 pr_warn("device rtml registration failed\n");
462         else
463                 list_add(&caifdev->list_field, &chnl_net_list);
464
465         /* Use ifindex as connection id, and use loopback channel default. */
466         if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
467                 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
468                 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
469         }
470         return ret;
471 }
472
473 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
474                              struct nlattr *data[],
475                              struct netlink_ext_ack *extack)
476 {
477         struct chnl_net *caifdev;
478         ASSERT_RTNL();
479         caifdev = netdev_priv(dev);
480         caif_netlink_parms(data, &caifdev->conn_req);
481         netdev_state_change(dev);
482         return 0;
483 }
484
485 static size_t ipcaif_get_size(const struct net_device *dev)
486 {
487         return
488                 /* IFLA_CAIF_IPV4_CONNID */
489                 nla_total_size(4) +
490                 /* IFLA_CAIF_IPV6_CONNID */
491                 nla_total_size(4) +
492                 /* IFLA_CAIF_LOOPBACK */
493                 nla_total_size(2) +
494                 0;
495 }
496
497 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
498         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
499         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
500         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
501 };
502
503
504 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
505         .kind           = "caif",
506         .priv_size      = sizeof(struct chnl_net),
507         .setup          = ipcaif_net_setup,
508         .maxtype        = IFLA_CAIF_MAX,
509         .policy         = ipcaif_policy,
510         .newlink        = ipcaif_newlink,
511         .changelink     = ipcaif_changelink,
512         .get_size       = ipcaif_get_size,
513         .fill_info      = ipcaif_fill_info,
514
515 };
516
517 static int __init chnl_init_module(void)
518 {
519         return rtnl_link_register(&ipcaif_link_ops);
520 }
521
522 static void __exit chnl_exit_module(void)
523 {
524         struct chnl_net *dev = NULL;
525         struct list_head *list_node;
526         struct list_head *_tmp;
527         rtnl_link_unregister(&ipcaif_link_ops);
528         rtnl_lock();
529         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
530                 dev = list_entry(list_node, struct chnl_net, list_field);
531                 list_del_init(list_node);
532                 delete_device(dev);
533         }
534         rtnl_unlock();
535 }
536
537 module_init(chnl_init_module);
538 module_exit(chnl_exit_module);