1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) ST-Ericsson AB 2010
4 * Authors: Sjur Brendeland
5 * Daniel Martensson
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_DESCRIPTION("ST-Ericsson CAIF modem protocol GPRS network device");
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 caif_connect_request conn_req;
48 struct list_head list_field;
49 struct net_device *netdev;
50 char name[256];
51 wait_queue_head_t netmgmt_wq;
52 /* Flow status to remember and control the transmission. */
53 bool flowenabled;
54 enum caif_states state;
55 };
56
57 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
58 {
59 struct sk_buff *skb;
60 struct chnl_net *priv;
61 int pktlen;
62 const u8 *ip_version;
63 u8 buf;
64
65 priv = container_of(layr, struct chnl_net, chnl);
66
67 skb = (struct sk_buff *) cfpkt_tonative(pkt);
68
69 /* Get length of CAIF packet. */
70 pktlen = skb->len;
71
72 /* Pass some minimum information and
73 * send the packet to the net stack.
74 */
75 skb->dev = priv->netdev;
76
77 /* check the version of IP */
78 ip_version = skb_header_pointer(skb, 0, 1, &buf);
79 if (!ip_version) {
80 kfree_skb(skb);
81 return -EINVAL;
82 }
83
84 switch (*ip_version >> 4) {
85 case 4:
86 skb->protocol = htons(ETH_P_IP);
87 break;
88 case 6:
89 skb->protocol = htons(ETH_P_IPV6);
90 break;
91 default:
92 kfree_skb(skb);
93 priv->netdev->stats.rx_errors++;
94 return -EINVAL;
95 }
96
97 /* If we change the header in loop mode, the checksum is corrupted. */
98 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
99 skb->ip_summed = CHECKSUM_UNNECESSARY;
100 else
101 skb->ip_summed = CHECKSUM_NONE;
102
103 netif_rx(skb);
104
105 /* Update statistics. */
106 priv->netdev->stats.rx_packets++;
107 priv->netdev->stats.rx_bytes += pktlen;
108
109 return 0;
110 }
111
112 static int delete_device(struct chnl_net *dev)
113 {
114 ASSERT_RTNL();
115 if (dev->netdev)
116 unregister_netdevice(dev->netdev);
117 return 0;
118 }
119
120 static void close_work(struct work_struct *work)
121 {
122 struct chnl_net *dev = NULL;
123 struct list_head *list_node;
124 struct list_head *_tmp;
125
126 rtnl_lock();
127 list_for_each_safe(list_node, _tmp, &chnl_net_list) {
128 dev = list_entry(list_node, struct chnl_net, list_field);
129 if (dev->state == CAIF_SHUTDOWN)
130 dev_close(dev->netdev);
131 }
132 rtnl_unlock();
133 }
134 static DECLARE_WORK(close_worker, close_work);
135
136 static void chnl_hold(struct cflayer *lyr)
137 {
138 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
139 dev_hold(priv->netdev);
140 }
141
142 static void chnl_put(struct cflayer *lyr)
143 {
144 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
145 dev_put(priv->netdev);
146 }
147
148 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
149 int phyid)
150 {
151 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
152 pr_debug("NET flowctrl func called flow: %s\n",
153 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
154 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
155 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
156 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
157 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
158 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
159 "REMOTE_SHUTDOWN" : "UNKNOWN CTRL COMMAND");
160
161
162
163 switch (flow) {
164 case CAIF_CTRLCMD_FLOW_OFF_IND:
165 priv->flowenabled = false;
166 netif_stop_queue(priv->netdev);
167 break;
168 case CAIF_CTRLCMD_DEINIT_RSP:
169 priv->state = CAIF_DISCONNECTED;
170 break;
171 case CAIF_CTRLCMD_INIT_FAIL_RSP:
172 priv->state = CAIF_DISCONNECTED;
173 wake_up_interruptible(&priv->netmgmt_wq);
174 break;
175 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
176 priv->state = CAIF_SHUTDOWN;
177 netif_tx_disable(priv->netdev);
178 schedule_work(&close_worker);
179 break;
180 case CAIF_CTRLCMD_FLOW_ON_IND:
181 priv->flowenabled = true;
182 netif_wake_queue(priv->netdev);
183 break;
184 case CAIF_CTRLCMD_INIT_RSP:
185 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
186 priv->state = CAIF_CONNECTED;
187 priv->flowenabled = true;
188 netif_wake_queue(priv->netdev);
189 wake_up_interruptible(&priv->netmgmt_wq);
190 break;
191 default:
192 break;
193 }
194 }
195
196 static netdev_tx_t chnl_net_start_xmit(struct sk_buff *skb,
197 struct net_device *dev)
198 {
199 struct chnl_net *priv;
200 struct cfpkt *pkt = NULL;
201 int len;
202 int result = -1;
203 /* Get our private data. */
204 priv = netdev_priv(dev);
205
206 if (skb->len > priv->netdev->mtu) {
207 pr_warn("Size of skb exceeded MTU\n");
208 kfree_skb(skb);
209 dev->stats.tx_errors++;
210 return NETDEV_TX_OK;
211 }
212
213 if (!priv->flowenabled) {
214 pr_debug("dropping packets flow off\n");
215 kfree_skb(skb);
216 dev->stats.tx_dropped++;
217 return NETDEV_TX_OK;
218 }
219
220 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
221 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
222
223 /* Store original SKB length. */
224 len = skb->len;
225
226 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
227
228 /* Send the packet down the stack. */
229 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
230 if (result) {
231 dev->stats.tx_dropped++;
232 return NETDEV_TX_OK;
233 }
234
235 /* Update statistics. */
236 dev->stats.tx_packets++;
237 dev->stats.tx_bytes += len;
238
239 return NETDEV_TX_OK;
240 }
241
242 static int chnl_net_open(struct net_device *dev)
243 {
244 struct chnl_net *priv = NULL;
245 int result = -1;
246 int llifindex, headroom, tailroom, mtu;
247 struct net_device *lldev;
248 ASSERT_RTNL();
249 priv = netdev_priv(dev);
250 if (!priv) {
251 pr_debug("chnl_net_open: no priv\n");
252 return -ENODEV;
253 }
254
255 if (priv->state != CAIF_CONNECTING) {
256 priv->state = CAIF_CONNECTING;
257 result = caif_connect_client(dev_net(dev), &priv->conn_req,
258 &priv->chnl, &llifindex,
259 &headroom, &tailroom);
260 if (result != 0) {
261 pr_debug("err: "
262 "Unable to register and open device,"
263 " Err:%d\n",
264 result);
265 goto error;
266 }
267
268 lldev = __dev_get_by_index(dev_net(dev), llifindex);
269
270 if (lldev == NULL) {
271 pr_debug("no interface?\n");
272 result = -ENODEV;
273 goto error;
274 }
275
276 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
277 dev->hard_header_len = headroom + lldev->hard_header_len +
278 lldev->needed_tailroom;
279
280 /*
281 * MTU, head-room etc is not know before we have a
282 * CAIF link layer device available. MTU calculation may
283 * override initial RTNL configuration.
284 * MTU is minimum of current mtu, link layer mtu pluss
285 * CAIF head and tail, and PDP GPRS contexts max MTU.
286 */
287 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
288 mtu = min_t(int, GPRS_PDP_MTU, mtu);
289 dev_set_mtu(dev, mtu);
290
291 if (mtu < 100) {
292 pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
293 result = -ENODEV;
294 goto error;
295 }
296 }
297
298 rtnl_unlock(); /* Release RTNL lock during connect wait */
299
300 result = wait_event_interruptible_timeout(priv->netmgmt_wq,
301 priv->state != CAIF_CONNECTING,
302 CONNECT_TIMEOUT);
303
304 rtnl_lock();
305
306 if (result == -ERESTARTSYS) {
307 pr_debug("wait_event_interruptible woken by a signal\n");
308 result = -ERESTARTSYS;
309 goto error;
310 }
311
312 if (result == 0) {
313 pr_debug("connect timeout\n");
314 result = -ETIMEDOUT;
315 goto error;
316 }
317
318 if (priv->state != CAIF_CONNECTED) {
319 pr_debug("connect failed\n");
320 result = -ECONNREFUSED;
321 goto error;
322 }
323 pr_debug("CAIF Netdevice connected\n");
324 return 0;
325
326 error:
327 caif_disconnect_client(dev_net(dev), &priv->chnl);
328 priv->state = CAIF_DISCONNECTED;
329 pr_debug("state disconnected\n");
330 return result;
331
332 }
333
334 static int chnl_net_stop(struct net_device *dev)
335 {
336 struct chnl_net *priv;
337
338 ASSERT_RTNL();
339 priv = netdev_priv(dev);
340 priv->state = CAIF_DISCONNECTED;
341 caif_disconnect_client(dev_net(dev), &priv->chnl);
342 return 0;
343 }
344
345 static int chnl_net_init(struct net_device *dev)
346 {
347 struct chnl_net *priv;
348 ASSERT_RTNL();
349 priv = netdev_priv(dev);
350 strncpy(priv->name, dev->name, sizeof(priv->name));
351 INIT_LIST_HEAD(&priv->list_field);
352 return 0;
353 }
354
355 static void chnl_net_uninit(struct net_device *dev)
356 {
357 struct chnl_net *priv;
358 ASSERT_RTNL();
359 priv = netdev_priv(dev);
360 list_del_init(&priv->list_field);
361 }
362
363 static const struct net_device_ops netdev_ops = {
364 .ndo_open = chnl_net_open,
365 .ndo_stop = chnl_net_stop,
366 .ndo_init = chnl_net_init,
367 .ndo_uninit = chnl_net_uninit,
368 .ndo_start_xmit = chnl_net_start_xmit,
369 };
370
371 static void chnl_net_destructor(struct net_device *dev)
372 {
373 struct chnl_net *priv = netdev_priv(dev);
374 caif_free_client(&priv->chnl);
375 }
376
377 static void ipcaif_net_setup(struct net_device *dev)
378 {
379 struct chnl_net *priv;
380 dev->netdev_ops = &netdev_ops;
381 dev->needs_free_netdev = true;
382 dev->priv_destructor = chnl_net_destructor;
383 dev->flags |= IFF_NOARP;
384 dev->flags |= IFF_POINTOPOINT;
385 dev->mtu = GPRS_PDP_MTU;
386 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
387
388 priv = netdev_priv(dev);
389 priv->chnl.receive = chnl_recv_cb;
390 priv->chnl.ctrlcmd = chnl_flowctrl_cb;
391 priv->netdev = dev;
392 priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
393 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
394 priv->conn_req.priority = CAIF_PRIO_LOW;
395 /* Insert illegal value */
396 priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
397 priv->flowenabled = false;
398
399 init_waitqueue_head(&priv->netmgmt_wq);
400 }
401
402
403 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
404 {
405 struct chnl_net *priv;
406 u8 loop;
407 priv = netdev_priv(dev);
408 if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
409 priv->conn_req.sockaddr.u.dgm.connection_id) ||
410 nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
411 priv->conn_req.sockaddr.u.dgm.connection_id))
412 goto nla_put_failure;
413 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
414 if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
415 goto nla_put_failure;
416 return 0;
417 nla_put_failure:
418 return -EMSGSIZE;
419
420 }
421
422 static void caif_netlink_parms(struct nlattr *data[],
423 struct caif_connect_request *conn_req)
424 {
425 if (!data) {
426 pr_warn("no params data found\n");
427 return;
428 }
429 if (data[IFLA_CAIF_IPV4_CONNID])
430 conn_req->sockaddr.u.dgm.connection_id =
431 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
432 if (data[IFLA_CAIF_IPV6_CONNID])
433 conn_req->sockaddr.u.dgm.connection_id =
434 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
435 if (data[IFLA_CAIF_LOOPBACK]) {
436 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
437 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
438 else
439 conn_req->protocol = CAIFPROTO_DATAGRAM;
440 }
441 }
442
443 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
444 struct nlattr *tb[], struct nlattr *data[],
445 struct netlink_ext_ack *extack)
446 {
447 int ret;
448 struct chnl_net *caifdev;
449 ASSERT_RTNL();
450 caifdev = netdev_priv(dev);
451 caif_netlink_parms(data, &caifdev->conn_req);
452
453 ret = register_netdevice(dev);
454 if (ret)
455 pr_warn("device rtml registration failed\n");
456 else
457 list_add(&caifdev->list_field, &chnl_net_list);
458
459 /* Use ifindex as connection id, and use loopback channel default. */
460 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
461 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
462 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
463 }
464 return ret;
465 }
466
467 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
468 struct nlattr *data[],
469 struct netlink_ext_ack *extack)
470 {
471 struct chnl_net *caifdev;
472 ASSERT_RTNL();
473 caifdev = netdev_priv(dev);
474 caif_netlink_parms(data, &caifdev->conn_req);
475 netdev_state_change(dev);
476 return 0;
477 }
478
479 static size_t ipcaif_get_size(const struct net_device *dev)
480 {
481 return
482 /* IFLA_CAIF_IPV4_CONNID */
483 nla_total_size(4) +
484 /* IFLA_CAIF_IPV6_CONNID */
485 nla_total_size(4) +
486 /* IFLA_CAIF_LOOPBACK */
487 nla_total_size(2) +
488 0;
489 }
490
491 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
492 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 },
493 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 },
494 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 }
495 };
496
497
498 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
499 .kind = "caif",
500 .priv_size = sizeof(struct chnl_net),
501 .setup = ipcaif_net_setup,
502 .maxtype = IFLA_CAIF_MAX,
503 .policy = ipcaif_policy,
504 .newlink = ipcaif_newlink,
505 .changelink = ipcaif_changelink,
506 .get_size = ipcaif_get_size,
507 .fill_info = ipcaif_fill_info,
508
509 };
510
511 static int __init chnl_init_module(void)
512 {
513 return rtnl_link_register(&ipcaif_link_ops);
514 }
515
516 static void __exit chnl_exit_module(void)
517 {
518 struct chnl_net *dev = NULL;
519 struct list_head *list_node;
520 struct list_head *_tmp;
521 rtnl_link_unregister(&ipcaif_link_ops);
522 rtnl_lock();
523 list_for_each_safe(list_node, _tmp, &chnl_net_list) {
524 dev = list_entry(list_node, struct chnl_net, list_field);
525 list_del_init(list_node);
526 delete_device(dev);
527 }
528 rtnl_unlock();
529 }
530
531 module_init(chnl_init_module);
532 module_exit(chnl_exit_module);
533
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