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_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
chnl_recv_cb(struct cflayer * layr,struct cfpkt * pkt)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
delete_device(struct chnl_net * dev)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
close_work(struct work_struct * work)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
chnl_hold(struct cflayer * lyr)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
chnl_put(struct cflayer * lyr)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
chnl_flowctrl_cb(struct cflayer * layr,enum caif_ctrlcmd flow,int phyid)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
chnl_net_start_xmit(struct sk_buff * skb,struct net_device * dev)200 static netdev_tx_t chnl_net_start_xmit(struct sk_buff *skb,
201 struct net_device *dev)
202 {
203 struct chnl_net *priv;
204 struct cfpkt *pkt = NULL;
205 int len;
206 int result = -1;
207 /* Get our private data. */
208 priv = netdev_priv(dev);
209
210 if (skb->len > priv->netdev->mtu) {
211 pr_warn("Size of skb exceeded MTU\n");
212 kfree_skb(skb);
213 dev->stats.tx_errors++;
214 return NETDEV_TX_OK;
215 }
216
217 if (!priv->flowenabled) {
218 pr_debug("dropping packets flow off\n");
219 kfree_skb(skb);
220 dev->stats.tx_dropped++;
221 return NETDEV_TX_OK;
222 }
223
224 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
225 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
226
227 /* Store original SKB length. */
228 len = skb->len;
229
230 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
231
232 /* Send the packet down the stack. */
233 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
234 if (result) {
235 dev->stats.tx_dropped++;
236 return NETDEV_TX_OK;
237 }
238
239 /* Update statistics. */
240 dev->stats.tx_packets++;
241 dev->stats.tx_bytes += len;
242
243 return NETDEV_TX_OK;
244 }
245
chnl_net_open(struct net_device * dev)246 static int chnl_net_open(struct net_device *dev)
247 {
248 struct chnl_net *priv = NULL;
249 int result = -1;
250 int llifindex, headroom, tailroom, mtu;
251 struct net_device *lldev;
252 ASSERT_RTNL();
253 priv = netdev_priv(dev);
254 if (!priv) {
255 pr_debug("chnl_net_open: no priv\n");
256 return -ENODEV;
257 }
258
259 if (priv->state != CAIF_CONNECTING) {
260 priv->state = CAIF_CONNECTING;
261 result = caif_connect_client(dev_net(dev), &priv->conn_req,
262 &priv->chnl, &llifindex,
263 &headroom, &tailroom);
264 if (result != 0) {
265 pr_debug("err: "
266 "Unable to register and open device,"
267 " Err:%d\n",
268 result);
269 goto error;
270 }
271
272 lldev = __dev_get_by_index(dev_net(dev), llifindex);
273
274 if (lldev == NULL) {
275 pr_debug("no interface?\n");
276 result = -ENODEV;
277 goto error;
278 }
279
280 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
281 dev->hard_header_len = headroom + lldev->hard_header_len +
282 lldev->needed_tailroom;
283
284 /*
285 * MTU, head-room etc is not know before we have a
286 * CAIF link layer device available. MTU calculation may
287 * override initial RTNL configuration.
288 * MTU is minimum of current mtu, link layer mtu pluss
289 * CAIF head and tail, and PDP GPRS contexts max MTU.
290 */
291 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
292 mtu = min_t(int, GPRS_PDP_MTU, mtu);
293 dev_set_mtu(dev, mtu);
294
295 if (mtu < 100) {
296 pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
297 result = -ENODEV;
298 goto error;
299 }
300 }
301
302 rtnl_unlock(); /* Release RTNL lock during connect wait */
303
304 result = wait_event_interruptible_timeout(priv->netmgmt_wq,
305 priv->state != CAIF_CONNECTING,
306 CONNECT_TIMEOUT);
307
308 rtnl_lock();
309
310 if (result == -ERESTARTSYS) {
311 pr_debug("wait_event_interruptible woken by a signal\n");
312 result = -ERESTARTSYS;
313 goto error;
314 }
315
316 if (result == 0) {
317 pr_debug("connect timeout\n");
318 caif_disconnect_client(dev_net(dev), &priv->chnl);
319 priv->state = CAIF_DISCONNECTED;
320 pr_debug("state disconnected\n");
321 result = -ETIMEDOUT;
322 goto error;
323 }
324
325 if (priv->state != CAIF_CONNECTED) {
326 pr_debug("connect failed\n");
327 result = -ECONNREFUSED;
328 goto error;
329 }
330 pr_debug("CAIF Netdevice connected\n");
331 return 0;
332
333 error:
334 caif_disconnect_client(dev_net(dev), &priv->chnl);
335 priv->state = CAIF_DISCONNECTED;
336 pr_debug("state disconnected\n");
337 return result;
338
339 }
340
chnl_net_stop(struct net_device * dev)341 static int chnl_net_stop(struct net_device *dev)
342 {
343 struct chnl_net *priv;
344
345 ASSERT_RTNL();
346 priv = netdev_priv(dev);
347 priv->state = CAIF_DISCONNECTED;
348 caif_disconnect_client(dev_net(dev), &priv->chnl);
349 return 0;
350 }
351
chnl_net_init(struct net_device * dev)352 static int chnl_net_init(struct net_device *dev)
353 {
354 struct chnl_net *priv;
355 ASSERT_RTNL();
356 priv = netdev_priv(dev);
357 strncpy(priv->name, dev->name, sizeof(priv->name));
358 INIT_LIST_HEAD(&priv->list_field);
359 return 0;
360 }
361
chnl_net_uninit(struct net_device * dev)362 static void chnl_net_uninit(struct net_device *dev)
363 {
364 struct chnl_net *priv;
365 ASSERT_RTNL();
366 priv = netdev_priv(dev);
367 list_del_init(&priv->list_field);
368 }
369
370 static const struct net_device_ops netdev_ops = {
371 .ndo_open = chnl_net_open,
372 .ndo_stop = chnl_net_stop,
373 .ndo_init = chnl_net_init,
374 .ndo_uninit = chnl_net_uninit,
375 .ndo_start_xmit = chnl_net_start_xmit,
376 };
377
chnl_net_destructor(struct net_device * dev)378 static void chnl_net_destructor(struct net_device *dev)
379 {
380 struct chnl_net *priv = netdev_priv(dev);
381 caif_free_client(&priv->chnl);
382 }
383
ipcaif_net_setup(struct net_device * dev)384 static void ipcaif_net_setup(struct net_device *dev)
385 {
386 struct chnl_net *priv;
387 dev->netdev_ops = &netdev_ops;
388 dev->needs_free_netdev = true;
389 dev->priv_destructor = chnl_net_destructor;
390 dev->flags |= IFF_NOARP;
391 dev->flags |= IFF_POINTOPOINT;
392 dev->mtu = GPRS_PDP_MTU;
393 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
394
395 priv = netdev_priv(dev);
396 priv->chnl.receive = chnl_recv_cb;
397 priv->chnl.ctrlcmd = chnl_flowctrl_cb;
398 priv->netdev = dev;
399 priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
400 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
401 priv->conn_req.priority = CAIF_PRIO_LOW;
402 /* Insert illegal value */
403 priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
404 priv->flowenabled = false;
405
406 init_waitqueue_head(&priv->netmgmt_wq);
407 }
408
409
ipcaif_fill_info(struct sk_buff * skb,const struct net_device * dev)410 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
411 {
412 struct chnl_net *priv;
413 u8 loop;
414 priv = netdev_priv(dev);
415 if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
416 priv->conn_req.sockaddr.u.dgm.connection_id) ||
417 nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
418 priv->conn_req.sockaddr.u.dgm.connection_id))
419 goto nla_put_failure;
420 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
421 if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
422 goto nla_put_failure;
423 return 0;
424 nla_put_failure:
425 return -EMSGSIZE;
426
427 }
428
caif_netlink_parms(struct nlattr * data[],struct caif_connect_request * conn_req)429 static void caif_netlink_parms(struct nlattr *data[],
430 struct caif_connect_request *conn_req)
431 {
432 if (!data) {
433 pr_warn("no params data found\n");
434 return;
435 }
436 if (data[IFLA_CAIF_IPV4_CONNID])
437 conn_req->sockaddr.u.dgm.connection_id =
438 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
439 if (data[IFLA_CAIF_IPV6_CONNID])
440 conn_req->sockaddr.u.dgm.connection_id =
441 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
442 if (data[IFLA_CAIF_LOOPBACK]) {
443 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
444 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
445 else
446 conn_req->protocol = CAIFPROTO_DATAGRAM;
447 }
448 }
449
ipcaif_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)450 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
451 struct nlattr *tb[], struct nlattr *data[],
452 struct netlink_ext_ack *extack)
453 {
454 int ret;
455 struct chnl_net *caifdev;
456 ASSERT_RTNL();
457 caifdev = netdev_priv(dev);
458 caif_netlink_parms(data, &caifdev->conn_req);
459
460 ret = register_netdevice(dev);
461 if (ret)
462 pr_warn("device rtml registration failed\n");
463 else
464 list_add(&caifdev->list_field, &chnl_net_list);
465
466 /* Use ifindex as connection id, and use loopback channel default. */
467 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
468 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
469 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
470 }
471 return ret;
472 }
473
ipcaif_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)474 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
475 struct nlattr *data[],
476 struct netlink_ext_ack *extack)
477 {
478 struct chnl_net *caifdev;
479 ASSERT_RTNL();
480 caifdev = netdev_priv(dev);
481 caif_netlink_parms(data, &caifdev->conn_req);
482 netdev_state_change(dev);
483 return 0;
484 }
485
ipcaif_get_size(const struct net_device * dev)486 static size_t ipcaif_get_size(const struct net_device *dev)
487 {
488 return
489 /* IFLA_CAIF_IPV4_CONNID */
490 nla_total_size(4) +
491 /* IFLA_CAIF_IPV6_CONNID */
492 nla_total_size(4) +
493 /* IFLA_CAIF_LOOPBACK */
494 nla_total_size(2) +
495 0;
496 }
497
498 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
499 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 },
500 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 },
501 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 }
502 };
503
504
505 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
506 .kind = "caif",
507 .priv_size = sizeof(struct chnl_net),
508 .setup = ipcaif_net_setup,
509 .maxtype = IFLA_CAIF_MAX,
510 .policy = ipcaif_policy,
511 .newlink = ipcaif_newlink,
512 .changelink = ipcaif_changelink,
513 .get_size = ipcaif_get_size,
514 .fill_info = ipcaif_fill_info,
515
516 };
517
chnl_init_module(void)518 static int __init chnl_init_module(void)
519 {
520 return rtnl_link_register(&ipcaif_link_ops);
521 }
522
chnl_exit_module(void)523 static void __exit chnl_exit_module(void)
524 {
525 struct chnl_net *dev = NULL;
526 struct list_head *list_node;
527 struct list_head *_tmp;
528 rtnl_link_unregister(&ipcaif_link_ops);
529 rtnl_lock();
530 list_for_each_safe(list_node, _tmp, &chnl_net_list) {
531 dev = list_entry(list_node, struct chnl_net, list_field);
532 list_del_init(list_node);
533 delete_device(dev);
534 }
535 rtnl_unlock();
536 }
537
538 module_init(chnl_init_module);
539 module_exit(chnl_exit_module);
540