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