1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) ST-Ericsson AB 2010
4 * Authors: Sjur Brendeland
8 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/netdevice.h>
14 #include <linux/if_ether.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>
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
31 /*This list is protected by the rtnl lock. */
32 static LIST_HEAD(chnl_net_list);
34 MODULE_DESCRIPTION("ST-Ericsson CAIF modem protocol GPRS network device");
35 MODULE_LICENSE("GPL");
36 MODULE_ALIAS_RTNL_LINK("caif");
47 struct caif_connect_request conn_req;
48 struct list_head list_field;
49 struct net_device *netdev;
51 wait_queue_head_t netmgmt_wq;
52 /* Flow status to remember and control the transmission. */
54 enum caif_states state;
57 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
60 struct chnl_net *priv;
65 priv = container_of(layr, struct chnl_net, chnl);
67 skb = (struct sk_buff *) cfpkt_tonative(pkt);
69 /* Get length of CAIF packet. */
72 /* Pass some minimum information and
73 * send the packet to the net stack.
75 skb->dev = priv->netdev;
77 /* check the version of IP */
78 ip_version = skb_header_pointer(skb, 0, 1, &buf);
84 switch (*ip_version >> 4) {
86 skb->protocol = htons(ETH_P_IP);
89 skb->protocol = htons(ETH_P_IPV6);
93 priv->netdev->stats.rx_errors++;
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;
101 skb->ip_summed = CHECKSUM_NONE;
105 /* Update statistics. */
106 priv->netdev->stats.rx_packets++;
107 priv->netdev->stats.rx_bytes += pktlen;
112 static int delete_device(struct chnl_net *dev)
116 unregister_netdevice(dev->netdev);
120 static void close_work(struct work_struct *work)
122 struct chnl_net *dev = NULL;
123 struct list_head *list_node;
124 struct list_head *_tmp;
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);
134 static DECLARE_WORK(close_worker, close_work);
136 static void chnl_hold(struct cflayer *lyr)
138 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
139 dev_hold(priv->netdev);
142 static void chnl_put(struct cflayer *lyr)
144 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
145 dev_put(priv->netdev);
148 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
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");
164 case CAIF_CTRLCMD_FLOW_OFF_IND:
165 priv->flowenabled = false;
166 netif_stop_queue(priv->netdev);
168 case CAIF_CTRLCMD_DEINIT_RSP:
169 priv->state = CAIF_DISCONNECTED;
171 case CAIF_CTRLCMD_INIT_FAIL_RSP:
172 priv->state = CAIF_DISCONNECTED;
173 wake_up_interruptible(&priv->netmgmt_wq);
175 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
176 priv->state = CAIF_SHUTDOWN;
177 netif_tx_disable(priv->netdev);
178 schedule_work(&close_worker);
180 case CAIF_CTRLCMD_FLOW_ON_IND:
181 priv->flowenabled = true;
182 netif_wake_queue(priv->netdev);
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);
196 static netdev_tx_t chnl_net_start_xmit(struct sk_buff *skb,
197 struct net_device *dev)
199 struct chnl_net *priv;
200 struct cfpkt *pkt = NULL;
203 /* Get our private data. */
204 priv = netdev_priv(dev);
206 if (skb->len > priv->netdev->mtu) {
207 pr_warn("Size of skb exceeded MTU\n");
209 dev->stats.tx_errors++;
213 if (!priv->flowenabled) {
214 pr_debug("dropping packets flow off\n");
216 dev->stats.tx_dropped++;
220 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
221 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
223 /* Store original SKB length. */
226 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
228 /* Send the packet down the stack. */
229 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
231 dev->stats.tx_dropped++;
235 /* Update statistics. */
236 dev->stats.tx_packets++;
237 dev->stats.tx_bytes += len;
242 static int chnl_net_open(struct net_device *dev)
244 struct chnl_net *priv = NULL;
246 int llifindex, headroom, tailroom, mtu;
247 struct net_device *lldev;
249 priv = netdev_priv(dev);
251 pr_debug("chnl_net_open: no priv\n");
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);
262 "Unable to register and open device,"
268 lldev = __dev_get_by_index(dev_net(dev), llifindex);
271 pr_debug("no interface?\n");
276 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
277 dev->hard_header_len = headroom + lldev->hard_header_len +
278 lldev->needed_tailroom;
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.
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);
292 pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
298 rtnl_unlock(); /* Release RTNL lock during connect wait */
300 result = wait_event_interruptible_timeout(priv->netmgmt_wq,
301 priv->state != CAIF_CONNECTING,
306 if (result == -ERESTARTSYS) {
307 pr_debug("wait_event_interruptible woken by a signal\n");
308 result = -ERESTARTSYS;
313 pr_debug("connect timeout\n");
318 if (priv->state != CAIF_CONNECTED) {
319 pr_debug("connect failed\n");
320 result = -ECONNREFUSED;
323 pr_debug("CAIF Netdevice connected\n");
327 caif_disconnect_client(dev_net(dev), &priv->chnl);
328 priv->state = CAIF_DISCONNECTED;
329 pr_debug("state disconnected\n");
334 static int chnl_net_stop(struct net_device *dev)
336 struct chnl_net *priv;
339 priv = netdev_priv(dev);
340 priv->state = CAIF_DISCONNECTED;
341 caif_disconnect_client(dev_net(dev), &priv->chnl);
345 static int chnl_net_init(struct net_device *dev)
347 struct chnl_net *priv;
349 priv = netdev_priv(dev);
350 strncpy(priv->name, dev->name, sizeof(priv->name));
351 INIT_LIST_HEAD(&priv->list_field);
355 static void chnl_net_uninit(struct net_device *dev)
357 struct chnl_net *priv;
359 priv = netdev_priv(dev);
360 list_del_init(&priv->list_field);
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,
371 static void chnl_net_destructor(struct net_device *dev)
373 struct chnl_net *priv = netdev_priv(dev);
374 caif_free_client(&priv->chnl);
377 static void ipcaif_net_setup(struct net_device *dev)
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;
388 priv = netdev_priv(dev);
389 priv->chnl.receive = chnl_recv_cb;
390 priv->chnl.ctrlcmd = chnl_flowctrl_cb;
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;
399 init_waitqueue_head(&priv->netmgmt_wq);
403 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
405 struct chnl_net *priv;
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;
422 static void caif_netlink_parms(struct nlattr *data[],
423 struct caif_connect_request *conn_req)
426 pr_warn("no params data found\n");
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;
439 conn_req->protocol = CAIFPROTO_DATAGRAM;
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)
448 struct chnl_net *caifdev;
450 caifdev = netdev_priv(dev);
451 caif_netlink_parms(data, &caifdev->conn_req);
453 ret = register_netdevice(dev);
455 pr_warn("device rtml registration failed\n");
457 list_add(&caifdev->list_field, &chnl_net_list);
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;
467 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
468 struct nlattr *data[],
469 struct netlink_ext_ack *extack)
471 struct chnl_net *caifdev;
473 caifdev = netdev_priv(dev);
474 caif_netlink_parms(data, &caifdev->conn_req);
475 netdev_state_change(dev);
479 static size_t ipcaif_get_size(const struct net_device *dev)
482 /* IFLA_CAIF_IPV4_CONNID */
484 /* IFLA_CAIF_IPV6_CONNID */
486 /* IFLA_CAIF_LOOPBACK */
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 }
498 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
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,
511 static int __init chnl_init_module(void)
513 return rtnl_link_register(&ipcaif_link_ops);
516 static void __exit chnl_exit_module(void)
518 struct chnl_net *dev = NULL;
519 struct list_head *list_node;
520 struct list_head *_tmp;
521 rtnl_link_unregister(&ipcaif_link_ops);
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);
531 module_init(chnl_init_module);
532 module_exit(chnl_exit_module);