Merge branch '6.2/scsi-queue' into 6.2/scsi-fixes
[linux-2.6-microblaze.git] / net / caif / chnl_net.c
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
510 static int __init chnl_init_module(void)
511 {
512         return rtnl_link_register(&ipcaif_link_ops);
513 }
514
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);