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