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 void robust_list_del(struct list_head *delete_node) 57 { 58 struct list_head *list_node; 59 struct list_head *n; 60 ASSERT_RTNL(); 61 list_for_each_safe(list_node, n, &chnl_net_list) { 62 if (list_node == delete_node) { 63 list_del(list_node); 64 return; 65 } 66 } 67 WARN_ON(1); 68 } 69 70 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt) 71 { 72 struct sk_buff *skb; 73 struct chnl_net *priv; 74 int pktlen; 75 const u8 *ip_version; 76 u8 buf; 77 78 priv = container_of(layr, struct chnl_net, chnl); 79 if (!priv) 80 return -EINVAL; 81 82 skb = (struct sk_buff *) cfpkt_tonative(pkt); 83 84 /* Get length of CAIF packet. */ 85 pktlen = skb->len; 86 87 /* Pass some minimum information and 88 * send the packet to the net stack. 89 */ 90 skb->dev = priv->netdev; 91 92 /* check the version of IP */ 93 ip_version = skb_header_pointer(skb, 0, 1, &buf); 94 if (!ip_version) { 95 kfree_skb(skb); 96 return -EINVAL; 97 } 98 99 switch (*ip_version >> 4) { 100 case 4: 101 skb->protocol = htons(ETH_P_IP); 102 break; 103 case 6: 104 skb->protocol = htons(ETH_P_IPV6); 105 break; 106 default: 107 kfree_skb(skb); 108 priv->netdev->stats.rx_errors++; 109 return -EINVAL; 110 } 111 112 /* If we change the header in loop mode, the checksum is corrupted. */ 113 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 114 skb->ip_summed = CHECKSUM_UNNECESSARY; 115 else 116 skb->ip_summed = CHECKSUM_NONE; 117 118 netif_rx_any_context(skb); 119 120 /* Update statistics. */ 121 priv->netdev->stats.rx_packets++; 122 priv->netdev->stats.rx_bytes += pktlen; 123 124 return 0; 125 } 126 127 static int delete_device(struct chnl_net *dev) 128 { 129 ASSERT_RTNL(); 130 if (dev->netdev) 131 unregister_netdevice(dev->netdev); 132 return 0; 133 } 134 135 static void close_work(struct work_struct *work) 136 { 137 struct chnl_net *dev = NULL; 138 struct list_head *list_node; 139 struct list_head *_tmp; 140 141 rtnl_lock(); 142 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 143 dev = list_entry(list_node, struct chnl_net, list_field); 144 if (dev->state == CAIF_SHUTDOWN) 145 dev_close(dev->netdev); 146 } 147 rtnl_unlock(); 148 } 149 static DECLARE_WORK(close_worker, close_work); 150 151 static void chnl_hold(struct cflayer *lyr) 152 { 153 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); 154 dev_hold(priv->netdev); 155 } 156 157 static void chnl_put(struct cflayer *lyr) 158 { 159 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); 160 dev_put(priv->netdev); 161 } 162 163 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow, 164 int phyid) 165 { 166 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl); 167 pr_debug("NET flowctrl func called flow: %s\n", 168 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" : 169 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" : 170 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" : 171 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" : 172 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" : 173 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? 174 "REMOTE_SHUTDOWN" : "UNKNOWN CTRL COMMAND"); 175 176 177 178 switch (flow) { 179 case CAIF_CTRLCMD_FLOW_OFF_IND: 180 priv->flowenabled = false; 181 netif_stop_queue(priv->netdev); 182 break; 183 case CAIF_CTRLCMD_DEINIT_RSP: 184 priv->state = CAIF_DISCONNECTED; 185 break; 186 case CAIF_CTRLCMD_INIT_FAIL_RSP: 187 priv->state = CAIF_DISCONNECTED; 188 wake_up_interruptible(&priv->netmgmt_wq); 189 break; 190 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 191 priv->state = CAIF_SHUTDOWN; 192 netif_tx_disable(priv->netdev); 193 schedule_work(&close_worker); 194 break; 195 case CAIF_CTRLCMD_FLOW_ON_IND: 196 priv->flowenabled = true; 197 netif_wake_queue(priv->netdev); 198 break; 199 case CAIF_CTRLCMD_INIT_RSP: 200 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put); 201 priv->state = CAIF_CONNECTED; 202 priv->flowenabled = true; 203 netif_wake_queue(priv->netdev); 204 wake_up_interruptible(&priv->netmgmt_wq); 205 break; 206 default: 207 break; 208 } 209 } 210 211 static netdev_tx_t chnl_net_start_xmit(struct sk_buff *skb, 212 struct net_device *dev) 213 { 214 struct chnl_net *priv; 215 struct cfpkt *pkt = NULL; 216 int len; 217 int result = -1; 218 /* Get our private data. */ 219 priv = netdev_priv(dev); 220 221 if (skb->len > priv->netdev->mtu) { 222 pr_warn("Size of skb exceeded MTU\n"); 223 kfree_skb(skb); 224 dev->stats.tx_errors++; 225 return NETDEV_TX_OK; 226 } 227 228 if (!priv->flowenabled) { 229 pr_debug("dropping packets flow off\n"); 230 kfree_skb(skb); 231 dev->stats.tx_dropped++; 232 return NETDEV_TX_OK; 233 } 234 235 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 236 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); 237 238 /* Store original SKB length. */ 239 len = skb->len; 240 241 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb); 242 243 /* Send the packet down the stack. */ 244 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt); 245 if (result) { 246 dev->stats.tx_dropped++; 247 return NETDEV_TX_OK; 248 } 249 250 /* Update statistics. */ 251 dev->stats.tx_packets++; 252 dev->stats.tx_bytes += len; 253 254 return NETDEV_TX_OK; 255 } 256 257 static int chnl_net_open(struct net_device *dev) 258 { 259 struct chnl_net *priv = NULL; 260 int result = -1; 261 int llifindex, headroom, tailroom, mtu; 262 struct net_device *lldev; 263 ASSERT_RTNL(); 264 priv = netdev_priv(dev); 265 if (!priv) { 266 pr_debug("chnl_net_open: no priv\n"); 267 return -ENODEV; 268 } 269 270 if (priv->state != CAIF_CONNECTING) { 271 priv->state = CAIF_CONNECTING; 272 result = caif_connect_client(dev_net(dev), &priv->conn_req, 273 &priv->chnl, &llifindex, 274 &headroom, &tailroom); 275 if (result != 0) { 276 pr_debug("err: " 277 "Unable to register and open device," 278 " Err:%d\n", 279 result); 280 goto error; 281 } 282 283 lldev = __dev_get_by_index(dev_net(dev), llifindex); 284 285 if (lldev == NULL) { 286 pr_debug("no interface?\n"); 287 result = -ENODEV; 288 goto error; 289 } 290 291 dev->needed_tailroom = tailroom + lldev->needed_tailroom; 292 dev->hard_header_len = headroom + lldev->hard_header_len + 293 lldev->needed_tailroom; 294 295 /* 296 * MTU, head-room etc is not know before we have a 297 * CAIF link layer device available. MTU calculation may 298 * override initial RTNL configuration. 299 * MTU is minimum of current mtu, link layer mtu pluss 300 * CAIF head and tail, and PDP GPRS contexts max MTU. 301 */ 302 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom)); 303 mtu = min_t(int, GPRS_PDP_MTU, mtu); 304 dev_set_mtu(dev, mtu); 305 306 if (mtu < 100) { 307 pr_warn("CAIF Interface MTU too small (%d)\n", mtu); 308 result = -ENODEV; 309 goto error; 310 } 311 } 312 313 rtnl_unlock(); /* Release RTNL lock during connect wait */ 314 315 result = wait_event_interruptible_timeout(priv->netmgmt_wq, 316 priv->state != CAIF_CONNECTING, 317 CONNECT_TIMEOUT); 318 319 rtnl_lock(); 320 321 if (result == -ERESTARTSYS) { 322 pr_debug("wait_event_interruptible woken by a signal\n"); 323 result = -ERESTARTSYS; 324 goto error; 325 } 326 327 if (result == 0) { 328 pr_debug("connect timeout\n"); 329 caif_disconnect_client(dev_net(dev), &priv->chnl); 330 priv->state = CAIF_DISCONNECTED; 331 pr_debug("state disconnected\n"); 332 result = -ETIMEDOUT; 333 goto error; 334 } 335 336 if (priv->state != CAIF_CONNECTED) { 337 pr_debug("connect failed\n"); 338 result = -ECONNREFUSED; 339 goto error; 340 } 341 pr_debug("CAIF Netdevice connected\n"); 342 return 0; 343 344 error: 345 caif_disconnect_client(dev_net(dev), &priv->chnl); 346 priv->state = CAIF_DISCONNECTED; 347 pr_debug("state disconnected\n"); 348 return result; 349 350 } 351 352 static int chnl_net_stop(struct net_device *dev) 353 { 354 struct chnl_net *priv; 355 356 ASSERT_RTNL(); 357 priv = netdev_priv(dev); 358 priv->state = CAIF_DISCONNECTED; 359 caif_disconnect_client(dev_net(dev), &priv->chnl); 360 return 0; 361 } 362 363 static int chnl_net_init(struct net_device *dev) 364 { 365 struct chnl_net *priv; 366 ASSERT_RTNL(); 367 priv = netdev_priv(dev); 368 strncpy(priv->name, dev->name, sizeof(priv->name)); 369 return 0; 370 } 371 372 static void chnl_net_uninit(struct net_device *dev) 373 { 374 struct chnl_net *priv; 375 ASSERT_RTNL(); 376 priv = netdev_priv(dev); 377 robust_list_del(&priv->list_field); 378 } 379 380 static const struct net_device_ops netdev_ops = { 381 .ndo_open = chnl_net_open, 382 .ndo_stop = chnl_net_stop, 383 .ndo_init = chnl_net_init, 384 .ndo_uninit = chnl_net_uninit, 385 .ndo_start_xmit = chnl_net_start_xmit, 386 }; 387 388 static void chnl_net_destructor(struct net_device *dev) 389 { 390 struct chnl_net *priv = netdev_priv(dev); 391 caif_free_client(&priv->chnl); 392 } 393 394 static void ipcaif_net_setup(struct net_device *dev) 395 { 396 struct chnl_net *priv; 397 dev->netdev_ops = &netdev_ops; 398 dev->needs_free_netdev = true; 399 dev->priv_destructor = chnl_net_destructor; 400 dev->flags |= IFF_NOARP; 401 dev->flags |= IFF_POINTOPOINT; 402 dev->mtu = GPRS_PDP_MTU; 403 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN; 404 405 priv = netdev_priv(dev); 406 priv->chnl.receive = chnl_recv_cb; 407 priv->chnl.ctrlcmd = chnl_flowctrl_cb; 408 priv->netdev = dev; 409 priv->conn_req.protocol = CAIFPROTO_DATAGRAM; 410 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW; 411 priv->conn_req.priority = CAIF_PRIO_LOW; 412 /* Insert illegal value */ 413 priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID; 414 priv->flowenabled = false; 415 416 init_waitqueue_head(&priv->netmgmt_wq); 417 } 418 419 420 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev) 421 { 422 struct chnl_net *priv; 423 u8 loop; 424 priv = netdev_priv(dev); 425 if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID, 426 priv->conn_req.sockaddr.u.dgm.connection_id) || 427 nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID, 428 priv->conn_req.sockaddr.u.dgm.connection_id)) 429 goto nla_put_failure; 430 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; 431 if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop)) 432 goto nla_put_failure; 433 return 0; 434 nla_put_failure: 435 return -EMSGSIZE; 436 437 } 438 439 static void caif_netlink_parms(struct nlattr *data[], 440 struct caif_connect_request *conn_req) 441 { 442 if (!data) { 443 pr_warn("no params data found\n"); 444 return; 445 } 446 if (data[IFLA_CAIF_IPV4_CONNID]) 447 conn_req->sockaddr.u.dgm.connection_id = 448 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]); 449 if (data[IFLA_CAIF_IPV6_CONNID]) 450 conn_req->sockaddr.u.dgm.connection_id = 451 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]); 452 if (data[IFLA_CAIF_LOOPBACK]) { 453 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK])) 454 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP; 455 else 456 conn_req->protocol = CAIFPROTO_DATAGRAM; 457 } 458 } 459 460 static int ipcaif_newlink(struct net *src_net, struct net_device *dev, 461 struct nlattr *tb[], struct nlattr *data[], 462 struct netlink_ext_ack *extack) 463 { 464 int ret; 465 struct chnl_net *caifdev; 466 ASSERT_RTNL(); 467 caifdev = netdev_priv(dev); 468 caif_netlink_parms(data, &caifdev->conn_req); 469 470 ret = register_netdevice(dev); 471 if (ret) 472 pr_warn("device rtml registration failed\n"); 473 else 474 list_add(&caifdev->list_field, &chnl_net_list); 475 476 /* Use ifindex as connection id, and use loopback channel default. */ 477 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) { 478 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex; 479 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP; 480 } 481 return ret; 482 } 483 484 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], 485 struct nlattr *data[], 486 struct netlink_ext_ack *extack) 487 { 488 struct chnl_net *caifdev; 489 ASSERT_RTNL(); 490 caifdev = netdev_priv(dev); 491 caif_netlink_parms(data, &caifdev->conn_req); 492 netdev_state_change(dev); 493 return 0; 494 } 495 496 static size_t ipcaif_get_size(const struct net_device *dev) 497 { 498 return 499 /* IFLA_CAIF_IPV4_CONNID */ 500 nla_total_size(4) + 501 /* IFLA_CAIF_IPV6_CONNID */ 502 nla_total_size(4) + 503 /* IFLA_CAIF_LOOPBACK */ 504 nla_total_size(2) + 505 0; 506 } 507 508 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { 509 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, 510 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, 511 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } 512 }; 513 514 515 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { 516 .kind = "caif", 517 .priv_size = sizeof(struct chnl_net), 518 .setup = ipcaif_net_setup, 519 .maxtype = IFLA_CAIF_MAX, 520 .policy = ipcaif_policy, 521 .newlink = ipcaif_newlink, 522 .changelink = ipcaif_changelink, 523 .get_size = ipcaif_get_size, 524 .fill_info = ipcaif_fill_info, 525 526 }; 527 528 static int __init chnl_init_module(void) 529 { 530 return rtnl_link_register(&ipcaif_link_ops); 531 } 532 533 static void __exit chnl_exit_module(void) 534 { 535 struct chnl_net *dev = NULL; 536 struct list_head *list_node; 537 struct list_head *_tmp; 538 rtnl_link_unregister(&ipcaif_link_ops); 539 rtnl_lock(); 540 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 541 dev = list_entry(list_node, struct chnl_net, list_field); 542 list_del(list_node); 543 delete_device(dev); 544 } 545 rtnl_unlock(); 546 } 547 548 module_init(chnl_init_module); 549 module_exit(chnl_exit_module); 550