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