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 if (in_interrupt()) 119 netif_rx(skb); 120 else 121 netif_rx_ni(skb); 122 123 /* Update statistics. */ 124 priv->netdev->stats.rx_packets++; 125 priv->netdev->stats.rx_bytes += pktlen; 126 127 return 0; 128 } 129 130 static int delete_device(struct chnl_net *dev) 131 { 132 ASSERT_RTNL(); 133 if (dev->netdev) 134 unregister_netdevice(dev->netdev); 135 return 0; 136 } 137 138 static void close_work(struct work_struct *work) 139 { 140 struct chnl_net *dev = NULL; 141 struct list_head *list_node; 142 struct list_head *_tmp; 143 144 rtnl_lock(); 145 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 146 dev = list_entry(list_node, struct chnl_net, list_field); 147 if (dev->state == CAIF_SHUTDOWN) 148 dev_close(dev->netdev); 149 } 150 rtnl_unlock(); 151 } 152 static DECLARE_WORK(close_worker, close_work); 153 154 static void chnl_hold(struct cflayer *lyr) 155 { 156 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); 157 dev_hold(priv->netdev); 158 } 159 160 static void chnl_put(struct cflayer *lyr) 161 { 162 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); 163 dev_put(priv->netdev); 164 } 165 166 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow, 167 int phyid) 168 { 169 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl); 170 pr_debug("NET flowctrl func called flow: %s\n", 171 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" : 172 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" : 173 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" : 174 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" : 175 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" : 176 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? 177 "REMOTE_SHUTDOWN" : "UNKNOWN CTRL COMMAND"); 178 179 180 181 switch (flow) { 182 case CAIF_CTRLCMD_FLOW_OFF_IND: 183 priv->flowenabled = false; 184 netif_stop_queue(priv->netdev); 185 break; 186 case CAIF_CTRLCMD_DEINIT_RSP: 187 priv->state = CAIF_DISCONNECTED; 188 break; 189 case CAIF_CTRLCMD_INIT_FAIL_RSP: 190 priv->state = CAIF_DISCONNECTED; 191 wake_up_interruptible(&priv->netmgmt_wq); 192 break; 193 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 194 priv->state = CAIF_SHUTDOWN; 195 netif_tx_disable(priv->netdev); 196 schedule_work(&close_worker); 197 break; 198 case CAIF_CTRLCMD_FLOW_ON_IND: 199 priv->flowenabled = true; 200 netif_wake_queue(priv->netdev); 201 break; 202 case CAIF_CTRLCMD_INIT_RSP: 203 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put); 204 priv->state = CAIF_CONNECTED; 205 priv->flowenabled = true; 206 netif_wake_queue(priv->netdev); 207 wake_up_interruptible(&priv->netmgmt_wq); 208 break; 209 default: 210 break; 211 } 212 } 213 214 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev) 215 { 216 struct chnl_net *priv; 217 struct cfpkt *pkt = NULL; 218 int len; 219 int result = -1; 220 /* Get our private data. */ 221 priv = netdev_priv(dev); 222 223 if (skb->len > priv->netdev->mtu) { 224 pr_warn("Size of skb exceeded MTU\n"); 225 kfree_skb(skb); 226 dev->stats.tx_errors++; 227 return NETDEV_TX_OK; 228 } 229 230 if (!priv->flowenabled) { 231 pr_debug("dropping packets flow off\n"); 232 kfree_skb(skb); 233 dev->stats.tx_dropped++; 234 return NETDEV_TX_OK; 235 } 236 237 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 238 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); 239 240 /* Store original SKB length. */ 241 len = skb->len; 242 243 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb); 244 245 /* Send the packet down the stack. */ 246 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt); 247 if (result) { 248 dev->stats.tx_dropped++; 249 return NETDEV_TX_OK; 250 } 251 252 /* Update statistics. */ 253 dev->stats.tx_packets++; 254 dev->stats.tx_bytes += len; 255 256 return NETDEV_TX_OK; 257 } 258 259 static int chnl_net_open(struct net_device *dev) 260 { 261 struct chnl_net *priv = NULL; 262 int result = -1; 263 int llifindex, headroom, tailroom, mtu; 264 struct net_device *lldev; 265 ASSERT_RTNL(); 266 priv = netdev_priv(dev); 267 if (!priv) { 268 pr_debug("chnl_net_open: no priv\n"); 269 return -ENODEV; 270 } 271 272 if (priv->state != CAIF_CONNECTING) { 273 priv->state = CAIF_CONNECTING; 274 result = caif_connect_client(dev_net(dev), &priv->conn_req, 275 &priv->chnl, &llifindex, 276 &headroom, &tailroom); 277 if (result != 0) { 278 pr_debug("err: " 279 "Unable to register and open device," 280 " Err:%d\n", 281 result); 282 goto error; 283 } 284 285 lldev = __dev_get_by_index(dev_net(dev), llifindex); 286 287 if (lldev == NULL) { 288 pr_debug("no interface?\n"); 289 result = -ENODEV; 290 goto error; 291 } 292 293 dev->needed_tailroom = tailroom + lldev->needed_tailroom; 294 dev->hard_header_len = headroom + lldev->hard_header_len + 295 lldev->needed_tailroom; 296 297 /* 298 * MTU, head-room etc is not know before we have a 299 * CAIF link layer device available. MTU calculation may 300 * override initial RTNL configuration. 301 * MTU is minimum of current mtu, link layer mtu pluss 302 * CAIF head and tail, and PDP GPRS contexts max MTU. 303 */ 304 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom)); 305 mtu = min_t(int, GPRS_PDP_MTU, mtu); 306 dev_set_mtu(dev, mtu); 307 308 if (mtu < 100) { 309 pr_warn("CAIF Interface MTU too small (%d)\n", mtu); 310 result = -ENODEV; 311 goto error; 312 } 313 } 314 315 rtnl_unlock(); /* Release RTNL lock during connect wait */ 316 317 result = wait_event_interruptible_timeout(priv->netmgmt_wq, 318 priv->state != CAIF_CONNECTING, 319 CONNECT_TIMEOUT); 320 321 rtnl_lock(); 322 323 if (result == -ERESTARTSYS) { 324 pr_debug("wait_event_interruptible woken by a signal\n"); 325 result = -ERESTARTSYS; 326 goto error; 327 } 328 329 if (result == 0) { 330 pr_debug("connect timeout\n"); 331 caif_disconnect_client(dev_net(dev), &priv->chnl); 332 priv->state = CAIF_DISCONNECTED; 333 pr_debug("state disconnected\n"); 334 result = -ETIMEDOUT; 335 goto error; 336 } 337 338 if (priv->state != CAIF_CONNECTED) { 339 pr_debug("connect failed\n"); 340 result = -ECONNREFUSED; 341 goto error; 342 } 343 pr_debug("CAIF Netdevice connected\n"); 344 return 0; 345 346 error: 347 caif_disconnect_client(dev_net(dev), &priv->chnl); 348 priv->state = CAIF_DISCONNECTED; 349 pr_debug("state disconnected\n"); 350 return result; 351 352 } 353 354 static int chnl_net_stop(struct net_device *dev) 355 { 356 struct chnl_net *priv; 357 358 ASSERT_RTNL(); 359 priv = netdev_priv(dev); 360 priv->state = CAIF_DISCONNECTED; 361 caif_disconnect_client(dev_net(dev), &priv->chnl); 362 return 0; 363 } 364 365 static int chnl_net_init(struct net_device *dev) 366 { 367 struct chnl_net *priv; 368 ASSERT_RTNL(); 369 priv = netdev_priv(dev); 370 strncpy(priv->name, dev->name, sizeof(priv->name)); 371 return 0; 372 } 373 374 static void chnl_net_uninit(struct net_device *dev) 375 { 376 struct chnl_net *priv; 377 ASSERT_RTNL(); 378 priv = netdev_priv(dev); 379 robust_list_del(&priv->list_field); 380 } 381 382 static const struct net_device_ops netdev_ops = { 383 .ndo_open = chnl_net_open, 384 .ndo_stop = chnl_net_stop, 385 .ndo_init = chnl_net_init, 386 .ndo_uninit = chnl_net_uninit, 387 .ndo_start_xmit = chnl_net_start_xmit, 388 }; 389 390 static void chnl_net_destructor(struct net_device *dev) 391 { 392 struct chnl_net *priv = netdev_priv(dev); 393 caif_free_client(&priv->chnl); 394 } 395 396 static void ipcaif_net_setup(struct net_device *dev) 397 { 398 struct chnl_net *priv; 399 dev->netdev_ops = &netdev_ops; 400 dev->needs_free_netdev = true; 401 dev->priv_destructor = chnl_net_destructor; 402 dev->flags |= IFF_NOARP; 403 dev->flags |= IFF_POINTOPOINT; 404 dev->mtu = GPRS_PDP_MTU; 405 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN; 406 407 priv = netdev_priv(dev); 408 priv->chnl.receive = chnl_recv_cb; 409 priv->chnl.ctrlcmd = chnl_flowctrl_cb; 410 priv->netdev = dev; 411 priv->conn_req.protocol = CAIFPROTO_DATAGRAM; 412 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW; 413 priv->conn_req.priority = CAIF_PRIO_LOW; 414 /* Insert illegal value */ 415 priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID; 416 priv->flowenabled = false; 417 418 init_waitqueue_head(&priv->netmgmt_wq); 419 } 420 421 422 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev) 423 { 424 struct chnl_net *priv; 425 u8 loop; 426 priv = netdev_priv(dev); 427 if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID, 428 priv->conn_req.sockaddr.u.dgm.connection_id) || 429 nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID, 430 priv->conn_req.sockaddr.u.dgm.connection_id)) 431 goto nla_put_failure; 432 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; 433 if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop)) 434 goto nla_put_failure; 435 return 0; 436 nla_put_failure: 437 return -EMSGSIZE; 438 439 } 440 441 static void caif_netlink_parms(struct nlattr *data[], 442 struct caif_connect_request *conn_req) 443 { 444 if (!data) { 445 pr_warn("no params data found\n"); 446 return; 447 } 448 if (data[IFLA_CAIF_IPV4_CONNID]) 449 conn_req->sockaddr.u.dgm.connection_id = 450 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]); 451 if (data[IFLA_CAIF_IPV6_CONNID]) 452 conn_req->sockaddr.u.dgm.connection_id = 453 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]); 454 if (data[IFLA_CAIF_LOOPBACK]) { 455 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK])) 456 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP; 457 else 458 conn_req->protocol = CAIFPROTO_DATAGRAM; 459 } 460 } 461 462 static int ipcaif_newlink(struct net *src_net, struct net_device *dev, 463 struct nlattr *tb[], struct nlattr *data[], 464 struct netlink_ext_ack *extack) 465 { 466 int ret; 467 struct chnl_net *caifdev; 468 ASSERT_RTNL(); 469 caifdev = netdev_priv(dev); 470 caif_netlink_parms(data, &caifdev->conn_req); 471 472 ret = register_netdevice(dev); 473 if (ret) 474 pr_warn("device rtml registration failed\n"); 475 else 476 list_add(&caifdev->list_field, &chnl_net_list); 477 478 /* Use ifindex as connection id, and use loopback channel default. */ 479 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) { 480 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex; 481 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP; 482 } 483 return ret; 484 } 485 486 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], 487 struct nlattr *data[], 488 struct netlink_ext_ack *extack) 489 { 490 struct chnl_net *caifdev; 491 ASSERT_RTNL(); 492 caifdev = netdev_priv(dev); 493 caif_netlink_parms(data, &caifdev->conn_req); 494 netdev_state_change(dev); 495 return 0; 496 } 497 498 static size_t ipcaif_get_size(const struct net_device *dev) 499 { 500 return 501 /* IFLA_CAIF_IPV4_CONNID */ 502 nla_total_size(4) + 503 /* IFLA_CAIF_IPV6_CONNID */ 504 nla_total_size(4) + 505 /* IFLA_CAIF_LOOPBACK */ 506 nla_total_size(2) + 507 0; 508 } 509 510 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { 511 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, 512 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, 513 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } 514 }; 515 516 517 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { 518 .kind = "caif", 519 .priv_size = sizeof(struct chnl_net), 520 .setup = ipcaif_net_setup, 521 .maxtype = IFLA_CAIF_MAX, 522 .policy = ipcaif_policy, 523 .newlink = ipcaif_newlink, 524 .changelink = ipcaif_changelink, 525 .get_size = ipcaif_get_size, 526 .fill_info = ipcaif_fill_info, 527 528 }; 529 530 static int __init chnl_init_module(void) 531 { 532 return rtnl_link_register(&ipcaif_link_ops); 533 } 534 535 static void __exit chnl_exit_module(void) 536 { 537 struct chnl_net *dev = NULL; 538 struct list_head *list_node; 539 struct list_head *_tmp; 540 rtnl_link_unregister(&ipcaif_link_ops); 541 rtnl_lock(); 542 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 543 dev = list_entry(list_node, struct chnl_net, list_field); 544 list_del(list_node); 545 delete_device(dev); 546 } 547 rtnl_unlock(); 548 } 549 550 module_init(chnl_init_module); 551 module_exit(chnl_exit_module); 552