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 caif_disconnect_client(dev_net(dev), &priv->chnl); 314 priv->state = CAIF_DISCONNECTED; 315 pr_debug("state disconnected\n"); 316 result = -ETIMEDOUT; 317 goto error; 318 } 319 320 if (priv->state != CAIF_CONNECTED) { 321 pr_debug("connect failed\n"); 322 result = -ECONNREFUSED; 323 goto error; 324 } 325 pr_debug("CAIF Netdevice connected\n"); 326 return 0; 327 328 error: 329 caif_disconnect_client(dev_net(dev), &priv->chnl); 330 priv->state = CAIF_DISCONNECTED; 331 pr_debug("state disconnected\n"); 332 return result; 333 334 } 335 336 static int chnl_net_stop(struct net_device *dev) 337 { 338 struct chnl_net *priv; 339 340 ASSERT_RTNL(); 341 priv = netdev_priv(dev); 342 priv->state = CAIF_DISCONNECTED; 343 caif_disconnect_client(dev_net(dev), &priv->chnl); 344 return 0; 345 } 346 347 static int chnl_net_init(struct net_device *dev) 348 { 349 struct chnl_net *priv; 350 ASSERT_RTNL(); 351 priv = netdev_priv(dev); 352 strncpy(priv->name, dev->name, sizeof(priv->name)); 353 INIT_LIST_HEAD(&priv->list_field); 354 return 0; 355 } 356 357 static void chnl_net_uninit(struct net_device *dev) 358 { 359 struct chnl_net *priv; 360 ASSERT_RTNL(); 361 priv = netdev_priv(dev); 362 list_del_init(&priv->list_field); 363 } 364 365 static const struct net_device_ops netdev_ops = { 366 .ndo_open = chnl_net_open, 367 .ndo_stop = chnl_net_stop, 368 .ndo_init = chnl_net_init, 369 .ndo_uninit = chnl_net_uninit, 370 .ndo_start_xmit = chnl_net_start_xmit, 371 }; 372 373 static void chnl_net_destructor(struct net_device *dev) 374 { 375 struct chnl_net *priv = netdev_priv(dev); 376 caif_free_client(&priv->chnl); 377 } 378 379 static void ipcaif_net_setup(struct net_device *dev) 380 { 381 struct chnl_net *priv; 382 dev->netdev_ops = &netdev_ops; 383 dev->needs_free_netdev = true; 384 dev->priv_destructor = chnl_net_destructor; 385 dev->flags |= IFF_NOARP; 386 dev->flags |= IFF_POINTOPOINT; 387 dev->mtu = GPRS_PDP_MTU; 388 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN; 389 390 priv = netdev_priv(dev); 391 priv->chnl.receive = chnl_recv_cb; 392 priv->chnl.ctrlcmd = chnl_flowctrl_cb; 393 priv->netdev = dev; 394 priv->conn_req.protocol = CAIFPROTO_DATAGRAM; 395 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW; 396 priv->conn_req.priority = CAIF_PRIO_LOW; 397 /* Insert illegal value */ 398 priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID; 399 priv->flowenabled = false; 400 401 init_waitqueue_head(&priv->netmgmt_wq); 402 } 403 404 405 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev) 406 { 407 struct chnl_net *priv; 408 u8 loop; 409 priv = netdev_priv(dev); 410 if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID, 411 priv->conn_req.sockaddr.u.dgm.connection_id) || 412 nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID, 413 priv->conn_req.sockaddr.u.dgm.connection_id)) 414 goto nla_put_failure; 415 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; 416 if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop)) 417 goto nla_put_failure; 418 return 0; 419 nla_put_failure: 420 return -EMSGSIZE; 421 422 } 423 424 static void caif_netlink_parms(struct nlattr *data[], 425 struct caif_connect_request *conn_req) 426 { 427 if (!data) { 428 pr_warn("no params data found\n"); 429 return; 430 } 431 if (data[IFLA_CAIF_IPV4_CONNID]) 432 conn_req->sockaddr.u.dgm.connection_id = 433 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]); 434 if (data[IFLA_CAIF_IPV6_CONNID]) 435 conn_req->sockaddr.u.dgm.connection_id = 436 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]); 437 if (data[IFLA_CAIF_LOOPBACK]) { 438 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK])) 439 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP; 440 else 441 conn_req->protocol = CAIFPROTO_DATAGRAM; 442 } 443 } 444 445 static int ipcaif_newlink(struct net *src_net, struct net_device *dev, 446 struct nlattr *tb[], struct nlattr *data[], 447 struct netlink_ext_ack *extack) 448 { 449 int ret; 450 struct chnl_net *caifdev; 451 ASSERT_RTNL(); 452 caifdev = netdev_priv(dev); 453 caif_netlink_parms(data, &caifdev->conn_req); 454 455 ret = register_netdevice(dev); 456 if (ret) 457 pr_warn("device rtml registration failed\n"); 458 else 459 list_add(&caifdev->list_field, &chnl_net_list); 460 461 /* Use ifindex as connection id, and use loopback channel default. */ 462 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) { 463 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex; 464 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP; 465 } 466 return ret; 467 } 468 469 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], 470 struct nlattr *data[], 471 struct netlink_ext_ack *extack) 472 { 473 struct chnl_net *caifdev; 474 ASSERT_RTNL(); 475 caifdev = netdev_priv(dev); 476 caif_netlink_parms(data, &caifdev->conn_req); 477 netdev_state_change(dev); 478 return 0; 479 } 480 481 static size_t ipcaif_get_size(const struct net_device *dev) 482 { 483 return 484 /* IFLA_CAIF_IPV4_CONNID */ 485 nla_total_size(4) + 486 /* IFLA_CAIF_IPV6_CONNID */ 487 nla_total_size(4) + 488 /* IFLA_CAIF_LOOPBACK */ 489 nla_total_size(2) + 490 0; 491 } 492 493 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { 494 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, 495 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, 496 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } 497 }; 498 499 500 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { 501 .kind = "caif", 502 .priv_size = sizeof(struct chnl_net), 503 .setup = ipcaif_net_setup, 504 .maxtype = IFLA_CAIF_MAX, 505 .policy = ipcaif_policy, 506 .newlink = ipcaif_newlink, 507 .changelink = ipcaif_changelink, 508 .get_size = ipcaif_get_size, 509 .fill_info = ipcaif_fill_info, 510 511 }; 512 513 static int __init chnl_init_module(void) 514 { 515 return rtnl_link_register(&ipcaif_link_ops); 516 } 517 518 static void __exit chnl_exit_module(void) 519 { 520 struct chnl_net *dev = NULL; 521 struct list_head *list_node; 522 struct list_head *_tmp; 523 rtnl_link_unregister(&ipcaif_link_ops); 524 rtnl_lock(); 525 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 526 dev = list_entry(list_node, struct chnl_net, list_field); 527 list_del_init(list_node); 528 delete_device(dev); 529 } 530 rtnl_unlock(); 531 } 532 533 module_init(chnl_init_module); 534 module_exit(chnl_exit_module); 535