1 /* 2 * Copyright (C) ST-Ericsson AB 2010 3 * Authors: Sjur Brendeland 4 * Daniel Martensson 5 * License terms: GNU General Public License (GPL) version 2 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ 9 10 #include <linux/fs.h> 11 #include <linux/hardirq.h> 12 #include <linux/init.h> 13 #include <linux/module.h> 14 #include <linux/netdevice.h> 15 #include <linux/if_ether.h> 16 #include <linux/moduleparam.h> 17 #include <linux/ip.h> 18 #include <linux/sched.h> 19 #include <linux/sockios.h> 20 #include <linux/caif/if_caif.h> 21 #include <net/rtnetlink.h> 22 #include <net/caif/caif_layer.h> 23 #include <net/caif/cfpkt.h> 24 #include <net/caif/caif_dev.h> 25 26 /* GPRS PDP connection has MTU to 1500 */ 27 #define GPRS_PDP_MTU 1500 28 /* 5 sec. connect timeout */ 29 #define CONNECT_TIMEOUT (5 * HZ) 30 #define CAIF_NET_DEFAULT_QUEUE_LEN 500 31 #define UNDEF_CONNID 0xffffffff 32 33 /*This list is protected by the rtnl lock. */ 34 static LIST_HEAD(chnl_net_list); 35 36 MODULE_LICENSE("GPL"); 37 MODULE_ALIAS_RTNL_LINK("caif"); 38 39 enum caif_states { 40 CAIF_CONNECTED = 1, 41 CAIF_CONNECTING, 42 CAIF_DISCONNECTED, 43 CAIF_SHUTDOWN 44 }; 45 46 struct chnl_net { 47 struct cflayer chnl; 48 struct net_device_stats stats; 49 struct caif_connect_request conn_req; 50 struct list_head list_field; 51 struct net_device *netdev; 52 char name[256]; 53 wait_queue_head_t netmgmt_wq; 54 /* Flow status to remember and control the transmission. */ 55 bool flowenabled; 56 enum caif_states state; 57 }; 58 59 static void robust_list_del(struct list_head *delete_node) 60 { 61 struct list_head *list_node; 62 struct list_head *n; 63 ASSERT_RTNL(); 64 list_for_each_safe(list_node, n, &chnl_net_list) { 65 if (list_node == delete_node) { 66 list_del(list_node); 67 return; 68 } 69 } 70 WARN_ON(1); 71 } 72 73 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt) 74 { 75 struct sk_buff *skb; 76 struct chnl_net *priv; 77 int pktlen; 78 const u8 *ip_version; 79 u8 buf; 80 81 priv = container_of(layr, struct chnl_net, chnl); 82 if (!priv) 83 return -EINVAL; 84 85 skb = (struct sk_buff *) cfpkt_tonative(pkt); 86 87 /* Get length of CAIF packet. */ 88 pktlen = skb->len; 89 90 /* Pass some minimum information and 91 * send the packet to the net stack. 92 */ 93 skb->dev = priv->netdev; 94 95 /* check the version of IP */ 96 ip_version = skb_header_pointer(skb, 0, 1, &buf); 97 if (!ip_version) { 98 kfree_skb(skb); 99 return -EINVAL; 100 } 101 102 switch (*ip_version >> 4) { 103 case 4: 104 skb->protocol = htons(ETH_P_IP); 105 break; 106 case 6: 107 skb->protocol = htons(ETH_P_IPV6); 108 break; 109 default: 110 kfree_skb(skb); 111 priv->netdev->stats.rx_errors++; 112 return -EINVAL; 113 } 114 115 /* If we change the header in loop mode, the checksum is corrupted. */ 116 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 117 skb->ip_summed = CHECKSUM_UNNECESSARY; 118 else 119 skb->ip_summed = CHECKSUM_NONE; 120 121 if (in_interrupt()) 122 netif_rx(skb); 123 else 124 netif_rx_ni(skb); 125 126 /* Update statistics. */ 127 priv->netdev->stats.rx_packets++; 128 priv->netdev->stats.rx_bytes += pktlen; 129 130 return 0; 131 } 132 133 static int delete_device(struct chnl_net *dev) 134 { 135 ASSERT_RTNL(); 136 if (dev->netdev) 137 unregister_netdevice(dev->netdev); 138 return 0; 139 } 140 141 static void close_work(struct work_struct *work) 142 { 143 struct chnl_net *dev = NULL; 144 struct list_head *list_node; 145 struct list_head *_tmp; 146 147 rtnl_lock(); 148 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 149 dev = list_entry(list_node, struct chnl_net, list_field); 150 if (dev->state == CAIF_SHUTDOWN) 151 dev_close(dev->netdev); 152 } 153 rtnl_unlock(); 154 } 155 static DECLARE_WORK(close_worker, close_work); 156 157 static void chnl_hold(struct cflayer *lyr) 158 { 159 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); 160 dev_hold(priv->netdev); 161 } 162 163 static void chnl_put(struct cflayer *lyr) 164 { 165 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); 166 dev_put(priv->netdev); 167 } 168 169 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow, 170 int phyid) 171 { 172 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl); 173 pr_debug("NET flowctrl func called flow: %s\n", 174 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" : 175 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" : 176 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" : 177 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" : 178 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" : 179 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? 180 "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND"); 181 182 183 184 switch (flow) { 185 case CAIF_CTRLCMD_FLOW_OFF_IND: 186 priv->flowenabled = false; 187 netif_stop_queue(priv->netdev); 188 break; 189 case CAIF_CTRLCMD_DEINIT_RSP: 190 priv->state = CAIF_DISCONNECTED; 191 break; 192 case CAIF_CTRLCMD_INIT_FAIL_RSP: 193 priv->state = CAIF_DISCONNECTED; 194 wake_up_interruptible(&priv->netmgmt_wq); 195 break; 196 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 197 priv->state = CAIF_SHUTDOWN; 198 netif_tx_disable(priv->netdev); 199 schedule_work(&close_worker); 200 break; 201 case CAIF_CTRLCMD_FLOW_ON_IND: 202 priv->flowenabled = true; 203 netif_wake_queue(priv->netdev); 204 break; 205 case CAIF_CTRLCMD_INIT_RSP: 206 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put); 207 priv->state = CAIF_CONNECTED; 208 priv->flowenabled = true; 209 netif_wake_queue(priv->netdev); 210 wake_up_interruptible(&priv->netmgmt_wq); 211 break; 212 default: 213 break; 214 } 215 } 216 217 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev) 218 { 219 struct chnl_net *priv; 220 struct cfpkt *pkt = NULL; 221 int len; 222 int result = -1; 223 /* Get our private data. */ 224 priv = netdev_priv(dev); 225 226 if (skb->len > priv->netdev->mtu) { 227 pr_warn("Size of skb exceeded MTU\n"); 228 kfree_skb(skb); 229 dev->stats.tx_errors++; 230 return NETDEV_TX_OK; 231 } 232 233 if (!priv->flowenabled) { 234 pr_debug("dropping packets flow off\n"); 235 kfree_skb(skb); 236 dev->stats.tx_dropped++; 237 return NETDEV_TX_OK; 238 } 239 240 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 241 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); 242 243 /* Store original SKB length. */ 244 len = skb->len; 245 246 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb); 247 248 /* Send the packet down the stack. */ 249 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt); 250 if (result) { 251 dev->stats.tx_dropped++; 252 return NETDEV_TX_OK; 253 } 254 255 /* Update statistics. */ 256 dev->stats.tx_packets++; 257 dev->stats.tx_bytes += len; 258 259 return NETDEV_TX_OK; 260 } 261 262 static int chnl_net_open(struct net_device *dev) 263 { 264 struct chnl_net *priv = NULL; 265 int result = -1; 266 int llifindex, headroom, tailroom, mtu; 267 struct net_device *lldev; 268 ASSERT_RTNL(); 269 priv = netdev_priv(dev); 270 if (!priv) { 271 pr_debug("chnl_net_open: no priv\n"); 272 return -ENODEV; 273 } 274 275 if (priv->state != CAIF_CONNECTING) { 276 priv->state = CAIF_CONNECTING; 277 result = caif_connect_client(dev_net(dev), &priv->conn_req, 278 &priv->chnl, &llifindex, 279 &headroom, &tailroom); 280 if (result != 0) { 281 pr_debug("err: " 282 "Unable to register and open device," 283 " Err:%d\n", 284 result); 285 goto error; 286 } 287 288 lldev = __dev_get_by_index(dev_net(dev), llifindex); 289 290 if (lldev == NULL) { 291 pr_debug("no interface?\n"); 292 result = -ENODEV; 293 goto error; 294 } 295 296 dev->needed_tailroom = tailroom + lldev->needed_tailroom; 297 dev->hard_header_len = headroom + lldev->hard_header_len + 298 lldev->needed_tailroom; 299 300 /* 301 * MTU, head-room etc is not know before we have a 302 * CAIF link layer device available. MTU calculation may 303 * override initial RTNL configuration. 304 * MTU is minimum of current mtu, link layer mtu pluss 305 * CAIF head and tail, and PDP GPRS contexts max MTU. 306 */ 307 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom)); 308 mtu = min_t(int, GPRS_PDP_MTU, mtu); 309 dev_set_mtu(dev, mtu); 310 311 if (mtu < 100) { 312 pr_warn("CAIF Interface MTU too small (%d)\n", mtu); 313 result = -ENODEV; 314 goto error; 315 } 316 } 317 318 rtnl_unlock(); /* Release RTNL lock during connect wait */ 319 320 result = wait_event_interruptible_timeout(priv->netmgmt_wq, 321 priv->state != CAIF_CONNECTING, 322 CONNECT_TIMEOUT); 323 324 rtnl_lock(); 325 326 if (result == -ERESTARTSYS) { 327 pr_debug("wait_event_interruptible woken by a signal\n"); 328 result = -ERESTARTSYS; 329 goto error; 330 } 331 332 if (result == 0) { 333 pr_debug("connect timeout\n"); 334 caif_disconnect_client(dev_net(dev), &priv->chnl); 335 priv->state = CAIF_DISCONNECTED; 336 pr_debug("state disconnected\n"); 337 result = -ETIMEDOUT; 338 goto error; 339 } 340 341 if (priv->state != CAIF_CONNECTED) { 342 pr_debug("connect failed\n"); 343 result = -ECONNREFUSED; 344 goto error; 345 } 346 pr_debug("CAIF Netdevice connected\n"); 347 return 0; 348 349 error: 350 caif_disconnect_client(dev_net(dev), &priv->chnl); 351 priv->state = CAIF_DISCONNECTED; 352 pr_debug("state disconnected\n"); 353 return result; 354 355 } 356 357 static int chnl_net_stop(struct net_device *dev) 358 { 359 struct chnl_net *priv; 360 361 ASSERT_RTNL(); 362 priv = netdev_priv(dev); 363 priv->state = CAIF_DISCONNECTED; 364 caif_disconnect_client(dev_net(dev), &priv->chnl); 365 return 0; 366 } 367 368 static int chnl_net_init(struct net_device *dev) 369 { 370 struct chnl_net *priv; 371 ASSERT_RTNL(); 372 priv = netdev_priv(dev); 373 strncpy(priv->name, dev->name, sizeof(priv->name)); 374 return 0; 375 } 376 377 static void chnl_net_uninit(struct net_device *dev) 378 { 379 struct chnl_net *priv; 380 ASSERT_RTNL(); 381 priv = netdev_priv(dev); 382 robust_list_del(&priv->list_field); 383 } 384 385 static const struct net_device_ops netdev_ops = { 386 .ndo_open = chnl_net_open, 387 .ndo_stop = chnl_net_stop, 388 .ndo_init = chnl_net_init, 389 .ndo_uninit = chnl_net_uninit, 390 .ndo_start_xmit = chnl_net_start_xmit, 391 }; 392 393 static void chnl_net_destructor(struct net_device *dev) 394 { 395 struct chnl_net *priv = netdev_priv(dev); 396 caif_free_client(&priv->chnl); 397 free_netdev(dev); 398 } 399 400 static void ipcaif_net_setup(struct net_device *dev) 401 { 402 struct chnl_net *priv; 403 dev->netdev_ops = &netdev_ops; 404 dev->destructor = chnl_net_destructor; 405 dev->flags |= IFF_NOARP; 406 dev->flags |= IFF_POINTOPOINT; 407 dev->mtu = GPRS_PDP_MTU; 408 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN; 409 410 priv = netdev_priv(dev); 411 priv->chnl.receive = chnl_recv_cb; 412 priv->chnl.ctrlcmd = chnl_flowctrl_cb; 413 priv->netdev = dev; 414 priv->conn_req.protocol = CAIFPROTO_DATAGRAM; 415 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW; 416 priv->conn_req.priority = CAIF_PRIO_LOW; 417 /* Insert illegal value */ 418 priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID; 419 priv->flowenabled = false; 420 421 init_waitqueue_head(&priv->netmgmt_wq); 422 } 423 424 425 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev) 426 { 427 struct chnl_net *priv; 428 u8 loop; 429 priv = netdev_priv(dev); 430 if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID, 431 priv->conn_req.sockaddr.u.dgm.connection_id) || 432 nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID, 433 priv->conn_req.sockaddr.u.dgm.connection_id)) 434 goto nla_put_failure; 435 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; 436 if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop)) 437 goto nla_put_failure; 438 return 0; 439 nla_put_failure: 440 return -EMSGSIZE; 441 442 } 443 444 static void caif_netlink_parms(struct nlattr *data[], 445 struct caif_connect_request *conn_req) 446 { 447 if (!data) { 448 pr_warn("no params data found\n"); 449 return; 450 } 451 if (data[IFLA_CAIF_IPV4_CONNID]) 452 conn_req->sockaddr.u.dgm.connection_id = 453 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]); 454 if (data[IFLA_CAIF_IPV6_CONNID]) 455 conn_req->sockaddr.u.dgm.connection_id = 456 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]); 457 if (data[IFLA_CAIF_LOOPBACK]) { 458 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK])) 459 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP; 460 else 461 conn_req->protocol = CAIFPROTO_DATAGRAM; 462 } 463 } 464 465 static int ipcaif_newlink(struct net *src_net, struct net_device *dev, 466 struct nlattr *tb[], struct nlattr *data[]) 467 { 468 int ret; 469 struct chnl_net *caifdev; 470 ASSERT_RTNL(); 471 caifdev = netdev_priv(dev); 472 caif_netlink_parms(data, &caifdev->conn_req); 473 474 ret = register_netdevice(dev); 475 if (ret) 476 pr_warn("device rtml registration failed\n"); 477 else 478 list_add(&caifdev->list_field, &chnl_net_list); 479 480 /* Use ifindex as connection id, and use loopback channel default. */ 481 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) { 482 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex; 483 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP; 484 } 485 return ret; 486 } 487 488 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], 489 struct nlattr *data[]) 490 { 491 struct chnl_net *caifdev; 492 ASSERT_RTNL(); 493 caifdev = netdev_priv(dev); 494 caif_netlink_parms(data, &caifdev->conn_req); 495 netdev_state_change(dev); 496 return 0; 497 } 498 499 static size_t ipcaif_get_size(const struct net_device *dev) 500 { 501 return 502 /* IFLA_CAIF_IPV4_CONNID */ 503 nla_total_size(4) + 504 /* IFLA_CAIF_IPV6_CONNID */ 505 nla_total_size(4) + 506 /* IFLA_CAIF_LOOPBACK */ 507 nla_total_size(2) + 508 0; 509 } 510 511 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { 512 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, 513 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, 514 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } 515 }; 516 517 518 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { 519 .kind = "caif", 520 .priv_size = sizeof(struct chnl_net), 521 .setup = ipcaif_net_setup, 522 .maxtype = IFLA_CAIF_MAX, 523 .policy = ipcaif_policy, 524 .newlink = ipcaif_newlink, 525 .changelink = ipcaif_changelink, 526 .get_size = ipcaif_get_size, 527 .fill_info = ipcaif_fill_info, 528 529 }; 530 531 static int __init chnl_init_module(void) 532 { 533 return rtnl_link_register(&ipcaif_link_ops); 534 } 535 536 static void __exit chnl_exit_module(void) 537 { 538 struct chnl_net *dev = NULL; 539 struct list_head *list_node; 540 struct list_head *_tmp; 541 rtnl_link_unregister(&ipcaif_link_ops); 542 rtnl_lock(); 543 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 544 dev = list_entry(list_node, struct chnl_net, list_field); 545 list_del(list_node); 546 delete_device(dev); 547 } 548 rtnl_unlock(); 549 } 550 551 module_init(chnl_init_module); 552 module_exit(chnl_exit_module); 553