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