1 /* 2 * Copyright (C) ST-Ericsson AB 2010 3 * Authors: Sjur Brendeland/sjur.brandeland@stericsson.com 4 * Daniel Martensson / Daniel.Martensson@stericsson.com 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/version.h> 11 #include <linux/fs.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 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 = container_of(layr, struct chnl_net, chnl); 76 int pktlen; 77 int err = 0; 78 const u8 *ip_version; 79 u8 buf; 80 81 priv = container_of(layr, struct chnl_net, chnl); 82 83 if (!priv) 84 return -EINVAL; 85 86 skb = (struct sk_buff *) cfpkt_tonative(pkt); 87 88 /* Get length of CAIF packet. */ 89 pktlen = skb->len; 90 91 /* Pass some minimum information and 92 * send the packet to the net stack. 93 */ 94 skb->dev = priv->netdev; 95 96 /* check the version of IP */ 97 ip_version = skb_header_pointer(skb, 0, 1, &buf); 98 if (!ip_version) 99 return -EINVAL; 100 switch (*ip_version >> 4) { 101 case 4: 102 skb->protocol = htons(ETH_P_IP); 103 break; 104 case 6: 105 skb->protocol = htons(ETH_P_IPV6); 106 break; 107 default: 108 return -EINVAL; 109 } 110 111 /* If we change the header in loop mode, the checksum is corrupted. */ 112 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 113 skb->ip_summed = CHECKSUM_UNNECESSARY; 114 else 115 skb->ip_summed = CHECKSUM_NONE; 116 117 if (in_interrupt()) 118 netif_rx(skb); 119 else 120 netif_rx_ni(skb); 121 122 /* Update statistics. */ 123 priv->netdev->stats.rx_packets++; 124 priv->netdev->stats.rx_bytes += pktlen; 125 126 return err; 127 } 128 129 static int delete_device(struct chnl_net *dev) 130 { 131 ASSERT_RTNL(); 132 if (dev->netdev) 133 unregister_netdevice(dev->netdev); 134 return 0; 135 } 136 137 static void close_work(struct work_struct *work) 138 { 139 struct chnl_net *dev = NULL; 140 struct list_head *list_node; 141 struct list_head *_tmp; 142 /* May be called with or without RTNL lock held */ 143 int islocked = rtnl_is_locked(); 144 if (!islocked) 145 rtnl_lock(); 146 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 147 dev = list_entry(list_node, struct chnl_net, list_field); 148 if (dev->state == CAIF_SHUTDOWN) 149 dev_close(dev->netdev); 150 } 151 if (!islocked) 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 return -ENOSPC; 228 } 229 230 if (!priv->flowenabled) { 231 pr_debug("dropping packets flow off\n"); 232 return NETDEV_TX_BUSY; 233 } 234 235 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 236 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); 237 238 /* Store original SKB length. */ 239 len = skb->len; 240 241 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb); 242 243 /* Send the packet down the stack. */ 244 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt); 245 if (result) { 246 if (result == -EAGAIN) 247 result = NETDEV_TX_BUSY; 248 return result; 249 } 250 251 /* Update statistics. */ 252 dev->stats.tx_packets++; 253 dev->stats.tx_bytes += len; 254 255 return NETDEV_TX_OK; 256 } 257 258 static int chnl_net_open(struct net_device *dev) 259 { 260 struct chnl_net *priv = NULL; 261 int result = -1; 262 int llifindex, headroom, tailroom, mtu; 263 struct net_device *lldev; 264 ASSERT_RTNL(); 265 priv = netdev_priv(dev); 266 if (!priv) { 267 pr_debug("chnl_net_open: no priv\n"); 268 return -ENODEV; 269 } 270 271 if (priv->state != CAIF_CONNECTING) { 272 priv->state = CAIF_CONNECTING; 273 result = caif_connect_client(dev_net(dev), &priv->conn_req, 274 &priv->chnl, &llifindex, 275 &headroom, &tailroom); 276 if (result != 0) { 277 pr_debug("err: " 278 "Unable to register and open device," 279 " Err:%d\n", 280 result); 281 goto error; 282 } 283 284 lldev = dev_get_by_index(dev_net(dev), llifindex); 285 286 if (lldev == NULL) { 287 pr_debug("no interface?\n"); 288 result = -ENODEV; 289 goto error; 290 } 291 292 dev->needed_tailroom = tailroom + lldev->needed_tailroom; 293 dev->hard_header_len = headroom + lldev->hard_header_len + 294 lldev->needed_tailroom; 295 296 /* 297 * MTU, head-room etc is not know before we have a 298 * CAIF link layer device available. MTU calculation may 299 * override initial RTNL configuration. 300 * MTU is minimum of current mtu, link layer mtu pluss 301 * CAIF head and tail, and PDP GPRS contexts max MTU. 302 */ 303 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom)); 304 mtu = min_t(int, GPRS_PDP_MTU, mtu); 305 dev_set_mtu(dev, mtu); 306 dev_put(lldev); 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 free_netdev(dev); 395 } 396 397 static void ipcaif_net_setup(struct net_device *dev) 398 { 399 struct chnl_net *priv; 400 dev->netdev_ops = &netdev_ops; 401 dev->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 = 0; 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 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 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; 432 NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop); 433 434 435 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 { 465 int ret; 466 struct chnl_net *caifdev; 467 ASSERT_RTNL(); 468 caifdev = netdev_priv(dev); 469 caif_netlink_parms(data, &caifdev->conn_req); 470 dev_net_set(caifdev->netdev, src_net); 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 /* Take ifindex as connection-id if null */ 479 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == 0) 480 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex; 481 return ret; 482 } 483 484 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], 485 struct nlattr *data[]) 486 { 487 struct chnl_net *caifdev; 488 ASSERT_RTNL(); 489 caifdev = netdev_priv(dev); 490 caif_netlink_parms(data, &caifdev->conn_req); 491 netdev_state_change(dev); 492 return 0; 493 } 494 495 static size_t ipcaif_get_size(const struct net_device *dev) 496 { 497 return 498 /* IFLA_CAIF_IPV4_CONNID */ 499 nla_total_size(4) + 500 /* IFLA_CAIF_IPV6_CONNID */ 501 nla_total_size(4) + 502 /* IFLA_CAIF_LOOPBACK */ 503 nla_total_size(2) + 504 0; 505 } 506 507 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { 508 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, 509 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, 510 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } 511 }; 512 513 514 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { 515 .kind = "caif", 516 .priv_size = sizeof(struct chnl_net), 517 .setup = ipcaif_net_setup, 518 .maxtype = IFLA_CAIF_MAX, 519 .policy = ipcaif_policy, 520 .newlink = ipcaif_newlink, 521 .changelink = ipcaif_changelink, 522 .get_size = ipcaif_get_size, 523 .fill_info = ipcaif_fill_info, 524 525 }; 526 527 static int __init chnl_init_module(void) 528 { 529 return rtnl_link_register(&ipcaif_link_ops); 530 } 531 532 static void __exit chnl_exit_module(void) 533 { 534 struct chnl_net *dev = NULL; 535 struct list_head *list_node; 536 struct list_head *_tmp; 537 rtnl_link_unregister(&ipcaif_link_ops); 538 rtnl_lock(); 539 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 540 dev = list_entry(list_node, struct chnl_net, list_field); 541 list_del(list_node); 542 delete_device(dev); 543 } 544 rtnl_unlock(); 545 } 546 547 module_init(chnl_init_module); 548 module_exit(chnl_exit_module); 549