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/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 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 97 switch (*ip_version >> 4) { 98 case 4: 99 skb->protocol = htons(ETH_P_IP); 100 break; 101 case 6: 102 skb->protocol = htons(ETH_P_IPV6); 103 break; 104 default: 105 priv->netdev->stats.rx_errors++; 106 return -EINVAL; 107 } 108 109 /* If we change the header in loop mode, the checksum is corrupted. */ 110 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 111 skb->ip_summed = CHECKSUM_UNNECESSARY; 112 else 113 skb->ip_summed = CHECKSUM_NONE; 114 115 if (in_interrupt()) 116 netif_rx(skb); 117 else 118 netif_rx_ni(skb); 119 120 /* Update statistics. */ 121 priv->netdev->stats.rx_packets++; 122 priv->netdev->stats.rx_bytes += pktlen; 123 124 return 0; 125 } 126 127 static int delete_device(struct chnl_net *dev) 128 { 129 ASSERT_RTNL(); 130 if (dev->netdev) 131 unregister_netdevice(dev->netdev); 132 return 0; 133 } 134 135 static void close_work(struct work_struct *work) 136 { 137 struct chnl_net *dev = NULL; 138 struct list_head *list_node; 139 struct list_head *_tmp; 140 141 rtnl_lock(); 142 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 143 dev = list_entry(list_node, struct chnl_net, list_field); 144 if (dev->state == CAIF_SHUTDOWN) 145 dev_close(dev->netdev); 146 } 147 rtnl_unlock(); 148 } 149 static DECLARE_WORK(close_worker, close_work); 150 151 static void chnl_hold(struct cflayer *lyr) 152 { 153 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); 154 dev_hold(priv->netdev); 155 } 156 157 static void chnl_put(struct cflayer *lyr) 158 { 159 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl); 160 dev_put(priv->netdev); 161 } 162 163 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow, 164 int phyid) 165 { 166 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl); 167 pr_debug("NET flowctrl func called flow: %s\n", 168 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" : 169 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" : 170 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" : 171 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" : 172 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" : 173 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? 174 "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND"); 175 176 177 178 switch (flow) { 179 case CAIF_CTRLCMD_FLOW_OFF_IND: 180 priv->flowenabled = false; 181 netif_stop_queue(priv->netdev); 182 break; 183 case CAIF_CTRLCMD_DEINIT_RSP: 184 priv->state = CAIF_DISCONNECTED; 185 break; 186 case CAIF_CTRLCMD_INIT_FAIL_RSP: 187 priv->state = CAIF_DISCONNECTED; 188 wake_up_interruptible(&priv->netmgmt_wq); 189 break; 190 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 191 priv->state = CAIF_SHUTDOWN; 192 netif_tx_disable(priv->netdev); 193 schedule_work(&close_worker); 194 break; 195 case CAIF_CTRLCMD_FLOW_ON_IND: 196 priv->flowenabled = true; 197 netif_wake_queue(priv->netdev); 198 break; 199 case CAIF_CTRLCMD_INIT_RSP: 200 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put); 201 priv->state = CAIF_CONNECTED; 202 priv->flowenabled = true; 203 netif_wake_queue(priv->netdev); 204 wake_up_interruptible(&priv->netmgmt_wq); 205 break; 206 default: 207 break; 208 } 209 } 210 211 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev) 212 { 213 struct chnl_net *priv; 214 struct cfpkt *pkt = NULL; 215 int len; 216 int result = -1; 217 /* Get our private data. */ 218 priv = netdev_priv(dev); 219 220 if (skb->len > priv->netdev->mtu) { 221 pr_warn("Size of skb exceeded MTU\n"); 222 dev->stats.tx_errors++; 223 return -ENOSPC; 224 } 225 226 if (!priv->flowenabled) { 227 pr_debug("dropping packets flow off\n"); 228 dev->stats.tx_dropped++; 229 return NETDEV_TX_BUSY; 230 } 231 232 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 233 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); 234 235 /* Store original SKB length. */ 236 len = skb->len; 237 238 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb); 239 240 /* Send the packet down the stack. */ 241 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt); 242 if (result) { 243 dev->stats.tx_dropped++; 244 return result; 245 } 246 247 /* Update statistics. */ 248 dev->stats.tx_packets++; 249 dev->stats.tx_bytes += len; 250 251 return NETDEV_TX_OK; 252 } 253 254 static int chnl_net_open(struct net_device *dev) 255 { 256 struct chnl_net *priv = NULL; 257 int result = -1; 258 int llifindex, headroom, tailroom, mtu; 259 struct net_device *lldev; 260 ASSERT_RTNL(); 261 priv = netdev_priv(dev); 262 if (!priv) { 263 pr_debug("chnl_net_open: no priv\n"); 264 return -ENODEV; 265 } 266 267 if (priv->state != CAIF_CONNECTING) { 268 priv->state = CAIF_CONNECTING; 269 result = caif_connect_client(dev_net(dev), &priv->conn_req, 270 &priv->chnl, &llifindex, 271 &headroom, &tailroom); 272 if (result != 0) { 273 pr_debug("err: " 274 "Unable to register and open device," 275 " Err:%d\n", 276 result); 277 goto error; 278 } 279 280 lldev = dev_get_by_index(dev_net(dev), llifindex); 281 282 if (lldev == NULL) { 283 pr_debug("no interface?\n"); 284 result = -ENODEV; 285 goto error; 286 } 287 288 dev->needed_tailroom = tailroom + lldev->needed_tailroom; 289 dev->hard_header_len = headroom + lldev->hard_header_len + 290 lldev->needed_tailroom; 291 292 /* 293 * MTU, head-room etc is not know before we have a 294 * CAIF link layer device available. MTU calculation may 295 * override initial RTNL configuration. 296 * MTU is minimum of current mtu, link layer mtu pluss 297 * CAIF head and tail, and PDP GPRS contexts max MTU. 298 */ 299 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom)); 300 mtu = min_t(int, GPRS_PDP_MTU, mtu); 301 dev_set_mtu(dev, mtu); 302 dev_put(lldev); 303 304 if (mtu < 100) { 305 pr_warn("CAIF Interface MTU too small (%d)\n", mtu); 306 result = -ENODEV; 307 goto error; 308 } 309 } 310 311 rtnl_unlock(); /* Release RTNL lock during connect wait */ 312 313 result = wait_event_interruptible_timeout(priv->netmgmt_wq, 314 priv->state != CAIF_CONNECTING, 315 CONNECT_TIMEOUT); 316 317 rtnl_lock(); 318 319 if (result == -ERESTARTSYS) { 320 pr_debug("wait_event_interruptible woken by a signal\n"); 321 result = -ERESTARTSYS; 322 goto error; 323 } 324 325 if (result == 0) { 326 pr_debug("connect timeout\n"); 327 caif_disconnect_client(dev_net(dev), &priv->chnl); 328 priv->state = CAIF_DISCONNECTED; 329 pr_debug("state disconnected\n"); 330 result = -ETIMEDOUT; 331 goto error; 332 } 333 334 if (priv->state != CAIF_CONNECTED) { 335 pr_debug("connect failed\n"); 336 result = -ECONNREFUSED; 337 goto error; 338 } 339 pr_debug("CAIF Netdevice connected\n"); 340 return 0; 341 342 error: 343 caif_disconnect_client(dev_net(dev), &priv->chnl); 344 priv->state = CAIF_DISCONNECTED; 345 pr_debug("state disconnected\n"); 346 return result; 347 348 } 349 350 static int chnl_net_stop(struct net_device *dev) 351 { 352 struct chnl_net *priv; 353 354 ASSERT_RTNL(); 355 priv = netdev_priv(dev); 356 priv->state = CAIF_DISCONNECTED; 357 caif_disconnect_client(dev_net(dev), &priv->chnl); 358 return 0; 359 } 360 361 static int chnl_net_init(struct net_device *dev) 362 { 363 struct chnl_net *priv; 364 ASSERT_RTNL(); 365 priv = netdev_priv(dev); 366 strncpy(priv->name, dev->name, sizeof(priv->name)); 367 return 0; 368 } 369 370 static void chnl_net_uninit(struct net_device *dev) 371 { 372 struct chnl_net *priv; 373 ASSERT_RTNL(); 374 priv = netdev_priv(dev); 375 robust_list_del(&priv->list_field); 376 } 377 378 static const struct net_device_ops netdev_ops = { 379 .ndo_open = chnl_net_open, 380 .ndo_stop = chnl_net_stop, 381 .ndo_init = chnl_net_init, 382 .ndo_uninit = chnl_net_uninit, 383 .ndo_start_xmit = chnl_net_start_xmit, 384 }; 385 386 static void chnl_net_destructor(struct net_device *dev) 387 { 388 struct chnl_net *priv = netdev_priv(dev); 389 caif_free_client(&priv->chnl); 390 free_netdev(dev); 391 } 392 393 static void ipcaif_net_setup(struct net_device *dev) 394 { 395 struct chnl_net *priv; 396 dev->netdev_ops = &netdev_ops; 397 dev->destructor = chnl_net_destructor; 398 dev->flags |= IFF_NOARP; 399 dev->flags |= IFF_POINTOPOINT; 400 dev->mtu = GPRS_PDP_MTU; 401 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN; 402 403 priv = netdev_priv(dev); 404 priv->chnl.receive = chnl_recv_cb; 405 priv->chnl.ctrlcmd = chnl_flowctrl_cb; 406 priv->netdev = dev; 407 priv->conn_req.protocol = CAIFPROTO_DATAGRAM; 408 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW; 409 priv->conn_req.priority = CAIF_PRIO_LOW; 410 /* Insert illegal value */ 411 priv->conn_req.sockaddr.u.dgm.connection_id = 0; 412 priv->flowenabled = false; 413 414 init_waitqueue_head(&priv->netmgmt_wq); 415 } 416 417 418 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev) 419 { 420 struct chnl_net *priv; 421 u8 loop; 422 priv = netdev_priv(dev); 423 NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID, 424 priv->conn_req.sockaddr.u.dgm.connection_id); 425 NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID, 426 priv->conn_req.sockaddr.u.dgm.connection_id); 427 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; 428 NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop); 429 430 431 return 0; 432 nla_put_failure: 433 return -EMSGSIZE; 434 435 } 436 437 static void caif_netlink_parms(struct nlattr *data[], 438 struct caif_connect_request *conn_req) 439 { 440 if (!data) { 441 pr_warn("no params data found\n"); 442 return; 443 } 444 if (data[IFLA_CAIF_IPV4_CONNID]) 445 conn_req->sockaddr.u.dgm.connection_id = 446 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]); 447 if (data[IFLA_CAIF_IPV6_CONNID]) 448 conn_req->sockaddr.u.dgm.connection_id = 449 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]); 450 if (data[IFLA_CAIF_LOOPBACK]) { 451 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK])) 452 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP; 453 else 454 conn_req->protocol = CAIFPROTO_DATAGRAM; 455 } 456 } 457 458 static int ipcaif_newlink(struct net *src_net, struct net_device *dev, 459 struct nlattr *tb[], struct nlattr *data[]) 460 { 461 int ret; 462 struct chnl_net *caifdev; 463 ASSERT_RTNL(); 464 caifdev = netdev_priv(dev); 465 caif_netlink_parms(data, &caifdev->conn_req); 466 dev_net_set(caifdev->netdev, src_net); 467 468 ret = register_netdevice(dev); 469 if (ret) 470 pr_warn("device rtml registration failed\n"); 471 else 472 list_add(&caifdev->list_field, &chnl_net_list); 473 474 /* Take ifindex as connection-id if null */ 475 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == 0) 476 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex; 477 return ret; 478 } 479 480 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], 481 struct nlattr *data[]) 482 { 483 struct chnl_net *caifdev; 484 ASSERT_RTNL(); 485 caifdev = netdev_priv(dev); 486 caif_netlink_parms(data, &caifdev->conn_req); 487 netdev_state_change(dev); 488 return 0; 489 } 490 491 static size_t ipcaif_get_size(const struct net_device *dev) 492 { 493 return 494 /* IFLA_CAIF_IPV4_CONNID */ 495 nla_total_size(4) + 496 /* IFLA_CAIF_IPV6_CONNID */ 497 nla_total_size(4) + 498 /* IFLA_CAIF_LOOPBACK */ 499 nla_total_size(2) + 500 0; 501 } 502 503 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { 504 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, 505 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, 506 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } 507 }; 508 509 510 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { 511 .kind = "caif", 512 .priv_size = sizeof(struct chnl_net), 513 .setup = ipcaif_net_setup, 514 .maxtype = IFLA_CAIF_MAX, 515 .policy = ipcaif_policy, 516 .newlink = ipcaif_newlink, 517 .changelink = ipcaif_changelink, 518 .get_size = ipcaif_get_size, 519 .fill_info = ipcaif_fill_info, 520 521 }; 522 523 static int __init chnl_init_module(void) 524 { 525 return rtnl_link_register(&ipcaif_link_ops); 526 } 527 528 static void __exit chnl_exit_module(void) 529 { 530 struct chnl_net *dev = NULL; 531 struct list_head *list_node; 532 struct list_head *_tmp; 533 rtnl_link_unregister(&ipcaif_link_ops); 534 rtnl_lock(); 535 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 536 dev = list_entry(list_node, struct chnl_net, list_field); 537 list_del(list_node); 538 delete_device(dev); 539 } 540 rtnl_unlock(); 541 } 542 543 module_init(chnl_init_module); 544 module_exit(chnl_exit_module); 545