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/cfcnfg.h> 24 #include <net/caif/cfpkt.h> 25 #include <net/caif/caif_dev.h> 26 27 /* GPRS PDP connection has MTU to 1500 */ 28 #define GPRS_PDP_MTU 1500 29 /* 5 sec. connect timeout */ 30 #define CONNECT_TIMEOUT (5 * HZ) 31 #define CAIF_NET_DEFAULT_QUEUE_LEN 500 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 = container_of(layr, struct chnl_net, chnl); 77 int pktlen; 78 int err = 0; 79 const u8 *ip_version; 80 u8 buf; 81 82 priv = container_of(layr, struct chnl_net, chnl); 83 84 if (!priv) 85 return -EINVAL; 86 87 /* Get length of CAIF packet. */ 88 pktlen = cfpkt_getlen(pkt); 89 90 skb = (struct sk_buff *) cfpkt_tonative(pkt); 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_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow, 157 int phyid) 158 { 159 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl); 160 pr_debug("NET flowctrl func called flow: %s\n", 161 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" : 162 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" : 163 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" : 164 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" : 165 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" : 166 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? 167 "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND"); 168 169 170 171 switch (flow) { 172 case CAIF_CTRLCMD_FLOW_OFF_IND: 173 priv->flowenabled = false; 174 netif_stop_queue(priv->netdev); 175 break; 176 case CAIF_CTRLCMD_DEINIT_RSP: 177 priv->state = CAIF_DISCONNECTED; 178 break; 179 case CAIF_CTRLCMD_INIT_FAIL_RSP: 180 priv->state = CAIF_DISCONNECTED; 181 wake_up_interruptible(&priv->netmgmt_wq); 182 break; 183 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 184 priv->state = CAIF_SHUTDOWN; 185 netif_tx_disable(priv->netdev); 186 schedule_work(&close_worker); 187 break; 188 case CAIF_CTRLCMD_FLOW_ON_IND: 189 priv->flowenabled = true; 190 netif_wake_queue(priv->netdev); 191 break; 192 case CAIF_CTRLCMD_INIT_RSP: 193 priv->state = CAIF_CONNECTED; 194 priv->flowenabled = true; 195 netif_wake_queue(priv->netdev); 196 wake_up_interruptible(&priv->netmgmt_wq); 197 break; 198 default: 199 break; 200 } 201 } 202 203 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev) 204 { 205 struct chnl_net *priv; 206 struct cfpkt *pkt = NULL; 207 int len; 208 int result = -1; 209 /* Get our private data. */ 210 priv = netdev_priv(dev); 211 212 if (skb->len > priv->netdev->mtu) { 213 pr_warn("Size of skb exceeded MTU\n"); 214 return -ENOSPC; 215 } 216 217 if (!priv->flowenabled) { 218 pr_debug("dropping packets flow off\n"); 219 return NETDEV_TX_BUSY; 220 } 221 222 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 223 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); 224 225 /* Store original SKB length. */ 226 len = skb->len; 227 228 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb); 229 230 /* Send the packet down the stack. */ 231 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt); 232 if (result) { 233 if (result == -EAGAIN) 234 result = NETDEV_TX_BUSY; 235 return result; 236 } 237 238 /* Update statistics. */ 239 dev->stats.tx_packets++; 240 dev->stats.tx_bytes += len; 241 242 return NETDEV_TX_OK; 243 } 244 245 static int chnl_net_open(struct net_device *dev) 246 { 247 struct chnl_net *priv = NULL; 248 int result = -1; 249 int llifindex, headroom, tailroom, mtu; 250 struct net_device *lldev; 251 ASSERT_RTNL(); 252 priv = netdev_priv(dev); 253 if (!priv) { 254 pr_debug("chnl_net_open: no priv\n"); 255 return -ENODEV; 256 } 257 258 if (priv->state != CAIF_CONNECTING) { 259 priv->state = CAIF_CONNECTING; 260 result = caif_connect_client(&priv->conn_req, &priv->chnl, 261 &llifindex, &headroom, &tailroom); 262 if (result != 0) { 263 pr_debug("err: " 264 "Unable to register and open device," 265 " Err:%d\n", 266 result); 267 goto error; 268 } 269 270 lldev = dev_get_by_index(dev_net(dev), llifindex); 271 272 if (lldev == NULL) { 273 pr_debug("no interface?\n"); 274 result = -ENODEV; 275 goto error; 276 } 277 278 dev->needed_tailroom = tailroom + lldev->needed_tailroom; 279 dev->hard_header_len = headroom + lldev->hard_header_len + 280 lldev->needed_tailroom; 281 282 /* 283 * MTU, head-room etc is not know before we have a 284 * CAIF link layer device available. MTU calculation may 285 * override initial RTNL configuration. 286 * MTU is minimum of current mtu, link layer mtu pluss 287 * CAIF head and tail, and PDP GPRS contexts max MTU. 288 */ 289 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom)); 290 mtu = min_t(int, GPRS_PDP_MTU, mtu); 291 dev_set_mtu(dev, mtu); 292 dev_put(lldev); 293 294 if (mtu < 100) { 295 pr_warn("CAIF Interface MTU too small (%d)\n", mtu); 296 result = -ENODEV; 297 goto error; 298 } 299 } 300 301 rtnl_unlock(); /* Release RTNL lock during connect wait */ 302 303 result = wait_event_interruptible_timeout(priv->netmgmt_wq, 304 priv->state != CAIF_CONNECTING, 305 CONNECT_TIMEOUT); 306 307 rtnl_lock(); 308 309 if (result == -ERESTARTSYS) { 310 pr_debug("wait_event_interruptible woken by a signal\n"); 311 result = -ERESTARTSYS; 312 goto error; 313 } 314 315 if (result == 0) { 316 pr_debug("connect timeout\n"); 317 caif_disconnect_client(&priv->chnl); 318 priv->state = CAIF_DISCONNECTED; 319 pr_debug("state disconnected\n"); 320 result = -ETIMEDOUT; 321 goto error; 322 } 323 324 if (priv->state != CAIF_CONNECTED) { 325 pr_debug("connect failed\n"); 326 result = -ECONNREFUSED; 327 goto error; 328 } 329 pr_debug("CAIF Netdevice connected\n"); 330 return 0; 331 332 error: 333 caif_disconnect_client(&priv->chnl); 334 priv->state = CAIF_DISCONNECTED; 335 pr_debug("state disconnected\n"); 336 return result; 337 338 } 339 340 static int chnl_net_stop(struct net_device *dev) 341 { 342 struct chnl_net *priv; 343 344 ASSERT_RTNL(); 345 priv = netdev_priv(dev); 346 priv->state = CAIF_DISCONNECTED; 347 caif_disconnect_client(&priv->chnl); 348 return 0; 349 } 350 351 static int chnl_net_init(struct net_device *dev) 352 { 353 struct chnl_net *priv; 354 ASSERT_RTNL(); 355 priv = netdev_priv(dev); 356 strncpy(priv->name, dev->name, sizeof(priv->name)); 357 return 0; 358 } 359 360 static void chnl_net_uninit(struct net_device *dev) 361 { 362 struct chnl_net *priv; 363 ASSERT_RTNL(); 364 priv = netdev_priv(dev); 365 robust_list_del(&priv->list_field); 366 } 367 368 static const struct net_device_ops netdev_ops = { 369 .ndo_open = chnl_net_open, 370 .ndo_stop = chnl_net_stop, 371 .ndo_init = chnl_net_init, 372 .ndo_uninit = chnl_net_uninit, 373 .ndo_start_xmit = chnl_net_start_xmit, 374 }; 375 376 static void ipcaif_net_setup(struct net_device *dev) 377 { 378 struct chnl_net *priv; 379 dev->netdev_ops = &netdev_ops; 380 dev->destructor = free_netdev; 381 dev->flags |= IFF_NOARP; 382 dev->flags |= IFF_POINTOPOINT; 383 dev->mtu = GPRS_PDP_MTU; 384 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN; 385 386 priv = netdev_priv(dev); 387 priv->chnl.receive = chnl_recv_cb; 388 priv->chnl.ctrlcmd = chnl_flowctrl_cb; 389 priv->netdev = dev; 390 priv->conn_req.protocol = CAIFPROTO_DATAGRAM; 391 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW; 392 priv->conn_req.priority = CAIF_PRIO_LOW; 393 /* Insert illegal value */ 394 priv->conn_req.sockaddr.u.dgm.connection_id = -1; 395 priv->flowenabled = false; 396 397 init_waitqueue_head(&priv->netmgmt_wq); 398 } 399 400 401 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev) 402 { 403 struct chnl_net *priv; 404 u8 loop; 405 priv = netdev_priv(dev); 406 NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID, 407 priv->conn_req.sockaddr.u.dgm.connection_id); 408 NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID, 409 priv->conn_req.sockaddr.u.dgm.connection_id); 410 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; 411 NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop); 412 413 414 return 0; 415 nla_put_failure: 416 return -EMSGSIZE; 417 418 } 419 420 static void caif_netlink_parms(struct nlattr *data[], 421 struct caif_connect_request *conn_req) 422 { 423 if (!data) { 424 pr_warn("no params data found\n"); 425 return; 426 } 427 if (data[IFLA_CAIF_IPV4_CONNID]) 428 conn_req->sockaddr.u.dgm.connection_id = 429 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]); 430 if (data[IFLA_CAIF_IPV6_CONNID]) 431 conn_req->sockaddr.u.dgm.connection_id = 432 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]); 433 if (data[IFLA_CAIF_LOOPBACK]) { 434 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK])) 435 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP; 436 else 437 conn_req->protocol = CAIFPROTO_DATAGRAM; 438 } 439 } 440 441 static int ipcaif_newlink(struct net *src_net, struct net_device *dev, 442 struct nlattr *tb[], struct nlattr *data[]) 443 { 444 int ret; 445 struct chnl_net *caifdev; 446 ASSERT_RTNL(); 447 caifdev = netdev_priv(dev); 448 caif_netlink_parms(data, &caifdev->conn_req); 449 dev_net_set(caifdev->netdev, src_net); 450 451 ret = register_netdevice(dev); 452 if (ret) 453 pr_warn("device rtml registration failed\n"); 454 else 455 list_add(&caifdev->list_field, &chnl_net_list); 456 return ret; 457 } 458 459 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], 460 struct nlattr *data[]) 461 { 462 struct chnl_net *caifdev; 463 ASSERT_RTNL(); 464 caifdev = netdev_priv(dev); 465 caif_netlink_parms(data, &caifdev->conn_req); 466 netdev_state_change(dev); 467 return 0; 468 } 469 470 static size_t ipcaif_get_size(const struct net_device *dev) 471 { 472 return 473 /* IFLA_CAIF_IPV4_CONNID */ 474 nla_total_size(4) + 475 /* IFLA_CAIF_IPV6_CONNID */ 476 nla_total_size(4) + 477 /* IFLA_CAIF_LOOPBACK */ 478 nla_total_size(2) + 479 0; 480 } 481 482 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { 483 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, 484 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, 485 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } 486 }; 487 488 489 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { 490 .kind = "caif", 491 .priv_size = sizeof(struct chnl_net), 492 .setup = ipcaif_net_setup, 493 .maxtype = IFLA_CAIF_MAX, 494 .policy = ipcaif_policy, 495 .newlink = ipcaif_newlink, 496 .changelink = ipcaif_changelink, 497 .get_size = ipcaif_get_size, 498 .fill_info = ipcaif_fill_info, 499 500 }; 501 502 static int __init chnl_init_module(void) 503 { 504 return rtnl_link_register(&ipcaif_link_ops); 505 } 506 507 static void __exit chnl_exit_module(void) 508 { 509 struct chnl_net *dev = NULL; 510 struct list_head *list_node; 511 struct list_head *_tmp; 512 rtnl_link_unregister(&ipcaif_link_ops); 513 rtnl_lock(); 514 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 515 dev = list_entry(list_node, struct chnl_net, list_field); 516 list_del(list_node); 517 delete_device(dev); 518 } 519 rtnl_unlock(); 520 } 521 522 module_init(chnl_init_module); 523 module_exit(chnl_exit_module); 524