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 80 priv = container_of(layr, struct chnl_net, chnl); 81 82 if (!priv) 83 return -EINVAL; 84 85 /* Get length of CAIF packet. */ 86 pktlen = cfpkt_getlen(pkt); 87 88 skb = (struct sk_buff *) cfpkt_tonative(pkt); 89 /* Pass some minimum information and 90 * send the packet to the net stack. 91 */ 92 skb->dev = priv->netdev; 93 skb->protocol = htons(ETH_P_IP); 94 95 /* If we change the header in loop mode, the checksum is corrupted. */ 96 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 97 skb->ip_summed = CHECKSUM_UNNECESSARY; 98 else 99 skb->ip_summed = CHECKSUM_NONE; 100 101 if (in_interrupt()) 102 netif_rx(skb); 103 else 104 netif_rx_ni(skb); 105 106 /* Update statistics. */ 107 priv->netdev->stats.rx_packets++; 108 priv->netdev->stats.rx_bytes += pktlen; 109 110 return err; 111 } 112 113 static int delete_device(struct chnl_net *dev) 114 { 115 ASSERT_RTNL(); 116 if (dev->netdev) 117 unregister_netdevice(dev->netdev); 118 return 0; 119 } 120 121 static void close_work(struct work_struct *work) 122 { 123 struct chnl_net *dev = NULL; 124 struct list_head *list_node; 125 struct list_head *_tmp; 126 /* May be called with or without RTNL lock held */ 127 int islocked = rtnl_is_locked(); 128 if (!islocked) 129 rtnl_lock(); 130 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 131 dev = list_entry(list_node, struct chnl_net, list_field); 132 if (dev->state == CAIF_SHUTDOWN) 133 dev_close(dev->netdev); 134 } 135 if (!islocked) 136 rtnl_unlock(); 137 } 138 static DECLARE_WORK(close_worker, close_work); 139 140 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow, 141 int phyid) 142 { 143 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl); 144 pr_debug("NET flowctrl func called flow: %s\n", 145 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" : 146 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" : 147 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" : 148 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" : 149 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" : 150 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? 151 "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND"); 152 153 154 155 switch (flow) { 156 case CAIF_CTRLCMD_FLOW_OFF_IND: 157 priv->flowenabled = false; 158 netif_stop_queue(priv->netdev); 159 break; 160 case CAIF_CTRLCMD_DEINIT_RSP: 161 priv->state = CAIF_DISCONNECTED; 162 break; 163 case CAIF_CTRLCMD_INIT_FAIL_RSP: 164 priv->state = CAIF_DISCONNECTED; 165 wake_up_interruptible(&priv->netmgmt_wq); 166 break; 167 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: 168 priv->state = CAIF_SHUTDOWN; 169 netif_tx_disable(priv->netdev); 170 schedule_work(&close_worker); 171 break; 172 case CAIF_CTRLCMD_FLOW_ON_IND: 173 priv->flowenabled = true; 174 netif_wake_queue(priv->netdev); 175 break; 176 case CAIF_CTRLCMD_INIT_RSP: 177 priv->state = CAIF_CONNECTED; 178 priv->flowenabled = true; 179 netif_wake_queue(priv->netdev); 180 wake_up_interruptible(&priv->netmgmt_wq); 181 break; 182 default: 183 break; 184 } 185 } 186 187 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev) 188 { 189 struct chnl_net *priv; 190 struct cfpkt *pkt = NULL; 191 int len; 192 int result = -1; 193 /* Get our private data. */ 194 priv = netdev_priv(dev); 195 196 if (skb->len > priv->netdev->mtu) { 197 pr_warn("Size of skb exceeded MTU\n"); 198 return -ENOSPC; 199 } 200 201 if (!priv->flowenabled) { 202 pr_debug("dropping packets flow off\n"); 203 return NETDEV_TX_BUSY; 204 } 205 206 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP) 207 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); 208 209 /* Store original SKB length. */ 210 len = skb->len; 211 212 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb); 213 214 /* Send the packet down the stack. */ 215 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt); 216 if (result) { 217 if (result == -EAGAIN) 218 result = NETDEV_TX_BUSY; 219 return result; 220 } 221 222 /* Update statistics. */ 223 dev->stats.tx_packets++; 224 dev->stats.tx_bytes += len; 225 226 return NETDEV_TX_OK; 227 } 228 229 static int chnl_net_open(struct net_device *dev) 230 { 231 struct chnl_net *priv = NULL; 232 int result = -1; 233 int llifindex, headroom, tailroom, mtu; 234 struct net_device *lldev; 235 ASSERT_RTNL(); 236 priv = netdev_priv(dev); 237 if (!priv) { 238 pr_debug("chnl_net_open: no priv\n"); 239 return -ENODEV; 240 } 241 242 if (priv->state != CAIF_CONNECTING) { 243 priv->state = CAIF_CONNECTING; 244 result = caif_connect_client(&priv->conn_req, &priv->chnl, 245 &llifindex, &headroom, &tailroom); 246 if (result != 0) { 247 pr_debug("err: " 248 "Unable to register and open device," 249 " Err:%d\n", 250 result); 251 goto error; 252 } 253 254 lldev = dev_get_by_index(dev_net(dev), llifindex); 255 256 if (lldev == NULL) { 257 pr_debug("no interface?\n"); 258 result = -ENODEV; 259 goto error; 260 } 261 262 dev->needed_tailroom = tailroom + lldev->needed_tailroom; 263 dev->hard_header_len = headroom + lldev->hard_header_len + 264 lldev->needed_tailroom; 265 266 /* 267 * MTU, head-room etc is not know before we have a 268 * CAIF link layer device available. MTU calculation may 269 * override initial RTNL configuration. 270 * MTU is minimum of current mtu, link layer mtu pluss 271 * CAIF head and tail, and PDP GPRS contexts max MTU. 272 */ 273 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom)); 274 mtu = min_t(int, GPRS_PDP_MTU, mtu); 275 dev_set_mtu(dev, mtu); 276 dev_put(lldev); 277 278 if (mtu < 100) { 279 pr_warn("CAIF Interface MTU too small (%d)\n", mtu); 280 result = -ENODEV; 281 goto error; 282 } 283 } 284 285 rtnl_unlock(); /* Release RTNL lock during connect wait */ 286 287 result = wait_event_interruptible_timeout(priv->netmgmt_wq, 288 priv->state != CAIF_CONNECTING, 289 CONNECT_TIMEOUT); 290 291 rtnl_lock(); 292 293 if (result == -ERESTARTSYS) { 294 pr_debug("wait_event_interruptible woken by a signal\n"); 295 result = -ERESTARTSYS; 296 goto error; 297 } 298 299 if (result == 0) { 300 pr_debug("connect timeout\n"); 301 caif_disconnect_client(&priv->chnl); 302 priv->state = CAIF_DISCONNECTED; 303 pr_debug("state disconnected\n"); 304 result = -ETIMEDOUT; 305 goto error; 306 } 307 308 if (priv->state != CAIF_CONNECTED) { 309 pr_debug("connect failed\n"); 310 result = -ECONNREFUSED; 311 goto error; 312 } 313 pr_debug("CAIF Netdevice connected\n"); 314 return 0; 315 316 error: 317 caif_disconnect_client(&priv->chnl); 318 priv->state = CAIF_DISCONNECTED; 319 pr_debug("state disconnected\n"); 320 return result; 321 322 } 323 324 static int chnl_net_stop(struct net_device *dev) 325 { 326 struct chnl_net *priv; 327 328 ASSERT_RTNL(); 329 priv = netdev_priv(dev); 330 priv->state = CAIF_DISCONNECTED; 331 caif_disconnect_client(&priv->chnl); 332 return 0; 333 } 334 335 static int chnl_net_init(struct net_device *dev) 336 { 337 struct chnl_net *priv; 338 ASSERT_RTNL(); 339 priv = netdev_priv(dev); 340 strncpy(priv->name, dev->name, sizeof(priv->name)); 341 return 0; 342 } 343 344 static void chnl_net_uninit(struct net_device *dev) 345 { 346 struct chnl_net *priv; 347 ASSERT_RTNL(); 348 priv = netdev_priv(dev); 349 robust_list_del(&priv->list_field); 350 } 351 352 static const struct net_device_ops netdev_ops = { 353 .ndo_open = chnl_net_open, 354 .ndo_stop = chnl_net_stop, 355 .ndo_init = chnl_net_init, 356 .ndo_uninit = chnl_net_uninit, 357 .ndo_start_xmit = chnl_net_start_xmit, 358 }; 359 360 static void ipcaif_net_setup(struct net_device *dev) 361 { 362 struct chnl_net *priv; 363 dev->netdev_ops = &netdev_ops; 364 dev->destructor = free_netdev; 365 dev->flags |= IFF_NOARP; 366 dev->flags |= IFF_POINTOPOINT; 367 dev->mtu = GPRS_PDP_MTU; 368 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN; 369 370 priv = netdev_priv(dev); 371 priv->chnl.receive = chnl_recv_cb; 372 priv->chnl.ctrlcmd = chnl_flowctrl_cb; 373 priv->netdev = dev; 374 priv->conn_req.protocol = CAIFPROTO_DATAGRAM; 375 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW; 376 priv->conn_req.priority = CAIF_PRIO_LOW; 377 /* Insert illegal value */ 378 priv->conn_req.sockaddr.u.dgm.connection_id = -1; 379 priv->flowenabled = false; 380 381 ASSERT_RTNL(); 382 init_waitqueue_head(&priv->netmgmt_wq); 383 list_add(&priv->list_field, &chnl_net_list); 384 } 385 386 387 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev) 388 { 389 struct chnl_net *priv; 390 u8 loop; 391 priv = netdev_priv(dev); 392 NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID, 393 priv->conn_req.sockaddr.u.dgm.connection_id); 394 NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID, 395 priv->conn_req.sockaddr.u.dgm.connection_id); 396 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP; 397 NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop); 398 399 400 return 0; 401 nla_put_failure: 402 return -EMSGSIZE; 403 404 } 405 406 static void caif_netlink_parms(struct nlattr *data[], 407 struct caif_connect_request *conn_req) 408 { 409 if (!data) { 410 pr_warn("no params data found\n"); 411 return; 412 } 413 if (data[IFLA_CAIF_IPV4_CONNID]) 414 conn_req->sockaddr.u.dgm.connection_id = 415 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]); 416 if (data[IFLA_CAIF_IPV6_CONNID]) 417 conn_req->sockaddr.u.dgm.connection_id = 418 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]); 419 if (data[IFLA_CAIF_LOOPBACK]) { 420 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK])) 421 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP; 422 else 423 conn_req->protocol = CAIFPROTO_DATAGRAM; 424 } 425 } 426 427 static int ipcaif_newlink(struct net *src_net, struct net_device *dev, 428 struct nlattr *tb[], struct nlattr *data[]) 429 { 430 int ret; 431 struct chnl_net *caifdev; 432 ASSERT_RTNL(); 433 caifdev = netdev_priv(dev); 434 caif_netlink_parms(data, &caifdev->conn_req); 435 dev_net_set(caifdev->netdev, src_net); 436 437 ret = register_netdevice(dev); 438 if (ret) 439 pr_warn("device rtml registration failed\n"); 440 return ret; 441 } 442 443 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[], 444 struct nlattr *data[]) 445 { 446 struct chnl_net *caifdev; 447 ASSERT_RTNL(); 448 caifdev = netdev_priv(dev); 449 caif_netlink_parms(data, &caifdev->conn_req); 450 netdev_state_change(dev); 451 return 0; 452 } 453 454 static size_t ipcaif_get_size(const struct net_device *dev) 455 { 456 return 457 /* IFLA_CAIF_IPV4_CONNID */ 458 nla_total_size(4) + 459 /* IFLA_CAIF_IPV6_CONNID */ 460 nla_total_size(4) + 461 /* IFLA_CAIF_LOOPBACK */ 462 nla_total_size(2) + 463 0; 464 } 465 466 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = { 467 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 }, 468 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 }, 469 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 } 470 }; 471 472 473 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = { 474 .kind = "caif", 475 .priv_size = sizeof(struct chnl_net), 476 .setup = ipcaif_net_setup, 477 .maxtype = IFLA_CAIF_MAX, 478 .policy = ipcaif_policy, 479 .newlink = ipcaif_newlink, 480 .changelink = ipcaif_changelink, 481 .get_size = ipcaif_get_size, 482 .fill_info = ipcaif_fill_info, 483 484 }; 485 486 static int __init chnl_init_module(void) 487 { 488 return rtnl_link_register(&ipcaif_link_ops); 489 } 490 491 static void __exit chnl_exit_module(void) 492 { 493 struct chnl_net *dev = NULL; 494 struct list_head *list_node; 495 struct list_head *_tmp; 496 rtnl_link_unregister(&ipcaif_link_ops); 497 rtnl_lock(); 498 list_for_each_safe(list_node, _tmp, &chnl_net_list) { 499 dev = list_entry(list_node, struct chnl_net, list_field); 500 list_del(list_node); 501 delete_device(dev); 502 } 503 rtnl_unlock(); 504 } 505 506 module_init(chnl_init_module); 507 module_exit(chnl_exit_module); 508