net/caif/chnl_net.c

   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);