net/caif/chnl_net.c

   1 /*
   2  * Copyright (C) ST-Ericsson AB 2010
   3  * Authors:     Sjur Brendeland
   4  *              Daniel Martensson
   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/init.h>
  12 #include <linux/module.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/if_ether.h>
  15 #include <linux/ip.h>
  16 #include <linux/sched.h>
  17 #include <linux/sockios.h>
  18 #include <linux/caif/if_caif.h>
  19 #include <net/rtnetlink.h>
  20 #include <net/caif/caif_layer.h>
  21 #include <net/caif/cfpkt.h>
  22 #include <net/caif/caif_dev.h>
  23
  24 /* GPRS PDP connection has MTU to 1500 */
  25 #define GPRS_PDP_MTU 1500
  26 /* 5 sec. connect timeout */
  27 #define CONNECT_TIMEOUT (5 * HZ)
  28 #define CAIF_NET_DEFAULT_QUEUE_LEN 500
  29 #define UNDEF_CONNID 0xffffffff
  30
  31 /*This list is protected by the rtnl lock. */
  32 static LIST_HEAD(chnl_net_list);
  33
  34 MODULE_LICENSE("GPL");
  35 MODULE_ALIAS_RTNL_LINK("caif");
  36
  37 enum caif_states {
  38         CAIF_CONNECTED          = 1,
  39         CAIF_CONNECTING,
  40         CAIF_DISCONNECTED,
  41         CAIF_SHUTDOWN
  42 };
  43
  44 struct chnl_net {
  45         struct cflayer chnl;
  46         struct caif_connect_request conn_req;
  47         struct list_head list_field;
  48         struct net_device *netdev;
  49         char name[256];
  50         wait_queue_head_t netmgmt_wq;
  51         /* Flow status to remember and control the transmission. */
  52         bool flowenabled;
  53         enum caif_states state;
  54 };
  55
  56 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
  57 {
  58         struct sk_buff *skb;
  59         struct chnl_net *priv;
  60         int pktlen;
  61         const u8 *ip_version;
  62         u8 buf;
  63
  64         priv = container_of(layr, struct chnl_net, chnl);
  65         if (!priv)
  66                 return -EINVAL;
  67
  68         skb = (struct sk_buff *) cfpkt_tonative(pkt);
  69
  70         /* Get length of CAIF packet. */
  71         pktlen = skb->len;
  72
  73         /* Pass some minimum information and
  74          * send the packet to the net stack.
  75          */
  76         skb->dev = priv->netdev;
  77
  78         /* check the version of IP */
  79         ip_version = skb_header_pointer(skb, 0, 1, &buf);
  80         if (!ip_version) {
  81                 kfree_skb(skb);
  82                 return -EINVAL;
  83         }
  84
  85         switch (*ip_version >> 4) {
  86         case 4:
  87                 skb->protocol = htons(ETH_P_IP);
  88                 break;
  89         case 6:
  90                 skb->protocol = htons(ETH_P_IPV6);
  91                 break;
  92         default:
  93                 kfree_skb(skb);
  94                 priv->netdev->stats.rx_errors++;
  95                 return -EINVAL;
  96         }
  97
  98         /* If we change the header in loop mode, the checksum is corrupted. */
  99         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 100                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 101         else
 102                 skb->ip_summed = CHECKSUM_NONE;
 103
 104         if (in_interrupt())
 105                 netif_rx(skb);
 106         else
 107                 netif_rx_ni(skb);
 108
 109         /* Update statistics. */
 110         priv->netdev->stats.rx_packets++;
 111         priv->netdev->stats.rx_bytes += pktlen;
 112
 113         return 0;
 114 }
 115
 116 static int delete_device(struct chnl_net *dev)
 117 {
 118         ASSERT_RTNL();
 119         if (dev->netdev)
 120                 unregister_netdevice(dev->netdev);
 121         return 0;
 122 }
 123
 124 static void close_work(struct work_struct *work)
 125 {
 126         struct chnl_net *dev = NULL;
 127         struct list_head *list_node;
 128         struct list_head *_tmp;
 129
 130         rtnl_lock();
 131         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 132                 dev = list_entry(list_node, struct chnl_net, list_field);
 133                 if (dev->state == CAIF_SHUTDOWN)
 134                         dev_close(dev->netdev);
 135         }
 136         rtnl_unlock();
 137 }
 138 static DECLARE_WORK(close_worker, close_work);
 139
 140 static void chnl_hold(struct cflayer *lyr)
 141 {
 142         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 143         dev_hold(priv->netdev);
 144 }
 145
 146 static void chnl_put(struct cflayer *lyr)
 147 {
 148         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 149         dev_put(priv->netdev);
 150 }
 151
 152 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
 153                              int phyid)
 154 {
 155         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
 156         pr_debug("NET flowctrl func called flow: %s\n",
 157                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
 158                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
 159                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
 160                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
 161                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
 162                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
 163                  "REMOTE_SHUTDOWN" : "UNKNOWN CTRL COMMAND");
 164
 165
 166
 167         switch (flow) {
 168         case CAIF_CTRLCMD_FLOW_OFF_IND:
 169                 priv->flowenabled = false;
 170                 netif_stop_queue(priv->netdev);
 171                 break;
 172         case CAIF_CTRLCMD_DEINIT_RSP:
 173                 priv->state = CAIF_DISCONNECTED;
 174                 break;
 175         case CAIF_CTRLCMD_INIT_FAIL_RSP:
 176                 priv->state = CAIF_DISCONNECTED;
 177                 wake_up_interruptible(&priv->netmgmt_wq);
 178                 break;
 179         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
 180                 priv->state = CAIF_SHUTDOWN;
 181                 netif_tx_disable(priv->netdev);
 182                 schedule_work(&close_worker);
 183                 break;
 184         case CAIF_CTRLCMD_FLOW_ON_IND:
 185                 priv->flowenabled = true;
 186                 netif_wake_queue(priv->netdev);
 187                 break;
 188         case CAIF_CTRLCMD_INIT_RSP:
 189                 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
 190                 priv->state = CAIF_CONNECTED;
 191                 priv->flowenabled = true;
 192                 netif_wake_queue(priv->netdev);
 193                 wake_up_interruptible(&priv->netmgmt_wq);
 194                 break;
 195         default:
 196                 break;
 197         }
 198 }
 199
 200 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 201 {
 202         struct chnl_net *priv;
 203         struct cfpkt *pkt = NULL;
 204         int len;
 205         int result = -1;
 206         /* Get our private data. */
 207         priv = netdev_priv(dev);
 208
 209         if (skb->len > priv->netdev->mtu) {
 210                 pr_warn("Size of skb exceeded MTU\n");
 211                 kfree_skb(skb);
 212                 dev->stats.tx_errors++;
 213                 return NETDEV_TX_OK;
 214         }
 215
 216         if (!priv->flowenabled) {
 217                 pr_debug("dropping packets flow off\n");
 218                 kfree_skb(skb);
 219                 dev->stats.tx_dropped++;
 220                 return NETDEV_TX_OK;
 221         }
 222
 223         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 224                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
 225
 226         /* Store original SKB length. */
 227         len = skb->len;
 228
 229         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
 230
 231         /* Send the packet down the stack. */
 232         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
 233         if (result) {
 234                 dev->stats.tx_dropped++;
 235                 return NETDEV_TX_OK;
 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(dev_net(dev), &priv->conn_req,
 261                                                 &priv->chnl, &llifindex,
 262                                                 &headroom, &tailroom);
 263                 if (result != 0) {
 264                                 pr_debug("err: "
 265                                          "Unable to register and open device,"
 266                                          " Err:%d\n",
 267                                          result);
 268                                 goto error;
 269                 }
 270
 271                 lldev = __dev_get_by_index(dev_net(dev), llifindex);
 272
 273                 if (lldev == NULL) {
 274                         pr_debug("no interface?\n");
 275                         result = -ENODEV;
 276                         goto error;
 277                 }
 278
 279                 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
 280                 dev->hard_header_len = headroom + lldev->hard_header_len +
 281                         lldev->needed_tailroom;
 282
 283                 /*
 284                  * MTU, head-room etc is not know before we have a
 285                  * CAIF link layer device available. MTU calculation may
 286                  * override initial RTNL configuration.
 287                  * MTU is minimum of current mtu, link layer mtu pluss
 288                  * CAIF head and tail, and PDP GPRS contexts max MTU.
 289                  */
 290                 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
 291                 mtu = min_t(int, GPRS_PDP_MTU, mtu);
 292                 dev_set_mtu(dev, mtu);
 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(dev_net(dev), &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(dev_net(dev), &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(dev_net(dev), &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         INIT_LIST_HEAD(&priv->list_field);
 358         return 0;
 359 }
 360
 361 static void chnl_net_uninit(struct net_device *dev)
 362 {
 363         struct chnl_net *priv;
 364         ASSERT_RTNL();
 365         priv = netdev_priv(dev);
 366         list_del_init(&priv->list_field);
 367 }
 368
 369 static const struct net_device_ops netdev_ops = {
 370         .ndo_open = chnl_net_open,
 371         .ndo_stop = chnl_net_stop,
 372         .ndo_init = chnl_net_init,
 373         .ndo_uninit = chnl_net_uninit,
 374         .ndo_start_xmit = chnl_net_start_xmit,
 375 };
 376
 377 static void chnl_net_destructor(struct net_device *dev)
 378 {
 379         struct chnl_net *priv = netdev_priv(dev);
 380         caif_free_client(&priv->chnl);
 381 }
 382
 383 static void ipcaif_net_setup(struct net_device *dev)
 384 {
 385         struct chnl_net *priv;
 386         dev->netdev_ops = &netdev_ops;
 387         dev->needs_free_netdev = true;
 388         dev->priv_destructor = chnl_net_destructor;
 389         dev->flags |= IFF_NOARP;
 390         dev->flags |= IFF_POINTOPOINT;
 391         dev->mtu = GPRS_PDP_MTU;
 392         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
 393
 394         priv = netdev_priv(dev);
 395         priv->chnl.receive = chnl_recv_cb;
 396         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
 397         priv->netdev = dev;
 398         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
 399         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
 400         priv->conn_req.priority = CAIF_PRIO_LOW;
 401         /* Insert illegal value */
 402         priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
 403         priv->flowenabled = false;
 404
 405         init_waitqueue_head(&priv->netmgmt_wq);
 406 }
 407
 408
 409 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
 410 {
 411         struct chnl_net *priv;
 412         u8 loop;
 413         priv = netdev_priv(dev);
 414         if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
 415                         priv->conn_req.sockaddr.u.dgm.connection_id) ||
 416             nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
 417                         priv->conn_req.sockaddr.u.dgm.connection_id))
 418                 goto nla_put_failure;
 419         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
 420         if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
 421                 goto nla_put_failure;
 422         return 0;
 423 nla_put_failure:
 424         return -EMSGSIZE;
 425
 426 }
 427
 428 static void caif_netlink_parms(struct nlattr *data[],
 429                                struct caif_connect_request *conn_req)
 430 {
 431         if (!data) {
 432                 pr_warn("no params data found\n");
 433                 return;
 434         }
 435         if (data[IFLA_CAIF_IPV4_CONNID])
 436                 conn_req->sockaddr.u.dgm.connection_id =
 437                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
 438         if (data[IFLA_CAIF_IPV6_CONNID])
 439                 conn_req->sockaddr.u.dgm.connection_id =
 440                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
 441         if (data[IFLA_CAIF_LOOPBACK]) {
 442                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
 443                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
 444                 else
 445                         conn_req->protocol = CAIFPROTO_DATAGRAM;
 446         }
 447 }
 448
 449 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
 450                           struct nlattr *tb[], struct nlattr *data[],
 451                           struct netlink_ext_ack *extack)
 452 {
 453         int ret;
 454         struct chnl_net *caifdev;
 455         ASSERT_RTNL();
 456         caifdev = netdev_priv(dev);
 457         caif_netlink_parms(data, &caifdev->conn_req);
 458
 459         ret = register_netdevice(dev);
 460         if (ret)
 461                 pr_warn("device rtml registration failed\n");
 462         else
 463                 list_add(&caifdev->list_field, &chnl_net_list);
 464
 465         /* Use ifindex as connection id, and use loopback channel default. */
 466         if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
 467                 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
 468                 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
 469         }
 470         return ret;
 471 }
 472
 473 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
 474                              struct nlattr *data[],
 475                              struct netlink_ext_ack *extack)
 476 {
 477         struct chnl_net *caifdev;
 478         ASSERT_RTNL();
 479         caifdev = netdev_priv(dev);
 480         caif_netlink_parms(data, &caifdev->conn_req);
 481         netdev_state_change(dev);
 482         return 0;
 483 }
 484
 485 static size_t ipcaif_get_size(const struct net_device *dev)
 486 {
 487         return
 488                 /* IFLA_CAIF_IPV4_CONNID */
 489                 nla_total_size(4) +
 490                 /* IFLA_CAIF_IPV6_CONNID */
 491                 nla_total_size(4) +
 492                 /* IFLA_CAIF_LOOPBACK */
 493                 nla_total_size(2) +
 494                 0;
 495 }
 496
 497 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
 498         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
 499         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
 500         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
 501 };
 502
 503
 504 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
 505         .kind           = "caif",
 506         .priv_size      = sizeof(struct chnl_net),
 507         .setup          = ipcaif_net_setup,
 508         .maxtype        = IFLA_CAIF_MAX,
 509         .policy         = ipcaif_policy,
 510         .newlink        = ipcaif_newlink,
 511         .changelink     = ipcaif_changelink,
 512         .get_size       = ipcaif_get_size,
 513         .fill_info      = ipcaif_fill_info,
 514
 515 };
 516
 517 static int __init chnl_init_module(void)
 518 {
 519         return rtnl_link_register(&ipcaif_link_ops);
 520 }
 521
 522 static void __exit chnl_exit_module(void)
 523 {
 524         struct chnl_net *dev = NULL;
 525         struct list_head *list_node;
 526         struct list_head *_tmp;
 527         rtnl_link_unregister(&ipcaif_link_ops);
 528         rtnl_lock();
 529         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 530                 dev = list_entry(list_node, struct chnl_net, list_field);
 531                 list_del_init(list_node);
 532                 delete_device(dev);
 533         }
 534         rtnl_unlock();
 535 }
 536
 537 module_init(chnl_init_module);
 538 module_exit(chnl_exit_module);