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/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 #define UNDEF_CONNID 0xffffffff
  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 int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
  60 {
  61         struct sk_buff *skb;
  62         struct chnl_net *priv;
  63         int pktlen;
  64         const u8 *ip_version;
  65         u8 buf;
  66
  67         priv = container_of(layr, struct chnl_net, chnl);
  68         if (!priv)
  69                 return -EINVAL;
  70
  71         skb = (struct sk_buff *) cfpkt_tonative(pkt);
  72
  73         /* Get length of CAIF packet. */
  74         pktlen = skb->len;
  75
  76         /* Pass some minimum information and
  77          * send the packet to the net stack.
  78          */
  79         skb->dev = priv->netdev;
  80
  81         /* check the version of IP */
  82         ip_version = skb_header_pointer(skb, 0, 1, &buf);
  83         if (!ip_version) {
  84                 kfree_skb(skb);
  85                 return -EINVAL;
  86         }
  87
  88         switch (*ip_version >> 4) {
  89         case 4:
  90                 skb->protocol = htons(ETH_P_IP);
  91                 break;
  92         case 6:
  93                 skb->protocol = htons(ETH_P_IPV6);
  94                 break;
  95         default:
  96                 kfree_skb(skb);
  97                 priv->netdev->stats.rx_errors++;
  98                 return -EINVAL;
  99         }
 100
 101         /* If we change the header in loop mode, the checksum is corrupted. */
 102         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 103                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 104         else
 105                 skb->ip_summed = CHECKSUM_NONE;
 106
 107         if (in_interrupt())
 108                 netif_rx(skb);
 109         else
 110                 netif_rx_ni(skb);
 111
 112         /* Update statistics. */
 113         priv->netdev->stats.rx_packets++;
 114         priv->netdev->stats.rx_bytes += pktlen;
 115
 116         return 0;
 117 }
 118
 119 static int delete_device(struct chnl_net *dev)
 120 {
 121         ASSERT_RTNL();
 122         if (dev->netdev)
 123                 unregister_netdevice(dev->netdev);
 124         return 0;
 125 }
 126
 127 static void close_work(struct work_struct *work)
 128 {
 129         struct chnl_net *dev = NULL;
 130         struct list_head *list_node;
 131         struct list_head *_tmp;
 132
 133         rtnl_lock();
 134         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 135                 dev = list_entry(list_node, struct chnl_net, list_field);
 136                 if (dev->state == CAIF_SHUTDOWN)
 137                         dev_close(dev->netdev);
 138         }
 139         rtnl_unlock();
 140 }
 141 static DECLARE_WORK(close_worker, close_work);
 142
 143 static void chnl_hold(struct cflayer *lyr)
 144 {
 145         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 146         dev_hold(priv->netdev);
 147 }
 148
 149 static void chnl_put(struct cflayer *lyr)
 150 {
 151         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 152         dev_put(priv->netdev);
 153 }
 154
 155 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
 156                              int phyid)
 157 {
 158         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
 159         pr_debug("NET flowctrl func called flow: %s\n",
 160                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
 161                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
 162                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
 163                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
 164                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
 165                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
 166                  "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
 167
 168
 169
 170         switch (flow) {
 171         case CAIF_CTRLCMD_FLOW_OFF_IND:
 172                 priv->flowenabled = false;
 173                 netif_stop_queue(priv->netdev);
 174                 break;
 175         case CAIF_CTRLCMD_DEINIT_RSP:
 176                 priv->state = CAIF_DISCONNECTED;
 177                 break;
 178         case CAIF_CTRLCMD_INIT_FAIL_RSP:
 179                 priv->state = CAIF_DISCONNECTED;
 180                 wake_up_interruptible(&priv->netmgmt_wq);
 181                 break;
 182         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
 183                 priv->state = CAIF_SHUTDOWN;
 184                 netif_tx_disable(priv->netdev);
 185                 schedule_work(&close_worker);
 186                 break;
 187         case CAIF_CTRLCMD_FLOW_ON_IND:
 188                 priv->flowenabled = true;
 189                 netif_wake_queue(priv->netdev);
 190                 break;
 191         case CAIF_CTRLCMD_INIT_RSP:
 192                 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
 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                 kfree_skb(skb);
 215                 dev->stats.tx_errors++;
 216                 return NETDEV_TX_OK;
 217         }
 218
 219         if (!priv->flowenabled) {
 220                 pr_debug("dropping packets flow off\n");
 221                 kfree_skb(skb);
 222                 dev->stats.tx_dropped++;
 223                 return NETDEV_TX_OK;
 224         }
 225
 226         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 227                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
 228
 229         /* Store original SKB length. */
 230         len = skb->len;
 231
 232         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
 233
 234         /* Send the packet down the stack. */
 235         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
 236         if (result) {
 237                 dev->stats.tx_dropped++;
 238                 return NETDEV_TX_OK;
 239         }
 240
 241         /* Update statistics. */
 242         dev->stats.tx_packets++;
 243         dev->stats.tx_bytes += len;
 244
 245         return NETDEV_TX_OK;
 246 }
 247
 248 static int chnl_net_open(struct net_device *dev)
 249 {
 250         struct chnl_net *priv = NULL;
 251         int result = -1;
 252         int llifindex, headroom, tailroom, mtu;
 253         struct net_device *lldev;
 254         ASSERT_RTNL();
 255         priv = netdev_priv(dev);
 256         if (!priv) {
 257                 pr_debug("chnl_net_open: no priv\n");
 258                 return -ENODEV;
 259         }
 260
 261         if (priv->state != CAIF_CONNECTING) {
 262                 priv->state = CAIF_CONNECTING;
 263                 result = caif_connect_client(dev_net(dev), &priv->conn_req,
 264                                                 &priv->chnl, &llifindex,
 265                                                 &headroom, &tailroom);
 266                 if (result != 0) {
 267                                 pr_debug("err: "
 268                                          "Unable to register and open device,"
 269                                          " Err:%d\n",
 270                                          result);
 271                                 goto error;
 272                 }
 273
 274                 lldev = __dev_get_by_index(dev_net(dev), llifindex);
 275
 276                 if (lldev == NULL) {
 277                         pr_debug("no interface?\n");
 278                         result = -ENODEV;
 279                         goto error;
 280                 }
 281
 282                 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
 283                 dev->hard_header_len = headroom + lldev->hard_header_len +
 284                         lldev->needed_tailroom;
 285
 286                 /*
 287                  * MTU, head-room etc is not know before we have a
 288                  * CAIF link layer device available. MTU calculation may
 289                  * override initial RTNL configuration.
 290                  * MTU is minimum of current mtu, link layer mtu pluss
 291                  * CAIF head and tail, and PDP GPRS contexts max MTU.
 292                  */
 293                 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
 294                 mtu = min_t(int, GPRS_PDP_MTU, mtu);
 295                 dev_set_mtu(dev, mtu);
 296
 297                 if (mtu < 100) {
 298                         pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
 299                         result = -ENODEV;
 300                         goto error;
 301                 }
 302         }
 303
 304         rtnl_unlock();  /* Release RTNL lock during connect wait */
 305
 306         result = wait_event_interruptible_timeout(priv->netmgmt_wq,
 307                                                 priv->state != CAIF_CONNECTING,
 308                                                 CONNECT_TIMEOUT);
 309
 310         rtnl_lock();
 311
 312         if (result == -ERESTARTSYS) {
 313                 pr_debug("wait_event_interruptible woken by a signal\n");
 314                 result = -ERESTARTSYS;
 315                 goto error;
 316         }
 317
 318         if (result == 0) {
 319                 pr_debug("connect timeout\n");
 320                 caif_disconnect_client(dev_net(dev), &priv->chnl);
 321                 priv->state = CAIF_DISCONNECTED;
 322                 pr_debug("state disconnected\n");
 323                 result = -ETIMEDOUT;
 324                 goto error;
 325         }
 326
 327         if (priv->state != CAIF_CONNECTED) {
 328                 pr_debug("connect failed\n");
 329                 result = -ECONNREFUSED;
 330                 goto error;
 331         }
 332         pr_debug("CAIF Netdevice connected\n");
 333         return 0;
 334
 335 error:
 336         caif_disconnect_client(dev_net(dev), &priv->chnl);
 337         priv->state = CAIF_DISCONNECTED;
 338         pr_debug("state disconnected\n");
 339         return result;
 340
 341 }
 342
 343 static int chnl_net_stop(struct net_device *dev)
 344 {
 345         struct chnl_net *priv;
 346
 347         ASSERT_RTNL();
 348         priv = netdev_priv(dev);
 349         priv->state = CAIF_DISCONNECTED;
 350         caif_disconnect_client(dev_net(dev), &priv->chnl);
 351         return 0;
 352 }
 353
 354 static int chnl_net_init(struct net_device *dev)
 355 {
 356         struct chnl_net *priv;
 357         ASSERT_RTNL();
 358         priv = netdev_priv(dev);
 359         strncpy(priv->name, dev->name, sizeof(priv->name));
 360         INIT_LIST_HEAD(&priv->list_field);
 361         return 0;
 362 }
 363
 364 static void chnl_net_uninit(struct net_device *dev)
 365 {
 366         struct chnl_net *priv;
 367         ASSERT_RTNL();
 368         priv = netdev_priv(dev);
 369         list_del_init(&priv->list_field);
 370 }
 371
 372 static const struct net_device_ops netdev_ops = {
 373         .ndo_open = chnl_net_open,
 374         .ndo_stop = chnl_net_stop,
 375         .ndo_init = chnl_net_init,
 376         .ndo_uninit = chnl_net_uninit,
 377         .ndo_start_xmit = chnl_net_start_xmit,
 378 };
 379
 380 static void chnl_net_destructor(struct net_device *dev)
 381 {
 382         struct chnl_net *priv = netdev_priv(dev);
 383         caif_free_client(&priv->chnl);
 384         free_netdev(dev);
 385 }
 386
 387 static void ipcaif_net_setup(struct net_device *dev)
 388 {
 389         struct chnl_net *priv;
 390         dev->netdev_ops = &netdev_ops;
 391         dev->destructor = chnl_net_destructor;
 392         dev->flags |= IFF_NOARP;
 393         dev->flags |= IFF_POINTOPOINT;
 394         dev->mtu = GPRS_PDP_MTU;
 395         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
 396
 397         priv = netdev_priv(dev);
 398         priv->chnl.receive = chnl_recv_cb;
 399         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
 400         priv->netdev = dev;
 401         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
 402         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
 403         priv->conn_req.priority = CAIF_PRIO_LOW;
 404         /* Insert illegal value */
 405         priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
 406         priv->flowenabled = false;
 407
 408         init_waitqueue_head(&priv->netmgmt_wq);
 409 }
 410
 411
 412 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
 413 {
 414         struct chnl_net *priv;
 415         u8 loop;
 416         priv = netdev_priv(dev);
 417         if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
 418                         priv->conn_req.sockaddr.u.dgm.connection_id) ||
 419             nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
 420                         priv->conn_req.sockaddr.u.dgm.connection_id))
 421                 goto nla_put_failure;
 422         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
 423         if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
 424                 goto nla_put_failure;
 425         return 0;
 426 nla_put_failure:
 427         return -EMSGSIZE;
 428
 429 }
 430
 431 static void caif_netlink_parms(struct nlattr *data[],
 432                                struct caif_connect_request *conn_req)
 433 {
 434         if (!data) {
 435                 pr_warn("no params data found\n");
 436                 return;
 437         }
 438         if (data[IFLA_CAIF_IPV4_CONNID])
 439                 conn_req->sockaddr.u.dgm.connection_id =
 440                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
 441         if (data[IFLA_CAIF_IPV6_CONNID])
 442                 conn_req->sockaddr.u.dgm.connection_id =
 443                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
 444         if (data[IFLA_CAIF_LOOPBACK]) {
 445                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
 446                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
 447                 else
 448                         conn_req->protocol = CAIFPROTO_DATAGRAM;
 449         }
 450 }
 451
 452 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
 453                           struct nlattr *tb[], struct nlattr *data[])
 454 {
 455         int ret;
 456         struct chnl_net *caifdev;
 457         ASSERT_RTNL();
 458         caifdev = netdev_priv(dev);
 459         caif_netlink_parms(data, &caifdev->conn_req);
 460
 461         ret = register_netdevice(dev);
 462         if (ret)
 463                 pr_warn("device rtml registration failed\n");
 464         else
 465                 list_add(&caifdev->list_field, &chnl_net_list);
 466
 467         /* Use ifindex as connection id, and use loopback channel default. */
 468         if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
 469                 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
 470                 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
 471         }
 472         return ret;
 473 }
 474
 475 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
 476                              struct nlattr *data[])
 477 {
 478         struct chnl_net *caifdev;
 479         ASSERT_RTNL();
 480         caifdev = netdev_priv(dev);
 481         caif_netlink_parms(data, &caifdev->conn_req);
 482         netdev_state_change(dev);
 483         return 0;
 484 }
 485
 486 static size_t ipcaif_get_size(const struct net_device *dev)
 487 {
 488         return
 489                 /* IFLA_CAIF_IPV4_CONNID */
 490                 nla_total_size(4) +
 491                 /* IFLA_CAIF_IPV6_CONNID */
 492                 nla_total_size(4) +
 493                 /* IFLA_CAIF_LOOPBACK */
 494                 nla_total_size(2) +
 495                 0;
 496 }
 497
 498 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
 499         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
 500         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
 501         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
 502 };
 503
 504
 505 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
 506         .kind           = "caif",
 507         .priv_size      = sizeof(struct chnl_net),
 508         .setup          = ipcaif_net_setup,
 509         .maxtype        = IFLA_CAIF_MAX,
 510         .policy         = ipcaif_policy,
 511         .newlink        = ipcaif_newlink,
 512         .changelink     = ipcaif_changelink,
 513         .get_size       = ipcaif_get_size,
 514         .fill_info      = ipcaif_fill_info,
 515
 516 };
 517
 518 static int __init chnl_init_module(void)
 519 {
 520         return rtnl_link_register(&ipcaif_link_ops);
 521 }
 522
 523 static void __exit chnl_exit_module(void)
 524 {
 525         struct chnl_net *dev = NULL;
 526         struct list_head *list_node;
 527         struct list_head *_tmp;
 528         rtnl_link_unregister(&ipcaif_link_ops);
 529         rtnl_lock();
 530         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 531                 dev = list_entry(list_node, struct chnl_net, list_field);
 532                 list_del_init(list_node);
 533                 delete_device(dev);
 534         }
 535         rtnl_unlock();
 536 }
 537
 538 module_init(chnl_init_module);
 539 module_exit(chnl_exit_module);