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/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
  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;
  76         int pktlen;
  77         const u8 *ip_version;
  78         u8 buf;
  79
  80         priv = container_of(layr, struct chnl_net, chnl);
  81         if (!priv)
  82                 return -EINVAL;
  83
  84         skb = (struct sk_buff *) cfpkt_tonative(pkt);
  85
  86         /* Get length of CAIF packet. */
  87         pktlen = skb->len;
  88
  89         /* Pass some minimum information and
  90          * send the packet to the net stack.
  91          */
  92         skb->dev = priv->netdev;
  93
  94         /* check the version of IP */
  95         ip_version = skb_header_pointer(skb, 0, 1, &buf);
  96
  97         switch (*ip_version >> 4) {
  98         case 4:
  99                 skb->protocol = htons(ETH_P_IP);
 100                 break;
 101         case 6:
 102                 skb->protocol = htons(ETH_P_IPV6);
 103                 break;
 104         default:
 105                 priv->netdev->stats.rx_errors++;
 106                 return -EINVAL;
 107         }
 108
 109         /* If we change the header in loop mode, the checksum is corrupted. */
 110         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 111                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 112         else
 113                 skb->ip_summed = CHECKSUM_NONE;
 114
 115         if (in_interrupt())
 116                 netif_rx(skb);
 117         else
 118                 netif_rx_ni(skb);
 119
 120         /* Update statistics. */
 121         priv->netdev->stats.rx_packets++;
 122         priv->netdev->stats.rx_bytes += pktlen;
 123
 124         return 0;
 125 }
 126
 127 static int delete_device(struct chnl_net *dev)
 128 {
 129         ASSERT_RTNL();
 130         if (dev->netdev)
 131                 unregister_netdevice(dev->netdev);
 132         return 0;
 133 }
 134
 135 static void close_work(struct work_struct *work)
 136 {
 137         struct chnl_net *dev = NULL;
 138         struct list_head *list_node;
 139         struct list_head *_tmp;
 140
 141         rtnl_lock();
 142         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 143                 dev = list_entry(list_node, struct chnl_net, list_field);
 144                 if (dev->state == CAIF_SHUTDOWN)
 145                         dev_close(dev->netdev);
 146         }
 147         rtnl_unlock();
 148 }
 149 static DECLARE_WORK(close_worker, close_work);
 150
 151 static void chnl_hold(struct cflayer *lyr)
 152 {
 153         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 154         dev_hold(priv->netdev);
 155 }
 156
 157 static void chnl_put(struct cflayer *lyr)
 158 {
 159         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 160         dev_put(priv->netdev);
 161 }
 162
 163 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
 164                                 int phyid)
 165 {
 166         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
 167         pr_debug("NET flowctrl func called flow: %s\n",
 168                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
 169                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
 170                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
 171                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
 172                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
 173                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
 174                  "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
 175
 176
 177
 178         switch (flow) {
 179         case CAIF_CTRLCMD_FLOW_OFF_IND:
 180                 priv->flowenabled = false;
 181                 netif_stop_queue(priv->netdev);
 182                 break;
 183         case CAIF_CTRLCMD_DEINIT_RSP:
 184                 priv->state = CAIF_DISCONNECTED;
 185                 break;
 186         case CAIF_CTRLCMD_INIT_FAIL_RSP:
 187                 priv->state = CAIF_DISCONNECTED;
 188                 wake_up_interruptible(&priv->netmgmt_wq);
 189                 break;
 190         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
 191                 priv->state = CAIF_SHUTDOWN;
 192                 netif_tx_disable(priv->netdev);
 193                 schedule_work(&close_worker);
 194                 break;
 195         case CAIF_CTRLCMD_FLOW_ON_IND:
 196                 priv->flowenabled = true;
 197                 netif_wake_queue(priv->netdev);
 198                 break;
 199         case CAIF_CTRLCMD_INIT_RSP:
 200                 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
 201                 priv->state = CAIF_CONNECTED;
 202                 priv->flowenabled = true;
 203                 netif_wake_queue(priv->netdev);
 204                 wake_up_interruptible(&priv->netmgmt_wq);
 205                 break;
 206         default:
 207                 break;
 208         }
 209 }
 210
 211 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 212 {
 213         struct chnl_net *priv;
 214         struct cfpkt *pkt = NULL;
 215         int len;
 216         int result = -1;
 217         /* Get our private data. */
 218         priv = netdev_priv(dev);
 219
 220         if (skb->len > priv->netdev->mtu) {
 221                 pr_warn("Size of skb exceeded MTU\n");
 222                 dev->stats.tx_errors++;
 223                 return -ENOSPC;
 224         }
 225
 226         if (!priv->flowenabled) {
 227                 pr_debug("dropping packets flow off\n");
 228                 dev->stats.tx_dropped++;
 229                 return NETDEV_TX_BUSY;
 230         }
 231
 232         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 233                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
 234
 235         /* Store original SKB length. */
 236         len = skb->len;
 237
 238         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
 239
 240         /* Send the packet down the stack. */
 241         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
 242         if (result) {
 243                 dev->stats.tx_dropped++;
 244                 return result;
 245         }
 246
 247         /* Update statistics. */
 248         dev->stats.tx_packets++;
 249         dev->stats.tx_bytes += len;
 250
 251         return NETDEV_TX_OK;
 252 }
 253
 254 static int chnl_net_open(struct net_device *dev)
 255 {
 256         struct chnl_net *priv = NULL;
 257         int result = -1;
 258         int llifindex, headroom, tailroom, mtu;
 259         struct net_device *lldev;
 260         ASSERT_RTNL();
 261         priv = netdev_priv(dev);
 262         if (!priv) {
 263                 pr_debug("chnl_net_open: no priv\n");
 264                 return -ENODEV;
 265         }
 266
 267         if (priv->state != CAIF_CONNECTING) {
 268                 priv->state = CAIF_CONNECTING;
 269                 result = caif_connect_client(dev_net(dev), &priv->conn_req,
 270                                                 &priv->chnl, &llifindex,
 271                                                 &headroom, &tailroom);
 272                 if (result != 0) {
 273                                 pr_debug("err: "
 274                                          "Unable to register and open device,"
 275                                          " Err:%d\n",
 276                                          result);
 277                                 goto error;
 278                 }
 279
 280                 lldev = dev_get_by_index(dev_net(dev), llifindex);
 281
 282                 if (lldev == NULL) {
 283                         pr_debug("no interface?\n");
 284                         result = -ENODEV;
 285                         goto error;
 286                 }
 287
 288                 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
 289                 dev->hard_header_len = headroom + lldev->hard_header_len +
 290                         lldev->needed_tailroom;
 291
 292                 /*
 293                  * MTU, head-room etc is not know before we have a
 294                  * CAIF link layer device available. MTU calculation may
 295                  * override initial RTNL configuration.
 296                  * MTU is minimum of current mtu, link layer mtu pluss
 297                  * CAIF head and tail, and PDP GPRS contexts max MTU.
 298                  */
 299                 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
 300                 mtu = min_t(int, GPRS_PDP_MTU, mtu);
 301                 dev_set_mtu(dev, mtu);
 302                 dev_put(lldev);
 303
 304                 if (mtu < 100) {
 305                         pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
 306                         result = -ENODEV;
 307                         goto error;
 308                 }
 309         }
 310
 311         rtnl_unlock();  /* Release RTNL lock during connect wait */
 312
 313         result = wait_event_interruptible_timeout(priv->netmgmt_wq,
 314                                                 priv->state != CAIF_CONNECTING,
 315                                                 CONNECT_TIMEOUT);
 316
 317         rtnl_lock();
 318
 319         if (result == -ERESTARTSYS) {
 320                 pr_debug("wait_event_interruptible woken by a signal\n");
 321                 result = -ERESTARTSYS;
 322                 goto error;
 323         }
 324
 325         if (result == 0) {
 326                 pr_debug("connect timeout\n");
 327                 caif_disconnect_client(dev_net(dev), &priv->chnl);
 328                 priv->state = CAIF_DISCONNECTED;
 329                 pr_debug("state disconnected\n");
 330                 result = -ETIMEDOUT;
 331                 goto error;
 332         }
 333
 334         if (priv->state != CAIF_CONNECTED) {
 335                 pr_debug("connect failed\n");
 336                 result = -ECONNREFUSED;
 337                 goto error;
 338         }
 339         pr_debug("CAIF Netdevice connected\n");
 340         return 0;
 341
 342 error:
 343         caif_disconnect_client(dev_net(dev), &priv->chnl);
 344         priv->state = CAIF_DISCONNECTED;
 345         pr_debug("state disconnected\n");
 346         return result;
 347
 348 }
 349
 350 static int chnl_net_stop(struct net_device *dev)
 351 {
 352         struct chnl_net *priv;
 353
 354         ASSERT_RTNL();
 355         priv = netdev_priv(dev);
 356         priv->state = CAIF_DISCONNECTED;
 357         caif_disconnect_client(dev_net(dev), &priv->chnl);
 358         return 0;
 359 }
 360
 361 static int chnl_net_init(struct net_device *dev)
 362 {
 363         struct chnl_net *priv;
 364         ASSERT_RTNL();
 365         priv = netdev_priv(dev);
 366         strncpy(priv->name, dev->name, sizeof(priv->name));
 367         return 0;
 368 }
 369
 370 static void chnl_net_uninit(struct net_device *dev)
 371 {
 372         struct chnl_net *priv;
 373         ASSERT_RTNL();
 374         priv = netdev_priv(dev);
 375         robust_list_del(&priv->list_field);
 376 }
 377
 378 static const struct net_device_ops netdev_ops = {
 379         .ndo_open = chnl_net_open,
 380         .ndo_stop = chnl_net_stop,
 381         .ndo_init = chnl_net_init,
 382         .ndo_uninit = chnl_net_uninit,
 383         .ndo_start_xmit = chnl_net_start_xmit,
 384 };
 385
 386 static void chnl_net_destructor(struct net_device *dev)
 387 {
 388         struct chnl_net *priv = netdev_priv(dev);
 389         caif_free_client(&priv->chnl);
 390         free_netdev(dev);
 391 }
 392
 393 static void ipcaif_net_setup(struct net_device *dev)
 394 {
 395         struct chnl_net *priv;
 396         dev->netdev_ops = &netdev_ops;
 397         dev->destructor = chnl_net_destructor;
 398         dev->flags |= IFF_NOARP;
 399         dev->flags |= IFF_POINTOPOINT;
 400         dev->mtu = GPRS_PDP_MTU;
 401         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
 402
 403         priv = netdev_priv(dev);
 404         priv->chnl.receive = chnl_recv_cb;
 405         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
 406         priv->netdev = dev;
 407         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
 408         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
 409         priv->conn_req.priority = CAIF_PRIO_LOW;
 410         /* Insert illegal value */
 411         priv->conn_req.sockaddr.u.dgm.connection_id = 0;
 412         priv->flowenabled = false;
 413
 414         init_waitqueue_head(&priv->netmgmt_wq);
 415 }
 416
 417
 418 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
 419 {
 420         struct chnl_net *priv;
 421         u8 loop;
 422         priv = netdev_priv(dev);
 423         NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID,
 424                     priv->conn_req.sockaddr.u.dgm.connection_id);
 425         NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID,
 426                     priv->conn_req.sockaddr.u.dgm.connection_id);
 427         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
 428         NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop);
 429
 430
 431         return 0;
 432 nla_put_failure:
 433         return -EMSGSIZE;
 434
 435 }
 436
 437 static void caif_netlink_parms(struct nlattr *data[],
 438                                 struct caif_connect_request *conn_req)
 439 {
 440         if (!data) {
 441                 pr_warn("no params data found\n");
 442                 return;
 443         }
 444         if (data[IFLA_CAIF_IPV4_CONNID])
 445                 conn_req->sockaddr.u.dgm.connection_id =
 446                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
 447         if (data[IFLA_CAIF_IPV6_CONNID])
 448                 conn_req->sockaddr.u.dgm.connection_id =
 449                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
 450         if (data[IFLA_CAIF_LOOPBACK]) {
 451                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
 452                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
 453                 else
 454                         conn_req->protocol = CAIFPROTO_DATAGRAM;
 455         }
 456 }
 457
 458 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
 459                           struct nlattr *tb[], struct nlattr *data[])
 460 {
 461         int ret;
 462         struct chnl_net *caifdev;
 463         ASSERT_RTNL();
 464         caifdev = netdev_priv(dev);
 465         caif_netlink_parms(data, &caifdev->conn_req);
 466         dev_net_set(caifdev->netdev, src_net);
 467
 468         ret = register_netdevice(dev);
 469         if (ret)
 470                 pr_warn("device rtml registration failed\n");
 471         else
 472                 list_add(&caifdev->list_field, &chnl_net_list);
 473
 474         /* Take ifindex as connection-id if null */
 475         if (caifdev->conn_req.sockaddr.u.dgm.connection_id == 0)
 476                 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
 477         return ret;
 478 }
 479
 480 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
 481                                 struct nlattr *data[])
 482 {
 483         struct chnl_net *caifdev;
 484         ASSERT_RTNL();
 485         caifdev = netdev_priv(dev);
 486         caif_netlink_parms(data, &caifdev->conn_req);
 487         netdev_state_change(dev);
 488         return 0;
 489 }
 490
 491 static size_t ipcaif_get_size(const struct net_device *dev)
 492 {
 493         return
 494                 /* IFLA_CAIF_IPV4_CONNID */
 495                 nla_total_size(4) +
 496                 /* IFLA_CAIF_IPV6_CONNID */
 497                 nla_total_size(4) +
 498                 /* IFLA_CAIF_LOOPBACK */
 499                 nla_total_size(2) +
 500                 0;
 501 }
 502
 503 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
 504         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
 505         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
 506         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
 507 };
 508
 509
 510 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
 511         .kind           = "caif",
 512         .priv_size      = sizeof(struct chnl_net),
 513         .setup          = ipcaif_net_setup,
 514         .maxtype        = IFLA_CAIF_MAX,
 515         .policy         = ipcaif_policy,
 516         .newlink        = ipcaif_newlink,
 517         .changelink     = ipcaif_changelink,
 518         .get_size       = ipcaif_get_size,
 519         .fill_info      = ipcaif_fill_info,
 520
 521 };
 522
 523 static int __init chnl_init_module(void)
 524 {
 525         return rtnl_link_register(&ipcaif_link_ops);
 526 }
 527
 528 static void __exit chnl_exit_module(void)
 529 {
 530         struct chnl_net *dev = NULL;
 531         struct list_head *list_node;
 532         struct list_head *_tmp;
 533         rtnl_link_unregister(&ipcaif_link_ops);
 534         rtnl_lock();
 535         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 536                 dev = list_entry(list_node, struct chnl_net, list_field);
 537                 list_del(list_node);
 538                 delete_device(dev);
 539         }
 540         rtnl_unlock();
 541 }
 542
 543 module_init(chnl_init_module);
 544 module_exit(chnl_exit_module);