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/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         const u8 *ip_version;
  80         u8 buf;
  81
  82         priv = container_of(layr, struct chnl_net, chnl);
  83
  84         if (!priv)
  85                 return -EINVAL;
  86
  87         /* Get length of CAIF packet. */
  88         pktlen = cfpkt_getlen(pkt);
  89
  90         skb = (struct sk_buff *) cfpkt_tonative(pkt);
  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_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
 157                                 int phyid)
 158 {
 159         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
 160         pr_debug("NET flowctrl func called flow: %s\n",
 161                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
 162                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
 163                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
 164                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
 165                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
 166                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
 167                  "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
 168
 169
 170
 171         switch (flow) {
 172         case CAIF_CTRLCMD_FLOW_OFF_IND:
 173                 priv->flowenabled = false;
 174                 netif_stop_queue(priv->netdev);
 175                 break;
 176         case CAIF_CTRLCMD_DEINIT_RSP:
 177                 priv->state = CAIF_DISCONNECTED;
 178                 break;
 179         case CAIF_CTRLCMD_INIT_FAIL_RSP:
 180                 priv->state = CAIF_DISCONNECTED;
 181                 wake_up_interruptible(&priv->netmgmt_wq);
 182                 break;
 183         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
 184                 priv->state = CAIF_SHUTDOWN;
 185                 netif_tx_disable(priv->netdev);
 186                 schedule_work(&close_worker);
 187                 break;
 188         case CAIF_CTRLCMD_FLOW_ON_IND:
 189                 priv->flowenabled = true;
 190                 netif_wake_queue(priv->netdev);
 191                 break;
 192         case CAIF_CTRLCMD_INIT_RSP:
 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                 return -ENOSPC;
 215         }
 216
 217         if (!priv->flowenabled) {
 218                 pr_debug("dropping packets flow off\n");
 219                 return NETDEV_TX_BUSY;
 220         }
 221
 222         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 223                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
 224
 225         /* Store original SKB length. */
 226         len = skb->len;
 227
 228         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
 229
 230         /* Send the packet down the stack. */
 231         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
 232         if (result) {
 233                 if (result == -EAGAIN)
 234                         result = NETDEV_TX_BUSY;
 235                 return result;
 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(&priv->conn_req, &priv->chnl,
 261                                         &llifindex, &headroom, &tailroom);
 262                 if (result != 0) {
 263                                 pr_debug("err: "
 264                                          "Unable to register and open device,"
 265                                          " Err:%d\n",
 266                                          result);
 267                                 goto error;
 268                 }
 269
 270                 lldev = dev_get_by_index(dev_net(dev), llifindex);
 271
 272                 if (lldev == NULL) {
 273                         pr_debug("no interface?\n");
 274                         result = -ENODEV;
 275                         goto error;
 276                 }
 277
 278                 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
 279                 dev->hard_header_len = headroom + lldev->hard_header_len +
 280                         lldev->needed_tailroom;
 281
 282                 /*
 283                  * MTU, head-room etc is not know before we have a
 284                  * CAIF link layer device available. MTU calculation may
 285                  * override initial RTNL configuration.
 286                  * MTU is minimum of current mtu, link layer mtu pluss
 287                  * CAIF head and tail, and PDP GPRS contexts max MTU.
 288                  */
 289                 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
 290                 mtu = min_t(int, GPRS_PDP_MTU, mtu);
 291                 dev_set_mtu(dev, mtu);
 292                 dev_put(lldev);
 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(&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(&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(&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         return 0;
 358 }
 359
 360 static void chnl_net_uninit(struct net_device *dev)
 361 {
 362         struct chnl_net *priv;
 363         ASSERT_RTNL();
 364         priv = netdev_priv(dev);
 365         robust_list_del(&priv->list_field);
 366 }
 367
 368 static const struct net_device_ops netdev_ops = {
 369         .ndo_open = chnl_net_open,
 370         .ndo_stop = chnl_net_stop,
 371         .ndo_init = chnl_net_init,
 372         .ndo_uninit = chnl_net_uninit,
 373         .ndo_start_xmit = chnl_net_start_xmit,
 374 };
 375
 376 static void ipcaif_net_setup(struct net_device *dev)
 377 {
 378         struct chnl_net *priv;
 379         dev->netdev_ops = &netdev_ops;
 380         dev->destructor = free_netdev;
 381         dev->flags |= IFF_NOARP;
 382         dev->flags |= IFF_POINTOPOINT;
 383         dev->mtu = GPRS_PDP_MTU;
 384         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
 385
 386         priv = netdev_priv(dev);
 387         priv->chnl.receive = chnl_recv_cb;
 388         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
 389         priv->netdev = dev;
 390         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
 391         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
 392         priv->conn_req.priority = CAIF_PRIO_LOW;
 393         /* Insert illegal value */
 394         priv->conn_req.sockaddr.u.dgm.connection_id = -1;
 395         priv->flowenabled = false;
 396
 397         init_waitqueue_head(&priv->netmgmt_wq);
 398 }
 399
 400
 401 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
 402 {
 403         struct chnl_net *priv;
 404         u8 loop;
 405         priv = netdev_priv(dev);
 406         NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID,
 407                     priv->conn_req.sockaddr.u.dgm.connection_id);
 408         NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID,
 409                     priv->conn_req.sockaddr.u.dgm.connection_id);
 410         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
 411         NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop);
 412
 413
 414         return 0;
 415 nla_put_failure:
 416         return -EMSGSIZE;
 417
 418 }
 419
 420 static void caif_netlink_parms(struct nlattr *data[],
 421                                 struct caif_connect_request *conn_req)
 422 {
 423         if (!data) {
 424                 pr_warn("no params data found\n");
 425                 return;
 426         }
 427         if (data[IFLA_CAIF_IPV4_CONNID])
 428                 conn_req->sockaddr.u.dgm.connection_id =
 429                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
 430         if (data[IFLA_CAIF_IPV6_CONNID])
 431                 conn_req->sockaddr.u.dgm.connection_id =
 432                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
 433         if (data[IFLA_CAIF_LOOPBACK]) {
 434                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
 435                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
 436                 else
 437                         conn_req->protocol = CAIFPROTO_DATAGRAM;
 438         }
 439 }
 440
 441 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
 442                           struct nlattr *tb[], struct nlattr *data[])
 443 {
 444         int ret;
 445         struct chnl_net *caifdev;
 446         ASSERT_RTNL();
 447         caifdev = netdev_priv(dev);
 448         caif_netlink_parms(data, &caifdev->conn_req);
 449         dev_net_set(caifdev->netdev, src_net);
 450
 451         ret = register_netdevice(dev);
 452         if (ret)
 453                 pr_warn("device rtml registration failed\n");
 454         else
 455                 list_add(&caifdev->list_field, &chnl_net_list);
 456         return ret;
 457 }
 458
 459 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
 460                                 struct nlattr *data[])
 461 {
 462         struct chnl_net *caifdev;
 463         ASSERT_RTNL();
 464         caifdev = netdev_priv(dev);
 465         caif_netlink_parms(data, &caifdev->conn_req);
 466         netdev_state_change(dev);
 467         return 0;
 468 }
 469
 470 static size_t ipcaif_get_size(const struct net_device *dev)
 471 {
 472         return
 473                 /* IFLA_CAIF_IPV4_CONNID */
 474                 nla_total_size(4) +
 475                 /* IFLA_CAIF_IPV6_CONNID */
 476                 nla_total_size(4) +
 477                 /* IFLA_CAIF_LOOPBACK */
 478                 nla_total_size(2) +
 479                 0;
 480 }
 481
 482 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
 483         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
 484         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
 485         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
 486 };
 487
 488
 489 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
 490         .kind           = "caif",
 491         .priv_size      = sizeof(struct chnl_net),
 492         .setup          = ipcaif_net_setup,
 493         .maxtype        = IFLA_CAIF_MAX,
 494         .policy         = ipcaif_policy,
 495         .newlink        = ipcaif_newlink,
 496         .changelink     = ipcaif_changelink,
 497         .get_size       = ipcaif_get_size,
 498         .fill_info      = ipcaif_fill_info,
 499
 500 };
 501
 502 static int __init chnl_init_module(void)
 503 {
 504         return rtnl_link_register(&ipcaif_link_ops);
 505 }
 506
 507 static void __exit chnl_exit_module(void)
 508 {
 509         struct chnl_net *dev = NULL;
 510         struct list_head *list_node;
 511         struct list_head *_tmp;
 512         rtnl_link_unregister(&ipcaif_link_ops);
 513         rtnl_lock();
 514         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 515                 dev = list_entry(list_node, struct chnl_net, list_field);
 516                 list_del(list_node);
 517                 delete_device(dev);
 518         }
 519         rtnl_unlock();
 520 }
 521
 522 module_init(chnl_init_module);
 523 module_exit(chnl_exit_module);