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