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 #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 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;
  77         int pktlen;
  78         const u8 *ip_version;
  79         u8 buf;
  80
  81         priv = container_of(layr, struct chnl_net, chnl);
  82         if (!priv)
  83                 return -EINVAL;
  84
  85         skb = (struct sk_buff *) cfpkt_tonative(pkt);
  86
  87         /* Get length of CAIF packet. */
  88         pktlen = skb->len;
  89
  90         /* Pass some minimum information and
  91          * send the packet to the net stack.
  92          */
  93         skb->dev = priv->netdev;
  94
  95         /* check the version of IP */
  96         ip_version = skb_header_pointer(skb, 0, 1, &buf);
  97
  98         switch (*ip_version >> 4) {
  99         case 4:
 100                 skb->protocol = htons(ETH_P_IP);
 101                 break;
 102         case 6:
 103                 skb->protocol = htons(ETH_P_IPV6);
 104                 break;
 105         default:
 106                 priv->netdev->stats.rx_errors++;
 107                 return -EINVAL;
 108         }
 109
 110         /* If we change the header in loop mode, the checksum is corrupted. */
 111         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 112                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 113         else
 114                 skb->ip_summed = CHECKSUM_NONE;
 115
 116         if (in_interrupt())
 117                 netif_rx(skb);
 118         else
 119                 netif_rx_ni(skb);
 120
 121         /* Update statistics. */
 122         priv->netdev->stats.rx_packets++;
 123         priv->netdev->stats.rx_bytes += pktlen;
 124
 125         return 0;
 126 }
 127
 128 static int delete_device(struct chnl_net *dev)
 129 {
 130         ASSERT_RTNL();
 131         if (dev->netdev)
 132                 unregister_netdevice(dev->netdev);
 133         return 0;
 134 }
 135
 136 static void close_work(struct work_struct *work)
 137 {
 138         struct chnl_net *dev = NULL;
 139         struct list_head *list_node;
 140         struct list_head *_tmp;
 141
 142         rtnl_lock();
 143         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 144                 dev = list_entry(list_node, struct chnl_net, list_field);
 145                 if (dev->state == CAIF_SHUTDOWN)
 146                         dev_close(dev->netdev);
 147         }
 148         rtnl_unlock();
 149 }
 150 static DECLARE_WORK(close_worker, close_work);
 151
 152 static void chnl_hold(struct cflayer *lyr)
 153 {
 154         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 155         dev_hold(priv->netdev);
 156 }
 157
 158 static void chnl_put(struct cflayer *lyr)
 159 {
 160         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 161         dev_put(priv->netdev);
 162 }
 163
 164 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
 165                                 int phyid)
 166 {
 167         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
 168         pr_debug("NET flowctrl func called flow: %s\n",
 169                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
 170                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
 171                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
 172                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
 173                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
 174                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
 175                  "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
 176
 177
 178
 179         switch (flow) {
 180         case CAIF_CTRLCMD_FLOW_OFF_IND:
 181                 priv->flowenabled = false;
 182                 netif_stop_queue(priv->netdev);
 183                 break;
 184         case CAIF_CTRLCMD_DEINIT_RSP:
 185                 priv->state = CAIF_DISCONNECTED;
 186                 break;
 187         case CAIF_CTRLCMD_INIT_FAIL_RSP:
 188                 priv->state = CAIF_DISCONNECTED;
 189                 wake_up_interruptible(&priv->netmgmt_wq);
 190                 break;
 191         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
 192                 priv->state = CAIF_SHUTDOWN;
 193                 netif_tx_disable(priv->netdev);
 194                 schedule_work(&close_worker);
 195                 break;
 196         case CAIF_CTRLCMD_FLOW_ON_IND:
 197                 priv->flowenabled = true;
 198                 netif_wake_queue(priv->netdev);
 199                 break;
 200         case CAIF_CTRLCMD_INIT_RSP:
 201                 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
 202                 priv->state = CAIF_CONNECTED;
 203                 priv->flowenabled = true;
 204                 netif_wake_queue(priv->netdev);
 205                 wake_up_interruptible(&priv->netmgmt_wq);
 206                 break;
 207         default:
 208                 break;
 209         }
 210 }
 211
 212 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 213 {
 214         struct chnl_net *priv;
 215         struct cfpkt *pkt = NULL;
 216         int len;
 217         int result = -1;
 218         /* Get our private data. */
 219         priv = netdev_priv(dev);
 220
 221         if (skb->len > priv->netdev->mtu) {
 222                 pr_warn("Size of skb exceeded MTU\n");
 223                 dev->stats.tx_errors++;
 224                 return -ENOSPC;
 225         }
 226
 227         if (!priv->flowenabled) {
 228                 pr_debug("dropping packets flow off\n");
 229                 dev->stats.tx_dropped++;
 230                 return NETDEV_TX_BUSY;
 231         }
 232
 233         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 234                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
 235
 236         /* Store original SKB length. */
 237         len = skb->len;
 238
 239         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
 240
 241         /* Send the packet down the stack. */
 242         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
 243         if (result) {
 244                 dev->stats.tx_dropped++;
 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 = UNDEF_CONNID;
 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         /* Use ifindex as connection id, and use loopback channel default. */
 476         if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
 477                 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
 478                 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
 479         }
 480         return ret;
 481 }
 482
 483 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
 484                                 struct nlattr *data[])
 485 {
 486         struct chnl_net *caifdev;
 487         ASSERT_RTNL();
 488         caifdev = netdev_priv(dev);
 489         caif_netlink_parms(data, &caifdev->conn_req);
 490         netdev_state_change(dev);
 491         return 0;
 492 }
 493
 494 static size_t ipcaif_get_size(const struct net_device *dev)
 495 {
 496         return
 497                 /* IFLA_CAIF_IPV4_CONNID */
 498                 nla_total_size(4) +
 499                 /* IFLA_CAIF_IPV6_CONNID */
 500                 nla_total_size(4) +
 501                 /* IFLA_CAIF_LOOPBACK */
 502                 nla_total_size(2) +
 503                 0;
 504 }
 505
 506 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
 507         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
 508         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
 509         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
 510 };
 511
 512
 513 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
 514         .kind           = "caif",
 515         .priv_size      = sizeof(struct chnl_net),
 516         .setup          = ipcaif_net_setup,
 517         .maxtype        = IFLA_CAIF_MAX,
 518         .policy         = ipcaif_policy,
 519         .newlink        = ipcaif_newlink,
 520         .changelink     = ipcaif_changelink,
 521         .get_size       = ipcaif_get_size,
 522         .fill_info      = ipcaif_fill_info,
 523
 524 };
 525
 526 static int __init chnl_init_module(void)
 527 {
 528         return rtnl_link_register(&ipcaif_link_ops);
 529 }
 530
 531 static void __exit chnl_exit_module(void)
 532 {
 533         struct chnl_net *dev = NULL;
 534         struct list_head *list_node;
 535         struct list_head *_tmp;
 536         rtnl_link_unregister(&ipcaif_link_ops);
 537         rtnl_lock();
 538         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 539                 dev = list_entry(list_node, struct chnl_net, list_field);
 540                 list_del(list_node);
 541                 delete_device(dev);
 542         }
 543         rtnl_unlock();
 544 }
 545
 546 module_init(chnl_init_module);
 547 module_exit(chnl_exit_module);