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