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 #include <linux/version.h>
   9 #include <linux/fs.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/if_ether.h>
  14 #include <linux/moduleparam.h>
  15 #include <linux/ip.h>
  16 #include <linux/sched.h>
  17 #include <linux/sockios.h>
  18 #include <linux/caif/if_caif.h>
  19 #include <net/rtnetlink.h>
  20 #include <net/caif/caif_layer.h>
  21 #include <net/caif/cfcnfg.h>
  22 #include <net/caif/cfpkt.h>
  23 #include <net/caif/caif_dev.h>
  24
  25 /* GPRS PDP connection has MTU to 1500 */
  26 #define GPRS_PDP_MTU 1500
  27 /* 5 sec. connect timeout */
  28 #define CONNECT_TIMEOUT (5 * HZ)
  29 #define CAIF_NET_DEFAULT_QUEUE_LEN 500
  30
  31 #undef pr_debug
  32 #define pr_debug pr_warning
  33
  34 /*This list is protected by the rtnl lock. */
  35 static LIST_HEAD(chnl_net_list);
  36
  37 MODULE_LICENSE("GPL");
  38 MODULE_ALIAS_RTNL_LINK("caif");
  39
  40 enum caif_states {
  41         CAIF_CONNECTED          = 1,
  42         CAIF_CONNECTING,
  43         CAIF_DISCONNECTED,
  44         CAIF_SHUTDOWN
  45 };
  46
  47 struct chnl_net {
  48         struct cflayer chnl;
  49         struct net_device_stats stats;
  50         struct caif_connect_request conn_req;
  51         struct list_head list_field;
  52         struct net_device *netdev;
  53         char name[256];
  54         wait_queue_head_t netmgmt_wq;
  55         /* Flow status to remember and control the transmission. */
  56         bool flowenabled;
  57         enum caif_states state;
  58 };
  59
  60 static void robust_list_del(struct list_head *delete_node)
  61 {
  62         struct list_head *list_node;
  63         struct list_head *n;
  64         ASSERT_RTNL();
  65         list_for_each_safe(list_node, n, &chnl_net_list) {
  66                 if (list_node == delete_node) {
  67                         list_del(list_node);
  68                         return;
  69                 }
  70         }
  71         WARN_ON(1);
  72 }
  73
  74 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
  75 {
  76         struct sk_buff *skb;
  77         struct chnl_net *priv  = container_of(layr, struct chnl_net, chnl);
  78         int pktlen;
  79         int err = 0;
  80
  81         priv = container_of(layr, struct chnl_net, chnl);
  82
  83         if (!priv)
  84                 return -EINVAL;
  85
  86         /* Get length of CAIF packet. */
  87         pktlen = cfpkt_getlen(pkt);
  88
  89         skb = (struct sk_buff *) cfpkt_tonative(pkt);
  90         /* Pass some minimum information and
  91          * send the packet to the net stack.
  92          */
  93         skb->dev = priv->netdev;
  94         skb->protocol = htons(ETH_P_IP);
  95
  96         /* If we change the header in loop mode, the checksum is corrupted. */
  97         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
  98                 skb->ip_summed = CHECKSUM_UNNECESSARY;
  99         else
 100                 skb->ip_summed = CHECKSUM_NONE;
 101
 102         if (in_interrupt())
 103                 netif_rx(skb);
 104         else
 105                 netif_rx_ni(skb);
 106
 107         /* Update statistics. */
 108         priv->netdev->stats.rx_packets++;
 109         priv->netdev->stats.rx_bytes += pktlen;
 110
 111         return err;
 112 }
 113
 114 static int delete_device(struct chnl_net *dev)
 115 {
 116         ASSERT_RTNL();
 117         if (dev->netdev)
 118                 unregister_netdevice(dev->netdev);
 119         return 0;
 120 }
 121
 122 static void close_work(struct work_struct *work)
 123 {
 124         struct chnl_net *dev = NULL;
 125         struct list_head *list_node;
 126         struct list_head *_tmp;
 127         /* May be called with or without RTNL lock held */
 128         int islocked = rtnl_is_locked();
 129         if (!islocked)
 130                 rtnl_lock();
 131         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 132                 dev = list_entry(list_node, struct chnl_net, list_field);
 133                 if (dev->state == CAIF_SHUTDOWN)
 134                         dev_close(dev->netdev);
 135         }
 136         if (!islocked)
 137                 rtnl_unlock();
 138 }
 139 static DECLARE_WORK(close_worker, close_work);
 140
 141 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
 142                                 int phyid)
 143 {
 144         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
 145         pr_debug("CAIF: %s(): NET flowctrl func called flow: %s\n",
 146                 __func__,
 147                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
 148                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
 149                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
 150                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
 151                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
 152                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
 153                  "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
 154
 155
 156
 157         switch (flow) {
 158         case CAIF_CTRLCMD_FLOW_OFF_IND:
 159                 priv->flowenabled = false;
 160                 netif_stop_queue(priv->netdev);
 161                 break;
 162         case CAIF_CTRLCMD_DEINIT_RSP:
 163                 priv->state = CAIF_DISCONNECTED;
 164                 break;
 165         case CAIF_CTRLCMD_INIT_FAIL_RSP:
 166                 priv->state = CAIF_DISCONNECTED;
 167                 wake_up_interruptible(&priv->netmgmt_wq);
 168                 break;
 169         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
 170                 priv->state = CAIF_SHUTDOWN;
 171                 netif_tx_disable(priv->netdev);
 172                 schedule_work(&close_worker);
 173                 break;
 174         case CAIF_CTRLCMD_FLOW_ON_IND:
 175                 priv->flowenabled = true;
 176                 netif_wake_queue(priv->netdev);
 177                 break;
 178         case CAIF_CTRLCMD_INIT_RSP:
 179                 priv->state = CAIF_CONNECTED;
 180                 priv->flowenabled = true;
 181                 netif_wake_queue(priv->netdev);
 182                 wake_up_interruptible(&priv->netmgmt_wq);
 183                 break;
 184         default:
 185                 break;
 186         }
 187 }
 188
 189 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 190 {
 191         struct chnl_net *priv;
 192         struct cfpkt *pkt = NULL;
 193         int len;
 194         int result = -1;
 195         /* Get our private data. */
 196         priv = netdev_priv(dev);
 197
 198         if (skb->len > priv->netdev->mtu) {
 199                 pr_warning("CAIF: %s(): Size of skb exceeded MTU\n", __func__);
 200                 return -ENOSPC;
 201         }
 202
 203         if (!priv->flowenabled) {
 204                 pr_debug("CAIF: %s(): dropping packets flow off\n", __func__);
 205                 return NETDEV_TX_BUSY;
 206         }
 207
 208         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 209                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
 210
 211         /* Store original SKB length. */
 212         len = skb->len;
 213
 214         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
 215
 216         /* Send the packet down the stack. */
 217         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
 218         if (result) {
 219                 if (result == -EAGAIN)
 220                         result = NETDEV_TX_BUSY;
 221                 return result;
 222         }
 223
 224         /* Update statistics. */
 225         dev->stats.tx_packets++;
 226         dev->stats.tx_bytes += len;
 227
 228         return NETDEV_TX_OK;
 229 }
 230
 231 static int chnl_net_open(struct net_device *dev)
 232 {
 233         struct chnl_net *priv = NULL;
 234         int result = -1;
 235         int llifindex, headroom, tailroom, mtu;
 236         struct net_device *lldev;
 237         ASSERT_RTNL();
 238         priv = netdev_priv(dev);
 239         if (!priv) {
 240                 pr_debug("CAIF: %s(): chnl_net_open: no priv\n", __func__);
 241                 return -ENODEV;
 242         }
 243
 244         if (priv->state != CAIF_CONNECTING) {
 245                 priv->state = CAIF_CONNECTING;
 246                 result = caif_connect_client(&priv->conn_req, &priv->chnl,
 247                                         &llifindex, &headroom, &tailroom);
 248                 if (result != 0) {
 249                                 pr_debug("CAIF: %s(): err: "
 250                                         "Unable to register and open device,"
 251                                         " Err:%d\n",
 252                                         __func__,
 253                                         result);
 254                                 goto error;
 255                 }
 256
 257                 lldev = dev_get_by_index(dev_net(dev), llifindex);
 258
 259                 if (lldev == NULL) {
 260                         pr_debug("CAIF: %s(): no interface?\n", __func__);
 261                         result = -ENODEV;
 262                         goto error;
 263                 }
 264
 265                 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
 266                 dev->hard_header_len = headroom + lldev->hard_header_len +
 267                         lldev->needed_tailroom;
 268
 269                 /*
 270                  * MTU, head-room etc is not know before we have a
 271                  * CAIF link layer device available. MTU calculation may
 272                  * override initial RTNL configuration.
 273                  * MTU is minimum of current mtu, link layer mtu pluss
 274                  * CAIF head and tail, and PDP GPRS contexts max MTU.
 275                  */
 276                 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
 277                 mtu = min_t(int, GPRS_PDP_MTU, mtu);
 278                 dev_set_mtu(dev, mtu);
 279                 dev_put(lldev);
 280
 281                 if (mtu < 100) {
 282                         pr_warning("CAIF: %s(): "
 283                                 "CAIF Interface MTU too small (%d)\n",
 284                                 __func__, mtu);
 285                         result = -ENODEV;
 286                         goto error;
 287                 }
 288         }
 289
 290         rtnl_unlock();  /* Release RTNL lock during connect wait */
 291
 292         result = wait_event_interruptible_timeout(priv->netmgmt_wq,
 293                                                 priv->state != CAIF_CONNECTING,
 294                                                 CONNECT_TIMEOUT);
 295
 296         rtnl_lock();
 297
 298         if (result == -ERESTARTSYS) {
 299                 pr_debug("CAIF: %s(): wait_event_interruptible"
 300                          " woken by a signal\n", __func__);
 301                 result = -ERESTARTSYS;
 302                 goto error;
 303         }
 304
 305         if (result == 0) {
 306                 pr_debug("CAIF: %s(): connect timeout\n", __func__);
 307                 caif_disconnect_client(&priv->chnl);
 308                 priv->state = CAIF_DISCONNECTED;
 309                 pr_debug("CAIF: %s(): state disconnected\n", __func__);
 310                 result = -ETIMEDOUT;
 311                 goto error;
 312         }
 313
 314         if (priv->state != CAIF_CONNECTED) {
 315                 pr_debug("CAIF: %s(): connect failed\n", __func__);
 316                 result = -ECONNREFUSED;
 317                 goto error;
 318         }
 319         pr_debug("CAIF: %s(): CAIF Netdevice connected\n", __func__);
 320         return 0;
 321
 322 error:
 323         caif_disconnect_client(&priv->chnl);
 324         priv->state = CAIF_DISCONNECTED;
 325         pr_debug("CAIF: %s(): state disconnected\n", __func__);
 326         return result;
 327
 328 }
 329
 330 static int chnl_net_stop(struct net_device *dev)
 331 {
 332         struct chnl_net *priv;
 333
 334         ASSERT_RTNL();
 335         priv = netdev_priv(dev);
 336         priv->state = CAIF_DISCONNECTED;
 337         caif_disconnect_client(&priv->chnl);
 338         return 0;
 339 }
 340
 341 static int chnl_net_init(struct net_device *dev)
 342 {
 343         struct chnl_net *priv;
 344         ASSERT_RTNL();
 345         priv = netdev_priv(dev);
 346         strncpy(priv->name, dev->name, sizeof(priv->name));
 347         return 0;
 348 }
 349
 350 static void chnl_net_uninit(struct net_device *dev)
 351 {
 352         struct chnl_net *priv;
 353         ASSERT_RTNL();
 354         priv = netdev_priv(dev);
 355         robust_list_del(&priv->list_field);
 356 }
 357
 358 static const struct net_device_ops netdev_ops = {
 359         .ndo_open = chnl_net_open,
 360         .ndo_stop = chnl_net_stop,
 361         .ndo_init = chnl_net_init,
 362         .ndo_uninit = chnl_net_uninit,
 363         .ndo_start_xmit = chnl_net_start_xmit,
 364 };
 365
 366 static void ipcaif_net_setup(struct net_device *dev)
 367 {
 368         struct chnl_net *priv;
 369         dev->netdev_ops = &netdev_ops;
 370         dev->destructor = free_netdev;
 371         dev->flags |= IFF_NOARP;
 372         dev->flags |= IFF_POINTOPOINT;
 373         dev->mtu = GPRS_PDP_MTU;
 374         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
 375
 376         priv = netdev_priv(dev);
 377         priv->chnl.receive = chnl_recv_cb;
 378         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
 379         priv->netdev = dev;
 380         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
 381         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
 382         priv->conn_req.priority = CAIF_PRIO_LOW;
 383         /* Insert illegal value */
 384         priv->conn_req.sockaddr.u.dgm.connection_id = -1;
 385         priv->flowenabled = false;
 386
 387         ASSERT_RTNL();
 388         init_waitqueue_head(&priv->netmgmt_wq);
 389         list_add(&priv->list_field, &chnl_net_list);
 390 }
 391
 392
 393 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
 394 {
 395         struct chnl_net *priv;
 396         u8 loop;
 397         priv = netdev_priv(dev);
 398         NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID,
 399                     priv->conn_req.sockaddr.u.dgm.connection_id);
 400         NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID,
 401                     priv->conn_req.sockaddr.u.dgm.connection_id);
 402         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
 403         NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop);
 404
 405
 406         return 0;
 407 nla_put_failure:
 408         return -EMSGSIZE;
 409
 410 }
 411
 412 static void caif_netlink_parms(struct nlattr *data[],
 413                                 struct caif_connect_request *conn_req)
 414 {
 415         if (!data) {
 416                 pr_warning("CAIF: %s: no params data found\n", __func__);
 417                 return;
 418         }
 419         if (data[IFLA_CAIF_IPV4_CONNID])
 420                 conn_req->sockaddr.u.dgm.connection_id =
 421                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
 422         if (data[IFLA_CAIF_IPV6_CONNID])
 423                 conn_req->sockaddr.u.dgm.connection_id =
 424                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
 425         if (data[IFLA_CAIF_LOOPBACK]) {
 426                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
 427                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
 428                 else
 429                         conn_req->protocol = CAIFPROTO_DATAGRAM;
 430         }
 431 }
 432
 433 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
 434                           struct nlattr *tb[], struct nlattr *data[])
 435 {
 436         int ret;
 437         struct chnl_net *caifdev;
 438         ASSERT_RTNL();
 439         caifdev = netdev_priv(dev);
 440         caif_netlink_parms(data, &caifdev->conn_req);
 441         dev_net_set(caifdev->netdev, src_net);
 442
 443         ret = register_netdevice(dev);
 444         if (ret)
 445                 pr_warning("CAIF: %s(): device rtml registration failed\n",
 446                            __func__);
 447         return ret;
 448 }
 449
 450 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
 451                                 struct nlattr *data[])
 452 {
 453         struct chnl_net *caifdev;
 454         ASSERT_RTNL();
 455         caifdev = netdev_priv(dev);
 456         caif_netlink_parms(data, &caifdev->conn_req);
 457         netdev_state_change(dev);
 458         return 0;
 459 }
 460
 461 static size_t ipcaif_get_size(const struct net_device *dev)
 462 {
 463         return
 464                 /* IFLA_CAIF_IPV4_CONNID */
 465                 nla_total_size(4) +
 466                 /* IFLA_CAIF_IPV6_CONNID */
 467                 nla_total_size(4) +
 468                 /* IFLA_CAIF_LOOPBACK */
 469                 nla_total_size(2) +
 470                 0;
 471 }
 472
 473 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
 474         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
 475         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
 476         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
 477 };
 478
 479
 480 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
 481         .kind           = "caif",
 482         .priv_size      = sizeof(struct chnl_net),
 483         .setup          = ipcaif_net_setup,
 484         .maxtype        = IFLA_CAIF_MAX,
 485         .policy         = ipcaif_policy,
 486         .newlink        = ipcaif_newlink,
 487         .changelink     = ipcaif_changelink,
 488         .get_size       = ipcaif_get_size,
 489         .fill_info      = ipcaif_fill_info,
 490
 491 };
 492
 493 static int __init chnl_init_module(void)
 494 {
 495         return rtnl_link_register(&ipcaif_link_ops);
 496 }
 497
 498 static void __exit chnl_exit_module(void)
 499 {
 500         struct chnl_net *dev = NULL;
 501         struct list_head *list_node;
 502         struct list_head *_tmp;
 503         rtnl_link_unregister(&ipcaif_link_ops);
 504         rtnl_lock();
 505         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 506                 dev = list_entry(list_node, struct chnl_net, list_field);
 507                 list_del(list_node);
 508                 delete_device(dev);
 509         }
 510         rtnl_unlock();
 511 }
 512
 513 module_init(chnl_init_module);
 514 module_exit(chnl_exit_module);