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 SIZE_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         ASSERT_RTNL();
 236         priv = netdev_priv(dev);
 237         if (!priv) {
 238                 pr_debug("CAIF: %s(): chnl_net_open: no priv\n", __func__);
 239                 return -ENODEV;
 240         }
 241
 242         if (priv->state != CAIF_CONNECTING) {
 243                 priv->state = CAIF_CONNECTING;
 244                 result = caif_connect_client(&priv->conn_req, &priv->chnl);
 245                 if (result != 0) {
 246                                 priv->state = CAIF_DISCONNECTED;
 247                                 pr_debug("CAIF: %s(): err: "
 248                                         "Unable to register and open device,"
 249                                         " Err:%d\n",
 250                                         __func__,
 251                                         result);
 252                                 return result;
 253                 }
 254         }
 255
 256         result = wait_event_interruptible_timeout(priv->netmgmt_wq,
 257                                                 priv->state != CAIF_CONNECTING,
 258                                                 CONNECT_TIMEOUT);
 259
 260         if (result == -ERESTARTSYS) {
 261                 pr_debug("CAIF: %s(): wait_event_interruptible"
 262                          " woken by a signal\n", __func__);
 263                 return -ERESTARTSYS;
 264         }
 265         if (result == 0) {
 266                 pr_debug("CAIF: %s(): connect timeout\n", __func__);
 267                 caif_disconnect_client(&priv->chnl);
 268                 priv->state = CAIF_DISCONNECTED;
 269                 pr_debug("CAIF: %s(): state disconnected\n", __func__);
 270                 return -ETIMEDOUT;
 271         }
 272
 273         if (priv->state != CAIF_CONNECTED) {
 274                 pr_debug("CAIF: %s(): connect failed\n", __func__);
 275                 return -ECONNREFUSED;
 276         }
 277         pr_debug("CAIF: %s(): CAIF Netdevice connected\n", __func__);
 278         return 0;
 279 }
 280
 281 static int chnl_net_stop(struct net_device *dev)
 282 {
 283         struct chnl_net *priv;
 284
 285         ASSERT_RTNL();
 286         priv = netdev_priv(dev);
 287         priv->state = CAIF_DISCONNECTED;
 288         caif_disconnect_client(&priv->chnl);
 289         return 0;
 290 }
 291
 292 static int chnl_net_init(struct net_device *dev)
 293 {
 294         struct chnl_net *priv;
 295         ASSERT_RTNL();
 296         priv = netdev_priv(dev);
 297         strncpy(priv->name, dev->name, sizeof(priv->name));
 298         return 0;
 299 }
 300
 301 static void chnl_net_uninit(struct net_device *dev)
 302 {
 303         struct chnl_net *priv;
 304         ASSERT_RTNL();
 305         priv = netdev_priv(dev);
 306         robust_list_del(&priv->list_field);
 307 }
 308
 309 static const struct net_device_ops netdev_ops = {
 310         .ndo_open = chnl_net_open,
 311         .ndo_stop = chnl_net_stop,
 312         .ndo_init = chnl_net_init,
 313         .ndo_uninit = chnl_net_uninit,
 314         .ndo_start_xmit = chnl_net_start_xmit,
 315 };
 316
 317 static void ipcaif_net_setup(struct net_device *dev)
 318 {
 319         struct chnl_net *priv;
 320         dev->netdev_ops = &netdev_ops;
 321         dev->destructor = free_netdev;
 322         dev->flags |= IFF_NOARP;
 323         dev->flags |= IFF_POINTOPOINT;
 324         dev->needed_headroom = CAIF_NEEDED_HEADROOM;
 325         dev->needed_tailroom = CAIF_NEEDED_TAILROOM;
 326         dev->mtu = SIZE_MTU;
 327         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
 328
 329         priv = netdev_priv(dev);
 330         priv->chnl.receive = chnl_recv_cb;
 331         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
 332         priv->netdev = dev;
 333         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
 334         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
 335         priv->conn_req.priority = CAIF_PRIO_LOW;
 336         /* Insert illegal value */
 337         priv->conn_req.sockaddr.u.dgm.connection_id = -1;
 338         priv->flowenabled = false;
 339
 340         ASSERT_RTNL();
 341         init_waitqueue_head(&priv->netmgmt_wq);
 342         list_add(&priv->list_field, &chnl_net_list);
 343 }
 344
 345
 346 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
 347 {
 348         struct chnl_net *priv;
 349         u8 loop;
 350         priv = netdev_priv(dev);
 351         NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID,
 352                     priv->conn_req.sockaddr.u.dgm.connection_id);
 353         NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID,
 354                     priv->conn_req.sockaddr.u.dgm.connection_id);
 355         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
 356         NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop);
 357
 358
 359         return 0;
 360 nla_put_failure:
 361         return -EMSGSIZE;
 362
 363 }
 364
 365 static void caif_netlink_parms(struct nlattr *data[],
 366                                 struct caif_connect_request *conn_req)
 367 {
 368         if (!data) {
 369                 pr_warning("CAIF: %s: no params data found\n", __func__);
 370                 return;
 371         }
 372         if (data[IFLA_CAIF_IPV4_CONNID])
 373                 conn_req->sockaddr.u.dgm.connection_id =
 374                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
 375         if (data[IFLA_CAIF_IPV6_CONNID])
 376                 conn_req->sockaddr.u.dgm.connection_id =
 377                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
 378         if (data[IFLA_CAIF_LOOPBACK]) {
 379                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
 380                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
 381                 else
 382                         conn_req->protocol = CAIFPROTO_DATAGRAM;
 383         }
 384 }
 385
 386 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
 387                           struct nlattr *tb[], struct nlattr *data[])
 388 {
 389         int ret;
 390         struct chnl_net *caifdev;
 391         ASSERT_RTNL();
 392         caifdev = netdev_priv(dev);
 393         caif_netlink_parms(data, &caifdev->conn_req);
 394         dev_net_set(caifdev->netdev, src_net);
 395
 396         ret = register_netdevice(dev);
 397         if (ret)
 398                 pr_warning("CAIF: %s(): device rtml registration failed\n",
 399                            __func__);
 400         return ret;
 401 }
 402
 403 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
 404                                 struct nlattr *data[])
 405 {
 406         struct chnl_net *caifdev;
 407         ASSERT_RTNL();
 408         caifdev = netdev_priv(dev);
 409         caif_netlink_parms(data, &caifdev->conn_req);
 410         netdev_state_change(dev);
 411         return 0;
 412 }
 413
 414 static size_t ipcaif_get_size(const struct net_device *dev)
 415 {
 416         return
 417                 /* IFLA_CAIF_IPV4_CONNID */
 418                 nla_total_size(4) +
 419                 /* IFLA_CAIF_IPV6_CONNID */
 420                 nla_total_size(4) +
 421                 /* IFLA_CAIF_LOOPBACK */
 422                 nla_total_size(2) +
 423                 0;
 424 }
 425
 426 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
 427         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
 428         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
 429         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
 430 };
 431
 432
 433 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
 434         .kind           = "caif",
 435         .priv_size      = sizeof(struct chnl_net),
 436         .setup          = ipcaif_net_setup,
 437         .maxtype        = IFLA_CAIF_MAX,
 438         .policy         = ipcaif_policy,
 439         .newlink        = ipcaif_newlink,
 440         .changelink     = ipcaif_changelink,
 441         .get_size       = ipcaif_get_size,
 442         .fill_info      = ipcaif_fill_info,
 443
 444 };
 445
 446 static int __init chnl_init_module(void)
 447 {
 448         return rtnl_link_register(&ipcaif_link_ops);
 449 }
 450
 451 static void __exit chnl_exit_module(void)
 452 {
 453         struct chnl_net *dev = NULL;
 454         struct list_head *list_node;
 455         struct list_head *_tmp;
 456         rtnl_link_unregister(&ipcaif_link_ops);
 457         rtnl_lock();
 458         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 459                 dev = list_entry(list_node, struct chnl_net, list_field);
 460                 list_del(list_node);
 461                 delete_device(dev);
 462         }
 463         rtnl_unlock();
 464 }
 465
 466 module_init(chnl_init_module);
 467 module_exit(chnl_exit_module);