net/caif/chnl_net.c

   1 /*
   2  * Copyright (C) ST-Ericsson AB 2010
   3  * Authors:     Sjur Brendeland
   4  *              Daniel Martensson
   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/ip.h>
  17 #include <linux/sched.h>
  18 #include <linux/sockios.h>
  19 #include <linux/caif/if_caif.h>
  20 #include <net/rtnetlink.h>
  21 #include <net/caif/caif_layer.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 #define UNDEF_CONNID 0xffffffff
  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 caif_connect_request conn_req;
  48         struct list_head list_field;
  49         struct net_device *netdev;
  50         char name[256];
  51         wait_queue_head_t netmgmt_wq;
  52         /* Flow status to remember and control the transmission. */
  53         bool flowenabled;
  54         enum caif_states state;
  55 };
  56
  57 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
  58 {
  59         struct sk_buff *skb;
  60         struct chnl_net *priv;
  61         int pktlen;
  62         const u8 *ip_version;
  63         u8 buf;
  64
  65         priv = container_of(layr, struct chnl_net, chnl);
  66         if (!priv)
  67                 return -EINVAL;
  68
  69         skb = (struct sk_buff *) cfpkt_tonative(pkt);
  70
  71         /* Get length of CAIF packet. */
  72         pktlen = skb->len;
  73
  74         /* Pass some minimum information and
  75          * send the packet to the net stack.
  76          */
  77         skb->dev = priv->netdev;
  78
  79         /* check the version of IP */
  80         ip_version = skb_header_pointer(skb, 0, 1, &buf);
  81         if (!ip_version) {
  82                 kfree_skb(skb);
  83                 return -EINVAL;
  84         }
  85
  86         switch (*ip_version >> 4) {
  87         case 4:
  88                 skb->protocol = htons(ETH_P_IP);
  89                 break;
  90         case 6:
  91                 skb->protocol = htons(ETH_P_IPV6);
  92                 break;
  93         default:
  94                 kfree_skb(skb);
  95                 priv->netdev->stats.rx_errors++;
  96                 return -EINVAL;
  97         }
  98
  99         /* If we change the header in loop mode, the checksum is corrupted. */
 100         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 101                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 102         else
 103                 skb->ip_summed = CHECKSUM_NONE;
 104
 105         if (in_interrupt())
 106                 netif_rx(skb);
 107         else
 108                 netif_rx_ni(skb);
 109
 110         /* Update statistics. */
 111         priv->netdev->stats.rx_packets++;
 112         priv->netdev->stats.rx_bytes += pktlen;
 113
 114         return 0;
 115 }
 116
 117 static int delete_device(struct chnl_net *dev)
 118 {
 119         ASSERT_RTNL();
 120         if (dev->netdev)
 121                 unregister_netdevice(dev->netdev);
 122         return 0;
 123 }
 124
 125 static void close_work(struct work_struct *work)
 126 {
 127         struct chnl_net *dev = NULL;
 128         struct list_head *list_node;
 129         struct list_head *_tmp;
 130
 131         rtnl_lock();
 132         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 133                 dev = list_entry(list_node, struct chnl_net, list_field);
 134                 if (dev->state == CAIF_SHUTDOWN)
 135                         dev_close(dev->netdev);
 136         }
 137         rtnl_unlock();
 138 }
 139 static DECLARE_WORK(close_worker, close_work);
 140
 141 static void chnl_hold(struct cflayer *lyr)
 142 {
 143         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 144         dev_hold(priv->netdev);
 145 }
 146
 147 static void chnl_put(struct cflayer *lyr)
 148 {
 149         struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
 150         dev_put(priv->netdev);
 151 }
 152
 153 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
 154                              int phyid)
 155 {
 156         struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
 157         pr_debug("NET flowctrl func called flow: %s\n",
 158                 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
 159                 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
 160                 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
 161                 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
 162                 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
 163                 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
 164                  "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
 165
 166
 167
 168         switch (flow) {
 169         case CAIF_CTRLCMD_FLOW_OFF_IND:
 170                 priv->flowenabled = false;
 171                 netif_stop_queue(priv->netdev);
 172                 break;
 173         case CAIF_CTRLCMD_DEINIT_RSP:
 174                 priv->state = CAIF_DISCONNECTED;
 175                 break;
 176         case CAIF_CTRLCMD_INIT_FAIL_RSP:
 177                 priv->state = CAIF_DISCONNECTED;
 178                 wake_up_interruptible(&priv->netmgmt_wq);
 179                 break;
 180         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
 181                 priv->state = CAIF_SHUTDOWN;
 182                 netif_tx_disable(priv->netdev);
 183                 schedule_work(&close_worker);
 184                 break;
 185         case CAIF_CTRLCMD_FLOW_ON_IND:
 186                 priv->flowenabled = true;
 187                 netif_wake_queue(priv->netdev);
 188                 break;
 189         case CAIF_CTRLCMD_INIT_RSP:
 190                 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
 191                 priv->state = CAIF_CONNECTED;
 192                 priv->flowenabled = true;
 193                 netif_wake_queue(priv->netdev);
 194                 wake_up_interruptible(&priv->netmgmt_wq);
 195                 break;
 196         default:
 197                 break;
 198         }
 199 }
 200
 201 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 202 {
 203         struct chnl_net *priv;
 204         struct cfpkt *pkt = NULL;
 205         int len;
 206         int result = -1;
 207         /* Get our private data. */
 208         priv = netdev_priv(dev);
 209
 210         if (skb->len > priv->netdev->mtu) {
 211                 pr_warn("Size of skb exceeded MTU\n");
 212                 kfree_skb(skb);
 213                 dev->stats.tx_errors++;
 214                 return NETDEV_TX_OK;
 215         }
 216
 217         if (!priv->flowenabled) {
 218                 pr_debug("dropping packets flow off\n");
 219                 kfree_skb(skb);
 220                 dev->stats.tx_dropped++;
 221                 return NETDEV_TX_OK;
 222         }
 223
 224         if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
 225                 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
 226
 227         /* Store original SKB length. */
 228         len = skb->len;
 229
 230         pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
 231
 232         /* Send the packet down the stack. */
 233         result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
 234         if (result) {
 235                 dev->stats.tx_dropped++;
 236                 return NETDEV_TX_OK;
 237         }
 238
 239         /* Update statistics. */
 240         dev->stats.tx_packets++;
 241         dev->stats.tx_bytes += len;
 242
 243         return NETDEV_TX_OK;
 244 }
 245
 246 static int chnl_net_open(struct net_device *dev)
 247 {
 248         struct chnl_net *priv = NULL;
 249         int result = -1;
 250         int llifindex, headroom, tailroom, mtu;
 251         struct net_device *lldev;
 252         ASSERT_RTNL();
 253         priv = netdev_priv(dev);
 254         if (!priv) {
 255                 pr_debug("chnl_net_open: no priv\n");
 256                 return -ENODEV;
 257         }
 258
 259         if (priv->state != CAIF_CONNECTING) {
 260                 priv->state = CAIF_CONNECTING;
 261                 result = caif_connect_client(dev_net(dev), &priv->conn_req,
 262                                                 &priv->chnl, &llifindex,
 263                                                 &headroom, &tailroom);
 264                 if (result != 0) {
 265                                 pr_debug("err: "
 266                                          "Unable to register and open device,"
 267                                          " Err:%d\n",
 268                                          result);
 269                                 goto error;
 270                 }
 271
 272                 lldev = __dev_get_by_index(dev_net(dev), llifindex);
 273
 274                 if (lldev == NULL) {
 275                         pr_debug("no interface?\n");
 276                         result = -ENODEV;
 277                         goto error;
 278                 }
 279
 280                 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
 281                 dev->hard_header_len = headroom + lldev->hard_header_len +
 282                         lldev->needed_tailroom;
 283
 284                 /*
 285                  * MTU, head-room etc is not know before we have a
 286                  * CAIF link layer device available. MTU calculation may
 287                  * override initial RTNL configuration.
 288                  * MTU is minimum of current mtu, link layer mtu pluss
 289                  * CAIF head and tail, and PDP GPRS contexts max MTU.
 290                  */
 291                 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
 292                 mtu = min_t(int, GPRS_PDP_MTU, mtu);
 293                 dev_set_mtu(dev, mtu);
 294
 295                 if (mtu < 100) {
 296                         pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
 297                         result = -ENODEV;
 298                         goto error;
 299                 }
 300         }
 301
 302         rtnl_unlock();  /* Release RTNL lock during connect wait */
 303
 304         result = wait_event_interruptible_timeout(priv->netmgmt_wq,
 305                                                 priv->state != CAIF_CONNECTING,
 306                                                 CONNECT_TIMEOUT);
 307
 308         rtnl_lock();
 309
 310         if (result == -ERESTARTSYS) {
 311                 pr_debug("wait_event_interruptible woken by a signal\n");
 312                 result = -ERESTARTSYS;
 313                 goto error;
 314         }
 315
 316         if (result == 0) {
 317                 pr_debug("connect timeout\n");
 318                 result = -ETIMEDOUT;
 319                 goto error;
 320         }
 321
 322         if (priv->state != CAIF_CONNECTED) {
 323                 pr_debug("connect failed\n");
 324                 result = -ECONNREFUSED;
 325                 goto error;
 326         }
 327         pr_debug("CAIF Netdevice connected\n");
 328         return 0;
 329
 330 error:
 331         caif_disconnect_client(dev_net(dev), &priv->chnl);
 332         priv->state = CAIF_DISCONNECTED;
 333         pr_debug("state disconnected\n");
 334         return result;
 335
 336 }
 337
 338 static int chnl_net_stop(struct net_device *dev)
 339 {
 340         struct chnl_net *priv;
 341
 342         ASSERT_RTNL();
 343         priv = netdev_priv(dev);
 344         priv->state = CAIF_DISCONNECTED;
 345         caif_disconnect_client(dev_net(dev), &priv->chnl);
 346         return 0;
 347 }
 348
 349 static int chnl_net_init(struct net_device *dev)
 350 {
 351         struct chnl_net *priv;
 352         ASSERT_RTNL();
 353         priv = netdev_priv(dev);
 354         strncpy(priv->name, dev->name, sizeof(priv->name));
 355         INIT_LIST_HEAD(&priv->list_field);
 356         return 0;
 357 }
 358
 359 static void chnl_net_uninit(struct net_device *dev)
 360 {
 361         struct chnl_net *priv;
 362         ASSERT_RTNL();
 363         priv = netdev_priv(dev);
 364         list_del_init(&priv->list_field);
 365 }
 366
 367 static const struct net_device_ops netdev_ops = {
 368         .ndo_open = chnl_net_open,
 369         .ndo_stop = chnl_net_stop,
 370         .ndo_init = chnl_net_init,
 371         .ndo_uninit = chnl_net_uninit,
 372         .ndo_start_xmit = chnl_net_start_xmit,
 373 };
 374
 375 static void chnl_net_destructor(struct net_device *dev)
 376 {
 377         struct chnl_net *priv = netdev_priv(dev);
 378         caif_free_client(&priv->chnl);
 379 }
 380
 381 static void ipcaif_net_setup(struct net_device *dev)
 382 {
 383         struct chnl_net *priv;
 384         dev->netdev_ops = &netdev_ops;
 385         dev->needs_free_netdev = true;
 386         dev->priv_destructor = chnl_net_destructor;
 387         dev->flags |= IFF_NOARP;
 388         dev->flags |= IFF_POINTOPOINT;
 389         dev->mtu = GPRS_PDP_MTU;
 390         dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
 391
 392         priv = netdev_priv(dev);
 393         priv->chnl.receive = chnl_recv_cb;
 394         priv->chnl.ctrlcmd = chnl_flowctrl_cb;
 395         priv->netdev = dev;
 396         priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
 397         priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
 398         priv->conn_req.priority = CAIF_PRIO_LOW;
 399         /* Insert illegal value */
 400         priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
 401         priv->flowenabled = false;
 402
 403         init_waitqueue_head(&priv->netmgmt_wq);
 404 }
 405
 406
 407 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
 408 {
 409         struct chnl_net *priv;
 410         u8 loop;
 411         priv = netdev_priv(dev);
 412         if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
 413                         priv->conn_req.sockaddr.u.dgm.connection_id) ||
 414             nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
 415                         priv->conn_req.sockaddr.u.dgm.connection_id))
 416                 goto nla_put_failure;
 417         loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
 418         if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
 419                 goto nla_put_failure;
 420         return 0;
 421 nla_put_failure:
 422         return -EMSGSIZE;
 423
 424 }
 425
 426 static void caif_netlink_parms(struct nlattr *data[],
 427                                struct caif_connect_request *conn_req)
 428 {
 429         if (!data) {
 430                 pr_warn("no params data found\n");
 431                 return;
 432         }
 433         if (data[IFLA_CAIF_IPV4_CONNID])
 434                 conn_req->sockaddr.u.dgm.connection_id =
 435                         nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
 436         if (data[IFLA_CAIF_IPV6_CONNID])
 437                 conn_req->sockaddr.u.dgm.connection_id =
 438                         nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
 439         if (data[IFLA_CAIF_LOOPBACK]) {
 440                 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
 441                         conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
 442                 else
 443                         conn_req->protocol = CAIFPROTO_DATAGRAM;
 444         }
 445 }
 446
 447 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
 448                           struct nlattr *tb[], struct nlattr *data[],
 449                           struct netlink_ext_ack *extack)
 450 {
 451         int ret;
 452         struct chnl_net *caifdev;
 453         ASSERT_RTNL();
 454         caifdev = netdev_priv(dev);
 455         caif_netlink_parms(data, &caifdev->conn_req);
 456
 457         ret = register_netdevice(dev);
 458         if (ret)
 459                 pr_warn("device rtml registration failed\n");
 460         else
 461                 list_add(&caifdev->list_field, &chnl_net_list);
 462
 463         /* Use ifindex as connection id, and use loopback channel default. */
 464         if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
 465                 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
 466                 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
 467         }
 468         return ret;
 469 }
 470
 471 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
 472                              struct nlattr *data[],
 473                              struct netlink_ext_ack *extack)
 474 {
 475         struct chnl_net *caifdev;
 476         ASSERT_RTNL();
 477         caifdev = netdev_priv(dev);
 478         caif_netlink_parms(data, &caifdev->conn_req);
 479         netdev_state_change(dev);
 480         return 0;
 481 }
 482
 483 static size_t ipcaif_get_size(const struct net_device *dev)
 484 {
 485         return
 486                 /* IFLA_CAIF_IPV4_CONNID */
 487                 nla_total_size(4) +
 488                 /* IFLA_CAIF_IPV6_CONNID */
 489                 nla_total_size(4) +
 490                 /* IFLA_CAIF_LOOPBACK */
 491                 nla_total_size(2) +
 492                 0;
 493 }
 494
 495 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
 496         [IFLA_CAIF_IPV4_CONNID]       = { .type = NLA_U32 },
 497         [IFLA_CAIF_IPV6_CONNID]       = { .type = NLA_U32 },
 498         [IFLA_CAIF_LOOPBACK]          = { .type = NLA_U8 }
 499 };
 500
 501
 502 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
 503         .kind           = "caif",
 504         .priv_size      = sizeof(struct chnl_net),
 505         .setup          = ipcaif_net_setup,
 506         .maxtype        = IFLA_CAIF_MAX,
 507         .policy         = ipcaif_policy,
 508         .newlink        = ipcaif_newlink,
 509         .changelink     = ipcaif_changelink,
 510         .get_size       = ipcaif_get_size,
 511         .fill_info      = ipcaif_fill_info,
 512
 513 };
 514
 515 static int __init chnl_init_module(void)
 516 {
 517         return rtnl_link_register(&ipcaif_link_ops);
 518 }
 519
 520 static void __exit chnl_exit_module(void)
 521 {
 522         struct chnl_net *dev = NULL;
 523         struct list_head *list_node;
 524         struct list_head *_tmp;
 525         rtnl_link_unregister(&ipcaif_link_ops);
 526         rtnl_lock();
 527         list_for_each_safe(list_node, _tmp, &chnl_net_list) {
 528                 dev = list_entry(list_node, struct chnl_net, list_field);
 529                 list_del_init(list_node);
 530                 delete_device(dev);
 531         }
 532         rtnl_unlock();
 533 }
 534
 535 module_init(chnl_init_module);
 536 module_exit(chnl_exit_module);