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