net/irda/irlan/irlan_eth.c

   1 /*********************************************************************
   2  *
   3  * Filename:      irlan_eth.c
   4  * Version:
   5  * Description:
   6  * Status:        Experimental.
   7  * Author:        Dag Brattli <dagb@cs.uit.no>
   8  * Created at:    Thu Oct 15 08:37:58 1998
   9  * Modified at:   Tue Mar 21 09:06:41 2000
  10  * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11  * Sources:       skeleton.c by Donald Becker <becker@CESDIS.gsfc.nasa.gov>
  12  *                slip.c by Laurence Culhane,   <loz@holmes.demon.co.uk>
  13  *                          Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  14  *
  15  *     Copyright (c) 1998-2000 Dag Brattli, All Rights Reserved.
  16  *
  17  *     This program is free software; you can redistribute it and/or
  18  *     modify it under the terms of the GNU General Public License as
  19  *     published by the Free Software Foundation; either version 2 of
  20  *     the License, or (at your option) any later version.
  21  *
  22  *     Neither Dag Brattli nor University of Tromsø admit liability nor
  23  *     provide warranty for any of this software. This material is
  24  *     provided "AS-IS" and at no charge.
  25  *
  26  ********************************************************************/
  27
  28 #include <linux/config.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/etherdevice.h>
  31 #include <linux/inetdevice.h>
  32 #include <linux/if_arp.h>
  33 #include <linux/module.h>
  34 #include <net/arp.h>
  35
  36 #include <net/irda/irda.h>
  37 #include <net/irda/irmod.h>
  38 #include <net/irda/irlan_common.h>
  39 #include <net/irda/irlan_client.h>
  40 #include <net/irda/irlan_event.h>
  41 #include <net/irda/irlan_eth.h>
  42
  43 static int  irlan_eth_open(struct net_device *dev);
  44 static int  irlan_eth_close(struct net_device *dev);
  45 static int  irlan_eth_xmit(struct sk_buff *skb, struct net_device *dev);
  46 static void irlan_eth_set_multicast_list( struct net_device *dev);
  47 static struct net_device_stats *irlan_eth_get_stats(struct net_device *dev);
  48
  49 /*
  50  * Function irlan_eth_setup (dev)
  51  *
  52  *    The network device initialization function.
  53  *
  54  */
  55 static void irlan_eth_setup(struct net_device *dev)
  56 {
  57         dev->open               = irlan_eth_open;
  58         dev->stop               = irlan_eth_close;
  59         dev->hard_start_xmit    = irlan_eth_xmit;
  60         dev->get_stats          = irlan_eth_get_stats;
  61         dev->set_multicast_list = irlan_eth_set_multicast_list;
  62         dev->destructor         = free_netdev;
  63
  64         SET_MODULE_OWNER(dev);
  65
  66         ether_setup(dev);
  67
  68         /*
  69          * Lets do all queueing in IrTTP instead of this device driver.
  70          * Queueing here as well can introduce some strange latency
  71          * problems, which we will avoid by setting the queue size to 0.
  72          */
  73         /*
  74          * The bugs in IrTTP and IrLAN that created this latency issue
  75          * have now been fixed, and we can propagate flow control properly
  76          * to the network layer. However, this requires a minimal queue of
  77          * packets for the device.
  78          * Without flow control, the Tx Queue is 14 (ttp) + 0 (dev) = 14
  79          * With flow control, the Tx Queue is 7 (ttp) + 4 (dev) = 11
  80          * See irlan_eth_flow_indication()...
  81          * Note : this number was randomly selected and would need to
  82          * be adjusted.
  83          * Jean II */
  84         dev->tx_queue_len = 4;
  85 }
  86
  87 /*
  88  * Function alloc_irlandev
  89  *
  90  *    Allocate network device and control block
  91  *
  92  */
  93 struct net_device *alloc_irlandev(const char *name)
  94 {
  95         return alloc_netdev(sizeof(struct irlan_cb), name,
  96                             irlan_eth_setup);
  97 }
  98
  99 /*
 100  * Function irlan_eth_open (dev)
 101  *
 102  *    Network device has been opened by user
 103  *
 104  */
 105 static int irlan_eth_open(struct net_device *dev)
 106 {
 107         struct irlan_cb *self = netdev_priv(dev);
 108
 109         IRDA_DEBUG(2, "%s()\n", __FUNCTION__ );
 110
 111         /* Ready to play! */
 112         netif_stop_queue(dev); /* Wait until data link is ready */
 113
 114         /* We are now open, so time to do some work */
 115         self->disconnect_reason = 0;
 116         irlan_client_wakeup(self, self->saddr, self->daddr);
 117
 118         /* Make sure we have a hardware address before we return,
 119            so DHCP clients gets happy */
 120         return wait_event_interruptible(self->open_wait,
 121                                         !self->tsap_data->connected);
 122 }
 123
 124 /*
 125  * Function irlan_eth_close (dev)
 126  *
 127  *    Stop the ether network device, his function will usually be called by
 128  *    ifconfig down. We should now disconnect the link, We start the
 129  *    close timer, so that the instance will be removed if we are unable
 130  *    to discover the remote device after the disconnect.
 131  */
 132 static int irlan_eth_close(struct net_device *dev)
 133 {
 134         struct irlan_cb *self = netdev_priv(dev);
 135
 136         IRDA_DEBUG(2, "%s()\n", __FUNCTION__ );
 137
 138         /* Stop device */
 139         netif_stop_queue(dev);
 140
 141         irlan_close_data_channel(self);
 142         irlan_close_tsaps(self);
 143
 144         irlan_do_client_event(self, IRLAN_LMP_DISCONNECT, NULL);
 145         irlan_do_provider_event(self, IRLAN_LMP_DISCONNECT, NULL);
 146
 147         /* Remove frames queued on the control channel */
 148         skb_queue_purge(&self->client.txq);
 149
 150         self->client.tx_busy = 0;
 151
 152         return 0;
 153 }
 154
 155 /*
 156  * Function irlan_eth_tx (skb)
 157  *
 158  *    Transmits ethernet frames over IrDA link.
 159  *
 160  */
 161 static int irlan_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 162 {
 163         struct irlan_cb *self = netdev_priv(dev);
 164         int ret;
 165
 166         /* skb headroom large enough to contain all IrDA-headers? */
 167         if ((skb_headroom(skb) < self->max_header_size) || (skb_shared(skb))) {
 168                 struct sk_buff *new_skb =
 169                         skb_realloc_headroom(skb, self->max_header_size);
 170
 171                 /*  We have to free the original skb anyway */
 172                 dev_kfree_skb(skb);
 173
 174                 /* Did the realloc succeed? */
 175                 if (new_skb == NULL)
 176                         return 0;
 177
 178                 /* Use the new skb instead */
 179                 skb = new_skb;
 180         }
 181
 182         dev->trans_start = jiffies;
 183
 184         /* Now queue the packet in the transport layer */
 185         if (self->use_udata)
 186                 ret = irttp_udata_request(self->tsap_data, skb);
 187         else
 188                 ret = irttp_data_request(self->tsap_data, skb);
 189
 190         if (ret < 0) {
 191                 /*
 192                  * IrTTPs tx queue is full, so we just have to
 193                  * drop the frame! You might think that we should
 194                  * just return -1 and don't deallocate the frame,
 195                  * but that is dangerous since it's possible that
 196                  * we have replaced the original skb with a new
 197                  * one with larger headroom, and that would really
 198                  * confuse do_dev_queue_xmit() in dev.c! I have
 199                  * tried :-) DB
 200                  */
 201                 /* irttp_data_request already free the packet */
 202                 self->stats.tx_dropped++;
 203         } else {
 204                 self->stats.tx_packets++;
 205                 self->stats.tx_bytes += skb->len;
 206         }
 207
 208         return 0;
 209 }
 210
 211 /*
 212  * Function irlan_eth_receive (handle, skb)
 213  *
 214  *    This function gets the data that is received on the data channel
 215  *
 216  */
 217 int irlan_eth_receive(void *instance, void *sap, struct sk_buff *skb)
 218 {
 219         struct irlan_cb *self = instance;
 220
 221         if (skb == NULL) {
 222                 ++self->stats.rx_dropped;
 223                 return 0;
 224         }
 225         if (skb->len < ETH_HLEN) {
 226                 IRDA_DEBUG(0, "%s() : IrLAN frame too short (%d)\n",
 227                            __FUNCTION__, skb->len);
 228                 ++self->stats.rx_dropped;
 229                 dev_kfree_skb(skb);
 230                 return 0;
 231         }
 232
 233         /*
 234          * Adopt this frame! Important to set all these fields since they
 235          * might have been previously set by the low level IrDA network
 236          * device driver
 237          */
 238         skb->dev = self->dev;
 239         skb->protocol=eth_type_trans(skb, skb->dev); /* Remove eth header */
 240
 241         self->stats.rx_packets++;
 242         self->stats.rx_bytes += skb->len;
 243
 244         netif_rx(skb);   /* Eat it! */
 245
 246         return 0;
 247 }
 248
 249 /*
 250  * Function irlan_eth_flow (status)
 251  *
 252  *    Do flow control between IP/Ethernet and IrLAN/IrTTP. This is done by
 253  *    controlling the queue stop/start.
 254  *
 255  * The IrDA link layer has the advantage to have flow control, and
 256  * IrTTP now properly handles that. Flow controlling the higher layers
 257  * prevent us to drop Tx packets in here (up to 15% for a TCP socket,
 258  * more for UDP socket).
 259  * Also, this allow us to reduce the overall transmit queue, which means
 260  * less latency in case of mixed traffic.
 261  * Jean II
 262  */
 263 void irlan_eth_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
 264 {
 265         struct irlan_cb *self;
 266         struct net_device *dev;
 267
 268         self = (struct irlan_cb *) instance;
 269
 270         IRDA_ASSERT(self != NULL, return;);
 271         IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
 272
 273         dev = self->dev;
 274
 275         IRDA_ASSERT(dev != NULL, return;);
 276
 277         IRDA_DEBUG(0, "%s() : flow %s ; running %d\n", __FUNCTION__,
 278                    flow == FLOW_STOP ? "FLOW_STOP" : "FLOW_START",
 279                    netif_running(dev));
 280
 281         switch (flow) {
 282         case FLOW_STOP:
 283                 /* IrTTP is full, stop higher layers */
 284                 netif_stop_queue(dev);
 285                 break;
 286         case FLOW_START:
 287         default:
 288                 /* Tell upper layers that its time to transmit frames again */
 289                 /* Schedule network layer */
 290                 netif_wake_queue(dev);
 291                 break;
 292         }
 293 }
 294
 295 /*
 296  * Function irlan_etc_send_gratuitous_arp (dev)
 297  *
 298  *    Send gratuitous ARP to announce that we have changed
 299  *    hardware address, so that all peers updates their ARP tables
 300  */
 301 void irlan_eth_send_gratuitous_arp(struct net_device *dev)
 302 {
 303         struct in_device *in_dev;
 304
 305         /*
 306          * When we get a new MAC address do a gratuitous ARP. This
 307          * is useful if we have changed access points on the same
 308          * subnet.
 309          */
 310 #ifdef CONFIG_INET
 311         IRDA_DEBUG(4, "IrLAN: Sending gratuitous ARP\n");
 312         rcu_read_lock();
 313         in_dev = __in_dev_get_rcu(dev);
 314         if (in_dev == NULL)
 315                 goto out;
 316         if (in_dev->ifa_list)
 317
 318         arp_send(ARPOP_REQUEST, ETH_P_ARP,
 319                  in_dev->ifa_list->ifa_address,
 320                  dev,
 321                  in_dev->ifa_list->ifa_address,
 322                  NULL, dev->dev_addr, NULL);
 323 out:
 324         rcu_read_unlock();
 325 #endif /* CONFIG_INET */
 326 }
 327
 328 /*
 329  * Function set_multicast_list (dev)
 330  *
 331  *    Configure the filtering of the device
 332  *
 333  */
 334 #define HW_MAX_ADDRS 4 /* Must query to get it! */
 335 static void irlan_eth_set_multicast_list(struct net_device *dev)
 336 {
 337         struct irlan_cb *self = netdev_priv(dev);
 338
 339         IRDA_DEBUG(2, "%s()\n", __FUNCTION__ );
 340
 341         /* Check if data channel has been connected yet */
 342         if (self->client.state != IRLAN_DATA) {
 343                 IRDA_DEBUG(1, "%s(), delaying!\n", __FUNCTION__ );
 344                 return;
 345         }
 346
 347         if (dev->flags & IFF_PROMISC) {
 348                 /* Enable promiscuous mode */
 349                 IRDA_WARNING("Promiscous mode not implemented by IrLAN!\n");
 350         }
 351         else if ((dev->flags & IFF_ALLMULTI) || dev->mc_count > HW_MAX_ADDRS) {
 352                 /* Disable promiscuous mode, use normal mode. */
 353                 IRDA_DEBUG(4, "%s(), Setting multicast filter\n", __FUNCTION__ );
 354                 /* hardware_set_filter(NULL); */
 355
 356                 irlan_set_multicast_filter(self, TRUE);
 357         }
 358         else if (dev->mc_count) {
 359                 IRDA_DEBUG(4, "%s(), Setting multicast filter\n", __FUNCTION__ );
 360                 /* Walk the address list, and load the filter */
 361                 /* hardware_set_filter(dev->mc_list); */
 362
 363                 irlan_set_multicast_filter(self, TRUE);
 364         }
 365         else {
 366                 IRDA_DEBUG(4, "%s(), Clearing multicast filter\n", __FUNCTION__ );
 367                 irlan_set_multicast_filter(self, FALSE);
 368         }
 369
 370         if (dev->flags & IFF_BROADCAST)
 371                 irlan_set_broadcast_filter(self, TRUE);
 372         else
 373                 irlan_set_broadcast_filter(self, FALSE);
 374 }
 375
 376 /*
 377  * Function irlan_get_stats (dev)
 378  *
 379  *    Get the current statistics for this device
 380  *
 381  */
 382 static struct net_device_stats *irlan_eth_get_stats(struct net_device *dev)
 383 {
 384         struct irlan_cb *self = netdev_priv(dev);
 385
 386         return &self->stats;
 387 }