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/netdevice.h>
  29 #include <linux/etherdevice.h>
  30 #include <linux/inetdevice.h>
  31 #include <linux/if_arp.h>
  32 #include <linux/module.h>
  33 #include <net/arp.h>
  34
  35 #include <net/irda/irda.h>
  36 #include <net/irda/irmod.h>
  37 #include <net/irda/irlan_common.h>
  38 #include <net/irda/irlan_client.h>
  39 #include <net/irda/irlan_event.h>
  40 #include <net/irda/irlan_eth.h>
  41
  42 static int  irlan_eth_open(struct net_device *dev);
  43 static int  irlan_eth_close(struct net_device *dev);
  44 static int  irlan_eth_xmit(struct sk_buff *skb, struct net_device *dev);
  45 static void irlan_eth_set_multicast_list( struct net_device *dev);
  46 static struct net_device_stats *irlan_eth_get_stats(struct net_device *dev);
  47
  48 static const struct net_device_ops irlan_eth_netdev_ops = {
  49         .ndo_open               = irlan_eth_open,
  50         .ndo_stop               = irlan_eth_close,
  51         .ndo_start_xmit         = irlan_eth_xmit,
  52         .ndo_get_stats          = irlan_eth_get_stats,
  53         .ndo_set_multicast_list = irlan_eth_set_multicast_list,
  54         .ndo_change_mtu         = eth_change_mtu,
  55         .ndo_validate_addr      = eth_validate_addr,
  56 };
  57
  58 /*
  59  * Function irlan_eth_setup (dev)
  60  *
  61  *    The network device initialization function.
  62  *
  63  */
  64 static void irlan_eth_setup(struct net_device *dev)
  65 {
  66         ether_setup(dev);
  67
  68         dev->netdev_ops         = &irlan_eth_netdev_ops;
  69         dev->destructor         = free_netdev;
  70
  71
  72         /*
  73          * Lets do all queueing in IrTTP instead of this device driver.
  74          * Queueing here as well can introduce some strange latency
  75          * problems, which we will avoid by setting the queue size to 0.
  76          */
  77         /*
  78          * The bugs in IrTTP and IrLAN that created this latency issue
  79          * have now been fixed, and we can propagate flow control properly
  80          * to the network layer. However, this requires a minimal queue of
  81          * packets for the device.
  82          * Without flow control, the Tx Queue is 14 (ttp) + 0 (dev) = 14
  83          * With flow control, the Tx Queue is 7 (ttp) + 4 (dev) = 11
  84          * See irlan_eth_flow_indication()...
  85          * Note : this number was randomly selected and would need to
  86          * be adjusted.
  87          * Jean II */
  88         dev->tx_queue_len = 4;
  89 }
  90
  91 /*
  92  * Function alloc_irlandev
  93  *
  94  *    Allocate network device and control block
  95  *
  96  */
  97 struct net_device *alloc_irlandev(const char *name)
  98 {
  99         return alloc_netdev(sizeof(struct irlan_cb), name,
 100                             irlan_eth_setup);
 101 }
 102
 103 /*
 104  * Function irlan_eth_open (dev)
 105  *
 106  *    Network device has been opened by user
 107  *
 108  */
 109 static int irlan_eth_open(struct net_device *dev)
 110 {
 111         struct irlan_cb *self = netdev_priv(dev);
 112
 113         IRDA_DEBUG(2, "%s()\n", __func__ );
 114
 115         /* Ready to play! */
 116         netif_stop_queue(dev); /* Wait until data link is ready */
 117
 118         /* We are now open, so time to do some work */
 119         self->disconnect_reason = 0;
 120         irlan_client_wakeup(self, self->saddr, self->daddr);
 121
 122         /* Make sure we have a hardware address before we return,
 123            so DHCP clients gets happy */
 124         return wait_event_interruptible(self->open_wait,
 125                                         !self->tsap_data->connected);
 126 }
 127
 128 /*
 129  * Function irlan_eth_close (dev)
 130  *
 131  *    Stop the ether network device, his function will usually be called by
 132  *    ifconfig down. We should now disconnect the link, We start the
 133  *    close timer, so that the instance will be removed if we are unable
 134  *    to discover the remote device after the disconnect.
 135  */
 136 static int irlan_eth_close(struct net_device *dev)
 137 {
 138         struct irlan_cb *self = netdev_priv(dev);
 139
 140         IRDA_DEBUG(2, "%s()\n", __func__ );
 141
 142         /* Stop device */
 143         netif_stop_queue(dev);
 144
 145         irlan_close_data_channel(self);
 146         irlan_close_tsaps(self);
 147
 148         irlan_do_client_event(self, IRLAN_LMP_DISCONNECT, NULL);
 149         irlan_do_provider_event(self, IRLAN_LMP_DISCONNECT, NULL);
 150
 151         /* Remove frames queued on the control channel */
 152         skb_queue_purge(&self->client.txq);
 153
 154         self->client.tx_busy = 0;
 155
 156         return 0;
 157 }
 158
 159 /*
 160  * Function irlan_eth_tx (skb)
 161  *
 162  *    Transmits ethernet frames over IrDA link.
 163  *
 164  */
 165 static int irlan_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 166 {
 167         struct irlan_cb *self = netdev_priv(dev);
 168         int ret;
 169
 170         /* skb headroom large enough to contain all IrDA-headers? */
 171         if ((skb_headroom(skb) < self->max_header_size) || (skb_shared(skb))) {
 172                 struct sk_buff *new_skb =
 173                         skb_realloc_headroom(skb, self->max_header_size);
 174
 175                 /*  We have to free the original skb anyway */
 176                 dev_kfree_skb(skb);
 177
 178                 /* Did the realloc succeed? */
 179                 if (new_skb == NULL)
 180                         return 0;
 181
 182                 /* Use the new skb instead */
 183                 skb = new_skb;
 184         }
 185
 186         dev->trans_start = jiffies;
 187
 188         /* Now queue the packet in the transport layer */
 189         if (self->use_udata)
 190                 ret = irttp_udata_request(self->tsap_data, skb);
 191         else
 192                 ret = irttp_data_request(self->tsap_data, skb);
 193
 194         if (ret < 0) {
 195                 /*
 196                  * IrTTPs tx queue is full, so we just have to
 197                  * drop the frame! You might think that we should
 198                  * just return -1 and don't deallocate the frame,
 199                  * but that is dangerous since it's possible that
 200                  * we have replaced the original skb with a new
 201                  * one with larger headroom, and that would really
 202                  * confuse do_dev_queue_xmit() in dev.c! I have
 203                  * tried :-) DB
 204                  */
 205                 /* irttp_data_request already free the packet */
 206                 self->stats.tx_dropped++;
 207         } else {
 208                 self->stats.tx_packets++;
 209                 self->stats.tx_bytes += skb->len;
 210         }
 211
 212         return 0;
 213 }
 214
 215 /*
 216  * Function irlan_eth_receive (handle, skb)
 217  *
 218  *    This function gets the data that is received on the data channel
 219  *
 220  */
 221 int irlan_eth_receive(void *instance, void *sap, struct sk_buff *skb)
 222 {
 223         struct irlan_cb *self = instance;
 224
 225         if (skb == NULL) {
 226                 ++self->stats.rx_dropped;
 227                 return 0;
 228         }
 229         if (skb->len < ETH_HLEN) {
 230                 IRDA_DEBUG(0, "%s() : IrLAN frame too short (%d)\n",
 231                            __func__, skb->len);
 232                 ++self->stats.rx_dropped;
 233                 dev_kfree_skb(skb);
 234                 return 0;
 235         }
 236
 237         /*
 238          * Adopt this frame! Important to set all these fields since they
 239          * might have been previously set by the low level IrDA network
 240          * device driver
 241          */
 242         skb->protocol = eth_type_trans(skb, self->dev); /* Remove eth header */
 243
 244         self->stats.rx_packets++;
 245         self->stats.rx_bytes += skb->len;
 246
 247         netif_rx(skb);   /* Eat it! */
 248
 249         return 0;
 250 }
 251
 252 /*
 253  * Function irlan_eth_flow (status)
 254  *
 255  *    Do flow control between IP/Ethernet and IrLAN/IrTTP. This is done by
 256  *    controlling the queue stop/start.
 257  *
 258  * The IrDA link layer has the advantage to have flow control, and
 259  * IrTTP now properly handles that. Flow controlling the higher layers
 260  * prevent us to drop Tx packets in here (up to 15% for a TCP socket,
 261  * more for UDP socket).
 262  * Also, this allow us to reduce the overall transmit queue, which means
 263  * less latency in case of mixed traffic.
 264  * Jean II
 265  */
 266 void irlan_eth_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
 267 {
 268         struct irlan_cb *self;
 269         struct net_device *dev;
 270
 271         self = (struct irlan_cb *) instance;
 272
 273         IRDA_ASSERT(self != NULL, return;);
 274         IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
 275
 276         dev = self->dev;
 277
 278         IRDA_ASSERT(dev != NULL, return;);
 279
 280         IRDA_DEBUG(0, "%s() : flow %s ; running %d\n", __func__,
 281                    flow == FLOW_STOP ? "FLOW_STOP" : "FLOW_START",
 282                    netif_running(dev));
 283
 284         switch (flow) {
 285         case FLOW_STOP:
 286                 /* IrTTP is full, stop higher layers */
 287                 netif_stop_queue(dev);
 288                 break;
 289         case FLOW_START:
 290         default:
 291                 /* Tell upper layers that its time to transmit frames again */
 292                 /* Schedule network layer */
 293                 netif_wake_queue(dev);
 294                 break;
 295         }
 296 }
 297
 298 /*
 299  * Function set_multicast_list (dev)
 300  *
 301  *    Configure the filtering of the device
 302  *
 303  */
 304 #define HW_MAX_ADDRS 4 /* Must query to get it! */
 305 static void irlan_eth_set_multicast_list(struct net_device *dev)
 306 {
 307         struct irlan_cb *self = netdev_priv(dev);
 308
 309         IRDA_DEBUG(2, "%s()\n", __func__ );
 310
 311         /* Check if data channel has been connected yet */
 312         if (self->client.state != IRLAN_DATA) {
 313                 IRDA_DEBUG(1, "%s(), delaying!\n", __func__ );
 314                 return;
 315         }
 316
 317         if (dev->flags & IFF_PROMISC) {
 318                 /* Enable promiscuous mode */
 319                 IRDA_WARNING("Promiscuous mode not implemented by IrLAN!\n");
 320         }
 321         else if ((dev->flags & IFF_ALLMULTI) || dev->mc_count > HW_MAX_ADDRS) {
 322                 /* Disable promiscuous mode, use normal mode. */
 323                 IRDA_DEBUG(4, "%s(), Setting multicast filter\n", __func__ );
 324                 /* hardware_set_filter(NULL); */
 325
 326                 irlan_set_multicast_filter(self, TRUE);
 327         }
 328         else if (dev->mc_count) {
 329                 IRDA_DEBUG(4, "%s(), Setting multicast filter\n", __func__ );
 330                 /* Walk the address list, and load the filter */
 331                 /* hardware_set_filter(dev->mc_list); */
 332
 333                 irlan_set_multicast_filter(self, TRUE);
 334         }
 335         else {
 336                 IRDA_DEBUG(4, "%s(), Clearing multicast filter\n", __func__ );
 337                 irlan_set_multicast_filter(self, FALSE);
 338         }
 339
 340         if (dev->flags & IFF_BROADCAST)
 341                 irlan_set_broadcast_filter(self, TRUE);
 342         else
 343                 irlan_set_broadcast_filter(self, FALSE);
 344 }
 345
 346 /*
 347  * Function irlan_get_stats (dev)
 348  *
 349  *    Get the current statistics for this device
 350  *
 351  */
 352 static struct net_device_stats *irlan_eth_get_stats(struct net_device *dev)
 353 {
 354         struct irlan_cb *self = netdev_priv(dev);
 355
 356         return &self->stats;
 357 }