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