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