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 <linux/sched.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 netdev_tx_t  irlan_eth_xmit(struct sk_buff *skb,
  46                                          struct net_device *dev);
  47 static void irlan_eth_set_multicast_list(struct net_device *dev);
  48
  49 static const struct net_device_ops irlan_eth_netdev_ops = {
  50         .ndo_open               = irlan_eth_open,
  51         .ndo_stop               = irlan_eth_close,
  52         .ndo_start_xmit         = irlan_eth_xmit,
  53         .ndo_set_rx_mode        = 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, NET_NAME_UNKNOWN,
 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         /* Ready to play! */
 114         netif_stop_queue(dev); /* Wait until data link is ready */
 115
 116         /* We are now open, so time to do some work */
 117         self->disconnect_reason = 0;
 118         irlan_client_wakeup(self, self->saddr, self->daddr);
 119
 120         /* Make sure we have a hardware address before we return,
 121            so DHCP clients gets happy */
 122         return wait_event_interruptible(self->open_wait,
 123                                         !self->tsap_data->connected);
 124 }
 125
 126 /*
 127  * Function irlan_eth_close (dev)
 128  *
 129  *    Stop the ether network device, his function will usually be called by
 130  *    ifconfig down. We should now disconnect the link, We start the
 131  *    close timer, so that the instance will be removed if we are unable
 132  *    to discover the remote device after the disconnect.
 133  */
 134 static int irlan_eth_close(struct net_device *dev)
 135 {
 136         struct irlan_cb *self = netdev_priv(dev);
 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 netdev_tx_t irlan_eth_xmit(struct sk_buff *skb,
 162                                         struct net_device *dev)
 163 {
 164         struct irlan_cb *self = netdev_priv(dev);
 165         int ret;
 166         unsigned int len;
 167
 168         /* skb headroom large enough to contain all IrDA-headers? */
 169         if ((skb_headroom(skb) < self->max_header_size) || (skb_shared(skb))) {
 170                 struct sk_buff *new_skb =
 171                         skb_realloc_headroom(skb, self->max_header_size);
 172
 173                 /*  We have to free the original skb anyway */
 174                 dev_kfree_skb(skb);
 175
 176                 /* Did the realloc succeed? */
 177                 if (new_skb == NULL)
 178                         return NETDEV_TX_OK;
 179
 180                 /* Use the new skb instead */
 181                 skb = new_skb;
 182         }
 183
 184         dev->trans_start = jiffies;
 185
 186         len = skb->len;
 187         /* Now queue the packet in the transport layer */
 188         if (self->use_udata)
 189                 ret = irttp_udata_request(self->tsap_data, skb);
 190         else
 191                 ret = irttp_data_request(self->tsap_data, skb);
 192
 193         if (ret < 0) {
 194                 /*
 195                  * IrTTPs tx queue is full, so we just have to
 196                  * drop the frame! You might think that we should
 197                  * just return -1 and don't deallocate the frame,
 198                  * but that is dangerous since it's possible that
 199                  * we have replaced the original skb with a new
 200                  * one with larger headroom, and that would really
 201                  * confuse do_dev_queue_xmit() in dev.c! I have
 202                  * tried :-) DB
 203                  */
 204                 /* irttp_data_request already free the packet */
 205                 dev->stats.tx_dropped++;
 206         } else {
 207                 dev->stats.tx_packets++;
 208                 dev->stats.tx_bytes += len;
 209         }
 210
 211         return NETDEV_TX_OK;
 212 }
 213
 214 /*
 215  * Function irlan_eth_receive (handle, skb)
 216  *
 217  *    This function gets the data that is received on the data channel
 218  *
 219  */
 220 int irlan_eth_receive(void *instance, void *sap, struct sk_buff *skb)
 221 {
 222         struct irlan_cb *self = instance;
 223         struct net_device *dev = self->dev;
 224
 225         if (skb == NULL) {
 226                 dev->stats.rx_dropped++;
 227                 return 0;
 228         }
 229         if (skb->len < ETH_HLEN) {
 230                 pr_debug("%s() : IrLAN frame too short (%d)\n",
 231                          __func__, skb->len);
 232                 dev->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, dev); /* Remove eth header */
 243
 244         dev->stats.rx_packets++;
 245         dev->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 = 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         pr_debug("%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         /* Check if data channel has been connected yet */
 310         if (self->client.state != IRLAN_DATA) {
 311                 pr_debug("%s(), delaying!\n", __func__);
 312                 return;
 313         }
 314
 315         if (dev->flags & IFF_PROMISC) {
 316                 /* Enable promiscuous mode */
 317                 net_warn_ratelimited("Promiscuous mode not implemented by IrLAN!\n");
 318         } else if ((dev->flags & IFF_ALLMULTI) ||
 319                  netdev_mc_count(dev) > HW_MAX_ADDRS) {
 320                 /* Disable promiscuous mode, use normal mode. */
 321                 pr_debug("%s(), Setting multicast filter\n", __func__);
 322                 /* hardware_set_filter(NULL); */
 323
 324                 irlan_set_multicast_filter(self, TRUE);
 325         } else if (!netdev_mc_empty(dev)) {
 326                 pr_debug("%s(), Setting multicast filter\n", __func__);
 327                 /* Walk the address list, and load the filter */
 328                 /* hardware_set_filter(dev->mc_list); */
 329
 330                 irlan_set_multicast_filter(self, TRUE);
 331         } else {
 332                 pr_debug("%s(), Clearing multicast filter\n", __func__);
 333                 irlan_set_multicast_filter(self, FALSE);
 334         }
 335
 336         if (dev->flags & IFF_BROADCAST)
 337                 irlan_set_broadcast_filter(self, TRUE);
 338         else
 339                 irlan_set_broadcast_filter(self, FALSE);
 340 }