drivers/net/loopback.c

/* */
This source file includes following definitions.
loopback_xmit
get_stats
loopback_open
loopback_init
   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              Pseudo-driver for the loopback interface.
   7  *
   8  * Version:     @(#)loopback.c  1.0.4b  08/16/93
   9  *
  10  * Authors:     Ross Biro, <bir7@leland.Stanford.Edu>
  11  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12  *              Donald Becker, <becker@cesdis.gsfc.nasa.gov>
  13  *
  14  *              Alan Cox        :       Fixed oddments for NET3.014
  15  *
  16  *              This program is free software; you can redistribute it and/or
  17  *              modify it under the terms of the GNU General Public License
  18  *              as published by the Free Software Foundation; either version
  19  *              2 of the License, or (at your option) any later version.
  20  */
  21 #include <linux/config.h>
  22 #include <linux/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/fs.h>
  26 #include <linux/types.h>
  27 #include <linux/string.h>
  28 #include <linux/socket.h>
  29 #include <linux/errno.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/in.h>
  32 #include <linux/if_ether.h>     /* For the statistics structure. */
  33 
  34 #include <asm/system.h>
  35 #include <asm/segment.h>
  36 #include <asm/io.h>
  37 
  38 #include <linux/inet.h>
  39 #include <linux/netdevice.h>
  40 #include <linux/etherdevice.h>
  41 #include <linux/skbuff.h>
  42 
  43 
  44 static int
  45 loopback_xmit(struct sk_buff *skb, struct device *dev)
     /*  */
  46 {
  47   struct enet_statistics *stats = (struct enet_statistics *)dev->priv;
  48   int done;
  49 
  50   if (skb == NULL || dev == NULL) return(0);
  51 
  52   cli();
  53   if (dev->tbusy != 0) {
  54         sti();
  55         stats->tx_errors++;
  56         return(1);
  57   }
  58   dev->tbusy = 1;
  59   sti();
  60   
  61   /* FIXME: Optimise so buffers with skb->free=1 are not copied but
  62      instead are lobbed from tx queue to rx queue */
  63 
  64   done = dev_rint(skb->data, skb->len, 0, dev);
  65   dev_kfree_skb(skb, FREE_WRITE);
  66 
  67   while (done != 1) {
  68         done = dev_rint(NULL, 0, 0, dev);
  69   }
  70   stats->tx_packets++;
  71 
  72   dev->tbusy = 0;
  73 
  74   if (!intr_count && (bh_active & bh_mask)) {
  75         start_bh_atomic();
  76         do_bottom_half();
  77         end_bh_atomic();
  78   }
  79 
  80   return(0);
  81 }
  82 
  83 static struct enet_statistics *
  84 get_stats(struct device *dev)
     /*  */
  85 {
  86     return (struct enet_statistics *)dev->priv;
  87 }
  88 
  89 static int loopback_open(struct device *dev)
     /*  */
  90 {
  91         dev->flags|=IFF_LOOPBACK;
  92         return 0;
  93 }
  94 
  95 /* Initialize the rest of the LOOPBACK device. */
  96 int
  97 loopback_init(struct device *dev)
     /*  */
  98 {
  99   int i;
 100 
 101   dev->mtu              = 2000;                 /* MTU                  */
 102   dev->tbusy            = 0;
 103   dev->hard_start_xmit  = loopback_xmit;
 104   dev->open             = NULL;
 105 #if 1
 106   dev->hard_header      = eth_header;
 107   dev->hard_header_len  = ETH_HLEN;             /* 14                   */
 108   dev->addr_len         = ETH_ALEN;             /* 6                    */
 109   dev->type             = ARPHRD_ETHER;         /* 0x0001               */
 110   dev->type_trans       = eth_type_trans;
 111   dev->rebuild_header   = eth_rebuild_header;
 112   dev->open             = loopback_open;
 113 #else
 114   dev->hard_header_length = 0;
 115   dev->addr_len         = 0;
 116   dev->type             = 0;                    /* loopback_type (0)    */
 117   dev->hard_header      = NULL;
 118   dev->type_trans       = NULL;
 119   dev->rebuild_header   = NULL;
 120 #endif
 121 
 122   /* New-style flags. */
 123   dev->flags            = IFF_LOOPBACK|IFF_BROADCAST;
 124   dev->family           = AF_INET;
 125 #ifdef CONFIG_INET    
 126   dev->pa_addr          = in_aton("127.0.0.1");
 127   dev->pa_brdaddr       = in_aton("127.255.255.255");
 128   dev->pa_mask          = in_aton("255.0.0.0");
 129   dev->pa_alen          = sizeof(unsigned long);
 130 #endif  
 131   dev->priv = kmalloc(sizeof(struct enet_statistics), GFP_KERNEL);
 132   memset(dev->priv, 0, sizeof(struct enet_statistics));
 133   dev->get_stats = get_stats;
 134 
 135   /* Fill in the generic fields of the device structure. */
 136   for (i = 0; i < DEV_NUMBUFFS; i++)
 137         skb_queue_head_init(&dev->buffs[i]);
 138   
 139   return(0);
 140 };
/* */
root/drivers/net/loopback.c

DEFINITIONS
