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@super.org>
  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/fs.h>
  25 #include <linux/types.h>
  26 #include <linux/string.h>
  27 #include <linux/socket.h>
  28 #include <linux/errno.h>
  29 #include <linux/fcntl.h>
  30 #include <linux/in.h>
  31 #include <linux/if_ether.h>     /* For the statistics structure. */
  32 
  33 #include <asm/system.h>
  34 #include <asm/segment.h>
  35 #include <asm/io.h>
  36 
  37 #include <linux/inet.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/etherdevice.h>
  40 #include <linux/skbuff.h>
  41 
  42 
  43 static int
  44 loopback_xmit(struct sk_buff *skb, struct device *dev)
     /*  */
  45 {
  46   struct enet_statistics *stats = (struct enet_statistics *)dev->priv;
  47   int done;
  48 
  49   if (skb == NULL || dev == NULL) return(0);
  50 
  51   cli();
  52   if (dev->tbusy != 0) {
  53         sti();
  54         stats->tx_errors++;
  55         return(1);
  56   }
  57   dev->tbusy = 1;
  58   sti();
  59   
  60   /* FIXME: Optimise so buffers with skb->free=1 are not copied but
  61      instead are lobbed from tx queue to rx queue */
  62 
  63   done = dev_rint(skb->data, skb->len, 0, dev);
  64   dev_kfree_skb(skb, FREE_WRITE);
  65 
  66   while (done != 1) {
  67         done = dev_rint(NULL, 0, 0, dev);
  68   }
  69   stats->tx_packets++;
  70 
  71   dev->tbusy = 0;
  72 
  73 #if 1
  74         __asm__("cmpl $0,_intr_count\n\t"
  75                 "jne 1f\n\t"
  76                 "movl _bh_active,%%eax\n\t"
  77                 "testl _bh_mask,%%eax\n\t"
  78                 "je 1f\n\t"
  79                 "incl _intr_count\n\t"
  80                 "call _do_bottom_half\n\t"
  81                 "decl _intr_count\n"
  82                 "1:"
  83                 :
  84                 :
  85                 : "ax", "dx", "cx");
  86 #endif
  87 
  88   return(0);
  89 }
  90 
  91 static struct enet_statistics *
  92 get_stats(struct device *dev)
     /*  */
  93 {
  94     return (struct enet_statistics *)dev->priv;
  95 }
  96 
  97 static int loopback_open(struct device *dev)
     /*  */
  98 {
  99         dev->flags|=IFF_LOOPBACK;
 100         return 0;
 101 }
 102 
 103 /* Initialize the rest of the LOOPBACK device. */
 104 int
 105 loopback_init(struct device *dev)
     /*  */
 106 {
 107   int i;
 108 
 109   dev->mtu              = 2000;                 /* MTU                  */
 110   dev->tbusy            = 0;
 111   dev->hard_start_xmit  = loopback_xmit;
 112   dev->open             = NULL;
 113 #if 1
 114   dev->hard_header      = eth_header;
 115   dev->hard_header_len  = ETH_HLEN;             /* 14                   */
 116   dev->addr_len         = ETH_ALEN;             /* 6                    */
 117   dev->type             = ARPHRD_ETHER;         /* 0x0001               */
 118   dev->type_trans       = eth_type_trans;
 119   dev->rebuild_header   = eth_rebuild_header;
 120   dev->open             = loopback_open;
 121 #else
 122   dev->hard_header_length = 0;
 123   dev->addr_len         = 0;
 124   dev->type             = 0;                    /* loopback_type (0)    */
 125   dev->hard_header      = NULL;
 126   dev->type_trans       = NULL;
 127   dev->rebuild_header   = NULL;
 128 #endif
 129 
 130   /* New-style flags. */
 131   dev->flags            = IFF_LOOPBACK|IFF_BROADCAST;
 132   dev->family           = AF_INET;
 133 #ifdef CONFIG_INET    
 134   dev->pa_addr          = in_aton("127.0.0.1");
 135   dev->pa_brdaddr       = in_aton("127.255.255.255");
 136   dev->pa_mask          = in_aton("255.0.0.0");
 137   dev->pa_alen          = sizeof(unsigned long);
 138 #endif  
 139   dev->priv = kmalloc(sizeof(struct enet_statistics), GFP_KERNEL);
 140   memset(dev->priv, 0, sizeof(struct enet_statistics));
 141   dev->get_stats = get_stats;
 142 
 143   /* Fill in the generic fields of the device structure. */
 144   for (i = 0; i < DEV_NUMBUFFS; i++)
 145         skb_queue_head_init(&dev->buffs[i]);
 146   
 147   return(0);
 148 };
/* */
root/drivers/net/loopback.c

DEFINITIONS
