net/inet/eth.c

/* */
This source file includes following definitions.
eth_print
eth_setup
eth_dump
eth_header
eth_rebuild_header
eth_add_arp
eth_type_trans
   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  *              Ethernet-type device handling.
   7  *
   8  * Version:     @(#)eth.c       1.0.7   05/25/93
   9  *
  10  * Authors:     Ross Biro, <bir7@leland.Stanford.Edu>
  11  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12  *              Mark Evans, <evansmp@uhura.aston.ac.uk>
  13  * 
  14  * Fixes:
  15  *              Mr Linux        : Arp problems
  16  *              Alan Cox        : Generic queue tidyup (very tiny here)
  17  *              Alan Cox        : eth_header ntohs should be htons
  18  *              Alan Cox        : eth_rebuild_header missing an htons and
  19  *                                minor other things.
  20  *              Tegge           : Arp bug fixes. 
  21  *
  22  *              This program is free software; you can redistribute it and/or
  23  *              modify it under the terms of the GNU General Public License
  24  *              as published by the Free Software Foundation; either version
  25  *              2 of the License, or (at your option) any later version.
  26  */
  27 #include <asm/segment.h>
  28 #include <asm/system.h>
  29 #include <linux/types.h>
  30 #include <linux/kernel.h>
  31 #include <linux/sched.h>
  32 #include <linux/string.h>
  33 #include <linux/mm.h>
  34 #include <linux/socket.h>
  35 #include <linux/in.h>
  36 #include "inet.h"
  37 #include "dev.h"
  38 #include "eth.h"
  39 #include "ip.h"
  40 #include "route.h"
  41 #include "protocol.h"
  42 #include "tcp.h"
  43 #include "skbuff.h"
  44 #include "sock.h"
  45 #include <linux/errno.h>
  46 #include "arp.h"
  47 
  48 
  49 /* Display an Ethernet address in readable format. */
  50 char *eth_print(unsigned char *ptr)
     /*  */
  51 {
  52   static char buff[64];
  53 
  54   if (ptr == NULL) return("[NONE]");
  55   sprintf(buff, "%02X:%02X:%02X:%02X:%02X:%02X",
  56         (ptr[0] & 255), (ptr[1] & 255), (ptr[2] & 255),
  57         (ptr[3] & 255), (ptr[4] & 255), (ptr[5] & 255)
  58   );
  59   return(buff);
  60 }
  61 
  62 void eth_setup(char *str, int *ints)
     /*  */
  63 {
  64         struct device *d = dev_base;
  65 
  66         if (!str || !*str)
  67                 return;
  68         while (d) {
  69                 if (!strcmp(str,d->name)) {
  70                         if (ints[0] > 0)
  71                                 d->irq=ints[1];
  72                         if (ints[0] > 1)
  73                                 d->base_addr=ints[2];
  74                         if (ints[0] > 2)
  75                                 d->mem_start=ints[3];
  76                         if (ints[0] > 3)
  77                                 d->mem_end=ints[4];
  78                         break;
  79                 }
  80                 d=d->next;
  81         }
  82 }
  83 
  84 /* Display the contents of the Ethernet MAC header. */
  85 void
  86 eth_dump(struct ethhdr *eth)
     /*  */
  87 {
  88   if (inet_debug != DBG_ETH) return;
  89 
  90   printk("eth: SRC = %s ", eth_print(eth->h_source));
  91   printk("DST = %s ", eth_print(eth->h_dest));
  92   printk("TYPE = %04X\n", ntohs(eth->h_proto));
  93 }
  94 
  95 
  96 /* Create the Ethernet MAC header. */
  97 int
  98 eth_header(unsigned char *buff, struct device *dev, unsigned short type,
     /*  */
  99            unsigned long daddr, unsigned long saddr, unsigned len)
 100 {
 101   struct ethhdr *eth;
 102 
 103   DPRINTF((DBG_DEV, "ETH: header(%s, ", in_ntoa(saddr)));
 104   DPRINTF((DBG_DEV, "%s, 0x%X)\n", in_ntoa(daddr), type));
 105 
 106   /* Fill in the basic Ethernet MAC header. */
 107   eth = (struct ethhdr *) buff;
 108   eth->h_proto = htons(type);
 109 
 110   /* We don't ARP for the LOOPBACK device... */
 111   if (dev->flags & IFF_LOOPBACK) {
 112         DPRINTF((DBG_DEV, "ETH: No header for loopback\n"));
 113         memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
 114         memset(eth->h_dest, 0, dev->addr_len);
 115         return(dev->hard_header_len);
 116   }
 117 
 118   /* Check if we can use the MAC BROADCAST address. */
 119   if (chk_addr(daddr) == IS_BROADCAST) {
 120         DPRINTF((DBG_DEV, "ETH: Using MAC Broadcast\n"));
 121         memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
 122         memcpy(eth->h_dest, dev->broadcast, dev->addr_len);
 123         return(dev->hard_header_len);
 124   }
 125   cli();
 126   memcpy(eth->h_source, &saddr, 4);
 127   /* No. Ask ARP to resolve the Ethernet address. */
 128   if (arp_find(eth->h_dest, daddr, dev, dev->pa_addr)) 
 129   {
 130         sti();
 131         if(type!=ETH_P_IP)
 132                 printk("Erk: protocol %X got into an arp request state!\n",type);
 133         return(-dev->hard_header_len);
 134   } 
 135   else
 136   {
 137         memcpy(eth->h_source,dev->dev_addr,dev->addr_len);      /* This was missing causing chaos if the
 138                                                                    header built correctly! */
 139         sti();
 140         return(dev->hard_header_len);
 141   }
 142 }
 143 
 144 
 145 /* Rebuild the Ethernet MAC header. */
 146 int
 147 eth_rebuild_header(void *buff, struct device *dev)
     /*  */
 148 {
 149   struct ethhdr *eth;
 150   unsigned long src, dst;
 151 
 152   DPRINTF((DBG_DEV, "ETH: Using MAC Broadcast\n"));
 153   eth = (struct ethhdr *) buff;
 154   src = *(unsigned long *) eth->h_source;
 155   dst = *(unsigned long *) eth->h_dest;
 156   DPRINTF((DBG_DEV, "ETH: RebuildHeader: SRC=%s ", in_ntoa(src)));
 157   DPRINTF((DBG_DEV, "DST=%s\n", in_ntoa(dst)));
 158   if(eth->h_proto!=htons(ETH_P_ARP))    /* This ntohs kind of helps a bit! */
 159           if (arp_find(eth->h_dest, dst, dev, dev->pa_addr /* src */)) return(1);
 160   memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
 161   return(0);
 162 }
 163 
 164 
 165 /* Add an ARP entry for a host on this interface. */
 166 void
 167 eth_add_arp(unsigned long addr, struct sk_buff *skb, struct device *dev)
     /*  */
 168 {
 169   struct ethhdr *eth;
 170 
 171   eth = (struct ethhdr *) skb->data;
 172   arp_add(addr, eth->h_source, dev);
 173 }
 174 
 175 
 176 /* Determine the packet's protocol ID. */
 177 unsigned short
 178 eth_type_trans(struct sk_buff *skb, struct device *dev)
     /*  */
 179 {
 180   struct ethhdr *eth;
 181 
 182   eth = (struct ethhdr *) skb->data;
 183 
 184   if(ntohs(eth->h_proto)<1536)
 185         return(htons(ETH_P_802_3));
 186   return(eth->h_proto);
 187 }
/* */
root/net/inet/eth.c

DEFINITIONS
