arcnet.c

powerpc内核mpc8241linux系统下net驱动程序

      break;
#endif
    case ARC_P_DATAPOINT_BOOT:
    case ARC_P_DATAPOINT_MOUNT:
      break;
    case ARC_P_POWERLAN_BEACON:
    case ARC_P_POWERLAN_BEACON2:
      break;
    case ARC_P_LANSOFT: /* don't understand.  fall through. */
    default:
      BUGMSG(D_EXTRA,"received unknown protocol %d (%Xh) from station %d.\n",
	     arcsoft[0],arcsoft[0],saddr);
      lp->stats.rx_errors++;
      lp->stats.rx_crc_errors++;
      break;
    }

  /* If any worth-while packets have been received, a mark_bh(NET_BH)
   * has been done by netif_rx and Linux will handle them after we
   * return.
   */


}



/* Packet receiver for "standard" RFC1201-style packets
 */
static void
arcnetA_rx(struct device *dev,u_char *buf,
	   int length, u_char saddr, u_char daddr)
{
  struct arcnet_local *lp = (struct arcnet_local *)dev->priv;
  struct sk_buff *skb;
  struct ClientData *arcsoft,*soft;

  BUGMSG(D_DURING,"it's an RFC1201 packet (length=%d)\n",
	 length);

  /* compensate for EXTRA_CLIENTDATA (which isn't actually in the
   * packet)
   */
  arcsoft=(struct ClientData *)(buf-EXTRA_CLIENTDATA);
  length+=EXTRA_CLIENTDATA;

  if (arcsoft->split_flag==0xFF)  /* Exception Packet */
    {
      BUGMSG(D_DURING,"compensating for exception packet\n");

      /* skip over 4-byte junkola */
      arcsoft=(struct ClientData *)
	((u_char *)arcsoft + 4);
      length-=4;
    }

  if (!arcsoft->split_flag)		/* not split */
    {
      struct Incoming *in=&lp->incoming[saddr];

      BUGMSG(D_RX,"incoming is not split (splitflag=%d)\n",
	     arcsoft->split_flag);

      if (in->skb)	/* already assembling one! */
	{
	  BUGMSG(D_EXTRA,"aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
		 in->sequence,arcsoft->split_flag,
		 arcsoft->sequence);
	  lp->aborted_seq=arcsoft->sequence;
	  kfree_skb(in->skb);
	  lp->stats.rx_errors++;
	  lp->stats.rx_missed_errors++;
	  in->skb=NULL;
	}

      in->sequence=arcsoft->sequence;

      skb = alloc_skb(length, GFP_ATOMIC);
      if (skb == NULL) {
	BUGMSG(D_NORMAL,"Memory squeeze, dropping packet.\n");
	lp->stats.rx_dropped++;
	return;
      }
      soft=(struct ClientData *)skb->data;

      skb_put(skb,length);
      skb->dev = dev;

      memcpy((u_char *)soft+EXTRA_CLIENTDATA,
	     (u_char *)arcsoft+EXTRA_CLIENTDATA,
	     length-EXTRA_CLIENTDATA);
      soft->daddr=daddr;
      soft->saddr=saddr;

      /* ARP packets have problems when sent from DOS.
       * source address is always 0 on some systems!  So we take
       * the hardware source addr (which is impossible to fumble)
       * and insert it ourselves.
       */
      if (soft->protocol_id == ARC_P_ARP)
	{
	  struct arphdr *arp=(struct arphdr *)
	    ((char *)soft+sizeof(struct ClientData));

	  /* make sure addresses are the right length */
	  if (arp->ar_hln==1 && arp->ar_pln==4)
	    {
	      char *cptr=(char *)(arp)+sizeof(struct arphdr);

	      if (!*cptr)	/* is saddr = 00? */
		{
		  BUGMSG(D_EXTRA,"ARP source address was 00h, set to %02Xh.\n",
			 saddr);
		  lp->stats.rx_crc_errors++;
		  *cptr=saddr;
		}
	      else
		{
		  BUGMSG(D_DURING,"ARP source address (%Xh) is fine.\n",
			 *cptr);
		}
	    }
	  else
	    {
	      BUGMSG(D_NORMAL,"funny-shaped ARP packet. (%Xh, %Xh)\n",
		     arp->ar_hln,arp->ar_pln);
	      lp->stats.rx_errors++;
	      lp->stats.rx_crc_errors++;
	    }
	}

      BUGLVL(D_SKB) arcnet_dump_skb(dev,skb,"rx");

      lp->stats.rx_bytes += skb->len;
      skb->protocol=arcnetA_type_trans(skb,dev);
      netif_rx(skb);
    }
  else			/* split packet */
    {
      /* NOTE:  MSDOS ARP packet correction should only need to
       * apply to unsplit packets, since ARP packets are so short.
       *
       * My interpretation of the RFC1201 (ARCnet) document is that
       * if a packet is received out of order, the entire assembly
       * process should be aborted.
       *
       * The RFC also mentions "it is possible for successfully
       * received packets to be retransmitted."  As of 0.40 all
       * previously received packets are allowed, not just the
       * most recent one.
       *
       * We allow multiple assembly processes, one for each
       * ARCnet card possible on the network.  Seems rather like
       * a waste of memory.  Necessary?
       */

      struct Incoming *in=&lp->incoming[saddr];

      BUGMSG(D_RX,"packet is split (splitflag=%d, seq=%d)\n",
	     arcsoft->split_flag,in->sequence);

      if (in->skb && in->sequence!=arcsoft->sequence)
	{
	  BUGMSG(D_EXTRA,"wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
		 saddr,in->sequence,arcsoft->sequence,
		 arcsoft->split_flag);
	  kfree_skb(in->skb);
	  in->skb=NULL;
	  lp->stats.rx_errors++;
	  lp->stats.rx_missed_errors++;
	  in->lastpacket=in->numpackets=0;
	}

      if (arcsoft->split_flag & 1)	/* first packet in split */
	{
	  BUGMSG(D_RX,"brand new splitpacket (splitflag=%d)\n",
		 arcsoft->split_flag);
	  if (in->skb)	/* already assembling one! */
	    {
	      BUGMSG(D_EXTRA,"aborting previous (seq=%d) assembly (splitflag=%d, seq=%d)\n",
		     in->sequence,arcsoft->split_flag,
		     arcsoft->sequence);
	      lp->stats.rx_errors++;
	      lp->stats.rx_missed_errors++;
	      kfree_skb(in->skb);
	    }

	  in->sequence=arcsoft->sequence;
	  in->numpackets=((unsigned)arcsoft->split_flag>>1)+2;
	  in->lastpacket=1;

	  if (in->numpackets>16)
	    {
	      BUGMSG(D_EXTRA,"incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
		     arcsoft->split_flag);
	      lp->stats.rx_errors++;
	      lp->stats.rx_length_errors++;
	      return;
	    }

	  in->skb=skb=alloc_skb(508*in->numpackets
				+ sizeof(struct ClientData),
				GFP_ATOMIC);
	  if (skb == NULL) {
	    BUGMSG(D_NORMAL,"(split) memory squeeze, dropping packet.\n");
	    lp->stats.rx_dropped++;
	    return;
	  }

	  soft=(struct ClientData *)skb->data;

	  skb_put(skb,sizeof(struct ClientData));
	  skb->dev=dev;

	  memcpy((u_char *)soft+EXTRA_CLIENTDATA,
		 (u_char *)arcsoft+EXTRA_CLIENTDATA,
		 sizeof(struct ClientData)-EXTRA_CLIENTDATA);
	  soft->split_flag=0; /* final packet won't be split */
	}
      else			/* not first packet */
	{
	  int packetnum=((unsigned)arcsoft->split_flag>>1) + 1;

	  /* if we're not assembling, there's no point
	   * trying to continue.
	   */
	  if (!in->skb)
	    {
	      if (lp->aborted_seq != arcsoft->sequence)
		{
		  BUGMSG(D_EXTRA,"can't continue split without starting first! (splitflag=%d, seq=%d, aborted=%d)\n",
			 arcsoft->split_flag,arcsoft->sequence, lp->aborted_seq);
		  lp->stats.rx_errors++;
		  lp->stats.rx_missed_errors++;
		}
	      return;
	    }

	  in->lastpacket++;
	  if (packetnum!=in->lastpacket) /* not the right flag! */
	    {
	      /* harmless duplicate? ignore. */
	      if (packetnum<=in->lastpacket-1)
		{
		  BUGMSG(D_EXTRA,"duplicate splitpacket ignored! (splitflag=%d)\n",
			 arcsoft->split_flag);
		  lp->stats.rx_errors++;
		  lp->stats.rx_frame_errors++;
		  return;
		}

	      /* "bad" duplicate, kill reassembly */
	      BUGMSG(D_EXTRA,"out-of-order splitpacket, reassembly (seq=%d) aborted (splitflag=%d, seq=%d)\n",
		     in->sequence,arcsoft->split_flag,
		     arcsoft->sequence);
	      lp->aborted_seq=arcsoft->sequence;
	      kfree_skb(in->skb);
	      in->skb=NULL;
	      lp->stats.rx_errors++;
	      lp->stats.rx_missed_errors++;
	      in->lastpacket=in->numpackets=0;
	      return;
	    }

	  soft=(struct ClientData *)in->skb->data;
	}

      skb=in->skb;

      memcpy(skb->data+skb->len,
	     (u_char *)arcsoft+sizeof(struct ClientData),
	     length-sizeof(struct ClientData));
      skb_put(skb,length-sizeof(struct ClientData));

      soft->daddr=daddr;
      soft->saddr=saddr;

      /* are we done? */
      if (in->lastpacket == in->numpackets)
	{
	  if (!skb || !in->skb)
	    {
	      BUGMSG(D_NORMAL,"?!? done reassembling packet, no skb? (skb=%ph, in->skb=%ph)\n",
		     skb,in->skb);
	    }
	  else
	    {
	      in->skb=NULL;
	      in->lastpacket=in->numpackets=0;

	      BUGLVL(D_SKB) arcnet_dump_skb(dev,skb,"rx");

	      lp->stats.rx_bytes += skb->len;
	      skb->protocol=arcnetA_type_trans(skb,dev);
	      netif_rx(skb);
	    }
	}
    }
}


/****************************************************************************
 *                                                                          *
 * Miscellaneous routines                                                   *
 *                                                                          *
 ****************************************************************************/

/* Get the current statistics.	This may be called with the card open or
 * closed.
 */

static struct net_device_stats *arcnet_get_stats(struct device *dev)
{
  struct arcnet_local *lp = (struct arcnet_local *)dev->priv;

  return &lp->stats;
}


/* Create the ARCnet ClientData header for an arbitrary protocol layer
 *
 * saddr=NULL	means use device source address (always will anyway)
 * daddr=NULL	means leave destination address (eg unresolved arp)
 */
static int arcnetA_header(struct sk_buff *skb,struct device *dev,
			  unsigned short type,void *daddr,void *saddr,unsigned len)
{
  struct ClientData *head = (struct ClientData *)
    skb_push(skb,dev->hard_header_len);
  struct arcnet_local *lp=(struct arcnet_local *)(dev->priv);

  BUGMSG(D_DURING,"create header from %d to %d; protocol %d (%Xh); size %u.\n",
	 saddr ? *(u_char*)saddr : -1,
	 daddr ? *(u_char*)daddr : -1,
	 type,type,len);

  /* set the protocol ID according to RFC1201 */
  switch(type)
    {
    case ETH_P_IP:
      head->protocol_id=ARC_P_IP;
      break;
    case ETH_P_ARP:
      head->protocol_id=ARC_P_ARP;
      break;
    case ETH_P_RARP:
      head->protocol_id=ARC_P_RARP;
      break;
    case ETH_P_IPX:
    case ETH_P_802_3:
    case ETH_P_802_2:
      head->protocol_id=ARC_P_IPX;
      break;
    case ETH_P_ATALK:
      head->protocol_id=ARC_P_ATALK;
      break;
    default:
      BUGMSG(D_NORMAL,"I don't understand protocol %d (%Xh)\n",
	     type,type);
      lp->stats.tx_errors++;
      lp->stats.tx_aborted_errors++;
      return 0;
    }

  /*
   * Set the source hardware address.
   *
   * This is pretty pointless for most purposes, but it can help
   * in debugging.  saddr is stored in the ClientData header and
   * removed before sending the packet (since ARCnet does not allow
   * us to change the source address in the actual packet sent)
   */
  if(saddr)
    head->saddr=((u_char*)saddr)[0];
  else
    head->saddr=((u_char*)(dev->dev_addr))[0];

  head->split_flag=0;	/* split packets are done elsewhere */
  head->sequence=0;	/* so are sequence numbers */

  /* supposedly if daddr is NULL, we should ignore it... */
  if(daddr)
    {
      head->daddr=((u_char*)daddr)[0];
      return dev->hard_header_len;
    }
  else
    head->daddr=0;	/* better fill one in anyway */

  return -dev->hard_header_len;
}


/* Rebuild the ARCnet ClientData header. This is called after an ARP
 * (or in future other address resolution) has completed on this
 * sk_buff. We now let ARP fill in the other fields.
 */
static int arcnetA_rebuild_header(struct sk_buff *skb)
{
  struct ClientData *head = (struct ClientData *)skb->data;
  struct device *dev=skb->dev;
  struct arcnet_local *lp=(struct arcnet_local *)(dev->priv);
#ifdef CONFIG_INET
  int status;
#endif

  /*
   * Only ARP and IP are currently supported
   *
   * FIXME: Anyone want to spec IPv6 over ARCnet ?
   */

  if(head->protocol_id != ARC_P_IP)
    {
      BUGMSG(D_NORMAL,"I don't understand protocol type %d (%Xh) addresses!\n",
	     head->protocol_id,head->protocol_id);
      lp->stats.tx_errors++;
      lp->stats.tx_aborted_errors++;
      head->daddr=0;
      /*memcpy(eth->h_source, dev->dev_addr, dev->addr_len);*/
      return 0;
    }

  /*
   * Try to get ARP to resolve the header.
   */
#ifdef CONFIG_INET
  BUGMSG(D_DURING,"rebuild header from %d to %d; protocol %Xh\n",
	 head->saddr,head->daddr,head->protocol_id);
  status=arp_find(&(head->daddr),skb)? 1 : 0;
  BUGMSG(D_DURING," rebuilt: from %d to %d; protocol %Xh\n",
	 head->saddr,head->daddr,head->protocol_id);
  return status;
#else
  return 0;
#endif
}


/* Determine a packet's protocol ID.
 *
 * With ARCnet we have to convert everything to Ethernet-style stuff.
 */
static unsigned short arcnetA_type_trans(struct sk_buff *skb,struct device *dev)
{
  struct ClientData *head;
  struct arcnet_local *lp=(struct arcnet_local *) (dev->priv);

  /* Pull off the arcnet header. */
  skb->mac.raw=skb->data;
  skb_pull(skb,dev->hard_header_len);
  head=(struct ClientData *)skb->mac.raw;

  if (head->daddr==0)
    skb->pkt_type=PACKET_BROADCAST;
  else if (dev->flags&IFF_PROMISC)
    {
      /* if we're not sending to ourselves :) */
      if (head->daddr != dev->dev_addr[0])
	skb->pkt_type=PACKET_OTHERHOST;
    }

  /* now return the protocol number */
  switch (head->protocol_id)
    {
    case ARC_P_IP:		return htons(ETH_P_IP);
    case ARC_P_ARP:		return htons(ETH_P_ARP);
    case ARC_P_RARP:	return htons(ETH_P_RARP);

    case ARC_P_IPX:
    case ARC_P_NOVELL_EC:
      return htons(ETH_P_802_3);
    default:
      lp->stats.rx_errors++;
      lp->stats.rx_crc_errors++;
      return 0;
    }

  return htons(ETH_P_IP);
}


#ifdef CONFIG_ARCNET_ETH
/****************************************************************************
 *                                                                          *
 * Ethernet-Encap Support                                                   *
 *                                                                          *
 ****************************************************************************/

/* Initialize the arc0e device.
 */
static int arcnetE_init(struct device *dev)
{
  struct arcnet_local *lp = (struct arcnet_local *)dev->priv;

  ether_setup(dev); /* we're emulating ether here, not ARCnet */
  dev->dev_addr[0]=0;
  dev->dev_addr[5]=lp->stationid;
  dev->mtu=512-sizeof(struct archdr)-dev->hard_header_len-1;
  dev->open=arcnetE_open_close;
  dev->stop=arcnetE_open_close;
  dev->hard_start_xmit=arcnetE_send_packet;

  return 0;
}


/* Bring up/down the arc0e device - we don't actually have to do anything,
 * since our parent arc0 handles the card I/O itself.
 */
static int arcnetE_open_close(struct device *dev)
{
  return 0;
}


/* Called by the kernel in order to transmit an ethernet-type packet.
 */
static int
arcnetE_send_packet(struct sk_buff *skb, struct device *dev)
{
  struct arcnet_local *lp = (struct arcnet_local *)dev->priv;
  int bad,oldmask=0;