patch-2.3.36 linux/drivers/net/arcnet/rfc1051.c

• Lines: 256
• Date: Tue Jan 4 09:41:45 2000
• Orig file: v2.3.35/linux/drivers/net/arcnet/rfc1051.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.35/linux/drivers/net/arcnet/rfc1051.c linux/drivers/net/arcnet/rfc1051.c
@@ -0,0 +1,255 @@
+/*
+ * Linux ARCnet driver - RFC1051 ("simple" standard) packet encapsulation
+ * 
+ * Written 1994-1999 by Avery Pennarun.
+ * Derived from skeleton.c by Donald Becker.
+ *
+ * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
+ *  for sponsoring the further development of this driver.
+ *
+ * **********************
+ *
+ * The original copyright of skeleton.c was as follows:
+ *
+ * skeleton.c Written 1993 by Donald Becker.
+ * Copyright 1993 United States Government as represented by the
+ * Director, National Security Agency.  This software may only be used
+ * and distributed according to the terms of the GNU Public License as
+ * modified by SRC, incorporated herein by reference.
+ *
+ * **********************
+ *
+ * For more details, see drivers/net/arcnet.c
+ *
+ * **********************
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/if_arp.h>
+#include <net/arp.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/arcdevice.h>
+
+#define VERSION "arcnet: RFC1051 \"simple standard\" (`s') encapsulation support loaded.\n"
+
+
+static unsigned short type_trans(struct sk_buff *skb, struct net_device *dev);
+static void rx(struct net_device *dev, int bufnum,
+	       struct archdr *pkthdr, int length);
+static int build_header(struct sk_buff *skb, unsigned short type,
+			uint8_t daddr);
+static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
+		      int bufnum);
+
+
+struct ArcProto rfc1051_proto =
+{
+	's',
+	XMTU - RFC1051_HDR_SIZE,
+	rx,
+	build_header,
+	prepare_tx
+};
+
+
+void __init arcnet_rfc1051_init(void)
+{
+	arc_proto_map[ARC_P_IP_RFC1051]
+	    = arc_proto_map[ARC_P_ARP_RFC1051]
+	    = &rfc1051_proto;
+
+	/* if someone else already owns the broadcast, we won't take it */
+	if (arc_bcast_proto == arc_proto_default)
+		arc_bcast_proto = &rfc1051_proto;
+
+}
+
+
+#ifdef MODULE
+
+int __init init_module(void)
+{
+	printk(VERSION);
+	arcnet_rfc1051_init();
+	return 0;
+}
+
+void cleanup_module(void)
+{
+	arcnet_unregister_proto(&rfc1051_proto);
+}
+
+#endif				/* MODULE */
+
+
+/*
+ * Determine a packet's protocol ID.
+ * 
+ * With ARCnet we have to convert everything to Ethernet-style stuff.
+ */
+static unsigned short type_trans(struct sk_buff *skb, struct net_device *dev)
+{
+	struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
+	struct archdr *pkt = (struct archdr *) skb->data;
+	struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
+	int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
+
+	/* Pull off the arcnet header. */
+	skb->mac.raw = skb->data;
+	skb_pull(skb, hdr_size);
+
+	if (pkt->hard.dest == 0)
+		skb->pkt_type = PACKET_BROADCAST;
+	else if (dev->flags & IFF_PROMISC) {
+		/* if we're not sending to ourselves :) */
+		if (pkt->hard.dest != dev->dev_addr[0])
+			skb->pkt_type = PACKET_OTHERHOST;
+	}
+	/* now return the protocol number */
+	switch (soft->proto) {
+	case ARC_P_IP_RFC1051:
+		return htons(ETH_P_IP);
+	case ARC_P_ARP_RFC1051:
+		return htons(ETH_P_ARP);
+
+	default:
+		lp->stats.rx_errors++;
+		lp->stats.rx_crc_errors++;
+		return 0;
+	}
+
+	return htons(ETH_P_IP);
+}
+
+
+/* packet receiver */
+static void rx(struct net_device *dev, int bufnum,
+	       struct archdr *pkthdr, int length)
+{
+	struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
+	struct sk_buff *skb;
+	struct archdr *pkt = pkthdr;
+	int ofs;
+
+	BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length);
+
+	if (length >= MinTU)
+		ofs = 512 - length;
+	else
+		ofs = 256 - length;
+
+	skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
+	if (skb == NULL) {
+		BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
+		lp->stats.rx_dropped++;
+		return;
+	}
+	skb_put(skb, length + ARC_HDR_SIZE);
+	skb->dev = dev;
+
+	pkt = (struct archdr *) skb->data;
+
+	/* up to sizeof(pkt->soft) has already been copied from the card */
+	memcpy(pkt, pkthdr, sizeof(struct archdr));
+	if (length > sizeof(pkt->soft))
+		lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
+				      pkt->soft.raw + sizeof(pkt->soft),
+				      length - sizeof(pkt->soft));
+
+	BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
+
+	skb->protocol = type_trans(skb, dev);
+	netif_rx(skb);
+}
+
+
+/*
+ * Create the ARCnet hard/soft headers for RFC1051.
+ */
+static int build_header(struct sk_buff *skb, unsigned short type,
+			uint8_t daddr)
+{
+	struct net_device *dev = skb->dev;
+	struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
+	int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
+	struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
+	struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
+
+	/* set the protocol ID according to RFC1051 */
+	switch (type) {
+	case ETH_P_IP:
+		soft->proto = ARC_P_IP_RFC1051;
+		break;
+	case ETH_P_ARP:
+		soft->proto = ARC_P_ARP_RFC1051;
+		break;
+	default:
+		BUGMSG(D_NORMAL, "RFC1051: 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.  ARCnet does not allow us to change the source address in
+	 * the actual packet sent)
+	 */
+	pkt->hard.source = *dev->dev_addr;
+
+	/* see linux/net/ethernet/eth.c to see where I got the following */
+
+	if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
+		/* 
+		 * FIXME: fill in the last byte of the dest ipaddr here to better
+		 * comply with RFC1051 in "noarp" mode.
+		 */
+		pkt->hard.dest = 0;
+		return hdr_size;
+	}
+	/* otherwise, just fill it in and go! */
+	pkt->hard.dest = daddr;
+
+	return hdr_size;	/* success */
+}
+
+
+static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
+		      int bufnum)
+{
+	struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
+	struct arc_hardware *hard = &pkt->hard;
+	int ofs;
+
+	BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
+	       lp->next_tx, lp->cur_tx, bufnum);
+
+	length -= ARC_HDR_SIZE;	/* hard header is not included in packet length */
+
+	if (length > XMTU) {
+		/* should never happen! other people already check for this. */
+		BUGMSG(D_NORMAL, "Bug!  prepare_tx with size %d (> %d)\n",
+		       length, XMTU);
+		length = XMTU;
+	}
+	if (length > MinTU) {
+		hard->offset[0] = 0;
+		hard->offset[1] = ofs = 512 - length;
+	} else if (length > MTU) {
+		hard->offset[0] = 0;
+		hard->offset[1] = ofs = 512 - length - 3;
+	} else
+		hard->offset[0] = ofs = 256 - length;
+
+	lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
+	lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
+
+	lp->lastload_dest = hard->dest;
+
+	return 1;		/* done */
+}