--- /dev/null
+/*
+ * 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 General Public License as
+ * modified by SRC, incorporated herein by reference.
+ *
+ * **********************
+ *
+ * For more details, see drivers/net/arcnet.c
+ *
+ * **********************
+ */
+#include <linux/module.h>
+#include <linux/gfp.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 __be16 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, struct net_device *dev,
+ unsigned short type, uint8_t daddr);
+static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
+ int bufnum);
+
+
+static struct ArcProto rfc1051_proto =
+{
+ .suffix = 's',
+ .mtu = XMTU - RFC1051_HDR_SIZE,
+ .is_ip = 1,
+ .rx = rx,
+ .build_header = build_header,
+ .prepare_tx = prepare_tx,
+ .continue_tx = NULL,
+ .ack_tx = NULL
+};
+
+
+static int __init arcnet_rfc1051_init(void)
+{
+ printk(VERSION);
+
+ 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;
+
+ return 0;
+}
+
+static void __exit arcnet_rfc1051_exit(void)
+{
+ arcnet_unregister_proto(&rfc1051_proto);
+}
+
+module_init(arcnet_rfc1051_init);
+module_exit(arcnet_rfc1051_exit);
+
+MODULE_LICENSE("GPL");
+
+/*
+ * Determine a packet's protocol ID.
+ *
+ * With ARCnet we have to convert everything to Ethernet-style stuff.
+ */
+static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
+{
+ 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_reset_mac_header(skb);
+ 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:
+ dev->stats.rx_errors++;
+ dev->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 = netdev_priv(dev);
+ 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");
+ dev->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, struct net_device *dev,
+ unsigned short type, uint8_t daddr)
+{
+ 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);
+ dev->stats.tx_errors++;
+ dev->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 = netdev_priv(dev);
+ 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 */
+}
Code Review / kvmfornfv.git / blobdiff