--- /dev/null
+/*
+ * Linux ARCnet driver - "cap mode" packet encapsulation.
+ * It adds sequence numbers to packets for communicating between a user space
+ * application and the driver. After a transmit it sends a packet with protocol
+ * byte 0 back up to the userspace containing the sequence number of the packet
+ * plus the transmit-status on the ArcNet.
+ *
+ * Written 2002-4 by Esben Nielsen, Vestas Wind Systems A/S
+ * Derived from arc-rawmode.c by Avery Pennarun.
+ * arc-rawmode was in turned based on skeleton.c, see below.
+ *
+ * **********************
+ *
+ * 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: cap mode (`c') encapsulation support loaded.\n"
+
+/* 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;
+ char *pktbuf, *pkthdrbuf;
+ int ofs;
+
+ BUGMSG(D_DURING, "it's a raw(cap) packet (length=%d)\n", length);
+
+ if (length >= MinTU)
+ ofs = 512 - length;
+ else
+ ofs = 256 - length;
+
+ skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), 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 + sizeof(int));
+ skb->dev = dev;
+ skb_reset_mac_header(skb);
+ pkt = (struct archdr *)skb_mac_header(skb);
+ skb_pull(skb, ARC_HDR_SIZE);
+
+ /* up to sizeof(pkt->soft) has already been copied from the card */
+ /* squeeze in an int for the cap encapsulation */
+
+ /* use these variables to be sure we count in bytes, not in
+ sizeof(struct archdr) */
+ pktbuf=(char*)pkt;
+ pkthdrbuf=(char*)pkthdr;
+ memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto));
+ memcpy(pktbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto)+sizeof(int),
+ pkthdrbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto),
+ sizeof(struct archdr)-ARC_HDR_SIZE-sizeof(pkt->soft.cap.proto));
+
+ if (length > sizeof(pkt->soft))
+ lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
+ pkt->soft.raw + sizeof(pkt->soft)
+ + sizeof(int),
+ length - sizeof(pkt->soft));
+
+ BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
+
+ skb->protocol = cpu_to_be16(ETH_P_ARCNET);
+ netif_rx(skb);
+}
+
+
+/*
+ * Create the ARCnet hard/soft headers for cap mode.
+ * There aren't any soft headers in cap mode - not even the protocol id.
+ */
+static int build_header(struct sk_buff *skb,
+ struct net_device *dev,
+ unsigned short type,
+ uint8_t daddr)
+{
+ int hdr_size = ARC_HDR_SIZE;
+ struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
+
+ BUGMSG(D_PROTO, "Preparing header for cap packet %x.\n",
+ *((int*)&pkt->soft.cap.cookie[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;
+
+
+ /* hard header is not included in packet length */
+ length -= ARC_HDR_SIZE;
+ /* And neither is the cookie field */
+ length -= sizeof(int);
+
+ BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
+ lp->next_tx, lp->cur_tx, bufnum);
+
+ BUGMSG(D_PROTO, "Sending for cap packet %x.\n",
+ *((int*)&pkt->soft.cap.cookie[0]));
+
+ 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;
+
+ BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n",
+ length,ofs);
+
+ /* Copy the arcnet-header + the protocol byte down: */
+ lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
+ lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto,
+ sizeof(pkt->soft.cap.proto));
+
+ /* Skip the extra integer we have written into it as a cookie
+ but write the rest of the message: */
+ lp->hw.copy_to_card(dev, bufnum, ofs+1,
+ ((unsigned char*)&pkt->soft.cap.mes),length-1);
+
+ lp->lastload_dest = hard->dest;
+
+ return 1; /* done */
+}
+
+static int ack_tx(struct net_device *dev, int acked)
+{
+ struct arcnet_local *lp = netdev_priv(dev);
+ struct sk_buff *ackskb;
+ struct archdr *ackpkt;
+ int length=sizeof(struct arc_cap);
+
+ BUGMSG(D_DURING, "capmode: ack_tx: protocol: %x: result: %d\n",
+ lp->outgoing.skb->protocol, acked);
+
+ BUGLVL(D_SKB) arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx");
+
+ /* Now alloc a skb to send back up through the layers: */
+ ackskb = alloc_skb(length + ARC_HDR_SIZE , GFP_ATOMIC);
+ if (ackskb == NULL) {
+ BUGMSG(D_NORMAL, "Memory squeeze, can't acknowledge.\n");
+ goto free_outskb;
+ }
+
+ skb_put(ackskb, length + ARC_HDR_SIZE );
+ ackskb->dev = dev;
+
+ skb_reset_mac_header(ackskb);
+ ackpkt = (struct archdr *)skb_mac_header(ackskb);
+ /* skb_pull(ackskb, ARC_HDR_SIZE); */
+
+ skb_copy_from_linear_data(lp->outgoing.skb, ackpkt,
+ ARC_HDR_SIZE + sizeof(struct arc_cap));
+ ackpkt->soft.cap.proto = 0; /* using protocol 0 for acknowledge */
+ ackpkt->soft.cap.mes.ack=acked;
+
+ BUGMSG(D_PROTO, "Ackknowledge for cap packet %x.\n",
+ *((int*)&ackpkt->soft.cap.cookie[0]));
+
+ ackskb->protocol = cpu_to_be16(ETH_P_ARCNET);
+
+ BUGLVL(D_SKB) arcnet_dump_skb(dev, ackskb, "ack_tx_recv");
+ netif_rx(ackskb);
+
+free_outskb:
+ dev_kfree_skb_irq(lp->outgoing.skb);
+ lp->outgoing.proto = NULL; /* We are always finished when in this protocol */
+
+ return 0;
+}
+
+static struct ArcProto capmode_proto =
+{
+ 'r',
+ XMTU,
+ 0,
+ rx,
+ build_header,
+ prepare_tx,
+ NULL,
+ ack_tx
+};
+
+static void arcnet_cap_init(void)
+{
+ int count;
+
+ for (count = 1; count <= 8; count++)
+ if (arc_proto_map[count] == arc_proto_default)
+ arc_proto_map[count] = &capmode_proto;
+
+ /* for cap mode, we only set the bcast proto if there's no better one */
+ if (arc_bcast_proto == arc_proto_default)
+ arc_bcast_proto = &capmode_proto;
+
+ arc_proto_default = &capmode_proto;
+ arc_raw_proto = &capmode_proto;
+}
+
+static int __init capmode_module_init(void)
+{
+ printk(VERSION);
+ arcnet_cap_init();
+ return 0;
+}
+
+static void __exit capmode_module_exit(void)
+{
+ arcnet_unregister_proto(&capmode_proto);
+}
+module_init(capmode_module_init);
+module_exit(capmode_module_exit);
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff