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268 lines
7.4 KiB
268 lines
7.4 KiB
/* |
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* Linux ARCnet driver - "cap mode" packet encapsulation. |
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* It adds sequence numbers to packets for communicating between a user space |
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* application and the driver. After a transmit it sends a packet with protocol |
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* byte 0 back up to the userspace containing the sequence number of the packet |
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* plus the transmit-status on the ArcNet. |
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* |
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* Written 2002-4 by Esben Nielsen, Vestas Wind Systems A/S |
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* Derived from arc-rawmode.c by Avery Pennarun. |
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* arc-rawmode was in turned based on skeleton.c, see below. |
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* |
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* ********************** |
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* |
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* The original copyright of skeleton.c was as follows: |
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* |
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* skeleton.c Written 1993 by Donald Becker. |
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* Copyright 1993 United States Government as represented by the |
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* Director, National Security Agency. This software may only be used |
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* and distributed according to the terms of the GNU General Public License as |
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* modified by SRC, incorporated herein by reference. |
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* |
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* ********************** |
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* |
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* For more details, see drivers/net/arcnet.c |
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* |
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* ********************** |
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*/ |
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#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt |
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#include <linux/module.h> |
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#include <linux/gfp.h> |
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#include <linux/init.h> |
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#include <linux/if_arp.h> |
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#include <net/arp.h> |
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#include <linux/netdevice.h> |
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#include <linux/skbuff.h> |
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#include "arcdevice.h" |
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/* packet receiver */ |
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static void rx(struct net_device *dev, int bufnum, |
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struct archdr *pkthdr, int length) |
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{ |
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struct arcnet_local *lp = netdev_priv(dev); |
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struct sk_buff *skb; |
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struct archdr *pkt; |
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char *pktbuf, *pkthdrbuf; |
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int ofs; |
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arc_printk(D_DURING, dev, "it's a raw(cap) packet (length=%d)\n", |
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length); |
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if (length >= MinTU) |
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ofs = 512 - length; |
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else |
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ofs = 256 - length; |
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skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC); |
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if (!skb) { |
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dev->stats.rx_dropped++; |
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return; |
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} |
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skb_put(skb, length + ARC_HDR_SIZE + sizeof(int)); |
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skb->dev = dev; |
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skb_reset_mac_header(skb); |
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pkt = (struct archdr *)skb_mac_header(skb); |
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skb_pull(skb, ARC_HDR_SIZE); |
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/* up to sizeof(pkt->soft) has already been copied from the card |
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* squeeze in an int for the cap encapsulation |
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* use these variables to be sure we count in bytes, not in |
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* sizeof(struct archdr) |
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*/ |
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pktbuf = (char *)pkt; |
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pkthdrbuf = (char *)pkthdr; |
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memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto)); |
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memcpy(pktbuf + ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto) + sizeof(int), |
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pkthdrbuf + ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto), |
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sizeof(struct archdr) - ARC_HDR_SIZE - sizeof(pkt->soft.cap.proto)); |
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if (length > sizeof(pkt->soft)) |
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lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft), |
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pkt->soft.raw + sizeof(pkt->soft) |
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+ sizeof(int), |
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length - sizeof(pkt->soft)); |
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if (BUGLVL(D_SKB)) |
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arcnet_dump_skb(dev, skb, "rx"); |
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skb->protocol = cpu_to_be16(ETH_P_ARCNET); |
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netif_rx(skb); |
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} |
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/* Create the ARCnet hard/soft headers for cap mode. |
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* There aren't any soft headers in cap mode - not even the protocol id. |
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*/ |
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static int build_header(struct sk_buff *skb, |
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struct net_device *dev, |
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unsigned short type, |
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uint8_t daddr) |
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{ |
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int hdr_size = ARC_HDR_SIZE; |
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struct archdr *pkt = skb_push(skb, hdr_size); |
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arc_printk(D_PROTO, dev, "Preparing header for cap packet %x.\n", |
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*((int *)&pkt->soft.cap.cookie[0])); |
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/* Set the source hardware address. |
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* |
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* This is pretty pointless for most purposes, but it can help in |
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* debugging. ARCnet does not allow us to change the source address in |
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* the actual packet sent) |
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*/ |
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pkt->hard.source = *dev->dev_addr; |
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/* see linux/net/ethernet/eth.c to see where I got the following */ |
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if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { |
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/* FIXME: fill in the last byte of the dest ipaddr here to |
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* better comply with RFC1051 in "noarp" mode. |
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*/ |
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pkt->hard.dest = 0; |
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return hdr_size; |
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} |
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/* otherwise, just fill it in and go! */ |
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pkt->hard.dest = daddr; |
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return hdr_size; /* success */ |
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} |
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static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, |
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int bufnum) |
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{ |
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struct arcnet_local *lp = netdev_priv(dev); |
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struct arc_hardware *hard = &pkt->hard; |
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int ofs; |
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/* hard header is not included in packet length */ |
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length -= ARC_HDR_SIZE; |
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/* And neither is the cookie field */ |
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length -= sizeof(int); |
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arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n", |
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lp->next_tx, lp->cur_tx, bufnum); |
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arc_printk(D_PROTO, dev, "Sending for cap packet %x.\n", |
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*((int *)&pkt->soft.cap.cookie[0])); |
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if (length > XMTU) { |
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/* should never happen! other people already check for this. */ |
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arc_printk(D_NORMAL, dev, "Bug! prepare_tx with size %d (> %d)\n", |
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length, XMTU); |
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length = XMTU; |
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} |
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if (length > MinTU) { |
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hard->offset[0] = 0; |
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hard->offset[1] = ofs = 512 - length; |
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} else if (length > MTU) { |
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hard->offset[0] = 0; |
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hard->offset[1] = ofs = 512 - length - 3; |
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} else { |
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hard->offset[0] = ofs = 256 - length; |
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} |
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arc_printk(D_DURING, dev, "prepare_tx: length=%d ofs=%d\n", |
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length, ofs); |
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/* Copy the arcnet-header + the protocol byte down: */ |
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lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); |
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lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto, |
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sizeof(pkt->soft.cap.proto)); |
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/* Skip the extra integer we have written into it as a cookie |
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* but write the rest of the message: |
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*/ |
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lp->hw.copy_to_card(dev, bufnum, ofs + 1, |
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((unsigned char *)&pkt->soft.cap.mes), length - 1); |
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lp->lastload_dest = hard->dest; |
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return 1; /* done */ |
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} |
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static int ack_tx(struct net_device *dev, int acked) |
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{ |
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struct arcnet_local *lp = netdev_priv(dev); |
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struct sk_buff *ackskb; |
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struct archdr *ackpkt; |
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int length = sizeof(struct arc_cap); |
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arc_printk(D_DURING, dev, "capmode: ack_tx: protocol: %x: result: %d\n", |
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lp->outgoing.skb->protocol, acked); |
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if (BUGLVL(D_SKB)) |
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arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx"); |
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/* Now alloc a skb to send back up through the layers: */ |
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ackskb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC); |
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if (!ackskb) |
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goto free_outskb; |
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skb_put(ackskb, length + ARC_HDR_SIZE); |
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ackskb->dev = dev; |
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skb_reset_mac_header(ackskb); |
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ackpkt = (struct archdr *)skb_mac_header(ackskb); |
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/* skb_pull(ackskb, ARC_HDR_SIZE); */ |
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skb_copy_from_linear_data(lp->outgoing.skb, ackpkt, |
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ARC_HDR_SIZE + sizeof(struct arc_cap)); |
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ackpkt->soft.cap.proto = 0; /* using protocol 0 for acknowledge */ |
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ackpkt->soft.cap.mes.ack = acked; |
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arc_printk(D_PROTO, dev, "Acknowledge for cap packet %x.\n", |
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*((int *)&ackpkt->soft.cap.cookie[0])); |
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ackskb->protocol = cpu_to_be16(ETH_P_ARCNET); |
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if (BUGLVL(D_SKB)) |
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arcnet_dump_skb(dev, ackskb, "ack_tx_recv"); |
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netif_rx(ackskb); |
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free_outskb: |
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dev_kfree_skb_irq(lp->outgoing.skb); |
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lp->outgoing.proto = NULL; |
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/* We are always finished when in this protocol */ |
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return 0; |
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} |
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static struct ArcProto capmode_proto = { |
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.suffix = 'r', |
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.mtu = XMTU, |
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.rx = rx, |
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.build_header = build_header, |
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.prepare_tx = prepare_tx, |
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.ack_tx = ack_tx |
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}; |
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static int __init capmode_module_init(void) |
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{ |
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int count; |
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pr_info("cap mode (`c') encapsulation support loaded\n"); |
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for (count = 1; count <= 8; count++) |
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if (arc_proto_map[count] == arc_proto_default) |
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arc_proto_map[count] = &capmode_proto; |
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/* for cap mode, we only set the bcast proto if there's no better one */ |
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if (arc_bcast_proto == arc_proto_default) |
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arc_bcast_proto = &capmode_proto; |
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arc_proto_default = &capmode_proto; |
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arc_raw_proto = &capmode_proto; |
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return 0; |
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} |
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static void __exit capmode_module_exit(void) |
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{ |
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arcnet_unregister_proto(&capmode_proto); |
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} |
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module_init(capmode_module_init); |
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module_exit(capmode_module_exit); |
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MODULE_LICENSE("GPL");
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