| /* |
| * 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; |
| |
| arc_printk(D_DURING, dev, "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) { |
| arc_printk(D_NORMAL, dev, "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)); |
| |
| if (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: |
| arc_printk(D_NORMAL, dev, "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; |
| |
| arc_printk(D_DURING, dev, "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. */ |
| arc_printk(D_NORMAL, dev, "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 */ |
| } |