diff options
Diffstat (limited to 'drivers/net/arcnet/rfc1051.c')
| -rw-r--r-- | drivers/net/arcnet/rfc1051.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/drivers/net/arcnet/rfc1051.c b/drivers/net/arcnet/rfc1051.c new file mode 100644 index 000000000..a7752a5b6 --- /dev/null +++ b/drivers/net/arcnet/rfc1051.c @@ -0,0 +1,242 @@ +/* + * 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 + * + * ********************** + */ + +#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt + +#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 "arcdevice.h" + +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) +{ + pr_info("%s\n", "RFC1051 \"simple standard\" (`s') encapsulation support loaded"); + + 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) { + 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 = 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); + + /* hard header is not included in packet length */ + length -= ARC_HDR_SIZE; + + 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 */ +} |