/* * 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 #include #include #include #include #include #include #include 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 = (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); /* 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 */ }