Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Linux ARCnet driver - "raw mode" packet encapsulation (no soft headers) |
| 3 | * |
| 4 | * Written 1994-1999 by Avery Pennarun. |
| 5 | * Derived from skeleton.c by Donald Becker. |
| 6 | * |
| 7 | * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com) |
| 8 | * for sponsoring the further development of this driver. |
| 9 | * |
| 10 | * ********************** |
| 11 | * |
| 12 | * The original copyright of skeleton.c was as follows: |
| 13 | * |
| 14 | * skeleton.c Written 1993 by Donald Becker. |
| 15 | * Copyright 1993 United States Government as represented by the |
| 16 | * Director, National Security Agency. This software may only be used |
| 17 | * and distributed according to the terms of the GNU General Public License as |
| 18 | * modified by SRC, incorporated herein by reference. |
| 19 | * |
| 20 | * ********************** |
| 21 | * |
| 22 | * For more details, see drivers/net/arcnet.c |
| 23 | * |
| 24 | * ********************** |
| 25 | */ |
| 26 | |
| 27 | #include <linux/module.h> |
| 28 | #include <linux/init.h> |
| 29 | #include <linux/if_arp.h> |
| 30 | #include <net/arp.h> |
| 31 | #include <linux/netdevice.h> |
| 32 | #include <linux/skbuff.h> |
| 33 | #include <linux/arcdevice.h> |
| 34 | |
| 35 | #define VERSION "arcnet: raw mode (`r') encapsulation support loaded.\n" |
| 36 | |
| 37 | |
| 38 | static void rx(struct net_device *dev, int bufnum, |
| 39 | struct archdr *pkthdr, int length); |
| 40 | static int build_header(struct sk_buff *skb, struct net_device *dev, |
| 41 | unsigned short type, uint8_t daddr); |
| 42 | static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, |
| 43 | int bufnum); |
| 44 | |
Adrian Bunk | f03aa2d | 2006-01-14 03:10:22 +0100 | [diff] [blame^] | 45 | static struct ArcProto rawmode_proto = |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | { |
| 47 | .suffix = 'r', |
| 48 | .mtu = XMTU, |
| 49 | .rx = rx, |
| 50 | .build_header = build_header, |
| 51 | .prepare_tx = prepare_tx, |
| 52 | .continue_tx = NULL, |
| 53 | .ack_tx = NULL |
| 54 | }; |
| 55 | |
| 56 | |
| 57 | static int __init arcnet_raw_init(void) |
| 58 | { |
| 59 | int count; |
| 60 | |
| 61 | printk(VERSION); |
| 62 | |
| 63 | for (count = 0; count < 256; count++) |
| 64 | if (arc_proto_map[count] == arc_proto_default) |
| 65 | arc_proto_map[count] = &rawmode_proto; |
| 66 | |
| 67 | /* for raw mode, we only set the bcast proto if there's no better one */ |
| 68 | if (arc_bcast_proto == arc_proto_default) |
| 69 | arc_bcast_proto = &rawmode_proto; |
| 70 | |
| 71 | arc_proto_default = &rawmode_proto; |
| 72 | return 0; |
| 73 | } |
| 74 | |
| 75 | static void __exit arcnet_raw_exit(void) |
| 76 | { |
| 77 | arcnet_unregister_proto(&rawmode_proto); |
| 78 | } |
| 79 | |
| 80 | module_init(arcnet_raw_init); |
| 81 | module_exit(arcnet_raw_exit); |
| 82 | |
| 83 | MODULE_LICENSE("GPL"); |
| 84 | |
| 85 | |
| 86 | /* packet receiver */ |
| 87 | static void rx(struct net_device *dev, int bufnum, |
| 88 | struct archdr *pkthdr, int length) |
| 89 | { |
| 90 | struct arcnet_local *lp = dev->priv; |
| 91 | struct sk_buff *skb; |
| 92 | struct archdr *pkt = pkthdr; |
| 93 | int ofs; |
| 94 | |
| 95 | BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length); |
| 96 | |
| 97 | if (length >= MinTU) |
| 98 | ofs = 512 - length; |
| 99 | else |
| 100 | ofs = 256 - length; |
| 101 | |
| 102 | skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC); |
| 103 | if (skb == NULL) { |
| 104 | BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n"); |
| 105 | lp->stats.rx_dropped++; |
| 106 | return; |
| 107 | } |
| 108 | skb_put(skb, length + ARC_HDR_SIZE); |
| 109 | skb->dev = dev; |
| 110 | |
| 111 | pkt = (struct archdr *) skb->data; |
| 112 | |
| 113 | skb->mac.raw = skb->data; |
| 114 | skb_pull(skb, ARC_HDR_SIZE); |
| 115 | |
| 116 | /* up to sizeof(pkt->soft) has already been copied from the card */ |
| 117 | memcpy(pkt, pkthdr, sizeof(struct archdr)); |
| 118 | if (length > sizeof(pkt->soft)) |
| 119 | lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft), |
| 120 | pkt->soft.raw + sizeof(pkt->soft), |
| 121 | length - sizeof(pkt->soft)); |
| 122 | |
| 123 | BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx"); |
| 124 | |
| 125 | skb->protocol = __constant_htons(ETH_P_ARCNET); |
| 126 | ; |
| 127 | netif_rx(skb); |
| 128 | dev->last_rx = jiffies; |
| 129 | } |
| 130 | |
| 131 | |
| 132 | /* |
| 133 | * Create the ARCnet hard/soft headers for raw mode. |
| 134 | * There aren't any soft headers in raw mode - not even the protocol id. |
| 135 | */ |
| 136 | static int build_header(struct sk_buff *skb, struct net_device *dev, |
| 137 | unsigned short type, uint8_t daddr) |
| 138 | { |
| 139 | int hdr_size = ARC_HDR_SIZE; |
| 140 | struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size); |
| 141 | |
| 142 | /* |
| 143 | * Set the source hardware address. |
| 144 | * |
| 145 | * This is pretty pointless for most purposes, but it can help in |
| 146 | * debugging. ARCnet does not allow us to change the source address in |
| 147 | * the actual packet sent) |
| 148 | */ |
| 149 | pkt->hard.source = *dev->dev_addr; |
| 150 | |
| 151 | /* see linux/net/ethernet/eth.c to see where I got the following */ |
| 152 | |
| 153 | if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { |
| 154 | /* |
| 155 | * FIXME: fill in the last byte of the dest ipaddr here to better |
| 156 | * comply with RFC1051 in "noarp" mode. |
| 157 | */ |
| 158 | pkt->hard.dest = 0; |
| 159 | return hdr_size; |
| 160 | } |
| 161 | /* otherwise, just fill it in and go! */ |
| 162 | pkt->hard.dest = daddr; |
| 163 | |
| 164 | return hdr_size; /* success */ |
| 165 | } |
| 166 | |
| 167 | |
| 168 | static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, |
| 169 | int bufnum) |
| 170 | { |
| 171 | struct arcnet_local *lp = dev->priv; |
| 172 | struct arc_hardware *hard = &pkt->hard; |
| 173 | int ofs; |
| 174 | |
| 175 | BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n", |
| 176 | lp->next_tx, lp->cur_tx, bufnum); |
| 177 | |
| 178 | length -= ARC_HDR_SIZE; /* hard header is not included in packet length */ |
| 179 | |
| 180 | if (length > XMTU) { |
| 181 | /* should never happen! other people already check for this. */ |
| 182 | BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n", |
| 183 | length, XMTU); |
| 184 | length = XMTU; |
| 185 | } |
| 186 | if (length > MinTU) { |
| 187 | hard->offset[0] = 0; |
| 188 | hard->offset[1] = ofs = 512 - length; |
| 189 | } else if (length > MTU) { |
| 190 | hard->offset[0] = 0; |
| 191 | hard->offset[1] = ofs = 512 - length - 3; |
| 192 | } else |
| 193 | hard->offset[0] = ofs = 256 - length; |
| 194 | |
| 195 | BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n", |
| 196 | length,ofs); |
| 197 | |
| 198 | lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); |
| 199 | lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length); |
| 200 | |
| 201 | lp->lastload_dest = hard->dest; |
| 202 | |
| 203 | return 1; /* done */ |
| 204 | } |