drivers/net/arcnet/capmode.c

   1 /*
   2  * Linux ARCnet driver - "cap mode" packet encapsulation.
   3  * It adds sequence numbers to packets for communicating between a user space
   4  * application and the driver. After a transmit it sends a packet with protocol
   5  * byte 0 back up to the userspace containing the sequence number of the packet
   6  * plus the transmit-status on the ArcNet.
   7  *
   8  * Written 2002-4 by Esben Nielsen, Vestas Wind Systems A/S
   9  * Derived from arc-rawmode.c by Avery Pennarun.
  10  * arc-rawmode was in turned based on skeleton.c, see below.
  11  *
  12  * **********************
  13  *
  14  * The original copyright of skeleton.c was as follows:
  15  *
  16  * skeleton.c Written 1993 by Donald Becker.
  17  * Copyright 1993 United States Government as represented by the
  18  * Director, National Security Agency.  This software may only be used
  19  * and distributed according to the terms of the GNU General Public License as
  20  * modified by SRC, incorporated herein by reference.
  21  *
  22  * **********************
  23  *
  24  * For more details, see drivers/net/arcnet.c
  25  *
  26  * **********************
  27  */
  28
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/if_arp.h>
  32 #include <net/arp.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/skbuff.h>
  35 #include <linux/arcdevice.h>
  36
  37 #define VERSION "arcnet: cap mode (`c') encapsulation support loaded.\n"
  38
  39
  40 static void rx(struct net_device *dev, int bufnum,
  41                struct archdr *pkthdr, int length);
  42 static int build_header(struct sk_buff *skb,
  43                         struct net_device *dev,
  44                         unsigned short type,
  45                         uint8_t daddr);
  46 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
  47                       int bufnum);
  48 static int ack_tx(struct net_device *dev, int acked);
  49
  50
  51 static struct ArcProto capmode_proto =
  52 {
  53         'r',
  54         XMTU,
  55         0,
  56         rx,
  57         build_header,
  58         prepare_tx,
  59         NULL,
  60         ack_tx
  61 };
  62
  63
  64 void arcnet_cap_init(void)
  65 {
  66         int count;
  67
  68         for (count = 1; count <= 8; count++)
  69                 if (arc_proto_map[count] == arc_proto_default)
  70                         arc_proto_map[count] = &capmode_proto;
  71
  72         /* for cap mode, we only set the bcast proto if there's no better one */
  73         if (arc_bcast_proto == arc_proto_default)
  74                 arc_bcast_proto = &capmode_proto;
  75
  76         arc_proto_default = &capmode_proto;
  77         arc_raw_proto = &capmode_proto;
  78 }
  79
  80
  81 #ifdef MODULE
  82
  83 <<<<<<< HEAD:drivers/net/arcnet/capmode.c
  84 int __init init_module(void)
  85 =======
  86 static int __init capmode_module_init(void)
  87 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/net/arcnet/capmode.c
  88 {
  89         printk(VERSION);
  90         arcnet_cap_init();
  91         return 0;
  92 }
  93
  94 <<<<<<< HEAD:drivers/net/arcnet/capmode.c
  95 void cleanup_module(void)
  96 =======
  97 static void __exit capmode_module_exit(void)
  98 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/net/arcnet/capmode.c
  99 {
 100         arcnet_unregister_proto(&capmode_proto);
 101 }
 102 <<<<<<< HEAD:drivers/net/arcnet/capmode.c
 103 =======
 104 module_init(capmode_module_init);
 105 module_exit(capmode_module_exit);
 106 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/net/arcnet/capmode.c
 107
 108 MODULE_LICENSE("GPL");
 109 #endif                          /* MODULE */
 110
 111
 112
 113 /* packet receiver */
 114 static void rx(struct net_device *dev, int bufnum,
 115                struct archdr *pkthdr, int length)
 116 {
 117         struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
 118         struct sk_buff *skb;
 119         struct archdr *pkt = pkthdr;
 120         char *pktbuf, *pkthdrbuf;
 121         int ofs;
 122
 123         BUGMSG(D_DURING, "it's a raw(cap) packet (length=%d)\n", length);
 124
 125         if (length >= MinTU)
 126                 ofs = 512 - length;
 127         else
 128                 ofs = 256 - length;
 129
 130         skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC);
 131         if (skb == NULL) {
 132                 BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
 133                 lp->stats.rx_dropped++;
 134                 return;
 135         }
 136         skb_put(skb, length + ARC_HDR_SIZE + sizeof(int));
 137         skb->dev = dev;
 138         skb_reset_mac_header(skb);
 139         pkt = (struct archdr *)skb_mac_header(skb);
 140         skb_pull(skb, ARC_HDR_SIZE);
 141
 142         /* up to sizeof(pkt->soft) has already been copied from the card */
 143         /* squeeze in an int for the cap encapsulation */
 144
 145         /* use these variables to be sure we count in bytes, not in
 146            sizeof(struct archdr) */
 147         pktbuf=(char*)pkt;
 148         pkthdrbuf=(char*)pkthdr;
 149         memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto));
 150         memcpy(pktbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto)+sizeof(int),
 151                pkthdrbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto),
 152                sizeof(struct archdr)-ARC_HDR_SIZE-sizeof(pkt->soft.cap.proto));
 153
 154         if (length > sizeof(pkt->soft))
 155                 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
 156                                       pkt->soft.raw + sizeof(pkt->soft)
 157                                       + sizeof(int),
 158                                       length - sizeof(pkt->soft));
 159
 160         BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
 161
 162         skb->protocol = __constant_htons(ETH_P_ARCNET);
 163 ;
 164         netif_rx(skb);
 165         dev->last_rx = jiffies;
 166 }
 167
 168
 169 /*
 170  * Create the ARCnet hard/soft headers for cap mode.
 171  * There aren't any soft headers in cap mode - not even the protocol id.
 172  */
 173 static int build_header(struct sk_buff *skb,
 174                         struct net_device *dev,
 175                         unsigned short type,
 176                         uint8_t daddr)
 177 {
 178         int hdr_size = ARC_HDR_SIZE;
 179         struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
 180
 181         BUGMSG(D_PROTO, "Preparing header for cap packet %x.\n",
 182                *((int*)&pkt->soft.cap.cookie[0]));
 183         /*
 184          * Set the source hardware address.
 185          *
 186          * This is pretty pointless for most purposes, but it can help in
 187          * debugging.  ARCnet does not allow us to change the source address in
 188          * the actual packet sent)
 189          */
 190         pkt->hard.source = *dev->dev_addr;
 191
 192         /* see linux/net/ethernet/eth.c to see where I got the following */
 193
 194         if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
 195                 /*
 196                  * FIXME: fill in the last byte of the dest ipaddr here to better
 197                  * comply with RFC1051 in "noarp" mode.
 198                  */
 199                 pkt->hard.dest = 0;
 200                 return hdr_size;
 201         }
 202         /* otherwise, just fill it in and go! */
 203         pkt->hard.dest = daddr;
 204
 205         return hdr_size;        /* success */
 206 }
 207
 208
 209 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
 210                       int bufnum)
 211 {
 212         struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
 213         struct arc_hardware *hard = &pkt->hard;
 214         int ofs;
 215
 216
 217         /* hard header is not included in packet length */
 218         length -= ARC_HDR_SIZE;
 219         /* And neither is the cookie field */
 220         length -= sizeof(int);
 221
 222         BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
 223                lp->next_tx, lp->cur_tx, bufnum);
 224
 225         BUGMSG(D_PROTO, "Sending for cap packet %x.\n",
 226                *((int*)&pkt->soft.cap.cookie[0]));
 227
 228         if (length > XMTU) {
 229                 /* should never happen! other people already check for this. */
 230                 BUGMSG(D_NORMAL, "Bug!  prepare_tx with size %d (> %d)\n",
 231                        length, XMTU);
 232                 length = XMTU;
 233         }
 234         if (length > MinTU) {
 235                 hard->offset[0] = 0;
 236                 hard->offset[1] = ofs = 512 - length;
 237         } else if (length > MTU) {
 238                 hard->offset[0] = 0;
 239                 hard->offset[1] = ofs = 512 - length - 3;
 240         } else
 241                 hard->offset[0] = ofs = 256 - length;
 242
 243         BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n",
 244                length,ofs);
 245
 246         // Copy the arcnet-header + the protocol byte down:
 247         lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
 248         lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto,
 249                             sizeof(pkt->soft.cap.proto));
 250
 251         // Skip the extra integer we have written into it as a cookie
 252         // but write the rest of the message:
 253         lp->hw.copy_to_card(dev, bufnum, ofs+1,
 254                             ((unsigned char*)&pkt->soft.cap.mes),length-1);
 255
 256         lp->lastload_dest = hard->dest;
 257
 258         return 1;               /* done */
 259 }
 260
 261
 262 static int ack_tx(struct net_device *dev, int acked)
 263 {
 264   struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
 265   struct sk_buff *ackskb;
 266   struct archdr *ackpkt;
 267   int length=sizeof(struct arc_cap);
 268
 269   BUGMSG(D_DURING, "capmode: ack_tx: protocol: %x: result: %d\n",
 270          lp->outgoing.skb->protocol, acked);
 271
 272   BUGLVL(D_SKB) arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx");
 273
 274   /* Now alloc a skb to send back up through the layers: */
 275   ackskb = alloc_skb(length + ARC_HDR_SIZE , GFP_ATOMIC);
 276   if (ackskb == NULL) {
 277           BUGMSG(D_NORMAL, "Memory squeeze, can't acknowledge.\n");
 278           goto free_outskb;
 279   }
 280
 281   skb_put(ackskb, length + ARC_HDR_SIZE );
 282   ackskb->dev = dev;
 283
 284   skb_reset_mac_header(ackskb);
 285   ackpkt = (struct archdr *)skb_mac_header(ackskb);
 286   /* skb_pull(ackskb, ARC_HDR_SIZE); */
 287
 288
 289   skb_copy_from_linear_data(lp->outgoing.skb, ackpkt,
 290                 ARC_HDR_SIZE + sizeof(struct arc_cap));
 291   ackpkt->soft.cap.proto=0; /* using protocol 0 for acknowledge */
 292   ackpkt->soft.cap.mes.ack=acked;
 293
 294   BUGMSG(D_PROTO, "Ackknowledge for cap packet %x.\n",
 295          *((int*)&ackpkt->soft.cap.cookie[0]));
 296
 297   ackskb->protocol = __constant_htons(ETH_P_ARCNET);
 298
 299   BUGLVL(D_SKB) arcnet_dump_skb(dev, ackskb, "ack_tx_recv");
 300   netif_rx(ackskb);
 301
 302  free_outskb:
 303   dev_kfree_skb_irq(lp->outgoing.skb);
 304   lp->outgoing.proto = NULL; /* We are always finished when in this protocol */
 305
 306   return 0;
 307 }