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.
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.
12 * **********************
14 * The original copyright of skeleton.c was as follows:
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.
22 * **********************
24 * For more details, see drivers/net/arcnet.c
26 * **********************
29 #include <linux/module.h>
30 #include <linux/gfp.h>
31 #include <linux/init.h>
32 #include <linux/if_arp.h>
34 #include <linux/netdevice.h>
35 #include <linux/skbuff.h>
36 #include <linux/arcdevice.h>
38 #define VERSION "arcnet: cap mode (`c') encapsulation support loaded.\n"
41 static void rx(struct net_device *dev, int bufnum,
42 struct archdr *pkthdr, int length)
44 struct arcnet_local *lp = netdev_priv(dev);
46 struct archdr *pkt = pkthdr;
47 char *pktbuf, *pkthdrbuf;
50 BUGMSG(D_DURING, "it's a raw(cap) packet (length=%d)\n", length);
57 skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC);
59 BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
60 dev->stats.rx_dropped++;
63 skb_put(skb, length + ARC_HDR_SIZE + sizeof(int));
65 skb_reset_mac_header(skb);
66 pkt = (struct archdr *)skb_mac_header(skb);
67 skb_pull(skb, ARC_HDR_SIZE);
69 /* up to sizeof(pkt->soft) has already been copied from the card
70 * squeeze in an int for the cap encapsulation
71 * use these variables to be sure we count in bytes, not in
72 * sizeof(struct archdr)
75 pkthdrbuf = (char *)pkthdr;
76 memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto));
77 memcpy(pktbuf + ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto) + sizeof(int),
78 pkthdrbuf + ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto),
79 sizeof(struct archdr) - ARC_HDR_SIZE - sizeof(pkt->soft.cap.proto));
81 if (length > sizeof(pkt->soft))
82 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
83 pkt->soft.raw + sizeof(pkt->soft)
85 length - sizeof(pkt->soft));
87 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
89 skb->protocol = cpu_to_be16(ETH_P_ARCNET);
93 /* Create the ARCnet hard/soft headers for cap mode.
94 * There aren't any soft headers in cap mode - not even the protocol id.
96 static int build_header(struct sk_buff *skb,
97 struct net_device *dev,
101 int hdr_size = ARC_HDR_SIZE;
102 struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
104 BUGMSG(D_PROTO, "Preparing header for cap packet %x.\n",
105 *((int *)&pkt->soft.cap.cookie[0]));
107 /* Set the source hardware address.
109 * This is pretty pointless for most purposes, but it can help in
110 * debugging. ARCnet does not allow us to change the source address in
111 * the actual packet sent)
113 pkt->hard.source = *dev->dev_addr;
115 /* see linux/net/ethernet/eth.c to see where I got the following */
117 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
118 /* FIXME: fill in the last byte of the dest ipaddr here to
119 * better comply with RFC1051 in "noarp" mode.
124 /* otherwise, just fill it in and go! */
125 pkt->hard.dest = daddr;
127 return hdr_size; /* success */
130 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
133 struct arcnet_local *lp = netdev_priv(dev);
134 struct arc_hardware *hard = &pkt->hard;
137 /* hard header is not included in packet length */
138 length -= ARC_HDR_SIZE;
139 /* And neither is the cookie field */
140 length -= sizeof(int);
142 BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
143 lp->next_tx, lp->cur_tx, bufnum);
145 BUGMSG(D_PROTO, "Sending for cap packet %x.\n",
146 *((int *)&pkt->soft.cap.cookie[0]));
149 /* should never happen! other people already check for this. */
150 BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n",
154 if (length > MinTU) {
156 hard->offset[1] = ofs = 512 - length;
157 } else if (length > MTU) {
159 hard->offset[1] = ofs = 512 - length - 3;
161 hard->offset[0] = ofs = 256 - length;
164 BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n",
167 /* Copy the arcnet-header + the protocol byte down: */
168 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
169 lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto,
170 sizeof(pkt->soft.cap.proto));
172 /* Skip the extra integer we have written into it as a cookie
173 * but write the rest of the message:
175 lp->hw.copy_to_card(dev, bufnum, ofs + 1,
176 ((unsigned char *)&pkt->soft.cap.mes), length - 1);
178 lp->lastload_dest = hard->dest;
183 static int ack_tx(struct net_device *dev, int acked)
185 struct arcnet_local *lp = netdev_priv(dev);
186 struct sk_buff *ackskb;
187 struct archdr *ackpkt;
188 int length = sizeof(struct arc_cap);
190 BUGMSG(D_DURING, "capmode: ack_tx: protocol: %x: result: %d\n",
191 lp->outgoing.skb->protocol, acked);
193 BUGLVL(D_SKB) arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx");
195 /* Now alloc a skb to send back up through the layers: */
196 ackskb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
197 if (ackskb == NULL) {
198 BUGMSG(D_NORMAL, "Memory squeeze, can't acknowledge.\n");
202 skb_put(ackskb, length + ARC_HDR_SIZE);
205 skb_reset_mac_header(ackskb);
206 ackpkt = (struct archdr *)skb_mac_header(ackskb);
207 /* skb_pull(ackskb, ARC_HDR_SIZE); */
209 skb_copy_from_linear_data(lp->outgoing.skb, ackpkt,
210 ARC_HDR_SIZE + sizeof(struct arc_cap));
211 ackpkt->soft.cap.proto = 0; /* using protocol 0 for acknowledge */
212 ackpkt->soft.cap.mes.ack = acked;
214 BUGMSG(D_PROTO, "Ackknowledge for cap packet %x.\n",
215 *((int *)&ackpkt->soft.cap.cookie[0]));
217 ackskb->protocol = cpu_to_be16(ETH_P_ARCNET);
219 BUGLVL(D_SKB) arcnet_dump_skb(dev, ackskb, "ack_tx_recv");
223 dev_kfree_skb_irq(lp->outgoing.skb);
224 lp->outgoing.proto = NULL; /* We are always finished when in this protocol */
229 static struct ArcProto capmode_proto = {
240 static void arcnet_cap_init(void)
244 for (count = 1; count <= 8; count++)
245 if (arc_proto_map[count] == arc_proto_default)
246 arc_proto_map[count] = &capmode_proto;
248 /* for cap mode, we only set the bcast proto if there's no better one */
249 if (arc_bcast_proto == arc_proto_default)
250 arc_bcast_proto = &capmode_proto;
252 arc_proto_default = &capmode_proto;
253 arc_raw_proto = &capmode_proto;
256 static int __init capmode_module_init(void)
263 static void __exit capmode_module_exit(void)
265 arcnet_unregister_proto(&capmode_proto);
267 module_init(capmode_module_init);
268 module_exit(capmode_module_exit);
270 MODULE_LICENSE("GPL");