--- /dev/null
+/*
+ * Linux ARCnet driver - RFC1201 (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
+ *
+ * **********************
+ */
+#include <linux/gfp.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/if_arp.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/arcdevice.h>
+
+MODULE_LICENSE("GPL");
+#define VERSION "arcnet: RFC1201 \"standard\" (`a') encapsulation support loaded.\n"
+
+
+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 int continue_tx(struct net_device *dev, int bufnum);
+
+static struct ArcProto rfc1201_proto =
+{
+ .suffix = 'a',
+ .mtu = 1500, /* could be more, but some receivers can't handle it... */
+ .is_ip = 1, /* This is for sending IP and ARP packages */
+ .rx = rx,
+ .build_header = build_header,
+ .prepare_tx = prepare_tx,
+ .continue_tx = continue_tx,
+ .ack_tx = NULL
+};
+
+
+static int __init arcnet_rfc1201_init(void)
+{
+ printk(VERSION);
+
+ arc_proto_map[ARC_P_IP]
+ = arc_proto_map[ARC_P_IPV6]
+ = arc_proto_map[ARC_P_ARP]
+ = arc_proto_map[ARC_P_RARP]
+ = arc_proto_map[ARC_P_IPX]
+ = arc_proto_map[ARC_P_NOVELL_EC]
+ = &rfc1201_proto;
+
+ /* if someone else already owns the broadcast, we won't take it */
+ if (arc_bcast_proto == arc_proto_default)
+ arc_bcast_proto = &rfc1201_proto;
+
+ return 0;
+}
+
+static void __exit arcnet_rfc1201_exit(void)
+{
+ arcnet_unregister_proto(&rfc1201_proto);
+}
+
+module_init(arcnet_rfc1201_init);
+module_exit(arcnet_rfc1201_exit);
+
+/*
+ * 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_rfc1201 *soft = &pkt->soft.rfc1201;
+ int hdr_size = ARC_HDR_SIZE + RFC1201_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:
+ return htons(ETH_P_IP);
+ case ARC_P_IPV6:
+ return htons(ETH_P_IPV6);
+ case ARC_P_ARP:
+ return htons(ETH_P_ARP);
+ case ARC_P_RARP:
+ return htons(ETH_P_RARP);
+
+ case ARC_P_IPX:
+ case ARC_P_NOVELL_EC:
+ return htons(ETH_P_802_3);
+ 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;
+ struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201;
+ int saddr = pkt->hard.source, ofs;
+ struct Incoming *in = &lp->rfc1201.incoming[saddr];
+
+ BUGMSG(D_DURING, "it's an RFC1201 packet (length=%d)\n", length);
+
+ if (length >= MinTU)
+ ofs = 512 - length;
+ else
+ ofs = 256 - length;
+
+ if (soft->split_flag == 0xFF) { /* Exception Packet */
+ if (length >= 4 + RFC1201_HDR_SIZE)
+ BUGMSG(D_DURING, "compensating for exception packet\n");
+ else {
+ BUGMSG(D_EXTRA, "short RFC1201 exception packet from %02Xh",
+ saddr);
+ return;
+ }
+
+ /* skip over 4-byte junkola */
+ length -= 4;
+ ofs += 4;
+ lp->hw.copy_from_card(dev, bufnum, 512 - length,
+ soft, sizeof(pkt->soft));
+ }
+ if (!soft->split_flag) { /* not split */
+ BUGMSG(D_RX, "incoming is not split (splitflag=%d)\n",
+ soft->split_flag);
+
+ if (in->skb) { /* already assembling one! */
+ BUGMSG(D_EXTRA, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
+ in->sequence, soft->split_flag, soft->sequence);
+ lp->rfc1201.aborted_seq = soft->sequence;
+ dev_kfree_skb_irq(in->skb);
+ dev->stats.rx_errors++;
+ dev->stats.rx_missed_errors++;
+ in->skb = NULL;
+ }
+ in->sequence = soft->sequence;
+
+ skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
+ if (skb == NULL) {
+ BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
+ dev->stats.rx_dropped++;
+ return;
+ }
+ skb_put(skb, length + ARC_HDR_SIZE);
+ skb->dev = dev;
+
+ pkt = (struct archdr *) skb->data;
+ soft = &pkt->soft.rfc1201;
+
+ /* 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));
+
+ /*
+ * ARP packets have problems when sent from some DOS systems: the
+ * source address is always 0! So we take the hardware source addr
+ * (which is impossible to fumble) and insert it ourselves.
+ */
+ if (soft->proto == ARC_P_ARP) {
+ struct arphdr *arp = (struct arphdr *) soft->payload;
+
+ /* make sure addresses are the right length */
+ if (arp->ar_hln == 1 && arp->ar_pln == 4) {
+ uint8_t *cptr = (uint8_t *) arp + sizeof(struct arphdr);
+
+ if (!*cptr) { /* is saddr = 00? */
+ BUGMSG(D_EXTRA,
+ "ARP source address was 00h, set to %02Xh.\n",
+ saddr);
+ dev->stats.rx_crc_errors++;
+ *cptr = saddr;
+ } else {
+ BUGMSG(D_DURING, "ARP source address (%Xh) is fine.\n",
+ *cptr);
+ }
+ } else {
+ BUGMSG(D_NORMAL, "funny-shaped ARP packet. (%Xh, %Xh)\n",
+ arp->ar_hln, arp->ar_pln);
+ dev->stats.rx_errors++;
+ dev->stats.rx_crc_errors++;
+ }
+ }
+ BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
+
+ skb->protocol = type_trans(skb, dev);
+ netif_rx(skb);
+ } else { /* split packet */
+ /*
+ * NOTE: MSDOS ARP packet correction should only need to apply to
+ * unsplit packets, since ARP packets are so short.
+ *
+ * My interpretation of the RFC1201 document is that if a packet is
+ * received out of order, the entire assembly process should be
+ * aborted.
+ *
+ * The RFC also mentions "it is possible for successfully received
+ * packets to be retransmitted." As of 0.40 all previously received
+ * packets are allowed, not just the most recent one.
+ *
+ * We allow multiple assembly processes, one for each ARCnet card
+ * possible on the network. Seems rather like a waste of memory,
+ * but there's no other way to be reliable.
+ */
+
+ BUGMSG(D_RX, "packet is split (splitflag=%d, seq=%d)\n",
+ soft->split_flag, in->sequence);
+
+ if (in->skb && in->sequence != soft->sequence) {
+ BUGMSG(D_EXTRA, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
+ saddr, in->sequence, soft->sequence,
+ soft->split_flag);
+ dev_kfree_skb_irq(in->skb);
+ in->skb = NULL;
+ dev->stats.rx_errors++;
+ dev->stats.rx_missed_errors++;
+ in->lastpacket = in->numpackets = 0;
+ }
+ if (soft->split_flag & 1) { /* first packet in split */
+ BUGMSG(D_RX, "brand new splitpacket (splitflag=%d)\n",
+ soft->split_flag);
+ if (in->skb) { /* already assembling one! */
+ BUGMSG(D_EXTRA, "aborting previous (seq=%d) assembly "
+ "(splitflag=%d, seq=%d)\n",
+ in->sequence, soft->split_flag,
+ soft->sequence);
+ dev->stats.rx_errors++;
+ dev->stats.rx_missed_errors++;
+ dev_kfree_skb_irq(in->skb);
+ }
+ in->sequence = soft->sequence;
+ in->numpackets = ((unsigned) soft->split_flag >> 1) + 2;
+ in->lastpacket = 1;
+
+ if (in->numpackets > 16) {
+ BUGMSG(D_EXTRA, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
+ soft->split_flag);
+ lp->rfc1201.aborted_seq = soft->sequence;
+ dev->stats.rx_errors++;
+ dev->stats.rx_length_errors++;
+ return;
+ }
+ in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
+ GFP_ATOMIC);
+ if (skb == NULL) {
+ BUGMSG(D_NORMAL, "(split) memory squeeze, dropping packet.\n");
+ lp->rfc1201.aborted_seq = soft->sequence;
+ dev->stats.rx_dropped++;
+ return;
+ }
+ skb->dev = dev;
+ pkt = (struct archdr *) skb->data;
+ soft = &pkt->soft.rfc1201;
+
+ memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
+ skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
+
+ soft->split_flag = 0; /* end result won't be split */
+ } else { /* not first packet */
+ int packetnum = ((unsigned) soft->split_flag >> 1) + 1;
+
+ /*
+ * if we're not assembling, there's no point trying to
+ * continue.
+ */
+ if (!in->skb) {
+ if (lp->rfc1201.aborted_seq != soft->sequence) {
+ BUGMSG(D_EXTRA, "can't continue split without starting "
+ "first! (splitflag=%d, seq=%d, aborted=%d)\n",
+ soft->split_flag, soft->sequence,
+ lp->rfc1201.aborted_seq);
+ dev->stats.rx_errors++;
+ dev->stats.rx_missed_errors++;
+ }
+ return;
+ }
+ in->lastpacket++;
+ if (packetnum != in->lastpacket) { /* not the right flag! */
+ /* harmless duplicate? ignore. */
+ if (packetnum <= in->lastpacket - 1) {
+ BUGMSG(D_EXTRA, "duplicate splitpacket ignored! (splitflag=%d)\n",
+ soft->split_flag);
+ dev->stats.rx_errors++;
+ dev->stats.rx_frame_errors++;
+ return;
+ }
+ /* "bad" duplicate, kill reassembly */
+ BUGMSG(D_EXTRA, "out-of-order splitpacket, reassembly "
+ "(seq=%d) aborted (splitflag=%d, seq=%d)\n",
+ in->sequence, soft->split_flag, soft->sequence);
+ lp->rfc1201.aborted_seq = soft->sequence;
+ dev_kfree_skb_irq(in->skb);
+ in->skb = NULL;
+ dev->stats.rx_errors++;
+ dev->stats.rx_missed_errors++;
+ in->lastpacket = in->numpackets = 0;
+ return;
+ }
+ pkt = (struct archdr *) in->skb->data;
+ soft = &pkt->soft.rfc1201;
+ }
+
+ skb = in->skb;
+
+ lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE,
+ skb->data + skb->len,
+ length - RFC1201_HDR_SIZE);
+ skb_put(skb, length - RFC1201_HDR_SIZE);
+
+ /* are we done? */
+ if (in->lastpacket == in->numpackets) {
+ in->skb = NULL;
+ in->lastpacket = in->numpackets = 0;
+
+ BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (unsplit)\n",
+ skb->len, pkt->hard.source);
+ BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (split)\n",
+ skb->len, pkt->hard.source);
+ 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 RFC1201. */
+static int build_header(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type, uint8_t daddr)
+{
+ struct arcnet_local *lp = netdev_priv(dev);
+ int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
+ struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
+ struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
+
+ /* set the protocol ID according to RFC1201 */
+ switch (type) {
+ case ETH_P_IP:
+ soft->proto = ARC_P_IP;
+ break;
+ case ETH_P_IPV6:
+ soft->proto = ARC_P_IPV6;
+ break;
+ case ETH_P_ARP:
+ soft->proto = ARC_P_ARP;
+ break;
+ case ETH_P_RARP:
+ soft->proto = ARC_P_RARP;
+ break;
+ case ETH_P_IPX:
+ case ETH_P_802_3:
+ case ETH_P_802_2:
+ soft->proto = ARC_P_IPX;
+ break;
+ case ETH_P_ATALK:
+ soft->proto = ARC_P_ATALK;
+ break;
+ default:
+ BUGMSG(D_NORMAL, "RFC1201: 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;
+
+ soft->sequence = htons(lp->rfc1201.sequence++);
+ soft->split_flag = 0; /* split packets are done elsewhere */
+
+ /* 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. For now, always broadcasting
+ * will probably at least get packets sent out :)
+ */
+ pkt->hard.dest = 0;
+ return hdr_size;
+ }
+ /* otherwise, drop in the dest address */
+ pkt->hard.dest = daddr;
+ return hdr_size;
+}
+
+
+static void load_pkt(struct net_device *dev, struct arc_hardware *hard,
+ struct arc_rfc1201 *soft, int softlen, int bufnum)
+{
+ struct arcnet_local *lp = netdev_priv(dev);
+ int ofs;
+
+ /* assume length <= XMTU: someone should have handled that by now. */
+
+ if (softlen > MinTU) {
+ hard->offset[0] = 0;
+ hard->offset[1] = ofs = 512 - softlen;
+ } else if (softlen > MTU) { /* exception packet - add an extra header */
+ struct arc_rfc1201 excsoft;
+
+ excsoft.proto = soft->proto;
+ excsoft.split_flag = 0xff;
+ excsoft.sequence = htons(0xffff);
+
+ hard->offset[0] = 0;
+ ofs = 512 - softlen;
+ hard->offset[1] = ofs - RFC1201_HDR_SIZE;
+ lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE,
+ &excsoft, RFC1201_HDR_SIZE);
+ } else
+ hard->offset[0] = ofs = 256 - softlen;
+
+ lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
+ lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen);
+
+ lp->lastload_dest = hard->dest;
+}
+
+
+static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
+ int bufnum)
+{
+ struct arcnet_local *lp = netdev_priv(dev);
+ const int maxsegsize = XMTU - RFC1201_HDR_SIZE;
+ struct Outgoing *out;
+
+
+ BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
+ lp->next_tx, lp->cur_tx, bufnum);
+
+ length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
+ pkt->soft.rfc1201.split_flag = 0;
+
+ /* need to do a split packet? */
+ if (length > XMTU) {
+ out = &lp->outgoing;
+
+ out->length = length - RFC1201_HDR_SIZE;
+ out->dataleft = lp->outgoing.length;
+ out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize;
+ out->segnum = 0;
+
+ BUGMSG(D_DURING, "rfc1201 prep_tx: ready for %d-segment split "
+ "(%d bytes, seq=%d)\n", out->numsegs, out->length,
+ pkt->soft.rfc1201.sequence);
+
+ return 0; /* not done */
+ }
+ /* just load the packet into the buffers and send it off */
+ load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum);
+
+ return 1; /* done */
+}
+
+
+static int continue_tx(struct net_device *dev, int bufnum)
+{
+ struct arcnet_local *lp = netdev_priv(dev);
+ struct Outgoing *out = &lp->outgoing;
+ struct arc_hardware *hard = &out->pkt->hard;
+ struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft;
+ int maxsegsize = XMTU - RFC1201_HDR_SIZE;
+ int seglen;
+
+ BUGMSG(D_DURING,
+ "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n",
+ out->segnum, out->numsegs, soft->sequence);
+
+ /* the "new" soft header comes right before the data chunk */
+ newsoft = (struct arc_rfc1201 *)
+ (out->pkt->soft.raw + out->length - out->dataleft);
+
+ if (!out->segnum) /* first packet; newsoft == soft */
+ newsoft->split_flag = ((out->numsegs - 2) << 1) | 1;
+ else {
+ newsoft->split_flag = out->segnum << 1;
+ newsoft->proto = soft->proto;
+ newsoft->sequence = soft->sequence;
+ }
+
+ seglen = maxsegsize;
+ if (seglen > out->dataleft)
+ seglen = out->dataleft;
+ out->dataleft -= seglen;
+
+ load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum);
+
+ out->segnum++;
+ if (out->segnum >= out->numsegs)
+ return 1;
+ else
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff