/* * 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 * * ********************** */ #define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt #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 "arcdevice.h" MODULE_LICENSE("GPL"); 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) { pr_info("%s\n", "RFC1201 \"standard\" (`a') encapsulation support loaded"); 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]; arc_printk(D_DURING, dev, "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) { arc_printk(D_DURING, dev, "compensating for exception packet\n"); } else { arc_printk(D_EXTRA, dev, "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 */ arc_printk(D_RX, dev, "incoming is not split (splitflag=%d)\n", soft->split_flag); if (in->skb) { /* already assembling one! */ arc_printk(D_EXTRA, dev, "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) { 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? */ arc_printk(D_EXTRA, dev, "ARP source address was 00h, set to %02Xh\n", saddr); dev->stats.rx_crc_errors++; *cptr = saddr; } else { arc_printk(D_DURING, dev, "ARP source address (%Xh) is fine.\n", *cptr); } } else { arc_printk(D_NORMAL, dev, "funny-shaped ARP packet. (%Xh, %Xh)\n", arp->ar_hln, arp->ar_pln); dev->stats.rx_errors++; dev->stats.rx_crc_errors++; } } if (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. */ arc_printk(D_RX, dev, "packet is split (splitflag=%d, seq=%d)\n", soft->split_flag, in->sequence); if (in->skb && in->sequence != soft->sequence) { arc_printk(D_EXTRA, dev, "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 */ arc_printk(D_RX, dev, "brand new splitpacket (splitflag=%d)\n", soft->split_flag); if (in->skb) { /* already assembling one! */ arc_printk(D_EXTRA, dev, "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) { arc_printk(D_EXTRA, dev, "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) { arc_printk(D_NORMAL, dev, "(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) { arc_printk(D_EXTRA, dev, "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 not the right flag */ if (packetnum != in->lastpacket) { /* harmless duplicate? ignore. */ if (packetnum <= in->lastpacket - 1) { arc_printk(D_EXTRA, dev, "duplicate splitpacket ignored! (splitflag=%d)\n", soft->split_flag); dev->stats.rx_errors++; dev->stats.rx_frame_errors++; return; } /* "bad" duplicate, kill reassembly */ arc_printk(D_EXTRA, dev, "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; arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (unsplit)\n", skb->len, pkt->hard.source); arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (split)\n", skb->len, pkt->hard.source); 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 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 = 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: arc_printk(D_NORMAL, dev, "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; 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; 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; arc_printk(D_DURING, dev, "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; arc_printk(D_DURING, dev, "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; }