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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/net/arcnet/rfc1201.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/net/arcnet/rfc1201.c')
-rw-r--r-- | drivers/net/arcnet/rfc1201.c | 547 |
1 files changed, 547 insertions, 0 deletions
diff --git a/drivers/net/arcnet/rfc1201.c b/drivers/net/arcnet/rfc1201.c new file mode 100644 index 000000000..a4c856282 --- /dev/null +++ b/drivers/net/arcnet/rfc1201.c @@ -0,0 +1,547 @@ +/* + * 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; +} |