/* * Linux ARCnet driver - "cap mode" packet encapsulation. * It adds sequence numbers to packets for communicating between a user space * application and the driver. After a transmit it sends a packet with protocol * byte 0 back up to the userspace containing the sequence number of the packet * plus the transmit-status on the ArcNet. * * Written 2002-4 by Esben Nielsen, Vestas Wind Systems A/S * Derived from arc-rawmode.c by Avery Pennarun. * arc-rawmode was in turned based on skeleton.c, see below. * * ********************** * * 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/module.h> #include <linux/init.h> #include <linux/if_arp.h> #include <net/arp.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <linux/arcdevice.h> #define VERSION "arcnet: cap mode (`c') encapsulation support loaded.\n" 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 ack_tx(struct net_device *dev, int acked); static struct ArcProto capmode_proto = { 'r', XMTU, 0, rx, build_header, prepare_tx, NULL, ack_tx }; void arcnet_cap_init(void) { int count; for (count = 1; count <= 8; count++) if (arc_proto_map[count] == arc_proto_default) arc_proto_map[count] = &capmode_proto; /* for cap mode, we only set the bcast proto if there's no better one */ if (arc_bcast_proto == arc_proto_default) arc_bcast_proto = &capmode_proto; arc_proto_default = &capmode_proto; arc_raw_proto = &capmode_proto; } #ifdef MODULE int __init init_module(void) { printk(VERSION); arcnet_cap_init(); return 0; } void cleanup_module(void) { arcnet_unregister_proto(&capmode_proto); } MODULE_LICENSE("GPL"); #endif /* MODULE */ /* packet receiver */ static void rx(struct net_device *dev, int bufnum, struct archdr *pkthdr, int length) { struct arcnet_local *lp = (struct arcnet_local *) dev->priv; struct sk_buff *skb; struct archdr *pkt = pkthdr; char *pktbuf, *pkthdrbuf; int ofs; BUGMSG(D_DURING, "it's a raw(cap) packet (length=%d)\n", length); if (length >= MinTU) ofs = 512 - length; else ofs = 256 - length; skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC); if (skb == NULL) { BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n"); lp->stats.rx_dropped++; return; } skb_put(skb, length + ARC_HDR_SIZE + sizeof(int)); skb->dev = dev; skb_reset_mac_header(skb); pkt = (struct archdr *)skb_mac_header(skb); skb_pull(skb, ARC_HDR_SIZE); /* up to sizeof(pkt->soft) has already been copied from the card */ /* squeeze in an int for the cap encapsulation */ /* use these variables to be sure we count in bytes, not in sizeof(struct archdr) */ pktbuf=(char*)pkt; pkthdrbuf=(char*)pkthdr; memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto)); memcpy(pktbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto)+sizeof(int), pkthdrbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto), sizeof(struct archdr)-ARC_HDR_SIZE-sizeof(pkt->soft.cap.proto)); if (length > sizeof(pkt->soft)) lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft), pkt->soft.raw + sizeof(pkt->soft) + sizeof(int), length - sizeof(pkt->soft)); BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx"); skb->protocol = __constant_htons(ETH_P_ARCNET); ; netif_rx(skb); dev->last_rx = jiffies; } /* * Create the ARCnet hard/soft headers for cap mode. * There aren't any soft headers in cap mode - not even the protocol id. */ static int build_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, uint8_t daddr) { int hdr_size = ARC_HDR_SIZE; struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size); BUGMSG(D_PROTO, "Preparing header for cap packet %x.\n", *((int*)&pkt->soft.cap.cookie[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; /* 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. */ pkt->hard.dest = 0; return hdr_size; } /* otherwise, just fill it in and go! */ pkt->hard.dest = daddr; return hdr_size; /* success */ } static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, int bufnum) { struct arcnet_local *lp = (struct arcnet_local *) dev->priv; struct arc_hardware *hard = &pkt->hard; int ofs; /* hard header is not included in packet length */ length -= ARC_HDR_SIZE; /* And neither is the cookie field */ length -= sizeof(int); BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n", lp->next_tx, lp->cur_tx, bufnum); BUGMSG(D_PROTO, "Sending for cap packet %x.\n", *((int*)&pkt->soft.cap.cookie[0])); if (length > XMTU) { /* should never happen! other people already check for this. */ BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n", length, XMTU); length = XMTU; } if (length > MinTU) { hard->offset[0] = 0; hard->offset[1] = ofs = 512 - length; } else if (length > MTU) { hard->offset[0] = 0; hard->offset[1] = ofs = 512 - length - 3; } else hard->offset[0] = ofs = 256 - length; BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n", length,ofs); // Copy the arcnet-header + the protocol byte down: lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto, sizeof(pkt->soft.cap.proto)); // Skip the extra integer we have written into it as a cookie // but write the rest of the message: lp->hw.copy_to_card(dev, bufnum, ofs+1, ((unsigned char*)&pkt->soft.cap.mes),length-1); lp->lastload_dest = hard->dest; return 1; /* done */ } static int ack_tx(struct net_device *dev, int acked) { struct arcnet_local *lp = (struct arcnet_local *) dev->priv; struct sk_buff *ackskb; struct archdr *ackpkt; int length=sizeof(struct arc_cap); BUGMSG(D_DURING, "capmode: ack_tx: protocol: %x: result: %d\n", lp->outgoing.skb->protocol, acked); BUGLVL(D_SKB) arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx"); /* Now alloc a skb to send back up through the layers: */ ackskb = alloc_skb(length + ARC_HDR_SIZE , GFP_ATOMIC); if (ackskb == NULL) { BUGMSG(D_NORMAL, "Memory squeeze, can't acknowledge.\n"); goto free_outskb; } skb_put(ackskb, length + ARC_HDR_SIZE ); ackskb->dev = dev; skb_reset_mac_header(ackskb); ackpkt = (struct archdr *)skb_mac_header(ackskb); /* skb_pull(ackskb, ARC_HDR_SIZE); */ skb_copy_from_linear_data(lp->outgoing.skb, ackpkt, ARC_HDR_SIZE + sizeof(struct arc_cap)); ackpkt->soft.cap.proto=0; /* using protocol 0 for acknowledge */ ackpkt->soft.cap.mes.ack=acked; BUGMSG(D_PROTO, "Ackknowledge for cap packet %x.\n", *((int*)&ackpkt->soft.cap.cookie[0])); ackskb->protocol = __constant_htons(ETH_P_ARCNET); BUGLVL(D_SKB) arcnet_dump_skb(dev, ackskb, "ack_tx_recv"); netif_rx(ackskb); free_outskb: dev_kfree_skb_irq(lp->outgoing.skb); lp->outgoing.proto = NULL; /* We are always finished when in this protocol */ return 0; }