11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Linux ARCnet driver - RFC1051 ("simple" standard) packet encapsulation 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Written 1994-1999 by Avery Pennarun. 51da177e4SLinus Torvalds * Derived from skeleton.c by Donald Becker. 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com) 81da177e4SLinus Torvalds * for sponsoring the further development of this driver. 91da177e4SLinus Torvalds * 101da177e4SLinus Torvalds * ********************** 111da177e4SLinus Torvalds * 121da177e4SLinus Torvalds * The original copyright of skeleton.c was as follows: 131da177e4SLinus Torvalds * 141da177e4SLinus Torvalds * skeleton.c Written 1993 by Donald Becker. 151da177e4SLinus Torvalds * Copyright 1993 United States Government as represented by the 161da177e4SLinus Torvalds * Director, National Security Agency. This software may only be used 171da177e4SLinus Torvalds * and distributed according to the terms of the GNU General Public License as 181da177e4SLinus Torvalds * modified by SRC, incorporated herein by reference. 191da177e4SLinus Torvalds * 201da177e4SLinus Torvalds * ********************** 211da177e4SLinus Torvalds * 221da177e4SLinus Torvalds * For more details, see drivers/net/arcnet.c 231da177e4SLinus Torvalds * 241da177e4SLinus Torvalds * ********************** 251da177e4SLinus Torvalds */ 261da177e4SLinus Torvalds #include <linux/module.h> 27*5a0e3ad6STejun Heo #include <linux/gfp.h> 281da177e4SLinus Torvalds #include <linux/init.h> 291da177e4SLinus Torvalds #include <linux/if_arp.h> 301da177e4SLinus Torvalds #include <net/arp.h> 311da177e4SLinus Torvalds #include <linux/netdevice.h> 321da177e4SLinus Torvalds #include <linux/skbuff.h> 331da177e4SLinus Torvalds #include <linux/arcdevice.h> 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds #define VERSION "arcnet: RFC1051 \"simple standard\" (`s') encapsulation support loaded.\n" 361da177e4SLinus Torvalds 371da177e4SLinus Torvalds 38701181acSAl Viro static __be16 type_trans(struct sk_buff *skb, struct net_device *dev); 391da177e4SLinus Torvalds static void rx(struct net_device *dev, int bufnum, 401da177e4SLinus Torvalds struct archdr *pkthdr, int length); 411da177e4SLinus Torvalds static int build_header(struct sk_buff *skb, struct net_device *dev, 421da177e4SLinus Torvalds unsigned short type, uint8_t daddr); 431da177e4SLinus Torvalds static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, 441da177e4SLinus Torvalds int bufnum); 451da177e4SLinus Torvalds 461da177e4SLinus Torvalds 47f03aa2d8SAdrian Bunk static struct ArcProto rfc1051_proto = 481da177e4SLinus Torvalds { 491da177e4SLinus Torvalds .suffix = 's', 501da177e4SLinus Torvalds .mtu = XMTU - RFC1051_HDR_SIZE, 511da177e4SLinus Torvalds .is_ip = 1, 521da177e4SLinus Torvalds .rx = rx, 531da177e4SLinus Torvalds .build_header = build_header, 541da177e4SLinus Torvalds .prepare_tx = prepare_tx, 551da177e4SLinus Torvalds .continue_tx = NULL, 561da177e4SLinus Torvalds .ack_tx = NULL 571da177e4SLinus Torvalds }; 581da177e4SLinus Torvalds 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds static int __init arcnet_rfc1051_init(void) 611da177e4SLinus Torvalds { 621da177e4SLinus Torvalds printk(VERSION); 631da177e4SLinus Torvalds 641da177e4SLinus Torvalds arc_proto_map[ARC_P_IP_RFC1051] 651da177e4SLinus Torvalds = arc_proto_map[ARC_P_ARP_RFC1051] 661da177e4SLinus Torvalds = &rfc1051_proto; 671da177e4SLinus Torvalds 681da177e4SLinus Torvalds /* if someone else already owns the broadcast, we won't take it */ 691da177e4SLinus Torvalds if (arc_bcast_proto == arc_proto_default) 701da177e4SLinus Torvalds arc_bcast_proto = &rfc1051_proto; 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds return 0; 731da177e4SLinus Torvalds } 741da177e4SLinus Torvalds 751da177e4SLinus Torvalds static void __exit arcnet_rfc1051_exit(void) 761da177e4SLinus Torvalds { 771da177e4SLinus Torvalds arcnet_unregister_proto(&rfc1051_proto); 781da177e4SLinus Torvalds } 791da177e4SLinus Torvalds 801da177e4SLinus Torvalds module_init(arcnet_rfc1051_init); 811da177e4SLinus Torvalds module_exit(arcnet_rfc1051_exit); 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds /* 861da177e4SLinus Torvalds * Determine a packet's protocol ID. 871da177e4SLinus Torvalds * 881da177e4SLinus Torvalds * With ARCnet we have to convert everything to Ethernet-style stuff. 891da177e4SLinus Torvalds */ 90701181acSAl Viro static __be16 type_trans(struct sk_buff *skb, struct net_device *dev) 911da177e4SLinus Torvalds { 921da177e4SLinus Torvalds struct archdr *pkt = (struct archdr *) skb->data; 931da177e4SLinus Torvalds struct arc_rfc1051 *soft = &pkt->soft.rfc1051; 941da177e4SLinus Torvalds int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE; 951da177e4SLinus Torvalds 961da177e4SLinus Torvalds /* Pull off the arcnet header. */ 97459a98edSArnaldo Carvalho de Melo skb_reset_mac_header(skb); 981da177e4SLinus Torvalds skb_pull(skb, hdr_size); 991da177e4SLinus Torvalds 1001da177e4SLinus Torvalds if (pkt->hard.dest == 0) 1011da177e4SLinus Torvalds skb->pkt_type = PACKET_BROADCAST; 1021da177e4SLinus Torvalds else if (dev->flags & IFF_PROMISC) { 1031da177e4SLinus Torvalds /* if we're not sending to ourselves :) */ 1041da177e4SLinus Torvalds if (pkt->hard.dest != dev->dev_addr[0]) 1051da177e4SLinus Torvalds skb->pkt_type = PACKET_OTHERHOST; 1061da177e4SLinus Torvalds } 1071da177e4SLinus Torvalds /* now return the protocol number */ 1081da177e4SLinus Torvalds switch (soft->proto) { 1091da177e4SLinus Torvalds case ARC_P_IP_RFC1051: 1101da177e4SLinus Torvalds return htons(ETH_P_IP); 1111da177e4SLinus Torvalds case ARC_P_ARP_RFC1051: 1121da177e4SLinus Torvalds return htons(ETH_P_ARP); 1131da177e4SLinus Torvalds 1141da177e4SLinus Torvalds default: 1155803c512SStephen Hemminger dev->stats.rx_errors++; 1165803c512SStephen Hemminger dev->stats.rx_crc_errors++; 1171da177e4SLinus Torvalds return 0; 1181da177e4SLinus Torvalds } 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds return htons(ETH_P_IP); 1211da177e4SLinus Torvalds } 1221da177e4SLinus Torvalds 1231da177e4SLinus Torvalds 1241da177e4SLinus Torvalds /* packet receiver */ 1251da177e4SLinus Torvalds static void rx(struct net_device *dev, int bufnum, 1261da177e4SLinus Torvalds struct archdr *pkthdr, int length) 1271da177e4SLinus Torvalds { 128454d7c9bSWang Chen struct arcnet_local *lp = netdev_priv(dev); 1291da177e4SLinus Torvalds struct sk_buff *skb; 1301da177e4SLinus Torvalds struct archdr *pkt = pkthdr; 1311da177e4SLinus Torvalds int ofs; 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length); 1341da177e4SLinus Torvalds 1351da177e4SLinus Torvalds if (length >= MinTU) 1361da177e4SLinus Torvalds ofs = 512 - length; 1371da177e4SLinus Torvalds else 1381da177e4SLinus Torvalds ofs = 256 - length; 1391da177e4SLinus Torvalds 1401da177e4SLinus Torvalds skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC); 1411da177e4SLinus Torvalds if (skb == NULL) { 1421da177e4SLinus Torvalds BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n"); 1435803c512SStephen Hemminger dev->stats.rx_dropped++; 1441da177e4SLinus Torvalds return; 1451da177e4SLinus Torvalds } 1461da177e4SLinus Torvalds skb_put(skb, length + ARC_HDR_SIZE); 1471da177e4SLinus Torvalds skb->dev = dev; 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds pkt = (struct archdr *) skb->data; 1501da177e4SLinus Torvalds 1511da177e4SLinus Torvalds /* up to sizeof(pkt->soft) has already been copied from the card */ 1521da177e4SLinus Torvalds memcpy(pkt, pkthdr, sizeof(struct archdr)); 1531da177e4SLinus Torvalds if (length > sizeof(pkt->soft)) 1541da177e4SLinus Torvalds lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft), 1551da177e4SLinus Torvalds pkt->soft.raw + sizeof(pkt->soft), 1561da177e4SLinus Torvalds length - sizeof(pkt->soft)); 1571da177e4SLinus Torvalds 1581da177e4SLinus Torvalds BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx"); 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds skb->protocol = type_trans(skb, dev); 1611da177e4SLinus Torvalds netif_rx(skb); 1621da177e4SLinus Torvalds } 1631da177e4SLinus Torvalds 1641da177e4SLinus Torvalds 1651da177e4SLinus Torvalds /* 1661da177e4SLinus Torvalds * Create the ARCnet hard/soft headers for RFC1051. 1671da177e4SLinus Torvalds */ 1681da177e4SLinus Torvalds static int build_header(struct sk_buff *skb, struct net_device *dev, 1691da177e4SLinus Torvalds unsigned short type, uint8_t daddr) 1701da177e4SLinus Torvalds { 1711da177e4SLinus Torvalds int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE; 1721da177e4SLinus Torvalds struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size); 1731da177e4SLinus Torvalds struct arc_rfc1051 *soft = &pkt->soft.rfc1051; 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds /* set the protocol ID according to RFC1051 */ 1761da177e4SLinus Torvalds switch (type) { 1771da177e4SLinus Torvalds case ETH_P_IP: 1781da177e4SLinus Torvalds soft->proto = ARC_P_IP_RFC1051; 1791da177e4SLinus Torvalds break; 1801da177e4SLinus Torvalds case ETH_P_ARP: 1811da177e4SLinus Torvalds soft->proto = ARC_P_ARP_RFC1051; 1821da177e4SLinus Torvalds break; 1831da177e4SLinus Torvalds default: 1841da177e4SLinus Torvalds BUGMSG(D_NORMAL, "RFC1051: I don't understand protocol %d (%Xh)\n", 1851da177e4SLinus Torvalds type, type); 1865803c512SStephen Hemminger dev->stats.tx_errors++; 1875803c512SStephen Hemminger dev->stats.tx_aborted_errors++; 1881da177e4SLinus Torvalds return 0; 1891da177e4SLinus Torvalds } 1901da177e4SLinus Torvalds 1911da177e4SLinus Torvalds 1921da177e4SLinus Torvalds /* 1931da177e4SLinus Torvalds * Set the source hardware address. 1941da177e4SLinus Torvalds * 1951da177e4SLinus Torvalds * This is pretty pointless for most purposes, but it can help in 1961da177e4SLinus Torvalds * debugging. ARCnet does not allow us to change the source address in 1971da177e4SLinus Torvalds * the actual packet sent) 1981da177e4SLinus Torvalds */ 1991da177e4SLinus Torvalds pkt->hard.source = *dev->dev_addr; 2001da177e4SLinus Torvalds 2011da177e4SLinus Torvalds /* see linux/net/ethernet/eth.c to see where I got the following */ 2021da177e4SLinus Torvalds 2031da177e4SLinus Torvalds if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { 2041da177e4SLinus Torvalds /* 2051da177e4SLinus Torvalds * FIXME: fill in the last byte of the dest ipaddr here to better 2061da177e4SLinus Torvalds * comply with RFC1051 in "noarp" mode. 2071da177e4SLinus Torvalds */ 2081da177e4SLinus Torvalds pkt->hard.dest = 0; 2091da177e4SLinus Torvalds return hdr_size; 2101da177e4SLinus Torvalds } 2111da177e4SLinus Torvalds /* otherwise, just fill it in and go! */ 2121da177e4SLinus Torvalds pkt->hard.dest = daddr; 2131da177e4SLinus Torvalds 2141da177e4SLinus Torvalds return hdr_size; /* success */ 2151da177e4SLinus Torvalds } 2161da177e4SLinus Torvalds 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, 2191da177e4SLinus Torvalds int bufnum) 2201da177e4SLinus Torvalds { 221454d7c9bSWang Chen struct arcnet_local *lp = netdev_priv(dev); 2221da177e4SLinus Torvalds struct arc_hardware *hard = &pkt->hard; 2231da177e4SLinus Torvalds int ofs; 2241da177e4SLinus Torvalds 2251da177e4SLinus Torvalds BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n", 2261da177e4SLinus Torvalds lp->next_tx, lp->cur_tx, bufnum); 2271da177e4SLinus Torvalds 2281da177e4SLinus Torvalds length -= ARC_HDR_SIZE; /* hard header is not included in packet length */ 2291da177e4SLinus Torvalds 2301da177e4SLinus Torvalds if (length > XMTU) { 2311da177e4SLinus Torvalds /* should never happen! other people already check for this. */ 2321da177e4SLinus Torvalds BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n", 2331da177e4SLinus Torvalds length, XMTU); 2341da177e4SLinus Torvalds length = XMTU; 2351da177e4SLinus Torvalds } 2361da177e4SLinus Torvalds if (length > MinTU) { 2371da177e4SLinus Torvalds hard->offset[0] = 0; 2381da177e4SLinus Torvalds hard->offset[1] = ofs = 512 - length; 2391da177e4SLinus Torvalds } else if (length > MTU) { 2401da177e4SLinus Torvalds hard->offset[0] = 0; 2411da177e4SLinus Torvalds hard->offset[1] = ofs = 512 - length - 3; 2421da177e4SLinus Torvalds } else 2431da177e4SLinus Torvalds hard->offset[0] = ofs = 256 - length; 2441da177e4SLinus Torvalds 2451da177e4SLinus Torvalds lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); 2461da177e4SLinus Torvalds lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length); 2471da177e4SLinus Torvalds 2481da177e4SLinus Torvalds lp->lastload_dest = hard->dest; 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvalds return 1; /* done */ 2511da177e4SLinus Torvalds } 252