/* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * Ethernet-type device handling. * * Version: @(#)eth.c 1.0.7 05/25/93 * * Authors: Ross Biro * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> * Mark Evans, <evansmp@uhura.aston.ac.uk> * Florian La Roche, <rzsfl@rz.uni-sb.de> * Alan Cox, <gw4pts@gw4pts.ampr.org> * * Fixes: * Mr Linux : Arp problems * Alan Cox : Generic queue tidyup (very tiny here) * Alan Cox : eth_header ntohs should be htons * Alan Cox : eth_rebuild_header missing an htons and * minor other things. * Tegge : Arp bug fixes. * Florian : Removed many unnecessary functions, code cleanup * and changes for new arp and skbuff. * Alan Cox : Redid header building to reflect new format. * Alan Cox : ARP only when compiled with CONFIG_INET * Greg Page : 802.2 and SNAP stuff. * Alan Cox : MAC layer pointers/new format. * Paul Gortmaker : eth_copy_and_sum shouldn't csum padding. * Alan Cox : Protect against forwarding explosions with * older network drivers and IFF_ALLMULTI. * Christer Weinigel : Better rebuild header message. * Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup(). * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/inet.h> #include <linux/ip.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/skbuff.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/if_ether.h> #include <net/dst.h> #include <net/arp.h> #include <net/sock.h> #include <net/ipv6.h> #include <net/ip.h> #include <net/dsa.h> #include <linux/uaccess.h> __setup("ether=", netdev_boot_setup); /** * eth_header - create the Ethernet header * @skb: buffer to alter * @dev: source device * @type: Ethernet type field * @daddr: destination address (NULL leave destination address) * @saddr: source address (NULL use device source address) * @len: packet length (<= skb->len) * * * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length * in here instead. */ int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, const void *daddr, const void *saddr, unsigned int len) { struct ethhdr *eth = (struct ethhdr *)skb_push(skb, ETH_HLEN); if (type != ETH_P_802_3 && type != ETH_P_802_2) eth->h_proto = htons(type); else eth->h_proto = htons(len); /* * Set the source hardware address. */ if (!saddr) saddr = dev->dev_addr; memcpy(eth->h_source, saddr, ETH_ALEN); if (daddr) { memcpy(eth->h_dest, daddr, ETH_ALEN); return ETH_HLEN; } /* * Anyway, the loopback-device should never use this function... */ if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { memset(eth->h_dest, 0, ETH_ALEN); return ETH_HLEN; } return -ETH_HLEN; } EXPORT_SYMBOL(eth_header); /** * eth_rebuild_header- rebuild the Ethernet MAC header. * @skb: socket buffer to update * * This is called after an ARP or IPV6 ndisc it's resolution on this * sk_buff. We now let protocol (ARP) fill in the other fields. * * This routine CANNOT use cached dst->neigh! * Really, it is used only when dst->neigh is wrong. */ int eth_rebuild_header(struct sk_buff *skb) { struct ethhdr *eth = (struct ethhdr *)skb->data; struct net_device *dev = skb->dev; switch (eth->h_proto) { #ifdef CONFIG_INET case htons(ETH_P_IP): return arp_find(eth->h_dest, skb); #endif default: netdev_dbg(dev, "%s: unable to resolve type %X addresses.\n", dev->name, ntohs(eth->h_proto)); memcpy(eth->h_source, dev->dev_addr, ETH_ALEN); break; } return 0; } EXPORT_SYMBOL(eth_rebuild_header); /** * eth_type_trans - determine the packet's protocol ID. * @skb: received socket data * @dev: receiving network device * * The rule here is that we * assume 802.3 if the type field is short enough to be a length. * This is normal practice and works for any 'now in use' protocol. */ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) { unsigned short _service_access_point; const unsigned short *sap; const struct ethhdr *eth; skb->dev = dev; skb_reset_mac_header(skb); skb_pull_inline(skb, ETH_HLEN); eth = eth_hdr(skb); if (unlikely(is_multicast_ether_addr(eth->h_dest))) { if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast)) skb->pkt_type = PACKET_BROADCAST; else skb->pkt_type = PACKET_MULTICAST; } else if (unlikely(!ether_addr_equal_64bits(eth->h_dest, dev->dev_addr))) skb->pkt_type = PACKET_OTHERHOST; /* * Some variants of DSA tagging don't have an ethertype field * at all, so we check here whether one of those tagging * variants has been configured on the receiving interface, * and if so, set skb->protocol without looking at the packet. */ if (unlikely(netdev_uses_dsa_tags(dev))) return htons(ETH_P_DSA); if (unlikely(netdev_uses_trailer_tags(dev))) return htons(ETH_P_TRAILER); if (likely(ntohs(eth->h_proto) >= ETH_P_802_3_MIN)) return eth->h_proto; /* * This is a magic hack to spot IPX packets. Older Novell breaks * the protocol design and runs IPX over 802.3 without an 802.2 LLC * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This * won't work for fault tolerant netware but does for the rest. */ sap = skb_header_pointer(skb, 0, sizeof(*sap), &_service_access_point); if (sap && *sap == 0xFFFF) return htons(ETH_P_802_3); /* * Real 802.2 LLC */ return htons(ETH_P_802_2); } EXPORT_SYMBOL(eth_type_trans); /** * eth_header_parse - extract hardware address from packet * @skb: packet to extract header from * @haddr: destination buffer */ int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr) { const struct ethhdr *eth = eth_hdr(skb); memcpy(haddr, eth->h_source, ETH_ALEN); return ETH_ALEN; } EXPORT_SYMBOL(eth_header_parse); /** * eth_header_cache - fill cache entry from neighbour * @neigh: source neighbour * @hh: destination cache entry * @type: Ethernet type field * * Create an Ethernet header template from the neighbour. */ int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type) { struct ethhdr *eth; const struct net_device *dev = neigh->dev; eth = (struct ethhdr *) (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth)))); if (type == htons(ETH_P_802_3)) return -1; eth->h_proto = type; memcpy(eth->h_source, dev->dev_addr, ETH_ALEN); memcpy(eth->h_dest, neigh->ha, ETH_ALEN); hh->hh_len = ETH_HLEN; return 0; } EXPORT_SYMBOL(eth_header_cache); /** * eth_header_cache_update - update cache entry * @hh: destination cache entry * @dev: network device * @haddr: new hardware address * * Called by Address Resolution module to notify changes in address. */ void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev, const unsigned char *haddr) { memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)), haddr, ETH_ALEN); } EXPORT_SYMBOL(eth_header_cache_update); /** * eth_prepare_mac_addr_change - prepare for mac change * @dev: network device * @p: socket address */ int eth_prepare_mac_addr_change(struct net_device *dev, void *p) { struct sockaddr *addr = p; if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev)) return -EBUSY; if (!is_valid_ether_addr(addr->sa_data)) return -EADDRNOTAVAIL; return 0; } EXPORT_SYMBOL(eth_prepare_mac_addr_change); /** * eth_commit_mac_addr_change - commit mac change * @dev: network device * @p: socket address */ void eth_commit_mac_addr_change(struct net_device *dev, void *p) { struct sockaddr *addr = p; memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); } EXPORT_SYMBOL(eth_commit_mac_addr_change); /** * eth_mac_addr - set new Ethernet hardware address * @dev: network device * @p: socket address * * Change hardware address of device. * * This doesn't change hardware matching, so needs to be overridden * for most real devices. */ int eth_mac_addr(struct net_device *dev, void *p) { int ret; ret = eth_prepare_mac_addr_change(dev, p); if (ret < 0) return ret; eth_commit_mac_addr_change(dev, p); return 0; } EXPORT_SYMBOL(eth_mac_addr); /** * eth_change_mtu - set new MTU size * @dev: network device * @new_mtu: new Maximum Transfer Unit * * Allow changing MTU size. Needs to be overridden for devices * supporting jumbo frames. */ int eth_change_mtu(struct net_device *dev, int new_mtu) { if (new_mtu < 68 || new_mtu > ETH_DATA_LEN) return -EINVAL; dev->mtu = new_mtu; return 0; } EXPORT_SYMBOL(eth_change_mtu); int eth_validate_addr(struct net_device *dev) { if (!is_valid_ether_addr(dev->dev_addr)) return -EADDRNOTAVAIL; return 0; } EXPORT_SYMBOL(eth_validate_addr); const struct header_ops eth_header_ops ____cacheline_aligned = { .create = eth_header, .parse = eth_header_parse, .rebuild = eth_rebuild_header, .cache = eth_header_cache, .cache_update = eth_header_cache_update, }; /** * ether_setup - setup Ethernet network device * @dev: network device * * Fill in the fields of the device structure with Ethernet-generic values. */ void ether_setup(struct net_device *dev) { dev->header_ops = ð_header_ops; dev->type = ARPHRD_ETHER; dev->hard_header_len = ETH_HLEN; dev->mtu = ETH_DATA_LEN; dev->addr_len = ETH_ALEN; dev->tx_queue_len = 1000; /* Ethernet wants good queues */ dev->flags = IFF_BROADCAST|IFF_MULTICAST; dev->priv_flags |= IFF_TX_SKB_SHARING; memset(dev->broadcast, 0xFF, ETH_ALEN); } EXPORT_SYMBOL(ether_setup); /** * alloc_etherdev_mqs - Allocates and sets up an Ethernet device * @sizeof_priv: Size of additional driver-private structure to be allocated * for this Ethernet device * @txqs: The number of TX queues this device has. * @rxqs: The number of RX queues this device has. * * Fill in the fields of the device structure with Ethernet-generic * values. Basically does everything except registering the device. * * Constructs a new net device, complete with a private data area of * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for * this private data area. */ struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs, unsigned int rxqs) { return alloc_netdev_mqs(sizeof_priv, "eth%d", ether_setup, txqs, rxqs); } EXPORT_SYMBOL(alloc_etherdev_mqs); ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len) { return scnprintf(buf, PAGE_SIZE, "%*phC\n", len, addr); } EXPORT_SYMBOL(sysfs_format_mac);