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// SPDX-License-Identifier: GPL-2.0-or-later/* * 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(). */#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/nvmem-consumer.h>#include <linux/etherdevice.h>#include <linux/skbuff.h>#include <linux/errno.h>#include <linux/init.h>#include <linux/if_ether.h>#include <linux/of_net.h>#include <linux/pci.h>#include <linux/property.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 <net/flow_dissector.h>#include <net/gro.h>#include <linux/uaccess.h>#include <net/pkt_sched.h> /** * 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 = 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)) {		eth_zero_addr(eth->h_dest);		return ETH_HLEN;	} 	return -ETH_HLEN;}EXPORT_SYMBOL(eth_header); /** * eth_get_headlen - determine the length of header for an ethernet frame * @dev: pointer to network device * @data: pointer to start of frame * @len: total length of frame * * Make a best effort attempt to pull the length for all of the headers for * a given frame in a linear buffer. */u32 eth_get_headlen(const struct net_device *dev, const void *data, u32 len){	const unsigned int flags = FLOW_DISSECTOR_F_PARSE_1ST_FRAG;	const struct ethhdr *eth = (const struct ethhdr *)data;	struct flow_keys_basic keys; 	/* this should never happen, but better safe than sorry */	if (unlikely(len < sizeof(*eth)))		return len; 	/* parse any remaining L2/L3 headers, check for L4 */	if (!skb_flow_dissect_flow_keys_basic(dev_net(dev), NULL, &keys, data,					      eth->h_proto, sizeof(*eth),					      len, flags))		return max_t(u32, keys.control.thoff, sizeof(*eth)); 	/* parse for any L4 headers */	return min_t(u32, __skb_get_poff(NULL, data, &keys, len), len);}EXPORT_SYMBOL(eth_get_headlen); /** * 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){	const unsigned short *sap;	const struct ethhdr *eth;	__be16 res; 	skb->dev = dev;	skb_reset_mac_header(skb); 	eth = eth_skb_pull_mac(skb);	eth_skb_pkt_type(skb, dev); 	/*	 * 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(dev)))		return htons(ETH_P_XDSA); 	if (likely(eth_proto_is_802_3(eth->h_proto)))		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.	 *	We use skb->dev as temporary storage to not hit	 *	CONFIG_STACKPROTECTOR_STRONG=y costs on some platforms.	 */	sap = skb_header_pointer(skb, 0, sizeof(*sap), &skb->dev);	res = (sap && *sap == 0xFFFF) ? htons(ETH_P_802_3) : htons(ETH_P_802_2); 	/* restore skb->dev in case it was mangled by skb_header_pointer(). */	skb->dev = dev;	return res;}EXPORT_SYMBOL(eth_type_trans); int eth_header_parse(const struct sk_buff *skb, const struct net_device *dev,		     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); 	/* Pairs with READ_ONCE() in neigh_resolve_output(),	 * neigh_hh_output() and neigh_update_hhs().	 */	smp_store_release(&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_header_parse_protocol - extract protocol from L2 header * @skb: packet to extract protocol from */__be16 eth_header_parse_protocol(const struct sk_buff *skb){	const struct ethhdr *eth = eth_hdr(skb); 	return eth->h_proto;}EXPORT_SYMBOL(eth_header_parse_protocol); /** * 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; 	eth_hw_addr_set(dev, addr->sa_data);}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); 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,	.cache		= eth_header_cache,	.cache_update	= eth_header_cache_update,	.parse_protocol	= eth_header_parse_protocol,}; /** * 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		= &eth_header_ops;	dev->type		= ARPHRD_ETHER;	dev->hard_header_len 	= ETH_HLEN;	dev->min_header_len	= ETH_HLEN;	dev->mtu		= ETH_DATA_LEN;	dev->min_mtu		= ETH_MIN_MTU;	dev->max_mtu		= ETH_DATA_LEN;	dev->addr_len		= ETH_ALEN;	dev->tx_queue_len	= DEFAULT_TX_QUEUE_LEN;	dev->flags		= IFF_BROADCAST|IFF_MULTICAST;	dev->priv_flags		|= IFF_TX_SKB_SHARING; 	eth_broadcast_addr(dev->broadcast); }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", NET_NAME_ENUM,				ether_setup, txqs, rxqs);}EXPORT_SYMBOL(alloc_etherdev_mqs); ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len){	return sysfs_emit(buf, "%*phC\n", len, addr);}EXPORT_SYMBOL(sysfs_format_mac); struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb){	const struct packet_offload *ptype;	unsigned int hlen, off_eth;	struct sk_buff *pp = NULL;	struct ethhdr *eh, *eh2;	struct sk_buff *p;	__be16 type;	int flush = 1; 	off_eth = skb_gro_offset(skb);	hlen = off_eth + sizeof(*eh);	eh = skb_gro_header(skb, hlen, off_eth);	if (unlikely(!eh))		goto out; 	flush = 0; 	list_for_each_entry(p, head, list) {		if (!NAPI_GRO_CB(p)->same_flow)			continue; 		eh2 = (struct ethhdr *)(p->data + off_eth);		if (compare_ether_header(eh, eh2)) {			NAPI_GRO_CB(p)->same_flow = 0;			continue;		}	} 	type = eh->h_proto; 	ptype = gro_find_receive_by_type(type);	if (ptype == NULL) {		flush = 1;		goto out;	} 	skb_gro_pull(skb, sizeof(*eh));	skb_gro_postpull_rcsum(skb, eh, sizeof(*eh)); 	pp = indirect_call_gro_receive_inet(ptype->callbacks.gro_receive,					    ipv6_gro_receive, inet_gro_receive,					    head, skb); out:	skb_gro_flush_final(skb, pp, flush); 	return pp;}EXPORT_SYMBOL(eth_gro_receive); int eth_gro_complete(struct sk_buff *skb, int nhoff){	struct ethhdr *eh = (struct ethhdr *)(skb->data + nhoff);	__be16 type = eh->h_proto;	struct packet_offload *ptype;	int err = -ENOSYS; 	if (skb->encapsulation)		skb_set_inner_mac_header(skb, nhoff); 	ptype = gro_find_complete_by_type(type);	if (ptype != NULL)		err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,					 ipv6_gro_complete, inet_gro_complete,					 skb, nhoff + sizeof(*eh)); 	return err;}EXPORT_SYMBOL(eth_gro_complete); static struct packet_offload eth_packet_offload __read_mostly = {	.type = cpu_to_be16(ETH_P_TEB),	.priority = 10,	.callbacks = {		.gro_receive = eth_gro_receive,		.gro_complete = eth_gro_complete,	},}; static int __init eth_offload_init(void){	dev_add_offload(&eth_packet_offload); 	return 0;} fs_initcall(eth_offload_init); unsigned char * __weak arch_get_platform_mac_address(void){	return NULL;} int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr){	unsigned char *addr;	int ret; 	ret = of_get_mac_address(dev->of_node, mac_addr);	if (!ret)		return 0; 	addr = arch_get_platform_mac_address();	if (!addr)		return -ENODEV; 	ether_addr_copy(mac_addr, addr); 	return 0;}

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