// 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, <[email protected]>
* Mark Evans, <[email protected]>
* Florian La Roche, <[email protected]>
* Alan Cox, <[email protected]>
*
* 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)
{
unsigned short _service_access_point;
const unsigned short *sap;
const struct ethhdr *eth;
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.
*/
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);
/* 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 = ð_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(ð_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;
}
EXPORT_SYMBOL(eth_platform_get_mac_address);
/**
* platform_get_ethdev_address - Set netdev's MAC address from a given device
* @dev: Pointer to the device
* @netdev: Pointer to netdev to write the address to
*
* Wrapper around eth_platform_get_mac_address() which writes the address
* directly to netdev->dev_addr.
*/
int platform_get_ethdev_address(struct device *dev, struct net_device *netdev)
{
u8 addr[ETH_ALEN] __aligned(2);
int ret;
ret = eth_platform_get_mac_address(dev, addr);
if (!ret)
eth_hw_addr_set(netdev, addr);
return ret;
}
EXPORT_SYMBOL(platform_get_ethdev_address);
/**
* nvmem_get_mac_address - Obtain the MAC address from an nvmem cell named
* 'mac-address' associated with given device.
*
* @dev: Device with which the mac-address cell is associated.
* @addrbuf: Buffer to which the MAC address will be copied on success.
*
* Returns 0 on success or a negative error number on failure.
*/
int nvmem_get_mac_address(struct device *dev, void *addrbuf)
{
struct nvmem_cell *cell;
const void *mac;
size_t len;
cell = nvmem_cell_get(dev, "mac-address");
if (IS_ERR(cell))
return PTR_ERR(cell);
mac = nvmem_cell_read(cell, &len);
nvmem_cell_put(cell);
if (IS_ERR(mac))
return PTR_ERR(mac);
if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
kfree(mac);
return -EINVAL;
}
ether_addr_copy(addrbuf, mac);
kfree(mac);
return 0;
}
static int fwnode_get_mac_addr(struct fwnode_handle *fwnode,
const char *name, char *addr)
{
int ret;
ret = fwnode_property_read_u8_array(fwnode, name, addr, ETH_ALEN);
if (ret)
return ret;
if (!is_valid_ether_addr(addr))
return -EINVAL;
return 0;
}
/**
* fwnode_get_mac_address - Get the MAC from the firmware node
* @fwnode: Pointer to the firmware node
* @addr: Address of buffer to store the MAC in
*
* Search the firmware node for the best MAC address to use. 'mac-address' is
* checked first, because that is supposed to contain to "most recent" MAC
* address. If that isn't set, then 'local-mac-address' is checked next,
* because that is the default address. If that isn't set, then the obsolete
* 'address' is checked, just in case we're using an old device tree.
*
* Note that the 'address' property is supposed to contain a virtual address of
* the register set, but some DTS files have redefined that property to be the
* MAC address.
*
* All-zero MAC addresses are rejected, because those could be properties that
* exist in the firmware tables, but were not updated by the firmware. For
* example, the DTS could define 'mac-address' and 'local-mac-address', with
* zero MAC addresses. Some older U-Boots only initialized 'local-mac-address'.
* In this case, the real MAC is in 'local-mac-address', and 'mac-address'
* exists but is all zeros.
*/
int fwnode_get_mac_address(struct fwnode_handle *fwnode, char *addr)
{
if (!fwnode_get_mac_addr(fwnode, "mac-address", addr) ||
!fwnode_get_mac_addr(fwnode, "local-mac-address", addr) ||
!fwnode_get_mac_addr(fwnode, "address", addr))
return 0;
return -ENOENT;
}
EXPORT_SYMBOL(fwnode_get_mac_address);
/**
* device_get_mac_address - Get the MAC for a given device
* @dev: Pointer to the device
* @addr: Address of buffer to store the MAC in
*/
int device_get_mac_address(struct device *dev, char *addr)
{
return fwnode_get_mac_address(dev_fwnode(dev), addr);
}
EXPORT_SYMBOL(device_get_mac_address);
/**
* device_get_ethdev_address - Set netdev's MAC address from a given device
* @dev: Pointer to the device
* @netdev: Pointer to netdev to write the address to
*
* Wrapper around device_get_mac_address() which writes the address
* directly to netdev->dev_addr.
*/
int device_get_ethdev_address(struct device *dev, struct net_device *netdev)
{
u8 addr[ETH_ALEN];
int ret;
ret = device_get_mac_address(dev, addr);
if (!ret)
eth_hw_addr_set(netdev, addr);
return ret;
}
EXPORT_SYMBOL(device_get_ethdev_address);
Codebase Browser
linux