2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Ethernet-type device handling.
8 * Version: @(#)eth.c 1.0.7 05/25/93
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Mark Evans, <evansmp@uhura.aston.ac.uk>
13 * Florian La Roche, <rzsfl@rz.uni-sb.de>
14 * Alan Cox, <gw4pts@gw4pts.ampr.org>
17 * Mr Linux : Arp problems
18 * Alan Cox : Generic queue tidyup (very tiny here)
19 * Alan Cox : eth_header ntohs should be htons
20 * Alan Cox : eth_rebuild_header missing an htons and
22 * Tegge : Arp bug fixes.
23 * Florian : Removed many unnecessary functions, code cleanup
24 * and changes for new arp and skbuff.
25 * Alan Cox : Redid header building to reflect new format.
26 * Alan Cox : ARP only when compiled with CONFIG_INET
27 * Greg Page : 802.2 and SNAP stuff.
28 * Alan Cox : MAC layer pointers/new format.
29 * Paul Gortmaker : eth_copy_and_sum shouldn't csum padding.
30 * Alan Cox : Protect against forwarding explosions with
31 * older network drivers and IFF_ALLMULTI.
32 * Christer Weinigel : Better rebuild header message.
33 * Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup().
35 * This program is free software; you can redistribute it and/or
36 * modify it under the terms of the GNU General Public License
37 * as published by the Free Software Foundation; either version
38 * 2 of the License, or (at your option) any later version.
40 #include <linux/module.h>
41 #include <linux/types.h>
42 #include <linux/kernel.h>
43 #include <linux/string.h>
45 #include <linux/socket.h>
47 #include <linux/inet.h>
49 #include <linux/netdevice.h>
50 #include <linux/etherdevice.h>
51 #include <linux/skbuff.h>
52 #include <linux/errno.h>
53 #include <linux/init.h>
54 #include <linux/if_ether.h>
61 #include <linux/uaccess.h>
63 __setup("ether=", netdev_boot_setup
);
66 * eth_header - create the Ethernet header
67 * @skb: buffer to alter
69 * @type: Ethernet type field
70 * @daddr: destination address (NULL leave destination address)
71 * @saddr: source address (NULL use device source address)
72 * @len: packet length (<= skb->len)
75 * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
78 int eth_header(struct sk_buff
*skb
, struct net_device
*dev
,
80 const void *daddr
, const void *saddr
, unsigned int len
)
82 struct ethhdr
*eth
= (struct ethhdr
*)skb_push(skb
, ETH_HLEN
);
84 if (type
!= ETH_P_802_3
&& type
!= ETH_P_802_2
)
85 eth
->h_proto
= htons(type
);
87 eth
->h_proto
= htons(len
);
90 * Set the source hardware address.
94 saddr
= dev
->dev_addr
;
95 memcpy(eth
->h_source
, saddr
, ETH_ALEN
);
98 memcpy(eth
->h_dest
, daddr
, ETH_ALEN
);
103 * Anyway, the loopback-device should never use this function...
106 if (dev
->flags
& (IFF_LOOPBACK
| IFF_NOARP
)) {
107 memset(eth
->h_dest
, 0, ETH_ALEN
);
113 EXPORT_SYMBOL(eth_header
);
116 * eth_rebuild_header- rebuild the Ethernet MAC header.
117 * @skb: socket buffer to update
119 * This is called after an ARP or IPV6 ndisc it's resolution on this
120 * sk_buff. We now let protocol (ARP) fill in the other fields.
122 * This routine CANNOT use cached dst->neigh!
123 * Really, it is used only when dst->neigh is wrong.
125 int eth_rebuild_header(struct sk_buff
*skb
)
127 struct ethhdr
*eth
= (struct ethhdr
*)skb
->data
;
128 struct net_device
*dev
= skb
->dev
;
130 switch (eth
->h_proto
) {
132 case htons(ETH_P_IP
):
133 return arp_find(eth
->h_dest
, skb
);
137 "%s: unable to resolve type %X addresses.\n",
138 dev
->name
, ntohs(eth
->h_proto
));
140 memcpy(eth
->h_source
, dev
->dev_addr
, ETH_ALEN
);
146 EXPORT_SYMBOL(eth_rebuild_header
);
149 * eth_get_headlen - determine the the length of header for an ethernet frame
150 * @data: pointer to start of frame
151 * @len: total length of frame
153 * Make a best effort attempt to pull the length for all of the headers for
154 * a given frame in a linear buffer.
156 u32
eth_get_headlen(void *data
, unsigned int len
)
158 const struct ethhdr
*eth
= (const struct ethhdr
*)data
;
159 struct flow_keys keys
;
161 /* this should never happen, but better safe than sorry */
162 if (len
< sizeof(*eth
))
165 /* parse any remaining L2/L3 headers, check for L4 */
166 if (!__skb_flow_dissect(NULL
, &keys
, data
,
167 eth
->h_proto
, sizeof(*eth
), len
))
168 return max_t(u32
, keys
.thoff
, sizeof(*eth
));
170 /* parse for any L4 headers */
171 return min_t(u32
, __skb_get_poff(NULL
, data
, &keys
, len
), len
);
173 EXPORT_SYMBOL(eth_get_headlen
);
176 * eth_type_trans - determine the packet's protocol ID.
177 * @skb: received socket data
178 * @dev: receiving network device
180 * The rule here is that we
181 * assume 802.3 if the type field is short enough to be a length.
182 * This is normal practice and works for any 'now in use' protocol.
184 __be16
eth_type_trans(struct sk_buff
*skb
, struct net_device
*dev
)
186 unsigned short _service_access_point
;
187 const unsigned short *sap
;
188 const struct ethhdr
*eth
;
191 skb_reset_mac_header(skb
);
192 skb_pull_inline(skb
, ETH_HLEN
);
195 if (unlikely(is_multicast_ether_addr(eth
->h_dest
))) {
196 if (ether_addr_equal_64bits(eth
->h_dest
, dev
->broadcast
))
197 skb
->pkt_type
= PACKET_BROADCAST
;
199 skb
->pkt_type
= PACKET_MULTICAST
;
201 else if (unlikely(!ether_addr_equal_64bits(eth
->h_dest
,
203 skb
->pkt_type
= PACKET_OTHERHOST
;
206 * Some variants of DSA tagging don't have an ethertype field
207 * at all, so we check here whether one of those tagging
208 * variants has been configured on the receiving interface,
209 * and if so, set skb->protocol without looking at the packet.
211 if (unlikely(netdev_uses_dsa(dev
)))
212 return htons(ETH_P_XDSA
);
214 if (likely(ntohs(eth
->h_proto
) >= ETH_P_802_3_MIN
))
218 * This is a magic hack to spot IPX packets. Older Novell breaks
219 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
220 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
221 * won't work for fault tolerant netware but does for the rest.
223 sap
= skb_header_pointer(skb
, 0, sizeof(*sap
), &_service_access_point
);
224 if (sap
&& *sap
== 0xFFFF)
225 return htons(ETH_P_802_3
);
230 return htons(ETH_P_802_2
);
232 EXPORT_SYMBOL(eth_type_trans
);
235 * eth_header_parse - extract hardware address from packet
236 * @skb: packet to extract header from
237 * @haddr: destination buffer
239 int eth_header_parse(const struct sk_buff
*skb
, unsigned char *haddr
)
241 const struct ethhdr
*eth
= eth_hdr(skb
);
242 memcpy(haddr
, eth
->h_source
, ETH_ALEN
);
245 EXPORT_SYMBOL(eth_header_parse
);
248 * eth_header_cache - fill cache entry from neighbour
249 * @neigh: source neighbour
250 * @hh: destination cache entry
251 * @type: Ethernet type field
253 * Create an Ethernet header template from the neighbour.
255 int eth_header_cache(const struct neighbour
*neigh
, struct hh_cache
*hh
, __be16 type
)
258 const struct net_device
*dev
= neigh
->dev
;
260 eth
= (struct ethhdr
*)
261 (((u8
*) hh
->hh_data
) + (HH_DATA_OFF(sizeof(*eth
))));
263 if (type
== htons(ETH_P_802_3
))
267 memcpy(eth
->h_source
, dev
->dev_addr
, ETH_ALEN
);
268 memcpy(eth
->h_dest
, neigh
->ha
, ETH_ALEN
);
269 hh
->hh_len
= ETH_HLEN
;
272 EXPORT_SYMBOL(eth_header_cache
);
275 * eth_header_cache_update - update cache entry
276 * @hh: destination cache entry
277 * @dev: network device
278 * @haddr: new hardware address
280 * Called by Address Resolution module to notify changes in address.
282 void eth_header_cache_update(struct hh_cache
*hh
,
283 const struct net_device
*dev
,
284 const unsigned char *haddr
)
286 memcpy(((u8
*) hh
->hh_data
) + HH_DATA_OFF(sizeof(struct ethhdr
)),
289 EXPORT_SYMBOL(eth_header_cache_update
);
292 * eth_prepare_mac_addr_change - prepare for mac change
293 * @dev: network device
296 int eth_prepare_mac_addr_change(struct net_device
*dev
, void *p
)
298 struct sockaddr
*addr
= p
;
300 if (!(dev
->priv_flags
& IFF_LIVE_ADDR_CHANGE
) && netif_running(dev
))
302 if (!is_valid_ether_addr(addr
->sa_data
))
303 return -EADDRNOTAVAIL
;
306 EXPORT_SYMBOL(eth_prepare_mac_addr_change
);
309 * eth_commit_mac_addr_change - commit mac change
310 * @dev: network device
313 void eth_commit_mac_addr_change(struct net_device
*dev
, void *p
)
315 struct sockaddr
*addr
= p
;
317 memcpy(dev
->dev_addr
, addr
->sa_data
, ETH_ALEN
);
319 EXPORT_SYMBOL(eth_commit_mac_addr_change
);
322 * eth_mac_addr - set new Ethernet hardware address
323 * @dev: network device
326 * Change hardware address of device.
328 * This doesn't change hardware matching, so needs to be overridden
329 * for most real devices.
331 int eth_mac_addr(struct net_device
*dev
, void *p
)
335 ret
= eth_prepare_mac_addr_change(dev
, p
);
338 eth_commit_mac_addr_change(dev
, p
);
341 EXPORT_SYMBOL(eth_mac_addr
);
344 * eth_change_mtu - set new MTU size
345 * @dev: network device
346 * @new_mtu: new Maximum Transfer Unit
348 * Allow changing MTU size. Needs to be overridden for devices
349 * supporting jumbo frames.
351 int eth_change_mtu(struct net_device
*dev
, int new_mtu
)
353 if (new_mtu
< 68 || new_mtu
> ETH_DATA_LEN
)
358 EXPORT_SYMBOL(eth_change_mtu
);
360 int eth_validate_addr(struct net_device
*dev
)
362 if (!is_valid_ether_addr(dev
->dev_addr
))
363 return -EADDRNOTAVAIL
;
367 EXPORT_SYMBOL(eth_validate_addr
);
369 const struct header_ops eth_header_ops ____cacheline_aligned
= {
370 .create
= eth_header
,
371 .parse
= eth_header_parse
,
372 .rebuild
= eth_rebuild_header
,
373 .cache
= eth_header_cache
,
374 .cache_update
= eth_header_cache_update
,
378 * ether_setup - setup Ethernet network device
379 * @dev: network device
381 * Fill in the fields of the device structure with Ethernet-generic values.
383 void ether_setup(struct net_device
*dev
)
385 dev
->header_ops
= ð_header_ops
;
386 dev
->type
= ARPHRD_ETHER
;
387 dev
->hard_header_len
= ETH_HLEN
;
388 dev
->mtu
= ETH_DATA_LEN
;
389 dev
->addr_len
= ETH_ALEN
;
390 dev
->tx_queue_len
= 1000; /* Ethernet wants good queues */
391 dev
->flags
= IFF_BROADCAST
|IFF_MULTICAST
;
392 dev
->priv_flags
|= IFF_TX_SKB_SHARING
;
394 memset(dev
->broadcast
, 0xFF, ETH_ALEN
);
397 EXPORT_SYMBOL(ether_setup
);
400 * alloc_etherdev_mqs - Allocates and sets up an Ethernet device
401 * @sizeof_priv: Size of additional driver-private structure to be allocated
402 * for this Ethernet device
403 * @txqs: The number of TX queues this device has.
404 * @rxqs: The number of RX queues this device has.
406 * Fill in the fields of the device structure with Ethernet-generic
407 * values. Basically does everything except registering the device.
409 * Constructs a new net device, complete with a private data area of
410 * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for
411 * this private data area.
414 struct net_device
*alloc_etherdev_mqs(int sizeof_priv
, unsigned int txqs
,
417 return alloc_netdev_mqs(sizeof_priv
, "eth%d", NET_NAME_UNKNOWN
,
418 ether_setup
, txqs
, rxqs
);
420 EXPORT_SYMBOL(alloc_etherdev_mqs
);
422 ssize_t
sysfs_format_mac(char *buf
, const unsigned char *addr
, int len
)
424 return scnprintf(buf
, PAGE_SIZE
, "%*phC\n", len
, addr
);
426 EXPORT_SYMBOL(sysfs_format_mac
);
428 struct sk_buff
**eth_gro_receive(struct sk_buff
**head
,
431 struct sk_buff
*p
, **pp
= NULL
;
432 struct ethhdr
*eh
, *eh2
;
433 unsigned int hlen
, off_eth
;
434 const struct packet_offload
*ptype
;
438 off_eth
= skb_gro_offset(skb
);
439 hlen
= off_eth
+ sizeof(*eh
);
440 eh
= skb_gro_header_fast(skb
, off_eth
);
441 if (skb_gro_header_hard(skb
, hlen
)) {
442 eh
= skb_gro_header_slow(skb
, hlen
, off_eth
);
449 for (p
= *head
; p
; p
= p
->next
) {
450 if (!NAPI_GRO_CB(p
)->same_flow
)
453 eh2
= (struct ethhdr
*)(p
->data
+ off_eth
);
454 if (compare_ether_header(eh
, eh2
)) {
455 NAPI_GRO_CB(p
)->same_flow
= 0;
463 ptype
= gro_find_receive_by_type(type
);
469 skb_gro_pull(skb
, sizeof(*eh
));
470 skb_gro_postpull_rcsum(skb
, eh
, sizeof(*eh
));
471 pp
= ptype
->callbacks
.gro_receive(head
, skb
);
476 NAPI_GRO_CB(skb
)->flush
|= flush
;
480 EXPORT_SYMBOL(eth_gro_receive
);
482 int eth_gro_complete(struct sk_buff
*skb
, int nhoff
)
484 struct ethhdr
*eh
= (struct ethhdr
*)(skb
->data
+ nhoff
);
485 __be16 type
= eh
->h_proto
;
486 struct packet_offload
*ptype
;
489 if (skb
->encapsulation
)
490 skb_set_inner_mac_header(skb
, nhoff
);
493 ptype
= gro_find_complete_by_type(type
);
495 err
= ptype
->callbacks
.gro_complete(skb
, nhoff
+
496 sizeof(struct ethhdr
));
501 EXPORT_SYMBOL(eth_gro_complete
);
503 static struct packet_offload eth_packet_offload __read_mostly
= {
504 .type
= cpu_to_be16(ETH_P_TEB
),
506 .gro_receive
= eth_gro_receive
,
507 .gro_complete
= eth_gro_complete
,
511 static int __init
eth_offload_init(void)
513 dev_add_offload(ð_packet_offload
);
518 fs_initcall(eth_offload_init
);