Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-or-later
2 : /*
3 : * INET An implementation of the TCP/IP protocol suite for the LINUX
4 : * operating system. INET is implemented using the BSD Socket
5 : * interface as the means of communication with the user level.
6 : *
7 : * Ethernet-type device handling.
8 : *
9 : * Version: @(#)eth.c 1.0.7 05/25/93
10 : *
11 : * Authors: Ross Biro
12 : * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 : * Mark Evans, <evansmp@uhura.aston.ac.uk>
14 : * Florian La Roche, <rzsfl@rz.uni-sb.de>
15 : * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 : *
17 : * Fixes:
18 : * Mr Linux : Arp problems
19 : * Alan Cox : Generic queue tidyup (very tiny here)
20 : * Alan Cox : eth_header ntohs should be htons
21 : * Alan Cox : eth_rebuild_header missing an htons and
22 : * minor other things.
23 : * Tegge : Arp bug fixes.
24 : * Florian : Removed many unnecessary functions, code cleanup
25 : * and changes for new arp and skbuff.
26 : * Alan Cox : Redid header building to reflect new format.
27 : * Alan Cox : ARP only when compiled with CONFIG_INET
28 : * Greg Page : 802.2 and SNAP stuff.
29 : * Alan Cox : MAC layer pointers/new format.
30 : * Paul Gortmaker : eth_copy_and_sum shouldn't csum padding.
31 : * Alan Cox : Protect against forwarding explosions with
32 : * older network drivers and IFF_ALLMULTI.
33 : * Christer Weinigel : Better rebuild header message.
34 : * Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup().
35 : */
36 : #include <linux/module.h>
37 : #include <linux/types.h>
38 : #include <linux/kernel.h>
39 : #include <linux/string.h>
40 : #include <linux/mm.h>
41 : #include <linux/socket.h>
42 : #include <linux/in.h>
43 : #include <linux/inet.h>
44 : #include <linux/ip.h>
45 : #include <linux/netdevice.h>
46 : #include <linux/nvmem-consumer.h>
47 : #include <linux/etherdevice.h>
48 : #include <linux/skbuff.h>
49 : #include <linux/errno.h>
50 : #include <linux/init.h>
51 : #include <linux/if_ether.h>
52 : #include <linux/of_net.h>
53 : #include <linux/pci.h>
54 : #include <net/dst.h>
55 : #include <net/arp.h>
56 : #include <net/sock.h>
57 : #include <net/ipv6.h>
58 : #include <net/ip.h>
59 : #include <net/dsa.h>
60 : #include <net/flow_dissector.h>
61 : #include <linux/uaccess.h>
62 : #include <net/pkt_sched.h>
63 :
64 : __setup("ether=", netdev_boot_setup);
65 :
66 : /**
67 : * eth_header - create the Ethernet header
68 : * @skb: buffer to alter
69 : * @dev: source device
70 : * @type: Ethernet type field
71 : * @daddr: destination address (NULL leave destination address)
72 : * @saddr: source address (NULL use device source address)
73 : * @len: packet length (<= skb->len)
74 : *
75 : *
76 : * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
77 : * in here instead.
78 : */
79 9 : int eth_header(struct sk_buff *skb, struct net_device *dev,
80 : unsigned short type,
81 : const void *daddr, const void *saddr, unsigned int len)
82 : {
83 9 : struct ethhdr *eth = skb_push(skb, ETH_HLEN);
84 :
85 9 : if (type != ETH_P_802_3 && type != ETH_P_802_2)
86 9 : eth->h_proto = htons(type);
87 : else
88 0 : eth->h_proto = htons(len);
89 :
90 : /*
91 : * Set the source hardware address.
92 : */
93 :
94 9 : if (!saddr)
95 6 : saddr = dev->dev_addr;
96 9 : memcpy(eth->h_source, saddr, ETH_ALEN);
97 :
98 9 : if (daddr) {
99 9 : memcpy(eth->h_dest, daddr, ETH_ALEN);
100 9 : return ETH_HLEN;
101 : }
102 :
103 : /*
104 : * Anyway, the loopback-device should never use this function...
105 : */
106 :
107 0 : if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
108 0 : eth_zero_addr(eth->h_dest);
109 0 : return ETH_HLEN;
110 : }
111 :
112 : return -ETH_HLEN;
113 : }
114 : EXPORT_SYMBOL(eth_header);
115 :
116 : /**
117 : * eth_get_headlen - determine the length of header for an ethernet frame
118 : * @dev: pointer to network device
119 : * @data: pointer to start of frame
120 : * @len: total length of frame
121 : *
122 : * Make a best effort attempt to pull the length for all of the headers for
123 : * a given frame in a linear buffer.
124 : */
125 0 : u32 eth_get_headlen(const struct net_device *dev, void *data, unsigned int len)
126 : {
127 0 : const unsigned int flags = FLOW_DISSECTOR_F_PARSE_1ST_FRAG;
128 0 : const struct ethhdr *eth = (const struct ethhdr *)data;
129 0 : struct flow_keys_basic keys;
130 :
131 : /* this should never happen, but better safe than sorry */
132 0 : if (unlikely(len < sizeof(*eth)))
133 : return len;
134 :
135 : /* parse any remaining L2/L3 headers, check for L4 */
136 0 : if (!skb_flow_dissect_flow_keys_basic(dev_net(dev), NULL, &keys, data,
137 0 : eth->h_proto, sizeof(*eth),
138 : len, flags))
139 0 : return max_t(u32, keys.control.thoff, sizeof(*eth));
140 :
141 : /* parse for any L4 headers */
142 0 : return min_t(u32, __skb_get_poff(NULL, data, &keys, len), len);
143 : }
144 : EXPORT_SYMBOL(eth_get_headlen);
145 :
146 : /**
147 : * eth_type_trans - determine the packet's protocol ID.
148 : * @skb: received socket data
149 : * @dev: receiving network device
150 : *
151 : * The rule here is that we
152 : * assume 802.3 if the type field is short enough to be a length.
153 : * This is normal practice and works for any 'now in use' protocol.
154 : */
155 723 : __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
156 : {
157 723 : unsigned short _service_access_point;
158 723 : const unsigned short *sap;
159 723 : const struct ethhdr *eth;
160 :
161 723 : skb->dev = dev;
162 723 : skb_reset_mac_header(skb);
163 :
164 723 : eth = (struct ethhdr *)skb->data;
165 723 : skb_pull_inline(skb, ETH_HLEN);
166 :
167 723 : if (unlikely(!ether_addr_equal_64bits(eth->h_dest,
168 : dev->dev_addr))) {
169 2 : if (unlikely(is_multicast_ether_addr_64bits(eth->h_dest))) {
170 2 : if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
171 2 : skb->pkt_type = PACKET_BROADCAST;
172 : else
173 0 : skb->pkt_type = PACKET_MULTICAST;
174 : } else {
175 0 : skb->pkt_type = PACKET_OTHERHOST;
176 : }
177 : }
178 :
179 : /*
180 : * Some variants of DSA tagging don't have an ethertype field
181 : * at all, so we check here whether one of those tagging
182 : * variants has been configured on the receiving interface,
183 : * and if so, set skb->protocol without looking at the packet.
184 : * The DSA tagging protocol may be able to decode some but not all
185 : * traffic (for example only for management). In that case give it the
186 : * option to filter the packets from which it can decode source port
187 : * information.
188 : */
189 723 : if (unlikely(netdev_uses_dsa(dev)) && dsa_can_decode(skb, dev))
190 : return htons(ETH_P_XDSA);
191 :
192 723 : if (likely(eth_proto_is_802_3(eth->h_proto)))
193 : return eth->h_proto;
194 :
195 : /*
196 : * This is a magic hack to spot IPX packets. Older Novell breaks
197 : * the protocol design and runs IPX over 802.3 without an 802.2 LLC
198 : * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
199 : * won't work for fault tolerant netware but does for the rest.
200 : */
201 0 : sap = skb_header_pointer(skb, 0, sizeof(*sap), &_service_access_point);
202 0 : if (sap && *sap == 0xFFFF)
203 0 : return htons(ETH_P_802_3);
204 :
205 : /*
206 : * Real 802.2 LLC
207 : */
208 : return htons(ETH_P_802_2);
209 : }
210 : EXPORT_SYMBOL(eth_type_trans);
211 :
212 : /**
213 : * eth_header_parse - extract hardware address from packet
214 : * @skb: packet to extract header from
215 : * @haddr: destination buffer
216 : */
217 2 : int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr)
218 : {
219 2 : const struct ethhdr *eth = eth_hdr(skb);
220 2 : memcpy(haddr, eth->h_source, ETH_ALEN);
221 2 : return ETH_ALEN;
222 : }
223 : EXPORT_SYMBOL(eth_header_parse);
224 :
225 : /**
226 : * eth_header_cache - fill cache entry from neighbour
227 : * @neigh: source neighbour
228 : * @hh: destination cache entry
229 : * @type: Ethernet type field
230 : *
231 : * Create an Ethernet header template from the neighbour.
232 : */
233 2 : int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type)
234 : {
235 2 : struct ethhdr *eth;
236 2 : const struct net_device *dev = neigh->dev;
237 :
238 2 : eth = (struct ethhdr *)
239 : (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
240 :
241 2 : if (type == htons(ETH_P_802_3))
242 : return -1;
243 :
244 2 : eth->h_proto = type;
245 2 : memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
246 2 : memcpy(eth->h_dest, neigh->ha, ETH_ALEN);
247 :
248 : /* Pairs with READ_ONCE() in neigh_resolve_output(),
249 : * neigh_hh_output() and neigh_update_hhs().
250 : */
251 2 : smp_store_release(&hh->hh_len, ETH_HLEN);
252 :
253 2 : return 0;
254 : }
255 : EXPORT_SYMBOL(eth_header_cache);
256 :
257 : /**
258 : * eth_header_cache_update - update cache entry
259 : * @hh: destination cache entry
260 : * @dev: network device
261 : * @haddr: new hardware address
262 : *
263 : * Called by Address Resolution module to notify changes in address.
264 : */
265 0 : void eth_header_cache_update(struct hh_cache *hh,
266 : const struct net_device *dev,
267 : const unsigned char *haddr)
268 : {
269 0 : memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
270 : haddr, ETH_ALEN);
271 0 : }
272 : EXPORT_SYMBOL(eth_header_cache_update);
273 :
274 : /**
275 : * eth_header_parse_protocol - extract protocol from L2 header
276 : * @skb: packet to extract protocol from
277 : */
278 2 : __be16 eth_header_parse_protocol(const struct sk_buff *skb)
279 : {
280 2 : const struct ethhdr *eth = eth_hdr(skb);
281 :
282 2 : return eth->h_proto;
283 : }
284 : EXPORT_SYMBOL(eth_header_parse_protocol);
285 :
286 : /**
287 : * eth_prepare_mac_addr_change - prepare for mac change
288 : * @dev: network device
289 : * @p: socket address
290 : */
291 0 : int eth_prepare_mac_addr_change(struct net_device *dev, void *p)
292 : {
293 0 : struct sockaddr *addr = p;
294 :
295 0 : if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
296 : return -EBUSY;
297 0 : if (!is_valid_ether_addr(addr->sa_data))
298 0 : return -EADDRNOTAVAIL;
299 : return 0;
300 : }
301 : EXPORT_SYMBOL(eth_prepare_mac_addr_change);
302 :
303 : /**
304 : * eth_commit_mac_addr_change - commit mac change
305 : * @dev: network device
306 : * @p: socket address
307 : */
308 0 : void eth_commit_mac_addr_change(struct net_device *dev, void *p)
309 : {
310 0 : struct sockaddr *addr = p;
311 :
312 0 : memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
313 0 : }
314 : EXPORT_SYMBOL(eth_commit_mac_addr_change);
315 :
316 : /**
317 : * eth_mac_addr - set new Ethernet hardware address
318 : * @dev: network device
319 : * @p: socket address
320 : *
321 : * Change hardware address of device.
322 : *
323 : * This doesn't change hardware matching, so needs to be overridden
324 : * for most real devices.
325 : */
326 0 : int eth_mac_addr(struct net_device *dev, void *p)
327 : {
328 0 : int ret;
329 :
330 0 : ret = eth_prepare_mac_addr_change(dev, p);
331 0 : if (ret < 0)
332 : return ret;
333 0 : eth_commit_mac_addr_change(dev, p);
334 0 : return 0;
335 : }
336 : EXPORT_SYMBOL(eth_mac_addr);
337 :
338 1 : int eth_validate_addr(struct net_device *dev)
339 : {
340 2 : if (!is_valid_ether_addr(dev->dev_addr))
341 0 : return -EADDRNOTAVAIL;
342 :
343 : return 0;
344 : }
345 : EXPORT_SYMBOL(eth_validate_addr);
346 :
347 : const struct header_ops eth_header_ops ____cacheline_aligned = {
348 : .create = eth_header,
349 : .parse = eth_header_parse,
350 : .cache = eth_header_cache,
351 : .cache_update = eth_header_cache_update,
352 : .parse_protocol = eth_header_parse_protocol,
353 : };
354 :
355 : /**
356 : * ether_setup - setup Ethernet network device
357 : * @dev: network device
358 : *
359 : * Fill in the fields of the device structure with Ethernet-generic values.
360 : */
361 1 : void ether_setup(struct net_device *dev)
362 : {
363 1 : dev->header_ops = ð_header_ops;
364 1 : dev->type = ARPHRD_ETHER;
365 1 : dev->hard_header_len = ETH_HLEN;
366 1 : dev->min_header_len = ETH_HLEN;
367 1 : dev->mtu = ETH_DATA_LEN;
368 1 : dev->min_mtu = ETH_MIN_MTU;
369 1 : dev->max_mtu = ETH_DATA_LEN;
370 1 : dev->addr_len = ETH_ALEN;
371 1 : dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
372 1 : dev->flags = IFF_BROADCAST|IFF_MULTICAST;
373 1 : dev->priv_flags |= IFF_TX_SKB_SHARING;
374 :
375 1 : eth_broadcast_addr(dev->broadcast);
376 :
377 1 : }
378 : EXPORT_SYMBOL(ether_setup);
379 :
380 : /**
381 : * alloc_etherdev_mqs - Allocates and sets up an Ethernet device
382 : * @sizeof_priv: Size of additional driver-private structure to be allocated
383 : * for this Ethernet device
384 : * @txqs: The number of TX queues this device has.
385 : * @rxqs: The number of RX queues this device has.
386 : *
387 : * Fill in the fields of the device structure with Ethernet-generic
388 : * values. Basically does everything except registering the device.
389 : *
390 : * Constructs a new net device, complete with a private data area of
391 : * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for
392 : * this private data area.
393 : */
394 :
395 1 : struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
396 : unsigned int rxqs)
397 : {
398 1 : return alloc_netdev_mqs(sizeof_priv, "eth%d", NET_NAME_UNKNOWN,
399 : ether_setup, txqs, rxqs);
400 : }
401 : EXPORT_SYMBOL(alloc_etherdev_mqs);
402 :
403 2 : ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
404 : {
405 2 : return scnprintf(buf, PAGE_SIZE, "%*phC\n", len, addr);
406 : }
407 : EXPORT_SYMBOL(sysfs_format_mac);
408 :
409 0 : struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb)
410 : {
411 0 : const struct packet_offload *ptype;
412 0 : unsigned int hlen, off_eth;
413 0 : struct sk_buff *pp = NULL;
414 0 : struct ethhdr *eh, *eh2;
415 0 : struct sk_buff *p;
416 0 : __be16 type;
417 0 : int flush = 1;
418 :
419 0 : off_eth = skb_gro_offset(skb);
420 0 : hlen = off_eth + sizeof(*eh);
421 0 : eh = skb_gro_header_fast(skb, off_eth);
422 0 : if (skb_gro_header_hard(skb, hlen)) {
423 0 : eh = skb_gro_header_slow(skb, hlen, off_eth);
424 0 : if (unlikely(!eh))
425 0 : goto out;
426 : }
427 :
428 0 : flush = 0;
429 :
430 0 : list_for_each_entry(p, head, list) {
431 0 : if (!NAPI_GRO_CB(p)->same_flow)
432 0 : continue;
433 :
434 0 : eh2 = (struct ethhdr *)(p->data + off_eth);
435 0 : if (compare_ether_header(eh, eh2)) {
436 0 : NAPI_GRO_CB(p)->same_flow = 0;
437 0 : continue;
438 : }
439 : }
440 :
441 0 : type = eh->h_proto;
442 :
443 0 : rcu_read_lock();
444 0 : ptype = gro_find_receive_by_type(type);
445 0 : if (ptype == NULL) {
446 0 : flush = 1;
447 0 : goto out_unlock;
448 : }
449 :
450 0 : skb_gro_pull(skb, sizeof(*eh));
451 0 : skb_gro_postpull_rcsum(skb, eh, sizeof(*eh));
452 0 : pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
453 :
454 0 : out_unlock:
455 0 : rcu_read_unlock();
456 0 : out:
457 0 : skb_gro_flush_final(skb, pp, flush);
458 :
459 0 : return pp;
460 : }
461 : EXPORT_SYMBOL(eth_gro_receive);
462 :
463 0 : int eth_gro_complete(struct sk_buff *skb, int nhoff)
464 : {
465 0 : struct ethhdr *eh = (struct ethhdr *)(skb->data + nhoff);
466 0 : __be16 type = eh->h_proto;
467 0 : struct packet_offload *ptype;
468 0 : int err = -ENOSYS;
469 :
470 0 : if (skb->encapsulation)
471 0 : skb_set_inner_mac_header(skb, nhoff);
472 :
473 0 : rcu_read_lock();
474 0 : ptype = gro_find_complete_by_type(type);
475 0 : if (ptype != NULL)
476 0 : err = ptype->callbacks.gro_complete(skb, nhoff +
477 : sizeof(struct ethhdr));
478 :
479 0 : rcu_read_unlock();
480 0 : return err;
481 : }
482 : EXPORT_SYMBOL(eth_gro_complete);
483 :
484 : static struct packet_offload eth_packet_offload __read_mostly = {
485 : .type = cpu_to_be16(ETH_P_TEB),
486 : .priority = 10,
487 : .callbacks = {
488 : .gro_receive = eth_gro_receive,
489 : .gro_complete = eth_gro_complete,
490 : },
491 : };
492 :
493 1 : static int __init eth_offload_init(void)
494 : {
495 1 : dev_add_offload(ð_packet_offload);
496 :
497 1 : return 0;
498 : }
499 :
500 : fs_initcall(eth_offload_init);
501 :
502 0 : unsigned char * __weak arch_get_platform_mac_address(void)
503 : {
504 0 : return NULL;
505 : }
506 :
507 0 : int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
508 : {
509 0 : const unsigned char *addr = NULL;
510 :
511 0 : if (dev->of_node)
512 0 : addr = of_get_mac_address(dev->of_node);
513 0 : if (IS_ERR_OR_NULL(addr))
514 0 : addr = arch_get_platform_mac_address();
515 :
516 0 : if (!addr)
517 : return -ENODEV;
518 :
519 0 : ether_addr_copy(mac_addr, addr);
520 :
521 0 : return 0;
522 : }
523 : EXPORT_SYMBOL(eth_platform_get_mac_address);
524 :
525 : /**
526 : * nvmem_get_mac_address - Obtain the MAC address from an nvmem cell named
527 : * 'mac-address' associated with given device.
528 : *
529 : * @dev: Device with which the mac-address cell is associated.
530 : * @addrbuf: Buffer to which the MAC address will be copied on success.
531 : *
532 : * Returns 0 on success or a negative error number on failure.
533 : */
534 0 : int nvmem_get_mac_address(struct device *dev, void *addrbuf)
535 : {
536 0 : struct nvmem_cell *cell;
537 0 : const void *mac;
538 0 : size_t len;
539 :
540 0 : cell = nvmem_cell_get(dev, "mac-address");
541 0 : if (IS_ERR(cell))
542 0 : return PTR_ERR(cell);
543 :
544 : mac = nvmem_cell_read(cell, &len);
545 : nvmem_cell_put(cell);
546 :
547 : if (IS_ERR(mac))
548 : return PTR_ERR(mac);
549 :
550 : if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
551 : kfree(mac);
552 : return -EINVAL;
553 : }
554 :
555 : ether_addr_copy(addrbuf, mac);
556 : kfree(mac);
557 :
558 : return 0;
559 : }
560 : EXPORT_SYMBOL(nvmem_get_mac_address);
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