xref: /openbmc/linux/drivers/net/bonding/bond_alb.c (revision a06c488d)
1 /*
2  * Copyright(c) 1999 - 2004 Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the
6  * Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  * You should have received a copy of the GNU General Public License along
15  * with this program; if not, see <http://www.gnu.org/licenses/>.
16  *
17  * The full GNU General Public License is included in this distribution in the
18  * file called LICENSE.
19  *
20  */
21 
22 #include <linux/skbuff.h>
23 #include <linux/netdevice.h>
24 #include <linux/etherdevice.h>
25 #include <linux/pkt_sched.h>
26 #include <linux/spinlock.h>
27 #include <linux/slab.h>
28 #include <linux/timer.h>
29 #include <linux/ip.h>
30 #include <linux/ipv6.h>
31 #include <linux/if_arp.h>
32 #include <linux/if_ether.h>
33 #include <linux/if_bonding.h>
34 #include <linux/if_vlan.h>
35 #include <linux/in.h>
36 #include <net/ipx.h>
37 #include <net/arp.h>
38 #include <net/ipv6.h>
39 #include <asm/byteorder.h>
40 #include <net/bonding.h>
41 #include <net/bond_alb.h>
42 
43 
44 
45 #ifndef __long_aligned
46 #define __long_aligned __attribute__((aligned((sizeof(long)))))
47 #endif
48 static const u8 mac_bcast[ETH_ALEN] __long_aligned = {
49 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff
50 };
51 static const u8 mac_v6_allmcast[ETH_ALEN] __long_aligned = {
52 	0x33, 0x33, 0x00, 0x00, 0x00, 0x01
53 };
54 static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;
55 
56 #pragma pack(1)
57 struct learning_pkt {
58 	u8 mac_dst[ETH_ALEN];
59 	u8 mac_src[ETH_ALEN];
60 	__be16 type;
61 	u8 padding[ETH_ZLEN - ETH_HLEN];
62 };
63 
64 struct arp_pkt {
65 	__be16  hw_addr_space;
66 	__be16  prot_addr_space;
67 	u8      hw_addr_len;
68 	u8      prot_addr_len;
69 	__be16  op_code;
70 	u8      mac_src[ETH_ALEN];	/* sender hardware address */
71 	__be32  ip_src;			/* sender IP address */
72 	u8      mac_dst[ETH_ALEN];	/* target hardware address */
73 	__be32  ip_dst;			/* target IP address */
74 };
75 #pragma pack()
76 
77 static inline struct arp_pkt *arp_pkt(const struct sk_buff *skb)
78 {
79 	return (struct arp_pkt *)skb_network_header(skb);
80 }
81 
82 /* Forward declaration */
83 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[],
84 				      bool strict_match);
85 static void rlb_purge_src_ip(struct bonding *bond, struct arp_pkt *arp);
86 static void rlb_src_unlink(struct bonding *bond, u32 index);
87 static void rlb_src_link(struct bonding *bond, u32 ip_src_hash,
88 			 u32 ip_dst_hash);
89 
90 static inline u8 _simple_hash(const u8 *hash_start, int hash_size)
91 {
92 	int i;
93 	u8 hash = 0;
94 
95 	for (i = 0; i < hash_size; i++)
96 		hash ^= hash_start[i];
97 
98 	return hash;
99 }
100 
101 /*********************** tlb specific functions ***************************/
102 
103 static inline void tlb_init_table_entry(struct tlb_client_info *entry, int save_load)
104 {
105 	if (save_load) {
106 		entry->load_history = 1 + entry->tx_bytes /
107 				      BOND_TLB_REBALANCE_INTERVAL;
108 		entry->tx_bytes = 0;
109 	}
110 
111 	entry->tx_slave = NULL;
112 	entry->next = TLB_NULL_INDEX;
113 	entry->prev = TLB_NULL_INDEX;
114 }
115 
116 static inline void tlb_init_slave(struct slave *slave)
117 {
118 	SLAVE_TLB_INFO(slave).load = 0;
119 	SLAVE_TLB_INFO(slave).head = TLB_NULL_INDEX;
120 }
121 
122 static void __tlb_clear_slave(struct bonding *bond, struct slave *slave,
123 			 int save_load)
124 {
125 	struct tlb_client_info *tx_hash_table;
126 	u32 index;
127 
128 	/* clear slave from tx_hashtbl */
129 	tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl;
130 
131 	/* skip this if we've already freed the tx hash table */
132 	if (tx_hash_table) {
133 		index = SLAVE_TLB_INFO(slave).head;
134 		while (index != TLB_NULL_INDEX) {
135 			u32 next_index = tx_hash_table[index].next;
136 			tlb_init_table_entry(&tx_hash_table[index], save_load);
137 			index = next_index;
138 		}
139 	}
140 
141 	tlb_init_slave(slave);
142 }
143 
144 static void tlb_clear_slave(struct bonding *bond, struct slave *slave,
145 			 int save_load)
146 {
147 	spin_lock_bh(&bond->mode_lock);
148 	__tlb_clear_slave(bond, slave, save_load);
149 	spin_unlock_bh(&bond->mode_lock);
150 }
151 
152 /* Must be called before starting the monitor timer */
153 static int tlb_initialize(struct bonding *bond)
154 {
155 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
156 	int size = TLB_HASH_TABLE_SIZE * sizeof(struct tlb_client_info);
157 	struct tlb_client_info *new_hashtbl;
158 	int i;
159 
160 	new_hashtbl = kzalloc(size, GFP_KERNEL);
161 	if (!new_hashtbl)
162 		return -1;
163 
164 	spin_lock_bh(&bond->mode_lock);
165 
166 	bond_info->tx_hashtbl = new_hashtbl;
167 
168 	for (i = 0; i < TLB_HASH_TABLE_SIZE; i++)
169 		tlb_init_table_entry(&bond_info->tx_hashtbl[i], 0);
170 
171 	spin_unlock_bh(&bond->mode_lock);
172 
173 	return 0;
174 }
175 
176 /* Must be called only after all slaves have been released */
177 static void tlb_deinitialize(struct bonding *bond)
178 {
179 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
180 
181 	spin_lock_bh(&bond->mode_lock);
182 
183 	kfree(bond_info->tx_hashtbl);
184 	bond_info->tx_hashtbl = NULL;
185 
186 	spin_unlock_bh(&bond->mode_lock);
187 }
188 
189 static long long compute_gap(struct slave *slave)
190 {
191 	return (s64) (slave->speed << 20) - /* Convert to Megabit per sec */
192 	       (s64) (SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
193 }
194 
195 static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
196 {
197 	struct slave *slave, *least_loaded;
198 	struct list_head *iter;
199 	long long max_gap;
200 
201 	least_loaded = NULL;
202 	max_gap = LLONG_MIN;
203 
204 	/* Find the slave with the largest gap */
205 	bond_for_each_slave_rcu(bond, slave, iter) {
206 		if (bond_slave_can_tx(slave)) {
207 			long long gap = compute_gap(slave);
208 
209 			if (max_gap < gap) {
210 				least_loaded = slave;
211 				max_gap = gap;
212 			}
213 		}
214 	}
215 
216 	return least_loaded;
217 }
218 
219 static struct slave *__tlb_choose_channel(struct bonding *bond, u32 hash_index,
220 						u32 skb_len)
221 {
222 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
223 	struct tlb_client_info *hash_table;
224 	struct slave *assigned_slave;
225 
226 	hash_table = bond_info->tx_hashtbl;
227 	assigned_slave = hash_table[hash_index].tx_slave;
228 	if (!assigned_slave) {
229 		assigned_slave = tlb_get_least_loaded_slave(bond);
230 
231 		if (assigned_slave) {
232 			struct tlb_slave_info *slave_info =
233 				&(SLAVE_TLB_INFO(assigned_slave));
234 			u32 next_index = slave_info->head;
235 
236 			hash_table[hash_index].tx_slave = assigned_slave;
237 			hash_table[hash_index].next = next_index;
238 			hash_table[hash_index].prev = TLB_NULL_INDEX;
239 
240 			if (next_index != TLB_NULL_INDEX)
241 				hash_table[next_index].prev = hash_index;
242 
243 			slave_info->head = hash_index;
244 			slave_info->load +=
245 				hash_table[hash_index].load_history;
246 		}
247 	}
248 
249 	if (assigned_slave)
250 		hash_table[hash_index].tx_bytes += skb_len;
251 
252 	return assigned_slave;
253 }
254 
255 static struct slave *tlb_choose_channel(struct bonding *bond, u32 hash_index,
256 					u32 skb_len)
257 {
258 	struct slave *tx_slave;
259 
260 	/* We don't need to disable softirq here, becase
261 	 * tlb_choose_channel() is only called by bond_alb_xmit()
262 	 * which already has softirq disabled.
263 	 */
264 	spin_lock(&bond->mode_lock);
265 	tx_slave = __tlb_choose_channel(bond, hash_index, skb_len);
266 	spin_unlock(&bond->mode_lock);
267 
268 	return tx_slave;
269 }
270 
271 /*********************** rlb specific functions ***************************/
272 
273 /* when an ARP REPLY is received from a client update its info
274  * in the rx_hashtbl
275  */
276 static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
277 {
278 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
279 	struct rlb_client_info *client_info;
280 	u32 hash_index;
281 
282 	spin_lock_bh(&bond->mode_lock);
283 
284 	hash_index = _simple_hash((u8 *)&(arp->ip_src), sizeof(arp->ip_src));
285 	client_info = &(bond_info->rx_hashtbl[hash_index]);
286 
287 	if ((client_info->assigned) &&
288 	    (client_info->ip_src == arp->ip_dst) &&
289 	    (client_info->ip_dst == arp->ip_src) &&
290 	    (!ether_addr_equal_64bits(client_info->mac_dst, arp->mac_src))) {
291 		/* update the clients MAC address */
292 		ether_addr_copy(client_info->mac_dst, arp->mac_src);
293 		client_info->ntt = 1;
294 		bond_info->rx_ntt = 1;
295 	}
296 
297 	spin_unlock_bh(&bond->mode_lock);
298 }
299 
300 static int rlb_arp_recv(const struct sk_buff *skb, struct bonding *bond,
301 			struct slave *slave)
302 {
303 	struct arp_pkt *arp, _arp;
304 
305 	if (skb->protocol != cpu_to_be16(ETH_P_ARP))
306 		goto out;
307 
308 	arp = skb_header_pointer(skb, 0, sizeof(_arp), &_arp);
309 	if (!arp)
310 		goto out;
311 
312 	/* We received an ARP from arp->ip_src.
313 	 * We might have used this IP address previously (on the bonding host
314 	 * itself or on a system that is bridged together with the bond).
315 	 * However, if arp->mac_src is different than what is stored in
316 	 * rx_hashtbl, some other host is now using the IP and we must prevent
317 	 * sending out client updates with this IP address and the old MAC
318 	 * address.
319 	 * Clean up all hash table entries that have this address as ip_src but
320 	 * have a different mac_src.
321 	 */
322 	rlb_purge_src_ip(bond, arp);
323 
324 	if (arp->op_code == htons(ARPOP_REPLY)) {
325 		/* update rx hash table for this ARP */
326 		rlb_update_entry_from_arp(bond, arp);
327 		netdev_dbg(bond->dev, "Server received an ARP Reply from client\n");
328 	}
329 out:
330 	return RX_HANDLER_ANOTHER;
331 }
332 
333 /* Caller must hold rcu_read_lock() */
334 static struct slave *__rlb_next_rx_slave(struct bonding *bond)
335 {
336 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
337 	struct slave *before = NULL, *rx_slave = NULL, *slave;
338 	struct list_head *iter;
339 	bool found = false;
340 
341 	bond_for_each_slave_rcu(bond, slave, iter) {
342 		if (!bond_slave_can_tx(slave))
343 			continue;
344 		if (!found) {
345 			if (!before || before->speed < slave->speed)
346 				before = slave;
347 		} else {
348 			if (!rx_slave || rx_slave->speed < slave->speed)
349 				rx_slave = slave;
350 		}
351 		if (slave == bond_info->rx_slave)
352 			found = true;
353 	}
354 	/* we didn't find anything after the current or we have something
355 	 * better before and up to the current slave
356 	 */
357 	if (!rx_slave || (before && rx_slave->speed < before->speed))
358 		rx_slave = before;
359 
360 	if (rx_slave)
361 		bond_info->rx_slave = rx_slave;
362 
363 	return rx_slave;
364 }
365 
366 /* Caller must hold RTNL, rcu_read_lock is obtained only to silence checkers */
367 static struct slave *rlb_next_rx_slave(struct bonding *bond)
368 {
369 	struct slave *rx_slave;
370 
371 	ASSERT_RTNL();
372 
373 	rcu_read_lock();
374 	rx_slave = __rlb_next_rx_slave(bond);
375 	rcu_read_unlock();
376 
377 	return rx_slave;
378 }
379 
380 /* teach the switch the mac of a disabled slave
381  * on the primary for fault tolerance
382  *
383  * Caller must hold RTNL
384  */
385 static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
386 {
387 	struct slave *curr_active = rtnl_dereference(bond->curr_active_slave);
388 
389 	if (!curr_active)
390 		return;
391 
392 	if (!bond->alb_info.primary_is_promisc) {
393 		if (!dev_set_promiscuity(curr_active->dev, 1))
394 			bond->alb_info.primary_is_promisc = 1;
395 		else
396 			bond->alb_info.primary_is_promisc = 0;
397 	}
398 
399 	bond->alb_info.rlb_promisc_timeout_counter = 0;
400 
401 	alb_send_learning_packets(curr_active, addr, true);
402 }
403 
404 /* slave being removed should not be active at this point
405  *
406  * Caller must hold rtnl.
407  */
408 static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
409 {
410 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
411 	struct rlb_client_info *rx_hash_table;
412 	u32 index, next_index;
413 
414 	/* clear slave from rx_hashtbl */
415 	spin_lock_bh(&bond->mode_lock);
416 
417 	rx_hash_table = bond_info->rx_hashtbl;
418 	index = bond_info->rx_hashtbl_used_head;
419 	for (; index != RLB_NULL_INDEX; index = next_index) {
420 		next_index = rx_hash_table[index].used_next;
421 		if (rx_hash_table[index].slave == slave) {
422 			struct slave *assigned_slave = rlb_next_rx_slave(bond);
423 
424 			if (assigned_slave) {
425 				rx_hash_table[index].slave = assigned_slave;
426 				if (!ether_addr_equal_64bits(rx_hash_table[index].mac_dst,
427 							     mac_bcast)) {
428 					bond_info->rx_hashtbl[index].ntt = 1;
429 					bond_info->rx_ntt = 1;
430 					/* A slave has been removed from the
431 					 * table because it is either disabled
432 					 * or being released. We must retry the
433 					 * update to avoid clients from not
434 					 * being updated & disconnecting when
435 					 * there is stress
436 					 */
437 					bond_info->rlb_update_retry_counter =
438 						RLB_UPDATE_RETRY;
439 				}
440 			} else {  /* there is no active slave */
441 				rx_hash_table[index].slave = NULL;
442 			}
443 		}
444 	}
445 
446 	spin_unlock_bh(&bond->mode_lock);
447 
448 	if (slave != rtnl_dereference(bond->curr_active_slave))
449 		rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
450 }
451 
452 static void rlb_update_client(struct rlb_client_info *client_info)
453 {
454 	int i;
455 
456 	if (!client_info->slave)
457 		return;
458 
459 	for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
460 		struct sk_buff *skb;
461 
462 		skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
463 				 client_info->ip_dst,
464 				 client_info->slave->dev,
465 				 client_info->ip_src,
466 				 client_info->mac_dst,
467 				 client_info->slave->dev->dev_addr,
468 				 client_info->mac_dst);
469 		if (!skb) {
470 			netdev_err(client_info->slave->bond->dev,
471 				   "failed to create an ARP packet\n");
472 			continue;
473 		}
474 
475 		skb->dev = client_info->slave->dev;
476 
477 		if (client_info->vlan_id) {
478 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
479 					       client_info->vlan_id);
480 		}
481 
482 		arp_xmit(skb);
483 	}
484 }
485 
486 /* sends ARP REPLIES that update the clients that need updating */
487 static void rlb_update_rx_clients(struct bonding *bond)
488 {
489 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
490 	struct rlb_client_info *client_info;
491 	u32 hash_index;
492 
493 	spin_lock_bh(&bond->mode_lock);
494 
495 	hash_index = bond_info->rx_hashtbl_used_head;
496 	for (; hash_index != RLB_NULL_INDEX;
497 	     hash_index = client_info->used_next) {
498 		client_info = &(bond_info->rx_hashtbl[hash_index]);
499 		if (client_info->ntt) {
500 			rlb_update_client(client_info);
501 			if (bond_info->rlb_update_retry_counter == 0)
502 				client_info->ntt = 0;
503 		}
504 	}
505 
506 	/* do not update the entries again until this counter is zero so that
507 	 * not to confuse the clients.
508 	 */
509 	bond_info->rlb_update_delay_counter = RLB_UPDATE_DELAY;
510 
511 	spin_unlock_bh(&bond->mode_lock);
512 }
513 
514 /* The slave was assigned a new mac address - update the clients */
515 static void rlb_req_update_slave_clients(struct bonding *bond, struct slave *slave)
516 {
517 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
518 	struct rlb_client_info *client_info;
519 	int ntt = 0;
520 	u32 hash_index;
521 
522 	spin_lock_bh(&bond->mode_lock);
523 
524 	hash_index = bond_info->rx_hashtbl_used_head;
525 	for (; hash_index != RLB_NULL_INDEX;
526 	     hash_index = client_info->used_next) {
527 		client_info = &(bond_info->rx_hashtbl[hash_index]);
528 
529 		if ((client_info->slave == slave) &&
530 		    !ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
531 			client_info->ntt = 1;
532 			ntt = 1;
533 		}
534 	}
535 
536 	/* update the team's flag only after the whole iteration */
537 	if (ntt) {
538 		bond_info->rx_ntt = 1;
539 		/* fasten the change */
540 		bond_info->rlb_update_retry_counter = RLB_UPDATE_RETRY;
541 	}
542 
543 	spin_unlock_bh(&bond->mode_lock);
544 }
545 
546 /* mark all clients using src_ip to be updated */
547 static void rlb_req_update_subnet_clients(struct bonding *bond, __be32 src_ip)
548 {
549 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
550 	struct rlb_client_info *client_info;
551 	u32 hash_index;
552 
553 	spin_lock(&bond->mode_lock);
554 
555 	hash_index = bond_info->rx_hashtbl_used_head;
556 	for (; hash_index != RLB_NULL_INDEX;
557 	     hash_index = client_info->used_next) {
558 		client_info = &(bond_info->rx_hashtbl[hash_index]);
559 
560 		if (!client_info->slave) {
561 			netdev_err(bond->dev, "found a client with no channel in the client's hash table\n");
562 			continue;
563 		}
564 		/* update all clients using this src_ip, that are not assigned
565 		 * to the team's address (curr_active_slave) and have a known
566 		 * unicast mac address.
567 		 */
568 		if ((client_info->ip_src == src_ip) &&
569 		    !ether_addr_equal_64bits(client_info->slave->dev->dev_addr,
570 					     bond->dev->dev_addr) &&
571 		    !ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
572 			client_info->ntt = 1;
573 			bond_info->rx_ntt = 1;
574 		}
575 	}
576 
577 	spin_unlock(&bond->mode_lock);
578 }
579 
580 static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bond)
581 {
582 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
583 	struct arp_pkt *arp = arp_pkt(skb);
584 	struct slave *assigned_slave, *curr_active_slave;
585 	struct rlb_client_info *client_info;
586 	u32 hash_index = 0;
587 
588 	spin_lock(&bond->mode_lock);
589 
590 	curr_active_slave = rcu_dereference(bond->curr_active_slave);
591 
592 	hash_index = _simple_hash((u8 *)&arp->ip_dst, sizeof(arp->ip_dst));
593 	client_info = &(bond_info->rx_hashtbl[hash_index]);
594 
595 	if (client_info->assigned) {
596 		if ((client_info->ip_src == arp->ip_src) &&
597 		    (client_info->ip_dst == arp->ip_dst)) {
598 			/* the entry is already assigned to this client */
599 			if (!ether_addr_equal_64bits(arp->mac_dst, mac_bcast)) {
600 				/* update mac address from arp */
601 				ether_addr_copy(client_info->mac_dst, arp->mac_dst);
602 			}
603 			ether_addr_copy(client_info->mac_src, arp->mac_src);
604 
605 			assigned_slave = client_info->slave;
606 			if (assigned_slave) {
607 				spin_unlock(&bond->mode_lock);
608 				return assigned_slave;
609 			}
610 		} else {
611 			/* the entry is already assigned to some other client,
612 			 * move the old client to primary (curr_active_slave) so
613 			 * that the new client can be assigned to this entry.
614 			 */
615 			if (curr_active_slave &&
616 			    client_info->slave != curr_active_slave) {
617 				client_info->slave = curr_active_slave;
618 				rlb_update_client(client_info);
619 			}
620 		}
621 	}
622 	/* assign a new slave */
623 	assigned_slave = __rlb_next_rx_slave(bond);
624 
625 	if (assigned_slave) {
626 		if (!(client_info->assigned &&
627 		      client_info->ip_src == arp->ip_src)) {
628 			/* ip_src is going to be updated,
629 			 * fix the src hash list
630 			 */
631 			u32 hash_src = _simple_hash((u8 *)&arp->ip_src,
632 						    sizeof(arp->ip_src));
633 			rlb_src_unlink(bond, hash_index);
634 			rlb_src_link(bond, hash_src, hash_index);
635 		}
636 
637 		client_info->ip_src = arp->ip_src;
638 		client_info->ip_dst = arp->ip_dst;
639 		/* arp->mac_dst is broadcast for arp reqeusts.
640 		 * will be updated with clients actual unicast mac address
641 		 * upon receiving an arp reply.
642 		 */
643 		ether_addr_copy(client_info->mac_dst, arp->mac_dst);
644 		ether_addr_copy(client_info->mac_src, arp->mac_src);
645 		client_info->slave = assigned_slave;
646 
647 		if (!ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
648 			client_info->ntt = 1;
649 			bond->alb_info.rx_ntt = 1;
650 		} else {
651 			client_info->ntt = 0;
652 		}
653 
654 		if (vlan_get_tag(skb, &client_info->vlan_id))
655 			client_info->vlan_id = 0;
656 
657 		if (!client_info->assigned) {
658 			u32 prev_tbl_head = bond_info->rx_hashtbl_used_head;
659 			bond_info->rx_hashtbl_used_head = hash_index;
660 			client_info->used_next = prev_tbl_head;
661 			if (prev_tbl_head != RLB_NULL_INDEX) {
662 				bond_info->rx_hashtbl[prev_tbl_head].used_prev =
663 					hash_index;
664 			}
665 			client_info->assigned = 1;
666 		}
667 	}
668 
669 	spin_unlock(&bond->mode_lock);
670 
671 	return assigned_slave;
672 }
673 
674 /* chooses (and returns) transmit channel for arp reply
675  * does not choose channel for other arp types since they are
676  * sent on the curr_active_slave
677  */
678 static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
679 {
680 	struct arp_pkt *arp = arp_pkt(skb);
681 	struct slave *tx_slave = NULL;
682 
683 	/* Don't modify or load balance ARPs that do not originate locally
684 	 * (e.g.,arrive via a bridge).
685 	 */
686 	if (!bond_slave_has_mac_rx(bond, arp->mac_src))
687 		return NULL;
688 
689 	if (arp->op_code == htons(ARPOP_REPLY)) {
690 		/* the arp must be sent on the selected rx channel */
691 		tx_slave = rlb_choose_channel(skb, bond);
692 		if (tx_slave)
693 			ether_addr_copy(arp->mac_src, tx_slave->dev->dev_addr);
694 		netdev_dbg(bond->dev, "Server sent ARP Reply packet\n");
695 	} else if (arp->op_code == htons(ARPOP_REQUEST)) {
696 		/* Create an entry in the rx_hashtbl for this client as a
697 		 * place holder.
698 		 * When the arp reply is received the entry will be updated
699 		 * with the correct unicast address of the client.
700 		 */
701 		rlb_choose_channel(skb, bond);
702 
703 		/* The ARP reply packets must be delayed so that
704 		 * they can cancel out the influence of the ARP request.
705 		 */
706 		bond->alb_info.rlb_update_delay_counter = RLB_UPDATE_DELAY;
707 
708 		/* arp requests are broadcast and are sent on the primary
709 		 * the arp request will collapse all clients on the subnet to
710 		 * the primary slave. We must register these clients to be
711 		 * updated with their assigned mac.
712 		 */
713 		rlb_req_update_subnet_clients(bond, arp->ip_src);
714 		netdev_dbg(bond->dev, "Server sent ARP Request packet\n");
715 	}
716 
717 	return tx_slave;
718 }
719 
720 static void rlb_rebalance(struct bonding *bond)
721 {
722 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
723 	struct slave *assigned_slave;
724 	struct rlb_client_info *client_info;
725 	int ntt;
726 	u32 hash_index;
727 
728 	spin_lock_bh(&bond->mode_lock);
729 
730 	ntt = 0;
731 	hash_index = bond_info->rx_hashtbl_used_head;
732 	for (; hash_index != RLB_NULL_INDEX;
733 	     hash_index = client_info->used_next) {
734 		client_info = &(bond_info->rx_hashtbl[hash_index]);
735 		assigned_slave = __rlb_next_rx_slave(bond);
736 		if (assigned_slave && (client_info->slave != assigned_slave)) {
737 			client_info->slave = assigned_slave;
738 			client_info->ntt = 1;
739 			ntt = 1;
740 		}
741 	}
742 
743 	/* update the team's flag only after the whole iteration */
744 	if (ntt)
745 		bond_info->rx_ntt = 1;
746 	spin_unlock_bh(&bond->mode_lock);
747 }
748 
749 /* Caller must hold mode_lock */
750 static void rlb_init_table_entry_dst(struct rlb_client_info *entry)
751 {
752 	entry->used_next = RLB_NULL_INDEX;
753 	entry->used_prev = RLB_NULL_INDEX;
754 	entry->assigned = 0;
755 	entry->slave = NULL;
756 	entry->vlan_id = 0;
757 }
758 static void rlb_init_table_entry_src(struct rlb_client_info *entry)
759 {
760 	entry->src_first = RLB_NULL_INDEX;
761 	entry->src_prev = RLB_NULL_INDEX;
762 	entry->src_next = RLB_NULL_INDEX;
763 }
764 
765 static void rlb_init_table_entry(struct rlb_client_info *entry)
766 {
767 	memset(entry, 0, sizeof(struct rlb_client_info));
768 	rlb_init_table_entry_dst(entry);
769 	rlb_init_table_entry_src(entry);
770 }
771 
772 static void rlb_delete_table_entry_dst(struct bonding *bond, u32 index)
773 {
774 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
775 	u32 next_index = bond_info->rx_hashtbl[index].used_next;
776 	u32 prev_index = bond_info->rx_hashtbl[index].used_prev;
777 
778 	if (index == bond_info->rx_hashtbl_used_head)
779 		bond_info->rx_hashtbl_used_head = next_index;
780 	if (prev_index != RLB_NULL_INDEX)
781 		bond_info->rx_hashtbl[prev_index].used_next = next_index;
782 	if (next_index != RLB_NULL_INDEX)
783 		bond_info->rx_hashtbl[next_index].used_prev = prev_index;
784 }
785 
786 /* unlink a rlb hash table entry from the src list */
787 static void rlb_src_unlink(struct bonding *bond, u32 index)
788 {
789 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
790 	u32 next_index = bond_info->rx_hashtbl[index].src_next;
791 	u32 prev_index = bond_info->rx_hashtbl[index].src_prev;
792 
793 	bond_info->rx_hashtbl[index].src_next = RLB_NULL_INDEX;
794 	bond_info->rx_hashtbl[index].src_prev = RLB_NULL_INDEX;
795 
796 	if (next_index != RLB_NULL_INDEX)
797 		bond_info->rx_hashtbl[next_index].src_prev = prev_index;
798 
799 	if (prev_index == RLB_NULL_INDEX)
800 		return;
801 
802 	/* is prev_index pointing to the head of this list? */
803 	if (bond_info->rx_hashtbl[prev_index].src_first == index)
804 		bond_info->rx_hashtbl[prev_index].src_first = next_index;
805 	else
806 		bond_info->rx_hashtbl[prev_index].src_next = next_index;
807 
808 }
809 
810 static void rlb_delete_table_entry(struct bonding *bond, u32 index)
811 {
812 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
813 	struct rlb_client_info *entry = &(bond_info->rx_hashtbl[index]);
814 
815 	rlb_delete_table_entry_dst(bond, index);
816 	rlb_init_table_entry_dst(entry);
817 
818 	rlb_src_unlink(bond, index);
819 }
820 
821 /* add the rx_hashtbl[ip_dst_hash] entry to the list
822  * of entries with identical ip_src_hash
823  */
824 static void rlb_src_link(struct bonding *bond, u32 ip_src_hash, u32 ip_dst_hash)
825 {
826 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
827 	u32 next;
828 
829 	bond_info->rx_hashtbl[ip_dst_hash].src_prev = ip_src_hash;
830 	next = bond_info->rx_hashtbl[ip_src_hash].src_first;
831 	bond_info->rx_hashtbl[ip_dst_hash].src_next = next;
832 	if (next != RLB_NULL_INDEX)
833 		bond_info->rx_hashtbl[next].src_prev = ip_dst_hash;
834 	bond_info->rx_hashtbl[ip_src_hash].src_first = ip_dst_hash;
835 }
836 
837 /* deletes all rx_hashtbl entries with arp->ip_src if their mac_src does
838  * not match arp->mac_src
839  */
840 static void rlb_purge_src_ip(struct bonding *bond, struct arp_pkt *arp)
841 {
842 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
843 	u32 ip_src_hash = _simple_hash((u8 *)&(arp->ip_src), sizeof(arp->ip_src));
844 	u32 index;
845 
846 	spin_lock_bh(&bond->mode_lock);
847 
848 	index = bond_info->rx_hashtbl[ip_src_hash].src_first;
849 	while (index != RLB_NULL_INDEX) {
850 		struct rlb_client_info *entry = &(bond_info->rx_hashtbl[index]);
851 		u32 next_index = entry->src_next;
852 		if (entry->ip_src == arp->ip_src &&
853 		    !ether_addr_equal_64bits(arp->mac_src, entry->mac_src))
854 				rlb_delete_table_entry(bond, index);
855 		index = next_index;
856 	}
857 	spin_unlock_bh(&bond->mode_lock);
858 }
859 
860 static int rlb_initialize(struct bonding *bond)
861 {
862 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
863 	struct rlb_client_info	*new_hashtbl;
864 	int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
865 	int i;
866 
867 	new_hashtbl = kmalloc(size, GFP_KERNEL);
868 	if (!new_hashtbl)
869 		return -1;
870 
871 	spin_lock_bh(&bond->mode_lock);
872 
873 	bond_info->rx_hashtbl = new_hashtbl;
874 
875 	bond_info->rx_hashtbl_used_head = RLB_NULL_INDEX;
876 
877 	for (i = 0; i < RLB_HASH_TABLE_SIZE; i++)
878 		rlb_init_table_entry(bond_info->rx_hashtbl + i);
879 
880 	spin_unlock_bh(&bond->mode_lock);
881 
882 	/* register to receive ARPs */
883 	bond->recv_probe = rlb_arp_recv;
884 
885 	return 0;
886 }
887 
888 static void rlb_deinitialize(struct bonding *bond)
889 {
890 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
891 
892 	spin_lock_bh(&bond->mode_lock);
893 
894 	kfree(bond_info->rx_hashtbl);
895 	bond_info->rx_hashtbl = NULL;
896 	bond_info->rx_hashtbl_used_head = RLB_NULL_INDEX;
897 
898 	spin_unlock_bh(&bond->mode_lock);
899 }
900 
901 static void rlb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
902 {
903 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
904 	u32 curr_index;
905 
906 	spin_lock_bh(&bond->mode_lock);
907 
908 	curr_index = bond_info->rx_hashtbl_used_head;
909 	while (curr_index != RLB_NULL_INDEX) {
910 		struct rlb_client_info *curr = &(bond_info->rx_hashtbl[curr_index]);
911 		u32 next_index = bond_info->rx_hashtbl[curr_index].used_next;
912 
913 		if (curr->vlan_id == vlan_id)
914 			rlb_delete_table_entry(bond, curr_index);
915 
916 		curr_index = next_index;
917 	}
918 
919 	spin_unlock_bh(&bond->mode_lock);
920 }
921 
922 /*********************** tlb/rlb shared functions *********************/
923 
924 static void alb_send_lp_vid(struct slave *slave, u8 mac_addr[],
925 			    __be16 vlan_proto, u16 vid)
926 {
927 	struct learning_pkt pkt;
928 	struct sk_buff *skb;
929 	int size = sizeof(struct learning_pkt);
930 	char *data;
931 
932 	memset(&pkt, 0, size);
933 	ether_addr_copy(pkt.mac_dst, mac_addr);
934 	ether_addr_copy(pkt.mac_src, mac_addr);
935 	pkt.type = cpu_to_be16(ETH_P_LOOPBACK);
936 
937 	skb = dev_alloc_skb(size);
938 	if (!skb)
939 		return;
940 
941 	data = skb_put(skb, size);
942 	memcpy(data, &pkt, size);
943 
944 	skb_reset_mac_header(skb);
945 	skb->network_header = skb->mac_header + ETH_HLEN;
946 	skb->protocol = pkt.type;
947 	skb->priority = TC_PRIO_CONTROL;
948 	skb->dev = slave->dev;
949 
950 	if (vid)
951 		__vlan_hwaccel_put_tag(skb, vlan_proto, vid);
952 
953 	dev_queue_xmit(skb);
954 }
955 
956 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[],
957 				      bool strict_match)
958 {
959 	struct bonding *bond = bond_get_bond_by_slave(slave);
960 	struct net_device *upper;
961 	struct list_head *iter;
962 	struct bond_vlan_tag *tags;
963 
964 	/* send untagged */
965 	alb_send_lp_vid(slave, mac_addr, 0, 0);
966 
967 	/* loop through all devices and see if we need to send a packet
968 	 * for that device.
969 	 */
970 	rcu_read_lock();
971 	netdev_for_each_all_upper_dev_rcu(bond->dev, upper, iter) {
972 		if (is_vlan_dev(upper) && vlan_get_encap_level(upper) == 0) {
973 			if (strict_match &&
974 			    ether_addr_equal_64bits(mac_addr,
975 						    upper->dev_addr)) {
976 				alb_send_lp_vid(slave, mac_addr,
977 						vlan_dev_vlan_proto(upper),
978 						vlan_dev_vlan_id(upper));
979 			} else if (!strict_match) {
980 				alb_send_lp_vid(slave, upper->dev_addr,
981 						vlan_dev_vlan_proto(upper),
982 						vlan_dev_vlan_id(upper));
983 			}
984 		}
985 
986 		/* If this is a macvlan device, then only send updates
987 		 * when strict_match is turned off.
988 		 */
989 		if (netif_is_macvlan(upper) && !strict_match) {
990 			tags = bond_verify_device_path(bond->dev, upper, 0);
991 			if (IS_ERR_OR_NULL(tags))
992 				BUG();
993 			alb_send_lp_vid(slave, upper->dev_addr,
994 					tags[0].vlan_proto, tags[0].vlan_id);
995 			kfree(tags);
996 		}
997 	}
998 	rcu_read_unlock();
999 }
1000 
1001 static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[])
1002 {
1003 	struct net_device *dev = slave->dev;
1004 	struct sockaddr s_addr;
1005 
1006 	if (BOND_MODE(slave->bond) == BOND_MODE_TLB) {
1007 		memcpy(dev->dev_addr, addr, dev->addr_len);
1008 		return 0;
1009 	}
1010 
1011 	/* for rlb each slave must have a unique hw mac addresses so that
1012 	 * each slave will receive packets destined to a different mac
1013 	 */
1014 	memcpy(s_addr.sa_data, addr, dev->addr_len);
1015 	s_addr.sa_family = dev->type;
1016 	if (dev_set_mac_address(dev, &s_addr)) {
1017 		netdev_err(slave->bond->dev, "dev_set_mac_address of dev %s failed! ALB mode requires that the base driver support setting the hw address also when the network device's interface is open\n",
1018 			   dev->name);
1019 		return -EOPNOTSUPP;
1020 	}
1021 	return 0;
1022 }
1023 
1024 /* Swap MAC addresses between two slaves.
1025  *
1026  * Called with RTNL held, and no other locks.
1027  */
1028 static void alb_swap_mac_addr(struct slave *slave1, struct slave *slave2)
1029 {
1030 	u8 tmp_mac_addr[ETH_ALEN];
1031 
1032 	ether_addr_copy(tmp_mac_addr, slave1->dev->dev_addr);
1033 	alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr);
1034 	alb_set_slave_mac_addr(slave2, tmp_mac_addr);
1035 
1036 }
1037 
1038 /* Send learning packets after MAC address swap.
1039  *
1040  * Called with RTNL and no other locks
1041  */
1042 static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
1043 				struct slave *slave2)
1044 {
1045 	int slaves_state_differ = (bond_slave_can_tx(slave1) != bond_slave_can_tx(slave2));
1046 	struct slave *disabled_slave = NULL;
1047 
1048 	ASSERT_RTNL();
1049 
1050 	/* fasten the change in the switch */
1051 	if (bond_slave_can_tx(slave1)) {
1052 		alb_send_learning_packets(slave1, slave1->dev->dev_addr, false);
1053 		if (bond->alb_info.rlb_enabled) {
1054 			/* inform the clients that the mac address
1055 			 * has changed
1056 			 */
1057 			rlb_req_update_slave_clients(bond, slave1);
1058 		}
1059 	} else {
1060 		disabled_slave = slave1;
1061 	}
1062 
1063 	if (bond_slave_can_tx(slave2)) {
1064 		alb_send_learning_packets(slave2, slave2->dev->dev_addr, false);
1065 		if (bond->alb_info.rlb_enabled) {
1066 			/* inform the clients that the mac address
1067 			 * has changed
1068 			 */
1069 			rlb_req_update_slave_clients(bond, slave2);
1070 		}
1071 	} else {
1072 		disabled_slave = slave2;
1073 	}
1074 
1075 	if (bond->alb_info.rlb_enabled && slaves_state_differ) {
1076 		/* A disabled slave was assigned an active mac addr */
1077 		rlb_teach_disabled_mac_on_primary(bond,
1078 						  disabled_slave->dev->dev_addr);
1079 	}
1080 }
1081 
1082 /**
1083  * alb_change_hw_addr_on_detach
1084  * @bond: bonding we're working on
1085  * @slave: the slave that was just detached
1086  *
1087  * We assume that @slave was already detached from the slave list.
1088  *
1089  * If @slave's permanent hw address is different both from its current
1090  * address and from @bond's address, then somewhere in the bond there's
1091  * a slave that has @slave's permanet address as its current address.
1092  * We'll make sure that that slave no longer uses @slave's permanent address.
1093  *
1094  * Caller must hold RTNL and no other locks
1095  */
1096 static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave)
1097 {
1098 	int perm_curr_diff;
1099 	int perm_bond_diff;
1100 	struct slave *found_slave;
1101 
1102 	perm_curr_diff = !ether_addr_equal_64bits(slave->perm_hwaddr,
1103 						  slave->dev->dev_addr);
1104 	perm_bond_diff = !ether_addr_equal_64bits(slave->perm_hwaddr,
1105 						  bond->dev->dev_addr);
1106 
1107 	if (perm_curr_diff && perm_bond_diff) {
1108 		found_slave = bond_slave_has_mac(bond, slave->perm_hwaddr);
1109 
1110 		if (found_slave) {
1111 			alb_swap_mac_addr(slave, found_slave);
1112 			alb_fasten_mac_swap(bond, slave, found_slave);
1113 		}
1114 	}
1115 }
1116 
1117 /**
1118  * alb_handle_addr_collision_on_attach
1119  * @bond: bonding we're working on
1120  * @slave: the slave that was just attached
1121  *
1122  * checks uniqueness of slave's mac address and handles the case the
1123  * new slave uses the bonds mac address.
1124  *
1125  * If the permanent hw address of @slave is @bond's hw address, we need to
1126  * find a different hw address to give @slave, that isn't in use by any other
1127  * slave in the bond. This address must be, of course, one of the permanent
1128  * addresses of the other slaves.
1129  *
1130  * We go over the slave list, and for each slave there we compare its
1131  * permanent hw address with the current address of all the other slaves.
1132  * If no match was found, then we've found a slave with a permanent address
1133  * that isn't used by any other slave in the bond, so we can assign it to
1134  * @slave.
1135  *
1136  * assumption: this function is called before @slave is attached to the
1137  *	       bond slave list.
1138  */
1139 static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
1140 {
1141 	struct slave *has_bond_addr = rcu_access_pointer(bond->curr_active_slave);
1142 	struct slave *tmp_slave1, *free_mac_slave = NULL;
1143 	struct list_head *iter;
1144 
1145 	if (!bond_has_slaves(bond)) {
1146 		/* this is the first slave */
1147 		return 0;
1148 	}
1149 
1150 	/* if slave's mac address differs from bond's mac address
1151 	 * check uniqueness of slave's mac address against the other
1152 	 * slaves in the bond.
1153 	 */
1154 	if (!ether_addr_equal_64bits(slave->perm_hwaddr, bond->dev->dev_addr)) {
1155 		if (!bond_slave_has_mac(bond, slave->dev->dev_addr))
1156 			return 0;
1157 
1158 		/* Try setting slave mac to bond address and fall-through
1159 		 * to code handling that situation below...
1160 		 */
1161 		alb_set_slave_mac_addr(slave, bond->dev->dev_addr);
1162 	}
1163 
1164 	/* The slave's address is equal to the address of the bond.
1165 	 * Search for a spare address in the bond for this slave.
1166 	 */
1167 	bond_for_each_slave(bond, tmp_slave1, iter) {
1168 		if (!bond_slave_has_mac(bond, tmp_slave1->perm_hwaddr)) {
1169 			/* no slave has tmp_slave1's perm addr
1170 			 * as its curr addr
1171 			 */
1172 			free_mac_slave = tmp_slave1;
1173 			break;
1174 		}
1175 
1176 		if (!has_bond_addr) {
1177 			if (ether_addr_equal_64bits(tmp_slave1->dev->dev_addr,
1178 						    bond->dev->dev_addr)) {
1179 
1180 				has_bond_addr = tmp_slave1;
1181 			}
1182 		}
1183 	}
1184 
1185 	if (free_mac_slave) {
1186 		alb_set_slave_mac_addr(slave, free_mac_slave->perm_hwaddr);
1187 
1188 		netdev_warn(bond->dev, "the hw address of slave %s is in use by the bond; giving it the hw address of %s\n",
1189 			    slave->dev->name, free_mac_slave->dev->name);
1190 
1191 	} else if (has_bond_addr) {
1192 		netdev_err(bond->dev, "the hw address of slave %s is in use by the bond; couldn't find a slave with a free hw address to give it (this should not have happened)\n",
1193 			   slave->dev->name);
1194 		return -EFAULT;
1195 	}
1196 
1197 	return 0;
1198 }
1199 
1200 /**
1201  * alb_set_mac_address
1202  * @bond:
1203  * @addr:
1204  *
1205  * In TLB mode all slaves are configured to the bond's hw address, but set
1206  * their dev_addr field to different addresses (based on their permanent hw
1207  * addresses).
1208  *
1209  * For each slave, this function sets the interface to the new address and then
1210  * changes its dev_addr field to its previous value.
1211  *
1212  * Unwinding assumes bond's mac address has not yet changed.
1213  */
1214 static int alb_set_mac_address(struct bonding *bond, void *addr)
1215 {
1216 	struct slave *slave, *rollback_slave;
1217 	struct list_head *iter;
1218 	struct sockaddr sa;
1219 	char tmp_addr[ETH_ALEN];
1220 	int res;
1221 
1222 	if (bond->alb_info.rlb_enabled)
1223 		return 0;
1224 
1225 	bond_for_each_slave(bond, slave, iter) {
1226 		/* save net_device's current hw address */
1227 		ether_addr_copy(tmp_addr, slave->dev->dev_addr);
1228 
1229 		res = dev_set_mac_address(slave->dev, addr);
1230 
1231 		/* restore net_device's hw address */
1232 		ether_addr_copy(slave->dev->dev_addr, tmp_addr);
1233 
1234 		if (res)
1235 			goto unwind;
1236 	}
1237 
1238 	return 0;
1239 
1240 unwind:
1241 	memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
1242 	sa.sa_family = bond->dev->type;
1243 
1244 	/* unwind from head to the slave that failed */
1245 	bond_for_each_slave(bond, rollback_slave, iter) {
1246 		if (rollback_slave == slave)
1247 			break;
1248 		ether_addr_copy(tmp_addr, rollback_slave->dev->dev_addr);
1249 		dev_set_mac_address(rollback_slave->dev, &sa);
1250 		ether_addr_copy(rollback_slave->dev->dev_addr, tmp_addr);
1251 	}
1252 
1253 	return res;
1254 }
1255 
1256 /************************ exported alb funcions ************************/
1257 
1258 int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
1259 {
1260 	int res;
1261 
1262 	res = tlb_initialize(bond);
1263 	if (res)
1264 		return res;
1265 
1266 	if (rlb_enabled) {
1267 		bond->alb_info.rlb_enabled = 1;
1268 		res = rlb_initialize(bond);
1269 		if (res) {
1270 			tlb_deinitialize(bond);
1271 			return res;
1272 		}
1273 	} else {
1274 		bond->alb_info.rlb_enabled = 0;
1275 	}
1276 
1277 	return 0;
1278 }
1279 
1280 void bond_alb_deinitialize(struct bonding *bond)
1281 {
1282 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1283 
1284 	tlb_deinitialize(bond);
1285 
1286 	if (bond_info->rlb_enabled)
1287 		rlb_deinitialize(bond);
1288 }
1289 
1290 static int bond_do_alb_xmit(struct sk_buff *skb, struct bonding *bond,
1291 			    struct slave *tx_slave)
1292 {
1293 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1294 	struct ethhdr *eth_data = eth_hdr(skb);
1295 
1296 	if (!tx_slave) {
1297 		/* unbalanced or unassigned, send through primary */
1298 		tx_slave = rcu_dereference(bond->curr_active_slave);
1299 		if (bond->params.tlb_dynamic_lb)
1300 			bond_info->unbalanced_load += skb->len;
1301 	}
1302 
1303 	if (tx_slave && bond_slave_can_tx(tx_slave)) {
1304 		if (tx_slave != rcu_access_pointer(bond->curr_active_slave)) {
1305 			ether_addr_copy(eth_data->h_source,
1306 					tx_slave->dev->dev_addr);
1307 		}
1308 
1309 		bond_dev_queue_xmit(bond, skb, tx_slave->dev);
1310 		goto out;
1311 	}
1312 
1313 	if (tx_slave && bond->params.tlb_dynamic_lb) {
1314 		spin_lock(&bond->mode_lock);
1315 		__tlb_clear_slave(bond, tx_slave, 0);
1316 		spin_unlock(&bond->mode_lock);
1317 	}
1318 
1319 	/* no suitable interface, frame not sent */
1320 	bond_tx_drop(bond->dev, skb);
1321 out:
1322 	return NETDEV_TX_OK;
1323 }
1324 
1325 int bond_tlb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
1326 {
1327 	struct bonding *bond = netdev_priv(bond_dev);
1328 	struct ethhdr *eth_data;
1329 	struct slave *tx_slave = NULL;
1330 	u32 hash_index;
1331 
1332 	skb_reset_mac_header(skb);
1333 	eth_data = eth_hdr(skb);
1334 
1335 	/* Do not TX balance any multicast or broadcast */
1336 	if (!is_multicast_ether_addr(eth_data->h_dest)) {
1337 		switch (skb->protocol) {
1338 		case htons(ETH_P_IP):
1339 		case htons(ETH_P_IPX):
1340 		    /* In case of IPX, it will falback to L2 hash */
1341 		case htons(ETH_P_IPV6):
1342 			hash_index = bond_xmit_hash(bond, skb);
1343 			if (bond->params.tlb_dynamic_lb) {
1344 				tx_slave = tlb_choose_channel(bond,
1345 							      hash_index & 0xFF,
1346 							      skb->len);
1347 			} else {
1348 				struct bond_up_slave *slaves;
1349 				unsigned int count;
1350 
1351 				slaves = rcu_dereference(bond->slave_arr);
1352 				count = slaves ? ACCESS_ONCE(slaves->count) : 0;
1353 				if (likely(count))
1354 					tx_slave = slaves->arr[hash_index %
1355 							       count];
1356 			}
1357 			break;
1358 		}
1359 	}
1360 	return bond_do_alb_xmit(skb, bond, tx_slave);
1361 }
1362 
1363 int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
1364 {
1365 	struct bonding *bond = netdev_priv(bond_dev);
1366 	struct ethhdr *eth_data;
1367 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1368 	struct slave *tx_slave = NULL;
1369 	static const __be32 ip_bcast = htonl(0xffffffff);
1370 	int hash_size = 0;
1371 	bool do_tx_balance = true;
1372 	u32 hash_index = 0;
1373 	const u8 *hash_start = NULL;
1374 	struct ipv6hdr *ip6hdr;
1375 
1376 	skb_reset_mac_header(skb);
1377 	eth_data = eth_hdr(skb);
1378 
1379 	switch (ntohs(skb->protocol)) {
1380 	case ETH_P_IP: {
1381 		const struct iphdr *iph = ip_hdr(skb);
1382 
1383 		if (ether_addr_equal_64bits(eth_data->h_dest, mac_bcast) ||
1384 		    (iph->daddr == ip_bcast) ||
1385 		    (iph->protocol == IPPROTO_IGMP)) {
1386 			do_tx_balance = false;
1387 			break;
1388 		}
1389 		hash_start = (char *)&(iph->daddr);
1390 		hash_size = sizeof(iph->daddr);
1391 	}
1392 		break;
1393 	case ETH_P_IPV6:
1394 		/* IPv6 doesn't really use broadcast mac address, but leave
1395 		 * that here just in case.
1396 		 */
1397 		if (ether_addr_equal_64bits(eth_data->h_dest, mac_bcast)) {
1398 			do_tx_balance = false;
1399 			break;
1400 		}
1401 
1402 		/* IPv6 uses all-nodes multicast as an equivalent to
1403 		 * broadcasts in IPv4.
1404 		 */
1405 		if (ether_addr_equal_64bits(eth_data->h_dest, mac_v6_allmcast)) {
1406 			do_tx_balance = false;
1407 			break;
1408 		}
1409 
1410 		/* Additianally, DAD probes should not be tx-balanced as that
1411 		 * will lead to false positives for duplicate addresses and
1412 		 * prevent address configuration from working.
1413 		 */
1414 		ip6hdr = ipv6_hdr(skb);
1415 		if (ipv6_addr_any(&ip6hdr->saddr)) {
1416 			do_tx_balance = false;
1417 			break;
1418 		}
1419 
1420 		hash_start = (char *)&(ipv6_hdr(skb)->daddr);
1421 		hash_size = sizeof(ipv6_hdr(skb)->daddr);
1422 		break;
1423 	case ETH_P_IPX:
1424 		if (ipx_hdr(skb)->ipx_checksum != IPX_NO_CHECKSUM) {
1425 			/* something is wrong with this packet */
1426 			do_tx_balance = false;
1427 			break;
1428 		}
1429 
1430 		if (ipx_hdr(skb)->ipx_type != IPX_TYPE_NCP) {
1431 			/* The only protocol worth balancing in
1432 			 * this family since it has an "ARP" like
1433 			 * mechanism
1434 			 */
1435 			do_tx_balance = false;
1436 			break;
1437 		}
1438 
1439 		hash_start = (char *)eth_data->h_dest;
1440 		hash_size = ETH_ALEN;
1441 		break;
1442 	case ETH_P_ARP:
1443 		do_tx_balance = false;
1444 		if (bond_info->rlb_enabled)
1445 			tx_slave = rlb_arp_xmit(skb, bond);
1446 		break;
1447 	default:
1448 		do_tx_balance = false;
1449 		break;
1450 	}
1451 
1452 	if (do_tx_balance) {
1453 		hash_index = _simple_hash(hash_start, hash_size);
1454 		tx_slave = tlb_choose_channel(bond, hash_index, skb->len);
1455 	}
1456 
1457 	return bond_do_alb_xmit(skb, bond, tx_slave);
1458 }
1459 
1460 void bond_alb_monitor(struct work_struct *work)
1461 {
1462 	struct bonding *bond = container_of(work, struct bonding,
1463 					    alb_work.work);
1464 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1465 	struct list_head *iter;
1466 	struct slave *slave;
1467 
1468 	if (!bond_has_slaves(bond)) {
1469 		bond_info->tx_rebalance_counter = 0;
1470 		bond_info->lp_counter = 0;
1471 		goto re_arm;
1472 	}
1473 
1474 	rcu_read_lock();
1475 
1476 	bond_info->tx_rebalance_counter++;
1477 	bond_info->lp_counter++;
1478 
1479 	/* send learning packets */
1480 	if (bond_info->lp_counter >= BOND_ALB_LP_TICKS(bond)) {
1481 		bool strict_match;
1482 
1483 		bond_for_each_slave_rcu(bond, slave, iter) {
1484 			/* If updating current_active, use all currently
1485 			 * user mac addreses (!strict_match).  Otherwise, only
1486 			 * use mac of the slave device.
1487 			 * In RLB mode, we always use strict matches.
1488 			 */
1489 			strict_match = (slave != rcu_access_pointer(bond->curr_active_slave) ||
1490 					bond_info->rlb_enabled);
1491 			alb_send_learning_packets(slave, slave->dev->dev_addr,
1492 						  strict_match);
1493 		}
1494 		bond_info->lp_counter = 0;
1495 	}
1496 
1497 	/* rebalance tx traffic */
1498 	if (bond_info->tx_rebalance_counter >= BOND_TLB_REBALANCE_TICKS) {
1499 		bond_for_each_slave_rcu(bond, slave, iter) {
1500 			tlb_clear_slave(bond, slave, 1);
1501 			if (slave == rcu_access_pointer(bond->curr_active_slave)) {
1502 				SLAVE_TLB_INFO(slave).load =
1503 					bond_info->unbalanced_load /
1504 						BOND_TLB_REBALANCE_INTERVAL;
1505 				bond_info->unbalanced_load = 0;
1506 			}
1507 		}
1508 		bond_info->tx_rebalance_counter = 0;
1509 	}
1510 
1511 	if (bond_info->rlb_enabled) {
1512 		if (bond_info->primary_is_promisc &&
1513 		    (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {
1514 
1515 			/* dev_set_promiscuity requires rtnl and
1516 			 * nothing else.  Avoid race with bond_close.
1517 			 */
1518 			rcu_read_unlock();
1519 			if (!rtnl_trylock())
1520 				goto re_arm;
1521 
1522 			bond_info->rlb_promisc_timeout_counter = 0;
1523 
1524 			/* If the primary was set to promiscuous mode
1525 			 * because a slave was disabled then
1526 			 * it can now leave promiscuous mode.
1527 			 */
1528 			dev_set_promiscuity(rtnl_dereference(bond->curr_active_slave)->dev,
1529 					    -1);
1530 			bond_info->primary_is_promisc = 0;
1531 
1532 			rtnl_unlock();
1533 			rcu_read_lock();
1534 		}
1535 
1536 		if (bond_info->rlb_rebalance) {
1537 			bond_info->rlb_rebalance = 0;
1538 			rlb_rebalance(bond);
1539 		}
1540 
1541 		/* check if clients need updating */
1542 		if (bond_info->rx_ntt) {
1543 			if (bond_info->rlb_update_delay_counter) {
1544 				--bond_info->rlb_update_delay_counter;
1545 			} else {
1546 				rlb_update_rx_clients(bond);
1547 				if (bond_info->rlb_update_retry_counter)
1548 					--bond_info->rlb_update_retry_counter;
1549 				else
1550 					bond_info->rx_ntt = 0;
1551 			}
1552 		}
1553 	}
1554 	rcu_read_unlock();
1555 re_arm:
1556 	queue_delayed_work(bond->wq, &bond->alb_work, alb_delta_in_ticks);
1557 }
1558 
1559 /* assumption: called before the slave is attached to the bond
1560  * and not locked by the bond lock
1561  */
1562 int bond_alb_init_slave(struct bonding *bond, struct slave *slave)
1563 {
1564 	int res;
1565 
1566 	res = alb_set_slave_mac_addr(slave, slave->perm_hwaddr);
1567 	if (res)
1568 		return res;
1569 
1570 	res = alb_handle_addr_collision_on_attach(bond, slave);
1571 	if (res)
1572 		return res;
1573 
1574 	tlb_init_slave(slave);
1575 
1576 	/* order a rebalance ASAP */
1577 	bond->alb_info.tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1578 
1579 	if (bond->alb_info.rlb_enabled)
1580 		bond->alb_info.rlb_rebalance = 1;
1581 
1582 	return 0;
1583 }
1584 
1585 /* Remove slave from tlb and rlb hash tables, and fix up MAC addresses
1586  * if necessary.
1587  *
1588  * Caller must hold RTNL and no other locks
1589  */
1590 void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
1591 {
1592 	if (bond_has_slaves(bond))
1593 		alb_change_hw_addr_on_detach(bond, slave);
1594 
1595 	tlb_clear_slave(bond, slave, 0);
1596 
1597 	if (bond->alb_info.rlb_enabled) {
1598 		bond->alb_info.rx_slave = NULL;
1599 		rlb_clear_slave(bond, slave);
1600 	}
1601 
1602 }
1603 
1604 void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link)
1605 {
1606 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1607 
1608 	if (link == BOND_LINK_DOWN) {
1609 		tlb_clear_slave(bond, slave, 0);
1610 		if (bond->alb_info.rlb_enabled)
1611 			rlb_clear_slave(bond, slave);
1612 	} else if (link == BOND_LINK_UP) {
1613 		/* order a rebalance ASAP */
1614 		bond_info->tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1615 		if (bond->alb_info.rlb_enabled) {
1616 			bond->alb_info.rlb_rebalance = 1;
1617 			/* If the updelay module parameter is smaller than the
1618 			 * forwarding delay of the switch the rebalance will
1619 			 * not work because the rebalance arp replies will
1620 			 * not be forwarded to the clients..
1621 			 */
1622 		}
1623 	}
1624 
1625 	if (bond_is_nondyn_tlb(bond)) {
1626 		if (bond_update_slave_arr(bond, NULL))
1627 			pr_err("Failed to build slave-array for TLB mode.\n");
1628 	}
1629 }
1630 
1631 /**
1632  * bond_alb_handle_active_change - assign new curr_active_slave
1633  * @bond: our bonding struct
1634  * @new_slave: new slave to assign
1635  *
1636  * Set the bond->curr_active_slave to @new_slave and handle
1637  * mac address swapping and promiscuity changes as needed.
1638  *
1639  * Caller must hold RTNL
1640  */
1641 void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
1642 {
1643 	struct slave *swap_slave;
1644 	struct slave *curr_active;
1645 
1646 	curr_active = rtnl_dereference(bond->curr_active_slave);
1647 	if (curr_active == new_slave)
1648 		return;
1649 
1650 	if (curr_active && bond->alb_info.primary_is_promisc) {
1651 		dev_set_promiscuity(curr_active->dev, -1);
1652 		bond->alb_info.primary_is_promisc = 0;
1653 		bond->alb_info.rlb_promisc_timeout_counter = 0;
1654 	}
1655 
1656 	swap_slave = curr_active;
1657 	rcu_assign_pointer(bond->curr_active_slave, new_slave);
1658 
1659 	if (!new_slave || !bond_has_slaves(bond))
1660 		return;
1661 
1662 	/* set the new curr_active_slave to the bonds mac address
1663 	 * i.e. swap mac addresses of old curr_active_slave and new curr_active_slave
1664 	 */
1665 	if (!swap_slave)
1666 		swap_slave = bond_slave_has_mac(bond, bond->dev->dev_addr);
1667 
1668 	/* Arrange for swap_slave and new_slave to temporarily be
1669 	 * ignored so we can mess with their MAC addresses without
1670 	 * fear of interference from transmit activity.
1671 	 */
1672 	if (swap_slave)
1673 		tlb_clear_slave(bond, swap_slave, 1);
1674 	tlb_clear_slave(bond, new_slave, 1);
1675 
1676 	/* in TLB mode, the slave might flip down/up with the old dev_addr,
1677 	 * and thus filter bond->dev_addr's packets, so force bond's mac
1678 	 */
1679 	if (BOND_MODE(bond) == BOND_MODE_TLB) {
1680 		struct sockaddr sa;
1681 		u8 tmp_addr[ETH_ALEN];
1682 
1683 		ether_addr_copy(tmp_addr, new_slave->dev->dev_addr);
1684 
1685 		memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
1686 		sa.sa_family = bond->dev->type;
1687 		/* we don't care if it can't change its mac, best effort */
1688 		dev_set_mac_address(new_slave->dev, &sa);
1689 
1690 		ether_addr_copy(new_slave->dev->dev_addr, tmp_addr);
1691 	}
1692 
1693 	/* curr_active_slave must be set before calling alb_swap_mac_addr */
1694 	if (swap_slave) {
1695 		/* swap mac address */
1696 		alb_swap_mac_addr(swap_slave, new_slave);
1697 		alb_fasten_mac_swap(bond, swap_slave, new_slave);
1698 	} else {
1699 		/* set the new_slave to the bond mac address */
1700 		alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr);
1701 		alb_send_learning_packets(new_slave, bond->dev->dev_addr,
1702 					  false);
1703 	}
1704 }
1705 
1706 /* Called with RTNL */
1707 int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
1708 {
1709 	struct bonding *bond = netdev_priv(bond_dev);
1710 	struct sockaddr *sa = addr;
1711 	struct slave *curr_active;
1712 	struct slave *swap_slave;
1713 	int res;
1714 
1715 	if (!is_valid_ether_addr(sa->sa_data))
1716 		return -EADDRNOTAVAIL;
1717 
1718 	res = alb_set_mac_address(bond, addr);
1719 	if (res)
1720 		return res;
1721 
1722 	memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);
1723 
1724 	/* If there is no curr_active_slave there is nothing else to do.
1725 	 * Otherwise we'll need to pass the new address to it and handle
1726 	 * duplications.
1727 	 */
1728 	curr_active = rtnl_dereference(bond->curr_active_slave);
1729 	if (!curr_active)
1730 		return 0;
1731 
1732 	swap_slave = bond_slave_has_mac(bond, bond_dev->dev_addr);
1733 
1734 	if (swap_slave) {
1735 		alb_swap_mac_addr(swap_slave, curr_active);
1736 		alb_fasten_mac_swap(bond, swap_slave, curr_active);
1737 	} else {
1738 		alb_set_slave_mac_addr(curr_active, bond_dev->dev_addr);
1739 
1740 		alb_send_learning_packets(curr_active,
1741 					  bond_dev->dev_addr, false);
1742 		if (bond->alb_info.rlb_enabled) {
1743 			/* inform clients mac address has changed */
1744 			rlb_req_update_slave_clients(bond, curr_active);
1745 		}
1746 	}
1747 
1748 	return 0;
1749 }
1750 
1751 void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
1752 {
1753 	if (bond->alb_info.rlb_enabled)
1754 		rlb_clear_vlan(bond, vlan_id);
1755 }
1756 
1757