xref: /openbmc/linux/drivers/net/bonding/bond_alb.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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, write to the Free Software Foundation, Inc.,
16  * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17  *
18  * The full GNU General Public License is included in this distribution in the
19  * file called LICENSE.
20  *
21  */
22 
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 
25 #include <linux/skbuff.h>
26 #include <linux/netdevice.h>
27 #include <linux/etherdevice.h>
28 #include <linux/pkt_sched.h>
29 #include <linux/spinlock.h>
30 #include <linux/slab.h>
31 #include <linux/timer.h>
32 #include <linux/ip.h>
33 #include <linux/ipv6.h>
34 #include <linux/if_arp.h>
35 #include <linux/if_ether.h>
36 #include <linux/if_bonding.h>
37 #include <linux/if_vlan.h>
38 #include <linux/in.h>
39 #include <net/ipx.h>
40 #include <net/arp.h>
41 #include <net/ipv6.h>
42 #include <asm/byteorder.h>
43 #include "bonding.h"
44 #include "bond_alb.h"
45 
46 
47 
48 #ifndef __long_aligned
49 #define __long_aligned __attribute__((aligned((sizeof(long)))))
50 #endif
51 static const u8 mac_bcast[ETH_ALEN] __long_aligned = {
52 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff
53 };
54 static const u8 mac_v6_allmcast[ETH_ALEN] __long_aligned = {
55 	0x33, 0x33, 0x00, 0x00, 0x00, 0x01
56 };
57 static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;
58 
59 #pragma pack(1)
60 struct learning_pkt {
61 	u8 mac_dst[ETH_ALEN];
62 	u8 mac_src[ETH_ALEN];
63 	__be16 type;
64 	u8 padding[ETH_ZLEN - ETH_HLEN];
65 };
66 
67 struct arp_pkt {
68 	__be16  hw_addr_space;
69 	__be16  prot_addr_space;
70 	u8      hw_addr_len;
71 	u8      prot_addr_len;
72 	__be16  op_code;
73 	u8      mac_src[ETH_ALEN];	/* sender hardware address */
74 	__be32  ip_src;			/* sender IP address */
75 	u8      mac_dst[ETH_ALEN];	/* target hardware address */
76 	__be32  ip_dst;			/* target IP address */
77 };
78 #pragma pack()
79 
80 static inline struct arp_pkt *arp_pkt(const struct sk_buff *skb)
81 {
82 	return (struct arp_pkt *)skb_network_header(skb);
83 }
84 
85 /* Forward declaration */
86 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[]);
87 
88 static inline u8 _simple_hash(const u8 *hash_start, int hash_size)
89 {
90 	int i;
91 	u8 hash = 0;
92 
93 	for (i = 0; i < hash_size; i++) {
94 		hash ^= hash_start[i];
95 	}
96 
97 	return hash;
98 }
99 
100 /*********************** tlb specific functions ***************************/
101 
102 static inline void _lock_tx_hashtbl(struct bonding *bond)
103 {
104 	spin_lock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
105 }
106 
107 static inline void _unlock_tx_hashtbl(struct bonding *bond)
108 {
109 	spin_unlock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
110 }
111 
112 /* Caller must hold tx_hashtbl lock */
113 static inline void tlb_init_table_entry(struct tlb_client_info *entry, int save_load)
114 {
115 	if (save_load) {
116 		entry->load_history = 1 + entry->tx_bytes /
117 				      BOND_TLB_REBALANCE_INTERVAL;
118 		entry->tx_bytes = 0;
119 	}
120 
121 	entry->tx_slave = NULL;
122 	entry->next = TLB_NULL_INDEX;
123 	entry->prev = TLB_NULL_INDEX;
124 }
125 
126 static inline void tlb_init_slave(struct slave *slave)
127 {
128 	SLAVE_TLB_INFO(slave).load = 0;
129 	SLAVE_TLB_INFO(slave).head = TLB_NULL_INDEX;
130 }
131 
132 /* Caller must hold bond lock for read */
133 static void tlb_clear_slave(struct bonding *bond, struct slave *slave, int save_load)
134 {
135 	struct tlb_client_info *tx_hash_table;
136 	u32 index;
137 
138 	_lock_tx_hashtbl(bond);
139 
140 	/* clear slave from tx_hashtbl */
141 	tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl;
142 
143 	/* skip this if we've already freed the tx hash table */
144 	if (tx_hash_table) {
145 		index = SLAVE_TLB_INFO(slave).head;
146 		while (index != TLB_NULL_INDEX) {
147 			u32 next_index = tx_hash_table[index].next;
148 			tlb_init_table_entry(&tx_hash_table[index], save_load);
149 			index = next_index;
150 		}
151 	}
152 
153 	tlb_init_slave(slave);
154 
155 	_unlock_tx_hashtbl(bond);
156 }
157 
158 /* Must be called before starting the monitor timer */
159 static int tlb_initialize(struct bonding *bond)
160 {
161 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
162 	int size = TLB_HASH_TABLE_SIZE * sizeof(struct tlb_client_info);
163 	struct tlb_client_info *new_hashtbl;
164 	int i;
165 
166 	spin_lock_init(&(bond_info->tx_hashtbl_lock));
167 
168 	new_hashtbl = kzalloc(size, GFP_KERNEL);
169 	if (!new_hashtbl) {
170 		pr_err("%s: Error: Failed to allocate TLB hash table\n",
171 		       bond->dev->name);
172 		return -1;
173 	}
174 	_lock_tx_hashtbl(bond);
175 
176 	bond_info->tx_hashtbl = new_hashtbl;
177 
178 	for (i = 0; i < TLB_HASH_TABLE_SIZE; i++) {
179 		tlb_init_table_entry(&bond_info->tx_hashtbl[i], 1);
180 	}
181 
182 	_unlock_tx_hashtbl(bond);
183 
184 	return 0;
185 }
186 
187 /* Must be called only after all slaves have been released */
188 static void tlb_deinitialize(struct bonding *bond)
189 {
190 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
191 
192 	_lock_tx_hashtbl(bond);
193 
194 	kfree(bond_info->tx_hashtbl);
195 	bond_info->tx_hashtbl = NULL;
196 
197 	_unlock_tx_hashtbl(bond);
198 }
199 
200 static long long compute_gap(struct slave *slave)
201 {
202 	return (s64) (slave->speed << 20) - /* Convert to Megabit per sec */
203 	       (s64) (SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
204 }
205 
206 /* Caller must hold bond lock for read */
207 static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
208 {
209 	struct slave *slave, *least_loaded;
210 	long long max_gap;
211 	int i;
212 
213 	least_loaded = NULL;
214 	max_gap = LLONG_MIN;
215 
216 	/* Find the slave with the largest gap */
217 	bond_for_each_slave(bond, slave, i) {
218 		if (SLAVE_IS_OK(slave)) {
219 			long long gap = compute_gap(slave);
220 
221 			if (max_gap < gap) {
222 				least_loaded = slave;
223 				max_gap = gap;
224 			}
225 		}
226 	}
227 
228 	return least_loaded;
229 }
230 
231 /* Caller must hold bond lock for read */
232 static struct slave *tlb_choose_channel(struct bonding *bond, u32 hash_index, u32 skb_len)
233 {
234 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
235 	struct tlb_client_info *hash_table;
236 	struct slave *assigned_slave;
237 
238 	_lock_tx_hashtbl(bond);
239 
240 	hash_table = bond_info->tx_hashtbl;
241 	assigned_slave = hash_table[hash_index].tx_slave;
242 	if (!assigned_slave) {
243 		assigned_slave = tlb_get_least_loaded_slave(bond);
244 
245 		if (assigned_slave) {
246 			struct tlb_slave_info *slave_info =
247 				&(SLAVE_TLB_INFO(assigned_slave));
248 			u32 next_index = slave_info->head;
249 
250 			hash_table[hash_index].tx_slave = assigned_slave;
251 			hash_table[hash_index].next = next_index;
252 			hash_table[hash_index].prev = TLB_NULL_INDEX;
253 
254 			if (next_index != TLB_NULL_INDEX) {
255 				hash_table[next_index].prev = hash_index;
256 			}
257 
258 			slave_info->head = hash_index;
259 			slave_info->load +=
260 				hash_table[hash_index].load_history;
261 		}
262 	}
263 
264 	if (assigned_slave) {
265 		hash_table[hash_index].tx_bytes += skb_len;
266 	}
267 
268 	_unlock_tx_hashtbl(bond);
269 
270 	return assigned_slave;
271 }
272 
273 /*********************** rlb specific functions ***************************/
274 static inline void _lock_rx_hashtbl(struct bonding *bond)
275 {
276 	spin_lock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
277 }
278 
279 static inline void _unlock_rx_hashtbl(struct bonding *bond)
280 {
281 	spin_unlock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
282 }
283 
284 /* when an ARP REPLY is received from a client update its info
285  * in the rx_hashtbl
286  */
287 static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
288 {
289 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
290 	struct rlb_client_info *client_info;
291 	u32 hash_index;
292 
293 	_lock_rx_hashtbl(bond);
294 
295 	hash_index = _simple_hash((u8*)&(arp->ip_src), sizeof(arp->ip_src));
296 	client_info = &(bond_info->rx_hashtbl[hash_index]);
297 
298 	if ((client_info->assigned) &&
299 	    (client_info->ip_src == arp->ip_dst) &&
300 	    (client_info->ip_dst == arp->ip_src) &&
301 	    (compare_ether_addr_64bits(client_info->mac_dst, arp->mac_src))) {
302 		/* update the clients MAC address */
303 		memcpy(client_info->mac_dst, arp->mac_src, ETH_ALEN);
304 		client_info->ntt = 1;
305 		bond_info->rx_ntt = 1;
306 	}
307 
308 	_unlock_rx_hashtbl(bond);
309 }
310 
311 static int rlb_arp_recv(struct sk_buff *skb, struct net_device *bond_dev, struct packet_type *ptype, struct net_device *orig_dev)
312 {
313 	struct bonding *bond;
314 	struct arp_pkt *arp = (struct arp_pkt *)skb->data;
315 	int res = NET_RX_DROP;
316 
317 	while (bond_dev->priv_flags & IFF_802_1Q_VLAN)
318 		bond_dev = vlan_dev_real_dev(bond_dev);
319 
320 	if (!(bond_dev->priv_flags & IFF_BONDING) ||
321 	    !(bond_dev->flags & IFF_MASTER))
322 		goto out;
323 
324 	if (!arp) {
325 		pr_debug("Packet has no ARP data\n");
326 		goto out;
327 	}
328 
329 	if (!pskb_may_pull(skb, arp_hdr_len(bond_dev)))
330 		goto out;
331 
332 	if (skb->len < sizeof(struct arp_pkt)) {
333 		pr_debug("Packet is too small to be an ARP\n");
334 		goto out;
335 	}
336 
337 	if (arp->op_code == htons(ARPOP_REPLY)) {
338 		/* update rx hash table for this ARP */
339 		bond = netdev_priv(bond_dev);
340 		rlb_update_entry_from_arp(bond, arp);
341 		pr_debug("Server received an ARP Reply from client\n");
342 	}
343 
344 	res = NET_RX_SUCCESS;
345 
346 out:
347 	dev_kfree_skb(skb);
348 
349 	return res;
350 }
351 
352 /* Caller must hold bond lock for read */
353 static struct slave *rlb_next_rx_slave(struct bonding *bond)
354 {
355 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
356 	struct slave *rx_slave, *slave, *start_at;
357 	int i = 0;
358 
359 	if (bond_info->next_rx_slave) {
360 		start_at = bond_info->next_rx_slave;
361 	} else {
362 		start_at = bond->first_slave;
363 	}
364 
365 	rx_slave = NULL;
366 
367 	bond_for_each_slave_from(bond, slave, i, start_at) {
368 		if (SLAVE_IS_OK(slave)) {
369 			if (!rx_slave) {
370 				rx_slave = slave;
371 			} else if (slave->speed > rx_slave->speed) {
372 				rx_slave = slave;
373 			}
374 		}
375 	}
376 
377 	if (rx_slave) {
378 		bond_info->next_rx_slave = rx_slave->next;
379 	}
380 
381 	return rx_slave;
382 }
383 
384 /* teach the switch the mac of a disabled slave
385  * on the primary for fault tolerance
386  *
387  * Caller must hold bond->curr_slave_lock for write or bond lock for write
388  */
389 static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
390 {
391 	if (!bond->curr_active_slave) {
392 		return;
393 	}
394 
395 	if (!bond->alb_info.primary_is_promisc) {
396 		if (!dev_set_promiscuity(bond->curr_active_slave->dev, 1))
397 			bond->alb_info.primary_is_promisc = 1;
398 		else
399 			bond->alb_info.primary_is_promisc = 0;
400 	}
401 
402 	bond->alb_info.rlb_promisc_timeout_counter = 0;
403 
404 	alb_send_learning_packets(bond->curr_active_slave, addr);
405 }
406 
407 /* slave being removed should not be active at this point
408  *
409  * Caller must hold bond lock for read
410  */
411 static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
412 {
413 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
414 	struct rlb_client_info *rx_hash_table;
415 	u32 index, next_index;
416 
417 	/* clear slave from rx_hashtbl */
418 	_lock_rx_hashtbl(bond);
419 
420 	rx_hash_table = bond_info->rx_hashtbl;
421 	index = bond_info->rx_hashtbl_head;
422 	for (; index != RLB_NULL_INDEX; index = next_index) {
423 		next_index = rx_hash_table[index].next;
424 		if (rx_hash_table[index].slave == slave) {
425 			struct slave *assigned_slave = rlb_next_rx_slave(bond);
426 
427 			if (assigned_slave) {
428 				rx_hash_table[index].slave = assigned_slave;
429 				if (compare_ether_addr_64bits(rx_hash_table[index].mac_dst,
430 							      mac_bcast)) {
431 					bond_info->rx_hashtbl[index].ntt = 1;
432 					bond_info->rx_ntt = 1;
433 					/* A slave has been removed from the
434 					 * table because it is either disabled
435 					 * or being released. We must retry the
436 					 * update to avoid clients from not
437 					 * being updated & disconnecting when
438 					 * there is stress
439 					 */
440 					bond_info->rlb_update_retry_counter =
441 						RLB_UPDATE_RETRY;
442 				}
443 			} else {  /* there is no active slave */
444 				rx_hash_table[index].slave = NULL;
445 			}
446 		}
447 	}
448 
449 	_unlock_rx_hashtbl(bond);
450 
451 	write_lock_bh(&bond->curr_slave_lock);
452 
453 	if (slave != bond->curr_active_slave) {
454 		rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
455 	}
456 
457 	write_unlock_bh(&bond->curr_slave_lock);
458 }
459 
460 static void rlb_update_client(struct rlb_client_info *client_info)
461 {
462 	int i;
463 
464 	if (!client_info->slave) {
465 		return;
466 	}
467 
468 	for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
469 		struct sk_buff *skb;
470 
471 		skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
472 				 client_info->ip_dst,
473 				 client_info->slave->dev,
474 				 client_info->ip_src,
475 				 client_info->mac_dst,
476 				 client_info->slave->dev->dev_addr,
477 				 client_info->mac_dst);
478 		if (!skb) {
479 			pr_err("%s: Error: failed to create an ARP packet\n",
480 			       client_info->slave->dev->master->name);
481 			continue;
482 		}
483 
484 		skb->dev = client_info->slave->dev;
485 
486 		if (client_info->tag) {
487 			skb = vlan_put_tag(skb, client_info->vlan_id);
488 			if (!skb) {
489 				pr_err("%s: Error: failed to insert VLAN tag\n",
490 				       client_info->slave->dev->master->name);
491 				continue;
492 			}
493 		}
494 
495 		arp_xmit(skb);
496 	}
497 }
498 
499 /* sends ARP REPLIES that update the clients that need updating */
500 static void rlb_update_rx_clients(struct bonding *bond)
501 {
502 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
503 	struct rlb_client_info *client_info;
504 	u32 hash_index;
505 
506 	_lock_rx_hashtbl(bond);
507 
508 	hash_index = bond_info->rx_hashtbl_head;
509 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
510 		client_info = &(bond_info->rx_hashtbl[hash_index]);
511 		if (client_info->ntt) {
512 			rlb_update_client(client_info);
513 			if (bond_info->rlb_update_retry_counter == 0) {
514 				client_info->ntt = 0;
515 			}
516 		}
517 	}
518 
519 	/* do not update the entries again until this counter is zero so that
520 	 * not to confuse the clients.
521 	 */
522 	bond_info->rlb_update_delay_counter = RLB_UPDATE_DELAY;
523 
524 	_unlock_rx_hashtbl(bond);
525 }
526 
527 /* The slave was assigned a new mac address - update the clients */
528 static void rlb_req_update_slave_clients(struct bonding *bond, struct slave *slave)
529 {
530 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
531 	struct rlb_client_info *client_info;
532 	int ntt = 0;
533 	u32 hash_index;
534 
535 	_lock_rx_hashtbl(bond);
536 
537 	hash_index = bond_info->rx_hashtbl_head;
538 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
539 		client_info = &(bond_info->rx_hashtbl[hash_index]);
540 
541 		if ((client_info->slave == slave) &&
542 		    compare_ether_addr_64bits(client_info->mac_dst, mac_bcast)) {
543 			client_info->ntt = 1;
544 			ntt = 1;
545 		}
546 	}
547 
548 	// update the team's flag only after the whole iteration
549 	if (ntt) {
550 		bond_info->rx_ntt = 1;
551 		//fasten the change
552 		bond_info->rlb_update_retry_counter = RLB_UPDATE_RETRY;
553 	}
554 
555 	_unlock_rx_hashtbl(bond);
556 }
557 
558 /* mark all clients using src_ip to be updated */
559 static void rlb_req_update_subnet_clients(struct bonding *bond, __be32 src_ip)
560 {
561 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
562 	struct rlb_client_info *client_info;
563 	u32 hash_index;
564 
565 	_lock_rx_hashtbl(bond);
566 
567 	hash_index = bond_info->rx_hashtbl_head;
568 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
569 		client_info = &(bond_info->rx_hashtbl[hash_index]);
570 
571 		if (!client_info->slave) {
572 			pr_err("%s: Error: found a client with no channel in the client's hash table\n",
573 			       bond->dev->name);
574 			continue;
575 		}
576 		/*update all clients using this src_ip, that are not assigned
577 		 * to the team's address (curr_active_slave) and have a known
578 		 * unicast mac address.
579 		 */
580 		if ((client_info->ip_src == src_ip) &&
581 		    compare_ether_addr_64bits(client_info->slave->dev->dev_addr,
582 			   bond->dev->dev_addr) &&
583 		    compare_ether_addr_64bits(client_info->mac_dst, mac_bcast)) {
584 			client_info->ntt = 1;
585 			bond_info->rx_ntt = 1;
586 		}
587 	}
588 
589 	_unlock_rx_hashtbl(bond);
590 }
591 
592 /* Caller must hold both bond and ptr locks for read */
593 static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bond)
594 {
595 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
596 	struct arp_pkt *arp = arp_pkt(skb);
597 	struct slave *assigned_slave;
598 	struct rlb_client_info *client_info;
599 	u32 hash_index = 0;
600 
601 	_lock_rx_hashtbl(bond);
602 
603 	hash_index = _simple_hash((u8 *)&arp->ip_dst, sizeof(arp->ip_src));
604 	client_info = &(bond_info->rx_hashtbl[hash_index]);
605 
606 	if (client_info->assigned) {
607 		if ((client_info->ip_src == arp->ip_src) &&
608 		    (client_info->ip_dst == arp->ip_dst)) {
609 			/* the entry is already assigned to this client */
610 			if (compare_ether_addr_64bits(arp->mac_dst, mac_bcast)) {
611 				/* update mac address from arp */
612 				memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
613 			}
614 
615 			assigned_slave = client_info->slave;
616 			if (assigned_slave) {
617 				_unlock_rx_hashtbl(bond);
618 				return assigned_slave;
619 			}
620 		} else {
621 			/* the entry is already assigned to some other client,
622 			 * move the old client to primary (curr_active_slave) so
623 			 * that the new client can be assigned to this entry.
624 			 */
625 			if (bond->curr_active_slave &&
626 			    client_info->slave != bond->curr_active_slave) {
627 				client_info->slave = bond->curr_active_slave;
628 				rlb_update_client(client_info);
629 			}
630 		}
631 	}
632 	/* assign a new slave */
633 	assigned_slave = rlb_next_rx_slave(bond);
634 
635 	if (assigned_slave) {
636 		client_info->ip_src = arp->ip_src;
637 		client_info->ip_dst = arp->ip_dst;
638 		/* arp->mac_dst is broadcast for arp reqeusts.
639 		 * will be updated with clients actual unicast mac address
640 		 * upon receiving an arp reply.
641 		 */
642 		memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
643 		client_info->slave = assigned_slave;
644 
645 		if (compare_ether_addr_64bits(client_info->mac_dst, mac_bcast)) {
646 			client_info->ntt = 1;
647 			bond->alb_info.rx_ntt = 1;
648 		} else {
649 			client_info->ntt = 0;
650 		}
651 
652 		if (bond->vlgrp) {
653 			if (!vlan_get_tag(skb, &client_info->vlan_id))
654 				client_info->tag = 1;
655 		}
656 
657 		if (!client_info->assigned) {
658 			u32 prev_tbl_head = bond_info->rx_hashtbl_head;
659 			bond_info->rx_hashtbl_head = hash_index;
660 			client_info->next = prev_tbl_head;
661 			if (prev_tbl_head != RLB_NULL_INDEX) {
662 				bond_info->rx_hashtbl[prev_tbl_head].prev =
663 					hash_index;
664 			}
665 			client_info->assigned = 1;
666 		}
667 	}
668 
669 	_unlock_rx_hashtbl(bond);
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 	if (arp->op_code == htons(ARPOP_REPLY)) {
684 		/* the arp must be sent on the selected
685 		* rx channel
686 		*/
687 		tx_slave = rlb_choose_channel(skb, bond);
688 		if (tx_slave) {
689 			memcpy(arp->mac_src,tx_slave->dev->dev_addr, ETH_ALEN);
690 		}
691 		pr_debug("Server sent ARP Reply packet\n");
692 	} else if (arp->op_code == htons(ARPOP_REQUEST)) {
693 		/* Create an entry in the rx_hashtbl for this client as a
694 		 * place holder.
695 		 * When the arp reply is received the entry will be updated
696 		 * with the correct unicast address of the client.
697 		 */
698 		rlb_choose_channel(skb, bond);
699 
700 		/* The ARP relpy packets must be delayed so that
701 		 * they can cancel out the influence of the ARP request.
702 		 */
703 		bond->alb_info.rlb_update_delay_counter = RLB_UPDATE_DELAY;
704 
705 		/* arp requests are broadcast and are sent on the primary
706 		 * the arp request will collapse all clients on the subnet to
707 		 * the primary slave. We must register these clients to be
708 		 * updated with their assigned mac.
709 		 */
710 		rlb_req_update_subnet_clients(bond, arp->ip_src);
711 		pr_debug("Server sent ARP Request packet\n");
712 	}
713 
714 	return tx_slave;
715 }
716 
717 /* Caller must hold bond lock for read */
718 static void rlb_rebalance(struct bonding *bond)
719 {
720 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
721 	struct slave *assigned_slave;
722 	struct rlb_client_info *client_info;
723 	int ntt;
724 	u32 hash_index;
725 
726 	_lock_rx_hashtbl(bond);
727 
728 	ntt = 0;
729 	hash_index = bond_info->rx_hashtbl_head;
730 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
731 		client_info = &(bond_info->rx_hashtbl[hash_index]);
732 		assigned_slave = rlb_next_rx_slave(bond);
733 		if (assigned_slave && (client_info->slave != assigned_slave)) {
734 			client_info->slave = assigned_slave;
735 			client_info->ntt = 1;
736 			ntt = 1;
737 		}
738 	}
739 
740 	/* update the team's flag only after the whole iteration */
741 	if (ntt) {
742 		bond_info->rx_ntt = 1;
743 	}
744 	_unlock_rx_hashtbl(bond);
745 }
746 
747 /* Caller must hold rx_hashtbl lock */
748 static void rlb_init_table_entry(struct rlb_client_info *entry)
749 {
750 	memset(entry, 0, sizeof(struct rlb_client_info));
751 	entry->next = RLB_NULL_INDEX;
752 	entry->prev = RLB_NULL_INDEX;
753 }
754 
755 static int rlb_initialize(struct bonding *bond)
756 {
757 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
758 	struct packet_type *pk_type = &(BOND_ALB_INFO(bond).rlb_pkt_type);
759 	struct rlb_client_info	*new_hashtbl;
760 	int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
761 	int i;
762 
763 	spin_lock_init(&(bond_info->rx_hashtbl_lock));
764 
765 	new_hashtbl = kmalloc(size, GFP_KERNEL);
766 	if (!new_hashtbl) {
767 		pr_err("%s: Error: Failed to allocate RLB hash table\n",
768 		       bond->dev->name);
769 		return -1;
770 	}
771 	_lock_rx_hashtbl(bond);
772 
773 	bond_info->rx_hashtbl = new_hashtbl;
774 
775 	bond_info->rx_hashtbl_head = RLB_NULL_INDEX;
776 
777 	for (i = 0; i < RLB_HASH_TABLE_SIZE; i++) {
778 		rlb_init_table_entry(bond_info->rx_hashtbl + i);
779 	}
780 
781 	_unlock_rx_hashtbl(bond);
782 
783 	/*initialize packet type*/
784 	pk_type->type = cpu_to_be16(ETH_P_ARP);
785 	pk_type->dev = bond->dev;
786 	pk_type->func = rlb_arp_recv;
787 
788 	/* register to receive ARPs */
789 	dev_add_pack(pk_type);
790 
791 	return 0;
792 }
793 
794 static void rlb_deinitialize(struct bonding *bond)
795 {
796 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
797 
798 	dev_remove_pack(&(bond_info->rlb_pkt_type));
799 
800 	_lock_rx_hashtbl(bond);
801 
802 	kfree(bond_info->rx_hashtbl);
803 	bond_info->rx_hashtbl = NULL;
804 	bond_info->rx_hashtbl_head = RLB_NULL_INDEX;
805 
806 	_unlock_rx_hashtbl(bond);
807 }
808 
809 static void rlb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
810 {
811 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
812 	u32 curr_index;
813 
814 	_lock_rx_hashtbl(bond);
815 
816 	curr_index = bond_info->rx_hashtbl_head;
817 	while (curr_index != RLB_NULL_INDEX) {
818 		struct rlb_client_info *curr = &(bond_info->rx_hashtbl[curr_index]);
819 		u32 next_index = bond_info->rx_hashtbl[curr_index].next;
820 		u32 prev_index = bond_info->rx_hashtbl[curr_index].prev;
821 
822 		if (curr->tag && (curr->vlan_id == vlan_id)) {
823 			if (curr_index == bond_info->rx_hashtbl_head) {
824 				bond_info->rx_hashtbl_head = next_index;
825 			}
826 			if (prev_index != RLB_NULL_INDEX) {
827 				bond_info->rx_hashtbl[prev_index].next = next_index;
828 			}
829 			if (next_index != RLB_NULL_INDEX) {
830 				bond_info->rx_hashtbl[next_index].prev = prev_index;
831 			}
832 
833 			rlb_init_table_entry(curr);
834 		}
835 
836 		curr_index = next_index;
837 	}
838 
839 	_unlock_rx_hashtbl(bond);
840 }
841 
842 /*********************** tlb/rlb shared functions *********************/
843 
844 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
845 {
846 	struct bonding *bond = bond_get_bond_by_slave(slave);
847 	struct learning_pkt pkt;
848 	int size = sizeof(struct learning_pkt);
849 	int i;
850 
851 	memset(&pkt, 0, size);
852 	memcpy(pkt.mac_dst, mac_addr, ETH_ALEN);
853 	memcpy(pkt.mac_src, mac_addr, ETH_ALEN);
854 	pkt.type = cpu_to_be16(ETH_P_LOOP);
855 
856 	for (i = 0; i < MAX_LP_BURST; i++) {
857 		struct sk_buff *skb;
858 		char *data;
859 
860 		skb = dev_alloc_skb(size);
861 		if (!skb) {
862 			return;
863 		}
864 
865 		data = skb_put(skb, size);
866 		memcpy(data, &pkt, size);
867 
868 		skb_reset_mac_header(skb);
869 		skb->network_header = skb->mac_header + ETH_HLEN;
870 		skb->protocol = pkt.type;
871 		skb->priority = TC_PRIO_CONTROL;
872 		skb->dev = slave->dev;
873 
874 		if (bond->vlgrp) {
875 			struct vlan_entry *vlan;
876 
877 			vlan = bond_next_vlan(bond,
878 					      bond->alb_info.current_alb_vlan);
879 
880 			bond->alb_info.current_alb_vlan = vlan;
881 			if (!vlan) {
882 				kfree_skb(skb);
883 				continue;
884 			}
885 
886 			skb = vlan_put_tag(skb, vlan->vlan_id);
887 			if (!skb) {
888 				pr_err("%s: Error: failed to insert VLAN tag\n",
889 				       bond->dev->name);
890 				continue;
891 			}
892 		}
893 
894 		dev_queue_xmit(skb);
895 	}
896 }
897 
898 /* hw is a boolean parameter that determines whether we should try and
899  * set the hw address of the device as well as the hw address of the
900  * net_device
901  */
902 static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[], int hw)
903 {
904 	struct net_device *dev = slave->dev;
905 	struct sockaddr s_addr;
906 
907 	if (!hw) {
908 		memcpy(dev->dev_addr, addr, dev->addr_len);
909 		return 0;
910 	}
911 
912 	/* for rlb each slave must have a unique hw mac addresses so that */
913 	/* each slave will receive packets destined to a different mac */
914 	memcpy(s_addr.sa_data, addr, dev->addr_len);
915 	s_addr.sa_family = dev->type;
916 	if (dev_set_mac_address(dev, &s_addr)) {
917 		pr_err("%s: Error: dev_set_mac_address of dev %s failed!\n"
918 		       "ALB mode requires that the base driver support setting the hw address also when the network device's interface is open\n",
919 		       dev->master->name, dev->name);
920 		return -EOPNOTSUPP;
921 	}
922 	return 0;
923 }
924 
925 /*
926  * Swap MAC addresses between two slaves.
927  *
928  * Called with RTNL held, and no other locks.
929  *
930  */
931 
932 static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct slave *slave2)
933 {
934 	u8 tmp_mac_addr[ETH_ALEN];
935 
936 	memcpy(tmp_mac_addr, slave1->dev->dev_addr, ETH_ALEN);
937 	alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr, bond->alb_info.rlb_enabled);
938 	alb_set_slave_mac_addr(slave2, tmp_mac_addr, bond->alb_info.rlb_enabled);
939 
940 }
941 
942 /*
943  * Send learning packets after MAC address swap.
944  *
945  * Called with RTNL and no other locks
946  */
947 static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
948 				struct slave *slave2)
949 {
950 	int slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2));
951 	struct slave *disabled_slave = NULL;
952 
953 	ASSERT_RTNL();
954 
955 	/* fasten the change in the switch */
956 	if (SLAVE_IS_OK(slave1)) {
957 		alb_send_learning_packets(slave1, slave1->dev->dev_addr);
958 		if (bond->alb_info.rlb_enabled) {
959 			/* inform the clients that the mac address
960 			 * has changed
961 			 */
962 			rlb_req_update_slave_clients(bond, slave1);
963 		}
964 	} else {
965 		disabled_slave = slave1;
966 	}
967 
968 	if (SLAVE_IS_OK(slave2)) {
969 		alb_send_learning_packets(slave2, slave2->dev->dev_addr);
970 		if (bond->alb_info.rlb_enabled) {
971 			/* inform the clients that the mac address
972 			 * has changed
973 			 */
974 			rlb_req_update_slave_clients(bond, slave2);
975 		}
976 	} else {
977 		disabled_slave = slave2;
978 	}
979 
980 	if (bond->alb_info.rlb_enabled && slaves_state_differ) {
981 		/* A disabled slave was assigned an active mac addr */
982 		rlb_teach_disabled_mac_on_primary(bond,
983 						  disabled_slave->dev->dev_addr);
984 	}
985 }
986 
987 /**
988  * alb_change_hw_addr_on_detach
989  * @bond: bonding we're working on
990  * @slave: the slave that was just detached
991  *
992  * We assume that @slave was already detached from the slave list.
993  *
994  * If @slave's permanent hw address is different both from its current
995  * address and from @bond's address, then somewhere in the bond there's
996  * a slave that has @slave's permanet address as its current address.
997  * We'll make sure that that slave no longer uses @slave's permanent address.
998  *
999  * Caller must hold RTNL and no other locks
1000  */
1001 static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave)
1002 {
1003 	int perm_curr_diff;
1004 	int perm_bond_diff;
1005 
1006 	perm_curr_diff = compare_ether_addr_64bits(slave->perm_hwaddr,
1007 						   slave->dev->dev_addr);
1008 	perm_bond_diff = compare_ether_addr_64bits(slave->perm_hwaddr,
1009 						   bond->dev->dev_addr);
1010 
1011 	if (perm_curr_diff && perm_bond_diff) {
1012 		struct slave *tmp_slave;
1013 		int i, found = 0;
1014 
1015 		bond_for_each_slave(bond, tmp_slave, i) {
1016 			if (!compare_ether_addr_64bits(slave->perm_hwaddr,
1017 						       tmp_slave->dev->dev_addr)) {
1018 				found = 1;
1019 				break;
1020 			}
1021 		}
1022 
1023 		if (found) {
1024 			/* locking: needs RTNL and nothing else */
1025 			alb_swap_mac_addr(bond, slave, tmp_slave);
1026 			alb_fasten_mac_swap(bond, slave, tmp_slave);
1027 		}
1028 	}
1029 }
1030 
1031 /**
1032  * alb_handle_addr_collision_on_attach
1033  * @bond: bonding we're working on
1034  * @slave: the slave that was just attached
1035  *
1036  * checks uniqueness of slave's mac address and handles the case the
1037  * new slave uses the bonds mac address.
1038  *
1039  * If the permanent hw address of @slave is @bond's hw address, we need to
1040  * find a different hw address to give @slave, that isn't in use by any other
1041  * slave in the bond. This address must be, of course, one of the premanent
1042  * addresses of the other slaves.
1043  *
1044  * We go over the slave list, and for each slave there we compare its
1045  * permanent hw address with the current address of all the other slaves.
1046  * If no match was found, then we've found a slave with a permanent address
1047  * that isn't used by any other slave in the bond, so we can assign it to
1048  * @slave.
1049  *
1050  * assumption: this function is called before @slave is attached to the
1051  * 	       bond slave list.
1052  *
1053  * caller must hold the bond lock for write since the mac addresses are compared
1054  * and may be swapped.
1055  */
1056 static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
1057 {
1058 	struct slave *tmp_slave1, *tmp_slave2, *free_mac_slave;
1059 	struct slave *has_bond_addr = bond->curr_active_slave;
1060 	int i, j, found = 0;
1061 
1062 	if (bond->slave_cnt == 0) {
1063 		/* this is the first slave */
1064 		return 0;
1065 	}
1066 
1067 	/* if slave's mac address differs from bond's mac address
1068 	 * check uniqueness of slave's mac address against the other
1069 	 * slaves in the bond.
1070 	 */
1071 	if (compare_ether_addr_64bits(slave->perm_hwaddr, bond->dev->dev_addr)) {
1072 		bond_for_each_slave(bond, tmp_slave1, i) {
1073 			if (!compare_ether_addr_64bits(tmp_slave1->dev->dev_addr,
1074 						       slave->dev->dev_addr)) {
1075 				found = 1;
1076 				break;
1077 			}
1078 		}
1079 
1080 		if (!found)
1081 			return 0;
1082 
1083 		/* Try setting slave mac to bond address and fall-through
1084 		   to code handling that situation below... */
1085 		alb_set_slave_mac_addr(slave, bond->dev->dev_addr,
1086 				       bond->alb_info.rlb_enabled);
1087 	}
1088 
1089 	/* The slave's address is equal to the address of the bond.
1090 	 * Search for a spare address in the bond for this slave.
1091 	 */
1092 	free_mac_slave = NULL;
1093 
1094 	bond_for_each_slave(bond, tmp_slave1, i) {
1095 		found = 0;
1096 		bond_for_each_slave(bond, tmp_slave2, j) {
1097 			if (!compare_ether_addr_64bits(tmp_slave1->perm_hwaddr,
1098 						       tmp_slave2->dev->dev_addr)) {
1099 				found = 1;
1100 				break;
1101 			}
1102 		}
1103 
1104 		if (!found) {
1105 			/* no slave has tmp_slave1's perm addr
1106 			 * as its curr addr
1107 			 */
1108 			free_mac_slave = tmp_slave1;
1109 			break;
1110 		}
1111 
1112 		if (!has_bond_addr) {
1113 			if (!compare_ether_addr_64bits(tmp_slave1->dev->dev_addr,
1114 						       bond->dev->dev_addr)) {
1115 
1116 				has_bond_addr = tmp_slave1;
1117 			}
1118 		}
1119 	}
1120 
1121 	if (free_mac_slave) {
1122 		alb_set_slave_mac_addr(slave, free_mac_slave->perm_hwaddr,
1123 				       bond->alb_info.rlb_enabled);
1124 
1125 		pr_warning("%s: Warning: the hw address of slave %s is in use by the bond; giving it the hw address of %s\n",
1126 			   bond->dev->name, slave->dev->name,
1127 			   free_mac_slave->dev->name);
1128 
1129 	} else if (has_bond_addr) {
1130 		pr_err("%s: Error: 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",
1131 		       bond->dev->name, slave->dev->name);
1132 		return -EFAULT;
1133 	}
1134 
1135 	return 0;
1136 }
1137 
1138 /**
1139  * alb_set_mac_address
1140  * @bond:
1141  * @addr:
1142  *
1143  * In TLB mode all slaves are configured to the bond's hw address, but set
1144  * their dev_addr field to different addresses (based on their permanent hw
1145  * addresses).
1146  *
1147  * For each slave, this function sets the interface to the new address and then
1148  * changes its dev_addr field to its previous value.
1149  *
1150  * Unwinding assumes bond's mac address has not yet changed.
1151  */
1152 static int alb_set_mac_address(struct bonding *bond, void *addr)
1153 {
1154 	struct sockaddr sa;
1155 	struct slave *slave, *stop_at;
1156 	char tmp_addr[ETH_ALEN];
1157 	int res;
1158 	int i;
1159 
1160 	if (bond->alb_info.rlb_enabled) {
1161 		return 0;
1162 	}
1163 
1164 	bond_for_each_slave(bond, slave, i) {
1165 		/* save net_device's current hw address */
1166 		memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
1167 
1168 		res = dev_set_mac_address(slave->dev, addr);
1169 
1170 		/* restore net_device's hw address */
1171 		memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
1172 
1173 		if (res)
1174 			goto unwind;
1175 	}
1176 
1177 	return 0;
1178 
1179 unwind:
1180 	memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
1181 	sa.sa_family = bond->dev->type;
1182 
1183 	/* unwind from head to the slave that failed */
1184 	stop_at = slave;
1185 	bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at) {
1186 		memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
1187 		dev_set_mac_address(slave->dev, &sa);
1188 		memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
1189 	}
1190 
1191 	return res;
1192 }
1193 
1194 /************************ exported alb funcions ************************/
1195 
1196 int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
1197 {
1198 	int res;
1199 
1200 	res = tlb_initialize(bond);
1201 	if (res) {
1202 		return res;
1203 	}
1204 
1205 	if (rlb_enabled) {
1206 		bond->alb_info.rlb_enabled = 1;
1207 		/* initialize rlb */
1208 		res = rlb_initialize(bond);
1209 		if (res) {
1210 			tlb_deinitialize(bond);
1211 			return res;
1212 		}
1213 	} else {
1214 		bond->alb_info.rlb_enabled = 0;
1215 	}
1216 
1217 	return 0;
1218 }
1219 
1220 void bond_alb_deinitialize(struct bonding *bond)
1221 {
1222 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1223 
1224 	tlb_deinitialize(bond);
1225 
1226 	if (bond_info->rlb_enabled) {
1227 		rlb_deinitialize(bond);
1228 	}
1229 }
1230 
1231 int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
1232 {
1233 	struct bonding *bond = netdev_priv(bond_dev);
1234 	struct ethhdr *eth_data;
1235 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1236 	struct slave *tx_slave = NULL;
1237 	static const __be32 ip_bcast = htonl(0xffffffff);
1238 	int hash_size = 0;
1239 	int do_tx_balance = 1;
1240 	u32 hash_index = 0;
1241 	const u8 *hash_start = NULL;
1242 	int res = 1;
1243 	struct ipv6hdr *ip6hdr;
1244 
1245 	skb_reset_mac_header(skb);
1246 	eth_data = eth_hdr(skb);
1247 
1248 	/* make sure that the curr_active_slave and the slaves list do
1249 	 * not change during tx
1250 	 */
1251 	read_lock(&bond->lock);
1252 	read_lock(&bond->curr_slave_lock);
1253 
1254 	if (!BOND_IS_OK(bond)) {
1255 		goto out;
1256 	}
1257 
1258 	switch (ntohs(skb->protocol)) {
1259 	case ETH_P_IP: {
1260 		const struct iphdr *iph = ip_hdr(skb);
1261 
1262 		if (!compare_ether_addr_64bits(eth_data->h_dest, mac_bcast) ||
1263 		    (iph->daddr == ip_bcast) ||
1264 		    (iph->protocol == IPPROTO_IGMP)) {
1265 			do_tx_balance = 0;
1266 			break;
1267 		}
1268 		hash_start = (char *)&(iph->daddr);
1269 		hash_size = sizeof(iph->daddr);
1270 	}
1271 		break;
1272 	case ETH_P_IPV6:
1273 		/* IPv6 doesn't really use broadcast mac address, but leave
1274 		 * that here just in case.
1275 		 */
1276 		if (!compare_ether_addr_64bits(eth_data->h_dest, mac_bcast)) {
1277 			do_tx_balance = 0;
1278 			break;
1279 		}
1280 
1281 		/* IPv6 uses all-nodes multicast as an equivalent to
1282 		 * broadcasts in IPv4.
1283 		 */
1284 		if (!compare_ether_addr_64bits(eth_data->h_dest, mac_v6_allmcast)) {
1285 			do_tx_balance = 0;
1286 			break;
1287 		}
1288 
1289 		/* Additianally, DAD probes should not be tx-balanced as that
1290 		 * will lead to false positives for duplicate addresses and
1291 		 * prevent address configuration from working.
1292 		 */
1293 		ip6hdr = ipv6_hdr(skb);
1294 		if (ipv6_addr_any(&ip6hdr->saddr)) {
1295 			do_tx_balance = 0;
1296 			break;
1297 		}
1298 
1299 		hash_start = (char *)&(ipv6_hdr(skb)->daddr);
1300 		hash_size = sizeof(ipv6_hdr(skb)->daddr);
1301 		break;
1302 	case ETH_P_IPX:
1303 		if (ipx_hdr(skb)->ipx_checksum != IPX_NO_CHECKSUM) {
1304 			/* something is wrong with this packet */
1305 			do_tx_balance = 0;
1306 			break;
1307 		}
1308 
1309 		if (ipx_hdr(skb)->ipx_type != IPX_TYPE_NCP) {
1310 			/* The only protocol worth balancing in
1311 			 * this family since it has an "ARP" like
1312 			 * mechanism
1313 			 */
1314 			do_tx_balance = 0;
1315 			break;
1316 		}
1317 
1318 		hash_start = (char*)eth_data->h_dest;
1319 		hash_size = ETH_ALEN;
1320 		break;
1321 	case ETH_P_ARP:
1322 		do_tx_balance = 0;
1323 		if (bond_info->rlb_enabled) {
1324 			tx_slave = rlb_arp_xmit(skb, bond);
1325 		}
1326 		break;
1327 	default:
1328 		do_tx_balance = 0;
1329 		break;
1330 	}
1331 
1332 	if (do_tx_balance) {
1333 		hash_index = _simple_hash(hash_start, hash_size);
1334 		tx_slave = tlb_choose_channel(bond, hash_index, skb->len);
1335 	}
1336 
1337 	if (!tx_slave) {
1338 		/* unbalanced or unassigned, send through primary */
1339 		tx_slave = bond->curr_active_slave;
1340 		bond_info->unbalanced_load += skb->len;
1341 	}
1342 
1343 	if (tx_slave && SLAVE_IS_OK(tx_slave)) {
1344 		if (tx_slave != bond->curr_active_slave) {
1345 			memcpy(eth_data->h_source,
1346 			       tx_slave->dev->dev_addr,
1347 			       ETH_ALEN);
1348 		}
1349 
1350 		res = bond_dev_queue_xmit(bond, skb, tx_slave->dev);
1351 	} else {
1352 		if (tx_slave) {
1353 			tlb_clear_slave(bond, tx_slave, 0);
1354 		}
1355 	}
1356 
1357 out:
1358 	if (res) {
1359 		/* no suitable interface, frame not sent */
1360 		dev_kfree_skb(skb);
1361 	}
1362 	read_unlock(&bond->curr_slave_lock);
1363 	read_unlock(&bond->lock);
1364 	return NETDEV_TX_OK;
1365 }
1366 
1367 void bond_alb_monitor(struct work_struct *work)
1368 {
1369 	struct bonding *bond = container_of(work, struct bonding,
1370 					    alb_work.work);
1371 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1372 	struct slave *slave;
1373 	int i;
1374 
1375 	read_lock(&bond->lock);
1376 
1377 	if (bond->kill_timers) {
1378 		goto out;
1379 	}
1380 
1381 	if (bond->slave_cnt == 0) {
1382 		bond_info->tx_rebalance_counter = 0;
1383 		bond_info->lp_counter = 0;
1384 		goto re_arm;
1385 	}
1386 
1387 	bond_info->tx_rebalance_counter++;
1388 	bond_info->lp_counter++;
1389 
1390 	/* send learning packets */
1391 	if (bond_info->lp_counter >= BOND_ALB_LP_TICKS) {
1392 		/* change of curr_active_slave involves swapping of mac addresses.
1393 		 * in order to avoid this swapping from happening while
1394 		 * sending the learning packets, the curr_slave_lock must be held for
1395 		 * read.
1396 		 */
1397 		read_lock(&bond->curr_slave_lock);
1398 
1399 		bond_for_each_slave(bond, slave, i) {
1400 			alb_send_learning_packets(slave, slave->dev->dev_addr);
1401 		}
1402 
1403 		read_unlock(&bond->curr_slave_lock);
1404 
1405 		bond_info->lp_counter = 0;
1406 	}
1407 
1408 	/* rebalance tx traffic */
1409 	if (bond_info->tx_rebalance_counter >= BOND_TLB_REBALANCE_TICKS) {
1410 
1411 		read_lock(&bond->curr_slave_lock);
1412 
1413 		bond_for_each_slave(bond, slave, i) {
1414 			tlb_clear_slave(bond, slave, 1);
1415 			if (slave == bond->curr_active_slave) {
1416 				SLAVE_TLB_INFO(slave).load =
1417 					bond_info->unbalanced_load /
1418 						BOND_TLB_REBALANCE_INTERVAL;
1419 				bond_info->unbalanced_load = 0;
1420 			}
1421 		}
1422 
1423 		read_unlock(&bond->curr_slave_lock);
1424 
1425 		bond_info->tx_rebalance_counter = 0;
1426 	}
1427 
1428 	/* handle rlb stuff */
1429 	if (bond_info->rlb_enabled) {
1430 		if (bond_info->primary_is_promisc &&
1431 		    (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {
1432 
1433 			/*
1434 			 * dev_set_promiscuity requires rtnl and
1435 			 * nothing else.
1436 			 */
1437 			read_unlock(&bond->lock);
1438 			rtnl_lock();
1439 
1440 			bond_info->rlb_promisc_timeout_counter = 0;
1441 
1442 			/* If the primary was set to promiscuous mode
1443 			 * because a slave was disabled then
1444 			 * it can now leave promiscuous mode.
1445 			 */
1446 			dev_set_promiscuity(bond->curr_active_slave->dev, -1);
1447 			bond_info->primary_is_promisc = 0;
1448 
1449 			rtnl_unlock();
1450 			read_lock(&bond->lock);
1451 		}
1452 
1453 		if (bond_info->rlb_rebalance) {
1454 			bond_info->rlb_rebalance = 0;
1455 			rlb_rebalance(bond);
1456 		}
1457 
1458 		/* check if clients need updating */
1459 		if (bond_info->rx_ntt) {
1460 			if (bond_info->rlb_update_delay_counter) {
1461 				--bond_info->rlb_update_delay_counter;
1462 			} else {
1463 				rlb_update_rx_clients(bond);
1464 				if (bond_info->rlb_update_retry_counter) {
1465 					--bond_info->rlb_update_retry_counter;
1466 				} else {
1467 					bond_info->rx_ntt = 0;
1468 				}
1469 			}
1470 		}
1471 	}
1472 
1473 re_arm:
1474 	queue_delayed_work(bond->wq, &bond->alb_work, alb_delta_in_ticks);
1475 out:
1476 	read_unlock(&bond->lock);
1477 }
1478 
1479 /* assumption: called before the slave is attached to the bond
1480  * and not locked by the bond lock
1481  */
1482 int bond_alb_init_slave(struct bonding *bond, struct slave *slave)
1483 {
1484 	int res;
1485 
1486 	res = alb_set_slave_mac_addr(slave, slave->perm_hwaddr,
1487 				     bond->alb_info.rlb_enabled);
1488 	if (res) {
1489 		return res;
1490 	}
1491 
1492 	/* caller must hold the bond lock for write since the mac addresses
1493 	 * are compared and may be swapped.
1494 	 */
1495 	read_lock(&bond->lock);
1496 
1497 	res = alb_handle_addr_collision_on_attach(bond, slave);
1498 
1499 	read_unlock(&bond->lock);
1500 
1501 	if (res) {
1502 		return res;
1503 	}
1504 
1505 	tlb_init_slave(slave);
1506 
1507 	/* order a rebalance ASAP */
1508 	bond->alb_info.tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1509 
1510 	if (bond->alb_info.rlb_enabled) {
1511 		bond->alb_info.rlb_rebalance = 1;
1512 	}
1513 
1514 	return 0;
1515 }
1516 
1517 /*
1518  * Remove slave from tlb and rlb hash tables, and fix up MAC addresses
1519  * if necessary.
1520  *
1521  * Caller must hold RTNL and no other locks
1522  */
1523 void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
1524 {
1525 	if (bond->slave_cnt > 1) {
1526 		alb_change_hw_addr_on_detach(bond, slave);
1527 	}
1528 
1529 	tlb_clear_slave(bond, slave, 0);
1530 
1531 	if (bond->alb_info.rlb_enabled) {
1532 		bond->alb_info.next_rx_slave = NULL;
1533 		rlb_clear_slave(bond, slave);
1534 	}
1535 }
1536 
1537 /* Caller must hold bond lock for read */
1538 void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link)
1539 {
1540 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1541 
1542 	if (link == BOND_LINK_DOWN) {
1543 		tlb_clear_slave(bond, slave, 0);
1544 		if (bond->alb_info.rlb_enabled) {
1545 			rlb_clear_slave(bond, slave);
1546 		}
1547 	} else if (link == BOND_LINK_UP) {
1548 		/* order a rebalance ASAP */
1549 		bond_info->tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1550 		if (bond->alb_info.rlb_enabled) {
1551 			bond->alb_info.rlb_rebalance = 1;
1552 			/* If the updelay module parameter is smaller than the
1553 			 * forwarding delay of the switch the rebalance will
1554 			 * not work because the rebalance arp replies will
1555 			 * not be forwarded to the clients..
1556 			 */
1557 		}
1558 	}
1559 }
1560 
1561 /**
1562  * bond_alb_handle_active_change - assign new curr_active_slave
1563  * @bond: our bonding struct
1564  * @new_slave: new slave to assign
1565  *
1566  * Set the bond->curr_active_slave to @new_slave and handle
1567  * mac address swapping and promiscuity changes as needed.
1568  *
1569  * If new_slave is NULL, caller must hold curr_slave_lock or
1570  * bond->lock for write.
1571  *
1572  * If new_slave is not NULL, caller must hold RTNL, bond->lock for
1573  * read and curr_slave_lock for write.  Processing here may sleep, so
1574  * no other locks may be held.
1575  */
1576 void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
1577 	__releases(&bond->curr_slave_lock)
1578 	__releases(&bond->lock)
1579 	__acquires(&bond->lock)
1580 	__acquires(&bond->curr_slave_lock)
1581 {
1582 	struct slave *swap_slave;
1583 	int i;
1584 
1585 	if (bond->curr_active_slave == new_slave) {
1586 		return;
1587 	}
1588 
1589 	if (bond->curr_active_slave && bond->alb_info.primary_is_promisc) {
1590 		dev_set_promiscuity(bond->curr_active_slave->dev, -1);
1591 		bond->alb_info.primary_is_promisc = 0;
1592 		bond->alb_info.rlb_promisc_timeout_counter = 0;
1593 	}
1594 
1595 	swap_slave = bond->curr_active_slave;
1596 	bond->curr_active_slave = new_slave;
1597 
1598 	if (!new_slave || (bond->slave_cnt == 0)) {
1599 		return;
1600 	}
1601 
1602 	/* set the new curr_active_slave to the bonds mac address
1603 	 * i.e. swap mac addresses of old curr_active_slave and new curr_active_slave
1604 	 */
1605 	if (!swap_slave) {
1606 		struct slave *tmp_slave;
1607 		/* find slave that is holding the bond's mac address */
1608 		bond_for_each_slave(bond, tmp_slave, i) {
1609 			if (!compare_ether_addr_64bits(tmp_slave->dev->dev_addr,
1610 						       bond->dev->dev_addr)) {
1611 				swap_slave = tmp_slave;
1612 				break;
1613 			}
1614 		}
1615 	}
1616 
1617 	/*
1618 	 * Arrange for swap_slave and new_slave to temporarily be
1619 	 * ignored so we can mess with their MAC addresses without
1620 	 * fear of interference from transmit activity.
1621 	 */
1622 	if (swap_slave) {
1623 		tlb_clear_slave(bond, swap_slave, 1);
1624 	}
1625 	tlb_clear_slave(bond, new_slave, 1);
1626 
1627 	write_unlock_bh(&bond->curr_slave_lock);
1628 	read_unlock(&bond->lock);
1629 
1630 	ASSERT_RTNL();
1631 
1632 	/* curr_active_slave must be set before calling alb_swap_mac_addr */
1633 	if (swap_slave) {
1634 		/* swap mac address */
1635 		alb_swap_mac_addr(bond, swap_slave, new_slave);
1636 	} else {
1637 		/* set the new_slave to the bond mac address */
1638 		alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr,
1639 				       bond->alb_info.rlb_enabled);
1640 	}
1641 
1642 	if (swap_slave) {
1643 		alb_fasten_mac_swap(bond, swap_slave, new_slave);
1644 		read_lock(&bond->lock);
1645 	} else {
1646 		read_lock(&bond->lock);
1647 		alb_send_learning_packets(new_slave, bond->dev->dev_addr);
1648 	}
1649 
1650 	write_lock_bh(&bond->curr_slave_lock);
1651 }
1652 
1653 /*
1654  * Called with RTNL
1655  */
1656 int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
1657 	__acquires(&bond->lock)
1658 	__releases(&bond->lock)
1659 {
1660 	struct bonding *bond = netdev_priv(bond_dev);
1661 	struct sockaddr *sa = addr;
1662 	struct slave *slave, *swap_slave;
1663 	int res;
1664 	int i;
1665 
1666 	if (!is_valid_ether_addr(sa->sa_data)) {
1667 		return -EADDRNOTAVAIL;
1668 	}
1669 
1670 	res = alb_set_mac_address(bond, addr);
1671 	if (res) {
1672 		return res;
1673 	}
1674 
1675 	memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);
1676 
1677 	/* If there is no curr_active_slave there is nothing else to do.
1678 	 * Otherwise we'll need to pass the new address to it and handle
1679 	 * duplications.
1680 	 */
1681 	if (!bond->curr_active_slave) {
1682 		return 0;
1683 	}
1684 
1685 	swap_slave = NULL;
1686 
1687 	bond_for_each_slave(bond, slave, i) {
1688 		if (!compare_ether_addr_64bits(slave->dev->dev_addr,
1689 					       bond_dev->dev_addr)) {
1690 			swap_slave = slave;
1691 			break;
1692 		}
1693 	}
1694 
1695 	if (swap_slave) {
1696 		alb_swap_mac_addr(bond, swap_slave, bond->curr_active_slave);
1697 		alb_fasten_mac_swap(bond, swap_slave, bond->curr_active_slave);
1698 	} else {
1699 		alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr,
1700 				       bond->alb_info.rlb_enabled);
1701 
1702 		read_lock(&bond->lock);
1703 		alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
1704 		if (bond->alb_info.rlb_enabled) {
1705 			/* inform clients mac address has changed */
1706 			rlb_req_update_slave_clients(bond, bond->curr_active_slave);
1707 		}
1708 		read_unlock(&bond->lock);
1709 	}
1710 
1711 	return 0;
1712 }
1713 
1714 void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
1715 {
1716 	if (bond->alb_info.current_alb_vlan &&
1717 	    (bond->alb_info.current_alb_vlan->vlan_id == vlan_id)) {
1718 		bond->alb_info.current_alb_vlan = NULL;
1719 	}
1720 
1721 	if (bond->alb_info.rlb_enabled) {
1722 		rlb_clear_vlan(bond, vlan_id);
1723 	}
1724 }
1725 
1726