xref: /openbmc/linux/drivers/net/bonding/bond_alb.c (revision 87c2ce3b)
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 BONDING_DEBUG 1
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 <asm/byteorder.h>
42 #include "bonding.h"
43 #include "bond_alb.h"
44 
45 
46 #define ALB_TIMER_TICKS_PER_SEC	    10	/* should be a divisor of HZ */
47 #define BOND_TLB_REBALANCE_INTERVAL 10	/* In seconds, periodic re-balancing.
48 					 * Used for division - never set
49 					 * to zero !!!
50 					 */
51 #define BOND_ALB_LP_INTERVAL	    1	/* In seconds, periodic send of
52 					 * learning packets to the switch
53 					 */
54 
55 #define BOND_TLB_REBALANCE_TICKS (BOND_TLB_REBALANCE_INTERVAL \
56 				  * ALB_TIMER_TICKS_PER_SEC)
57 
58 #define BOND_ALB_LP_TICKS (BOND_ALB_LP_INTERVAL \
59 			   * ALB_TIMER_TICKS_PER_SEC)
60 
61 #define TLB_HASH_TABLE_SIZE 256	/* The size of the clients hash table.
62 				 * Note that this value MUST NOT be smaller
63 				 * because the key hash table is BYTE wide !
64 				 */
65 
66 
67 #define TLB_NULL_INDEX		0xffffffff
68 #define MAX_LP_BURST		3
69 
70 /* rlb defs */
71 #define RLB_HASH_TABLE_SIZE	256
72 #define RLB_NULL_INDEX		0xffffffff
73 #define RLB_UPDATE_DELAY	2*ALB_TIMER_TICKS_PER_SEC /* 2 seconds */
74 #define RLB_ARP_BURST_SIZE	2
75 #define RLB_UPDATE_RETRY	3	/* 3-ticks - must be smaller than the rlb
76 					 * rebalance interval (5 min).
77 					 */
78 /* RLB_PROMISC_TIMEOUT = 10 sec equals the time that the current slave is
79  * promiscuous after failover
80  */
81 #define RLB_PROMISC_TIMEOUT	10*ALB_TIMER_TICKS_PER_SEC
82 
83 static const u8 mac_bcast[ETH_ALEN] = {0xff,0xff,0xff,0xff,0xff,0xff};
84 static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;
85 
86 #pragma pack(1)
87 struct learning_pkt {
88 	u8 mac_dst[ETH_ALEN];
89 	u8 mac_src[ETH_ALEN];
90 	u16 type;
91 	u8 padding[ETH_ZLEN - ETH_HLEN];
92 };
93 
94 struct arp_pkt {
95 	u16     hw_addr_space;
96 	u16     prot_addr_space;
97 	u8      hw_addr_len;
98 	u8      prot_addr_len;
99 	u16     op_code;
100 	u8      mac_src[ETH_ALEN];	/* sender hardware address */
101 	u32     ip_src;			/* sender IP address */
102 	u8      mac_dst[ETH_ALEN];	/* target hardware address */
103 	u32     ip_dst;			/* target IP address */
104 };
105 #pragma pack()
106 
107 /* Forward declaration */
108 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[]);
109 
110 static inline u8 _simple_hash(u8 *hash_start, int hash_size)
111 {
112 	int i;
113 	u8 hash = 0;
114 
115 	for (i = 0; i < hash_size; i++) {
116 		hash ^= hash_start[i];
117 	}
118 
119 	return hash;
120 }
121 
122 /*********************** tlb specific functions ***************************/
123 
124 static inline void _lock_tx_hashtbl(struct bonding *bond)
125 {
126 	spin_lock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
127 }
128 
129 static inline void _unlock_tx_hashtbl(struct bonding *bond)
130 {
131 	spin_unlock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
132 }
133 
134 /* Caller must hold tx_hashtbl lock */
135 static inline void tlb_init_table_entry(struct tlb_client_info *entry, int save_load)
136 {
137 	if (save_load) {
138 		entry->load_history = 1 + entry->tx_bytes /
139 				      BOND_TLB_REBALANCE_INTERVAL;
140 		entry->tx_bytes = 0;
141 	}
142 
143 	entry->tx_slave = NULL;
144 	entry->next = TLB_NULL_INDEX;
145 	entry->prev = TLB_NULL_INDEX;
146 }
147 
148 static inline void tlb_init_slave(struct slave *slave)
149 {
150 	SLAVE_TLB_INFO(slave).load = 0;
151 	SLAVE_TLB_INFO(slave).head = TLB_NULL_INDEX;
152 }
153 
154 /* Caller must hold bond lock for read */
155 static void tlb_clear_slave(struct bonding *bond, struct slave *slave, int save_load)
156 {
157 	struct tlb_client_info *tx_hash_table;
158 	u32 index;
159 
160 	_lock_tx_hashtbl(bond);
161 
162 	/* clear slave from tx_hashtbl */
163 	tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl;
164 
165 	index = SLAVE_TLB_INFO(slave).head;
166 	while (index != TLB_NULL_INDEX) {
167 		u32 next_index = tx_hash_table[index].next;
168 		tlb_init_table_entry(&tx_hash_table[index], save_load);
169 		index = next_index;
170 	}
171 
172 	_unlock_tx_hashtbl(bond);
173 
174 	tlb_init_slave(slave);
175 }
176 
177 /* Must be called before starting the monitor timer */
178 static int tlb_initialize(struct bonding *bond)
179 {
180 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
181 	int size = TLB_HASH_TABLE_SIZE * sizeof(struct tlb_client_info);
182 	struct tlb_client_info *new_hashtbl;
183 	int i;
184 
185 	spin_lock_init(&(bond_info->tx_hashtbl_lock));
186 
187 	new_hashtbl = kmalloc(size, GFP_KERNEL);
188 	if (!new_hashtbl) {
189 		printk(KERN_ERR DRV_NAME
190 		       ": %s: Error: Failed to allocate TLB hash table\n",
191 		       bond->dev->name);
192 		return -1;
193 	}
194 	_lock_tx_hashtbl(bond);
195 
196 	bond_info->tx_hashtbl = new_hashtbl;
197 
198 	memset(bond_info->tx_hashtbl, 0, size);
199 
200 	for (i = 0; i < TLB_HASH_TABLE_SIZE; i++) {
201 		tlb_init_table_entry(&bond_info->tx_hashtbl[i], 1);
202 	}
203 
204 	_unlock_tx_hashtbl(bond);
205 
206 	return 0;
207 }
208 
209 /* Must be called only after all slaves have been released */
210 static void tlb_deinitialize(struct bonding *bond)
211 {
212 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
213 
214 	_lock_tx_hashtbl(bond);
215 
216 	kfree(bond_info->tx_hashtbl);
217 	bond_info->tx_hashtbl = NULL;
218 
219 	_unlock_tx_hashtbl(bond);
220 }
221 
222 /* Caller must hold bond lock for read */
223 static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
224 {
225 	struct slave *slave, *least_loaded;
226 	s64 max_gap;
227 	int i, found = 0;
228 
229 	/* Find the first enabled slave */
230 	bond_for_each_slave(bond, slave, i) {
231 		if (SLAVE_IS_OK(slave)) {
232 			found = 1;
233 			break;
234 		}
235 	}
236 
237 	if (!found) {
238 		return NULL;
239 	}
240 
241 	least_loaded = slave;
242 	max_gap = (s64)(slave->speed << 20) - /* Convert to Megabit per sec */
243 			(s64)(SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
244 
245 	/* Find the slave with the largest gap */
246 	bond_for_each_slave_from(bond, slave, i, least_loaded) {
247 		if (SLAVE_IS_OK(slave)) {
248 			s64 gap = (s64)(slave->speed << 20) -
249 					(s64)(SLAVE_TLB_INFO(slave).load << 3);
250 			if (max_gap < gap) {
251 				least_loaded = slave;
252 				max_gap = gap;
253 			}
254 		}
255 	}
256 
257 	return least_loaded;
258 }
259 
260 /* Caller must hold bond lock for read */
261 static struct slave *tlb_choose_channel(struct bonding *bond, u32 hash_index, u32 skb_len)
262 {
263 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
264 	struct tlb_client_info *hash_table;
265 	struct slave *assigned_slave;
266 
267 	_lock_tx_hashtbl(bond);
268 
269 	hash_table = bond_info->tx_hashtbl;
270 	assigned_slave = hash_table[hash_index].tx_slave;
271 	if (!assigned_slave) {
272 		assigned_slave = tlb_get_least_loaded_slave(bond);
273 
274 		if (assigned_slave) {
275 			struct tlb_slave_info *slave_info =
276 				&(SLAVE_TLB_INFO(assigned_slave));
277 			u32 next_index = slave_info->head;
278 
279 			hash_table[hash_index].tx_slave = assigned_slave;
280 			hash_table[hash_index].next = next_index;
281 			hash_table[hash_index].prev = TLB_NULL_INDEX;
282 
283 			if (next_index != TLB_NULL_INDEX) {
284 				hash_table[next_index].prev = hash_index;
285 			}
286 
287 			slave_info->head = hash_index;
288 			slave_info->load +=
289 				hash_table[hash_index].load_history;
290 		}
291 	}
292 
293 	if (assigned_slave) {
294 		hash_table[hash_index].tx_bytes += skb_len;
295 	}
296 
297 	_unlock_tx_hashtbl(bond);
298 
299 	return assigned_slave;
300 }
301 
302 /*********************** rlb specific functions ***************************/
303 static inline void _lock_rx_hashtbl(struct bonding *bond)
304 {
305 	spin_lock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
306 }
307 
308 static inline void _unlock_rx_hashtbl(struct bonding *bond)
309 {
310 	spin_unlock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
311 }
312 
313 /* when an ARP REPLY is received from a client update its info
314  * in the rx_hashtbl
315  */
316 static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
317 {
318 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
319 	struct rlb_client_info *client_info;
320 	u32 hash_index;
321 
322 	_lock_rx_hashtbl(bond);
323 
324 	hash_index = _simple_hash((u8*)&(arp->ip_src), sizeof(arp->ip_src));
325 	client_info = &(bond_info->rx_hashtbl[hash_index]);
326 
327 	if ((client_info->assigned) &&
328 	    (client_info->ip_src == arp->ip_dst) &&
329 	    (client_info->ip_dst == arp->ip_src)) {
330 		/* update the clients MAC address */
331 		memcpy(client_info->mac_dst, arp->mac_src, ETH_ALEN);
332 		client_info->ntt = 1;
333 		bond_info->rx_ntt = 1;
334 	}
335 
336 	_unlock_rx_hashtbl(bond);
337 }
338 
339 static int rlb_arp_recv(struct sk_buff *skb, struct net_device *bond_dev, struct packet_type *ptype, struct net_device *orig_dev)
340 {
341 	struct bonding *bond = bond_dev->priv;
342 	struct arp_pkt *arp = (struct arp_pkt *)skb->data;
343 	int res = NET_RX_DROP;
344 
345 	if (!(bond_dev->flags & IFF_MASTER))
346 		goto out;
347 
348 	if (!arp) {
349 		dprintk("Packet has no ARP data\n");
350 		goto out;
351 	}
352 
353 	if (skb->len < sizeof(struct arp_pkt)) {
354 		dprintk("Packet is too small to be an ARP\n");
355 		goto out;
356 	}
357 
358 	if (arp->op_code == htons(ARPOP_REPLY)) {
359 		/* update rx hash table for this ARP */
360 		rlb_update_entry_from_arp(bond, arp);
361 		dprintk("Server received an ARP Reply from client\n");
362 	}
363 
364 	res = NET_RX_SUCCESS;
365 
366 out:
367 	dev_kfree_skb(skb);
368 
369 	return res;
370 }
371 
372 /* Caller must hold bond lock for read */
373 static struct slave *rlb_next_rx_slave(struct bonding *bond)
374 {
375 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
376 	struct slave *rx_slave, *slave, *start_at;
377 	int i = 0;
378 
379 	if (bond_info->next_rx_slave) {
380 		start_at = bond_info->next_rx_slave;
381 	} else {
382 		start_at = bond->first_slave;
383 	}
384 
385 	rx_slave = NULL;
386 
387 	bond_for_each_slave_from(bond, slave, i, start_at) {
388 		if (SLAVE_IS_OK(slave)) {
389 			if (!rx_slave) {
390 				rx_slave = slave;
391 			} else if (slave->speed > rx_slave->speed) {
392 				rx_slave = slave;
393 			}
394 		}
395 	}
396 
397 	if (rx_slave) {
398 		bond_info->next_rx_slave = rx_slave->next;
399 	}
400 
401 	return rx_slave;
402 }
403 
404 /* teach the switch the mac of a disabled slave
405  * on the primary for fault tolerance
406  *
407  * Caller must hold bond->curr_slave_lock for write or bond lock for write
408  */
409 static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
410 {
411 	if (!bond->curr_active_slave) {
412 		return;
413 	}
414 
415 	if (!bond->alb_info.primary_is_promisc) {
416 		bond->alb_info.primary_is_promisc = 1;
417 		dev_set_promiscuity(bond->curr_active_slave->dev, 1);
418 	}
419 
420 	bond->alb_info.rlb_promisc_timeout_counter = 0;
421 
422 	alb_send_learning_packets(bond->curr_active_slave, addr);
423 }
424 
425 /* slave being removed should not be active at this point
426  *
427  * Caller must hold bond lock for read
428  */
429 static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
430 {
431 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
432 	struct rlb_client_info *rx_hash_table;
433 	u32 index, next_index;
434 
435 	/* clear slave from rx_hashtbl */
436 	_lock_rx_hashtbl(bond);
437 
438 	rx_hash_table = bond_info->rx_hashtbl;
439 	index = bond_info->rx_hashtbl_head;
440 	for (; index != RLB_NULL_INDEX; index = next_index) {
441 		next_index = rx_hash_table[index].next;
442 		if (rx_hash_table[index].slave == slave) {
443 			struct slave *assigned_slave = rlb_next_rx_slave(bond);
444 
445 			if (assigned_slave) {
446 				rx_hash_table[index].slave = assigned_slave;
447 				if (memcmp(rx_hash_table[index].mac_dst,
448 					   mac_bcast, ETH_ALEN)) {
449 					bond_info->rx_hashtbl[index].ntt = 1;
450 					bond_info->rx_ntt = 1;
451 					/* A slave has been removed from the
452 					 * table because it is either disabled
453 					 * or being released. We must retry the
454 					 * update to avoid clients from not
455 					 * being updated & disconnecting when
456 					 * there is stress
457 					 */
458 					bond_info->rlb_update_retry_counter =
459 						RLB_UPDATE_RETRY;
460 				}
461 			} else {  /* there is no active slave */
462 				rx_hash_table[index].slave = NULL;
463 			}
464 		}
465 	}
466 
467 	_unlock_rx_hashtbl(bond);
468 
469 	write_lock(&bond->curr_slave_lock);
470 
471 	if (slave != bond->curr_active_slave) {
472 		rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
473 	}
474 
475 	write_unlock(&bond->curr_slave_lock);
476 }
477 
478 static void rlb_update_client(struct rlb_client_info *client_info)
479 {
480 	int i;
481 
482 	if (!client_info->slave) {
483 		return;
484 	}
485 
486 	for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
487 		struct sk_buff *skb;
488 
489 		skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
490 				 client_info->ip_dst,
491 				 client_info->slave->dev,
492 				 client_info->ip_src,
493 				 client_info->mac_dst,
494 				 client_info->slave->dev->dev_addr,
495 				 client_info->mac_dst);
496 		if (!skb) {
497 			printk(KERN_ERR DRV_NAME
498 			       ": %s: Error: failed to create an ARP packet\n",
499 			       client_info->slave->dev->master->name);
500 			continue;
501 		}
502 
503 		skb->dev = client_info->slave->dev;
504 
505 		if (client_info->tag) {
506 			skb = vlan_put_tag(skb, client_info->vlan_id);
507 			if (!skb) {
508 				printk(KERN_ERR DRV_NAME
509 				       ": %s: Error: failed to insert VLAN tag\n",
510 				       client_info->slave->dev->master->name);
511 				continue;
512 			}
513 		}
514 
515 		arp_xmit(skb);
516 	}
517 }
518 
519 /* sends ARP REPLIES that update the clients that need updating */
520 static void rlb_update_rx_clients(struct bonding *bond)
521 {
522 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
523 	struct rlb_client_info *client_info;
524 	u32 hash_index;
525 
526 	_lock_rx_hashtbl(bond);
527 
528 	hash_index = bond_info->rx_hashtbl_head;
529 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
530 		client_info = &(bond_info->rx_hashtbl[hash_index]);
531 		if (client_info->ntt) {
532 			rlb_update_client(client_info);
533 			if (bond_info->rlb_update_retry_counter == 0) {
534 				client_info->ntt = 0;
535 			}
536 		}
537 	}
538 
539 	/* do not update the entries again untill this counter is zero so that
540 	 * not to confuse the clients.
541 	 */
542 	bond_info->rlb_update_delay_counter = RLB_UPDATE_DELAY;
543 
544 	_unlock_rx_hashtbl(bond);
545 }
546 
547 /* The slave was assigned a new mac address - update the clients */
548 static void rlb_req_update_slave_clients(struct bonding *bond, struct slave *slave)
549 {
550 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
551 	struct rlb_client_info *client_info;
552 	int ntt = 0;
553 	u32 hash_index;
554 
555 	_lock_rx_hashtbl(bond);
556 
557 	hash_index = bond_info->rx_hashtbl_head;
558 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
559 		client_info = &(bond_info->rx_hashtbl[hash_index]);
560 
561 		if ((client_info->slave == slave) &&
562 		    memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
563 			client_info->ntt = 1;
564 			ntt = 1;
565 		}
566 	}
567 
568 	// update the team's flag only after the whole iteration
569 	if (ntt) {
570 		bond_info->rx_ntt = 1;
571 		//fasten the change
572 		bond_info->rlb_update_retry_counter = RLB_UPDATE_RETRY;
573 	}
574 
575 	_unlock_rx_hashtbl(bond);
576 }
577 
578 /* mark all clients using src_ip to be updated */
579 static void rlb_req_update_subnet_clients(struct bonding *bond, u32 src_ip)
580 {
581 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
582 	struct rlb_client_info *client_info;
583 	u32 hash_index;
584 
585 	_lock_rx_hashtbl(bond);
586 
587 	hash_index = bond_info->rx_hashtbl_head;
588 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
589 		client_info = &(bond_info->rx_hashtbl[hash_index]);
590 
591 		if (!client_info->slave) {
592 			printk(KERN_ERR DRV_NAME
593 			       ": %s: Error: found a client with no channel in "
594 			       "the client's hash table\n",
595 			       bond->dev->name);
596 			continue;
597 		}
598 		/*update all clients using this src_ip, that are not assigned
599 		 * to the team's address (curr_active_slave) and have a known
600 		 * unicast mac address.
601 		 */
602 		if ((client_info->ip_src == src_ip) &&
603 		    memcmp(client_info->slave->dev->dev_addr,
604 			   bond->dev->dev_addr, ETH_ALEN) &&
605 		    memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
606 			client_info->ntt = 1;
607 			bond_info->rx_ntt = 1;
608 		}
609 	}
610 
611 	_unlock_rx_hashtbl(bond);
612 }
613 
614 /* Caller must hold both bond and ptr locks for read */
615 static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bond)
616 {
617 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
618 	struct arp_pkt *arp = (struct arp_pkt *)skb->nh.raw;
619 	struct slave *assigned_slave;
620 	struct rlb_client_info *client_info;
621 	u32 hash_index = 0;
622 
623 	_lock_rx_hashtbl(bond);
624 
625 	hash_index = _simple_hash((u8 *)&arp->ip_dst, sizeof(arp->ip_src));
626 	client_info = &(bond_info->rx_hashtbl[hash_index]);
627 
628 	if (client_info->assigned) {
629 		if ((client_info->ip_src == arp->ip_src) &&
630 		    (client_info->ip_dst == arp->ip_dst)) {
631 			/* the entry is already assigned to this client */
632 			if (memcmp(arp->mac_dst, mac_bcast, ETH_ALEN)) {
633 				/* update mac address from arp */
634 				memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
635 			}
636 
637 			assigned_slave = client_info->slave;
638 			if (assigned_slave) {
639 				_unlock_rx_hashtbl(bond);
640 				return assigned_slave;
641 			}
642 		} else {
643 			/* the entry is already assigned to some other client,
644 			 * move the old client to primary (curr_active_slave) so
645 			 * that the new client can be assigned to this entry.
646 			 */
647 			if (bond->curr_active_slave &&
648 			    client_info->slave != bond->curr_active_slave) {
649 				client_info->slave = bond->curr_active_slave;
650 				rlb_update_client(client_info);
651 			}
652 		}
653 	}
654 	/* assign a new slave */
655 	assigned_slave = rlb_next_rx_slave(bond);
656 
657 	if (assigned_slave) {
658 		client_info->ip_src = arp->ip_src;
659 		client_info->ip_dst = arp->ip_dst;
660 		/* arp->mac_dst is broadcast for arp reqeusts.
661 		 * will be updated with clients actual unicast mac address
662 		 * upon receiving an arp reply.
663 		 */
664 		memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
665 		client_info->slave = assigned_slave;
666 
667 		if (memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
668 			client_info->ntt = 1;
669 			bond->alb_info.rx_ntt = 1;
670 		} else {
671 			client_info->ntt = 0;
672 		}
673 
674 		if (!list_empty(&bond->vlan_list)) {
675 			unsigned short vlan_id;
676 			int res = vlan_get_tag(skb, &vlan_id);
677 			if (!res) {
678 				client_info->tag = 1;
679 				client_info->vlan_id = vlan_id;
680 			}
681 		}
682 
683 		if (!client_info->assigned) {
684 			u32 prev_tbl_head = bond_info->rx_hashtbl_head;
685 			bond_info->rx_hashtbl_head = hash_index;
686 			client_info->next = prev_tbl_head;
687 			if (prev_tbl_head != RLB_NULL_INDEX) {
688 				bond_info->rx_hashtbl[prev_tbl_head].prev =
689 					hash_index;
690 			}
691 			client_info->assigned = 1;
692 		}
693 	}
694 
695 	_unlock_rx_hashtbl(bond);
696 
697 	return assigned_slave;
698 }
699 
700 /* chooses (and returns) transmit channel for arp reply
701  * does not choose channel for other arp types since they are
702  * sent on the curr_active_slave
703  */
704 static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
705 {
706 	struct arp_pkt *arp = (struct arp_pkt *)skb->nh.raw;
707 	struct slave *tx_slave = NULL;
708 
709 	if (arp->op_code == __constant_htons(ARPOP_REPLY)) {
710 		/* the arp must be sent on the selected
711 		* rx channel
712 		*/
713 		tx_slave = rlb_choose_channel(skb, bond);
714 		if (tx_slave) {
715 			memcpy(arp->mac_src,tx_slave->dev->dev_addr, ETH_ALEN);
716 		}
717 		dprintk("Server sent ARP Reply packet\n");
718 	} else if (arp->op_code == __constant_htons(ARPOP_REQUEST)) {
719 		/* Create an entry in the rx_hashtbl for this client as a
720 		 * place holder.
721 		 * When the arp reply is received the entry will be updated
722 		 * with the correct unicast address of the client.
723 		 */
724 		rlb_choose_channel(skb, bond);
725 
726 		/* The ARP relpy packets must be delayed so that
727 		 * they can cancel out the influence of the ARP request.
728 		 */
729 		bond->alb_info.rlb_update_delay_counter = RLB_UPDATE_DELAY;
730 
731 		/* arp requests are broadcast and are sent on the primary
732 		 * the arp request will collapse all clients on the subnet to
733 		 * the primary slave. We must register these clients to be
734 		 * updated with their assigned mac.
735 		 */
736 		rlb_req_update_subnet_clients(bond, arp->ip_src);
737 		dprintk("Server sent ARP Request packet\n");
738 	}
739 
740 	return tx_slave;
741 }
742 
743 /* Caller must hold bond lock for read */
744 static void rlb_rebalance(struct bonding *bond)
745 {
746 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
747 	struct slave *assigned_slave;
748 	struct rlb_client_info *client_info;
749 	int ntt;
750 	u32 hash_index;
751 
752 	_lock_rx_hashtbl(bond);
753 
754 	ntt = 0;
755 	hash_index = bond_info->rx_hashtbl_head;
756 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
757 		client_info = &(bond_info->rx_hashtbl[hash_index]);
758 		assigned_slave = rlb_next_rx_slave(bond);
759 		if (assigned_slave && (client_info->slave != assigned_slave)) {
760 			client_info->slave = assigned_slave;
761 			client_info->ntt = 1;
762 			ntt = 1;
763 		}
764 	}
765 
766 	/* update the team's flag only after the whole iteration */
767 	if (ntt) {
768 		bond_info->rx_ntt = 1;
769 	}
770 	_unlock_rx_hashtbl(bond);
771 }
772 
773 /* Caller must hold rx_hashtbl lock */
774 static void rlb_init_table_entry(struct rlb_client_info *entry)
775 {
776 	memset(entry, 0, sizeof(struct rlb_client_info));
777 	entry->next = RLB_NULL_INDEX;
778 	entry->prev = RLB_NULL_INDEX;
779 }
780 
781 static int rlb_initialize(struct bonding *bond)
782 {
783 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
784 	struct packet_type *pk_type = &(BOND_ALB_INFO(bond).rlb_pkt_type);
785 	struct rlb_client_info	*new_hashtbl;
786 	int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
787 	int i;
788 
789 	spin_lock_init(&(bond_info->rx_hashtbl_lock));
790 
791 	new_hashtbl = kmalloc(size, GFP_KERNEL);
792 	if (!new_hashtbl) {
793 		printk(KERN_ERR DRV_NAME
794 		       ": %s: Error: Failed to allocate RLB hash table\n",
795 		       bond->dev->name);
796 		return -1;
797 	}
798 	_lock_rx_hashtbl(bond);
799 
800 	bond_info->rx_hashtbl = new_hashtbl;
801 
802 	bond_info->rx_hashtbl_head = RLB_NULL_INDEX;
803 
804 	for (i = 0; i < RLB_HASH_TABLE_SIZE; i++) {
805 		rlb_init_table_entry(bond_info->rx_hashtbl + i);
806 	}
807 
808 	_unlock_rx_hashtbl(bond);
809 
810 	/*initialize packet type*/
811 	pk_type->type = __constant_htons(ETH_P_ARP);
812 	pk_type->dev = bond->dev;
813 	pk_type->func = rlb_arp_recv;
814 
815 	/* register to receive ARPs */
816 	dev_add_pack(pk_type);
817 
818 	return 0;
819 }
820 
821 static void rlb_deinitialize(struct bonding *bond)
822 {
823 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
824 
825 	dev_remove_pack(&(bond_info->rlb_pkt_type));
826 
827 	_lock_rx_hashtbl(bond);
828 
829 	kfree(bond_info->rx_hashtbl);
830 	bond_info->rx_hashtbl = NULL;
831 	bond_info->rx_hashtbl_head = RLB_NULL_INDEX;
832 
833 	_unlock_rx_hashtbl(bond);
834 }
835 
836 static void rlb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
837 {
838 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
839 	u32 curr_index;
840 
841 	_lock_rx_hashtbl(bond);
842 
843 	curr_index = bond_info->rx_hashtbl_head;
844 	while (curr_index != RLB_NULL_INDEX) {
845 		struct rlb_client_info *curr = &(bond_info->rx_hashtbl[curr_index]);
846 		u32 next_index = bond_info->rx_hashtbl[curr_index].next;
847 		u32 prev_index = bond_info->rx_hashtbl[curr_index].prev;
848 
849 		if (curr->tag && (curr->vlan_id == vlan_id)) {
850 			if (curr_index == bond_info->rx_hashtbl_head) {
851 				bond_info->rx_hashtbl_head = next_index;
852 			}
853 			if (prev_index != RLB_NULL_INDEX) {
854 				bond_info->rx_hashtbl[prev_index].next = next_index;
855 			}
856 			if (next_index != RLB_NULL_INDEX) {
857 				bond_info->rx_hashtbl[next_index].prev = prev_index;
858 			}
859 
860 			rlb_init_table_entry(curr);
861 		}
862 
863 		curr_index = next_index;
864 	}
865 
866 	_unlock_rx_hashtbl(bond);
867 }
868 
869 /*********************** tlb/rlb shared functions *********************/
870 
871 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
872 {
873 	struct bonding *bond = bond_get_bond_by_slave(slave);
874 	struct learning_pkt pkt;
875 	int size = sizeof(struct learning_pkt);
876 	int i;
877 
878 	memset(&pkt, 0, size);
879 	memcpy(pkt.mac_dst, mac_addr, ETH_ALEN);
880 	memcpy(pkt.mac_src, mac_addr, ETH_ALEN);
881 	pkt.type = __constant_htons(ETH_P_LOOP);
882 
883 	for (i = 0; i < MAX_LP_BURST; i++) {
884 		struct sk_buff *skb;
885 		char *data;
886 
887 		skb = dev_alloc_skb(size);
888 		if (!skb) {
889 			return;
890 		}
891 
892 		data = skb_put(skb, size);
893 		memcpy(data, &pkt, size);
894 
895 		skb->mac.raw = data;
896 		skb->nh.raw = data + ETH_HLEN;
897 		skb->protocol = pkt.type;
898 		skb->priority = TC_PRIO_CONTROL;
899 		skb->dev = slave->dev;
900 
901 		if (!list_empty(&bond->vlan_list)) {
902 			struct vlan_entry *vlan;
903 
904 			vlan = bond_next_vlan(bond,
905 					      bond->alb_info.current_alb_vlan);
906 
907 			bond->alb_info.current_alb_vlan = vlan;
908 			if (!vlan) {
909 				kfree_skb(skb);
910 				continue;
911 			}
912 
913 			skb = vlan_put_tag(skb, vlan->vlan_id);
914 			if (!skb) {
915 				printk(KERN_ERR DRV_NAME
916 				       ": %s: Error: failed to insert VLAN tag\n",
917 				       bond->dev->name);
918 				continue;
919 			}
920 		}
921 
922 		dev_queue_xmit(skb);
923 	}
924 }
925 
926 /* hw is a boolean parameter that determines whether we should try and
927  * set the hw address of the device as well as the hw address of the
928  * net_device
929  */
930 static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[], int hw)
931 {
932 	struct net_device *dev = slave->dev;
933 	struct sockaddr s_addr;
934 
935 	if (!hw) {
936 		memcpy(dev->dev_addr, addr, dev->addr_len);
937 		return 0;
938 	}
939 
940 	/* for rlb each slave must have a unique hw mac addresses so that */
941 	/* each slave will receive packets destined to a different mac */
942 	memcpy(s_addr.sa_data, addr, dev->addr_len);
943 	s_addr.sa_family = dev->type;
944 	if (dev_set_mac_address(dev, &s_addr)) {
945 		printk(KERN_ERR DRV_NAME
946 		       ": %s: Error: dev_set_mac_address of dev %s failed! ALB "
947 		       "mode requires that the base driver support setting "
948 		       "the hw address also when the network device's "
949 		       "interface is open\n",
950 		       dev->master->name, dev->name);
951 		return -EOPNOTSUPP;
952 	}
953 	return 0;
954 }
955 
956 /* Caller must hold bond lock for write or curr_slave_lock for write*/
957 static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct slave *slave2)
958 {
959 	struct slave *disabled_slave = NULL;
960 	u8 tmp_mac_addr[ETH_ALEN];
961 	int slaves_state_differ;
962 
963 	slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2));
964 
965 	memcpy(tmp_mac_addr, slave1->dev->dev_addr, ETH_ALEN);
966 	alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr, bond->alb_info.rlb_enabled);
967 	alb_set_slave_mac_addr(slave2, tmp_mac_addr, bond->alb_info.rlb_enabled);
968 
969 	/* fasten the change in the switch */
970 	if (SLAVE_IS_OK(slave1)) {
971 		alb_send_learning_packets(slave1, slave1->dev->dev_addr);
972 		if (bond->alb_info.rlb_enabled) {
973 			/* inform the clients that the mac address
974 			 * has changed
975 			 */
976 			rlb_req_update_slave_clients(bond, slave1);
977 		}
978 	} else {
979 		disabled_slave = slave1;
980 	}
981 
982 	if (SLAVE_IS_OK(slave2)) {
983 		alb_send_learning_packets(slave2, slave2->dev->dev_addr);
984 		if (bond->alb_info.rlb_enabled) {
985 			/* inform the clients that the mac address
986 			 * has changed
987 			 */
988 			rlb_req_update_slave_clients(bond, slave2);
989 		}
990 	} else {
991 		disabled_slave = slave2;
992 	}
993 
994 	if (bond->alb_info.rlb_enabled && slaves_state_differ) {
995 		/* A disabled slave was assigned an active mac addr */
996 		rlb_teach_disabled_mac_on_primary(bond,
997 						  disabled_slave->dev->dev_addr);
998 	}
999 }
1000 
1001 /**
1002  * alb_change_hw_addr_on_detach
1003  * @bond: bonding we're working on
1004  * @slave: the slave that was just detached
1005  *
1006  * We assume that @slave was already detached from the slave list.
1007  *
1008  * If @slave's permanent hw address is different both from its current
1009  * address and from @bond's address, then somewhere in the bond there's
1010  * a slave that has @slave's permanet address as its current address.
1011  * We'll make sure that that slave no longer uses @slave's permanent address.
1012  *
1013  * Caller must hold bond lock
1014  */
1015 static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave)
1016 {
1017 	int perm_curr_diff;
1018 	int perm_bond_diff;
1019 
1020 	perm_curr_diff = memcmp(slave->perm_hwaddr,
1021 				slave->dev->dev_addr,
1022 				ETH_ALEN);
1023 	perm_bond_diff = memcmp(slave->perm_hwaddr,
1024 				bond->dev->dev_addr,
1025 				ETH_ALEN);
1026 
1027 	if (perm_curr_diff && perm_bond_diff) {
1028 		struct slave *tmp_slave;
1029 		int i, found = 0;
1030 
1031 		bond_for_each_slave(bond, tmp_slave, i) {
1032 			if (!memcmp(slave->perm_hwaddr,
1033 				    tmp_slave->dev->dev_addr,
1034 				    ETH_ALEN)) {
1035 				found = 1;
1036 				break;
1037 			}
1038 		}
1039 
1040 		if (found) {
1041 			alb_swap_mac_addr(bond, slave, tmp_slave);
1042 		}
1043 	}
1044 }
1045 
1046 /**
1047  * alb_handle_addr_collision_on_attach
1048  * @bond: bonding we're working on
1049  * @slave: the slave that was just attached
1050  *
1051  * checks uniqueness of slave's mac address and handles the case the
1052  * new slave uses the bonds mac address.
1053  *
1054  * If the permanent hw address of @slave is @bond's hw address, we need to
1055  * find a different hw address to give @slave, that isn't in use by any other
1056  * slave in the bond. This address must be, of course, one of the premanent
1057  * addresses of the other slaves.
1058  *
1059  * We go over the slave list, and for each slave there we compare its
1060  * permanent hw address with the current address of all the other slaves.
1061  * If no match was found, then we've found a slave with a permanent address
1062  * that isn't used by any other slave in the bond, so we can assign it to
1063  * @slave.
1064  *
1065  * assumption: this function is called before @slave is attached to the
1066  * 	       bond slave list.
1067  *
1068  * caller must hold the bond lock for write since the mac addresses are compared
1069  * and may be swapped.
1070  */
1071 static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
1072 {
1073 	struct slave *tmp_slave1, *tmp_slave2, *free_mac_slave;
1074 	struct slave *has_bond_addr = bond->curr_active_slave;
1075 	int i, j, found = 0;
1076 
1077 	if (bond->slave_cnt == 0) {
1078 		/* this is the first slave */
1079 		return 0;
1080 	}
1081 
1082 	/* if slave's mac address differs from bond's mac address
1083 	 * check uniqueness of slave's mac address against the other
1084 	 * slaves in the bond.
1085 	 */
1086 	if (memcmp(slave->perm_hwaddr, bond->dev->dev_addr, ETH_ALEN)) {
1087 		bond_for_each_slave(bond, tmp_slave1, i) {
1088 			if (!memcmp(tmp_slave1->dev->dev_addr, slave->dev->dev_addr,
1089 				    ETH_ALEN)) {
1090 				found = 1;
1091 				break;
1092 			}
1093 		}
1094 
1095 		if (!found)
1096 			return 0;
1097 
1098 		/* Try setting slave mac to bond address and fall-through
1099 		   to code handling that situation below... */
1100 		alb_set_slave_mac_addr(slave, bond->dev->dev_addr,
1101 				       bond->alb_info.rlb_enabled);
1102 	}
1103 
1104 	/* The slave's address is equal to the address of the bond.
1105 	 * Search for a spare address in the bond for this slave.
1106 	 */
1107 	free_mac_slave = NULL;
1108 
1109 	bond_for_each_slave(bond, tmp_slave1, i) {
1110 		found = 0;
1111 		bond_for_each_slave(bond, tmp_slave2, j) {
1112 			if (!memcmp(tmp_slave1->perm_hwaddr,
1113 				    tmp_slave2->dev->dev_addr,
1114 				    ETH_ALEN)) {
1115 				found = 1;
1116 				break;
1117 			}
1118 		}
1119 
1120 		if (!found) {
1121 			/* no slave has tmp_slave1's perm addr
1122 			 * as its curr addr
1123 			 */
1124 			free_mac_slave = tmp_slave1;
1125 			break;
1126 		}
1127 
1128 		if (!has_bond_addr) {
1129 			if (!memcmp(tmp_slave1->dev->dev_addr,
1130 				    bond->dev->dev_addr,
1131 				    ETH_ALEN)) {
1132 
1133 				has_bond_addr = tmp_slave1;
1134 			}
1135 		}
1136 	}
1137 
1138 	if (free_mac_slave) {
1139 		alb_set_slave_mac_addr(slave, free_mac_slave->perm_hwaddr,
1140 				       bond->alb_info.rlb_enabled);
1141 
1142 		printk(KERN_WARNING DRV_NAME
1143 		       ": %s: Warning: the hw address of slave %s is in use by "
1144 		       "the bond; giving it the hw address of %s\n",
1145 		       bond->dev->name, slave->dev->name, free_mac_slave->dev->name);
1146 
1147 	} else if (has_bond_addr) {
1148 		printk(KERN_ERR DRV_NAME
1149 		       ": %s: Error: the hw address of slave %s is in use by the "
1150 		       "bond; couldn't find a slave with a free hw address to "
1151 		       "give it (this should not have happened)\n",
1152 		       bond->dev->name, slave->dev->name);
1153 		return -EFAULT;
1154 	}
1155 
1156 	return 0;
1157 }
1158 
1159 /**
1160  * alb_set_mac_address
1161  * @bond:
1162  * @addr:
1163  *
1164  * In TLB mode all slaves are configured to the bond's hw address, but set
1165  * their dev_addr field to different addresses (based on their permanent hw
1166  * addresses).
1167  *
1168  * For each slave, this function sets the interface to the new address and then
1169  * changes its dev_addr field to its previous value.
1170  *
1171  * Unwinding assumes bond's mac address has not yet changed.
1172  */
1173 static int alb_set_mac_address(struct bonding *bond, void *addr)
1174 {
1175 	struct sockaddr sa;
1176 	struct slave *slave, *stop_at;
1177 	char tmp_addr[ETH_ALEN];
1178 	int res;
1179 	int i;
1180 
1181 	if (bond->alb_info.rlb_enabled) {
1182 		return 0;
1183 	}
1184 
1185 	bond_for_each_slave(bond, slave, i) {
1186 		if (slave->dev->set_mac_address == NULL) {
1187 			res = -EOPNOTSUPP;
1188 			goto unwind;
1189 		}
1190 
1191 		/* save net_device's current hw address */
1192 		memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
1193 
1194 		res = dev_set_mac_address(slave->dev, addr);
1195 
1196 		/* restore net_device's hw address */
1197 		memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
1198 
1199 		if (res) {
1200 			goto unwind;
1201 		}
1202 	}
1203 
1204 	return 0;
1205 
1206 unwind:
1207 	memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
1208 	sa.sa_family = bond->dev->type;
1209 
1210 	/* unwind from head to the slave that failed */
1211 	stop_at = slave;
1212 	bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at) {
1213 		memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
1214 		dev_set_mac_address(slave->dev, &sa);
1215 		memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
1216 	}
1217 
1218 	return res;
1219 }
1220 
1221 /************************ exported alb funcions ************************/
1222 
1223 int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
1224 {
1225 	int res;
1226 
1227 	res = tlb_initialize(bond);
1228 	if (res) {
1229 		return res;
1230 	}
1231 
1232 	if (rlb_enabled) {
1233 		bond->alb_info.rlb_enabled = 1;
1234 		/* initialize rlb */
1235 		res = rlb_initialize(bond);
1236 		if (res) {
1237 			tlb_deinitialize(bond);
1238 			return res;
1239 		}
1240 	} else {
1241 		bond->alb_info.rlb_enabled = 0;
1242 	}
1243 
1244 	return 0;
1245 }
1246 
1247 void bond_alb_deinitialize(struct bonding *bond)
1248 {
1249 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1250 
1251 	tlb_deinitialize(bond);
1252 
1253 	if (bond_info->rlb_enabled) {
1254 		rlb_deinitialize(bond);
1255 	}
1256 }
1257 
1258 int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
1259 {
1260 	struct bonding *bond = bond_dev->priv;
1261 	struct ethhdr *eth_data;
1262 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1263 	struct slave *tx_slave = NULL;
1264 	static u32 ip_bcast = 0xffffffff;
1265 	int hash_size = 0;
1266 	int do_tx_balance = 1;
1267 	u32 hash_index = 0;
1268 	u8 *hash_start = NULL;
1269 	int res = 1;
1270 
1271 	skb->mac.raw = (unsigned char *)skb->data;
1272 	eth_data = eth_hdr(skb);
1273 
1274 	/* make sure that the curr_active_slave and the slaves list do
1275 	 * not change during tx
1276 	 */
1277 	read_lock(&bond->lock);
1278 	read_lock(&bond->curr_slave_lock);
1279 
1280 	if (!BOND_IS_OK(bond)) {
1281 		goto out;
1282 	}
1283 
1284 	switch (ntohs(skb->protocol)) {
1285 	case ETH_P_IP:
1286 		if ((memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) ||
1287 		    (skb->nh.iph->daddr == ip_bcast) ||
1288 		    (skb->nh.iph->protocol == IPPROTO_IGMP)) {
1289 			do_tx_balance = 0;
1290 			break;
1291 		}
1292 		hash_start = (char*)&(skb->nh.iph->daddr);
1293 		hash_size = sizeof(skb->nh.iph->daddr);
1294 		break;
1295 	case ETH_P_IPV6:
1296 		if (memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) {
1297 			do_tx_balance = 0;
1298 			break;
1299 		}
1300 
1301 		hash_start = (char*)&(skb->nh.ipv6h->daddr);
1302 		hash_size = sizeof(skb->nh.ipv6h->daddr);
1303 		break;
1304 	case ETH_P_IPX:
1305 		if (ipx_hdr(skb)->ipx_checksum !=
1306 		    __constant_htons(IPX_NO_CHECKSUM)) {
1307 			/* something is wrong with this packet */
1308 			do_tx_balance = 0;
1309 			break;
1310 		}
1311 
1312 		if (ipx_hdr(skb)->ipx_type != IPX_TYPE_NCP) {
1313 			/* The only protocol worth balancing in
1314 			 * this family since it has an "ARP" like
1315 			 * mechanism
1316 			 */
1317 			do_tx_balance = 0;
1318 			break;
1319 		}
1320 
1321 		hash_start = (char*)eth_data->h_dest;
1322 		hash_size = ETH_ALEN;
1323 		break;
1324 	case ETH_P_ARP:
1325 		do_tx_balance = 0;
1326 		if (bond_info->rlb_enabled) {
1327 			tx_slave = rlb_arp_xmit(skb, bond);
1328 		}
1329 		break;
1330 	default:
1331 		do_tx_balance = 0;
1332 		break;
1333 	}
1334 
1335 	if (do_tx_balance) {
1336 		hash_index = _simple_hash(hash_start, hash_size);
1337 		tx_slave = tlb_choose_channel(bond, hash_index, skb->len);
1338 	}
1339 
1340 	if (!tx_slave) {
1341 		/* unbalanced or unassigned, send through primary */
1342 		tx_slave = bond->curr_active_slave;
1343 		bond_info->unbalanced_load += skb->len;
1344 	}
1345 
1346 	if (tx_slave && SLAVE_IS_OK(tx_slave)) {
1347 		if (tx_slave != bond->curr_active_slave) {
1348 			memcpy(eth_data->h_source,
1349 			       tx_slave->dev->dev_addr,
1350 			       ETH_ALEN);
1351 		}
1352 
1353 		res = bond_dev_queue_xmit(bond, skb, tx_slave->dev);
1354 	} else {
1355 		if (tx_slave) {
1356 			tlb_clear_slave(bond, tx_slave, 0);
1357 		}
1358 	}
1359 
1360 out:
1361 	if (res) {
1362 		/* no suitable interface, frame not sent */
1363 		dev_kfree_skb(skb);
1364 	}
1365 	read_unlock(&bond->curr_slave_lock);
1366 	read_unlock(&bond->lock);
1367 	return 0;
1368 }
1369 
1370 void bond_alb_monitor(struct bonding *bond)
1371 {
1372 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1373 	struct slave *slave;
1374 	int i;
1375 
1376 	read_lock(&bond->lock);
1377 
1378 	if (bond->kill_timers) {
1379 		goto out;
1380 	}
1381 
1382 	if (bond->slave_cnt == 0) {
1383 		bond_info->tx_rebalance_counter = 0;
1384 		bond_info->lp_counter = 0;
1385 		goto re_arm;
1386 	}
1387 
1388 	bond_info->tx_rebalance_counter++;
1389 	bond_info->lp_counter++;
1390 
1391 	/* send learning packets */
1392 	if (bond_info->lp_counter >= BOND_ALB_LP_TICKS) {
1393 		/* change of curr_active_slave involves swapping of mac addresses.
1394 		 * in order to avoid this swapping from happening while
1395 		 * sending the learning packets, the curr_slave_lock must be held for
1396 		 * read.
1397 		 */
1398 		read_lock(&bond->curr_slave_lock);
1399 
1400 		bond_for_each_slave(bond, slave, i) {
1401 			alb_send_learning_packets(slave, slave->dev->dev_addr);
1402 		}
1403 
1404 		read_unlock(&bond->curr_slave_lock);
1405 
1406 		bond_info->lp_counter = 0;
1407 	}
1408 
1409 	/* rebalance tx traffic */
1410 	if (bond_info->tx_rebalance_counter >= BOND_TLB_REBALANCE_TICKS) {
1411 
1412 		read_lock(&bond->curr_slave_lock);
1413 
1414 		bond_for_each_slave(bond, slave, i) {
1415 			tlb_clear_slave(bond, slave, 1);
1416 			if (slave == bond->curr_active_slave) {
1417 				SLAVE_TLB_INFO(slave).load =
1418 					bond_info->unbalanced_load /
1419 						BOND_TLB_REBALANCE_INTERVAL;
1420 				bond_info->unbalanced_load = 0;
1421 			}
1422 		}
1423 
1424 		read_unlock(&bond->curr_slave_lock);
1425 
1426 		bond_info->tx_rebalance_counter = 0;
1427 	}
1428 
1429 	/* handle rlb stuff */
1430 	if (bond_info->rlb_enabled) {
1431 		/* the following code changes the promiscuity of the
1432 		 * the curr_active_slave. It needs to be locked with a
1433 		 * write lock to protect from other code that also
1434 		 * sets the promiscuity.
1435 		 */
1436 		write_lock(&bond->curr_slave_lock);
1437 
1438 		if (bond_info->primary_is_promisc &&
1439 		    (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {
1440 
1441 			bond_info->rlb_promisc_timeout_counter = 0;
1442 
1443 			/* If the primary was set to promiscuous mode
1444 			 * because a slave was disabled then
1445 			 * it can now leave promiscuous mode.
1446 			 */
1447 			dev_set_promiscuity(bond->curr_active_slave->dev, -1);
1448 			bond_info->primary_is_promisc = 0;
1449 		}
1450 
1451 		write_unlock(&bond->curr_slave_lock);
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 	mod_timer(&(bond_info->alb_timer), jiffies + 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 	write_lock_bh(&bond->lock);
1496 
1497 	res = alb_handle_addr_collision_on_attach(bond, slave);
1498 
1499 	write_unlock_bh(&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 /* Caller must hold bond lock for write */
1518 void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
1519 {
1520 	if (bond->slave_cnt > 1) {
1521 		alb_change_hw_addr_on_detach(bond, slave);
1522 	}
1523 
1524 	tlb_clear_slave(bond, slave, 0);
1525 
1526 	if (bond->alb_info.rlb_enabled) {
1527 		bond->alb_info.next_rx_slave = NULL;
1528 		rlb_clear_slave(bond, slave);
1529 	}
1530 }
1531 
1532 /* Caller must hold bond lock for read */
1533 void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link)
1534 {
1535 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1536 
1537 	if (link == BOND_LINK_DOWN) {
1538 		tlb_clear_slave(bond, slave, 0);
1539 		if (bond->alb_info.rlb_enabled) {
1540 			rlb_clear_slave(bond, slave);
1541 		}
1542 	} else if (link == BOND_LINK_UP) {
1543 		/* order a rebalance ASAP */
1544 		bond_info->tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1545 		if (bond->alb_info.rlb_enabled) {
1546 			bond->alb_info.rlb_rebalance = 1;
1547 			/* If the updelay module parameter is smaller than the
1548 			 * forwarding delay of the switch the rebalance will
1549 			 * not work because the rebalance arp replies will
1550 			 * not be forwarded to the clients..
1551 			 */
1552 		}
1553 	}
1554 }
1555 
1556 /**
1557  * bond_alb_handle_active_change - assign new curr_active_slave
1558  * @bond: our bonding struct
1559  * @new_slave: new slave to assign
1560  *
1561  * Set the bond->curr_active_slave to @new_slave and handle
1562  * mac address swapping and promiscuity changes as needed.
1563  *
1564  * Caller must hold bond curr_slave_lock for write (or bond lock for write)
1565  */
1566 void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
1567 {
1568 	struct slave *swap_slave;
1569 	int i;
1570 
1571 	if (bond->curr_active_slave == new_slave) {
1572 		return;
1573 	}
1574 
1575 	if (bond->curr_active_slave && bond->alb_info.primary_is_promisc) {
1576 		dev_set_promiscuity(bond->curr_active_slave->dev, -1);
1577 		bond->alb_info.primary_is_promisc = 0;
1578 		bond->alb_info.rlb_promisc_timeout_counter = 0;
1579 	}
1580 
1581 	swap_slave = bond->curr_active_slave;
1582 	bond->curr_active_slave = new_slave;
1583 
1584 	if (!new_slave || (bond->slave_cnt == 0)) {
1585 		return;
1586 	}
1587 
1588 	/* set the new curr_active_slave to the bonds mac address
1589 	 * i.e. swap mac addresses of old curr_active_slave and new curr_active_slave
1590 	 */
1591 	if (!swap_slave) {
1592 		struct slave *tmp_slave;
1593 		/* find slave that is holding the bond's mac address */
1594 		bond_for_each_slave(bond, tmp_slave, i) {
1595 			if (!memcmp(tmp_slave->dev->dev_addr,
1596 				    bond->dev->dev_addr, ETH_ALEN)) {
1597 				swap_slave = tmp_slave;
1598 				break;
1599 			}
1600 		}
1601 	}
1602 
1603 	/* curr_active_slave must be set before calling alb_swap_mac_addr */
1604 	if (swap_slave) {
1605 		/* swap mac address */
1606 		alb_swap_mac_addr(bond, swap_slave, new_slave);
1607 	} else {
1608 		/* set the new_slave to the bond mac address */
1609 		alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr,
1610 				       bond->alb_info.rlb_enabled);
1611 		/* fasten bond mac on new current slave */
1612 		alb_send_learning_packets(new_slave, bond->dev->dev_addr);
1613 	}
1614 }
1615 
1616 int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
1617 {
1618 	struct bonding *bond = bond_dev->priv;
1619 	struct sockaddr *sa = addr;
1620 	struct slave *slave, *swap_slave;
1621 	int res;
1622 	int i;
1623 
1624 	if (!is_valid_ether_addr(sa->sa_data)) {
1625 		return -EADDRNOTAVAIL;
1626 	}
1627 
1628 	res = alb_set_mac_address(bond, addr);
1629 	if (res) {
1630 		return res;
1631 	}
1632 
1633 	memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);
1634 
1635 	/* If there is no curr_active_slave there is nothing else to do.
1636 	 * Otherwise we'll need to pass the new address to it and handle
1637 	 * duplications.
1638 	 */
1639 	if (!bond->curr_active_slave) {
1640 		return 0;
1641 	}
1642 
1643 	swap_slave = NULL;
1644 
1645 	bond_for_each_slave(bond, slave, i) {
1646 		if (!memcmp(slave->dev->dev_addr, bond_dev->dev_addr, ETH_ALEN)) {
1647 			swap_slave = slave;
1648 			break;
1649 		}
1650 	}
1651 
1652 	if (swap_slave) {
1653 		alb_swap_mac_addr(bond, swap_slave, bond->curr_active_slave);
1654 	} else {
1655 		alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr,
1656 				       bond->alb_info.rlb_enabled);
1657 
1658 		alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
1659 		if (bond->alb_info.rlb_enabled) {
1660 			/* inform clients mac address has changed */
1661 			rlb_req_update_slave_clients(bond, bond->curr_active_slave);
1662 		}
1663 	}
1664 
1665 	return 0;
1666 }
1667 
1668 void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
1669 {
1670 	if (bond->alb_info.current_alb_vlan &&
1671 	    (bond->alb_info.current_alb_vlan->vlan_id == vlan_id)) {
1672 		bond->alb_info.current_alb_vlan = NULL;
1673 	}
1674 
1675 	if (bond->alb_info.rlb_enabled) {
1676 		rlb_clear_vlan(bond, vlan_id);
1677 	}
1678 }
1679 
1680