xref: /linux/drivers/net/bonding/bond_alb.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 	tlb_init_slave(slave);
173 
174 	_unlock_tx_hashtbl(bond);
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 = kzalloc(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 	for (i = 0; i < TLB_HASH_TABLE_SIZE; i++) {
199 		tlb_init_table_entry(&bond_info->tx_hashtbl[i], 1);
200 	}
201 
202 	_unlock_tx_hashtbl(bond);
203 
204 	return 0;
205 }
206 
207 /* Must be called only after all slaves have been released */
208 static void tlb_deinitialize(struct bonding *bond)
209 {
210 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
211 
212 	_lock_tx_hashtbl(bond);
213 
214 	kfree(bond_info->tx_hashtbl);
215 	bond_info->tx_hashtbl = NULL;
216 
217 	_unlock_tx_hashtbl(bond);
218 }
219 
220 /* Caller must hold bond lock for read */
221 static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
222 {
223 	struct slave *slave, *least_loaded;
224 	s64 max_gap;
225 	int i, found = 0;
226 
227 	/* Find the first enabled slave */
228 	bond_for_each_slave(bond, slave, i) {
229 		if (SLAVE_IS_OK(slave)) {
230 			found = 1;
231 			break;
232 		}
233 	}
234 
235 	if (!found) {
236 		return NULL;
237 	}
238 
239 	least_loaded = slave;
240 	max_gap = (s64)(slave->speed << 20) - /* Convert to Megabit per sec */
241 			(s64)(SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
242 
243 	/* Find the slave with the largest gap */
244 	bond_for_each_slave_from(bond, slave, i, least_loaded) {
245 		if (SLAVE_IS_OK(slave)) {
246 			s64 gap = (s64)(slave->speed << 20) -
247 					(s64)(SLAVE_TLB_INFO(slave).load << 3);
248 			if (max_gap < gap) {
249 				least_loaded = slave;
250 				max_gap = gap;
251 			}
252 		}
253 	}
254 
255 	return least_loaded;
256 }
257 
258 /* Caller must hold bond lock for read */
259 static struct slave *tlb_choose_channel(struct bonding *bond, u32 hash_index, u32 skb_len)
260 {
261 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
262 	struct tlb_client_info *hash_table;
263 	struct slave *assigned_slave;
264 
265 	_lock_tx_hashtbl(bond);
266 
267 	hash_table = bond_info->tx_hashtbl;
268 	assigned_slave = hash_table[hash_index].tx_slave;
269 	if (!assigned_slave) {
270 		assigned_slave = tlb_get_least_loaded_slave(bond);
271 
272 		if (assigned_slave) {
273 			struct tlb_slave_info *slave_info =
274 				&(SLAVE_TLB_INFO(assigned_slave));
275 			u32 next_index = slave_info->head;
276 
277 			hash_table[hash_index].tx_slave = assigned_slave;
278 			hash_table[hash_index].next = next_index;
279 			hash_table[hash_index].prev = TLB_NULL_INDEX;
280 
281 			if (next_index != TLB_NULL_INDEX) {
282 				hash_table[next_index].prev = hash_index;
283 			}
284 
285 			slave_info->head = hash_index;
286 			slave_info->load +=
287 				hash_table[hash_index].load_history;
288 		}
289 	}
290 
291 	if (assigned_slave) {
292 		hash_table[hash_index].tx_bytes += skb_len;
293 	}
294 
295 	_unlock_tx_hashtbl(bond);
296 
297 	return assigned_slave;
298 }
299 
300 /*********************** rlb specific functions ***************************/
301 static inline void _lock_rx_hashtbl(struct bonding *bond)
302 {
303 	spin_lock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
304 }
305 
306 static inline void _unlock_rx_hashtbl(struct bonding *bond)
307 {
308 	spin_unlock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
309 }
310 
311 /* when an ARP REPLY is received from a client update its info
312  * in the rx_hashtbl
313  */
314 static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
315 {
316 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
317 	struct rlb_client_info *client_info;
318 	u32 hash_index;
319 
320 	_lock_rx_hashtbl(bond);
321 
322 	hash_index = _simple_hash((u8*)&(arp->ip_src), sizeof(arp->ip_src));
323 	client_info = &(bond_info->rx_hashtbl[hash_index]);
324 
325 	if ((client_info->assigned) &&
326 	    (client_info->ip_src == arp->ip_dst) &&
327 	    (client_info->ip_dst == arp->ip_src)) {
328 		/* update the clients MAC address */
329 		memcpy(client_info->mac_dst, arp->mac_src, ETH_ALEN);
330 		client_info->ntt = 1;
331 		bond_info->rx_ntt = 1;
332 	}
333 
334 	_unlock_rx_hashtbl(bond);
335 }
336 
337 static int rlb_arp_recv(struct sk_buff *skb, struct net_device *bond_dev, struct packet_type *ptype, struct net_device *orig_dev)
338 {
339 	struct bonding *bond = bond_dev->priv;
340 	struct arp_pkt *arp = (struct arp_pkt *)skb->data;
341 	int res = NET_RX_DROP;
342 
343 	if (!(bond_dev->flags & IFF_MASTER))
344 		goto out;
345 
346 	if (!arp) {
347 		dprintk("Packet has no ARP data\n");
348 		goto out;
349 	}
350 
351 	if (skb->len < sizeof(struct arp_pkt)) {
352 		dprintk("Packet is too small to be an ARP\n");
353 		goto out;
354 	}
355 
356 	if (arp->op_code == htons(ARPOP_REPLY)) {
357 		/* update rx hash table for this ARP */
358 		rlb_update_entry_from_arp(bond, arp);
359 		dprintk("Server received an ARP Reply from client\n");
360 	}
361 
362 	res = NET_RX_SUCCESS;
363 
364 out:
365 	dev_kfree_skb(skb);
366 
367 	return res;
368 }
369 
370 /* Caller must hold bond lock for read */
371 static struct slave *rlb_next_rx_slave(struct bonding *bond)
372 {
373 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
374 	struct slave *rx_slave, *slave, *start_at;
375 	int i = 0;
376 
377 	if (bond_info->next_rx_slave) {
378 		start_at = bond_info->next_rx_slave;
379 	} else {
380 		start_at = bond->first_slave;
381 	}
382 
383 	rx_slave = NULL;
384 
385 	bond_for_each_slave_from(bond, slave, i, start_at) {
386 		if (SLAVE_IS_OK(slave)) {
387 			if (!rx_slave) {
388 				rx_slave = slave;
389 			} else if (slave->speed > rx_slave->speed) {
390 				rx_slave = slave;
391 			}
392 		}
393 	}
394 
395 	if (rx_slave) {
396 		bond_info->next_rx_slave = rx_slave->next;
397 	}
398 
399 	return rx_slave;
400 }
401 
402 /* teach the switch the mac of a disabled slave
403  * on the primary for fault tolerance
404  *
405  * Caller must hold bond->curr_slave_lock for write or bond lock for write
406  */
407 static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
408 {
409 	if (!bond->curr_active_slave) {
410 		return;
411 	}
412 
413 	if (!bond->alb_info.primary_is_promisc) {
414 		bond->alb_info.primary_is_promisc = 1;
415 		dev_set_promiscuity(bond->curr_active_slave->dev, 1);
416 	}
417 
418 	bond->alb_info.rlb_promisc_timeout_counter = 0;
419 
420 	alb_send_learning_packets(bond->curr_active_slave, addr);
421 }
422 
423 /* slave being removed should not be active at this point
424  *
425  * Caller must hold bond lock for read
426  */
427 static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
428 {
429 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
430 	struct rlb_client_info *rx_hash_table;
431 	u32 index, next_index;
432 
433 	/* clear slave from rx_hashtbl */
434 	_lock_rx_hashtbl(bond);
435 
436 	rx_hash_table = bond_info->rx_hashtbl;
437 	index = bond_info->rx_hashtbl_head;
438 	for (; index != RLB_NULL_INDEX; index = next_index) {
439 		next_index = rx_hash_table[index].next;
440 		if (rx_hash_table[index].slave == slave) {
441 			struct slave *assigned_slave = rlb_next_rx_slave(bond);
442 
443 			if (assigned_slave) {
444 				rx_hash_table[index].slave = assigned_slave;
445 				if (memcmp(rx_hash_table[index].mac_dst,
446 					   mac_bcast, ETH_ALEN)) {
447 					bond_info->rx_hashtbl[index].ntt = 1;
448 					bond_info->rx_ntt = 1;
449 					/* A slave has been removed from the
450 					 * table because it is either disabled
451 					 * or being released. We must retry the
452 					 * update to avoid clients from not
453 					 * being updated & disconnecting when
454 					 * there is stress
455 					 */
456 					bond_info->rlb_update_retry_counter =
457 						RLB_UPDATE_RETRY;
458 				}
459 			} else {  /* there is no active slave */
460 				rx_hash_table[index].slave = NULL;
461 			}
462 		}
463 	}
464 
465 	_unlock_rx_hashtbl(bond);
466 
467 	write_lock(&bond->curr_slave_lock);
468 
469 	if (slave != bond->curr_active_slave) {
470 		rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
471 	}
472 
473 	write_unlock(&bond->curr_slave_lock);
474 }
475 
476 static void rlb_update_client(struct rlb_client_info *client_info)
477 {
478 	int i;
479 
480 	if (!client_info->slave) {
481 		return;
482 	}
483 
484 	for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
485 		struct sk_buff *skb;
486 
487 		skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
488 				 client_info->ip_dst,
489 				 client_info->slave->dev,
490 				 client_info->ip_src,
491 				 client_info->mac_dst,
492 				 client_info->slave->dev->dev_addr,
493 				 client_info->mac_dst);
494 		if (!skb) {
495 			printk(KERN_ERR DRV_NAME
496 			       ": %s: Error: failed to create an ARP packet\n",
497 			       client_info->slave->dev->master->name);
498 			continue;
499 		}
500 
501 		skb->dev = client_info->slave->dev;
502 
503 		if (client_info->tag) {
504 			skb = vlan_put_tag(skb, client_info->vlan_id);
505 			if (!skb) {
506 				printk(KERN_ERR DRV_NAME
507 				       ": %s: Error: failed to insert VLAN tag\n",
508 				       client_info->slave->dev->master->name);
509 				continue;
510 			}
511 		}
512 
513 		arp_xmit(skb);
514 	}
515 }
516 
517 /* sends ARP REPLIES that update the clients that need updating */
518 static void rlb_update_rx_clients(struct bonding *bond)
519 {
520 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
521 	struct rlb_client_info *client_info;
522 	u32 hash_index;
523 
524 	_lock_rx_hashtbl(bond);
525 
526 	hash_index = bond_info->rx_hashtbl_head;
527 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
528 		client_info = &(bond_info->rx_hashtbl[hash_index]);
529 		if (client_info->ntt) {
530 			rlb_update_client(client_info);
531 			if (bond_info->rlb_update_retry_counter == 0) {
532 				client_info->ntt = 0;
533 			}
534 		}
535 	}
536 
537 	/* do not update the entries again untill this counter is zero so that
538 	 * not to confuse the clients.
539 	 */
540 	bond_info->rlb_update_delay_counter = RLB_UPDATE_DELAY;
541 
542 	_unlock_rx_hashtbl(bond);
543 }
544 
545 /* The slave was assigned a new mac address - update the clients */
546 static void rlb_req_update_slave_clients(struct bonding *bond, struct slave *slave)
547 {
548 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
549 	struct rlb_client_info *client_info;
550 	int ntt = 0;
551 	u32 hash_index;
552 
553 	_lock_rx_hashtbl(bond);
554 
555 	hash_index = bond_info->rx_hashtbl_head;
556 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
557 		client_info = &(bond_info->rx_hashtbl[hash_index]);
558 
559 		if ((client_info->slave == slave) &&
560 		    memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
561 			client_info->ntt = 1;
562 			ntt = 1;
563 		}
564 	}
565 
566 	// update the team's flag only after the whole iteration
567 	if (ntt) {
568 		bond_info->rx_ntt = 1;
569 		//fasten the change
570 		bond_info->rlb_update_retry_counter = RLB_UPDATE_RETRY;
571 	}
572 
573 	_unlock_rx_hashtbl(bond);
574 }
575 
576 /* mark all clients using src_ip to be updated */
577 static void rlb_req_update_subnet_clients(struct bonding *bond, u32 src_ip)
578 {
579 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
580 	struct rlb_client_info *client_info;
581 	u32 hash_index;
582 
583 	_lock_rx_hashtbl(bond);
584 
585 	hash_index = bond_info->rx_hashtbl_head;
586 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
587 		client_info = &(bond_info->rx_hashtbl[hash_index]);
588 
589 		if (!client_info->slave) {
590 			printk(KERN_ERR DRV_NAME
591 			       ": %s: Error: found a client with no channel in "
592 			       "the client's hash table\n",
593 			       bond->dev->name);
594 			continue;
595 		}
596 		/*update all clients using this src_ip, that are not assigned
597 		 * to the team's address (curr_active_slave) and have a known
598 		 * unicast mac address.
599 		 */
600 		if ((client_info->ip_src == src_ip) &&
601 		    memcmp(client_info->slave->dev->dev_addr,
602 			   bond->dev->dev_addr, ETH_ALEN) &&
603 		    memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
604 			client_info->ntt = 1;
605 			bond_info->rx_ntt = 1;
606 		}
607 	}
608 
609 	_unlock_rx_hashtbl(bond);
610 }
611 
612 /* Caller must hold both bond and ptr locks for read */
613 static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bond)
614 {
615 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
616 	struct arp_pkt *arp = (struct arp_pkt *)skb->nh.raw;
617 	struct slave *assigned_slave;
618 	struct rlb_client_info *client_info;
619 	u32 hash_index = 0;
620 
621 	_lock_rx_hashtbl(bond);
622 
623 	hash_index = _simple_hash((u8 *)&arp->ip_dst, sizeof(arp->ip_src));
624 	client_info = &(bond_info->rx_hashtbl[hash_index]);
625 
626 	if (client_info->assigned) {
627 		if ((client_info->ip_src == arp->ip_src) &&
628 		    (client_info->ip_dst == arp->ip_dst)) {
629 			/* the entry is already assigned to this client */
630 			if (memcmp(arp->mac_dst, mac_bcast, ETH_ALEN)) {
631 				/* update mac address from arp */
632 				memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
633 			}
634 
635 			assigned_slave = client_info->slave;
636 			if (assigned_slave) {
637 				_unlock_rx_hashtbl(bond);
638 				return assigned_slave;
639 			}
640 		} else {
641 			/* the entry is already assigned to some other client,
642 			 * move the old client to primary (curr_active_slave) so
643 			 * that the new client can be assigned to this entry.
644 			 */
645 			if (bond->curr_active_slave &&
646 			    client_info->slave != bond->curr_active_slave) {
647 				client_info->slave = bond->curr_active_slave;
648 				rlb_update_client(client_info);
649 			}
650 		}
651 	}
652 	/* assign a new slave */
653 	assigned_slave = rlb_next_rx_slave(bond);
654 
655 	if (assigned_slave) {
656 		client_info->ip_src = arp->ip_src;
657 		client_info->ip_dst = arp->ip_dst;
658 		/* arp->mac_dst is broadcast for arp reqeusts.
659 		 * will be updated with clients actual unicast mac address
660 		 * upon receiving an arp reply.
661 		 */
662 		memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
663 		client_info->slave = assigned_slave;
664 
665 		if (memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
666 			client_info->ntt = 1;
667 			bond->alb_info.rx_ntt = 1;
668 		} else {
669 			client_info->ntt = 0;
670 		}
671 
672 		if (!list_empty(&bond->vlan_list)) {
673 			unsigned short vlan_id;
674 			int res = vlan_get_tag(skb, &vlan_id);
675 			if (!res) {
676 				client_info->tag = 1;
677 				client_info->vlan_id = vlan_id;
678 			}
679 		}
680 
681 		if (!client_info->assigned) {
682 			u32 prev_tbl_head = bond_info->rx_hashtbl_head;
683 			bond_info->rx_hashtbl_head = hash_index;
684 			client_info->next = prev_tbl_head;
685 			if (prev_tbl_head != RLB_NULL_INDEX) {
686 				bond_info->rx_hashtbl[prev_tbl_head].prev =
687 					hash_index;
688 			}
689 			client_info->assigned = 1;
690 		}
691 	}
692 
693 	_unlock_rx_hashtbl(bond);
694 
695 	return assigned_slave;
696 }
697 
698 /* chooses (and returns) transmit channel for arp reply
699  * does not choose channel for other arp types since they are
700  * sent on the curr_active_slave
701  */
702 static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
703 {
704 	struct arp_pkt *arp = (struct arp_pkt *)skb->nh.raw;
705 	struct slave *tx_slave = NULL;
706 
707 	if (arp->op_code == __constant_htons(ARPOP_REPLY)) {
708 		/* the arp must be sent on the selected
709 		* rx channel
710 		*/
711 		tx_slave = rlb_choose_channel(skb, bond);
712 		if (tx_slave) {
713 			memcpy(arp->mac_src,tx_slave->dev->dev_addr, ETH_ALEN);
714 		}
715 		dprintk("Server sent ARP Reply packet\n");
716 	} else if (arp->op_code == __constant_htons(ARPOP_REQUEST)) {
717 		/* Create an entry in the rx_hashtbl for this client as a
718 		 * place holder.
719 		 * When the arp reply is received the entry will be updated
720 		 * with the correct unicast address of the client.
721 		 */
722 		rlb_choose_channel(skb, bond);
723 
724 		/* The ARP relpy packets must be delayed so that
725 		 * they can cancel out the influence of the ARP request.
726 		 */
727 		bond->alb_info.rlb_update_delay_counter = RLB_UPDATE_DELAY;
728 
729 		/* arp requests are broadcast and are sent on the primary
730 		 * the arp request will collapse all clients on the subnet to
731 		 * the primary slave. We must register these clients to be
732 		 * updated with their assigned mac.
733 		 */
734 		rlb_req_update_subnet_clients(bond, arp->ip_src);
735 		dprintk("Server sent ARP Request packet\n");
736 	}
737 
738 	return tx_slave;
739 }
740 
741 /* Caller must hold bond lock for read */
742 static void rlb_rebalance(struct bonding *bond)
743 {
744 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
745 	struct slave *assigned_slave;
746 	struct rlb_client_info *client_info;
747 	int ntt;
748 	u32 hash_index;
749 
750 	_lock_rx_hashtbl(bond);
751 
752 	ntt = 0;
753 	hash_index = bond_info->rx_hashtbl_head;
754 	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
755 		client_info = &(bond_info->rx_hashtbl[hash_index]);
756 		assigned_slave = rlb_next_rx_slave(bond);
757 		if (assigned_slave && (client_info->slave != assigned_slave)) {
758 			client_info->slave = assigned_slave;
759 			client_info->ntt = 1;
760 			ntt = 1;
761 		}
762 	}
763 
764 	/* update the team's flag only after the whole iteration */
765 	if (ntt) {
766 		bond_info->rx_ntt = 1;
767 	}
768 	_unlock_rx_hashtbl(bond);
769 }
770 
771 /* Caller must hold rx_hashtbl lock */
772 static void rlb_init_table_entry(struct rlb_client_info *entry)
773 {
774 	memset(entry, 0, sizeof(struct rlb_client_info));
775 	entry->next = RLB_NULL_INDEX;
776 	entry->prev = RLB_NULL_INDEX;
777 }
778 
779 static int rlb_initialize(struct bonding *bond)
780 {
781 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
782 	struct packet_type *pk_type = &(BOND_ALB_INFO(bond).rlb_pkt_type);
783 	struct rlb_client_info	*new_hashtbl;
784 	int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
785 	int i;
786 
787 	spin_lock_init(&(bond_info->rx_hashtbl_lock));
788 
789 	new_hashtbl = kmalloc(size, GFP_KERNEL);
790 	if (!new_hashtbl) {
791 		printk(KERN_ERR DRV_NAME
792 		       ": %s: Error: Failed to allocate RLB hash table\n",
793 		       bond->dev->name);
794 		return -1;
795 	}
796 	_lock_rx_hashtbl(bond);
797 
798 	bond_info->rx_hashtbl = new_hashtbl;
799 
800 	bond_info->rx_hashtbl_head = RLB_NULL_INDEX;
801 
802 	for (i = 0; i < RLB_HASH_TABLE_SIZE; i++) {
803 		rlb_init_table_entry(bond_info->rx_hashtbl + i);
804 	}
805 
806 	_unlock_rx_hashtbl(bond);
807 
808 	/*initialize packet type*/
809 	pk_type->type = __constant_htons(ETH_P_ARP);
810 	pk_type->dev = bond->dev;
811 	pk_type->func = rlb_arp_recv;
812 
813 	/* register to receive ARPs */
814 	dev_add_pack(pk_type);
815 
816 	return 0;
817 }
818 
819 static void rlb_deinitialize(struct bonding *bond)
820 {
821 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
822 
823 	dev_remove_pack(&(bond_info->rlb_pkt_type));
824 
825 	_lock_rx_hashtbl(bond);
826 
827 	kfree(bond_info->rx_hashtbl);
828 	bond_info->rx_hashtbl = NULL;
829 	bond_info->rx_hashtbl_head = RLB_NULL_INDEX;
830 
831 	_unlock_rx_hashtbl(bond);
832 }
833 
834 static void rlb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
835 {
836 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
837 	u32 curr_index;
838 
839 	_lock_rx_hashtbl(bond);
840 
841 	curr_index = bond_info->rx_hashtbl_head;
842 	while (curr_index != RLB_NULL_INDEX) {
843 		struct rlb_client_info *curr = &(bond_info->rx_hashtbl[curr_index]);
844 		u32 next_index = bond_info->rx_hashtbl[curr_index].next;
845 		u32 prev_index = bond_info->rx_hashtbl[curr_index].prev;
846 
847 		if (curr->tag && (curr->vlan_id == vlan_id)) {
848 			if (curr_index == bond_info->rx_hashtbl_head) {
849 				bond_info->rx_hashtbl_head = next_index;
850 			}
851 			if (prev_index != RLB_NULL_INDEX) {
852 				bond_info->rx_hashtbl[prev_index].next = next_index;
853 			}
854 			if (next_index != RLB_NULL_INDEX) {
855 				bond_info->rx_hashtbl[next_index].prev = prev_index;
856 			}
857 
858 			rlb_init_table_entry(curr);
859 		}
860 
861 		curr_index = next_index;
862 	}
863 
864 	_unlock_rx_hashtbl(bond);
865 }
866 
867 /*********************** tlb/rlb shared functions *********************/
868 
869 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
870 {
871 	struct bonding *bond = bond_get_bond_by_slave(slave);
872 	struct learning_pkt pkt;
873 	int size = sizeof(struct learning_pkt);
874 	int i;
875 
876 	memset(&pkt, 0, size);
877 	memcpy(pkt.mac_dst, mac_addr, ETH_ALEN);
878 	memcpy(pkt.mac_src, mac_addr, ETH_ALEN);
879 	pkt.type = __constant_htons(ETH_P_LOOP);
880 
881 	for (i = 0; i < MAX_LP_BURST; i++) {
882 		struct sk_buff *skb;
883 		char *data;
884 
885 		skb = dev_alloc_skb(size);
886 		if (!skb) {
887 			return;
888 		}
889 
890 		data = skb_put(skb, size);
891 		memcpy(data, &pkt, size);
892 
893 		skb->mac.raw = data;
894 		skb->nh.raw = data + ETH_HLEN;
895 		skb->protocol = pkt.type;
896 		skb->priority = TC_PRIO_CONTROL;
897 		skb->dev = slave->dev;
898 
899 		if (!list_empty(&bond->vlan_list)) {
900 			struct vlan_entry *vlan;
901 
902 			vlan = bond_next_vlan(bond,
903 					      bond->alb_info.current_alb_vlan);
904 
905 			bond->alb_info.current_alb_vlan = vlan;
906 			if (!vlan) {
907 				kfree_skb(skb);
908 				continue;
909 			}
910 
911 			skb = vlan_put_tag(skb, vlan->vlan_id);
912 			if (!skb) {
913 				printk(KERN_ERR DRV_NAME
914 				       ": %s: Error: failed to insert VLAN tag\n",
915 				       bond->dev->name);
916 				continue;
917 			}
918 		}
919 
920 		dev_queue_xmit(skb);
921 	}
922 }
923 
924 /* hw is a boolean parameter that determines whether we should try and
925  * set the hw address of the device as well as the hw address of the
926  * net_device
927  */
928 static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[], int hw)
929 {
930 	struct net_device *dev = slave->dev;
931 	struct sockaddr s_addr;
932 
933 	if (!hw) {
934 		memcpy(dev->dev_addr, addr, dev->addr_len);
935 		return 0;
936 	}
937 
938 	/* for rlb each slave must have a unique hw mac addresses so that */
939 	/* each slave will receive packets destined to a different mac */
940 	memcpy(s_addr.sa_data, addr, dev->addr_len);
941 	s_addr.sa_family = dev->type;
942 	if (dev_set_mac_address(dev, &s_addr)) {
943 		printk(KERN_ERR DRV_NAME
944 		       ": %s: Error: dev_set_mac_address of dev %s failed! ALB "
945 		       "mode requires that the base driver support setting "
946 		       "the hw address also when the network device's "
947 		       "interface is open\n",
948 		       dev->master->name, dev->name);
949 		return -EOPNOTSUPP;
950 	}
951 	return 0;
952 }
953 
954 /* Caller must hold bond lock for write or curr_slave_lock for write*/
955 static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct slave *slave2)
956 {
957 	struct slave *disabled_slave = NULL;
958 	u8 tmp_mac_addr[ETH_ALEN];
959 	int slaves_state_differ;
960 
961 	slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2));
962 
963 	memcpy(tmp_mac_addr, slave1->dev->dev_addr, ETH_ALEN);
964 	alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr, bond->alb_info.rlb_enabled);
965 	alb_set_slave_mac_addr(slave2, tmp_mac_addr, bond->alb_info.rlb_enabled);
966 
967 	/* fasten the change in the switch */
968 	if (SLAVE_IS_OK(slave1)) {
969 		alb_send_learning_packets(slave1, slave1->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, slave1);
975 		}
976 	} else {
977 		disabled_slave = slave1;
978 	}
979 
980 	if (SLAVE_IS_OK(slave2)) {
981 		alb_send_learning_packets(slave2, slave2->dev->dev_addr);
982 		if (bond->alb_info.rlb_enabled) {
983 			/* inform the clients that the mac address
984 			 * has changed
985 			 */
986 			rlb_req_update_slave_clients(bond, slave2);
987 		}
988 	} else {
989 		disabled_slave = slave2;
990 	}
991 
992 	if (bond->alb_info.rlb_enabled && slaves_state_differ) {
993 		/* A disabled slave was assigned an active mac addr */
994 		rlb_teach_disabled_mac_on_primary(bond,
995 						  disabled_slave->dev->dev_addr);
996 	}
997 }
998 
999 /**
1000  * alb_change_hw_addr_on_detach
1001  * @bond: bonding we're working on
1002  * @slave: the slave that was just detached
1003  *
1004  * We assume that @slave was already detached from the slave list.
1005  *
1006  * If @slave's permanent hw address is different both from its current
1007  * address and from @bond's address, then somewhere in the bond there's
1008  * a slave that has @slave's permanet address as its current address.
1009  * We'll make sure that that slave no longer uses @slave's permanent address.
1010  *
1011  * Caller must hold bond lock
1012  */
1013 static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave)
1014 {
1015 	int perm_curr_diff;
1016 	int perm_bond_diff;
1017 
1018 	perm_curr_diff = memcmp(slave->perm_hwaddr,
1019 				slave->dev->dev_addr,
1020 				ETH_ALEN);
1021 	perm_bond_diff = memcmp(slave->perm_hwaddr,
1022 				bond->dev->dev_addr,
1023 				ETH_ALEN);
1024 
1025 	if (perm_curr_diff && perm_bond_diff) {
1026 		struct slave *tmp_slave;
1027 		int i, found = 0;
1028 
1029 		bond_for_each_slave(bond, tmp_slave, i) {
1030 			if (!memcmp(slave->perm_hwaddr,
1031 				    tmp_slave->dev->dev_addr,
1032 				    ETH_ALEN)) {
1033 				found = 1;
1034 				break;
1035 			}
1036 		}
1037 
1038 		if (found) {
1039 			alb_swap_mac_addr(bond, slave, tmp_slave);
1040 		}
1041 	}
1042 }
1043 
1044 /**
1045  * alb_handle_addr_collision_on_attach
1046  * @bond: bonding we're working on
1047  * @slave: the slave that was just attached
1048  *
1049  * checks uniqueness of slave's mac address and handles the case the
1050  * new slave uses the bonds mac address.
1051  *
1052  * If the permanent hw address of @slave is @bond's hw address, we need to
1053  * find a different hw address to give @slave, that isn't in use by any other
1054  * slave in the bond. This address must be, of course, one of the premanent
1055  * addresses of the other slaves.
1056  *
1057  * We go over the slave list, and for each slave there we compare its
1058  * permanent hw address with the current address of all the other slaves.
1059  * If no match was found, then we've found a slave with a permanent address
1060  * that isn't used by any other slave in the bond, so we can assign it to
1061  * @slave.
1062  *
1063  * assumption: this function is called before @slave is attached to the
1064  * 	       bond slave list.
1065  *
1066  * caller must hold the bond lock for write since the mac addresses are compared
1067  * and may be swapped.
1068  */
1069 static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
1070 {
1071 	struct slave *tmp_slave1, *tmp_slave2, *free_mac_slave;
1072 	struct slave *has_bond_addr = bond->curr_active_slave;
1073 	int i, j, found = 0;
1074 
1075 	if (bond->slave_cnt == 0) {
1076 		/* this is the first slave */
1077 		return 0;
1078 	}
1079 
1080 	/* if slave's mac address differs from bond's mac address
1081 	 * check uniqueness of slave's mac address against the other
1082 	 * slaves in the bond.
1083 	 */
1084 	if (memcmp(slave->perm_hwaddr, bond->dev->dev_addr, ETH_ALEN)) {
1085 		bond_for_each_slave(bond, tmp_slave1, i) {
1086 			if (!memcmp(tmp_slave1->dev->dev_addr, slave->dev->dev_addr,
1087 				    ETH_ALEN)) {
1088 				found = 1;
1089 				break;
1090 			}
1091 		}
1092 
1093 		if (!found)
1094 			return 0;
1095 
1096 		/* Try setting slave mac to bond address and fall-through
1097 		   to code handling that situation below... */
1098 		alb_set_slave_mac_addr(slave, bond->dev->dev_addr,
1099 				       bond->alb_info.rlb_enabled);
1100 	}
1101 
1102 	/* The slave's address is equal to the address of the bond.
1103 	 * Search for a spare address in the bond for this slave.
1104 	 */
1105 	free_mac_slave = NULL;
1106 
1107 	bond_for_each_slave(bond, tmp_slave1, i) {
1108 		found = 0;
1109 		bond_for_each_slave(bond, tmp_slave2, j) {
1110 			if (!memcmp(tmp_slave1->perm_hwaddr,
1111 				    tmp_slave2->dev->dev_addr,
1112 				    ETH_ALEN)) {
1113 				found = 1;
1114 				break;
1115 			}
1116 		}
1117 
1118 		if (!found) {
1119 			/* no slave has tmp_slave1's perm addr
1120 			 * as its curr addr
1121 			 */
1122 			free_mac_slave = tmp_slave1;
1123 			break;
1124 		}
1125 
1126 		if (!has_bond_addr) {
1127 			if (!memcmp(tmp_slave1->dev->dev_addr,
1128 				    bond->dev->dev_addr,
1129 				    ETH_ALEN)) {
1130 
1131 				has_bond_addr = tmp_slave1;
1132 			}
1133 		}
1134 	}
1135 
1136 	if (free_mac_slave) {
1137 		alb_set_slave_mac_addr(slave, free_mac_slave->perm_hwaddr,
1138 				       bond->alb_info.rlb_enabled);
1139 
1140 		printk(KERN_WARNING DRV_NAME
1141 		       ": %s: Warning: the hw address of slave %s is in use by "
1142 		       "the bond; giving it the hw address of %s\n",
1143 		       bond->dev->name, slave->dev->name, free_mac_slave->dev->name);
1144 
1145 	} else if (has_bond_addr) {
1146 		printk(KERN_ERR DRV_NAME
1147 		       ": %s: Error: the hw address of slave %s is in use by the "
1148 		       "bond; couldn't find a slave with a free hw address to "
1149 		       "give it (this should not have happened)\n",
1150 		       bond->dev->name, slave->dev->name);
1151 		return -EFAULT;
1152 	}
1153 
1154 	return 0;
1155 }
1156 
1157 /**
1158  * alb_set_mac_address
1159  * @bond:
1160  * @addr:
1161  *
1162  * In TLB mode all slaves are configured to the bond's hw address, but set
1163  * their dev_addr field to different addresses (based on their permanent hw
1164  * addresses).
1165  *
1166  * For each slave, this function sets the interface to the new address and then
1167  * changes its dev_addr field to its previous value.
1168  *
1169  * Unwinding assumes bond's mac address has not yet changed.
1170  */
1171 static int alb_set_mac_address(struct bonding *bond, void *addr)
1172 {
1173 	struct sockaddr sa;
1174 	struct slave *slave, *stop_at;
1175 	char tmp_addr[ETH_ALEN];
1176 	int res;
1177 	int i;
1178 
1179 	if (bond->alb_info.rlb_enabled) {
1180 		return 0;
1181 	}
1182 
1183 	bond_for_each_slave(bond, slave, i) {
1184 		if (slave->dev->set_mac_address == NULL) {
1185 			res = -EOPNOTSUPP;
1186 			goto unwind;
1187 		}
1188 
1189 		/* save net_device's current hw address */
1190 		memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
1191 
1192 		res = dev_set_mac_address(slave->dev, addr);
1193 
1194 		/* restore net_device's hw address */
1195 		memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
1196 
1197 		if (res) {
1198 			goto unwind;
1199 		}
1200 	}
1201 
1202 	return 0;
1203 
1204 unwind:
1205 	memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
1206 	sa.sa_family = bond->dev->type;
1207 
1208 	/* unwind from head to the slave that failed */
1209 	stop_at = slave;
1210 	bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at) {
1211 		memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
1212 		dev_set_mac_address(slave->dev, &sa);
1213 		memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
1214 	}
1215 
1216 	return res;
1217 }
1218 
1219 /************************ exported alb funcions ************************/
1220 
1221 int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
1222 {
1223 	int res;
1224 
1225 	res = tlb_initialize(bond);
1226 	if (res) {
1227 		return res;
1228 	}
1229 
1230 	if (rlb_enabled) {
1231 		bond->alb_info.rlb_enabled = 1;
1232 		/* initialize rlb */
1233 		res = rlb_initialize(bond);
1234 		if (res) {
1235 			tlb_deinitialize(bond);
1236 			return res;
1237 		}
1238 	} else {
1239 		bond->alb_info.rlb_enabled = 0;
1240 	}
1241 
1242 	return 0;
1243 }
1244 
1245 void bond_alb_deinitialize(struct bonding *bond)
1246 {
1247 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1248 
1249 	tlb_deinitialize(bond);
1250 
1251 	if (bond_info->rlb_enabled) {
1252 		rlb_deinitialize(bond);
1253 	}
1254 }
1255 
1256 int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
1257 {
1258 	struct bonding *bond = bond_dev->priv;
1259 	struct ethhdr *eth_data;
1260 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1261 	struct slave *tx_slave = NULL;
1262 	static const u32 ip_bcast = 0xffffffff;
1263 	int hash_size = 0;
1264 	int do_tx_balance = 1;
1265 	u32 hash_index = 0;
1266 	u8 *hash_start = NULL;
1267 	int res = 1;
1268 
1269 	skb->mac.raw = (unsigned char *)skb->data;
1270 	eth_data = eth_hdr(skb);
1271 
1272 	/* make sure that the curr_active_slave and the slaves list do
1273 	 * not change during tx
1274 	 */
1275 	read_lock(&bond->lock);
1276 	read_lock(&bond->curr_slave_lock);
1277 
1278 	if (!BOND_IS_OK(bond)) {
1279 		goto out;
1280 	}
1281 
1282 	switch (ntohs(skb->protocol)) {
1283 	case ETH_P_IP:
1284 		if ((memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) ||
1285 		    (skb->nh.iph->daddr == ip_bcast) ||
1286 		    (skb->nh.iph->protocol == IPPROTO_IGMP)) {
1287 			do_tx_balance = 0;
1288 			break;
1289 		}
1290 		hash_start = (char*)&(skb->nh.iph->daddr);
1291 		hash_size = sizeof(skb->nh.iph->daddr);
1292 		break;
1293 	case ETH_P_IPV6:
1294 		if (memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) {
1295 			do_tx_balance = 0;
1296 			break;
1297 		}
1298 
1299 		hash_start = (char*)&(skb->nh.ipv6h->daddr);
1300 		hash_size = sizeof(skb->nh.ipv6h->daddr);
1301 		break;
1302 	case ETH_P_IPX:
1303 		if (ipx_hdr(skb)->ipx_checksum !=
1304 		    __constant_htons(IPX_NO_CHECKSUM)) {
1305 			/* something is wrong with this packet */
1306 			do_tx_balance = 0;
1307 			break;
1308 		}
1309 
1310 		if (ipx_hdr(skb)->ipx_type != IPX_TYPE_NCP) {
1311 			/* The only protocol worth balancing in
1312 			 * this family since it has an "ARP" like
1313 			 * mechanism
1314 			 */
1315 			do_tx_balance = 0;
1316 			break;
1317 		}
1318 
1319 		hash_start = (char*)eth_data->h_dest;
1320 		hash_size = ETH_ALEN;
1321 		break;
1322 	case ETH_P_ARP:
1323 		do_tx_balance = 0;
1324 		if (bond_info->rlb_enabled) {
1325 			tx_slave = rlb_arp_xmit(skb, bond);
1326 		}
1327 		break;
1328 	default:
1329 		do_tx_balance = 0;
1330 		break;
1331 	}
1332 
1333 	if (do_tx_balance) {
1334 		hash_index = _simple_hash(hash_start, hash_size);
1335 		tx_slave = tlb_choose_channel(bond, hash_index, skb->len);
1336 	}
1337 
1338 	if (!tx_slave) {
1339 		/* unbalanced or unassigned, send through primary */
1340 		tx_slave = bond->curr_active_slave;
1341 		bond_info->unbalanced_load += skb->len;
1342 	}
1343 
1344 	if (tx_slave && SLAVE_IS_OK(tx_slave)) {
1345 		if (tx_slave != bond->curr_active_slave) {
1346 			memcpy(eth_data->h_source,
1347 			       tx_slave->dev->dev_addr,
1348 			       ETH_ALEN);
1349 		}
1350 
1351 		res = bond_dev_queue_xmit(bond, skb, tx_slave->dev);
1352 	} else {
1353 		if (tx_slave) {
1354 			tlb_clear_slave(bond, tx_slave, 0);
1355 		}
1356 	}
1357 
1358 out:
1359 	if (res) {
1360 		/* no suitable interface, frame not sent */
1361 		dev_kfree_skb(skb);
1362 	}
1363 	read_unlock(&bond->curr_slave_lock);
1364 	read_unlock(&bond->lock);
1365 	return 0;
1366 }
1367 
1368 void bond_alb_monitor(struct bonding *bond)
1369 {
1370 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1371 	struct slave *slave;
1372 	int i;
1373 
1374 	read_lock(&bond->lock);
1375 
1376 	if (bond->kill_timers) {
1377 		goto out;
1378 	}
1379 
1380 	if (bond->slave_cnt == 0) {
1381 		bond_info->tx_rebalance_counter = 0;
1382 		bond_info->lp_counter = 0;
1383 		goto re_arm;
1384 	}
1385 
1386 	bond_info->tx_rebalance_counter++;
1387 	bond_info->lp_counter++;
1388 
1389 	/* send learning packets */
1390 	if (bond_info->lp_counter >= BOND_ALB_LP_TICKS) {
1391 		/* change of curr_active_slave involves swapping of mac addresses.
1392 		 * in order to avoid this swapping from happening while
1393 		 * sending the learning packets, the curr_slave_lock must be held for
1394 		 * read.
1395 		 */
1396 		read_lock(&bond->curr_slave_lock);
1397 
1398 		bond_for_each_slave(bond, slave, i) {
1399 			alb_send_learning_packets(slave, slave->dev->dev_addr);
1400 		}
1401 
1402 		read_unlock(&bond->curr_slave_lock);
1403 
1404 		bond_info->lp_counter = 0;
1405 	}
1406 
1407 	/* rebalance tx traffic */
1408 	if (bond_info->tx_rebalance_counter >= BOND_TLB_REBALANCE_TICKS) {
1409 
1410 		read_lock(&bond->curr_slave_lock);
1411 
1412 		bond_for_each_slave(bond, slave, i) {
1413 			tlb_clear_slave(bond, slave, 1);
1414 			if (slave == bond->curr_active_slave) {
1415 				SLAVE_TLB_INFO(slave).load =
1416 					bond_info->unbalanced_load /
1417 						BOND_TLB_REBALANCE_INTERVAL;
1418 				bond_info->unbalanced_load = 0;
1419 			}
1420 		}
1421 
1422 		read_unlock(&bond->curr_slave_lock);
1423 
1424 		bond_info->tx_rebalance_counter = 0;
1425 	}
1426 
1427 	/* handle rlb stuff */
1428 	if (bond_info->rlb_enabled) {
1429 		/* the following code changes the promiscuity of the
1430 		 * the curr_active_slave. It needs to be locked with a
1431 		 * write lock to protect from other code that also
1432 		 * sets the promiscuity.
1433 		 */
1434 		write_lock_bh(&bond->curr_slave_lock);
1435 
1436 		if (bond_info->primary_is_promisc &&
1437 		    (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {
1438 
1439 			bond_info->rlb_promisc_timeout_counter = 0;
1440 
1441 			/* If the primary was set to promiscuous mode
1442 			 * because a slave was disabled then
1443 			 * it can now leave promiscuous mode.
1444 			 */
1445 			dev_set_promiscuity(bond->curr_active_slave->dev, -1);
1446 			bond_info->primary_is_promisc = 0;
1447 		}
1448 
1449 		write_unlock_bh(&bond->curr_slave_lock);
1450 
1451 		if (bond_info->rlb_rebalance) {
1452 			bond_info->rlb_rebalance = 0;
1453 			rlb_rebalance(bond);
1454 		}
1455 
1456 		/* check if clients need updating */
1457 		if (bond_info->rx_ntt) {
1458 			if (bond_info->rlb_update_delay_counter) {
1459 				--bond_info->rlb_update_delay_counter;
1460 			} else {
1461 				rlb_update_rx_clients(bond);
1462 				if (bond_info->rlb_update_retry_counter) {
1463 					--bond_info->rlb_update_retry_counter;
1464 				} else {
1465 					bond_info->rx_ntt = 0;
1466 				}
1467 			}
1468 		}
1469 	}
1470 
1471 re_arm:
1472 	mod_timer(&(bond_info->alb_timer), jiffies + alb_delta_in_ticks);
1473 out:
1474 	read_unlock(&bond->lock);
1475 }
1476 
1477 /* assumption: called before the slave is attached to the bond
1478  * and not locked by the bond lock
1479  */
1480 int bond_alb_init_slave(struct bonding *bond, struct slave *slave)
1481 {
1482 	int res;
1483 
1484 	res = alb_set_slave_mac_addr(slave, slave->perm_hwaddr,
1485 				     bond->alb_info.rlb_enabled);
1486 	if (res) {
1487 		return res;
1488 	}
1489 
1490 	/* caller must hold the bond lock for write since the mac addresses
1491 	 * are compared and may be swapped.
1492 	 */
1493 	write_lock_bh(&bond->lock);
1494 
1495 	res = alb_handle_addr_collision_on_attach(bond, slave);
1496 
1497 	write_unlock_bh(&bond->lock);
1498 
1499 	if (res) {
1500 		return res;
1501 	}
1502 
1503 	tlb_init_slave(slave);
1504 
1505 	/* order a rebalance ASAP */
1506 	bond->alb_info.tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1507 
1508 	if (bond->alb_info.rlb_enabled) {
1509 		bond->alb_info.rlb_rebalance = 1;
1510 	}
1511 
1512 	return 0;
1513 }
1514 
1515 /* Caller must hold bond lock for write */
1516 void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
1517 {
1518 	if (bond->slave_cnt > 1) {
1519 		alb_change_hw_addr_on_detach(bond, slave);
1520 	}
1521 
1522 	tlb_clear_slave(bond, slave, 0);
1523 
1524 	if (bond->alb_info.rlb_enabled) {
1525 		bond->alb_info.next_rx_slave = NULL;
1526 		rlb_clear_slave(bond, slave);
1527 	}
1528 }
1529 
1530 /* Caller must hold bond lock for read */
1531 void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link)
1532 {
1533 	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1534 
1535 	if (link == BOND_LINK_DOWN) {
1536 		tlb_clear_slave(bond, slave, 0);
1537 		if (bond->alb_info.rlb_enabled) {
1538 			rlb_clear_slave(bond, slave);
1539 		}
1540 	} else if (link == BOND_LINK_UP) {
1541 		/* order a rebalance ASAP */
1542 		bond_info->tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1543 		if (bond->alb_info.rlb_enabled) {
1544 			bond->alb_info.rlb_rebalance = 1;
1545 			/* If the updelay module parameter is smaller than the
1546 			 * forwarding delay of the switch the rebalance will
1547 			 * not work because the rebalance arp replies will
1548 			 * not be forwarded to the clients..
1549 			 */
1550 		}
1551 	}
1552 }
1553 
1554 /**
1555  * bond_alb_handle_active_change - assign new curr_active_slave
1556  * @bond: our bonding struct
1557  * @new_slave: new slave to assign
1558  *
1559  * Set the bond->curr_active_slave to @new_slave and handle
1560  * mac address swapping and promiscuity changes as needed.
1561  *
1562  * Caller must hold bond curr_slave_lock for write (or bond lock for write)
1563  */
1564 void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
1565 {
1566 	struct slave *swap_slave;
1567 	int i;
1568 
1569 	if (bond->curr_active_slave == new_slave) {
1570 		return;
1571 	}
1572 
1573 	if (bond->curr_active_slave && bond->alb_info.primary_is_promisc) {
1574 		dev_set_promiscuity(bond->curr_active_slave->dev, -1);
1575 		bond->alb_info.primary_is_promisc = 0;
1576 		bond->alb_info.rlb_promisc_timeout_counter = 0;
1577 	}
1578 
1579 	swap_slave = bond->curr_active_slave;
1580 	bond->curr_active_slave = new_slave;
1581 
1582 	if (!new_slave || (bond->slave_cnt == 0)) {
1583 		return;
1584 	}
1585 
1586 	/* set the new curr_active_slave to the bonds mac address
1587 	 * i.e. swap mac addresses of old curr_active_slave and new curr_active_slave
1588 	 */
1589 	if (!swap_slave) {
1590 		struct slave *tmp_slave;
1591 		/* find slave that is holding the bond's mac address */
1592 		bond_for_each_slave(bond, tmp_slave, i) {
1593 			if (!memcmp(tmp_slave->dev->dev_addr,
1594 				    bond->dev->dev_addr, ETH_ALEN)) {
1595 				swap_slave = tmp_slave;
1596 				break;
1597 			}
1598 		}
1599 	}
1600 
1601 	/* curr_active_slave must be set before calling alb_swap_mac_addr */
1602 	if (swap_slave) {
1603 		/* swap mac address */
1604 		alb_swap_mac_addr(bond, swap_slave, new_slave);
1605 	} else {
1606 		/* set the new_slave to the bond mac address */
1607 		alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr,
1608 				       bond->alb_info.rlb_enabled);
1609 		/* fasten bond mac on new current slave */
1610 		alb_send_learning_packets(new_slave, bond->dev->dev_addr);
1611 	}
1612 }
1613 
1614 int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
1615 {
1616 	struct bonding *bond = bond_dev->priv;
1617 	struct sockaddr *sa = addr;
1618 	struct slave *slave, *swap_slave;
1619 	int res;
1620 	int i;
1621 
1622 	if (!is_valid_ether_addr(sa->sa_data)) {
1623 		return -EADDRNOTAVAIL;
1624 	}
1625 
1626 	res = alb_set_mac_address(bond, addr);
1627 	if (res) {
1628 		return res;
1629 	}
1630 
1631 	memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);
1632 
1633 	/* If there is no curr_active_slave there is nothing else to do.
1634 	 * Otherwise we'll need to pass the new address to it and handle
1635 	 * duplications.
1636 	 */
1637 	if (!bond->curr_active_slave) {
1638 		return 0;
1639 	}
1640 
1641 	swap_slave = NULL;
1642 
1643 	bond_for_each_slave(bond, slave, i) {
1644 		if (!memcmp(slave->dev->dev_addr, bond_dev->dev_addr, ETH_ALEN)) {
1645 			swap_slave = slave;
1646 			break;
1647 		}
1648 	}
1649 
1650 	if (swap_slave) {
1651 		alb_swap_mac_addr(bond, swap_slave, bond->curr_active_slave);
1652 	} else {
1653 		alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr,
1654 				       bond->alb_info.rlb_enabled);
1655 
1656 		alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
1657 		if (bond->alb_info.rlb_enabled) {
1658 			/* inform clients mac address has changed */
1659 			rlb_req_update_slave_clients(bond, bond->curr_active_slave);
1660 		}
1661 	}
1662 
1663 	return 0;
1664 }
1665 
1666 void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
1667 {
1668 	if (bond->alb_info.current_alb_vlan &&
1669 	    (bond->alb_info.current_alb_vlan->vlan_id == vlan_id)) {
1670 		bond->alb_info.current_alb_vlan = NULL;
1671 	}
1672 
1673 	if (bond->alb_info.rlb_enabled) {
1674 		rlb_clear_vlan(bond, vlan_id);
1675 	}
1676 }
1677 
1678