blob: 554a8256816027bbbeb60c16db62ff6a4e44de29 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
/*
* Round robin policy for multipath.
*
*
* Version: $Id: multipath_rr.c,v 1.1.2.2 2004/09/16 07:42:34 elueck Exp $
*
* Authors: Einar Lueck <elueck@de.ibm.com><lkml@einar-lueck.de>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/mroute.h>
#include <linux/init.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/raw.h>
#include <linux/notifier.h>
#include <linux/if_arp.h>
#include <linux/netfilter_ipv4.h>
#include <net/ipip.h>
#include <net/checksum.h>
#include <net/ip_mp_alg.h>
#define MULTIPATH_MAX_CANDIDATES 40
static struct rtable* last_used = NULL;
static void rr_remove(struct rtable *rt)
{
if (last_used == rt)
last_used = NULL;
}
static void rr_select_route(const struct flowi *flp,
struct rtable *first, struct rtable **rp)
{
struct rtable *nh, *result, *min_use_cand = NULL;
int min_use = -1;
/* if necessary and possible utilize the old alternative */
if ((flp->flags & FLOWI_FLAG_MULTIPATHOLDROUTE) != 0 &&
last_used != NULL) {
result = last_used;
goto out;
}
/* 1. make sure all alt. nexthops have the same GC related data
* 2. determine the new candidate to be returned
*/
result = NULL;
for (nh = rcu_dereference(first); nh;
nh = rcu_dereference(nh->u.rt_next)) {
if ((nh->u.dst.flags & DST_BALANCED) != 0 &&
multipath_comparekeys(&nh->fl, flp)) {
nh->u.dst.lastuse = jiffies;
if (min_use == -1 || nh->u.dst.__use < min_use) {
min_use = nh->u.dst.__use;
min_use_cand = nh;
}
}
}
result = min_use_cand;
if (!result)
result = first;
out:
last_used = result;
result->u.dst.__use++;
*rp = result;
}
static struct ip_mp_alg_ops rr_ops = {
.mp_alg_select_route = rr_select_route,
.mp_alg_remove = rr_remove,
};
static int __init rr_init(void)
{
return multipath_alg_register(&rr_ops, IP_MP_ALG_RR);
}
static void __exit rr_exit(void)
{
multipath_alg_unregister(&rr_ops, IP_MP_ALG_RR);
}
module_init(rr_init);
module_exit(rr_exit);
|
