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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv4/multipath_rr.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/ipv4/multipath_rr.c')
-rw-r--r--net/ipv4/multipath_rr.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/net/ipv4/multipath_rr.c b/net/ipv4/multipath_rr.c
new file mode 100644
index 000000000000..554a82568160
--- /dev/null
+++ b/net/ipv4/multipath_rr.c
@@ -0,0 +1,115 @@
1/*
2 * Round robin policy for multipath.
3 *
4 *
5 * Version: $Id: multipath_rr.c,v 1.1.2.2 2004/09/16 07:42:34 elueck Exp $
6 *
7 * Authors: Einar Lueck <elueck@de.ibm.com><lkml@einar-lueck.de>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
15#include <linux/config.h>
16#include <asm/system.h>
17#include <asm/uaccess.h>
18#include <linux/types.h>
19#include <linux/sched.h>
20#include <linux/errno.h>
21#include <linux/timer.h>
22#include <linux/mm.h>
23#include <linux/kernel.h>
24#include <linux/fcntl.h>
25#include <linux/stat.h>
26#include <linux/socket.h>
27#include <linux/in.h>
28#include <linux/inet.h>
29#include <linux/netdevice.h>
30#include <linux/inetdevice.h>
31#include <linux/igmp.h>
32#include <linux/proc_fs.h>
33#include <linux/seq_file.h>
34#include <linux/mroute.h>
35#include <linux/init.h>
36#include <net/ip.h>
37#include <net/protocol.h>
38#include <linux/skbuff.h>
39#include <net/sock.h>
40#include <net/icmp.h>
41#include <net/udp.h>
42#include <net/raw.h>
43#include <linux/notifier.h>
44#include <linux/if_arp.h>
45#include <linux/netfilter_ipv4.h>
46#include <net/ipip.h>
47#include <net/checksum.h>
48#include <net/ip_mp_alg.h>
49
50#define MULTIPATH_MAX_CANDIDATES 40
51
52static struct rtable* last_used = NULL;
53
54static void rr_remove(struct rtable *rt)
55{
56 if (last_used == rt)
57 last_used = NULL;
58}
59
60static void rr_select_route(const struct flowi *flp,
61 struct rtable *first, struct rtable **rp)
62{
63 struct rtable *nh, *result, *min_use_cand = NULL;
64 int min_use = -1;
65
66 /* if necessary and possible utilize the old alternative */
67 if ((flp->flags & FLOWI_FLAG_MULTIPATHOLDROUTE) != 0 &&
68 last_used != NULL) {
69 result = last_used;
70 goto out;
71 }
72
73 /* 1. make sure all alt. nexthops have the same GC related data
74 * 2. determine the new candidate to be returned
75 */
76 result = NULL;
77 for (nh = rcu_dereference(first); nh;
78 nh = rcu_dereference(nh->u.rt_next)) {
79 if ((nh->u.dst.flags & DST_BALANCED) != 0 &&
80 multipath_comparekeys(&nh->fl, flp)) {
81 nh->u.dst.lastuse = jiffies;
82
83 if (min_use == -1 || nh->u.dst.__use < min_use) {
84 min_use = nh->u.dst.__use;
85 min_use_cand = nh;
86 }
87 }
88 }
89 result = min_use_cand;
90 if (!result)
91 result = first;
92
93out:
94 last_used = result;
95 result->u.dst.__use++;
96 *rp = result;
97}
98
99static struct ip_mp_alg_ops rr_ops = {
100 .mp_alg_select_route = rr_select_route,
101 .mp_alg_remove = rr_remove,
102};
103
104static int __init rr_init(void)
105{
106 return multipath_alg_register(&rr_ops, IP_MP_ALG_RR);
107}
108
109static void __exit rr_exit(void)
110{
111 multipath_alg_unregister(&rr_ops, IP_MP_ALG_RR);
112}
113
114module_init(rr_init);
115module_exit(rr_exit);