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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv4/multipath_rr.c | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
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.c | 115 |
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 @@ +/* + * 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); |