From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/net/netfilter/ipvs/ip_vs_sh.c | 385 +++++++++++++++++++++++++++++++++++ 1 file changed, 385 insertions(+) create mode 100644 kernel/net/netfilter/ipvs/ip_vs_sh.c (limited to 'kernel/net/netfilter/ipvs/ip_vs_sh.c') diff --git a/kernel/net/netfilter/ipvs/ip_vs_sh.c b/kernel/net/netfilter/ipvs/ip_vs_sh.c new file mode 100644 index 000000000..98a13433b --- /dev/null +++ b/kernel/net/netfilter/ipvs/ip_vs_sh.c @@ -0,0 +1,385 @@ +/* + * IPVS: Source Hashing scheduling module + * + * Authors: Wensong Zhang + * + * 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. + * + * Changes: + * + */ + +/* + * The sh algorithm is to select server by the hash key of source IP + * address. The pseudo code is as follows: + * + * n <- servernode[src_ip]; + * if (n is dead) OR + * (n is overloaded) or (n.weight <= 0) then + * return NULL; + * + * return n; + * + * Notes that servernode is a 256-bucket hash table that maps the hash + * index derived from packet source IP address to the current server + * array. If the sh scheduler is used in cache cluster, it is good to + * combine it with cache_bypass feature. When the statically assigned + * server is dead or overloaded, the load balancer can bypass the cache + * server and send requests to the original server directly. + * + * The weight destination attribute can be used to control the + * distribution of connections to the destinations in servernode. The + * greater the weight, the more connections the destination + * will receive. + * + */ + +#define KMSG_COMPONENT "IPVS" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include +#include +#include +#include +#include + +#include + +#include +#include +#include + + +/* + * IPVS SH bucket + */ +struct ip_vs_sh_bucket { + struct ip_vs_dest __rcu *dest; /* real server (cache) */ +}; + +/* + * for IPVS SH entry hash table + */ +#ifndef CONFIG_IP_VS_SH_TAB_BITS +#define CONFIG_IP_VS_SH_TAB_BITS 8 +#endif +#define IP_VS_SH_TAB_BITS CONFIG_IP_VS_SH_TAB_BITS +#define IP_VS_SH_TAB_SIZE (1 << IP_VS_SH_TAB_BITS) +#define IP_VS_SH_TAB_MASK (IP_VS_SH_TAB_SIZE - 1) + +struct ip_vs_sh_state { + struct rcu_head rcu_head; + struct ip_vs_sh_bucket buckets[IP_VS_SH_TAB_SIZE]; +}; + +/* Helper function to determine if server is unavailable */ +static inline bool is_unavailable(struct ip_vs_dest *dest) +{ + return atomic_read(&dest->weight) <= 0 || + dest->flags & IP_VS_DEST_F_OVERLOAD; +} + +/* + * Returns hash value for IPVS SH entry + */ +static inline unsigned int +ip_vs_sh_hashkey(int af, const union nf_inet_addr *addr, + __be16 port, unsigned int offset) +{ + __be32 addr_fold = addr->ip; + +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6) + addr_fold = addr->ip6[0]^addr->ip6[1]^ + addr->ip6[2]^addr->ip6[3]; +#endif + return (offset + (ntohs(port) + ntohl(addr_fold))*2654435761UL) & + IP_VS_SH_TAB_MASK; +} + + +/* + * Get ip_vs_dest associated with supplied parameters. + */ +static inline struct ip_vs_dest * +ip_vs_sh_get(struct ip_vs_service *svc, struct ip_vs_sh_state *s, + const union nf_inet_addr *addr, __be16 port) +{ + unsigned int hash = ip_vs_sh_hashkey(svc->af, addr, port, 0); + struct ip_vs_dest *dest = rcu_dereference(s->buckets[hash].dest); + + return (!dest || is_unavailable(dest)) ? NULL : dest; +} + + +/* As ip_vs_sh_get, but with fallback if selected server is unavailable + * + * The fallback strategy loops around the table starting from a "random" + * point (in fact, it is chosen to be the original hash value to make the + * algorithm deterministic) to find a new server. + */ +static inline struct ip_vs_dest * +ip_vs_sh_get_fallback(struct ip_vs_service *svc, struct ip_vs_sh_state *s, + const union nf_inet_addr *addr, __be16 port) +{ + unsigned int offset, roffset; + unsigned int hash, ihash; + struct ip_vs_dest *dest; + + /* first try the dest it's supposed to go to */ + ihash = ip_vs_sh_hashkey(svc->af, addr, port, 0); + dest = rcu_dereference(s->buckets[ihash].dest); + if (!dest) + return NULL; + if (!is_unavailable(dest)) + return dest; + + IP_VS_DBG_BUF(6, "SH: selected unavailable server %s:%d, reselecting", + IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port)); + + /* if the original dest is unavailable, loop around the table + * starting from ihash to find a new dest + */ + for (offset = 0; offset < IP_VS_SH_TAB_SIZE; offset++) { + roffset = (offset + ihash) % IP_VS_SH_TAB_SIZE; + hash = ip_vs_sh_hashkey(svc->af, addr, port, roffset); + dest = rcu_dereference(s->buckets[hash].dest); + if (!dest) + break; + if (!is_unavailable(dest)) + return dest; + IP_VS_DBG_BUF(6, "SH: selected unavailable " + "server %s:%d (offset %d), reselecting", + IP_VS_DBG_ADDR(dest->af, &dest->addr), + ntohs(dest->port), roffset); + } + + return NULL; +} + +/* + * Assign all the hash buckets of the specified table with the service. + */ +static int +ip_vs_sh_reassign(struct ip_vs_sh_state *s, struct ip_vs_service *svc) +{ + int i; + struct ip_vs_sh_bucket *b; + struct list_head *p; + struct ip_vs_dest *dest; + int d_count; + bool empty; + + b = &s->buckets[0]; + p = &svc->destinations; + empty = list_empty(p); + d_count = 0; + for (i=0; idest, 1); + if (dest) + ip_vs_dest_put(dest); + if (empty) + RCU_INIT_POINTER(b->dest, NULL); + else { + if (p == &svc->destinations) + p = p->next; + + dest = list_entry(p, struct ip_vs_dest, n_list); + ip_vs_dest_hold(dest); + RCU_INIT_POINTER(b->dest, dest); + + IP_VS_DBG_BUF(6, "assigned i: %d dest: %s weight: %d\n", + i, IP_VS_DBG_ADDR(dest->af, &dest->addr), + atomic_read(&dest->weight)); + + /* Don't move to next dest until filling weight */ + if (++d_count >= atomic_read(&dest->weight)) { + p = p->next; + d_count = 0; + } + + } + b++; + } + return 0; +} + + +/* + * Flush all the hash buckets of the specified table. + */ +static void ip_vs_sh_flush(struct ip_vs_sh_state *s) +{ + int i; + struct ip_vs_sh_bucket *b; + struct ip_vs_dest *dest; + + b = &s->buckets[0]; + for (i=0; idest, 1); + if (dest) { + ip_vs_dest_put(dest); + RCU_INIT_POINTER(b->dest, NULL); + } + b++; + } +} + + +static int ip_vs_sh_init_svc(struct ip_vs_service *svc) +{ + struct ip_vs_sh_state *s; + + /* allocate the SH table for this service */ + s = kzalloc(sizeof(struct ip_vs_sh_state), GFP_KERNEL); + if (s == NULL) + return -ENOMEM; + + svc->sched_data = s; + IP_VS_DBG(6, "SH hash table (memory=%Zdbytes) allocated for " + "current service\n", + sizeof(struct ip_vs_sh_bucket)*IP_VS_SH_TAB_SIZE); + + /* assign the hash buckets with current dests */ + ip_vs_sh_reassign(s, svc); + + return 0; +} + + +static void ip_vs_sh_done_svc(struct ip_vs_service *svc) +{ + struct ip_vs_sh_state *s = svc->sched_data; + + /* got to clean up hash buckets here */ + ip_vs_sh_flush(s); + + /* release the table itself */ + kfree_rcu(s, rcu_head); + IP_VS_DBG(6, "SH hash table (memory=%Zdbytes) released\n", + sizeof(struct ip_vs_sh_bucket)*IP_VS_SH_TAB_SIZE); +} + + +static int ip_vs_sh_dest_changed(struct ip_vs_service *svc, + struct ip_vs_dest *dest) +{ + struct ip_vs_sh_state *s = svc->sched_data; + + /* assign the hash buckets with the updated service */ + ip_vs_sh_reassign(s, svc); + + return 0; +} + + +/* Helper function to get port number */ +static inline __be16 +ip_vs_sh_get_port(const struct sk_buff *skb, struct ip_vs_iphdr *iph) +{ + __be16 port; + struct tcphdr _tcph, *th; + struct udphdr _udph, *uh; + sctp_sctphdr_t _sctph, *sh; + + switch (iph->protocol) { + case IPPROTO_TCP: + th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph); + if (unlikely(th == NULL)) + return 0; + port = th->source; + break; + case IPPROTO_UDP: + uh = skb_header_pointer(skb, iph->len, sizeof(_udph), &_udph); + if (unlikely(uh == NULL)) + return 0; + port = uh->source; + break; + case IPPROTO_SCTP: + sh = skb_header_pointer(skb, iph->len, sizeof(_sctph), &_sctph); + if (unlikely(sh == NULL)) + return 0; + port = sh->source; + break; + default: + port = 0; + } + + return port; +} + + +/* + * Source Hashing scheduling + */ +static struct ip_vs_dest * +ip_vs_sh_schedule(struct ip_vs_service *svc, const struct sk_buff *skb, + struct ip_vs_iphdr *iph) +{ + struct ip_vs_dest *dest; + struct ip_vs_sh_state *s; + __be16 port = 0; + + IP_VS_DBG(6, "ip_vs_sh_schedule(): Scheduling...\n"); + + if (svc->flags & IP_VS_SVC_F_SCHED_SH_PORT) + port = ip_vs_sh_get_port(skb, iph); + + s = (struct ip_vs_sh_state *) svc->sched_data; + + if (svc->flags & IP_VS_SVC_F_SCHED_SH_FALLBACK) + dest = ip_vs_sh_get_fallback(svc, s, &iph->saddr, port); + else + dest = ip_vs_sh_get(svc, s, &iph->saddr, port); + + if (!dest) { + ip_vs_scheduler_err(svc, "no destination available"); + return NULL; + } + + IP_VS_DBG_BUF(6, "SH: source IP address %s --> server %s:%d\n", + IP_VS_DBG_ADDR(svc->af, &iph->saddr), + IP_VS_DBG_ADDR(dest->af, &dest->addr), + ntohs(dest->port)); + + return dest; +} + + +/* + * IPVS SH Scheduler structure + */ +static struct ip_vs_scheduler ip_vs_sh_scheduler = +{ + .name = "sh", + .refcnt = ATOMIC_INIT(0), + .module = THIS_MODULE, + .n_list = LIST_HEAD_INIT(ip_vs_sh_scheduler.n_list), + .init_service = ip_vs_sh_init_svc, + .done_service = ip_vs_sh_done_svc, + .add_dest = ip_vs_sh_dest_changed, + .del_dest = ip_vs_sh_dest_changed, + .upd_dest = ip_vs_sh_dest_changed, + .schedule = ip_vs_sh_schedule, +}; + + +static int __init ip_vs_sh_init(void) +{ + return register_ip_vs_scheduler(&ip_vs_sh_scheduler); +} + + +static void __exit ip_vs_sh_cleanup(void) +{ + unregister_ip_vs_scheduler(&ip_vs_sh_scheduler); + synchronize_rcu(); +} + + +module_init(ip_vs_sh_init); +module_exit(ip_vs_sh_cleanup); +MODULE_LICENSE("GPL"); -- cgit 1.2.3-korg