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![Patrick McHardy](/assets/img/avatar_default.png)
okfn should only be used from different contexts to avoid deep call chains, i.e. by nf_queue. Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
1188 lines
30 KiB
C
1188 lines
30 KiB
C
/*
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* IPVS An implementation of the IP virtual server support for the
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* LINUX operating system. IPVS is now implemented as a module
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* over the Netfilter framework. IPVS can be used to build a
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* high-performance and highly available server based on a
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* cluster of servers.
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*
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* Version: $Id: ip_vs_core.c,v 1.34 2003/05/10 03:05:23 wensong Exp $
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*
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* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
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* Peter Kese <peter.kese@ijs.si>
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* Julian Anastasov <ja@ssi.bg>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese,
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* with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms
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* and others.
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*
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* Changes:
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* Paul `Rusty' Russell properly handle non-linear skbs
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* Harald Welte don't use nfcache
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/ip.h>
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#include <linux/tcp.h>
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#include <linux/icmp.h>
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#include <net/ip.h>
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#include <net/tcp.h>
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#include <net/udp.h>
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#include <net/icmp.h> /* for icmp_send */
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#include <net/route.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv4.h>
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#include <net/ip_vs.h>
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EXPORT_SYMBOL(register_ip_vs_scheduler);
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EXPORT_SYMBOL(unregister_ip_vs_scheduler);
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EXPORT_SYMBOL(ip_vs_skb_replace);
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EXPORT_SYMBOL(ip_vs_proto_name);
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EXPORT_SYMBOL(ip_vs_conn_new);
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EXPORT_SYMBOL(ip_vs_conn_in_get);
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EXPORT_SYMBOL(ip_vs_conn_out_get);
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#ifdef CONFIG_IP_VS_PROTO_TCP
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EXPORT_SYMBOL(ip_vs_tcp_conn_listen);
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#endif
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EXPORT_SYMBOL(ip_vs_conn_put);
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#ifdef CONFIG_IP_VS_DEBUG
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EXPORT_SYMBOL(ip_vs_get_debug_level);
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#endif
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EXPORT_SYMBOL(ip_vs_make_skb_writable);
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/* ID used in ICMP lookups */
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#define icmp_id(icmph) (((icmph)->un).echo.id)
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const char *ip_vs_proto_name(unsigned proto)
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{
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static char buf[20];
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switch (proto) {
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case IPPROTO_IP:
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return "IP";
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case IPPROTO_UDP:
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return "UDP";
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case IPPROTO_TCP:
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return "TCP";
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case IPPROTO_ICMP:
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return "ICMP";
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default:
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sprintf(buf, "IP_%d", proto);
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return buf;
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}
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}
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void ip_vs_init_hash_table(struct list_head *table, int rows)
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{
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while (--rows >= 0)
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INIT_LIST_HEAD(&table[rows]);
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}
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static inline void
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ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
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{
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struct ip_vs_dest *dest = cp->dest;
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if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
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spin_lock(&dest->stats.lock);
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dest->stats.inpkts++;
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dest->stats.inbytes += skb->len;
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spin_unlock(&dest->stats.lock);
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spin_lock(&dest->svc->stats.lock);
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dest->svc->stats.inpkts++;
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dest->svc->stats.inbytes += skb->len;
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spin_unlock(&dest->svc->stats.lock);
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spin_lock(&ip_vs_stats.lock);
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ip_vs_stats.inpkts++;
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ip_vs_stats.inbytes += skb->len;
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spin_unlock(&ip_vs_stats.lock);
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}
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}
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static inline void
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ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
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{
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struct ip_vs_dest *dest = cp->dest;
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if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
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spin_lock(&dest->stats.lock);
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dest->stats.outpkts++;
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dest->stats.outbytes += skb->len;
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spin_unlock(&dest->stats.lock);
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spin_lock(&dest->svc->stats.lock);
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dest->svc->stats.outpkts++;
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dest->svc->stats.outbytes += skb->len;
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spin_unlock(&dest->svc->stats.lock);
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spin_lock(&ip_vs_stats.lock);
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ip_vs_stats.outpkts++;
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ip_vs_stats.outbytes += skb->len;
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spin_unlock(&ip_vs_stats.lock);
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}
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}
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static inline void
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ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
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{
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spin_lock(&cp->dest->stats.lock);
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cp->dest->stats.conns++;
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spin_unlock(&cp->dest->stats.lock);
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spin_lock(&svc->stats.lock);
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svc->stats.conns++;
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spin_unlock(&svc->stats.lock);
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spin_lock(&ip_vs_stats.lock);
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ip_vs_stats.conns++;
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spin_unlock(&ip_vs_stats.lock);
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}
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static inline int
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ip_vs_set_state(struct ip_vs_conn *cp, int direction,
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const struct sk_buff *skb,
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struct ip_vs_protocol *pp)
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{
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if (unlikely(!pp->state_transition))
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return 0;
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return pp->state_transition(cp, direction, skb, pp);
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}
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int ip_vs_make_skb_writable(struct sk_buff **pskb, int writable_len)
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{
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struct sk_buff *skb = *pskb;
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/* skb is already used, better copy skb and its payload */
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if (unlikely(skb_shared(skb) || skb->sk))
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goto copy_skb;
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/* skb data is already used, copy it */
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if (unlikely(skb_cloned(skb)))
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goto copy_data;
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return pskb_may_pull(skb, writable_len);
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copy_data:
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if (unlikely(writable_len > skb->len))
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return 0;
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return !pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
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copy_skb:
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if (unlikely(writable_len > skb->len))
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return 0;
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skb = skb_copy(skb, GFP_ATOMIC);
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if (!skb)
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return 0;
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BUG_ON(skb_is_nonlinear(skb));
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/* Rest of kernel will get very unhappy if we pass it a
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suddenly-orphaned skbuff */
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if ((*pskb)->sk)
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skb_set_owner_w(skb, (*pskb)->sk);
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kfree_skb(*pskb);
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*pskb = skb;
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return 1;
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}
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/*
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* IPVS persistent scheduling function
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* It creates a connection entry according to its template if exists,
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* or selects a server and creates a connection entry plus a template.
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* Locking: we are svc user (svc->refcnt), so we hold all dests too
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* Protocols supported: TCP, UDP
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*/
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static struct ip_vs_conn *
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ip_vs_sched_persist(struct ip_vs_service *svc,
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const struct sk_buff *skb,
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__u16 ports[2])
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{
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struct ip_vs_conn *cp = NULL;
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struct iphdr *iph = skb->nh.iph;
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struct ip_vs_dest *dest;
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struct ip_vs_conn *ct;
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__u16 dport; /* destination port to forward */
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__u32 snet; /* source network of the client, after masking */
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/* Mask saddr with the netmask to adjust template granularity */
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snet = iph->saddr & svc->netmask;
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IP_VS_DBG(6, "p-schedule: src %u.%u.%u.%u:%u dest %u.%u.%u.%u:%u "
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"mnet %u.%u.%u.%u\n",
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NIPQUAD(iph->saddr), ntohs(ports[0]),
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NIPQUAD(iph->daddr), ntohs(ports[1]),
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NIPQUAD(snet));
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/*
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* As far as we know, FTP is a very complicated network protocol, and
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* it uses control connection and data connections. For active FTP,
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* FTP server initialize data connection to the client, its source port
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* is often 20. For passive FTP, FTP server tells the clients the port
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* that it passively listens to, and the client issues the data
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* connection. In the tunneling or direct routing mode, the load
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* balancer is on the client-to-server half of connection, the port
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* number is unknown to the load balancer. So, a conn template like
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* <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
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* service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
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* is created for other persistent services.
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*/
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if (ports[1] == svc->port) {
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/* Check if a template already exists */
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if (svc->port != FTPPORT)
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ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
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iph->daddr, ports[1]);
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else
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ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
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iph->daddr, 0);
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if (!ct || !ip_vs_check_template(ct)) {
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/*
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* No template found or the dest of the connection
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* template is not available.
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*/
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dest = svc->scheduler->schedule(svc, skb);
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if (dest == NULL) {
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IP_VS_DBG(1, "p-schedule: no dest found.\n");
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return NULL;
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}
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/*
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* Create a template like <protocol,caddr,0,
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* vaddr,vport,daddr,dport> for non-ftp service,
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* and <protocol,caddr,0,vaddr,0,daddr,0>
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* for ftp service.
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*/
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if (svc->port != FTPPORT)
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ct = ip_vs_conn_new(iph->protocol,
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snet, 0,
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iph->daddr,
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ports[1],
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dest->addr, dest->port,
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IP_VS_CONN_F_TEMPLATE,
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dest);
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else
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ct = ip_vs_conn_new(iph->protocol,
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snet, 0,
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iph->daddr, 0,
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dest->addr, 0,
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IP_VS_CONN_F_TEMPLATE,
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dest);
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if (ct == NULL)
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return NULL;
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ct->timeout = svc->timeout;
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} else {
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/* set destination with the found template */
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dest = ct->dest;
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}
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dport = dest->port;
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} else {
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/*
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* Note: persistent fwmark-based services and persistent
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* port zero service are handled here.
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* fwmark template: <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
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* port zero template: <protocol,caddr,0,vaddr,0,daddr,0>
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*/
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if (svc->fwmark)
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ct = ip_vs_ct_in_get(IPPROTO_IP, snet, 0,
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htonl(svc->fwmark), 0);
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else
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ct = ip_vs_ct_in_get(iph->protocol, snet, 0,
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iph->daddr, 0);
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if (!ct || !ip_vs_check_template(ct)) {
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/*
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* If it is not persistent port zero, return NULL,
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* otherwise create a connection template.
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*/
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if (svc->port)
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return NULL;
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dest = svc->scheduler->schedule(svc, skb);
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if (dest == NULL) {
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IP_VS_DBG(1, "p-schedule: no dest found.\n");
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return NULL;
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}
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/*
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* Create a template according to the service
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*/
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if (svc->fwmark)
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ct = ip_vs_conn_new(IPPROTO_IP,
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snet, 0,
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htonl(svc->fwmark), 0,
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dest->addr, 0,
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IP_VS_CONN_F_TEMPLATE,
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dest);
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else
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ct = ip_vs_conn_new(iph->protocol,
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snet, 0,
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iph->daddr, 0,
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dest->addr, 0,
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IP_VS_CONN_F_TEMPLATE,
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dest);
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if (ct == NULL)
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return NULL;
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ct->timeout = svc->timeout;
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} else {
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/* set destination with the found template */
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dest = ct->dest;
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}
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dport = ports[1];
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}
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/*
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* Create a new connection according to the template
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*/
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cp = ip_vs_conn_new(iph->protocol,
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iph->saddr, ports[0],
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iph->daddr, ports[1],
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dest->addr, dport,
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0,
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dest);
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if (cp == NULL) {
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ip_vs_conn_put(ct);
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return NULL;
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}
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/*
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* Add its control
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*/
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ip_vs_control_add(cp, ct);
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ip_vs_conn_put(ct);
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ip_vs_conn_stats(cp, svc);
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return cp;
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}
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/*
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* IPVS main scheduling function
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* It selects a server according to the virtual service, and
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* creates a connection entry.
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* Protocols supported: TCP, UDP
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*/
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struct ip_vs_conn *
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ip_vs_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
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{
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struct ip_vs_conn *cp = NULL;
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struct iphdr *iph = skb->nh.iph;
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struct ip_vs_dest *dest;
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__u16 _ports[2], *pptr;
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pptr = skb_header_pointer(skb, iph->ihl*4,
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sizeof(_ports), _ports);
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if (pptr == NULL)
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return NULL;
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/*
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* Persistent service
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*/
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if (svc->flags & IP_VS_SVC_F_PERSISTENT)
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return ip_vs_sched_persist(svc, skb, pptr);
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/*
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* Non-persistent service
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*/
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if (!svc->fwmark && pptr[1] != svc->port) {
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if (!svc->port)
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IP_VS_ERR("Schedule: port zero only supported "
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"in persistent services, "
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"check your ipvs configuration\n");
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return NULL;
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}
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dest = svc->scheduler->schedule(svc, skb);
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if (dest == NULL) {
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IP_VS_DBG(1, "Schedule: no dest found.\n");
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return NULL;
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}
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/*
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* Create a connection entry.
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*/
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cp = ip_vs_conn_new(iph->protocol,
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iph->saddr, pptr[0],
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iph->daddr, pptr[1],
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dest->addr, dest->port?dest->port:pptr[1],
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0,
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dest);
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if (cp == NULL)
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return NULL;
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IP_VS_DBG(6, "Schedule fwd:%c c:%u.%u.%u.%u:%u v:%u.%u.%u.%u:%u "
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"d:%u.%u.%u.%u:%u conn->flags:%X conn->refcnt:%d\n",
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ip_vs_fwd_tag(cp),
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NIPQUAD(cp->caddr), ntohs(cp->cport),
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NIPQUAD(cp->vaddr), ntohs(cp->vport),
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NIPQUAD(cp->daddr), ntohs(cp->dport),
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cp->flags, atomic_read(&cp->refcnt));
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ip_vs_conn_stats(cp, svc);
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return cp;
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}
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|
|
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/*
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* Pass or drop the packet.
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* Called by ip_vs_in, when the virtual service is available but
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* no destination is available for a new connection.
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*/
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int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
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struct ip_vs_protocol *pp)
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{
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__u16 _ports[2], *pptr;
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struct iphdr *iph = skb->nh.iph;
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pptr = skb_header_pointer(skb, iph->ihl*4,
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sizeof(_ports), _ports);
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if (pptr == NULL) {
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ip_vs_service_put(svc);
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return NF_DROP;
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}
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/* if it is fwmark-based service, the cache_bypass sysctl is up
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and the destination is RTN_UNICAST (and not local), then create
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a cache_bypass connection entry */
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if (sysctl_ip_vs_cache_bypass && svc->fwmark
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&& (inet_addr_type(iph->daddr) == RTN_UNICAST)) {
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int ret, cs;
|
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struct ip_vs_conn *cp;
|
|
|
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ip_vs_service_put(svc);
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|
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/* create a new connection entry */
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IP_VS_DBG(6, "ip_vs_leave: create a cache_bypass entry\n");
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cp = ip_vs_conn_new(iph->protocol,
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iph->saddr, pptr[0],
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iph->daddr, pptr[1],
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0, 0,
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IP_VS_CONN_F_BYPASS,
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NULL);
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if (cp == NULL)
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return NF_DROP;
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|
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/* statistics */
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ip_vs_in_stats(cp, skb);
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|
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/* set state */
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cs = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp);
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|
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/* transmit the first SYN packet */
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ret = cp->packet_xmit(skb, cp, pp);
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/* do not touch skb anymore */
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|
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atomic_inc(&cp->in_pkts);
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ip_vs_conn_put(cp);
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return ret;
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}
|
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|
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/*
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* When the virtual ftp service is presented, packets destined
|
|
* for other services on the VIP may get here (except services
|
|
* listed in the ipvs table), pass the packets, because it is
|
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* not ipvs job to decide to drop the packets.
|
|
*/
|
|
if ((svc->port == FTPPORT) && (pptr[1] != FTPPORT)) {
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ip_vs_service_put(svc);
|
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return NF_ACCEPT;
|
|
}
|
|
|
|
ip_vs_service_put(svc);
|
|
|
|
/*
|
|
* Notify the client that the destination is unreachable, and
|
|
* release the socket buffer.
|
|
* Since it is in IP layer, the TCP socket is not actually
|
|
* created, the TCP RST packet cannot be sent, instead that
|
|
* ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
|
|
*/
|
|
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
|
|
return NF_DROP;
|
|
}
|
|
|
|
|
|
/*
|
|
* It is hooked before NF_IP_PRI_NAT_SRC at the NF_IP_POST_ROUTING
|
|
* chain, and is used for VS/NAT.
|
|
* It detects packets for VS/NAT connections and sends the packets
|
|
* immediately. This can avoid that iptable_nat mangles the packets
|
|
* for VS/NAT.
|
|
*/
|
|
static unsigned int ip_vs_post_routing(unsigned int hooknum,
|
|
struct sk_buff **pskb,
|
|
const struct net_device *in,
|
|
const struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
if (!((*pskb)->ipvs_property))
|
|
return NF_ACCEPT;
|
|
/* The packet was sent from IPVS, exit this chain */
|
|
return NF_STOP;
|
|
}
|
|
|
|
u16 ip_vs_checksum_complete(struct sk_buff *skb, int offset)
|
|
{
|
|
return (u16) csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
|
|
}
|
|
|
|
static inline struct sk_buff *
|
|
ip_vs_gather_frags(struct sk_buff *skb, u_int32_t user)
|
|
{
|
|
skb = ip_defrag(skb, user);
|
|
if (skb)
|
|
ip_send_check(skb->nh.iph);
|
|
return skb;
|
|
}
|
|
|
|
/*
|
|
* Packet has been made sufficiently writable in caller
|
|
* - inout: 1=in->out, 0=out->in
|
|
*/
|
|
void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
|
|
struct ip_vs_conn *cp, int inout)
|
|
{
|
|
struct iphdr *iph = skb->nh.iph;
|
|
unsigned int icmp_offset = iph->ihl*4;
|
|
struct icmphdr *icmph = (struct icmphdr *)(skb->nh.raw + icmp_offset);
|
|
struct iphdr *ciph = (struct iphdr *)(icmph + 1);
|
|
|
|
if (inout) {
|
|
iph->saddr = cp->vaddr;
|
|
ip_send_check(iph);
|
|
ciph->daddr = cp->vaddr;
|
|
ip_send_check(ciph);
|
|
} else {
|
|
iph->daddr = cp->daddr;
|
|
ip_send_check(iph);
|
|
ciph->saddr = cp->daddr;
|
|
ip_send_check(ciph);
|
|
}
|
|
|
|
/* the TCP/UDP port */
|
|
if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol) {
|
|
__u16 *ports = (void *)ciph + ciph->ihl*4;
|
|
|
|
if (inout)
|
|
ports[1] = cp->vport;
|
|
else
|
|
ports[0] = cp->dport;
|
|
}
|
|
|
|
/* And finally the ICMP checksum */
|
|
icmph->checksum = 0;
|
|
icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset);
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
|
|
if (inout)
|
|
IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
|
|
"Forwarding altered outgoing ICMP");
|
|
else
|
|
IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
|
|
"Forwarding altered incoming ICMP");
|
|
}
|
|
|
|
/*
|
|
* Handle ICMP messages in the inside-to-outside direction (outgoing).
|
|
* Find any that might be relevant, check against existing connections,
|
|
* forward to the right destination host if relevant.
|
|
* Currently handles error types - unreachable, quench, ttl exceeded.
|
|
* (Only used in VS/NAT)
|
|
*/
|
|
static int ip_vs_out_icmp(struct sk_buff **pskb, int *related)
|
|
{
|
|
struct sk_buff *skb = *pskb;
|
|
struct iphdr *iph;
|
|
struct icmphdr _icmph, *ic;
|
|
struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */
|
|
struct ip_vs_conn *cp;
|
|
struct ip_vs_protocol *pp;
|
|
unsigned int offset, ihl, verdict;
|
|
|
|
*related = 1;
|
|
|
|
/* reassemble IP fragments */
|
|
if (skb->nh.iph->frag_off & __constant_htons(IP_MF|IP_OFFSET)) {
|
|
skb = ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT);
|
|
if (!skb)
|
|
return NF_STOLEN;
|
|
*pskb = skb;
|
|
}
|
|
|
|
iph = skb->nh.iph;
|
|
offset = ihl = iph->ihl * 4;
|
|
ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
|
|
if (ic == NULL)
|
|
return NF_DROP;
|
|
|
|
IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %u.%u.%u.%u->%u.%u.%u.%u\n",
|
|
ic->type, ntohs(icmp_id(ic)),
|
|
NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
|
|
|
|
/*
|
|
* Work through seeing if this is for us.
|
|
* These checks are supposed to be in an order that means easy
|
|
* things are checked first to speed up processing.... however
|
|
* this means that some packets will manage to get a long way
|
|
* down this stack and then be rejected, but that's life.
|
|
*/
|
|
if ((ic->type != ICMP_DEST_UNREACH) &&
|
|
(ic->type != ICMP_SOURCE_QUENCH) &&
|
|
(ic->type != ICMP_TIME_EXCEEDED)) {
|
|
*related = 0;
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
/* Now find the contained IP header */
|
|
offset += sizeof(_icmph);
|
|
cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
|
|
if (cih == NULL)
|
|
return NF_ACCEPT; /* The packet looks wrong, ignore */
|
|
|
|
pp = ip_vs_proto_get(cih->protocol);
|
|
if (!pp)
|
|
return NF_ACCEPT;
|
|
|
|
/* Is the embedded protocol header present? */
|
|
if (unlikely(cih->frag_off & __constant_htons(IP_OFFSET) &&
|
|
pp->dont_defrag))
|
|
return NF_ACCEPT;
|
|
|
|
IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMP for");
|
|
|
|
offset += cih->ihl * 4;
|
|
|
|
/* The embedded headers contain source and dest in reverse order */
|
|
cp = pp->conn_out_get(skb, pp, cih, offset, 1);
|
|
if (!cp)
|
|
return NF_ACCEPT;
|
|
|
|
verdict = NF_DROP;
|
|
|
|
if (IP_VS_FWD_METHOD(cp) != 0) {
|
|
IP_VS_ERR("shouldn't reach here, because the box is on the"
|
|
"half connection in the tun/dr module.\n");
|
|
}
|
|
|
|
/* Ensure the checksum is correct */
|
|
if (skb->ip_summed != CHECKSUM_UNNECESSARY &&
|
|
ip_vs_checksum_complete(skb, ihl)) {
|
|
/* Failed checksum! */
|
|
IP_VS_DBG(1, "Forward ICMP: failed checksum from %d.%d.%d.%d!\n",
|
|
NIPQUAD(iph->saddr));
|
|
goto out;
|
|
}
|
|
|
|
if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
|
|
offset += 2 * sizeof(__u16);
|
|
if (!ip_vs_make_skb_writable(pskb, offset))
|
|
goto out;
|
|
skb = *pskb;
|
|
|
|
ip_vs_nat_icmp(skb, pp, cp, 1);
|
|
|
|
/* do the statistics and put it back */
|
|
ip_vs_out_stats(cp, skb);
|
|
|
|
skb->ipvs_property = 1;
|
|
verdict = NF_ACCEPT;
|
|
|
|
out:
|
|
__ip_vs_conn_put(cp);
|
|
|
|
return verdict;
|
|
}
|
|
|
|
static inline int is_tcp_reset(const struct sk_buff *skb)
|
|
{
|
|
struct tcphdr _tcph, *th;
|
|
|
|
th = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
|
|
sizeof(_tcph), &_tcph);
|
|
if (th == NULL)
|
|
return 0;
|
|
return th->rst;
|
|
}
|
|
|
|
/*
|
|
* It is hooked at the NF_IP_FORWARD chain, used only for VS/NAT.
|
|
* Check if outgoing packet belongs to the established ip_vs_conn,
|
|
* rewrite addresses of the packet and send it on its way...
|
|
*/
|
|
static unsigned int
|
|
ip_vs_out(unsigned int hooknum, struct sk_buff **pskb,
|
|
const struct net_device *in, const struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
struct sk_buff *skb = *pskb;
|
|
struct iphdr *iph;
|
|
struct ip_vs_protocol *pp;
|
|
struct ip_vs_conn *cp;
|
|
int ihl;
|
|
|
|
EnterFunction(11);
|
|
|
|
if (skb->ipvs_property)
|
|
return NF_ACCEPT;
|
|
|
|
iph = skb->nh.iph;
|
|
if (unlikely(iph->protocol == IPPROTO_ICMP)) {
|
|
int related, verdict = ip_vs_out_icmp(pskb, &related);
|
|
|
|
if (related)
|
|
return verdict;
|
|
skb = *pskb;
|
|
iph = skb->nh.iph;
|
|
}
|
|
|
|
pp = ip_vs_proto_get(iph->protocol);
|
|
if (unlikely(!pp))
|
|
return NF_ACCEPT;
|
|
|
|
/* reassemble IP fragments */
|
|
if (unlikely(iph->frag_off & __constant_htons(IP_MF|IP_OFFSET) &&
|
|
!pp->dont_defrag)) {
|
|
skb = ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT);
|
|
if (!skb)
|
|
return NF_STOLEN;
|
|
iph = skb->nh.iph;
|
|
*pskb = skb;
|
|
}
|
|
|
|
ihl = iph->ihl << 2;
|
|
|
|
/*
|
|
* Check if the packet belongs to an existing entry
|
|
*/
|
|
cp = pp->conn_out_get(skb, pp, iph, ihl, 0);
|
|
|
|
if (unlikely(!cp)) {
|
|
if (sysctl_ip_vs_nat_icmp_send &&
|
|
(pp->protocol == IPPROTO_TCP ||
|
|
pp->protocol == IPPROTO_UDP)) {
|
|
__u16 _ports[2], *pptr;
|
|
|
|
pptr = skb_header_pointer(skb, ihl,
|
|
sizeof(_ports), _ports);
|
|
if (pptr == NULL)
|
|
return NF_ACCEPT; /* Not for me */
|
|
if (ip_vs_lookup_real_service(iph->protocol,
|
|
iph->saddr, pptr[0])) {
|
|
/*
|
|
* Notify the real server: there is no
|
|
* existing entry if it is not RST
|
|
* packet or not TCP packet.
|
|
*/
|
|
if (iph->protocol != IPPROTO_TCP
|
|
|| !is_tcp_reset(skb)) {
|
|
icmp_send(skb,ICMP_DEST_UNREACH,
|
|
ICMP_PORT_UNREACH, 0);
|
|
return NF_DROP;
|
|
}
|
|
}
|
|
}
|
|
IP_VS_DBG_PKT(12, pp, skb, 0,
|
|
"packet continues traversal as normal");
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
IP_VS_DBG_PKT(11, pp, skb, 0, "Outgoing packet");
|
|
|
|
if (!ip_vs_make_skb_writable(pskb, ihl))
|
|
goto drop;
|
|
|
|
/* mangle the packet */
|
|
if (pp->snat_handler && !pp->snat_handler(pskb, pp, cp))
|
|
goto drop;
|
|
skb = *pskb;
|
|
skb->nh.iph->saddr = cp->vaddr;
|
|
ip_send_check(skb->nh.iph);
|
|
|
|
IP_VS_DBG_PKT(10, pp, skb, 0, "After SNAT");
|
|
|
|
ip_vs_out_stats(cp, skb);
|
|
ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pp);
|
|
ip_vs_conn_put(cp);
|
|
|
|
skb->ipvs_property = 1;
|
|
|
|
LeaveFunction(11);
|
|
return NF_ACCEPT;
|
|
|
|
drop:
|
|
ip_vs_conn_put(cp);
|
|
kfree_skb(*pskb);
|
|
return NF_STOLEN;
|
|
}
|
|
|
|
|
|
/*
|
|
* Handle ICMP messages in the outside-to-inside direction (incoming).
|
|
* Find any that might be relevant, check against existing connections,
|
|
* forward to the right destination host if relevant.
|
|
* Currently handles error types - unreachable, quench, ttl exceeded.
|
|
*/
|
|
static int
|
|
ip_vs_in_icmp(struct sk_buff **pskb, int *related, unsigned int hooknum)
|
|
{
|
|
struct sk_buff *skb = *pskb;
|
|
struct iphdr *iph;
|
|
struct icmphdr _icmph, *ic;
|
|
struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */
|
|
struct ip_vs_conn *cp;
|
|
struct ip_vs_protocol *pp;
|
|
unsigned int offset, ihl, verdict;
|
|
|
|
*related = 1;
|
|
|
|
/* reassemble IP fragments */
|
|
if (skb->nh.iph->frag_off & __constant_htons(IP_MF|IP_OFFSET)) {
|
|
skb = ip_vs_gather_frags(skb,
|
|
hooknum == NF_IP_LOCAL_IN ?
|
|
IP_DEFRAG_VS_IN : IP_DEFRAG_VS_FWD);
|
|
if (!skb)
|
|
return NF_STOLEN;
|
|
*pskb = skb;
|
|
}
|
|
|
|
iph = skb->nh.iph;
|
|
offset = ihl = iph->ihl * 4;
|
|
ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
|
|
if (ic == NULL)
|
|
return NF_DROP;
|
|
|
|
IP_VS_DBG(12, "Incoming ICMP (%d,%d) %u.%u.%u.%u->%u.%u.%u.%u\n",
|
|
ic->type, ntohs(icmp_id(ic)),
|
|
NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
|
|
|
|
/*
|
|
* Work through seeing if this is for us.
|
|
* These checks are supposed to be in an order that means easy
|
|
* things are checked first to speed up processing.... however
|
|
* this means that some packets will manage to get a long way
|
|
* down this stack and then be rejected, but that's life.
|
|
*/
|
|
if ((ic->type != ICMP_DEST_UNREACH) &&
|
|
(ic->type != ICMP_SOURCE_QUENCH) &&
|
|
(ic->type != ICMP_TIME_EXCEEDED)) {
|
|
*related = 0;
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
/* Now find the contained IP header */
|
|
offset += sizeof(_icmph);
|
|
cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
|
|
if (cih == NULL)
|
|
return NF_ACCEPT; /* The packet looks wrong, ignore */
|
|
|
|
pp = ip_vs_proto_get(cih->protocol);
|
|
if (!pp)
|
|
return NF_ACCEPT;
|
|
|
|
/* Is the embedded protocol header present? */
|
|
if (unlikely(cih->frag_off & __constant_htons(IP_OFFSET) &&
|
|
pp->dont_defrag))
|
|
return NF_ACCEPT;
|
|
|
|
IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMP for");
|
|
|
|
offset += cih->ihl * 4;
|
|
|
|
/* The embedded headers contain source and dest in reverse order */
|
|
cp = pp->conn_in_get(skb, pp, cih, offset, 1);
|
|
if (!cp)
|
|
return NF_ACCEPT;
|
|
|
|
verdict = NF_DROP;
|
|
|
|
/* Ensure the checksum is correct */
|
|
if (skb->ip_summed != CHECKSUM_UNNECESSARY &&
|
|
ip_vs_checksum_complete(skb, ihl)) {
|
|
/* Failed checksum! */
|
|
IP_VS_DBG(1, "Incoming ICMP: failed checksum from %d.%d.%d.%d!\n",
|
|
NIPQUAD(iph->saddr));
|
|
goto out;
|
|
}
|
|
|
|
/* do the statistics and put it back */
|
|
ip_vs_in_stats(cp, skb);
|
|
if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
|
|
offset += 2 * sizeof(__u16);
|
|
verdict = ip_vs_icmp_xmit(skb, cp, pp, offset);
|
|
/* do not touch skb anymore */
|
|
|
|
out:
|
|
__ip_vs_conn_put(cp);
|
|
|
|
return verdict;
|
|
}
|
|
|
|
/*
|
|
* Check if it's for virtual services, look it up,
|
|
* and send it on its way...
|
|
*/
|
|
static unsigned int
|
|
ip_vs_in(unsigned int hooknum, struct sk_buff **pskb,
|
|
const struct net_device *in, const struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
struct sk_buff *skb = *pskb;
|
|
struct iphdr *iph;
|
|
struct ip_vs_protocol *pp;
|
|
struct ip_vs_conn *cp;
|
|
int ret, restart;
|
|
int ihl;
|
|
|
|
/*
|
|
* Big tappo: only PACKET_HOST (neither loopback nor mcasts)
|
|
* ... don't know why 1st test DOES NOT include 2nd (?)
|
|
*/
|
|
if (unlikely(skb->pkt_type != PACKET_HOST
|
|
|| skb->dev == &loopback_dev || skb->sk)) {
|
|
IP_VS_DBG(12, "packet type=%d proto=%d daddr=%d.%d.%d.%d ignored\n",
|
|
skb->pkt_type,
|
|
skb->nh.iph->protocol,
|
|
NIPQUAD(skb->nh.iph->daddr));
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
iph = skb->nh.iph;
|
|
if (unlikely(iph->protocol == IPPROTO_ICMP)) {
|
|
int related, verdict = ip_vs_in_icmp(pskb, &related, hooknum);
|
|
|
|
if (related)
|
|
return verdict;
|
|
skb = *pskb;
|
|
iph = skb->nh.iph;
|
|
}
|
|
|
|
/* Protocol supported? */
|
|
pp = ip_vs_proto_get(iph->protocol);
|
|
if (unlikely(!pp))
|
|
return NF_ACCEPT;
|
|
|
|
ihl = iph->ihl << 2;
|
|
|
|
/*
|
|
* Check if the packet belongs to an existing connection entry
|
|
*/
|
|
cp = pp->conn_in_get(skb, pp, iph, ihl, 0);
|
|
|
|
if (unlikely(!cp)) {
|
|
int v;
|
|
|
|
if (!pp->conn_schedule(skb, pp, &v, &cp))
|
|
return v;
|
|
}
|
|
|
|
if (unlikely(!cp)) {
|
|
/* sorry, all this trouble for a no-hit :) */
|
|
IP_VS_DBG_PKT(12, pp, skb, 0,
|
|
"packet continues traversal as normal");
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
IP_VS_DBG_PKT(11, pp, skb, 0, "Incoming packet");
|
|
|
|
/* Check the server status */
|
|
if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
|
|
/* the destination server is not available */
|
|
|
|
if (sysctl_ip_vs_expire_nodest_conn) {
|
|
/* try to expire the connection immediately */
|
|
ip_vs_conn_expire_now(cp);
|
|
}
|
|
/* don't restart its timer, and silently
|
|
drop the packet. */
|
|
__ip_vs_conn_put(cp);
|
|
return NF_DROP;
|
|
}
|
|
|
|
ip_vs_in_stats(cp, skb);
|
|
restart = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp);
|
|
if (cp->packet_xmit)
|
|
ret = cp->packet_xmit(skb, cp, pp);
|
|
/* do not touch skb anymore */
|
|
else {
|
|
IP_VS_DBG_RL("warning: packet_xmit is null");
|
|
ret = NF_ACCEPT;
|
|
}
|
|
|
|
/* increase its packet counter and check if it is needed
|
|
to be synchronized */
|
|
atomic_inc(&cp->in_pkts);
|
|
if ((ip_vs_sync_state & IP_VS_STATE_MASTER) &&
|
|
(cp->protocol != IPPROTO_TCP ||
|
|
cp->state == IP_VS_TCP_S_ESTABLISHED) &&
|
|
(atomic_read(&cp->in_pkts) % sysctl_ip_vs_sync_threshold[1]
|
|
== sysctl_ip_vs_sync_threshold[0]))
|
|
ip_vs_sync_conn(cp);
|
|
|
|
ip_vs_conn_put(cp);
|
|
return ret;
|
|
}
|
|
|
|
|
|
/*
|
|
* It is hooked at the NF_IP_FORWARD chain, in order to catch ICMP
|
|
* related packets destined for 0.0.0.0/0.
|
|
* When fwmark-based virtual service is used, such as transparent
|
|
* cache cluster, TCP packets can be marked and routed to ip_vs_in,
|
|
* but ICMP destined for 0.0.0.0/0 cannot not be easily marked and
|
|
* sent to ip_vs_in_icmp. So, catch them at the NF_IP_FORWARD chain
|
|
* and send them to ip_vs_in_icmp.
|
|
*/
|
|
static unsigned int
|
|
ip_vs_forward_icmp(unsigned int hooknum, struct sk_buff **pskb,
|
|
const struct net_device *in, const struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
int r;
|
|
|
|
if ((*pskb)->nh.iph->protocol != IPPROTO_ICMP)
|
|
return NF_ACCEPT;
|
|
|
|
return ip_vs_in_icmp(pskb, &r, hooknum);
|
|
}
|
|
|
|
|
|
/* After packet filtering, forward packet through VS/DR, VS/TUN,
|
|
or VS/NAT(change destination), so that filtering rules can be
|
|
applied to IPVS. */
|
|
static struct nf_hook_ops ip_vs_in_ops = {
|
|
.hook = ip_vs_in,
|
|
.owner = THIS_MODULE,
|
|
.pf = PF_INET,
|
|
.hooknum = NF_IP_LOCAL_IN,
|
|
.priority = 100,
|
|
};
|
|
|
|
/* After packet filtering, change source only for VS/NAT */
|
|
static struct nf_hook_ops ip_vs_out_ops = {
|
|
.hook = ip_vs_out,
|
|
.owner = THIS_MODULE,
|
|
.pf = PF_INET,
|
|
.hooknum = NF_IP_FORWARD,
|
|
.priority = 100,
|
|
};
|
|
|
|
/* After packet filtering (but before ip_vs_out_icmp), catch icmp
|
|
destined for 0.0.0.0/0, which is for incoming IPVS connections */
|
|
static struct nf_hook_ops ip_vs_forward_icmp_ops = {
|
|
.hook = ip_vs_forward_icmp,
|
|
.owner = THIS_MODULE,
|
|
.pf = PF_INET,
|
|
.hooknum = NF_IP_FORWARD,
|
|
.priority = 99,
|
|
};
|
|
|
|
/* Before the netfilter connection tracking, exit from POST_ROUTING */
|
|
static struct nf_hook_ops ip_vs_post_routing_ops = {
|
|
.hook = ip_vs_post_routing,
|
|
.owner = THIS_MODULE,
|
|
.pf = PF_INET,
|
|
.hooknum = NF_IP_POST_ROUTING,
|
|
.priority = NF_IP_PRI_NAT_SRC-1,
|
|
};
|
|
|
|
|
|
/*
|
|
* Initialize IP Virtual Server
|
|
*/
|
|
static int __init ip_vs_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = ip_vs_control_init();
|
|
if (ret < 0) {
|
|
IP_VS_ERR("can't setup control.\n");
|
|
goto cleanup_nothing;
|
|
}
|
|
|
|
ip_vs_protocol_init();
|
|
|
|
ret = ip_vs_app_init();
|
|
if (ret < 0) {
|
|
IP_VS_ERR("can't setup application helper.\n");
|
|
goto cleanup_protocol;
|
|
}
|
|
|
|
ret = ip_vs_conn_init();
|
|
if (ret < 0) {
|
|
IP_VS_ERR("can't setup connection table.\n");
|
|
goto cleanup_app;
|
|
}
|
|
|
|
ret = nf_register_hook(&ip_vs_in_ops);
|
|
if (ret < 0) {
|
|
IP_VS_ERR("can't register in hook.\n");
|
|
goto cleanup_conn;
|
|
}
|
|
|
|
ret = nf_register_hook(&ip_vs_out_ops);
|
|
if (ret < 0) {
|
|
IP_VS_ERR("can't register out hook.\n");
|
|
goto cleanup_inops;
|
|
}
|
|
ret = nf_register_hook(&ip_vs_post_routing_ops);
|
|
if (ret < 0) {
|
|
IP_VS_ERR("can't register post_routing hook.\n");
|
|
goto cleanup_outops;
|
|
}
|
|
ret = nf_register_hook(&ip_vs_forward_icmp_ops);
|
|
if (ret < 0) {
|
|
IP_VS_ERR("can't register forward_icmp hook.\n");
|
|
goto cleanup_postroutingops;
|
|
}
|
|
|
|
IP_VS_INFO("ipvs loaded.\n");
|
|
return ret;
|
|
|
|
cleanup_postroutingops:
|
|
nf_unregister_hook(&ip_vs_post_routing_ops);
|
|
cleanup_outops:
|
|
nf_unregister_hook(&ip_vs_out_ops);
|
|
cleanup_inops:
|
|
nf_unregister_hook(&ip_vs_in_ops);
|
|
cleanup_conn:
|
|
ip_vs_conn_cleanup();
|
|
cleanup_app:
|
|
ip_vs_app_cleanup();
|
|
cleanup_protocol:
|
|
ip_vs_protocol_cleanup();
|
|
ip_vs_control_cleanup();
|
|
cleanup_nothing:
|
|
return ret;
|
|
}
|
|
|
|
static void __exit ip_vs_cleanup(void)
|
|
{
|
|
nf_unregister_hook(&ip_vs_forward_icmp_ops);
|
|
nf_unregister_hook(&ip_vs_post_routing_ops);
|
|
nf_unregister_hook(&ip_vs_out_ops);
|
|
nf_unregister_hook(&ip_vs_in_ops);
|
|
ip_vs_conn_cleanup();
|
|
ip_vs_app_cleanup();
|
|
ip_vs_protocol_cleanup();
|
|
ip_vs_control_cleanup();
|
|
IP_VS_INFO("ipvs unloaded.\n");
|
|
}
|
|
|
|
module_init(ip_vs_init);
|
|
module_exit(ip_vs_cleanup);
|
|
MODULE_LICENSE("GPL");
|