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xianfeng |
/*
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* ip_vs_xmit.c: various packet transmitters for IPVS
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*
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* Version: $Id: ip_vs_xmit.c,v 1.2 2002/11/30 01:50:35 wensong Exp $
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*
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* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
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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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* Changes:
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*
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*/
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#include <linux/kernel.h>
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#include <linux/ip.h>
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#include <linux/tcp.h> /* for tcphdr */
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#include <net/tcp.h> /* for csum_tcpudp_magic */
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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> /* for ip_route_output */
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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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/*
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* Destination cache to speed up outgoing route lookup
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*/
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static inline void
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__ip_vs_dst_set(struct ip_vs_dest *dest, u32 rtos, struct dst_entry *dst)
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{
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struct dst_entry *old_dst;
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old_dst = dest->dst_cache;
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dest->dst_cache = dst;
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dest->dst_rtos = rtos;
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dst_release(old_dst);
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}
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static inline struct dst_entry *
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__ip_vs_dst_check(struct ip_vs_dest *dest, u32 rtos, u32 cookie)
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{
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struct dst_entry *dst = dest->dst_cache;
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if (!dst)
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return NULL;
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if ((dst->obsolete || rtos != dest->dst_rtos) &&
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dst->ops->check(dst, cookie) == NULL) {
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dest->dst_cache = NULL;
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dst_release(dst);
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return NULL;
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}
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dst_hold(dst);
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return dst;
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}
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static inline struct rtable *
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__ip_vs_get_out_rt(struct ip_vs_conn *cp, u32 rtos)
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{
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struct rtable *rt; /* Route to the other host */
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struct ip_vs_dest *dest = cp->dest;
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if (dest) {
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spin_lock(&dest->dst_lock);
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if (!(rt = (struct rtable *)
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__ip_vs_dst_check(dest, rtos, 0))) {
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struct flowi fl = {
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.oif = 0,
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.nl_u = {
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.ip4_u = {
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.daddr = dest->addr,
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.saddr = 0,
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.tos = rtos, } },
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};
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if (ip_route_output_key(&rt, &fl)) {
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spin_unlock(&dest->dst_lock);
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IP_VS_DBG_RL("ip_route_output error, "
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"dest: %u.%u.%u.%u\n",
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NIPQUAD(dest->addr));
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return NULL;
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}
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__ip_vs_dst_set(dest, rtos, dst_clone(&rt->u.dst));
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IP_VS_DBG(10, "new dst %u.%u.%u.%u, refcnt=%d, rtos=%X\n",
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NIPQUAD(dest->addr),
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atomic_read(&rt->u.dst.__refcnt), rtos);
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}
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spin_unlock(&dest->dst_lock);
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} else {
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struct flowi fl = {
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.oif = 0,
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.nl_u = {
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.ip4_u = {
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.daddr = cp->daddr,
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.saddr = 0,
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.tos = rtos, } },
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};
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if (ip_route_output_key(&rt, &fl)) {
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IP_VS_DBG_RL("ip_route_output error, dest: "
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"%u.%u.%u.%u\n", NIPQUAD(cp->daddr));
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return NULL;
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}
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}
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return rt;
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}
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/*
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* Release dest->dst_cache before a dest is removed
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*/
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void
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ip_vs_dst_reset(struct ip_vs_dest *dest)
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{
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struct dst_entry *old_dst;
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old_dst = dest->dst_cache;
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dest->dst_cache = NULL;
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dst_release(old_dst);
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}
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#define IP_VS_XMIT(skb, rt) \
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do { \
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(skb)->ipvs_property = 1; \
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skb_forward_csum(skb); \
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NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, (skb), NULL, \
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(rt)->u.dst.dev, dst_output); \
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} while (0)
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| 136 |
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/*
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* NULL transmitter (do nothing except return NF_ACCEPT)
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*/
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int
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ip_vs_null_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
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struct ip_vs_protocol *pp)
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{
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/* we do not touch skb and do not need pskb ptr */
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return NF_ACCEPT;
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}
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| 148 |
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/*
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* Bypass transmitter
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* Let packets bypass the destination when the destination is not
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* available, it may be only used in transparent cache cluster.
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*/
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int
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ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
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struct ip_vs_protocol *pp)
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{
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struct rtable *rt; /* Route to the other host */
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| 159 |
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struct iphdr *iph = ip_hdr(skb);
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u8 tos = iph->tos;
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int mtu;
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struct flowi fl = {
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.oif = 0,
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.nl_u = {
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.ip4_u = {
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.daddr = iph->daddr,
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.saddr = 0,
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.tos = RT_TOS(tos), } },
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};
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EnterFunction(10);
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if (ip_route_output_key(&rt, &fl)) {
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IP_VS_DBG_RL("ip_vs_bypass_xmit(): ip_route_output error, "
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"dest: %u.%u.%u.%u\n", NIPQUAD(iph->daddr));
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goto tx_error_icmp;
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}
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| 178 |
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| 179 |
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/* MTU checking */
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mtu = dst_mtu(&rt->u.dst);
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| 181 |
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if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF))) {
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| 182 |
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ip_rt_put(rt);
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icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
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| 184 |
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IP_VS_DBG_RL("ip_vs_bypass_xmit(): frag needed\n");
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| 185 |
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goto tx_error;
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| 186 |
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}
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| 187 |
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| 188 |
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/*
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| 189 |
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* Call ip_send_check because we are not sure it is called
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| 190 |
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* after ip_defrag. Is copy-on-write needed?
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| 191 |
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*/
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| 192 |
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if (unlikely((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)) {
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| 193 |
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ip_rt_put(rt);
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| 194 |
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return NF_STOLEN;
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| 195 |
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}
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| 196 |
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ip_send_check(ip_hdr(skb));
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| 197 |
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| 198 |
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/* drop old route */
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| 199 |
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dst_release(skb->dst);
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| 200 |
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skb->dst = &rt->u.dst;
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| 201 |
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|
| 202 |
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/* Another hack: avoid icmp_send in ip_fragment */
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| 203 |
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skb->local_df = 1;
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| 204 |
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|
| 205 |
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IP_VS_XMIT(skb, rt);
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| 206 |
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|
| 207 |
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LeaveFunction(10);
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| 208 |
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return NF_STOLEN;
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| 209 |
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|
|
| 210 |
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tx_error_icmp:
|
| 211 |
|
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dst_link_failure(skb);
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| 212 |
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tx_error:
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| 213 |
|
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kfree_skb(skb);
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| 214 |
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LeaveFunction(10);
|
| 215 |
|
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return NF_STOLEN;
|
| 216 |
|
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}
|
| 217 |
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|
| 218 |
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|
| 219 |
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/*
|
| 220 |
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* NAT transmitter (only for outside-to-inside nat forwarding)
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| 221 |
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* Not used for related ICMP
|
| 222 |
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*/
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| 223 |
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int
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| 224 |
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ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
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| 225 |
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struct ip_vs_protocol *pp)
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| 226 |
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{
|
| 227 |
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struct rtable *rt; /* Route to the other host */
|
| 228 |
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int mtu;
|
| 229 |
|
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struct iphdr *iph = ip_hdr(skb);
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| 230 |
|
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| 231 |
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EnterFunction(10);
|
| 232 |
|
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|
| 233 |
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/* check if it is a connection of no-client-port */
|
| 234 |
|
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if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT)) {
|
| 235 |
|
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__be16 _pt, *p;
|
| 236 |
|
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p = skb_header_pointer(skb, iph->ihl*4, sizeof(_pt), &_pt);
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| 237 |
|
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if (p == NULL)
|
| 238 |
|
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goto tx_error;
|
| 239 |
|
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ip_vs_conn_fill_cport(cp, *p);
|
| 240 |
|
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IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p));
|
| 241 |
|
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}
|
| 242 |
|
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|
| 243 |
|
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if (!(rt = __ip_vs_get_out_rt(cp, RT_TOS(iph->tos))))
|
| 244 |
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goto tx_error_icmp;
|
| 245 |
|
|
|
| 246 |
|
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/* MTU checking */
|
| 247 |
|
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mtu = dst_mtu(&rt->u.dst);
|
| 248 |
|
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if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF))) {
|
| 249 |
|
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ip_rt_put(rt);
|
| 250 |
|
|
icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
|
| 251 |
|
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IP_VS_DBG_RL_PKT(0, pp, skb, 0, "ip_vs_nat_xmit(): frag needed for");
|
| 252 |
|
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goto tx_error;
|
| 253 |
|
|
}
|
| 254 |
|
|
|
| 255 |
|
|
/* copy-on-write the packet before mangling it */
|
| 256 |
|
|
if (!skb_make_writable(skb, sizeof(struct iphdr)))
|
| 257 |
|
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goto tx_error_put;
|
| 258 |
|
|
|
| 259 |
|
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if (skb_cow(skb, rt->u.dst.dev->hard_header_len))
|
| 260 |
|
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goto tx_error_put;
|
| 261 |
|
|
|
| 262 |
|
|
/* drop old route */
|
| 263 |
|
|
dst_release(skb->dst);
|
| 264 |
|
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skb->dst = &rt->u.dst;
|
| 265 |
|
|
|
| 266 |
|
|
/* mangle the packet */
|
| 267 |
|
|
if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp))
|
| 268 |
|
|
goto tx_error;
|
| 269 |
|
|
ip_hdr(skb)->daddr = cp->daddr;
|
| 270 |
|
|
ip_send_check(ip_hdr(skb));
|
| 271 |
|
|
|
| 272 |
|
|
IP_VS_DBG_PKT(10, pp, skb, 0, "After DNAT");
|
| 273 |
|
|
|
| 274 |
|
|
/* FIXME: when application helper enlarges the packet and the length
|
| 275 |
|
|
is larger than the MTU of outgoing device, there will be still
|
| 276 |
|
|
MTU problem. */
|
| 277 |
|
|
|
| 278 |
|
|
/* Another hack: avoid icmp_send in ip_fragment */
|
| 279 |
|
|
skb->local_df = 1;
|
| 280 |
|
|
|
| 281 |
|
|
IP_VS_XMIT(skb, rt);
|
| 282 |
|
|
|
| 283 |
|
|
LeaveFunction(10);
|
| 284 |
|
|
return NF_STOLEN;
|
| 285 |
|
|
|
| 286 |
|
|
tx_error_icmp:
|
| 287 |
|
|
dst_link_failure(skb);
|
| 288 |
|
|
tx_error:
|
| 289 |
|
|
LeaveFunction(10);
|
| 290 |
|
|
kfree_skb(skb);
|
| 291 |
|
|
return NF_STOLEN;
|
| 292 |
|
|
tx_error_put:
|
| 293 |
|
|
ip_rt_put(rt);
|
| 294 |
|
|
goto tx_error;
|
| 295 |
|
|
}
|
| 296 |
|
|
|
| 297 |
|
|
|
| 298 |
|
|
/*
|
| 299 |
|
|
* IP Tunneling transmitter
|
| 300 |
|
|
*
|
| 301 |
|
|
* This function encapsulates the packet in a new IP packet, its
|
| 302 |
|
|
* destination will be set to cp->daddr. Most code of this function
|
| 303 |
|
|
* is taken from ipip.c.
|
| 304 |
|
|
*
|
| 305 |
|
|
* It is used in VS/TUN cluster. The load balancer selects a real
|
| 306 |
|
|
* server from a cluster based on a scheduling algorithm,
|
| 307 |
|
|
* encapsulates the request packet and forwards it to the selected
|
| 308 |
|
|
* server. For example, all real servers are configured with
|
| 309 |
|
|
* "ifconfig tunl0 <Virtual IP Address> up". When the server receives
|
| 310 |
|
|
* the encapsulated packet, it will decapsulate the packet, processe
|
| 311 |
|
|
* the request and return the response packets directly to the client
|
| 312 |
|
|
* without passing the load balancer. This can greatly increase the
|
| 313 |
|
|
* scalability of virtual server.
|
| 314 |
|
|
*
|
| 315 |
|
|
* Used for ANY protocol
|
| 316 |
|
|
*/
|
| 317 |
|
|
int
|
| 318 |
|
|
ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
|
| 319 |
|
|
struct ip_vs_protocol *pp)
|
| 320 |
|
|
{
|
| 321 |
|
|
struct rtable *rt; /* Route to the other host */
|
| 322 |
|
|
struct net_device *tdev; /* Device to other host */
|
| 323 |
|
|
struct iphdr *old_iph = ip_hdr(skb);
|
| 324 |
|
|
u8 tos = old_iph->tos;
|
| 325 |
|
|
__be16 df = old_iph->frag_off;
|
| 326 |
|
|
sk_buff_data_t old_transport_header = skb->transport_header;
|
| 327 |
|
|
struct iphdr *iph; /* Our new IP header */
|
| 328 |
|
|
unsigned int max_headroom; /* The extra header space needed */
|
| 329 |
|
|
int mtu;
|
| 330 |
|
|
|
| 331 |
|
|
EnterFunction(10);
|
| 332 |
|
|
|
| 333 |
|
|
if (skb->protocol != htons(ETH_P_IP)) {
|
| 334 |
|
|
IP_VS_DBG_RL("ip_vs_tunnel_xmit(): protocol error, "
|
| 335 |
|
|
"ETH_P_IP: %d, skb protocol: %d\n",
|
| 336 |
|
|
htons(ETH_P_IP), skb->protocol);
|
| 337 |
|
|
goto tx_error;
|
| 338 |
|
|
}
|
| 339 |
|
|
|
| 340 |
|
|
if (!(rt = __ip_vs_get_out_rt(cp, RT_TOS(tos))))
|
| 341 |
|
|
goto tx_error_icmp;
|
| 342 |
|
|
|
| 343 |
|
|
tdev = rt->u.dst.dev;
|
| 344 |
|
|
|
| 345 |
|
|
mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
|
| 346 |
|
|
if (mtu < 68) {
|
| 347 |
|
|
ip_rt_put(rt);
|
| 348 |
|
|
IP_VS_DBG_RL("ip_vs_tunnel_xmit(): mtu less than 68\n");
|
| 349 |
|
|
goto tx_error;
|
| 350 |
|
|
}
|
| 351 |
|
|
if (skb->dst)
|
| 352 |
|
|
skb->dst->ops->update_pmtu(skb->dst, mtu);
|
| 353 |
|
|
|
| 354 |
|
|
df |= (old_iph->frag_off & htons(IP_DF));
|
| 355 |
|
|
|
| 356 |
|
|
if ((old_iph->frag_off & htons(IP_DF))
|
| 357 |
|
|
&& mtu < ntohs(old_iph->tot_len)) {
|
| 358 |
|
|
icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
|
| 359 |
|
|
ip_rt_put(rt);
|
| 360 |
|
|
IP_VS_DBG_RL("ip_vs_tunnel_xmit(): frag needed\n");
|
| 361 |
|
|
goto tx_error;
|
| 362 |
|
|
}
|
| 363 |
|
|
|
| 364 |
|
|
/*
|
| 365 |
|
|
* Okay, now see if we can stuff it in the buffer as-is.
|
| 366 |
|
|
*/
|
| 367 |
|
|
max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr);
|
| 368 |
|
|
|
| 369 |
|
|
if (skb_headroom(skb) < max_headroom
|
| 370 |
|
|
|| skb_cloned(skb) || skb_shared(skb)) {
|
| 371 |
|
|
struct sk_buff *new_skb =
|
| 372 |
|
|
skb_realloc_headroom(skb, max_headroom);
|
| 373 |
|
|
if (!new_skb) {
|
| 374 |
|
|
ip_rt_put(rt);
|
| 375 |
|
|
kfree_skb(skb);
|
| 376 |
|
|
IP_VS_ERR_RL("ip_vs_tunnel_xmit(): no memory\n");
|
| 377 |
|
|
return NF_STOLEN;
|
| 378 |
|
|
}
|
| 379 |
|
|
kfree_skb(skb);
|
| 380 |
|
|
skb = new_skb;
|
| 381 |
|
|
old_iph = ip_hdr(skb);
|
| 382 |
|
|
}
|
| 383 |
|
|
|
| 384 |
|
|
skb->transport_header = old_transport_header;
|
| 385 |
|
|
|
| 386 |
|
|
/* fix old IP header checksum */
|
| 387 |
|
|
ip_send_check(old_iph);
|
| 388 |
|
|
|
| 389 |
|
|
skb_push(skb, sizeof(struct iphdr));
|
| 390 |
|
|
skb_reset_network_header(skb);
|
| 391 |
|
|
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
|
| 392 |
|
|
|
| 393 |
|
|
/* drop old route */
|
| 394 |
|
|
dst_release(skb->dst);
|
| 395 |
|
|
skb->dst = &rt->u.dst;
|
| 396 |
|
|
|
| 397 |
|
|
/*
|
| 398 |
|
|
* Push down and install the IPIP header.
|
| 399 |
|
|
*/
|
| 400 |
|
|
iph = ip_hdr(skb);
|
| 401 |
|
|
iph->version = 4;
|
| 402 |
|
|
iph->ihl = sizeof(struct iphdr)>>2;
|
| 403 |
|
|
iph->frag_off = df;
|
| 404 |
|
|
iph->protocol = IPPROTO_IPIP;
|
| 405 |
|
|
iph->tos = tos;
|
| 406 |
|
|
iph->daddr = rt->rt_dst;
|
| 407 |
|
|
iph->saddr = rt->rt_src;
|
| 408 |
|
|
iph->ttl = old_iph->ttl;
|
| 409 |
|
|
iph->tot_len = htons(skb->len);
|
| 410 |
|
|
ip_select_ident(iph, &rt->u.dst, NULL);
|
| 411 |
|
|
ip_send_check(iph);
|
| 412 |
|
|
|
| 413 |
|
|
/* Another hack: avoid icmp_send in ip_fragment */
|
| 414 |
|
|
skb->local_df = 1;
|
| 415 |
|
|
|
| 416 |
|
|
IP_VS_XMIT(skb, rt);
|
| 417 |
|
|
|
| 418 |
|
|
LeaveFunction(10);
|
| 419 |
|
|
|
| 420 |
|
|
return NF_STOLEN;
|
| 421 |
|
|
|
| 422 |
|
|
tx_error_icmp:
|
| 423 |
|
|
dst_link_failure(skb);
|
| 424 |
|
|
tx_error:
|
| 425 |
|
|
kfree_skb(skb);
|
| 426 |
|
|
LeaveFunction(10);
|
| 427 |
|
|
return NF_STOLEN;
|
| 428 |
|
|
}
|
| 429 |
|
|
|
| 430 |
|
|
|
| 431 |
|
|
/*
|
| 432 |
|
|
* Direct Routing transmitter
|
| 433 |
|
|
* Used for ANY protocol
|
| 434 |
|
|
*/
|
| 435 |
|
|
int
|
| 436 |
|
|
ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
|
| 437 |
|
|
struct ip_vs_protocol *pp)
|
| 438 |
|
|
{
|
| 439 |
|
|
struct rtable *rt; /* Route to the other host */
|
| 440 |
|
|
struct iphdr *iph = ip_hdr(skb);
|
| 441 |
|
|
int mtu;
|
| 442 |
|
|
|
| 443 |
|
|
EnterFunction(10);
|
| 444 |
|
|
|
| 445 |
|
|
if (!(rt = __ip_vs_get_out_rt(cp, RT_TOS(iph->tos))))
|
| 446 |
|
|
goto tx_error_icmp;
|
| 447 |
|
|
|
| 448 |
|
|
/* MTU checking */
|
| 449 |
|
|
mtu = dst_mtu(&rt->u.dst);
|
| 450 |
|
|
if ((iph->frag_off & htons(IP_DF)) && skb->len > mtu) {
|
| 451 |
|
|
icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
|
| 452 |
|
|
ip_rt_put(rt);
|
| 453 |
|
|
IP_VS_DBG_RL("ip_vs_dr_xmit(): frag needed\n");
|
| 454 |
|
|
goto tx_error;
|
| 455 |
|
|
}
|
| 456 |
|
|
|
| 457 |
|
|
/*
|
| 458 |
|
|
* Call ip_send_check because we are not sure it is called
|
| 459 |
|
|
* after ip_defrag. Is copy-on-write needed?
|
| 460 |
|
|
*/
|
| 461 |
|
|
if (unlikely((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)) {
|
| 462 |
|
|
ip_rt_put(rt);
|
| 463 |
|
|
return NF_STOLEN;
|
| 464 |
|
|
}
|
| 465 |
|
|
ip_send_check(ip_hdr(skb));
|
| 466 |
|
|
|
| 467 |
|
|
/* drop old route */
|
| 468 |
|
|
dst_release(skb->dst);
|
| 469 |
|
|
skb->dst = &rt->u.dst;
|
| 470 |
|
|
|
| 471 |
|
|
/* Another hack: avoid icmp_send in ip_fragment */
|
| 472 |
|
|
skb->local_df = 1;
|
| 473 |
|
|
|
| 474 |
|
|
IP_VS_XMIT(skb, rt);
|
| 475 |
|
|
|
| 476 |
|
|
LeaveFunction(10);
|
| 477 |
|
|
return NF_STOLEN;
|
| 478 |
|
|
|
| 479 |
|
|
tx_error_icmp:
|
| 480 |
|
|
dst_link_failure(skb);
|
| 481 |
|
|
tx_error:
|
| 482 |
|
|
kfree_skb(skb);
|
| 483 |
|
|
LeaveFunction(10);
|
| 484 |
|
|
return NF_STOLEN;
|
| 485 |
|
|
}
|
| 486 |
|
|
|
| 487 |
|
|
|
| 488 |
|
|
/*
|
| 489 |
|
|
* ICMP packet transmitter
|
| 490 |
|
|
* called by the ip_vs_in_icmp
|
| 491 |
|
|
*/
|
| 492 |
|
|
int
|
| 493 |
|
|
ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
|
| 494 |
|
|
struct ip_vs_protocol *pp, int offset)
|
| 495 |
|
|
{
|
| 496 |
|
|
struct rtable *rt; /* Route to the other host */
|
| 497 |
|
|
int mtu;
|
| 498 |
|
|
int rc;
|
| 499 |
|
|
|
| 500 |
|
|
EnterFunction(10);
|
| 501 |
|
|
|
| 502 |
|
|
/* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
|
| 503 |
|
|
forwarded directly here, because there is no need to
|
| 504 |
|
|
translate address/port back */
|
| 505 |
|
|
if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
|
| 506 |
|
|
if (cp->packet_xmit)
|
| 507 |
|
|
rc = cp->packet_xmit(skb, cp, pp);
|
| 508 |
|
|
else
|
| 509 |
|
|
rc = NF_ACCEPT;
|
| 510 |
|
|
/* do not touch skb anymore */
|
| 511 |
|
|
atomic_inc(&cp->in_pkts);
|
| 512 |
|
|
goto out;
|
| 513 |
|
|
}
|
| 514 |
|
|
|
| 515 |
|
|
/*
|
| 516 |
|
|
* mangle and send the packet here (only for VS/NAT)
|
| 517 |
|
|
*/
|
| 518 |
|
|
|
| 519 |
|
|
if (!(rt = __ip_vs_get_out_rt(cp, RT_TOS(ip_hdr(skb)->tos))))
|
| 520 |
|
|
goto tx_error_icmp;
|
| 521 |
|
|
|
| 522 |
|
|
/* MTU checking */
|
| 523 |
|
|
mtu = dst_mtu(&rt->u.dst);
|
| 524 |
|
|
if ((skb->len > mtu) && (ip_hdr(skb)->frag_off & htons(IP_DF))) {
|
| 525 |
|
|
ip_rt_put(rt);
|
| 526 |
|
|
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
|
| 527 |
|
|
IP_VS_DBG_RL("ip_vs_in_icmp(): frag needed\n");
|
| 528 |
|
|
goto tx_error;
|
| 529 |
|
|
}
|
| 530 |
|
|
|
| 531 |
|
|
/* copy-on-write the packet before mangling it */
|
| 532 |
|
|
if (!skb_make_writable(skb, offset))
|
| 533 |
|
|
goto tx_error_put;
|
| 534 |
|
|
|
| 535 |
|
|
if (skb_cow(skb, rt->u.dst.dev->hard_header_len))
|
| 536 |
|
|
goto tx_error_put;
|
| 537 |
|
|
|
| 538 |
|
|
/* drop the old route when skb is not shared */
|
| 539 |
|
|
dst_release(skb->dst);
|
| 540 |
|
|
skb->dst = &rt->u.dst;
|
| 541 |
|
|
|
| 542 |
|
|
ip_vs_nat_icmp(skb, pp, cp, 0);
|
| 543 |
|
|
|
| 544 |
|
|
/* Another hack: avoid icmp_send in ip_fragment */
|
| 545 |
|
|
skb->local_df = 1;
|
| 546 |
|
|
|
| 547 |
|
|
IP_VS_XMIT(skb, rt);
|
| 548 |
|
|
|
| 549 |
|
|
rc = NF_STOLEN;
|
| 550 |
|
|
goto out;
|
| 551 |
|
|
|
| 552 |
|
|
tx_error_icmp:
|
| 553 |
|
|
dst_link_failure(skb);
|
| 554 |
|
|
tx_error:
|
| 555 |
|
|
dev_kfree_skb(skb);
|
| 556 |
|
|
rc = NF_STOLEN;
|
| 557 |
|
|
out:
|
| 558 |
|
|
LeaveFunction(10);
|
| 559 |
|
|
return rc;
|
| 560 |
|
|
tx_error_put:
|
| 561 |
|
|
ip_rt_put(rt);
|
| 562 |
|
|
goto tx_error;
|
| 563 |
|
|
}
|
