2 * ip_vs_xmit.c: various packet transmitters for IPVS
4 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
5 * Julian Anastasov <ja@ssi.bg>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
14 * Description of forwarding methods:
15 * - all transmitters are called from LOCAL_IN (remote clients) and
16 * LOCAL_OUT (local clients) but for ICMP can be called from FORWARD
17 * - not all connections have destination server, for example,
18 * connections in backup server when fwmark is used
19 * - bypass connections use daddr from packet
21 * - skb->dev is NULL, skb->protocol is not set (both are set in POST_ROUTING)
22 * - skb->pkt_type is not set yet
23 * - the only place where we can see skb->sk != NULL
26 #define KMSG_COMPONENT "IPVS"
27 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
29 #include <linux/kernel.h>
30 #include <linux/slab.h>
31 #include <linux/tcp.h> /* for tcphdr */
33 #include <net/tcp.h> /* for csum_tcpudp_magic */
35 #include <net/icmp.h> /* for icmp_send */
36 #include <net/route.h> /* for ip_route_output */
38 #include <net/ip6_route.h>
39 #include <net/addrconf.h>
40 #include <linux/icmpv6.h>
41 #include <linux/netfilter.h>
42 #include <linux/netfilter_ipv4.h>
44 #include <net/ip_vs.h>
48 * Destination cache to speed up outgoing route lookup
51 __ip_vs_dst_set(struct ip_vs_dest
*dest
, u32 rtos
, struct dst_entry
*dst
,
54 struct dst_entry
*old_dst
;
56 old_dst
= dest
->dst_cache
;
57 dest
->dst_cache
= dst
;
58 dest
->dst_rtos
= rtos
;
59 dest
->dst_cookie
= dst_cookie
;
63 static inline struct dst_entry
*
64 __ip_vs_dst_check(struct ip_vs_dest
*dest
, u32 rtos
)
66 struct dst_entry
*dst
= dest
->dst_cache
;
70 if ((dst
->obsolete
|| rtos
!= dest
->dst_rtos
) &&
71 dst
->ops
->check(dst
, dest
->dst_cookie
) == NULL
) {
72 dest
->dst_cache
= NULL
;
81 * Get route to destination or remote server
82 * rt_mode: flags, &1=Allow local dest, &2=Allow non-local dest,
83 * &4=Allow redirect from remote daddr to local
85 static struct rtable
*
86 __ip_vs_get_out_rt(struct sk_buff
*skb
, struct ip_vs_dest
*dest
,
87 __be32 daddr
, u32 rtos
, int rt_mode
)
89 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
90 struct rtable
*rt
; /* Route to the other host */
91 struct rtable
*ort
; /* Original route */
95 spin_lock(&dest
->dst_lock
);
96 if (!(rt
= (struct rtable
*)
97 __ip_vs_dst_check(dest
, rtos
))) {
99 .fl4_dst
= dest
->addr
.ip
,
103 if (ip_route_output_key(net
, &rt
, &fl
)) {
104 spin_unlock(&dest
->dst_lock
);
105 IP_VS_DBG_RL("ip_route_output error, dest: %pI4\n",
109 __ip_vs_dst_set(dest
, rtos
, dst_clone(&rt
->dst
), 0);
110 IP_VS_DBG(10, "new dst %pI4, refcnt=%d, rtos=%X\n",
112 atomic_read(&rt
->dst
.__refcnt
), rtos
);
114 spin_unlock(&dest
->dst_lock
);
121 if (ip_route_output_key(net
, &rt
, &fl
)) {
122 IP_VS_DBG_RL("ip_route_output error, dest: %pI4\n",
128 local
= rt
->rt_flags
& RTCF_LOCAL
;
129 if (!((local
? 1 : 2) & rt_mode
)) {
130 IP_VS_DBG_RL("Stopping traffic to %s address, dest: %pI4\n",
131 (rt
->rt_flags
& RTCF_LOCAL
) ?
132 "local":"non-local", &rt
->rt_dst
);
136 if (local
&& !(rt_mode
& 4) && !((ort
= skb_rtable(skb
)) &&
137 ort
->rt_flags
& RTCF_LOCAL
)) {
138 IP_VS_DBG_RL("Redirect from non-local address %pI4 to local "
139 "requires NAT method, dest: %pI4\n",
140 &ip_hdr(skb
)->daddr
, &rt
->rt_dst
);
144 if (unlikely(!local
&& ipv4_is_loopback(ip_hdr(skb
)->saddr
))) {
145 IP_VS_DBG_RL("Stopping traffic from loopback address %pI4 "
146 "to non-local address, dest: %pI4\n",
147 &ip_hdr(skb
)->saddr
, &rt
->rt_dst
);
155 /* Reroute packet to local IPv4 stack after DNAT */
157 __ip_vs_reroute_locally(struct sk_buff
*skb
)
159 struct rtable
*rt
= skb_rtable(skb
);
160 struct net_device
*dev
= rt
->dst
.dev
;
161 struct net
*net
= dev_net(dev
);
162 struct iphdr
*iph
= ip_hdr(skb
);
164 if (rt_is_input_route(rt
)) {
165 unsigned long orefdst
= skb
->_skb_refdst
;
167 if (ip_route_input(skb
, iph
->daddr
, iph
->saddr
,
170 refdst_drop(orefdst
);
173 .fl4_dst
= iph
->daddr
,
174 .fl4_src
= iph
->saddr
,
175 .fl4_tos
= RT_TOS(iph
->tos
),
180 if (ip_route_output_key(net
, &rt
, &fl
))
182 if (!(rt
->rt_flags
& RTCF_LOCAL
)) {
186 /* Drop old route. */
188 skb_dst_set(skb
, &rt
->dst
);
193 #ifdef CONFIG_IP_VS_IPV6
195 static inline int __ip_vs_is_local_route6(struct rt6_info
*rt
)
197 return rt
->rt6i_dev
&& rt
->rt6i_dev
->flags
& IFF_LOOPBACK
;
200 static struct dst_entry
*
201 __ip_vs_route_output_v6(struct net
*net
, struct in6_addr
*daddr
,
202 struct in6_addr
*ret_saddr
, int do_xfrm
)
204 struct dst_entry
*dst
;
209 dst
= ip6_route_output(net
, NULL
, &fl
);
214 if (ipv6_addr_any(&fl
.fl6_src
) &&
215 ipv6_dev_get_saddr(net
, ip6_dst_idev(dst
)->dev
,
216 &fl
.fl6_dst
, 0, &fl
.fl6_src
) < 0)
218 if (do_xfrm
&& xfrm_lookup(net
, &dst
, &fl
, NULL
, 0) < 0)
220 ipv6_addr_copy(ret_saddr
, &fl
.fl6_src
);
225 IP_VS_DBG_RL("ip6_route_output error, dest: %pI6\n", daddr
);
230 * Get route to destination or remote server
231 * rt_mode: flags, &1=Allow local dest, &2=Allow non-local dest,
232 * &4=Allow redirect from remote daddr to local
234 static struct rt6_info
*
235 __ip_vs_get_out_rt_v6(struct sk_buff
*skb
, struct ip_vs_dest
*dest
,
236 struct in6_addr
*daddr
, struct in6_addr
*ret_saddr
,
237 int do_xfrm
, int rt_mode
)
239 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
240 struct rt6_info
*rt
; /* Route to the other host */
241 struct rt6_info
*ort
; /* Original route */
242 struct dst_entry
*dst
;
246 spin_lock(&dest
->dst_lock
);
247 rt
= (struct rt6_info
*)__ip_vs_dst_check(dest
, 0);
251 dst
= __ip_vs_route_output_v6(net
, &dest
->addr
.in6
,
255 spin_unlock(&dest
->dst_lock
);
258 rt
= (struct rt6_info
*) dst
;
259 cookie
= rt
->rt6i_node
? rt
->rt6i_node
->fn_sernum
: 0;
260 __ip_vs_dst_set(dest
, 0, dst_clone(&rt
->dst
), cookie
);
261 IP_VS_DBG(10, "new dst %pI6, src %pI6, refcnt=%d\n",
262 &dest
->addr
.in6
, &dest
->dst_saddr
,
263 atomic_read(&rt
->dst
.__refcnt
));
266 ipv6_addr_copy(ret_saddr
, &dest
->dst_saddr
);
267 spin_unlock(&dest
->dst_lock
);
269 dst
= __ip_vs_route_output_v6(net
, daddr
, ret_saddr
, do_xfrm
);
272 rt
= (struct rt6_info
*) dst
;
275 local
= __ip_vs_is_local_route6(rt
);
276 if (!((local
? 1 : 2) & rt_mode
)) {
277 IP_VS_DBG_RL("Stopping traffic to %s address, dest: %pI6\n",
278 local
? "local":"non-local", daddr
);
279 dst_release(&rt
->dst
);
282 if (local
&& !(rt_mode
& 4) &&
283 !((ort
= (struct rt6_info
*) skb_dst(skb
)) &&
284 __ip_vs_is_local_route6(ort
))) {
285 IP_VS_DBG_RL("Redirect from non-local address %pI6 to local "
286 "requires NAT method, dest: %pI6\n",
287 &ipv6_hdr(skb
)->daddr
, daddr
);
288 dst_release(&rt
->dst
);
291 if (unlikely(!local
&& (!skb
->dev
|| skb
->dev
->flags
& IFF_LOOPBACK
) &&
292 ipv6_addr_type(&ipv6_hdr(skb
)->saddr
) &
293 IPV6_ADDR_LOOPBACK
)) {
294 IP_VS_DBG_RL("Stopping traffic from loopback address %pI6 "
295 "to non-local address, dest: %pI6\n",
296 &ipv6_hdr(skb
)->saddr
, daddr
);
297 dst_release(&rt
->dst
);
307 * Release dest->dst_cache before a dest is removed
310 ip_vs_dst_reset(struct ip_vs_dest
*dest
)
312 struct dst_entry
*old_dst
;
314 old_dst
= dest
->dst_cache
;
315 dest
->dst_cache
= NULL
;
316 dst_release(old_dst
);
319 #define IP_VS_XMIT_TUNNEL(skb, cp) \
321 int __ret = NF_ACCEPT; \
323 (skb)->ipvs_property = 1; \
324 if (unlikely((cp)->flags & IP_VS_CONN_F_NFCT)) \
325 __ret = ip_vs_confirm_conntrack(skb, cp); \
326 if (__ret == NF_ACCEPT) { \
328 skb_forward_csum(skb); \
333 #define IP_VS_XMIT_NAT(pf, skb, cp, local) \
335 (skb)->ipvs_property = 1; \
336 if (likely(!((cp)->flags & IP_VS_CONN_F_NFCT))) \
337 ip_vs_notrack(skb); \
339 ip_vs_update_conntrack(skb, cp, 1); \
342 skb_forward_csum(skb); \
343 NF_HOOK(pf, NF_INET_LOCAL_OUT, (skb), NULL, \
344 skb_dst(skb)->dev, dst_output); \
347 #define IP_VS_XMIT(pf, skb, cp, local) \
349 (skb)->ipvs_property = 1; \
350 if (likely(!((cp)->flags & IP_VS_CONN_F_NFCT))) \
351 ip_vs_notrack(skb); \
354 skb_forward_csum(skb); \
355 NF_HOOK(pf, NF_INET_LOCAL_OUT, (skb), NULL, \
356 skb_dst(skb)->dev, dst_output); \
361 * NULL transmitter (do nothing except return NF_ACCEPT)
364 ip_vs_null_xmit(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
365 struct ip_vs_protocol
*pp
)
367 /* we do not touch skb and do not need pskb ptr */
368 IP_VS_XMIT(NFPROTO_IPV4
, skb
, cp
, 1);
374 * Let packets bypass the destination when the destination is not
375 * available, it may be only used in transparent cache cluster.
378 ip_vs_bypass_xmit(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
379 struct ip_vs_protocol
*pp
)
381 struct rtable
*rt
; /* Route to the other host */
382 struct iphdr
*iph
= ip_hdr(skb
);
387 if (!(rt
= __ip_vs_get_out_rt(skb
, NULL
, iph
->daddr
,
388 RT_TOS(iph
->tos
), 2)))
392 mtu
= dst_mtu(&rt
->dst
);
393 if ((skb
->len
> mtu
) && (iph
->frag_off
& htons(IP_DF
))) {
395 icmp_send(skb
, ICMP_DEST_UNREACH
,ICMP_FRAG_NEEDED
, htonl(mtu
));
396 IP_VS_DBG_RL("%s(): frag needed\n", __func__
);
401 * Call ip_send_check because we are not sure it is called
402 * after ip_defrag. Is copy-on-write needed?
404 if (unlikely((skb
= skb_share_check(skb
, GFP_ATOMIC
)) == NULL
)) {
408 ip_send_check(ip_hdr(skb
));
412 skb_dst_set(skb
, &rt
->dst
);
414 /* Another hack: avoid icmp_send in ip_fragment */
417 IP_VS_XMIT(NFPROTO_IPV4
, skb
, cp
, 0);
423 dst_link_failure(skb
);
430 #ifdef CONFIG_IP_VS_IPV6
432 ip_vs_bypass_xmit_v6(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
433 struct ip_vs_protocol
*pp
)
435 struct rt6_info
*rt
; /* Route to the other host */
436 struct ipv6hdr
*iph
= ipv6_hdr(skb
);
441 if (!(rt
= __ip_vs_get_out_rt_v6(skb
, NULL
, &iph
->daddr
, NULL
, 0, 2)))
445 mtu
= dst_mtu(&rt
->dst
);
446 if (skb
->len
> mtu
) {
448 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
450 skb
->dev
= net
->loopback_dev
;
452 icmpv6_send(skb
, ICMPV6_PKT_TOOBIG
, 0, mtu
);
453 dst_release(&rt
->dst
);
454 IP_VS_DBG_RL("%s(): frag needed\n", __func__
);
459 * Call ip_send_check because we are not sure it is called
460 * after ip_defrag. Is copy-on-write needed?
462 skb
= skb_share_check(skb
, GFP_ATOMIC
);
463 if (unlikely(skb
== NULL
)) {
464 dst_release(&rt
->dst
);
470 skb_dst_set(skb
, &rt
->dst
);
472 /* Another hack: avoid icmp_send in ip_fragment */
475 IP_VS_XMIT(NFPROTO_IPV6
, skb
, cp
, 0);
481 dst_link_failure(skb
);
490 * NAT transmitter (only for outside-to-inside nat forwarding)
491 * Not used for related ICMP
494 ip_vs_nat_xmit(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
495 struct ip_vs_protocol
*pp
)
497 struct rtable
*rt
; /* Route to the other host */
499 struct iphdr
*iph
= ip_hdr(skb
);
504 /* check if it is a connection of no-client-port */
505 if (unlikely(cp
->flags
& IP_VS_CONN_F_NO_CPORT
)) {
507 p
= skb_header_pointer(skb
, iph
->ihl
*4, sizeof(_pt
), &_pt
);
510 ip_vs_conn_fill_cport(cp
, *p
);
511 IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p
));
514 if (!(rt
= __ip_vs_get_out_rt(skb
, cp
->dest
, cp
->daddr
.ip
,
515 RT_TOS(iph
->tos
), 1|2|4)))
517 local
= rt
->rt_flags
& RTCF_LOCAL
;
519 * Avoid duplicate tuple in reply direction for NAT traffic
520 * to local address when connection is sync-ed
522 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
523 if (cp
->flags
& IP_VS_CONN_F_SYNC
&& local
) {
524 enum ip_conntrack_info ctinfo
;
525 struct nf_conn
*ct
= ct
= nf_ct_get(skb
, &ctinfo
);
527 if (ct
&& !nf_ct_is_untracked(ct
)) {
528 IP_VS_DBG_RL_PKT(10, AF_INET
, pp
, skb
, 0,
530 "stopping DNAT to local address");
536 /* From world but DNAT to loopback address? */
537 if (local
&& ipv4_is_loopback(rt
->rt_dst
) &&
538 rt_is_input_route(skb_rtable(skb
))) {
539 IP_VS_DBG_RL_PKT(1, AF_INET
, pp
, skb
, 0, "ip_vs_nat_xmit(): "
540 "stopping DNAT to loopback address");
545 mtu
= dst_mtu(&rt
->dst
);
546 if ((skb
->len
> mtu
) && (iph
->frag_off
& htons(IP_DF
))) {
547 icmp_send(skb
, ICMP_DEST_UNREACH
,ICMP_FRAG_NEEDED
, htonl(mtu
));
548 IP_VS_DBG_RL_PKT(0, AF_INET
, pp
, skb
, 0,
549 "ip_vs_nat_xmit(): frag needed for");
553 /* copy-on-write the packet before mangling it */
554 if (!skb_make_writable(skb
, sizeof(struct iphdr
)))
557 if (skb_cow(skb
, rt
->dst
.dev
->hard_header_len
))
560 /* mangle the packet */
561 if (pp
->dnat_handler
&& !pp
->dnat_handler(skb
, pp
, cp
))
563 ip_hdr(skb
)->daddr
= cp
->daddr
.ip
;
564 ip_send_check(ip_hdr(skb
));
569 skb_dst_set(skb
, &rt
->dst
);
573 * Some IPv4 replies get local address from routes,
574 * not from iph, so while we DNAT after routing
575 * we need this second input/output route.
577 if (!__ip_vs_reroute_locally(skb
))
581 IP_VS_DBG_PKT(10, AF_INET
, pp
, skb
, 0, "After DNAT");
583 /* FIXME: when application helper enlarges the packet and the length
584 is larger than the MTU of outgoing device, there will be still
587 /* Another hack: avoid icmp_send in ip_fragment */
590 IP_VS_XMIT_NAT(NFPROTO_IPV4
, skb
, cp
, local
);
596 dst_link_failure(skb
);
606 #ifdef CONFIG_IP_VS_IPV6
608 ip_vs_nat_xmit_v6(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
609 struct ip_vs_protocol
*pp
)
611 struct rt6_info
*rt
; /* Route to the other host */
617 /* check if it is a connection of no-client-port */
618 if (unlikely(cp
->flags
& IP_VS_CONN_F_NO_CPORT
)) {
620 p
= skb_header_pointer(skb
, sizeof(struct ipv6hdr
),
624 ip_vs_conn_fill_cport(cp
, *p
);
625 IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p
));
628 if (!(rt
= __ip_vs_get_out_rt_v6(skb
, cp
->dest
, &cp
->daddr
.in6
, NULL
,
631 local
= __ip_vs_is_local_route6(rt
);
633 * Avoid duplicate tuple in reply direction for NAT traffic
634 * to local address when connection is sync-ed
636 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
637 if (cp
->flags
& IP_VS_CONN_F_SYNC
&& local
) {
638 enum ip_conntrack_info ctinfo
;
639 struct nf_conn
*ct
= ct
= nf_ct_get(skb
, &ctinfo
);
641 if (ct
&& !nf_ct_is_untracked(ct
)) {
642 IP_VS_DBG_RL_PKT(10, AF_INET6
, pp
, skb
, 0,
643 "ip_vs_nat_xmit_v6(): "
644 "stopping DNAT to local address");
650 /* From world but DNAT to loopback address? */
651 if (local
&& skb
->dev
&& !(skb
->dev
->flags
& IFF_LOOPBACK
) &&
652 ipv6_addr_type(&rt
->rt6i_dst
.addr
) & IPV6_ADDR_LOOPBACK
) {
653 IP_VS_DBG_RL_PKT(1, AF_INET6
, pp
, skb
, 0,
654 "ip_vs_nat_xmit_v6(): "
655 "stopping DNAT to loopback address");
660 mtu
= dst_mtu(&rt
->dst
);
661 if (skb
->len
> mtu
) {
663 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
665 skb
->dev
= net
->loopback_dev
;
667 icmpv6_send(skb
, ICMPV6_PKT_TOOBIG
, 0, mtu
);
668 IP_VS_DBG_RL_PKT(0, AF_INET6
, pp
, skb
, 0,
669 "ip_vs_nat_xmit_v6(): frag needed for");
673 /* copy-on-write the packet before mangling it */
674 if (!skb_make_writable(skb
, sizeof(struct ipv6hdr
)))
677 if (skb_cow(skb
, rt
->dst
.dev
->hard_header_len
))
680 /* mangle the packet */
681 if (pp
->dnat_handler
&& !pp
->dnat_handler(skb
, pp
, cp
))
683 ipv6_addr_copy(&ipv6_hdr(skb
)->daddr
, &cp
->daddr
.in6
);
685 if (!local
|| !skb
->dev
) {
686 /* drop the old route when skb is not shared */
688 skb_dst_set(skb
, &rt
->dst
);
690 /* destined to loopback, do we need to change route? */
691 dst_release(&rt
->dst
);
694 IP_VS_DBG_PKT(10, AF_INET6
, pp
, skb
, 0, "After DNAT");
696 /* FIXME: when application helper enlarges the packet and the length
697 is larger than the MTU of outgoing device, there will be still
700 /* Another hack: avoid icmp_send in ip_fragment */
703 IP_VS_XMIT_NAT(NFPROTO_IPV6
, skb
, cp
, local
);
709 dst_link_failure(skb
);
715 dst_release(&rt
->dst
);
722 * IP Tunneling transmitter
724 * This function encapsulates the packet in a new IP packet, its
725 * destination will be set to cp->daddr. Most code of this function
726 * is taken from ipip.c.
728 * It is used in VS/TUN cluster. The load balancer selects a real
729 * server from a cluster based on a scheduling algorithm,
730 * encapsulates the request packet and forwards it to the selected
731 * server. For example, all real servers are configured with
732 * "ifconfig tunl0 <Virtual IP Address> up". When the server receives
733 * the encapsulated packet, it will decapsulate the packet, processe
734 * the request and return the response packets directly to the client
735 * without passing the load balancer. This can greatly increase the
736 * scalability of virtual server.
738 * Used for ANY protocol
741 ip_vs_tunnel_xmit(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
742 struct ip_vs_protocol
*pp
)
744 struct rtable
*rt
; /* Route to the other host */
745 struct net_device
*tdev
; /* Device to other host */
746 struct iphdr
*old_iph
= ip_hdr(skb
);
747 u8 tos
= old_iph
->tos
;
748 __be16 df
= old_iph
->frag_off
;
749 struct iphdr
*iph
; /* Our new IP header */
750 unsigned int max_headroom
; /* The extra header space needed */
756 if (!(rt
= __ip_vs_get_out_rt(skb
, cp
->dest
, cp
->daddr
.ip
,
759 if (rt
->rt_flags
& RTCF_LOCAL
) {
761 IP_VS_XMIT(NFPROTO_IPV4
, skb
, cp
, 1);
766 mtu
= dst_mtu(&rt
->dst
) - sizeof(struct iphdr
);
768 IP_VS_DBG_RL("%s(): mtu less than 68\n", __func__
);
772 skb_dst(skb
)->ops
->update_pmtu(skb_dst(skb
), mtu
);
774 df
|= (old_iph
->frag_off
& htons(IP_DF
));
776 if ((old_iph
->frag_off
& htons(IP_DF
))
777 && mtu
< ntohs(old_iph
->tot_len
)) {
778 icmp_send(skb
, ICMP_DEST_UNREACH
,ICMP_FRAG_NEEDED
, htonl(mtu
));
779 IP_VS_DBG_RL("%s(): frag needed\n", __func__
);
784 * Okay, now see if we can stuff it in the buffer as-is.
786 max_headroom
= LL_RESERVED_SPACE(tdev
) + sizeof(struct iphdr
);
788 if (skb_headroom(skb
) < max_headroom
789 || skb_cloned(skb
) || skb_shared(skb
)) {
790 struct sk_buff
*new_skb
=
791 skb_realloc_headroom(skb
, max_headroom
);
795 IP_VS_ERR_RL("%s(): no memory\n", __func__
);
800 old_iph
= ip_hdr(skb
);
803 skb
->transport_header
= skb
->network_header
;
805 /* fix old IP header checksum */
806 ip_send_check(old_iph
);
808 skb_push(skb
, sizeof(struct iphdr
));
809 skb_reset_network_header(skb
);
810 memset(&(IPCB(skb
)->opt
), 0, sizeof(IPCB(skb
)->opt
));
814 skb_dst_set(skb
, &rt
->dst
);
817 * Push down and install the IPIP header.
821 iph
->ihl
= sizeof(struct iphdr
)>>2;
823 iph
->protocol
= IPPROTO_IPIP
;
825 iph
->daddr
= rt
->rt_dst
;
826 iph
->saddr
= rt
->rt_src
;
827 iph
->ttl
= old_iph
->ttl
;
828 ip_select_ident(iph
, &rt
->dst
, NULL
);
830 /* Another hack: avoid icmp_send in ip_fragment */
833 ret
= IP_VS_XMIT_TUNNEL(skb
, cp
);
834 if (ret
== NF_ACCEPT
)
836 else if (ret
== NF_DROP
)
844 dst_link_failure(skb
);
854 #ifdef CONFIG_IP_VS_IPV6
856 ip_vs_tunnel_xmit_v6(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
857 struct ip_vs_protocol
*pp
)
859 struct rt6_info
*rt
; /* Route to the other host */
860 struct in6_addr saddr
; /* Source for tunnel */
861 struct net_device
*tdev
; /* Device to other host */
862 struct ipv6hdr
*old_iph
= ipv6_hdr(skb
);
863 struct ipv6hdr
*iph
; /* Our new IP header */
864 unsigned int max_headroom
; /* The extra header space needed */
870 if (!(rt
= __ip_vs_get_out_rt_v6(skb
, cp
->dest
, &cp
->daddr
.in6
,
873 if (__ip_vs_is_local_route6(rt
)) {
874 dst_release(&rt
->dst
);
875 IP_VS_XMIT(NFPROTO_IPV6
, skb
, cp
, 1);
880 mtu
= dst_mtu(&rt
->dst
) - sizeof(struct ipv6hdr
);
881 if (mtu
< IPV6_MIN_MTU
) {
882 IP_VS_DBG_RL("%s(): mtu less than %d\n", __func__
,
887 skb_dst(skb
)->ops
->update_pmtu(skb_dst(skb
), mtu
);
889 if (mtu
< ntohs(old_iph
->payload_len
) + sizeof(struct ipv6hdr
)) {
891 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
893 skb
->dev
= net
->loopback_dev
;
895 icmpv6_send(skb
, ICMPV6_PKT_TOOBIG
, 0, mtu
);
896 IP_VS_DBG_RL("%s(): frag needed\n", __func__
);
901 * Okay, now see if we can stuff it in the buffer as-is.
903 max_headroom
= LL_RESERVED_SPACE(tdev
) + sizeof(struct ipv6hdr
);
905 if (skb_headroom(skb
) < max_headroom
906 || skb_cloned(skb
) || skb_shared(skb
)) {
907 struct sk_buff
*new_skb
=
908 skb_realloc_headroom(skb
, max_headroom
);
910 dst_release(&rt
->dst
);
912 IP_VS_ERR_RL("%s(): no memory\n", __func__
);
917 old_iph
= ipv6_hdr(skb
);
920 skb
->transport_header
= skb
->network_header
;
922 skb_push(skb
, sizeof(struct ipv6hdr
));
923 skb_reset_network_header(skb
);
924 memset(&(IPCB(skb
)->opt
), 0, sizeof(IPCB(skb
)->opt
));
928 skb_dst_set(skb
, &rt
->dst
);
931 * Push down and install the IPIP header.
935 iph
->nexthdr
= IPPROTO_IPV6
;
936 iph
->payload_len
= old_iph
->payload_len
;
937 be16_add_cpu(&iph
->payload_len
, sizeof(*old_iph
));
938 iph
->priority
= old_iph
->priority
;
939 memset(&iph
->flow_lbl
, 0, sizeof(iph
->flow_lbl
));
940 ipv6_addr_copy(&iph
->daddr
, &cp
->daddr
.in6
);
941 ipv6_addr_copy(&iph
->saddr
, &saddr
);
942 iph
->hop_limit
= old_iph
->hop_limit
;
944 /* Another hack: avoid icmp_send in ip_fragment */
947 ret
= IP_VS_XMIT_TUNNEL(skb
, cp
);
948 if (ret
== NF_ACCEPT
)
950 else if (ret
== NF_DROP
)
958 dst_link_failure(skb
);
964 dst_release(&rt
->dst
);
971 * Direct Routing transmitter
972 * Used for ANY protocol
975 ip_vs_dr_xmit(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
976 struct ip_vs_protocol
*pp
)
978 struct rtable
*rt
; /* Route to the other host */
979 struct iphdr
*iph
= ip_hdr(skb
);
984 if (!(rt
= __ip_vs_get_out_rt(skb
, cp
->dest
, cp
->daddr
.ip
,
985 RT_TOS(iph
->tos
), 1|2)))
987 if (rt
->rt_flags
& RTCF_LOCAL
) {
989 IP_VS_XMIT(NFPROTO_IPV4
, skb
, cp
, 1);
993 mtu
= dst_mtu(&rt
->dst
);
994 if ((iph
->frag_off
& htons(IP_DF
)) && skb
->len
> mtu
) {
995 icmp_send(skb
, ICMP_DEST_UNREACH
,ICMP_FRAG_NEEDED
, htonl(mtu
));
997 IP_VS_DBG_RL("%s(): frag needed\n", __func__
);
1002 * Call ip_send_check because we are not sure it is called
1003 * after ip_defrag. Is copy-on-write needed?
1005 if (unlikely((skb
= skb_share_check(skb
, GFP_ATOMIC
)) == NULL
)) {
1009 ip_send_check(ip_hdr(skb
));
1011 /* drop old route */
1013 skb_dst_set(skb
, &rt
->dst
);
1015 /* Another hack: avoid icmp_send in ip_fragment */
1018 IP_VS_XMIT(NFPROTO_IPV4
, skb
, cp
, 0);
1024 dst_link_failure(skb
);
1031 #ifdef CONFIG_IP_VS_IPV6
1033 ip_vs_dr_xmit_v6(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
1034 struct ip_vs_protocol
*pp
)
1036 struct rt6_info
*rt
; /* Route to the other host */
1041 if (!(rt
= __ip_vs_get_out_rt_v6(skb
, cp
->dest
, &cp
->daddr
.in6
, NULL
,
1044 if (__ip_vs_is_local_route6(rt
)) {
1045 dst_release(&rt
->dst
);
1046 IP_VS_XMIT(NFPROTO_IPV6
, skb
, cp
, 1);
1050 mtu
= dst_mtu(&rt
->dst
);
1051 if (skb
->len
> mtu
) {
1053 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
1055 skb
->dev
= net
->loopback_dev
;
1057 icmpv6_send(skb
, ICMPV6_PKT_TOOBIG
, 0, mtu
);
1058 dst_release(&rt
->dst
);
1059 IP_VS_DBG_RL("%s(): frag needed\n", __func__
);
1064 * Call ip_send_check because we are not sure it is called
1065 * after ip_defrag. Is copy-on-write needed?
1067 skb
= skb_share_check(skb
, GFP_ATOMIC
);
1068 if (unlikely(skb
== NULL
)) {
1069 dst_release(&rt
->dst
);
1073 /* drop old route */
1075 skb_dst_set(skb
, &rt
->dst
);
1077 /* Another hack: avoid icmp_send in ip_fragment */
1080 IP_VS_XMIT(NFPROTO_IPV6
, skb
, cp
, 0);
1086 dst_link_failure(skb
);
1096 * ICMP packet transmitter
1097 * called by the ip_vs_in_icmp
1100 ip_vs_icmp_xmit(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
1101 struct ip_vs_protocol
*pp
, int offset
)
1103 struct rtable
*rt
; /* Route to the other host */
1110 /* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
1111 forwarded directly here, because there is no need to
1112 translate address/port back */
1113 if (IP_VS_FWD_METHOD(cp
) != IP_VS_CONN_F_MASQ
) {
1114 if (cp
->packet_xmit
)
1115 rc
= cp
->packet_xmit(skb
, cp
, pp
);
1118 /* do not touch skb anymore */
1119 atomic_inc(&cp
->in_pkts
);
1124 * mangle and send the packet here (only for VS/NAT)
1127 if (!(rt
= __ip_vs_get_out_rt(skb
, cp
->dest
, cp
->daddr
.ip
,
1128 RT_TOS(ip_hdr(skb
)->tos
), 1|2|4)))
1130 local
= rt
->rt_flags
& RTCF_LOCAL
;
1133 * Avoid duplicate tuple in reply direction for NAT traffic
1134 * to local address when connection is sync-ed
1136 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1137 if (cp
->flags
& IP_VS_CONN_F_SYNC
&& local
) {
1138 enum ip_conntrack_info ctinfo
;
1139 struct nf_conn
*ct
= ct
= nf_ct_get(skb
, &ctinfo
);
1141 if (ct
&& !nf_ct_is_untracked(ct
)) {
1142 IP_VS_DBG(10, "%s(): "
1143 "stopping DNAT to local address %pI4\n",
1144 __func__
, &cp
->daddr
.ip
);
1150 /* From world but DNAT to loopback address? */
1151 if (local
&& ipv4_is_loopback(rt
->rt_dst
) &&
1152 rt_is_input_route(skb_rtable(skb
))) {
1153 IP_VS_DBG(1, "%s(): "
1154 "stopping DNAT to loopback %pI4\n",
1155 __func__
, &cp
->daddr
.ip
);
1160 mtu
= dst_mtu(&rt
->dst
);
1161 if ((skb
->len
> mtu
) && (ip_hdr(skb
)->frag_off
& htons(IP_DF
))) {
1162 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_FRAG_NEEDED
, htonl(mtu
));
1163 IP_VS_DBG_RL("%s(): frag needed\n", __func__
);
1167 /* copy-on-write the packet before mangling it */
1168 if (!skb_make_writable(skb
, offset
))
1171 if (skb_cow(skb
, rt
->dst
.dev
->hard_header_len
))
1174 ip_vs_nat_icmp(skb
, pp
, cp
, 0);
1177 /* drop the old route when skb is not shared */
1179 skb_dst_set(skb
, &rt
->dst
);
1183 * Some IPv4 replies get local address from routes,
1184 * not from iph, so while we DNAT after routing
1185 * we need this second input/output route.
1187 if (!__ip_vs_reroute_locally(skb
))
1191 /* Another hack: avoid icmp_send in ip_fragment */
1194 IP_VS_XMIT_NAT(NFPROTO_IPV4
, skb
, cp
, local
);
1200 dst_link_failure(skb
);
1212 #ifdef CONFIG_IP_VS_IPV6
1214 ip_vs_icmp_xmit_v6(struct sk_buff
*skb
, struct ip_vs_conn
*cp
,
1215 struct ip_vs_protocol
*pp
, int offset
)
1217 struct rt6_info
*rt
; /* Route to the other host */
1224 /* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
1225 forwarded directly here, because there is no need to
1226 translate address/port back */
1227 if (IP_VS_FWD_METHOD(cp
) != IP_VS_CONN_F_MASQ
) {
1228 if (cp
->packet_xmit
)
1229 rc
= cp
->packet_xmit(skb
, cp
, pp
);
1232 /* do not touch skb anymore */
1233 atomic_inc(&cp
->in_pkts
);
1238 * mangle and send the packet here (only for VS/NAT)
1241 if (!(rt
= __ip_vs_get_out_rt_v6(skb
, cp
->dest
, &cp
->daddr
.in6
, NULL
,
1245 local
= __ip_vs_is_local_route6(rt
);
1247 * Avoid duplicate tuple in reply direction for NAT traffic
1248 * to local address when connection is sync-ed
1250 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1251 if (cp
->flags
& IP_VS_CONN_F_SYNC
&& local
) {
1252 enum ip_conntrack_info ctinfo
;
1253 struct nf_conn
*ct
= ct
= nf_ct_get(skb
, &ctinfo
);
1255 if (ct
&& !nf_ct_is_untracked(ct
)) {
1256 IP_VS_DBG(10, "%s(): "
1257 "stopping DNAT to local address %pI6\n",
1258 __func__
, &cp
->daddr
.in6
);
1264 /* From world but DNAT to loopback address? */
1265 if (local
&& skb
->dev
&& !(skb
->dev
->flags
& IFF_LOOPBACK
) &&
1266 ipv6_addr_type(&rt
->rt6i_dst
.addr
) & IPV6_ADDR_LOOPBACK
) {
1267 IP_VS_DBG(1, "%s(): "
1268 "stopping DNAT to loopback %pI6\n",
1269 __func__
, &cp
->daddr
.in6
);
1274 mtu
= dst_mtu(&rt
->dst
);
1275 if (skb
->len
> mtu
) {
1277 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
1279 skb
->dev
= net
->loopback_dev
;
1281 icmpv6_send(skb
, ICMPV6_PKT_TOOBIG
, 0, mtu
);
1282 IP_VS_DBG_RL("%s(): frag needed\n", __func__
);
1286 /* copy-on-write the packet before mangling it */
1287 if (!skb_make_writable(skb
, offset
))
1290 if (skb_cow(skb
, rt
->dst
.dev
->hard_header_len
))
1293 ip_vs_nat_icmp_v6(skb
, pp
, cp
, 0);
1295 if (!local
|| !skb
->dev
) {
1296 /* drop the old route when skb is not shared */
1298 skb_dst_set(skb
, &rt
->dst
);
1300 /* destined to loopback, do we need to change route? */
1301 dst_release(&rt
->dst
);
1304 /* Another hack: avoid icmp_send in ip_fragment */
1307 IP_VS_XMIT_NAT(NFPROTO_IPV6
, skb
, cp
, local
);
1313 dst_link_failure(skb
);
1321 dst_release(&rt
->dst
);
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