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>
47 IP_VS_RT_MODE_LOCAL = 1, /* Allow local dest */
48 IP_VS_RT_MODE_NON_LOCAL = 2, /* Allow non-local dest */
49 IP_VS_RT_MODE_RDR = 4, /* Allow redirect from remote daddr to
55 * Destination cache to speed up outgoing route lookup
58 __ip_vs_dst_set(struct ip_vs_dest *dest, u32 rtos, struct dst_entry *dst,
61 struct dst_entry *old_dst;
63 old_dst = dest->dst_cache;
64 dest->dst_cache = dst;
65 dest->dst_rtos = rtos;
66 dest->dst_cookie = dst_cookie;
70 static inline struct dst_entry *
71 __ip_vs_dst_check(struct ip_vs_dest *dest, u32 rtos)
73 struct dst_entry *dst = dest->dst_cache;
77 if ((dst->obsolete || rtos != dest->dst_rtos) &&
78 dst->ops->check(dst, dest->dst_cookie) == NULL) {
79 dest->dst_cache = NULL;
87 /* Get route to destination or remote server */
88 static struct rtable *
89 __ip_vs_get_out_rt(struct sk_buff *skb, struct ip_vs_dest *dest,
90 __be32 daddr, u32 rtos, int rt_mode)
92 struct net *net = dev_net(skb_dst(skb)->dev);
93 struct rtable *rt; /* Route to the other host */
94 struct rtable *ort; /* Original route */
98 spin_lock(&dest->dst_lock);
99 if (!(rt = (struct rtable *)
100 __ip_vs_dst_check(dest, rtos))) {
101 rt = ip_route_output(net, dest->addr.ip, 0, rtos, 0);
103 spin_unlock(&dest->dst_lock);
104 IP_VS_DBG_RL("ip_route_output error, dest: %pI4\n",
108 __ip_vs_dst_set(dest, rtos, dst_clone(&rt->dst), 0);
109 IP_VS_DBG(10, "new dst %pI4, refcnt=%d, rtos=%X\n",
111 atomic_read(&rt->dst.__refcnt), rtos);
113 spin_unlock(&dest->dst_lock);
115 rt = ip_route_output(net, daddr, 0, rtos, 0);
117 IP_VS_DBG_RL("ip_route_output error, dest: %pI4\n",
123 local = rt->rt_flags & RTCF_LOCAL;
124 if (!((local ? IP_VS_RT_MODE_LOCAL : IP_VS_RT_MODE_NON_LOCAL) &
126 IP_VS_DBG_RL("Stopping traffic to %s address, dest: %pI4\n",
127 (rt->rt_flags & RTCF_LOCAL) ?
128 "local":"non-local", &rt->rt_dst);
132 if (local && !(rt_mode & IP_VS_RT_MODE_RDR) &&
133 !((ort = skb_rtable(skb)) && ort->rt_flags & RTCF_LOCAL)) {
134 IP_VS_DBG_RL("Redirect from non-local address %pI4 to local "
135 "requires NAT method, dest: %pI4\n",
136 &ip_hdr(skb)->daddr, &rt->rt_dst);
140 if (unlikely(!local && ipv4_is_loopback(ip_hdr(skb)->saddr))) {
141 IP_VS_DBG_RL("Stopping traffic from loopback address %pI4 "
142 "to non-local address, dest: %pI4\n",
143 &ip_hdr(skb)->saddr, &rt->rt_dst);
151 /* Reroute packet to local IPv4 stack after DNAT */
153 __ip_vs_reroute_locally(struct sk_buff *skb)
155 struct rtable *rt = skb_rtable(skb);
156 struct net_device *dev = rt->dst.dev;
157 struct net *net = dev_net(dev);
158 struct iphdr *iph = ip_hdr(skb);
160 if (rt_is_input_route(rt)) {
161 unsigned long orefdst = skb->_skb_refdst;
163 if (ip_route_input(skb, iph->daddr, iph->saddr,
166 refdst_drop(orefdst);
168 struct flowi4 fl4 = {
171 .flowi4_tos = RT_TOS(iph->tos),
172 .flowi4_mark = skb->mark,
175 rt = ip_route_output_key(net, &fl4);
178 if (!(rt->rt_flags & RTCF_LOCAL)) {
182 /* Drop old route. */
184 skb_dst_set(skb, &rt->dst);
189 #ifdef CONFIG_IP_VS_IPV6
191 static inline int __ip_vs_is_local_route6(struct rt6_info *rt)
193 return rt->rt6i_dev && rt->rt6i_dev->flags & IFF_LOOPBACK;
196 static struct dst_entry *
197 __ip_vs_route_output_v6(struct net *net, struct in6_addr *daddr,
198 struct in6_addr *ret_saddr, int do_xfrm)
200 struct dst_entry *dst;
201 struct flowi6 fl6 = {
205 dst = ip6_route_output(net, NULL, &fl6);
210 if (ipv6_addr_any(&fl6.saddr) &&
211 ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
212 &fl6.daddr, 0, &fl6.saddr) < 0)
215 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
221 ipv6_addr_copy(ret_saddr, &fl6.saddr);
226 IP_VS_DBG_RL("ip6_route_output error, dest: %pI6\n", daddr);
231 * Get route to destination or remote server
232 * rt_mode: flags, &1=Allow local dest, &2=Allow non-local dest,
233 * &4=Allow redirect from remote daddr to local
235 static struct rt6_info *
236 __ip_vs_get_out_rt_v6(struct sk_buff *skb, struct ip_vs_dest *dest,
237 struct in6_addr *daddr, struct in6_addr *ret_saddr,
238 int do_xfrm, int rt_mode)
240 struct net *net = dev_net(skb_dst(skb)->dev);
241 struct rt6_info *rt; /* Route to the other host */
242 struct rt6_info *ort; /* Original route */
243 struct dst_entry *dst;
247 spin_lock(&dest->dst_lock);
248 rt = (struct rt6_info *)__ip_vs_dst_check(dest, 0);
252 dst = __ip_vs_route_output_v6(net, &dest->addr.in6,
256 spin_unlock(&dest->dst_lock);
259 rt = (struct rt6_info *) dst;
260 cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
261 __ip_vs_dst_set(dest, 0, dst_clone(&rt->dst), cookie);
262 IP_VS_DBG(10, "new dst %pI6, src %pI6, refcnt=%d\n",
263 &dest->addr.in6, &dest->dst_saddr,
264 atomic_read(&rt->dst.__refcnt));
267 ipv6_addr_copy(ret_saddr, &dest->dst_saddr);
268 spin_unlock(&dest->dst_lock);
270 dst = __ip_vs_route_output_v6(net, daddr, ret_saddr, do_xfrm);
273 rt = (struct rt6_info *) dst;
276 local = __ip_vs_is_local_route6(rt);
277 if (!((local ? 1 : 2) & rt_mode)) {
278 IP_VS_DBG_RL("Stopping traffic to %s address, dest: %pI6\n",
279 local ? "local":"non-local", daddr);
280 dst_release(&rt->dst);
283 if (local && !(rt_mode & 4) &&
284 !((ort = (struct rt6_info *) skb_dst(skb)) &&
285 __ip_vs_is_local_route6(ort))) {
286 IP_VS_DBG_RL("Redirect from non-local address %pI6 to local "
287 "requires NAT method, dest: %pI6\n",
288 &ipv6_hdr(skb)->daddr, daddr);
289 dst_release(&rt->dst);
292 if (unlikely(!local && (!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
293 ipv6_addr_type(&ipv6_hdr(skb)->saddr) &
294 IPV6_ADDR_LOOPBACK)) {
295 IP_VS_DBG_RL("Stopping traffic from loopback address %pI6 "
296 "to non-local address, dest: %pI6\n",
297 &ipv6_hdr(skb)->saddr, daddr);
298 dst_release(&rt->dst);
308 * Release dest->dst_cache before a dest is removed
311 ip_vs_dst_reset(struct ip_vs_dest *dest)
313 struct dst_entry *old_dst;
315 old_dst = dest->dst_cache;
316 dest->dst_cache = NULL;
317 dst_release(old_dst);
320 #define IP_VS_XMIT_TUNNEL(skb, cp) \
322 int __ret = NF_ACCEPT; \
324 (skb)->ipvs_property = 1; \
325 if (unlikely((cp)->flags & IP_VS_CONN_F_NFCT)) \
326 __ret = ip_vs_confirm_conntrack(skb, cp); \
327 if (__ret == NF_ACCEPT) { \
329 skb_forward_csum(skb); \
334 #define IP_VS_XMIT_NAT(pf, skb, cp, local) \
336 (skb)->ipvs_property = 1; \
337 if (likely(!((cp)->flags & IP_VS_CONN_F_NFCT))) \
338 ip_vs_notrack(skb); \
340 ip_vs_update_conntrack(skb, cp, 1); \
343 skb_forward_csum(skb); \
344 NF_HOOK(pf, NF_INET_LOCAL_OUT, (skb), NULL, \
345 skb_dst(skb)->dev, dst_output); \
348 #define IP_VS_XMIT(pf, skb, cp, local) \
350 (skb)->ipvs_property = 1; \
351 if (likely(!((cp)->flags & IP_VS_CONN_F_NFCT))) \
352 ip_vs_notrack(skb); \
355 skb_forward_csum(skb); \
356 NF_HOOK(pf, NF_INET_LOCAL_OUT, (skb), NULL, \
357 skb_dst(skb)->dev, dst_output); \
362 * NULL transmitter (do nothing except return NF_ACCEPT)
365 ip_vs_null_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
366 struct ip_vs_protocol *pp)
368 /* we do not touch skb and do not need pskb ptr */
369 IP_VS_XMIT(NFPROTO_IPV4, skb, cp, 1);
375 * Let packets bypass the destination when the destination is not
376 * available, it may be only used in transparent cache cluster.
379 ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
380 struct ip_vs_protocol *pp)
382 struct rtable *rt; /* Route to the other host */
383 struct iphdr *iph = ip_hdr(skb);
388 if (!(rt = __ip_vs_get_out_rt(skb, NULL, iph->daddr, RT_TOS(iph->tos),
389 IP_VS_RT_MODE_NON_LOCAL)))
393 mtu = dst_mtu(&rt->dst);
394 if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF)) &&
397 icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
398 IP_VS_DBG_RL("%s(): frag needed\n", __func__);
403 * Call ip_send_check because we are not sure it is called
404 * after ip_defrag. Is copy-on-write needed?
406 if (unlikely((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)) {
410 ip_send_check(ip_hdr(skb));
414 skb_dst_set(skb, &rt->dst);
416 /* Another hack: avoid icmp_send in ip_fragment */
419 IP_VS_XMIT(NFPROTO_IPV4, skb, cp, 0);
425 dst_link_failure(skb);
432 #ifdef CONFIG_IP_VS_IPV6
434 ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
435 struct ip_vs_protocol *pp)
437 struct rt6_info *rt; /* Route to the other host */
438 struct ipv6hdr *iph = ipv6_hdr(skb);
443 if (!(rt = __ip_vs_get_out_rt_v6(skb, NULL, &iph->daddr, NULL, 0, 2)))
447 mtu = dst_mtu(&rt->dst);
448 if (skb->len > mtu && !skb_is_gso(skb)) {
450 struct net *net = dev_net(skb_dst(skb)->dev);
452 skb->dev = net->loopback_dev;
454 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
455 dst_release(&rt->dst);
456 IP_VS_DBG_RL("%s(): frag needed\n", __func__);
461 * Call ip_send_check because we are not sure it is called
462 * after ip_defrag. Is copy-on-write needed?
464 skb = skb_share_check(skb, GFP_ATOMIC);
465 if (unlikely(skb == NULL)) {
466 dst_release(&rt->dst);
472 skb_dst_set(skb, &rt->dst);
474 /* Another hack: avoid icmp_send in ip_fragment */
477 IP_VS_XMIT(NFPROTO_IPV6, skb, cp, 0);
483 dst_link_failure(skb);
492 * NAT transmitter (only for outside-to-inside nat forwarding)
493 * Not used for related ICMP
496 ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
497 struct ip_vs_protocol *pp)
499 struct rtable *rt; /* Route to the other host */
501 struct iphdr *iph = ip_hdr(skb);
506 /* check if it is a connection of no-client-port */
507 if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT)) {
509 p = skb_header_pointer(skb, iph->ihl*4, sizeof(_pt), &_pt);
512 ip_vs_conn_fill_cport(cp, *p);
513 IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p));
516 if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
518 IP_VS_RT_MODE_LOCAL |
519 IP_VS_RT_MODE_NON_LOCAL |
522 local = rt->rt_flags & RTCF_LOCAL;
524 * Avoid duplicate tuple in reply direction for NAT traffic
525 * to local address when connection is sync-ed
527 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
528 if (cp->flags & IP_VS_CONN_F_SYNC && local) {
529 enum ip_conntrack_info ctinfo;
530 struct nf_conn *ct = ct = nf_ct_get(skb, &ctinfo);
532 if (ct && !nf_ct_is_untracked(ct)) {
533 IP_VS_DBG_RL_PKT(10, AF_INET, pp, skb, 0,
535 "stopping DNAT to local address");
541 /* From world but DNAT to loopback address? */
542 if (local && ipv4_is_loopback(rt->rt_dst) &&
543 rt_is_input_route(skb_rtable(skb))) {
544 IP_VS_DBG_RL_PKT(1, AF_INET, pp, skb, 0, "ip_vs_nat_xmit(): "
545 "stopping DNAT to loopback address");
550 mtu = dst_mtu(&rt->dst);
551 if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF)) &&
553 icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
554 IP_VS_DBG_RL_PKT(0, AF_INET, pp, skb, 0,
555 "ip_vs_nat_xmit(): frag needed for");
559 /* copy-on-write the packet before mangling it */
560 if (!skb_make_writable(skb, sizeof(struct iphdr)))
563 if (skb_cow(skb, rt->dst.dev->hard_header_len))
566 /* mangle the packet */
567 if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp))
569 ip_hdr(skb)->daddr = cp->daddr.ip;
570 ip_send_check(ip_hdr(skb));
575 skb_dst_set(skb, &rt->dst);
579 * Some IPv4 replies get local address from routes,
580 * not from iph, so while we DNAT after routing
581 * we need this second input/output route.
583 if (!__ip_vs_reroute_locally(skb))
587 IP_VS_DBG_PKT(10, AF_INET, pp, skb, 0, "After DNAT");
589 /* FIXME: when application helper enlarges the packet and the length
590 is larger than the MTU of outgoing device, there will be still
593 /* Another hack: avoid icmp_send in ip_fragment */
596 IP_VS_XMIT_NAT(NFPROTO_IPV4, skb, cp, local);
602 dst_link_failure(skb);
612 #ifdef CONFIG_IP_VS_IPV6
614 ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
615 struct ip_vs_protocol *pp)
617 struct rt6_info *rt; /* Route to the other host */
623 /* check if it is a connection of no-client-port */
624 if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT)) {
626 p = skb_header_pointer(skb, sizeof(struct ipv6hdr),
630 ip_vs_conn_fill_cport(cp, *p);
631 IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p));
634 if (!(rt = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6, NULL,
637 local = __ip_vs_is_local_route6(rt);
639 * Avoid duplicate tuple in reply direction for NAT traffic
640 * to local address when connection is sync-ed
642 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
643 if (cp->flags & IP_VS_CONN_F_SYNC && local) {
644 enum ip_conntrack_info ctinfo;
645 struct nf_conn *ct = ct = nf_ct_get(skb, &ctinfo);
647 if (ct && !nf_ct_is_untracked(ct)) {
648 IP_VS_DBG_RL_PKT(10, AF_INET6, pp, skb, 0,
649 "ip_vs_nat_xmit_v6(): "
650 "stopping DNAT to local address");
656 /* From world but DNAT to loopback address? */
657 if (local && skb->dev && !(skb->dev->flags & IFF_LOOPBACK) &&
658 ipv6_addr_type(&rt->rt6i_dst.addr) & IPV6_ADDR_LOOPBACK) {
659 IP_VS_DBG_RL_PKT(1, AF_INET6, pp, skb, 0,
660 "ip_vs_nat_xmit_v6(): "
661 "stopping DNAT to loopback address");
666 mtu = dst_mtu(&rt->dst);
667 if (skb->len > mtu && !skb_is_gso(skb)) {
669 struct net *net = dev_net(skb_dst(skb)->dev);
671 skb->dev = net->loopback_dev;
673 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
674 IP_VS_DBG_RL_PKT(0, AF_INET6, pp, skb, 0,
675 "ip_vs_nat_xmit_v6(): frag needed for");
679 /* copy-on-write the packet before mangling it */
680 if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
683 if (skb_cow(skb, rt->dst.dev->hard_header_len))
686 /* mangle the packet */
687 if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp))
689 ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &cp->daddr.in6);
691 if (!local || !skb->dev) {
692 /* drop the old route when skb is not shared */
694 skb_dst_set(skb, &rt->dst);
696 /* destined to loopback, do we need to change route? */
697 dst_release(&rt->dst);
700 IP_VS_DBG_PKT(10, AF_INET6, pp, skb, 0, "After DNAT");
702 /* FIXME: when application helper enlarges the packet and the length
703 is larger than the MTU of outgoing device, there will be still
706 /* Another hack: avoid icmp_send in ip_fragment */
709 IP_VS_XMIT_NAT(NFPROTO_IPV6, skb, cp, local);
715 dst_link_failure(skb);
721 dst_release(&rt->dst);
728 * IP Tunneling transmitter
730 * This function encapsulates the packet in a new IP packet, its
731 * destination will be set to cp->daddr. Most code of this function
732 * is taken from ipip.c.
734 * It is used in VS/TUN cluster. The load balancer selects a real
735 * server from a cluster based on a scheduling algorithm,
736 * encapsulates the request packet and forwards it to the selected
737 * server. For example, all real servers are configured with
738 * "ifconfig tunl0 <Virtual IP Address> up". When the server receives
739 * the encapsulated packet, it will decapsulate the packet, processe
740 * the request and return the response packets directly to the client
741 * without passing the load balancer. This can greatly increase the
742 * scalability of virtual server.
744 * Used for ANY protocol
747 ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
748 struct ip_vs_protocol *pp)
750 struct rtable *rt; /* Route to the other host */
751 struct net_device *tdev; /* Device to other host */
752 struct iphdr *old_iph = ip_hdr(skb);
753 u8 tos = old_iph->tos;
754 __be16 df = old_iph->frag_off;
755 struct iphdr *iph; /* Our new IP header */
756 unsigned int max_headroom; /* The extra header space needed */
762 if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
763 RT_TOS(tos), IP_VS_RT_MODE_LOCAL |
764 IP_VS_RT_MODE_NON_LOCAL)))
766 if (rt->rt_flags & RTCF_LOCAL) {
768 IP_VS_XMIT(NFPROTO_IPV4, skb, cp, 1);
773 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
775 IP_VS_DBG_RL("%s(): mtu less than 68\n", __func__);
779 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
781 df |= (old_iph->frag_off & htons(IP_DF));
783 if ((old_iph->frag_off & htons(IP_DF) &&
784 mtu < ntohs(old_iph->tot_len) && !skb_is_gso(skb))) {
785 icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
786 IP_VS_DBG_RL("%s(): frag needed\n", __func__);
791 * Okay, now see if we can stuff it in the buffer as-is.
793 max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr);
795 if (skb_headroom(skb) < max_headroom
796 || skb_cloned(skb) || skb_shared(skb)) {
797 struct sk_buff *new_skb =
798 skb_realloc_headroom(skb, max_headroom);
802 IP_VS_ERR_RL("%s(): no memory\n", __func__);
807 old_iph = ip_hdr(skb);
810 skb->transport_header = skb->network_header;
812 /* fix old IP header checksum */
813 ip_send_check(old_iph);
815 skb_push(skb, sizeof(struct iphdr));
816 skb_reset_network_header(skb);
817 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
821 skb_dst_set(skb, &rt->dst);
824 * Push down and install the IPIP header.
828 iph->ihl = sizeof(struct iphdr)>>2;
830 iph->protocol = IPPROTO_IPIP;
832 iph->daddr = rt->rt_dst;
833 iph->saddr = rt->rt_src;
834 iph->ttl = old_iph->ttl;
835 ip_select_ident(iph, &rt->dst, NULL);
837 /* Another hack: avoid icmp_send in ip_fragment */
840 ret = IP_VS_XMIT_TUNNEL(skb, cp);
841 if (ret == NF_ACCEPT)
843 else if (ret == NF_DROP)
851 dst_link_failure(skb);
861 #ifdef CONFIG_IP_VS_IPV6
863 ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
864 struct ip_vs_protocol *pp)
866 struct rt6_info *rt; /* Route to the other host */
867 struct in6_addr saddr; /* Source for tunnel */
868 struct net_device *tdev; /* Device to other host */
869 struct ipv6hdr *old_iph = ipv6_hdr(skb);
870 struct ipv6hdr *iph; /* Our new IP header */
871 unsigned int max_headroom; /* The extra header space needed */
877 if (!(rt = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6,
880 if (__ip_vs_is_local_route6(rt)) {
881 dst_release(&rt->dst);
882 IP_VS_XMIT(NFPROTO_IPV6, skb, cp, 1);
887 mtu = dst_mtu(&rt->dst) - sizeof(struct ipv6hdr);
888 if (mtu < IPV6_MIN_MTU) {
889 IP_VS_DBG_RL("%s(): mtu less than %d\n", __func__,
894 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
896 if (mtu < ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr) &&
899 struct net *net = dev_net(skb_dst(skb)->dev);
901 skb->dev = net->loopback_dev;
903 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
904 IP_VS_DBG_RL("%s(): frag needed\n", __func__);
909 * Okay, now see if we can stuff it in the buffer as-is.
911 max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct ipv6hdr);
913 if (skb_headroom(skb) < max_headroom
914 || skb_cloned(skb) || skb_shared(skb)) {
915 struct sk_buff *new_skb =
916 skb_realloc_headroom(skb, max_headroom);
918 dst_release(&rt->dst);
920 IP_VS_ERR_RL("%s(): no memory\n", __func__);
925 old_iph = ipv6_hdr(skb);
928 skb->transport_header = skb->network_header;
930 skb_push(skb, sizeof(struct ipv6hdr));
931 skb_reset_network_header(skb);
932 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
936 skb_dst_set(skb, &rt->dst);
939 * Push down and install the IPIP header.
943 iph->nexthdr = IPPROTO_IPV6;
944 iph->payload_len = old_iph->payload_len;
945 be16_add_cpu(&iph->payload_len, sizeof(*old_iph));
946 iph->priority = old_iph->priority;
947 memset(&iph->flow_lbl, 0, sizeof(iph->flow_lbl));
948 ipv6_addr_copy(&iph->daddr, &cp->daddr.in6);
949 ipv6_addr_copy(&iph->saddr, &saddr);
950 iph->hop_limit = old_iph->hop_limit;
952 /* Another hack: avoid icmp_send in ip_fragment */
955 ret = IP_VS_XMIT_TUNNEL(skb, cp);
956 if (ret == NF_ACCEPT)
958 else if (ret == NF_DROP)
966 dst_link_failure(skb);
972 dst_release(&rt->dst);
979 * Direct Routing transmitter
980 * Used for ANY protocol
983 ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
984 struct ip_vs_protocol *pp)
986 struct rtable *rt; /* Route to the other host */
987 struct iphdr *iph = ip_hdr(skb);
992 if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
994 IP_VS_RT_MODE_LOCAL |
995 IP_VS_RT_MODE_NON_LOCAL)))
997 if (rt->rt_flags & RTCF_LOCAL) {
999 IP_VS_XMIT(NFPROTO_IPV4, skb, cp, 1);
1003 mtu = dst_mtu(&rt->dst);
1004 if ((iph->frag_off & htons(IP_DF)) && skb->len > mtu &&
1006 icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
1008 IP_VS_DBG_RL("%s(): frag needed\n", __func__);
1013 * Call ip_send_check because we are not sure it is called
1014 * after ip_defrag. Is copy-on-write needed?
1016 if (unlikely((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)) {
1020 ip_send_check(ip_hdr(skb));
1022 /* drop old route */
1024 skb_dst_set(skb, &rt->dst);
1026 /* Another hack: avoid icmp_send in ip_fragment */
1029 IP_VS_XMIT(NFPROTO_IPV4, skb, cp, 0);
1035 dst_link_failure(skb);
1042 #ifdef CONFIG_IP_VS_IPV6
1044 ip_vs_dr_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
1045 struct ip_vs_protocol *pp)
1047 struct rt6_info *rt; /* Route to the other host */
1052 if (!(rt = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6, NULL,
1055 if (__ip_vs_is_local_route6(rt)) {
1056 dst_release(&rt->dst);
1057 IP_VS_XMIT(NFPROTO_IPV6, skb, cp, 1);
1061 mtu = dst_mtu(&rt->dst);
1062 if (skb->len > mtu) {
1064 struct net *net = dev_net(skb_dst(skb)->dev);
1066 skb->dev = net->loopback_dev;
1068 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1069 dst_release(&rt->dst);
1070 IP_VS_DBG_RL("%s(): frag needed\n", __func__);
1075 * Call ip_send_check because we are not sure it is called
1076 * after ip_defrag. Is copy-on-write needed?
1078 skb = skb_share_check(skb, GFP_ATOMIC);
1079 if (unlikely(skb == NULL)) {
1080 dst_release(&rt->dst);
1084 /* drop old route */
1086 skb_dst_set(skb, &rt->dst);
1088 /* Another hack: avoid icmp_send in ip_fragment */
1091 IP_VS_XMIT(NFPROTO_IPV6, skb, cp, 0);
1097 dst_link_failure(skb);
1107 * ICMP packet transmitter
1108 * called by the ip_vs_in_icmp
1111 ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
1112 struct ip_vs_protocol *pp, int offset)
1114 struct rtable *rt; /* Route to the other host */
1121 /* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
1122 forwarded directly here, because there is no need to
1123 translate address/port back */
1124 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
1125 if (cp->packet_xmit)
1126 rc = cp->packet_xmit(skb, cp, pp);
1129 /* do not touch skb anymore */
1130 atomic_inc(&cp->in_pkts);
1135 * mangle and send the packet here (only for VS/NAT)
1138 if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
1139 RT_TOS(ip_hdr(skb)->tos),
1140 IP_VS_RT_MODE_LOCAL |
1141 IP_VS_RT_MODE_NON_LOCAL |
1142 IP_VS_RT_MODE_RDR)))
1144 local = rt->rt_flags & RTCF_LOCAL;
1147 * Avoid duplicate tuple in reply direction for NAT traffic
1148 * to local address when connection is sync-ed
1150 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1151 if (cp->flags & IP_VS_CONN_F_SYNC && local) {
1152 enum ip_conntrack_info ctinfo;
1153 struct nf_conn *ct = ct = nf_ct_get(skb, &ctinfo);
1155 if (ct && !nf_ct_is_untracked(ct)) {
1156 IP_VS_DBG(10, "%s(): "
1157 "stopping DNAT to local address %pI4\n",
1158 __func__, &cp->daddr.ip);
1164 /* From world but DNAT to loopback address? */
1165 if (local && ipv4_is_loopback(rt->rt_dst) &&
1166 rt_is_input_route(skb_rtable(skb))) {
1167 IP_VS_DBG(1, "%s(): "
1168 "stopping DNAT to loopback %pI4\n",
1169 __func__, &cp->daddr.ip);
1174 mtu = dst_mtu(&rt->dst);
1175 if ((skb->len > mtu) && (ip_hdr(skb)->frag_off & htons(IP_DF)) &&
1177 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
1178 IP_VS_DBG_RL("%s(): frag needed\n", __func__);
1182 /* copy-on-write the packet before mangling it */
1183 if (!skb_make_writable(skb, offset))
1186 if (skb_cow(skb, rt->dst.dev->hard_header_len))
1189 ip_vs_nat_icmp(skb, pp, cp, 0);
1192 /* drop the old route when skb is not shared */
1194 skb_dst_set(skb, &rt->dst);
1198 * Some IPv4 replies get local address from routes,
1199 * not from iph, so while we DNAT after routing
1200 * we need this second input/output route.
1202 if (!__ip_vs_reroute_locally(skb))
1206 /* Another hack: avoid icmp_send in ip_fragment */
1209 IP_VS_XMIT_NAT(NFPROTO_IPV4, skb, cp, local);
1215 dst_link_failure(skb);
1227 #ifdef CONFIG_IP_VS_IPV6
1229 ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
1230 struct ip_vs_protocol *pp, int offset)
1232 struct rt6_info *rt; /* Route to the other host */
1239 /* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
1240 forwarded directly here, because there is no need to
1241 translate address/port back */
1242 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
1243 if (cp->packet_xmit)
1244 rc = cp->packet_xmit(skb, cp, pp);
1247 /* do not touch skb anymore */
1248 atomic_inc(&cp->in_pkts);
1253 * mangle and send the packet here (only for VS/NAT)
1256 if (!(rt = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6, NULL,
1260 local = __ip_vs_is_local_route6(rt);
1262 * Avoid duplicate tuple in reply direction for NAT traffic
1263 * to local address when connection is sync-ed
1265 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1266 if (cp->flags & IP_VS_CONN_F_SYNC && local) {
1267 enum ip_conntrack_info ctinfo;
1268 struct nf_conn *ct = ct = nf_ct_get(skb, &ctinfo);
1270 if (ct && !nf_ct_is_untracked(ct)) {
1271 IP_VS_DBG(10, "%s(): "
1272 "stopping DNAT to local address %pI6\n",
1273 __func__, &cp->daddr.in6);
1279 /* From world but DNAT to loopback address? */
1280 if (local && skb->dev && !(skb->dev->flags & IFF_LOOPBACK) &&
1281 ipv6_addr_type(&rt->rt6i_dst.addr) & IPV6_ADDR_LOOPBACK) {
1282 IP_VS_DBG(1, "%s(): "
1283 "stopping DNAT to loopback %pI6\n",
1284 __func__, &cp->daddr.in6);
1289 mtu = dst_mtu(&rt->dst);
1290 if (skb->len > mtu && !skb_is_gso(skb)) {
1292 struct net *net = dev_net(skb_dst(skb)->dev);
1294 skb->dev = net->loopback_dev;
1296 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1297 IP_VS_DBG_RL("%s(): frag needed\n", __func__);
1301 /* copy-on-write the packet before mangling it */
1302 if (!skb_make_writable(skb, offset))
1305 if (skb_cow(skb, rt->dst.dev->hard_header_len))
1308 ip_vs_nat_icmp_v6(skb, pp, cp, 0);
1310 if (!local || !skb->dev) {
1311 /* drop the old route when skb is not shared */
1313 skb_dst_set(skb, &rt->dst);
1315 /* destined to loopback, do we need to change route? */
1316 dst_release(&rt->dst);
1319 /* Another hack: avoid icmp_send in ip_fragment */
1322 IP_VS_XMIT_NAT(NFPROTO_IPV6, skb, cp, local);
1328 dst_link_failure(skb);
1336 dst_release(&rt->dst);