--- /dev/null
+/*
+ * ip_vs_xmit.c: various packet transmitters for IPVS
+ *
+ * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
+ * Julian Anastasov <ja@ssi.bg>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Changes:
+ *
+ * Description of forwarding methods:
+ * - all transmitters are called from LOCAL_IN (remote clients) and
+ * LOCAL_OUT (local clients) but for ICMP can be called from FORWARD
+ * - not all connections have destination server, for example,
+ * connections in backup server when fwmark is used
+ * - bypass connections use daddr from packet
+ * - we can use dst without ref while sending in RCU section, we use
+ * ref when returning NF_ACCEPT for NAT-ed packet via loopback
+ * LOCAL_OUT rules:
+ * - skb->dev is NULL, skb->protocol is not set (both are set in POST_ROUTING)
+ * - skb->pkt_type is not set yet
+ * - the only place where we can see skb->sk != NULL
+ */
+
+#define KMSG_COMPONENT "IPVS"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/tcp.h> /* for tcphdr */
+#include <net/ip.h>
+#include <net/tcp.h> /* for csum_tcpudp_magic */
+#include <net/udp.h>
+#include <net/icmp.h> /* for icmp_send */
+#include <net/route.h> /* for ip_route_output */
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/ip_tunnels.h>
+#include <net/addrconf.h>
+#include <linux/icmpv6.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+
+#include <net/ip_vs.h>
+
+enum {
+ IP_VS_RT_MODE_LOCAL = 1, /* Allow local dest */
+ IP_VS_RT_MODE_NON_LOCAL = 2, /* Allow non-local dest */
+ IP_VS_RT_MODE_RDR = 4, /* Allow redirect from remote daddr to
+ * local
+ */
+ IP_VS_RT_MODE_CONNECT = 8, /* Always bind route to saddr */
+ IP_VS_RT_MODE_KNOWN_NH = 16,/* Route via remote addr */
+ IP_VS_RT_MODE_TUNNEL = 32,/* Tunnel mode */
+};
+
+static inline struct ip_vs_dest_dst *ip_vs_dest_dst_alloc(void)
+{
+ return kmalloc(sizeof(struct ip_vs_dest_dst), GFP_ATOMIC);
+}
+
+static inline void ip_vs_dest_dst_free(struct ip_vs_dest_dst *dest_dst)
+{
+ kfree(dest_dst);
+}
+
+/*
+ * Destination cache to speed up outgoing route lookup
+ */
+static inline void
+__ip_vs_dst_set(struct ip_vs_dest *dest, struct ip_vs_dest_dst *dest_dst,
+ struct dst_entry *dst, u32 dst_cookie)
+{
+ struct ip_vs_dest_dst *old;
+
+ old = rcu_dereference_protected(dest->dest_dst,
+ lockdep_is_held(&dest->dst_lock));
+
+ if (dest_dst) {
+ dest_dst->dst_cache = dst;
+ dest_dst->dst_cookie = dst_cookie;
+ }
+ rcu_assign_pointer(dest->dest_dst, dest_dst);
+
+ if (old)
+ call_rcu(&old->rcu_head, ip_vs_dest_dst_rcu_free);
+}
+
+static inline struct ip_vs_dest_dst *
+__ip_vs_dst_check(struct ip_vs_dest *dest)
+{
+ struct ip_vs_dest_dst *dest_dst = rcu_dereference(dest->dest_dst);
+ struct dst_entry *dst;
+
+ if (!dest_dst)
+ return NULL;
+ dst = dest_dst->dst_cache;
+ if (dst->obsolete &&
+ dst->ops->check(dst, dest_dst->dst_cookie) == NULL)
+ return NULL;
+ return dest_dst;
+}
+
+static inline bool
+__mtu_check_toobig_v6(const struct sk_buff *skb, u32 mtu)
+{
+ if (IP6CB(skb)->frag_max_size) {
+ /* frag_max_size tell us that, this packet have been
+ * defragmented by netfilter IPv6 conntrack module.
+ */
+ if (IP6CB(skb)->frag_max_size > mtu)
+ return true; /* largest fragment violate MTU */
+ }
+ else if (skb->len > mtu && !skb_is_gso(skb)) {
+ return true; /* Packet size violate MTU size */
+ }
+ return false;
+}
+
+/* Get route to daddr, update *saddr, optionally bind route to saddr */
+static struct rtable *do_output_route4(struct net *net, __be32 daddr,
+ int rt_mode, __be32 *saddr)
+{
+ struct flowi4 fl4;
+ struct rtable *rt;
+ int loop = 0;
+
+ memset(&fl4, 0, sizeof(fl4));
+ fl4.daddr = daddr;
+ fl4.saddr = (rt_mode & IP_VS_RT_MODE_CONNECT) ? *saddr : 0;
+ fl4.flowi4_flags = (rt_mode & IP_VS_RT_MODE_KNOWN_NH) ?
+ FLOWI_FLAG_KNOWN_NH : 0;
+
+retry:
+ rt = ip_route_output_key(net, &fl4);
+ if (IS_ERR(rt)) {
+ /* Invalid saddr ? */
+ if (PTR_ERR(rt) == -EINVAL && *saddr &&
+ rt_mode & IP_VS_RT_MODE_CONNECT && !loop) {
+ *saddr = 0;
+ flowi4_update_output(&fl4, 0, 0, daddr, 0);
+ goto retry;
+ }
+ IP_VS_DBG_RL("ip_route_output error, dest: %pI4\n", &daddr);
+ return NULL;
+ } else if (!*saddr && rt_mode & IP_VS_RT_MODE_CONNECT && fl4.saddr) {
+ ip_rt_put(rt);
+ *saddr = fl4.saddr;
+ flowi4_update_output(&fl4, 0, 0, daddr, fl4.saddr);
+ loop++;
+ goto retry;
+ }
+ *saddr = fl4.saddr;
+ return rt;
+}
+
+#ifdef CONFIG_IP_VS_IPV6
+static inline int __ip_vs_is_local_route6(struct rt6_info *rt)
+{
+ return rt->dst.dev && rt->dst.dev->flags & IFF_LOOPBACK;
+}
+#endif
+
+static inline bool crosses_local_route_boundary(int skb_af, struct sk_buff *skb,
+ int rt_mode,
+ bool new_rt_is_local)
+{
+ bool rt_mode_allow_local = !!(rt_mode & IP_VS_RT_MODE_LOCAL);
+ bool rt_mode_allow_non_local = !!(rt_mode & IP_VS_RT_MODE_LOCAL);
+ bool rt_mode_allow_redirect = !!(rt_mode & IP_VS_RT_MODE_RDR);
+ bool source_is_loopback;
+ bool old_rt_is_local;
+
+#ifdef CONFIG_IP_VS_IPV6
+ if (skb_af == AF_INET6) {
+ int addr_type = ipv6_addr_type(&ipv6_hdr(skb)->saddr);
+
+ source_is_loopback =
+ (!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
+ (addr_type & IPV6_ADDR_LOOPBACK);
+ old_rt_is_local = __ip_vs_is_local_route6(
+ (struct rt6_info *)skb_dst(skb));
+ } else
+#endif
+ {
+ source_is_loopback = ipv4_is_loopback(ip_hdr(skb)->saddr);
+ old_rt_is_local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
+ }
+
+ if (unlikely(new_rt_is_local)) {
+ if (!rt_mode_allow_local)
+ return true;
+ if (!rt_mode_allow_redirect && !old_rt_is_local)
+ return true;
+ } else {
+ if (!rt_mode_allow_non_local)
+ return true;
+ if (source_is_loopback)
+ return true;
+ }
+ return false;
+}
+
+static inline void maybe_update_pmtu(int skb_af, struct sk_buff *skb, int mtu)
+{
+ struct sock *sk = skb->sk;
+ struct rtable *ort = skb_rtable(skb);
+
+ if (!skb->dev && sk && sk_fullsock(sk))
+ ort->dst.ops->update_pmtu(&ort->dst, sk, NULL, mtu);
+}
+
+static inline bool ensure_mtu_is_adequate(int skb_af, int rt_mode,
+ struct ip_vs_iphdr *ipvsh,
+ struct sk_buff *skb, int mtu)
+{
+#ifdef CONFIG_IP_VS_IPV6
+ if (skb_af == AF_INET6) {
+ struct net *net = dev_net(skb_dst(skb)->dev);
+
+ if (unlikely(__mtu_check_toobig_v6(skb, mtu))) {
+ if (!skb->dev)
+ skb->dev = net->loopback_dev;
+ /* only send ICMP too big on first fragment */
+ if (!ipvsh->fragoffs)
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ IP_VS_DBG(1, "frag needed for %pI6c\n",
+ &ipv6_hdr(skb)->saddr);
+ return false;
+ }
+ } else
+#endif
+ {
+ struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
+
+ /* If we're going to tunnel the packet and pmtu discovery
+ * is disabled, we'll just fragment it anyway
+ */
+ if ((rt_mode & IP_VS_RT_MODE_TUNNEL) && !sysctl_pmtu_disc(ipvs))
+ return true;
+
+ if (unlikely(ip_hdr(skb)->frag_off & htons(IP_DF) &&
+ skb->len > mtu && !skb_is_gso(skb))) {
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+ htonl(mtu));
+ IP_VS_DBG(1, "frag needed for %pI4\n",
+ &ip_hdr(skb)->saddr);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/* Get route to destination or remote server */
+static int
+__ip_vs_get_out_rt(int skb_af, struct sk_buff *skb, struct ip_vs_dest *dest,
+ __be32 daddr, int rt_mode, __be32 *ret_saddr,
+ struct ip_vs_iphdr *ipvsh)
+{
+ struct net *net = dev_net(skb_dst(skb)->dev);
+ struct ip_vs_dest_dst *dest_dst;
+ struct rtable *rt; /* Route to the other host */
+ int mtu;
+ int local, noref = 1;
+
+ if (dest) {
+ dest_dst = __ip_vs_dst_check(dest);
+ if (likely(dest_dst))
+ rt = (struct rtable *) dest_dst->dst_cache;
+ else {
+ dest_dst = ip_vs_dest_dst_alloc();
+ spin_lock_bh(&dest->dst_lock);
+ if (!dest_dst) {
+ __ip_vs_dst_set(dest, NULL, NULL, 0);
+ spin_unlock_bh(&dest->dst_lock);
+ goto err_unreach;
+ }
+ rt = do_output_route4(net, dest->addr.ip, rt_mode,
+ &dest_dst->dst_saddr.ip);
+ if (!rt) {
+ __ip_vs_dst_set(dest, NULL, NULL, 0);
+ spin_unlock_bh(&dest->dst_lock);
+ ip_vs_dest_dst_free(dest_dst);
+ goto err_unreach;
+ }
+ __ip_vs_dst_set(dest, dest_dst, &rt->dst, 0);
+ spin_unlock_bh(&dest->dst_lock);
+ IP_VS_DBG(10, "new dst %pI4, src %pI4, refcnt=%d\n",
+ &dest->addr.ip, &dest_dst->dst_saddr.ip,
+ atomic_read(&rt->dst.__refcnt));
+ }
+ if (ret_saddr)
+ *ret_saddr = dest_dst->dst_saddr.ip;
+ } else {
+ __be32 saddr = htonl(INADDR_ANY);
+
+ noref = 0;
+
+ /* For such unconfigured boxes avoid many route lookups
+ * for performance reasons because we do not remember saddr
+ */
+ rt_mode &= ~IP_VS_RT_MODE_CONNECT;
+ rt = do_output_route4(net, daddr, rt_mode, &saddr);
+ if (!rt)
+ goto err_unreach;
+ if (ret_saddr)
+ *ret_saddr = saddr;
+ }
+
+ local = (rt->rt_flags & RTCF_LOCAL) ? 1 : 0;
+ if (unlikely(crosses_local_route_boundary(skb_af, skb, rt_mode,
+ local))) {
+ IP_VS_DBG_RL("We are crossing local and non-local addresses"
+ " daddr=%pI4\n", &daddr);
+ goto err_put;
+ }
+
+ if (unlikely(local)) {
+ /* skb to local stack, preserve old route */
+ if (!noref)
+ ip_rt_put(rt);
+ return local;
+ }
+
+ if (likely(!(rt_mode & IP_VS_RT_MODE_TUNNEL))) {
+ mtu = dst_mtu(&rt->dst);
+ } else {
+ mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
+ if (mtu < 68) {
+ IP_VS_DBG_RL("%s(): mtu less than 68\n", __func__);
+ goto err_put;
+ }
+ maybe_update_pmtu(skb_af, skb, mtu);
+ }
+
+ if (!ensure_mtu_is_adequate(skb_af, rt_mode, ipvsh, skb, mtu))
+ goto err_put;
+
+ skb_dst_drop(skb);
+ if (noref) {
+ if (!local)
+ skb_dst_set_noref(skb, &rt->dst);
+ else
+ skb_dst_set(skb, dst_clone(&rt->dst));
+ } else
+ skb_dst_set(skb, &rt->dst);
+
+ return local;
+
+err_put:
+ if (!noref)
+ ip_rt_put(rt);
+ return -1;
+
+err_unreach:
+ dst_link_failure(skb);
+ return -1;
+}
+
+#ifdef CONFIG_IP_VS_IPV6
+static struct dst_entry *
+__ip_vs_route_output_v6(struct net *net, struct in6_addr *daddr,
+ struct in6_addr *ret_saddr, int do_xfrm)
+{
+ struct dst_entry *dst;
+ struct flowi6 fl6 = {
+ .daddr = *daddr,
+ };
+
+ dst = ip6_route_output(net, NULL, &fl6);
+ if (dst->error)
+ goto out_err;
+ if (!ret_saddr)
+ return dst;
+ if (ipv6_addr_any(&fl6.saddr) &&
+ ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
+ &fl6.daddr, 0, &fl6.saddr) < 0)
+ goto out_err;
+ if (do_xfrm) {
+ dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
+ if (IS_ERR(dst)) {
+ dst = NULL;
+ goto out_err;
+ }
+ }
+ *ret_saddr = fl6.saddr;
+ return dst;
+
+out_err:
+ dst_release(dst);
+ IP_VS_DBG_RL("ip6_route_output error, dest: %pI6\n", daddr);
+ return NULL;
+}
+
+/*
+ * Get route to destination or remote server
+ */
+static int
+__ip_vs_get_out_rt_v6(int skb_af, struct sk_buff *skb, struct ip_vs_dest *dest,
+ struct in6_addr *daddr, struct in6_addr *ret_saddr,
+ struct ip_vs_iphdr *ipvsh, int do_xfrm, int rt_mode)
+{
+ struct net *net = dev_net(skb_dst(skb)->dev);
+ struct ip_vs_dest_dst *dest_dst;
+ struct rt6_info *rt; /* Route to the other host */
+ struct dst_entry *dst;
+ int mtu;
+ int local, noref = 1;
+
+ if (dest) {
+ dest_dst = __ip_vs_dst_check(dest);
+ if (likely(dest_dst))
+ rt = (struct rt6_info *) dest_dst->dst_cache;
+ else {
+ u32 cookie;
+
+ dest_dst = ip_vs_dest_dst_alloc();
+ spin_lock_bh(&dest->dst_lock);
+ if (!dest_dst) {
+ __ip_vs_dst_set(dest, NULL, NULL, 0);
+ spin_unlock_bh(&dest->dst_lock);
+ goto err_unreach;
+ }
+ dst = __ip_vs_route_output_v6(net, &dest->addr.in6,
+ &dest_dst->dst_saddr.in6,
+ do_xfrm);
+ if (!dst) {
+ __ip_vs_dst_set(dest, NULL, NULL, 0);
+ spin_unlock_bh(&dest->dst_lock);
+ ip_vs_dest_dst_free(dest_dst);
+ goto err_unreach;
+ }
+ rt = (struct rt6_info *) dst;
+ cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
+ __ip_vs_dst_set(dest, dest_dst, &rt->dst, cookie);
+ spin_unlock_bh(&dest->dst_lock);
+ IP_VS_DBG(10, "new dst %pI6, src %pI6, refcnt=%d\n",
+ &dest->addr.in6, &dest_dst->dst_saddr.in6,
+ atomic_read(&rt->dst.__refcnt));
+ }
+ if (ret_saddr)
+ *ret_saddr = dest_dst->dst_saddr.in6;
+ } else {
+ noref = 0;
+ dst = __ip_vs_route_output_v6(net, daddr, ret_saddr, do_xfrm);
+ if (!dst)
+ goto err_unreach;
+ rt = (struct rt6_info *) dst;
+ }
+
+ local = __ip_vs_is_local_route6(rt);
+
+ if (unlikely(crosses_local_route_boundary(skb_af, skb, rt_mode,
+ local))) {
+ IP_VS_DBG_RL("We are crossing local and non-local addresses"
+ " daddr=%pI6\n", daddr);
+ goto err_put;
+ }
+
+ if (unlikely(local)) {
+ /* skb to local stack, preserve old route */
+ if (!noref)
+ dst_release(&rt->dst);
+ return local;
+ }
+
+ /* MTU checking */
+ if (likely(!(rt_mode & IP_VS_RT_MODE_TUNNEL)))
+ mtu = dst_mtu(&rt->dst);
+ else {
+ mtu = dst_mtu(&rt->dst) - sizeof(struct ipv6hdr);
+ if (mtu < IPV6_MIN_MTU) {
+ IP_VS_DBG_RL("%s(): mtu less than %d\n", __func__,
+ IPV6_MIN_MTU);
+ goto err_put;
+ }
+ maybe_update_pmtu(skb_af, skb, mtu);
+ }
+
+ if (!ensure_mtu_is_adequate(skb_af, rt_mode, ipvsh, skb, mtu))
+ goto err_put;
+
+ skb_dst_drop(skb);
+ if (noref) {
+ if (!local)
+ skb_dst_set_noref(skb, &rt->dst);
+ else
+ skb_dst_set(skb, dst_clone(&rt->dst));
+ } else
+ skb_dst_set(skb, &rt->dst);
+
+ return local;
+
+err_put:
+ if (!noref)
+ dst_release(&rt->dst);
+ return -1;
+
+err_unreach:
+ dst_link_failure(skb);
+ return -1;
+}
+#endif
+
+
+/* return NF_ACCEPT to allow forwarding or other NF_xxx on error */
+static inline int ip_vs_tunnel_xmit_prepare(struct sk_buff *skb,
+ struct ip_vs_conn *cp)
+{
+ int ret = NF_ACCEPT;
+
+ skb->ipvs_property = 1;
+ if (unlikely(cp->flags & IP_VS_CONN_F_NFCT))
+ ret = ip_vs_confirm_conntrack(skb);
+ if (ret == NF_ACCEPT) {
+ nf_reset(skb);
+ skb_forward_csum(skb);
+ }
+ return ret;
+}
+
+/* return NF_STOLEN (sent) or NF_ACCEPT if local=1 (not sent) */
+static inline int ip_vs_nat_send_or_cont(int pf, struct sk_buff *skb,
+ struct ip_vs_conn *cp, int local)
+{
+ int ret = NF_STOLEN;
+
+ skb->ipvs_property = 1;
+ if (likely(!(cp->flags & IP_VS_CONN_F_NFCT)))
+ ip_vs_notrack(skb);
+ else
+ ip_vs_update_conntrack(skb, cp, 1);
+ if (!local) {
+ skb_forward_csum(skb);
+ NF_HOOK(pf, NF_INET_LOCAL_OUT, NULL, skb,
+ NULL, skb_dst(skb)->dev, dst_output_sk);
+ } else
+ ret = NF_ACCEPT;
+ return ret;
+}
+
+/* return NF_STOLEN (sent) or NF_ACCEPT if local=1 (not sent) */
+static inline int ip_vs_send_or_cont(int pf, struct sk_buff *skb,
+ struct ip_vs_conn *cp, int local)
+{
+ int ret = NF_STOLEN;
+
+ skb->ipvs_property = 1;
+ if (likely(!(cp->flags & IP_VS_CONN_F_NFCT)))
+ ip_vs_notrack(skb);
+ if (!local) {
+ skb_forward_csum(skb);
+ NF_HOOK(pf, NF_INET_LOCAL_OUT, NULL, skb,
+ NULL, skb_dst(skb)->dev, dst_output_sk);
+ } else
+ ret = NF_ACCEPT;
+ return ret;
+}
+
+
+/*
+ * NULL transmitter (do nothing except return NF_ACCEPT)
+ */
+int
+ip_vs_null_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ /* we do not touch skb and do not need pskb ptr */
+ return ip_vs_send_or_cont(NFPROTO_IPV4, skb, cp, 1);
+}
+
+
+/*
+ * Bypass transmitter
+ * Let packets bypass the destination when the destination is not
+ * available, it may be only used in transparent cache cluster.
+ */
+int
+ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ struct iphdr *iph = ip_hdr(skb);
+
+ EnterFunction(10);
+
+ rcu_read_lock();
+ if (__ip_vs_get_out_rt(cp->af, skb, NULL, iph->daddr,
+ IP_VS_RT_MODE_NON_LOCAL, NULL, ipvsh) < 0)
+ goto tx_error;
+
+ ip_send_check(iph);
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ ip_vs_send_or_cont(NFPROTO_IPV4, skb, cp, 0);
+ rcu_read_unlock();
+
+ LeaveFunction(10);
+ return NF_STOLEN;
+
+ tx_error:
+ kfree_skb(skb);
+ rcu_read_unlock();
+ LeaveFunction(10);
+ return NF_STOLEN;
+}
+
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ EnterFunction(10);
+
+ rcu_read_lock();
+ if (__ip_vs_get_out_rt_v6(cp->af, skb, NULL, &ipvsh->daddr.in6, NULL,
+ ipvsh, 0, IP_VS_RT_MODE_NON_LOCAL) < 0)
+ goto tx_error;
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ ip_vs_send_or_cont(NFPROTO_IPV6, skb, cp, 0);
+ rcu_read_unlock();
+
+ LeaveFunction(10);
+ return NF_STOLEN;
+
+ tx_error:
+ kfree_skb(skb);
+ rcu_read_unlock();
+ LeaveFunction(10);
+ return NF_STOLEN;
+}
+#endif
+
+/*
+ * NAT transmitter (only for outside-to-inside nat forwarding)
+ * Not used for related ICMP
+ */
+int
+ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ struct rtable *rt; /* Route to the other host */
+ int local, rc, was_input;
+
+ EnterFunction(10);
+
+ rcu_read_lock();
+ /* check if it is a connection of no-client-port */
+ if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT)) {
+ __be16 _pt, *p;
+
+ p = skb_header_pointer(skb, ipvsh->len, sizeof(_pt), &_pt);
+ if (p == NULL)
+ goto tx_error;
+ ip_vs_conn_fill_cport(cp, *p);
+ IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p));
+ }
+
+ was_input = rt_is_input_route(skb_rtable(skb));
+ local = __ip_vs_get_out_rt(cp->af, skb, cp->dest, cp->daddr.ip,
+ IP_VS_RT_MODE_LOCAL |
+ IP_VS_RT_MODE_NON_LOCAL |
+ IP_VS_RT_MODE_RDR, NULL, ipvsh);
+ if (local < 0)
+ goto tx_error;
+ rt = skb_rtable(skb);
+ /*
+ * Avoid duplicate tuple in reply direction for NAT traffic
+ * to local address when connection is sync-ed
+ */
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ if (cp->flags & IP_VS_CONN_F_SYNC && local) {
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+ if (ct && !nf_ct_is_untracked(ct)) {
+ IP_VS_DBG_RL_PKT(10, AF_INET, pp, skb, 0,
+ "ip_vs_nat_xmit(): "
+ "stopping DNAT to local address");
+ goto tx_error;
+ }
+ }
+#endif
+
+ /* From world but DNAT to loopback address? */
+ if (local && ipv4_is_loopback(cp->daddr.ip) && was_input) {
+ IP_VS_DBG_RL_PKT(1, AF_INET, pp, skb, 0, "ip_vs_nat_xmit(): "
+ "stopping DNAT to loopback address");
+ goto tx_error;
+ }
+
+ /* copy-on-write the packet before mangling it */
+ if (!skb_make_writable(skb, sizeof(struct iphdr)))
+ goto tx_error;
+
+ if (skb_cow(skb, rt->dst.dev->hard_header_len))
+ goto tx_error;
+
+ /* mangle the packet */
+ if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp, ipvsh))
+ goto tx_error;
+ ip_hdr(skb)->daddr = cp->daddr.ip;
+ ip_send_check(ip_hdr(skb));
+
+ IP_VS_DBG_PKT(10, AF_INET, pp, skb, 0, "After DNAT");
+
+ /* FIXME: when application helper enlarges the packet and the length
+ is larger than the MTU of outgoing device, there will be still
+ MTU problem. */
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ rc = ip_vs_nat_send_or_cont(NFPROTO_IPV4, skb, cp, local);
+ rcu_read_unlock();
+
+ LeaveFunction(10);
+ return rc;
+
+ tx_error:
+ kfree_skb(skb);
+ rcu_read_unlock();
+ LeaveFunction(10);
+ return NF_STOLEN;
+}
+
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ struct rt6_info *rt; /* Route to the other host */
+ int local, rc;
+
+ EnterFunction(10);
+
+ rcu_read_lock();
+ /* check if it is a connection of no-client-port */
+ if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT && !ipvsh->fragoffs)) {
+ __be16 _pt, *p;
+ p = skb_header_pointer(skb, ipvsh->len, sizeof(_pt), &_pt);
+ if (p == NULL)
+ goto tx_error;
+ ip_vs_conn_fill_cport(cp, *p);
+ IP_VS_DBG(10, "filled cport=%d\n", ntohs(*p));
+ }
+
+ local = __ip_vs_get_out_rt_v6(cp->af, skb, cp->dest, &cp->daddr.in6,
+ NULL, ipvsh, 0,
+ IP_VS_RT_MODE_LOCAL |
+ IP_VS_RT_MODE_NON_LOCAL |
+ IP_VS_RT_MODE_RDR);
+ if (local < 0)
+ goto tx_error;
+ rt = (struct rt6_info *) skb_dst(skb);
+ /*
+ * Avoid duplicate tuple in reply direction for NAT traffic
+ * to local address when connection is sync-ed
+ */
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ if (cp->flags & IP_VS_CONN_F_SYNC && local) {
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+ if (ct && !nf_ct_is_untracked(ct)) {
+ IP_VS_DBG_RL_PKT(10, AF_INET6, pp, skb, 0,
+ "ip_vs_nat_xmit_v6(): "
+ "stopping DNAT to local address");
+ goto tx_error;
+ }
+ }
+#endif
+
+ /* From world but DNAT to loopback address? */
+ if (local && skb->dev && !(skb->dev->flags & IFF_LOOPBACK) &&
+ ipv6_addr_type(&rt->rt6i_dst.addr) & IPV6_ADDR_LOOPBACK) {
+ IP_VS_DBG_RL_PKT(1, AF_INET6, pp, skb, 0,
+ "ip_vs_nat_xmit_v6(): "
+ "stopping DNAT to loopback address");
+ goto tx_error;
+ }
+
+ /* copy-on-write the packet before mangling it */
+ if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
+ goto tx_error;
+
+ if (skb_cow(skb, rt->dst.dev->hard_header_len))
+ goto tx_error;
+
+ /* mangle the packet */
+ if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp, ipvsh))
+ goto tx_error;
+ ipv6_hdr(skb)->daddr = cp->daddr.in6;
+
+ IP_VS_DBG_PKT(10, AF_INET6, pp, skb, 0, "After DNAT");
+
+ /* FIXME: when application helper enlarges the packet and the length
+ is larger than the MTU of outgoing device, there will be still
+ MTU problem. */
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ rc = ip_vs_nat_send_or_cont(NFPROTO_IPV6, skb, cp, local);
+ rcu_read_unlock();
+
+ LeaveFunction(10);
+ return rc;
+
+tx_error:
+ LeaveFunction(10);
+ kfree_skb(skb);
+ rcu_read_unlock();
+ return NF_STOLEN;
+}
+#endif
+
+/* When forwarding a packet, we must ensure that we've got enough headroom
+ * for the encapsulation packet in the skb. This also gives us an
+ * opportunity to figure out what the payload_len, dsfield, ttl, and df
+ * values should be, so that we won't need to look at the old ip header
+ * again
+ */
+static struct sk_buff *
+ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af,
+ unsigned int max_headroom, __u8 *next_protocol,
+ __u32 *payload_len, __u8 *dsfield, __u8 *ttl,
+ __be16 *df)
+{
+ struct sk_buff *new_skb = NULL;
+ struct iphdr *old_iph = NULL;
+#ifdef CONFIG_IP_VS_IPV6
+ struct ipv6hdr *old_ipv6h = NULL;
+#endif
+
+ if (skb_headroom(skb) < max_headroom || skb_cloned(skb)) {
+ new_skb = skb_realloc_headroom(skb, max_headroom);
+ if (!new_skb)
+ goto error;
+ if (skb->sk)
+ skb_set_owner_w(new_skb, skb->sk);
+ consume_skb(skb);
+ skb = new_skb;
+ }
+
+#ifdef CONFIG_IP_VS_IPV6
+ if (skb_af == AF_INET6) {
+ old_ipv6h = ipv6_hdr(skb);
+ *next_protocol = IPPROTO_IPV6;
+ if (payload_len)
+ *payload_len =
+ ntohs(old_ipv6h->payload_len) +
+ sizeof(*old_ipv6h);
+ *dsfield = ipv6_get_dsfield(old_ipv6h);
+ *ttl = old_ipv6h->hop_limit;
+ if (df)
+ *df = 0;
+ } else
+#endif
+ {
+ old_iph = ip_hdr(skb);
+ /* Copy DF, reset fragment offset and MF */
+ if (df)
+ *df = (old_iph->frag_off & htons(IP_DF));
+ *next_protocol = IPPROTO_IPIP;
+
+ /* fix old IP header checksum */
+ ip_send_check(old_iph);
+ *dsfield = ipv4_get_dsfield(old_iph);
+ *ttl = old_iph->ttl;
+ if (payload_len)
+ *payload_len = ntohs(old_iph->tot_len);
+ }
+
+ return skb;
+error:
+ kfree_skb(skb);
+ return ERR_PTR(-ENOMEM);
+}
+
+static inline int __tun_gso_type_mask(int encaps_af, int orig_af)
+{
+ if (encaps_af == AF_INET) {
+ if (orig_af == AF_INET)
+ return SKB_GSO_IPIP;
+
+ return SKB_GSO_SIT;
+ }
+
+ /* GSO: we need to provide proper SKB_GSO_ value for IPv6:
+ * SKB_GSO_SIT/IPV6
+ */
+ return 0;
+}
+
+/*
+ * IP Tunneling transmitter
+ *
+ * This function encapsulates the packet in a new IP packet, its
+ * destination will be set to cp->daddr. Most code of this function
+ * is taken from ipip.c.
+ *
+ * It is used in VS/TUN cluster. The load balancer selects a real
+ * server from a cluster based on a scheduling algorithm,
+ * encapsulates the request packet and forwards it to the selected
+ * server. For example, all real servers are configured with
+ * "ifconfig tunl0 <Virtual IP Address> up". When the server receives
+ * the encapsulated packet, it will decapsulate the packet, processe
+ * the request and return the response packets directly to the client
+ * without passing the load balancer. This can greatly increase the
+ * scalability of virtual server.
+ *
+ * Used for ANY protocol
+ */
+int
+ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ struct net *net = skb_net(skb);
+ struct netns_ipvs *ipvs = net_ipvs(net);
+ struct rtable *rt; /* Route to the other host */
+ __be32 saddr; /* Source for tunnel */
+ struct net_device *tdev; /* Device to other host */
+ __u8 next_protocol = 0;
+ __u8 dsfield = 0;
+ __u8 ttl = 0;
+ __be16 df = 0;
+ __be16 *dfp = NULL;
+ struct iphdr *iph; /* Our new IP header */
+ unsigned int max_headroom; /* The extra header space needed */
+ int ret, local;
+
+ EnterFunction(10);
+
+ rcu_read_lock();
+ local = __ip_vs_get_out_rt(cp->af, skb, cp->dest, cp->daddr.ip,
+ IP_VS_RT_MODE_LOCAL |
+ IP_VS_RT_MODE_NON_LOCAL |
+ IP_VS_RT_MODE_CONNECT |
+ IP_VS_RT_MODE_TUNNEL, &saddr, ipvsh);
+ if (local < 0)
+ goto tx_error;
+ if (local) {
+ rcu_read_unlock();
+ return ip_vs_send_or_cont(NFPROTO_IPV4, skb, cp, 1);
+ }
+
+ rt = skb_rtable(skb);
+ tdev = rt->dst.dev;
+
+ /*
+ * Okay, now see if we can stuff it in the buffer as-is.
+ */
+ max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr);
+
+ /* We only care about the df field if sysctl_pmtu_disc(ipvs) is set */
+ dfp = sysctl_pmtu_disc(ipvs) ? &df : NULL;
+ skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom,
+ &next_protocol, NULL, &dsfield,
+ &ttl, dfp);
+ if (IS_ERR(skb))
+ goto tx_error;
+
+ skb = iptunnel_handle_offloads(
+ skb, false, __tun_gso_type_mask(AF_INET, cp->af));
+ if (IS_ERR(skb))
+ goto tx_error;
+
+ skb->transport_header = skb->network_header;
+
+ skb_push(skb, sizeof(struct iphdr));
+ skb_reset_network_header(skb);
+ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+
+ /*
+ * Push down and install the IPIP header.
+ */
+ iph = ip_hdr(skb);
+ iph->version = 4;
+ iph->ihl = sizeof(struct iphdr)>>2;
+ iph->frag_off = df;
+ iph->protocol = next_protocol;
+ iph->tos = dsfield;
+ iph->daddr = cp->daddr.ip;
+ iph->saddr = saddr;
+ iph->ttl = ttl;
+ ip_select_ident(net, skb, NULL);
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ ret = ip_vs_tunnel_xmit_prepare(skb, cp);
+ if (ret == NF_ACCEPT)
+ ip_local_out(skb);
+ else if (ret == NF_DROP)
+ kfree_skb(skb);
+ rcu_read_unlock();
+
+ LeaveFunction(10);
+
+ return NF_STOLEN;
+
+ tx_error:
+ if (!IS_ERR(skb))
+ kfree_skb(skb);
+ rcu_read_unlock();
+ LeaveFunction(10);
+ return NF_STOLEN;
+}
+
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ struct rt6_info *rt; /* Route to the other host */
+ struct in6_addr saddr; /* Source for tunnel */
+ struct net_device *tdev; /* Device to other host */
+ __u8 next_protocol = 0;
+ __u32 payload_len = 0;
+ __u8 dsfield = 0;
+ __u8 ttl = 0;
+ struct ipv6hdr *iph; /* Our new IP header */
+ unsigned int max_headroom; /* The extra header space needed */
+ int ret, local;
+
+ EnterFunction(10);
+
+ rcu_read_lock();
+ local = __ip_vs_get_out_rt_v6(cp->af, skb, cp->dest, &cp->daddr.in6,
+ &saddr, ipvsh, 1,
+ IP_VS_RT_MODE_LOCAL |
+ IP_VS_RT_MODE_NON_LOCAL |
+ IP_VS_RT_MODE_TUNNEL);
+ if (local < 0)
+ goto tx_error;
+ if (local) {
+ rcu_read_unlock();
+ return ip_vs_send_or_cont(NFPROTO_IPV6, skb, cp, 1);
+ }
+
+ rt = (struct rt6_info *) skb_dst(skb);
+ tdev = rt->dst.dev;
+
+ /*
+ * Okay, now see if we can stuff it in the buffer as-is.
+ */
+ max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct ipv6hdr);
+
+ skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom,
+ &next_protocol, &payload_len,
+ &dsfield, &ttl, NULL);
+ if (IS_ERR(skb))
+ goto tx_error;
+
+ skb = iptunnel_handle_offloads(
+ skb, false, __tun_gso_type_mask(AF_INET6, cp->af));
+ if (IS_ERR(skb))
+ goto tx_error;
+
+ skb->transport_header = skb->network_header;
+
+ skb_push(skb, sizeof(struct ipv6hdr));
+ skb_reset_network_header(skb);
+ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+
+ /*
+ * Push down and install the IPIP header.
+ */
+ iph = ipv6_hdr(skb);
+ iph->version = 6;
+ iph->nexthdr = next_protocol;
+ iph->payload_len = htons(payload_len);
+ memset(&iph->flow_lbl, 0, sizeof(iph->flow_lbl));
+ ipv6_change_dsfield(iph, 0, dsfield);
+ iph->daddr = cp->daddr.in6;
+ iph->saddr = saddr;
+ iph->hop_limit = ttl;
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ ret = ip_vs_tunnel_xmit_prepare(skb, cp);
+ if (ret == NF_ACCEPT)
+ ip6_local_out(skb);
+ else if (ret == NF_DROP)
+ kfree_skb(skb);
+ rcu_read_unlock();
+
+ LeaveFunction(10);
+
+ return NF_STOLEN;
+
+tx_error:
+ if (!IS_ERR(skb))
+ kfree_skb(skb);
+ rcu_read_unlock();
+ LeaveFunction(10);
+ return NF_STOLEN;
+}
+#endif
+
+
+/*
+ * Direct Routing transmitter
+ * Used for ANY protocol
+ */
+int
+ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ int local;
+
+ EnterFunction(10);
+
+ rcu_read_lock();
+ local = __ip_vs_get_out_rt(cp->af, skb, cp->dest, cp->daddr.ip,
+ IP_VS_RT_MODE_LOCAL |
+ IP_VS_RT_MODE_NON_LOCAL |
+ IP_VS_RT_MODE_KNOWN_NH, NULL, ipvsh);
+ if (local < 0)
+ goto tx_error;
+ if (local) {
+ rcu_read_unlock();
+ return ip_vs_send_or_cont(NFPROTO_IPV4, skb, cp, 1);
+ }
+
+ ip_send_check(ip_hdr(skb));
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ ip_vs_send_or_cont(NFPROTO_IPV4, skb, cp, 0);
+ rcu_read_unlock();
+
+ LeaveFunction(10);
+ return NF_STOLEN;
+
+ tx_error:
+ kfree_skb(skb);
+ rcu_read_unlock();
+ LeaveFunction(10);
+ return NF_STOLEN;
+}
+
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_dr_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
+{
+ int local;
+
+ EnterFunction(10);
+
+ rcu_read_lock();
+ local = __ip_vs_get_out_rt_v6(cp->af, skb, cp->dest, &cp->daddr.in6,
+ NULL, ipvsh, 0,
+ IP_VS_RT_MODE_LOCAL |
+ IP_VS_RT_MODE_NON_LOCAL);
+ if (local < 0)
+ goto tx_error;
+ if (local) {
+ rcu_read_unlock();
+ return ip_vs_send_or_cont(NFPROTO_IPV6, skb, cp, 1);
+ }
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ ip_vs_send_or_cont(NFPROTO_IPV6, skb, cp, 0);
+ rcu_read_unlock();
+
+ LeaveFunction(10);
+ return NF_STOLEN;
+
+tx_error:
+ kfree_skb(skb);
+ rcu_read_unlock();
+ LeaveFunction(10);
+ return NF_STOLEN;
+}
+#endif
+
+
+/*
+ * ICMP packet transmitter
+ * called by the ip_vs_in_icmp
+ */
+int
+ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, int offset, unsigned int hooknum,
+ struct ip_vs_iphdr *iph)
+{
+ struct rtable *rt; /* Route to the other host */
+ int rc;
+ int local;
+ int rt_mode, was_input;
+
+ EnterFunction(10);
+
+ /* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
+ forwarded directly here, because there is no need to
+ translate address/port back */
+ if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
+ if (cp->packet_xmit)
+ rc = cp->packet_xmit(skb, cp, pp, iph);
+ else
+ rc = NF_ACCEPT;
+ /* do not touch skb anymore */
+ atomic_inc(&cp->in_pkts);
+ goto out;
+ }
+
+ /*
+ * mangle and send the packet here (only for VS/NAT)
+ */
+ was_input = rt_is_input_route(skb_rtable(skb));
+
+ /* LOCALNODE from FORWARD hook is not supported */
+ rt_mode = (hooknum != NF_INET_FORWARD) ?
+ IP_VS_RT_MODE_LOCAL | IP_VS_RT_MODE_NON_LOCAL |
+ IP_VS_RT_MODE_RDR : IP_VS_RT_MODE_NON_LOCAL;
+ rcu_read_lock();
+ local = __ip_vs_get_out_rt(cp->af, skb, cp->dest, cp->daddr.ip, rt_mode,
+ NULL, iph);
+ if (local < 0)
+ goto tx_error;
+ rt = skb_rtable(skb);
+
+ /*
+ * Avoid duplicate tuple in reply direction for NAT traffic
+ * to local address when connection is sync-ed
+ */
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ if (cp->flags & IP_VS_CONN_F_SYNC && local) {
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+ if (ct && !nf_ct_is_untracked(ct)) {
+ IP_VS_DBG(10, "%s(): "
+ "stopping DNAT to local address %pI4\n",
+ __func__, &cp->daddr.ip);
+ goto tx_error;
+ }
+ }
+#endif
+
+ /* From world but DNAT to loopback address? */
+ if (local && ipv4_is_loopback(cp->daddr.ip) && was_input) {
+ IP_VS_DBG(1, "%s(): "
+ "stopping DNAT to loopback %pI4\n",
+ __func__, &cp->daddr.ip);
+ goto tx_error;
+ }
+
+ /* copy-on-write the packet before mangling it */
+ if (!skb_make_writable(skb, offset))
+ goto tx_error;
+
+ if (skb_cow(skb, rt->dst.dev->hard_header_len))
+ goto tx_error;
+
+ ip_vs_nat_icmp(skb, pp, cp, 0);
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ rc = ip_vs_nat_send_or_cont(NFPROTO_IPV4, skb, cp, local);
+ rcu_read_unlock();
+ goto out;
+
+ tx_error:
+ kfree_skb(skb);
+ rcu_read_unlock();
+ rc = NF_STOLEN;
+ out:
+ LeaveFunction(10);
+ return rc;
+}
+
+#ifdef CONFIG_IP_VS_IPV6
+int
+ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
+ struct ip_vs_protocol *pp, int offset, unsigned int hooknum,
+ struct ip_vs_iphdr *ipvsh)
+{
+ struct rt6_info *rt; /* Route to the other host */
+ int rc;
+ int local;
+ int rt_mode;
+
+ EnterFunction(10);
+
+ /* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
+ forwarded directly here, because there is no need to
+ translate address/port back */
+ if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
+ if (cp->packet_xmit)
+ rc = cp->packet_xmit(skb, cp, pp, ipvsh);
+ else
+ rc = NF_ACCEPT;
+ /* do not touch skb anymore */
+ atomic_inc(&cp->in_pkts);
+ goto out;
+ }
+
+ /*
+ * mangle and send the packet here (only for VS/NAT)
+ */
+
+ /* LOCALNODE from FORWARD hook is not supported */
+ rt_mode = (hooknum != NF_INET_FORWARD) ?
+ IP_VS_RT_MODE_LOCAL | IP_VS_RT_MODE_NON_LOCAL |
+ IP_VS_RT_MODE_RDR : IP_VS_RT_MODE_NON_LOCAL;
+ rcu_read_lock();
+ local = __ip_vs_get_out_rt_v6(cp->af, skb, cp->dest, &cp->daddr.in6,
+ NULL, ipvsh, 0, rt_mode);
+ if (local < 0)
+ goto tx_error;
+ rt = (struct rt6_info *) skb_dst(skb);
+ /*
+ * Avoid duplicate tuple in reply direction for NAT traffic
+ * to local address when connection is sync-ed
+ */
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ if (cp->flags & IP_VS_CONN_F_SYNC && local) {
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+ if (ct && !nf_ct_is_untracked(ct)) {
+ IP_VS_DBG(10, "%s(): "
+ "stopping DNAT to local address %pI6\n",
+ __func__, &cp->daddr.in6);
+ goto tx_error;
+ }
+ }
+#endif
+
+ /* From world but DNAT to loopback address? */
+ if (local && skb->dev && !(skb->dev->flags & IFF_LOOPBACK) &&
+ ipv6_addr_type(&rt->rt6i_dst.addr) & IPV6_ADDR_LOOPBACK) {
+ IP_VS_DBG(1, "%s(): "
+ "stopping DNAT to loopback %pI6\n",
+ __func__, &cp->daddr.in6);
+ goto tx_error;
+ }
+
+ /* copy-on-write the packet before mangling it */
+ if (!skb_make_writable(skb, offset))
+ goto tx_error;
+
+ if (skb_cow(skb, rt->dst.dev->hard_header_len))
+ goto tx_error;
+
+ ip_vs_nat_icmp_v6(skb, pp, cp, 0);
+
+ /* Another hack: avoid icmp_send in ip_fragment */
+ skb->ignore_df = 1;
+
+ rc = ip_vs_nat_send_or_cont(NFPROTO_IPV6, skb, cp, local);
+ rcu_read_unlock();
+ goto out;
+
+tx_error:
+ kfree_skb(skb);
+ rcu_read_unlock();
+ rc = NF_STOLEN;
+out:
+ LeaveFunction(10);
+ return rc;
+}
+#endif
Code Review / kvmfornfv.git / blobdiff