ipvs: Remove all remaining references to rt->rt_{src,dst}

Remove all remaining references to rt->rt_{src,dst}
by using dest->dst_saddr to cache saddr (used for TUN mode).
For ICMP in FORWARD hook just restrict the rt_mode for NAT
to disable LOCALNODE. All other modes do not allow
IP_VS_RT_MODE_RDR, so we should be safe with the ICMP
forwarding. Using cp->daddr as replacement for rt_dst
is safe for all modes except BYPASS, even when cp->dest is
NULL because it is cp->daddr that is used to assign cp->dest
for sync-ed connections.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 54 insertions, 51 deletions

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 9d1f510ab6d0..4fff432aeade 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -665,9 +665,7 @@ struct ip_vs_dest {
         struct dst_entry        *dst_cache;     /* destination cache entry */
         u32                     dst_rtos;       /* RT_TOS(tos) for dst */
         u32                     dst_cookie;
-#ifdef CONFIG_IP_VS_IPV6
-        struct in6_addr         dst_saddr;
-#endif
+        union nf_inet_addr      dst_saddr;
 
         /* for virtual service */
         struct ip_vs_service    *svc;           /* service it belongs to */
@@ -1253,7 +1251,8 @@ extern int ip_vs_tunnel_xmit
 extern int ip_vs_dr_xmit
 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
 extern int ip_vs_icmp_xmit
-(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp, int offset);
+(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp,
+ int offset, unsigned int hooknum);
 extern void ip_vs_dst_reset(struct ip_vs_dest *dest);
 
 #ifdef CONFIG_IP_VS_IPV6
@@ -1267,7 +1266,7 @@ extern int ip_vs_dr_xmit_v6
 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
 extern int ip_vs_icmp_xmit_v6
 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp,
- int offset);
+ int offset, unsigned int hooknum);
 #endif
 
 #ifdef CONFIG_SYSCTL
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index a74dae6c5dbc..bfa808f4da13 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -1382,15 +1382,7 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum)
         ip_vs_in_stats(cp, skb);
         if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
                 offset += 2 * sizeof(__u16);
-        verdict = ip_vs_icmp_xmit(skb, cp, pp, offset);
-        /* LOCALNODE from FORWARD hook is not supported */
-        if (verdict == NF_ACCEPT && hooknum == NF_INET_FORWARD &&
-            skb_rtable(skb)->rt_flags & RTCF_LOCAL) {
-                IP_VS_DBG(1, "%s(): "
-                          "local delivery to %pI4 but in FORWARD\n",
-                          __func__, &skb_rtable(skb)->rt_dst);
-                verdict = NF_DROP;
-        }
+        verdict = ip_vs_icmp_xmit(skb, cp, pp, offset, hooknum);
 
   out:
         __ip_vs_conn_put(cp);
@@ -1412,7 +1404,6 @@ ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
         struct ip_vs_protocol *pp;
         struct ip_vs_proto_data *pd;
         unsigned int offset, verdict;
-        struct rt6_info *rt;
 
         *related = 1;
 
@@ -1474,23 +1465,12 @@ ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
         if (!cp)
                 return NF_ACCEPT;
 
-        verdict = NF_DROP;
-
         /* do the statistics and put it back */
         ip_vs_in_stats(cp, skb);
         if (IPPROTO_TCP == cih->nexthdr || IPPROTO_UDP == cih->nexthdr ||
             IPPROTO_SCTP == cih->nexthdr)
                 offset += 2 * sizeof(__u16);
-        verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset);
-        /* LOCALNODE from FORWARD hook is not supported */
-        if (verdict == NF_ACCEPT && hooknum == NF_INET_FORWARD &&
-            (rt = (struct rt6_info *) skb_dst(skb)) &&
-            rt->rt6i_dev && rt->rt6i_dev->flags & IFF_LOOPBACK) {
-                IP_VS_DBG(1, "%s(): "
-                          "local delivery to %pI6 but in FORWARD\n",
-                          __func__, &rt->rt6i_dst);
-                verdict = NF_DROP;
-        }
+        verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset, hooknum);
 
         __ip_vs_conn_put(cp);
 
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 3f3e0f4c38a5..ee319a4338b0 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -87,7 +87,7 @@ __ip_vs_dst_check(struct ip_vs_dest *dest, u32 rtos)
 /* Get route to destination or remote server */
 static struct rtable *
 __ip_vs_get_out_rt(struct sk_buff *skb, struct ip_vs_dest *dest,
-                   __be32 daddr, u32 rtos, int rt_mode)
+                   __be32 daddr, u32 rtos, int rt_mode, __be32 *ret_saddr)
 {
         struct net *net = dev_net(skb_dst(skb)->dev);
         struct rtable *rt;                      /* Route to the other host */
@@ -98,7 +98,12 @@ __ip_vs_get_out_rt(struct sk_buff *skb, struct ip_vs_dest *dest,
                 spin_lock(&dest->dst_lock);
                 if (!(rt = (struct rtable *)
                       __ip_vs_dst_check(dest, rtos))) {
-                        rt = ip_route_output(net, dest->addr.ip, 0, rtos, 0);
+                        struct flowi4 fl4;
+
+                        memset(&fl4, 0, sizeof(fl4));
+                        fl4.daddr = dest->addr.ip;
+                        fl4.flowi4_tos = rtos;
+                        rt = ip_route_output_key(net, &fl4);
                         if (IS_ERR(rt)) {
                                 spin_unlock(&dest->dst_lock);
                                 IP_VS_DBG_RL("ip_route_output error, dest: %pI4\n",
@@ -106,19 +111,30 @@ __ip_vs_get_out_rt(struct sk_buff *skb, struct ip_vs_dest *dest,
                                 return NULL;
                         }
                         __ip_vs_dst_set(dest, rtos, dst_clone(&rt->dst), 0);
-                        IP_VS_DBG(10, "new dst %pI4, refcnt=%d, rtos=%X\n",
-                                  &dest->addr.ip,
+                        dest->dst_saddr.ip = fl4.saddr;
+                        IP_VS_DBG(10, "new dst %pI4, src %pI4, refcnt=%d, "
+                                  "rtos=%X\n",
+                                  &dest->addr.ip, &dest->dst_saddr.ip,
                                   atomic_read(&rt->dst.__refcnt), rtos);
                 }
                 daddr = dest->addr.ip;
+                if (ret_saddr)
+                        *ret_saddr = dest->dst_saddr.ip;
                 spin_unlock(&dest->dst_lock);
         } else {
-                rt = ip_route_output(net, daddr, 0, rtos, 0);
+                struct flowi4 fl4;
+
+                memset(&fl4, 0, sizeof(fl4));
+                fl4.daddr = daddr;
+                fl4.flowi4_tos = rtos;
+                rt = ip_route_output_key(net, &fl4);
                 if (IS_ERR(rt)) {
                         IP_VS_DBG_RL("ip_route_output error, dest: %pI4\n",
                                      &daddr);
                         return NULL;
                 }
+                if (ret_saddr)
+                        *ret_saddr = fl4.saddr;
         }
 
         local = rt->rt_flags & RTCF_LOCAL;
@@ -249,7 +265,7 @@ __ip_vs_get_out_rt_v6(struct sk_buff *skb, struct ip_vs_dest *dest,
                         u32 cookie;
 
                         dst = __ip_vs_route_output_v6(net, &dest->addr.in6,
-                                                      &dest->dst_saddr,
+                                                      &dest->dst_saddr.in6,
                                                       do_xfrm);
                         if (!dst) {
                                 spin_unlock(&dest->dst_lock);
@@ -259,11 +275,11 @@ __ip_vs_get_out_rt_v6(struct sk_buff *skb, struct ip_vs_dest *dest,
                         cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
                         __ip_vs_dst_set(dest, 0, dst_clone(&rt->dst), cookie);
                         IP_VS_DBG(10, "new dst %pI6, src %pI6, refcnt=%d\n",
-                                  &dest->addr.in6, &dest->dst_saddr,
+                                  &dest->addr.in6, &dest->dst_saddr.in6,
                                   atomic_read(&rt->dst.__refcnt));
                 }
                 if (ret_saddr)
-                        ipv6_addr_copy(ret_saddr, &dest->dst_saddr);
+                        ipv6_addr_copy(ret_saddr, &dest->dst_saddr.in6);
                 spin_unlock(&dest->dst_lock);
         } else {
                 dst = __ip_vs_route_output_v6(net, daddr, ret_saddr, do_xfrm);
@@ -386,7 +402,7 @@ ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         EnterFunction(10);
 
         if (!(rt = __ip_vs_get_out_rt(skb, NULL, iph->daddr, RT_TOS(iph->tos),
-                                      IP_VS_RT_MODE_NON_LOCAL)))
+                                      IP_VS_RT_MODE_NON_LOCAL, NULL)))
                 goto tx_error_icmp;
 
         /* MTU checking */
@@ -518,7 +534,7 @@ ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
                                       RT_TOS(iph->tos),
                                       IP_VS_RT_MODE_LOCAL |
                                         IP_VS_RT_MODE_NON_LOCAL |
-                                        IP_VS_RT_MODE_RDR)))
+                                        IP_VS_RT_MODE_RDR, NULL)))
                 goto tx_error_icmp;
         local = rt->rt_flags & RTCF_LOCAL;
         /*
@@ -540,7 +556,7 @@ ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 #endif
 
         /* From world but DNAT to loopback address? */
-        if (local && ipv4_is_loopback(rt->rt_dst) &&
+        if (local && ipv4_is_loopback(cp->daddr.ip) &&
             rt_is_input_route(skb_rtable(skb))) {
                 IP_VS_DBG_RL_PKT(1, AF_INET, pp, skb, 0, "ip_vs_nat_xmit(): "
                                  "stopping DNAT to loopback address");
@@ -751,6 +767,7 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
                   struct ip_vs_protocol *pp)
 {
         struct rtable *rt;                      /* Route to the other host */
+        __be32 saddr;                           /* Source for tunnel */
         struct net_device *tdev;                /* Device to other host */
         struct iphdr  *old_iph = ip_hdr(skb);
         u8     tos = old_iph->tos;
@@ -764,7 +781,8 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 
         if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
                                       RT_TOS(tos), IP_VS_RT_MODE_LOCAL |
-                                                   IP_VS_RT_MODE_NON_LOCAL)))
+                                                   IP_VS_RT_MODE_NON_LOCAL,
+                                                   &saddr)))
                 goto tx_error_icmp;
         if (rt->rt_flags & RTCF_LOCAL) {
                 ip_rt_put(rt);
@@ -832,8 +850,8 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         iph->frag_off           =       df;
         iph->protocol           =       IPPROTO_IPIP;
         iph->tos                =       tos;
-        iph->daddr              =       rt->rt_dst;
-        iph->saddr              =       rt->rt_src;
+        iph->daddr              =       cp->daddr.ip;
+        iph->saddr              =       saddr;
         iph->ttl                =       old_iph->ttl;
         ip_select_ident(iph, &rt->dst, NULL);
 
@@ -996,7 +1014,7 @@ ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
         if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
                                       RT_TOS(iph->tos),
                                       IP_VS_RT_MODE_LOCAL |
-                                        IP_VS_RT_MODE_NON_LOCAL)))
+                                        IP_VS_RT_MODE_NON_LOCAL, NULL)))
                 goto tx_error_icmp;
         if (rt->rt_flags & RTCF_LOCAL) {
                 ip_rt_put(rt);
@@ -1114,12 +1132,13 @@ tx_error:
  */
 int
 ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
-                struct ip_vs_protocol *pp, int offset)
+                struct ip_vs_protocol *pp, int offset, unsigned int hooknum)
 {
         struct rtable   *rt;    /* Route to the other host */
         int mtu;
         int rc;
         int local;
+        int rt_mode;
 
         EnterFunction(10);
 
@@ -1140,11 +1159,13 @@ ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
          * 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;
         if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
                                       RT_TOS(ip_hdr(skb)->tos),
-                                      IP_VS_RT_MODE_LOCAL |
-                                        IP_VS_RT_MODE_NON_LOCAL |
-                                        IP_VS_RT_MODE_RDR)))
+                                      rt_mode, NULL)))
                 goto tx_error_icmp;
         local = rt->rt_flags & RTCF_LOCAL;
 
@@ -1167,7 +1188,7 @@ ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 #endif
 
         /* From world but DNAT to loopback address? */
-        if (local && ipv4_is_loopback(rt->rt_dst) &&
+        if (local && ipv4_is_loopback(cp->daddr.ip) &&
             rt_is_input_route(skb_rtable(skb))) {
                 IP_VS_DBG(1, "%s(): "
                           "stopping DNAT to loopback %pI4\n",
@@ -1232,12 +1253,13 @@ ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 #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)
+                struct ip_vs_protocol *pp, int offset, unsigned int hooknum)
 {
         struct rt6_info *rt;    /* Route to the other host */
         int mtu;
         int rc;
         int local;
+        int rt_mode;
 
         EnterFunction(10);
 
@@ -1258,10 +1280,12 @@ ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
          * 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;
         if (!(rt = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6, NULL,
-                                         0, (IP_VS_RT_MODE_LOCAL |
-                                             IP_VS_RT_MODE_NON_LOCAL |
-                                             IP_VS_RT_MODE_RDR))))
+                                         0, rt_mode)))
                 goto tx_error_icmp;
 
         local = __ip_vs_is_local_route6(rt);