ipv4: Add redirect support to all protocol icmp error handlers.

Signed-off-by: David S. Miller <davem@davemloft.net>

12 files changed, 110 insertions, 16 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 3eb76b5f221a..8f41a3190858 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -195,6 +195,14 @@ static inline void dccp_do_pmtu_discovery(struct sock *sk,
         } /* else let the usual retransmit timer handle it */
 }
 
+static void dccp_do_redirect(struct sk_buff *skb, struct sock *sk)
+{
+        struct dst_entry *dst = __sk_dst_check(sk, 0);
+
+        if (dst && dst->ops->redirect)
+                dst->ops->redirect(dst, skb);
+}
+
 /*
  * This routine is called by the ICMP module when it gets some sort of error
  * condition. If err < 0 then the socket should be closed and the error
@@ -259,6 +267,9 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
         }
 
         switch (type) {
+        case ICMP_REDIRECT:
+                dccp_do_redirect(skb, sk);
+                goto out;
         case ICMP_SOURCE_QUENCH:
                 /* Just silently ignore these. */
                 goto out;
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 916d5ecaf6c6..a0d8392491c3 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -398,17 +398,25 @@ static void ah4_err(struct sk_buff *skb, u32 info)
         struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
         struct xfrm_state *x;
 
-        if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
-            icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+        switch (icmp_hdr(skb)->type) {
+        case ICMP_DEST_UNREACH:
+                if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+                        return;
+        case ICMP_REDIRECT:
+                break;
+        default:
                 return;
+        }
 
         x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
                               ah->spi, IPPROTO_AH, AF_INET);
         if (!x)
                 return;
-        pr_debug("pmtu discovery on SA AH/%08x/%08x\n",
-                 ntohl(ah->spi), ntohl(iph->daddr));
-        ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0);
+
+        if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
+                ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0);
+        else
+                ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 0);
         xfrm_state_put(x);
 }
 
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 7b95b49a36ce..b61e9deb7c7e 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -484,17 +484,25 @@ static void esp4_err(struct sk_buff *skb, u32 info)
         struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
         struct xfrm_state *x;
 
-        if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
-            icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+        switch (icmp_hdr(skb)->type) {
+        case ICMP_DEST_UNREACH:
+                if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+                        return;
+        case ICMP_REDIRECT:
+                break;
+        default:
                 return;
+        }
 
         x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
                               esph->spi, IPPROTO_ESP, AF_INET);
         if (!x)
                 return;
-        NETDEBUG(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%08x\n",
-                 ntohl(esph->spi), ntohl(iph->daddr));
-        ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
+
+        if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
+                ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
+        else
+                ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
         xfrm_state_put(x);
 }
 
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 594cec35ac4d..0c3123566d76 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -528,6 +528,9 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
                 if (code != ICMP_EXC_TTL)
                         return;
                 break;
+
+        case ICMP_REDIRECT:
+                break;
         }
 
         rcu_read_lock();
@@ -543,7 +546,11 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
                                  t->parms.link, 0, IPPROTO_GRE, 0);
                 goto out;
         }
-
+        if (type == ICMP_REDIRECT) {
+                ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
+                              IPPROTO_GRE, 0);
+                goto out;
+        }
         if (t->parms.iph.daddr == 0 ||
             ipv4_is_multicast(t->parms.iph.daddr))
                 goto out;
diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index b91375482d84..d3ab47e19a89 100644
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -31,18 +31,26 @@ static void ipcomp4_err(struct sk_buff *skb, u32 info)
         struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
         struct xfrm_state *x;
 
-        if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
-            icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+        switch (icmp_hdr(skb)->type) {
+        case ICMP_DEST_UNREACH:
+                if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+                        return;
+        case ICMP_REDIRECT:
+                break;
+        default:
                 return;
+        }
 
         spi = htonl(ntohs(ipch->cpi));
         x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
                               spi, IPPROTO_COMP, AF_INET);
         if (!x)
                 return;
-        NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI4\n",
-                 spi, &iph->daddr);
-        ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_COMP, 0);
+
+        if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
+                ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_COMP, 0);
+        else
+                ipv4_redirect(skb, net, 0, 0, IPPROTO_COMP, 0);
         xfrm_state_put(x);
 }
 
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 715338a1b205..c2d0e6d8baaf 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -360,6 +360,8 @@ static int ipip_err(struct sk_buff *skb, u32 info)
                 if (code != ICMP_EXC_TTL)
                         return 0;
                 break;
+        case ICMP_REDIRECT:
+                break;
         }
 
         err = -ENOENT;
@@ -376,6 +378,13 @@ static int ipip_err(struct sk_buff *skb, u32 info)
                 goto out;
         }
 
+        if (type == ICMP_REDIRECT) {
+                ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0,
+                              IPPROTO_IPIP, 0);
+                err = 0;
+                goto out;
+        }
+
         if (t->parms.iph.daddr == 0)
                 goto out;
 
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 340fcf29a966..6232d476f37e 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -387,6 +387,7 @@ void ping_err(struct sk_buff *skb, u32 info)
                 break;
         case ICMP_REDIRECT:
                 /* See ICMP_SOURCE_QUENCH */
+                ipv4_sk_redirect(skb, sk);
                 err = EREMOTEIO;
                 break;
         }
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 659ddfb10947..ff0f071969ea 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -218,6 +218,8 @@ static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info)
 
         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
                 ipv4_sk_update_pmtu(skb, sk, info);
+        else if (type == ICMP_REDIRECT)
+                ipv4_sk_redirect(skb, sk);
 
         /* Report error on raw socket, if:
            1. User requested ip_recverr.
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 01545a3fc0f2..087a8488843f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -321,6 +321,14 @@ static void do_pmtu_discovery(struct sock *sk, const struct iphdr *iph, u32 mtu)
         } /* else let the usual retransmit timer handle it */
 }
 
+static void do_redirect(struct sk_buff *skb, struct sock *sk)
+{
+        struct dst_entry *dst = __sk_dst_check(sk, 0);
+
+        if (dst && dst->ops->redirect)
+                dst->ops->redirect(dst, skb);
+}
+
 /*
  * This routine is called by the ICMP module when it gets some
  * sort of error condition.  If err < 0 then the socket should
@@ -394,6 +402,9 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
         }
 
         switch (type) {
+        case ICMP_REDIRECT:
+                do_redirect(icmp_skb, sk);
+                goto out;
         case ICMP_SOURCE_QUENCH:
                 /* Just silently ignore these. */
                 goto out;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ee37d47d472e..b4c3582a991f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -630,6 +630,9 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
                         err = icmp_err_convert[code].errno;
                 }
                 break;
+        case ICMP_REDIRECT:
+                ipv4_sk_redirect(skb, sk);
+                break;
         }
 
         /*
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 87d3fcc302d4..258ebd7b268b 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -202,6 +202,15 @@ static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
         path->ops->update_pmtu(path, mtu);
 }
 
+static void xfrm4_redirect(struct dst_entry *dst, struct sk_buff *skb)
+{
+        struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
+        struct dst_entry *path = xdst->route;
+
+        if (path->ops->redirect)
+                path->ops->redirect(path, skb);
+}
+
 static void xfrm4_dst_destroy(struct dst_entry *dst)
 {
         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
@@ -225,6 +234,7 @@ static struct dst_ops xfrm4_dst_ops = {
         .protocol =             cpu_to_be16(ETH_P_IP),
         .gc =                   xfrm4_garbage_collect,
         .update_pmtu =          xfrm4_update_pmtu,
+        .redirect =             xfrm4_redirect,
         .cow_metrics =          dst_cow_metrics_generic,
         .destroy =              xfrm4_dst_destroy,
         .ifdown =               xfrm4_dst_ifdown,
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 80564fe03024..9fb4247f9a99 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -423,6 +423,18 @@ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
         sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
 }
 
+static void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t,
+                               struct sk_buff *skb)
+{
+        struct dst_entry *dst;
+
+        if (!t)
+                return;
+        dst = sctp_transport_dst_check(t);
+        if (dst && dst->ops->redirect)
+                dst->ops->redirect(dst, skb);
+}
+
 /*
  * SCTP Implementer's Guide, 2.37 ICMP handling procedures
  *
@@ -628,6 +640,10 @@ void sctp_v4_err(struct sk_buff *skb, __u32 info)
 
                 err = EHOSTUNREACH;
                 break;
+        case ICMP_REDIRECT:
+                sctp_icmp_redirect(sk, transport, skb);
+                err = 0;
+                break;
         default:
                 goto out_unlock;
         }