inetpeer: Add redirect and PMTU discovery cached info.

Validity of the cached PMTU information is indicated by it's
expiration value being non-zero, just as per dst->expires.

The scheme we will use is that we will remember the pre-ICMP value
held in the metrics or route entry, and then at expiration time
we will restore that value.

In this way PMTU expiration does not kill off the cached route as is
done currently.

Redirect information is permanent, or at least until another redirect
is received.

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

diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index 60e2cd8d131901af415d35e301c81b1df9e517cf..e6dd8da6b2ad6207eb9f884e390bf62442820b75 100644 (file)
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -43,13 +43,17 @@ struct inet_peer {
         */
        union {
                struct {
-                       atomic_t        rid;            /* Frag reception counter */
-                       atomic_t        ip_id_count;    /* IP ID for the next packet */
-                       __u32           tcp_ts;
-                       __u32           tcp_ts_stamp;
-                       u32             metrics[RTAX_MAX];
-                       u32             rate_tokens;    /* rate limiting for ICMP */
-                       unsigned long   rate_last;
+                       atomic_t                        rid;            /* Frag reception counter */
+                       atomic_t                        ip_id_count;    /* IP ID for the next packet */
+                       __u32                           tcp_ts;
+                       __u32                           tcp_ts_stamp;
+                       u32                             metrics[RTAX_MAX];
+                       u32                             rate_tokens;    /* rate limiting for ICMP */
+                       unsigned long                   rate_last;
+                       unsigned long                   pmtu_expires;
+                       u32                             pmtu_orig;
+                       u32                             pmtu_learned;
+                       struct inetpeer_addr_base       redirect_learned;
                };
                struct rcu_head         rcu;
        };

diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index 4346c38763ae35ccc8d4c688ef033652ce252907..48f8d4592ccd220724efd7ca464f79beccc8329a 100644 (file)
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -515,6 +515,8 @@ struct inet_peer *inet_getpeer(struct inetpeer_addr *daddr, int create)
                p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;
                p->rate_tokens = 0;
                p->rate_last = 0;
+               p->pmtu_expires = 0;
+               memset(&p->redirect_learned, 0, sizeof(p->redirect_learned));
                INIT_LIST_HEAD(&p->unused);