@@ -32,6 +32,11 @@ struct route_info {
#define RT6_LOOKUP_F_SRCPREF_PUBLIC 0x00000010
#define RT6_LOOKUP_F_SRCPREF_COA 0x00000020
+/* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
+ * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header
+ */
+#define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr))
+
/*
* rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
* between IPV6_ADDR_PREFERENCES socket option values
@@ -1324,7 +1324,7 @@ static unsigned int ip6_mtu(const struct dst_entry *dst)
unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
if (mtu)
- return mtu;
+ goto out;
mtu = IPV6_MIN_MTU;
@@ -1334,7 +1334,8 @@ static unsigned int ip6_mtu(const struct dst_entry *dst)
mtu = idev->cnf.mtu6;
rcu_read_unlock();
- return mtu;
+out:
+ return min_t(unsigned int, mtu, IP6_MAX_MTU);
}
static struct dst_entry *icmp6_dst_gc_list;