net: ipv6: Make max number of fragmented pkt configurable

If the user really wants, it is possible to increase the
maximum size of the fragmented packet. According to RFC 2460
chapter 5, we do not need to accept larger than 1500 byte IPv6
packets, so the max pkt limit is set to 2. But if really needed
the limit can be raised by defining NET_IPV6_FRAGMENTS_MAX_PKT
to some new value. Currently there is no Kconfig option for
doing this as it is unlikely that this is needed.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

subsys/net/ip/ipv6.h

@@ -374,7 +374,9 @@ static inline void net_ipv6_nbr_set_reachable_timer(struct net_if *iface,
  * This means that we should receive everything within first two fragments.
  * The first one being 1280 bytes and the second one 220 bytes.
  */
+#if !defined(NET_IPV6_FRAGMENTS_MAX_PKT)
 #define NET_IPV6_FRAGMENTS_MAX_PKT 2
+#endif
 
 /** Store pending IPv6 fragment information that is needed for reassembly. */
 struct net_ipv6_reassembly {