From ad897db7ea66875c11e6187b6aff86a8642b8a83 Mon Sep 17 00:00:00 2001
From: Samuel Martin <samuel.martin@netatmo.com>
Date: Thu, 30 Jun 2022 16:36:57 +0200
Subject: [PATCH] ip4: Add IP4_MIN_MTU_LENGTH definition

See patch #10270

Signed-off-by: Samuel Martin <samuel.martin@netatmo.com>
Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>
---
 src/include/lwip/prot/ip4.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/include/lwip/prot/ip4.h b/src/include/lwip/prot/ip4.h
index b7d93761..f07db618 100644
--- a/src/include/lwip/prot/ip4.h
+++ b/src/include/lwip/prot/ip4.h
@@ -68,6 +68,9 @@ typedef struct ip4_addr_packed ip4_addr_p_t;
 /* Minimal fragment size in bytes (c.f. RFC 791) */
 #define IP_MIN_FRAG_LENGTH 8U
 
+/* Minimal IPv4 MTU (c.f. RFC 791) */
+#define IP4_MIN_MTU_LENGTH (IP_HLEN_MAX + IP_MIN_FRAG_LENGTH)
+
 #ifdef PACK_STRUCT_USE_INCLUDES
 #  include "arch/bpstruct.h"
 #endif