From bf513fd6fc609590b7835c0dba624ccb9f8f9214 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Tue, 13 Oct 2015 13:42:56 +0200 Subject: 6lowpan: introduce LOWPAN_IPHC_MAX_HC_BUF_LEN This patch introduces the LOWPAN_IPHC_MAX_HC_BUF_LEN define which represent the worst-case supported IPHC buffer length. It's used to allocate the stack buffer space for creating the IPHC header. Signed-off-by: Alexander Aring Acked-by: Jukka Rissanen Signed-off-by: Marcel Holtmann --- include/net/6lowpan.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/net/6lowpan.h') diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h index 07db532696df..aa5a82380e4e 100644 --- a/include/net/6lowpan.h +++ b/include/net/6lowpan.h @@ -64,12 +64,20 @@ #define EUI64_ADDR_LEN 8 #define LOWPAN_NHC_MAX_ID_LEN 1 +/* Maximum next header compression length which we currently support inclusive + * possible inline data. + */ +#define LOWPAN_NHC_MAX_HDR_LEN (sizeof(struct udphdr)) /* Max IPHC Header len without IPv6 hdr specific inline data. * Useful for getting the "extra" bytes we need at worst case compression. * * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN */ #define LOWPAN_IPHC_MAX_HEADER_LEN (2 + 1 + LOWPAN_NHC_MAX_ID_LEN) +/* Maximum worst case IPHC header buffer size */ +#define LOWPAN_IPHC_MAX_HC_BUF_LEN (sizeof(struct ipv6hdr) + \ + LOWPAN_IPHC_MAX_HEADER_LEN + \ + LOWPAN_NHC_MAX_HDR_LEN) /* * ipv6 address based on mac -- cgit v1.2.1