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 <alex.aring@gmail.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Alexander Aring 2015-10-13 13:42:56 +02:00 committed by Marcel Holtmann
parent cefdb801c8
commit bf513fd6fc
2 changed files with 9 additions and 1 deletions

View File

@ -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

View File

@ -429,7 +429,7 @@ int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
{
u8 tmp, iphc0, iphc1, *hc_ptr;
struct ipv6hdr *hdr;
u8 head[100] = {};
u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {};
int ret, addr_type;
if (type != ETH_P_IPV6)