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authorAlexander Aring <alex.aring@gmail.com>2015-09-18 11:30:43 +0200
committerMarcel Holtmann <marcel@holtmann.org>2015-09-22 11:51:20 +0200
commit87a93e4eceb495f93e3f37b100334d2641765b6c (patch)
treed917662b1912a9788cdf431fc735b243e32dfb6c /include/net/6lowpan.h
parentieee802154: introduce wpan_dev_header_ops (diff)
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wireguard-linux-87a93e4eceb495f93e3f37b100334d2641765b6c.zip
ieee802154: change needed headroom/tailroom
This patch cleanups needed_headroom, needed_tailroom and hard_header_len fields for wpan and lowpan interfaces. For wpan interfaces the worst case mac header len should be part of needed_headroom, currently this is set as hard_header_len, but hard_header_len should be set to the minimum header length which xmit call assumes and this is the minimum frame length of 802.15.4. The hard_header_len value will check inside send callbacl of AF_PACKET raw sockets. For lowpan interfaces, if fragmentation isn't needed the skb will call dev_hard_header for 802154 layer and queue it afterwards. This happens without new skb allocation, so we need the same headroom and tailroom lengths like 802154 inside 802154 6lowpan layer. At least we assume as minimum header length an ipv6 header size. Signed-off-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'include/net/6lowpan.h')
-rw-r--r--include/net/6lowpan.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
index eeae5eb58754..c17f556644fc 100644
--- a/include/net/6lowpan.h
+++ b/include/net/6lowpan.h
@@ -61,6 +61,14 @@
#define UIP_PROTO_UDP 17 /* ipv6 next header value for UDP */
#define UIP_FRAGH_LEN 8 /* ipv6 fragment header size */
+#define LOWPAN_NHC_MAX_ID_LEN 1
+/* 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)
+
/*
* ipv6 address based on mac
* second bit-flip (Universe/Local) is done according RFC2464