ipv6: sr: update the struct ipv6_sr_hdr

The IPv6 Segment Routing Header (SRH) format has been updated (revision 6
of the SRH ietf draft). The update includes the following SRH fields:

(1) The "First Segment" field changed to be "Last Entry" which contains
the index, in the Segment List, of the last element of the Segment List.

(2) The 16 bit "reserved" field now is used as a "tag" which tags a packet
as part of a class or group of packets, e.g.,packets sharing the same
set of properties.

This patch updates the struct ipv6_sr_hdr, so it complies with the updated
SRH draft. The 16 bit "reserved" field is changed to be "tag", In addition
a comment is added to the "first_segment" field, showing that it represents
the "Last Entry" field of the SRH.

Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/seg6.h b/include/uapi/linux/seg6.h
index 2f6fb0dd613c09198c830c9059ba5f63e62f5de1..286e8d6a8e98a17a41fc2ffe380b9f68ba1704c0 100644 (file)
--- a/include/uapi/linux/seg6.h
+++ b/include/uapi/linux/seg6.h
@@ -26,9 +26,9 @@ struct ipv6_sr_hdr {
        __u8    hdrlen;
        __u8    type;
        __u8    segments_left;
-       __u8    first_segment;
+       __u8    first_segment; /* Represents the last_entry field of SRH */
        __u8    flags;
-       __u16   reserved;
+       __u16   tag;
 
        struct in6_addr segments[0];
 };