packet lib: ipv6: prepare to support extension headers

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: ipv6: support options for Hop-by-Hop Options header and destination header

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: ipv6: prepare to support Hop-by-Hop Options header and destination header

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: ipv6: support Hop-by-Hop Options header

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: ipv6: support destination header

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: ipv6: support fragment header

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: ipv6: support IP Authentication header

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: ipv6: add test for multi extension headers

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: ipv6: correct a comment

Signed-off-by: itoyuichi <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>