Daniel-Constantin Mierla writes:
text representation can use ipv4 format for last 4 bytes:
http://tools.ietf.org/html/rfc4291#page-4
common for cases when tunneling ipv4 over ipv6.
That is:
(6 * 4 + 5) + 1 + (4 * 3 + 3) = 45
Then add 3 for the square brackets and the ending 0.
i just checked and str2ipv6 function does not support the embedded ipv4 format. also, i still claim that square brackets are delimiters and not part of the address. so 39 plus one more for zero byte would be fine.
-- juha