References (1)

Textbooks
Gary Wright and Richard Stevens, "TCP/IP Illustrated vol. 2: The implementation", Addison Wesley
kernel programmers MUST read this book.
Richard Stevens, "UNIX Network Programming 2nd edition, vol. 1", Prentice Hall
a good book, but (unfortunately) the description and samples of IPv6 API are too old to refer to...
Brian Kernighan and Rob Pike, "The Practice of Programming", Addison Wesley

Specifications
"POSIX Programmer's Guide", O'reilly
RFC2553, draft-ietf-ipngwg-rfc2553bis-xx.txt
RFC2292, draft-ietf-ipngwg-rfc2292bis-xx.txt