"""
    This C(ython) extension module provides an interface to the libsctp library and associated socket API.
"""

from sctp cimport *

cimport libc

def bindx (int sd, object addrs, int flags) :
    """
        Bind the given SOCK_SEQPACKET to the given set of local addresses.

            sd          the system socket FD
            addresses   the list of address tuples
            flags       one of SCTP_BINDX_ADD/REM_ADDR
    """
    
    # automatically allocated array of sockaddr_storage's for passing given addresses to sctp_bindx
    cdef libc.sockaddr_storage *addrs_out

    # used to iterate through addrs_out
    cdef libc.sockaddr_in *addr_in
    
    # number of addresses given
    cdef size_t addr_count = len(addrs)

    # alloc stack storage for converting addresses
    addrs_out = <libc.sockaddr_storage *> libc.alloca(addr_count * sizeof(libc.sockaddr_storage))

    for i, address in enumerate(addrs) :
        # XXX: assume socket-style IPv4 for now...
        addr, port = address

        addr_in = <libc.sockaddr_in *>(&addrs_out[i])
        
        addr_in.sin_family = libc.AF_INET
        addr_in.sin_port = libc.htons(port)

        # XXX: known broken
        libc.inet_aton(addr, &addr_in.sin_addr)
    
    return sctp_bindx(sd, <libc.sockaddr *>addrs_out, addr_count, flags)