NAME

     ngatmbase — netgraph ATM utility module

SYNOPSIS

     #include <netnatm/unimsg.h>
     #include <netgraph/atm/ngatmbase.h>

     struct mbuf *
     uni_msg_pack_mbuf(struct uni_msg *msg, void *hdr, size_t len);

     struct uni_msg *
     uni_msg_alloc(size_t len);

     struct uni_msg *
     uni_msg_build(void *buf, ...);

     void
     uni_msg_destroy(struct uni_msg *msg);

     int
     uni_msg_unpack_mbuf(struct mbuf *m, struct uni_msg *msgp);

DESCRIPTION

     This module provides utility functions for the handling of signalling messages to the NgATM
     modules.

     The uni_msg_pack_mbuf() function packs a message into one or several mbufs optionally
     prepending a header.  The header is given by its address hdr and length len.  If hdr is NULL
     or len equals 0, no header is prepended.  Either msg or hdr may be NULL but not both.  The
     uni_msg_pack_mbuf() function returns a pointer to the allocated mbuf chain or NULL in the
     case of an error.

     The uni_msg_alloc() function allocates a new message with space for at least len bytes.  In
     the case of an error NULL is returned.

     The uni_msg_build() function constructs a message from pieces.  Each piece is given by a
     pair of arguments, the first of type void * and the second a size_t.  The list of pieces
     must be terminated by (void *)NULL.

     The uni_msg_destroy() function destroys the messages and frees all the messages's memory.

     The uni_msg_unpack_mbuf() function unpacks an mbuf chain info a uni_msg.  A pointer to the
     newly allocated message is stored in msgp and 0 is returned.  In the case of an error
     (either when no packet header is found in the first mbuf or memory cannot be allocated) the
     function returns an appropriate error code.

SEE ALSO

     ng_ccatm(4), ng_sscfu(4), ng_sscop(4), ng_uni(4)

AUTHORS

     Harti Brandt <harti@FreeBSD.org>