/*
 * This library module implements a function that helps initialize
 * sockaddr for bind or connect operations on UNIX domain sockets.
 *
 * Back when I programmed under 4.3BSD UNIX, this operation was simple
 * and straightforward - but under "modern" Unixes, it appears to be
 * a complex affair, given the messy code (originally copied from
 * Osmocom) that appears in FreeCalypso host tools for the rvinterf
 * local socket interface.  Hence I am factoring that mess out into
 * its own library function this time around.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <string.h>
#include <strings.h>

void
fill_sockaddr_un(pathname, sunp, lenp)
	char *pathname;
	struct sockaddr_un *sunp;
	unsigned *lenp;
{
	/* local socket binding voodoo copied from osmocon */
	sunp->sun_family = AF_UNIX;
	strncpy(sunp->sun_path, pathname, sizeof(sunp->sun_path));
	sunp->sun_path[sizeof(sunp->sun_path) - 1] = '\0';
	/* we use the same magic that X11 uses in Xtranssock.c for
	 * calculating the proper length of the sockaddr */
#if defined(BSD44SOCKETS) || defined(__UNIXWARE__)
	sunp->sun_len = strlen(sunp->sun_path);
#endif
#if defined(BSD44SOCKETS) || defined(SUN_LEN)
	*lenp = SUN_LEN(sunp);
#else
	*lenp = strlen(sunp->sun_path) +
		offsetof(struct sockaddr_un, sun_path) + 1;
#endif
}