link_addr(3POSIX)

NAME | SYNOPSIS | API RESTRICTIONS | DESCRIPTION | RETURN VALUES | ATTRIBUTES | BUGS

NAME

link_addr, link_ntoa- elementary address specification routines for link level access

SYNOPSIS

$(OS_DIR)/lib/libc.a
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if_dl.h>

void link_addr(const char * addr, struct sockaddr_dl * sdl);
char *link_ntoa(const struct sockaddr_dl * sdl);

API RESTRICTIONS

The function or functions documented here may not be used safely in all application contexts with all APIs provided in the ChorusOS 5.0 product.

See API(5FEA) for details.

DESCRIPTION

The link_addr() routine interprets character strings representing link-level addresses, returning binary information suitable for use in system calls. The link_ntoa() routine takes a link-level address and returns an ASCII string representing some of the information present, including the link level address itself, and the interface name or number, if present. This facility is experimental and is still subject to change.

For link_addr() , the string addr may contain an optional network interface identifier of the form "name unit-number" , suitable for the first argument to ifconfig() (1M). This is followed in all cases by a colon and an interface address in the form of groups of hexadecimal digits separated by dots. Each group represents a byte of address; address bytes are filled left to right from low order bytes up to high order bytes.

Thus le0:8.0.9.13.d.30 represents an ethernet address to be transmitted on the first Lance ethernet interface.

RETURN VALUES

The link_ntoa() function always returns a null terminated string. The link_addr() function has no return value.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Evolving
MT-level	NOT MT-safe

BUGS

The returned values for () link_ntoa reside in a static memory area.

The function link_addr() should diagnose improperly formed input, and there should be an unambiguous way to recognize this.

If the sdl_len field of the link socket address sdl is 0, link_ntoa() will not insert a colon before the interface address bytes. If this translated address is given to link_addr() without inserting an initial colon, link_addr() will not interpret it correctly.

NAME | SYNOPSIS | API RESTRICTIONS | DESCRIPTION | RETURN VALUES | ATTRIBUTES | BUGS