1 .\" $OpenBSD: link_addr.3,v 1.7 2000/04/18 03:01:32 aaron Exp $
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43 .Nd elementary address specification routines for link level access
45 .Fd #include <sys/types.h>
46 .Fd #include <sys/socket.h>
47 .Fd #include <net/if_dl.h>
49 .Fn link_addr "const char *addr" "struct sockaddr_dl *sdl"
51 .Fn link_ntoa "const struct sockaddr_dl *sdl"
55 function interprets character strings representing
56 link-level addresses, returning binary information suitable
57 for use in system calls.
61 address and returns an
63 string representing some of the information present,
64 including the link level address itself, and the interface name
65 or number, if present.
66 This facility is experimental and is
67 still subject to change.
74 an optional network interface identifier of the form
75 .Dq name unit-number ,
76 suitable for the first argument to
78 followed in all cases by a colon and
79 an interface address in the form of
80 groups of hexadecimal digits
82 Each group represents a byte of address;
83 address bytes are filled left to right from
84 low order bytes through high order bytes.
86 .\" A regular expression may make this format clearer:
87 .\" .Bd -literal -offset indent
88 .\" ([a-z]+[0-9]+:)?[0-9a-f]+(\e.[0-9a-f]+)*
93 represents an Ethernet address
94 to be transmitted on the first Lance Ethernet interface.
97 always returns a null-terminated string.
110 functions appeared in
113 The returned values for link_ntoa
114 reside in a static memory area.
118 should diagnose improperly formed input, and there should be an unambiguous
119 way to recognize this.
123 field of the link socket address
127 will not insert a colon before the interface address bytes.
128 If this translated address is given to
130 without inserting an initial colon,
131 the latter will not interpret it correctly.