lib/libc/net/addr2ascii.c

   1 /*
   2  * Copyright 1996 Massachusetts Institute of Technology
   3  *
   4  * Permission to use, copy, modify, and distribute this software and
   5  * its documentation for any purpose and without fee is hereby
   6  * granted, provided that both the above copyright notice and this
   7  * permission notice appear in all copies, that both the above
   8  * copyright notice and this permission notice appear in all
   9  * supporting documentation, and that the name of M.I.T. not be used
  10  * in advertising or publicity pertaining to distribution of the
  11  * software without specific, written prior permission.  M.I.T. makes
  12  * no representations about the suitability of this software for any
  13  * purpose.  It is provided "as is" without express or implied
  14  * warranty.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
  17  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
  18  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
  20  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  23  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  26  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $ANA: addr2ascii.c,v 1.1 1996/06/13 18:41:46 wollman Exp $
  30  * $DragonFly: src/lib/libc/net/addr2ascii.c,v 1.2 2005/11/13 03:04:47 swildner Exp $
  31  */
  32
  33 #include <sys/types.h>
  34 #include <sys/socket.h>
  35
  36 #include <errno.h>
  37 #include <string.h>
  38
  39 #include <net/if_dl.h>
  40 #include <netinet/in.h>
  41 #include <arpa/inet.h>
  42
  43 /*-
  44  * Convert a network address from binary to printable numeric format.
  45  * This API is copied from INRIA's IPv6 implementation, but it is a
  46  * bit bogus in two ways:
  47  *
  48  *      1) There is no value in passing both an address family and
  49  *         an address length; either one should imply the other,
  50  *         or we should be passing sockaddrs instead.
  51  *      2) There should by contrast be /added/ a length for the buffer
  52  *         that we pass in, so that programmers are spared the need to
  53  *         manually calculate (read: ``guess'') the maximum length.
  54  *
  55  * Flash: the API is also the same in the NRL implementation, and seems to
  56  * be some sort of standard, so we appear to be stuck with both the bad
  57  * naming and the poor choice of arguments.
  58  */
  59 char *
  60 addr2ascii(int af,
  61            const void *addrp,
  62            int len,             /* should be size_t XXX */
  63            char *buf)           /* XXX should pass length of buffer */
  64 {
  65         static char staticbuf[64]; /* 64 for AF_LINK > 16 for AF_INET */
  66
  67         if (!buf)
  68                 buf = staticbuf;
  69
  70         switch(af) {
  71         case AF_INET:
  72                 if (len != sizeof(struct in_addr)) {
  73                         errno = ENAMETOOLONG;
  74                         return 0;
  75                 }
  76                 strcpy(buf, inet_ntoa(*(const struct in_addr *)addrp));
  77                 break;
  78
  79         case AF_LINK:
  80                 if (len != sizeof(struct sockaddr_dl)) {
  81                         errno = ENAMETOOLONG;
  82                         return 0;
  83                 }
  84                 strcpy(buf, link_ntoa((const struct sockaddr_dl *)addrp));
  85                 break;
  86
  87         default:
  88                 errno = EPROTONOSUPPORT;
  89                 return 0;
  90         }
  91         return buf;
  92 }