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      1 /*	$NetBSD: inet_neta.c,v 1.3 2012/06/25 22:32:44 abs Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1996 by Internet Software Consortium.
      5  *
      6  * Permission to use, copy, modify, and distribute this software for any
      7  * purpose with or without fee is hereby granted, provided that the above
      8  * copyright notice and this permission notice appear in all copies.
      9  *
     10  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
     11  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
     12  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
     13  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
     14  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
     15  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
     16  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
     17  * SOFTWARE.
     18  */
     19 
     20 #include <sys/cdefs.h>
     21 #if defined(LIBC_SCCS) && !defined(lint)
     22 #if 0
     23 static const char rcsid[] = "Id: inet_neta.c,v 8.2 1996/08/08 06:54:44 vixie Exp ";
     24 #else
     25 __RCSID("$NetBSD: inet_neta.c,v 1.3 2012/06/25 22:32:44 abs Exp $");
     26 #endif
     27 #endif
     28 
     29 #include "namespace.h"
     30 #include <sys/types.h>
     31 #include <sys/socket.h>
     32 #include <netinet/in.h>
     33 #include <arpa/inet.h>
     34 
     35 #include <assert.h>
     36 #include <errno.h>
     37 #include <stdio.h>
     38 #include <string.h>
     39 
     40 #ifdef __weak_alias
     41 __weak_alias(inet_neta,_inet_neta)
     42 #endif
     43 
     44 /*
     45  * char *
     46  * inet_neta(src, dst, size)
     47  *	format a u_long network number into presentation format.
     48  * return:
     49  *	pointer to dst, or NULL if an error occurred (check errno).
     50  * note:
     51  *	format of ``src'' is as for inet_network().
     52  * author:
     53  *	Paul Vixie (ISC), July 1996
     54  */
     55 char *
     56 inet_neta(u_long src, char *dst, size_t size)
     57 {
     58 	char *odst = dst;
     59 	char *ep;
     60 	int advance;
     61 
     62 	_DIAGASSERT(dst != NULL);
     63 
     64 	if (src == 0x00000000) {
     65 		if (size < sizeof "0.0.0.0")
     66 			goto emsgsize;
     67 		strlcpy(dst, "0.0.0.0", size);
     68 		return dst;
     69 	}
     70 	ep = dst + size;
     71 	if (ep <= dst)
     72 		goto emsgsize;
     73 	while (src & 0xffffffffUL) {
     74 		u_char b = (u_char)((src & 0xff000000UL) >> 24);
     75 
     76 		src <<= 8;
     77 		if (b || src) {
     78 			advance = snprintf(dst, (size_t)(ep - dst), "%u", b);
     79 			if (advance <= 0 || advance >= ep - dst)
     80 				goto emsgsize;
     81 			dst += advance;
     82 			if (src != 0L) {
     83 				if (dst + 1 >= ep)
     84 					goto emsgsize;
     85 				*dst++ = '.';
     86 				*dst = '\0';
     87 			}
     88 		}
     89 	}
     90 	return (odst);
     91 
     92  emsgsize:
     93 	errno = EMSGSIZE;
     94 	return (NULL);
     95 }
     96