inet_net.3
1 .\" $NetBSD: inet_net.3,v 1.4 1999/03/22 19:44:52 garbled Exp $ 2 .\" 3 .\" Copyright (c) 1997 The NetBSD Foundation, Inc. 4 .\" All rights reserved. 5 .\" 6 .\" This code is derived from software contributed to The NetBSD Foundation 7 .\" by Luke Mewburn. 8 .\" 9 .\" Redistribution and use in source and binary forms, with or without 10 .\" modification, are permitted provided that the following conditions 11 .\" are met: 12 .\" 1. Redistributions of source code must retain the above copyright 13 .\" notice, this list of conditions and the following disclaimer. 14 .\" 2. Redistributions in binary form must reproduce the above copyright 15 .\" notice, this list of conditions and the following disclaimer in the 16 .\" documentation and/or other materials provided with the distribution. 17 .\" 4. Neither the name of The NetBSD Foundation nor the names of its 18 .\" contributors may be used to endorse or promote products derived 19 .\" from this software without specific prior written permission. 20 .\" 21 .\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 22 .\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 23 .\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 24 .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 25 .\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 .\" POSSIBILITY OF SUCH DAMAGE. 32 .\" 33 .\" $FreeBSD: src/lib/libc/net/inet_net.3,v 1.4 2007/01/09 00:28:02 imp Exp $ 34 .\" 35 .Dd February 26, 2006 36 .Dt INET_NET 3 37 .Os 38 .Sh NAME 39 .Nm inet_net_ntop , 40 .Nm inet_net_pton 41 .Nd Internet network number manipulation routines 42 .Sh LIBRARY 43 .Lb libc 44 .Sh SYNOPSIS 45 .In arpa/inet.h 46 .Ft char * 47 .Fn inet_net_ntop "int af" "const void *src" "int bits" "char *dst" "size_t size" 48 .Ft int 49 .Fn inet_net_pton "int af" "const char *src" "void *dst" "size_t size" 50 .Sh DESCRIPTION 51 The 52 .Fn inet_net_ntop 53 function converts an Internet network number from network format (usually a 54 .Vt "struct in_addr" 55 or some other binary form, in network byte order) to CIDR presentation format 56 (suitable for external display purposes). 57 The 58 .Fa bits 59 argument 60 is the number of bits in 61 .Fa src 62 that are the network number. 63 It returns 64 .Dv NULL 65 if a system error occurs (in which case, 66 .Va errno 67 will have been set), or it returns a pointer to the destination string. 68 .Pp 69 The 70 .Fn inet_net_pton 71 function converts a presentation format Internet network number (that is, 72 printable form as held in a character string) to network format (usually a 73 .Vt "struct in_addr" 74 or some other internal binary representation, in network byte order). 75 It returns the number of bits (either computed based on the class, or 76 specified with /CIDR), or \-1 if a failure occurred 77 (in which case 78 .Va errno 79 will have been set. 80 It will be set to 81 .Er ENOENT 82 if the Internet network number was not valid). 83 .Pp 84 The currently supported values for 85 .Fa af 86 are 87 .Dv AF_INET 88 and 89 .Dv AF_INET6 . 90 The 91 .Fa size 92 argument 93 is the size of the result buffer 94 .Fa dst . 95 .Pp 96 .Sh NETWORK NUMBERS (IP VERSION 4) 97 Internet network numbers may be specified in one of the following forms: 98 .Bd -literal -offset indent 99 a.b.c.d/bits 100 a.b.c.d 101 a.b.c 102 a.b 103 a 104 .Ed 105 .Pp 106 When four parts are specified, each is interpreted 107 as a byte of data and assigned, from left to right, 108 to the four bytes of an Internet network number. 109 Note 110 that when an Internet network number is viewed as a 32-bit 111 integer quantity on a system that uses little-endian 112 byte order (such as the 113 .Tn Intel 386 , 486 , 114 and 115 .Tn Pentium 116 processors) the bytes referred to above appear as 117 .Dq Li d.c.b.a . 118 That is, little-endian bytes are ordered from right to left. 119 .Pp 120 When a three part number is specified, the last 121 part is interpreted as a 16-bit quantity and placed 122 in the rightmost two bytes of the Internet network number. 123 This makes the three part number format convenient 124 for specifying Class B network numbers as 125 .Dq Li 128.net.host . 126 .Pp 127 When a two part number is supplied, the last part 128 is interpreted as a 24-bit quantity and placed in 129 the rightmost three bytes of the Internet network number. 130 This makes the two part number format convenient 131 for specifying Class A network numbers as 132 .Dq Li net.host . 133 .Pp 134 When only one part is given, the value is stored 135 directly in the Internet network number without any byte 136 rearrangement. 137 .Pp 138 All numbers supplied as 139 .Dq parts 140 in a 141 .Ql \&. 142 notation 143 may be decimal, octal, or hexadecimal, as specified 144 in the C language (i.e., a leading 0x or 0X implies 145 hexadecimal; otherwise, a leading 0 implies octal; 146 otherwise, the number is interpreted as decimal). 147 .\" 148 .\" .Sh NETWORK NUMBERS (IP VERSION 6) 149 .\" XXX - document this! 150 .\" 151 .Sh LEGACY SYNOPSIS 152 .Fd #include <sys/types.h> 153 .Fd #include <sys/socket.h> 154 .Fd #include <netinet/in.h> 155 .Fd #include <arpa/inet.h> 156 .Pp 157 These include files were necessary for all functions. 158 .Sh SEE ALSO 159 .Xr byteorder 3 , 160 .Xr inet 3 , 161 .Xr networks 5 162 .Sh HISTORY 163 The 164 .Fn inet_net_ntop 165 and 166 .Fn inet_net_pton 167 functions appeared in BIND 4.9.4.