libc/inet/addr.c

   1 /* Copyright (C) 1995,1996 Robert de Bath <rdebath@cix.compulink.co.uk>
   2  * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
   3  *
   4  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
   5  */
   6
   7 /*
   8  * Manuel Novoa III       Dec 2000
   9  *
  10  * Converted to use my new (un)signed long (long) to string routines, which
  11  * are smaller than the previous functions and don't require static buffers.
  12  * In the process, removed the reference to strcat and cut object size of
  13  * inet_ntoa in half (from 190 bytes down to 94).
  14  *
  15  * Manuel Novoa III       Feb 2002
  16  *
  17  * Changed to use _int10tostr.
  18  */
  19
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <ctype.h>
  23 #include <netinet/in.h>
  24 #include <arpa/inet.h>
  25 #include <bits/uClibc_uintmaxtostr.h>
  26
  27 #ifdef L_inet_aton
  28 /*
  29  * More undocumented inet_aton features.
  30  * (read: uclibc doesnt support but glibc does)
  31  * http://www.mkssoftware.com/docs/man3/inet_aton.3.asp
  32  *
  33  * *cp can take the form of:
  34  * a.b.c.d    - {a,b,c,d} -> 1 byte
  35  * a.b.c      - {a,b}     -> 1 byte    {c} -> 2 bytes
  36  * a.b        - {a}       -> 1 byte    {b} -> 3 bytes
  37  * a          -                        {a} -> 4 bytes
  38  *
  39  * Each part may be decimal, octal, or hexadecimal as in ISO C.
  40  * 0x or 0X    -> hexadecimal
  41  * leading 0   -> octal
  42  * all else    -> decimal
  43  */
  44 int inet_aton(const char *cp, struct in_addr *addrptr)
  45 {
  46         in_addr_t addr;
  47         int value;
  48         int part;
  49
  50         if (cp == NULL) {
  51                 return 0;
  52         }
  53
  54         addr = 0;
  55         for (part = 1; part <= 4; part++) {
  56
  57                 if (!isdigit(*cp))
  58                         return 0;
  59
  60                 value = 0;
  61                 while (isdigit(*cp)) {
  62                         value *= 10;
  63                         value += *cp++ - '0';
  64                         if (value > 255)
  65                                 return 0;
  66                 }
  67
  68                 if (part < 4) {
  69                         if (*cp++ != '.')
  70                                 return 0;
  71                 } else {
  72                         char c = *cp++;
  73                         if (c != '\0' && !isspace(c))
  74                                 return 0;
  75                 }
  76
  77                 addr <<= 8;
  78                 addr |= value;
  79         }
  80
  81         /*  W. Richard Stevens in his book UNIX Network Programming,
  82          *  Volume 1, second edition, on page 71 says:
  83          *
  84          *  An undocumented feature of inet_aton is that if addrptr is
  85          *  a null pointer, the function still performs it validation
  86          *  of the input string, but does not store the result.
  87          */
  88         if (addrptr) {
  89                 addrptr->s_addr = htonl(addr);
  90         }
  91
  92         return 1;
  93 }
  94 libc_hidden_def(inet_aton)
  95 #endif
  96
  97 #ifdef L_inet_addr
  98
  99 in_addr_t inet_addr(const char *cp)
 100 {
 101         struct in_addr a;
 102
 103         if (!inet_aton(cp, &a))
 104                 return INADDR_NONE;
 105         else
 106                 return a.s_addr;
 107 }
 108 libc_hidden_def(inet_addr)
 109 #endif
 110
 111 #ifdef L_inet_ntoa
 112
 113 #define INET_NTOA_MAX_LEN       16      /* max 12 digits + 3 '.'s + 1 nul */
 114
 115 static char *__inet_ntoa_r(struct in_addr in, char buf[INET_NTOA_MAX_LEN])
 116 {
 117         in_addr_t addr = ntohl(in.s_addr);
 118         int i;
 119         char *p, *q;
 120
 121         q = 0;
 122         p = buf + INET_NTOA_MAX_LEN - 1; /* cannot use sizeof(buf) here */
 123         for (i = 0; i < 4; i++ ) {
 124                 p = _int10tostr(p, addr & 0xff) - 1;
 125                 addr >>= 8;
 126                 if (q) {
 127                         *q = '.';
 128                 }
 129                 q = p;
 130         }
 131
 132         return p+1;
 133 }
 134 strong_alias(__inet_ntoa_r,inet_ntoa_r)
 135
 136 char *inet_ntoa(struct in_addr in)
 137 {
 138         static char buf[INET_NTOA_MAX_LEN];
 139         return __inet_ntoa_r(in, buf);
 140 }
 141 libc_hidden_def(inet_ntoa)
 142 #endif
 143
 144 #ifdef L_inet_makeaddr
 145
 146 /* for some reason it does not remove the jump relocation */
 147
 148 /*
 149  * Formulate an Internet address from network + host.  Used in
 150  * building addresses stored in the ifnet structure.
 151  */
 152 struct in_addr inet_makeaddr(in_addr_t net, in_addr_t host)
 153 {
 154         struct in_addr in;
 155
 156         if (net < 128)
 157                 in.s_addr = (net << IN_CLASSA_NSHIFT) | (host & IN_CLASSA_HOST);
 158         else if (net < 65536)
 159                 in.s_addr = (net << IN_CLASSB_NSHIFT) | (host & IN_CLASSB_HOST);
 160         else if (net < 16777216UL)
 161                 in.s_addr = (net << IN_CLASSC_NSHIFT) | (host & IN_CLASSC_HOST);
 162         else
 163                 in.s_addr = net | host;
 164         in.s_addr = htonl(in.s_addr);
 165         return in;
 166 }
 167 libc_hidden_def(inet_makeaddr)
 168 #endif
 169
 170 #ifdef L_inet_lnaof
 171 /*
 172  * Return the local network address portion of an
 173  * internet address; handles class a/b/c network
 174  * number formats.
 175  */
 176 in_addr_t inet_lnaof(struct in_addr in)
 177 {
 178         in_addr_t i = ntohl(in.s_addr);
 179
 180         if (IN_CLASSA(i))
 181                 return (i & IN_CLASSA_HOST);
 182         else if (IN_CLASSB(i))
 183                 return (i & IN_CLASSB_HOST);
 184         else
 185                 return (i & IN_CLASSC_HOST);
 186 }
 187 #endif
 188
 189 #ifdef L_inet_netof
 190
 191 /*
 192  * Return the network number from an internet
 193  * address; handles class a/b/c network #'s.
 194  */
 195 in_addr_t
 196 inet_netof(struct in_addr in)
 197 {
 198         in_addr_t i = ntohl(in.s_addr);
 199
 200         if (IN_CLASSA(i))
 201                 return ((i & IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
 202         else if (IN_CLASSB(i))
 203                 return ((i & IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
 204         else
 205                 return ((i & IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
 206 }
 207 libc_hidden_def(inet_netof)
 208 #endif