1 /* $NetBSD: inet_cidr_pton.c,v 1.6 2009/04/12 17:07:16 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (c) 1998,1999 by Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 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_cidr_pton.c,v 1.6 2005/04/27 04:56:19 sra Exp"; 24 #else 25 __RCSID("$NetBSD: inet_cidr_pton.c,v 1.6 2009/04/12 17:07:16 christos Exp $"); 26 #endif 27 #endif 28 29 #include "port_before.h" 30 31 #include "namespace.h" 32 #include <sys/types.h> 33 #include <sys/socket.h> 34 #include <netinet/in.h> 35 #include <arpa/nameser.h> 36 #include <arpa/inet.h> 37 38 #include <isc/assertions.h> 39 #include <ctype.h> 40 #include <errno.h> 41 #include <stdio.h> 42 #include <string.h> 43 #include <stdlib.h> 44 45 #include "port_after.h" 46 47 #ifdef SPRINTF_CHAR 48 # define SPRINTF(x) strlen(sprintf/**/x) 49 #else 50 # define SPRINTF(x) ((size_t)sprintf x) 51 #endif 52 53 #ifdef __weak_alias 54 __weak_alias(inet_cidr_pton,_inet_cidr_pton) 55 #endif 56 57 static int inet_cidr_pton_ipv4 __P((const char *src, u_char *dst, 58 int *bits, int ipv6)); 59 static int inet_cidr_pton_ipv6 __P((const char *src, u_char *dst, 60 int *bits)); 61 62 static int getbits(const char *, int ipv6); 63 64 /*% 65 * int 66 * inet_cidr_pton(af, src, dst, *bits) 67 * convert network address from presentation to network format. 68 * accepts inet_pton()'s input for this "af" plus trailing "/CIDR". 69 * "dst" is assumed large enough for its "af". "bits" is set to the 70 * /CIDR prefix length, which can have defaults (like /32 for IPv4). 71 * return: 72 * -1 if an error occurred (inspect errno; ENOENT means bad format). 73 * 0 if successful conversion occurred. 74 * note: 75 * 192.5.5.1/28 has a nonzero host part, which means it isn't a network 76 * as called for by inet_net_pton() but it can be a host address with 77 * an included netmask. 78 * author: 79 * Paul Vixie (ISC), October 1998 80 */ 81 int 82 inet_cidr_pton(int af, const char *src, void *dst, int *bits) { 83 switch (af) { 84 case AF_INET: 85 return (inet_cidr_pton_ipv4(src, dst, bits, 0)); 86 case AF_INET6: 87 return (inet_cidr_pton_ipv6(src, dst, bits)); 88 default: 89 errno = EAFNOSUPPORT; 90 return (-1); 91 } 92 } 93 94 static const char digits[] = "0123456789"; 95 96 static int 97 inet_cidr_pton_ipv4(const char *src, u_char *dst, int *pbits, int ipv6) { 98 const u_char *odst = dst; 99 int n, ch, tmp, bits; 100 size_t size = 4; 101 102 /* Get the mantissa. */ 103 while (ch = *src++, (isascii(ch) && isdigit(ch))) { 104 tmp = 0; 105 do { 106 n = strchr(digits, ch) - digits; 107 INSIST(n >= 0 && n <= 9); 108 tmp *= 10; 109 tmp += n; 110 if (tmp > 255) 111 goto enoent; 112 } while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch)); 113 if (size-- == 0U) 114 goto emsgsize; 115 *dst++ = (u_char) tmp; 116 if (ch == '\0' || ch == '/') 117 break; 118 if (ch != '.') 119 goto enoent; 120 } 121 122 /* Get the prefix length if any. */ 123 bits = -1; 124 if (ch == '/' && dst > odst) { 125 bits = getbits(src, ipv6); 126 if (bits == -2) 127 goto enoent; 128 } else if (ch != '\0') 129 goto enoent; 130 131 /* Prefix length can default to /32 only if all four octets spec'd. */ 132 if (bits == -1) { 133 if (dst - odst == 4) 134 bits = ipv6 ? 128 : 32; 135 else 136 goto enoent; 137 } 138 139 /* If nothing was written to the destination, we found no address. */ 140 if (dst == odst) 141 goto enoent; 142 143 /* If prefix length overspecifies mantissa, life is bad. */ 144 if (((bits - (ipv6 ? 96 : 0)) / 8) > (dst - odst)) 145 goto enoent; 146 147 /* Extend address to four octets. */ 148 while (size-- > 0U) 149 *dst++ = 0; 150 151 *pbits = bits; 152 return (0); 153 154 enoent: 155 errno = ENOENT; 156 return (-1); 157 158 emsgsize: 159 errno = EMSGSIZE; 160 return (-1); 161 } 162 163 static int 164 inet_cidr_pton_ipv6(const char *src, u_char *dst, int *pbits) { 165 static const char xdigits_l[] = "0123456789abcdef", 166 xdigits_u[] = "0123456789ABCDEF"; 167 u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp; 168 const char *xdigits, *curtok; 169 int ch, saw_xdigit; 170 u_int val; 171 int bits; 172 173 memset((tp = tmp), '\0', NS_IN6ADDRSZ); 174 endp = tp + NS_IN6ADDRSZ; 175 colonp = NULL; 176 /* Leading :: requires some special handling. */ 177 if (*src == ':') 178 if (*++src != ':') 179 return (0); 180 curtok = src; 181 saw_xdigit = 0; 182 val = 0; 183 bits = -1; 184 while ((ch = *src++) != '\0') { 185 const char *pch; 186 187 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL) 188 pch = strchr((xdigits = xdigits_u), ch); 189 if (pch != NULL) { 190 val <<= 4; 191 val |= (pch - xdigits); 192 if (val > 0xffff) 193 return (0); 194 saw_xdigit = 1; 195 continue; 196 } 197 if (ch == ':') { 198 curtok = src; 199 if (!saw_xdigit) { 200 if (colonp) 201 return (0); 202 colonp = tp; 203 continue; 204 } else if (*src == '\0') { 205 return (0); 206 } 207 if (tp + NS_INT16SZ > endp) 208 return (0); 209 *tp++ = (u_char) (val >> 8) & 0xff; 210 *tp++ = (u_char) val & 0xff; 211 saw_xdigit = 0; 212 val = 0; 213 continue; 214 } 215 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) && 216 inet_cidr_pton_ipv4(curtok, tp, &bits, 1) == 0) { 217 tp += NS_INADDRSZ; 218 saw_xdigit = 0; 219 break; /*%< '\\0' was seen by inet_pton4(). */ 220 } 221 if (ch == '/') { 222 bits = getbits(src, 1); 223 if (bits == -2) 224 goto enoent; 225 break; 226 } 227 goto enoent; 228 } 229 if (saw_xdigit) { 230 if (tp + NS_INT16SZ > endp) 231 goto emsgsize; 232 *tp++ = (u_char) (val >> 8) & 0xff; 233 *tp++ = (u_char) val & 0xff; 234 } 235 if (colonp != NULL) { 236 /* 237 * Since some memmove()'s erroneously fail to handle 238 * overlapping regions, we'll do the shift by hand. 239 */ 240 const int n = tp - colonp; 241 int i; 242 243 if (tp == endp) 244 goto enoent; 245 for (i = 1; i <= n; i++) { 246 endp[- i] = colonp[n - i]; 247 colonp[n - i] = 0; 248 } 249 tp = endp; 250 } 251 252 memcpy(dst, tmp, NS_IN6ADDRSZ); 253 254 *pbits = bits; 255 return (0); 256 257 enoent: 258 errno = ENOENT; 259 return (-1); 260 261 emsgsize: 262 errno = EMSGSIZE; 263 return (-1); 264 } 265 266 static int 267 getbits(const char *src, int ipv6) { 268 int bits = 0; 269 char *cp, ch; 270 271 if (*src == '\0') /*%< syntax */ 272 return (-2); 273 do { 274 ch = *src++; 275 cp = strchr(digits, ch); 276 if (cp == NULL) /*%< syntax */ 277 return (-2); 278 bits *= 10; 279 bits += cp - digits; 280 if (bits == 0 && *src != '\0') /*%< no leading zeros */ 281 return (-2); 282 if (bits > (ipv6 ? 128 : 32)) /*%< range error */ 283 return (-2); 284 } while (*src != '\0'); 285 286 return (bits); 287 } 288 289 /*! \file */ 290