1 /* $NetBSD: inet_cidr_pton.c,v 1.10 2024/01/20 14:52:47 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 1.10 2024/01/20 14:52:47 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 <stddef.h> 44 #include <stdlib.h> 45 46 #include "port_after.h" 47 48 #ifdef __weak_alias 49 __weak_alias(inet_cidr_pton,_inet_cidr_pton) 50 #endif 51 52 static int inet_cidr_pton_ipv4(const char *src, u_char *dst, 53 int *bits, int ipv6); 54 static int inet_cidr_pton_ipv6(const char *src, u_char *dst, int *bits); 55 56 static int getbits(const char *, int ipv6); 57 58 /*% 59 * int 60 * inet_cidr_pton(af, src, dst, *bits) 61 * convert network address from presentation to network format. 62 * accepts inet_pton()'s input for this "af" plus trailing "/CIDR". 63 * "dst" is assumed large enough for its "af". "bits" is set to the 64 * /CIDR prefix length, which can have defaults (like /32 for IPv4). 65 * return: 66 * -1 if an error occurred (inspect errno; ENOENT means bad format). 67 * 0 if successful conversion occurred. 68 * note: 69 * 192.5.5.1/28 has a nonzero host part, which means it isn't a network 70 * as called for by inet_net_pton() but it can be a host address with 71 * an included netmask. 72 * author: 73 * Paul Vixie (ISC), October 1998 74 */ 75 int 76 inet_cidr_pton(int af, const char *src, void *dst, int *bits) { 77 switch (af) { 78 case AF_INET: 79 return inet_cidr_pton_ipv4(src, dst, bits, 0); 80 case AF_INET6: 81 return inet_cidr_pton_ipv6(src, dst, bits); 82 default: 83 errno = EAFNOSUPPORT; 84 return -1; 85 } 86 } 87 88 static const char digits[] = "0123456789"; 89 90 static int 91 inet_cidr_pton_ipv4(const char *src, u_char *dst, int *pbits, int ipv6) { 92 const u_char *odst = dst; 93 int ch, bits; 94 ptrdiff_t n, tmp; 95 size_t size = 4; 96 97 /* Get the mantissa. */ 98 while (ch = *src++, (isascii(ch) && isdigit(ch))) { 99 tmp = 0; 100 do { 101 n = strchr(digits, ch) - digits; 102 INSIST(n >= 0 && n <= 9); 103 tmp *= 10; 104 tmp += n; 105 if (tmp > 255) 106 goto enoent; 107 } while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch)); 108 if (size-- == 0U) 109 goto emsgsize; 110 *dst++ = (u_char) tmp; 111 if (ch == '\0' || ch == '/') 112 break; 113 if (ch != '.') 114 goto enoent; 115 } 116 117 /* Get the prefix length if any. */ 118 bits = -1; 119 if (ch == '/' && dst > odst) { 120 bits = getbits(src, ipv6); 121 if (bits == -2) 122 goto enoent; 123 } else if (ch != '\0') 124 goto enoent; 125 126 /* Prefix length can default to /32 only if all four octets spec'd. */ 127 if (bits == -1) { 128 if (dst - odst == 4) 129 bits = ipv6 ? 128 : 32; 130 else 131 goto enoent; 132 } 133 134 /* If nothing was written to the destination, we found no address. */ 135 if (dst == odst) 136 goto enoent; 137 138 /* If prefix length overspecifies mantissa, life is bad. */ 139 if (((bits - (ipv6 ? 96 : 0)) / 8) > (dst - odst)) 140 goto enoent; 141 142 /* Extend address to four octets. */ 143 while (size-- > 0U) 144 *dst++ = 0; 145 146 *pbits = bits; 147 return 0; 148 149 enoent: 150 errno = ENOENT; 151 return -1; 152 153 emsgsize: 154 errno = EMSGSIZE; 155 return -1; 156 } 157 158 static int 159 inet_cidr_pton_ipv6(const char *src, u_char *dst, int *pbits) { 160 static const char xdigits_l[] = "0123456789abcdef", 161 xdigits_u[] = "0123456789ABCDEF"; 162 u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp; 163 const char *xdigits, *curtok; 164 int ch, saw_xdigit; 165 u_int val; 166 int bits; 167 168 memset((tp = tmp), '\0', NS_IN6ADDRSZ); 169 endp = tp + NS_IN6ADDRSZ; 170 colonp = NULL; 171 /* Leading :: requires some special handling. */ 172 if (*src == ':') 173 if (*++src != ':') 174 return 0; 175 curtok = src; 176 saw_xdigit = 0; 177 val = 0; 178 bits = -1; 179 while ((ch = *src++) != '\0') { 180 const char *pch; 181 182 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL) 183 pch = strchr((xdigits = xdigits_u), ch); 184 if (pch != NULL) { 185 val <<= 4; 186 val |= (int)(pch - xdigits); 187 if (val > 0xffff) 188 return 0; 189 saw_xdigit = 1; 190 continue; 191 } 192 if (ch == ':') { 193 curtok = src; 194 if (!saw_xdigit) { 195 if (colonp) 196 return 0; 197 colonp = tp; 198 continue; 199 } else if (*src == '\0') { 200 return 0; 201 } 202 if (tp + NS_INT16SZ > endp) 203 return 0; 204 *tp++ = (u_char) (val >> 8) & 0xff; 205 *tp++ = (u_char) val & 0xff; 206 saw_xdigit = 0; 207 val = 0; 208 continue; 209 } 210 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) && 211 inet_cidr_pton_ipv4(curtok, tp, &bits, 1) == 0) { 212 tp += NS_INADDRSZ; 213 saw_xdigit = 0; 214 break; /*%< '\\0' was seen by inet_pton4(). */ 215 } 216 if (ch == '/') { 217 bits = getbits(src, 1); 218 if (bits == -2) 219 goto enoent; 220 break; 221 } 222 goto enoent; 223 } 224 if (saw_xdigit) { 225 if (tp + NS_INT16SZ > endp) 226 goto emsgsize; 227 *tp++ = (u_char) (val >> 8) & 0xff; 228 *tp++ = (u_char) val & 0xff; 229 } 230 if (colonp != NULL) { 231 /* 232 * Since some memmove()'s erroneously fail to handle 233 * overlapping regions, we'll do the shift by hand. 234 */ 235 const ptrdiff_t n = tp - colonp; 236 int i; 237 238 if (tp == endp) 239 goto enoent; 240 for (i = 1; i <= n; i++) { 241 endp[- i] = colonp[n - i]; 242 colonp[n - i] = 0; 243 } 244 tp = endp; 245 } 246 247 memcpy(dst, tmp, NS_IN6ADDRSZ); 248 249 *pbits = bits; 250 return 0; 251 252 enoent: 253 errno = ENOENT; 254 return -1; 255 256 emsgsize: 257 errno = EMSGSIZE; 258 return -1; 259 } 260 261 static int 262 getbits(const char *src, int ipv6) { 263 int bits = 0; 264 265 if (*src == '\0') /*%< syntax */ 266 return -2; 267 do { 268 char ch = *src++; 269 const char *cp = strchr(digits, ch); 270 if (cp == NULL) /*%< syntax */ 271 return -2; 272 bits *= 10; 273 bits += (int)(cp - digits); 274 if (bits == 0 && *src != '\0') /*%< no leading zeros */ 275 return -2; 276 if (bits > (ipv6 ? 128 : 32)) /*%< range error */ 277 return -2; 278 } while (*src != '\0'); 279 280 return bits; 281 } 282 283 /*! \file */ 284
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