1 /** 2 * @file 3 * This is the IPv4 address tools implementation. 4 * 5 */ 6 7 /* 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without modification, 12 * are permitted provided that the following conditions are met: 13 * 14 * 1. Redistributions of source code must retain the above copyright notice, 15 * this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright notice, 17 * this list of conditions and the following disclaimer in the documentation 18 * and/or other materials provided with the distribution. 19 * 3. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 27 * OF 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) ARISING 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 31 * OF SUCH DAMAGE. 32 * 33 * This file is part of the lwIP TCP/IP stack. 34 * 35 * Author: Adam Dunkels <adam@sics.se> 36 * 37 */ 38 39 #include "lwip/opt.h" 40 41 #if LWIP_IPV4 42 43 #include "lwip/ip_addr.h" 44 #include "lwip/netif.h" 45 46 /* used by IP4_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */ 47 const ip_addr_t ip_addr_any = IPADDR4_INIT(IPADDR_ANY); 48 const ip_addr_t ip_addr_broadcast = IPADDR4_INIT(IPADDR_BROADCAST); 49 50 /** 51 * Determine if an address is a broadcast address on a network interface 52 * 53 * @param addr address to be checked 54 * @param netif the network interface against which the address is checked 55 * @return returns non-zero if the address is a broadcast address 56 */ 57 u8_t 58 ip4_addr_isbroadcast_u32(u32_t addr, const struct netif *netif) 59 { 60 ip4_addr_t ipaddr; 61 ip4_addr_set_u32(&ipaddr, addr); 62 63 /* all ones (broadcast) or all zeroes (old skool broadcast) */ 64 if ((~addr == IPADDR_ANY) || 65 (addr == IPADDR_ANY)) { 66 return 1; 67 /* no broadcast support on this network interface? */ 68 } else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) { 69 /* the given address cannot be a broadcast address 70 * nor can we check against any broadcast addresses */ 71 return 0; 72 /* address matches network interface address exactly? => no broadcast */ 73 } else if (addr == ip4_addr_get_u32(netif_ip4_addr(netif))) { 74 return 0; 75 /* on the same (sub) network... */ 76 } else if (ip4_addr_netcmp(&ipaddr, netif_ip4_addr(netif), netif_ip4_netmask(netif)) 77 /* ...and host identifier bits are all ones? =>... */ 78 && ((addr & ~ip4_addr_get_u32(netif_ip4_netmask(netif))) == 79 (IPADDR_BROADCAST & ~ip4_addr_get_u32(netif_ip4_netmask(netif))))) { 80 /* => network broadcast address */ 81 return 1; 82 } else { 83 return 0; 84 } 85 } 86 87 /** Checks if a netmask is valid (starting with ones, then only zeros) 88 * 89 * @param netmask the IPv4 netmask to check (in network byte order!) 90 * @return 1 if the netmask is valid, 0 if it is not 91 */ 92 u8_t 93 ip4_addr_netmask_valid(u32_t netmask) 94 { 95 u32_t mask; 96 u32_t nm_hostorder = lwip_htonl(netmask); 97 98 /* first, check for the first zero */ 99 for (mask = 1UL << 31 ; mask != 0; mask >>= 1) { 100 if ((nm_hostorder & mask) == 0) { 101 break; 102 } 103 } 104 /* then check that there is no one */ 105 for (; mask != 0; mask >>= 1) { 106 if ((nm_hostorder & mask) != 0) { 107 /* there is a one after the first zero -> invalid */ 108 return 0; 109 } 110 } 111 /* no one after the first zero -> valid */ 112 return 1; 113 } 114 115 /* Here for now until needed in other places in lwIP */ 116 #ifndef isprint 117 #define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up) 118 #define isprint(c) in_range(c, 0x20, 0x7f) 119 #define isdigit(c) in_range(c, '0', '9') 120 #define isxdigit(c) (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F')) 121 #define islower(c) in_range(c, 'a', 'z') 122 #define isspace(c) (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v') 123 #endif 124 125 /** 126 * Ascii internet address interpretation routine. 127 * The value returned is in network order. 128 * 129 * @param cp IP address in ascii representation (e.g. "127.0.0.1") 130 * @return ip address in network order 131 */ 132 u32_t 133 ipaddr_addr(const char *cp) 134 { 135 ip4_addr_t val; 136 137 if (ip4addr_aton(cp, &val)) { 138 return ip4_addr_get_u32(&val); 139 } 140 return (IPADDR_NONE); 141 } 142 143 /** 144 * Check whether "cp" is a valid ascii representation 145 * of an Internet address and convert to a binary address. 146 * Returns 1 if the address is valid, 0 if not. 147 * This replaces inet_addr, the return value from which 148 * cannot distinguish between failure and a local broadcast address. 149 * 150 * @param cp IP address in ascii representation (e.g. "127.0.0.1") 151 * @param addr pointer to which to save the ip address in network order 152 * @return 1 if cp could be converted to addr, 0 on failure 153 */ 154 int 155 ip4addr_aton(const char *cp, ip4_addr_t *addr) 156 { 157 u32_t val; 158 u8_t base; 159 char c; 160 u32_t parts[4]; 161 u32_t *pp = parts; 162 163 c = *cp; 164 for (;;) { 165 /* 166 * Collect number up to ``.''. 167 * Values are specified as for C: 168 * 0x=hex, 0=octal, 1-9=decimal. 169 */ 170 if (!isdigit(c)) { 171 return 0; 172 } 173 val = 0; 174 base = 10; 175 if (c == '0') { 176 c = *++cp; 177 if (c == 'x' || c == 'X') { 178 base = 16; 179 c = *++cp; 180 } else { 181 base = 8; 182 } 183 } 184 for (;;) { 185 if (isdigit(c)) { 186 val = (val * base) + (u32_t)(c - '0'); 187 c = *++cp; 188 } else if (base == 16 && isxdigit(c)) { 189 val = (val << 4) | (u32_t)(c + 10 - (islower(c) ? 'a' : 'A')); 190 c = *++cp; 191 } else { 192 break; 193 } 194 } 195 if (c == '.') { 196 /* 197 * Internet format: 198 * a.b.c.d 199 * a.b.c (with c treated as 16 bits) 200 * a.b (with b treated as 24 bits) 201 */ 202 if (pp >= parts + 3) { 203 return 0; 204 } 205 *pp++ = val; 206 c = *++cp; 207 } else { 208 break; 209 } 210 } 211 /* 212 * Check for trailing characters. 213 */ 214 if (c != '\0' && !isspace(c)) { 215 return 0; 216 } 217 /* 218 * Concoct the address according to 219 * the number of parts specified. 220 */ 221 switch (pp - parts + 1) { 222 223 case 0: 224 return 0; /* initial nondigit */ 225 226 case 1: /* a -- 32 bits */ 227 break; 228 229 case 2: /* a.b -- 8.24 bits */ 230 if (val > 0xffffffUL) { 231 return 0; 232 } 233 if (parts[0] > 0xff) { 234 return 0; 235 } 236 val |= parts[0] << 24; 237 break; 238 239 case 3: /* a.b.c -- 8.8.16 bits */ 240 if (val > 0xffff) { 241 return 0; 242 } 243 if ((parts[0] > 0xff) || (parts[1] > 0xff)) { 244 return 0; 245 } 246 val |= (parts[0] << 24) | (parts[1] << 16); 247 break; 248 249 case 4: /* a.b.c.d -- 8.8.8.8 bits */ 250 if (val > 0xff) { 251 return 0; 252 } 253 if ((parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff)) { 254 return 0; 255 } 256 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); 257 break; 258 default: 259 LWIP_ASSERT("unhandled", 0); 260 break; 261 } 262 if (addr) { 263 ip4_addr_set_u32(addr, lwip_htonl(val)); 264 } 265 return 1; 266 } 267 268 /** 269 * Convert numeric IP address into decimal dotted ASCII representation. 270 * returns ptr to static buffer; not reentrant! 271 * 272 * @param addr ip address in network order to convert 273 * @return pointer to a global static (!) buffer that holds the ASCII 274 * representation of addr 275 */ 276 char* 277 ip4addr_ntoa(const ip4_addr_t *addr) 278 { 279 static char str[IP4ADDR_STRLEN_MAX]; 280 return ip4addr_ntoa_r(addr, str, IP4ADDR_STRLEN_MAX); 281 } 282 283 /** 284 * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used. 285 * 286 * @param addr ip address in network order to convert 287 * @param buf target buffer where the string is stored 288 * @param buflen length of buf 289 * @return either pointer to buf which now holds the ASCII 290 * representation of addr or NULL if buf was too small 291 */ 292 char* 293 ip4addr_ntoa_r(const ip4_addr_t *addr, char *buf, int buflen) 294 { 295 u32_t s_addr; 296 char inv[3]; 297 char *rp; 298 u8_t *ap; 299 u8_t rem; 300 u8_t n; 301 u8_t i; 302 int len = 0; 303 304 s_addr = ip4_addr_get_u32(addr); 305 306 rp = buf; 307 ap = (u8_t *)&s_addr; 308 for (n = 0; n < 4; n++) { 309 i = 0; 310 do { 311 rem = *ap % (u8_t)10; 312 *ap /= (u8_t)10; 313 inv[i++] = (char)('0' + rem); 314 } while (*ap); 315 while (i--) { 316 if (len++ >= buflen) { 317 return NULL; 318 } 319 *rp++ = inv[i]; 320 } 321 if (len++ >= buflen) { 322 return NULL; 323 } 324 *rp++ = '.'; 325 ap++; 326 } 327 *--rp = 0; 328 return buf; 329 } 330 331 #endif /* LWIP_IPV4 */ 332