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 (at) sics.se> 36 * 37 */ 38 39 #include "lwip/opt.h" 40 #include "lwip/ip_addr.h" 41 #include "lwip/netif.h" 42 43 /* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */ 44 const ip_addr_t ip_addr_any = { IPADDR_ANY }; 45 const ip_addr_t ip_addr_broadcast = { IPADDR_BROADCAST }; 46 47 /** 48 * Determine if an address is a broadcast address on a network interface 49 * 50 * @param addr address to be checked 51 * @param netif the network interface against which the address is checked 52 * @return returns non-zero if the address is a broadcast address 53 */ 54 u8_t 55 ip4_addr_isbroadcast(u32_t addr, const struct netif *netif) 56 { 57 ip_addr_t ipaddr; 58 ip4_addr_set_u32(&ipaddr, addr); 59 60 /* all ones (broadcast) or all zeroes (old skool broadcast) */ 61 if ((~addr == IPADDR_ANY) || 62 (addr == IPADDR_ANY)) { 63 return 1; 64 /* no broadcast support on this network interface? */ 65 } else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) { 66 /* the given address cannot be a broadcast address 67 * nor can we check against any broadcast addresses */ 68 return 0; 69 /* address matches network interface address exactly? => no broadcast */ 70 } else if (addr == ip4_addr_get_u32(&netif->ip_addr)) { 71 return 0; 72 /* on the same (sub) network... */ 73 } else if (ip_addr_netcmp(&ipaddr, &(netif->ip_addr), &(netif->netmask)) 74 /* ...and host identifier bits are all ones? =>... */ 75 && ((addr & ~ip4_addr_get_u32(&netif->netmask)) == 76 (IPADDR_BROADCAST & ~ip4_addr_get_u32(&netif->netmask)))) { 77 /* => network broadcast address */ 78 return 1; 79 } else { 80 return 0; 81 } 82 } 83 84 /** Checks if a netmask is valid (starting with ones, then only zeros) 85 * 86 * @param netmask the IPv4 netmask to check (in network byte order!) 87 * @return 1 if the netmask is valid, 0 if it is not 88 */ 89 u8_t 90 ip4_addr_netmask_valid(u32_t netmask) 91 { 92 u32_t mask; 93 u32_t nm_hostorder = lwip_htonl(netmask); 94 95 /* first, check for the first zero */ 96 for (mask = 1UL << 31 ; mask != 0; mask >>= 1) { 97 if ((nm_hostorder & mask) == 0) { 98 break; 99 } 100 } 101 /* then check that there is no one */ 102 for (; mask != 0; mask >>= 1) { 103 if ((nm_hostorder & mask) != 0) { 104 /* there is a one after the first zero -> invalid */ 105 return 0; 106 } 107 } 108 /* no one after the first zero -> valid */ 109 return 1; 110 } 111 112 /* Here for now until needed in other places in lwIP */ 113 #ifndef isprint 114 #define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up) 115 #define isprint(c) in_range(c, 0x20, 0x7f) 116 #define isdigit(c) in_range(c, '0', '9') 117 #define isxdigit(c) (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F')) 118 #define islower(c) in_range(c, 'a', 'z') 119 #define isspace(c) (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v') 120 #endif 121 122 /** 123 * Ascii internet address interpretation routine. 124 * The value returned is in network order. 125 * 126 * @param cp IP address in ascii represenation (e.g. "127.0.0.1") 127 * @return ip address in network order 128 */ 129 u32_t 130 ipaddr_addr(const char *cp) 131 { 132 ip_addr_t val; 133 134 if (ipaddr_aton(cp, &val)) { 135 return ip4_addr_get_u32(&val); 136 } 137 return (IPADDR_NONE); 138 } 139 140 /** 141 * Check whether "cp" is a valid ascii representation 142 * of an Internet address and convert to a binary address. 143 * Returns 1 if the address is valid, 0 if not. 144 * This replaces inet_addr, the return value from which 145 * cannot distinguish between failure and a local broadcast address. 146 * 147 * @param cp IP address in ascii represenation (e.g. "127.0.0.1") 148 * @param addr pointer to which to save the ip address in network order 149 * @return 1 if cp could be converted to addr, 0 on failure 150 */ 151 int 152 ipaddr_aton(const char *cp, ip_addr_t *addr) 153 { 154 u32_t val; 155 u8_t base; 156 char c; 157 u32_t parts[4]; 158 u32_t *pp = parts; 159 160 c = *cp; 161 for (;;) { 162 /* 163 * Collect number up to ``.''. 164 * Values are specified as for C: 165 * 0x=hex, 0=octal, 1-9=decimal. 166 */ 167 if (!isdigit(c)) 168 return (0); 169 val = 0; 170 base = 10; 171 if (c == '0') { 172 c = *++cp; 173 if (c == 'x' || c == 'X') { 174 base = 16; 175 c = *++cp; 176 } else 177 base = 8; 178 } 179 for (;;) { 180 if (isdigit(c)) { 181 val = (val * base) + (int)(c - '0'); 182 c = *++cp; 183 } else if (base == 16 && isxdigit(c)) { 184 val = (val << 4) | (int)(c + 10 - (islower(c) ? 'a' : 'A')); 185 c = *++cp; 186 } else 187 break; 188 } 189 if (c == '.') { 190 /* 191 * Internet format: 192 * a.b.c.d 193 * a.b.c (with c treated as 16 bits) 194 * a.b (with b treated as 24 bits) 195 */ 196 if (pp >= parts + 3) { 197 return (0); 198 } 199 *pp++ = val; 200 c = *++cp; 201 } else 202 break; 203 } 204 /* 205 * Check for trailing characters. 206 */ 207 if (c != '\0' && !isspace(c)) { 208 return (0); 209 } 210 /* 211 * Concoct the address according to 212 * the number of parts specified. 213 */ 214 switch (pp - parts + 1) { 215 216 case 0: 217 return (0); /* initial nondigit */ 218 219 case 1: /* a -- 32 bits */ 220 break; 221 222 case 2: /* a.b -- 8.24 bits */ 223 if (val > 0xffffffUL) { 224 return (0); 225 } 226 val |= parts[0] << 24; 227 break; 228 229 case 3: /* a.b.c -- 8.8.16 bits */ 230 if (val > 0xffff) { 231 return (0); 232 } 233 val |= (parts[0] << 24) | (parts[1] << 16); 234 break; 235 236 case 4: /* a.b.c.d -- 8.8.8.8 bits */ 237 if (val > 0xff) { 238 return (0); 239 } 240 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); 241 break; 242 default: 243 LWIP_ASSERT("unhandled", 0); 244 break; 245 } 246 if (addr) { 247 ip4_addr_set_u32(addr, htonl(val)); 248 } 249 return (1); 250 } 251 252 /** 253 * Convert numeric IP address into decimal dotted ASCII representation. 254 * returns ptr to static buffer; not reentrant! 255 * 256 * @param addr ip address in network order to convert 257 * @return pointer to a global static (!) buffer that holds the ASCII 258 * represenation of addr 259 */ 260 char * 261 ipaddr_ntoa(const ip_addr_t *addr) 262 { 263 static char str[16]; 264 return ipaddr_ntoa_r(addr, str, 16); 265 } 266 267 /** 268 * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used. 269 * 270 * @param addr ip address in network order to convert 271 * @param buf target buffer where the string is stored 272 * @param buflen length of buf 273 * @return either pointer to buf which now holds the ASCII 274 * representation of addr or NULL if buf was too small 275 */ 276 char *ipaddr_ntoa_r(const ip_addr_t *addr, char *buf, int buflen) 277 { 278 u32_t s_addr; 279 char inv[3]; 280 char *rp; 281 u8_t *ap; 282 u8_t rem; 283 u8_t n; 284 u8_t i; 285 int len = 0; 286 287 s_addr = ip4_addr_get_u32(addr); 288 289 rp = buf; 290 ap = (u8_t *)&s_addr; 291 for(n = 0; n < 4; n++) { 292 i = 0; 293 do { 294 rem = *ap % (u8_t)10; 295 *ap /= (u8_t)10; 296 inv[i++] = '0' + rem; 297 } while(*ap); 298 while(i--) { 299 if (len++ >= buflen) { 300 return NULL; 301 } 302 *rp++ = inv[i]; 303 } 304 if (len++ >= buflen) { 305 return NULL; 306 } 307 *rp++ = '.'; 308 ap++; 309 } 310 *--rp = 0; 311 return buf; 312 } 313