Darran Shepherd
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AutoIpNetStack
Net stack with AutoIP enabled
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ip_addr.c
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00001 /** 00002 * @file 00003 * This is the IPv4 address tools implementation. 00004 * 00005 */ 00006 00007 /* 00008 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 00009 * All rights reserved. 00010 * 00011 * Redistribution and use in source and binary forms, with or without modification, 00012 * are permitted provided that the following conditions are met: 00013 * 00014 * 1. Redistributions of source code must retain the above copyright notice, 00015 * this list of conditions and the following disclaimer. 00016 * 2. Redistributions in binary form must reproduce the above copyright notice, 00017 * this list of conditions and the following disclaimer in the documentation 00018 * and/or other materials provided with the distribution. 00019 * 3. The name of the author may not be used to endorse or promote products 00020 * derived from this software without specific prior written permission. 00021 * 00022 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00023 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00024 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00025 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00026 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00027 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00028 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00029 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00030 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00031 * OF SUCH DAMAGE. 00032 * 00033 * This file is part of the lwIP TCP/IP stack. 00034 * 00035 * Author: Adam Dunkels <adam@sics.se> 00036 * 00037 */ 00038 00039 #include "lwip/opt.h" 00040 #include "lwip/ip_addr.h" 00041 #include "lwip/netif.h" 00042 00043 /* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */ 00044 const ip_addr_t ip_addr_any = { IPADDR_ANY }; 00045 const ip_addr_t ip_addr_broadcast = { IPADDR_BROADCAST }; 00046 00047 /** 00048 * Determine if an address is a broadcast address on a network interface 00049 * 00050 * @param addr address to be checked 00051 * @param netif the network interface against which the address is checked 00052 * @return returns non-zero if the address is a broadcast address 00053 */ 00054 u8_t ip_addr_isbroadcast(ip_addr_t *addr, struct netif *netif) 00055 { 00056 u32_t addr2test; 00057 00058 addr2test = ip4_addr_get_u32(addr); 00059 /* all ones (broadcast) or all zeroes (old skool broadcast) */ 00060 if ((~addr2test == IPADDR_ANY) || 00061 (addr2test == IPADDR_ANY)) 00062 return 1; 00063 /* no broadcast support on this network interface? */ 00064 else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) 00065 /* the given address cannot be a broadcast address 00066 * nor can we check against any broadcast addresses */ 00067 return 0; 00068 /* address matches network interface address exactly? => no broadcast */ 00069 else if (addr2test == ip4_addr_get_u32(&netif->ip_addr)) 00070 return 0; 00071 /* on the same (sub) network... */ 00072 else if (ip_addr_netcmp(addr, &(netif->ip_addr), &(netif->netmask)) 00073 /* ...and host identifier bits are all ones? =>... */ 00074 && ((addr2test & ~ip4_addr_get_u32(&netif->netmask)) == 00075 (IPADDR_BROADCAST & ~ip4_addr_get_u32(&netif->netmask)))) 00076 /* => network broadcast address */ 00077 return 1; 00078 else 00079 return 0; 00080 } 00081 00082 /* Here for now until needed in other places in lwIP */ 00083 #ifndef isprint 00084 #define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up) 00085 #define isprint(c) in_range(c, 0x20, 0x7f) 00086 #define isdigit(c) in_range(c, '0', '9') 00087 #define isxdigit(c) (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F')) 00088 #define islower(c) in_range(c, 'a', 'z') 00089 #define isspace(c) (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v') 00090 #endif 00091 00092 /** 00093 * Ascii internet address interpretation routine. 00094 * The value returned is in network order. 00095 * 00096 * @param cp IP address in ascii represenation (e.g. "127.0.0.1") 00097 * @return ip address in network order 00098 */ 00099 u32_t 00100 ipaddr_addr(const char *cp) 00101 { 00102 ip_addr_t val; 00103 00104 if (ipaddr_aton(cp, &val)) { 00105 return ip4_addr_get_u32(&val); 00106 } 00107 return (IPADDR_NONE); 00108 } 00109 00110 /** 00111 * Check whether "cp" is a valid ascii representation 00112 * of an Internet address and convert to a binary address. 00113 * Returns 1 if the address is valid, 0 if not. 00114 * This replaces inet_addr, the return value from which 00115 * cannot distinguish between failure and a local broadcast address. 00116 * 00117 * @param cp IP address in ascii represenation (e.g. "127.0.0.1") 00118 * @param addr pointer to which to save the ip address in network order 00119 * @return 1 if cp could be converted to addr, 0 on failure 00120 */ 00121 int 00122 ipaddr_aton(const char *cp, ip_addr_t *addr) 00123 { 00124 u32_t val; 00125 u8_t base; 00126 char c; 00127 u32_t parts[4]; 00128 u32_t *pp = parts; 00129 00130 c = *cp; 00131 for (;;) { 00132 /* 00133 * Collect number up to ``.''. 00134 * Values are specified as for C: 00135 * 0x=hex, 0=octal, 1-9=decimal. 00136 */ 00137 if (!isdigit(c)) 00138 return (0); 00139 val = 0; 00140 base = 10; 00141 if (c == '0') { 00142 c = *++cp; 00143 if (c == 'x' || c == 'X') { 00144 base = 16; 00145 c = *++cp; 00146 } else 00147 base = 8; 00148 } 00149 for (;;) { 00150 if (isdigit(c)) { 00151 val = (val * base) + (int)(c - '0'); 00152 c = *++cp; 00153 } else if (base == 16 && isxdigit(c)) { 00154 val = (val << 4) | (int)(c + 10 - (islower(c) ? 'a' : 'A')); 00155 c = *++cp; 00156 } else 00157 break; 00158 } 00159 if (c == '.') { 00160 /* 00161 * Internet format: 00162 * a.b.c.d 00163 * a.b.c (with c treated as 16 bits) 00164 * a.b (with b treated as 24 bits) 00165 */ 00166 if (pp >= parts + 3) 00167 return (0); 00168 *pp++ = val; 00169 c = *++cp; 00170 } else 00171 break; 00172 } 00173 /* 00174 * Check for trailing characters. 00175 */ 00176 if (c != '\0' && !isspace(c)) 00177 return (0); 00178 /* 00179 * Concoct the address according to 00180 * the number of parts specified. 00181 */ 00182 switch (pp - parts + 1) { 00183 00184 case 0: 00185 return (0); /* initial nondigit */ 00186 00187 case 1: /* a -- 32 bits */ 00188 break; 00189 00190 case 2: /* a.b -- 8.24 bits */ 00191 if (val > 0xffffffUL) 00192 return (0); 00193 val |= parts[0] << 24; 00194 break; 00195 00196 case 3: /* a.b.c -- 8.8.16 bits */ 00197 if (val > 0xffff) 00198 return (0); 00199 val |= (parts[0] << 24) | (parts[1] << 16); 00200 break; 00201 00202 case 4: /* a.b.c.d -- 8.8.8.8 bits */ 00203 if (val > 0xff) 00204 return (0); 00205 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8); 00206 break; 00207 } 00208 if (addr) { 00209 ip4_addr_set_u32(addr, htonl(val)); 00210 } 00211 return (1); 00212 } 00213 00214 /** 00215 * Convert numeric IP address into decimal dotted ASCII representation. 00216 * returns ptr to static buffer; not reentrant! 00217 * 00218 * @param addr ip address in network order to convert 00219 * @return pointer to a global static (!) buffer that holds the ASCII 00220 * represenation of addr 00221 */ 00222 char * 00223 ipaddr_ntoa(ip_addr_t *addr) 00224 { 00225 static char str[16]; 00226 return ipaddr_ntoa_r(addr, str, 16); 00227 } 00228 00229 /** 00230 * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used. 00231 * 00232 * @param addr ip address in network order to convert 00233 * @param buf target buffer where the string is stored 00234 * @param buflen length of buf 00235 * @return either pointer to buf which now holds the ASCII 00236 * representation of addr or NULL if buf was too small 00237 */ 00238 char *ipaddr_ntoa_r(ip_addr_t *addr, char *buf, int buflen) 00239 { 00240 u32_t s_addr; 00241 char inv[3]; 00242 char *rp; 00243 u8_t *ap; 00244 u8_t rem; 00245 u8_t n; 00246 u8_t i; 00247 int len = 0; 00248 00249 s_addr = ip4_addr_get_u32(addr); 00250 00251 rp = buf; 00252 ap = (u8_t *)&s_addr; 00253 for(n = 0; n < 4; n++) { 00254 i = 0; 00255 do { 00256 rem = *ap % (u8_t)10; 00257 *ap /= (u8_t)10; 00258 inv[i++] = '0' + rem; 00259 } while(*ap); 00260 while(i--) { 00261 if (len++ >= buflen) { 00262 return NULL; 00263 } 00264 *rp++ = inv[i]; 00265 } 00266 if (len++ >= buflen) { 00267 return NULL; 00268 } 00269 *rp++ = '.'; 00270 ap++; 00271 } 00272 *--rp = 0; 00273 return buf; 00274 }
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