mbed official / lwip

Official mbed lwIP library (version 1.4.0)

Dependents:   LwIPNetworking NetServicesMin EthernetInterface EthernetInterface_RSF ... more

Legacy Networking Libraries

This is an mbed 2 networking library. For mbed OS 5, lwip has been integrated with built-in networking interfaces. The networking libraries have been revised to better support additional network stacks and thread safety here.

This library is based on the code of lwIP v1.4.0

Copyright (c) 2001, 2002 Swedish Institute of Computer Science.
All rights reserved. 

Redistribution and use in source and binary forms, with or without modification, 
are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
   derived from this software without specific prior written permission. 

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
OF SUCH DAMAGE.

core/ipv4/ip_addr.c@20:08f08bfc3f3d, 2016-03-14 (annotated)

Committer:
mbed_official
Date:
Mon Mar 14 16:15:36 2016 +0000
Revision:
20:08f08bfc3f3d
Parent:
0:51ac1d130fd4 
Synchronized with git revision fec574a5ed6db26aca1b13992ff271bf527d4a0d



Full URL: https://github.com/mbedmicro/mbed/commit/fec574a5ed6db26aca1b13992ff271bf527d4a0d/



Increased allocated netbufs to handle DTLS handshakes

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 0:51ac1d130fd4 1 /**
mbed_official 0:51ac1d130fd4 2 * @file
mbed_official 0:51ac1d130fd4 3 * This is the IPv4 address tools implementation.
mbed_official 0:51ac1d130fd4 4 *
mbed_official 0:51ac1d130fd4 5 */
mbed_official 0:51ac1d130fd4 6
mbed_official 0:51ac1d130fd4 7 /*
mbed_official 0:51ac1d130fd4 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
mbed_official 0:51ac1d130fd4 9 * All rights reserved.
mbed_official 0:51ac1d130fd4 10 *
mbed_official 0:51ac1d130fd4 11 * Redistribution and use in source and binary forms, with or without modification,
mbed_official 0:51ac1d130fd4 12 * are permitted provided that the following conditions are met:
mbed_official 0:51ac1d130fd4 13 *
mbed_official 0:51ac1d130fd4 14 * 1. Redistributions of source code must retain the above copyright notice,
mbed_official 0:51ac1d130fd4 15 * this list of conditions and the following disclaimer.
mbed_official 0:51ac1d130fd4 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
mbed_official 0:51ac1d130fd4 17 * this list of conditions and the following disclaimer in the documentation
mbed_official 0:51ac1d130fd4 18 * and/or other materials provided with the distribution.
mbed_official 0:51ac1d130fd4 19 * 3. The name of the author may not be used to endorse or promote products
mbed_official 0:51ac1d130fd4 20 * derived from this software without specific prior written permission.
mbed_official 0:51ac1d130fd4 21 *
mbed_official 0:51ac1d130fd4 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
mbed_official 0:51ac1d130fd4 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
mbed_official 0:51ac1d130fd4 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
mbed_official 0:51ac1d130fd4 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
mbed_official 0:51ac1d130fd4 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
mbed_official 0:51ac1d130fd4 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mbed_official 0:51ac1d130fd4 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
mbed_official 0:51ac1d130fd4 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
mbed_official 0:51ac1d130fd4 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
mbed_official 0:51ac1d130fd4 31 * OF SUCH DAMAGE.
mbed_official 0:51ac1d130fd4 32 *
mbed_official 0:51ac1d130fd4 33 * This file is part of the lwIP TCP/IP stack.
mbed_official 0:51ac1d130fd4 34 *
mbed_official 0:51ac1d130fd4 35 * Author: Adam Dunkels <adam@sics.se>
mbed_official 0:51ac1d130fd4 36 *
mbed_official 0:51ac1d130fd4 37 */
mbed_official 0:51ac1d130fd4 38
mbed_official 0:51ac1d130fd4 39 #include "lwip/opt.h"
mbed_official 0:51ac1d130fd4 40 #include "lwip/ip_addr.h"
mbed_official 0:51ac1d130fd4 41 #include "lwip/netif.h"
mbed_official 0:51ac1d130fd4 42
mbed_official 0:51ac1d130fd4 43 /* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
mbed_official 0:51ac1d130fd4 44 const ip_addr_t ip_addr_any = { IPADDR_ANY };
mbed_official 0:51ac1d130fd4 45 const ip_addr_t ip_addr_broadcast = { IPADDR_BROADCAST };
mbed_official 0:51ac1d130fd4 46
mbed_official 0:51ac1d130fd4 47 /**
mbed_official 0:51ac1d130fd4 48 * Determine if an address is a broadcast address on a network interface
mbed_official 0:51ac1d130fd4 49 *
mbed_official 0:51ac1d130fd4 50 * @param addr address to be checked
mbed_official 0:51ac1d130fd4 51 * @param netif the network interface against which the address is checked
mbed_official 0:51ac1d130fd4 52 * @return returns non-zero if the address is a broadcast address
mbed_official 0:51ac1d130fd4 53 */
mbed_official 0:51ac1d130fd4 54 u8_t
mbed_official 0:51ac1d130fd4 55 ip4_addr_isbroadcast(u32_t addr, const struct netif *netif)
mbed_official 0:51ac1d130fd4 56 {
mbed_official 0:51ac1d130fd4 57 ip_addr_t ipaddr;
mbed_official 0:51ac1d130fd4 58 ip4_addr_set_u32(&ipaddr, addr);
mbed_official 0:51ac1d130fd4 59
mbed_official 0:51ac1d130fd4 60 /* all ones (broadcast) or all zeroes (old skool broadcast) */
mbed_official 0:51ac1d130fd4 61 if ((~addr == IPADDR_ANY) ||
mbed_official 0:51ac1d130fd4 62 (addr == IPADDR_ANY)) {
mbed_official 0:51ac1d130fd4 63 return 1;
mbed_official 0:51ac1d130fd4 64 /* no broadcast support on this network interface? */
mbed_official 0:51ac1d130fd4 65 } else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) {
mbed_official 0:51ac1d130fd4 66 /* the given address cannot be a broadcast address
mbed_official 0:51ac1d130fd4 67 * nor can we check against any broadcast addresses */
mbed_official 0:51ac1d130fd4 68 return 0;
mbed_official 0:51ac1d130fd4 69 /* address matches network interface address exactly? => no broadcast */
mbed_official 0:51ac1d130fd4 70 } else if (addr == ip4_addr_get_u32(&netif->ip_addr)) {
mbed_official 0:51ac1d130fd4 71 return 0;
mbed_official 0:51ac1d130fd4 72 /* on the same (sub) network... */
mbed_official 0:51ac1d130fd4 73 } else if (ip_addr_netcmp(&ipaddr, &(netif->ip_addr), &(netif->netmask))
mbed_official 0:51ac1d130fd4 74 /* ...and host identifier bits are all ones? =>... */
mbed_official 0:51ac1d130fd4 75 && ((addr & ~ip4_addr_get_u32(&netif->netmask)) ==
mbed_official 0:51ac1d130fd4 76 (IPADDR_BROADCAST & ~ip4_addr_get_u32(&netif->netmask)))) {
mbed_official 0:51ac1d130fd4 77 /* => network broadcast address */
mbed_official 0:51ac1d130fd4 78 return 1;
mbed_official 0:51ac1d130fd4 79 } else {
mbed_official 0:51ac1d130fd4 80 return 0;
mbed_official 0:51ac1d130fd4 81 }
mbed_official 0:51ac1d130fd4 82 }
mbed_official 0:51ac1d130fd4 83
mbed_official 0:51ac1d130fd4 84 /** Checks if a netmask is valid (starting with ones, then only zeros)
mbed_official 0:51ac1d130fd4 85 *
mbed_official 0:51ac1d130fd4 86 * @param netmask the IPv4 netmask to check (in network byte order!)
mbed_official 0:51ac1d130fd4 87 * @return 1 if the netmask is valid, 0 if it is not
mbed_official 0:51ac1d130fd4 88 */
mbed_official 0:51ac1d130fd4 89 u8_t
mbed_official 0:51ac1d130fd4 90 ip4_addr_netmask_valid(u32_t netmask)
mbed_official 0:51ac1d130fd4 91 {
mbed_official 0:51ac1d130fd4 92 u32_t mask;
mbed_official 0:51ac1d130fd4 93 u32_t nm_hostorder = lwip_htonl(netmask);
mbed_official 0:51ac1d130fd4 94
mbed_official 0:51ac1d130fd4 95 /* first, check for the first zero */
mbed_official 0:51ac1d130fd4 96 for (mask = 1UL << 31 ; mask != 0; mask >>= 1) {
mbed_official 0:51ac1d130fd4 97 if ((nm_hostorder & mask) == 0) {
mbed_official 0:51ac1d130fd4 98 break;
mbed_official 0:51ac1d130fd4 99 }
mbed_official 0:51ac1d130fd4 100 }
mbed_official 0:51ac1d130fd4 101 /* then check that there is no one */
mbed_official 0:51ac1d130fd4 102 for (; mask != 0; mask >>= 1) {
mbed_official 0:51ac1d130fd4 103 if ((nm_hostorder & mask) != 0) {
mbed_official 0:51ac1d130fd4 104 /* there is a one after the first zero -> invalid */
mbed_official 0:51ac1d130fd4 105 return 0;
mbed_official 0:51ac1d130fd4 106 }
mbed_official 0:51ac1d130fd4 107 }
mbed_official 0:51ac1d130fd4 108 /* no one after the first zero -> valid */
mbed_official 0:51ac1d130fd4 109 return 1;
mbed_official 0:51ac1d130fd4 110 }
mbed_official 0:51ac1d130fd4 111
mbed_official 0:51ac1d130fd4 112 /* Here for now until needed in other places in lwIP */
mbed_official 0:51ac1d130fd4 113 #ifndef isprint
mbed_official 0:51ac1d130fd4 114 #define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up)
mbed_official 0:51ac1d130fd4 115 #define isprint(c) in_range(c, 0x20, 0x7f)
mbed_official 0:51ac1d130fd4 116 #define isdigit(c) in_range(c, '0', '9')
mbed_official 0:51ac1d130fd4 117 #define isxdigit(c) (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F'))
mbed_official 0:51ac1d130fd4 118 #define islower(c) in_range(c, 'a', 'z')
mbed_official 0:51ac1d130fd4 119 #define isspace(c) (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
mbed_official 0:51ac1d130fd4 120 #endif
mbed_official 0:51ac1d130fd4 121
mbed_official 0:51ac1d130fd4 122 /**
mbed_official 0:51ac1d130fd4 123 * Ascii internet address interpretation routine.
mbed_official 0:51ac1d130fd4 124 * The value returned is in network order.
mbed_official 0:51ac1d130fd4 125 *
mbed_official 0:51ac1d130fd4 126 * @param cp IP address in ascii represenation (e.g. "127.0.0.1")
mbed_official 0:51ac1d130fd4 127 * @return ip address in network order
mbed_official 0:51ac1d130fd4 128 */
mbed_official 0:51ac1d130fd4 129 u32_t
mbed_official 0:51ac1d130fd4 130 ipaddr_addr(const char *cp)
mbed_official 0:51ac1d130fd4 131 {
mbed_official 0:51ac1d130fd4 132 ip_addr_t val;
mbed_official 0:51ac1d130fd4 133
mbed_official 0:51ac1d130fd4 134 if (ipaddr_aton(cp, &val)) {
mbed_official 0:51ac1d130fd4 135 return ip4_addr_get_u32(&val);
mbed_official 0:51ac1d130fd4 136 }
mbed_official 0:51ac1d130fd4 137 return (IPADDR_NONE);
mbed_official 0:51ac1d130fd4 138 }
mbed_official 0:51ac1d130fd4 139
mbed_official 0:51ac1d130fd4 140 /**
mbed_official 0:51ac1d130fd4 141 * Check whether "cp" is a valid ascii representation
mbed_official 0:51ac1d130fd4 142 * of an Internet address and convert to a binary address.
mbed_official 0:51ac1d130fd4 143 * Returns 1 if the address is valid, 0 if not.
mbed_official 0:51ac1d130fd4 144 * This replaces inet_addr, the return value from which
mbed_official 0:51ac1d130fd4 145 * cannot distinguish between failure and a local broadcast address.
mbed_official 0:51ac1d130fd4 146 *
mbed_official 0:51ac1d130fd4 147 * @param cp IP address in ascii represenation (e.g. "127.0.0.1")
mbed_official 0:51ac1d130fd4 148 * @param addr pointer to which to save the ip address in network order
mbed_official 0:51ac1d130fd4 149 * @return 1 if cp could be converted to addr, 0 on failure
mbed_official 0:51ac1d130fd4 150 */
mbed_official 0:51ac1d130fd4 151 int
mbed_official 0:51ac1d130fd4 152 ipaddr_aton(const char *cp, ip_addr_t *addr)
mbed_official 0:51ac1d130fd4 153 {
mbed_official 0:51ac1d130fd4 154 u32_t val;
mbed_official 0:51ac1d130fd4 155 u8_t base;
mbed_official 0:51ac1d130fd4 156 char c;
mbed_official 0:51ac1d130fd4 157 u32_t parts[4];
mbed_official 0:51ac1d130fd4 158 u32_t *pp = parts;
mbed_official 0:51ac1d130fd4 159
mbed_official 0:51ac1d130fd4 160 c = *cp;
mbed_official 0:51ac1d130fd4 161 for (;;) {
mbed_official 0:51ac1d130fd4 162 /*
mbed_official 0:51ac1d130fd4 163 * Collect number up to ``.''.
mbed_official 0:51ac1d130fd4 164 * Values are specified as for C:
mbed_official 0:51ac1d130fd4 165 * 0x=hex, 0=octal, 1-9=decimal.
mbed_official 0:51ac1d130fd4 166 */
mbed_official 0:51ac1d130fd4 167 if (!isdigit(c))
mbed_official 0:51ac1d130fd4 168 return (0);
mbed_official 0:51ac1d130fd4 169 val = 0;
mbed_official 0:51ac1d130fd4 170 base = 10;
mbed_official 0:51ac1d130fd4 171 if (c == '0') {
mbed_official 0:51ac1d130fd4 172 c = *++cp;
mbed_official 0:51ac1d130fd4 173 if (c == 'x' || c == 'X') {
mbed_official 0:51ac1d130fd4 174 base = 16;
mbed_official 0:51ac1d130fd4 175 c = *++cp;
mbed_official 0:51ac1d130fd4 176 } else
mbed_official 0:51ac1d130fd4 177 base = 8;
mbed_official 0:51ac1d130fd4 178 }
mbed_official 0:51ac1d130fd4 179 for (;;) {
mbed_official 0:51ac1d130fd4 180 if (isdigit(c)) {
mbed_official 0:51ac1d130fd4 181 val = (val * base) + (int)(c - '0');
mbed_official 0:51ac1d130fd4 182 c = *++cp;
mbed_official 0:51ac1d130fd4 183 } else if (base == 16 && isxdigit(c)) {
mbed_official 0:51ac1d130fd4 184 val = (val << 4) | (int)(c + 10 - (islower(c) ? 'a' : 'A'));
mbed_official 0:51ac1d130fd4 185 c = *++cp;
mbed_official 0:51ac1d130fd4 186 } else
mbed_official 0:51ac1d130fd4 187 break;
mbed_official 0:51ac1d130fd4 188 }
mbed_official 0:51ac1d130fd4 189 if (c == '.') {
mbed_official 0:51ac1d130fd4 190 /*
mbed_official 0:51ac1d130fd4 191 * Internet format:
mbed_official 0:51ac1d130fd4 192 * a.b.c.d
mbed_official 0:51ac1d130fd4 193 * a.b.c (with c treated as 16 bits)
mbed_official 0:51ac1d130fd4 194 * a.b (with b treated as 24 bits)
mbed_official 0:51ac1d130fd4 195 */
mbed_official 0:51ac1d130fd4 196 if (pp >= parts + 3) {
mbed_official 0:51ac1d130fd4 197 return (0);
mbed_official 0:51ac1d130fd4 198 }
mbed_official 0:51ac1d130fd4 199 *pp++ = val;
mbed_official 0:51ac1d130fd4 200 c = *++cp;
mbed_official 0:51ac1d130fd4 201 } else
mbed_official 0:51ac1d130fd4 202 break;
mbed_official 0:51ac1d130fd4 203 }
mbed_official 0:51ac1d130fd4 204 /*
mbed_official 0:51ac1d130fd4 205 * Check for trailing characters.
mbed_official 0:51ac1d130fd4 206 */
mbed_official 0:51ac1d130fd4 207 if (c != '\0' && !isspace(c)) {
mbed_official 0:51ac1d130fd4 208 return (0);
mbed_official 0:51ac1d130fd4 209 }
mbed_official 0:51ac1d130fd4 210 /*
mbed_official 0:51ac1d130fd4 211 * Concoct the address according to
mbed_official 0:51ac1d130fd4 212 * the number of parts specified.
mbed_official 0:51ac1d130fd4 213 */
mbed_official 0:51ac1d130fd4 214 switch (pp - parts + 1) {
mbed_official 0:51ac1d130fd4 215
mbed_official 0:51ac1d130fd4 216 case 0:
mbed_official 0:51ac1d130fd4 217 return (0); /* initial nondigit */
mbed_official 0:51ac1d130fd4 218
mbed_official 0:51ac1d130fd4 219 case 1: /* a -- 32 bits */
mbed_official 0:51ac1d130fd4 220 break;
mbed_official 0:51ac1d130fd4 221
mbed_official 0:51ac1d130fd4 222 case 2: /* a.b -- 8.24 bits */
mbed_official 0:51ac1d130fd4 223 if (val > 0xffffffUL) {
mbed_official 0:51ac1d130fd4 224 return (0);
mbed_official 0:51ac1d130fd4 225 }
mbed_official 0:51ac1d130fd4 226 val |= parts[0] << 24;
mbed_official 0:51ac1d130fd4 227 break;
mbed_official 0:51ac1d130fd4 228
mbed_official 0:51ac1d130fd4 229 case 3: /* a.b.c -- 8.8.16 bits */
mbed_official 0:51ac1d130fd4 230 if (val > 0xffff) {
mbed_official 0:51ac1d130fd4 231 return (0);
mbed_official 0:51ac1d130fd4 232 }
mbed_official 0:51ac1d130fd4 233 val |= (parts[0] << 24) | (parts[1] << 16);
mbed_official 0:51ac1d130fd4 234 break;
mbed_official 0:51ac1d130fd4 235
mbed_official 0:51ac1d130fd4 236 case 4: /* a.b.c.d -- 8.8.8.8 bits */
mbed_official 0:51ac1d130fd4 237 if (val > 0xff) {
mbed_official 0:51ac1d130fd4 238 return (0);
mbed_official 0:51ac1d130fd4 239 }
mbed_official 0:51ac1d130fd4 240 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
mbed_official 0:51ac1d130fd4 241 break;
mbed_official 0:51ac1d130fd4 242 default:
mbed_official 0:51ac1d130fd4 243 LWIP_ASSERT("unhandled", 0);
mbed_official 0:51ac1d130fd4 244 break;
mbed_official 0:51ac1d130fd4 245 }
mbed_official 0:51ac1d130fd4 246 if (addr) {
mbed_official 0:51ac1d130fd4 247 ip4_addr_set_u32(addr, htonl(val));
mbed_official 0:51ac1d130fd4 248 }
mbed_official 0:51ac1d130fd4 249 return (1);
mbed_official 0:51ac1d130fd4 250 }
mbed_official 0:51ac1d130fd4 251
mbed_official 0:51ac1d130fd4 252 /**
mbed_official 0:51ac1d130fd4 253 * Convert numeric IP address into decimal dotted ASCII representation.
mbed_official 0:51ac1d130fd4 254 * returns ptr to static buffer; not reentrant!
mbed_official 0:51ac1d130fd4 255 *
mbed_official 0:51ac1d130fd4 256 * @param addr ip address in network order to convert
mbed_official 0:51ac1d130fd4 257 * @return pointer to a global static (!) buffer that holds the ASCII
mbed_official 0:51ac1d130fd4 258 * represenation of addr
mbed_official 0:51ac1d130fd4 259 */
mbed_official 0:51ac1d130fd4 260 char *
mbed_official 0:51ac1d130fd4 261 ipaddr_ntoa(const ip_addr_t *addr)
mbed_official 0:51ac1d130fd4 262 {
mbed_official 0:51ac1d130fd4 263 static char str[16];
mbed_official 0:51ac1d130fd4 264 return ipaddr_ntoa_r(addr, str, 16);
mbed_official 0:51ac1d130fd4 265 }
mbed_official 0:51ac1d130fd4 266
mbed_official 0:51ac1d130fd4 267 /**
mbed_official 0:51ac1d130fd4 268 * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
mbed_official 0:51ac1d130fd4 269 *
mbed_official 0:51ac1d130fd4 270 * @param addr ip address in network order to convert
mbed_official 0:51ac1d130fd4 271 * @param buf target buffer where the string is stored
mbed_official 0:51ac1d130fd4 272 * @param buflen length of buf
mbed_official 0:51ac1d130fd4 273 * @return either pointer to buf which now holds the ASCII
mbed_official 0:51ac1d130fd4 274 * representation of addr or NULL if buf was too small
mbed_official 0:51ac1d130fd4 275 */
mbed_official 0:51ac1d130fd4 276 char *ipaddr_ntoa_r(const ip_addr_t *addr, char *buf, int buflen)
mbed_official 0:51ac1d130fd4 277 {
mbed_official 0:51ac1d130fd4 278 u32_t s_addr;
mbed_official 0:51ac1d130fd4 279 char inv[3];
mbed_official 0:51ac1d130fd4 280 char *rp;
mbed_official 0:51ac1d130fd4 281 u8_t *ap;
mbed_official 0:51ac1d130fd4 282 u8_t rem;
mbed_official 0:51ac1d130fd4 283 u8_t n;
mbed_official 0:51ac1d130fd4 284 u8_t i;
mbed_official 0:51ac1d130fd4 285 int len = 0;
mbed_official 0:51ac1d130fd4 286
mbed_official 0:51ac1d130fd4 287 s_addr = ip4_addr_get_u32(addr);
mbed_official 0:51ac1d130fd4 288
mbed_official 0:51ac1d130fd4 289 rp = buf;
mbed_official 0:51ac1d130fd4 290 ap = (u8_t *)&s_addr;
mbed_official 0:51ac1d130fd4 291 for(n = 0; n < 4; n++) {
mbed_official 0:51ac1d130fd4 292 i = 0;
mbed_official 0:51ac1d130fd4 293 do {
mbed_official 0:51ac1d130fd4 294 rem = *ap % (u8_t)10;
mbed_official 0:51ac1d130fd4 295 *ap /= (u8_t)10;
mbed_official 0:51ac1d130fd4 296 inv[i++] = '0' + rem;
mbed_official 0:51ac1d130fd4 297 } while(*ap);
mbed_official 0:51ac1d130fd4 298 while(i--) {
mbed_official 0:51ac1d130fd4 299 if (len++ >= buflen) {
mbed_official 0:51ac1d130fd4 300 return NULL;
mbed_official 0:51ac1d130fd4 301 }
mbed_official 0:51ac1d130fd4 302 *rp++ = inv[i];
mbed_official 0:51ac1d130fd4 303 }
mbed_official 0:51ac1d130fd4 304 if (len++ >= buflen) {
mbed_official 0:51ac1d130fd4 305 return NULL;
mbed_official 0:51ac1d130fd4 306 }
mbed_official 0:51ac1d130fd4 307 *rp++ = '.';
mbed_official 0:51ac1d130fd4 308 ap++;
mbed_official 0:51ac1d130fd4 309 }
mbed_official 0:51ac1d130fd4 310 *--rp = 0;
mbed_official 0:51ac1d130fd4 311 return buf;
mbed_official 0:51ac1d130fd4 312 }