David Smart / lwip

minor derivative to reduce compiler warnings and tag read-only parameters as const.

Dependents:   EthernetInterface

Fork of lwip by mbed official

core/ipv4/ip_addr.c@21:d78ed585db09, 2018-06-10 (annotated)

Committer:
WiredHome
Date:
Sun Jun 10 22:17:20 2018 +0000
Revision:
21:d78ed585db09
Parent:
0:51ac1d130fd4 
revise some error returns for unique < 0 numbers

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 }