Lorcan Smith / Mbed 2 deprecated Enet_SPI

SNMP agent attached to SPI slave

Dependencies:   mbed

lwip/core/ipv4/ip_addr.c@0:2a53a4c3238c, 2012-08-13 (annotated)

Committer:
lorcansmith
Date:
Mon Aug 13 15:07:40 2012 +0000
Revision:
0:2a53a4c3238c
v1.1 release includes ioAlarm traps

Who changed what in which revision?

UserRevisionLine numberNew contents of line
lorcansmith 0:2a53a4c3238c 1 /**
lorcansmith 0:2a53a4c3238c 2 * @file
lorcansmith 0:2a53a4c3238c 3 * This is the IPv4 address tools implementation.
lorcansmith 0:2a53a4c3238c 4 *
lorcansmith 0:2a53a4c3238c 5 */
lorcansmith 0:2a53a4c3238c 6
lorcansmith 0:2a53a4c3238c 7 /*
lorcansmith 0:2a53a4c3238c 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
lorcansmith 0:2a53a4c3238c 9 * All rights reserved.
lorcansmith 0:2a53a4c3238c 10 *
lorcansmith 0:2a53a4c3238c 11 * Redistribution and use in source and binary forms, with or without modification,
lorcansmith 0:2a53a4c3238c 12 * are permitted provided that the following conditions are met:
lorcansmith 0:2a53a4c3238c 13 *
lorcansmith 0:2a53a4c3238c 14 * 1. Redistributions of source code must retain the above copyright notice,
lorcansmith 0:2a53a4c3238c 15 * this list of conditions and the following disclaimer.
lorcansmith 0:2a53a4c3238c 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
lorcansmith 0:2a53a4c3238c 17 * this list of conditions and the following disclaimer in the documentation
lorcansmith 0:2a53a4c3238c 18 * and/or other materials provided with the distribution.
lorcansmith 0:2a53a4c3238c 19 * 3. The name of the author may not be used to endorse or promote products
lorcansmith 0:2a53a4c3238c 20 * derived from this software without specific prior written permission.
lorcansmith 0:2a53a4c3238c 21 *
lorcansmith 0:2a53a4c3238c 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
lorcansmith 0:2a53a4c3238c 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
lorcansmith 0:2a53a4c3238c 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
lorcansmith 0:2a53a4c3238c 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
lorcansmith 0:2a53a4c3238c 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
lorcansmith 0:2a53a4c3238c 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
lorcansmith 0:2a53a4c3238c 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
lorcansmith 0:2a53a4c3238c 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
lorcansmith 0:2a53a4c3238c 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
lorcansmith 0:2a53a4c3238c 31 * OF SUCH DAMAGE.
lorcansmith 0:2a53a4c3238c 32 *
lorcansmith 0:2a53a4c3238c 33 * This file is part of the lwIP TCP/IP stack.
lorcansmith 0:2a53a4c3238c 34 *
lorcansmith 0:2a53a4c3238c 35 * Author: Adam Dunkels <adam@sics.se>
lorcansmith 0:2a53a4c3238c 36 *
lorcansmith 0:2a53a4c3238c 37 */
lorcansmith 0:2a53a4c3238c 38
lorcansmith 0:2a53a4c3238c 39 #include "lwip/opt.h"
lorcansmith 0:2a53a4c3238c 40 #include "lwip/ip_addr.h"
lorcansmith 0:2a53a4c3238c 41 #include "lwip/netif.h"
lorcansmith 0:2a53a4c3238c 42
lorcansmith 0:2a53a4c3238c 43 /* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
lorcansmith 0:2a53a4c3238c 44 const ip_addr_t ip_addr_any = { IPADDR_ANY };
lorcansmith 0:2a53a4c3238c 45 const ip_addr_t ip_addr_broadcast = { IPADDR_BROADCAST };
lorcansmith 0:2a53a4c3238c 46
lorcansmith 0:2a53a4c3238c 47 /**
lorcansmith 0:2a53a4c3238c 48 * Determine if an address is a broadcast address on a network interface
lorcansmith 0:2a53a4c3238c 49 *
lorcansmith 0:2a53a4c3238c 50 * @param addr address to be checked
lorcansmith 0:2a53a4c3238c 51 * @param netif the network interface against which the address is checked
lorcansmith 0:2a53a4c3238c 52 * @return returns non-zero if the address is a broadcast address
lorcansmith 0:2a53a4c3238c 53 */
lorcansmith 0:2a53a4c3238c 54 u8_t
lorcansmith 0:2a53a4c3238c 55 ip4_addr_isbroadcast(u32_t addr, const struct netif *netif)
lorcansmith 0:2a53a4c3238c 56 {
lorcansmith 0:2a53a4c3238c 57 ip_addr_t ipaddr;
lorcansmith 0:2a53a4c3238c 58 ip4_addr_set_u32(&ipaddr, addr);
lorcansmith 0:2a53a4c3238c 59
lorcansmith 0:2a53a4c3238c 60 /* all ones (broadcast) or all zeroes (old skool broadcast) */
lorcansmith 0:2a53a4c3238c 61 if ((~addr == IPADDR_ANY) ||
lorcansmith 0:2a53a4c3238c 62 (addr == IPADDR_ANY)) {
lorcansmith 0:2a53a4c3238c 63 return 1;
lorcansmith 0:2a53a4c3238c 64 /* no broadcast support on this network interface? */
lorcansmith 0:2a53a4c3238c 65 } else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) {
lorcansmith 0:2a53a4c3238c 66 /* the given address cannot be a broadcast address
lorcansmith 0:2a53a4c3238c 67 * nor can we check against any broadcast addresses */
lorcansmith 0:2a53a4c3238c 68 return 0;
lorcansmith 0:2a53a4c3238c 69 /* address matches network interface address exactly? => no broadcast */
lorcansmith 0:2a53a4c3238c 70 } else if (addr == ip4_addr_get_u32(&netif->ip_addr)) {
lorcansmith 0:2a53a4c3238c 71 return 0;
lorcansmith 0:2a53a4c3238c 72 /* on the same (sub) network... */
lorcansmith 0:2a53a4c3238c 73 } else if (ip_addr_netcmp(&ipaddr, &(netif->ip_addr), &(netif->netmask))
lorcansmith 0:2a53a4c3238c 74 /* ...and host identifier bits are all ones? =>... */
lorcansmith 0:2a53a4c3238c 75 && ((addr & ~ip4_addr_get_u32(&netif->netmask)) ==
lorcansmith 0:2a53a4c3238c 76 (IPADDR_BROADCAST & ~ip4_addr_get_u32(&netif->netmask)))) {
lorcansmith 0:2a53a4c3238c 77 /* => network broadcast address */
lorcansmith 0:2a53a4c3238c 78 return 1;
lorcansmith 0:2a53a4c3238c 79 } else {
lorcansmith 0:2a53a4c3238c 80 return 0;
lorcansmith 0:2a53a4c3238c 81 }
lorcansmith 0:2a53a4c3238c 82 }
lorcansmith 0:2a53a4c3238c 83
lorcansmith 0:2a53a4c3238c 84 /** Checks if a netmask is valid (starting with ones, then only zeros)
lorcansmith 0:2a53a4c3238c 85 *
lorcansmith 0:2a53a4c3238c 86 * @param netmask the IPv4 netmask to check (in network byte order!)
lorcansmith 0:2a53a4c3238c 87 * @return 1 if the netmask is valid, 0 if it is not
lorcansmith 0:2a53a4c3238c 88 */
lorcansmith 0:2a53a4c3238c 89 u8_t
lorcansmith 0:2a53a4c3238c 90 ip4_addr_netmask_valid(u32_t netmask)
lorcansmith 0:2a53a4c3238c 91 {
lorcansmith 0:2a53a4c3238c 92 u32_t mask;
lorcansmith 0:2a53a4c3238c 93 u32_t nm_hostorder = lwip_htonl(netmask);
lorcansmith 0:2a53a4c3238c 94
lorcansmith 0:2a53a4c3238c 95 /* first, check for the first zero */
lorcansmith 0:2a53a4c3238c 96 for (mask = 1U << 31 ; mask != 0; mask >>= 1) {
lorcansmith 0:2a53a4c3238c 97 if ((nm_hostorder & mask) == 0) {
lorcansmith 0:2a53a4c3238c 98 break;
lorcansmith 0:2a53a4c3238c 99 }
lorcansmith 0:2a53a4c3238c 100 }
lorcansmith 0:2a53a4c3238c 101 /* then check that there is no one */
lorcansmith 0:2a53a4c3238c 102 for (; mask != 0; mask >>= 1) {
lorcansmith 0:2a53a4c3238c 103 if ((nm_hostorder & mask) != 0) {
lorcansmith 0:2a53a4c3238c 104 /* there is a one after the first zero -> invalid */
lorcansmith 0:2a53a4c3238c 105 return 0;
lorcansmith 0:2a53a4c3238c 106 }
lorcansmith 0:2a53a4c3238c 107 }
lorcansmith 0:2a53a4c3238c 108 /* no one after the first zero -> valid */
lorcansmith 0:2a53a4c3238c 109 return 1;
lorcansmith 0:2a53a4c3238c 110 }
lorcansmith 0:2a53a4c3238c 111
lorcansmith 0:2a53a4c3238c 112 /* Here for now until needed in other places in lwIP */
lorcansmith 0:2a53a4c3238c 113 #ifndef isprint
lorcansmith 0:2a53a4c3238c 114 #define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up)
lorcansmith 0:2a53a4c3238c 115 #define isprint(c) in_range(c, 0x20, 0x7f)
lorcansmith 0:2a53a4c3238c 116 #define isdigit(c) in_range(c, '0', '9')
lorcansmith 0:2a53a4c3238c 117 #define isxdigit(c) (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F'))
lorcansmith 0:2a53a4c3238c 118 #define islower(c) in_range(c, 'a', 'z')
lorcansmith 0:2a53a4c3238c 119 #define isspace(c) (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
lorcansmith 0:2a53a4c3238c 120 #endif
lorcansmith 0:2a53a4c3238c 121
lorcansmith 0:2a53a4c3238c 122 /**
lorcansmith 0:2a53a4c3238c 123 * Ascii internet address interpretation routine.
lorcansmith 0:2a53a4c3238c 124 * The value returned is in network order.
lorcansmith 0:2a53a4c3238c 125 *
lorcansmith 0:2a53a4c3238c 126 * @param cp IP address in ascii represenation (e.g. "127.0.0.1")
lorcansmith 0:2a53a4c3238c 127 * @return ip address in network order
lorcansmith 0:2a53a4c3238c 128 */
lorcansmith 0:2a53a4c3238c 129 u32_t
lorcansmith 0:2a53a4c3238c 130 ipaddr_addr(const char *cp)
lorcansmith 0:2a53a4c3238c 131 {
lorcansmith 0:2a53a4c3238c 132 ip_addr_t val;
lorcansmith 0:2a53a4c3238c 133
lorcansmith 0:2a53a4c3238c 134 if (ipaddr_aton(cp, &val)) {
lorcansmith 0:2a53a4c3238c 135 return ip4_addr_get_u32(&val);
lorcansmith 0:2a53a4c3238c 136 }
lorcansmith 0:2a53a4c3238c 137 return (IPADDR_NONE);
lorcansmith 0:2a53a4c3238c 138 }
lorcansmith 0:2a53a4c3238c 139
lorcansmith 0:2a53a4c3238c 140 /**
lorcansmith 0:2a53a4c3238c 141 * Check whether "cp" is a valid ascii representation
lorcansmith 0:2a53a4c3238c 142 * of an Internet address and convert to a binary address.
lorcansmith 0:2a53a4c3238c 143 * Returns 1 if the address is valid, 0 if not.
lorcansmith 0:2a53a4c3238c 144 * This replaces inet_addr, the return value from which
lorcansmith 0:2a53a4c3238c 145 * cannot distinguish between failure and a local broadcast address.
lorcansmith 0:2a53a4c3238c 146 *
lorcansmith 0:2a53a4c3238c 147 * @param cp IP address in ascii represenation (e.g. "127.0.0.1")
lorcansmith 0:2a53a4c3238c 148 * @param addr pointer to which to save the ip address in network order
lorcansmith 0:2a53a4c3238c 149 * @return 1 if cp could be converted to addr, 0 on failure
lorcansmith 0:2a53a4c3238c 150 */
lorcansmith 0:2a53a4c3238c 151 int
lorcansmith 0:2a53a4c3238c 152 ipaddr_aton(const char *cp, ip_addr_t *addr)
lorcansmith 0:2a53a4c3238c 153 {
lorcansmith 0:2a53a4c3238c 154 u32_t val;
lorcansmith 0:2a53a4c3238c 155 u8_t base;
lorcansmith 0:2a53a4c3238c 156 char c;
lorcansmith 0:2a53a4c3238c 157 u32_t parts[4];
lorcansmith 0:2a53a4c3238c 158 u32_t *pp = parts;
lorcansmith 0:2a53a4c3238c 159
lorcansmith 0:2a53a4c3238c 160 c = *cp;
lorcansmith 0:2a53a4c3238c 161 for (;;) {
lorcansmith 0:2a53a4c3238c 162 /*
lorcansmith 0:2a53a4c3238c 163 * Collect number up to ``.''.
lorcansmith 0:2a53a4c3238c 164 * Values are specified as for C:
lorcansmith 0:2a53a4c3238c 165 * 0x=hex, 0=octal, 1-9=decimal.
lorcansmith 0:2a53a4c3238c 166 */
lorcansmith 0:2a53a4c3238c 167 if (!isdigit(c))
lorcansmith 0:2a53a4c3238c 168 return (0);
lorcansmith 0:2a53a4c3238c 169 val = 0;
lorcansmith 0:2a53a4c3238c 170 base = 10;
lorcansmith 0:2a53a4c3238c 171 if (c == '0') {
lorcansmith 0:2a53a4c3238c 172 c = *++cp;
lorcansmith 0:2a53a4c3238c 173 if (c == 'x' || c == 'X') {
lorcansmith 0:2a53a4c3238c 174 base = 16;
lorcansmith 0:2a53a4c3238c 175 c = *++cp;
lorcansmith 0:2a53a4c3238c 176 } else
lorcansmith 0:2a53a4c3238c 177 base = 8;
lorcansmith 0:2a53a4c3238c 178 }
lorcansmith 0:2a53a4c3238c 179 for (;;) {
lorcansmith 0:2a53a4c3238c 180 if (isdigit(c)) {
lorcansmith 0:2a53a4c3238c 181 val = (val * base) + (int)(c - '0');
lorcansmith 0:2a53a4c3238c 182 c = *++cp;
lorcansmith 0:2a53a4c3238c 183 } else if (base == 16 && isxdigit(c)) {
lorcansmith 0:2a53a4c3238c 184 val = (val << 4) | (int)(c + 10 - (islower(c) ? 'a' : 'A'));
lorcansmith 0:2a53a4c3238c 185 c = *++cp;
lorcansmith 0:2a53a4c3238c 186 } else
lorcansmith 0:2a53a4c3238c 187 break;
lorcansmith 0:2a53a4c3238c 188 }
lorcansmith 0:2a53a4c3238c 189 if (c == '.') {
lorcansmith 0:2a53a4c3238c 190 /*
lorcansmith 0:2a53a4c3238c 191 * Internet format:
lorcansmith 0:2a53a4c3238c 192 * a.b.c.d
lorcansmith 0:2a53a4c3238c 193 * a.b.c (with c treated as 16 bits)
lorcansmith 0:2a53a4c3238c 194 * a.b (with b treated as 24 bits)
lorcansmith 0:2a53a4c3238c 195 */
lorcansmith 0:2a53a4c3238c 196 if (pp >= parts + 3) {
lorcansmith 0:2a53a4c3238c 197 return (0);
lorcansmith 0:2a53a4c3238c 198 }
lorcansmith 0:2a53a4c3238c 199 *pp++ = val;
lorcansmith 0:2a53a4c3238c 200 c = *++cp;
lorcansmith 0:2a53a4c3238c 201 } else
lorcansmith 0:2a53a4c3238c 202 break;
lorcansmith 0:2a53a4c3238c 203 }
lorcansmith 0:2a53a4c3238c 204 /*
lorcansmith 0:2a53a4c3238c 205 * Check for trailing characters.
lorcansmith 0:2a53a4c3238c 206 */
lorcansmith 0:2a53a4c3238c 207 if (c != '\0' && !isspace(c)) {
lorcansmith 0:2a53a4c3238c 208 return (0);
lorcansmith 0:2a53a4c3238c 209 }
lorcansmith 0:2a53a4c3238c 210 /*
lorcansmith 0:2a53a4c3238c 211 * Concoct the address according to
lorcansmith 0:2a53a4c3238c 212 * the number of parts specified.
lorcansmith 0:2a53a4c3238c 213 */
lorcansmith 0:2a53a4c3238c 214 switch (pp - parts + 1) {
lorcansmith 0:2a53a4c3238c 215
lorcansmith 0:2a53a4c3238c 216 case 0:
lorcansmith 0:2a53a4c3238c 217 return (0); /* initial nondigit */
lorcansmith 0:2a53a4c3238c 218
lorcansmith 0:2a53a4c3238c 219 case 1: /* a -- 32 bits */
lorcansmith 0:2a53a4c3238c 220 break;
lorcansmith 0:2a53a4c3238c 221
lorcansmith 0:2a53a4c3238c 222 case 2: /* a.b -- 8.24 bits */
lorcansmith 0:2a53a4c3238c 223 if (val > 0xffffffUL) {
lorcansmith 0:2a53a4c3238c 224 return (0);
lorcansmith 0:2a53a4c3238c 225 }
lorcansmith 0:2a53a4c3238c 226 val |= parts[0] << 24;
lorcansmith 0:2a53a4c3238c 227 break;
lorcansmith 0:2a53a4c3238c 228
lorcansmith 0:2a53a4c3238c 229 case 3: /* a.b.c -- 8.8.16 bits */
lorcansmith 0:2a53a4c3238c 230 if (val > 0xffff) {
lorcansmith 0:2a53a4c3238c 231 return (0);
lorcansmith 0:2a53a4c3238c 232 }
lorcansmith 0:2a53a4c3238c 233 val |= (parts[0] << 24) | (parts[1] << 16);
lorcansmith 0:2a53a4c3238c 234 break;
lorcansmith 0:2a53a4c3238c 235
lorcansmith 0:2a53a4c3238c 236 case 4: /* a.b.c.d -- 8.8.8.8 bits */
lorcansmith 0:2a53a4c3238c 237 if (val > 0xff) {
lorcansmith 0:2a53a4c3238c 238 return (0);
lorcansmith 0:2a53a4c3238c 239 }
lorcansmith 0:2a53a4c3238c 240 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
lorcansmith 0:2a53a4c3238c 241 break;
lorcansmith 0:2a53a4c3238c 242 default:
lorcansmith 0:2a53a4c3238c 243 LWIP_ASSERT("unhandled", 0);
lorcansmith 0:2a53a4c3238c 244 break;
lorcansmith 0:2a53a4c3238c 245 }
lorcansmith 0:2a53a4c3238c 246 if (addr) {
lorcansmith 0:2a53a4c3238c 247 ip4_addr_set_u32(addr, htonl(val));
lorcansmith 0:2a53a4c3238c 248 }
lorcansmith 0:2a53a4c3238c 249 return (1);
lorcansmith 0:2a53a4c3238c 250 }
lorcansmith 0:2a53a4c3238c 251
lorcansmith 0:2a53a4c3238c 252 /**
lorcansmith 0:2a53a4c3238c 253 * Convert numeric IP address into decimal dotted ASCII representation.
lorcansmith 0:2a53a4c3238c 254 * returns ptr to static buffer; not reentrant!
lorcansmith 0:2a53a4c3238c 255 *
lorcansmith 0:2a53a4c3238c 256 * @param addr ip address in network order to convert
lorcansmith 0:2a53a4c3238c 257 * @return pointer to a global static (!) buffer that holds the ASCII
lorcansmith 0:2a53a4c3238c 258 * represenation of addr
lorcansmith 0:2a53a4c3238c 259 */
lorcansmith 0:2a53a4c3238c 260 char *
lorcansmith 0:2a53a4c3238c 261 ipaddr_ntoa(const ip_addr_t *addr)
lorcansmith 0:2a53a4c3238c 262 {
lorcansmith 0:2a53a4c3238c 263 static char str[16];
lorcansmith 0:2a53a4c3238c 264 return ipaddr_ntoa_r(addr, str, 16);
lorcansmith 0:2a53a4c3238c 265 }
lorcansmith 0:2a53a4c3238c 266
lorcansmith 0:2a53a4c3238c 267 /**
lorcansmith 0:2a53a4c3238c 268 * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
lorcansmith 0:2a53a4c3238c 269 *
lorcansmith 0:2a53a4c3238c 270 * @param addr ip address in network order to convert
lorcansmith 0:2a53a4c3238c 271 * @param buf target buffer where the string is stored
lorcansmith 0:2a53a4c3238c 272 * @param buflen length of buf
lorcansmith 0:2a53a4c3238c 273 * @return either pointer to buf which now holds the ASCII
lorcansmith 0:2a53a4c3238c 274 * representation of addr or NULL if buf was too small
lorcansmith 0:2a53a4c3238c 275 */
lorcansmith 0:2a53a4c3238c 276 char *ipaddr_ntoa_r(const ip_addr_t *addr, char *buf, int buflen)
lorcansmith 0:2a53a4c3238c 277 {
lorcansmith 0:2a53a4c3238c 278 u32_t s_addr;
lorcansmith 0:2a53a4c3238c 279 char inv[3];
lorcansmith 0:2a53a4c3238c 280 char *rp;
lorcansmith 0:2a53a4c3238c 281 u8_t *ap;
lorcansmith 0:2a53a4c3238c 282 u8_t rem;
lorcansmith 0:2a53a4c3238c 283 u8_t n;
lorcansmith 0:2a53a4c3238c 284 u8_t i;
lorcansmith 0:2a53a4c3238c 285 int len = 0;
lorcansmith 0:2a53a4c3238c 286
lorcansmith 0:2a53a4c3238c 287 s_addr = ip4_addr_get_u32(addr);
lorcansmith 0:2a53a4c3238c 288
lorcansmith 0:2a53a4c3238c 289 rp = buf;
lorcansmith 0:2a53a4c3238c 290 ap = (u8_t *)&s_addr;
lorcansmith 0:2a53a4c3238c 291 for(n = 0; n < 4; n++) {
lorcansmith 0:2a53a4c3238c 292 i = 0;
lorcansmith 0:2a53a4c3238c 293 do {
lorcansmith 0:2a53a4c3238c 294 rem = *ap % (u8_t)10;
lorcansmith 0:2a53a4c3238c 295 *ap /= (u8_t)10;
lorcansmith 0:2a53a4c3238c 296 inv[i++] = '0' + rem;
lorcansmith 0:2a53a4c3238c 297 } while(*ap);
lorcansmith 0:2a53a4c3238c 298 while(i--) {
lorcansmith 0:2a53a4c3238c 299 if (len++ >= buflen) {
lorcansmith 0:2a53a4c3238c 300 return NULL;
lorcansmith 0:2a53a4c3238c 301 }
lorcansmith 0:2a53a4c3238c 302 *rp++ = inv[i];
lorcansmith 0:2a53a4c3238c 303 }
lorcansmith 0:2a53a4c3238c 304 if (len++ >= buflen) {
lorcansmith 0:2a53a4c3238c 305 return NULL;
lorcansmith 0:2a53a4c3238c 306 }
lorcansmith 0:2a53a4c3238c 307 *rp++ = '.';
lorcansmith 0:2a53a4c3238c 308 ap++;
lorcansmith 0:2a53a4c3238c 309 }
lorcansmith 0:2a53a4c3238c 310 *--rp = 0;
lorcansmith 0:2a53a4c3238c 311 return buf;
lorcansmith 0:2a53a4c3238c 312 }