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 <[email protected]>
36 *
37 */
38
39 #include "lwip/opt.h"
40
41 #if LWIP_IPV4
42
43 #include "lwip/ip_addr.h"
44 #include "lwip/netif.h"
45
46 /* used by IP4_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
47 const ip_addr_t ip_addr_any = IPADDR4_INIT(IPADDR_ANY);
48 const ip_addr_t ip_addr_broadcast = IPADDR4_INIT(IPADDR_BROADCAST);
49
50 /**
51 * Determine if an address is a broadcast address on a network interface
52 *
53 * @param addr address to be checked
54 * @param netif the network interface against which the address is checked
55 * @return returns non-zero if the address is a broadcast address
56 */
57 u8_t
ip4_addr_isbroadcast_u32(u32_t addr,const struct netif * netif)58 ip4_addr_isbroadcast_u32(u32_t addr, const struct netif *netif)
59 {
60 ip4_addr_t ipaddr;
61 ip4_addr_set_u32(&ipaddr, addr);
62
63 /* all ones (broadcast) or all zeroes (old skool broadcast) */
64 if ((~addr == IPADDR_ANY) ||
65 (addr == IPADDR_ANY)) {
66 return 1;
67 /* no broadcast support on this network interface? */
68 } else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) {
69 /* the given address cannot be a broadcast address
70 * nor can we check against any broadcast addresses */
71 return 0;
72 /* address matches network interface address exactly? => no broadcast */
73 } else if (addr == ip4_addr_get_u32(netif_ip4_addr(netif))) {
74 return 0;
75 /* on the same (sub) network... */
76 } else if (ip4_addr_netcmp(&ipaddr, netif_ip4_addr(netif), netif_ip4_netmask(netif))
77 /* ...and host identifier bits are all ones? =>... */
78 && ((addr & ~ip4_addr_get_u32(netif_ip4_netmask(netif))) ==
79 (IPADDR_BROADCAST & ~ip4_addr_get_u32(netif_ip4_netmask(netif))))) {
80 /* => network broadcast address */
81 return 1;
82 } else {
83 return 0;
84 }
85 }
86
87 /** Checks if a netmask is valid (starting with ones, then only zeros)
88 *
89 * @param netmask the IPv4 netmask to check (in network byte order!)
90 * @return 1 if the netmask is valid, 0 if it is not
91 */
92 u8_t
ip4_addr_netmask_valid(u32_t netmask)93 ip4_addr_netmask_valid(u32_t netmask)
94 {
95 u32_t mask;
96 u32_t nm_hostorder = lwip_htonl(netmask);
97
98 /* first, check for the first zero */
99 for (mask = 1UL << 31 ; mask != 0; mask >>= 1) {
100 if ((nm_hostorder & mask) == 0) {
101 break;
102 }
103 }
104 /* then check that there is no one */
105 for (; mask != 0; mask >>= 1) {
106 if ((nm_hostorder & mask) != 0) {
107 /* there is a one after the first zero -> invalid */
108 return 0;
109 }
110 }
111 /* no one after the first zero -> valid */
112 return 1;
113 }
114
115 /**
116 * Ascii internet address interpretation routine.
117 * The value returned is in network order.
118 *
119 * @param cp IP address in ascii representation (e.g. "127.0.0.1")
120 * @return ip address in network order
121 */
122 u32_t
ipaddr_addr(const char * cp)123 ipaddr_addr(const char *cp)
124 {
125 ip4_addr_t val;
126
127 if (ip4addr_aton(cp, &val)) {
128 return ip4_addr_get_u32(&val);
129 }
130 return (IPADDR_NONE);
131 }
132
133 /**
134 * Check whether "cp" is a valid ascii representation
135 * of an Internet address and convert to a binary address.
136 * Returns 1 if the address is valid, 0 if not.
137 * This replaces inet_addr, the return value from which
138 * cannot distinguish between failure and a local broadcast address.
139 *
140 * @param cp IP address in ascii representation (e.g. "127.0.0.1")
141 * @param addr pointer to which to save the ip address in network order
142 * @return 1 if cp could be converted to addr, 0 on failure
143 */
144 int
ip4addr_aton(const char * cp,ip4_addr_t * addr)145 ip4addr_aton(const char *cp, ip4_addr_t *addr)
146 {
147 u32_t val;
148 u8_t base;
149 char c;
150 u32_t parts[4];
151 u32_t *pp = parts;
152
153 c = *cp;
154 for (;;) {
155 /*
156 * Collect number up to ``.''.
157 * Values are specified as for C:
158 * 0x=hex, 0=octal, 1-9=decimal.
159 */
160 if (!lwip_isdigit(c)) {
161 return 0;
162 }
163 val = 0;
164 base = 10;
165 if (c == '0') {
166 c = *++cp;
167 if (c == 'x' || c == 'X') {
168 base = 16;
169 c = *++cp;
170 } else {
171 base = 8;
172 }
173 }
174 for (;;) {
175 if (lwip_isdigit(c)) {
176 val = (val * base) + (u32_t)(c - '0');
177 c = *++cp;
178 } else if (base == 16 && lwip_isxdigit(c)) {
179 val = (val << 4) | (u32_t)(c + 10 - (lwip_islower(c) ? 'a' : 'A'));
180 c = *++cp;
181 } else {
182 break;
183 }
184 }
185 if (c == '.') {
186 /*
187 * Internet format:
188 * a.b.c.d
189 * a.b.c (with c treated as 16 bits)
190 * a.b (with b treated as 24 bits)
191 */
192 if (pp >= parts + 3) {
193 return 0;
194 }
195 *pp++ = val;
196 c = *++cp;
197 } else {
198 break;
199 }
200 }
201 /*
202 * Check for trailing characters.
203 */
204 if (c != '\0' && !lwip_isspace(c)) {
205 return 0;
206 }
207 /*
208 * Concoct the address according to
209 * the number of parts specified.
210 */
211 switch (pp - parts + 1) {
212
213 case 0:
214 return 0; /* initial nondigit */
215
216 case 1: /* a -- 32 bits */
217 break;
218
219 case 2: /* a.b -- 8.24 bits */
220 if (val > 0xffffffUL) {
221 return 0;
222 }
223 if (parts[0] > 0xff) {
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 if ((parts[0] > 0xff) || (parts[1] > 0xff)) {
234 return 0;
235 }
236 val |= (parts[0] << 24) | (parts[1] << 16);
237 break;
238
239 case 4: /* a.b.c.d -- 8.8.8.8 bits */
240 if (val > 0xff) {
241 return 0;
242 }
243 if ((parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff)) {
244 return 0;
245 }
246 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
247 break;
248 default:
249 LWIP_ASSERT("unhandled", 0);
250 break;
251 }
252 if (addr) {
253 ip4_addr_set_u32(addr, lwip_htonl(val));
254 }
255 return 1;
256 }
257
258 /**
259 * Convert numeric IP address into decimal dotted ASCII representation.
260 * returns ptr to static buffer; not reentrant!
261 *
262 * @param addr ip address in network order to convert
263 * @return pointer to a global static (!) buffer that holds the ASCII
264 * representation of addr
265 */
266 char *
ip4addr_ntoa(const ip4_addr_t * addr)267 ip4addr_ntoa(const ip4_addr_t *addr)
268 {
269 static char str[IP4ADDR_STRLEN_MAX];
270 return ip4addr_ntoa_r(addr, str, IP4ADDR_STRLEN_MAX);
271 }
272
273 /**
274 * Same as ip4addr_ntoa, but reentrant since a user-supplied buffer is used.
275 *
276 * @param addr ip address in network order to convert
277 * @param buf target buffer where the string is stored
278 * @param buflen length of buf
279 * @return either pointer to buf which now holds the ASCII
280 * representation of addr or NULL if buf was too small
281 */
282 char *
ip4addr_ntoa_r(const ip4_addr_t * addr,char * buf,int buflen)283 ip4addr_ntoa_r(const ip4_addr_t *addr, char *buf, int buflen)
284 {
285 u32_t s_addr;
286 char inv[3];
287 char *rp;
288 u8_t *ap;
289 u8_t rem;
290 u8_t n;
291 u8_t i;
292 int len = 0;
293
294 s_addr = ip4_addr_get_u32(addr);
295
296 rp = buf;
297 ap = (u8_t *)&s_addr;
298 for (n = 0; n < 4; n++) {
299 i = 0;
300 do {
301 rem = *ap % (u8_t)10;
302 *ap /= (u8_t)10;
303 inv[i++] = (char)('0' + rem);
304 } while (*ap);
305 while (i--) {
306 if (len++ >= buflen) {
307 return NULL;
308 }
309 *rp++ = inv[i];
310 }
311 if (len++ >= buflen) {
312 return NULL;
313 }
314 *rp++ = '.';
315 ap++;
316 }
317 *--rp = 0;
318 return buf;
319 }
320
321 #endif /* LWIP_IPV4 */
322