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1 office 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 <adam@sics.se>
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
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
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 /* Here for now until needed in other places in lwIP */
116 #ifndef isprint
117 #define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up)
118 #define isprint(c) in_range(c, 0x20, 0x7f)
119 #define isdigit(c) in_range(c, '0', '9')
120 #define isxdigit(c) (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F'))
121 #define islower(c) in_range(c, 'a', 'z')
122 #define isspace(c) (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
123 #endif
124  
125 /**
126 * Ascii internet address interpretation routine.
127 * The value returned is in network order.
128 *
129 * @param cp IP address in ascii representation (e.g. "127.0.0.1")
130 * @return ip address in network order
131 */
132 u32_t
133 ipaddr_addr(const char *cp)
134 {
135 ip4_addr_t val;
136  
137 if (ip4addr_aton(cp, &val)) {
138 return ip4_addr_get_u32(&val);
139 }
140 return (IPADDR_NONE);
141 }
142  
143 /**
144 * Check whether "cp" is a valid ascii representation
145 * of an Internet address and convert to a binary address.
146 * Returns 1 if the address is valid, 0 if not.
147 * This replaces inet_addr, the return value from which
148 * cannot distinguish between failure and a local broadcast address.
149 *
150 * @param cp IP address in ascii representation (e.g. "127.0.0.1")
151 * @param addr pointer to which to save the ip address in network order
152 * @return 1 if cp could be converted to addr, 0 on failure
153 */
154 int
155 ip4addr_aton(const char *cp, ip4_addr_t *addr)
156 {
157 u32_t val;
158 u8_t base;
159 char c;
160 u32_t parts[4];
161 u32_t *pp = parts;
162  
163 c = *cp;
164 for (;;) {
165 /*
166 * Collect number up to ``.''.
167 * Values are specified as for C:
168 * 0x=hex, 0=octal, 1-9=decimal.
169 */
170 if (!isdigit(c)) {
171 return 0;
172 }
173 val = 0;
174 base = 10;
175 if (c == '0') {
176 c = *++cp;
177 if (c == 'x' || c == 'X') {
178 base = 16;
179 c = *++cp;
180 } else {
181 base = 8;
182 }
183 }
184 for (;;) {
185 if (isdigit(c)) {
186 val = (val * base) + (u32_t)(c - '0');
187 c = *++cp;
188 } else if (base == 16 && isxdigit(c)) {
189 val = (val << 4) | (u32_t)(c + 10 - (islower(c) ? 'a' : 'A'));
190 c = *++cp;
191 } else {
192 break;
193 }
194 }
195 if (c == '.') {
196 /*
197 * Internet format:
198 * a.b.c.d
199 * a.b.c (with c treated as 16 bits)
200 * a.b (with b treated as 24 bits)
201 */
202 if (pp >= parts + 3) {
203 return 0;
204 }
205 *pp++ = val;
206 c = *++cp;
207 } else {
208 break;
209 }
210 }
211 /*
212 * Check for trailing characters.
213 */
214 if (c != '\0' && !isspace(c)) {
215 return 0;
216 }
217 /*
218 * Concoct the address according to
219 * the number of parts specified.
220 */
221 switch (pp - parts + 1) {
222  
223 case 0:
224 return 0; /* initial nondigit */
225  
226 case 1: /* a -- 32 bits */
227 break;
228  
229 case 2: /* a.b -- 8.24 bits */
230 if (val > 0xffffffUL) {
231 return 0;
232 }
233 if (parts[0] > 0xff) {
234 return 0;
235 }
236 val |= parts[0] << 24;
237 break;
238  
239 case 3: /* a.b.c -- 8.8.16 bits */
240 if (val > 0xffff) {
241 return 0;
242 }
243 if ((parts[0] > 0xff) || (parts[1] > 0xff)) {
244 return 0;
245 }
246 val |= (parts[0] << 24) | (parts[1] << 16);
247 break;
248  
249 case 4: /* a.b.c.d -- 8.8.8.8 bits */
250 if (val > 0xff) {
251 return 0;
252 }
253 if ((parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff)) {
254 return 0;
255 }
256 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
257 break;
258 default:
259 LWIP_ASSERT("unhandled", 0);
260 break;
261 }
262 if (addr) {
263 ip4_addr_set_u32(addr, lwip_htonl(val));
264 }
265 return 1;
266 }
267  
268 /**
269 * Convert numeric IP address into decimal dotted ASCII representation.
270 * returns ptr to static buffer; not reentrant!
271 *
272 * @param addr ip address in network order to convert
273 * @return pointer to a global static (!) buffer that holds the ASCII
274 * representation of addr
275 */
276 char *
277 ip4addr_ntoa(const ip4_addr_t *addr)
278 {
279 static char str[IP4ADDR_STRLEN_MAX];
280 return ip4addr_ntoa_r(addr, str, IP4ADDR_STRLEN_MAX);
281 }
282  
283 /**
284 * Same as ip4addr_ntoa, but reentrant since a user-supplied buffer is used.
285 *
286 * @param addr ip address in network order to convert
287 * @param buf target buffer where the string is stored
288 * @param buflen length of buf
289 * @return either pointer to buf which now holds the ASCII
290 * representation of addr or NULL if buf was too small
291 */
292 char *
293 ip4addr_ntoa_r(const ip4_addr_t *addr, char *buf, int buflen)
294 {
295 u32_t s_addr;
296 char inv[3];
297 char *rp;
298 u8_t *ap;
299 u8_t rem;
300 u8_t n;
301 u8_t i;
302 int len = 0;
303  
304 s_addr = ip4_addr_get_u32(addr);
305  
306 rp = buf;
307 ap = (u8_t *)&s_addr;
308 for (n = 0; n < 4; n++) {
309 i = 0;
310 do {
311 rem = *ap % (u8_t)10;
312 *ap /= (u8_t)10;
313 inv[i++] = (char)('0' + rem);
314 } while (*ap);
315 while (i--) {
316 if (len++ >= buflen) {
317 return NULL;
318 }
319 *rp++ = inv[i];
320 }
321 if (len++ >= buflen) {
322 return NULL;
323 }
324 *rp++ = '.';
325 ap++;
326 }
327 *--rp = 0;
328 return buf;
329 }
330  
331 #endif /* LWIP_IPV4 */