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#include "lwip/ip_addr.h"
41#include "lwip/netif.h"
42#include <arranet_impl.h>
43
44/* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
45const ip_addr_t ip_addr_any = { IPADDR_ANY };
46const ip_addr_t ip_addr_broadcast = { IPADDR_BROADCAST };
47
48/**
49 * Determine if an address is a broadcast address on a network interface
50 *
51 * @param addr address to be checked
52 * @param netif the network interface against which the address is checked
53 * @return returns non-zero if the address is a broadcast address
54 */
55u8_t
56ip4_addr_isbroadcast(u32_t addr, const struct netif *netif)
57{
58  ip_addr_t ipaddr;
59  ip4_addr_set_u32(&ipaddr, addr);
60
61  /* all ones (broadcast) or all zeroes (old skool broadcast) */
62  if ((~addr == IPADDR_ANY) ||
63      (addr == IPADDR_ANY)) {
64    return 1;
65  /* no broadcast support on this network interface? */
66  } else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) {
67    /* the given address cannot be a broadcast address
68     * nor can we check against any broadcast addresses */
69    return 0;
70  /* address matches network interface address exactly? => no broadcast */
71  } else if (addr == ip4_addr_get_u32(&netif->ip_addr)) {
72    return 0;
73  /*  on the same (sub) network... */
74  } else if (ip_addr_netcmp(&ipaddr, &(netif->ip_addr), &(netif->netmask))
75         /* ...and host identifier bits are all ones? =>... */
76          && ((addr & ~ip4_addr_get_u32(&netif->netmask)) ==
77           (IPADDR_BROADCAST & ~ip4_addr_get_u32(&netif->netmask)))) {
78    /* => network broadcast address */
79    return 1;
80  } else {
81    return 0;
82  }
83}
84
85/** Checks if a netmask is valid (starting with ones, then only zeros)
86 *
87 * @param netmask the IPv4 netmask to check (in network byte order!)
88 * @return 1 if the netmask is valid, 0 if it is not
89 */
90u8_t
91ip4_addr_netmask_valid(u32_t netmask)
92{
93  u32_t mask;
94  u32_t nm_hostorder = lwip_htonl(netmask);
95
96  /* first, check for the first zero */
97  for (mask = 1UL << 31 ; mask != 0; mask >>= 1) {
98    if ((nm_hostorder & mask) == 0) {
99      break;
100    }
101  }
102  /* then check that there is no one */
103  for (; mask != 0; mask >>= 1) {
104    if ((nm_hostorder & mask) != 0) {
105      /* there is a one after the first zero -> invalid */
106      return 0;
107    }
108  }
109  /* no one after the first zero -> valid */
110  return 1;
111}
112
113/* Here for now until needed in other places in lwIP */
114#ifndef isprint
115#define in_range(c, lo, up)  ((u8_t)c >= lo && (u8_t)c <= up)
116#define isprint(c)           in_range(c, 0x20, 0x7f)
117#define isdigit(c)           in_range(c, '0', '9')
118#define isxdigit(c)          (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F'))
119#define islower(c)           in_range(c, 'a', 'z')
120#define isspace(c)           (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
121#endif
122
123/**
124 * Ascii internet address interpretation routine.
125 * The value returned is in network order.
126 *
127 * @param cp IP address in ascii represenation (e.g. "127.0.0.1")
128 * @return ip address in network order
129 */
130u32_t
131ipaddr_addr(const char *cp)
132{
133  ip_addr_t val;
134
135  if (ipaddr_aton(cp, &val)) {
136    return ip4_addr_get_u32(&val);
137  }
138  return (IPADDR_NONE);
139}
140
141/**
142 * Check whether "cp" is a valid ascii representation
143 * of an Internet address and convert to a binary address.
144 * Returns 1 if the address is valid, 0 if not.
145 * This replaces inet_addr, the return value from which
146 * cannot distinguish between failure and a local broadcast address.
147 *
148 * @param cp IP address in ascii represenation (e.g. "127.0.0.1")
149 * @param addr pointer to which to save the ip address in network order
150 * @return 1 if cp could be converted to addr, 0 on failure
151 */
152int
153ipaddr_aton(const char *cp, ip_addr_t *addr)
154{
155  u32_t val;
156  u8_t base;
157  char c;
158  u32_t parts[4];
159  u32_t *pp = parts;
160
161  c = *cp;
162  for (;;) {
163    /*
164     * Collect number up to ``.''.
165     * Values are specified as for C:
166     * 0x=hex, 0=octal, 1-9=decimal.
167     */
168    if (!isdigit(c))
169      return (0);
170    val = 0;
171    base = 10;
172    if (c == '0') {
173      c = *++cp;
174      if (c == 'x' || c == 'X') {
175        base = 16;
176        c = *++cp;
177      } else
178        base = 8;
179    }
180    for (;;) {
181      if (isdigit(c)) {
182        val = (val * base) + (int)(c - '0');
183        c = *++cp;
184      } else if (base == 16 && isxdigit(c)) {
185        val = (val << 4) | (int)(c + 10 - (islower(c) ? 'a' : 'A'));
186        c = *++cp;
187      } else
188        break;
189    }
190    if (c == '.') {
191      /*
192       * Internet format:
193       *  a.b.c.d
194       *  a.b.c   (with c treated as 16 bits)
195       *  a.b (with b treated as 24 bits)
196       */
197      if (pp >= parts + 3) {
198        return (0);
199      }
200      *pp++ = val;
201      c = *++cp;
202    } else
203      break;
204  }
205  /*
206   * Check for trailing characters.
207   */
208  if (c != '\0' && !isspace(c)) {
209    return (0);
210  }
211  /*
212   * Concoct the address according to
213   * the number of parts specified.
214   */
215  switch (pp - parts + 1) {
216
217  case 0:
218    return (0);       /* initial nondigit */
219
220  case 1:             /* a -- 32 bits */
221    break;
222
223  case 2:             /* a.b -- 8.24 bits */
224    if (val > 0xffffffUL) {
225      return (0);
226    }
227    val |= parts[0] << 24;
228    break;
229
230  case 3:             /* a.b.c -- 8.8.16 bits */
231    if (val > 0xffff) {
232      return (0);
233    }
234    val |= (parts[0] << 24) | (parts[1] << 16);
235    break;
236
237  case 4:             /* a.b.c.d -- 8.8.8.8 bits */
238    if (val > 0xff) {
239      return (0);
240    }
241    val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
242    break;
243  default:
244    LWIP_ASSERT("unhandled", 0);
245    break;
246  }
247  if (addr) {
248    ip4_addr_set_u32(addr, htonl(val));
249  }
250  return (1);
251}
252
253/**
254 * Convert numeric IP address into decimal dotted ASCII representation.
255 * returns ptr to static buffer; not reentrant!
256 *
257 * @param addr ip address in network order to convert
258 * @return pointer to a global static (!) buffer that holds the ASCII
259 *         represenation of addr
260 */
261char *
262ipaddr_ntoa(const ip_addr_t *addr)
263{
264  static char str[16];
265  return ipaddr_ntoa_r(addr, str, 16);
266}
267
268/**
269 * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
270 *
271 * @param addr ip address in network order to convert
272 * @param buf target buffer where the string is stored
273 * @param buflen length of buf
274 * @return either pointer to buf which now holds the ASCII
275 *         representation of addr or NULL if buf was too small
276 */
277char *ipaddr_ntoa_r(const ip_addr_t *addr, char *buf, int buflen)
278{
279  u32_t s_addr;
280  char inv[3];
281  char *rp;
282  u8_t *ap;
283  u8_t rem;
284  u8_t n;
285  u8_t i;
286  int len = 0;
287
288  s_addr = ip4_addr_get_u32(addr);
289
290  rp = buf;
291  ap = (u8_t *)&s_addr;
292  for(n = 0; n < 4; n++) {
293    i = 0;
294    do {
295      rem = *ap % (u8_t)10;
296      *ap /= (u8_t)10;
297      inv[i++] = '0' + rem;
298    } while(*ap);
299    while(i--) {
300      if (len++ >= buflen) {
301        return NULL;
302      }
303      *rp++ = inv[i];
304    }
305    if (len++ >= buflen) {
306      return NULL;
307    }
308    *rp++ = '.';
309    ap++;
310  }
311  *--rp = 0;
312  return buf;
313}
314