ermyth/src/cidr.C

/**
 * cidr.C: CIDR matching.
 * Rights to this code are documented in doc/pod/license.pod.
 *
 * Most code in this file has been copied from ratbox, src/match.c and
 * src/irc_string.c. It provides CIDR matching for IPv4 and IPv6 without
 * special OS support.
 *
 * Copyright © 1996-2002 Hybrid Development Team
 * Copyright © 2002-2005 ircd-ratbox development team
 * Copyright © 2005-2007 Atheme Project (http://www.atheme.org)           
 */

static char const rcsid[] = "$Id$";

#include "atheme.h"

#ifndef INADDRSZ
#define INADDRSZ 4
#endif
#ifndef IN6ADDRSZ
#define IN6ADDRSZ 16
#endif
#ifndef INT16SZ
#define INT16SZ 2
#endif

/* compares the first 'mask' bits
 * returns 1 if equal, 0 if not */
static int
comp_with_mask (void *addr, void *dest, unsigned mask)
{
  if (memcmp (addr, dest, mask / 8) == 0)
    {
      int n = mask / 8;
      int m = ((-1) << (8 - (mask % 8)));
      if (mask % 8 == 0 || (((unsigned char *) addr)[n] & m) == (((unsigned char *) dest)[n] & m))
        {
          return (1);
        }
    }
  return (0);
}

/*
 * inet_pton4() and inet_pton6() are
 * Copyright © 1996-1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * WARNING: Don't even consider trying to compile this on a system where
 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
 */

/* int
 * inet_pton4(src, dst)
 *      like inet_aton() but without all the hexadecimal and shorthand.
 * return:
 *      1 if `src' is a valid dotted quad, else 0.
 * notice:
 *      does not touch `dst' unless it's returning 1.
 * author:
 *      Paul Vixie, 1996.
 */
static int
inet_pton4 (char const *src, unsigned char *dst)
{
  int saw_digit, octets, ch;
  unsigned char tmp[INADDRSZ], *tp;

  saw_digit = 0;
  octets = 0;
  *(tp = tmp) = 0;
  while ((ch = *src++) != '\0')
    {
      if (ch >= '0' && ch <= '9')
        {
          unsigned newtp = *tp * 10 + (ch - '0');

          if (newtp > 255)
            return (0);
          *tp = newtp;
          if (!saw_digit)
            {
              if (++octets > 4)
                return (0);
              saw_digit = 1;
            }
        }
      else if (ch == '.' && saw_digit)
        {
          if (octets == 4)
            return (0);
          *++tp = 0;
          saw_digit = 0;
        }
      else
        return (0);
    }
  if (octets < 4)
    return (0);
  memcpy (dst, tmp, INADDRSZ);
  return (1);
}

/* int
 * inet_pton6(src, dst)
 *      convert presentation level address to network order binary form.
 * return:
 *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 * notice:
 *      (1) does not touch `dst' unless it's returning 1.
 *      (2) :: in a full address is silently ignored.
 * credit:
 *      inspired by Mark Andrews.
 * author:
 *      Paul Vixie, 1996.
 */
static int
inet_pton6 (char const *src, unsigned char *dst)
{
  static const char xdigits[] = "0123456789abcdef";
  unsigned char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
  const char *curtok;
  int ch, saw_xdigit;
  unsigned val;

  tp = static_cast<unsigned char *> (memset (tmp, '\0', IN6ADDRSZ));
  endp = tp + IN6ADDRSZ;
  colonp = NULL;
  /* Leading :: requires some special handling. */
  if (*src == ':')
    if (*++src != ':')
      return (0);
  curtok = src;
  saw_xdigit = 0;
  val = 0;
  while ((ch = tolower (*src++)) != '\0')
    {
      const char *pch;

      pch = strchr (xdigits, ch);
      if (pch != NULL)
        {
          val <<= 4;
          val |= (pch - xdigits);
          if (val > 0xffff)
            return (0);
          saw_xdigit = 1;
          continue;
        }
      if (ch == ':')
        {
          curtok = src;
          if (!saw_xdigit)
            {
              if (colonp)
                return (0);
              colonp = tp;
              continue;
            }
          else if (*src == '\0')
            {
              return (0);
            }
          if (tp + INT16SZ > endp)
            return (0);
          *tp++ = (unsigned char) (val >> 8) & 0xff;
          *tp++ = (unsigned char) val & 0xff;
          saw_xdigit = 0;
          val = 0;
          continue;
        }
      if (*src != '\0' && ch == '.')
        {
          if (((tp + INADDRSZ) <= endp) && inet_pton4 (curtok, tp) > 0)
            {
              tp += INADDRSZ;
              saw_xdigit = 0;
              break;            /* '\0' was seen by inet_pton4(). */
            }
        }
      else
        continue;
      return (0);
    }
  if (saw_xdigit)
    {
      if (tp + INT16SZ > endp)
        return (0);
      *tp++ = (unsigned char) (val >> 8) & 0xff;
      *tp++ = (unsigned char) val & 0xff;
    }
  if (colonp != NULL)
    {
      /*
       * Since some memmove()'s erroneously fail to handle
       * overlapping regions, we'll do the shift by hand.
       */
      const int n = tp - colonp;
      int i;

      if (tp == endp)
        return (0);
      for (i = 1; i <= n; i++)
        {
          endp[-i] = colonp[n - i];
          colonp[n - i] = 0;
        }
      tp = endp;
    }
  if (tp != endp)
    return (0);
  memcpy (dst, tmp, IN6ADDRSZ);
  return (1);
}

/*
 * match_ips()
 *
 * Input - cidr ip mask, address
 * Output - 0 = Matched 1 = Did not match
 * switched 0 and 1 to be consistent with match() -- jilles
 */
int
match_ips (const char *s1, const char *s2)
{
  unsigned char ipaddr[IN6ADDRSZ], maskaddr[IN6ADDRSZ];
  char ipmask[BUFSIZE];
  char ip[HOSTLEN + 1];
  char *len;
  int cidrlen;

  strlcpy (ipmask, s1, sizeof ipmask);
  strlcpy (ip, s2, sizeof ip);

  len = strrchr (ipmask, '/');
  if (len == NULL)
    return 1;

  *len++ = '\0';

  cidrlen = atoi (len);
  if (cidrlen == 0)
    return 1;

  if (strchr (ip, ':') && strchr (ipmask, ':'))
    {
      if (cidrlen > 128)
        return 1;
      if (!inet_pton6 (ip, ipaddr))
        return 1;
      if (!inet_pton6 (ipmask, maskaddr))
        return 1;
      return !comp_with_mask (ipaddr, maskaddr, cidrlen);
    }
  else if (!strchr (ip, ':') && !strchr (ipmask, ':'))
    {
      if (cidrlen > 32)
        return 1;
      if (!inet_pton4 (ip, ipaddr))
        return 1;
      if (!inet_pton4 (ipmask, maskaddr))
        return 1;
      return !comp_with_mask (ipaddr, maskaddr, cidrlen);
    }
  else
    return 1;
}

/* match_cidr()
 *
 * Input - mask n!u@i/c, address n!u@i
 * Output - 0 = Matched 1 = Did not match
 * switched 0 and 1 to be consistent with match() -- jilles
 */
int
match_cidr (const char *s1, const char *s2)
{
  unsigned char ipaddr[IN6ADDRSZ], maskaddr[IN6ADDRSZ];
  char mask[BUFSIZE];
  char address[NICKLEN + USERLEN + HOSTLEN + 6];
  char *ipmask;
  char *ip;
  char *len;
  int cidrlen;

  strlcpy (mask, s1, sizeof mask);
  strlcpy (address, s2, sizeof address);

  ipmask = strrchr (mask, '@');
  if (ipmask == NULL)
    return 1;

  *ipmask++ = '\0';

  ip = strrchr (address, '@');
  if (ip == NULL)
    return 1;
  *ip++ = '\0';

  len = strrchr (ipmask, '/');
  if (len == NULL)
    return 1;

  *len++ = '\0';

  cidrlen = atoi (len);
  if (cidrlen == 0)
    return 1;

  if (strchr (ip, ':') && strchr (ipmask, ':'))
    {
      if (cidrlen > 128)
        return 1;
      if (!inet_pton6 (ip, ipaddr))
        return 1;
      if (!inet_pton6 (ipmask, maskaddr))
        return 1;
      return !comp_with_mask (ipaddr, maskaddr, cidrlen) || match (mask, address);
    }
  else if (!strchr (ip, ':') && !strchr (ipmask, ':'))
    {
      if (cidrlen > 32)
        return 1;
      if (!inet_pton4 (ip, ipaddr))
        return 1;
      if (!inet_pton4 (ipmask, maskaddr))
        return 1;
      return !comp_with_mask (ipaddr, maskaddr, cidrlen) || match (mask, address);
    }
  else
    return 1;
}

/* vim:cinoptions=>s,e0,n0,f0,{0,}0,^0,=s,ps,t0,c3,+s,(2s,us,)20,*30,gs,hs
 * vim:ts=8
 * vim:sw=8
 * vim:noexpandtab
 */
Revision:	1.3
Committed:	Sat Jul 21 13:23:21 2007 UTC (19 years, 1 month ago) by pippijn
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+1 -1 lines
Log Message:	- added rcsid to some files - more documentation tweaks - made most protocol commands local to phandler.C - added ircd metadata (inspircd only for now) - added inspircd swhois support
#	User	Rev	Content
1	pippijn	1.1	/**
2			* cidr.C: CIDR matching.
3	pippijn	1.2	* Rights to this code are documented in doc/pod/license.pod.
4	pippijn	1.1	*
5			* Most code in this file has been copied from ratbox, src/match.c and
6			* src/irc_string.c. It provides CIDR matching for IPv4 and IPv6 without
7			* special OS support.
8			*
9			* Copyright © 1996-2002 Hybrid Development Team
10			* Copyright © 2002-2005 ircd-ratbox development team
11			* Copyright © 2005-2007 Atheme Project (http://www.atheme.org)
12			*/
13
14	pippijn	1.3	static char const rcsid[] = "$Id$";
15	pippijn	1.1
16			#include "atheme.h"
17
18			#ifndef INADDRSZ
19			#define INADDRSZ 4
20			#endif
21			#ifndef IN6ADDRSZ
22			#define IN6ADDRSZ 16
23			#endif
24			#ifndef INT16SZ
25			#define INT16SZ 2
26			#endif
27
28			/* compares the first 'mask' bits
29			* returns 1 if equal, 0 if not */
30			static int
31			comp_with_mask (void addr, void dest, unsigned mask)
32			{
33			if (memcmp (addr, dest, mask / 8) == 0)
34			{
35			int n = mask / 8;
36			int m = ((-1) << (8 - (mask % 8)));
37			if (mask % 8 == 0 \|\| (((unsigned char ) addr)[n] & m) == (((unsigned char ) dest)[n] & m))
38			{
39			return (1);
40			}
41			}
42			return (0);
43			}
44
45			/*
46			* inet_pton4() and inet_pton6() are
47			* Copyright © 1996-1999 by Internet Software Consortium.
48			*
49			* Permission to use, copy, modify, and distribute this software for any
50			* purpose with or without fee is hereby granted, provided that the above
51			* copyright notice and this permission notice appear in all copies.
52			*
53			* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
54			* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
55			* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
56			* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
57			* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
58			* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
59			* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
60			* SOFTWARE.
61			*/
62
63			/*
64			* WARNING: Don't even consider trying to compile this on a system where
65			* sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
66			*/
67
68			/* int
69			* inet_pton4(src, dst)
70			* like inet_aton() but without all the hexadecimal and shorthand.
71			* return:
72			* 1 if `src' is a valid dotted quad, else 0.
73			* notice:
74			* does not touch `dst' unless it's returning 1.
75			* author:
76			* Paul Vixie, 1996.
77			*/
78			static int
79			inet_pton4 (char const src, unsigned char dst)
80			{
81			int saw_digit, octets, ch;
82			unsigned char tmp[INADDRSZ], *tp;
83
84			saw_digit = 0;
85			octets = 0;
86			*(tp = tmp) = 0;
87			while ((ch = *src++) != '\0')
88			{
89			if (ch >= '0' && ch <= '9')
90			{
91			unsigned newtp = tp 10 + (ch - '0');
92
93			if (newtp > 255)
94			return (0);
95			*tp = newtp;
96			if (!saw_digit)
97			{
98			if (++octets > 4)
99			return (0);
100			saw_digit = 1;
101			}
102			}
103			else if (ch == '.' && saw_digit)
104			{
105			if (octets == 4)
106			return (0);
107			*++tp = 0;
108			saw_digit = 0;
109			}
110			else
111			return (0);
112			}
113			if (octets < 4)
114			return (0);
115			memcpy (dst, tmp, INADDRSZ);
116			return (1);
117			}
118
119			/* int
120			* inet_pton6(src, dst)
121			* convert presentation level address to network order binary form.
122			* return:
123			* 1 if `src' is a valid [RFC1884 2.2] address, else 0.
124			* notice:
125			* (1) does not touch `dst' unless it's returning 1.
126			* (2) :: in a full address is silently ignored.
127			* credit:
128			* inspired by Mark Andrews.
129			* author:
130			* Paul Vixie, 1996.
131			*/
132			static int
133			inet_pton6 (char const src, unsigned char dst)
134			{
135			static const char xdigits[] = "0123456789abcdef";
136			unsigned char tmp[IN6ADDRSZ], tp, endp, *colonp;
137			const char *curtok;
138			int ch, saw_xdigit;
139			unsigned val;
140
141			tp = static_cast<unsigned char *> (memset (tmp, '\0', IN6ADDRSZ));
142			endp = tp + IN6ADDRSZ;
143			colonp = NULL;
144			/* Leading :: requires some special handling. */
145			if (*src == ':')
146			if (*++src != ':')
147			return (0);
148			curtok = src;
149			saw_xdigit = 0;
150			val = 0;
151			while ((ch = tolower (*src++)) != '\0')
152			{
153			const char *pch;
154
155			pch = strchr (xdigits, ch);
156			if (pch != NULL)
157			{
158			val <<= 4;
159			val \|= (pch - xdigits);
160			if (val > 0xffff)
161			return (0);
162			saw_xdigit = 1;
163			continue;
164			}
165			if (ch == ':')
166			{
167			curtok = src;
168			if (!saw_xdigit)
169			{
170			if (colonp)
171			return (0);
172			colonp = tp;
173			continue;
174			}
175			else if (*src == '\0')
176			{
177			return (0);
178			}
179			if (tp + INT16SZ > endp)
180			return (0);
181			*tp++ = (unsigned char) (val >> 8) & 0xff;
182			*tp++ = (unsigned char) val & 0xff;
183			saw_xdigit = 0;
184			val = 0;
185			continue;
186			}
187			if (*src != '\0' && ch == '.')
188			{
189			if (((tp + INADDRSZ) <= endp) && inet_pton4 (curtok, tp) > 0)
190			{
191			tp += INADDRSZ;
192			saw_xdigit = 0;
193			break; /* '\0' was seen by inet_pton4(). */
194			}
195			}
196			else
197			continue;
198			return (0);
199			}
200			if (saw_xdigit)
201			{
202			if (tp + INT16SZ > endp)
203			return (0);
204			*tp++ = (unsigned char) (val >> 8) & 0xff;
205			*tp++ = (unsigned char) val & 0xff;
206			}
207			if (colonp != NULL)
208			{
209			/*
210			* Since some memmove()'s erroneously fail to handle
211			* overlapping regions, we'll do the shift by hand.
212			*/
213			const int n = tp - colonp;
214			int i;
215
216			if (tp == endp)
217			return (0);
218			for (i = 1; i <= n; i++)
219			{
220			endp[-i] = colonp[n - i];
221			colonp[n - i] = 0;
222			}
223			tp = endp;
224			}
225			if (tp != endp)
226			return (0);
227			memcpy (dst, tmp, IN6ADDRSZ);
228			return (1);
229			}
230
231			/*
232			* match_ips()
233			*
234			* Input - cidr ip mask, address
235			* Output - 0 = Matched 1 = Did not match
236			* switched 0 and 1 to be consistent with match() -- jilles
237			*/
238			int
239			match_ips (const char s1, const char s2)
240			{
241			unsigned char ipaddr[IN6ADDRSZ], maskaddr[IN6ADDRSZ];
242			char ipmask[BUFSIZE];
243			char ip[HOSTLEN + 1];
244			char *len;
245			int cidrlen;
246
247			strlcpy (ipmask, s1, sizeof ipmask);
248			strlcpy (ip, s2, sizeof ip);
249
250			len = strrchr (ipmask, '/');
251			if (len == NULL)
252			return 1;
253
254			*len++ = '\0';
255
256			cidrlen = atoi (len);
257			if (cidrlen == 0)
258			return 1;
259
260			if (strchr (ip, ':') && strchr (ipmask, ':'))
261			{
262			if (cidrlen > 128)
263			return 1;
264			if (!inet_pton6 (ip, ipaddr))
265			return 1;
266			if (!inet_pton6 (ipmask, maskaddr))
267			return 1;
268			return !comp_with_mask (ipaddr, maskaddr, cidrlen);
269			}
270			else if (!strchr (ip, ':') && !strchr (ipmask, ':'))
271			{
272			if (cidrlen > 32)
273			return 1;
274			if (!inet_pton4 (ip, ipaddr))
275			return 1;
276			if (!inet_pton4 (ipmask, maskaddr))
277			return 1;
278			return !comp_with_mask (ipaddr, maskaddr, cidrlen);
279			}
280			else
281			return 1;
282			}
283
284			/* match_cidr()
285			*
286			* Input - mask n!u@i/c, address n!u@i
287			* Output - 0 = Matched 1 = Did not match
288			* switched 0 and 1 to be consistent with match() -- jilles
289			*/
290			int
291			match_cidr (const char s1, const char s2)
292			{
293			unsigned char ipaddr[IN6ADDRSZ], maskaddr[IN6ADDRSZ];
294			char mask[BUFSIZE];
295			char address[NICKLEN + USERLEN + HOSTLEN + 6];
296			char *ipmask;
297			char *ip;
298			char *len;
299			int cidrlen;
300
301			strlcpy (mask, s1, sizeof mask);
302			strlcpy (address, s2, sizeof address);
303
304			ipmask = strrchr (mask, '@');
305			if (ipmask == NULL)
306			return 1;
307
308			*ipmask++ = '\0';
309
310			ip = strrchr (address, '@');
311			if (ip == NULL)
312			return 1;
313			*ip++ = '\0';
314
315			len = strrchr (ipmask, '/');
316			if (len == NULL)
317			return 1;
318
319			*len++ = '\0';
320
321			cidrlen = atoi (len);
322			if (cidrlen == 0)
323			return 1;
324
325			if (strchr (ip, ':') && strchr (ipmask, ':'))
326			{
327			if (cidrlen > 128)
328			return 1;
329			if (!inet_pton6 (ip, ipaddr))
330			return 1;
331			if (!inet_pton6 (ipmask, maskaddr))
332			return 1;
333			return !comp_with_mask (ipaddr, maskaddr, cidrlen) \|\| match (mask, address);
334			}
335			else if (!strchr (ip, ':') && !strchr (ipmask, ':'))
336			{
337			if (cidrlen > 32)
338			return 1;
339			if (!inet_pton4 (ip, ipaddr))
340			return 1;
341			if (!inet_pton4 (ipmask, maskaddr))
342			return 1;
343			return !comp_with_mask (ipaddr, maskaddr, cidrlen) \|\| match (mask, address);
344			}
345			else
346			return 1;
347			}
348
349			/* vim:cinoptions=>s,e0,n0,f0,{0,}0,^0,=s,ps,t0,c3,+s,(2s,us,)20,*30,gs,hs
350			* vim:ts=8
351			* vim:sw=8
352			* vim:noexpandtab
353			*/