ircu2/ircd/match.c

886 lines
26 KiB
C

/*
* IRC - Internet Relay Chat, common/match.c
* Copyright (C) 1990 Jarkko Oikarinen
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 1, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file
* @brief Functions to match strings against IRC mask strings.
* @version $Id: match.c 1891 2008-11-18 02:30:15Z entrope $
*/
#include "config.h"
#include "match.h"
#include "ircd_chattr.h"
#include "ircd_string.h"
#include "ircd_snprintf.h"
/*
* mmatch()
*
* Written by Run (carlo@runaway.xs4all.nl), 25-10-96
*
*
* From: Carlo Wood <carlo@runaway.xs4all.nl>
* Message-Id: <199609021026.MAA02393@runaway.xs4all.nl>
* Subject: [C-Com] Analysis for `mmatch' (was: gline4 problem)
* To: coder-com@mail.undernet.org (coder committee)
* Date: Mon, 2 Sep 1996 12:26:01 +0200 (MET DST)
*
* We need a new function `mmatch(const char *old_mask, const char *new_mask)'
* which returns `true' likewise the current `match' (start with copying it),
* but which treats '*' and '?' in `new_mask' differently (not "\*" and "\?" !)
* as follows: a '*' in `new_mask' does not match a '?' in `old_mask' and
* a '?' in `new_mask' does not match a '\?' in `old_mask'.
* And ofcourse... a '*' in `new_mask' does not match a '\*' in `old_mask'...
* And last but not least, '\?' and '\*' in `new_mask' now become one character.
*/
/** Compares one mask against another.
* One wildcard mask may be said to be a superset of another if the
* set of strings matched by the first is a proper superset of the set
* of strings matched by the second. In practical terms, this means
* that the second is made redundant by the first.
*
* The logic for this test is similar to that in match(), but a
* backslash in old_mask only matches a backslash in new_mask (and
* requires the next character to match exactly), and -- after
* contiguous runs of wildcards are logically collapsed -- a '?' in
* old_mask does not match a '*' in new_mask.
*
* @param[in] old_mask One wildcard mask.
* @param[in] new_mask Another wildcard mask.
* @return Zero if \a old_mask is a superset of \a new_mask, non-zero otherwise.
*/
int mmatch(const char *old_mask, const char *new_mask)
{
const char *m = old_mask;
const char *n = new_mask;
const char *ma = m;
const char *na = n;
int wild = 0;
int mq = 0, nq = 0;
while (1)
{
if (*m == '*')
{
while (*m == '*')
m++;
wild = 1;
ma = m;
na = n;
}
if (!*m)
{
if (!*n)
return 0;
for (m--; (m > old_mask) && (*m == '?'); m--)
;
if ((*m == '*') && (m > old_mask) && (m[-1] != '\\'))
return 0;
if (!wild)
return 1;
m = ma;
/* Added to `mmatch' : Because '\?' and '\*' now is one character: */
if ((*na == '\\') && ((na[1] == '*') || (na[1] == '?')))
++na;
n = ++na;
}
else if (!*n)
{
while (*m == '*')
m++;
return (*m != 0);
}
if ((*m == '\\') && ((m[1] == '*') || (m[1] == '?')))
{
m++;
mq = 1;
}
else
mq = 0;
/* Added to `mmatch' : Because '\?' and '\*' now is one character: */
if ((*n == '\\') && ((n[1] == '*') || (n[1] == '?')))
{
n++;
nq = 1;
}
else
nq = 0;
/*
* This `if' has been changed compared to match() to do the following:
* Match when:
* old (m) new (n) boolean expression
* * any (*m == '*' && !mq) ||
* ? any except '*' (*m == '?' && !mq && (*n != '*' || nq)) ||
* any except * or ? same as m (!((*m == '*' || *m == '?') && !mq) &&
* ToLower(*m) == ToLower(*n) &&
* !((mq && !nq) || (!mq && nq)))
*
* Here `any' also includes \* and \? !
*
* After reworking the boolean expressions, we get:
* (Optimized to use boolean short-circuits, with most frequently occurring
* cases upfront (which took 2 hours!)).
*/
if ((*m == '*' && !mq) ||
((!mq || nq) && ToLower(*m) == ToLower(*n)) ||
(*m == '?' && !mq && (*n != '*' || nq)))
{
if (*m)
m++;
if (*n)
n++;
}
else
{
if (!wild)
return 1;
m = ma;
/* Added to `mmatch' : Because '\?' and '\*' now is one character: */
if ((*na == '\\') && ((na[1] == '*') || (na[1] == '?')))
++na;
n = ++na;
}
}
}
/*
* Compare if a given string (name) matches the given
* mask (which can contain wild cards: '*' - match any
* number of chars, '?' - match any single character.
*
* return 0, if match
* 1, if no match
*
* Originally by Douglas A Lewis (dalewis@acsu.buffalo.edu)
* Rewritten by Timothy Vogelsang (netski), net@astrolink.org
*/
/** Check a string against a mask.
* This test checks using traditional IRC wildcards only: '*' means
* match zero or more characters of any type; '?' means match exactly
* one character of any type. A backslash escapes the next character
* so that a wildcard may be matched exactly.
* @param[in] mask Wildcard-containing mask.
* @param[in] name String to check against \a mask.
* @return Zero if \a mask matches \a name, non-zero if no match.
*/
int match(const char *mask, const char *name)
{
const char *m = mask, *n = name;
const char *m_tmp = mask, *n_tmp = name;
int star_p;
for (;;) switch (*m) {
case '\0':
if (!*n)
return 0;
backtrack:
if (m_tmp == mask)
return 1;
m = m_tmp;
n = ++n_tmp;
if (*n == '\0')
return 1;
break;
case '\\':
m++;
/* allow escaping to force capitalization */
if (*m++ != *n++)
goto backtrack;
break;
case '*': case '?':
for (star_p = 0; ; m++) {
if (*m == '*')
star_p = 1;
else if (*m == '?') {
if (!*n++)
goto backtrack;
} else break;
}
if (star_p) {
if (!*m)
return 0;
else if (*m == '\\') {
m_tmp = ++m;
if (!*m)
return 1;
for (n_tmp = n; *n && *n != *m; n++) ;
} else {
m_tmp = m;
for (n_tmp = n; *n && ToLower(*n) != ToLower(*m); n++) ;
}
}
/* and fall through */
default:
if (!*n)
return *m != '\0';
if (ToLower(*m) != ToLower(*n))
goto backtrack;
m++;
n++;
break;
}
}
/*
* collapse()
* Collapse a pattern string into minimal components.
* This particular version is "in place", so that it changes the pattern
* which is to be reduced to a "minimal" size.
*
* (C) Carlo Wood - 6 Oct 1998
* Speedup rewrite by Andrea Cocito, December 1998.
* Note that this new optimized algorithm can *only* work in place.
*/
/** Collapse a mask string to remove redundancies.
* Specifically, it replaces a sequence of '*' followed by additional
* '*' or '?' with the same number of '?'s as the input, followed by
* one '*'. This minimizes useless backtracking when matching later.
* @param[in,out] mask Mask string to collapse.
* @return Pointer to the start of the string.
*/
char *collapse(char *mask)
{
int star = 0;
char *m = mask;
char *b;
if (m)
{
do
{
if ((*m == '*') && ((m[1] == '*') || (m[1] == '?')))
{
b = m;
do
{
if (*m == '*')
star = 1;
else
{
if (star && (*m != '?'))
{
*b++ = '*';
star = 0;
};
*b++ = *m;
if ((*m == '\\') && ((m[1] == '*') || (m[1] == '?')))
*b++ = *++m;
};
}
while (*m++);
break;
}
else
{
if ((*m == '\\') && ((m[1] == '*') || (m[1] == '?')))
m++;
};
}
while (*m++);
};
return mask;
}
/*
***************** Nemesi's matchcomp() / matchexec() **************
*/
/** @page compiledmasks Compiled Masks
* These functions allow the use of "compiled" masks, you compile a mask
* by means of matchcomp() that gets the plain text mask as input and writes
* its result in the memory locations addressed by the 3 parameters:
* - *cmask will contain the text of the compiled mask
* - *minlen will contain the length of the shortest string that can match
* the mask
* - *charset will contain the minimal set of chars needed to match the mask
* You can pass NULL as *charset and it will be simply not returned, but you
* MUST pass valid pointers for *minlen and *cmask (which must be big enough
* to contain the compiled mask text that is in the worst case as long as the
* text of the mask itself in plaintext format) and the return value of
* matchcomp() will be the number of chars actually written there (excluded
* the trailing zero). cmask can be == mask, matchcomp() can work in place.
* The {cmask, minlen} couple of values make the real compiled mask and
* need to be passed to the functions that use the compiled mask, if you pass
* the wrong minlen or something wrong in cmask to one of these expect a
* coredump. This means that when you record a compiled mask you must store
* *both* these values.
* Once compiled the mask can be used to match a string by means of
* matchexec(), it can be printed back to human-readable format by means
* of sprintmatch() or it can be compared to another compiled mask by means
* of mmexec() that will tell if it completely overrides that mask (a lot like
* what mmatch() does for plain text masks).
* You can gain a lot of speed in many situations avoiding to matchexec() when:
* - The maximum length of the field you are about to match() the mask to is
* shorter than minlen, in example when matching abc*def*ghil with a nick:
* It just cannot match since a nick is at most 9 chars long and the mask
* needs at least 10 chars (10 will be the value returned in minlen).
* - The charset allowed for the field you are about to match to doesn't
* "contain" the charset returned by matchcomp(), in example when you
* have *.* as mask it makes no sense to try to match it against a nick
* because, again, a nick can't contain a '.', you can check this with
* a simple (charset & NTL_IRCNK) in this case.
* - As a special case, since compiled masks are forced to lowercase,
* it would make no sense to use the NTL_LOWER and NTL_UPPER on a compiled
* mask, thus they are reused as follows: if the NTL_LOWER bit of charset
* is set it means that the mask contains only non-wilds chars (i.e. you can
* use strCasecmp() to match it or a direct hash lookup), if the NTL_UPPER
* bit is set it means that it contains only wild chars (and you can
* match it with strlen(field)>=minlen).
* Do these optimizations ONLY when the data you are about to pass to
* matchexec() are *known* to be invalid in advance, using strChattr()
* or strlen() on the text would be slower than calling matchexec() directly
* and let it fail.
* Internally a compiled mask contain in the *cmask area the text of
* the plain text form of the mask itself with applied the following hacks:
* - All characters are forced to lowercase (so that uppercase letters and
* specifically the symbols 'A' and 'Z' are reserved for special use)
* - All non-escaped stars '*' are replaced by the letter 'Z'
* - All non-escaped question marks '?' are replaced by the letter 'A'
* - All escape characters are removed, the wilds escaped by them are
* then passed by without the escape since they don't collide anymore
* with the real wilds (encoded as A/Z)
* - Finally the part of the mask that follows the last asterisk is
* reversed (byte order mirroring) and moved right after the first
* asterisk.
* After all this a mask like: Head*CHUNK1*chu\*nK2*ch??k3*TaIl
* .... becomes: headZliatZchunk1Zchu*nk2ZchAAk3
* This can still be printed on a console, more or less understood by an
* human and handled with the usual str*() library functions.
* When you store somewhere the compiled mask you can avoid storing the
* textform of it since it can be "decompiled" by means of sprintmatch(),
* but at that time the following things are changed in the mask:
* - All chars have been forced to lowercase.
* - The mask is collapsed.
* The balance point of using compiled masks in terms of CPU is when you expect
* to use matchexec() instead of match() at least 20 times on the same mask
* or when you expect to use mmexec() instead of mmatch() 3 times.
*/
/** Compile a mask for faster matching.
* See also @ref compiledmasks.
* @param[out] cmask Output buffer for compiled mask.
* @param[out] minlen Minimum length of matching strings.
* @param[out] charset Character attributes used in compiled mask.
* @param[out] mask Input mask.
* @return Length of compiled mask, not including NUL terminator.
*/
int matchcomp(char *cmask, int *minlen, int *charset, const char *mask)
{
const char *m = mask;
char *b = cmask;
char *fs = 0;
char *ls = 0;
char *x1, *x2;
int l1, l2, lmin, loop, sign;
int star = 0;
int cnt = 0;
char ch;
int chset = ~0;
int chset2 = (NTL_LOWER | NTL_UPPER);
if (m)
while ((ch = *m++))
switch (ch)
{
case '*':
star = 1;
break;
case '?':
cnt++;
*b++ = 'A';
chset2 &= ~NTL_LOWER;
break;
case '\\':
if ((*m == '?') || (*m == '*'))
ch = *m++;
default:
if (star)
{
ls = b;
fs = fs ? fs : b;
*b++ = 'Z';
chset2 &= ~NTL_LOWER;
star = 0;
};
cnt++;
*b = ToLower(ch);
chset &= IRCD_CharAttrTab[*b++ - CHAR_MIN];
chset2 &= ~NTL_UPPER;
};
if (charset)
*charset = (chset | chset2);
if (star)
{
ls = b;
fs = (fs ? fs : b);
*b++ = 'Z';
};
if (ls)
{
for (x1 = ls + 1, x2 = (b - 1); x1 < x2; x1++, x2--)
{
ch = *x1;
*x1 = *x2;
*x2 = ch;
};
l1 = (ls - fs);
l2 = (b - ls);
x1 = fs;
while ((lmin = (l1 < l2) ? l1 : l2))
{
x2 = x1 + l1;
for (loop = 0; loop < lmin; loop++)
{
ch = x1[loop];
x1[loop] = x2[loop];
x2[loop] = ch;
};
x1 += lmin;
sign = l1 - l2;
l1 -= (sign < 0) ? 0 : lmin;
l2 -= (sign > 0) ? 0 : lmin;
};
};
*b = '\0';
*minlen = cnt;
return (b - cmask);
}
/** Compare a string to a compiled mask.
* If \a cmask is not from matchcomp(), or if \a minlen is not the value
* passed out of matchcomp(), this may core.
* See also @ref compiledmasks.
* @param[in] string String to test.
* @param[in] cmask Compiled mask string.
* @param[in] minlen Minimum length of strings that match \a cmask.
* @return Zero if the string matches, non-zero otherwise.
*/
int matchexec(const char *string, const char *cmask, int minlen)
{
const char *s = string - 1;
const char *b = cmask - 1;
int trash;
const char *bb, *bs;
char ch;
tryhead:
while ((ToLower(*++s) == *++b) && *s);
if (!*s)
return ((*b != '\0') && ((*b++ != 'Z') || (*b != '\0')));
if (*b != 'Z')
{
if (*b == 'A')
goto tryhead;
return 1;
};
bs = s;
while (*++s);
if ((trash = (s - string - minlen)) < 0)
return 2;
trytail:
while ((ToLower(*--s) == *++b) && *b && (ToLower(*--s) == *++b) && *b
&& (ToLower(*--s) == *++b) && *b && (ToLower(*--s) == *++b) && *b);
if (*b != 'Z')
{
if (*b == 'A')
goto trytail;
return (*b != '\0');
};
s = --bs;
bb = b;
while ((ch = *++b))
{
while ((ToLower(*++s) != ch))
if (--trash < 0)
return 4;
bs = s;
trychunk:
while ((ToLower(*++s) == *++b) && *b);
if (!*b)
return 0;
if (*b == 'Z')
{
bs = --s;
bb = b;
continue;
};
if (*b == 'A')
goto trychunk;
b = bb;
s = bs;
if (--trash < 0)
return 5;
};
return 0;
}
/*
* matchdecomp()
* Prints the human readable version of *cmask into *mask, (decompiles
* cmask).
* The area pointed by *mask MUST be big enough (the mask might be up to
* twice the size of its compiled form if it's made all of \? or \*, and
* this function can NOT work in place since it might inflate the mask)
* The printed mask is not identical to the one that was compiled to cmask,
* in fact it is 1) forced to all lowercase, 2) collapsed, both things
* are supposed to NOT change it's meaning.
* It returns the number of chars actually written to *mask;
*/
/** Decompile a compiled mask into printable form.
* See also @ref compiledmasks.
* @param[out] mask Output mask buffer.
* @param[in] cmask Compiled mask.
* @return Number of characters written to \a mask.
*/
int matchdecomp(char *mask, const char *cmask)
{
char *rtb = mask;
const char *rcm = cmask;
const char *begtail, *endtail;
if (rtb ==0)
return (-1);
if (rcm == 0)
return (-2);
for (; (*rcm != 'Z'); rcm++, rtb++)
{
if ((*rcm == '?') || (*rcm == '*'))
*rtb++ = '\\';
if (!((*rtb = ((*rcm == 'A') ? '?' : *rcm))))
return (rtb - mask);
};
begtail = rcm++;
*rtb++ = '*';
while (*rcm && (*rcm != 'Z'))
rcm++;
endtail = rcm;
if (*rcm)
{
while (*++rcm)
switch (*rcm)
{
case 'A':
*rtb++ = '?';
break;
case 'Z':
*rtb++ = '*';
break;
case '*':
case '?':
*rtb++ = '\\';
default:
*rtb++ = *rcm;
};
*rtb++ = '*';
};
for (rcm = endtail; (--rcm) > begtail; *rtb++ = ((*rcm == 'A') ? '?' : *rcm))
if ((*rcm == '?') || (*rcm == '*'))
*rtb++ = '\\';
*rtb = '\0';
return (rtb - mask);
}
/*
* mmexec()
* Checks if a wider compiled mask (wcm/wminlen) completely overrides
* a more restrict one (rcm/rminlen), basically what mmatch() does for
* non-compiled masks, returns 0 if the override is true (like mmatch()).
* "the wider overrides the restrict" means that any string that matches
* the restrict one _will_ also match the wider one, always.
* In this we behave differently from mmatch() because in example we return
* true for " a?*cd overrides a*bcd " for which the override happens for how
* we literally defined it, here mmatch() would have returned false.
* The original concepts and the base algorithm are copied from mmatch()
* written by Run (Carlo Wood), this function is written by
* Nemesi (Andrea Cocito)
*/
/** Tests for a superset relationship between compiled masks. This
* function does for compiled masks what mmatch() is does for normal
* masks.
* See also @ref compiledmasks.
* @param[in] wcm Compiled mask believed to be wider.
* @param[in] wminlen Minimum match length for \a wcm.
* @param[in] rcm Compiled mask believed to be restricted.
* @param[in] rminlen Minimum match length for \a rcm.
* @return Zero if \a wcm is a superset of \a rcm, non-zero if not.
*/
int mmexec(const char *wcm, int wminlen, const char *rcm, int rminlen)
{
const char *w, *r, *br, *bw, *rx, *rz;
int eat, trash;
/* First of all rm must have enough non-stars to 'contain' wm */
if ((trash = rminlen - wminlen) < 0)
return 1;
w = wcm;
r = rcm;
eat = 0;
/* Let's start the game, remember that '*' is mapped to 'Z', '?'
is mapped to 'A' and that head?*??*?chunk*???*tail becomes
headAAAAZliatAAAZchunk for compiled masks */
/* Match the head of wm with the head of rm */
for (; (*r) && (*r != 'Z') && ((*w == *r) || (*w == 'A')); r++, w++);
if (*r == 'Z')
while (*w == 'A') /* Eat extra '?' before '*' in wm if got '*' in rm */
w++, eat++;
if (*w != 'Z') /* head1<any>.. can't match head2<any>.. */
return ((*w) || (*r)) ? 1 : 0; /* and head<nul> matches only head<nul> */
if (!*++w)
return 0; /* headZ<nul> matches head<anything> */
/* Does rm have any stars in it ? let's check */
for (rx = r; *r && (*r != 'Z'); r++);
if (!*r)
{
/* rm has no stars and thus isn't a mask but it's just a flat
string: special handling occurs here, note that eat must be 0 here */
/* match the tail */
if (*w != 'Z')
{
for (; r--, (*w) && ((*w == *r) || (*w == 'A')); w++);
if (*w != 'Z') /* headZliat1<any> fails on head<any>2tail */
return (*w) ? 1 : 0; /* but headZliat<nul> matches head<any>tail */
}
/* match the chunks */
while (1)
{ /* This loop can't break but only return */
for (bw = w++; (*w != *rx); rx++) /* Seek the 1st char of the chunk */
if (--trash < 0) /* See if we can trash one more char of rm */
return 1; /* If not we can only fail of course */
for (r = ++rx, w++; (*w) && ((*w == *r) || (*w == 'A')); r++, w++);
if (!*w) /* Did last loop match the rest of chunk ? */
return 0; /* ... Yes, end of wm, matched ! */
if (*w != 'Z')
{ /* ... No, hit non-star */
w = bw; /* Rollback at beginning of chunk */
if (--trash < 0) /* Trashed the char where this try started */
return 1; /* if we can't trash more chars fail */
}
else
{
rx = r; /* Successfully matched a chunk, move rx */
} /* and go on with the next one */
}
}
/* rm has at least one '*' and thus is a 'real' mask */
rz = r++; /* rx = unused of head, rz = beg-tail */
/* Match the tail of wm (if any) against the tail of rm */
if (*w != 'Z')
{
for (; (*w) && (*r != 'Z') && ((*w == *r) || (*w == 'A')); w++, r++);
if (*r == 'Z') /* extra '?' before tail are fluff, just flush 'em */
while (*w == 'A')
w++;
if (*w != 'Z') /* We aren't matching a chunk, can't rollback */
return (*w) ? 1 : 0;
}
/* Match the chunks of wm against what remains of the head of rm */
while (1)
{
bw = w;
for (bw++; (rx < rz) && (*bw != *rx); rx++) /* Seek the first */
if (--trash < 0) /* waste some trash reserve */
return 1;
if (!(rx < rz)) /* head finished */
break;
for (bw++, (br = ++rx);
(br < rz) && (*bw) && ((*bw == *br) || (*bw == 'A')); br++, bw++);
if (!(br < rz)) /* Note that we didn't use any 'eat' char yet, if */
while (*bw == 'A') /* there were eat-en chars the head would be over */
bw++, eat++; /* Happens only at end of head, and eat is still 0 */
if (!*bw)
return 0;
if (*bw != 'Z')
{
eat = 0;
if (!(br < rz))
{ /* If we failed because we got the end of head */
trash -= (br - rx); /* it makes no sense to rollback, just trash */
if (--trash < 0) /* all the rest of the head which isn't long */
return 1; /* enough for this chunk and go out of this */
break; /* loop, then we try with the chunks of rm */
};
if (--trash < 0)
return 1;
}
else
{
w = bw;
rx = br;
}
}
/* Match the unused chunks of wm against the chunks of rm */
rx = r;
for (; *r && (*r != 'Z'); r++);
rz = r;
if (*r++)
{
while (*r)
{
bw = w;
while (eat && *r) /* the '?' we ate makes us skip as many chars */
if (*r++ != 'Z') /* here, but can't skip stars or trailing zero */
eat--;
for (bw++; (*r) && (*bw != *r); r++)
if ((*r != 'Z') && (--trash < 0))
return 1;
if (!*r)
break;
for ((br = ++r), bw++;
(*br) && (*br != 'Z') && ((*bw == *br) || (*bw == 'A')); br++, bw++);
if (*br == 'Z')
while (*bw == 'A')
bw++, eat++;
if (!*bw)
return 0;
if (*bw != 'Z')
{
eat = 0;
if ((!*br) || (*r == 'Z'))
{ /* If we hit the end of rm or a star in it */
trash -= (br - r); /* makes no sense to rollback within this */
if (trash < 0) /* same chunk of br, skip it all and then */
return 1; /* either rollback or break this loop if */
if (!*br) /* it was the end of rm */
break;
r = br;
}
if (--trash < 0)
return 1;
}
else
{
r = br;
w = bw;
}
}
}
/* match the remaining chunks of wm against what remains of the tail of rm */
r = rz - eat - 1; /* can't have <nul> or 'Z' within the tail, so just move r */
while (r >= rx)
{
bw = w;
for (bw++; (*bw != *r); r--)
if (--trash < 0)
return 1;
if (!(r >= rx))
return 1;
for ((br = --r), bw++;
(*bw) && (br >= rx) && ((*bw == *br) || (*bw == 'A')); br--, bw++);
if (!*bw)
return 0;
if (!(br >= rx))
return 1;
if (*bw != 'Z')
{
if (--trash < 0)
return 1;
}
else
{
r = br;
w = bw;
}
}
return 1; /* Auch... something left out ? Fail */
}
/** Test whether an address matches the most significant bits of a mask.
* @param[in] addr Address to test.
* @param[in] mask Address to test against.
* @param[in] bits Number of bits to test.
* @return 0 on mismatch, 1 if bits <= 128 and all bits match; -1 if
* bits > 128 and all bits match.
*/
int ipmask_check(const struct irc_in_addr *addr, const struct irc_in_addr *mask, unsigned char bits)
{
int k;
for (k = 0; k < 8; k++) {
if (bits < 16)
return !(htons(addr->in6_16[k] ^ mask->in6_16[k]) >> (16-bits));
if (addr->in6_16[k] != mask->in6_16[k])
return 0;
if (!(bits -= 16))
return 1;
}
return -1;
}
struct irc_in_addr ipmask_clean(struct irc_in_addr *mask, unsigned char bits)
{
int k;
struct irc_in_addr res;
for (k = 0; k < 8; k++) {
res.in6_16[k] = mask->in6_16[k];
if (bits == 0)
res.in6_16[k] = 0;
if (bits < 16) {
res.in6_16[k] = ntohs((htons(mask->in6_16[k]) >> (16-bits)) << (16-bits));
bits = 0;
}
if (bits >= 16)
bits -= 16;
}
return res;
}