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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.sbin/httpd/patterns.c	Lines:	0	292	0.0 %
Date:	2017-11-13	Branches:	0	235	0.0 %


/*	$OpenBSD: patterns.c,v 1.5 2016/02/14 18:20:59 semarie Exp $	*/

/*
 * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
 * Copyright (C) 1994-2015 Lua.org, PUC-Rio.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * Derived from Lua 5.3.1:
 * $Id: patterns.c,v 1.5 2016/02/14 18:20:59 semarie Exp $
 * Standard library for string operations and pattern-matching
 */

#include <sys/types.h>
#include <ctype.h>
#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>

#include "patterns.h"

#define uchar(c)	((unsigned char)(c)) /* macro to 'unsign' a char */
#define CAP_UNFINISHED	(-1)
#define CAP_POSITION	(-2)
#define L_ESC		'%'
#define SPECIALS	"^$*+?.([%-"

struct match_state {
	int matchdepth;		/* control for recursive depth (to avoid C
				 * stack overflow) */
	int repetitioncounter;	/* control the repetition items */
	int maxcaptures;	/* configured capture limit */
	const char *src_init;	/* init of source string */
	const char *src_end;	/* end ('\0') of source string */
	const char *p_end;	/* end ('\0') of pattern */
	const char *error;	/* should be NULL */
	int level;		/* total number of captures (finished or
				 * unfinished) */
	struct {
		const char *init;
		ptrdiff_t len;
	} capture[MAXCAPTURES];
};

/* recursive function */
static const char *match(struct match_state *, const char *, const char *);

static int
match_error(struct match_state *ms, const char *error)
{
	ms->error = ms->error == NULL ? error : ms->error;
	return (-1);
}

static int
check_capture(struct match_state *ms, int l)
{
	l -= '1';
	if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED)
		return match_error(ms, "invalid capture index");
	return (l);
}

static int
capture_to_close(struct match_state *ms)
{
	int level = ms->level;
	for (level--; level >= 0; level--)
		if (ms->capture[level].len == CAP_UNFINISHED)
			return (level);
	return match_error(ms, "invalid pattern capture");
}

static const char *
classend(struct match_state *ms, const char *p)
{
	switch (*p++) {
	case L_ESC:
		if (p == ms->p_end)
			match_error(ms,
			    "malformed pattern (ends with '%')");
		return p + 1;
	case '[':
		if (*p == '^')
			p++;
		do {
			/* look for a ']' */
			if (p == ms->p_end) {
				match_error(ms,
				    "malformed pattern (missing ']')");
				break;
			}
			if (*(p++) == L_ESC && p < ms->p_end) {
				/* skip escapes (e.g. '%]') */
				p++;
			}
		} while (*p != ']');
		return p + 1;
	default:
		return p;
	}
}

static int
match_class(int c, int cl)
{
	int res;
	switch (tolower(cl)) {
	case 'a':
		res = isalpha(c);
		break;
	case 'c':
		res = iscntrl(c);
		break;
	case 'd':
		res = isdigit(c);
		break;
	case 'g':
		res = isgraph(c);
		break;
	case 'l':
		res = islower(c);
		break;
	case 'p':
		res = ispunct(c);
		break;
	case 's':
		res = isspace(c);
		break;
	case 'u':
		res = isupper(c);
		break;
	case 'w':
		res = isalnum(c);
		break;
	case 'x':
		res = isxdigit(c);
		break;
	default:
		return (cl == c);
	}
	return (islower(cl) ? res : !res);
}

static int
matchbracketclass(int c, const char *p, const char *ec)
{
	int sig = 1;
	if (*(p + 1) == '^') {
		sig = 0;
		/* skip the '^' */
		p++;
	}
	while (++p < ec) {
		if (*p == L_ESC) {
			p++;
			if (match_class(c, uchar(*p)))
				return sig;
		} else if ((*(p + 1) == '-') && (p + 2 < ec)) {
			p += 2;
			if (uchar(*(p - 2)) <= c && c <= uchar(*p))
				return sig;
		} else if (uchar(*p) == c)
			return sig;
	}
	return !sig;
}

static int
singlematch(struct match_state *ms, const char *s, const char *p,
    const char *ep)
{
	if (s >= ms->src_end)
		return 0;
	else {
		int c = uchar(*s);
		switch (*p) {
		case '.':
			/* matches any char */
			return (1);
		case L_ESC:
			return match_class(c, uchar(*(p + 1)));
		case '[':
			return matchbracketclass(c, p, ep - 1);
		default:
			return (uchar(*p) == c);
		}
	}
}

static const char *
matchbalance(struct match_state *ms, const char *s, const char *p)
{
	if (p >= ms->p_end - 1) {
		match_error(ms,
		    "malformed pattern (missing arguments to '%b')");
		return (NULL);
	}
	if (*s != *p)
		return (NULL);
	else {
		int b = *p;
		int e = *(p + 1);
		int cont = 1;
		while (++s < ms->src_end) {
			if (*s == e) {
				if (--cont == 0)
					return s + 1;
			} else if (*s == b)
				cont++;
		}
	}

	/* string ends out of balance */
	return (NULL);
}

static const char *
max_expand(struct match_state *ms, const char *s, const char *p, const char *ep)
{
	ptrdiff_t i = 0;
	/* counts maximum expand for item */
	while (singlematch(ms, s + i, p, ep))
		i++;
	/* keeps trying to match with the maximum repetitions */
	while (i >= 0) {
		const char *res = match(ms, (s + i), ep + 1);
		if (res)
			return res;
		/* else didn't match; reduce 1 repetition to try again */
		i--;
	}
	return NULL;
}

static const char *
min_expand(struct match_state *ms, const char *s, const char *p, const char *ep)
{
	for (;;) {
		const char *res = match(ms, s, ep + 1);
		if (res != NULL)
			return res;
		else if (singlematch(ms, s, p, ep))
			s++;	/* try with one more repetition */
		else
			return NULL;
	}
}

static const char *
start_capture(struct match_state *ms, const char *s, const char *p, int what)
{
	const char *res;

	int level = ms->level;
	if (level >= ms->maxcaptures) {
		match_error(ms, "too many captures");
		return (NULL);
	}
	ms->capture[level].init = s;
	ms->capture[level].len = what;
	ms->level = level + 1;
	/* undo capture if match failed */
	if ((res = match(ms, s, p)) == NULL)
		ms->level--;
	return res;
}

static const char *
end_capture(struct match_state *ms, const char *s, const char *p)
{
	int l = capture_to_close(ms);
	const char *res;
	if (l == -1)
		return NULL;
	/* close capture */
	ms->capture[l].len = s - ms->capture[l].init;
	/* undo capture if match failed */
	if ((res = match(ms, s, p)) == NULL)
		ms->capture[l].len = CAP_UNFINISHED;
	return res;
}

static const char *
match_capture(struct match_state *ms, const char *s, int l)
{
	size_t len;
	l = check_capture(ms, l);
	if (l == -1)
		return NULL;
	len = ms->capture[l].len;
	if ((size_t) (ms->src_end - s) >= len &&
	    memcmp(ms->capture[l].init, s, len) == 0)
		return s + len;
	else
		return NULL;
}

static const char *
match(struct match_state *ms, const char *s, const char *p)
{
	const char *ep, *res;
	char previous;

	if (ms->matchdepth-- == 0) {
		match_error(ms, "pattern too complex");
		return (NULL);
	}

	/* using goto's to optimize tail recursion */
 init:
	/* end of pattern? */
	if (p != ms->p_end) {
		switch (*p) {
		case '(':
			/* start capture */
			if (*(p + 1) == ')')
				/* position capture? */
				s = start_capture(ms, s, p + 2, CAP_POSITION);
			else
				s = start_capture(ms, s, p + 1, CAP_UNFINISHED);
			break;
		case ')':
			/* end capture */
			s = end_capture(ms, s, p + 1);
			break;
		case '$':
			/* is the '$' the last char in pattern? */
			if ((p + 1) != ms->p_end) {
				/* no; go to default */
				goto dflt;
			}
			 /* check end of string */
			s = (s == ms->src_end) ? s : NULL;
			break;
		case L_ESC:
			/* escaped sequences not in the format class[*+?-]? */
			switch (*(p + 1)) {
			case 'b':
				/* balanced string? */
				s = matchbalance(ms, s, p + 2);
				if (s != NULL) {
					p += 4;
					/* return match(ms, s, p + 4); */
					goto init;
				} /* else fail (s == NULL) */
				break;
			case 'f':
				/* frontier? */
				p += 2;
				if (*p != '[') {
					match_error(ms, "missing '['"
					    " after '%f' in pattern");
					break;
				}
				/* points to what is next */
				ep = classend(ms, p);
				if (ms->error != NULL)
					break;
				previous =
				    (s == ms->src_init) ? '\0' : *(s - 1);
				if (!matchbracketclass(uchar(previous),
				    p, ep - 1) &&
				    matchbracketclass(uchar(*s),
				    p, ep - 1)) {
					p = ep;
					/* return match(ms, s, ep); */
					goto init;
				}
				/* match failed */
				s = NULL;
				break;
			case '0':
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9':
				/* capture results (%0-%9)? */
				s = match_capture(ms, s, uchar(*(p + 1)));
				if (s != NULL) {
					p += 2;
					/* return match(ms, s, p + 2) */
					goto init;
				}
				break;
			default:
				goto dflt;
			}
			break;
		default:

			/* pattern class plus optional suffix */
	dflt:
			/* points to optional suffix */
			ep = classend(ms, p);
			if (ms->error != NULL)
				break;

			/* does not match at least once? */
			if (!singlematch(ms, s, p, ep)) {
				if (ms->repetitioncounter-- == 0) {
					match_error(ms, "max repetition items");
					s = NULL; /* fail */
				/* accept empty? */
				} else if
				    (*ep == '*' || *ep == '?' || *ep == '-') {
					 p = ep + 1;
					/* return match(ms, s, ep + 1); */
					 goto init;
				} else {
					/* '+' or no suffix */
					s = NULL; /* fail */
				}
			} else {
				/* matched once */
				/* handle optional suffix */
				switch (*ep) {
				case '?':
					/* optional */
					if ((res =
					    match(ms, s + 1, ep + 1)) != NULL)
						s = res;
					else {
						/*
						 * else return
						 *     match(ms, s, ep + 1);
						 */
						p = ep + 1;
						goto init;
					}
					break;
				case '+':
					/* 1 or more repetitions */
					s++; /* 1 match already done */
					/* FALLTHROUGH */
				case '*':
					/* 0 or more repetitions */
					s = max_expand(ms, s, p, ep);
					break;
				case '-':
					/* 0 or more repetitions (minimum) */
					s = min_expand(ms, s, p, ep);
					break;
				default:
					/* no suffix */
					s++;
					p = ep;
					/* return match(ms, s + 1, ep); */
					goto init;
				}
			}
			break;
		}
	}
	ms->matchdepth++;
	return s;
}

static const char *
lmemfind(const char *s1, size_t l1,
    const char *s2, size_t l2)
{
	const char *init;

	if (l2 == 0) {
		/* empty strings are everywhere */
		return (s1);
	} else if (l2 > l1) {
		/* avoids a negative 'l1' */
		return (NULL);
	} else {
		/*
		 * to search for a '*s2' inside 's1'
		 * - 1st char will be checked by 'memchr'
		 * - 's2' cannot be found after that
		 */
		l2--;
		l1 = l1 - l2;
		while (l1 > 0 &&
		    (init = (const char *)memchr(s1, *s2, l1)) != NULL) {
			/* 1st char is already checked */
			init++;
			if (memcmp(init, s2 + 1, l2) == 0)
				return init - 1;
			else {
				/* correct 'l1' and 's1' to try again */
				l1 -= init - s1;
				s1 = init;
			}
		}
		/* not found */
		return (NULL);
	}
}

static int
push_onecapture(struct match_state *ms, int i, const char *s,
    const char *e, struct str_find *sm)
{
	if (i >= ms->level) {
		if (i == 0 || ms->level == 0) {
			/* add whole match */
			sm->sm_so = (off_t)(s - ms->src_init);
			sm->sm_eo = (off_t)(e - s) + sm->sm_so;
		} else
			return match_error(ms, "invalid capture index");
	} else {
		ptrdiff_t l = ms->capture[i].len;
		if (l == CAP_UNFINISHED)
			return match_error(ms, "unfinished capture");
		sm->sm_so = ms->capture[i].init - ms->src_init;
		sm->sm_eo = sm->sm_so + l;
	}
	sm->sm_eo = sm->sm_eo < sm->sm_so ? sm->sm_so : sm->sm_eo;
	return (0);
}

static int
push_captures(struct match_state *ms, const char *s, const char *e,
    struct str_find *sm, size_t nsm)
{
	unsigned int i;
	unsigned int nlevels = (ms->level <= 0 && s) ? 1 : ms->level;

	if (nlevels > nsm)
		nlevels = nsm;
	for (i = 0; i < nlevels; i++)
		if (push_onecapture(ms, i, s, e, sm + i) == -1)
			break;

	/* number of strings pushed */
	return (nlevels);
}

/* check whether pattern has no special characters */
static int
nospecials(const char *p, size_t l)
{
	size_t upto = 0;

	do {
		if (strpbrk(p + upto, SPECIALS)) {
			/* pattern has a special character */
			return 0;
		}
		/* may have more after \0 */
		upto += strlen(p + upto) + 1;
	} while (upto <= l);

	/* no special chars found */
	return (1);
}

static int
str_find_aux(struct match_state *ms, const char *pattern, const char *string,
    struct str_find *sm, size_t nsm, off_t init)
{
	size_t		 ls = strlen(string);
	size_t		 lp = strlen(pattern);
	const char	*s = string;
	const char	*p = pattern;
	const char	*s1, *s2;
	int		 anchor, i;

	if (init < 0)
		init = 0;
	else if (init > (off_t)ls)
		return match_error(ms, "starting after string's end");
	s1 = s + init;

	if (nospecials(p, lp)) {
		/* do a plain search */
		s2 = lmemfind(s1, ls - (size_t)init, p, lp);
		if (s2 != NULL) {
			i = 0;
			sm[i].sm_so = 0;
			sm[i].sm_eo = ls;
			if (nsm > 1) {
				i++;
				sm[i].sm_so = s2 - s;
				sm[i].sm_eo = (s2 - s) + lp;
			}
			return (i + 1);
		}
		return (0);
	}

	anchor = (*p == '^');
	if (anchor) {
		p++;
		lp--;	/* skip anchor character */
	}
	ms->maxcaptures = (nsm > MAXCAPTURES ? MAXCAPTURES : nsm) - 1;
	ms->matchdepth = MAXCCALLS;
	ms->repetitioncounter = MAXREPETITION;
	ms->src_init = s;
	ms->src_end = s + ls;
	ms->p_end = p + lp;
	do {
		const char *res;
		ms->level = 0;
		if ((res = match(ms, s1, p)) != NULL) {
			sm->sm_so = 0;
			sm->sm_eo = ls;
			return push_captures(ms, s1, res, sm + 1, nsm - 1) + 1;

		} else if (ms->error != NULL) {
			return 0;
		}
	} while (s1++ < ms->src_end && !anchor);

	return 0;
}

int
str_find(const char *string, const char *pattern, struct str_find *sm,
    size_t nsm, const char **errstr)
{
	struct match_state	ms;
	int			ret;

	memset(&ms, 0, sizeof(ms));
	memset(sm, 0, nsm * sizeof(*sm));

	ret = str_find_aux(&ms, pattern, string, sm, nsm, 0);
	if (ms.error != NULL) {
		/* Return 0 on error and store the error string */
		*errstr = ms.error;
		ret = 0;
	} else
		*errstr = NULL;

	return (ret);
}

int
str_match(const char *string, const char *pattern, struct str_match *m,
    const char **errstr)
{
	struct str_find		 sm[MAXCAPTURES];
	struct match_state	 ms;
	int			 ret, i;
	size_t			 len, nsm;

	nsm = MAXCAPTURES;
	memset(&ms, 0, sizeof(ms));
	memset(sm, 0, sizeof(sm));
	memset(m, 0, sizeof(*m));

	ret = str_find_aux(&ms, pattern, string, sm, nsm, 0);
	if (ret <= 0 || ms.error != NULL) {
		/* Return -1 on error and store the error string */
		*errstr = ms.error;
		return (-1);
	}

	if ((m->sm_match = calloc(ret, sizeof(char *))) == NULL) {
		*errstr = strerror(errno);
		return (-1);
	}
	m->sm_nmatch = ret;

	for (i = 0; i < ret; i++) {
		if (sm[i].sm_so > sm[i].sm_eo)
			continue;
		len = sm[i].sm_eo - sm[i].sm_so;
		if ((m->sm_match[i] = strndup(string +
		    sm[i].sm_so, len)) == NULL) {
			*errstr = strerror(errno);
			str_match_free(m);
			return (-1);
		}
	}

	*errstr = NULL;
	return (0);
}

void
str_match_free(struct str_match *m)
{
	unsigned int	 i = 0;
	for (i = 0; i < m->sm_nmatch; i++)
		free(m->sm_match[i]);
	free(m->sm_match);
	m->sm_match = NULL;
	m->sm_nmatch = 0;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: patterns.c,v 1.5 2016/02/14 18:20:59 semarie Exp $ */
2
3			/*
4			* Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
5			* Copyright (C) 1994-2015 Lua.org, PUC-Rio.
6			*
7			* Permission is hereby granted, free of charge, to any person obtaining
8			* a copy of this software and associated documentation files (the
9			* "Software"), to deal in the Software without restriction, including
10			* without limitation the rights to use, copy, modify, merge, publish,
11			* distribute, sublicense, and/or sell copies of the Software, and to
12			* permit persons to whom the Software is furnished to do so, subject to
13			* the following conditions:
14			*
15			* The above copyright notice and this permission notice shall be
16			* included in all copies or substantial portions of the Software.
17			*
18			* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19			* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20			* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21			* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
22			* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23			* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24			* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25			*/
26
27			/*
28			* Derived from Lua 5.3.1:
29			* $Id: patterns.c,v 1.5 2016/02/14 18:20:59 semarie Exp $
30			* Standard library for string operations and pattern-matching
31			*/
32
33			#include <sys/types.h>
34			#include <ctype.h>
35			#include <errno.h>
36			#include <stddef.h>
37			#include <stdlib.h>
38			#include <string.h>
39
40			#include "patterns.h"
41
42			#define uchar(c) ((unsigned char)(c)) /* macro to 'unsign' a char */
43			#define CAP_UNFINISHED (-1)
44			#define CAP_POSITION (-2)
45			#define L_ESC '%'
46			#define SPECIALS "^$*+?.([%-"
47
48			struct match_state {
49			int matchdepth; /* control for recursive depth (to avoid C
50			* stack overflow) */
51			int repetitioncounter; /* control the repetition items */
52			int maxcaptures; /* configured capture limit */
53			const char src_init; / init of source string */
54			const char src_end; / end ('\0') of source string */
55			const char p_end; / end ('\0') of pattern */
56			const char error; / should be NULL */
57			int level; /* total number of captures (finished or
58			* unfinished) */
59			struct {
60			const char *init;
61			ptrdiff_t len;
62			} capture[MAXCAPTURES];
63			};
64
65			/* recursive function */
66			static const char match(struct match_state , const char , const char );
67
68			static int
69			match_error(struct match_state ms, const char error)
70			{
71			ms->error = ms->error == NULL ? error : ms->error;
72			return (-1);
73			}
74
75			static int
76			check_capture(struct match_state *ms, int l)
77			{
78			l -= '1';
79			if (l < 0 \|\| l >= ms->level \|\| ms->capture[l].len == CAP_UNFINISHED)
80			return match_error(ms, "invalid capture index");
81			return (l);
82			}
83
84			static int
85			capture_to_close(struct match_state *ms)
86			{
87			int level = ms->level;
88			for (level--; level >= 0; level--)
89			if (ms->capture[level].len == CAP_UNFINISHED)
90			return (level);
91			return match_error(ms, "invalid pattern capture");
92			}
93
94			static const char *
95			classend(struct match_state ms, const char p)
96			{
97			switch (*p++) {
98			case L_ESC:
99			if (p == ms->p_end)
100			match_error(ms,
101			"malformed pattern (ends with '%')");
102			return p + 1;
103			case '[':
104			if (*p == '^')
105			p++;
106			do {
107			/* look for a ']' */
108			if (p == ms->p_end) {
109			match_error(ms,
110			"malformed pattern (missing ']')");
111			break;
112			}
113			if (*(p++) == L_ESC && p < ms->p_end) {
114			/* skip escapes (e.g. '%]') */
115			p++;
116			}
117			} while (*p != ']');
118			return p + 1;
119			default:
120			return p;
121			}
122			}
123
124			static int
125			match_class(int c, int cl)
126			{
127			int res;
128			switch (tolower(cl)) {
129			case 'a':
130			res = isalpha(c);
131			break;
132			case 'c':
133			res = iscntrl(c);
134			break;
135			case 'd':
136			res = isdigit(c);
137			break;
138			case 'g':
139			res = isgraph(c);
140			break;
141			case 'l':
142			res = islower(c);
143			break;
144			case 'p':
145			res = ispunct(c);
146			break;
147			case 's':
148			res = isspace(c);
149			break;
150			case 'u':
151			res = isupper(c);
152			break;
153			case 'w':
154			res = isalnum(c);
155			break;
156			case 'x':
157			res = isxdigit(c);
158			break;
159			default:
160			return (cl == c);
161			}
162			return (islower(cl) ? res : !res);
163			}
164
165			static int
166			matchbracketclass(int c, const char p, const char ec)
167			{
168			int sig = 1;
169			if (*(p + 1) == '^') {
170			sig = 0;
171			/* skip the '^' */
172			p++;
173			}
174			while (++p < ec) {
175			if (*p == L_ESC) {
176			p++;
177			if (match_class(c, uchar(*p)))
178			return sig;
179			} else if ((*(p + 1) == '-') && (p + 2 < ec)) {
180			p += 2;
181			if (uchar((p - 2)) <= c && c <= uchar(p))
182			return sig;
183			} else if (uchar(*p) == c)
184			return sig;
185			}
186			return !sig;
187			}
188
189			static int
190			singlematch(struct match_state ms, const char s, const char *p,
191			const char *ep)
192			{
193			if (s >= ms->src_end)
194			return 0;
195			else {
196			int c = uchar(*s);
197			switch (*p) {
198			case '.':
199			/* matches any char */
200			return (1);
201			case L_ESC:
202			return match_class(c, uchar(*(p + 1)));
203			case '[':
204			return matchbracketclass(c, p, ep - 1);
205			default:
206			return (uchar(*p) == c);
207			}
208			}
209			}
210
211			static const char *
212			matchbalance(struct match_state ms, const char s, const char *p)
213			{
214			if (p >= ms->p_end - 1) {
215			match_error(ms,
216			"malformed pattern (missing arguments to '%b')");
217			return (NULL);
218			}
219			if (s != p)
220			return (NULL);
221			else {
222			int b = *p;
223			int e = *(p + 1);
224			int cont = 1;
225			while (++s < ms->src_end) {
226			if (*s == e) {
227			if (--cont == 0)
228			return s + 1;
229			} else if (*s == b)
230			cont++;
231			}
232			}
233
234			/* string ends out of balance */
235			return (NULL);
236			}
237
238			static const char *
239			max_expand(struct match_state ms, const char s, const char p, const char ep)
240			{
241			ptrdiff_t i = 0;
242			/* counts maximum expand for item */
243			while (singlematch(ms, s + i, p, ep))
244			i++;
245			/* keeps trying to match with the maximum repetitions */
246			while (i >= 0) {
247			const char *res = match(ms, (s + i), ep + 1);
248			if (res)
249			return res;
250			/* else didn't match; reduce 1 repetition to try again */
251			i--;
252			}
253			return NULL;
254			}
255
256			static const char *
257			min_expand(struct match_state ms, const char s, const char p, const char ep)
258			{
259			for (;;) {
260			const char *res = match(ms, s, ep + 1);
261			if (res != NULL)
262			return res;
263			else if (singlematch(ms, s, p, ep))
264			s++; /* try with one more repetition */
265			else
266			return NULL;
267			}
268			}
269
270			static const char *
271			start_capture(struct match_state ms, const char s, const char *p, int what)
272			{
273			const char *res;
274
275			int level = ms->level;
276			if (level >= ms->maxcaptures) {
277			match_error(ms, "too many captures");
278			return (NULL);
279			}
280			ms->capture[level].init = s;
281			ms->capture[level].len = what;
282			ms->level = level + 1;
283			/* undo capture if match failed */
284			if ((res = match(ms, s, p)) == NULL)
285			ms->level--;
286			return res;
287			}
288
289			static const char *
290			end_capture(struct match_state ms, const char s, const char *p)
291			{
292			int l = capture_to_close(ms);
293			const char *res;
294			if (l == -1)
295			return NULL;
296			/* close capture */
297			ms->capture[l].len = s - ms->capture[l].init;
298			/* undo capture if match failed */
299			if ((res = match(ms, s, p)) == NULL)
300			ms->capture[l].len = CAP_UNFINISHED;
301			return res;
302			}
303
304			static const char *
305			match_capture(struct match_state ms, const char s, int l)
306			{
307			size_t len;
308			l = check_capture(ms, l);
309			if (l == -1)
310			return NULL;
311			len = ms->capture[l].len;
312			if ((size_t) (ms->src_end - s) >= len &&
313			memcmp(ms->capture[l].init, s, len) == 0)
314			return s + len;
315			else
316			return NULL;
317			}
318
319			static const char *
320			match(struct match_state ms, const char s, const char *p)
321			{
322			const char ep, res;
323			char previous;
324
325			if (ms->matchdepth-- == 0) {
326			match_error(ms, "pattern too complex");
327			return (NULL);
328			}
329
330			/* using goto's to optimize tail recursion */
331			init:
332			/* end of pattern? */
333			if (p != ms->p_end) {
334			switch (*p) {
335			case '(':
336			/* start capture */
337			if (*(p + 1) == ')')
338			/* position capture? */
339			s = start_capture(ms, s, p + 2, CAP_POSITION);
340			else
341			s = start_capture(ms, s, p + 1, CAP_UNFINISHED);
342			break;
343			case ')':
344			/* end capture */
345			s = end_capture(ms, s, p + 1);
346			break;
347			case '$':
348			/* is the '$' the last char in pattern? */
349			if ((p + 1) != ms->p_end) {
350			/* no; go to default */
351			goto dflt;
352			}
353			/* check end of string */
354			s = (s == ms->src_end) ? s : NULL;
355			break;
356			case L_ESC:
357			/* escaped sequences not in the format class[+?-]? /
358			switch (*(p + 1)) {
359			case 'b':
360			/* balanced string? */
361			s = matchbalance(ms, s, p + 2);
362			if (s != NULL) {
363			p += 4;
364			/* return match(ms, s, p + 4); */
365			goto init;
366			} /* else fail (s == NULL) */
367			break;
368			case 'f':
369			/* frontier? */
370			p += 2;
371			if (*p != '[') {
372			match_error(ms, "missing '['"
373			" after '%f' in pattern");
374			break;
375			}
376			/* points to what is next */
377			ep = classend(ms, p);
378			if (ms->error != NULL)
379			break;
380			previous =
381			(s == ms->src_init) ? '\0' : *(s - 1);
382			if (!matchbracketclass(uchar(previous),
383			p, ep - 1) &&
384			matchbracketclass(uchar(*s),
385			p, ep - 1)) {
386			p = ep;
387			/* return match(ms, s, ep); */
388			goto init;
389			}
390			/* match failed */
391			s = NULL;
392			break;
393			case '0':
394			case '1':
395			case '2':
396			case '3':
397			case '4':
398			case '5':
399			case '6':
400			case '7':
401			case '8':
402			case '9':
403			/* capture results (%0-%9)? */
404			s = match_capture(ms, s, uchar(*(p + 1)));
405			if (s != NULL) {
406			p += 2;
407			/* return match(ms, s, p + 2) */
408			goto init;
409			}
410			break;
411			default:
412			goto dflt;
413			}
414			break;
415			default:
416
417			/* pattern class plus optional suffix */
418			dflt:
419			/* points to optional suffix */
420			ep = classend(ms, p);
421			if (ms->error != NULL)
422			break;
423
424			/* does not match at least once? */
425			if (!singlematch(ms, s, p, ep)) {
426			if (ms->repetitioncounter-- == 0) {
427			match_error(ms, "max repetition items");
428			s = NULL; /* fail */
429			/* accept empty? */
430			} else if
431			(ep == '' \|\| ep == '?' \|\| ep == '-') {
432			p = ep + 1;
433			/* return match(ms, s, ep + 1); */
434			goto init;
435			} else {
436			/* '+' or no suffix */
437			s = NULL; /* fail */
438			}
439			} else {
440			/* matched once */
441			/* handle optional suffix */
442			switch (*ep) {
443			case '?':
444			/* optional */
445			if ((res =
446			match(ms, s + 1, ep + 1)) != NULL)
447			s = res;
448			else {
449			/*
450			* else return
451			* match(ms, s, ep + 1);
452			*/
453			p = ep + 1;
454			goto init;
455			}
456			break;
457			case '+':
458			/* 1 or more repetitions */
459			s++; /* 1 match already done */
460			/* FALLTHROUGH */
461			case '*':
462			/* 0 or more repetitions */
463			s = max_expand(ms, s, p, ep);
464			break;
465			case '-':
466			/* 0 or more repetitions (minimum) */
467			s = min_expand(ms, s, p, ep);
468			break;
469			default:
470			/* no suffix */
471			s++;
472			p = ep;
473			/* return match(ms, s + 1, ep); */
474			goto init;
475			}
476			}
477			break;
478			}
479			}
480			ms->matchdepth++;
481			return s;
482			}
483
484			static const char *
485			lmemfind(const char *s1, size_t l1,
486			const char *s2, size_t l2)
487			{
488			const char *init;
489
490			if (l2 == 0) {
491			/* empty strings are everywhere */
492			return (s1);
493			} else if (l2 > l1) {
494			/* avoids a negative 'l1' */
495			return (NULL);
496			} else {
497			/*
498			* to search for a '*s2' inside 's1'
499			* - 1st char will be checked by 'memchr'
500			* - 's2' cannot be found after that
501			*/
502			l2--;
503			l1 = l1 - l2;
504			while (l1 > 0 &&
505			(init = (const char )memchr(s1, s2, l1)) != NULL) {
506			/* 1st char is already checked */
507			init++;
508			if (memcmp(init, s2 + 1, l2) == 0)
509			return init - 1;
510			else {
511			/* correct 'l1' and 's1' to try again */
512			l1 -= init - s1;
513			s1 = init;
514			}
515			}
516			/* not found */
517			return (NULL);
518			}
519			}
520
521			static int
522			push_onecapture(struct match_state ms, int i, const char s,
523			const char e, struct str_find sm)
524			{
525			if (i >= ms->level) {
526			if (i == 0 \|\| ms->level == 0) {
527			/* add whole match */
528			sm->sm_so = (off_t)(s - ms->src_init);
529			sm->sm_eo = (off_t)(e - s) + sm->sm_so;
530			} else
531			return match_error(ms, "invalid capture index");
532			} else {
533			ptrdiff_t l = ms->capture[i].len;
534			if (l == CAP_UNFINISHED)
535			return match_error(ms, "unfinished capture");
536			sm->sm_so = ms->capture[i].init - ms->src_init;
537			sm->sm_eo = sm->sm_so + l;
538			}
539			sm->sm_eo = sm->sm_eo < sm->sm_so ? sm->sm_so : sm->sm_eo;
540			return (0);
541			}
542
543			static int
544			push_captures(struct match_state ms, const char s, const char *e,
545			struct str_find *sm, size_t nsm)
546			{
547			unsigned int i;
548			unsigned int nlevels = (ms->level <= 0 && s) ? 1 : ms->level;
549
550			if (nlevels > nsm)
551			nlevels = nsm;
552			for (i = 0; i < nlevels; i++)
553			if (push_onecapture(ms, i, s, e, sm + i) == -1)
554			break;
555
556			/* number of strings pushed */
557			return (nlevels);
558			}
559
560			/* check whether pattern has no special characters */
561			static int
562			nospecials(const char *p, size_t l)
563			{
564			size_t upto = 0;
565
566			do {
567			if (strpbrk(p + upto, SPECIALS)) {
568			/* pattern has a special character */
569			return 0;
570			}
571			/* may have more after \0 */
572			upto += strlen(p + upto) + 1;
573			} while (upto <= l);
574
575			/* no special chars found */
576			return (1);
577			}
578
579			static int
580			str_find_aux(struct match_state ms, const char pattern, const char *string,
581			struct str_find *sm, size_t nsm, off_t init)
582			{
583			size_t ls = strlen(string);
584			size_t lp = strlen(pattern);
585			const char *s = string;
586			const char *p = pattern;
587			const char s1, s2;
588			int anchor, i;
589
590			if (init < 0)
591			init = 0;
592			else if (init > (off_t)ls)
593			return match_error(ms, "starting after string's end");
594			s1 = s + init;
595
596			if (nospecials(p, lp)) {
597			/* do a plain search */
598			s2 = lmemfind(s1, ls - (size_t)init, p, lp);
599			if (s2 != NULL) {
600			i = 0;
601			sm[i].sm_so = 0;
602			sm[i].sm_eo = ls;
603			if (nsm > 1) {
604			i++;
605			sm[i].sm_so = s2 - s;
606			sm[i].sm_eo = (s2 - s) + lp;
607			}
608			return (i + 1);
609			}
610			return (0);
611			}
612
613			anchor = (*p == '^');
614			if (anchor) {
615			p++;
616			lp--; /* skip anchor character */
617			}
618			ms->maxcaptures = (nsm > MAXCAPTURES ? MAXCAPTURES : nsm) - 1;
619			ms->matchdepth = MAXCCALLS;
620			ms->repetitioncounter = MAXREPETITION;
621			ms->src_init = s;
622			ms->src_end = s + ls;
623			ms->p_end = p + lp;
624			do {
625			const char *res;
626			ms->level = 0;
627			if ((res = match(ms, s1, p)) != NULL) {
628			sm->sm_so = 0;
629			sm->sm_eo = ls;
630			return push_captures(ms, s1, res, sm + 1, nsm - 1) + 1;
631
632			} else if (ms->error != NULL) {
633			return 0;
634			}
635			} while (s1++ < ms->src_end && !anchor);
636
637			return 0;
638			}
639
640			int
641			str_find(const char string, const char pattern, struct str_find *sm,
642			size_t nsm, const char **errstr)
643			{
644			struct match_state ms;
645			int ret;
646
647			memset(&ms, 0, sizeof(ms));
648			memset(sm, 0, nsm * sizeof(*sm));
649
650			ret = str_find_aux(&ms, pattern, string, sm, nsm, 0);
651			if (ms.error != NULL) {
652			/* Return 0 on error and store the error string */
653			*errstr = ms.error;
654			ret = 0;
655			} else
656			*errstr = NULL;
657
658			return (ret);
659			}
660
661			int
662			str_match(const char string, const char pattern, struct str_match *m,
663			const char **errstr)
664			{
665			struct str_find sm[MAXCAPTURES];
666			struct match_state ms;
667			int ret, i;
668			size_t len, nsm;
669
670			nsm = MAXCAPTURES;
671			memset(&ms, 0, sizeof(ms));
672			memset(sm, 0, sizeof(sm));
673			memset(m, 0, sizeof(*m));
674
675			ret = str_find_aux(&ms, pattern, string, sm, nsm, 0);
676			if (ret <= 0 \|\| ms.error != NULL) {
677			/* Return -1 on error and store the error string */
678			*errstr = ms.error;
679			return (-1);
680			}
681
682			if ((m->sm_match = calloc(ret, sizeof(char *))) == NULL) {
683			*errstr = strerror(errno);
684			return (-1);
685			}
686			m->sm_nmatch = ret;
687
688			for (i = 0; i < ret; i++) {
689			if (sm[i].sm_so > sm[i].sm_eo)
690			continue;
691			len = sm[i].sm_eo - sm[i].sm_so;
692			if ((m->sm_match[i] = strndup(string +
693			sm[i].sm_so, len)) == NULL) {
694			*errstr = strerror(errno);
695			str_match_free(m);
696			return (-1);
697			}
698			}
699
700			*errstr = NULL;
701			return (0);
702			}
703
704			void
705			str_match_free(struct str_match *m)
706			{
707			unsigned int i = 0;
708			for (i = 0; i < m->sm_nmatch; i++)
709			free(m->sm_match[i]);
710			free(m->sm_match);
711			m->sm_match = NULL;
712			m->sm_nmatch = 0;
713			}