140 lines
3.5 KiB
C
140 lines
3.5 KiB
C
/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* Simple pattern matching, with '*' and '?' as wildcards.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*/
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#include "includes.h"
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RCSID("$OpenBSD: match.c,v 1.11 2001/01/21 19:05:52 markus Exp $");
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#include "match.h"
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/*
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* Returns true if the given string matches the pattern (which may contain ?
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* and * as wildcards), and zero if it does not match.
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*/
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int
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match_pattern(const char *s, const char *pattern)
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{
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for (;;) {
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/* If at end of pattern, accept if also at end of string. */
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if (!*pattern)
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return !*s;
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if (*pattern == '*') {
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/* Skip the asterisk. */
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pattern++;
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/* If at end of pattern, accept immediately. */
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if (!*pattern)
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return 1;
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/* If next character in pattern is known, optimize. */
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if (*pattern != '?' && *pattern != '*') {
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/*
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* Look instances of the next character in
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* pattern, and try to match starting from
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* those.
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*/
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for (; *s; s++)
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if (*s == *pattern &&
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match_pattern(s + 1, pattern + 1))
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return 1;
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/* Failed. */
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return 0;
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}
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/*
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* Move ahead one character at a time and try to
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* match at each position.
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*/
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for (; *s; s++)
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if (match_pattern(s, pattern))
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return 1;
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/* Failed. */
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return 0;
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}
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/*
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* There must be at least one more character in the string.
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* If we are at the end, fail.
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*/
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if (!*s)
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return 0;
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/* Check if the next character of the string is acceptable. */
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if (*pattern != '?' && *pattern != *s)
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return 0;
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/* Move to the next character, both in string and in pattern. */
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s++;
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pattern++;
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}
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/* NOTREACHED */
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}
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/*
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* Tries to match the host name (which must be in all lowercase) against the
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* comma-separated sequence of subpatterns (each possibly preceded by ! to
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* indicate negation). Returns -1 if negation matches, 1 if there is
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* a positive match, 0 if there is no match at all.
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*/
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int
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match_hostname(const char *host, const char *pattern, u_int len)
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{
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char sub[1024];
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int negated;
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int got_positive;
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u_int i, subi;
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got_positive = 0;
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for (i = 0; i < len;) {
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/* Check if the subpattern is negated. */
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if (pattern[i] == '!') {
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negated = 1;
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i++;
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} else
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negated = 0;
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/*
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* Extract the subpattern up to a comma or end. Convert the
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* subpattern to lowercase.
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*/
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for (subi = 0;
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i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
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subi++, i++)
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sub[subi] = isupper(pattern[i]) ? tolower(pattern[i]) : pattern[i];
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/* If subpattern too long, return failure (no match). */
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if (subi >= sizeof(sub) - 1)
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return 0;
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/* If the subpattern was terminated by a comma, skip the comma. */
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if (i < len && pattern[i] == ',')
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i++;
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/* Null-terminate the subpattern. */
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sub[subi] = '\0';
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/* Try to match the subpattern against the host name. */
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if (match_pattern(host, sub)) {
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if (negated)
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return -1; /* Negative */
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else
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got_positive = 1; /* Positive */
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}
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}
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/*
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* Return success if got a positive match. If there was a negative
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* match, we have already returned -1 and never get here.
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*/
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return got_positive;
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}
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