2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * Simple pattern matching, with '*' and '?' as wildcards.
7 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
15 RCSID("$OpenBSD: match.c,v 1.11 2001/01/21 19:05:52 markus Exp $");
20 * Returns true if the given string matches the pattern (which may contain ?
21 * and * as wildcards), and zero if it does not match.
25 match_pattern(const char *s, const char *pattern)
28 /* If at end of pattern, accept if also at end of string. */
32 if (*pattern == '*') {
33 /* Skip the asterisk. */
36 /* If at end of pattern, accept immediately. */
40 /* If next character in pattern is known, optimize. */
41 if (*pattern != '?' && *pattern != '*') {
43 * Look instances of the next character in
44 * pattern, and try to match starting from
49 match_pattern(s + 1, pattern + 1))
55 * Move ahead one character at a time and try to
56 * match at each position.
59 if (match_pattern(s, pattern))
65 * There must be at least one more character in the string.
66 * If we are at the end, fail.
71 /* Check if the next character of the string is acceptable. */
72 if (*pattern != '?' && *pattern != *s)
75 /* Move to the next character, both in string and in pattern. */
83 * Tries to match the host name (which must be in all lowercase) against the
84 * comma-separated sequence of subpatterns (each possibly preceded by ! to
85 * indicate negation). Returns -1 if negation matches, 1 if there is
86 * a positive match, 0 if there is no match at all.
90 match_hostname(const char *host, const char *pattern, u_int len)
98 for (i = 0; i < len;) {
99 /* Check if the subpattern is negated. */
100 if (pattern[i] == '!') {
107 * Extract the subpattern up to a comma or end. Convert the
108 * subpattern to lowercase.
111 i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
113 sub[subi] = isupper(pattern[i]) ? tolower(pattern[i]) : pattern[i];
114 /* If subpattern too long, return failure (no match). */
115 if (subi >= sizeof(sub) - 1)
118 /* If the subpattern was terminated by a comma, skip the comma. */
119 if (i < len && pattern[i] == ',')
122 /* Null-terminate the subpattern. */
125 /* Try to match the subpattern against the host name. */
126 if (match_pattern(host, sub)) {
128 return -1; /* Negative */
130 got_positive = 1; /* Positive */
135 * Return success if got a positive match. If there was a negative
136 * match, we have already returned -1 and never get here.