--- /dev/null
+#include <linux/module.h>
+#include <linux/glob.h>
+
+/*
+ * The only reason this code can be compiled as a module is because the
+ * ATA code that depends on it can be as well. In practice, they're
+ * both usually compiled in and the module overhead goes away.
+ */
+MODULE_DESCRIPTION("glob(7) matching");
+MODULE_LICENSE("Dual MIT/GPL");
+
+/**
+ * glob_match - Shell-style pattern matching, like !fnmatch(pat, str, 0)
+ * @pat: Shell-style pattern to match, e.g. "*.[ch]".
+ * @str: String to match. The pattern must match the entire string.
+ *
+ * Perform shell-style glob matching, returning true (1) if the match
+ * succeeds, or false (0) if it fails. Equivalent to !fnmatch(@pat, @str, 0).
+ *
+ * Pattern metacharacters are ?, *, [ and \.
+ * (And, inside character classes, !, - and ].)
+ *
+ * This is small and simple implementation intended for device blacklists
+ * where a string is matched against a number of patterns. Thus, it
+ * does not preprocess the patterns. It is non-recursive, and run-time
+ * is at most quadratic: strlen(@str)*strlen(@pat).
+ *
+ * An example of the worst case is glob_match("*aaaaa", "aaaaaaaaaa");
+ * it takes 6 passes over the pattern before matching the string.
+ *
+ * Like !fnmatch(@pat, @str, 0) and unlike the shell, this does NOT
+ * treat / or leading . specially; it isn't actually used for pathnames.
+ *
+ * Note that according to glob(7) (and unlike bash), character classes
+ * are complemented by a leading !; this does not support the regex-style
+ * [^a-z] syntax.
+ *
+ * An opening bracket without a matching close is matched literally.
+ */
+bool __pure glob_match(char const *pat, char const *str)
+{
+ /*
+ * Backtrack to previous * on mismatch and retry starting one
+ * character later in the string. Because * matches all characters
+ * (no exception for /), it can be easily proved that there's
+ * never a need to backtrack multiple levels.
+ */
+ char const *back_pat = NULL, *back_str = back_str;
+
+ /*
+ * Loop over each token (character or class) in pat, matching
+ * it against the remaining unmatched tail of str. Return false
+ * on mismatch, or true after matching the trailing nul bytes.
+ */
+ for (;;) {
+ unsigned char c = *str++;
+ unsigned char d = *pat++;
+
+ switch (d) {
+ case '?': /* Wildcard: anything but nul */
+ if (c == '\0')
+ return false;
+ break;
+ case '*': /* Any-length wildcard */
+ if (*pat == '\0') /* Optimize trailing * case */
+ return true;
+ back_pat = pat;
+ back_str = --str; /* Allow zero-length match */
+ break;
+ case '[': { /* Character class */
+ bool match = false, inverted = (*pat == '!');
+ char const *class = pat + inverted;
+ unsigned char a = *class++;
+
+ /*
+ * Iterate over each span in the character class.
+ * A span is either a single character a, or a
+ * range a-b. The first span may begin with ']'.
+ */
+ do {
+ unsigned char b = a;
+
+ if (a == '\0') /* Malformed */
+ goto literal;
+
+ if (class[0] == '-' && class[1] != ']') {
+ b = class[1];
+
+ if (b == '\0')
+ goto literal;
+
+ class += 2;
+ /* Any special action if a > b? */
+ }
+ match |= (a <= c && c <= b);
+ } while ((a = *class++) != ']');
+
+ if (match == inverted)
+ goto backtrack;
+ pat = class;
+ }
+ break;
+ case '\\':
+ d = *pat++;
+ /*FALLTHROUGH*/
+ default: /* Literal character */
+literal:
+ if (c == d) {
+ if (d == '\0')
+ return true;
+ break;
+ }
+backtrack:
+ if (c == '\0' || !back_pat)
+ return false; /* No point continuing */
+ /* Try again from last *, one character later in str. */
+ pat = back_pat;
+ str = ++back_str;
+ break;
+ }
+ }
+}
+EXPORT_SYMBOL(glob_match);
+
+
+#ifdef CONFIG_GLOB_SELFTEST
+
+#include <linux/printk.h>
+#include <linux/moduleparam.h>
+
+/* Boot with "glob.verbose=1" to show successful tests, too */
+static bool verbose = false;
+module_param(verbose, bool, 0);
+
+struct glob_test {
+ char const *pat, *str;
+ bool expected;
+};
+
+static bool __pure __init test(char const *pat, char const *str, bool expected)
+{
+ bool match = glob_match(pat, str);
+ bool success = match == expected;
+
+ /* Can't get string literals into a particular section, so... */
+ static char const msg_error[] __initconst =
+ KERN_ERR "glob: \"%s\" vs. \"%s\": %s *** ERROR ***\n";
+ static char const msg_ok[] __initconst =
+ KERN_DEBUG "glob: \"%s\" vs. \"%s\": %s OK\n";
+ static char const mismatch[] __initconst = "mismatch";
+ char const *message;
+
+ if (!success)
+ message = msg_error;
+ else if (verbose)
+ message = msg_ok;
+ else
+ return success;
+
+ printk(message, pat, str, mismatch + 3*match);
+ return success;
+}
+
+/*
+ * The tests are all jammed together in one array to make it simpler
+ * to place that array in the .init.rodata section. The obvious
+ * "array of structures containing char *" has no way to force the
+ * pointed-to strings to be in a particular section.
+ *
+ * Anyway, a test consists of:
+ * 1. Expected glob_match result: '1' or '0'.
+ * 2. Pattern to match: null-terminated string
+ * 3. String to match against: null-terminated string
+ *
+ * The list of tests is terminated with a final '\0' instead of
+ * a glob_match result character.
+ */
+static char const glob_tests[] __initconst =
+ /* Some basic tests */
+ "1" "a\0" "a\0"
+ "0" "a\0" "b\0"
+ "0" "a\0" "aa\0"
+ "0" "a\0" "\0"
+ "1" "\0" "\0"
+ "0" "\0" "a\0"
+ /* Simple character class tests */
+ "1" "[a]\0" "a\0"
+ "0" "[a]\0" "b\0"
+ "0" "[!a]\0" "a\0"
+ "1" "[!a]\0" "b\0"
+ "1" "[ab]\0" "a\0"
+ "1" "[ab]\0" "b\0"
+ "0" "[ab]\0" "c\0"
+ "1" "[!ab]\0" "c\0"
+ "1" "[a-c]\0" "b\0"
+ "0" "[a-c]\0" "d\0"
+ /* Corner cases in character class parsing */
+ "1" "[a-c-e-g]\0" "-\0"
+ "0" "[a-c-e-g]\0" "d\0"
+ "1" "[a-c-e-g]\0" "f\0"
+ "1" "[]a-ceg-ik[]\0" "a\0"
+ "1" "[]a-ceg-ik[]\0" "]\0"
+ "1" "[]a-ceg-ik[]\0" "[\0"
+ "1" "[]a-ceg-ik[]\0" "h\0"
+ "0" "[]a-ceg-ik[]\0" "f\0"
+ "0" "[!]a-ceg-ik[]\0" "h\0"
+ "0" "[!]a-ceg-ik[]\0" "]\0"
+ "1" "[!]a-ceg-ik[]\0" "f\0"
+ /* Simple wild cards */
+ "1" "?\0" "a\0"
+ "0" "?\0" "aa\0"
+ "0" "??\0" "a\0"
+ "1" "?x?\0" "axb\0"
+ "0" "?x?\0" "abx\0"
+ "0" "?x?\0" "xab\0"
+ /* Asterisk wild cards (backtracking) */
+ "0" "*??\0" "a\0"
+ "1" "*??\0" "ab\0"
+ "1" "*??\0" "abc\0"
+ "1" "*??\0" "abcd\0"
+ "0" "??*\0" "a\0"
+ "1" "??*\0" "ab\0"
+ "1" "??*\0" "abc\0"
+ "1" "??*\0" "abcd\0"
+ "0" "?*?\0" "a\0"
+ "1" "?*?\0" "ab\0"
+ "1" "?*?\0" "abc\0"
+ "1" "?*?\0" "abcd\0"
+ "1" "*b\0" "b\0"
+ "1" "*b\0" "ab\0"
+ "0" "*b\0" "ba\0"
+ "1" "*b\0" "bb\0"
+ "1" "*b\0" "abb\0"
+ "1" "*b\0" "bab\0"
+ "1" "*bc\0" "abbc\0"
+ "1" "*bc\0" "bc\0"
+ "1" "*bc\0" "bbc\0"
+ "1" "*bc\0" "bcbc\0"
+ /* Multiple asterisks (complex backtracking) */
+ "1" "*ac*\0" "abacadaeafag\0"
+ "1" "*ac*ae*ag*\0" "abacadaeafag\0"
+ "1" "*a*b*[bc]*[ef]*g*\0" "abacadaeafag\0"
+ "0" "*a*b*[ef]*[cd]*g*\0" "abacadaeafag\0"
+ "1" "*abcd*\0" "abcabcabcabcdefg\0"
+ "1" "*ab*cd*\0" "abcabcabcabcdefg\0"
+ "1" "*abcd*abcdef*\0" "abcabcdabcdeabcdefg\0"
+ "0" "*abcd*\0" "abcabcabcabcefg\0"
+ "0" "*ab*cd*\0" "abcabcabcabcefg\0";
+
+static int __init glob_init(void)
+{
+ unsigned successes = 0;
+ unsigned n = 0;
+ char const *p = glob_tests;
+ static char const message[] __initconst =
+ KERN_INFO "glob: %u self-tests passed, %u failed\n";
+
+ /*
+ * Tests are jammed together in a string. The first byte is '1'
+ * or '0' to indicate the expected outcome, or '\0' to indicate the
+ * end of the tests. Then come two null-terminated strings: the
+ * pattern and the string to match it against.
+ */
+ while (*p) {
+ bool expected = *p++ & 1;
+ char const *pat = p;
+
+ p += strlen(p) + 1;
+ successes += test(pat, p, expected);
+ p += strlen(p) + 1;
+ n++;
+ }
+
+ n -= successes;
+ printk(message, successes, n);
+
+ /* What's the errno for "kernel bug detected"? Guess... */
+ return n ? -ECANCELED : 0;
+}
+
+/* We need a dummy exit function to allow unload */
+static void __exit glob_fini(void) { }
+
+module_init(glob_init);
+module_exit(glob_fini);
+
+#endif /* CONFIG_GLOB_SELFTEST */
Code Review / kvmfornfv.git / blobdiff