1 files changed, 287 insertions, 0 deletions
diff --git a/lib/glob.c b/lib/glob.c
new file mode 100644
index 000000000000..500fc80d23e1
--- /dev/null
+++ b/lib/glob.c
@@ -0,0 +1,287 @@
+#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 */

diff --git a/lib/glob.c b/lib/glob.c new file mode 100644 index 000000000000..500fc80d23e1 --- /dev/null +++ b/lib/glob.c
@@ -0,0 +1,287 @@
	1	#include <linux/module.h>
	2	#include <linux/glob.h>
	3
	4	/*
	5	* The only reason this code can be compiled as a module is because the
	6	* ATA code that depends on it can be as well. In practice, they're
	7	* both usually compiled in and the module overhead goes away.
	8	*/
	9	MODULE_DESCRIPTION("glob(7) matching");
	10	MODULE_LICENSE("Dual MIT/GPL");
	11
	12	/**
	13	* glob_match - Shell-style pattern matching, like !fnmatch(pat, str, 0)
	14	* @pat: Shell-style pattern to match, e.g. "*.[ch]".
	15	* @str: String to match. The pattern must match the entire string.
	16	*
	17	* Perform shell-style glob matching, returning true (1) if the match
	18	* succeeds, or false (0) if it fails. Equivalent to !fnmatch(@pat, @str, 0).
	19	*
	20	* Pattern metacharacters are ?, *, [ and \.
	21	* (And, inside character classes, !, - and ].)
	22	*
	23	* This is small and simple implementation intended for device blacklists
	24	* where a string is matched against a number of patterns. Thus, it
	25	* does not preprocess the patterns. It is non-recursive, and run-time
	26	* is at most quadratic: strlen(@str)*strlen(@pat).
	27	*
	28	* An example of the worst case is glob_match("*aaaaa", "aaaaaaaaaa");
	29	* it takes 6 passes over the pattern before matching the string.
	30	*
	31	* Like !fnmatch(@pat, @str, 0) and unlike the shell, this does NOT
	32	* treat / or leading . specially; it isn't actually used for pathnames.
	33	*
	34	* Note that according to glob(7) (and unlike bash), character classes
	35	* are complemented by a leading !; this does not support the regex-style
	36	* [^a-z] syntax.
	37	*
	38	* An opening bracket without a matching close is matched literally.
	39	*/
	40	bool __pure glob_match(char const pat, char const str)
	41	{
	42	/*
	43	* Backtrack to previous * on mismatch and retry starting one
	44	* character later in the string. Because * matches all characters
	45	* (no exception for /), it can be easily proved that there's
	46	* never a need to backtrack multiple levels.
	47	*/
	48	char const back_pat = NULL, back_str = back_str;
	49
	50	/*
	51	* Loop over each token (character or class) in pat, matching
	52	* it against the remaining unmatched tail of str. Return false
	53	* on mismatch, or true after matching the trailing nul bytes.
	54	*/
	55	for (;;) {
	56	unsigned char c = *str++;
	57	unsigned char d = *pat++;
	58
	59	switch (d) {
	60	case '?': /* Wildcard: anything but nul */
	61	if (c == '\0')
	62	return false;
	63	break;
	64	case '': / Any-length wildcard */
	65	if (pat == '\0') / Optimize trailing * case */
	66	return true;
	67	back_pat = pat;
	68	back_str = --str; /* Allow zero-length match */
	69	break;
	70	case '[': { /* Character class */
	71	bool match = false, inverted = (*pat == '!');
	72	char const *class = pat + inverted;
	73	unsigned char a = *class++;
	74
	75	/*
	76	* Iterate over each span in the character class.
	77	* A span is either a single character a, or a
	78	* range a-b. The first span may begin with ']'.
	79	*/
	80	do {
	81	unsigned char b = a;
	82
	83	if (a == '\0') /* Malformed */
	84	goto literal;
	85
	86	if (class[0] == '-' && class[1] != ']') {
	87	b = class[1];
	88
	89	if (b == '\0')
	90	goto literal;
	91
	92	class += 2;
	93	/* Any special action if a > b? */
	94	}
	95	match \|= (a <= c && c <= b);
	96	} while ((a = *class++) != ']');
	97
	98	if (match == inverted)
	99	goto backtrack;
	100	pat = class;
	101	}
	102	break;
	103	case '\\':
	104	d = *pat++;
	105	/FALLTHROUGH/
	106	default: /* Literal character */
	107	literal:
	108	if (c == d) {
	109	if (d == '\0')
	110	return true;
	111	break;
	112	}
	113	backtrack:
	114	if (c == '\0' \|\| !back_pat)
	115	return false; /* No point continuing */
	116	/* Try again from last , one character later in str. /
	117	pat = back_pat;
	118	str = ++back_str;
	119	break;
	120	}
	121	}
	122	}
	123	EXPORT_SYMBOL(glob_match);
	124
	125
	126	#ifdef CONFIG_GLOB_SELFTEST
	127
	128	#include <linux/printk.h>
	129	#include <linux/moduleparam.h>
	130
	131	/* Boot with "glob.verbose=1" to show successful tests, too */
	132	static bool verbose = false;
	133	module_param(verbose, bool, 0);
	134
	135	struct glob_test {
	136	char const pat, str;
	137	bool expected;
	138	};
	139
	140	static bool __pure __init test(char const pat, char const str, bool expected)
	141	{
	142	bool match = glob_match(pat, str);
	143	bool success = match == expected;
	144
	145	/* Can't get string literals into a particular section, so... */
	146	static char const msg_error[] __initconst =
	147	KERN_ERR "glob: \"%s\" vs. \"%s\": %s * ERROR *\n";
	148	static char const msg_ok[] __initconst =
	149	KERN_DEBUG "glob: \"%s\" vs. \"%s\": %s OK\n";
	150	static char const mismatch[] __initconst = "mismatch";
	151	char const *message;
	152
	153	if (!success)
	154	message = msg_error;
	155	else if (verbose)
	156	message = msg_ok;
	157	else
	158	return success;
	159
	160	printk(message, pat, str, mismatch + 3*match);
	161	return success;
	162	}
	163
	164	/*
	165	* The tests are all jammed together in one array to make it simpler
	166	* to place that array in the .init.rodata section. The obvious
	167	* "array of structures containing char *" has no way to force the
	168	* pointed-to strings to be in a particular section.
	169	*
	170	* Anyway, a test consists of:
	171	* 1. Expected glob_match result: '1' or '0'.
	172	* 2. Pattern to match: null-terminated string
	173	* 3. String to match against: null-terminated string
	174	*
	175	* The list of tests is terminated with a final '\0' instead of
	176	* a glob_match result character.
	177	*/
	178	static char const glob_tests[] __initconst =
	179	/* Some basic tests */
	180	"1" "a\0" "a\0"
	181	"0" "a\0" "b\0"
	182	"0" "a\0" "aa\0"
	183	"0" "a\0" "\0"
	184	"1" "\0" "\0"
	185	"0" "\0" "a\0"
	186	/* Simple character class tests */
	187	"1" "[a]\0" "a\0"
	188	"0" "[a]\0" "b\0"
	189	"0" "[!a]\0" "a\0"
	190	"1" "[!a]\0" "b\0"
	191	"1" "[ab]\0" "a\0"
	192	"1" "[ab]\0" "b\0"
	193	"0" "[ab]\0" "c\0"
	194	"1" "[!ab]\0" "c\0"
	195	"1" "[a-c]\0" "b\0"
	196	"0" "[a-c]\0" "d\0"
	197	/* Corner cases in character class parsing */
	198	"1" "[a-c-e-g]\0" "-\0"
	199	"0" "[a-c-e-g]\0" "d\0"
	200	"1" "[a-c-e-g]\0" "f\0"
	201	"1" "[]a-ceg-ik[]\0" "a\0"
	202	"1" "[]a-ceg-ik[]\0" "]\0"
	203	"1" "[]a-ceg-ik[]\0" "[\0"
	204	"1" "[]a-ceg-ik[]\0" "h\0"
	205	"0" "[]a-ceg-ik[]\0" "f\0"
	206	"0" "[!]a-ceg-ik[]\0" "h\0"
	207	"0" "[!]a-ceg-ik[]\0" "]\0"
	208	"1" "[!]a-ceg-ik[]\0" "f\0"
	209	/* Simple wild cards */
	210	"1" "?\0" "a\0"
	211	"0" "?\0" "aa\0"
	212	"0" "??\0" "a\0"
	213	"1" "?x?\0" "axb\0"
	214	"0" "?x?\0" "abx\0"
	215	"0" "?x?\0" "xab\0"
	216	/* Asterisk wild cards (backtracking) */
	217	"0" "*??\0" "a\0"
	218	"1" "*??\0" "ab\0"
	219	"1" "*??\0" "abc\0"
	220	"1" "*??\0" "abcd\0"
	221	"0" "??*\0" "a\0"
	222	"1" "??*\0" "ab\0"
	223	"1" "??*\0" "abc\0"
	224	"1" "??*\0" "abcd\0"
	225	"0" "?*?\0" "a\0"
	226	"1" "?*?\0" "ab\0"
	227	"1" "?*?\0" "abc\0"
	228	"1" "?*?\0" "abcd\0"
	229	"1" "*b\0" "b\0"
	230	"1" "*b\0" "ab\0"
	231	"0" "*b\0" "ba\0"
	232	"1" "*b\0" "bb\0"
	233	"1" "*b\0" "abb\0"
	234	"1" "*b\0" "bab\0"
	235	"1" "*bc\0" "abbc\0"
	236	"1" "*bc\0" "bc\0"
	237	"1" "*bc\0" "bbc\0"
	238	"1" "*bc\0" "bcbc\0"
	239	/* Multiple asterisks (complex backtracking) */
	240	"1" "ac\0" "abacadaeafag\0"
	241	"1" "acaeag\0" "abacadaeafag\0"
	242	"1" "ab[bc][ef]g\0" "abacadaeafag\0"
	243	"0" "ab[ef][cd]g\0" "abacadaeafag\0"
	244	"1" "abcd\0" "abcabcabcabcdefg\0"
	245	"1" "abcd*\0" "abcabcabcabcdefg\0"
	246	"1" "abcdabcdef*\0" "abcabcdabcdeabcdefg\0"
	247	"0" "abcd\0" "abcabcabcabcefg\0"
	248	"0" "abcd*\0" "abcabcabcabcefg\0";
	249
	250	static int __init glob_init(void)
	251	{
	252	unsigned successes = 0;
	253	unsigned n = 0;
	254	char const *p = glob_tests;
	255	static char const message[] __initconst =
	256	KERN_INFO "glob: %u self-tests passed, %u failed\n";
	257
	258	/*
	259	* Tests are jammed together in a string. The first byte is '1'
	260	* or '0' to indicate the expected outcome, or '\0' to indicate the
	261	* end of the tests. Then come two null-terminated strings: the
	262	* pattern and the string to match it against.
	263	*/
	264	while (*p) {
	265	bool expected = *p++ & 1;
	266	char const *pat = p;
	267
	268	p += strlen(p) + 1;
	269	successes += test(pat, p, expected);
	270	p += strlen(p) + 1;
	271	n++;
	272	}
	273
	274	n -= successes;
	275	printk(message, successes, n);
	276
	277	/* What's the errno for "kernel bug detected"? Guess... */
	278	return n ? -ECANCELED : 0;
	279	}
	280
	281	/* We need a dummy exit function to allow unload */
	282	static void __exit glob_fini(void) { }
	283
	284	module_init(glob_init);
	285	module_exit(glob_fini);
	286
	287	#endif /* CONFIG_GLOB_SELFTEST */