boot: Add efi_fnmatch

Unlike MetaiMatch from the UEFI spec/EDK2 this implementation is
intended to be compatible with POSIX fnmatch.

diff --git a/src/boot/efi/efi-string.c b/src/boot/efi/efi-string.c
index 4b405155a03975097bc8425925dfa27c8f88da04..505830e310b9b2a5be2a72d758feb259dd232d5f 100644 (file)
--- a/src/boot/efi/efi-string.c
+++ b/src/boot/efi/efi-string.c
@@ -139,6 +139,111 @@ DEFINE_STRCHR(char16_t, strchr16);
 DEFINE_STRNDUP(char, xstrndup8, strnlen8);
 DEFINE_STRNDUP(char16_t, xstrndup16, strnlen16);
 
+/* Patterns are fnmatch-compatible (with reduced feature support). */
+static bool efi_fnmatch_internal(const char16_t *p, const char16_t *h, int max_depth) {
+        assert(p);
+        assert(h);
+
+        if (max_depth == 0)
+                return false;
+
+        for (;; p++, h++)
+                switch (*p) {
+                case '\0':
+                        /* End of pattern. Check that haystack is now empty. */
+                        return *h == '\0';
+
+                case '\\':
+                        p++;
+                        if (*p == '\0' || *p != *h)
+                                /* Trailing escape or no match. */
+                                return false;
+                        break;
+
+                case '?':
+                        if (*h == '\0')
+                                /* Early end of haystack. */
+                                return false;
+                        break;
+
+                case '*':
+                        /* No need to recurse for consecutive '*'. */
+                        while (*p == '*')
+                                p++;
+
+                        do {
+                                /* Try matching haystack with remaining pattern. */
+                                if (efi_fnmatch_internal(p, h, max_depth - 1))
+                                        return true;
+
+                                /* Otherwise, we match one char here. */
+                                h++;
+                        } while (*h != '\0');
+
+                        /* End of haystack. Pattern needs to be empty too for a match. */
+                        return *p == '\0';
+
+                case '[':
+                        if (*h == '\0')
+                                /* Early end of haystack. */
+                                return false;
+
+                        bool first = true, can_range = true, match = false;
+                        for (;; first = false) {
+                                p++;
+                                if (*p == '\0')
+                                        return false;
+
+                                if (*p == '\\') {
+                                        p++;
+                                        if (*p == '\0')
+                                                return false;
+                                        match |= *p == *h;
+                                        can_range = true;
+                                        continue;
+                                }
+
+                                /* End of set unless it's the first char. */
+                                if (*p == ']' && !first)
+                                        break;
+
+                                /* Range pattern if '-' is not first or last in set. */
+                                if (*p == '-' && can_range && !first && *(p + 1) != ']') {
+                                        char16_t low = *(p - 1);
+                                        p++;
+                                        if (*p == '\\')
+                                                p++;
+                                        if (*p == '\0')
+                                                return false;
+
+                                        if (low <= *h && *h <= *p)
+                                                match = true;
+
+                                        /* Ranges cannot be chained: [a-c-f] == [-abcf] */
+                                        can_range = false;
+                                        continue;
+                                }
+
+                                if (*p == *h)
+                                        match = true;
+                                can_range = true;
+                        }
+
+                        if (!match)
+                                return false;
+                        break;
+
+                default:
+                        if (*p != *h)
+                                /* Single char mismatch. */
+                                return false;
+                }
+}
+
+bool efi_fnmatch(const char16_t *pattern, const char16_t *haystack) {
+        return efi_fnmatch_internal(pattern, haystack, 32);
+}
+
 int efi_memcmp(const void *p1, const void *p2, size_t n) {
         const uint8_t *up1 = p1, *up2 = p2;
         int r;

diff --git a/src/boot/efi/efi-string.h b/src/boot/efi/efi-string.h
index b4870975bcba1a2888cd596ef5c20129cff7bf95..55c9c6e47ad7224b2e2abee91ae6da956641511f 100644 (file)
--- a/src/boot/efi/efi-string.h
+++ b/src/boot/efi/efi-string.h
@@ -99,6 +99,8 @@ static inline char16_t *xstrdup16(const char16_t *s) {
         return xstrndup16(s, SIZE_MAX);
 }
 
+bool efi_fnmatch(const char16_t *pattern, const char16_t *haystack);
+
 #ifdef SD_BOOT
 /* The compiler normally has knowledge about standard functions such as memcmp, but this is not the case when
  * compiling with -ffreestanding. By referring to builtins, the compiler can check arguments and do

diff --git a/src/boot/efi/test-efi-string.c b/src/boot/efi/test-efi-string.c
index b688c6ae4101168f54ddf728ca6db7c53eaa8cc0..5aaa1f713fd43b2a5b4fcb25ecf95d3a3ec1c4fe 100644 (file)
--- a/src/boot/efi/test-efi-string.c
+++ b/src/boot/efi/test-efi-string.c
@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+#include <fnmatch.h>
+
 #include "efi-string.h"
 #include "tests.h"
 
@@ -322,6 +324,52 @@ TEST(xstrdup16) {
         free(s);
 }
 
+#define TEST_FNMATCH_ONE(pattern, haystack, expect)                                     \
+        ({                                                                              \
+                assert_se(fnmatch(pattern, haystack, 0) == (expect ? 0 : FNM_NOMATCH)); \
+                assert_se(efi_fnmatch(u##pattern, u##haystack) == expect);              \
+        })
+
+TEST(efi_fnmatch) {
+        TEST_FNMATCH_ONE("", "", true);
+        TEST_FNMATCH_ONE("abc", "abc", true);
+        TEST_FNMATCH_ONE("aBc", "abc", false);
+        TEST_FNMATCH_ONE("b", "a", false);
+        TEST_FNMATCH_ONE("b", "", false);
+        TEST_FNMATCH_ONE("abc", "a", false);
+        TEST_FNMATCH_ONE("a?c", "azc", true);
+        TEST_FNMATCH_ONE("???", "?.9", true);
+        TEST_FNMATCH_ONE("1?", "1", false);
+        TEST_FNMATCH_ONE("***", "", true);
+        TEST_FNMATCH_ONE("*", "123", true);
+        TEST_FNMATCH_ONE("**", "abcd", true);
+        TEST_FNMATCH_ONE("*b*", "abcd", true);
+        TEST_FNMATCH_ONE("*.conf", "arch.conf", true);
+        TEST_FNMATCH_ONE("debian-*.conf", "debian-wheezy.conf", true);
+        TEST_FNMATCH_ONE("debian-*.*", "debian-wheezy.efi", true);
+        TEST_FNMATCH_ONE("ab*cde", "abzcd", false);
+        TEST_FNMATCH_ONE("\\*\\a\\[", "*a[", true);
+        TEST_FNMATCH_ONE("[abc] [abc] [abc]", "a b c", true);
+        TEST_FNMATCH_ONE("abc]", "abc]", true);
+        TEST_FNMATCH_ONE("[abc]", "z", false);
+        TEST_FNMATCH_ONE("[abc", "a", false);
+        TEST_FNMATCH_ONE("[][!] [][!] [][!]", "[ ] !", true);
+        TEST_FNMATCH_ONE("[]-] []-]", "] -", true);
+        TEST_FNMATCH_ONE("[1\\]] [1\\]]", "1 ]", true);
+        TEST_FNMATCH_ONE("[$-\\+]", "&", true);
+        TEST_FNMATCH_ONE("[1-3A-C] [1-3A-C]", "2 B", true);
+        TEST_FNMATCH_ONE("[3-5] [3-5] [3-5]", "3 4 5", true);
+        TEST_FNMATCH_ONE("[f-h] [f-h] [f-h]", "f g h", true);
+        TEST_FNMATCH_ONE("[a-c-f] [a-c-f] [a-c-f] [a-c-f] [a-c-f]", "a b c - f", true);
+        TEST_FNMATCH_ONE("[a-c-f]", "e", false);
+        TEST_FNMATCH_ONE("[--0] [--0] [--0]", "- . 0", true);
+        TEST_FNMATCH_ONE("[+--] [+--] [+--]", "+ , -", true);
+        TEST_FNMATCH_ONE("[f-l]", "m", false);
+        TEST_FNMATCH_ONE("[b]", "z-a", false);
+        TEST_FNMATCH_ONE("[a\\-z]", "b", false);
+        TEST_FNMATCH_ONE("?a*b[.-0]c", "/a/b/c", true);
+}
+
 TEST(efi_memcmp) {
         assert_se(efi_memcmp(NULL, NULL, 0) == 0);
         assert_se(efi_memcmp(NULL, NULL, 1) == 0);