From 3684d9be497c5cb5164435238b970931c93b41e6 Mon Sep 17 00:00:00 2001
From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Mon, 30 Jan 2023 16:25:23 +0100
Subject: [PATCH] efi-string: Add startswith8()

startswith() from string-util-fundamental.h is defined for sd_char
which is char16_t, so let's add an implementation for char as well.

(cherry picked from commit ad36d31ea578622883c3b5297c971374096a504a)

Related: RHEL-16952
---
 src/boot/efi/efi-string.c      | 15 +++++++++++++++
 src/boot/efi/efi-string.h      |  2 ++
 src/boot/efi/test-efi-string.c | 12 ++++++++++++
 3 files changed, 29 insertions(+)

diff --git a/src/boot/efi/efi-string.c b/src/boot/efi/efi-string.c
index cf0d71e986..6b84af69e6 100644
--- a/src/boot/efi/efi-string.c
+++ b/src/boot/efi/efi-string.c
@@ -216,6 +216,21 @@ char16_t *xstrn8_to_16(const char *str8, size_t n) {
         return str16;
 }
 
+char *startswith8(const char *s, const char *prefix) {
+        size_t l;
+
+        assert(prefix);
+
+        if (!s)
+                return NULL;
+
+        l = strlen8(prefix);
+        if (!strneq8(s, prefix, l))
+                return NULL;
+
+        return (char*) s + l;
+}
+
 static bool efi_fnmatch_prefix(const char16_t *p, const char16_t *h, const char16_t **ret_p, const char16_t **ret_h) {
         assert(p);
         assert(h);
diff --git a/src/boot/efi/efi-string.h b/src/boot/efi/efi-string.h
index 2a28db3593..477229bf60 100644
--- a/src/boot/efi/efi-string.h
+++ b/src/boot/efi/efi-string.h
@@ -105,6 +105,8 @@ static inline char16_t *xstr8_to_16(const char *str8) {
         return xstrn8_to_16(str8, strlen8(str8));
 }
 
+char *startswith8(const char *s, const char *prefix);
+
 bool efi_fnmatch(const char16_t *pattern, const char16_t *haystack);
 
 bool parse_number8(const char *s, uint64_t *ret_u, const char **ret_tail);
diff --git a/src/boot/efi/test-efi-string.c b/src/boot/efi/test-efi-string.c
index c7e42c7b94..be7f8f9b1c 100644
--- a/src/boot/efi/test-efi-string.c
+++ b/src/boot/efi/test-efi-string.c
@@ -355,6 +355,18 @@ TEST(xstrn8_to_16) {
         free(s);
 }
 
+TEST(startswith8) {
+        assert_se(streq8(startswith8("", ""), ""));
+        assert_se(streq8(startswith8("x", ""), "x"));
+        assert_se(!startswith8("", "x"));
+        assert_se(!startswith8("", "xxxxxxxx"));
+        assert_se(streq8(startswith8("xxx", "x"), "xx"));
+        assert_se(streq8(startswith8("xxx", "xx"), "x"));
+        assert_se(streq8(startswith8("xxx", "xxx"), ""));
+        assert_se(!startswith8("xxx", "xxxx"));
+        assert_se(!startswith8(NULL, ""));
+}
+
 #define TEST_FNMATCH_ONE(pattern, haystack, expect)                                     \
         ({                                                                              \
                 assert_se(fnmatch(pattern, haystack, 0) == (expect ? 0 : FNM_NOMATCH)); \