From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 15 Jul 2024 16:18:35 +0000 (+0200)
Subject: efivars: add helper that reads an fs path from an efi var
X-Git-Tag: v257-rc1~433^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c8d60ae79d1763c6ef16fdb306b65d909a769de8;p=thirdparty%2Fsystemd.git

efivars: add helper that reads an fs path from an efi var
---

diff --git a/src/basic/efivars.c b/src/basic/efivars.c
index 8470d085c77..0ff07fa1133 100644
--- a/src/basic/efivars.c
+++ b/src/basic/efivars.c
@@ -145,8 +145,10 @@ int efi_get_variable(
 int efi_get_variable_string(const char *variable, char **ret) {
         _cleanup_free_ void *s = NULL;
         size_t ss = 0;
-        int r;
         char *x;
+        int r;
+
+        assert(variable);
 
         r = efi_get_variable(variable, NULL, &s, &ss);
         if (r < 0)
@@ -156,10 +158,27 @@ int efi_get_variable_string(const char *variable, char **ret) {
         if (!x)
                 return -ENOMEM;
 
-        *ret = x;
+        if (ret)
+                *ret = x;
+
         return 0;
 }
 
+int efi_get_variable_path(const char *variable, char **ret) {
+        int r;
+
+        assert(variable);
+
+        r = efi_get_variable_string(variable, ret);
+        if (r < 0)
+                return r;
+
+        if (ret)
+                efi_tilt_backslashes(*ret);
+
+        return r;
+}
+
 static int efi_verify_variable(const char *variable, uint32_t attr, const void *value, size_t size) {
         _cleanup_free_ void *buf = NULL;
         size_t n;
diff --git a/src/basic/efivars.h b/src/basic/efivars.h
index 34d697fbff4..fe2be3107a0 100644
--- a/src/basic/efivars.h
+++ b/src/basic/efivars.h
@@ -11,6 +11,7 @@
 #include "sd-id128.h"
 
 #include "efivars-fundamental.h"
+#include "string-util.h"
 #include "time-util.h"
 
 #define EFI_VENDOR_LOADER       SD_ID128_MAKE(4a,67,b0,82,0a,4c,41,cf,b6,c7,44,0b,29,bb,8c,4f)
@@ -47,6 +48,7 @@
 
 int efi_get_variable(const char *variable, uint32_t *attribute, void **ret_value, size_t *ret_size);
 int efi_get_variable_string(const char *variable, char **ret);
+int efi_get_variable_path(const char *variable, char **ret);
 int efi_set_variable(const char *variable, const void *value, size_t size);
 int efi_set_variable_string(const char *variable, const char *p);
 
@@ -68,6 +70,10 @@ static inline int efi_get_variable_string(const char *variable, char **ret) {
         return -EOPNOTSUPP;
 }
 
+static inline int efi_get_variable_path(const char *variable, char **ret) {
+        return -EOPNOTSUPP;
+}
+
 static inline int efi_set_variable(const char *variable, const void *value, size_t size) {
         return -EOPNOTSUPP;
 }
@@ -100,3 +106,7 @@ static inline int systemd_efi_options_efivarfs_if_newer(char **line) {
         return -ENODATA;
 }
 #endif
+
+static inline char *efi_tilt_backslashes(char *s) {
+        return string_replace_char(s, '\\', '/');
+}
diff --git a/src/boot/bless-boot.c b/src/boot/bless-boot.c
index f86d102f0be..4853aaefe9a 100644
--- a/src/boot/bless-boot.c
+++ b/src/boot/bless-boot.c
@@ -219,14 +219,12 @@ static int acquire_boot_count_path(
         uint64_t left, done;
         int r;
 
-        r = efi_get_variable_string(EFI_LOADER_VARIABLE(LoaderBootCountPath), &path);
+        r = efi_get_variable_path(EFI_LOADER_VARIABLE(LoaderBootCountPath), &path);
         if (r == -ENOENT)
                 return -EUNATCH; /* in this case, let the caller print a message */
         if (r < 0)
                 return log_error_errno(r, "Failed to read LoaderBootCountPath EFI variable: %m");
 
-        efi_tilt_backslashes(path);
-
         if (!path_is_normalized(path))
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "Path read from LoaderBootCountPath is not normalized, refusing: %s",
diff --git a/src/boot/bootctl-status.c b/src/boot/bootctl-status.c
index c8ab363de59..8e5462f5480 100644
--- a/src/boot/bootctl-status.c
+++ b/src/boot/bootctl-status.c
@@ -298,12 +298,24 @@ fail:
         return r;
 }
 
-static void read_efi_var(const char *variable, char **ret) {
+static int efi_get_variable_string_and_warn(const char *variable, char **ret) {
         int r;
 
         r = efi_get_variable_string(variable, ret);
         if (r < 0 && r != -ENOENT)
-                log_warning_errno(r, "Failed to read EFI variable '%s', ignoring: %m", variable);
+                return log_warning_errno(r, "Failed to read EFI variable '%s', ignoring: %m", variable);
+
+        return r;
+}
+
+static int efi_get_variable_path_and_warn(const char *variable, char **ret) {
+        int r;
+
+        r = efi_get_variable_path(variable, ret);
+        if (r < 0 && r != -ENOENT)
+                return log_warning_errno(r, "Failed to read EFI variable '%s', ignoring: %m", variable);
+
+        return r;
 }
 
 static void print_yes_no_line(bool first, bool good, const char *name) {
@@ -401,20 +413,15 @@ int verb_status(int argc, char *argv[], void *userdata) {
                 Tpm2Support s;
                 int have;
 
-                read_efi_var(EFI_LOADER_VARIABLE(LoaderFirmwareType), &fw_type);
-                read_efi_var(EFI_LOADER_VARIABLE(LoaderFirmwareInfo), &fw_info);
-                read_efi_var(EFI_LOADER_VARIABLE(LoaderInfo), &loader);
-                read_efi_var(EFI_LOADER_VARIABLE(StubInfo), &stub);
-                read_efi_var(EFI_LOADER_VARIABLE(LoaderImageIdentifier), &loader_path);
-                read_efi_var(EFI_LOADER_VARIABLE(StubImageIdentifier), &stub_path);
+                (void) efi_get_variable_string_and_warn(EFI_LOADER_VARIABLE(LoaderFirmwareType), &fw_type);
+                (void) efi_get_variable_string_and_warn(EFI_LOADER_VARIABLE(LoaderFirmwareInfo), &fw_info);
+                (void) efi_get_variable_string_and_warn(EFI_LOADER_VARIABLE(LoaderInfo), &loader);
+                (void) efi_get_variable_string_and_warn(EFI_LOADER_VARIABLE(StubInfo), &stub);
+                (void) efi_get_variable_path_and_warn(EFI_LOADER_VARIABLE(LoaderImageIdentifier), &loader_path);
+                (void) efi_get_variable_path_and_warn(EFI_LOADER_VARIABLE(StubImageIdentifier), &stub_path);
                 (void) efi_loader_get_features(&loader_features);
                 (void) efi_stub_get_features(&stub_features);
 
-                if (loader_path)
-                        efi_tilt_backslashes(loader_path);
-                if (stub_path)
-                        efi_tilt_backslashes(stub_path);
-
                 SecureBootMode secure = efi_get_secure_boot_mode();
                 printf("%sSystem:%s\n", ansi_underline(), ansi_normal());
                 printf("      Firmware: %s%s (%s)%s\n", ansi_highlight(), strna(fw_type), strna(fw_info), ansi_normal());
diff --git a/src/shared/efi-api.h b/src/shared/efi-api.h
index 09071b22c99..61ef91df9fb 100644
--- a/src/shared/efi-api.h
+++ b/src/shared/efi-api.h
@@ -66,9 +66,5 @@ static inline bool efi_has_tpm2(void) {
 
 #endif
 
-static inline char *efi_tilt_backslashes(char *s) {
-        return string_replace_char(s, '\\', '/');
-}
-
 sd_id128_t efi_guid_to_id128(const void *guid);
 void efi_id128_to_guid(sd_id128_t id, void *ret_guid);