Provide better error message when MokManager is not found

Makefile

@@ -38,10 +38,10 @@ CFLAGS += -DENABLE_SHIM_CERT
 else
 TARGETS += $(MMNAME) $(FBNAME)
 endif
-OBJS	= shim.o globals.o mok.o netboot.o cert.o replacements.o tpm.o version.o errlog.o sbat.o sbat_data.o sbat_var.o pe.o pe-relocate.o httpboot.o csv.o load-options.o
+OBJS	= shim.o globals.o mok.o netboot.o cert.o dp.o replacements.o tpm.o version.o errlog.o sbat.o sbat_data.o sbat_var.o pe.o pe-relocate.o httpboot.o csv.o load-options.o
 KEYS	= shim_cert.h ocsp.* ca.* shim.crt shim.csr shim.p12 shim.pem shim.key shim.cer
-ORIG_SOURCES	= shim.c globals.c mok.c netboot.c replacements.c tpm.c errlog.c sbat.c pe.c pe-relocate.c httpboot.c shim.h version.h $(wildcard include/*.h) cert.S sbat_var.S
-MOK_OBJS = MokManager.o PasswordCrypt.o crypt_blowfish.o errlog.o sbat_data.o globals.o
+ORIG_SOURCES	= shim.c globals.c mok.c netboot.c dp.c replacements.c tpm.c errlog.c sbat.c pe.c pe-relocate.c httpboot.c shim.h version.h $(wildcard include/*.h) cert.S sbat_var.S
+MOK_OBJS = MokManager.o PasswordCrypt.o crypt_blowfish.o errlog.o sbat_data.o globals.o dp.o
 ORIG_MOK_SOURCES = MokManager.c PasswordCrypt.c crypt_blowfish.c shim.h $(wildcard include/*.h)
 FALLBACK_OBJS = fallback.o tpm.o errlog.o sbat_data.o globals.o
 ORIG_FALLBACK_SRCS = fallback.c

dp.c

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+/*
+ * dp.c - device path helpers
+ * Copyright Peter Jones <[email protected]>
+ */
+
+#include "shim.h"
+
+int
+is_removable_media_path(EFI_LOADED_IMAGE *li)
+{
+	unsigned int pathlen = 0;
+	CHAR16 *bootpath = NULL;
+	int ret = 0;
+
+	bootpath = DevicePathToStr(li->FilePath);
+
+	/* Check the beginning of the string and the end, to avoid
+	 * caring about which arch this is. */
+	/* I really don't know why, but sometimes bootpath gives us
+	 * L"\\EFI\\BOOT\\/BOOTX64.EFI".  So just handle that here...
+	 */
+	if (StrnCaseCmp(bootpath, L"\\EFI\\BOOT\\BOOT", 14) &&
+			StrnCaseCmp(bootpath, L"\\EFI\\BOOT\\/BOOT", 15) &&
+			StrnCaseCmp(bootpath, L"EFI\\BOOT\\BOOT", 13) &&
+			StrnCaseCmp(bootpath, L"EFI\\BOOT\\/BOOT", 14))
+		goto error;
+
+	pathlen = StrLen(bootpath);
+	if (pathlen < 5 || StrCaseCmp(bootpath + pathlen - 4, L".EFI"))
+		goto error;
+
+	ret = 1;
+
+error:
+	if (bootpath)
+		FreePool(bootpath);
+
+	return ret;
+}
+
+
+// vim:fenc=utf-8:tw=75:noet

include/dp.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+/*
+ * dp.h - device path helper functions
+ * Copyright Peter Jones <[email protected]>
+ */
+
+#ifndef DP_H_
+#define DP_H_
+
+int
+is_removable_media_path(EFI_LOADED_IMAGE *li);
+
+#endif /* !DP_H_ */
+// vim:fenc=utf-8:tw=75:noet

mok.c

@@ -50,6 +50,32 @@ static EFI_STATUS check_mok_request(EFI_HANDLE image_handle)
 		efi_status = start_image(image_handle, MOK_MANAGER);
 
 		if (EFI_ERROR(efi_status)) {
+			/*
+			 * We don't do this in the unit tests because we
+			 * don't have simulation for console_countdown()
+			 * and similar.
+			 */
+#ifndef SHIM_UNIT_TEST
+			EFI_STATUS efi_status_2;
+			EFI_LOADED_IMAGE *li;
+			efi_status_2 = BS->HandleProtocol(image_handle, &EFI_LOADED_IMAGE_GUID,
+							 (void **)&li);
+			if (EFI_ERROR(efi_status_2))
+				perror (L"Failed to get image: %r\n", efi_status_2);
+			else if (is_removable_media_path(li) &&
+				 efi_status == EFI_NOT_FOUND) {
+				CHAR16 *title = L"Could not find MokManager";
+				CHAR16 *message = L"MokManager is missing on removable media.";
+				/*
+				 * This occurs when system is booting on
+				 * hard disk's EFI/BOOT/BOOTxxx.EFI entry
+				 * while it should have booted on
+				 * EFI/<os>/shimxxx.efi entry
+				 */
+				console_countdown(title, message, 10);
+				RT->ResetSystem(EfiResetWarm, EFI_SUCCESS, 0, NULL);
+			}
+#endif
 			perror(L"Failed to start MokManager: %r\n", efi_status);
 			return efi_status;
 		}

shim.c

@@ -778,39 +778,6 @@ verify_buffer (char *data, int datasize,
 	return verify_buffer_sbat(data, datasize, context);
 }
 
-static int
-is_removable_media_path(EFI_LOADED_IMAGE *li)
-{
-	unsigned int pathlen = 0;
-	CHAR16 *bootpath = NULL;
-	int ret = 0;
-
-	bootpath = DevicePathToStr(li->FilePath);
-
-	/* Check the beginning of the string and the end, to avoid
-	 * caring about which arch this is. */
-	/* I really don't know why, but sometimes bootpath gives us
-	 * L"\\EFI\\BOOT\\/BOOTX64.EFI".  So just handle that here...
-	 */
-	if (StrnCaseCmp(bootpath, L"\\EFI\\BOOT\\BOOT", 14) &&
-			StrnCaseCmp(bootpath, L"\\EFI\\BOOT\\/BOOT", 15) &&
-			StrnCaseCmp(bootpath, L"EFI\\BOOT\\BOOT", 13) &&
-			StrnCaseCmp(bootpath, L"EFI\\BOOT\\/BOOT", 14))
-		goto error;
-
-	pathlen = StrLen(bootpath);
-	if (pathlen < 5 || StrCaseCmp(bootpath + pathlen - 4, L".EFI"))
-		goto error;
-
-	ret = 1;
-
-error:
-	if (bootpath)
-		FreePool(bootpath);
-
-	return ret;
-}
-
 static int
 should_use_fallback(EFI_HANDLE image_handle)
 {
@@ -1154,7 +1121,7 @@ EFI_STATUS read_image(EFI_HANDLE image_handle, CHAR16 *ImagePath,
 		efi_status = load_image(shim_li, data, datasize, *PathName);
 		if (EFI_ERROR(efi_status)) {
 			perror(L"Failed to load image %s: %r\n",
-			       PathName, efi_status);
+			       *PathName, efi_status);
 			PrintErrors();
 			ClearErrors();
 			return efi_status;

shim.h

@@ -163,6 +163,7 @@
 #include "include/configtable.h"
 #include "include/console.h"
 #include "include/crypt_blowfish.h"
+#include "include/dp.h"
 #include "include/efiauthenticated.h"
 #include "include/errors.h"
 #include "include/execute.h"