cmd: efidebug: rework "boot dump" sub-command using GetNextVariableName()

Currently in do_efi_boot_dump(), we directly read EFI variables from
related environment variables. To accommodate alternative storage
backends, we should switch to using the UEFI API instead.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/cmd/efidebug.c b/cmd/efidebug.c
index a40c4f4be286ba49142719a00cae482e22006e33..efe4ea873eecacefb888bb208485edc9962e7bed 100644 (file)
--- a/cmd/efidebug.c
+++ b/cmd/efidebug.c
@@ -693,6 +693,17 @@ static void show_efi_boot_opt(int id)
        free(data);
 }
 
+static int u16_tohex(u16 c)
+{
+       if (c >= '0' && c <= '9')
+               return c - '0';
+       if (c >= 'A' && c <= 'F')
+               return c - 'A' + 10;
+
+       /* not hexadecimal */
+       return -1;
+}
+
 /**
  * show_efi_boot_dump() - dump all UEFI load options
  *
@@ -709,38 +720,58 @@ static void show_efi_boot_opt(int id)
 static int do_efi_boot_dump(cmd_tbl_t *cmdtp, int flag,
                            int argc, char * const argv[])
 {
-       char regex[256];
-       char * const regexlist[] = {regex};
-       char *variables = NULL, *boot, *value;
-       int len;
-       int id;
+       u16 *var_name16, *p;
+       efi_uintn_t buf_size, size;
+       efi_guid_t guid;
+       int id, i, digit;
+       efi_status_t ret;
 
        if (argc > 1)
                return CMD_RET_USAGE;
 
-       snprintf(regex, 256, "efi_.*-.*-.*-.*-.*_Boot[0-9A-F]+");
-
-       /* TODO: use GetNextVariableName? */
-       len = hexport_r(&env_htab, '\n', H_MATCH_REGEX | H_MATCH_KEY,
-                       &variables, 0, 1, regexlist);
-
-       if (!len)
-               return CMD_RET_SUCCESS;
-
-       if (len < 0)
+       buf_size = 128;
+       var_name16 = malloc(buf_size);
+       if (!var_name16)
                return CMD_RET_FAILURE;
 
-       boot = variables;
-       while (*boot) {
-               value = strstr(boot, "Boot") + 4;
-               id = (int)simple_strtoul(value, NULL, 16);
-               show_efi_boot_opt(id);
-               boot = strchr(boot, '\n');
-               if (!*boot)
+       var_name16[0] = 0;
+       for (;;) {
+               size = buf_size;
+               ret = EFI_CALL(efi_get_next_variable_name(&size, var_name16,
+                                                         &guid));
+               if (ret == EFI_NOT_FOUND)
                        break;
-               boot++;
+               if (ret == EFI_BUFFER_TOO_SMALL) {
+                       buf_size = size;
+                       p = realloc(var_name16, buf_size);
+                       if (!p) {
+                               free(var_name16);
+                               return CMD_RET_FAILURE;
+                       }
+                       var_name16 = p;
+                       ret = EFI_CALL(efi_get_next_variable_name(&size,
+                                                                 var_name16,
+                                                                 &guid));
+               }
+               if (ret != EFI_SUCCESS) {
+                       free(var_name16);
+                       return CMD_RET_FAILURE;
+               }
+
+               if (memcmp(var_name16, L"Boot", 8))
+                       continue;
+
+               for (id = 0, i = 0; i < 4; i++) {
+                       digit = u16_tohex(var_name16[4 + i]);
+                       if (digit < 0)
+                               break;
+                       id = (id << 4) + digit;
+               }
+               if (i == 4 && !var_name16[8])
+                       show_efi_boot_opt(id);
        }
-       free(variables);
+
+       free(var_name16);
 
        return CMD_RET_SUCCESS;
 }