2009-03-29 Yoshinori K. Okuji <okuji@enbug.org>

Make the format of Environment Block plain text. The boot loader
    part is not tested well yet.
    
    * util/grub-editenv.c (DEFAULT_ENVBLK_SIZE): New macro.
    (buffer): Removed.
    (envblk): Likewise.
    (usage): Remove "info" and "clear". Add "unset". Update the
    description of "set", as this does not delete variables any
    longer.
    (create_envblk_file): Complete rewrite.
    (open_envblk_file): Likewise.
    (cmd_info): Removed.
    (cmd_list): Likewise.
    (cmd_set): Likewise.
    (cmd_clear): Likewise.
    (list_variables): New function.
    (write_envblk): Likewise.
    (set_variables): Likewise.
    (unset_variables): Likewise.
    (main): Complete rewrite.

    * commands/loadenv.c (buffer): Removed.
    (envblk): Likewise.
    (open_envblk_file): New function.
    (read_envblk_file): Complete rewrite.
    (grub_cmd_load_env): Likewise.
    (grub_cmd_list_env): Likewise.
    (struct blocklist): New struct.
    (free_blocklists): New function.
    (check_blocklists): Likewise.
    (write_blocklists): Likewise.
    (grub_cmd_save_env): Complete rewrite.

    * include/grub/lib/envblk.h (GRUB_ENVBLK_SIGNATURE): Replaced with
    a plain text signature.
    (GRUB_ENVBLK_MAXLEN): Removed.
    (struct grub_envblk): Complete rewrite.
    (grub_envblk_find): Removed.
    (grub_envblk_insert): Likewise.
    (grub_envblk_open): New prototype.
    (grub_envblk_set): Likewise.
    (grub_envblk_delete): Put const to VALUE.
    (grub_envblk_iterate): Put const to NAME and VALUE.
    (grub_envblk_close): New prototype.
    (grub_envblk_buffer): New inline function.
    (grub_envblk_size): Likewise.

    * lib/envblk.c: Include grub/mm.h.
    (grub_env_find): Removed.
    (grub_envblk_open): New function.
    (grub_envblk_close): Likewise.
    (escaped_value_len): Likewise.
    (find_next_line): Likewise.
    (grub_envblk_insert): Removed.
    (grub_envblk_set): New function.
    (grub_envblk_delete): Complete rewrite.
    (grub_envblk_iterate): Likewise.

ChangeLog

@@ -1,3 +1,63 @@
+2009-03-29  Yoshinori K. Okuji  <okuji@enbug.org>
+
+	Make the format of Environment Block plain text. The boot loader
+	part is not tested well yet.
+	
+	* util/grub-editenv.c (DEFAULT_ENVBLK_SIZE): New macro.
+	(buffer): Removed.
+	(envblk): Likewise.
+	(usage): Remove "info" and "clear". Add "unset". Update the
+	description of "set", as this does not delete variables any
+	longer.
+	(create_envblk_file): Complete rewrite.
+	(open_envblk_file): Likewise.
+	(cmd_info): Removed.
+	(cmd_list): Likewise.
+	(cmd_set): Likewise.
+	(cmd_clear): Likewise.
+	(list_variables): New function.
+	(write_envblk): Likewise.
+	(set_variables): Likewise.
+	(unset_variables): Likewise.
+	(main): Complete rewrite.
+
+	* commands/loadenv.c (buffer): Removed.
+	(envblk): Likewise.
+	(open_envblk_file): New function.
+	(read_envblk_file): Complete rewrite.
+	(grub_cmd_load_env): Likewise.
+	(grub_cmd_list_env): Likewise.
+	(struct blocklist): New struct.
+	(free_blocklists): New function.
+	(check_blocklists): Likewise.
+	(write_blocklists): Likewise.
+	(grub_cmd_save_env): Complete rewrite.
+
+	* include/grub/lib/envblk.h (GRUB_ENVBLK_SIGNATURE): Replaced with
+	a plain text signature.
+	(GRUB_ENVBLK_MAXLEN): Removed.
+	(struct grub_envblk): Complete rewrite.
+	(grub_envblk_find): Removed.
+	(grub_envblk_insert): Likewise.
+	(grub_envblk_open): New prototype.
+	(grub_envblk_set): Likewise.
+	(grub_envblk_delete): Put const to VALUE.
+	(grub_envblk_iterate): Put const to NAME and VALUE.
+	(grub_envblk_close): New prototype.
+	(grub_envblk_buffer): New inline function.
+	(grub_envblk_size): Likewise.
+
+	* lib/envblk.c: Include grub/mm.h.
+	(grub_env_find): Removed.
+	(grub_envblk_open): New function.
+	(grub_envblk_close): Likewise.
+	(escaped_value_len): Likewise.
+	(find_next_line): Likewise.
+	(grub_envblk_insert): Removed.
+	(grub_envblk_set): New function.
+	(grub_envblk_delete): Complete rewrite.
+	(grub_envblk_iterate): Likewise.
+
 2009-03-28  Robert Millan  <rmh@aybabtu.com>
 
 	* conf/i386-pc.rmk (pkglib_MODULES): Add `linux16.mod'.

commands/loadenv.c

@@ -1,7 +1,7 @@
 /* loadenv.c - command to load/save environment variable.  */
 /*
  *  GRUB  --  GRand Unified Bootloader
- *  Copyright (C) 2008  Free Software Foundation, Inc.
+ *  Copyright (C) 2008,2009  Free Software Foundation, Inc.
  *
  *  GRUB is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -33,13 +33,9 @@ static const struct grub_arg_option options[] =
     {0, 0, 0, 0, 0, 0}
   };
 
-char buffer[GRUB_ENVBLK_MAXLEN];
-grub_envblk_t envblk;
-
 static grub_file_t
-read_envblk_file (char *filename, void NESTED_FUNC_ATTR read_hook (grub_disk_addr_t sector, unsigned offset, unsigned length))
+open_envblk_file (char *filename)
 {
-  char *buf = 0;
   grub_file_t file;
 
   if (! filename)
@@ -52,11 +48,16 @@ read_envblk_file (char *filename, void NESTED_FUNC_ATTR read_hook (grub_disk_add
           int len;
 
           len = grub_strlen (prefix);
-          buf = grub_malloc (len + 1 + sizeof (GRUB_ENVBLK_DEFCFG));
+          filename = grub_malloc (len + 1 + sizeof (GRUB_ENVBLK_DEFCFG));
-          grub_strcpy (buf, prefix);
+          if (! filename)
-          buf[len] = '/';
+            return 0;
-          grub_strcpy (buf + len + 1, GRUB_ENVBLK_DEFCFG);
+          
-          filename = buf;
+          grub_strcpy (filename, prefix);
+          filename[len] = '/';
+          grub_strcpy (filename + len + 1, GRUB_ENVBLK_DEFCFG);
+          file = grub_file_open (filename);
+          grub_free (filename);
+          return file;
         }
       else
         {
@@ -65,66 +66,78 @@ read_envblk_file (char *filename, void NESTED_FUNC_ATTR read_hook (grub_disk_add
         }
     }
 
-  file = grub_file_open (filename);
+  return grub_file_open (filename);
-  grub_free (buf);
+}
-  if (! file)
-    return 0;
 
-  if (read_hook)
+static grub_envblk_t
+read_envblk_file (grub_file_t file)
+{
+  grub_off_t offset = 0;
+  char *buf;
+  grub_size_t size = grub_file_size (file);
+  grub_envblk_t envblk;
+
+  buf = grub_malloc (size);
+  if (! buf)
+    return 0;
+  
+  while (size > 0)
     {
-      if (! file->device->disk)
+      grub_ssize_t ret;
+
+      ret = grub_file_read (file, buf + offset, size);
+      if (ret <= 0)
         {
-          grub_file_close (file);
+          if (grub_errno == GRUB_ERR_NONE)
-          grub_error (GRUB_ERR_BAD_DEVICE,
+            grub_error (GRUB_ERR_FILE_READ_ERROR, "cannot read");
-                      "this command is available only for disk devices.");
+          grub_free (buf);
           return 0;
         }
-      file->read_hook = read_hook;
+
+      size -= ret;
+      offset += ret;
     }
 
-  if (grub_file_read (file, buffer, GRUB_ENVBLK_MAXLEN) != GRUB_ENVBLK_MAXLEN)
+  envblk = grub_envblk_open (buf, offset);
-    {
-      grub_file_close (file);
-      grub_error (GRUB_ERR_BAD_FILE_TYPE, "file too short");
-      return 0;
-    }
-
-  envblk = grub_envblk_find (buffer);
   if (! envblk)
     {
-      grub_file_close (file);
+      grub_free (buf);
-      grub_error (GRUB_ERR_BAD_FILE_TYPE, "environment block not found");
+      grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid environment block");
       return 0;
     }
 
-  return file;
+  return envblk;
 }
 
 static grub_err_t
 grub_cmd_load_env (grub_extcmd_t cmd,
 		   int argc __attribute__ ((unused)),
 		   char **args __attribute__ ((unused)))
-
 {
   struct grub_arg_list *state = cmd->state;
   grub_file_t file;
+  grub_envblk_t envblk;
 
-  auto int hook (char *name, char *value);
+  auto int set_var (const char *name, const char *value);
-  int hook (char *name, char *value)
+  int set_var (const char *name, const char *value)
-    {
+  {
-      grub_env_set (name, value);
+    grub_env_set (name, value);
-
+    return 0;
-      return 0;
+  }
-    }
+  
-
+  file = open_envblk_file ((state[0].set) ? state[0].arg : 0);
-  file = read_envblk_file ((state[0].set) ? state[0].arg : 0, 0);
   if (! file)
     return grub_errno;
 
+  envblk = read_envblk_file (file);
+  if (! envblk)
+    goto fail;
+
+  grub_envblk_iterate (envblk, set_var);
+  grub_envblk_close (envblk);
+  
+ fail:
   grub_file_close (file);
-
-  grub_envblk_iterate (envblk, hook);
-
   return grub_errno;
 }
 
@@ -135,83 +148,207 @@ grub_cmd_list_env (grub_extcmd_t cmd,
 {
   struct grub_arg_list *state = cmd->state;
   grub_file_t file;
+  grub_envblk_t envblk;
 
-  auto int hook (char *name, char *value);
+  /* Print all variables in current context.  */
-  int hook (char *name, char *value)
+  auto int print_var (const char *name, const char *value);
+  int print_var (const char *name, const char *value)
     {
       grub_printf ("%s=%s\n", name, value);
-
       return 0;
     }
-
+ 
-  file = read_envblk_file ((state[0].set) ? state[0].arg : 0, 0);
+  file = open_envblk_file ((state[0].set) ? state[0].arg : 0);
   if (! file)
     return grub_errno;
 
+  envblk = read_envblk_file (file);
+  if (! envblk)
+    goto fail;
+
+  grub_envblk_iterate (envblk, print_var);
+  grub_envblk_close (envblk);
+  
+ fail:
   grub_file_close (file);
-
-  grub_envblk_iterate (envblk, hook);
-
   return grub_errno;
 }
 
+/* Used to maintain a variable length of blocklists internally.  */
+struct blocklist
+{
+  grub_disk_addr_t sector;
+  unsigned offset;
+  unsigned length;
+  struct blocklist *next;
+};
+
+static void
+free_blocklists (struct blocklist *p)
+{
+  struct blocklist *q;
+
+  for (; p; p = q)
+    {
+      q = p->next;
+      grub_free (p);
+    }
+}
+
+static int
+check_blocklists (grub_envblk_t envblk, struct blocklist *blocklists,
+                  grub_file_t file)
+{
+  grub_size_t total_length;
+  grub_size_t index;
+  grub_disk_t disk;
+  grub_disk_addr_t part_start;
+  struct blocklist *p;
+  char *buf;
+  
+  /* Sanity checks.  */
+  total_length = 0;
+  for (p = blocklists; p; p = p->next)
+    {
+      struct blocklist *q;
+      for (q = p->next; q; q = q->next)
+        {
+          /* Check if any pair of blocks overlap.  */
+          if (p->sector == q->sector)
+            {
+              /* This might be actually valid, but it is unbelievable that
+                 any filesystem makes such a silly allocation.  */
+              grub_error (GRUB_ERR_BAD_FS, "malformed file");
+              return 0;
+            }
+        }
+      
+      total_length += p->length;
+    }
+  
+  if (total_length != grub_file_size (file))
+    {
+      /* Maybe sparse, unallocated sectors. No way in GRUB.  */
+      grub_error (GRUB_ERR_BAD_FILE_TYPE, "sparse file not allowed");
+      return 0;
+    }
+
+  /* One more sanity check. Re-read all sectors by blocklists, and compare
+     those with the data read via a file.  */
+  disk = file->device->disk;
+  if (disk->partition)
+    part_start = grub_partition_get_start (disk->partition);
+  else
+    part_start = 0;
+
+  buf = grub_envblk_buffer (envblk);
+  for (p = blocklists, index = 0; p; p = p->next, index += p->length)
+    {
+      char blockbuf[GRUB_DISK_SECTOR_SIZE];
+      
+      if (grub_disk_read (disk, p->sector - part_start,
+                          p->offset, p->length, blockbuf))
+        return 0;
+
+      if (grub_memcmp (buf + index, blockbuf, p->length) != 0)
+        {
+          grub_error (GRUB_ERR_FILE_READ_ERROR, "invalid blocklist");
+          return 0;
+        }
+    }
+
+  return 1;
+}
+
+static int
+write_blocklists (grub_envblk_t envblk, struct blocklist *blocklists,
+                  grub_file_t file)
+{
+  char *buf;
+  grub_disk_t disk;
+  grub_disk_addr_t part_start;
+  struct blocklist *p;
+  grub_size_t index;
+  
+  buf = grub_envblk_buffer (envblk);
+  disk = file->device->disk;
+  if (disk->partition)
+    part_start = grub_partition_get_start (disk->partition);
+  else
+    part_start = 0;
+
+  index = 0;
+  for (p = blocklists; p; p = p->next, index += p->length)
+    {
+      if (grub_disk_write (disk, p->sector - part_start,
+                           p->offset, p->length, buf + index))
+        return 0;
+    }
+
+  return 1;
+}
+
 static grub_err_t
 grub_cmd_save_env (grub_extcmd_t cmd, int argc, char **args)
 {
   struct grub_arg_list *state = cmd->state;
   grub_file_t file;
-  grub_disk_t disk;
+  grub_envblk_t envblk;
-  grub_disk_addr_t addr[GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS];
+  struct blocklist *head = 0;
-  char buf[GRUB_DISK_SECTOR_SIZE];
+  struct blocklist *tail = 0;
-  grub_disk_addr_t part_start = 0;
+  
-  int num = 0;
+  /* Store blocklists in a linked list.  */
-
+  auto void NESTED_FUNC_ATTR read_hook (grub_disk_addr_t sector,
-  auto void NESTED_FUNC_ATTR hook (grub_disk_addr_t sector, unsigned offset,
+                                        unsigned offset,
-                                   unsigned length);
+                                        unsigned length);
-
+  void NESTED_FUNC_ATTR read_hook (grub_disk_addr_t sector,
-  void NESTED_FUNC_ATTR hook (grub_disk_addr_t sector,
+                                   unsigned offset, unsigned length)
-                              unsigned offset, unsigned length)
     {
-      if ((offset != 0) || (length != GRUB_DISK_SECTOR_SIZE))
+      struct blocklist *block;
+
+      if (offset + length > GRUB_DISK_SECTOR_SIZE)
+        /* Seemingly a bug.  */
+        return;
+      
+      block = grub_malloc (sizeof (*block));
+      if (! block)
         return;
 
-      if (num < (GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS))
+      block->sector = sector;
-        addr[num++] = sector;
+      block->offset = offset;
+      block->length = length;
+
+      /* Slightly complicated, because the list should be FIFO.  */
+      block->next = 0;
+      if (tail)
+        tail->next = block;
+      tail = block;
+      if (! head)
+        head = block;
     }
 
   if (! argc)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, "No variable is specified");
 
-  file = read_envblk_file ((state[0].set) ? state[0].arg : 0, hook);
+  file = open_envblk_file ((state[0].set) ? state[0].arg : 0);
   if (! file)
     return grub_errno;
 
+  if (! file->device->disk)
+    {
+      grub_file_close (file);
+      return grub_error (GRUB_ERR_BAD_DEVICE, "disk device required");
+    }
+
+  file->read_hook = read_hook;
+  envblk = read_envblk_file (file);
   file->read_hook = 0;
+  if (! envblk)
+    goto fail;
 
-  if (num != GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS)
+  if (! check_blocklists (envblk, head, file))
-    {
+    goto fail;
-      grub_error (GRUB_ERR_BAD_DEVICE, "invalid blocklist");
+  
-      goto quit;
-    }
-
-  disk = file->device->disk;
-  if (disk->partition)
-    part_start = grub_partition_get_start (disk->partition);
-
-  for (num = 0; num < (GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS); num++)
-    {
-      if (grub_disk_read (disk, addr[num] - part_start, 0,
-                          GRUB_DISK_SECTOR_SIZE,  buf))
-        goto quit;
-
-      if (grub_memcmp (&buffer[num << GRUB_DISK_SECTOR_BITS], buf,
-                       GRUB_DISK_SECTOR_SIZE))
-        {
-          grub_error (GRUB_ERR_BAD_DEVICE, "invalid blocklist");
-          goto quit;
-        }
-    }
-
   while (argc)
     {
       char *value;
@@ -219,10 +356,10 @@ grub_cmd_save_env (grub_extcmd_t cmd, int argc, char **args)
       value = grub_env_get (args[0]);
       if (value)
         {
-          if (grub_envblk_insert (envblk, args[0], value))
+          if (! grub_envblk_set (envblk, args[0], value))
             {
               grub_error (GRUB_ERR_BAD_ARGUMENT, "environment block too small");
-              goto quit;
+              goto fail;
             }
         }
 
@@ -230,15 +367,13 @@ grub_cmd_save_env (grub_extcmd_t cmd, int argc, char **args)
       args++;
     }
 
-  for (num = 0; num < (GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS); num++)
+  write_blocklists (envblk, head, file);
-    if (grub_disk_write (disk, addr[num] - part_start, 0,
+  
-                         GRUB_DISK_SECTOR_SIZE,
+ fail:
-                         &buffer[num << GRUB_DISK_SECTOR_BITS]))
+  if (envblk)
-      goto quit;
+    grub_envblk_close (envblk);
-
+  free_blocklists (head);
-quit:
   grub_file_close (file);
-
   return grub_errno;
 }
 

config.h.in

@@ -4,6 +4,9 @@
    prefixed with an asterisk */
 #undef ABSOLUTE_WITHOUT_ASTERISK
 
+/* Define if building universal (internal helper macro) */
+#undef AC_APPLE_UNIVERSAL_BUILD
+
 /* Define it to \"addr32\" or \"addr32;\" to make GAS happy */
 #undef ADDR32
 
@@ -112,17 +115,52 @@
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
-/* Define to 1 if your processor stores words with the most significant byte
+/* Enable extensions on AIX 3, Interix.  */
-   first (like Motorola and SPARC, unlike Intel and VAX). */
+#ifndef _ALL_SOURCE
-#undef WORDS_BIGENDIAN
+# undef _ALL_SOURCE
-
+#endif
-/* Number of bits in a file offset, on hosts where this is settable. */
-#undef _FILE_OFFSET_BITS
-
 /* Enable GNU extensions on systems that have them.  */
 #ifndef _GNU_SOURCE
 # undef _GNU_SOURCE
 #endif
+/* Enable threading extensions on Solaris.  */
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# undef _POSIX_PTHREAD_SEMANTICS
+#endif
+/* Enable extensions on HP NonStop.  */
+#ifndef _TANDEM_SOURCE
+# undef _TANDEM_SOURCE
+#endif
+/* Enable general extensions on Solaris.  */
+#ifndef __EXTENSIONS__
+# undef __EXTENSIONS__
+#endif
+
+
+/* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
+   significant byte first (like Motorola and SPARC, unlike Intel). */
+#if defined AC_APPLE_UNIVERSAL_BUILD
+# if defined __BIG_ENDIAN__
+#  define WORDS_BIGENDIAN 1
+# endif
+#else
+# ifndef WORDS_BIGENDIAN
+#  undef WORDS_BIGENDIAN
+# endif
+#endif
+
+/* Number of bits in a file offset, on hosts where this is settable. */
+#undef _FILE_OFFSET_BITS
 
 /* Define for large files, on AIX-style hosts. */
 #undef _LARGE_FILES
+
+/* Define to 1 if on MINIX. */
+#undef _MINIX
+
+/* Define to 2 if the system does not provide POSIX.1 features except with
+   this defined. */
+#undef _POSIX_1_SOURCE
+
+/* Define to 1 if you need to in order for `stat' and other things to work. */
+#undef _POSIX_SOURCE

include/grub/lib/envblk.h

@@ -1,6 +1,6 @@
 /*
  *  GRUB  --  GRand Unified Bootloader
- *  Copyright (C) 2008  Free Software Foundation, Inc.
+ *  Copyright (C) 2008,2009  Free Software Foundation, Inc.
  *
  *  GRUB is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -19,27 +19,37 @@
 #ifndef GRUB_ENVBLK_HEADER
 #define GRUB_ENVBLK_HEADER	1
 
-#define GRUB_ENVBLK_SIGNATURE	0x764e6547	/* GeNv  */
+#define GRUB_ENVBLK_SIGNATURE	"# GRUB Environment Block\n"
-
-#define GRUB_ENVBLK_MAXLEN	8192
-
 #define GRUB_ENVBLK_DEFCFG	"grubenv"
 
 #ifndef ASM_FILE
 
 struct grub_envblk
 {
-  grub_uint32_t signature;
+  char *buf;
-  grub_uint16_t length;
+  grub_size_t size;
-  char data[0];
+};
-} __attribute__ ((packed));
 typedef struct grub_envblk *grub_envblk_t;
 
-grub_envblk_t grub_envblk_find (char *buf);
+grub_envblk_t grub_envblk_open (char *buf, grub_size_t size);
-int grub_envblk_insert (grub_envblk_t envblk, char *name, char *value);
+int grub_envblk_set (grub_envblk_t envblk, const char *name, const char *value);
-void grub_envblk_delete (grub_envblk_t envblk, char *name);
+void grub_envblk_delete (grub_envblk_t envblk, const char *name);
-void grub_envblk_iterate (grub_envblk_t envblk, int hook (char *name, char *value));
+void grub_envblk_iterate (grub_envblk_t envblk,
+                          int hook (const char *name, const char *value));
+void grub_envblk_close (grub_envblk_t envblk);
 
-#endif
+static inline char *
+grub_envblk_buffer (const grub_envblk_t envblk)
+{
+  return envblk->buf;
+}
+
+static inline grub_size_t
+grub_envblk_size (const grub_envblk_t envblk)
+{
+  return envblk->size;
+}
+
+#endif /* ! ASM_FILE */
 
 #endif /* ! GRUB_ENVBLK_HEADER */

lib/envblk.c

@@ -1,7 +1,7 @@
-/* envblk.c - Common function for environment block.  */
+/* envblk.c - Common functions for environment block.  */
 /*
  *  GRUB  --  GRand Unified Bootloader
- *  Copyright (C) 2008  Free Software Foundation, Inc.
+ *  Copyright (C) 2008,2009  Free Software Foundation, Inc.
  *
  *  GRUB is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -20,137 +20,277 @@
 #include <config.h>
 #include <grub/types.h>
 #include <grub/misc.h>
+#include <grub/mm.h>
 #include <grub/lib/envblk.h>
 
 grub_envblk_t
-grub_envblk_find (char *buf)
+grub_envblk_open (char *buf, grub_size_t size)
 {
-  grub_uint32_t *pd;
+  grub_envblk_t envblk;
-  int len;
 
-  pd = (grub_uint32_t *) buf;
+  if (size < sizeof (GRUB_ENVBLK_SIGNATURE)
-
+      || grub_memcmp (buf, GRUB_ENVBLK_SIGNATURE,
-  for (len = GRUB_ENVBLK_MAXLEN - 6; len > 0; len -= 4, pd++)
+                      sizeof (GRUB_ENVBLK_SIGNATURE) - 1))
-    if (*pd == GRUB_ENVBLK_SIGNATURE)
-      {
-        grub_envblk_t p;
-
-        p = (grub_envblk_t) pd;
-        if (p->length <= len)
-          return p;
-      }
-
-  return 0;
-}
-
-int
-grub_envblk_insert (grub_envblk_t envblk, char *name, char *value)
-{
-  char *p, *pend;
-  char *found = 0;
-  int nl;
-
-  nl = grub_strlen (name);
-  p = envblk->data;
-  pend = p + envblk->length;
-
-  while (*p)
     {
-      if ((! found) && (! grub_memcmp (name, p, nl)) && (p[nl] == '='))
+      grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid environment block");
-        found = p + nl + 1;
+      return 0;
-
-      p += grub_strlen (p) + 1;
-      if (p >= pend)
-        return 1;
     }
-
+  
-  if (found)
+  envblk = grub_malloc (sizeof (*envblk));
+  if (envblk)
     {
-      int len1, len2;
+      envblk->buf = buf;
-
+      envblk->size = size;
-      len1 = grub_strlen (found);
-      len2 = grub_strlen (value);
-      if ((p - envblk->data) + 1 - len1 + len2 > envblk->length)
-        return 1;
-
-      grub_memcpy (found + len2 + 1, found + len1 + 1, (p - found) - len1);
-      grub_strcpy (found, value);
     }
-  else
+  
-    {
+  return envblk;
-      int len2 = grub_strlen (value);
-
-      if ((p - envblk->data) + nl + 1 + len2 + 2 > envblk->length)
-        return 1;
-
-      grub_strcpy (p, name);
-      p[nl] = '=';
-      grub_strcpy (p + nl + 1, value);
-      p[nl + 1 + len2 + 1] = 0;
-    }
-
-  return 0;
 }
 
 void
-grub_envblk_delete (grub_envblk_t envblk, char *name)
+grub_envblk_close (grub_envblk_t envblk)
+{
+  grub_free (envblk->buf);
+  grub_free (envblk);
+}
+
+static int
+escaped_value_len (const char *value)
+{
+  int n = 0;
+  char *p;
+  
+  for (p = (char *) value; *p; p++)
+    {
+      if (*p == '\\' || *p == '\n')
+        n += 2;
+      else
+        n++;
+    }
+  
+  return n;
+}
+
+static char *
+find_next_line (char *p, const char *pend)
+{
+  while (p < pend)
+    {
+      if (*p == '\\')
+        p += 2;
+      else if (*p == '\n')
+        break;
+      else
+        p++;
+    }
+  
+  return p + 1;
+}
+
+int
+grub_envblk_set (grub_envblk_t envblk, const char *name, const char *value)
+{
+  char *p, *pend;
+  char *space;
+  int found = 0;
+  int nl;
+  int vl;
+  int i;
+
+  nl = grub_strlen (name);
+  vl = escaped_value_len (value);
+  p = envblk->buf + sizeof (GRUB_ENVBLK_SIGNATURE) - 1;
+  pend = envblk->buf + envblk->size;
+  
+  /* First, look at free space.  */
+  for (space = pend - 1; *space == '#'; space--)
+    ;
+
+  if (*space != '\n')
+    /* Broken.  */
+    return 0;
+
+  space++;
+
+  while (p + nl + 1 < space)
+    {
+      if (grub_memcmp (p, name, nl) == 0 && p[nl] == '=')
+        {
+          int len;
+          
+          /* Found the same name.  */
+          p += nl + 1;
+          
+          /* Check the length of the current value.  */
+          len = 0;
+          while (p + len < pend && p[len] != '\n')
+            {
+              if (p[len] == '\\')
+                len += 2;
+              else
+                len++;
+            }
+
+          if (p + len >= pend)
+            /* Broken.  */
+            return 0;
+
+          if (pend - space < vl - len)
+            /* No space.  */
+            return 0;
+
+          if (vl < len)
+            {
+              /* Move the following characters backward, and fill the new
+                 space with harmless characters.  */
+              grub_memmove (p + vl, p + len, pend - (p + len));
+              grub_memset (space + len - vl, '#', len - vl);
+            }
+          else
+            /* Move the following characters forward.  */
+            grub_memmove (p + vl, p + len, pend - (p + vl));
+
+          found = 1;
+          break;
+        }
+
+      p = find_next_line (p, pend);
+    }
+
+  if (! found)
+    {
+      /* Append a new variable.  */
+      
+      if (pend - space < nl + 1 + vl + 1)
+        /* No space.  */
+        return 0;
+
+      grub_memcpy (space, name, nl);
+      p = space + nl;
+      *p++ = '=';
+    }
+
+  /* Write the value.  */
+  for (i = 0; value[i]; i++)
+    {
+      if (value[i] == '\\' || value[i] == '\n')
+        *p++ = '\\';
+      
+      *p++ = value[i];
+    }
+
+  *p = '\n';
+  return 1;
+}
+
+void
+grub_envblk_delete (grub_envblk_t envblk, const char *name)
 {
   char *p, *pend;
-  char *found = 0;
   int nl;
 
   nl = grub_strlen (name);
-  p = envblk->data;
+  p = envblk->buf + sizeof (GRUB_ENVBLK_SIGNATURE) - 1;
-  pend = p + envblk->length;
+  pend = envblk->buf + envblk->size;
 
-  while (*p)
+  while (p + nl + 1 < pend)
     {
-      if ((! found) && (! grub_memcmp (name, p, nl)) && (p[nl] == '='))
+      if (grub_memcmp (p, name, nl) == 0 && p[nl] == '=')
-        found = p;
+        {
+          /* Found.  */
+          int len = nl + 1;
 
-      p += grub_strlen (p) + 1;
+          while (p + len < pend)
-      if (p >= pend)
+            {
-        return;
+              if (p[len] == '\n')
-    }
+                break;
+              else if (p[len] == '\\')
+                len += 2;
+              else
+                len++;
+            }
 
-  if (found)
+          if (p + len >= pend)
-    {
+            /* Broken.  */
-      int len;
+            return;
 
-      len = grub_strlen (found);
+          len++;
-      grub_memcpy (found, found + len + 1, (p - found) - len);
+          grub_memmove (p, p + len, pend - (p + len));
-    }
+          grub_memset (pend - len, '#', len);
+          break;
+        }
+
+      p = find_next_line (p, pend);
+    }      
 }
 
 void
 grub_envblk_iterate (grub_envblk_t envblk,
-                     int hook (char *name, char *value))
+                     int hook (const char *name, const char *value))
 {
   char *p, *pend;
 
-  p = envblk->data;
+  p = envblk->buf + sizeof (GRUB_ENVBLK_SIGNATURE) - 1;
-  pend = p + envblk->length;
+  pend = envblk->buf + envblk->size;
 
-  while (*p)
+  while (p < pend)
     {
-      char *v;
+      if (*p != '#')
-      int r;
-
-      v = grub_strchr (p, '=');
-      if (v)
         {
-          *v = 0;
+          char *name;
-          r = hook (p, v + 1);
+          char *value;
-          *v = '=';
+          char *name_start, *name_end, *value_start;
+          char *q;
+          int ret;
+
+          name_start = p;
+          while (p < pend && *p != '=')
+            p++;
+          if (p == pend)
+            /* Broken.  */
+            return;
+          name_end = p;
+
+          p++;
+          value_start = p;
+          while (p < pend)
+            {
+              if (*p == '\n')
+                break;
+              else if (*p == '\\')
+                p += 2;
+              else
+                p++;
+            }
+          
+          if (p >= pend)
+            /* Broken.  */
+            return;
+
+          name = grub_malloc (p - name_start + 1);
+          if (! name)
+            /* out of memory.  */
+            return;
+
+          value = name + (value_start - name_start);
+          
+          grub_memcpy (name, name_start, name_end - name_start);
+          name[name_end - name_start] = '\0';
+          
+          for (p = value_start, q = value; *p != '\n'; ++p)
+            {
+              if (*p == '\\')
+                *q++ = *++p;
+              else
+                *q++ = *p;
+            }
+          *q = '\0';
+          
+          ret = hook (name, value);
+          grub_free (name);
+          if (ret)
+            return;
         }
-      else
+      
-        r = hook (p, "");
+      p = find_next_line (p, pend);
-
-      if (r)
-        break;
-
-      p += grub_strlen (p) + 1;
-      if (p >= pend)
-        break;
     }
 }

util/grub-editenv.c

@@ -1,7 +1,7 @@
 /* grub-editenv.c - tool to edit environment block.  */
 /*
  *  GRUB  --  GRand Unified Bootloader
- *  Copyright (C) 2008 Free Software Foundation, Inc.
+ *  Copyright (C) 2008,2009 Free Software Foundation, Inc.
  *
  *  GRUB is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -29,6 +29,8 @@
 #include <stdlib.h>
 #include <getopt.h>
 
+#define DEFAULT_ENVBLK_SIZE	1024
+
 void
 grub_putchar (int c)
 {
@@ -63,9 +65,6 @@ static struct option options[] = {
   {0, 0, 0, 0}
 };
 
-char buffer[GRUB_ENVBLK_MAXLEN];
-grub_envblk_t envblk;
-
 static void
 usage (int status)
 {
@@ -78,10 +77,9 @@ Usage: grub-editenv [OPTIONS] FILENAME COMMAND\n\
 Tool to edit environment block.\n\
 \nCommands:\n\
   create                    create a blank environment block file\n\
-  info                      show information about the environment block\n\
   list                      list the current variables\n\
-  set [name=value] ...      change/delete variables\n\
+  set [name=value ...]      set variables\n\
-  clear                     delete all variables\n\
+  unset [name ....]         delete variables\n\
 \nOptions:\n\
   -h, --help                display this message and exit\n\
   -V, --version             print version information and exit\n\
@@ -92,108 +90,161 @@ Report bugs to <%s>.\n", PACKAGE_BUGREPORT);
   exit (status);
 }
 
-int
+static void
-create_envblk_file (char *name)
+create_envblk_file (const char *name)
 {
-  FILE *f;
+  FILE *fp;
-  grub_envblk_t p;
+  char *buf;
+  
+  buf = malloc (DEFAULT_ENVBLK_SIZE);
+  if (! buf)
+    grub_util_error ("out of memory");
 
-  f = fopen (name, "wb");
+  fp = fopen (name, "wb");
-  if (! f)
+  if (! fp)
-    return 1;
+    grub_util_error ("cannot open the file %s", name);
 
-  /* Just in case OS don't save 0s.  */
+  memcpy (buf, GRUB_ENVBLK_SIGNATURE, sizeof (GRUB_ENVBLK_SIGNATURE) - 1);
-  memset (buffer, -1, sizeof (buffer));
+  memset (buf + sizeof (GRUB_ENVBLK_SIGNATURE) - 1, '#',
+          DEFAULT_ENVBLK_SIZE - sizeof (GRUB_ENVBLK_SIGNATURE) + 1);
+  
+  if (fwrite (buf, 1, DEFAULT_ENVBLK_SIZE, fp) != DEFAULT_ENVBLK_SIZE)
+    grub_util_error ("cannot write to the file %s", name);
 
-  p = (grub_envblk_t) &buffer[0];
+  fsync (fileno (fp));
-  p->signature = GRUB_ENVBLK_SIGNATURE;
+  free (buf);
-  p->length = sizeof (buffer) - sizeof (struct grub_envblk);
+  fclose (fp);
-  p->data[0] = p->data[1] = 0;
-
-  fwrite (buffer, sizeof (buffer), 1, f);
-
-  fclose (f);
-  return 0;
 }
 
-FILE *
+static grub_envblk_t
-open_envblk_file (char *name)
+open_envblk_file (const char *name)
 {
-  FILE *f;
+  FILE *fp;
+  char *buf;
+  size_t size;
+  grub_envblk_t envblk;
+  
+  fp = fopen (name, "rb");
+  if (! fp)
+    {
+      /* Create the file implicitly.  */
+      create_envblk_file (name);
+      fp = fopen (name, "rb");
+      if (! fp)
+        grub_util_error ("cannot open the file %s", name);
+    }
 
-  f = fopen (name, "r+b");
+  if (fseek (fp, 0, SEEK_END) < 0)
-  if (! f)
+    grub_util_error ("cannot seek the file %s", name);
-    grub_util_error ("Can\'t open file %s", name);
 
-  if (fread (buffer, 1, sizeof (buffer), f) != sizeof (buffer))
+  size = (size_t) ftell (fp);
-    grub_util_error ("The envblk file is too short");
 
-  envblk = grub_envblk_find (buffer);
+  if (fseek (fp, 0, SEEK_SET) < 0)
+    grub_util_error ("cannot seek the file %s", name);
+
+  buf = malloc (size);
+  if (! buf)
+    grub_util_error ("out of memory");
+  
+  if (fread (buf, 1, size, fp) != size)
+    grub_util_error ("cannot read the file %s", name);
+
+  fclose (fp);
+  
+  envblk = grub_envblk_open (buf, size);
   if (! envblk)
-    grub_util_error ("Can\'t find environment block");
+    grub_util_error ("invalid environment block");
 
-  return f;
+  return envblk;
 }
 
 static void
-cmd_info (void)
+list_variables (const char *name)
 {
-  printf ("Envblk offset: %ld\n", (long) (envblk->data - buffer));
+  grub_envblk_t envblk;
-  printf ("Envblk length: %d\n", envblk->length);
+  
-}
+  auto int print_var (const char *name, const char *value);
-
+  int print_var (const char *name, const char *value)
-static void
-cmd_list (void)
-{
-  auto int hook (char *name, char *value);
-  int hook (char *name, char *value)
     {
       printf ("%s=%s\n", name, value);
       return 0;
     }
 
-  grub_envblk_iterate (envblk, hook);
+  envblk = open_envblk_file (name);
+  grub_envblk_iterate (envblk, print_var);
+  grub_envblk_close (envblk);
 }
 
 static void
-cmd_set (int argc, char *argv[])
+write_envblk (const char *name, grub_envblk_t envblk)
 {
+  FILE *fp;
+  
+  fp = fopen (name, "wb");
+  if (! fp)
+    grub_util_error ("cannot open the file %s", name);
+  
+  if (fwrite (grub_envblk_buffer (envblk), 1, grub_envblk_size (envblk), fp)
+      != grub_envblk_size (envblk))
+    grub_util_error ("cannot write to the file %s", name);
+
+  fsync (fileno (fp));
+  fclose (fp);
+}
+
+static void
+set_variables (const char *name, int argc, char *argv[])
+{
+  grub_envblk_t envblk;
+  
+  envblk = open_envblk_file (name);
   while (argc)
     {
       char *p;
 
       p = strchr (argv[0], '=');
       if (! p)
-        grub_util_error ("Invalid parameter");
+        grub_util_error ("invalid parameter %s", argv[0]);
 
       *(p++) = 0;
 
-      if (*p)
+      if (! grub_envblk_set (envblk, argv[0], p))
-        {
+        grub_util_error ("environment block too small");
-          if (grub_envblk_insert (envblk, argv[0], p))
-            grub_util_error ("Environment block too small");
-        }
-      else
-        grub_envblk_delete (envblk, argv[0]);
 
       argc--;
       argv++;
     }
+
+  write_envblk (name, envblk);
+  grub_envblk_close (envblk);
 }
 
 static void
-cmd_clear (void)
+unset_variables (const char *name, int argc, char *argv[])
 {
-  envblk->data[0] = envblk->data[1] = 0;
+  grub_envblk_t envblk;
+  
+  envblk = open_envblk_file (name);
+  while (argc)
+    {
+      grub_envblk_delete (envblk, argv[0]);
+
+      argc--;
+      argv++;
+    }
+
+  write_envblk (name, envblk);
+  grub_envblk_close (envblk);
 }
 
 int
 main (int argc, char *argv[])
 {
-  FILE *f;
+  char *filename;
-
+  char *command;
+  
   progname = "grub-editenv";
-
+  
   /* Check for options.  */
   while (1)
     {
@@ -222,40 +273,35 @@ main (int argc, char *argv[])
 	  }
     }
 
-  /* Obtain PATH.  */
+  /* Obtain the filename.  */
   if (optind >= argc)
     {
-      fprintf (stderr, "Filename not specified.\n");
+      fprintf (stderr, "no filename specified\n");
       usage (1);
     }
 
   if (optind + 1 >= argc)
     {
-      fprintf (stderr, "Command not specified.\n");
+      fprintf (stderr, "no command specified\n");
+      usage (1);
+    }
+  
+  filename = argv[optind];
+  command = argv[optind + 1];
+
+  if (strcmp (command, "create") == 0)
+    create_envblk_file (filename);
+  else if (strcmp (command, "list") == 0)
+    list_variables (filename);
+  else if (strcmp (command, "set") == 0)
+    set_variables (filename, argc - optind - 2, argv + optind + 2);
+  else if (strcmp (command, "unset") == 0)
+    unset_variables (filename, argc - optind - 2, argv + optind + 2);
+  else
+    {
+      fprintf (stderr, "unknown command %s\n", command);
       usage (1);
     }
 
-  if (! strcmp (argv[optind + 1], "create"))
-    return create_envblk_file (argv[optind]);
-
-  f = open_envblk_file (argv[optind]);
-
-  optind++;
-  if (! strcmp (argv[optind], "info"))
-    cmd_info ();
-  else if (! strcmp (argv[optind], "list"))
-    cmd_list ();
-  else
-    {
-      if (! strcmp (argv[optind], "set"))
-        cmd_set (argc - optind - 1, argv + optind + 1);
-      else if (! strcmp (argv[optind], "clear"))
-        cmd_clear ();
-
-      fseeko (f, 0, SEEK_SET);
-      fwrite (buffer, sizeof (buffer), 1, f);
-    }
-  fclose (f);
-
   return 0;
 }