Filename expansion support for wildcards in GRUB script.

* tests/grub_script_expansion.in: New test. * Makefile.util.def: Rule for new test. * grub-core/commands/wildcard.c: New file, implements filename expansion support for GRUB script. * grub-core/Makefile.core.def: Rule update for regexp.mod. * grub-core/script/argv.c: Cosmetic changes. * grub-core/script/execute.c (grub_script_arglist_to_argv): Refactored to perform wildcard expansion on arguments. * include/grub/script_sh.h (grub_script_wildcard_translator): New struct. * tests/util/grub-shell.in: Fix quoting for read input.
2010-09-04 22:45:34 +05:30 · 2010-09-04 22:45:34 +05:30 · 35ee15e09a
parent 5f0c4acaca ee14ec9935
commit 35ee15e09a
10 changed files with 663 additions and 5 deletions
--- a/18
+++ b/18
@ -1,3 +1,21 @@
+2010-09-04  BVK Chaitanya  <bvk.groups@gmail.com>
+
+	Filename expansion support for wildcards in GRUB script.
+
+	* tests/grub_script_expansion.in: New test.
+	* Makefile.util.def: Rule for new test.
+
+	* grub-core/commands/wildcard.c: New file, implements filename
+	expansion support for GRUB script.
+	* grub-core/Makefile.core.def: Rule update for regexp.mod.
+	* grub-core/script/argv.c: Cosmetic changes.
+	* grub-core/script/execute.c (grub_script_arglist_to_argv):
+	Refactored to perform wildcard expansion on arguments.
+	* include/grub/script_sh.h (grub_script_wildcard_translator): New
+	struct.
+
+	* tests/util/grub-shell.in: Fix quoting for read input.
+
 2010-09-04  BVK Chaitanya  <bvk.groups@gmail.com>

 	Support for updating environment variables with matched substrings
--- a/Makefile.util.def
+++ b/Makefile.util.def
@ -525,6 +525,12 @@ script = {
  common = tests/grub_cmd_regexp.in;
 };

+script = {
+  testcase;
+  name = grub_script_expansion;
+  common = tests/grub_script_expansion.in;
+};
+
 program = {
  testcase;
  name = example_unit_test;
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@ -395,6 +395,7 @@ module = {
 module = {
  name = regexp;
  common = commands/regexp.c;
+  common = commands/wildcard.c;
  ldadd = libgnulib.a;
  cflags = '$(CFLAGS_POSIX) $(CFLAGS_GNULIB)';
  cppflags = '$(CPPFLAGS_POSIX) $(CPPFLAGS_GNULIB)';
--- a/grub-core/commands/regexp.c
+++ b/grub-core/commands/regexp.c
@ -24,6 +24,7 @@
 #include <grub/env.h>
 #include <grub/extcmd.h>
 #include <grub/i18n.h>
+#include <grub/script_sh.h>
 #include <regex.h>

 static const struct grub_arg_option options[] =
@ -138,9 +139,13 @@ GRUB_MOD_INIT(regexp)
  cmd = grub_register_extcmd ("regexp", grub_cmd_regexp,
 			      GRUB_COMMAND_FLAG_BOTH, N_("REGEXP STRING"),
 			      N_("Test if REGEXP matches STRING."), options);
+
+  /* Setup GRUB script wildcard translator.  */
+  grub_wildcard_translator = &grub_filename_translator;
 }

 GRUB_MOD_FINI(regexp)
 {
  grub_unregister_extcmd (cmd);
+  grub_wildcard_translator = 0;
 }
--- a/grub-core/commands/wildcard.c
+++ b/grub-core/commands/wildcard.c
@ -0,0 +1,494 @@
+/* wildcard.c - Wildcard character expansion for GRUB script.  */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2010  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
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/mm.h>
+#include <grub/fs.h>
+#include <grub/env.h>
+#include <grub/file.h>
+#include <grub/device.h>
+#include <grub/script_sh.h>
+
+#include <regex.h>
+
+static inline int isregexop (char ch);
+static char ** merge (char **lhs, char **rhs);
+static char *make_dir (const char *prefix, const char *start, const char *end);
+static int make_regex (const char *regex_start, const char *regex_end,
+		       regex_t *regexp);
+static void split_path (const char *path, const char **suffix_end, const char **regex_end);
+static char ** match_devices (const regex_t *regexp, int noparts);
+static char ** match_files (const char *prefix, const char *suffix_start,
+			    const char *suffix_end, const regex_t *regexp);
+
+static char* wildcard_escape (const char *s);
+static char* wildcard_unescape (const char *s);
+static grub_err_t wildcard_expand (const char *s, char ***strs);
+
+struct grub_script_wildcard_translator grub_filename_translator = {
+  .expand = wildcard_expand,
+  .escape = wildcard_escape,
+  .unescape = wildcard_unescape
+};
+
+static char **
+merge (char **dest, char **ps)
+{
+  int i;
+  int j;
+  char **p;
+
+  if (! dest)
+    return ps;
+
+  if (! ps)
+    return dest;
+
+  for (i = 0; dest[i]; i++)
+    ;
+  for (j = 0; ps[j]; j++)
+    ;
+
+  p = grub_realloc (dest, sizeof (char*) * (i + j + 1));
+  if (! p)
+    {
+      grub_free (dest);
+      grub_free (ps);
+      return 0;
+    }
+
+  dest = p;
+  for (j = 0; ps[j]; j++)
+    dest[i++] = ps[j];
+  dest[i] = 0;
+
+  grub_free (ps);
+  return dest;
+}
+
+static inline int
+isregexop (char ch)
+{
+  return grub_strchr ("*.\\", ch) ? 1 : 0;
+}
+
+static char *
+make_dir (const char *prefix, const char *start, const char *end)
+{
+  char ch;
+  unsigned i;
+  unsigned n;
+  char *result;
+
+  i = grub_strlen (prefix);
+  n = i + end - start;
+
+  result = grub_malloc (n + 1);
+  if (! result)
+    return 0;
+
+  grub_strcpy (result, prefix);
+  while (start < end && (ch = *start++))
+    if (ch == '\\' && isregexop (*start))
+      result[i++] = *start++;
+    else
+      result[i++] = ch;
+
+  result[i] = '\0';
+  return result;
+}
+
+static int
+make_regex (const char *start, const char *end, regex_t *regexp)
+{
+  char ch;
+  int i = 0;
+  unsigned len = end - start;
+  char *buffer = grub_malloc (len * 2 + 2 + 1); /* worst case size. */
+
+  if (! buffer)
+    return 1;
+
+  buffer[i++] = '^';
+  while (start < end)
+    {
+      /* XXX Only * expansion for now.  */
+      switch ((ch = *start++))
+	{
+	case '\\':
+	  buffer[i++] = ch;
+	  if (*start != '\0')
+	    buffer[i++] = *start++;
+	  break;
+
+	case '.':
+	  buffer[i++] = '\\';
+	  buffer[i++] = '.';
+	  break;
+
+	case '*':
+	  buffer[i++] = '.';
+	  buffer[i++] = '*';
+	  break;
+
+	default:
+	  buffer[i++] = ch;
+	}
+    }
+  buffer[i++] = '$';
+  buffer[i] = '\0';
+
+  if (regcomp (regexp, buffer, RE_SYNTAX_GNU_AWK))
+    {
+      grub_free (buffer);
+      return 1;
+    }
+
+  grub_free (buffer);
+  return 0;
+}
+
+/* Split `str' into two parts: (1) dirname that is regexop free (2)
+   dirname that has a regexop.  */
+static void
+split_path (const char *str, const char **noregexop, const char **regexop)
+{
+  char ch = 0;
+  int regex = 0;
+
+  const char *end;
+  const char *split;  /* points till the end of dirnaname that doesn't
+			 need expansion.  */
+
+  split = end = str;
+  while ((ch = *end))
+    {
+      if (ch == '\\' && end[1])
+	end++;
+
+      else if (isregexop (ch))
+	regex = 1;
+
+      else if (ch == '/' && ! regex)
+	split = end + 1;  /* forward to next regexop-free dirname */
+
+      else if (ch == '/' && regex)
+	break;  /* stop at the first dirname with a regexop */
+
+      end++;
+    }
+
+  *regexop = end;
+  if (! regex)
+    *noregexop = end;
+  else
+    *noregexop = split;
+}
+
+static char **
+match_devices (const regex_t *regexp, int noparts)
+{
+  int i;
+  int ndev;
+  char **devs;
+
+  auto int match (const char *name);
+  int match (const char *name)
+  {
+    char **t;
+    char *buffer;
+
+    /* skip partitions if asked to. */
+    if (noparts && grub_strchr(name, ','))
+      return 0;
+
+    buffer = grub_xasprintf ("(%s)", name);
+    if (! buffer)
+      return 1;
+
+    grub_dprintf ("expand", "matching: %s\n", buffer);
+    if (regexec (regexp, buffer, 0, 0, 0))
+      {
+	grub_free (buffer);
+	return 0;
+      }
+
+    t = grub_realloc (devs, sizeof (char*) * (ndev + 2));
+    if (! t)
+      return 1;
+
+    devs = t;
+    devs[ndev++] = buffer;
+    devs[ndev] = 0;
+    return 0;
+  }
+
+  ndev = 0;
+  devs = 0;
+
+  if (grub_device_iterate (match))
+    goto fail;
+
+  return devs;
+
+ fail:
+
+  for (i = 0; devs && devs[i]; i++)
+    grub_free (devs[i]);
+
+  if (devs)
+    grub_free (devs);
+
+  return 0;
+}
+
+static char **
+match_files (const char *prefix, const char *suffix, const char *end,
+	     const regex_t *regexp)
+{
+  int i;
+  int error;
+  char **files;
+  unsigned nfile;
+  char *dir;
+  const char *path;
+  char *device_name;
+  grub_fs_t fs;
+  grub_device_t dev;
+
+  auto int match (const char *name, const struct grub_dirhook_info *info);
+  int match (const char *name, const struct grub_dirhook_info *info)
+  {
+    char **t;
+    char *buffer;
+
+    /* skip . and .. names */
+    if (grub_strcmp(".", name) == 0 || grub_strcmp("..", name) == 0)
+      return 0;
+
+    grub_dprintf ("expand", "matching: %s in %s\n", name, dir);
+    if (regexec (regexp, name, 0, 0, 0))
+      return 0;
+
+    buffer = grub_xasprintf ("%s%s", dir, name);
+    if (! buffer)
+      return 1;
+
+    t = grub_realloc (files, sizeof (char*) * (nfile + 2));
+    if (! t)
+      {
+	grub_free (buffer);
+	return 1;
+      }
+
+    files = t;
+    files[nfile++] = buffer;
+    files[nfile] = 0;
+    return 0;
+  }
+
+  nfile = 0;
+  files = 0;
+  dev = 0;
+  device_name = 0;
+  grub_error_push ();
+
+  dir = make_dir (prefix, suffix, end);
+  if (! dir)
+    goto fail;
+
+  device_name = grub_file_get_device_name (dir);
+  dev = grub_device_open (device_name);
+  if (! dev)
+    goto fail;
+
+  fs = grub_fs_probe (dev);
+  if (! fs)
+    goto fail;
+
+  path = grub_strchr (dir, ')');
+  if (! path)
+    goto fail;
+  path++;
+
+  if (fs->dir (dev, path, match))
+    goto fail;
+
+  grub_free (dir);
+  grub_device_close (dev);
+  grub_free (device_name);
+  grub_error_pop ();
+  return files;
+
+ fail:
+
+  if (dir)
+    grub_free (dir);
+
+  for (i = 0; files && files[i]; i++)
+    grub_free (files[i]);
+
+  if (files)
+    grub_free (files);
+
+  if (dev)
+    grub_device_close (dev);
+
+  if (device_name)
+    grub_free (device_name);
+
+  grub_error_pop ();
+  return 0;
+}
+
+static char*
+wildcard_escape (const char *s)
+{
+  int i;
+  int len;
+  char ch;
+  char *p;
+
+  len = grub_strlen (s);
+  p = grub_malloc (len * 2 + 1);
+  if (! p)
+    return NULL;
+
+  i = 0;
+  while ((ch = *s++))
+    {
+      if (isregexop (ch))
+	p[i++] = '\\';
+      p[i++] = ch;
+    }
+  p[i] = '\0';
+  return p;
+}
+
+static char*
+wildcard_unescape (const char *s)
+{
+  int i;
+  int len;
+  char ch;
+  char *p;
+
+  len = grub_strlen (s);
+  p = grub_malloc (len + 1);
+  if (! p)
+    return NULL;
+
+  i = 0;
+  while ((ch = *s++))
+    {
+      if (ch == '\\' && isregexop (*s))
+	p[i++] = *s++;
+      else
+	p[i++] = ch;
+    }
+  p[i] = '\0';
+  return p;
+}
+
+static grub_err_t
+wildcard_expand (const char *s, char ***strs)
+{
+  const char *start;
+  const char *regexop;
+  const char *noregexop;
+  char **paths = 0;
+
+  unsigned i;
+  regex_t regexp;
+
+  start = s;
+  while (*start)
+    {
+      split_path (start, &noregexop, &regexop);
+      if (noregexop >= regexop) /* no more wildcards */
+	break;
+
+      if (make_regex (noregexop, regexop, &regexp))
+	goto fail;
+
+      if (paths == 0)
+	{
+	  if (start == noregexop) /* device part has regexop */
+	    paths = match_devices (&regexp, *start != '(');
+
+	  else if (*start == '(') /* device part explicit wo regexop */
+	    paths = match_files ("", start, noregexop, &regexp);
+
+	  else if (*start == '/') /* no device part */
+	    {
+	      char **r;
+	      unsigned n;
+	      char *root;
+	      char *prefix;
+
+	      root = grub_env_get ("root");
+	      if (! root)
+		goto fail;
+
+	      prefix = grub_xasprintf ("(%s)", root);
+	      if (! prefix)
+		goto fail;
+
+	      paths = match_files (prefix, start, noregexop, &regexp);
+	      grub_free (prefix);
+	    }
+	}
+      else
+	{
+	  char **r = 0;
+
+	  for (i = 0; paths[i]; i++)
+	    {
+	      char **p;
+
+	      p = match_files (paths[i], start, noregexop, &regexp);
+	      if (! p)
+		continue;
+
+	      r = merge (r, p);
+	      if (! r)
+		goto fail;
+	    }
+	  paths = r;
+	}
+
+      regfree (&regexp);
+      if (! paths)
+	goto done;
+
+      start = regexop;
+    }
+
+ done:
+
+  *strs = paths;
+  return 0;
+
+ fail:
+
+  for (i = 0; paths && paths[i]; i++)
+    grub_free (paths[i]);
+  grub_free (paths[i]);
+  regfree (&regexp);
+  return grub_errno;
+}
--- a/grub-core/script/argv.c
+++ b/grub-core/script/argv.c
@ -102,7 +102,8 @@ grub_script_argv_next (struct grub_script_argv *argv)
 int
 grub_script_argv_append (struct grub_script_argv *argv, const char *s)
 {
-  int a, b;
+  int a;
+  int b;
  char *p = argv->args[argv->argc - 1];

  if (! s)
@ -117,6 +118,7 @@ grub_script_argv_append (struct grub_script_argv *argv, const char *s)

  grub_strcpy (p + a, s);
  argv->args[argv->argc - 1] = p;
+
  return 0;
 }

--- a/grub-core/script/execute.c
+++ b/grub-core/script/execute.c
@ -48,6 +48,9 @@ struct grub_script_scope
 };
 static struct grub_script_scope *scope = 0;

+/* Wildcard translator for GRUB script.  */
+struct grub_script_wildcard_translator *grub_wildcard_translator;
+
 static void
 replace_scope (struct grub_script_scope *new_scope)
 {
@ -289,7 +292,7 @@ grub_script_env_set (const char *name, const char *val)
  return grub_env_set (name, val);
 }

-/* Expand arguments in ARGLIST into multiple arguments.  */
+/* Convert arguments in ARGLIST into ARGV form.  */
 static int
 grub_script_arglist_to_argv (struct grub_script_arglist *arglist,
 			     struct grub_script_argv *argv)
@ -299,6 +302,28 @@ grub_script_arglist_to_argv (struct grub_script_arglist *arglist,
  struct grub_script_arg *arg = 0;
  struct grub_script_argv result = { 0, 0, 0 };

+  auto int append (char *s, int escape_type);
+  int append (char *s, int escape_type)
+  {
+    int r;
+    char *p = 0;
+
+    if (! grub_wildcard_translator || escape_type == 0)
+      return grub_script_argv_append (&result, s);
+
+    if (escape_type > 0)
+      p = grub_wildcard_translator->escape (s);
+    else if (escape_type < 0)
+      p = grub_wildcard_translator->unescape (s);
+
+    if (! p)
+      return 1;
+
+    r = grub_script_argv_append (&result, p);
+    grub_free (p);
+    return r;
+  }
+
  for (; arglist && arglist->arg; arglist = arglist->next)
    {
      if (grub_script_argv_next (&result))
@ -317,8 +342,18 @@ grub_script_arglist_to_argv (struct grub_script_arglist *arglist,
 		  if (i != 0 && grub_script_argv_next (&result))
 		    goto fail;

-		  if (grub_script_argv_append (&result, values[i]))
-		    goto fail;
+		  if (arg->type == GRUB_SCRIPT_ARG_TYPE_VAR)
+		    {
+		      if (grub_script_argv_append (&result, values[i]))
+			goto fail;
+		    }
+		  else
+		    {
+		      if (append (values[i], 1))
+			goto fail;
+		    }
+
+		  grub_free (values[i]);
 		}
 	      grub_free (values);
 	      break;
@ -350,6 +385,51 @@ grub_script_arglist_to_argv (struct grub_script_arglist *arglist,
  if (! result.args[result.argc - 1])
    result.argc--;

+  /* Perform wildcard expansion.  */
+
+  if (grub_wildcard_translator)
+    {
+      int j;
+      int failed = 0;
+      char **expansions = 0;
+      struct grub_script_argv unexpanded = result;
+
+      result.argc = 0;
+      result.args = 0;
+      for (i = 0; unexpanded.args[i]; i++)
+	{
+	  if (grub_wildcard_translator->expand (unexpanded.args[i],
+						&expansions))
+	    {
+	      grub_script_argv_free (&unexpanded);
+	      goto fail;
+	    }
+
+	  if (! expansions)
+	    {
+	      grub_script_argv_next (&result);
+	      append (unexpanded.args[i], -1);
+	    }
+	  else
+	    {
+	      for (j = 0; expansions[j]; j++)
+		{
+		  failed = (failed || grub_script_argv_next (&result) ||
+			    append (expansions[j], -1));
+		  grub_free (expansions[j]);
+		}
+	      grub_free (expansions);
+
+	      if (failed)
+		{
+		  grub_script_argv_free (&unexpanded);
+		  goto fail;
+		}
+	    }
+	}
+      grub_script_argv_free (&unexpanded);
+    }
+
  *argv = result;
  return 0;

--- a/include/grub/script_sh.h
+++ b/include/grub/script_sh.h
@ -81,6 +81,16 @@ struct grub_script_argv
  struct grub_script *script;
 };

+/* Pluggable wildcard translator.  */
+struct grub_script_wildcard_translator
+{
+  char *(*escape) (const char *str);
+  char *(*unescape) (const char *str);
+  grub_err_t (*expand) (const char *str, char ***expansions);
+};
+extern struct grub_script_wildcard_translator *grub_wildcard_translator;
+extern struct grub_script_wildcard_translator grub_filename_translator;
+
 /* A complete argument.  It consists of a list of one or more `struct
   grub_script_arg's.  */
 struct grub_script_arglist
--- a/tests/grub_script_expansion.in
+++ b/tests/grub_script_expansion.in
@ -0,0 +1,42 @@
+#! /bin/bash -e
+
+# Run GRUB script in a Qemu instance
+# Copyright (C) 2010  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
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# GRUB is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+
+disks=`echo ls | @builddir@/grub-shell`
+other=`echo insmod regexp\; echo \* | @builddir@/grub-shell`
+for d in $disks; do
+    if echo "$d" |grep ',' >/dev/null; then
+	if echo "$other" | grep "$d" >/dev/null; then
+	    echo "$d should not occur in * expansion" >&2
+	    exit 1
+	fi
+    else
+	if ! echo "$other" | grep "$d" >/dev/null; then
+	    echo "$d missing from * expansion" >&2
+	    exit 1
+	fi
+    fi
+done
+
+other=`echo insmod regexp\; echo '(*)' | @builddir@/grub-shell`
+for d in $disks; do
+    if ! echo "$other" | grep "$d" >/dev/null; then
+	echo "$d missing from (*) expansion" >&2
+	exit 1
+    fi
+done
+
--- a/tests/util/grub-shell.in
+++ b/tests/util/grub-shell.in
@ -107,7 +107,7 @@ done
 if [ "x${source}" = x ] ; then
    tmpfile=`mktemp`
    while read REPLY; do
-	echo $REPLY >> ${tmpfile}
+	echo "$REPLY" >> ${tmpfile}
    done
    source=${tmpfile}
 fi