Update.

* elf/Makefile (trusted-dirs.st): Use gen-trusted-dirs.awk. * elf/gen-trusted-dirs.awk: New file. * elf/dl-load.c (systems_dirs): Moved into file scope. Initialize from SYSTEM_DIRS macro. (system_dirs_len): New variable. Contains lengths of system_dirs strings. (fillin_rpath): Rewrite for systems_dirs being a simple string. Improve string comparisons. Change parameter trusted to be a flag. Change all callers. (_dt_init_paths): Improve using new format for system_dirs.
1999-05-03 21:59:35 +00:00 · 1999-05-03 21:59:35 +00:00 · ab7eb29230
parent 68536096c8
commit ab7eb29230
4 changed files with 101 additions and 35 deletions
--- a/11
+++ b/11
@ -1,5 +1,16 @@
 1999-05-03  Ulrich Drepper  <drepper@cygnus.com>

+	* elf/Makefile (trusted-dirs.st): Use gen-trusted-dirs.awk.
+	* elf/gen-trusted-dirs.awk: New file.
+	* elf/dl-load.c (systems_dirs): Moved into file scope.  Initialize
+	from SYSTEM_DIRS macro.
+	(system_dirs_len): New variable.  Contains lengths of system_dirs
+	strings.
+	(fillin_rpath): Rewrite for systems_dirs being a simple string.
+	Improve string comparisons.  Change parameter trusted to be a flag.
+	Change all callers.
+	(_dt_init_paths): Improve using new format for system_dirs.
+
 	* elf/dl-load.c (expand_dynamic_string_token): Don't expand
 	$ORIGIN for SUID binaries.

--- a/elf/Makefile
+++ b/elf/Makefile
@ -155,10 +155,8 @@ endif
 $(objpfx)trusted-dirs.h: $(objpfx)trusted-dirs.st; @:
 $(objpfx)trusted-dirs.st: Makefile $(..)Makeconfig
 	$(make-target-directory)
-	dirs="$(subst :, ,$(default-rpath) $(user-defined-trusted-dirs))";   \
-	for dir in $$dirs; do						     \
-	  echo "  \"$$dir/\",";						     \
-	done > ${@:st=T}
+	echo "$(subst :, ,$(default-rpath) $(user-defined-trusted-dirs))"    \
+	| $(AWK) -f gen-trusted-dirs.awk > ${@:st=T};
 	$(move-if-change) ${@:st=T} ${@:st=h}
 	touch $@
 CPPFLAGS-dl-load.c = -I$(objpfx).
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@ -120,6 +120,15 @@ const unsigned char _dl_pf_to_prot[8] =
 };


+/* Get the generated information about the trusted directories.  */
+#include "trusted-dirs.h"
+
+static const char system_dirs[] = SYSTEM_DIRS;
+static const size_t system_dirs_len[] =
+{
+  SYSTEM_DIRS_LEN
+};
+
 /* This function has no public prototype.  */
 extern ssize_t __libc_read (int, void *, size_t);

@ -294,7 +303,7 @@ static size_t max_dirnamelen;

 static inline struct r_search_path_elem **
 fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
-	      const char **trusted, const char *what, const char *where)
+	      int check_trusted, const char *what, const char *where)
 {
  char *cp;
  size_t nelems = 0;
@ -308,38 +317,44 @@ fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
         interpreted as `use the current directory'. */
      if (len == 0)
 	{
-	  static char curwd[] = "./";
-	  cp = curwd;
+	  static const char curwd[] = "./";
+	  cp = (char *) curwd;
 	}

      /* Remove trailing slashes (except for "/").  */
      while (len > 1 && cp[len - 1] == '/')
 	--len;

+      /* Now add one if there is none so far.  */
+      if (len > 0 && cp[len - 1] != '/')
+	cp[len++] = '/';
+
      /* Make sure we don't use untrusted directories if we run SUID.  */
-      if (trusted != NULL)
+      if (check_trusted)
 	{
-	  const char **trun = trusted;
+	  const char *trun = system_dirs;
+	  size_t idx;

 	  /* All trusted directories must be complete names.  */
 	  if (cp[0] != '/')
 	    continue;

-	  while (*trun != NULL
-		 && (memcmp (*trun, cp, len) != 0
-		     || (*trun)[len] != '/'
-		     || (*trun)[len + 1] != '\0'))
-	    ++trun;
+	  for (idx = 0;
+	       idx < sizeof (system_dirs_len) / sizeof (system_dirs_len[0]);
+	       ++idx)
+	    {
+	      if (len == system_dirs_len[idx] && memcmp (trun, cp, len) == 0)
+		/* Found it.  */
+		break;

-	  if (*trun == NULL)
+	      trun += system_dirs_len[idx] + 1;
+	    }
+
+	  if (idx == sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
 	    /* It's no trusted directory, skip it.  */
 	    continue;
 	}

-      /* Now add one if there is none so far.  */
-      if (len > 0 && cp[len - 1] != '/')
-	cp[len++] = '/';
-
      /* See if this directory is already known.  */
      for (dirp = all_dirs; dirp != NULL; dirp = dirp->next)
 	if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
@ -455,7 +470,7 @@ decompose_rpath (const char *rpath, struct link_map *l)
  if (result == NULL)
    _dl_signal_error (ENOMEM, NULL, "cannot create cache for search path");

-  return fillin_rpath (copy, result, ":", NULL, "RPATH", where);
+  return fillin_rpath (copy, result, ":", 0, "RPATH", where);
 }


@ -463,12 +478,8 @@ void
 internal_function
 _dl_init_paths (const char *llp)
 {
-  static const char *system_dirs[] =
-  {
-#include "trusted-dirs.h"
-    NULL
-  };
-  const char **strp;
+  size_t idx;
+  const char *strp;
  struct r_search_path_elem *pelem, **aelem;
  size_t round_size;
 #ifdef PIC
@ -484,7 +495,7 @@ _dl_init_paths (const char *llp)

  /* First set up the rest of the default search directory entries.  */
  aelem = rtld_search_dirs = (struct r_search_path_elem **)
-    malloc ((sizeof (system_dirs) / sizeof (system_dirs[0]))
+    malloc ((sizeof (system_dirs_len) / sizeof (system_dirs_len[0]))
 	     * sizeof (struct r_search_path_elem *));
  if (rtld_search_dirs == NULL)
    _dl_signal_error (ENOMEM, NULL, "cannot create search path array");
@ -500,20 +511,21 @@ _dl_init_paths (const char *llp)
    _dl_signal_error (ENOMEM, NULL, "cannot create cache for search path");

  pelem = all_dirs = rtld_search_dirs[0];
-  for (strp = system_dirs; *strp != NULL; ++strp, pelem += round_size)
+  strp = system_dirs;
+  idx = 0;
+
+  do
    {
      size_t cnt;

      *aelem++ = pelem;

-      pelem->next = *(strp + 1) == NULL ? NULL : (pelem + round_size);
-
      pelem->what = "system search path";
      pelem->where = NULL;

-      pelem->dirnamelen = strlen (pelem->dirname = *strp);
-      if (pelem->dirnamelen > max_dirnamelen)
-	max_dirnamelen = pelem->dirnamelen;
+      pelem->dirname = strp;
+      pelem->dirnamelen = system_dirs_len[idx];
+      strp += system_dirs_len[idx] + 1;

      if (pelem->dirname[0] != '/')
 	for (cnt = 0; cnt < ncapstr; ++cnt)
@ -521,7 +533,16 @@ _dl_init_paths (const char *llp)
      else
 	for (cnt = 0; cnt < ncapstr; ++cnt)
 	  pelem->status[cnt] = unknown;
+
+      pelem->next = (++idx == (sizeof (system_dirs_len)
+			       / sizeof (system_dirs_len[0]))
+		     ? NULL : (pelem + round_size));
+
+      pelem += round_size;
    }
+  while (idx < sizeof (system_dirs_len) / sizeof (system_dirs_len[0]));
+
+  max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
  *aelem = NULL;

 #ifdef PIC
@ -565,8 +586,7 @@ _dl_init_paths (const char *llp)
 			  "cannot create cache for search path");

      (void) fillin_rpath (local_strdup (llp), env_path_list, ":;",
-			   __libc_enable_secure ? system_dirs : NULL,
-			   "LD_LIBRARY_PATH", NULL);
+			   __libc_enable_secure, "LD_LIBRARY_PATH", NULL);
    }
 }

--- a/elf/gen-trusted-dirs.awk
+++ b/elf/gen-trusted-dirs.awk
@ -0,0 +1,37 @@
+BEGIN {
+  FS = " ";
+}
+
+{
+  for (i = 1; i <= NF; ++i) {
+    s[cnt++] = $i"/";
+  }
+}
+
+END {
+  printf ("#define SYSTEM_DIRS \\\n");
+
+  printf ("  \"%s\"", s[0]);
+
+  for (i = 1; i < cnt; ++i) {
+    printf (" \"\\0\" \"%s\"", s[i]);
+  }
+
+  printf ("\n\n");
+
+  printf ("#define SYSTEM_DIRS_LEN \\\n");
+
+  printf ("  %d", length (s[0]));
+  m = length (s[0]);
+
+  for (i = 1; i < cnt; ++i) {
+    printf (", %d", length(s[i]));
+    if (length(s[i]) > m) {
+      m = length(s[i]);
+    }
+  }
+
+  printf ("\n\n");
+
+  printf ("#define SYSTEM_DIRS_MAX_LEN\t%d\n", m);
+}