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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.
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Ulrich Drepper committed May 3, 1999
1 parent 6853609 commit ab7eb29
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Showing 4 changed files with 101 additions and 35 deletions.
11 changes: 11 additions & 0 deletions ChangeLog
@@ -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.

Expand Down
6 changes: 2 additions & 4 deletions elf/Makefile
Expand Up @@ -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).
Expand Down
82 changes: 51 additions & 31 deletions elf/dl-load.c
Expand Up @@ -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);

Expand Down Expand Up @@ -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;
Expand All @@ -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;

trun += system_dirs_len[idx] + 1;
}

if (*trun == NULL)
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)
Expand Down Expand Up @@ -455,20 +470,16 @@ 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);
}


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
Expand All @@ -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");
Expand All @@ -500,28 +511,38 @@ _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)
pelem->status[cnt] = existing;
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
Expand Down Expand Up @@ -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);
}
}

Expand Down
37 changes: 37 additions & 0 deletions 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);
}

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