glibc/sunrpc/auth_unix.c
Zack Weinberg 4a39c34c4f Change most internal uses of __gettimeofday to __clock_gettime.
Since gettimeofday will shortly be implemented in terms of
clock_gettime on all platforms, internal code should use clock_gettime
directly; in addition to removing a layer of indirection, this will
allow us to remove the PLT-bypass gunk for gettimeofday.  (We can't
quite do that yet, but it'll be coming later in this patch series.)
In many cases, the changed code does fewer conversions.

The changed code always assumes __clock_gettime (CLOCK_REALTIME)
cannot fail.  Most of the call sites were assuming gettimeofday could
not fail, but a few places were checking for errors.  POSIX says
clock_gettime can only fail if the clock constant is invalid or
unsupported, and CLOCK_REALTIME is the one and only clock constant
that's required to be supported.  For consistency I grepped the entire
source tree for any other places that checked for errors from
__clock_gettime (CLOCK_REALTIME), found one, and changed it too.

(For the record, POSIX also says gettimeofday can never fail.)

(It would be nice if we could declare that GNU systems will always
support CLOCK_MONOTONIC as well as CLOCK_REALTIME; there are several
places where we are using CLOCK_REALTIME where _MONOTONIC would be
more appropriate, and/or trying to use _MONOTONIC and then falling
back to _REALTIME.  But the Hurd doesn't support CLOCK_MONOTONIC yet,
and it looks like adding it would involve substantial changes to
gnumach's internals and API.  Oh well.)

A few Hurd-specific files were changed to use __host_get_time instead
of __clock_gettime, as this seemed tidier.  We also assume this cannot
fail.  Skimming the code in gnumach leads me to believe the only way
it could fail is if __mach_host_self also failed, and our
Hurd-specific code consistently assumes that can't happen, so I'm
going with that.

With the exception of support/support_test_main.c, test cases are not
modified, mainly because I didn't want to have to figure out which
test cases were testing gettimeofday specifically.

The definition of GETTIME in sysdeps/generic/memusage.h had a typo and
was not reading tv_sec at all.  I fixed this.  It appears nobody has been
generating malloc traces on a machine that doesn't have a superseding
definition.

There are a whole bunch of places where the code could be simplified
by factoring out timespec subtraction and/or comparison logic, but I
want to keep this patch as mechanical as possible.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
2019-10-30 17:04:10 -03:00

358 lines
9.6 KiB
C

/*
* Copyright (c) 2010, 2011, Oracle America, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
* * Neither the name of the "Oracle America, Inc." nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* auth_unix.c, Implements UNIX style authentication parameters.
*
* The system is very weak. The client uses no encryption for it's
* credentials and only sends null verifiers. The server sends backs
* null verifiers or optionally a verifier that suggests a new short hand
* for the credentials.
*/
#include <errno.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <libintl.h>
#include <sys/param.h>
#include <wchar.h>
#include <shlib-compat.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/auth_unix.h>
/*
* Unix authenticator operations vector
*/
static void authunix_nextverf (AUTH *);
static bool_t authunix_marshal (AUTH *, XDR *);
static bool_t authunix_validate (AUTH *, struct opaque_auth *);
static bool_t authunix_refresh (AUTH *);
static void authunix_destroy (AUTH *);
static const struct auth_ops auth_unix_ops = {
authunix_nextverf,
authunix_marshal,
authunix_validate,
authunix_refresh,
authunix_destroy
};
/*
* This struct is pointed to by the ah_private field of an auth_handle.
*/
struct audata {
struct opaque_auth au_origcred; /* original credentials */
struct opaque_auth au_shcred; /* short hand cred */
u_long au_shfaults; /* short hand cache faults */
char au_marshed[MAX_AUTH_BYTES];
u_int au_mpos; /* xdr pos at end of marshed */
};
#define AUTH_PRIVATE(auth) ((struct audata *)auth->ah_private)
static bool_t marshal_new_auth (AUTH *);
/*
* Create a unix style authenticator.
* Returns an auth handle with the given stuff in it.
*/
AUTH *
authunix_create (char *machname, uid_t uid, gid_t gid, int len,
gid_t *aup_gids)
{
struct authunix_parms aup;
char mymem[MAX_AUTH_BYTES];
struct timespec now;
XDR xdrs;
AUTH *auth;
struct audata *au;
/*
* Allocate and set up auth handle
*/
auth = (AUTH *) mem_alloc (sizeof (*auth));
au = (struct audata *) mem_alloc (sizeof (*au));
if (auth == NULL || au == NULL)
{
no_memory:
(void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
mem_free (auth, sizeof (*auth));
mem_free (au, sizeof (*au));
return NULL;
}
auth->ah_ops = (struct auth_ops *) &auth_unix_ops;
auth->ah_private = (caddr_t) au;
auth->ah_verf = au->au_shcred = _null_auth;
au->au_shfaults = 0;
/*
* fill in param struct from the given params
*/
__clock_gettime (CLOCK_REALTIME, &now);
aup.aup_time = now.tv_sec;
aup.aup_machname = machname;
aup.aup_uid = uid;
aup.aup_gid = gid;
aup.aup_len = (u_int) len;
aup.aup_gids = aup_gids;
/*
* Serialize the parameters into origcred
*/
xdrmem_create (&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
if (!xdr_authunix_parms (&xdrs, &aup))
abort ();
au->au_origcred.oa_length = len = XDR_GETPOS (&xdrs);
au->au_origcred.oa_flavor = AUTH_UNIX;
au->au_origcred.oa_base = mem_alloc ((u_int) len);
if (au->au_origcred.oa_base == NULL)
goto no_memory;
memcpy(au->au_origcred.oa_base, mymem, (u_int) len);
/*
* set auth handle to reflect new cred.
*/
auth->ah_cred = au->au_origcred;
marshal_new_auth (auth);
return auth;
}
libc_hidden_nolink_sunrpc (authunix_create, GLIBC_2_0)
/*
* Returns an auth handle with parameters determined by doing lots of
* syscalls.
*/
AUTH *
authunix_create_default (void)
{
char machname[MAX_MACHINE_NAME + 1];
if (__gethostname (machname, MAX_MACHINE_NAME) == -1)
abort ();
machname[MAX_MACHINE_NAME] = 0;
uid_t uid = __geteuid ();
gid_t gid = __getegid ();
int max_nr_groups;
/* When we have to try a second time, do not use alloca() again. We
might have reached the stack limit already. */
bool retry = false;
again:
/* Ask the kernel how many groups there are exactly. Note that we
might have to redo all this if the number of groups has changed
between the two calls. */
max_nr_groups = __getgroups (0, NULL);
/* Just some random reasonable stack limit. */
#define ALLOCA_LIMIT (1024 / sizeof (gid_t))
gid_t *gids = NULL;
if (max_nr_groups < ALLOCA_LIMIT && ! retry)
gids = (gid_t *) alloca (max_nr_groups * sizeof (gid_t));
else
{
gids = (gid_t *) malloc (max_nr_groups * sizeof (gid_t));
if (gids == NULL)
return NULL;
}
int len = __getgroups (max_nr_groups, gids);
if (len == -1)
{
if (errno == EINVAL)
{
/* New groups added in the meantime. Try again. */
if (max_nr_groups >= ALLOCA_LIMIT || retry)
free (gids);
retry = true;
goto again;
}
/* No other error can happen. */
abort ();
}
/* This braindamaged Sun code forces us here to truncate the
list of groups to NGRPS members since the code in
authuxprot.c transforms a fixed array. Grrr. */
AUTH *result = authunix_create (machname, uid, gid, MIN (NGRPS, len), gids);
if (max_nr_groups >= ALLOCA_LIMIT || retry)
free (gids);
return result;
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (authunix_create_default)
#else
libc_hidden_nolink_sunrpc (authunix_create_default, GLIBC_2_0)
#endif
/*
* authunix operations
*/
static void
authunix_nextverf (AUTH *auth)
{
/* no action necessary */
}
static bool_t
authunix_marshal (AUTH *auth, XDR *xdrs)
{
struct audata *au = AUTH_PRIVATE (auth);
return XDR_PUTBYTES (xdrs, au->au_marshed, au->au_mpos);
}
static bool_t
authunix_validate (AUTH *auth, struct opaque_auth *verf)
{
struct audata *au;
XDR xdrs;
if (verf->oa_flavor == AUTH_SHORT)
{
au = AUTH_PRIVATE (auth);
xdrmem_create (&xdrs, verf->oa_base, verf->oa_length, XDR_DECODE);
if (au->au_shcred.oa_base != NULL)
{
mem_free (au->au_shcred.oa_base,
au->au_shcred.oa_length);
au->au_shcred.oa_base = NULL;
}
if (xdr_opaque_auth (&xdrs, &au->au_shcred))
{
auth->ah_cred = au->au_shcred;
}
else
{
xdrs.x_op = XDR_FREE;
(void) xdr_opaque_auth (&xdrs, &au->au_shcred);
au->au_shcred.oa_base = NULL;
auth->ah_cred = au->au_origcred;
}
marshal_new_auth (auth);
}
return TRUE;
}
static bool_t
authunix_refresh (AUTH *auth)
{
struct audata *au = AUTH_PRIVATE (auth);
struct authunix_parms aup;
struct timespec now;
XDR xdrs;
int stat;
if (auth->ah_cred.oa_base == au->au_origcred.oa_base)
{
/* there is no hope. Punt */
return FALSE;
}
au->au_shfaults++;
/* first deserialize the creds back into a struct authunix_parms */
aup.aup_machname = NULL;
aup.aup_gids = (gid_t *) NULL;
xdrmem_create (&xdrs, au->au_origcred.oa_base,
au->au_origcred.oa_length, XDR_DECODE);
stat = xdr_authunix_parms (&xdrs, &aup);
if (!stat)
goto done;
/* update the time and serialize in place */
__clock_gettime (CLOCK_REALTIME, &now);
aup.aup_time = now.tv_sec;
xdrs.x_op = XDR_ENCODE;
XDR_SETPOS (&xdrs, 0);
stat = xdr_authunix_parms (&xdrs, &aup);
if (!stat)
goto done;
auth->ah_cred = au->au_origcred;
marshal_new_auth (auth);
done:
/* free the struct authunix_parms created by deserializing */
xdrs.x_op = XDR_FREE;
(void) xdr_authunix_parms (&xdrs, &aup);
XDR_DESTROY (&xdrs);
return stat;
}
static void
authunix_destroy (AUTH *auth)
{
struct audata *au = AUTH_PRIVATE (auth);
mem_free (au->au_origcred.oa_base, au->au_origcred.oa_length);
if (au->au_shcred.oa_base != NULL)
mem_free (au->au_shcred.oa_base, au->au_shcred.oa_length);
mem_free (auth->ah_private, sizeof (struct audata));
if (auth->ah_verf.oa_base != NULL)
mem_free (auth->ah_verf.oa_base, auth->ah_verf.oa_length);
mem_free ((caddr_t) auth, sizeof (*auth));
}
/*
* Marshals (pre-serializes) an auth struct.
* sets private data, au_marshed and au_mpos
*/
static bool_t
marshal_new_auth (AUTH *auth)
{
XDR xdr_stream;
XDR *xdrs = &xdr_stream;
struct audata *au = AUTH_PRIVATE (auth);
xdrmem_create (xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
if ((!xdr_opaque_auth (xdrs, &(auth->ah_cred))) ||
(!xdr_opaque_auth (xdrs, &(auth->ah_verf))))
perror (_("auth_unix.c: Fatal marshalling problem"));
else
au->au_mpos = XDR_GETPOS (xdrs);
XDR_DESTROY (xdrs);
return TRUE;
}