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/* tcap.c - check that pthreads can independently set capabilities */
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/fsuid.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <assert.h>
#include <errno.h>
#include <string.h>
#if HAVE_LIBCAP
#include <sys/capability.h>
#endif
#include <grp.h>
#include "diod_log.h"
#include "test.h"
#if HAVE_LIBCAP
typedef enum { S0, S1, S2, S3, S4, S5 } state_t;
static state_t state = S0;
static pthread_mutex_t state_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t state_cond = PTHREAD_COND_INITIALIZER;
static void
_prtcap (char *s, cap_value_t capflag)
{
cap_t cap;
cap_flag_value_t val;
if (!(cap = cap_get_proc ()))
err_exit ("%s: cap_get_proc", s);
if (cap_get_flag (cap, capflag, CAP_EFFECTIVE, &val) < 0)
err_exit ("%s: cap_get_flag", s);
if (cap_free (cap) < 0)
err_exit ("%s: cap_free", s);
msg ("%s: cap is %s", s, val == CAP_SET ? "set" : "clear");
}
static void
_setcap (char *s, cap_value_t capflag)
{
cap_t cap;
if (!(cap = cap_get_proc ()))
err_exit ("%s: cap_get_proc", s);
if (cap_set_flag (cap, CAP_EFFECTIVE, 1, &capflag, CAP_SET) < 0)
err_exit ("%s: cap_set_flag", s);
if (cap_set_proc (cap) < 0)
err_exit ("%s: cap_set_proc", s);
if (cap_free (cap) < 0)
err_exit ("%s: cap_free", s);
}
static void
_clrcap (char *s, cap_value_t capflag)
{
cap_t cap;
if (!(cap = cap_get_proc ()))
err_exit ("%s: cap_get_proc", s);
if (cap_set_flag (cap, CAP_EFFECTIVE, 1, &capflag, CAP_CLEAR) < 0)
err_exit ("%s: cap_set_flag", s);
if (cap_set_proc (cap) < 0)
err_exit ("%s: cap_set_proc", s);
if (cap_free (cap) < 0)
err_exit ("%s: cap_free", s);
}
static void
change_state (state_t s)
{
_lock (&state_lock);
state = s;
_condsig (&state_cond);
_unlock (&state_lock);
}
static void
wait_state (state_t s)
{
_lock (&state_lock);
while ((state != s))
_condwait (&state_cond, &state_lock);
_unlock (&state_lock);
}
static void *proc1 (void *a)
{
_prtcap ("task1", CAP_DAC_OVERRIDE); /* 1) task 1, expect clr */
_prtcap ("task1", CAP_CHOWN);
change_state (S1);
wait_state (S2);
_prtcap ("task1", CAP_DAC_OVERRIDE); /* 4) task 1, still clr */
_prtcap ("task1", CAP_CHOWN);
msg ("task1: clr cap");
_clrcap ("task1", CAP_DAC_OVERRIDE);
change_state (S3);
wait_state (S4);
return NULL;
}
static void *proc2 (void *a)
{
wait_state (S1);
_prtcap ("task2", CAP_DAC_OVERRIDE); /* 2) task 2, expect clr */
_prtcap ("task2", CAP_CHOWN);
msg ("task2: set cap");
_setcap ("task2", CAP_DAC_OVERRIDE);
_setcap ("task2", CAP_CHOWN);
_prtcap ("task2", CAP_DAC_OVERRIDE); /* 3) task 2, expect set */
_prtcap ("task2", CAP_CHOWN);
change_state (S2);
wait_state (S3);
_prtcap ("task2", CAP_DAC_OVERRIDE); /* 5) task 2, expect set */
_prtcap ("task2", CAP_CHOWN);
change_state (S4);
return NULL;
}
#endif
int main(int argc, char *argv[])
{
#if HAVE_LIBCAP
pthread_t t1, t2;
assert (geteuid () == 0);
diod_log_init (argv[0]);
_prtcap ("task0", CAP_DAC_OVERRIDE); /* root, expect set */
_prtcap ("task0", CAP_CHOWN);
msg ("task0: setfsuid 1");
setfsuid (1);
_prtcap ("task0", CAP_DAC_OVERRIDE); /* non-root, expect clr */
_prtcap ("task0", CAP_CHOWN);
msg ("task0: setfsuid 0"); /* root, expect set */
setfsuid (0);
_prtcap ("task0", CAP_DAC_OVERRIDE);
_prtcap ("task0", CAP_CHOWN);
msg ("task0: setfsuid 1");
setfsuid (1);
_prtcap ("task0", CAP_DAC_OVERRIDE); /* non-root, expect clr */
_prtcap ("task0", CAP_CHOWN);
msg ("task0: set cap");
_setcap ("task0", CAP_DAC_OVERRIDE);
_setcap ("task0", CAP_CHOWN);
_prtcap ("task0", CAP_DAC_OVERRIDE); /* root with cap explicitly set, */
_prtcap ("task0", CAP_CHOWN); /* expect set */
msg ("task0: setfsuid 2");
setfsuid (2);
_prtcap ("task0", CAP_DAC_OVERRIDE);/* non-root with cap explicitly set, */
_prtcap ("task0", CAP_CHOWN); /* (as root) expect set */
msg ("task0: clr cap");
_clrcap ("task0", CAP_DAC_OVERRIDE);
_clrcap ("task0", CAP_CHOWN);
_prtcap ("task0", CAP_DAC_OVERRIDE);/* non-root with cap explicitly clr, */
_prtcap ("task0", CAP_CHOWN); /* (as non-root) expect clr */
_create (&t1, proc1, NULL);
_create (&t2, proc2, NULL);
_join (t2, NULL);
_join (t1, NULL);
_prtcap ("task0", CAP_DAC_OVERRIDE); /* after threads, expect clr */
_prtcap ("task0", CAP_CHOWN);
#else
fprintf (stderr, "libcap unavailable\n");
exit (77);
#endif
exit (0);
}
/*
* vi:tabstop=4 shiftwidth=4 expandtab
*/
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