87 lines
2.2 KiB
C
87 lines
2.2 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <assert.h>
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#include <stdio.h>
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#include <sys/types.h>
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#include <stdarg.h>
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#include <ctype.h>
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#include <sys/capability.h>
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#include <sys/prctl.h>
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#include "macro.h"
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#include "capability.h"
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#include "util.h"
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#include "log.h"
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int have_effective_cap(int value) {
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cap_t cap;
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cap_flag_value_t fv;
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int r;
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if (!(cap = cap_get_proc()))
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return -errno;
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if (cap_get_flag(cap, value, CAP_EFFECTIVE, &fv) < 0)
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r = -errno;
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else
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r = fv == CAP_SET;
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cap_free(cap);
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return r;
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}
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unsigned long cap_last_cap(void) {
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static __thread unsigned long saved;
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static __thread bool valid = false;
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unsigned long p;
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if (valid)
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return saved;
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p = (unsigned long) CAP_LAST_CAP;
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if (prctl(PR_CAPBSET_READ, p) < 0) {
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/* Hmm, look downwards, until we find one that
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* works */
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for (p--; p > 0; p --)
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if (prctl(PR_CAPBSET_READ, p) >= 0)
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break;
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} else {
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/* Hmm, look upwards, until we find one that doesn't
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* work */
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for (;; p++)
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if (prctl(PR_CAPBSET_READ, p+1) < 0)
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break;
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}
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saved = p;
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valid = true;
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return p;
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}
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