diff options
Diffstat (limited to 'src/shared/capability.c')
| -rw-r--r-- | src/shared/capability.c | 224 |
1 files changed, 0 insertions, 224 deletions
diff --git a/src/shared/capability.c b/src/shared/capability.c deleted file mode 100644 index 9b743e86d0..0000000000 --- a/src/shared/capability.c +++ /dev/null @@ -1,224 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - Copyright 2010 Lennart Poettering - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -#include <assert.h> -#include <string.h> -#include <unistd.h> -#include <errno.h> -#include <stdio.h> -#include <sys/types.h> -#include <stdarg.h> -#include <ctype.h> -#include <sys/capability.h> -#include <sys/prctl.h> - -#include "macro.h" -#include "capability.h" -#include "util.h" -#include "log.h" - -int have_effective_cap(int value) { - cap_t cap; - cap_flag_value_t fv; - int r; - - cap = cap_get_proc(); - if (!cap) - return -errno; - - if (cap_get_flag(cap, value, CAP_EFFECTIVE, &fv) < 0) - r = -errno; - else - r = fv == CAP_SET; - - cap_free(cap); - return r; -} - -unsigned long cap_last_cap(void) { - static __thread unsigned long saved; - static __thread bool valid = false; - unsigned long p; - - if (valid) - return saved; - - p = (unsigned long) CAP_LAST_CAP; - - if (prctl(PR_CAPBSET_READ, p) < 0) { - - /* Hmm, look downwards, until we find one that - * works */ - for (p--; p > 0; p --) - if (prctl(PR_CAPBSET_READ, p) >= 0) - break; - - } else { - - /* Hmm, look upwards, until we find one that doesn't - * work */ - for (;; p++) - if (prctl(PR_CAPBSET_READ, p+1) < 0) - break; - } - - saved = p; - valid = true; - - return p; -} - -int capability_bounding_set_drop(uint64_t drop, bool right_now) { - unsigned long i; - cap_t after_cap = NULL, temp_cap = NULL; - cap_flag_value_t fv; - int r; - - /* If we are run as PID 1 we will lack CAP_SETPCAP by default - * in the effective set (yes, the kernel drops that when - * executing init!), so get it back temporarily so that we can - * call PR_CAPBSET_DROP. */ - - after_cap = cap_get_proc(); - if (!after_cap) - return -errno; - - if (cap_get_flag(after_cap, CAP_SETPCAP, CAP_EFFECTIVE, &fv) < 0) { - cap_free(after_cap); - return -errno; - } - - if (fv != CAP_SET) { - static const cap_value_t v = CAP_SETPCAP; - - temp_cap = cap_dup(after_cap); - if (!temp_cap) { - r = -errno; - goto finish; - } - - if (cap_set_flag(temp_cap, CAP_EFFECTIVE, 1, &v, CAP_SET) < 0) { - r = -errno; - goto finish; - } - - if (cap_set_proc(temp_cap) < 0) { - r = -errno; - goto finish; - } - } - - for (i = 0; i <= cap_last_cap(); i++) { - - if (drop & ((uint64_t) 1ULL << (uint64_t) i)) { - cap_value_t v; - - /* Drop it from the bounding set */ - if (prctl(PR_CAPBSET_DROP, i) < 0) { - r = -errno; - goto finish; - } - v = i; - - /* Also drop it from the inheritable set, so - * that anything we exec() loses the - * capability for good. */ - if (cap_set_flag(after_cap, CAP_INHERITABLE, 1, &v, CAP_CLEAR) < 0) { - r = -errno; - goto finish; - } - - /* If we shall apply this right now drop it - * also from our own capability sets. */ - if (right_now) { - if (cap_set_flag(after_cap, CAP_PERMITTED, 1, &v, CAP_CLEAR) < 0 || - cap_set_flag(after_cap, CAP_EFFECTIVE, 1, &v, CAP_CLEAR) < 0) { - r = -errno; - goto finish; - } - } - } - } - - r = 0; - -finish: - if (temp_cap) - cap_free(temp_cap); - - if (after_cap) { - cap_set_proc(after_cap); - cap_free(after_cap); - } - - return r; -} - -static int drop_from_file(const char *fn, uint64_t drop) { - int r, k; - uint32_t hi, lo; - uint64_t current, after; - char *p; - - r = read_one_line_file(fn, &p); - if (r < 0) - return r; - - assert_cc(sizeof(hi) == sizeof(unsigned)); - assert_cc(sizeof(lo) == sizeof(unsigned)); - - k = sscanf(p, "%u %u", &lo, &hi); - free(p); - - if (k != 2) - return -EIO; - - current = (uint64_t) lo | ((uint64_t) hi << 32ULL); - after = current & ~drop; - - if (current == after) - return 0; - - lo = (unsigned) (after & 0xFFFFFFFFULL); - hi = (unsigned) ((after >> 32ULL) & 0xFFFFFFFFULL); - - if (asprintf(&p, "%u %u", lo, hi) < 0) - return -ENOMEM; - - r = write_one_line_file(fn, p); - free(p); - - return r; -} - -int capability_bounding_set_drop_usermode(uint64_t drop) { - int r; - - r = drop_from_file("/proc/sys/kernel/usermodehelper/inheritable", drop); - if (r < 0) - return r; - - r = drop_from_file("/proc/sys/kernel/usermodehelper/bset", drop); - if (r < 0) - return r; - - return r; -} |