From 430f0182b72373145c839dbfe99d2382855cb8f8 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Mon, 26 Oct 2015 23:32:16 +0100 Subject: src/basic: rename audit.[ch] → audit-util.[ch] and capability.[ch] → capability-util.[ch] MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The files are named too generically, so that they might conflict with the upstream project headers. Hence, let's add a "-util" suffix, to clarify that this are just our utility headers and not any official upstream headers. --- src/basic/capability.c | 308 ------------------------------------------------- 1 file changed, 308 deletions(-) delete mode 100644 src/basic/capability.c (limited to 'src/basic/capability.c') diff --git a/src/basic/capability.c b/src/basic/capability.c deleted file mode 100644 index 04c7047a6a..0000000000 --- a/src/basic/capability.c +++ /dev/null @@ -1,308 +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 . -***/ - -#include -#include -#include -#include -#include -#include - -#include "capability.h" -#include "fileio.h" -#include "log.h" -#include "macro.h" -#include "parse-util.h" -#include "util.h" - -int have_effective_cap(int value) { - _cleanup_cap_free_ cap_t cap; - cap_flag_value_t fv; - - cap = cap_get_proc(); - if (!cap) - return -errno; - - if (cap_get_flag(cap, value, CAP_EFFECTIVE, &fv) < 0) - return -errno; - else - return fv == CAP_SET; -} - -unsigned long cap_last_cap(void) { - static thread_local unsigned long saved; - static thread_local bool valid = false; - _cleanup_free_ char *content = NULL; - unsigned long p = 0; - int r; - - if (valid) - return saved; - - /* available since linux-3.2 */ - r = read_one_line_file("/proc/sys/kernel/cap_last_cap", &content); - if (r >= 0) { - r = safe_atolu(content, &p); - if (r >= 0) { - saved = p; - valid = true; - return p; - } - } - - /* fall back to syscall-probing for pre linux-3.2 */ - 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) { - _cleanup_cap_free_ cap_t after_cap = NULL; - cap_flag_value_t fv; - unsigned long i; - 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) - return -errno; - - if (fv != CAP_SET) { - _cleanup_cap_free_ cap_t temp_cap = NULL; - 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 = (cap_value_t) 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 (cap_set_proc(after_cap) < 0) - return -errno; - - 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_string_file(fn, p, WRITE_STRING_FILE_CREATE); - 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; -} - -int drop_privileges(uid_t uid, gid_t gid, uint64_t keep_capabilities) { - _cleanup_cap_free_ cap_t d = NULL; - unsigned i, j = 0; - int r; - - /* Unfortunately we cannot leave privilege dropping to PID 1 - * here, since we want to run as user but want to keep some - * capabilities. Since file capabilities have been introduced - * this cannot be done across exec() anymore, unless our - * binary has the capability configured in the file system, - * which we want to avoid. */ - - if (setresgid(gid, gid, gid) < 0) - return log_error_errno(errno, "Failed to change group ID: %m"); - - if (setgroups(0, NULL) < 0) - return log_error_errno(errno, "Failed to drop auxiliary groups list: %m"); - - /* Ensure we keep the permitted caps across the setresuid() */ - if (prctl(PR_SET_KEEPCAPS, 1) < 0) - return log_error_errno(errno, "Failed to enable keep capabilities flag: %m"); - - r = setresuid(uid, uid, uid); - if (r < 0) - return log_error_errno(errno, "Failed to change user ID: %m"); - - if (prctl(PR_SET_KEEPCAPS, 0) < 0) - return log_error_errno(errno, "Failed to disable keep capabilities flag: %m"); - - /* Drop all caps from the bounding set, except the ones we want */ - r = capability_bounding_set_drop(~keep_capabilities, true); - if (r < 0) - return log_error_errno(r, "Failed to drop capabilities: %m"); - - /* Now upgrade the permitted caps we still kept to effective caps */ - d = cap_init(); - if (!d) - return log_oom(); - - if (keep_capabilities) { - cap_value_t bits[u64log2(keep_capabilities) + 1]; - - for (i = 0; i < ELEMENTSOF(bits); i++) - if (keep_capabilities & (1ULL << i)) - bits[j++] = i; - - /* use enough bits */ - assert(i == 64 || (keep_capabilities >> i) == 0); - /* don't use too many bits */ - assert(keep_capabilities & (1ULL << (i - 1))); - - if (cap_set_flag(d, CAP_EFFECTIVE, j, bits, CAP_SET) < 0 || - cap_set_flag(d, CAP_PERMITTED, j, bits, CAP_SET) < 0) { - log_error_errno(errno, "Failed to enable capabilities bits: %m"); - return -errno; - } - - if (cap_set_proc(d) < 0) - return log_error_errno(errno, "Failed to increase capabilities: %m"); - } - - return 0; -} - -int drop_capability(cap_value_t cv) { - _cleanup_cap_free_ cap_t tmp_cap = NULL; - - tmp_cap = cap_get_proc(); - if (!tmp_cap) - return -errno; - - if ((cap_set_flag(tmp_cap, CAP_INHERITABLE, 1, &cv, CAP_CLEAR) < 0) || - (cap_set_flag(tmp_cap, CAP_PERMITTED, 1, &cv, CAP_CLEAR) < 0) || - (cap_set_flag(tmp_cap, CAP_EFFECTIVE, 1, &cv, CAP_CLEAR) < 0)) - return -errno; - - if (cap_set_proc(tmp_cap) < 0) - return -errno; - - return 0; -} -- cgit v1.2.3-54-g00ecf