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/*-*- 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 <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/capability.h>
#include <sys/statvfs.h>
#include <fnmatch.h>
#include "sd-id128.h"
#include "util.h"
#include "condition.h"
#include "virt.h"
#include "path-util.h"
#include "fileio.h"
#include "unit.h"
#include "smack-util.h"
#include "apparmor-util.h"
#include "ima-util.h"
#include "selinux-util.h"
static bool condition_test_security(Condition *c) {
assert(c);
assert(c->parameter);
assert(c->type == CONDITION_SECURITY);
if (streq(c->parameter, "selinux"))
return use_selinux() == !c->negate;
if (streq(c->parameter, "apparmor"))
return use_apparmor() == !c->negate;
if (streq(c->parameter, "ima"))
return use_ima() == !c->negate;
if (streq(c->parameter, "smack"))
return use_smack() == !c->negate;
return c->negate;
}
static bool condition_test_capability(Condition *c) {
_cleanup_fclose_ FILE *f = NULL;
cap_value_t value;
char line[LINE_MAX];
unsigned long long capabilities = -1;
assert(c);
assert(c->parameter);
assert(c->type == CONDITION_CAPABILITY);
/* If it's an invalid capability, we don't have it */
if (cap_from_name(c->parameter, &value) < 0)
return c->negate;
/* If it's a valid capability we default to assume
* that we have it */
f = fopen("/proc/self/status", "re");
if (!f)
return !c->negate;
while (fgets(line, sizeof(line), f)) {
truncate_nl(line);
if (startswith(line, "CapBnd:")) {
(void) sscanf(line+7, "%llx", &capabilities);
break;
}
}
return !!(capabilities & (1ULL << value)) == !c->negate;
}
static bool condition_test_needs_update(Condition *c) {
const char *p;
struct stat usr, other;
assert(c);
assert(c->parameter);
assert(c->type == CONDITION_NEEDS_UPDATE);
/* If the file system is read-only we shouldn't suggest an update */
if (path_is_read_only_fs(c->parameter) > 0)
return c->negate;
/* Any other failure means we should allow the condition to be true,
* so that we rather invoke too many update tools then too
* few. */
if (!path_is_absolute(c->parameter))
return !c->negate;
p = strappenda(c->parameter, "/.updated");
if (lstat(p, &other) < 0)
return !c->negate;
if (lstat("/usr/", &usr) < 0)
return !c->negate;
return (usr.st_mtim.tv_sec > other.st_mtim.tv_sec ||
(usr.st_mtim.tv_sec == other.st_mtim.tv_sec && usr.st_mtim.tv_nsec > other.st_mtim.tv_nsec)) == !c->negate;
}
static bool condition_test(Condition *c) {
assert(c);
switch(c->type) {
case CONDITION_PATH_EXISTS:
return (access(c->parameter, F_OK) >= 0) == !c->negate;
case CONDITION_PATH_EXISTS_GLOB:
return (glob_exists(c->parameter) > 0) == !c->negate;
case CONDITION_PATH_IS_DIRECTORY: {
struct stat st;
if (stat(c->parameter, &st) < 0)
return c->negate;
return S_ISDIR(st.st_mode) == !c->negate;
}
case CONDITION_PATH_IS_SYMBOLIC_LINK: {
struct stat st;
if (lstat(c->parameter, &st) < 0)
return c->negate;
return S_ISLNK(st.st_mode) == !c->negate;
}
case CONDITION_PATH_IS_MOUNT_POINT:
return (path_is_mount_point(c->parameter, true) > 0) == !c->negate;
case CONDITION_PATH_IS_READ_WRITE:
return (path_is_read_only_fs(c->parameter) > 0) == c->negate;
case CONDITION_DIRECTORY_NOT_EMPTY: {
int k;
k = dir_is_empty(c->parameter);
return !(k == -ENOENT || k > 0) == !c->negate;
}
case CONDITION_FILE_NOT_EMPTY: {
struct stat st;
if (stat(c->parameter, &st) < 0)
return c->negate;
return (S_ISREG(st.st_mode) && st.st_size > 0) == !c->negate;
}
case CONDITION_FILE_IS_EXECUTABLE: {
struct stat st;
if (stat(c->parameter, &st) < 0)
return c->negate;
return (S_ISREG(st.st_mode) && (st.st_mode & 0111)) == !c->negate;
}
case CONDITION_KERNEL_COMMAND_LINE:
return condition_test_kernel_command_line(c);
case CONDITION_VIRTUALIZATION:
return condition_test_virtualization(c);
case CONDITION_SECURITY:
return condition_test_security(c);
case CONDITION_CAPABILITY:
return condition_test_capability(c);
case CONDITION_HOST:
return condition_test_host(c);
case CONDITION_AC_POWER:
return condition_test_ac_power(c);
case CONDITION_ARCHITECTURE:
return condition_test_architecture(c);
case CONDITION_NEEDS_UPDATE:
return condition_test_needs_update(c);
case CONDITION_NULL:
return !c->negate;
default:
assert_not_reached("Invalid condition type.");
}
}
bool condition_test_list(const char *unit, Condition *first) {
Condition *c;
int triggered = -1;
/* If the condition list is empty, then it is true */
if (!first)
return true;
/* Otherwise, if all of the non-trigger conditions apply and
* if any of the trigger conditions apply (unless there are
* none) we return true */
LIST_FOREACH(conditions, c, first) {
bool b;
b = condition_test(c);
if (unit)
log_debug_unit(unit,
"%s=%s%s%s %s for %s.",
condition_type_to_string(c->type),
c->trigger ? "|" : "",
c->negate ? "!" : "",
c->parameter,
b ? "succeeded" : "failed",
unit);
c->state = b ? 1 : -1;
if (!c->trigger && !b)
return false;
if (c->trigger && triggered <= 0)
triggered = b;
}
return triggered != 0;
}
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