Systemd/src/basic/audit-util.c
Zbigniew Jędrzejewski-Szmek 11a1589223 tree-wide: drop license boilerplate
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.

I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
2018-04-06 18:58:55 +02:00

96 lines
2.2 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
***/
#include <errno.h>
#include <linux/netlink.h>
#include <stdio.h>
#include <sys/socket.h>
#include "alloc-util.h"
#include "audit-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "macro.h"
#include "parse-util.h"
#include "process-util.h"
#include "user-util.h"
int audit_session_from_pid(pid_t pid, uint32_t *id) {
_cleanup_free_ char *s = NULL;
const char *p;
uint32_t u;
int r;
assert(id);
/* We don't convert ENOENT to ESRCH here, since we can't
* really distuingish between "audit is not available in the
* kernel" and "the process does not exist", both which will
* result in ENOENT. */
p = procfs_file_alloca(pid, "sessionid");
r = read_one_line_file(p, &s);
if (r < 0)
return r;
r = safe_atou32(s, &u);
if (r < 0)
return r;
if (!audit_session_is_valid(u))
return -ENODATA;
*id = u;
return 0;
}
int audit_loginuid_from_pid(pid_t pid, uid_t *uid) {
_cleanup_free_ char *s = NULL;
const char *p;
uid_t u;
int r;
assert(uid);
p = procfs_file_alloca(pid, "loginuid");
r = read_one_line_file(p, &s);
if (r < 0)
return r;
r = parse_uid(s, &u);
if (r == -ENXIO) /* the UID was -1 */
return -ENODATA;
if (r < 0)
return r;
*uid = u;
return 0;
}
bool use_audit(void) {
static int cached_use = -1;
if (cached_use < 0) {
int fd;
fd = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_AUDIT);
if (fd < 0) {
cached_use = !IN_SET(errno, EAFNOSUPPORT, EPROTONOSUPPORT, EPERM);
if (errno == EPERM)
log_debug_errno(errno, "Audit access prohibited, won't talk to audit");
}
else {
cached_use = true;
safe_close(fd);
}
}
return cached_use;
}