1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <sys/stat.h>
18#include <sys/types.h>
19#include <fcntl.h>
20#include <stdarg.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <unistd.h>
25
26#include <cutils/klog.h>
27
28static int klog_fd = -1;
29static int klog_level = KLOG_DEFAULT_LEVEL;
30
31void klog_set_level(int level) {
32    klog_level = level;
33}
34
35void klog_init(void)
36{
37    static const char *name = "/dev/__kmsg__";
38
39    if (klog_fd >= 0) return; /* Already initialized */
40
41    if (mknod(name, S_IFCHR | 0600, (1 << 8) | 11) == 0) {
42        klog_fd = open(name, O_WRONLY);
43        if (klog_fd < 0)
44                return;
45        fcntl(klog_fd, F_SETFD, FD_CLOEXEC);
46        unlink(name);
47    }
48}
49
50#define LOG_BUF_MAX 512
51
52void klog_write(int level, const char *fmt, ...)
53{
54    char buf[LOG_BUF_MAX];
55    va_list ap;
56
57    if (level > klog_level) return;
58    if (klog_fd < 0) klog_init();
59    if (klog_fd < 0) return;
60
61    va_start(ap, fmt);
62    vsnprintf(buf, LOG_BUF_MAX, fmt, ap);
63    buf[LOG_BUF_MAX - 1] = 0;
64    va_end(ap);
65    write(klog_fd, buf, strlen(buf));
66}
67