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 <errno.h>
18 #include <fcntl.h>
19 #include <stdarg.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sys/stat.h>
24 #include <sys/types.h>
25 #include <unistd.h>
26
27 #include <cutils/android_get_control_file.h>
28 #include <cutils/klog.h>
29
30 static int klog_level = KLOG_INFO_LEVEL;
31
klog_set_level(int level)32 void klog_set_level(int level) {
33 klog_level = level;
34 }
35
__open_klog(void)36 static int __open_klog(void) {
37 static const char kmsg_device[] = "/dev/kmsg";
38
39 int ret = android_get_control_file(kmsg_device);
40 if (ret >= 0) return ret;
41 return TEMP_FAILURE_RETRY(open(kmsg_device, O_WRONLY | O_CLOEXEC));
42 }
43
44 #define LOG_BUF_MAX 512
45
klog_writev(int level,const struct iovec * iov,int iov_count)46 void klog_writev(int level, const struct iovec* iov, int iov_count) {
47 if (level > klog_level) return;
48
49 static int klog_fd = __open_klog();
50 if (klog_fd == -1) return;
51 TEMP_FAILURE_RETRY(writev(klog_fd, iov, iov_count));
52 }
53
klog_write(int level,const char * fmt,...)54 void klog_write(int level, const char* fmt, ...) {
55 if (level > klog_level) return;
56
57 char buf[LOG_BUF_MAX];
58 va_list ap;
59 va_start(ap, fmt);
60 vsnprintf(buf, sizeof(buf), fmt, ap);
61 va_end(ap);
62
63 buf[LOG_BUF_MAX - 1] = 0;
64
65 struct iovec iov[1];
66 iov[0].iov_base = buf;
67 iov[0].iov_len = strlen(buf);
68 klog_writev(level, iov, 1);
69 }
70