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 <cutils/klog.h>
18
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <stdarg.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/stat.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28
29 #include <cutils/android_get_control_file.h>
30
31 static int klog_level = KLOG_INFO_LEVEL;
32
klog_set_level(int level)33 void klog_set_level(int level) {
34 klog_level = level;
35 }
36
__open_klog(void)37 static int __open_klog(void) {
38 static const char kmsg_device[] = "/dev/kmsg";
39
40 int ret = android_get_control_file(kmsg_device);
41 if (ret >= 0) return ret;
42 return TEMP_FAILURE_RETRY(open(kmsg_device, O_WRONLY | O_CLOEXEC));
43 }
44
45 #define LOG_BUF_MAX 512
46
klog_writev(int level,const struct iovec * iov,int iov_count)47 void klog_writev(int level, const struct iovec* iov, int iov_count) {
48 if (level > klog_level) return;
49
50 static int klog_fd = __open_klog();
51 if (klog_fd == -1) return;
52 TEMP_FAILURE_RETRY(writev(klog_fd, iov, iov_count));
53 }
54
klog_write(int level,const char * fmt,...)55 void klog_write(int level, const char* fmt, ...) {
56 if (level > klog_level) return;
57
58 char buf[LOG_BUF_MAX];
59 va_list ap;
60 va_start(ap, fmt);
61 vsnprintf(buf, sizeof(buf), fmt, ap);
62 va_end(ap);
63
64 buf[LOG_BUF_MAX - 1] = 0;
65
66 struct iovec iov[1];
67 iov[0].iov_base = buf;
68 iov[0].iov_len = strlen(buf);
69 klog_writev(level, iov, 1);
70 }
71