1 /*
2 * Copyright (C) 2014 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 <stdlib.h>
19 #include <string.h>
20 #include <syslog.h>
21
22 #include <async_safe/log.h>
23
24 static const char* syslog_log_tag = nullptr;
25 static int syslog_priority_mask = 0xff;
26
closelog()27 void closelog() {
28 syslog_log_tag = nullptr;
29 }
30
openlog(const char * log_tag,int,int)31 void openlog(const char* log_tag, int /*options*/, int /*facility*/) {
32 syslog_log_tag = log_tag;
33 }
34
setlogmask(int new_mask)35 int setlogmask(int new_mask) {
36 int old_mask = syslog_priority_mask;
37 // 0 is used to query the current mask.
38 if (new_mask != 0) {
39 syslog_priority_mask = new_mask;
40 }
41 return old_mask;
42 }
43
syslog(int priority,const char * fmt,...)44 void syslog(int priority, const char* fmt, ...) {
45 va_list args;
46 va_start(args, fmt);
47 vsyslog(priority, fmt, args);
48 va_end(args);
49 }
50
vsyslog(int priority,const char * fmt,va_list args)51 void vsyslog(int priority, const char* fmt, va_list args) {
52 // Check whether we're supposed to be logging messages of this priority.
53 if ((syslog_priority_mask & LOG_MASK(LOG_PRI(priority))) == 0) {
54 return;
55 }
56
57 // What's our log tag?
58 const char* log_tag = syslog_log_tag;
59 if (log_tag == nullptr) {
60 log_tag = getprogname();
61 }
62
63 // What's our Android log priority?
64 priority &= LOG_PRIMASK;
65 int android_log_priority;
66 if (priority <= LOG_ERR) {
67 android_log_priority = ANDROID_LOG_ERROR;
68 } else if (priority == LOG_WARNING) {
69 android_log_priority = ANDROID_LOG_WARN;
70 } else if (priority <= LOG_INFO) {
71 android_log_priority = ANDROID_LOG_INFO;
72 } else {
73 android_log_priority = ANDROID_LOG_DEBUG;
74 }
75
76 // We can't let async_safe_format_log do the formatting because it doesn't support
77 // all the printf functionality.
78 char log_line[1024];
79 vsnprintf(log_line, sizeof(log_line), fmt, args);
80
81 async_safe_format_log(android_log_priority, log_tag, "%s", log_line);
82 }
83