platform_bionic/libc/bionic/syslog.cpp
Elliott Hughes 213d943a33 syslog.h: implement LOG_PERROR.
This is the one openlog() flag that toybox uses. We should probably try
to unify toybox's POSIX logger and Android-specific log at some point,
and this will help.

Also fix our behavior with an empty format string, noticed while adding
tests.

Test: treehugger
Test: adb shell logger -s foo
Change-Id: Ic027e78a460be3db83cc4c6f9946c9efa22be6e1
2023-05-03 14:19:40 -07:00

92 lines
2.6 KiB
C++

/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <async_safe/log.h>
static const char* syslog_log_tag = nullptr;
static int syslog_priority_mask = 0xff;
static int syslog_options = 0;
void closelog() {
syslog_log_tag = nullptr;
syslog_options = 0;
}
void openlog(const char* log_tag, int options, int /*facility*/) {
syslog_log_tag = log_tag;
syslog_options = options;
}
int setlogmask(int new_mask) {
int old_mask = syslog_priority_mask;
// 0 is used to query the current mask.
if (new_mask != 0) {
syslog_priority_mask = new_mask;
}
return old_mask;
}
void syslog(int priority, const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vsyslog(priority, fmt, args);
va_end(args);
}
void vsyslog(int priority, const char* fmt, va_list args) {
// Check whether we're supposed to be logging messages of this priority.
if ((syslog_priority_mask & LOG_MASK(LOG_PRI(priority))) == 0) {
return;
}
// What's our log tag?
const char* log_tag = syslog_log_tag;
if (log_tag == nullptr) {
log_tag = getprogname();
}
// What's our Android log priority?
priority &= LOG_PRIMASK;
int android_log_priority;
if (priority <= LOG_ERR) {
android_log_priority = ANDROID_LOG_ERROR;
} else if (priority == LOG_WARNING) {
android_log_priority = ANDROID_LOG_WARN;
} else if (priority <= LOG_INFO) {
android_log_priority = ANDROID_LOG_INFO;
} else {
android_log_priority = ANDROID_LOG_DEBUG;
}
// We can't let async_safe_format_log do the formatting because it doesn't
// support all the printf functionality.
char log_line[1024];
int n = vsnprintf(log_line, sizeof(log_line), fmt, args);
if (n < 0) return;
async_safe_format_log(android_log_priority, log_tag, "%s", log_line);
if ((syslog_options & LOG_PERROR) != 0) {
bool have_newline =
(n > 0 && n < static_cast<int>(sizeof(log_line)) && log_line[n - 1] == '\n');
dprintf(STDERR_FILENO, "%s: %s%s", log_tag, log_line, have_newline ? "" : "\n");
}
}