platform_bionic/libc/bionic/syslog.cpp
Elliott Hughes 76f8916b90 Clean up <stdlib.h> slightly.
Interestingly, this mostly involves cleaning up our implementation of
various <string.h> functions.

Change-Id: Ifaef49b5cb997134f7bc0cc31bdac844bdb9e089
2015-01-26 14:28:41 -08:00

122 lines
3.3 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 "private/libc_logging.h"
static const char* syslog_log_tag = NULL;
static int syslog_priority_mask = 0xff;
void closelog() {
syslog_log_tag = NULL;
}
void openlog(const char* log_tag, int /*options*/, int /*facility*/) {
syslog_log_tag = log_tag;
}
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) {
int caller_errno = errno;
// 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 == NULL) {
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;
}
// glibc's printf family support %m directly, but our BSD-based one doesn't.
// If the format string seems to contain "%m", rewrite it.
const char* log_fmt = fmt;
if (strstr(fmt, "%m") != NULL) {
size_t dst_len = 1024;
char* dst = reinterpret_cast<char*>(malloc(dst_len));
log_fmt = dst;
const char* src = fmt;
for (; dst_len > 0 && *src != '\0'; ++src) {
if (*src == '%' && *(src + 1) == 'm') {
// Expand %m.
size_t n = strlcpy(dst, strerror(caller_errno), dst_len);
if (n >= dst_len) {
n = dst_len;
}
dst += n;
dst_len -= n;
++src;
} else if (*src == '%' && *(src + 1) == '%') {
// We need to copy pairs of '%'s so the %m test works.
if (dst_len <= 2) {
break;
}
*dst++ = '%'; --dst_len;
*dst++ = '%'; --dst_len;
++src;
} else {
*dst++ = *src; --dst_len;
}
}
*dst = '\0';
}
// We can't let __libc_format_log do the formatting because it doesn't support
// all the printf functionality.
char log_line[1024];
vsnprintf(log_line, sizeof(log_line), log_fmt, args);
if (log_fmt != fmt) {
free(const_cast<char*>(log_fmt));
}
__libc_format_log(android_log_priority, log_tag, "%s", log_line);
}