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 32 void klog_set_level(int level) { 33 klog_level = level; 34 } 35 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 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 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
