1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 #include <time.h>
29 #include <stdio.h>
30 #include <pthread.h>
31 #include <unistd.h>
32 #include <sys/types.h>
33 #include <sys/uio.h>
34 #include <arpa/inet.h>
35 #include <errno.h>
36 #include <string.h>
37 #include <stdlib.h>
38 #include <stdarg.h>
39 #include <fcntl.h>
40
41 #include "logd.h"
42
43 /* should match system/core/include/cutils/logger.h */
44 #define LOGGER_LOG_MAIN "log/main"
45 #define LOGGER_LOG_RADIO "log/radio"
46 #define LOGGER_LOG_EVENTS "log/events"
47 #define LOGGER_LOG_SYSTEM "log/system"
48
49 #include <pthread.h>
50
51 /* IMPORTANT IMPORTANT IMPORTANT: TECHNICAL NOTE
52 *
53 * Some of the functions below can be called when our malloc() implementation
54 * has detected that the heap is corrupted, or even from a signal handler.
55 *
56 * These functions should *not* use a function that allocates heap memory
57 * or is not signal-safe. Using direct system calls is acceptable, and we
58 * also assume that pthread_mutex_lock/unlock can be used too.
59 */
60
61 #define LOG_BUF_SIZE 1024
62
63 typedef enum {
64 LOG_ID_NONE = 0,
65 LOG_ID_MAIN,
66 LOG_ID_RADIO,
67 LOG_ID_MAX
68 } log_id_t;
69
70 /* logger handles writing to object, pointed by log channel id */
71 typedef int (*logger_function_t)(log_id_t log_id, struct iovec *vec);
72
73 typedef struct {
74 logger_function_t logger;
75 int fd;
76 const char *path;
77 } log_channel_t;
78
79 static int __write_to_log_init(log_id_t log_id, struct iovec *vec);
80 static int __write_to_log_null(log_id_t log_id, struct iovec *vec);
81
82 static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
83
84 static log_channel_t log_channels[LOG_ID_MAX] = {
85 { __write_to_log_null, -1, NULL },
86 { __write_to_log_init, -1, "/dev/"LOGGER_LOG_MAIN },
87 { __write_to_log_init, -1, "/dev/"LOGGER_LOG_RADIO }
88 };
89
90 /* Important: see technical note at start of source file */
__write_to_log_null(log_id_t log_id,struct iovec * vec)91 static int __write_to_log_null(log_id_t log_id, struct iovec *vec)
92 {
93 /*
94 * ALTERED behaviour from previous version
95 * always returns successful result
96 */
97 int i = 0;
98 size_t res = 0;
99
100 for ( ; i < 3; ++i) {
101 res += vec[i].iov_len;
102 }
103
104 return (int)res;
105 }
106
107 /*
108 * it's supposed, that log_id contains valid id always.
109 * this check must be performed in higher level functions
110 */
111 /* Important: see technical note at start of source file */
__write_to_log_kernel(log_id_t log_id,struct iovec * vec)112 static int __write_to_log_kernel(log_id_t log_id, struct iovec *vec)
113 {
114 return TEMP_FAILURE_RETRY( writev(log_channels[log_id].fd, vec, 3) );
115 }
116
117 /* Important: see technical note at start of source file */
__write_to_log_init(log_id_t log_id,struct iovec * vec)118 static int __write_to_log_init(log_id_t log_id, struct iovec *vec)
119 {
120 if ((LOG_ID_NONE < log_id) && (log_id < LOG_ID_MAX)) {
121 int fd;
122
123 pthread_mutex_lock(&log_init_lock);
124
125 fd = TEMP_FAILURE_RETRY(open(log_channels[log_id].path, O_WRONLY));
126
127 log_channels[log_id].logger =
128 (fd < 0) ? __write_to_log_null : __write_to_log_kernel;
129 log_channels[log_id].fd = fd;
130
131 log_channels[log_id].fd = fd;
132
133 pthread_mutex_unlock(&log_init_lock);
134
135 return log_channels[log_id].logger(log_id, vec);
136 }
137
138 /* log_id is invalid */
139 return -1;
140 }
141
142 /* Important: see technical note at start of source file */
143 __LIBC_HIDDEN__
__libc_android_log_write(int prio,const char * tag,const char * msg)144 int __libc_android_log_write(int prio, const char *tag, const char *msg)
145 {
146 struct iovec vec[3];
147 log_id_t log_id = LOG_ID_MAIN;
148
149 if (tag == NULL)
150 tag = "";
151
152 if (!strcmp(tag, "HTC_RIL"))
153 log_id = LOG_ID_RADIO;
154
155 vec[0].iov_base = (unsigned char *) &prio;
156 vec[0].iov_len = 1;
157 vec[1].iov_base = (void *) tag;
158 vec[1].iov_len = strlen(tag) + 1;
159 vec[2].iov_base = (void *) msg;
160 vec[2].iov_len = strlen(msg) + 1;
161
162 return log_channels[log_id].logger(log_id, vec);
163 }
164
165 /* The functions below are not designed to be called from a heap panic
166 * function or from a signal handler. As such, they are free to use complex
167 * C library functions like vsnprintf()
168 */
169 __LIBC_HIDDEN__
__libc_android_log_vprint(int prio,const char * tag,const char * fmt,va_list ap)170 int __libc_android_log_vprint(int prio, const char *tag, const char *fmt,
171 va_list ap)
172 {
173 char buf[LOG_BUF_SIZE];
174
175 vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
176
177 return __libc_android_log_write(prio, tag, buf);
178 }
179
180 __LIBC_HIDDEN__
__libc_android_log_print(int prio,const char * tag,const char * fmt,...)181 int __libc_android_log_print(int prio, const char *tag, const char *fmt, ...)
182 {
183 va_list ap;
184 char buf[LOG_BUF_SIZE];
185
186 va_start(ap, fmt);
187 vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
188 va_end(ap);
189
190 return __libc_android_log_write(prio, tag, buf);
191 }
192
193 __LIBC_HIDDEN__
__libc_android_log_assert(const char * cond,const char * tag,const char * fmt,...)194 int __libc_android_log_assert(const char *cond, const char *tag,
195 const char *fmt, ...)
196 {
197 va_list ap;
198 char buf[LOG_BUF_SIZE];
199
200 va_start(ap, fmt);
201 vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
202 va_end(ap);
203
204 __libc_android_log_write(ANDROID_LOG_FATAL, tag, buf);
205
206 exit(1);
207
208 return -1;
209 }
210