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
63typedef enum {
64    LOG_ID_NONE = 0,
65    LOG_ID_MAIN,
66    LOG_ID_RADIO,
67    LOG_ID_EVENTS,
68    LOG_ID_MAX
69} log_id_t;
70
71/* logger handles writing to object, pointed by log channel id */
72typedef int (*logger_function_t)(log_id_t log_id, struct iovec *vec);
73
74typedef struct {
75    logger_function_t logger;
76    int               fd;
77    const char        *path;
78} log_channel_t;
79
80static int __write_to_log_init(log_id_t log_id, struct iovec *vec);
81static int __write_to_log_null(log_id_t log_id, struct iovec *vec);
82
83static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
84
85static log_channel_t log_channels[LOG_ID_MAX] = {
86    { __write_to_log_null, -1, NULL },
87    { __write_to_log_init, -1, "/dev/"LOGGER_LOG_MAIN },
88    { __write_to_log_init, -1, "/dev/"LOGGER_LOG_RADIO },
89    { __write_to_log_init, -1, "/dev/"LOGGER_LOG_EVENTS }
90};
91
92/* Important: see technical note at start of source file */
93static int __write_to_log_null(log_id_t log_id, struct iovec *vec)
94{
95    /*
96     * ALTERED behaviour from previous version
97     * always returns successful result
98     */
99    int    i = 0;
100    size_t res = 0;
101
102    for ( ; i < 3; ++i) {
103        res += vec[i].iov_len;
104    }
105
106    return (int)res;
107}
108
109/*
110 *  it's supposed, that log_id contains valid id always.
111 *  this check must be performed in higher level functions
112 */
113/* Important: see technical note at start of source file */
114static int __write_to_log_kernel(log_id_t log_id, struct iovec *vec)
115{
116    return TEMP_FAILURE_RETRY( writev(log_channels[log_id].fd, vec, 3) );
117}
118
119/* Important: see technical note at start of source file */
120static int __write_to_log_init(log_id_t log_id, struct iovec *vec)
121{
122    if ((LOG_ID_NONE < log_id) && (log_id < LOG_ID_MAX)) {
123        int fd;
124
125        pthread_mutex_lock(&log_init_lock);
126
127        fd = TEMP_FAILURE_RETRY(open(log_channels[log_id].path, O_WRONLY));
128
129        log_channels[log_id].logger =
130            (fd < 0) ? __write_to_log_null : __write_to_log_kernel;
131        log_channels[log_id].fd = fd;
132
133        log_channels[log_id].fd = fd;
134
135        pthread_mutex_unlock(&log_init_lock);
136
137        return log_channels[log_id].logger(log_id, vec);
138    }
139
140    /* log_id is invalid */
141    return -1;
142}
143
144/* Important: see technical note at start of source file */
145__LIBC_HIDDEN__
146int __libc_android_log_write(int prio, const char *tag, const char *msg)
147{
148    struct iovec vec[3];
149    log_id_t log_id = LOG_ID_MAIN;
150
151    if (tag == NULL)
152        tag = "";
153
154    if (!strcmp(tag, "HTC_RIL"))
155        log_id = LOG_ID_RADIO;
156
157    vec[0].iov_base   = (unsigned char *) &prio;
158    vec[0].iov_len    = 1;
159    vec[1].iov_base   = (void *) tag;
160    vec[1].iov_len    = strlen(tag) + 1;
161    vec[2].iov_base   = (void *) msg;
162    vec[2].iov_len    = strlen(msg) + 1;
163
164    return log_channels[log_id].logger(log_id, vec);
165}
166
167/* The functions below are not designed to be called from a heap panic
168 * function or from a signal handler. As such, they are free to use complex
169 * C library functions like vsnprintf()
170 */
171__LIBC_HIDDEN__
172int __libc_android_log_vprint(int prio, const char *tag, const char *fmt,
173                              va_list ap)
174{
175    char buf[LOG_BUF_SIZE];
176
177    vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
178
179    return __libc_android_log_write(prio, tag, buf);
180}
181
182__LIBC_HIDDEN__
183int __libc_android_log_print(int prio, const char *tag, const char *fmt, ...)
184{
185    va_list ap;
186    char buf[LOG_BUF_SIZE];
187
188    va_start(ap, fmt);
189    vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
190    va_end(ap);
191
192    return __libc_android_log_write(prio, tag, buf);
193}
194
195__LIBC_HIDDEN__
196int __libc_android_log_assert(const char *cond, const char *tag,
197			      const char *fmt, ...)
198{
199    va_list ap;
200    char buf[LOG_BUF_SIZE];
201
202    va_start(ap, fmt);
203    vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
204    va_end(ap);
205
206    __libc_android_log_write(ANDROID_LOG_FATAL, tag, buf);
207
208    exit(1);
209
210    return -1;
211}
212
213/*
214 * Event logging.
215 */
216
217// must be kept in sync with frameworks/base/core/java/android/util/EventLog.java
218typedef enum {
219    EVENT_TYPE_INT      = 0,
220    EVENT_TYPE_LONG     = 1,
221    EVENT_TYPE_STRING   = 2,
222    EVENT_TYPE_LIST     = 3,
223} AndroidEventLogType;
224
225static int __libc_android_log_btwrite(int32_t tag, char type, const void *payload, size_t len)
226{
227    struct iovec vec[3];
228
229    vec[0].iov_base = &tag;
230    vec[0].iov_len = sizeof(tag);
231    vec[1].iov_base = &type;
232    vec[1].iov_len = sizeof(type);
233    vec[2].iov_base = (void*)payload;
234    vec[2].iov_len = len;
235
236    return log_channels[LOG_ID_EVENTS].logger(LOG_ID_EVENTS, vec);
237}
238
239__LIBC_HIDDEN__
240void __libc_android_log_event_int(int32_t tag, int value)
241{
242    __libc_android_log_btwrite(tag, EVENT_TYPE_INT, &value, sizeof(value));
243}
244
245__LIBC_HIDDEN__
246void __libc_android_log_event_uid(int32_t tag)
247{
248    __libc_android_log_event_int(tag, getuid());
249}
250