logd_write.c revision 7e2f83c0bcc3ad8a2840a48be14d302ed79d671c 
1/*
2 * Copyright (C) 2007-2014 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#include <errno.h>
17#include <fcntl.h>
18#ifdef HAVE_PTHREADS
19#include <pthread.h>
20#endif
21#include <stdarg.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <sys/stat.h>
26#include <sys/types.h>
27#if (FAKE_LOG_DEVICE == 0)
28#include <sys/socket.h>
29#include <sys/un.h>
30#endif
31#include <time.h>
32#include <unistd.h>
33
34#include <log/logd.h>
35#include <log/logger.h>
36#include <log/log_read.h>
37#include <private/android_filesystem_config.h>
38
39#define LOG_BUF_SIZE 1024
40
41#if FAKE_LOG_DEVICE
42/* This will be defined when building for the host. */
43#include "fake_log_device.h"
44#endif
45
46static int __write_to_log_init(log_id_t, struct iovec *vec, size_t nr);
47static int (*write_to_log)(log_id_t, struct iovec *vec, size_t nr) = __write_to_log_init;
48#ifdef HAVE_PTHREADS
49static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
50#endif
51
52#define UNUSED  __attribute__((__unused__))
53
54static int logd_fd = -1;
55#if FAKE_LOG_DEVICE
56#define WEAK __attribute__((weak))
57static int log_fds[(int)LOG_ID_MAX] = { -1, -1, -1, -1 };
58#endif
59
60/*
61 * This is used by the C++ code to decide if it should write logs through
62 * the C code.  Basically, if /dev/socket/logd is available, we're running in
63 * the simulator rather than a desktop tool and want to use the device.
64 */
65static enum {
66    kLogUninitialized, kLogNotAvailable, kLogAvailable
67} g_log_status = kLogUninitialized;
68int __android_log_dev_available(void)
69{
70    if (g_log_status == kLogUninitialized) {
71        if (access("/dev/socket/logdw", W_OK) == 0)
72            g_log_status = kLogAvailable;
73        else
74            g_log_status = kLogNotAvailable;
75    }
76
77    return (g_log_status == kLogAvailable);
78}
79
80static int __write_to_log_null(log_id_t log_fd UNUSED, struct iovec *vec UNUSED,
81                               size_t nr UNUSED)
82{
83    return -1;
84}
85
86static int __write_to_log_kernel(log_id_t log_id, struct iovec *vec, size_t nr)
87{
88#if FAKE_LOG_DEVICE
89    ssize_t ret;
90    int log_fd;
91
92    if (/*(int)log_id >= 0 &&*/ (int)log_id < (int)LOG_ID_MAX) {
93        log_fd = log_fds[(int)log_id];
94    } else {
95        return EBADF;
96    }
97    do {
98        ret = fakeLogWritev(log_fd, vec, nr);
99    } while (ret < 0 && errno == EINTR);
100
101    return ret;
102#else
103    if (logd_fd == -1) {
104        return -1;
105    }
106    if (getuid() == AID_LOGD) {
107        /*
108         * ignore log messages we send to ourself.
109         * Such log messages are often generated by libraries we depend on
110         * which use standard Android logging.
111         */
112        return 0;
113    }
114    struct iovec newVec[nr + 2];
115    typeof_log_id_t log_id_buf = log_id;
116
117    newVec[0].iov_base   = (unsigned char *) &log_id_buf;
118    newVec[0].iov_len    = sizeof_log_id_t;
119
120    struct timespec ts;
121    clock_gettime(CLOCK_REALTIME, &ts);
122    log_time realtime_ts;
123    realtime_ts.tv_sec = ts.tv_sec;
124    realtime_ts.tv_nsec = ts.tv_nsec;
125
126    newVec[1].iov_base   = (unsigned char *) &realtime_ts;
127    newVec[1].iov_len    = sizeof(log_time);
128
129    size_t i;
130    for (i = 2; i < nr + 2; i++) {
131        newVec[i].iov_base = vec[i-2].iov_base;
132        newVec[i].iov_len  = vec[i-2].iov_len;
133    }
134
135    /* The write below could be lost, but will never block. */
136    return writev(logd_fd, newVec, nr + 2);
137#endif
138}
139
140#if FAKE_LOG_DEVICE
141static const char *LOG_NAME[LOG_ID_MAX] = {
142    [LOG_ID_MAIN] = "main",
143    [LOG_ID_RADIO] = "radio",
144    [LOG_ID_EVENTS] = "events",
145    [LOG_ID_SYSTEM] = "system"
146};
147
148const WEAK char *android_log_id_to_name(log_id_t log_id)
149{
150    if (log_id >= LOG_ID_MAX) {
151        log_id = LOG_ID_MAIN;
152    }
153    return LOG_NAME[log_id];
154}
155#endif
156
157static int __write_to_log_init(log_id_t log_id, struct iovec *vec, size_t nr)
158{
159#ifdef HAVE_PTHREADS
160    pthread_mutex_lock(&log_init_lock);
161#endif
162
163    if (write_to_log == __write_to_log_init) {
164        write_to_log = __write_to_log_kernel;
165
166#if FAKE_LOG_DEVICE
167        int i;
168        for (i = 0; i < LOG_ID_MAX; i++) {
169            char buf[sizeof("/dev/log_system")];
170            snprintf(buf, sizeof(buf), "/dev/log_%s", android_log_id_to_name(i));
171            log_fds[i] = fakeLogOpen(buf, O_WRONLY);
172        }
173#else
174        int sock = socket(PF_UNIX, SOCK_DGRAM, 0);
175        if (sock != -1) {
176            if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1) {
177                /* NB: Loss of content */
178                close(sock);
179                sock = -1;
180            } else {
181                struct sockaddr_un un;
182                memset(&un, 0, sizeof(struct sockaddr_un));
183                un.sun_family = AF_UNIX;
184                strcpy(un.sun_path, "/dev/socket/logdw");
185
186                connect(sock, (struct sockaddr *)&un, sizeof(struct sockaddr_un));
187            }
188        } else {
189            write_to_log = __write_to_log_null;
190        }
191        logd_fd = sock;
192#endif
193    }
194
195#ifdef HAVE_PTHREADS
196    pthread_mutex_unlock(&log_init_lock);
197#endif
198
199    return write_to_log(log_id, vec, nr);
200}
201
202int __android_log_write(int prio, const char *tag, const char *msg)
203{
204    struct iovec vec[3];
205    log_id_t log_id = LOG_ID_MAIN;
206    char tmp_tag[32];
207
208    if (!tag)
209        tag = "";
210
211    /* XXX: This needs to go! */
212    if (!strcmp(tag, "HTC_RIL") ||
213        !strncmp(tag, "RIL", 3) || /* Any log tag with "RIL" as the prefix */
214        !strncmp(tag, "IMS", 3) || /* Any log tag with "IMS" as the prefix */
215        !strcmp(tag, "AT") ||
216        !strcmp(tag, "GSM") ||
217        !strcmp(tag, "STK") ||
218        !strcmp(tag, "CDMA") ||
219        !strcmp(tag, "PHONE") ||
220        !strcmp(tag, "SMS")) {
221            log_id = LOG_ID_RADIO;
222            // Inform third party apps/ril/radio.. to use Rlog or RLOG
223            snprintf(tmp_tag, sizeof(tmp_tag), "use-Rlog/RLOG-%s", tag);
224            tag = tmp_tag;
225    }
226
227    vec[0].iov_base   = (unsigned char *) &prio;
228    vec[0].iov_len    = 1;
229    vec[1].iov_base   = (void *) tag;
230    vec[1].iov_len    = strlen(tag) + 1;
231    vec[2].iov_base   = (void *) msg;
232    vec[2].iov_len    = strlen(msg) + 1;
233
234    return write_to_log(log_id, vec, 3);
235}
236
237int __android_log_buf_write(int bufID, int prio, const char *tag, const char *msg)
238{
239    struct iovec vec[3];
240    char tmp_tag[32];
241
242    if (!tag)
243        tag = "";
244
245    /* XXX: This needs to go! */
246    if ((bufID != LOG_ID_RADIO) &&
247         (!strcmp(tag, "HTC_RIL") ||
248        !strncmp(tag, "RIL", 3) || /* Any log tag with "RIL" as the prefix */
249        !strncmp(tag, "IMS", 3) || /* Any log tag with "IMS" as the prefix */
250        !strcmp(tag, "AT") ||
251        !strcmp(tag, "GSM") ||
252        !strcmp(tag, "STK") ||
253        !strcmp(tag, "CDMA") ||
254        !strcmp(tag, "PHONE") ||
255        !strcmp(tag, "SMS"))) {
256            bufID = LOG_ID_RADIO;
257            // Inform third party apps/ril/radio.. to use Rlog or RLOG
258            snprintf(tmp_tag, sizeof(tmp_tag), "use-Rlog/RLOG-%s", tag);
259            tag = tmp_tag;
260    }
261
262    vec[0].iov_base   = (unsigned char *) &prio;
263    vec[0].iov_len    = 1;
264    vec[1].iov_base   = (void *) tag;
265    vec[1].iov_len    = strlen(tag) + 1;
266    vec[2].iov_base   = (void *) msg;
267    vec[2].iov_len    = strlen(msg) + 1;
268
269    return write_to_log(bufID, vec, 3);
270}
271
272int __android_log_vprint(int prio, const char *tag, const char *fmt, va_list ap)
273{
274    char buf[LOG_BUF_SIZE];
275
276    vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
277
278    return __android_log_write(prio, tag, buf);
279}
280
281int __android_log_print(int prio, const char *tag, const char *fmt, ...)
282{
283    va_list ap;
284    char buf[LOG_BUF_SIZE];
285
286    va_start(ap, fmt);
287    vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
288    va_end(ap);
289
290    return __android_log_write(prio, tag, buf);
291}
292
293int __android_log_buf_print(int bufID, int prio, const char *tag, const char *fmt, ...)
294{
295    va_list ap;
296    char buf[LOG_BUF_SIZE];
297
298    va_start(ap, fmt);
299    vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
300    va_end(ap);
301
302    return __android_log_buf_write(bufID, prio, tag, buf);
303}
304
305void __android_log_assert(const char *cond, const char *tag,
306                          const char *fmt, ...)
307{
308    char buf[LOG_BUF_SIZE];
309
310    if (fmt) {
311        va_list ap;
312        va_start(ap, fmt);
313        vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
314        va_end(ap);
315    } else {
316        /* Msg not provided, log condition.  N.B. Do not use cond directly as
317         * format string as it could contain spurious '%' syntax (e.g.
318         * "%d" in "blocks%devs == 0").
319         */
320        if (cond)
321            snprintf(buf, LOG_BUF_SIZE, "Assertion failed: %s", cond);
322        else
323            strcpy(buf, "Unspecified assertion failed");
324    }
325
326    __android_log_write(ANDROID_LOG_FATAL, tag, buf);
327
328    __builtin_trap(); /* trap so we have a chance to debug the situation */
329}
330
331int __android_log_bwrite(int32_t tag, const void *payload, size_t len)
332{
333    struct iovec vec[2];
334
335    vec[0].iov_base = &tag;
336    vec[0].iov_len = sizeof(tag);
337    vec[1].iov_base = (void*)payload;
338    vec[1].iov_len = len;
339
340    return write_to_log(LOG_ID_EVENTS, vec, 2);
341}
342
343/*
344 * Like __android_log_bwrite, but takes the type as well.  Doesn't work
345 * for the general case where we're generating lists of stuff, but very
346 * handy if we just want to dump an integer into the log.
347 */
348int __android_log_btwrite(int32_t tag, char type, const void *payload,
349                          size_t len)
350{
351    struct iovec vec[3];
352
353    vec[0].iov_base = &tag;
354    vec[0].iov_len = sizeof(tag);
355    vec[1].iov_base = &type;
356    vec[1].iov_len = sizeof(type);
357    vec[2].iov_base = (void*)payload;
358    vec[2].iov_len = len;
359
360    return write_to_log(LOG_ID_EVENTS, vec, 3);
361}
362