summaryrefslogtreecommitdiffstats
blob: 8a8ece250231e05aefa09ba53dacbc2089488db9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
/*
 * Copyright (C) 2008-2014 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.
 */
/*
 * Intercepts log messages intended for the Android log device.
 * When running in the context of the simulator, the messages are
 * passed on to the underlying (fake) log device.  When not in the
 * simulator, messages are printed to stderr.
 */
#include "fake_log_device.h"

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>

#include <log/logd.h>

#if !defined(_WIN32)
#include <pthread.h>
#endif

#ifndef __unused
#define __unused __attribute__((__unused__))
#endif

#define kMaxTagLen  16      /* from the long-dead utils/Log.cpp */

#define kTagSetSize 16      /* arbitrary */

#if 0
#define TRACE(...) printf("fake_log_device: " __VA_ARGS__)
#else
#define TRACE(...) ((void)0)
#endif

/* from the long-dead utils/Log.cpp */
typedef enum {
    FORMAT_OFF = 0,
    FORMAT_BRIEF,
    FORMAT_PROCESS,
    FORMAT_TAG,
    FORMAT_THREAD,
    FORMAT_RAW,
    FORMAT_TIME,
    FORMAT_THREADTIME,
    FORMAT_LONG
} LogFormat;


/*
 * Log driver state.
 */
typedef struct LogState {
    /* the fake fd that's seen by the user */
    int     fakeFd;

    /* a printable name for this fake device */
    char   *debugName;

    /* nonzero if this is a binary log */
    int     isBinary;

    /* global minimum priority */
    int     globalMinPriority;

    /* output format */
    LogFormat outputFormat;

    /* tags and priorities */
    struct {
        char    tag[kMaxTagLen];
        int     minPriority;
    } tagSet[kTagSetSize];
} LogState;


#if !defined(_WIN32)
/*
 * Locking.  Since we're emulating a device, we need to be prepared
 * to have multiple callers at the same time.  This lock is used
 * to both protect the fd list and to prevent LogStates from being
 * freed out from under a user.
 */
static pthread_mutex_t fakeLogDeviceLock = PTHREAD_MUTEX_INITIALIZER;

static void lock()
{
    pthread_mutex_lock(&fakeLogDeviceLock);
}

static void unlock()
{
    pthread_mutex_unlock(&fakeLogDeviceLock);
}
#else   // !defined(_WIN32)
#define lock() ((void)0)
#define unlock() ((void)0)
#endif  // !defined(_WIN32)


/*
 * File descriptor management.
 */
#define FAKE_FD_BASE 10000
#define MAX_OPEN_LOGS 16
static LogState *openLogTable[MAX_OPEN_LOGS];

/*
 * Allocate an fd and associate a new LogState with it.
 * The fd is available via the fakeFd field of the return value.
 */
static LogState *createLogState()
{
    size_t i;

    for (i = 0; i < sizeof(openLogTable); i++) {
        if (openLogTable[i] == NULL) {
            openLogTable[i] = calloc(1, sizeof(LogState));
            openLogTable[i]->fakeFd = FAKE_FD_BASE + i;
            return openLogTable[i];
        }
    }
    return NULL;
}

/*
 * Translate an fd to a LogState.
 */
static LogState *fdToLogState(int fd)
{
    if (fd >= FAKE_FD_BASE && fd < FAKE_FD_BASE + MAX_OPEN_LOGS) {
        return openLogTable[fd - FAKE_FD_BASE];
    }
    return NULL;
}

/*
 * Unregister the fake fd and free the memory it pointed to.
 */
static void deleteFakeFd(int fd)
{
    LogState *ls;

    lock();

    ls = fdToLogState(fd);
    if (ls != NULL) {
        openLogTable[fd - FAKE_FD_BASE] = NULL;
        free(ls->debugName);
        free(ls);
    }

    unlock();
}

/*
 * Configure logging based on ANDROID_LOG_TAGS environment variable.  We
 * need to parse a string that looks like
 *
 *   *:v jdwp:d dalvikvm:d dalvikvm-gc:i dalvikvmi:i
 *
 * The tag (or '*' for the global level) comes first, followed by a colon
 * and a letter indicating the minimum priority level we're expected to log.
 * This can be used to reveal or conceal logs with specific tags.
 *
 * We also want to check ANDROID_PRINTF_LOG to determine how the output
 * will look.
 */
static void configureInitialState(const char* pathName, LogState* logState)
{
    static const int kDevLogLen = sizeof("/dev/log/") - 1;

    logState->debugName = strdup(pathName);

    /* identify binary logs */
    if (strcmp(pathName + kDevLogLen, "events") == 0) {
        logState->isBinary = 1;
    }

    /* global min priority defaults to "info" level */
    logState->globalMinPriority = ANDROID_LOG_INFO;

    /*
     * This is based on the the long-dead utils/Log.cpp code.
     */
    const char* tags = getenv("ANDROID_LOG_TAGS");
    TRACE("Found ANDROID_LOG_TAGS='%s'\n", tags);
    if (tags != NULL) {
        int entry = 0;

        while (*tags != '\0') {
            char tagName[kMaxTagLen];
            int i, minPrio;

            while (isspace(*tags))
                tags++;

            i = 0;
            while (*tags != '\0' && !isspace(*tags) && *tags != ':' &&
                i < kMaxTagLen)
            {
                tagName[i++] = *tags++;
            }
            if (i == kMaxTagLen) {
                TRACE("ERROR: env tag too long (%d chars max)\n", kMaxTagLen-1);
                return;
            }
            tagName[i] = '\0';

            /* default priority, if there's no ":" part; also zero out '*' */
            minPrio = ANDROID_LOG_VERBOSE;
            if (tagName[0] == '*' && tagName[1] == '\0') {
                minPrio = ANDROID_LOG_DEBUG;
                tagName[0] = '\0';
            }

            if (*tags == ':') {
                tags++;
                if (*tags >= '0' && *tags <= '9') {
                    if (*tags >= ('0' + ANDROID_LOG_SILENT))
                        minPrio = ANDROID_LOG_VERBOSE;
                    else
                        minPrio = *tags - '\0';
                } else {
                    switch (*tags) {
                    case 'v':   minPrio = ANDROID_LOG_VERBOSE;  break;
                    case 'd':   minPrio = ANDROID_LOG_DEBUG;    break;
                    case 'i':   minPrio = ANDROID_LOG_INFO;     break;
                    case 'w':   minPrio = ANDROID_LOG_WARN;     break;
                    case 'e':   minPrio = ANDROID_LOG_ERROR;    break;
                    case 'f':   minPrio = ANDROID_LOG_FATAL;    break;
                    case 's':   minPrio = ANDROID_LOG_SILENT;   break;
                    default:    minPrio = ANDROID_LOG_DEFAULT;  break;
                    }
                }

                tags++;
                if (*tags != '\0' && !isspace(*tags)) {
                    TRACE("ERROR: garbage in tag env; expected whitespace\n");
                    TRACE("       env='%s'\n", tags);
                    return;
                }
            }

            if (tagName[0] == 0) {
                logState->globalMinPriority = minPrio;
                TRACE("+++ global min prio %d\n", logState->globalMinPriority);
            } else {
                logState->tagSet[entry].minPriority = minPrio;
                strcpy(logState->tagSet[entry].tag, tagName);
                TRACE("+++ entry %d: %s:%d\n",
                    entry,
                    logState->tagSet[entry].tag,
                    logState->tagSet[entry].minPriority);
                entry++;
            }
        }
    }


    /*
     * Taken from the long-dead utils/Log.cpp
     */
    const char* fstr = getenv("ANDROID_PRINTF_LOG");
    LogFormat format;
    if (fstr == NULL) {
        format = FORMAT_BRIEF;
    } else {
        if (strcmp(fstr, "brief") == 0)
            format = FORMAT_BRIEF;
        else if (strcmp(fstr, "process") == 0)
            format = FORMAT_PROCESS;
        else if (strcmp(fstr, "tag") == 0)
            format = FORMAT_PROCESS;
        else if (strcmp(fstr, "thread") == 0)
            format = FORMAT_PROCESS;
        else if (strcmp(fstr, "raw") == 0)
            format = FORMAT_PROCESS;
        else if (strcmp(fstr, "time") == 0)
            format = FORMAT_PROCESS;
        else if (strcmp(fstr, "long") == 0)
            format = FORMAT_PROCESS;
        else
            format = (LogFormat) atoi(fstr);        // really?!
    }

    logState->outputFormat = format;
}

/*
 * Return a human-readable string for the priority level.  Always returns
 * a valid string.
 */
static const char* getPriorityString(int priority)
{
    /* the first character of each string should be unique */
    static const char* priorityStrings[] = {
        "Verbose", "Debug", "Info", "Warn", "Error", "Assert"
    };
    int idx;

    idx = (int) priority - (int) ANDROID_LOG_VERBOSE;
    if (idx < 0 ||
        idx >= (int) (sizeof(priorityStrings) / sizeof(priorityStrings[0])))
        return "?unknown?";
    return priorityStrings[idx];
}

#if defined(_WIN32)
/*
 * WIN32 does not have writev().
 * Make up something to replace it.
 */
static ssize_t fake_writev(int fd, const struct iovec *iov, int iovcnt) {
    ssize_t result = 0;
    const struct iovec* end = iov + iovcnt;
    for (; iov < end; iov++) {
        ssize_t w = write(fd, iov->iov_base, iov->iov_len);
        if (w != (ssize_t) iov->iov_len) {
            if (w < 0)
                return w;
            return result + w;
        }
        result += w;
    }
    return result;
}

#define writev fake_writev
#endif


/*
 * Write a filtered log message to stderr.
 *
 * Log format parsing taken from the long-dead utils/Log.cpp.
 */
static void showLog(LogState *state,
        int logPrio, const char* tag, const char* msg)
{
#if !defined(_WIN32)
    struct tm tmBuf;
#endif
    struct tm* ptm;
    char timeBuf[32];
    char prefixBuf[128], suffixBuf[128];
    char priChar;
    time_t when;
    pid_t pid, tid;

    TRACE("LOG %d: %s %s", logPrio, tag, msg);

    priChar = getPriorityString(logPrio)[0];
    when = time(NULL);
    pid = tid = getpid();       // find gettid()?

    /*
     * Get the current date/time in pretty form
     *
     * It's often useful when examining a log with "less" to jump to
     * a specific point in the file by searching for the date/time stamp.
     * For this reason it's very annoying to have regexp meta characters
     * in the time stamp.  Don't use forward slashes, parenthesis,
     * brackets, asterisks, or other special chars here.
     */
#if !defined(_WIN32)
    ptm = localtime_r(&when, &tmBuf);
#else
    ptm = localtime(&when);
#endif
    //strftime(timeBuf, sizeof(timeBuf), "%Y-%m-%d %H:%M:%S", ptm);
    strftime(timeBuf, sizeof(timeBuf), "%m-%d %H:%M:%S", ptm);

    /*
     * Construct a buffer containing the log header and log message.
     */
    size_t prefixLen, suffixLen;

    switch (state->outputFormat) {
    case FORMAT_TAG:
        prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
            "%c/%-8s: ", priChar, tag);
        strcpy(suffixBuf, "\n"); suffixLen = 1;
        break;
    case FORMAT_PROCESS:
        prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
            "%c(%5d) ", priChar, pid);
        suffixLen = snprintf(suffixBuf, sizeof(suffixBuf),
            "  (%s)\n", tag);
        break;
    case FORMAT_THREAD:
        prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
            "%c(%5d:%5d) ", priChar, pid, tid);
        strcpy(suffixBuf, "\n"); suffixLen = 1;
        break;
    case FORMAT_RAW:
        prefixBuf[0] = 0; prefixLen = 0;
        strcpy(suffixBuf, "\n"); suffixLen = 1;
        break;
    case FORMAT_TIME:
        prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
            "%s %-8s\n\t", timeBuf, tag);
        strcpy(suffixBuf, "\n"); suffixLen = 1;
        break;
    case FORMAT_THREADTIME:
        prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
            "%s %5d %5d %c %-8s \n\t", timeBuf, pid, tid, priChar, tag);
        strcpy(suffixBuf, "\n"); suffixLen = 1;
        break;
    case FORMAT_LONG:
        prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
            "[ %s %5d:%5d %c/%-8s ]\n",
            timeBuf, pid, tid, priChar, tag);
        strcpy(suffixBuf, "\n\n"); suffixLen = 2;
        break;
    default:
        prefixLen = snprintf(prefixBuf, sizeof(prefixBuf),
            "%c/%-8s(%5d): ", priChar, tag, pid);
        strcpy(suffixBuf, "\n"); suffixLen = 1;
        break;
     }

    /*
     * Figure out how many lines there will be.
     */
    const char* end = msg + strlen(msg);
    size_t numLines = 0;
    const char* p = msg;
    while (p < end) {
        if (*p++ == '\n') numLines++;
    }
    if (p > msg && *(p-1) != '\n') numLines++;

    /*
     * Create an array of iovecs large enough to write all of
     * the lines with a prefix and a suffix.
     */
    const size_t INLINE_VECS = 6;
    const size_t MAX_LINES   = ((size_t)~0)/(3*sizeof(struct iovec*));
    struct iovec stackVec[INLINE_VECS];
    struct iovec* vec = stackVec;
    size_t numVecs;

    if (numLines > MAX_LINES)
        numLines = MAX_LINES;

    numVecs = numLines*3;  // 3 iovecs per line.
    if (numVecs > INLINE_VECS) {
        vec = (struct iovec*)malloc(sizeof(struct iovec)*numVecs);
        if (vec == NULL) {
            msg = "LOG: write failed, no memory";
            numVecs = 3;
            numLines = 1;
            vec = stackVec;
        }
    }

    /*
     * Fill in the iovec pointers.
     */
    p = msg;
    struct iovec* v = vec;
    int totalLen = 0;
    while (numLines > 0 && p < end) {
        if (prefixLen > 0) {
            v->iov_base = prefixBuf;
            v->iov_len = prefixLen;
            totalLen += prefixLen;
            v++;
        }
        const char* start = p;
        while (p < end && *p != '\n') p++;
        if ((p-start) > 0) {
            v->iov_base = (void*)start;
            v->iov_len = p-start;
            totalLen += p-start;
            v++;
        }
        if (*p == '\n') p++;
        if (suffixLen > 0) {
            v->iov_base = suffixBuf;
            v->iov_len = suffixLen;
            totalLen += suffixLen;
            v++;
        }
        numLines -= 1;
    }
    
    /*
     * Write the entire message to the log file with a single writev() call.
     * We need to use this rather than a collection of printf()s on a FILE*
     * because of multi-threading and multi-process issues.
     *
     * If the file was not opened with O_APPEND, this will produce interleaved
     * output when called on the same file from multiple processes.
     *
     * If the file descriptor is actually a network socket, the writev()
     * call may return with a partial write.  Putting the writev() call in
     * a loop can result in interleaved data.  This can be alleviated
     * somewhat by wrapping the writev call in the Mutex.
     */

    for(;;) {
        int cc = writev(fileno(stderr), vec, v-vec);

        if (cc == totalLen) break;
        
        if (cc < 0) {
            if(errno == EINTR) continue;
            
                /* can't really log the failure; for now, throw out a stderr */
            fprintf(stderr, "+++ LOG: write failed (errno=%d)\n", errno);
            break;
        } else {
                /* shouldn't happen when writing to file or tty */
            fprintf(stderr, "+++ LOG: write partial (%d of %d)\n", cc, totalLen);
            break;
        }
    }

    /* if we allocated storage for the iovecs, free it */
    if (vec != stackVec)
        free(vec);
}


/*
 * Receive a log message.  We happen to know that "vector" has three parts:
 *
 *  priority (1 byte)
 *  tag (N bytes -- null-terminated ASCII string)
 *  message (N bytes -- null-terminated ASCII string)
 */
static ssize_t logWritev(int fd, const struct iovec* vector, int count)
{
    LogState* state;

    /* Make sure that no-one frees the LogState while we're using it.
     * Also guarantees that only one thread is in showLog() at a given
     * time (if it matters).
     */
    lock();

    state = fdToLogState(fd);
    if (state == NULL) {
        errno = EBADF;
        goto error;
    }

    if (state->isBinary) {
        TRACE("%s: ignoring binary log\n", state->debugName);
        goto bail;
    }

    if (count != 3) {
        TRACE("%s: writevLog with count=%d not expected\n",
            state->debugName, count);
        goto error;
    }

    /* pull out the three fields */
    int logPrio = *(const char*)vector[0].iov_base;
    const char* tag = (const char*) vector[1].iov_base;
    const char* msg = (const char*) vector[2].iov_base;

    /* see if this log tag is configured */
    int i;
    int minPrio = state->globalMinPriority;
    for (i = 0; i < kTagSetSize; i++) {
        if (state->tagSet[i].minPriority == ANDROID_LOG_UNKNOWN)
            break;      /* reached end of configured values */

        if (strcmp(state->tagSet[i].tag, tag) == 0) {
            //TRACE("MATCH tag '%s'\n", tag);
            minPrio = state->tagSet[i].minPriority;
            break;
        }
    }

    if (logPrio >= minPrio) {
        showLog(state, logPrio, tag, msg);
    } else {
        //TRACE("+++ NOLOG(%d): %s %s", logPrio, tag, msg);
    }

bail:
    unlock();
    return vector[0].iov_len + vector[1].iov_len + vector[2].iov_len;
error:
    unlock();
    return -1;
}

/*
 * Free up our state and close the fake descriptor.
 */
static int logClose(int fd)
{
    deleteFakeFd(fd);
    return 0;
}

/*
 * Open a log output device and return a fake fd.
 */
static int logOpen(const char* pathName, int flags __unused)
{
    LogState *logState;
    int fd = -1;

    lock();

    logState = createLogState();
    if (logState != NULL) {
        configureInitialState(pathName, logState);
        fd = logState->fakeFd;
    } else  {
        errno = ENFILE;
    }

    unlock();

    return fd;
}


/*
 * Runtime redirection.  If this binary is running in the simulator,
 * just pass log messages to the emulated device.  If it's running
 * outside of the simulator, write the log messages to stderr.
 */

static int (*redirectOpen)(const char *pathName, int flags) = NULL;
static int (*redirectClose)(int fd) = NULL;
static ssize_t (*redirectWritev)(int fd, const struct iovec* vector, int count)
        = NULL;

static void setRedirects()
{
    const char *ws;

    /* Wrapsim sets this environment variable on children that it's
     * created using its LD_PRELOAD wrapper.
     */
    ws = getenv("ANDROID_WRAPSIM");
    if (ws != NULL && strcmp(ws, "1") == 0) {
        /* We're running inside wrapsim, so we can just write to the device. */
        redirectOpen = (int (*)(const char *pathName, int flags))open;
        redirectClose = close;
        redirectWritev = writev;
    } else {
        /* There's no device to delegate to; handle the logging ourselves. */
        redirectOpen = logOpen;
        redirectClose = logClose;
        redirectWritev = logWritev;
    }
}

int fakeLogOpen(const char *pathName, int flags)
{
    if (redirectOpen == NULL) {
        setRedirects();
    }
    return redirectOpen(pathName, flags);
}

int fakeLogClose(int fd)
{
    /* Assume that open() was called first. */
    return redirectClose(fd);
}

ssize_t fakeLogWritev(int fd, const struct iovec* vector, int count)
{
    /* Assume that open() was called first. */
    return redirectWritev(fd, vector, count);
}

int __android_log_is_loggable(int prio, const char *tag __unused, int def)
{
    int logLevel = def;
    return logLevel >= 0 && prio >= logLevel;
}