Parcel.cpp revision ce9f107c9d9ad4fdc0ad43ccd545823caa3cf933 
1/*
2 * Copyright (C) 2005 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#define LOG_TAG "Parcel"
18//#define LOG_NDEBUG 0
19
20#include <binder/Parcel.h>
21
22#include <binder/IPCThreadState.h>
23#include <binder/Binder.h>
24#include <binder/BpBinder.h>
25#include <binder/ProcessState.h>
26#include <binder/TextOutput.h>
27
28#include <utils/Debug.h>
29#include <utils/Log.h>
30#include <utils/String8.h>
31#include <utils/String16.h>
32#include <utils/misc.h>
33#include <utils/Flattenable.h>
34#include <cutils/ashmem.h>
35
36#include <private/binder/binder_module.h>
37
38#include <inttypes.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <stdint.h>
42#include <sys/mman.h>
43
44#ifndef INT32_MAX
45#define INT32_MAX ((int32_t)(2147483647))
46#endif
47
48#define LOG_REFS(...)
49//#define LOG_REFS(...) ALOG(LOG_DEBUG, "Parcel", __VA_ARGS__)
50
51// ---------------------------------------------------------------------------
52
53#define PAD_SIZE(s) (((s)+3)&~3)
54
55// Note: must be kept in sync with android/os/StrictMode.java's PENALTY_GATHER
56#define STRICT_MODE_PENALTY_GATHER 0x100
57
58// Note: must be kept in sync with android/os/Parcel.java's EX_HAS_REPLY_HEADER
59#define EX_HAS_REPLY_HEADER -128
60
61// Maximum size of a blob to transfer in-place.
62static const size_t IN_PLACE_BLOB_LIMIT = 40 * 1024;
63
64// XXX This can be made public if we want to provide
65// support for typed data.
66struct small_flat_data
67{
68    uint32_t type;
69    uint32_t data;
70};
71
72namespace android {
73
74void acquire_object(const sp<ProcessState>& proc,
75    const flat_binder_object& obj, const void* who)
76{
77    switch (obj.type) {
78        case BINDER_TYPE_BINDER:
79            if (obj.binder) {
80                LOG_REFS("Parcel %p acquiring reference on local %p", who, obj.cookie);
81                reinterpret_cast<IBinder*>(obj.cookie)->incStrong(who);
82            }
83            return;
84        case BINDER_TYPE_WEAK_BINDER:
85            if (obj.binder)
86                reinterpret_cast<RefBase::weakref_type*>(obj.binder)->incWeak(who);
87            return;
88        case BINDER_TYPE_HANDLE: {
89            const sp<IBinder> b = proc->getStrongProxyForHandle(obj.handle);
90            if (b != NULL) {
91                LOG_REFS("Parcel %p acquiring reference on remote %p", who, b.get());
92                b->incStrong(who);
93            }
94            return;
95        }
96        case BINDER_TYPE_WEAK_HANDLE: {
97            const wp<IBinder> b = proc->getWeakProxyForHandle(obj.handle);
98            if (b != NULL) b.get_refs()->incWeak(who);
99            return;
100        }
101        case BINDER_TYPE_FD: {
102            // intentionally blank -- nothing to do to acquire this, but we do
103            // recognize it as a legitimate object type.
104            return;
105        }
106    }
107
108    ALOGD("Invalid object type 0x%08x", obj.type);
109}
110
111void release_object(const sp<ProcessState>& proc,
112    const flat_binder_object& obj, const void* who)
113{
114    switch (obj.type) {
115        case BINDER_TYPE_BINDER:
116            if (obj.binder) {
117                LOG_REFS("Parcel %p releasing reference on local %p", who, obj.cookie);
118                reinterpret_cast<IBinder*>(obj.cookie)->decStrong(who);
119            }
120            return;
121        case BINDER_TYPE_WEAK_BINDER:
122            if (obj.binder)
123                reinterpret_cast<RefBase::weakref_type*>(obj.binder)->decWeak(who);
124            return;
125        case BINDER_TYPE_HANDLE: {
126            const sp<IBinder> b = proc->getStrongProxyForHandle(obj.handle);
127            if (b != NULL) {
128                LOG_REFS("Parcel %p releasing reference on remote %p", who, b.get());
129                b->decStrong(who);
130            }
131            return;
132        }
133        case BINDER_TYPE_WEAK_HANDLE: {
134            const wp<IBinder> b = proc->getWeakProxyForHandle(obj.handle);
135            if (b != NULL) b.get_refs()->decWeak(who);
136            return;
137        }
138        case BINDER_TYPE_FD: {
139            if (obj.cookie != 0) close(obj.handle);
140            return;
141        }
142    }
143
144    ALOGE("Invalid object type 0x%08x", obj.type);
145}
146
147inline static status_t finish_flatten_binder(
148    const sp<IBinder>& /*binder*/, const flat_binder_object& flat, Parcel* out)
149{
150    return out->writeObject(flat, false);
151}
152
153status_t flatten_binder(const sp<ProcessState>& /*proc*/,
154    const sp<IBinder>& binder, Parcel* out)
155{
156    flat_binder_object obj;
157
158    obj.flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
159    if (binder != NULL) {
160        IBinder *local = binder->localBinder();
161        if (!local) {
162            BpBinder *proxy = binder->remoteBinder();
163            if (proxy == NULL) {
164                ALOGE("null proxy");
165            }
166            const int32_t handle = proxy ? proxy->handle() : 0;
167            obj.type = BINDER_TYPE_HANDLE;
168            obj.binder = 0; /* Don't pass uninitialized stack data to a remote process */
169            obj.handle = handle;
170            obj.cookie = 0;
171        } else {
172            obj.type = BINDER_TYPE_BINDER;
173            obj.binder = reinterpret_cast<uintptr_t>(local->getWeakRefs());
174            obj.cookie = reinterpret_cast<uintptr_t>(local);
175        }
176    } else {
177        obj.type = BINDER_TYPE_BINDER;
178        obj.binder = 0;
179        obj.cookie = 0;
180    }
181
182    return finish_flatten_binder(binder, obj, out);
183}
184
185status_t flatten_binder(const sp<ProcessState>& /*proc*/,
186    const wp<IBinder>& binder, Parcel* out)
187{
188    flat_binder_object obj;
189
190    obj.flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
191    if (binder != NULL) {
192        sp<IBinder> real = binder.promote();
193        if (real != NULL) {
194            IBinder *local = real->localBinder();
195            if (!local) {
196                BpBinder *proxy = real->remoteBinder();
197                if (proxy == NULL) {
198                    ALOGE("null proxy");
199                }
200                const int32_t handle = proxy ? proxy->handle() : 0;
201                obj.type = BINDER_TYPE_WEAK_HANDLE;
202                obj.binder = 0; /* Don't pass uninitialized stack data to a remote process */
203                obj.handle = handle;
204                obj.cookie = 0;
205            } else {
206                obj.type = BINDER_TYPE_WEAK_BINDER;
207                obj.binder = reinterpret_cast<uintptr_t>(binder.get_refs());
208                obj.cookie = reinterpret_cast<uintptr_t>(binder.unsafe_get());
209            }
210            return finish_flatten_binder(real, obj, out);
211        }
212
213        // XXX How to deal?  In order to flatten the given binder,
214        // we need to probe it for information, which requires a primary
215        // reference...  but we don't have one.
216        //
217        // The OpenBinder implementation uses a dynamic_cast<> here,
218        // but we can't do that with the different reference counting
219        // implementation we are using.
220        ALOGE("Unable to unflatten Binder weak reference!");
221        obj.type = BINDER_TYPE_BINDER;
222        obj.binder = 0;
223        obj.cookie = 0;
224        return finish_flatten_binder(NULL, obj, out);
225
226    } else {
227        obj.type = BINDER_TYPE_BINDER;
228        obj.binder = 0;
229        obj.cookie = 0;
230        return finish_flatten_binder(NULL, obj, out);
231    }
232}
233
234inline static status_t finish_unflatten_binder(
235    BpBinder* /*proxy*/, const flat_binder_object& /*flat*/,
236    const Parcel& /*in*/)
237{
238    return NO_ERROR;
239}
240
241status_t unflatten_binder(const sp<ProcessState>& proc,
242    const Parcel& in, sp<IBinder>* out)
243{
244    const flat_binder_object* flat = in.readObject(false);
245
246    if (flat) {
247        switch (flat->type) {
248            case BINDER_TYPE_BINDER:
249                *out = reinterpret_cast<IBinder*>(flat->cookie);
250                return finish_unflatten_binder(NULL, *flat, in);
251            case BINDER_TYPE_HANDLE:
252                *out = proc->getStrongProxyForHandle(flat->handle);
253                return finish_unflatten_binder(
254                    static_cast<BpBinder*>(out->get()), *flat, in);
255        }
256    }
257    return BAD_TYPE;
258}
259
260status_t unflatten_binder(const sp<ProcessState>& proc,
261    const Parcel& in, wp<IBinder>* out)
262{
263    const flat_binder_object* flat = in.readObject(false);
264
265    if (flat) {
266        switch (flat->type) {
267            case BINDER_TYPE_BINDER:
268                *out = reinterpret_cast<IBinder*>(flat->cookie);
269                return finish_unflatten_binder(NULL, *flat, in);
270            case BINDER_TYPE_WEAK_BINDER:
271                if (flat->binder != 0) {
272                    out->set_object_and_refs(
273                        reinterpret_cast<IBinder*>(flat->cookie),
274                        reinterpret_cast<RefBase::weakref_type*>(flat->binder));
275                } else {
276                    *out = NULL;
277                }
278                return finish_unflatten_binder(NULL, *flat, in);
279            case BINDER_TYPE_HANDLE:
280            case BINDER_TYPE_WEAK_HANDLE:
281                *out = proc->getWeakProxyForHandle(flat->handle);
282                return finish_unflatten_binder(
283                    static_cast<BpBinder*>(out->unsafe_get()), *flat, in);
284        }
285    }
286    return BAD_TYPE;
287}
288
289// ---------------------------------------------------------------------------
290
291Parcel::Parcel()
292{
293    initState();
294}
295
296Parcel::~Parcel()
297{
298    freeDataNoInit();
299}
300
301const uint8_t* Parcel::data() const
302{
303    return mData;
304}
305
306size_t Parcel::dataSize() const
307{
308    return (mDataSize > mDataPos ? mDataSize : mDataPos);
309}
310
311size_t Parcel::dataAvail() const
312{
313    // TODO: decide what to do about the possibility that this can
314    // report an available-data size that exceeds a Java int's max
315    // positive value, causing havoc.  Fortunately this will only
316    // happen if someone constructs a Parcel containing more than two
317    // gigabytes of data, which on typical phone hardware is simply
318    // not possible.
319    return dataSize() - dataPosition();
320}
321
322size_t Parcel::dataPosition() const
323{
324    return mDataPos;
325}
326
327size_t Parcel::dataCapacity() const
328{
329    return mDataCapacity;
330}
331
332status_t Parcel::setDataSize(size_t size)
333{
334    status_t err;
335    err = continueWrite(size);
336    if (err == NO_ERROR) {
337        mDataSize = size;
338        ALOGV("setDataSize Setting data size of %p to %d\n", this, mDataSize);
339    }
340    return err;
341}
342
343void Parcel::setDataPosition(size_t pos) const
344{
345    mDataPos = pos;
346    mNextObjectHint = 0;
347}
348
349status_t Parcel::setDataCapacity(size_t size)
350{
351    if (size > mDataCapacity) return continueWrite(size);
352    return NO_ERROR;
353}
354
355status_t Parcel::setData(const uint8_t* buffer, size_t len)
356{
357    status_t err = restartWrite(len);
358    if (err == NO_ERROR) {
359        memcpy(const_cast<uint8_t*>(data()), buffer, len);
360        mDataSize = len;
361        mFdsKnown = false;
362    }
363    return err;
364}
365
366status_t Parcel::appendFrom(const Parcel *parcel, size_t offset, size_t len)
367{
368    const sp<ProcessState> proc(ProcessState::self());
369    status_t err;
370    const uint8_t *data = parcel->mData;
371    const binder_size_t *objects = parcel->mObjects;
372    size_t size = parcel->mObjectsSize;
373    int startPos = mDataPos;
374    int firstIndex = -1, lastIndex = -2;
375
376    if (len == 0) {
377        return NO_ERROR;
378    }
379
380    // range checks against the source parcel size
381    if ((offset > parcel->mDataSize)
382            || (len > parcel->mDataSize)
383            || (offset + len > parcel->mDataSize)) {
384        return BAD_VALUE;
385    }
386
387    // Count objects in range
388    for (int i = 0; i < (int) size; i++) {
389        size_t off = objects[i];
390        if ((off >= offset) && (off < offset + len)) {
391            if (firstIndex == -1) {
392                firstIndex = i;
393            }
394            lastIndex = i;
395        }
396    }
397    int numObjects = lastIndex - firstIndex + 1;
398
399    if ((mDataSize+len) > mDataCapacity) {
400        // grow data
401        err = growData(len);
402        if (err != NO_ERROR) {
403            return err;
404        }
405    }
406
407    // append data
408    memcpy(mData + mDataPos, data + offset, len);
409    mDataPos += len;
410    mDataSize += len;
411
412    err = NO_ERROR;
413
414    if (numObjects > 0) {
415        // grow objects
416        if (mObjectsCapacity < mObjectsSize + numObjects) {
417            int newSize = ((mObjectsSize + numObjects)*3)/2;
418            binder_size_t *objects =
419                (binder_size_t*)realloc(mObjects, newSize*sizeof(binder_size_t));
420            if (objects == (binder_size_t*)0) {
421                return NO_MEMORY;
422            }
423            mObjects = objects;
424            mObjectsCapacity = newSize;
425        }
426
427        // append and acquire objects
428        int idx = mObjectsSize;
429        for (int i = firstIndex; i <= lastIndex; i++) {
430            size_t off = objects[i] - offset + startPos;
431            mObjects[idx++] = off;
432            mObjectsSize++;
433
434            flat_binder_object* flat
435                = reinterpret_cast<flat_binder_object*>(mData + off);
436            acquire_object(proc, *flat, this);
437
438            if (flat->type == BINDER_TYPE_FD) {
439                // If this is a file descriptor, we need to dup it so the
440                // new Parcel now owns its own fd, and can declare that we
441                // officially know we have fds.
442                flat->handle = dup(flat->handle);
443                flat->cookie = 1;
444                mHasFds = mFdsKnown = true;
445                if (!mAllowFds) {
446                    err = FDS_NOT_ALLOWED;
447                }
448            }
449        }
450    }
451
452    return err;
453}
454
455bool Parcel::pushAllowFds(bool allowFds)
456{
457    const bool origValue = mAllowFds;
458    if (!allowFds) {
459        mAllowFds = false;
460    }
461    return origValue;
462}
463
464void Parcel::restoreAllowFds(bool lastValue)
465{
466    mAllowFds = lastValue;
467}
468
469bool Parcel::hasFileDescriptors() const
470{
471    if (!mFdsKnown) {
472        scanForFds();
473    }
474    return mHasFds;
475}
476
477// Write RPC headers.  (previously just the interface token)
478status_t Parcel::writeInterfaceToken(const String16& interface)
479{
480    writeInt32(IPCThreadState::self()->getStrictModePolicy() |
481               STRICT_MODE_PENALTY_GATHER);
482    // currently the interface identification token is just its name as a string
483    return writeString16(interface);
484}
485
486bool Parcel::checkInterface(IBinder* binder) const
487{
488    return enforceInterface(binder->getInterfaceDescriptor());
489}
490
491bool Parcel::enforceInterface(const String16& interface,
492                              IPCThreadState* threadState) const
493{
494    int32_t strictPolicy = readInt32();
495    if (threadState == NULL) {
496        threadState = IPCThreadState::self();
497    }
498    if ((threadState->getLastTransactionBinderFlags() &
499         IBinder::FLAG_ONEWAY) != 0) {
500      // For one-way calls, the callee is running entirely
501      // disconnected from the caller, so disable StrictMode entirely.
502      // Not only does disk/network usage not impact the caller, but
503      // there's no way to commuicate back any violations anyway.
504      threadState->setStrictModePolicy(0);
505    } else {
506      threadState->setStrictModePolicy(strictPolicy);
507    }
508    const String16 str(readString16());
509    if (str == interface) {
510        return true;
511    } else {
512        ALOGW("**** enforceInterface() expected '%s' but read '%s'\n",
513                String8(interface).string(), String8(str).string());
514        return false;
515    }
516}
517
518const binder_size_t* Parcel::objects() const
519{
520    return mObjects;
521}
522
523size_t Parcel::objectsCount() const
524{
525    return mObjectsSize;
526}
527
528status_t Parcel::errorCheck() const
529{
530    return mError;
531}
532
533void Parcel::setError(status_t err)
534{
535    mError = err;
536}
537
538status_t Parcel::finishWrite(size_t len)
539{
540    //printf("Finish write of %d\n", len);
541    mDataPos += len;
542    ALOGV("finishWrite Setting data pos of %p to %d\n", this, mDataPos);
543    if (mDataPos > mDataSize) {
544        mDataSize = mDataPos;
545        ALOGV("finishWrite Setting data size of %p to %d\n", this, mDataSize);
546    }
547    //printf("New pos=%d, size=%d\n", mDataPos, mDataSize);
548    return NO_ERROR;
549}
550
551status_t Parcel::writeUnpadded(const void* data, size_t len)
552{
553    size_t end = mDataPos + len;
554    if (end < mDataPos) {
555        // integer overflow
556        return BAD_VALUE;
557    }
558
559    if (end <= mDataCapacity) {
560restart_write:
561        memcpy(mData+mDataPos, data, len);
562        return finishWrite(len);
563    }
564
565    status_t err = growData(len);
566    if (err == NO_ERROR) goto restart_write;
567    return err;
568}
569
570status_t Parcel::write(const void* data, size_t len)
571{
572    void* const d = writeInplace(len);
573    if (d) {
574        memcpy(d, data, len);
575        return NO_ERROR;
576    }
577    return mError;
578}
579
580void* Parcel::writeInplace(size_t len)
581{
582    const size_t padded = PAD_SIZE(len);
583
584    // sanity check for integer overflow
585    if (mDataPos+padded < mDataPos) {
586        return NULL;
587    }
588
589    if ((mDataPos+padded) <= mDataCapacity) {
590restart_write:
591        //printf("Writing %ld bytes, padded to %ld\n", len, padded);
592        uint8_t* const data = mData+mDataPos;
593
594        // Need to pad at end?
595        if (padded != len) {
596#if BYTE_ORDER == BIG_ENDIAN
597            static const uint32_t mask[4] = {
598                0x00000000, 0xffffff00, 0xffff0000, 0xff000000
599            };
600#endif
601#if BYTE_ORDER == LITTLE_ENDIAN
602            static const uint32_t mask[4] = {
603                0x00000000, 0x00ffffff, 0x0000ffff, 0x000000ff
604            };
605#endif
606            //printf("Applying pad mask: %p to %p\n", (void*)mask[padded-len],
607            //    *reinterpret_cast<void**>(data+padded-4));
608            *reinterpret_cast<uint32_t*>(data+padded-4) &= mask[padded-len];
609        }
610
611        finishWrite(padded);
612        return data;
613    }
614
615    status_t err = growData(padded);
616    if (err == NO_ERROR) goto restart_write;
617    return NULL;
618}
619
620status_t Parcel::writeInt32(int32_t val)
621{
622    return writeAligned(val);
623}
624status_t Parcel::writeInt32Array(size_t len, const int32_t *val) {
625    if (!val) {
626        return writeAligned(-1);
627    }
628    status_t ret = writeAligned(len);
629    if (ret == NO_ERROR) {
630        ret = write(val, len * sizeof(*val));
631    }
632    return ret;
633}
634status_t Parcel::writeByteArray(size_t len, const uint8_t *val) {
635    if (!val) {
636        return writeAligned(-1);
637    }
638    status_t ret = writeAligned(len);
639    if (ret == NO_ERROR) {
640        ret = write(val, len * sizeof(*val));
641    }
642    return ret;
643}
644
645status_t Parcel::writeInt64(int64_t val)
646{
647    return writeAligned(val);
648}
649
650status_t Parcel::writePointer(uintptr_t val)
651{
652    return writeAligned<binder_uintptr_t>(val);
653}
654
655status_t Parcel::writeFloat(float val)
656{
657    return writeAligned(val);
658}
659
660#if defined(__mips__) && defined(__mips_hard_float)
661
662status_t Parcel::writeDouble(double val)
663{
664    union {
665        double d;
666        unsigned long long ll;
667    } u;
668    u.d = val;
669    return writeAligned(u.ll);
670}
671
672#else
673
674status_t Parcel::writeDouble(double val)
675{
676    return writeAligned(val);
677}
678
679#endif
680
681status_t Parcel::writeIntPtr(intptr_t val)
682{
683    return writeAligned(val);
684}
685
686status_t Parcel::writeCString(const char* str)
687{
688    return write(str, strlen(str)+1);
689}
690
691status_t Parcel::writeString8(const String8& str)
692{
693    status_t err = writeInt32(str.bytes());
694    // only write string if its length is more than zero characters,
695    // as readString8 will only read if the length field is non-zero.
696    // this is slightly different from how writeString16 works.
697    if (str.bytes() > 0 && err == NO_ERROR) {
698        err = write(str.string(), str.bytes()+1);
699    }
700    return err;
701}
702
703status_t Parcel::writeString16(const String16& str)
704{
705    return writeString16(str.string(), str.size());
706}
707
708status_t Parcel::writeString16(const char16_t* str, size_t len)
709{
710    if (str == NULL) return writeInt32(-1);
711
712    status_t err = writeInt32(len);
713    if (err == NO_ERROR) {
714        len *= sizeof(char16_t);
715        uint8_t* data = (uint8_t*)writeInplace(len+sizeof(char16_t));
716        if (data) {
717            memcpy(data, str, len);
718            *reinterpret_cast<char16_t*>(data+len) = 0;
719            return NO_ERROR;
720        }
721        err = mError;
722    }
723    return err;
724}
725
726status_t Parcel::writeStrongBinder(const sp<IBinder>& val)
727{
728    return flatten_binder(ProcessState::self(), val, this);
729}
730
731status_t Parcel::writeWeakBinder(const wp<IBinder>& val)
732{
733    return flatten_binder(ProcessState::self(), val, this);
734}
735
736status_t Parcel::writeNativeHandle(const native_handle* handle)
737{
738    if (!handle || handle->version != sizeof(native_handle))
739        return BAD_TYPE;
740
741    status_t err;
742    err = writeInt32(handle->numFds);
743    if (err != NO_ERROR) return err;
744
745    err = writeInt32(handle->numInts);
746    if (err != NO_ERROR) return err;
747
748    for (int i=0 ; err==NO_ERROR && i<handle->numFds ; i++)
749        err = writeDupFileDescriptor(handle->data[i]);
750
751    if (err != NO_ERROR) {
752        ALOGD("write native handle, write dup fd failed");
753        return err;
754    }
755    err = write(handle->data + handle->numFds, sizeof(int)*handle->numInts);
756    return err;
757}
758
759status_t Parcel::writeFileDescriptor(int fd, bool takeOwnership)
760{
761    flat_binder_object obj;
762    obj.type = BINDER_TYPE_FD;
763    obj.flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
764    obj.binder = 0; /* Don't pass uninitialized stack data to a remote process */
765    obj.handle = fd;
766    obj.cookie = takeOwnership ? 1 : 0;
767    return writeObject(obj, true);
768}
769
770status_t Parcel::writeDupFileDescriptor(int fd)
771{
772    int dupFd = dup(fd);
773    if (dupFd < 0) {
774        return -errno;
775    }
776    status_t err = writeFileDescriptor(dupFd, true /*takeOwnership*/);
777    if (err) {
778        close(dupFd);
779    }
780    return err;
781}
782
783// WARNING: This method must stay in sync with
784// Parcelable.Creator<ParcelFileDescriptor> CREATOR
785// in frameworks/base/core/java/android/os/ParcelFileDescriptor.java
786status_t Parcel::writeParcelFileDescriptor(int fd, int commChannel) {
787    status_t status;
788
789    if (fd < 0) {
790        status = writeInt32(0); // ParcelFileDescriptor is null
791        if (status) return status;
792    } else {
793        status = writeInt32(1); // ParcelFileDescriptor is not null
794        if (status) return status;
795        status = writeDupFileDescriptor(fd);
796        if (status) return status;
797        if (commChannel < 0) {
798            status = writeInt32(0); // commChannel is null
799            if (status) return status;
800        } else {
801            status = writeInt32(1); // commChannel is not null
802            if (status) return status;
803            status = writeDupFileDescriptor(commChannel);
804        }
805    }
806    return status;
807}
808
809status_t Parcel::writeBlob(size_t len, WritableBlob* outBlob)
810{
811    status_t status;
812
813    if (!mAllowFds || len <= IN_PLACE_BLOB_LIMIT) {
814        ALOGV("writeBlob: write in place");
815        status = writeInt32(0);
816        if (status) return status;
817
818        void* ptr = writeInplace(len);
819        if (!ptr) return NO_MEMORY;
820
821        outBlob->init(false /*mapped*/, ptr, len);
822        return NO_ERROR;
823    }
824
825    ALOGV("writeBlob: write to ashmem");
826    int fd = ashmem_create_region("Parcel Blob", len);
827    if (fd < 0) return NO_MEMORY;
828
829    int result = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE);
830    if (result < 0) {
831        status = result;
832    } else {
833        void* ptr = ::mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
834        if (ptr == MAP_FAILED) {
835            status = -errno;
836        } else {
837            result = ashmem_set_prot_region(fd, PROT_READ);
838            if (result < 0) {
839                status = result;
840            } else {
841                status = writeInt32(1);
842                if (!status) {
843                    status = writeFileDescriptor(fd, true /*takeOwnership*/);
844                    if (!status) {
845                        outBlob->init(true /*mapped*/, ptr, len);
846                        return NO_ERROR;
847                    }
848                }
849            }
850        }
851        ::munmap(ptr, len);
852    }
853    ::close(fd);
854    return status;
855}
856
857status_t Parcel::write(const FlattenableHelperInterface& val)
858{
859    status_t err;
860
861    // size if needed
862    const size_t len = val.getFlattenedSize();
863    const size_t fd_count = val.getFdCount();
864
865    err = this->writeInt32(len);
866    if (err) return err;
867
868    err = this->writeInt32(fd_count);
869    if (err) return err;
870
871    // payload
872    void* const buf = this->writeInplace(PAD_SIZE(len));
873    if (buf == NULL)
874        return BAD_VALUE;
875
876    int* fds = NULL;
877    if (fd_count) {
878        fds = new int[fd_count];
879    }
880
881    err = val.flatten(buf, len, fds, fd_count);
882    for (size_t i=0 ; i<fd_count && err==NO_ERROR ; i++) {
883        err = this->writeDupFileDescriptor( fds[i] );
884    }
885
886    if (fd_count) {
887        delete [] fds;
888    }
889
890    return err;
891}
892
893status_t Parcel::writeObject(const flat_binder_object& val, bool nullMetaData)
894{
895    const bool enoughData = (mDataPos+sizeof(val)) <= mDataCapacity;
896    const bool enoughObjects = mObjectsSize < mObjectsCapacity;
897    if (enoughData && enoughObjects) {
898restart_write:
899        *reinterpret_cast<flat_binder_object*>(mData+mDataPos) = val;
900
901        // Need to write meta-data?
902        if (nullMetaData || val.binder != 0) {
903            mObjects[mObjectsSize] = mDataPos;
904            acquire_object(ProcessState::self(), val, this);
905            mObjectsSize++;
906        }
907
908        // remember if it's a file descriptor
909        if (val.type == BINDER_TYPE_FD) {
910            if (!mAllowFds) {
911                return FDS_NOT_ALLOWED;
912            }
913            mHasFds = mFdsKnown = true;
914        }
915
916        return finishWrite(sizeof(flat_binder_object));
917    }
918
919    if (!enoughData) {
920        const status_t err = growData(sizeof(val));
921        if (err != NO_ERROR) return err;
922    }
923    if (!enoughObjects) {
924        size_t newSize = ((mObjectsSize+2)*3)/2;
925        binder_size_t* objects = (binder_size_t*)realloc(mObjects, newSize*sizeof(binder_size_t));
926        if (objects == NULL) return NO_MEMORY;
927        mObjects = objects;
928        mObjectsCapacity = newSize;
929    }
930
931    goto restart_write;
932}
933
934status_t Parcel::writeNoException()
935{
936    return writeInt32(0);
937}
938
939void Parcel::remove(size_t /*start*/, size_t /*amt*/)
940{
941    LOG_ALWAYS_FATAL("Parcel::remove() not yet implemented!");
942}
943
944status_t Parcel::read(void* outData, size_t len) const
945{
946    if ((mDataPos+PAD_SIZE(len)) >= mDataPos && (mDataPos+PAD_SIZE(len)) <= mDataSize) {
947        memcpy(outData, mData+mDataPos, len);
948        mDataPos += PAD_SIZE(len);
949        ALOGV("read Setting data pos of %p to %d\n", this, mDataPos);
950        return NO_ERROR;
951    }
952    return NOT_ENOUGH_DATA;
953}
954
955const void* Parcel::readInplace(size_t len) const
956{
957    if ((mDataPos+PAD_SIZE(len)) >= mDataPos && (mDataPos+PAD_SIZE(len)) <= mDataSize) {
958        const void* data = mData+mDataPos;
959        mDataPos += PAD_SIZE(len);
960        ALOGV("readInplace Setting data pos of %p to %d\n", this, mDataPos);
961        return data;
962    }
963    return NULL;
964}
965
966template<class T>
967status_t Parcel::readAligned(T *pArg) const {
968    COMPILE_TIME_ASSERT_FUNCTION_SCOPE(PAD_SIZE(sizeof(T)) == sizeof(T));
969
970    if ((mDataPos+sizeof(T)) <= mDataSize) {
971        const void* data = mData+mDataPos;
972        mDataPos += sizeof(T);
973        *pArg =  *reinterpret_cast<const T*>(data);
974        return NO_ERROR;
975    } else {
976        return NOT_ENOUGH_DATA;
977    }
978}
979
980template<class T>
981T Parcel::readAligned() const {
982    T result;
983    if (readAligned(&result) != NO_ERROR) {
984        result = 0;
985    }
986
987    return result;
988}
989
990template<class T>
991status_t Parcel::writeAligned(T val) {
992    COMPILE_TIME_ASSERT_FUNCTION_SCOPE(PAD_SIZE(sizeof(T)) == sizeof(T));
993
994    if ((mDataPos+sizeof(val)) <= mDataCapacity) {
995restart_write:
996        *reinterpret_cast<T*>(mData+mDataPos) = val;
997        return finishWrite(sizeof(val));
998    }
999
1000    status_t err = growData(sizeof(val));
1001    if (err == NO_ERROR) goto restart_write;
1002    return err;
1003}
1004
1005status_t Parcel::readInt32(int32_t *pArg) const
1006{
1007    return readAligned(pArg);
1008}
1009
1010int32_t Parcel::readInt32() const
1011{
1012    return readAligned<int32_t>();
1013}
1014
1015
1016status_t Parcel::readInt64(int64_t *pArg) const
1017{
1018    return readAligned(pArg);
1019}
1020
1021
1022int64_t Parcel::readInt64() const
1023{
1024    return readAligned<int64_t>();
1025}
1026
1027status_t Parcel::readPointer(uintptr_t *pArg) const
1028{
1029    status_t ret;
1030    binder_uintptr_t ptr;
1031    ret = readAligned(&ptr);
1032    if (!ret)
1033        *pArg = ptr;
1034    return ret;
1035}
1036
1037uintptr_t Parcel::readPointer() const
1038{
1039    return readAligned<binder_uintptr_t>();
1040}
1041
1042
1043status_t Parcel::readFloat(float *pArg) const
1044{
1045    return readAligned(pArg);
1046}
1047
1048
1049float Parcel::readFloat() const
1050{
1051    return readAligned<float>();
1052}
1053
1054#if defined(__mips__) && defined(__mips_hard_float)
1055
1056status_t Parcel::readDouble(double *pArg) const
1057{
1058    union {
1059      double d;
1060      unsigned long long ll;
1061    } u;
1062    status_t status;
1063    status = readAligned(&u.ll);
1064    *pArg = u.d;
1065    return status;
1066}
1067
1068double Parcel::readDouble() const
1069{
1070    union {
1071      double d;
1072      unsigned long long ll;
1073    } u;
1074    u.ll = readAligned<unsigned long long>();
1075    return u.d;
1076}
1077
1078#else
1079
1080status_t Parcel::readDouble(double *pArg) const
1081{
1082    return readAligned(pArg);
1083}
1084
1085double Parcel::readDouble() const
1086{
1087    return readAligned<double>();
1088}
1089
1090#endif
1091
1092status_t Parcel::readIntPtr(intptr_t *pArg) const
1093{
1094    return readAligned(pArg);
1095}
1096
1097
1098intptr_t Parcel::readIntPtr() const
1099{
1100    return readAligned<intptr_t>();
1101}
1102
1103
1104const char* Parcel::readCString() const
1105{
1106    const size_t avail = mDataSize-mDataPos;
1107    if (avail > 0) {
1108        const char* str = reinterpret_cast<const char*>(mData+mDataPos);
1109        // is the string's trailing NUL within the parcel's valid bounds?
1110        const char* eos = reinterpret_cast<const char*>(memchr(str, 0, avail));
1111        if (eos) {
1112            const size_t len = eos - str;
1113            mDataPos += PAD_SIZE(len+1);
1114            ALOGV("readCString Setting data pos of %p to %d\n", this, mDataPos);
1115            return str;
1116        }
1117    }
1118    return NULL;
1119}
1120
1121String8 Parcel::readString8() const
1122{
1123    int32_t size = readInt32();
1124    // watch for potential int overflow adding 1 for trailing NUL
1125    if (size > 0 && size < INT32_MAX) {
1126        const char* str = (const char*)readInplace(size+1);
1127        if (str) return String8(str, size);
1128    }
1129    return String8();
1130}
1131
1132String16 Parcel::readString16() const
1133{
1134    size_t len;
1135    const char16_t* str = readString16Inplace(&len);
1136    if (str) return String16(str, len);
1137    ALOGE("Reading a NULL string not supported here.");
1138    return String16();
1139}
1140
1141const char16_t* Parcel::readString16Inplace(size_t* outLen) const
1142{
1143    int32_t size = readInt32();
1144    // watch for potential int overflow from size+1
1145    if (size >= 0 && size < INT32_MAX) {
1146        *outLen = size;
1147        const char16_t* str = (const char16_t*)readInplace((size+1)*sizeof(char16_t));
1148        if (str != NULL) {
1149            return str;
1150        }
1151    }
1152    *outLen = 0;
1153    return NULL;
1154}
1155
1156sp<IBinder> Parcel::readStrongBinder() const
1157{
1158    sp<IBinder> val;
1159    unflatten_binder(ProcessState::self(), *this, &val);
1160    return val;
1161}
1162
1163wp<IBinder> Parcel::readWeakBinder() const
1164{
1165    wp<IBinder> val;
1166    unflatten_binder(ProcessState::self(), *this, &val);
1167    return val;
1168}
1169
1170int32_t Parcel::readExceptionCode() const
1171{
1172  int32_t exception_code = readAligned<int32_t>();
1173  if (exception_code == EX_HAS_REPLY_HEADER) {
1174    int32_t header_start = dataPosition();
1175    int32_t header_size = readAligned<int32_t>();
1176    // Skip over fat responses headers.  Not used (or propagated) in
1177    // native code
1178    setDataPosition(header_start + header_size);
1179    // And fat response headers are currently only used when there are no
1180    // exceptions, so return no error:
1181    return 0;
1182  }
1183  return exception_code;
1184}
1185
1186native_handle* Parcel::readNativeHandle() const
1187{
1188    int numFds, numInts;
1189    status_t err;
1190    err = readInt32(&numFds);
1191    if (err != NO_ERROR) return 0;
1192    err = readInt32(&numInts);
1193    if (err != NO_ERROR) return 0;
1194
1195    native_handle* h = native_handle_create(numFds, numInts);
1196    for (int i=0 ; err==NO_ERROR && i<numFds ; i++) {
1197        h->data[i] = dup(readFileDescriptor());
1198        if (h->data[i] < 0) err = BAD_VALUE;
1199    }
1200    err = read(h->data + numFds, sizeof(int)*numInts);
1201    if (err != NO_ERROR) {
1202        native_handle_close(h);
1203        native_handle_delete(h);
1204        h = 0;
1205    }
1206    return h;
1207}
1208
1209
1210int Parcel::readFileDescriptor() const
1211{
1212    const flat_binder_object* flat = readObject(true);
1213    if (flat) {
1214        switch (flat->type) {
1215            case BINDER_TYPE_FD:
1216                //ALOGI("Returning file descriptor %ld from parcel %p\n", flat->handle, this);
1217                return flat->handle;
1218        }
1219    }
1220    return BAD_TYPE;
1221}
1222
1223// WARNING: This method must stay in sync with writeToParcel()
1224// in frameworks/base/core/java/android/os/ParcelFileDescriptor.java
1225int Parcel::readParcelFileDescriptor(int& outCommChannel) const {
1226    int fd;
1227    outCommChannel = -1;
1228
1229    if (readInt32() == 0) {
1230        fd = -1;
1231    } else {
1232        fd = readFileDescriptor();
1233        if (fd >= 0 && readInt32() != 0) {
1234            outCommChannel = readFileDescriptor();
1235        }
1236    }
1237    return fd;
1238}
1239
1240status_t Parcel::readBlob(size_t len, ReadableBlob* outBlob) const
1241{
1242    int32_t useAshmem;
1243    status_t status = readInt32(&useAshmem);
1244    if (status) return status;
1245
1246    if (!useAshmem) {
1247        ALOGV("readBlob: read in place");
1248        const void* ptr = readInplace(len);
1249        if (!ptr) return BAD_VALUE;
1250
1251        outBlob->init(false /*mapped*/, const_cast<void*>(ptr), len);
1252        return NO_ERROR;
1253    }
1254
1255    ALOGV("readBlob: read from ashmem");
1256    int fd = readFileDescriptor();
1257    if (fd == int(BAD_TYPE)) return BAD_VALUE;
1258
1259    void* ptr = ::mmap(NULL, len, PROT_READ, MAP_SHARED, fd, 0);
1260    if (!ptr) return NO_MEMORY;
1261
1262    outBlob->init(true /*mapped*/, ptr, len);
1263    return NO_ERROR;
1264}
1265
1266status_t Parcel::read(FlattenableHelperInterface& val) const
1267{
1268    // size
1269    const size_t len = this->readInt32();
1270    const size_t fd_count = this->readInt32();
1271
1272    // payload
1273    void const* const buf = this->readInplace(PAD_SIZE(len));
1274    if (buf == NULL)
1275        return BAD_VALUE;
1276
1277    int* fds = NULL;
1278    if (fd_count) {
1279        fds = new int[fd_count];
1280    }
1281
1282    status_t err = NO_ERROR;
1283    for (size_t i=0 ; i<fd_count && err==NO_ERROR ; i++) {
1284        fds[i] = dup(this->readFileDescriptor());
1285        if (fds[i] < 0) err = BAD_VALUE;
1286    }
1287
1288    if (err == NO_ERROR) {
1289        err = val.unflatten(buf, len, fds, fd_count);
1290    }
1291
1292    if (fd_count) {
1293        delete [] fds;
1294    }
1295
1296    return err;
1297}
1298const flat_binder_object* Parcel::readObject(bool nullMetaData) const
1299{
1300    const size_t DPOS = mDataPos;
1301    if ((DPOS+sizeof(flat_binder_object)) <= mDataSize) {
1302        const flat_binder_object* obj
1303                = reinterpret_cast<const flat_binder_object*>(mData+DPOS);
1304        mDataPos = DPOS + sizeof(flat_binder_object);
1305        if (!nullMetaData && (obj->cookie == 0 && obj->binder == 0)) {
1306            // When transferring a NULL object, we don't write it into
1307            // the object list, so we don't want to check for it when
1308            // reading.
1309            ALOGV("readObject Setting data pos of %p to %d\n", this, mDataPos);
1310            return obj;
1311        }
1312
1313        // Ensure that this object is valid...
1314        binder_size_t* const OBJS = mObjects;
1315        const size_t N = mObjectsSize;
1316        size_t opos = mNextObjectHint;
1317
1318        if (N > 0) {
1319            ALOGV("Parcel %p looking for obj at %d, hint=%d\n",
1320                 this, DPOS, opos);
1321
1322            // Start at the current hint position, looking for an object at
1323            // the current data position.
1324            if (opos < N) {
1325                while (opos < (N-1) && OBJS[opos] < DPOS) {
1326                    opos++;
1327                }
1328            } else {
1329                opos = N-1;
1330            }
1331            if (OBJS[opos] == DPOS) {
1332                // Found it!
1333                ALOGV("Parcel found obj %d at index %d with forward search",
1334                     this, DPOS, opos);
1335                mNextObjectHint = opos+1;
1336                ALOGV("readObject Setting data pos of %p to %d\n", this, mDataPos);
1337                return obj;
1338            }
1339
1340            // Look backwards for it...
1341            while (opos > 0 && OBJS[opos] > DPOS) {
1342                opos--;
1343            }
1344            if (OBJS[opos] == DPOS) {
1345                // Found it!
1346                ALOGV("Parcel found obj %d at index %d with backward search",
1347                     this, DPOS, opos);
1348                mNextObjectHint = opos+1;
1349                ALOGV("readObject Setting data pos of %p to %d\n", this, mDataPos);
1350                return obj;
1351            }
1352        }
1353        ALOGW("Attempt to read object from Parcel %p at offset %zu that is not in the object list",
1354             this, DPOS);
1355    }
1356    return NULL;
1357}
1358
1359void Parcel::closeFileDescriptors()
1360{
1361    size_t i = mObjectsSize;
1362    if (i > 0) {
1363        //ALOGI("Closing file descriptors for %d objects...", mObjectsSize);
1364    }
1365    while (i > 0) {
1366        i--;
1367        const flat_binder_object* flat
1368            = reinterpret_cast<flat_binder_object*>(mData+mObjects[i]);
1369        if (flat->type == BINDER_TYPE_FD) {
1370            //ALOGI("Closing fd: %ld\n", flat->handle);
1371            close(flat->handle);
1372        }
1373    }
1374}
1375
1376uintptr_t Parcel::ipcData() const
1377{
1378    return reinterpret_cast<uintptr_t>(mData);
1379}
1380
1381size_t Parcel::ipcDataSize() const
1382{
1383    return (mDataSize > mDataPos ? mDataSize : mDataPos);
1384}
1385
1386uintptr_t Parcel::ipcObjects() const
1387{
1388    return reinterpret_cast<uintptr_t>(mObjects);
1389}
1390
1391size_t Parcel::ipcObjectsCount() const
1392{
1393    return mObjectsSize;
1394}
1395
1396void Parcel::ipcSetDataReference(const uint8_t* data, size_t dataSize,
1397    const binder_size_t* objects, size_t objectsCount, release_func relFunc, void* relCookie)
1398{
1399    binder_size_t minOffset = 0;
1400    freeDataNoInit();
1401    mError = NO_ERROR;
1402    mData = const_cast<uint8_t*>(data);
1403    mDataSize = mDataCapacity = dataSize;
1404    //ALOGI("setDataReference Setting data size of %p to %lu (pid=%d)\n", this, mDataSize, getpid());
1405    mDataPos = 0;
1406    ALOGV("setDataReference Setting data pos of %p to %d\n", this, mDataPos);
1407    mObjects = const_cast<binder_size_t*>(objects);
1408    mObjectsSize = mObjectsCapacity = objectsCount;
1409    mNextObjectHint = 0;
1410    mOwner = relFunc;
1411    mOwnerCookie = relCookie;
1412    for (size_t i = 0; i < mObjectsSize; i++) {
1413        binder_size_t offset = mObjects[i];
1414        if (offset < minOffset) {
1415            ALOGE("%s: bad object offset %"PRIu64" < %"PRIu64"\n",
1416                  __func__, (uint64_t)offset, (uint64_t)minOffset);
1417            mObjectsSize = 0;
1418            break;
1419        }
1420        minOffset = offset + sizeof(flat_binder_object);
1421    }
1422    scanForFds();
1423}
1424
1425void Parcel::print(TextOutput& to, uint32_t /*flags*/) const
1426{
1427    to << "Parcel(";
1428
1429    if (errorCheck() != NO_ERROR) {
1430        const status_t err = errorCheck();
1431        to << "Error: " << (void*)(intptr_t)err << " \"" << strerror(-err) << "\"";
1432    } else if (dataSize() > 0) {
1433        const uint8_t* DATA = data();
1434        to << indent << HexDump(DATA, dataSize()) << dedent;
1435        const binder_size_t* OBJS = objects();
1436        const size_t N = objectsCount();
1437        for (size_t i=0; i<N; i++) {
1438            const flat_binder_object* flat
1439                = reinterpret_cast<const flat_binder_object*>(DATA+OBJS[i]);
1440            to << endl << "Object #" << i << " @ " << (void*)OBJS[i] << ": "
1441                << TypeCode(flat->type & 0x7f7f7f00)
1442                << " = " << flat->binder;
1443        }
1444    } else {
1445        to << "NULL";
1446    }
1447
1448    to << ")";
1449}
1450
1451void Parcel::releaseObjects()
1452{
1453    const sp<ProcessState> proc(ProcessState::self());
1454    size_t i = mObjectsSize;
1455    uint8_t* const data = mData;
1456    binder_size_t* const objects = mObjects;
1457    while (i > 0) {
1458        i--;
1459        const flat_binder_object* flat
1460            = reinterpret_cast<flat_binder_object*>(data+objects[i]);
1461        release_object(proc, *flat, this);
1462    }
1463}
1464
1465void Parcel::acquireObjects()
1466{
1467    const sp<ProcessState> proc(ProcessState::self());
1468    size_t i = mObjectsSize;
1469    uint8_t* const data = mData;
1470    binder_size_t* const objects = mObjects;
1471    while (i > 0) {
1472        i--;
1473        const flat_binder_object* flat
1474            = reinterpret_cast<flat_binder_object*>(data+objects[i]);
1475        acquire_object(proc, *flat, this);
1476    }
1477}
1478
1479void Parcel::freeData()
1480{
1481    freeDataNoInit();
1482    initState();
1483}
1484
1485void Parcel::freeDataNoInit()
1486{
1487    if (mOwner) {
1488        //ALOGI("Freeing data ref of %p (pid=%d)\n", this, getpid());
1489        mOwner(this, mData, mDataSize, mObjects, mObjectsSize, mOwnerCookie);
1490    } else {
1491        releaseObjects();
1492        if (mData) free(mData);
1493        if (mObjects) free(mObjects);
1494    }
1495}
1496
1497status_t Parcel::growData(size_t len)
1498{
1499    size_t newSize = ((mDataSize+len)*3)/2;
1500    return (newSize <= mDataSize)
1501            ? (status_t) NO_MEMORY
1502            : continueWrite(newSize);
1503}
1504
1505status_t Parcel::restartWrite(size_t desired)
1506{
1507    if (mOwner) {
1508        freeData();
1509        return continueWrite(desired);
1510    }
1511
1512    uint8_t* data = (uint8_t*)realloc(mData, desired);
1513    if (!data && desired > mDataCapacity) {
1514        mError = NO_MEMORY;
1515        return NO_MEMORY;
1516    }
1517
1518    releaseObjects();
1519
1520    if (data) {
1521        mData = data;
1522        mDataCapacity = desired;
1523    }
1524
1525    mDataSize = mDataPos = 0;
1526    ALOGV("restartWrite Setting data size of %p to %d\n", this, mDataSize);
1527    ALOGV("restartWrite Setting data pos of %p to %d\n", this, mDataPos);
1528
1529    free(mObjects);
1530    mObjects = NULL;
1531    mObjectsSize = mObjectsCapacity = 0;
1532    mNextObjectHint = 0;
1533    mHasFds = false;
1534    mFdsKnown = true;
1535    mAllowFds = true;
1536
1537    return NO_ERROR;
1538}
1539
1540status_t Parcel::continueWrite(size_t desired)
1541{
1542    // If shrinking, first adjust for any objects that appear
1543    // after the new data size.
1544    size_t objectsSize = mObjectsSize;
1545    if (desired < mDataSize) {
1546        if (desired == 0) {
1547            objectsSize = 0;
1548        } else {
1549            while (objectsSize > 0) {
1550                if (mObjects[objectsSize-1] < desired)
1551                    break;
1552                objectsSize--;
1553            }
1554        }
1555    }
1556
1557    if (mOwner) {
1558        // If the size is going to zero, just release the owner's data.
1559        if (desired == 0) {
1560            freeData();
1561            return NO_ERROR;
1562        }
1563
1564        // If there is a different owner, we need to take
1565        // posession.
1566        uint8_t* data = (uint8_t*)malloc(desired);
1567        if (!data) {
1568            mError = NO_MEMORY;
1569            return NO_MEMORY;
1570        }
1571        binder_size_t* objects = NULL;
1572
1573        if (objectsSize) {
1574            objects = (binder_size_t*)malloc(objectsSize*sizeof(binder_size_t));
1575            if (!objects) {
1576                free(data);
1577
1578                mError = NO_MEMORY;
1579                return NO_MEMORY;
1580            }
1581
1582            // Little hack to only acquire references on objects
1583            // we will be keeping.
1584            size_t oldObjectsSize = mObjectsSize;
1585            mObjectsSize = objectsSize;
1586            acquireObjects();
1587            mObjectsSize = oldObjectsSize;
1588        }
1589
1590        if (mData) {
1591            memcpy(data, mData, mDataSize < desired ? mDataSize : desired);
1592        }
1593        if (objects && mObjects) {
1594            memcpy(objects, mObjects, objectsSize*sizeof(binder_size_t));
1595        }
1596        //ALOGI("Freeing data ref of %p (pid=%d)\n", this, getpid());
1597        mOwner(this, mData, mDataSize, mObjects, mObjectsSize, mOwnerCookie);
1598        mOwner = NULL;
1599
1600        mData = data;
1601        mObjects = objects;
1602        mDataSize = (mDataSize < desired) ? mDataSize : desired;
1603        ALOGV("continueWrite Setting data size of %p to %d\n", this, mDataSize);
1604        mDataCapacity = desired;
1605        mObjectsSize = mObjectsCapacity = objectsSize;
1606        mNextObjectHint = 0;
1607
1608    } else if (mData) {
1609        if (objectsSize < mObjectsSize) {
1610            // Need to release refs on any objects we are dropping.
1611            const sp<ProcessState> proc(ProcessState::self());
1612            for (size_t i=objectsSize; i<mObjectsSize; i++) {
1613                const flat_binder_object* flat
1614                    = reinterpret_cast<flat_binder_object*>(mData+mObjects[i]);
1615                if (flat->type == BINDER_TYPE_FD) {
1616                    // will need to rescan because we may have lopped off the only FDs
1617                    mFdsKnown = false;
1618                }
1619                release_object(proc, *flat, this);
1620            }
1621            binder_size_t* objects =
1622                (binder_size_t*)realloc(mObjects, objectsSize*sizeof(binder_size_t));
1623            if (objects) {
1624                mObjects = objects;
1625            }
1626            mObjectsSize = objectsSize;
1627            mNextObjectHint = 0;
1628        }
1629
1630        // We own the data, so we can just do a realloc().
1631        if (desired > mDataCapacity) {
1632            uint8_t* data = (uint8_t*)realloc(mData, desired);
1633            if (data) {
1634                mData = data;
1635                mDataCapacity = desired;
1636            } else if (desired > mDataCapacity) {
1637                mError = NO_MEMORY;
1638                return NO_MEMORY;
1639            }
1640        } else {
1641            if (mDataSize > desired) {
1642                mDataSize = desired;
1643                ALOGV("continueWrite Setting data size of %p to %d\n", this, mDataSize);
1644            }
1645            if (mDataPos > desired) {
1646                mDataPos = desired;
1647                ALOGV("continueWrite Setting data pos of %p to %d\n", this, mDataPos);
1648            }
1649        }
1650
1651    } else {
1652        // This is the first data.  Easy!
1653        uint8_t* data = (uint8_t*)malloc(desired);
1654        if (!data) {
1655            mError = NO_MEMORY;
1656            return NO_MEMORY;
1657        }
1658
1659        if(!(mDataCapacity == 0 && mObjects == NULL
1660             && mObjectsCapacity == 0)) {
1661            ALOGE("continueWrite: %zu/%p/%zu/%zu", mDataCapacity, mObjects, mObjectsCapacity, desired);
1662        }
1663
1664        mData = data;
1665        mDataSize = mDataPos = 0;
1666        ALOGV("continueWrite Setting data size of %p to %d\n", this, mDataSize);
1667        ALOGV("continueWrite Setting data pos of %p to %d\n", this, mDataPos);
1668        mDataCapacity = desired;
1669    }
1670
1671    return NO_ERROR;
1672}
1673
1674void Parcel::initState()
1675{
1676    mError = NO_ERROR;
1677    mData = 0;
1678    mDataSize = 0;
1679    mDataCapacity = 0;
1680    mDataPos = 0;
1681    ALOGV("initState Setting data size of %p to %d\n", this, mDataSize);
1682    ALOGV("initState Setting data pos of %p to %d\n", this, mDataPos);
1683    mObjects = NULL;
1684    mObjectsSize = 0;
1685    mObjectsCapacity = 0;
1686    mNextObjectHint = 0;
1687    mHasFds = false;
1688    mFdsKnown = true;
1689    mAllowFds = true;
1690    mOwner = NULL;
1691}
1692
1693void Parcel::scanForFds() const
1694{
1695    bool hasFds = false;
1696    for (size_t i=0; i<mObjectsSize; i++) {
1697        const flat_binder_object* flat
1698            = reinterpret_cast<const flat_binder_object*>(mData + mObjects[i]);
1699        if (flat->type == BINDER_TYPE_FD) {
1700            hasFds = true;
1701            break;
1702        }
1703    }
1704    mHasFds = hasFds;
1705    mFdsKnown = true;
1706}
1707
1708// --- Parcel::Blob ---
1709
1710Parcel::Blob::Blob() :
1711        mMapped(false), mData(NULL), mSize(0) {
1712}
1713
1714Parcel::Blob::~Blob() {
1715    release();
1716}
1717
1718void Parcel::Blob::release() {
1719    if (mMapped && mData) {
1720        ::munmap(mData, mSize);
1721    }
1722    clear();
1723}
1724
1725void Parcel::Blob::init(bool mapped, void* data, size_t size) {
1726    mMapped = mapped;
1727    mData = data;
1728    mSize = size;
1729}
1730
1731void Parcel::Blob::clear() {
1732    mMapped = false;
1733    mData = NULL;
1734    mSize = 0;
1735}
1736
1737}; // namespace android
1738