一般我们对android手机进行权限拦截一般都会对三个服务进程进行inject和hook行为。
com.android.phone=与通信功能相关的短信、电话服务
/system/bin/mediaserver=与媒体功能相关的视频、音频服务
system_server=其他服务,如地理位置、蓝牙、网络连接、程序安装卸载等
他们都是binder服务的结构,并且遵循binder ipc通讯机制。
说了半天先看看源码:
binder.h
/* Copyright 2008 The Android Open Source Project
*/
#ifndef _BINDER_H_
#define _BINDER_H_
#include <sys/ioctl.h>
#include <linux/binder.h>
struct binder_state;
struct binder_object
{
uint32_t type;
uint32_t flags;
void *pointer;
void *cookie;
};
struct binder_txn
{
void *target;
void *cookie;
uint32_t code;
uint32_t flags;
uint32_t sender_pid;
uint32_t sender_euid;
uint32_t data_size;
uint32_t offs_size;
void *data;
void *offs;
};
struct binder_io
{
char *data; /* pointer to read/write from */
uint32_t *offs; /* array of offsets */
uint32_t data_avail; /* bytes available in data buffer */
uint32_t offs_avail; /* entries available in offsets array */
char *data0; /* start of data buffer */
uint32_t *offs0; /* start of offsets buffer */
uint32_t flags;
uint32_t unused;
};
struct binder_death {
void (*func)(struct binder_state *bs, void *ptr);
void *ptr;
};
/* the one magic object */
#define BINDER_SERVICE_MANAGER ((void*) 0)
#define SVC_MGR_NAME "android.os.IServiceManager"
enum {
SVC_MGR_GET_SERVICE = 1,
SVC_MGR_CHECK_SERVICE,
SVC_MGR_ADD_SERVICE,
SVC_MGR_LIST_SERVICES,
};
typedef int (*binder_handler)(struct binder_state *bs,
struct binder_txn *txn,
struct binder_io *msg,
struct binder_io *reply);
struct binder_state *binder_open(unsigned mapsize);
void binder_close(struct binder_state *bs);
/* initiate a blocking binder call
* - returns zero on success
*/
int binder_call(struct binder_state *bs,
struct binder_io *msg, struct binder_io *reply,
void *target, uint32_t code);
/* release any state associate with the binder_io
* - call once any necessary data has been extracted from the
* binder_io after binder_call() returns
* - can safely be called even if binder_call() fails
*/
void binder_done(struct binder_state *bs,
struct binder_io *msg, struct binder_io *reply);
// 增加一个转换函数
void bio_init_from_txn(struct binder_io *io, struct binder_txn *txn);
/* manipulate strong references */
void binder_acquire(struct binder_state *bs, void *ptr);
void binder_release(struct binder_state *bs, void *ptr);
void binder_link_to_death(struct binder_state *bs, void *ptr, struct binder_death *death);
void binder_loop(struct binder_state *bs, binder_handler func);
int binder_become_context_manager(struct binder_state *bs);
/* allocate a binder_io, providing a stack-allocated working
* buffer, size of the working buffer, and how many object
* offset entries to reserve from the buffer
*/
void bio_init(struct binder_io *bio, void *data,
uint32_t maxdata, uint32_t maxobjects);
void bio_destroy(struct binder_io *bio);
void bio_put_obj(struct binder_io *bio, void *ptr);
void bio_put_ref(struct binder_io *bio, void *ptr);
void bio_put_uint32(struct binder_io *bio, uint32_t n);
void bio_put_string16(struct binder_io *bio, const uint16_t *str);
void bio_put_string16_x(struct binder_io *bio, const char *_str);
uint32_t bio_get_uint32(struct binder_io *bio);
uint16_t *bio_get_string16(struct binder_io *bio, uint32_t *sz);
void *bio_get_obj(struct binder_io *bio);
void *bio_get_ref(struct binder_io *bio);
#endif
binder.c
/* Copyright 2008 The Android Open Source Project
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include "binder.h"
#include "log.h"
#define MAX_BIO_SIZE (1 << 30)
#define TRACE 0
//#define LOG_TAG "SPhoneBinder"
#include <cutils/log.h>
#if TRACE
void hexdump(void *_data, unsigned len)
{
unsigned char *data = _data;
unsigned count;
for (count = 0; count < len; count++) {
if ((count & 15) == 0)
fprintf(stderr,"%04x:", count);
fprintf(stderr," %02x %c", *data,
(*data < 32) || (*data > 126) ? '.' : *data);
data++;
if ((count & 15) == 15)
fprintf(stderr,"\n");
}
if ((count & 15) != 0)
fprintf(stderr,"\n");
}
void binder_dump_txn(struct binder_txn *txn)
{
struct binder_object *obj;
unsigned *offs = txn->offs;
unsigned count = txn->offs_size / 4;
fprintf(stderr," target %p cookie %p code %08x flags %08x\n",
txn->target, txn->cookie, txn->code, txn->flags);
fprintf(stderr," pid %8d uid %8d data %8d offs %8d\n",
txn->sender_pid, txn->sender_euid, txn->data_size, txn->offs_size);
hexdump(txn->data, txn->data_size);
while (count--) {
obj = (void*) (((char*) txn->data) + *offs++);
fprintf(stderr," - type %08x flags %08x ptr %p cookie %p\n",
obj->type, obj->flags, obj->pointer, obj->cookie);
}
}
#define NAME(n) case n: return #n
const char *cmd_name(uint32_t cmd)
{
switch(cmd) {
NAME(BR_NOOP);
NAME(BR_TRANSACTION_COMPLETE);
NAME(BR_INCREFS);
NAME(BR_ACQUIRE);
NAME(BR_RELEASE);
NAME(BR_DECREFS);
NAME(BR_TRANSACTION);
NAME(BR_REPLY);
NAME(BR_FAILED_REPLY);
NAME(BR_DEAD_REPLY);
NAME(BR_DEAD_BINDER);
default: return "???";
}
}
#else
#define hexdump(a,b) do{} while (0)
#define binder_dump_txn(txn) do{} while (0)
#endif
#define BIO_F_SHARED 0x01 /* needs to be buffer freed */
#define BIO_F_OVERFLOW 0x02 /* ran out of space */
#define BIO_F_IOERROR 0x04
#define BIO_F_MALLOCED 0x08 /* needs to be free()'d */
struct binder_state
{
int fd;
void *mapped;
unsigned mapsize;
};
struct binder_state *binder_open(unsigned mapsize)
{
struct binder_state *bs;
bs = malloc(sizeof(*bs));
if (!bs) {
errno = ENOMEM;
return 0;
}
bs->fd = open("/dev/binder", O_RDWR);
if (bs->fd < 0) {
fprintf(stderr,"binder: cannot open device (%s)\n",
strerror(errno));
goto fail_open;
}
bs->mapsize = mapsize;
bs->mapped = mmap(NULL, mapsize, PROT_READ, MAP_PRIVATE, bs->fd, 0);
if (bs->mapped == MAP_FAILED) {
fprintf(stderr,"binder: cannot map device (%s)\n",
strerror(errno));
goto fail_map;
}
/* TODO: check version */
return bs;
fail_map:
close(bs->fd);
fail_open:
free(bs);
return 0;
}
void binder_close(struct binder_state *bs)
{
munmap(bs->mapped, bs->mapsize);
close(bs->fd);
free(bs);
}
int binder_become_context_manager(struct binder_state *bs)
{
return ioctl(bs->fd, BINDER_SET_CONTEXT_MGR, 0);
}
int binder_write(struct binder_state *bs, void *data, unsigned len)
{
struct binder_write_read bwr;
int res;
bwr.write_size = len;
bwr.write_consumed = 0;
bwr.write_buffer = (unsigned) data;
bwr.read_size = 0;
bwr.read_consumed = 0;
bwr.read_buffer = 0;
res = ioctl(bs->fd, BINDER_WRITE_READ, &bwr);
if (res < 0) {
fprintf(stderr,"binder_write: ioctl failed (%s)\n",
strerror(errno));
}
return res;
}
void binder_send_reply(struct binder_state *bs,
struct binder_io *reply,
void *buffer_to_free,
int status)
{
struct {
uint32_t cmd_free;
void *buffer;
uint32_t cmd_reply;
struct binder_txn txn;
} __attribute__((packed)) data;
data.cmd_free = BC_FREE_BUFFER;
data.buffer = buffer_to_free;
data.cmd_reply = BC_REPLY;
data.txn.target = 0;
data.txn.cookie = 0;
data.txn.code = 0;
if (status) {
data.txn.flags = TF_STATUS_CODE;
data.txn.data_size = sizeof(int);
data.txn.offs_size = 0;
data.txn.data = &status;
data.txn.offs = 0;
} else {
data.txn.flags = 0;
data.txn.data_size = reply->data - reply->data0;
data.txn.offs_size = ((char*) reply->offs) - ((char*) reply->offs0);
data.txn.data = reply->data0;
data.txn.offs = reply->offs0;
}
binder_write(bs, &data, sizeof(data));
}
int binder_parse(struct binder_state *bs, struct binder_io *bio,
uint32_t *ptr, uint32_t size, binder_handler func)
{
int r = 1;
uint32_t *end = ptr + (size / 4);
while (ptr < end) {
uint32_t cmd = *ptr++;
#if TRACE
fprintf(stderr,"%s:\n", cmd_name(cmd));
#endif
switch(cmd) {
case BR_NOOP:
break;
case BR_TRANSACTION_COMPLETE:
break;
case BR_INCREFS:
case BR_ACQUIRE:
case BR_RELEASE:
case BR_DECREFS:
#if TRACE
fprintf(stderr," %08x %08x\n", ptr[0], ptr[1]);
#endif
ptr += 2;
break;
case BR_TRANSACTION: {
struct binder_txn *txn = (void *) ptr;
if ((end - ptr) * sizeof(uint32_t) < sizeof(struct binder_txn)) {
ALOGE("parse: txn too small!\n");
return -1;
}
binder_dump_txn(txn);
if (func) {
unsigned rdata[256/4];
struct binder_io msg;
struct binder_io reply;
int res;
bio_init(&reply, rdata, sizeof(rdata), 4);
bio_init_from_txn(&msg, txn);
res = func(bs, txn, &msg, &reply);
binder_send_reply(bs, &reply, txn->data, res);
}
ptr += sizeof(*txn) / sizeof(uint32_t);
break;
}
case BR_REPLY: {
struct binder_txn *txn = (void*) ptr;
if ((end - ptr) * sizeof(uint32_t) < sizeof(struct binder_txn)) {
ALOGE("parse: reply too small!\n");
return -1;
}
binder_dump_txn(txn);
if (bio) {
bio_init_from_txn(bio, txn);
bio = 0;
} else {
/* todo FREE BUFFER */
}
ptr += (sizeof(*txn) / sizeof(uint32_t));
r = 0;
break;
}
case BR_DEAD_BINDER: {
struct binder_death *death = (void*) *ptr++;
death->func(bs, death->ptr);
break;
}
case BR_FAILED_REPLY:
r = -1;
break;
case BR_DEAD_REPLY:
r = -1;
break;
default:
ALOGE("parse: OOPS %d\n", cmd);
return -1;
}
}
return r;
}
void binder_acquire(struct binder_state *bs, void *ptr)
{
uint32_t cmd[2];
cmd[0] = BC_ACQUIRE;
cmd[1] = (uint32_t) ptr;
binder_write(bs, cmd, sizeof(cmd));
}
void binder_release(struct binder_state *bs, void *ptr)
{
uint32_t cmd[2];
cmd[0] = BC_RELEASE;
cmd[1] = (uint32_t) ptr;
binder_write(bs, cmd, sizeof(cmd));
}
void binder_link_to_death(struct binder_state *bs, void *ptr, struct binder_death *death)
{
uint32_t cmd[3];
cmd[0] = BC_REQUEST_DEATH_NOTIFICATION;
cmd[1] = (uint32_t) ptr;
cmd[2] = (uint32_t) death;
binder_write(bs, cmd, sizeof(cmd));
}
int binder_call(struct binder_state *bs,
struct binder_io *msg, struct binder_io *reply,
void *target, uint32_t code)
{
int res;
struct binder_write_read bwr;
struct {
uint32_t cmd;
struct binder_txn txn;
} writebuf;
unsigned readbuf[32];
if (msg->flags & BIO_F_OVERFLOW) {
fprintf(stderr,"binder: txn buffer overflow\n");
goto fail;
}
writebuf.cmd = BC_TRANSACTION;
writebuf.txn.target = target;
writebuf.txn.code = code;
writebuf.txn.flags = 0;
writebuf.txn.data_size = msg->data - msg->data0;
writebuf.txn.offs_size = ((char*) msg->offs) - ((char*) msg->offs0);
writebuf.txn.data = msg->data0;
writebuf.txn.offs = msg->offs0;
bwr.write_size = sizeof(writebuf);
bwr.write_consumed = 0;
bwr.write_buffer = (unsigned) &writebuf;
hexdump(msg->data0, msg->data - msg->data0);
for (;;) {
bwr.read_size = sizeof(readbuf);
bwr.read_consumed = 0;
bwr.read_buffer = (unsigned) readbuf;
res = ioctl(bs->fd, BINDER_WRITE_READ, &bwr);
if (res < 0) {
fprintf(stderr,"binder: ioctl failed (%s)\n", strerror(errno));
goto fail;
}
res = binder_parse(bs, reply, readbuf, bwr.read_consumed, 0);
if (res == 0) return 0;
if (res < 0) goto fail;
}
fail:
memset(reply, 0, sizeof(*reply));
reply->flags |= BIO_F_IOERROR;
return -1;
}
void binder_loop(struct binder_state *bs, binder_handler func)
{
int res;
struct binder_write_read bwr;
unsigned readbuf[32];
bwr.write_size = 0;
bwr.write_consumed = 0;
bwr.write_buffer = 0;
readbuf[0] = BC_ENTER_LOOPER;
binder_write(bs, readbuf, sizeof(unsigned));
for (;;) {
bwr.read_size = sizeof(readbuf);
bwr.read_consumed = 0;
bwr.read_buffer = (unsigned) readbuf;
res = ioctl(bs->fd, BINDER_WRITE_READ, &bwr);
if (res < 0) {
ALOGE("binder_loop: ioctl failed (%s)\n", strerror(errno));
break;
}
res = binder_parse(bs, 0, readbuf, bwr.read_consumed, func);
if (res == 0) {
ALOGE("binder_loop: unexpected reply?!\n");
break;
}
if (res < 0) {
ALOGE("binder_loop: io error %d %s\n", res, strerror(errno));
break;
}
}
}
void bio_init_from_txn(struct binder_io *bio, struct binder_txn *txn)
{
bio->data = bio->data0 = txn->data;
bio->offs = bio->offs0 = txn->offs;
bio->data_avail = txn->data_size;
bio->offs_avail = txn->offs_size / 4;
bio->flags = BIO_F_SHARED;
}
void bio_init(struct binder_io *bio, void *data,
uint32_t maxdata, uint32_t maxoffs)
{
uint32_t n = maxoffs * sizeof(uint32_t);
if (n > maxdata) {
bio->flags = BIO_F_OVERFLOW;
bio->data_avail = 0;
bio->offs_avail = 0;
return;
}
bio->data = bio->data0 = (char *) data + n;
bio->offs = bio->offs0 = data;
bio->data_avail = maxdata - n;
bio->offs_avail = maxoffs;
bio->flags = 0;
}
static void *bio_alloc(struct binder_io *bio, uint32_t size)
{
size = (size + 3) & (~3);
if (size > bio->data_avail) {
bio->flags |= BIO_F_OVERFLOW;
return 0;
} else {
void *ptr = bio->data;
bio->data += size;
bio->data_avail -= size;
return ptr;
}
}
void binder_done(struct binder_state *bs,
struct binder_io *msg,
struct binder_io *reply)
{
if (reply->flags & BIO_F_SHARED) {
uint32_t cmd[2];
cmd[0] = BC_FREE_BUFFER;
cmd[1] = (uint32_t) reply->data0;
binder_write(bs, cmd, sizeof(cmd));
reply->flags = 0;
}
}
static struct binder_object *bio_alloc_obj(struct binder_io *bio)
{
struct binder_object *obj;
obj = bio_alloc(bio, sizeof(*obj));
if (obj && bio->offs_avail) {
bio->offs_avail--;
*bio->offs++ = ((char*) obj) - ((char*) bio->data0);
return obj;
}
bio->flags |= BIO_F_OVERFLOW;
return 0;
}
void bio_put_uint32(struct binder_io *bio, uint32_t n)
{
uint32_t *ptr = bio_alloc(bio, sizeof(n));
if (ptr)
*ptr = n;
}
void bio_put_obj(struct binder_io *bio, void *ptr)
{
struct binder_object *obj;
obj = bio_alloc_obj(bio);
if (!obj)
return;
obj->flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
obj->type = BINDER_TYPE_BINDER;
obj->pointer = ptr;
obj->cookie = 0;
}
void bio_put_ref(struct binder_io *bio, void *ptr)
{
struct binder_object *obj;
if (ptr)
obj = bio_alloc_obj(bio);
else
obj = bio_alloc(bio, sizeof(*obj));
if (!obj)
return;
obj->flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
obj->type = BINDER_TYPE_HANDLE;
obj->pointer = ptr;
obj->cookie = 0;
}
void bio_put_string16(struct binder_io *bio, const uint16_t *str)
{
uint32_t len;
uint16_t *ptr;
if (!str) {
bio_put_uint32(bio, 0xffffffff);
return;
}
len = 0;
while (str[len]) len++;
if (len >= (MAX_BIO_SIZE / sizeof(uint16_t))) {
bio_put_uint32(bio, 0xffffffff);
return;
}
bio_put_uint32(bio, len);
len = (len + 1) * sizeof(uint16_t);
ptr = bio_alloc(bio, len);
if (ptr)
memcpy(ptr, str, len);
}
void bio_put_string16_x(struct binder_io *bio, const char *_str)
{
unsigned char *str = (unsigned char*) _str;
uint32_t len;
uint16_t *ptr;
if (!str) {
bio_put_uint32(bio, 0xffffffff);
return;
}
len = strlen(_str);
if (len >= (MAX_BIO_SIZE / sizeof(uint16_t))) {
bio_put_uint32(bio, 0xffffffff);
return;
}
bio_put_uint32(bio, len);
ptr = bio_alloc(bio, (len + 1) * sizeof(uint16_t));
if (!ptr)
return;
while (*str)
*ptr++ = *str++;
*ptr++ = 0;
}
static void *bio_get(struct binder_io *bio, uint32_t size)
{
size = (size + 3) & (~3);
if (bio->data_avail < size){
bio->data_avail = 0;
bio->flags |= BIO_F_OVERFLOW;
return 0;
} else {
void *ptr = bio->data;
bio->data += size;
bio->data_avail -= size;
return ptr;
}
}
uint32_t bio_get_uint32(struct binder_io *bio)
{
uint32_t *ptr = bio_get(bio, sizeof(*ptr));
return ptr ? *ptr : 0;
}
uint16_t *bio_get_string16(struct binder_io *bio, unsigned *sz)
{
unsigned len;
len = bio_get_uint32(bio);
if (sz)
*sz = len;
return bio_get(bio, (len + 1) * sizeof(uint16_t));
}
static struct binder_object *_bio_get_obj(struct binder_io *bio)
{
unsigned n;
unsigned off = bio->data - bio->data0;
/* TODO: be smarter about this? */
for (n = 0; n < bio->offs_avail; n++) {
if (bio->offs[n] == off)
return bio_get(bio, sizeof(struct binder_object));
}
bio->data_avail = 0;
bio->flags |= BIO_F_OVERFLOW;
return 0;
}
void *bio_get_ref(struct binder_io *bio)
{
struct binder_object *obj;
obj = _bio_get_obj(bio);
if (!obj)
return 0;
if (obj->type == BINDER_TYPE_HANDLE)
return obj->pointer;
return 0;
}
IPCThreadState.cpp
/*
* Copyright (C) 2005 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
*
* b0cK9s2c8@1M7q4)9K6b7g2)9J5c8W2)9J5c8Y4N6%4N6#2)9J5k6h3q4H3j5h3y4Z5k6g2)9J5k6h3!0J5k6#2)9J5c8X3I4A6j5$3g2F1M7$3g2K6i4K6u0r3e0p5W2o6c8f1&6e0c8g2)9J5k6o6u0Q4x3X3f1H3
*
* 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.
*/
#define LOG_TAG "IPCThreadState"
#include <binder/IPCThreadState.h>
#include <binder/Binder.h>
#include <binder/BpBinder.h>
#include <binder/TextOutput.h>
#include <cutils/sched_policy.h>
#include <utils/Debug.h>
#include <utils/Log.h>
#include <utils/threads.h>
#include <private/binder/binder_module.h>
#include <private/binder/Static.h>
#include <sys/ioctl.h>
#include <signal.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#ifdef HAVE_PTHREADS
#include <pthread.h>
#include <sched.h>
#include <sys/resource.h>
#endif
#ifdef HAVE_WIN32_THREADS
#include <windows.h>
#endif
#if LOG_NDEBUG
#define IF_LOG_TRANSACTIONS() if (false)
#define IF_LOG_COMMANDS() if (false)
#define LOG_REMOTEREFS(...)
#define IF_LOG_REMOTEREFS() if (false)
#define LOG_THREADPOOL(...)
#define LOG_ONEWAY(...)
#else
#define IF_LOG_TRANSACTIONS() IF_ALOG(LOG_VERBOSE, "transact")
#define IF_LOG_COMMANDS() IF_ALOG(LOG_VERBOSE, "ipc")
#define LOG_REMOTEREFS(...) ALOG(LOG_DEBUG, "remoterefs", __VA_ARGS__)
#define IF_LOG_REMOTEREFS() IF_ALOG(LOG_DEBUG, "remoterefs")
#define LOG_THREADPOOL(...) ALOG(LOG_DEBUG, "threadpool", __VA_ARGS__)
#define LOG_ONEWAY(...) ALOG(LOG_DEBUG, "ipc", __VA_ARGS__)
#endif
// ---------------------------------------------------------------------------
namespace android {
static const char* getReturnString(size_t idx);
static const char* getCommandString(size_t idx);
static const void* printReturnCommand(TextOutput& out, const void* _cmd);
static const void* printCommand(TextOutput& out, const void* _cmd);
// This will result in a missing symbol failure if the IF_LOG_COMMANDS()
// conditionals don't get stripped... but that is probably what we want.
#if !LOG_NDEBUG
static const char *kReturnStrings[] = {
"BR_ERROR",
"BR_OK",
"BR_TRANSACTION",
"BR_REPLY",
"BR_ACQUIRE_RESULT",
"BR_DEAD_REPLY",
"BR_TRANSACTION_COMPLETE",
"BR_INCREFS",
"BR_ACQUIRE",
"BR_RELEASE",
"BR_DECREFS",
"BR_ATTEMPT_ACQUIRE",
"BR_NOOP",
"BR_SPAWN_LOOPER",
"BR_FINISHED",
"BR_DEAD_BINDER",
"BR_CLEAR_DEATH_NOTIFICATION_DONE",
"BR_FAILED_REPLY"
};
static const char *kCommandStrings[] = {
"BC_TRANSACTION",
"BC_REPLY",
"BC_ACQUIRE_RESULT",
"BC_FREE_BUFFER",
"BC_INCREFS",
"BC_ACQUIRE",
"BC_RELEASE",
"BC_DECREFS",
"BC_INCREFS_DONE",
"BC_ACQUIRE_DONE",
"BC_ATTEMPT_ACQUIRE",
"BC_REGISTER_LOOPER",
"BC_ENTER_LOOPER",
"BC_EXIT_LOOPER",
"BC_REQUEST_DEATH_NOTIFICATION",
"BC_CLEAR_DEATH_NOTIFICATION",
"BC_DEAD_BINDER_DONE"
};
static const char* getReturnString(size_t idx)
{
if (idx < sizeof(kReturnStrings) / sizeof(kReturnStrings[0]))
return kReturnStrings[idx];
else
return "unknown";
}
static const char* getCommandString(size_t idx)
{
if (idx < sizeof(kCommandStrings) / sizeof(kCommandStrings[0]))
return kCommandStrings[idx];
else
return "unknown";
}
static const void* printBinderTransactionData(TextOutput& out, const void* data)
{
const binder_transaction_data* btd =
(const binder_transaction_data*)data;
if (btd->target.handle < 1024) {
/* want to print descriptors in decimal; guess based on value */
out << "target.desc=" << btd->target.handle;
} else {
out << "target.ptr=" << btd->target.ptr;
}
out << " (cookie " << btd->cookie << ")" << endl
<< "code=" << TypeCode(btd->code) << ", flags=" << (void*)btd->flags << endl
<< "data=" << btd->data.ptr.buffer << " (" << (void*)btd->data_size
<< " bytes)" << endl
<< "offsets=" << btd->data.ptr.offsets << " (" << (void*)btd->offsets_size
<< " bytes)";
return btd+1;
}
static const void* printReturnCommand(TextOutput& out, const void* _cmd)
{
static const size_t N = sizeof(kReturnStrings)/sizeof(kReturnStrings[0]);
const int32_t* cmd = (const int32_t*)_cmd;
int32_t code = *cmd++;
size_t cmdIndex = code & 0xff;
if (code == (int32_t) BR_ERROR) {
out << "BR_ERROR: " << (void*)(*cmd++) << endl;
return cmd;
} else if (cmdIndex >= N) {
out << "Unknown reply: " << code << endl;
return cmd;
}
out << kReturnStrings[cmdIndex];
switch (code) {
case BR_TRANSACTION:
case BR_REPLY: {
out << ": " << indent;
cmd = (const int32_t *)printBinderTransactionData(out, cmd);
out << dedent;
} break;
case BR_ACQUIRE_RESULT: {
const int32_t res = *cmd++;
out << ": " << res << (res ? " (SUCCESS)" : " (FAILURE)");
} break;
case BR_INCREFS:
case BR_ACQUIRE:
case BR_RELEASE:
case BR_DECREFS: {
const int32_t b = *cmd++;
const int32_t c = *cmd++;
out << ": target=" << (void*)b << " (cookie " << (void*)c << ")";
} break;
case BR_ATTEMPT_ACQUIRE: {
const int32_t p = *cmd++;
const int32_t b = *cmd++;
const int32_t c = *cmd++;
out << ": target=" << (void*)b << " (cookie " << (void*)c
<< "), pri=" << p;
} break;
case BR_DEAD_BINDER:
case BR_CLEAR_DEATH_NOTIFICATION_DONE: {
const int32_t c = *cmd++;
out << ": death cookie " << (void*)c;
} break;
default:
// no details to show for: BR_OK, BR_DEAD_REPLY,
// BR_TRANSACTION_COMPLETE, BR_FINISHED
break;
}
out << endl;
return cmd;
}
static const void* printCommand(TextOutput& out, const void* _cmd)
{
static const size_t N = sizeof(kCommandStrings)/sizeof(kCommandStrings[0]);
const int32_t* cmd = (const int32_t*)_cmd;
int32_t code = *cmd++;
size_t cmdIndex = code & 0xff;
if (cmdIndex >= N) {
out << "Unknown command: " << code << endl;
return cmd;
}
out << kCommandStrings[cmdIndex];
switch (code) {
case BC_TRANSACTION:
case BC_REPLY: {
out << ": " << indent;
cmd = (const int32_t *)printBinderTransactionData(out, cmd);
out << dedent;
} break;
case BC_ACQUIRE_RESULT: {
const int32_t res = *cmd++;
out << ": " << res << (res ? " (SUCCESS)" : " (FAILURE)");
} break;
case BC_FREE_BUFFER: {
const int32_t buf = *cmd++;
out << ": buffer=" << (void*)buf;
} break;
case BC_INCREFS:
case BC_ACQUIRE:
case BC_RELEASE:
case BC_DECREFS: {
const int32_t d = *cmd++;
out << ": desc=" << d;
} break;
case BC_INCREFS_DONE:
case BC_ACQUIRE_DONE: {
const int32_t b = *cmd++;
const int32_t c = *cmd++;
out << ": target=" << (void*)b << " (cookie " << (void*)c << ")";
} break;
case BC_ATTEMPT_ACQUIRE: {
const int32_t p = *cmd++;
const int32_t d = *cmd++;
out << ": desc=" << d << ", pri=" << p;
} break;
case BC_REQUEST_DEATH_NOTIFICATION:
case BC_CLEAR_DEATH_NOTIFICATION: {
const int32_t h = *cmd++;
const int32_t c = *cmd++;
out << ": handle=" << h << " (death cookie " << (void*)c << ")";
} break;
case BC_DEAD_BINDER_DONE: {
const int32_t c = *cmd++;
out << ": death cookie " << (void*)c;
} break;
default:
// no details to show for: BC_REGISTER_LOOPER, BC_ENTER_LOOPER,
// BC_EXIT_LOOPER
break;
}
out << endl;
return cmd;
}
#endif
static pthread_mutex_t gTLSMutex = PTHREAD_MUTEX_INITIALIZER;
static bool gHaveTLS = false;
static pthread_key_t gTLS = 0;
static bool gShutdown = false;
static bool gDisableBackgroundScheduling = false;
IPCThreadState* IPCThreadState::self()
{
if (gHaveTLS) {
restart:
const pthread_key_t k = gTLS;
IPCThreadState* st = (IPCThreadState*)pthread_getspecific(k);
if (st) return st;
return new IPCThreadState;
}
if (gShutdown) return NULL;
pthread_mutex_lock(&gTLSMutex);
if (!gHaveTLS) {
if (pthread_key_create(&gTLS, threadDestructor) != 0) {
pthread_mutex_unlock(&gTLSMutex);
return NULL;
}
gHaveTLS = true;
}
pthread_mutex_unlock(&gTLSMutex);
goto restart;
}
IPCThreadState* IPCThreadState::selfOrNull()
{
if (gHaveTLS) {
const pthread_key_t k = gTLS;
IPCThreadState* st = (IPCThreadState*)pthread_getspecific(k);
return st;
}
return NULL;
}
void IPCThreadState::shutdown()
{
gShutdown = true;
if (gHaveTLS) {
// XXX Need to wait for all thread pool threads to exit!
IPCThreadState* st = (IPCThreadState*)pthread_getspecific(gTLS);
if (st) {
delete st;
pthread_setspecific(gTLS, NULL);
}
gHaveTLS = false;
}
}
void IPCThreadState::disableBackgroundScheduling(bool disable)
{
gDisableBackgroundScheduling = disable;
}
sp<ProcessState> IPCThreadState::process()
{
return mProcess;
}
status_t IPCThreadState::clearLastError()
{
const status_t err = mLastError;
mLastError = NO_ERROR;
return err;
}
int IPCThreadState::getCallingPid() const
{
return mCallingPid;
}
int IPCThreadState::getCallingUid() const
{
return mCallingUid;
}
int64_t IPCThreadState::clearCallingIdentity()
{
int64_t token = ((int64_t)mCallingUid<<32) | mCallingPid;
clearCaller();
return token;
}
void IPCThreadState::setStrictModePolicy(int32_t policy)
{
mStrictModePolicy = policy;
}
int32_t IPCThreadState::getStrictModePolicy() const
{
return mStrictModePolicy;
}
void IPCThreadState::setLastTransactionBinderFlags(int32_t flags)
{
mLastTransactionBinderFlags = flags;
}
int32_t IPCThreadState::getLastTransactionBinderFlags() const
{
return mLastTransactionBinderFlags;
}
void IPCThreadState::restoreCallingIdentity(int64_t token)
{
mCallingUid = (int)(token>>32);
mCallingPid = (int)token;
}
void IPCThreadState::clearCaller()
{
mCallingPid = getpid();
mCallingUid = getuid();
}
void IPCThreadState::flushCommands()
{
if (mProcess->mDriverFD <= 0)
return;
talkWithDriver(false);
}
status_t IPCThreadState::getAndExecuteCommand()
{
status_t result;
int32_t cmd;
result = talkWithDriver();
if (result >= NO_ERROR) {
size_t IN = mIn.dataAvail();
if (IN < sizeof(int32_t)) return result;
cmd = mIn.readInt32();
IF_LOG_COMMANDS() {
alog << "Processing top-level Command: "
<< getReturnString(cmd) << endl;
}
result = executeCommand(cmd);
// After executing the command, ensure that the thread is returned to the
// foreground cgroup before rejoining the pool. The driver takes care of
// restoring the priority, but doesn't do anything with cgroups so we
// need to take care of that here in userspace. Note that we do make
// sure to go in the foreground after executing a transaction, but
// there are other callbacks into user code that could have changed
// our group so we want to make absolutely sure it is put back.
set_sched_policy(mMyThreadId, SP_FOREGROUND);
}
return result;
}
// When we've cleared the incoming command queue, process any pending derefs
void IPCThreadState::processPendingDerefs()
{
if (mIn.dataPosition() >= mIn.dataSize()) {
size_t numPending = mPendingWeakDerefs.size();
if (numPending > 0) {
for (size_t i = 0; i < numPending; i++) {
RefBase::weakref_type* refs = mPendingWeakDerefs[i];
refs->decWeak(mProcess.get());
}
mPendingWeakDerefs.clear();
}
numPending = mPendingStrongDerefs.size();
if (numPending > 0) {
for (size_t i = 0; i < numPending; i++) {
BBinder* obj = mPendingStrongDerefs[i];
obj->decStrong(mProcess.get());
}
mPendingStrongDerefs.clear();
}
}
}
void IPCThreadState::joinThreadPool(bool isMain)
{
LOG_THREADPOOL("**** THREAD %p (PID %d) IS JOINING THE THREAD POOL\n", (void*)pthread_self(), getpid());
mOut.writeInt32(isMain ? BC_ENTER_LOOPER : BC_REGISTER_LOOPER);
// This thread may have been spawned by a thread that was in the background
// scheduling group, so first we will make sure it is in the foreground
// one to avoid performing an initial transaction in the background.
set_sched_policy(mMyThreadId, SP_FOREGROUND);
status_t result;
do {
processPendingDerefs();
// now get the next command to be processed, waiting if necessary
result = getAndExecuteCommand();
if (result < NO_ERROR && result != TIMED_OUT && result != -ECONNREFUSED && result != -EBADF) {
ALOGE("getAndExecuteCommand(fd=%d) returned unexpected error %d, aborting",
mProcess->mDriverFD, result);
abort();
}
// Let this thread exit the thread pool if it is no longer
// needed and it is not the main process thread.
if(result == TIMED_OUT && !isMain) {
break;
}
} while (result != -ECONNREFUSED && result != -EBADF);
LOG_THREADPOOL("**** THREAD %p (PID %d) IS LEAVING THE THREAD POOL err=%p\n",
(void*)pthread_self(), getpid(), (void*)result);
mOut.writeInt32(BC_EXIT_LOOPER);
talkWithDriver(false);
}
int IPCThreadState::setupPolling(int* fd)
{
if (mProcess->mDriverFD <= 0) {
return -EBADF;
}
mOut.writeInt32(BC_ENTER_LOOPER);
*fd = mProcess->mDriverFD;
return 0;
}
status_t IPCThreadState::handlePolledCommands()
{
status_t result;
do {
result = getAndExecuteCommand();
} while (mIn.dataPosition() < mIn.dataSize());
processPendingDerefs();
flushCommands();
return result;
}
void IPCThreadState::stopProcess(bool immediate)
{
//ALOGI("**** STOPPING PROCESS");
flushCommands();
int fd = mProcess->mDriverFD;
mProcess->mDriverFD = -1;
close(fd);
//kill(getpid(), SIGKILL);
}
status_t IPCThreadState::transact(int32_t handle,
uint32_t code, const Parcel& data,
Parcel* reply, uint32_t flags)
{
status_t err = data.errorCheck();
flags |= TF_ACCEPT_FDS;
IF_LOG_TRANSACTIONS() {
TextOutput::Bundle _b(alog);
alog << "BC_TRANSACTION thr " << (void*)pthread_self() << " / hand "
<< handle << " / code " << TypeCode(code) << ": "
<< indent << data << dedent << endl;
}
if (err == NO_ERROR) {
LOG_ONEWAY(">>>> SEND from pid %d uid %d %s", getpid(), getuid(),
(flags & TF_ONE_WAY) == 0 ? "READ REPLY" : "ONE WAY");
err = writeTransactionData(BC_TRANSACTION, flags, handle, code, data, NULL);
}
if (err != NO_ERROR) {
if (reply) reply->setError(err);
return (mLastError = err);
}
if ((flags & TF_ONE_WAY) == 0) {
#if 0
if (code == 4) { // relayout
ALOGI(">>>>>> CALLING transaction 4");
} else {
ALOGI(">>>>>> CALLING transaction %d", code);
}
#endif
if (reply) {
err = waitForResponse(reply);
} else {
Parcel fakeReply;
err = waitForResponse(&fakeReply);
}
#if 0
if (code == 4) { // relayout
ALOGI("<<<<<< RETURNING transaction 4");
} else {
ALOGI("<<<<<< RETURNING transaction %d", code);
}
#endif
IF_LOG_TRANSACTIONS() {
TextOutput::Bundle _b(alog);
alog << "BR_REPLY thr " << (void*)pthread_self() << " / hand "
<< handle << ": ";
if (reply) alog << indent << *reply << dedent << endl;
else alog << "(none requested)" << endl;
}
} else {
err = waitForResponse(NULL, NULL);
}
return err;
}
void IPCThreadState::incStrongHandle(int32_t handle)
{
LOG_REMOTEREFS("IPCThreadState::incStrongHandle(%d)\n", handle);
mOut.writeInt32(BC_ACQUIRE);
mOut.writeInt32(handle);
}
void IPCThreadState::decStrongHandle(int32_t handle)
{
LOG_REMOTEREFS("IPCThreadState::decStrongHandle(%d)\n", handle);
mOut.writeInt32(BC_RELEASE);
mOut.writeInt32(handle);
}
void IPCThreadState::incWeakHandle(int32_t handle)
{
LOG_REMOTEREFS("IPCThreadState::incWeakHandle(%d)\n", handle);
mOut.writeInt32(BC_INCREFS);
mOut.writeInt32(handle);
}
void IPCThreadState::decWeakHandle(int32_t handle)
{
LOG_REMOTEREFS("IPCThreadState::decWeakHandle(%d)\n", handle);
mOut.writeInt32(BC_DECREFS);
mOut.writeInt32(handle);
}
status_t IPCThreadState::attemptIncStrongHandle(int32_t handle)
{
LOG_REMOTEREFS("IPCThreadState::attemptIncStrongHandle(%d)\n", handle);
mOut.writeInt32(BC_ATTEMPT_ACQUIRE);
mOut.writeInt32(0); // xxx was thread priority
mOut.writeInt32(handle);
status_t result = UNKNOWN_ERROR;
waitForResponse(NULL, &result);
#if LOG_REFCOUNTS
printf("IPCThreadState::attemptIncStrongHandle(%ld) = %s\n",
handle, result == NO_ERROR ? "SUCCESS" : "FAILURE");
#endif
return result;
}
void IPCThreadState::expungeHandle(int32_t handle, IBinder* binder)
{
#if LOG_REFCOUNTS
printf("IPCThreadState::expungeHandle(%ld)\n", handle);
#endif
self()->mProcess->expungeHandle(handle, binder);
}
status_t IPCThreadState::requestDeathNotification(int32_t handle, BpBinder* proxy)
{
mOut.writeInt32(BC_REQUEST_DEATH_NOTIFICATION);
mOut.writeInt32((int32_t)handle);
mOut.writeInt32((int32_t)proxy);
return NO_ERROR;
}
status_t IPCThreadState::clearDeathNotification(int32_t handle, BpBinder* proxy)
{
mOut.writeInt32(BC_CLEAR_DEATH_NOTIFICATION);
mOut.writeInt32((int32_t)handle);
mOut.writeInt32((int32_t)proxy);
return NO_ERROR;
}
IPCThreadState::IPCThreadState()
: mProcess(ProcessState::self()),
mMyThreadId(androidGetTid()),
mStrictModePolicy(0),
mLastTransactionBinderFlags(0)
{
pthread_setspecific(gTLS, this);
clearCaller();
mIn.setDataCapacity(256);
mOut.setDataCapacity(256);
}
IPCThreadState::~IPCThreadState()
{
}
status_t IPCThreadState::sendReply(const Parcel& reply, uint32_t flags)
{
status_t err;
status_t statusBuffer;
err = writeTransactionData(BC_REPLY, flags, -1, 0, reply, &statusBuffer);
if (err < NO_ERROR) return err;
return waitForResponse(NULL, NULL);
}
status_t IPCThreadState::waitForResponse(Parcel *reply, status_t *acquireResult)
{
int32_t cmd;
int32_t err;
while (1) {
if ((err=talkWithDriver()) < NO_ERROR) break;
err = mIn.errorCheck();
if (err < NO_ERROR) break;
if (mIn.dataAvail() == 0) continue;
cmd = mIn.readInt32();
IF_LOG_COMMANDS() {
alog << "Processing waitForResponse Command: "
<< getReturnString(cmd) << endl;
}
switch (cmd) {
case BR_TRANSACTION_COMPLETE:
if (!reply && !acquireResult) goto finish;
break;
case BR_DEAD_REPLY:
err = DEAD_OBJECT;
goto finish;
case BR_FAILED_REPLY:
err = FAILED_TRANSACTION;
goto finish;
case BR_ACQUIRE_RESULT:
{
ALOG_ASSERT(acquireResult != NULL, "Unexpected brACQUIRE_RESULT");
const int32_t result = mIn.readInt32();
if (!acquireResult) continue;
*acquireResult = result ? NO_ERROR : INVALID_OPERATION;
}
goto finish;
case BR_REPLY:
{
binder_transaction_data tr;
err = mIn.read(&tr, sizeof(tr));
ALOG_ASSERT(err == NO_ERROR, "Not enough command data for brREPLY");
if (err != NO_ERROR) goto finish;
if (reply) {
if ((tr.flags & TF_STATUS_CODE) == 0) {
reply->ipcSetDataReference(
reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
tr.data_size,
reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
tr.offsets_size/sizeof(size_t),
freeBuffer, this);
} else {
err = *static_cast<const status_t*>(tr.data.ptr.buffer);
freeBuffer(NULL,
reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
tr.data_size,
reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
tr.offsets_size/sizeof(size_t), this);
}
} else {
freeBuffer(NULL,
reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
tr.data_size,
reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
tr.offsets_size/sizeof(size_t), this);
continue;
}
}
goto finish;
default:
err = executeCommand(cmd);
if (err != NO_ERROR) goto finish;
break;
}
}
finish:
if (err != NO_ERROR) {
if (acquireResult) *acquireResult = err;
if (reply) reply->setError(err);
mLastError = err;
}
return err;
}
status_t IPCThreadState::talkWithDriver(bool doReceive)
{
if (mProcess->mDriverFD <= 0) {
return -EBADF;
}
binder_write_read bwr;
// Is the read buffer empty?
const bool needRead = mIn.dataPosition() >= mIn.dataSize();
// We don't want to write anything if we are still reading
// from data left in the input buffer and the caller
// has requested to read the next data.
const size_t outAvail = (!doReceive || needRead) ? mOut.dataSize() : 0;
bwr.write_size = outAvail;
bwr.write_buffer = (long unsigned int)mOut.data();
// This is what we'll read.
if (doReceive && needRead) {
bwr.read_size = mIn.dataCapacity();
bwr.read_buffer = (long unsigned int)mIn.data();
} else {
bwr.read_size = 0;
bwr.read_buffer = 0;
}
IF_LOG_COMMANDS() {
TextOutput::Bundle _b(alog);
if (outAvail != 0) {
alog << "Sending commands to driver: " << indent;
const void* cmds = (const void*)bwr.write_buffer;
const void* end = ((const uint8_t*)cmds)+bwr.write_size;
alog << HexDump(cmds, bwr.write_size) << endl;
while (cmds < end) cmds = printCommand(alog, cmds);
alog << dedent;
}
alog << "Size of receive buffer: " << bwr.read_size
<< ", needRead: " << needRead << ", doReceive: " << doReceive << endl;
}
// Return immediately if there is nothing to do.
if ((bwr.write_size == 0) && (bwr.read_size == 0)) return NO_ERROR;
bwr.write_consumed = 0;
bwr.read_consumed = 0;
status_t err;
do {
IF_LOG_COMMANDS() {
alog << "About to read/write, write size = " << mOut.dataSize() << endl;
}
#if defined(HAVE_ANDROID_OS)
if (ioctl(mProcess->mDriverFD, BINDER_WRITE_READ, &bwr) >= 0)
err = NO_ERROR;
else
err = -errno;
#else
err = INVALID_OPERATION;
#endif
if (mProcess->mDriverFD <= 0) {
err = -EBADF;
}
IF_LOG_COMMANDS() {
alog << "Finished read/write, write size = " << mOut.dataSize() << endl;
}
} while (err == -EINTR);
IF_LOG_COMMANDS() {
alog << "Our err: " << (void*)err << ", write consumed: "
<< bwr.write_consumed << " (of " << mOut.dataSize()
<< "), read consumed: " << bwr.read_consumed << endl;
}
if (err >= NO_ERROR) {
if (bwr.write_consumed > 0) {
if (bwr.write_consumed < (ssize_t)mOut.dataSize())
mOut.remove(0, bwr.write_consumed);
else
mOut.setDataSize(0);
}
if (bwr.read_consumed > 0) {
mIn.setDataSize(bwr.read_consumed);
mIn.setDataPosition(0);
}
IF_LOG_COMMANDS() {
TextOutput::Bundle _b(alog);
alog << "Remaining data size: " << mOut.dataSize() << endl;
alog << "Received commands from driver: " << indent;
const void* cmds = mIn.data();
const void* end = mIn.data() + mIn.dataSize();
alog << HexDump(cmds, mIn.dataSize()) << endl;
while (cmds < end) cmds = printReturnCommand(alog, cmds);
alog << dedent;
}
return NO_ERROR;
}
return err;
}
status_t IPCThreadState::writeTransactionData(int32_t cmd, uint32_t binderFlags,
int32_t handle, uint32_t code, const Parcel& data, status_t* statusBuffer)
{
binder_transaction_data tr;
tr.target.handle = handle;
tr.code = code;
tr.flags = binderFlags;
tr.cookie = 0;
tr.sender_pid = 0;
tr.sender_euid = 0;
const status_t err = data.errorCheck();
if (err == NO_ERROR) {
tr.data_size = data.ipcDataSize();
tr.data.ptr.buffer = data.ipcData();
tr.offsets_size = data.ipcObjectsCount()*sizeof(size_t);
tr.data.ptr.offsets = data.ipcObjects();
} else if (statusBuffer) {
tr.flags |= TF_STATUS_CODE;
*statusBuffer = err;
tr.data_size = sizeof(status_t);
tr.data.ptr.buffer = statusBuffer;
tr.offsets_size = 0;
tr.data.ptr.offsets = NULL;
} else {
return (mLastError = err);
}
mOut.writeInt32(cmd);
mOut.write(&tr, sizeof(tr));
return NO_ERROR;
}
sp<BBinder> the_context_object;
void setTheContextObject(sp<BBinder> obj)
{
the_context_object = obj;
}
status_t IPCThreadState::executeCommand(int32_t cmd)
{
BBinder* obj;
RefBase::weakref_type* refs;
status_t result = NO_ERROR;
switch (cmd) {
case BR_ERROR:
result = mIn.readInt32();
break;
case BR_OK:
break;
case BR_ACQUIRE:
refs = (RefBase::weakref_type*)mIn.readInt32();
obj = (BBinder*)mIn.readInt32();
ALOG_ASSERT(refs->refBase() == obj,
"BR_ACQUIRE: object %p does not match cookie %p (expected %p)",
refs, obj, refs->refBase());
obj->incStrong(mProcess.get());
IF_LOG_REMOTEREFS() {
LOG_REMOTEREFS("BR_ACQUIRE from driver on %p", obj);
obj->printRefs();
}
mOut.writeInt32(BC_ACQUIRE_DONE);
mOut.writeInt32((int32_t)refs);
mOut.writeInt32((int32_t)obj);
break;
case BR_RELEASE:
refs = (RefBase::weakref_type*)mIn.readInt32();
obj = (BBinder*)mIn.readInt32();
ALOG_ASSERT(refs->refBase() == obj,
"BR_RELEASE: object %p does not match cookie %p (expected %p)",
refs, obj, refs->refBase());
IF_LOG_REMOTEREFS() {
LOG_REMOTEREFS("BR_RELEASE from driver on %p", obj);
obj->printRefs();
}
mPendingStrongDerefs.push(obj);
break;
case BR_INCREFS:
refs = (RefBase::weakref_type*)mIn.readInt32();
obj = (BBinder*)mIn.readInt32();
refs->incWeak(mProcess.get());
mOut.writeInt32(BC_INCREFS_DONE);
mOut.writeInt32((int32_t)refs);
mOut.writeInt32((int32_t)obj);
break;
case BR_DECREFS:
refs = (RefBase::weakref_type*)mIn.readInt32();
obj = (BBinder*)mIn.readInt32();
// NOTE: This assertion is not valid, because the object may no
// longer exist (thus the (BBinder*)cast above resulting in a different
// memory address).
//ALOG_ASSERT(refs->refBase() == obj,
// "BR_DECREFS: object %p does not match cookie %p (expected %p)",
// refs, obj, refs->refBase());
mPendingWeakDerefs.push(refs);
break;
case BR_ATTEMPT_ACQUIRE:
refs = (RefBase::weakref_type*)mIn.readInt32();
obj = (BBinder*)mIn.readInt32();
{
const bool success = refs->attemptIncStrong(mProcess.get());
ALOG_ASSERT(success && refs->refBase() == obj,
"BR_ATTEMPT_ACQUIRE: object %p does not match cookie %p (expected %p)",
refs, obj, refs->refBase());
mOut.writeInt32(BC_ACQUIRE_RESULT);
mOut.writeInt32((int32_t)success);
}
break;
case BR_TRANSACTION:
{
binder_transaction_data tr;
result = mIn.read(&tr, sizeof(tr));
ALOG_ASSERT(result == NO_ERROR,
"Not enough command data for brTRANSACTION");
if (result != NO_ERROR) break;
Parcel buffer;
buffer.ipcSetDataReference(
reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer),
tr.data_size,
reinterpret_cast<const size_t*>(tr.data.ptr.offsets),
tr.offsets_size/sizeof(size_t), freeBuffer, this);
const pid_t origPid = mCallingPid;
const uid_t origUid = mCallingUid;
mCallingPid = tr.sender_pid;
mCallingUid = tr.sender_euid;
int curPrio = getpriority(PRIO_PROCESS, mMyThreadId);
if (gDisableBackgroundScheduling) {
if (curPrio > ANDROID_PRIORITY_NORMAL) {
// We have inherited a reduced priority from the caller, but do not
// want to run in that state in this process. The driver set our
// priority already (though not our scheduling class), so bounce
// it back to the default before invoking the transaction.
setpriority(PRIO_PROCESS, mMyThreadId, ANDROID_PRIORITY_NORMAL);
}
} else {
if (curPrio >= ANDROID_PRIORITY_BACKGROUND) {
// We want to use the inherited priority from the caller.
// Ensure this thread is in the background scheduling class,
// since the driver won't modify scheduling classes for us.
// The scheduling group is reset to default by the caller
// once this method returns after the transaction is complete.
set_sched_policy(mMyThreadId, SP_BACKGROUND);
}
}
//ALOGI(">>>> TRANSACT from pid %d uid %d\n", mCallingPid, mCallingUid);
Parcel reply;
IF_LOG_TRANSACTIONS() {
TextOutput::Bundle _b(alog);
alog << "BR_TRANSACTION thr " << (void*)pthread_self()
<< " / obj " << tr.target.ptr << " / code "
<< TypeCode(tr.code) << ": " << indent << buffer
<< dedent << endl
<< "Data addr = "
<< reinterpret_cast<const uint8_t*>(tr.data.ptr.buffer)
<< ", offsets addr="
<< reinterpret_cast<const size_t*>(tr.data.ptr.offsets) << endl;
}
if (tr.target.ptr) {
sp<BBinder> b((BBinder*)tr.cookie);
const status_t error = b->transact(tr.code, buffer, &reply, tr.flags);
if (error < NO_ERROR) reply.setError(error);
} else {
const status_t error = the_context_object->transact(tr.code, buffer, &reply, tr.flags);
if (error < NO_ERROR) reply.setError(error);
}
//ALOGI("<<<< TRANSACT from pid %d restore pid %d uid %d\n",
// mCallingPid, origPid, origUid);
if ((tr.flags & TF_ONE_WAY) == 0) {
LOG_ONEWAY("Sending reply to %d!", mCallingPid);
sendReply(reply, 0);
} else {
LOG_ONEWAY("NOT sending reply to %d!", mCallingPid);
}
mCallingPid = origPid;
mCallingUid = origUid;
IF_LOG_TRANSACTIONS() {
TextOutput::Bundle _b(alog);
alog << "BC_REPLY thr " << (void*)pthread_self() << " / obj "
<< tr.target.ptr << ": " << indent << reply << dedent << endl;
}
}
break;
case BR_DEAD_BINDER:
{
BpBinder *proxy = (BpBinder*)mIn.readInt32();
proxy->sendObituary();
mOut.writeInt32(BC_DEAD_BINDER_DONE);
mOut.writeInt32((int32_t)proxy);
} break;
case BR_CLEAR_DEATH_NOTIFICATION_DONE:
{
BpBinder *proxy = (BpBinder*)mIn.readInt32();
proxy->getWeakRefs()->decWeak(proxy);
} break;
case BR_FINISHED:
result = TIMED_OUT;
break;
case BR_NOOP:
break;
case BR_SPAWN_LOOPER:
mProcess->spawnPooledThread(false);
break;
default:
printf("*** BAD COMMAND %d received from Binder driver\n", cmd);
result = UNKNOWN_ERROR;
break;
}
if (result != NO_ERROR) {
mLastError = result;
}
return result;
}
void IPCThreadState::threadDestructor(void *st)
{
IPCThreadState* const self = static_cast<IPCThreadState*>(st);
if (self) {
self->flushCommands();
#if defined(HAVE_ANDROID_OS)
if (self->mProcess->mDriverFD > 0) {
ioctl(self->mProcess->mDriverFD, BINDER_THREAD_EXIT, 0);
}
#endif
delete self;
}
}
void IPCThreadState::freeBuffer(Parcel* parcel, const uint8_t* data, size_t dataSize,
const size_t* objects, size_t objectsSize,
void* cookie)
{
//ALOGI("Freeing parcel %p", &parcel);
IF_LOG_COMMANDS() {
alog << "Writing BC_FREE_BUFFER for " << data << endl;
}
ALOG_ASSERT(data != NULL, "Called with NULL data");
if (parcel != NULL) parcel->closeFileDescriptors();
IPCThreadState* state = self();
state->mOut.writeInt32(BC_FREE_BUFFER);
state->mOut.writeInt32((int32_t)data);
}
}; // namespace android
Binder的IPC通讯分为命令模式和返回模式两种,从源码中可以看出。
static const char *kReturnStrings[] = {
"BR_ERROR",
"BR_OK",
"BR_TRANSACTION",
"BR_REPLY",
"BR_ACQUIRE_RESULT",
"BR_DEAD_REPLY",
"BR_TRANSACTION_COMPLETE",
"BR_INCREFS",
"BR_ACQUIRE",
"BR_RELEASE",
"BR_DECREFS",
"BR_ATTEMPT_ACQUIRE",
"BR_NOOP",
"BR_SPAWN_LOOPER",
"BR_FINISHED",
"BR_DEAD_BINDER",
"BR_CLEAR_DEATH_NOTIFICATION_DONE",
"BR_FAILED_REPLY"
};
static const char *kCommandStrings[] = {
"BC_TRANSACTION",
"BC_REPLY",
"BC_ACQUIRE_RESULT",
"BC_FREE_BUFFER",
"BC_INCREFS",
"BC_ACQUIRE",
"BC_RELEASE",
"BC_DECREFS",
"BC_INCREFS_DONE",
"BC_ACQUIRE_DONE",
"BC_ATTEMPT_ACQUIRE",
"BC_REGISTER_LOOPER",
"BC_ENTER_LOOPER",
"BC_EXIT_LOOPER",
"BC_REQUEST_DEATH_NOTIFICATION",
"BC_CLEAR_DEATH_NOTIFICATION",
"BC_DEAD_BINDER_DONE"
};
这是一段测试代码:
void *svcmgr_lookup(struct binder_state *bs, void *target, const char *name)
{
void *ptr;
unsigned iodata[512/4];
struct binder_io msg, reply;
bio_init(&msg, iodata, sizeof(iodata), 4);
bio_put_uint32(&msg, 0); // strict mode header
bio_put_string16_x(&msg, SVC_MGR_NAME);
bio_put_string16_x(&msg, name);
if (binder_call(bs, &msg, &reply, target, SVC_MGR_CHECK_SERVICE))
return 0;
ptr = bio_get_ref(&reply);
if (ptr)
binder_acquire(bs, ptr);
binder_done(bs, &msg, &reply);
return ptr;
}
相信大家都应该了解,IPC通讯的过程了。剩下的就是如何通过hook ioctl,并通过解析binder数据包,来实现具体的拦截动作了。希望对大家有帮助。
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