* Re: [PATCH] binder: prevent transactions to context manager from its own process.
2019-07-15 19:18 [PATCH] binder: prevent transactions to context manager from its own process Hridya Valsaraju
2019-07-15 20:36 ` Todd Kjos
@ 2019-10-11 21:59 ` Jann Horn
2019-10-11 22:11 ` Jann Horn
1 sibling, 1 reply; 6+ messages in thread
From: Jann Horn @ 2019-10-11 21:59 UTC (permalink / raw)
To: Hridya Valsaraju, Todd Kjos
Cc: open list:ANDROID DRIVERS, kernel-team,
syzbot+8b3c354d33c4ac78bfad, Greg Kroah-Hartman, kernel list,
Arve Hjønnevåg, Joel Fernandes, Martijn Coenen,
Christian Brauner
[-- Attachment #1: Type: text/plain, Size: 7498 bytes --]
On Mon, Jul 15, 2019 at 9:18 PM Hridya Valsaraju <hridya@google.com> wrote:
> Currently, a transaction to context manager from its own process
> is prevented by checking if its binder_proc struct is the same as
> that of the sender. However, this would not catch cases where the
> process opens the binder device again and uses the new fd to send
> a transaction to the context manager.
>
> Reported-by: syzbot+8b3c354d33c4ac78bfad@syzkaller.appspotmail.com
> Signed-off-by: Hridya Valsaraju <hridya@google.com>
> ---
> drivers/android/binder.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index e4d25ebec5be..89b9cedae088 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3138,7 +3138,7 @@ static void binder_transaction(struct binder_proc *proc,
> else
> return_error = BR_DEAD_REPLY;
> mutex_unlock(&context->context_mgr_node_lock);
> - if (target_node && target_proc == proc) {
> + if (target_node && target_proc->pid == proc->pid) {
> binder_user_error("%d:%d got transaction to context manager from process owning it\n",
> proc->pid, thread->pid);
> return_error = BR_FAILED_REPLY;
This isn't a valid fix.
For context, the syzkaller report at
<https://lore.kernel.org/lkml/000000000000afe2c70589526668@google.com/>
triggered this WARN_ON() in binder_transaction_buffer_release() in the
BINDER_TYPE_FD case, which Todd added in 44d8047f1d87 ("binder: use
standard functions to allocate fds"):
case BINDER_TYPE_FD: {
/*
* No need to close the file here since user-space
* closes it for for successfully delivered
* transactions. For transactions that weren't
* delivered, the new fd was never allocated so
* there is no need to close and the fput on the
* file is done when the transaction is torn
* down.
*/
WARN_ON(failed_at &&
proc->tsk == current->group_leader);
} break;
That check seems to be attempting to detect cases where
binder_transaction() fails and rolls back a partial transaction sent
by a process to itself. I think the intent there is probably to catch
cases that would cause the check in the BINDER_TYPE_FDA case below to
trip up?
About this fix: This prevents a task from sending binder transactions
to the context manager if they're running in the same process. (By the
way, I don't understand why that's a problem, conceptually.) But you
can still open a binder device twice (binder_proc instances A and B)
from a process that does not own the context manager instance, pass a
binder object from A to the context manager, let the context manager
pass it to B, and then A can transact with the same-process B. So this
merely looks fixed because syzkaller isn't able to construct such a
complicated testcase. (I think you could also let A receive a handle
to itself and then transact with itself, but I haven't tested that.)
I think this fix should probably be reverted (unless you actually want
to prevent intra-process transactions, which would probably require a
bunch of ugly extra checks), the WARN_ON() should be removed, and the
BINDER_TYPE_FDA case should be adjusted to make its decision based on
a flag passed from its parent instead of guessing based on what
`current` is. Since it looks like because of this bug, an aborted
intra-process transaction containing BINDER_TYPE_FDA (e.g. via the
err_translate_failed or err_dead_proc_or_thread cases) will cause file
descriptors to unexpectedly be released in the caller, leading to a
file-descriptor use-after-free in userspace, the fix should probably
also be stable-backported. (It's probably not a huge problem in
practice though, given that only hwbinder uses BINDER_TYPE_FDA and you
need to have an intra-process transaction at the same time as
something like a thread going away, or something like that? I don't
fully understand the failure conditions for binder transactions.)
Here's a reproducer for triggering the WARN_ON() on git master. The
helper files binder.c and binder.h are attached.
=================
#define _GNU_SOURCE
#include <unistd.h>
#include <stdio.h>
#include <stdint.h>
#include <err.h>
#include <stdlib.h>
#include <sys/signal.h>
#include <sys/prctl.h>
#include "binder.h"
#define BINDER_PATH "/dev/binder/binder"
static void do_exit(int dummy) {
_exit(1);
}
static uint32_t ref_a_from_manager;
int my_handler(struct binder_state *bs, struct binder_transaction_data *txn,
struct binder_io *msg, struct binder_io *reply) {
if (txn->code == 1) {
ref_a_from_manager = bio_get_ref(msg);
if (ref_a_from_manager == 0)
errx(1, "manager received bogus message 1");
binder_acquire(bs, ref_a_from_manager);
printf("manager received handle 0x%x from A\n", ref_a_from_manager);
return 0;
} else if (txn->code == 2) {
if (ref_a_from_manager == 0)
errx(1, "B asked too early");
bio_put_ref(reply, ref_a_from_manager);
printf("manager is sending handle to B\n");
return 0;
} else {
errx(1, "manager got unexpected message");
}
}
int main(void) {
if (signal(SIGCHLD, do_exit))
err(1, "signal");
struct binder_state *bs_mgr = binder_open(BINDER_PATH, 0x400000);
if (bs_mgr == NULL)
err(1, "binder_open()");
if (binder_become_context_manager(bs_mgr))
err(1, "become mgr");
pid_t child = fork();
if (child == -1)
err(1, "fork");
if (child == 0) {
prctl(PR_SET_PDEATHSIG, SIGKILL);
if (getppid() == 1) exit(0);
/* create endpoint A and send message with handle to manager */
{
struct binder_state *bs_a = binder_open(BINDER_PATH, 0x400000);
if (bs_a == NULL) err(1, "binder_open()");
struct binder_io msg;
struct binder_io reply;
char data[0x1000];
bio_init(&msg, data, sizeof(data), 4);
bio_put_obj(&msg, (void*)1);
if (binder_call(bs_a, &msg, &reply, 0, 1/*code*/))
errx(1, "binder_call");
binder_done(bs_a, &msg, &reply);
}
/* create endpoint B and retrieve handle from manager */
struct binder_state *bs_b;
uint32_t ref_a_from_b;
{
bs_b = binder_open(BINDER_PATH, 0x400000);
if (bs_b == NULL) err(1, "binder_open()");
struct binder_io msg;
struct binder_io reply;
char data[0x1000];
bio_init(&msg, data, sizeof(data), 4);
if (binder_call(bs_b, &msg, &reply, 0, 2/*code*/))
errx(1, "binder_call");
ref_a_from_b = bio_get_ref(&reply);
if (ref_a_from_b == 0)
errx(1, "B received bogus reply");
binder_acquire(bs_b, ref_a_from_b);
printf("B received handle 0x%x from manager\n", ref_a_from_b);
binder_done(bs_b, &msg, &reply);
}
/* let B send a message with a valid FD and an invalid FD to A */
{
struct binder_io msg;
struct binder_io reply;
char data[0x1000];
bio_init(&msg, data, sizeof(data), 4);
bio_put_fd(&msg, 0); /*valid*/
bio_put_fd(&msg, -1); /*invalid*/
if (binder_call(bs_b, &msg, &reply, ref_a_from_b, 3/*code*/))
errx(1, "binder_call");
}
exit(0);
}
binder_loop(bs_mgr, my_handler);
}
=================
[-- Attachment #2: binder.h --]
[-- Type: text/x-chdr, Size: 4181 bytes --]
/* Copyright 2008 The Android Open Source Project
*/
#ifndef _BINDER_H_
#define _BINDER_H_
#include <sys/ioctl.h>
#include </h/aosp-walleye/bionic/libc/kernel/uapi/linux/android/binder.h>
struct binder_state
{
int fd;
void *mapped;
size_t mapsize;
};
struct binder_io
{
char *data; /* pointer to read/write from */
binder_size_t *offs; /* array of offsets */
size_t data_avail; /* bytes available in data buffer */
size_t offs_avail; /* entries available in offsets array */
char *data0; /* start of data buffer */
binder_size_t *offs0; /* start of offsets buffer */
uint32_t flags;
uint32_t unused;
uint64_t buffers_size;
};
struct binder_death {
void (*func)(struct binder_state *bs, void *ptr);
void *ptr;
};
/* the one magic handle */
#define BINDER_SERVICE_MANAGER 0U
#define SVC_MGR_NAME "android.os.IServiceManager"
enum {
/* Must match definitions in IBinder.h and IServiceManager.h */
PING_TRANSACTION = B_PACK_CHARS('_','P','N','G'),
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_transaction_data *txn,
struct binder_io *msg,
struct binder_io *reply);
struct binder_state *binder_open(char *device, size_t 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,
uint32_t target, uint32_t code);
int binder_call_async(struct binder_state *bs,
struct binder_io *msg,
uint32_t target, uint32_t code);
int binder_read_reply(struct binder_state* bs,
struct binder_io* reply);
int binder_read_reply_handler(struct binder_state* bs,
struct binder_io* reply, binder_handler func);
/* 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);
/* manipulate strong references */
void binder_acquire(struct binder_state *bs, uint32_t target);
void binder_release(struct binder_state *bs, uint32_t target);
void binder_increfs(struct binder_state *bs, uint32_t target);
void binder_decrefs(struct binder_state *bs, uint32_t target);
void binder_link_to_death(struct binder_state *bs, uint32_t target, 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,
size_t maxdata, size_t maxobjects);
void bio_put_obj(struct binder_io *bio, void *ptr);
void bio_put_fd(struct binder_io *bio, int fd);
void bio_put_ref(struct binder_io *bio, uint32_t handle);
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);
void bio_put_string8_x(struct binder_io *bio, const char *_str);
void bio_put_cstring(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, size_t *sz);
char *bio_get_string8(struct binder_io *bio, size_t *sz);
uint32_t bio_get_ref(struct binder_io *bio);
uint32_t bio_get_ref_cookie(struct binder_io *bio, uint64_t* cookie);
void bio_put_buf(struct binder_io *bio, void *data, size_t len, int *buf_id);
void bio_put_sub_buf(struct binder_io *bio, int parent_id, int parent_offset, void *data, size_t len, int *buf_id);
int binder_write(struct binder_state *bs, void *data, size_t len);
#endif
[-- Attachment #3: binder.c --]
[-- Type: text/x-csrc, Size: 25964 bytes --]
/* Copyright 2008 The Android Open Source Project
*/
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <err.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include "binder.h"
#define MAX_BIO_SIZE (1 << 30)
#define TRACE 0
#define LOG_TAG "Binder"
#define ALOGE(...)
#define ALOGW(...)
#define ALOGD(...)
void bio_init_from_txn(struct binder_io *io, struct binder_transaction_data *txn);
#if TRACE
void hexdump(void *_data, size_t len)
{
unsigned char *data = _data;
size_t count;
for (count = 0; count < len; count++) {
if ((count & 15) == 0)
fprintf(stderr,"%04zu:", 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_transaction_data *txn)
{
struct flat_binder_object *obj;
binder_size_t *offs = (binder_size_t *)(uintptr_t)txn->data.ptr.offsets;
size_t count = txn->offsets_size / sizeof(binder_size_t);
fprintf(stderr," target %016"PRIx64" cookie %016"PRIx64" code %08x flags %08x\n",
(uint64_t)txn->target.ptr, (uint64_t)txn->cookie, txn->code, txn->flags);
fprintf(stderr," pid %8d uid %8d data %"PRIu64" offs %"PRIu64"\n",
txn->sender_pid, txn->sender_euid, (uint64_t)txn->data_size, (uint64_t)txn->offsets_size);
hexdump((void *)(uintptr_t)txn->data.ptr.buffer, txn->data_size);
while (count--) {
obj = (struct flat_binder_object *) (((char*)(uintptr_t)txn->data.ptr.buffer) + *offs++);
fprintf(stderr," - type %08x flags %08x ptr %016"PRIx64" cookie %016"PRIx64"\n",
obj->hdr.type, obj->flags, (uint64_t)obj->binder, (uint64_t)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 *binder_open(char *device, size_t mapsize)
{
struct binder_state *bs;
struct binder_version vers;
bs = malloc(sizeof(*bs));
if (!bs) {
errno = ENOMEM;
return NULL;
}
bs->fd = open(device, O_RDWR | O_CLOEXEC);
if (bs->fd < 0) {
fprintf(stderr,"binder: cannot open device (%s)\n",
strerror(errno));
goto fail_open;
}
if ((ioctl(bs->fd, BINDER_VERSION, &vers) == -1) ||
(vers.protocol_version != BINDER_CURRENT_PROTOCOL_VERSION)) {
fprintf(stderr,
"binder: kernel driver version (%d) differs from user space version (%d)\n",
vers.protocol_version, BINDER_CURRENT_PROTOCOL_VERSION);
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;
}
if (madvise(bs->mapped, mapsize, MADV_DOFORK)) err(1, "MADV_DOFORK");
return bs;
fail_map:
close(bs->fd);
fail_open:
free(bs);
return NULL;
}
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, size_t len)
{
struct binder_write_read bwr;
int res;
bwr.write_size = len;
bwr.write_consumed = 0;
bwr.write_buffer = (uintptr_t) 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,
binder_uintptr_t buffer_to_free,
int status)
{
printf("binder_send_reply(status=%d)\n", status);
struct {
uint32_t cmd_free;
binder_uintptr_t buffer;
uint32_t cmd_reply;
struct binder_transaction_data_sg txn_sg;
} __attribute__((packed)) data;
data.cmd_free = BC_FREE_BUFFER;
data.buffer = buffer_to_free;
data.cmd_reply = BC_REPLY_SG;
data.txn_sg.buffers_size = reply->buffers_size;
data.txn_sg.transaction_data.target.ptr = 0;
data.txn_sg.transaction_data.cookie = 0;
data.txn_sg.transaction_data.code = 0;
if (status) {
data.txn_sg.transaction_data.flags = TF_STATUS_CODE;
data.txn_sg.transaction_data.data_size = sizeof(int);
data.txn_sg.transaction_data.offsets_size = 0;
data.txn_sg.transaction_data.data.ptr.buffer = (uintptr_t)&status;
data.txn_sg.transaction_data.data.ptr.offsets = 0;
} else {
data.txn_sg.transaction_data.flags = 0;
data.txn_sg.transaction_data.data_size = reply->data - reply->data0;
data.txn_sg.transaction_data.offsets_size = ((char*) reply->offs) - ((char*) reply->offs0);
data.txn_sg.transaction_data.data.ptr.buffer = (uintptr_t)reply->data0;
data.txn_sg.transaction_data.data.ptr.offsets = (uintptr_t)reply->offs0;
if (data.txn_sg.transaction_data.offsets_size) {
*(volatile unsigned long *)data.txn_sg.transaction_data.data.ptr.offsets;
}
printf("offsets=%p, offsets_size=%lu\n",
reply->offs0,
(unsigned long)data.txn_sg.transaction_data.offsets_size);
}
binder_write(bs, &data, sizeof(data));
}
int binder_parse(struct binder_state *bs, struct binder_io *bio,
uintptr_t ptr, size_t size, binder_handler func)
{
int r = 1;
uintptr_t end = ptr + (uintptr_t) size;
while (ptr < end) {
uint32_t cmd = *(uint32_t *) ptr;
ptr += sizeof(uint32_t);
#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," %p, %p\n", (void *)ptr, (void *)(ptr + sizeof(void *)));
#endif
ptr += sizeof(struct binder_ptr_cookie);
break;
case BR_TRANSACTION: {
struct binder_transaction_data *txn = (struct binder_transaction_data *) ptr;
if ((end - ptr) < sizeof(*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);
if ((txn->flags & 1) == 0) {
binder_send_reply(bs, &reply, txn->data.ptr.buffer, res);
}
}
ptr += sizeof(*txn);
break;
}
case BR_REPLY: {
struct binder_transaction_data *txn = (struct binder_transaction_data *) ptr;
if ((end - ptr) < sizeof(*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);
r = 0;
break;
}
case BR_DEAD_BINDER: {
struct binder_death *death = (struct binder_death *)(uintptr_t) *(binder_uintptr_t *)ptr;
ptr += sizeof(binder_uintptr_t);
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, uint32_t target)
{
uint32_t cmd[2];
cmd[0] = BC_ACQUIRE;
cmd[1] = target;
binder_write(bs, cmd, sizeof(cmd));
}
void binder_release(struct binder_state *bs, uint32_t target)
{
uint32_t cmd[2];
cmd[0] = BC_RELEASE;
cmd[1] = target;
binder_write(bs, cmd, sizeof(cmd));
}
void binder_increfs(struct binder_state *bs, uint32_t target)
{
uint32_t cmd[2];
cmd[0] = BC_INCREFS;
cmd[1] = target;
binder_write(bs, cmd, sizeof(cmd));
}
void binder_decrefs(struct binder_state *bs, uint32_t target)
{
uint32_t cmd[2];
cmd[0] = BC_DECREFS;
cmd[1] = target;
binder_write(bs, cmd, sizeof(cmd));
}
void binder_link_to_death(struct binder_state *bs, uint32_t target, struct binder_death *death)
{
struct {
uint32_t cmd;
struct binder_handle_cookie payload;
} __attribute__((packed)) data;
data.cmd = BC_REQUEST_DEATH_NOTIFICATION;
data.payload.handle = target;
data.payload.cookie = (uintptr_t) death;
binder_write(bs, &data, sizeof(data));
}
int binder_call(struct binder_state *bs,
struct binder_io *msg, struct binder_io *reply,
uint32_t target, uint32_t code)
{
int res;
struct binder_write_read bwr;
struct {
uint32_t cmd;
struct binder_transaction_data_sg txn_sg;
} __attribute__((packed)) writebuf;
unsigned readbuf[32];
if (msg->flags & BIO_F_OVERFLOW) {
fprintf(stderr,"binder: txn buffer overflow\n");
goto fail;
}
writebuf.cmd = BC_TRANSACTION_SG;
writebuf.txn_sg.buffers_size = msg->buffers_size;
writebuf.txn_sg.transaction_data.target.handle = target;
writebuf.txn_sg.transaction_data.code = code;
writebuf.txn_sg.transaction_data.flags = TF_ACCEPT_FDS;
writebuf.txn_sg.transaction_data.data_size = msg->data - msg->data0;
writebuf.txn_sg.transaction_data.offsets_size = ((char*) msg->offs) - ((char*) msg->offs0);
writebuf.txn_sg.transaction_data.data.ptr.buffer = (uintptr_t)msg->data0;
writebuf.txn_sg.transaction_data.data.ptr.offsets = (uintptr_t)msg->offs0;
bwr.write_size = sizeof(writebuf);
bwr.write_consumed = 0;
bwr.write_buffer = (uintptr_t) &writebuf;
hexdump(msg->data0, msg->data - msg->data0);
bool first_iter = false;
for (;;) {
bwr.read_size = sizeof(readbuf);
bwr.read_consumed = 0;
bwr.read_buffer = (uintptr_t) readbuf;
if (first_iter) {
bwr.read_size = 0;
printf("%d forking...\n", getpid());
pid_t child = fork();
if (child == -1) err(1, "fork");
if (child == 0) {
printf("entering child: %d\n", getpid());
res = ioctl(bs->fd, BINDER_WRITE_READ, &bwr);
if (res < 0) {
fprintf(stderr,"binder: ioctl failed (%s)\n", strerror(errno));
}
if (bwr.write_consumed != bwr.write_size) {
errx(1, "write_consumed != write_size");
}
printf("child exiting\n");
exit(0);
}
int status;
if (wait(&status) != child) err(1, "wait for child");
bwr.write_consumed = bwr.write_size;
printf("child is dead\n");
} else {
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, (uintptr_t) readbuf, bwr.read_consumed, 0);
if (res == 0) return 0;
if (res < 0) goto fail;
}
first_iter = false;
}
fail:
memset(reply, 0, sizeof(*reply));
reply->flags |= BIO_F_IOERROR;
return -1;
}
int binder_call_async(struct binder_state *bs,
struct binder_io *msg, uint32_t target, uint32_t code)
{
int res;
struct binder_write_read bwr;
struct {
uint32_t cmd;
struct binder_transaction_data txn;
} __attribute__((packed)) writebuf;
if (msg->flags & BIO_F_OVERFLOW) {
fprintf(stderr,"binder: txn buffer overflow\n");
goto fail;
}
writebuf.cmd = BC_TRANSACTION;
writebuf.txn.target.handle = target;
writebuf.txn.code = code;
writebuf.txn.flags = TF_ACCEPT_FDS;
writebuf.txn.data_size = msg->data - msg->data0;
writebuf.txn.offsets_size = ((char*) msg->offs) - ((char*) msg->offs0);
writebuf.txn.data.ptr.buffer = (uintptr_t)msg->data0;
writebuf.txn.data.ptr.offsets = (uintptr_t)msg->offs0;
bwr.write_size = sizeof(writebuf);
bwr.write_consumed = 0;
bwr.write_buffer = (uintptr_t) &writebuf;
bwr.read_size = 0;
bwr.read_buffer = 0;
bwr.read_consumed = 0;
hexdump(msg->data0, msg->data - msg->data0);
res = ioctl(bs->fd, BINDER_WRITE_READ, &bwr);
if (res < 0) {
fprintf(stderr,"binder: ioctl failed (%s)\n", strerror(errno));
goto fail;
}
return 0;
fail:
return -1;
}
int binder_read_reply(struct binder_state* bs,
struct binder_io* reply)
{
int res;
struct binder_write_read bwr;
unsigned readbuf[32];
bwr.write_size = 0;
bwr.write_consumed = 0;
bwr.write_buffer = 0;
for (;;) {
bwr.read_size = sizeof(readbuf);
bwr.read_consumed = 0;
bwr.read_buffer = (uintptr_t) 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, (uintptr_t) 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;
}
int binder_read_reply_handler(struct binder_state* bs,
struct binder_io* reply, 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;
for (;;) {
bwr.read_size = sizeof(readbuf);
bwr.read_consumed = 0;
bwr.read_buffer = (uintptr_t) 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, (uintptr_t) readbuf, bwr.read_consumed, func);
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;
uint32_t readbuf[32];
bwr.write_size = 0;
bwr.write_consumed = 0;
bwr.write_buffer = 0;
readbuf[0] = BC_ENTER_LOOPER;
binder_write(bs, readbuf, sizeof(uint32_t));
for (;;) {
bwr.read_size = sizeof(readbuf);
bwr.read_consumed = 0;
bwr.read_buffer = (uintptr_t) readbuf;
res = ioctl(bs->fd, BINDER_WRITE_READ, &bwr);
if (res < 0) {
fprintf(stderr,"binder_loop: ioctl failed (%s)\n", strerror(errno));
break;
}
res = binder_parse(bs, 0, (uintptr_t) readbuf, bwr.read_consumed, func);
if (res == 0) {
fprintf(stderr,"binder_loop: unexpected reply?!\n");
break;
}
if (res < 0) {
fprintf(stderr,"binder_loop: io error %d %s\n", res, strerror(errno));
break;
}
}
}
void bio_init_from_txn(struct binder_io *bio, struct binder_transaction_data *txn)
{
bio->data = bio->data0 = (char *)(intptr_t)txn->data.ptr.buffer;
bio->offs = bio->offs0 = (binder_size_t *)(intptr_t)txn->data.ptr.offsets;
bio->data_avail = txn->data_size;
bio->offs_avail = txn->offsets_size / sizeof(size_t);
bio->flags = BIO_F_SHARED;
}
void bio_init(struct binder_io *bio, void *data,
size_t maxdata, size_t maxoffs)
{
size_t n = maxoffs * sizeof(size_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;
bio->buffers_size = 0;
}
static void *bio_alloc(struct binder_io *bio, size_t size)
{
size = (size + 3) & (~3);
if (size > bio->data_avail) {
bio->flags |= BIO_F_OVERFLOW;
return NULL;
} 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)
{
struct {
uint32_t cmd;
uintptr_t buffer;
} __attribute__((packed)) data;
if (reply->flags & BIO_F_SHARED) {
printf("binder_done: freeing buffer\n");
data.cmd = BC_FREE_BUFFER;
data.buffer = (uintptr_t) reply->data0;
binder_write(bs, &data, sizeof(data));
reply->flags = 0;
printf("binder_done: free done\n");
}
}
static struct flat_binder_object *bio_alloc_obj(struct binder_io *bio)
{
struct flat_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 NULL;
}
static struct binder_fd_array_object *bio_alloc_fda(struct binder_io *bio)
{
struct binder_fd_array_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 NULL;
}
static struct binder_buffer_object *bio_alloc_buf(struct binder_io *bio, int *buf_id)
{
struct binder_buffer_object *obj;
obj = bio_alloc(bio, sizeof(*obj));
if (obj && bio->offs_avail) {
bio->offs_avail--;
if (buf_id) *buf_id = bio->offs - bio->offs0;
*bio->offs++ = ((char*) obj) - ((char*) bio->data0);
return obj;
}
bio->flags |= BIO_F_OVERFLOW;
return NULL;
}
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 flat_binder_object *obj;
obj = bio_alloc_obj(bio);
if (!obj)
return;
obj->flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
obj->hdr.type = BINDER_TYPE_BINDER;
obj->binder = (uintptr_t)ptr;
obj->cookie = 0;
}
void bio_put_fd(struct binder_io *bio, int fd)
{
struct flat_binder_object *obj;
obj = bio_alloc_obj(bio);
if (!obj)
return;
obj->flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
obj->hdr.type = BINDER_TYPE_FD;
obj->binder = (uintptr_t)fd;
obj->cookie = 0;
}
void bio_put_buf(struct binder_io *bio, void *data, size_t len, int *buf_id) {
struct binder_buffer_object *obj;
obj = bio_alloc_buf(bio, buf_id);
if (!obj)
return;
obj->hdr.type = BINDER_TYPE_PTR;
obj->flags = 0;
obj->buffer = (unsigned long)data;
obj->length = len;
obj->parent = 0; // unused
obj->parent_offset = 0; // unused
bio->buffers_size += (len+7)&~7UL; // TODO rounding blargh
}
void bio_put_sub_buf(struct binder_io *bio, int parent_id, int parent_offset, void *data, size_t len, int *buf_id) {
struct binder_buffer_object *obj;
obj = bio_alloc_buf(bio, buf_id);
if (!obj)
return;
obj->hdr.type = BINDER_TYPE_PTR;
obj->flags = BINDER_BUFFER_FLAG_HAS_PARENT;
obj->buffer = (unsigned long)data;
obj->length = len;
obj->parent = parent_id;
obj->parent_offset = parent_offset;
bio->buffers_size += (len+7)&~7UL; // TODO rounding blargh
}
void bio_put_fda(struct binder_io *bio, int *fds, int fd_count) {
int buf_id = -1;
bio_put_buf(bio, fds, sizeof(int)*fd_count, &buf_id);
if (buf_id == -1) errx(1, "bio_put_buf fail");
struct binder_fd_array_object *obj;
obj = bio_alloc_fda(bio);
if (!obj)
return;
obj->hdr.type = BINDER_TYPE_FDA;
obj->num_fds = fd_count;
printf("fda->parent = %d\n", buf_id);
obj->parent = buf_id;
obj->parent_offset = 0;
}
void bio_put_ref(struct binder_io *bio, uint32_t handle)
{
struct flat_binder_object *obj;
if (handle)
obj = bio_alloc_obj(bio);
else
obj = bio_alloc(bio, sizeof(*obj));
if (!obj)
return;
obj->flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
obj->hdr.type = BINDER_TYPE_HANDLE;
obj->handle = handle;
obj->cookie = 0;
}
void bio_put_string16(struct binder_io *bio, const uint16_t *str)
{
size_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;
}
/* Note: The payload will carry 32bit size instead of size_t */
bio_put_uint32(bio, (uint32_t) len);
len = (len + 1) * sizeof(uint16_t);
ptr = bio_alloc(bio, len);
if (ptr)
memcpy(ptr, str, len);
}
void bio_put_cstring(struct binder_io *bio, const char *str)
{
char* ptr = NULL;
size_t len = 0;
len = strlen(str) + 1;
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;
size_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;
}
/* Note: The payload will carry 32bit size instead of size_t */
bio_put_uint32(bio, len);
ptr = bio_alloc(bio, (len + 1) * sizeof(uint16_t));
if (!ptr)
return;
while (*str)
*ptr++ = *str++;
*ptr++ = 0;
}
void bio_put_string8_x(struct binder_io *bio, const char *_str)
{
unsigned char *str = (unsigned char*) _str;
size_t len;
uint8_t *ptr;
if (!str) {
bio_put_uint32(bio, 0xffffffff);
return;
}
len = strlen(_str);
if (len >= (MAX_BIO_SIZE / sizeof(uint8_t))) {
bio_put_uint32(bio, 0xffffffff);
return;
}
/* Note: The payload will carry 32bit size instead of size_t */
bio_put_uint32(bio, len);
ptr = bio_alloc(bio, (len + 1) * sizeof(uint8_t));
if (!ptr)
return;
while (*str)
*ptr++ = *str++;
*ptr++ = 0;
}
static void *bio_get(struct binder_io *bio, size_t size)
{
size = (size + 3) & (~3);
if (bio->data_avail < size){
bio->data_avail = 0;
bio->flags |= BIO_F_OVERFLOW;
return NULL;
} 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, size_t *sz)
{
size_t len;
/* Note: The payload will carry 32bit size instead of size_t */
len = (size_t) bio_get_uint32(bio);
if (sz)
*sz = len;
return bio_get(bio, (len + 1) * sizeof(uint16_t));
}
char *bio_get_string8(struct binder_io *bio, size_t *sz) {
size_t len;
/* Note: The payload will carry 32bit size instead of size_t */
len = (size_t) bio_get_uint32(bio);
if (sz)
*sz = len;
return bio_get(bio, len + 1);
}
static struct flat_binder_object *_bio_get_obj(struct binder_io *bio)
{
size_t n;
size_t 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 flat_binder_object));
}
bio->data_avail = 0;
bio->flags |= BIO_F_OVERFLOW;
return NULL;
}
uint32_t bio_get_ref(struct binder_io *bio)
{
struct flat_binder_object *obj;
obj = _bio_get_obj(bio);
if (!obj)
return 0;
if (obj->hdr.type == BINDER_TYPE_HANDLE)
return obj->handle;
return 0;
}
uint32_t bio_get_ref_cookie(struct binder_io *bio, uint64_t* cookie) {
struct flat_binder_object *obj;
obj = _bio_get_obj(bio);
if (!obj)
return 0;
if (obj->hdr.type == BINDER_TYPE_HANDLE || obj->hdr.type == BINDER_TYPE_WEAK_HANDLE) {
*cookie = obj->cookie;
return obj->handle;
}
return 0;
}
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