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Administrator
Magisk
Commits
8893cbd6
Commit
8893cbd6
authored
Mar 15, 2019
by
topjohnwu
Browse files
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Plain Diff
Modularize MagiskInit
parent
f0240b1f
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1 changed file
with
317 additions
and
295 deletions
+317
-295
init.cpp
native/jni/core/init.cpp
+317
-295
No files found.
native/jni/core/init.cpp
View file @
8893cbd6
...
...
@@ -53,19 +53,10 @@
#define DEFAULT_DT_DIR "/proc/device-tree/firmware/android"
int
(
*
init_applet_main
[])
(
int
,
char
*
[])
=
{
magiskpolicy_main
,
magiskpolicy_main
,
nullptr
};
static
bool
mnt_system
=
false
;
static
bool
mnt_vendor
=
false
;
static
bool
mnt_product
=
false
;
static
bool
mnt_odm
=
false
;
static
bool
kirin
=
false
;
static
void
*
self
,
*
config
;
static
size_t
self_sz
,
config_sz
;
int
(
*
init_applet_main
[])(
int
,
char
*
[])
=
{
magiskpolicy_main
,
magiskpolicy_main
,
nullptr
};
struct
cmdline
{
bool
early_b
oot
;
bool
system_as_r
oot
;
char
slot
[
3
];
char
dt_dir
[
128
];
};
...
...
@@ -78,7 +69,102 @@ struct device {
char
path
[
64
];
};
static
void
parse_cmdline
(
const
std
::
function
<
void
(
std
::
string_view
,
const
char
*
)
>
&
fn
)
{
struct
raw_data
{
void
*
buf
;
size_t
sz
;
};
static
bool
unxz
(
int
fd
,
const
uint8_t
*
buf
,
size_t
size
)
{
uint8_t
out
[
8192
];
xz_crc32_init
();
struct
xz_dec
*
dec
=
xz_dec_init
(
XZ_DYNALLOC
,
1
<<
26
);
struct
xz_buf
b
=
{
.
in
=
buf
,
.
in_pos
=
0
,
.
in_size
=
size
,
.
out
=
out
,
.
out_pos
=
0
,
.
out_size
=
sizeof
(
out
)
};
enum
xz_ret
ret
;
do
{
ret
=
xz_dec_run
(
dec
,
&
b
);
if
(
ret
!=
XZ_OK
&&
ret
!=
XZ_STREAM_END
)
return
false
;
write
(
fd
,
out
,
b
.
out_pos
);
b
.
out_pos
=
0
;
}
while
(
b
.
in_pos
!=
size
);
return
true
;
}
static
void
decompress_ramdisk
()
{
constexpr
char
tmp
[]
=
"tmp.cpio"
;
constexpr
char
ramdisk_xz
[]
=
"ramdisk.cpio.xz"
;
if
(
access
(
ramdisk_xz
,
F_OK
))
return
;
uint8_t
*
buf
;
size_t
sz
;
mmap_ro
(
ramdisk_xz
,
buf
,
sz
);
int
fd
=
open
(
tmp
,
O_WRONLY
|
O_CREAT
|
O_TRUNC
|
O_CLOEXEC
);
unxz
(
fd
,
buf
,
sz
);
munmap
(
buf
,
sz
);
close
(
fd
);
cpio_mmap
cpio
(
tmp
);
cpio
.
extract
();
unlink
(
tmp
);
unlink
(
ramdisk_xz
);
}
static
int
dump_magisk
(
const
char
*
path
,
mode_t
mode
)
{
int
fd
=
open
(
path
,
O_WRONLY
|
O_CREAT
|
O_TRUNC
|
O_CLOEXEC
,
mode
);
if
(
fd
<
0
)
return
1
;
if
(
!
unxz
(
fd
,
magisk_xz
,
sizeof
(
magisk_xz
)))
return
1
;
close
(
fd
);
return
0
;
}
static
int
dump_manager
(
const
char
*
path
,
mode_t
mode
)
{
int
fd
=
open
(
path
,
O_WRONLY
|
O_CREAT
|
O_TRUNC
|
O_CLOEXEC
,
mode
);
if
(
fd
<
0
)
return
1
;
if
(
!
unxz
(
fd
,
manager_xz
,
sizeof
(
manager_xz
)))
return
1
;
close
(
fd
);
return
0
;
}
class
MagiskInit
{
private
:
cmdline
cmd
{};
raw_data
init
{};
raw_data
config
{};
int
root
=
-
1
;
bool
mnt_system
=
false
;
bool
mnt_vendor
=
false
;
bool
mnt_product
=
false
;
bool
mnt_odm
=
false
;
bool
kirin
=
false
;
char
**
argv
;
void
load_kernel_info
();
void
preset
();
void
early_mount
();
void
setup_rootfs
();
bool
read_dt_fstab
(
const
char
*
mnt_point
,
char
*
partname
,
char
*
partfs
);
bool
patch_sepolicy
();
void
cleanup
();
public
:
explicit
MagiskInit
(
char
*
argv
[])
:
argv
(
argv
)
{}
void
setup_overlay
();
void
re_exec_init
();
void
start
();
void
test
();
};
static
inline
void
parse_cmdline
(
const
std
::
function
<
void
(
std
::
string_view
,
const
char
*
)
>
&
fn
)
{
char
cmdline
[
4096
];
int
fd
=
open
(
"/proc/cmdline"
,
O_RDONLY
|
O_CLOEXEC
);
cmdline
[
read
(
fd
,
cmdline
,
sizeof
(
cmdline
))]
=
'\0'
;
...
...
@@ -106,7 +192,13 @@ static void parse_cmdline(const std::function<void (std::string_view, const char
}
}
static
void
parse_cmdline
(
struct
cmdline
*
cmd
)
{
void
MagiskInit
::
load_kernel_info
()
{
// Communicate with kernel using procfs and sysfs
mkdir
(
"/proc"
,
0755
);
xmount
(
"proc"
,
"/proc"
,
"proc"
,
0
,
nullptr
);
mkdir
(
"/sys"
,
0755
);
xmount
(
"sysfs"
,
"/sys"
,
"sysfs"
,
0
,
nullptr
);
char
cmdline
[
4096
];
int
fd
=
open
(
"/proc/cmdline"
,
O_RDONLY
|
O_CLOEXEC
);
cmdline
[
read
(
fd
,
cmdline
,
sizeof
(
cmdline
))]
=
'\0'
;
...
...
@@ -117,14 +209,14 @@ static void parse_cmdline(struct cmdline *cmd) {
parse_cmdline
([
&
](
auto
key
,
auto
value
)
->
void
{
LOGD
(
"cmdline: [%s]=[%s]
\n
"
,
key
.
data
(),
value
);
if
(
key
==
"androidboot.slot_suffix"
)
{
strcpy
(
cmd
->
slot
,
value
);
strcpy
(
cmd
.
slot
,
value
);
}
else
if
(
key
==
"androidboot.slot"
)
{
cmd
->
slot
[
0
]
=
'_'
;
strcpy
(
cmd
->
slot
+
1
,
value
);
cmd
.
slot
[
0
]
=
'_'
;
strcpy
(
cmd
.
slot
+
1
,
value
);
}
else
if
(
key
==
"skip_initramfs"
)
{
skip_initramfs
=
true
;
}
else
if
(
key
==
"androidboot.android_dt_dir"
)
{
strcpy
(
cmd
->
dt_dir
,
value
);
strcpy
(
cmd
.
dt_dir
,
value
);
}
else
if
(
key
==
"enter_recovery"
)
{
enter_recovery
=
value
[
0
]
==
'1'
;
}
else
if
(
key
==
"androidboot.hardware"
)
{
...
...
@@ -138,19 +230,40 @@ static void parse_cmdline(struct cmdline *cmd) {
fprintf
(
f
,
"RECOVERYMODE=true
\n
"
);
fclose
(
f
);
}
cmd
->
early_b
oot
=
true
;
cmd
.
system_as_r
oot
=
true
;
}
cmd
.
system_as_root
|=
skip_initramfs
;
if
(
cmd
.
dt_dir
[
0
]
==
'\0'
)
strcpy
(
cmd
.
dt_dir
,
DEFAULT_DT_DIR
);
cmd
->
early_boot
|=
skip_initramfs
;
LOGD
(
"system_as_root[%d] slot[%s] dt_dir[%s]
\n
"
,
cmd
.
system_as_root
,
cmd
.
slot
,
cmd
.
dt_dir
);
}
if
(
cmd
->
dt_dir
[
0
]
==
'\0'
)
strcpy
(
cmd
->
dt_dir
,
DEFAULT_DT_DIR
);
void
MagiskInit
::
preset
()
{
root
=
open
(
"/"
,
O_RDONLY
|
O_CLOEXEC
);
LOGD
(
"cmdline: early_boot[%d] slot[%s] dt_dir[%s]
\n
"
,
cmd
->
early_boot
,
cmd
->
slot
,
cmd
->
dt_dir
);
if
(
cmd
.
system_as_root
)
{
// Clear rootfs
const
char
*
excl
[]
=
{
"overlay"
,
"proc"
,
"sys"
,
nullptr
};
excl_list
=
excl
;
frm_rf
(
root
);
excl_list
=
nullptr
;
}
else
{
decompress_ramdisk
();
// Revert original init binary
rename
(
"/.backup/init"
,
"/init"
);
rm_rf
(
"/.backup"
);
// Do not go further if device is booting into recovery
if
(
access
(
"/sbin/recovery"
,
F_OK
)
==
0
)
re_exec_init
();
}
}
static
void
parse_device
(
struct
device
*
dev
,
const
char
*
uevent
)
{
static
inline
void
parse_device
(
struct
device
*
dev
,
const
char
*
uevent
)
{
dev
->
partname
[
0
]
=
'\0'
;
FILE
*
fp
=
xfopen
(
uevent
,
"r"
);
char
buf
[
64
];
...
...
@@ -205,31 +318,112 @@ static inline bool is_lnk(const char *name) {
return
S_ISLNK
(
st
.
st_mode
);
}
static
bool
read_fstab_dt
(
const
struct
cmdline
*
cmd
,
const
char
*
mnt_point
,
char
*
partname
,
char
*
partfs
)
{
char
buf
[
128
];
struct
stat
st
;
sprintf
(
buf
,
"/%s"
,
mnt_point
);
if
(
is_lnk
(
buf
))
return
false
;
int
fd
;
sprintf
(
buf
,
"%s/fstab/%s/dev"
,
cmd
->
dt_dir
,
mnt_point
);
if
((
fd
=
xopen
(
buf
,
O_RDONLY
|
O_CLOEXEC
))
>=
0
)
{
read
(
fd
,
buf
,
sizeof
(
buf
));
close
(
fd
);
char
*
name
=
rtrim
(
strrchr
(
buf
,
'/'
)
+
1
);
sprintf
(
partname
,
"%s%s"
,
name
,
strend
(
name
,
cmd
->
slot
)
?
cmd
->
slot
:
""
);
sprintf
(
buf
,
"%s/fstab/%s/type"
,
cmd
->
dt_dir
,
mnt_point
);
if
((
fd
=
xopen
(
buf
,
O_RDONLY
|
O_CLOEXEC
))
>=
0
)
{
lstat
(
buf
,
&
st
);
read
(
fd
,
partfs
,
st
.
st_size
);
close
(
fd
);
return
true
;
#define link_root(part) \
if (is_lnk("/system_root" part)) \
cp_afc("/system_root" part, part)
#define mount_root(part) \
if (!is_lnk("/" #part) && read_dt_fstab(#part, partname, fstype)) { \
setup_block(&dev, partname); \
xmkdir("/" #part, 0755); \
xmount(dev.path, "/" #part, fstype, MS_RDONLY, nullptr); \
mnt_##part = true; \
}
void
MagiskInit
::
early_mount
()
{
struct
device
dev
;
char
partname
[
32
];
char
fstype
[
32
];
if
(
cmd
.
system_as_root
)
{
sprintf
(
partname
,
"system%s"
,
cmd
.
slot
);
setup_block
(
&
dev
,
partname
);
xmkdir
(
"/system_root"
,
0755
);
xmount
(
dev
.
path
,
"/system_root"
,
"ext4"
,
MS_RDONLY
,
nullptr
);
xmkdir
(
"/system"
,
0755
);
xmount
(
"/system_root/system"
,
"/system"
,
nullptr
,
MS_BIND
,
nullptr
);
// Copy if these partitions are symlinks
link_root
(
"/vendor"
);
link_root
(
"/product"
);
link_root
(
"/odm"
);
}
else
{
mount_root
(
system
);
}
mount_root
(
vendor
);
mount_root
(
product
);
mount_root
(
odm
);
}
void
MagiskInit
::
setup_rootfs
()
{
bool
patch_init
=
patch_sepolicy
();
if
(
cmd
.
system_as_root
)
{
// Clone rootfs except /system
int
system_root
=
open
(
"/system_root"
,
O_RDONLY
|
O_CLOEXEC
);
const
char
*
excl
[]
=
{
"system"
,
nullptr
};
excl_list
=
excl
;
clone_dir
(
system_root
,
root
);
close
(
system_root
);
excl_list
=
nullptr
;
}
if
(
patch_init
)
{
constexpr
char
SYSTEM_INIT
[]
=
"/system/bin/init"
;
// If init is symlink, copy it to rootfs so we can patch
struct
stat
st
;
lstat
(
"/init"
,
&
st
);
if
(
S_ISLNK
(
st
.
st_mode
))
cp_afc
(
SYSTEM_INIT
,
"/init"
);
char
*
addr
;
size_t
size
;
mmap_rw
(
"/init"
,
addr
,
size
);
for
(
char
*
p
=
addr
;
p
<
addr
+
size
;
++
p
)
{
if
(
memcmp
(
p
,
SPLIT_PLAT_CIL
,
sizeof
(
SPLIT_PLAT_CIL
))
==
0
)
{
// Force init to load /sepolicy
memset
(
p
,
'x'
,
sizeof
(
SPLIT_PLAT_CIL
)
-
1
);
p
+=
sizeof
(
SPLIT_PLAT_CIL
)
-
1
;
}
else
if
(
memcmp
(
p
,
SYSTEM_INIT
,
sizeof
(
SYSTEM_INIT
))
==
0
)
{
// Force execute /init instead of /system/bin/init
strcpy
(
p
,
"/init"
);
p
+=
sizeof
(
SYSTEM_INIT
)
-
1
;
}
}
munmap
(
addr
,
size
);
}
return
false
;
// Handle ramdisk overlays
int
fd
=
open
(
"/overlay"
,
O_RDONLY
|
O_CLOEXEC
);
if
(
fd
>=
0
)
{
mv_dir
(
fd
,
root
);
close
(
fd
);
rmdir
(
"/overlay"
);
}
// Patch init.rc
FILE
*
rc
=
xfopen
(
"/init.rc"
,
"ae"
);
char
pfd_svc
[
8
],
ls_svc
[
8
];
gen_rand_str
(
pfd_svc
,
sizeof
(
pfd_svc
));
do
{
gen_rand_str
(
ls_svc
,
sizeof
(
ls_svc
));
}
while
(
strcmp
(
pfd_svc
,
ls_svc
)
==
0
);
fprintf
(
rc
,
magiskrc
,
pfd_svc
,
pfd_svc
,
ls_svc
);
fclose
(
rc
);
// Don't let init run in init yet
lsetfilecon
(
"/init"
,
"u:object_r:rootfs:s0"
);
// Create hardlink mirror of /sbin to /root
mkdir
(
"/root"
,
0750
);
clone_attr
(
"/sbin"
,
"/root"
);
int
rootdir
=
xopen
(
"/root"
,
O_RDONLY
|
O_CLOEXEC
);
int
sbin
=
xopen
(
"/sbin"
,
O_RDONLY
|
O_CLOEXEC
);
link_dir
(
sbin
,
rootdir
);
}
static
bool
patch_sepolicy
()
{
bool
MagiskInit
::
patch_sepolicy
()
{
bool
patch_init
=
false
;
if
(
access
(
SPLIT_PLAT_CIL
,
R_OK
)
==
0
)
...
...
@@ -265,68 +459,40 @@ static bool patch_sepolicy() {
return
patch_init
;
}
static
bool
unxz
(
int
fd
,
const
uint8_t
*
buf
,
size_t
size
)
{
uint8_t
out
[
8192
];
xz_crc32_init
();
struct
xz_dec
*
dec
=
xz_dec_init
(
XZ_DYNALLOC
,
1
<<
26
);
struct
xz_buf
b
=
{
.
in
=
buf
,
.
in_pos
=
0
,
.
in_size
=
size
,
.
out
=
out
,
.
out_pos
=
0
,
.
out_size
=
sizeof
(
out
)
};
enum
xz_ret
ret
;
do
{
ret
=
xz_dec_run
(
dec
,
&
b
);
if
(
ret
!=
XZ_OK
&&
ret
!=
XZ_STREAM_END
)
return
false
;
write
(
fd
,
out
,
b
.
out_pos
);
b
.
out_pos
=
0
;
}
while
(
b
.
in_pos
!=
size
);
return
true
;
}
static
void
decompress_ramdisk
()
{
constexpr
char
tmp
[]
=
"tmp.cpio"
;
constexpr
char
ramdisk_xz
[]
=
"ramdisk.cpio.xz"
;
if
(
access
(
ramdisk_xz
,
F_OK
))
return
;
uint8_t
*
buf
;
size_t
sz
;
mmap_ro
(
ramdisk_xz
,
buf
,
sz
);
int
fd
=
open
(
tmp
,
O_WRONLY
|
O_CREAT
|
O_TRUNC
|
O_CLOEXEC
);
unxz
(
fd
,
buf
,
sz
);
munmap
(
buf
,
sz
);
close
(
fd
);
cpio_mmap
cpio
(
tmp
);
cpio
.
extract
();
unlink
(
tmp
);
unlink
(
ramdisk_xz
);
bool
MagiskInit
::
read_dt_fstab
(
const
char
*
mnt_point
,
char
*
partname
,
char
*
partfs
)
{
char
path
[
128
];
int
fd
;
sprintf
(
path
,
"%s/fstab/%s/dev"
,
cmd
.
dt_dir
,
mnt_point
);
if
((
fd
=
xopen
(
path
,
O_RDONLY
|
O_CLOEXEC
))
>=
0
)
{
read
(
fd
,
path
,
sizeof
(
path
));
close
(
fd
);
char
*
name
=
rtrim
(
strrchr
(
path
,
'/'
)
+
1
);
sprintf
(
partname
,
"%s%s"
,
name
,
strend
(
name
,
cmd
.
slot
)
?
cmd
.
slot
:
""
);
sprintf
(
path
,
"%s/fstab/%s/type"
,
cmd
.
dt_dir
,
mnt_point
);
if
((
fd
=
xopen
(
path
,
O_RDONLY
|
O_CLOEXEC
))
>=
0
)
{
read
(
fd
,
partfs
,
32
);
close
(
fd
);
return
true
;
}
}
return
false
;
}
static
int
dump_magisk
(
const
char
*
path
,
mode_t
mode
)
{
int
fd
=
open
(
path
,
O_WRONLY
|
O_CREAT
|
O_TRUNC
|
O_CLOEXEC
,
mode
);
if
(
fd
<
0
)
return
1
;
if
(
!
unxz
(
fd
,
magisk_xz
,
sizeof
(
magisk_xz
)))
return
1
;
close
(
fd
);
return
0
;
}
#define umount_part(part) \
if (mnt_##part) \
umount("/" #part);
static
int
dump_manager
(
const
char
*
path
,
mode_t
mode
)
{
int
fd
=
open
(
path
,
O_WRONLY
|
O_CREAT
|
O_TRUNC
|
O_CLOEXEC
,
mode
);
if
(
fd
<
0
)
return
1
;
if
(
!
unxz
(
fd
,
manager_xz
,
sizeof
(
manager_xz
)))
return
1
;
close
(
fd
);
return
0
;
void
MagiskInit
::
cleanup
(
)
{
umount
(
SELINUX_MNT
);
umount
(
"/sys"
);
umount
(
"/proc"
)
;
umount_part
(
system
);
umount_part
(
vendor
)
;
umount_part
(
product
);
umount_part
(
odm
)
;
}
static
void
patch_socket_name
(
const
char
*
path
)
{
static
inline
void
patch_socket_name
(
const
char
*
path
)
{
uint8_t
*
buf
;
char
name
[
sizeof
(
MAIN_SOCKET
)];
size_t
size
;
...
...
@@ -346,19 +512,8 @@ static void patch_socket_name(const char *path) {
munmap
(
buf
,
size
);
}
static
void
setup_init_rc
()
{
FILE
*
rc
=
xfopen
(
"/init.rc"
,
"ae"
);
char
pfd_svc
[
8
],
ls_svc
[
8
];
gen_rand_str
(
pfd_svc
,
sizeof
(
pfd_svc
));
do
{
gen_rand_str
(
ls_svc
,
sizeof
(
ls_svc
));
}
while
(
strcmp
(
pfd_svc
,
ls_svc
)
==
0
);
fprintf
(
rc
,
magiskrc
,
pfd_svc
,
pfd_svc
,
ls_svc
);
fclose
(
rc
);
}
static
void
setup_overlay
()
{
char
buf
[
128
];
void
MagiskInit
::
setup_overlay
()
{
char
path
[
128
];
int
fd
;
// Wait for early-init start
...
...
@@ -375,10 +530,10 @@ static void setup_overlay() {
// Dump binaries
mkdir
(
MAGISKTMP
,
0755
);
fd
=
xopen
(
MAGISKTMP
"/config"
,
O_WRONLY
|
O_CREAT
,
0000
);
write
(
fd
,
config
,
config_
sz
);
write
(
fd
,
config
.
buf
,
config
.
sz
);
close
(
fd
);
fd
=
xopen
(
"/sbin/magiskinit"
,
O_WRONLY
|
O_CREAT
,
0755
);
write
(
fd
,
self
,
self_
sz
);
write
(
fd
,
init
.
buf
,
init
.
sz
);
close
(
fd
);
dump_magisk
(
"/sbin/magisk"
,
0755
);
patch_socket_name
(
"/sbin/magisk"
);
...
...
@@ -387,23 +542,23 @@ static void setup_overlay() {
// Create applet symlinks
for
(
int
i
=
0
;
applet_names
[
i
];
++
i
)
{
sprintf
(
buf
,
"/sbin/%s"
,
applet_names
[
i
]);
xsymlink
(
"/sbin/magisk"
,
buf
);
sprintf
(
path
,
"/sbin/%s"
,
applet_names
[
i
]);
xsymlink
(
"/sbin/magisk"
,
path
);
}
for
(
int
i
=
0
;
init_applet
[
i
];
++
i
)
{
sprintf
(
buf
,
"/sbin/%s"
,
init_applet
[
i
]);
xsymlink
(
"/sbin/magiskinit"
,
buf
);
sprintf
(
path
,
"/sbin/%s"
,
init_applet
[
i
]);
xsymlink
(
"/sbin/magiskinit"
,
path
);
}
// Create symlinks pointing back to /root
DIR
*
dir
;
DIR
*
dir
=
xopendir
(
"/root"
)
;
struct
dirent
*
entry
;
dir
=
xopendir
(
"/root"
);
fd
=
xopen
(
"/sbin"
,
O_RDONLY
);
while
((
entry
=
xreaddir
(
dir
)))
{
if
(
strcmp
(
entry
->
d_name
,
"."
)
==
0
||
strcmp
(
entry
->
d_name
,
".."
)
==
0
)
continue
;
snprintf
(
buf
,
PATH_MAX
,
"/root/%s"
,
entry
->
d_name
);
xsymlinkat
(
buf
,
fd
,
entry
->
d_name
);
if
(
strcmp
(
entry
->
d_name
,
"."
)
==
0
||
strcmp
(
entry
->
d_name
,
".."
)
==
0
)
continue
;
snprintf
(
path
,
PATH_MAX
,
"/root/%s"
,
entry
->
d_name
);
xsymlinkat
(
path
,
fd
,
entry
->
d_name
);
}
closedir
(
dir
);
close
(
fd
);
...
...
@@ -412,40 +567,13 @@ static void setup_overlay() {
exit
(
0
);
}
[[
noreturn
]]
static
void
exec_init
(
char
*
argv
[])
{
// Clean up
umount
(
SELINUX_MNT
);
umount
(
"/sys"
);
umount
(
"/proc"
);
if
(
mnt_system
)
umount
(
"/system"
);
if
(
mnt_vendor
)
umount
(
"/vendor"
);
if
(
mnt_product
)
umount
(
"/product"
);
if
(
mnt_odm
)
umount
(
"/odm"
);
void
MagiskInit
::
re_exec_init
()
{
cleanup
();
execv
(
"/init"
,
argv
);
exit
(
1
);
}
int
main
(
int
argc
,
char
*
argv
[])
{
umask
(
0
);
no_logging
();
for
(
int
i
=
0
;
init_applet
[
i
];
++
i
)
{
if
(
strcmp
(
basename
(
argv
[
0
]),
init_applet
[
i
])
==
0
)
return
(
*
init_applet_main
[
i
])(
argc
,
argv
);
}
if
(
argc
>
1
&&
strcmp
(
argv
[
1
],
"-x"
)
==
0
)
{
if
(
strcmp
(
argv
[
2
],
"magisk"
)
==
0
)
return
dump_magisk
(
argv
[
3
],
0755
);
else
if
(
strcmp
(
argv
[
2
],
"manager"
)
==
0
)
return
dump_manager
(
argv
[
3
],
0644
);
}
void
MagiskInit
::
start
()
{
// Prevent file descriptor confusion
mknod
(
"/null"
,
S_IFCHR
|
0666
,
makedev
(
1
,
3
));
int
null
=
open
(
"/null"
,
O_RDWR
|
O_CLOEXEC
);
...
...
@@ -456,155 +584,49 @@ int main(int argc, char *argv[]) {
if
(
null
>
STDERR_FILENO
)
close
(
null
);
// Communicate with kernel using procfs and sysfs
mkdir
(
"/proc"
,
0755
);
xmount
(
"proc"
,
"/proc"
,
"proc"
,
0
,
nullptr
);
mkdir
(
"/sys"
,
0755
);
xmount
(
"sysfs"
,
"/sys"
,
"sysfs"
,
0
,
nullptr
);
struct
cmdline
cmd
{};
parse_cmdline
(
&
cmd
);
// Backup stuffs
full_read
(
"/init"
,
&
self
,
&
self_sz
);
full_read
(
"/.backup/.magisk"
,
&
config
,
&
config_sz
);
/*************
* Initialize
*************/
int
root
,
sbin
;
root
=
open
(
"/"
,
O_RDONLY
|
O_CLOEXEC
);
full_read
(
"/init"
,
&
init
.
buf
,
&
init
.
sz
);
full_read
(
"/.backup/.magisk"
,
&
config
.
buf
,
&
config
.
sz
);
if
(
cmd
.
early_boot
)
{
// Clear rootfs
const
char
*
excl
[]
=
{
"overlay"
,
"proc"
,
"sys"
,
nullptr
};
excl_list
=
excl
;
frm_rf
(
root
);
excl_list
=
nullptr
;
}
else
{
decompress_ramdisk
();
// Revert original init binary
rename
(
"/.backup/init"
,
"/init"
);
rm_rf
(
"/.backup"
);
// Do not go further if device is booting into recovery
if
(
access
(
"/sbin/recovery"
,
F_OK
)
==
0
)
exec_init
(
argv
);
}
/**************
* Early Mount
**************/
struct
device
dev
;
char
partname
[
32
];
char
partfs
[
32
];
if
(
cmd
.
early_boot
)
{
sprintf
(
partname
,
"system%s"
,
cmd
.
slot
);
setup_block
(
&
dev
,
partname
);
xmkdir
(
"/system_root"
,
0755
);
xmount
(
dev
.
path
,
"/system_root"
,
"ext4"
,
MS_RDONLY
,
nullptr
);
xmkdir
(
"/system"
,
0755
);
xmount
(
"/system_root/system"
,
"/system"
,
nullptr
,
MS_BIND
,
nullptr
);
// Copy if these partitions are symlinks
if
(
is_lnk
(
"/system_root/vendor"
))
cp_afc
(
"/system_root/vendor"
,
"/vendor"
);
if
(
is_lnk
(
"/system_root/product"
))
cp_afc
(
"/system_root/product"
,
"/product"
);
if
(
is_lnk
(
"/system_root/odm"
))
cp_afc
(
"/system_root/odm"
,
"/odm"
);
}
else
if
(
read_fstab_dt
(
&
cmd
,
"system"
,
partname
,
partfs
))
{
setup_block
(
&
dev
,
partname
);
xmount
(
dev
.
path
,
"/system"
,
partfs
,
MS_RDONLY
,
nullptr
);
mnt_system
=
true
;
}
if
(
read_fstab_dt
(
&
cmd
,
"vendor"
,
partname
,
partfs
))
{
setup_block
(
&
dev
,
partname
);
xmkdir
(
"/vendor"
,
0755
);
xmount
(
dev
.
path
,
"/vendor"
,
partfs
,
MS_RDONLY
,
nullptr
);
mnt_vendor
=
true
;
}
if
(
read_fstab_dt
(
&
cmd
,
"product"
,
partname
,
partfs
))
{
setup_block
(
&
dev
,
partname
);
xmkdir
(
"/product"
,
0755
);
xmount
(
dev
.
path
,
"/product"
,
partfs
,
MS_RDONLY
,
nullptr
);
mnt_product
=
true
;
}
if
(
read_fstab_dt
(
&
cmd
,
"odm"
,
partname
,
partfs
))
{
setup_block
(
&
dev
,
partname
);
xmkdir
(
"/odm"
,
0755
);
xmount
(
dev
.
path
,
"/odm"
,
partfs
,
MS_RDONLY
,
nullptr
);
mnt_odm
=
true
;
}
load_kernel_info
();
preset
();
early_mount
();
setup_rootfs
();
}
/***************
* Setup Rootfs
***************/
void
MagiskInit
::
test
()
{
cmdline_logging
();
log_cb
.
ex
=
nop_ex
;
bool
patch_init
=
patch_sepolicy
();
chdir
(
argv
[
1
]);
chroot
(
"."
);
chdir
(
"/"
);
if
(
cmd
.
early_boot
)
{
// Clone rootfs except /system
int
system_root
=
open
(
"/system_root"
,
O_RDONLY
|
O_CLOEXEC
);
const
char
*
excl
[]
=
{
"system"
,
nullptr
};
excl_list
=
excl
;
clone_dir
(
system_root
,
root
);
close
(
system_root
);
excl_list
=
nullptr
;
}
load_kernel_info
();
preset
();
early_mount
();
setup_rootfs
();
cleanup
();
}
if
(
patch_init
)
{
constexpr
char
SYSTEM_INIT
[]
=
"/system/bin/init"
;
// If init is symlink, copy it to rootfs so we can patch
struct
stat
st
;
lstat
(
"/init"
,
&
st
);
if
(
S_ISLNK
(
st
.
st_mode
))
cp_afc
(
SYSTEM_INIT
,
"/init"
);
int
main
(
int
argc
,
char
*
argv
[])
{
umask
(
0
);
char
*
addr
;
size_t
size
;
mmap_rw
(
"/init"
,
addr
,
size
);
for
(
char
*
p
=
addr
;
p
<
addr
+
size
;
++
p
)
{
if
(
memcmp
(
p
,
SPLIT_PLAT_CIL
,
sizeof
(
SPLIT_PLAT_CIL
))
==
0
)
{
// Force init to load /sepolicy
memset
(
p
,
'x'
,
sizeof
(
SPLIT_PLAT_CIL
)
-
1
);
p
+=
sizeof
(
SPLIT_PLAT_CIL
)
-
1
;
}
else
if
(
memcmp
(
p
,
SYSTEM_INIT
,
sizeof
(
SYSTEM_INIT
))
==
0
)
{
// Force execute /init instead of /system/bin/init
strcpy
(
p
,
"/init"
);
p
+=
sizeof
(
SYSTEM_INIT
)
-
1
;
}
}
munmap
(
addr
,
size
);
for
(
int
i
=
0
;
init_applet
[
i
];
++
i
)
{
if
(
strcmp
(
basename
(
argv
[
0
]),
init_applet
[
i
])
==
0
)
return
(
*
init_applet_main
[
i
])(
argc
,
argv
);
}
// Handle ramdisk overlays
int
fd
=
open
(
"/overlay"
,
O_RDONLY
|
O_CLOEXEC
);
if
(
fd
>=
0
)
{
mv_dir
(
fd
,
root
);
close
(
fd
);
rmdir
(
"/overlay"
);
if
(
argc
>
1
&&
strcmp
(
argv
[
1
],
"-x"
)
==
0
)
{
if
(
strcmp
(
argv
[
2
],
"magisk"
)
==
0
)
return
dump_magisk
(
argv
[
3
],
0755
);
else
if
(
strcmp
(
argv
[
2
],
"manager"
)
==
0
)
return
dump_manager
(
argv
[
3
],
0644
);
}
setup_init_rc
(
);
MagiskInit
init
(
argv
);
// Don't let init run in init yet
lsetfilecon
(
"/init"
,
"u:object_r:rootfs:s0"
);
// Create hardlink mirror of /sbin to /root
mkdir
(
"/root"
,
0750
);
clone_attr
(
"/sbin"
,
"/root"
);
root
=
xopen
(
"/root"
,
O_RDONLY
|
O_CLOEXEC
);
sbin
=
xopen
(
"/sbin"
,
O_RDONLY
|
O_CLOEXEC
);
link_dir
(
sbin
,
root
);
// Run the main routine
init
.
start
();
// Close all file descriptors
for
(
int
i
=
0
;
i
<
30
;
++
i
)
...
...
@@ -612,7 +634,7 @@ int main(int argc, char *argv[]) {
// Launch daemon to setup overlay
if
(
fork_dont_care
()
==
0
)
setup_overlay
();
init
.
setup_overlay
();
exec_init
(
argv
);
init
.
re_exec_init
(
);
}
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