async def move_fds(self,
fds: t.List[FileDescriptor]) -> t.List[FileDescriptor]:
"Move the passed-in file descriptors from self.access_task to self.task"
if self.access_task.fd_table == self.task.fd_table:
return [fd.move(self.task) for fd in fds]
iovec = await self.access_task.ptr(
IovecList([await self.access_task.malloc(bytes, 1)]))
cmsgs = await self.access_task.ptr(
CmsgList([CmsgSCMRights([fd for fd in fds])]))
_, [] = await self.access_fd.sendmsg(await self.access_task.ptr(
SendMsghdr(None, iovec, cmsgs)))
iovec = await self.task.ptr(
IovecList([await self.task.malloc(bytes, 1)]))
cmsgs = await self.task.ptr(
CmsgList([CmsgSCMRights([fd for fd in fds])]))
_, [], hdr = await self.fd.recvmsg(await self.task.ptr(
RecvMsghdr(None, iovec, cmsgs)))
cmsgs_ptr = (await hdr.read()).control
if cmsgs_ptr is None:
raise Exception("cmsgs field of header is, impossibly, None")
[cmsg] = await cmsgs_ptr.read()
if not isinstance(cmsg, CmsgSCMRights):
raise Exception("expected SCM_RIGHTS cmsg, instead got", cmsg)
passed_socks = cmsg
for sock in fds:
await sock.close()
return passed_socks
async def _connect_and_send(
self: PersistentProcess, process: Process,
syscall_sock: FileDescriptor, data_sock: FileDescriptor,
) -> t.Tuple[FileDescriptor, FileDescriptor]:
"""Connect to a persistent process's socket, send some file descriptors
"""
fds = [syscall_sock, data_sock]
sock = await process.make_afd(await process.socket(AF.UNIX, SOCK.STREAM|SOCK.NONBLOCK))
sockaddr_un = await SockaddrUn.from_path(process, self.persistent_path)
addr = await process.ptr(sockaddr_un)
count = await process.ptr(Int32(len(fds)))
iovec = await process.ptr(IovecList([await process.malloc(bytes, 1)]))
cmsgs = await process.ptr(CmsgList([CmsgSCMRights(fds)]))
hdr = await process.ptr(SendMsghdr(None, iovec, cmsgs))
response: Pointer = await process.ptr(StructList(Int32, [Int32(0)]*len(fds)))
data = None
await sock.connect(addr)
_, _ = await sock.write(count)
_, [] = await sock.handle.sendmsg(hdr, SendmsgFlags.NONE)
while response.size() > 0:
valid, response = await sock.read(response)
data += valid
remote_syscall_sock, remote_data_sock = [self.task.make_fd_handle(near.FileDescriptor(int(i)))
for i in ((await data.read()).elems if data else [])]
await sock.close()
return remote_syscall_sock, remote_data_sock
async def sendmsg_op(sem: RAM) -> WrittenPointer[SendMsghdr]:
iovec = await sem.ptr(IovecList([await sem.malloc(bytes, 1)]))
cmsgs = await sem.ptr(
CmsgList([
CmsgSCMRights(
[passed_syscall_sock, passed_data_sock, connection_fd])
]))
return await sem.ptr(SendMsghdr(None, iovec, cmsgs))
async def sendmsg_op(
sem: RAM
) -> t.Tuple[WrittenPointer[SockaddrUn], WrittenPointer[Int32],
WrittenPointer[SendMsghdr], Pointer[StructList[Int32]]]:
addr = await sem.ptr(sockaddr_un)
count = await sem.ptr(Int32(len(fds)))
iovec = await sem.ptr(IovecList([await sem.malloc(bytes, 1)]))
cmsgs = await sem.ptr(CmsgList([CmsgSCMRights(fds)]))
hdr = await sem.ptr(SendMsghdr(None, iovec, cmsgs))
response_buf = await sem.ptr(StructList(Int32, [Int32(0)] * len(fds)))
return addr, count, hdr, response_buf
async def recvmsg_op(sem: RAM) -> WrittenPointer[RecvMsghdr]:
iovec = await sem.ptr(IovecList([await sem.malloc(bytes, 1)]))
cmsgs = await sem.ptr(CmsgList([CmsgSCMRights([fd
for fd in fds])]))
return await sem.ptr(RecvMsghdr(None, iovec, cmsgs))
async def stdin_bootstrap(
parent: Process,
bootstrap_command: Command,
) -> t.Tuple[AsyncChildPid, Process]:
"""Create a process from running an arbitrary command which must run rsyscall-stdin-bootstrap
bootstrap_command can be any arbitrary command, but it must eventually exec
rsyscall-stdin-bootstrap, and pass down stdin when it does.
We'll clone and exec bootstrap_command, passing down a socketpair for stdin, and try to
bootstrap over the other end of the socketpair. Once rsyscall-stdin-bootstrap starts,
it will respond to our bootstrap and we'll create a new process.
"""
#### clone and exec into the bootstrap command
# create the socketpair that will be used as stdin
stdin_pair = await (await parent.task.socketpair(
AF.UNIX, SOCK.STREAM, 0, await parent.task.malloc(Socketpair))).read()
parent_sock = stdin_pair.first
child = await parent.fork()
# set up stdin with socketpair
await child.task.inherit_fd(stdin_pair.second).dup2(child.stdin)
await stdin_pair.second.close()
# exec
child_pid = await child.exec(bootstrap_command)
#### set up all the fds we'll want to pass over
# the basic connections
[(access_syscall_sock, passed_syscall_sock),
(access_data_sock, passed_data_sock)
] = await parent.open_async_channels(2)
# send the fds to the new process
connection_fd, make_connection = await parent.connection.prep_fd_transfer()
iovec = await parent.ptr(IovecList([await parent.malloc(bytes, 1)]))
cmsgs = await parent.ptr(
CmsgList([
CmsgSCMRights(
[passed_syscall_sock, passed_data_sock, connection_fd])
]))
_, [] = await parent_sock.sendmsg(
await parent.ptr(SendMsghdr(None, iovec, cmsgs)), SendmsgFlags.NONE)
# close our reference to fds that only the new process needs
await passed_syscall_sock.close()
await passed_data_sock.close()
# close the socketpair
await parent_sock.close()
#### read describe to get all the information we need from the new process
describe_buf = AsyncReadBuffer(access_data_sock)
describe_struct = await describe_buf.read_cffi(
'struct rsyscall_stdin_bootstrap')
environ = await describe_buf.read_envp(describe_struct.envp_count)
#### build the new task
pid = describe_struct.pid
fd_table = handle.FDTable(pid)
address_space = far.AddressSpace(pid)
# we assume pid namespace is shared
# TODO include namespace inode numbers numbers in describe
# note: if we start dealing with namespace numbers then we need to
# have a Kernel namespace which tells us which kernel we get those
# numbers from.
# oh hey we can conveniently dump the inode numbers with getdents!
pidns = parent.task.pidns
# we assume mount namespace is not shared (can't hurt)
mountns = far.MountNamespace(pid)
pid = near.Pid(pid)
base_task = Task(pid, fd_table, address_space, pidns, mountns)
remote_syscall_fd = base_task.make_fd_handle(
near.FileDescriptor(describe_struct.syscall_fd))
base_task.sysif = SyscallConnection(
logger.getChild(str(pid)),
access_syscall_sock,
remote_syscall_fd,
)
base_task.allocator = await memory.AllocatorClient.make_allocator(base_task
)
# we assume our SignalMask is zero'd before being started, so we don't inherit it
# TODO I think I can maybe elide creating this epollcenter and instead inherit it or share it, maybe?
epoller = await Epoller.make_root(base_task)
child_monitor = await ChildPidMonitor.make(base_task, epoller)
connection = make_connection(
base_task,
base_task.make_fd_handle(
near.FileDescriptor(describe_struct.connecting_fd)))
new_parent = Process(
task=base_task,
connection=connection,
loader=NativeLoader.make_from_symbols(base_task,
describe_struct.symbols),
epoller=epoller,
child_monitor=child_monitor,
environ=Environment.make_from_environ(base_task, environ),
stdin=base_task.make_fd_handle(near.FileDescriptor(0)),
stdout=base_task.make_fd_handle(near.FileDescriptor(1)),
stderr=base_task.make_fd_handle(near.FileDescriptor(2)),
)
return child_pid, new_parent
async def _setup_stub(
process: Process,
bootstrap_sock: FileDescriptor,
) -> t.Tuple[t.List[str], Process]:
"Setup a stub process"
[(access_syscall_sock, passed_syscall_sock),
(access_data_sock, passed_data_sock)
] = await process.open_async_channels(2)
# memfd for setting up the futex
futex_memfd = await process.task.memfd_create(await process.task.ptr(
Path("child_robust_futex_list")))
# send the fds to the new process
connection_fd, make_connection = await process.connection.prep_fd_transfer(
)
iovec = await process.ptr(IovecList([await process.malloc(bytes, 1)]))
cmsgs = await process.ptr(
CmsgList([
CmsgSCMRights([
passed_syscall_sock, passed_data_sock, futex_memfd,
connection_fd
])
]))
_, [] = await bootstrap_sock.sendmsg(
await process.ptr(SendMsghdr(None, iovec, cmsgs)), SendmsgFlags.NONE)
# close our reference to fds that only the new process needs
await passed_syscall_sock.invalidate()
await passed_data_sock.invalidate()
# close the socketpair
await bootstrap_sock.invalidate()
#### read describe to get all the information we need from the new process
describe_buf = AsyncReadBuffer(access_data_sock)
describe_struct = await describe_buf.read_cffi('struct rsyscall_unix_stub')
argv_raw = await describe_buf.read_length_prefixed_array(
describe_struct.argc)
argv = [os.fsdecode(arg) for arg in argv_raw]
environ = await describe_buf.read_envp(describe_struct.envp_count)
#### build the new task
pid = describe_struct.pid
fd_table = handle.FDTable(pid)
address_space = far.AddressSpace(pid)
# we assume pid namespace is shared
pidns = process.task.pidns
# we assume mount namespace is not shared (won't hurt)
mountns = far.MountNamespace(pid)
pid = near.Pid(pid)
# we assume net namespace is shared - that's dubious...
# we should make it possible to control the namespace sharing more, hmm.
# TODO maybe the describe should contain the net namespace number? and we can store our own as well?
# then we can automatically do it right
base_task = Task(pid, fd_table, address_space, pidns, mountns)
remote_syscall_fd = base_task.make_fd_handle(
near.FileDescriptor(describe_struct.syscall_fd))
base_task.sysif = SyscallConnection(
logger.getChild(str(pid)),
access_syscall_sock,
remote_syscall_fd,
)
base_task.allocator = await memory.AllocatorClient.make_allocator(base_task
)
base_task.sigmask = Sigset(
{SIG(bit)
for bit in rsyscall.struct.bits(describe_struct.sigmask)})
# TODO I think I can maybe elide creating this epollcenter and instead inherit it or share it, maybe?
# I guess I need to write out the set too in describe
epoller = await Epoller.make_root(base_task)
child_monitor = await ChildPidMonitor.make(base_task, epoller)
connection = make_connection(
base_task,
base_task.make_fd_handle(
near.FileDescriptor(describe_struct.connecting_fd)))
new_process = Process(
task=base_task,
connection=connection,
loader=NativeLoader.make_from_symbols(base_task,
describe_struct.symbols),
epoller=epoller,
child_monitor=child_monitor,
environ=Environment.make_from_environ(base_task, environ),
stdin=base_task.make_fd_handle(near.FileDescriptor(0)),
stdout=base_task.make_fd_handle(near.FileDescriptor(1)),
stderr=base_task.make_fd_handle(near.FileDescriptor(2)),
)
#### TODO set up futex I guess
remote_futex_memfd = near.FileDescriptor(describe_struct.futex_memfd)
return argv, new_process