def ptr2struct(z, addr, struct_class):
"""
Returns an instance of struct_class read starting from addr
"""
data = z.memory.read(addr, ctypes.sizeof(struct_class))
instance = struct_class()
str2struct(instance, bytes(data))
return instance
def _parse_sockaddr(p, addr, size):
class SOCKADDR(ctypes.Structure):
_fields_ = [
("sa_family", ctypes.c_ushort),
("sa_addr", ctypes.c_char * 14),
]
sockaddr = SOCKADDR()
str2struct(sockaddr, bytes(p.memory.read(addr, size)))
def _parse_sockaddr_in(p, addr, size):
class SOCKADDR_IN(ctypes.Structure):
_fields_ = [
("sin_family", ctypes.c_ushort),
("sin_port", ctypes.c_ushort),
("sin_addr", ctypes.c_uint32),
("sin_zero", ctypes.c_char * 8),
]
sockaddr_in = SOCKADDR_IN()
str2struct(sockaddr_in, bytes(p.memory.read(addr, size)))
def readstruct(self, addr: int, obj: ctypes.Structure) -> ctypes.Structure:
"""
Reads a ctypes structure from memory.
Args:
addr: Address in memory to begin reading structure from.
obj: An instance of the structure to create from memory.
Returns:
Instance of structure read from memory.
"""
data = self.emu.mem_read(addr, ctypes.sizeof(obj))
util.str2struct(obj, data)
return obj
def get_host_and_port(domain, struct_bytes):
host = "255.255.255.255"
port = 65536
if len(struct_bytes) == 0:
return (None, None)
if domain == SocketFamily.AF_INET:
s_in = SOCKADDR_IN()
zelos_util.str2struct(s_in, bytes(struct_bytes))
host = _bytes_to_host(s_in.sin_addr, domain)
port = _bytes_to_port(s_in.sin_port)
elif domain == SocketFamily.AF_INET6:
s_in6 = SOCKADDR_IN6()
zelos_util.str2struct(s_in6, bytes(struct_bytes))
host = _bytes_to_host(s_in6.sin6_addr, domain)
port = _bytes_to_port(s_in6.sin6_port)
return (host, port)
def sys_poll(sm, p):
args = sm.get_args([("struct pollfd *", "fds"), ("nfds_t", "nfds"),
("int", "timeout")])
# parse the file descriptors of interest
sz = ctypes.sizeof(POLLFD())
fds = {}
for i in range(args.nfds):
pollfd = POLLFD()
fd_addr = args.fds + i * sz
pollfd_data = p.memory.read(fd_addr, sz)
str2struct(pollfd, bytes(pollfd_data))
fds[fd_addr] = pollfd
fds_poll = [(v.fd, v.events) for k, v in fds.items()]
e = ", ".join([f"fd={x[0]:x} events={repr(POLL(x[1]))}" for x in fds_poll])
sm.print("polled_fds: " + e)
revents = sm.z.network.select.poll(fds_poll, timeout=0.1)
e = ", ".join([f"fd={x[0]:x} events={repr(POLL(x[1]))}" for x in revents])
sm.print("signaled_fds: " + e)
# commit pollfd struct changes
ready_fds = 0
for i in range(len(fds_poll)):
revent = revents[i][1]
if revent >= 0:
fd_addr = args.fds + i * sz
v = fds[fd_addr]
v.revents = revent
pollfd_data = struct2str(v)
p.memory.write(fd_addr, struct2str(v))
ready_fds += 1
return ready_fds