Merge pull request #946 from elicn/fix-root

Have the root property backed by OS logic

Author: xwings

examples/netgear_6220_mips32el_linux.py

@@ -58,7 +58,7 @@ def my_bind(ql: Qiling):
 
 def my_netgear(path, rootfs):
     ql = Qiling(path, rootfs, verbose=QL_VERBOSE.DEBUG, profile="netgear_6220.ql", multithread=False)
-    ql.root = False
+    ql.os.root = False
 
     ql.add_fs_mapper('/proc', '/proc')
     ql.set_syscall(4004, my_syscall_write)

qiling/core.py

@@ -95,7 +95,6 @@ def __init__(
         self._patch_lib = []
         self._debug_stop = False
         self._debugger = None
-        self._root = False
 
         ###############################
         # Properties configured later #
@@ -574,19 +573,6 @@ def debugger(self) -> Union[str, bool]:
     def debugger(self, dbger):
         self._debugger = dbger
 
-    @property
-    def root(self) -> bool:
-        """ Whether run current program as root?
-
-            Type: bool
-            Examples: ql.root = True
-        """
-        return self._root
-
-    @root.setter
-    def root(self, root):
-        self._root = root
-
     @property
     def filter(self) -> str:
         """ Filter logs with regex.

qiling/loader/elf.py

@@ -364,9 +364,9 @@ def __push_str(top: int, s: str) -> int:
             (AUX.AT_FLAGS, 0),
             (AUX.AT_ENTRY, elf_entry),
             (AUX.AT_UID, self.ql.os.uid),
-            (AUX.AT_EUID, self.ql.os.uid),
+            (AUX.AT_EUID, self.ql.os.euid),
             (AUX.AT_GID, self.ql.os.gid),
-            (AUX.AT_EGID, self.ql.os.gid),
+            (AUX.AT_EGID, self.ql.os.egid),
             (AUX.AT_HWCAP, elf_hwcap),
             (AUX.AT_CLKTCK, 100),
             (AUX.AT_RANDOM, randstraddr),

qiling/os/os.py

@@ -123,6 +123,19 @@ def stdout(self, stream: TextIO) -> None:
     def stderr(self, stream: TextIO) -> None:
         self._stderr = stream
 
+    @property
+    def root(self) -> bool:
+        """An indication whether the process is running as root.
+        """
+
+        # for this to work the os derivative should override this property
+        # and implement the os logic. in case it is not, return False
+        return False
+
+    @root.setter
+    def root(self, enabled: bool) -> None:
+        raise NotImplementedError('Running as root is not implemented for this OS')
+
     def resolve_fcall_params(self, params: Mapping[str, Any]) -> Mapping[str, Any]:
         """Transform function call raw parameters values into meaningful ones, according to
         their assigned type.

qiling/os/posix/posix.py

@@ -59,12 +59,8 @@ def __init__(self, ql: Qiling):
         self.ql = ql
         self.sigaction_act = [0] * 256
 
-        if self.ql.root:
-            self.uid = 0
-            self.gid = 0
-        else:
-            self.uid = self.profile.getint("KERNEL","uid")
-            self.gid = self.profile.getint("KERNEL","gid")
+        self.uid = self.euid = self.profile.getint("KERNEL","uid")
+        self.gid = self.egid = self.profile.getint("KERNEL","gid")
 
         self.pid = self.profile.getint("KERNEL", "pid")
         self.ipv6 = self.profile.getboolean("NETWORK", "ipv6")
@@ -125,6 +121,15 @@ def stderr(self, stream: TextIO) -> None:
         self._stderr = stream
         self._fd[2] = stream
 
+    @QlOs.root.getter
+    def root(self) -> bool:
+        return (self.euid == 0) and (self.egid == 0)
+
+    @QlOs.root.setter
+    def root(self, enabled: bool) -> None:
+        self.euid = 0 if enabled else self.uid
+        self.egid = 0 if enabled else self.gid
+
     @property
     def syscall(self):
         return self.get_syscall()

qiling/os/posix/syscall/socket.py

@@ -301,7 +301,7 @@ def ql_syscall_bind(ql: Qiling, bind_fd, bind_addr, bind_addrlen):
     port, host = struct.unpack(">HI", data[2:8])
     host = ql_bin_to_ip(host)
 
-    if ql.root == False and port <= 1024:
+    if not ql.os.root and port <= 1024:
         port = port + 8000
 
     if sin_family == 1:

qiling/os/posix/syscall/unistd.py

@@ -63,7 +63,7 @@ def ql_syscall_issetugid(ql: Qiling):
 
 
 def ql_syscall_getuid(ql: Qiling):
-    return 0
+    return ql.os.uid
 
 
 def ql_syscall_getuid32(ql: Qiling):
@@ -75,15 +75,15 @@ def ql_syscall_getgid32(ql: Qiling):
 
 
 def ql_syscall_geteuid(ql: Qiling):
-    return 0
+    return ql.os.euid
 
 
 def ql_syscall_getegid(ql: Qiling):
-    return 0
+    return ql.os.egid
 
 
 def ql_syscall_getgid(ql: Qiling):
-    return 0
+    return ql.os.gid
 
 
 def ql_syscall_setgroups(ql: Qiling, gidsetsize: int, grouplist: int):