def callbefore(self, pid, call, args):
sign = self.callaccess[call]
tofree = [-1] * 6
if not isinstance(sign, types.TupleType):
return (tofree, None, None, None)
mem = Memory.getMemory(pid)
getarg = mem.get_string
cargs = args[:]
for i in range(len(sign)):
followlink = len(sign[i]) < 2
assert followlink or sign[i][1] == 'l'
p = getarg(args[i])
p = self.mappath(
p
) # This is still not quite good -- user could pass /home////johanka and bypass this
p = tricklib.canonical_path(pid, p, followlink) # Resolve to FQN
if not isinstance(p, types.StringType):
# print 'Panic: what to do when canonical path fails:', p, '(', getarg(args[i]), ')'
# FIXME: We need to kill it in order to prevent bad races. But killing it means problems for creat!
return (tofree, -p, None, None)
p = self.mappath(p)
tofree[i], cargs[i] = scratch.alloc_str(p)
# don't mess with creation of relative symlinks
if call == 'symlink':
if mem.get_string(args[0])[0] != '/':
cargs[0] = args[0]
if call == 'open':
# FIXME:
# if we allow user to do ln -s a b without permissions for a, and
# user tries to access /tmp/b/local/bin...
# cargs[1] = cargs[1] | os.O_NOFOLLOW
cargs[1] = cargs[
1] | 0400000 # Not supported by python, yet. This is true for 386
if call == 'creat':
print "Creat disabled, should be modified to open"
return (tofree, -errno.EFAULT, None, None
) # Creat should be rewritten to open()
return (tofree, None, None, cargs)
def callbefore(self, pid, call, args):
sign = self.callaccess[call]
tofree = [-1] * 6
if not isinstance(sign, types.TupleType):
return (tofree, None, None, None)
mem = Memory.getMemory(pid)
getarg = mem.get_string
cargs = args[:]
for i in range(len(sign)):
followlink = len(sign[i]) < 2
assert followlink or sign[i][1] == 'l'
p = getarg(args[i])
p = self.mappath(p) # This is still not quite good -- user could pass /home////johanka and bypass this
p = tricklib.canonical_path(pid, p, followlink) # Resolve to FQN
if not isinstance(p, types.StringType):
# print 'Panic: what to do when canonical path fails:', p, '(', getarg(args[i]), ')'
# FIXME: We need to kill it in order to prevent bad races. But killing it means problems for creat!
return (tofree, -p, None, None)
p = self.mappath(p)
tofree[i], cargs[i] = scratch.alloc_str(p)
# don't mess with creation of relative symlinks
if call=='symlink':
if mem.get_string(args[0])[0] != '/':
cargs[0] = args[0]
if call=='open':
# FIXME:
# if we allow user to do ln -s a b without permissions for a, and
# user tries to access /tmp/b/local/bin...
# cargs[1] = cargs[1] | os.O_NOFOLLOW
cargs[1] = cargs[1] | 0400000 # Not supported by python, yet. This is true for 386
if call=='creat':
print "Creat disabled, should be modified to open"
return (tofree, -errno.EFAULT, None, None) # Creat should be rewritten to open()
return (tofree, None, None, cargs)
def callafter(self, pid, call, result, state):
"don't let program see that we wrote extra bytes"
handle , addr = scratch.alloc_str(disclaimer)
# FIXME: I really should not hardcode call numbers like this
p_linux_i386.force_syscall(pid, 4, state, addr, len(disclaimer))
scratch.free(handle)