symtbl: Rename file to match class name

I assume that the preferred style is to leave one major class each to a
file.  In this case, synchronize the names of the Symtbl class and its
containing module.  Per PEP8, the module is lowercase, and the class
remains Pascal case.

If other memory-oriented utilities are introduced in the future, we may
wish to move them, as well as Symtbl, back into a subpackage named
'mem'.

Signed-off-by: Malfurious <m@lfurio.us>
Signed-off-by: dusoleil <howcansocksbereal@gmail.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/sploit/symtbl.py b/sploit/symtbl.py
new file mode 100644
index 0000000..3a3e697
--- /dev/null
+++ b/sploit/symtbl.py
@@ -0,0 +1,53 @@
+import types
+
+class Symtbl:
+    def __init__(self, *, base=0, **kwargs):
+        object.__setattr__(self, '_namesp', types.SimpleNamespace(base=base,sym={},sub={}))
+        for k, v in {**kwargs}.items():
+            setattr(self, k, v)
+
+    def __getattr__(self, ident):
+        self = self._namesp
+        if ident == 'base': return self.base
+        off = self.base + self.sym[ident]
+        if ident in self.sub: return self.sub[ident].map(off)
+        return off
+
+    def __setattr__(self, ident, value):
+        if ident in dir(self): raise Exception(f'Symtbl: assignment would shadow non-symbol "{ident}"')
+        self = self._namesp
+        if ident == 'base':
+            self.base = value
+        else:
+            if type(value) is tuple: self.sub[ident], off = value
+            else: off = value
+            self.sym[ident] = off - self.base
+
+    def map(self, addr, off=0):
+        self = self._namesp
+        mm = Symtbl()
+        mm._namesp.sym, mm._namesp.sub = self.sym, self.sub
+        mm._namesp.base = addr - off
+        return mm
+
+    def adjust(self, off):
+        self = self._namesp
+        for k, v in self.sym.items():
+            self.sym[k] = v + off
+
+    def rebase(self, off):
+        self.adjust(self.base - off)
+
+    def __str__(_self):
+        FMT = '\n{:<20} {:<20}'
+        self = _self._namesp
+
+        s  = f'{len(self.sym)} symbols @ {hex(_self.base)}'
+        s += FMT.format('ADDRESS', 'SYMBOL')
+        for sym, _ in sorted(self.sym.items(), key=lambda x:x[1]):
+            addr = getattr(_self, sym)
+            if type(addr) is Symtbl:
+                s += FMT.format(hex(addr.base), f'[{sym}]')
+            else:
+                s += FMT.format(hex(addr), sym)
+        return s