RouterInfo properties parser

pyseeder/routerinfo.py

@@ -0,0 +1,59 @@
+class RouterInfo:
+    
+    def __init__(self, filename):
+        with open(filename, 'rb') as f:
+            buf = f.read()
+            if len(buf) < 391: # TODO: parse identity
+                return 
+            offset = 391
+            self.timestamp = int.from_bytes(buf[offset: offset + 8], byteorder='big') # 8 bytes timestamp
+            offset += 8
+            offset += self.readaddresses(buf[offset:]) # addresses
+            offset += buf[offset]*32 + 1; # peers  
+            self.properties = {}
+            offset += self.readproperties(buf[offset:]) # properties
+
+    def readaddresses(self, buf):
+        numaddresses = buf[0]
+        offset = 1
+        for i in range(0, numaddresses):
+            offset += 1 # cost
+            offset += 8 # date
+            offset += len(self.readstring(buf[offset:])) + 1 # style string
+            size = int.from_bytes(buf[offset:offset+2], byteorder='big') # properties
+            offset += size + 2
+        return offset
+    
+    def readproperties(self, buf):
+        size = int.from_bytes(buf[0:2], byteorder='big')
+        r = 2
+        while r < size + 2:
+            key = self.readstring(buf[r:])
+            r += len(key) + 2 # length and =
+            value = self.readstring(buf[r:])
+            r += len(value) + 2 # length and ;
+            self.properties[key] = value
+        return size
+
+    def readstring(self, buf):
+        l = buf[0]
+        return buf[1:l+1].decode('utf-8')
+
+    def getversion(self):
+        if 'router.version' in self.properties:
+            v = 0
+            for c in self.properties['router.version']:
+                if c >= '0' and c <= '9':
+                    v *= 10
+                    v += (ord(c) - ord('0'))
+            return v
+        else:
+            return 0
+
+    def hasinvalidcaps(self):
+        invalidcaps = set('UDEG')
+        return any((c in invalidcaps) for c in self.properties['caps'])
+
+    def isvalid(self):
+        return self.getversion() >= 959 and not self.hasinvalidcaps() # version >= 0.9.59 and no 'U', 'D', 'E' or 'G' caps
+