collector: fix problems found by fuzzer test

[loctrkd.git] / gps303 / collector.py

diff --git a/gps303/collector.py b/gps303/collector.py
index f4d960eb228d7cb65c5249b90c7bb394160a438f..c2efd79b82182e13319526a644abccb0e85071b9 100644 (file)
--- a/gps303/collector.py
+++ b/gps303/collector.py
@@ -21,6 +21,8 @@ from .zmsg import Bcast, Resp
 
 log = getLogger("gps303/collector")
 
+MAXBUFFER: int = 4096
+
 
 class Client:
     """Connected socket to the terminal plus buffer and metadata"""
@@ -39,7 +41,7 @@ class Client:
     def recv(self) -> Optional[List[Tuple[float, Tuple[str, int], bytes]]]:
         """Read from the socket and parse complete messages"""
         try:
-            segment = self.sock.recv(4096)
+            segment = self.sock.recv(MAXBUFFER)
         except OSError as e:
             log.warning(
                 "Reading from fd %d (IMEI %s): %s",
@@ -57,6 +59,10 @@ class Client:
             return None
         when = time()
         self.buffer += segment
+        if len(self.buffer) > MAXBUFFER:
+            # We are receiving junk. Let's drop it or we run out of memory.
+            log.warning("More than %d unparseable data, dropping", MAXBUFFER)
+            self.buffer = b""
         msgs = []
         while True:
             framestart = self.buffer.find(b"xx")
@@ -64,8 +70,9 @@ class Client:
                 break
             if framestart > 0:  # Should not happen, report
                 log.warning(
-                    'Undecodable data "%s" from fd %d (IMEI %s)',
-                    self.buffer[:framestart].hex(),
+                    'Undecodable data (%d) "%s" from fd %d (IMEI %s)',
+                    framestart,
+                    self.buffer[:framestart][:64].hex(),
                     self.sock.fileno(),
                     self.imei,
                 )
@@ -82,8 +89,10 @@ class Client:
             # Do this embarrassing hack to avoid accidental match
             # of some binary data in the packet against '\r\n'.
             while True:
-                frameend = self.buffer.find(b"\r\n", frameend)
-                if frameend >= (exp_end - 3):  # Found realistic match
+                frameend = self.buffer.find(b"\r\n", frameend + 1)
+                if frameend == -1 or frameend >= (
+                    exp_end - 3
+                ):  # Found realistic match or none
                     break
             if frameend == -1:  # Incomplete frame, return what we have
                 break
@@ -128,7 +137,9 @@ class Clients:
             del self.by_imei[clnt.imei]
         del self.by_fd[fd]
 
-    def recv(self, fd: int) -> Optional[List[Tuple[Optional[str], float, Tuple[str, int], bytes]]]:
+    def recv(
+        self, fd: int
+    ) -> Optional[List[Tuple[Optional[str], float, Tuple[str, int], bytes]]]:
         clnt = self.by_fd[fd]
         msgs = clnt.recv()
         if msgs is None:
@@ -139,7 +150,11 @@ class Clients:
                 if clnt.imei:
                     self.by_imei[clnt.imei] = clnt
                 else:
-                    log.warning("Login message from %s: %s, but client imei unfilled", peeraddr, packet)
+                    log.warning(
+                        "Login message from %s: %s, but client imei unfilled",
+                        peeraddr,
+                        packet,
+                    )
             result.append((clnt.imei, when, peeraddr, packet))
             log.debug(
                 "Received from %s (IMEI %s): %s",
@@ -156,7 +171,7 @@ class Clients:
             log.info("Not connected (IMEI %s)", resp.imei)
 
 
-def runserver(conf: ConfigParser) -> None:
+def runserver(conf: ConfigParser, handle_hibernate: bool = True) -> None:
     # Is this https://github.com/zeromq/pyzmq/issues/1627 still not fixed?!
     zctx = zmq.Context()  # type: ignore
     zpub = zctx.socket(zmq.PUB)  # type: ignore
@@ -209,7 +224,7 @@ def runserver(conf: ConfigParser) -> None:
                                     packet=packet,
                                 ).packed
                             )
-                            if proto == HIBERNATION.PROTO:
+                            if proto == HIBERNATION.PROTO and handle_hibernate:
                                 log.debug(
                                     "HIBERNATION from fd %d (IMEI %s)",
                                     sk,
@@ -243,7 +258,10 @@ def runserver(conf: ConfigParser) -> None:
                 fd = clients.add(clntsock, clntaddr)
                 poller.register(fd, flags=zmq.POLLIN)
     except KeyboardInterrupt:
-        pass
+        zpub.close()
+        zpull.close()
+        zctx.destroy()  # type: ignore
+        tcpl.close()
 
 
 if __name__.endswith("__main__"):