prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  socket.socket doesnt have unrecv. bug in udp server
  https://github.com/Gallopsled/pwntools/blob/5e279e7993f1f57cba2ba128f6bd8a27c19ea25f/pwnlib/tubes/server.py#L120
  
  as mentioned above this is a bug.
  
  line should be
  ```python
  self.unrecv(data)
  ```
  if its necessary at all
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `pwnlib/tubes/server.py`
  Content:
  ```
  1 from __future__ import absolute_import
  2 from __future__ import division
  3 
  4 import errno
  5 import socket
  6 import threading
  7 
  8 from pwnlib.context import context
  9 from pwnlib.log import getLogger
  10 from pwnlib.tubes.sock import sock
  11 from pwnlib.tubes.remote import remote
  12 
  13 log = getLogger(__name__)
  14 
  15 class server(sock):
  16     r"""Creates an TCP or UDP-server to listen for connections. It supports
  17     both IPv4 and IPv6.
  18 
  19     Arguments:
  20         port(int): The port to connect to.
  21             Defaults to a port auto-selected by the operating system.
  22         bindaddr(str): The address to bind to.
  23             Defaults to ``0.0.0.0`` / `::`.
  24         fam: The string "any", "ipv4" or "ipv6" or an integer to pass to :func:`socket.getaddrinfo`.
  25         typ: The string "tcp" or "udp" or an integer to pass to :func:`socket.getaddrinfo`.
  26         callback: A function to be started on incoming connections. It should take a :class:`pwnlib.tubes.remote` as its only argument.
  27 
  28     Examples:
  29 
  30         >>> s = server(8888)
  31         >>> client_conn = remote('localhost', s.lport)
  32         >>> server_conn = s.next_connection()
  33         >>> client_conn.sendline(b'Hello')
  34         >>> server_conn.recvline()
  35         b'Hello\n'
  36         >>> def cb(r):
  37         ...     client_input = r.readline()
  38         ...     r.send(client_input[::-1])
  39         ...
  40         >>> t = server(8889, callback=cb)
  41         >>> client_conn = remote('localhost', t.lport)
  42         >>> client_conn.sendline(b'callback')
  43         >>> client_conn.recv()
  44         b'\nkcabllac'
  45     """
  46 
  47     #: Local port
  48     lport = 0
  49 
  50     #: Local host
  51     lhost = None
  52 
  53     #: Socket type (e.g. socket.SOCK_STREAM)
  54     type = None
  55 
  56     #: Socket family
  57     family = None
  58 
  59     #: Socket protocol
  60     protocol = None
  61 
  62     #: Canonical name of the listening interface
  63     canonname = None
  64 
  65     #: Sockaddr structure that is being listened on
  66     sockaddr = None
  67 
  68     _accepter = None
  69 
  70     def __init__(self, port=0, bindaddr = "0.0.0.0", fam = "any", typ = "tcp",
  71                  callback = None, blocking = False, *args, **kwargs):
  72         super(server, self).__init__(*args, **kwargs)
  73 
  74         port = int(port)
  75         fam  = {socket.AF_INET: 'ipv4',
  76                 socket.AF_INET6: 'ipv6'}.get(fam, fam)
  77 
  78         fam = self._get_family(fam)
  79         typ = self._get_type(typ)
  80 
  81         if fam == socket.AF_INET6 and bindaddr == '0.0.0.0':
  82             bindaddr = '::'
  83 
  84         h = self.waitfor('Trying to bind to %s on port %d' % (bindaddr, port))
  85 
  86         for res in socket.getaddrinfo(bindaddr, port, fam, typ, 0, socket.AI_PASSIVE):
  87             self.family, self.type, self.proto, self.canonname, self.sockaddr = res
  88 
  89             if self.type not in [socket.SOCK_STREAM, socket.SOCK_DGRAM]:
  90                 continue
  91 
  92             h.status("Trying %s" % self.sockaddr[0])
  93             listen_sock = socket.socket(self.family, self.type, self.proto)
  94             listen_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
  95             listen_sock.bind(self.sockaddr)
  96             self.lhost, self.lport = listen_sock.getsockname()[:2]
  97             if self.type == socket.SOCK_STREAM:
  98                 listen_sock.listen(1)
  99             break
  100         else:
  101             h.failure()
  102             self.error("Could not bind to %s on port %d" % (bindaddr, port))
  103 
  104         h.success()
  105 
  106         self.sock = listen_sock
  107         self.connections_waiting = threading.Event()
  108         self.connections = []
  109         def accepter():
  110             while True:
  111                 h = self.waitfor('Waiting for connections on %s:%s' % (self.lhost, self.lport))
  112                 while True:
  113                     try:
  114                         if self.type == socket.SOCK_STREAM:
  115                             sock, rhost = listen_sock.accept()
  116                         else:
  117                             data, rhost = listen_sock.recvfrom(4096)
  118                             listen_sock.connect(rhost)
  119                             sock = listen_sock
  120                             sock.unrecv(data)
  121                         sock.settimeout(self.timeout)
  122                         break
  123                     except socket.error as e:
  124                         if e.errno == errno.EINTR:
  125                             continue
  126                         h.failure()
  127                         self.exception("Socket failure while waiting for connection")
  128                         sock = None
  129                         return
  130 
  131                 self.rhost, self.rport = rhost[:2]
  132                 r = remote(self.rhost, self.rport, sock = sock)
  133                 h.success('Got connection from %s on port %d' % (self.rhost, self.rport))
  134                 if callback:
  135                     if not blocking:
  136                         t = context.Thread(target = callback, args = (r,))
  137                         t.daemon = True
  138                         t.start()
  139                     else:
  140                         callback(r)
  141                 else:
  142                     self.connections.append(r)
  143                     if not self.connections_waiting.is_set():
  144                         self.connections_waiting.set()
  145 
  146         self._accepter = context.Thread(target = accepter)
  147         self._accepter.daemon = True
  148         self._accepter.start()
  149 
  150     def next_connection(self):
  151         if not self.connections_waiting.is_set():
  152             self.connections_waiting.wait()
  153         conn = self.connections.pop(0)
  154         if not self.connections:
  155             self.connections_waiting.clear()
  156         return conn
  157 
  158     def close(self):
  159         # since `close` is scheduled to run on exit we must check that we got
  160         # a connection or the program will hang in the `join` call above
  161         if self._accepter and self._accepter.is_alive():
  162             return
  163         super(server, self).close()
  164
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/pwnlib/tubes/server.py b/pwnlib/tubes/server.py
  --- a/pwnlib/tubes/server.py
  +++ b/pwnlib/tubes/server.py
  @@ -117,7 +117,7 @@
                               data, rhost = listen_sock.recvfrom(4096)
                               listen_sock.connect(rhost)
                               sock = listen_sock
  -                            sock.unrecv(data)
  +                            self.unrecv(data)
                           sock.settimeout(self.timeout)
                           break
                       except socket.error as e:
  
verification_info: {"golden_diff": "diff --git a/pwnlib/tubes/server.py b/pwnlib/tubes/server.py\n--- a/pwnlib/tubes/server.py\n+++ b/pwnlib/tubes/server.py\n@@ -117,7 +117,7 @@\n                             data, rhost = listen_sock.recvfrom(4096)\n                             listen_sock.connect(rhost)\n                             sock = listen_sock\n-                            sock.unrecv(data)\n+                            self.unrecv(data)\n                         sock.settimeout(self.timeout)\n                         break\n                     except socket.error as e:\n", "issue": "socket.socket doesnt have unrecv. bug in udp server\nhttps://github.com/Gallopsled/pwntools/blob/5e279e7993f1f57cba2ba128f6bd8a27c19ea25f/pwnlib/tubes/server.py#L120\r\n\r\nas mentioned above this is a bug.\r\n\r\nline should be\r\n```python\r\nself.unrecv(data)\r\n```\r\nif its necessary at all\n", "before_files": [{"content": "from __future__ import absolute_import\nfrom __future__ import division\n\nimport errno\nimport socket\nimport threading\n\nfrom pwnlib.context import context\nfrom pwnlib.log import getLogger\nfrom pwnlib.tubes.sock import sock\nfrom pwnlib.tubes.remote import remote\n\nlog = getLogger(__name__)\n\nclass server(sock):\n    r\"\"\"Creates an TCP or UDP-server to listen for connections. It supports\n    both IPv4 and IPv6.\n\n    Arguments:\n        port(int): The port to connect to.\n            Defaults to a port auto-selected by the operating system.\n        bindaddr(str): The address to bind to.\n            Defaults to ``0.0.0.0`` / `::`.\n        fam: The string \"any\", \"ipv4\" or \"ipv6\" or an integer to pass to :func:`socket.getaddrinfo`.\n        typ: The string \"tcp\" or \"udp\" or an integer to pass to :func:`socket.getaddrinfo`.\n        callback: A function to be started on incoming connections. It should take a :class:`pwnlib.tubes.remote` as its only argument.\n\n    Examples:\n\n        >>> s = server(8888)\n        >>> client_conn = remote('localhost', s.lport)\n        >>> server_conn = s.next_connection()\n        >>> client_conn.sendline(b'Hello')\n        >>> server_conn.recvline()\n        b'Hello\\n'\n        >>> def cb(r):\n        ...     client_input = r.readline()\n        ...     r.send(client_input[::-1])\n        ...\n        >>> t = server(8889, callback=cb)\n        >>> client_conn = remote('localhost', t.lport)\n        >>> client_conn.sendline(b'callback')\n        >>> client_conn.recv()\n        b'\\nkcabllac'\n    \"\"\"\n\n    #: Local port\n    lport = 0\n\n    #: Local host\n    lhost = None\n\n    #: Socket type (e.g. socket.SOCK_STREAM)\n    type = None\n\n    #: Socket family\n    family = None\n\n    #: Socket protocol\n    protocol = None\n\n    #: Canonical name of the listening interface\n    canonname = None\n\n    #: Sockaddr structure that is being listened on\n    sockaddr = None\n\n    _accepter = None\n\n    def __init__(self, port=0, bindaddr = \"0.0.0.0\", fam = \"any\", typ = \"tcp\",\n                 callback = None, blocking = False, *args, **kwargs):\n        super(server, self).__init__(*args, **kwargs)\n\n        port = int(port)\n        fam  = {socket.AF_INET: 'ipv4',\n                socket.AF_INET6: 'ipv6'}.get(fam, fam)\n\n        fam = self._get_family(fam)\n        typ = self._get_type(typ)\n\n        if fam == socket.AF_INET6 and bindaddr == '0.0.0.0':\n            bindaddr = '::'\n\n        h = self.waitfor('Trying to bind to %s on port %d' % (bindaddr, port))\n\n        for res in socket.getaddrinfo(bindaddr, port, fam, typ, 0, socket.AI_PASSIVE):\n            self.family, self.type, self.proto, self.canonname, self.sockaddr = res\n\n            if self.type not in [socket.SOCK_STREAM, socket.SOCK_DGRAM]:\n                continue\n\n            h.status(\"Trying %s\" % self.sockaddr[0])\n            listen_sock = socket.socket(self.family, self.type, self.proto)\n            listen_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)\n            listen_sock.bind(self.sockaddr)\n            self.lhost, self.lport = listen_sock.getsockname()[:2]\n            if self.type == socket.SOCK_STREAM:\n                listen_sock.listen(1)\n            break\n        else:\n            h.failure()\n            self.error(\"Could not bind to %s on port %d\" % (bindaddr, port))\n\n        h.success()\n\n        self.sock = listen_sock\n        self.connections_waiting = threading.Event()\n        self.connections = []\n        def accepter():\n            while True:\n                h = self.waitfor('Waiting for connections on %s:%s' % (self.lhost, self.lport))\n                while True:\n                    try:\n                        if self.type == socket.SOCK_STREAM:\n                            sock, rhost = listen_sock.accept()\n                        else:\n                            data, rhost = listen_sock.recvfrom(4096)\n                            listen_sock.connect(rhost)\n                            sock = listen_sock\n                            sock.unrecv(data)\n                        sock.settimeout(self.timeout)\n                        break\n                    except socket.error as e:\n                        if e.errno == errno.EINTR:\n                            continue\n                        h.failure()\n                        self.exception(\"Socket failure while waiting for connection\")\n                        sock = None\n                        return\n\n                self.rhost, self.rport = rhost[:2]\n                r = remote(self.rhost, self.rport, sock = sock)\n                h.success('Got connection from %s on port %d' % (self.rhost, self.rport))\n                if callback:\n                    if not blocking:\n                        t = context.Thread(target = callback, args = (r,))\n                        t.daemon = True\n                        t.start()\n                    else:\n                        callback(r)\n                else:\n                    self.connections.append(r)\n                    if not self.connections_waiting.is_set():\n                        self.connections_waiting.set()\n\n        self._accepter = context.Thread(target = accepter)\n        self._accepter.daemon = True\n        self._accepter.start()\n\n    def next_connection(self):\n        if not self.connections_waiting.is_set():\n            self.connections_waiting.wait()\n        conn = self.connections.pop(0)\n        if not self.connections:\n            self.connections_waiting.clear()\n        return conn\n\n    def close(self):\n        # since `close` is scheduled to run on exit we must check that we got\n        # a connection or the program will hang in the `join` call above\n        if self._accepter and self._accepter.is_alive():\n            return\n        super(server, self).close()\n", "path": "pwnlib/tubes/server.py"}], "after_files": [{"content": "from __future__ import absolute_import\nfrom __future__ import division\n\nimport errno\nimport socket\nimport threading\n\nfrom pwnlib.context import context\nfrom pwnlib.log import getLogger\nfrom pwnlib.tubes.sock import sock\nfrom pwnlib.tubes.remote import remote\n\nlog = getLogger(__name__)\n\nclass server(sock):\n    r\"\"\"Creates an TCP or UDP-server to listen for connections. It supports\n    both IPv4 and IPv6.\n\n    Arguments:\n        port(int): The port to connect to.\n            Defaults to a port auto-selected by the operating system.\n        bindaddr(str): The address to bind to.\n            Defaults to ``0.0.0.0`` / `::`.\n        fam: The string \"any\", \"ipv4\" or \"ipv6\" or an integer to pass to :func:`socket.getaddrinfo`.\n        typ: The string \"tcp\" or \"udp\" or an integer to pass to :func:`socket.getaddrinfo`.\n        callback: A function to be started on incoming connections. It should take a :class:`pwnlib.tubes.remote` as its only argument.\n\n    Examples:\n\n        >>> s = server(8888)\n        >>> client_conn = remote('localhost', s.lport)\n        >>> server_conn = s.next_connection()\n        >>> client_conn.sendline(b'Hello')\n        >>> server_conn.recvline()\n        b'Hello\\n'\n        >>> def cb(r):\n        ...     client_input = r.readline()\n        ...     r.send(client_input[::-1])\n        ...\n        >>> t = server(8889, callback=cb)\n        >>> client_conn = remote('localhost', t.lport)\n        >>> client_conn.sendline(b'callback')\n        >>> client_conn.recv()\n        b'\\nkcabllac'\n    \"\"\"\n\n    #: Local port\n    lport = 0\n\n    #: Local host\n    lhost = None\n\n    #: Socket type (e.g. socket.SOCK_STREAM)\n    type = None\n\n    #: Socket family\n    family = None\n\n    #: Socket protocol\n    protocol = None\n\n    #: Canonical name of the listening interface\n    canonname = None\n\n    #: Sockaddr structure that is being listened on\n    sockaddr = None\n\n    _accepter = None\n\n    def __init__(self, port=0, bindaddr = \"0.0.0.0\", fam = \"any\", typ = \"tcp\",\n                 callback = None, blocking = False, *args, **kwargs):\n        super(server, self).__init__(*args, **kwargs)\n\n        port = int(port)\n        fam  = {socket.AF_INET: 'ipv4',\n                socket.AF_INET6: 'ipv6'}.get(fam, fam)\n\n        fam = self._get_family(fam)\n        typ = self._get_type(typ)\n\n        if fam == socket.AF_INET6 and bindaddr == '0.0.0.0':\n            bindaddr = '::'\n\n        h = self.waitfor('Trying to bind to %s on port %d' % (bindaddr, port))\n\n        for res in socket.getaddrinfo(bindaddr, port, fam, typ, 0, socket.AI_PASSIVE):\n            self.family, self.type, self.proto, self.canonname, self.sockaddr = res\n\n            if self.type not in [socket.SOCK_STREAM, socket.SOCK_DGRAM]:\n                continue\n\n            h.status(\"Trying %s\" % self.sockaddr[0])\n            listen_sock = socket.socket(self.family, self.type, self.proto)\n            listen_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)\n            listen_sock.bind(self.sockaddr)\n            self.lhost, self.lport = listen_sock.getsockname()[:2]\n            if self.type == socket.SOCK_STREAM:\n                listen_sock.listen(1)\n            break\n        else:\n            h.failure()\n            self.error(\"Could not bind to %s on port %d\" % (bindaddr, port))\n\n        h.success()\n\n        self.sock = listen_sock\n        self.connections_waiting = threading.Event()\n        self.connections = []\n        def accepter():\n            while True:\n                h = self.waitfor('Waiting for connections on %s:%s' % (self.lhost, self.lport))\n                while True:\n                    try:\n                        if self.type == socket.SOCK_STREAM:\n                            sock, rhost = listen_sock.accept()\n                        else:\n                            data, rhost = listen_sock.recvfrom(4096)\n                            listen_sock.connect(rhost)\n                            sock = listen_sock\n                            self.unrecv(data)\n                        sock.settimeout(self.timeout)\n                        break\n                    except socket.error as e:\n                        if e.errno == errno.EINTR:\n                            continue\n                        h.failure()\n                        self.exception(\"Socket failure while waiting for connection\")\n                        sock = None\n                        return\n\n                self.rhost, self.rport = rhost[:2]\n                r = remote(self.rhost, self.rport, sock = sock)\n                h.success('Got connection from %s on port %d' % (self.rhost, self.rport))\n                if callback:\n                    if not blocking:\n                        t = context.Thread(target = callback, args = (r,))\n                        t.daemon = True\n                        t.start()\n                    else:\n                        callback(r)\n                else:\n                    self.connections.append(r)\n                    if not self.connections_waiting.is_set():\n                        self.connections_waiting.set()\n\n        self._accepter = context.Thread(target = accepter)\n        self._accepter.daemon = True\n        self._accepter.start()\n\n    def next_connection(self):\n        if not self.connections_waiting.is_set():\n            self.connections_waiting.wait()\n        conn = self.connections.pop(0)\n        if not self.connections:\n            self.connections_waiting.clear()\n        return conn\n\n    def close(self):\n        # since `close` is scheduled to run on exit we must check that we got\n        # a connection or the program will hang in the `join` call above\n        if self._accepter and self._accepter.is_alive():\n            return\n        super(server, self).close()\n", "path": "pwnlib/tubes/server.py"}]}