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()

```

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:

{"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"}]}