Description: Add handling for new dnspython arguments
  one_rr_per_rrset and ignore_trailing are present very long ago,
  raise_on_truncation and sock are added since dnspython 2.0.
Author: Felix Yan <felixonmars@archlinux.org>
Date: Tue, 17 Aug 2021 15:42:23 +0800
Origin: https://github.com/eventlet/eventlet/pull/722/commits/4496d99294233383250c0aa38f37b2a0751a346d

---
 eventlet/support/greendns.py | 72 ++++++++++++++++++++++++++++++++----
 1 file changed, 64 insertions(+), 8 deletions(-)

Index: python-eventlet/eventlet/support/greendns.py
===================================================================
--- python-eventlet.orig/eventlet/support/greendns.py
+++ python-eventlet/eventlet/support/greendns.py
@@ -668,8 +668,21 @@ def _net_write(sock, data, expiration):
                 raise dns.exception.Timeout
 
 
+# Test if raise_on_truncation is an argument we should handle.
+# It was newly added in dnspython 2.0
+try:
+    dns.message.from_wire("", raise_on_truncation=True)
+except dns.message.ShortHeader:
+    _handle_raise_on_truncation = True
+except TypeError:
+    # Argument error, there is no argument "raise_on_truncation"
+    _handle_raise_on_truncation = False
+
+
 def udp(q, where, timeout=DNS_QUERY_TIMEOUT, port=53,
-        af=None, source=None, source_port=0, ignore_unexpected=False):
+        af=None, source=None, source_port=0, ignore_unexpected=False,
+        one_rr_per_rrset=False, ignore_trailing=False,
+        raise_on_truncation=False, sock=None):
     """coro friendly replacement for dns.query.udp
     Return the response obtained after sending a query via UDP.
 
@@ -694,7 +707,21 @@ def udp(q, where, timeout=DNS_QUERY_TIME
     @type source_port: int
     @param ignore_unexpected: If True, ignore responses from unexpected
     sources.  The default is False.
-    @type ignore_unexpected: bool"""
+    @type ignore_unexpected: bool
+    @param one_rr_per_rrset: If True, put each RR into its own
+    RRset.
+    @type one_rr_per_rrset: bool
+    @param ignore_trailing: If True, ignore trailing
+    junk at end of the received message.
+    @type ignore_trailing: bool
+    @param raise_on_truncation: If True, raise an exception if
+    the TC bit is set.
+    @type raise_on_truncation: bool
+    @param sock: the socket to use for the
+    query.  If None, the default, a socket is created.  Note that
+    if a socket is provided, it must be a nonblocking datagram socket,
+    and the source and source_port are ignored.
+    @type sock: socket.socket | None"""
 
     wire = q.to_wire()
     if af is None:
@@ -716,7 +743,10 @@ def udp(q, where, timeout=DNS_QUERY_TIME
         if source is not None:
             source = (source, source_port, 0, 0)
 
-    s = socket.socket(af, socket.SOCK_DGRAM)
+    if sock:
+        s = sock
+    else:
+        s = socket.socket(af, socket.SOCK_DGRAM)
     s.settimeout(timeout)
     try:
         expiration = compute_expiration(dns.query, timeout)
@@ -764,14 +794,23 @@ def udp(q, where, timeout=DNS_QUERY_TIME
     finally:
         s.close()
 
-    r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac)
+    if _handle_raise_on_truncation:
+        r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac,
+                                  one_rr_per_rrset=one_rr_per_rrset,
+                                  ignore_trailing=ignore_trailing,
+                                  raise_on_truncation=raise_on_truncation)
+    else:
+        r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac,
+                                  one_rr_per_rrset=one_rr_per_rrset,
+                                  ignore_trailing=ignore_trailing)
     if not q.is_response(r):
         raise dns.query.BadResponse()
     return r
 
 
 def tcp(q, where, timeout=DNS_QUERY_TIMEOUT, port=53,
-        af=None, source=None, source_port=0):
+        af=None, source=None, source_port=0,
+        one_rr_per_rrset=False, ignore_trailing=False, sock=None):
     """coro friendly replacement for dns.query.tcp
     Return the response obtained after sending a query via TCP.
 
@@ -793,7 +832,19 @@ def tcp(q, where, timeout=DNS_QUERY_TIME
     @type source: string
     @param source_port: The port from which to send the message.
     The default is 0.
-    @type source_port: int"""
+    @type source_port: int
+    @type ignore_unexpected: bool
+    @param one_rr_per_rrset: If True, put each RR into its own
+    RRset.
+    @type one_rr_per_rrset: bool
+    @param ignore_trailing: If True, ignore trailing
+    junk at end of the received message.
+    @type ignore_trailing: bool
+    @param sock: the socket to use for the
+    query.  If None, the default, a socket is created.  Note that
+    if a socket is provided, it must be a nonblocking datagram socket,
+    and the source and source_port are ignored.
+    @type sock: socket.socket | None"""
 
     wire = q.to_wire()
     if af is None:
@@ -809,7 +860,10 @@ def tcp(q, where, timeout=DNS_QUERY_TIME
         destination = (where, port, 0, 0)
         if source is not None:
             source = (source, source_port, 0, 0)
-    s = socket.socket(af, socket.SOCK_STREAM)
+    if sock:
+        s = sock
+    else:
+        s = socket.socket(af, socket.SOCK_STREAM)
     s.settimeout(timeout)
     try:
         expiration = compute_expiration(dns.query, timeout)
@@ -837,7 +891,9 @@ def tcp(q, where, timeout=DNS_QUERY_TIME
         wire = bytes(_net_read(s, l, expiration))
     finally:
         s.close()
-    r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac)
+    r = dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac,
+                              one_rr_per_rrset=one_rr_per_rrset,
+                              ignore_trailing=ignore_trailing)
     if not q.is_response(r):
         raise dns.query.BadResponse()
     return r