From d08a36403cb7ff3e4d00a28dbf54e10def6d9e10 Mon Sep 17 00:00:00 2001
From: wangmq <mengqiaowang@yunify.com>
Date: Fri, 25 Dec 2020 16:32:33 +0800
Subject: [PATCH 1/2] Support to control the use of ipv6 or ipv4

---
 qingstor/sdk/config.py  |  1 +
 qingstor/sdk/request.py | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/qingstor/sdk/config.py b/qingstor/sdk/config.py
index 2ffc625..5a670a0 100644
--- a/qingstor/sdk/config.py
+++ b/qingstor/sdk/config.py
@@ -33,6 +33,7 @@
     '# Valid levels are "debug", "info", "warn", "error", and "fatal".\n'
     'log_level: "warn"\n'
     'enable_virtual_host_style: false\n'
+    'enable_dual_stack: false\n'
     'zone: ""\n'
 )
 
diff --git a/qingstor/sdk/request.py b/qingstor/sdk/request.py
index 3dd9e5f..e406a77 100644
--- a/qingstor/sdk/request.py
+++ b/qingstor/sdk/request.py
@@ -23,6 +23,8 @@
 
 from .build import Builder
 from .utils.helper import url_quote
+import requests.packages.urllib3.util.connection as urllib3_cn
+import socket
 
 
 class Request:
@@ -34,6 +36,9 @@ def __init__(self, config, operation):
         self.secret_access_key = config.secret_access_key
         self.logger = logging.getLogger("qingstor-sdk")
         self.enable_virtual_host_style = config.enable_virtual_host_style
+        urllib3_cn.allowed_gai_family = rewrite_allowed_gai_family(
+            config.enable_dual_stack, self.req.headers["Host"]
+        )
 
     def __repr__(self):
         return "<Request %s>" % self.req.method
@@ -176,3 +181,27 @@ def is_sub_resource(self, key):
             "replication", "append", "position", "cname"
         ]
         return key in keys_map
+
+
+def has_ipv6(host):
+    resolves_to_ipv6 = False
+    try:
+        for res in socket.getaddrinfo(host, None, socket.AF_UNSPEC):
+            af, _, _, _, _ = res
+            if af == socket.AF_INET6:
+                resolves_to_ipv6 = True
+    except socket.gaierror:
+        pass
+    return resolves_to_ipv6
+
+
+def rewrite_allowed_gai_family(use_ipv6, host):
+    def allowed_gai_family():
+        family = socket.AF_INET
+        if has_ipv6(host):
+            if use_ipv6:
+                family = socket.AF_INET6
+            else:
+                family = socket.AF_UNSPEC
+        return family
+    return allowed_gai_family

From 639287e0468113f734705a8ea310d4c7e003fd25 Mon Sep 17 00:00:00 2001
From: wangmq <mengqiaowang@yunify.com>
Date: Fri, 25 Dec 2020 17:49:04 +0800
Subject: [PATCH 2/2] Add some notes

---
 qingstor/sdk/request.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/qingstor/sdk/request.py b/qingstor/sdk/request.py
index e406a77..25e66db 100644
--- a/qingstor/sdk/request.py
+++ b/qingstor/sdk/request.py
@@ -184,6 +184,7 @@ def is_sub_resource(self, key):
 
 
 def has_ipv6(host):
+    """ Returns True if the system resolves host to an IPv6 address by default. """
     resolves_to_ipv6 = False
     try:
         for res in socket.getaddrinfo(host, None, socket.AF_UNSPEC):
@@ -196,6 +197,7 @@ def has_ipv6(host):
 
 
 def rewrite_allowed_gai_family(use_ipv6, host):
+    """ This function is designed to control the choice of address family. """
     def allowed_gai_family():
         family = socket.AF_INET
         if has_ipv6(host):