Add functions to get and parse SPF records

.gitignore

@@ -162,3 +162,4 @@ cython_debug/
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
 #.idea/
 
+/.idea/

.idea/pymsgcheck.iml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="PYTHON_MODULE" version="4">
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$">
+      <excludeFolder url="file://$MODULE_DIR$/.venv" />
+    </content>
+    <orderEntry type="jdk" jdkName="Python 3.12 (pymsgcheck)" jdkType="Python SDK" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

pymsgcheck.py

@@ -0,0 +1,36 @@
+from os.path import split
+import dns.resolver
+import ipaddress
+
+
+def parse_spf_parts(part):
+    if part.startswith('ip4:'):
+        return [part[4:]]
+    elif part.startswith('ip6:'):
+        return [part[4:]]
+    elif part.startswith('include'):
+        return get_spf_record(part[8:])
+    elif part.startswith('a'):
+        addresses = []
+        for address in dns.resolver.resolve_name(part[2:]).addresses():
+            addresses.append(address)
+        return addresses
+    else:
+        return []
+
+
+def get_spf_record(domain_name):
+    spf_record = ''
+    servers = []
+    txt_records = dns.resolver.resolve(domain_name, 'TXT')
+    for record in txt_records:
+        if record.to_text().find('v=spf1') > 0:
+            spf_record = record.to_text()
+    parts = spf_record.split()
+    for part in parts:
+        servers += (parse_spf_parts(part))
+    return servers
+
+
+spf_servers = get_spf_record('trivago.com')
+print(spf_servers)