get_url: properly parse filename in content-disposition (#83748)

Since we don't really care about the type we don't have to
query for it and just retrieve the filename value.
Unfortunately we cannot use module_utils.urls.get_response_filename
as we don't have the response object, so just utilize
email.message.Message to parse the filename
instead of manually doing the work ourselves.

Fixes: #83690

changelogs/fragments/83690-get_url-content-disposition-filename.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - get_url - fix honoring ``filename`` from the ``content-disposition`` header even when the type is ``inline`` (https://github.com/ansible/ansible/issues/83690)

lib/ansible/module_utils/urls.py

@@ -340,13 +340,16 @@ def extract_pem_certs(data):
 
 
 def get_response_filename(response):
-    url = response.geturl()
-    path = urlparse(url)[2]
-    filename = os.path.basename(path.rstrip('/')) or None
-    if filename:
-        filename = unquote(filename)
+    if filename := response.headers.get_param('filename', header='content-disposition'):
+        filename = os.path.basename(filename)
+    else:
+        url = response.geturl()
+        path = urlparse(url)[2]
+        filename = os.path.basename(path.rstrip('/')) or None
+        if filename:
+            filename = unquote(filename)
 
-    return response.headers.get_param('filename', header='content-disposition') or filename
+    return filename
 
 
 def parse_content_type(response):

lib/ansible/modules/get_url.py

@@ -367,6 +367,7 @@ url:
     sample: https://www.ansible.com/
 '''
 
+import email.message
 import os
 import re
 import shutil
@@ -439,23 +440,16 @@ def url_get(module, url, dest, use_proxy, last_mod_time, force, timeout=10, head
 
 
 def extract_filename_from_headers(headers):
+    """Extracts a filename from the given dict of HTTP headers.
+
+    Returns the filename if successful, else None.
     """
-    Extracts a filename from the given dict of HTTP headers.
-
-    Looks for the content-disposition header and applies a regex.
-    Returns the filename if successful, else None."""
-    cont_disp_regex = 'attachment; ?filename="?([^"]+)'
-    res = None
-
-    if 'content-disposition' in headers:
-        cont_disp = headers['content-disposition']
-        match = re.match(cont_disp_regex, cont_disp)
-        if match:
-            res = match.group(1)
-            # Try preventing any funny business.
-            res = os.path.basename(res)
-
-    return res
+    msg = email.message.Message()
+    msg['content-disposition'] = headers.get('content-disposition', '')
+    if filename := msg.get_param('filename', header='content-disposition'):
+        # Avoid directory traversal
+        filename = os.path.basename(filename)
+    return filename
 
 
 def is_url(checksum):

test/integration/targets/get_url/tasks/main.yml

@@ -719,3 +719,23 @@
       - result is not changed
       - '"did not match" in result.msg'
       - stat_result_checksum_verify.stat.exists
+
+- name: Test downloading to dir with content-disposition attachment
+  get_url:
+    url: 'https://{{ httpbin_host }}/response-headers?Content-Disposition=attachment%3B%20filename%3D%22filename.json%22'
+    dest: "{{ remote_tmp_dir }}"
+  register: get_dir_filename
+
+- assert:
+    that:
+      - get_dir_filename.dest == remote_tmp_dir ~ "/filename.json"
+
+- name: Test downloading to dir with content-disposition inline
+  get_url:
+    url: 'https://{{ httpbin_host }}/response-headers?Content-Disposition=inline%3B%20filename%3D%22filename.json%22'
+    dest: "{{ remote_tmp_dir }}"
+  register: get_dir_filename
+
+- assert:
+    that:
+      - get_dir_filename.dest == remote_tmp_dir ~ "/filename.json"