Provide internal URL shortening service

Permit users to have very long profile names, and provide
a URL shortening service to bridge the gap for fixed-width
field limitations in DHCP/PXE.

confluent_server/confluent/discovery/protocols/pxe.py

@@ -22,6 +22,7 @@
 
 # option 97 = UUID (wireformat)
 
+import base64
 import confluent.config.configmanager as cfm
 import confluent.collective.manager as collective
 import confluent.noderange as noderange
@@ -35,6 +36,7 @@ import eventlet
 import eventlet.green.socket as socket
 import eventlet.green.select as select
 import netifaces
+import os
 import struct
 import time
 import traceback
@@ -165,6 +167,18 @@ pxearchs = {
 }
 
 
+shorturls = {}
+def register_shorturl(url):
+    urlid = base64.urlsafe_b64encode(os.urandom(3))
+    while urlid in shorturls:
+        urlid = base64.urlsafe_b64encode(os.urandom(3))
+    urlid = urlid.decode()
+    shorturls[urlid] = url
+    returl = '/'.join(url.split('/')[:3])
+    returl += '/confluent-api/boot/su/' + urlid + '/' + os.path.basename(url)
+    return returl
+
+
 uuidmap = {}
 macmap = {}
 attribwatcher = None
@@ -369,12 +383,15 @@ def proxydhcp(handler, nodeguess):
             elif disco['arch'] == 'uefi-aarch64':
                 bootfile = b'confluent/aarch64/ipxe.efi'
             if len(bootfile) > 127:
-                log.log(
-                    {'info': 'Boot offer cannot be made to {0} as the '
-                    'profile name "{1}" is {2} characters longer than is supported '
-                    'for this boot method.'.format(
-                        node, profile, len(bootfile) - 127)})
-                continue
+                if bootfile.startswith(b'http'):
+                    bootfile = register_shorturl(bootfile.decode('utf8')).encode('utf8')
+                else:
+                    log.log(
+                        {'info': 'Boot offer cannot be made to {0} as the '
+                        'profile name "{1}" is {2} characters longer than is supported '
+                        'for this boot method.'.format(
+                            node, profile, len(bootfile) - 127)})
+                    continue
             rpv[:240] = rqv[:240].tobytes()
             rpv[0:1] = b'\x02'
             rpv[108:108 + len(bootfile)] = bootfile
@@ -797,12 +814,15 @@ def reply_dhcp4(node, info, packet, cfg, reqview, httpboot, cfd, profile, sock=N
         if not isinstance(bootfile, bytes):
             bootfile = bootfile.encode('utf8')
         if len(bootfile) > 127:
-            log.log(
-                {'info': 'Boot offer cannot be made to {0} as the '
-                'profile name "{1}" is {2} characters longer than is supported '
-                'for this boot method.'.format(
-                    node, profile, len(bootfile) - 127)})
-            return
+                if bootfile.startswith(b'http'):
+                    bootfile = register_shorturl(bootfile.decode('utf8')).encode('utf8')
+                else:
+                    log.log(
+                        {'info': 'Boot offer cannot be made to {0} as the '
+                        'profile name "{1}" is {2} characters longer than is supported '
+                        'for this boot method.'.format(
+                            node, profile, len(bootfile) - 127)})
+                    return
         repview[108:108 + len(bootfile)] = bootfile
     elif info.get('architecture', None) == 'uefi-aarch64' and packet.get(77, None) == b'iPXE':
         if not profile:

confluent_server/confluent/httpapi.py

@@ -30,6 +30,7 @@ import confluent.config.attributes as attribs
 import confluent.config.configmanager as configmanager
 import confluent.consoleserver as consoleserver
 import confluent.discovery.core as disco
+import confluent.discovery.protocols.pxe as pxe
 import confluent.forwarder as forwarder
 import confluent.exceptions as exc
 import confluent.log as log
@@ -640,6 +641,8 @@ def resourcehandler(env, start_response):
         yield '500 - ' + str(e)
         return
 
+
+
 def resourcehandler_backend(env, start_response):
     """Function to handle new wsgi requests
     """
@@ -648,7 +651,7 @@ def resourcehandler_backend(env, start_response):
                ('Pragma', 'no-cache'),
                ('X-Content-Type-Options', 'nosniff'),
                ('Content-Security-Policy', "default-src 'self'"),
-               ('X-XSS-Protection', '1; mode=block'), ('X-Frame-Options', 'deny'),
+               ('X-XySS-Protection', '1; mode=block'), ('X-Frame-Options', 'deny'),
                ('Strict-Transport-Security', 'max-age=86400'),
                ('X-Permitted-Cross-Domain-Policies', 'none')]
     reqbody = None
@@ -671,6 +674,16 @@ def resourcehandler_backend(env, start_response):
         request = env['PATH_INFO'].split('/')
         if not request[0]:
             request = request[1:]
+        if request[1] == 'su':  # shorturl
+            targurl = pxe.shorturls.get(request[2], None)
+            if not targurl:
+                start_response('404 Not Found', headers)
+                yield ''
+                return
+            headers.append(('Location', targurl))
+            start_response('302 Found', headers)
+            yield ''
+            return
         if len(request) != 4:
             start_response('400 Bad Request', headers)
             yield ''