Greatly optimized subdomain filtering

.gitignore

@@ -1 +1,2 @@
 *.log
+nameservers

filter_subdomains.py

@@ -6,39 +6,67 @@ From a list of subdomains, output only
 the ones resolving to a first-party tracker.
 """
 
+import logging
+import multiprocessing
+import os
 import re
 import sys
+import typing
 
-import dns.resolver
+import coloredlogs
 import dns.exception
+import dns.resolver
 import progressbar
 
 import regexes
 
 DNS_TIMEOUT = 5.0
+MAX_NAMESERVERS = 512
 
-def is_subdomain_matching(subdomain: str) -> bool:
+# TODO Retry failed requests
+
+class DnsResolver(multiprocessing.Process):
+    """
+    Worker process for a DNS resolver.
+    Will resolve DNS to match first-party subdomains.
+    """
+
+    def __init__(self,
+                 in_queue: multiprocessing.Queue,
+                 out_queue: multiprocessing.Queue,
+                 server: str):
+        super(DnsResolver, self).__init__()
+        self.log = logging.getLogger(server)
+
+        self.in_queue = in_queue
+        self.out_queue = out_queue
+
+        self.resolver = dns.resolver.Resolver()
+        self.resolver.nameservers = [server]
+
+    def is_subdomain_matching(self, subdomain: str) -> bool:
         """
         Indicates if the subdomain redirects to a first-party tracker.
         """
         # TODO Look at the whole chain rather than the last one
+        # TODO Also match the ASN of the IP (caching the ASN subnetworks will do)
         try:
-        query = dns.resolver.query(subdomain, 'A', lifetime=DNS_TIMEOUT)
+            query = self.resolver.query(subdomain, 'A', lifetime=DNS_TIMEOUT)
         except dns.resolver.NXDOMAIN:
             return False
         except dns.resolver.NoAnswer:
             return False
         except dns.resolver.YXDOMAIN:
-        print(f"Query name too long for {subdomain}", file=sys.stderr)
+            self.log.warning("Query name too long for %s", subdomain)
             return False
         except dns.resolver.NoNameservers:
-        print(f"All nameservers broken for {subdomain}", file=sys.stderr)
+            self.log.warning("All nameservers broken for %s", subdomain)
             return False
         except dns.exception.Timeout:
-        print(f"Timeout for {subdomain}", file=sys.stderr)
+            self.log.warning("Timeout for %s", subdomain)
             return False
         except dns.name.EmptyLabel:
-        print(f"Empty label for {subdomain}", file=sys.stderr)
+            self.log.warning("Empty label for %s", subdomain)
             return False
         canonical = query.canonical_name.to_text()
         for regex in regexes.REGEXES:
@@ -46,30 +74,94 @@ def is_subdomain_matching(subdomain: str) -> bool:
                 return True
         return False
 
+    def run(self) -> None:
+        self.log.info("Started")
+        for subdomain in iter(self.in_queue.get, None):
+            matching = self.is_subdomain_matching(subdomain)
+            result = (subdomain, matching)
+            # self.log.debug("%s", result)
+            self.out_queue.put(result)
+        self.out_queue.put(None)
+        self.log.info("Stopped")
 
-def is_subdomain_matching_standalone(subdomain: str) -> None:
+
+def get_matching_subdomains(subdomains: typing.Iterable[str],
+                            nameservers: typing.List[str] = None,
+                            ) -> typing.Iterable[typing.Tuple[str, bool]]:
+    subdomains_queue: multiprocessing.Queue = multiprocessing.Queue()
+    results_queue: multiprocessing.Queue = multiprocessing.Queue()
     """
-    Print the subdomain if it redirects to a first-party tracker.
+    Orchestrator of the different DnsResolver threads.
     """
-    subdomain = subdomain.strip()
+
-    if not subdomain:
+    # Use interal resolver by default
-        return
+    servers = nameservers or dns.resolver.Resolver().nameservers
-    if is_subdomain_matching(subdomain):
+    servers = servers[:MAX_NAMESERVERS]
-        print(subdomain)
+
+    # Create workers
+    for server in servers:
+        DnsResolver(subdomains_queue, results_queue, server).start()
+
+    # Send data to workers
+    for subdomain in subdomains:
+        subdomains_queue.put(subdomain)
+
+    # Send sentinel to each worker
+    # sentinel = None ~= EOF
+    for _ in servers:
+        subdomains_queue.put(None)
+    subdomains_queue.close()
+
+    # Wait for one sentinel per worker
+    # In the meantime output results
+    for _ in servers:
+        for result in iter(results_queue.get, None):
+            yield result
+    results_queue.close()
 
 
 if __name__ == '__main__':
+    coloredlogs.install(
+        level='DEBUG',
+        fmt='%(asctime)s %(name)s[%(process)d] %(levelname)s %(message)s'
+    )
+
+    # Progress bar
+    widgets = [
+        progressbar.Percentage(),
+        ' ', progressbar.SimpleProgress(),
+        ' ', progressbar.Bar(),
+        ' ', progressbar.Timer(),
+        ' ', progressbar.AdaptiveTransferSpeed(unit='req'),
+        ' ', progressbar.AdaptiveETA(),
+    ]
+    progress = progressbar.ProgressBar(widgets=widgets)
+
+    # Parsing arguments
     assert len(sys.argv) <= 2
     filename = None
+
     if len(sys.argv) == 2 and sys.argv[1] != '-':
         filename = sys.argv[1]
-        num_lines = sum(1 for line in open(filename))
+        progress.max_value = sum(1 for line in open(filename))
-        iterator = progressbar.progressbar(open(filename), max_value=num_lines)
+        textio = open(filename)
     else:
-        iterator = sys.stdin
+        textio = sys.stdin
 
-    for line in iterator:
+    # Cleaning input
-        is_subdomain_matching_standalone(line)
+    iterator = iter(textio)
+    iterator = map(str.strip, iterator)
+    iterator = filter(None, iterator)
 
-    if filename:
+    # Reading nameservers
-        iterator.close()
+    servers: typing.List[str] = list()
+    if os.path.isfile('nameservers'):
+        servers = open('nameservers').readlines()
+        servers = list(filter(None, map(str.strip, servers)))
+
+    progress.start()
+    for subdomain, matching in get_matching_subdomains(iterator, servers):
+        progress.update(progress.value + 1)
+        if matching:
+            print(subdomain)
+    progress.finish()