From c344937eec4777e48ea7cfd238a44c9ace7c82cb Mon Sep 17 00:00:00 2001
From: Kiritow <1362050620@qq.com>
Date: Thu, 27 Jan 2022 03:12:58 +0000
Subject: [PATCH] Add MTU patch

---
 generate.py | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/generate.py b/generate.py
index 790dcce..56d2b5c 100644
--- a/generate.py
+++ b/generate.py
@@ -1,8 +1,12 @@
 import os
 import sys
 import time
+import getopt
 
-filepath = sys.argv[1]
+
+opts, args = getopt.getopt(sys.argv[1:], 'k')
+
+filepath = args[0]
 
 path_udp2raw = os.path.join(os.path.dirname(os.path.realpath(sys.argv[0])), 'bin/udp2raw_amd64')
 path_w2u = os.path.join(os.path.dirname(os.path.realpath(sys.argv[0])), 'bin/w2u')
@@ -30,12 +34,16 @@ def add_tmux_session_once():
 for line in content:
     if line.startswith('ListenPort'):
         gen_ctx['wg_port'] = int(line.split('=')[1])
+    if line.startswith('MTU'):
+        gen_ctx['mtu_detected'] = True
     if line.startswith('[Peer]'):
         if 'peer_started' not in gen_ctx:
             gen_ctx['peer_started'] = True
+            if 'mtu_detected' not in gen_ctx:
+                sys.stderr.write('[WARN] MTU not detected, using suggested mtu value (1280).\n')
+                results.append('MTU=1280')
             if gen_ctx['post_down']:
                 results.extend(gen_ctx['post_down'])
-
             if 'has_setup_tmux' in gen_ctx:
                 results.append('PostDown=sleep 1; /usr/bin/tmux kill-session -t tunnel-{}'.format(wg_name))
 
@@ -177,9 +185,12 @@ for line in content:
         else:
             results.insert(last_postup_idx, 'PostUp=ip -4 route add {} dev wg0'.format(route_target))
     else:
-        print('[WARN] comment or unknown hint: {}'.format(line))
+        sys.stderr.write('[WARN] comment or unknown hint: {}\n'.format(line))
 
 
-with open('{}.gen'.format(filename), 'w') as f:
-    f.write('# Generated by wg-ops at {}. DO NOT EDIT\n'.format(time.strftime("%Y-%m-%d %H:%M:%S")))
-    f.write('\n'.join(results))
+final_content = '# Generated by wg-ops at {}. DO NOT EDIT\n{}'.format(time.strftime("%Y-%m-%d %H:%M:%S"), '\n'.join(results))
+if '-k' not in final_content:
+    with open('{}.gen'.format(filename), 'w') as f:
+        f.write(final_content)
+else:
+    print(final_content)