flag to control mtp timeout kill behavior

bin/mtag/very-bad-idea.py

@@ -16,7 +16,7 @@ goes without saying, but this is HELLA DANGEROUS,
   GIVES RCE TO ANYONE WHO HAVE UPLOAD PERMISSIONS
 
 example copyparty config to use this:
-  --urlform save,get -v.::w:c,e2d,e2t,mte=+a1:c,mtp=a1=ad,bin/mtag/very-bad-idea.py
+  --urlform save,get -v.::w:c,e2d,e2t,mte=+a1:c,mtp=a1=ad,kn,bin/mtag/very-bad-idea.py
 
 recommended deps:
   apt install xdotool libnotify-bin
@@ -64,7 +64,7 @@ EOF
 chmod 755 /usr/local/bin/chromium-browser
 
 # start the server  (note: replace `-v.::rw:` with `-v.::w:` to disallow retrieving uploaded stuff)
-cd ~/Downloads; python3 copyparty-sfx.py --urlform save,get -v.::rw:c,e2d,e2t,mte=+a1:c,mtp=a1=ad,very-bad-idea.py
+cd ~/Downloads; python3 copyparty-sfx.py --urlform save,get -v.::rw:c,e2d,e2t,mte=+a1:c,mtp=a1=ad,kn,very-bad-idea.py
 
 """
 

copyparty/mtag.py

@@ -10,7 +10,7 @@ import sys
 
 from .__init__ import PY2, WINDOWS, unicode
 from .bos import bos
-from .util import REKOBO_LKEY, fsenc, retchk, runcmd, uncyg
+from .util import REKOBO_LKEY, fsenc, retchk, runcmd, uncyg, min_ex
 
 try:
     from typing import Any, Union
@@ -44,6 +44,7 @@ class MParser(object):
 
         self.timeout = 30
         self.force = False
+        self.kill = "t"  # tree; all children recursively
         self.audio = "y"
         self.ext = []
 
@@ -66,6 +67,10 @@ class MParser(object):
                 self.audio = arg[1:]  # [r]equire [n]ot [d]ontcare
                 continue
 
+            if arg.startswith("k"):
+                self.kill = arg[1:]  # [t]ree [m]ain [n]one
+                continue
+
             if arg == "f":
                 self.force = True
                 continue
@@ -499,7 +504,7 @@ class MTag(object):
                 if parser.bin.endswith(".py"):
                     cmd = [sys.executable] + cmd
 
-                args = {"env": env, "timeout": parser.timeout}
+                args = {"env": env, "timeout": parser.timeout, "kill": parser.kill}
 
                 if WINDOWS:
                     args["creationflags"] = 0x4000
@@ -521,6 +526,8 @@ class MTag(object):
                         if tag and tag in zj:
                             ret[tag] = zj[tag]
             except:
-                pass
+                if self.args.mtag_v:
+                    t = "mtag error: tagname {}, parser {}, file {} => {}"
+                    self.log(t.format(tagname, parser.bin, abspath, min_ex()))
 
         return ret

copyparty/util.py

@@ -1565,6 +1565,7 @@ def killtree(root: int) -> None:
 def runcmd(
     argv: Union[list[bytes], list[str]], timeout: Optional[int] = None, **ka: Any
 ) -> tuple[int, str, str]:
+    kill = ka.pop("kill", "t")  # [t]ree [m]ain [n]one
     p = sp.Popen(argv, stdout=sp.PIPE, stderr=sp.PIPE, **ka)
     if not timeout or PY2:
         stdout, stderr = p.communicate()
@@ -1572,12 +1573,27 @@ def runcmd(
         try:
             stdout, stderr = p.communicate(timeout=timeout)
         except sp.TimeoutExpired:
-            killtree(p.pid)
-            stdout, stderr = p.communicate()
+            if kill == "n":
+                return -18, "", ""  # SIGCONT; leave it be
+            elif kill == "m":
+                p.kill()
+            else:
+                killtree(p.pid)
+
+            try:
+                stdout, stderr = p.communicate(timeout=1)
+            except:
+                stdout = b""
+                stderr = b""
 
     stdout = stdout.decode("utf-8", "replace")
     stderr = stderr.decode("utf-8", "replace")
-    return p.returncode, stdout, stderr
+
+    rc = p.returncode
+    if rc is None:
+        rc = -14  # SIGALRM; failed to kill
+
+    return rc, stdout, stderr
 
 
 def chkcmd(argv: Union[list[bytes], list[str]], **ka: Any) -> tuple[str, str]: