From ee5ec83339b56da8c682add16176312d7f1c1bb1 Mon Sep 17 00:00:00 2001
From: Dpeta <69427753+Dpeta@users.noreply.github.com>
Date: Mon, 30 Jan 2023 18:13:11 +0100
Subject: [PATCH] Allow disabling seccomp and update documentation.

---
 README.md     |  3 +++
 libseccomp.py | 10 +++++-----
 pesterchum.py | 39 +++++++++++++++++++++++++--------------
 3 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/README.md b/README.md
index 6e12a1f..1e62636 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,9 @@ Pesterchum is a Python script. This means that as long as you have Python instal
      - Useful for Linux systems that don't meet the Qt6 requirements, as Qt5 Multimedia has a GStreamer dependency.
  - (Optional) [certifi] can provide alternative root certificates for TLS certificate validation.
      - Useful for MacOS, as Python doesn't use the system-provided certificates because of MacOS' outdated SSL library. Also miscellaneous systems without usable root certificates.
+ - (Optional) [libseccomp] and its Python bindings on Linux let Pesterchum apply seccomp-bpf restrictions on itself.
+    - Packages on Arch: ``libseccomp python-libseccomp``
+    - Packages on Debian: ``libseccomp2 python-seccomp``
  
 ### WALKTHROUGH
 
diff --git a/libseccomp.py b/libseccomp.py
index 0d79e73..19e6a74 100644
--- a/libseccomp.py
+++ b/libseccomp.py
@@ -4,7 +4,7 @@ This prevents the process from using certain system calls, which has some securi
 Since Python and Qt use many calls and are pretty high-level, things are prone to breaking though.
 Certain features like opening links almost always break.
 
-Uses libseccomp's Python bindings, which aren't available on the pypi.
+Uses libseccomp's Python bindings, which sadly aren't available on PyPi (yet).
 Check your distro's package manager for python-libseccomp (Arch) or python3-seccomp (Debian).
 
 For info on system calls referencing software that uses seccomp like firejail/flatpak is useful.
@@ -29,8 +29,8 @@ def load_seccomp_blacklist():
     if seccomp is None:
         pesterchum_log.warning(
             "Failed to import seccomp, verify you have"
-            " python-libseccomp (Arch) or python3-seccomp (Debian) installed"
-            " and aren't running a pyinstaller build."
+            " python-libseccomp (Arch) or python3-seccomp (Debian) installed."
+            " If this is a pyinstaller/cx_freeze build, it may also be a linking issue."
         )
         return
     # Allows all calls by default.
@@ -55,8 +55,8 @@ def load_seccomp_whitelist():
     if seccomp is None:
         pesterchum_log.error(
             "Failed to import seccomp, verify you have"
-            " python-libseccomp (Arch) or python3-seccomp (Debian) installed"
-            " and aren't running a pyinstaller build."
+            " python-libseccomp (Arch) or python3-seccomp (Debian) installed."
+            " If this is a pyinstaller/cx_freeze build, it may also be a linking issue."
         )
         return
     # Violation gives "Operation not permitted".
diff --git a/pesterchum.py b/pesterchum.py
index 7460a4d..0f75626 100755
--- a/pesterchum.py
+++ b/pesterchum.py
@@ -110,15 +110,18 @@ parser.add_argument(
     "--nohonk", action="store_true", help="Disables the honk soundeffect 🤡📣"
 )
 if ostools.isLinux():
+    parser.add_argument(
+        "--no-seccomp",
+        action="store_true",
+        help=("Disable seccomp completely. (do this if it causes issues)"),
+    )
     parser.add_argument(
         "--strict-seccomp",
         action="store_true",
         help=(
-            "Restrict the system calls Pesterchum is allowed to make via seccomp."
-            " Has some security benefits, but since Python and Qt use many calls"
-            " and are pretty high-level, things are prone to breaking."
-            " Certain features like opening links always break."
-            " (Requires Linux and libseccomp's Python bindings, not available in frozen builds.)"
+            "Apply a stricter seccomp-bpf filter that only allows required system calls."
+            " This breaks certain features like opening links."
+            " (Requires Linux and libseccomp's Python bindings.)"
         ),
     )
 
@@ -1698,14 +1701,21 @@ class PesterWindow(MovingWindow):
 
         # Activate seccomp on Linux if enabled
         if ostools.isLinux():
-            try:
-                libseccomp.load_seccomp_blacklist()  # Load blacklist always
-                if "strict-seccomp" in options:
-                    if options["strict-seccomp"]:
-                        libseccomp.load_seccomp_whitelist()  # Load whitelist if enabled
-            except RuntimeError:
-                # We probably tried to interact with a call not available on this kernel.
-                PchumLog.exception("")
+            self.seccomp(options)
+
+    def seccomp(self, options):
+        """Load seccomp-bpf filter depending on arguments passed."""
+        if "no-seccomp" in options:
+            if options["no-seccomp"]:
+                return
+        try:
+            libseccomp.load_seccomp_blacklist()  # Load blacklist filter by default
+            if "strict-seccomp" in options:
+                if options["strict-seccomp"]:
+                    libseccomp.load_seccomp_whitelist()  # Load whitelist filter if enabled
+        except RuntimeError:
+            # We probably tried to interact with a call not available on this kernel.
+            PchumLog.exception("")
 
     @QtCore.pyqtSlot(QString, QString)
     def updateMsg(self, ver, url):
@@ -4598,7 +4608,8 @@ class MainProgram(QtCore.QObject):
             if ostools.isLinux():
                 if args.strict_seccomp:
                     options["strict-seccomp"] = True
-
+                if args.no_seccomp:
+                    options["no-seccomp"] = True
         except Exception as e:
             print(e)
             return options