Remove the syscall sandbox

After initially being merged in #20487, it's no-longer clear that an
internal syscall sandboxing mechanism is something that Bitcoin Core
should have/maintain, especially when compared to better
maintained/supported alterantives, i.e firejail.

Note that given where it's used, the sandbox also gets dragged into the
kernel.

There is some related discussion in #24771.

This should not require any sort of deprecation, as this was only ever
an opt-in, experimental feature.

Closes #24771.

test/config.ini.in

@@ -25,5 +25,4 @@ RPCAUTH=@abs_top_srcdir@/share/rpcauth/rpcauth.py
 @ENABLE_FUZZ_TRUE@ENABLE_FUZZ=true
 @ENABLE_ZMQ_TRUE@ENABLE_ZMQ=true
 @ENABLE_EXTERNAL_SIGNER_TRUE@ENABLE_EXTERNAL_SIGNER=true
-@ENABLE_SYSCALL_SANDBOX_TRUE@ENABLE_SYSCALL_SANDBOX=true
 @ENABLE_USDT_TRACEPOINTS_TRUE@ENABLE_USDT_TRACEPOINTS=true

test/functional/feature_notifications.py

@@ -30,9 +30,6 @@ class NotificationsTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
         self.setup_clean_chain = True
-        # The experimental syscall sandbox feature (-sandbox) is not compatible with -alertnotify,
-        # -blocknotify, -walletnotify or -shutdownnotify (which all invoke execve).
-        self.disable_syscall_sandbox = True
 
     def setup_network(self):
         self.wallet = ''.join(chr(i) for i in range(FILE_CHAR_START, FILE_CHAR_END) if chr(i) not in FILE_CHARS_DISALLOWED)

test/functional/feature_startupnotify.py

@@ -18,7 +18,6 @@ FILE_NAME = "test.txt"
 class StartupNotifyTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
-        self.disable_syscall_sandbox = True
 
     def run_test(self):
         tmpdir_file = os.path.join(self.options.tmpdir, NODE_DIR, FILE_NAME)

test/functional/feature_syscall_sandbox.py

@@ -1,34 +0,0 @@
-#!/usr/bin/env python3
-# Copyright (c) 2021-2022 The Bitcoin Core developers
-# Distributed under the MIT software license, see the accompanying
-# file COPYING or http://www.opensource.org/licenses/mit-license.php.
-"""Test bitcoind aborts if a disallowed syscall is used when compiled with the syscall sandbox."""
-
-from test_framework.test_framework import BitcoinTestFramework, SkipTest
-
-
-class SyscallSandboxTest(BitcoinTestFramework):
-    def set_test_params(self):
-        self.num_nodes = 1
-
-    def skip_test_if_missing_module(self):
-        if not self.is_syscall_sandbox_compiled():
-            raise SkipTest("bitcoind has not been built with syscall sandbox enabled.")
-        if self.disable_syscall_sandbox:
-            raise SkipTest("--nosandbox passed to test runner.")
-
-    def run_test(self):
-        disallowed_syscall_terminated_bitcoind = False
-        expected_log_entry = 'ERROR: The syscall "getgroups" (syscall number 115) is not allowed by the syscall sandbox'
-        with self.nodes[0].assert_debug_log([expected_log_entry]):
-            self.log.info("Invoking disallowed syscall")
-            try:
-                self.nodes[0].invokedisallowedsyscall()
-            except ConnectionError:
-                disallowed_syscall_terminated_bitcoind = True
-        assert disallowed_syscall_terminated_bitcoind
-        self.nodes = []
-
-
-if __name__ == "__main__":
-    SyscallSandboxTest().main()

test/functional/feature_versionbits_warning.py

@@ -28,9 +28,6 @@ class VersionBitsWarningTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 1
-        # The experimental syscall sandbox feature (-sandbox) is not compatible with -alertnotify
-        # (which invokes execve).
-        self.disable_syscall_sandbox = True
 
     def setup_network(self):
         self.alert_filename = os.path.join(self.options.tmpdir, "alert.txt")

test/functional/rpc_signer.py

@@ -27,9 +27,6 @@ class RPCSignerTest(BitcoinTestFramework):
 
     def set_test_params(self):
         self.num_nodes = 4
-        # The experimental syscall sandbox feature (-sandbox) is not compatible with -signer (which
-        # invokes execve).
-        self.disable_syscall_sandbox = True
 
         self.extra_args = [
             [],

test/functional/test_framework/test_framework.py

@@ -103,7 +103,6 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         self.supports_cli = True
         self.bind_to_localhost_only = True
         self.parse_args()
-        self.disable_syscall_sandbox = self.options.nosandbox or self.options.valgrind
         self.default_wallet_name = "default_wallet" if self.options.descriptors else ""
         self.wallet_data_filename = "wallet.dat"
         # Optional list of wallet names that can be set in set_test_params to
@@ -160,8 +159,6 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         parser = argparse.ArgumentParser(usage="%(prog)s [options]")
         parser.add_argument("--nocleanup", dest="nocleanup", default=False, action="store_true",
                             help="Leave bitcoinds and test.* datadir on exit or error")
-        parser.add_argument("--nosandbox", dest="nosandbox", default=False, action="store_true",
-                            help="Don't use the syscall sandbox")
         parser.add_argument("--noshutdown", dest="noshutdown", default=False, action="store_true",
                             help="Don't stop bitcoinds after the test execution")
         parser.add_argument("--cachedir", dest="cachedir", default=os.path.abspath(os.path.dirname(os.path.realpath(__file__)) + "/../../cache"),
@@ -188,7 +185,7 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         parser.add_argument("--perf", dest="perf", default=False, action="store_true",
                             help="profile running nodes with perf for the duration of the test")
         parser.add_argument("--valgrind", dest="valgrind", default=False, action="store_true",
-                            help="run nodes under the valgrind memory error detector: expect at least a ~10x slowdown. valgrind 3.14 or later required. Forces --nosandbox.")
+                            help="run nodes under the valgrind memory error detector: expect at least a ~10x slowdown. valgrind 3.14 or later required.")
         parser.add_argument("--randomseed", type=int,
                             help="set a random seed for deterministically reproducing a previous test run")
         parser.add_argument("--timeout-factor", dest="timeout_factor", type=float, help="adjust test timeouts by a factor. Setting it to 0 disables all timeouts")
@@ -497,11 +494,6 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
             extra_args = [[]] * num_nodes
         if versions is None:
             versions = [None] * num_nodes
-        if self.is_syscall_sandbox_compiled() and not self.disable_syscall_sandbox:
-            for i in range(len(extra_args)):
-                # The -sandbox argument is not present in the v22.0 release.
-                if versions[i] is None or versions[i] >= 229900:
-                    extra_args[i] = extra_args[i] + ["-sandbox=log-and-abort"]
         if binary is None:
             binary = [get_bin_from_version(v, 'bitcoind', self.options.bitcoind) for v in versions]
         if binary_cli is None:
@@ -987,7 +979,3 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
     def is_bdb_compiled(self):
         """Checks whether the wallet module was compiled with BDB support."""
         return self.config["components"].getboolean("USE_BDB")
-
-    def is_syscall_sandbox_compiled(self):
-        """Checks whether the syscall sandbox was compiled."""
-        return self.config["components"].getboolean("ENABLE_SYSCALL_SANDBOX")

test/functional/test_runner.py

@@ -210,7 +210,6 @@ BASE_SCRIPTS = [
     'rpc_users.py',
     'rpc_whitelist.py',
     'feature_proxy.py',
-    'feature_syscall_sandbox.py',
     'wallet_signrawtransactionwithwallet.py --legacy-wallet',
     'wallet_signrawtransactionwithwallet.py --descriptors',
     'rpc_signrawtransactionwithkey.py',

test/functional/wallet_signer.py

@@ -45,9 +45,6 @@ class WalletSignerTest(BitcoinTestFramework):
 
     def set_test_params(self):
         self.num_nodes = 2
-        # The experimental syscall sandbox feature (-sandbox) is not compatible with -signer (which
-        # invokes execve).
-        self.disable_syscall_sandbox = True
 
         self.extra_args = [
             [],