109 lines
2.9 KiB
C++
109 lines
2.9 KiB
C++
/*
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nsjail - seccomp-bpf sandboxing
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-----------------------------------------
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Copyright 2014 Google Inc. All Rights Reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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#include "sandbox.h"
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#include <linux/filter.h>
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#include <linux/seccomp.h>
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#include <stddef.h>
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#include <stdlib.h>
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#include <sys/prctl.h>
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extern "C" {
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#include "kafel.h"
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}
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#include "logs.h"
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namespace sandbox {
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#ifndef PR_SET_NO_NEW_PRIVS /* in prctl.h since Linux 3.5 */
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#define PR_SET_NO_NEW_PRIVS 38
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#endif /* PR_SET_NO_NEW_PRIVS */
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static bool prepareAndCommit(nsjconf_t* nsjconf) {
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if (nsjconf->kafel_file_path.empty() && nsjconf->kafel_string.empty()) {
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return true;
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}
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if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
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PLOG_W("prctl(PR_SET_NO_NEW_PRIVS, 1) failed");
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return false;
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}
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if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &nsjconf->seccomp_fprog, 0, 0)) {
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PLOG_W("prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER) failed");
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return false;
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}
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return true;
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}
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bool applyPolicy(nsjconf_t* nsjconf) {
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return prepareAndCommit(nsjconf);
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}
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bool preparePolicy(nsjconf_t* nsjconf) {
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if (nsjconf->kafel_file_path.empty() && nsjconf->kafel_string.empty()) {
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return true;
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}
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if (!nsjconf->kafel_file_path.empty() && !nsjconf->kafel_string.empty()) {
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LOG_W(
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"You specified both kafel seccomp policy, and kafel seccomp file. Specify one "
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"only");
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return false;
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}
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kafel_ctxt_t ctxt = kafel_ctxt_create();
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if (!nsjconf->kafel_file_path.empty()) {
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FILE* f = fopen(nsjconf->kafel_file_path.c_str(), "r");
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if (!f) {
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PLOG_W("Couldn't open the kafel seccomp policy file '%s'",
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nsjconf->kafel_file_path.c_str());
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kafel_ctxt_destroy(&ctxt);
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return false;
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}
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LOG_D("Compiling seccomp policy from file: '%s'", nsjconf->kafel_file_path.c_str());
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kafel_set_input_file(ctxt, f);
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}
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if (!nsjconf->kafel_string.empty()) {
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LOG_D("Compiling seccomp policy from string: '%s'", nsjconf->kafel_string.c_str());
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kafel_set_input_string(ctxt, nsjconf->kafel_string.c_str());
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}
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if (kafel_compile(ctxt, &nsjconf->seccomp_fprog) != 0) {
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LOG_W("Could not compile policy: %s", kafel_error_msg(ctxt));
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kafel_ctxt_destroy(&ctxt);
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return false;
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}
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kafel_ctxt_destroy(&ctxt);
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return true;
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}
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void closePolicy(nsjconf_t* nsjconf) {
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if (!nsjconf->seccomp_fprog.filter) {
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return;
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}
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free(nsjconf->seccomp_fprog.filter);
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nsjconf->seccomp_fprog.filter = nullptr;
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nsjconf->seccomp_fprog.len = 0;
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}
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} // namespace sandbox
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