05-sim-long_jumps.c

/**
 * Seccomp Library test program
 *
 * Copyright (c) 2012 Red Hat <pmoore@redhat.com>
 * Copyright (c) 2021 Microsoft Corporation <paulmoore@microsoft.com>
 * Author: Paul Moore <paul@paul-moore.com>
 */

/*
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of version 2.1 of the GNU Lesser General Public License as
 * published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, see <http:https://www.gnu.org/licenses>.
 */

#include <errno.h>
#include <unistd.h>
#include <limits.h>
#include <stdlib.h>

#include <seccomp.h>

#include "util.h"

int main(int argc, char *argv[])
{
	int rc;
	int iter, ctr;
	char *syscall;
	struct util_options opts;
	scmp_filter_ctx ctx = NULL;

	rc = util_getopt(argc, argv, &opts);
	if (rc < 0)
		goto out;

	ctx = seccomp_init(SCMP_ACT_KILL);
	if (ctx == NULL)
		return ENOMEM;

	rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, SCMP_SYS(brk), 0);
	if (rc != 0)
		goto out;

	/* same syscall, many chains */
	for (iter = 0; iter < 100; iter++) {
		rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, SCMP_SYS(chdir), 3,
				      SCMP_A0(SCMP_CMP_EQ, iter),
				      SCMP_A1(SCMP_CMP_NE, 0x0),
				      SCMP_A2(SCMP_CMP_LT, SSIZE_MAX));
		if (rc != 0)
			goto out;
	}

	/* many syscalls, same chain */
	for (iter = 0, ctr = 0; iter < 10000 && ctr < 100; iter++) {
		if (iter == SCMP_SYS(chdir))
			continue;
		syscall = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE,
							   iter);
		if (syscall) {
			free(syscall);
			rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, iter, 1,
					      SCMP_A0(SCMP_CMP_NE, 0));
			if (rc != 0)
				goto out;
			ctr++;
		}
	}

	rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, SCMP_SYS(close), 0);
	if (rc != 0)
		goto out;

	rc = util_filter_output(&opts, ctx);
	if (rc)
		goto out;

out:
	seccomp_release(ctx);
	return (rc < 0 ? -rc : rc);
}