tests: add tests for db_chain_lt()

Add a test to improve the test coverage for db_chain_lt().

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
[PM: stripped the conversion from a macro to function, kept the test]
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 108 insertions, 0 deletions

diff --git a/tests/45-sim-chain_code_coverage.c b/tests/45-sim-chain_code_coverage.c
new file mode 100644
index 0000000..1ae8dab
--- /dev/null
+++ b/tests/45-sim-chain_code_coverage.c
@@ -0,0 +1,108 @@
+/**
+ * Seccomp Library test program
+ *
+ * Copyright (c) 2018 Oracle and/or its affiliates.  All rights reserved.
+ * Author: Tom Hromatka <tom.hromatka@oracle.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://www.gnu.org/licenses>.
+ */
+
+#include <errno.h>
+#include <unistd.h>
+#include <stdbool.h>
+
+#include <seccomp.h>
+
+#include "util.h"
+
+int main(int argc, char *argv[])
+{
+	int rc;
+	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;
+
+	/* the syscall and argument numbers are all fake to make the test
+	 * simpler */
+
+	rc = seccomp_rule_add_exact(ctx, SCMP_ACT_ALLOW, 1008, 1,
+				    SCMP_A0(SCMP_CMP_GE, 1));
+	if (rc != 0)
+		goto out;
+
+	/* db_chain_lt() path #1 - due to "A1" > "A0" */
+	rc = seccomp_rule_add_exact(ctx, SCMP_ACT_ALLOW, 1008, 1,
+				    SCMP_A1(SCMP_CMP_GE, 2));
+	if (rc != 0)
+		goto out;
+
+	/* db_chain_lt() path #2 - due to "GT" > "GE" */
+	rc = seccomp_rule_add_exact(ctx, SCMP_ACT_ALLOW, 1008, 1,
+				    SCMP_A0(SCMP_CMP_GT, 3));
+	if (rc != 0)
+		goto out;
+
+	/* db_chain_lt() path #3 - due to the second mask (0xff) being greater
+	 * than the first (0xf) */
+	rc = seccomp_rule_add_exact(ctx, SCMP_ACT_ALLOW, 1008, 1,
+				    SCMP_A2(SCMP_CMP_MASKED_EQ, 0xf, 4));
+	if (rc != 0)
+		goto out;
+	rc = seccomp_rule_add_exact(ctx, SCMP_ACT_ALLOW, 1008, 1,
+				    SCMP_A2(SCMP_CMP_MASKED_EQ, 0xff, 5));
+	if (rc != 0)
+		goto out;
+
+	/* db_chain_lt() path #4 - due to datum (6) > previous datum (5) */
+	rc = seccomp_rule_add_exact(ctx, SCMP_ACT_ALLOW, 1008, 1,
+				    SCMP_A2(SCMP_CMP_MASKED_EQ, 0xff, 6));
+	if (rc != 0)
+		goto out;
+
+	/* attempt to hit some of the lvl_prv and lvl_nxt code in db.c */
+	rc = seccomp_rule_add_exact(ctx, SCMP_ACT_ALLOW, 1008, 5,
+				    SCMP_A0(SCMP_CMP_NE, 7),
+				    SCMP_A1(SCMP_CMP_LT, 8),
+				    SCMP_A2(SCMP_CMP_EQ, 9),
+				    SCMP_A3(SCMP_CMP_GE, 10),
+				    SCMP_A4(SCMP_CMP_GT, 11),
+				    SCMP_A5(SCMP_CMP_MASKED_EQ, 0xffff, 12));
+	if (rc != 0)
+		goto out;
+	rc = seccomp_rule_add_exact(ctx, SCMP_ACT_ALLOW, 1008, 5,
+				    SCMP_A0(SCMP_CMP_NE, 7),
+				    SCMP_A1(SCMP_CMP_LT, 8),
+				    SCMP_A2(SCMP_CMP_EQ, 9),
+				    SCMP_A3(SCMP_CMP_GE, 10),
+				    SCMP_A4(SCMP_CMP_GT, 11),
+				    SCMP_A5(SCMP_CMP_MASKED_EQ, 0xffff, 13));
+	if (rc != 0)
+		goto out;
+
+	rc = util_filter_output(&opts, ctx);
+	if (rc)
+		goto out;
+
+out:
+	seccomp_release(ctx);
+	return (rc < 0 ? -rc : rc);
+}