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From:   Hengqi Chen <hengqi.chen@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     keescook@chromium.org, luto@amacapital.net, wad@chromium.org,
        alexyonghe@tencent.com, hengqi.chen@gmail.com
Subject: [PATCH v3 3/3] selftests/seccomp: Test seccomp filter load and attach
Date:   Wed, 29 Nov 2023 05:34:40 +0000
Message-Id: <20231129053440.41522-4-hengqi.chen@gmail.com>
In-Reply-To: <20231129053440.41522-1-hengqi.chen@gmail.com>
References: <20231129053440.41522-1-hengqi.chen@gmail.com>
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Add testcases to exercise the newly added seccomp filter
load and attach functionalities.

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
---
 tools/testing/selftests/seccomp/seccomp_bpf.c | 71 +++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 38f651469968..66eb72e6c1a3 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -4735,6 +4735,77 @@ TEST(user_notification_wait_killable_fatal)
 	EXPECT_EQ(SIGTERM, WTERMSIG(status));
 }
 
+TEST(seccomp_filter_load_and_attach)
+{
+	struct sock_filter filter[] = {
+		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
+	};
+	struct sock_fprog prog = {
+		.len = (unsigned short)ARRAY_SIZE(filter),
+		.filter = filter,
+	};
+	int fd, ret, flags;
+
+	ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
+	ASSERT_EQ(0, ret)
+	{
+		TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
+	}
+
+	flags = 0;
+	fd = seccomp(SECCOMP_LOAD_FILTER, flags, &prog);
+	ASSERT_GT(fd, -1);
+
+	flags = SECCOMP_FILTER_FLAG_FILTER_FD;
+	ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &fd);
+	ASSERT_EQ(ret, 0);
+
+	flags = SECCOMP_FILTER_FLAG_FILTER_FD;
+	ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &fd);
+	ASSERT_EQ(ret, -1);
+	ASSERT_EQ(errno, EEXIST);
+
+	flags = 0;
+	ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
+	ASSERT_EQ(ret, 0);
+
+	close(fd);
+}
+
+TEST(seccomp_attach_fd_failed)
+{
+	int fd, ret, flags;
+
+	ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
+	ASSERT_EQ(0, ret)
+	{
+		TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
+	}
+
+	fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	ASSERT_GT(fd, -1);
+
+	/* copy a sock_fprog from a fd */
+	flags = 0;
+	ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &fd);
+	ASSERT_EQ(ret, -1);
+	ASSERT_EQ(errno, EFAULT);
+
+	/* pass a non seccomp filter fd */
+	flags = SECCOMP_FILTER_FLAG_FILTER_FD;
+	ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &fd);
+	ASSERT_EQ(ret, -1);
+	ASSERT_EQ(errno, EINVAL);
+	close(fd);
+
+	/* pass a invalid fd */
+	fd = -1;
+	flags = SECCOMP_FILTER_FLAG_FILTER_FD;
+	ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &fd);
+	ASSERT_EQ(ret, -1);
+	ASSERT_EQ(errno, EBADF);
+}
+
 /*
  * TODO:
  * - expand NNP testing
-- 
2.34.1