android/ion: userspace test utility for ion buffer sharing

This is a test utility to verify ION buffer sharing in user space
between 2 independent processes.
It uses unix domain socket (with SCM_RIGHTS) as IPC to transfer an FD to
another process to share the same buffer.
This utility demonstrates how ION buffer sharing can be implemented between
two user space processes, using various heap types.

This utility is made to be run as part of kselftest framework in kernel.
The utility is verified on Ubuntu-32 bit system with Linux Kernel 4.14,
using ION system heap.

For more information about the utility please check the README file.

Signed-off-by: Pintu Agarwal <pintu.ping@gmail.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

1 files changed, 88 insertions, 0 deletions

diff --git a/tools/testing/selftests/android/ion/ionapp_import.c b/tools/testing/selftests/android/ion/ionapp_import.c
new file mode 100644
index 000000000000..ae2d704cfa46
--- /dev/null
+++ b/tools/testing/selftests/android/ion/ionapp_import.c
@@ -0,0 +1,88 @@
+/*
+ * ionapp_import.c
+ *
+ * It is a user space utility to receive android ion memory buffer fd
+ * over unix domain socket IPC that can be exported by ionapp_export.
+ * This acts like a client for ionapp_export.
+ *
+ * Copyright (C) 2017 Pintu Kumar <pintu.ping@gmail.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program 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 General Public License for more details.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include "ionutils.h"
+#include "ipcsocket.h"
+
+
+int main(void)
+{
+	int ret, status;
+	int sockfd, shared_fd;
+	unsigned char *map_buf;
+	unsigned long map_len;
+	struct ion_buffer_info info;
+	struct socket_info skinfo;
+
+	/* This is the client part. Here 0 means client or importer */
+	status = opensocket(&sockfd, SOCKET_NAME, 0);
+	if (status < 0) {
+		fprintf(stderr, "No exporter exists...\n");
+		ret = status;
+		goto err_socket;
+	}
+
+	skinfo.sockfd = sockfd;
+
+	ret = socket_receive_fd(&skinfo);
+	if (ret < 0) {
+		fprintf(stderr, "Failed: socket_receive_fd\n");
+		goto err_recv;
+	}
+
+	shared_fd = skinfo.datafd;
+	printf("Received buffer fd: %d\n", shared_fd);
+	if (shared_fd <= 0) {
+		fprintf(stderr, "ERROR: improper buf fd\n");
+		ret = -1;
+		goto err_fd;
+	}
+
+	memset(&info, 0, sizeof(info));
+	info.buffd = shared_fd;
+	info.buflen = ION_BUFFER_LEN;
+
+	ret = ion_import_buffer_fd(&info);
+	if (ret < 0) {
+		fprintf(stderr, "Failed: ion_use_buffer_fd\n");
+		goto err_import;
+	}
+
+	map_buf = info.buffer;
+	map_len = info.buflen;
+	read_buffer(map_buf, map_len);
+
+	/* Write probably new data to the same buffer again */
+	map_len = ION_BUFFER_LEN;
+	write_buffer(map_buf, map_len);
+
+err_import:
+	ion_close_buffer_fd(&info);
+err_fd:
+err_recv:
+err_socket:
+	closesocket(sockfd, SOCKET_NAME);
+
+	return ret;
+}