fastrpc: hexagonrpcd: hexagonfs: mapped: return NULL for empty dirs

The mapped_or_empty file implementation uses NULL to denote when an
empty directory should be in place of a non-existent file. Changing the
pointer to the output has no effect. Change the implementation data to a
NULL pointer so empty directories function properly.

README.md

@@ -12,7 +12,7 @@ which lines were entered by the user.
  - libqrtr
  - meson or make
  - protobuf-c
- - qmic (https://github.com/andersson/qmic)
+ - qmic (optional for regenerating QMI, at https://github.com/andersson/qmic)
 
 # Installation
 

fastrpc/hexagonrpcd/hexagonfs_mapped.c

@@ -110,6 +110,7 @@ static int mapped_openat(struct hexagonfs_fd *dir,
 
 	ctx->dir = NULL;
 
+	fd->is_assigned = false;
 	fd->up = dir;
 	fd->ops = &hexagonfs_mapped_ops;
 	fd->data = ctx;
@@ -227,7 +228,7 @@ static int mapped_or_empty_from_dirent(void *dirent_data, bool dir, void **fd_da
 
 	ret = mapped_from_dirent(dirent_data, dir, fd_data);
 	if (ret)
-		fd_data = NULL;
+		*fd_data = NULL;
 
 	return 0;
 }

fastrpc/hexagonrpcd/hexagonfs_virt_dir.c

@@ -20,6 +20,7 @@
  */
 
 #include <errno.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
@@ -69,6 +70,7 @@ static int virt_dir_openat(struct hexagonfs_fd *dir,
 	if (fd == NULL)
 		return -ENOMEM;
 
+	fd->is_assigned = false;
 	fd->up = dir;
 	fd->ops = ent->ops;
 

fastrpc/hexagonrpcd/listener.c

@@ -73,6 +73,14 @@ static struct fastrpc_io_buffer *allocate_outbufs(const struct fastrpc_function_
 	off_t off;
 	uint32_t *sizes;
 
+	/*
+	 * POSIX allows malloc to return a non-NULL pointer to a zero-size area
+	 * in memory. Since the code below assumes non-zero size if the pointer
+	 * is non-NULL, exit early if we do not need to allocate anything.
+	 */
+	if (out_count == 0)
+		return NULL;
+
 	out_count = def->out_bufs + (def->out_nums && 1);
 	out = malloc(sizeof(struct fastrpc_io_buffer) * out_count);
 	if (out == NULL)

qmi/meson.build

@@ -19,10 +19,17 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #
 
-qmic = find_program('qmic')
+qmic = find_program('qmic', required : false)
 wrapper = files('qmic_wrapper.sh')
 
-qmi = custom_target('qmi_sns_client',
-  command : [wrapper, qmic, '@INPUT@', '@OUTDIR@'],
-  input : 'sns_client.qmi',
-  output : ['qmi_sns_client.c', 'qmi_sns_client.h'])
+if qmic.found()
+  qmi = custom_target('qmi_sns_client',
+    command : [wrapper, qmic, '@INPUT@', '@OUTDIR@'],
+    input : 'sns_client.qmi',
+    output : ['qmi_sns_client.c', 'qmi_sns_client.h'])
+else
+  qmi = custom_target('qmi_sns_client',
+    command : ['cp', '@INPUT@', '@OUTDIR@'],
+    input : ['qmi_sns_client.c', 'qmi_sns_client.h'],
+    output : ['qmi_sns_client.c', 'qmi_sns_client.h'])
+endif

qmi/qmi_sns_client.c

@@ -0,0 +1,81 @@
+#include <errno.h>
+#include <string.h>
+#include "qmi_sns_client.h"
+
+struct qmi_elem_info sns_client_req_msg_v01_ei[] = {
+	{
+		.data_type = QMI_DATA_LEN,
+		.elem_len = 1,
+		.elem_size = sizeof(uint16_t),
+		.tlv_type = 1,
+		.offset = offsetof(struct sns_client_req_msg_v01, payload_len),
+	},
+	{
+		.data_type = QMI_UNSIGNED_1_BYTE,
+		.elem_len = 65535,
+		.elem_size = sizeof(uint8_t),
+		.array_type = VAR_LEN_ARRAY,
+		.tlv_type = 1,
+		.offset = offsetof(struct sns_client_req_msg_v01, payload),
+	},
+	{
+		.data_type = QMI_UNSIGNED_1_BYTE,
+		.elem_len = 1,
+		.elem_size = sizeof(uint8_t),
+		.tlv_type = 16,
+		.offset = offsetof(struct sns_client_req_msg_v01, unkfield_1),
+	},
+	{}
+};
+
+struct qmi_elem_info sns_client_resp_msg_v01_ei[] = {
+	{
+		.data_type = QMI_UNSIGNED_4_BYTE,
+		.elem_len = 1,
+		.elem_size = sizeof(uint32_t),
+		.tlv_type = 2,
+		.offset = offsetof(struct sns_client_resp_msg_v01, unkfield_2),
+	},
+	{
+		.data_type = QMI_UNSIGNED_8_BYTE,
+		.elem_len = 1,
+		.elem_size = sizeof(uint64_t),
+		.tlv_type = 16,
+		.offset = offsetof(struct sns_client_resp_msg_v01, client_id),
+	},
+	{
+		.data_type = QMI_UNSIGNED_4_BYTE,
+		.elem_len = 1,
+		.elem_size = sizeof(uint32_t),
+		.tlv_type = 17,
+		.offset = offsetof(struct sns_client_resp_msg_v01, result),
+	},
+	{}
+};
+
+struct qmi_elem_info sns_client_report_ind_msg_v01_ei[] = {
+	{
+		.data_type = QMI_UNSIGNED_8_BYTE,
+		.elem_len = 1,
+		.elem_size = sizeof(uint64_t),
+		.tlv_type = 1,
+		.offset = offsetof(struct sns_client_report_ind_msg_v01, client_id),
+	},
+	{
+		.data_type = QMI_DATA_LEN,
+		.elem_len = 1,
+		.elem_size = sizeof(uint16_t),
+		.tlv_type = 2,
+		.offset = offsetof(struct sns_client_report_ind_msg_v01, payload_len),
+	},
+	{
+		.data_type = QMI_UNSIGNED_1_BYTE,
+		.elem_len = 65535,
+		.elem_size = sizeof(uint8_t),
+		.array_type = VAR_LEN_ARRAY,
+		.tlv_type = 2,
+		.offset = offsetof(struct sns_client_report_ind_msg_v01, payload),
+	},
+	{}
+};
+

qmi/qmi_sns_client.h

@@ -0,0 +1,36 @@
+#ifndef __QMI_SNS_CLIENT_H__
+#define __QMI_SNS_CLIENT_H__
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "libqrtr.h"
+
+#define SNS_CLIENT_REQ_V01 32
+#define SNS_CLIENT_RESP_V01 32
+#define SNS_CLIENT_IND_V01_SMALL 33
+#define SNS_CLIENT_IND_V01_LARGE 34
+
+struct sns_client_req_msg_v01 {
+	uint32_t payload_len;
+	uint8_t payload[65535];
+	uint8_t unkfield_1;
+};
+
+struct sns_client_resp_msg_v01 {
+	uint32_t unkfield_2;
+	uint64_t client_id;
+	uint32_t result;
+};
+
+struct sns_client_report_ind_msg_v01 {
+	uint64_t client_id;
+	uint32_t payload_len;
+	uint8_t payload[65535];
+};
+
+extern struct qmi_elem_info sns_client_req_msg_v01_ei[];
+extern struct qmi_elem_info sns_client_resp_msg_v01_ei[];
+extern struct qmi_elem_info sns_client_report_ind_msg_v01_ei[];
+
+#endif