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/README.md

@@ -14,9 +14,11 @@ interface compiler or a free software alternative.
 
 ## Installation
 
-There is currently no build system.
+You can build and install this project using meson:
 
-    $ gcc -o libhexagonrpc.so -shared fastrpc.c context.c
+    ~/sensh/fastrpc $ meson setup build
+    ~/sensh/fastrpc $ ninja -C build
+    ~/sensh/fastrpc # ninja -C build install
 
 ## Usage
 
@@ -24,19 +26,27 @@ Making already-defined method calls is relatively straightforward, depending on
 the remote method that you're calling. You just need the function definition, an
 open file descriptor, the handle, and the arguments for it.
 
+    uint32_t prev_ctx, prev_result, nested_outbufs_len;
+    uint32_t ctx, nested_handle, nested_sc, nested_inbufs_len;
+    uint32_t nested_inbufs_size;
+    const void *nested_outbufs;
+    void *nested_inbufs;
+    int fd;
+
     ret = fastrpc2(&adsp_listener_next2_def, fd, ADSP_LISTENER_HANDLE,
     	       prev_ctx,
     	       prev_result,
     	       nested_outbufs_len, nested_outbufs,
-    	       ctx,
-    	       nested_handle,
-    	       nested_sc,
-    	       nested_inbufs_len,
+    	       &ctx,
+    	       &nested_handle,
+    	       &nested_sc,
+    	       &nested_inbufs_len,
     	       nested_inbufs_size, nested_inbufs);
 
-All inputs are specified before all outputs. Words in the first input and output
-buffers go in the form of `uint32_t` arguments. Each buffer is accepted as a
-`uint32_t` length and a pointer.
+All inputs are specified before all outputs. Words in the first (called "prim",
+or primary in QAIC-generated code) input and output buffers go in the form of
+`uint32_t` arguments. Each buffer is accepted as a `uint32_t` length and a
+pointer.
 
 ### Creating function definitions
 
@@ -45,8 +55,9 @@ first write a function definition for it. A function definition is a struct with
 information on its method ID and the arguments it accepts.
 
 First, the method ID is taken from the first argument of the
-`REMOTE_METHOD_MAKE()` macro or the second argument of the
-`REMOTE_METHOD_MAKEX()` macro.
+`REMOTE_SCALARS_MAKE()` macro or the second argument of the
+`REMOTE_SCALARS_MAKEX()` macro
+(defined [here](https://android.googlesource.com/platform/external/fastrpc/+/d6d6e3bba244e40e6043bd687f4cacf090a767b5/inc/remote.h#80)).
 
 Example:
 
@@ -109,7 +120,7 @@ or:
 The reverse tunnel calls the `adsp_listener_next2` remote method to receive
 method calls for the Application Processor.
 
-Interfaces are listed in the `fastrpc_listener_interfaces` variable.
+Interfaces are initialized in the `start_reverse_tunnel` function, in hexagonrpcd/rpcd.c.
 
 ## HexagonFS
 
@@ -117,21 +128,17 @@ The reverse tunnel's `apps_std` interface serves files to the remote processor.
 These files are searched for in:
 
     Physical file/dir			Android file/dir
-    /etc/qcom/sns_reg.conf			/vendor/etc/sensors/sns_reg_config
-    /etc/qcom/sensors.d			/vendor/etc/sensors/config
-    /var/lib/qcom/sensors			/mnt/vendor/persist/sensors/registry
-    /usr/lib/qcom/adsp			/vendor/dsp/adsp
-    /usr/lib/qcom/adsp/avs			/vendor/etc/acdbdata
+    /usr/share/qcom/acdb			/vendor/etc/acdbdata
+    /usr/share/qcom/dsp			/vendor/dsp
+    /usr/share/qcom/sensors/config		/vendor/etc/sensors/config
+    /usr/share/qcom/sensors/registry	/mnt/vendor/persist/sensors/registry/registry
+    /usr/share/qcom/sensors/sns_reg.conf	/vendor/etc/sensors/sns_reg_config
 
 These files and directories should be populated with files from your device's
 Android firmware.
 
 # Future plans
 
-This directory is a bit messy. It should be organized into different
-subdirectories and have a build system. This should also be renamed to
-HexagonRPC to avoid a name collision.
-
 Reverse tunnels are separated by the process that opens the file descriptor and
 cannot service requests from other processes that do not share the same file
 descriptor. There should be some daemon that opens the device and allows clients

fastrpc/hexagonrpcd/apps_std.h

@@ -0,0 +1,31 @@
+/*
+ * FastRPC operating system interface - context initialization
+ *
+ * Copyright (C) 2023 The Sensor Shell Contributors
+ *
+ * This file is part of sensh.
+ *
+ * Sensh is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef APPS_STD_H
+#define APPS_STD_H
+
+#include "hexagonfs.h"
+#include "listener.h"
+
+struct fastrpc_interface *fastrpc_apps_std_init(struct hexagonfs_dirent *root);
+void fastrpc_apps_std_deinit(struct fastrpc_interface *iface);
+
+#endif

fastrpc/hexagonrpcd/hexagonfs.c

@@ -1,7 +1,7 @@
 /*
  * Virtual read-only filesystem for Hexagon processors
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *
@@ -29,111 +29,6 @@
 
 #include "hexagonfs.h"
 
-#define HEXAGONFS_MAX_FD 256
-
-#define DEFINE_VIRT_DIR(dirname, files...)				\
-	(struct hexagonfs_dirent) {					\
-		.name = dirname,					\
-		.ops = &hexagonfs_virt_dir_ops,				\
-		.u.dir = (struct hexagonfs_dirent *[]) { files },	\
-	}
-
-#define DEFINE_MAPPED(dirname, path)		\
-	(struct hexagonfs_dirent) {		\
-		.name = dirname,		\
-		.ops = &hexagonfs_mapped_ops,	\
-		.u.phys = path,			\
-	}
-
-#define DEFINE_SYSFILE(dirname, path)			\
-	(struct hexagonfs_dirent) {			\
-		.name = dirname,			\
-		.ops = &hexagonfs_mapped_sysfs_ops,	\
-		.u.phys = path,				\
-	}
-
-static struct hexagonfs_dirent root_dir = DEFINE_VIRT_DIR("/",
-	&DEFINE_VIRT_DIR("mnt",
-		&DEFINE_VIRT_DIR("vendor",
-			&DEFINE_VIRT_DIR("persist",
-				&DEFINE_VIRT_DIR("sensors",
-					&DEFINE_VIRT_DIR("registry",
-						&DEFINE_MAPPED("registry",
-							       "/var/lib/qcom/sensors"),
-						NULL,
-					),
-					NULL,
-				),
-				NULL,
-			),
-			NULL,
-		),
-		NULL,
-	),
-	&DEFINE_VIRT_DIR("persist",
-		&DEFINE_VIRT_DIR("sensors",
-			&DEFINE_VIRT_DIR("registry",
-				&DEFINE_MAPPED("registry",
-					       "/var/lib/qcom/sensors"),
-				NULL,
-			),
-			NULL,
-		),
-		NULL,
-	),
-	&DEFINE_VIRT_DIR("sys",
-		&DEFINE_VIRT_DIR("devices",
-			&DEFINE_VIRT_DIR("soc0",
-				&DEFINE_SYSFILE("hw_platform",
-						"/sys/kernel/debug/qcom_socinfo/hardware_platform"),
-				&(struct hexagonfs_dirent) {
-					.name = "platform_subtype",
-					.ops = &hexagonfs_plat_subtype_name_ops,
-					.u.phys = "/sys/kernel/debug/qcom_socinfo/hardware_platform_subtype",
-				},
-				&DEFINE_SYSFILE("platform_subtype_id",
-						"/sys/kernel/debug/qcom_socinfo/hardware_platform_subtype"),
-				&DEFINE_SYSFILE("platform_version",
-						"/sys/kernel/debug/qcom_socinfo/platform_version"),
-				&DEFINE_SYSFILE("revision",
-						"/sys/devices/soc0/revision"),
-				&DEFINE_SYSFILE("soc_id",
-						"/sys/devices/soc0/soc_id"),
-				NULL,
-			),
-			NULL,
-		),
-		NULL,
-	),
-	&DEFINE_VIRT_DIR("usr",
-		&DEFINE_VIRT_DIR("lib",
-			&DEFINE_VIRT_DIR("qcom",
-				&DEFINE_MAPPED("adsp",
-					       "/usr/lib/qcom/adsp/"),
-				NULL,
-			),
-			NULL,
-		),
-		NULL,
-	),
-	&DEFINE_VIRT_DIR("vendor",
-		&DEFINE_VIRT_DIR("etc",
-			&DEFINE_VIRT_DIR("sensors",
-				&DEFINE_MAPPED("config",
-					       "/etc/qcom/sensors.d/"),
-				&DEFINE_MAPPED("sns_reg_config",
-					       "/etc/qcom/sns_reg.conf"),
-				NULL,
-			),
-			NULL,
-		),
-		NULL,
-	),
-	NULL,
-);
-
-static struct hexagonfs_fd *fds[HEXAGONFS_MAX_FD];
-
 static char *copy_segment_and_advance(const char *path,
 				      bool *trailing_slash,
 				      const char **next)
@@ -183,7 +78,8 @@ static struct hexagonfs_fd *pop_dir(struct hexagonfs_fd *dir,
 	return up;
 }
 
-static int allocate_file_number(struct hexagonfs_fd *fd)
+static int allocate_file_number(struct hexagonfs_fd **fds,
+				struct hexagonfs_fd *fd)
 {
 	size_t i;
 
@@ -212,7 +108,7 @@ static void destroy_file_descriptor(struct hexagonfs_fd *fd)
 	}
 }
 
-int hexagonfs_open_root()
+int hexagonfs_open_root(struct hexagonfs_fd **fds, struct hexagonfs_dirent *root)
 {
 	struct hexagonfs_fd *fd;
 	int ret;
@@ -221,16 +117,15 @@ int hexagonfs_open_root()
 	if (fd == NULL)
 		return -ENOMEM;
 
-	fd->off = 0;
 	fd->is_assigned = false;
 	fd->up = NULL;
-	fd->ops = root_dir.ops;
+	fd->ops = root->ops;
 
-	ret = root_dir.ops->from_dirent(root_dir.u.ptr, true, &fd->data);
+	ret = root->ops->from_dirent(root->u.ptr, true, &fd->data);
 	if (ret)
 		goto err;
 
-	ret = allocate_file_number(fd);
+	ret = allocate_file_number(fds, fd);
 	if (ret < 0)
 		goto err;
 
@@ -241,7 +136,7 @@ err:
 	return ret;
 }
 
-int hexagonfs_openat(int rootfd, int dirfd, const char *name)
+int hexagonfs_openat(struct hexagonfs_fd **fds, int rootfd, int dirfd, const char *name)
 {
 	struct hexagonfs_fd *fd;
 	const char *curr = name;
@@ -281,7 +176,7 @@ int hexagonfs_openat(int rootfd, int dirfd, const char *name)
 	if (ret)
 		goto err;
 
-	ret = allocate_file_number(fd);
+	ret = allocate_file_number(fds, fd);
 	if (ret)
 		goto err;
 
@@ -293,7 +188,7 @@ err:
 	return ret;
 }
 
-int hexagonfs_close(int fileno)
+int hexagonfs_close(struct hexagonfs_fd **fds, int fileno)
 {
 	struct hexagonfs_fd *fd;
 
@@ -312,7 +207,7 @@ int hexagonfs_close(int fileno)
 	return 0;
 }
 
-int hexagonfs_lseek(int fileno, off_t off, int whence)
+int hexagonfs_lseek(struct hexagonfs_fd **fds, int fileno, off_t off, int whence)
 {
 	struct hexagonfs_fd *fd;
 
@@ -329,7 +224,7 @@ int hexagonfs_lseek(int fileno, off_t off, int whence)
 	return fd->ops->seek(fd, off, whence);
 }
 
-ssize_t hexagonfs_read(int fileno, size_t size, void *ptr)
+ssize_t hexagonfs_read(struct hexagonfs_fd **fds, int fileno, size_t size, void *ptr)
 {
 	struct hexagonfs_fd *fd;
 
@@ -346,7 +241,7 @@ ssize_t hexagonfs_read(int fileno, size_t size, void *ptr)
 	return fd->ops->read(fd, size, ptr);
 }
 
-int hexagonfs_readdir(int fileno, size_t ent_size, char *ent)
+int hexagonfs_readdir(struct hexagonfs_fd **fds, int fileno, size_t ent_size, char *ent)
 {
 	struct hexagonfs_fd *fd;
 
@@ -363,7 +258,7 @@ int hexagonfs_readdir(int fileno, size_t ent_size, char *ent)
 	return fd->ops->readdir(fd, ent_size, ent);
 }
 
-int hexagonfs_fstat(int fileno, struct stat *stats)
+int hexagonfs_fstat(struct hexagonfs_fd **fds, int fileno, struct stat *stats)
 {
 	struct hexagonfs_fd *fd;
 

fastrpc/hexagonrpcd/hexagonfs.h

@@ -1,7 +1,7 @@
 /*
  * Virtual read-only filesystem for Hexagon processors
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *
@@ -27,6 +27,8 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
+#define HEXAGONFS_MAX_FD 256
+
 struct hexagonfs_fd;
 
 struct hexagonfs_file_ops {
@@ -54,7 +56,6 @@ struct hexagonfs_dirent {
 };
 
 struct hexagonfs_fd {
-	off_t off;
 	bool is_assigned;
 	struct hexagonfs_fd *up;
 	void *data;
@@ -63,17 +64,18 @@ struct hexagonfs_fd {
 };
 
 extern struct hexagonfs_file_ops hexagonfs_mapped_ops;
+extern struct hexagonfs_file_ops hexagonfs_mapped_or_empty_ops;
 extern struct hexagonfs_file_ops hexagonfs_mapped_sysfs_ops;
 extern struct hexagonfs_file_ops hexagonfs_plat_subtype_name_ops;
 extern struct hexagonfs_file_ops hexagonfs_virt_dir_ops;
 
-int hexagonfs_open_root();
-int hexagonfs_openat(int rootfd, int dirfd, const char *name);
-int hexagonfs_close(int fileno);
+int hexagonfs_open_root(struct hexagonfs_fd **fds, struct hexagonfs_dirent *root);
+int hexagonfs_openat(struct hexagonfs_fd **fds, int rootfd, int dirfd, const char *name);
+int hexagonfs_close(struct hexagonfs_fd **fds, int fileno);
 
-int hexagonfs_fstat(int fileno, struct stat *stats);
-int hexagonfs_lseek(int fileno, off_t pos, int whence);
-int hexagonfs_readdir(int fileno, size_t size, char *name);
-ssize_t hexagonfs_read(int fileno, size_t size, void *ptr);
+int hexagonfs_fstat(struct hexagonfs_fd **fds, int fileno, struct stat *stats);
+int hexagonfs_lseek(struct hexagonfs_fd **fds, int fileno, off_t pos, int whence);
+int hexagonfs_readdir(struct hexagonfs_fd **fds, int fileno, size_t size, char *name);
+ssize_t hexagonfs_read(struct hexagonfs_fd **fds, int fileno, size_t size, void *ptr);
 
 #endif

fastrpc/hexagonrpcd/hexagonfs_mapped.c

@@ -1,7 +1,7 @@
 /*
  * HexagonFS mapped file/directory operations
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *
@@ -110,7 +110,7 @@ static int mapped_openat(struct hexagonfs_fd *dir,
 
 	ctx->dir = NULL;
 
-	fd->off = 0;
+	fd->is_assigned = false;
 	fd->up = dir;
 	fd->ops = &hexagonfs_mapped_ops;
 	fd->data = ctx;
@@ -126,7 +126,7 @@ err:
 	return ret;
 }
 
-ssize_t mapped_read(struct hexagonfs_fd *fd, size_t size, void *out)
+static ssize_t mapped_read(struct hexagonfs_fd *fd, size_t size, void *out)
 {
 	struct mapped_ctx *ctx = fd->data;
 	ssize_t ret;
@@ -138,7 +138,7 @@ ssize_t mapped_read(struct hexagonfs_fd *fd, size_t size, void *out)
 	return ret;
 }
 
-int mapped_readdir(struct hexagonfs_fd *fd, size_t size, char *out)
+static int mapped_readdir(struct hexagonfs_fd *fd, size_t size, char *out)
 {
 	struct mapped_ctx *ctx = fd->data;
 	struct dirent *ent;
@@ -216,6 +216,89 @@ static int mapped_stat(struct hexagonfs_fd *fd, struct stat *stats)
 	return 0;
 }
 
+static void mapped_or_empty_close(void *fd_data)
+{
+	if (fd_data)
+		mapped_close(fd_data);
+}
+
+static int mapped_or_empty_from_dirent(void *dirent_data, bool dir, void **fd_data)
+{
+	int ret;
+
+	ret = mapped_from_dirent(dirent_data, dir, fd_data);
+	if (ret)
+		*fd_data = NULL;
+
+	return 0;
+}
+
+static int mapped_or_empty_openat(struct hexagonfs_fd *dir,
+				  const char *segment,
+				  bool expect_dir,
+				  struct hexagonfs_fd **out)
+{
+	if (dir->data)
+		return mapped_openat(dir, segment, expect_dir, out);
+	else
+		return -ENOENT;
+}
+
+static ssize_t mapped_or_empty_read(struct hexagonfs_fd *fd,
+				    size_t size, void *out)
+{
+	if (fd->data)
+		return mapped_read(fd, size, out);
+
+	return 0;
+}
+
+static int mapped_or_empty_readdir(struct hexagonfs_fd *fd,
+				   size_t size, char *out)
+{
+	if (fd->data) {
+		return mapped_readdir(fd, size, out);
+	} else {
+		out[0] = '\0';
+		return 0;
+	}
+}
+
+static int mapped_or_empty_seek(struct hexagonfs_fd *fd, off_t off, int whence)
+{
+	if (fd->data)
+		return mapped_seek(fd, off, whence);
+	else
+		return 0;
+}
+
+static int mapped_or_empty_stat(struct hexagonfs_fd *fd, struct stat *stats)
+{
+	if (fd->data) {
+		return mapped_stat(fd, stats);
+	} else {
+		stats->st_size = 0;
+		stats->st_dev = 0;
+		stats->st_rdev = 0;
+		stats->st_ino = 0;
+		stats->st_nlink = 0;
+
+		stats->st_mode = S_IFDIR
+			       | S_IRUSR | S_IXUSR
+			       | S_IRGRP | S_IXGRP
+			       | S_IROTH | S_IXOTH;
+
+		stats->st_atim.tv_sec = 0;
+		stats->st_atim.tv_nsec = 0;
+		stats->st_ctim.tv_sec = 0;
+		stats->st_ctim.tv_nsec = 0;
+		stats->st_mtim.tv_sec = 0;
+		stats->st_mtim.tv_nsec = 0;
+
+		return 0;
+	}
+}
+
 /*
  * This is the sysfs variant of the stat function.
  *
@@ -249,6 +332,16 @@ struct hexagonfs_file_ops hexagonfs_mapped_ops = {
 	.stat = mapped_stat,
 };
 
+struct hexagonfs_file_ops hexagonfs_mapped_or_empty_ops = {
+	.close = mapped_or_empty_close,
+	.from_dirent = mapped_or_empty_from_dirent,
+	.openat = mapped_or_empty_openat,
+	.read = mapped_or_empty_read,
+	.readdir = mapped_or_empty_readdir,
+	.seek = mapped_or_empty_seek,
+	.stat = mapped_or_empty_stat,
+};
+
 struct hexagonfs_file_ops hexagonfs_mapped_sysfs_ops = {
 	.close = mapped_close,
 	.from_dirent = mapped_from_dirent,

fastrpc/hexagonrpcd/hexagonfs_plat_subtype_name.c

@@ -1,7 +1,7 @@
 /*
  * HexagonFS operations for a missing sysfs file
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/hexagonfs_virt_dir.c

@@ -1,7 +1,7 @@
 /*
  * HexagonFS virtual directory operations
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *
@@ -20,6 +20,7 @@
  */
 
 #include <errno.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
@@ -69,7 +70,7 @@ static int virt_dir_openat(struct hexagonfs_fd *dir,
 	if (fd == NULL)
 		return -ENOMEM;
 
-	fd->off = 0;
+	fd->is_assigned = false;
 	fd->up = dir;
 	fd->ops = ent->ops;
 

fastrpc/hexagonrpcd/interfaces.c

@@ -1,7 +1,7 @@
 /*
  * FastRPC interface list for building method definitions
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/interfaces/adsp_default_listener.def

@@ -1,7 +1,7 @@
 /*
  * FastRPC reverse tunnel registration interface
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/interfaces/adsp_listener.def

@@ -1,7 +1,7 @@
 /*
  * FastRPC reverse tunnel main interface
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/interfaces/apps_std.def

@@ -1,7 +1,7 @@
 /*
  * FastRPC operating system interface
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/interfaces/chre_slpi.def

@@ -1,7 +1,7 @@
 /*
  * Context Hub Runtime Environment interface
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/interfaces/remotectl.def

@@ -1,7 +1,7 @@
 /*
  * Remote processor control interface
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/iobuffer.c

@@ -1,7 +1,7 @@
 /*
  * FastRPC reverse tunnel - argument decoder
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/iobuffer.h

@@ -1,7 +1,7 @@
 /*
  * FastRPC reverse tunnel I/O buffer encoder/decoder API
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *

fastrpc/hexagonrpcd/listener.c

@@ -1,7 +1,7 @@
 /*
  * FastRPC reverse tunnel
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *
@@ -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)
@@ -202,7 +210,9 @@ err_free_outbufs:
 	return ret;
 }
 
-static int invoke_requested_procedure(uint32_t handle,
+static int invoke_requested_procedure(size_t n_ifaces,
+				      struct fastrpc_interface **ifaces,
+				      uint32_t handle,
 				      uint32_t sc,
 			              uint32_t *result,
 				      const struct fastrpc_io_buffer *decoded,
@@ -221,19 +231,19 @@ static int invoke_requested_procedure(uint32_t handle,
 		return 1;
 	}
 
-	if (handle >= fastrpc_listener_n_interfaces) {
+	if (handle >= n_ifaces) {
 		fprintf(stderr, "Unsupported handle: %u\n", handle);
 		*result = AEE_EUNSUPPORTED;
 		return 1;
 	}
 
-	if (method >= fastrpc_listener_interfaces[handle]->n_procs) {
+	if (method >= ifaces[handle]->n_procs) {
 		fprintf(stderr, "Unsupported method: %u (%08x)\n", method, sc);
 		*result = AEE_EUNSUPPORTED;
 		return 1;
 	}
 
-	impl = &fastrpc_listener_interfaces[handle]->procs[method];
+	impl = &ifaces[handle]->procs[method];
 
 	if (impl->def == NULL || impl->impl == NULL) {
 		fprintf(stderr, "Unsupported method: %u (%08x)\n", method, sc);
@@ -266,12 +276,14 @@ static int invoke_requested_procedure(uint32_t handle,
 		return 1;
 	}
 
-	*result = impl->impl(decoded, *returned);
+	*result = impl->impl(ifaces[handle]->data, decoded, *returned);
 
 	return 0;
 }
 
-int run_fastrpc_listener(int fd)
+int run_fastrpc_listener(int fd,
+			 size_t n_ifaces,
+			 struct fastrpc_interface **ifaces)
 {
 	struct fastrpc_io_buffer *decoded = NULL,
 				 *returned = NULL;
@@ -298,7 +310,8 @@ int run_fastrpc_listener(int fd)
 		if (returned != NULL)
 			iobuf_free(n_outbufs, returned);
 
-		ret = invoke_requested_procedure(handle, sc, &result,
+		ret = invoke_requested_procedure(n_ifaces, ifaces,
+						 handle, sc, &result,
 						 decoded, &returned);
 		if (ret)
 			break;

fastrpc/hexagonrpcd/listener.h

@@ -1,7 +1,7 @@
 /*
  * FastRPC reverse tunnel - header file
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *
@@ -30,14 +30,16 @@
 
 struct fastrpc_function_impl {
 	const struct fastrpc_function_def_interp2 *def;
-	uint32_t (*impl)(const struct fastrpc_io_buffer *inbufs,
+	uint32_t (*impl)(void *data,
+			 const struct fastrpc_io_buffer *inbufs,
 			 struct fastrpc_io_buffer *outbufs);
 };
 
 struct fastrpc_interface {
 	const char *name;
+	void *data;
 	uint8_t n_procs;
-	struct fastrpc_function_impl procs[];
+	const struct fastrpc_function_impl *procs;
 };
 
 extern const struct fastrpc_interface localctl_interface;
@@ -47,6 +49,8 @@ extern const struct fastrpc_interface apps_std_interface;
 extern const struct fastrpc_interface *fastrpc_listener_interfaces[];
 extern size_t fastrpc_listener_n_interfaces;
 
-int run_fastrpc_listener(int fd);
+int run_fastrpc_listener(int fd,
+			 size_t n_ifaces,
+			 struct fastrpc_interface **ifaces);
 
 #endif

fastrpc/hexagonrpcd/localctl.c

@@ -1,7 +1,7 @@
 /*
  * Application processor control interface
  *
- * Copyright (C) 2023 Richard Acayan
+ * Copyright (C) 2023 The Sensor Shell Contributors
  *
  * This file is part of sensh.
  *
@@ -28,6 +28,12 @@
 #include "interfaces/remotectl.def"
 #include "iobuffer.h"
 #include "listener.h"
+#include "localctl.h"
+
+struct remotectl_ctx {
+	size_t n_ifaces;
+	struct fastrpc_interface **ifaces;
+};
 
 struct remotectl_open_invoke {
 	uint32_t inlen;
@@ -49,20 +55,22 @@ struct remotectl_open_return {
  *
  * The -5 error was taken from Android code.
  */
-static uint32_t localctl_open(const struct fastrpc_io_buffer *inbufs,
+static uint32_t localctl_open(void *data,
+			      const struct fastrpc_io_buffer *inbufs,
 			      struct fastrpc_io_buffer *outbufs)
 {
+	struct remotectl_ctx *ctx = data;
 	const struct remotectl_open_invoke *first_in = inbufs[0].p;
 	struct remotectl_open_return *first_out = outbufs[0].p;
 	size_t i;
 
-	if (((const char *) inbufs[1].p)[first_in->inlen - 1] != 0)
+	if (((const char *) inbufs[1].p)[inbufs[1].s - 1] != 0)
 		return AEE_EBADPARM;
 
 	memset(outbufs[1].p, 0, first_in->outlen);
 
-	for (i = 0; i < fastrpc_listener_n_interfaces; i++) {
-		if (!strcmp(fastrpc_listener_interfaces[i]->name,
+	for (i = 0; i < ctx->n_ifaces; i++) {
+		if (!strcmp(ctx->ifaces[i]->name,
 			    inbufs[1].p)) {
 			first_out->handle = i;
 			first_out->error = 0;
@@ -84,7 +92,8 @@ static uint32_t localctl_open(const struct fastrpc_io_buffer *inbufs,
  * using an interface. It does not need to do anything because interfaces are
  * static.
  */
-static uint32_t localctl_close(const struct fastrpc_io_buffer *inbufs,
+static uint32_t localctl_close(void *data,
+			       const struct fastrpc_io_buffer *inbufs,
 			       struct fastrpc_io_buffer *outbufs)
 {
 	uint32_t *dlerr_size = inbufs[0].p;
@@ -97,11 +106,51 @@ static uint32_t localctl_close(const struct fastrpc_io_buffer *inbufs,
 	return 0;
 }
 
+struct fastrpc_interface *fastrpc_localctl_init(size_t n_ifaces,
+						struct fastrpc_interface **ifaces)
+{
+	struct fastrpc_interface *iface;
+	struct remotectl_ctx *ctx;
+
+	iface = malloc(sizeof(struct fastrpc_interface));
+	if (iface == NULL)
+		return NULL;
+
+	ctx = malloc(sizeof(struct remotectl_ctx));
+	if (ctx == NULL)
+		goto err;
+
+	memcpy(iface, &localctl_interface, sizeof(struct fastrpc_interface));
+
+	ctx->n_ifaces = n_ifaces;
+	ctx->ifaces = ifaces;
+
+	iface->data = ctx;
+
+	return iface;
+
+err:
+	free(iface);
+
+	return NULL;
+}
+
+void fastrpc_localctl_deinit(struct fastrpc_interface *iface)
+{
+	if (iface == NULL)
+		return;
+
+	free(iface->data);
+	free(iface);
+}
+
+static const struct fastrpc_function_impl localctl_procs[] = {
+	{ .def = &remotectl_open_def, .impl = localctl_open, },
+	{ .def = &remotectl_close_def, .impl = localctl_close, },
+};
+
 const struct fastrpc_interface localctl_interface = {
 	.name = "remotectl",
 	.n_procs = 2,
-	.procs = {
-		{ .def = &remotectl_open_def, .impl = localctl_open, },
-		{ .def = &remotectl_close_def, .impl = localctl_close, },
-	},
+	.procs = localctl_procs,
 };