tools: make json-c optional

This shouldn't be a requirement to compile anything else. Stop requiring
it for building anything, and assume the user just wants to compile the
main project.

Signed-off-by: Richard Acayan <mailingradian@gmail.com>

.github/workflows/build.yaml

@@ -0,0 +1,29 @@
+name: Buildtest
+
+on:
+  pull_request:
+  push:
+
+jobs:
+  build-linux:
+    strategy: 
+      fail-fast: false
+      matrix:
+        include:
+          - runner: ubuntu-24.04
+          # 22.04 has old meson
+          # - runner: ubuntu-22.04
+    runs-on: ${{ matrix.runner }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Dependencies
+        run: |
+          sudo apt update
+          sudo apt install -y meson ninja-build libjson-c-dev
+
+      - name: build
+        run: |
+          meson setup build
+          ninja -C build

README.md

@@ -125,19 +125,26 @@ Interfaces are initialized in the `start_reverse_tunnel` function, in hexagonrpc
 ## HexagonFS
 
 The reverse tunnel's `apps_std` interface serves files to the remote processor.
-These files are searched for in:
+These files are searched for in a directory tree, starting at the location
+defined by the `-R` option, or in `/usr/share/qcom` by default:
 
-    Physical file/dir			Android file/dir
-    /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
-    /usr/share/qcom/socinfo			/sys/devices/soc0
+    HexagonRPCD file/dir	Android file/dir
+    acdb			/vendor/etc/acdbdata
+    dsp			/vendor/dsp
+    sensors/config		/vendor/etc/sensors/config
+    sensors/registry	/mnt/vendor/persist/sensors/registry/registry
+    sensors/sns_reg.conf	/vendor/etc/sensors/sns_reg_config
+    socinfo			/sys/devices/soc0
 
 These files and directories should be populated with files from your device's
 Android firmware.
 
+If you can pass the `-R` option, the convention is to pass `-R
+/usr/share/qcom/SOC/VENDOR/DEVICE`, where SOC is the SoC name in lowercase,
+VENDOR is the capitalized name of the device vendor, and DEVICE is the device
+name (e.g. `-R /usr/share/qcom/sdm845/SHIFT/axolotl` or `-R
+/usr/share/qcom/sdm845/Thundercomm/db845c`).
+
 # Future plans
 
 Reverse tunnels are separated by the process that opens the file descriptor and

hexagonrpcd/apps_mem.c

@@ -0,0 +1,143 @@
+/*
+ * FastRPC memory mapping interface implementation
+ *
+ * Copyright (C) 2024 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/>.
+ */
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <misc/fastrpc.h>
+#include <sys/ioctl.h>
+
+#include "aee_error.h"
+#include "apps_mem.h"
+#include "interfaces/apps_mem.def"
+#include "listener.h"
+
+// See fastrpc.git/src/apps_mem_imp.c
+#define ADSP_MMAP_HEAP_ADDR 4
+#define ADSP_MMAP_REMOTE_HEAP_ADDR 8
+#define ADSP_MMAP_ADD_PAGES   0x1000
+
+struct apps_mem_ctx {
+	int fd;
+};
+
+static uint32_t apps_mem_request_map64(void *data,
+				       const struct fastrpc_io_buffer *inbufs,
+				       struct fastrpc_io_buffer *outbufs)
+{
+	struct apps_mem_ctx *ctx = data;
+	const struct {
+		uint32_t heap_id;
+		uint32_t lflags;
+		uint32_t rflags;
+		uint32_t padding;
+		uint64_t vin;
+		uint64_t len;
+	} *first_in = inbufs[0].p;
+	struct {
+		uint64_t vapps;
+		uint64_t vadsp;
+	} *first_out = outbufs[0].p;
+	struct fastrpc_req_mmap mmap;
+	int ret;
+
+	if (!(first_in->rflags & ADSP_MMAP_ADD_PAGES)) {
+		fprintf(stderr, "Unsupported mmap operation: DMA buffer request\n");
+		return AEE_EUNSUPPORTED;
+	}
+
+	mmap.fd = -1;
+	mmap.flags = first_in->rflags;
+	mmap.vaddrin = 0;
+	mmap.size = first_in->len;
+
+	ret = ioctl(ctx->fd, FASTRPC_IOCTL_MMAP, &mmap);
+	if (ret == -1) {
+		perror("Memory map failed");
+		return AEE_EFAILED;
+	} else if (ret) {
+		fprintf(stderr, "Memory map failed: %s\n", aee_strerror[ret]);
+		return ret;
+	}
+
+#if HEXAGONRPC_VERBOSE
+	printf("mmap(%d, %x, %x, %lu, %lu) -> %" PRIx64 "\n",
+	       first_in->heap_id,
+	       first_in->lflags,
+	       first_in->rflags,
+	       first_in->vin,
+	       first_in->len,
+	       mmap.vaddrout);
+#endif
+
+	first_out->vapps = 0;
+	first_out->vadsp = mmap.vaddrout & 0xFFFFFFFF;
+	return 0;
+}
+
+struct fastrpc_interface *fastrpc_apps_mem_init(int fd)
+{
+	struct fastrpc_interface *iface;
+	struct apps_mem_ctx *ctx;
+
+	iface = malloc(sizeof(*iface));
+	if (iface == NULL)
+		return NULL;
+
+	ctx = calloc(1, sizeof(*ctx));
+	if (ctx == NULL)
+		goto err_free_iface;
+
+	memcpy(iface, &apps_mem_interface, sizeof(*iface));
+
+	ctx->fd = fd;
+
+	iface->data = ctx;
+
+	return iface;
+
+err_free_iface:
+	free(iface);
+
+	return NULL;
+}
+
+void fastrpc_apps_mem_deinit(struct fastrpc_interface *iface)
+{
+	free(iface->data);
+	free(iface);
+}
+
+static const struct fastrpc_function_impl apps_mem_procs[] = {
+	{ .def = NULL, .impl = NULL, },
+	{ .def = NULL, .impl = NULL, },
+	{ .def = &apps_mem_request_map64_def, .impl = apps_mem_request_map64, },
+	{ .def = NULL, .impl = NULL, },
+	{ .def = NULL, .impl = NULL, },
+	{ .def = NULL, .impl = NULL, },
+};
+
+const struct fastrpc_interface apps_mem_interface = {
+	.name = "apps_mem",
+	.n_procs = 6,
+	.procs = apps_mem_procs,
+};

hexagonrpcd/apps_mem.h

@@ -0,0 +1,30 @@
+/*
+ * FastRPC operating system interface - context initialization
+ *
+ * Copyright (C) 2024 The Sensor Shell Contributors
+ *
+ * This file is part of HexagonRPC.
+ *
+ * HexagonRPC 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_MEM_H
+#define APPS_MEM_H
+
+#include "listener.h"
+
+struct fastrpc_interface *fastrpc_apps_mem_init(int fd);
+void fastrpc_apps_mem_deinit(struct fastrpc_interface *iface);
+
+#endif

hexagonrpcd/apps_std.c

@@ -312,7 +312,7 @@ static uint32_t apps_std_stat(void *data,
 	if (((const char *) inbufs[1].p)[inbufs[1].s - 1] != 0)
 		return AEE_EBADPARM;
 
-	fd = hexagonfs_openat(ctx->fds, ctx->rootfd, ctx->rootfd, pathname);
+	fd = hexagonfs_openat(ctx->fds, ctx->rootfd, ctx->adsp_library_dirfd, pathname);
 	if (fd < 0) {
 		fprintf(stderr, "Could not open %s: %s\n",
 				pathname, strerror(-fd));

hexagonrpcd/hexagonrpcd.1

@@ -0,0 +1,66 @@
+'\" t
+.TH HEXAGONRPCD 1 "2024-09-28" "hexagonrpcd" "Server for FastRPC remote procedure calls from Qualcomm DSPs"
+.SH NAME
+hexagonrpcd - Server for FastRPC remote procedure calls from Qualcomm DSPs
+.SH SYNOPSIS
+\fBhexagonrpcd\fP [\fIoptions\&.\&.\&.\fP] -f \fIDEVICE
+.SH DESCRIPTION
+Server for FastRPC remote procedure calls from Qualcomm DSPs\&.
+.PP
+.SH OPTIONS
+.TP
+\fB\-c \fISHELL\fP
+Create a new pd running the specified ELF
+\fB\-d \fIDSP\fP
+DSP name (default: )
+.TP
+\fB\-f \fIDEVICE\fP
+FastRPC device node to attach to
+.TP
+\fB\-p \fIPROGRAM\fP
+Run client program with shared file descriptor
+.TP
+\fB\-R \fIDIR\fP
+Root directory of served files (default: /usr/share/qcom/)
+.TP
+\fB\-s\fP
+Attach to sensorspd
+.PP
+.SH NOTES
+
+Hexagonrpcd serves files to the remote processor via a reverse tunnel interface
+to the remote processor. These files are by default searched for in:
+
+These files are searched for in a directory tree, starting at the location
+defined by the -R option, or in /usr/share/qcom by default:
+
+.TS
+l l
+---
+l l. 
+HexagonRPCD file/dir    Android file/dir
+acdb                    /vendor/etc/acdbdata
+dsp                     /vendor/dsp
+sensors/config          /vendor/etc/sensors/config
+sensors/registry        /mnt/vendor/persist/sensors/registry/registry
+sensors/sns_reg.conf    /vendor/etc/sensors/sns_reg_config
+socinfo                 /sys/devices/soc0
+.TE
+
+These files and directories should be populated with files from your device's
+Android firmware.
+
+If you can pass the -R option, the convention is to pass -R
+/usr/share/qcom/SOC/VENDOR/DEVICE, where SOC is the SoC name in lowercase,
+VENDOR is the capitalized name of the device vendor, and DEVICE is the device
+name (e.g. -R /usr/share/qcom/sdm845/SHIFT/axolotl or -R
+/usr/share/qcom/sdm845/Thundercomm/db845c).
+
+.SH AUTHORS
+hexagonrpcd was written by The HexagonRPC Contributors <https://github.com/linux-msm/hexagonrpc>
+.SH COPYRIGHT
+Copyright (C) 2024 The HexagonRPC Contributors <https://github.com/linux-msm/hexagonrpc>
+Copyright (C) 2023 The Sensor Shell Contributors <https://github.com/linux-msm/hexagonrpc>
+.PP
+Released under GPL-3+ license\&.
+

hexagonrpcd/interfaces.c

@@ -22,5 +22,6 @@
 #define HEXAGONRPC_BUILD_METHOD_DEFINITIONS 1
 
 #include "interfaces/adsp_default_listener.def"
+#include "interfaces/apps_mem.def"
 #include "interfaces/apps_std.def"
 #include "interfaces/adsp_listener.def"

hexagonrpcd/interfaces/apps_mem.def

@@ -0,0 +1,29 @@
+/*
+ * FastRPC operating system interface
+ *
+ * Copyright (C) 2024 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 INTERFACE_APPS_MEM_DEF
+#define INTERFACE_APPS_MEM_DEF
+
+#include <libhexagonrpc/interface.h>
+
+HEXAGONRPC_DEFINE_REMOTE_METHOD(2, apps_mem_request_map64, 8, 0, 4, 0)
+
+#endif /* INTERFACE_APPS_MEM_DEF */

hexagonrpcd/listener.c

@@ -112,7 +112,7 @@ static int check_inbuf_sizes(const struct fastrpc_function_def_interp2 *def,
 	uint8_t i;
 	const uint32_t *sizes = &((const uint32_t *) inbufs[0].p)[def->in_nums];
 
-	if (inbufs[0].s != 4 * (def->in_nums
+	if (inbufs[0].s != 4U * (def->in_nums
 			      + def->in_bufs
 			      + def->out_bufs)) {
 		fprintf(stderr, "Invalid number of input numbers: %" PRIu32 " (expected %u)\n",

hexagonrpcd/listener.h

@@ -44,6 +44,7 @@ struct fastrpc_interface {
 
 extern const struct fastrpc_interface localctl_interface;
 
+extern const struct fastrpc_interface apps_mem_interface;
 extern const struct fastrpc_interface apps_std_interface;
 
 int run_fastrpc_listener(int fd,

hexagonrpcd/meson.build

@@ -1,5 +1,6 @@
 executable('hexagonrpcd',
   'aee_error.c',
+  'apps_mem.c',
   'apps_std.c',
   'interfaces.c',
   'hexagonfs.c',
@@ -17,3 +18,4 @@ executable('hexagonrpcd',
   link_with : libhexagonrpc,
   install_dir : get_option('bindir'),
 )
+install_man('hexagonrpcd.1')

hexagonrpcd/rpcd.c

@@ -30,9 +30,12 @@
 #include <stdio.h>
 #include <string.h>
 #include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 
 #include "aee_error.h"
+#include "apps_mem.h"
 #include "apps_std.h"
 #include "hexagonfs.h"
 #include "interfaces/adsp_default_listener.def"
@@ -132,6 +135,7 @@ static void print_usage(const char *argv0)
 	printf("Usage: %s [options] -f DEVICE\n\n", argv0);
 	printf("Server for FastRPC remote procedure calls from Qualcomm DSPs\n\n"
 	       "Options:\n"
+	       "\t-c SHELL\t\tCreate a new pd running the specified ELF\n"
 	       "\t-d DSP\t\tDSP name (default: "")\n"
 	       "\t-f DEVICE\tFastRPC device node to attach to\n"
 	       "\t-p PROGRAM\tRun client program with shared file descriptor\n"
@@ -139,6 +143,60 @@ static void print_usage(const char *argv0)
 	       "\t-s\t\tAttach to sensorspd\n");
 }
 
+static int create_shell_pd(int fd, const char *create_shell)
+{
+	char *buf;
+	int shellfd, ret;
+	struct stat stats;
+	struct fastrpc_alloc_dma_buf dmabuf;
+	long page_size;
+	struct fastrpc_init_create init = {
+		.attrs = 0,
+		.siglen = 0,
+	};
+
+	shellfd = open(create_shell, O_RDONLY);
+	if (shellfd == -1) {
+		fprintf(stderr, "Could not open %s: %s\n",
+			create_shell, strerror(errno));
+		return -1;
+	}
+
+	ret = fstat(shellfd, &stats);
+	if (ret == -1)
+		goto err_close_fd;
+
+	page_size = sysconf(_SC_PAGE_SIZE);
+	dmabuf.size = (stats.st_size + page_size - 1) & ~(page_size - 1);
+	dmabuf.flags = 0;
+
+	ret = ioctl(fd, FASTRPC_IOCTL_ALLOC_DMA_BUFF, &dmabuf);
+	if (ret)
+		goto err_close_fd;
+
+	buf = mmap(NULL, dmabuf.size, PROT_WRITE, MAP_SHARED, dmabuf.fd, 0);
+	if (buf == MAP_FAILED) {
+		ret = -1;
+		goto err_close_dmabuf;
+	}
+
+	read(shellfd, buf, stats.st_size);
+
+	init.file = (__u64) buf;
+	init.filefd = dmabuf.fd;
+	init.filelen = stats.st_size;
+
+	ret = ioctl(fd, FASTRPC_IOCTL_INIT_CREATE, &init);
+
+	munmap(buf, dmabuf.size);
+err_close_dmabuf:
+	close(dmabuf.fd);
+err_close_fd:
+	close(shellfd);
+
+	return ret;
+}
+
 static int setup_environment(int fd)
 {
 	char *buf;
@@ -196,7 +254,7 @@ static void *start_reverse_tunnel(int fd, const char *device_dir, const char *ds
 {
 	struct fastrpc_interface **ifaces;
 	struct hexagonfs_dirent *root_dir;
-	size_t n_ifaces = 2;
+	size_t n_ifaces = 3;
 	int ret;
 
 	ifaces = malloc(sizeof(struct fastrpc_interface) * n_ifaces);
@@ -214,6 +272,7 @@ static void *start_reverse_tunnel(int fd, const char *device_dir, const char *ds
 
 	// Dynamic interfaces with no hardcoded handle
 	ifaces[1] = fastrpc_apps_std_init(root_dir);
+	ifaces[2] = fastrpc_apps_mem_init(fd);
 
 	ret = register_fastrpc_listener(fd);
 	if (ret)
@@ -233,11 +292,127 @@ err:
 	return NULL;
 }
 
+static char *read_sysfs_file(const char *path, struct stat *file_stat)
+{
+	char *contents = NULL;
+	int fd, res, n_bytes;
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1)
+		return NULL;
+
+	res = fstat(fd, file_stat);
+	if (res)
+		goto close_fd;
+
+	contents = malloc(file_stat->st_size);
+	if (contents == NULL)
+		goto close_fd;
+
+	n_bytes = read(fd, contents, file_stat->st_size);
+	if (n_bytes != file_stat->st_size) {
+		free(contents);
+		contents = NULL;
+	}
+
+close_fd:
+	close(fd);
+
+	return contents;
+}
+
+/*
+ * Guesses the device's HexagonFS directory from the model and compatible
+ * properties in the device-tree.
+ *
+ * The vendor name is guessed by splitting the model property at the first
+ * space to preserve the canonical capitalization of the name.
+ *
+ * The SoC name is assumed to be part of the first property in the compatible
+ * list that starts with "qcom,".
+ *
+ * Finally, all compatible entries are split at the first , and the all
+ * right-hand sides of the entry considered as the codename.
+ *
+ * It returns the first guessed combination of all 3 for which a path exists
+ * at /usr/share/qcom/{soc}/{vendor}/{codename}.
+ * If no match is found, a null pointer is returned.
+ */
+static char *guess_device_directory_from_compatible(void)
+{
+	char *compatible_ptr, *device_name, *model_ptr, *orig_compatible_ptr,
+		*end_of_vendor_name, *vendor_name;
+	char *chipset_name = NULL;
+	char *ret = NULL;
+	struct stat compatible_stat, model_stat;
+
+	compatible_ptr = read_sysfs_file("/proc/device-tree/compatible",
+					 &compatible_stat);
+	if (compatible_ptr == NULL)
+		return NULL;
+	orig_compatible_ptr = compatible_ptr;
+
+	model_ptr = read_sysfs_file("/proc/device-tree/model", &model_stat);
+	if (model_ptr == NULL)
+		goto free_compatible;
+
+	end_of_vendor_name = strchr(model_ptr, ' ');
+	if (end_of_vendor_name == NULL)
+		end_of_vendor_name = model_ptr + model_stat.st_size - 1;
+	vendor_name = strndup(model_ptr, end_of_vendor_name - model_ptr);
+	if (vendor_name == NULL)
+		goto free_model;
+
+	while (compatible_ptr < orig_compatible_ptr + compatible_stat.st_size) {
+		if (strncmp("qcom,", compatible_ptr, sizeof("qcom,") - 1) == 0) {
+			chipset_name = compatible_ptr + sizeof("qcom,") - 1;
+			break;
+		}
+
+		compatible_ptr += strlen(compatible_ptr) + 1;
+	}
+
+	if (chipset_name == NULL)
+		goto free_model;
+
+	compatible_ptr = orig_compatible_ptr;
+	while (compatible_ptr < orig_compatible_ptr + compatible_stat.st_size) {
+		char *try_path = NULL;
+
+		device_name = strchr(compatible_ptr, ',');
+		if (device_name == NULL)
+			continue;
+		device_name += 1;
+
+		if (asprintf(&try_path, "/usr/share/qcom/%s/%s/%s",
+			     chipset_name, vendor_name, device_name) < 0)
+			goto free_model;
+
+		if (!access(try_path, R_OK)) {
+			ret = try_path;
+			break;
+		}
+
+		free(try_path);
+
+		compatible_ptr += strlen(compatible_ptr) + 1;
+	}
+
+free_model:
+	free(model_ptr);
+free_compatible:
+	free(orig_compatible_ptr);
+
+	return ret;
+}
+
 int main(int argc, char* argv[])
 {
 	char *fastrpc_node = NULL;
 	const char *device_dir = "/usr/share/qcom/";
 	const char *dsp = "";
+	const char *create_shell = NULL;
+	const char *guessed_device_dir;
 	const char **progs;
 	pid_t *pids;
 	size_t n_progs = 0;
@@ -256,8 +431,15 @@ int main(int argc, char* argv[])
 		goto err_free_progs;
 	}
 
-	while ((opt = getopt(argc, argv, "d:f:p:R:s")) != -1) {
+	guessed_device_dir = guess_device_directory_from_compatible();
+	if (guessed_device_dir != NULL)
+		device_dir = guessed_device_dir;
+
+	while ((opt = getopt(argc, argv, "c:d:f:p:R:s")) != -1) {
 		switch (opt) {
+			case 'c':
+				create_shell = optarg;
+				break;
 			case 'd':
 				dsp = optarg;
 				break;
@@ -295,6 +477,8 @@ int main(int argc, char* argv[])
 
 	if (attach_sns)
 		ret = ioctl(fd, FASTRPC_IOCTL_INIT_ATTACH_SNS, NULL);
+	else if (create_shell != NULL)
+		ret = create_shell_pd(fd, create_shell);
 	else
 		ret = ioctl(fd, FASTRPC_IOCTL_INIT_ATTACH, NULL);
 	if (ret) {

libhexagonrpc/meson.build

@@ -5,7 +5,7 @@ libhexagonrpc = shared_library('hexagonrpc',
   'session.c',
   c_args : cflags,
   include_directories : include,
-  soversion : version,
+  soversion : api_version,
   install : true
 )
 

meson.build

@@ -1,6 +1,7 @@
-project('fastrpc', 'c')
+project('fastrpc', 'c', version: '0.4.0', meson_version: '>=1.1')
 
-version = '0.3.2'
+version_array = meson.project_version().split('.')
+api_version = version_array[0] + '.' + version_array[1]
 
 include = include_directories('include')
 client_target = get_option('libexecdir') / 'hexagonrpc'
@@ -15,4 +16,6 @@ subdir('libhexagonrpc')
 subdir('hexagonrpcd')
 subdir('chrecd')
 
+subdir('tools')
+
 subdir('tests')

tools/meson.build

@@ -0,0 +1,8 @@
+json_c = dependency('json-c', required : false)
+
+if json_c.found()
+  executable('sscregistrygen',
+    'sscregistrygen.c',
+    c_args : cflags,
+    dependencies : [json_c])
+endif

tools/sscregistrygen.c

@@ -0,0 +1,313 @@
+/*
+ * Registry File Generator
+ *
+ * Copyright (C) 2023 Richard Acayan
+ *
+ * sscregistrygen 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/>.
+ */
+
+/*
+ * Typical usage with HexagonFS default physical filesystem structure and
+ * mainline Linux:
+ *
+ * registry -p OEM -s $(< /sys/devices/soc0/soc_id) \
+ *	    /etc/qcom/sensors.d/ /var/lib/qcom/sensors/registry/
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <json.h>
+
+// Not implemented in GNU C library
+#ifndef O_SEARCH
+#define O_SEARCH O_RDONLY
+#endif
+
+struct config_filter {
+	const char *hw_platform;
+	// This is represented by a string, so don't bother converting it
+	const char *soc_id;
+};
+
+void create_registry_file(int dirfd, const char *name, struct json_object *obj);
+
+/*
+ * This returns the default reference object. It interacts with static memory
+ * and is therefore not thread safe.
+ */
+struct json_object *get_default_ref()
+{
+	static struct json_object *ref = NULL;
+	struct json_object *type, *ver, *data;
+
+	if (ref == NULL) {
+		type = json_object_new_string("grp");
+		ver = json_object_new_string("0");
+		data = json_object_new_string("");
+
+		ref = json_object_new_object();
+		json_object_object_add(ref, "type", type);
+		json_object_object_add(ref, "ver", ver);
+		json_object_object_add(ref, "data", data);
+	}
+
+	/*
+	 * Static storage will always hold a reference, unaffected by the
+	 * calling functions. That unfortunately means that we cannot free
+	 * everything on exit.
+	 */
+	json_object_get(ref);
+
+	return ref;
+}
+
+void add_child(int dirfd,
+	       const char *parent_name, const char *name,
+	       struct json_object *parent, struct json_object *obj)
+{
+	struct json_object *ref;
+	int n_parent_name, n_name;
+	char *filename;
+
+	if (name[0] == '.') {
+		n_parent_name = strlen(parent_name);
+		n_name = strlen(name);
+
+		filename = malloc(n_parent_name + n_name + 1);
+		if (filename == NULL)
+			return;
+
+		memcpy(filename, parent_name, n_parent_name);
+		memcpy(&filename[n_parent_name], name, n_name);
+		filename[n_parent_name + n_name] = '\0';
+
+		create_registry_file(dirfd, filename, obj);
+
+		free(filename);
+
+		ref = get_default_ref();
+
+		// Held reference transferred
+		json_object_object_add(parent, &name[1], ref);
+	} else {
+		// Hold reference for parent
+		json_object_get(obj);
+		json_object_object_add(parent, name, obj);
+	}
+}
+
+/*
+ * Creates a registry file, and registry files that are nested in the given
+ * JSON object.
+ */
+void create_registry_file(int dirfd, const char *name, struct json_object *obj)
+{
+	struct json_object *out, *root;
+	struct json_object_iterator iter, end;
+	const char *child;
+	struct json_object *val;
+	const char *contents;
+	int fd;
+
+	root = json_object_new_object();
+
+	out = json_object_new_object();
+	json_object_object_add(root, name, out);
+
+	iter = json_object_iter_begin(obj);
+	end = json_object_iter_end(obj);
+
+	while (!json_object_iter_equal(&iter, &end)) {
+		child = json_object_iter_peek_name(&iter);
+		val = json_object_iter_peek_value(&iter);
+
+		add_child(dirfd, name, child, out, val);
+
+		json_object_iter_next(&iter);
+	}
+
+	contents = json_object_to_json_string_ext(root,
+						  JSON_C_TO_STRING_PLAIN
+						| JSON_C_TO_STRING_NOSLASHESCAPE);
+
+	fd = openat(dirfd, name, O_WRONLY | O_CREAT,
+		    (mode_t) (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH));
+	if (fd == -1)
+		return;
+
+	write(fd, contents, strlen(contents));
+
+	close(fd);
+
+	json_object_put(root);
+}
+
+bool check_config_filter(struct config_filter *filter, struct json_object *config)
+{
+	struct json_object *hw_plat, *soc_id;
+	struct json_object *curr;
+	const char *str;
+	size_t len, i;
+
+	hw_plat = json_object_object_get(config, "hw_platform");
+	if (filter->hw_platform != NULL
+	 && hw_plat != NULL
+	 && json_object_get_type(hw_plat) == json_type_array) {
+		len = json_object_array_length(hw_plat);
+
+		for (i = 0; i < len; i++) {
+			curr = json_object_array_get_idx(hw_plat, i);
+			str = json_object_get_string(curr);
+			if (!strcmp(str, filter->hw_platform))
+				break;
+		}
+
+		if (i >= len)
+			return false;
+	}
+
+	soc_id = json_object_object_get(config, "soc_id");
+	if (filter->soc_id != NULL
+	 && soc_id != NULL
+	 && json_object_get_type(soc_id) == json_type_array) {
+		len = json_object_array_length(soc_id);
+
+		for (i = 0; i < len; i++) {
+			curr = json_object_array_get_idx(soc_id, i);
+			str = json_object_get_string(curr);
+			if (!strcmp(str, filter->soc_id))
+				break;
+		}
+
+		if (i >= len)
+			return false;
+	}
+
+	return true;
+}
+
+void apply_sensor_configuration(struct config_filter *filter,
+				int indir, int outdir, const char *file)
+{
+	struct json_object *in;
+	struct json_object *config;
+	const char *name;
+	struct json_object *val;
+	struct json_object_iterator iter, end;
+	int fd;
+
+	fd = openat(indir, file, O_RDONLY);
+	if (fd == -1)
+		return;
+
+	in = json_object_from_fd(fd);
+
+	close(fd);
+
+	config = json_object_object_get(in, "config");
+	if (config != NULL) {
+		if (!check_config_filter(filter, config))
+			return;
+	}
+
+	iter = json_object_iter_begin(in);
+	end = json_object_iter_end(in);
+
+	while (!json_object_iter_equal(&iter, &end)) {
+		name = json_object_iter_peek_name(&iter);
+		val = json_object_iter_peek_value(&iter);
+
+		if (strcmp(name, "config"))
+			create_registry_file(outdir, name, val);
+
+		json_object_iter_next(&iter);
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct dirent *dirent;
+	DIR *indir;
+	int indirfd, outdirfd;
+	struct config_filter filter;
+	int opt;
+
+	filter.hw_platform = NULL;
+	filter.soc_id = NULL;
+
+	while ((opt = getopt(argc, argv, ":p:s:")) != -1) {
+		switch (opt) {
+		case 'p':
+			filter.hw_platform = strdup(optarg);
+			break;
+		case 's':
+			filter.soc_id = strdup(optarg);
+			break;
+		case ':':
+			fprintf(stderr, "Option -%c requires an argument\n", optopt);
+			return 1;
+		case '?':
+		default:
+			fprintf(stderr, "Unknown option: -%c\n", optopt);
+			return 1;
+		};
+	}
+
+	if (argc < optind + 2) {
+		printf("Please specify the input and output directories.\n");
+		return 1;
+	}
+
+	indir = opendir(argv[optind]);
+	if (indir == NULL) {
+		fprintf(stderr, "Could not open %s: %s\n",
+				argv[optind], strerror(-errno));
+		return 1;
+	}
+
+	indirfd = open(argv[optind], O_SEARCH | O_DIRECTORY);
+	if (indirfd == -1) {
+		fprintf(stderr, "Could not open %s: %s\n",
+				argv[optind], strerror(-errno));
+		return 1;
+	}
+
+	outdirfd = open(argv[optind + 1], O_SEARCH | O_DIRECTORY);
+	if (outdirfd == -1) {
+		fprintf(stderr, "Could not open %s: %s\n",
+				argv[optind + 1], strerror(-errno));
+		return 1;
+	}
+
+	dirent = readdir(indir);
+
+	while (dirent != NULL) {
+		if (!strcmp(dirent->d_name, ".")
+		 || !strcmp(dirent->d_name, ".."))
+			goto next;
+
+		apply_sensor_configuration(&filter, indirfd, outdirfd, dirent->d_name);
+
+	next:
+		dirent = readdir(indir);
+	}
+
+	return 0;
+}