userspace: Add audioctl utility to configure audio server

userspace/programs/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(USERSPACE_PROGRAMS
 	audio
+	audioctl
 	AudioServer
 	bananfetch
 	basename

userspace/programs/audioctl/CMakeLists.txt

@@ -0,0 +1,10 @@
+set(SOURCES
+	main.cpp
+)
+
+add_executable(audioctl ${SOURCES})
+banan_link_library(audioctl ban)
+banan_link_library(audioctl libc)
+banan_link_library(audioctl libaudio)
+
+install(TARGETS audioctl OPTIONAL)

userspace/programs/audioctl/main.cpp

@@ -0,0 +1,165 @@
+#include <BAN/Optional.h>
+
+#include <LibAudio/Protocol.h>
+
+#include <errno.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+static uint32_t parse_u32_or_exit(const char* string)
+{
+	errno = 0;
+	char* endptr;
+	const uint32_t result = strtoul(string, &endptr, 0);
+	if (errno || *endptr != '\0')
+	{
+		fprintf(stderr, "invalid integer %s\n", string);
+		exit(1);
+	}
+	return result;
+}
+
+static int get_server_fd()
+{
+	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (fd == -1)
+	{
+		perror("Failed to create a socket");
+		return -1;
+	}
+
+	sockaddr_un addr;
+	addr.sun_family = AF_UNIX;
+	strcpy(addr.sun_path, LibAudio::s_audio_server_socket.data());
+	if (connect(fd, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) == -1)
+	{
+		perror("Failed to connect to audio server");
+		return -1;
+	}
+
+	return fd;
+}
+
+static uint32_t send_request(int fd, LibAudio::Packet packet, bool wait_response)
+{
+	if (ssize_t ret = send(fd, &packet, sizeof(packet), 0); ret != sizeof(packet))
+	{
+		fprintf(stderr, "Failed to send request to server");
+		if (ret < 0)
+			fprintf(stderr, ": %s", strerror(errno));
+		fprintf(stderr, "\n");
+		exit(1);
+	}
+
+	if (!wait_response)
+		return 0;
+
+	uint32_t response;
+	if (ssize_t ret = recv(fd, &response, sizeof(response), 0) != sizeof(response))
+	{
+		fprintf(stderr, "Failed to receive response from server");
+		if (ret < 0)
+			fprintf(stderr, ": %s", strerror(errno));
+		fprintf(stderr, "\n");
+		exit(1);
+	}
+
+	return response;
+}
+
+static void list_devices(int fd)
+{
+	const uint32_t current_device = send_request(fd, { .type = LibAudio::Packet::GetDevice,    .parameter = 0 }, true);
+	const uint32_t current_pin    = send_request(fd, { .type = LibAudio::Packet::GetPin,       .parameter = 0 }, true);
+
+	const uint32_t total_devices  = send_request(fd, { .type = LibAudio::Packet::QueryDevices, .parameter = 0 }, true);
+	for (uint32_t dev = 0; dev < total_devices; dev++)
+	{
+		const uint32_t total_pins = send_request(fd, { .type = LibAudio::Packet::QueryPins, .parameter = dev }, true);
+
+		printf("Device %" PRIu32 "", dev);
+		if (dev == current_device)
+			printf(" (current)");
+		printf("\n");
+
+		for (uint32_t pin = 0; pin < total_pins; pin++)
+		{
+			printf("  Pin %" PRIu32 "", pin);
+			if (dev == current_device && pin == current_pin)
+				printf(" (current)");
+			printf("\n");
+		}
+	}
+}
+
+int main(int argc, char** argv)
+{
+	bool list { false };
+	BAN::Optional<uint32_t> device;
+	BAN::Optional<uint32_t> pin;
+
+	for (;;)
+	{
+		static option long_options[] {
+			{ "list",   no_argument,       nullptr, 'l' },
+			{ "device", required_argument, nullptr, 'd' },
+			{ "pin",    required_argument, nullptr, 'p' },
+			{ "help",   no_argument,       nullptr, 'h' },
+		};
+
+		int ch = getopt_long(argc, argv, "ld:p:h", long_options, nullptr);
+		if (ch == -1)
+			break;
+
+		switch (ch)
+		{
+			case 'h':
+				fprintf(stderr, "usage: %s [OPTIONS]...\n", argv[0]);
+				fprintf(stderr, "  control the audio server\n");
+				fprintf(stderr, "OPTIONS:\n");
+				fprintf(stderr, "  -l, --list      list devices and their pins\n");
+				fprintf(stderr, "  -d, --device N  set device index N as the current one\n");
+				fprintf(stderr, "  -p, --pin N     set pin N as the current one\n");
+				fprintf(stderr, "  -h, --help      show this message and exit\n");
+				return 0;
+			case 'l':
+				list = true;
+				break;
+			case 'd':
+				device = parse_u32_or_exit(optarg);
+				break;
+			case 'p':
+				pin = parse_u32_or_exit(optarg);
+				break;
+			case '?':
+				fprintf(stderr, "invalid option %c\n", optopt);
+				fprintf(stderr, "see '%s --help' for usage\n", argv[0]);
+				return 1;
+		}
+	}
+
+	if (!device.has_value() && !pin.has_value())
+		list = true;
+
+	const int fd = get_server_fd();
+	if (fd == -1)
+		return 1;
+
+	if (device.has_value())
+		send_request(fd, { .type = LibAudio::Packet::SetDevice, .parameter = device.value() }, false);
+
+	if (pin.has_value())
+		send_request(fd, { .type = LibAudio::Packet::SetPin, .parameter = pin.value() }, false);
+
+	if (list)
+		list_devices(fd);
+
+	close(fd);
+
+	return 0;
+}