Initial support for multiple UIs

Move the device discovery code from separate udev helpers to a single
process to listen on two sockets: one SOCK_DGRAM for incoming udev
events, and one SOCK_STREAM for UIs to connect.

Initial support for client/server infrastructure, still need to wire-up
the udev messages.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 227 insertions, 0 deletions

diff --git a/discover/discover-server.c b/discover/discover-server.c
new file mode 100644
index 0000000..8358f06
--- /dev/null
+++ b/discover/discover-server.c
@@ -0,0 +1,227 @@
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <errno.h>
+#include <assert.h>
+
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <asm/byteorder.h>
+
+#include <talloc/talloc.h>
+
+#include "ui/common/device.h"
+#include "pb-protocol/pb-protocol.h"
+#include "list/list.h"
+
+#include "log.h"
+#include "waiter.h"
+
+struct discover_server {
+	int socket;
+	struct waiter *waiter;
+	struct list clients;
+};
+
+struct client {
+	struct list_item list;
+	int fd;
+};
+
+
+static int server_destructor(void *arg)
+{
+	struct discover_server *server = arg;
+
+	if (server->waiter)
+		waiter_unregister(server->waiter);
+
+	if (server->socket >= 0)
+		close(server->socket);
+
+	return 0;
+}
+
+static int client_destructor(void *arg)
+{
+	struct client *client = arg;
+
+	if (client->fd >= 0)
+		close(client->fd);
+
+	list_remove(&client->list);
+
+	return 0;
+
+}
+
+static void print_clients(struct discover_server *server)
+	__attribute__((unused));
+
+static void print_clients(struct discover_server *server)
+{
+	struct client *client;
+
+	printf("current clients [%p,%p,%p]:\n",
+			&server->clients.head,
+			server->clients.head.prev,
+			server->clients.head.next);
+	list_for_each_entry(&server->clients, client, list)
+		printf("\t[%p,%p,%p] client: %d\n", &client->list,
+				client->list.prev, client->list.next,
+				client->fd);
+}
+
+static struct boot_option options[] = {
+	{
+		.id = "1.1",
+		.name = "meep one",
+		.description = "meep description one",
+		.icon_file = "meep.one.png",
+		.boot_args = "root=/dev/sda1",
+	},
+};
+
+static struct device device = {
+	.id = "1",
+	.name = "meep",
+	.description = "meep description",
+	.icon_file = "meep.png",
+	.n_options = 1,
+	.options = options,
+};
+
+static int client_write_message(struct discover_server *server,
+		struct client *client, struct pb_protocol_message *message)
+{
+	int rc;
+
+	rc = pb_protocol_write_message(client->fd, message);
+	if (rc)
+		talloc_free(client);
+
+	return rc;
+}
+
+static int write_add_message(struct discover_server *server,
+		struct client *client, struct device *dev)
+{
+	struct pb_protocol_message *message;
+	int len;
+
+	len = pb_protocol_device_len(dev);
+
+	message = pb_protocol_create_message(client,
+			PB_PROTOCOL_ACTION_ADD, len);
+	if (!message)
+		return -1;
+
+	pb_protocol_serialise_device(dev, message->payload, len);
+
+	return client_write_message(server, client, message);
+}
+
+static int write_remove_message(struct discover_server *server,
+		struct client *client, char *dev_id)
+{
+	struct pb_protocol_message *message;
+	int len;
+
+	len = strlen(dev_id) + sizeof(uint32_t);
+
+	message = pb_protocol_create_message(client,
+			PB_PROTOCOL_ACTION_REMOVE, len);
+	if (!message)
+		return -1;
+
+	pb_protocol_serialise_string(message->payload, dev_id);
+
+	return client_write_message(server, client, message);
+}
+
+static int discover_server_process(void *arg)
+{
+	struct discover_server *server = arg;
+	struct client *client;
+	int fd;
+
+
+	len = sizeof(addr);
+
+	/* accept the incoming connection */
+	fd = accept(server->socket, NULL, 0);
+	if (!fd) {
+		pb_log("accept: %s\n", strerror(errno));
+		return 0;
+	}
+
+	/* add to our list of clients */
+	client = talloc(server, struct client);
+	list_add(&server->clients, &client->list);
+
+	talloc_set_destructor(client, client_destructor);
+
+	client->fd = fd;
+
+	/* send existing devices to client */
+	write_add_message(server, client, &device);
+
+	sleep(2);
+
+	write_remove_message(server, client, "1");
+
+	return 0;
+}
+
+struct discover_server *discover_server_init(void)
+{
+	struct discover_server *server;
+	struct sockaddr_un addr;
+
+	server = talloc(NULL, struct discover_server);
+	if (!server)
+		return NULL;
+
+	server->waiter = NULL;
+	list_init(&server->clients);
+
+	unlink(PB_SOCKET_PATH);
+
+	server->socket = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (server->socket < 0) {
+		pb_log("error creating server socket: %s\n", strerror(errno));
+		goto out_err;
+	}
+
+	talloc_set_destructor(server, server_destructor);
+
+	addr.sun_family = AF_UNIX;
+	strcpy(addr.sun_path, PB_SOCKET_PATH);
+
+	if (bind(server->socket, (struct sockaddr *)&addr, sizeof(addr))) {
+		pb_log("error binding server socket: %s\n", strerror(errno));
+		goto out_err;
+	}
+
+	if (listen(server->socket, 8)) {
+		pb_log("server socket listen: %s\n", strerror(errno));
+		goto out_err;
+	}
+
+	server->waiter = waiter_register(server->socket, WAIT_IN,
+			discover_server_process, server);
+
+	return server;
+
+out_err:
+	talloc_free(server);
+	return NULL;
+}
+
+void discover_server_destroy(struct discover_server *server)
+{
+	talloc_free(server);
+}
+