pipewire/src/modules/module-client-node/remote-node.c

/* PipeWire
 *
 * Copyright © 2018 Wim Taymans
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#include <time.h>
#include <sys/mman.h>

#include <spa/pod/parser.h>
#include <spa/node/utils.h>
#include <spa/debug/types.h>

#include "pipewire/pipewire.h"
#include "pipewire/private.h"

#include "extensions/protocol-native.h"
#include "extensions/client-node.h"

#define MAX_MIX	4096
#define MAX_IO	32

/** \cond */

struct buffer {
	uint32_t id;
	struct spa_buffer *buf;
	struct pw_memmap **mem;
	uint32_t n_mem;
};

struct io {
	uint32_t id;
	struct pw_memmap *mem;
};

struct mix {
	struct spa_list link;
	struct pw_port *port;
	uint32_t mix_id;
	struct pw_port_mix mix;
	struct pw_array buffers;
	bool active;
	struct io ios[MAX_IO];
};

struct link {
	uint32_t node_id;
	struct pw_memmap *map;
	struct pw_node_target target;
	int signalfd;
};

struct node_data {
	struct pw_remote *remote;
	struct pw_core *core;

	uint32_t remote_id;
	int rtwritefd;

	struct mix mix_pool[MAX_MIX];
	struct spa_list mix[2];
	struct spa_list free_mix;

	struct pw_node *node;
	struct spa_hook node_listener;
	int do_free:1;
	int have_transport:1;

        struct pw_client_node_proxy *node_proxy;
	struct spa_hook node_proxy_listener;
	struct spa_hook proxy_listener;
        struct pw_proxy *proxy;

	struct io ios[MAX_IO];
	struct spa_io_position *position;

	struct pw_array links;
};

/** \endcond */

static void init_ios(struct io *ios)
{
	int i;
	for (i = 0; i < MAX_IO; i++)
		ios[i].id = SPA_ID_INVALID;
}

static void clear_io(struct io *io)
{
	pw_log_debug("%p clear id:%u mem:%p", io, io->id, io->mem);
	pw_memmap_free(io->mem);
	io->mem = NULL;
	io->id = SPA_ID_INVALID;
}

static struct io *update_io(struct node_data *data, struct io *ios,
		uint32_t id, struct pw_memmap *mem)
{
	int i;
	struct io *io, *f = NULL;

	pw_log_debug("node %p: update id:%u mem:%p", data, id, mem);

	for (i = 0; i < MAX_IO; i++) {
		io = &ios[i];
		if (io->id == SPA_ID_INVALID && f == NULL)
			f = io;
		else if (io->id == id) {
			if (io->mem && io->mem != mem)
				clear_io(io);
			f = io;
			break;
		}
	}
	if (f == NULL)
		return NULL;

	io = f;
	io->id = id;
	io->mem = mem;

	return io;
}

static struct link *find_activation(struct pw_array *links, uint32_t node_id)
{
	struct link *l;

	pw_array_for_each(l, links) {
		if (l->node_id == node_id)
			return l;
	}
	return NULL;
}

static void clear_link(struct node_data *data, struct link *link)
{
	link->node_id = SPA_ID_INVALID;
	link->target.activation = NULL;
	pw_memmap_free(link->map);
	close(link->signalfd);
	spa_list_remove(&link->target.link);
}

static void clean_transport(struct node_data *data)
{
	struct link *l;

	if (!data->have_transport)
		return;

	pw_array_for_each(l, &data->links) {
		if (l->node_id != SPA_ID_INVALID)
			clear_link(data, l);
	}
	pw_array_clear(&data->links);

	close(data->rtwritefd);
	data->remote_id = SPA_ID_INVALID;
	data->have_transport = false;
}

static void mix_init(struct mix *mix, struct pw_port *port, uint32_t mix_id)
{
	mix->port = port;
	mix->mix_id = mix_id;
	pw_port_init_mix(port, &mix->mix);
	mix->active = false;
	pw_array_init(&mix->buffers, 32);
	pw_array_ensure_size(&mix->buffers, sizeof(struct buffer) * 64);
	init_ios(mix->ios);
}

static int
do_deactivate_mix(struct spa_loop *loop,
                bool async, uint32_t seq, const void *data, size_t size, void *user_data)
{
	struct mix *mix = user_data;
	spa_list_remove(&mix->mix.rt_link);
        return 0;
}

static int
deactivate_mix(struct node_data *data, struct mix *mix)
{
	if (mix->active) {
		pw_log_debug("node %p: mix %p deactivate", data, mix);
		pw_loop_invoke(data->core->data_loop,
                       do_deactivate_mix, SPA_ID_INVALID, NULL, 0, true, mix);
		mix->active = false;
	}
	return 0;
}

static int
do_activate_mix(struct spa_loop *loop,
                bool async, uint32_t seq, const void *data, size_t size, void *user_data)
{
	struct mix *mix = user_data;

	spa_list_append(&mix->port->rt.mix_list, &mix->mix.rt_link);
        return 0;
}

static int
activate_mix(struct node_data *data, struct mix *mix)
{
	if (!mix->active) {
		pw_log_debug("node %p: mix %p activate", data, mix);
		pw_loop_invoke(data->core->data_loop,
                       do_activate_mix, SPA_ID_INVALID, NULL, 0, false, mix);
		mix->active = true;
	}
	return 0;
}

static struct mix *find_mix(struct node_data *data,
		enum spa_direction direction, uint32_t port_id, uint32_t mix_id)
{
	struct mix *mix;

	spa_list_for_each(mix, &data->mix[direction], link) {
		if (mix->port->port_id == port_id &&
		    mix->mix_id == mix_id)
			return mix;
	}
	return NULL;
}

static struct mix *ensure_mix(struct node_data *data,
		enum spa_direction direction, uint32_t port_id, uint32_t mix_id)
{
	struct mix *mix;
	struct pw_port *port;

	if ((mix = find_mix(data, direction, port_id, mix_id)))
		return mix;

	if (spa_list_is_empty(&data->free_mix))
		return NULL;

	port = pw_node_find_port(data->node, direction, port_id);
	if (port == NULL)
		return NULL;

	mix = spa_list_first(&data->free_mix, struct mix, link);
	spa_list_remove(&mix->link);

	mix_init(mix, port, mix_id);
	spa_list_append(&data->mix[direction], &mix->link);

	return mix;
}


static int client_node_transport(void *object, uint32_t node_id,
			int readfd, int writefd)
{
	struct pw_proxy *proxy = object;
	struct node_data *data = proxy->user_data;
	struct pw_remote *remote = proxy->remote;

	clean_transport(data);

	data->have_transport = true;
	data->remote_id = node_id;

	pw_log_debug("remote-node %p: create transport with fds %d %d for node %u",
		proxy, readfd, writefd, node_id);

        data->rtwritefd = writefd;
	close(data->node->source.fd);
	data->node->source.fd = readfd;

	if (data->node->active)
		pw_client_node_proxy_set_active(data->node_proxy, true);

	pw_remote_emit_exported(remote, data->proxy->id, node_id);
	return 0;
}

static int add_node_update(struct pw_proxy *proxy, uint32_t change_mask)
{
	struct node_data *data = proxy->user_data;
	struct pw_node *node = data->node;
	struct spa_node_info ni = SPA_NODE_INFO_INIT();
	uint32_t n_params = 0;
	struct spa_pod **params = NULL;
	int res;

	if (change_mask & PW_CLIENT_NODE_UPDATE_PARAMS) {
		uint32_t i, idx, id;
		uint8_t buf[2048];
		struct spa_pod_builder b = { 0 };

		for (i = 0; i < node->info.n_params; i++) {
			struct spa_pod *param;

			id = node->info.params[i].id;

			for (idx = 0;;) {
				spa_pod_builder_init(&b, buf, sizeof(buf));
	                        if (spa_node_enum_params_sync(node->node,
							id, &idx,
							NULL, &param, &b) != 1)
	                                break;

				params = realloc(params, sizeof(struct spa_pod *) * (n_params + 1));
				params[n_params++] = spa_pod_copy(param);
			}
                }
	}
	if (change_mask & PW_CLIENT_NODE_UPDATE_INFO) {
		ni.max_input_ports = node->info.max_input_ports;
		ni.max_output_ports = node->info.max_output_ports;
		ni.change_mask = SPA_NODE_CHANGE_MASK_FLAGS |
			SPA_NODE_CHANGE_MASK_PROPS |
			SPA_NODE_CHANGE_MASK_PARAMS;
		ni.flags = 0;
		ni.props = node->info.props;
		ni.params = node->info.params;
		ni.n_params = node->info.n_params;

	}

        res = pw_client_node_proxy_update(data->node_proxy,
				change_mask,
				n_params,
				(const struct spa_pod **)params,
				&ni);

	if (params) {
		while (n_params > 0)
			free(params[--n_params]);
		free(params);
	}
	return res;
}

static int add_port_update(struct pw_proxy *proxy, struct pw_port *port, uint32_t change_mask)
{
	struct node_data *data = proxy->user_data;
	struct spa_port_info pi = SPA_PORT_INFO_INIT();
	uint32_t n_params = 0;
	struct spa_pod **params = NULL;
	int res;

	if (change_mask & PW_CLIENT_NODE_PORT_UPDATE_PARAMS) {
		uint32_t i, idx, id;
		uint8_t buf[2048];
		struct spa_pod_builder b = { 0 };

		for (i = 0; i < port->info.n_params; i++) {
			struct spa_pod *param;

			id = port->info.params[i].id;

			for (idx = 0;;) {
				spa_pod_builder_init(&b, buf, sizeof(buf));
	                        if (spa_node_port_enum_params_sync(port->node->node,
							port->direction, port->port_id,
							id, &idx,
							NULL, &param, &b) != 1)
	                                break;

				params = realloc(params, sizeof(struct spa_pod *) * (n_params + 1));
				params[n_params++] = spa_pod_copy(param);
			}
                }
	}
	if (change_mask & PW_CLIENT_NODE_PORT_UPDATE_INFO) {
		pi.change_mask = SPA_PORT_CHANGE_MASK_FLAGS |
			SPA_PORT_CHANGE_MASK_RATE |
			SPA_PORT_CHANGE_MASK_PROPS |
			SPA_PORT_CHANGE_MASK_PARAMS;
		pi.flags = port->spa_flags;
		pi.rate = SPA_FRACTION(0, 1);
		pi.props = &port->properties->dict;
		SPA_FLAG_UNSET(pi.flags,
			SPA_PORT_FLAG_CAN_ALLOC_BUFFERS | SPA_PORT_FLAG_DYNAMIC_DATA);
		pi.n_params = port->info.n_params;
		pi.params = port->info.params;
	}

	res = pw_client_node_proxy_port_update(data->node_proxy,
                                         port->direction,
                                         port->port_id,
                                         change_mask,
                                         n_params,
                                         (const struct spa_pod **)params,
					 &pi);
	if (params) {
		while (n_params > 0)
			free(params[--n_params]);
		free(params);
	}
	return res;
}

static int
client_node_set_param(void *object, uint32_t id, uint32_t flags,
		      const struct spa_pod *param)
{
	struct pw_proxy *proxy = object;
	struct node_data *data = proxy->user_data;
	return spa_node_set_param(data->node->node, id, flags, param);
}

static int
client_node_set_io(void *object,
		   uint32_t id,
		   uint32_t memid,
		   uint32_t offset,
		   uint32_t size)
{
	struct pw_proxy *proxy = object;
	struct node_data *data = proxy->user_data;
	struct pw_memmap *mm;
	void *ptr;

	if (memid == SPA_ID_INVALID) {
		size = 0;
		mm = ptr = NULL;
	}
	else {
		mm = pw_mempool_map_id(proxy->remote->pool, memid,
				PROT_READ|PROT_WRITE, offset, size);
		if (mm == NULL) {
			pw_log_warn("can't map memory id %u: %m", memid);
			return -errno;
		}
		ptr = mm->ptr;
	}

	pw_log_debug("node %p: set io %s %p", proxy,
			spa_debug_type_find_name(spa_type_io, id), ptr);

	update_io(data, data->ios, id, mm);

	switch (id) {
	case SPA_IO_Position:
		data->position = ptr;
		break;
	default:
		break;
	}

	return spa_node_set_io(data->node->node, id, ptr, size);
}

static int client_node_event(void *object, const struct spa_event *event)
{
	pw_log_warn("unhandled node event %d", SPA_EVENT_TYPE(event));
	return -ENOTSUP;
}

static int client_node_command(void *object, const struct spa_command *command)
{
	struct pw_proxy *proxy = object;
	struct node_data *data = proxy->user_data;
	int res;

	switch (SPA_NODE_COMMAND_ID(command)) {
	case SPA_NODE_COMMAND_Pause:
		pw_log_debug("node %p: pause", proxy);

		if ((res = pw_node_set_state(data->node, PW_NODE_STATE_IDLE)) < 0) {
			pw_log_warn("node %p: pause failed", proxy);
			pw_proxy_error(proxy, res, "pause failed");
		}

		break;
	case SPA_NODE_COMMAND_Start:
		pw_log_debug("node %p: start", proxy);

		if ((res = pw_node_set_state(data->node, PW_NODE_STATE_RUNNING)) < 0) {
			pw_log_warn("node %p: start failed", proxy);
			pw_proxy_error(proxy, res, "start failed");
		}
		break;
	default:
		pw_log_warn("unhandled node command %d", SPA_NODE_COMMAND_ID(command));
		res = -ENOTSUP;
		pw_proxy_error(proxy, res, "command %d not supported", SPA_NODE_COMMAND_ID(command));
	}
	return res;
}

static int
client_node_add_port(void *object, enum spa_direction direction, uint32_t port_id,
		const struct spa_dict *props)
{
	struct pw_proxy *proxy = object;
	pw_log_warn("add port not supported");
	pw_proxy_error(proxy, -ENOTSUP, "add port not supported");
	return -ENOTSUP;
}

static int
client_node_remove_port(void *object, enum spa_direction direction, uint32_t port_id)
{
	struct pw_proxy *proxy = object;
	pw_log_warn("remove port not supported");
	pw_proxy_error(proxy, -ENOTSUP, "remove port not supported");
	return -ENOTSUP;
}

static int clear_buffers(struct node_data *data, struct mix *mix)
{
	struct pw_port *port = mix->port;
        struct buffer *b;
	uint32_t i;
	int res;

        pw_log_debug("port %p: clear buffers %d", port, mix->mix_id);
	if ((res = pw_port_use_buffers(port, mix->mix_id, NULL, 0)) < 0) {
		pw_log_error("port %p: error clear buffers %s", port, spa_strerror(res));
		return res;
	}

        pw_array_for_each(b, &mix->buffers) {
		for (i = 0; i < b->n_mem; i++) {
			pw_log_debug("port %p: clear buffer %d map %p",
				port, b->id, b->mem[i]);
			pw_memmap_free(b->mem[i]);
		}
		b->n_mem = 0;
                free(b->buf);
        }
	mix->buffers.size = 0;
	return 0;
}

static int
client_node_port_set_param(void *object,
			   enum spa_direction direction, uint32_t port_id,
			   uint32_t id, uint32_t flags,
			   const struct spa_pod *param)
{
	struct pw_proxy *proxy = object;
	struct node_data *data = proxy->user_data;
	struct pw_port *port;
	int res;

	port = pw_node_find_port(data->node, direction, port_id);
	if (port == NULL) {
		res = -EINVAL;
		goto error_exit;
	}

        pw_log_debug("port %p: set param %d %p", port, id, param);

        if (id == SPA_PARAM_Format) {
		struct mix *mix;
		spa_list_for_each(mix, &data->mix[direction], link) {
			if (mix->port->port_id == port_id)
				clear_buffers(data, mix);
		}
	}

	res = pw_port_set_param(port, id, flags, param);
	if (res < 0)
		goto error_exit;

	return res;

error_exit:
        pw_log_error("port %p: set_param %d %p: %s", port, id, param, spa_strerror(res));
	pw_proxy_error(proxy, res, "port_set_param: %s", spa_strerror(res));
	return res;
}

static int
client_node_port_use_buffers(void *object,
			     enum spa_direction direction, uint32_t port_id, uint32_t mix_id,
			     uint32_t n_buffers, struct pw_client_node_buffer *buffers)
{
	struct pw_proxy *proxy = object;
	struct node_data *data = proxy->user_data;
	struct buffer *bid;
	uint32_t i, j;
	struct spa_buffer *b, **bufs;
	struct mix *mix;
	int res, prot;

	mix = ensure_mix(data, direction, port_id, mix_id);
	if (mix == NULL) {
		res = -ENOENT;
		goto error_exit;
	}

	prot = PROT_READ | (direction == SPA_DIRECTION_OUTPUT ? PROT_WRITE : 0);

	/* clear previous buffers */
	clear_buffers(data, mix);

	bufs = alloca(n_buffers * sizeof(struct spa_buffer *));

	for (i = 0; i < n_buffers; i++) {
		size_t size;
		off_t offset;
		struct pw_memmap *mm;

		mm = pw_mempool_map_id(proxy->remote->pool, buffers[i].mem_id,
				prot, buffers[i].offset, buffers[i].size);
		if (mm == NULL) {
			res = -errno;
			goto error_exit_cleanup;
		}

		bid = pw_array_add(&mix->buffers, sizeof(struct buffer));
		if (bid == NULL) {
			res = -errno;
			goto error_exit_cleanup;
		}
		bid->id = i;

		if (mlock(mm->ptr, mm->size) < 0)
			pw_log_warn("Failed to mlock memory %p %u: %m",
					mm->ptr, mm->size);

		size = sizeof(struct spa_buffer);
		size += sizeof(struct pw_memmap *);
		for (j = 0; j < buffers[i].buffer->n_metas; j++)
			size += sizeof(struct spa_meta);
		for (j = 0; j < buffers[i].buffer->n_datas; j++) {
			size += sizeof(struct spa_data);
			size += sizeof(struct pw_memmap *);
		}

		b = bid->buf = malloc(size);
		if (b == NULL) {
			res = -errno;
			goto error_exit_cleanup;
		}
		memcpy(b, buffers[i].buffer, sizeof(struct spa_buffer));

		b->metas = SPA_MEMBER(b, sizeof(struct spa_buffer), struct spa_meta);
		b->datas = SPA_MEMBER(b->metas, sizeof(struct spa_meta) * b->n_metas,
				       struct spa_data);
		bid->mem = SPA_MEMBER(b->datas, sizeof(struct spa_data) * b->n_datas,
			       struct pw_memmap *);
		bid->n_mem = 0;
		bid->mem[bid->n_mem++] = mm;

		pw_log_debug("add buffer %d %d %u %u", mm->block->id,
				bid->id, buffers[i].offset, buffers[i].size);

		offset = 0;
		for (j = 0; j < b->n_metas; j++) {
			struct spa_meta *m = &b->metas[j];
			memcpy(m, &buffers[i].buffer->metas[j], sizeof(struct spa_meta));
			m->data = SPA_MEMBER(mm->ptr, offset, void);
			offset += SPA_ROUND_UP_N(m->size, 8);
		}

		for (j = 0; j < b->n_datas; j++) {
			struct spa_data *d = &b->datas[j];

			memcpy(d, &buffers[i].buffer->datas[j], sizeof(struct spa_data));
			d->chunk =
			    SPA_MEMBER(mm->ptr, offset + sizeof(struct spa_chunk) * j,
				       struct spa_chunk);

			if (d->type == SPA_DATA_MemId) {
				uint32_t mem_id = SPA_PTR_TO_UINT32(d->data);
				struct pw_memblock *bm;

				bm = pw_mempool_find_id(proxy->remote->pool, mem_id);
				if (bm == NULL) {
					pw_log_error("unknown buffer mem %u", mem_id);
					res = -ENODEV;
					goto error_exit_cleanup;
				}

				d->fd = bm->fd;
				d->type = bm->type;
				d->data = NULL;

				pw_log_debug(" data %d %u -> fd %d maxsize %d",
						j, bm->id, bm->fd, d->maxsize);
			} else if (d->type == SPA_DATA_MemPtr) {
				int offs = SPA_PTR_TO_INT(d->data);
				d->data = SPA_MEMBER(mm->ptr, offs, void);
				d->fd = -1;
				pw_log_debug(" data %d %u -> mem %p maxsize %d",
						j, bid->id, d->data, d->maxsize);
			} else {
				pw_log_warn("unknown buffer data type %d", d->type);
			}
		}
		bufs[i] = b;
	}

	if ((res = pw_port_use_buffers(mix->port, mix->mix_id, bufs, n_buffers)) < 0)
		goto error_exit_cleanup;

	return res;

error_exit_cleanup:
	clear_buffers(data, mix);
error_exit:
        pw_log_error("port %p: use_buffers: %s", mix, spa_strerror(res));
	pw_proxy_error(proxy, res, "port_use_buffers error: %s", spa_strerror(res));
	return res;
}

static int
client_node_port_set_io(void *object,
                        uint32_t direction,
                        uint32_t port_id,
                        uint32_t mix_id,
                        uint32_t id,
                        uint32_t memid,
                        uint32_t offset,
                        uint32_t size)
{
	struct pw_proxy *proxy = object;
	struct node_data *data = proxy->user_data;
	struct mix *mix;
	struct pw_memmap *mm;
	void *ptr;
	int res = 0;

	mix = ensure_mix(data, direction, port_id, mix_id);
	if (mix == NULL) {
		res = -ENOENT;
		goto error_exit;
	}

	if (memid == SPA_ID_INVALID) {
		mm = ptr = NULL;
		size = 0;
	}
	else {
		mm = pw_mempool_map_id(proxy->remote->pool, memid,
				PROT_READ|PROT_WRITE, offset, size);
		if (mm == NULL) {
			res = -errno;
			goto error_exit;
		}
		ptr = mm->ptr;
	}

	pw_log_debug("port %p: set io:%s new:%p old:%p", mix->port,
			spa_debug_type_find_name(spa_type_io, id), ptr, mix->mix.io);

	update_io(data, mix->ios, id, mm);

	if (id == SPA_IO_Buffers) {
		if (ptr == NULL && mix->mix.io)
			deactivate_mix(data, mix);
		mix->mix.io = ptr;
		if (ptr)
			activate_mix(data, mix);
	}

	if ((res = spa_node_port_set_io(mix->port->mix,
			     direction, mix_id,
			     id, ptr, size)) < 0) {
		if (res == -ENOTSUP)
			res = 0;
		else
			goto error_exit;
	}
	return res;

error_exit:
        pw_log_error("port %p: set_io: %s", mix, spa_strerror(res));
	pw_proxy_error(proxy, res, "port_set_io failed: %s", spa_strerror(res));
	return res;
}

static int link_signal_func(void *user_data)
{
	struct link *link = user_data;
	uint64_t cmd = 1;
	struct timespec ts;

	pw_log_trace("link %p: signal", link);

	clock_gettime(CLOCK_MONOTONIC, &ts);
	link->target.activation->status = TRIGGERED;
	link->target.activation->signal_time = SPA_TIMESPEC_TO_NSEC(&ts);

	if (write(link->signalfd, &cmd, sizeof(cmd)) != sizeof(cmd))
		pw_log_warn("link %p: write failed %m", link);
	return 0;
}

static int
client_node_set_activation(void *object,
                        uint32_t node_id,
                        int signalfd,
                        uint32_t memid,
                        uint32_t offset,
                        uint32_t size)
{
	struct pw_proxy *proxy = object;
	struct node_data *data = proxy->user_data;
	struct pw_node *node = data->node;
	struct pw_memmap *mm;
	struct pw_node_activation *ptr;
	struct link *link;
	int res = 0;

	if (memid == SPA_ID_INVALID) {
		ptr = NULL;
		mm = NULL;
		size = 0;
	}
	else {
		mm = pw_mempool_map_id(proxy->remote->pool, memid,
				PROT_READ|PROT_WRITE, offset, size);
		if (mm == NULL) {
			res = -errno;
			goto error_exit;
		}
		ptr = mm->ptr;
	}
	pw_log_debug("node %p: set activation %d %p %u %u", node, node_id, ptr, offset, size);

	if (data->remote_id == node_id) {
		pw_log_debug("node %p: our activation %u: %u %u %u %p", node, node_id,
				memid, offset, size, ptr);
		close(signalfd);
		return 0;
	}

	if (ptr) {
		link = pw_array_add(&data->links, sizeof(struct link));
		if (link == NULL) {
			res = -errno;
			goto error_exit;
		}
		link->node_id = node_id;
		link->map = mm;
		link->target.activation = ptr;
		link->signalfd = signalfd;
		link->target.signal = link_signal_func;
		link->target.data = link;
		link->target.node = NULL;
		spa_list_append(&node->rt.target_list, &link->target.link);

		pw_log_debug("node %p: link %p: fd:%d id:%u state %p required %d, pending %d",
				node, link, signalfd,
				link->target.activation->position.clock.id,
				&link->target.activation->state[0],
				link->target.activation->state[0].required,
				link->target.activation->state[0].pending);
	} else {
		link = find_activation(&data->links, node_id);
		if (link == NULL) {
			res = -ENOENT;
			goto error_exit;
		}
		clear_link(data, link);
	}
	return res;

error_exit:
	pw_log_error("node %p: set activation %d: %s", node, node_id, spa_strerror(res));
	pw_proxy_error(proxy, res, "set_activation: %s", spa_strerror(res));
	return res;
}

static const struct pw_client_node_proxy_events client_node_events = {
	PW_VERSION_CLIENT_NODE_PROXY_EVENTS,
	.transport = client_node_transport,
	.set_param = client_node_set_param,
	.set_io = client_node_set_io,
	.event = client_node_event,
	.command = client_node_command,
	.add_port = client_node_add_port,
	.remove_port = client_node_remove_port,
	.port_set_param = client_node_port_set_param,
	.port_use_buffers = client_node_port_use_buffers,
	.port_set_io = client_node_port_set_io,
	.set_activation = client_node_set_activation,
};

static void do_node_init(struct pw_proxy *proxy)
{
	struct node_data *data = proxy->user_data;
	struct pw_port *port;

	pw_log_debug("%p: init", data);
	add_node_update(proxy, PW_CLIENT_NODE_UPDATE_PARAMS |
				PW_CLIENT_NODE_UPDATE_INFO);

	spa_list_for_each(port, &data->node->input_ports, link) {
		add_port_update(proxy, port,
				PW_CLIENT_NODE_PORT_UPDATE_PARAMS |
				PW_CLIENT_NODE_PORT_UPDATE_INFO);
	}
	spa_list_for_each(port, &data->node->output_ports, link) {
		add_port_update(proxy, port,
				PW_CLIENT_NODE_PORT_UPDATE_PARAMS |
				PW_CLIENT_NODE_PORT_UPDATE_INFO);
	}
}

static void clear_mix(struct node_data *data, struct mix *mix)
{
	deactivate_mix(data, mix);

	spa_list_remove(&mix->link);

	clear_buffers(data, mix);
	pw_array_clear(&mix->buffers);

	spa_list_remove(&mix->mix.link);
	spa_list_append(&data->free_mix, &mix->link);
}

static void clean_node(struct node_data *d)
{
	struct mix *mix, *tmp;

	if (d->remote_id != SPA_ID_INVALID) {
		spa_list_for_each_safe(mix, tmp, &d->mix[SPA_DIRECTION_INPUT], link)
			clear_mix(d, mix);
		spa_list_for_each_safe(mix, tmp, &d->mix[SPA_DIRECTION_OUTPUT], link)
			clear_mix(d, mix);
	}
	clean_transport(d);
}

static void node_destroy(void *data)
{
	struct node_data *d = data;

	pw_log_debug("%p: destroy", d);

	clean_node(d);
}

static void node_free(void *data)
{
	struct node_data *d = data;

	pw_log_debug("%p: free", d);

	if (d->proxy) {
		pw_proxy_destroy(d->proxy);
		d->proxy = NULL;
	}
	pw_proxy_destroy((struct pw_proxy*)d->node_proxy);
}

static void node_info_changed(void *data, const struct pw_node_info *info)
{
	struct node_data *d = data;
	uint32_t change_mask = 0;

	pw_log_debug("info changed %p", d);

	if (info->change_mask & PW_NODE_CHANGE_MASK_PROPS)
		change_mask |= PW_CLIENT_NODE_UPDATE_INFO;
	if (info->change_mask & PW_NODE_CHANGE_MASK_PARAMS) {
		change_mask |= PW_CLIENT_NODE_UPDATE_PARAMS;
		change_mask |= PW_CLIENT_NODE_UPDATE_INFO;
	}
	add_node_update((struct pw_proxy*)d->node_proxy, change_mask);
}

static void node_port_info_changed(void *data, struct pw_port *port,
		const struct pw_port_info *info)
{
	struct node_data *d = data;
	uint32_t change_mask = 0;

	pw_log_debug("info changed %p", d);

	if (info->change_mask & PW_PORT_CHANGE_MASK_PROPS)
		change_mask |= PW_CLIENT_NODE_PORT_UPDATE_INFO;
	if (info->change_mask & PW_PORT_CHANGE_MASK_PARAMS) {
		change_mask |= PW_CLIENT_NODE_PORT_UPDATE_PARAMS;
		change_mask |= PW_CLIENT_NODE_PORT_UPDATE_INFO;
	}
	add_port_update((struct pw_proxy*)d->node_proxy, port, change_mask);
}

static void node_active_changed(void *data, bool active)
{
	struct node_data *d = data;
	pw_log_debug("active %d", active);
	pw_client_node_proxy_set_active(d->node_proxy, active);
}


static const struct pw_node_events node_events = {
	PW_VERSION_NODE_EVENTS,
	.destroy = node_destroy,
	.free = node_free,
	.info_changed = node_info_changed,
	.port_info_changed = node_port_info_changed,
	.active_changed = node_active_changed,
};

static void node_proxy_destroy(void *_data)
{
	struct node_data *data = _data;

	pw_log_debug("%p: destroy", data);

	clean_node(data);

	spa_hook_remove(&data->node_listener);

	data->node_proxy = NULL;

	if (data->proxy) {
		pw_proxy_destroy(data->proxy);
		data->proxy = NULL;
	}
	if (data->do_free)
		pw_node_destroy(data->node);
}

static const struct pw_proxy_events proxy_events = {
	PW_VERSION_PROXY_EVENTS,
	.destroy = node_proxy_destroy,
};

static int node_ready(void *d, int status)
{
	struct node_data *data = d;
	struct pw_node *node = data->node;
	struct timespec ts;
	struct pw_port *p;
	uint64_t cmd = 1;

	pw_log_trace("node %p: ready driver:%d exported:%d status:%d", node,
			node->driver, node->exported, status);

	if (status == SPA_STATUS_HAVE_BUFFER) {
		spa_list_for_each(p, &node->rt.output_mix, rt.node_link)
			spa_node_process(p->mix);
	}

	clock_gettime(CLOCK_MONOTONIC, &ts);
	node->rt.activation->status = TRIGGERED;
	node->rt.activation->signal_time = SPA_TIMESPEC_TO_NSEC(&ts);

	if (write(data->rtwritefd, &cmd, sizeof(cmd)) != sizeof(cmd))
		pw_log_warn("node %p: write failed %m", node);

	return 0;
}

static int node_reuse_buffer(void *data, uint32_t port_id, uint32_t buffer_id)
{
	return 0;
}

static const struct spa_node_callbacks node_callbacks = {
	SPA_VERSION_NODE_CALLBACKS,
	.ready = node_ready,
	.reuse_buffer = node_reuse_buffer
};

static struct pw_proxy *node_export(struct pw_remote *remote, void *object, bool do_free,
		size_t user_data_size)
{
	struct pw_node *node = object;
	struct pw_proxy *proxy;
	struct node_data *data;
	int i;

	proxy = pw_core_proxy_create_object(remote->core_proxy,
					    "client-node",
					    PW_TYPE_INTERFACE_ClientNode,
					    PW_VERSION_CLIENT_NODE,
					    &node->properties->dict,
					    sizeof(struct node_data));
        if (proxy == NULL)
                return NULL;

	data = pw_proxy_get_user_data(proxy);
	data->remote = remote;
	data->node = node;
	data->do_free = do_free;
	data->core = pw_node_get_core(node);
	data->node_proxy = (struct pw_client_node_proxy *)proxy;
	data->remote_id = SPA_ID_INVALID;
	init_ios(data->ios);

	node->exported = true;

	spa_list_init(&data->free_mix);
	spa_list_init(&data->mix[0]);
	spa_list_init(&data->mix[1]);
	for (i = 0; i < MAX_MIX; i++)
		spa_list_append(&data->free_mix, &data->mix_pool[i].link);

        pw_array_init(&data->links, 64);
        pw_array_ensure_size(&data->links, sizeof(struct link) * 64);

	pw_proxy_add_listener(proxy, &data->proxy_listener, &proxy_events, data);
	spa_node_set_callbacks(node->node, &node_callbacks, data);
	pw_node_add_listener(node, &data->node_listener, &node_events, data);

        pw_client_node_proxy_add_listener(data->node_proxy,
					  &data->node_proxy_listener,
					  &client_node_events,
					  proxy);
        do_node_init(proxy);

	data->proxy = (struct pw_proxy*) pw_client_node_proxy_get_node(data->node_proxy,
			PW_VERSION_NODE_PROXY, user_data_size);

	return data->proxy;
}

struct pw_proxy *pw_remote_node_export(struct pw_remote *remote,
		uint32_t type, struct pw_properties *props, void *object,
		size_t user_data_size)
{
	return node_export(remote, object, false, user_data_size);
}

struct pw_proxy *pw_remote_spa_node_export(struct pw_remote *remote,
		uint32_t type, struct pw_properties *props, void *object,
		size_t user_data_size)
{
	struct pw_node *node;

	node = pw_node_new(pw_remote_get_core(remote), NULL, props, 0);
	if (node == NULL)
		return NULL;

	pw_node_set_implementation(node, (struct spa_node*)object);
	pw_node_register(node, NULL, NULL, NULL);
	pw_node_set_active(node, true);

	return node_export(remote, node, true, user_data_size);
}