source: mainline/uspace/srv/net/udp/service.c@ ca48672

/*
 * Copyright (c) 2025 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup udp
 * @{
 */

/**
 * @file HelenOS service implementation
 */

#include <async.h>
#include <errno.h>
#include <inet/endpoint.h>
#include <io/log.h>
#include <ipc/services.h>
#include <ipc/udp.h>
#include <loc.h>
#include <macros.h>
#include <stdlib.h>

#include "assoc.h"
#include "cassoc.h"
#include "msg.h"
#include "service.h"
#include "udp_type.h"

#define NAME "udp"

/** Maximum message size */
#define MAX_MSG_SIZE DATA_XFER_LIMIT

static void udp_recv_msg_cassoc(void *, inet_ep2_t *, udp_msg_t *);

/** Callbacks to tie us to association layer */
static udp_assoc_cb_t udp_cassoc_cb = {
        .recv_msg = udp_recv_msg_cassoc
};

/** Send 'data' event to client.
 *
 * @param client Client
 */
static void udp_ev_data(udp_client_t *client)
{
        async_exch_t *exch;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_ev_data()");

        exch = async_exchange_begin(client->sess);
        aid_t req = async_send_0(exch, UDP_EV_DATA, NULL);
        async_exchange_end(exch);

        async_forget(req);
}

/** Message received on client association.
 *
 * Used as udp_assoc_cb.recv_msg callback.
 *
 * @param arg Callback argument, client association
 * @param epp Endpoint pair where message was received
 * @param msg Message
 */
static void udp_recv_msg_cassoc(void *arg, inet_ep2_t *epp, udp_msg_t *msg)
{
        udp_cassoc_t *cassoc = (udp_cassoc_t *) arg;

        udp_cassoc_queue_msg(cassoc, epp, msg);
        udp_ev_data(cassoc->client);
}

/** Create association.
 *
 * Handle client request to create association (with parameters unmarshalled).
 *
 * @param client    UDP client
 * @param epp       Endpoint pair
 * @param rassoc_id Place to store ID of new association
 *
 * @return EOK on success or an error code
 */
static errno_t udp_assoc_create_impl(udp_client_t *client, inet_ep2_t *epp,
    sysarg_t *rassoc_id)
{
        udp_assoc_t *assoc;
        udp_cassoc_t *cassoc;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_assoc_create_impl");

        assoc = udp_assoc_new(epp, NULL, NULL);
        if (assoc == NULL)
                return EIO;

        if (epp->local_link != 0)
                udp_assoc_set_iplink(assoc, epp->local_link);

        rc = udp_cassoc_create(client, assoc, &cassoc);
        if (rc != EOK) {
                assert(rc == ENOMEM);
                udp_assoc_delete(assoc);
                return ENOMEM;
        }

        assoc->cb = &udp_cassoc_cb;
        assoc->cb_arg = cassoc;

        rc = udp_assoc_add(assoc);
        if (rc != EOK) {
                udp_cassoc_destroy(cassoc);
                udp_assoc_delete(assoc);
                return rc;
        }

        *rassoc_id = cassoc->id;
        return EOK;
}

/** Destroy association.
 *
 * Handle client request to destroy association (with parameters unmarshalled).
 *
 * @param client   UDP client
 * @param assoc_id Association ID
 * @return EOK on success, ENOENT if no such association is found
 */
static errno_t udp_assoc_destroy_impl(udp_client_t *client, sysarg_t assoc_id)
{
        udp_cassoc_t *cassoc;
        errno_t rc;

        rc = udp_cassoc_get(client, assoc_id, &cassoc);
        if (rc != EOK) {
                assert(rc == ENOENT);
                return ENOENT;
        }

        udp_assoc_remove(cassoc->assoc);
        udp_assoc_reset(cassoc->assoc);
        udp_assoc_delete(cassoc->assoc);
        udp_cassoc_destroy(cassoc);
        return EOK;
}

/** Set association sending messages with no local address.
 *
 * Handle client request to set nolocal flag (with parameters unmarshalled).
 *
 * @param client   UDP client
 * @param assoc_id Association ID
 * @return EOK on success, ENOENT if no such association is found
 */
static errno_t udp_assoc_set_nolocal_impl(udp_client_t *client, sysarg_t assoc_id)
{
        udp_cassoc_t *cassoc;
        errno_t rc;

        rc = udp_cassoc_get(client, assoc_id, &cassoc);
        if (rc != EOK) {
                assert(rc == ENOENT);
                return ENOENT;
        }

        log_msg(LOG_DEFAULT, LVL_NOTE, "Setting nolocal to true");
        cassoc->assoc->nolocal = true;
        return EOK;
}

/** Send message via association.
 *
 * Handle client request to send message (with parameters unmarshalled).
 *
 * @param client   UDP client
 * @param assoc_id Association ID
 * @param dest     Destination endpoint or @c NULL to use the default from
 *                 association
 * @param data     Message data
 * @param size     Message size
 *
 * @return EOK on success or an error code
 */
static errno_t udp_assoc_send_msg_impl(udp_client_t *client, sysarg_t assoc_id,
    inet_ep_t *dest, void *data, size_t size)
{
        udp_msg_t msg;
        udp_cassoc_t *cassoc;
        errno_t rc;

        rc = udp_cassoc_get(client, assoc_id, &cassoc);
        if (rc != EOK)
                return rc;

        msg.data = data;
        msg.data_size = size;
        rc = udp_assoc_send(cassoc->assoc, dest, &msg);
        if (rc != EOK)
                return rc;

        return EOK;
}

/** Create callback session.
 *
 * Handle client request to create callback session.
 *
 * @param client UDP client
 * @param icall  Async request data
 *
 */
static void udp_callback_create_srv(udp_client_t *client, ipc_call_t *icall)
{
        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_callback_create_srv()");

        async_sess_t *sess = async_callback_receive(EXCHANGE_SERIALIZE);
        if (sess == NULL) {
                async_answer_0(icall, ENOMEM);
                return;
        }

        client->sess = sess;
        async_answer_0(icall, EOK);
}

/** Create association.
 *
 * Handle client request to create association.
 *
 * @param client UDP client
 * @param icall  Async request data
 *
 */
static void udp_assoc_create_srv(udp_client_t *client, ipc_call_t *icall)
{
        ipc_call_t call;
        size_t size;
        inet_ep2_t epp;
        sysarg_t assoc_id;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_assoc_create_srv()");

        if (!async_data_write_receive(&call, &size)) {
                async_answer_0(&call, EREFUSED);
                async_answer_0(icall, EREFUSED);
                return;
        }

        if (size != sizeof(inet_ep2_t)) {
                async_answer_0(&call, EINVAL);
                async_answer_0(icall, EINVAL);
                return;
        }

        rc = async_data_write_finalize(&call, &epp, size);
        if (rc != EOK) {
                async_answer_0(&call, rc);
                async_answer_0(icall, rc);
                return;
        }

        rc = udp_assoc_create_impl(client, &epp, &assoc_id);
        if (rc != EOK) {
                async_answer_0(icall, rc);
                return;
        }

        async_answer_1(icall, EOK, assoc_id);
}

/** Destroy association.
 *
 * Handle client request to destroy association.
 *
 * @param client UDP client
 * @param icall  Async request data
 *
 */
static void udp_assoc_destroy_srv(udp_client_t *client, ipc_call_t *icall)
{
        sysarg_t assoc_id;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_assoc_destroy_srv()");

        assoc_id = ipc_get_arg1(icall);
        rc = udp_assoc_destroy_impl(client, assoc_id);
        async_answer_0(icall, rc);
}

/** Set association with no local address.
 *
 * Handle client request to set no local address flag.
 *
 * @param client UDP client
 * @param icall  Async request data
 *
 */
static void udp_assoc_set_nolocal_srv(udp_client_t *client, ipc_call_t *icall)
{
        sysarg_t assoc_id;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_NOTE, "udp_assoc_set_nolocal_srv()");

        assoc_id = ipc_get_arg1(icall);
        rc = udp_assoc_set_nolocal_impl(client, assoc_id);
        async_answer_0(icall, rc);
}

/** Send message via association.
 *
 * Handle client request to send message.
 *
 * @param client UDP client
 * @param icall  Async request data
 *
 */
static void udp_assoc_send_msg_srv(udp_client_t *client, ipc_call_t *icall)
{
        ipc_call_t call;
        size_t size;
        inet_ep_t dest;
        sysarg_t assoc_id;
        void *data;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_assoc_send_msg_srv()");

        /* Receive dest */

        if (!async_data_write_receive(&call, &size)) {
                async_answer_0(&call, EREFUSED);
                async_answer_0(icall, EREFUSED);
                return;
        }

        if (size != sizeof(inet_ep_t)) {
                async_answer_0(&call, EINVAL);
                async_answer_0(icall, EINVAL);
                return;
        }

        rc = async_data_write_finalize(&call, &dest, size);
        if (rc != EOK) {
                async_answer_0(&call, rc);
                async_answer_0(icall, rc);
                return;
        }

        /* Receive message data */

        if (!async_data_write_receive(&call, &size)) {
                async_answer_0(&call, EREFUSED);
                async_answer_0(icall, EREFUSED);
                return;
        }

        if (size > MAX_MSG_SIZE) {
                async_answer_0(&call, EINVAL);
                async_answer_0(icall, EINVAL);
                return;
        }

        data = malloc(size);
        if (data == NULL) {
                async_answer_0(&call, ENOMEM);
                async_answer_0(icall, ENOMEM);
        }

        rc = async_data_write_finalize(&call, data, size);
        if (rc != EOK) {
                async_answer_0(&call, rc);
                async_answer_0(icall, rc);
                free(data);
                return;
        }

        assoc_id = ipc_get_arg1(icall);

        rc = udp_assoc_send_msg_impl(client, assoc_id, &dest, data, size);
        if (rc != EOK) {
                async_answer_0(icall, rc);
                free(data);
                return;
        }

        async_answer_0(icall, EOK);
        free(data);
}

/** Get next received message.
 *
 * @param client UDP Client
 * @return Pointer to queue entry for next received message
 */
static udp_crcv_queue_entry_t *udp_rmsg_get_next(udp_client_t *client)
{
        link_t *link;

        link = list_first(&client->crcv_queue);
        if (link == NULL)
                return NULL;

        return list_get_instance(link, udp_crcv_queue_entry_t, link);
}

/** Get info on first received message.
 *
 * Handle client request to get information on received message.
 *
 * @param client UDP client
 * @param icall  Async request data
 *
 */
static void udp_rmsg_info_srv(udp_client_t *client, ipc_call_t *icall)
{
        ipc_call_t call;
        size_t size;
        udp_crcv_queue_entry_t *enext;
        sysarg_t assoc_id;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_rmsg_info_srv()");
        enext = udp_rmsg_get_next(client);

        if (!async_data_read_receive(&call, &size)) {
                async_answer_0(&call, EREFUSED);
                async_answer_0(icall, EREFUSED);
                return;
        }

        if (enext == NULL) {
                async_answer_0(&call, ENOENT);
                async_answer_0(icall, ENOENT);
                return;
        }

        rc = async_data_read_finalize(&call, &enext->epp.remote,
            max(size, (size_t)sizeof(inet_ep_t)));
        if (rc != EOK) {
                async_answer_0(icall, rc);
                return;
        }

        assoc_id = enext->cassoc->id;
        size = enext->msg->data_size;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_rmsg_info_srv(): assoc_id=%zu, "
            "size=%zu", assoc_id, size);
        async_answer_2(icall, EOK, assoc_id, size);
}

/** Read data from first received message.
 *
 * Handle client request to read data from first received message.
 *
 * @param client UDP client
 * @param icall  Async request data
 *
 */
static void udp_rmsg_read_srv(udp_client_t *client, ipc_call_t *icall)
{
        ipc_call_t call;
        size_t msg_size;
        udp_crcv_queue_entry_t *enext;
        void *data;
        size_t size;
        size_t off;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_rmsg_read_srv()");
        off = ipc_get_arg1(icall);

        enext = udp_rmsg_get_next(client);

        if (!async_data_read_receive(&call, &size)) {
                async_answer_0(&call, EREFUSED);
                async_answer_0(icall, EREFUSED);
                return;
        }

        if (enext == NULL) {
                async_answer_0(&call, ENOENT);
                async_answer_0(icall, ENOENT);
                return;
        }

        data = enext->msg->data + off;
        msg_size = enext->msg->data_size;

        if (off > msg_size) {
                async_answer_0(&call, EINVAL);
                async_answer_0(icall, EINVAL);
                return;
        }

        rc = async_data_read_finalize(&call, data, min(msg_size - off, size));
        if (rc != EOK) {
                async_answer_0(icall, rc);
                return;
        }

        async_answer_0(icall, EOK);
        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_rmsg_read_srv(): OK");
}

/** Discard first received message.
 *
 * Handle client request to discard first received message, advancing
 * to the next one.
 *
 * @param client UDP client
 * @param icall  Async request data
 *
 */
static void udp_rmsg_discard_srv(udp_client_t *client, ipc_call_t *icall)
{
        udp_crcv_queue_entry_t *enext;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_rmsg_discard_srv()");

        enext = udp_rmsg_get_next(client);
        if (enext == NULL) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "usg_rmsg_discard_srv: enext==NULL");
                async_answer_0(icall, ENOENT);
                return;
        }

        list_remove(&enext->link);
        udp_msg_delete(enext->msg);
        free(enext);
        async_answer_0(icall, EOK);
}

/** Handle UDP client connection.
 *
 * @param icall Connect call data
 * @param arg   Connection argument
 *
 */
static void udp_client_conn(ipc_call_t *icall, void *arg)
{
        udp_client_t client;
        unsigned long n;

        /* Accept the connection */
        async_accept_0(icall);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_client_conn()");

        client.sess = NULL;
        list_initialize(&client.cassoc);
        list_initialize(&client.crcv_queue);

        while (true) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_client_conn: wait req");
                ipc_call_t call;
                async_get_call(&call);
                sysarg_t method = ipc_get_imethod(&call);

                log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_client_conn: method=%d",
                    (int)method);
                if (!method) {
                        /* The other side has hung up */
                        async_answer_0(&call, EOK);
                        break;
                }

                switch (method) {
                case UDP_CALLBACK_CREATE:
                        udp_callback_create_srv(&client, &call);
                        break;
                case UDP_ASSOC_CREATE:
                        udp_assoc_create_srv(&client, &call);
                        break;
                case UDP_ASSOC_DESTROY:
                        udp_assoc_destroy_srv(&client, &call);
                        break;
                case UDP_ASSOC_SET_NOLOCAL:
                        udp_assoc_set_nolocal_srv(&client, &call);
                        break;
                case UDP_ASSOC_SEND_MSG:
                        udp_assoc_send_msg_srv(&client, &call);
                        break;
                case UDP_RMSG_INFO:
                        udp_rmsg_info_srv(&client, &call);
                        break;
                case UDP_RMSG_READ:
                        udp_rmsg_read_srv(&client, &call);
                        break;
                case UDP_RMSG_DISCARD:
                        udp_rmsg_discard_srv(&client, &call);
                        break;
                default:
                        async_answer_0(&call, ENOTSUP);
                        break;
                }
        }

        log_msg(LOG_DEFAULT, LVL_DEBUG, "udp_client_conn: terminated");

        n = list_count(&client.cassoc);
        if (n != 0) {
                log_msg(LOG_DEFAULT, LVL_WARN, "udp_client_conn: "
                    "Client with %lu active associations closed session.", n);
                /* XXX Clean up */
        }

        /* XXX Clean up client receive queue */

        if (client.sess != NULL)
                async_hangup(client.sess);
}

/** Initialize UDP service.
 *
 * @return EOK on success or an error code.
 */
errno_t udp_service_init(void)
{
        errno_t rc;
        service_id_t sid;
        loc_srv_t *srv;

        async_set_fallback_port_handler(udp_client_conn, NULL);

        rc = loc_server_register(NAME, &srv);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed registering server.");
                return EIO;
        }

        rc = loc_service_register(srv, SERVICE_NAME_UDP, fallback_port_id,
            &sid);
        if (rc != EOK) {
                loc_server_unregister(srv);
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed registering service.");
                return EIO;
        }

        return EOK;
}

/**
 * @}
 */