// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "eth-client.h"

#include <fuchsia/hardware/ethernet/c/fidl.h>
#include <zircon/syscalls.h>

#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#if 0
#define IORING_TRACE(fmt...) fprintf(stderr, fmt)
#else
#define IORING_TRACE(fmt...) do {} while (0)
#endif

void eth_destroy(eth_client_t* eth) {
    zx_handle_close(eth->rx_fifo);
    zx_handle_close(eth->tx_fifo);
    free(eth);
}

zx_status_t eth_create(zx_handle_t svc, zx_handle_t io_vmo, void* io_mem, eth_client_t** out) {
    eth_client_t* eth;

    if ((eth = calloc(1, sizeof(*eth))) == NULL) {
        return ZX_ERR_NO_MEMORY;
    }

    fuchsia_hardware_ethernet_Fifos fifos;
    zx_status_t status, call_status;

    status = fuchsia_hardware_ethernet_DeviceGetFifos(svc, &call_status, &fifos);
    if (status != ZX_OK || call_status != ZX_OK) {
        fprintf(stderr, "eth_create: failed to get fifos: %d, %d\n", status, call_status);
        return status == ZX_OK ? call_status : status;
    }

    zx_handle_t vmo;
    if ((status = zx_handle_duplicate(io_vmo, ZX_RIGHT_SAME_RIGHTS, &vmo)) < 0) {
        fprintf(stderr, "eth_create: failed to duplicate vmo\n");
        goto fail;
    }
    status = fuchsia_hardware_ethernet_DeviceSetIOBuffer(svc, vmo, &call_status);
    if (status != ZX_OK || call_status != ZX_OK) {
        fprintf(stderr, "eth_create: failed to set iobuf: %d, %d\n", status, call_status);
        if (status == ZX_OK) {
            status = call_status;
        }
        goto fail;
    }
    status = fuchsia_hardware_ethernet_DeviceSetClientName(svc, "netsvc", 6, &call_status);
    if (status != ZX_OK || call_status != ZX_OK) {
        fprintf(stderr, "eth_create: failed to set client name %d, %d\n", status, call_status);
    }

    eth->tx_fifo = fifos.tx;
    eth->rx_fifo = fifos.rx;
    eth->rx_size = fifos.rx_depth;
    eth->tx_size = fifos.tx_depth;
    eth->iobuf = io_mem;

    *out = eth;
    return ZX_OK;

fail:
    zx_handle_close(fifos.tx);
    zx_handle_close(fifos.rx);
    eth_destroy(eth);
    return status;
}

zx_status_t eth_queue_tx(eth_client_t* eth, void* cookie,
                         void* data, size_t len, uint32_t options) {
    fuchsia_hardware_ethernet_FifoEntry e = {
        .offset = data - eth->iobuf,
        .length = len,
        .flags = options,
        .cookie = (uint64_t)cookie,
    };
    IORING_TRACE("eth:tx+ c=%p o=%u l=%u f=%u\n",
                 e.cookie, e.offset, e.length, e.flags);
    return zx_fifo_write(eth->tx_fifo, sizeof(e), &e, 1, NULL);
}

zx_status_t eth_queue_rx(eth_client_t* eth, void* cookie,
                         void* data, size_t len, uint32_t options) {
    fuchsia_hardware_ethernet_FifoEntry e = {
        .offset = data - eth->iobuf,
        .length = len,
        .flags = options,
        .cookie = (uint64_t)cookie,
    };
    IORING_TRACE("eth:rx+ c=%p o=%u l=%u f=%u\n",
                 e.cookie, e.offset, e.length, e.flags);
    return zx_fifo_write(eth->rx_fifo, sizeof(e), &e, 1, NULL);
}

zx_status_t eth_complete_tx(eth_client_t* eth, void* ctx,
                            void (*func)(void* ctx, void* cookie)) {
    fuchsia_hardware_ethernet_FifoEntry entries[eth->tx_size];
    zx_status_t status;
    size_t count;
    if ((status = zx_fifo_read(eth->tx_fifo, sizeof(entries[0]), entries, countof(entries), &count)) < 0) {
        if (status == ZX_ERR_SHOULD_WAIT) {
            return ZX_OK;
        } else {
            return status;
        }
    }

    for (fuchsia_hardware_ethernet_FifoEntry* e = entries; count-- > 0; e++) {
        IORING_TRACE("eth:tx- c=%p o=%u l=%u f=%u\n",
                     e->cookie, e->offset, e->length, e->flags);
        func(ctx, (void*)e->cookie);
    }
    return ZX_OK;
}

zx_status_t eth_complete_rx(eth_client_t* eth, void* ctx,
                            void (*func)(void* ctx, void* cookie, size_t len, uint32_t flags)) {
    fuchsia_hardware_ethernet_FifoEntry entries[eth->rx_size];
    zx_status_t status;
    size_t count;
    if ((status = zx_fifo_read(eth->rx_fifo, sizeof(entries[0]), entries, countof(entries), &count)) < 0) {
        if (status == ZX_ERR_SHOULD_WAIT) {
            return ZX_OK;
        } else {
            return status;
        }
    }

    for (fuchsia_hardware_ethernet_FifoEntry* e = entries; count-- > 0; e++) {
        IORING_TRACE("eth:rx- c=%p o=%u l=%u f=%u\n",
                     e->cookie, e->offset, e->length, e->flags);
        func(ctx, (void*)e->cookie, e->length, e->flags);
    }
    return ZX_OK;
}


// Wait for completed rx packets
// ZX_ERR_PEER_CLOSED - far side disconnected
// ZX_ERR_TIMED_OUT - deadline lapsed
// ZX_OK - completed packets are available
zx_status_t eth_wait_rx(eth_client_t* eth, zx_time_t deadline) {
    zx_status_t status;
    zx_signals_t signals;

    if ((status = zx_object_wait_one(eth->rx_fifo,
                                     ZX_FIFO_READABLE | ZX_FIFO_PEER_CLOSED,
                                     deadline, &signals)) < 0) {
        if (signals & ZX_FIFO_READABLE) {
            return ZX_OK;
        }
        return status;
    }
    if (signals & ZX_FIFO_PEER_CLOSED) {
        return ZX_ERR_PEER_CLOSED;
    }
    return ZX_OK;
}