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/*
* The MIT License (MIT)
*
* Copyright (c) 2020 Peter Lawrence
*
* influenced by lrndis https://github.com/fetisov/lrndis
*
* 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 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.
*
*/
/*
depending on the value of CFG_TUD_NET (tusb_config.h), this can be a CDC-ECM, RNDIS, or CDC-EEM USB virtual network adapter
CDC-ECM should be valid on Linux and MacOS hosts
RNDIS should be valid on Linux and Windows hosts
CDC-EEM should be valid on Linux hosts
You *must* customize tusb_config.h to set the CFG_TUD_NET definition to the type of these network adapters to emulate.
The MCU appears to the host as IP address 192.168.7.1, and provides a DHCP server, DNS server, and web server.
*/
#include "bsp/board.h"
#include "tusb.h"
#include "dhserver.h"
#include "dnserver.h"
#include "lwip/init.h"
#include "httpd.h"
/* lwip context */
static struct netif netif_data;
/* shared between tud_network_recv_cb() and service_traffic() */
static struct pbuf *received_frame;
/* this is used by this code, ./class/net/net_driver.c, and usb_descriptors.c */
/* ideally speaking, this should be generated from the hardware's unique ID (if available) */
/* it is suggested that the first two bytes are 0x02,0x02 to indicate a link-local address */
const uint8_t tud_network_mac_address[6] = {0x02,0x02,0x84,0x6A,0x96,0x00};
/* network parameters of this MCU */
static const ip_addr_t ipaddr = IPADDR4_INIT_BYTES(192, 168, 7, 1);
static const ip_addr_t netmask = IPADDR4_INIT_BYTES(255, 255, 255, 0);
static const ip_addr_t gateway = IPADDR4_INIT_BYTES(0, 0, 0, 0);
/* database IP addresses that can be offered to the host; this must be in RAM to store assigned MAC addresses */
static dhcp_entry_t entries[] =
{
/* mac ip address subnet mask lease time */
{ {0}, {192, 168, 7, 2}, {255, 255, 255, 0}, 24 * 60 * 60 },
{ {0}, {192, 168, 7, 3}, {255, 255, 255, 0}, 24 * 60 * 60 },
{ {0}, {192, 168, 7, 4}, {255, 255, 255, 0}, 24 * 60 * 60 }
};
/* DHCP configuration parameters, leveraging "entries" above */
static const dhcp_config_t dhcp_config =
{
{192, 168, 7, 1}, 67, /* server address (self), port */
{192, 168, 7, 1}, /* dns server (self) */
"usb", /* dns suffix */
TU_ARRAY_SIZE(entries), /* number of entries */
entries /* pointer to entries */
};
static err_t linkoutput_fn(struct netif *netif, struct pbuf *p)
{
(void)netif;
for (;;)
{
/* if TinyUSB isn't ready, we must signal back to lwip that there is nothing we can do */
if (!tud_ready())
return ERR_USE;
/* if the network driver can accept another packet, we make it happen */
if (tud_network_can_xmit())
{
tud_network_xmit(p);
return ERR_OK;
}
/* transfer execution to TinyUSB in the hopes that it will finish transmitting the prior packet */
tud_task();
}
}
static err_t output_fn(struct netif *netif, struct pbuf *p, const ip_addr_t *addr)
{
return etharp_output(netif, p, addr);
}
static err_t netif_init_cb(struct netif *netif)
{
LWIP_ASSERT("netif != NULL", (netif != NULL));
netif->mtu = CFG_TUD_NET_MTU;
netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP | NETIF_FLAG_UP;
netif->state = NULL;
netif->name[0] = 'E';
netif->name[1] = 'X';
netif->linkoutput = linkoutput_fn;
netif->output = output_fn;
return ERR_OK;
}
static void init_lwip(void)
{
struct netif *netif = &netif_data;
lwip_init();
/* the lwip virtual MAC address must be different from the host's; to ensure this, we toggle the LSbit */
netif->hwaddr_len = sizeof(tud_network_mac_address);
memcpy(netif->hwaddr, tud_network_mac_address, sizeof(tud_network_mac_address));
netif->hwaddr[5] ^= 0x01;
netif = netif_add(netif, &ipaddr, &netmask, &gateway, NULL, netif_init_cb, ip_input);
netif_set_default(netif);
}
/* handle any DNS requests from dns-server */
bool dns_query_proc(const char *name, ip_addr_t *addr)
{
if (0 == strcmp(name, "tiny.usb"))
{
*addr = ipaddr;
return true;
}
return false;
}
bool tud_network_recv_cb(struct pbuf *p)
{
/* this shouldn't happen, but if we get another packet before
parsing the previous, we must signal our inability to accept it */
if (received_frame) return false;
/* store away the pointer for service_traffic() to later handle */
received_frame = p;
return true;
}
static void service_traffic(void)
{
/* handle any packet received by tud_network_recv_cb() */
if (received_frame)
{
ethernet_input(received_frame, &netif_data);
pbuf_free(received_frame);
received_frame = NULL;
tud_network_recv_renew();
}
}
void tud_network_init_cb(void)
{
/* if the network is re-initializing and we have a leftover packet, we must do a cleanup */
if (received_frame)
{
pbuf_free(received_frame);
received_frame = NULL;
}
}
int main(void)
{
/* initialize TinyUSB */
board_init();
tusb_init();
/* initialize lwip, dhcp-server, dns-server, and http */
init_lwip();
while (!netif_is_up(&netif_data));
while (dhserv_init(&dhcp_config) != ERR_OK);
while (dnserv_init(&ipaddr, 53, dns_query_proc) != ERR_OK);
httpd_init();
while (1)
{
tud_task();
service_traffic();
}
return 0;
}
/* lwip has provision for using a mutex, when applicable */
sys_prot_t sys_arch_protect(void)
{
return 0;
}
void sys_arch_unprotect(sys_prot_t pval)
{
(void)pval;
}
/* lwip needs a millisecond time source, and the TinyUSB board support code has one available */
uint32_t sys_now(void)
{
return board_millis();
}
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