git.scottworley.com Git - tattlekey/blob - client/net.c

   1 /* tattlekey: A one-key UDP keyboard
   2  * Copyright (C) 2023  Scott Worley <scottworley@scottworley.com>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "net.h"
  19 #include "blink.h"
  20 #include "config.h"
  21
  22 #include "pico/cyw43_arch.h"
  23
  24 #include "lwip/pbuf.h"
  25 #include "lwip/udp.h"
  26
  27 /* We only ever send to one address, and we only ever have one thread, so just
  28  * use one udp_pcb */
  29 static struct udp_pcb *the_pcb = NULL;
  30
  31 static void initialize_the_pcb() {
  32   if (the_pcb)
  33     return;
  34
  35   the_pcb = udp_new();
  36   if (!the_pcb)
  37     signal_error_by_blinking();
  38
  39   ip_addr_t ipaddr;
  40   if (ip4addr_aton(config_tattle_server_ip_address, &ipaddr) == 0)
  41     signal_error_by_blinking();
  42
  43   if (udp_connect(the_pcb, &ipaddr, config_tattle_port) != ERR_OK)
  44     signal_error_by_blinking();
  45 }
  46
  47 struct tattle_message_wire_format {
  48   u16_t sender;
  49   u16_t seq;
  50   u16_t ago;
  51 };
  52
  53 void send_report_packet(u16_t seq, u16_t ago) {
  54   cyw43_arch_lwip_begin();
  55
  56   initialize_the_pcb();
  57
  58   struct pbuf *p = pbuf_alloc(
  59       PBUF_TRANSPORT, sizeof(struct tattle_message_wire_format), PBUF_RAM);
  60   if (!p)
  61     signal_error_by_blinking();
  62
  63   struct tattle_message_wire_format *msg =
  64       (struct tattle_message_wire_format *)(p->payload);
  65   msg->sender = htons(config_this_tattler_identity);
  66   msg->seq = htons(seq);
  67   msg->ago = htons(ago);
  68
  69   if (udp_send(the_pcb, p) != ERR_OK)
  70     signal_error_by_blinking();
  71
  72   pbuf_free(p);
  73
  74   cyw43_arch_lwip_end();
  75 }