+#include "net.h"
+#include "blink.h"
+#include "config.h"
+
+#include "pico/cyw43_arch.h"
+
+#include "lwip/pbuf.h"
+#include "lwip/udp.h"
+
+/* We only ever send to one address, and we only ever have one thread, so just
+ * use one udp_pcb */
+static struct udp_pcb *the_pcb = NULL;
+
+static void initialize_the_pcb() {
+ if (the_pcb)
+ return;
+
+ the_pcb = udp_new();
+ if (!the_pcb)
+ signal_error_by_blinking();
+
+ ip_addr_t ipaddr;
+ if (ip4addr_aton(tattle_server_ip_address, &ipaddr) == 0)
+ signal_error_by_blinking();
+
+ if (udp_connect(the_pcb, &ipaddr, htons(tattle_port)) != ERR_OK)
+ signal_error_by_blinking();
+}
+
+struct tattle_message_wire_format {
+ u16_t sender;
+ u16_t seq;
+ u16_t ago;
+};
+
+void send_report(u16_t seq, u16_t ago) {
+ cyw43_arch_lwip_begin();
+
+ initialize_the_pcb();
+
+ struct pbuf *p = pbuf_alloc(
+ PBUF_TRANSPORT, sizeof(struct tattle_message_wire_format), PBUF_RAM);
+ if (!p)
+ signal_error_by_blinking();
+
+ struct tattle_message_wire_format *msg =
+ (struct tattle_message_wire_format *)(p->payload);
+ msg->sender = htons(this_tattler_identity);
+ msg->seq = htons(seq);
+ msg->ago = htons(ago);
+
+ if (udp_send(the_pcb, p) != ERR_OK)
+ signal_error_by_blinking();
+
+ pbuf_free(p);
+
+ cyw43_arch_lwip_end();
+}