hijack.c

#include "main-header.h"
#include "sys/types.h"
 
#include "hijack.h"
 
void (*usb_receive_hook)(uint8_t *received, int size);
void (*esp32_receive_hook)(uint8_t received);
void hijack_init() {
  usb_receive_hook = NULL;
  esp32_receive_hook = NULL;
}
// is usb hijacked?
int is_hijacked_usb_acm() {
  return usb_receive_hook != NULL;
}
// is usb hijacked?
int is_hijacked_esp32() {
  return esp32_receive_hook != NULL;
}
void unhijack_esp32() {
  if (esp32_receive_hook != NULL) {
    printf("ESP32 Usart control regained userapp\r\n");
  }
  esp32_receive_hook = NULL;
}
void unhijack_usb_acm() {
  if (usb_receive_hook != NULL) {
    printf("USB ACM control regained from userapp\r\n");
  }
  usb_receive_hook = NULL;
}
// stop hijacker
void unhijack_all() {
  unhijack_usb_acm();
  unhijack_esp32();
}
int hijack_esp32_usart(void ( *receive_hook )(uint8_t received)) {
  if (receive_hook == NULL) {
    printf("ESP32 not hijacked, hook is null\r\n");
    return 1;
  }
  printf("ESP32 control transferred to userapp\r\n");
  esp32_receive_hook = receive_hook;
  return 0;
}
// hijacker announced its intention to hijack
int hijack_usb_acm(void ( *receive_hook )(uint8_t *received, int size)) {
  printf("USB ACM control transferred to userapp\r\n");
  usb_receive_hook = receive_hook;
  return 0;
}
// hijacker wants to send stuff via usb
int send_via_usb_acm(uint8_t *buf, int size) {
  mculib_usb_send(MAIN_MCULIBHANDLE, size, buf);
  return 0;
}
// new byte(s) received, possibly for hijacker. returns 1 if sent to hijacker, 0 if not
int hijack_receive_on_usb_acm(uint8_t *buf, int size) {
  void (*h)(uint8_t *received, int size) = usb_receive_hook;
  if (h == NULL) {
    return 0;
  }
  h(buf, size);
  return 1;
}
int hijack_receive_esp32(uint8_t received) {
  void (*h)(uint8_t received) = esp32_receive_hook;
  if (h == NULL) {
    return 0;
  }
  h(received);
  return 1;
}