/*
 * eset_wap (ESET Web Access Protection module)
 * Copyright (C) 1992-2023 ESET, spol. s r.o.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * In case of any questions, you can contact us at ESET, spol. s r.o., Einsteinova 24, 851 01 Bratislava, Slovakia.
 */

#include "ewap_tracepoints.h"

#include "ewap_helpers.h"

#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 15, 0))

int ewap_tracepoint_register(struct ewap_tracepoint *hook) {
  int ret = tracepoint_probe_register(hook->name, hook->handler, NULL);

  if (ret != 0) {
    ewap_pr_log(EWAP_LOG_ERRORS, "failed to register tracepoint %s (%d)",
                hook->name, ret);
  } else {
    ewap_pr_log(EWAP_LOG_HOOKS, "hook for %s registered", hook->name);
  }

  return ret;
}

void ewap_tracepoint_unregister(struct ewap_tracepoint *hook) {
  tracepoint_probe_unregister(hook->name, hook->handler, NULL);
}

#else

static void tracepoint_iterator(struct tracepoint *tp, void *data) {
  struct ewap_tracepoint *hook = data;
  if (strcmp(tp->name, hook->name) == 0) {
    hook->tp = tp;
  }
}

int ewap_tracepoint_register(struct ewap_tracepoint *hook) {
  int ret;

  hook->tp = NULL;
  for_each_kernel_tracepoint(tracepoint_iterator, hook);

  if (!hook->tp) {
    ewap_pr_log(EWAP_LOG_ERRORS, "failed to find tracepoint for %s",
                hook->name);
    return -1;
  }

  ret = tracepoint_probe_register(hook->tp, hook->handler, NULL);

  if (ret != 0) {
    ewap_pr_log(EWAP_LOG_ERRORS, "failed to register tracepoint %s (%d)",
                hook->name, ret);
  } else {
    ewap_pr_log(EWAP_LOG_HOOKS, "hook for %s registered", hook->name);
  }

  return ret;
}

void ewap_tracepoint_unregister(struct ewap_tracepoint *hook) {
  if (hook->tp) {
    tracepoint_probe_unregister(hook->tp, hook->handler, NULL);
    ewap_pr_log(EWAP_LOG_HOOKS, "tracepoint %s unregistered", hook->name);
  }
}

#endif