/*
 * Copyright (c) 2009, Jay Loden, Giampaolo Rodola'. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

// Networks related functions. Original code was refactored and moved
// from psutil/_psutil_osx.c in 2023. This is the GIT blame before the move:
// https://github.com/giampaolo/psutil/blame/efd7ed3/psutil/_psutil_osx.c

#include <Python.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <net/if.h>

#include "../../_psutil_common.h"


PyObject *
psutil_net_io_counters(PyObject *self, PyObject *args) {
    char *buf = NULL, *lim, *next;
    struct if_msghdr *ifm;
    int mib[6];
    mib[0] = CTL_NET;          // networking subsystem
    mib[1] = PF_ROUTE;         // type of information
    mib[2] = 0;                // protocol (IPPROTO_xxx)
    mib[3] = 0;                // address family
    mib[4] = NET_RT_IFLIST2;   // operation
    mib[5] = 0;
    size_t len;
    PyObject *py_ifc_info = NULL;
    PyObject *py_retdict = PyDict_New();

    if (py_retdict == NULL)
        return NULL;

    if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
        PyErr_SetFromErrno(PyExc_OSError);
        goto error;
    }

    buf = malloc(len);
    if (buf == NULL) {
        PyErr_NoMemory();
        goto error;
    }

    if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
        PyErr_SetFromErrno(PyExc_OSError);
        goto error;
    }

    lim = buf + len;

    for (next = buf; next < lim; ) {
        ifm = (struct if_msghdr *)next;
        next += ifm->ifm_msglen;

        if (ifm->ifm_type == RTM_IFINFO2) {
            py_ifc_info = NULL;
            struct if_msghdr2 *if2m = (struct if_msghdr2 *)ifm;
            struct sockaddr_dl *sdl = (struct sockaddr_dl *)(if2m + 1);
            char ifc_name[32];

            strncpy(ifc_name, sdl->sdl_data, sdl->sdl_nlen);
            ifc_name[sdl->sdl_nlen] = 0;

            py_ifc_info = Py_BuildValue(
                "(KKKKKKKi)",
                if2m->ifm_data.ifi_obytes,
                if2m->ifm_data.ifi_ibytes,
                if2m->ifm_data.ifi_opackets,
                if2m->ifm_data.ifi_ipackets,
                if2m->ifm_data.ifi_ierrors,
                if2m->ifm_data.ifi_oerrors,
                if2m->ifm_data.ifi_iqdrops,
                0);  // dropout not supported

            if (!py_ifc_info)
                goto error;
            if (PyDict_SetItemString(py_retdict, ifc_name, py_ifc_info))
                goto error;
            Py_CLEAR(py_ifc_info);
        }
        else {
            continue;
        }
    }

    free(buf);
    return py_retdict;

error:
    Py_XDECREF(py_ifc_info);
    Py_DECREF(py_retdict);
    if (buf != NULL)
        free(buf);
    return NULL;
}