Fix bug: incorrect network interface returned by net_io_counters(True…

[sk6249]

…) and net_if_addrs()

[Bug description]
When network interface contains non-ansii characters, such as Chinese
characters, the network interface name returned by net_io_counters(True)
and net_if_addrs() were truncated or blank string.
[Solution]
This fix ensures these two functions will return correct network
interface names.

[mrjefftang]

Since pCurrAddresses->FriendlyName is defined as PWCHAR [1], couldn't the same be accomplished by calling PyUnicode_FromWideChar(pCurrAddresses->FriendlyName, wcslen(pCurrAddresses->FriendlyName)) or am I missing something?

typedef struct _IP_ADAPTER_ADDRESSES {
...
  PWCHAR                             FriendlyName;
...
} IP_ADAPTER_ADDRESSES, *PIP_ADAPTER_ADDRESSES;

PyObject* PyUnicode_FromWideChar(const wchar_t *w, Py_ssize_t size) [2]

[1] https://msdn.microsoft.com/en-us/library/windows/desktop/aa366058(v=vs.85).aspx
[2] https://docs.python.org/3/c-api/unicode.html

[sk6249]

Hi mrjefftang,

Yes, PyUnicode_FromWideChar is better, and can solve this issue.
Here is the new function define which uses PyUnicode_FromWideChar:

/*
 * Return a Python list of named tuples with overall network I/O information
 */
static PyObject *
psutil_net_io_counters(PyObject *self, PyObject *args) {
    DWORD dwRetVal = 0;
    MIB_IFROW *pIfRow = NULL;
    PIP_ADAPTER_ADDRESSES pAddresses = NULL;
    PIP_ADAPTER_ADDRESSES pCurrAddresses = NULL;

    PyObject *py_retdict = PyDict_New();
    PyObject *py_nic_info = NULL;
    PyObject *py_nic_name = NULL;

    if (py_retdict == NULL)
        return NULL;
    pAddresses = psutil_get_nic_addresses();
    if (pAddresses == NULL)
        goto error;
    pCurrAddresses = pAddresses;

    while (pCurrAddresses) {
        py_nic_name = NULL;
        py_nic_info = NULL;
        pIfRow = (MIB_IFROW *) malloc(sizeof(MIB_IFROW));

        if (pIfRow == NULL) {
            PyErr_NoMemory();
            goto error;
        }

        pIfRow->dwIndex = pCurrAddresses->IfIndex;
        dwRetVal = GetIfEntry(pIfRow);
        if (dwRetVal != NO_ERROR) {
            PyErr_SetString(PyExc_RuntimeError, "GetIfEntry() failed.");
            goto error;
        }

        py_nic_info = Py_BuildValue("(kkkkkkkk)",
                                    pIfRow->dwOutOctets,
                                    pIfRow->dwInOctets,
                                    pIfRow->dwOutUcastPkts,
                                    pIfRow->dwInUcastPkts,
                                    pIfRow->dwInErrors,
                                    pIfRow->dwOutErrors,
                                    pIfRow->dwInDiscards,
                                    pIfRow->dwOutDiscards);
        if (!py_nic_info)
            goto error;

        py_nic_name = PyUnicode_FromWideChar(pCurrAddresses->FriendlyName, 
                                             wcslen(pCurrAddresses->FriendlyName));

        if (py_nic_name == NULL)
            goto error;
        if (PyDict_SetItem(py_retdict, py_nic_name, py_nic_info))
            goto error;
        Py_XDECREF(py_nic_name);
        Py_XDECREF(py_nic_info);

        free(pIfRow);
        pCurrAddresses = pCurrAddresses->Next;
    }

    free(pAddresses);
    return py_retdict;

error:
    Py_XDECREF(py_nic_name);
    Py_XDECREF(py_nic_info);
    Py_DECREF(py_retdict);
    if (pAddresses != NULL)
        free(pAddresses);
    if (pIfRow != NULL)
        free(pIfRow);
    return NULL;
}

/*
 * Return NICs addresses.
 */

static PyObject *
psutil_net_if_addrs(PyObject *self, PyObject *args) {
    unsigned int i = 0;
    ULONG family;
    PCTSTR intRet;
    char *ptr;
    char buff[100];
    DWORD bufflen = 100;
    PIP_ADAPTER_ADDRESSES pAddresses = NULL;
    PIP_ADAPTER_ADDRESSES pCurrAddresses = NULL;
    PIP_ADAPTER_UNICAST_ADDRESS pUnicast = NULL;

    PyObject *py_retlist = PyList_New(0);
    PyObject *py_tuple = NULL;
    PyObject *py_address = NULL;
    PyObject *py_mac_address = NULL;
    PyObject *py_nic_name = NULL;

    if (py_retlist == NULL)
        return NULL;

    pAddresses = psutil_get_nic_addresses();
    if (pAddresses == NULL)
        goto error;
    pCurrAddresses = pAddresses;

    while (pCurrAddresses) {
        pUnicast = pCurrAddresses->FirstUnicastAddress;

        py_nic_name = NULL;
        py_nic_name = PyUnicode_FromWideChar(pCurrAddresses->FriendlyName, 
                                             wcslen(pCurrAddresses->FriendlyName));
        if (py_nic_name == NULL)
            goto error;

        // MAC address
        if (pCurrAddresses->PhysicalAddressLength != 0) {
            ptr = buff;
            *ptr = '\0';
            for (i = 0; i < (int) pCurrAddresses->PhysicalAddressLength; i++) {
                if (i == (pCurrAddresses->PhysicalAddressLength - 1)) {
                    sprintf_s(ptr, _countof(buff), "%.2X\n",
                            (int)pCurrAddresses->PhysicalAddress[i]);
                }
                else {
                    sprintf_s(ptr, _countof(buff), "%.2X-",
                            (int)pCurrAddresses->PhysicalAddress[i]);
                }
                ptr += 3;
            }
            *--ptr = '\0';

#if PY_MAJOR_VERSION >= 3
            py_mac_address = PyUnicode_FromString(buff);
#else
            py_mac_address = PyString_FromString(buff);
#endif
            if (py_mac_address == NULL)
                goto error;

            Py_INCREF(Py_None);
            Py_INCREF(Py_None);
            Py_INCREF(Py_None);
            py_tuple = Py_BuildValue(
                "(OiOOOO)",
                py_nic_name,
                -1,  // this will be converted later to AF_LINK
                py_mac_address,
                Py_None,  // netmask (not supported)
                Py_None,  // broadcast (not supported)
                Py_None  // ptp (not supported on Windows)
            );
            if (! py_tuple)
                goto error;
            if (PyList_Append(py_retlist, py_tuple))
                goto error;
            Py_DECREF(py_tuple);
            Py_DECREF(py_mac_address);
        }

        // find out the IP address associated with the NIC
        if (pUnicast != NULL) {
            for (i = 0; pUnicast != NULL; i++) {
                family = pUnicast->Address.lpSockaddr->sa_family;
                if (family == AF_INET) {
                    struct sockaddr_in *sa_in = (struct sockaddr_in *)
                        pUnicast->Address.lpSockaddr;
                    intRet = inet_ntop(AF_INET, &(sa_in->sin_addr), buff,
                                       bufflen);
                }
                else if (family == AF_INET6) {
                    struct sockaddr_in6 *sa_in6 = (struct sockaddr_in6 *)
                        pUnicast->Address.lpSockaddr;
                    intRet = inet_ntop(AF_INET6, &(sa_in6->sin6_addr),
                                       buff, bufflen);
                }
                else {
                    // we should never get here
                    pUnicast = pUnicast->Next;
                    continue;
                }

                if (intRet == NULL) {
                    PyErr_SetFromWindowsErr(GetLastError());
                    goto error;
                }
#if PY_MAJOR_VERSION >= 3
                py_address = PyUnicode_FromString(buff);
#else
                py_address = PyString_FromString(buff);
#endif
                if (py_address == NULL)
                    goto error;

                Py_INCREF(Py_None);
                Py_INCREF(Py_None);
                Py_INCREF(Py_None);
                py_tuple = Py_BuildValue(
                    "(OiOOOO)",
                    py_nic_name,
                    family,
                    py_address,
                    Py_None,  // netmask (not supported)
                    Py_None,  // broadcast (not supported)
                    Py_None  // ptp (not supported on Windows)
                );

                if (! py_tuple)
                    goto error;
                if (PyList_Append(py_retlist, py_tuple))
                    goto error;
                Py_DECREF(py_tuple);
                Py_DECREF(py_address);

                pUnicast = pUnicast->Next;
            }
        }
        Py_DECREF(py_nic_name);
        pCurrAddresses = pCurrAddresses->Next;
    }

    free(pAddresses);
    return py_retlist;

error:
    if (pAddresses)
        free(pAddresses);
    Py_DECREF(py_retlist);
    Py_XDECREF(py_tuple);
    Py_XDECREF(py_address);
    Py_XDECREF(py_nic_name);
    return NULL;
}

Do you have any new comments?

[mrjefftang]

This looks good to me.

[giampaolo]

For the record. This solves the following issues:

Python 2 was not returning unicode:

C:\>C:\python27\python -c "import psutil;  print(psutil.net_if_addrs().keys())"
[..., 'Local Area Connection\xe8']

Python 3 was segfaulting:

C:\>C:\python34\python -c "import psutil;  print(psutil.net_if_addrs().keys())"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
segfault