Fix #517 by testing ksp->ks_name is a network interface

instead of testing ksp->ks_module is 'link'

psutil/_psutil_sunos.c

@@ -675,6 +675,9 @@ psutil_net_io_counters(PyObject *self, PyObject *args) {
     kstat_ctl_t    *kc = NULL;
     kstat_t *ksp;
     kstat_named_t *rbytes, *wbytes, *rpkts, *wpkts, *ierrs, *oerrs;
+    int ret;
+    int sock = -1;
+    struct lifreq ifr;
 
     PyObject *py_retdict = PyDict_New();
     PyObject *py_ifc_info = NULL;
@@ -685,25 +688,30 @@ psutil_net_io_counters(PyObject *self, PyObject *args) {
     if (kc == NULL)
         goto error;
 
+    sock = socket(AF_INET, SOCK_DGRAM, 0);
+    if (sock == -1)
+        goto error;
+
     ksp = kc->kc_chain;
     while (ksp != NULL) {
         if (ksp->ks_type != KSTAT_TYPE_NAMED)
             goto next;
         if (strcmp(ksp->ks_class, "net") != 0)
             goto next;
-        /*
-        // XXX "lo" (localhost) interface makes kstat_data_lookup() fail
-        // (maybe because "ifconfig -a" says it's a virtual interface?).
-        if ((strcmp(ksp->ks_module, "link") != 0) &&
-            (strcmp(ksp->ks_module, "lo") != 0)) {
-            goto skip;
-        */
-        if ((strcmp(ksp->ks_module, "link") != 0))
+        // skip 'lo' (localhost) because it doesn't have the statistics we need
+        // and it makes kstat_data_lookup() fail
+        if (strcmp(ksp->ks_module, "lo") == 0)
+            goto next;
+
+        // check if this is a network interface by sending a ioctl
+        strncpy(ifr.lifr_name, ksp->ks_name, sizeof(ifr.lifr_name));
+        ret = ioctl(sock, SIOCGLIFFLAGS, &ifr);
+        if (ret == -1)
             goto next;
 
         if (kstat_read(kc, ksp, NULL) == -1) {
             errno = 0;
-            continue;
+            goto next;
         }
 
         rbytes = (kstat_named_t *)kstat_data_lookup(ksp, "rbytes");
@@ -752,13 +760,17 @@ psutil_net_io_counters(PyObject *self, PyObject *args) {
     }
 
     kstat_close(kc);
+    close(sock);
     return py_retdict;
 
 error:
     Py_XDECREF(py_ifc_info);
     Py_DECREF(py_retdict);
     if (kc != NULL)
         kstat_close(kc);
+    if (sock != -1) {
+        close(sock);
+    }
     return NULL;
 }
 
@@ -1138,7 +1150,7 @@ psutil_net_if_stats(PyObject* self, PyObject* args) {
     kstat_t *ksp;
     kstat_named_t *knp;
     int ret;
-    int sock = 0;
+    int sock = -1;
     int duplex;
     int speed;
 
@@ -1226,7 +1238,7 @@ psutil_net_if_stats(PyObject* self, PyObject* args) {
     Py_XDECREF(py_is_up);
     Py_XDECREF(py_ifc_info);
     Py_DECREF(py_retdict);
-    if (sock != 0)
+    if (sock != -1)
         close(sock);
     if (kc != NULL)
         kstat_close(kc);