share C function to retrieve MTU across all UNIXes

5 files changed, 46 insertions, 20 deletions

diff --git a/psutil/_psbsd.py b/psutil/_psbsd.py
index 8474881b..46698a22 100644
--- a/psutil/_psbsd.py
+++ b/psutil/_psbsd.py
@@ -313,7 +313,8 @@ def net_if_stats():
     names = net_io_counters().keys()
     ret = {}
     for name in names:
-        isup, duplex, speed, mtu = cext_posix.net_if_stats(name)
+        mtu = cext_posix.net_if_mtu(name)
+        isup, duplex, speed = cext_posix.net_if_stats(name)
         if hasattr(_common, 'NicDuplex'):
             duplex = _common.NicDuplex(duplex)
         ret[name] = _common.snicstats(isup, duplex, speed, mtu)
diff --git a/psutil/_pslinux.py b/psutil/_pslinux.py
index 5d0f2787..0dfabacf 100644
--- a/psutil/_pslinux.py
+++ b/psutil/_pslinux.py
@@ -893,7 +893,8 @@ def net_if_stats():
     names = net_io_counters().keys()
     ret = {}
     for name in names:
-        isup, duplex, speed, mtu = cext.net_if_stats(name)
+        mtu = cext_posix.net_if_mtu(name)
+        isup, duplex, speed = cext.net_if_stats(name)
         duplex = duplex_map[duplex]
         ret[name] = _common.snicstats(isup, duplex, speed, mtu)
     return ret
diff --git a/psutil/_psosx.py b/psutil/_psosx.py
index 9e312400..74d6cc3d 100644
--- a/psutil/_psosx.py
+++ b/psutil/_psosx.py
@@ -194,7 +194,8 @@ def net_if_stats():
     names = net_io_counters().keys()
     ret = {}
     for name in names:
-        isup, duplex, speed, mtu = cext_posix.net_if_stats(name)
+        mtu = cext_posix.net_if_mtu(name)
+        isup, duplex, speed, = cext_posix.net_if_stats(name)
         if hasattr(_common, 'NicDuplex'):
             duplex = _common.NicDuplex(duplex)
         ret[name] = _common.snicstats(isup, duplex, speed, mtu)
diff --git a/psutil/_psutil_linux.c b/psutil/_psutil_linux.c
index c9be53d4..7d828faa 100644
--- a/psutil/_psutil_linux.c
+++ b/psutil/_psutil_linux.c
@@ -486,7 +486,6 @@ psutil_net_if_stats(PyObject* self, PyObject* args) {
     int ret;
     int duplex;
     int speed;
-    int mtu;
     struct ifreq ifr;
     struct ethtool_cmd ethcmd;
     PyObject *py_is_up = NULL;
@@ -510,12 +509,6 @@ psutil_net_if_stats(PyObject* self, PyObject* args) {
         py_is_up = Py_False;
     Py_INCREF(py_is_up);
 
-    // MTU
-    ret = ioctl(sock, SIOCGIFMTU, &ifr);
-    if (ret == -1)
-        goto error;
-    mtu = ifr.ifr_mtu;
-
     // duplex and speed
     memset(&ethcmd, 0, sizeof ethcmd);
     ethcmd.cmd = ETHTOOL_GSET;
@@ -540,7 +533,7 @@ psutil_net_if_stats(PyObject* self, PyObject* args) {
         }
     }
 
-    py_retlist = Py_BuildValue("[Oiii]", py_is_up, duplex, speed, mtu);
+    py_retlist = Py_BuildValue("[Oii]", py_is_up, duplex, speed);
     if (!py_retlist)
         goto error;
     close(sock);
@@ -583,7 +576,7 @@ PsutilMethods[] = {
     {"users", psutil_users, METH_VARARGS,
      "Return currently connected users as a list of tuples"},
     {"net_if_stats", psutil_net_if_stats, METH_VARARGS,
-     "Return NIC stats (isup, duplex, speed, mtu)"},
+     "Return NIC stats (isup, duplex, speed)"},
 
     // --- linux specific
 
diff --git a/psutil/_psutil_posix.c b/psutil/_psutil_posix.c
index 8098fbb9..54506322 100644
--- a/psutil/_psutil_posix.c
+++ b/psutil/_psutil_posix.c
@@ -245,6 +245,41 @@ error:
 
 
 /*
+ * Return NIC MTU. References:
+ * http://www.i-scream.org/libstatgrab/
+ */
+static PyObject *
+psutil_net_if_mtu(PyObject *self, PyObject *args) {
+    char *nic_name;
+    int sock = 0;
+    int ret;
+    int mtu;
+    struct ifreq ifr;
+
+    if (! PyArg_ParseTuple(args, "s", &nic_name))
+        return NULL;
+
+    sock = socket(AF_INET, SOCK_DGRAM, 0);
+    if (sock == -1)
+        goto error;
+
+    strncpy(ifr.ifr_name, nic_name, sizeof(ifr.ifr_name));
+    ret = ioctl(sock, SIOCGIFMTU, &ifr);
+    if (ret == -1)
+        goto error;
+    mtu = ifr.ifr_mtu;
+
+    return Py_BuildValue("i", mtu);
+
+error:
+    if (sock != 0)
+        close(sock);
+    PyErr_SetFromErrno(PyExc_OSError);
+    return NULL;
+}
+
+
+/*
  * net_if_stats() implementation. This is here because it is common
  * to both OSX and FreeBSD and I didn't know where else to put it.
  */
@@ -402,7 +437,6 @@ psutil_net_if_stats(PyObject *self, PyObject *args) {
     int ret;
     int duplex;
     int speed;
-    int mtu;
     struct ifreq ifr;
     struct ifmediareq ifmed;
 
@@ -426,12 +460,6 @@ psutil_net_if_stats(PyObject *self, PyObject *args) {
         py_is_up = Py_False;
     Py_INCREF(py_is_up);
 
-    // MTU
-    ret = ioctl(sock, SIOCGIFMTU, &ifr);
-    if (ret == -1)
-        goto error;
-    mtu = ifr.ifr_mtu;
-
     // speed / duplex
     memset(&ifmed, 0, sizeof(struct ifmediareq));
     strlcpy(ifmed.ifm_name, nic_name, sizeof(ifmed.ifm_name));
@@ -453,7 +481,7 @@ psutil_net_if_stats(PyObject *self, PyObject *args) {
     close(sock);
     Py_DECREF(py_is_up);
 
-    return Py_BuildValue("[Oiii]", py_is_up, duplex, speed, mtu);
+    return Py_BuildValue("[Oii]", py_is_up, duplex, speed);
 
 error:
     Py_XDECREF(py_is_up);
@@ -476,6 +504,8 @@ PsutilMethods[] = {
      "Set process priority"},
     {"net_if_addrs", psutil_net_if_addrs, METH_VARARGS,
      "Retrieve NICs information"},
+    {"net_if_mtu", psutil_net_if_mtu, METH_VARARGS,
+     "Retrieve NIC MTU"},
 #if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__)
     {"net_if_stats", psutil_net_if_stats, METH_VARARGS,
      "Return NIC stats."},