- extension to gather information about local network interfaces

diff --git a/sioc.c b/sioc.c
new file mode 100644 (file)
index 0000000..0ddeb31
--- /dev/null
+++ b/sioc.c
@@ -0,0 +1,160 @@
+/*
+ * Extension to gather information about network interfaces
+ *
+ * Mark Huang <mlhuang@cs.princeton.edu>
+ * Copyright (C) 2006 The Trustees of Princeton University
+ *
+ * $Id$
+ */
+
+#include <Python.h>
+
+/* struct ifreq */
+#include <net/if.h>
+
+/* socket() */
+#include <sys/types.h>
+#include <sys/socket.h>
+
+/* ioctl() */
+#include <sys/ioctl.h>
+
+/* inet_ntoa() */
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+/* ARPHRD_ETHER */
+#include <net/if_arp.h>
+
+/* ETH_ALEN */
+#include <net/ethernet.h>
+
+static PyObject *
+gifconf(PyObject *self, PyObject *args)
+{
+       struct ifconf ifc;
+       int len;
+       int s;
+       PyObject *addrs;
+       void *buf;
+       struct ifreq *ifr;
+       struct sockaddr_in *sin;
+
+       if ((s = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
+               return PyErr_SetFromErrno(PyExc_OSError);
+
+       len = sizeof(struct ifreq);
+       ifc.ifc_len = 0;
+       ifc.ifc_req = NULL;
+
+       do {
+               len *= 2;
+               buf = realloc(ifc.ifc_req, len);
+               if (!buf)
+                       break;
+               ifc.ifc_len = len;
+               ifc.ifc_req = buf;
+               if (ioctl(s, SIOCGIFCONF, &ifc) < 0)
+                       break;
+       } while (ifc.ifc_len >= len);
+
+       close(s);
+
+       addrs = Py_BuildValue("{}");
+
+       for (ifr = ifc.ifc_req, len = ifc.ifc_len; len > 0; ifr++, len -= sizeof(struct ifreq)) {
+               sin = (struct sockaddr_in *) &ifr->ifr_addr;
+               PyDict_SetItem(addrs,
+                              Py_BuildValue("s", ifr->ifr_name),
+                              Py_BuildValue("s", inet_ntoa(sin->sin_addr)));
+       }
+
+       if (ifc.ifc_req)
+               free(ifc.ifc_req);
+
+       return addrs;
+}
+
+static PyObject *
+gifaddr(PyObject *self, PyObject *args)
+{
+       const char *name;
+       struct ifreq ifr;
+       int s;
+       struct sockaddr_in *sin;
+
+       if (!PyArg_ParseTuple(args, "s", &name))
+               return NULL;
+
+       memset(&ifr, 0, sizeof(ifr));
+       strncpy(ifr.ifr_name, name, IFNAMSIZ);
+
+       if ((s = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
+               return PyErr_SetFromErrno(PyExc_OSError);
+
+       if (ioctl(s, SIOCGIFADDR, &ifr) < 0) {
+               close(s);
+               return PyErr_SetFromErrno(PyExc_OSError);
+       }
+
+       close(s);
+
+       sin = (struct sockaddr_in *) &ifr.ifr_addr;
+       return Py_BuildValue("s", inet_ntoa(sin->sin_addr));
+}
+
+static PyObject *
+gifhwaddr(PyObject *self, PyObject *args)
+{
+       const char *name;
+       struct ifreq ifr;
+       int s;
+       char mac[sizeof(ifr.ifr_hwaddr.sa_data) * 3], *c;
+       int len, i;
+
+       if (!PyArg_ParseTuple(args, "s", &name))
+               return NULL;
+
+       memset(&ifr, 0, sizeof(ifr));
+       strncpy(ifr.ifr_name, name, IFNAMSIZ);
+
+       if ((s = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
+               return PyErr_SetFromErrno(PyExc_OSError);
+
+       if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0) {
+               close(s);
+               return PyErr_SetFromErrno(PyExc_OSError);
+       }
+
+       close(s);
+
+       switch (ifr.ifr_hwaddr.sa_family) {
+       case ARPHRD_ETHER:
+               len = ETH_ALEN;
+               break;
+       default:
+               len = sizeof(ifr.ifr_hwaddr.sa_data);
+               break;
+       }
+
+       for (i = 0, c = mac; i < len; i++) {
+               if (i)
+                       c += sprintf(c, ":");
+               c += sprintf(c, "%02X", (unsigned char)(ifr.ifr_hwaddr.sa_data[i] & 0xFF));
+       }
+
+       return Py_BuildValue("s", mac);
+}
+
+static PyMethodDef  methods[] = {
+       { "gifconf", gifconf, METH_VARARGS, "Get all interface addresses" },
+       { "gifaddr", gifaddr, METH_VARARGS, "Get interface address" },
+       { "gifhwaddr", gifhwaddr, METH_VARARGS, "Get interface hardware address" },
+       { NULL, NULL, 0, NULL }
+};
+
+PyMODINIT_FUNC
+initsioc(void)
+{
+       Py_InitModule("sioc", methods);
+}