--- /dev/null
+/*
+ * vsys.c: CPython functions to wrap PlanetLab vsys API'
+ * Alina Quereilhac - 02/09/2012
+ *
+ * Copyright (c) 2012 INRIA
+ *
+ */
+
+#include <Python.h>
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/if_tun.h>
+#include <linux/ioctl.h>
+#include <net/if.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#define VSYS_TUNTAP "/vsys/fd_tuntap.control"
+#define VSYS_VIFUP_IN "/vsys/vif_up.in"
+#define VSYS_VIFUP_OUT "/vsys/vif_up.out"
+#define VSYS_VIFDOWN_IN "/vsys/vif_down.in"
+#define VSYS_VIFDOWN_OUT "/vsys/vif_down.out"
+#define VSYS_VROUTE_IN "/vsys/vroute.in"
+#define VSYS_VROUTE_OUT "/vsys/vroute.out"
+
+const size_t SIZE = 4096;
+
+int _fd_tuntap(int if_type, int no_pi, char *if_name);
+int _vif_up(const char *if_name, const char *ip, const char *prefix, int snat,
+ char *msg);
+int _vif_down(const char *if_name, char *msg);
+int _vroute (const char *action, const char *network, const char *prefix,
+ const char *host, const char *device, char *msg);
+
+/* Python wrapper for _fd_tuntap */
+static PyObject *
+fd_tuntap(PyObject *self, PyObject *args) {
+ int if_type, fd, no_pi = 0;
+ char *if_name;
+ PyObject *retval;
+
+ if(!PyArg_ParseTuple(args, "i|i", &if_type, &no_pi))
+ return NULL;
+
+ if((if_name = malloc(SIZE)) == NULL)
+ return PyErr_SetFromErrno(PyExc_OSError);
+
+ // just in case, initialize the buffer to 0
+ memset(if_name, 0, SIZE);
+
+ Py_BEGIN_ALLOW_THREADS;
+ fd = _fd_tuntap(if_type, no_pi, if_name);
+ Py_END_ALLOW_THREADS;
+
+ retval = Py_BuildValue("is", fd, if_name);
+ free(if_name);
+ return retval;
+}
+
+/* Python wrapper for _vif_up */
+static PyObject *
+vif_up(PyObject *self, PyObject *args) {
+ int ret, snat = 0; //false
+ char *if_name, *ip, *prefix, *msg;
+ PyObject *retval;
+
+ if(!PyArg_ParseTuple(args, "sss|i", &if_name, &ip, &prefix, &snat))
+ return NULL;
+
+ if((msg = malloc(SIZE)) == NULL)
+ return PyErr_SetFromErrno(PyExc_OSError);
+
+ // just in case, initialize the buffer to 0
+ memset(msg, 0, SIZE);
+
+ Py_BEGIN_ALLOW_THREADS;
+ ret = _vif_up(if_name, ip, prefix, snat, msg);
+ Py_END_ALLOW_THREADS;
+
+ retval = Py_BuildValue("is", ret, msg);
+ free(msg);
+ return retval;
+}
+
+/* Python wrapper for _vif_down */
+static PyObject *
+vif_down(PyObject *self, PyObject *args) {
+ int ret;
+ char *if_name, *msg;
+ PyObject *retval;
+
+ if(!PyArg_ParseTuple(args, "s", &if_name))
+ return NULL;
+
+ if((msg = malloc(SIZE)) == NULL)
+ return PyErr_SetFromErrno(PyExc_OSError);
+
+ // just in case, initialize the buffer to 0
+ memset(msg, 0, SIZE);
+
+ Py_BEGIN_ALLOW_THREADS;
+ ret = _vif_down(if_name, msg);
+ Py_END_ALLOW_THREADS;
+
+ retval = Py_BuildValue("is", ret, msg);
+ free(msg);
+ return retval;
+}
+
+/* Python wrapper for _vroute */
+static PyObject *
+vroute(PyObject *self, PyObject *args) {
+ int ret;
+ char *action, *network, *prefix, *host, *device, *msg;
+ PyObject *retval;
+
+ if(!PyArg_ParseTuple(args, "sssss", &action, &network, &prefix, &host, &device))
+ return NULL;
+
+ if((msg = malloc(SIZE)) == NULL)
+ return PyErr_SetFromErrno(PyExc_OSError);
+
+ // just in case, initialize the buffer to 0
+ memset(msg, 0, SIZE);
+
+ Py_BEGIN_ALLOW_THREADS;
+ ret = _vroute(action, network, prefix, host, device, msg);
+ Py_END_ALLOW_THREADS;
+
+ retval = Py_BuildValue("is", ret, msg);
+ free(msg);
+ return retval;
+}
+
+static PyMethodDef methods[] = {
+ {"fd_tuntap", fd_tuntap, METH_VARARGS, "(fd, if_name) = fd_tuntap(if_type, no_pi = False)"},
+ {"vif_up", vif_up, METH_VARARGS, "(code, msg) = vif_up(if_name, ip, prefix, snat = False)"},
+ {"vif_down", vif_down, METH_VARARGS, " (code, msg) = vif_up(if_name)"},
+ {"vroute", vroute, METH_VARARGS, "(code, msg) = vroute(action, network, prefix, host, device)"},
+ {NULL, NULL, 0, NULL}
+};
+
+PyMODINIT_FUNC init_vsys(void) {
+ PyObject *m;
+ m = Py_InitModule("_vsys", methods);
+ if (m == NULL)
+ return;
+}
+
+/*
+ * _fifo_push(): Pushes parameters into a fifo.
+ *
+ * Parameters:
+ * fifo_in: the name of the fifo to write parameters to
+ * fifo_out: the name of the fifo to read error from
+ * input: parameters formated as a string to push into the input fifo
+ * msg: buffer to return error to user
+ *
+ * Return value:
+ * On success, _fifo_push returns 0.
+ * On error, a negative integer is returned.
+ *
+ */
+static int _fifo_push (const char *fifo_in, const char *fifo_out,
+ const char *input, char *msg) {
+ FILE *in;
+ FILE *out;
+ int nbytes;
+
+ in = fopen (fifo_in, "a");
+
+ if (in == NULL){
+ snprintf (msg, SIZE, "Failed to open FIFO %s", fifo_in);
+ return -1;
+ }
+
+ out = fopen (fifo_out, "r");
+
+ if (out == NULL){
+ snprintf (msg, SIZE, "Failed to open FIFO %s", fifo_out);
+ return -2;
+ }
+
+ // send inputs to the fifo_in
+ fprintf (in, input);
+
+ // force flush and close the fifo_in so the program on the other side
+ // can process input.
+ fclose (in);
+
+ nbytes = fread(msg, SIZE, 1, out);
+
+ // the error buffer will not be empty if we read an error
+ if (strcmp(msg, "") != 0){
+ // an errror was read from the fifo_out ...
+ return -3;
+ }
+
+ fclose (out);
+
+ return 0;
+}
+
+/*
+ * _receive_fd(): Receives the file descriptor associated to the virtual
+ * device
+ *
+ * Parameters:
+ * vsys_sock: the vsys control socket which send the fd
+ * if_name: the buffer where the device name assigned by PlanetLab
+ * will be stored after creating the virtual interface
+ *
+ * Return value:
+ * On success, _receive_fd returns the file descriptor associated to the device.
+ * On error, a negative integer is returned.
+ *
+ */
+static int _receive_fd(int vsys_sock, char *if_name) {
+ struct msghdr msg;
+ struct iovec iov;
+ size_t ccmsg[CMSG_SPACE (sizeof(int)) / sizeof(size_t)];
+ struct cmsghdr *cmsg;
+ int rv;
+
+ // Use IOV to read interface name
+ iov.iov_base = if_name;
+ iov.iov_len = IFNAMSIZ;
+
+ msg.msg_name = 0;
+ msg.msg_namelen = 0;
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+
+ // old BSD implementations should use msg_accrights instead of msg_control.
+ // the interface is different.
+ msg.msg_control = ccmsg;
+ msg.msg_controllen = sizeof(ccmsg);
+
+ while (((rv = recvmsg (vsys_sock, &msg, 0)) == -1) && errno == EINTR)
+ {}
+
+ cmsg = CMSG_FIRSTHDR (&msg);
+ if (cmsg->cmsg_type != SCM_RIGHTS){
+ snprintf (if_name, SIZE, "Got control message of unknown type");
+ return -1;
+ }
+
+ int* retfd = (int*)CMSG_DATA (cmsg);
+ return *retfd;
+}
+
+/*
+ * _fd_tuntap(): Creates a TAP or TUN device in PlanetLab, and returns the
+ * device name and the associated file descriptor.
+ *
+ * Parameters:
+ * if_type: the type of virtual device. Either IFF_TAP (0x0001) or
+ * IFF_TUN (0x0002)
+ * no_pi: set flag IFF_NO_PI
+ * if_name: the buffer where the device name assigned by PlanetLab
+ * will be stored after creating the virtual interface.
+ * When an error ocurrs, if_name is used as message buffer
+ *
+ * Return value:
+ * On success, _fd_tuntap returns the file descriptor associated to the device.
+ * On error, a negative integer is returned.
+ *
+ */
+int _fd_tuntap(int if_type, int no_pi, char *if_name) {
+ int vsys_sock, fd;
+ struct sockaddr_un addr;
+
+ vsys_sock = socket (AF_UNIX, SOCK_STREAM, 0);
+
+ if (vsys_sock == -1){
+ snprintf (if_name, SIZE, strerror(errno));
+ return -2;
+ }
+
+ memset (&addr, 0, sizeof(struct sockaddr_un));
+
+ addr.sun_family = AF_UNIX;
+ strncpy (addr.sun_path, VSYS_TUNTAP, sizeof(addr.sun_path) - 1);
+
+ int ret = connect (vsys_sock, (struct sockaddr *) &addr,
+ sizeof(struct sockaddr_un));
+
+ if (ret == -1){
+ snprintf (if_name, SIZE, strerror(errno));
+ return -3;
+ }
+
+ // send vif type (either TAP or TUN)
+ ret = send (vsys_sock, &if_type, sizeof(if_type), 0);
+
+ if (ret != sizeof(if_type)){
+ snprintf (if_name, SIZE, "Could not send parameter to vsys control socket");
+ return -4;
+ }
+
+ // receive the file descriptor associated to the virtual interface
+ fd = _receive_fd (vsys_sock, if_name);
+
+ if (fd < 0){
+ snprintf (if_name, SIZE, "Invalid file descriptor");
+ return -5;
+ }
+
+/**
+* XXX: For now unsupported functionality
+*
+ struct ifreq ifr;
+ ret = ioctl (fd, TUNGETIFF, (void *)&ifr);
+ if (ret == -1){
+ close (fd);
+ snprintf (if_name, SIZE, strerror(errno));
+ return -6;
+ }
+
+ // flag IFF_NO_PI: don't add the extra PI header
+ if (no_pi){
+ ifr.ifr_flags |= IFF_NO_PI;
+ }
+
+ // flag IFF_ONE_QUEUE: disable normal network device queue and use only the
+ // tun/tap driver internal queue. QoS tools will not be
+ // able to control queueing for the device in this case.
+ ifr.ifr_flags |= IFF_ONE_QUEUE;
+
+ ret = ioctl (fd, TUNSETIFF, (void *)&ifr);
+ if (ret == -1){
+ close (fd);
+ snprintf (if_name, SIZE, strerror(errno));
+ return -7;
+ }
+*/
+
+ return fd;
+
+}
+
+/*
+ * _vif_up(): Configures a virtual interface with the values given by the user
+ * and sets its state UP
+ *
+ * Parameters:
+ * if_name: the name of the virtual interface
+ * ip: the IP address to be assigned to the interface
+ * prefix: the network prefix associated to the IP address
+ * snat: whether to enable SNAT on the virtual interface.
+ * msg: buffer to return error to user
+ *
+ * Return value:
+ * On success, return 0.
+ * On error, a negative integer is returned.
+ *
+ */
+int _vif_up (const char *if_name, const char *ip, const char *prefix,
+ int snat, char *msg) {
+
+ char input[SIZE]; // big buffer
+
+ snprintf (input, SIZE, "%s\n%s\n%s\nsnat=%d\n", if_name, ip, prefix, snat);
+
+ return _fifo_push (VSYS_VIFUP_IN, VSYS_VIFUP_OUT, input, msg);
+
+}
+
+/*
+ * _vif_down(): Sets the state of a virtual interface DOWN
+ *
+ * Parameters:
+ * if_name: the name of the virtual interface
+ * msg: buffer to return error to user
+ *
+ * Return value:
+ * On success, return 0.
+ * On error, a negative integer is returned.
+ *
+ */
+int _vif_down (const char *if_name, char *msg) {
+
+ char input[SIZE];
+
+ snprintf(input, SIZE, "%s\n", if_name);
+
+ return _fifo_push (VSYS_VIFDOWN_IN, VSYS_VIFDOWN_OUT, input, msg);
+
+}
+
+/*
+ * vroute() : Adds or removes routes on PlanetLab virtual interfaces (TAP/TUN).
+ *
+ * Note that all networks and gateways must belong to the virtual
+ * network segment associated to the vsys_vnet tag for the slice.
+ *
+ * Parameters:
+ * action: either 'add' or 'del'
+ * network: destintation network
+ * prefix: destination network prefix
+ * host: IP of gateway virtual interface
+ * device: name of the gateway virtual interface
+ * msg: buffer to return error to user
+ *
+ * Return value:
+ * On success, vroute returns 0.
+ * On error, a negative integer is returned.
+ *
+ */
+int _vroute (const char *action, const char *network, const char *prefix,
+ const char *host, const char *device, char *msg) {
+
+ char input[SIZE];
+
+ snprintf(input, SIZE, "%s %s/%s gw %s %s\n", action, network, prefix, host, device);
+
+ return _fifo_push (VSYS_VROUTE_IN, VSYS_VROUTE_OUT, input, msg);
+
+}
+
git://git.onelab.eu / vsys-scripts.git / blobdiff