--- /dev/null
+/* Xenbus code for netif backend
+ Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
+ Copyright (C) 2005 XenSource Ltd
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include <stdarg.h>
+#include <linux/module.h>
+#include <xen/xenbus.h>
+#include "common.h"
+
+#if 0
+#undef DPRINTK
+#define DPRINTK(fmt, args...) \
+ printk("netback/xenbus (%s:%d) " fmt ".\n", __FUNCTION__, __LINE__, ##args)
+#endif
+
+struct backend_info
+{
+ struct xenbus_device *dev;
+ netif_t *netif;
+ struct xenbus_watch backend_watch;
+ enum xenbus_state frontend_state;
+};
+
+static int connect_rings(struct backend_info *);
+static void connect(struct backend_info *);
+static void maybe_connect(struct backend_info *);
+static void backend_changed(struct xenbus_watch *, const char **,
+ unsigned int);
+
+static int netback_remove(struct xenbus_device *dev)
+{
+ struct backend_info *be = dev->dev.driver_data;
+
+ if (be->backend_watch.node) {
+ unregister_xenbus_watch(&be->backend_watch);
+ kfree(be->backend_watch.node);
+ be->backend_watch.node = NULL;
+ }
+ if (be->netif) {
+ netif_disconnect(be->netif);
+ be->netif = NULL;
+ }
+ kfree(be);
+ dev->dev.driver_data = NULL;
+ return 0;
+}
+
+
+/**
+ * Entry point to this code when a new device is created. Allocate the basic
+ * structures, and watch the store waiting for the hotplug scripts to tell us
+ * the device's handle. Switch to InitWait.
+ */
+static int netback_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ const char *message;
+ struct xenbus_transaction xbt;
+ int err;
+ struct backend_info *be = kzalloc(sizeof(struct backend_info),
+ GFP_KERNEL);
+ if (!be) {
+ xenbus_dev_fatal(dev, -ENOMEM,
+ "allocating backend structure");
+ return -ENOMEM;
+ }
+
+ be->dev = dev;
+ dev->dev.driver_data = be;
+
+ err = xenbus_watch_path2(dev, dev->nodename, "handle",
+ &be->backend_watch, backend_changed);
+ if (err)
+ goto fail;
+
+ do {
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "starting transaction");
+ goto fail;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
+ if (err) {
+ message = "writing feature-sg";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
+ "%d", 1);
+ if (err) {
+ message = "writing feature-gso-tcpv4";
+ goto abort_transaction;
+ }
+
+ err = xenbus_transaction_end(xbt, 0);
+ } while (err == -EAGAIN);
+
+ if (err) {
+ xenbus_dev_fatal(dev, err, "completing transaction");
+ goto fail;
+ }
+
+ err = xenbus_switch_state(dev, XenbusStateInitWait);
+ if (err) {
+ goto fail;
+ }
+
+ return 0;
+
+abort_transaction:
+ xenbus_transaction_end(xbt, 1);
+ xenbus_dev_fatal(dev, err, "%s", message);
+fail:
+ DPRINTK("failed");
+ netback_remove(dev);
+ return err;
+}
+
+
+/**
+ * Handle the creation of the hotplug script environment. We add the script
+ * and vif variables to the environment, for the benefit of the vif-* hotplug
+ * scripts.
+ */
+static int netback_uevent(struct xenbus_device *xdev, char **envp,
+ int num_envp, char *buffer, int buffer_size)
+{
+ struct backend_info *be = xdev->dev.driver_data;
+ netif_t *netif = be->netif;
+ int i = 0, length = 0;
+ char *val;
+
+ DPRINTK("netback_uevent");
+
+ val = xenbus_read(XBT_NIL, xdev->nodename, "script", NULL);
+ if (IS_ERR(val)) {
+ int err = PTR_ERR(val);
+ xenbus_dev_fatal(xdev, err, "reading script");
+ return err;
+ }
+ else {
+ add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
+ &length, "script=%s", val);
+ kfree(val);
+ }
+
+ add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
+ "vif=%s", netif->dev->name);
+
+ envp[i] = NULL;
+
+ return 0;
+}
+
+
+/**
+ * Callback received when the hotplug scripts have placed the handle node.
+ * Read it, and create a netif structure. If the frontend is ready, connect.
+ */
+static void backend_changed(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ int err;
+ long handle;
+ struct backend_info *be
+ = container_of(watch, struct backend_info, backend_watch);
+ struct xenbus_device *dev = be->dev;
+
+ DPRINTK("");
+
+ err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
+ if (XENBUS_EXIST_ERR(err)) {
+ /* Since this watch will fire once immediately after it is
+ registered, we expect this. Ignore it, and wait for the
+ hotplug scripts. */
+ return;
+ }
+ if (err != 1) {
+ xenbus_dev_fatal(dev, err, "reading handle");
+ return;
+ }
+
+ if (be->netif == NULL) {
+ u8 be_mac[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
+
+ be->netif = netif_alloc(dev->otherend_id, handle, be_mac);
+ if (IS_ERR(be->netif)) {
+ err = PTR_ERR(be->netif);
+ be->netif = NULL;
+ xenbus_dev_fatal(dev, err, "creating interface");
+ return;
+ }
+
+ kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
+
+ maybe_connect(be);
+ }
+}
+
+
+/**
+ * Callback received when the frontend's state changes.
+ */
+static void frontend_changed(struct xenbus_device *dev,
+ enum xenbus_state frontend_state)
+{
+ struct backend_info *be = dev->dev.driver_data;
+
+ DPRINTK("");
+
+ be->frontend_state = frontend_state;
+
+ switch (frontend_state) {
+ case XenbusStateInitialising:
+ case XenbusStateInitialised:
+ break;
+
+ case XenbusStateConnected:
+ maybe_connect(be);
+ break;
+
+ case XenbusStateClosing:
+ xenbus_switch_state(dev, XenbusStateClosing);
+ break;
+
+ case XenbusStateClosed:
+ if (be->netif != NULL)
+ kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
+ device_unregister(&dev->dev);
+ break;
+
+ case XenbusStateUnknown:
+ case XenbusStateInitWait:
+ default:
+ xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
+ frontend_state);
+ break;
+ }
+}
+
+
+/* ** Connection ** */
+
+
+static void maybe_connect(struct backend_info *be)
+{
+ if (be->netif && (be->frontend_state == XenbusStateConnected))
+ connect(be);
+}
+
+static void xen_net_read_rate(struct xenbus_device *dev,
+ unsigned long *bytes, unsigned long *usec)
+{
+ char *s, *e;
+ unsigned long b, u;
+ char *ratestr;
+
+ /* Default to unlimited bandwidth. */
+ *bytes = ~0UL;
+ *usec = 0;
+
+ ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
+ if (IS_ERR(ratestr))
+ return;
+
+ s = ratestr;
+ b = simple_strtoul(s, &e, 10);
+ if ((s == e) || (*e != ','))
+ goto fail;
+
+ s = e + 1;
+ u = simple_strtoul(s, &e, 10);
+ if ((s == e) || (*e != '\0'))
+ goto fail;
+
+ *bytes = b;
+ *usec = u;
+
+ kfree(ratestr);
+ return;
+
+ fail:
+ WPRINTK("Failed to parse network rate limit. Traffic unlimited.\n");
+ kfree(ratestr);
+}
+
+static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
+{
+ char *s, *e, *macstr;
+ int i;
+
+ macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
+ if (IS_ERR(macstr))
+ return PTR_ERR(macstr);
+
+ for (i = 0; i < ETH_ALEN; i++) {
+ mac[i] = simple_strtoul(s, &e, 16);
+ if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
+ kfree(macstr);
+ return -ENOENT;
+ }
+ s = e+1;
+ }
+
+ kfree(macstr);
+ return 0;
+}
+
+static void connect(struct backend_info *be)
+{
+ int err;
+ struct xenbus_device *dev = be->dev;
+
+ err = connect_rings(be);
+ if (err)
+ return;
+
+ err = xen_net_read_mac(dev, be->netif->fe_dev_addr);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
+ return;
+ }
+
+ xen_net_read_rate(dev, &be->netif->credit_bytes,
+ &be->netif->credit_usec);
+ be->netif->remaining_credit = be->netif->credit_bytes;
+
+ xenbus_switch_state(dev, XenbusStateConnected);
+}
+
+
+static int connect_rings(struct backend_info *be)
+{
+ struct xenbus_device *dev = be->dev;
+ unsigned long tx_ring_ref, rx_ring_ref;
+ unsigned int evtchn;
+ int err;
+ int val;
+
+ DPRINTK("");
+
+ err = xenbus_gather(XBT_NIL, dev->otherend,
+ "tx-ring-ref", "%lu", &tx_ring_ref,
+ "rx-ring-ref", "%lu", &rx_ring_ref,
+ "event-channel", "%u", &evtchn, NULL);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "reading %s/ring-ref and event-channel",
+ dev->otherend);
+ return err;
+ }
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-rx-notify", "%d",
+ &val) < 0)
+ val = 0;
+ if (val)
+ be->netif->can_queue = 1;
+ else
+ /* Must be non-zero for pfifo_fast to work. */
+ be->netif->dev->tx_queue_len = 1;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg", "%d", &val) < 0)
+ val = 0;
+ if (val) {
+ be->netif->features |= NETIF_F_SG;
+ be->netif->dev->features |= NETIF_F_SG;
+ }
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4", "%d",
+ &val) < 0)
+ val = 0;
+ if (val) {
+ be->netif->features |= NETIF_F_TSO;
+ be->netif->dev->features |= NETIF_F_TSO;
+ }
+
+ /* Map the shared frame, irq etc. */
+ err = netif_map(be->netif, tx_ring_ref, rx_ring_ref, evtchn);
+ if (err) {
+ xenbus_dev_fatal(dev, err,
+ "mapping shared-frames %lu/%lu port %u",
+ tx_ring_ref, rx_ring_ref, evtchn);
+ return err;
+ }
+ return 0;
+}
+
+
+/* ** Driver Registration ** */
+
+
+static struct xenbus_device_id netback_ids[] = {
+ { "vif" },
+ { "" }
+};
+
+
+static struct xenbus_driver netback = {
+ .name = "vif",
+ .owner = THIS_MODULE,
+ .ids = netback_ids,
+ .probe = netback_probe,
+ .remove = netback_remove,
+ .uevent = netback_uevent,
+ .otherend_changed = frontend_changed,
+};
+
+
+void netif_xenbus_init(void)
+{
+ xenbus_register_backend(&netback);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff