uwb: add the WiMedia LLC Protocol stack

Add the generic code for the WiMedia Logical Link Control Protocol (WLP).

This has been split into several patches for easier review.

core (this patch):
  - everything else

messages:
  - WLP message construction/decode

wss:
  - Wireless Service Set support

build-system:
  - Kconfig and Kbuild files

Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 585 insertions, 0 deletions

diff --git a/drivers/uwb/wlp/wlp-lc.c b/drivers/uwb/wlp/wlp-lc.c
new file mode 100644
index 000000000000..0799402e73fb
--- /dev/null
+++ b/drivers/uwb/wlp/wlp-lc.c
@@ -0,0 +1,585 @@
+/*
+ * WiMedia Logical Link Control Protocol (WLP)
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Reinette Chatre <reinette.chatre@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ * FIXME: docs
+ */
+
+#include <linux/wlp.h>
+#define D_LOCAL 6
+#include <linux/uwb/debug.h>
+#include "wlp-internal.h"
+
+
+static
+void wlp_neighbor_init(struct wlp_neighbor_e *neighbor)
+{
+	INIT_LIST_HEAD(&neighbor->wssid);
+}
+
+/**
+ * Create area for device information storage
+ *
+ * wlp->mutex must be held
+ */
+int __wlp_alloc_device_info(struct wlp *wlp)
+{
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+	BUG_ON(wlp->dev_info != NULL);
+	wlp->dev_info = kzalloc(sizeof(struct wlp_device_info), GFP_KERNEL);
+	if (wlp->dev_info == NULL) {
+		dev_err(dev, "WLP: Unable to allocate memory for "
+			"device information.\n");
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+
+/**
+ * Fill in device information using function provided by driver
+ *
+ * wlp->mutex must be held
+ */
+static
+void __wlp_fill_device_info(struct wlp *wlp)
+{
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+
+	BUG_ON(wlp->fill_device_info == NULL);
+	d_printf(6, dev, "Retrieving device information "
+			 "from device driver.\n");
+	wlp->fill_device_info(wlp, wlp->dev_info);
+}
+
+/**
+ * Setup device information
+ *
+ * Allocate area for device information and populate it.
+ *
+ * wlp->mutex must be held
+ */
+int __wlp_setup_device_info(struct wlp *wlp)
+{
+	int result;
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+
+	result = __wlp_alloc_device_info(wlp);
+	if (result < 0) {
+		dev_err(dev, "WLP: Unable to allocate area for "
+			"device information.\n");
+		return result;
+	}
+	__wlp_fill_device_info(wlp);
+	return 0;
+}
+
+/**
+ * Remove information about neighbor stored temporarily
+ *
+ * Information learned during discovey should only be stored when the
+ * device enrolls in the neighbor's WSS. We do need to store this
+ * information temporarily in order to present it to the user.
+ *
+ * We are only interested in keeping neighbor WSS information if that
+ * neighbor is accepting enrollment.
+ *
+ * should be called with wlp->nbmutex held
+ */
+void wlp_remove_neighbor_tmp_info(struct wlp_neighbor_e *neighbor)
+{
+	struct wlp_wssid_e *wssid_e, *next;
+	u8 keep;
+	if (!list_empty(&neighbor->wssid)) {
+		list_for_each_entry_safe(wssid_e, next, &neighbor->wssid,
+					 node) {
+			if (wssid_e->info != NULL) {
+				keep = wssid_e->info->accept_enroll;
+				kfree(wssid_e->info);
+				wssid_e->info = NULL;
+				if (!keep) {
+					list_del(&wssid_e->node);
+					kfree(wssid_e);
+				}
+			}
+		}
+	}
+	if (neighbor->info != NULL) {
+		kfree(neighbor->info);
+		neighbor->info = NULL;
+	}
+}
+
+/**
+ * Populate WLP neighborhood cache with neighbor information
+ *
+ * A new neighbor is found. If it is discoverable then we add it to the
+ * neighborhood cache.
+ *
+ */
+static
+int wlp_add_neighbor(struct wlp *wlp, struct uwb_dev *dev)
+{
+	int result = 0;
+	int discoverable;
+	struct wlp_neighbor_e *neighbor;
+
+	d_fnstart(6, &dev->dev, "uwb %p \n", dev);
+	d_printf(6, &dev->dev, "Found neighbor device %02x:%02x \n",
+		 dev->dev_addr.data[1], dev->dev_addr.data[0]);
+	/**
+	 * FIXME:
+	 * Use contents of WLP IE found in beacon cache to determine if
+	 * neighbor is discoverable.
+	 * The device does not support WLP IE yet so this still needs to be
+	 * done. Until then we assume all devices are discoverable.
+	 */
+	discoverable = 1; /* will be changed when FIXME disappears */
+	if (discoverable) {
+		/* Add neighbor to cache for discovery */
+		neighbor = kzalloc(sizeof(*neighbor), GFP_KERNEL);
+		if (neighbor == NULL) {
+			dev_err(&dev->dev, "Unable to create memory for "
+				"new neighbor. \n");
+			result = -ENOMEM;
+			goto error_no_mem;
+		}
+		wlp_neighbor_init(neighbor);
+		uwb_dev_get(dev);
+		neighbor->uwb_dev = dev;
+		list_add(&neighbor->node, &wlp->neighbors);
+	}
+error_no_mem:
+	d_fnend(6, &dev->dev, "uwb %p, result = %d \n", dev, result);
+	return result;
+}
+
+/**
+ * Remove one neighbor from cache
+ */
+static
+void __wlp_neighbor_release(struct wlp_neighbor_e *neighbor)
+{
+	struct wlp_wssid_e *wssid_e, *next_wssid_e;
+
+	list_for_each_entry_safe(wssid_e, next_wssid_e,
+				 &neighbor->wssid, node) {
+		list_del(&wssid_e->node);
+		kfree(wssid_e);
+	}
+	uwb_dev_put(neighbor->uwb_dev);
+	list_del(&neighbor->node);
+	kfree(neighbor);
+}
+
+/**
+ * Clear entire neighborhood cache.
+ */
+static
+void __wlp_neighbors_release(struct wlp *wlp)
+{
+	struct wlp_neighbor_e *neighbor, *next;
+	if (list_empty(&wlp->neighbors))
+		return;
+	list_for_each_entry_safe(neighbor, next, &wlp->neighbors, node) {
+		__wlp_neighbor_release(neighbor);
+	}
+}
+
+static
+void wlp_neighbors_release(struct wlp *wlp)
+{
+	mutex_lock(&wlp->nbmutex);
+	__wlp_neighbors_release(wlp);
+	mutex_unlock(&wlp->nbmutex);
+}
+
+
+
+/**
+ * Send D1 message to neighbor, receive D2 message
+ *
+ * @neighbor: neighbor to which D1 message will be sent
+ * @wss:      if not NULL, it is an enrollment request for this WSS
+ * @wssid:    if wss not NULL, this is the wssid of the WSS in which we
+ *            want to enroll
+ *
+ * A D1/D2 exchange is done for one of two reasons: discovery or
+ * enrollment. If done for discovery the D1 message is sent to the neighbor
+ * and the contents of the D2 response is stored in a temporary cache.
+ * If done for enrollment the @wss and @wssid are provided also. In this
+ * case the D1 message is sent to the neighbor, the D2 response is parsed
+ * for enrollment of the WSS with wssid.
+ *
+ * &wss->mutex is held
+ */
+static
+int wlp_d1d2_exchange(struct wlp *wlp, struct wlp_neighbor_e *neighbor,
+		      struct wlp_wss *wss, struct wlp_uuid *wssid)
+{
+	int result;
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+	DECLARE_COMPLETION_ONSTACK(completion);
+	struct wlp_session session;
+	struct sk_buff  *skb;
+	struct wlp_frame_assoc *resp;
+	struct uwb_dev_addr *dev_addr = &neighbor->uwb_dev->dev_addr;
+
+	mutex_lock(&wlp->mutex);
+	if (!wlp_uuid_is_set(&wlp->uuid)) {
+		dev_err(dev, "WLP: UUID is not set. Set via sysfs to "
+			"proceed.\n");
+		result = -ENXIO;
+		goto out;
+	}
+	/* Send D1 association frame */
+	result = wlp_send_assoc_frame(wlp, wss, dev_addr, WLP_ASSOC_D1);
+	if (result < 0) {
+		dev_err(dev, "Unable to send D1 frame to neighbor "
+			"%02x:%02x (%d)\n", dev_addr->data[1],
+			dev_addr->data[0], result);
+		d_printf(6, dev, "Add placeholders into buffer next to "
+			 "neighbor information we have (dev address).\n");
+		goto out;
+	}
+	/* Create session, wait for response */
+	session.exp_message = WLP_ASSOC_D2;
+	session.cb = wlp_session_cb;
+	session.cb_priv = &completion;
+	session.neighbor_addr = *dev_addr;
+	BUG_ON(wlp->session != NULL);
+	wlp->session = &session;
+	/* Wait for D2/F0 frame */
+	result = wait_for_completion_interruptible_timeout(&completion,
+						   WLP_PER_MSG_TIMEOUT * HZ);
+	if (result == 0) {
+		result = -ETIMEDOUT;
+		dev_err(dev, "Timeout while sending D1 to neighbor "
+			     "%02x:%02x.\n", dev_addr->data[1],
+			     dev_addr->data[0]);
+		goto error_session;
+	}
+	if (result < 0) {
+		dev_err(dev, "Unable to discover/enroll neighbor %02x:%02x.\n",
+			dev_addr->data[1], dev_addr->data[0]);
+		goto error_session;
+	}
+	/* Parse message in session->data: it will be either D2 or F0 */
+	skb = session.data;
+	resp = (void *) skb->data;
+	d_printf(6, dev, "Received response to D1 frame. \n");
+	d_dump(6, dev, skb->data, skb->len > 72 ? 72 : skb->len);
+
+	if (resp->type == WLP_ASSOC_F0) {
+		result = wlp_parse_f0(wlp, skb);
+		if (result < 0)
+			dev_err(dev, "WLP: Unable to parse F0 from neighbor "
+				"%02x:%02x.\n", dev_addr->data[1],
+				dev_addr->data[0]);
+		result = -EINVAL;
+		goto error_resp_parse;
+	}
+	if (wss == NULL) {
+		/* Discovery */
+		result = wlp_parse_d2_frame_to_cache(wlp, skb, neighbor);
+		if (result < 0) {
+			dev_err(dev, "WLP: Unable to parse D2 message from "
+				"neighbor %02x:%02x for discovery.\n",
+				dev_addr->data[1], dev_addr->data[0]);
+			goto error_resp_parse;
+		}
+	} else {
+		/* Enrollment */
+		result = wlp_parse_d2_frame_to_enroll(wss, skb, neighbor,
+						      wssid);
+		if (result < 0) {
+			dev_err(dev, "WLP: Unable to parse D2 message from "
+				"neighbor %02x:%02x for enrollment.\n",
+				dev_addr->data[1], dev_addr->data[0]);
+			goto error_resp_parse;
+		}
+	}
+error_resp_parse:
+	kfree_skb(skb);
+error_session:
+	wlp->session = NULL;
+out:
+	mutex_unlock(&wlp->mutex);
+	return result;
+}
+
+/**
+ * Enroll into WSS of provided WSSID by using neighbor as registrar
+ *
+ * &wss->mutex is held
+ */
+int wlp_enroll_neighbor(struct wlp *wlp, struct wlp_neighbor_e *neighbor,
+			struct wlp_wss *wss, struct wlp_uuid *wssid)
+{
+	int result = 0;
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+	char buf[WLP_WSS_UUID_STRSIZE];
+	struct uwb_dev_addr *dev_addr = &neighbor->uwb_dev->dev_addr;
+	wlp_wss_uuid_print(buf, sizeof(buf), wssid);
+	d_fnstart(6, dev, "wlp %p, neighbor %p, wss %p, wssid %p (%s)\n",
+		  wlp, neighbor, wss, wssid, buf);
+	d_printf(6, dev, "Complete me.\n");
+	result =  wlp_d1d2_exchange(wlp, neighbor, wss, wssid);
+	if (result < 0) {
+		dev_err(dev, "WLP: D1/D2 message exchange for enrollment "
+			"failed. result = %d \n", result);
+		goto out;
+	}
+	if (wss->state != WLP_WSS_STATE_PART_ENROLLED) {
+		dev_err(dev, "WLP: Unable to enroll into WSS %s using "
+			"neighbor %02x:%02x. \n", buf,
+			dev_addr->data[1], dev_addr->data[0]);
+		result = -EINVAL;
+		goto out;
+	}
+	if (wss->secure_status == WLP_WSS_SECURE) {
+		dev_err(dev, "FIXME: need to complete secure enrollment.\n");
+		result = -EINVAL;
+		goto error;
+	} else {
+		wss->state = WLP_WSS_STATE_ENROLLED;
+		d_printf(2, dev, "WLP: Success Enrollment into unsecure WSS "
+			 "%s using neighbor %02x:%02x. \n", buf,
+			 dev_addr->data[1], dev_addr->data[0]);
+	}
+
+	d_fnend(6, dev, "wlp %p, neighbor %p, wss %p, wssid %p (%s)\n",
+		  wlp, neighbor, wss, wssid, buf);
+out:
+	return result;
+error:
+	wlp_wss_reset(wss);
+	return result;
+}
+
+/**
+ * Discover WSS information of neighbor's active WSS
+ */
+static
+int wlp_discover_neighbor(struct wlp *wlp,
+			  struct wlp_neighbor_e *neighbor)
+{
+	return wlp_d1d2_exchange(wlp, neighbor, NULL, NULL);
+}
+
+
+/**
+ * Each neighbor in the neighborhood cache is discoverable. Discover it.
+ *
+ * Discovery is done through sending of D1 association frame and parsing
+ * the D2 association frame response. Only wssid from D2 will be included
+ * in neighbor cache, rest is just displayed to user and forgotten.
+ *
+ * The discovery is not done in parallel. This is simple and enables us to
+ * maintain only one association context.
+ *
+ * The discovery of one neighbor does not affect the other, but if the
+ * discovery of a neighbor fails it is removed from the neighborhood cache.
+ */
+static
+int wlp_discover_all_neighbors(struct wlp *wlp)
+{
+	int result = 0;
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+	struct wlp_neighbor_e *neighbor, *next;
+
+	list_for_each_entry_safe(neighbor, next, &wlp->neighbors, node) {
+		result = wlp_discover_neighbor(wlp, neighbor);
+		if (result < 0) {
+			dev_err(dev, "WLP: Unable to discover neighbor "
+				"%02x:%02x, removing from neighborhood. \n",
+				neighbor->uwb_dev->dev_addr.data[1],
+				neighbor->uwb_dev->dev_addr.data[0]);
+			__wlp_neighbor_release(neighbor);
+		}
+	}
+	return result;
+}
+
+static int wlp_add_neighbor_helper(struct device *dev, void *priv)
+{
+	struct wlp *wlp = priv;
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+
+	return wlp_add_neighbor(wlp, uwb_dev);
+}
+
+/**
+ * Discover WLP neighborhood
+ *
+ * Will send D1 association frame to all devices in beacon group that have
+ * discoverable bit set in WLP IE. D2 frames will be received, information
+ * displayed to user in @buf. Partial information (from D2 association
+ * frame) will be cached to assist with future association
+ * requests.
+ *
+ * The discovery of the WLP neighborhood is triggered by the user. This
+ * should occur infrequently and we thus free current cache and re-allocate
+ * memory if needed.
+ *
+ * If one neighbor fails during initial discovery (determining if it is a
+ * neighbor or not), we fail all - note that interaction with neighbor has
+ * not occured at this point so if a failure occurs we know something went wrong
+ * locally. We thus undo everything.
+ */
+ssize_t wlp_discover(struct wlp *wlp)
+{
+	int result = 0;
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+
+	d_fnstart(6, dev, "wlp %p \n", wlp);
+	mutex_lock(&wlp->nbmutex);
+	/* Clear current neighborhood cache. */
+	__wlp_neighbors_release(wlp);
+	/* Determine which devices in neighborhood. Repopulate cache. */
+	result = uwb_dev_for_each(wlp->rc, wlp_add_neighbor_helper, wlp);
+	if (result < 0) {
+		/* May have partial neighbor information, release all. */
+		__wlp_neighbors_release(wlp);
+		goto error_dev_for_each;
+	}
+	/* Discover the properties of devices in neighborhood. */
+	result = wlp_discover_all_neighbors(wlp);
+	/* In case of failure we still print our partial results. */
+	if (result < 0) {
+		dev_err(dev, "Unable to fully discover neighborhood. \n");
+		result = 0;
+	}
+error_dev_for_each:
+	mutex_unlock(&wlp->nbmutex);
+	d_fnend(6, dev, "wlp %p \n", wlp);
+	return result;
+}
+
+/**
+ * Handle events from UWB stack
+ *
+ * We handle events conservatively. If a neighbor goes off the air we
+ * remove it from the neighborhood. If an association process is in
+ * progress this function will block waiting for the nbmutex to become
+ * free. The association process will thus be allowed to complete before it
+ * is removed.
+ */
+static
+void wlp_uwb_notifs_cb(void *_wlp, struct uwb_dev *uwb_dev,
+		       enum uwb_notifs event)
+{
+	struct wlp *wlp = _wlp;
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+	struct wlp_neighbor_e *neighbor, *next;
+	int result;
+	switch (event) {
+	case UWB_NOTIF_ONAIR:
+		d_printf(6, dev, "UWB device %02x:%02x is onair\n",
+				uwb_dev->dev_addr.data[1],
+				uwb_dev->dev_addr.data[0]);
+		result = wlp_eda_create_node(&wlp->eda,
+					     uwb_dev->mac_addr.data,
+					     &uwb_dev->dev_addr);
+		if (result < 0)
+			dev_err(dev, "WLP: Unable to add new neighbor "
+				"%02x:%02x to EDA cache.\n",
+				uwb_dev->dev_addr.data[1],
+				uwb_dev->dev_addr.data[0]);
+		break;
+	case UWB_NOTIF_OFFAIR:
+		d_printf(6, dev, "UWB device %02x:%02x is offair\n",
+				uwb_dev->dev_addr.data[1],
+				uwb_dev->dev_addr.data[0]);
+		wlp_eda_rm_node(&wlp->eda, &uwb_dev->dev_addr);
+		mutex_lock(&wlp->nbmutex);
+		list_for_each_entry_safe(neighbor, next, &wlp->neighbors,
+					 node) {
+			if (neighbor->uwb_dev == uwb_dev) {
+				d_printf(6, dev, "Removing device from "
+					 "neighborhood.\n");
+				__wlp_neighbor_release(neighbor);
+			}
+		}
+		mutex_unlock(&wlp->nbmutex);
+		break;
+	default:
+		dev_err(dev, "don't know how to handle event %d from uwb\n",
+				event);
+	}
+}
+
+int wlp_setup(struct wlp *wlp, struct uwb_rc *rc)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	int result;
+
+	d_fnstart(6, dev, "wlp %p\n", wlp);
+	BUG_ON(wlp->fill_device_info == NULL);
+	BUG_ON(wlp->xmit_frame == NULL);
+	BUG_ON(wlp->stop_queue == NULL);
+	BUG_ON(wlp->start_queue == NULL);
+	wlp->rc = rc;
+	wlp_eda_init(&wlp->eda);/* Set up address cache */
+	wlp->uwb_notifs_handler.cb = wlp_uwb_notifs_cb;
+	wlp->uwb_notifs_handler.data = wlp;
+	uwb_notifs_register(rc, &wlp->uwb_notifs_handler);
+
+	uwb_pal_init(&wlp->pal);
+	result = uwb_pal_register(rc, &wlp->pal);
+	if (result < 0)
+		uwb_notifs_deregister(wlp->rc, &wlp->uwb_notifs_handler);
+
+	d_fnend(6, dev, "wlp %p, result = %d\n", wlp, result);
+	return result;
+}
+EXPORT_SYMBOL_GPL(wlp_setup);
+
+void wlp_remove(struct wlp *wlp)
+{
+	struct device *dev = &wlp->rc->uwb_dev.dev;
+	d_fnstart(6, dev, "wlp %p\n", wlp);
+	wlp_neighbors_release(wlp);
+	uwb_pal_unregister(wlp->rc, &wlp->pal);
+	uwb_notifs_deregister(wlp->rc, &wlp->uwb_notifs_handler);
+	wlp_eda_release(&wlp->eda);
+	mutex_lock(&wlp->mutex);
+	if (wlp->dev_info != NULL)
+		kfree(wlp->dev_info);
+	mutex_unlock(&wlp->mutex);
+	wlp->rc = NULL;
+	/* We have to use NULL here because this function can be called
+	 * when the device disappeared. */
+	d_fnend(6, NULL, "wlp %p\n", wlp);
+}
+EXPORT_SYMBOL_GPL(wlp_remove);
+
+/**
+ * wlp_reset_all - reset the WLP hardware
+ * @wlp: the WLP device to reset.
+ *
+ * This schedules a full hardware reset of the WLP device.  The radio
+ * controller and any other PALs will also be reset.
+ */
+void wlp_reset_all(struct wlp *wlp)
+{
+	uwb_rc_reset_all(wlp->rc);
+}
+EXPORT_SYMBOL_GPL(wlp_reset_all);