1 files changed, 366 insertions, 0 deletions
diff --git a/drivers/staging/uwb/ie.c b/drivers/staging/uwb/ie.c
new file mode 100644
index 000000000000..b11678dd0380
--- /dev/null
+++ b/drivers/staging/uwb/ie.c
@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Ultra Wide Band
+ * Information Element Handling
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ * Reinette Chatre <reinette.chatre@intel.com>
+ *
+ * FIXME: docs
+ */
+
+#include <linux/slab.h>
+#include <linux/export.h>
+#include "uwb-internal.h"
+
+/**
+ * uwb_ie_next - get the next IE in a buffer
+ * @ptr: start of the buffer containing the IE data
+ * @len: length of the buffer
+ *
+ * Both @ptr and @len are updated so subsequent calls to uwb_ie_next()
+ * will get the next IE.
+ *
+ * NULL is returned (and @ptr and @len will not be updated) if there
+ * are no more IEs in the buffer or the buffer is too short.
+ */
+struct uwb_ie_hdr *uwb_ie_next(void **ptr, size_t *len)
+{
+	struct uwb_ie_hdr *hdr;
+	size_t ie_len;
+
+	if (*len < sizeof(struct uwb_ie_hdr))
+		return NULL;
+
+	hdr = *ptr;
+	ie_len = sizeof(struct uwb_ie_hdr) + hdr->length;
+
+	if (*len < ie_len)
+		return NULL;
+
+	*ptr += ie_len;
+	*len -= ie_len;
+
+	return hdr;
+}
+EXPORT_SYMBOL_GPL(uwb_ie_next);
+
+/**
+ * uwb_ie_dump_hex - print IEs to a character buffer
+ * @ies: the IEs to print.
+ * @len: length of all the IEs.
+ * @buf: the destination buffer.
+ * @size: size of @buf.
+ *
+ * Returns the number of characters written.
+ */
+int uwb_ie_dump_hex(const struct uwb_ie_hdr *ies, size_t len,
+		    char *buf, size_t size)
+{
+	void *ptr;
+	const struct uwb_ie_hdr *ie;
+	int r = 0;
+	u8 *d;
+
+	ptr = (void *)ies;
+	for (;;) {
+		ie = uwb_ie_next(&ptr, &len);
+		if (!ie)
+			break;
+
+		r += scnprintf(buf + r, size - r, "%02x %02x",
+			       (unsigned)ie->element_id,
+			       (unsigned)ie->length);
+		d = (uint8_t *)ie + sizeof(struct uwb_ie_hdr);
+		while (d != ptr && r < size)
+			r += scnprintf(buf + r, size - r, " %02x", (unsigned)*d++);
+		if (r < size)
+			buf[r++] = '\n';
+	};
+
+	return r;
+}
+
+/**
+ * Get the IEs that a radio controller is sending in its beacon
+ *
+ * @uwb_rc:  UWB Radio Controller
+ * @returns: Size read from the system
+ *
+ * We don't need to lock the uwb_rc's mutex because we don't modify
+ * anything. Once done with the iedata buffer, call
+ * uwb_rc_ie_release(iedata). Don't call kfree on it.
+ */
+static
+ssize_t uwb_rc_get_ie(struct uwb_rc *uwb_rc, struct uwb_rc_evt_get_ie **pget_ie)
+{
+	ssize_t result;
+	struct device *dev = &uwb_rc->uwb_dev.dev;
+	struct uwb_rccb *cmd = NULL;
+	struct uwb_rceb *reply = NULL;
+	struct uwb_rc_evt_get_ie *get_ie;
+
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (cmd == NULL)
+		return -ENOMEM;
+
+	cmd->bCommandType = UWB_RC_CET_GENERAL;
+	cmd->wCommand = cpu_to_le16(UWB_RC_CMD_GET_IE);
+	result = uwb_rc_vcmd(uwb_rc, "GET_IE", cmd, sizeof(*cmd),
+			     UWB_RC_CET_GENERAL, UWB_RC_CMD_GET_IE,
+			     &reply);
+	kfree(cmd);
+	if (result < 0)
+		return result;
+
+	get_ie = container_of(reply, struct uwb_rc_evt_get_ie, rceb);
+	if (result < sizeof(*get_ie)) {
+		dev_err(dev, "not enough data returned for decoding GET IE "
+			"(%zu bytes received vs %zu needed)\n",
+			result, sizeof(*get_ie));
+		return -EINVAL;
+	} else if (result < sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength)) {
+		dev_err(dev, "not enough data returned for decoding GET IE "
+			"payload (%zu bytes received vs %zu needed)\n", result,
+			sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength));
+		return -EINVAL;
+	}
+
+	*pget_ie = get_ie;
+	return result;
+}
+
+
+/**
+ * Replace all IEs currently being transmitted by a device
+ *
+ * @cmd:    pointer to the SET-IE command with the IEs to set
+ * @size:   size of @buf
+ */
+int uwb_rc_set_ie(struct uwb_rc *rc, struct uwb_rc_cmd_set_ie *cmd)
+{
+	int result;
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_rc_evt_set_ie reply;
+
+	reply.rceb.bEventType = UWB_RC_CET_GENERAL;
+	reply.rceb.wEvent = UWB_RC_CMD_SET_IE;
+	result = uwb_rc_cmd(rc, "SET-IE", &cmd->rccb,
+			    sizeof(*cmd) + le16_to_cpu(cmd->wIELength),
+			    &reply.rceb, sizeof(reply));
+	if (result < 0)
+		goto error_cmd;
+	else if (result != sizeof(reply)) {
+		dev_err(dev, "SET-IE: not enough data to decode reply "
+			"(%d bytes received vs %zu needed)\n",
+			result, sizeof(reply));
+		result = -EIO;
+	} else if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
+		dev_err(dev, "SET-IE: command execution failed: %s (%d)\n",
+			uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
+		result = -EIO;
+	} else
+		result = 0;
+error_cmd:
+	return result;
+}
+
+/* Cleanup the whole IE management subsystem */
+void uwb_rc_ie_init(struct uwb_rc *uwb_rc)
+{
+	mutex_init(&uwb_rc->ies_mutex);
+}
+
+
+/**
+ * uwb_rc_ie_setup - setup a radio controller's IE manager
+ * @uwb_rc: the radio controller.
+ *
+ * The current set of IEs are obtained from the hardware with a GET-IE
+ * command (since the radio controller is not yet beaconing this will
+ * be just the hardware's MAC and PHY Capability IEs).
+ *
+ * Returns 0 on success; -ve on an error.
+ */
+int uwb_rc_ie_setup(struct uwb_rc *uwb_rc)
+{
+	struct uwb_rc_evt_get_ie *ie_info = NULL;
+	int capacity;
+
+	capacity = uwb_rc_get_ie(uwb_rc, &ie_info);
+	if (capacity < 0)
+		return capacity;
+
+	mutex_lock(&uwb_rc->ies_mutex);
+
+	uwb_rc->ies = (struct uwb_rc_cmd_set_ie *)ie_info;
+	uwb_rc->ies->rccb.bCommandType = UWB_RC_CET_GENERAL;
+	uwb_rc->ies->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_IE);
+	uwb_rc->ies_capacity = capacity;
+
+	mutex_unlock(&uwb_rc->ies_mutex);
+
+	return 0;
+}
+
+
+/* Cleanup the whole IE management subsystem */
+void uwb_rc_ie_release(struct uwb_rc *uwb_rc)
+{
+	kfree(uwb_rc->ies);
+	uwb_rc->ies = NULL;
+	uwb_rc->ies_capacity = 0;
+}
+
+
+static int uwb_rc_ie_add_one(struct uwb_rc *rc, const struct uwb_ie_hdr *new_ie)
+{
+	struct uwb_rc_cmd_set_ie *new_ies;
+	void *ptr, *prev_ie;
+	struct uwb_ie_hdr *ie;
+	size_t length, new_ie_len, new_capacity, size, prev_size;
+
+	length = le16_to_cpu(rc->ies->wIELength);
+	new_ie_len = sizeof(struct uwb_ie_hdr) + new_ie->length;
+	new_capacity = sizeof(struct uwb_rc_cmd_set_ie) + length + new_ie_len;
+
+	if (new_capacity > rc->ies_capacity) {
+		new_ies = krealloc(rc->ies, new_capacity, GFP_KERNEL);
+		if (!new_ies)
+			return -ENOMEM;
+		rc->ies = new_ies;
+	}
+
+	ptr = rc->ies->IEData;
+	size = length;
+	for (;;) {
+		prev_ie = ptr;
+		prev_size = size;
+		ie = uwb_ie_next(&ptr, &size);
+		if (!ie || ie->element_id > new_ie->element_id)
+			break;
+	}
+
+	memmove(prev_ie + new_ie_len, prev_ie, prev_size);
+	memcpy(prev_ie, new_ie, new_ie_len);
+	rc->ies->wIELength = cpu_to_le16(length + new_ie_len);
+
+	return 0;
+}
+
+/**
+ * uwb_rc_ie_add - add new IEs to the radio controller's beacon
+ * @uwb_rc: the radio controller.
+ * @ies: the buffer containing the new IE or IEs to be added to
+ *       the device's beacon.
+ * @size: length of all the IEs.
+ *
+ * According to WHCI 0.95 [4.13.6] the driver will only receive the RCEB
+ * after the device sent the first beacon that includes the IEs specified
+ * in the SET IE command. We thus cannot send this command if the device is
+ * not beaconing. Instead, a SET IE command will be sent later right after
+ * we start beaconing.
+ *
+ * Setting an IE on the device will overwrite all current IEs in device. So
+ * we take the current IEs being transmitted by the device, insert the
+ * new one, and call SET IE with all the IEs needed.
+ *
+ * Returns 0 on success; or -ENOMEM.
+ */
+int uwb_rc_ie_add(struct uwb_rc *uwb_rc,
+		  const struct uwb_ie_hdr *ies, size_t size)
+{
+	int result = 0;
+	void *ptr;
+	const struct uwb_ie_hdr *ie;
+
+	mutex_lock(&uwb_rc->ies_mutex);
+
+	ptr = (void *)ies;
+	for (;;) {
+		ie = uwb_ie_next(&ptr, &size);
+		if (!ie)
+			break;
+
+		result = uwb_rc_ie_add_one(uwb_rc, ie);
+		if (result < 0)
+			break;
+	}
+	if (result >= 0) {
+		if (size == 0) {
+			if (uwb_rc->beaconing != -1)
+				result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
+		} else
+			result = -EINVAL;
+	}
+
+	mutex_unlock(&uwb_rc->ies_mutex);
+
+	return result;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_ie_add);
+
+
+/*
+ * Remove an IE from internal cache
+ *
+ * We are dealing with our internal IE cache so no need to verify that the
+ * IEs are valid (it has been done already).
+ *
+ * Should be called with ies_mutex held
+ *
+ * We do not break out once an IE is found in the cache. It is currently
+ * possible to have more than one IE with the same ID included in the
+ * beacon. We don't reallocate, we just mark the size smaller.
+ */
+static
+void uwb_rc_ie_cache_rm(struct uwb_rc *uwb_rc, enum uwb_ie to_remove)
+{
+	struct uwb_ie_hdr *ie;
+	size_t len = le16_to_cpu(uwb_rc->ies->wIELength);
+	void *ptr;
+	size_t size;
+
+	ptr = uwb_rc->ies->IEData;
+	size = len;
+	for (;;) {
+		ie = uwb_ie_next(&ptr, &size);
+		if (!ie)
+			break;
+		if (ie->element_id == to_remove) {
+			len -= sizeof(struct uwb_ie_hdr) + ie->length;
+			memmove(ie, ptr, size);
+			ptr = ie;
+		}
+	}
+	uwb_rc->ies->wIELength = cpu_to_le16(len);
+}
+
+
+/**
+ * uwb_rc_ie_rm - remove an IE from the radio controller's beacon
+ * @uwb_rc: the radio controller.
+ * @element_id: the element ID of the IE to remove.
+ *
+ * Only IEs previously added with uwb_rc_ie_add() may be removed.
+ *
+ * Returns 0 on success; or -ve the SET-IE command to the radio
+ * controller failed.
+ */
+int uwb_rc_ie_rm(struct uwb_rc *uwb_rc, enum uwb_ie element_id)
+{
+	int result = 0;
+
+	mutex_lock(&uwb_rc->ies_mutex);
+
+	uwb_rc_ie_cache_rm(uwb_rc, element_id);
+
+	if (uwb_rc->beaconing != -1)
+		result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
+
+	mutex_unlock(&uwb_rc->ies_mutex);
+
+	return result;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_ie_rm);