uwb: add the UWB stack (MLME)

Most of the MAC Layer Management Entity (MLME) support: address, beacon, IE
and scan management.

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

1 files changed, 570 insertions, 0 deletions

diff --git a/drivers/uwb/ie.c b/drivers/uwb/ie.c
new file mode 100644
index 000000000000..d54fe09a986d
--- /dev/null
+++ b/drivers/uwb/ie.c
@@ -0,0 +1,570 @@
+/*
+ * 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>
+ *
+ * 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 "uwb-internal.h"
+#define D_LOCAL 0
+#include <linux/uwb/debug.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);
+
+/**
+ * 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.
+ */
+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;
+
+        d_fnstart(3, dev, "(%p, %p)\n", uwb_rc, pget_ie);
+        result = -ENOMEM;
+        cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+        if (cmd == NULL)
+                goto error_kzalloc;
+        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);
+        if (result < 0)
+                goto error_cmd;
+        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));
+                result = -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));
+                result = -EINVAL;
+        } else
+                *pget_ie = get_ie;
+error_cmd:
+        kfree(cmd);
+error_kzalloc:
+        d_fnend(3, dev, "(%p, %p) = %d\n", uwb_rc, pget_ie, (int)result);
+        return result;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_get_ie);
+
+
+/*
+ * Given a pointer to an IE, print it in ASCII/hex followed by a new line
+ *
+ * @ie_hdr: pointer to the IE header. Length is in there, and it is
+ *          guaranteed that the ie_hdr->length bytes following it are
+ *          safely accesible.
+ *
+ * @_data: context data passed from uwb_ie_for_each(), an struct output_ctx
+ */
+int uwb_ie_dump_hex(struct uwb_dev *uwb_dev, const struct uwb_ie_hdr *ie_hdr,
+                    size_t offset, void *_ctx)
+{
+        struct uwb_buf_ctx *ctx = _ctx;
+        const u8 *pl = (void *)(ie_hdr + 1);
+        u8 pl_itr;
+
+        ctx->bytes += scnprintf(ctx->buf + ctx->bytes, ctx->size - ctx->bytes,
+                                "%02x %02x ", (unsigned) ie_hdr->element_id,
+                                (unsigned) ie_hdr->length);
+        pl_itr = 0;
+        while (pl_itr < ie_hdr->length && ctx->bytes < ctx->size)
+                ctx->bytes += scnprintf(ctx->buf + ctx->bytes,
+                                        ctx->size - ctx->bytes,
+                                        "%02x ", (unsigned) pl[pl_itr++]);
+        if (ctx->bytes < ctx->size)
+                ctx->buf[ctx->bytes++] = '\n';
+        return 0;
+}
+EXPORT_SYMBOL_GPL(uwb_ie_dump_hex);
+
+
+/**
+ * Verify that a pointer in a buffer points to valid IE
+ *
+ * @start: pointer to start of buffer in which IE appears
+ * @itr:   pointer to IE inside buffer that will be verified
+ * @top:   pointer to end of buffer
+ *
+ * @returns: 0 if IE is valid, <0 otherwise
+ *
+ * Verification involves checking that the buffer can contain a
+ * header and the amount of data reported in the IE header can be found in
+ * the buffer.
+ */
+static
+int uwb_rc_ie_verify(struct uwb_dev *uwb_dev, const void *start,
+                     const void *itr, const void *top)
+{
+        struct device *dev = &uwb_dev->dev;
+        const struct uwb_ie_hdr *ie_hdr;
+
+        if (top - itr < sizeof(*ie_hdr)) {
+                dev_err(dev, "Bad IE: no data to decode header "
+                        "(%zu bytes left vs %zu needed) at offset %zu\n",
+                        top - itr, sizeof(*ie_hdr), itr - start);
+                return -EINVAL;
+        }
+        ie_hdr = itr;
+        itr += sizeof(*ie_hdr);
+        if (top - itr < ie_hdr->length) {
+                dev_err(dev, "Bad IE: not enough data for payload "
+                        "(%zu bytes left vs %zu needed) at offset %zu\n",
+                        top - itr, (size_t)ie_hdr->length,
+                        (void *)ie_hdr - start);
+                return -EINVAL;
+        }
+        return 0;
+}
+
+
+/**
+ * Walk a buffer filled with consecutive IE's a buffer
+ *
+ * @uwb_dev: UWB device this IEs belong to (for err messages mainly)
+ *
+ * @fn: function to call with each IE; if it returns 0, we keep
+ *      traversing the buffer. If it returns !0, we'll stop and return
+ *      that value.
+ *
+ * @data: pointer passed to @fn
+ *
+ * @buf: buffer where the consecutive IEs are located
+ *
+ * @size: size of @buf
+ *
+ * Each IE is checked for basic correctness (there is space left for
+ * the header and the payload). If that test is failed, we stop
+ * processing. For every good IE, @fn is called.
+ */
+ssize_t uwb_ie_for_each(struct uwb_dev *uwb_dev, uwb_ie_f fn, void *data,
+                        const void *buf, size_t size)
+{
+        ssize_t result = 0;
+        const struct uwb_ie_hdr *ie_hdr;
+        const void *itr = buf, *top = itr + size;
+
+        while (itr < top) {
+                if (uwb_rc_ie_verify(uwb_dev, buf, itr, top) != 0)
+                        break;
+                ie_hdr = itr;
+                itr += sizeof(*ie_hdr) + ie_hdr->length;
+                result = fn(uwb_dev, ie_hdr, itr - buf, data);
+                if (result != 0)
+                        break;
+        }
+        return result;
+}
+EXPORT_SYMBOL_GPL(uwb_ie_for_each);
+
+
+/**
+ * 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;
+}
+
+/**
+ * Determine by IE id if IE is host settable
+ * WUSB 1.0 [8.6.2.8 Table 8.85]
+ *
+ * EXCEPTION:
+ * All but UWB_IE_WLP appears in Table 8.85 from WUSB 1.0. Setting this IE
+ * is required for the WLP substack to perform association with its WSS so
+ * we hope that the WUSB spec will be changed to reflect this.
+ */
+static
+int uwb_rc_ie_is_host_settable(enum uwb_ie element_id)
+{
+        if (element_id == UWB_PCA_AVAILABILITY ||
+            element_id == UWB_BP_SWITCH_IE ||
+            element_id == UWB_MAC_CAPABILITIES_IE ||
+            element_id == UWB_PHY_CAPABILITIES_IE ||
+            element_id == UWB_APP_SPEC_PROBE_IE ||
+            element_id == UWB_IDENTIFICATION_IE ||
+            element_id == UWB_MASTER_KEY_ID_IE ||
+            element_id == UWB_IE_WLP ||
+            element_id == UWB_APP_SPEC_IE)
+                return 1;
+        return 0;
+}
+
+
+/**
+ * Extract Host Settable IEs from IE
+ *
+ * @ie_data: pointer to buffer containing all IEs
+ * @size:    size of buffer
+ *
+ * @returns: length of buffer that only includes host settable IEs
+ *
+ * Given a buffer of IEs we move all Host Settable IEs to front of buffer
+ * by overwriting the IEs that are not Host Settable.
+ * Buffer length is adjusted accordingly.
+ */
+static
+ssize_t uwb_rc_parse_host_settable_ie(struct uwb_dev *uwb_dev,
+                                      void *ie_data, size_t size)
+{
+        size_t new_len = size;
+        struct uwb_ie_hdr *ie_hdr;
+        size_t ie_length;
+        void *itr = ie_data, *top = itr + size;
+
+        while (itr < top) {
+                if (uwb_rc_ie_verify(uwb_dev, ie_data, itr, top) != 0)
+                        break;
+                ie_hdr = itr;
+                ie_length = sizeof(*ie_hdr) + ie_hdr->length;
+                if (uwb_rc_ie_is_host_settable(ie_hdr->element_id)) {
+                        itr += ie_length;
+                } else {
+                        memmove(itr, itr + ie_length, top - (itr + ie_length));
+                        new_len -= ie_length;
+                        top -= ie_length;
+                }
+        }
+        return new_len;
+}
+
+
+/* Cleanup the whole IE management subsystem */
+void uwb_rc_ie_init(struct uwb_rc *uwb_rc)
+{
+        mutex_init(&uwb_rc->ies_mutex);
+}
+
+
+/**
+ * Set up cache for host settable IEs currently being transmitted
+ *
+ * First we just call GET-IE to get the current IEs being transmitted
+ * (or we workaround and pretend we did) and (because the format is
+ * the same) reuse that as the IE cache (with the command prefix, as
+ * explained in 'struct uwb_rc').
+ *
+ * @returns: size of cache created
+ */
+ssize_t uwb_rc_ie_setup(struct uwb_rc *uwb_rc)
+{
+        struct device *dev = &uwb_rc->uwb_dev.dev;
+        ssize_t result;
+        size_t capacity;
+        struct uwb_rc_evt_get_ie *ie_info;
+
+        d_fnstart(3, dev, "(%p)\n", uwb_rc);
+        mutex_lock(&uwb_rc->ies_mutex);
+        result = uwb_rc_get_ie(uwb_rc, &ie_info);
+        if (result < 0)
+                goto error_get_ie;
+        capacity = result;
+        d_printf(5, dev, "Got IEs %zu bytes (%zu long at %p)\n", result,
+                 (size_t)le16_to_cpu(ie_info->wIELength), ie_info);
+
+        /* Remove IEs that host should not set. */
+        result = uwb_rc_parse_host_settable_ie(&uwb_rc->uwb_dev,
+                        ie_info->IEData, le16_to_cpu(ie_info->wIELength));
+        if (result < 0)
+                goto error_parse;
+        d_printf(5, dev, "purged non-settable IEs to %zu bytes\n", result);
+        uwb_rc->ies = (void *) 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;
+        d_printf(5, dev, "IE cache at %p %zu bytes, %zu capacity\n",
+                 ie_info, result, capacity);
+        result = 0;
+error_parse:
+error_get_ie:
+        mutex_unlock(&uwb_rc->ies_mutex);
+        d_fnend(3, dev, "(%p) = %zu\n", uwb_rc, result);
+        return result;
+}
+
+
+/* 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 __acc_size(struct uwb_dev *uwb_dev, const struct uwb_ie_hdr *ie_hdr,
+               size_t offset, void *_ctx)
+{
+        size_t *acc_size = _ctx;
+        *acc_size += sizeof(*ie_hdr) + ie_hdr->length;
+        d_printf(6, &uwb_dev->dev, "new acc size %zu\n", *acc_size);
+        return 0;
+}
+
+
+/**
+ * Add a new IE to IEs currently being transmitted by device
+ *
+ * @ies: the buffer containing the new IE or IEs to be added to
+ *       the device's beacon. The buffer will be verified for
+ *       consistence (meaning the headers should be right) and
+ *       consistent with the buffer size.
+ * @size: size of @ies (in bytes, total buffer size)
+ * @returns: 0 if ok, <0 errno code on error
+ *
+ * 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, append the
+ * new one, and call SET IE with all the IEs needed.
+ *
+ * The local IE cache will only be updated with the new IE if SET IE
+ * completed successfully.
+ */
+int uwb_rc_ie_add(struct uwb_rc *uwb_rc,
+                  const struct uwb_ie_hdr *ies, size_t size)
+{
+        int result = 0;
+        struct device *dev = &uwb_rc->uwb_dev.dev;
+        struct uwb_rc_cmd_set_ie *new_ies;
+        size_t ies_size, total_size, acc_size = 0;
+
+        if (uwb_rc->ies == NULL)
+                return -ESHUTDOWN;
+        uwb_ie_for_each(&uwb_rc->uwb_dev, __acc_size, &acc_size, ies, size);
+        if (acc_size != size) {
+                dev_err(dev, "BUG: bad IEs, misconstructed headers "
+                        "[%zu bytes reported vs %zu calculated]\n",
+                        size, acc_size);
+                WARN_ON(1);
+                return -EINVAL;
+        }
+        mutex_lock(&uwb_rc->ies_mutex);
+        ies_size = le16_to_cpu(uwb_rc->ies->wIELength);
+        total_size = sizeof(*uwb_rc->ies) + ies_size;
+        if (total_size + size > uwb_rc->ies_capacity) {
+                d_printf(4, dev, "Reallocating IE cache from %p capacity %zu "
+                         "to capacity %zu\n", uwb_rc->ies, uwb_rc->ies_capacity,
+                         total_size + size);
+                new_ies = kzalloc(total_size + size, GFP_KERNEL);
+                if (new_ies == NULL) {
+                        dev_err(dev, "No memory for adding new IE\n");
+                        result = -ENOMEM;
+                        goto error_alloc;
+                }
+                memcpy(new_ies, uwb_rc->ies, total_size);
+                uwb_rc->ies_capacity = total_size + size;
+                kfree(uwb_rc->ies);
+                uwb_rc->ies = new_ies;
+                d_printf(4, dev, "New IE cache at %p capacity %zu\n",
+                         uwb_rc->ies, uwb_rc->ies_capacity);
+        }
+        memcpy((void *)uwb_rc->ies + total_size, ies, size);
+        uwb_rc->ies->wIELength = cpu_to_le16(ies_size + size);
+        if (uwb_rc->beaconing != -1) {
+                result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
+                if (result < 0) {
+                        dev_err(dev, "Cannot set new IE on device: %d\n",
+                                result);
+                        uwb_rc->ies->wIELength = cpu_to_le16(ies_size);
+                } else
+                        result = 0;
+        }
+        d_printf(4, dev, "IEs now occupy %hu bytes of %zu capacity at %p\n",
+                 le16_to_cpu(uwb_rc->ies->wIELength), uwb_rc->ies_capacity,
+                 uwb_rc->ies);
+error_alloc:
+        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
+int uwb_rc_ie_cache_rm(struct uwb_rc *uwb_rc, enum uwb_ie to_remove)
+{
+        struct uwb_ie_hdr *ie_hdr;
+        size_t new_len = le16_to_cpu(uwb_rc->ies->wIELength);
+        void *itr = uwb_rc->ies->IEData;
+        void *top = itr + new_len;
+
+        while (itr < top) {
+                ie_hdr = itr;
+                if (ie_hdr->element_id != to_remove) {
+                        itr += sizeof(*ie_hdr) + ie_hdr->length;
+                } else {
+                        int ie_length;
+                        ie_length = sizeof(*ie_hdr) + ie_hdr->length;
+                        if (top - itr != ie_length)
+                                memmove(itr, itr + ie_length, top - itr + ie_length);
+                        top -= ie_length;
+                        new_len -= ie_length;
+                }
+        }
+        uwb_rc->ies->wIELength = cpu_to_le16(new_len);
+        return 0;
+}
+
+
+/**
+ * Remove an IE currently being transmitted by device
+ *
+ * @element_id: id of IE to be removed from device's beacon
+ */
+int uwb_rc_ie_rm(struct uwb_rc *uwb_rc, enum uwb_ie element_id)
+{
+        struct device *dev = &uwb_rc->uwb_dev.dev;
+        int result;
+
+        if (uwb_rc->ies == NULL)
+                return -ESHUTDOWN;
+        mutex_lock(&uwb_rc->ies_mutex);
+        result = uwb_rc_ie_cache_rm(uwb_rc, element_id);
+        if (result < 0)
+                dev_err(dev, "Cannot remove IE from cache.\n");
+        if (uwb_rc->beaconing != -1) {
+                result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
+                if (result < 0)
+                        dev_err(dev, "Cannot set new IE on device.\n");
+        }
+        mutex_unlock(&uwb_rc->ies_mutex);
+        return result;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_ie_rm);
+
+
+/**
+ * Create and set new Identification IE
+ *
+ * Currently only sets the Vendor ID. The Vendor ID is set from the OUI,
+ * which is obtained from the first three bytes from the MAC address.
+ */
+int uwb_rc_set_identification_ie(struct uwb_rc *uwb_rc)
+{
+        struct {
+                struct uwb_identification_ie id_ie;
+                struct uwb_dev_info dev_info;
+                struct uwb_vendor_id vendor_id;
+        } ie_data;
+
+        ie_data.id_ie.hdr.element_id = UWB_IDENTIFICATION_IE;
+        ie_data.id_ie.hdr.length = sizeof(struct uwb_dev_info) +
+                                   sizeof(struct uwb_vendor_id);
+
+        ie_data.dev_info.type = UWB_DEV_INFO_VENDOR_ID;
+        ie_data.dev_info.length = sizeof(struct uwb_vendor_id);
+
+        ie_data.vendor_id.data[0] = uwb_rc->uwb_dev.mac_addr.data[0];
+        ie_data.vendor_id.data[1] = uwb_rc->uwb_dev.mac_addr.data[1];
+        ie_data.vendor_id.data[2] = uwb_rc->uwb_dev.mac_addr.data[2];
+
+        return uwb_rc_ie_add(uwb_rc, &ie_data.id_ie.hdr, sizeof(ie_data));
+}