diff options
Diffstat (limited to 'kernel/drivers/uwb/beacon.c')
| -rw-r--r-- | kernel/drivers/uwb/beacon.c | 609 |
1 files changed, 609 insertions, 0 deletions
diff --git a/kernel/drivers/uwb/beacon.c b/kernel/drivers/uwb/beacon.c new file mode 100644 index 000000000..f40745fcb --- /dev/null +++ b/kernel/drivers/uwb/beacon.c @@ -0,0 +1,609 @@ +/* + * Ultra Wide Band + * Beacon management + * + * Copyright (C) 2005-2006 Intel Corporation + * Inaky Perez-Gonzalez <inaky.perez-gonzalez@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/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/kdev_t.h> +#include <linux/slab.h> + +#include "uwb-internal.h" + +/* Start Beaconing command structure */ +struct uwb_rc_cmd_start_beacon { + struct uwb_rccb rccb; + __le16 wBPSTOffset; + u8 bChannelNumber; +} __attribute__((packed)); + + +static int uwb_rc_start_beacon(struct uwb_rc *rc, u16 bpst_offset, u8 channel) +{ + int result; + struct uwb_rc_cmd_start_beacon *cmd; + struct uwb_rc_evt_confirm reply; + + cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); + if (cmd == NULL) + return -ENOMEM; + cmd->rccb.bCommandType = UWB_RC_CET_GENERAL; + cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_START_BEACON); + cmd->wBPSTOffset = cpu_to_le16(bpst_offset); + cmd->bChannelNumber = channel; + reply.rceb.bEventType = UWB_RC_CET_GENERAL; + reply.rceb.wEvent = UWB_RC_CMD_START_BEACON; + result = uwb_rc_cmd(rc, "START-BEACON", &cmd->rccb, sizeof(*cmd), + &reply.rceb, sizeof(reply)); + if (result < 0) + goto error_cmd; + if (reply.bResultCode != UWB_RC_RES_SUCCESS) { + dev_err(&rc->uwb_dev.dev, + "START-BEACON: command execution failed: %s (%d)\n", + uwb_rc_strerror(reply.bResultCode), reply.bResultCode); + result = -EIO; + } +error_cmd: + kfree(cmd); + return result; +} + +static int uwb_rc_stop_beacon(struct uwb_rc *rc) +{ + int result; + struct uwb_rccb *cmd; + struct uwb_rc_evt_confirm reply; + + 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_STOP_BEACON); + reply.rceb.bEventType = UWB_RC_CET_GENERAL; + reply.rceb.wEvent = UWB_RC_CMD_STOP_BEACON; + result = uwb_rc_cmd(rc, "STOP-BEACON", cmd, sizeof(*cmd), + &reply.rceb, sizeof(reply)); + if (result < 0) + goto error_cmd; + if (reply.bResultCode != UWB_RC_RES_SUCCESS) { + dev_err(&rc->uwb_dev.dev, + "STOP-BEACON: command execution failed: %s (%d)\n", + uwb_rc_strerror(reply.bResultCode), reply.bResultCode); + result = -EIO; + } +error_cmd: + kfree(cmd); + return result; +} + +/* + * Start/stop beacons + * + * @rc: UWB Radio Controller to operate on + * @channel: UWB channel on which to beacon (WUSB[table + * 5-12]). If -1, stop beaconing. + * @bpst_offset: Beacon Period Start Time offset; FIXME-do zero + * + * According to WHCI 0.95 [4.13.6] the driver will only receive the RCEB + * of a SET IE command after the device sent the first beacon that includes + * the IEs specified in the SET IE command. So, after we start beaconing we + * check if there is anything in the IE cache and call the SET IE command + * if needed. + */ +int uwb_rc_beacon(struct uwb_rc *rc, int channel, unsigned bpst_offset) +{ + int result; + struct device *dev = &rc->uwb_dev.dev; + + dev_dbg(dev, "%s: channel = %d\n", __func__, channel); + if (channel < 0) + channel = -1; + if (channel == -1) + result = uwb_rc_stop_beacon(rc); + else { + /* channel >= 0...dah */ + result = uwb_rc_start_beacon(rc, bpst_offset, channel); + if (result < 0) { + dev_err(dev, "Cannot start beaconing: %d\n", result); + return result; + } + if (le16_to_cpu(rc->ies->wIELength) > 0) { + result = uwb_rc_set_ie(rc, rc->ies); + if (result < 0) { + dev_err(dev, "Cannot set new IE on device: " + "%d\n", result); + result = uwb_rc_stop_beacon(rc); + channel = -1; + bpst_offset = 0; + } + } + } + + if (result >= 0) + rc->beaconing = channel; + return result; +} + +/* + * Beacon cache + * + * The purpose of this is to speed up the lookup of becon information + * when a new beacon arrives. The UWB Daemon uses it also to keep a + * tab of which devices are in radio distance and which not. When a + * device's beacon stays present for more than a certain amount of + * time, it is considered a new, usable device. When a beacon ceases + * to be received for a certain amount of time, it is considered that + * the device is gone. + * + * FIXME: use an allocator for the entries + * FIXME: use something faster for search than a list + */ + +void uwb_bce_kfree(struct kref *_bce) +{ + struct uwb_beca_e *bce = container_of(_bce, struct uwb_beca_e, refcnt); + + kfree(bce->be); + kfree(bce); +} + + +/* Find a beacon by dev addr in the cache */ +static +struct uwb_beca_e *__uwb_beca_find_bydev(struct uwb_rc *rc, + const struct uwb_dev_addr *dev_addr) +{ + struct uwb_beca_e *bce, *next; + list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) { + if (!memcmp(&bce->dev_addr, dev_addr, sizeof(bce->dev_addr))) + goto out; + } + bce = NULL; +out: + return bce; +} + +/* Find a beacon by dev addr in the cache */ +static +struct uwb_beca_e *__uwb_beca_find_bymac(struct uwb_rc *rc, + const struct uwb_mac_addr *mac_addr) +{ + struct uwb_beca_e *bce, *next; + list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) { + if (!memcmp(bce->mac_addr, mac_addr->data, + sizeof(struct uwb_mac_addr))) + goto out; + } + bce = NULL; +out: + return bce; +} + +/** + * uwb_dev_get_by_devaddr - get a UWB device with a specific DevAddr + * @rc: the radio controller that saw the device + * @devaddr: DevAddr of the UWB device to find + * + * There may be more than one matching device (in the case of a + * DevAddr conflict), but only the first one is returned. + */ +struct uwb_dev *uwb_dev_get_by_devaddr(struct uwb_rc *rc, + const struct uwb_dev_addr *devaddr) +{ + struct uwb_dev *found = NULL; + struct uwb_beca_e *bce; + + mutex_lock(&rc->uwb_beca.mutex); + bce = __uwb_beca_find_bydev(rc, devaddr); + if (bce) + found = uwb_dev_try_get(rc, bce->uwb_dev); + mutex_unlock(&rc->uwb_beca.mutex); + + return found; +} + +/** + * uwb_dev_get_by_macaddr - get a UWB device with a specific EUI-48 + * @rc: the radio controller that saw the device + * @devaddr: EUI-48 of the UWB device to find + */ +struct uwb_dev *uwb_dev_get_by_macaddr(struct uwb_rc *rc, + const struct uwb_mac_addr *macaddr) +{ + struct uwb_dev *found = NULL; + struct uwb_beca_e *bce; + + mutex_lock(&rc->uwb_beca.mutex); + bce = __uwb_beca_find_bymac(rc, macaddr); + if (bce) + found = uwb_dev_try_get(rc, bce->uwb_dev); + mutex_unlock(&rc->uwb_beca.mutex); + + return found; +} + +/* Initialize a beacon cache entry */ +static void uwb_beca_e_init(struct uwb_beca_e *bce) +{ + mutex_init(&bce->mutex); + kref_init(&bce->refcnt); + stats_init(&bce->lqe_stats); + stats_init(&bce->rssi_stats); +} + +/* + * Add a beacon to the cache + * + * @be: Beacon event information + * @bf: Beacon frame (part of b, really) + * @ts_jiffies: Timestamp (in jiffies) when the beacon was received + */ +static +struct uwb_beca_e *__uwb_beca_add(struct uwb_rc *rc, + struct uwb_rc_evt_beacon *be, + struct uwb_beacon_frame *bf, + unsigned long ts_jiffies) +{ + struct uwb_beca_e *bce; + + bce = kzalloc(sizeof(*bce), GFP_KERNEL); + if (bce == NULL) + return NULL; + uwb_beca_e_init(bce); + bce->ts_jiffies = ts_jiffies; + bce->uwb_dev = NULL; + list_add(&bce->node, &rc->uwb_beca.list); + return bce; +} + +/* + * Wipe out beacon entries that became stale + * + * Remove associated devicest too. + */ +void uwb_beca_purge(struct uwb_rc *rc) +{ + struct uwb_beca_e *bce, *next; + unsigned long expires; + + mutex_lock(&rc->uwb_beca.mutex); + list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) { + expires = bce->ts_jiffies + msecs_to_jiffies(beacon_timeout_ms); + if (time_after(jiffies, expires)) { + uwbd_dev_offair(bce); + } + } + mutex_unlock(&rc->uwb_beca.mutex); +} + +/* Clean up the whole beacon cache. Called on shutdown */ +void uwb_beca_release(struct uwb_rc *rc) +{ + struct uwb_beca_e *bce, *next; + + mutex_lock(&rc->uwb_beca.mutex); + list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) { + list_del(&bce->node); + uwb_bce_put(bce); + } + mutex_unlock(&rc->uwb_beca.mutex); +} + +static void uwb_beacon_print(struct uwb_rc *rc, struct uwb_rc_evt_beacon *be, + struct uwb_beacon_frame *bf) +{ + char macbuf[UWB_ADDR_STRSIZE]; + char devbuf[UWB_ADDR_STRSIZE]; + char dstbuf[UWB_ADDR_STRSIZE]; + + uwb_mac_addr_print(macbuf, sizeof(macbuf), &bf->Device_Identifier); + uwb_dev_addr_print(devbuf, sizeof(devbuf), &bf->hdr.SrcAddr); + uwb_dev_addr_print(dstbuf, sizeof(dstbuf), &bf->hdr.DestAddr); + dev_info(&rc->uwb_dev.dev, + "BEACON from %s to %s (ch%u offset %u slot %u MAC %s)\n", + devbuf, dstbuf, be->bChannelNumber, be->wBPSTOffset, + bf->Beacon_Slot_Number, macbuf); +} + +/* + * @bce: beacon cache entry, referenced + */ +ssize_t uwb_bce_print_IEs(struct uwb_dev *uwb_dev, struct uwb_beca_e *bce, + char *buf, size_t size) +{ + ssize_t result = 0; + struct uwb_rc_evt_beacon *be; + struct uwb_beacon_frame *bf; + int ies_len; + struct uwb_ie_hdr *ies; + + mutex_lock(&bce->mutex); + + be = bce->be; + if (be) { + bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo; + ies_len = be->wBeaconInfoLength - sizeof(struct uwb_beacon_frame); + ies = (struct uwb_ie_hdr *)bf->IEData; + + result = uwb_ie_dump_hex(ies, ies_len, buf, size); + } + + mutex_unlock(&bce->mutex); + + return result; +} + +/* + * Verify that the beacon event, frame and IEs are ok + */ +static int uwb_verify_beacon(struct uwb_rc *rc, struct uwb_event *evt, + struct uwb_rc_evt_beacon *be) +{ + int result = -EINVAL; + struct uwb_beacon_frame *bf; + struct device *dev = &rc->uwb_dev.dev; + + /* Is there enough data to decode a beacon frame? */ + if (evt->notif.size < sizeof(*be) + sizeof(*bf)) { + dev_err(dev, "BEACON event: Not enough data to decode " + "(%zu vs %zu bytes needed)\n", evt->notif.size, + sizeof(*be) + sizeof(*bf)); + goto error; + } + /* FIXME: make sure beacon frame IEs are fine and that the whole thing + * is consistent */ + result = 0; +error: + return result; +} + +/* + * Handle UWB_RC_EVT_BEACON events + * + * We check the beacon cache to see how the received beacon fares. If + * is there already we refresh the timestamp. If not we create a new + * entry. + * + * According to the WHCI and WUSB specs, only one beacon frame is + * allowed per notification block, so we don't bother about scanning + * for more. + */ +int uwbd_evt_handle_rc_beacon(struct uwb_event *evt) +{ + int result = -EINVAL; + struct uwb_rc *rc; + struct uwb_rc_evt_beacon *be; + struct uwb_beacon_frame *bf; + struct uwb_beca_e *bce; + + rc = evt->rc; + be = container_of(evt->notif.rceb, struct uwb_rc_evt_beacon, rceb); + result = uwb_verify_beacon(rc, evt, be); + if (result < 0) + return result; + + /* FIXME: handle alien beacons. */ + if (be->bBeaconType == UWB_RC_BEACON_TYPE_OL_ALIEN || + be->bBeaconType == UWB_RC_BEACON_TYPE_NOL_ALIEN) { + return -ENOSYS; + } + + bf = (struct uwb_beacon_frame *) be->BeaconInfo; + + /* + * Drop beacons from devices with a NULL EUI-48 -- they cannot + * be uniquely identified. + * + * It's expected that these will all be WUSB devices and they + * have a WUSB specific connection method so ignoring them + * here shouldn't be a problem. + */ + if (uwb_mac_addr_bcast(&bf->Device_Identifier)) + return 0; + + mutex_lock(&rc->uwb_beca.mutex); + bce = __uwb_beca_find_bymac(rc, &bf->Device_Identifier); + if (bce == NULL) { + /* Not in there, a new device is pinging */ + uwb_beacon_print(evt->rc, be, bf); + bce = __uwb_beca_add(rc, be, bf, evt->ts_jiffies); + if (bce == NULL) { + mutex_unlock(&rc->uwb_beca.mutex); + return -ENOMEM; + } + } + mutex_unlock(&rc->uwb_beca.mutex); + + mutex_lock(&bce->mutex); + /* purge old beacon data */ + kfree(bce->be); + + /* Update commonly used fields */ + bce->ts_jiffies = evt->ts_jiffies; + bce->be = be; + bce->dev_addr = bf->hdr.SrcAddr; + bce->mac_addr = &bf->Device_Identifier; + be->wBPSTOffset = le16_to_cpu(be->wBPSTOffset); + be->wBeaconInfoLength = le16_to_cpu(be->wBeaconInfoLength); + stats_add_sample(&bce->lqe_stats, be->bLQI - 7); + stats_add_sample(&bce->rssi_stats, be->bRSSI + 18); + + /* + * This might be a beacon from a new device. + */ + if (bce->uwb_dev == NULL) + uwbd_dev_onair(evt->rc, bce); + + mutex_unlock(&bce->mutex); + + return 1; /* we keep the event data */ +} + +/* + * Handle UWB_RC_EVT_BEACON_SIZE events + * + * XXXXX + */ +int uwbd_evt_handle_rc_beacon_size(struct uwb_event *evt) +{ + int result = -EINVAL; + struct device *dev = &evt->rc->uwb_dev.dev; + struct uwb_rc_evt_beacon_size *bs; + + /* Is there enough data to decode the event? */ + if (evt->notif.size < sizeof(*bs)) { + dev_err(dev, "BEACON SIZE notification: Not enough data to " + "decode (%zu vs %zu bytes needed)\n", + evt->notif.size, sizeof(*bs)); + goto error; + } + bs = container_of(evt->notif.rceb, struct uwb_rc_evt_beacon_size, rceb); + if (0) + dev_info(dev, "Beacon size changed to %u bytes " + "(FIXME: action?)\n", le16_to_cpu(bs->wNewBeaconSize)); + else { + /* temporary hack until we do something with this message... */ + static unsigned count; + if (++count % 1000 == 0) + dev_info(dev, "Beacon size changed %u times " + "(FIXME: action?)\n", count); + } + result = 0; +error: + return result; +} + +/** + * uwbd_evt_handle_rc_bp_slot_change - handle a BP_SLOT_CHANGE event + * @evt: the BP_SLOT_CHANGE notification from the radio controller + * + * If the event indicates that no beacon period slots were available + * then radio controller has transitioned to a non-beaconing state. + * Otherwise, simply save the current beacon slot. + */ +int uwbd_evt_handle_rc_bp_slot_change(struct uwb_event *evt) +{ + struct uwb_rc *rc = evt->rc; + struct device *dev = &rc->uwb_dev.dev; + struct uwb_rc_evt_bp_slot_change *bpsc; + + if (evt->notif.size < sizeof(*bpsc)) { + dev_err(dev, "BP SLOT CHANGE event: Not enough data\n"); + return -EINVAL; + } + bpsc = container_of(evt->notif.rceb, struct uwb_rc_evt_bp_slot_change, rceb); + + if (uwb_rc_evt_bp_slot_change_no_slot(bpsc)) { + dev_err(dev, "stopped beaconing: No free slots in BP\n"); + mutex_lock(&rc->uwb_dev.mutex); + rc->beaconing = -1; + mutex_unlock(&rc->uwb_dev.mutex); + } else + rc->uwb_dev.beacon_slot = uwb_rc_evt_bp_slot_change_slot_num(bpsc); + + return 0; +} + +/** + * Handle UWB_RC_EVT_BPOIE_CHANGE events + * + * XXXXX + */ +struct uwb_ie_bpo { + struct uwb_ie_hdr hdr; + u8 bp_length; + u8 data[]; +} __attribute__((packed)); + +int uwbd_evt_handle_rc_bpoie_change(struct uwb_event *evt) +{ + int result = -EINVAL; + struct device *dev = &evt->rc->uwb_dev.dev; + struct uwb_rc_evt_bpoie_change *bpoiec; + struct uwb_ie_bpo *bpoie; + static unsigned count; /* FIXME: this is a temp hack */ + size_t iesize; + + /* Is there enough data to decode it? */ + if (evt->notif.size < sizeof(*bpoiec)) { + dev_err(dev, "BPOIEC notification: Not enough data to " + "decode (%zu vs %zu bytes needed)\n", + evt->notif.size, sizeof(*bpoiec)); + goto error; + } + bpoiec = container_of(evt->notif.rceb, struct uwb_rc_evt_bpoie_change, rceb); + iesize = le16_to_cpu(bpoiec->wBPOIELength); + if (iesize < sizeof(*bpoie)) { + dev_err(dev, "BPOIEC notification: Not enough IE data to " + "decode (%zu vs %zu bytes needed)\n", + iesize, sizeof(*bpoie)); + goto error; + } + if (++count % 1000 == 0) /* Lame placeholder */ + dev_info(dev, "BPOIE: %u changes received\n", count); + /* + * FIXME: At this point we should go over all the IEs in the + * bpoiec->BPOIE array and act on each. + */ + result = 0; +error: + return result; +} + +/* + * Print beaconing state. + */ +static ssize_t uwb_rc_beacon_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct uwb_dev *uwb_dev = to_uwb_dev(dev); + struct uwb_rc *rc = uwb_dev->rc; + ssize_t result; + + mutex_lock(&rc->uwb_dev.mutex); + result = sprintf(buf, "%d\n", rc->beaconing); + mutex_unlock(&rc->uwb_dev.mutex); + return result; +} + +/* + * Start beaconing on the specified channel, or stop beaconing. + */ +static ssize_t uwb_rc_beacon_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct uwb_dev *uwb_dev = to_uwb_dev(dev); + struct uwb_rc *rc = uwb_dev->rc; + int channel; + ssize_t result = -EINVAL; + + result = sscanf(buf, "%d", &channel); + if (result >= 1) + result = uwb_radio_force_channel(rc, channel); + + return result < 0 ? result : size; +} +DEVICE_ATTR(beacon, S_IRUGO | S_IWUSR, uwb_rc_beacon_show, uwb_rc_beacon_store); |