/* * 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 "uwb-internal.h" #define D_LOCAL 0 #include <linux/uwb/debug.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; mutex_lock(&rc->uwb_dev.mutex); 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) goto out_up; 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; } else result = 0; } } if (result < 0) goto out_up; rc->beaconing = channel; uwb_notify(rc, NULL, uwb_bg_joined(rc) ? UWB_NOTIF_BG_JOIN : UWB_NOTIF_BG_LEAVE); out_up: mutex_unlock(&rc->uwb_dev.mutex); 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 */ struct uwb_beca uwb_beca = { .list = LIST_HEAD_INIT(uwb_beca.list), .mutex = __MUTEX_INITIALIZER(uwb_beca.mutex) }; 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(const struct uwb_dev_addr *dev_addr) { struct uwb_beca_e *bce, *next; list_for_each_entry_safe(bce, next, &uwb_beca.list, node) { d_printf(6, NULL, "looking for addr %02x:%02x in %02x:%02x\n", dev_addr->data[0], dev_addr->data[1], bce->dev_addr.data[0], bce->dev_addr.data[1]); 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(const struct uwb_mac_addr *mac_addr) { struct uwb_beca_e *bce, *next; list_for_each_entry_safe(bce, next, &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(&uwb_beca.mutex); bce = __uwb_beca_find_bydev(devaddr); if (bce) found = uwb_dev_try_get(rc, bce->uwb_dev); mutex_unlock(&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(&uwb_beca.mutex); bce = __uwb_beca_find_bymac(macaddr); if (bce) found = uwb_dev_try_get(rc, bce->uwb_dev); mutex_unlock(&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 */ struct uwb_beca_e *__uwb_beca_add(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, &uwb_beca.list); return bce; } /* * Wipe out beacon entries that became stale * * Remove associated devicest too. */ void uwb_beca_purge(void) { struct uwb_beca_e *bce, *next; unsigned long expires; mutex_lock(&uwb_beca.mutex); list_for_each_entry_safe(bce, next, &uwb_beca.list, node) { expires = bce->ts_jiffies + msecs_to_jiffies(beacon_timeout_ms); if (time_after(jiffies, expires)) { uwbd_dev_offair(bce); list_del(&bce->node); uwb_bce_put(bce); } } mutex_unlock(&uwb_beca.mutex); } /* Clean up the whole beacon cache. Called on shutdown */ void uwb_beca_release(void) { struct uwb_beca_e *bce, *next; mutex_lock(&uwb_beca.mutex); list_for_each_entry_safe(bce, next, &uwb_beca.list, node) { list_del(&bce->node); uwb_bce_put(bce); } mutex_unlock(&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; struct uwb_buf_ctx ctx = { .buf = buf, .bytes = 0, .size = size }; mutex_lock(&bce->mutex); be = bce->be; if (be == NULL) goto out; bf = (void *) be->BeaconInfo; uwb_ie_for_each(uwb_dev, uwb_ie_dump_hex, &ctx, bf->IEData, be->wBeaconInfoLength - sizeof(*bf)); result = ctx.bytes; out: 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; unsigned long last_ts; 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(&uwb_beca.mutex); bce = __uwb_beca_find_bymac(&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(be, bf, evt->ts_jiffies); if (bce == NULL) { mutex_unlock(&uwb_beca.mutex); return -ENOMEM; } } mutex_unlock(&uwb_beca.mutex); mutex_lock(&bce->mutex); /* purge old beacon data */ kfree(bce->be); last_ts = bce->ts_jiffies; /* 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); mutex_lock(&rc->uwb_dev.mutex); if (uwb_rc_evt_bp_slot_change_no_slot(bpsc)) { dev_info(dev, "stopped beaconing: No free slots in BP\n"); rc->beaconing = -1; } else rc->uwb_dev.beacon_slot = uwb_rc_evt_bp_slot_change_slot_num(bpsc); mutex_unlock(&rc->uwb_dev.mutex); 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; } /** * uwb_bg_joined - is the RC in a beacon group? * @rc: the radio controller * * Returns true if the radio controller is in a beacon group (even if * it's the sole member). */ int uwb_bg_joined(struct uwb_rc *rc) { return rc->beaconing != -1; } EXPORT_SYMBOL_GPL(uwb_bg_joined); /* * 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. * * The BPST offset of when to start searching for a beacon group to * join may be specified. */ 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; unsigned bpst_offset = 0; ssize_t result = -EINVAL; result = sscanf(buf, "%d %u\n", &channel, &bpst_offset); if (result >= 1) result = uwb_rc_beacon(rc, channel, bpst_offset); return result < 0 ? result : size; } DEVICE_ATTR(beacon, S_IRUGO | S_IWUSR, uwb_rc_beacon_show, uwb_rc_beacon_store);