--- Makefile.am | 1 + src/offchannel.c | 338 +++++++++++++++++++++++++++++++++++++++++++++++ src/offchannel.h | 29 ++++ 3 files changed, 368 insertions(+) create mode 100644 src/offchannel.c create mode 100644 src/offchannel.h diff --git a/Makefile.am b/Makefile.am index 275dd1b9..5c5db879 100644 --- a/Makefile.am +++ b/Makefile.am @@ -247,6 +247,7 @@ src_iwd_SOURCES = src/main.c linux/nl80211.h src/iwd.h src/missing.h \ src/ip-pool.h src/ip-pool.c \ src/band.h src/band.c \ src/sysfs.h src/sysfs.c \ + src/offchannel.h src/offchannel.c \ $(eap_sources) \ $(builtin_sources) diff --git a/src/offchannel.c b/src/offchannel.c new file mode 100644 index 00000000..0ec067cd --- /dev/null +++ b/src/offchannel.c @@ -0,0 +1,338 @@ +/* + * + * Wireless daemon for Linux + * + * Copyright (C) 2021 Intel Corporation. All rights reserved. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <errno.h> + +#include <ell/ell.h> + +#include "linux/nl80211.h" + +#include "src/offchannel.h" +#include "src/wiphy.h" +#include "src/nl80211util.h" +#include "src/iwd.h" +#include "src/module.h" + +struct offchannel_info { + uint64_t wdev_id; + uint32_t freq; + uint32_t duration; + + uint32_t roc_cmd_id; + uint64_t roc_cookie; + + offchannel_started_cb_t started; + offchannel_destroy_cb_t destroy; + void *user_data; + struct l_timeout *timeout; + int error; + + struct wiphy_radio_work_item work; + + bool roc_started : 1; +}; + +static struct l_genl_family *nl80211; +static struct l_queue *offchannel_list; + +static bool match_wdev(const void *a, const void *user_data) +{ + const struct offchannel_info *info = a; + const uint64_t *wdev_id = user_data; + + return info->wdev_id == *wdev_id; +} + +static struct offchannel_info *find_offchannel(uint64_t wdev_id) +{ + return l_queue_find(offchannel_list, match_wdev, &wdev_id); +} + +static void offchannel_free(void *user_data) +{ + struct offchannel_info *info = user_data; + + if (info->timeout) + l_timeout_remove(info->timeout); + + l_free(info); +} + +static void offchannel_destroy(void *user_data) +{ + struct offchannel_info *info = user_data; + + if (info->destroy) + info->destroy(info->error, info->user_data); + + l_queue_remove(offchannel_list, info); + + offchannel_free(info); +} + +static void offchannel_roc_cb(struct l_genl_msg *msg, void *user_data) +{ + struct offchannel_info *info = user_data; + + info->error = l_genl_msg_get_error(msg); + info->roc_cmd_id = 0; + + if (info->error < 0) { + l_debug("Error from CMD_REMAIN_ON_CHANNEL (%d)", info->error); + goto error; + } + + info->error = nl80211_parse_attrs(msg, NL80211_ATTR_COOKIE, + &info->roc_cookie, NL80211_ATTR_UNSPEC); + if (info->error < 0) { + l_error("Could not parse ROC cookie"); + goto error; + } + + return; + +error: + offchannel_cancel(info->wdev_id, info->work.id); +} + +static void offchannel_timeout(struct l_timeout *timeout, void *user_data) +{ + struct offchannel_info *info = user_data; + + info->error = -EBUSY; + + offchannel_cancel(info->wdev_id, info->work.id); +} + +static bool offchannel_work_ready(struct wiphy_radio_work_item *item) +{ + struct l_genl_msg *msg; + struct offchannel_info *info = l_container_of(item, + struct offchannel_info, work); + + msg = l_genl_msg_new(NL80211_CMD_REMAIN_ON_CHANNEL); + + l_genl_msg_append_attr(msg, NL80211_ATTR_WDEV, 8, &info->wdev_id); + l_genl_msg_append_attr(msg, NL80211_ATTR_WIPHY_FREQ, 4, &info->freq); + l_genl_msg_append_attr(msg, NL80211_ATTR_DURATION, 4, &info->duration); + + info->roc_cmd_id = l_genl_family_send(nl80211, msg, offchannel_roc_cb, + info, NULL); + if (!info->roc_cmd_id) { + info->error = -EIO; + l_genl_msg_unref(msg); + return true; + } + + /* + * Don't rely on kernel timers for cleanup. This timeout is modified + * when the ROC is started and will time the actual duration at that + * point. If this timer expires prior to ROC starting the caller will + * be notified with -EBUSY in the destroy callback. In addition the + * offchannel_info is tracked in a queue only at this point so the + * queue will only have one outstanding item per wdev. + */ + info->timeout = l_timeout_create_ms(info->duration, offchannel_timeout, + info, NULL); + l_queue_push_head(offchannel_list, info); + + return false; +} + +static void offchannel_cancel_roc(struct offchannel_info *info) +{ + struct l_genl_msg *msg; + + msg = l_genl_msg_new(NL80211_CMD_CANCEL_REMAIN_ON_CHANNEL); + + l_genl_msg_append_attr(msg, NL80211_ATTR_WDEV, 8, &info->wdev_id); + l_genl_msg_append_attr(msg, NL80211_ATTR_COOKIE, 8, &info->roc_cookie); + + /* Nothing much can be done if this fails */ + if (!l_genl_family_send(nl80211, msg, NULL, NULL, NULL)) + l_genl_msg_unref(msg); +} + +static void offchannel_work_destroy(struct wiphy_radio_work_item *item) +{ + struct offchannel_info *info = l_container_of(item, + struct offchannel_info, work); + + /* + * Cancelled even before the kernel replied to the command. This + * could happen due to an IO error, parsing error, or if a very short + * duration is used. But if so there is no need to cancel ROC since the + * driver never went off channel in the first place. + */ + if (info->roc_cmd_id) { + info->error = -ECANCELED; + l_genl_family_cancel(nl80211, info->roc_cmd_id); + goto destroy; + } + + /* + * If info->roc_cmd_id is zero but we still have no cookie, something + * happened in offchannel_roc_cb. Basically, the command failed. The ROC + * does not need to be cancelled and destroy can be called immediately. + * An appropriate error will have been set by offchannel_roc_cb. + */ + if (!info->roc_cookie) + goto destroy; + + /* + * Cancelled prior to ROC completing, cancel ROC, and set -ECANCELLED + */ + if (info->roc_started && info->timeout) { + offchannel_cancel_roc(info); + + l_timeout_remove(info->timeout); + info->timeout = NULL; + + info->error = -ECANCELED; + } + + /* Otherwise the ROC finished normally */ + +destroy: + offchannel_destroy(info); +} + +static const struct wiphy_radio_work_item_ops offchannel_work_ops = { + .do_work = offchannel_work_ready, + .destroy = offchannel_work_destroy, +}; + +uint32_t offchannel_start(uint64_t wdev_id, uint32_t freq, uint32_t duration, + offchannel_started_cb_t started, void *user_data, + offchannel_destroy_cb_t destroy) +{ + struct offchannel_info *info = l_new(struct offchannel_info, 1); + + info->wdev_id = wdev_id; + info->freq = freq; + info->duration = duration; + info->started = started; + info->destroy = destroy; + info->user_data = user_data; + + return wiphy_radio_work_insert(wiphy_find_by_wdev(wdev_id), + &info->work, 1, &offchannel_work_ops); +} + +void offchannel_cancel(uint64_t wdev_id, uint32_t id) +{ + wiphy_radio_work_done(wiphy_find_by_wdev(wdev_id), id); +} + +static void offchannel_mlme_notify(struct l_genl_msg *msg, void *user_data) +{ + struct offchannel_info *info; + uint64_t wdev_id; + uint64_t cookie; + uint8_t cmd; + + cmd = l_genl_msg_get_command(msg); + + if (cmd != NL80211_CMD_REMAIN_ON_CHANNEL && + cmd != NL80211_CMD_CANCEL_REMAIN_ON_CHANNEL) + return; + + if (nl80211_parse_attrs(msg, NL80211_ATTR_WDEV, &wdev_id, + NL80211_ATTR_COOKIE, &cookie, + NL80211_ATTR_UNSPEC) < 0) + return; + + info = find_offchannel(wdev_id); + if (!info) + return; + + /* ROC must have been started elsewhere, not by IWD */ + if (info->roc_cookie != cookie) + return; + + switch (cmd) { + case NL80211_CMD_REMAIN_ON_CHANNEL: + l_timeout_modify_ms(info->timeout, info->duration); + + info->roc_started = true; + + if (info->started) + info->started(info->user_data); + + break; + case NL80211_CMD_CANCEL_REMAIN_ON_CHANNEL: + /* No matching ROC call? This shouldn't happen... */ + if (L_WARN_ON(!info->roc_started)) + return; + + l_timeout_remove(info->timeout); + info->timeout = NULL; + + info->error = 0; + offchannel_cancel(info->wdev_id, info->work.id); + + break; + default: + return; + } +} + +static int offchannel_init(void) +{ + struct l_genl *genl = iwd_get_genl(); + + nl80211 = l_genl_family_new(genl, NL80211_GENL_NAME); + if (!nl80211) { + l_error("Failed to obtain nl80211"); + return -EIO; + } + + if (!l_genl_family_register(nl80211, "mlme", offchannel_mlme_notify, + NULL, NULL)) { + l_error("Failed to register for MLME"); + l_genl_family_free(nl80211); + nl80211 = NULL; + + return -EIO; + } + + offchannel_list = l_queue_new(); + + return 0; +} + +static void offchannel_exit(void) +{ + l_debug(""); + + l_genl_family_free(nl80211); + nl80211 = NULL; + + l_queue_destroy(offchannel_list, offchannel_free); +} + +IWD_MODULE(offchannel, offchannel_init, offchannel_exit); +IWD_MODULE_DEPENDS(offchannel, wiphy); diff --git a/src/offchannel.h b/src/offchannel.h new file mode 100644 index 00000000..1ffa94f1 --- /dev/null +++ b/src/offchannel.h @@ -0,0 +1,29 @@ +/* + * + * Wireless daemon for Linux + * + * Copyright (C) 2021 Intel Corporation. All rights reserved. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +typedef void (*offchannel_started_cb_t)(void *user_data); +typedef void (*offchannel_destroy_cb_t)(int error, void *user_data); + +uint32_t offchannel_start(uint64_t wdev_id, uint32_t freq, uint32_t duration, + offchannel_started_cb_t started, void *user_data, + offchannel_destroy_cb_t destroy); +void offchannel_cancel(uint64_t wdev_id, uint32_t id); -- 2.31.1