net/mac80211/link.c - linux/kernel/git/dhowells/linux-fs - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * MLO link handling
  *
  * Copyright (C) 2022 Intel Corporation
  */
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <net/mac80211.h>
 #include "ieee80211_i.h"
 #include "driver-ops.h"

 void ieee80211_link_setup(struct ieee80211_link_data *link)
 {
 	if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
 		ieee80211_mgd_setup_link(link);
 }

 void ieee80211_link_init(struct ieee80211_sub_if_data *sdata,
 			 int link_id,
 			 struct ieee80211_link_data *link,
 			 struct ieee80211_bss_conf *link_conf)
 {
 	bool deflink = link_id < 0;

 	if (link_id < 0)
 		link_id = 0;

 	rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf);
 	rcu_assign_pointer(sdata->link[link_id], link);

 	link->sdata = sdata;
 	link->link_id = link_id;
 	link->conf = link_conf;
 	link_conf->link_id = link_id;

 	INIT_WORK(&link->csa_finalize_work,
 		  ieee80211_csa_finalize_work);
 	INIT_WORK(&link->color_change_finalize_work,
 		  ieee80211_color_change_finalize_work);
 	INIT_LIST_HEAD(&link->assigned_chanctx_list);
 	INIT_LIST_HEAD(&link->reserved_chanctx_list);
 	INIT_DELAYED_WORK(&link->dfs_cac_timer_work,
 			  ieee80211_dfs_cac_timer_work);

 	if (!deflink) {
 		switch (sdata->vif.type) {
 		case NL80211_IFTYPE_AP:
 			ether_addr_copy(link_conf->addr,
 					sdata->wdev.links[link_id].addr);
 			link_conf->bssid = link_conf->addr;
 			WARN_ON(!(sdata->wdev.valid_links & BIT(link_id)));
 			break;
 		case NL80211_IFTYPE_STATION:
 			/* station sets the bssid in ieee80211_mgd_setup_link */
 			break;
 		default:
 			WARN_ON(1);
 		}
 	}
 }

 void ieee80211_link_stop(struct ieee80211_link_data *link)
 {
 	if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
 		ieee80211_mgd_stop_link(link);

 	ieee80211_link_release_channel(link);
 }

 struct link_container {
 	struct ieee80211_link_data data;
 	struct ieee80211_bss_conf conf;
 };

 static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
 				 struct link_container **links)
 {
 	LIST_HEAD(keys);
 	unsigned int link_id;

 	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
 		if (!links[link_id])
 			continue;
 		ieee80211_remove_link_keys(&links[link_id]->data, &keys);
 	}

 	synchronize_rcu();

 	ieee80211_free_key_list(sdata->local, &keys);

 	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
 		if (!links[link_id])
 			continue;
 		ieee80211_link_stop(&links[link_id]->data);
 		kfree(links[link_id]);
 	}
 }

 static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
 {
 	unsigned int i, j;

 	for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
 		struct ieee80211_link_data *link1;

 		link1 = sdata_dereference(sdata->link[i], sdata);
 		if (!link1)
 			continue;
 		for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) {
 			struct ieee80211_link_data *link2;

 			link2 = sdata_dereference(sdata->link[j], sdata);
 			if (!link2)
 				continue;

 			if (ether_addr_equal(link1->conf->addr,
 					     link2->conf->addr))
 				return -EALREADY;
 		}
 	}

 	return 0;
 }

 static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
 				      struct link_container **to_free,
 				      u16 new_links)
 {
 	u16 old_links = sdata->vif.valid_links;
 	unsigned long add = new_links & ~old_links;
 	unsigned long rem = old_links & ~new_links;
 	unsigned int link_id;
 	int ret;
 	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, *link;
 	struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS];
 	struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS];
 	bool use_deflink = old_links == 0; /* set for error case */

 	sdata_assert_lock(sdata);

 	memset(to_free, 0, sizeof(links));

 	if (old_links == new_links)
 		return 0;

 	/* if there were no old links, need to clear the pointers to deflink */
 	if (!old_links)
 		rem |= BIT(0);

 	/* allocate new link structures first */
 	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
 		link = kzalloc(sizeof(*link), GFP_KERNEL);
 		if (!link) {
 			ret = -ENOMEM;
 			goto free;
 		}
 		links[link_id] = link;
 	}

 	/* keep track of the old pointers for the driver */
 	BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf));
 	memcpy(old, sdata->vif.link_conf, sizeof(old));
 	/* and for us in error cases */
 	BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
 	memcpy(old_data, sdata->link, sizeof(old_data));

 	/* grab old links to free later */
 	for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
 		if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) {
 			/*
 			 * we must have allocated the data through this path so
 			 * we know we can free both at the same time
 			 */
 			to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
 							typeof(*links[link_id]),
 							data);
 		}

 		RCU_INIT_POINTER(sdata->link[link_id], NULL);
 		RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
 	}

 	/* link them into data structures */
 	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
 		WARN_ON(!use_deflink &&
 			rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink);

 		link = links[link_id];
 		ieee80211_link_init(sdata, link_id, &link->data, &link->conf);
 		ieee80211_link_setup(&link->data);
 	}

 	if (new_links == 0)
 		ieee80211_link_init(sdata, -1, &sdata->deflink,
 				    &sdata->vif.bss_conf);

 	sdata->vif.valid_links = new_links;

 	ret = ieee80211_check_dup_link_addrs(sdata);
 	if (!ret) {
 		/* tell the driver */
 		ret = drv_change_vif_links(sdata->local, sdata,
 					   old_links, new_links,
 					   old);
 	}

 	if (ret) {
 		/* restore config */
 		memcpy(sdata->link, old_data, sizeof(old_data));
 		memcpy(sdata->vif.link_conf, old, sizeof(old));
 		sdata->vif.valid_links = old_links;
 		/* and free (only) the newly allocated links */
 		memset(to_free, 0, sizeof(links));
 		goto free;
 	}

 	/* use deflink/bss_conf again if and only if there are no more links */
 	use_deflink = new_links == 0;

 	goto deinit;
 free:
 	/* if we failed during allocation, only free all */
 	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
 		kfree(links[link_id]);
 		links[link_id] = NULL;
 	}
 deinit:
 	if (use_deflink)
 		ieee80211_link_init(sdata, -1, &sdata->deflink,
 				    &sdata->vif.bss_conf);
 	return ret;
 }

 int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata,
 			    u16 new_links)
 {
 	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
 	int ret;

 	ret = ieee80211_vif_update_links(sdata, links, new_links);
 	ieee80211_free_links(sdata, links);

 	return ret;
 }

 void ieee80211_vif_clear_links(struct ieee80211_sub_if_data *sdata)
 {
 	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];

 	/*
 	 * The locking here is different because when we free links
 	 * in the station case we need to be able to cancel_work_sync()
 	 * something that also takes the lock.
 	 */

 	sdata_lock(sdata);
 	ieee80211_vif_update_links(sdata, links, 0);
 	sdata_unlock(sdata);

 	ieee80211_free_links(sdata, links);
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* MLO link handling
	*
	* Copyright (C) 2022 Intel Corporation
	*/
	#include <linux/slab.h>
	#include <linux/kernel.h>
	#include <net/mac80211.h>
	#include "ieee80211_i.h"
	#include "driver-ops.h"

	void ieee80211_link_setup(struct ieee80211_link_data *link)
	{
	if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
	ieee80211_mgd_setup_link(link);
	}

	void ieee80211_link_init(struct ieee80211_sub_if_data *sdata,
	int link_id,
	struct ieee80211_link_data *link,
	struct ieee80211_bss_conf *link_conf)
	{
	bool deflink = link_id < 0;

	if (link_id < 0)
	link_id = 0;

	rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf);
	rcu_assign_pointer(sdata->link[link_id], link);

	link->sdata = sdata;
	link->link_id = link_id;
	link->conf = link_conf;
	link_conf->link_id = link_id;

	INIT_WORK(&link->csa_finalize_work,
	ieee80211_csa_finalize_work);
	INIT_WORK(&link->color_change_finalize_work,
	ieee80211_color_change_finalize_work);
	INIT_LIST_HEAD(&link->assigned_chanctx_list);
	INIT_LIST_HEAD(&link->reserved_chanctx_list);
	INIT_DELAYED_WORK(&link->dfs_cac_timer_work,
	ieee80211_dfs_cac_timer_work);

	if (!deflink) {
	switch (sdata->vif.type) {
	case NL80211_IFTYPE_AP:
	ether_addr_copy(link_conf->addr,
	sdata->wdev.links[link_id].addr);
	link_conf->bssid = link_conf->addr;
	WARN_ON(!(sdata->wdev.valid_links & BIT(link_id)));
	break;
	case NL80211_IFTYPE_STATION:
	/* station sets the bssid in ieee80211_mgd_setup_link */
	break;
	default:
	WARN_ON(1);
	}
	}
	}

	void ieee80211_link_stop(struct ieee80211_link_data *link)
	{
	if (link->sdata->vif.type == NL80211_IFTYPE_STATION)
	ieee80211_mgd_stop_link(link);

	ieee80211_link_release_channel(link);
	}

	struct link_container {
	struct ieee80211_link_data data;
	struct ieee80211_bss_conf conf;
	};

	static void ieee80211_free_links(struct ieee80211_sub_if_data *sdata,
	struct link_container **links)
	{
	LIST_HEAD(keys);
	unsigned int link_id;

	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
	if (!links[link_id])
	continue;
	ieee80211_remove_link_keys(&links[link_id]->data, &keys);
	}

	synchronize_rcu();

	ieee80211_free_key_list(sdata->local, &keys);

	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
	if (!links[link_id])
	continue;
	ieee80211_link_stop(&links[link_id]->data);
	kfree(links[link_id]);
	}
	}

	static int ieee80211_check_dup_link_addrs(struct ieee80211_sub_if_data *sdata)
	{
	unsigned int i, j;

	for (i = 0; i < IEEE80211_MLD_MAX_NUM_LINKS; i++) {
	struct ieee80211_link_data *link1;

	link1 = sdata_dereference(sdata->link[i], sdata);
	if (!link1)
	continue;
	for (j = i + 1; j < IEEE80211_MLD_MAX_NUM_LINKS; j++) {
	struct ieee80211_link_data *link2;

	link2 = sdata_dereference(sdata->link[j], sdata);
	if (!link2)
	continue;

	if (ether_addr_equal(link1->conf->addr,
	link2->conf->addr))
	return -EALREADY;
	}
	}

	return 0;
	}

	static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
	struct link_container **to_free,
	u16 new_links)
	{
	u16 old_links = sdata->vif.valid_links;
	unsigned long add = new_links & ~old_links;
	unsigned long rem = old_links & ~new_links;
	unsigned int link_id;
	int ret;
	struct link_container links[IEEE80211_MLD_MAX_NUM_LINKS] = {}, link;
	struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS];
	struct ieee80211_link_data *old_data[IEEE80211_MLD_MAX_NUM_LINKS];
	bool use_deflink = old_links == 0; /* set for error case */

	sdata_assert_lock(sdata);

	memset(to_free, 0, sizeof(links));

	if (old_links == new_links)
	return 0;

	/* if there were no old links, need to clear the pointers to deflink */
	if (!old_links)
	rem \|= BIT(0);

	/* allocate new link structures first */
	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
	link = kzalloc(sizeof(*link), GFP_KERNEL);
	if (!link) {
	ret = -ENOMEM;
	goto free;
	}
	links[link_id] = link;
	}

	/* keep track of the old pointers for the driver */
	BUILD_BUG_ON(sizeof(old) != sizeof(sdata->vif.link_conf));
	memcpy(old, sdata->vif.link_conf, sizeof(old));
	/* and for us in error cases */
	BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
	memcpy(old_data, sdata->link, sizeof(old_data));

	/* grab old links to free later */
	for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
	if (rcu_access_pointer(sdata->link[link_id]) != &sdata->deflink) {
	/*
	* we must have allocated the data through this path so
	* we know we can free both at the same time
	*/
	to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
	typeof(*links[link_id]),
	data);
	}

	RCU_INIT_POINTER(sdata->link[link_id], NULL);
	RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
	}

	/* link them into data structures */
	for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
	WARN_ON(!use_deflink &&
	rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink);

	link = links[link_id];
	ieee80211_link_init(sdata, link_id, &link->data, &link->conf);
	ieee80211_link_setup(&link->data);
	}

	if (new_links == 0)
	ieee80211_link_init(sdata, -1, &sdata->deflink,
	&sdata->vif.bss_conf);

	sdata->vif.valid_links = new_links;

	ret = ieee80211_check_dup_link_addrs(sdata);
	if (!ret) {
	/* tell the driver */
	ret = drv_change_vif_links(sdata->local, sdata,
	old_links, new_links,
	old);
	}

	if (ret) {
	/* restore config */
	memcpy(sdata->link, old_data, sizeof(old_data));
	memcpy(sdata->vif.link_conf, old, sizeof(old));
	sdata->vif.valid_links = old_links;
	/* and free (only) the newly allocated links */
	memset(to_free, 0, sizeof(links));
	goto free;
	}

	/* use deflink/bss_conf again if and only if there are no more links */
	use_deflink = new_links == 0;

	goto deinit;
	free:
	/* if we failed during allocation, only free all */
	for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
	kfree(links[link_id]);
	links[link_id] = NULL;
	}
	deinit:
	if (use_deflink)
	ieee80211_link_init(sdata, -1, &sdata->deflink,
	&sdata->vif.bss_conf);
	return ret;
	}

	int ieee80211_vif_set_links(struct ieee80211_sub_if_data *sdata,
	u16 new_links)
	{
	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];
	int ret;

	ret = ieee80211_vif_update_links(sdata, links, new_links);
	ieee80211_free_links(sdata, links);

	return ret;
	}

	void ieee80211_vif_clear_links(struct ieee80211_sub_if_data *sdata)
	{
	struct link_container *links[IEEE80211_MLD_MAX_NUM_LINKS];

	/*
	* The locking here is different because when we free links
	* in the station case we need to be able to cancel_work_sync()
	* something that also takes the lock.
	*/

	sdata_lock(sdata);
	ieee80211_vif_update_links(sdata, links, 0);
	sdata_unlock(sdata);

	ieee80211_free_links(sdata, links);
	}