linux/net/mptcp/pm_userspace.c

// SPDX-License-Identifier: GPL-2.0
/* Multipath TCP
 *
 * Copyright (c) 2022, Intel Corporation.
 */

#include "protocol.h"

void mptcp_free_local_addr_list(struct mptcp_sock *msk)
{
	struct mptcp_pm_addr_entry *entry, *tmp;
	struct sock *sk = (struct sock *)msk;
	LIST_HEAD(free_list);

	if (!mptcp_pm_is_userspace(msk))
		return;

	spin_lock_bh(&msk->pm.lock);
	list_splice_init(&msk->pm.userspace_pm_local_addr_list, &free_list);
	spin_unlock_bh(&msk->pm.lock);

	list_for_each_entry_safe(entry, tmp, &free_list, list) {
		sock_kfree_s(sk, entry, sizeof(*entry));
	}
}

int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
					     struct mptcp_pm_addr_entry *entry)
{
	DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
	struct mptcp_pm_addr_entry *match = NULL;
	struct sock *sk = (struct sock *)msk;
	struct mptcp_pm_addr_entry *e;
	bool addr_match = false;
	bool id_match = false;
	int ret = -EINVAL;

	bitmap_zero(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);

	spin_lock_bh(&msk->pm.lock);
	list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
		addr_match = mptcp_addresses_equal(&e->addr, &entry->addr, true);
		if (addr_match && entry->addr.id == 0)
			entry->addr.id = e->addr.id;
		id_match = (e->addr.id == entry->addr.id);
		if (addr_match && id_match) {
			match = e;
			break;
		} else if (addr_match || id_match) {
			break;
		}
		__set_bit(e->addr.id, id_bitmap);
	}

	if (!match && !addr_match && !id_match) {
		/* Memory for the entry is allocated from the
		 * sock option buffer.
		 */
		e = sock_kmalloc(sk, sizeof(*e), GFP_ATOMIC);
		if (!e) {
			spin_unlock_bh(&msk->pm.lock);
			return -ENOMEM;
		}

		*e = *entry;
		if (!e->addr.id)
			e->addr.id = find_next_zero_bit(id_bitmap,
							MPTCP_PM_MAX_ADDR_ID + 1,
							1);
		list_add_tail_rcu(&e->list, &msk->pm.userspace_pm_local_addr_list);
		ret = e->addr.id;
	} else if (match) {
		ret = entry->addr.id;
	}

	spin_unlock_bh(&msk->pm.lock);
	return ret;
}