// SPDX-License-Identifier: GPL-2.0 /* Multipath TCP * * Copyright (c) 2020, Red Hat, Inc. */ #define pr_fmt(fmt) "MPTCP: " fmt #include <linux/inet.h> #include <linux/kernel.h> #include <net/tcp.h> #include <net/netns/generic.h> #include <net/mptcp.h> #include <net/genetlink.h> #include <uapi/linux/mptcp.h> #include "protocol.h" #include "mib.h" /* forward declaration */ static struct genl_family mptcp_genl_family; static int pm_nl_pernet_id; struct mptcp_pm_add_entry { struct list_head list; struct mptcp_addr_info addr; struct timer_list add_timer; struct mptcp_sock *sock; u8 retrans_times; }; struct pm_nl_pernet { /* protects pernet updates */ spinlock_t lock; struct list_head local_addr_list; unsigned int addrs; unsigned int stale_loss_cnt; unsigned int add_addr_signal_max; unsigned int add_addr_accept_max; unsigned int local_addr_max; unsigned int subflows_max; unsigned int next_id; DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); }; #define MPTCP_PM_ADDR_MAX 8 #define ADD_ADDR_RETRANS_MAX 3 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net) { return net_generic(net, pm_nl_pernet_id); } static struct pm_nl_pernet * pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk) { return pm_nl_get_pernet(sock_net((struct sock *)msk)); } bool mptcp_addresses_equal(const struct mptcp_addr_info *a, const struct mptcp_addr_info *b, bool use_port) { bool addr_equals = false; if (a->family == b->family) { if (a->family == AF_INET) addr_equals = a->addr.s_addr == b->addr.s_addr; #if IS_ENABLED(CONFIG_MPTCP_IPV6) else addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6); } else if (a->family == AF_INET) { if (ipv6_addr_v4mapped(&b->addr6)) addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3]; } else if (b->family == AF_INET) { if (ipv6_addr_v4mapped(&a->addr6)) addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr; #endif } if (!addr_equals) return false; if (!use_port) return true; return a->port == b->port; } static void local_address(const struct sock_common *skc, struct mptcp_addr_info *addr) { addr->family = skc->skc_family; addr->port = htons(skc->skc_num); if (addr->family == AF_INET) addr->addr.s_addr = skc->skc_rcv_saddr; #if IS_ENABLED(CONFIG_MPTCP_IPV6) else if (addr->family == AF_INET6) addr->addr6 = skc->skc_v6_rcv_saddr; #endif } static void remote_address(const struct sock_common *skc, struct mptcp_addr_info *addr) { addr->family = skc->skc_family; addr->port = skc->skc_dport; if (addr->family == AF_INET) addr->addr.s_addr = skc->skc_daddr; #if IS_ENABLED(CONFIG_MPTCP_IPV6) else if (addr->family == AF_INET6) addr->addr6 = skc->skc_v6_daddr; #endif } static bool lookup_subflow_by_saddr(const struct list_head *list, const struct mptcp_addr_info *saddr) { struct mptcp_subflow_context *subflow; struct mptcp_addr_info cur; struct sock_common *skc; list_for_each_entry(subflow, list, node) { skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow); local_address(skc, &cur); if (mptcp_addresses_equal(&cur, saddr, saddr->port)) return true; } return false; } static bool lookup_subflow_by_daddr(const struct list_head *list, const struct mptcp_addr_info *daddr) { struct mptcp_subflow_context *subflow; struct mptcp_addr_info cur; struct sock_common *skc; list_for_each_entry(subflow, list, node) { skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow); remote_address(skc, &cur); if (mptcp_addresses_equal(&cur, daddr, daddr->port)) return true; } return false; } static struct mptcp_pm_addr_entry * select_local_address(const struct pm_nl_pernet *pernet, const struct mptcp_sock *msk) { const struct sock *sk = (const struct sock *)msk; struct mptcp_pm_addr_entry *entry, *ret = NULL; msk_owned_by_me(msk); rcu_read_lock(); list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)) continue; if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap)) continue; if (entry->addr.family != sk->sk_family) { #if IS_ENABLED(CONFIG_MPTCP_IPV6) if ((entry->addr.family == AF_INET && !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) || (sk->sk_family == AF_INET && !ipv6_addr_v4mapped(&entry->addr.addr6))) #endif continue; } ret = entry; break; } rcu_read_unlock(); return ret; } static struct mptcp_pm_addr_entry * select_signal_address(struct pm_nl_pernet *pernet, const struct mptcp_sock *msk) { struct mptcp_pm_addr_entry *entry, *ret = NULL; rcu_read_lock(); /* do not keep any additional per socket state, just signal * the address list in order. * Note: removal from the local address list during the msk life-cycle * can lead to additional addresses not being announced. */ list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap)) continue; if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) continue; ret = entry; break; } rcu_read_unlock(); return ret; } unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk) { const struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); return READ_ONCE(pernet->add_addr_signal_max); } EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max); unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk) { struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); return READ_ONCE(pernet->add_addr_accept_max); } EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max); unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk) { struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); return READ_ONCE(pernet->subflows_max); } EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max); unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk) { struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); return READ_ONCE(pernet->local_addr_max); } EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max); bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk) { struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) || (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) { WRITE_ONCE(msk->pm.work_pending, false); return false; } return true; } struct mptcp_pm_add_entry * mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk, const struct mptcp_addr_info *addr) { struct mptcp_pm_add_entry *entry; lockdep_assert_held(&msk->pm.lock); list_for_each_entry(entry, &msk->pm.anno_list, list) { if (mptcp_addresses_equal(&entry->addr, addr, true)) return entry; } return NULL; } bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk) { struct mptcp_pm_add_entry *entry; struct mptcp_addr_info saddr; bool ret = false; local_address((struct sock_common *)sk, &saddr); spin_lock_bh(&msk->pm.lock); list_for_each_entry(entry, &msk->pm.anno_list, list) { if (mptcp_addresses_equal(&entry->addr, &saddr, true)) { ret = true; goto out; } } out: spin_unlock_bh(&msk->pm.lock); return ret; } static void mptcp_pm_add_timer(struct timer_list *timer) { struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer); struct mptcp_sock *msk = entry->sock; struct sock *sk = (struct sock *)msk; pr_debug("msk=%p", msk); if (!msk) return; if (inet_sk_state_load(sk) == TCP_CLOSE) return; if (!entry->addr.id) return; if (mptcp_pm_should_add_signal_addr(msk)) { sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8); goto out; } spin_lock_bh(&msk->pm.lock); if (!mptcp_pm_should_add_signal_addr(msk)) { pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id); mptcp_pm_announce_addr(msk, &entry->addr, false); mptcp_pm_add_addr_send_ack(msk); entry->retrans_times++; } if (entry->retrans_times < ADD_ADDR_RETRANS_MAX) sk_reset_timer(sk, timer, jiffies + mptcp_get_add_addr_timeout(sock_net(sk))); spin_unlock_bh(&msk->pm.lock); if (entry->retrans_times == ADD_ADDR_RETRANS_MAX) mptcp_pm_subflow_established(msk); out: __sock_put(sk); } struct mptcp_pm_add_entry * mptcp_pm_del_add_timer(struct mptcp_sock *msk, const struct mptcp_addr_info *addr, bool check_id) { struct mptcp_pm_add_entry *entry; struct sock *sk = (struct sock *)msk; spin_lock_bh(&msk->pm.lock); entry = mptcp_lookup_anno_list_by_saddr(msk, addr); if (entry && (!check_id || entry->addr.id == addr->id)) entry->retrans_times = ADD_ADDR_RETRANS_MAX; spin_unlock_bh(&msk->pm.lock); if (entry && (!check_id || entry->addr.id == addr->id)) sk_stop_timer_sync(sk, &entry->add_timer); return entry; } bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk, const struct mptcp_pm_addr_entry *entry) { struct mptcp_pm_add_entry *add_entry = NULL; struct sock *sk = (struct sock *)msk; struct net *net = sock_net(sk); lockdep_assert_held(&msk->pm.lock); add_entry = mptcp_lookup_anno_list_by_saddr(msk, &entry->addr); if (add_entry) { if (mptcp_pm_is_kernel(msk)) return false; sk_reset_timer(sk, &add_entry->add_timer, jiffies + mptcp_get_add_addr_timeout(net)); return true; } add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC); if (!add_entry) return false; list_add(&add_entry->list, &msk->pm.anno_list); add_entry->addr = entry->addr; add_entry->sock = msk; add_entry->retrans_times = 0; timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0); sk_reset_timer(sk, &add_entry->add_timer, jiffies + mptcp_get_add_addr_timeout(net)); return true; } void mptcp_pm_free_anno_list(struct mptcp_sock *msk) { struct mptcp_pm_add_entry *entry, *tmp; struct sock *sk = (struct sock *)msk; LIST_HEAD(free_list); pr_debug("msk=%p", msk); spin_lock_bh(&msk->pm.lock); list_splice_init(&msk->pm.anno_list, &free_list); spin_unlock_bh(&msk->pm.lock); list_for_each_entry_safe(entry, tmp, &free_list, list) { sk_stop_timer_sync(sk, &entry->add_timer); kfree(entry); } } static bool lookup_address_in_vec(const struct mptcp_addr_info *addrs, unsigned int nr, const struct mptcp_addr_info *addr) { int i; for (i = 0; i < nr; i++) { if (addrs[i].id == addr->id) return true; } return false; } /* Fill all the remote addresses into the array addrs[], * and return the array size. */ static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk, bool fullmesh, struct mptcp_addr_info *addrs) { bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0); struct sock *sk = (struct sock *)msk, *ssk; struct mptcp_subflow_context *subflow; struct mptcp_addr_info remote = { 0 }; unsigned int subflows_max; int i = 0; subflows_max = mptcp_pm_get_subflows_max(msk); remote_address((struct sock_common *)sk, &remote); /* Non-fullmesh endpoint, fill in the single entry * corresponding to the primary MPC subflow remote address */ if (!fullmesh) { if (deny_id0) return 0; msk->pm.subflows++; addrs[i++] = remote; } else { mptcp_for_each_subflow(msk, subflow) { ssk = mptcp_subflow_tcp_sock(subflow); remote_address((struct sock_common *)ssk, &addrs[i]); addrs[i].id = subflow->remote_id; if (deny_id0 && !addrs[i].id) continue; if (!lookup_address_in_vec(addrs, i, &addrs[i]) && msk->pm.subflows < subflows_max) { msk->pm.subflows++; i++; } } } return i; } static void __mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow, bool prio, bool backup) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); bool slow; pr_debug("send ack for %s", prio ? "mp_prio" : (mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr")); slow = lock_sock_fast(ssk); if (prio) { if (subflow->backup != backup) msk->last_snd = NULL; subflow->send_mp_prio = 1; subflow->backup = backup; subflow->request_bkup = backup; } __mptcp_subflow_send_ack(ssk); unlock_sock_fast(ssk, slow); } static void mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow, bool prio, bool backup) { spin_unlock_bh(&msk->pm.lock); __mptcp_pm_send_ack(msk, subflow, prio, backup); spin_lock_bh(&msk->pm.lock); } static struct mptcp_pm_addr_entry * __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id) { struct mptcp_pm_addr_entry *entry; list_for_each_entry(entry, &pernet->local_addr_list, list) { if (entry->addr.id == id) return entry; } return NULL; } static struct mptcp_pm_addr_entry * __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info, bool lookup_by_id) { struct mptcp_pm_addr_entry *entry; list_for_each_entry(entry, &pernet->local_addr_list, list) { if ((!lookup_by_id && mptcp_addresses_equal(&entry->addr, info, entry->addr.port)) || (lookup_by_id && entry->addr.id == info->id)) return entry; } return NULL; } static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) { struct sock *sk = (struct sock *)msk; struct mptcp_pm_addr_entry *local; unsigned int add_addr_signal_max; unsigned int local_addr_max; struct pm_nl_pernet *pernet; unsigned int subflows_max; pernet = pm_nl_get_pernet(sock_net(sk)); add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk); local_addr_max = mptcp_pm_get_local_addr_max(msk); subflows_max = mptcp_pm_get_subflows_max(msk); /* do lazy endpoint usage accounting for the MPC subflows */ if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first); struct mptcp_pm_addr_entry *entry; struct mptcp_addr_info mpc_addr; bool backup = false; local_address((struct sock_common *)msk->first, &mpc_addr); rcu_read_lock(); entry = __lookup_addr(pernet, &mpc_addr, false); if (entry) { __clear_bit(entry->addr.id, msk->pm.id_avail_bitmap); msk->mpc_endpoint_id = entry->addr.id; backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP); } rcu_read_unlock(); if (backup) mptcp_pm_send_ack(msk, subflow, true, backup); msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED); } pr_debug("local %d:%d signal %d:%d subflows %d:%d\n", msk->pm.local_addr_used, local_addr_max, msk->pm.add_addr_signaled, add_addr_signal_max, msk->pm.subflows, subflows_max); /* check first for announce */ if (msk->pm.add_addr_signaled < add_addr_signal_max) { local = select_signal_address(pernet, msk); /* due to racing events on both ends we can reach here while * previous add address is still running: if we invoke now * mptcp_pm_announce_addr(), that will fail and the * corresponding id will be marked as used. * Instead let the PM machinery reschedule us when the * current address announce will be completed. */ if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL)) return; if (local) { if (mptcp_pm_alloc_anno_list(msk, local)) { __clear_bit(local->addr.id, msk->pm.id_avail_bitmap); msk->pm.add_addr_signaled++; mptcp_pm_announce_addr(msk, &local->addr, false); mptcp_pm_nl_addr_send_ack(msk); } } } /* check if should create a new subflow */ while (msk->pm.local_addr_used < local_addr_max && msk->pm.subflows < subflows_max) { struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX]; bool fullmesh; int i, nr; local = select_local_address(pernet, msk); if (!local) break; fullmesh = !!(local->flags & MPTCP_PM_ADDR_FLAG_FULLMESH); msk->pm.local_addr_used++; nr = fill_remote_addresses_vec(msk, fullmesh, addrs); if (nr) __clear_bit(local->addr.id, msk->pm.id_avail_bitmap); spin_unlock_bh(&msk->pm.lock); for (i = 0; i < nr; i++) __mptcp_subflow_connect(sk, &local->addr, &addrs[i]); spin_lock_bh(&msk->pm.lock); } mptcp_pm_nl_check_work_pending(msk); } static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk) { mptcp_pm_create_subflow_or_signal_addr(msk); } static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk) { mptcp_pm_create_subflow_or_signal_addr(msk); } /* Fill all the local addresses into the array addrs[], * and return the array size. */ static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk, struct mptcp_addr_info *addrs) { struct sock *sk = (struct sock *)msk; struct mptcp_pm_addr_entry *entry; struct mptcp_addr_info local; struct pm_nl_pernet *pernet; unsigned int subflows_max; int i = 0; pernet = pm_nl_get_pernet_from_msk(msk); subflows_max = mptcp_pm_get_subflows_max(msk); rcu_read_lock(); list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH)) continue; if (entry->addr.family != sk->sk_family) { #if IS_ENABLED(CONFIG_MPTCP_IPV6) if ((entry->addr.family == AF_INET && !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) || (sk->sk_family == AF_INET && !ipv6_addr_v4mapped(&entry->addr.addr6))) #endif continue; } if (msk->pm.subflows < subflows_max) { msk->pm.subflows++; addrs[i++] = entry->addr; } } rcu_read_unlock(); /* If the array is empty, fill in the single * 'IPADDRANY' local address */ if (!i) { memset(&local, 0, sizeof(local)); local.family = msk->pm.remote.family; msk->pm.subflows++; addrs[i++] = local; } return i; } static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) { struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX]; struct sock *sk = (struct sock *)msk; unsigned int add_addr_accept_max; struct mptcp_addr_info remote; unsigned int subflows_max; int i, nr; add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk); subflows_max = mptcp_pm_get_subflows_max(msk); pr_debug("accepted %d:%d remote family %d", msk->pm.add_addr_accepted, add_addr_accept_max, msk->pm.remote.family); remote = msk->pm.remote; mptcp_pm_announce_addr(msk, &remote, true); mptcp_pm_nl_addr_send_ack(msk); if (lookup_subflow_by_daddr(&msk->conn_list, &remote)) return; /* pick id 0 port, if none is provided the remote address */ if (!remote.port) remote.port = sk->sk_dport; /* connect to the specified remote address, using whatever * local address the routing configuration will pick. */ nr = fill_local_addresses_vec(msk, addrs); msk->pm.add_addr_accepted++; if (msk->pm.add_addr_accepted >= add_addr_accept_max || msk->pm.subflows >= subflows_max) WRITE_ONCE(msk->pm.accept_addr, false); spin_unlock_bh(&msk->pm.lock); for (i = 0; i < nr; i++) __mptcp_subflow_connect(sk, &addrs[i], &remote); spin_lock_bh(&msk->pm.lock); } void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk) { struct mptcp_subflow_context *subflow; msk_owned_by_me(msk); lockdep_assert_held(&msk->pm.lock); if (!mptcp_pm_should_add_signal(msk) && !mptcp_pm_should_rm_signal(msk)) return; subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node); if (subflow) mptcp_pm_send_ack(msk, subflow, false, false); } int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk, struct mptcp_addr_info *addr, struct mptcp_addr_info *rem, u8 bkup) { struct mptcp_subflow_context *subflow; pr_debug("bkup=%d", bkup); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); struct mptcp_addr_info local, remote; local_address((struct sock_common *)ssk, &local); if (!mptcp_addresses_equal(&local, addr, addr->port)) continue; if (rem && rem->family != AF_UNSPEC) { remote_address((struct sock_common *)ssk, &remote); if (!mptcp_addresses_equal(&remote, rem, rem->port)) continue; } __mptcp_pm_send_ack(msk, subflow, true, bkup); return 0; } return -EINVAL; } static bool mptcp_local_id_match(const struct mptcp_sock *msk, u8 local_id, u8 id) { return local_id == id || (!local_id && msk->mpc_endpoint_id == id); } static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list, enum linux_mptcp_mib_field rm_type) { struct mptcp_subflow_context *subflow, *tmp; struct sock *sk = (struct sock *)msk; u8 i; pr_debug("%s rm_list_nr %d", rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr); msk_owned_by_me(msk); if (sk->sk_state == TCP_LISTEN) return; if (!rm_list->nr) return; if (list_empty(&msk->conn_list)) return; for (i = 0; i < rm_list->nr; i++) { u8 rm_id = rm_list->ids[i]; bool removed = false; mptcp_for_each_subflow_safe(msk, subflow, tmp) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); int how = RCV_SHUTDOWN | SEND_SHUTDOWN; u8 id = subflow->local_id; if (rm_type == MPTCP_MIB_RMADDR && subflow->remote_id != rm_id) continue; if (rm_type == MPTCP_MIB_RMSUBFLOW && !mptcp_local_id_match(msk, id, rm_id)) continue; pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u", rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", i, rm_id, subflow->local_id, subflow->remote_id, msk->mpc_endpoint_id); spin_unlock_bh(&msk->pm.lock); mptcp_subflow_shutdown(sk, ssk, how); /* the following takes care of updating the subflows counter */ mptcp_close_ssk(sk, ssk, subflow); spin_lock_bh(&msk->pm.lock); removed = true; __MPTCP_INC_STATS(sock_net(sk), rm_type); } if (rm_type == MPTCP_MIB_RMSUBFLOW) __set_bit(rm_id ? rm_id : msk->mpc_endpoint_id, msk->pm.id_avail_bitmap); if (!removed) continue; if (!mptcp_pm_is_kernel(msk)) continue; if (rm_type == MPTCP_MIB_RMADDR) { msk->pm.add_addr_accepted--; WRITE_ONCE(msk->pm.accept_addr, true); } else if (rm_type == MPTCP_MIB_RMSUBFLOW) { msk->pm.local_addr_used--; } } } static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk) { mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR); } void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list) { mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW); } void mptcp_pm_nl_work(struct mptcp_sock *msk) { struct mptcp_pm_data *pm = &msk->pm; msk_owned_by_me(msk); if (!(pm->status & MPTCP_PM_WORK_MASK)) return; spin_lock_bh(&msk->pm.lock); pr_debug("msk=%p status=%x", msk, pm->status); if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) { pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED); mptcp_pm_nl_add_addr_received(msk); } if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) { pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK); mptcp_pm_nl_addr_send_ack(msk); } if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) { pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED); mptcp_pm_nl_rm_addr_received(msk); } if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) { pm->status &= ~BIT(MPTCP_PM_ESTABLISHED); mptcp_pm_nl_fully_established(msk); } if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) { pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED); mptcp_pm_nl_subflow_established(msk); } spin_unlock_bh(&msk->pm.lock); } static bool address_use_port(struct mptcp_pm_addr_entry *entry) { return (entry->flags & (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) == MPTCP_PM_ADDR_FLAG_SIGNAL; } /* caller must ensure the RCU grace period is already elapsed */ static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry) { if (entry->lsk) sock_release(entry->lsk); kfree(entry); } static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, struct mptcp_pm_addr_entry *entry) { struct mptcp_pm_addr_entry *cur, *del_entry = NULL; unsigned int addr_max; int ret = -EINVAL; spin_lock_bh(&pernet->lock); /* to keep the code simple, don't do IDR-like allocation for address ID, * just bail when we exceed limits */ if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID) pernet->next_id = 1; if (pernet->addrs >= MPTCP_PM_ADDR_MAX) goto out; if (test_bit(entry->addr.id, pernet->id_bitmap)) goto out; /* do not insert duplicate address, differentiate on port only * singled addresses */ if (!address_use_port(entry)) entry->addr.port = 0; list_for_each_entry(cur, &pernet->local_addr_list, list) { if (mptcp_addresses_equal(&cur->addr, &entry->addr, cur->addr.port || entry->addr.port)) { /* allow replacing the exiting endpoint only if such * endpoint is an implicit one and the user-space * did not provide an endpoint id */ if (!(cur->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)) goto out; if (entry->addr.id) goto out; pernet->addrs--; entry->addr.id = cur->addr.id; list_del_rcu(&cur->list); del_entry = cur; break; } } if (!entry->addr.id) { find_next: entry->addr.id = find_next_zero_bit(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1, pernet->next_id); if (!entry->addr.id && pernet->next_id != 1) { pernet->next_id = 1; goto find_next; } } if (!entry->addr.id) goto out; __set_bit(entry->addr.id, pernet->id_bitmap); if (entry->addr.id > pernet->next_id) pernet->next_id = entry->addr.id; if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) { addr_max = pernet->add_addr_signal_max; WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1); } if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) { addr_max = pernet->local_addr_max; WRITE_ONCE(pernet->local_addr_max, addr_max + 1); } pernet->addrs++; if (!entry->addr.port) list_add_tail_rcu(&entry->list, &pernet->local_addr_list); else list_add_rcu(&entry->list, &pernet->local_addr_list); ret = entry->addr.id; out: spin_unlock_bh(&pernet->lock); /* just replaced an existing entry, free it */ if (del_entry) { synchronize_rcu(); __mptcp_pm_release_addr_entry(del_entry); } return ret; } static int mptcp_pm_nl_create_listen_socket(struct sock *sk, struct mptcp_pm_addr_entry *entry) { int addrlen = sizeof(struct sockaddr_in); struct sockaddr_storage addr; struct mptcp_sock *msk; struct socket *ssock; int backlog = 1024; int err; err = sock_create_kern(sock_net(sk), entry->addr.family, SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk); if (err) return err; msk = mptcp_sk(entry->lsk->sk); if (!msk) { err = -EINVAL; goto out; } ssock = __mptcp_nmpc_socket(msk); if (!ssock) { err = -EINVAL; goto out; } mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family); #if IS_ENABLED(CONFIG_MPTCP_IPV6) if (entry->addr.family == AF_INET6) addrlen = sizeof(struct sockaddr_in6); #endif err = kernel_bind(ssock, (struct sockaddr *)&addr, addrlen); if (err) { pr_warn("kernel_bind error, err=%d", err); goto out; } err = kernel_listen(ssock, backlog); if (err) { pr_warn("kernel_listen error, err=%d", err); goto out; } return 0; out: sock_release(entry->lsk); return err; } int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) { struct mptcp_pm_addr_entry *entry; struct mptcp_addr_info skc_local; struct mptcp_addr_info msk_local; struct pm_nl_pernet *pernet; int ret = -1; if (WARN_ON_ONCE(!msk)) return -1; /* The 0 ID mapping is defined by the first subflow, copied into the msk * addr */ local_address((struct sock_common *)msk, &msk_local); local_address((struct sock_common *)skc, &skc_local); if (mptcp_addresses_equal(&msk_local, &skc_local, false)) return 0; if (mptcp_pm_is_userspace(msk)) return mptcp_userspace_pm_get_local_id(msk, &skc_local); pernet = pm_nl_get_pernet_from_msk(msk); rcu_read_lock(); list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { if (mptcp_addresses_equal(&entry->addr, &skc_local, entry->addr.port)) { ret = entry->addr.id; break; } } rcu_read_unlock(); if (ret >= 0) return ret; /* address not found, add to local list */ entry = kmalloc(sizeof(*entry), GFP_ATOMIC); if (!entry) return -ENOMEM; entry->addr = skc_local; entry->addr.id = 0; entry->addr.port = 0; entry->ifindex = 0; entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT; entry->lsk = NULL; ret = mptcp_pm_nl_append_new_local_addr(pernet, entry); if (ret < 0) kfree(entry); return ret; } #define MPTCP_PM_CMD_GRP_OFFSET 0 #define MPTCP_PM_EV_GRP_OFFSET 1 static const struct genl_multicast_group mptcp_pm_mcgrps[] = { [MPTCP_PM_CMD_GRP_OFFSET] = { .name = MPTCP_PM_CMD_GRP_NAME, }, [MPTCP_PM_EV_GRP_OFFSET] = { .name = MPTCP_PM_EV_GRP_NAME, .flags = GENL_UNS_ADMIN_PERM, }, }; static const struct nla_policy mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = { [MPTCP_PM_ADDR_ATTR_FAMILY] = { .type = NLA_U16, }, [MPTCP_PM_ADDR_ATTR_ID] = { .type = NLA_U8, }, [MPTCP_PM_ADDR_ATTR_ADDR4] = { .type = NLA_U32, }, [MPTCP_PM_ADDR_ATTR_ADDR6] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)), [MPTCP_PM_ADDR_ATTR_PORT] = { .type = NLA_U16 }, [MPTCP_PM_ADDR_ATTR_FLAGS] = { .type = NLA_U32 }, [MPTCP_PM_ADDR_ATTR_IF_IDX] = { .type = NLA_S32 }, }; static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = { [MPTCP_PM_ATTR_ADDR] = NLA_POLICY_NESTED(mptcp_pm_addr_policy), [MPTCP_PM_ATTR_RCV_ADD_ADDRS] = { .type = NLA_U32, }, [MPTCP_PM_ATTR_SUBFLOWS] = { .type = NLA_U32, }, [MPTCP_PM_ATTR_TOKEN] = { .type = NLA_U32, }, [MPTCP_PM_ATTR_LOC_ID] = { .type = NLA_U8, }, [MPTCP_PM_ATTR_ADDR_REMOTE] = NLA_POLICY_NESTED(mptcp_pm_addr_policy), }; void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk) { struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk); struct sock *sk = (struct sock *)msk; unsigned int active_max_loss_cnt; struct net *net = sock_net(sk); unsigned int stale_loss_cnt; bool slow; stale_loss_cnt = mptcp_stale_loss_cnt(net); if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt) return; /* look for another available subflow not in loss state */ active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1); mptcp_for_each_subflow(msk, iter) { if (iter != subflow && mptcp_subflow_active(iter) && iter->stale_count < active_max_loss_cnt) { /* we have some alternatives, try to mark this subflow as idle ...*/ slow = lock_sock_fast(ssk); if (!tcp_rtx_and_write_queues_empty(ssk)) { subflow->stale = 1; __mptcp_retransmit_pending_data(sk); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_SUBFLOWSTALE); } unlock_sock_fast(ssk, slow); /* always try to push the pending data regardless of re-injections: * we can possibly use backup subflows now, and subflow selection * is cheap under the msk socket lock */ __mptcp_push_pending(sk, 0); return; } } } static int mptcp_pm_family_to_addr(int family) { #if IS_ENABLED(CONFIG_MPTCP_IPV6) if (family == AF_INET6) return MPTCP_PM_ADDR_ATTR_ADDR6; #endif return MPTCP_PM_ADDR_ATTR_ADDR4; } static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[], const struct nlattr *attr, struct genl_info *info, struct mptcp_addr_info *addr, bool require_family) { int err, addr_addr; if (!attr) { GENL_SET_ERR_MSG(info, "missing address info"); return -EINVAL; } /* no validation needed - was already done via nested policy */ err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr, mptcp_pm_addr_policy, info->extack); if (err) return err; if (tb[MPTCP_PM_ADDR_ATTR_ID]) addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]); if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) { if (!require_family) return err; NL_SET_ERR_MSG_ATTR(info->extack, attr, "missing family"); return -EINVAL; } addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]); if (addr->family != AF_INET #if IS_ENABLED(CONFIG_MPTCP_IPV6) && addr->family != AF_INET6 #endif ) { NL_SET_ERR_MSG_ATTR(info->extack, attr, "unknown address family"); return -EINVAL; } addr_addr = mptcp_pm_family_to_addr(addr->family); if (!tb[addr_addr]) { NL_SET_ERR_MSG_ATTR(info->extack, attr, "missing address data"); return -EINVAL; } #if IS_ENABLED(CONFIG_MPTCP_IPV6) if (addr->family == AF_INET6) addr->addr6 = nla_get_in6_addr(tb[addr_addr]); else #endif addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]); if (tb[MPTCP_PM_ADDR_ATTR_PORT]) addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT])); return err; } int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info, struct mptcp_addr_info *addr) { struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1]; memset(addr, 0, sizeof(*addr)); return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true); } int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info, bool require_family, struct mptcp_pm_addr_entry *entry) { struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1]; int err; memset(entry, 0, sizeof(*entry)); err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family); if (err) return err; if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) { u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]); entry->ifindex = val; } if (tb[MPTCP_PM_ADDR_ATTR_FLAGS]) entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]); if (tb[MPTCP_PM_ADDR_ATTR_PORT]) entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT])); return 0; } static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info) { return pm_nl_get_pernet(genl_info_net(info)); } static int mptcp_nl_add_subflow_or_signal_addr(struct net *net) { struct mptcp_sock *msk; long s_slot = 0, s_num = 0; while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { struct sock *sk = (struct sock *)msk; if (!READ_ONCE(msk->fully_established) || mptcp_pm_is_userspace(msk)) goto next; lock_sock(sk); spin_lock_bh(&msk->pm.lock); mptcp_pm_create_subflow_or_signal_addr(msk); spin_unlock_bh(&msk->pm.lock); release_sock(sk); next: sock_put(sk); cond_resched(); } return 0; } static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) { struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; struct pm_nl_pernet *pernet = genl_info_pm_nl(info); struct mptcp_pm_addr_entry addr, *entry; int ret; ret = mptcp_pm_parse_entry(attr, info, true, &addr); if (ret < 0) return ret; if (addr.addr.port && !(addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) { GENL_SET_ERR_MSG(info, "flags must have signal when using port"); return -EINVAL; } if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL && addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) { GENL_SET_ERR_MSG(info, "flags mustn't have both signal and fullmesh"); return -EINVAL; } if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) { GENL_SET_ERR_MSG(info, "can't create IMPLICIT endpoint"); return -EINVAL; } entry = kmalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT); if (!entry) { GENL_SET_ERR_MSG(info, "can't allocate addr"); return -ENOMEM; } *entry = addr; if (entry->addr.port) { ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry); if (ret) { GENL_SET_ERR_MSG(info, "create listen socket error"); kfree(entry); return ret; } } ret = mptcp_pm_nl_append_new_local_addr(pernet, entry); if (ret < 0) { GENL_SET_ERR_MSG(info, "too many addresses or duplicate one"); if (entry->lsk) sock_release(entry->lsk); kfree(entry); return ret; } mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk)); return 0; } int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id, u8 *flags, int *ifindex) { struct mptcp_pm_addr_entry *entry; struct sock *sk = (struct sock *)msk; struct net *net = sock_net(sk); *flags = 0; *ifindex = 0; if (id) { if (mptcp_pm_is_userspace(msk)) return mptcp_userspace_pm_get_flags_and_ifindex_by_id(msk, id, flags, ifindex); rcu_read_lock(); entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id); if (entry) { *flags = entry->flags; *ifindex = entry->ifindex; } rcu_read_unlock(); } return 0; } static bool remove_anno_list_by_saddr(struct mptcp_sock *msk, const struct mptcp_addr_info *addr) { struct mptcp_pm_add_entry *entry; entry = mptcp_pm_del_add_timer(msk, addr, false); if (entry) { list_del(&entry->list); kfree(entry); return true; } return false; } static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk, const struct mptcp_addr_info *addr, bool force) { struct mptcp_rm_list list = { .nr = 0 }; bool ret; list.ids[list.nr++] = addr->id; ret = remove_anno_list_by_saddr(msk, addr); if (ret || force) { spin_lock_bh(&msk->pm.lock); mptcp_pm_remove_addr(msk, &list); spin_unlock_bh(&msk->pm.lock); } return ret; } static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net, const struct mptcp_pm_addr_entry *entry) { const struct mptcp_addr_info *addr = &entry->addr; struct mptcp_rm_list list = { .nr = 0 }; long s_slot = 0, s_num = 0; struct mptcp_sock *msk; pr_debug("remove_id=%d", addr->id); list.ids[list.nr++] = addr->id; while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { struct sock *sk = (struct sock *)msk; bool remove_subflow; if (mptcp_pm_is_userspace(msk)) goto next; if (list_empty(&msk->conn_list)) { mptcp_pm_remove_anno_addr(msk, addr, false); goto next; } lock_sock(sk); remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr); mptcp_pm_remove_anno_addr(msk, addr, remove_subflow && !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)); if (remove_subflow) mptcp_pm_remove_subflow(msk, &list); release_sock(sk); next: sock_put(sk); cond_resched(); } return 0; } static int mptcp_nl_remove_id_zero_address(struct net *net, struct mptcp_addr_info *addr) { struct mptcp_rm_list list = { .nr = 0 }; long s_slot = 0, s_num = 0; struct mptcp_sock *msk; list.ids[list.nr++] = 0; while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { struct sock *sk = (struct sock *)msk; struct mptcp_addr_info msk_local; if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk)) goto next; local_address((struct sock_common *)msk, &msk_local); if (!mptcp_addresses_equal(&msk_local, addr, addr->port)) goto next; lock_sock(sk); spin_lock_bh(&msk->pm.lock); mptcp_pm_remove_addr(msk, &list); mptcp_pm_nl_rm_subflow_received(msk, &list); spin_unlock_bh(&msk->pm.lock); release_sock(sk); next: sock_put(sk); cond_resched(); } return 0; } static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info) { struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; struct pm_nl_pernet *pernet = genl_info_pm_nl(info); struct mptcp_pm_addr_entry addr, *entry; unsigned int addr_max; int ret; ret = mptcp_pm_parse_entry(attr, info, false, &addr); if (ret < 0) return ret; /* the zero id address is special: the first address used by the msk * always gets such an id, so different subflows can have different zero * id addresses. Additionally zero id is not accounted for in id_bitmap. * Let's use an 'mptcp_rm_list' instead of the common remove code. */ if (addr.addr.id == 0) return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr); spin_lock_bh(&pernet->lock); entry = __lookup_addr_by_id(pernet, addr.addr.id); if (!entry) { GENL_SET_ERR_MSG(info, "address not found"); spin_unlock_bh(&pernet->lock); return -EINVAL; } if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) { addr_max = pernet->add_addr_signal_max; WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1); } if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) { addr_max = pernet->local_addr_max; WRITE_ONCE(pernet->local_addr_max, addr_max - 1); } pernet->addrs--; list_del_rcu(&entry->list); __clear_bit(entry->addr.id, pernet->id_bitmap); spin_unlock_bh(&pernet->lock); mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), entry); synchronize_rcu(); __mptcp_pm_release_addr_entry(entry); return ret; } void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk, struct list_head *rm_list) { struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 }; struct mptcp_pm_addr_entry *entry; list_for_each_entry(entry, rm_list, list) { if (lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) && slist.nr < MPTCP_RM_IDS_MAX) slist.ids[slist.nr++] = entry->addr.id; if (remove_anno_list_by_saddr(msk, &entry->addr) && alist.nr < MPTCP_RM_IDS_MAX) alist.ids[alist.nr++] = entry->addr.id; } if (alist.nr) { spin_lock_bh(&msk->pm.lock); mptcp_pm_remove_addr(msk, &alist); spin_unlock_bh(&msk->pm.lock); } if (slist.nr) mptcp_pm_remove_subflow(msk, &slist); } static void mptcp_nl_remove_addrs_list(struct net *net, struct list_head *rm_list) { long s_slot = 0, s_num = 0; struct mptcp_sock *msk; if (list_empty(rm_list)) return; while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { struct sock *sk = (struct sock *)msk; if (!mptcp_pm_is_userspace(msk)) { lock_sock(sk); mptcp_pm_remove_addrs_and_subflows(msk, rm_list); release_sock(sk); } sock_put(sk); cond_resched(); } } /* caller must ensure the RCU grace period is already elapsed */ static void __flush_addrs(struct list_head *list) { while (!list_empty(list)) { struct mptcp_pm_addr_entry *cur; cur = list_entry(list->next, struct mptcp_pm_addr_entry, list); list_del_rcu(&cur->list); __mptcp_pm_release_addr_entry(cur); } } static void __reset_counters(struct pm_nl_pernet *pernet) { WRITE_ONCE(pernet->add_addr_signal_max, 0); WRITE_ONCE(pernet->add_addr_accept_max, 0); WRITE_ONCE(pernet->local_addr_max, 0); pernet->addrs = 0; } static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info) { struct pm_nl_pernet *pernet = genl_info_pm_nl(info); LIST_HEAD(free_list); spin_lock_bh(&pernet->lock); list_splice_init(&pernet->local_addr_list, &free_list); __reset_counters(pernet); pernet->next_id = 1; bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); spin_unlock_bh(&pernet->lock); mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list); synchronize_rcu(); __flush_addrs(&free_list); return 0; } static int mptcp_nl_fill_addr(struct sk_buff *skb, struct mptcp_pm_addr_entry *entry) { struct mptcp_addr_info *addr = &entry->addr; struct nlattr *attr; attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR); if (!attr) return -EMSGSIZE; if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family)) goto nla_put_failure; if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port))) goto nla_put_failure; if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id)) goto nla_put_failure; if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags)) goto nla_put_failure; if (entry->ifindex && nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex)) goto nla_put_failure; if (addr->family == AF_INET && nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4, addr->addr.s_addr)) goto nla_put_failure; #if IS_ENABLED(CONFIG_MPTCP_IPV6) else if (addr->family == AF_INET6 && nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6)) goto nla_put_failure; #endif nla_nest_end(skb, attr); return 0; nla_put_failure: nla_nest_cancel(skb, attr); return -EMSGSIZE; } static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info) { struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; struct pm_nl_pernet *pernet = genl_info_pm_nl(info); struct mptcp_pm_addr_entry addr, *entry; struct sk_buff *msg; void *reply; int ret; ret = mptcp_pm_parse_entry(attr, info, false, &addr); if (ret < 0) return ret; msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) return -ENOMEM; reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0, info->genlhdr->cmd); if (!reply) { GENL_SET_ERR_MSG(info, "not enough space in Netlink message"); ret = -EMSGSIZE; goto fail; } spin_lock_bh(&pernet->lock); entry = __lookup_addr_by_id(pernet, addr.addr.id); if (!entry) { GENL_SET_ERR_MSG(info, "address not found"); ret = -EINVAL; goto unlock_fail; } ret = mptcp_nl_fill_addr(msg, entry); if (ret) goto unlock_fail; genlmsg_end(msg, reply); ret = genlmsg_reply(msg, info); spin_unlock_bh(&pernet->lock); return ret; unlock_fail: spin_unlock_bh(&pernet->lock); fail: nlmsg_free(msg); return ret; } static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg, struct netlink_callback *cb) { struct net *net = sock_net(msg->sk); struct mptcp_pm_addr_entry *entry; struct pm_nl_pernet *pernet; int id = cb->args[0]; void *hdr; int i; pernet = pm_nl_get_pernet(net); spin_lock_bh(&pernet->lock); for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) { if (test_bit(i, pernet->id_bitmap)) { entry = __lookup_addr_by_id(pernet, i); if (!entry) break; if (entry->addr.id <= id) continue; hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, &mptcp_genl_family, NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR); if (!hdr) break; if (mptcp_nl_fill_addr(msg, entry) < 0) { genlmsg_cancel(msg, hdr); break; } id = entry->addr.id; genlmsg_end(msg, hdr); } } spin_unlock_bh(&pernet->lock); cb->args[0] = id; return msg->len; } static int parse_limit(struct genl_info *info, int id, unsigned int *limit) { struct nlattr *attr = info->attrs[id]; if (!attr) return 0; *limit = nla_get_u32(attr); if (*limit > MPTCP_PM_ADDR_MAX) { GENL_SET_ERR_MSG(info, "limit greater than maximum"); return -EINVAL; } return 0; } static int mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info) { struct pm_nl_pernet *pernet = genl_info_pm_nl(info); unsigned int rcv_addrs, subflows; int ret; spin_lock_bh(&pernet->lock); rcv_addrs = pernet->add_addr_accept_max; ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs); if (ret) goto unlock; subflows = pernet->subflows_max; ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows); if (ret) goto unlock; WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs); WRITE_ONCE(pernet->subflows_max, subflows); unlock: spin_unlock_bh(&pernet->lock); return ret; } static int mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info) { struct pm_nl_pernet *pernet = genl_info_pm_nl(info); struct sk_buff *msg; void *reply; msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) return -ENOMEM; reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0, MPTCP_PM_CMD_GET_LIMITS); if (!reply) goto fail; if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS, READ_ONCE(pernet->add_addr_accept_max))) goto fail; if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS, READ_ONCE(pernet->subflows_max))) goto fail; genlmsg_end(msg, reply); return genlmsg_reply(msg, info); fail: GENL_SET_ERR_MSG(info, "not enough space in Netlink message"); nlmsg_free(msg); return -EMSGSIZE; } static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk, struct mptcp_addr_info *addr) { struct mptcp_rm_list list = { .nr = 0 }; list.ids[list.nr++] = addr->id; spin_lock_bh(&msk->pm.lock); mptcp_pm_nl_rm_subflow_received(msk, &list); mptcp_pm_create_subflow_or_signal_addr(msk); spin_unlock_bh(&msk->pm.lock); } static int mptcp_nl_set_flags(struct net *net, struct mptcp_addr_info *addr, u8 bkup, u8 changed) { long s_slot = 0, s_num = 0; struct mptcp_sock *msk; int ret = -EINVAL; while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { struct sock *sk = (struct sock *)msk; if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk)) goto next; lock_sock(sk); if (changed & MPTCP_PM_ADDR_FLAG_BACKUP) ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup); if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH) mptcp_pm_nl_fullmesh(msk, addr); release_sock(sk); next: sock_put(sk); cond_resched(); } return ret; } static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info) { struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, }, *entry; struct mptcp_pm_addr_entry remote = { .addr = { .family = AF_UNSPEC }, }; struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE]; struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN]; struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; struct pm_nl_pernet *pernet = genl_info_pm_nl(info); u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP | MPTCP_PM_ADDR_FLAG_FULLMESH; struct net *net = sock_net(skb->sk); u8 bkup = 0, lookup_by_id = 0; int ret; ret = mptcp_pm_parse_entry(attr, info, false, &addr); if (ret < 0) return ret; if (attr_rem) { ret = mptcp_pm_parse_entry(attr_rem, info, false, &remote); if (ret < 0) return ret; } if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP) bkup = 1; if (addr.addr.family == AF_UNSPEC) { lookup_by_id = 1; if (!addr.addr.id) return -EOPNOTSUPP; } if (token) return mptcp_userspace_pm_set_flags(sock_net(skb->sk), token, &addr, &remote, bkup); spin_lock_bh(&pernet->lock); entry = __lookup_addr(pernet, &addr.addr, lookup_by_id); if (!entry) { spin_unlock_bh(&pernet->lock); return -EINVAL; } if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) && (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) { spin_unlock_bh(&pernet->lock); return -EINVAL; } changed = (addr.flags ^ entry->flags) & mask; entry->flags = (entry->flags & ~mask) | (addr.flags & mask); addr = *entry; spin_unlock_bh(&pernet->lock); mptcp_nl_set_flags(net, &addr.addr, bkup, changed); return 0; } static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp) { genlmsg_multicast_netns(&mptcp_genl_family, net, nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp); } bool mptcp_userspace_pm_active(const struct mptcp_sock *msk) { return genl_has_listeners(&mptcp_genl_family, sock_net((const struct sock *)msk), MPTCP_PM_EV_GRP_OFFSET); } static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk) { const struct inet_sock *issk = inet_sk(ssk); const struct mptcp_subflow_context *sf; if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family)) return -EMSGSIZE; switch (ssk->sk_family) { case AF_INET: if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr)) return -EMSGSIZE; if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr)) return -EMSGSIZE; break; #if IS_ENABLED(CONFIG_MPTCP_IPV6) case AF_INET6: { const struct ipv6_pinfo *np = inet6_sk(ssk); if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr)) return -EMSGSIZE; if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr)) return -EMSGSIZE; break; } #endif default: WARN_ON_ONCE(1); return -EMSGSIZE; } if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport)) return -EMSGSIZE; if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport)) return -EMSGSIZE; sf = mptcp_subflow_ctx(ssk); if (WARN_ON_ONCE(!sf)) return -EINVAL; if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, sf->local_id)) return -EMSGSIZE; if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id)) return -EMSGSIZE; return 0; } static int mptcp_event_put_token_and_ssk(struct sk_buff *skb, const struct mptcp_sock *msk, const struct sock *ssk) { const struct sock *sk = (const struct sock *)msk; const struct mptcp_subflow_context *sf; u8 sk_err; if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token)) return -EMSGSIZE; if (mptcp_event_add_subflow(skb, ssk)) return -EMSGSIZE; sf = mptcp_subflow_ctx(ssk); if (WARN_ON_ONCE(!sf)) return -EINVAL; if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup)) return -EMSGSIZE; if (ssk->sk_bound_dev_if && nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if)) return -EMSGSIZE; sk_err = ssk->sk_err; if (sk_err && sk->sk_state == TCP_ESTABLISHED && nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err)) return -EMSGSIZE; return 0; } static int mptcp_event_sub_established(struct sk_buff *skb, const struct mptcp_sock *msk, const struct sock *ssk) { return mptcp_event_put_token_and_ssk(skb, msk, ssk); } static int mptcp_event_sub_closed(struct sk_buff *skb, const struct mptcp_sock *msk, const struct sock *ssk) { const struct mptcp_subflow_context *sf; if (mptcp_event_put_token_and_ssk(skb, msk, ssk)) return -EMSGSIZE; sf = mptcp_subflow_ctx(ssk); if (!sf->reset_seen) return 0; if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason)) return -EMSGSIZE; if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient)) return -EMSGSIZE; return 0; } static int mptcp_event_created(struct sk_buff *skb, const struct mptcp_sock *msk, const struct sock *ssk) { int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token); if (err) return err; if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side))) return -EMSGSIZE; return mptcp_event_add_subflow(skb, ssk); } void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id) { struct net *net = sock_net((const struct sock *)msk); struct nlmsghdr *nlh; struct sk_buff *skb; if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET)) return; skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); if (!skb) return; nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED); if (!nlh) goto nla_put_failure; if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token)) goto nla_put_failure; if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id)) goto nla_put_failure; genlmsg_end(skb, nlh); mptcp_nl_mcast_send(net, skb, GFP_ATOMIC); return; nla_put_failure: kfree_skb(skb); } void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); struct mptcp_sock *msk = mptcp_sk(subflow->conn); struct net *net = sock_net(ssk); struct nlmsghdr *nlh; struct sk_buff *skb; if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET)) return; skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); if (!skb) return; nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_ANNOUNCED); if (!nlh) goto nla_put_failure; if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token)) goto nla_put_failure; if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id)) goto nla_put_failure; if (nla_put_be16(skb, MPTCP_ATTR_DPORT, info->port == 0 ? inet_sk(ssk)->inet_dport : info->port)) goto nla_put_failure; switch (info->family) { case AF_INET: if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr)) goto nla_put_failure; break; #if IS_ENABLED(CONFIG_MPTCP_IPV6) case AF_INET6: if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6)) goto nla_put_failure; break; #endif default: WARN_ON_ONCE(1); goto nla_put_failure; } genlmsg_end(skb, nlh); mptcp_nl_mcast_send(net, skb, GFP_ATOMIC); return; nla_put_failure: kfree_skb(skb); } void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp) { struct net *net = sock_net((const struct sock *)msk); struct nlmsghdr *nlh; struct sk_buff *skb; if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET)) return; skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp); if (!skb) return; nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type); if (!nlh) goto nla_put_failure; switch (type) { case MPTCP_EVENT_UNSPEC: WARN_ON_ONCE(1); break; case MPTCP_EVENT_CREATED: case MPTCP_EVENT_ESTABLISHED: if (mptcp_event_created(skb, msk, ssk) < 0) goto nla_put_failure; break; case MPTCP_EVENT_CLOSED: if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token) < 0) goto nla_put_failure; break; case MPTCP_EVENT_ANNOUNCED: case MPTCP_EVENT_REMOVED: /* call mptcp_event_addr_announced()/removed instead */ WARN_ON_ONCE(1); break; case MPTCP_EVENT_SUB_ESTABLISHED: case MPTCP_EVENT_SUB_PRIORITY: if (mptcp_event_sub_established(skb, msk, ssk) < 0) goto nla_put_failure; break; case MPTCP_EVENT_SUB_CLOSED: if (mptcp_event_sub_closed(skb, msk, ssk) < 0) goto nla_put_failure; break; } genlmsg_end(skb, nlh); mptcp_nl_mcast_send(net, skb, gfp); return; nla_put_failure: kfree_skb(skb); } static const struct genl_small_ops mptcp_pm_ops[] = { { .cmd = MPTCP_PM_CMD_ADD_ADDR, .doit = mptcp_nl_cmd_add_addr, .flags = GENL_UNS_ADMIN_PERM, }, { .cmd = MPTCP_PM_CMD_DEL_ADDR, .doit = mptcp_nl_cmd_del_addr, .flags = GENL_UNS_ADMIN_PERM, }, { .cmd = MPTCP_PM_CMD_FLUSH_ADDRS, .doit = mptcp_nl_cmd_flush_addrs, .flags = GENL_UNS_ADMIN_PERM, }, { .cmd = MPTCP_PM_CMD_GET_ADDR, .doit = mptcp_nl_cmd_get_addr, .dumpit = mptcp_nl_cmd_dump_addrs, }, { .cmd = MPTCP_PM_CMD_SET_LIMITS, .doit = mptcp_nl_cmd_set_limits, .flags = GENL_UNS_ADMIN_PERM, }, { .cmd = MPTCP_PM_CMD_GET_LIMITS, .doit = mptcp_nl_cmd_get_limits, }, { .cmd = MPTCP_PM_CMD_SET_FLAGS, .doit = mptcp_nl_cmd_set_flags, .flags = GENL_UNS_ADMIN_PERM, }, { .cmd = MPTCP_PM_CMD_ANNOUNCE, .doit = mptcp_nl_cmd_announce, .flags = GENL_UNS_ADMIN_PERM, }, { .cmd = MPTCP_PM_CMD_REMOVE, .doit = mptcp_nl_cmd_remove, .flags = GENL_UNS_ADMIN_PERM, }, { .cmd = MPTCP_PM_CMD_SUBFLOW_CREATE, .doit = mptcp_nl_cmd_sf_create, .flags = GENL_UNS_ADMIN_PERM, }, { .cmd = MPTCP_PM_CMD_SUBFLOW_DESTROY, .doit = mptcp_nl_cmd_sf_destroy, .flags = GENL_UNS_ADMIN_PERM, }, }; static struct genl_family mptcp_genl_family __ro_after_init = { .name = MPTCP_PM_NAME, .version = MPTCP_PM_VER, .maxattr = MPTCP_PM_ATTR_MAX, .policy = mptcp_pm_policy, .netnsok = true, .module = THIS_MODULE, .small_ops = mptcp_pm_ops, .n_small_ops = ARRAY_SIZE(mptcp_pm_ops), .resv_start_op = MPTCP_PM_CMD_SUBFLOW_DESTROY + 1, .mcgrps = mptcp_pm_mcgrps, .n_mcgrps = ARRAY_SIZE(mptcp_pm_mcgrps), }; static int __net_init pm_nl_init_net(struct net *net) { struct pm_nl_pernet *pernet = pm_nl_get_pernet(net); INIT_LIST_HEAD_RCU(&pernet->local_addr_list); /* Cit. 2 subflows ought to be enough for anybody. */ pernet->subflows_max = 2; pernet->next_id = 1; pernet->stale_loss_cnt = 4; spin_lock_init(&pernet->lock); /* No need to initialize other pernet fields, the struct is zeroed at * allocation time. */ return 0; } static void __net_exit pm_nl_exit_net(struct list_head *net_list) { struct net *net; list_for_each_entry(net, net_list, exit_list) { struct pm_nl_pernet *pernet = pm_nl_get_pernet(net); /* net is removed from namespace list, can't race with * other modifiers, also netns core already waited for a * RCU grace period. */ __flush_addrs(&pernet->local_addr_list); } } static struct pernet_operations mptcp_pm_pernet_ops = { .init = pm_nl_init_net, .exit_batch = pm_nl_exit_net, .id = &pm_nl_pernet_id, .size = sizeof(struct pm_nl_pernet), }; void __init mptcp_pm_nl_init(void) { if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0) panic("Failed to register MPTCP PM pernet subsystem.\n"); if (genl_register_family(&mptcp_genl_family)) panic("Failed to register MPTCP PM netlink family\n"); }