diff options
Diffstat (limited to 'net/mptcp/protocol.c')
| -rw-r--r-- | net/mptcp/protocol.c | 3829 |
1 files changed, 3269 insertions, 560 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 3c19a8efdcea..b6dc6e260334 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -16,13 +16,18 @@ #include <net/inet_hashtables.h> #include <net/protocol.h> #include <net/tcp.h> +#include <net/tcp_states.h> #if IS_ENABLED(CONFIG_MPTCP_IPV6) #include <net/transp_v6.h> #endif #include <net/mptcp.h> +#include <net/xfrm.h> +#include <asm/ioctls.h> #include "protocol.h" +#include "mib.h" -#define MPTCP_SAME_STATE TCP_MAX_STATES +#define CREATE_TRACE_POINTS +#include <trace/events/mptcp.h> #if IS_ENABLED(CONFIG_MPTCP_IPV6) struct mptcp6_sock { @@ -31,11 +36,33 @@ struct mptcp6_sock { }; #endif +struct mptcp_skb_cb { + u64 map_seq; + u64 end_seq; + u32 offset; + u8 has_rxtstamp:1; +}; + +#define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0])) + +enum { + MPTCP_CMSG_TS = BIT(0), + MPTCP_CMSG_INQ = BIT(1), +}; + +static struct percpu_counter mptcp_sockets_allocated ____cacheline_aligned_in_smp; + +static void __mptcp_destroy_sock(struct sock *sk); +static void __mptcp_check_send_data_fin(struct sock *sk); + +DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions); +static struct net_device mptcp_napi_dev; + /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not * completed yet or has failed, return the subflow socket. * Otherwise return NULL. */ -static struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk) +struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk) { if (!msk->subflow || READ_ONCE(msk->can_ack)) return NULL; @@ -43,80 +70,863 @@ static struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk) return msk->subflow; } -static bool __mptcp_needs_tcp_fallback(const struct mptcp_sock *msk) +/* Returns end sequence number of the receiver's advertised window */ +static u64 mptcp_wnd_end(const struct mptcp_sock *msk) { - return msk->first && !sk_is_mptcp(msk->first); + return READ_ONCE(msk->wnd_end); } -static struct socket *__mptcp_tcp_fallback(struct mptcp_sock *msk) +static bool mptcp_is_tcpsk(struct sock *sk) { - sock_owned_by_me((const struct sock *)msk); - - if (likely(!__mptcp_needs_tcp_fallback(msk))) - return NULL; + struct socket *sock = sk->sk_socket; - if (msk->subflow) { - release_sock((struct sock *)msk); - return msk->subflow; + if (unlikely(sk->sk_prot == &tcp_prot)) { + /* we are being invoked after mptcp_accept() has + * accepted a non-mp-capable flow: sk is a tcp_sk, + * not an mptcp one. + * + * Hand the socket over to tcp so all further socket ops + * bypass mptcp. + */ + sock->ops = &inet_stream_ops; + return true; +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + } else if (unlikely(sk->sk_prot == &tcpv6_prot)) { + sock->ops = &inet6_stream_ops; + return true; +#endif } - return NULL; -} - -static bool __mptcp_can_create_subflow(const struct mptcp_sock *msk) -{ - return !msk->first; + return false; } -static struct socket *__mptcp_socket_create(struct mptcp_sock *msk, int state) +static int __mptcp_socket_create(struct mptcp_sock *msk) { struct mptcp_subflow_context *subflow; struct sock *sk = (struct sock *)msk; struct socket *ssock; int err; - ssock = __mptcp_nmpc_socket(msk); - if (ssock) - goto set_state; - - if (!__mptcp_can_create_subflow(msk)) - return ERR_PTR(-EINVAL); - err = mptcp_subflow_create_socket(sk, &ssock); if (err) - return ERR_PTR(err); + return err; msk->first = ssock->sk; msk->subflow = ssock; subflow = mptcp_subflow_ctx(ssock->sk); list_add(&subflow->node, &msk->conn_list); + sock_hold(ssock->sk); subflow->request_mptcp = 1; -set_state: - if (state != MPTCP_SAME_STATE) - inet_sk_state_store(sk, state); - return ssock; + /* This is the first subflow, always with id 0 */ + subflow->local_id_valid = 1; + mptcp_sock_graft(msk->first, sk->sk_socket); + + return 0; +} + +static void mptcp_drop(struct sock *sk, struct sk_buff *skb) +{ + sk_drops_add(sk, skb); + __kfree_skb(skb); +} + +static void mptcp_rmem_charge(struct sock *sk, int size) +{ + mptcp_sk(sk)->rmem_fwd_alloc -= size; +} + +static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to, + struct sk_buff *from) +{ + bool fragstolen; + int delta; + + if (MPTCP_SKB_CB(from)->offset || + !skb_try_coalesce(to, from, &fragstolen, &delta)) + return false; + + pr_debug("colesced seq %llx into %llx new len %d new end seq %llx", + MPTCP_SKB_CB(from)->map_seq, MPTCP_SKB_CB(to)->map_seq, + to->len, MPTCP_SKB_CB(from)->end_seq); + MPTCP_SKB_CB(to)->end_seq = MPTCP_SKB_CB(from)->end_seq; + + /* note the fwd memory can reach a negative value after accounting + * for the delta, but the later skb free will restore a non + * negative one + */ + atomic_add(delta, &sk->sk_rmem_alloc); + mptcp_rmem_charge(sk, delta); + kfree_skb_partial(from, fragstolen); + + return true; +} + +static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to, + struct sk_buff *from) +{ + if (MPTCP_SKB_CB(from)->map_seq != MPTCP_SKB_CB(to)->end_seq) + return false; + + return mptcp_try_coalesce((struct sock *)msk, to, from); +} + +static void __mptcp_rmem_reclaim(struct sock *sk, int amount) +{ + amount >>= PAGE_SHIFT; + mptcp_sk(sk)->rmem_fwd_alloc -= amount << PAGE_SHIFT; + __sk_mem_reduce_allocated(sk, amount); +} + +static void mptcp_rmem_uncharge(struct sock *sk, int size) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + int reclaimable; + + msk->rmem_fwd_alloc += size; + reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk); + + /* see sk_mem_uncharge() for the rationale behind the following schema */ + if (unlikely(reclaimable >= PAGE_SIZE)) + __mptcp_rmem_reclaim(sk, reclaimable); +} + +static void mptcp_rfree(struct sk_buff *skb) +{ + unsigned int len = skb->truesize; + struct sock *sk = skb->sk; + + atomic_sub(len, &sk->sk_rmem_alloc); + mptcp_rmem_uncharge(sk, len); +} + +static void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk) +{ + skb_orphan(skb); + skb->sk = sk; + skb->destructor = mptcp_rfree; + atomic_add(skb->truesize, &sk->sk_rmem_alloc); + mptcp_rmem_charge(sk, skb->truesize); +} + +/* "inspired" by tcp_data_queue_ofo(), main differences: + * - use mptcp seqs + * - don't cope with sacks + */ +static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb) +{ + struct sock *sk = (struct sock *)msk; + struct rb_node **p, *parent; + u64 seq, end_seq, max_seq; + struct sk_buff *skb1; + + seq = MPTCP_SKB_CB(skb)->map_seq; + end_seq = MPTCP_SKB_CB(skb)->end_seq; + max_seq = atomic64_read(&msk->rcv_wnd_sent); + + pr_debug("msk=%p seq=%llx limit=%llx empty=%d", msk, seq, max_seq, + RB_EMPTY_ROOT(&msk->out_of_order_queue)); + if (after64(end_seq, max_seq)) { + /* out of window */ + mptcp_drop(sk, skb); + pr_debug("oow by %lld, rcv_wnd_sent %llu\n", + (unsigned long long)end_seq - (unsigned long)max_seq, + (unsigned long long)atomic64_read(&msk->rcv_wnd_sent)); + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_NODSSWINDOW); + return; + } + + p = &msk->out_of_order_queue.rb_node; + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUE); + if (RB_EMPTY_ROOT(&msk->out_of_order_queue)) { + rb_link_node(&skb->rbnode, NULL, p); + rb_insert_color(&skb->rbnode, &msk->out_of_order_queue); + msk->ooo_last_skb = skb; + goto end; + } + + /* with 2 subflows, adding at end of ooo queue is quite likely + * Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup. + */ + if (mptcp_ooo_try_coalesce(msk, msk->ooo_last_skb, skb)) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE); + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL); + return; + } + + /* Can avoid an rbtree lookup if we are adding skb after ooo_last_skb */ + if (!before64(seq, MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq)) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL); + parent = &msk->ooo_last_skb->rbnode; + p = &parent->rb_right; + goto insert; + } + + /* Find place to insert this segment. Handle overlaps on the way. */ + parent = NULL; + while (*p) { + parent = *p; + skb1 = rb_to_skb(parent); + if (before64(seq, MPTCP_SKB_CB(skb1)->map_seq)) { + p = &parent->rb_left; + continue; + } + if (before64(seq, MPTCP_SKB_CB(skb1)->end_seq)) { + if (!after64(end_seq, MPTCP_SKB_CB(skb1)->end_seq)) { + /* All the bits are present. Drop. */ + mptcp_drop(sk, skb); + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); + return; + } + if (after64(seq, MPTCP_SKB_CB(skb1)->map_seq)) { + /* partial overlap: + * | skb | + * | skb1 | + * continue traversing + */ + } else { + /* skb's seq == skb1's seq and skb covers skb1. + * Replace skb1 with skb. + */ + rb_replace_node(&skb1->rbnode, &skb->rbnode, + &msk->out_of_order_queue); + mptcp_drop(sk, skb1); + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); + goto merge_right; + } + } else if (mptcp_ooo_try_coalesce(msk, skb1, skb)) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE); + return; + } + p = &parent->rb_right; + } + +insert: + /* Insert segment into RB tree. */ + rb_link_node(&skb->rbnode, parent, p); + rb_insert_color(&skb->rbnode, &msk->out_of_order_queue); + +merge_right: + /* Remove other segments covered by skb. */ + while ((skb1 = skb_rb_next(skb)) != NULL) { + if (before64(end_seq, MPTCP_SKB_CB(skb1)->end_seq)) + break; + rb_erase(&skb1->rbnode, &msk->out_of_order_queue); + mptcp_drop(sk, skb1); + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); + } + /* If there is no skb after us, we are the last_skb ! */ + if (!skb1) + msk->ooo_last_skb = skb; + +end: + skb_condense(skb); + mptcp_set_owner_r(skb, sk); +} + +static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + int amt, amount; + + if (size <= msk->rmem_fwd_alloc) + return true; + + size -= msk->rmem_fwd_alloc; + amt = sk_mem_pages(size); + amount = amt << PAGE_SHIFT; + if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV)) + return false; + + msk->rmem_fwd_alloc += amount; + return true; +} + +static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, + struct sk_buff *skb, unsigned int offset, + size_t copy_len) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct sock *sk = (struct sock *)msk; + struct sk_buff *tail; + bool has_rxtstamp; + + __skb_unlink(skb, &ssk->sk_receive_queue); + + skb_ext_reset(skb); + skb_orphan(skb); + + /* try to fetch required memory from subflow */ + if (!mptcp_rmem_schedule(sk, ssk, skb->truesize)) + goto drop; + + has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp; + + /* the skb map_seq accounts for the skb offset: + * mptcp_subflow_get_mapped_dsn() is based on the current tp->copied_seq + * value + */ + MPTCP_SKB_CB(skb)->map_seq = mptcp_subflow_get_mapped_dsn(subflow); + MPTCP_SKB_CB(skb)->end_seq = MPTCP_SKB_CB(skb)->map_seq + copy_len; + MPTCP_SKB_CB(skb)->offset = offset; + MPTCP_SKB_CB(skb)->has_rxtstamp = has_rxtstamp; + + if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) { + /* in sequence */ + WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len); + tail = skb_peek_tail(&sk->sk_receive_queue); + if (tail && mptcp_try_coalesce(sk, tail, skb)) + return true; + + mptcp_set_owner_r(skb, sk); + __skb_queue_tail(&sk->sk_receive_queue, skb); + return true; + } else if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) { + mptcp_data_queue_ofo(msk, skb); + return false; + } + + /* old data, keep it simple and drop the whole pkt, sender + * will retransmit as needed, if needed. + */ + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); +drop: + mptcp_drop(sk, skb); + return false; } -static struct sock *mptcp_subflow_get(const struct mptcp_sock *msk) +static void mptcp_stop_timer(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + sk_stop_timer(sk, &icsk->icsk_retransmit_timer); + mptcp_sk(sk)->timer_ival = 0; +} + +static void mptcp_close_wake_up(struct sock *sk) +{ + if (sock_flag(sk, SOCK_DEAD)) + return; + + sk->sk_state_change(sk); + if (sk->sk_shutdown == SHUTDOWN_MASK || + sk->sk_state == TCP_CLOSE) + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); + else + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); +} + +static bool mptcp_pending_data_fin_ack(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + return !__mptcp_check_fallback(msk) && + ((1 << sk->sk_state) & + (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK)) && + msk->write_seq == READ_ONCE(msk->snd_una); +} + +static void mptcp_check_data_fin_ack(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + /* Look for an acknowledged DATA_FIN */ + if (mptcp_pending_data_fin_ack(sk)) { + WRITE_ONCE(msk->snd_data_fin_enable, 0); + + switch (sk->sk_state) { + case TCP_FIN_WAIT1: + inet_sk_state_store(sk, TCP_FIN_WAIT2); + break; + case TCP_CLOSING: + case TCP_LAST_ACK: + inet_sk_state_store(sk, TCP_CLOSE); + break; + } + + mptcp_close_wake_up(sk); + } +} + +static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + if (READ_ONCE(msk->rcv_data_fin) && + ((1 << sk->sk_state) & + (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2))) { + u64 rcv_data_fin_seq = READ_ONCE(msk->rcv_data_fin_seq); + + if (msk->ack_seq == rcv_data_fin_seq) { + if (seq) + *seq = rcv_data_fin_seq; + + return true; + } + } + + return false; +} + +static void mptcp_set_datafin_timeout(const struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + u32 retransmits; + + retransmits = min_t(u32, icsk->icsk_retransmits, + ilog2(TCP_RTO_MAX / TCP_RTO_MIN)); + + mptcp_sk(sk)->timer_ival = TCP_RTO_MIN << retransmits; +} + +static void __mptcp_set_timeout(struct sock *sk, long tout) +{ + mptcp_sk(sk)->timer_ival = tout > 0 ? tout : TCP_RTO_MIN; +} + +static long mptcp_timeout_from_subflow(const struct mptcp_subflow_context *subflow) +{ + const struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + return inet_csk(ssk)->icsk_pending && !subflow->stale_count ? + inet_csk(ssk)->icsk_timeout - jiffies : 0; +} + +static void mptcp_set_timeout(struct sock *sk) { struct mptcp_subflow_context *subflow; + long tout = 0; - sock_owned_by_me((const struct sock *)msk); + mptcp_for_each_subflow(mptcp_sk(sk), subflow) + tout = max(tout, mptcp_timeout_from_subflow(subflow)); + __mptcp_set_timeout(sk, tout); +} + +static inline bool tcp_can_send_ack(const struct sock *ssk) +{ + return !((1 << inet_sk_state_load(ssk)) & + (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN)); +} + +void __mptcp_subflow_send_ack(struct sock *ssk) +{ + if (tcp_can_send_ack(ssk)) + tcp_send_ack(ssk); +} + +static void mptcp_subflow_send_ack(struct sock *ssk) +{ + bool slow; + + slow = lock_sock_fast(ssk); + __mptcp_subflow_send_ack(ssk); + unlock_sock_fast(ssk, slow); +} + +static void mptcp_send_ack(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow; + + mptcp_for_each_subflow(msk, subflow) + mptcp_subflow_send_ack(mptcp_subflow_tcp_sock(subflow)); +} + +static void mptcp_subflow_cleanup_rbuf(struct sock *ssk) +{ + bool slow; + + slow = lock_sock_fast(ssk); + if (tcp_can_send_ack(ssk)) + tcp_cleanup_rbuf(ssk, 1); + unlock_sock_fast(ssk, slow); +} + +static bool mptcp_subflow_could_cleanup(const struct sock *ssk, bool rx_empty) +{ + const struct inet_connection_sock *icsk = inet_csk(ssk); + u8 ack_pending = READ_ONCE(icsk->icsk_ack.pending); + const struct tcp_sock *tp = tcp_sk(ssk); + + return (ack_pending & ICSK_ACK_SCHED) && + ((READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->rcv_wup) > + READ_ONCE(icsk->icsk_ack.rcv_mss)) || + (rx_empty && ack_pending & + (ICSK_ACK_PUSHED2 | ICSK_ACK_PUSHED))); +} + +static void mptcp_cleanup_rbuf(struct mptcp_sock *msk) +{ + int old_space = READ_ONCE(msk->old_wspace); + struct mptcp_subflow_context *subflow; + struct sock *sk = (struct sock *)msk; + int space = __mptcp_space(sk); + bool cleanup, rx_empty; + + cleanup = (space > 0) && (space >= (old_space << 1)); + rx_empty = !__mptcp_rmem(sk); mptcp_for_each_subflow(msk, subflow) { - return mptcp_subflow_tcp_sock(subflow); + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + if (cleanup || mptcp_subflow_could_cleanup(ssk, rx_empty)) + mptcp_subflow_cleanup_rbuf(ssk); } +} - return NULL; +static bool mptcp_check_data_fin(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + u64 rcv_data_fin_seq; + bool ret = false; + + if (__mptcp_check_fallback(msk)) + return ret; + + /* Need to ack a DATA_FIN received from a peer while this side + * of the connection is in ESTABLISHED, FIN_WAIT1, or FIN_WAIT2. + * msk->rcv_data_fin was set when parsing the incoming options + * at the subflow level and the msk lock was not held, so this + * is the first opportunity to act on the DATA_FIN and change + * the msk state. + * + * If we are caught up to the sequence number of the incoming + * DATA_FIN, send the DATA_ACK now and do state transition. If + * not caught up, do nothing and let the recv code send DATA_ACK + * when catching up. + */ + + if (mptcp_pending_data_fin(sk, &rcv_data_fin_seq)) { + WRITE_ONCE(msk->ack_seq, msk->ack_seq + 1); + WRITE_ONCE(msk->rcv_data_fin, 0); + + sk->sk_shutdown |= RCV_SHUTDOWN; + smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ + + switch (sk->sk_state) { + case TCP_ESTABLISHED: + inet_sk_state_store(sk, TCP_CLOSE_WAIT); + break; + case TCP_FIN_WAIT1: + inet_sk_state_store(sk, TCP_CLOSING); + break; + case TCP_FIN_WAIT2: + inet_sk_state_store(sk, TCP_CLOSE); + break; + default: + /* Other states not expected */ + WARN_ON_ONCE(1); + break; + } + + ret = true; + mptcp_send_ack(msk); + mptcp_close_wake_up(sk); + } + return ret; } -static bool mptcp_ext_cache_refill(struct mptcp_sock *msk) +static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk, + struct sock *ssk, + unsigned int *bytes) { - if (!msk->cached_ext) - msk->cached_ext = __skb_ext_alloc(); + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct sock *sk = (struct sock *)msk; + unsigned int moved = 0; + bool more_data_avail; + struct tcp_sock *tp; + bool done = false; + int sk_rbuf; + + sk_rbuf = READ_ONCE(sk->sk_rcvbuf); + + if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) { + int ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf); + + if (unlikely(ssk_rbuf > sk_rbuf)) { + WRITE_ONCE(sk->sk_rcvbuf, ssk_rbuf); + sk_rbuf = ssk_rbuf; + } + } + + pr_debug("msk=%p ssk=%p", msk, ssk); + tp = tcp_sk(ssk); + do { + u32 map_remaining, offset; + u32 seq = tp->copied_seq; + struct sk_buff *skb; + bool fin; + + /* try to move as much data as available */ + map_remaining = subflow->map_data_len - + mptcp_subflow_get_map_offset(subflow); + + skb = skb_peek(&ssk->sk_receive_queue); + if (!skb) { + /* With racing move_skbs_to_msk() and __mptcp_move_skbs(), + * a different CPU can have already processed the pending + * data, stop here or we can enter an infinite loop + */ + if (!moved) + done = true; + break; + } + + if (__mptcp_check_fallback(msk)) { + /* Under fallback skbs have no MPTCP extension and TCP could + * collapse them between the dummy map creation and the + * current dequeue. Be sure to adjust the map size. + */ + map_remaining = skb->len; + subflow->map_data_len = skb->len; + } + + offset = seq - TCP_SKB_CB(skb)->seq; + fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; + if (fin) { + done = true; + seq++; + } + + if (offset < skb->len) { + size_t len = skb->len - offset; - return !!msk->cached_ext; + if (tp->urg_data) + done = true; + + if (__mptcp_move_skb(msk, ssk, skb, offset, len)) + moved += len; + seq += len; + + if (WARN_ON_ONCE(map_remaining < len)) + break; + } else { + WARN_ON_ONCE(!fin); + sk_eat_skb(ssk, skb); + done = true; + } + + WRITE_ONCE(tp->copied_seq, seq); + more_data_avail = mptcp_subflow_data_available(ssk); + + if (atomic_read(&sk->sk_rmem_alloc) > sk_rbuf) { + done = true; + break; + } + } while (more_data_avail); + + *bytes += moved; + return done; +} + +static bool __mptcp_ofo_queue(struct mptcp_sock *msk) +{ + struct sock *sk = (struct sock *)msk; + struct sk_buff *skb, *tail; + bool moved = false; + struct rb_node *p; + u64 end_seq; + + p = rb_first(&msk->out_of_order_queue); + pr_debug("msk=%p empty=%d", msk, RB_EMPTY_ROOT(&msk->out_of_order_queue)); + while (p) { + skb = rb_to_skb(p); + if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) + break; + + p = rb_next(p); + rb_erase(&skb->rbnode, &msk->out_of_order_queue); + + if (unlikely(!after64(MPTCP_SKB_CB(skb)->end_seq, + msk->ack_seq))) { + mptcp_drop(sk, skb); + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); + continue; + } + + end_seq = MPTCP_SKB_CB(skb)->end_seq; + tail = skb_peek_tail(&sk->sk_receive_queue); + if (!tail || !mptcp_ooo_try_coalesce(msk, tail, skb)) { + int delta = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq; + + /* skip overlapping data, if any */ + pr_debug("uncoalesced seq=%llx ack seq=%llx delta=%d", + MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq, + delta); + MPTCP_SKB_CB(skb)->offset += delta; + MPTCP_SKB_CB(skb)->map_seq += delta; + __skb_queue_tail(&sk->sk_receive_queue, skb); + } + msk->ack_seq = end_seq; + moved = true; + } + return moved; +} + +/* In most cases we will be able to lock the mptcp socket. If its already + * owned, we need to defer to the work queue to avoid ABBA deadlock. + */ +static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) +{ + struct sock *sk = (struct sock *)msk; + unsigned int moved = 0; + + __mptcp_move_skbs_from_subflow(msk, ssk, &moved); + __mptcp_ofo_queue(msk); + if (unlikely(ssk->sk_err)) { + if (!sock_owned_by_user(sk)) + __mptcp_error_report(sk); + else + __set_bit(MPTCP_ERROR_REPORT, &msk->cb_flags); + } + + /* If the moves have caught up with the DATA_FIN sequence number + * it's time to ack the DATA_FIN and change socket state, but + * this is not a good place to change state. Let the workqueue + * do it. + */ + if (mptcp_pending_data_fin(sk, NULL)) + mptcp_schedule_work(sk); + return moved > 0; +} + +void mptcp_data_ready(struct sock *sk, struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct mptcp_sock *msk = mptcp_sk(sk); + int sk_rbuf, ssk_rbuf; + + /* The peer can send data while we are shutting down this + * subflow at msk destruction time, but we must avoid enqueuing + * more data to the msk receive queue + */ + if (unlikely(subflow->disposable)) + return; + + ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf); + sk_rbuf = READ_ONCE(sk->sk_rcvbuf); + if (unlikely(ssk_rbuf > sk_rbuf)) + sk_rbuf = ssk_rbuf; + + /* over limit? can't append more skbs to msk, Also, no need to wake-up*/ + if (__mptcp_rmem(sk) > sk_rbuf) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED); + return; + } + + /* Wake-up the reader only for in-sequence data */ + mptcp_data_lock(sk); + if (move_skbs_to_msk(msk, ssk)) + sk->sk_data_ready(sk); + + mptcp_data_unlock(sk); +} + +static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk) +{ + struct sock *sk = (struct sock *)msk; + + if (sk->sk_state != TCP_ESTABLISHED) + return false; + + /* attach to msk socket only after we are sure we will deal with it + * at close time + */ + if (sk->sk_socket && !ssk->sk_socket) + mptcp_sock_graft(ssk, sk->sk_socket); + + mptcp_propagate_sndbuf((struct sock *)msk, ssk); + mptcp_sockopt_sync_locked(msk, ssk); + return true; +} + +static void __mptcp_flush_join_list(struct sock *sk) +{ + struct mptcp_subflow_context *tmp, *subflow; + struct mptcp_sock *msk = mptcp_sk(sk); + + list_for_each_entry_safe(subflow, tmp, &msk->join_list, node) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + bool slow = lock_sock_fast(ssk); + + list_move_tail(&subflow->node, &msk->conn_list); + if (!__mptcp_finish_join(msk, ssk)) + mptcp_subflow_reset(ssk); + unlock_sock_fast(ssk, slow); + } +} + +static bool mptcp_timer_pending(struct sock *sk) +{ + return timer_pending(&inet_csk(sk)->icsk_retransmit_timer); +} + +static void mptcp_reset_timer(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + unsigned long tout; + + /* prevent rescheduling on close */ + if (unlikely(inet_sk_state_load(sk) == TCP_CLOSE)) + return; + + tout = mptcp_sk(sk)->timer_ival; + sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + tout); +} + +bool mptcp_schedule_work(struct sock *sk) +{ + if (inet_sk_state_load(sk) != TCP_CLOSE && + schedule_work(&mptcp_sk(sk)->work)) { + /* each subflow already holds a reference to the sk, and the + * workqueue is invoked by a subflow, so sk can't go away here. + */ + sock_hold(sk); + return true; + } + return false; +} + +void mptcp_subflow_eof(struct sock *sk) +{ + if (!test_and_set_bit(MPTCP_WORK_EOF, &mptcp_sk(sk)->flags)) + mptcp_schedule_work(sk); +} + +static void mptcp_check_for_eof(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow; + struct sock *sk = (struct sock *)msk; + int receivers = 0; + + mptcp_for_each_subflow(msk, subflow) + receivers += !subflow->rx_eof; + if (receivers) + return; + + if (!(sk->sk_shutdown & RCV_SHUTDOWN)) { + /* hopefully temporary hack: propagate shutdown status + * to msk, when all subflows agree on it + */ + sk->sk_shutdown |= RCV_SHUTDOWN; + + smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ + sk->sk_data_ready(sk); + } + + switch (sk->sk_state) { + case TCP_ESTABLISHED: + inet_sk_state_store(sk, TCP_CLOSE_WAIT); + break; + case TCP_FIN_WAIT1: + inet_sk_state_store(sk, TCP_CLOSING); + break; + case TCP_FIN_WAIT2: + inet_sk_state_store(sk, TCP_CLOSE); + break; + default: + return; + } + mptcp_close_wake_up(sk); } static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk) @@ -127,112 +937,409 @@ static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk) sock_owned_by_me(sk); mptcp_for_each_subflow(msk, subflow) { - if (subflow->data_avail) + if (READ_ONCE(subflow->data_avail)) return mptcp_subflow_tcp_sock(subflow); } return NULL; } -static inline bool mptcp_skb_can_collapse_to(const struct mptcp_sock *msk, - const struct sk_buff *skb, - const struct mptcp_ext *mpext) +static bool mptcp_skb_can_collapse_to(u64 write_seq, + const struct sk_buff *skb, + const struct mptcp_ext *mpext) { if (!tcp_skb_can_collapse_to(skb)) return false; - /* can collapse only if MPTCP level sequence is in order */ - return mpext && mpext->data_seq + mpext->data_len == msk->write_seq; + /* can collapse only if MPTCP level sequence is in order and this + * mapping has not been xmitted yet + */ + return mpext && mpext->data_seq + mpext->data_len == write_seq && + !mpext->frozen; } -static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, - struct msghdr *msg, long *timeo, int *pmss_now, - int *ps_goal) +/* we can append data to the given data frag if: + * - there is space available in the backing page_frag + * - the data frag tail matches the current page_frag free offset + * - the data frag end sequence number matches the current write seq + */ +static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk, + const struct page_frag *pfrag, + const struct mptcp_data_frag *df) +{ + return df && pfrag->page == df->page && + pfrag->size - pfrag->offset > 0 && + pfrag->offset == (df->offset + df->data_len) && + df->data_seq + df->data_len == msk->write_seq; +} + +static void dfrag_uncharge(struct sock *sk, int len) +{ + sk_mem_uncharge(sk, len); + sk_wmem_queued_add(sk, -len); +} + +static void dfrag_clear(struct sock *sk, struct mptcp_data_frag *dfrag) +{ + int len = dfrag->data_len + dfrag->overhead; + + list_del(&dfrag->list); + dfrag_uncharge(sk, len); + put_page(dfrag->page); +} + +static void __mptcp_clean_una(struct sock *sk) { - int mss_now, avail_size, size_goal, ret; struct mptcp_sock *msk = mptcp_sk(sk); - struct mptcp_ext *mpext = NULL; - struct sk_buff *skb, *tail; - bool can_collapse = false; - struct page_frag *pfrag; - size_t psize; + struct mptcp_data_frag *dtmp, *dfrag; + u64 snd_una; - /* use the mptcp page cache so that we can easily move the data - * from one substream to another, but do per subflow memory accounting + /* on fallback we just need to ignore snd_una, as this is really + * plain TCP */ - pfrag = sk_page_frag(sk); - while (!sk_page_frag_refill(ssk, pfrag) || - !mptcp_ext_cache_refill(msk)) { - ret = sk_stream_wait_memory(ssk, timeo); - if (ret) - return ret; - if (unlikely(__mptcp_needs_tcp_fallback(msk))) - return 0; + if (__mptcp_check_fallback(msk)) + msk->snd_una = READ_ONCE(msk->snd_nxt); + + snd_una = msk->snd_una; + list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) { + if (after64(dfrag->data_seq + dfrag->data_len, snd_una)) + break; + + if (unlikely(dfrag == msk->first_pending)) { + /* in recovery mode can see ack after the current snd head */ + if (WARN_ON_ONCE(!msk->recovery)) + break; + + WRITE_ONCE(msk->first_pending, mptcp_send_next(sk)); + } + + dfrag_clear(sk, dfrag); } - /* compute copy limit */ - mss_now = tcp_send_mss(ssk, &size_goal, msg->msg_flags); - *pmss_now = mss_now; - *ps_goal = size_goal; - avail_size = size_goal; - skb = tcp_write_queue_tail(ssk); - if (skb) { - mpext = skb_ext_find(skb, SKB_EXT_MPTCP); + dfrag = mptcp_rtx_head(sk); + if (dfrag && after64(snd_una, dfrag->data_seq)) { + u64 delta = snd_una - dfrag->data_seq; + + /* prevent wrap around in recovery mode */ + if (unlikely(delta > dfrag->already_sent)) { + if (WARN_ON_ONCE(!msk->recovery)) + goto out; + if (WARN_ON_ONCE(delta > dfrag->data_len)) + goto out; + dfrag->already_sent += delta - dfrag->already_sent; + } + + dfrag->data_seq += delta; + dfrag->offset += delta; + dfrag->data_len -= delta; + dfrag->already_sent -= delta; + + dfrag_uncharge(sk, delta); + } + + /* all retransmitted data acked, recovery completed */ + if (unlikely(msk->recovery) && after64(msk->snd_una, msk->recovery_snd_nxt)) + msk->recovery = false; + +out: + if (snd_una == READ_ONCE(msk->snd_nxt) && + snd_una == READ_ONCE(msk->write_seq)) { + if (mptcp_timer_pending(sk) && !mptcp_data_fin_enabled(msk)) + mptcp_stop_timer(sk); + } else { + mptcp_reset_timer(sk); + } +} + +static void __mptcp_clean_una_wakeup(struct sock *sk) +{ + lockdep_assert_held_once(&sk->sk_lock.slock); + + __mptcp_clean_una(sk); + mptcp_write_space(sk); +} + +static void mptcp_clean_una_wakeup(struct sock *sk) +{ + mptcp_data_lock(sk); + __mptcp_clean_una_wakeup(sk); + mptcp_data_unlock(sk); +} + +static void mptcp_enter_memory_pressure(struct sock *sk) +{ + struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk = mptcp_sk(sk); + bool first = true; + + sk_stream_moderate_sndbuf(sk); + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + if (first) + tcp_enter_memory_pressure(ssk); + sk_stream_moderate_sndbuf(ssk); + first = false; + } +} + +/* ensure we get enough memory for the frag hdr, beyond some minimal amount of + * data + */ +static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag) +{ + if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag), + pfrag, sk->sk_allocation))) + return true; + + mptcp_enter_memory_pressure(sk); + return false; +} + +static struct mptcp_data_frag * +mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag, + int orig_offset) +{ + int offset = ALIGN(orig_offset, sizeof(long)); + struct mptcp_data_frag *dfrag; + + dfrag = (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset); + dfrag->data_len = 0; + dfrag->data_seq = msk->write_seq; + dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag); + dfrag->offset = offset + sizeof(struct mptcp_data_frag); + dfrag->already_sent = 0; + dfrag->page = pfrag->page; + + return dfrag; +} + +struct mptcp_sendmsg_info { + int mss_now; + int size_goal; + u16 limit; + u16 sent; + unsigned int flags; + bool data_lock_held; +}; + +static int mptcp_check_allowed_size(const struct mptcp_sock *msk, struct sock *ssk, + u64 data_seq, int avail_size) +{ + u64 window_end = mptcp_wnd_end(msk); + u64 mptcp_snd_wnd; + + if (__mptcp_check_fallback(msk)) + return avail_size; + + mptcp_snd_wnd = window_end - data_seq; + avail_size = min_t(unsigned int, mptcp_snd_wnd, avail_size); + + if (unlikely(tcp_sk(ssk)->snd_wnd < mptcp_snd_wnd)) { + tcp_sk(ssk)->snd_wnd = min_t(u64, U32_MAX, mptcp_snd_wnd); + MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_SNDWNDSHARED); + } + + return avail_size; +} + +static bool __mptcp_add_ext(struct sk_buff *skb, gfp_t gfp) +{ + struct skb_ext *mpext = __skb_ext_alloc(gfp); + + if (!mpext) + return false; + __skb_ext_set(skb, SKB_EXT_MPTCP, mpext); + return true; +} + +static struct sk_buff *__mptcp_do_alloc_tx_skb(struct sock *sk, gfp_t gfp) +{ + struct sk_buff *skb; + + skb = alloc_skb_fclone(MAX_TCP_HEADER, gfp); + if (likely(skb)) { + if (likely(__mptcp_add_ext(skb, gfp))) { + skb_reserve(skb, MAX_TCP_HEADER); + skb->ip_summed = CHECKSUM_PARTIAL; + INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); + return skb; + } + __kfree_skb(skb); + } else { + mptcp_enter_memory_pressure(sk); + } + return NULL; +} + +static struct sk_buff *__mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp) +{ + struct sk_buff *skb; + + skb = __mptcp_do_alloc_tx_skb(sk, gfp); + if (!skb) + return NULL; + + if (likely(sk_wmem_schedule(ssk, skb->truesize))) { + tcp_skb_entail(ssk, skb); + return skb; + } + tcp_skb_tsorted_anchor_cleanup(skb); + kfree_skb(skb); + return NULL; +} + +static struct sk_buff *mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, bool data_lock_held) +{ + gfp_t gfp = data_lock_held ? GFP_ATOMIC : sk->sk_allocation; + + return __mptcp_alloc_tx_skb(sk, ssk, gfp); +} + +/* note: this always recompute the csum on the whole skb, even + * if we just appended a single frag. More status info needed + */ +static void mptcp_update_data_checksum(struct sk_buff *skb, int added) +{ + struct mptcp_ext *mpext = mptcp_get_ext(skb); + __wsum csum = ~csum_unfold(mpext->csum); + int offset = skb->len - added; + + mpext->csum = csum_fold(csum_block_add(csum, skb_checksum(skb, offset, added, 0), offset)); +} + +static void mptcp_update_infinite_map(struct mptcp_sock *msk, + struct sock *ssk, + struct mptcp_ext *mpext) +{ + if (!mpext) + return; + + mpext->infinite_map = 1; + mpext->data_len = 0; + + MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX); + mptcp_subflow_ctx(ssk)->send_infinite_map = 0; + pr_fallback(msk); + mptcp_do_fallback(ssk); +} + +static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, + struct mptcp_data_frag *dfrag, + struct mptcp_sendmsg_info *info) +{ + u64 data_seq = dfrag->data_seq + info->sent; + int offset = dfrag->offset + info->sent; + struct mptcp_sock *msk = mptcp_sk(sk); + bool zero_window_probe = false; + struct mptcp_ext *mpext = NULL; + bool can_coalesce = false; + bool reuse_skb = true; + struct sk_buff *skb; + size_t copy; + int i; + pr_debug("msk=%p ssk=%p sending dfrag at seq=%llu len=%u already sent=%u", + msk, ssk, dfrag->data_seq, dfrag->data_len, info->sent); + + if (WARN_ON_ONCE(info->sent > info->limit || + info->limit > dfrag->data_len)) + return 0; + + if (unlikely(!__tcp_can_send(ssk))) + return -EAGAIN; + + /* compute send limit */ + info->mss_now = tcp_send_mss(ssk, &info->size_goal, info->flags); + copy = info->size_goal; + + skb = tcp_write_queue_tail(ssk); + if (skb && copy > skb->len) { /* Limit the write to the size available in the * current skb, if any, so that we create at most a new skb. * Explicitly tells TCP internals to avoid collapsing on later * queue management operation, to avoid breaking the ext <-> * SSN association set here */ - can_collapse = (size_goal - skb->len > 0) && - mptcp_skb_can_collapse_to(msk, skb, mpext); - if (!can_collapse) + mpext = skb_ext_find(skb, SKB_EXT_MPTCP); + if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) { TCP_SKB_CB(skb)->eor = 1; - else - avail_size = size_goal - skb->len; + goto alloc_skb; + } + + i = skb_shinfo(skb)->nr_frags; + can_coalesce = skb_can_coalesce(skb, i, dfrag->page, offset); + if (!can_coalesce && i >= READ_ONCE(sysctl_max_skb_frags)) { + tcp_mark_push(tcp_sk(ssk), skb); + goto alloc_skb; + } + + copy -= skb->len; + } else { +alloc_skb: + skb = mptcp_alloc_tx_skb(sk, ssk, info->data_lock_held); + if (!skb) + return -ENOMEM; + + i = skb_shinfo(skb)->nr_frags; + reuse_skb = false; + mpext = skb_ext_find(skb, SKB_EXT_MPTCP); } - psize = min_t(size_t, pfrag->size - pfrag->offset, avail_size); - /* Copy to page */ - pr_debug("left=%zu", msg_data_left(msg)); - psize = copy_page_from_iter(pfrag->page, pfrag->offset, - min_t(size_t, msg_data_left(msg), psize), - &msg->msg_iter); - pr_debug("left=%zu", msg_data_left(msg)); - if (!psize) - return -EINVAL; + /* Zero window and all data acked? Probe. */ + copy = mptcp_check_allowed_size(msk, ssk, data_seq, copy); + if (copy == 0) { + u64 snd_una = READ_ONCE(msk->snd_una); - /* tell the TCP stack to delay the push so that we can safely - * access the skb after the sendpages call - */ - ret = do_tcp_sendpages(ssk, pfrag->page, pfrag->offset, psize, - msg->msg_flags | MSG_SENDPAGE_NOTLAST); - if (ret <= 0) - return ret; - if (unlikely(ret < psize)) - iov_iter_revert(&msg->msg_iter, psize - ret); + if (snd_una != msk->snd_nxt) { + tcp_remove_empty_skb(ssk); + return 0; + } - /* if the tail skb extension is still the cached one, collapsing - * really happened. Note: we can't check for 'same skb' as the sk_buff - * hdr on tail can be transmitted, freed and re-allocated by the - * do_tcp_sendpages() call - */ - tail = tcp_write_queue_tail(ssk); - if (mpext && tail && mpext == skb_ext_find(tail, SKB_EXT_MPTCP)) { - WARN_ON_ONCE(!can_collapse); - mpext->data_len += ret; - goto out; + zero_window_probe = true; + data_seq = snd_una - 1; + copy = 1; + + /* all mptcp-level data is acked, no skbs should be present into the + * ssk write queue + */ + WARN_ON_ONCE(reuse_skb); } - skb = tcp_write_queue_tail(ssk); - mpext = __skb_ext_set(skb, SKB_EXT_MPTCP, msk->cached_ext); - msk->cached_ext = NULL; + copy = min_t(size_t, copy, info->limit - info->sent); + if (!sk_wmem_schedule(ssk, copy)) { + tcp_remove_empty_skb(ssk); + return -ENOMEM; + } + + if (can_coalesce) { + skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); + } else { + get_page(dfrag->page); + skb_fill_page_desc(skb, i, dfrag->page, offset, copy); + } + + skb->len += copy; + skb->data_len += copy; + skb->truesize += copy; + sk_wmem_queued_add(ssk, copy); + sk_mem_charge(ssk, copy); + WRITE_ONCE(tcp_sk(ssk)->write_seq, tcp_sk(ssk)->write_seq + copy); + TCP_SKB_CB(skb)->end_seq += copy; + tcp_skb_pcount_set(skb, 0); + + /* on skb reuse we just need to update the DSS len */ + if (reuse_skb) { + TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; + mpext->data_len += copy; + WARN_ON_ONCE(zero_window_probe); + goto out; + } memset(mpext, 0, sizeof(*mpext)); - mpext->data_seq = msk->write_seq; + mpext->data_seq = data_seq; mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq; - mpext->data_len = ret; + mpext->data_len = copy; mpext->use_map = 1; mpext->dsn64 = 1; @@ -240,220 +1347,773 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, mpext->data_seq, mpext->subflow_seq, mpext->data_len, mpext->dsn64); + if (zero_window_probe) { + mptcp_subflow_ctx(ssk)->rel_write_seq += copy; + mpext->frozen = 1; + if (READ_ONCE(msk->csum_enabled)) + mptcp_update_data_checksum(skb, copy); + tcp_push_pending_frames(ssk); + return 0; + } out: - pfrag->offset += ret; - msk->write_seq += ret; - mptcp_subflow_ctx(ssk)->rel_write_seq += ret; + if (READ_ONCE(msk->csum_enabled)) + mptcp_update_data_checksum(skb, copy); + if (mptcp_subflow_ctx(ssk)->send_infinite_map) + mptcp_update_infinite_map(msk, ssk, mpext); + trace_mptcp_sendmsg_frag(mpext); + mptcp_subflow_ctx(ssk)->rel_write_seq += copy; + return copy; +} - return ret; +#define MPTCP_SEND_BURST_SIZE ((1 << 16) - \ + sizeof(struct tcphdr) - \ + MAX_TCP_OPTION_SPACE - \ + sizeof(struct ipv6hdr) - \ + sizeof(struct frag_hdr)) + +struct subflow_send_info { + struct sock *ssk; + u64 linger_time; +}; + +void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow) +{ + if (!subflow->stale) + return; + + subflow->stale = 0; + MPTCP_INC_STATS(sock_net(mptcp_subflow_tcp_sock(subflow)), MPTCP_MIB_SUBFLOWRECOVER); } -static void ssk_check_wmem(struct mptcp_sock *msk, struct sock *ssk) +bool mptcp_subflow_active(struct mptcp_subflow_context *subflow) { - struct socket *sock; + if (unlikely(subflow->stale)) { + u32 rcv_tstamp = READ_ONCE(tcp_sk(mptcp_subflow_tcp_sock(subflow))->rcv_tstamp); - if (likely(sk_stream_is_writeable(ssk))) - return; + if (subflow->stale_rcv_tstamp == rcv_tstamp) + return false; + + mptcp_subflow_set_active(subflow); + } + return __mptcp_subflow_active(subflow); +} + +#define SSK_MODE_ACTIVE 0 +#define SSK_MODE_BACKUP 1 +#define SSK_MODE_MAX 2 - sock = READ_ONCE(ssk->sk_socket); +/* implement the mptcp packet scheduler; + * returns the subflow that will transmit the next DSS + * additionally updates the rtx timeout + */ +static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) +{ + struct subflow_send_info send_info[SSK_MODE_MAX]; + struct mptcp_subflow_context *subflow; + struct sock *sk = (struct sock *)msk; + u32 pace, burst, wmem; + int i, nr_active = 0; + struct sock *ssk; + u64 linger_time; + long tout = 0; + + sock_owned_by_me(sk); + + if (__mptcp_check_fallback(msk)) { + if (!msk->first) + return NULL; + return __tcp_can_send(msk->first) && + sk_stream_memory_free(msk->first) ? msk->first : NULL; + } - if (sock) { - clear_bit(MPTCP_SEND_SPACE, &msk->flags); - smp_mb__after_atomic(); - /* set NOSPACE only after clearing SEND_SPACE flag */ - set_bit(SOCK_NOSPACE, &sock->flags); + /* re-use last subflow, if the burst allow that */ + if (msk->last_snd && msk->snd_burst > 0 && + sk_stream_memory_free(msk->last_snd) && + mptcp_subflow_active(mptcp_subflow_ctx(msk->last_snd))) { + mptcp_set_timeout(sk); + return msk->last_snd; } + + /* pick the subflow with the lower wmem/wspace ratio */ + for (i = 0; i < SSK_MODE_MAX; ++i) { + send_info[i].ssk = NULL; + send_info[i].linger_time = -1; + } + + mptcp_for_each_subflow(msk, subflow) { + trace_mptcp_subflow_get_send(subflow); + ssk = mptcp_subflow_tcp_sock(subflow); + if (!mptcp_subflow_active(subflow)) + continue; + + tout = max(tout, mptcp_timeout_from_subflow(subflow)); + nr_active += !subflow->backup; + pace = subflow->avg_pacing_rate; + if (unlikely(!pace)) { + /* init pacing rate from socket */ + subflow->avg_pacing_rate = READ_ONCE(ssk->sk_pacing_rate); + pace = subflow->avg_pacing_rate; + if (!pace) + continue; + } + + linger_time = div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, pace); + if (linger_time < send_info[subflow->backup].linger_time) { + send_info[subflow->backup].ssk = ssk; + send_info[subflow->backup].linger_time = linger_time; + } + } + __mptcp_set_timeout(sk, tout); + + /* pick the best backup if no other subflow is active */ + if (!nr_active) + send_info[SSK_MODE_ACTIVE].ssk = send_info[SSK_MODE_BACKUP].ssk; + + /* According to the blest algorithm, to avoid HoL blocking for the + * faster flow, we need to: + * - estimate the faster flow linger time + * - use the above to estimate the amount of byte transferred + * by the faster flow + * - check that the amount of queued data is greter than the above, + * otherwise do not use the picked, slower, subflow + * We select the subflow with the shorter estimated time to flush + * the queued mem, which basically ensure the above. We just need + * to check that subflow has a non empty cwin. + */ + ssk = send_info[SSK_MODE_ACTIVE].ssk; + if (!ssk || !sk_stream_memory_free(ssk)) + return NULL; + + burst = min_t(int, MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt); + wmem = READ_ONCE(ssk->sk_wmem_queued); + if (!burst) { + msk->last_snd = NULL; + return ssk; + } + + subflow = mptcp_subflow_ctx(ssk); + subflow->avg_pacing_rate = div_u64((u64)subflow->avg_pacing_rate * wmem + + READ_ONCE(ssk->sk_pacing_rate) * burst, + burst + wmem); + msk->last_snd = ssk; + msk->snd_burst = burst; + return ssk; +} + +static void mptcp_push_release(struct sock *ssk, struct mptcp_sendmsg_info *info) +{ + tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, info->size_goal); + release_sock(ssk); +} + +static void mptcp_update_post_push(struct mptcp_sock *msk, + struct mptcp_data_frag *dfrag, + u32 sent) +{ + u64 snd_nxt_new = dfrag->data_seq; + + dfrag->already_sent += sent; + + msk->snd_burst -= sent; + + snd_nxt_new += dfrag->already_sent; + + /* snd_nxt_new can be smaller than snd_nxt in case mptcp + * is recovering after a failover. In that event, this re-sends + * old segments. + * + * Thus compute snd_nxt_new candidate based on + * the dfrag->data_seq that was sent and the data + * that has been handed to the subflow for transmission + * and skip update in case it was old dfrag. + */ + if (likely(after64(snd_nxt_new, msk->snd_nxt))) + msk->snd_nxt = snd_nxt_new; +} + +void mptcp_check_and_set_pending(struct sock *sk) +{ + if (mptcp_send_head(sk)) + mptcp_sk(sk)->push_pending |= BIT(MPTCP_PUSH_PENDING); +} + +void __mptcp_push_pending(struct sock *sk, unsigned int flags) +{ + struct sock *prev_ssk = NULL, *ssk = NULL; + struct mptcp_sock *msk = mptcp_sk(sk); + struct mptcp_sendmsg_info info = { + .flags = flags, + }; + bool do_check_data_fin = false; + struct mptcp_data_frag *dfrag; + int len; + + while ((dfrag = mptcp_send_head(sk))) { + info.sent = dfrag->already_sent; + info.limit = dfrag->data_len; + len = dfrag->data_len - dfrag->already_sent; + while (len > 0) { + int ret = 0; + + prev_ssk = ssk; + ssk = mptcp_subflow_get_send(msk); + + /* First check. If the ssk has changed since + * the last round, release prev_ssk + */ + if (ssk != prev_ssk && prev_ssk) + mptcp_push_release(prev_ssk, &info); + if (!ssk) + goto out; + + /* Need to lock the new subflow only if different + * from the previous one, otherwise we are still + * helding the relevant lock + */ + if (ssk != prev_ssk) + lock_sock(ssk); + + ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); + if (ret <= 0) { + if (ret == -EAGAIN) + continue; + mptcp_push_release(ssk, &info); + goto out; + } + + do_check_data_fin = true; + info.sent += ret; + len -= ret; + + mptcp_update_post_push(msk, dfrag, ret); + } + WRITE_ONCE(msk->first_pending, mptcp_send_next(sk)); + } + + /* at this point we held the socket lock for the last subflow we used */ + if (ssk) + mptcp_push_release(ssk, &info); + +out: + /* ensure the rtx timer is running */ + if (!mptcp_timer_pending(sk)) + mptcp_reset_timer(sk); + if (do_check_data_fin) + __mptcp_check_send_data_fin(sk); +} + +static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + struct mptcp_sendmsg_info info = { + .data_lock_held = true, + }; + struct mptcp_data_frag *dfrag; + struct sock *xmit_ssk; + int len, copied = 0; + bool first = true; + + info.flags = 0; + while ((dfrag = mptcp_send_head(sk))) { + info.sent = dfrag->already_sent; + info.limit = dfrag->data_len; + len = dfrag->data_len - dfrag->already_sent; + while (len > 0) { + int ret = 0; + + /* the caller already invoked the packet scheduler, + * check for a different subflow usage only after + * spooling the first chunk of data + */ + xmit_ssk = first ? ssk : mptcp_subflow_get_send(mptcp_sk(sk)); + if (!xmit_ssk) + goto out; + if (xmit_ssk != ssk) { + mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk), + MPTCP_DELEGATE_SEND); + goto out; + } + + ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); + if (ret <= 0) + goto out; + + info.sent += ret; + copied += ret; + len -= ret; + first = false; + + mptcp_update_post_push(msk, dfrag, ret); + } + WRITE_ONCE(msk->first_pending, mptcp_send_next(sk)); + } + +out: + /* __mptcp_alloc_tx_skb could have released some wmem and we are + * not going to flush it via release_sock() + */ + if (copied) { + tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle, + info.size_goal); + if (!mptcp_timer_pending(sk)) + mptcp_reset_timer(sk); + + if (msk->snd_data_fin_enable && + msk->snd_nxt + 1 == msk->write_seq) + mptcp_schedule_work(sk); + } +} + +static void mptcp_set_nospace(struct sock *sk) +{ + /* enable autotune */ + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + + /* will be cleared on avail space */ + set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags); +} + +static int mptcp_sendmsg_fastopen(struct sock *sk, struct sock *ssk, struct msghdr *msg, + size_t len, int *copied_syn) +{ + unsigned int saved_flags = msg->msg_flags; + struct mptcp_sock *msk = mptcp_sk(sk); + int ret; + + lock_sock(ssk); + msg->msg_flags |= MSG_DONTWAIT; + msk->connect_flags = O_NONBLOCK; + msk->is_sendmsg = 1; + ret = tcp_sendmsg_fastopen(ssk, msg, copied_syn, len, NULL); + msk->is_sendmsg = 0; + msg->msg_flags = saved_flags; + release_sock(ssk); + + /* do the blocking bits of inet_stream_connect outside the ssk socket lock */ + if (ret == -EINPROGRESS && !(msg->msg_flags & MSG_DONTWAIT)) { + ret = __inet_stream_connect(sk->sk_socket, msg->msg_name, + msg->msg_namelen, msg->msg_flags, 1); + + /* Keep the same behaviour of plain TCP: zero the copied bytes in + * case of any error, except timeout or signal + */ + if (ret && ret != -EINPROGRESS && ret != -ERESTARTSYS && ret != -EINTR) + *copied_syn = 0; + } + + return ret; } static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { - int mss_now = 0, size_goal = 0, ret = 0; struct mptcp_sock *msk = mptcp_sk(sk); + struct page_frag *pfrag; struct socket *ssock; size_t copied = 0; - struct sock *ssk; + int ret = 0; long timeo; - if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL)) + /* we don't support FASTOPEN yet */ + if (msg->msg_flags & MSG_FASTOPEN) return -EOPNOTSUPP; + /* silently ignore everything else */ + msg->msg_flags &= MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL; + lock_sock(sk); - ssock = __mptcp_tcp_fallback(msk); - if (unlikely(ssock)) { -fallback: - pr_debug("fallback passthrough"); - ret = sock_sendmsg(ssock, msg); - return ret >= 0 ? ret + copied : (copied ? copied : ret); + + ssock = __mptcp_nmpc_socket(msk); + if (unlikely(ssock && inet_sk(ssock->sk)->defer_connect)) { + int copied_syn = 0; + + ret = mptcp_sendmsg_fastopen(sk, ssock->sk, msg, len, &copied_syn); + copied += copied_syn; + if (ret == -EINPROGRESS && copied_syn > 0) + goto out; + else if (ret) + goto do_error; } timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); - ssk = mptcp_subflow_get(msk); - if (!ssk) { - release_sock(sk); - return -ENOTCONN; + if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) { + ret = sk_stream_wait_connect(sk, &timeo); + if (ret) + goto do_error; } - pr_debug("conn_list->subflow=%p", ssk); + ret = -EPIPE; + if (unlikely(sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))) + goto do_error; + + pfrag = sk_page_frag(sk); - lock_sock(ssk); while (msg_data_left(msg)) { - ret = mptcp_sendmsg_frag(sk, ssk, msg, &timeo, &mss_now, - &size_goal); - if (ret < 0) - break; - if (ret == 0 && unlikely(__mptcp_needs_tcp_fallback(msk))) { - release_sock(ssk); - ssock = __mptcp_tcp_fallback(msk); - goto fallback; + int total_ts, frag_truesize = 0; + struct mptcp_data_frag *dfrag; + bool dfrag_collapsed; + size_t psize, offset; + + /* reuse tail pfrag, if possible, or carve a new one from the + * page allocator + */ + dfrag = mptcp_pending_tail(sk); + dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag); + if (!dfrag_collapsed) { + if (!sk_stream_memory_free(sk)) + goto wait_for_memory; + + if (!mptcp_page_frag_refill(sk, pfrag)) + goto wait_for_memory; + + dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset); + frag_truesize = dfrag->overhead; } - copied += ret; - } + /* we do not bound vs wspace, to allow a single packet. + * memory accounting will prevent execessive memory usage + * anyway + */ + offset = dfrag->offset + dfrag->data_len; + psize = pfrag->size - offset; + psize = min_t(size_t, psize, msg_data_left(msg)); + total_ts = psize + frag_truesize; + + if (!sk_wmem_schedule(sk, total_ts)) + goto wait_for_memory; + + if (copy_page_from_iter(dfrag->page, offset, psize, + &msg->msg_iter) != psize) { + ret = -EFAULT; + goto do_error; + } - if (copied) { - ret = copied; - tcp_push(ssk, msg->msg_flags, mss_now, tcp_sk(ssk)->nonagle, - size_goal); + /* data successfully copied into the write queue */ + sk->sk_forward_alloc -= total_ts; + copied += psize; + dfrag->data_len += psize; + frag_truesize += psize; + pfrag->offset += frag_truesize; + WRITE_ONCE(msk->write_seq, msk->write_seq + psize); + + /* charge data on mptcp pending queue to the msk socket + * Note: we charge such data both to sk and ssk + */ + sk_wmem_queued_add(sk, frag_truesize); + if (!dfrag_collapsed) { + get_page(dfrag->page); + list_add_tail(&dfrag->list, &msk->rtx_queue); + if (!msk->first_pending) + WRITE_ONCE(msk->first_pending, dfrag); + } + pr_debug("msk=%p dfrag at seq=%llu len=%u sent=%u new=%d", msk, + dfrag->data_seq, dfrag->data_len, dfrag->already_sent, + !dfrag_collapsed); + + continue; + +wait_for_memory: + mptcp_set_nospace(sk); + __mptcp_push_pending(sk, msg->msg_flags); + ret = sk_stream_wait_memory(sk, &timeo); + if (ret) + goto do_error; } - ssk_check_wmem(msk, ssk); - release_sock(ssk); + if (copied) + __mptcp_push_pending(sk, msg->msg_flags); + +out: release_sock(sk); - return ret; + return copied; + +do_error: + if (copied) + goto out; + + copied = sk_stream_error(sk, msg->msg_flags, ret); + goto out; } -int mptcp_read_actor(read_descriptor_t *desc, struct sk_buff *skb, - unsigned int offset, size_t len) +static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, + struct msghdr *msg, + size_t len, int flags, + struct scm_timestamping_internal *tss, + int *cmsg_flags) { - struct mptcp_read_arg *arg = desc->arg.data; - size_t copy_len; - - copy_len = min(desc->count, len); + struct sk_buff *skb, *tmp; + int copied = 0; - if (likely(arg->msg)) { + skb_queue_walk_safe(&msk->receive_queue, skb, tmp) { + u32 offset = MPTCP_SKB_CB(skb)->offset; + u32 data_len = skb->len - offset; + u32 count = min_t(size_t, len - copied, data_len); int err; - err = skb_copy_datagram_msg(skb, offset, arg->msg, copy_len); - if (err) { - pr_debug("error path"); - desc->error = err; - return err; + if (!(flags & MSG_TRUNC)) { + err = skb_copy_datagram_msg(skb, offset, msg, count); + if (unlikely(err < 0)) { + if (!copied) + return err; + break; + } + } + + if (MPTCP_SKB_CB(skb)->has_rxtstamp) { + tcp_update_recv_tstamps(skb, tss); + *cmsg_flags |= MPTCP_CMSG_TS; + } + + copied += count; + + if (count < data_len) { + if (!(flags & MSG_PEEK)) { + MPTCP_SKB_CB(skb)->offset += count; + MPTCP_SKB_CB(skb)->map_seq += count; + } + break; + } + + if (!(flags & MSG_PEEK)) { + /* we will bulk release the skb memory later */ + skb->destructor = NULL; + WRITE_ONCE(msk->rmem_released, msk->rmem_released + skb->truesize); + __skb_unlink(skb, &msk->receive_queue); + __kfree_skb(skb); + } + + if (copied >= len) + break; + } + + return copied; +} + +/* receive buffer autotuning. See tcp_rcv_space_adjust for more information. + * + * Only difference: Use highest rtt estimate of the subflows in use. + */ +static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied) +{ + struct mptcp_subflow_context *subflow; + struct sock *sk = (struct sock *)msk; + u32 time, advmss = 1; + u64 rtt_us, mstamp; + + sock_owned_by_me(sk); + + if (copied <= 0) + return; + + msk->rcvq_space.copied += copied; + + mstamp = div_u64(tcp_clock_ns(), NSEC_PER_USEC); + time = tcp_stamp_us_delta(mstamp, msk->rcvq_space.time); + + rtt_us = msk->rcvq_space.rtt_us; + if (rtt_us && time < (rtt_us >> 3)) + return; + + rtt_us = 0; + mptcp_for_each_subflow(msk, subflow) { + const struct tcp_sock *tp; + u64 sf_rtt_us; + u32 sf_advmss; + + tp = tcp_sk(mptcp_subflow_tcp_sock(subflow)); + + sf_rtt_us = READ_ONCE(tp->rcv_rtt_est.rtt_us); + sf_advmss = READ_ONCE(tp->advmss); + + rtt_us = max(sf_rtt_us, rtt_us); + advmss = max(sf_advmss, advmss); + } + + msk->rcvq_space.rtt_us = rtt_us; + if (time < (rtt_us >> 3) || rtt_us == 0) + return; + + if (msk->rcvq_space.copied <= msk->rcvq_space.space) + goto new_measure; + + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf) && + !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) { + int rcvmem, rcvbuf; + u64 rcvwin, grow; + + rcvwin = ((u64)msk->rcvq_space.copied << 1) + 16 * advmss; + + grow = rcvwin * (msk->rcvq_space.copied - msk->rcvq_space.space); + + do_div(grow, msk->rcvq_space.space); + rcvwin += (grow << 1); + + rcvmem = SKB_TRUESIZE(advmss + MAX_TCP_HEADER); + while (tcp_win_from_space(sk, rcvmem) < advmss) + rcvmem += 128; + + do_div(rcvwin, advmss); + rcvbuf = min_t(u64, rcvwin * rcvmem, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2])); + + if (rcvbuf > sk->sk_rcvbuf) { + u32 window_clamp; + + window_clamp = tcp_win_from_space(sk, rcvbuf); + WRITE_ONCE(sk->sk_rcvbuf, rcvbuf); + + /* Make subflows follow along. If we do not do this, we + * get drops at subflow level if skbs can't be moved to + * the mptcp rx queue fast enough (announced rcv_win can + * exceed ssk->sk_rcvbuf). + */ + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk; + bool slow; + + ssk = mptcp_subflow_tcp_sock(subflow); + slow = lock_sock_fast(ssk); + WRITE_ONCE(ssk->sk_rcvbuf, rcvbuf); + tcp_sk(ssk)->window_clamp = window_clamp; + tcp_cleanup_rbuf(ssk, 1); + unlock_sock_fast(ssk, slow); + } } - } else { - pr_debug("Flushing skb payload"); } - desc->count -= copy_len; + msk->rcvq_space.space = msk->rcvq_space.copied; +new_measure: + msk->rcvq_space.copied = 0; + msk->rcvq_space.time = mstamp; +} + +static void __mptcp_update_rmem(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + if (!msk->rmem_released) + return; - pr_debug("consumed %zu bytes, %zu left", copy_len, desc->count); - return copy_len; + atomic_sub(msk->rmem_released, &sk->sk_rmem_alloc); + mptcp_rmem_uncharge(sk, msk->rmem_released); + WRITE_ONCE(msk->rmem_released, 0); } -static void mptcp_wait_data(struct sock *sk, long *timeo) +static void __mptcp_splice_receive_queue(struct sock *sk) { - DEFINE_WAIT_FUNC(wait, woken_wake_function); struct mptcp_sock *msk = mptcp_sk(sk); - add_wait_queue(sk_sleep(sk), &wait); - sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); + skb_queue_splice_tail_init(&sk->sk_receive_queue, &msk->receive_queue); +} + +static bool __mptcp_move_skbs(struct mptcp_sock *msk) +{ + struct sock *sk = (struct sock *)msk; + unsigned int moved = 0; + bool ret, done; + + do { + struct sock *ssk = mptcp_subflow_recv_lookup(msk); + bool slowpath; + + /* we can have data pending in the subflows only if the msk + * receive buffer was full at subflow_data_ready() time, + * that is an unlikely slow path. + */ + if (likely(!ssk)) + break; + + slowpath = lock_sock_fast(ssk); + mptcp_data_lock(sk); + __mptcp_update_rmem(sk); + done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved); + mptcp_data_unlock(sk); + + if (unlikely(ssk->sk_err)) + __mptcp_error_report(sk); + unlock_sock_fast(ssk, slowpath); + } while (!done); + + /* acquire the data lock only if some input data is pending */ + ret = moved > 0; + if (!RB_EMPTY_ROOT(&msk->out_of_order_queue) || + !skb_queue_empty_lockless(&sk->sk_receive_queue)) { + mptcp_data_lock(sk); + __mptcp_update_rmem(sk); + ret |= __mptcp_ofo_queue(msk); + __mptcp_splice_receive_queue(sk); + mptcp_data_unlock(sk); + } + if (ret) + mptcp_check_data_fin((struct sock *)msk); + return !skb_queue_empty(&msk->receive_queue); +} + +static unsigned int mptcp_inq_hint(const struct sock *sk) +{ + const struct mptcp_sock *msk = mptcp_sk(sk); + const struct sk_buff *skb; + + skb = skb_peek(&msk->receive_queue); + if (skb) { + u64 hint_val = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq; + + if (hint_val >= INT_MAX) + return INT_MAX; + + return (unsigned int)hint_val; + } - sk_wait_event(sk, timeo, - test_and_clear_bit(MPTCP_DATA_READY, &msk->flags), &wait); + if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) + return 1; - sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); - remove_wait_queue(sk_sleep(sk), &wait); + return 0; } static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, - int nonblock, int flags, int *addr_len) + int flags, int *addr_len) { struct mptcp_sock *msk = mptcp_sk(sk); - struct mptcp_subflow_context *subflow; - bool more_data_avail = false; - struct mptcp_read_arg arg; - read_descriptor_t desc; - bool wait_data = false; - struct socket *ssock; - struct tcp_sock *tp; - bool done = false; - struct sock *ssk; - int copied = 0; + struct scm_timestamping_internal tss; + int copied = 0, cmsg_flags = 0; int target; long timeo; - if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT)) - return -EOPNOTSUPP; + /* MSG_ERRQUEUE is really a no-op till we support IP_RECVERR */ + if (unlikely(flags & MSG_ERRQUEUE)) + return inet_recv_error(sk, msg, len, addr_len); lock_sock(sk); - ssock = __mptcp_tcp_fallback(msk); - if (unlikely(ssock)) { -fallback: - pr_debug("fallback-read subflow=%p", - mptcp_subflow_ctx(ssock->sk)); - copied = sock_recvmsg(ssock, msg, flags); - return copied; + if (unlikely(sk->sk_state == TCP_LISTEN)) { + copied = -ENOTCONN; + goto out_err; } - arg.msg = msg; - desc.arg.data = &arg; - desc.error = 0; - - timeo = sock_rcvtimeo(sk, nonblock); + timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); len = min_t(size_t, len, INT_MAX); target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); - while (!done) { - u32 map_remaining; + if (unlikely(msk->recvmsg_inq)) + cmsg_flags = MPTCP_CMSG_INQ; + + while (copied < len) { int bytes_read; - ssk = mptcp_subflow_recv_lookup(msk); - pr_debug("msk=%p ssk=%p", msk, ssk); - if (!ssk) - goto wait_for_data; - - subflow = mptcp_subflow_ctx(ssk); - tp = tcp_sk(ssk); - - lock_sock(ssk); - do { - /* try to read as much data as available */ - map_remaining = subflow->map_data_len - - mptcp_subflow_get_map_offset(subflow); - desc.count = min_t(size_t, len - copied, map_remaining); - pr_debug("reading %zu bytes, copied %d", desc.count, - copied); - bytes_read = tcp_read_sock(ssk, &desc, - mptcp_read_actor); - if (bytes_read < 0) { - if (!copied) - copied = bytes_read; - done = true; - goto next; - } + bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags, &tss, &cmsg_flags); + if (unlikely(bytes_read < 0)) { + if (!copied) + copied = bytes_read; + goto out_err; + } - pr_debug("msk ack_seq=%llx -> %llx", msk->ack_seq, - msk->ack_seq + bytes_read); - msk->ack_seq += bytes_read; - copied += bytes_read; - if (copied >= len) { - done = true; - goto next; - } - if (tp->urg_data && tp->urg_seq == tp->copied_seq) { - pr_err("Urgent data present, cannot proceed"); - done = true; - goto next; - } -next: - more_data_avail = mptcp_subflow_data_available(ssk); - } while (more_data_avail && !done); - release_sock(ssk); - continue; + copied += bytes_read; + + /* be sure to advertise window change */ + mptcp_cleanup_rbuf(msk); -wait_for_data: - more_data_avail = false; + if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk)) + continue; /* only the master socket status is relevant here. The exit * conditions mirror closely tcp_recvmsg() @@ -474,8 +2134,17 @@ wait_for_data: break; } - if (sk->sk_shutdown & RCV_SHUTDOWN) + if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags)) + mptcp_check_for_eof(msk); + + if (sk->sk_shutdown & RCV_SHUTDOWN) { + /* race breaker: the shutdown could be after the + * previous receive queue check + */ + if (__mptcp_move_skbs(msk)) + continue; break; + } if (sk->sk_state == TCP_CLOSE) { copied = -ENOTCONN; @@ -494,30 +2163,157 @@ wait_for_data: } pr_debug("block timeout %ld", timeo); - wait_data = true; - mptcp_wait_data(sk, &timeo); - if (unlikely(__mptcp_tcp_fallback(msk))) - goto fallback; + sk_wait_data(sk, &timeo, NULL); } - if (more_data_avail) { - if (!test_bit(MPTCP_DATA_READY, &msk->flags)) - set_bit(MPTCP_DATA_READY, &msk->flags); - } else if (!wait_data) { - clear_bit(MPTCP_DATA_READY, &msk->flags); +out_err: + if (cmsg_flags && copied >= 0) { + if (cmsg_flags & MPTCP_CMSG_TS) + tcp_recv_timestamp(msg, sk, &tss); - /* .. race-breaker: ssk might get new data after last - * data_available() returns false. - */ - ssk = mptcp_subflow_recv_lookup(msk); - if (unlikely(ssk)) - set_bit(MPTCP_DATA_READY, &msk->flags); + if (cmsg_flags & MPTCP_CMSG_INQ) { + unsigned int inq = mptcp_inq_hint(sk); + + put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq); + } } + pr_debug("msk=%p rx queue empty=%d:%d copied=%d", + msk, skb_queue_empty_lockless(&sk->sk_receive_queue), + skb_queue_empty(&msk->receive_queue), copied); + if (!(flags & MSG_PEEK)) + mptcp_rcv_space_adjust(msk, copied); + release_sock(sk); return copied; } +static void mptcp_retransmit_timer(struct timer_list *t) +{ + struct inet_connection_sock *icsk = from_timer(icsk, t, + icsk_retransmit_timer); + struct sock *sk = &icsk->icsk_inet.sk; + struct mptcp_sock *msk = mptcp_sk(sk); + + bh_lock_sock(sk); + if (!sock_owned_by_user(sk)) { + /* we need a process context to retransmit */ + if (!test_and_set_bit(MPTCP_WORK_RTX, &msk->flags)) + mptcp_schedule_work(sk); + } else { + /* delegate our work to tcp_release_cb() */ + __set_bit(MPTCP_RETRANSMIT, &msk->cb_flags); + } + bh_unlock_sock(sk); + sock_put(sk); +} + +static void mptcp_timeout_timer(struct timer_list *t) +{ + struct sock *sk = from_timer(sk, t, sk_timer); + + mptcp_schedule_work(sk); + sock_put(sk); +} + +/* Find an idle subflow. Return NULL if there is unacked data at tcp + * level. + * + * A backup subflow is returned only if that is the only kind available. + */ +static struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk) +{ + struct sock *backup = NULL, *pick = NULL; + struct mptcp_subflow_context *subflow; + int min_stale_count = INT_MAX; + + sock_owned_by_me((const struct sock *)msk); + + if (__mptcp_check_fallback(msk)) + return NULL; + + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + if (!__mptcp_subflow_active(subflow)) + continue; + + /* still data outstanding at TCP level? skip this */ + if (!tcp_rtx_and_write_queues_empty(ssk)) { + mptcp_pm_subflow_chk_stale(msk, ssk); + min_stale_count = min_t(int, min_stale_count, subflow->stale_count); + continue; + } + + if (subflow->backup) { + if (!backup) + backup = ssk; + continue; + } + + if (!pick) + pick = ssk; + } + + if (pick) + return pick; + + /* use backup only if there are no progresses anywhere */ + return min_stale_count > 1 ? backup : NULL; +} + +static void mptcp_dispose_initial_subflow(struct mptcp_sock *msk) +{ + if (msk->subflow) { + iput(SOCK_INODE(msk->subflow)); + msk->subflow = NULL; + } +} + +bool __mptcp_retransmit_pending_data(struct sock *sk) +{ + struct mptcp_data_frag *cur, *rtx_head; + struct mptcp_sock *msk = mptcp_sk(sk); + + if (__mptcp_check_fallback(mptcp_sk(sk))) + return false; + + if (tcp_rtx_and_write_queues_empty(sk)) + return false; + + /* the closing socket has some data untransmitted and/or unacked: + * some data in the mptcp rtx queue has not really xmitted yet. + * keep it simple and re-inject the whole mptcp level rtx queue + */ + mptcp_data_lock(sk); + __mptcp_clean_una_wakeup(sk); + rtx_head = mptcp_rtx_head(sk); + if (!rtx_head) { + mptcp_data_unlock(sk); + return false; + } + + msk->recovery_snd_nxt = msk->snd_nxt; + msk->recovery = true; + mptcp_data_unlock(sk); + + msk->first_pending = rtx_head; + msk->snd_burst = 0; + + /* be sure to clear the "sent status" on all re-injected fragments */ + list_for_each_entry(cur, &msk->rtx_queue, list) { + if (!cur->already_sent) + break; + cur->already_sent = 0; + } + + return true; +} + +/* flags for __mptcp_close_ssk() */ +#define MPTCP_CF_PUSH BIT(1) +#define MPTCP_CF_FASTCLOSE BIT(2) + /* subflow sockets can be either outgoing (connect) or incoming * (accept). * @@ -528,19 +2324,89 @@ wait_for_data: */ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, struct mptcp_subflow_context *subflow, - long timeout) + unsigned int flags) { - struct socket *sock = READ_ONCE(ssk->sk_socket); + struct mptcp_sock *msk = mptcp_sk(sk); + bool need_push, dispose_it; - list_del(&subflow->node); + dispose_it = !msk->subflow || ssk != msk->subflow->sk; + if (dispose_it) + list_del(&subflow->node); - if (sock && sock != sk->sk_socket) { - /* outgoing subflow */ - sock_release(sock); + lock_sock_nested(ssk, SINGLE_DEPTH_NESTING); + + if (flags & MPTCP_CF_FASTCLOSE) { + /* be sure to force the tcp_disconnect() path, + * to generate the egress reset + */ + ssk->sk_lingertime = 0; + sock_set_flag(ssk, SOCK_LINGER); + subflow->send_fastclose = 1; + } + + need_push = (flags & MPTCP_CF_PUSH) && __mptcp_retransmit_pending_data(sk); + if (!dispose_it) { + tcp_disconnect(ssk, 0); + msk->subflow->state = SS_UNCONNECTED; + mptcp_subflow_ctx_reset(subflow); + release_sock(ssk); + + goto out; + } + + /* if we are invoked by the msk cleanup code, the subflow is + * already orphaned + */ + if (ssk->sk_socket) + sock_orphan(ssk); + + subflow->disposable = 1; + + /* if ssk hit tcp_done(), tcp_cleanup_ulp() cleared the related ops + * the ssk has been already destroyed, we just need to release the + * reference owned by msk; + */ + if (!inet_csk(ssk)->icsk_ulp_ops) { + kfree_rcu(subflow, rcu); } else { - /* incoming subflow */ - tcp_close(ssk, timeout); + /* otherwise tcp will dispose of the ssk and subflow ctx */ + if (ssk->sk_state == TCP_LISTEN) { + tcp_set_state(ssk, TCP_CLOSE); + mptcp_subflow_queue_clean(ssk); + inet_csk_listen_stop(ssk); + } + __tcp_close(ssk, 0); + + /* close acquired an extra ref */ + __sock_put(ssk); } + release_sock(ssk); + + sock_put(ssk); + + if (ssk == msk->first) + msk->first = NULL; + +out: + if (ssk == msk->last_snd) + msk->last_snd = NULL; + + if (need_push) + __mptcp_push_pending(sk, 0); +} + +void mptcp_close_ssk(struct sock *sk, struct sock *ssk, + struct mptcp_subflow_context *subflow) +{ + if (sk->sk_state == TCP_ESTABLISHED) + mptcp_event(MPTCP_EVENT_SUB_CLOSED, mptcp_sk(sk), ssk, GFP_KERNEL); + + /* subflow aborted before reaching the fully_established status + * attempt the creation of the next subflow + */ + mptcp_pm_subflow_check_next(mptcp_sk(sk), ssk, subflow); + + __mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_PUSH); } static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) @@ -548,28 +2414,353 @@ static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) return 0; } +static void __mptcp_close_subflow(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow, *tmp; + + might_sleep(); + + mptcp_for_each_subflow_safe(msk, subflow, tmp) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + if (inet_sk_state_load(ssk) != TCP_CLOSE) + continue; + + /* 'subflow_data_ready' will re-sched once rx queue is empty */ + if (!skb_queue_empty_lockless(&ssk->sk_receive_queue)) + continue; + + mptcp_close_ssk((struct sock *)msk, ssk, subflow); + } +} + +static bool mptcp_check_close_timeout(const struct sock *sk) +{ + s32 delta = tcp_jiffies32 - inet_csk(sk)->icsk_mtup.probe_timestamp; + struct mptcp_subflow_context *subflow; + + if (delta >= TCP_TIMEWAIT_LEN) + return true; + + /* if all subflows are in closed status don't bother with additional + * timeout + */ + mptcp_for_each_subflow(mptcp_sk(sk), subflow) { + if (inet_sk_state_load(mptcp_subflow_tcp_sock(subflow)) != + TCP_CLOSE) + return false; + } + return true; +} + +static void mptcp_check_fastclose(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow, *tmp; + struct sock *sk = &msk->sk.icsk_inet.sk; + + if (likely(!READ_ONCE(msk->rcv_fastclose))) + return; + + mptcp_token_destroy(msk); + + mptcp_for_each_subflow_safe(msk, subflow, tmp) { + struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); + bool slow; + + slow = lock_sock_fast(tcp_sk); + if (tcp_sk->sk_state != TCP_CLOSE) { + tcp_send_active_reset(tcp_sk, GFP_ATOMIC); + tcp_set_state(tcp_sk, TCP_CLOSE); + } + unlock_sock_fast(tcp_sk, slow); + } + + /* Mirror the tcp_reset() error propagation */ + switch (sk->sk_state) { + case TCP_SYN_SENT: + sk->sk_err = ECONNREFUSED; + break; + case TCP_CLOSE_WAIT: + sk->sk_err = EPIPE; + break; + case TCP_CLOSE: + return; + default: + sk->sk_err = ECONNRESET; + } + + inet_sk_state_store(sk, TCP_CLOSE); + sk->sk_shutdown = SHUTDOWN_MASK; + smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ + set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags); + + /* the calling mptcp_worker will properly destroy the socket */ + if (sock_flag(sk, SOCK_DEAD)) + return; + + sk->sk_state_change(sk); + sk_error_report(sk); +} + +static void __mptcp_retrans(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + struct mptcp_sendmsg_info info = {}; + struct mptcp_data_frag *dfrag; + size_t copied = 0; + struct sock *ssk; + int ret; + + mptcp_clean_una_wakeup(sk); + + /* first check ssk: need to kick "stale" logic */ + ssk = mptcp_subflow_get_retrans(msk); + dfrag = mptcp_rtx_head(sk); + if (!dfrag) { + if (mptcp_data_fin_enabled(msk)) { + struct inet_connection_sock *icsk = inet_csk(sk); + + icsk->icsk_retransmits++; + mptcp_set_datafin_timeout(sk); + mptcp_send_ack(msk); + + goto reset_timer; + } + + if (!mptcp_send_head(sk)) + return; + + goto reset_timer; + } + + if (!ssk) + goto reset_timer; + + lock_sock(ssk); + + /* limit retransmission to the bytes already sent on some subflows */ + info.sent = 0; + info.limit = READ_ONCE(msk->csum_enabled) ? dfrag->data_len : dfrag->already_sent; + while (info.sent < info.limit) { + ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); + if (ret <= 0) + break; + + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RETRANSSEGS); + copied += ret; + info.sent += ret; + } + if (copied) { + dfrag->already_sent = max(dfrag->already_sent, info.sent); + tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle, + info.size_goal); + WRITE_ONCE(msk->allow_infinite_fallback, false); + } + + release_sock(ssk); + +reset_timer: + mptcp_check_and_set_pending(sk); + + if (!mptcp_timer_pending(sk)) + mptcp_reset_timer(sk); +} + +/* schedule the timeout timer for the relevant event: either close timeout + * or mp_fail timeout. The close timeout takes precedence on the mp_fail one + */ +void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout) +{ + struct sock *sk = (struct sock *)msk; + unsigned long timeout, close_timeout; + + if (!fail_tout && !sock_flag(sk, SOCK_DEAD)) + return; + + close_timeout = inet_csk(sk)->icsk_mtup.probe_timestamp - tcp_jiffies32 + jiffies + TCP_TIMEWAIT_LEN; + + /* the close timeout takes precedence on the fail one, and here at least one of + * them is active + */ + timeout = sock_flag(sk, SOCK_DEAD) ? close_timeout : fail_tout; + + sk_reset_timer(sk, &sk->sk_timer, timeout); +} + +static void mptcp_mp_fail_no_response(struct mptcp_sock *msk) +{ + struct sock *ssk = msk->first; + bool slow; + + if (!ssk) + return; + + pr_debug("MP_FAIL doesn't respond, reset the subflow"); + + slow = lock_sock_fast(ssk); + mptcp_subflow_reset(ssk); + WRITE_ONCE(mptcp_subflow_ctx(ssk)->fail_tout, 0); + unlock_sock_fast(ssk, slow); + + mptcp_reset_timeout(msk, 0); +} + +static void mptcp_do_fastclose(struct sock *sk) +{ + struct mptcp_subflow_context *subflow, *tmp; + struct mptcp_sock *msk = mptcp_sk(sk); + + mptcp_for_each_subflow_safe(msk, subflow, tmp) + __mptcp_close_ssk(sk, mptcp_subflow_tcp_sock(subflow), + subflow, MPTCP_CF_FASTCLOSE); +} + +static void mptcp_worker(struct work_struct *work) +{ + struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); + struct sock *sk = &msk->sk.icsk_inet.sk; + unsigned long fail_tout; + int state; + + lock_sock(sk); + state = sk->sk_state; + if (unlikely(state == TCP_CLOSE)) + goto unlock; + + mptcp_check_data_fin_ack(sk); + + mptcp_check_fastclose(msk); + + mptcp_pm_nl_work(msk); + + if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags)) + mptcp_check_for_eof(msk); + + __mptcp_check_send_data_fin(sk); + mptcp_check_data_fin(sk); + + /* There is no point in keeping around an orphaned sk timedout or + * closed, but we need the msk around to reply to incoming DATA_FIN, + * even if it is orphaned and in FIN_WAIT2 state + */ + if (sock_flag(sk, SOCK_DEAD)) { + if (mptcp_check_close_timeout(sk)) { + inet_sk_state_store(sk, TCP_CLOSE); + mptcp_do_fastclose(sk); + } + if (sk->sk_state == TCP_CLOSE) { + __mptcp_destroy_sock(sk); + goto unlock; + } + } + + if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) + __mptcp_close_subflow(msk); + + if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags)) + __mptcp_retrans(sk); + + fail_tout = msk->first ? READ_ONCE(mptcp_subflow_ctx(msk->first)->fail_tout) : 0; + if (fail_tout && time_after(jiffies, fail_tout)) + mptcp_mp_fail_no_response(msk); + +unlock: + release_sock(sk); + sock_put(sk); +} + static int __mptcp_init_sock(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); INIT_LIST_HEAD(&msk->conn_list); - __set_bit(MPTCP_SEND_SPACE, &msk->flags); + INIT_LIST_HEAD(&msk->join_list); + INIT_LIST_HEAD(&msk->rtx_queue); + INIT_WORK(&msk->work, mptcp_worker); + __skb_queue_head_init(&msk->receive_queue); + msk->out_of_order_queue = RB_ROOT; + msk->first_pending = NULL; + msk->rmem_fwd_alloc = 0; + WRITE_ONCE(msk->rmem_released, 0); + msk->timer_ival = TCP_RTO_MIN; msk->first = NULL; inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss; + WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk))); + WRITE_ONCE(msk->allow_infinite_fallback, true); + msk->recovery = false; + + mptcp_pm_data_init(msk); + + /* re-use the csk retrans timer for MPTCP-level retrans */ + timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0); + timer_setup(&sk->sk_timer, mptcp_timeout_timer, 0); return 0; } +static void mptcp_ca_reset(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + tcp_assign_congestion_control(sk); + strcpy(mptcp_sk(sk)->ca_name, icsk->icsk_ca_ops->name); + + /* no need to keep a reference to the ops, the name will suffice */ + tcp_cleanup_congestion_control(sk); + icsk->icsk_ca_ops = NULL; +} + static int mptcp_init_sock(struct sock *sk) { - if (!mptcp_is_enabled(sock_net(sk))) + struct net *net = sock_net(sk); + int ret; + + ret = __mptcp_init_sock(sk); + if (ret) + return ret; + + if (!mptcp_is_enabled(net)) return -ENOPROTOOPT; - return __mptcp_init_sock(sk); + if (unlikely(!net->mib.mptcp_statistics) && !mptcp_mib_alloc(net)) + return -ENOMEM; + + ret = __mptcp_socket_create(mptcp_sk(sk)); + if (ret) + return ret; + + /* fetch the ca name; do it outside __mptcp_init_sock(), so that clone will + * propagate the correct value + */ + mptcp_ca_reset(sk); + + sk_sockets_allocated_inc(sk); + sk->sk_rcvbuf = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[1]); + sk->sk_sndbuf = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[1]); + + return 0; +} + +static void __mptcp_clear_xmit(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + struct mptcp_data_frag *dtmp, *dfrag; + + WRITE_ONCE(msk->first_pending, NULL); + list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) + dfrag_clear(sk, dfrag); +} + +void mptcp_cancel_work(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + if (cancel_work_sync(&msk->work)) + __sock_put(sk); } -static void mptcp_subflow_shutdown(struct sock *ssk, int how) +void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how) { lock_sock(ssk); @@ -577,47 +2768,213 @@ static void mptcp_subflow_shutdown(struct sock *ssk, int how) case TCP_LISTEN: if (!(how & RCV_SHUTDOWN)) break; - /* fall through */ + fallthrough; case TCP_SYN_SENT: tcp_disconnect(ssk, O_NONBLOCK); break; default: - ssk->sk_shutdown |= how; - tcp_shutdown(ssk, how); + if (__mptcp_check_fallback(mptcp_sk(sk))) { + pr_debug("Fallback"); + ssk->sk_shutdown |= how; + tcp_shutdown(ssk, how); + } else { + pr_debug("Sending DATA_FIN on subflow %p", ssk); + tcp_send_ack(ssk); + if (!mptcp_timer_pending(sk)) + mptcp_reset_timer(sk); + } break; } - /* Wake up anyone sleeping in poll. */ - ssk->sk_state_change(ssk); release_sock(ssk); } -/* Called with msk lock held, releases such lock before returning */ -static void mptcp_close(struct sock *sk, long timeout) +static const unsigned char new_state[16] = { + /* current state: new state: action: */ + [0 /* (Invalid) */] = TCP_CLOSE, + [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, + [TCP_SYN_SENT] = TCP_CLOSE, + [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, + [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, + [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, + [TCP_TIME_WAIT] = TCP_CLOSE, /* should not happen ! */ + [TCP_CLOSE] = TCP_CLOSE, + [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, + [TCP_LAST_ACK] = TCP_LAST_ACK, + [TCP_LISTEN] = TCP_CLOSE, + [TCP_CLOSING] = TCP_CLOSING, + [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ +}; + +static int mptcp_close_state(struct sock *sk) { - struct mptcp_subflow_context *subflow, *tmp; + int next = (int)new_state[sk->sk_state]; + int ns = next & TCP_STATE_MASK; + + inet_sk_state_store(sk, ns); + + return next & TCP_ACTION_FIN; +} + +static void __mptcp_check_send_data_fin(struct sock *sk) +{ + struct mptcp_subflow_context *subflow; struct mptcp_sock *msk = mptcp_sk(sk); - LIST_HEAD(conn_list); - lock_sock(sk); + pr_debug("msk=%p snd_data_fin_enable=%d pending=%d snd_nxt=%llu write_seq=%llu", + msk, msk->snd_data_fin_enable, !!mptcp_send_head(sk), + msk->snd_nxt, msk->write_seq); - mptcp_token_destroy(msk->token); - inet_sk_state_store(sk, TCP_CLOSE); + /* we still need to enqueue subflows or not really shutting down, + * skip this + */ + if (!msk->snd_data_fin_enable || msk->snd_nxt + 1 != msk->write_seq || + mptcp_send_head(sk)) + return; - list_splice_init(&msk->conn_list, &conn_list); + WRITE_ONCE(msk->snd_nxt, msk->write_seq); - release_sock(sk); + /* fallback socket will not get data_fin/ack, can move to the next + * state now + */ + if (__mptcp_check_fallback(msk)) { + WRITE_ONCE(msk->snd_una, msk->write_seq); + if ((1 << sk->sk_state) & (TCPF_CLOSING | TCPF_LAST_ACK)) { + inet_sk_state_store(sk, TCP_CLOSE); + mptcp_close_wake_up(sk); + } else if (sk->sk_state == TCP_FIN_WAIT1) { + inet_sk_state_store(sk, TCP_FIN_WAIT2); + } + } + + mptcp_for_each_subflow(msk, subflow) { + struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); + + mptcp_subflow_shutdown(sk, tcp_sk, SEND_SHUTDOWN); + } +} + +static void __mptcp_wr_shutdown(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + pr_debug("msk=%p snd_data_fin_enable=%d shutdown=%x state=%d pending=%d", + msk, msk->snd_data_fin_enable, sk->sk_shutdown, sk->sk_state, + !!mptcp_send_head(sk)); + + /* will be ignored by fallback sockets */ + WRITE_ONCE(msk->write_seq, msk->write_seq + 1); + WRITE_ONCE(msk->snd_data_fin_enable, 1); + + __mptcp_check_send_data_fin(sk); +} + +static void __mptcp_destroy_sock(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + pr_debug("msk=%p", msk); + + might_sleep(); + + mptcp_stop_timer(sk); + sk_stop_timer(sk, &sk->sk_timer); + msk->pm.status = 0; + + sk->sk_prot->destroy(sk); + + WARN_ON_ONCE(msk->rmem_fwd_alloc); + WARN_ON_ONCE(msk->rmem_released); + sk_stream_kill_queues(sk); + xfrm_sk_free_policy(sk); + + sk_refcnt_debug_release(sk); + sock_put(sk); +} + +static __poll_t mptcp_check_readable(struct mptcp_sock *msk) +{ + /* Concurrent splices from sk_receive_queue into receive_queue will + * always show at least one non-empty queue when checked in this order. + */ + if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue) && + skb_queue_empty_lockless(&msk->receive_queue)) + return 0; + + return EPOLLIN | EPOLLRDNORM; +} - list_for_each_entry_safe(subflow, tmp, &conn_list, node) { +bool __mptcp_close(struct sock *sk, long timeout) +{ + struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk = mptcp_sk(sk); + bool do_cancel_work = false; + + sk->sk_shutdown = SHUTDOWN_MASK; + + if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) { + inet_sk_state_store(sk, TCP_CLOSE); + goto cleanup; + } + + if (mptcp_check_readable(msk)) { + /* the msk has read data, do the MPTCP equivalent of TCP reset */ + inet_sk_state_store(sk, TCP_CLOSE); + mptcp_do_fastclose(sk); + } else if (mptcp_close_state(sk)) { + __mptcp_wr_shutdown(sk); + } + + sk_stream_wait_close(sk, timeout); + +cleanup: + /* orphan all the subflows */ + inet_csk(sk)->icsk_mtup.probe_timestamp = tcp_jiffies32; + mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + bool slow = lock_sock_fast_nested(ssk); - __mptcp_close_ssk(sk, ssk, subflow, timeout); + /* since the close timeout takes precedence on the fail one, + * cancel the latter + */ + if (ssk == msk->first) + subflow->fail_tout = 0; + + sock_orphan(ssk); + unlock_sock_fast(ssk, slow); + } + sock_orphan(sk); + + sock_hold(sk); + pr_debug("msk=%p state=%d", sk, sk->sk_state); + if (mptcp_sk(sk)->token) + mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL); + + if (sk->sk_state == TCP_CLOSE) { + __mptcp_destroy_sock(sk); + do_cancel_work = true; + } else { + mptcp_reset_timeout(msk, 0); } - sk_common_release(sk); + return do_cancel_work; +} + +static void mptcp_close(struct sock *sk, long timeout) +{ + bool do_cancel_work; + + lock_sock(sk); + + do_cancel_work = __mptcp_close(sk, timeout); + release_sock(sk); + if (do_cancel_work) + mptcp_cancel_work(sk); + + sock_put(sk); } -static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk) +void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk) { #if IS_ENABLED(CONFIG_MPTCP_IPV6) const struct ipv6_pinfo *ssk6 = inet6_sk(ssk); @@ -640,6 +2997,42 @@ static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk) inet_sk(msk)->inet_rcv_saddr = inet_sk(ssk)->inet_rcv_saddr; } +static int mptcp_disconnect(struct sock *sk, int flags) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + inet_sk_state_store(sk, TCP_CLOSE); + + mptcp_stop_timer(sk); + sk_stop_timer(sk, &sk->sk_timer); + + if (mptcp_sk(sk)->token) + mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL); + + /* msk->subflow is still intact, the following will not free the first + * subflow + */ + mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE); + msk->last_snd = NULL; + WRITE_ONCE(msk->flags, 0); + msk->cb_flags = 0; + msk->push_pending = 0; + msk->recovery = false; + msk->can_ack = false; + msk->fully_established = false; + msk->rcv_data_fin = false; + msk->snd_data_fin_enable = false; + msk->rcv_fastclose = false; + msk->use_64bit_ack = false; + WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk))); + mptcp_pm_data_reset(msk); + mptcp_ca_reset(sk); + + sk->sk_shutdown = 0; + sk_error_report(sk); + return 0; +} + #if IS_ENABLED(CONFIG_MPTCP_IPV6) static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk) { @@ -649,9 +3042,14 @@ static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk) } #endif -static struct sock *mptcp_sk_clone_lock(const struct sock *sk) +struct sock *mptcp_sk_clone(const struct sock *sk, + const struct mptcp_options_received *mp_opt, + struct request_sock *req) { + struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC); + struct mptcp_sock *msk; + u64 ack_seq; if (!nsk) return NULL; @@ -661,9 +3059,61 @@ static struct sock *mptcp_sk_clone_lock(const struct sock *sk) inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk); #endif + __mptcp_init_sock(nsk); + + msk = mptcp_sk(nsk); + msk->local_key = subflow_req->local_key; + msk->token = subflow_req->token; + msk->subflow = NULL; + WRITE_ONCE(msk->fully_established, false); + if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD) + WRITE_ONCE(msk->csum_enabled, true); + + msk->write_seq = subflow_req->idsn + 1; + msk->snd_nxt = msk->write_seq; + msk->snd_una = msk->write_seq; + msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd; + msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq; + + if (mp_opt->suboptions & OPTIONS_MPTCP_MPC) { + msk->can_ack = true; + msk->remote_key = mp_opt->sndr_key; + mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); + ack_seq++; + WRITE_ONCE(msk->ack_seq, ack_seq); + atomic64_set(&msk->rcv_wnd_sent, ack_seq); + } + + sock_reset_flag(nsk, SOCK_RCU_FREE); + /* will be fully established after successful MPC subflow creation */ + inet_sk_state_store(nsk, TCP_SYN_RECV); + + security_inet_csk_clone(nsk, req); + bh_unlock_sock(nsk); + + /* keep a single reference */ + __sock_put(nsk); return nsk; } +void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk) +{ + const struct tcp_sock *tp = tcp_sk(ssk); + + msk->rcvq_space.copied = 0; + msk->rcvq_space.rtt_us = 0; + + msk->rcvq_space.time = tp->tcp_mstamp; + + /* initial rcv_space offering made to peer */ + msk->rcvq_space.space = min_t(u32, tp->rcv_wnd, + TCP_INIT_CWND * tp->advmss); + if (msk->rcvq_space.space == 0) + msk->rcvq_space.space = TCP_INIT_CWND * TCP_MSS_DEFAULT; + + WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd); +} + static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, bool kern) { @@ -683,128 +3133,215 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, return NULL; pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk)); - if (sk_is_mptcp(newsk)) { struct mptcp_subflow_context *subflow; struct sock *new_mptcp_sock; - struct sock *ssk = newsk; - u64 ack_seq; subflow = mptcp_subflow_ctx(newsk); - lock_sock(sk); + new_mptcp_sock = subflow->conn; - local_bh_disable(); - new_mptcp_sock = mptcp_sk_clone_lock(sk); - if (!new_mptcp_sock) { - *err = -ENOBUFS; - local_bh_enable(); - release_sock(sk); - mptcp_subflow_shutdown(newsk, SHUT_RDWR + 1); - tcp_close(newsk, 0); - return NULL; + /* is_mptcp should be false if subflow->conn is missing, see + * subflow_syn_recv_sock() + */ + if (WARN_ON_ONCE(!new_mptcp_sock)) { + tcp_sk(newsk)->is_mptcp = 0; + goto out; } - __mptcp_init_sock(new_mptcp_sock); + /* acquire the 2nd reference for the owning socket */ + sock_hold(new_mptcp_sock); + newsk = new_mptcp_sock; + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK); + } else { + MPTCP_INC_STATS(sock_net(sk), + MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK); + } - msk = mptcp_sk(new_mptcp_sock); - msk->local_key = subflow->local_key; - msk->token = subflow->token; - msk->subflow = NULL; - msk->first = newsk; +out: + newsk->sk_kern_sock = kern; + return newsk; +} - mptcp_token_update_accept(newsk, new_mptcp_sock); +void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags) +{ + struct mptcp_subflow_context *subflow, *tmp; + struct sock *sk = (struct sock *)msk; - msk->write_seq = subflow->idsn + 1; - if (subflow->can_ack) { - msk->can_ack = true; - msk->remote_key = subflow->remote_key; - mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); - ack_seq++; - msk->ack_seq = ack_seq; - } - newsk = new_mptcp_sock; - mptcp_copy_inaddrs(newsk, ssk); - list_add(&subflow->node, &msk->conn_list); + __mptcp_clear_xmit(sk); - /* will be fully established at mptcp_stream_accept() - * completion. - */ - inet_sk_state_store(new_mptcp_sock, TCP_SYN_RECV); - bh_unlock_sock(new_mptcp_sock); - local_bh_enable(); - release_sock(sk); + /* join list will be eventually flushed (with rst) at sock lock release time */ + mptcp_for_each_subflow_safe(msk, subflow, tmp) + __mptcp_close_ssk(sk, mptcp_subflow_tcp_sock(subflow), subflow, flags); - /* the subflow can already receive packet, avoid racing with - * the receive path and process the pending ones - */ - lock_sock(ssk); - subflow->rel_write_seq = 1; - subflow->tcp_sock = ssk; - subflow->conn = new_mptcp_sock; - if (unlikely(!skb_queue_empty(&ssk->sk_receive_queue))) - mptcp_subflow_data_available(ssk); - release_sock(ssk); - } + /* move to sk_receive_queue, sk_stream_kill_queues will purge it */ + mptcp_data_lock(sk); + skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue); + __skb_queue_purge(&sk->sk_receive_queue); + skb_rbtree_purge(&msk->out_of_order_queue); + mptcp_data_unlock(sk); - return newsk; + /* move all the rx fwd alloc into the sk_mem_reclaim_final in + * inet_sock_destruct() will dispose it + */ + sk->sk_forward_alloc += msk->rmem_fwd_alloc; + msk->rmem_fwd_alloc = 0; + mptcp_token_destroy(msk); + mptcp_pm_free_anno_list(msk); + mptcp_free_local_addr_list(msk); } static void mptcp_destroy(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); - if (msk->cached_ext) - __skb_ext_put(msk->cached_ext); + /* clears msk->subflow, allowing the following to close + * even the initial subflow + */ + mptcp_dispose_initial_subflow(msk); + mptcp_destroy_common(msk, 0); + sk_sockets_allocated_dec(sk); } -static int mptcp_setsockopt(struct sock *sk, int level, int optname, - char __user *optval, unsigned int optlen) +void __mptcp_data_acked(struct sock *sk) { - struct mptcp_sock *msk = mptcp_sk(sk); - struct socket *ssock; + if (!sock_owned_by_user(sk)) + __mptcp_clean_una(sk); + else + __set_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->cb_flags); - pr_debug("msk=%p", msk); + if (mptcp_pending_data_fin_ack(sk)) + mptcp_schedule_work(sk); +} - /* @@ the meaning of setsockopt() when the socket is connected and - * there are multiple subflows is not yet defined. It is up to the - * MPTCP-level socket to configure the subflows until the subflow - * is in TCP fallback, when TCP socket options are passed through - * to the one remaining subflow. - */ - lock_sock(sk); - ssock = __mptcp_tcp_fallback(msk); - if (ssock) - return tcp_setsockopt(ssock->sk, level, optname, optval, - optlen); +void __mptcp_check_push(struct sock *sk, struct sock *ssk) +{ + if (!mptcp_send_head(sk)) + return; - release_sock(sk); + if (!sock_owned_by_user(sk)) { + struct sock *xmit_ssk = mptcp_subflow_get_send(mptcp_sk(sk)); - return -EOPNOTSUPP; + if (xmit_ssk == ssk) + __mptcp_subflow_push_pending(sk, ssk); + else if (xmit_ssk) + mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk), MPTCP_DELEGATE_SEND); + } else { + __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags); + } } -static int mptcp_getsockopt(struct sock *sk, int level, int optname, - char __user *optval, int __user *option) +#define MPTCP_FLAGS_PROCESS_CTX_NEED (BIT(MPTCP_PUSH_PENDING) | \ + BIT(MPTCP_RETRANSMIT) | \ + BIT(MPTCP_FLUSH_JOIN_LIST)) + +/* processes deferred events and flush wmem */ +static void mptcp_release_cb(struct sock *sk) + __must_hold(&sk->sk_lock.slock) { struct mptcp_sock *msk = mptcp_sk(sk); - struct socket *ssock; - pr_debug("msk=%p", msk); + for (;;) { + unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED) | + msk->push_pending; + if (!flags) + break; - /* @@ the meaning of setsockopt() when the socket is connected and - * there are multiple subflows is not yet defined. It is up to the - * MPTCP-level socket to configure the subflows until the subflow - * is in TCP fallback, when socket options are passed through - * to the one remaining subflow. - */ - lock_sock(sk); - ssock = __mptcp_tcp_fallback(msk); - if (ssock) - return tcp_getsockopt(ssock->sk, level, optname, optval, - option); + /* the following actions acquire the subflow socket lock + * + * 1) can't be invoked in atomic scope + * 2) must avoid ABBA deadlock with msk socket spinlock: the RX + * datapath acquires the msk socket spinlock while helding + * the subflow socket lock + */ + msk->push_pending = 0; + msk->cb_flags &= ~flags; + spin_unlock_bh(&sk->sk_lock.slock); + if (flags & BIT(MPTCP_FLUSH_JOIN_LIST)) + __mptcp_flush_join_list(sk); + if (flags & BIT(MPTCP_PUSH_PENDING)) + __mptcp_push_pending(sk, 0); + if (flags & BIT(MPTCP_RETRANSMIT)) + __mptcp_retrans(sk); + + cond_resched(); + spin_lock_bh(&sk->sk_lock.slock); + } - release_sock(sk); + if (__test_and_clear_bit(MPTCP_CLEAN_UNA, &msk->cb_flags)) + __mptcp_clean_una_wakeup(sk); + if (unlikely(&msk->cb_flags)) { + /* be sure to set the current sk state before tacking actions + * depending on sk_state, that is processing MPTCP_ERROR_REPORT + */ + if (__test_and_clear_bit(MPTCP_CONNECTED, &msk->cb_flags)) + __mptcp_set_connected(sk); + if (__test_and_clear_bit(MPTCP_ERROR_REPORT, &msk->cb_flags)) + __mptcp_error_report(sk); + if (__test_and_clear_bit(MPTCP_RESET_SCHEDULER, &msk->cb_flags)) + msk->last_snd = NULL; + } + + __mptcp_update_rmem(sk); +} + +/* MP_JOIN client subflow must wait for 4th ack before sending any data: + * TCP can't schedule delack timer before the subflow is fully established. + * MPTCP uses the delack timer to do 3rd ack retransmissions + */ +static void schedule_3rdack_retransmission(struct sock *ssk) +{ + struct inet_connection_sock *icsk = inet_csk(ssk); + struct tcp_sock *tp = tcp_sk(ssk); + unsigned long timeout; + + if (mptcp_subflow_ctx(ssk)->fully_established) + return; - return -EOPNOTSUPP; + /* reschedule with a timeout above RTT, as we must look only for drop */ + if (tp->srtt_us) + timeout = usecs_to_jiffies(tp->srtt_us >> (3 - 1)); + else + timeout = TCP_TIMEOUT_INIT; + timeout += jiffies; + + WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER); + icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; + icsk->icsk_ack.timeout = timeout; + sk_reset_timer(ssk, &icsk->icsk_delack_timer, timeout); +} + +void mptcp_subflow_process_delegated(struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct sock *sk = subflow->conn; + + if (test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) { + mptcp_data_lock(sk); + if (!sock_owned_by_user(sk)) + __mptcp_subflow_push_pending(sk, ssk); + else + __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags); + mptcp_data_unlock(sk); + mptcp_subflow_delegated_done(subflow, MPTCP_DELEGATE_SEND); + } + if (test_bit(MPTCP_DELEGATE_ACK, &subflow->delegated_status)) { + schedule_3rdack_retransmission(ssk); + mptcp_subflow_delegated_done(subflow, MPTCP_DELEGATE_ACK); + } +} + +static int mptcp_hash(struct sock *sk) +{ + /* should never be called, + * we hash the TCP subflows not the master socket + */ + WARN_ON_ONCE(1); + return 0; +} + +static void mptcp_unhash(struct sock *sk) +{ + /* called from sk_common_release(), but nothing to do here */ } static int mptcp_get_port(struct sock *sk, unsigned short snum) @@ -828,10 +3365,6 @@ void mptcp_finish_connect(struct sock *ssk) u64 ack_seq; subflow = mptcp_subflow_ctx(ssk); - - if (!subflow->mp_capable) - return; - sk = subflow->conn; msk = mptcp_sk(sk); @@ -841,20 +3374,25 @@ void mptcp_finish_connect(struct sock *ssk) ack_seq++; subflow->map_seq = ack_seq; subflow->map_subflow_seq = 1; - subflow->rel_write_seq = 1; /* the socket is not connected yet, no msk/subflow ops can access/race * accessing the field below */ WRITE_ONCE(msk->remote_key, subflow->remote_key); WRITE_ONCE(msk->local_key, subflow->local_key); - WRITE_ONCE(msk->token, subflow->token); WRITE_ONCE(msk->write_seq, subflow->idsn + 1); + WRITE_ONCE(msk->snd_nxt, msk->write_seq); WRITE_ONCE(msk->ack_seq, ack_seq); WRITE_ONCE(msk->can_ack, 1); + WRITE_ONCE(msk->snd_una, msk->write_seq); + atomic64_set(&msk->rcv_wnd_sent, ack_seq); + + mptcp_pm_new_connection(msk, ssk, 0); + + mptcp_rcv_space_init(msk, ssk); } -static void mptcp_sock_graft(struct sock *sk, struct socket *parent) +void mptcp_sock_graft(struct sock *sk, struct socket *parent) { write_lock_bh(&sk->sk_callback_lock); rcu_assign_pointer(sk->sk_wq, &parent->wq); @@ -863,30 +3401,227 @@ static void mptcp_sock_graft(struct sock *sk, struct socket *parent) write_unlock_bh(&sk->sk_callback_lock); } -static bool mptcp_memory_free(const struct sock *sk, int wake) +bool mptcp_finish_join(struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct mptcp_sock *msk = mptcp_sk(subflow->conn); + struct sock *parent = (void *)msk; + bool ret = true; + + pr_debug("msk=%p, subflow=%p", msk, subflow); + + /* mptcp socket already closing? */ + if (!mptcp_is_fully_established(parent)) { + subflow->reset_reason = MPTCP_RST_EMPTCP; + return false; + } + + if (!list_empty(&subflow->node)) + goto out; + + if (!mptcp_pm_allow_new_subflow(msk)) + goto err_prohibited; + + /* active connections are already on conn_list. + * If we can't acquire msk socket lock here, let the release callback + * handle it + */ + mptcp_data_lock(parent); + if (!sock_owned_by_user(parent)) { + ret = __mptcp_finish_join(msk, ssk); + if (ret) { + sock_hold(ssk); + list_add_tail(&subflow->node, &msk->conn_list); + } + } else { + sock_hold(ssk); + list_add_tail(&subflow->node, &msk->join_list); + __set_bit(MPTCP_FLUSH_JOIN_LIST, &msk->cb_flags); + } + mptcp_data_unlock(parent); + + if (!ret) { +err_prohibited: + subflow->reset_reason = MPTCP_RST_EPROHIBIT; + return false; + } + + subflow->map_seq = READ_ONCE(msk->ack_seq); + WRITE_ONCE(msk->allow_infinite_fallback, false); + +out: + mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC); + return true; +} + +static void mptcp_shutdown(struct sock *sk, int how) +{ + pr_debug("sk=%p, how=%d", sk, how); + + if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk)) + __mptcp_wr_shutdown(sk); +} + +static int mptcp_forward_alloc_get(const struct sock *sk) +{ + return sk->sk_forward_alloc + mptcp_sk(sk)->rmem_fwd_alloc; +} + +static int mptcp_ioctl_outq(const struct mptcp_sock *msk, u64 v) +{ + const struct sock *sk = (void *)msk; + u64 delta; + + if (sk->sk_state == TCP_LISTEN) + return -EINVAL; + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) + return 0; + + delta = msk->write_seq - v; + if (__mptcp_check_fallback(msk) && msk->first) { + struct tcp_sock *tp = tcp_sk(msk->first); + + /* the first subflow is disconnected after close - see + * __mptcp_close_ssk(). tcp_disconnect() moves the write_seq + * so ignore that status, too. + */ + if (!((1 << msk->first->sk_state) & + (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))) + delta += READ_ONCE(tp->write_seq) - tp->snd_una; + } + if (delta > INT_MAX) + delta = INT_MAX; + + return (int)delta; +} + +static int mptcp_ioctl(struct sock *sk, int cmd, unsigned long arg) { struct mptcp_sock *msk = mptcp_sk(sk); + bool slow; + int answ; - return wake ? test_bit(MPTCP_SEND_SPACE, &msk->flags) : true; + switch (cmd) { + case SIOCINQ: + if (sk->sk_state == TCP_LISTEN) + return -EINVAL; + + lock_sock(sk); + __mptcp_move_skbs(msk); + answ = mptcp_inq_hint(sk); + release_sock(sk); + break; + case SIOCOUTQ: + slow = lock_sock_fast(sk); + answ = mptcp_ioctl_outq(msk, READ_ONCE(msk->snd_una)); + unlock_sock_fast(sk, slow); + break; + case SIOCOUTQNSD: + slow = lock_sock_fast(sk); + answ = mptcp_ioctl_outq(msk, msk->snd_nxt); + unlock_sock_fast(sk, slow); + break; + default: + return -ENOIOCTLCMD; + } + + return put_user(answ, (int __user *)arg); +} + +static void mptcp_subflow_early_fallback(struct mptcp_sock *msk, + struct mptcp_subflow_context *subflow) +{ + subflow->request_mptcp = 0; + __mptcp_do_fallback(msk); +} + +static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk = mptcp_sk(sk); + struct socket *ssock; + int err = -EINVAL; + + ssock = __mptcp_nmpc_socket(msk); + if (!ssock) + return -EINVAL; + + mptcp_token_destroy(msk); + inet_sk_state_store(sk, TCP_SYN_SENT); + subflow = mptcp_subflow_ctx(ssock->sk); +#ifdef CONFIG_TCP_MD5SIG + /* no MPTCP if MD5SIG is enabled on this socket or we may run out of + * TCP option space. + */ + if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) + mptcp_subflow_early_fallback(msk, subflow); +#endif + if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) { + MPTCP_INC_STATS(sock_net(ssock->sk), MPTCP_MIB_TOKENFALLBACKINIT); + mptcp_subflow_early_fallback(msk, subflow); + } + if (likely(!__mptcp_check_fallback(msk))) + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVE); + + /* if reaching here via the fastopen/sendmsg path, the caller already + * acquired the subflow socket lock, too. + */ + if (msk->is_sendmsg) + err = __inet_stream_connect(ssock, uaddr, addr_len, msk->connect_flags, 1); + else + err = inet_stream_connect(ssock, uaddr, addr_len, msk->connect_flags); + inet_sk(sk)->defer_connect = inet_sk(ssock->sk)->defer_connect; + + /* on successful connect, the msk state will be moved to established by + * subflow_finish_connect() + */ + if (unlikely(err && err != -EINPROGRESS)) { + inet_sk_state_store(sk, inet_sk_state_load(ssock->sk)); + return err; + } + + mptcp_copy_inaddrs(sk, ssock->sk); + + /* unblocking connect, mptcp-level inet_stream_connect will error out + * without changing the socket state, update it here. + */ + if (err == -EINPROGRESS) + sk->sk_socket->state = ssock->state; + return err; } static struct proto mptcp_prot = { .name = "MPTCP", .owner = THIS_MODULE, .init = mptcp_init_sock, + .connect = mptcp_connect, + .disconnect = mptcp_disconnect, .close = mptcp_close, .accept = mptcp_accept, .setsockopt = mptcp_setsockopt, .getsockopt = mptcp_getsockopt, - .shutdown = tcp_shutdown, + .shutdown = mptcp_shutdown, .destroy = mptcp_destroy, .sendmsg = mptcp_sendmsg, + .ioctl = mptcp_ioctl, .recvmsg = mptcp_recvmsg, - .hash = inet_hash, - .unhash = inet_unhash, + .release_cb = mptcp_release_cb, + .hash = mptcp_hash, + .unhash = mptcp_unhash, .get_port = mptcp_get_port, - .stream_memory_free = mptcp_memory_free, + .forward_alloc_get = mptcp_forward_alloc_get, + .sockets_allocated = &mptcp_sockets_allocated, + + .memory_allocated = &tcp_memory_allocated, + .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc, + + .memory_pressure = &tcp_memory_pressure, + .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), + .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), + .sysctl_mem = sysctl_tcp_mem, .obj_size = sizeof(struct mptcp_sock), + .slab_flags = SLAB_TYPESAFE_BY_RCU, .no_autobind = true, }; @@ -897,9 +3632,9 @@ static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) int err; lock_sock(sock->sk); - ssock = __mptcp_socket_create(msk, MPTCP_SAME_STATE); - if (IS_ERR(ssock)) { - err = PTR_ERR(ssock); + ssock = __mptcp_nmpc_socket(msk); + if (!ssock) { + err = -EINVAL; goto unlock; } @@ -915,69 +3650,14 @@ unlock: static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags) { - struct mptcp_sock *msk = mptcp_sk(sock->sk); - struct socket *ssock; - int err; + int ret; lock_sock(sock->sk); - ssock = __mptcp_socket_create(msk, TCP_SYN_SENT); - if (IS_ERR(ssock)) { - err = PTR_ERR(ssock); - goto unlock; - } - -#ifdef CONFIG_TCP_MD5SIG - /* no MPTCP if MD5SIG is enabled on this socket or we may run out of - * TCP option space. - */ - if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) - mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0; -#endif - - err = ssock->ops->connect(ssock, uaddr, addr_len, flags); - inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); - mptcp_copy_inaddrs(sock->sk, ssock->sk); - -unlock: + mptcp_sk(sock->sk)->connect_flags = flags; + ret = __inet_stream_connect(sock, uaddr, addr_len, flags, 0); release_sock(sock->sk); - return err; -} - -static int mptcp_v4_getname(struct socket *sock, struct sockaddr *uaddr, - int peer) -{ - if (sock->sk->sk_prot == &tcp_prot) { - /* we are being invoked from __sys_accept4, after - * mptcp_accept() has just accepted a non-mp-capable - * flow: sk is a tcp_sk, not an mptcp one. - * - * Hand the socket over to tcp so all further socket ops - * bypass mptcp. - */ - sock->ops = &inet_stream_ops; - } - - return inet_getname(sock, uaddr, peer); -} - -#if IS_ENABLED(CONFIG_MPTCP_IPV6) -static int mptcp_v6_getname(struct socket *sock, struct sockaddr *uaddr, - int peer) -{ - if (sock->sk->sk_prot == &tcpv6_prot) { - /* we are being invoked from __sys_accept4 after - * mptcp_accept() has accepted a non-mp-capable - * subflow: sk is a tcp_sk, not mptcp. - * - * Hand the socket over to tcp so all further - * socket ops bypass mptcp. - */ - sock->ops = &inet6_stream_ops; - } - - return inet6_getname(sock, uaddr, peer); + return ret; } -#endif static int mptcp_listen(struct socket *sock, int backlog) { @@ -988,12 +3668,16 @@ static int mptcp_listen(struct socket *sock, int backlog) pr_debug("msk=%p", msk); lock_sock(sock->sk); - ssock = __mptcp_socket_create(msk, TCP_LISTEN); - if (IS_ERR(ssock)) { - err = PTR_ERR(ssock); + ssock = __mptcp_nmpc_socket(msk); + if (!ssock) { + err = -EINVAL; goto unlock; } + mptcp_token_destroy(msk); + inet_sk_state_store(sock->sk, TCP_LISTEN); + sock_set_flag(sock->sk, SOCK_RCU_FREE); + err = ssock->ops->listen(ssock, backlog); inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); if (!err) @@ -1004,15 +3688,6 @@ unlock: return err; } -static bool is_tcp_proto(const struct proto *p) -{ -#if IS_ENABLED(CONFIG_MPTCP_IPV6) - return p == &tcp_prot || p == &tcpv6_prot; -#else - return p == &tcp_prot; -#endif -} - static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, int flags, bool kern) { @@ -1022,41 +3697,65 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, pr_debug("msk=%p", msk); - lock_sock(sock->sk); - if (sock->sk->sk_state != TCP_LISTEN) - goto unlock_fail; - ssock = __mptcp_nmpc_socket(msk); if (!ssock) - goto unlock_fail; - - sock_hold(ssock->sk); - release_sock(sock->sk); + return -EINVAL; err = ssock->ops->accept(sock, newsock, flags, kern); - if (err == 0 && !is_tcp_proto(newsock->sk->sk_prot)) { + if (err == 0 && !mptcp_is_tcpsk(newsock->sk)) { struct mptcp_sock *msk = mptcp_sk(newsock->sk); struct mptcp_subflow_context *subflow; + struct sock *newsk = newsock->sk; + + lock_sock(newsk); + + /* PM/worker can now acquire the first subflow socket + * lock without racing with listener queue cleanup, + * we can notify it, if needed. + * + * Even if remote has reset the initial subflow by now + * the refcnt is still at least one. + */ + subflow = mptcp_subflow_ctx(msk->first); + list_add(&subflow->node, &msk->conn_list); + sock_hold(msk->first); + if (mptcp_is_fully_established(newsk)) + mptcp_pm_fully_established(msk, msk->first, GFP_KERNEL); + + mptcp_rcv_space_init(msk, msk->first); + mptcp_propagate_sndbuf(newsk, msk->first); /* set ssk->sk_socket of accept()ed flows to mptcp socket. * This is needed so NOSPACE flag can be set from tcp stack. */ - list_for_each_entry(subflow, &msk->conn_list, node) { + mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); if (!ssk->sk_socket) mptcp_sock_graft(ssk, newsock); } - - inet_sk_state_store(newsock->sk, TCP_ESTABLISHED); + release_sock(newsk); } - sock_put(ssock->sk); return err; +} -unlock_fail: - release_sock(sock->sk); - return -EINVAL; +static __poll_t mptcp_check_writeable(struct mptcp_sock *msk) +{ + struct sock *sk = (struct sock *)msk; + + if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) + return EPOLLOUT | EPOLLWRNORM; + + if (sk_stream_is_writeable(sk)) + return EPOLLOUT | EPOLLWRNORM; + + mptcp_set_nospace(sk); + smp_mb__after_atomic(); /* msk->flags is changed by write_space cb */ + if (sk_stream_is_writeable(sk)) + return EPOLLOUT | EPOLLWRNORM; + + return 0; } static __poll_t mptcp_poll(struct file *file, struct socket *sock, @@ -1064,76 +3763,39 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock, { struct sock *sk = sock->sk; struct mptcp_sock *msk; - struct socket *ssock; __poll_t mask = 0; + int state; msk = mptcp_sk(sk); - lock_sock(sk); - ssock = __mptcp_nmpc_socket(msk); - if (ssock) { - mask = ssock->ops->poll(file, ssock, wait); - release_sock(sk); - return mask; - } - - release_sock(sk); sock_poll_wait(file, sock, wait); - lock_sock(sk); - ssock = __mptcp_tcp_fallback(msk); - if (unlikely(ssock)) - return ssock->ops->poll(file, ssock, NULL); - - if (test_bit(MPTCP_DATA_READY, &msk->flags)) - mask = EPOLLIN | EPOLLRDNORM; - if (sk_stream_is_writeable(sk) && - test_bit(MPTCP_SEND_SPACE, &msk->flags)) - mask |= EPOLLOUT | EPOLLWRNORM; - if (sk->sk_shutdown & RCV_SHUTDOWN) - mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; - - release_sock(sk); - - return mask; -} -static int mptcp_shutdown(struct socket *sock, int how) -{ - struct mptcp_sock *msk = mptcp_sk(sock->sk); - struct mptcp_subflow_context *subflow; - int ret = 0; - - pr_debug("sk=%p, how=%d", msk, how); - - lock_sock(sock->sk); - - if (how == SHUT_WR || how == SHUT_RDWR) - inet_sk_state_store(sock->sk, TCP_FIN_WAIT1); - - how++; - - if ((how & ~SHUTDOWN_MASK) || !how) { - ret = -EINVAL; - goto out_unlock; - } + state = inet_sk_state_load(sk); + pr_debug("msk=%p state=%d flags=%lx", msk, state, msk->flags); + if (state == TCP_LISTEN) { + if (WARN_ON_ONCE(!msk->subflow || !msk->subflow->sk)) + return 0; - if (sock->state == SS_CONNECTING) { - if ((1 << sock->sk->sk_state) & - (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)) - sock->state = SS_DISCONNECTING; - else - sock->state = SS_CONNECTED; + return inet_csk_listen_poll(msk->subflow->sk); } - mptcp_for_each_subflow(msk, subflow) { - struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); - - mptcp_subflow_shutdown(tcp_sk, how); + if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) { + mask |= mptcp_check_readable(msk); + mask |= mptcp_check_writeable(msk); + } else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) { + /* cf tcp_poll() note about TFO */ + mask |= EPOLLOUT | EPOLLWRNORM; } + if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE) + mask |= EPOLLHUP; + if (sk->sk_shutdown & RCV_SHUTDOWN) + mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; -out_unlock: - release_sock(sock->sk); + /* This barrier is coupled with smp_wmb() in __mptcp_error_report() */ + smp_rmb(); + if (sk->sk_err) + mask |= EPOLLERR; - return ret; + return mask; } static const struct proto_ops mptcp_stream_ops = { @@ -1144,22 +3806,18 @@ static const struct proto_ops mptcp_stream_ops = { .connect = mptcp_stream_connect, .socketpair = sock_no_socketpair, .accept = mptcp_stream_accept, - .getname = mptcp_v4_getname, + .getname = inet_getname, .poll = mptcp_poll, .ioctl = inet_ioctl, .gettstamp = sock_gettstamp, .listen = mptcp_listen, - .shutdown = mptcp_shutdown, + .shutdown = inet_shutdown, .setsockopt = sock_common_setsockopt, .getsockopt = sock_common_getsockopt, .sendmsg = inet_sendmsg, .recvmsg = inet_recvmsg, .mmap = sock_no_mmap, .sendpage = inet_sendpage, -#ifdef CONFIG_COMPAT - .compat_setsockopt = compat_sock_common_setsockopt, - .compat_getsockopt = compat_sock_common_getsockopt, -#endif }; static struct inet_protosw mptcp_protosw = { @@ -1170,16 +3828,68 @@ static struct inet_protosw mptcp_protosw = { .flags = INET_PROTOSW_ICSK, }; -void mptcp_proto_init(void) +static int mptcp_napi_poll(struct napi_struct *napi, int budget) +{ + struct mptcp_delegated_action *delegated; + struct mptcp_subflow_context *subflow; + int work_done = 0; + + delegated = container_of(napi, struct mptcp_delegated_action, napi); + while ((subflow = mptcp_subflow_delegated_next(delegated)) != NULL) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + bh_lock_sock_nested(ssk); + if (!sock_owned_by_user(ssk) && + mptcp_subflow_has_delegated_action(subflow)) + mptcp_subflow_process_delegated(ssk); + /* ... elsewhere tcp_release_cb_override already processed + * the action or will do at next release_sock(). + * In both case must dequeue the subflow here - on the same + * CPU that scheduled it. + */ + bh_unlock_sock(ssk); + sock_put(ssk); + + if (++work_done == budget) + return budget; + } + + /* always provide a 0 'work_done' argument, so that napi_complete_done + * will not try accessing the NULL napi->dev ptr + */ + napi_complete_done(napi, 0); + return work_done; +} + +void __init mptcp_proto_init(void) { + struct mptcp_delegated_action *delegated; + int cpu; + mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo; + if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL)) + panic("Failed to allocate MPTCP pcpu counter\n"); + + init_dummy_netdev(&mptcp_napi_dev); + for_each_possible_cpu(cpu) { + delegated = per_cpu_ptr(&mptcp_delegated_actions, cpu); + INIT_LIST_HEAD(&delegated->head); + netif_napi_add_tx(&mptcp_napi_dev, &delegated->napi, + mptcp_napi_poll); + napi_enable(&delegated->napi); + } + mptcp_subflow_init(); + mptcp_pm_init(); + mptcp_token_init(); if (proto_register(&mptcp_prot, 1) != 0) panic("Failed to register MPTCP proto.\n"); inet_register_protosw(&mptcp_protosw); + + BUILD_BUG_ON(sizeof(struct mptcp_skb_cb) > sizeof_field(struct sk_buff, cb)); } #if IS_ENABLED(CONFIG_MPTCP_IPV6) @@ -1191,12 +3901,12 @@ static const struct proto_ops mptcp_v6_stream_ops = { .connect = mptcp_stream_connect, .socketpair = sock_no_socketpair, .accept = mptcp_stream_accept, - .getname = mptcp_v6_getname, + .getname = inet6_getname, .poll = mptcp_poll, .ioctl = inet6_ioctl, .gettstamp = sock_gettstamp, .listen = mptcp_listen, - .shutdown = mptcp_shutdown, + .shutdown = inet_shutdown, .setsockopt = sock_common_setsockopt, .getsockopt = sock_common_getsockopt, .sendmsg = inet6_sendmsg, @@ -1204,8 +3914,7 @@ static const struct proto_ops mptcp_v6_stream_ops = { .mmap = sock_no_mmap, .sendpage = inet_sendpage, #ifdef CONFIG_COMPAT - .compat_setsockopt = compat_sock_common_setsockopt, - .compat_getsockopt = compat_sock_common_getsockopt, + .compat_ioctl = inet6_compat_ioctl, #endif }; @@ -1225,7 +3934,7 @@ static struct inet_protosw mptcp_v6_protosw = { .flags = INET_PROTOSW_ICSK, }; -int mptcp_proto_v6_init(void) +int __init mptcp_proto_v6_init(void) { int err; |