4054 lines
102 KiB
C
4054 lines
102 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Multipath TCP
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*
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* Copyright (c) 2017 - 2019, Intel Corporation.
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*/
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#define pr_fmt(fmt) "MPTCP: " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/sched/signal.h>
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#include <linux/atomic.h>
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#include <net/sock.h>
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#include <net/inet_common.h>
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#include <net/inet_hashtables.h>
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#include <net/protocol.h>
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#include <net/tcp.h>
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#include <net/tcp_states.h>
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#if IS_ENABLED(CONFIG_MPTCP_IPV6)
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#include <net/transp_v6.h>
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#endif
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#include <net/mptcp.h>
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#include <net/xfrm.h>
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#include <asm/ioctls.h>
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#include "protocol.h"
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#include "mib.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/mptcp.h>
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#if IS_ENABLED(CONFIG_MPTCP_IPV6)
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struct mptcp6_sock {
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struct mptcp_sock msk;
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struct ipv6_pinfo np;
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};
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#endif
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struct mptcp_skb_cb {
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u64 map_seq;
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u64 end_seq;
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u32 offset;
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u8 has_rxtstamp:1;
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};
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#define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0]))
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enum {
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MPTCP_CMSG_TS = BIT(0),
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MPTCP_CMSG_INQ = BIT(1),
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};
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static struct percpu_counter mptcp_sockets_allocated ____cacheline_aligned_in_smp;
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static void __mptcp_destroy_sock(struct sock *sk);
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static void mptcp_check_send_data_fin(struct sock *sk);
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DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
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static struct net_device mptcp_napi_dev;
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/* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not
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* completed yet or has failed, return the subflow socket.
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* Otherwise return NULL.
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*/
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struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk)
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{
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if (!msk->subflow || READ_ONCE(msk->can_ack))
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return NULL;
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return msk->subflow;
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}
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/* Returns end sequence number of the receiver's advertised window */
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static u64 mptcp_wnd_end(const struct mptcp_sock *msk)
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{
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return READ_ONCE(msk->wnd_end);
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}
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static bool mptcp_is_tcpsk(struct sock *sk)
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{
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struct socket *sock = sk->sk_socket;
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if (unlikely(sk->sk_prot == &tcp_prot)) {
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/* we are being invoked after mptcp_accept() has
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* accepted a non-mp-capable flow: sk is a tcp_sk,
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* not an mptcp one.
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*
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* Hand the socket over to tcp so all further socket ops
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* bypass mptcp.
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*/
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sock->ops = &inet_stream_ops;
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return true;
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#if IS_ENABLED(CONFIG_MPTCP_IPV6)
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} else if (unlikely(sk->sk_prot == &tcpv6_prot)) {
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sock->ops = &inet6_stream_ops;
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return true;
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#endif
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}
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return false;
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}
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static int __mptcp_socket_create(struct mptcp_sock *msk)
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{
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struct mptcp_subflow_context *subflow;
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struct sock *sk = (struct sock *)msk;
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struct socket *ssock;
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int err;
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err = mptcp_subflow_create_socket(sk, sk->sk_family, &ssock);
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if (err)
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return err;
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WRITE_ONCE(msk->first, ssock->sk);
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WRITE_ONCE(msk->subflow, ssock);
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subflow = mptcp_subflow_ctx(ssock->sk);
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list_add(&subflow->node, &msk->conn_list);
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sock_hold(ssock->sk);
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subflow->request_mptcp = 1;
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/* This is the first subflow, always with id 0 */
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subflow->local_id_valid = 1;
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mptcp_sock_graft(msk->first, sk->sk_socket);
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return 0;
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}
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static void mptcp_drop(struct sock *sk, struct sk_buff *skb)
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{
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sk_drops_add(sk, skb);
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__kfree_skb(skb);
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}
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static void mptcp_rmem_fwd_alloc_add(struct sock *sk, int size)
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{
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WRITE_ONCE(mptcp_sk(sk)->rmem_fwd_alloc,
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mptcp_sk(sk)->rmem_fwd_alloc + size);
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}
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static void mptcp_rmem_charge(struct sock *sk, int size)
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{
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mptcp_rmem_fwd_alloc_add(sk, -size);
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}
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static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to,
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struct sk_buff *from)
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{
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bool fragstolen;
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int delta;
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if (MPTCP_SKB_CB(from)->offset ||
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!skb_try_coalesce(to, from, &fragstolen, &delta))
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return false;
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pr_debug("colesced seq %llx into %llx new len %d new end seq %llx",
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MPTCP_SKB_CB(from)->map_seq, MPTCP_SKB_CB(to)->map_seq,
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to->len, MPTCP_SKB_CB(from)->end_seq);
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MPTCP_SKB_CB(to)->end_seq = MPTCP_SKB_CB(from)->end_seq;
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/* note the fwd memory can reach a negative value after accounting
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* for the delta, but the later skb free will restore a non
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* negative one
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*/
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atomic_add(delta, &sk->sk_rmem_alloc);
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mptcp_rmem_charge(sk, delta);
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kfree_skb_partial(from, fragstolen);
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return true;
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}
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static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to,
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struct sk_buff *from)
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{
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if (MPTCP_SKB_CB(from)->map_seq != MPTCP_SKB_CB(to)->end_seq)
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return false;
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return mptcp_try_coalesce((struct sock *)msk, to, from);
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}
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static void __mptcp_rmem_reclaim(struct sock *sk, int amount)
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{
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amount >>= PAGE_SHIFT;
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mptcp_rmem_charge(sk, amount << PAGE_SHIFT);
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__sk_mem_reduce_allocated(sk, amount);
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}
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static void mptcp_rmem_uncharge(struct sock *sk, int size)
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{
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struct mptcp_sock *msk = mptcp_sk(sk);
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int reclaimable;
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mptcp_rmem_fwd_alloc_add(sk, size);
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reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
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/* see sk_mem_uncharge() for the rationale behind the following schema */
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if (unlikely(reclaimable >= PAGE_SIZE))
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__mptcp_rmem_reclaim(sk, reclaimable);
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}
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static void mptcp_rfree(struct sk_buff *skb)
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{
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unsigned int len = skb->truesize;
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struct sock *sk = skb->sk;
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atomic_sub(len, &sk->sk_rmem_alloc);
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mptcp_rmem_uncharge(sk, len);
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}
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static void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk)
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{
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skb_orphan(skb);
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skb->sk = sk;
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skb->destructor = mptcp_rfree;
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atomic_add(skb->truesize, &sk->sk_rmem_alloc);
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mptcp_rmem_charge(sk, skb->truesize);
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}
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/* "inspired" by tcp_data_queue_ofo(), main differences:
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* - use mptcp seqs
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* - don't cope with sacks
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*/
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static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb)
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{
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struct sock *sk = (struct sock *)msk;
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struct rb_node **p, *parent;
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u64 seq, end_seq, max_seq;
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struct sk_buff *skb1;
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seq = MPTCP_SKB_CB(skb)->map_seq;
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end_seq = MPTCP_SKB_CB(skb)->end_seq;
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max_seq = atomic64_read(&msk->rcv_wnd_sent);
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pr_debug("msk=%p seq=%llx limit=%llx empty=%d", msk, seq, max_seq,
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RB_EMPTY_ROOT(&msk->out_of_order_queue));
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if (after64(end_seq, max_seq)) {
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/* out of window */
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mptcp_drop(sk, skb);
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pr_debug("oow by %lld, rcv_wnd_sent %llu\n",
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(unsigned long long)end_seq - (unsigned long)max_seq,
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(unsigned long long)atomic64_read(&msk->rcv_wnd_sent));
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_NODSSWINDOW);
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return;
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}
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p = &msk->out_of_order_queue.rb_node;
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUE);
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if (RB_EMPTY_ROOT(&msk->out_of_order_queue)) {
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rb_link_node(&skb->rbnode, NULL, p);
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rb_insert_color(&skb->rbnode, &msk->out_of_order_queue);
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msk->ooo_last_skb = skb;
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goto end;
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}
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/* with 2 subflows, adding at end of ooo queue is quite likely
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* Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup.
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*/
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if (mptcp_ooo_try_coalesce(msk, msk->ooo_last_skb, skb)) {
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE);
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL);
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return;
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}
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/* Can avoid an rbtree lookup if we are adding skb after ooo_last_skb */
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if (!before64(seq, MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq)) {
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL);
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parent = &msk->ooo_last_skb->rbnode;
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p = &parent->rb_right;
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goto insert;
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}
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/* Find place to insert this segment. Handle overlaps on the way. */
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parent = NULL;
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while (*p) {
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parent = *p;
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skb1 = rb_to_skb(parent);
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if (before64(seq, MPTCP_SKB_CB(skb1)->map_seq)) {
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p = &parent->rb_left;
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continue;
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}
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if (before64(seq, MPTCP_SKB_CB(skb1)->end_seq)) {
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if (!after64(end_seq, MPTCP_SKB_CB(skb1)->end_seq)) {
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/* All the bits are present. Drop. */
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mptcp_drop(sk, skb);
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
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return;
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}
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if (after64(seq, MPTCP_SKB_CB(skb1)->map_seq)) {
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/* partial overlap:
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* | skb |
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* | skb1 |
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* continue traversing
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*/
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} else {
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/* skb's seq == skb1's seq and skb covers skb1.
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* Replace skb1 with skb.
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*/
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rb_replace_node(&skb1->rbnode, &skb->rbnode,
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&msk->out_of_order_queue);
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mptcp_drop(sk, skb1);
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
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goto merge_right;
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}
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} else if (mptcp_ooo_try_coalesce(msk, skb1, skb)) {
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE);
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return;
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}
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p = &parent->rb_right;
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}
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insert:
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/* Insert segment into RB tree. */
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rb_link_node(&skb->rbnode, parent, p);
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rb_insert_color(&skb->rbnode, &msk->out_of_order_queue);
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merge_right:
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/* Remove other segments covered by skb. */
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while ((skb1 = skb_rb_next(skb)) != NULL) {
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if (before64(end_seq, MPTCP_SKB_CB(skb1)->end_seq))
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break;
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rb_erase(&skb1->rbnode, &msk->out_of_order_queue);
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mptcp_drop(sk, skb1);
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
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}
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/* If there is no skb after us, we are the last_skb ! */
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if (!skb1)
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msk->ooo_last_skb = skb;
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end:
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skb_condense(skb);
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mptcp_set_owner_r(skb, sk);
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}
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static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
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{
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struct mptcp_sock *msk = mptcp_sk(sk);
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int amt, amount;
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if (size <= msk->rmem_fwd_alloc)
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return true;
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size -= msk->rmem_fwd_alloc;
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amt = sk_mem_pages(size);
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amount = amt << PAGE_SHIFT;
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if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV))
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return false;
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mptcp_rmem_fwd_alloc_add(sk, amount);
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return true;
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}
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static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
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struct sk_buff *skb, unsigned int offset,
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size_t copy_len)
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{
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struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
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struct sock *sk = (struct sock *)msk;
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struct sk_buff *tail;
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bool has_rxtstamp;
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__skb_unlink(skb, &ssk->sk_receive_queue);
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skb_ext_reset(skb);
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skb_orphan(skb);
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/* try to fetch required memory from subflow */
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if (!mptcp_rmem_schedule(sk, ssk, skb->truesize))
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goto drop;
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has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp;
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/* the skb map_seq accounts for the skb offset:
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* mptcp_subflow_get_mapped_dsn() is based on the current tp->copied_seq
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* value
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*/
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MPTCP_SKB_CB(skb)->map_seq = mptcp_subflow_get_mapped_dsn(subflow);
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MPTCP_SKB_CB(skb)->end_seq = MPTCP_SKB_CB(skb)->map_seq + copy_len;
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MPTCP_SKB_CB(skb)->offset = offset;
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MPTCP_SKB_CB(skb)->has_rxtstamp = has_rxtstamp;
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if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) {
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/* in sequence */
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WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len);
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tail = skb_peek_tail(&sk->sk_receive_queue);
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if (tail && mptcp_try_coalesce(sk, tail, skb))
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return true;
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mptcp_set_owner_r(skb, sk);
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__skb_queue_tail(&sk->sk_receive_queue, skb);
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return true;
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} else if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) {
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mptcp_data_queue_ofo(msk, skb);
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return false;
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}
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/* old data, keep it simple and drop the whole pkt, sender
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* will retransmit as needed, if needed.
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*/
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MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA);
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drop:
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mptcp_drop(sk, skb);
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return false;
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}
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static void mptcp_stop_timer(struct sock *sk)
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
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mptcp_sk(sk)->timer_ival = 0;
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}
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static void mptcp_close_wake_up(struct sock *sk)
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{
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if (sock_flag(sk, SOCK_DEAD))
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return;
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sk->sk_state_change(sk);
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if (sk->sk_shutdown == SHUTDOWN_MASK ||
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sk->sk_state == TCP_CLOSE)
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sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
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else
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sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
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}
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static bool mptcp_pending_data_fin_ack(struct sock *sk)
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{
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struct mptcp_sock *msk = mptcp_sk(sk);
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return ((1 << sk->sk_state) &
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(TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK)) &&
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msk->write_seq == READ_ONCE(msk->snd_una);
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}
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static void mptcp_check_data_fin_ack(struct sock *sk)
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{
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struct mptcp_sock *msk = mptcp_sk(sk);
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/* Look for an acknowledged DATA_FIN */
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if (mptcp_pending_data_fin_ack(sk)) {
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WRITE_ONCE(msk->snd_data_fin_enable, 0);
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switch (sk->sk_state) {
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case TCP_FIN_WAIT1:
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inet_sk_state_store(sk, TCP_FIN_WAIT2);
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break;
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case TCP_CLOSING:
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case TCP_LAST_ACK:
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inet_sk_state_store(sk, TCP_CLOSE);
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break;
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}
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|
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mptcp_close_wake_up(sk);
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}
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}
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static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq)
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{
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struct mptcp_sock *msk = mptcp_sk(sk);
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if (READ_ONCE(msk->rcv_data_fin) &&
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((1 << sk->sk_state) &
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(TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2))) {
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u64 rcv_data_fin_seq = READ_ONCE(msk->rcv_data_fin_seq);
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if (msk->ack_seq == rcv_data_fin_seq) {
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if (seq)
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*seq = rcv_data_fin_seq;
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return true;
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}
|
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}
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|
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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;
|
|
|
|
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) {
|
|
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
|
|
|
|
if (cleanup || mptcp_subflow_could_cleanup(ssk, rx_empty))
|
|
mptcp_subflow_cleanup_rbuf(ssk);
|
|
}
|
|
}
|
|
|
|
static bool mptcp_check_data_fin(struct sock *sk)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
u64 rcv_data_fin_seq;
|
|
bool ret = false;
|
|
|
|
/* 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);
|
|
|
|
WRITE_ONCE(sk->sk_shutdown, 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;
|
|
if (!__mptcp_check_fallback(msk))
|
|
mptcp_send_ack(msk);
|
|
mptcp_close_wake_up(sk);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
|
|
struct sock *ssk,
|
|
unsigned int *bytes)
|
|
{
|
|
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;
|
|
|
|
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 void mptcp_subflow_joined(struct mptcp_sock *msk, struct sock *ssk)
|
|
{
|
|
mptcp_subflow_ctx(ssk)->map_seq = READ_ONCE(msk->ack_seq);
|
|
WRITE_ONCE(msk->allow_infinite_fallback, false);
|
|
mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
|
|
}
|
|
|
|
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_sockopt_sync_locked(msk, ssk);
|
|
mptcp_subflow_joined(msk, ssk);
|
|
return true;
|
|
}
|
|
|
|
static void __mptcp_flush_join_list(struct sock *sk, struct list_head *join_list)
|
|
{
|
|
struct mptcp_subflow_context *tmp, *subflow;
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
|
|
list_for_each_entry_safe(subflow, tmp, 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
|
|
*/
|
|
WRITE_ONCE(sk->sk_shutdown, 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)
|
|
{
|
|
struct mptcp_subflow_context *subflow;
|
|
struct sock *sk = (struct sock *)msk;
|
|
|
|
sock_owned_by_me(sk);
|
|
|
|
mptcp_for_each_subflow(msk, subflow) {
|
|
if (READ_ONCE(subflow->data_avail))
|
|
return mptcp_subflow_tcp_sock(subflow);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
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 and this
|
|
* mapping has not been xmitted yet
|
|
*/
|
|
return mpext && mpext->data_seq + mpext->data_len == write_seq &&
|
|
!mpext->frozen;
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
struct mptcp_data_frag *dtmp, *dfrag;
|
|
u64 snd_una;
|
|
|
|
/* on fallback we just need to ignore snd_una, as this is really
|
|
* plain TCP
|
|
*/
|
|
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);
|
|
}
|
|
|
|
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
|
|
*/
|
|
mpext = skb_ext_find(skb, SKB_EXT_MPTCP);
|
|
if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) {
|
|
TCP_SKB_CB(skb)->eor = 1;
|
|
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);
|
|
}
|
|
|
|
/* 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);
|
|
|
|
if (snd_una != msk->snd_nxt) {
|
|
tcp_remove_empty_skb(ssk);
|
|
return 0;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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 = data_seq;
|
|
mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq;
|
|
mpext->data_len = copy;
|
|
mpext->use_map = 1;
|
|
mpext->dsn64 = 1;
|
|
|
|
pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d",
|
|
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:
|
|
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;
|
|
}
|
|
|
|
#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);
|
|
}
|
|
|
|
bool mptcp_subflow_active(struct mptcp_subflow_context *subflow)
|
|
{
|
|
if (unlikely(subflow->stale)) {
|
|
u32 rcv_tstamp = READ_ONCE(tcp_sk(mptcp_subflow_tcp_sock(subflow))->rcv_tstamp);
|
|
|
|
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
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/* 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_disconnect(struct sock *sk, int 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->fastopening = 1;
|
|
ret = tcp_sendmsg_fastopen(ssk, msg, copied_syn, len, NULL);
|
|
msk->fastopening = 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;
|
|
} else if (ret && ret != -EINPROGRESS) {
|
|
/* The disconnect() op called by tcp_sendmsg_fastopen()/
|
|
* __inet_stream_connect() can fail, due to looking check,
|
|
* see mptcp_disconnect().
|
|
* Attempt it again outside the problematic scope.
|
|
*/
|
|
if (!mptcp_disconnect(sk, 0))
|
|
sk->sk_socket->state = SS_UNCONNECTED;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
struct page_frag *pfrag;
|
|
struct socket *ssock;
|
|
size_t copied = 0;
|
|
int ret = 0;
|
|
long timeo;
|
|
|
|
/* 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_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);
|
|
|
|
if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {
|
|
ret = sk_stream_wait_connect(sk, &timeo);
|
|
if (ret)
|
|
goto do_error;
|
|
}
|
|
|
|
ret = -EPIPE;
|
|
if (unlikely(sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)))
|
|
goto do_error;
|
|
|
|
pfrag = sk_page_frag(sk);
|
|
|
|
while (msg_data_left(msg)) {
|
|
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;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/* data successfully copied into the write queue */
|
|
sk_forward_alloc_add(sk, -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;
|
|
}
|
|
|
|
if (copied)
|
|
__mptcp_push_pending(sk, msg->msg_flags);
|
|
|
|
out:
|
|
release_sock(sk);
|
|
return copied;
|
|
|
|
do_error:
|
|
if (copied)
|
|
goto out;
|
|
|
|
copied = sk_stream_error(sk, msg->msg_flags, ret);
|
|
goto out;
|
|
}
|
|
|
|
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 sk_buff *skb, *tmp;
|
|
int copied = 0;
|
|
|
|
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;
|
|
|
|
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);
|
|
}
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
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_splice_receive_queue(struct sock *sk)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(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;
|
|
}
|
|
|
|
if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
|
|
int flags, int *addr_len)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
struct scm_timestamping_internal tss;
|
|
int copied = 0, cmsg_flags = 0;
|
|
int target;
|
|
long timeo;
|
|
|
|
/* 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);
|
|
if (unlikely(sk->sk_state == TCP_LISTEN)) {
|
|
copied = -ENOTCONN;
|
|
goto out_err;
|
|
}
|
|
|
|
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
|
|
|
|
len = min_t(size_t, len, INT_MAX);
|
|
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
|
|
|
|
if (unlikely(msk->recvmsg_inq))
|
|
cmsg_flags = MPTCP_CMSG_INQ;
|
|
|
|
while (copied < len) {
|
|
int bytes_read;
|
|
|
|
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;
|
|
}
|
|
|
|
copied += bytes_read;
|
|
|
|
/* be sure to advertise window change */
|
|
mptcp_cleanup_rbuf(msk);
|
|
|
|
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()
|
|
*/
|
|
if (copied >= target)
|
|
break;
|
|
|
|
if (copied) {
|
|
if (sk->sk_err ||
|
|
sk->sk_state == TCP_CLOSE ||
|
|
(sk->sk_shutdown & RCV_SHUTDOWN) ||
|
|
!timeo ||
|
|
signal_pending(current))
|
|
break;
|
|
} else {
|
|
if (sk->sk_err) {
|
|
copied = sock_error(sk);
|
|
break;
|
|
}
|
|
|
|
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;
|
|
break;
|
|
}
|
|
|
|
if (!timeo) {
|
|
copied = -EAGAIN;
|
|
break;
|
|
}
|
|
|
|
if (signal_pending(current)) {
|
|
copied = sock_intr_errno(timeo);
|
|
break;
|
|
}
|
|
}
|
|
|
|
pr_debug("block timeout %ld", timeo);
|
|
sk_wait_data(sk, &timeo, NULL);
|
|
}
|
|
|
|
out_err:
|
|
if (cmsg_flags && copied >= 0) {
|
|
if (cmsg_flags & MPTCP_CMSG_TS)
|
|
tcp_recv_timestamp(msg, sk, &tss);
|
|
|
|
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));
|
|
WRITE_ONCE(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).
|
|
*
|
|
* Outgoing subflows use in-kernel sockets.
|
|
* Incoming subflows do not have their own 'struct socket' allocated,
|
|
* so we need to use tcp_close() after detaching them from the mptcp
|
|
* parent socket.
|
|
*/
|
|
static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
|
|
struct mptcp_subflow_context *subflow,
|
|
unsigned int flags)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
bool dispose_it, need_push = false;
|
|
|
|
/* If the first subflow moved to a close state before accept, e.g. due
|
|
* to an incoming reset, mptcp either:
|
|
* - if either the subflow or the msk are dead, destroy the context
|
|
* (the subflow socket is deleted by inet_child_forget) and the msk
|
|
* - otherwise do nothing at the moment and take action at accept and/or
|
|
* listener shutdown - user-space must be able to accept() the closed
|
|
* socket.
|
|
*/
|
|
if (msk->in_accept_queue && msk->first == ssk) {
|
|
if (!sock_flag(sk, SOCK_DEAD) && !sock_flag(ssk, SOCK_DEAD))
|
|
return;
|
|
|
|
/* ensure later check in mptcp_worker() will dispose the msk */
|
|
sock_set_flag(sk, SOCK_DEAD);
|
|
lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
|
|
mptcp_subflow_drop_ctx(ssk);
|
|
goto out_release;
|
|
}
|
|
|
|
dispose_it = !msk->subflow || ssk != msk->subflow->sk;
|
|
if (dispose_it)
|
|
list_del(&subflow->node);
|
|
|
|
lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
|
|
|
|
if ((flags & MPTCP_CF_FASTCLOSE) && !__mptcp_check_fallback(msk)) {
|
|
/* 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) {
|
|
/* The MPTCP code never wait on the subflow sockets, TCP-level
|
|
* disconnect should never fail
|
|
*/
|
|
WARN_ON_ONCE(tcp_disconnect(ssk, 0));
|
|
msk->subflow->state = SS_UNCONNECTED;
|
|
mptcp_subflow_ctx_reset(subflow);
|
|
release_sock(ssk);
|
|
|
|
goto out;
|
|
}
|
|
|
|
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) {
|
|
WARN_ON_ONCE(!sock_flag(ssk, SOCK_DEAD));
|
|
kfree_rcu(subflow, rcu);
|
|
} else {
|
|
/* otherwise tcp will dispose of the ssk and subflow ctx */
|
|
__tcp_close(ssk, 0);
|
|
|
|
/* close acquired an extra ref */
|
|
__sock_put(ssk);
|
|
}
|
|
|
|
out_release:
|
|
release_sock(ssk);
|
|
|
|
sock_put(ssk);
|
|
|
|
if (ssk == msk->first)
|
|
WRITE_ONCE(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)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void __mptcp_close_subflow(struct sock *sk)
|
|
{
|
|
struct mptcp_subflow_context *subflow, *tmp;
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
|
|
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(sk, ssk, subflow);
|
|
}
|
|
|
|
}
|
|
|
|
static bool mptcp_should_close(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 || mptcp_sk(sk)->in_accept_queue)
|
|
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);
|
|
WRITE_ONCE(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((1 << state) & (TCPF_CLOSE | TCPF_LISTEN)))
|
|
goto unlock;
|
|
|
|
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_ack(sk);
|
|
mptcp_check_data_fin(sk);
|
|
|
|
if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags))
|
|
__mptcp_close_subflow(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_should_close(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_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);
|
|
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;
|
|
|
|
WRITE_ONCE(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)
|
|
{
|
|
struct net *net = sock_net(sk);
|
|
int ret;
|
|
|
|
ret = __mptcp_init_sock(sk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (!mptcp_is_enabled(net))
|
|
return -ENOPROTOOPT;
|
|
|
|
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);
|
|
}
|
|
|
|
void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
|
|
{
|
|
lock_sock(ssk);
|
|
|
|
switch (ssk->sk_state) {
|
|
case TCP_LISTEN:
|
|
if (!(how & RCV_SHUTDOWN))
|
|
break;
|
|
fallthrough;
|
|
case TCP_SYN_SENT:
|
|
WARN_ON_ONCE(tcp_disconnect(ssk, O_NONBLOCK));
|
|
break;
|
|
default:
|
|
if (__mptcp_check_fallback(mptcp_sk(sk))) {
|
|
pr_debug("Fallback");
|
|
ssk->sk_shutdown |= how;
|
|
tcp_shutdown(ssk, how);
|
|
|
|
/* simulate the data_fin ack reception to let the state
|
|
* machine move forward
|
|
*/
|
|
WRITE_ONCE(mptcp_sk(sk)->snd_una, mptcp_sk(sk)->snd_nxt);
|
|
mptcp_schedule_work(sk);
|
|
} else {
|
|
pr_debug("Sending DATA_FIN on subflow %p", ssk);
|
|
tcp_send_ack(ssk);
|
|
if (!mptcp_timer_pending(sk))
|
|
mptcp_reset_timer(sk);
|
|
}
|
|
break;
|
|
}
|
|
|
|
release_sock(ssk);
|
|
}
|
|
|
|
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)
|
|
{
|
|
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);
|
|
|
|
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);
|
|
|
|
/* 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;
|
|
|
|
WRITE_ONCE(msk->snd_nxt, msk->write_seq);
|
|
|
|
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);
|
|
}
|
|
|
|
void __mptcp_unaccepted_force_close(struct sock *sk)
|
|
{
|
|
sock_set_flag(sk, SOCK_DEAD);
|
|
inet_sk_state_store(sk, TCP_CLOSE);
|
|
mptcp_do_fastclose(sk);
|
|
__mptcp_destroy_sock(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;
|
|
}
|
|
|
|
static void mptcp_check_listen_stop(struct sock *sk)
|
|
{
|
|
struct sock *ssk;
|
|
|
|
if (inet_sk_state_load(sk) != TCP_LISTEN)
|
|
return;
|
|
|
|
ssk = mptcp_sk(sk)->first;
|
|
if (WARN_ON_ONCE(!ssk || inet_sk_state_load(ssk) != TCP_LISTEN))
|
|
return;
|
|
|
|
lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
|
|
tcp_set_state(ssk, TCP_CLOSE);
|
|
mptcp_subflow_queue_clean(sk, ssk);
|
|
inet_csk_listen_stop(ssk);
|
|
release_sock(ssk);
|
|
}
|
|
|
|
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;
|
|
int subflows_alive = 0;
|
|
|
|
WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK);
|
|
|
|
if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) {
|
|
mptcp_check_listen_stop(sk);
|
|
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);
|
|
|
|
subflows_alive += ssk->sk_state != TCP_CLOSE;
|
|
|
|
/* since the close timeout takes precedence on the fail one,
|
|
* cancel the latter
|
|
*/
|
|
if (ssk == msk->first)
|
|
subflow->fail_tout = 0;
|
|
|
|
/* detach from the parent socket, but allow data_ready to
|
|
* push incoming data into the mptcp stack, to properly ack it
|
|
*/
|
|
ssk->sk_socket = NULL;
|
|
ssk->sk_wq = NULL;
|
|
unlock_sock_fast(ssk, slow);
|
|
}
|
|
sock_orphan(sk);
|
|
|
|
/* all the subflows are closed, only timeout can change the msk
|
|
* state, let's not keep resources busy for no reasons
|
|
*/
|
|
if (subflows_alive == 0)
|
|
inet_sk_state_store(sk, TCP_CLOSE);
|
|
|
|
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);
|
|
}
|
|
|
|
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)
|
|
{
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
const struct ipv6_pinfo *ssk6 = inet6_sk(ssk);
|
|
struct ipv6_pinfo *msk6 = inet6_sk(msk);
|
|
|
|
msk->sk_v6_daddr = ssk->sk_v6_daddr;
|
|
msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr;
|
|
|
|
if (msk6 && ssk6) {
|
|
msk6->saddr = ssk6->saddr;
|
|
msk6->flow_label = ssk6->flow_label;
|
|
}
|
|
#endif
|
|
|
|
inet_sk(msk)->inet_num = inet_sk(ssk)->inet_num;
|
|
inet_sk(msk)->inet_dport = inet_sk(ssk)->inet_dport;
|
|
inet_sk(msk)->inet_sport = inet_sk(ssk)->inet_sport;
|
|
inet_sk(msk)->inet_daddr = inet_sk(ssk)->inet_daddr;
|
|
inet_sk(msk)->inet_saddr = inet_sk(ssk)->inet_saddr;
|
|
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);
|
|
|
|
/* Deny disconnect if other threads are blocked in sk_wait_event()
|
|
* or inet_wait_for_connect().
|
|
*/
|
|
if (sk->sk_wait_pending)
|
|
return -EBUSY;
|
|
|
|
/* We are on the fastopen error path. We can't call straight into the
|
|
* subflows cleanup code due to lock nesting (we are already under
|
|
* msk->firstsocket lock).
|
|
*/
|
|
if (msk->fastopening)
|
|
return -EBUSY;
|
|
|
|
mptcp_check_listen_stop(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);
|
|
|
|
WRITE_ONCE(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)
|
|
{
|
|
unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo);
|
|
|
|
return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
|
|
}
|
|
#endif
|
|
|
|
struct sock *mptcp_sk_clone_init(const struct sock *sk,
|
|
const struct mptcp_options_received *mp_opt,
|
|
struct sock *ssk,
|
|
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;
|
|
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
|
|
if (nsk->sk_family == AF_INET6)
|
|
inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk);
|
|
#endif
|
|
|
|
nsk->sk_wait_pending = 0;
|
|
__mptcp_init_sock(nsk);
|
|
|
|
msk = mptcp_sk(nsk);
|
|
msk->local_key = subflow_req->local_key;
|
|
msk->token = subflow_req->token;
|
|
WRITE_ONCE(msk->subflow, NULL);
|
|
msk->in_accept_queue = 1;
|
|
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);
|
|
security_inet_csk_clone(nsk, req);
|
|
|
|
/* this can't race with mptcp_close(), as the msk is
|
|
* not yet exposted to user-space
|
|
*/
|
|
inet_sk_state_store(nsk, TCP_ESTABLISHED);
|
|
|
|
/* The msk maintain a ref to each subflow in the connections list */
|
|
WRITE_ONCE(msk->first, ssk);
|
|
list_add(&mptcp_subflow_ctx(ssk)->node, &msk->conn_list);
|
|
sock_hold(ssk);
|
|
|
|
/* new mpc subflow takes ownership of the newly
|
|
* created mptcp socket
|
|
*/
|
|
mptcp_token_accept(subflow_req, msk);
|
|
|
|
/* set msk addresses early to ensure mptcp_pm_get_local_id()
|
|
* uses the correct data
|
|
*/
|
|
mptcp_copy_inaddrs(nsk, ssk);
|
|
mptcp_propagate_sndbuf(nsk, ssk);
|
|
|
|
mptcp_rcv_space_init(msk, ssk);
|
|
bh_unlock_sock(nsk);
|
|
|
|
/* note: the newly allocated socket refcount is 2 now */
|
|
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)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
struct socket *listener;
|
|
struct sock *newsk;
|
|
|
|
listener = READ_ONCE(msk->subflow);
|
|
if (WARN_ON_ONCE(!listener)) {
|
|
*err = -EINVAL;
|
|
return NULL;
|
|
}
|
|
|
|
pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk));
|
|
newsk = inet_csk_accept(listener->sk, flags, err, kern);
|
|
if (!newsk)
|
|
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;
|
|
|
|
subflow = mptcp_subflow_ctx(newsk);
|
|
new_mptcp_sock = subflow->conn;
|
|
|
|
/* 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;
|
|
}
|
|
|
|
newsk = new_mptcp_sock;
|
|
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK);
|
|
} else {
|
|
MPTCP_INC_STATS(sock_net(sk),
|
|
MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
|
|
}
|
|
|
|
out:
|
|
newsk->sk_kern_sock = kern;
|
|
return newsk;
|
|
}
|
|
|
|
void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags)
|
|
{
|
|
struct mptcp_subflow_context *subflow, *tmp;
|
|
struct sock *sk = (struct sock *)msk;
|
|
|
|
__mptcp_clear_xmit(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);
|
|
|
|
/* 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);
|
|
|
|
/* move all the rx fwd alloc into the sk_mem_reclaim_final in
|
|
* inet_sock_destruct() will dispose it
|
|
*/
|
|
sk_forward_alloc_add(sk, msk->rmem_fwd_alloc);
|
|
WRITE_ONCE(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);
|
|
|
|
/* 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);
|
|
}
|
|
|
|
void __mptcp_data_acked(struct sock *sk)
|
|
{
|
|
if (!sock_owned_by_user(sk))
|
|
__mptcp_clean_una(sk);
|
|
else
|
|
__set_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->cb_flags);
|
|
|
|
if (mptcp_pending_data_fin_ack(sk))
|
|
mptcp_schedule_work(sk);
|
|
}
|
|
|
|
void __mptcp_check_push(struct sock *sk, struct sock *ssk)
|
|
{
|
|
if (!mptcp_send_head(sk))
|
|
return;
|
|
|
|
if (!sock_owned_by_user(sk)) {
|
|
struct sock *xmit_ssk = mptcp_subflow_get_send(mptcp_sk(sk));
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
#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);
|
|
|
|
for (;;) {
|
|
unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED) |
|
|
msk->push_pending;
|
|
struct list_head join_list;
|
|
|
|
if (!flags)
|
|
break;
|
|
|
|
INIT_LIST_HEAD(&join_list);
|
|
list_splice_init(&msk->join_list, &join_list);
|
|
|
|
/* 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, &join_list);
|
|
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);
|
|
}
|
|
|
|
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;
|
|
|
|
/* 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)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sk);
|
|
struct socket *ssock;
|
|
|
|
ssock = msk->subflow;
|
|
pr_debug("msk=%p, subflow=%p", msk, ssock);
|
|
if (WARN_ON_ONCE(!ssock))
|
|
return -EINVAL;
|
|
|
|
return inet_csk_get_port(ssock->sk, snum);
|
|
}
|
|
|
|
void mptcp_finish_connect(struct sock *ssk)
|
|
{
|
|
struct mptcp_subflow_context *subflow;
|
|
struct mptcp_sock *msk;
|
|
struct sock *sk;
|
|
u64 ack_seq;
|
|
|
|
subflow = mptcp_subflow_ctx(ssk);
|
|
sk = subflow->conn;
|
|
msk = mptcp_sk(sk);
|
|
|
|
pr_debug("msk=%p, token=%u", sk, subflow->token);
|
|
|
|
mptcp_crypto_key_sha(subflow->remote_key, NULL, &ack_seq);
|
|
ack_seq++;
|
|
subflow->map_seq = ack_seq;
|
|
subflow->map_subflow_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->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);
|
|
}
|
|
|
|
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);
|
|
sk_set_socket(sk, parent);
|
|
sk->sk_uid = SOCK_INODE(parent)->i_uid;
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/* active subflow, already present inside the conn_list */
|
|
if (!list_empty(&subflow->node)) {
|
|
mptcp_subflow_joined(msk, ssk);
|
|
return true;
|
|
}
|
|
|
|
if (!mptcp_pm_allow_new_subflow(msk))
|
|
goto err_prohibited;
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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 READ_ONCE(sk->sk_forward_alloc) +
|
|
READ_ONCE(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;
|
|
|
|
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->fastopening)
|
|
err = __inet_stream_connect(ssock, uaddr, addr_len, O_NONBLOCK, 1);
|
|
else
|
|
err = inet_stream_connect(ssock, uaddr, addr_len, O_NONBLOCK);
|
|
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);
|
|
|
|
/* silence EINPROGRESS and let the caller inet_stream_connect
|
|
* handle the connection in progress
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
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 = mptcp_shutdown,
|
|
.destroy = mptcp_destroy,
|
|
.sendmsg = mptcp_sendmsg,
|
|
.ioctl = mptcp_ioctl,
|
|
.recvmsg = mptcp_recvmsg,
|
|
.release_cb = mptcp_release_cb,
|
|
.hash = mptcp_hash,
|
|
.unhash = mptcp_unhash,
|
|
.get_port = mptcp_get_port,
|
|
.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,
|
|
};
|
|
|
|
static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sock->sk);
|
|
struct socket *ssock;
|
|
int err;
|
|
|
|
lock_sock(sock->sk);
|
|
ssock = __mptcp_nmpc_socket(msk);
|
|
if (!ssock) {
|
|
err = -EINVAL;
|
|
goto unlock;
|
|
}
|
|
|
|
err = ssock->ops->bind(ssock, uaddr, addr_len);
|
|
if (!err)
|
|
mptcp_copy_inaddrs(sock->sk, ssock->sk);
|
|
|
|
unlock:
|
|
release_sock(sock->sk);
|
|
return err;
|
|
}
|
|
|
|
static int mptcp_listen(struct socket *sock, int backlog)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sock->sk);
|
|
struct sock *sk = sock->sk;
|
|
struct socket *ssock;
|
|
int err;
|
|
|
|
pr_debug("msk=%p", msk);
|
|
|
|
lock_sock(sk);
|
|
|
|
err = -EINVAL;
|
|
if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
|
|
goto unlock;
|
|
|
|
ssock = __mptcp_nmpc_socket(msk);
|
|
if (!ssock) {
|
|
err = -EINVAL;
|
|
goto unlock;
|
|
}
|
|
|
|
mptcp_token_destroy(msk);
|
|
inet_sk_state_store(sk, TCP_LISTEN);
|
|
sock_set_flag(sk, SOCK_RCU_FREE);
|
|
|
|
err = ssock->ops->listen(ssock, backlog);
|
|
inet_sk_state_store(sk, inet_sk_state_load(ssock->sk));
|
|
if (!err)
|
|
mptcp_copy_inaddrs(sk, ssock->sk);
|
|
|
|
unlock:
|
|
release_sock(sk);
|
|
return err;
|
|
}
|
|
|
|
static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
|
|
int flags, bool kern)
|
|
{
|
|
struct mptcp_sock *msk = mptcp_sk(sock->sk);
|
|
struct socket *ssock;
|
|
int err;
|
|
|
|
pr_debug("msk=%p", msk);
|
|
|
|
/* Buggy applications can call accept on socket states other then LISTEN
|
|
* but no need to allocate the first subflow just to error out.
|
|
*/
|
|
ssock = READ_ONCE(msk->subflow);
|
|
if (!ssock)
|
|
return -EINVAL;
|
|
|
|
err = ssock->ops->accept(sock, newsock, flags, kern);
|
|
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;
|
|
|
|
msk->in_accept_queue = 0;
|
|
|
|
lock_sock(newsk);
|
|
|
|
/* set ssk->sk_socket of accept()ed flows to mptcp socket.
|
|
* This is needed so NOSPACE flag can be set from tcp stack.
|
|
*/
|
|
mptcp_for_each_subflow(msk, subflow) {
|
|
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
|
|
|
|
if (!ssk->sk_socket)
|
|
mptcp_sock_graft(ssk, newsock);
|
|
}
|
|
|
|
/* Do late cleanup for the first subflow as necessary. Also
|
|
* deal with bad peers not doing a complete shutdown.
|
|
*/
|
|
if (msk->first &&
|
|
unlikely(inet_sk_state_load(msk->first) == TCP_CLOSE)) {
|
|
__mptcp_close_ssk(newsk, msk->first,
|
|
mptcp_subflow_ctx(msk->first), 0);
|
|
if (unlikely(list_empty(&msk->conn_list)))
|
|
inet_sk_state_store(newsk, TCP_CLOSE);
|
|
}
|
|
|
|
release_sock(newsk);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static __poll_t mptcp_check_writeable(struct mptcp_sock *msk)
|
|
{
|
|
struct sock *sk = (struct sock *)msk;
|
|
|
|
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,
|
|
struct poll_table_struct *wait)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct mptcp_sock *msk;
|
|
__poll_t mask = 0;
|
|
u8 shutdown;
|
|
int state;
|
|
|
|
msk = mptcp_sk(sk);
|
|
sock_poll_wait(file, sock, wait);
|
|
|
|
state = inet_sk_state_load(sk);
|
|
pr_debug("msk=%p state=%d flags=%lx", msk, state, msk->flags);
|
|
if (state == TCP_LISTEN) {
|
|
struct socket *ssock = READ_ONCE(msk->subflow);
|
|
|
|
if (WARN_ON_ONCE(!ssock || !ssock->sk))
|
|
return 0;
|
|
|
|
return inet_csk_listen_poll(ssock->sk);
|
|
}
|
|
|
|
shutdown = READ_ONCE(sk->sk_shutdown);
|
|
if (shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
|
|
mask |= EPOLLHUP;
|
|
if (shutdown & RCV_SHUTDOWN)
|
|
mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
|
|
|
|
if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) {
|
|
mask |= mptcp_check_readable(msk);
|
|
if (shutdown & SEND_SHUTDOWN)
|
|
mask |= EPOLLOUT | EPOLLWRNORM;
|
|
else
|
|
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;
|
|
}
|
|
|
|
/* This barrier is coupled with smp_wmb() in __mptcp_error_report() */
|
|
smp_rmb();
|
|
if (sk->sk_err)
|
|
mask |= EPOLLERR;
|
|
|
|
return mask;
|
|
}
|
|
|
|
static const struct proto_ops mptcp_stream_ops = {
|
|
.family = PF_INET,
|
|
.owner = THIS_MODULE,
|
|
.release = inet_release,
|
|
.bind = mptcp_bind,
|
|
.connect = inet_stream_connect,
|
|
.socketpair = sock_no_socketpair,
|
|
.accept = mptcp_stream_accept,
|
|
.getname = inet_getname,
|
|
.poll = mptcp_poll,
|
|
.ioctl = inet_ioctl,
|
|
.gettstamp = sock_gettstamp,
|
|
.listen = mptcp_listen,
|
|
.shutdown = inet_shutdown,
|
|
.setsockopt = sock_common_setsockopt,
|
|
.getsockopt = sock_common_getsockopt,
|
|
.sendmsg = inet_sendmsg,
|
|
.recvmsg = inet_recvmsg,
|
|
.mmap = sock_no_mmap,
|
|
.sendpage = inet_sendpage,
|
|
};
|
|
|
|
static struct inet_protosw mptcp_protosw = {
|
|
.type = SOCK_STREAM,
|
|
.protocol = IPPROTO_MPTCP,
|
|
.prot = &mptcp_prot,
|
|
.ops = &mptcp_stream_ops,
|
|
.flags = INET_PROTOSW_ICSK,
|
|
};
|
|
|
|
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)
|
|
static const struct proto_ops mptcp_v6_stream_ops = {
|
|
.family = PF_INET6,
|
|
.owner = THIS_MODULE,
|
|
.release = inet6_release,
|
|
.bind = mptcp_bind,
|
|
.connect = inet_stream_connect,
|
|
.socketpair = sock_no_socketpair,
|
|
.accept = mptcp_stream_accept,
|
|
.getname = inet6_getname,
|
|
.poll = mptcp_poll,
|
|
.ioctl = inet6_ioctl,
|
|
.gettstamp = sock_gettstamp,
|
|
.listen = mptcp_listen,
|
|
.shutdown = inet_shutdown,
|
|
.setsockopt = sock_common_setsockopt,
|
|
.getsockopt = sock_common_getsockopt,
|
|
.sendmsg = inet6_sendmsg,
|
|
.recvmsg = inet6_recvmsg,
|
|
.mmap = sock_no_mmap,
|
|
.sendpage = inet_sendpage,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = inet6_compat_ioctl,
|
|
#endif
|
|
};
|
|
|
|
static struct proto mptcp_v6_prot;
|
|
|
|
static struct inet_protosw mptcp_v6_protosw = {
|
|
.type = SOCK_STREAM,
|
|
.protocol = IPPROTO_MPTCP,
|
|
.prot = &mptcp_v6_prot,
|
|
.ops = &mptcp_v6_stream_ops,
|
|
.flags = INET_PROTOSW_ICSK,
|
|
};
|
|
|
|
int __init mptcp_proto_v6_init(void)
|
|
{
|
|
int err;
|
|
|
|
mptcp_v6_prot = mptcp_prot;
|
|
strcpy(mptcp_v6_prot.name, "MPTCPv6");
|
|
mptcp_v6_prot.slab = NULL;
|
|
mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock);
|
|
|
|
err = proto_register(&mptcp_v6_prot, 1);
|
|
if (err)
|
|
return err;
|
|
|
|
err = inet6_register_protosw(&mptcp_v6_protosw);
|
|
if (err)
|
|
proto_unregister(&mptcp_v6_prot);
|
|
|
|
return err;
|
|
}
|
|
#endif
|