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3642 lines
89 KiB
3642 lines
89 KiB
// 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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|
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#define pr_fmt(fmt) "MPTCP: " fmt |
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|
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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 "protocol.h" |
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#include "mib.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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}; |
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#define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0])) |
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static struct percpu_counter mptcp_sockets_allocated; |
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|
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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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|
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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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|
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return msk->subflow; |
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} |
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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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|
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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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|
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return false; |
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} |
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static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk) |
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{ |
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sock_owned_by_me((const struct sock *)msk); |
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|
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if (likely(!__mptcp_check_fallback(msk))) |
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return NULL; |
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|
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return msk->first; |
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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, &ssock); |
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if (err) |
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return err; |
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msk->first = ssock->sk; |
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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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mptcp_sock_graft(msk->first, sk->sk_socket); |
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|
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return 0; |
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} |
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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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|
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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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kfree_skb_partial(from, fragstolen); |
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atomic_add(delta, &sk->sk_rmem_alloc); |
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sk_mem_charge(sk, delta); |
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return true; |
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} |
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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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|
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return mptcp_try_coalesce((struct sock *)msk, to, from); |
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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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|
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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 = READ_ONCE(msk->rcv_wnd_sent); |
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|
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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)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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|
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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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|
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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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|
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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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skb_set_owner_r(skb, sk); |
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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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__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 (!sk_rmem_schedule(sk, skb, skb->truesize)) { |
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if (ssk->sk_forward_alloc < skb->truesize) |
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goto drop; |
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__sk_mem_reclaim(ssk, skb->truesize); |
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if (!sk_rmem_schedule(sk, skb, skb->truesize)) |
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goto drop; |
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} |
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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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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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skb_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 !__mptcp_check_fallback(msk) && |
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((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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|
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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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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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|
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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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|
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return true; |
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} |
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} |
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|
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return false; |
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} |
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static void mptcp_set_datafin_timeout(const struct sock *sk) |
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{ |
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struct inet_connection_sock *icsk = inet_csk(sk); |
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|
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mptcp_sk(sk)->timer_ival = min(TCP_RTO_MAX, |
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TCP_RTO_MIN << icsk->icsk_retransmits); |
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} |
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|
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static void mptcp_set_timeout(const struct sock *sk, const struct sock *ssk) |
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{ |
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long tout = ssk && inet_csk(ssk)->icsk_pending ? |
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inet_csk(ssk)->icsk_timeout - jiffies : 0; |
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|
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if (tout <= 0) |
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tout = mptcp_sk(sk)->timer_ival; |
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mptcp_sk(sk)->timer_ival = tout > 0 ? tout : TCP_RTO_MIN; |
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} |
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|
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static bool mptcp_subflow_active(struct mptcp_subflow_context *subflow) |
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{ |
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struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
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|
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/* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */ |
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if (subflow->request_join && !subflow->fully_established) |
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return false; |
|
|
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/* only send if our side has not closed yet */ |
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return ((1 << ssk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)); |
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} |
|
|
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static bool tcp_can_send_ack(const struct sock *ssk) |
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{ |
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return !((1 << inet_sk_state_load(ssk)) & |
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(TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN)); |
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} |
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|
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static void mptcp_send_ack(struct mptcp_sock *msk) |
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{ |
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struct mptcp_subflow_context *subflow; |
|
|
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mptcp_for_each_subflow(msk, subflow) { |
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struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
|
|
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lock_sock(ssk); |
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if (tcp_can_send_ack(ssk)) |
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tcp_send_ack(ssk); |
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release_sock(ssk); |
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} |
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} |
|
|
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static bool mptcp_subflow_cleanup_rbuf(struct sock *ssk) |
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{ |
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int ret; |
|
|
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lock_sock(ssk); |
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ret = tcp_can_send_ack(ssk); |
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if (ret) |
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tcp_cleanup_rbuf(ssk, 1); |
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release_sock(ssk); |
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return ret; |
|
} |
|
|
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static void mptcp_cleanup_rbuf(struct mptcp_sock *msk) |
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{ |
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struct sock *ack_hint = READ_ONCE(msk->ack_hint); |
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int old_space = READ_ONCE(msk->old_wspace); |
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struct mptcp_subflow_context *subflow; |
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struct sock *sk = (struct sock *)msk; |
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bool cleanup; |
|
|
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/* this is a simple superset of what tcp_cleanup_rbuf() implements |
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* so that we don't have to acquire the ssk socket lock most of the time |
|
* to do actually nothing |
|
*/ |
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cleanup = __mptcp_space(sk) - old_space >= max(0, old_space); |
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if (!cleanup) |
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return; |
|
|
|
/* if the hinted ssk is still active, try to use it */ |
|
if (likely(ack_hint)) { |
|
mptcp_for_each_subflow(msk, subflow) { |
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struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
|
|
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if (ack_hint == ssk && mptcp_subflow_cleanup_rbuf(ssk)) |
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return; |
|
} |
|
} |
|
|
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/* otherwise pick the first active subflow */ |
|
mptcp_for_each_subflow(msk, subflow) |
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if (mptcp_subflow_cleanup_rbuf(mptcp_subflow_tcp_sock(subflow))) |
|
return; |
|
} |
|
|
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static bool mptcp_check_data_fin(struct sock *sk) |
|
{ |
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struct mptcp_sock *msk = mptcp_sk(sk); |
|
u64 rcv_data_fin_seq; |
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bool ret = false; |
|
|
|
if (__mptcp_check_fallback(msk) || !msk->first) |
|
return ret; |
|
|
|
/* Need to ack a DATA_FIN received from a peer while this side |
|
* of the connection is in ESTABLISHED, FIN_WAIT1, or FIN_WAIT2. |
|
* msk->rcv_data_fin was set when parsing the incoming options |
|
* at the subflow level and the msk lock was not held, so this |
|
* is the first opportunity to act on the DATA_FIN and change |
|
* the msk state. |
|
* |
|
* If we are caught up to the sequence number of the incoming |
|
* DATA_FIN, send the DATA_ACK now and do state transition. If |
|
* not caught up, do nothing and let the recv code send DATA_ACK |
|
* when catching up. |
|
*/ |
|
|
|
if (mptcp_pending_data_fin(sk, &rcv_data_fin_seq)) { |
|
WRITE_ONCE(msk->ack_seq, msk->ack_seq + 1); |
|
WRITE_ONCE(msk->rcv_data_fin, 0); |
|
|
|
sk->sk_shutdown |= RCV_SHUTDOWN; |
|
smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ |
|
set_bit(MPTCP_DATA_READY, &msk->flags); |
|
|
|
switch (sk->sk_state) { |
|
case TCP_ESTABLISHED: |
|
inet_sk_state_store(sk, TCP_CLOSE_WAIT); |
|
break; |
|
case TCP_FIN_WAIT1: |
|
inet_sk_state_store(sk, TCP_CLOSING); |
|
break; |
|
case TCP_FIN_WAIT2: |
|
inet_sk_state_store(sk, TCP_CLOSE); |
|
break; |
|
default: |
|
/* Other states not expected */ |
|
WARN_ON_ONCE(1); |
|
break; |
|
} |
|
|
|
ret = true; |
|
mptcp_set_timeout(sk, NULL); |
|
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) { |
|
/* if no data is found, a racing workqueue/recvmsg |
|
* already processed the new data, stop here or we |
|
* can enter an infinite loop |
|
*/ |
|
if (!moved) |
|
done = true; |
|
break; |
|
} |
|
|
|
if (__mptcp_check_fallback(msk)) { |
|
/* if we are running under the workqueue, TCP could have |
|
* collapsed skbs between dummy map creation and now |
|
* be sure to adjust the 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); |
|
WRITE_ONCE(msk->ack_hint, ssk); |
|
|
|
*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; |
|
__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 void move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) |
|
{ |
|
struct sock *sk = (struct sock *)msk; |
|
unsigned int moved = 0; |
|
|
|
if (inet_sk_state_load(sk) == TCP_CLOSE) |
|
return; |
|
|
|
mptcp_data_lock(sk); |
|
|
|
__mptcp_move_skbs_from_subflow(msk, ssk, &moved); |
|
__mptcp_ofo_queue(msk); |
|
|
|
/* 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); |
|
mptcp_data_unlock(sk); |
|
} |
|
|
|
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; |
|
bool wake; |
|
|
|
/* 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; |
|
|
|
/* move_skbs_to_msk below can legitly clear the data_avail flag, |
|
* but we will need later to properly woke the reader, cache its |
|
* value |
|
*/ |
|
wake = subflow->data_avail == MPTCP_SUBFLOW_DATA_AVAIL; |
|
if (wake) |
|
set_bit(MPTCP_DATA_READY, &msk->flags); |
|
|
|
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 */ |
|
if (atomic_read(&sk->sk_rmem_alloc) > sk_rbuf) |
|
goto wake; |
|
|
|
move_skbs_to_msk(msk, ssk); |
|
|
|
wake: |
|
if (wake) |
|
sk->sk_data_ready(sk); |
|
} |
|
|
|
void __mptcp_flush_join_list(struct mptcp_sock *msk) |
|
{ |
|
struct mptcp_subflow_context *subflow; |
|
|
|
if (likely(list_empty(&msk->join_list))) |
|
return; |
|
|
|
spin_lock_bh(&msk->join_list_lock); |
|
list_for_each_entry(subflow, &msk->join_list, node) |
|
mptcp_propagate_sndbuf((struct sock *)msk, mptcp_subflow_tcp_sock(subflow)); |
|
list_splice_tail_init(&msk->join_list, &msk->conn_list); |
|
spin_unlock_bh(&msk->join_list_lock); |
|
} |
|
|
|
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; |
|
|
|
/* should never be called with mptcp level timer cleared */ |
|
tout = READ_ONCE(mptcp_sk(sk)->timer_ival); |
|
if (WARN_ON_ONCE(!tout)) |
|
tout = TCP_RTO_MIN; |
|
sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + tout); |
|
} |
|
|
|
bool mptcp_schedule_work(struct sock *sk) |
|
{ |
|
if (inet_sk_state_load(sk) != TCP_CLOSE && |
|
schedule_work(&mptcp_sk(sk)->work)) { |
|
/* each subflow already holds a reference to the sk, and the |
|
* workqueue is invoked by a subflow, so sk can't go away here. |
|
*/ |
|
sock_hold(sk); |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
void mptcp_subflow_eof(struct sock *sk) |
|
{ |
|
if (!test_and_set_bit(MPTCP_WORK_EOF, &mptcp_sk(sk)->flags)) |
|
mptcp_schedule_work(sk); |
|
} |
|
|
|
static void mptcp_check_for_eof(struct mptcp_sock *msk) |
|
{ |
|
struct mptcp_subflow_context *subflow; |
|
struct sock *sk = (struct sock *)msk; |
|
int receivers = 0; |
|
|
|
mptcp_for_each_subflow(msk, subflow) |
|
receivers += !subflow->rx_eof; |
|
if (receivers) |
|
return; |
|
|
|
if (!(sk->sk_shutdown & RCV_SHUTDOWN)) { |
|
/* hopefully temporary hack: propagate shutdown status |
|
* to msk, when all subflows agree on it |
|
*/ |
|
sk->sk_shutdown |= RCV_SHUTDOWN; |
|
|
|
smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ |
|
set_bit(MPTCP_DATA_READY, &msk->flags); |
|
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 (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; |
|
} |
|
|
|
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 && |
|
df->data_seq + df->data_len == msk->write_seq; |
|
} |
|
|
|
static int mptcp_wmem_with_overhead(struct sock *sk, int size) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
int ret, skbs; |
|
|
|
ret = size + ((sizeof(struct mptcp_data_frag) * size) >> PAGE_SHIFT); |
|
skbs = (msk->tx_pending_data + size) / msk->size_goal_cache; |
|
if (skbs < msk->skb_tx_cache.qlen) |
|
return ret; |
|
|
|
return ret + (skbs - msk->skb_tx_cache.qlen) * SKB_TRUESIZE(MAX_TCP_HEADER); |
|
} |
|
|
|
static void __mptcp_wmem_reserve(struct sock *sk, int size) |
|
{ |
|
int amount = mptcp_wmem_with_overhead(sk, size); |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
WARN_ON_ONCE(msk->wmem_reserved); |
|
if (WARN_ON_ONCE(amount < 0)) |
|
amount = 0; |
|
|
|
if (amount <= sk->sk_forward_alloc) |
|
goto reserve; |
|
|
|
/* under memory pressure try to reserve at most a single page |
|
* otherwise try to reserve the full estimate and fallback |
|
* to a single page before entering the error path |
|
*/ |
|
if ((tcp_under_memory_pressure(sk) && amount > PAGE_SIZE) || |
|
!sk_wmem_schedule(sk, amount)) { |
|
if (amount <= PAGE_SIZE) |
|
goto nomem; |
|
|
|
amount = PAGE_SIZE; |
|
if (!sk_wmem_schedule(sk, amount)) |
|
goto nomem; |
|
} |
|
|
|
reserve: |
|
msk->wmem_reserved = amount; |
|
sk->sk_forward_alloc -= amount; |
|
return; |
|
|
|
nomem: |
|
/* we will wait for memory on next allocation */ |
|
msk->wmem_reserved = -1; |
|
} |
|
|
|
static void __mptcp_update_wmem(struct sock *sk) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
if (!msk->wmem_reserved) |
|
return; |
|
|
|
if (msk->wmem_reserved < 0) |
|
msk->wmem_reserved = 0; |
|
if (msk->wmem_reserved > 0) { |
|
sk->sk_forward_alloc += msk->wmem_reserved; |
|
msk->wmem_reserved = 0; |
|
} |
|
} |
|
|
|
static bool mptcp_wmem_alloc(struct sock *sk, int size) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
/* check for pre-existing error condition */ |
|
if (msk->wmem_reserved < 0) |
|
return false; |
|
|
|
if (msk->wmem_reserved >= size) |
|
goto account; |
|
|
|
mptcp_data_lock(sk); |
|
if (!sk_wmem_schedule(sk, size)) { |
|
mptcp_data_unlock(sk); |
|
return false; |
|
} |
|
|
|
sk->sk_forward_alloc -= size; |
|
msk->wmem_reserved += size; |
|
mptcp_data_unlock(sk); |
|
|
|
account: |
|
msk->wmem_reserved -= size; |
|
return true; |
|
} |
|
|
|
static void mptcp_wmem_uncharge(struct sock *sk, int size) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
if (msk->wmem_reserved < 0) |
|
msk->wmem_reserved = 0; |
|
msk->wmem_reserved += size; |
|
} |
|
|
|
static void mptcp_mem_reclaim_partial(struct sock *sk) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
/* if we are experiencing a transint allocation error, |
|
* the forward allocation memory has been already |
|
* released |
|
*/ |
|
if (msk->wmem_reserved < 0) |
|
return; |
|
|
|
mptcp_data_lock(sk); |
|
sk->sk_forward_alloc += msk->wmem_reserved; |
|
sk_mem_reclaim_partial(sk); |
|
msk->wmem_reserved = sk->sk_forward_alloc; |
|
sk->sk_forward_alloc = 0; |
|
mptcp_data_unlock(sk); |
|
} |
|
|
|
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; |
|
bool cleaned = false; |
|
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 (WARN_ON_ONCE(dfrag == msk->first_pending)) |
|
break; |
|
dfrag_clear(sk, dfrag); |
|
cleaned = true; |
|
} |
|
|
|
dfrag = mptcp_rtx_head(sk); |
|
if (dfrag && after64(snd_una, dfrag->data_seq)) { |
|
u64 delta = snd_una - dfrag->data_seq; |
|
|
|
if (WARN_ON_ONCE(delta > dfrag->already_sent)) |
|
goto out; |
|
|
|
dfrag->data_seq += delta; |
|
dfrag->offset += delta; |
|
dfrag->data_len -= delta; |
|
dfrag->already_sent -= delta; |
|
|
|
dfrag_uncharge(sk, delta); |
|
cleaned = true; |
|
} |
|
|
|
out: |
|
if (cleaned) { |
|
if (tcp_under_memory_pressure(sk)) { |
|
__mptcp_update_wmem(sk); |
|
sk_mem_reclaim_partial(sk); |
|
} |
|
} |
|
|
|
if (snd_una == READ_ONCE(msk->snd_nxt)) { |
|
if (msk->timer_ival && !mptcp_data_fin_enabled(msk)) |
|
mptcp_stop_timer(sk); |
|
} else { |
|
mptcp_reset_timer(sk); |
|
} |
|
} |
|
|
|
static void __mptcp_clean_una_wakeup(struct sock *sk) |
|
{ |
|
__mptcp_clean_una(sk); |
|
mptcp_write_space(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; |
|
}; |
|
|
|
static int mptcp_check_allowed_size(struct mptcp_sock *msk, u64 data_seq, |
|
int avail_size) |
|
{ |
|
u64 window_end = mptcp_wnd_end(msk); |
|
|
|
if (__mptcp_check_fallback(msk)) |
|
return avail_size; |
|
|
|
if (!before64(data_seq + avail_size, window_end)) { |
|
u64 allowed_size = window_end - data_seq; |
|
|
|
return min_t(unsigned int, allowed_size, avail_size); |
|
} |
|
|
|
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->reserved_tailroom = skb->end - skb->tail; |
|
return skb; |
|
} |
|
__kfree_skb(skb); |
|
} else { |
|
mptcp_enter_memory_pressure(sk); |
|
} |
|
return NULL; |
|
} |
|
|
|
static bool mptcp_tx_cache_refill(struct sock *sk, int size, |
|
struct sk_buff_head *skbs, int *total_ts) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
struct sk_buff *skb; |
|
int space_needed; |
|
|
|
if (unlikely(tcp_under_memory_pressure(sk))) { |
|
mptcp_mem_reclaim_partial(sk); |
|
|
|
/* under pressure pre-allocate at most a single skb */ |
|
if (msk->skb_tx_cache.qlen) |
|
return true; |
|
space_needed = msk->size_goal_cache; |
|
} else { |
|
space_needed = msk->tx_pending_data + size - |
|
msk->skb_tx_cache.qlen * msk->size_goal_cache; |
|
} |
|
|
|
while (space_needed > 0) { |
|
skb = __mptcp_do_alloc_tx_skb(sk, sk->sk_allocation); |
|
if (unlikely(!skb)) { |
|
/* under memory pressure, try to pass the caller a |
|
* single skb to allow forward progress |
|
*/ |
|
while (skbs->qlen > 1) { |
|
skb = __skb_dequeue_tail(skbs); |
|
*total_ts -= skb->truesize; |
|
__kfree_skb(skb); |
|
} |
|
return skbs->qlen > 0; |
|
} |
|
|
|
*total_ts += skb->truesize; |
|
__skb_queue_tail(skbs, skb); |
|
space_needed -= msk->size_goal_cache; |
|
} |
|
return true; |
|
} |
|
|
|
static bool __mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
struct sk_buff *skb; |
|
|
|
if (ssk->sk_tx_skb_cache) { |
|
skb = ssk->sk_tx_skb_cache; |
|
if (unlikely(!skb_ext_find(skb, SKB_EXT_MPTCP) && |
|
!__mptcp_add_ext(skb, gfp))) |
|
return false; |
|
return true; |
|
} |
|
|
|
skb = skb_peek(&msk->skb_tx_cache); |
|
if (skb) { |
|
if (likely(sk_wmem_schedule(ssk, skb->truesize))) { |
|
skb = __skb_dequeue(&msk->skb_tx_cache); |
|
if (WARN_ON_ONCE(!skb)) |
|
return false; |
|
|
|
mptcp_wmem_uncharge(sk, skb->truesize); |
|
ssk->sk_tx_skb_cache = skb; |
|
return true; |
|
} |
|
|
|
/* over memory limit, no point to try to allocate a new skb */ |
|
return false; |
|
} |
|
|
|
skb = __mptcp_do_alloc_tx_skb(sk, gfp); |
|
if (!skb) |
|
return false; |
|
|
|
if (likely(sk_wmem_schedule(ssk, skb->truesize))) { |
|
ssk->sk_tx_skb_cache = skb; |
|
return true; |
|
} |
|
kfree_skb(skb); |
|
return false; |
|
} |
|
|
|
static bool mptcp_must_reclaim_memory(struct sock *sk, struct sock *ssk) |
|
{ |
|
return !ssk->sk_tx_skb_cache && |
|
!skb_peek(&mptcp_sk(sk)->skb_tx_cache) && |
|
tcp_under_memory_pressure(sk); |
|
} |
|
|
|
static bool mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk) |
|
{ |
|
if (unlikely(mptcp_must_reclaim_memory(sk, ssk))) |
|
mptcp_mem_reclaim_partial(sk); |
|
return __mptcp_alloc_tx_skb(sk, ssk, sk->sk_allocation); |
|
} |
|
|
|
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; |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
bool zero_window_probe = false; |
|
struct mptcp_ext *mpext = NULL; |
|
struct sk_buff *skb, *tail; |
|
bool can_collapse = false; |
|
int size_bias = 0; |
|
int avail_size; |
|
size_t ret = 0; |
|
|
|
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); |
|
|
|
/* compute send limit */ |
|
info->mss_now = tcp_send_mss(ssk, &info->size_goal, info->flags); |
|
avail_size = info->size_goal; |
|
msk->size_goal_cache = info->size_goal; |
|
skb = tcp_write_queue_tail(ssk); |
|
if (skb) { |
|
/* 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); |
|
can_collapse = (info->size_goal - skb->len > 0) && |
|
mptcp_skb_can_collapse_to(data_seq, skb, mpext); |
|
if (!can_collapse) { |
|
TCP_SKB_CB(skb)->eor = 1; |
|
} else { |
|
size_bias = skb->len; |
|
avail_size = info->size_goal - skb->len; |
|
} |
|
} |
|
|
|
/* Zero window and all data acked? Probe. */ |
|
avail_size = mptcp_check_allowed_size(msk, data_seq, avail_size); |
|
if (avail_size == 0) { |
|
u64 snd_una = READ_ONCE(msk->snd_una); |
|
|
|
if (skb || snd_una != msk->snd_nxt) |
|
return 0; |
|
zero_window_probe = true; |
|
data_seq = snd_una - 1; |
|
avail_size = 1; |
|
} |
|
|
|
if (WARN_ON_ONCE(info->sent > info->limit || |
|
info->limit > dfrag->data_len)) |
|
return 0; |
|
|
|
ret = info->limit - info->sent; |
|
tail = tcp_build_frag(ssk, avail_size + size_bias, info->flags, |
|
dfrag->page, dfrag->offset + info->sent, &ret); |
|
if (!tail) { |
|
tcp_remove_empty_skb(sk, tcp_write_queue_tail(ssk)); |
|
return -ENOMEM; |
|
} |
|
|
|
/* if the tail skb is still the cached one, collapsing really happened. |
|
*/ |
|
if (skb == tail) { |
|
TCP_SKB_CB(tail)->tcp_flags &= ~TCPHDR_PSH; |
|
mpext->data_len += ret; |
|
WARN_ON_ONCE(!can_collapse); |
|
WARN_ON_ONCE(zero_window_probe); |
|
goto out; |
|
} |
|
|
|
mpext = skb_ext_find(tail, SKB_EXT_MPTCP); |
|
if (WARN_ON_ONCE(!mpext)) { |
|
/* should never reach here, stream corrupted */ |
|
return -EINVAL; |
|
} |
|
|
|
memset(mpext, 0, sizeof(*mpext)); |
|
mpext->data_seq = data_seq; |
|
mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq; |
|
mpext->data_len = ret; |
|
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 += ret; |
|
mpext->frozen = 1; |
|
ret = 0; |
|
tcp_push_pending_frames(ssk); |
|
} |
|
out: |
|
mptcp_subflow_ctx(ssk)->rel_write_seq += ret; |
|
return ret; |
|
} |
|
|
|
#define MPTCP_SEND_BURST_SIZE ((1 << 16) - \ |
|
sizeof(struct tcphdr) - \ |
|
MAX_TCP_OPTION_SPACE - \ |
|
sizeof(struct ipv6hdr) - \ |
|
sizeof(struct frag_hdr)) |
|
|
|
struct subflow_send_info { |
|
struct sock *ssk; |
|
u64 ratio; |
|
}; |
|
|
|
static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) |
|
{ |
|
struct subflow_send_info send_info[2]; |
|
struct mptcp_subflow_context *subflow; |
|
int i, nr_active = 0; |
|
struct sock *ssk; |
|
u64 ratio; |
|
u32 pace; |
|
|
|
sock_owned_by_me((struct sock *)msk); |
|
|
|
if (__mptcp_check_fallback(msk)) { |
|
if (!msk->first) |
|
return NULL; |
|
return 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))) |
|
return msk->last_snd; |
|
|
|
/* pick the subflow with the lower wmem/wspace ratio */ |
|
for (i = 0; i < 2; ++i) { |
|
send_info[i].ssk = NULL; |
|
send_info[i].ratio = -1; |
|
} |
|
mptcp_for_each_subflow(msk, subflow) { |
|
ssk = mptcp_subflow_tcp_sock(subflow); |
|
if (!mptcp_subflow_active(subflow)) |
|
continue; |
|
|
|
nr_active += !subflow->backup; |
|
if (!sk_stream_memory_free(subflow->tcp_sock) || !tcp_sk(ssk)->snd_wnd) |
|
continue; |
|
|
|
pace = READ_ONCE(ssk->sk_pacing_rate); |
|
if (!pace) |
|
continue; |
|
|
|
ratio = div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, |
|
pace); |
|
if (ratio < send_info[subflow->backup].ratio) { |
|
send_info[subflow->backup].ssk = ssk; |
|
send_info[subflow->backup].ratio = ratio; |
|
} |
|
} |
|
|
|
pr_debug("msk=%p nr_active=%d ssk=%p:%lld backup=%p:%lld", |
|
msk, nr_active, send_info[0].ssk, send_info[0].ratio, |
|
send_info[1].ssk, send_info[1].ratio); |
|
|
|
/* pick the best backup if no other subflow is active */ |
|
if (!nr_active) |
|
send_info[0].ssk = send_info[1].ssk; |
|
|
|
if (send_info[0].ssk) { |
|
msk->last_snd = send_info[0].ssk; |
|
msk->snd_burst = min_t(int, MPTCP_SEND_BURST_SIZE, |
|
tcp_sk(msk->last_snd)->snd_wnd); |
|
return msk->last_snd; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static void mptcp_push_release(struct sock *sk, struct sock *ssk, |
|
struct mptcp_sendmsg_info *info) |
|
{ |
|
mptcp_set_timeout(sk, ssk); |
|
tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, info->size_goal); |
|
release_sock(ssk); |
|
} |
|
|
|
static 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, |
|
}; |
|
struct mptcp_data_frag *dfrag; |
|
int len, copied = 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; |
|
|
|
prev_ssk = ssk; |
|
__mptcp_flush_join_list(msk); |
|
ssk = mptcp_subflow_get_send(msk); |
|
|
|
/* try to keep the subflow socket lock across |
|
* consecutive xmit on the same socket |
|
*/ |
|
if (ssk != prev_ssk && prev_ssk) |
|
mptcp_push_release(sk, prev_ssk, &info); |
|
if (!ssk) |
|
goto out; |
|
|
|
if (ssk != prev_ssk || !prev_ssk) |
|
lock_sock(ssk); |
|
|
|
/* keep it simple and always provide a new skb for the |
|
* subflow, even if we will not use it when collapsing |
|
* on the pending one |
|
*/ |
|
if (!mptcp_alloc_tx_skb(sk, ssk)) { |
|
mptcp_push_release(sk, ssk, &info); |
|
goto out; |
|
} |
|
|
|
ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); |
|
if (ret <= 0) { |
|
mptcp_push_release(sk, ssk, &info); |
|
goto out; |
|
} |
|
|
|
info.sent += ret; |
|
dfrag->already_sent += ret; |
|
msk->snd_nxt += ret; |
|
msk->snd_burst -= ret; |
|
msk->tx_pending_data -= ret; |
|
copied += ret; |
|
len -= 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(sk, ssk, &info); |
|
|
|
out: |
|
if (copied) { |
|
/* start the timer, if it's not pending */ |
|
if (!mptcp_timer_pending(sk)) |
|
mptcp_reset_timer(sk); |
|
__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; |
|
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)); |
|
goto out; |
|
} |
|
|
|
if (unlikely(mptcp_must_reclaim_memory(sk, ssk))) { |
|
__mptcp_update_wmem(sk); |
|
sk_mem_reclaim_partial(sk); |
|
} |
|
if (!__mptcp_alloc_tx_skb(sk, ssk, GFP_ATOMIC)) |
|
goto out; |
|
|
|
ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); |
|
if (ret <= 0) |
|
goto out; |
|
|
|
info.sent += ret; |
|
dfrag->already_sent += ret; |
|
msk->snd_nxt += ret; |
|
msk->snd_burst -= ret; |
|
msk->tx_pending_data -= ret; |
|
copied += ret; |
|
len -= ret; |
|
first = false; |
|
} |
|
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() |
|
*/ |
|
__mptcp_update_wmem(sk); |
|
if (copied) { |
|
mptcp_set_timeout(sk, ssk); |
|
tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle, |
|
info.size_goal); |
|
if (!mptcp_timer_pending(sk)) |
|
mptcp_reset_timer(sk); |
|
|
|
if (msk->snd_data_fin_enable && |
|
msk->snd_nxt + 1 == msk->write_seq) |
|
mptcp_schedule_work(sk); |
|
} |
|
} |
|
|
|
static void mptcp_set_nospace(struct sock *sk) |
|
{ |
|
/* enable autotune */ |
|
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
|
|
|
/* will be cleared on avail space */ |
|
set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags); |
|
} |
|
|
|
static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
struct page_frag *pfrag; |
|
size_t copied = 0; |
|
int ret = 0; |
|
long timeo; |
|
|
|
if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL)) |
|
return -EOPNOTSUPP; |
|
|
|
mptcp_lock_sock(sk, __mptcp_wmem_reserve(sk, min_t(size_t, 1 << 20, len))); |
|
|
|
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 out; |
|
} |
|
|
|
pfrag = sk_page_frag(sk); |
|
|
|
while (msg_data_left(msg)) { |
|
int total_ts, frag_truesize = 0; |
|
struct mptcp_data_frag *dfrag; |
|
struct sk_buff_head skbs; |
|
bool dfrag_collapsed; |
|
size_t psize, offset; |
|
|
|
if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) { |
|
ret = -EPIPE; |
|
goto out; |
|
} |
|
|
|
/* 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; |
|
__skb_queue_head_init(&skbs); |
|
if (!mptcp_tx_cache_refill(sk, psize, &skbs, &total_ts)) |
|
goto wait_for_memory; |
|
|
|
if (!mptcp_wmem_alloc(sk, total_ts)) { |
|
__skb_queue_purge(&skbs); |
|
goto wait_for_memory; |
|
} |
|
|
|
skb_queue_splice_tail(&skbs, &msk->skb_tx_cache); |
|
if (copy_page_from_iter(dfrag->page, offset, psize, |
|
&msg->msg_iter) != psize) { |
|
mptcp_wmem_uncharge(sk, psize + frag_truesize); |
|
ret = -EFAULT; |
|
goto out; |
|
} |
|
|
|
/* data successfully copied into the write queue */ |
|
copied += psize; |
|
dfrag->data_len += psize; |
|
frag_truesize += psize; |
|
pfrag->offset += frag_truesize; |
|
WRITE_ONCE(msk->write_seq, msk->write_seq + psize); |
|
msk->tx_pending_data += 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 out; |
|
} |
|
|
|
if (copied) |
|
__mptcp_push_pending(sk, msg->msg_flags); |
|
|
|
out: |
|
release_sock(sk); |
|
return copied ? : ret; |
|
} |
|
|
|
static void mptcp_wait_data(struct sock *sk, long *timeo) |
|
{ |
|
DEFINE_WAIT_FUNC(wait, woken_wake_function); |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
add_wait_queue(sk_sleep(sk), &wait); |
|
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
|
|
|
sk_wait_event(sk, timeo, |
|
test_and_clear_bit(MPTCP_DATA_READY, &msk->flags), &wait); |
|
|
|
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
|
remove_wait_queue(sk_sleep(sk), &wait); |
|
} |
|
|
|
static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, |
|
struct msghdr *msg, |
|
size_t len) |
|
{ |
|
struct sk_buff *skb; |
|
int copied = 0; |
|
|
|
while ((skb = skb_peek(&msk->receive_queue)) != NULL) { |
|
u32 offset = MPTCP_SKB_CB(skb)->offset; |
|
u32 data_len = skb->len - offset; |
|
u32 count = min_t(size_t, len - copied, data_len); |
|
int err; |
|
|
|
err = skb_copy_datagram_msg(skb, offset, msg, count); |
|
if (unlikely(err < 0)) { |
|
if (!copied) |
|
return err; |
|
break; |
|
} |
|
|
|
copied += count; |
|
|
|
if (count < data_len) { |
|
MPTCP_SKB_CB(skb)->offset += count; |
|
break; |
|
} |
|
|
|
/* we will bulk release the skb memory later */ |
|
skb->destructor = NULL; |
|
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 (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, |
|
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); |
|
sk_mem_uncharge(sk, msk->rmem_released); |
|
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; |
|
|
|
__mptcp_flush_join_list(msk); |
|
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); |
|
tcp_cleanup_rbuf(ssk, moved); |
|
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); |
|
mptcp_cleanup_rbuf(msk); |
|
} |
|
if (ret) |
|
mptcp_check_data_fin((struct sock *)msk); |
|
return !skb_queue_empty(&msk->receive_queue); |
|
} |
|
|
|
static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
|
int nonblock, int flags, int *addr_len) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
int copied = 0; |
|
int target; |
|
long timeo; |
|
|
|
if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT)) |
|
return -EOPNOTSUPP; |
|
|
|
mptcp_lock_sock(sk, __mptcp_splice_receive_queue(sk)); |
|
if (unlikely(sk->sk_state == TCP_LISTEN)) { |
|
copied = -ENOTCONN; |
|
goto out_err; |
|
} |
|
|
|
timeo = sock_rcvtimeo(sk, nonblock); |
|
|
|
len = min_t(size_t, len, INT_MAX); |
|
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); |
|
|
|
while (copied < len) { |
|
int bytes_read; |
|
|
|
bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied); |
|
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); |
|
mptcp_wait_data(sk, &timeo); |
|
} |
|
|
|
if (skb_queue_empty_lockless(&sk->sk_receive_queue) && |
|
skb_queue_empty(&msk->receive_queue)) { |
|
/* entire backlog drained, clear DATA_READY. */ |
|
clear_bit(MPTCP_DATA_READY, &msk->flags); |
|
|
|
/* .. race-breaker: ssk might have gotten new data |
|
* after last __mptcp_move_skbs() returned false. |
|
*/ |
|
if (unlikely(__mptcp_move_skbs(msk))) |
|
set_bit(MPTCP_DATA_READY, &msk->flags); |
|
} else if (unlikely(!test_bit(MPTCP_DATA_READY, &msk->flags))) { |
|
/* data to read but mptcp_wait_data() cleared DATA_READY */ |
|
set_bit(MPTCP_DATA_READY, &msk->flags); |
|
} |
|
out_err: |
|
pr_debug("msk=%p data_ready=%d rx queue empty=%d copied=%d", |
|
msk, test_bit(MPTCP_DATA_READY, &msk->flags), |
|
skb_queue_empty_lockless(&sk->sk_receive_queue), copied); |
|
mptcp_rcv_space_adjust(msk, copied); |
|
|
|
release_sock(sk); |
|
return copied; |
|
} |
|
|
|
static void mptcp_retransmit_handler(struct sock *sk) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
set_bit(MPTCP_WORK_RTX, &msk->flags); |
|
mptcp_schedule_work(sk); |
|
} |
|
|
|
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; |
|
|
|
bh_lock_sock(sk); |
|
if (!sock_owned_by_user(sk)) { |
|
mptcp_retransmit_handler(sk); |
|
} else { |
|
/* delegate our work to tcp_release_cb() */ |
|
if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, |
|
&sk->sk_tsq_flags)) |
|
sock_hold(sk); |
|
} |
|
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(const struct mptcp_sock *msk) |
|
{ |
|
struct mptcp_subflow_context *subflow; |
|
struct sock *backup = NULL; |
|
|
|
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? Don't retransmit. */ |
|
if (!tcp_write_queue_empty(ssk)) { |
|
if (inet_csk(ssk)->icsk_ca_state >= TCP_CA_Loss) |
|
continue; |
|
return NULL; |
|
} |
|
|
|
if (subflow->backup) { |
|
if (!backup) |
|
backup = ssk; |
|
continue; |
|
} |
|
|
|
return ssk; |
|
} |
|
|
|
return backup; |
|
} |
|
|
|
static void mptcp_dispose_initial_subflow(struct mptcp_sock *msk) |
|
{ |
|
if (msk->subflow) { |
|
iput(SOCK_INODE(msk->subflow)); |
|
msk->subflow = NULL; |
|
} |
|
} |
|
|
|
/* 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) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
list_del(&subflow->node); |
|
|
|
lock_sock_nested(ssk, SINGLE_DEPTH_NESTING); |
|
|
|
/* if we are invoked by the msk cleanup code, the subflow is |
|
* already orphaned |
|
*/ |
|
if (ssk->sk_socket) |
|
sock_orphan(ssk); |
|
|
|
subflow->disposable = 1; |
|
|
|
/* if ssk hit tcp_done(), tcp_cleanup_ulp() cleared the related ops |
|
* the ssk has been already destroyed, we just need to release the |
|
* reference owned by msk; |
|
*/ |
|
if (!inet_csk(ssk)->icsk_ulp_ops) { |
|
kfree_rcu(subflow, rcu); |
|
} else { |
|
/* otherwise tcp will dispose of the ssk and subflow ctx */ |
|
__tcp_close(ssk, 0); |
|
|
|
/* close acquired an extra ref */ |
|
__sock_put(ssk); |
|
} |
|
release_sock(ssk); |
|
|
|
sock_put(ssk); |
|
|
|
if (ssk == msk->last_snd) |
|
msk->last_snd = NULL; |
|
|
|
if (ssk == msk->ack_hint) |
|
msk->ack_hint = NULL; |
|
|
|
if (ssk == msk->first) |
|
msk->first = NULL; |
|
|
|
if (msk->subflow && ssk == msk->subflow->sk) |
|
mptcp_dispose_initial_subflow(msk); |
|
} |
|
|
|
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); |
|
__mptcp_close_ssk(sk, ssk, subflow); |
|
} |
|
|
|
static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) |
|
{ |
|
return 0; |
|
} |
|
|
|
static void __mptcp_close_subflow(struct mptcp_sock *msk) |
|
{ |
|
struct mptcp_subflow_context *subflow, *tmp; |
|
|
|
might_sleep(); |
|
|
|
list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { |
|
struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
|
|
|
if (inet_sk_state_load(ssk) != TCP_CLOSE) |
|
continue; |
|
|
|
/* 'subflow_data_ready' will re-sched once rx queue is empty */ |
|
if (!skb_queue_empty_lockless(&ssk->sk_receive_queue)) |
|
continue; |
|
|
|
mptcp_close_ssk((struct sock *)msk, ssk, subflow); |
|
} |
|
} |
|
|
|
static bool mptcp_check_close_timeout(const struct sock *sk) |
|
{ |
|
s32 delta = tcp_jiffies32 - inet_csk(sk)->icsk_mtup.probe_timestamp; |
|
struct mptcp_subflow_context *subflow; |
|
|
|
if (delta >= TCP_TIMEWAIT_LEN) |
|
return true; |
|
|
|
/* if all subflows are in closed status don't bother with additional |
|
* timeout |
|
*/ |
|
mptcp_for_each_subflow(mptcp_sk(sk), subflow) { |
|
if (inet_sk_state_load(mptcp_subflow_tcp_sock(subflow)) != |
|
TCP_CLOSE) |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
static void mptcp_check_fastclose(struct mptcp_sock *msk) |
|
{ |
|
struct mptcp_subflow_context *subflow, *tmp; |
|
struct sock *sk = &msk->sk.icsk_inet.sk; |
|
|
|
if (likely(!READ_ONCE(msk->rcv_fastclose))) |
|
return; |
|
|
|
mptcp_token_destroy(msk); |
|
|
|
list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { |
|
struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); |
|
|
|
lock_sock(tcp_sk); |
|
if (tcp_sk->sk_state != TCP_CLOSE) { |
|
tcp_send_active_reset(tcp_sk, GFP_ATOMIC); |
|
tcp_set_state(tcp_sk, TCP_CLOSE); |
|
} |
|
release_sock(tcp_sk); |
|
} |
|
|
|
inet_sk_state_store(sk, TCP_CLOSE); |
|
sk->sk_shutdown = SHUTDOWN_MASK; |
|
smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ |
|
set_bit(MPTCP_DATA_READY, &msk->flags); |
|
set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags); |
|
|
|
mptcp_close_wake_up(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); |
|
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; |
|
} |
|
|
|
return; |
|
} |
|
|
|
ssk = mptcp_subflow_get_retrans(msk); |
|
if (!ssk) |
|
goto reset_timer; |
|
|
|
lock_sock(ssk); |
|
|
|
/* limit retransmission to the bytes already sent on some subflows */ |
|
info.sent = 0; |
|
info.limit = dfrag->already_sent; |
|
while (info.sent < dfrag->already_sent) { |
|
if (!mptcp_alloc_tx_skb(sk, ssk)) |
|
break; |
|
|
|
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) |
|
tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle, |
|
info.size_goal); |
|
|
|
mptcp_set_timeout(sk, ssk); |
|
release_sock(ssk); |
|
|
|
reset_timer: |
|
if (!mptcp_timer_pending(sk)) |
|
mptcp_reset_timer(sk); |
|
} |
|
|
|
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; |
|
int state; |
|
|
|
lock_sock(sk); |
|
state = sk->sk_state; |
|
if (unlikely(state == TCP_CLOSE)) |
|
goto unlock; |
|
|
|
mptcp_check_data_fin_ack(sk); |
|
__mptcp_flush_join_list(msk); |
|
|
|
mptcp_check_fastclose(msk); |
|
|
|
if (msk->pm.status) |
|
mptcp_pm_nl_work(msk); |
|
|
|
if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags)) |
|
mptcp_check_for_eof(msk); |
|
|
|
__mptcp_check_send_data_fin(sk); |
|
mptcp_check_data_fin(sk); |
|
|
|
/* There is no point in keeping around an orphaned sk timedout or |
|
* closed, but we need the msk around to reply to incoming DATA_FIN, |
|
* even if it is orphaned and in FIN_WAIT2 state |
|
*/ |
|
if (sock_flag(sk, SOCK_DEAD) && |
|
(mptcp_check_close_timeout(sk) || sk->sk_state == TCP_CLOSE)) { |
|
inet_sk_state_store(sk, TCP_CLOSE); |
|
__mptcp_destroy_sock(sk); |
|
goto unlock; |
|
} |
|
|
|
if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) |
|
__mptcp_close_subflow(msk); |
|
|
|
if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags)) |
|
__mptcp_retrans(sk); |
|
|
|
unlock: |
|
release_sock(sk); |
|
sock_put(sk); |
|
} |
|
|
|
static int __mptcp_init_sock(struct sock *sk) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
spin_lock_init(&msk->join_list_lock); |
|
|
|
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); |
|
__skb_queue_head_init(&msk->skb_tx_cache); |
|
msk->out_of_order_queue = RB_ROOT; |
|
msk->first_pending = NULL; |
|
msk->wmem_reserved = 0; |
|
msk->rmem_released = 0; |
|
msk->tx_pending_data = 0; |
|
msk->size_goal_cache = TCP_BASE_MSS; |
|
|
|
msk->ack_hint = NULL; |
|
msk->first = NULL; |
|
inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss; |
|
|
|
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 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; |
|
|
|
sk_sockets_allocated_inc(sk); |
|
sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1]; |
|
sk->sk_sndbuf = 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; |
|
struct sk_buff *skb; |
|
|
|
WRITE_ONCE(msk->first_pending, NULL); |
|
list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) |
|
dfrag_clear(sk, dfrag); |
|
while ((skb = __skb_dequeue(&msk->skb_tx_cache)) != NULL) { |
|
sk->sk_forward_alloc += skb->truesize; |
|
kfree_skb(skb); |
|
} |
|
} |
|
|
|
static 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: |
|
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); |
|
} else { |
|
pr_debug("Sending DATA_FIN on subflow %p", ssk); |
|
mptcp_set_timeout(sk, 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); |
|
|
|
/* fallback socket will not get data_fin/ack, can move to the next |
|
* state now |
|
*/ |
|
if (__mptcp_check_fallback(msk)) { |
|
if ((1 << sk->sk_state) & (TCPF_CLOSING | TCPF_LAST_ACK)) { |
|
inet_sk_state_store(sk, TCP_CLOSE); |
|
mptcp_close_wake_up(sk); |
|
} else if (sk->sk_state == TCP_FIN_WAIT1) { |
|
inet_sk_state_store(sk, TCP_FIN_WAIT2); |
|
} |
|
} |
|
|
|
__mptcp_flush_join_list(msk); |
|
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_subflow_context *subflow, *tmp; |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
LIST_HEAD(conn_list); |
|
|
|
pr_debug("msk=%p", msk); |
|
|
|
might_sleep(); |
|
|
|
/* be sure to always acquire the join list lock, to sync vs |
|
* mptcp_finish_join(). |
|
*/ |
|
spin_lock_bh(&msk->join_list_lock); |
|
list_splice_tail_init(&msk->join_list, &msk->conn_list); |
|
spin_unlock_bh(&msk->join_list_lock); |
|
list_splice_init(&msk->conn_list, &conn_list); |
|
|
|
sk_stop_timer(sk, &msk->sk.icsk_retransmit_timer); |
|
sk_stop_timer(sk, &sk->sk_timer); |
|
msk->pm.status = 0; |
|
|
|
list_for_each_entry_safe(subflow, tmp, &conn_list, node) { |
|
struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
|
__mptcp_close_ssk(sk, ssk, subflow); |
|
} |
|
|
|
sk->sk_prot->destroy(sk); |
|
|
|
WARN_ON_ONCE(msk->wmem_reserved); |
|
WARN_ON_ONCE(msk->rmem_released); |
|
sk_stream_kill_queues(sk); |
|
xfrm_sk_free_policy(sk); |
|
sk_refcnt_debug_release(sk); |
|
mptcp_dispose_initial_subflow(msk); |
|
sock_put(sk); |
|
} |
|
|
|
static void mptcp_close(struct sock *sk, long timeout) |
|
{ |
|
struct mptcp_subflow_context *subflow; |
|
bool do_cancel_work = false; |
|
|
|
lock_sock(sk); |
|
sk->sk_shutdown = SHUTDOWN_MASK; |
|
|
|
if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) { |
|
inet_sk_state_store(sk, TCP_CLOSE); |
|
goto cleanup; |
|
} |
|
|
|
if (mptcp_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; |
|
list_for_each_entry(subflow, &mptcp_sk(sk)->conn_list, node) { |
|
struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
|
bool slow = lock_sock_fast(ssk); |
|
|
|
sock_orphan(ssk); |
|
unlock_sock_fast(ssk, slow); |
|
} |
|
sock_orphan(sk); |
|
|
|
sock_hold(sk); |
|
pr_debug("msk=%p state=%d", sk, sk->sk_state); |
|
if (sk->sk_state == TCP_CLOSE) { |
|
__mptcp_destroy_sock(sk); |
|
do_cancel_work = true; |
|
} else { |
|
sk_reset_timer(sk, &sk->sk_timer, jiffies + TCP_TIMEWAIT_LEN); |
|
} |
|
release_sock(sk); |
|
if (do_cancel_work) |
|
mptcp_cancel_work(sk); |
|
|
|
if (mptcp_sk(sk)->token) |
|
mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL); |
|
|
|
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_subflow_context *subflow; |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
__mptcp_flush_join_list(msk); |
|
mptcp_for_each_subflow(msk, subflow) { |
|
struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
|
|
|
lock_sock(ssk); |
|
tcp_disconnect(ssk, flags); |
|
release_sock(ssk); |
|
} |
|
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(const struct sock *sk, |
|
const struct mptcp_options_received *mp_opt, |
|
struct request_sock *req) |
|
{ |
|
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); |
|
struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC); |
|
struct mptcp_sock *msk; |
|
u64 ack_seq; |
|
|
|
if (!nsk) |
|
return NULL; |
|
|
|
#if IS_ENABLED(CONFIG_MPTCP_IPV6) |
|
if (nsk->sk_family == AF_INET6) |
|
inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk); |
|
#endif |
|
|
|
__mptcp_init_sock(nsk); |
|
|
|
msk = mptcp_sk(nsk); |
|
msk->local_key = subflow_req->local_key; |
|
msk->token = subflow_req->token; |
|
msk->subflow = NULL; |
|
WRITE_ONCE(msk->fully_established, false); |
|
|
|
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; |
|
|
|
if (mp_opt->mp_capable) { |
|
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); |
|
WRITE_ONCE(msk->rcv_wnd_sent, ack_seq); |
|
} |
|
|
|
sock_reset_flag(nsk, SOCK_RCU_FREE); |
|
/* will be fully established after successful MPC subflow creation */ |
|
inet_sk_state_store(nsk, TCP_SYN_RECV); |
|
|
|
security_inet_csk_clone(nsk, req); |
|
bh_unlock_sock(nsk); |
|
|
|
/* keep a single reference */ |
|
__sock_put(nsk); |
|
return nsk; |
|
} |
|
|
|
void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk) |
|
{ |
|
const struct tcp_sock *tp = tcp_sk(ssk); |
|
|
|
msk->rcvq_space.copied = 0; |
|
msk->rcvq_space.rtt_us = 0; |
|
|
|
msk->rcvq_space.time = tp->tcp_mstamp; |
|
|
|
/* initial rcv_space offering made to peer */ |
|
msk->rcvq_space.space = min_t(u32, tp->rcv_wnd, |
|
TCP_INIT_CWND * tp->advmss); |
|
if (msk->rcvq_space.space == 0) |
|
msk->rcvq_space.space = TCP_INIT_CWND * TCP_MSS_DEFAULT; |
|
|
|
WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd); |
|
} |
|
|
|
static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, |
|
bool kern) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
struct socket *listener; |
|
struct sock *newsk; |
|
|
|
listener = __mptcp_nmpc_socket(msk); |
|
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; |
|
return newsk; |
|
} |
|
|
|
/* acquire the 2nd reference for the owning socket */ |
|
sock_hold(new_mptcp_sock); |
|
newsk = new_mptcp_sock; |
|
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK); |
|
} else { |
|
MPTCP_INC_STATS(sock_net(sk), |
|
MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK); |
|
} |
|
|
|
return newsk; |
|
} |
|
|
|
void mptcp_destroy_common(struct mptcp_sock *msk) |
|
{ |
|
struct sock *sk = (struct sock *)msk; |
|
|
|
__mptcp_clear_xmit(sk); |
|
|
|
/* move to sk_receive_queue, sk_stream_kill_queues will purge it */ |
|
skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue); |
|
|
|
skb_rbtree_purge(&msk->out_of_order_queue); |
|
mptcp_token_destroy(msk); |
|
mptcp_pm_free_anno_list(msk); |
|
} |
|
|
|
static void mptcp_destroy(struct sock *sk) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
|
|
mptcp_destroy_common(msk); |
|
sk_sockets_allocated_dec(sk); |
|
} |
|
|
|
static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname, |
|
sockptr_t optval, unsigned int optlen) |
|
{ |
|
struct sock *sk = (struct sock *)msk; |
|
struct socket *ssock; |
|
int ret; |
|
|
|
switch (optname) { |
|
case SO_REUSEPORT: |
|
case SO_REUSEADDR: |
|
lock_sock(sk); |
|
ssock = __mptcp_nmpc_socket(msk); |
|
if (!ssock) { |
|
release_sock(sk); |
|
return -EINVAL; |
|
} |
|
|
|
ret = sock_setsockopt(ssock, SOL_SOCKET, optname, optval, optlen); |
|
if (ret == 0) { |
|
if (optname == SO_REUSEPORT) |
|
sk->sk_reuseport = ssock->sk->sk_reuseport; |
|
else if (optname == SO_REUSEADDR) |
|
sk->sk_reuse = ssock->sk->sk_reuse; |
|
} |
|
release_sock(sk); |
|
return ret; |
|
} |
|
|
|
return sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, optlen); |
|
} |
|
|
|
static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname, |
|
sockptr_t optval, unsigned int optlen) |
|
{ |
|
struct sock *sk = (struct sock *)msk; |
|
int ret = -EOPNOTSUPP; |
|
struct socket *ssock; |
|
|
|
switch (optname) { |
|
case IPV6_V6ONLY: |
|
lock_sock(sk); |
|
ssock = __mptcp_nmpc_socket(msk); |
|
if (!ssock) { |
|
release_sock(sk); |
|
return -EINVAL; |
|
} |
|
|
|
ret = tcp_setsockopt(ssock->sk, SOL_IPV6, optname, optval, optlen); |
|
if (ret == 0) |
|
sk->sk_ipv6only = ssock->sk->sk_ipv6only; |
|
|
|
release_sock(sk); |
|
break; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static bool mptcp_unsupported(int level, int optname) |
|
{ |
|
if (level == SOL_IP) { |
|
switch (optname) { |
|
case IP_ADD_MEMBERSHIP: |
|
case IP_ADD_SOURCE_MEMBERSHIP: |
|
case IP_DROP_MEMBERSHIP: |
|
case IP_DROP_SOURCE_MEMBERSHIP: |
|
case IP_BLOCK_SOURCE: |
|
case IP_UNBLOCK_SOURCE: |
|
case MCAST_JOIN_GROUP: |
|
case MCAST_LEAVE_GROUP: |
|
case MCAST_JOIN_SOURCE_GROUP: |
|
case MCAST_LEAVE_SOURCE_GROUP: |
|
case MCAST_BLOCK_SOURCE: |
|
case MCAST_UNBLOCK_SOURCE: |
|
case MCAST_MSFILTER: |
|
return true; |
|
} |
|
return false; |
|
} |
|
if (level == SOL_IPV6) { |
|
switch (optname) { |
|
case IPV6_ADDRFORM: |
|
case IPV6_ADD_MEMBERSHIP: |
|
case IPV6_DROP_MEMBERSHIP: |
|
case IPV6_JOIN_ANYCAST: |
|
case IPV6_LEAVE_ANYCAST: |
|
case MCAST_JOIN_GROUP: |
|
case MCAST_LEAVE_GROUP: |
|
case MCAST_JOIN_SOURCE_GROUP: |
|
case MCAST_LEAVE_SOURCE_GROUP: |
|
case MCAST_BLOCK_SOURCE: |
|
case MCAST_UNBLOCK_SOURCE: |
|
case MCAST_MSFILTER: |
|
return true; |
|
} |
|
return false; |
|
} |
|
return false; |
|
} |
|
|
|
static int mptcp_setsockopt(struct sock *sk, int level, int optname, |
|
sockptr_t optval, unsigned int optlen) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
struct sock *ssk; |
|
|
|
pr_debug("msk=%p", msk); |
|
|
|
if (mptcp_unsupported(level, optname)) |
|
return -ENOPROTOOPT; |
|
|
|
if (level == SOL_SOCKET) |
|
return mptcp_setsockopt_sol_socket(msk, optname, optval, optlen); |
|
|
|
/* @@ the meaning of setsockopt() when the socket is connected and |
|
* there are multiple subflows is not yet defined. It is up to the |
|
* MPTCP-level socket to configure the subflows until the subflow |
|
* is in TCP fallback, when TCP socket options are passed through |
|
* to the one remaining subflow. |
|
*/ |
|
lock_sock(sk); |
|
ssk = __mptcp_tcp_fallback(msk); |
|
release_sock(sk); |
|
if (ssk) |
|
return tcp_setsockopt(ssk, level, optname, optval, optlen); |
|
|
|
if (level == SOL_IPV6) |
|
return mptcp_setsockopt_v6(msk, optname, optval, optlen); |
|
|
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static int mptcp_getsockopt(struct sock *sk, int level, int optname, |
|
char __user *optval, int __user *option) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sk); |
|
struct sock *ssk; |
|
|
|
pr_debug("msk=%p", msk); |
|
|
|
/* @@ the meaning of setsockopt() when the socket is connected and |
|
* there are multiple subflows is not yet defined. It is up to the |
|
* MPTCP-level socket to configure the subflows until the subflow |
|
* is in TCP fallback, when socket options are passed through |
|
* to the one remaining subflow. |
|
*/ |
|
lock_sock(sk); |
|
ssk = __mptcp_tcp_fallback(msk); |
|
release_sock(sk); |
|
if (ssk) |
|
return tcp_getsockopt(ssk, level, optname, optval, option); |
|
|
|
return -EOPNOTSUPP; |
|
} |
|
|
|
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)->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)); |
|
} else { |
|
set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags); |
|
} |
|
} |
|
|
|
#define MPTCP_DEFERRED_ALL (TCPF_WRITE_TIMER_DEFERRED) |
|
|
|
/* processes deferred events and flush wmem */ |
|
static void mptcp_release_cb(struct sock *sk) |
|
{ |
|
unsigned long flags, nflags; |
|
|
|
for (;;) { |
|
flags = 0; |
|
if (test_and_clear_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags)) |
|
flags |= BIT(MPTCP_PUSH_PENDING); |
|
if (!flags) |
|
break; |
|
|
|
/* 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 |
|
*/ |
|
|
|
spin_unlock_bh(&sk->sk_lock.slock); |
|
if (flags & BIT(MPTCP_PUSH_PENDING)) |
|
__mptcp_push_pending(sk, 0); |
|
|
|
cond_resched(); |
|
spin_lock_bh(&sk->sk_lock.slock); |
|
} |
|
|
|
if (test_and_clear_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->flags)) |
|
__mptcp_clean_una_wakeup(sk); |
|
if (test_and_clear_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->flags)) |
|
__mptcp_error_report(sk); |
|
|
|
/* push_pending may touch wmem_reserved, ensure we do the cleanup |
|
* later |
|
*/ |
|
__mptcp_update_wmem(sk); |
|
__mptcp_update_rmem(sk); |
|
|
|
do { |
|
flags = sk->sk_tsq_flags; |
|
if (!(flags & MPTCP_DEFERRED_ALL)) |
|
return; |
|
nflags = flags & ~MPTCP_DEFERRED_ALL; |
|
} while (cmpxchg(&sk->sk_tsq_flags, flags, nflags) != flags); |
|
|
|
sock_release_ownership(sk); |
|
|
|
if (flags & TCPF_WRITE_TIMER_DEFERRED) { |
|
mptcp_retransmit_handler(sk); |
|
__sock_put(sk); |
|
} |
|
} |
|
|
|
void mptcp_subflow_process_delegated(struct sock *ssk) |
|
{ |
|
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); |
|
struct sock *sk = subflow->conn; |
|
|
|
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)->flags); |
|
mptcp_data_unlock(sk); |
|
mptcp_subflow_delegated_done(subflow); |
|
} |
|
|
|
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 = __mptcp_nmpc_socket(msk); |
|
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->rcv_wnd_sent, ack_seq); |
|
WRITE_ONCE(msk->can_ack, 1); |
|
WRITE_ONCE(msk->snd_una, msk->write_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; |
|
struct socket *parent_sock; |
|
bool ret; |
|
|
|
pr_debug("msk=%p, subflow=%p", msk, subflow); |
|
|
|
/* mptcp socket already closing? */ |
|
if (!mptcp_is_fully_established(parent)) |
|
return false; |
|
|
|
if (!msk->pm.server_side) |
|
goto out; |
|
|
|
if (!mptcp_pm_allow_new_subflow(msk)) |
|
return false; |
|
|
|
/* active connections are already on conn_list, and we can't acquire |
|
* msk lock here. |
|
* use the join list lock as synchronization point and double-check |
|
* msk status to avoid racing with __mptcp_destroy_sock() |
|
*/ |
|
spin_lock_bh(&msk->join_list_lock); |
|
ret = inet_sk_state_load(parent) == TCP_ESTABLISHED; |
|
if (ret && !WARN_ON_ONCE(!list_empty(&subflow->node))) { |
|
list_add_tail(&subflow->node, &msk->join_list); |
|
sock_hold(ssk); |
|
} |
|
spin_unlock_bh(&msk->join_list_lock); |
|
if (!ret) |
|
return false; |
|
|
|
/* attach to msk socket only after we are sure he will deal with us |
|
* at close time |
|
*/ |
|
parent_sock = READ_ONCE(parent->sk_socket); |
|
if (parent_sock && !ssk->sk_socket) |
|
mptcp_sock_graft(ssk, parent_sock); |
|
subflow->map_seq = READ_ONCE(msk->ack_seq); |
|
out: |
|
mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC); |
|
return true; |
|
} |
|
|
|
static void mptcp_shutdown(struct sock *sk, int how) |
|
{ |
|
pr_debug("sk=%p, how=%d", sk, how); |
|
|
|
if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk)) |
|
__mptcp_wr_shutdown(sk); |
|
} |
|
|
|
static struct proto mptcp_prot = { |
|
.name = "MPTCP", |
|
.owner = THIS_MODULE, |
|
.init = mptcp_init_sock, |
|
.disconnect = mptcp_disconnect, |
|
.close = mptcp_close, |
|
.accept = mptcp_accept, |
|
.setsockopt = mptcp_setsockopt, |
|
.getsockopt = mptcp_getsockopt, |
|
.shutdown = mptcp_shutdown, |
|
.destroy = mptcp_destroy, |
|
.sendmsg = mptcp_sendmsg, |
|
.recvmsg = mptcp_recvmsg, |
|
.release_cb = mptcp_release_cb, |
|
.hash = mptcp_hash, |
|
.unhash = mptcp_unhash, |
|
.get_port = mptcp_get_port, |
|
.sockets_allocated = &mptcp_sockets_allocated, |
|
.memory_allocated = &tcp_memory_allocated, |
|
.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 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_stream_connect(struct socket *sock, struct sockaddr *uaddr, |
|
int addr_len, int flags) |
|
{ |
|
struct mptcp_sock *msk = mptcp_sk(sock->sk); |
|
struct mptcp_subflow_context *subflow; |
|
struct socket *ssock; |
|
int err; |
|
|
|
lock_sock(sock->sk); |
|
if (sock->state != SS_UNCONNECTED && msk->subflow) { |
|
/* pending connection or invalid state, let existing subflow |
|
* cope with that |
|
*/ |
|
ssock = msk->subflow; |
|
goto do_connect; |
|
} |
|
|
|
ssock = __mptcp_nmpc_socket(msk); |
|
if (!ssock) { |
|
err = -EINVAL; |
|
goto unlock; |
|
} |
|
|
|
mptcp_token_destroy(msk); |
|
inet_sk_state_store(sock->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_subflow_early_fallback(msk, subflow); |
|
|
|
do_connect: |
|
err = ssock->ops->connect(ssock, uaddr, addr_len, flags); |
|
sock->state = ssock->state; |
|
|
|
/* on successful connect, the msk state will be moved to established by |
|
* subflow_finish_connect() |
|
*/ |
|
if (!err || err == -EINPROGRESS) |
|
mptcp_copy_inaddrs(sock->sk, ssock->sk); |
|
else |
|
inet_sk_state_store(sock->sk, inet_sk_state_load(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 socket *ssock; |
|
int err; |
|
|
|
pr_debug("msk=%p", msk); |
|
|
|
lock_sock(sock->sk); |
|
ssock = __mptcp_nmpc_socket(msk); |
|
if (!ssock) { |
|
err = -EINVAL; |
|
goto unlock; |
|
} |
|
|
|
mptcp_token_destroy(msk); |
|
inet_sk_state_store(sock->sk, TCP_LISTEN); |
|
sock_set_flag(sock->sk, SOCK_RCU_FREE); |
|
|
|
err = ssock->ops->listen(ssock, backlog); |
|
inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); |
|
if (!err) |
|
mptcp_copy_inaddrs(sock->sk, ssock->sk); |
|
|
|
unlock: |
|
release_sock(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); |
|
|
|
lock_sock(sock->sk); |
|
if (sock->sk->sk_state != TCP_LISTEN) |
|
goto unlock_fail; |
|
|
|
ssock = __mptcp_nmpc_socket(msk); |
|
if (!ssock) |
|
goto unlock_fail; |
|
|
|
clear_bit(MPTCP_DATA_READY, &msk->flags); |
|
sock_hold(ssock->sk); |
|
release_sock(sock->sk); |
|
|
|
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; |
|
|
|
lock_sock(newsk); |
|
|
|
/* PM/worker can now acquire the first subflow socket |
|
* lock without racing with listener queue cleanup, |
|
* we can notify it, if needed. |
|
* |
|
* Even if remote has reset the initial subflow by now |
|
* the refcnt is still at least one. |
|
*/ |
|
subflow = mptcp_subflow_ctx(msk->first); |
|
list_add(&subflow->node, &msk->conn_list); |
|
sock_hold(msk->first); |
|
if (mptcp_is_fully_established(newsk)) |
|
mptcp_pm_fully_established(msk, msk->first, GFP_KERNEL); |
|
|
|
mptcp_copy_inaddrs(newsk, msk->first); |
|
mptcp_rcv_space_init(msk, msk->first); |
|
mptcp_propagate_sndbuf(newsk, msk->first); |
|
|
|
/* set ssk->sk_socket of accept()ed flows to mptcp socket. |
|
* This is needed so NOSPACE flag can be set from tcp stack. |
|
*/ |
|
__mptcp_flush_join_list(msk); |
|
mptcp_for_each_subflow(msk, subflow) { |
|
struct sock *ssk = mptcp_subflow_tcp_sock(subflow); |
|
|
|
if (!ssk->sk_socket) |
|
mptcp_sock_graft(ssk, newsock); |
|
} |
|
release_sock(newsk); |
|
} |
|
|
|
if (inet_csk_listen_poll(ssock->sk)) |
|
set_bit(MPTCP_DATA_READY, &msk->flags); |
|
sock_put(ssock->sk); |
|
return err; |
|
|
|
unlock_fail: |
|
release_sock(sock->sk); |
|
return -EINVAL; |
|
} |
|
|
|
static __poll_t mptcp_check_readable(struct mptcp_sock *msk) |
|
{ |
|
return test_bit(MPTCP_DATA_READY, &msk->flags) ? EPOLLIN | EPOLLRDNORM : |
|
0; |
|
} |
|
|
|
static __poll_t mptcp_check_writeable(struct mptcp_sock *msk) |
|
{ |
|
struct sock *sk = (struct sock *)msk; |
|
|
|
if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) |
|
return EPOLLOUT | EPOLLWRNORM; |
|
|
|
if (sk_stream_is_writeable(sk)) |
|
return EPOLLOUT | EPOLLWRNORM; |
|
|
|
mptcp_set_nospace(sk); |
|
smp_mb__after_atomic(); /* msk->flags is changed by write_space cb */ |
|
if (sk_stream_is_writeable(sk)) |
|
return EPOLLOUT | EPOLLWRNORM; |
|
|
|
return 0; |
|
} |
|
|
|
static __poll_t mptcp_poll(struct file *file, struct socket *sock, |
|
struct poll_table_struct *wait) |
|
{ |
|
struct sock *sk = sock->sk; |
|
struct mptcp_sock *msk; |
|
__poll_t mask = 0; |
|
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) |
|
return mptcp_check_readable(msk); |
|
|
|
if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) { |
|
mask |= mptcp_check_readable(msk); |
|
mask |= mptcp_check_writeable(msk); |
|
} |
|
if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE) |
|
mask |= EPOLLHUP; |
|
if (sk->sk_shutdown & RCV_SHUTDOWN) |
|
mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; |
|
|
|
/* This barrier is coupled with smp_wmb() in tcp_reset() */ |
|
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 = mptcp_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_tx_napi_add(&mptcp_napi_dev, &delegated->napi, mptcp_napi_poll, |
|
NAPI_POLL_WEIGHT); |
|
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 = mptcp_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 void mptcp_v6_destroy(struct sock *sk) |
|
{ |
|
mptcp_destroy(sk); |
|
inet6_destroy_sock(sk); |
|
} |
|
|
|
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.destroy = mptcp_v6_destroy; |
|
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
|
|
|