diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c index ef65e2df709f..2569385bab7c 100644 --- a/net/mptcp/mib.c +++ b/net/mptcp/mib.c @@ -87,6 +87,7 @@ static const struct snmp_mib mptcp_snmp_list[] = { SNMP_MIB_ITEM("WinProbe", MPTCP_MIB_WINPROBE), SNMP_MIB_ITEM("BacklogDrop", MPTCP_MIB_BACKLOGDROP), SNMP_MIB_ITEM("RcvPruned", MPTCP_MIB_RCVPRUNED), + SNMP_MIB_ITEM("OFOPruned", MPTCP_MIB_OFOPRUNED), }; /* mptcp_mib_alloc - allocate percpu mib counters diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h index 9271205f682e..3a3425e258a7 100644 --- a/net/mptcp/mib.h +++ b/net/mptcp/mib.h @@ -90,6 +90,7 @@ enum linux_mptcp_mib_field { MPTCP_MIB_WINPROBE, /* MPTCP-level zero window probe */ MPTCP_MIB_BACKLOGDROP, /* Backlog over memory limit */ MPTCP_MIB_RCVPRUNED, /* Dropped due to memory constraints */ + MPTCP_MIB_OFOPRUNED, /* MPTCP-level OoO queue pruned */ __MPTCP_MIB_MAX }; diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 63f2c18bc01f..ec874d2ead6a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -242,6 +242,65 @@ static bool mptcp_rcvbuf_grow(struct sock *sk, u32 newval) return false; } +/* "Inspired" from the TCP version; main difference: stop as soon as the MPTCP + * socket is under memory limit. + */ +static void mptcp_prune_ofo_queue(struct sock *sk, + const struct sk_buff *in_skb) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + struct rb_node *node, *prev; + bool pruned = false; + u64 mem; + + if (RB_EMPTY_ROOT(&msk->out_of_order_queue)) + return; + + node = &msk->ooo_last_skb->rbnode; + + do { + struct sk_buff *skb = rb_to_skb(node); + + /* Stop pruning if the incoming skb would land in OoO tail. */ + if (after64(MPTCP_SKB_CB(in_skb)->map_seq, + MPTCP_SKB_CB(skb)->map_seq)) + break; + + pruned = true; + prev = rb_prev(node); + rb_erase(node, &msk->out_of_order_queue); + mptcp_drop(sk, skb); + msk->ooo_last_skb = rb_to_skb(prev); + + mem = (unsigned int)sk_rmem_alloc_get(sk); + if (mem <= sk->sk_rcvbuf) + break; + + node = prev; + } while (node); + + if (pruned) + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOPRUNED); +} + +/* The stack can't drop packets for fallback socket at the msk level, or the + * stream will break. + */ +static bool mptcp_can_ingest(const struct sock *sk) +{ + return unlikely(sk_rmem_alloc_get(sk) <= READ_ONCE(sk->sk_rcvbuf)) || + __mptcp_check_fallback(mptcp_sk(sk)); +} + +static bool mptcp_try_rmem_schedule(struct sock *sk, const struct sk_buff *skb) +{ + if (!mptcp_can_ingest(sk)) { + mptcp_prune_ofo_queue(sk, skb); + return mptcp_can_ingest(sk); + } + return true; +} + /* "inspired" by tcp_data_queue_ofo(), main differences: * - use mptcp seqs * - don't cope with sacks @@ -253,6 +312,12 @@ static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb) u64 seq, end_seq, max_seq; struct sk_buff *skb1; + if (!mptcp_try_rmem_schedule(sk, skb)) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED); + mptcp_drop(sk, skb); + return; + } + seq = MPTCP_SKB_CB(skb)->map_seq; end_seq = MPTCP_SKB_CB(skb)->end_seq; max_seq = atomic64_read(&msk->rcv_wnd_sent); @@ -387,19 +452,15 @@ static bool __mptcp_move_skb(struct sock *sk, struct sk_buff *skb) mptcp_borrow_fwdmem(sk, skb); - /* Can't drop packets for fallback socket this late, or the stream - * will break. - */ - if (unlikely(sk_rmem_alloc_get(sk) > READ_ONCE(sk->sk_rcvbuf)) && - !__mptcp_check_fallback(msk)) { - MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED); - mptcp_drop(sk, skb); - return false; - } - if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) { /* in sequence */ insert: + if (!mptcp_try_rmem_schedule(sk, skb)) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED); + mptcp_drop(sk, skb); + return false; + } + msk->bytes_received += copy_len; WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len); tail = skb_peek_tail(&sk->sk_receive_queue);