diff --git a/include/net/mptcp.h b/include/net/mptcp.h index 326043c29c0a..0573ae75c3db 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -8,6 +8,7 @@ #ifndef __NET_MPTCP_H #define __NET_MPTCP_H +#include #include /* MPTCP sk_buff extension data */ @@ -25,4 +26,60 @@ struct mptcp_ext { /* one byte hole */ }; +#ifdef CONFIG_MPTCP + +/* move the skb extension owership, with the assumption that 'to' is + * newly allocated + */ +static inline void mptcp_skb_ext_move(struct sk_buff *to, + struct sk_buff *from) +{ + if (!skb_ext_exist(from, SKB_EXT_MPTCP)) + return; + + if (WARN_ON_ONCE(to->active_extensions)) + skb_ext_put(to); + + to->active_extensions = from->active_extensions; + to->extensions = from->extensions; + from->active_extensions = 0; +} + +static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext, + const struct mptcp_ext *from_ext) +{ + /* MPTCP always clears the ext when adding it to the skb, so + * holes do not bother us here + */ + return !from_ext || + (to_ext && from_ext && + !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext))); +} + +/* check if skbs can be collapsed. + * MPTCP collapse is allowed if neither @to or @from carry an mptcp data + * mapping, or if the extension of @to is the same as @from. + * Collapsing is not possible if @to lacks an extension, but @from carries one. + */ +static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, + const struct sk_buff *from) +{ + return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP), + skb_ext_find(from, SKB_EXT_MPTCP)); +} + +#else + +static inline void mptcp_skb_ext_move(struct sk_buff *to, + const struct sk_buff *from) +{ +} + +static inline bool mptcp_skb_can_collapse(const struct sk_buff *to, + const struct sk_buff *from) +{ + return true; +} + +#endif /* CONFIG_MPTCP */ #endif /* __NET_MPTCP_H */ diff --git a/include/net/tcp.h b/include/net/tcp.h index ac52633e7061..13bc83fab454 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -978,6 +979,13 @@ static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) return likely(!TCP_SKB_CB(skb)->eor); } +static inline bool tcp_skb_can_collapse(const struct sk_buff *to, + const struct sk_buff *from) +{ + return likely(tcp_skb_can_collapse_to(to) && + mptcp_skb_can_collapse(to, from)); +} + /* Events passed to congestion control interface */ enum tcp_ca_event { CA_EVENT_TX_START, /* first transmit when no packets in flight */ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 062b696a5fa1..2914fdf1d543 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1422,7 +1422,7 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb, if ((TCP_SKB_CB(prev)->sacked & TCPCB_TAGBITS) != TCPCB_SACKED_ACKED) goto fallback; - if (!tcp_skb_can_collapse_to(prev)) + if (!tcp_skb_can_collapse(prev, skb)) goto fallback; in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq) && @@ -4423,6 +4423,9 @@ static bool tcp_try_coalesce(struct sock *sk, if (TCP_SKB_CB(from)->seq != TCP_SKB_CB(to)->end_seq) return false; + if (!mptcp_skb_can_collapse(to, from)) + return false; + #ifdef CONFIG_TLS_DEVICE if (from->decrypted != to->decrypted) return false; @@ -4932,7 +4935,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, /* The first skb to collapse is: * - not SYN/FIN and * - bloated or contains data before "start" or - * overlaps to the next one. + * overlaps to the next one and mptcp allow collapsing. */ if (!(TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)) && (tcp_win_from_space(sk, skb->truesize) > skb->len || @@ -4941,7 +4944,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, break; } - if (n && n != tail && + if (n && n != tail && mptcp_skb_can_collapse(skb, n) && TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(n)->seq) { end_of_skbs = false; break; @@ -4974,6 +4977,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, else __skb_queue_tail(&tmp, nskb); /* defer rbtree insertion */ skb_set_owner_r(nskb, sk); + mptcp_skb_ext_move(nskb, skb); /* Copy data, releasing collapsed skbs. */ while (copy > 0) { @@ -4993,6 +4997,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, skb = tcp_collapse_one(sk, skb, list, root); if (!skb || skb == tail || + !mptcp_skb_can_collapse(nskb, skb) || (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN))) goto end; #ifdef CONFIG_TLS_DEVICE diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 58c92a7d671c..3ce7fe1c4076 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2865,7 +2865,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to, if (!tcp_can_collapse(sk, skb)) break; - if (!tcp_skb_can_collapse_to(to)) + if (!tcp_skb_can_collapse(to, skb)) break; space -= skb->len;