From 1e39e5a32ad7fdd82d6e071aa14ecd511eedc1f7 Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Fri, 22 Apr 2022 14:55:39 -0700 Subject: mptcp: infinite mapping sending This patch adds the infinite mapping sending logic. Add a new flag send_infinite_map in struct mptcp_subflow_context. Set it true when a single contiguous subflow is in use and the allow_infinite_fallback flag is true in mptcp_pm_mp_fail_received(). In mptcp_sendmsg_frag(), if this flag is true, call the new function mptcp_update_infinite_map() to set the infinite mapping. Add a new flag infinite_map in struct mptcp_ext, set it true in mptcp_update_infinite_map(), and check this flag in a new helper mptcp_check_infinite_map(). In mptcp_update_infinite_map(), set data_len to 0, and clear the send_infinite_map flag, then do fallback. In mptcp_established_options(), use the helper mptcp_check_infinite_map() to let the infinite mapping DSS can be sent out in the fallback mode. Suggested-by: Paolo Abeni Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/options.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/mptcp/options.c') diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 325383646f5c..88f4ebbd6515 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -825,7 +825,7 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, opts->suboptions = 0; - if (unlikely(__mptcp_check_fallback(msk))) + if (unlikely(__mptcp_check_fallback(msk) && !mptcp_check_infinite_map(skb))) return false; if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) { @@ -1340,8 +1340,12 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, put_unaligned_be32(mpext->subflow_seq, ptr); ptr += 1; if (opts->csum_reqd) { + /* data_len == 0 is reserved for the infinite mapping, + * the checksum will also be set to 0. + */ put_unaligned_be32(mpext->data_len << 16 | - mptcp_make_csum(mpext), ptr); + (mpext->data_len ? mptcp_make_csum(mpext) : 0), + ptr); } else { put_unaligned_be32(mpext->data_len << 16 | TCPOPT_NOP << 8 | TCPOPT_NOP, ptr); -- cgit v1.2.3