From: Dmytro SHYTYI <dmytro@shytyi.net>
To: mptcp@lists.linux.dev
Cc: Dmytro SHYTYI <dmytro@shytyi.net>
Subject: [RFC PATCH mptcp-next v4] mptcp: Fast Open Mechanism
Date: Mon, 1 Aug 2022 03:46:56 +0100 [thread overview]
Message-ID: <20220801024656.397714-1-dmytro@shytyi.net> (raw)
This set of patches will bring "Fast Open" Option support to MPTCP.
The aim of Fast Open Mechanism is to eliminate one round trip
time from a TCP conversation by allowing data to be included as
part of the SYN segment that initiates the connection.
IETF RFC 8684: Appendix B. TCP Fast Open and MPTCP.
[PATCH v3] includes "client-server" partial support for :
1. MPTCP cookie request from client (seems to be working).
2. MPTCP cookie offering from server (seems to be working).
3. MPTCP SYN+DATA+COOKIE from client (seems to be working).
4. subsequent write + read on the opened socket (first launch
with TFO request seems to be working, hovewer the second launch
appears to have a mptcp "RST" issue).
This patch is Work In Progress transitional draft.
The differences between v3 and v4:
1. An attempt to reduce impact on existing TCP code.
2. 2 files related to mptcp_fastopen are created(*.h + *.c).
3. "subflow_v4_conn_request" is used to call "mptcp_conn_request"(
located in "mptcp_fastopen.c") to process the received packet on the
listener side when "SYN" is received during 3way handshake.
4. This chain adds "skb" to "&msk->sk_receive_queue"
("subflow_v4_conn_request"->"mptcp_conn_request"->
"mptcp_try_fastopen"->"mptcp_fastopen_create_child"->
"mptcp_fastopen_add_skb")
5. Some minor comments from mailing list are not yet included
in the current version of the PATCH.
Signed-off-by: Dmytro SHYTYI <dmytro@shytyi.net>
---
include/net/mptcp.h | 2 +-
net/ipv4/tcp_output.c | 3 +-
net/mptcp/Makefile | 2 +-
net/mptcp/mptcp_fastopen.c | 476 +++++++++++++++++++++++++++++++++++++
net/mptcp/mptcp_fastopen.h | 67 ++++++
net/mptcp/options.c | 7 +-
net/mptcp/protocol.c | 8 +-
net/mptcp/protocol.h | 3 +
net/mptcp/sockopt.c | 41 ++++
net/mptcp/subflow.c | 7 +-
10 files changed, 604 insertions(+), 12 deletions(-)
create mode 100644 net/mptcp/mptcp_fastopen.c
create mode 100644 net/mptcp/mptcp_fastopen.h
diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 6456ea26e4c7..692197187af8 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -139,7 +139,7 @@ void mptcp_space(const struct sock *ssk, int *space, int *full_space);
bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
unsigned int *size, struct mptcp_out_options *opts);
bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
- struct mptcp_out_options *opts);
+ struct mptcp_out_options *opts, u16 *tcp_options);
bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
unsigned int *size, unsigned int remaining,
struct mptcp_out_options *opts);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b4b2284ed4a2..864517e63bdf 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -747,7 +747,7 @@ static void mptcp_set_option_cond(const struct request_sock *req,
if (rsk_is_mptcp(req)) {
unsigned int size;
- if (mptcp_synack_options(req, &size, &opts->mptcp)) {
+ if (mptcp_synack_options(req, &size, &opts->mptcp, &opts->options)) {
if (*remaining >= size) {
opts->options |= OPTION_MPTCP;
*remaining -= size;
@@ -822,7 +822,6 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
tp->syn_fastopen_exp = fastopen->cookie.exp ? 1 : 0;
}
}
-
smc_set_option(tp, opts, &remaining);
if (sk_is_mptcp(sk)) {
diff --git a/net/mptcp/Makefile b/net/mptcp/Makefile
index 8a7f68efa35f..0f1022b395ef 100644
--- a/net/mptcp/Makefile
+++ b/net/mptcp/Makefile
@@ -2,7 +2,7 @@
obj-$(CONFIG_MPTCP) += mptcp.o
mptcp-y := protocol.o subflow.o options.o token.o crypto.o ctrl.o pm.o diag.o \
- mib.o pm_netlink.o sockopt.o pm_userspace.o sched.o
+ mib.o pm_netlink.o sockopt.o pm_userspace.o sched.o mptcp_fastopen.o
obj-$(CONFIG_SYN_COOKIES) += syncookies.o
obj-$(CONFIG_INET_MPTCP_DIAG) += mptcp_diag.o
diff --git a/net/mptcp/mptcp_fastopen.c b/net/mptcp/mptcp_fastopen.c
new file mode 100644
index 000000000000..cca086e178a6
--- /dev/null
+++ b/net/mptcp/mptcp_fastopen.c
@@ -0,0 +1,476 @@
+#include "mptcp_fastopen.h"
+
+int mptcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
+ size_t len, struct mptcp_sock *msk,
+ size_t *copied)
+{
+ const struct iphdr *iph;
+ struct ubuf_info *uarg;
+ struct sockaddr *uaddr;
+ struct sk_buff *skb;
+ struct tcp_sock *tp;
+ struct socket *ssk;
+ int ret;
+
+ ssk = __mptcp_nmpc_socket(msk);
+ if (unlikely(!ssk))
+ goto out_EFAULT;
+ skb = tcp_stream_alloc_skb(ssk->sk, 0, ssk->sk->sk_allocation, true);
+ if (unlikely(!skb))
+ goto out_EFAULT;
+ iph = ip_hdr(skb);
+ if (unlikely(!iph))
+ goto out_EFAULT;
+ uarg = msg_zerocopy_realloc(sk, len, skb_zcopy(skb));
+ if (unlikely(!uarg))
+ goto out_EFAULT;
+ uaddr = msg->msg_name;
+
+ tp = tcp_sk(ssk->sk);
+ if (unlikely(!tp))
+ goto out_EFAULT;
+ if (!tp->fastopen_req)
+ tp->fastopen_req = kzalloc(sizeof(*tp->fastopen_req),
+ ssk->sk->sk_allocation);
+
+ if (unlikely(!tp->fastopen_req))
+ goto out_EFAULT;
+ tp->fastopen_req->data = msg;
+ tp->fastopen_req->size = len;
+ tp->fastopen_req->uarg = uarg;
+
+ /* requests a cookie */
+ *copied = mptcp_stream_connect(sk->sk_socket, uaddr,
+ msg->msg_namelen, msg->msg_flags);
+
+ return 0;
+out_EFAULT:
+ ret = -EFAULT;
+ return ret;
+}
+
+void mptcp_reqsk_record_syn(const struct sock *sk,
+ struct request_sock *req,
+ const struct sk_buff *skb)
+{
+ if (tcp_sk(sk)->save_syn) {
+ u32 length = skb_network_header_len(skb) + tcp_hdrlen(skb);
+ struct saved_syn *svd_syn;
+ u32 mac_headerlen;
+ void *base;
+
+ if (tcp_sk(sk)->save_syn == 2) {
+ base = skb_mac_header(skb);
+ mac_headerlen = skb_mac_header_len(skb);
+ length += mac_headerlen;
+ } else {
+ base = skb_network_header(skb);
+ mac_headerlen = 0;
+ }
+
+ svd_syn = kmalloc(struct_size(svd_syn, data, length),
+ GFP_ATOMIC);
+ if (svd_syn) {
+ svd_syn->mac_hdrlen = mac_headerlen;
+ svd_syn->network_hdrlen = skb_network_header_len(skb);
+ svd_syn->tcp_hdrlen = tcp_hdrlen(skb);
+ memcpy(svd_syn->data, base, length);
+ req->saved_syn = svd_syn;
+ }
+ }
+}
+
+void mptcp_ecn_create_request(struct request_sock *req,
+ const struct sk_buff *skb,
+ const struct sock *listen_sk,
+ const struct dst_entry *dst)
+{
+ const struct tcphdr *thdr = tcp_hdr(skb);
+ const struct net *net = sock_net(listen_sk);
+ bool thdr_ecn = thdr->ece && thdr->cwr;
+ bool ect_stat, ecn_okay;
+ u32 ecn_okay_dst;
+
+ if (!thdr_ecn)
+ return;
+
+ ect_stat = !INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield);
+ ecn_okay_dst = dst_feature(dst, DST_FEATURE_ECN_MASK);
+ ecn_okay = net->ipv4.sysctl_tcp_ecn || ecn_okay_dst;
+
+ if (((!ect_stat || thdr->res1) && ecn_okay) || tcp_ca_needs_ecn(listen_sk) ||
+ (ecn_okay_dst & DST_FEATURE_ECN_CA) ||
+ tcp_bpf_ca_needs_ecn((struct sock *)req))
+ inet_rsk(req)->ecn_ok = 1;
+}
+
+void mptcp_openreq_init(struct request_sock *req,
+ const struct tcp_options_received *rx_opt,
+ struct sk_buff *skb, const struct sock *sk)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+
+ req->rsk_rcv_wnd = 0;
+ tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
+ tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->seq + 1;
+ tcp_rsk(req)->snt_synack = 0;
+ tcp_rsk(req)->last_oow_ack_time = 0;
+ req->mss = rx_opt->mss_clamp;
+ req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
+ ireq->tstamp_ok = rx_opt->tstamp_ok;
+ ireq->sack_ok = rx_opt->sack_ok;
+ ireq->snd_wscale = rx_opt->snd_wscale;
+ ireq->wscale_ok = rx_opt->wscale_ok;
+ ireq->acked = 0;
+ ireq->ecn_ok = 0;
+ ireq->ir_rmt_port = tcp_hdr(skb)->source;
+ ireq->ir_num = ntohs(tcp_hdr(skb)->dest);
+ ireq->ir_mark = inet_request_mark(sk, skb);
+}
+
+void mptcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb)
+{
+ struct sock *msk = mptcp_subflow_ctx(sk)->conn;
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (TCP_SKB_CB(skb)->end_seq == tp->rcv_nxt)
+ return;
+
+ skb = skb_clone(skb, GFP_ATOMIC);
+ if (!skb)
+ return;
+
+ skb_dst_drop(skb);
+
+ tp->segs_in = 0;
+ tcp_segs_in(tp, skb);
+ __skb_pull(skb, tcp_hdrlen(skb));
+ sk_forced_mem_schedule(sk, skb->truesize);
+ skb_set_owner_r(skb, sk);
+
+ TCP_SKB_CB(skb)->seq++;
+ TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_SYN;
+
+ tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+
+ __skb_queue_tail(&msk->sk_receive_queue, skb);
+
+ tp->syn_data_acked = 1;
+
+ tp->bytes_received = skb->len;
+
+ if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
+ tcp_fin(sk);
+}
+
+struct sock *mptcp_fastopen_create_child(struct sock *sk,
+ struct sk_buff *skb,
+ struct request_sock *req)
+{
+ struct request_sock_queue *r_sock_queue = &inet_csk(sk)->icsk_accept_queue;
+ struct tcp_sock *tp;
+ struct sock *child_sock;
+ bool own_req;
+
+ child_sock = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
+ NULL, &own_req);
+ if (!child_sock)
+ return NULL;
+
+ spin_lock(&r_sock_queue->fastopenq.lock);
+ r_sock_queue->fastopenq.qlen++;
+ spin_unlock(&r_sock_queue->fastopenq.lock);
+
+ tp = tcp_sk(child_sock);
+
+ rcu_assign_pointer(tp->fastopen_rsk, req);
+ tcp_rsk(req)->tfo_listener = true;
+
+ tp->snd_wnd = ntohs(tcp_hdr(skb)->window);
+ tp->max_window = tp->snd_wnd;
+
+ inet_csk_reset_xmit_timer(child_sock, ICSK_TIME_RETRANS,
+ TCP_TIMEOUT_INIT, TCP_RTO_MAX);
+
+ refcount_set(&req->rsk_refcnt, 2);
+
+ tcp_init_transfer(child_sock, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, skb);
+
+
+ tp->rcv_nxt = TCP_SKB_CB(skb)->seq + 1;
+ //tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+ //tp->copied_seq = 4;//3
+
+ mptcp_fastopen_add_skb(child_sock, skb);
+
+ tcp_rsk(req)->rcv_nxt = tp->rcv_nxt;
+ tp->rcv_wup = tp->rcv_nxt;
+
+ return child_sock;
+}
+
+bool mptcp_fastopen_queue_check(struct sock *sk)
+{
+ struct fastopen_queue *fo_queue;
+ struct request_sock *req_sock;
+
+ fo_queue = &inet_csk(sk)->icsk_accept_queue.fastopenq;
+ if (fo_queue->max_qlen == 0)
+ return false;
+
+ if (fo_queue->qlen >= fo_queue->max_qlen) {
+
+ spin_lock(&fo_queue->lock);
+ req_sock = fo_queue->rskq_rst_head;
+ if (!req_sock || time_after(req_sock->rsk_timer.expires, jiffies)) {
+ spin_unlock(&fo_queue->lock);
+ return false;
+ }
+ fo_queue->rskq_rst_head = req_sock->dl_next;
+ fo_queue->qlen--;
+ spin_unlock(&fo_queue->lock);
+ reqsk_put(req_sock);
+ }
+ return true;
+}
+
+bool mptcp_fastopen_cookie_gen_cipher(struct request_sock *req,
+ struct sk_buff *syn,
+ const siphash_key_t *key,
+ struct tcp_fastopen_cookie *foc)
+{
+ if (req->rsk_ops->family == AF_INET) {
+ const struct iphdr *iph = ip_hdr(syn);
+
+ foc->val[0] = cpu_to_le64(siphash(&iph->saddr,
+ sizeof(iph->saddr) +
+ sizeof(iph->daddr),
+ key));
+ foc->len = TCP_FASTOPEN_COOKIE_SIZE;
+ return true;
+ }
+
+ return false;
+}
+
+
+void mptcp_fastopen_cookie_gen(struct sock *sk,
+ struct request_sock *req,
+ struct sk_buff *syn,
+ struct tcp_fastopen_cookie *foc)
+{
+ struct tcp_fastopen_context *ctx;
+
+ rcu_read_lock();
+ ctx = tcp_fastopen_get_ctx(sk);
+ if (ctx)
+ mptcp_fastopen_cookie_gen_cipher(req, syn, &ctx->key[0], foc);
+ rcu_read_unlock();
+}
+
+int mptcp_fastopen_cookie_gen_check(struct sock *sk,
+ struct request_sock *req,
+ struct sk_buff *syn,
+ struct tcp_fastopen_cookie *orig,
+ struct tcp_fastopen_cookie *valid_foc)
+{
+ struct tcp_fastopen_cookie mptcp_search_foc = { .len = -1 };
+ struct tcp_fastopen_cookie *mptcp_foc = valid_foc;
+ struct tcp_fastopen_context *mptcp_fo_ctx;
+ int i, ret = 0;
+
+ rcu_read_lock();
+ mptcp_fo_ctx = tcp_fastopen_get_ctx(sk);
+ if (!mptcp_fo_ctx)
+ goto out;
+ for (i = 0; i < tcp_fastopen_context_len(mptcp_fo_ctx); i++) {
+ mptcp_fastopen_cookie_gen_cipher(req, syn, &mptcp_fo_ctx->key[i], mptcp_foc);
+ if (tcp_fastopen_cookie_match(mptcp_foc, orig)) {
+ ret = i + 1;
+ goto out;
+ }
+ mptcp_foc = &mptcp_search_foc;
+ }
+out:
+ rcu_read_unlock();
+ return ret;
+}
+
+
+bool mptcp_fastopen_no_cookie(const struct sock *sk,
+ const struct dst_entry *dst,
+ int flag)
+{
+ return (sock_net(sk)->ipv4.sysctl_tcp_fastopen & flag) ||
+ tcp_sk(sk)->fastopen_no_cookie ||
+ (dst && dst_metric(dst, RTAX_FASTOPEN_NO_COOKIE));
+}
+
+struct sock *mptcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
+ struct request_sock *req,
+ struct tcp_fastopen_cookie *foc,
+ const struct dst_entry *dst)
+{
+ bool syn_data_status = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1;
+ struct tcp_fastopen_cookie valid_mptcp_foc = { .len = -1 };
+ struct sock *child_sock;
+ int ret = 0;
+
+
+ if ((syn_data_status || foc->len >= 0) &&
+ mptcp_fastopen_queue_check(sk)) {
+ foc->len = -1;
+ return NULL;
+ }
+
+ if (mptcp_fastopen_no_cookie(sk, dst, TFO_SERVER_COOKIE_NOT_REQD))
+ goto fastopen;
+
+ if (foc->len == 0) {
+ mptcp_fastopen_cookie_gen(sk, req, skb, &valid_mptcp_foc);
+ } else if (foc->len > 0) {
+ ret = mptcp_fastopen_cookie_gen_check(sk, req, skb, foc,
+ &valid_mptcp_foc);
+ if (!ret) {
+ __asm__ ("NOP");
+ } else {
+fastopen:
+ child_sock = mptcp_fastopen_create_child(sk, skb, req);
+ if (child_sock) {
+ if (ret == 2) {
+ valid_mptcp_foc.exp = foc->exp;
+ *foc = valid_mptcp_foc;
+ } else {
+ foc->len = -1;
+ }
+ return child_sock;
+ }
+ }
+ }
+ valid_mptcp_foc.exp = foc->exp;
+ *foc = valid_mptcp_foc;
+ return NULL;
+}
+
+int mptcp_conn_request(struct request_sock_ops *rsk_ops,
+ const struct tcp_request_sock_ops *af_ops,
+ struct sock *sk, struct sk_buff *skb)
+{
+ struct tcp_fastopen_cookie mptcp_foc = { .len = -1 };
+ struct tcp_options_received tmp_opt_rcvd;
+ __u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn;
+ struct tcp_sock *tp_sock = tcp_sk(sk);
+ struct sock *mptcp_fo_sk = NULL;
+ struct net *net = sock_net(sk);
+ struct request_sock *req_sock;
+ bool want_cookie = false;
+ struct dst_entry *dst;
+ struct flowi fl;
+
+ if (sk_acceptq_is_full(sk)) {
+ goto drop;
+ }
+
+ req_sock = inet_reqsk_alloc(rsk_ops, sk, !want_cookie);
+ if (!req_sock)
+ goto drop;
+
+ req_sock->syncookie = want_cookie;
+ tcp_rsk(req_sock)->af_specific = af_ops;
+ tcp_rsk(req_sock)->ts_off = 0;
+ tcp_rsk(req_sock)->is_mptcp = 1;
+
+ tcp_clear_options(&tmp_opt_rcvd);
+ tmp_opt_rcvd.mss_clamp = af_ops->mss_clamp;
+ tmp_opt_rcvd.user_mss = tp_sock->rx_opt.user_mss;
+ tcp_parse_options(sock_net(sk), skb, &tmp_opt_rcvd, 0,
+ want_cookie ? NULL : &mptcp_foc);
+
+ if (want_cookie && !tmp_opt_rcvd.saw_tstamp)
+ tcp_clear_options(&tmp_opt_rcvd);
+
+ if (IS_ENABLED(CONFIG_SMC) && want_cookie)
+ tmp_opt_rcvd.smc_ok = 0;
+
+ tmp_opt_rcvd.tstamp_ok = tmp_opt_rcvd.saw_tstamp;
+ mptcp_openreq_init(req_sock, &tmp_opt_rcvd, skb, sk);
+ inet_rsk(req_sock)->no_srccheck = inet_sk(sk)->transparent;
+
+ inet_rsk(req_sock)->ir_iif = inet_request_bound_dev_if(sk, skb);
+
+ dst = af_ops->route_req(sk, skb, &fl, req_sock);
+ if (!dst)
+ goto drop_and_free;
+
+ if (tmp_opt_rcvd.tstamp_ok)
+ tcp_rsk(req_sock)->ts_off = af_ops->init_ts_off(net, skb);
+
+ if (!want_cookie && !isn) {
+ if (!net->ipv4.sysctl_tcp_syncookies &&
+ (net->ipv4.sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
+ (net->ipv4.sysctl_max_syn_backlog >> 2)) &&
+ !tcp_peer_is_proven(req_sock, dst)) {
+ goto drop_and_release;
+ }
+
+ isn = af_ops->init_seq(skb);
+ }
+
+ mptcp_ecn_create_request(req_sock, skb, sk, dst);
+
+ if (want_cookie) {
+ isn = cookie_init_sequence(af_ops, sk, skb, &req_sock->mss);
+ if (!tmp_opt_rcvd.tstamp_ok)
+ inet_rsk(req_sock)->ecn_ok = 0;
+ }
+
+ tcp_rsk(req_sock)->snt_isn = isn;
+ tcp_rsk(req_sock)->txhash = net_tx_rndhash();
+ tcp_rsk(req_sock)->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;
+
+ tcp_openreq_init_rwin(req_sock, sk, dst);
+ sk_rx_queue_set(req_to_sk(req_sock), skb);
+ if (!want_cookie) {
+ mptcp_reqsk_record_syn(sk, req_sock, skb);
+ mptcp_fo_sk = mptcp_try_fastopen(sk, skb, req_sock, &mptcp_foc, dst);
+ }
+ if (mptcp_fo_sk) {
+ af_ops->send_synack(mptcp_fo_sk, dst, &fl, req_sock,
+ &mptcp_foc, TCP_SYNACK_FASTOPEN, skb);
+ if (!inet_csk_reqsk_queue_add(sk, req_sock, mptcp_fo_sk)) {
+ reqsk_fastopen_remove(mptcp_fo_sk, req_sock, false);
+ bh_unlock_sock(mptcp_fo_sk);
+ sock_put(mptcp_fo_sk);
+ goto drop_and_free;
+ }
+ sk->sk_data_ready(sk);
+ bh_unlock_sock(mptcp_fo_sk);
+ sock_put(mptcp_fo_sk);
+
+
+ } else {
+ tcp_rsk(req_sock)->tfo_listener = false;
+ if (!want_cookie) {
+ req_sock->timeout = tcp_timeout_init((struct sock *)req_sock);
+ inet_csk_reqsk_queue_hash_add(sk, req_sock, req_sock->timeout);
+ }
+ af_ops->send_synack(sk, dst, &fl, req_sock, &mptcp_foc,
+ !want_cookie ? TCP_SYNACK_NORMAL :
+ TCP_SYNACK_COOKIE,
+ skb);
+ if (want_cookie) {
+ reqsk_free(req_sock);
+ return 0;
+ }
+ }
+ reqsk_put(req_sock);
+ return 0;
+
+drop_and_release:
+ dst_release(dst);
+drop_and_free:
+ __reqsk_free(req_sock);
+drop:
+ tcp_listendrop(sk);
+ return 0;
+}
diff --git a/net/mptcp/mptcp_fastopen.h b/net/mptcp/mptcp_fastopen.h
new file mode 100644
index 000000000000..c050195c60a7
--- /dev/null
+++ b/net/mptcp/mptcp_fastopen.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * MPTCP Fast Open Mechanism. Copyright (c) 2021-2022, Dmytro SHYTYI.
+ */
+
+#ifndef __MPTCP_FASTOPEN_H
+#define __MPTCP_FASTOPEN_H
+
+#include <uapi/linux/mptcp.h>
+#include <net/mptcp.h>
+#include <net/sock.h>
+#include "protocol.h"
+
+int mptcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
+ size_t len, struct mptcp_sock *msk,
+ size_t *copied);
+
+void mptcp_reqsk_record_syn(const struct sock *sk,
+ struct request_sock *req,
+ const struct sk_buff *skb);
+
+void mptcp_ecn_create_request(struct request_sock *req,
+ const struct sk_buff *skb,
+ const struct sock *listen_sk,
+ const struct dst_entry *dst);
+
+void mptcp_openreq_init(struct request_sock *req,
+ const struct tcp_options_received *rx_opt,
+ struct sk_buff *skb, const struct sock *sk);
+
+void mptcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb);
+
+struct sock *mptcp_fastopen_create_child(struct sock *sk,
+ struct sk_buff *skb,
+ struct request_sock *req);
+
+bool mptcp_fastopen_queue_check(struct sock *sk);
+
+bool mptcp_fastopen_cookie_gen_cipher(struct request_sock *req,
+ struct sk_buff *syn,
+ const siphash_key_t *key,
+ struct tcp_fastopen_cookie *foc);
+
+void mptcp_fastopen_cookie_gen(struct sock *sk,
+ struct request_sock *req,
+ struct sk_buff *syn,
+ struct tcp_fastopen_cookie *foc);
+
+int mptcp_fastopen_cookie_gen_check(struct sock *sk,
+ struct request_sock *req,
+ struct sk_buff *syn,
+ struct tcp_fastopen_cookie *orig,
+ struct tcp_fastopen_cookie *valid_foc);
+
+bool mptcp_fastopen_no_cookie(const struct sock *sk,
+ const struct dst_entry *dst,
+ int flag);
+
+struct sock *mptcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
+ struct request_sock *req,
+ struct tcp_fastopen_cookie *foc,
+ const struct dst_entry *dst);
+
+int mptcp_conn_request(struct request_sock_ops *rsk_ops,
+ const struct tcp_request_sock_ops *af_ops,
+ struct sock *sk, struct sk_buff *skb);
+
+#endif /* __MPTCP_FASTOPEN_H */
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index be3b918a6d15..1ce965ee71d2 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -887,16 +887,19 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
}
bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
- struct mptcp_out_options *opts)
+ struct mptcp_out_options *opts, u16 *tcp_options)
{
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
+ struct inet_request_sock *ireq = inet_rsk(req);
+#define OPTION_TS BIT(1)
+ *tcp_options ^= OPTION_TS;
if (subflow_req->mp_capable) {
opts->suboptions = OPTION_MPTCP_MPC_SYNACK;
opts->sndr_key = subflow_req->local_key;
opts->csum_reqd = subflow_req->csum_reqd;
opts->allow_join_id0 = subflow_req->allow_join_id0;
- *size = TCPOLEN_MPTCP_MPC_SYNACK;
+ *size = TCPOLEN_MPTCP_MPC_SYNACK - TCPOLEN_TSTAMP_ALIGNED + TCPOLEN_SACKPERM_ALIGNED;
pr_debug("subflow_req=%p, local_key=%llu",
subflow_req, subflow_req->local_key);
return true;
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index d6aef4b13b8a..64a2635405c4 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -25,6 +25,7 @@
#include <asm/ioctls.h>
#include "protocol.h"
#include "mib.h"
+#include "mptcp_fastopen.h"
#define CREATE_TRACE_POINTS
#include <trace/events/mptcp.h>
@@ -1690,9 +1691,9 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
int ret = 0;
long timeo;
- /* we don't support FASTOPEN yet */
+ /* we don't fully support FASTOPEN yet */
if (msg->msg_flags & MSG_FASTOPEN)
- return -EOPNOTSUPP;
+ mptcp_sendmsg_fastopen(sk, msg, len, msk, &copied);
/* silently ignore everything else */
msg->msg_flags &= MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL;
@@ -2681,6 +2682,7 @@ void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
case TCP_SYN_SENT:
tcp_disconnect(ssk, O_NONBLOCK);
break;
+ case TCP_ESTABLISHED:
default:
if (__mptcp_check_fallback(mptcp_sk(sk))) {
pr_debug("Fallback");
@@ -3476,7 +3478,7 @@ static void mptcp_subflow_early_fallback(struct mptcp_sock *msk,
__mptcp_do_fallback(msk);
}
-static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
+int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
int addr_len, int flags)
{
struct mptcp_sock *msk = mptcp_sk(sock->sk);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 8739794166d8..6b8784a35244 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -891,6 +891,9 @@ unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk);
unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
+int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
+ int addr_len, int flags);
+
/* called under PM lock */
static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
{
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 423d3826ca1e..e1ae1ef224cf 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -560,6 +560,8 @@ static bool mptcp_supported_sockopt(int level, int optname)
case TCP_TX_DELAY:
case TCP_INQ:
return true;
+ case TCP_FASTOPEN:
+ return true;
}
/* TCP_MD5SIG, TCP_MD5SIG_EXT are not supported, MD5 is not compatible with MPTCP */
@@ -768,6 +770,43 @@ static int mptcp_setsockopt_sol_tcp_defer(struct mptcp_sock *msk, sockptr_t optv
return tcp_setsockopt(listener->sk, SOL_TCP, TCP_DEFER_ACCEPT, optval, optlen);
}
+static int mptcp_setsockopt_sol_tcp_fastopen(struct mptcp_sock *msk, sockptr_t optval,
+ unsigned int optlen)
+{
+ struct mptcp_subflow_context *subflow;
+ struct sock *sk = (struct sock *)msk;
+ struct net *net = sock_net(sk);
+ int val;
+ int ret;
+
+ ret = 0;
+
+ if (copy_from_sockptr(&val, optval, sizeof(val)))
+ return -EFAULT;
+
+ lock_sock(sk);
+
+ mptcp_for_each_subflow(msk, subflow) {
+ struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+
+ lock_sock(ssk);
+
+ if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
+ TCPF_LISTEN))) {
+ tcp_fastopen_init_key_once(net);
+ fastopen_queue_tune(sk, val);
+ } else {
+ ret = -EINVAL;
+ }
+
+ release_sock(ssk);
+ }
+
+ release_sock(sk);
+
+ return ret;
+}
+
static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
sockptr_t optval, unsigned int optlen)
{
@@ -796,6 +835,8 @@ static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
return mptcp_setsockopt_sol_tcp_nodelay(msk, optval, optlen);
case TCP_DEFER_ACCEPT:
return mptcp_setsockopt_sol_tcp_defer(msk, optval, optlen);
+ case TCP_FASTOPEN:
+ return mptcp_setsockopt_sol_tcp_fastopen(msk, optval, optlen);
}
return -EOPNOTSUPP;
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 8841e8cd9ad8..9fa71b67fd5a 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -22,6 +22,7 @@
#endif
#include <net/mptcp.h>
#include <uapi/linux/mptcp.h>
+#include "mptcp_fastopen.h"
#include "protocol.h"
#include "mib.h"
@@ -542,9 +543,9 @@ static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb)
if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
goto drop;
- return tcp_conn_request(&mptcp_subflow_request_sock_ops,
- &subflow_request_sock_ipv4_ops,
- sk, skb);
+ return mptcp_conn_request(&mptcp_subflow_request_sock_ops,
+ &subflow_request_sock_ipv4_ops,
+ sk, skb);
drop:
tcp_listendrop(sk);
return 0;
--
2.25.1
next reply other threads:[~2022-08-01 2:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-01 2:46 Dmytro SHYTYI [this message]
2022-08-01 2:57 ` mptcp: Fast Open Mechanism: Build Failure MPTCP CI
2022-08-01 2:59 ` mptcp: Fast Open Mechanism: Tests Results MPTCP CI
2022-08-03 0:32 ` [RFC PATCH mptcp-next v4] mptcp: Fast Open Mechanism Mat Martineau
2022-08-03 7:36 ` Dmytro SHYTYI
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