tcp: move fastopen functions to tcp_fastopen.c
Move common TFO functions that will be used by both v4 and v6
to tcp_fastopen.c. Create a helper tcp_fastopen_queue_check().
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Daniel Lee <longinus00@gmail.com>
Signed-off-by: Jerry Chu <hkchu@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index ad166dc..032fcae 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1260,187 +1260,6 @@
};
#endif
-static bool tcp_fastopen_check(struct sock *sk, struct sk_buff *skb,
- struct request_sock *req,
- struct tcp_fastopen_cookie *foc,
- struct tcp_fastopen_cookie *valid_foc)
-{
- bool skip_cookie = false;
- struct fastopen_queue *fastopenq;
-
- if (likely(!fastopen_cookie_present(foc))) {
- /* See include/net/tcp.h for the meaning of these knobs */
- if ((sysctl_tcp_fastopen & TFO_SERVER_ALWAYS) ||
- ((sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD) &&
- (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1)))
- skip_cookie = true; /* no cookie to validate */
- else
- return false;
- }
- fastopenq = inet_csk(sk)->icsk_accept_queue.fastopenq;
- /* A FO option is present; bump the counter. */
- NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVE);
-
- /* Make sure the listener has enabled fastopen, and we don't
- * exceed the max # of pending TFO requests allowed before trying
- * to validating the cookie in order to avoid burning CPU cycles
- * unnecessarily.
- *
- * XXX (TFO) - The implication of checking the max_qlen before
- * processing a cookie request is that clients can't differentiate
- * between qlen overflow causing Fast Open to be disabled
- * temporarily vs a server not supporting Fast Open at all.
- */
- if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) == 0 ||
- fastopenq == NULL || fastopenq->max_qlen == 0)
- return false;
-
- if (fastopenq->qlen >= fastopenq->max_qlen) {
- struct request_sock *req1;
- spin_lock(&fastopenq->lock);
- req1 = fastopenq->rskq_rst_head;
- if ((req1 == NULL) || time_after(req1->expires, jiffies)) {
- spin_unlock(&fastopenq->lock);
- NET_INC_STATS_BH(sock_net(sk),
- LINUX_MIB_TCPFASTOPENLISTENOVERFLOW);
- /* Avoid bumping LINUX_MIB_TCPFASTOPENPASSIVEFAIL*/
- foc->len = -1;
- return false;
- }
- fastopenq->rskq_rst_head = req1->dl_next;
- fastopenq->qlen--;
- spin_unlock(&fastopenq->lock);
- reqsk_free(req1);
- }
- if (skip_cookie) {
- tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
- return true;
- }
-
- if (foc->len == TCP_FASTOPEN_COOKIE_SIZE) {
- if ((sysctl_tcp_fastopen & TFO_SERVER_COOKIE_NOT_CHKED) == 0) {
- tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr,
- ip_hdr(skb)->daddr, valid_foc);
- if ((valid_foc->len != TCP_FASTOPEN_COOKIE_SIZE) ||
- memcmp(&foc->val[0], &valid_foc->val[0],
- TCP_FASTOPEN_COOKIE_SIZE) != 0)
- return false;
- valid_foc->len = -1;
- }
- /* Acknowledge the data received from the peer. */
- tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
- return true;
- } else if (foc->len == 0) { /* Client requesting a cookie */
- tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr,
- ip_hdr(skb)->daddr, valid_foc);
- NET_INC_STATS_BH(sock_net(sk),
- LINUX_MIB_TCPFASTOPENCOOKIEREQD);
- } else {
- /* Client sent a cookie with wrong size. Treat it
- * the same as invalid and return a valid one.
- */
- tcp_fastopen_cookie_gen(ip_hdr(skb)->saddr,
- ip_hdr(skb)->daddr, valid_foc);
- }
- return false;
-}
-
-static int tcp_v4_conn_req_fastopen(struct sock *sk,
- struct sk_buff *skb,
- struct sk_buff *skb_synack,
- struct request_sock *req)
-{
- struct tcp_sock *tp = tcp_sk(sk);
- struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
- const struct inet_request_sock *ireq = inet_rsk(req);
- struct sock *child;
- int err;
-
- req->num_retrans = 0;
- req->num_timeout = 0;
- req->sk = NULL;
-
- child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
- if (child == NULL) {
- NET_INC_STATS_BH(sock_net(sk),
- LINUX_MIB_TCPFASTOPENPASSIVEFAIL);
- kfree_skb(skb_synack);
- return -1;
- }
- err = ip_build_and_send_pkt(skb_synack, sk, ireq->ir_loc_addr,
- ireq->ir_rmt_addr, ireq->opt);
- err = net_xmit_eval(err);
- if (!err)
- tcp_rsk(req)->snt_synack = tcp_time_stamp;
- /* XXX (TFO) - is it ok to ignore error and continue? */
-
- spin_lock(&queue->fastopenq->lock);
- queue->fastopenq->qlen++;
- spin_unlock(&queue->fastopenq->lock);
-
- /* Initialize the child socket. Have to fix some values to take
- * into account the child is a Fast Open socket and is created
- * only out of the bits carried in the SYN packet.
- */
- tp = tcp_sk(child);
-
- tp->fastopen_rsk = req;
- /* Do a hold on the listner sk so that if the listener is being
- * closed, the child that has been accepted can live on and still
- * access listen_lock.
- */
- sock_hold(sk);
- tcp_rsk(req)->listener = sk;
-
- /* RFC1323: The window in SYN & SYN/ACK segments is never
- * scaled. So correct it appropriately.
- */
- tp->snd_wnd = ntohs(tcp_hdr(skb)->window);
-
- /* Activate the retrans timer so that SYNACK can be retransmitted.
- * The request socket is not added to the SYN table of the parent
- * because it's been added to the accept queue directly.
- */
- inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS,
- TCP_TIMEOUT_INIT, TCP_RTO_MAX);
-
- /* Add the child socket directly into the accept queue */
- inet_csk_reqsk_queue_add(sk, req, child);
-
- /* Now finish processing the fastopen child socket. */
- inet_csk(child)->icsk_af_ops->rebuild_header(child);
- tcp_init_congestion_control(child);
- tcp_mtup_init(child);
- tcp_init_metrics(child);
- tcp_init_buffer_space(child);
-
- /* Queue the data carried in the SYN packet. We need to first
- * bump skb's refcnt because the caller will attempt to free it.
- *
- * XXX (TFO) - we honor a zero-payload TFO request for now.
- * (Any reason not to?)
- */
- if (TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq + 1) {
- /* Don't queue the skb if there is no payload in SYN.
- * XXX (TFO) - How about SYN+FIN?
- */
- tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
- } else {
- skb = skb_get(skb);
- skb_dst_drop(skb);
- __skb_pull(skb, tcp_hdr(skb)->doff * 4);
- skb_set_owner_r(skb, child);
- __skb_queue_tail(&child->sk_receive_queue, skb);
- tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
- tp->syn_data_acked = 1;
- }
- sk->sk_data_ready(sk);
- bh_unlock_sock(child);
- sock_put(child);
- WARN_ON(req->sk == NULL);
- return 0;
-}
-
int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
{
struct tcp_options_received tmp_opt;
@@ -1599,8 +1418,8 @@
if (fastopen_cookie_present(&foc) && foc.len != 0)
NET_INC_STATS_BH(sock_net(sk),
LINUX_MIB_TCPFASTOPENPASSIVEFAIL);
- } else if (tcp_v4_conn_req_fastopen(sk, skb, skb_synack, req))
- goto drop_and_free;
+ } else if (tcp_fastopen_create_child(sk, skb, skb_synack, req))
+ goto drop_and_release;
return 0;