tcp: move fastopen functions to tcp_fastopen.c
authorYuchung Cheng <ycheng@google.com>
Mon, 12 May 2014 03:22:09 +0000 (20:22 -0700)
committerDavid S. Miller <davem@davemloft.net>
Tue, 13 May 2014 21:53:02 +0000 (17:53 -0400)
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>
include/net/tcp.h
net/ipv4/tcp_fastopen.c
net/ipv4/tcp_ipv4.c

index 3c94184566408188a35517af671c2d6511a64ecf..01223683858314edf56a3a4a31cec010f95e00b6 100644 (file)
@@ -1329,8 +1329,14 @@ void tcp_free_fastopen_req(struct tcp_sock *tp);
 
 extern struct tcp_fastopen_context __rcu *tcp_fastopen_ctx;
 int tcp_fastopen_reset_cipher(void *key, unsigned int len);
-void tcp_fastopen_cookie_gen(__be32 src, __be32 dst,
-                            struct tcp_fastopen_cookie *foc);
+int tcp_fastopen_create_child(struct sock *sk,
+                             struct sk_buff *skb,
+                             struct sk_buff *skb_synack,
+                             struct request_sock *req);
+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);
 void tcp_fastopen_init_key_once(bool publish);
 #define TCP_FASTOPEN_KEY_LENGTH 16
 
index f195d9316e55d3d7ef6dc5285606ea9de0f52a51..0606c91d9d0b344ca833c6b0d53c021b9a49df57 100644 (file)
@@ -94,3 +94,193 @@ void tcp_fastopen_cookie_gen(__be32 src, __be32 dst,
        }
        rcu_read_unlock();
 }
+
+int tcp_fastopen_create_child(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;
+}
+EXPORT_SYMBOL(tcp_fastopen_create_child);
+
+static bool tcp_fastopen_queue_check(struct sock *sk)
+{
+       struct fastopen_queue *fastopenq;
+
+       /* 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.
+        */
+       fastopenq = inet_csk(sk)->icsk_accept_queue.fastopenq;
+       if (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);
+                       return false;
+               }
+               fastopenq->rskq_rst_head = req1->dl_next;
+               fastopenq->qlen--;
+               spin_unlock(&fastopenq->lock);
+               reqsk_free(req1);
+       }
+       return true;
+}
+
+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;
+
+       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;
+       }
+       /* A FO option is present; bump the counter. */
+       NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENPASSIVE);
+
+       if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) == 0 ||
+           !tcp_fastopen_queue_check(sk))
+               return false;
+
+       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;
+}
+EXPORT_SYMBOL(tcp_fastopen_check);
index ad166dcc278fe46f2e5863eb90cf8b12b878a404..032fcaee164a4bc93ad042c6616a10ddd9a0248b 100644 (file)
@@ -1260,187 +1260,6 @@ static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
 };
 #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 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
                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;