From 5b7ed0892f2af4e60b9a8d2c71c77774512a6cb9 Mon Sep 17 00:00:00 2001 From: Yuchung Cheng Date: Sun, 11 May 2014 20:22:09 -0700 Subject: 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 Signed-off-by: Daniel Lee Signed-off-by: Jerry Chu Signed-off-by: Eric Dumazet Acked-by: Neal Cardwell Signed-off-by: David S. Miller --- include/net/tcp.h | 10 ++- net/ipv4/tcp_fastopen.c | 190 ++++++++++++++++++++++++++++++++++++++++++++++++ net/ipv4/tcp_ipv4.c | 185 +--------------------------------------------- 3 files changed, 200 insertions(+), 185 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 3c9418456640..012236838583 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -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 diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index f195d9316e55..0606c91d9d0b 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -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); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index ad166dcc278f..032fcaee164a 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -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; -- cgit v1.2.3