diff options
Diffstat (limited to 'include/net/request_sock.h')
| -rw-r--r-- | include/net/request_sock.h | 49 |
1 files changed, 36 insertions, 13 deletions
diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 4c0766e201e..b01d8dd9ee7 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -106,6 +106,34 @@ struct listen_sock { struct request_sock *syn_table[0]; }; +/* + * For a TCP Fast Open listener - + * lock - protects the access to all the reqsk, which is co-owned by + * the listener and the child socket. + * qlen - pending TFO requests (still in TCP_SYN_RECV). + * max_qlen - max TFO reqs allowed before TFO is disabled. + * + * XXX (TFO) - ideally these fields can be made as part of "listen_sock" + * structure above. But there is some implementation difficulty due to + * listen_sock being part of request_sock_queue hence will be freed when + * a listener is stopped. But TFO related fields may continue to be + * accessed even after a listener is closed, until its sk_refcnt drops + * to 0 implying no more outstanding TFO reqs. One solution is to keep + * listen_opt around until sk_refcnt drops to 0. But there is some other + * complexity that needs to be resolved. E.g., a listener can be disabled + * temporarily through shutdown()->tcp_disconnect(), and re-enabled later. + */ +struct fastopen_queue { + struct request_sock *rskq_rst_head; /* Keep track of past TFO */ + struct request_sock *rskq_rst_tail; /* requests that caused RST. + * This is part of the defense + * against spoofing attack. + */ + spinlock_t lock; + int qlen; /* # of pending (TCP_SYN_RECV) reqs */ + int max_qlen; /* != 0 iff TFO is currently enabled */ +}; + /** struct request_sock_queue - queue of request_socks * * @rskq_accept_head - FIFO head of established children @@ -129,6 +157,12 @@ struct request_sock_queue { u8 rskq_defer_accept; /* 3 bytes hole, try to pack */ struct listen_sock *listen_opt; + struct fastopen_queue *fastopenq; /* This is non-NULL iff TFO has been + * enabled on this listener. Check + * max_qlen != 0 in fastopen_queue + * to determine if TFO is enabled + * right at this moment. + */ }; extern int reqsk_queue_alloc(struct request_sock_queue *queue, @@ -136,6 +170,8 @@ extern int reqsk_queue_alloc(struct request_sock_queue *queue, extern void __reqsk_queue_destroy(struct request_sock_queue *queue); extern void reqsk_queue_destroy(struct request_sock_queue *queue); +extern void reqsk_fastopen_remove(struct sock *sk, + struct request_sock *req, bool reset); static inline struct request_sock * reqsk_queue_yank_acceptq(struct request_sock_queue *queue) @@ -190,19 +226,6 @@ static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue return req; } -static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue, - struct sock *parent) -{ - struct request_sock *req = reqsk_queue_remove(queue); - struct sock *child = req->sk; - - WARN_ON(child == NULL); - - sk_acceptq_removed(parent); - __reqsk_free(req); - return child; -} - static inline int reqsk_queue_removed(struct request_sock_queue *queue, struct request_sock *req) { |