diff options
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 402 |
1 files changed, 98 insertions, 304 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index f730935b824a..5010f0c5a56e 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -505,25 +505,6 @@ static __inline__ int tcp_sk_listen_hashfn(struct sock *sk) #else # define TCP_TW_RECYCLE_TICK (12+2-TCP_TW_RECYCLE_SLOTS_LOG) #endif - -#define BICTCP_BETA_SCALE 1024 /* Scale factor beta calculation - * max_cwnd = snd_cwnd * beta - */ -#define BICTCP_MAX_INCREMENT 32 /* - * Limit on the amount of - * increment allowed during - * binary search. - */ -#define BICTCP_FUNC_OF_MIN_INCR 11 /* - * log(B/Smin)/log(B/(B-1))+1, - * Smin:min increment - * B:log factor - */ -#define BICTCP_B 4 /* - * In binary search, - * go to point (max+min)/N - */ - /* * TCP option */ @@ -596,16 +577,7 @@ extern int sysctl_tcp_adv_win_scale; extern int sysctl_tcp_tw_reuse; extern int sysctl_tcp_frto; extern int sysctl_tcp_low_latency; -extern int sysctl_tcp_westwood; -extern int sysctl_tcp_vegas_cong_avoid; -extern int sysctl_tcp_vegas_alpha; -extern int sysctl_tcp_vegas_beta; -extern int sysctl_tcp_vegas_gamma; extern int sysctl_tcp_nometrics_save; -extern int sysctl_tcp_bic; -extern int sysctl_tcp_bic_fast_convergence; -extern int sysctl_tcp_bic_low_window; -extern int sysctl_tcp_bic_beta; extern int sysctl_tcp_moderate_rcvbuf; extern int sysctl_tcp_tso_win_divisor; @@ -749,11 +721,16 @@ static inline int tcp_ack_scheduled(struct tcp_sock *tp) return tp->ack.pending&TCP_ACK_SCHED; } -static __inline__ void tcp_dec_quickack_mode(struct tcp_sock *tp) +static __inline__ void tcp_dec_quickack_mode(struct tcp_sock *tp, unsigned int pkts) { - if (tp->ack.quick && --tp->ack.quick == 0) { - /* Leaving quickack mode we deflate ATO. */ - tp->ack.ato = TCP_ATO_MIN; + if (tp->ack.quick) { + if (pkts >= tp->ack.quick) { + tp->ack.quick = 0; + + /* Leaving quickack mode we deflate ATO. */ + tp->ack.ato = TCP_ATO_MIN; + } else + tp->ack.quick -= pkts; } } @@ -871,7 +848,9 @@ extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, /* tcp_output.c */ -extern int tcp_write_xmit(struct sock *, int nonagle); +extern void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp, + unsigned int cur_mss, int nonagle); +extern int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp); extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); extern void tcp_xmit_retransmit_queue(struct sock *); extern void tcp_simple_retransmit(struct sock *); @@ -881,12 +860,16 @@ extern void tcp_send_probe0(struct sock *); extern void tcp_send_partial(struct sock *); extern int tcp_write_wakeup(struct sock *); extern void tcp_send_fin(struct sock *sk); -extern void tcp_send_active_reset(struct sock *sk, int priority); +extern void tcp_send_active_reset(struct sock *sk, + unsigned int __nocast priority); extern int tcp_send_synack(struct sock *); -extern void tcp_push_one(struct sock *, unsigned mss_now); +extern void tcp_push_one(struct sock *, unsigned int mss_now); extern void tcp_send_ack(struct sock *sk); extern void tcp_send_delayed_ack(struct sock *sk); +/* tcp_input.c */ +extern void tcp_cwnd_application_limited(struct sock *sk); + /* tcp_timer.c */ extern void tcp_init_xmit_timers(struct sock *); extern void tcp_clear_xmit_timers(struct sock *); @@ -986,7 +969,7 @@ static inline void tcp_reset_xmit_timer(struct sock *sk, int what, unsigned long static inline void tcp_initialize_rcv_mss(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); - unsigned int hint = min(tp->advmss, tp->mss_cache_std); + unsigned int hint = min_t(unsigned int, tp->advmss, tp->mss_cache); hint = min(hint, tp->rcv_wnd/2); hint = min(hint, TCP_MIN_RCVMSS); @@ -1009,7 +992,7 @@ static __inline__ void tcp_fast_path_on(struct tcp_sock *tp) static inline void tcp_fast_path_check(struct sock *sk, struct tcp_sock *tp) { - if (skb_queue_len(&tp->out_of_order_queue) == 0 && + if (skb_queue_empty(&tp->out_of_order_queue) && tp->rcv_wnd && atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && !tp->urg_data) @@ -1136,6 +1119,82 @@ static inline void tcp_packets_out_dec(struct tcp_sock *tp, tp->packets_out -= tcp_skb_pcount(skb); } +/* Events passed to congestion control interface */ +enum tcp_ca_event { + CA_EVENT_TX_START, /* first transmit when no packets in flight */ + CA_EVENT_CWND_RESTART, /* congestion window restart */ + CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ + CA_EVENT_FRTO, /* fast recovery timeout */ + CA_EVENT_LOSS, /* loss timeout */ + CA_EVENT_FAST_ACK, /* in sequence ack */ + CA_EVENT_SLOW_ACK, /* other ack */ +}; + +/* + * Interface for adding new TCP congestion control handlers + */ +#define TCP_CA_NAME_MAX 16 +struct tcp_congestion_ops { + struct list_head list; + + /* initialize private data (optional) */ + void (*init)(struct tcp_sock *tp); + /* cleanup private data (optional) */ + void (*release)(struct tcp_sock *tp); + + /* return slow start threshold (required) */ + u32 (*ssthresh)(struct tcp_sock *tp); + /* lower bound for congestion window (optional) */ + u32 (*min_cwnd)(struct tcp_sock *tp); + /* do new cwnd calculation (required) */ + void (*cong_avoid)(struct tcp_sock *tp, u32 ack, + u32 rtt, u32 in_flight, int good_ack); + /* round trip time sample per acked packet (optional) */ + void (*rtt_sample)(struct tcp_sock *tp, u32 usrtt); + /* call before changing ca_state (optional) */ + void (*set_state)(struct tcp_sock *tp, u8 new_state); + /* call when cwnd event occurs (optional) */ + void (*cwnd_event)(struct tcp_sock *tp, enum tcp_ca_event ev); + /* new value of cwnd after loss (optional) */ + u32 (*undo_cwnd)(struct tcp_sock *tp); + /* hook for packet ack accounting (optional) */ + void (*pkts_acked)(struct tcp_sock *tp, u32 num_acked); + /* get info for tcp_diag (optional) */ + void (*get_info)(struct tcp_sock *tp, u32 ext, struct sk_buff *skb); + + char name[TCP_CA_NAME_MAX]; + struct module *owner; +}; + +extern int tcp_register_congestion_control(struct tcp_congestion_ops *type); +extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); + +extern void tcp_init_congestion_control(struct tcp_sock *tp); +extern void tcp_cleanup_congestion_control(struct tcp_sock *tp); +extern int tcp_set_default_congestion_control(const char *name); +extern void tcp_get_default_congestion_control(char *name); +extern int tcp_set_congestion_control(struct tcp_sock *tp, const char *name); + +extern struct tcp_congestion_ops tcp_init_congestion_ops; +extern u32 tcp_reno_ssthresh(struct tcp_sock *tp); +extern void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack, + u32 rtt, u32 in_flight, int flag); +extern u32 tcp_reno_min_cwnd(struct tcp_sock *tp); +extern struct tcp_congestion_ops tcp_reno; + +static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state) +{ + if (tp->ca_ops->set_state) + tp->ca_ops->set_state(tp, ca_state); + tp->ca_state = ca_state; +} + +static inline void tcp_ca_event(struct tcp_sock *tp, enum tcp_ca_event event) +{ + if (tp->ca_ops->cwnd_event) + tp->ca_ops->cwnd_event(tp, event); +} + /* This determines how many packets are "in the network" to the best * of our knowledge. In many cases it is conservative, but where * detailed information is available from the receiver (via SACK @@ -1155,91 +1214,6 @@ static __inline__ unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) return (tp->packets_out - tp->left_out + tp->retrans_out); } -/* - * Which congestion algorithim is in use on the connection. - */ -#define tcp_is_vegas(__tp) ((__tp)->adv_cong == TCP_VEGAS) -#define tcp_is_westwood(__tp) ((__tp)->adv_cong == TCP_WESTWOOD) -#define tcp_is_bic(__tp) ((__tp)->adv_cong == TCP_BIC) - -/* Recalculate snd_ssthresh, we want to set it to: - * - * Reno: - * one half the current congestion window, but no - * less than two segments - * - * BIC: - * behave like Reno until low_window is reached, - * then increase congestion window slowly - */ -static inline __u32 tcp_recalc_ssthresh(struct tcp_sock *tp) -{ - if (tcp_is_bic(tp)) { - if (sysctl_tcp_bic_fast_convergence && - tp->snd_cwnd < tp->bictcp.last_max_cwnd) - tp->bictcp.last_max_cwnd = (tp->snd_cwnd * - (BICTCP_BETA_SCALE - + sysctl_tcp_bic_beta)) - / (2 * BICTCP_BETA_SCALE); - else - tp->bictcp.last_max_cwnd = tp->snd_cwnd; - - if (tp->snd_cwnd > sysctl_tcp_bic_low_window) - return max((tp->snd_cwnd * sysctl_tcp_bic_beta) - / BICTCP_BETA_SCALE, 2U); - } - - return max(tp->snd_cwnd >> 1U, 2U); -} - -/* Stop taking Vegas samples for now. */ -#define tcp_vegas_disable(__tp) ((__tp)->vegas.doing_vegas_now = 0) - -static inline void tcp_vegas_enable(struct tcp_sock *tp) -{ - /* There are several situations when we must "re-start" Vegas: - * - * o when a connection is established - * o after an RTO - * o after fast recovery - * o when we send a packet and there is no outstanding - * unacknowledged data (restarting an idle connection) - * - * In these circumstances we cannot do a Vegas calculation at the - * end of the first RTT, because any calculation we do is using - * stale info -- both the saved cwnd and congestion feedback are - * stale. - * - * Instead we must wait until the completion of an RTT during - * which we actually receive ACKs. - */ - - /* Begin taking Vegas samples next time we send something. */ - tp->vegas.doing_vegas_now = 1; - - /* Set the beginning of the next send window. */ - tp->vegas.beg_snd_nxt = tp->snd_nxt; - - tp->vegas.cntRTT = 0; - tp->vegas.minRTT = 0x7fffffff; -} - -/* Should we be taking Vegas samples right now? */ -#define tcp_vegas_enabled(__tp) ((__tp)->vegas.doing_vegas_now) - -extern void tcp_ca_init(struct tcp_sock *tp); - -static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state) -{ - if (tcp_is_vegas(tp)) { - if (ca_state == TCP_CA_Open) - tcp_vegas_enable(tp); - else - tcp_vegas_disable(tp); - } - tp->ca_state = ca_state; -} - /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. * The exception is rate halving phase, when cwnd is decreasing towards * ssthresh. @@ -1262,33 +1236,11 @@ static inline void tcp_sync_left_out(struct tcp_sock *tp) tp->left_out = tp->sacked_out + tp->lost_out; } -extern void tcp_cwnd_application_limited(struct sock *sk); - -/* Congestion window validation. (RFC2861) */ - -static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp) -{ - __u32 packets_out = tp->packets_out; - - if (packets_out >= tp->snd_cwnd) { - /* Network is feed fully. */ - tp->snd_cwnd_used = 0; - tp->snd_cwnd_stamp = tcp_time_stamp; - } else { - /* Network starves. */ - if (tp->packets_out > tp->snd_cwnd_used) - tp->snd_cwnd_used = tp->packets_out; - - if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= tp->rto) - tcp_cwnd_application_limited(sk); - } -} - -/* Set slow start threshould and cwnd not falling to slow start */ +/* Set slow start threshold and cwnd not falling to slow start */ static inline void __tcp_enter_cwr(struct tcp_sock *tp) { tp->undo_marker = 0; - tp->snd_ssthresh = tcp_recalc_ssthresh(tp); + tp->snd_ssthresh = tp->ca_ops->ssthresh(tp); tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp) + 1U); tp->snd_cwnd_cnt = 0; @@ -1316,12 +1268,6 @@ static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp) return 3; } -static __inline__ int tcp_minshall_check(const struct tcp_sock *tp) -{ - return after(tp->snd_sml,tp->snd_una) && - !after(tp->snd_sml, tp->snd_nxt); -} - static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss, const struct sk_buff *skb) { @@ -1329,122 +1275,18 @@ static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss, tp->snd_sml = TCP_SKB_CB(skb)->end_seq; } -/* Return 0, if packet can be sent now without violation Nagle's rules: - 1. It is full sized. - 2. Or it contains FIN. - 3. Or TCP_NODELAY was set. - 4. Or TCP_CORK is not set, and all sent packets are ACKed. - With Minshall's modification: all sent small packets are ACKed. - */ - -static __inline__ int -tcp_nagle_check(const struct tcp_sock *tp, const struct sk_buff *skb, - unsigned mss_now, int nonagle) -{ - return (skb->len < mss_now && - !(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) && - ((nonagle&TCP_NAGLE_CORK) || - (!nonagle && - tp->packets_out && - tcp_minshall_check(tp)))); -} - -extern void tcp_set_skb_tso_segs(struct sock *, struct sk_buff *); - -/* This checks if the data bearing packet SKB (usually sk->sk_send_head) - * should be put on the wire right now. - */ -static __inline__ int tcp_snd_test(struct sock *sk, - struct sk_buff *skb, - unsigned cur_mss, int nonagle) -{ - struct tcp_sock *tp = tcp_sk(sk); - int pkts = tcp_skb_pcount(skb); - - if (!pkts) { - tcp_set_skb_tso_segs(sk, skb); - pkts = tcp_skb_pcount(skb); - } - - /* RFC 1122 - section 4.2.3.4 - * - * We must queue if - * - * a) The right edge of this frame exceeds the window - * b) There are packets in flight and we have a small segment - * [SWS avoidance and Nagle algorithm] - * (part of SWS is done on packetization) - * Minshall version sounds: there are no _small_ - * segments in flight. (tcp_nagle_check) - * c) We have too many packets 'in flight' - * - * Don't use the nagle rule for urgent data (or - * for the final FIN -DaveM). - * - * Also, Nagle rule does not apply to frames, which - * sit in the middle of queue (they have no chances - * to get new data) and if room at tail of skb is - * not enough to save something seriously (<32 for now). - */ - - /* Don't be strict about the congestion window for the - * final FIN frame. -DaveM - */ - return (((nonagle&TCP_NAGLE_PUSH) || tp->urg_mode - || !tcp_nagle_check(tp, skb, cur_mss, nonagle)) && - (((tcp_packets_in_flight(tp) + (pkts-1)) < tp->snd_cwnd) || - (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)) && - !after(TCP_SKB_CB(skb)->end_seq, tp->snd_una + tp->snd_wnd)); -} - static __inline__ void tcp_check_probe_timer(struct sock *sk, struct tcp_sock *tp) { if (!tp->packets_out && !tp->pending) tcp_reset_xmit_timer(sk, TCP_TIME_PROBE0, tp->rto); } -static __inline__ int tcp_skb_is_last(const struct sock *sk, - const struct sk_buff *skb) -{ - return skb->next == (struct sk_buff *)&sk->sk_write_queue; -} - -/* Push out any pending frames which were held back due to - * TCP_CORK or attempt at coalescing tiny packets. - * The socket must be locked by the caller. - */ -static __inline__ void __tcp_push_pending_frames(struct sock *sk, - struct tcp_sock *tp, - unsigned cur_mss, - int nonagle) -{ - struct sk_buff *skb = sk->sk_send_head; - - if (skb) { - if (!tcp_skb_is_last(sk, skb)) - nonagle = TCP_NAGLE_PUSH; - if (!tcp_snd_test(sk, skb, cur_mss, nonagle) || - tcp_write_xmit(sk, nonagle)) - tcp_check_probe_timer(sk, tp); - } - tcp_cwnd_validate(sk, tp); -} - static __inline__ void tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp) { __tcp_push_pending_frames(sk, tp, tcp_current_mss(sk, 1), tp->nonagle); } -static __inline__ int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp) -{ - struct sk_buff *skb = sk->sk_send_head; - - return (skb && - tcp_snd_test(sk, skb, tcp_current_mss(sk, 1), - tcp_skb_is_last(sk, skb) ? TCP_NAGLE_PUSH : tp->nonagle)); -} - static __inline__ void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq) { tp->snd_wl1 = seq; @@ -1876,52 +1718,4 @@ struct tcp_iter_state { extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo); extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo); -/* TCP Westwood functions and constants */ - -#define TCP_WESTWOOD_INIT_RTT (20*HZ) /* maybe too conservative?! */ -#define TCP_WESTWOOD_RTT_MIN (HZ/20) /* 50ms */ - -static inline void tcp_westwood_update_rtt(struct tcp_sock *tp, __u32 rtt_seq) -{ - if (tcp_is_westwood(tp)) - tp->westwood.rtt = rtt_seq; -} - -static inline __u32 __tcp_westwood_bw_rttmin(const struct tcp_sock *tp) -{ - return max((tp->westwood.bw_est) * (tp->westwood.rtt_min) / - (__u32) (tp->mss_cache_std), - 2U); -} - -static inline __u32 tcp_westwood_bw_rttmin(const struct tcp_sock *tp) -{ - return tcp_is_westwood(tp) ? __tcp_westwood_bw_rttmin(tp) : 0; -} - -static inline int tcp_westwood_ssthresh(struct tcp_sock *tp) -{ - __u32 ssthresh = 0; - - if (tcp_is_westwood(tp)) { - ssthresh = __tcp_westwood_bw_rttmin(tp); - if (ssthresh) - tp->snd_ssthresh = ssthresh; - } - - return (ssthresh != 0); -} - -static inline int tcp_westwood_cwnd(struct tcp_sock *tp) -{ - __u32 cwnd = 0; - - if (tcp_is_westwood(tp)) { - cwnd = __tcp_westwood_bw_rttmin(tp); - if (cwnd) - tp->snd_cwnd = cwnd; - } - - return (cwnd != 0); -} #endif /* _TCP_H */ |