diff options
Diffstat (limited to 'freebsd/sys/netinet/tcp_timer.c')
| -rw-r--r-- | freebsd/sys/netinet/tcp_timer.c | 110 |
1 files changed, 60 insertions, 50 deletions
diff --git a/freebsd/sys/netinet/tcp_timer.c b/freebsd/sys/netinet/tcp_timer.c index cbf9206f..4fe0645a 100644 --- a/freebsd/sys/netinet/tcp_timer.c +++ b/freebsd/sys/netinet/tcp_timer.c @@ -52,6 +52,7 @@ __FBSDID("$FreeBSD$"); #include <net/route.h> #include <net/vnet.h> +#include <netinet/cc.h> #include <netinet/in.h> #include <netinet/in_pcb.h> #include <netinet/in_systm.h> @@ -59,7 +60,6 @@ __FBSDID("$FreeBSD$"); #include <netinet6/in6_pcb.h> #endif #include <netinet/ip_var.h> -#include <netinet/tcp.h> #include <netinet/tcp_fsm.h> #include <netinet/tcp_timer.h> #include <netinet/tcp_var.h> @@ -119,6 +119,11 @@ int tcp_maxpersistidle; /* max idle time in persist */ int tcp_maxidle; +static int tcp_rexmit_drop_options = 1; +SYSCTL_INT(_net_inet_tcp, OID_AUTO, rexmit_drop_options, CTLFLAG_RW, + &tcp_rexmit_drop_options, 0, + "Drop TCP options from 3rd and later retransmitted SYN"); + /* * Tcp protocol timeout routine called every 500 ms. * Updates timestamps used for TCP @@ -178,13 +183,18 @@ tcp_timer_delack(void *xtp) return; } INP_WLOCK(inp); - if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_delack) - || !callout_active(&tp->t_timers->tt_delack)) { + if (callout_pending(&tp->t_timers->tt_delack) || + !callout_active(&tp->t_timers->tt_delack)) { INP_WUNLOCK(inp); CURVNET_RESTORE(); return; } callout_deactivate(&tp->t_timers->tt_delack); + if ((inp->inp_flags & INP_DROPPED) != 0) { + INP_WUNLOCK(inp); + CURVNET_RESTORE(); + return; + } tp->t_flags |= TF_ACKNOW; TCPSTAT_INC(tcps_delack); @@ -224,7 +234,7 @@ tcp_timer_2msl(void *xtp) } INP_WLOCK(inp); tcp_free_sackholes(tp); - if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_2msl) || + if (callout_pending(&tp->t_timers->tt_2msl) || !callout_active(&tp->t_timers->tt_2msl)) { INP_WUNLOCK(tp->t_inpcb); INP_INFO_WUNLOCK(&V_tcbinfo); @@ -232,6 +242,12 @@ tcp_timer_2msl(void *xtp) return; } callout_deactivate(&tp->t_timers->tt_2msl); + if ((inp->inp_flags & INP_DROPPED) != 0) { + INP_WUNLOCK(inp); + INP_INFO_WUNLOCK(&V_tcbinfo); + CURVNET_RESTORE(); + return; + } /* * 2 MSL timeout in shutdown went off. If we're closed but * still waiting for peer to close and connection has been idle @@ -295,14 +311,20 @@ tcp_timer_keep(void *xtp) return; } INP_WLOCK(inp); - if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_keep) - || !callout_active(&tp->t_timers->tt_keep)) { + if (callout_pending(&tp->t_timers->tt_keep) || + !callout_active(&tp->t_timers->tt_keep)) { INP_WUNLOCK(inp); INP_INFO_WUNLOCK(&V_tcbinfo); CURVNET_RESTORE(); return; } callout_deactivate(&tp->t_timers->tt_keep); + if ((inp->inp_flags & INP_DROPPED) != 0) { + INP_WUNLOCK(inp); + INP_INFO_WUNLOCK(&V_tcbinfo); + CURVNET_RESTORE(); + return; + } /* * Keep-alive timer went off; send something * or drop connection if idle for too long. @@ -390,14 +412,20 @@ tcp_timer_persist(void *xtp) return; } INP_WLOCK(inp); - if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_persist) - || !callout_active(&tp->t_timers->tt_persist)) { + if (callout_pending(&tp->t_timers->tt_persist) || + !callout_active(&tp->t_timers->tt_persist)) { INP_WUNLOCK(inp); INP_INFO_WUNLOCK(&V_tcbinfo); CURVNET_RESTORE(); return; } callout_deactivate(&tp->t_timers->tt_persist); + if ((inp->inp_flags & INP_DROPPED) != 0) { + INP_WUNLOCK(inp); + INP_INFO_WUNLOCK(&V_tcbinfo); + CURVNET_RESTORE(); + return; + } /* * Persistance timer into zero window. * Force a byte to be output, if possible. @@ -463,14 +491,20 @@ tcp_timer_rexmt(void * xtp) return; } INP_WLOCK(inp); - if ((inp->inp_flags & INP_DROPPED) || callout_pending(&tp->t_timers->tt_rexmt) - || !callout_active(&tp->t_timers->tt_rexmt)) { + if (callout_pending(&tp->t_timers->tt_rexmt) || + !callout_active(&tp->t_timers->tt_rexmt)) { INP_WUNLOCK(inp); INP_INFO_WUNLOCK(&V_tcbinfo); CURVNET_RESTORE(); return; } callout_deactivate(&tp->t_timers->tt_rexmt); + if ((inp->inp_flags & INP_DROPPED) != 0) { + INP_WUNLOCK(inp); + INP_INFO_WUNLOCK(&V_tcbinfo); + CURVNET_RESTORE(); + return; + } tcp_free_sackholes(tp); /* * Retransmission timer went off. Message has not @@ -499,12 +533,18 @@ tcp_timer_rexmt(void * xtp) tp->snd_cwnd_prev = tp->snd_cwnd; tp->snd_ssthresh_prev = tp->snd_ssthresh; tp->snd_recover_prev = tp->snd_recover; - if (IN_FASTRECOVERY(tp)) - tp->t_flags |= TF_WASFRECOVERY; + if (IN_FASTRECOVERY(tp->t_flags)) + tp->t_flags |= TF_WASFRECOVERY; else - tp->t_flags &= ~TF_WASFRECOVERY; + tp->t_flags &= ~TF_WASFRECOVERY; + if (IN_CONGRECOVERY(tp->t_flags)) + tp->t_flags |= TF_WASCRECOVERY; + else + tp->t_flags &= ~TF_WASCRECOVERY; tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1)); - } + tp->t_flags |= TF_PREVVALID; + } else + tp->t_flags &= ~TF_PREVVALID; TCPSTAT_INC(tcps_rexmttimeo); if (tp->t_state == TCPS_SYN_SENT) rexmt = TCP_REXMTVAL(tp) * tcp_syn_backoff[tp->t_rxtshift]; @@ -513,13 +553,14 @@ tcp_timer_rexmt(void * xtp) TCPT_RANGESET(tp->t_rxtcur, rexmt, tp->t_rttmin, TCPTV_REXMTMAX); /* - * Disable rfc1323 if we havn't got any response to + * Disable rfc1323 if we haven't got any response to * our third SYN to work-around some broken terminal servers * (most of which have hopefully been retired) that have bad VJ * header compression code which trashes TCP segments containing * unknown-to-them TCP options. */ - if ((tp->t_state == TCPS_SYN_SENT) && (tp->t_rxtshift == 3)) + if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) && + (tp->t_rxtshift == 3)) tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP); /* * If we backed off this far, our srtt estimate is probably bogus. @@ -546,40 +587,9 @@ tcp_timer_rexmt(void * xtp) * If timing a segment in this window, stop the timer. */ tp->t_rtttime = 0; - /* - * Close the congestion window down to one segment - * (we'll open it by one segment for each ack we get). - * Since we probably have a window's worth of unacked - * data accumulated, this "slow start" keeps us from - * dumping all that data as back-to-back packets (which - * might overwhelm an intermediate gateway). - * - * There are two phases to the opening: Initially we - * open by one mss on each ack. This makes the window - * size increase exponentially with time. If the - * window is larger than the path can handle, this - * exponential growth results in dropped packet(s) - * almost immediately. To get more time between - * drops but still "push" the network to take advantage - * of improving conditions, we switch from exponential - * to linear window opening at some threshhold size. - * For a threshhold, we use half the current window - * size, truncated to a multiple of the mss. - * - * (the minimum cwnd that will give us exponential - * growth is 2 mss. We don't allow the threshhold - * to go below this.) - */ - { - u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg; - if (win < 2) - win = 2; - tp->snd_cwnd = tp->t_maxseg; - tp->snd_ssthresh = win * tp->t_maxseg; - tp->t_dupacks = 0; - } - EXIT_FASTRECOVERY(tp); - tp->t_bytes_acked = 0; + + cc_cong_signal(tp, NULL, CC_RTO); + (void) tcp_output(tp); out: |