Differential D4055 Diff 11335 head/sys/netinet/tcp_input.c

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head/sys/netinet/tcp_input.c

Show First 20 Lines • Show All 224 Lines • ▼ Show 20 Lines
SYSCTL_INT(_net_inet_tcp, OID_AUTO, recvbuf_max, CTLFLAG_VNET \| CTLFLAG_RW,		SYSCTL_INT(_net_inet_tcp, OID_AUTO, recvbuf_max, CTLFLAG_VNET \| CTLFLAG_RW,
&VNET_NAME(tcp_autorcvbuf_max), 0,		&VNET_NAME(tcp_autorcvbuf_max), 0,
"Max size of automatic receive buffer");		"Max size of automatic receive buffer");

VNET_DEFINE(struct inpcbhead, tcb);		VNET_DEFINE(struct inpcbhead, tcb);
#define tcb6 tcb /* for KAME src sync over BSD's /		#define tcb6 tcb /* for KAME src sync over BSD's /
VNET_DEFINE(struct inpcbinfo, tcbinfo);		VNET_DEFINE(struct inpcbinfo, tcbinfo);

static void tcp_dooptions(struct tcpopt , u_char , int, int);
static void tcp_do_segment(struct mbuf , struct tcphdr ,
struct socket , struct tcpcb , int, int, uint8_t,
int);
static void tcp_dropwithreset(struct mbuf , struct tcphdr ,
struct tcpcb *, int, int);
static void tcp_pulloutofband(struct socket *,
struct tcphdr , struct mbuf , int);
static void tcp_xmit_timer(struct tcpcb *, int);
static void tcp_newreno_partial_ack(struct tcpcb , struct tcphdr );
static void inline cc_ack_received(struct tcpcb tp, struct tcphdr th,
uint16_t type);
static void inline cc_conn_init(struct tcpcb *tp);
static void inline cc_post_recovery(struct tcpcb tp, struct tcphdr th);
static void inline hhook_run_tcp_est_in(struct tcpcb *tp,
struct tcphdr th, struct tcpopt to);

/*		/*
* TCP statistics are stored in an "array" of counter(9)s.		* TCP statistics are stored in an "array" of counter(9)s.
*/		*/
VNET_PCPUSTAT_DEFINE(struct tcpstat, tcpstat);		VNET_PCPUSTAT_DEFINE(struct tcpstat, tcpstat);
VNET_PCPUSTAT_SYSINIT(tcpstat);		VNET_PCPUSTAT_SYSINIT(tcpstat);
SYSCTL_VNET_PCPUSTAT(_net_inet_tcp, TCPCTL_STATS, stats, struct tcpstat,		SYSCTL_VNET_PCPUSTAT(_net_inet_tcp, TCPCTL_STATS, stats, struct tcpstat,
tcpstat, "TCP statistics (struct tcpstat, netinet/tcp_var.h)");		tcpstat, "TCP statistics (struct tcpstat, netinet/tcp_var.h)");

Show All 9 Lines
{		{

counter_u64_add(VNET(tcpstat)[statnum], 1);		counter_u64_add(VNET(tcpstat)[statnum], 1);
}		}

/*		/*
* Wrapper for the TCP established input helper hook.		* Wrapper for the TCP established input helper hook.
*/		*/
static void inline		void
hhook_run_tcp_est_in(struct tcpcb tp, struct tcphdr th, struct tcpopt *to)		hhook_run_tcp_est_in(struct tcpcb tp, struct tcphdr th, struct tcpopt *to)
{		{
struct tcp_hhook_data hhook_data;		struct tcp_hhook_data hhook_data;

if (V_tcp_hhh[HHOOK_TCP_EST_IN]->hhh_nhooks > 0) {		if (V_tcp_hhh[HHOOK_TCP_EST_IN]->hhh_nhooks > 0) {
hhook_data.tp = tp;		hhook_data.tp = tp;
hhook_data.th = th;		hhook_data.th = th;
hhook_data.to = to;		hhook_data.to = to;

hhook_run_hooks(V_tcp_hhh[HHOOK_TCP_EST_IN], &hhook_data,		hhook_run_hooks(V_tcp_hhh[HHOOK_TCP_EST_IN], &hhook_data,
tp->osd);		tp->osd);
}		}
}		}

/*		/*
* CC wrapper hook functions		* CC wrapper hook functions
*/		*/
static void inline		void
cc_ack_received(struct tcpcb tp, struct tcphdr th, uint16_t type)		cc_ack_received(struct tcpcb tp, struct tcphdr th, uint16_t type)
{		{
INP_WLOCK_ASSERT(tp->t_inpcb);		INP_WLOCK_ASSERT(tp->t_inpcb);

tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th);		tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th);
if (tp->snd_cwnd <= tp->snd_wnd)		if (tp->snd_cwnd <= tp->snd_wnd)
tp->ccv->flags \|= CCF_CWND_LIMITED;		tp->ccv->flags \|= CCF_CWND_LIMITED;
else		else
Show All 15 Lines	cc_ack_received(struct tcpcb tp, struct tcphdr th, uint16_t type)

if (CC_ALGO(tp)->ack_received != NULL) {		if (CC_ALGO(tp)->ack_received != NULL) {
/* XXXLAS: Find a way to live without this */		/* XXXLAS: Find a way to live without this */
tp->ccv->curack = th->th_ack;		tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->ack_received(tp->ccv, type);		CC_ALGO(tp)->ack_received(tp->ccv, type);
}		}
}		}

static void inline		void
cc_conn_init(struct tcpcb *tp)		cc_conn_init(struct tcpcb *tp)
{		{
struct hc_metrics_lite metrics;		struct hc_metrics_lite metrics;
struct inpcb *inp = tp->t_inpcb;		struct inpcb *inp = tp->t_inpcb;
int rtt;		int rtt;

INP_WLOCK_ASSERT(tp->t_inpcb);		INP_WLOCK_ASSERT(tp->t_inpcb);

▲ Show 20 Lines • Show All 107 Lines • ▼ Show 20 Lines	cc_cong_signal(struct tcpcb tp, struct tcphdr th, uint32_t type)

if (CC_ALGO(tp)->cong_signal != NULL) {		if (CC_ALGO(tp)->cong_signal != NULL) {
if (th != NULL)		if (th != NULL)
tp->ccv->curack = th->th_ack;		tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->cong_signal(tp->ccv, type);		CC_ALGO(tp)->cong_signal(tp->ccv, type);
}		}
}		}

static void inline		void inline
cc_post_recovery(struct tcpcb tp, struct tcphdr th)		cc_post_recovery(struct tcpcb tp, struct tcphdr th)
{		{
INP_WLOCK_ASSERT(tp->t_inpcb);		INP_WLOCK_ASSERT(tp->t_inpcb);

/* XXXLAS: KASSERT that we're in recovery? */		/* XXXLAS: KASSERT that we're in recovery? */

if (CC_ALGO(tp)->post_recovery != NULL) {		if (CC_ALGO(tp)->post_recovery != NULL) {
tp->ccv->curack = th->th_ack;		tp->ccv->curack = th->th_ack;
▲ Show 20 Lines • Show All 138 Lines • ▼ Show 20 Lines	#ifdef INET6
struct ip6_hdr *ip6 = NULL;		struct ip6_hdr *ip6 = NULL;
int isipv6;		int isipv6;
#else		#else
const void *ip6 = NULL;		const void *ip6 = NULL;
#endif /* INET6 */		#endif /* INET6 */
struct tcpopt to; /* options in this segment */		struct tcpopt to; /* options in this segment */
char s = NULL; / address and port logging */		char s = NULL; / address and port logging */
int ti_locked;		int ti_locked;
#define TI_UNLOCKED 1
#define TI_RLOCKED 2

#ifdef TCPDEBUG		#ifdef TCPDEBUG
/*		/*
* The size of tcp_saveipgen must be the size of the max ip header,		* The size of tcp_saveipgen must be the size of the max ip header,
* now IPv6.		* now IPv6.
*/		*/
u_char tcp_saveipgen[IP6_HDR_LEN];		u_char tcp_saveipgen[IP6_HDR_LEN];
struct tcphdr tcp_savetcp;		struct tcphdr tcp_savetcp;
short ostate = 0;		short ostate = 0;
▲ Show 20 Lines • Show All 555 Lines • ▼ Show 20 Lines	#ifdef TCP_SIGNATURE
}		}
#endif		#endif

/*		/*
* Process the segment and the data it		* Process the segment and the data it
* contains. tcp_do_segment() consumes		* contains. tcp_do_segment() consumes
* the mbuf chain and unlocks the inpcb.		* the mbuf chain and unlocks the inpcb.
*/		*/
tcp_do_segment(m, th, so, tp, drop_hdrlen, tlen,		tp->t_fb->tfb_tcp_do_segment(m, th, so, tp, drop_hdrlen, tlen,
iptos, ti_locked);		iptos, ti_locked);
INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);		INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
return (IPPROTO_DONE);		return (IPPROTO_DONE);
}		}
/*		/*
* Segment flag validation for new connection attempts:		* Segment flag validation for new connection attempts:
*		*
* Our (SYN\|ACK) response was rejected.		* Our (SYN\|ACK) response was rejected.
▲ Show 20 Lines • Show All 229 Lines • ▼ Show 20 Lines	#endif

TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);		TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);

/*		/*
* Segment belongs to a connection in SYN_SENT, ESTABLISHED or later		* Segment belongs to a connection in SYN_SENT, ESTABLISHED or later
* state. tcp_do_segment() always consumes the mbuf chain, unlocks		* state. tcp_do_segment() always consumes the mbuf chain, unlocks
* the inpcb, and unlocks pcbinfo.		* the inpcb, and unlocks pcbinfo.
*/		*/
tcp_do_segment(m, th, so, tp, drop_hdrlen, tlen, iptos, ti_locked);		tp->t_fb->tfb_tcp_do_segment(m, th, so, tp, drop_hdrlen, tlen, iptos, ti_locked);
INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);		INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
return (IPPROTO_DONE);		return (IPPROTO_DONE);

dropwithreset:		dropwithreset:
TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);		TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);

if (ti_locked == TI_RLOCKED) {		if (ti_locked == TI_RLOCKED) {
INP_INFO_RUNLOCK(&V_tcbinfo);		INP_INFO_RUNLOCK(&V_tcbinfo);
Show All 38 Lines	drop:
INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);		INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
if (s != NULL)		if (s != NULL)
free(s, M_TCPLOG);		free(s, M_TCPLOG);
if (m != NULL)		if (m != NULL)
m_freem(m);		m_freem(m);
return (IPPROTO_DONE);		return (IPPROTO_DONE);
}		}

static void		void
tcp_do_segment(struct mbuf m, struct tcphdr th, struct socket *so,		tcp_do_segment(struct mbuf m, struct tcphdr th, struct socket *so,
struct tcpcb *tp, int drop_hdrlen, int tlen, uint8_t iptos,		struct tcpcb *tp, int drop_hdrlen, int tlen, uint8_t iptos,
int ti_locked)		int ti_locked)
{		{
int thflags, acked, ourfinisacked, needoutput = 0, sack_changed;		int thflags, acked, ourfinisacked, needoutput = 0, sack_changed;
int rstreason, todrop, win;		int rstreason, todrop, win;
u_long tiwin;		u_long tiwin;
char *s;		char *s;
▲ Show 20 Lines • Show All 295 Lines • ▼ Show 20 Lines	#endif
mtod(m, const char *));		mtod(m, const char *));
if (tp->snd_una == tp->snd_max)		if (tp->snd_una == tp->snd_max)
tcp_timer_activate(tp, TT_REXMT, 0);		tcp_timer_activate(tp, TT_REXMT, 0);
else if (!tcp_timer_active(tp, TT_PERSIST))		else if (!tcp_timer_active(tp, TT_PERSIST))
tcp_timer_activate(tp, TT_REXMT,		tcp_timer_activate(tp, TT_REXMT,
tp->t_rxtcur);		tp->t_rxtcur);
sowwakeup(so);		sowwakeup(so);
if (sbavail(&so->so_snd))		if (sbavail(&so->so_snd))
(void) tcp_output(tp);		(void) tp->t_fb->tfb_tcp_output(tp);
goto check_delack;		goto check_delack;
}		}
} else if (th->th_ack == tp->snd_una &&		} else if (th->th_ack == tp->snd_una &&
tlen <= sbspace(&so->so_rcv)) {		tlen <= sbspace(&so->so_rcv)) {
int newsize = 0; /* automatic sockbuf scaling */		int newsize = 0; /* automatic sockbuf scaling */

/*		/*
* This is a pure, in-sequence data packet with		* This is a pure, in-sequence data packet with
▲ Show 20 Lines • Show All 102 Lines • ▼ Show 20 Lines	*/
sbappendstream_locked(&so->so_rcv, m, 0);		sbappendstream_locked(&so->so_rcv, m, 0);
}		}
/* NB: sorwakeup_locked() does an implicit unlock. */		/* NB: sorwakeup_locked() does an implicit unlock. */
sorwakeup_locked(so);		sorwakeup_locked(so);
if (DELAY_ACK(tp, tlen)) {		if (DELAY_ACK(tp, tlen)) {
tp->t_flags \|= TF_DELACK;		tp->t_flags \|= TF_DELACK;
} else {		} else {
tp->t_flags \|= TF_ACKNOW;		tp->t_flags \|= TF_ACKNOW;
tcp_output(tp);		tp->t_fb->tfb_tcp_output(tp);
}		}
goto check_delack;		goto check_delack;
}		}
}		}

/*		/*
* Calculate amount of space in receive window,		* Calculate amount of space in receive window,
* and then do TCP input processing.		* and then do TCP input processing.
▲ Show 20 Lines • Show All 598 Lines • ▼ Show 20 Lines	if (SEQ_LEQ(th->th_ack, tp->snd_una)) {

if (awnd < tp->snd_ssthresh) {		if (awnd < tp->snd_ssthresh) {
tp->snd_cwnd += tp->t_maxseg;		tp->snd_cwnd += tp->t_maxseg;
if (tp->snd_cwnd > tp->snd_ssthresh)		if (tp->snd_cwnd > tp->snd_ssthresh)
tp->snd_cwnd = tp->snd_ssthresh;		tp->snd_cwnd = tp->snd_ssthresh;
}		}
} else		} else
tp->snd_cwnd += tp->t_maxseg;		tp->snd_cwnd += tp->t_maxseg;
(void) tcp_output(tp);		(void) tp->t_fb->tfb_tcp_output(tp);
goto drop;		goto drop;
} else if (tp->t_dupacks == tcprexmtthresh) {		} else if (tp->t_dupacks == tcprexmtthresh) {
tcp_seq onxt = tp->snd_nxt;		tcp_seq onxt = tp->snd_nxt;

/*		/*
* If we're doing sack, check to		* If we're doing sack, check to
* see if we're already in sack		* see if we're already in sack
* recovery. If we're not doing sack,		* recovery. If we're not doing sack,
Show All 17 Lines	if (SEQ_LEQ(th->th_ack, tp->snd_una)) {
cc_ack_received(tp, th, CC_DUPACK);		cc_ack_received(tp, th, CC_DUPACK);
tcp_timer_activate(tp, TT_REXMT, 0);		tcp_timer_activate(tp, TT_REXMT, 0);
tp->t_rtttime = 0;		tp->t_rtttime = 0;
if (tp->t_flags & TF_SACK_PERMIT) {		if (tp->t_flags & TF_SACK_PERMIT) {
TCPSTAT_INC(		TCPSTAT_INC(
tcps_sack_recovery_episode);		tcps_sack_recovery_episode);
tp->sack_newdata = tp->snd_nxt;		tp->sack_newdata = tp->snd_nxt;
tp->snd_cwnd = tp->t_maxseg;		tp->snd_cwnd = tp->t_maxseg;
(void) tcp_output(tp);		(void) tp->t_fb->tfb_tcp_output(tp);
goto drop;		goto drop;
}		}
tp->snd_nxt = th->th_ack;		tp->snd_nxt = th->th_ack;
tp->snd_cwnd = tp->t_maxseg;		tp->snd_cwnd = tp->t_maxseg;
(void) tcp_output(tp);		(void) tp->t_fb->tfb_tcp_output(tp);
KASSERT(tp->snd_limited <= 2,		KASSERT(tp->snd_limited <= 2,
("%s: tp->snd_limited too big",		("%s: tp->snd_limited too big",
__func__));		__func__));
tp->snd_cwnd = tp->snd_ssthresh +		tp->snd_cwnd = tp->snd_ssthresh +
tp->t_maxseg *		tp->t_maxseg *
(tp->t_dupacks - tp->snd_limited);		(tp->t_dupacks - tp->snd_limited);
if (SEQ_GT(onxt, tp->snd_nxt))		if (SEQ_GT(onxt, tp->snd_nxt))
tp->snd_nxt = onxt;		tp->snd_nxt = onxt;
Show All 30 Lines	if (SEQ_LEQ(th->th_ack, tp->snd_una)) {
* is new data available to be sent.		* is new data available to be sent.
* Otherwise we would send pure ACKs.		* Otherwise we would send pure ACKs.
*/		*/
SOCKBUF_LOCK(&so->so_snd);		SOCKBUF_LOCK(&so->so_snd);
avail = sbavail(&so->so_snd) -		avail = sbavail(&so->so_snd) -
(tp->snd_nxt - tp->snd_una);		(tp->snd_nxt - tp->snd_una);
SOCKBUF_UNLOCK(&so->so_snd);		SOCKBUF_UNLOCK(&so->so_snd);
if (avail > 0)		if (avail > 0)
(void) tcp_output(tp);		(void) tp->t_fb->tfb_tcp_output(tp);
sent = tp->snd_max - oldsndmax;		sent = tp->snd_max - oldsndmax;
if (sent > tp->t_maxseg) {		if (sent > tp->t_maxseg) {
KASSERT((tp->t_dupacks == 2 &&		KASSERT((tp->t_dupacks == 2 &&
tp->snd_limited == 0) \|\|		tp->snd_limited == 0) \|\|
(sent == tp->t_maxseg + 1 &&		(sent == tp->t_maxseg + 1 &&
tp->t_flags & TF_SENTFIN),		tp->t_flags & TF_SENTFIN),
("%s: sent too much",		("%s: sent too much",
__func__));		__func__));
▲ Show 20 Lines • Show All 449 Lines • ▼ Show 20 Lines	tcp_trace(TA_INPUT, ostate, tp, (void *)tcp_saveipgen,
&tcp_savetcp, 0);		&tcp_savetcp, 0);
#endif		#endif
TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));		TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));

/*		/*
* Return any desired output.		* Return any desired output.
*/		*/
if (needoutput \|\| (tp->t_flags & TF_ACKNOW))		if (needoutput \|\| (tp->t_flags & TF_ACKNOW))
(void) tcp_output(tp);		(void) tp->t_fb->tfb_tcp_output(tp);

check_delack:		check_delack:
KASSERT(ti_locked == TI_UNLOCKED, ("%s: check_delack ti_locked %d",		KASSERT(ti_locked == TI_UNLOCKED, ("%s: check_delack ti_locked %d",
__func__, ti_locked));		__func__, ti_locked));
INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);		INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
INP_WLOCK_ASSERT(tp->t_inpcb);		INP_WLOCK_ASSERT(tp->t_inpcb);

if (tp->t_flags & TF_DELACK) {		if (tp->t_flags & TF_DELACK) {
Show All 31 Lines	tcp_trace(TA_DROP, ostate, tp, (void *)tcp_saveipgen,
&tcp_savetcp, 0);		&tcp_savetcp, 0);
#endif		#endif
TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));		TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
if (ti_locked == TI_RLOCKED)		if (ti_locked == TI_RLOCKED)
INP_INFO_RUNLOCK(&V_tcbinfo);		INP_INFO_RUNLOCK(&V_tcbinfo);
ti_locked = TI_UNLOCKED;		ti_locked = TI_UNLOCKED;

tp->t_flags \|= TF_ACKNOW;		tp->t_flags \|= TF_ACKNOW;
(void) tcp_output(tp);		(void) tp->t_fb->tfb_tcp_output(tp);
INP_WUNLOCK(tp->t_inpcb);		INP_WUNLOCK(tp->t_inpcb);
m_freem(m);		m_freem(m);
return;		return;

dropwithreset:		dropwithreset:
if (ti_locked == TI_RLOCKED)		if (ti_locked == TI_RLOCKED)
INP_INFO_RUNLOCK(&V_tcbinfo);		INP_INFO_RUNLOCK(&V_tcbinfo);
ti_locked = TI_UNLOCKED;		ti_locked = TI_UNLOCKED;
Show All 29 Lines	#endif
m_freem(m);		m_freem(m);
}		}

/*		/*
* Issue RST and make ACK acceptable to originator of segment.		* Issue RST and make ACK acceptable to originator of segment.
* The mbuf must still include the original packet header.		* The mbuf must still include the original packet header.
* tp may be NULL.		* tp may be NULL.
*/		*/
static void		void
tcp_dropwithreset(struct mbuf m, struct tcphdr th, struct tcpcb *tp,		tcp_dropwithreset(struct mbuf m, struct tcphdr th, struct tcpcb *tp,
int tlen, int rstreason)		int tlen, int rstreason)
{		{
#ifdef INET		#ifdef INET
struct ip *ip;		struct ip *ip;
#endif		#endif
#ifdef INET6		#ifdef INET6
struct ip6_hdr *ip6;		struct ip6_hdr *ip6;
▲ Show 20 Lines • Show All 46 Lines • ▼ Show 20 Lines	#endif
return;		return;
drop:		drop:
m_freem(m);		m_freem(m);
}		}

/*		/*
* Parse TCP options and place in tcpopt.		* Parse TCP options and place in tcpopt.
*/		*/
static void		void
tcp_dooptions(struct tcpopt to, u_char cp, int cnt, int flags)		tcp_dooptions(struct tcpopt to, u_char cp, int cnt, int flags)
{		{
int opt, optlen;		int opt, optlen;

to->to_flags = 0;		to->to_flags = 0;
for (; cnt > 0; cnt -= optlen, cp += optlen) {		for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[0];		opt = cp[0];
if (opt == TCPOPT_EOL)		if (opt == TCPOPT_EOL)
▲ Show 20 Lines • Show All 77 Lines • ▼ Show 20 Lines
}		}

/*		/*
* Pull out of band byte out of a segment so		* Pull out of band byte out of a segment so
* it doesn't appear in the user's data queue.		* it doesn't appear in the user's data queue.
* It is still reflected in the segment length for		* It is still reflected in the segment length for
* sequencing purposes.		* sequencing purposes.
*/		*/
static void		void
tcp_pulloutofband(struct socket so, struct tcphdr th, struct mbuf *m,		tcp_pulloutofband(struct socket so, struct tcphdr th, struct mbuf *m,
int off)		int off)
{		{
int cnt = off + th->th_urp - 1;		int cnt = off + th->th_urp - 1;

while (cnt >= 0) {		while (cnt >= 0) {
if (m->m_len > cnt) {		if (m->m_len > cnt) {
char *cp = mtod(m, caddr_t) + cnt;		char *cp = mtod(m, caddr_t) + cnt;
Show All 16 Lines	tcp_pulloutofband(struct socket so, struct tcphdr th, struct mbuf *m,
}		}
panic("tcp_pulloutofband");		panic("tcp_pulloutofband");
}		}

/*		/*
* Collect new round-trip time estimate		* Collect new round-trip time estimate
* and update averages and current timeout.		* and update averages and current timeout.
*/		*/
static void		void
tcp_xmit_timer(struct tcpcb *tp, int rtt)		tcp_xmit_timer(struct tcpcb *tp, int rtt)
{		{
int delta;		int delta;

INP_WLOCK_ASSERT(tp->t_inpcb);		INP_WLOCK_ASSERT(tp->t_inpcb);

TCPSTAT_INC(tcps_rttupdated);		TCPSTAT_INC(tcps_rttupdated);
tp->t_rttupdated++;		tp->t_rttupdated++;
▲ Show 20 Lines • Show All 363 Lines • ▼ Show 20 Lines


/*		/*
* On a partial ack arrives, force the retransmission of the		* On a partial ack arrives, force the retransmission of the
* next unacknowledged segment. Do not clear tp->t_dupacks.		* next unacknowledged segment. Do not clear tp->t_dupacks.
* By setting snd_nxt to ti_ack, this forces retransmission timer to		* By setting snd_nxt to ti_ack, this forces retransmission timer to
* be started again.		* be started again.
*/		*/
static void		void
tcp_newreno_partial_ack(struct tcpcb tp, struct tcphdr th)		tcp_newreno_partial_ack(struct tcpcb tp, struct tcphdr th)
{		{
tcp_seq onxt = tp->snd_nxt;		tcp_seq onxt = tp->snd_nxt;
u_long ocwnd = tp->snd_cwnd;		u_long ocwnd = tp->snd_cwnd;

INP_WLOCK_ASSERT(tp->t_inpcb);		INP_WLOCK_ASSERT(tp->t_inpcb);

tcp_timer_activate(tp, TT_REXMT, 0);		tcp_timer_activate(tp, TT_REXMT, 0);
tp->t_rtttime = 0;		tp->t_rtttime = 0;
tp->snd_nxt = th->th_ack;		tp->snd_nxt = th->th_ack;
/*		/*
* Set snd_cwnd to one segment beyond acknowledged offset.		* Set snd_cwnd to one segment beyond acknowledged offset.
* (tp->snd_una has not yet been updated when this function is called.)		* (tp->snd_una has not yet been updated when this function is called.)
*/		*/
tp->snd_cwnd = tp->t_maxseg + BYTES_THIS_ACK(tp, th);		tp->snd_cwnd = tp->t_maxseg + BYTES_THIS_ACK(tp, th);
tp->t_flags \|= TF_ACKNOW;		tp->t_flags \|= TF_ACKNOW;
(void) tcp_output(tp);		(void) tp->t_fb->tfb_tcp_output(tp);
tp->snd_cwnd = ocwnd;		tp->snd_cwnd = ocwnd;
if (SEQ_GT(onxt, tp->snd_nxt))		if (SEQ_GT(onxt, tp->snd_nxt))
tp->snd_nxt = onxt;		tp->snd_nxt = onxt;
/*		/*
* Partial window deflation. Relies on fact that tp->snd_una		* Partial window deflation. Relies on fact that tp->snd_una
* not updated yet.		* not updated yet.
*/		*/
if (tp->snd_cwnd > BYTES_THIS_ACK(tp, th))		if (tp->snd_cwnd > BYTES_THIS_ACK(tp, th))
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