implement tcp_drain() similar to ip_drain(); ok mcbride@

3 files changed, 55 insertions, 7 deletions

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index f97c74cf018..2da98f80342 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_input.c,v 1.155 2004/02/11 20:12:33 markus Exp $	*/
+/*	$OpenBSD: tcp_input.c,v 1.156 2004/02/27 16:44:44 markus Exp $	*/
 /*	$NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $	*/
 
 /*
@@ -1221,8 +1221,10 @@ after_listen:
 				tp->snd_scale = tp->requested_s_scale;
 				tp->rcv_scale = tp->request_r_scale;
 			}
+			tcp_reass_lock(tp);
 			(void) tcp_reass(tp, (struct tcphdr *)0,
 				(struct mbuf *)0, &tlen);
+			tcp_reass_unlock(tp);
 			/*
 			 * if we didn't have to retransmit the SYN,
 			 * use its rtt as our initial srtt & rtt var.
@@ -1475,8 +1477,10 @@ trimthenstep6:
 			tp->snd_scale = tp->requested_s_scale;
 			tp->rcv_scale = tp->request_r_scale;
 		}
+		tcp_reass_lock(tp);
 		(void) tcp_reass(tp, (struct tcphdr *)0, (struct mbuf *)0,
 				 &tlen);
+		tcp_reass_unlock(tp);
 		tp->snd_wl1 = th->th_seq - 1;
 		/* fall into ... */
 
@@ -1979,8 +1983,10 @@ dodata:							/* XXX */
 	 */
 	if ((tlen || (tiflags & TH_FIN)) &&
 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
+		tcp_reass_lock(tp);
 		if (th->th_seq == tp->rcv_nxt && tp->segq.lh_first == NULL &&
 		    tp->t_state == TCPS_ESTABLISHED) {
+			tcp_reass_unlock(tp);
 			TCP_SETUP_ACK(tp, tiflags);
 			tp->rcv_nxt += tlen;
 			tiflags = th->th_flags & TH_FIN;
@@ -1997,6 +2003,7 @@ dodata:							/* XXX */
 		} else {
 			m_adj(m, hdroptlen);
 			tiflags = tcp_reass(tp, th, m, &tlen);
+			tcp_reass_unlock(tp);
 			tp->t_flags |= TF_ACKNOW;
 		}
 #ifdef TCP_SACK
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 662ccc2cc7f..b920816bad5 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_subr.c,v 1.75 2004/01/31 19:40:10 markus Exp $	*/
+/*	$OpenBSD: tcp_subr.c,v 1.76 2004/02/27 16:44:45 markus Exp $	*/
 /*	$NetBSD: tcp_subr.c,v 1.22 1996/02/13 23:44:00 christos Exp $	*/
 
 /*
@@ -681,7 +681,9 @@ tcp_close(struct tcpcb *tp)
 #endif /* RTV_RTT */
 
 	/* free the reassembly queue, if any */
+	tcp_reass_lock(tp);
 	tcp_freeq(tp);
+	tcp_reass_unlock(tp);
 
 	tcp_canceltimers(tp);
 	TCP_CLEAR_DELACK(tp);
@@ -724,7 +726,20 @@ tcp_freeq(struct tcpcb *tp)
 void
 tcp_drain()
 {
+	struct inpcb *inp;
+
+	/* called at splimp() */
+	CIRCLEQ_FOREACH(inp, &tcbtable.inpt_queue, inp_queue) {
+		struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb;
 
+		if (tp != NULL) {
+			if (tcp_reass_lock_try(tp) == 0)
+				continue;
+			if (tcp_freeq(tp))
+				tcpstat.tcps_conndrained++;
+			tcp_reass_unlock(tp);
+		}
+	}
 }
 
 /*
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 2a9dc5d7dbb..1347bafc8a9 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_var.h,v 1.59 2004/02/27 16:28:24 markus Exp $	*/
+/*	$OpenBSD: tcp_var.h,v 1.60 2004/02/27 16:44:45 markus Exp $	*/
 /*	$NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $	*/
 
 /*
@@ -82,7 +82,7 @@ struct tcpcb {
 #define TF_SEND_CWR	0x00020000	/* send CWR in next seg */
 #define TF_DISABLE_ECN	0x00040000	/* disable ECN for this connection */
 #endif
-#define TF_DEAD		0x00080000	/* dead and to-be-released */
+#define TF_REASSLOCK	0x00080000	/* reassembling or draining */
 
 	struct	mbuf *t_template;	/* skeletal packet for transmit */
 	struct	inpcb *t_inpcb;		/* back pointer to internet pcb */
@@ -209,7 +209,6 @@ do {									\
 		timeout_del(&(tp)->t_delack_to);			\
 	}								\
 } while (/*CONSTCOND*/0)
-#endif /* _KERNEL */
 
 /*
  * Handy way of passing around TCP option info.
@@ -221,8 +220,6 @@ struct tcp_opt_info {
 	u_int16_t	maxseg;
 };
 
-#ifdef _KERNEL
-
 /*
  * Data for the TCP compressed state engine.
  */
@@ -284,6 +281,35 @@ struct syn_cache_head {
 	TAILQ_HEAD(, syn_cache) sch_bucket;	/* bucket entries */
 	u_short sch_length;			/* # entries in bucket */
 };
+
+static __inline int tcp_reass_lock_try(struct tcpcb *);
+static __inline void tcp_reass_unlock(struct tcpcb *);
+#define tcp_reass_lock(tp) tcp_reass_lock_try(tp)
+
+static __inline int
+tcp_reass_lock_try(struct tcpcb *tp)
+{
+	int s;
+
+	s = splimp();
+	if (tp->t_flags & TF_REASSLOCK) {
+		splx(s);
+		return (0);
+	}
+	tp->t_flags |= TF_REASSLOCK;
+	splx(s);
+	return (1);
+}
+
+static __inline void
+tcp_reass_unlock(struct tcpcb *tp)
+{
+	int s;
+
+	s = splimp();
+	tp->t_flags &= ~TF_REASSLOCK;
+	splx(s);
+}
 #endif /* _KERNEL */
 
 /*