tcp: retire rstreason

With the latest changes, this variable and parameter for
tcp_dropwithreset() is not needed anymore.
It also makes it harder to introduce the usage of multiple counters
for TCP again, which might open side channel attacks.
No funtional changes intended.

Reviewed by:		rrs
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D51872

sys/netinet/tcp_input.c

@@ -609,7 +609,6 @@ tcp_input_with_port(struct mbuf **mp, int *offp, int proto, uint16_t port)
 	int tlen = 0, off;
 	int drop_hdrlen;
 	int thflags;
-	int rstreason = 0;	/* For badport_bandlim accounting purposes */
 	int lookupflag;
 	uint8_t iptos;
 	struct m_tag *fwd_tag = NULL;
@@ -921,7 +920,6 @@ findpcb:
 			}
 			closed_port = true;
 		}
-		rstreason = BANDLIM_TCP_RST;
 		goto dropwithreset;
 	}
 	INP_LOCK_ASSERT(inp);
@@ -1012,13 +1010,11 @@ findpcb:
 		 * down or it is in the CLOSED state.  Either way we drop the
 		 * segment and send an appropriate response.
 		 */
-		rstreason = BANDLIM_TCP_RST;
 		closed_port = true;
 		goto dropwithreset;
 	}
 
 	if ((tp->t_port != port) && (tp->t_state > TCPS_LISTEN)) {
-		rstreason = BANDLIM_TCP_RST;
 		closed_port = true;
 		goto dropwithreset;
 	}
@@ -1134,7 +1130,6 @@ tfo_socket_result:
 					    V_tcp_sc_rst_sock_fail ?
 					    "sending RST" : "try again");
 				if (V_tcp_sc_rst_sock_fail) {
-					rstreason = BANDLIM_TCP_RST;
 					goto dropwithreset;
 				} else
 					goto dropunlock;
@@ -1201,7 +1196,6 @@ tfo_socket_result:
 				    s, __func__);
 			syncache_badack(&inc, port);	/* XXX: Not needed! */
 			TCPSTAT_INC(tcps_badsyn);
-			rstreason = BANDLIM_TCP_RST;
 			goto dropwithreset;
 		}
 		/*
@@ -1277,7 +1271,6 @@ tfo_socket_result:
 					"Connection attempt to deprecated "
 					"IPv6 address rejected\n",
 					s, __func__);
-				rstreason = BANDLIM_TCP_RST;
 				goto dropwithreset;
 			}
 		}
@@ -1398,8 +1391,7 @@ dropwithreset:
 	 * When blackholing do not respond with a RST but
 	 * completely ignore the segment and drop it.
 	 */
-	if (rstreason == BANDLIM_TCP_RST &&
-	    ((!closed_port && V_blackhole == 3) ||
+	if (((!closed_port && V_blackhole == 3) ||
 	     (closed_port &&
 	      ((V_blackhole == 1 && (thflags & TH_SYN)) || V_blackhole > 1))) &&
 	    (V_blackhole_local || (
@@ -1414,7 +1406,7 @@ dropwithreset:
 	    )))
 		goto dropunlock;
 	TCP_PROBE5(receive, NULL, tp, m, tp, th);
-	tcp_dropwithreset(m, th, tp, tlen, rstreason);
+	tcp_dropwithreset(m, th, tp, tlen);
 	m = NULL;	/* mbuf chain got consumed. */
 
 dropunlock:
@@ -1523,7 +1515,7 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
 	uint16_t thflags;
 	int acked, ourfinisacked, needoutput = 0;
 	sackstatus_t sack_changed;
-	int rstreason, todrop, win, incforsyn = 0;
+	int todrop, win, incforsyn = 0;
 	uint32_t tiwin;
 	uint16_t nsegs;
 	char *s;
@@ -1568,7 +1560,6 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
 	 */
 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
-		rstreason = BANDLIM_TCP_RST;
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 		goto dropwithreset;
 	}
@@ -1984,7 +1975,6 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
 		if ((thflags & TH_ACK) &&
 		    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
 		     SEQ_GT(th->th_ack, tp->snd_max))) {
-				rstreason = BANDLIM_TCP_RST;
 				tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 				goto dropwithreset;
 		}
@@ -1997,7 +1987,6 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
 			 * FIN, or a RST.
 			 */
 			if ((thflags & (TH_SYN|TH_ACK)) == (TH_SYN|TH_ACK)) {
-				rstreason = BANDLIM_TCP_RST;
 				tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 				goto dropwithreset;
 			} else if (thflags & TH_SYN) {
@@ -2264,7 +2253,6 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
 	 * for the "LAND" DoS attack.
 	 */
 	if (tp->t_state == TCPS_SYN_RECEIVED && SEQ_LT(th->th_seq, tp->irs)) {
-		rstreason = BANDLIM_TCP_RST;
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 		goto dropwithreset;
 	}
@@ -2346,7 +2334,6 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
 		tp = tcp_close(tp);
 		TCPSTAT_INC(tcps_rcvafterclose);
-		rstreason = BANDLIM_TCP_RST;
 		goto dropwithreset;
 	}
 
@@ -3443,7 +3430,6 @@ dropafterack:
 	if (tp->t_state == TCPS_SYN_RECEIVED && (thflags & TH_ACK) &&
 	    (SEQ_GT(tp->snd_una, th->th_ack) ||
 	     SEQ_GT(th->th_ack, tp->snd_max)) ) {
-		rstreason = BANDLIM_TCP_RST;
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 		goto dropwithreset;
 	}
@@ -3455,11 +3441,10 @@ dropafterack:
 	return;
 
 dropwithreset:
+	tcp_dropwithreset(m, th, NULL, tlen);
 	if (tp != NULL) {
-		tcp_dropwithreset(m, th, tp, tlen, rstreason);
 		INP_WUNLOCK(inp);
-	} else
-		tcp_dropwithreset(m, th, NULL, tlen, rstreason);
+	}
 	return;
 
 drop:
@@ -3479,8 +3464,7 @@ drop:
  * tp may be NULL.
  */
 void
-tcp_dropwithreset(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp,
-    int tlen, int rstreason)
+tcp_dropwithreset(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp, int tlen)
 {
 #ifdef INET
 	struct ip *ip;
@@ -3520,7 +3504,7 @@ tcp_dropwithreset(struct mbuf *m, struct tcphdr *th, struct tcpcb *tp,
 #endif
 
 	/* Perform bandwidth limiting. */
-	if (badport_bandlim(rstreason) < 0)
+	if (badport_bandlim(BANDLIM_TCP_RST) < 0)
 		goto drop;
 
 	/* tcp_respond consumes the mbuf chain. */

sys/netinet/tcp_stacks/bbr.c

@@ -7863,7 +7863,7 @@ nothing_left:
 			/* tcp_close will kill the inp pre-log the Reset */
 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
 			tp = tcp_close(tp);
-			ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset(m, tp, th, tlen);
 			BBR_STAT_INC(bbr_dropped_af_data);
 			return (1);
 		}
@@ -8763,7 +8763,7 @@ bbr_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
 	    SEQ_GT(th->th_ack, tp->snd_max))) {
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset(m, tp, th, tlen);
 		return (1);
 	}
 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
@@ -8965,7 +8965,7 @@ bbr_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
 	     SEQ_GT(th->th_ack, tp->snd_max))) {
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset(m, tp, th, tlen);
 		return (1);
 	}
 	if (tp->t_flags & TF_FASTOPEN) {
@@ -8977,7 +8977,7 @@ bbr_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		 */
 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-			ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset(m, tp, th, tlen);
 			return (1);
 		} else if (thflags & TH_SYN) {
 			/* non-initial SYN is ignored */
@@ -9010,7 +9010,7 @@ bbr_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	 */
 	if (SEQ_LT(th->th_seq, tp->irs)) {
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset(m, tp, th, tlen);
 		return (1);
 	}
 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
@@ -9288,7 +9288,7 @@ bbr_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	if (sbavail(&so->so_snd)) {
 		if (ctf_progress_timeout_check(tp, true)) {
 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -9385,7 +9385,7 @@ bbr_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	if (sbavail(&so->so_snd)) {
 		if (ctf_progress_timeout_check(tp, true)) {
 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -9405,7 +9405,7 @@ close_now:
 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
 		tp = tcp_close(tp);
 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, (*tlen));
+		ctf_do_dropwithreset(m, tp, th, *tlen);
 		return (1);
 	}
 	if (sbavail(&so->so_snd) == 0)
@@ -9535,7 +9535,7 @@ bbr_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	if (sbavail(&so->so_snd)) {
 		if (ctf_progress_timeout_check(tp, true)) {
 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -9637,7 +9637,7 @@ bbr_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	if (sbavail(&so->so_snd)) {
 		if (ctf_progress_timeout_check(tp, true)) {
 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -9739,7 +9739,7 @@ bbr_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	if (sbavail(&so->so_snd)) {
 		if (ctf_progress_timeout_check(tp, true)) {
 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -9848,7 +9848,7 @@ bbr_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	if (sbavail(&so->so_snd)) {
 		if (ctf_progress_timeout_check(tp, true)) {
 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -11510,7 +11510,7 @@ bbr_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-		ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset_conn(m, tp, th, tlen);
 		return (1);
 	}
 	if (tiwin > bbr->r_ctl.rc_high_rwnd)

sys/netinet/tcp_stacks/rack.c

@@ -12038,7 +12038,7 @@ rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
 			/* tcp_close will kill the inp pre-log the Reset */
 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
 			tp = tcp_close(tp);
-			ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -12876,7 +12876,7 @@ rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
 	    SEQ_GT(th->th_ack, tp->snd_max))) {
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset(m, tp, th, tlen);
 		return (1);
 	}
 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
@@ -13090,7 +13090,7 @@ rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
 	    SEQ_GT(th->th_ack, tp->snd_max))) {
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset(m, tp, th, tlen);
 		return (1);
 	}
 	if (tp->t_flags & TF_FASTOPEN) {
@@ -13103,7 +13103,7 @@ rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		 */
 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-			ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset(m, tp, th, tlen);
 			return (1);
 		} else if (thflags & TH_SYN) {
 			/* non-initial SYN is ignored */
@@ -13137,7 +13137,7 @@ rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	 */
 	if (SEQ_LT(th->th_seq, tp->irs)) {
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset(m, tp, th, tlen);
 		return (1);
 	}
 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
@@ -13400,7 +13400,7 @@ rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	if (sbavail(&so->so_snd)) {
 		if (ctf_progress_timeout_check(tp, true)) {
 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -13496,7 +13496,7 @@ rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		if (ctf_progress_timeout_check(tp, true)) {
 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
 						tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -13518,7 +13518,7 @@ rack_check_data_after_close(struct mbuf *m,
 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
 		tp = tcp_close(tp);
 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, (*tlen));
+		ctf_do_dropwithreset(m, tp, th, *tlen);
 		return (1);
 	}
 	if (sbavail(&so->so_snd) == 0)
@@ -13646,7 +13646,7 @@ rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		if (ctf_progress_timeout_check(tp, true)) {
 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
 						tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -13747,7 +13747,7 @@ rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		if (ctf_progress_timeout_check(tp, true)) {
 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
 						tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -13849,7 +13849,7 @@ rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		if (ctf_progress_timeout_check(tp, true)) {
 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
 						tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -13953,7 +13953,7 @@ rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		if (ctf_progress_timeout_check(tp, true)) {
 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
 						tp, tick, PROGRESS_DROP, __LINE__);
-			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_TCP_RST, tlen);
+			ctf_do_dropwithreset_conn(m, tp, th, tlen);
 			return (1);
 		}
 	}
@@ -16653,7 +16653,7 @@ rack_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset(m, tp, th, tlen);
 #ifdef TCP_ACCOUNTING
 		sched_unpin();
 #endif

sys/netinet/tcp_stacks/rack_bbr_common.c

@@ -507,9 +507,9 @@ ctf_flight_size(struct tcpcb *tp, uint32_t rc_sacked)
 
 void
 ctf_do_dropwithreset(struct mbuf *m, struct tcpcb *tp, struct tcphdr *th,
-    int32_t rstreason, int32_t tlen)
+    int32_t tlen)
 {
-	tcp_dropwithreset(m, th, tp, tlen, rstreason);
+	tcp_dropwithreset(m, th, tp, tlen);
 	if (tp != NULL)
 		INP_WUNLOCK(tptoinpcb(tp));
 }
@@ -670,7 +670,7 @@ ctf_do_dropafterack(struct mbuf *m, struct tcpcb *tp, struct tcphdr *th, int32_t
 	    (SEQ_GT(tp->snd_una, th->th_ack) ||
 	    SEQ_GT(th->th_ack, tp->snd_max))) {
 		*ret_val = 1;
-		ctf_do_dropwithreset(m, tp, th, BANDLIM_TCP_RST, tlen);
+		ctf_do_dropwithreset(m, tp, th, tlen);
 		return;
 	} else
 		*ret_val = 0;
@@ -864,10 +864,10 @@ ctf_calc_rwin(struct socket *so, struct tcpcb *tp)
 
 void
 ctf_do_dropwithreset_conn(struct mbuf *m, struct tcpcb *tp, struct tcphdr *th,
-    int32_t rstreason, int32_t tlen)
+    int32_t tlen)
 {
 
-	tcp_dropwithreset(m, th, tp, tlen, rstreason);
+	tcp_dropwithreset(m, th, tp, tlen);
 	tp = tcp_drop(tp, ETIMEDOUT);
 	if (tp)
 		INP_WUNLOCK(tptoinpcb(tp));

sys/netinet/tcp_stacks/rack_bbr_common.h

@@ -101,7 +101,7 @@ ctf_do_dropafterack(struct mbuf *m, struct tcpcb *tp,
 
 void
 ctf_do_dropwithreset(struct mbuf *m, struct tcpcb *tp,
-	struct tcphdr *th, int32_t rstreason, int32_t tlen);
+	struct tcphdr *th, int32_t tlen);
 void
 ctf_do_drop(struct mbuf *m, struct tcpcb *tp);
 
@@ -125,7 +125,7 @@ ctf_calc_rwin(struct socket *so, struct tcpcb *tp);
 
 void
 ctf_do_dropwithreset_conn(struct mbuf *m, struct tcpcb *tp, struct tcphdr *th,
-    int32_t rstreason, int32_t tlen);
+    int32_t tlen);
 
 uint32_t
 ctf_fixed_maxseg(struct tcpcb *tp);

sys/netinet/tcp_var.h

@@ -1379,8 +1379,7 @@ int	 tcp_reass(struct tcpcb *, struct tcphdr *, tcp_seq *, int *,
 void	 tcp_reass_global_init(void);
 void	 tcp_reass_flush(struct tcpcb *);
 void	 tcp_dooptions(struct tcpopt *, u_char *, int, int);
-void	tcp_dropwithreset(struct mbuf *, struct tcphdr *,
-		     struct tcpcb *, int, int);
+void	 tcp_dropwithreset(struct mbuf *, struct tcphdr *, struct tcpcb *, int);
 void	tcp_pulloutofband(struct socket *,
 		     struct tcphdr *, struct mbuf *, int);
 void	tcp_xmit_timer(struct tcpcb *, int);