X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/473a17a5bf996b2f703cd226ca7ef88ac40bfcdb..4023eed27a3d5dfd1145560a2a8cc42880469c82:/usr/src/sys/netinet/tcp_input.c

diff --git a/usr/src/sys/netinet/tcp_input.c b/usr/src/sys/netinet/tcp_input.c
index a6a7867234..63ac1ba44b 100644
--- a/usr/src/sys/netinet/tcp_input.c
+++ b/usr/src/sys/netinet/tcp_input.c
@@ -1,4 +1,4 @@
-/*	tcp_input.c	1.51	82/01/25	*/
+/*	tcp_input.c	1.68	82/06/20	*/
 
 #include "../h/param.h"
 #include "../h/systm.h"
@@ -7,6 +7,7 @@
 #include "../h/socket.h"
 #include "../h/socketvar.h"
 #include "../net/in.h"
+#include "../net/route.h"
 #include "../net/in_pcb.h"
 #include "../net/in_systm.h"
 #include "../net/if.h"
@@ -45,8 +46,8 @@ tcp_input(m0)
 	struct socket *so;
 	int todrop, acked;
 	short ostate;
+	struct in_addr laddr;
 
-COUNT(TCP_INPUT);
 	/*
 	 * Get IP and TCP header together in first mbuf.
 	 * Note: IP leaves IP header in first mbuf.
@@ -72,12 +73,13 @@ COUNT(TCP_INPUT);
 		ti->ti_next = ti->ti_prev = 0;
 		ti->ti_x1 = 0;
 		ti->ti_len = (u_short)tlen;
-#if vax
-		ti->ti_len = htons(ti->ti_len);
+#if vax || pdp11
+		ti->ti_len = htons((u_short)ti->ti_len);
 #endif
 		if (ti->ti_sum = in_cksum(m, len)) {
 			tcpstat.tcps_badsum++;
-			printf("tcp cksum %x\n", ti->ti_sum);
+			if (tcpprintfs)
+				printf("tcp cksum %x\n", ti->ti_sum);
 			goto drop;
 		}
 	}
@@ -91,7 +93,8 @@ COUNT(TCP_INPUT);
 		tcpstat.tcps_badoff++;
 		goto drop;
 	}
-	ti->ti_len = tlen - off;
+	tlen -= off;
+	ti->ti_len = tlen;
 	if (off > sizeof (struct tcphdr)) {
 		if ((m = m_pullup(m, sizeof (struct ip) + off)) == 0) {
 			tcpstat.tcps_hdrops++;
@@ -104,14 +107,22 @@ COUNT(TCP_INPUT);
 		om->m_off = MMINOFF;
 		om->m_len = off - sizeof (struct tcphdr);
 		{ caddr_t op = mtod(m, caddr_t) + sizeof (struct tcpiphdr);
-		  bcopy(op, mtod(om, caddr_t), om->m_len);
+		  bcopy(op, mtod(om, caddr_t), (unsigned)om->m_len);
 		  m->m_len -= om->m_len;
-		  bcopy(op+om->m_len, op, m->m_len-sizeof (struct tcpiphdr));
+		  bcopy(op+om->m_len, op,
+		   (unsigned)(m->m_len-sizeof (struct tcpiphdr)));
 		}
 	}
 	tiflags = ti->ti_flags;
 
-#if vax
+	/*
+	 * Drop TCP and IP headers.
+	 */
+	off += sizeof (struct ip);
+	m->m_off += off;
+	m->m_len -= off;
+
+#if vax || pdp11
 	/*
 	 * Convert TCP protocol specific fields to host format.
 	 */
@@ -122,10 +133,12 @@ COUNT(TCP_INPUT);
 #endif
 
 	/*
-	 * Locate pcb for segment.
+	 * Locate pcb for segment.  On match, update the local
+	 * address stored in the block to reflect anchoring.
 	 */
 	inp = in_pcblookup
-		(&tcb, ti->ti_src, ti->ti_sport, ti->ti_dst, ti->ti_dport);
+		(&tcb, ti->ti_src, ti->ti_sport, ti->ti_dst, ti->ti_dport,
+		INPLOOKUP_WILDCARD);
 
 	/*
 	 * If the state is CLOSED (i.e., TCB does not exist) then
@@ -188,11 +201,18 @@ COUNT(TCP_INPUT);
 			goto drop;
 		tcp_in.sin_addr = ti->ti_src;
 		tcp_in.sin_port = ti->ti_sport;
-		if (in_pcbconnect(inp, (struct sockaddr *)&tcp_in))
+		laddr = inp->inp_laddr;
+		if (inp->inp_laddr.s_addr == 0)
+			inp->inp_laddr = ti->ti_dst;
+		if (in_pcbconnect(inp, (struct sockaddr_in *)&tcp_in)) {
+			inp->inp_laddr = laddr;
 			goto drop;
+		}
 		tp->t_template = tcp_template(tp);
 		if (tp->t_template == 0) {
 			in_pcbdisconnect(inp);
+			inp->inp_laddr = laddr;
+			tp = 0;
 			goto drop;
 		}
 		tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2;
@@ -222,8 +242,10 @@ COUNT(TCP_INPUT);
 		     SEQ_GT(ti->ti_ack, tp->snd_max)))
 			goto dropwithreset;
 		if (tiflags & TH_RST) {
-			if (tiflags & TH_ACK)
+			if (tiflags & TH_ACK) {
 				tcp_drop(tp, ECONNREFUSED);
+				tp = 0;
+			}
 			goto drop;
 		}
 		if ((tiflags & TH_SYN) == 0)
@@ -276,6 +298,7 @@ trimthenstep6:
 		if (tp->rcv_nxt != ti->ti_seq)
 			goto dropafterack;
 		if (ti->ti_len > 0) {
+			m_adj(m, ti->ti_len);
 			ti->ti_len = 0;
 			ti->ti_flags &= ~(TH_PUSH|TH_FIN);
 		}
@@ -284,10 +307,11 @@ trimthenstep6:
 		 * If segment begins before rcv_nxt, drop leading
 		 * data (and SYN); if nothing left, just ack.
 		 */
-		if (SEQ_GT(tp->rcv_nxt, ti->ti_seq)) {
-			todrop = tp->rcv_nxt - ti->ti_seq;
+		todrop = tp->rcv_nxt - ti->ti_seq;
+		if (todrop > 0) {
 			if (tiflags & TH_SYN) {
 				tiflags &= ~TH_SYN;
+				ti->ti_flags &= ~TH_SYN;
 				ti->ti_seq++;
 				if (ti->ti_urp > 1) 
 					ti->ti_urp--;
@@ -295,7 +319,8 @@ trimthenstep6:
 					tiflags &= ~TH_URG;
 				todrop--;
 			}
-			if (todrop > ti->ti_len)
+			if (todrop > ti->ti_len ||
+			    todrop == ti->ti_len && (tiflags&TH_FIN) == 0)
 				goto dropafterack;
 			m_adj(m, todrop);
 			ti->ti_seq += todrop;
@@ -304,20 +329,17 @@ trimthenstep6:
 				ti->ti_urp -= todrop;
 			else {
 				tiflags &= ~TH_URG;
-				/* ti->ti_flags &= ~TH_URG; */
-				/* ti->ti_urp = 0; */
+				ti->ti_flags &= ~TH_URG;
+				ti->ti_urp = 0;
 			}
-			/* tiflags &= ~TH_SYN; */
-			/* ti->ti_flags &= ~TH_SYN; */
 		}
 		/*
 		 * If segment ends after window, drop trailing data
 		 * (and PUSH and FIN); if nothing left, just ACK.
 		 */
-		if (SEQ_GT(ti->ti_seq+ti->ti_len, tp->rcv_nxt+tp->rcv_wnd)) {
-			todrop =
-			     ti->ti_seq+ti->ti_len - (tp->rcv_nxt+tp->rcv_wnd);
-			if (todrop > ti->ti_len)
+		todrop = (ti->ti_seq+ti->ti_len) - (tp->rcv_nxt+tp->rcv_wnd);
+		if (todrop > 0) {
+			if (todrop >= ti->ti_len)
 				goto dropafterack;
 			m_adj(m, -todrop);
 			ti->ti_len -= todrop;
@@ -325,6 +347,16 @@ trimthenstep6:
 		}
 	}
 
+	/*
+	 * If a segment is received on a connection after the
+	 * user processes are gone, then RST the other end.
+	 */
+	if (so->so_state & SS_USERGONE) {
+		tcp_close(tp);
+		tp = 0;
+		goto dropwithreset;
+	}
+
 	/*
 	 * If the RST bit is set examine the state:
 	 *    SYN_RECEIVED STATE:
@@ -345,9 +377,14 @@ trimthenstep6:
 			inp->inp_ppcb = 0;
 			tp = tcp_newtcpcb(inp);
 			tp->t_state = TCPS_LISTEN;
+			inp->inp_faddr.s_addr = 0;
+			inp->inp_fport = 0;
+			inp->inp_laddr.s_addr = 0;	/* not quite right */
+			tp = 0;
 			goto drop;
 		}
 		tcp_drop(tp, ECONNREFUSED);
+		tp = 0;
 		goto drop;
 
 	case TCPS_ESTABLISHED:
@@ -355,12 +392,14 @@ trimthenstep6:
 	case TCPS_FIN_WAIT_2:
 	case TCPS_CLOSE_WAIT:
 		tcp_drop(tp, ECONNRESET);
+		tp = 0;
 		goto drop;
 
 	case TCPS_CLOSING:
 	case TCPS_LAST_ACK:
 	case TCPS_TIME_WAIT:
 		tcp_close(tp);
+		tp = 0;
 		goto drop;
 	}
 
@@ -370,6 +409,7 @@ trimthenstep6:
 	 */
 	if (tiflags & TH_SYN) {
 		tcp_drop(tp, ECONNRESET);
+		tp = 0;
 		goto dropwithreset;
 	}
 
@@ -427,42 +467,44 @@ trimthenstep6:
 		if (SEQ_GT(ti->ti_ack, tp->snd_max))
 			goto dropafterack;
 		acked = ti->ti_ack - tp->snd_una;
+
+		/*
+		 * If transmit timer is running and timed sequence
+		 * number was acked, update smoothed round trip time.
+		 */
+		if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq)) {
+			if (tp->t_srtt == 0)
+				tp->t_srtt = tp->t_rtt;
+			else
+				tp->t_srtt =
+				    tcp_alpha * tp->t_srtt +
+				    (1 - tcp_alpha) * tp->t_rtt;
+/* printf("rtt %d srtt*100 now %d\n", tp->t_rtt, (int)(tp->t_srtt*100)); */
+			tp->t_rtt = 0;
+		}
+
 		if (ti->ti_ack == tp->snd_max)
 			tp->t_timer[TCPT_REXMT] = 0;
 		else {
 			TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
 			    tcp_beta * tp->t_srtt, TCPTV_MIN, TCPTV_MAX);
-			tp->t_rtt = 0;
+			tp->t_rtt = 1;
 			tp->t_rxtshift = 0;
 		}
 		if (acked > so->so_snd.sb_cc) {
 			sbdrop(&so->so_snd, so->so_snd.sb_cc);
 			tp->snd_wnd -= so->so_snd.sb_cc;
 		} else {
-			sbdrop(&so->so_snd.sb_cc, acked);
+			sbdrop(&so->so_snd, acked);
 			tp->snd_wnd -= acked;
 			acked = 0;
 		}
-		if (so->so_snd.sb_flags & SB_WAIT)
+		if ((so->so_snd.sb_flags & SB_WAIT) || so->so_snd.sb_sel)
 			sowwakeup(so);
 		tp->snd_una = ti->ti_ack;
 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
 			tp->snd_nxt = tp->snd_una;
 
-		/*
-		 * If transmit timer is running and timed sequence
-		 * number was acked, update smoothed round trip time.
-		 */
-		if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq)) {
-			if (tp->t_srtt == 0)
-				tp->t_srtt = tp->t_rtt;
-			else
-				tp->t_srtt =
-				    tcp_alpha * tp->t_srtt +
-				    (1 - tcp_alpha) * tp->t_rtt;
-			tp->t_rtt = 0;
-		}
-
 		switch (tp->t_state) {
 
 		/*
@@ -471,8 +513,15 @@ trimthenstep6:
 		 * then enter FIN_WAIT_2.
 		 */
 		case TCPS_FIN_WAIT_1:
-			if (ourfinisacked)
+			if (ourfinisacked) {
+				/*
+				 * If we can't receive any more
+				 * data, then closing user can proceed.
+				 */
+				if (so->so_state & SS_CANTRCVMORE)
+					soisdisconnected(so);
 				tp->t_state = TCPS_FIN_WAIT_2;
+			}
 			break;
 
 	 	/*
@@ -497,8 +546,10 @@ trimthenstep6:
 		 * and return.
 		 */
 		case TCPS_LAST_ACK:
-			if (ourfinisacked)
+			if (ourfinisacked) {
 				tcp_close(tp);
+				tp = 0;
+			}
 			goto drop;
 
 		/*
@@ -520,9 +571,6 @@ step6:
 	if (SEQ_LT(tp->snd_wl1, ti->ti_seq) || tp->snd_wl1 == ti->ti_seq &&
 	    (SEQ_LT(tp->snd_wl2, ti->ti_ack) ||
 	     tp->snd_wl2 == ti->ti_ack && ti->ti_win > tp->snd_wnd)) {
-/*
-printf("wl1 %x seq %x wl2 %x ack %x win %x wnd %x\n", tp->snd_wl1, ti->ti_seq, tp->snd_wl2, ti->ti_ack, ti->ti_win, tp->snd_wnd);
-*/
 		tp->snd_wnd = ti->ti_win;
 		tp->snd_wl1 = ti->ti_seq;
 		tp->snd_wl2 = ti->ti_ack;
@@ -574,9 +622,6 @@ printf("wl1 %x seq %x wl2 %x ack %x win %x wnd %x\n", tp->snd_wl1, ti->ti_seq, t
 	 */
 	if ((ti->ti_len || (tiflags&TH_FIN)) &&
 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
-		off += sizeof (struct ip);		/* drop IP header */
-		m->m_off += off;
-		m->m_len -= off;
 		tiflags = tcp_reass(tp, ti);
 		if (tcpnodelack == 0)
 			tp->t_flags |= TF_DELACK;
@@ -642,22 +687,25 @@ printf("wl1 %x seq %x wl2 %x ack %x win %x wnd %x\n", tp->snd_wl1, ti->ti_seq, t
 	/*
 	 * Return any desired output.
 	 */
-	tcp_output(tp);
+	(void) tcp_output(tp);
 	return;
 
 dropafterack:
 	/*
-	 * Generate an ACK dropping incoming segment.
-	 * Make ACK reflect our state.
+	 * Generate an ACK dropping incoming segment if it occupies
+	 * sequence space, where the ACK reflects our state.
 	 */
-	if (tiflags & TH_RST)
+	if ((tiflags&TH_RST) ||
+	    tlen == 0 && (tiflags&(TH_SYN|TH_FIN)) == 0)
 		goto drop;
+	if (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
+		tcp_trace(TA_RESPOND, ostate, tp, &tcp_saveti, 0);
 	tcp_respond(tp, ti, tp->rcv_nxt, tp->snd_nxt, TH_ACK);
 	return;
 
 dropwithreset:
 	if (om)
-		m_free(om);
+		(void) m_free(om);
 	/*
 	 * Generate a RST, dropping incoming segment.
 	 * Make ACK acceptable to originator of segment.
@@ -669,7 +717,8 @@ dropwithreset:
 	else {
 		if (tiflags & TH_SYN)
 			ti->ti_len++;
-		tcp_respond(tp, ti, ti->ti_seq+ti->ti_len, (tcp_seq)0, TH_RST|TH_ACK);
+		tcp_respond(tp, ti, ti->ti_seq+ti->ti_len, (tcp_seq)0,
+		    TH_RST|TH_ACK);
 	}
 	return;
 
@@ -677,6 +726,8 @@ drop:
 	/*
 	 * Drop space held by incoming segment and return.
 	 */
+	if (tp && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
+		tcp_trace(TA_DROP, ostate, tp, &tcp_saveti, 0);
 	m_freem(m);
 	return;
 }
@@ -707,8 +758,8 @@ tcp_dooptions(tp, om)
 			if (optlen != 4)
 				continue;
 			tp->t_maxseg = *(u_short *)(cp + 2);
-#if vax
-			tp->t_maxseg = ntohs(tp->t_maxseg);
+#if vax || pdp11
+			tp->t_maxseg = ntohs((u_short)tp->t_maxseg);
 #endif
 			break;
 			
@@ -737,7 +788,7 @@ printf("bad seq\n");
 			tp->t_iobseq = cp[2];
 			tp->t_iobc = cp[3];
 			mark = *(tcp_seq *)(cp + 4);
-#if vax
+#if vax || pdp11
 			mark = ntohl(mark);
 #endif
 			so->so_oobmark = so->so_rcv.sb_cc + (mark-tp->rcv_nxt);
@@ -765,7 +816,7 @@ printf("take oob ack %x and cancel rexmt\n", cp[2]);
 #endif TCPTRUEOOB
 		}
 	}
-	m_free(om);
+	(void) m_free(om);
 }
 
 /*
@@ -779,7 +830,7 @@ tcp_pulloutofband(so, ti)
 	struct tcpiphdr *ti;
 {
 	register struct mbuf *m;
-	int cnt = sizeof (struct tcpiphdr) + ti->ti_urp - 1;
+	int cnt = ti->ti_urp - 1;
 	
 	m = dtom(ti);
 	while (cnt >= 0) {
@@ -789,7 +840,7 @@ tcp_pulloutofband(so, ti)
 
 			tp->t_iobc = *cp;
 			tp->t_oobflags |= TCPOOB_HAVEDATA;
-			bcopy(cp+1, cp, m->m_len - cnt - 1);
+			bcopy(cp+1, cp, (unsigned)(m->m_len - cnt - 1));
 			m->m_len--;
 			return;
 		}
@@ -814,7 +865,6 @@ tcp_reass(tp, ti)
 	struct socket *so = tp->t_inpcb->inp_socket;
 	struct mbuf *m;
 	int flags;
-COUNT(TCP_REASS);
 
 	/*
 	 * Call with ti==0 after become established to
@@ -838,7 +888,7 @@ COUNT(TCP_REASS);
 	 */
 	if ((struct tcpiphdr *)q->ti_prev != (struct tcpiphdr *)tp) {
 		register int i;
-		q = (struct tcpiphdr *)(q->ti_prev);
+		q = (struct tcpiphdr *)q->ti_prev;
 		/* conversion to int (in i) handles seq wraparound */
 		i = q->ti_seq + q->ti_len - ti->ti_seq;
 		if (i > 0) {
@@ -855,10 +905,12 @@ COUNT(TCP_REASS);
 	 * While we overlap succeeding segments trim them or,
 	 * if they are completely covered, dequeue them.
 	 */
-	while (q != (struct tcpiphdr *)tp &&
-	    SEQ_GT(ti->ti_seq + ti->ti_len, q->ti_seq)) {
+	while (q != (struct tcpiphdr *)tp) {
 		register int i = (ti->ti_seq + ti->ti_len) - q->ti_seq;
+		if (i <= 0)
+			break;
 		if (i < q->ti_len) {
+			q->ti_seq += i;
 			q->ti_len -= i;
 			m_adj(dtom(q), i);
 			break;
@@ -893,7 +945,7 @@ present:
 		m = dtom(ti);
 		ti = (struct tcpiphdr *)ti->ti_next;
 		if (so->so_state & SS_CANTRCVMORE)
-			(void) m_freem(m);
+			m_freem(m);
 		else
 			sbappend(&so->so_rcv, m);
 	} while (ti != (struct tcpiphdr *)tp && ti->ti_seq == tp->rcv_nxt);