-/* tcp_input.c 1.36 81/12/07 */
+/* tcp_input.c 1.68 82/06/20 */
#include "../h/param.h"
#include "../h/systm.h"
#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"
#include "../net/tcp_timer.h"
#include "../net/tcp_var.h"
#include "../net/tcpip.h"
+#include "../net/tcp_debug.h"
#include "../errno.h"
+int tcpprintfs = 0;
int tcpcksum = 1;
+struct sockaddr_in tcp_in = { AF_INET };
+struct tcpiphdr tcp_saveti;
+extern tcpnodelack;
+struct tcpcb *tcp_newtcpcb();
/*
* TCP input routine, follows pages 65-76 of the
* protocol specification dated September, 1981 very closely.
register struct tcpiphdr *ti;
struct inpcb *inp;
register struct mbuf *m;
+ struct mbuf *om = 0;
int len, tlen, off;
- register struct tcpcb *tp;
+ register struct tcpcb *tp = 0;
register int tiflags;
struct socket *so;
int todrop, acked;
+ short ostate;
+ struct in_addr laddr;
-COUNT(TCP_INPUT);
/*
- * Get ip and tcp header together in first mbuf.
+ * Get IP and TCP header together in first mbuf.
+ * Note: IP leaves IP header in first mbuf.
*/
m = m0;
ti = mtod(m, struct tcpiphdr *);
- if (ti->ti_len > sizeof (struct ip))
+ if (((struct ip *)ti)->ip_hl > (sizeof (struct ip) >> 2))
ip_stripoptions((struct ip *)ti, (struct mbuf *)0);
- if (m->m_len < sizeof (struct tcpiphdr)) {
- if (m_pullup(m, sizeof (struct tcpiphdr)) == 0) {
+ if (m->m_off > MMAXOFF || m->m_len < sizeof (struct tcpiphdr)) {
+ if ((m = m_pullup(m, sizeof (struct tcpiphdr))) == 0) {
tcpstat.tcps_hdrops++;
- goto drop;
+ return;
}
ti = mtod(m, struct tcpiphdr *);
}
/*
- * Checksum extended tcp header and data.
+ * Checksum extended TCP header and data.
*/
tlen = ((struct ip *)ti)->ip_len;
len = sizeof (struct ip) + tlen;
if (tcpcksum) {
ti->ti_next = ti->ti_prev = 0;
ti->ti_x1 = 0;
- ti->ti_len = htons((u_short)tlen);
- if ((ti->ti_sum = in_cksum(m, len)) != 0xffff) {
+ ti->ti_len = (u_short)tlen;
+#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;
}
}
/*
- * Check that tcp offset makes sense,
- * process tcp options and adjust length.
+ * Check that TCP offset makes sense,
+ * pull out TCP options and adjust length.
*/
off = ti->ti_off << 2;
- if (off < sizeof (struct tcphdr) || off > ti->ti_len) {
+ if (off < sizeof (struct tcphdr) || off > tlen) {
tcpstat.tcps_badoff++;
goto drop;
}
- ti->ti_len = tlen - off;
-#if 0
- if (off > sizeof (struct tcphdr) >> 2)
- tcp_options(ti);
-#endif
+ tlen -= off;
+ ti->ti_len = tlen;
+ if (off > sizeof (struct tcphdr)) {
+ if ((m = m_pullup(m, sizeof (struct ip) + off)) == 0) {
+ tcpstat.tcps_hdrops++;
+ goto drop;
+ }
+ ti = mtod(m, struct tcpiphdr *);
+ om = m_get(M_DONTWAIT);
+ if (om == 0)
+ goto drop;
+ 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), (unsigned)om->m_len);
+ m->m_len -= om->m_len;
+ bcopy(op+om->m_len, op,
+ (unsigned)(m->m_len-sizeof (struct tcpiphdr)));
+ }
+ }
tiflags = ti->ti_flags;
/*
- * Convert tcp protocol specific fields to host format.
+ * 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.
*/
ti->ti_seq = ntohl(ti->ti_seq);
ti->ti_ack = ntohl(ti->ti_ack);
ti->ti_win = ntohs(ti->ti_win);
ti->ti_urp = ntohs(ti->ti_urp);
+#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
- * all data in the incoming segment is discarded. (p. 65).
+ * all data in the incoming segment is discarded.
*/
if (inp == 0)
goto dropwithreset;
if (tp == 0)
goto dropwithreset;
so = inp->inp_socket;
+ if (so->so_options & SO_DEBUG) {
+ ostate = tp->t_state;
+ tcp_saveti = *ti;
+ }
/*
* Segment received on connection.
tp->t_idle = 0;
tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
+ /*
+ * Process options.
+ */
+ if (om) {
+ tcp_dooptions(tp, om);
+ om = 0;
+ }
+
/*
* Calculate amount of space in receive window,
* and then do TCP input processing.
*/
tp->rcv_wnd = sbspace(&so->so_rcv);
+ if (tp->rcv_wnd < 0)
+ tp->rcv_wnd = 0;
switch (tp->t_state) {
* Also initialize tp->snd_nxt to tp->iss+1 and tp->snd_una to tp->iss.
* Fill in remote peer address fields if not previously specified.
* Enter SYN_RECEIVED state, and process any other fields of this
- * segment in this state. (p. 65)
+ * segment in this state.
*/
case TCPS_LISTEN:
if (tiflags & TH_RST)
goto dropwithreset;
if ((tiflags & TH_SYN) == 0)
goto drop;
+ tcp_in.sin_addr = ti->ti_src;
+ tcp_in.sin_port = ti->ti_sport;
+ 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;
tp->irs = ti->ti_seq;
tcp_sendseqinit(tp);
tcp_rcvseqinit(tp);
tp->t_state = TCPS_SYN_RECEIVED;
- if (inp->inp_faddr.s_addr == 0) {
- inp->inp_faddr = ti->ti_src;
- inp->inp_fport = ti->ti_sport;
- }
+ tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
goto trimthenstep6;
/*
*/
case TCPS_SYN_SENT:
if ((tiflags & TH_ACK) &&
- (SEQ_LEQ(ti->ti_ack, tp->iss) ||
- SEQ_GT(ti->ti_ack, tp->snd_nxt)))
+/* this should be SEQ_LT; is SEQ_LEQ for BBN vax TCP only */
+ (SEQ_LT(ti->ti_ack, tp->iss) ||
+ SEQ_GT(ti->ti_ack, tp->snd_max)))
goto dropwithreset;
if (tiflags & TH_RST) {
- if (tiflags & TH_ACK)
- tcp_drop(tp, ECONNRESET);
+ if (tiflags & TH_ACK) {
+ tcp_drop(tp, ECONNREFUSED);
+ tp = 0;
+ }
goto drop;
}
if ((tiflags & TH_SYN) == 0)
goto drop;
- tp->iss = ti->ti_ack;
- tcp_sendseqinit(tp);
+ tp->snd_una = ti->ti_ack;
+ if (SEQ_LT(tp->snd_nxt, tp->snd_una))
+ tp->snd_nxt = tp->snd_una;
+ tp->t_timer[TCPT_REXMT] = 0;
tp->irs = ti->ti_seq;
tcp_rcvseqinit(tp);
tp->t_flags |= TF_ACKNOW;
if (SEQ_GT(tp->snd_una, tp->iss)) {
+ if (so->so_options & SO_ACCEPTCONN)
+ so->so_state |= SS_CONNAWAITING;
+ soisconnected(so);
tp->t_state = TCPS_ESTABLISHED;
(void) tcp_reass(tp, (struct tcpiphdr *)0);
} else
trimthenstep6:
/*
- * If had syn, advance ti->ti_seq to correspond
- * to first data byte.
- */
- if (tiflags & TH_SYN)
- ti->ti_seq++;
-
- /*
+ * Advance ti->ti_seq to correspond to first data byte.
* If data, trim to stay within window,
* dropping FIN if necessary.
*/
+ ti->ti_seq++;
if (ti->ti_len > tp->rcv_wnd) {
todrop = ti->ti_len - tp->rcv_wnd;
m_adj(m, -todrop);
ti->ti_len = tp->rcv_wnd;
ti->ti_flags &= ~TH_FIN;
}
+ tp->snd_wl1 = ti->ti_seq - 1;
goto step6;
}
if (tp->rcv_wnd == 0) {
/*
* If window is closed can only take segments at
- * window edge, and have to drop data and EOL from
+ * window edge, and have to drop data and PUSH from
* incoming segments.
*/
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);
}
} else {
/*
- * If segment begins before rcv_next, drop leading
+ * 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--;
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;
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;
}
}
+ /*
+ * 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:
* Close the tcb.
*/
if (tiflags&TH_RST) switch (tp->t_state) {
-
+
case TCPS_SYN_RECEIVED:
if (inp->inp_socket->so_options & SO_ACCEPTCONN) {
+ /* a miniature tcp_close, but invisible to user */
+ (void) m_free(dtom(tp->t_template));
+ (void) m_free(dtom(tp));
+ 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:
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;
}
* error and we send an RST and drop the connection.
*/
if (tiflags & TH_SYN) {
- tcp_drop(tp, ECONNABORTED);
+ tcp_drop(tp, ECONNRESET);
+ tp = 0;
goto dropwithreset;
}
*/
case TCPS_SYN_RECEIVED:
if (SEQ_GT(tp->snd_una, ti->ti_ack) ||
- SEQ_GT(ti->ti_ack, tp->snd_nxt))
+ SEQ_GT(ti->ti_ack, tp->snd_max))
goto dropwithreset;
+ tp->snd_una++; /* SYN acked */
+ if (SEQ_LT(tp->snd_nxt, tp->snd_una))
+ tp->snd_nxt = tp->snd_una;
+ tp->t_timer[TCPT_REXMT] = 0;
+ if (so->so_options & SO_ACCEPTCONN)
+ so->so_state |= SS_CONNAWAITING;
soisconnected(so);
tp->t_state = TCPS_ESTABLISHED;
(void) tcp_reass(tp, (struct tcpiphdr *)0);
+ tp->snd_wl1 = ti->ti_seq - 1;
/* fall into ... */
/*
* In ESTABLISHED state: drop duplicate ACKs; ACK out of range
* ACKs. If the ack is in the range
- * tp->snd_una < ti->ti_ack <= tp->snd_nxt
+ * tp->snd_una < ti->ti_ack <= tp->snd_max
* then advance tp->snd_una to ti->ti_ack and drop
* data from the retransmission queue. If this ACK reflects
* more up to date window information we update our window information.
case TCPS_FIN_WAIT_2:
case TCPS_CLOSE_WAIT:
case TCPS_CLOSING:
+ case TCPS_LAST_ACK:
+ case TCPS_TIME_WAIT:
#define ourfinisacked (acked > 0)
- if (SEQ_LT(ti->ti_ack, tp->snd_una))
+ if (SEQ_LEQ(ti->ti_ack, tp->snd_una))
break;
- if (SEQ_GT(ti->ti_ack, tp->snd_nxt))
+ if (SEQ_GT(ti->ti_ack, tp->snd_max))
goto dropafterack;
acked = ti->ti_ack - tp->snd_una;
- if (acked > so->so_snd.sb_cc) {
- sbflush(&so->so_snd);
- acked -= so->so_snd.sb_cc;
- /* if acked our FIN is acked */
- } else {
- sbdrop(&so->so_snd, acked);
- acked = 0;
- }
/*
* 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)) {
- tp->t_srtt =
- tcp_beta * tp->t_srtt +
- (1 - tcp_beta) * tp->t_rtt;
+ 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;
}
- tp->snd_una = ti->ti_ack;
-
- /*
- * Update window information.
- */
- if (SEQ_LT(tp->snd_wl1, ti->ti_seq) ||
- tp->snd_wl1==ti->ti_seq && SEQ_LEQ(tp->snd_wl2,ti->ti_seq)) {
- tp->snd_wnd = ti->ti_win;
- tp->snd_wl1 = ti->ti_seq;
- tp->snd_wl2 = ti->ti_ack;
+ 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 = 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, acked);
+ tp->snd_wnd -= acked;
+ acked = 0;
}
+ 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;
switch (tp->t_state) {
* 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;
/*
* the segment.
*/
case TCPS_CLOSING:
- if (ourfinisacked)
+ if (ourfinisacked) {
tp->t_state = TCPS_TIME_WAIT;
- goto drop;
+ tcp_canceltimers(tp);
+ tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
+ soisdisconnected(so);
+ }
+ break;
/*
* The only thing that can arrive in LAST_ACK state
* and return.
*/
case TCPS_LAST_ACK:
- if (ourfinisacked)
+ if (ourfinisacked) {
tcp_close(tp);
+ tp = 0;
+ }
goto drop;
/*
step6:
/*
- * If an URG bit is set in the segment and is greater than the
- * current known urgent pointer, then signal the user that the
- * remote side has urgent data. This should not happen
- * in CLOSE_WAIT, CLOSING, LAST-ACK or TIME_WAIT STATES since
- * a FIN has been received from the remote side. In these states
- * we ignore the URG.
- */
- if ((tiflags & TH_URG) == 0 && TCPS_HAVERCVDFIN(tp->t_state) == 0)
- if (SEQ_GT(ti->ti_urp, tp->rcv_up)) {
- tp->rcv_up = ti->ti_urp;
-#if 0
- soisurgendata(so); /* XXX */
+ * Update window information.
+ */
+ 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)) {
+ tp->snd_wnd = ti->ti_win;
+ tp->snd_wl1 = ti->ti_seq;
+ tp->snd_wl2 = ti->ti_ack;
+ if (tp->snd_wnd > 0)
+ tp->t_timer[TCPT_PERSIST] = 0;
+ }
+
+ /*
+ * Process segments with URG.
+ */
+ if ((tiflags & TH_URG) && TCPS_HAVERCVDFIN(tp->t_state) == 0) {
+ /*
+ * If this segment advances the known urgent pointer,
+ * then mark the data stream. This should not happen
+ * in CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since
+ * a FIN has been received from the remote side.
+ * In these states we ignore the URG.
+ */
+ if (SEQ_GT(ti->ti_seq+ti->ti_urp, tp->rcv_up)) {
+ tp->rcv_up = ti->ti_seq + ti->ti_urp;
+ so->so_oobmark = so->so_rcv.sb_cc +
+ (tp->rcv_up - tp->rcv_nxt) - 1;
+ if (so->so_oobmark == 0)
+ so->so_state |= SS_RCVATMARK;
+#ifdef TCPTRUEOOB
+ if ((tp->t_flags & TF_DOOOB) == 0)
#endif
+ sohasoutofband(so);
+ tp->t_oobflags &= ~TCPOOB_HAVEDATA;
}
+ /*
+ * Remove out of band data so doesn't get presented to user.
+ * This can happen independent of advancing the URG pointer,
+ * but if two URG's are pending at once, some out-of-band
+ * data may creep in... ick.
+ */
+ if (ti->ti_urp <= ti->ti_len) {
+ tcp_pulloutofband(so, ti);
+ }
+ }
/*
* Process the segment text, merging it into the TCP sequencing queue,
* case PRU_RCVD). If a FIN has already been received on this
* connection then we just ignore the text.
*/
- if (ti->ti_len) {
- if (TCPS_HAVERCVDFIN(tp->t_state))
- goto drop;
- off += sizeof (struct ip); /* drop IP header */
- m->m_off += off;
- m->m_len -= off;
+ if ((ti->ti_len || (tiflags&TH_FIN)) &&
+ TCPS_HAVERCVDFIN(tp->t_state) == 0) {
tiflags = tcp_reass(tp, ti);
- tp->t_flags |= TF_ACKNOW; /* XXX TF_DELACK */
- } else
+ if (tcpnodelack == 0)
+ tp->t_flags |= TF_DELACK;
+ else
+ tp->t_flags |= TF_ACKNOW;
+ } else {
m_freem(m);
+ tiflags &= ~TH_FIN;
+ }
/*
- * If FIN is received then if we haven't received SYN and
- * therefore can't validate drop the segment. Otherwise ACK
- * the FIN and let the user know that the connection is closing.
+ * If FIN is received ACK the FIN and let the user know
+ * that the connection is closing.
*/
- if ((tiflags & TH_FIN)) {
- if (TCPS_HAVERCVDSYN(tp->t_state) == 0)
- goto drop;
- socantrcvmore(so);
- tp->t_flags |= TF_ACKNOW;
- tp->rcv_nxt++;
+ if (tiflags & TH_FIN) {
+ if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
+ socantrcvmore(so);
+ tp->t_flags |= TF_ACKNOW;
+ tp->rcv_nxt++;
+ }
switch (tp->t_state) {
/*
* standard timers.
*/
case TCPS_FIN_WAIT_2:
- tp->t_state = TCPS_TIME_WAIT;;
+ tp->t_state = TCPS_TIME_WAIT;
tcp_canceltimers(tp);
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
+ soisdisconnected(so);
break;
/*
break;
}
}
+ if (so->so_options & SO_DEBUG)
+ tcp_trace(TA_INPUT, ostate, tp, &tcp_saveti, 0);
/*
* Return any desired output.
*/
- tcp_output(tp);
+ (void) tcp_output(tp);
return;
dropafterack:
/*
- * Generate an ACK, then drop 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;
- tcp_respond(ti, tp->rcv_nxt, tp->snd_nxt, TH_ACK);
- 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)
+ (void) m_free(om);
/*
- * Generate a RST, then drop incoming segment.
+ * Generate a RST, dropping incoming segment.
* Make ACK acceptable to originator of segment.
*/
if (tiflags & TH_RST)
goto drop;
if (tiflags & TH_ACK)
- tcp_respond(ti, (tcp_seq)0, ti->ti_ack, TH_RST);
+ tcp_respond(tp, ti, (tcp_seq)0, ti->ti_ack, TH_RST);
else {
if (tiflags & TH_SYN)
ti->ti_len++;
- tcp_respond(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);
}
- goto drop;
+ return;
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;
+}
+
+tcp_dooptions(tp, om)
+ struct tcpcb *tp;
+ struct mbuf *om;
+{
+ register u_char *cp;
+ int opt, optlen, cnt;
+
+ cp = mtod(om, u_char *);
+ cnt = om->m_len;
+ for (; cnt > 0; cnt -= optlen, cp += optlen) {
+ opt = cp[0];
+ if (opt == TCPOPT_EOL)
+ break;
+ if (opt == TCPOPT_NOP)
+ optlen = 1;
+ else
+ optlen = cp[1];
+ switch (opt) {
+
+ default:
+ break;
+
+ case TCPOPT_MAXSEG:
+ if (optlen != 4)
+ continue;
+ tp->t_maxseg = *(u_short *)(cp + 2);
+#if vax || pdp11
+ tp->t_maxseg = ntohs((u_short)tp->t_maxseg);
+#endif
+ break;
+
+#ifdef TCPTRUEOOB
+ case TCPOPT_WILLOOB:
+ tp->t_flags |= TF_DOOOB;
+printf("tp %x dooob\n", tp);
+ break;
+
+ case TCPOPT_OOBDATA: {
+ int seq;
+ register struct socket *so = tp->t_inpcb->inp_socket;
+ tcp_seq mark;
+
+ if (optlen != 8)
+ continue;
+ seq = cp[2];
+ if (seq < tp->t_iobseq)
+ seq += 256;
+printf("oobdata cp[2] %d iobseq %d seq %d\n", cp[2], tp->t_iobseq, seq);
+ if (seq - tp->t_iobseq > 128) {
+printf("bad seq\n");
+ tp->t_oobflags |= TCPOOB_OWEACK;
+ break;
+ }
+ tp->t_iobseq = cp[2];
+ tp->t_iobc = cp[3];
+ mark = *(tcp_seq *)(cp + 4);
+#if vax || pdp11
+ mark = ntohl(mark);
+#endif
+ so->so_oobmark = so->so_rcv.sb_cc + (mark-tp->rcv_nxt);
+ if (so->so_oobmark == 0)
+ so->so_state |= SS_RCVATMARK;
+printf("take oob data %x input iobseq now %x\n", tp->t_iobc, tp->t_iobseq);
+ sohasoutofband(so);
+ break;
+ }
+
+ case TCPOPT_OOBACK: {
+ int seq;
+
+ if (optlen != 4)
+ continue;
+ if (tp->t_oobseq != cp[2]) {
+printf("wrong ack\n");
+ break;
+ }
+printf("take oob ack %x and cancel rexmt\n", cp[2]);
+ tp->t_oobflags &= ~TCPOOB_NEEDACK;
+ tp->t_timer[TCPT_OOBREXMT] = 0;
+ break;
+ }
+#endif TCPTRUEOOB
+ }
+ }
+ (void) m_free(om);
+}
+
+/*
+ * Pull out of band byte out of a segment so
+ * it doesn't appear in the user's data queue.
+ * It is still reflected in the segment length for
+ * sequencing purposes.
+ */
+tcp_pulloutofband(so, ti)
+ struct socket *so;
+ struct tcpiphdr *ti;
+{
+ register struct mbuf *m;
+ int cnt = ti->ti_urp - 1;
+
+ m = dtom(ti);
+ while (cnt >= 0) {
+ if (m->m_len > cnt) {
+ char *cp = mtod(m, caddr_t) + cnt;
+ struct tcpcb *tp = sototcpcb(so);
+
+ tp->t_iobc = *cp;
+ tp->t_oobflags |= TCPOOB_HAVEDATA;
+ bcopy(cp+1, cp, (unsigned)(m->m_len - cnt - 1));
+ m->m_len--;
+ return;
+ }
+ cnt -= m->m_len;
+ m = m->m_next;
+ if (m == 0)
+ break;
+ }
+ panic("tcp_pulloutofband");
}
/*
{
register struct tcpiphdr *q;
struct socket *so = tp->t_inpcb->inp_socket;
- int flags = 0; /* no FIN */
-COUNT(TCP_REASS);
+ struct mbuf *m;
+ int flags;
/*
* Call with ti==0 after become established to
*/
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) {
* 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;
}
q = (struct tcpiphdr *)q->ti_next;
- m_freem(dtom(q->ti_prev));
+ m = dtom(q->ti_prev);
remque(q->ti_prev);
+ m_freem(m);
}
/*
*/
insque(ti, q->ti_prev);
- /*
- * Advance rcv_next through newly completed sequence space.
- */
- while (ti->ti_seq == tp->rcv_nxt) {
- tp->rcv_nxt += ti->ti_len;
- flags = ti->ti_flags & TH_FIN;
- ti = (struct tcpiphdr *)ti->ti_next;
- if (ti == (struct tcpiphdr *)tp)
- break;
- }
-
present:
/*
- * Present data to user.
+ * Present data to user, advancing rcv_nxt through
+ * completed sequence space.
*/
- if (tp->t_state < TCPS_ESTABLISHED)
- return (flags);
+ if (TCPS_HAVERCVDSYN(tp->t_state) == 0)
+ return (0);
ti = tp->seg_next;
- while (ti != (struct tcpiphdr *)tp && ti->ti_seq < tp->rcv_nxt) {
+ if (ti == (struct tcpiphdr *)tp || ti->ti_seq != tp->rcv_nxt)
+ return (0);
+ if (tp->t_state == TCPS_SYN_RECEIVED && ti->ti_len)
+ return (0);
+ do {
+ tp->rcv_nxt += ti->ti_len;
+ flags = ti->ti_flags & TH_FIN;
remque(ti);
- sbappend(&so->so_rcv, dtom(ti));
+ m = dtom(ti);
ti = (struct tcpiphdr *)ti->ti_next;
- }
- if (so->so_state & SS_CANTRCVMORE)
- sbflush(&so->so_rcv);
- else
- sorwakeup(so);
+ if (so->so_state & SS_CANTRCVMORE)
+ m_freem(m);
+ else
+ sbappend(&so->so_rcv, m);
+ } while (ti != (struct tcpiphdr *)tp && ti->ti_seq == tp->rcv_nxt);
+ sorwakeup(so);
return (flags);
drop:
m_freem(dtom(ti));
- return (flags);
+ return (0);
}