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-rw-r--r--gnu/libexec/uucp/uucico/proti.c261
1 files changed, 177 insertions, 84 deletions
diff --git a/gnu/libexec/uucp/uucico/proti.c b/gnu/libexec/uucp/uucico/proti.c
index d14d42b42db0..fd243de23731 100644
--- a/gnu/libexec/uucp/uucico/proti.c
+++ b/gnu/libexec/uucp/uucico/proti.c
@@ -1,7 +1,7 @@
/* proti.c
The 'i' protocol.
- Copyright (C) 1992 Ian Lance Taylor
+ Copyright (C) 1992, 1993 Ian Lance Taylor
This file is part of the Taylor UUCP package.
@@ -20,13 +20,13 @@
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
The author of the program may be contacted at ian@airs.com or
- c/o Infinity Development Systems, P.O. Box 520, Waltham, MA 02254.
+ c/o Cygnus Support, Building 200, 1 Kendall Square, Cambridge, MA 02139.
*/
#include "uucp.h"
#if USE_RCS_ID
-const char proti_rcsid[] = "$Id: proti.c,v 1.1 1993/08/05 18:27:12 conklin Exp $";
+const char proti_rcsid[] = "$Id: proti.c,v 1.2 1994/05/07 18:13:48 ache Exp $";
#endif
#include <ctype.h>
@@ -153,7 +153,10 @@ const char proti_rcsid[] = "$Id: proti.c,v 1.1 1993/08/05 18:27:12 conklin Exp $
#define IMAXSEQ 32
/* Get the next sequence number given a sequence number. */
-#define INEXTSEQ(i) ((i + 1) & (IMAXSEQ - 1))
+#define INEXTSEQ(i) (((i) + 1) & (IMAXSEQ - 1))
+
+/* Get the previous sequence number given a sequence number. */
+#define IPREVSEQ(i) (((i) + IMAXSEQ - 1) & (IMAXSEQ - 1))
/* Compute i1 - i2 in sequence space (i.e., the number of packets from
i2 to i1). */
@@ -216,17 +219,14 @@ static int iIremote_packsize;
static int iIalc_packsize;
/* Forced remote packet size, used if non-zero (protocol parameter
- ``remote-packet-size''). */
+ ``remote-packet-size''). There is no forced remote window size
+ because the ACK strategy requires that both sides agree on the
+ window size. */
static int iIforced_remote_packsize = 0;
-/* Remote window size (set from SYNC packet or from
- iIforced_remote_winsize). */
+/* Remote window size (set from SYNC packet). */
static int iIremote_winsize;
-/* Forced remote window size, used if non-zero (protocol parameter
- ``remote-window''). */
-static int iIforced_remote_winsize = 0;
-
/* Timeout to use when sending the SYNC packet (protocol
parameter ``sync-timeout''). */
int cIsync_timeout = CSYNC_TIMEOUT;
@@ -251,6 +251,11 @@ static int cIerrors = CERRORS;
the error level by one (protocol parameter ``error-decay''). */
static int cIerror_decay = CERROR_DECAY;
+/* The number of packets we should wait to receive before sending an
+ ACK; this is set by default to half the window size we have
+ requested (protocol parameter ``ack-frequency''). */
+static int cIack_frequency = 0;
+
/* The set of characters to avoid (protocol parameter ``avoid'').
This is actually part of the 'j' protocol; it is defined in this
file because the 'i' and 'j' protocols use the same protocol
@@ -334,8 +339,6 @@ struct uuconf_cmdtab asIproto_params[] =
{ "window", UUCONF_CMDTABTYPE_INT, (pointer) &iIrequest_winsize, NULL },
{ "remote-packet-size", UUCONF_CMDTABTYPE_INT,
(pointer) &iIforced_remote_packsize, NULL },
- { "remote-window", UUCONF_CMDTABTYPE_INT,
- (pointer) &iIforced_remote_winsize, NULL },
{ "sync-timeout", UUCONF_CMDTABTYPE_INT, (pointer) &cIsync_timeout,
NULL },
{ "sync-retries", UUCONF_CMDTABTYPE_INT, (pointer) &cIsync_retries,
@@ -344,6 +347,7 @@ struct uuconf_cmdtab asIproto_params[] =
{ "retries", UUCONF_CMDTABTYPE_INT, (pointer) &cIretries, NULL },
{ "errors", UUCONF_CMDTABTYPE_INT, (pointer) &cIerrors, NULL },
{ "error-decay", UUCONF_CMDTABTYPE_INT, (pointer) &cIerror_decay, NULL },
+ { "ack-frequency", UUCONF_CMDTABTYPE_INT, (pointer) &cIack_frequency, NULL },
/* The ``avoid'' protocol parameter is part of the 'j' protocol, but
it is convenient for the 'i' and 'j' protocols to share the same
protocol parameter table. */
@@ -398,7 +402,7 @@ fijstart (qdaemon, pzlog, imaxpacksize, pfsend, pfreceive)
boolean (*pfreceive) P((struct sconnection *qconn, size_t cneed,
size_t *pcrec, int ctimeout, boolean freport));
{
- char ab[CHDRLEN + 3 + CCKSUMLEN];
+ char ab[CHDRLEN + 4 + CCKSUMLEN];
unsigned long icksum;
int ctries;
int csyncs;
@@ -414,10 +418,6 @@ fijstart (qdaemon, pzlog, imaxpacksize, pfsend, pfreceive)
else
iIremote_packsize = iIforced_remote_packsize;
iIalc_packsize = 0;
- if (iIforced_remote_winsize <= 0 || iIforced_remote_winsize >= IMAXSEQ)
- iIforced_remote_winsize = 0;
- else
- iIremote_winsize = iIforced_remote_winsize;
iIsendseq = 1;
iIrecseq = 0;
@@ -435,16 +435,41 @@ fijstart (qdaemon, pzlog, imaxpacksize, pfsend, pfreceive)
cIbad_cksum = 0;
cIremote_rejects = 0;
+ if (iIrequest_packsize < 0 || iIrequest_packsize > imaxpacksize)
+ {
+ ulog (LOG_ERROR, "Illegal protocol '%c' packet size; using %d",
+ qdaemon->qproto->bname, imaxpacksize);
+ iIrequest_packsize = imaxpacksize;
+ }
+
+ /* The maximum permissible window size is 16. Otherwise the
+ protocol can get confused because a duplicated packet may arrive
+ out of order. If the window size is large in such a case, the
+ duplicate packet may be treated as a packet in the upcoming
+ window, causing the protocol to assume that all intermediate
+ packets have been lost, leading to immense confusion. */
+ if (iIrequest_winsize < 0 || iIrequest_winsize > IMAXSEQ / 2)
+ {
+ ulog (LOG_ERROR, "Illegal protocol '%c' window size; using %d",
+ qdaemon->qproto->bname, IREQUEST_WINSIZE);
+ iIrequest_winsize = IREQUEST_WINSIZE;
+ }
+
+ /* The default for the ACK frequency is half the window size. */
+ if (cIack_frequency <= 0 || cIack_frequency >= iIrequest_winsize)
+ cIack_frequency = iIrequest_winsize / 2;
+
ab[IHDR_INTRO] = IINTRO;
ab[IHDR_LOCAL] = ab[IHDR_REMOTE] = IHDRWIN_SET (0, 0);
- ab[IHDR_CONTENTS1] = IHDRCON_SET1 (SYNC, qdaemon->fcaller, 3);
- ab[IHDR_CONTENTS2] = IHDRCON_SET2 (SYNC, qdaemon->fcaller, 3);
+ ab[IHDR_CONTENTS1] = IHDRCON_SET1 (SYNC, qdaemon->fcaller, 4);
+ ab[IHDR_CONTENTS2] = IHDRCON_SET2 (SYNC, qdaemon->fcaller, 4);
ab[IHDR_CHECK] = IHDRCHECK_VAL (ab);
ab[CHDRLEN + 0] = (iIrequest_packsize >> 8) & 0xff;
ab[CHDRLEN + 1] = iIrequest_packsize & 0xff;
ab[CHDRLEN + 2] = iIrequest_winsize;
- icksum = icrc (ab + CHDRLEN, 3, ICRCINIT);
- UCKSUM_SET (ab + CHDRLEN + 3, icksum);
+ ab[CHDRLEN + 3] = qdaemon->cchans;
+ icksum = icrc (ab + CHDRLEN, 4, ICRCINIT);
+ UCKSUM_SET (ab + CHDRLEN + 4, icksum);
/* The static cIsyncs is incremented each time a SYNC packet is
received. */
@@ -455,11 +480,11 @@ fijstart (qdaemon, pzlog, imaxpacksize, pfsend, pfreceive)
{
boolean ftimedout;
- DEBUG_MESSAGE2 (DEBUG_PROTO,
- "fistart: Sending SYNC packsize %d winsize %d",
- iIrequest_packsize, iIrequest_winsize);
+ DEBUG_MESSAGE3 (DEBUG_PROTO,
+ "fistart: Sending SYNC packsize %d winsize %d channels %d",
+ iIrequest_packsize, iIrequest_winsize, qdaemon->cchans);
- if (! (*pfIsend) (qdaemon->qconn, ab, CHDRLEN + 3 + CCKSUMLEN,
+ if (! (*pfIsend) (qdaemon->qconn, ab, CHDRLEN + 4 + CCKSUMLEN,
TRUE))
return FALSE;
@@ -509,11 +534,15 @@ fijstart (qdaemon, pzlog, imaxpacksize, pfsend, pfreceive)
if (iseq >= IMAXSEQ)
{
- *pzlog = zbufalc (sizeof "protocol 'i' packet size %d window %d"
- + 50);
- sprintf (*pzlog, "protocol '%c' packet size %d window %d",
- qdaemon->qproto->bname, iIremote_packsize,
- iIremote_winsize);
+ *pzlog =
+ zbufalc (sizeof "protocol '' sending packet/window / receiving /"
+ + 64);
+ sprintf (*pzlog,
+ "protocol '%c' sending packet/window %d/%d receiving %d/%d",
+ qdaemon->qproto->bname, (int) iIremote_packsize,
+ (int) iIremote_winsize, (int) iIrequest_packsize,
+ (int) iIrequest_winsize);
+
iIalc_packsize = iIremote_packsize;
return TRUE;
@@ -575,13 +604,13 @@ fishutdown (qdaemon)
iIrequest_packsize = IREQUEST_PACKSIZE;
iIrequest_winsize = IREQUEST_WINSIZE;
iIforced_remote_packsize = 0;
- iIforced_remote_winsize = 0;
cIsync_timeout = CSYNC_TIMEOUT;
cIsync_retries = CSYNC_RETRIES;
cItimeout = CTIMEOUT;
cIretries = CRETRIES;
cIerrors = CERRORS;
cIerror_decay = CERROR_DECAY;
+ cIack_frequency = 0;
zJavoid_parameter = ZAVOID;
return TRUE;
@@ -835,8 +864,9 @@ fisenddata (qdaemon, zdata, cdata, ilocal, iremote, ipos)
iIlocal_ack = iIrecseq;
zhdr[IHDR_CHECK] = IHDRCHECK_VAL (zhdr);
- DEBUG_MESSAGE2 (DEBUG_PROTO, "fisenddata: Sending packet %d (%d bytes)",
- iIsendseq, (int) cdata);
+ DEBUG_MESSAGE4 (DEBUG_PROTO,
+ "fisenddata: Sending packet %d size %d local %d remote %d",
+ iIsendseq, (int) cdata, ilocal, iremote);
iIsendseq = INEXTSEQ (iIsendseq);
++cIsent_packets;
@@ -977,6 +1007,8 @@ ficheck_errors (qdaemon)
char absync[CHDRLEN + 3 + CCKSUMLEN];
unsigned long icksum;
+ /* Don't bother sending the number of channels in this
+ packet. */
iIrequest_packsize /= 2;
absync[IHDR_INTRO] = IINTRO;
absync[IHDR_LOCAL] = IHDRWIN_SET (0, 0);
@@ -1127,9 +1159,9 @@ fiprocess_data (qdaemon, pfexit, pffound, pcneed)
if (iIrequest_winsize > 0
&& CSEQDIFF (iseq, iIlocal_ack) > iIrequest_winsize)
{
- DEBUG_MESSAGE1 (DEBUG_PROTO | DEBUG_ABNORMAL,
- "fiprocess_data: Out of order packet %d",
- iseq);
+ DEBUG_MESSAGE2 (DEBUG_PROTO | DEBUG_ABNORMAL,
+ "fiprocess_data: Out of order packet %d (ack %d)",
+ iseq, iIlocal_ack);
++cIbad_order;
if (! ficheck_errors (qdaemon))
@@ -1253,7 +1285,27 @@ fiprocess_data (qdaemon, pfexit, pffound, pcneed)
if (iseq != -1)
{
- afInaked[iseq] = FALSE;
+ /* If we already sent a NAK for this packet, and we have not
+ seen the previous packet, then forget that we sent a NAK
+ for this and any preceding packets. This is to handle
+ the following sequence:
+ receive packet 0
+ packets 1 and 2 lost
+ receive packet 3
+ send NAK 1
+ send NAK 2
+ packet 1 lost
+ receive packet 2
+ At this point we want to send NAK 1. */
+ if (afInaked[iseq]
+ && azIrecbuffers[IPREVSEQ (iseq)] == NULL)
+ {
+ for (i = INEXTSEQ (iIrecseq);
+ i != iseq;
+ i = INEXTSEQ (i))
+ afInaked[i] = FALSE;
+ afInaked[iseq] = FALSE;
+ }
/* If we haven't handled all previous packets, we must save
off this packet and deal with it later. */
@@ -1263,16 +1315,16 @@ fiprocess_data (qdaemon, pfexit, pffound, pcneed)
|| (iIrequest_winsize > 0
&& CSEQDIFF (iseq, iIrecseq) > iIrequest_winsize))
{
- DEBUG_MESSAGE1 (DEBUG_PROTO | DEBUG_ABNORMAL,
- "fiprocess_data: Ignoring out of order packet %d",
- iseq);
+ DEBUG_MESSAGE2 (DEBUG_PROTO | DEBUG_ABNORMAL,
+ "fiprocess_data: Ignoring out of order packet %d (recseq %d)",
+ iseq, iIrecseq);
continue;
}
else
{
- DEBUG_MESSAGE1 (DEBUG_PROTO | DEBUG_ABNORMAL,
- "fiprocess_data: Saving unexpected packet %d",
- iseq);
+ DEBUG_MESSAGE2 (DEBUG_PROTO | DEBUG_ABNORMAL,
+ "fiprocess_data: Saving unexpected packet %d (recseq %d)",
+ iseq, iIrecseq);
if (azIrecbuffers[iseq] == NULL)
{
@@ -1352,7 +1404,7 @@ fiprocess_data (qdaemon, pfexit, pffound, pcneed)
However, it can happen if we receive a burst of short
packets, such as a set of command acknowledgements. */
if (iIrequest_winsize > 0
- && CSEQDIFF (iIrecseq, iIlocal_ack) >= iIrequest_winsize / 2)
+ && CSEQDIFF (iIrecseq, iIlocal_ack) >= cIack_frequency)
{
char aback[CHDRLEN];
@@ -1401,9 +1453,11 @@ fiprocess_packet (qdaemon, zhdr, zfirst, cfirst, zsecond, csecond, pfexit)
boolean fret;
iseq = IHDRWIN_GETSEQ (zhdr[IHDR_LOCAL]);
- DEBUG_MESSAGE2 (DEBUG_PROTO,
- "fiprocess_packet: Got DATA packet %d size %d",
- iseq, cfirst + csecond);
+ DEBUG_MESSAGE4 (DEBUG_PROTO,
+ "fiprocess_packet: Got DATA packet %d size %d local %d remote %d",
+ iseq, cfirst + csecond,
+ IHDRWIN_GETCHAN (zhdr[IHDR_REMOTE]),
+ IHDRWIN_GETCHAN (zhdr[IHDR_LOCAL]));
fret = fgot_data (qdaemon, zfirst, (size_t) cfirst,
zsecond, (size_t) csecond,
IHDRWIN_GETCHAN (zhdr[IHDR_REMOTE]),
@@ -1417,7 +1471,7 @@ fiprocess_packet (qdaemon, zhdr, zfirst, cfirst, zsecond, csecond, pfexit)
case SYNC:
{
- int ipack, iwin;
+ int ipack, iwin, cchans;
/* We accept a SYNC packet to adjust the packet and window
sizes at any time. */
@@ -1436,16 +1490,31 @@ fiprocess_packet (qdaemon, zhdr, zfirst, cfirst, zsecond, csecond, pfexit)
else
iwin = zsecond[2 - cfirst];
- DEBUG_MESSAGE2 (DEBUG_PROTO,
- "fiprocess_packet: Got SYNC packsize %d winsize %d",
- ipack, iwin);
+ /* The fourth byte in a SYNC packet is the number of channels
+ to use. This is optional. Switching the number of
+ channels in the middle of a conversation may cause
+ problems. */
+ if (cfirst + csecond <= 3)
+ cchans = 0;
+ else
+ {
+ if (cfirst > 3)
+ cchans = zfirst[3];
+ else
+ cchans = zsecond[3 - cfirst];
+ if (cchans > 0 && cchans < 8)
+ qdaemon->cchans = cchans;
+ }
+
+ DEBUG_MESSAGE3 (DEBUG_PROTO,
+ "fiprocess_packet: Got SYNC packsize %d winsize %d channels %d",
+ ipack, iwin, cchans);
if (iIforced_remote_packsize == 0
&& (iIalc_packsize == 0
|| ipack <= iIalc_packsize))
iIremote_packsize = ipack;
- if (iIforced_remote_winsize == 0)
- iIremote_winsize = iwin;
+ iIremote_winsize = iwin;
/* We increment a static variable to tell the initialization
code that a SYNC was received, and we set *pfexit to TRUE
@@ -1477,44 +1546,68 @@ fiprocess_packet (qdaemon, zhdr, zfirst, cfirst, zsecond, csecond, pfexit)
iseq = IHDRWIN_GETSEQ (zhdr[IHDR_LOCAL]);
- /* The timeout code will send a NAK for the packet the remote
- side wants. So we may see a NAK here for the packet we are
- about to send. */
- if (iseq == iIsendseq
- || (iIremote_winsize > 0
- && (CSEQDIFF (iseq, iIremote_ack) > iIremote_winsize
- || CSEQDIFF (iIsendseq, iseq) > iIremote_winsize)))
+ /* If the remote side times out while waiting for a packet, it
+ will send a NAK for the next packet it wants to see. If we
+ have not sent that packet yet, and we have no
+ unacknowledged data, it implies that the remote side has a
+ window full of data to send, which implies that our ACK has
+ been lost. Therefore, we send an ACK. */
+ if (iseq == iIsendseq &&
+ INEXTSEQ (iIremote_ack) == iIsendseq)
{
- DEBUG_MESSAGE1 (DEBUG_PROTO | DEBUG_ABNORMAL,
- "fiprocess_packet: Ignoring out of order NAK %d",
- iseq);
- return TRUE;
- }
+ char aback[CHDRLEN];
+
+ aback[IHDR_INTRO] = IINTRO;
+ aback[IHDR_LOCAL] = IHDRWIN_SET (0, 0);
+ aback[IHDR_REMOTE] = IHDRWIN_SET (iIrecseq, 0);
+ iIlocal_ack = iIrecseq;
+ aback[IHDR_CONTENTS1] = IHDRCON_SET1 (ACK, qdaemon->fcaller, 0);
+ aback[IHDR_CONTENTS2] = IHDRCON_SET2 (ACK, qdaemon->fcaller, 0);
+ aback[IHDR_CHECK] = IHDRCHECK_VAL (aback);
- DEBUG_MESSAGE1 (DEBUG_PROTO | DEBUG_ABNORMAL,
- "fiprocess_packet: Got NAK %d; resending packet",
- iseq);
+ DEBUG_MESSAGE1 (DEBUG_PROTO, "fiprocess_packet: Sending ACK %d",
+ iIrecseq);
- /* Update the received sequence number. */
- zsend = azIsendbuffers[iseq] + CHDROFFSET;
- if (IHDRWIN_GETSEQ (zsend[IHDR_REMOTE]) != iIrecseq)
+ return (*pfIsend) (qdaemon->qconn, aback, CHDRLEN, TRUE);
+ }
+ else
{
- int iremote;
+ if (iseq == iIsendseq
+ || (iIremote_winsize > 0
+ && (CSEQDIFF (iseq, iIremote_ack) > iIremote_winsize
+ || CSEQDIFF (iIsendseq, iseq) > iIremote_winsize)))
+ {
+ DEBUG_MESSAGE2 (DEBUG_PROTO | DEBUG_ABNORMAL,
+ "fiprocess_packet: Ignoring out of order NAK %d (sendseq %d)",
+ iseq, iIsendseq);
+ return TRUE;
+ }
- iremote = IHDRWIN_GETCHAN (zsend[IHDR_REMOTE]);
- zsend[IHDR_REMOTE] = IHDRWIN_SET (iIrecseq, iremote);
- zsend[IHDR_CHECK] = IHDRCHECK_VAL (zsend);
- iIlocal_ack = iIrecseq;
- }
+ DEBUG_MESSAGE1 (DEBUG_PROTO | DEBUG_ABNORMAL,
+ "fiprocess_packet: Got NAK %d; resending packet",
+ iseq);
+
+ /* Update the received sequence number. */
+ zsend = azIsendbuffers[iseq] + CHDROFFSET;
+ if (IHDRWIN_GETSEQ (zsend[IHDR_REMOTE]) != iIrecseq)
+ {
+ int iremote;
+
+ iremote = IHDRWIN_GETCHAN (zsend[IHDR_REMOTE]);
+ zsend[IHDR_REMOTE] = IHDRWIN_SET (iIrecseq, iremote);
+ zsend[IHDR_CHECK] = IHDRCHECK_VAL (zsend);
+ iIlocal_ack = iIrecseq;
+ }
- ++cIresent_packets;
+ ++cIresent_packets;
- clen = CHDRCON_GETBYTES (zsend[IHDR_CONTENTS1],
- zsend[IHDR_CONTENTS2]);
+ clen = CHDRCON_GETBYTES (zsend[IHDR_CONTENTS1],
+ zsend[IHDR_CONTENTS2]);
- return (*pfIsend) (qdaemon->qconn, zsend,
- CHDRLEN + clen + (clen > 0 ? CCKSUMLEN : 0),
- TRUE);
+ return (*pfIsend) (qdaemon->qconn, zsend,
+ CHDRLEN + clen + (clen > 0 ? CCKSUMLEN : 0),
+ TRUE);
+ }
}
case SPOS:
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 05:01:29 +0000