diff options
Diffstat (limited to 'gnu/libexec/uucp/uucico/proti.c')
| -rw-r--r-- | gnu/libexec/uucp/uucico/proti.c | 65 |
1 files changed, 54 insertions, 11 deletions
diff --git a/gnu/libexec/uucp/uucico/proti.c b/gnu/libexec/uucp/uucico/proti.c index 17b540e..3209892 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, 1993 Ian Lance Taylor + Copyright (C) 1992, 1993, 1995 Ian Lance Taylor This file is part of the Taylor UUCP package. @@ -17,16 +17,16 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. The author of the program may be contacted at ian@airs.com or - c/o Cygnus Support, Building 200, 1 Kendall Square, Cambridge, MA 02139. + c/o Cygnus Support, 48 Grove Street, Somerville, MA 02144. */ #include "uucp.h" #if USE_RCS_ID -const char proti_rcsid[] = "$Id: proti.c,v 1.2 1994/05/07 18:13:48 ache Exp $"; +const char proti_rcsid[] = "$Id: proti.c,v 1.33 1995/06/21 19:15:28 ian Rel $"; #endif #include <ctype.h> @@ -146,8 +146,8 @@ const char proti_rcsid[] = "$Id: proti.c,v 1.2 1994/05/07 18:13:48 ache Exp $"; #define SPOS (4) #define CLOSE (5) -/* Largest possible packet size (plus 1). */ -#define IMAXPACKSIZE (1 << 12) +/* Largest possible packet size. */ +#define IMAXPACKSIZE ((1 << 12) - 1) /* Largest possible sequence number (plus 1). */ #define IMAXSEQ 32 @@ -239,6 +239,11 @@ static int cIsync_retries = CSYNC_RETRIES; ``timeout''). */ static int cItimeout = CTIMEOUT; +/* Timeout to use when waiting for an acknowledgement to open up space + in the window. This is computed based on the window size and the + connection speed. */ +static int cIwindow_timeout = CTIMEOUT; + /* Number of times to retry sending a packet before giving up (protocol parameter ``retries''). */ static int cIretries = CRETRIES; @@ -406,6 +411,7 @@ fijstart (qdaemon, pzlog, imaxpacksize, pfsend, pfreceive) unsigned long icksum; int ctries; int csyncs; + long ibaud; *pzlog = NULL; @@ -413,7 +419,7 @@ fijstart (qdaemon, pzlog, imaxpacksize, pfsend, pfreceive) pfIreceive = pfreceive; if (iIforced_remote_packsize <= 0 - || iIforced_remote_packsize >= imaxpacksize) + || iIforced_remote_packsize > imaxpacksize) iIforced_remote_packsize = 0; else iIremote_packsize = iIforced_remote_packsize; @@ -508,6 +514,42 @@ fijstart (qdaemon, pzlog, imaxpacksize, pfsend, pfreceive) } } + /* Calculate the window timeout. */ + ibaud = iconn_baud (qdaemon->qconn); + if (ibaud == 0) + cIwindow_timeout = cItimeout; + else + { + /* We expect to receive an ACK about halfway through each + window. In principle, an entire window might be sitting in a + modem buffer while we are waiting for an ACK. Therefore, the + minimum time we should wait for an ACK is + (1/2 window size) * (seconds / byte) + (roundtrip time) == + (1/2 window size) * (1 / (baud / 10)) + (roundtrip time) == + (1/2 window size) * (10 / baud) + (roundtrip time) == + (5 * (window size)) / baud + (roundtrip time) + + The window size is iIremote_packsize * iIremote_winsize. For + typical settings of packsize == 1024, winsize == 16, baud == + 9600, this equation works out to + (5 * 1024 * 16) / 9600 == 8 seconds + We then take cItimeout as the round trip time, which gives us + some flexibility. We get more flexibility because it is + quite likely that by the time we have finished sending out + the last packet in a window, the first one has already been + received by the remote system. */ + cIwindow_timeout = ((5 * iIremote_packsize * iIremote_winsize) / ibaud + + cItimeout); + } + + /* If we are the callee, bump both timeouts by one, to make it less + likely that both systems will timeout simultaneously. */ + if (! qdaemon->fcaller) + { + ++cItimeout; + ++cIwindow_timeout; + } + /* We got a SYNC packet; set up packet buffers to use. */ if (iIremote_packsize > imaxpacksize) iIremote_packsize = imaxpacksize; @@ -607,6 +649,7 @@ fishutdown (qdaemon) cIsync_timeout = CSYNC_TIMEOUT; cIsync_retries = CSYNC_RETRIES; cItimeout = CTIMEOUT; + cIwindow_timeout = CTIMEOUT; cIretries = CRETRIES; cIerrors = CERRORS; cIerror_decay = CERROR_DECAY; @@ -741,7 +784,7 @@ fiwindow_wait (qdaemon) sends the entire packet. Hopefully that will trigger an ACK or a NAK and get us going again. */ DEBUG_MESSAGE0 (DEBUG_PROTO, "fiwindow_wait: Waiting for ACK"); - if (! fiwait_for_packet (qdaemon, cItimeout, cIretries, + if (! fiwait_for_packet (qdaemon, cIwindow_timeout, cIretries, TRUE, (boolean *) NULL)) return FALSE; } @@ -866,7 +909,7 @@ fisenddata (qdaemon, zdata, cdata, ilocal, iremote, ipos) DEBUG_MESSAGE4 (DEBUG_PROTO, "fisenddata: Sending packet %d size %d local %d remote %d", - iIsendseq, (int) cdata, ilocal, iremote); + iIsendseq, (int) cdata, ilocal, iremote); iIsendseq = INEXTSEQ (iIsendseq); ++cIsent_packets; @@ -1535,7 +1578,7 @@ fiprocess_packet (qdaemon, zhdr, zfirst, cfirst, zsecond, csecond, pfexit) case NAK: /* We must resend the requested packet. */ - { + { int iseq; char *zsend; size_t clen; @@ -1598,7 +1641,7 @@ fiprocess_packet (qdaemon, zhdr, zfirst, cfirst, zsecond, csecond, pfexit) zsend[IHDR_CHECK] = IHDRCHECK_VAL (zsend); iIlocal_ack = iIrecseq; } - + ++cIresent_packets; clen = CHDRCON_GETBYTES (zsend[IHDR_CONTENTS1], |
