home *** CD-ROM | disk | FTP | other *** search
- /* prott.c
- The 't' protocol.
-
- Copyright (C) 1991, 1992 Ian Lance Taylor
-
- This file is part of the Taylor UUCP package.
-
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
-
- This program is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
-
- 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., 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, 48 Grove Street, Somerville, MA 02144.
- */
-
- #include "uucp.h"
-
- #if USE_RCS_ID
- const char prott_rcsid[] = "$Id: prott.c,v 1.29 1995/06/21 19:15:36 ian Rel $";
- #endif
-
- #include "uudefs.h"
- #include "uuconf.h"
- #include "conn.h"
- #include "trans.h"
- #include "system.h"
- #include "prot.h"
-
- /* This implementation is based on code written by Rick Adams.
-
- This code implements the 't' protocol, which does no error checking
- whatsoever and thus requires an end-to-end verified eight bit
- communication line, such as is provided by TCP. Using it with a
- modem is unadvisable, since errors can occur between the modem and
- the computer. */
-
- /* The buffer size we use. */
- #define CTBUFSIZE (1024)
-
- /* The offset in the buffer to the data. */
- #define CTFRAMELEN (4)
-
- /* Commands are sent in multiples of this size. */
- #define CTPACKSIZE (512)
-
- /* A pointer to the buffer we will use. */
- static char *zTbuf;
-
- /* True if we are receiving a file. */
- static boolean fTfile;
-
- /* The timeout we use. */
- static int cTtimeout = 120;
-
- struct uuconf_cmdtab asTproto_params[] =
- {
- { "timeout", UUCONF_CMDTABTYPE_INT, (pointer) &cTtimeout, NULL },
- { NULL, 0, NULL, NULL }
- };
-
- /* Local function. */
-
- static boolean ftprocess_data P((struct sdaemon *qdaemon, boolean *pfexit,
- size_t *pcneed));
-
- /* Start the protocol. */
-
- boolean
- ftstart (qdaemon, pzlog)
- struct sdaemon *qdaemon;
- char **pzlog;
- {
- *pzlog = NULL;
- if (! fconn_set (qdaemon->qconn, PARITYSETTING_NONE,
- STRIPSETTING_EIGHTBITS, XONXOFF_OFF))
- return FALSE;
- zTbuf = (char *) xmalloc (CTBUFSIZE + CTFRAMELEN);
- /* The first two bytes of the buffer are always zero. */
- zTbuf[0] = 0;
- zTbuf[1] = 0;
- fTfile = FALSE;
- usysdep_sleep (2);
- return TRUE;
- }
-
- /* Stop the protocol. */
-
- /*ARGSUSED*/
- boolean
- ftshutdown (qdaemon)
- struct sdaemon *qdaemon;
- {
- xfree ((pointer) zTbuf);
- zTbuf = NULL;
- cTtimeout = 120;
- return TRUE;
- }
-
- /* Send a command string. We send everything up to and including the
- null byte. The number of bytes we send must be a multiple of
- TPACKSIZE. */
-
- /*ARGSUSED*/
- boolean
- ftsendcmd (qdaemon, z, ilocal, iremote)
- struct sdaemon *qdaemon;
- const char *z;
- int ilocal;
- int iremote;
- {
- size_t clen, csend;
- char *zalc;
- boolean fret;
-
- DEBUG_MESSAGE1 (DEBUG_UUCP_PROTO, "ftsendcmd: Sending command \"%s\"", z);
-
- clen = strlen (z);
-
- /* We need to send the smallest multiple of CTPACKSIZE which is
- greater than clen (not equal to clen, since we need room for the
- null byte). */
- csend = ((clen / CTPACKSIZE) + 1) * CTPACKSIZE;
-
- zalc = zbufalc (csend);
- memcpy (zalc, z, clen);
- if (csend > clen)
- bzero (zalc + clen, csend - clen);
-
- fret = fsend_data (qdaemon->qconn, zalc, csend, TRUE);
- ubuffree (zalc);
- return fret;
- }
-
- /* Get space to be filled with data. We provide a buffer which has
- four bytes at the start available to hold the length. */
-
- /*ARGSIGNORED*/
- char *
- ztgetspace (qdaemon, pclen)
- struct sdaemon *qdaemon;
- size_t *pclen;
- {
- *pclen = CTBUFSIZE;
- return zTbuf + CTFRAMELEN;
- }
-
- /* Send out some data. We are allowed to modify the four bytes
- preceding the buffer. This allows us to send the entire block with
- header bytes in a single call. */
-
- /*ARGSIGNORED*/
- boolean
- ftsenddata (qdaemon, zdata, cdata, ilocal, iremote, ipos)
- struct sdaemon *qdaemon;
- char *zdata;
- size_t cdata;
- int ilocal;
- int iremote;
- long ipos;
- {
- /* Here we do htonl by hand, since it doesn't exist everywhere. We
- know that the amount of data cannot be greater than CTBUFSIZE, so
- the first two bytes of this value will always be 0. They were
- set to 0 in ftstart so we don't touch them here. This is useful
- because we cannot portably right shift by 24 or 16, since we
- might be dealing with sixteen bit integers. */
- zdata[-2] = (char) ((cdata >> 8) & 0xff);
- zdata[-1] = (char) (cdata & 0xff);
-
- /* We pass FALSE to fsend_data since we don't expect the other side
- to be sending us anything just now. */
- return fsend_data (qdaemon->qconn, zdata - CTFRAMELEN, cdata + CTFRAMELEN,
- FALSE);
- }
-
- /* Process data and return the amount we need in *pfneed. */
-
- static boolean
- ftprocess_data (qdaemon, pfexit, pcneed)
- struct sdaemon *qdaemon;
- boolean *pfexit;
- size_t *pcneed;
- {
- int cinbuf, cfirst, clen;
-
- *pfexit = FALSE;
-
- cinbuf = iPrecend - iPrecstart;
- if (cinbuf < 0)
- cinbuf += CRECBUFLEN;
-
- if (! fTfile)
- {
- /* We are not receiving a file. Commands are read in chunks of
- CTPACKSIZE. */
- while (cinbuf >= CTPACKSIZE)
- {
- cfirst = CRECBUFLEN - iPrecstart;
- if (cfirst > CTPACKSIZE)
- cfirst = CTPACKSIZE;
-
- DEBUG_MESSAGE1 (DEBUG_PROTO,
- "ftprocess_data: Got %d command bytes",
- cfirst);
-
- if (! fgot_data (qdaemon, abPrecbuf + iPrecstart,
- (size_t) cfirst, abPrecbuf,
- (size_t) CTPACKSIZE - cfirst,
- -1, -1, (long) -1, TRUE, pfexit))
- return FALSE;
-
- iPrecstart = (iPrecstart + CTPACKSIZE) % CRECBUFLEN;
-
- if (*pfexit)
- return TRUE;
-
- cinbuf -= CTPACKSIZE;
- }
-
- if (pcneed != NULL)
- *pcneed = CTPACKSIZE - cinbuf;
-
- return TRUE;
- }
-
- /* Here we are receiving a file. The data comes in blocks. The
- first four bytes contain the length, followed by that amount of
- data. */
-
- while (cinbuf >= CTFRAMELEN)
- {
- /* The length is stored in network byte order, MSB first. */
-
- clen = (((((((abPrecbuf[iPrecstart] & 0xff) << 8)
- + (abPrecbuf[(iPrecstart + 1) % CRECBUFLEN] & 0xff)) << 8)
- + (abPrecbuf[(iPrecstart + 2) % CRECBUFLEN] & 0xff)) << 8)
- + (abPrecbuf[(iPrecstart + 3) % CRECBUFLEN] & 0xff));
-
- if (cinbuf < clen + CTFRAMELEN)
- {
- if (pcneed != NULL)
- *pcneed = clen + CTFRAMELEN - cinbuf;
- return TRUE;
- }
-
- iPrecstart = (iPrecstart + CTFRAMELEN) % CRECBUFLEN;
-
- cfirst = CRECBUFLEN - iPrecstart;
- if (cfirst > clen)
- cfirst = clen;
-
- DEBUG_MESSAGE1 (DEBUG_PROTO,
- "ftprocess_data: Got %d data bytes",
- clen);
-
- if (! fgot_data (qdaemon, abPrecbuf + iPrecstart,
- (size_t) cfirst, abPrecbuf, (size_t) (clen - cfirst),
- -1, -1, (long) -1, TRUE, pfexit))
- return FALSE;
-
- iPrecstart = (iPrecstart + clen) % CRECBUFLEN;
-
- if (*pfexit)
- return TRUE;
-
- cinbuf -= clen + CTFRAMELEN;
- }
-
- if (pcneed != NULL)
- *pcneed = CTFRAMELEN - cinbuf;
-
- return TRUE;
- }
-
- /* Wait for data to come in and process it until we've reached the end
- of a command or a file. */
-
- boolean
- ftwait (qdaemon)
- struct sdaemon *qdaemon;
- {
- while (TRUE)
- {
- boolean fexit;
- size_t cneed, crec;
-
- if (! ftprocess_data (qdaemon, &fexit, &cneed))
- return FALSE;
- if (fexit)
- return TRUE;
-
- if (! freceive_data (qdaemon->qconn, cneed, &crec, cTtimeout, TRUE))
- return FALSE;
-
- if (crec == 0)
- {
- ulog (LOG_ERROR, "Timed out waiting for data");
- return FALSE;
- }
- }
- }
-
- /* File level routine, to set fTfile correctly. */
-
- /*ARGSUSED*/
- boolean
- ftfile (qdaemon, qtrans, fstart, fsend, cbytes, pfhandled)
- struct sdaemon *qdaemon;
- struct stransfer *qtrans;
- boolean fstart;
- boolean fsend;
- long cbytes;
- boolean *pfhandled;
- {
- *pfhandled = FALSE;
-
- if (! fsend)
- fTfile = fstart;
-
- return TRUE;
- }
-