A set of functions that helps to maintain a PTY-device for modem emulation.
This commit is contained in:
Morten Rolland
parent
76a1ca2f81
commit
dfe1586629
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@ -0,0 +1,71 @@
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/* $Id$
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******************************************************************************
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Fax program for ISDN.
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Handle all communications over a pseudo-tty (pty) to emulate a modem.
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Copyright (C) 1999 Morten Rolland [Morten.Rolland@asker.mail.telia.com]
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Copyright (C) 1998 Andreas Beck [becka@ggi-project.org]
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Permission is hereby granted, free of charge, to any person obtaining a
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copy of this software and associated documentation files (the "Software"),
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to deal in the Software without restriction, including without limitation
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the rights to use, copy, modify, merge, publish, distribute, sublicense,
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and/or sell copies of the Software, and to permit persons to whom the
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Software is furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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THE AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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******************************************************************************
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*/
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#include <sys/types.h>
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#include <sys/timeb.h>
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#include <ifax/types.h>
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#ifndef _MISC_PTY_H
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#define _MISC_PTY_H
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#define PTY_BUFFERSIZE 512
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#define PTY_DEVNAME_SIZE 64
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struct PtyHandle {
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int ptyfd;
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struct timeb lastinput;
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enum {
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NO_LOGGING=0,
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LOG_ADVANCE_READ=1,
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LOG_SERVICE_READ=2,
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LOG_WRITE=4
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} debug;
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struct PtyBuffer {
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int wp, rp, size;
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ifax_uint8 buffer[PTY_BUFFERSIZE];
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} tx, rx;
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char device[PTY_DEVNAME_SIZE+2];
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};
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extern struct PtyHandle *pty_initialize(char *device);
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extern void pty_reset(struct PtyHandle *ph);
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extern int pty_write_max(struct PtyHandle *ph); /* How large write is OK */
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extern int pty_write_queued(struct PtyHandle *ph); /* Size of current queue */
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extern int pty_read_max(struct PtyHandle *ph); /* How large read is OK */extern void pty_write(struct PtyHandle *ph, void *buf, size_t size);
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extern void pty_prepare_select(struct PtyHandle *, int *,fd_set *, fd_set *);
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extern void pty_service_write(struct PtyHandle *ph);
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extern void pty_service_read(struct PtyHandle *ph);
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extern void pty_readbuffer(struct PtyHandle *ph, ifax_uint8 **buf, size_t *sz);
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extern void pty_advance(struct PtyHandle *ph, size_t size);
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extern void pty_printf(struct PtyHandle *ph, char *format, ... );
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#endif
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@ -0,0 +1,499 @@
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/* $Id$
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******************************************************************************
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Fax program for ISDN.
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Handle all communications over a pseudo-tty (pty) to emulate a modem.
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Copyright (C) 1999 Morten Rolland [Morten.Rolland@asker.mail.telia.com]
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Copyright (C) 1999 Andreas Beck [becka@ggi-project.org]
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Permission is hereby granted, free of charge, to any person obtaining a
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copy of this software and associated documentation files (the "Software"),
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to deal in the Software without restriction, including without limitation
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the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
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and/or sell copies of the Software, and to permit persons to whom the
|
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Software is furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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THE AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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******************************************************************************
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*/
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/* This module takes care of initialization and maintenance
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* of a pair of tty/pty for emulating a modem on a terminal
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* port.
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*/
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#include <stdio.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/timeb.h>
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#include <fcntl.h>
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#include <termios.h>
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#include <unistd.h>
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#include <errno.h>
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#include <string.h>
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#include <ifax/misc/pty.h>
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#include <ifax/debug.h>
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#include <ifax/misc/globals.h>
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#include <ifax/misc/malloc.h>
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/* Open and initialize a pty device. This is done both on initial setup
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* and later resets.
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*/
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static void pty_open(struct PtyHandle *ph)
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{
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struct termios tios;
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if ( (ph->ptyfd=open(ph->device,O_RDWR|O_NONBLOCK)) < 0 ) {
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ifax_dprintf(DEBUG_LAST,
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"%s: Unable to open pty device '%s': %s\n",
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progname,ph->device,strerror(errno));
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exit(1);
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}
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ph->rx.rp = ph->rx.wp = ph->rx.size = 0;
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ph->tx.rp = ph->tx.wp = ph->tx.size = 0;
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if ( tcgetattr(ph->ptyfd,&tios) ) {
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ifax_dprintf(DEBUG_LAST,
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"%s: Unable to tcgetattr pty device '%s': %s\n",
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progname,ph->device,strerror(errno));
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exit(1);
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}
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tios.c_lflag &= ~ECHO;
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if ( tcsetattr(ph->ptyfd,TCSANOW,&tios) ) {
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ifax_dprintf(DEBUG_LAST,
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"%s: Unable to tcsetattr pty device '%s: %s'\n",
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progname,ph->device,strerror(errno));
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exit(1);
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}
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}
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static void pty_dump(char *prefix, ifax_uint8 *log1, int logsize1,
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ifax_uint8 *log2, int logsize2)
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{
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char buffer[256];
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char item[8], *i;
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ifax_uint8 c;
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int wp, prefixlen, itemlen;
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static char *ctrl[33] = {
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"NUL","\\001","\\002","ETX","\\004","\\005","\\006","\\007",
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"\\010","\\011","\\n","\\013","\\014","\\r","\\016","\\017",
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"DLE","\\021","\\022","\\023","\\024","\\025","\\026","\\027",
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"\\030","\\031","\\032","ESC","\\034","\\035","\\036","\\037",
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"SPC"
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};
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wp = 0;
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prefixlen = strlen(prefix);
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while ( logsize1 > 0 ) {
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if ( wp == 0 ) {
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strcpy(buffer,prefix);
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wp = prefixlen;
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}
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c = *log1++;
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logsize1--;
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if ( c < 33 ) {
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i = ctrl[c];
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} else if ( c < 127 ) {
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item[0] = c;
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item[1] = '\0';
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i = item;
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} else {
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sprintf(item,"%03o",(int)c);
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i = item;
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}
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itemlen = strlen(i);
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buffer[wp++] = ' ';
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strcpy(&buffer[wp],i);
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wp += itemlen;
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if ( wp > 75 ) {
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buffer[wp++] = '\n';
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buffer[wp] = '\0';
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ifax_dprintf(DEBUG_DEBUG,buffer);
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wp = 0;
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}
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if ( logsize1 == 0 ) {
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logsize1 = logsize2;
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log1 = log2;
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logsize2 = 0;
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}
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}
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if ( wp ) {
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buffer[wp++] = '\n';
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buffer[wp] = '\0';
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ifax_dprintf(DEBUG_DEBUG,buffer);
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}
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}
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/* Allocate and initialize a pty instance for the given device.
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* Once initialized it can be read/written/serviced using all
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* functions in this file.
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*/
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struct PtyHandle *pty_initialize(char *device)
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{
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struct PtyHandle *ph;
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ph = ifax_malloc(sizeof(*ph),"PTY instance");
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if ( strlen(device) >= PTY_DEVNAME_SIZE ) {
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ifax_dprintf(DEBUG_LAST,
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"%s: Name of pty device '%s' too long\n",
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progname,device);
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exit(1);
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}
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strcpy(ph->device,device);
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ph->debug = 7;
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pty_open(ph);
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return ph;
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}
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/* Reset the pty by closing and re-opening the pty-file and initializing
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* it again, but maintain the same PtyHandle to it.
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*/
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void pty_reset(struct PtyHandle *ph)
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{
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ifax_dprintf(DEBUG_DEBUG, "%s: Resetting pty '%s'\n",
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progname,ph->device);
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close(ph->ptyfd);
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pty_open(ph);
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}
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/* This function returns how many bytes can be written to the pty
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* at this instance. Trying to write more bytes than this function
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* reports possible is undefined.
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*/
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int pty_write_max(struct PtyHandle *ph)
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{
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return PTY_BUFFERSIZE - ph->tx.size;
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}
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/* Return number of bytes queued on the write-queue. We may want
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* to watch this value to keep modem-to-modem flow control updated
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* on progress. The total buffer capacity is found with:
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*
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* pty_write_queued(ph) + pty_write_max(ph)
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*/
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int pty_write_queued(struct PtyHandle *ph)
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{
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return ph->tx.size;
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}
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/* Return how many bytes can be read from the pty. NOTE: The number of
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* bytes returned here may have to be accessed using two pty_reabbuffer
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* operations. In other words, this function may return 1000 bytes
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* available for reading, but the first call to pty_readbuffer may only
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* yield 1 byte... The next however will yield the remaining 999 bytes.
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*/
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int pty_read_max(struct PtyHandle *ph)
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{
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return ph->rx.size;
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}
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/* Write a buffer to the pty. It is important not to write more than
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* the software buffer can hold. If more is written, the result is
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* undefined.
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*/
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void pty_write(struct PtyHandle *ph, void *buffer, size_t size)
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{
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ifax_uint8 *dst, *src = buffer;
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size_t chunk;
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char prefix[256];
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if ( pty_write_max(ph) < size ) {
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ifax_dprintf(DEBUG_SEVERE,
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"%s: Overruns on output pty device '%s'\n",
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progname,ph->device);
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return;
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}
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if ( ph->debug & LOG_WRITE ) {
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sprintf(prefix,"PTY-wrt %s:",ph->device);
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pty_dump(prefix,buffer,size,0,0);
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}
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if ( ph->tx.wp >= ph->tx.rp ) {
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/* Unused space in both ends of buffer */
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dst = &ph->tx.buffer[ph->tx.wp];
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chunk = PTY_BUFFERSIZE - ph->tx.wp;
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ph->tx.size += size;
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if ( chunk > size ) {
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ph->tx.wp += size;
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memcpy(dst,src,size);
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} else {
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memcpy(dst,src,chunk);
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if ( (ph->tx.wp = size - chunk) > 0 ) {
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src += chunk;
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memcpy(&ph->tx.buffer[0],src,ph->tx.wp);
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}
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}
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return;
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}
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/* Unused space in the middle */
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memcpy(&ph->tx.buffer[ph->tx.wp],src,size);
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ph->tx.wp += size;
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ph->tx.size += size;
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}
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/* When a select is to be called to wait for things to happen, the
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* following function should be used to set up the read and write
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* fd_set structures so the wakeup conditions will be suitable
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* for the pty-service function.
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*/
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void pty_prepare_select(struct PtyHandle *ph, int *maxfd,
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fd_set *rfd, fd_set *wfd)
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{
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/* read only if rx buffer can hold data */
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if ( ph->rx.size < PTY_BUFFERSIZE ) {
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FD_SET(ph->ptyfd,rfd);
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} else {
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FD_CLR(ph->ptyfd,rfd);
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}
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/* Write only if there is anything queued */
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if ( ph->tx.size > 0 ) {
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FD_SET(ph->ptyfd,wfd);
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} else {
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FD_CLR(ph->ptyfd,wfd);
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}
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if ( ph->ptyfd + 1 > *maxfd )
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*maxfd = ph->ptyfd + 1;
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}
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/* Call this function regularly, preferably after a select has
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* indicated there is traffic or possible traffic on the pty.
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* This function will try to flush the output queue.
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*/
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void pty_service_write(struct PtyHandle *ph)
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{
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int chunk, rc;
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/* Try to flush tx-buffer if there is something queued */
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if ( ph->tx.size > 0 ) {
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chunk = PTY_BUFFERSIZE - ph->tx.rp;
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if ( chunk > ph->tx.size )
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chunk = ph->tx.size;
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rc = write(ph->ptyfd,&ph->tx.buffer[ph->tx.rp],chunk);
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if ( rc < 0 ) {
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if ( errno == EAGAIN )
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return;
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goto failed_write;
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}
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ph->tx.rp += rc;
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ph->tx.size -= rc;
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if ( rc < chunk )
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return;
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if ( ph->tx.rp >= PTY_BUFFERSIZE )
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ph->tx.rp = 0;
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if ( ph->tx.size > 0 ) {
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rc = write(ph->ptyfd,&ph->tx.buffer[0],ph->tx.size);
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if ( rc < 0 ) {
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if ( errno == EAGAIN )
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return;
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goto failed_write;
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}
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ph->tx.rp = rc;
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ph->tx.size -= rc;
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}
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}
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return;
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failed_write:
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ifax_dprintf(DEBUG_LAST,
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"%s: Can't write on pty '%s': %s\n",
|
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progname,ph->device,strerror(errno));
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exit(1);
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}
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|
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/* Call this function regularly, preferably after a select has
|
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* indicated there is traffic or possible traffic on the pty.
|
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* This function will try to read any new input into the input queue.
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*/
|
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void pty_service_read(struct PtyHandle *ph)
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{
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int chunk;
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char prefix[256];
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ifax_uint8 *log1 = 0, *log2 = 0;
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int logsize1, logsize2;
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logsize1 = logsize2 = 0;
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/* Try to read if there is space in rx-buffer */
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if ( (chunk = PTY_BUFFERSIZE - ph->rx.size) == 0 )
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return;
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if ( (PTY_BUFFERSIZE - ph->rx.wp) < chunk )
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chunk = PTY_BUFFERSIZE - ph->rx.wp;
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log1 = &ph->rx.buffer[ph->rx.wp];
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logsize1 = read(ph->ptyfd,log1,chunk);
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if ( logsize1 < 0 ) {
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if ( errno == EAGAIN )
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return;
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goto failed_read;
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}
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ph->rx.wp += logsize1;
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ph->rx.size += logsize1;
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if ( logsize1 < chunk )
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goto all_ok;
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if ( ph->rx.wp >= PTY_BUFFERSIZE )
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ph->rx.wp = 0;
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if ( (chunk = PTY_BUFFERSIZE - ph->rx.size) == 0 )
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goto all_ok;
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ph->rx.wp = 0;
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log2 = &ph->rx.buffer[ph->rx.wp];
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logsize2 = read(ph->ptyfd,log2,chunk);
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if ( logsize2 < 0 ) {
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if ( errno == EAGAIN ) {
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logsize2 = 0;
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goto all_ok;
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}
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goto failed_read;
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}
|
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ph->rx.wp += logsize2;
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ph->rx.size += logsize2;
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all_ok:
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if ( ph->debug & LOG_SERVICE_READ ) {
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sprintf(prefix,"PTY-srd %s:",ph->device);
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pty_dump(prefix,log1,logsize1,log2,logsize2);
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}
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return;
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failed_read:
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ifax_dprintf(DEBUG_DEBUG, "%s: Reading pty '%s' failed: %s\n",
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progname,ph->device,strerror(errno));
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pty_reset(ph);
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return;
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}
|
||||
|
||||
|
||||
/* The following function sets up a pointer into a buffer and
|
||||
* its size, which can be used for direct parsing without copying.
|
||||
* The size of the buffer returned may be shorter than the total
|
||||
* size of the receive buffer. Advance the pty by the full size
|
||||
* and call 'pty_next_buffer' to get access to the next chunk of
|
||||
* data.
|
||||
*/
|
||||
|
||||
void pty_readbuffer(struct PtyHandle *ph, ifax_uint8 **buffer, size_t *size)
|
||||
{
|
||||
size_t chunk;
|
||||
|
||||
*buffer = &ph->rx.buffer[ph->rx.rp];
|
||||
|
||||
chunk = PTY_BUFFERSIZE - ph->rx.rp;
|
||||
if ( ph->rx.size < chunk )
|
||||
chunk = ph->rx.size;
|
||||
|
||||
*size = chunk;
|
||||
}
|
||||
|
||||
/* The 'pty_advance' function advances the read buffer without any
|
||||
* memory copy operations, assuming they have been processed allready
|
||||
* (by 'pty_readbuffer') or can be discarded.
|
||||
*/
|
||||
|
||||
void pty_advance(struct PtyHandle *ph, size_t size)
|
||||
{
|
||||
int logsize1, logsize2;
|
||||
char prefix[256];
|
||||
|
||||
if ( ph->debug & LOG_ADVANCE_READ ) {
|
||||
|
||||
sprintf(prefix,"PTY-adv %s:",ph->device);
|
||||
|
||||
logsize1 = size;
|
||||
logsize2 = 0;
|
||||
if ( ph->rx.rp + logsize1 > PTY_BUFFERSIZE ) {
|
||||
logsize1 = PTY_BUFFERSIZE - ph->rx.rp;
|
||||
logsize2 = size - logsize1;
|
||||
}
|
||||
|
||||
pty_dump(prefix,&ph->rx.buffer[ph->rx.rp],logsize1,
|
||||
&ph->rx.buffer[0],logsize2);
|
||||
}
|
||||
|
||||
ph->rx.size -= size;
|
||||
ph->rx.rp += size;
|
||||
if ( ph->rx.rp >= PTY_BUFFERSIZE )
|
||||
ph->rx.rp -= PTY_BUFFERSIZE;
|
||||
}
|
||||
|
||||
|
||||
/* Simple helper function to simply output formatted strings to the pty */
|
||||
|
||||
void pty_printf(struct PtyHandle *ph, char *format, ... )
|
||||
{
|
||||
#define PTY_PRINTF_MAXSIZE 512
|
||||
|
||||
va_list args;
|
||||
char tmp[PTY_PRINTF_MAXSIZE+4];
|
||||
|
||||
va_start(args,format);
|
||||
vsnprintf(tmp, PTY_PRINTF_MAXSIZE, format, args);
|
||||
va_end(args);
|
||||
|
||||
pty_write(ph,tmp,strlen(tmp));
|
||||
}
|
||||
Loading…
Reference in New Issue