freebsd-dev/gnu/libexec/uucp/libunix/cohtty.c
1995-08-19 21:30:30 +00:00

258 lines
7.1 KiB
C

/* Coherent tty locking support. This file was contributed by Bob
Hemedinger <bob@dalek.mwc.com> of Mark Williams Corporation and
lightly edited by Ian Lance Taylor. */
/* The bottom part of this file is lock.c.
* This is a hacked lock.c. A full lock.c can be found in the libmisc sources
* under /usr/src/misc.tar.Z.
*
* These are for checking for the existence of locks:
* lockexist(resource)
* lockttyexist(ttyname)
*/
#include "uucp.h"
#if HAVE_COHERENT_LOCKFILES
/* cohtty.c: Given a serial device name, read /etc/ttys and determine if
* the device is already enabled. If it is, disable the
* device and return a string so that it can be re-enabled
* at the completion of the uucico session as part of the
* function that resets the serial device before uucico
* terminates.
*
*/
#include "uudefs.h"
#include "sysdep.h"
#include <ctype.h>
#include <access.h>
/* fscoherent_disable_tty() is a COHERENT specific function. It takes the name
* of a serial device and then scans /etc/ttys for a match. If it finds one,
* it checks the first field of the entry. If it is a '1', then it will disable
* the port and set a flag. The flag will be checked later when uucico wants to
* reset the serial device to see if the device needs to be re-enabled.
*/
/* May 10, 1993: This function will always return true for the following
* reasons:
* 1) lock files have already been dealt with
* 2) if someone else already has the port open, uucico should fail anyways
* 3) Coherent's disable command return can return '0' or '1', but will
* succeed in any event.
* 4) It doesn't matter if there is a ttys entry for the port in question.
* /etc/ttys generally only lists devices that MAY be enabled for logins.
* If a device will never be used for logins, then there may not be a
* ttys entry, in which case, disable won't be called anyways.
* ---bob@mwc.com
*/
boolean
fscoherent_disable_tty (zdevice, pzenable)
const char *zdevice;
char **pzenable;
{
struct ttyentry{ /* this is an /etc/ttys entry */
char enable_disable[1];
char remote_local[1];
char baud_rate[1];
char tty_device[16];
};
struct ttyentry sought_tty;
int x,y,z; /* dummy */
FILE * infp; /* this will point to /etc/ttys */
char disable_command[66]; /* this will be the disable command
* passed to the system.
*/
char enable_device[16]; /* this will hold our device name
* to enable.
*/
*pzenable = NULL;
strcpy(enable_device,""); /* initialize our strings */
strcpy(sought_tty.tty_device,"");
if( (infp = fopen("/etc/ttys","r")) == NULL){
ulog(LOG_ERROR,"Error: check_disable_tty: failed to open /etc/ttys\n");
return FALSE;
}
while (NULL !=(fgets(&sought_tty, sizeof (sought_tty), infp ))){
sought_tty.tty_device[strlen(sought_tty.tty_device) -1] = '\0';
strcpy(enable_device,sought_tty.tty_device);
/* we must strip away the suffix to the com port name or
* we will never find a match. For example, if we are passed
* /dev/com4l to call out with and the port is already enabled,
* 9/10 the port enabled will be com4r. After we strip away the
* suffix of the port found in /etc/ttys, then we can test
* if the base port name appears in the device name string
* passed to us.
*/
for(z = strlen(sought_tty.tty_device) ; z > 0 ; z--){
if(isdigit(sought_tty.tty_device[z])){
break;
}
}
y = strlen(sought_tty.tty_device);
for(x = z+1 ; x <= y; x++){
sought_tty.tty_device[x] = '\0';
}
/* ulog(LOG_NORMAL,"found device {%s}\n",sought_tty.tty_device); */
if(strstr(zdevice, sought_tty.tty_device)){
if(sought_tty.enable_disable[0] == '1'){
ulog(LOG_NORMAL, "coh_tty: Disabling device %s {%s}\n",
zdevice, sought_tty.tty_device);
sprintf(disable_command, "/etc/disable %s",enable_device);
{
pid_t ipid;
const char *azargs[3];
int aidescs[3];
azargs[0] = "/etc/disable";
azargs[1] = enable_device;
azargs[2] = NULL;
aidescs[0] = SPAWN_NULL;
aidescs[1] = SPAWN_NULL;
aidescs[2] = SPAWN_NULL;
ipid = ixsspawn (azargs, aidescs, TRUE,
FALSE,
(const char *) NULL, TRUE,
TRUE,
(const char *) NULL,
(const char *) NULL,
(const char *) NULL);
if (ipid < 0)
x = 1;
else
x = ixswait ((unsigned long) ipid,
(const char *) NULL);
}
*pzenable = zbufalc (sizeof "/dev/"
+ strlen (enable_device));
sprintf(*pzenable,"/dev/%s", enable_device);
/* ulog(LOG_NORMAL,"Enable string is {%s}",*pzenable); */
return TRUE;
}else{
/* device not enabled */
return TRUE;
}
}
}
return TRUE; /* no ttys entry found */
}
/* The following is COHERENT 4.0 specific. It is used to test for any
* existing lockfiles on a port which would have been created by init
* when a user logs into a port.
*/
#define LOCKSIG 9 /* Significant Chars of Lockable Resources. */
#define LOKFLEN 64 /* Max Length of UUCP Lock File Name. */
#define LOCKPRE "LCK.."
#define PIDLEN 6 /* Maximum length of string representing a pid. */
#ifndef LOCKDIR
#define LOCKDIR SPOOLDIR
#endif
/* There is a special version of DEVMASK for the PE multiport driver
* because of the peculiar way it uses the minor device number. For
* all other drivers, the lower 5 bits describe the physical port--
* the upper 3 bits give attributes for the port.
*/
#define PE_DRIVER 21 /* Major device number for the PE driver. */
#define PE_DEVMASK 0x3f /* PE driver minor device mask. */
#define DEVMASK 0x1f /* Minor device mask. */
/*
* Generates a resource name for locking, based on the major number
* and the lower 4 bits of the minor number of the tty device.
*
* Builds the name in buff as two "." separated decimal numbers.
* Returns NULL on failure, buff on success.
*/
static char *
gen_res_name(path, buff)
char *path;
char *buff;
{
struct stat sbuf;
int status;
if (0 != (status = stat(path, &sbuf))) {
/* Can't stat the file. */
return (NULL);
}
if (PE_DRIVER == major(sbuf.st_rdev)) {
sprintf(buff, "%d.%d", major(sbuf.st_rdev),
PE_DEVMASK & minor(sbuf.st_rdev));
} else {
sprintf(buff, "%d.%d", major(sbuf.st_rdev),
DEVMASK & minor(sbuf.st_rdev));
}
return(buff);
} /* gen_res_name */
/*
* lockexist(resource) char *resource;
*
* Test for existance of a lock on the given resource.
*
* Returns: (1) Resource is locked.
* (0) Resource is not locked.
*/
static boolean
lockexist(resource)
const char *resource;
{
char lockfn[LOKFLEN];
if ( resource == NULL )
return(0);
sprintf(lockfn, "%s/%s%.*s", LOCKDIR, LOCKPRE, LOCKSIG, resource);
return (!access(lockfn, AEXISTS));
} /* lockexist() */
/*
* lockttyexist(ttyname) char *ttyname;
*
* Test for existance of a lock on the given tty.
*
* Returns: (1) Resource is locked.
* (0) Resource is not locked.
*/
boolean
lockttyexist(ttyn)
const char *ttyn;
{
char resource[LOKFLEN];
char filename[LOKFLEN];
sprintf(filename, "/dev/%s", ttyn);
if (NULL == gen_res_name(filename, resource)){
return(0); /* Non-existent tty can not be locked :-) */
}
return(lockexist(resource));
} /* lockttyexist() */
#endif /* HAVE_COHERENT_LOCKFILES */