dave@onfcanim.UUCP (12/03/87)
The set of patches to uucp recently posted by Rick Adams contained lots of
good fixes; unfortunately they seem to have introduced one new bug.
It's not really his fault - Acuopn() was rather convoluted.
Here is a modifcation to make it really do what I think the original
author intended, with Rick's change included.
Subject: Acuopn() has several bugs.
Index: usr.bin/uucp/condevs.c 4.3BSD
Description:
Acuopn counted a locked line as part of the limit of TRYCALLS
attempts. Rick Adams posted a fix for this, but his fix would
generate the log message "NO DEVICE" when the problem was
really that all lines are locked.
If the condevs table contains no entry matching the "method"
and "brand" of the ACU specified in the L-devices table, it
doesn't detect the fact that it didn't find a match. This probably
dereferences a null pointer when it tries calling.
There is code to print out an unsupported ACU type in L-devices,
but only when it doesn't find any other supported type. This code
never works anyway, due to the previous bug.
Repeat-By:
Read the code. Some of these conditions can be demonstrated
by corrupting the "brand" field in the L-devices file, and
by trying calls when the available lines are locked by tip or
other uucico's.
Fix:
The real problem is that someone tried to be too clever, using
a single variable "acustatus" to keep track of whether an ACU
was found and how many call attempts have been made. Changing
the code challenges your sanity.
Separate the functions of "acustatus" into two variables.
Check for unsuccessful search of condevs table.
Print out unsupported ACU types as found, not later sometimes.
The following patch should be applied to the original 4.3BSD code
as distributed. If you've already applied Rick Adams' fix, and
don't use RCS or SCCS, hand examination of the diff should show
what to do, since Rick's change was really only 1 line.
*** /tmp/,RCSt1013708 Wed Dec 2 18:34:51 1987
--- condevs.c Wed Dec 2 18:34:02 1987
***************
*** 1,9 ****
/*
* $Log: condevs.c,v $
* Revision 1.2 87/05/28 16:07:30 root
* Added Vadic 2400 entry.
*
! * $Header: condevs.c,v 1.2 87/05/28 16:07:30 root Exp $
*/
#ifndef lint
--- 1,13 ----
/*
* $Log: condevs.c,v $
+ * Revision 1.3 87/12/02 18:33:18 dave
+ * General cleanup of Acuopn(); several bugs fixed.
+ * A locked line no longer counts in the limit of TRYCALLS call attempts.
+ *
* Revision 1.2 87/05/28 16:07:30 root
* Added Vadic 2400 entry.
*
! * $Header: condevs.c,v 1.3 87/12/02 18:33:18 dave Exp $
*/
#ifndef lint
***************
*** 279,289 ****
{
char phone[MAXPH+1];
register struct condev *cd;
! register int fd, acustatus;
register FILE *dfp;
struct Devices dev;
int retval = CF_NODEV;
! char nobrand[MAXPH], *line;
exphone(flds[F_PHONE], phone);
if (snccmp(flds[F_LINE], "LOCAL") == SAME)
--- 283,294 ----
{
char phone[MAXPH+1];
register struct condev *cd;
! register int fd, ntries;
! int acufound;
register FILE *dfp;
struct Devices dev;
int retval = CF_NODEV;
! char *line;
exphone(flds[F_PHONE], phone);
if (snccmp(flds[F_LINE], "LOCAL") == SAME)
***************
*** 291,302 ****
else
line = flds[F_LINE];
devSel[0] = '\0';
- nobrand[0] = '\0';
DEBUG(4, "Dialing %s\n", phone);
dfp = fopen(DEVFILE, "r");
ASSERT(dfp != NULL, "Can't open", DEVFILE, 0);
! acustatus = 0; /* none found, none locked */
while (rddev(dfp, &dev) != FAIL) {
/*
* for each ACU L.sys line, try at most twice
--- 296,307 ----
else
line = flds[F_LINE];
devSel[0] = '\0';
DEBUG(4, "Dialing %s\n", phone);
dfp = fopen(DEVFILE, "r");
ASSERT(dfp != NULL, "Can't open", DEVFILE, 0);
! acufound = 0;
! ntries = 0;
while (rddev(dfp, &dev) != FAIL) {
/*
* for each ACU L.sys line, try at most twice
***************
*** 308,314 ****
* To try 'harder' to connect to a remote site,
* use multiple L.sys entries.
*/
! if (acustatus > TRYCALLS)
break;
if (strcmp(flds[F_CLASS], dev.D_class) != SAME)
continue;
--- 313,319 ----
* To try 'harder' to connect to a remote site,
* use multiple L.sys entries.
*/
! if (ntries > TRYCALLS)
break;
if (strcmp(flds[F_CLASS], dev.D_class) != SAME)
continue;
***************
*** 319,337 ****
continue;
}
for(cd = condevs; cd->CU_meth != NULL; cd++) {
! if (snccmp(line, cd->CU_meth) == SAME) {
! if (snccmp(dev.D_brand, cd->CU_brand) == SAME)
! break;
! strncpy(nobrand, dev.D_brand, sizeof nobrand);
! }
}
!
! if (mlock(dev.D_line) == FAIL) {
! acustatus++;
continue;
}
! if (acustatus < 1)
! acustatus = 1; /* has been found */
#ifdef DIALINOUT
#ifdef ALLACUINOUT
if (1) {
--- 324,342 ----
continue;
}
for(cd = condevs; cd->CU_meth != NULL; cd++) {
! if (snccmp(line, cd->CU_meth) == SAME &&
! snccmp(dev.D_brand, cd->CU_brand) == SAME)
! break;
}
! if (cd->CU_meth == NULL) {
! logent(dev.D_brand, "unsupported ACU type");
continue;
}
! acufound = 1;
!
! if (mlock(dev.D_line) == FAIL)
! continue;
!
#ifdef DIALINOUT
#ifdef ALLACUINOUT
if (1) {
***************
*** 347,353 ****
#endif DIALINOUT
DEBUG(4, "Using %s\n", cd->CU_brand);
! acustatus++;
fd = (*(cd->CU_open))(phone, flds, &dev);
if (fd > 0) {
CU_end = cd->CU_clos; /* point CU_end at close func */
--- 352,358 ----
#endif DIALINOUT
DEBUG(4, "Using %s\n", cd->CU_brand);
! ntries++;
fd = (*(cd->CU_open))(phone, flds, &dev);
if (fd > 0) {
CU_end = cd->CU_clos; /* point CU_end at close func */
***************
*** 359,371 ****
retval = CF_DIAL;
}
fclose(dfp);
! if (acustatus == 0) {
! if (nobrand[0])
! logent(nobrand, "unsupported ACU type");
! else
! logent("L-devices", "No appropriate ACU");
! }
! if (acustatus == 1)
logent("DEVICE", "NO");
return retval;
}
--- 364,372 ----
retval = CF_DIAL;
}
fclose(dfp);
! if (!acufound)
! logent("L-devices", "No appropriate ACU");
! else if (ntries == 0)
logent("DEVICE", "NO");
return retval;
}