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Fix memory leak caused by not freeing memory returned by cgetstr()

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calls. The cost is a little more up-front memory allocation, but the
effect seems minimal.

Problem noticed-by: bde

Added syslog at LOG_ERR when referencing an unknown gettytab entry
and for other cgetent() failues (circular reference et al).

To be merged into 2.2 after a few days testing.
This commit is contained in:
David Nugent 1997-05-11 10:25:38 +00:00
parent aefd026afb
commit 04a59e678a
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=25709
1 changed files with 81 additions and 9 deletions
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90
libexec/getty/subr.c
View file

@ -33,7 +33,7 @@
#ifndef lint
/*static char sccsid[] = "from: @(#)subr.c 8.1 (Berkeley) 6/4/93";*/
static char rcsid[] = "$Id$";
static char rcsid[] = "$Id: subr.c,v 1.9 1997/02/22 14:21:40 peter Exp $";
#endif /* not lint */
/*
@ -46,6 +46,7 @@ static char rcsid[] = "$Id$";
#include <termios.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <syslog.h>
#ifdef DEBUG
#include <stdio.h>
#endif
@ -71,31 +72,101 @@ gettable(name, buf)
register struct gettynums *np;
register struct gettyflags *fp;
long n;
int l;
char *p;
char *msg = NULL;
const char *dba[2];
static int firsttime = 1;
dba[0] = _PATH_GETTYTAB;
dba[1] = 0;
if (cgetent(&buf, dba, name) != 0)
return;
if (firsttime) {
/*
* we need to strdup() anything in the strings array
* initially in order to simplify things later
*/
for (sp = gettystrs; sp->field; sp++)
if (sp->value != NULL) {
/* handle these ones more carefully */
if (sp >= &gettystrs[4] && sp <= &gettystrs[6])
l = 2;
else
l = strlen(sp->value) + 1;
if ((p = malloc(l)) != NULL) {
strncpy(p, sp->value, l);
p[l-1] = '\0';
}
/*
* replace, even if NULL, else we'll
* have problems with free()ing static mem
*/
sp->value = p;
}
firsttime = 0;
}
switch (cgetent(&buf, (char **)dba, (char *)name)) {
case 1:
msg = "%s: couldn't resolve 'tc=' in gettytab '%s'";
case 0:
break;
case -1:
msg = "%s: unknown gettytab entry '%s'";
break;
case -2:
msg = "%s: retrieving gettytab entry '%s': %m";
break;
case -3:
msg = "%s: recursive 'tc=' reference gettytab entry '%s'";
break;
default:
msg = "%s: unexpected cgetent() error for entry '%s'";
break;
}
if (msg != NULL) {
syslog(LOG_ERR, msg, "getty", name);
return;
}
for (sp = gettystrs; sp->field; sp++) {
if ((l = cgetstr(buf, (char*)sp->field, &p)) >= 0) {
if (sp->value) {
/* prefer existing value */
if (strcmp(p, sp->value) != 0)
free(sp->value);
else {
free(p);
p = sp->value;
}
}
sp->value = p;
} else if (l == -1) {
free(sp->value);
sp->value = NULL;
}
}
for (sp = gettystrs; sp->field; sp++)
cgetstr(buf, sp->field, &sp->value);
for (np = gettynums; np->field; np++) {
if (cgetnum(buf, np->field, &n) == -1)
if (cgetnum(buf, (char*)np->field, &n) == -1)
np->set = 0;
else {
np->set = 1;
np->value = n;
}
}
for (fp = gettyflags; fp->field; fp++) {
if (cgetcap(buf, fp->field, ':') == NULL)
if (cgetcap(buf, (char *)fp->field, ':') == NULL)
fp->set = 0;
else {
fp->set = 1;
fp->value = 1 ^ fp->invrt;
}
}
#ifdef DEBUG
printf("name=\"%s\", buf=\"%s\"\r\n", name, buf);
for (sp = gettystrs; sp->field; sp++)
@ -117,7 +188,7 @@ gendefaults()
for (sp = gettystrs; sp->field; sp++)
if (sp->value)
sp->defalt = sp->value;
sp->defalt = strdup(sp->value);
for (np = gettynums; np->field; np++)
if (np->set)
np->defalt = np->value;
@ -137,7 +208,8 @@ setdefaults()
for (sp = gettystrs; sp->field; sp++)
if (!sp->value)
sp->value = sp->defalt;
sp->value = !sp->defalt ? sp->defalt
: strdup(sp->defalt);
for (np = gettynums; np->field; np++)
if (!np->set)
np->value = np->defalt;