When userland was massaged for pledge(), I hesitated using the
"manually call tzset()" approach for handling things. It felt
too low-level to call tzset(), an API almost noone knows the
existance of.
Arriving in the same situation to satisfy unveil(). Again calling
tzset() feels too unfamiliar and low level.
Regarding the comment in your diff, it says "localtime", but what is
actually called is ctime(), which calls localtime() (which calls
tzset(), which is where the unveil-files-missing or pledge-whatver
issues would show up in some programs). Probably should adjust
the comment
Here's the later troublesome chunk:
if (special & BOOTTIME) {
struct timeval *btp = (struct timeval *)buf;
time_t boottime;
if (!nflag) {
boottime = btp->tv_sec;
(void)printf("%s%s%s", string, equ, ctime(&boottime));
That makes me wonder, can we be less obtuse up front, and
prime the subsystem before unveil by calling the same function which
will be called later?
Something like this. It feels slightly better to me.
Index: sysctl.c
===================================================================
RCS file: /cvs/src/sbin/sysctl/sysctl.c,v
retrieving revision 1.242
diff -u -p -u -r1.242 sysctl.c
--- sysctl.c 13 May 2019 20:47:19 -0000 1.242
+++ sysctl.c 8 Jun 2019 16:33:07 -0000
@@ -162,6 +162,8 @@ struct list secondlevel[] = {
int Aflag, aflag, nflag, qflag;
+time_t boottime;
+
/*
* Variables requiring special processing.
*/
@@ -255,6 +257,12 @@ main(int argc, char *argv[])
argc -= optind;
argv += optind;
+ ctime(&boottime); /* satisfy potential $TZ expansion before unveil() */
+
+ if (unveil("/dev", "r") == -1)
+ err(1, "unveil");
+ if (unveil(NULL, NULL) == -1)
+ err(1, "unveil");
if (argc == 0 || (Aflag || aflag)) {
debuginit();
vfsinit();
@@ -893,7 +901,6 @@ parse(char *string, int flags)
}
if (special & BOOTTIME) {
struct timeval *btp = (struct timeval *)buf;
- time_t boottime;
if (!nflag) {
boottime = btp->tv_sec;
Florian Obser <[email protected]> wrote:
> On Fri, Jun 07, 2019 at 11:24:30PM +0100, Ricardo Mestre wrote:
> > i did that and for some for reason i didn't get it! it tries to open
> > timezone so it kinda looks like a red flag right there...
> >
> > apart from /dev do we need to look into TZ on this one as well? if TZ
> > var needs to be looked at then all bets are off :/
>
> this seems to do the right thing:
>
> diff --git sysctl.c sysctl.c
> index dc6abc16670..c74e706942a 100644
> --- sysctl.c
> +++ sysctl.c
> @@ -255,6 +255,13 @@ main(int argc, char *argv[])
> argc -= optind;
> argv += optind;
>
> + tzset(); /* for kern.boottime in localtime */
> +
> + if (unveil("/dev", "r") == -1)
> + err(1, "unveil");
> + if (unveil(NULL, NULL) == -1)
> + err(1, "unveil");
> +
> if (argc == 0 || (Aflag || aflag)) {
> debuginit();
> vfsinit();
>
>
> --
> I'm not entirely sure you are real.
>
