Date: Tue, 17 Apr 2001 02:22:23 -0700 From: Dima Dorfman <dima@unixfreak.org> To: Brian Somers <brian@Awfulhak.org> Cc: hackers@FreeBSD.ORG Subject: Re: Patch to make snp(4) devfs-friendly Message-ID: <20010417092223.9AC973E09@bazooka.unixfreak.org> In-Reply-To: <200104170905.f3H95lr61736@hak.lan.Awfulhak.org>; from brian@Awfulhak.org on "Tue, 17 Apr 2001 10:05:47 %2B0100"
next in thread | previous in thread | raw e-mail | index | archive | help
Brian Somers <brian@Awfulhak.org> writes:
> I haven't actually tested the code, but looking at the patch, I think
> there's a problem with it...
>
> Specifically, on a non-devfs system - where the device nodes are
> created with mknod(1), snp_clone() isn't going to be called before
> snpopen().
>
> I've (ab)used drv2 as a flag to say whether make_dev() has been
> called in net/if_tun.c, but I'm not sure if this is the right answer
> either :*]
I think the correct approach is to check for !(si_flags & SI_NAMED) as
done in rev. 1.68 of sys/net/bpf.c (that rev. has a precedence bug,
which has since been fixed). That was written by phk, who I take to
be pretty authoritative on the subject; looking at the places SI_NAMED
is used also supports this conclusion.
A corrected patch is attached (although I didn't test it in the
non-devfs case).
Thanks!
Dima Dorfman
dima@unixfreak.org
Index: tty_snoop.c
===================================================================
RCS file: /st/src/FreeBSD/src/sys/kern/tty_snoop.c,v
retrieving revision 1.52
diff -u -r1.52 tty_snoop.c
--- tty_snoop.c 2001/03/26 12:41:01 1.52
+++ tty_snoop.c 2001/04/17 09:16:52
@@ -287,10 +287,10 @@
return (error);
if (dev->si_drv1 == NULL) {
- int mynor = minor(dev);
-
+ if (!(dev->si_flags & SI_NAMED))
+ make_dev(&snp_cdevsw, minor(dev), UID_ROOT, GID_WHEEL,
+ 0600, "snp%d", dev2unit(dev));
dev->si_drv1 = snp = malloc(sizeof(*snp), M_SNP, M_WAITOK|M_ZERO);
- make_dev(&snp_cdevsw, mynor, 0, 0, 0600, "snp%d", mynor);
} else
return (EBUSY);
@@ -365,6 +365,7 @@
free(snp->snp_buf, M_SNP);
snp->snp_flags &= ~SNOOP_OPEN;
dev->si_drv1 = NULL;
+ destroy_dev(dev);
return (snp_detach(snp));
}
@@ -505,10 +506,25 @@
static void snp_drvinit __P((void *unused));
static void
+snp_clone(void *arg, char *name, int namelen, dev_t *dev)
+{
+ int u;
+
+ if (*dev != NODEV)
+ return;
+ if (dev_stdclone(name, NULL, "snp", &u) != 1)
+ return;
+ *dev = make_dev(&snp_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600,
+ "snp%d", u);
+ return;
+}
+
+static void
snp_drvinit(unused)
void *unused;
{
+ EVENTHANDLER_REGISTER(dev_clone, snp_clone, 0, 1000);
cdevsw_add(&snp_cdevsw);
}
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010417092223.9AC973E09>