Re: rename ppp interface

[Arvin Schnell <arvin@suse.de>]

On Wed, Jul 21, 2004 at 05:54:59PM +0400, Michael Tokarev wrote:
> Arvin Schnell wrote:
> []
> >--- ./pppd/options.c.orig	2004-07-19 12:59:21.000000000 +0000
> >+++ ./pppd/options.c	2004-07-19 14:35:04.253865964 +0000
> >+    { "ifname", o_string, req_ifname,
> >+      "Set PPP interface name",
> >+      OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXIFNAMELEN },
> 
> Is there any reason to use new option instead of existing
> "linkname" option?  Currently, linkname is used only for
> informational purposes (to be passed into scripts, and to
> create /var/run/ppp-$linkname.pid file).  Existing option
> seems to be better, but it may lead to unexpected problems,
> namely, users who use it expects to see interface named pppN
> (with current version), but with this change things may change
> too.

In the end the "linkname" option could be used but in a patch I
prefer to not change the existing behaviour.

> >--- ./pppd/sys-linux.c.orig	2004-07-19 12:33:29.000000000 +0000
> >+++ ./pppd/sys-linux.c	2004-07-19 14:37:36.463754450 +0000
> >@@ -649,6 +649,21 @@
> > 	}
> > 	if (x < 0)
> > 		error("Couldn't create new ppp unit: %m");
> >+
> >+	if (x = 0 && req_ifname[0] != '\0') {
> >+		struct ifreq ifr;
> >+		char t[MAXIFNAMELEN];
> >+		memset(&ifr, 0, sizeof(struct ifreq));
> >+		slprintf(t, sizeof(t), "%s%d", PPP_DRV_NAME, ifunit);
> >+		strncpy(ifr.ifr_name, t, IF_NAMESIZE);
> >+		strncpy(ifr.ifr_newname, req_ifname, IF_NAMESIZE);
> >+		x = ioctl(sock_fd, SIOCSIFNAME, &ifr);
> >+		if (x < 0)
> >+		    error("Couldn't rename interface %s to %s: %m", t, 
> >req_ifname);
> 
> I'd suggest to change this into warn().

The goal is to get persistent interface names.  I suppose some
people will prefer a failure instead of a random interface name
to prevent a interface not covert by the firewall.

Anyway, if it's changed to warn the code in set_ifunit must also
be changed.

> >+		else
> >+		    info("Renamed interface %s to %s", t, req_ifname);
> 
> Is such a verbosity really necessary?  Pppd is already too noizy...

It was useful during development but can of course be removed.
There's already the "using interface xxx" message.

ciao Arvin

-- 
Dipl.-Phys. Arvin Schnell
SUSE Linux AG
Research & Development
email: arvin@suse.de