Bug in ppp_async.c

I found a bug in the 2.4.1-pre10 version of ppp_async.c

In fact, a lot of ioctl are not supported any more, whih make the pppd start fail.
The bad patch is:

diff -u --recursive --new-file v2.4.0/linux/drivers/net/ppp_async.c linux/drivers/net/ppp_async.c

@@ -259,25 +244,6 @@
   err = 0;
   break;
 
-/*
- * For now, do the same as the old 2.3 driver useta
- */
- case PPPIOCGFLAGS:
- case PPPIOCSFLAGS:
- case PPPIOCGASYNCMAP:
- case PPPIOCSASYNCMAP:
- case PPPIOCGRASYNCMAP:
- case PPPIOCSRASYNCMAP:
- case PPPIOCGXASYNCMAP:
- case PPPIOCSXASYNCMAP:
- case PPPIOCGMRU:
- case PPPIOCSMRU:
-  err = -EPERM;
-  if (!capable(CAP_NET_ADMIN))
-   break;
-  err = ppp_async_ioctl(&ap->chan, cmd, arg);
-  break;
-
  case PPPIOCATTACH:
  case PPPIOCDETACH:
   err = ppp_channel_ioctl(&ap->chan, cmd, arg);

When I apply this patch back, I got the connection, but it fail after a few seconds...
In fact, there are two other patches to reverse in order to make the driver do its job again (sure it does: I'm using this kind of kernel now...):

diff -u --recursive --new-file v2.4.0/linux/drivers/net/ppp_async.c linux/drivers/net/ppp_async.c

@@ -181,12 +175,7 @@
 ppp_asynctty_read(struct tty_struct *tty, struct file *file,
     unsigned char *buf, size_t count)
 {
- /* For now, do the same as the old 2.3.x code useta */
- struct asyncppp *ap = tty->disc_data;
-
- if (ap == 0)
-  return -ENXIO;
- return ppp_channel_read(&ap->chan, file, buf, count);
+ return -EAGAIN;
 }
 
 /*

Then:

diff -u --recursive --new-file v2.4.0/linux/drivers/net/ppp_async.c linux/drivers/net/ppp_async.c

@@ -203,12 +193,7 @@
 ppp_asynctty_write(struct tty_struct *tty, struct file *file,
      const unsigned char *buf, size_t count)
 {
- /* For now, do the same as the old 2.3.x code useta */
- struct asyncppp *ap = tty->disc_data;
-
- if (ap == 0)
-  return -ENXIO;
- return ppp_channel_write(&ap->chan, buf, count);
+ return -EAGAIN;
 }
 
 static int

Without these modifications, everything is allright !

Jocelyn Mayer

PS: sorry, but I don't know who is the actual maitainer of this
driver... ý:.žË›±Êâmçë¢kaŠÉb²ßìzwm…éb�ïîžË›±Êâmébžìÿ‘êçz_âžØ^n‡r¡ö¦zË�ëh™¨è­Ú&£ûàz¿äz¹Þ—ú+€ù^jÇ«y§m…á@A«a¶Úÿÿü0ÃûnÇú+ƒùd

I'll bet you're using an old pppd. You need version 2.4.0 of pppd, available from ftp://linuxcare.com.au/pub/ppp/, as documented in the Documentation/Changes file.

Me.

Paul Mackerras, Open Source Research Fellow, Linuxcare, Inc.
+61 2 6262 8990 tel, +61 2 6262 8991 fax
[email protected], http://www.linuxcare.com.au/
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Even Red Hat 7 only has the 2.3.11 version.

The 2.4.xx series is supposed to be stable. If there is any way you could add a compatibility hack, please do so.
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That's probably because Red Hat 7 didn't ship with a 2.4.0 kernel.

The 2.4.0 Documentation/Changes file already said that pppd should be at least v2.4.0. That hasn't changed, AFAICT.

dwmw2


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Stable != backwards compatible to the year dot. ppp-2.4.0 has been out for over 5 months now. Adding the compatibility stuff back in would make the PPP subsystem much more complicated and less robust. And pppd is not the only thing you would have to upgrade if you are using a 2.4.0 with Red Hat 7.0 - I would expect that you would also at least have to upgrade modutils, and switch over from ipchains to iptables if you use the netfilter stuff.

Paul.

Paul Mackerras, Open Source Research Fellow, Linuxcare, Inc.
+61 2 6262 8990 tel, +61 2 6262 8991 fax
[email protected], http://www.linuxcare.com.au/
Linuxcare.  Support for the revolution.
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I know. It means that you don't break the API between 2.4.0 and 2.4.1 though. It means you don't break distributions that were supposed to be ready for the 2.4.xx kernels.

That is less than the typical time between releases of a normal Linux distribution.

I wouldn't be asking you to add it back if you hadn't removed it. It was already there.

I don't trust that the new version will be a drop-in replacement due to past experiences, and I wonder if my 2.0.xx kernel will still be supported by the new user-space code. So this sucks.

Nope, the network people even offer some Linux 2.0 compatibility. That dates back many years! Hey, I like your example.

For modutils, there was a security problem anyway.
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I do ppp using 2.4.0 w/ redhat 7 now, no upgrades besides modultils and the kernel :>
-- Dan Egli
-- Network Administrator / President
-- Frankenstein Computers
-- 801-671-7875
----- Original Message -----
From: "Paul Mackerras" <[email protected]>
To: "Albert D. Cahalan" <[email protected]>
Cc: <[email protected]>; <[email protected]>; <[email protected]>; <[email protected]>
Sent: Wednesday, January 24, 2001 2:45 AM
Subject: Re: Bug in ppp_async.c

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