Re: git: 2c24ad3377a6 - main - ifconfig: abort if loading a module fails other than for ENOENT

On Mon, Jan 9, 2023, at 15:57, Alan Somers wrote:
> The branch main has been updated by asomers:
>
> URL: 
> https://cgit.FreeBSD.org/src/commit/?id=2c24ad3377a6f584e484656db8390e4eb7cfc119
>
> commit 2c24ad3377a6f584e484656db8390e4eb7cfc119
> Author:     Alan Somers <asomers@FreeBSD.org>
> AuthorDate: 2022-12-26 02:06:21 +0000
> Commit:     Alan Somers <asomers@FreeBSD.org>
> CommitDate: 2023-01-10 02:56:18 +0000
>
>     ifconfig: abort if loading a module fails other than for ENOENT
>    
>     If "ifconfig create" tries to load a kernel module, and the module
>     exists but can't be loaded, fail the command with a useful error
>     message.  This is helpful, for example, when trying to create a cloned
>     interface in a vnet jail.  But ignore ENOENT, because sometimes ifconfig
>     can't correctly guess the name of the required kernel module.
>    
>     MFC after:      2 weeks
>     Reviewed by:    jhb
>     Differential Revision: https://reviews.freebsd.org/D37873
> ---
>  sbin/ifconfig/ifconfig.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/sbin/ifconfig/ifconfig.c b/sbin/ifconfig/ifconfig.c
> index 462d543125c4..120207a6927e 100644
> --- a/sbin/ifconfig/ifconfig.c
> +++ b/sbin/ifconfig/ifconfig.c
> @@ -1719,11 +1719,19 @@ ifmaybeload(const char *name)
>  		}
>  	}
> 
> -	/*
> -	 * Try to load the module.  But ignore failures, because ifconfig can't
> -	 * infer the names of all drivers (eg mlx4en(4)).
> -	 */
> -	(void) kldload(ifkind);
> +	/* Try to load the module. */
> +	if (kldload(ifkind) < 0) {
> +		switch (errno) {
> +		case ENOENT:
> +			/*
> +			 * Ignore ENOENT, because ifconfig can't infer the
> +			 * names of all drivers (eg mlx4en(4)).
> +			 */
> +			break;
> +		default:
> +			err(1, "kldload(%s)", ifkind);
> +		}
> +	}
>  }
> 
>  static struct cmd basic_cmds[] = {


Hi.

I have a jail with vnet where the interface is renamed that stopped working after this.

from inside the jail:

root@test:/ # ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
        options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
        inet6 ::1 prefixlen 128
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x10
        inet 127.0.0.1 netmask 0xff000000
        groups: lo
        nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
vnet0b_test: flags=8862<BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=8<VLAN_MTU>
        ether 02:27:72:a7:28:0b
        groups: epair
        media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
        status: active
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>

root@test:/ # ifconfig vnet0b_test
ifconfig: kldload(if_vnet): Operation not permitted


If I don't rename the interface, that works.

jail.conf:

test {
    vnet;
    $index = "0";
    vnet.interface = "vnet${index}b_${name}";
    exec.prestart += "ifconfig epair${index} create";
    exec.prestart += "ifconfig ${bridge} addm epair${index}a";
    exec.prestart += "ifconfig epair${index}a up name vnet${index}a_${name}";
    exec.prestart += "ifconfig epair${index}b up name vnet${index}b_${name}";
    exec.poststop += "ifconfig ${bridge} deletem vnet${index}a_${name}";
    exec.poststop += "ifconfig vnet${index}a_${name} destroy";
    devfs_ruleset = "11"; # add path 'bpf*' unhide (devfs.rules)
}

That's a bit odd, I know, could be using description instead.

Just reporting.

Regards.
--
Danilo G. Baio