Silently fail with wrong vde socket dir

[Étienne BERSAC]

Hi,

Using qemu 0.12.5, kvm silently fail with exit code 1 when using -net vde and a wrong path for sock. Actually, the sock option is mean to be the socket dir of the vde_switch, not the socket itself.

With -net vde,sock=/var/run/vde/vde0/ctl , strace ends with the following messages :

connect(7, {sa_family=AF_FILE, path="/var/run/vde/vde0/ctl/ctl"}, 110) = -1 ENOTDIR (Not a directory)
close(7) = 0
close(8) = 0
exit_group(1) = ?
root ~#

Please add a meaningful message.

Regards,
Étienne

[Jes Sorensen (jes-sorensen)]

Hello,

Could you please provide more data, what kinda of system and version are you running on?

Jes

[Michael Tokarev (mjt+launchpad-tls)]

There's no need to add any more specific information. The bug's in the code in qemu.

net/vde.c:

static int net_vde_init(VLANState *vlan, const char *model,
                        const char *name, const char *sock,
                        int port, const char *group, int mode)
{
...
    vde = vde_open(init_sock, (char *)"QEMU", &args);
    if (!vde){
        return -1;
    }
...
}

There's no message generated there. Callers merely pass the failure up the road, where it's finally handled as exit(1). If _anything_ is wrong in vde_open() (which can fail due to variety of reasons, including wrong path to the listening socket and what not), nothing will indicate that, just a trivial, silent exit.

[Jes Sorensen (jes-sorensen)]

Given that you know what the problem is, it would probably have been faster to post a patch than just updating the bug and marking it confirmed....

[Thomas Huth (th-huth)]

A fix for this problem has finally been contributed here:
https://git.qemu.org/?p=qemu.git;a=commitdiff;h=7587855cd23755a7a6bd