[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] give some useful error messages when tap open f
From: |
Kevin Wolf |
Subject: |
Re: [Qemu-devel] [PATCH] give some useful error messages when tap open fails |
Date: |
Fri, 23 Apr 2010 14:46:51 +0200 |
User-agent: |
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 |
Am 22.04.2010 11:52, schrieb Markus Armbruster:
> Michael Tokarev <address@hidden> writes:
>
>> In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints
>> (with fprintf) something like this:
>>
>> warning: could not open /dev/net/tun: no virtual network emulation
>>
>> this has 2 issues:
>> 1) it is not a warning really, it's a fatal error (kvm exits after that),
>> 2) there's no indication as of what's actually wrong: printing errno there
>> is helpful.
>>
>> The patch below removes the "warning" prefix, uses %m (since it's linux,
>> %m is available as format modifier), and changes fprintf() to qemu_error().
>> Now it prints something like this instead:
>>
>> could not configure /dev/net/tun: Device or resource busy
>>
>> (there are 2 messages like that in the same function)
>>
>> This fixes Debian bug #578154, see
>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578154
>>
>> Signed-Off-By: Michael Tokarev <address@hidden>
>>
>> diff --git a/net/tap-linux.c b/net/tap-linux.c
>> index 6af9e82..dbcbe6f 100644
>> --- a/net/tap-linux.c
>> +++ b/net/tap-linux.c
>> @@ -39,7 +39,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
>> int vnet_hdr_required
>>
>> TFR(fd = open("/dev/net/tun", O_RDWR));
>> if (fd < 0) {
>> - fprintf(stderr, "warning: could not open /dev/net/tun: no virtual
>> network emulation\n");
>> + qemu_error("could not open /dev/net/tun: %m\n");
>> return -1;
>> }
>> memset(&ifr, 0, sizeof(ifr));
>
> This might apply to the stable branch (I haven't tried), but I don't
> think it works on master. There, it should look like this (untested):
>
> + error_report("could not open /dev/net/tun: %m");
I'm not sure where this %m is defined exactly (Linux specific? Maybe
BSDs, too?), but it doesn't seem to work with mingw.
Kevin