[PATCH v3 1/4] lxc: refactor lxcNetworkParseData pointers to use new structures

[Daniel P. Berrangé]

On Tue, Jan 28, 2020 at 10:54:08PM -0300, Julio Faracco wrote:
> Struct lxcNetworkParseData is being used as a single pointer which
> iterates through LXC config lines. It means that it will be applied as a
> network each time that a new type appears. After, the same struct is
> used to populate a new network interface. This commit changes this logic
> to multiple lxcNetworkParseData to move this strcuture to an array. It
> makes more sense if we are using indexes to fill interface settings.
> This is better to improve code clarity.
> 
> This commit still introduces *Legacy() functions to keep support of
> network old style definitions.
> 
> Signed-off-by: Julio Faracco <jcfaracco at gmail.com>
> ---
>  src/lxc/lxc_native.c | 129 +++++++++++++++++++++++--------------------
>  1 file changed, 68 insertions(+), 61 deletions(-)
> 
> diff --git a/src/lxc/lxc_native.c b/src/lxc/lxc_native.c
> index dd2345c324..b101848c09 100644
> --- a/src/lxc/lxc_native.c
> +++ b/src/lxc/lxc_native.c

> @@ -702,35 +703,41 @@ static int
>  lxcConvertNetworkSettings(virDomainDefPtr def, virConfPtr properties)
>  {
>      int status;
> -    size_t i;
> -    lxcNetworkParseData data = {def, NULL, NULL, NULL, NULL,
> -                                NULL, NULL, NULL, NULL, 0,
> -                                NULL, NULL, true, 0};
> +    bool privnet = true;
> +    size_t i, j;
> +    lxcNetworkParseDataArray networks = {0, NULL};
> +
> +    networks.parseData = g_new0(lxcNetworkParseDataPtr, 1);
>  
> -    if (virConfWalk(properties, lxcNetworkWalkCallback, &data) < 0)
> +    if (virConfWalk(properties, lxcNetworkWalkCallback, &networks) < 0)
>          goto error;
>  
> +    for (i = 0; i < networks.ndata; i++) {
> +        lxcNetworkParseDataPtr data = networks.parseData[i];
> +        data->def = def;
>  
> -    /* Add the last network definition found */
> -    status = lxcAddNetworkDefinition(&data);
> +        status = lxcAddNetworkDefinition(data);
>  
> -    if (status < 0)
> -        goto error;
> -    else if (status > 0)
> -        data.networks++;
> -    else if (data.type != NULL && STREQ(data.type, "none"))
> -        data.privnet = false;
> +        if (status < 0)
> +            goto error;
> +        else if (data->type != NULL && STREQ(data->type, "none"))
> +            privnet = false;
> +    }
>  
> -    if (data.networks == 0 && data.privnet) {
> +    if (networks.ndata == 0 && privnet) {
>          /* When no network type is provided LXC only adds loopback */
>          def->features[VIR_DOMAIN_FEATURE_PRIVNET] = VIR_TRISTATE_SWITCH_ON;
>      }
>      return 0;
>  
>   error:
> -    for (i = 0; i < data.nips; i++)
> -        VIR_FREE(data.ips[i]);
> -    VIR_FREE(data.ips);
> +    for (i = 0; i < networks.ndata; i++) {
> +        lxcNetworkParseDataPtr data = networks.parseData[i];
> +        for (j = 0; j < data->nips; j++)
> +            VIR_FREE(data->ips[j]);
> +        VIR_FREE(data->ips);
> +    }
> +    VIR_FREE(networks.parseData);
>      return -1;
>  }

Unfortunately I noticed some memory leaks in this method reported by
valgrind

Check it with this:

  ./run valgrind --leak-check=full --show-possibly-lost=no \
      ./tests/lxcconf2xmltest 


Essentially we're not free'ing  networks.parseData in the success
code path, only the failure code path. The failure codepath also
fails to free the 'lxcNetworkParseDataPtr' instance.

Regards,
Daniel
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