[linux-yocto] [PATCH v2] ipv4: net namespace does not inherit network configurations

[Bruce Ashfield]

Looks fine to me.

And to confirm, this is for 4.18, correct ?

Bruce

On 2018-10-28 10:24 PM, zhe.he at windriver.com wrote:
> From: He Zhe <zhe.he at windriver.com>
> 
> patch from https://lkml.org/lkml/2014/7/29/119
> 
> Ipv4 net namespace requires a similar logic change as commit a79ca223e029
> [ipv6: fix bad free of addrconf_init_net] introduces for newer kernels.
> 
> Since a net namespace is independent to another. That is, there
> is no any relationship between the net namespaces. So a new net
> namespace should not inherit network configurations from another
> net namespace including the host.
> 
> CC: Hong Zhiguo <honkiko at gmail.com>
> CC: David S. Miller <davem at davemloft.net>
> Signed-off-by: Zhu Yanjun <zyjzyj2000 at gmail.com>
> Signed-off-by: yzhu1 <yanjun.zhu at windriver.com>
> 
> The patch was submitted upstream (https://lkml.org/lkml/2014/7/29/119), but
> did not get any significant discussion and was not rejected, and also was
> not merged. It still makes sense for Yocto linux kernel.
> 
> Signed-off-by: He Zhe <zhe.he at windriver.com>
> ---
> v2: Add summary about the status of the patch
> 
> This is for linux-yocto-dev, linux-yocto master and 4.18 branches.
> 
>   net/ipv4/devinet.c | 29 ++++++++++++-----------------
>   1 file changed, 12 insertions(+), 17 deletions(-)
> 
> diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
> index a34602a..8df4a72 100644
> --- a/net/ipv4/devinet.c
> +++ b/net/ipv4/devinet.c
> @@ -2560,28 +2560,23 @@ static __net_init int devinet_init_net(struct net *net)
>   #endif
>   
>   	err = -ENOMEM;
> -	all = &ipv4_devconf;
> -	dflt = &ipv4_devconf_dflt;
> +	all = kmemdup(&ipv4_devconf, sizeof(ipv4_devconf), GFP_KERNEL);
> +	if (all == NULL)
> +		goto err_alloc_all;
>   
> -	if (!net_eq(net, &init_net)) {
> -		all = kmemdup(all, sizeof(ipv4_devconf), GFP_KERNEL);
> -		if (!all)
> -			goto err_alloc_all;
> -
> -		dflt = kmemdup(dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL);
> -		if (!dflt)
> -			goto err_alloc_dflt;
> +	dflt = kmemdup(&ipv4_devconf_dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL);
> +	if (dflt == NULL)
> +		goto err_alloc_dflt;
>   
>   #ifdef CONFIG_SYSCTL
> -		tbl = kmemdup(tbl, sizeof(ctl_forward_entry), GFP_KERNEL);
> -		if (!tbl)
> -			goto err_alloc_ctl;
> +	tbl = kmemdup(tbl, sizeof(ctl_forward_entry), GFP_KERNEL);
> +	if (tbl == NULL)
> +		goto err_alloc_ctl;
>   
> -		tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1];
> -		tbl[0].extra1 = all;
> -		tbl[0].extra2 = net;
> +	tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1];
> +	tbl[0].extra1 = all;
> +	tbl[0].extra2 = net;
>   #endif
> -	}
>   
>   #ifdef CONFIG_SYSCTL
>   	err = __devinet_sysctl_register(net, "all", NETCONFA_IFINDEX_ALL, all);
>