Re: [RFC PATCH ghak32 V2 12/13] audit: NETFILTER_PKT: record each container ID associated with a netNS

From: Paul Moore <paul-r2n+y4ga6xFZroRs9YW3xA@public.gmane.org>
To: Richard Guy Briggs <rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: simo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
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	Eric Paris <eparis-FjpueFixGhCM4zKIHC2jIg@public.gmane.org>,
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Subject: Re: [RFC PATCH ghak32 V2 12/13] audit: NETFILTER_PKT: record each container ID associated with a netNS
Date: Wed, 18 Apr 2018 22:10:10 -0400	[thread overview]
Message-ID: <CAHC9VhR3BNRr24BPxud0X_eyFmSxUOh9bwjWNU4Z=rnDR0fENA__46138.2342190065$1524103695$gmane$org@mail.gmail.com> (raw)
In-Reply-To: <66adde01c1dda792aff99a457eea576a0b08ca98.1521179281.git.rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

On Fri, Mar 16, 2018 at 5:00 AM, Richard Guy Briggs <rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> Add container ID auxiliary record(s) to NETFILTER_PKT event standalone
> records.  Iterate through all potential container IDs associated with a
> network namespace.
>
> Signed-off-by: Richard Guy Briggs <rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  kernel/audit.c           |  1 +
>  kernel/auditsc.c         |  2 ++
>  net/netfilter/xt_AUDIT.c | 15 ++++++++++++++-
>  3 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/audit.c b/kernel/audit.c
> index 08662b4..3c77e47 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2102,6 +2102,7 @@ int audit_log_container_info(struct audit_context *context,
>         audit_log_end(ab);
>         return 0;
>  }
> +EXPORT_SYMBOL(audit_log_container_info);
>
>  void audit_log_key(struct audit_buffer *ab, char *key)
>  {
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 208da962..af68d01 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -975,6 +975,7 @@ struct audit_context *audit_alloc_local(void)
>         context->in_syscall = 1;
>         return context;
>  }
> +EXPORT_SYMBOL(audit_alloc_local);
>
>  inline void audit_free_context(struct audit_context *context)
>  {
> @@ -989,6 +990,7 @@ inline void audit_free_context(struct audit_context *context)
>         audit_proctitle_free(context);
>         kfree(context);
>  }
> +EXPORT_SYMBOL(audit_free_context);
>
>  static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>                                  kuid_t auid, kuid_t uid, unsigned int sessionid,
> diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c
> index c502419..edaa456 100644
> --- a/net/netfilter/xt_AUDIT.c
> +++ b/net/netfilter/xt_AUDIT.c
> @@ -71,10 +71,14 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
>  {
>         struct audit_buffer *ab;
>         int fam = -1;
> +       struct audit_context *context = audit_alloc_local();
> +       struct audit_containerid *cont;
> +       int i = 0;
> +       struct net *net;
>
>         if (audit_enabled == 0)
>                 goto errout;

Do I need to say it?  I probably should ... the allocation should
happen after the audit_enabled check.

> -       ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
> +       ab = audit_log_start(context, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
>         if (ab == NULL)
>                 goto errout;
>
> @@ -104,7 +108,16 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
>
>         audit_log_end(ab);
>
> +       net = sock_net(NETLINK_CB(skb).sk);
> +       list_for_each_entry(cont, &net->audit_containerid, list) {
> +               char buf[14];
> +
> +               sprintf(buf, "net%u", i++);
> +               audit_log_container_info(context, buf, cont->id);
> +       }

It seems like this could (should?) be hidden inside an audit function,
e.g. audit_log_net_containers() or something like that.

>  errout:
> +       audit_free_context(context);
>         return XT_CONTINUE;
>  }

-- 
paul moore
www.paul-moore.com