[5/6,RFC] netfilter: add audit operation field

Add the operation performed (register or replace) to the NETFILTER_CFG and
NETFILTER_CFGSOLO records.

Here are sample records for accompanied:
  type=NETFILTER_CFG msg=audit(1494981627.248:9764): op=replace family=7 table=broute entries=0

and unaccompanied cases:
  type=UNKNOWN[1331] msg=audit(1494815998.178:167): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=system_u:system_r:iptables_t:s0 pid=598 comm="ip6tables-resto" exe="/usr/sbin/xtables-multi" op=replace family=10 table=filter entries=4

See: https://github.com/linux-audit/audit-kernel/issues/25

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
 net/bridge/netfilter/ebtables.c |    8 ++++----
 net/netfilter/x_tables.c        |    5 +++--
 2 files changed, 7 insertions(+), 6 deletions(-)

On Thu, May 18, 2017 at 1:21 PM, Richard Guy Briggs <rgb@redhat.com> wrote:
> Add the operation performed (register or replace) to the NETFILTER_CFG and
> NETFILTER_CFGSOLO records.
>
> Here are sample records for accompanied:
>   type=NETFILTER_CFG msg=audit(1494981627.248:9764): op=replace family=7 table=broute entries=0
>
> and unaccompanied cases:
>   type=UNKNOWN[1331] msg=audit(1494815998.178:167): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=system_u:system_r:iptables_t:s0 pid=598 comm="ip6tables-resto" exe="/usr/sbin/xtables-multi" op=replace family=10 table=filter entries=4

A reminder to add new fields to the end of the record.

> See: https://github.com/linux-audit/audit-kernel/issues/25
>
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
>  net/bridge/netfilter/ebtables.c |    8 ++++----
>  net/netfilter/x_tables.c        |    5 +++--
>  2 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
> index 7499232..59b63a8 100644
> --- a/net/bridge/netfilter/ebtables.c
> +++ b/net/bridge/netfilter/ebtables.c
> @@ -1075,7 +1075,7 @@ static int do_replace_finish(struct net *net, struct ebt_replace *repl,
>                         ab = audit_log_start(current->audit_context, GFP_KERNEL,
>                                              AUDIT_NETFILTER_CFG);
>                         if (ab) {
> -                               audit_log_format(ab, "family=%u table=%s entries=%u",
> +                               audit_log_format(ab, "op=replace family=%u table=%s entries=%u",
>                                                  AF_BRIDGE, repl->name,
>                                                  repl->nentries);
>                                 audit_log_end(ab);
> @@ -1085,7 +1085,7 @@ static int do_replace_finish(struct net *net, struct ebt_replace *repl,
>                                              AUDIT_NETFILTER_CFGSOLO);
>                         if (ab) {
>                                 audit_log_task(ab);
> -                               audit_log_format(ab, " family=%u table=%s entries=%u",
> +                               audit_log_format(ab, " op=replace family=%u table=%s entries=%u",
>                                                  AF_BRIDGE, repl->name,
>                                                  repl->nentries);
>                                 audit_log_end(ab);
> @@ -1259,7 +1259,7 @@ struct ebt_table * ebt_register_table(struct net *net,
>                         ab = audit_log_start(current->audit_context, GFP_KERNEL,
>                                              AUDIT_NETFILTER_CFG);
>                         if (ab) {
> -                               audit_log_format(ab, "family=%u table=%s entries=%u",
> +                               audit_log_format(ab, "op=register family=%u table=%s entries=%u",
>                                                  AF_BRIDGE, repl->name,
>                                                  repl->nentries);
>                                 audit_log_end(ab);
> @@ -1269,7 +1269,7 @@ struct ebt_table * ebt_register_table(struct net *net,
>                                              AUDIT_NETFILTER_CFGSOLO);
>                         if (ab) {
>                                 audit_log_task(ab);
> -                               audit_log_format(ab, " family=%u table=%s entries=%u",
> +                               audit_log_format(ab, " op=register family=%u table=%s entries=%u",
>                                                  AF_BRIDGE, repl->name,
>                                                  repl->nentries);
>                                 audit_log_end(ab);
> diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
> index 8d28fff..395ebd3 100644
> --- a/net/netfilter/x_tables.c
> +++ b/net/netfilter/x_tables.c
> @@ -1199,7 +1199,8 @@ struct xt_table_info *xt_replace_table(struct xt_table *table,
>                         ab = audit_log_start(current->audit_context, GFP_KERNEL,
>                                              AUDIT_NETFILTER_CFG);
>                         if (ab) {
> -                               audit_log_format(ab, "family=%u table=%s entries=%u",
> +                               audit_log_format(ab, "op=%s family=%u table=%s entries=%u",
> +                                                private->number ? "replace" : "register",
>                                                  table->af, table->name,
>                                                  private->number);
>                                 audit_log_end(ab);
> @@ -1209,7 +1210,7 @@ struct xt_table_info *xt_replace_table(struct xt_table *table,
>                                              AUDIT_NETFILTER_CFGSOLO);
>                         if (ab) {
>                                 audit_log_task(ab);
> -                               audit_log_format(ab, " family=%u table=%s entries=%u",
> +                               audit_log_format(ab, " op=replace family=%u table=%s entries=%u",
>                                                  table->af, table->name,
>                                                  private->number);
>                                 audit_log_end(ab);
> --
> 1.7.1