[PATCH V3] audit: normalize NETFILTER_PKT
Paul Moore
paul at paul-moore.com
Tue Feb 28 22:22:50 UTC 2017
On Sun, Feb 26, 2017 at 3:49 PM, Richard Guy Briggs <rgb at redhat.com> wrote:
> Eliminate flipping in and out of message fields, dropping fields in the process.
>
> Sample raw message format IPv4 UDP:
> type=NETFILTER_PKT msg=audit(1487874761.386:228): mark=0xae8a2732 saddr=127.0.0.1 daddr=127.0.0.1 proto=17^]
> Sample raw message format IPv6 ICMP6:
> type=NETFILTER_PKT msg=audit(1487874761.381:227): mark=0x223894b7 saddr=::1 daddr=::1 proto=58^]
>
> Issue: https://github.com/linux-audit/audit-kernel/issues/11
> Test case: https://github.com/linux-audit/audit-testsuite/issues/43
>
> Signed-off-by: Richard Guy Briggs <rgb at redhat.com>
> ---
> net/netfilter/xt_AUDIT.c | 122 ++++++++++-----------------------------------
> 1 files changed, 27 insertions(+), 95 deletions(-)
>
> diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c
> index 4973cbd..945fa29 100644
> --- a/net/netfilter/xt_AUDIT.c
> +++ b/net/netfilter/xt_AUDIT.c
> @@ -31,146 +31,78 @@ MODULE_ALIAS("ip6t_AUDIT");
...
> -static void audit_ip4(struct audit_buffer *ab, struct sk_buff *skb)
> +static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb)
> {
> struct iphdr _iph;
> const struct iphdr *ih;
>
> ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
It seems like we should be using skb_network_offset(skb) instead of 0
above, yes? Granted, this isn't new, but let's fix it.
> - if (!ih) {
> - audit_log_format(ab, " truncated=1");
> - return;
> - }
> + if (!ih)
> + return false;
>
> - audit_log_format(ab, " saddr=%pI4 daddr=%pI4 ipid=%hu proto=%hhu",
> - &ih->saddr, &ih->daddr, ntohs(ih->id), ih->protocol);
> + audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu",
> + &ih->saddr, &ih->daddr, ih->protocol);
>
> - if (ntohs(ih->frag_off) & IP_OFFSET) {
> - audit_log_format(ab, " frag=1");
> - return;
> - }
> -
> - audit_proto(ab, skb, ih->protocol, ih->ihl * 4);
> + return true;
> }
...
> static unsigned int
> audit_tg(struct sk_buff *skb, const struct xt_action_param *par)
> {
> - const struct xt_audit_info *info = par->targinfo;
> struct audit_buffer *ab;
> + int fam = -1;
>
> if (audit_enabled == 0)
> goto errout;
> -
> ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
> if (ab == NULL)
> goto errout;
>
> - audit_log_format(ab, "action=%hhu hook=%u len=%u inif=%s outif=%s",
> - info->type, par->hooknum, skb->len,
> - par->in ? par->in->name : "?",
> - par->out ? par->out->name : "?");
> -
> - if (skb->mark)
> - audit_log_format(ab, " mark=%#x", skb->mark);
> -
> - if (skb->dev && skb->dev->type == ARPHRD_ETHER) {
> - audit_log_format(ab, " smac=%pM dmac=%pM macproto=0x%04x",
> - eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
> - ntohs(eth_hdr(skb)->h_proto));
> + audit_log_format(ab, "mark=%#x", skb->mark ?: -1);
How do Steve's userspace tools like the unset/-1 value represented
when it is a hex value: -1 or 0xffffffff?
--
paul moore
www.paul-moore.com
More information about the Linux-audit
mailing list