From 8f27486f1987d344c4d9b0de556dfd4209c524bf Mon Sep 17 00:00:00 2001 From: Richard Guy Briggs Date: Wed, 22 Feb 2017 21:50:54 -0500 Subject: [PATCH] audit: normalize NETFILTER_PKT Simplify and eliminate flipping in and out of message fields, relying on nfmark the way we do for audit_key. https://github.com/linux-audit/audit-kernel/issues/11 Signed-off-by: Richard Guy Briggs --- net/netfilter/xt_AUDIT.c | 126 +++++++++++++-------------------------- 1 file changed, 40 insertions(+), 86 deletions(-) diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c index 4973cbddc446bd..05f7f2566c2a99 100644 --- a/net/netfilter/xt_AUDIT.c +++ b/net/netfilter/xt_AUDIT.c @@ -31,146 +31,100 @@ MODULE_ALIAS("ip6t_AUDIT"); MODULE_ALIAS("ebt_AUDIT"); MODULE_ALIAS("arpt_AUDIT"); -static void audit_proto(struct audit_buffer *ab, struct sk_buff *skb, - unsigned int proto, unsigned int offset) -{ - switch (proto) { - case IPPROTO_TCP: - case IPPROTO_UDP: - case IPPROTO_UDPLITE: { - const __be16 *pptr; - __be16 _ports[2]; - - pptr = skb_header_pointer(skb, offset, sizeof(_ports), _ports); - if (pptr == NULL) { - audit_log_format(ab, " truncated=1"); - return; - } - - audit_log_format(ab, " sport=%hu dport=%hu", - ntohs(pptr[0]), ntohs(pptr[1])); - } - break; - - case IPPROTO_ICMP: - case IPPROTO_ICMPV6: { - const u8 *iptr; - u8 _ih[2]; - - iptr = skb_header_pointer(skb, offset, sizeof(_ih), &_ih); - if (iptr == NULL) { - audit_log_format(ab, " truncated=1"); - return; - } - - audit_log_format(ab, " icmptype=%hhu icmpcode=%hhu", - iptr[0], iptr[1]); - - } - break; - } -} +struct nfpkt_par { + int ipv; + const void *saddr; + const void *daddr; + u8 proto; +}; -static void audit_ip4(struct audit_buffer *ab, struct sk_buff *skb) +static void audit_ip4(struct audit_buffer *ab, struct sk_buff *skb, struct nfpkt_par *apar) { struct iphdr _iph; const struct iphdr *ih; + apar->ipv = 4; ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); - if (!ih) { - audit_log_format(ab, " truncated=1"); + if (!ih) return; - } - - audit_log_format(ab, " saddr=%pI4 daddr=%pI4 ipid=%hu proto=%hhu", - &ih->saddr, &ih->daddr, ntohs(ih->id), 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); + apar->saddr = &ih->saddr; + apar->daddr = &ih->daddr; + apar->proto = ih->protocol; } -static void audit_ip6(struct audit_buffer *ab, struct sk_buff *skb) +static void audit_ip6(struct audit_buffer *ab, struct sk_buff *skb, struct nfpkt_par *apar) { struct ipv6hdr _ip6h; const struct ipv6hdr *ih; u8 nexthdr; __be16 frag_off; - int offset; + apar->ipv = 6; ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h); - if (!ih) { - audit_log_format(ab, " truncated=1"); + if (!ih) return; - } nexthdr = ih->nexthdr; - offset = ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), - &nexthdr, &frag_off); + ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off); - audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu", - &ih->saddr, &ih->daddr, nexthdr); - - if (offset) - audit_proto(ab, skb, nexthdr, offset); + apar->saddr = &ih->saddr; + apar->daddr = &ih->daddr; + apar->proto = nexthdr; } 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; + struct nfpkt_par apar = { + -1, NULL, NULL, -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); + audit_log_format(ab, " mark=%#x", skb->mark ?: -1); 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)); - if (par->family == NFPROTO_BRIDGE) { switch (eth_hdr(skb)->h_proto) { case htons(ETH_P_IP): - audit_ip4(ab, skb); + audit_ip4(ab, skb, &apar); break; case htons(ETH_P_IPV6): - audit_ip6(ab, skb); + audit_ip6(ab, skb, &apar); break; } } } - + if (apar.ipv == -1) switch (par->family) { case NFPROTO_IPV4: - audit_ip4(ab, skb); + audit_ip4(ab, skb, &apar); break; case NFPROTO_IPV6: - audit_ip6(ab, skb); + audit_ip6(ab, skb, &apar); break; } -#ifdef CONFIG_NETWORK_SECMARK - if (skb->secmark) - audit_log_secctx(ab, skb->secmark); -#endif + switch (apar.ipv) { + case 4: + audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu", + apar.saddr, apar.daddr, apar.proto); + break; + case 6: + audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu", + apar.saddr, apar.daddr, apar.proto); + break; + default: + audit_log_format(ab, " saddr=? daddr=? proto=-1"); + } audit_log_end(ab);