--- /dev/null
+/*
+ * Creates audit record for dropped/accepted packets
+ *
+ * (C) 2010-2011 Thomas Graf <tgraf@redhat.com>
+ * (C) 2010-2011 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/audit.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/if_arp.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_AUDIT.h>
+#include <linux/netfilter_bridge/ebtables.h>
+#include <net/ipv6.h>
+#include <net/ip.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Thomas Graf <tgraf@redhat.com>");
+MODULE_DESCRIPTION("Xtables: creates audit records for dropped/accepted packets");
+MODULE_ALIAS("ipt_AUDIT");
+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;
+ }
+}
+
+static void 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);
+ if (!ih) {
+ audit_log_format(ab, " truncated=1");
+ 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);
+}
+
+static void audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
+{
+ struct ipv6hdr _ip6h;
+ const struct ipv6hdr *ih;
+ u8 nexthdr;
+ __be16 frag_off;
+ int offset;
+
+ ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
+ if (!ih) {
+ audit_log_format(ab, " truncated=1");
+ return;
+ }
+
+ nexthdr = ih->nexthdr;
+ offset = 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);
+}
+
+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;
+
+ 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));
+
+ if (par->family == NFPROTO_BRIDGE) {
+ switch (eth_hdr(skb)->h_proto) {
+ case htons(ETH_P_IP):
+ audit_ip4(ab, skb);
+ break;
+
+ case htons(ETH_P_IPV6):
+ audit_ip6(ab, skb);
+ break;
+ }
+ }
+ }
+
+ switch (par->family) {
+ case NFPROTO_IPV4:
+ audit_ip4(ab, skb);
+ break;
+
+ case NFPROTO_IPV6:
+ audit_ip6(ab, skb);
+ break;
+ }
+
+#ifdef CONFIG_NETWORK_SECMARK
+ if (skb->secmark)
+ audit_log_secctx(ab, skb->secmark);
+#endif
+
+ audit_log_end(ab);
+
+errout:
+ return XT_CONTINUE;
+}
+
+static unsigned int
+audit_tg_ebt(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ audit_tg(skb, par);
+ return EBT_CONTINUE;
+}
+
+static int audit_tg_check(const struct xt_tgchk_param *par)
+{
+ const struct xt_audit_info *info = par->targinfo;
+
+ if (info->type > XT_AUDIT_TYPE_MAX) {
+ pr_info("Audit type out of range (valid range: 0..%hhu)\n",
+ XT_AUDIT_TYPE_MAX);
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+static struct xt_target audit_tg_reg[] __read_mostly = {
+ {
+ .name = "AUDIT",
+ .family = NFPROTO_UNSPEC,
+ .target = audit_tg,
+ .targetsize = sizeof(struct xt_audit_info),
+ .checkentry = audit_tg_check,
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "AUDIT",
+ .family = NFPROTO_BRIDGE,
+ .target = audit_tg_ebt,
+ .targetsize = sizeof(struct xt_audit_info),
+ .checkentry = audit_tg_check,
+ .me = THIS_MODULE,
+ },
+};
+
+static int __init audit_tg_init(void)
+{
+ return xt_register_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
+}
+
+static void __exit audit_tg_exit(void)
+{
+ xt_unregister_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
+}
+
+module_init(audit_tg_init);
+module_exit(audit_tg_exit);
Code Review / kvmfornfv.git / blobdiff