diff options
Diffstat (limited to 'net/netfilter/xt_AUDIT.c')
| -rw-r--r-- | net/netfilter/xt_AUDIT.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c new file mode 100644 index 000000000..b6a015aee --- /dev/null +++ b/net/netfilter/xt_AUDIT.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Creates audit record for dropped/accepted packets + * + * (C) 2010-2011 Thomas Graf <tgraf@redhat.com> + * (C) 2010-2011 Red Hat, Inc. +*/ + +#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 bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb) +{ + struct iphdr _iph; + const struct iphdr *ih; + + ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph); + if (!ih) + return false; + + audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu", + &ih->saddr, &ih->daddr, ih->protocol); + + return true; +} + +static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb) +{ + struct ipv6hdr _ip6h; + const struct ipv6hdr *ih; + u8 nexthdr; + __be16 frag_off; + + ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h); + if (!ih) + return false; + + nexthdr = ih->nexthdr; + 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); + + return true; +} + +static unsigned int +audit_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + struct audit_buffer *ab; + int fam = -1; + + if (audit_enabled == AUDIT_OFF) + goto errout; + ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT); + if (ab == NULL) + goto errout; + + audit_log_format(ab, "mark=%#x", skb->mark); + + switch (xt_family(par)) { + case NFPROTO_BRIDGE: + switch (eth_hdr(skb)->h_proto) { + case htons(ETH_P_IP): + fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; + break; + case htons(ETH_P_IPV6): + fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; + break; + } + break; + case NFPROTO_IPV4: + fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1; + break; + case NFPROTO_IPV6: + fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1; + break; + } + + if (fam == -1) + audit_log_format(ab, " saddr=? daddr=? proto=-1"); + + 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_ratelimited("Audit type out of range (valid range: 0..%u)\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); |