Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 | /*
* 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);
|