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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Creates audit record for dropped/accepted packets
4 *
5 * (C) 2010-2011 Thomas Graf <tgraf@redhat.com>
6 * (C) 2010-2011 Red Hat, Inc.
7*/
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/audit.h>
12#include <linux/module.h>
13#include <linux/skbuff.h>
14#include <linux/tcp.h>
15#include <linux/udp.h>
16#include <linux/if_arp.h>
17#include <linux/netfilter/x_tables.h>
18#include <linux/netfilter/xt_AUDIT.h>
19#include <linux/netfilter_bridge/ebtables.h>
20#include <net/ipv6.h>
21#include <net/ip.h>
22
23MODULE_LICENSE("GPL");
24MODULE_AUTHOR("Thomas Graf <tgraf@redhat.com>");
25MODULE_DESCRIPTION("Xtables: creates audit records for dropped/accepted packets");
26MODULE_ALIAS("ipt_AUDIT");
27MODULE_ALIAS("ip6t_AUDIT");
28MODULE_ALIAS("ebt_AUDIT");
29MODULE_ALIAS("arpt_AUDIT");
30
31static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb)
32{
33 struct iphdr _iph;
34 const struct iphdr *ih;
35
36 ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_iph), &_iph);
37 if (!ih)
38 return false;
39
40 audit_log_format(ab, " saddr=%pI4 daddr=%pI4 proto=%hhu",
41 &ih->saddr, &ih->daddr, ih->protocol);
42
43 return true;
44}
45
46static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
47{
48 struct ipv6hdr _ip6h;
49 const struct ipv6hdr *ih;
50 u8 nexthdr;
51 __be16 frag_off;
52
53 ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
54 if (!ih)
55 return false;
56
57 nexthdr = ih->nexthdr;
58 ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h), &nexthdr, &frag_off);
59
60 audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu",
61 &ih->saddr, &ih->daddr, nexthdr);
62
63 return true;
64}
65
66static unsigned int
67audit_tg(struct sk_buff *skb, const struct xt_action_param *par)
68{
69 struct audit_buffer *ab;
70 int fam = -1;
71
72 if (audit_enabled == AUDIT_OFF)
73 goto errout;
74 ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
75 if (ab == NULL)
76 goto errout;
77
78 audit_log_format(ab, "mark=%#x", skb->mark);
79
80 switch (xt_family(par)) {
81 case NFPROTO_BRIDGE:
82 switch (eth_hdr(skb)->h_proto) {
83 case htons(ETH_P_IP):
84 fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
85 break;
86 case htons(ETH_P_IPV6):
87 fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
88 break;
89 }
90 break;
91 case NFPROTO_IPV4:
92 fam = audit_ip4(ab, skb) ? NFPROTO_IPV4 : -1;
93 break;
94 case NFPROTO_IPV6:
95 fam = audit_ip6(ab, skb) ? NFPROTO_IPV6 : -1;
96 break;
97 }
98
99 if (fam == -1)
100 audit_log_format(ab, " saddr=? daddr=? proto=-1");
101
102 audit_log_end(ab);
103
104errout:
105 return XT_CONTINUE;
106}
107
108static unsigned int
109audit_tg_ebt(struct sk_buff *skb, const struct xt_action_param *par)
110{
111 audit_tg(skb, par);
112 return EBT_CONTINUE;
113}
114
115static int audit_tg_check(const struct xt_tgchk_param *par)
116{
117 const struct xt_audit_info *info = par->targinfo;
118
119 if (info->type > XT_AUDIT_TYPE_MAX) {
120 pr_info_ratelimited("Audit type out of range (valid range: 0..%u)\n",
121 XT_AUDIT_TYPE_MAX);
122 return -ERANGE;
123 }
124
125 return 0;
126}
127
128static struct xt_target audit_tg_reg[] __read_mostly = {
129 {
130 .name = "AUDIT",
131 .family = NFPROTO_UNSPEC,
132 .target = audit_tg,
133 .targetsize = sizeof(struct xt_audit_info),
134 .checkentry = audit_tg_check,
135 .me = THIS_MODULE,
136 },
137 {
138 .name = "AUDIT",
139 .family = NFPROTO_BRIDGE,
140 .target = audit_tg_ebt,
141 .targetsize = sizeof(struct xt_audit_info),
142 .checkentry = audit_tg_check,
143 .me = THIS_MODULE,
144 },
145};
146
147static int __init audit_tg_init(void)
148{
149 return xt_register_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
150}
151
152static void __exit audit_tg_exit(void)
153{
154 xt_unregister_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
155}
156
157module_init(audit_tg_init);
158module_exit(audit_tg_exit);
1/*
2 * Creates audit record for dropped/accepted packets
3 *
4 * (C) 2010-2011 Thomas Graf <tgraf@redhat.com>
5 * (C) 2010-2011 Red Hat, Inc.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10*/
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/audit.h>
15#include <linux/module.h>
16#include <linux/skbuff.h>
17#include <linux/tcp.h>
18#include <linux/udp.h>
19#include <linux/if_arp.h>
20#include <linux/netfilter/x_tables.h>
21#include <linux/netfilter/xt_AUDIT.h>
22#include <linux/netfilter_bridge/ebtables.h>
23#include <net/ipv6.h>
24#include <net/ip.h>
25
26MODULE_LICENSE("GPL");
27MODULE_AUTHOR("Thomas Graf <tgraf@redhat.com>");
28MODULE_DESCRIPTION("Xtables: creates audit records for dropped/accepted packets");
29MODULE_ALIAS("ipt_AUDIT");
30MODULE_ALIAS("ip6t_AUDIT");
31MODULE_ALIAS("ebt_AUDIT");
32MODULE_ALIAS("arpt_AUDIT");
33
34static void audit_proto(struct audit_buffer *ab, struct sk_buff *skb,
35 unsigned int proto, unsigned int offset)
36{
37 switch (proto) {
38 case IPPROTO_TCP:
39 case IPPROTO_UDP:
40 case IPPROTO_UDPLITE: {
41 const __be16 *pptr;
42 __be16 _ports[2];
43
44 pptr = skb_header_pointer(skb, offset, sizeof(_ports), _ports);
45 if (pptr == NULL) {
46 audit_log_format(ab, " truncated=1");
47 return;
48 }
49
50 audit_log_format(ab, " sport=%hu dport=%hu",
51 ntohs(pptr[0]), ntohs(pptr[1]));
52 }
53 break;
54
55 case IPPROTO_ICMP:
56 case IPPROTO_ICMPV6: {
57 const u8 *iptr;
58 u8 _ih[2];
59
60 iptr = skb_header_pointer(skb, offset, sizeof(_ih), &_ih);
61 if (iptr == NULL) {
62 audit_log_format(ab, " truncated=1");
63 return;
64 }
65
66 audit_log_format(ab, " icmptype=%hhu icmpcode=%hhu",
67 iptr[0], iptr[1]);
68
69 }
70 break;
71 }
72}
73
74static void audit_ip4(struct audit_buffer *ab, struct sk_buff *skb)
75{
76 struct iphdr _iph;
77 const struct iphdr *ih;
78
79 ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
80 if (!ih) {
81 audit_log_format(ab, " truncated=1");
82 return;
83 }
84
85 audit_log_format(ab, " saddr=%pI4 daddr=%pI4 ipid=%hu proto=%hhu",
86 &ih->saddr, &ih->daddr, ntohs(ih->id), ih->protocol);
87
88 if (ntohs(ih->frag_off) & IP_OFFSET) {
89 audit_log_format(ab, " frag=1");
90 return;
91 }
92
93 audit_proto(ab, skb, ih->protocol, ih->ihl * 4);
94}
95
96static void audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
97{
98 struct ipv6hdr _ip6h;
99 const struct ipv6hdr *ih;
100 u8 nexthdr;
101 int offset;
102
103 ih = skb_header_pointer(skb, skb_network_offset(skb), sizeof(_ip6h), &_ip6h);
104 if (!ih) {
105 audit_log_format(ab, " truncated=1");
106 return;
107 }
108
109 nexthdr = ih->nexthdr;
110 offset = ipv6_skip_exthdr(skb, skb_network_offset(skb) + sizeof(_ip6h),
111 &nexthdr);
112
113 audit_log_format(ab, " saddr=%pI6c daddr=%pI6c proto=%hhu",
114 &ih->saddr, &ih->daddr, nexthdr);
115
116 if (offset)
117 audit_proto(ab, skb, nexthdr, offset);
118}
119
120static unsigned int
121audit_tg(struct sk_buff *skb, const struct xt_action_param *par)
122{
123 const struct xt_audit_info *info = par->targinfo;
124 struct audit_buffer *ab;
125
126 ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
127 if (ab == NULL)
128 goto errout;
129
130 audit_log_format(ab, "action=%hhu hook=%u len=%u inif=%s outif=%s",
131 info->type, par->hooknum, skb->len,
132 par->in ? par->in->name : "?",
133 par->out ? par->out->name : "?");
134
135 if (skb->mark)
136 audit_log_format(ab, " mark=%#x", skb->mark);
137
138 if (skb->dev && skb->dev->type == ARPHRD_ETHER) {
139 audit_log_format(ab, " smac=%pM dmac=%pM macproto=0x%04x",
140 eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
141 ntohs(eth_hdr(skb)->h_proto));
142
143 if (par->family == NFPROTO_BRIDGE) {
144 switch (eth_hdr(skb)->h_proto) {
145 case __constant_htons(ETH_P_IP):
146 audit_ip4(ab, skb);
147 break;
148
149 case __constant_htons(ETH_P_IPV6):
150 audit_ip6(ab, skb);
151 break;
152 }
153 }
154 }
155
156 switch (par->family) {
157 case NFPROTO_IPV4:
158 audit_ip4(ab, skb);
159 break;
160
161 case NFPROTO_IPV6:
162 audit_ip6(ab, skb);
163 break;
164 }
165
166#ifdef CONFIG_NETWORK_SECMARK
167 if (skb->secmark)
168 audit_log_secctx(ab, skb->secmark);
169#endif
170
171 audit_log_end(ab);
172
173errout:
174 return XT_CONTINUE;
175}
176
177static unsigned int
178audit_tg_ebt(struct sk_buff *skb, const struct xt_action_param *par)
179{
180 audit_tg(skb, par);
181 return EBT_CONTINUE;
182}
183
184static int audit_tg_check(const struct xt_tgchk_param *par)
185{
186 const struct xt_audit_info *info = par->targinfo;
187
188 if (info->type > XT_AUDIT_TYPE_MAX) {
189 pr_info("Audit type out of range (valid range: 0..%hhu)\n",
190 XT_AUDIT_TYPE_MAX);
191 return -ERANGE;
192 }
193
194 return 0;
195}
196
197static struct xt_target audit_tg_reg[] __read_mostly = {
198 {
199 .name = "AUDIT",
200 .family = NFPROTO_UNSPEC,
201 .target = audit_tg,
202 .targetsize = sizeof(struct xt_audit_info),
203 .checkentry = audit_tg_check,
204 .me = THIS_MODULE,
205 },
206 {
207 .name = "AUDIT",
208 .family = NFPROTO_BRIDGE,
209 .target = audit_tg_ebt,
210 .targetsize = sizeof(struct xt_audit_info),
211 .checkentry = audit_tg_check,
212 .me = THIS_MODULE,
213 },
214};
215
216static int __init audit_tg_init(void)
217{
218 return xt_register_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
219}
220
221static void __exit audit_tg_exit(void)
222{
223 xt_unregister_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
224}
225
226module_init(audit_tg_init);
227module_exit(audit_tg_exit);