mqprio: Avoid panic if no options are provided
[linux-2.6.git] / net / netfilter / xt_AUDIT.c
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
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("Thomas Graf <tgraf@redhat.com>");
28 MODULE_DESCRIPTION("Xtables: creates audit records for dropped/accepted packets");
29 MODULE_ALIAS("ipt_AUDIT");
30 MODULE_ALIAS("ip6t_AUDIT");
31 MODULE_ALIAS("ebt_AUDIT");
32 MODULE_ALIAS("arpt_AUDIT");
33
34 static 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
74 static 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
96 static 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
120 static unsigned int
121 audit_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
173 errout:
174         return XT_CONTINUE;
175 }
176
177 static unsigned int
178 audit_tg_ebt(struct sk_buff *skb, const struct xt_action_param *par)
179 {
180         audit_tg(skb, par);
181         return EBT_CONTINUE;
182 }
183
184 static 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
197 static 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
216 static int __init audit_tg_init(void)
217 {
218         return xt_register_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
219 }
220
221 static void __exit audit_tg_exit(void)
222 {
223         xt_unregister_targets(audit_tg_reg, ARRAY_SIZE(audit_tg_reg));
224 }
225
226 module_init(audit_tg_init);
227 module_exit(audit_tg_exit);