a94f3cc377c0749cf54d479c9388abe3812b8d58
[linux-2.6.git] / net / bridge / netfilter / ebt_log.c
1 /*
2  *  ebt_log
3  *
4  *      Authors:
5  *      Bart De Schuymer <bdschuym@pandora.be>
6  *      Harald Welte <laforge@netfilter.org>
7  *
8  *  April, 2002
9  *
10  */
11 #include <linux/module.h>
12 #include <linux/ip.h>
13 #include <linux/in.h>
14 #include <linux/if_arp.h>
15 #include <linux/spinlock.h>
16 #include <net/netfilter/nf_log.h>
17 #include <linux/ipv6.h>
18 #include <net/ipv6.h>
19 #include <linux/in6.h>
20 #include <linux/netfilter/x_tables.h>
21 #include <linux/netfilter_bridge/ebtables.h>
22 #include <linux/netfilter_bridge/ebt_log.h>
23 #include <linux/netfilter.h>
24
25 static DEFINE_SPINLOCK(ebt_log_lock);
26
27 static bool ebt_log_tg_check(const struct xt_tgchk_param *par)
28 {
29         struct ebt_log_info *info = par->targinfo;
30
31         if (info->bitmask & ~EBT_LOG_MASK)
32                 return false;
33         if (info->loglevel >= 8)
34                 return false;
35         info->prefix[EBT_LOG_PREFIX_SIZE - 1] = '\0';
36         return true;
37 }
38
39 struct tcpudphdr
40 {
41         __be16 src;
42         __be16 dst;
43 };
44
45 struct arppayload
46 {
47         unsigned char mac_src[ETH_ALEN];
48         unsigned char ip_src[4];
49         unsigned char mac_dst[ETH_ALEN];
50         unsigned char ip_dst[4];
51 };
52
53 static void print_MAC(const unsigned char *p)
54 {
55         int i;
56
57         for (i = 0; i < ETH_ALEN; i++, p++)
58                 printk("%02x%c", *p, i == ETH_ALEN - 1 ? ' ':':');
59 }
60
61 static void
62 print_ports(const struct sk_buff *skb, uint8_t protocol, int offset)
63 {
64         if (protocol == IPPROTO_TCP ||
65             protocol == IPPROTO_UDP ||
66             protocol == IPPROTO_UDPLITE ||
67             protocol == IPPROTO_SCTP ||
68             protocol == IPPROTO_DCCP) {
69                 const struct tcpudphdr *pptr;
70                 struct tcpudphdr _ports;
71
72                 pptr = skb_header_pointer(skb, offset,
73                                           sizeof(_ports), &_ports);
74                 if (pptr == NULL) {
75                         printk(" INCOMPLETE TCP/UDP header");
76                         return;
77                 }
78                 printk(" SPT=%u DPT=%u", ntohs(pptr->src), ntohs(pptr->dst));
79         }
80 }
81
82 static void
83 ebt_log_packet(u_int8_t pf, unsigned int hooknum,
84    const struct sk_buff *skb, const struct net_device *in,
85    const struct net_device *out, const struct nf_loginfo *loginfo,
86    const char *prefix)
87 {
88         unsigned int bitmask;
89
90         spin_lock_bh(&ebt_log_lock);
91         printk("<%c>%s IN=%s OUT=%s MAC source = ", '0' + loginfo->u.log.level,
92                prefix, in ? in->name : "", out ? out->name : "");
93
94         print_MAC(eth_hdr(skb)->h_source);
95         printk("MAC dest = ");
96         print_MAC(eth_hdr(skb)->h_dest);
97
98         printk("proto = 0x%04x", ntohs(eth_hdr(skb)->h_proto));
99
100         if (loginfo->type == NF_LOG_TYPE_LOG)
101                 bitmask = loginfo->u.log.logflags;
102         else
103                 bitmask = NF_LOG_MASK;
104
105         if ((bitmask & EBT_LOG_IP) && eth_hdr(skb)->h_proto ==
106            htons(ETH_P_IP)){
107                 const struct iphdr *ih;
108                 struct iphdr _iph;
109
110                 ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
111                 if (ih == NULL) {
112                         printk(" INCOMPLETE IP header");
113                         goto out;
114                 }
115                 printk(" IP SRC=%pI4 IP DST=%pI4, IP tos=0x%02X, IP proto=%d",
116                        &ih->saddr, &ih->daddr, ih->tos, ih->protocol);
117                 print_ports(skb, ih->protocol, ih->ihl*4);
118                 goto out;
119         }
120
121 #if defined(CONFIG_BRIDGE_EBT_IP6) || defined(CONFIG_BRIDGE_EBT_IP6_MODULE)
122         if ((bitmask & EBT_LOG_IP6) && eth_hdr(skb)->h_proto ==
123            htons(ETH_P_IPV6)) {
124                 const struct ipv6hdr *ih;
125                 struct ipv6hdr _iph;
126                 uint8_t nexthdr;
127                 int offset_ph;
128
129                 ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
130                 if (ih == NULL) {
131                         printk(" INCOMPLETE IPv6 header");
132                         goto out;
133                 }
134                 printk(" IPv6 SRC=%pI6 IPv6 DST=%pI6, IPv6 priority=0x%01X, Next Header=%d",
135                        &ih->saddr, &ih->daddr, ih->priority, ih->nexthdr);
136                 nexthdr = ih->nexthdr;
137                 offset_ph = ipv6_skip_exthdr(skb, sizeof(_iph), &nexthdr);
138                 if (offset_ph == -1)
139                         goto out;
140                 print_ports(skb, nexthdr, offset_ph);
141                 goto out;
142         }
143 #endif
144
145         if ((bitmask & EBT_LOG_ARP) &&
146             ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) ||
147              (eth_hdr(skb)->h_proto == htons(ETH_P_RARP)))) {
148                 const struct arphdr *ah;
149                 struct arphdr _arph;
150
151                 ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph);
152                 if (ah == NULL) {
153                         printk(" INCOMPLETE ARP header");
154                         goto out;
155                 }
156                 printk(" ARP HTYPE=%d, PTYPE=0x%04x, OPCODE=%d",
157                        ntohs(ah->ar_hrd), ntohs(ah->ar_pro),
158                        ntohs(ah->ar_op));
159
160                 /* If it's for Ethernet and the lengths are OK,
161                  * then log the ARP payload */
162                 if (ah->ar_hrd == htons(1) &&
163                     ah->ar_hln == ETH_ALEN &&
164                     ah->ar_pln == sizeof(__be32)) {
165                         const struct arppayload *ap;
166                         struct arppayload _arpp;
167
168                         ap = skb_header_pointer(skb, sizeof(_arph),
169                                                 sizeof(_arpp), &_arpp);
170                         if (ap == NULL) {
171                                 printk(" INCOMPLETE ARP payload");
172                                 goto out;
173                         }
174                         printk(" ARP MAC SRC=");
175                         print_MAC(ap->mac_src);
176                         printk(" ARP IP SRC=%pI4", ap->ip_src);
177                         printk(" ARP MAC DST=");
178                         print_MAC(ap->mac_dst);
179                         printk(" ARP IP DST=%pI4", ap->ip_dst);
180                 }
181         }
182 out:
183         printk("\n");
184         spin_unlock_bh(&ebt_log_lock);
185
186 }
187
188 static unsigned int
189 ebt_log_tg(struct sk_buff *skb, const struct xt_target_param *par)
190 {
191         const struct ebt_log_info *info = par->targinfo;
192         struct nf_loginfo li;
193
194         li.type = NF_LOG_TYPE_LOG;
195         li.u.log.level = info->loglevel;
196         li.u.log.logflags = info->bitmask;
197
198         if (info->bitmask & EBT_LOG_NFLOG)
199                 nf_log_packet(NFPROTO_BRIDGE, par->hooknum, skb, par->in,
200                               par->out, &li, "%s", info->prefix);
201         else
202                 ebt_log_packet(NFPROTO_BRIDGE, par->hooknum, skb, par->in,
203                                par->out, &li, info->prefix);
204         return EBT_CONTINUE;
205 }
206
207 static struct xt_target ebt_log_tg_reg __read_mostly = {
208         .name           = "log",
209         .revision       = 0,
210         .family         = NFPROTO_BRIDGE,
211         .target         = ebt_log_tg,
212         .checkentry     = ebt_log_tg_check,
213         .targetsize     = XT_ALIGN(sizeof(struct ebt_log_info)),
214         .me             = THIS_MODULE,
215 };
216
217 static struct nf_logger ebt_log_logger __read_mostly = {
218         .name           = "ebt_log",
219         .logfn          = &ebt_log_packet,
220         .me             = THIS_MODULE,
221 };
222
223 static int __init ebt_log_init(void)
224 {
225         int ret;
226
227         ret = xt_register_target(&ebt_log_tg_reg);
228         if (ret < 0)
229                 return ret;
230         nf_log_register(NFPROTO_BRIDGE, &ebt_log_logger);
231         return 0;
232 }
233
234 static void __exit ebt_log_fini(void)
235 {
236         nf_log_unregister(&ebt_log_logger);
237         xt_unregister_target(&ebt_log_tg_reg);
238 }
239
240 module_init(ebt_log_init);
241 module_exit(ebt_log_fini);
242 MODULE_DESCRIPTION("Ebtables: Packet logging to syslog");
243 MODULE_LICENSE("GPL");