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8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/module.h>
11#include <linux/spinlock.h>
12#include <linux/skbuff.h>
13#include <linux/if_arp.h>
14#include <linux/ip.h>
15#include <net/ipv6.h>
16#include <net/icmp.h>
17#include <net/udp.h>
18#include <net/tcp.h>
19#include <net/route.h>
20
21#include <linux/netfilter.h>
22#include <linux/netfilter/xt_LOG.h>
23#include <net/netfilter/nf_log.h>
24
25static struct nf_loginfo default_loginfo = {
26 .type = NF_LOG_TYPE_LOG,
27 .u = {
28 .log = {
29 .level = 5,
30 .logflags = NF_LOG_MASK,
31 },
32 },
33};
34
35
36static void dump_ipv4_packet(struct nf_log_buf *m,
37 const struct nf_loginfo *info,
38 const struct sk_buff *skb, unsigned int iphoff)
39{
40 struct iphdr _iph;
41 const struct iphdr *ih;
42 unsigned int logflags;
43
44 if (info->type == NF_LOG_TYPE_LOG)
45 logflags = info->u.log.logflags;
46 else
47 logflags = NF_LOG_MASK;
48
49 ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
50 if (ih == NULL) {
51 nf_log_buf_add(m, "TRUNCATED");
52 return;
53 }
54
55
56
57
58 nf_log_buf_add(m, "SRC=%pI4 DST=%pI4 ", &ih->saddr, &ih->daddr);
59
60
61 nf_log_buf_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
62 ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
63 ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));
64
65
66 if (ntohs(ih->frag_off) & IP_CE)
67 nf_log_buf_add(m, "CE ");
68 if (ntohs(ih->frag_off) & IP_DF)
69 nf_log_buf_add(m, "DF ");
70 if (ntohs(ih->frag_off) & IP_MF)
71 nf_log_buf_add(m, "MF ");
72
73
74 if (ntohs(ih->frag_off) & IP_OFFSET)
75 nf_log_buf_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
76
77 if ((logflags & XT_LOG_IPOPT) &&
78 ih->ihl * 4 > sizeof(struct iphdr)) {
79 const unsigned char *op;
80 unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
81 unsigned int i, optsize;
82
83 optsize = ih->ihl * 4 - sizeof(struct iphdr);
84 op = skb_header_pointer(skb, iphoff+sizeof(_iph),
85 optsize, _opt);
86 if (op == NULL) {
87 nf_log_buf_add(m, "TRUNCATED");
88 return;
89 }
90
91
92 nf_log_buf_add(m, "OPT (");
93 for (i = 0; i < optsize; i++)
94 nf_log_buf_add(m, "%02X", op[i]);
95 nf_log_buf_add(m, ") ");
96 }
97
98 switch (ih->protocol) {
99 case IPPROTO_TCP:
100 if (nf_log_dump_tcp_header(m, skb, ih->protocol,
101 ntohs(ih->frag_off) & IP_OFFSET,
102 iphoff+ih->ihl*4, logflags))
103 return;
104 break;
105 case IPPROTO_UDP:
106 case IPPROTO_UDPLITE:
107 if (nf_log_dump_udp_header(m, skb, ih->protocol,
108 ntohs(ih->frag_off) & IP_OFFSET,
109 iphoff+ih->ihl*4))
110 return;
111 break;
112 case IPPROTO_ICMP: {
113 struct icmphdr _icmph;
114 const struct icmphdr *ich;
115 static const size_t required_len[NR_ICMP_TYPES+1]
116 = { [ICMP_ECHOREPLY] = 4,
117 [ICMP_DEST_UNREACH]
118 = 8 + sizeof(struct iphdr),
119 [ICMP_SOURCE_QUENCH]
120 = 8 + sizeof(struct iphdr),
121 [ICMP_REDIRECT]
122 = 8 + sizeof(struct iphdr),
123 [ICMP_ECHO] = 4,
124 [ICMP_TIME_EXCEEDED]
125 = 8 + sizeof(struct iphdr),
126 [ICMP_PARAMETERPROB]
127 = 8 + sizeof(struct iphdr),
128 [ICMP_TIMESTAMP] = 20,
129 [ICMP_TIMESTAMPREPLY] = 20,
130 [ICMP_ADDRESS] = 12,
131 [ICMP_ADDRESSREPLY] = 12 };
132
133
134 nf_log_buf_add(m, "PROTO=ICMP ");
135
136 if (ntohs(ih->frag_off) & IP_OFFSET)
137 break;
138
139
140 ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
141 sizeof(_icmph), &_icmph);
142 if (ich == NULL) {
143 nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
144 skb->len - iphoff - ih->ihl*4);
145 break;
146 }
147
148
149 nf_log_buf_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code);
150
151
152 if (ich->type <= NR_ICMP_TYPES &&
153 required_len[ich->type] &&
154 skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
155 nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
156 skb->len - iphoff - ih->ihl*4);
157 break;
158 }
159
160 switch (ich->type) {
161 case ICMP_ECHOREPLY:
162 case ICMP_ECHO:
163
164 nf_log_buf_add(m, "ID=%u SEQ=%u ",
165 ntohs(ich->un.echo.id),
166 ntohs(ich->un.echo.sequence));
167 break;
168
169 case ICMP_PARAMETERPROB:
170
171 nf_log_buf_add(m, "PARAMETER=%u ",
172 ntohl(ich->un.gateway) >> 24);
173 break;
174 case ICMP_REDIRECT:
175
176 nf_log_buf_add(m, "GATEWAY=%pI4 ", &ich->un.gateway);
177
178 case ICMP_DEST_UNREACH:
179 case ICMP_SOURCE_QUENCH:
180 case ICMP_TIME_EXCEEDED:
181
182 if (!iphoff) {
183 nf_log_buf_add(m, "[");
184 dump_ipv4_packet(m, info, skb,
185 iphoff + ih->ihl*4+sizeof(_icmph));
186 nf_log_buf_add(m, "] ");
187 }
188
189
190 if (ich->type == ICMP_DEST_UNREACH &&
191 ich->code == ICMP_FRAG_NEEDED) {
192 nf_log_buf_add(m, "MTU=%u ",
193 ntohs(ich->un.frag.mtu));
194 }
195 }
196 break;
197 }
198
199 case IPPROTO_AH: {
200 struct ip_auth_hdr _ahdr;
201 const struct ip_auth_hdr *ah;
202
203 if (ntohs(ih->frag_off) & IP_OFFSET)
204 break;
205
206
207 nf_log_buf_add(m, "PROTO=AH ");
208
209
210 ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
211 sizeof(_ahdr), &_ahdr);
212 if (ah == NULL) {
213 nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
214 skb->len - iphoff - ih->ihl*4);
215 break;
216 }
217
218
219 nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi));
220 break;
221 }
222 case IPPROTO_ESP: {
223 struct ip_esp_hdr _esph;
224 const struct ip_esp_hdr *eh;
225
226
227 nf_log_buf_add(m, "PROTO=ESP ");
228
229 if (ntohs(ih->frag_off) & IP_OFFSET)
230 break;
231
232
233 eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
234 sizeof(_esph), &_esph);
235 if (eh == NULL) {
236 nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
237 skb->len - iphoff - ih->ihl*4);
238 break;
239 }
240
241
242 nf_log_buf_add(m, "SPI=0x%x ", ntohl(eh->spi));
243 break;
244 }
245
246 default:
247 nf_log_buf_add(m, "PROTO=%u ", ih->protocol);
248 }
249
250
251 if ((logflags & XT_LOG_UID) && !iphoff)
252 nf_log_dump_sk_uid_gid(m, skb->sk);
253
254
255 if (!iphoff && skb->mark)
256 nf_log_buf_add(m, "MARK=0x%x ", skb->mark);
257
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267
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269
270
271}
272
273static void dump_ipv4_mac_header(struct nf_log_buf *m,
274 const struct nf_loginfo *info,
275 const struct sk_buff *skb)
276{
277 struct net_device *dev = skb->dev;
278 unsigned int logflags = 0;
279
280 if (info->type == NF_LOG_TYPE_LOG)
281 logflags = info->u.log.logflags;
282
283 if (!(logflags & XT_LOG_MACDECODE))
284 goto fallback;
285
286 switch (dev->type) {
287 case ARPHRD_ETHER:
288 nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ",
289 eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
290 ntohs(eth_hdr(skb)->h_proto));
291 return;
292 default:
293 break;
294 }
295
296fallback:
297 nf_log_buf_add(m, "MAC=");
298 if (dev->hard_header_len &&
299 skb->mac_header != skb->network_header) {
300 const unsigned char *p = skb_mac_header(skb);
301 unsigned int i;
302
303 nf_log_buf_add(m, "%02x", *p++);
304 for (i = 1; i < dev->hard_header_len; i++, p++)
305 nf_log_buf_add(m, ":%02x", *p);
306 }
307 nf_log_buf_add(m, " ");
308}
309
310static void nf_log_ip_packet(struct net *net, u_int8_t pf,
311 unsigned int hooknum, const struct sk_buff *skb,
312 const struct net_device *in,
313 const struct net_device *out,
314 const struct nf_loginfo *loginfo,
315 const char *prefix)
316{
317 struct nf_log_buf *m;
318
319
320 if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns)
321 return;
322
323 m = nf_log_buf_open();
324
325 if (!loginfo)
326 loginfo = &default_loginfo;
327
328 nf_log_dump_packet_common(m, pf, hooknum, skb, in,
329 out, loginfo, prefix);
330
331 if (in != NULL)
332 dump_ipv4_mac_header(m, loginfo, skb);
333
334 dump_ipv4_packet(m, loginfo, skb, 0);
335
336 nf_log_buf_close(m);
337}
338
339static struct nf_logger nf_ip_logger __read_mostly = {
340 .name = "nf_log_ipv4",
341 .type = NF_LOG_TYPE_LOG,
342 .logfn = nf_log_ip_packet,
343 .me = THIS_MODULE,
344};
345
346static int __net_init nf_log_ipv4_net_init(struct net *net)
347{
348 nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger);
349 return 0;
350}
351
352static void __net_exit nf_log_ipv4_net_exit(struct net *net)
353{
354 nf_log_unset(net, &nf_ip_logger);
355}
356
357static struct pernet_operations nf_log_ipv4_net_ops = {
358 .init = nf_log_ipv4_net_init,
359 .exit = nf_log_ipv4_net_exit,
360};
361
362static int __init nf_log_ipv4_init(void)
363{
364 int ret;
365
366 ret = register_pernet_subsys(&nf_log_ipv4_net_ops);
367 if (ret < 0)
368 return ret;
369
370 ret = nf_log_register(NFPROTO_IPV4, &nf_ip_logger);
371 if (ret < 0) {
372 pr_err("failed to register logger\n");
373 goto err1;
374 }
375
376 return 0;
377
378err1:
379 unregister_pernet_subsys(&nf_log_ipv4_net_ops);
380 return ret;
381}
382
383static void __exit nf_log_ipv4_exit(void)
384{
385 unregister_pernet_subsys(&nf_log_ipv4_net_ops);
386 nf_log_unregister(&nf_ip_logger);
387}
388
389module_init(nf_log_ipv4_init);
390module_exit(nf_log_ipv4_exit);
391
392MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
393MODULE_DESCRIPTION("Netfilter IPv4 packet logging");
394MODULE_LICENSE("GPL");
395MODULE_ALIAS_NF_LOGGER(AF_INET, 0);
396
