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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
83e96d44 PNA |
2 | /* (C) 1999-2001 Paul `Rusty' Russell |
3 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
83e96d44 | 4 | */ |
a81b2ce8 | 5 | |
8ac2bde2 | 6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
83e96d44 | 7 | |
a81b2ce8 | 8 | #include <linux/kernel.h> |
83e96d44 PNA |
9 | #include <linux/module.h> |
10 | #include <linux/spinlock.h> | |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/if_arp.h> | |
13 | #include <linux/ip.h> | |
14 | #include <net/ipv6.h> | |
15 | #include <net/icmp.h> | |
16 | #include <net/udp.h> | |
17 | #include <net/tcp.h> | |
18 | #include <net/route.h> | |
19 | ||
20 | #include <linux/netfilter.h> | |
21 | #include <linux/netfilter/xt_LOG.h> | |
22 | #include <net/netfilter/nf_log.h> | |
23 | ||
549d2d41 | 24 | static const struct nf_loginfo default_loginfo = { |
83e96d44 PNA |
25 | .type = NF_LOG_TYPE_LOG, |
26 | .u = { | |
27 | .log = { | |
a81b2ce8 | 28 | .level = LOGLEVEL_NOTICE, |
ff107d27 | 29 | .logflags = NF_LOG_DEFAULT_MASK, |
83e96d44 PNA |
30 | }, |
31 | }, | |
32 | }; | |
33 | ||
34 | /* One level of recursion won't kill us */ | |
f5646501 | 35 | static void dump_ipv4_packet(struct net *net, struct nf_log_buf *m, |
83e96d44 PNA |
36 | const struct nf_loginfo *info, |
37 | const struct sk_buff *skb, unsigned int iphoff) | |
38 | { | |
39 | struct iphdr _iph; | |
40 | const struct iphdr *ih; | |
41 | unsigned int logflags; | |
42 | ||
43 | if (info->type == NF_LOG_TYPE_LOG) | |
44 | logflags = info->u.log.logflags; | |
45 | else | |
ff107d27 | 46 | logflags = NF_LOG_DEFAULT_MASK; |
83e96d44 PNA |
47 | |
48 | ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph); | |
49 | if (ih == NULL) { | |
50 | nf_log_buf_add(m, "TRUNCATED"); | |
51 | return; | |
52 | } | |
53 | ||
54 | /* Important fields: | |
55 | * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */ | |
56 | /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */ | |
57 | nf_log_buf_add(m, "SRC=%pI4 DST=%pI4 ", &ih->saddr, &ih->daddr); | |
58 | ||
59 | /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ | |
60 | nf_log_buf_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ", | |
61 | ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK, | |
62 | ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id)); | |
63 | ||
64 | /* Max length: 6 "CE DF MF " */ | |
65 | if (ntohs(ih->frag_off) & IP_CE) | |
66 | nf_log_buf_add(m, "CE "); | |
67 | if (ntohs(ih->frag_off) & IP_DF) | |
68 | nf_log_buf_add(m, "DF "); | |
69 | if (ntohs(ih->frag_off) & IP_MF) | |
70 | nf_log_buf_add(m, "MF "); | |
71 | ||
72 | /* Max length: 11 "FRAG:65535 " */ | |
73 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
74 | nf_log_buf_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET); | |
75 | ||
8cb2a7d5 | 76 | if ((logflags & NF_LOG_IPOPT) && |
83e96d44 PNA |
77 | ih->ihl * 4 > sizeof(struct iphdr)) { |
78 | const unsigned char *op; | |
79 | unsigned char _opt[4 * 15 - sizeof(struct iphdr)]; | |
80 | unsigned int i, optsize; | |
81 | ||
82 | optsize = ih->ihl * 4 - sizeof(struct iphdr); | |
83 | op = skb_header_pointer(skb, iphoff+sizeof(_iph), | |
84 | optsize, _opt); | |
85 | if (op == NULL) { | |
86 | nf_log_buf_add(m, "TRUNCATED"); | |
87 | return; | |
88 | } | |
89 | ||
90 | /* Max length: 127 "OPT (" 15*4*2chars ") " */ | |
91 | nf_log_buf_add(m, "OPT ("); | |
92 | for (i = 0; i < optsize; i++) | |
93 | nf_log_buf_add(m, "%02X", op[i]); | |
94 | nf_log_buf_add(m, ") "); | |
95 | } | |
96 | ||
97 | switch (ih->protocol) { | |
98 | case IPPROTO_TCP: | |
99 | if (nf_log_dump_tcp_header(m, skb, ih->protocol, | |
100 | ntohs(ih->frag_off) & IP_OFFSET, | |
101 | iphoff+ih->ihl*4, logflags)) | |
102 | return; | |
103 | break; | |
104 | case IPPROTO_UDP: | |
105 | case IPPROTO_UDPLITE: | |
106 | if (nf_log_dump_udp_header(m, skb, ih->protocol, | |
107 | ntohs(ih->frag_off) & IP_OFFSET, | |
108 | iphoff+ih->ihl*4)) | |
109 | return; | |
110 | break; | |
111 | case IPPROTO_ICMP: { | |
112 | struct icmphdr _icmph; | |
113 | const struct icmphdr *ich; | |
114 | static const size_t required_len[NR_ICMP_TYPES+1] | |
115 | = { [ICMP_ECHOREPLY] = 4, | |
116 | [ICMP_DEST_UNREACH] | |
117 | = 8 + sizeof(struct iphdr), | |
118 | [ICMP_SOURCE_QUENCH] | |
119 | = 8 + sizeof(struct iphdr), | |
120 | [ICMP_REDIRECT] | |
121 | = 8 + sizeof(struct iphdr), | |
122 | [ICMP_ECHO] = 4, | |
123 | [ICMP_TIME_EXCEEDED] | |
124 | = 8 + sizeof(struct iphdr), | |
125 | [ICMP_PARAMETERPROB] | |
126 | = 8 + sizeof(struct iphdr), | |
127 | [ICMP_TIMESTAMP] = 20, | |
128 | [ICMP_TIMESTAMPREPLY] = 20, | |
129 | [ICMP_ADDRESS] = 12, | |
130 | [ICMP_ADDRESSREPLY] = 12 }; | |
131 | ||
132 | /* Max length: 11 "PROTO=ICMP " */ | |
133 | nf_log_buf_add(m, "PROTO=ICMP "); | |
134 | ||
135 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
136 | break; | |
137 | ||
138 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
139 | ich = skb_header_pointer(skb, iphoff + ih->ihl * 4, | |
140 | sizeof(_icmph), &_icmph); | |
141 | if (ich == NULL) { | |
142 | nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", | |
143 | skb->len - iphoff - ih->ihl*4); | |
144 | break; | |
145 | } | |
146 | ||
147 | /* Max length: 18 "TYPE=255 CODE=255 " */ | |
148 | nf_log_buf_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code); | |
149 | ||
150 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
151 | if (ich->type <= NR_ICMP_TYPES && | |
152 | required_len[ich->type] && | |
153 | skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) { | |
154 | nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", | |
155 | skb->len - iphoff - ih->ihl*4); | |
156 | break; | |
157 | } | |
158 | ||
159 | switch (ich->type) { | |
160 | case ICMP_ECHOREPLY: | |
161 | case ICMP_ECHO: | |
162 | /* Max length: 19 "ID=65535 SEQ=65535 " */ | |
163 | nf_log_buf_add(m, "ID=%u SEQ=%u ", | |
164 | ntohs(ich->un.echo.id), | |
165 | ntohs(ich->un.echo.sequence)); | |
166 | break; | |
167 | ||
168 | case ICMP_PARAMETERPROB: | |
169 | /* Max length: 14 "PARAMETER=255 " */ | |
170 | nf_log_buf_add(m, "PARAMETER=%u ", | |
171 | ntohl(ich->un.gateway) >> 24); | |
172 | break; | |
173 | case ICMP_REDIRECT: | |
174 | /* Max length: 24 "GATEWAY=255.255.255.255 " */ | |
175 | nf_log_buf_add(m, "GATEWAY=%pI4 ", &ich->un.gateway); | |
176 | /* Fall through */ | |
177 | case ICMP_DEST_UNREACH: | |
178 | case ICMP_SOURCE_QUENCH: | |
179 | case ICMP_TIME_EXCEEDED: | |
180 | /* Max length: 3+maxlen */ | |
181 | if (!iphoff) { /* Only recurse once. */ | |
182 | nf_log_buf_add(m, "["); | |
f5646501 | 183 | dump_ipv4_packet(net, m, info, skb, |
83e96d44 PNA |
184 | iphoff + ih->ihl*4+sizeof(_icmph)); |
185 | nf_log_buf_add(m, "] "); | |
186 | } | |
187 | ||
188 | /* Max length: 10 "MTU=65535 " */ | |
189 | if (ich->type == ICMP_DEST_UNREACH && | |
190 | ich->code == ICMP_FRAG_NEEDED) { | |
191 | nf_log_buf_add(m, "MTU=%u ", | |
192 | ntohs(ich->un.frag.mtu)); | |
193 | } | |
194 | } | |
195 | break; | |
196 | } | |
197 | /* Max Length */ | |
198 | case IPPROTO_AH: { | |
199 | struct ip_auth_hdr _ahdr; | |
200 | const struct ip_auth_hdr *ah; | |
201 | ||
202 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
203 | break; | |
204 | ||
205 | /* Max length: 9 "PROTO=AH " */ | |
206 | nf_log_buf_add(m, "PROTO=AH "); | |
207 | ||
208 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
209 | ah = skb_header_pointer(skb, iphoff+ih->ihl*4, | |
210 | sizeof(_ahdr), &_ahdr); | |
211 | if (ah == NULL) { | |
212 | nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", | |
213 | skb->len - iphoff - ih->ihl*4); | |
214 | break; | |
215 | } | |
216 | ||
217 | /* Length: 15 "SPI=0xF1234567 " */ | |
218 | nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi)); | |
219 | break; | |
220 | } | |
221 | case IPPROTO_ESP: { | |
222 | struct ip_esp_hdr _esph; | |
223 | const struct ip_esp_hdr *eh; | |
224 | ||
225 | /* Max length: 10 "PROTO=ESP " */ | |
226 | nf_log_buf_add(m, "PROTO=ESP "); | |
227 | ||
228 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
229 | break; | |
230 | ||
231 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
232 | eh = skb_header_pointer(skb, iphoff+ih->ihl*4, | |
233 | sizeof(_esph), &_esph); | |
234 | if (eh == NULL) { | |
235 | nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", | |
236 | skb->len - iphoff - ih->ihl*4); | |
237 | break; | |
238 | } | |
239 | ||
240 | /* Length: 15 "SPI=0xF1234567 " */ | |
241 | nf_log_buf_add(m, "SPI=0x%x ", ntohl(eh->spi)); | |
242 | break; | |
243 | } | |
244 | /* Max length: 10 "PROTO 255 " */ | |
245 | default: | |
246 | nf_log_buf_add(m, "PROTO=%u ", ih->protocol); | |
247 | } | |
248 | ||
249 | /* Max length: 15 "UID=4294967295 " */ | |
8cb2a7d5 | 250 | if ((logflags & NF_LOG_UID) && !iphoff) |
f5646501 | 251 | nf_log_dump_sk_uid_gid(net, m, skb->sk); |
83e96d44 PNA |
252 | |
253 | /* Max length: 16 "MARK=0xFFFFFFFF " */ | |
254 | if (!iphoff && skb->mark) | |
255 | nf_log_buf_add(m, "MARK=0x%x ", skb->mark); | |
256 | ||
257 | /* Proto Max log string length */ | |
258 | /* IP: 40+46+6+11+127 = 230 */ | |
259 | /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */ | |
260 | /* UDP: 10+max(25,20) = 35 */ | |
261 | /* UDPLITE: 14+max(25,20) = 39 */ | |
262 | /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */ | |
263 | /* ESP: 10+max(25)+15 = 50 */ | |
264 | /* AH: 9+max(25)+15 = 49 */ | |
265 | /* unknown: 10 */ | |
266 | ||
267 | /* (ICMP allows recursion one level deep) */ | |
268 | /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */ | |
269 | /* maxlen = 230+ 91 + 230 + 252 = 803 */ | |
270 | } | |
271 | ||
272 | static void dump_ipv4_mac_header(struct nf_log_buf *m, | |
273 | const struct nf_loginfo *info, | |
274 | const struct sk_buff *skb) | |
275 | { | |
276 | struct net_device *dev = skb->dev; | |
277 | unsigned int logflags = 0; | |
278 | ||
279 | if (info->type == NF_LOG_TYPE_LOG) | |
280 | logflags = info->u.log.logflags; | |
281 | ||
8cb2a7d5 | 282 | if (!(logflags & NF_LOG_MACDECODE)) |
83e96d44 PNA |
283 | goto fallback; |
284 | ||
285 | switch (dev->type) { | |
286 | case ARPHRD_ETHER: | |
287 | nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", | |
288 | eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, | |
289 | ntohs(eth_hdr(skb)->h_proto)); | |
290 | return; | |
291 | default: | |
292 | break; | |
293 | } | |
294 | ||
295 | fallback: | |
296 | nf_log_buf_add(m, "MAC="); | |
297 | if (dev->hard_header_len && | |
298 | skb->mac_header != skb->network_header) { | |
299 | const unsigned char *p = skb_mac_header(skb); | |
300 | unsigned int i; | |
301 | ||
302 | nf_log_buf_add(m, "%02x", *p++); | |
303 | for (i = 1; i < dev->hard_header_len; i++, p++) | |
304 | nf_log_buf_add(m, ":%02x", *p); | |
305 | } | |
306 | nf_log_buf_add(m, " "); | |
307 | } | |
308 | ||
fab4085f PNA |
309 | static void nf_log_ip_packet(struct net *net, u_int8_t pf, |
310 | unsigned int hooknum, const struct sk_buff *skb, | |
311 | const struct net_device *in, | |
312 | const struct net_device *out, | |
313 | const struct nf_loginfo *loginfo, | |
314 | const char *prefix) | |
83e96d44 PNA |
315 | { |
316 | struct nf_log_buf *m; | |
317 | ||
318 | /* FIXME: Disabled from containers until syslog ns is supported */ | |
2851940f | 319 | if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) |
83e96d44 PNA |
320 | return; |
321 | ||
322 | m = nf_log_buf_open(); | |
323 | ||
324 | if (!loginfo) | |
325 | loginfo = &default_loginfo; | |
326 | ||
327 | nf_log_dump_packet_common(m, pf, hooknum, skb, in, | |
328 | out, loginfo, prefix); | |
329 | ||
330 | if (in != NULL) | |
331 | dump_ipv4_mac_header(m, loginfo, skb); | |
332 | ||
f5646501 | 333 | dump_ipv4_packet(net, m, loginfo, skb, 0); |
83e96d44 PNA |
334 | |
335 | nf_log_buf_close(m); | |
336 | } | |
83e96d44 PNA |
337 | |
338 | static struct nf_logger nf_ip_logger __read_mostly = { | |
339 | .name = "nf_log_ipv4", | |
340 | .type = NF_LOG_TYPE_LOG, | |
341 | .logfn = nf_log_ip_packet, | |
342 | .me = THIS_MODULE, | |
343 | }; | |
344 | ||
345 | static int __net_init nf_log_ipv4_net_init(struct net *net) | |
346 | { | |
779994fa | 347 | return nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger); |
83e96d44 PNA |
348 | } |
349 | ||
350 | static void __net_exit nf_log_ipv4_net_exit(struct net *net) | |
351 | { | |
352 | nf_log_unset(net, &nf_ip_logger); | |
353 | } | |
354 | ||
355 | static struct pernet_operations nf_log_ipv4_net_ops = { | |
356 | .init = nf_log_ipv4_net_init, | |
357 | .exit = nf_log_ipv4_net_exit, | |
358 | }; | |
359 | ||
360 | static int __init nf_log_ipv4_init(void) | |
361 | { | |
362 | int ret; | |
363 | ||
364 | ret = register_pernet_subsys(&nf_log_ipv4_net_ops); | |
365 | if (ret < 0) | |
366 | return ret; | |
367 | ||
8ac2bde2 ML |
368 | ret = nf_log_register(NFPROTO_IPV4, &nf_ip_logger); |
369 | if (ret < 0) { | |
370 | pr_err("failed to register logger\n"); | |
371 | goto err1; | |
372 | } | |
373 | ||
83e96d44 | 374 | return 0; |
8ac2bde2 ML |
375 | |
376 | err1: | |
377 | unregister_pernet_subsys(&nf_log_ipv4_net_ops); | |
378 | return ret; | |
83e96d44 PNA |
379 | } |
380 | ||
381 | static void __exit nf_log_ipv4_exit(void) | |
382 | { | |
383 | unregister_pernet_subsys(&nf_log_ipv4_net_ops); | |
384 | nf_log_unregister(&nf_ip_logger); | |
385 | } | |
386 | ||
387 | module_init(nf_log_ipv4_init); | |
388 | module_exit(nf_log_ipv4_exit); | |
389 | ||
390 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); | |
391 | MODULE_DESCRIPTION("Netfilter IPv4 packet logging"); | |
392 | MODULE_LICENSE("GPL"); | |
fab4085f | 393 | MODULE_ALIAS_NF_LOGGER(AF_INET, 0); |