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6e837fb1 EB |
1 | /* |
2 | * common LSM auditing functions | |
3 | * | |
4 | * Based on code written for SELinux by : | |
5 | * Stephen Smalley, <sds@epoch.ncsc.mil> | |
6 | * James Morris <jmorris@redhat.com> | |
7 | * Author : Etienne Basset, <etienne.basset@ensta.org> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2, | |
11 | * as published by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #include <linux/types.h> | |
15 | #include <linux/stddef.h> | |
16 | #include <linux/kernel.h> | |
5a0e3ad6 | 17 | #include <linux/gfp.h> |
6e837fb1 EB |
18 | #include <linux/fs.h> |
19 | #include <linux/init.h> | |
20 | #include <net/sock.h> | |
21 | #include <linux/un.h> | |
22 | #include <net/af_unix.h> | |
23 | #include <linux/audit.h> | |
24 | #include <linux/ipv6.h> | |
25 | #include <linux/ip.h> | |
26 | #include <net/ip.h> | |
27 | #include <net/ipv6.h> | |
28 | #include <linux/tcp.h> | |
29 | #include <linux/udp.h> | |
30 | #include <linux/dccp.h> | |
31 | #include <linux/sctp.h> | |
32 | #include <linux/lsm_audit.h> | |
33 | ||
34 | /** | |
35 | * ipv4_skb_to_auditdata : fill auditdata from skb | |
36 | * @skb : the skb | |
37 | * @ad : the audit data to fill | |
38 | * @proto : the layer 4 protocol | |
39 | * | |
40 | * return 0 on success | |
41 | */ | |
42 | int ipv4_skb_to_auditdata(struct sk_buff *skb, | |
43 | struct common_audit_data *ad, u8 *proto) | |
44 | { | |
45 | int ret = 0; | |
46 | struct iphdr *ih; | |
47 | ||
48 | ih = ip_hdr(skb); | |
49 | if (ih == NULL) | |
50 | return -EINVAL; | |
51 | ||
52 | ad->u.net.v4info.saddr = ih->saddr; | |
53 | ad->u.net.v4info.daddr = ih->daddr; | |
54 | ||
55 | if (proto) | |
56 | *proto = ih->protocol; | |
57 | /* non initial fragment */ | |
58 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
59 | return 0; | |
60 | ||
61 | switch (ih->protocol) { | |
62 | case IPPROTO_TCP: { | |
63 | struct tcphdr *th = tcp_hdr(skb); | |
64 | if (th == NULL) | |
65 | break; | |
66 | ||
67 | ad->u.net.sport = th->source; | |
68 | ad->u.net.dport = th->dest; | |
69 | break; | |
70 | } | |
71 | case IPPROTO_UDP: { | |
72 | struct udphdr *uh = udp_hdr(skb); | |
73 | if (uh == NULL) | |
74 | break; | |
75 | ||
76 | ad->u.net.sport = uh->source; | |
77 | ad->u.net.dport = uh->dest; | |
78 | break; | |
79 | } | |
80 | case IPPROTO_DCCP: { | |
81 | struct dccp_hdr *dh = dccp_hdr(skb); | |
82 | if (dh == NULL) | |
83 | break; | |
84 | ||
85 | ad->u.net.sport = dh->dccph_sport; | |
86 | ad->u.net.dport = dh->dccph_dport; | |
87 | break; | |
88 | } | |
89 | case IPPROTO_SCTP: { | |
90 | struct sctphdr *sh = sctp_hdr(skb); | |
91 | if (sh == NULL) | |
92 | break; | |
93 | ad->u.net.sport = sh->source; | |
94 | ad->u.net.dport = sh->dest; | |
95 | break; | |
96 | } | |
97 | default: | |
98 | ret = -EINVAL; | |
99 | } | |
100 | return ret; | |
101 | } | |
102 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
103 | /** | |
104 | * ipv6_skb_to_auditdata : fill auditdata from skb | |
105 | * @skb : the skb | |
106 | * @ad : the audit data to fill | |
107 | * @proto : the layer 4 protocol | |
108 | * | |
109 | * return 0 on success | |
110 | */ | |
111 | int ipv6_skb_to_auditdata(struct sk_buff *skb, | |
112 | struct common_audit_data *ad, u8 *proto) | |
113 | { | |
114 | int offset, ret = 0; | |
115 | struct ipv6hdr *ip6; | |
116 | u8 nexthdr; | |
117 | ||
118 | ip6 = ipv6_hdr(skb); | |
119 | if (ip6 == NULL) | |
120 | return -EINVAL; | |
121 | ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr); | |
122 | ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr); | |
123 | ret = 0; | |
124 | /* IPv6 can have several extension header before the Transport header | |
125 | * skip them */ | |
126 | offset = skb_network_offset(skb); | |
127 | offset += sizeof(*ip6); | |
128 | nexthdr = ip6->nexthdr; | |
129 | offset = ipv6_skip_exthdr(skb, offset, &nexthdr); | |
130 | if (offset < 0) | |
131 | return 0; | |
132 | if (proto) | |
133 | *proto = nexthdr; | |
134 | switch (nexthdr) { | |
135 | case IPPROTO_TCP: { | |
136 | struct tcphdr _tcph, *th; | |
137 | ||
138 | th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); | |
139 | if (th == NULL) | |
140 | break; | |
141 | ||
142 | ad->u.net.sport = th->source; | |
143 | ad->u.net.dport = th->dest; | |
144 | break; | |
145 | } | |
146 | case IPPROTO_UDP: { | |
147 | struct udphdr _udph, *uh; | |
148 | ||
149 | uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); | |
150 | if (uh == NULL) | |
151 | break; | |
152 | ||
153 | ad->u.net.sport = uh->source; | |
154 | ad->u.net.dport = uh->dest; | |
155 | break; | |
156 | } | |
157 | case IPPROTO_DCCP: { | |
158 | struct dccp_hdr _dccph, *dh; | |
159 | ||
160 | dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); | |
161 | if (dh == NULL) | |
162 | break; | |
163 | ||
164 | ad->u.net.sport = dh->dccph_sport; | |
165 | ad->u.net.dport = dh->dccph_dport; | |
166 | break; | |
167 | } | |
168 | case IPPROTO_SCTP: { | |
169 | struct sctphdr _sctph, *sh; | |
170 | ||
171 | sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); | |
172 | if (sh == NULL) | |
173 | break; | |
174 | ad->u.net.sport = sh->source; | |
175 | ad->u.net.dport = sh->dest; | |
176 | break; | |
177 | } | |
178 | default: | |
179 | ret = -EINVAL; | |
180 | } | |
181 | return ret; | |
182 | } | |
183 | #endif | |
184 | ||
185 | ||
186 | static inline void print_ipv6_addr(struct audit_buffer *ab, | |
187 | struct in6_addr *addr, __be16 port, | |
188 | char *name1, char *name2) | |
189 | { | |
190 | if (!ipv6_addr_any(addr)) | |
d8116591 | 191 | audit_log_format(ab, " %s=%pI6c", name1, addr); |
6e837fb1 EB |
192 | if (port) |
193 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
194 | } | |
195 | ||
196 | static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr, | |
197 | __be16 port, char *name1, char *name2) | |
198 | { | |
199 | if (addr) | |
200 | audit_log_format(ab, " %s=%pI4", name1, &addr); | |
201 | if (port) | |
202 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
203 | } | |
204 | ||
205 | /** | |
206 | * dump_common_audit_data - helper to dump common audit data | |
207 | * @a : common audit data | |
208 | * | |
209 | */ | |
210 | static void dump_common_audit_data(struct audit_buffer *ab, | |
211 | struct common_audit_data *a) | |
212 | { | |
6e837fb1 EB |
213 | struct task_struct *tsk = current; |
214 | ||
215 | if (a->tsk) | |
216 | tsk = a->tsk; | |
217 | if (tsk && tsk->pid) { | |
218 | audit_log_format(ab, " pid=%d comm=", tsk->pid); | |
219 | audit_log_untrustedstring(ab, tsk->comm); | |
220 | } | |
221 | ||
222 | switch (a->type) { | |
cb84aa9b | 223 | case LSM_AUDIT_DATA_NONE: |
2bf49690 | 224 | return; |
6e837fb1 EB |
225 | case LSM_AUDIT_DATA_IPC: |
226 | audit_log_format(ab, " key=%d ", a->u.ipc_id); | |
227 | break; | |
228 | case LSM_AUDIT_DATA_CAP: | |
229 | audit_log_format(ab, " capability=%d ", a->u.cap); | |
230 | break; | |
f48b7399 | 231 | case LSM_AUDIT_DATA_PATH: { |
f48b7399 EP |
232 | struct inode *inode; |
233 | ||
a269434d EP |
234 | audit_log_d_path(ab, "path=", &a->u.path); |
235 | ||
236 | inode = a->u.path.dentry->d_inode; | |
237 | if (inode) | |
238 | audit_log_format(ab, " dev=%s ino=%lu", | |
239 | inode->i_sb->s_id, | |
240 | inode->i_ino); | |
241 | break; | |
242 | } | |
243 | case LSM_AUDIT_DATA_DENTRY: { | |
244 | struct inode *inode; | |
245 | ||
246 | audit_log_format(ab, " name="); | |
247 | audit_log_untrustedstring(ab, a->u.dentry->d_name.name); | |
248 | ||
249 | inode = a->u.dentry->d_inode; | |
6e837fb1 EB |
250 | if (inode) |
251 | audit_log_format(ab, " dev=%s ino=%lu", | |
252 | inode->i_sb->s_id, | |
253 | inode->i_ino); | |
254 | break; | |
f48b7399 EP |
255 | } |
256 | case LSM_AUDIT_DATA_INODE: { | |
257 | struct dentry *dentry; | |
258 | struct inode *inode; | |
259 | ||
260 | inode = a->u.inode; | |
261 | dentry = d_find_alias(inode); | |
262 | if (dentry) { | |
263 | audit_log_format(ab, " name="); | |
264 | audit_log_untrustedstring(ab, | |
265 | dentry->d_name.name); | |
266 | dput(dentry); | |
267 | } | |
268 | audit_log_format(ab, " dev=%s ino=%lu", inode->i_sb->s_id, | |
269 | inode->i_ino); | |
270 | break; | |
271 | } | |
6e837fb1 EB |
272 | case LSM_AUDIT_DATA_TASK: |
273 | tsk = a->u.tsk; | |
274 | if (tsk && tsk->pid) { | |
275 | audit_log_format(ab, " pid=%d comm=", tsk->pid); | |
276 | audit_log_untrustedstring(ab, tsk->comm); | |
277 | } | |
278 | break; | |
279 | case LSM_AUDIT_DATA_NET: | |
280 | if (a->u.net.sk) { | |
281 | struct sock *sk = a->u.net.sk; | |
282 | struct unix_sock *u; | |
283 | int len = 0; | |
284 | char *p = NULL; | |
285 | ||
286 | switch (sk->sk_family) { | |
287 | case AF_INET: { | |
288 | struct inet_sock *inet = inet_sk(sk); | |
289 | ||
c720c7e8 ED |
290 | print_ipv4_addr(ab, inet->inet_rcv_saddr, |
291 | inet->inet_sport, | |
6e837fb1 | 292 | "laddr", "lport"); |
c720c7e8 ED |
293 | print_ipv4_addr(ab, inet->inet_daddr, |
294 | inet->inet_dport, | |
6e837fb1 EB |
295 | "faddr", "fport"); |
296 | break; | |
297 | } | |
298 | case AF_INET6: { | |
299 | struct inet_sock *inet = inet_sk(sk); | |
300 | struct ipv6_pinfo *inet6 = inet6_sk(sk); | |
301 | ||
302 | print_ipv6_addr(ab, &inet6->rcv_saddr, | |
c720c7e8 | 303 | inet->inet_sport, |
6e837fb1 EB |
304 | "laddr", "lport"); |
305 | print_ipv6_addr(ab, &inet6->daddr, | |
c720c7e8 | 306 | inet->inet_dport, |
6e837fb1 EB |
307 | "faddr", "fport"); |
308 | break; | |
309 | } | |
310 | case AF_UNIX: | |
311 | u = unix_sk(sk); | |
312 | if (u->dentry) { | |
313 | struct path path = { | |
314 | .dentry = u->dentry, | |
315 | .mnt = u->mnt | |
316 | }; | |
317 | audit_log_d_path(ab, "path=", &path); | |
318 | break; | |
319 | } | |
320 | if (!u->addr) | |
321 | break; | |
322 | len = u->addr->len-sizeof(short); | |
323 | p = &u->addr->name->sun_path[0]; | |
324 | audit_log_format(ab, " path="); | |
325 | if (*p) | |
326 | audit_log_untrustedstring(ab, p); | |
327 | else | |
328 | audit_log_n_hex(ab, p, len); | |
329 | break; | |
330 | } | |
331 | } | |
332 | ||
333 | switch (a->u.net.family) { | |
334 | case AF_INET: | |
335 | print_ipv4_addr(ab, a->u.net.v4info.saddr, | |
336 | a->u.net.sport, | |
337 | "saddr", "src"); | |
338 | print_ipv4_addr(ab, a->u.net.v4info.daddr, | |
339 | a->u.net.dport, | |
340 | "daddr", "dest"); | |
341 | break; | |
342 | case AF_INET6: | |
343 | print_ipv6_addr(ab, &a->u.net.v6info.saddr, | |
344 | a->u.net.sport, | |
345 | "saddr", "src"); | |
346 | print_ipv6_addr(ab, &a->u.net.v6info.daddr, | |
347 | a->u.net.dport, | |
348 | "daddr", "dest"); | |
349 | break; | |
350 | } | |
351 | if (a->u.net.netif > 0) { | |
352 | struct net_device *dev; | |
353 | ||
354 | /* NOTE: we always use init's namespace */ | |
355 | dev = dev_get_by_index(&init_net, a->u.net.netif); | |
356 | if (dev) { | |
357 | audit_log_format(ab, " netif=%s", dev->name); | |
358 | dev_put(dev); | |
359 | } | |
360 | } | |
361 | break; | |
362 | #ifdef CONFIG_KEYS | |
363 | case LSM_AUDIT_DATA_KEY: | |
364 | audit_log_format(ab, " key_serial=%u", a->u.key_struct.key); | |
365 | if (a->u.key_struct.key_desc) { | |
366 | audit_log_format(ab, " key_desc="); | |
367 | audit_log_untrustedstring(ab, a->u.key_struct.key_desc); | |
368 | } | |
369 | break; | |
370 | #endif | |
dd8dbf2e EP |
371 | case LSM_AUDIT_DATA_KMOD: |
372 | audit_log_format(ab, " kmod="); | |
373 | audit_log_untrustedstring(ab, a->u.kmod_name); | |
374 | break; | |
6e837fb1 EB |
375 | } /* switch (a->type) */ |
376 | } | |
377 | ||
378 | /** | |
379 | * common_lsm_audit - generic LSM auditing function | |
380 | * @a: auxiliary audit data | |
381 | * | |
382 | * setup the audit buffer for common security information | |
383 | * uses callback to print LSM specific information | |
384 | */ | |
385 | void common_lsm_audit(struct common_audit_data *a) | |
386 | { | |
387 | struct audit_buffer *ab; | |
388 | ||
389 | if (a == NULL) | |
390 | return; | |
391 | /* we use GFP_ATOMIC so we won't sleep */ | |
392 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); | |
393 | ||
394 | if (ab == NULL) | |
395 | return; | |
396 | ||
397 | if (a->lsm_pre_audit) | |
398 | a->lsm_pre_audit(ab, a); | |
399 | ||
400 | dump_common_audit_data(ab, a); | |
401 | ||
402 | if (a->lsm_post_audit) | |
403 | a->lsm_post_audit(ab, a); | |
404 | ||
405 | audit_log_end(ab); | |
406 | } |