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6e837fb1 EB |
1 | /* |
2 | * common LSM auditing functions | |
3 | * | |
4 | * Based on code written for SELinux by : | |
5 | * Stephen Smalley, <[email protected]> | |
6 | * James Morris <[email protected]> | |
7 | * Author : Etienne Basset, <[email protected]> | |
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 | ||
48c62af6 EP |
52 | ad->u.net->v4info.saddr = ih->saddr; |
53 | ad->u.net->v4info.daddr = ih->daddr; | |
6e837fb1 EB |
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 | ||
48c62af6 EP |
67 | ad->u.net->sport = th->source; |
68 | ad->u.net->dport = th->dest; | |
6e837fb1 EB |
69 | break; |
70 | } | |
71 | case IPPROTO_UDP: { | |
72 | struct udphdr *uh = udp_hdr(skb); | |
73 | if (uh == NULL) | |
74 | break; | |
75 | ||
48c62af6 EP |
76 | ad->u.net->sport = uh->source; |
77 | ad->u.net->dport = uh->dest; | |
6e837fb1 EB |
78 | break; |
79 | } | |
80 | case IPPROTO_DCCP: { | |
81 | struct dccp_hdr *dh = dccp_hdr(skb); | |
82 | if (dh == NULL) | |
83 | break; | |
84 | ||
48c62af6 EP |
85 | ad->u.net->sport = dh->dccph_sport; |
86 | ad->u.net->dport = dh->dccph_dport; | |
6e837fb1 EB |
87 | break; |
88 | } | |
89 | case IPPROTO_SCTP: { | |
90 | struct sctphdr *sh = sctp_hdr(skb); | |
91 | if (sh == NULL) | |
92 | break; | |
48c62af6 EP |
93 | ad->u.net->sport = sh->source; |
94 | ad->u.net->dport = sh->dest; | |
6e837fb1 EB |
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; | |
75f2811c | 117 | __be16 frag_off; |
6e837fb1 EB |
118 | |
119 | ip6 = ipv6_hdr(skb); | |
120 | if (ip6 == NULL) | |
121 | return -EINVAL; | |
48c62af6 EP |
122 | ad->u.net->v6info.saddr = ip6->saddr; |
123 | ad->u.net->v6info.daddr = ip6->daddr; | |
6e837fb1 EB |
124 | ret = 0; |
125 | /* IPv6 can have several extension header before the Transport header | |
126 | * skip them */ | |
127 | offset = skb_network_offset(skb); | |
128 | offset += sizeof(*ip6); | |
129 | nexthdr = ip6->nexthdr; | |
75f2811c | 130 | offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); |
6e837fb1 EB |
131 | if (offset < 0) |
132 | return 0; | |
133 | if (proto) | |
134 | *proto = nexthdr; | |
135 | switch (nexthdr) { | |
136 | case IPPROTO_TCP: { | |
137 | struct tcphdr _tcph, *th; | |
138 | ||
139 | th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); | |
140 | if (th == NULL) | |
141 | break; | |
142 | ||
48c62af6 EP |
143 | ad->u.net->sport = th->source; |
144 | ad->u.net->dport = th->dest; | |
6e837fb1 EB |
145 | break; |
146 | } | |
147 | case IPPROTO_UDP: { | |
148 | struct udphdr _udph, *uh; | |
149 | ||
150 | uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); | |
151 | if (uh == NULL) | |
152 | break; | |
153 | ||
48c62af6 EP |
154 | ad->u.net->sport = uh->source; |
155 | ad->u.net->dport = uh->dest; | |
6e837fb1 EB |
156 | break; |
157 | } | |
158 | case IPPROTO_DCCP: { | |
159 | struct dccp_hdr _dccph, *dh; | |
160 | ||
161 | dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); | |
162 | if (dh == NULL) | |
163 | break; | |
164 | ||
48c62af6 EP |
165 | ad->u.net->sport = dh->dccph_sport; |
166 | ad->u.net->dport = dh->dccph_dport; | |
6e837fb1 EB |
167 | break; |
168 | } | |
169 | case IPPROTO_SCTP: { | |
170 | struct sctphdr _sctph, *sh; | |
171 | ||
172 | sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); | |
173 | if (sh == NULL) | |
174 | break; | |
48c62af6 EP |
175 | ad->u.net->sport = sh->source; |
176 | ad->u.net->dport = sh->dest; | |
6e837fb1 EB |
177 | break; |
178 | } | |
179 | default: | |
180 | ret = -EINVAL; | |
181 | } | |
182 | return ret; | |
183 | } | |
184 | #endif | |
185 | ||
186 | ||
187 | static inline void print_ipv6_addr(struct audit_buffer *ab, | |
188 | struct in6_addr *addr, __be16 port, | |
189 | char *name1, char *name2) | |
190 | { | |
191 | if (!ipv6_addr_any(addr)) | |
d8116591 | 192 | audit_log_format(ab, " %s=%pI6c", name1, addr); |
6e837fb1 EB |
193 | if (port) |
194 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
195 | } | |
196 | ||
197 | static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr, | |
198 | __be16 port, char *name1, char *name2) | |
199 | { | |
200 | if (addr) | |
201 | audit_log_format(ab, " %s=%pI4", name1, &addr); | |
202 | if (port) | |
203 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); | |
204 | } | |
205 | ||
206 | /** | |
207 | * dump_common_audit_data - helper to dump common audit data | |
208 | * @a : common audit data | |
209 | * | |
210 | */ | |
211 | static void dump_common_audit_data(struct audit_buffer *ab, | |
212 | struct common_audit_data *a) | |
213 | { | |
6e837fb1 EB |
214 | struct task_struct *tsk = current; |
215 | ||
07f62eb6 EP |
216 | /* |
217 | * To keep stack sizes in check force programers to notice if they | |
218 | * start making this union too large! See struct lsm_network_audit | |
219 | * as an example of how to deal with large data. | |
220 | */ | |
221 | BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2); | |
222 | ||
f1dc4867 | 223 | audit_log_format(ab, " pid=%d comm=", task_pid_nr(tsk)); |
b466066f | 224 | audit_log_untrustedstring(ab, tsk->comm); |
6e837fb1 EB |
225 | |
226 | switch (a->type) { | |
cb84aa9b | 227 | case LSM_AUDIT_DATA_NONE: |
2bf49690 | 228 | return; |
6e837fb1 EB |
229 | case LSM_AUDIT_DATA_IPC: |
230 | audit_log_format(ab, " key=%d ", a->u.ipc_id); | |
231 | break; | |
232 | case LSM_AUDIT_DATA_CAP: | |
233 | audit_log_format(ab, " capability=%d ", a->u.cap); | |
234 | break; | |
f48b7399 | 235 | case LSM_AUDIT_DATA_PATH: { |
f48b7399 EP |
236 | struct inode *inode; |
237 | ||
c158a35c | 238 | audit_log_d_path(ab, " path=", &a->u.path); |
a269434d EP |
239 | |
240 | inode = a->u.path.dentry->d_inode; | |
41fdc305 KC |
241 | if (inode) { |
242 | audit_log_format(ab, " dev="); | |
243 | audit_log_untrustedstring(ab, inode->i_sb->s_id); | |
244 | audit_log_format(ab, " ino=%lu", inode->i_ino); | |
245 | } | |
a269434d EP |
246 | break; |
247 | } | |
248 | case LSM_AUDIT_DATA_DENTRY: { | |
249 | struct inode *inode; | |
250 | ||
251 | audit_log_format(ab, " name="); | |
252 | audit_log_untrustedstring(ab, a->u.dentry->d_name.name); | |
253 | ||
254 | inode = a->u.dentry->d_inode; | |
41fdc305 KC |
255 | if (inode) { |
256 | audit_log_format(ab, " dev="); | |
257 | audit_log_untrustedstring(ab, inode->i_sb->s_id); | |
258 | audit_log_format(ab, " ino=%lu", inode->i_ino); | |
259 | } | |
6e837fb1 | 260 | break; |
f48b7399 EP |
261 | } |
262 | case LSM_AUDIT_DATA_INODE: { | |
263 | struct dentry *dentry; | |
264 | struct inode *inode; | |
265 | ||
266 | inode = a->u.inode; | |
267 | dentry = d_find_alias(inode); | |
268 | if (dentry) { | |
269 | audit_log_format(ab, " name="); | |
270 | audit_log_untrustedstring(ab, | |
271 | dentry->d_name.name); | |
272 | dput(dentry); | |
273 | } | |
41fdc305 KC |
274 | audit_log_format(ab, " dev="); |
275 | audit_log_untrustedstring(ab, inode->i_sb->s_id); | |
276 | audit_log_format(ab, " ino=%lu", inode->i_ino); | |
f48b7399 EP |
277 | break; |
278 | } | |
6e837fb1 EB |
279 | case LSM_AUDIT_DATA_TASK: |
280 | tsk = a->u.tsk; | |
f1dc4867 RGB |
281 | if (tsk) { |
282 | pid_t pid = task_pid_nr(tsk); | |
283 | if (pid) { | |
284 | audit_log_format(ab, " pid=%d comm=", pid); | |
285 | audit_log_untrustedstring(ab, tsk->comm); | |
286 | } | |
6e837fb1 EB |
287 | } |
288 | break; | |
289 | case LSM_AUDIT_DATA_NET: | |
48c62af6 EP |
290 | if (a->u.net->sk) { |
291 | struct sock *sk = a->u.net->sk; | |
6e837fb1 EB |
292 | struct unix_sock *u; |
293 | int len = 0; | |
294 | char *p = NULL; | |
295 | ||
296 | switch (sk->sk_family) { | |
297 | case AF_INET: { | |
298 | struct inet_sock *inet = inet_sk(sk); | |
299 | ||
c720c7e8 ED |
300 | print_ipv4_addr(ab, inet->inet_rcv_saddr, |
301 | inet->inet_sport, | |
6e837fb1 | 302 | "laddr", "lport"); |
c720c7e8 ED |
303 | print_ipv4_addr(ab, inet->inet_daddr, |
304 | inet->inet_dport, | |
6e837fb1 EB |
305 | "faddr", "fport"); |
306 | break; | |
307 | } | |
c2bb06db | 308 | #if IS_ENABLED(CONFIG_IPV6) |
6e837fb1 EB |
309 | case AF_INET6: { |
310 | struct inet_sock *inet = inet_sk(sk); | |
6e837fb1 | 311 | |
efe4208f | 312 | print_ipv6_addr(ab, &sk->sk_v6_rcv_saddr, |
c720c7e8 | 313 | inet->inet_sport, |
6e837fb1 | 314 | "laddr", "lport"); |
efe4208f | 315 | print_ipv6_addr(ab, &sk->sk_v6_daddr, |
c720c7e8 | 316 | inet->inet_dport, |
6e837fb1 EB |
317 | "faddr", "fport"); |
318 | break; | |
319 | } | |
c2bb06db | 320 | #endif |
6e837fb1 EB |
321 | case AF_UNIX: |
322 | u = unix_sk(sk); | |
40ffe67d AV |
323 | if (u->path.dentry) { |
324 | audit_log_d_path(ab, " path=", &u->path); | |
6e837fb1 EB |
325 | break; |
326 | } | |
327 | if (!u->addr) | |
328 | break; | |
329 | len = u->addr->len-sizeof(short); | |
330 | p = &u->addr->name->sun_path[0]; | |
331 | audit_log_format(ab, " path="); | |
332 | if (*p) | |
333 | audit_log_untrustedstring(ab, p); | |
334 | else | |
335 | audit_log_n_hex(ab, p, len); | |
336 | break; | |
337 | } | |
338 | } | |
339 | ||
48c62af6 | 340 | switch (a->u.net->family) { |
6e837fb1 | 341 | case AF_INET: |
48c62af6 EP |
342 | print_ipv4_addr(ab, a->u.net->v4info.saddr, |
343 | a->u.net->sport, | |
6e837fb1 | 344 | "saddr", "src"); |
48c62af6 EP |
345 | print_ipv4_addr(ab, a->u.net->v4info.daddr, |
346 | a->u.net->dport, | |
6e837fb1 EB |
347 | "daddr", "dest"); |
348 | break; | |
349 | case AF_INET6: | |
48c62af6 EP |
350 | print_ipv6_addr(ab, &a->u.net->v6info.saddr, |
351 | a->u.net->sport, | |
6e837fb1 | 352 | "saddr", "src"); |
48c62af6 EP |
353 | print_ipv6_addr(ab, &a->u.net->v6info.daddr, |
354 | a->u.net->dport, | |
6e837fb1 EB |
355 | "daddr", "dest"); |
356 | break; | |
357 | } | |
48c62af6 | 358 | if (a->u.net->netif > 0) { |
6e837fb1 EB |
359 | struct net_device *dev; |
360 | ||
361 | /* NOTE: we always use init's namespace */ | |
48c62af6 | 362 | dev = dev_get_by_index(&init_net, a->u.net->netif); |
6e837fb1 EB |
363 | if (dev) { |
364 | audit_log_format(ab, " netif=%s", dev->name); | |
365 | dev_put(dev); | |
366 | } | |
367 | } | |
368 | break; | |
369 | #ifdef CONFIG_KEYS | |
370 | case LSM_AUDIT_DATA_KEY: | |
371 | audit_log_format(ab, " key_serial=%u", a->u.key_struct.key); | |
372 | if (a->u.key_struct.key_desc) { | |
373 | audit_log_format(ab, " key_desc="); | |
374 | audit_log_untrustedstring(ab, a->u.key_struct.key_desc); | |
375 | } | |
376 | break; | |
377 | #endif | |
dd8dbf2e EP |
378 | case LSM_AUDIT_DATA_KMOD: |
379 | audit_log_format(ab, " kmod="); | |
380 | audit_log_untrustedstring(ab, a->u.kmod_name); | |
381 | break; | |
6e837fb1 EB |
382 | } /* switch (a->type) */ |
383 | } | |
384 | ||
385 | /** | |
386 | * common_lsm_audit - generic LSM auditing function | |
387 | * @a: auxiliary audit data | |
b61c37f5 LT |
388 | * @pre_audit: lsm-specific pre-audit callback |
389 | * @post_audit: lsm-specific post-audit callback | |
6e837fb1 EB |
390 | * |
391 | * setup the audit buffer for common security information | |
392 | * uses callback to print LSM specific information | |
393 | */ | |
b61c37f5 LT |
394 | void common_lsm_audit(struct common_audit_data *a, |
395 | void (*pre_audit)(struct audit_buffer *, void *), | |
396 | void (*post_audit)(struct audit_buffer *, void *)) | |
6e837fb1 EB |
397 | { |
398 | struct audit_buffer *ab; | |
399 | ||
400 | if (a == NULL) | |
401 | return; | |
402 | /* we use GFP_ATOMIC so we won't sleep */ | |
a20b62bd RGB |
403 | ab = audit_log_start(current->audit_context, GFP_ATOMIC | __GFP_NOWARN, |
404 | AUDIT_AVC); | |
6e837fb1 EB |
405 | |
406 | if (ab == NULL) | |
407 | return; | |
408 | ||
b61c37f5 LT |
409 | if (pre_audit) |
410 | pre_audit(ab, a); | |
6e837fb1 EB |
411 | |
412 | dump_common_audit_data(ab, a); | |
413 | ||
b61c37f5 LT |
414 | if (post_audit) |
415 | post_audit(ab, a); | |
6e837fb1 EB |
416 | |
417 | audit_log_end(ab); | |
418 | } |