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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 | { | |
213 | struct inode *inode = NULL; | |
214 | struct task_struct *tsk = current; | |
215 | ||
216 | if (a->tsk) | |
217 | tsk = a->tsk; | |
218 | if (tsk && tsk->pid) { | |
219 | audit_log_format(ab, " pid=%d comm=", tsk->pid); | |
220 | audit_log_untrustedstring(ab, tsk->comm); | |
221 | } | |
222 | ||
223 | switch (a->type) { | |
2bf49690 TL |
224 | case LSM_AUDIT_NO_AUDIT: |
225 | return; | |
6e837fb1 EB |
226 | case LSM_AUDIT_DATA_IPC: |
227 | audit_log_format(ab, " key=%d ", a->u.ipc_id); | |
228 | break; | |
229 | case LSM_AUDIT_DATA_CAP: | |
230 | audit_log_format(ab, " capability=%d ", a->u.cap); | |
231 | break; | |
232 | case LSM_AUDIT_DATA_FS: | |
233 | if (a->u.fs.path.dentry) { | |
234 | struct dentry *dentry = a->u.fs.path.dentry; | |
235 | if (a->u.fs.path.mnt) { | |
236 | audit_log_d_path(ab, "path=", &a->u.fs.path); | |
237 | } else { | |
238 | audit_log_format(ab, " name="); | |
239 | audit_log_untrustedstring(ab, | |
240 | dentry->d_name.name); | |
241 | } | |
242 | inode = dentry->d_inode; | |
243 | } else if (a->u.fs.inode) { | |
244 | struct dentry *dentry; | |
245 | inode = a->u.fs.inode; | |
246 | dentry = d_find_alias(inode); | |
247 | if (dentry) { | |
248 | audit_log_format(ab, " name="); | |
249 | audit_log_untrustedstring(ab, | |
250 | dentry->d_name.name); | |
251 | dput(dentry); | |
252 | } | |
253 | } | |
254 | if (inode) | |
255 | audit_log_format(ab, " dev=%s ino=%lu", | |
256 | inode->i_sb->s_id, | |
257 | inode->i_ino); | |
258 | break; | |
259 | case LSM_AUDIT_DATA_TASK: | |
260 | tsk = a->u.tsk; | |
261 | if (tsk && tsk->pid) { | |
262 | audit_log_format(ab, " pid=%d comm=", tsk->pid); | |
263 | audit_log_untrustedstring(ab, tsk->comm); | |
264 | } | |
265 | break; | |
266 | case LSM_AUDIT_DATA_NET: | |
267 | if (a->u.net.sk) { | |
268 | struct sock *sk = a->u.net.sk; | |
269 | struct unix_sock *u; | |
270 | int len = 0; | |
271 | char *p = NULL; | |
272 | ||
273 | switch (sk->sk_family) { | |
274 | case AF_INET: { | |
275 | struct inet_sock *inet = inet_sk(sk); | |
276 | ||
c720c7e8 ED |
277 | print_ipv4_addr(ab, inet->inet_rcv_saddr, |
278 | inet->inet_sport, | |
6e837fb1 | 279 | "laddr", "lport"); |
c720c7e8 ED |
280 | print_ipv4_addr(ab, inet->inet_daddr, |
281 | inet->inet_dport, | |
6e837fb1 EB |
282 | "faddr", "fport"); |
283 | break; | |
284 | } | |
285 | case AF_INET6: { | |
286 | struct inet_sock *inet = inet_sk(sk); | |
287 | struct ipv6_pinfo *inet6 = inet6_sk(sk); | |
288 | ||
289 | print_ipv6_addr(ab, &inet6->rcv_saddr, | |
c720c7e8 | 290 | inet->inet_sport, |
6e837fb1 EB |
291 | "laddr", "lport"); |
292 | print_ipv6_addr(ab, &inet6->daddr, | |
c720c7e8 | 293 | inet->inet_dport, |
6e837fb1 EB |
294 | "faddr", "fport"); |
295 | break; | |
296 | } | |
297 | case AF_UNIX: | |
298 | u = unix_sk(sk); | |
299 | if (u->dentry) { | |
300 | struct path path = { | |
301 | .dentry = u->dentry, | |
302 | .mnt = u->mnt | |
303 | }; | |
304 | audit_log_d_path(ab, "path=", &path); | |
305 | break; | |
306 | } | |
307 | if (!u->addr) | |
308 | break; | |
309 | len = u->addr->len-sizeof(short); | |
310 | p = &u->addr->name->sun_path[0]; | |
311 | audit_log_format(ab, " path="); | |
312 | if (*p) | |
313 | audit_log_untrustedstring(ab, p); | |
314 | else | |
315 | audit_log_n_hex(ab, p, len); | |
316 | break; | |
317 | } | |
318 | } | |
319 | ||
320 | switch (a->u.net.family) { | |
321 | case AF_INET: | |
322 | print_ipv4_addr(ab, a->u.net.v4info.saddr, | |
323 | a->u.net.sport, | |
324 | "saddr", "src"); | |
325 | print_ipv4_addr(ab, a->u.net.v4info.daddr, | |
326 | a->u.net.dport, | |
327 | "daddr", "dest"); | |
328 | break; | |
329 | case AF_INET6: | |
330 | print_ipv6_addr(ab, &a->u.net.v6info.saddr, | |
331 | a->u.net.sport, | |
332 | "saddr", "src"); | |
333 | print_ipv6_addr(ab, &a->u.net.v6info.daddr, | |
334 | a->u.net.dport, | |
335 | "daddr", "dest"); | |
336 | break; | |
337 | } | |
338 | if (a->u.net.netif > 0) { | |
339 | struct net_device *dev; | |
340 | ||
341 | /* NOTE: we always use init's namespace */ | |
342 | dev = dev_get_by_index(&init_net, a->u.net.netif); | |
343 | if (dev) { | |
344 | audit_log_format(ab, " netif=%s", dev->name); | |
345 | dev_put(dev); | |
346 | } | |
347 | } | |
348 | break; | |
349 | #ifdef CONFIG_KEYS | |
350 | case LSM_AUDIT_DATA_KEY: | |
351 | audit_log_format(ab, " key_serial=%u", a->u.key_struct.key); | |
352 | if (a->u.key_struct.key_desc) { | |
353 | audit_log_format(ab, " key_desc="); | |
354 | audit_log_untrustedstring(ab, a->u.key_struct.key_desc); | |
355 | } | |
356 | break; | |
357 | #endif | |
dd8dbf2e EP |
358 | case LSM_AUDIT_DATA_KMOD: |
359 | audit_log_format(ab, " kmod="); | |
360 | audit_log_untrustedstring(ab, a->u.kmod_name); | |
361 | break; | |
6e837fb1 EB |
362 | } /* switch (a->type) */ |
363 | } | |
364 | ||
365 | /** | |
366 | * common_lsm_audit - generic LSM auditing function | |
367 | * @a: auxiliary audit data | |
368 | * | |
369 | * setup the audit buffer for common security information | |
370 | * uses callback to print LSM specific information | |
371 | */ | |
372 | void common_lsm_audit(struct common_audit_data *a) | |
373 | { | |
374 | struct audit_buffer *ab; | |
375 | ||
376 | if (a == NULL) | |
377 | return; | |
378 | /* we use GFP_ATOMIC so we won't sleep */ | |
379 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); | |
380 | ||
381 | if (ab == NULL) | |
382 | return; | |
383 | ||
384 | if (a->lsm_pre_audit) | |
385 | a->lsm_pre_audit(ab, a); | |
386 | ||
387 | dump_common_audit_data(ab, a); | |
388 | ||
389 | if (a->lsm_post_audit) | |
390 | a->lsm_post_audit(ab, a); | |
391 | ||
392 | audit_log_end(ab); | |
393 | } |