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-rw-r--r--security/lsm_audit.c386
1 files changed, 386 insertions, 0 deletions
diff --git a/security/lsm_audit.c b/security/lsm_audit.c
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+++ b/security/lsm_audit.c
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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>
17#include <linux/fs.h>
18#include <linux/init.h>
19#include <net/sock.h>
20#include <linux/un.h>
21#include <net/af_unix.h>
22#include <linux/audit.h>
23#include <linux/ipv6.h>
24#include <linux/ip.h>
25#include <net/ip.h>
26#include <net/ipv6.h>
27#include <linux/tcp.h>
28#include <linux/udp.h>
29#include <linux/dccp.h>
30#include <linux/sctp.h>
31#include <linux/lsm_audit.h>
32
33/**
34 * ipv4_skb_to_auditdata : fill auditdata from skb
35 * @skb : the skb
36 * @ad : the audit data to fill
37 * @proto : the layer 4 protocol
38 *
39 * return 0 on success
40 */
41int ipv4_skb_to_auditdata(struct sk_buff *skb,
42 struct common_audit_data *ad, u8 *proto)
43{
44 int ret = 0;
45 struct iphdr *ih;
46
47 ih = ip_hdr(skb);
48 if (ih == NULL)
49 return -EINVAL;
50
51 ad->u.net.v4info.saddr = ih->saddr;
52 ad->u.net.v4info.daddr = ih->daddr;
53
54 if (proto)
55 *proto = ih->protocol;
56 /* non initial fragment */
57 if (ntohs(ih->frag_off) & IP_OFFSET)
58 return 0;
59
60 switch (ih->protocol) {
61 case IPPROTO_TCP: {
62 struct tcphdr *th = tcp_hdr(skb);
63 if (th == NULL)
64 break;
65
66 ad->u.net.sport = th->source;
67 ad->u.net.dport = th->dest;
68 break;
69 }
70 case IPPROTO_UDP: {
71 struct udphdr *uh = udp_hdr(skb);
72 if (uh == NULL)
73 break;
74
75 ad->u.net.sport = uh->source;
76 ad->u.net.dport = uh->dest;
77 break;
78 }
79 case IPPROTO_DCCP: {
80 struct dccp_hdr *dh = dccp_hdr(skb);
81 if (dh == NULL)
82 break;
83
84 ad->u.net.sport = dh->dccph_sport;
85 ad->u.net.dport = dh->dccph_dport;
86 break;
87 }
88 case IPPROTO_SCTP: {
89 struct sctphdr *sh = sctp_hdr(skb);
90 if (sh == NULL)
91 break;
92 ad->u.net.sport = sh->source;
93 ad->u.net.dport = sh->dest;
94 break;
95 }
96 default:
97 ret = -EINVAL;
98 }
99 return ret;
100}
101#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
102/**
103 * ipv6_skb_to_auditdata : fill auditdata from skb
104 * @skb : the skb
105 * @ad : the audit data to fill
106 * @proto : the layer 4 protocol
107 *
108 * return 0 on success
109 */
110int ipv6_skb_to_auditdata(struct sk_buff *skb,
111 struct common_audit_data *ad, u8 *proto)
112{
113 int offset, ret = 0;
114 struct ipv6hdr *ip6;
115 u8 nexthdr;
116
117 ip6 = ipv6_hdr(skb);
118 if (ip6 == NULL)
119 return -EINVAL;
120 ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
121 ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
122 ret = 0;
123 /* IPv6 can have several extension header before the Transport header
124 * skip them */
125 offset = skb_network_offset(skb);
126 offset += sizeof(*ip6);
127 nexthdr = ip6->nexthdr;
128 offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
129 if (offset < 0)
130 return 0;
131 if (proto)
132 *proto = nexthdr;
133 switch (nexthdr) {
134 case IPPROTO_TCP: {
135 struct tcphdr _tcph, *th;
136
137 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
138 if (th == NULL)
139 break;
140
141 ad->u.net.sport = th->source;
142 ad->u.net.dport = th->dest;
143 break;
144 }
145 case IPPROTO_UDP: {
146 struct udphdr _udph, *uh;
147
148 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
149 if (uh == NULL)
150 break;
151
152 ad->u.net.sport = uh->source;
153 ad->u.net.dport = uh->dest;
154 break;
155 }
156 case IPPROTO_DCCP: {
157 struct dccp_hdr _dccph, *dh;
158
159 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
160 if (dh == NULL)
161 break;
162
163 ad->u.net.sport = dh->dccph_sport;
164 ad->u.net.dport = dh->dccph_dport;
165 break;
166 }
167 case IPPROTO_SCTP: {
168 struct sctphdr _sctph, *sh;
169
170 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
171 if (sh == NULL)
172 break;
173 ad->u.net.sport = sh->source;
174 ad->u.net.dport = sh->dest;
175 break;
176 }
177 default:
178 ret = -EINVAL;
179 }
180 return ret;
181}
182#endif
183
184
185static inline void print_ipv6_addr(struct audit_buffer *ab,
186 struct in6_addr *addr, __be16 port,
187 char *name1, char *name2)
188{
189 if (!ipv6_addr_any(addr))
190 audit_log_format(ab, " %s=%pI6", name1, addr);
191 if (port)
192 audit_log_format(ab, " %s=%d", name2, ntohs(port));
193}
194
195static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
196 __be16 port, char *name1, char *name2)
197{
198 if (addr)
199 audit_log_format(ab, " %s=%pI4", name1, &addr);
200 if (port)
201 audit_log_format(ab, " %s=%d", name2, ntohs(port));
202}
203
204/**
205 * dump_common_audit_data - helper to dump common audit data
206 * @a : common audit data
207 *
208 */
209static void dump_common_audit_data(struct audit_buffer *ab,
210 struct common_audit_data *a)
211{
212 struct inode *inode = NULL;
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) {
223 case LSM_AUDIT_DATA_IPC:
224 audit_log_format(ab, " key=%d ", a->u.ipc_id);
225 break;
226 case LSM_AUDIT_DATA_CAP:
227 audit_log_format(ab, " capability=%d ", a->u.cap);
228 break;
229 case LSM_AUDIT_DATA_FS:
230 if (a->u.fs.path.dentry) {
231 struct dentry *dentry = a->u.fs.path.dentry;
232 if (a->u.fs.path.mnt) {
233 audit_log_d_path(ab, "path=", &a->u.fs.path);
234 } else {
235 audit_log_format(ab, " name=");
236 audit_log_untrustedstring(ab,
237 dentry->d_name.name);
238 }
239 inode = dentry->d_inode;
240 } else if (a->u.fs.inode) {
241 struct dentry *dentry;
242 inode = a->u.fs.inode;
243 dentry = d_find_alias(inode);
244 if (dentry) {
245 audit_log_format(ab, " name=");
246 audit_log_untrustedstring(ab,
247 dentry->d_name.name);
248 dput(dentry);
249 }
250 }
251 if (inode)
252 audit_log_format(ab, " dev=%s ino=%lu",
253 inode->i_sb->s_id,
254 inode->i_ino);
255 break;
256 case LSM_AUDIT_DATA_TASK:
257 tsk = a->u.tsk;
258 if (tsk && tsk->pid) {
259 audit_log_format(ab, " pid=%d comm=", tsk->pid);
260 audit_log_untrustedstring(ab, tsk->comm);
261 }
262 break;
263 case LSM_AUDIT_DATA_NET:
264 if (a->u.net.sk) {
265 struct sock *sk = a->u.net.sk;
266 struct unix_sock *u;
267 int len = 0;
268 char *p = NULL;
269
270 switch (sk->sk_family) {
271 case AF_INET: {
272 struct inet_sock *inet = inet_sk(sk);
273
274 print_ipv4_addr(ab, inet->rcv_saddr,
275 inet->sport,
276 "laddr", "lport");
277 print_ipv4_addr(ab, inet->daddr,
278 inet->dport,
279 "faddr", "fport");
280 break;
281 }
282 case AF_INET6: {
283 struct inet_sock *inet = inet_sk(sk);
284 struct ipv6_pinfo *inet6 = inet6_sk(sk);
285
286 print_ipv6_addr(ab, &inet6->rcv_saddr,
287 inet->sport,
288 "laddr", "lport");
289 print_ipv6_addr(ab, &inet6->daddr,
290 inet->dport,
291 "faddr", "fport");
292 break;
293 }
294 case AF_UNIX:
295 u = unix_sk(sk);
296 if (u->dentry) {
297 struct path path = {
298 .dentry = u->dentry,
299 .mnt = u->mnt
300 };
301 audit_log_d_path(ab, "path=", &path);
302 break;
303 }
304 if (!u->addr)
305 break;
306 len = u->addr->len-sizeof(short);
307 p = &u->addr->name->sun_path[0];
308 audit_log_format(ab, " path=");
309 if (*p)
310 audit_log_untrustedstring(ab, p);
311 else
312 audit_log_n_hex(ab, p, len);
313 break;
314 }
315 }
316
317 switch (a->u.net.family) {
318 case AF_INET:
319 print_ipv4_addr(ab, a->u.net.v4info.saddr,
320 a->u.net.sport,
321 "saddr", "src");
322 print_ipv4_addr(ab, a->u.net.v4info.daddr,
323 a->u.net.dport,
324 "daddr", "dest");
325 break;
326 case AF_INET6:
327 print_ipv6_addr(ab, &a->u.net.v6info.saddr,
328 a->u.net.sport,
329 "saddr", "src");
330 print_ipv6_addr(ab, &a->u.net.v6info.daddr,
331 a->u.net.dport,
332 "daddr", "dest");
333 break;
334 }
335 if (a->u.net.netif > 0) {
336 struct net_device *dev;
337
338 /* NOTE: we always use init's namespace */
339 dev = dev_get_by_index(&init_net, a->u.net.netif);
340 if (dev) {
341 audit_log_format(ab, " netif=%s", dev->name);
342 dev_put(dev);
343 }
344 }
345 break;
346#ifdef CONFIG_KEYS
347 case LSM_AUDIT_DATA_KEY:
348 audit_log_format(ab, " key_serial=%u", a->u.key_struct.key);
349 if (a->u.key_struct.key_desc) {
350 audit_log_format(ab, " key_desc=");
351 audit_log_untrustedstring(ab, a->u.key_struct.key_desc);
352 }
353 break;
354#endif
355 } /* switch (a->type) */
356}
357
358/**
359 * common_lsm_audit - generic LSM auditing function
360 * @a: auxiliary audit data
361 *
362 * setup the audit buffer for common security information
363 * uses callback to print LSM specific information
364 */
365void common_lsm_audit(struct common_audit_data *a)
366{
367 struct audit_buffer *ab;
368
369 if (a == NULL)
370 return;
371 /* we use GFP_ATOMIC so we won't sleep */
372 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC);
373
374 if (ab == NULL)
375 return;
376
377 if (a->lsm_pre_audit)
378 a->lsm_pre_audit(ab, a);
379
380 dump_common_audit_data(ab, a);
381
382 if (a->lsm_post_audit)
383 a->lsm_post_audit(ab, a);
384
385 audit_log_end(ab);
386}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-21 18:46:04 -0500