Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6.git] / security / lsm_audit.c
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  */
41 int 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  */
110 int 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
185 static 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
195 static 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  */
209 static 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  */
365 void 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 }