[linux.git] / security / lsm_audit.c

/*
 * common LSM auditing functions
 *
 * Based on code written for SELinux by :
 *			Stephen Smalley, <[email protected]>
 * 			James Morris <[email protected]>
 * Author : Etienne Basset, <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2,
 * as published by the Free Software Foundation.
 */

#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <net/sock.h>
#include <linux/un.h>
#include <net/af_unix.h>
#include <linux/audit.h>
#include <linux/ipv6.h>
#include <linux/ip.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/dccp.h>
#include <linux/sctp.h>
#include <linux/lsm_audit.h>

/**
 * ipv4_skb_to_auditdata : fill auditdata from skb
 * @skb : the skb
 * @ad : the audit data to fill
 * @proto : the layer 4 protocol
 *
 * return  0 on success
 */
int ipv4_skb_to_auditdata(struct sk_buff *skb,
		struct common_audit_data *ad, u8 *proto)
{
	int ret = 0;
	struct iphdr *ih;

	ih = ip_hdr(skb);
	if (ih == NULL)
		return -EINVAL;

	ad->u.net.v4info.saddr = ih->saddr;
	ad->u.net.v4info.daddr = ih->daddr;

	if (proto)
		*proto = ih->protocol;
	/* non initial fragment */
	if (ntohs(ih->frag_off) & IP_OFFSET)
		return 0;

	switch (ih->protocol) {
	case IPPROTO_TCP: {
		struct tcphdr *th = tcp_hdr(skb);
		if (th == NULL)
			break;

		ad->u.net.sport = th->source;
		ad->u.net.dport = th->dest;
		break;
	}
	case IPPROTO_UDP: {
		struct udphdr *uh = udp_hdr(skb);
		if (uh == NULL)
			break;

		ad->u.net.sport = uh->source;
		ad->u.net.dport = uh->dest;
		break;
	}
	case IPPROTO_DCCP: {
		struct dccp_hdr *dh = dccp_hdr(skb);
		if (dh == NULL)
			break;

		ad->u.net.sport = dh->dccph_sport;
		ad->u.net.dport = dh->dccph_dport;
		break;
	}
	case IPPROTO_SCTP: {
		struct sctphdr *sh = sctp_hdr(skb);
		if (sh == NULL)
			break;
		ad->u.net.sport = sh->source;
		ad->u.net.dport = sh->dest;
		break;
	}
	default:
		ret = -EINVAL;
	}
	return ret;
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
/**
 * ipv6_skb_to_auditdata : fill auditdata from skb
 * @skb : the skb
 * @ad : the audit data to fill
 * @proto : the layer 4 protocol
 *
 * return  0 on success
 */
int ipv6_skb_to_auditdata(struct sk_buff *skb,
		struct common_audit_data *ad, u8 *proto)
{
	int offset, ret = 0;
	struct ipv6hdr *ip6;
	u8 nexthdr;

	ip6 = ipv6_hdr(skb);
	if (ip6 == NULL)
		return -EINVAL;
	ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
	ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
	ret = 0;
	/* IPv6 can have several extension header before the Transport header
	 * skip them */
	offset = skb_network_offset(skb);
	offset += sizeof(*ip6);
	nexthdr = ip6->nexthdr;
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
	if (offset < 0)
		return 0;
	if (proto)
		*proto = nexthdr;
	switch (nexthdr) {
	case IPPROTO_TCP: {
		struct tcphdr _tcph, *th;

		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
		if (th == NULL)
			break;

		ad->u.net.sport = th->source;
		ad->u.net.dport = th->dest;
		break;
	}
	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
		if (uh == NULL)
			break;

		ad->u.net.sport = uh->source;
		ad->u.net.dport = uh->dest;
		break;
	}
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
		if (dh == NULL)
			break;

		ad->u.net.sport = dh->dccph_sport;
		ad->u.net.dport = dh->dccph_dport;
		break;
	}
	case IPPROTO_SCTP: {
		struct sctphdr _sctph, *sh;

		sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
		if (sh == NULL)
			break;
		ad->u.net.sport = sh->source;
		ad->u.net.dport = sh->dest;
		break;
	}
	default:
		ret = -EINVAL;
	}
	return ret;
}
#endif


static inline void print_ipv6_addr(struct audit_buffer *ab,
				   struct in6_addr *addr, __be16 port,
				   char *name1, char *name2)
{
	if (!ipv6_addr_any(addr))
		audit_log_format(ab, " %s=%pI6", name1, addr);
	if (port)
		audit_log_format(ab, " %s=%d", name2, ntohs(port));
}

static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
				   __be16 port, char *name1, char *name2)
{
	if (addr)
		audit_log_format(ab, " %s=%pI4", name1, &addr);
	if (port)
		audit_log_format(ab, " %s=%d", name2, ntohs(port));
}

/**
 * dump_common_audit_data - helper to dump common audit data
 * @a : common audit data
 *
 */
static void dump_common_audit_data(struct audit_buffer *ab,
				   struct common_audit_data *a)
{
	struct inode *inode = NULL;
	struct task_struct *tsk = current;

	if (a->tsk)
		tsk = a->tsk;
	if (tsk && tsk->pid) {
		audit_log_format(ab, " pid=%d comm=", tsk->pid);
		audit_log_untrustedstring(ab, tsk->comm);
	}

	switch (a->type) {
	case LSM_AUDIT_DATA_IPC:
		audit_log_format(ab, " key=%d ", a->u.ipc_id);
		break;
	case LSM_AUDIT_DATA_CAP:
		audit_log_format(ab, " capability=%d ", a->u.cap);
		break;
	case LSM_AUDIT_DATA_FS:
		if (a->u.fs.path.dentry) {
			struct dentry *dentry = a->u.fs.path.dentry;
			if (a->u.fs.path.mnt) {
				audit_log_d_path(ab, "path=", &a->u.fs.path);
			} else {
				audit_log_format(ab, " name=");
				audit_log_untrustedstring(ab,
						 dentry->d_name.name);
			}
			inode = dentry->d_inode;
		} else if (a->u.fs.inode) {
			struct dentry *dentry;
			inode = a->u.fs.inode;
			dentry = d_find_alias(inode);
			if (dentry) {
				audit_log_format(ab, " name=");
				audit_log_untrustedstring(ab,
						 dentry->d_name.name);
				dput(dentry);
			}
		}
		if (inode)
			audit_log_format(ab, " dev=%s ino=%lu",
					inode->i_sb->s_id,
					inode->i_ino);
		break;
	case LSM_AUDIT_DATA_TASK:
		tsk = a->u.tsk;
		if (tsk && tsk->pid) {
			audit_log_format(ab, " pid=%d comm=", tsk->pid);
			audit_log_untrustedstring(ab, tsk->comm);
		}
		break;
	case LSM_AUDIT_DATA_NET:
		if (a->u.net.sk) {
			struct sock *sk = a->u.net.sk;
			struct unix_sock *u;
			int len = 0;
			char *p = NULL;

			switch (sk->sk_family) {
			case AF_INET: {
				struct inet_sock *inet = inet_sk(sk);

				print_ipv4_addr(ab, inet->rcv_saddr,
						inet->sport,
						"laddr", "lport");
				print_ipv4_addr(ab, inet->daddr,
						inet->dport,
						"faddr", "fport");
				break;
			}
			case AF_INET6: {
				struct inet_sock *inet = inet_sk(sk);
				struct ipv6_pinfo *inet6 = inet6_sk(sk);

				print_ipv6_addr(ab, &inet6->rcv_saddr,
						inet->sport,
						"laddr", "lport");
				print_ipv6_addr(ab, &inet6->daddr,
						inet->dport,
						"faddr", "fport");
				break;
			}
			case AF_UNIX:
				u = unix_sk(sk);
				if (u->dentry) {
					struct path path = {
						.dentry = u->dentry,
						.mnt = u->mnt
					};
					audit_log_d_path(ab, "path=", &path);
					break;
				}
				if (!u->addr)
					break;
				len = u->addr->len-sizeof(short);
				p = &u->addr->name->sun_path[0];
				audit_log_format(ab, " path=");
				if (*p)
					audit_log_untrustedstring(ab, p);
				else
					audit_log_n_hex(ab, p, len);
				break;
			}
		}

		switch (a->u.net.family) {
		case AF_INET:
			print_ipv4_addr(ab, a->u.net.v4info.saddr,
					a->u.net.sport,
					"saddr", "src");
			print_ipv4_addr(ab, a->u.net.v4info.daddr,
					a->u.net.dport,
					"daddr", "dest");
			break;
		case AF_INET6:
			print_ipv6_addr(ab, &a->u.net.v6info.saddr,
					a->u.net.sport,
					"saddr", "src");
			print_ipv6_addr(ab, &a->u.net.v6info.daddr,
					a->u.net.dport,
					"daddr", "dest");
			break;
		}
		if (a->u.net.netif > 0) {
			struct net_device *dev;

			/* NOTE: we always use init's namespace */
			dev = dev_get_by_index(&init_net, a->u.net.netif);
			if (dev) {
				audit_log_format(ab, " netif=%s", dev->name);
				dev_put(dev);
			}
		}
		break;
#ifdef CONFIG_KEYS
	case LSM_AUDIT_DATA_KEY:
		audit_log_format(ab, " key_serial=%u", a->u.key_struct.key);
		if (a->u.key_struct.key_desc) {
			audit_log_format(ab, " key_desc=");
			audit_log_untrustedstring(ab, a->u.key_struct.key_desc);
		}
		break;
#endif
	} /* switch (a->type) */
}

/**
 * common_lsm_audit - generic LSM auditing function
 * @a:  auxiliary audit data
 *
 * setup the audit buffer for common security information
 * uses callback to print LSM specific information
 */
void common_lsm_audit(struct common_audit_data *a)
{
	struct audit_buffer *ab;

	if (a == NULL)
		return;
	/* we use GFP_ATOMIC so we won't sleep */
	ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC);

	if (ab == NULL)
		return;

	if (a->lsm_pre_audit)
		a->lsm_pre_audit(ab, a);

	dump_common_audit_data(ab, a);

	if (a->lsm_post_audit)
		a->lsm_post_audit(ab, a);

	audit_log_end(ab);
}
Commit	Line	Data
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>
	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	}