1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/types.h>
27 #include <errno.h>
28 #include <synch.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <unistd.h>
32 #include <string.h>
33 #include <strings.h>
34 #include <syslog.h>
35 #include <fcntl.h>
36 #include <bsm/adt.h>
37 #include <bsm/adt_event.h>
38 #include <bsm/audit_uevents.h>
39 #include "smbd.h"
40 
41 
42 /*
43  * An audit session is established at user logon and terminated at user
44  * logoff.
45  *
46  * SMB audit handles are allocated when users logon (SmbSessionSetupX)
47  * and deallocted when a user logs off (SmbLogoffX).  Each time an SMB
48  * audit handle is allocated it is added to a global list.
49  */
50 typedef struct smb_audit {
51 	struct smb_audit *sa_next;
52 	adt_session_data_t *sa_handle;
53 	uid_t sa_uid;
54 	gid_t sa_gid;
55 	uint32_t sa_audit_sid;
56 	uint32_t sa_refcnt;
57 	char *sa_domain;
58 	char *sa_username;
59 } smb_audit_t;
60 
61 static smb_audit_t *smbd_audit_list;
62 static mutex_t smbd_audit_lock;
63 
64 /*
65  * Unique identifier for audit sessions in the audit list.
66  * Used to lookup an audit session on logoff.
67  */
68 static uint32_t smbd_audit_sid;
69 
70 static void smbd_audit_link(smb_audit_t *);
71 static smb_audit_t *smbd_audit_unlink(uint32_t);
72 
73 
74 /*
75  * Invoked at user logon due to SmbSessionSetupX.  Authenticate the
76  * user, start an audit session and audit the event.
77  */
78 smb_token_t *
79 smbd_user_auth_logon(smb_logon_t *user_info)
80 {
81 	smb_token_t *token;
82 	smb_audit_t *entry;
83 	adt_session_data_t *ah;
84 	adt_event_data_t *event;
85 	au_tid_addr_t termid;
86 	char sidbuf[SMB_SID_STRSZ];
87 	char *username;
88 	char *domain;
89 	uid_t uid;
90 	gid_t gid;
91 	char *sid;
92 	int status;
93 	int retval;
94 
95 	if ((token = smb_logon(user_info)) == NULL) {
96 		uid = ADT_NO_ATTRIB;
97 		gid = ADT_NO_ATTRIB;
98 		sid = NT_NULL_SIDSTR;
99 		username = user_info->lg_e_username;
100 		domain = user_info->lg_e_domain;
101 		status = ADT_FAILURE;
102 		retval = ADT_FAIL_VALUE_AUTH;
103 	} else {
104 		uid = token->tkn_user.i_id;
105 		gid = token->tkn_primary_grp.i_id;
106 		smb_sid_tostr(token->tkn_user.i_sid, sidbuf);
107 		sid = sidbuf;
108 		username = token->tkn_account_name;
109 		domain = token->tkn_domain_name;
110 		status = ADT_SUCCESS;
111 		retval = ADT_SUCCESS;
112 	}
113 
114 	if (adt_start_session(&ah, NULL, 0)) {
115 		syslog(LOG_AUTH | LOG_ALERT, "adt_start_session: %m");
116 		smb_token_destroy(token);
117 		return (NULL);
118 	}
119 
120 	if ((event = adt_alloc_event(ah, ADT_smbd_session)) == NULL) {
121 		syslog(LOG_AUTH | LOG_ALERT,
122 		    "adt_alloc_event(ADT_smbd_session): %m");
123 		(void) adt_end_session(ah);
124 		smb_token_destroy(token);
125 		return (NULL);
126 	}
127 
128 	(void) memset(&termid, 0, sizeof (au_tid_addr_t));
129 	termid.at_port = user_info->lg_local_port;
130 
131 	if (user_info->lg_clnt_ipaddr.a_family == AF_INET) {
132 		termid.at_addr[0] = user_info->lg_clnt_ipaddr.a_ipv4;
133 		termid.at_type = AU_IPv4;
134 	} else {
135 		bcopy(&user_info->lg_clnt_ipaddr.a_ip, termid.at_addr,
136 		    IPV6_ADDR_LEN);
137 		termid.at_type = AU_IPv6;
138 	}
139 	adt_set_termid(ah, &termid);
140 
141 	if (adt_set_user(ah, uid, gid, uid, gid, NULL, ADT_NEW)) {
142 		syslog(LOG_AUTH | LOG_ALERT, "adt_set_user: %m");
143 		adt_free_event(event);
144 		(void) adt_end_session(ah);
145 		smb_token_destroy(token);
146 		return (NULL);
147 	}
148 
149 	event->adt_smbd_session.domain = domain;
150 	event->adt_smbd_session.username = username;
151 	event->adt_smbd_session.sid = sid;
152 
153 	if (adt_put_event(event, status, retval))
154 		syslog(LOG_AUTH | LOG_ALERT, "adt_put_event: %m");
155 
156 	adt_free_event(event);
157 
158 	if (token) {
159 		if ((entry = malloc(sizeof (smb_audit_t))) == NULL) {
160 			syslog(LOG_ERR, "smbd_user_auth_logon: %m");
161 			(void) adt_end_session(ah);
162 			smb_token_destroy(token);
163 			return (NULL);
164 		}
165 
166 		entry->sa_handle = ah;
167 		entry->sa_uid = uid;
168 		entry->sa_gid = gid;
169 		entry->sa_username = strdup(username);
170 		entry->sa_domain = strdup(domain);
171 
172 		smb_autohome_add(token);
173 		smbd_audit_link(entry);
174 		token->tkn_audit_sid = entry->sa_audit_sid;
175 	}
176 
177 	return (token);
178 }
179 
180 /*
181  * Logon due to a subsequent SmbSessionSetupX on an existing session.
182  * The user was authenticated during the initial session setup.
183  */
184 void
185 smbd_user_nonauth_logon(uint32_t audit_sid)
186 {
187 	smb_audit_t *entry;
188 
189 	(void) mutex_lock(&smbd_audit_lock);
190 	entry = smbd_audit_list;
191 
192 	while (entry) {
193 		if (entry->sa_audit_sid == audit_sid) {
194 			++entry->sa_refcnt;
195 			break;
196 		}
197 
198 		entry = entry->sa_next;
199 	}
200 
201 	(void) mutex_unlock(&smbd_audit_lock);
202 }
203 
204 /*
205  * Invoked at user logoff due to SmbLogoffX.  If this is the final
206  * logoff for this user on the session, audit the event and terminate
207  * the audit session.
208  */
209 void
210 smbd_user_auth_logoff(uint32_t audit_sid)
211 {
212 	smb_audit_t *entry;
213 	adt_session_data_t *ah;
214 	adt_event_data_t *event;
215 
216 	if ((entry = smbd_audit_unlink(audit_sid)) == NULL)
217 		return;
218 
219 	smb_autohome_remove(entry->sa_username);
220 
221 	ah = entry->sa_handle;
222 
223 	if ((event = adt_alloc_event(ah, ADT_smbd_logoff)) == NULL) {
224 		syslog(LOG_AUTH | LOG_ALERT,
225 		    "adt_alloc_event(ADT_smbd_logoff): %m");
226 	} else {
227 		event->adt_smbd_logoff.domain = entry->sa_domain;
228 		event->adt_smbd_logoff.username = entry->sa_username;
229 
230 		if (adt_put_event(event, ADT_SUCCESS, ADT_SUCCESS))
231 			syslog(LOG_AUTH | LOG_ALERT, "adt_put_event: %m");
232 
233 		adt_free_event(event);
234 	}
235 
236 	(void) adt_end_session(ah);
237 
238 	free(entry->sa_username);
239 	free(entry->sa_domain);
240 	free(entry);
241 }
242 
243 /*
244  * Allocate an id and link an audit handle onto the global list.
245  */
246 static void
247 smbd_audit_link(smb_audit_t *entry)
248 {
249 	(void) mutex_lock(&smbd_audit_lock);
250 
251 	do {
252 		++smbd_audit_sid;
253 	} while ((smbd_audit_sid == 0) || (smbd_audit_sid == (uint32_t)-1));
254 
255 	entry->sa_audit_sid = smbd_audit_sid;
256 	entry->sa_refcnt = 1;
257 	entry->sa_next = smbd_audit_list;
258 	smbd_audit_list = entry;
259 
260 	(void) mutex_unlock(&smbd_audit_lock);
261 }
262 
263 /*
264  * Unlink an audit handle.  If the reference count reaches 0, the entry
265  * is removed from the list and returned.  Otherwise the entry remains
266  * on the list and a null pointer is returned.
267  */
268 static smb_audit_t *
269 smbd_audit_unlink(uint32_t audit_sid)
270 {
271 	smb_audit_t *entry;
272 	smb_audit_t **ppe;
273 
274 	(void) mutex_lock(&smbd_audit_lock);
275 	ppe = &smbd_audit_list;
276 
277 	while (*ppe) {
278 		entry = *ppe;
279 
280 		if (entry->sa_audit_sid == audit_sid) {
281 			if (entry->sa_refcnt == 0)
282 				break;
283 
284 			if ((--entry->sa_refcnt) != 0)
285 				break;
286 
287 			*ppe = entry->sa_next;
288 			(void) mutex_unlock(&smbd_audit_lock);
289 			return (entry);
290 		}
291 
292 		ppe = &(*ppe)->sa_next;
293 	}
294 
295 	(void) mutex_unlock(&smbd_audit_lock);
296 	return (NULL);
297 }
298