xref: /illumos-gate/usr/src/cmd/smbsrv/smbd/smbd_logon.c (revision 437d9da7e4e3aac261d43f722ef702469f5550ce)
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 (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright 2017 Nexenta Systems, Inc.  All rights reserved.
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 <pwd.h>
40 #include <nss_dbdefs.h>
41 #include <sys/idmap.h>
42 #include "smbd.h"
43 
44 
45 /*
46  * An audit session is established at user logon and terminated at user
47  * logoff.
48  *
49  * SMB audit handles are allocated when users logon (SmbSessionSetupX)
50  * and deallocted when a user logs off (SmbLogoffX).  Each time an SMB
51  * audit handle is allocated it is added to a global list.
52  */
53 typedef struct smb_audit {
54 	struct smb_audit *sa_next;
55 	adt_session_data_t *sa_handle;
56 	uid_t sa_uid;
57 	gid_t sa_gid;
58 	uint32_t sa_audit_sid;
59 	uint32_t sa_refcnt;
60 	char *sa_domain;
61 	char *sa_username;
62 } smb_audit_t;
63 
64 static smb_audit_t *smbd_audit_list;
65 static mutex_t smbd_audit_lock;
66 
67 /*
68  * Unique identifier for audit sessions in the audit list.
69  * Used to lookup an audit session on logoff.
70  */
71 static uint32_t smbd_audit_sid;
72 
73 static void smbd_audit_link(smb_audit_t *);
74 static smb_audit_t *smbd_audit_unlink(uint32_t);
75 
76 
77 /*
78  * Invoked at user logon due to SmbSessionSetupX.  Authenticate the
79  * user, start an audit session and audit the event.
80  */
81 smb_token_t *
82 smbd_user_auth_logon(smb_logon_t *user_info)
83 {
84 	smb_token_t *token = NULL;
85 	smb_audit_t *entry;
86 	adt_session_data_t *ah = NULL;
87 	adt_event_data_t *event;
88 	smb_logon_t tmp_user;
89 	au_tid_addr_t termid;
90 	char sidbuf[SMB_SID_STRSZ];
91 	char *username;
92 	char *domain;
93 	uid_t uid;
94 	gid_t gid;
95 	char *sid;
96 	int status;
97 	int retval;
98 	char *p;
99 	char *buf = NULL;
100 
101 	if (user_info->lg_username == NULL ||
102 	    user_info->lg_domain == NULL ||
103 	    user_info->lg_workstation == NULL) {
104 		return (NULL);
105 	}
106 
107 	tmp_user = *user_info;
108 	if (tmp_user.lg_username[0] == '\0') {
109 		tmp_user.lg_flags |= SMB_ATF_ANON;
110 		tmp_user.lg_e_username = "anonymous";
111 	} else {
112 		tmp_user.lg_e_username = tmp_user.lg_username;
113 	}
114 
115 	/* Handle user@domain format. */
116 	if (tmp_user.lg_domain[0] == '\0' &&
117 	    (p = strchr(tmp_user.lg_e_username, '@')) != NULL) {
118 		buf = strdup(tmp_user.lg_e_username);
119 		if (buf == NULL)
120 			goto errout;
121 		p = buf + (p - tmp_user.lg_e_username);
122 		*p = '\0';
123 		tmp_user.lg_e_domain = p + 1;
124 		tmp_user.lg_e_username = buf;
125 	} else {
126 		tmp_user.lg_e_domain = tmp_user.lg_domain;
127 	}
128 
129 	if ((token = smb_logon(&tmp_user)) == NULL) {
130 		uid = ADT_NO_ATTRIB;
131 		gid = ADT_NO_ATTRIB;
132 		sid = NT_NULL_SIDSTR;
133 		username = tmp_user.lg_e_username;
134 		domain = tmp_user.lg_e_domain;
135 		status = ADT_FAILURE;
136 		retval = ADT_FAIL_VALUE_AUTH;
137 	} else {
138 		uid = token->tkn_user.i_id;
139 		gid = token->tkn_primary_grp.i_id;
140 		smb_sid_tostr(token->tkn_user.i_sid, sidbuf);
141 		sid = sidbuf;
142 		username = token->tkn_account_name;
143 		domain = token->tkn_domain_name;
144 		status = ADT_SUCCESS;
145 		retval = ADT_SUCCESS;
146 	}
147 
148 	if (adt_start_session(&ah, NULL, 0)) {
149 		syslog(LOG_AUTH | LOG_ALERT, "adt_start_session: %m");
150 		goto errout;
151 	}
152 
153 	if ((event = adt_alloc_event(ah, ADT_smbd_session)) == NULL) {
154 		syslog(LOG_AUTH | LOG_ALERT,
155 		    "adt_alloc_event(ADT_smbd_session): %m");
156 		goto errout;
157 	}
158 
159 	(void) memset(&termid, 0, sizeof (au_tid_addr_t));
160 	termid.at_port = user_info->lg_local_port;
161 
162 	if (user_info->lg_clnt_ipaddr.a_family == AF_INET) {
163 		termid.at_addr[0] = user_info->lg_clnt_ipaddr.a_ipv4;
164 		termid.at_type = AU_IPv4;
165 	} else {
166 		bcopy(&user_info->lg_clnt_ipaddr.a_ip, termid.at_addr,
167 		    sizeof (in6_addr_t));
168 		termid.at_type = AU_IPv6;
169 	}
170 	adt_set_termid(ah, &termid);
171 
172 	if (adt_set_user(ah, uid, gid, uid, gid, NULL, ADT_NEW)) {
173 		syslog(LOG_AUTH | LOG_ALERT, "adt_set_user: %m");
174 		adt_free_event(event);
175 		goto errout;
176 	}
177 
178 	event->adt_smbd_session.domain = domain;
179 	event->adt_smbd_session.username = username;
180 	event->adt_smbd_session.sid = sid;
181 
182 	if (adt_put_event(event, status, retval))
183 		syslog(LOG_AUTH | LOG_ALERT, "adt_put_event: %m");
184 
185 	adt_free_event(event);
186 
187 	if (token) {
188 		if ((entry = malloc(sizeof (smb_audit_t))) == NULL) {
189 			syslog(LOG_ERR, "smbd_user_auth_logon: %m");
190 			goto errout;
191 		}
192 
193 		entry->sa_handle = ah;
194 		entry->sa_uid = uid;
195 		entry->sa_gid = gid;
196 		entry->sa_username = strdup(username);
197 		entry->sa_domain = strdup(domain);
198 
199 		smb_autohome_add(token);
200 		smbd_audit_link(entry);
201 		token->tkn_audit_sid = entry->sa_audit_sid;
202 	}
203 
204 	free(buf);
205 
206 	return (token);
207 
208 errout:
209 	free(buf);
210 	(void) adt_end_session(ah);
211 	smb_token_destroy(token);
212 	return (NULL);
213 }
214 
215 /*
216  * Logon due to a subsequent SmbSessionSetupX on an existing session.
217  * The user was authenticated during the initial session setup.
218  */
219 void
220 smbd_user_nonauth_logon(uint32_t audit_sid)
221 {
222 	smb_audit_t *entry;
223 
224 	(void) mutex_lock(&smbd_audit_lock);
225 	entry = smbd_audit_list;
226 
227 	while (entry) {
228 		if (entry->sa_audit_sid == audit_sid) {
229 			++entry->sa_refcnt;
230 			break;
231 		}
232 
233 		entry = entry->sa_next;
234 	}
235 
236 	(void) mutex_unlock(&smbd_audit_lock);
237 }
238 
239 /*
240  * Invoked at user logoff due to SmbLogoffX.  If this is the final
241  * logoff for this user on the session, audit the event and terminate
242  * the audit session.
243  */
244 void
245 smbd_user_auth_logoff(uint32_t audit_sid)
246 {
247 	smb_audit_t *entry;
248 	adt_session_data_t *ah;
249 	adt_event_data_t *event;
250 	struct passwd pw;
251 	char buf[NSS_LINELEN_PASSWD];
252 
253 	if ((entry = smbd_audit_unlink(audit_sid)) == NULL)
254 		return;
255 
256 	if (IDMAP_ID_IS_EPHEMERAL(entry->sa_uid)) {
257 		smb_autohome_remove(entry->sa_username);
258 	} else {
259 		if (getpwuid_r(entry->sa_uid, &pw, buf, sizeof (buf)) == NULL)
260 			return;
261 
262 		smb_autohome_remove(pw.pw_name);
263 	}
264 
265 	ah = entry->sa_handle;
266 
267 	if ((event = adt_alloc_event(ah, ADT_smbd_logoff)) == NULL) {
268 		syslog(LOG_AUTH | LOG_ALERT,
269 		    "adt_alloc_event(ADT_smbd_logoff): %m");
270 	} else {
271 		event->adt_smbd_logoff.domain = entry->sa_domain;
272 		event->adt_smbd_logoff.username = entry->sa_username;
273 
274 		if (adt_put_event(event, ADT_SUCCESS, ADT_SUCCESS))
275 			syslog(LOG_AUTH | LOG_ALERT, "adt_put_event: %m");
276 
277 		adt_free_event(event);
278 	}
279 
280 	(void) adt_end_session(ah);
281 
282 	free(entry->sa_username);
283 	free(entry->sa_domain);
284 	free(entry);
285 }
286 
287 /*
288  * Allocate an id and link an audit handle onto the global list.
289  */
290 static void
291 smbd_audit_link(smb_audit_t *entry)
292 {
293 	(void) mutex_lock(&smbd_audit_lock);
294 
295 	do {
296 		++smbd_audit_sid;
297 	} while ((smbd_audit_sid == 0) || (smbd_audit_sid == (uint32_t)-1));
298 
299 	entry->sa_audit_sid = smbd_audit_sid;
300 	entry->sa_refcnt = 1;
301 	entry->sa_next = smbd_audit_list;
302 	smbd_audit_list = entry;
303 
304 	(void) mutex_unlock(&smbd_audit_lock);
305 }
306 
307 /*
308  * Unlink an audit handle.  If the reference count reaches 0, the entry
309  * is removed from the list and returned.  Otherwise the entry remains
310  * on the list and a null pointer is returned.
311  */
312 static smb_audit_t *
313 smbd_audit_unlink(uint32_t audit_sid)
314 {
315 	smb_audit_t *entry;
316 	smb_audit_t **ppe;
317 
318 	(void) mutex_lock(&smbd_audit_lock);
319 	ppe = &smbd_audit_list;
320 
321 	while (*ppe) {
322 		entry = *ppe;
323 
324 		if (entry->sa_audit_sid == audit_sid) {
325 			if (entry->sa_refcnt == 0)
326 				break;
327 
328 			if ((--entry->sa_refcnt) != 0)
329 				break;
330 
331 			*ppe = entry->sa_next;
332 			(void) mutex_unlock(&smbd_audit_lock);
333 			return (entry);
334 		}
335 
336 		ppe = &(*ppe)->sa_next;
337 	}
338 
339 	(void) mutex_unlock(&smbd_audit_lock);
340 	return (NULL);
341 }
342