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 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/types.h>
30 #include <pwd.h>
31 #include <stdio.h>
32 #include <synch.h>
33 #include <sys/param.h>
34 #include <fcntl.h>
35 #include <unistd.h>
36 #include "ns_cache_door.h"
37 #include <door.h>
38
39 #if defined(PIC) || defined(lint)
40
41 /*
42 *
43 * Routines that actually performs the door call.
44 * Note that we cache a file descriptor. We do
45 * the following to prevent disasters:
46 *
47 * 1) Never use 0,1 or 2; if we get this from the open
48 * we dup it upwards.
49 *
50 * 2) Set the close on exec flags so descriptor remains available
51 * to child processes.
52 *
53 * 3) Verify that the door is still the same one we had before
54 * by using door_info on the client side.
55 *
56 * Note that we never close the file descriptor if it isn't one
57 * we allocated; we check this with door info. The rather tricky
58 * logic is designed to be fast in the normal case (fd is already
59 * allocated and is ok) while handling the case where the application
60 * closed it underneath us or where the nscd dies or re-execs itself
61 * and we're a multi-threaded application. Note that we cannot protect
62 * the application if it closes the fd and it is multi-threaded.
63 *
64 * int _cache_trydoorcall(void *dptr, int *bufsize, int *actualsize);
65 *
66 * *dptr IN: points to arg buffer OUT: points to results buffer
67 * *bufsize IN: overall size of buffer OUT: overall size of buffer
68 * *actualsize IN: size of call data OUT: size of return data
69 *
70 * Note that *dptr may change if provided space as defined by *bufsize is
71 * inadequate. In this case the door call mmaps more space and places
72 * the answer there and sets dptr to contain a pointer to the space, which
73 * should be freed with munmap.
74 *
75 * Returns 0 if the door call reached the server, -1 if contact was not made.
76 *
77 */
78
79 extern int errno;
80 static mutex_t _door_lock = DEFAULTMUTEX;
81 static int doorfd = -1;
82
83 /*
84 * This function does the first part: ensures a file descriptor is
85 * cached and usable.
86 */
87 int
__ns_ldap_trydoorcall_getfd()88 __ns_ldap_trydoorcall_getfd()
89 {
90 static door_info_t real_door;
91 door_info_t my_door;
92
93 /*
94 * the first time in we try and open and validate the door.
95 * the validations are that the door must have been
96 * created with the name service door cookie and
97 * that the file attached to the door is owned by root
98 * and readonly by user, group and other. If any of these
99 * validations fail we refuse to use the door.
100 */
101
102 (void) mutex_lock(&_door_lock);
103
104 try_again:
105
106 if (doorfd == -1) {
107
108 int tbc[3];
109 int i;
110 if ((doorfd = open(LDAP_CACHE_DOOR, O_RDONLY, 0))
111 == -1) {
112 (void) mutex_unlock(&_door_lock);
113 return (NS_CACHE_NOSERVER);
114 }
115
116 /*
117 * dup up the file descriptor if we have 0 - 2
118 * to avoid problems with shells stdin/out/err
119 */
120 i = 0;
121
122 while (doorfd < 3) { /* we have a reserved fd */
123 tbc[i++] = doorfd;
124 if ((doorfd = dup(doorfd)) < 0) {
125 while (i--)
126 (void) close(tbc[i]);
127 doorfd = -1;
128 (void) mutex_unlock(&_door_lock);
129 return (NS_CACHE_NOSERVER);
130 }
131 }
132
133 while (i--)
134 (void) close(tbc[i]);
135
136 /*
137 * mark this door descriptor as close on exec
138 */
139 (void) fcntl(doorfd, F_SETFD, FD_CLOEXEC);
140 if (door_info(doorfd, &real_door) == -1 ||
141 (real_door.di_attributes & DOOR_REVOKED) ||
142 real_door.di_data != (uintptr_t)LDAP_CACHE_DOOR_COOKIE) {
143 /*
144 * we should close doorfd because we just opened it
145 */
146 (void) close(doorfd);
147 doorfd = -1;
148 (void) mutex_unlock(&_door_lock);
149 return (NS_CACHE_NOSERVER);
150 }
151 } else {
152 if (door_info(doorfd, &my_door) == -1 ||
153 my_door.di_data != (uintptr_t)LDAP_CACHE_DOOR_COOKIE ||
154 my_door.di_uniquifier != real_door.di_uniquifier) {
155 /*
156 * don't close it -
157 * someone else has clobbered fd
158 */
159 doorfd = -1;
160 goto try_again;
161 }
162
163 if (my_door.di_attributes & DOOR_REVOKED) {
164 (void) close(doorfd);
165 doorfd = -1; /* try and restart connection */
166 goto try_again;
167 }
168 }
169
170 (void) mutex_unlock(&_door_lock);
171 return (NS_CACHE_SUCCESS);
172 }
173
174 /*
175 * This function does the second part: sends a door request to
176 * the ldap_cachemgr daemon.
177 */
178 int
__ns_ldap_trydoorcall_send(ldap_data_t ** dptr,int * ndata,int * adata)179 __ns_ldap_trydoorcall_send(ldap_data_t **dptr, int *ndata, int *adata)
180 {
181 door_arg_t param;
182
183 param.rbuf = (char *)*dptr;
184 param.rsize = *ndata;
185 param.data_ptr = (char *)*dptr;
186 param.data_size = *adata;
187 param.desc_ptr = NULL;
188 param.desc_num = 0;
189 if (door_call(doorfd, ¶m) == -1) {
190 return (NS_CACHE_NOSERVER);
191 }
192 *adata = (int)param.data_size;
193 *ndata = (int)param.rsize;
194 *dptr = (ldap_data_t *)param.data_ptr;
195 if (*adata == 0 || *dptr == NULL) {
196 return (NS_CACHE_NOSERVER);
197 }
198
199 return ((*dptr)->ldap_ret.ldap_return_code);
200 }
201
202 /*
203 * This function does part 1 and 2: makes sure a file descriptor is
204 * available and sends a door request to the ldap_cachemgr daemon.
205 */
206 int
__ns_ldap_trydoorcall(ldap_data_t ** dptr,int * ndata,int * adata)207 __ns_ldap_trydoorcall(ldap_data_t **dptr, int *ndata, int *adata)
208 {
209 int rc;
210
211 if ((rc = __ns_ldap_trydoorcall_getfd()) == NS_CACHE_SUCCESS)
212 return (__ns_ldap_trydoorcall_send(dptr, ndata, adata));
213 else
214 return (rc);
215 }
216
217 void
__ns_ldap_doorfd_close()218 __ns_ldap_doorfd_close()
219 {
220 (void) mutex_lock(&_door_lock);
221 if (doorfd != -1) {
222 (void) close(doorfd);
223 }
224 (void) mutex_unlock(&_door_lock);
225 }
226
227 /*
228 * routine to check if server is already running
229 */
230
231 int
__ns_ldap_cache_ping()232 __ns_ldap_cache_ping()
233 {
234 ldap_data_t data;
235 ldap_data_t *dptr;
236 int ndata;
237 int adata;
238
239 data.ldap_call.ldap_callnumber = NULLCALL;
240 ndata = sizeof (data);
241 adata = sizeof (data);
242 dptr = &data;
243 return (__ns_ldap_trydoorcall(&dptr, &ndata, &adata));
244 }
245
246 #endif /* PIC */
247