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