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 2006 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 <door.h>
30 #include <errno.h>
31 #include <fcntl.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <synch.h>
35 #include <time.h>
36 #include <unistd.h>
37
38 #include <sys/param.h>
39 #include <sys/stat.h>
40 #include <sys/types.h>
41
42 #include "labeld.h"
43
44 #ifndef DEBUG
45 #define perror(e)
46 #endif /* !DEBUG */
47
48 /*
49 * This is cloned from _nsc_trydoorcall used by the nscd client.
50 *
51 * Routine that actually performs the door call.
52 * Note that we cache a file descriptor. We do
53 * the following to prevent disasters:
54 *
55 * 1) Never use 0, 1 or 2; if we get this from the open
56 * we dup it upwards.
57 *
58 * 2) Set the close on exec flags so descriptor remains available
59 * to child processes.
60 *
61 * 3) Verify that the door is still the same one we had before
62 * by using door_info on the client side.
63 *
64 * Note that we never close the file descriptor if it isn't one
65 * we allocated; we check this with door info. The rather tricky
66 * logic is designed to be fast in the normal case (fd is already
67 * allocated and is ok) while handling the case where the application
68 * closed it underneath us or where the nscd dies or re-execs itself
69 * and we're a multi-threaded application. Note that we cannot protect
70 * the application if it closes the fd and it is multi-threaded.
71 *
72 * int __call_labeld(label_door_op **dptr, int *ndata, int *adata);
73 *
74 * *dptr IN: points to arg buffer OUT: points to results buffer
75 * *ndata IN: overall size of buffer OUT: overall size of buffer
76 * *adata IN: size of call data OUT: size of return data
77 *
78 * Note that *dptr may change if provided space as defined by *bufsize is
79 * inadequate. In this case the door call mmaps more space and places
80 * the answer there and sets dptr to contain a pointer to the space, which
81 * should be freed with munmap.
82 *
83 * Returns 0 if the door call reached the server, -1 if contact was not made.
84 *
85 */
86
87
88 static mutex_t _door_lock = DEFAULTMUTEX;
89
90 int
__call_labeld(labeld_data_t ** dptr,size_t * ndata,size_t * adata)91 __call_labeld(labeld_data_t **dptr, size_t *ndata, size_t *adata)
92 {
93 static int doorfd = -1;
94 static door_info_t real_door;
95 struct stat st;
96 door_info_t my_door;
97 door_arg_t param;
98 char door_name[MAXPATHLEN];
99 struct timespec ts;
100 int busy = 0; /* number of busy loops */
101
102 #ifdef DEBUG
103 labeld_data_t *callptr = *dptr;
104 int buf_size = *ndata;
105 int return_size = *adata;
106 #endif /* DEBUG */
107
108 /*
109 * the first time in we try and open and validate the door.
110 * the validations are that the door must have been
111 * created with the label service door cookie and
112 * that it has the same door ID. If any of these
113 * validations fail we refuse to use the door.
114 */
115 ts.tv_sec = 0; /* initialize nanosecond retry timer */
116 ts.tv_nsec = 100;
117 (void) mutex_lock(&_door_lock);
118
119 try_again:
120 if (doorfd == -1) {
121 int tbc[3];
122 int i;
123
124 (void) snprintf(door_name, sizeof (door_name), "%s%s",
125 DOOR_PATH, DOOR_NAME);
126 if ((doorfd = open64(door_name, O_RDONLY, 0)) < 0) {
127 (void) mutex_unlock(&_door_lock);
128 perror("server door open");
129 return (NOSERVER);
130 }
131
132 /*
133 * dup up the file descriptor if we have 0 - 2
134 * to avoid problems with shells stdin/out/err
135 */
136 i = 0;
137 while (doorfd < 3) { /* we have a reserved fd */
138 tbc[i++] = doorfd;
139 if ((doorfd = dup(doorfd)) < 0) {
140 perror("couldn't dup");
141 while (i--)
142 (void) close(tbc[i]);
143 doorfd = -1;
144 (void) mutex_unlock(&_door_lock);
145 return (NOSERVER);
146 }
147 }
148 while (i--)
149 (void) close(tbc[i]);
150
151 /*
152 * mark this door descriptor as close on exec
153 */
154 (void) fcntl(doorfd, F_SETFD, FD_CLOEXEC);
155 if (door_info(doorfd, &real_door) < 0) {
156 /*
157 * we should close doorfd because we just opened it
158 */
159 perror("real door door_info");
160 (void) close(doorfd);
161 doorfd = -1;
162 (void) mutex_unlock(&_door_lock);
163 return (NOSERVER);
164 }
165 if (fstat(doorfd, &st) < 0) {
166 perror("real door fstat");
167 return (NOSERVER);
168 }
169 #ifdef DEBUG
170 (void) printf("\treal door %s\n", door_name);
171 (void) printf("\t\tuid = %d, gid = %d, mode = %o\n", st.st_uid,
172 st.st_gid, st.st_mode);
173 (void) printf("\t\toutstanding requests = %d\n", st.st_nlink-1);
174 (void) printf("\t\t pid = %d\n", real_door.di_target);
175 (void) printf("\t\t procedure = %llx\n", real_door.di_proc);
176 (void) printf("\t\t cookie = %llx\n", real_door.di_data);
177 (void) printf("\t\t attributes = %x\n",
178 real_door.di_attributes);
179 if (real_door.di_attributes & DOOR_UNREF)
180 (void) printf("\t\t\t UNREF\n");
181 if (real_door.di_attributes & DOOR_PRIVATE)
182 (void) printf("\t\t\t PRIVATE\n");
183 if (real_door.di_attributes & DOOR_LOCAL)
184 (void) printf("\t\t\t LOCAL\n");
185 if (real_door.di_attributes & DOOR_REVOKED)
186 (void) printf("\t\t\t REVOKED\n");
187 if (real_door.di_attributes & DOOR_DESCRIPTOR)
188 (void) printf("\t\t\t DESCRIPTOR\n");
189 if (real_door.di_attributes & DOOR_RELEASE)
190 (void) printf("\t\t\t RELEASE\n");
191 if (real_door.di_attributes & DOOR_DELAY)
192 (void) printf("\t\t\t DELAY\n");
193 (void) printf("\t\t id = %llx\n", real_door.di_uniquifier);
194 #endif /* DEBUG */
195 if ((real_door.di_attributes & DOOR_REVOKED) ||
196 (real_door.di_data != (door_ptr_t)COOKIE)) {
197 #ifdef DEBUG
198 (void) printf("real door revoked\n");
199 #endif /* DEBUG */
200 (void) close(doorfd);
201 doorfd = -1;
202 (void) mutex_unlock(&_door_lock);
203 return (NOSERVER);
204 }
205 } else {
206 if ((door_info(doorfd, &my_door) < 0) ||
207 (my_door.di_data != (door_ptr_t)COOKIE) ||
208 (my_door.di_uniquifier != real_door.di_uniquifier)) {
209 perror("my door door_info");
210 /*
211 * don't close it - someone else has clobbered fd
212 */
213 doorfd = -1;
214 goto try_again;
215 }
216 if (fstat(doorfd, &st) < 0) {
217 perror("my door fstat");
218 goto try_again;
219 }
220 #ifdef DEBUG
221 (void) sprintf(door_name, "%s%s", DOOR_PATH, DOOR_NAME);
222 (void) printf("\tmy door %s\n", door_name);
223 (void) printf("\t\tuid = %d, gid = %d, mode = %o\n", st.st_uid,
224 st.st_gid, st.st_mode);
225 (void) printf("\t\toutstanding requests = %d\n", st.st_nlink-1);
226 (void) printf("\t\t pid = %d\n", my_door.di_target);
227 (void) printf("\t\t procedure = %llx\n", my_door.di_proc);
228 (void) printf("\t\t cookie = %llx\n", my_door.di_data);
229 (void) printf("\t\t attributes = %x\n", my_door.di_attributes);
230 if (my_door.di_attributes & DOOR_UNREF)
231 (void) printf("\t\t\t UNREF\n");
232 if (my_door.di_attributes & DOOR_PRIVATE)
233 (void) printf("\t\t\t PRIVATE\n");
234 if (my_door.di_attributes & DOOR_LOCAL)
235 (void) printf("\t\t\t LOCAL\n");
236 if (my_door.di_attributes & DOOR_REVOKED)
237 (void) printf("\t\t\t REVOKED\n");
238 if (my_door.di_attributes & DOOR_DESCRIPTOR)
239 (void) printf("\t\t\t DESCRIPTOR\n");
240 if (my_door.di_attributes & DOOR_RELEASE)
241 (void) printf("\t\t\t RELEASE\n");
242 if (my_door.di_attributes & DOOR_DELAY)
243 (void) printf("\t\t\t DELAY\n");
244 (void) printf("\t\t id = %llx\n", my_door.di_uniquifier);
245 #endif /* DEBUG */
246 if (my_door.di_attributes & DOOR_REVOKED) {
247 #ifdef DEBUG
248 (void) printf("my door revoked\n");
249 #endif /* DEBUG */
250 (void) close(doorfd); /* labeld exited .... */
251 doorfd = -1; /* try and restart connection */
252 goto try_again;
253 }
254 }
255 (void) mutex_unlock(&_door_lock);
256
257 param.data_ptr = (char *)*dptr;
258 param.data_size = *adata;
259 param.desc_ptr = NULL;
260 param.desc_num = 0;
261 param.rbuf = (char *)*dptr;
262 param.rsize = *ndata;
263
264 if (door_call(doorfd, ¶m) < 0) {
265 if (errno == EAGAIN && busy++ < 10) {
266 /* adjust backoff */
267 if ((ts.tv_nsec *= 10) >= NANOSEC) {
268 ts.tv_sec++;
269 ts.tv_nsec = 100;
270 }
271 (void) nanosleep(&ts, NULL);
272 #ifdef DEBUG
273 (void) printf("door_call failed EAGAIN # %d\n", busy);
274 #endif /* DEBUG */
275 (void) mutex_lock(&_door_lock);
276 goto try_again;
277 }
278 perror("door call");
279 return (NOSERVER);
280 }
281
282 *adata = (int)param.data_size;
283 *ndata = (int)param.rsize;
284 /*LINTED*/
285 *dptr = (labeld_data_t *)param.data_ptr;
286
287 if (*adata == 0 || *dptr == NULL) {
288 #ifdef DEBUG
289 (void) printf("\tNo data returned, size = %lu, dptr = %p\n",
290 (unsigned long)*adata, (void *)*dptr);
291 #endif /* DEBUG */
292 return (NOSERVER);
293 }
294 #ifdef DEBUG
295 (void) printf("call buf = %x, buf size = %d, call size = %d\n",
296 callptr, buf_size, return_size);
297 (void) printf("retn buf = %x, buf size = %d, retn size = %d\n",
298 *dptr, *ndata, *adata);
299 (void) printf("\treply status = %d\n", (*dptr)->param.aret.ret);
300 #endif /* DEBUG */
301 return ((*dptr)->param.aret.ret);
302
303 } /* __call_labeld */
304