145916cd2Sjpk /*
245916cd2Sjpk  * CDDL HEADER START
345916cd2Sjpk  *
445916cd2Sjpk  * The contents of this file are subject to the terms of the
545916cd2Sjpk  * Common Development and Distribution License (the "License").
645916cd2Sjpk  * You may not use this file except in compliance with the License.
745916cd2Sjpk  *
845916cd2Sjpk  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
945916cd2Sjpk  * or http://www.opensolaris.org/os/licensing.
1045916cd2Sjpk  * See the License for the specific language governing permissions
1145916cd2Sjpk  * and limitations under the License.
1245916cd2Sjpk  *
1345916cd2Sjpk  * When distributing Covered Code, include this CDDL HEADER in each
1445916cd2Sjpk  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
1545916cd2Sjpk  * If applicable, add the following below this CDDL HEADER, with the
1645916cd2Sjpk  * fields enclosed by brackets "[]" replaced with your own identifying
1745916cd2Sjpk  * information: Portions Copyright [yyyy] [name of copyright owner]
1845916cd2Sjpk  *
1945916cd2Sjpk  * CDDL HEADER END
2045916cd2Sjpk  */
2245916cd2Sjpk /*
2345916cd2Sjpk  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
2445916cd2Sjpk  * Use is subject to license terms.
2545916cd2Sjpk  */
2745916cd2Sjpk #include <door.h>
2845916cd2Sjpk #include <errno.h>
2945916cd2Sjpk #include <fcntl.h>
3045916cd2Sjpk #include <stdio.h>
3145916cd2Sjpk #include <stdlib.h>
3245916cd2Sjpk #include <synch.h>
3345916cd2Sjpk #include <time.h>
3445916cd2Sjpk #include <unistd.h>
3645916cd2Sjpk #include <sys/param.h>
3745916cd2Sjpk #include <sys/stat.h>
3845916cd2Sjpk #include <sys/types.h>
4045916cd2Sjpk #include "labeld.h"
4245916cd2Sjpk #ifndef	DEBUG
4345916cd2Sjpk #define	perror(e)
4445916cd2Sjpk #endif	/* !DEBUG */
4645916cd2Sjpk /*
4745916cd2Sjpk  *	This is cloned from _nsc_trydoorcall used by the nscd client.
4845916cd2Sjpk  *
4945916cd2Sjpk  * Routine that actually performs the door call.
5045916cd2Sjpk  * Note that we cache a file descriptor.  We do
5145916cd2Sjpk  * the following to prevent disasters:
5245916cd2Sjpk  *
5345916cd2Sjpk  * 1) Never use 0, 1 or 2; if we get this from the open
5445916cd2Sjpk  *    we dup it upwards.
5545916cd2Sjpk  *
5645916cd2Sjpk  * 2) Set the close on exec flags so descriptor remains available
5745916cd2Sjpk  *    to child processes.
5845916cd2Sjpk  *
5945916cd2Sjpk  * 3) Verify that the door is still the same one we had before
6045916cd2Sjpk  *    by using door_info on the client side.
6145916cd2Sjpk  *
6245916cd2Sjpk  *	Note that we never close the file descriptor if it isn't one
6345916cd2Sjpk  *	we allocated; we check this with door info.  The rather tricky
6445916cd2Sjpk  *	logic is designed to be fast in the normal case (fd is already
6545916cd2Sjpk  *	allocated and is ok) while handling the case where the application
6645916cd2Sjpk  *	closed it underneath us or where the nscd dies or re-execs itself
6745916cd2Sjpk  *	and we're a multi-threaded application.  Note that we cannot protect
6845916cd2Sjpk  *	the application if it closes the fd and it is multi-threaded.
6945916cd2Sjpk  *
7045916cd2Sjpk  *  int __call_labeld(label_door_op **dptr, int *ndata, int *adata);
7145916cd2Sjpk  *
7245916cd2Sjpk  *      *dptr	IN: points to arg buffer OUT: points to results buffer
7345916cd2Sjpk  *      *ndata	IN: overall size of buffer OUT: overall size of buffer
7445916cd2Sjpk  *      *adata	IN: size of call data OUT: size of return data
7545916cd2Sjpk  *
7645916cd2Sjpk  *  Note that *dptr may change if provided space as defined by *bufsize is
7745916cd2Sjpk  *  inadequate.  In this case the door call mmaps more space and places
7845916cd2Sjpk  *  the answer there and sets dptr to contain a pointer to the space, which
7945916cd2Sjpk  *  should be freed with munmap.
8045916cd2Sjpk  *
8145916cd2Sjpk  *  Returns 0 if the door call reached the server, -1 if contact was not made.
8245916cd2Sjpk  *
8345916cd2Sjpk  */
8645916cd2Sjpk static mutex_t	_door_lock = DEFAULTMUTEX;
8845916cd2Sjpk int
__call_labeld(labeld_data_t ** dptr,size_t * ndata,size_t * adata)8945916cd2Sjpk __call_labeld(labeld_data_t **dptr, size_t *ndata, size_t *adata)
9045916cd2Sjpk {
9145916cd2Sjpk 	static	int 		doorfd = -1;
9245916cd2Sjpk 	static	door_info_t 	real_door;
9345916cd2Sjpk 	struct stat		st;
9445916cd2Sjpk 	door_info_t 		my_door;
9545916cd2Sjpk 	door_arg_t		param;
9645916cd2Sjpk 	char			door_name[MAXPATHLEN];
9745916cd2Sjpk 	struct timespec		ts;
9845916cd2Sjpk 	int			busy = 0;	/* number of busy loops */
10045916cd2Sjpk #ifdef	DEBUG
10145916cd2Sjpk 	labeld_data_t		*callptr = *dptr;
10245916cd2Sjpk 	int			buf_size = *ndata;
10345916cd2Sjpk 	int			return_size = *adata;
10445916cd2Sjpk #endif	/* DEBUG */
10645916cd2Sjpk 	/*
10745916cd2Sjpk 	 * the first time in we try and open and validate the door.
10845916cd2Sjpk 	 * the validations are that the door must have been
10945916cd2Sjpk 	 * created with the label service door cookie and
11045916cd2Sjpk 	 * that it has the same door ID.  If any of these
11145916cd2Sjpk 	 * validations fail we refuse to use the door.
11245916cd2Sjpk 	 */
11345916cd2Sjpk 	ts.tv_sec = 0;		/* initialize nanosecond retry timer */
11445916cd2Sjpk 	ts.tv_nsec = 100;
11545916cd2Sjpk 	(void) mutex_lock(&_door_lock);
11745916cd2Sjpk try_again:
11845916cd2Sjpk 	if (doorfd == -1) {
11945916cd2Sjpk 		int	tbc[3];
12045916cd2Sjpk 		int	i;
12245916cd2Sjpk 		(void) snprintf(door_name, sizeof (door_name), "%s%s",
12345916cd2Sjpk 		    DOOR_PATH, DOOR_NAME);
12445916cd2Sjpk 		if ((doorfd = open64(door_name, O_RDONLY, 0)) < 0) {
12545916cd2Sjpk 			(void) mutex_unlock(&_door_lock);
12645916cd2Sjpk 			perror("server door open");
12745916cd2Sjpk 			return (NOSERVER);
12845916cd2Sjpk 		}
13045916cd2Sjpk 		/*
13145916cd2Sjpk 		 * dup up the file descriptor if we have 0 - 2
13245916cd2Sjpk 		 * to avoid problems with shells stdin/out/err
13345916cd2Sjpk 		 */
13445916cd2Sjpk 		i = 0;
13545916cd2Sjpk 		while (doorfd < 3) { /* we have a reserved fd */
13645916cd2Sjpk 			tbc[i++] = doorfd;
13745916cd2Sjpk 			if ((doorfd = dup(doorfd)) < 0) {
13845916cd2Sjpk 				perror("couldn't dup");
13945916cd2Sjpk 				while (i--)
140*b30a53d0SRichard Lowe 					(void) close(tbc[i]);
14145916cd2Sjpk 				doorfd = -1;
14245916cd2Sjpk 				(void) mutex_unlock(&_door_lock);
14345916cd2Sjpk 				return (NOSERVER);
14445916cd2Sjpk 			}
14545916cd2Sjpk 		}
14645916cd2Sjpk 		while (i--)
147*b30a53d0SRichard Lowe 			(void) close(tbc[i]);
14945916cd2Sjpk 		/*
15045916cd2Sjpk 		 * mark this door descriptor as close on exec
15145916cd2Sjpk 		 */
15245916cd2Sjpk 		(void) fcntl(doorfd, F_SETFD, FD_CLOEXEC);
15345916cd2Sjpk 		if (door_info(doorfd, &real_door) < 0) {
15445916cd2Sjpk 			/*
15545916cd2Sjpk 			 * we should close doorfd because we just opened it
15645916cd2Sjpk 			 */
15745916cd2Sjpk 			perror("real door door_info");
15845916cd2Sjpk 			(void) close(doorfd);
15945916cd2Sjpk 			doorfd = -1;
16045916cd2Sjpk 			(void) mutex_unlock(&_door_lock);
16145916cd2Sjpk 			return (NOSERVER);
16245916cd2Sjpk 		}
16345916cd2Sjpk 		if (fstat(doorfd, &st) < 0) {
16445916cd2Sjpk 			perror("real door fstat");
16545916cd2Sjpk 			return (NOSERVER);
16645916cd2Sjpk 		}
16745916cd2Sjpk #ifdef	DEBUG
16845916cd2Sjpk 		(void) printf("\treal door %s\n", door_name);
16945916cd2Sjpk 		(void) printf("\t\tuid = %d, gid = %d, mode = %o\n", st.st_uid,
17045916cd2Sjpk 		    st.st_gid, st.st_mode);
17145916cd2Sjpk 		(void) printf("\t\toutstanding requests = %d\n", st.st_nlink-1);
17245916cd2Sjpk 		(void) printf("\t\t pid = %d\n", real_door.di_target);
17345916cd2Sjpk 		(void) printf("\t\t procedure = %llx\n", real_door.di_proc);
17445916cd2Sjpk 		(void) printf("\t\t cookie = %llx\n",  real_door.di_data);
17545916cd2Sjpk 		(void) printf("\t\t attributes = %x\n",
17645916cd2Sjpk 		    real_door.di_attributes);
17745916cd2Sjpk 		if (real_door.di_attributes & DOOR_UNREF)
17845916cd2Sjpk 			(void) printf("\t\t\t UNREF\n");
17945916cd2Sjpk 		if (real_door.di_attributes & DOOR_PRIVATE)
18045916cd2Sjpk 			(void) printf("\t\t\t PRIVATE\n");
18145916cd2Sjpk 		if (real_door.di_attributes & DOOR_LOCAL)
18245916cd2Sjpk 			(void) printf("\t\t\t LOCAL\n");
18345916cd2Sjpk 		if (real_door.di_attributes & DOOR_REVOKED)
18445916cd2Sjpk 			(void) printf("\t\t\t REVOKED\n");
18545916cd2Sjpk 		if (real_door.di_attributes & DOOR_DESCRIPTOR)
18645916cd2Sjpk 			(void) printf("\t\t\t DESCRIPTOR\n");
18745916cd2Sjpk 		if (real_door.di_attributes & DOOR_RELEASE)
18845916cd2Sjpk 			(void) printf("\t\t\t RELEASE\n");
18945916cd2Sjpk 		if (real_door.di_attributes & DOOR_DELAY)
19045916cd2Sjpk 			(void) printf("\t\t\t DELAY\n");
19145916cd2Sjpk 		(void) printf("\t\t id = %llx\n", real_door.di_uniquifier);
19245916cd2Sjpk #endif	/* DEBUG */
19345916cd2Sjpk 		if ((real_door.di_attributes & DOOR_REVOKED) ||
194*b30a53d0SRichard Lowe 		    (real_door.di_data != COOKIE)) {
19545916cd2Sjpk #ifdef	DEBUG
19645916cd2Sjpk 			(void) printf("real door revoked\n");
19745916cd2Sjpk #endif	/* DEBUG */
19845916cd2Sjpk 			(void) close(doorfd);
19945916cd2Sjpk 			doorfd = -1;
20045916cd2Sjpk 			(void) mutex_unlock(&_door_lock);
20145916cd2Sjpk 			return (NOSERVER);
20245916cd2Sjpk 		}
20345916cd2Sjpk 	} else {
20445916cd2Sjpk 		if ((door_info(doorfd, &my_door) < 0) ||
205*b30a53d0SRichard Lowe 		    (my_door.di_data != COOKIE) ||
206*b30a53d0SRichard Lowe 		    (my_door.di_uniquifier != real_door.di_uniquifier)) {
20745916cd2Sjpk 			perror("my door door_info");
20845916cd2Sjpk 			/*
20945916cd2Sjpk 			 * don't close it - someone else has clobbered fd
21045916cd2Sjpk 			 */
21145916cd2Sjpk 			doorfd = -1;
21245916cd2Sjpk 			goto try_again;
21345916cd2Sjpk 		}
21445916cd2Sjpk 		if (fstat(doorfd, &st) < 0) {
21545916cd2Sjpk 			perror("my door fstat");
21645916cd2Sjpk 			goto try_again;
21745916cd2Sjpk 		}
21845916cd2Sjpk #ifdef	DEBUG
21945916cd2Sjpk 		(void) sprintf(door_name, "%s%s", DOOR_PATH, DOOR_NAME);
22045916cd2Sjpk 		(void) printf("\tmy door %s\n", door_name);
22145916cd2Sjpk 		(void) printf("\t\tuid = %d, gid = %d, mode = %o\n", st.st_uid,
22245916cd2Sjpk 		    st.st_gid, st.st_mode);
22345916cd2Sjpk 		(void) printf("\t\toutstanding requests = %d\n", st.st_nlink-1);
22445916cd2Sjpk 		(void) printf("\t\t pid = %d\n", my_door.di_target);
22545916cd2Sjpk 		(void) printf("\t\t procedure = %llx\n", my_door.di_proc);
22645916cd2Sjpk 		(void) printf("\t\t cookie = %llx\n",  my_door.di_data);
22745916cd2Sjpk 		(void) printf("\t\t attributes = %x\n", my_door.di_attributes);
22845916cd2Sjpk 		if (my_door.di_attributes & DOOR_UNREF)
22945916cd2Sjpk 			(void) printf("\t\t\t UNREF\n");
23045916cd2Sjpk 		if (my_door.di_attributes & DOOR_PRIVATE)
23145916cd2Sjpk 			(void) printf("\t\t\t PRIVATE\n");
23245916cd2Sjpk 		if (my_door.di_attributes & DOOR_LOCAL)
23345916cd2Sjpk 			(void) printf("\t\t\t LOCAL\n");
23445916cd2Sjpk 		if (my_door.di_attributes & DOOR_REVOKED)
23545916cd2Sjpk 			(void) printf("\t\t\t REVOKED\n");
23645916cd2Sjpk 		if (my_door.di_attributes & DOOR_DESCRIPTOR)
23745916cd2Sjpk 			(void) printf("\t\t\t DESCRIPTOR\n");
23845916cd2Sjpk 		if (my_door.di_attributes & DOOR_RELEASE)
23945916cd2Sjpk 			(void) printf("\t\t\t RELEASE\n");
24045916cd2Sjpk 		if (my_door.di_attributes & DOOR_DELAY)
24145916cd2Sjpk 			(void) printf("\t\t\t DELAY\n");
24245916cd2Sjpk 		(void) printf("\t\t id = %llx\n", my_door.di_uniquifier);
24345916cd2Sjpk #endif	/* DEBUG */
24445916cd2Sjpk 		if (my_door.di_attributes & DOOR_REVOKED) {
24545916cd2Sjpk #ifdef	DEBUG
24645916cd2Sjpk 			(void) printf("my door revoked\n");
24745916cd2Sjpk #endif	/* DEBUG */
24845916cd2Sjpk 			(void) close(doorfd);	/* labeld exited .... */
24945916cd2Sjpk 			doorfd = -1;	/* try and restart connection */
25045916cd2Sjpk 			goto try_again;
25145916cd2Sjpk 		}
25245916cd2Sjpk 	}
25345916cd2Sjpk 	(void) mutex_unlock(&_door_lock);
25545916cd2Sjpk 	param.data_ptr = (char *)*dptr;
25645916cd2Sjpk 	param.data_size = *adata;
25745916cd2Sjpk 	param.desc_ptr = NULL;
25845916cd2Sjpk 	param.desc_num = 0;
25945916cd2Sjpk 	param.rbuf = (char *)*dptr;
26045916cd2Sjpk 	param.rsize = *ndata;
26245916cd2Sjpk 	if (door_call(doorfd, &param) < 0) {
26345916cd2Sjpk 		if (errno == EAGAIN && busy++ < 10) {
26445916cd2Sjpk 			/* adjust backoff */
26545916cd2Sjpk 			if ((ts.tv_nsec *= 10) >= NANOSEC) {
26645916cd2Sjpk 				ts.tv_sec++;
26745916cd2Sjpk 				ts.tv_nsec = 100;
26845916cd2Sjpk 			}
269f841f6adSraf 			(void) nanosleep(&ts, NULL);
27045916cd2Sjpk #ifdef	DEBUG
27145916cd2Sjpk 			(void) printf("door_call failed EAGAIN # %d\n", busy);
27245916cd2Sjpk #endif	/* DEBUG */
27345916cd2Sjpk 			(void) mutex_lock(&_door_lock);
27445916cd2Sjpk 			goto try_again;
27545916cd2Sjpk 		}
27645916cd2Sjpk 		perror("door call");
27745916cd2Sjpk 		return (NOSERVER);
27845916cd2Sjpk 	}
28045916cd2Sjpk 	*adata = (int)param.data_size;
28145916cd2Sjpk 	*ndata = (int)param.rsize;
28245916cd2Sjpk 	/*LINTED*/
28345916cd2Sjpk 	*dptr = (labeld_data_t *)param.data_ptr;
28545916cd2Sjpk 	if (*adata == 0 || *dptr == NULL) {
28645916cd2Sjpk #ifdef	DEBUG
28745916cd2Sjpk 		(void) printf("\tNo data returned, size = %lu, dptr = %p\n",
28845916cd2Sjpk 		    (unsigned long)*adata, (void *)*dptr);
28945916cd2Sjpk #endif	/* DEBUG */
29045916cd2Sjpk 		return (NOSERVER);
29145916cd2Sjpk 	}
29245916cd2Sjpk #ifdef	DEBUG
29345916cd2Sjpk 	(void) printf("call buf = %x, buf size  = %d, call size = %d\n",
29445916cd2Sjpk 	    callptr, buf_size, return_size);
29545916cd2Sjpk 	(void) printf("retn buf = %x, buf size  = %d, retn size = %d\n",
29645916cd2Sjpk 	    *dptr, *ndata, *adata);
29745916cd2Sjpk 	(void) printf("\treply status = %d\n", (*dptr)->param.aret.ret);
29845916cd2Sjpk #endif	/* DEBUG */
29945916cd2Sjpk 	return ((*dptr)->param.aret.ret);
30145916cd2Sjpk }  /* __call_labeld */