/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <door.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <synch.h>
#include <time.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "labeld.h"
#ifndef DEBUG
#define perror(e)
#endif /* !DEBUG */
/*
* This is cloned from _nsc_trydoorcall used by the nscd client.
*
* Routine that actually performs the door call.
* Note that we cache a file descriptor. We do
* the following to prevent disasters:
*
* 1) Never use 0, 1 or 2; if we get this from the open
* we dup it upwards.
*
* 2) Set the close on exec flags so descriptor remains available
* to child processes.
*
* 3) Verify that the door is still the same one we had before
* by using door_info on the client side.
*
* Note that we never close the file descriptor if it isn't one
* we allocated; we check this with door info. The rather tricky
* logic is designed to be fast in the normal case (fd is already
* allocated and is ok) while handling the case where the application
* closed it underneath us or where the nscd dies or re-execs itself
* and we're a multi-threaded application. Note that we cannot protect
* the application if it closes the fd and it is multi-threaded.
*
* int __call_labeld(label_door_op **dptr, int *ndata, int *adata);
*
* *dptr IN: points to arg buffer OUT: points to results buffer
* *ndata IN: overall size of buffer OUT: overall size of buffer
* *adata IN: size of call data OUT: size of return data
*
* Note that *dptr may change if provided space as defined by *bufsize is
* inadequate. In this case the door call mmaps more space and places
* the answer there and sets dptr to contain a pointer to the space, which
* should be freed with munmap.
*
* Returns 0 if the door call reached the server, -1 if contact was not made.
*
*/
static mutex_t _door_lock = DEFAULTMUTEX;
int
__call_labeld(labeld_data_t **dptr, size_t *ndata, size_t *adata)
{
static int doorfd = -1;
static door_info_t real_door;
struct stat st;
door_info_t my_door;
door_arg_t param;
char door_name[MAXPATHLEN];
struct timespec ts;
int busy = 0; /* number of busy loops */
#ifdef DEBUG
labeld_data_t *callptr = *dptr;
int buf_size = *ndata;
int return_size = *adata;
#endif /* DEBUG */
/*
* the first time in we try and open and validate the door.
* the validations are that the door must have been
* created with the label service door cookie and
* that it has the same door ID. If any of these
* validations fail we refuse to use the door.
*/
ts.tv_sec = 0; /* initialize nanosecond retry timer */
ts.tv_nsec = 100;
(void) mutex_lock(&_door_lock);
try_again:
if (doorfd == -1) {
int tbc[3];
int i;
(void) snprintf(door_name, sizeof (door_name), "%s%s",
DOOR_PATH, DOOR_NAME);
if ((doorfd = open64(door_name, O_RDONLY, 0)) < 0) {
(void) mutex_unlock(&_door_lock);
perror("server door open");
return (NOSERVER);
}
/*
* dup up the file descriptor if we have 0 - 2
* to avoid problems with shells stdin/out/err
*/
i = 0;
while (doorfd < 3) { /* we have a reserved fd */
tbc[i++] = doorfd;
if ((doorfd = dup(doorfd)) < 0) {
perror("couldn't dup");
while (i--)
(void) close(tbc[i]);
doorfd = -1;
(void) mutex_unlock(&_door_lock);
return (NOSERVER);
}
}
while (i--)
(void) close(tbc[i]);
/*
* mark this door descriptor as close on exec
*/
(void) fcntl(doorfd, F_SETFD, FD_CLOEXEC);
if (door_info(doorfd, &real_door) < 0) {
/*
* we should close doorfd because we just opened it
*/
perror("real door door_info");
(void) close(doorfd);
doorfd = -1;
(void) mutex_unlock(&_door_lock);
return (NOSERVER);
}
if (fstat(doorfd, &st) < 0) {
perror("real door fstat");
return (NOSERVER);
}
#ifdef DEBUG
(void) printf("\treal door %s\n", door_name);
(void) printf("\t\tuid = %d, gid = %d, mode = %o\n", st.st_uid,
st.st_gid, st.st_mode);
(void) printf("\t\toutstanding requests = %d\n", st.st_nlink-1);
(void) printf("\t\t pid = %d\n", real_door.di_target);
(void) printf("\t\t procedure = %llx\n", real_door.di_proc);
(void) printf("\t\t cookie = %llx\n", real_door.di_data);
(void) printf("\t\t attributes = %x\n",
real_door.di_attributes);
if (real_door.di_attributes & DOOR_UNREF)
(void) printf("\t\t\t UNREF\n");
if (real_door.di_attributes & DOOR_PRIVATE)
(void) printf("\t\t\t PRIVATE\n");
if (real_door.di_attributes & DOOR_LOCAL)
(void) printf("\t\t\t LOCAL\n");
if (real_door.di_attributes & DOOR_REVOKED)
(void) printf("\t\t\t REVOKED\n");
if (real_door.di_attributes & DOOR_DESCRIPTOR)
(void) printf("\t\t\t DESCRIPTOR\n");
if (real_door.di_attributes & DOOR_RELEASE)
(void) printf("\t\t\t RELEASE\n");
if (real_door.di_attributes & DOOR_DELAY)
(void) printf("\t\t\t DELAY\n");
(void) printf("\t\t id = %llx\n", real_door.di_uniquifier);
#endif /* DEBUG */
if ((real_door.di_attributes & DOOR_REVOKED) ||
(real_door.di_data != COOKIE)) {
#ifdef DEBUG
(void) printf("real door revoked\n");
#endif /* DEBUG */
(void) close(doorfd);
doorfd = -1;
(void) mutex_unlock(&_door_lock);
return (NOSERVER);
}
} else {
if ((door_info(doorfd, &my_door) < 0) ||
(my_door.di_data != COOKIE) ||
(my_door.di_uniquifier != real_door.di_uniquifier)) {
perror("my door door_info");
/*
* don't close it - someone else has clobbered fd
*/
doorfd = -1;
goto try_again;
}
if (fstat(doorfd, &st) < 0) {
perror("my door fstat");
goto try_again;
}
#ifdef DEBUG
(void) sprintf(door_name, "%s%s", DOOR_PATH, DOOR_NAME);
(void) printf("\tmy door %s\n", door_name);
(void) printf("\t\tuid = %d, gid = %d, mode = %o\n", st.st_uid,
st.st_gid, st.st_mode);
(void) printf("\t\toutstanding requests = %d\n", st.st_nlink-1);
(void) printf("\t\t pid = %d\n", my_door.di_target);
(void) printf("\t\t procedure = %llx\n", my_door.di_proc);
(void) printf("\t\t cookie = %llx\n", my_door.di_data);
(void) printf("\t\t attributes = %x\n", my_door.di_attributes);
if (my_door.di_attributes & DOOR_UNREF)
(void) printf("\t\t\t UNREF\n");
if (my_door.di_attributes & DOOR_PRIVATE)
(void) printf("\t\t\t PRIVATE\n");
if (my_door.di_attributes & DOOR_LOCAL)
(void) printf("\t\t\t LOCAL\n");
if (my_door.di_attributes & DOOR_REVOKED)
(void) printf("\t\t\t REVOKED\n");
if (my_door.di_attributes & DOOR_DESCRIPTOR)
(void) printf("\t\t\t DESCRIPTOR\n");
if (my_door.di_attributes & DOOR_RELEASE)
(void) printf("\t\t\t RELEASE\n");
if (my_door.di_attributes & DOOR_DELAY)
(void) printf("\t\t\t DELAY\n");
(void) printf("\t\t id = %llx\n", my_door.di_uniquifier);
#endif /* DEBUG */
if (my_door.di_attributes & DOOR_REVOKED) {
#ifdef DEBUG
(void) printf("my door revoked\n");
#endif /* DEBUG */
(void) close(doorfd); /* labeld exited .... */
doorfd = -1; /* try and restart connection */
goto try_again;
}
}
(void) mutex_unlock(&_door_lock);
param.data_ptr = (char *)*dptr;
param.data_size = *adata;
param.desc_ptr = NULL;
param.desc_num = 0;
param.rbuf = (char *)*dptr;
param.rsize = *ndata;
if (door_call(doorfd, &param) < 0) {
if (errno == EAGAIN && busy++ < 10) {
/* adjust backoff */
if ((ts.tv_nsec *= 10) >= NANOSEC) {
ts.tv_sec++;
ts.tv_nsec = 100;
}
(void) nanosleep(&ts, NULL);
#ifdef DEBUG
(void) printf("door_call failed EAGAIN # %d\n", busy);
#endif /* DEBUG */
(void) mutex_lock(&_door_lock);
goto try_again;
}
perror("door call");
return (NOSERVER);
}
*adata = (int)param.data_size;
*ndata = (int)param.rsize;
/*LINTED*/
*dptr = (labeld_data_t *)param.data_ptr;
if (*adata == 0 || *dptr == NULL) {
#ifdef DEBUG
(void) printf("\tNo data returned, size = %lu, dptr = %p\n",
(unsigned long)*adata, (void *)*dptr);
#endif /* DEBUG */
return (NOSERVER);
}
#ifdef DEBUG
(void) printf("call buf = %x, buf size = %d, call size = %d\n",
callptr, buf_size, return_size);
(void) printf("retn buf = %x, buf size = %d, retn size = %d\n",
*dptr, *ndata, *adata);
(void) printf("\treply status = %d\n", (*dptr)->param.aret.ret);
#endif /* DEBUG */
return ((*dptr)->param.aret.ret);
} /* __call_labeld */