OpenSolaris_b135/cmd/ldapcachemgr/cachemgr_change.c
/*
* 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 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <strings.h>
#include <stdlib.h>
#include <syslog.h>
#include <errno.h>
#include <libintl.h>
#include <door.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <procfs.h>
#include "cachemgr.h"
extern admin_t current_admin;
#define CLEANUP_WAIT_TIME 60
typedef enum cleanup_type {
CLEANUP_ALL = 1,
CLEANUP_BY_PID = 2
} cleanup_type_t;
typedef struct cleanup_op {
pid_t pid;
cleanup_type_t type;
} cleanup_op_t;
typedef struct main_nscd_struct {
pid_t pid; /* main nscd pid */
thread_t tid; /* main nscd tid */
int in_progress; /* A main nscd thread is */
/* waiting for change or */
/* copying data */
int is_waiting_cleanup; /* A main nscd thread is */
/* waiting for another main */
/* nscd thread to be cleaned */
/* up */
} main_nscd_t;
static chg_info_t chg = { DEFAULTMUTEX, DEFAULTCV, 0, NULL, NULL, NULL, 0 };
static main_nscd_t chg_main_nscd = {0, 0, 0, 0};
static mutex_t chg_main_nscd_lock = DEFAULTMUTEX;
static cond_t chg_main_nscd_cv = DEFAULTCV;
/*
* The cookie of the configuration and its mutex
*/
static ldap_get_chg_cookie_t config_cookie = {0, 0};
static mutex_t config_cookie_lock = DEFAULTMUTEX;
static void cleanup_thread_by_pid(pid_t pid);
ldap_get_chg_cookie_t
chg_config_cookie_get(void)
{
ldap_get_chg_cookie_t cookie;
(void) mutex_lock(&config_cookie_lock);
cookie = config_cookie;
(void) mutex_unlock(&config_cookie_lock);
return (cookie);
}
static void
chg_config_cookie_increment_seq_num(void)
{
(void) mutex_lock(&config_cookie_lock);
config_cookie.seq_num++;
(void) mutex_unlock(&config_cookie_lock);
}
void
chg_config_cookie_set(ldap_get_chg_cookie_t *cookie)
{
(void) mutex_lock(&config_cookie_lock);
config_cookie.mgr_pid = cookie->mgr_pid;
config_cookie.seq_num = cookie->seq_num;
(void) mutex_unlock(&config_cookie_lock);
}
static boolean_t
chg_cookie_equal(ldap_get_chg_cookie_t *c1, ldap_get_chg_cookie_t *c2)
{
if (c1->mgr_pid == c2->mgr_pid && c1->seq_num == c2->seq_num)
return (B_TRUE);
else
return (B_FALSE);
}
/*
* Create a node in the list and output the node. The caller can NOT free it.
*/
static int
waiting_list_add(chg_info_t *info, pid_t pid, thread_t tid,
waiting_list_t **wlp)
{
waiting_list_t *wl;
*wlp = NULL;
if ((wl = (waiting_list_t *)calloc(1, sizeof (waiting_list_t)))
== NULL) {
logit("waiting_list_add: No memory. pid %ld tid %d\n",
pid, tid);
return (CHG_NO_MEMORY);
}
wl->pid = pid;
wl->tid = tid;
if (info->chg_w_first == NULL) {
info->chg_w_first = wl;
info->chg_w_last = wl;
} else {
info->chg_w_last->next = wl;
wl->prev = info->chg_w_last;
info->chg_w_last = wl;
}
*wlp = wl;
return (CHG_SUCCESS);
}
/*
* Find a node with matching tid in the list and remove it from the list.
*/
static int
waiting_list_delete(chg_info_t *info, thread_t tid)
{
waiting_list_t *wl;
for (wl = info->chg_w_first; wl != NULL; wl = wl->next) {
if (wl->tid == tid) {
if (wl->next == NULL) {
if (wl->prev == NULL) {
info->chg_w_first = NULL;
info->chg_w_last = NULL;
} else {
wl->prev->next = NULL;
info->chg_w_last = wl->prev;
}
} else {
if (wl->prev == NULL) {
wl->next->prev = NULL;
info->chg_w_first = wl->next;
} else {
wl->prev->next = wl->next;
wl->next->prev = wl->prev;
}
}
free(wl);
return (CHG_SUCCESS);
}
}
return (CHG_NOT_FOUND_IN_WAITING_LIST);
}
/*
* Delete the thread from the waiting list and remove data when the list
* is empty.
*/
static void
waiting_list_cleanup(chg_info_t *chg, thread_t tid)
{
int rc;
rc = waiting_list_delete(chg, tid);
if (rc == CHG_SUCCESS && chg->chg_w_first == NULL) {
free(chg->chg_data);
chg->chg_data = NULL;
chg->chg_wakeup = 0;
}
}
/*
* Set flag by pid so it can be cleaned up.
*/
static void
waiting_list_set_cleanup(chg_info_t *info, pid_t pid)
{
waiting_list_t *wl;
for (wl = info->chg_w_first; wl != NULL; wl = wl->next) {
if (wl->pid == pid) {
wl->cleanup = 1;
break;
}
}
}
/*
* Return: 1 - door client is dead, 0 - door client is alive
*/
static int
door_client_dead(void)
{
ucred_t *uc = NULL;
int rc;
if (door_ucred(&uc) == -1 && errno == EINVAL) {
rc = 1;
} else {
rc = 0;
}
if (uc)
ucred_free(uc);
return (rc);
}
/*
* This function handles GETSTATUSCHANGE call from main nscd.
* The call can be a START op or STOP op. A cookie is sent from main nscd too.
* The static global variable main_nscd keeps record of pid, tid and some flags.
* If the thread is door_return(), main_nscd.pid, main_nscd.tid are set to 0.
* When the call is START op, it checks if main_nscd.pid is 0. If it is, it
* proceeds to wait for the change notification. If it's not, which means
* another main nscd handling thread is still around. It sends broadcast to
* clean up that thread and wait until the cleanup is done then proceeds to
* wait for the change notification. If same main nscd sends START op
* repeatedly, it'll be rejected.
* It also checks the cookie from main nscd. If it's not the same as
* ldap_cachemgr's cookie, door returns config change.
* If the door call is STOP op, it creates a thread to clean up main nscd START
* thread so it won't be blocking.
* In waiting for the change notification phase, the thread is waken up by
* the notification threads or by the cleanup threads.
* If it's a notification, it copies data to the stack then door return.
* If it's a cleanup, door_client_dead() is called to verify it then
* door return.
*/
int
chg_get_statusChange(LineBuf *info, ldap_call_t *in, pid_t nscd_pid)
{
int rc = CHG_SUCCESS, another_main_nscd_thread_alive = 0;
int len, return_now;
thread_t this_tid = thr_self();
waiting_list_t *wl = NULL;
ldap_get_change_out_t *cout;
ldap_get_chg_cookie_t cookie;
info->str = NULL;
info->len = 0;
if (in->ldap_u.get_change.op == NS_STATUS_CHANGE_OP_START) {
(void) mutex_lock(&chg_main_nscd_lock);
if (chg_main_nscd.pid != 0) {
if (nscd_pid != chg_main_nscd.pid) {
/*
* This is the case that nscd doesn't shut down
* properly(e.g. core) and STOP op is not sent,
* the thread handling it is still around and
* not cleaned up yet.
* Test if the thread is still alive.
* If it is, clean it up.
* For thr_kill, if sig is 0, a validity check
* is done for the existence of the target
* thread; no signal is sent.
*/
if (thr_kill(chg_main_nscd.tid, 0) == 0) {
another_main_nscd_thread_alive = 1;
cleanup_thread_by_pid(
chg_main_nscd.pid);
}
} else if (chg_main_nscd.in_progress ||
chg_main_nscd.is_waiting_cleanup) {
/*
* Same nscd pid can only send door call
* one at a time and wait for ldap_cachemgr to
* return change data. If it's the same pid
* again, it's an nscd error.
*/
(void) mutex_unlock(&chg_main_nscd_lock);
return (CHG_NSCD_REPEATED_CALL);
}
}
/*
* Wait for another thread to be cleaned up if it's alive.
* After that this cond var is waken up.
*/
if (another_main_nscd_thread_alive) {
while (chg_main_nscd.in_progress) {
chg_main_nscd.is_waiting_cleanup = 1;
(void) cond_wait(&chg_main_nscd_cv,
&chg_main_nscd_lock);
}
}
/*
* Replace pid and tid and set the flag.
*/
chg_main_nscd.is_waiting_cleanup = 0;
chg_main_nscd.pid = nscd_pid;
chg_main_nscd.tid = this_tid;
chg_main_nscd.in_progress = 1;
(void) mutex_unlock(&chg_main_nscd_lock);
cookie = chg_config_cookie_get();
if (!chg_cookie_equal(&cookie, &in->ldap_u.get_change.cookie)) {
/*
* different cookie, set new cookie and
* return door call right away
*/
len = sizeof (ldap_get_change_out_t);
if ((cout = calloc(1, len)) == NULL) {
rc = CHG_NO_MEMORY;
} else {
cout->type = NS_STATUS_CHANGE_TYPE_CONFIG;
cout->cookie = cookie;
info->str = (char *)cout;
info->len = len;
}
} else {
(void) mutex_lock(&chg.chg_lock);
/* wait for the change notification */
rc = waiting_list_add(&chg, nscd_pid, this_tid, &wl);
if (rc == CHG_SUCCESS) {
return_now = 0;
while (!chg.chg_wakeup) {
if (wl->cleanup ||
door_client_dead()) {
return_now = 1;
break;
}
(void) cond_wait(&chg.chg_cv,
&chg.chg_lock);
}
/* Check if door client is still alive again */
if (!return_now && !wl->cleanup &&
!door_client_dead()) {
/* copy data to buffer */
if ((info->str = malloc(
chg.chg_data_size)) == NULL) {
rc = CHG_NO_MEMORY;
} else {
(void) memcpy(info->str,
chg.chg_data,
chg.chg_data_size);
info->len = chg.chg_data_size;
}
}
waiting_list_cleanup(&chg, this_tid);
}
(void) mutex_unlock(&chg.chg_lock);
}
/*
* Reset pid, tid and flag, send wakeup signal.
*/
(void) mutex_lock(&chg_main_nscd_lock);
chg_main_nscd.pid = 0;
chg_main_nscd.tid = 0;
chg_main_nscd.in_progress = 0;
if (chg_main_nscd.is_waiting_cleanup)
(void) cond_broadcast(&chg_main_nscd_cv);
(void) mutex_unlock(&chg_main_nscd_lock);
} else if (in->ldap_u.get_change.op == NS_STATUS_CHANGE_OP_STOP) {
cleanup_thread_by_pid(nscd_pid);
rc = CHG_SUCCESS;
} else {
rc = CHG_INVALID_PARAM;
}
if (rc == CHG_EXCEED_MAX_THREADS)
cleanup_thread_by_pid(0);
return (rc);
}
/*
* This function copies the header and data stream to the buffer
* then send broadcast to wake up the chg_get_statusChange() threads.
*/
int
chg_notify_statusChange(char *str)
{
ldap_get_change_out_t *cout = (ldap_get_change_out_t *)str;
cout->cookie = chg_config_cookie_get();
(void) mutex_lock(&chg.chg_lock);
if (chg.chg_w_first != NULL && chg.chg_wakeup == 0) {
if (chg.chg_data) {
free(chg.chg_data);
chg.chg_data = NULL;
}
chg.chg_data = str;
if (cout->type == NS_STATUS_CHANGE_TYPE_CONFIG)
chg.chg_data_size = sizeof (ldap_get_change_out_t);
else
/* NS_STATUS_CHANGE_TYPE_SERVER */
chg.chg_data_size = sizeof (ldap_get_change_out_t) -
sizeof (int) + cout->data_size;
chg.chg_wakeup = 1;
(void) cond_broadcast(&chg.chg_cv);
}
(void) mutex_unlock(&chg.chg_lock);
return (CHG_SUCCESS);
}
/*
* This is called when the configuration is refreshed.
* The new configuration is different from the current one, a notification
* is sent tochg_get_statusChange() threads.
*/
void
chg_test_config_change(ns_config_t *new, int *change_status)
{
int changed = 0;
LineBuf new_cfg, cur_cfg;
ns_ldap_error_t *errp = NULL;
ldap_config_out_t *new_out, *cur_out;
ldap_get_change_out_t *cout;
(void) memset(&new_cfg, 0, sizeof (LineBuf));
(void) memset(&cur_cfg, 0, sizeof (LineBuf));
/*
* Flatten the config data of the newly downloaded config and
* current default config and compare both.
*/
if ((errp = __ns_ldap_LoadDoorInfo(&new_cfg, NULL, new, 0)) != NULL) {
__ns_ldap_freeError(&errp);
/* error, assume the config is changed */
changed = 1;
} else if ((errp = __ns_ldap_LoadDoorInfo(&cur_cfg, NULL, NULL, 0))
!= NULL) {
__ns_ldap_freeError(&errp);
/* error, assume the config is changed */
changed = 1;
}
if (changed == 0) {
new_out = (ldap_config_out_t *)new_cfg.str;
cur_out = (ldap_config_out_t *)cur_cfg.str;
if (strcmp(new_out->config_str, cur_out->config_str) != 0) {
changed = 1;
if (current_admin.debug_level >= DBG_PROFILE_REFRESH) {
logit("config changed.\n");
}
}
}
if (cur_cfg.str)
free(cur_cfg.str);
if (new_cfg.str)
free(new_cfg.str);
if (changed) {
if ((cout = calloc(1, sizeof (ldap_get_change_out_t)))
== NULL) {
logit("chg_test_config_change: No Memory\n");
} else {
/*
* Replace the currentdefault config with the new
* config
*/
__s_api_init_config(new);
chg_config_cookie_increment_seq_num();
cout->type = NS_STATUS_CHANGE_TYPE_CONFIG;
/*
* cout->cookie is set by
* chg_notify_statusChange
*/
(void) chg_notify_statusChange((char *)cout);
}
} else {
__s_api_destroy_config(new);
}
*change_status = changed;
}
/*
* Wake up chg_get_statusChange() threads to clean up the threads
* that main nscd doesn't exist on the other of door anymore or
* the thread is marked as cleanup.
*/
static void
cleanup_threads(chg_info_t *chg, pid_t pid, cleanup_type_t type)
{
(void) mutex_lock(&chg->chg_lock);
if (type == CLEANUP_BY_PID)
waiting_list_set_cleanup(chg, pid);
/*
* wake up threads without setting chg.chg_wakeup.
* It's for cleanup purpose, not for notifying changes.
*/
(void) cond_broadcast(&chg->chg_cv);
(void) mutex_unlock(&chg->chg_lock);
}
/*
* If arg is NULL, it loops forever,
* else it calls cleanup_threads once and exits.
*/
void *
chg_cleanup_waiting_threads(void *arg)
{
cleanup_op_t *op = (cleanup_op_t *)arg;
cleanup_type_t type = 0;
pid_t pid;
int always = 1, waiting;
if (op == NULL) {
waiting = 1;
type = CLEANUP_ALL;
pid = 0;
} else {
waiting = 0;
type = op->type;
pid = op->pid;
}
while (always) {
if (waiting)
(void) sleep(CLEANUP_WAIT_TIME);
cleanup_threads(&chg, pid, type);
if (!waiting)
break;
}
if (op)
free(op);
thr_exit(NULL);
return (NULL);
}
/*
* The door server thead which has the door client pid will be marked
* as to be clean up. If pid is 0, no marking and just clean up all.
*/
static void
cleanup_thread_by_pid(pid_t pid)
{
cleanup_op_t *op;
if ((op = malloc(sizeof (cleanup_op_t))) == NULL)
return;
op->pid = pid;
/* clean up all if pid is 0 */
if (pid == 0)
op->type = CLEANUP_ALL;
else
op->type = CLEANUP_BY_PID;
if (thr_create(NULL, 0, chg_cleanup_waiting_threads,
(void *)op, THR_BOUND|THR_DETACHED, NULL) != 0) {
free(op);
logit("thr_create failed for cleanup_thread_by_pid(%ld)\n",
pid);
}
}
/*
* Output a psinfo of an nscd process with process id pid
* Return: 0 - Can't find the process or it's not nscd
* 1 - psinfo found
* Note: If info is NULL, returns 0 or 1 only and no output from info.
*/
static int
get_nscd_psinfo(pid_t pid, psinfo_t *info)
{
psinfo_t pinfo;
char fname[MAXPATHLEN];
ssize_t ret;
int fd;
if (snprintf(fname, MAXPATHLEN, "/proc/%d/psinfo", pid) > 0) {
if ((fd = open(fname, O_RDONLY)) >= 0) {
ret = read(fd, &pinfo, sizeof (psinfo_t));
(void) close(fd);
if ((ret == sizeof (psinfo_t)) &&
(strcmp(pinfo.pr_fname, "nscd") == 0)) {
if (info)
*info = pinfo;
return (1);
}
}
}
return (0);
}
/*
* If the parent process is nscd and euid is 0, it's a peruser nscd.
*/
static int
is_peruser_nscd(pid_t pid)
{
pid_t ppid;
psinfo_t pinfo;
if (get_nscd_psinfo(pid, &pinfo)) {
ppid = pinfo.pr_ppid;
if (get_nscd_psinfo(ppid, &pinfo) && pinfo.pr_euid == 0)
/*
* get psinfo of parent forker nscd
*/
return (1);
else
return (0);
} else {
return (0);
}
}
/*
* Check if the door client making door call is a nscd or peruser nscd and
* output door client's pid.
*/
int
chg_is_called_from_nscd_or_peruser_nscd(char *dc_str, pid_t *pidp)
{
int rc;
uid_t euid;
pid_t pid;
ucred_t *uc = NULL;
if (door_ucred(&uc) != 0) {
rc = errno;
logit("door_ucred() call failed %s\n", strerror(rc));
return (0);
}
euid = ucred_geteuid(uc);
pid = *pidp = ucred_getpid(uc);
if ((euid == 0 && is_called_from_nscd(pid)) ||
is_peruser_nscd(pid)) {
if (current_admin.debug_level >= DBG_ALL)
logit("ldap_cachemgr received %s call from pid %ld, "
"uid %u, euid %u\n", dc_str, pid,
ucred_getruid(uc), euid);
rc = 1;
} else {
if (current_admin.debug_level >= DBG_CANT_FIND)
logit("%s call failed(cred): caller pid %ld, uid %u, "
"euid %u\n", dc_str, pid,
ucred_getruid(uc), euid);
rc = 0;
}
ucred_free(uc);
return (rc);
}