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2550 lines
68 KiB
C
2550 lines
68 KiB
C
/* Inner loops of cache daemon.
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Copyright (C) 1998-2024 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published
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by the Free Software Foundation; version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, see <https://www.gnu.org/licenses/>. */
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#include <alloca.h>
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#include <assert.h>
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#include <atomic.h>
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#include <error.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <grp.h>
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#include <ifaddrs.h>
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#include <libintl.h>
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#include <pthread.h>
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#include <pwd.h>
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#include <resolv.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <stdint.h>
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#include <arpa/inet.h>
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#ifdef HAVE_NETLINK
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# include <linux/netlink.h>
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# include <linux/rtnetlink.h>
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#endif
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#ifdef HAVE_EPOLL
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# include <sys/epoll.h>
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#endif
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#ifdef HAVE_INOTIFY
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# include <sys/inotify.h>
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#endif
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#include <sys/mman.h>
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#include <sys/param.h>
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#include <sys/poll.h>
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#include <sys/socket.h>
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#include <sys/stat.h>
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#include <sys/un.h>
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#include "nscd.h"
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#include "dbg_log.h"
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#include "selinux.h"
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#include <resolv/resolv.h>
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#include <kernel-features.h>
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#include <libc-diag.h>
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/* Support to run nscd as an unprivileged user */
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const char *server_user;
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static uid_t server_uid;
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static gid_t server_gid;
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const char *stat_user;
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uid_t stat_uid;
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static gid_t *server_groups;
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#ifndef NGROUPS
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# define NGROUPS 32
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#endif
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static int server_ngroups;
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static pthread_attr_t attr;
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static void begin_drop_privileges (void);
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static void finish_drop_privileges (void);
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/* Map request type to a string. */
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const char *const serv2str[LASTREQ] =
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{
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[GETPWBYNAME] = "GETPWBYNAME",
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[GETPWBYUID] = "GETPWBYUID",
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[GETGRBYNAME] = "GETGRBYNAME",
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[GETGRBYGID] = "GETGRBYGID",
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[GETHOSTBYNAME] = "GETHOSTBYNAME",
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[GETHOSTBYNAMEv6] = "GETHOSTBYNAMEv6",
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[GETHOSTBYADDR] = "GETHOSTBYADDR",
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[GETHOSTBYADDRv6] = "GETHOSTBYADDRv6",
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[SHUTDOWN] = "SHUTDOWN",
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[GETSTAT] = "GETSTAT",
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[INVALIDATE] = "INVALIDATE",
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[GETFDPW] = "GETFDPW",
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[GETFDGR] = "GETFDGR",
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[GETFDHST] = "GETFDHST",
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[GETAI] = "GETAI",
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[INITGROUPS] = "INITGROUPS",
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[GETSERVBYNAME] = "GETSERVBYNAME",
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[GETSERVBYPORT] = "GETSERVBYPORT",
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[GETFDSERV] = "GETFDSERV",
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[GETNETGRENT] = "GETNETGRENT",
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[INNETGR] = "INNETGR",
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[GETFDNETGR] = "GETFDNETGR"
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};
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#ifdef PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP
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# define RWLOCK_INITIALIZER PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP
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#else
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# define RWLOCK_INITIALIZER PTHREAD_RWLOCK_INITIALIZER
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#endif
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/* The control data structures for the services. */
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struct database_dyn dbs[lastdb] =
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{
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[pwddb] = {
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.lock = RWLOCK_INITIALIZER,
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.prune_lock = PTHREAD_MUTEX_INITIALIZER,
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.prune_run_lock = PTHREAD_MUTEX_INITIALIZER,
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.enabled = 0,
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.check_file = 1,
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.persistent = 0,
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.propagate = 1,
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.shared = 0,
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.max_db_size = DEFAULT_MAX_DB_SIZE,
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.suggested_module = DEFAULT_SUGGESTED_MODULE,
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.db_filename = _PATH_NSCD_PASSWD_DB,
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.disabled_iov = &pwd_iov_disabled,
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.postimeout = 3600,
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.negtimeout = 20,
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.wr_fd = -1,
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.ro_fd = -1,
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.mmap_used = false
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},
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[grpdb] = {
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.lock = RWLOCK_INITIALIZER,
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.prune_lock = PTHREAD_MUTEX_INITIALIZER,
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.prune_run_lock = PTHREAD_MUTEX_INITIALIZER,
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.enabled = 0,
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.check_file = 1,
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.persistent = 0,
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.propagate = 1,
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.shared = 0,
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.max_db_size = DEFAULT_MAX_DB_SIZE,
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.suggested_module = DEFAULT_SUGGESTED_MODULE,
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.db_filename = _PATH_NSCD_GROUP_DB,
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.disabled_iov = &grp_iov_disabled,
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.postimeout = 3600,
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.negtimeout = 60,
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.wr_fd = -1,
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.ro_fd = -1,
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.mmap_used = false
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},
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[hstdb] = {
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.lock = RWLOCK_INITIALIZER,
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.prune_lock = PTHREAD_MUTEX_INITIALIZER,
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.prune_run_lock = PTHREAD_MUTEX_INITIALIZER,
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.enabled = 0,
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.check_file = 1,
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.persistent = 0,
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.propagate = 0, /* Not used. */
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.shared = 0,
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.max_db_size = DEFAULT_MAX_DB_SIZE,
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.suggested_module = DEFAULT_SUGGESTED_MODULE,
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.db_filename = _PATH_NSCD_HOSTS_DB,
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.disabled_iov = &hst_iov_disabled,
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.postimeout = 3600,
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.negtimeout = 20,
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.wr_fd = -1,
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.ro_fd = -1,
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.mmap_used = false
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},
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[servdb] = {
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.lock = RWLOCK_INITIALIZER,
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.prune_lock = PTHREAD_MUTEX_INITIALIZER,
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.prune_run_lock = PTHREAD_MUTEX_INITIALIZER,
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.enabled = 0,
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.check_file = 1,
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.persistent = 0,
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.propagate = 0, /* Not used. */
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.shared = 0,
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.max_db_size = DEFAULT_MAX_DB_SIZE,
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.suggested_module = DEFAULT_SUGGESTED_MODULE,
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.db_filename = _PATH_NSCD_SERVICES_DB,
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.disabled_iov = &serv_iov_disabled,
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.postimeout = 28800,
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.negtimeout = 20,
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.wr_fd = -1,
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.ro_fd = -1,
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.mmap_used = false
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},
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[netgrdb] = {
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.lock = RWLOCK_INITIALIZER,
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.prune_lock = PTHREAD_MUTEX_INITIALIZER,
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.prune_run_lock = PTHREAD_MUTEX_INITIALIZER,
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.enabled = 0,
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.check_file = 1,
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.persistent = 0,
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.propagate = 0, /* Not used. */
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.shared = 0,
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.max_db_size = DEFAULT_MAX_DB_SIZE,
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.suggested_module = DEFAULT_SUGGESTED_MODULE,
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.db_filename = _PATH_NSCD_NETGROUP_DB,
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.disabled_iov = &netgroup_iov_disabled,
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.postimeout = 28800,
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.negtimeout = 20,
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.wr_fd = -1,
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.ro_fd = -1,
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.mmap_used = false
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}
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};
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/* Mapping of request type to database. */
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static struct
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{
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bool data_request;
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struct database_dyn *db;
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} const reqinfo[LASTREQ] =
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{
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[GETPWBYNAME] = { true, &dbs[pwddb] },
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[GETPWBYUID] = { true, &dbs[pwddb] },
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[GETGRBYNAME] = { true, &dbs[grpdb] },
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[GETGRBYGID] = { true, &dbs[grpdb] },
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[GETHOSTBYNAME] = { true, &dbs[hstdb] },
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[GETHOSTBYNAMEv6] = { true, &dbs[hstdb] },
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[GETHOSTBYADDR] = { true, &dbs[hstdb] },
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[GETHOSTBYADDRv6] = { true, &dbs[hstdb] },
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[SHUTDOWN] = { false, NULL },
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[GETSTAT] = { false, NULL },
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[GETFDPW] = { false, &dbs[pwddb] },
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[GETFDGR] = { false, &dbs[grpdb] },
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[GETFDHST] = { false, &dbs[hstdb] },
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[GETAI] = { true, &dbs[hstdb] },
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[INITGROUPS] = { true, &dbs[grpdb] },
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[GETSERVBYNAME] = { true, &dbs[servdb] },
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[GETSERVBYPORT] = { true, &dbs[servdb] },
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[GETFDSERV] = { false, &dbs[servdb] },
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[GETNETGRENT] = { true, &dbs[netgrdb] },
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[INNETGR] = { true, &dbs[netgrdb] },
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[GETFDNETGR] = { false, &dbs[netgrdb] }
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};
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/* Initial number of threads to use. */
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int nthreads = -1;
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/* Maximum number of threads to use. */
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int max_nthreads = 32;
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/* Socket for incoming connections. */
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static int sock;
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#ifdef HAVE_INOTIFY
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/* Inotify descriptor. */
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int inotify_fd = -1;
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#endif
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#ifdef HAVE_NETLINK
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/* Descriptor for netlink status updates. */
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static int nl_status_fd = -1;
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static uint32_t
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__bump_nl_timestamp (void)
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{
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static uint32_t nl_timestamp;
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if (atomic_fetch_add_relaxed (&nl_timestamp, 1) + 1 == 0)
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atomic_fetch_add_relaxed (&nl_timestamp, 1);
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return nl_timestamp;
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}
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#endif
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/* Number of times clients had to wait. */
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unsigned long int client_queued;
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ssize_t
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writeall (int fd, const void *buf, size_t len)
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{
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size_t n = len;
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ssize_t ret;
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do
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{
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ret = TEMP_FAILURE_RETRY (send (fd, buf, n, MSG_NOSIGNAL));
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if (ret <= 0)
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break;
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buf = (const char *) buf + ret;
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n -= ret;
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}
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while (n > 0);
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return ret < 0 ? ret : len - n;
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}
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enum usekey
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{
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use_not = 0,
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/* The following three are not really used, they are symbolic constants. */
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use_first = 16,
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use_begin = 32,
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use_end = 64,
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use_he = 1,
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use_he_begin = use_he | use_begin,
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use_he_end = use_he | use_end,
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use_data = 3,
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use_data_begin = use_data | use_begin,
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use_data_end = use_data | use_end,
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use_data_first = use_data_begin | use_first
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};
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static int
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check_use (const char *data, nscd_ssize_t first_free, uint8_t *usemap,
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enum usekey use, ref_t start, size_t len)
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{
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if (len < 2)
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return 0;
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if (start > first_free || start + len > first_free
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|| (start & BLOCK_ALIGN_M1))
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return 0;
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if (usemap[start] == use_not)
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{
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/* Add the start marker. */
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usemap[start] = use | use_begin;
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use &= ~use_first;
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while (--len > 0)
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if (usemap[++start] != use_not)
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return 0;
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else
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usemap[start] = use;
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/* Add the end marker. */
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usemap[start] = use | use_end;
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}
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else if ((usemap[start] & ~use_first) == ((use | use_begin) & ~use_first))
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{
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/* Hash entries can't be shared. */
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if (use == use_he)
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return 0;
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usemap[start] |= (use & use_first);
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use &= ~use_first;
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while (--len > 1)
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if (usemap[++start] != use)
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return 0;
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if (usemap[++start] != (use | use_end))
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return 0;
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}
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else
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/* Points to a wrong object or somewhere in the middle. */
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return 0;
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return 1;
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}
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/* Verify data in persistent database. */
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static int
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verify_persistent_db (void *mem, struct database_pers_head *readhead, int dbnr)
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{
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assert (dbnr == pwddb || dbnr == grpdb || dbnr == hstdb || dbnr == servdb
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|| dbnr == netgrdb);
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time_t now = time (NULL);
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struct database_pers_head *head = mem;
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struct database_pers_head head_copy = *head;
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/* Check that the header that was read matches the head in the database. */
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if (memcmp (head, readhead, sizeof (*head)) != 0)
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return 0;
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/* First some easy tests: make sure the database header is sane. */
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if (head->version != DB_VERSION
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|| head->header_size != sizeof (*head)
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/* We allow a timestamp to be one hour ahead of the current time.
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This should cover daylight saving time changes. */
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|| head->timestamp > now + 60 * 60 + 60
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|| (head->gc_cycle & 1)
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|| head->module == 0
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|| (size_t) head->module > INT32_MAX / sizeof (ref_t)
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|| (size_t) head->data_size > INT32_MAX - head->module * sizeof (ref_t)
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|| head->first_free < 0
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|| head->first_free > head->data_size
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|| (head->first_free & BLOCK_ALIGN_M1) != 0
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|| head->maxnentries < 0
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|| head->maxnsearched < 0)
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return 0;
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uint8_t *usemap = calloc (head->first_free, 1);
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if (usemap == NULL)
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return 0;
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const char *data = (char *) &head->array[roundup (head->module,
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ALIGN / sizeof (ref_t))];
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nscd_ssize_t he_cnt = 0;
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for (nscd_ssize_t cnt = 0; cnt < head->module; ++cnt)
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{
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ref_t trail = head->array[cnt];
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ref_t work = trail;
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int tick = 0;
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while (work != ENDREF)
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{
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if (! check_use (data, head->first_free, usemap, use_he, work,
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sizeof (struct hashentry)))
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goto fail;
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/* Now we know we can dereference the record. */
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struct hashentry *here = (struct hashentry *) (data + work);
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++he_cnt;
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/* Make sure the record is for this type of service. */
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if (here->type >= LASTREQ
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|| reqinfo[here->type].db != &dbs[dbnr])
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goto fail;
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|
|
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/* Validate boolean field value. */
|
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if (here->first != false && here->first != true)
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goto fail;
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|
|
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if (here->len < 0)
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goto fail;
|
|
|
|
/* Now the data. */
|
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if (here->packet < 0
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|| here->packet > head->first_free
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|| here->packet + sizeof (struct datahead) > head->first_free)
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goto fail;
|
|
|
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struct datahead *dh = (struct datahead *) (data + here->packet);
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|
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if (! check_use (data, head->first_free, usemap,
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use_data | (here->first ? use_first : 0),
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here->packet, dh->allocsize))
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goto fail;
|
|
|
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if (dh->allocsize < sizeof (struct datahead)
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|| dh->recsize > dh->allocsize
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|| (dh->notfound != false && dh->notfound != true)
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|| (dh->usable != false && dh->usable != true))
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goto fail;
|
|
|
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if (here->key < here->packet + sizeof (struct datahead)
|
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|| here->key > here->packet + dh->allocsize
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|| here->key + here->len > here->packet + dh->allocsize)
|
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goto fail;
|
|
|
|
work = here->next;
|
|
|
|
if (work == trail)
|
|
/* A circular list, this must not happen. */
|
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goto fail;
|
|
if (tick)
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trail = ((struct hashentry *) (data + trail))->next;
|
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tick = 1 - tick;
|
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}
|
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}
|
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|
|
if (he_cnt != head->nentries)
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goto fail;
|
|
|
|
/* See if all data and keys had at least one reference from
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he->first == true hashentry. */
|
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for (ref_t idx = 0; idx < head->first_free; ++idx)
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{
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if (usemap[idx] == use_data_begin)
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goto fail;
|
|
}
|
|
|
|
/* Finally, make sure the database hasn't changed since the first test. */
|
|
if (memcmp (mem, &head_copy, sizeof (*head)) != 0)
|
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goto fail;
|
|
|
|
free (usemap);
|
|
return 1;
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|
|
fail:
|
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free (usemap);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Initialize database information structures. */
|
|
void
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|
nscd_init (void)
|
|
{
|
|
/* Look up unprivileged uid/gid/groups before we start listening on the
|
|
socket */
|
|
if (server_user != NULL)
|
|
begin_drop_privileges ();
|
|
|
|
if (nthreads == -1)
|
|
/* No configuration for this value, assume a default. */
|
|
nthreads = 4;
|
|
|
|
for (size_t cnt = 0; cnt < lastdb; ++cnt)
|
|
if (dbs[cnt].enabled)
|
|
{
|
|
pthread_rwlock_init (&dbs[cnt].lock, NULL);
|
|
pthread_mutex_init (&dbs[cnt].memlock, NULL);
|
|
|
|
if (dbs[cnt].persistent)
|
|
{
|
|
/* Try to open the appropriate file on disk. */
|
|
int fd = open (dbs[cnt].db_filename, O_RDWR | O_CLOEXEC);
|
|
if (fd != -1)
|
|
{
|
|
char *msg = NULL;
|
|
struct stat64 st;
|
|
void *mem;
|
|
size_t total;
|
|
struct database_pers_head head;
|
|
ssize_t n = TEMP_FAILURE_RETRY (read (fd, &head,
|
|
sizeof (head)));
|
|
if (n != sizeof (head) || fstat64 (fd, &st) != 0)
|
|
{
|
|
fail_db_errno:
|
|
/* The code is single-threaded at this point so
|
|
using strerror is just fine. */
|
|
msg = strerror (errno);
|
|
fail_db:
|
|
dbg_log (_("invalid persistent database file \"%s\": %s"),
|
|
dbs[cnt].db_filename, msg);
|
|
unlink (dbs[cnt].db_filename);
|
|
}
|
|
else if (head.module == 0 && head.data_size == 0)
|
|
{
|
|
/* The file has been created, but the head has not
|
|
been initialized yet. */
|
|
msg = _("uninitialized header");
|
|
goto fail_db;
|
|
}
|
|
else if (head.header_size != (int) sizeof (head))
|
|
{
|
|
msg = _("header size does not match");
|
|
goto fail_db;
|
|
}
|
|
else if ((total = (sizeof (head)
|
|
+ roundup (head.module * sizeof (ref_t),
|
|
ALIGN)
|
|
+ head.data_size))
|
|
> st.st_size
|
|
|| total < sizeof (head))
|
|
{
|
|
msg = _("file size does not match");
|
|
goto fail_db;
|
|
}
|
|
/* Note we map with the maximum size allowed for the
|
|
database. This is likely much larger than the
|
|
actual file size. This is OK on most OSes since
|
|
extensions of the underlying file will
|
|
automatically translate more pages available for
|
|
memory access. */
|
|
else if ((mem = mmap (NULL, dbs[cnt].max_db_size,
|
|
PROT_READ | PROT_WRITE,
|
|
MAP_SHARED, fd, 0))
|
|
== MAP_FAILED)
|
|
goto fail_db_errno;
|
|
else if (!verify_persistent_db (mem, &head, cnt))
|
|
{
|
|
munmap (mem, total);
|
|
msg = _("verification failed");
|
|
goto fail_db;
|
|
}
|
|
else
|
|
{
|
|
/* Success. We have the database. */
|
|
dbs[cnt].head = mem;
|
|
dbs[cnt].memsize = total;
|
|
dbs[cnt].data = (char *)
|
|
&dbs[cnt].head->array[roundup (dbs[cnt].head->module,
|
|
ALIGN / sizeof (ref_t))];
|
|
dbs[cnt].mmap_used = true;
|
|
|
|
if (dbs[cnt].suggested_module > head.module)
|
|
dbg_log (_("suggested size of table for database %s larger than the persistent database's table"),
|
|
dbnames[cnt]);
|
|
|
|
dbs[cnt].wr_fd = fd;
|
|
fd = -1;
|
|
/* We also need a read-only descriptor. */
|
|
if (dbs[cnt].shared)
|
|
{
|
|
dbs[cnt].ro_fd = open (dbs[cnt].db_filename,
|
|
O_RDONLY | O_CLOEXEC);
|
|
if (dbs[cnt].ro_fd == -1)
|
|
dbg_log (_("\
|
|
cannot create read-only descriptor for \"%s\"; no mmap"),
|
|
dbs[cnt].db_filename);
|
|
}
|
|
|
|
// XXX Shall we test whether the descriptors actually
|
|
// XXX point to the same file?
|
|
}
|
|
|
|
/* Close the file descriptors in case something went
|
|
wrong in which case the variable have not been
|
|
assigned -1. */
|
|
if (fd != -1)
|
|
close (fd);
|
|
}
|
|
else if (errno == EACCES)
|
|
do_exit (EXIT_FAILURE, 0, _("cannot access '%s'"),
|
|
dbs[cnt].db_filename);
|
|
}
|
|
|
|
if (dbs[cnt].head == NULL)
|
|
{
|
|
/* No database loaded. Allocate the data structure,
|
|
possibly on disk. */
|
|
struct database_pers_head head;
|
|
size_t total = (sizeof (head)
|
|
+ roundup (dbs[cnt].suggested_module
|
|
* sizeof (ref_t), ALIGN)
|
|
+ (dbs[cnt].suggested_module
|
|
* DEFAULT_DATASIZE_PER_BUCKET));
|
|
|
|
/* Try to create the database. If we do not need a
|
|
persistent database create a temporary file. */
|
|
int fd;
|
|
int ro_fd = -1;
|
|
if (dbs[cnt].persistent)
|
|
{
|
|
fd = open (dbs[cnt].db_filename,
|
|
O_RDWR | O_CREAT | O_EXCL | O_TRUNC | O_CLOEXEC,
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd != -1 && dbs[cnt].shared)
|
|
ro_fd = open (dbs[cnt].db_filename,
|
|
O_RDONLY | O_CLOEXEC);
|
|
}
|
|
else
|
|
{
|
|
char fname[] = _PATH_NSCD_XYZ_DB_TMP;
|
|
fd = mkostemp (fname, O_CLOEXEC);
|
|
|
|
/* We do not need the file name anymore after we
|
|
opened another file descriptor in read-only mode. */
|
|
if (fd != -1)
|
|
{
|
|
if (dbs[cnt].shared)
|
|
ro_fd = open (fname, O_RDONLY | O_CLOEXEC);
|
|
|
|
unlink (fname);
|
|
}
|
|
}
|
|
|
|
if (fd == -1)
|
|
{
|
|
if (errno == EEXIST)
|
|
{
|
|
dbg_log (_("database for %s corrupted or simultaneously used; remove %s manually if necessary and restart"),
|
|
dbnames[cnt], dbs[cnt].db_filename);
|
|
do_exit (1, 0, NULL);
|
|
}
|
|
|
|
if (dbs[cnt].persistent)
|
|
dbg_log (_("cannot create %s; no persistent database used"),
|
|
dbs[cnt].db_filename);
|
|
else
|
|
dbg_log (_("cannot create %s; no sharing possible"),
|
|
dbs[cnt].db_filename);
|
|
|
|
dbs[cnt].persistent = 0;
|
|
// XXX remember: no mmap
|
|
}
|
|
else
|
|
{
|
|
/* Tell the user if we could not create the read-only
|
|
descriptor. */
|
|
if (ro_fd == -1 && dbs[cnt].shared)
|
|
dbg_log (_("\
|
|
cannot create read-only descriptor for \"%s\"; no mmap"),
|
|
dbs[cnt].db_filename);
|
|
|
|
/* Before we create the header, initialize the hash
|
|
table. That way if we get interrupted while writing
|
|
the header we can recognize a partially initialized
|
|
database. */
|
|
size_t ps = sysconf (_SC_PAGESIZE);
|
|
char tmpbuf[ps];
|
|
assert (~ENDREF == 0);
|
|
memset (tmpbuf, '\xff', ps);
|
|
|
|
size_t remaining = dbs[cnt].suggested_module * sizeof (ref_t);
|
|
off_t offset = sizeof (head);
|
|
|
|
size_t towrite;
|
|
if (offset % ps != 0)
|
|
{
|
|
towrite = MIN (remaining, ps - (offset % ps));
|
|
if (pwrite (fd, tmpbuf, towrite, offset) != towrite)
|
|
goto write_fail;
|
|
offset += towrite;
|
|
remaining -= towrite;
|
|
}
|
|
|
|
while (remaining > ps)
|
|
{
|
|
if (pwrite (fd, tmpbuf, ps, offset) == -1)
|
|
goto write_fail;
|
|
offset += ps;
|
|
remaining -= ps;
|
|
}
|
|
|
|
if (remaining > 0
|
|
&& pwrite (fd, tmpbuf, remaining, offset) != remaining)
|
|
goto write_fail;
|
|
|
|
/* Create the header of the file. */
|
|
struct database_pers_head head =
|
|
{
|
|
.version = DB_VERSION,
|
|
.header_size = sizeof (head),
|
|
.module = dbs[cnt].suggested_module,
|
|
.data_size = (dbs[cnt].suggested_module
|
|
* DEFAULT_DATASIZE_PER_BUCKET),
|
|
.first_free = 0
|
|
};
|
|
void *mem;
|
|
|
|
if ((TEMP_FAILURE_RETRY (write (fd, &head, sizeof (head)))
|
|
!= sizeof (head))
|
|
|| (TEMP_FAILURE_RETRY_VAL (posix_fallocate (fd, 0, total))
|
|
!= 0)
|
|
|| (mem = mmap (NULL, dbs[cnt].max_db_size,
|
|
PROT_READ | PROT_WRITE,
|
|
MAP_SHARED, fd, 0)) == MAP_FAILED)
|
|
{
|
|
write_fail:
|
|
unlink (dbs[cnt].db_filename);
|
|
dbg_log (_("cannot write to database file %s: %s"),
|
|
dbs[cnt].db_filename, strerror (errno));
|
|
dbs[cnt].persistent = 0;
|
|
}
|
|
else
|
|
{
|
|
/* Success. */
|
|
dbs[cnt].head = mem;
|
|
dbs[cnt].data = (char *)
|
|
&dbs[cnt].head->array[roundup (dbs[cnt].head->module,
|
|
ALIGN / sizeof (ref_t))];
|
|
dbs[cnt].memsize = total;
|
|
dbs[cnt].mmap_used = true;
|
|
|
|
/* Remember the descriptors. */
|
|
dbs[cnt].wr_fd = fd;
|
|
dbs[cnt].ro_fd = ro_fd;
|
|
fd = -1;
|
|
ro_fd = -1;
|
|
}
|
|
|
|
if (fd != -1)
|
|
close (fd);
|
|
if (ro_fd != -1)
|
|
close (ro_fd);
|
|
}
|
|
}
|
|
|
|
if (dbs[cnt].head == NULL)
|
|
{
|
|
/* We do not use the persistent database. Just
|
|
create an in-memory data structure. */
|
|
assert (! dbs[cnt].persistent);
|
|
|
|
dbs[cnt].head = xmalloc (sizeof (struct database_pers_head)
|
|
+ (dbs[cnt].suggested_module
|
|
* sizeof (ref_t)));
|
|
memset (dbs[cnt].head, '\0', sizeof (struct database_pers_head));
|
|
assert (~ENDREF == 0);
|
|
memset (dbs[cnt].head->array, '\xff',
|
|
dbs[cnt].suggested_module * sizeof (ref_t));
|
|
dbs[cnt].head->module = dbs[cnt].suggested_module;
|
|
dbs[cnt].head->data_size = (DEFAULT_DATASIZE_PER_BUCKET
|
|
* dbs[cnt].head->module);
|
|
dbs[cnt].data = xmalloc (dbs[cnt].head->data_size);
|
|
dbs[cnt].head->first_free = 0;
|
|
|
|
dbs[cnt].shared = 0;
|
|
assert (dbs[cnt].ro_fd == -1);
|
|
}
|
|
}
|
|
|
|
/* Create the socket. */
|
|
sock = socket (AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
|
|
if (sock < 0)
|
|
{
|
|
dbg_log (_("cannot open socket: %s"), strerror (errno));
|
|
do_exit (errno == EACCES ? 4 : 1, 0, NULL);
|
|
}
|
|
/* Bind a name to the socket. */
|
|
struct sockaddr_un sock_addr;
|
|
sock_addr.sun_family = AF_UNIX;
|
|
strcpy (sock_addr.sun_path, _PATH_NSCDSOCKET);
|
|
if (bind (sock, (struct sockaddr *) &sock_addr, sizeof (sock_addr)) < 0)
|
|
{
|
|
dbg_log ("%s: %s", _PATH_NSCDSOCKET, strerror (errno));
|
|
do_exit (errno == EACCES ? 4 : 1, 0, NULL);
|
|
}
|
|
|
|
/* Set permissions for the socket. */
|
|
chmod (_PATH_NSCDSOCKET, DEFFILEMODE);
|
|
|
|
/* Set the socket up to accept connections. */
|
|
if (listen (sock, SOMAXCONN) < 0)
|
|
{
|
|
dbg_log (_("cannot enable socket to accept connections: %s"),
|
|
strerror (errno));
|
|
do_exit (1, 0, NULL);
|
|
}
|
|
|
|
#ifdef HAVE_NETLINK
|
|
if (dbs[hstdb].enabled)
|
|
{
|
|
/* Try to open netlink socket to monitor network setting changes. */
|
|
nl_status_fd = socket (AF_NETLINK,
|
|
SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK,
|
|
NETLINK_ROUTE);
|
|
if (nl_status_fd != -1)
|
|
{
|
|
struct sockaddr_nl snl;
|
|
memset (&snl, '\0', sizeof (snl));
|
|
snl.nl_family = AF_NETLINK;
|
|
/* XXX Is this the best set to use? */
|
|
snl.nl_groups = (RTMGRP_IPV4_IFADDR | RTMGRP_TC | RTMGRP_IPV4_MROUTE
|
|
| RTMGRP_IPV4_ROUTE | RTMGRP_IPV4_RULE
|
|
| RTMGRP_IPV6_IFADDR | RTMGRP_IPV6_MROUTE
|
|
| RTMGRP_IPV6_ROUTE | RTMGRP_IPV6_IFINFO
|
|
| RTMGRP_IPV6_PREFIX);
|
|
|
|
if (bind (nl_status_fd, (struct sockaddr *) &snl, sizeof (snl)) != 0)
|
|
{
|
|
close (nl_status_fd);
|
|
nl_status_fd = -1;
|
|
}
|
|
else
|
|
{
|
|
/* Start the timestamp process. */
|
|
dbs[hstdb].head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP]
|
|
= __bump_nl_timestamp ();
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Change to unprivileged uid/gid/groups if specified in config file */
|
|
if (server_user != NULL)
|
|
finish_drop_privileges ();
|
|
}
|
|
|
|
#ifdef HAVE_INOTIFY
|
|
#define TRACED_FILE_MASK (IN_DELETE_SELF | IN_CLOSE_WRITE | IN_MOVE_SELF)
|
|
#define TRACED_DIR_MASK (IN_DELETE_SELF | IN_CREATE | IN_MOVED_TO | IN_MOVE_SELF)
|
|
void
|
|
install_watches (struct traced_file *finfo)
|
|
{
|
|
/* Use inotify support if we have it. */
|
|
if (finfo->inotify_descr[TRACED_FILE] < 0)
|
|
finfo->inotify_descr[TRACED_FILE] = inotify_add_watch (inotify_fd,
|
|
finfo->fname,
|
|
TRACED_FILE_MASK);
|
|
if (finfo->inotify_descr[TRACED_FILE] < 0)
|
|
{
|
|
dbg_log (_("disabled inotify-based monitoring for file `%s': %s"),
|
|
finfo->fname, strerror (errno));
|
|
return;
|
|
}
|
|
dbg_log (_("monitoring file `%s` (%d)"),
|
|
finfo->fname, finfo->inotify_descr[TRACED_FILE]);
|
|
/* Additionally listen for events in the file's parent directory.
|
|
We do this because the file to be watched might be
|
|
deleted and then added back again. When it is added back again
|
|
we must re-add the watch. We must also cover IN_MOVED_TO to
|
|
detect a file being moved into the directory. */
|
|
if (finfo->inotify_descr[TRACED_DIR] < 0)
|
|
finfo->inotify_descr[TRACED_DIR] = inotify_add_watch (inotify_fd,
|
|
finfo->dname,
|
|
TRACED_DIR_MASK);
|
|
if (finfo->inotify_descr[TRACED_DIR] < 0)
|
|
{
|
|
dbg_log (_("disabled inotify-based monitoring for directory `%s': %s"),
|
|
finfo->fname, strerror (errno));
|
|
return;
|
|
}
|
|
dbg_log (_("monitoring directory `%s` (%d)"),
|
|
finfo->dname, finfo->inotify_descr[TRACED_DIR]);
|
|
}
|
|
#endif
|
|
|
|
/* Register the file in FINFO as a traced file for the database DBS[DBIX].
|
|
|
|
We support registering multiple files per database. Each call to
|
|
register_traced_file adds to the list of registered files.
|
|
|
|
When we prune the database, either through timeout or a request to
|
|
invalidate, we will check to see if any of the registered files has changed.
|
|
When we accept new connections to handle a cache request we will also
|
|
check to see if any of the registered files has changed.
|
|
|
|
If we have inotify support then we install an inotify fd to notify us of
|
|
file deletion or modification, both of which will require we invalidate
|
|
the cache for the database. Without inotify support we stat the file and
|
|
store st_mtime to determine if the file has been modified. */
|
|
void
|
|
register_traced_file (size_t dbidx, struct traced_file *finfo)
|
|
{
|
|
/* If the database is disabled or file checking is disabled
|
|
then ignore the registration. */
|
|
if (! dbs[dbidx].enabled || ! dbs[dbidx].check_file)
|
|
return;
|
|
|
|
if (__glibc_unlikely (debug_level > 0))
|
|
dbg_log (_("monitoring file %s for database %s"),
|
|
finfo->fname, dbnames[dbidx]);
|
|
|
|
#ifdef HAVE_INOTIFY
|
|
install_watches (finfo);
|
|
#endif
|
|
struct stat64 st;
|
|
if (stat64 (finfo->fname, &st) < 0)
|
|
{
|
|
/* We cannot stat() the file. Set mtime to zero and try again later. */
|
|
dbg_log (_("stat failed for file `%s'; will try again later: %s"),
|
|
finfo->fname, strerror (errno));
|
|
finfo->mtime = 0;
|
|
}
|
|
else
|
|
finfo->mtime = st.st_mtime;
|
|
|
|
/* Queue up the file name. */
|
|
finfo->next = dbs[dbidx].traced_files;
|
|
dbs[dbidx].traced_files = finfo;
|
|
}
|
|
|
|
|
|
/* Close the connections. */
|
|
void
|
|
close_sockets (void)
|
|
{
|
|
close (sock);
|
|
}
|
|
|
|
|
|
static void
|
|
invalidate_cache (char *key, int fd)
|
|
{
|
|
dbtype number;
|
|
int32_t resp;
|
|
|
|
for (number = pwddb; number < lastdb; ++number)
|
|
if (strcmp (key, dbnames[number]) == 0)
|
|
{
|
|
struct traced_file *runp = dbs[number].traced_files;
|
|
while (runp != NULL)
|
|
{
|
|
/* Make sure we reload from file when checking mtime. */
|
|
runp->mtime = 0;
|
|
#ifdef HAVE_INOTIFY
|
|
/* During an invalidation we try to reload the traced
|
|
file watches. This allows the user to re-sync if
|
|
inotify events were lost. Similar to what we do during
|
|
pruning. */
|
|
install_watches (runp);
|
|
#endif
|
|
if (runp->call_res_init)
|
|
{
|
|
res_init ();
|
|
break;
|
|
}
|
|
runp = runp->next;
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (number == lastdb)
|
|
{
|
|
resp = EINVAL;
|
|
writeall (fd, &resp, sizeof (resp));
|
|
return;
|
|
}
|
|
|
|
if (dbs[number].enabled)
|
|
{
|
|
pthread_mutex_lock (&dbs[number].prune_run_lock);
|
|
prune_cache (&dbs[number], LONG_MAX, fd);
|
|
pthread_mutex_unlock (&dbs[number].prune_run_lock);
|
|
}
|
|
else
|
|
{
|
|
resp = 0;
|
|
writeall (fd, &resp, sizeof (resp));
|
|
}
|
|
}
|
|
|
|
|
|
#ifdef SCM_RIGHTS
|
|
static void
|
|
send_ro_fd (struct database_dyn *db, char *key, int fd)
|
|
{
|
|
/* If we do not have an read-only file descriptor do nothing. */
|
|
if (db->ro_fd == -1)
|
|
return;
|
|
|
|
/* We need to send some data along with the descriptor. */
|
|
uint64_t mapsize = (db->head->data_size
|
|
+ roundup (db->head->module * sizeof (ref_t), ALIGN)
|
|
+ sizeof (struct database_pers_head));
|
|
struct iovec iov[2];
|
|
iov[0].iov_base = key;
|
|
iov[0].iov_len = strlen (key) + 1;
|
|
iov[1].iov_base = &mapsize;
|
|
iov[1].iov_len = sizeof (mapsize);
|
|
|
|
/* Prepare the control message to transfer the descriptor. */
|
|
union
|
|
{
|
|
struct cmsghdr hdr;
|
|
char bytes[CMSG_SPACE (sizeof (int))];
|
|
} buf;
|
|
struct msghdr msg = { .msg_iov = iov, .msg_iovlen = 2,
|
|
.msg_control = buf.bytes,
|
|
.msg_controllen = sizeof (buf) };
|
|
struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg);
|
|
|
|
cmsg->cmsg_level = SOL_SOCKET;
|
|
cmsg->cmsg_type = SCM_RIGHTS;
|
|
cmsg->cmsg_len = CMSG_LEN (sizeof (int));
|
|
|
|
int *ip = (int *) CMSG_DATA (cmsg);
|
|
*ip = db->ro_fd;
|
|
|
|
msg.msg_controllen = cmsg->cmsg_len;
|
|
|
|
/* Send the control message. We repeat when we are interrupted but
|
|
everything else is ignored. */
|
|
#ifndef MSG_NOSIGNAL
|
|
# define MSG_NOSIGNAL 0
|
|
#endif
|
|
(void) TEMP_FAILURE_RETRY (sendmsg (fd, &msg, MSG_NOSIGNAL));
|
|
|
|
if (__glibc_unlikely (debug_level > 0))
|
|
dbg_log (_("provide access to FD %d, for %s"), db->ro_fd, key);
|
|
}
|
|
#endif /* SCM_RIGHTS */
|
|
|
|
|
|
/* Handle new request. */
|
|
static void
|
|
handle_request (int fd, request_header *req, void *key, uid_t uid, pid_t pid)
|
|
{
|
|
if (__builtin_expect (req->version, NSCD_VERSION) != NSCD_VERSION)
|
|
{
|
|
if (debug_level > 0)
|
|
dbg_log (_("\
|
|
cannot handle old request version %d; current version is %d"),
|
|
req->version, NSCD_VERSION);
|
|
return;
|
|
}
|
|
|
|
/* Perform the SELinux check before we go on to the standard checks. */
|
|
if (selinux_enabled && nscd_request_avc_has_perm (fd, req->type) != 0)
|
|
{
|
|
if (debug_level > 0)
|
|
{
|
|
#ifdef SO_PEERCRED
|
|
char pbuf[sizeof ("/proc//exe") + 3 * sizeof (long int)];
|
|
# ifdef PATH_MAX
|
|
char buf[PATH_MAX];
|
|
# else
|
|
char buf[4096];
|
|
# endif
|
|
|
|
snprintf (pbuf, sizeof (pbuf), "/proc/%ld/exe", (long int) pid);
|
|
ssize_t n = readlink (pbuf, buf, sizeof (buf) - 1);
|
|
|
|
if (n <= 0)
|
|
dbg_log (_("\
|
|
request from %ld not handled due to missing permission"), (long int) pid);
|
|
else
|
|
{
|
|
buf[n] = '\0';
|
|
dbg_log (_("\
|
|
request from '%s' [%ld] not handled due to missing permission"),
|
|
buf, (long int) pid);
|
|
}
|
|
#else
|
|
dbg_log (_("request not handled due to missing permission"));
|
|
#endif
|
|
}
|
|
return;
|
|
}
|
|
|
|
struct database_dyn *db = reqinfo[req->type].db;
|
|
|
|
/* See whether we can service the request from the cache. */
|
|
if (__builtin_expect (reqinfo[req->type].data_request, true))
|
|
{
|
|
if (__builtin_expect (debug_level, 0) > 0)
|
|
{
|
|
if (req->type == GETHOSTBYADDR || req->type == GETHOSTBYADDRv6)
|
|
{
|
|
char buf[INET6_ADDRSTRLEN];
|
|
|
|
dbg_log ("\t%s (%s)", serv2str[req->type],
|
|
inet_ntop (req->type == GETHOSTBYADDR
|
|
? AF_INET : AF_INET6,
|
|
key, buf, sizeof (buf)));
|
|
}
|
|
else
|
|
dbg_log ("\t%s (%s)", serv2str[req->type], (char *) key);
|
|
}
|
|
|
|
/* Is this service enabled? */
|
|
if (__glibc_unlikely (!db->enabled))
|
|
{
|
|
/* No, sent the prepared record. */
|
|
if (TEMP_FAILURE_RETRY (send (fd, db->disabled_iov->iov_base,
|
|
db->disabled_iov->iov_len,
|
|
MSG_NOSIGNAL))
|
|
!= (ssize_t) db->disabled_iov->iov_len
|
|
&& __builtin_expect (debug_level, 0) > 0)
|
|
{
|
|
/* We have problems sending the result. */
|
|
char buf[256];
|
|
dbg_log (_("cannot write result: %s"),
|
|
strerror_r (errno, buf, sizeof (buf)));
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/* Be sure we can read the data. */
|
|
if (__glibc_unlikely (pthread_rwlock_tryrdlock (&db->lock) != 0))
|
|
{
|
|
++db->head->rdlockdelayed;
|
|
pthread_rwlock_rdlock (&db->lock);
|
|
}
|
|
|
|
/* See whether we can handle it from the cache. */
|
|
struct datahead *cached;
|
|
cached = (struct datahead *) cache_search (req->type, key, req->key_len,
|
|
db, uid);
|
|
if (cached != NULL)
|
|
{
|
|
/* Hurray it's in the cache. */
|
|
if (writeall (fd, cached->data, cached->recsize) != cached->recsize
|
|
&& __glibc_unlikely (debug_level > 0))
|
|
{
|
|
/* We have problems sending the result. */
|
|
char buf[256];
|
|
dbg_log (_("cannot write result: %s"),
|
|
strerror_r (errno, buf, sizeof (buf)));
|
|
}
|
|
|
|
pthread_rwlock_unlock (&db->lock);
|
|
|
|
return;
|
|
}
|
|
|
|
pthread_rwlock_unlock (&db->lock);
|
|
}
|
|
else if (__builtin_expect (debug_level, 0) > 0)
|
|
{
|
|
if (req->type == INVALIDATE)
|
|
dbg_log ("\t%s (%s)", serv2str[req->type], (char *) key);
|
|
else
|
|
dbg_log ("\t%s", serv2str[req->type]);
|
|
}
|
|
|
|
/* Handle the request. */
|
|
switch (req->type)
|
|
{
|
|
case GETPWBYNAME:
|
|
addpwbyname (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETPWBYUID:
|
|
addpwbyuid (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETGRBYNAME:
|
|
addgrbyname (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETGRBYGID:
|
|
addgrbygid (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETHOSTBYNAME:
|
|
addhstbyname (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETHOSTBYNAMEv6:
|
|
addhstbynamev6 (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETHOSTBYADDR:
|
|
addhstbyaddr (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETHOSTBYADDRv6:
|
|
addhstbyaddrv6 (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETAI:
|
|
addhstai (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case INITGROUPS:
|
|
addinitgroups (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETSERVBYNAME:
|
|
addservbyname (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETSERVBYPORT:
|
|
addservbyport (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETNETGRENT:
|
|
addgetnetgrent (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case INNETGR:
|
|
addinnetgr (db, fd, req, key, uid);
|
|
break;
|
|
|
|
case GETSTAT:
|
|
case SHUTDOWN:
|
|
case INVALIDATE:
|
|
{
|
|
/* Get the callers credentials. */
|
|
#ifdef SO_PEERCRED
|
|
struct ucred caller;
|
|
socklen_t optlen = sizeof (caller);
|
|
|
|
if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, &caller, &optlen) < 0)
|
|
{
|
|
char buf[256];
|
|
|
|
dbg_log (_("error getting caller's id: %s"),
|
|
strerror_r (errno, buf, sizeof (buf)));
|
|
break;
|
|
}
|
|
|
|
uid = caller.uid;
|
|
#else
|
|
/* Some systems have no SO_PEERCRED implementation. They don't
|
|
care about security so we don't as well. */
|
|
uid = 0;
|
|
#endif
|
|
}
|
|
|
|
/* Accept shutdown, getstat and invalidate only from root. For
|
|
the stat call also allow the user specified in the config file. */
|
|
if (req->type == GETSTAT)
|
|
{
|
|
if (uid == 0 || uid == stat_uid)
|
|
send_stats (fd, dbs);
|
|
}
|
|
else if (uid == 0)
|
|
{
|
|
if (req->type == INVALIDATE)
|
|
invalidate_cache (key, fd);
|
|
else
|
|
termination_handler (0);
|
|
}
|
|
break;
|
|
|
|
case GETFDPW:
|
|
case GETFDGR:
|
|
case GETFDHST:
|
|
case GETFDSERV:
|
|
case GETFDNETGR:
|
|
#ifdef SCM_RIGHTS
|
|
send_ro_fd (reqinfo[req->type].db, key, fd);
|
|
#endif
|
|
break;
|
|
|
|
default:
|
|
/* Ignore the command, it's nothing we know. */
|
|
break;
|
|
}
|
|
}
|
|
|
|
static char *
|
|
read_cmdline (size_t *size)
|
|
{
|
|
int fd = open ("/proc/self/cmdline", O_RDONLY);
|
|
if (fd < 0)
|
|
return NULL;
|
|
size_t current = 0;
|
|
size_t limit = 1024;
|
|
char *buffer = malloc (limit);
|
|
if (buffer == NULL)
|
|
{
|
|
close (fd);
|
|
errno = ENOMEM;
|
|
return NULL;
|
|
}
|
|
while (1)
|
|
{
|
|
if (current == limit)
|
|
{
|
|
char *newptr;
|
|
if (2 * limit < limit
|
|
|| (newptr = realloc (buffer, 2 * limit)) == NULL)
|
|
{
|
|
free (buffer);
|
|
close (fd);
|
|
errno = ENOMEM;
|
|
return NULL;
|
|
}
|
|
buffer = newptr;
|
|
limit *= 2;
|
|
}
|
|
|
|
ssize_t n = TEMP_FAILURE_RETRY (read (fd, buffer + current,
|
|
limit - current));
|
|
if (n == -1)
|
|
{
|
|
int e = errno;
|
|
free (buffer);
|
|
close (fd);
|
|
errno = e;
|
|
return NULL;
|
|
}
|
|
if (n == 0)
|
|
break;
|
|
current += n;
|
|
}
|
|
|
|
close (fd);
|
|
*size = current;
|
|
return buffer;
|
|
}
|
|
|
|
|
|
/* Restart the process. */
|
|
static void
|
|
restart (void)
|
|
{
|
|
/* First determine the parameters. We do not use the parameters
|
|
passed to main because then nscd would use the system libc after
|
|
restarting even if it was started by a non-system dynamic linker
|
|
during glibc testing. */
|
|
size_t readlen;
|
|
char *cmdline = read_cmdline (&readlen);
|
|
if (cmdline == NULL)
|
|
{
|
|
dbg_log (_("\
|
|
cannot open /proc/self/cmdline: %m; disabling paranoia mode"));
|
|
paranoia = 0;
|
|
return;
|
|
}
|
|
|
|
/* Parse the command line. Worst case scenario: every two
|
|
characters form one parameter (one character plus NUL). */
|
|
char **argv = alloca ((readlen / 2 + 1) * sizeof (argv[0]));
|
|
int argc = 0;
|
|
|
|
for (char *cp = cmdline; cp < cmdline + readlen;)
|
|
{
|
|
argv[argc++] = cp;
|
|
cp = strchr (cp, '\0') + 1;
|
|
}
|
|
argv[argc] = NULL;
|
|
|
|
/* Second, change back to the old user if we changed it. */
|
|
if (server_user != NULL)
|
|
{
|
|
if (setresuid (old_uid, old_uid, old_uid) != 0)
|
|
{
|
|
dbg_log (_("\
|
|
cannot change to old UID: %s; disabling paranoia mode"),
|
|
strerror (errno));
|
|
|
|
paranoia = 0;
|
|
free (cmdline);
|
|
return;
|
|
}
|
|
|
|
if (setresgid (old_gid, old_gid, old_gid) != 0)
|
|
{
|
|
dbg_log (_("\
|
|
cannot change to old GID: %s; disabling paranoia mode"),
|
|
strerror (errno));
|
|
|
|
ignore_value (setuid (server_uid));
|
|
paranoia = 0;
|
|
free (cmdline);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Next change back to the old working directory. */
|
|
if (chdir (oldcwd) == -1)
|
|
{
|
|
dbg_log (_("\
|
|
cannot change to old working directory: %s; disabling paranoia mode"),
|
|
strerror (errno));
|
|
|
|
if (server_user != NULL)
|
|
{
|
|
ignore_value (setuid (server_uid));
|
|
ignore_value (setgid (server_gid));
|
|
}
|
|
paranoia = 0;
|
|
free (cmdline);
|
|
return;
|
|
}
|
|
|
|
/* Synchronize memory. */
|
|
int32_t certainly[lastdb];
|
|
for (int cnt = 0; cnt < lastdb; ++cnt)
|
|
if (dbs[cnt].enabled)
|
|
{
|
|
/* Make sure nobody keeps using the database. */
|
|
dbs[cnt].head->timestamp = 0;
|
|
certainly[cnt] = dbs[cnt].head->nscd_certainly_running;
|
|
dbs[cnt].head->nscd_certainly_running = 0;
|
|
|
|
if (dbs[cnt].persistent)
|
|
// XXX async OK?
|
|
msync (dbs[cnt].head, dbs[cnt].memsize, MS_ASYNC);
|
|
}
|
|
|
|
/* The preparations are done. */
|
|
#ifdef PATH_MAX
|
|
char pathbuf[PATH_MAX];
|
|
#else
|
|
char pathbuf[256];
|
|
#endif
|
|
/* Try to exec the real nscd program so the process name (as reported
|
|
in /proc/PID/status) will be 'nscd', but fall back to /proc/self/exe
|
|
if readlink or the exec with the result of the readlink call fails. */
|
|
ssize_t n = readlink ("/proc/self/exe", pathbuf, sizeof (pathbuf) - 1);
|
|
if (n != -1)
|
|
{
|
|
pathbuf[n] = '\0';
|
|
execv (pathbuf, argv);
|
|
}
|
|
execv ("/proc/self/exe", argv);
|
|
|
|
/* If we come here, we will never be able to re-exec. */
|
|
dbg_log (_("re-exec failed: %s; disabling paranoia mode"),
|
|
strerror (errno));
|
|
|
|
if (server_user != NULL)
|
|
{
|
|
ignore_value (setuid (server_uid));
|
|
ignore_value (setgid (server_gid));
|
|
}
|
|
if (chdir ("/") != 0)
|
|
dbg_log (_("cannot change current working directory to \"/\": %s"),
|
|
strerror (errno));
|
|
paranoia = 0;
|
|
free (cmdline);
|
|
|
|
/* Re-enable the databases. */
|
|
time_t now = time (NULL);
|
|
for (int cnt = 0; cnt < lastdb; ++cnt)
|
|
if (dbs[cnt].enabled)
|
|
{
|
|
dbs[cnt].head->timestamp = now;
|
|
dbs[cnt].head->nscd_certainly_running = certainly[cnt];
|
|
}
|
|
}
|
|
|
|
|
|
/* List of file descriptors. */
|
|
struct fdlist
|
|
{
|
|
int fd;
|
|
struct fdlist *next;
|
|
};
|
|
/* Memory allocated for the list. */
|
|
static struct fdlist *fdlist;
|
|
/* List of currently ready-to-read file descriptors. */
|
|
static struct fdlist *readylist;
|
|
|
|
/* Conditional variable and mutex to signal availability of entries in
|
|
READYLIST. The condvar is initialized dynamically since we might
|
|
use a different clock depending on availability. */
|
|
static pthread_cond_t readylist_cond = PTHREAD_COND_INITIALIZER;
|
|
static pthread_mutex_t readylist_lock = PTHREAD_MUTEX_INITIALIZER;
|
|
|
|
/* The clock to use with the condvar. */
|
|
static clockid_t timeout_clock = CLOCK_REALTIME;
|
|
|
|
/* Number of threads ready to handle the READYLIST. */
|
|
static unsigned long int nready;
|
|
|
|
|
|
/* Function for the clean-up threads. */
|
|
static void *
|
|
__attribute__ ((__noreturn__))
|
|
nscd_run_prune (void *p)
|
|
{
|
|
const long int my_number = (long int) p;
|
|
assert (dbs[my_number].enabled);
|
|
|
|
int dont_need_update = setup_thread (&dbs[my_number]);
|
|
|
|
time_t now = time (NULL);
|
|
|
|
/* We are running. */
|
|
dbs[my_number].head->timestamp = now;
|
|
|
|
struct timespec prune_ts;
|
|
if (__glibc_unlikely (clock_gettime (timeout_clock, &prune_ts) == -1))
|
|
/* Should never happen. */
|
|
abort ();
|
|
|
|
/* Compute the initial timeout time. Prevent all the timers to go
|
|
off at the same time by adding a db-based value. */
|
|
prune_ts.tv_sec += CACHE_PRUNE_INTERVAL + my_number;
|
|
dbs[my_number].wakeup_time = now + CACHE_PRUNE_INTERVAL + my_number;
|
|
|
|
pthread_mutex_t *prune_lock = &dbs[my_number].prune_lock;
|
|
pthread_mutex_t *prune_run_lock = &dbs[my_number].prune_run_lock;
|
|
pthread_cond_t *prune_cond = &dbs[my_number].prune_cond;
|
|
|
|
pthread_mutex_lock (prune_lock);
|
|
while (1)
|
|
{
|
|
/* Wait, but not forever. */
|
|
int e = 0;
|
|
if (! dbs[my_number].clear_cache)
|
|
e = pthread_cond_timedwait (prune_cond, prune_lock, &prune_ts);
|
|
assert (__builtin_expect (e == 0 || e == ETIMEDOUT, 1));
|
|
|
|
time_t next_wait;
|
|
now = time (NULL);
|
|
if (e == ETIMEDOUT || now >= dbs[my_number].wakeup_time
|
|
|| dbs[my_number].clear_cache)
|
|
{
|
|
/* We will determine the new timeout values based on the
|
|
cache content. Should there be concurrent additions to
|
|
the cache which are not accounted for in the cache
|
|
pruning we want to know about it. Therefore set the
|
|
timeout to the maximum. It will be decreased when adding
|
|
new entries to the cache, if necessary. */
|
|
dbs[my_number].wakeup_time = MAX_TIMEOUT_VALUE;
|
|
|
|
/* Unconditionally reset the flag. */
|
|
time_t prune_now = dbs[my_number].clear_cache ? LONG_MAX : now;
|
|
dbs[my_number].clear_cache = 0;
|
|
|
|
pthread_mutex_unlock (prune_lock);
|
|
|
|
/* We use a separate lock for running the prune function (instead
|
|
of keeping prune_lock locked) because this enables concurrent
|
|
invocations of cache_add which might modify the timeout value. */
|
|
pthread_mutex_lock (prune_run_lock);
|
|
next_wait = prune_cache (&dbs[my_number], prune_now, -1);
|
|
pthread_mutex_unlock (prune_run_lock);
|
|
|
|
next_wait = MAX (next_wait, CACHE_PRUNE_INTERVAL);
|
|
/* If clients cannot determine for sure whether nscd is running
|
|
we need to wake up occasionally to update the timestamp.
|
|
Wait 90% of the update period. */
|
|
#define UPDATE_MAPPING_TIMEOUT (MAPPING_TIMEOUT * 9 / 10)
|
|
if (__glibc_unlikely (! dont_need_update))
|
|
{
|
|
next_wait = MIN (UPDATE_MAPPING_TIMEOUT, next_wait);
|
|
dbs[my_number].head->timestamp = now;
|
|
}
|
|
|
|
pthread_mutex_lock (prune_lock);
|
|
|
|
/* Make it known when we will wake up again. */
|
|
if (now + next_wait < dbs[my_number].wakeup_time)
|
|
dbs[my_number].wakeup_time = now + next_wait;
|
|
else
|
|
next_wait = dbs[my_number].wakeup_time - now;
|
|
}
|
|
else
|
|
/* The cache was just pruned. Do not do it again now. Just
|
|
use the new timeout value. */
|
|
next_wait = dbs[my_number].wakeup_time - now;
|
|
|
|
if (clock_gettime (timeout_clock, &prune_ts) == -1)
|
|
/* Should never happen. */
|
|
abort ();
|
|
|
|
/* Compute next timeout time. */
|
|
prune_ts.tv_sec += next_wait;
|
|
}
|
|
}
|
|
|
|
|
|
/* This is the main loop. It is replicated in different threads but
|
|
the use of the ready list makes sure only one thread handles an
|
|
incoming connection. */
|
|
static void *
|
|
__attribute__ ((__noreturn__))
|
|
nscd_run_worker (void *p)
|
|
{
|
|
char buf[256];
|
|
|
|
/* Initial locking. */
|
|
pthread_mutex_lock (&readylist_lock);
|
|
|
|
/* One more thread available. */
|
|
++nready;
|
|
|
|
while (1)
|
|
{
|
|
while (readylist == NULL)
|
|
pthread_cond_wait (&readylist_cond, &readylist_lock);
|
|
|
|
struct fdlist *it = readylist->next;
|
|
if (readylist->next == readylist)
|
|
/* Just one entry on the list. */
|
|
readylist = NULL;
|
|
else
|
|
readylist->next = it->next;
|
|
|
|
/* Extract the information and mark the record ready to be used
|
|
again. */
|
|
int fd = it->fd;
|
|
it->next = NULL;
|
|
|
|
/* One more thread available. */
|
|
--nready;
|
|
|
|
/* We are done with the list. */
|
|
pthread_mutex_unlock (&readylist_lock);
|
|
|
|
/* Now read the request. */
|
|
request_header req;
|
|
if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, &req, sizeof (req)))
|
|
!= sizeof (req), 0))
|
|
{
|
|
/* We failed to read data. Note that this also might mean we
|
|
failed because we would have blocked. */
|
|
if (debug_level > 0)
|
|
dbg_log (_("short read while reading request: %s"),
|
|
strerror_r (errno, buf, sizeof (buf)));
|
|
goto close_and_out;
|
|
}
|
|
|
|
/* Check whether this is a valid request type. */
|
|
if (req.type < GETPWBYNAME || req.type >= LASTREQ)
|
|
goto close_and_out;
|
|
|
|
/* Some systems have no SO_PEERCRED implementation. They don't
|
|
care about security so we don't as well. */
|
|
uid_t uid = -1;
|
|
#ifdef SO_PEERCRED
|
|
pid_t pid = 0;
|
|
|
|
if (__glibc_unlikely (debug_level > 0))
|
|
{
|
|
struct ucred caller;
|
|
socklen_t optlen = sizeof (caller);
|
|
|
|
if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, &caller, &optlen) == 0)
|
|
pid = caller.pid;
|
|
}
|
|
#else
|
|
const pid_t pid = 0;
|
|
#endif
|
|
|
|
/* It should not be possible to crash the nscd with a silly
|
|
request (i.e., a terribly large key). We limit the size to 1kb. */
|
|
if (__builtin_expect (req.key_len, 1) < 0
|
|
|| __builtin_expect (req.key_len, 1) > MAXKEYLEN)
|
|
{
|
|
if (debug_level > 0)
|
|
dbg_log (_("key length in request too long: %d"), req.key_len);
|
|
}
|
|
else
|
|
{
|
|
/* Get the key. */
|
|
char keybuf[MAXKEYLEN + 1];
|
|
|
|
if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, keybuf,
|
|
req.key_len))
|
|
!= req.key_len, 0))
|
|
{
|
|
/* Again, this can also mean we would have blocked. */
|
|
if (debug_level > 0)
|
|
dbg_log (_("short read while reading request key: %s"),
|
|
strerror_r (errno, buf, sizeof (buf)));
|
|
goto close_and_out;
|
|
}
|
|
keybuf[req.key_len] = '\0';
|
|
|
|
if (__builtin_expect (debug_level, 0) > 0)
|
|
{
|
|
#ifdef SO_PEERCRED
|
|
if (pid != 0)
|
|
dbg_log (_("\
|
|
handle_request: request received (Version = %d) from PID %ld"),
|
|
req.version, (long int) pid);
|
|
else
|
|
#endif
|
|
dbg_log (_("\
|
|
handle_request: request received (Version = %d)"), req.version);
|
|
}
|
|
|
|
/* Phew, we got all the data, now process it. */
|
|
handle_request (fd, &req, keybuf, uid, pid);
|
|
}
|
|
|
|
close_and_out:
|
|
/* We are done. */
|
|
close (fd);
|
|
|
|
/* Re-locking. */
|
|
pthread_mutex_lock (&readylist_lock);
|
|
|
|
/* One more thread available. */
|
|
++nready;
|
|
}
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
|
|
static unsigned int nconns;
|
|
|
|
static void
|
|
fd_ready (int fd)
|
|
{
|
|
pthread_mutex_lock (&readylist_lock);
|
|
|
|
/* Find an empty entry in FDLIST. */
|
|
size_t inner;
|
|
for (inner = 0; inner < nconns; ++inner)
|
|
if (fdlist[inner].next == NULL)
|
|
break;
|
|
assert (inner < nconns);
|
|
|
|
fdlist[inner].fd = fd;
|
|
|
|
if (readylist == NULL)
|
|
readylist = fdlist[inner].next = &fdlist[inner];
|
|
else
|
|
{
|
|
fdlist[inner].next = readylist->next;
|
|
readylist = readylist->next = &fdlist[inner];
|
|
}
|
|
|
|
bool do_signal = true;
|
|
if (__glibc_unlikely (nready == 0))
|
|
{
|
|
++client_queued;
|
|
do_signal = false;
|
|
|
|
/* Try to start another thread to help out. */
|
|
pthread_t th;
|
|
if (nthreads < max_nthreads
|
|
&& pthread_create (&th, &attr, nscd_run_worker,
|
|
(void *) (long int) nthreads) == 0)
|
|
{
|
|
/* We got another thread. */
|
|
++nthreads;
|
|
/* The new thread might need a kick. */
|
|
do_signal = true;
|
|
}
|
|
|
|
}
|
|
|
|
pthread_mutex_unlock (&readylist_lock);
|
|
|
|
/* Tell one of the worker threads there is work to do. */
|
|
if (do_signal)
|
|
pthread_cond_signal (&readylist_cond);
|
|
}
|
|
|
|
|
|
/* Check whether restarting should happen. */
|
|
static bool
|
|
restart_p (time_t now)
|
|
{
|
|
return (paranoia && readylist == NULL && nready == nthreads
|
|
&& now >= restart_time);
|
|
}
|
|
|
|
|
|
/* Array for times a connection was accepted. */
|
|
static time_t *starttime;
|
|
|
|
#ifdef HAVE_INOTIFY
|
|
/* Inotify event for changed file. */
|
|
union __inev
|
|
{
|
|
struct inotify_event i;
|
|
# ifndef PATH_MAX
|
|
# define PATH_MAX 1024
|
|
# endif
|
|
char buf[sizeof (struct inotify_event) + PATH_MAX];
|
|
};
|
|
|
|
/* Returns 0 if the file is there otherwise -1. */
|
|
int
|
|
check_file (struct traced_file *finfo)
|
|
{
|
|
struct stat64 st;
|
|
/* We could check mtime and if different re-add
|
|
the watches, and invalidate the database, but we
|
|
don't because we are called from inotify_check_files
|
|
which should be doing that work. If sufficient inotify
|
|
events were lost then the next pruning or invalidation
|
|
will do the stat and mtime check. We don't do it here to
|
|
keep the logic simple. */
|
|
if (stat64 (finfo->fname, &st) < 0)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
/* Process the inotify event in INEV. If the event matches any of the files
|
|
registered with a database then mark that database as requiring its cache
|
|
to be cleared. We indicate the cache needs clearing by setting
|
|
TO_CLEAR[DBCNT] to true for the matching database. */
|
|
static void
|
|
inotify_check_files (bool *to_clear, union __inev *inev)
|
|
{
|
|
/* Check which of the files changed. */
|
|
for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt)
|
|
{
|
|
struct traced_file *finfo = dbs[dbcnt].traced_files;
|
|
|
|
while (finfo != NULL)
|
|
{
|
|
/* The configuration file was moved or deleted.
|
|
We stop watching it at that point, and reinitialize. */
|
|
if (finfo->inotify_descr[TRACED_FILE] == inev->i.wd
|
|
&& ((inev->i.mask & IN_MOVE_SELF)
|
|
|| (inev->i.mask & IN_DELETE_SELF)
|
|
|| (inev->i.mask & IN_IGNORED)))
|
|
{
|
|
int ret;
|
|
bool moved = (inev->i.mask & IN_MOVE_SELF) != 0;
|
|
|
|
if (check_file (finfo) == 0)
|
|
{
|
|
dbg_log (_("ignored inotify event for `%s` (file exists)"),
|
|
finfo->fname);
|
|
return;
|
|
}
|
|
|
|
dbg_log (_("monitored file `%s` was %s, removing watch"),
|
|
finfo->fname, moved ? "moved" : "deleted");
|
|
/* File was moved out, remove the watch. Watches are
|
|
automatically removed when the file is deleted. */
|
|
if (moved)
|
|
{
|
|
ret = inotify_rm_watch (inotify_fd, inev->i.wd);
|
|
if (ret < 0)
|
|
dbg_log (_("failed to remove file watch `%s`: %s"),
|
|
finfo->fname, strerror (errno));
|
|
}
|
|
finfo->inotify_descr[TRACED_FILE] = -1;
|
|
to_clear[dbcnt] = true;
|
|
if (finfo->call_res_init)
|
|
res_init ();
|
|
return;
|
|
}
|
|
/* The configuration file was open for writing and has just closed.
|
|
We reset the cache and reinitialize. */
|
|
if (finfo->inotify_descr[TRACED_FILE] == inev->i.wd
|
|
&& inev->i.mask & IN_CLOSE_WRITE)
|
|
{
|
|
/* Mark cache as needing to be cleared and reinitialize. */
|
|
dbg_log (_("monitored file `%s` was written to"), finfo->fname);
|
|
to_clear[dbcnt] = true;
|
|
if (finfo->call_res_init)
|
|
res_init ();
|
|
return;
|
|
}
|
|
/* The parent directory was moved or deleted. We trigger one last
|
|
invalidation. At the next pruning or invalidation we may add
|
|
this watch back if the file is present again. */
|
|
if (finfo->inotify_descr[TRACED_DIR] == inev->i.wd
|
|
&& ((inev->i.mask & IN_DELETE_SELF)
|
|
|| (inev->i.mask & IN_MOVE_SELF)
|
|
|| (inev->i.mask & IN_IGNORED)))
|
|
{
|
|
bool moved = (inev->i.mask & IN_MOVE_SELF) != 0;
|
|
/* The directory watch may have already been removed
|
|
but we don't know so we just remove it again and
|
|
ignore the error. Then we remove the file watch.
|
|
Note: watches are automatically removed for deleted
|
|
files. */
|
|
if (moved)
|
|
inotify_rm_watch (inotify_fd, inev->i.wd);
|
|
if (finfo->inotify_descr[TRACED_FILE] != -1)
|
|
{
|
|
dbg_log (_("monitored parent directory `%s` was %s, removing watch on `%s`"),
|
|
finfo->dname, moved ? "moved" : "deleted", finfo->fname);
|
|
if (inotify_rm_watch (inotify_fd, finfo->inotify_descr[TRACED_FILE]) < 0)
|
|
dbg_log (_("failed to remove file watch `%s`: %s"),
|
|
finfo->dname, strerror (errno));
|
|
}
|
|
finfo->inotify_descr[TRACED_FILE] = -1;
|
|
finfo->inotify_descr[TRACED_DIR] = -1;
|
|
to_clear[dbcnt] = true;
|
|
if (finfo->call_res_init)
|
|
res_init ();
|
|
/* Continue to the next entry since this might be the
|
|
parent directory for multiple registered files and
|
|
we want to remove watches for all registered files. */
|
|
continue;
|
|
}
|
|
/* The parent directory had a create or moved to event. */
|
|
if (finfo->inotify_descr[TRACED_DIR] == inev->i.wd
|
|
&& ((inev->i.mask & IN_MOVED_TO)
|
|
|| (inev->i.mask & IN_CREATE))
|
|
&& strcmp (inev->i.name, finfo->sfname) == 0)
|
|
{
|
|
/* We detected a directory change. We look for the creation
|
|
of the file we are tracking or the move of the same file
|
|
into the directory. */
|
|
int ret;
|
|
dbg_log (_("monitored file `%s` was %s, adding watch"),
|
|
finfo->fname,
|
|
inev->i.mask & IN_CREATE ? "created" : "moved into place");
|
|
/* File was moved in or created. Regenerate the watch. */
|
|
if (finfo->inotify_descr[TRACED_FILE] != -1)
|
|
inotify_rm_watch (inotify_fd,
|
|
finfo->inotify_descr[TRACED_FILE]);
|
|
|
|
ret = inotify_add_watch (inotify_fd,
|
|
finfo->fname,
|
|
TRACED_FILE_MASK);
|
|
if (ret < 0)
|
|
dbg_log (_("failed to add file watch `%s`: %s"),
|
|
finfo->fname, strerror (errno));
|
|
|
|
finfo->inotify_descr[TRACED_FILE] = ret;
|
|
|
|
/* The file is new or moved so mark cache as needing to
|
|
be cleared and reinitialize. */
|
|
to_clear[dbcnt] = true;
|
|
if (finfo->call_res_init)
|
|
res_init ();
|
|
|
|
/* Done re-adding the watch. Don't return, we may still
|
|
have other files in this same directory, same watch
|
|
descriptor, and need to process them. */
|
|
}
|
|
/* Other events are ignored, and we move on to the next file. */
|
|
finfo = finfo->next;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* If an entry in the array of booleans TO_CLEAR is TRUE then clear the cache
|
|
for the associated database, otherwise do nothing. The TO_CLEAR array must
|
|
have LASTDB entries. */
|
|
static inline void
|
|
clear_db_cache (bool *to_clear)
|
|
{
|
|
for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt)
|
|
if (to_clear[dbcnt])
|
|
{
|
|
pthread_mutex_lock (&dbs[dbcnt].prune_lock);
|
|
dbs[dbcnt].clear_cache = 1;
|
|
pthread_mutex_unlock (&dbs[dbcnt].prune_lock);
|
|
pthread_cond_signal (&dbs[dbcnt].prune_cond);
|
|
}
|
|
}
|
|
|
|
int
|
|
handle_inotify_events (void)
|
|
{
|
|
bool to_clear[lastdb] = { false, };
|
|
union __inev inev;
|
|
|
|
/* Read all inotify events for files registered via
|
|
register_traced_file(). */
|
|
while (1)
|
|
{
|
|
/* Potentially read multiple events into buf. */
|
|
ssize_t nb = TEMP_FAILURE_RETRY (read (inotify_fd,
|
|
&inev.buf,
|
|
sizeof (inev)));
|
|
if (nb < (ssize_t) sizeof (struct inotify_event))
|
|
{
|
|
/* Not even 1 event. */
|
|
if (__glibc_unlikely (nb == -1 && errno != EAGAIN))
|
|
return -1;
|
|
/* Done reading events that are ready. */
|
|
break;
|
|
}
|
|
/* Process all events. The normal inotify interface delivers
|
|
complete events on a read and never a partial event. */
|
|
char *eptr = &inev.buf[0];
|
|
ssize_t count;
|
|
while (1)
|
|
{
|
|
/* Check which of the files changed. */
|
|
inotify_check_files (to_clear, &inev);
|
|
count = sizeof (struct inotify_event) + inev.i.len;
|
|
eptr += count;
|
|
nb -= count;
|
|
if (nb >= (ssize_t) sizeof (struct inotify_event))
|
|
memcpy (&inev, eptr, nb);
|
|
else
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
/* Actually perform the cache clearing. */
|
|
clear_db_cache (to_clear);
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
static void
|
|
__attribute__ ((__noreturn__))
|
|
main_loop_poll (void)
|
|
{
|
|
struct pollfd *conns = (struct pollfd *) xmalloc (nconns
|
|
* sizeof (conns[0]));
|
|
|
|
conns[0].fd = sock;
|
|
conns[0].events = POLLRDNORM;
|
|
size_t nused = 1;
|
|
size_t firstfree = 1;
|
|
|
|
#ifdef HAVE_INOTIFY
|
|
if (inotify_fd != -1)
|
|
{
|
|
conns[1].fd = inotify_fd;
|
|
conns[1].events = POLLRDNORM;
|
|
nused = 2;
|
|
firstfree = 2;
|
|
}
|
|
#endif
|
|
|
|
#ifdef HAVE_NETLINK
|
|
size_t idx_nl_status_fd = 0;
|
|
if (nl_status_fd != -1)
|
|
{
|
|
idx_nl_status_fd = nused;
|
|
conns[nused].fd = nl_status_fd;
|
|
conns[nused].events = POLLRDNORM;
|
|
++nused;
|
|
firstfree = nused;
|
|
}
|
|
#endif
|
|
|
|
while (1)
|
|
{
|
|
/* Wait for any event. We wait at most a couple of seconds so
|
|
that we can check whether we should close any of the accepted
|
|
connections since we have not received a request. */
|
|
#define MAX_ACCEPT_TIMEOUT 30
|
|
#define MIN_ACCEPT_TIMEOUT 5
|
|
#define MAIN_THREAD_TIMEOUT \
|
|
(MAX_ACCEPT_TIMEOUT * 1000 \
|
|
- ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * 1000 * nused) / (2 * nconns))
|
|
|
|
int n = poll (conns, nused, MAIN_THREAD_TIMEOUT);
|
|
|
|
time_t now = time (NULL);
|
|
|
|
/* If there is a descriptor ready for reading or there is a new
|
|
connection, process this now. */
|
|
if (n > 0)
|
|
{
|
|
if (conns[0].revents != 0)
|
|
{
|
|
/* We have a new incoming connection. Accept the connection. */
|
|
int fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL,
|
|
SOCK_NONBLOCK));
|
|
|
|
/* Use the descriptor if we have not reached the limit. */
|
|
if (fd >= 0)
|
|
{
|
|
if (firstfree < nconns)
|
|
{
|
|
conns[firstfree].fd = fd;
|
|
conns[firstfree].events = POLLRDNORM;
|
|
starttime[firstfree] = now;
|
|
if (firstfree >= nused)
|
|
nused = firstfree + 1;
|
|
|
|
do
|
|
++firstfree;
|
|
while (firstfree < nused && conns[firstfree].fd != -1);
|
|
}
|
|
else
|
|
/* We cannot use the connection so close it. */
|
|
close (fd);
|
|
}
|
|
|
|
--n;
|
|
}
|
|
|
|
size_t first = 1;
|
|
#ifdef HAVE_INOTIFY
|
|
if (inotify_fd != -1 && conns[1].fd == inotify_fd)
|
|
{
|
|
if (conns[1].revents != 0)
|
|
{
|
|
int ret;
|
|
ret = handle_inotify_events ();
|
|
if (ret == -1)
|
|
{
|
|
/* Something went wrong when reading the inotify
|
|
data. Better disable inotify. */
|
|
dbg_log (_("disabled inotify-based monitoring after read error %d"), errno);
|
|
conns[1].fd = -1;
|
|
firstfree = 1;
|
|
if (nused == 2)
|
|
nused = 1;
|
|
close (inotify_fd);
|
|
inotify_fd = -1;
|
|
}
|
|
--n;
|
|
}
|
|
|
|
first = 2;
|
|
}
|
|
#endif
|
|
|
|
#ifdef HAVE_NETLINK
|
|
if (idx_nl_status_fd != 0 && conns[idx_nl_status_fd].revents != 0)
|
|
{
|
|
char buf[4096];
|
|
/* Read all the data. We do not interpret it here. */
|
|
while (TEMP_FAILURE_RETRY (read (nl_status_fd, buf,
|
|
sizeof (buf))) != -1)
|
|
;
|
|
|
|
dbs[hstdb].head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP]
|
|
= __bump_nl_timestamp ();
|
|
}
|
|
#endif
|
|
|
|
for (size_t cnt = first; cnt < nused && n > 0; ++cnt)
|
|
if (conns[cnt].revents != 0)
|
|
{
|
|
fd_ready (conns[cnt].fd);
|
|
|
|
/* Clean up the CONNS array. */
|
|
conns[cnt].fd = -1;
|
|
if (cnt < firstfree)
|
|
firstfree = cnt;
|
|
if (cnt == nused - 1)
|
|
do
|
|
--nused;
|
|
while (conns[nused - 1].fd == -1);
|
|
|
|
--n;
|
|
}
|
|
}
|
|
|
|
/* Now find entries which have timed out. */
|
|
assert (nused > 0);
|
|
|
|
/* We make the timeout length depend on the number of file
|
|
descriptors currently used. */
|
|
#define ACCEPT_TIMEOUT \
|
|
(MAX_ACCEPT_TIMEOUT \
|
|
- ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * nused) / nconns)
|
|
time_t laststart = now - ACCEPT_TIMEOUT;
|
|
|
|
for (size_t cnt = nused - 1; cnt > 0; --cnt)
|
|
{
|
|
if (conns[cnt].fd != -1 && starttime[cnt] < laststart)
|
|
{
|
|
/* Remove the entry, it timed out. */
|
|
(void) close (conns[cnt].fd);
|
|
conns[cnt].fd = -1;
|
|
|
|
if (cnt < firstfree)
|
|
firstfree = cnt;
|
|
if (cnt == nused - 1)
|
|
do
|
|
--nused;
|
|
while (conns[nused - 1].fd == -1);
|
|
}
|
|
}
|
|
|
|
if (restart_p (now))
|
|
restart ();
|
|
}
|
|
}
|
|
|
|
|
|
#ifdef HAVE_EPOLL
|
|
static void
|
|
main_loop_epoll (int efd)
|
|
{
|
|
struct epoll_event ev = { 0, };
|
|
int nused = 1;
|
|
size_t highest = 0;
|
|
|
|
/* Add the socket. */
|
|
ev.events = EPOLLRDNORM;
|
|
ev.data.fd = sock;
|
|
if (epoll_ctl (efd, EPOLL_CTL_ADD, sock, &ev) == -1)
|
|
/* We cannot use epoll. */
|
|
return;
|
|
|
|
# ifdef HAVE_INOTIFY
|
|
if (inotify_fd != -1)
|
|
{
|
|
ev.events = EPOLLRDNORM;
|
|
ev.data.fd = inotify_fd;
|
|
if (epoll_ctl (efd, EPOLL_CTL_ADD, inotify_fd, &ev) == -1)
|
|
/* We cannot use epoll. */
|
|
return;
|
|
nused = 2;
|
|
}
|
|
# endif
|
|
|
|
# ifdef HAVE_NETLINK
|
|
if (nl_status_fd != -1)
|
|
{
|
|
ev.events = EPOLLRDNORM;
|
|
ev.data.fd = nl_status_fd;
|
|
if (epoll_ctl (efd, EPOLL_CTL_ADD, nl_status_fd, &ev) == -1)
|
|
/* We cannot use epoll. */
|
|
return;
|
|
}
|
|
# endif
|
|
|
|
while (1)
|
|
{
|
|
struct epoll_event revs[100];
|
|
# define nrevs (sizeof (revs) / sizeof (revs[0]))
|
|
|
|
int n = epoll_wait (efd, revs, nrevs, MAIN_THREAD_TIMEOUT);
|
|
|
|
time_t now = time (NULL);
|
|
|
|
for (int cnt = 0; cnt < n; ++cnt)
|
|
if (revs[cnt].data.fd == sock)
|
|
{
|
|
/* A new connection. */
|
|
int fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL,
|
|
SOCK_NONBLOCK));
|
|
|
|
/* Use the descriptor if we have not reached the limit. */
|
|
if (fd >= 0)
|
|
{
|
|
/* Try to add the new descriptor. */
|
|
ev.data.fd = fd;
|
|
if (fd >= nconns
|
|
|| epoll_ctl (efd, EPOLL_CTL_ADD, fd, &ev) == -1)
|
|
/* The descriptor is too large or something went
|
|
wrong. Close the descriptor. */
|
|
close (fd);
|
|
else
|
|
{
|
|
/* Remember when we accepted the connection. */
|
|
starttime[fd] = now;
|
|
|
|
if (fd > highest)
|
|
highest = fd;
|
|
|
|
++nused;
|
|
}
|
|
}
|
|
}
|
|
# ifdef HAVE_INOTIFY
|
|
else if (revs[cnt].data.fd == inotify_fd)
|
|
{
|
|
int ret;
|
|
ret = handle_inotify_events ();
|
|
if (ret == -1)
|
|
{
|
|
/* Something went wrong when reading the inotify
|
|
data. Better disable inotify. */
|
|
dbg_log (_("disabled inotify-based monitoring after read error %d"), errno);
|
|
(void) epoll_ctl (efd, EPOLL_CTL_DEL, inotify_fd, NULL);
|
|
close (inotify_fd);
|
|
inotify_fd = -1;
|
|
break;
|
|
}
|
|
}
|
|
# endif
|
|
# ifdef HAVE_NETLINK
|
|
else if (revs[cnt].data.fd == nl_status_fd)
|
|
{
|
|
char buf[4096];
|
|
/* Read all the data. We do not interpret it here. */
|
|
while (TEMP_FAILURE_RETRY (read (nl_status_fd, buf,
|
|
sizeof (buf))) != -1)
|
|
;
|
|
|
|
dbs[hstdb].head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP]
|
|
= __bump_nl_timestamp ();
|
|
}
|
|
# endif
|
|
else
|
|
{
|
|
/* Remove the descriptor from the epoll descriptor. */
|
|
(void) epoll_ctl (efd, EPOLL_CTL_DEL, revs[cnt].data.fd, NULL);
|
|
|
|
/* Get a worker to handle the request. */
|
|
fd_ready (revs[cnt].data.fd);
|
|
|
|
/* Reset the time. */
|
|
starttime[revs[cnt].data.fd] = 0;
|
|
if (revs[cnt].data.fd == highest)
|
|
do
|
|
--highest;
|
|
while (highest > 0 && starttime[highest] == 0);
|
|
|
|
--nused;
|
|
}
|
|
|
|
/* Now look for descriptors for accepted connections which have
|
|
no reply in too long of a time. */
|
|
time_t laststart = now - ACCEPT_TIMEOUT;
|
|
assert (starttime[sock] == 0);
|
|
# ifdef HAVE_INOTIFY
|
|
assert (inotify_fd == -1 || starttime[inotify_fd] == 0);
|
|
# endif
|
|
assert (nl_status_fd == -1 || starttime[nl_status_fd] == 0);
|
|
for (int cnt = highest; cnt > STDERR_FILENO; --cnt)
|
|
if (starttime[cnt] != 0 && starttime[cnt] < laststart)
|
|
{
|
|
/* We are waiting for this one for too long. Close it. */
|
|
(void) epoll_ctl (efd, EPOLL_CTL_DEL, cnt, NULL);
|
|
|
|
(void) close (cnt);
|
|
|
|
starttime[cnt] = 0;
|
|
if (cnt == highest)
|
|
--highest;
|
|
}
|
|
else if (cnt != sock && starttime[cnt] == 0 && cnt == highest)
|
|
--highest;
|
|
|
|
if (restart_p (now))
|
|
restart ();
|
|
}
|
|
}
|
|
#endif
|
|
|
|
|
|
/* Start all the threads we want. The initial process is thread no. 1. */
|
|
void
|
|
start_threads (void)
|
|
{
|
|
/* Initialize the conditional variable we will use. The only
|
|
non-standard attribute we might use is the clock selection. */
|
|
pthread_condattr_t condattr;
|
|
pthread_condattr_init (&condattr);
|
|
|
|
#if defined _POSIX_CLOCK_SELECTION && _POSIX_CLOCK_SELECTION >= 0 \
|
|
&& defined _POSIX_MONOTONIC_CLOCK && _POSIX_MONOTONIC_CLOCK >= 0
|
|
/* Determine whether the monotonous clock is available. */
|
|
struct timespec dummy;
|
|
# if _POSIX_MONOTONIC_CLOCK == 0
|
|
if (sysconf (_SC_MONOTONIC_CLOCK) > 0)
|
|
# endif
|
|
# if _POSIX_CLOCK_SELECTION == 0
|
|
if (sysconf (_SC_CLOCK_SELECTION) > 0)
|
|
# endif
|
|
if (clock_getres (CLOCK_MONOTONIC, &dummy) == 0
|
|
&& pthread_condattr_setclock (&condattr, CLOCK_MONOTONIC) == 0)
|
|
timeout_clock = CLOCK_MONOTONIC;
|
|
#endif
|
|
|
|
/* Create the attribute for the threads. They are all created
|
|
detached. */
|
|
pthread_attr_init (&attr);
|
|
pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
|
|
/* Use 1MB stacks, twice as much for 64-bit architectures. */
|
|
pthread_attr_setstacksize (&attr, NSCD_THREAD_STACKSIZE);
|
|
|
|
/* We allow less than LASTDB threads only for debugging. */
|
|
if (debug_level == 0)
|
|
nthreads = MAX (nthreads, lastdb);
|
|
|
|
/* Create the threads which prune the databases. */
|
|
// XXX Ideally this work would be done by some of the worker threads.
|
|
// XXX But this is problematic since we would need to be able to wake
|
|
// XXX them up explicitly as well as part of the group handling the
|
|
// XXX ready-list. This requires an operation where we can wait on
|
|
// XXX two conditional variables at the same time. This operation
|
|
// XXX does not exist (yet).
|
|
for (long int i = 0; i < lastdb; ++i)
|
|
{
|
|
/* Initialize the conditional variable. */
|
|
if (pthread_cond_init (&dbs[i].prune_cond, &condattr) != 0)
|
|
{
|
|
dbg_log (_("could not initialize conditional variable"));
|
|
do_exit (1, 0, NULL);
|
|
}
|
|
|
|
pthread_t th;
|
|
if (dbs[i].enabled
|
|
&& pthread_create (&th, &attr, nscd_run_prune, (void *) i) != 0)
|
|
{
|
|
dbg_log (_("could not start clean-up thread; terminating"));
|
|
do_exit (1, 0, NULL);
|
|
}
|
|
}
|
|
|
|
pthread_condattr_destroy (&condattr);
|
|
|
|
for (long int i = 0; i < nthreads; ++i)
|
|
{
|
|
pthread_t th;
|
|
if (pthread_create (&th, &attr, nscd_run_worker, NULL) != 0)
|
|
{
|
|
if (i == 0)
|
|
{
|
|
dbg_log (_("could not start any worker thread; terminating"));
|
|
do_exit (1, 0, NULL);
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Now it is safe to let the parent know that we're doing fine and it can
|
|
exit. */
|
|
notify_parent (0);
|
|
|
|
/* Determine how much room for descriptors we should initially
|
|
allocate. This might need to change later if we cap the number
|
|
with MAXCONN. */
|
|
const long int nfds = sysconf (_SC_OPEN_MAX);
|
|
#define MINCONN 32
|
|
#define MAXCONN 16384
|
|
if (nfds == -1 || nfds > MAXCONN)
|
|
nconns = MAXCONN;
|
|
else if (nfds < MINCONN)
|
|
nconns = MINCONN;
|
|
else
|
|
nconns = nfds;
|
|
|
|
/* We need memory to pass descriptors on to the worker threads. */
|
|
fdlist = (struct fdlist *) xcalloc (nconns, sizeof (fdlist[0]));
|
|
/* Array to keep track when connection was accepted. */
|
|
starttime = (time_t *) xcalloc (nconns, sizeof (starttime[0]));
|
|
|
|
/* In the main thread we execute the loop which handles incoming
|
|
connections. */
|
|
#ifdef HAVE_EPOLL
|
|
int efd = epoll_create (100);
|
|
if (efd != -1)
|
|
{
|
|
main_loop_epoll (efd);
|
|
close (efd);
|
|
}
|
|
#endif
|
|
|
|
main_loop_poll ();
|
|
}
|
|
|
|
|
|
/* Look up the uid, gid, and supplementary groups to run nscd as. When
|
|
this function is called, we are not listening on the nscd socket yet so
|
|
we can just use the ordinary lookup functions without causing a lockup */
|
|
static void
|
|
begin_drop_privileges (void)
|
|
{
|
|
struct passwd *pwd = getpwnam (server_user);
|
|
|
|
if (pwd == NULL)
|
|
{
|
|
dbg_log (_("Failed to run nscd as user '%s'"), server_user);
|
|
do_exit (EXIT_FAILURE, 0,
|
|
_("Failed to run nscd as user '%s'"), server_user);
|
|
}
|
|
|
|
server_uid = pwd->pw_uid;
|
|
server_gid = pwd->pw_gid;
|
|
|
|
/* Save the old UID/GID if we have to change back. */
|
|
if (paranoia)
|
|
{
|
|
old_uid = getuid ();
|
|
old_gid = getgid ();
|
|
}
|
|
|
|
if (getgrouplist (server_user, server_gid, NULL, &server_ngroups) == 0)
|
|
{
|
|
/* This really must never happen. */
|
|
dbg_log (_("Failed to run nscd as user '%s'"), server_user);
|
|
do_exit (EXIT_FAILURE, errno,
|
|
_("initial getgrouplist failed"));
|
|
}
|
|
|
|
server_groups = (gid_t *) xmalloc (server_ngroups * sizeof (gid_t));
|
|
|
|
if (getgrouplist (server_user, server_gid, server_groups, &server_ngroups)
|
|
== -1)
|
|
{
|
|
dbg_log (_("Failed to run nscd as user '%s'"), server_user);
|
|
do_exit (EXIT_FAILURE, errno, _("getgrouplist failed"));
|
|
}
|
|
}
|
|
|
|
|
|
/* Call setgroups(), setgid(), and setuid() to drop root privileges and
|
|
run nscd as the user specified in the configuration file. */
|
|
static void
|
|
finish_drop_privileges (void)
|
|
{
|
|
#if defined HAVE_LIBAUDIT && defined HAVE_LIBCAP
|
|
/* We need to preserve the capabilities to connect to the audit daemon. */
|
|
cap_t new_caps = preserve_capabilities ();
|
|
#endif
|
|
|
|
if (setgroups (server_ngroups, server_groups) == -1)
|
|
{
|
|
dbg_log (_("Failed to run nscd as user '%s'"), server_user);
|
|
do_exit (EXIT_FAILURE, errno, _("setgroups failed"));
|
|
}
|
|
|
|
int res;
|
|
if (paranoia)
|
|
res = setresgid (server_gid, server_gid, old_gid);
|
|
else
|
|
res = setgid (server_gid);
|
|
if (res == -1)
|
|
{
|
|
dbg_log (_("Failed to run nscd as user '%s'"), server_user);
|
|
do_exit (4, errno, "setgid");
|
|
}
|
|
|
|
if (paranoia)
|
|
res = setresuid (server_uid, server_uid, old_uid);
|
|
else
|
|
res = setuid (server_uid);
|
|
if (res == -1)
|
|
{
|
|
dbg_log (_("Failed to run nscd as user '%s'"), server_user);
|
|
do_exit (4, errno, "setuid");
|
|
}
|
|
|
|
#if defined HAVE_LIBAUDIT && defined HAVE_LIBCAP
|
|
/* Remove the temporary capabilities. */
|
|
install_real_capabilities (new_caps);
|
|
#endif
|
|
}
|