/*
 * 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 (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#ifndef _MAPID_H
#define _MAPID_H

#ifdef  __cplusplus
extern "C" {
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <strings.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <rpc/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <netdb.h>
#include <errno.h>
#include <ctype.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <assert.h>
#include <synch.h>
#include <syslog.h>
#include <locale.h>
#include <thread.h>
#include <deflt.h>
#include <nfs/nfs4.h>

#define DNAMEMAX                        (NS_MAXCDNAME + 1)

typedef struct {
        void    *(*fcn)(void *);
        int      signal;
} cb_t;

#ifdef  __LIBMAPID_IMPL

/*
 * Error Messages
 */
#define EMSG_NETDB_INTERNAL     "Internal Resolver Error: %s"

#define EMSG_TRY_AGAIN          "\"%s\" DNS nameserver(s) not responding" \
                                "...\tRetrying"

#define EMSG_NO_RECOVERY        "Unrecoverable Resolver Error: %s"

#define EMSG_HOST_NOT_FOUND     "Authoritative nameserver unresponsive " \
                                "to queries for domain \"%s\""

#define EMSG_NO_DATA            "\"%s\" DNS TXT record not found: "\
                                "Defaulting to \"%s\""

#define EMSG_DNS_THREAD_ERROR   "Unable to create DNS query thread"

#define EMSG_DNS_DISABLE        "%s: Further DNS queries disabled !"

#define EMSG_DNS_RR_INVAL       "\"%s\" Invalid DNS TXT record: "\
                                "Defaulting to \"%s\""

/*
 * DNS related info
 */
#define NFSMAPID_DNS_RR                 "_nfsv4idmapdomain"
#define NFSMAPID_DNS_TOUT_SECS          (30LL)
#define NFSMAPID_SLOG_RATE              20      /* ~10 mins */

#define NS_ERRS                         6       /* netdb.h */

typedef union {
        HEADER  hdr;
        uchar_t buf[PACKETSZ];
} ans_t;

/*
 * NOTE: All s_ prefixed variables are only to be used by the DNS
 *       feature implementation (mapid.c). The exported globals
 *       (ie. seen by nfsmapid.c/nfsmapid_server.c) are the
 *       dns_ prefixed variables along with sysdns_domain.
 */
static ans_t                     s_ans;
static int                       s_anslen;
static char                      s_dname[DNAMEMAX] = {0};
static char                      s_txt_rr[DNAMEMAX] = {0};

static rwlock_t                  s_dns_data_lock = DEFAULTRWLOCK;
static rwlock_t                  s_dns_impl_lock = DEFAULTRWLOCK;
static mutex_t                   s_res_lock = ERRORCHECKMUTEX;
static uint32_t                  s_dns_tout = 0;
static thread_t                  s_dns_qthread;
static bool_t                    s_dns_qthr_created = FALSE;
static bool_t                    s_dns_disabled = FALSE;
static struct __res_state        s_res = {0};
static thread_key_t              s_thr_key;
int                              lib_init_done = 0;

static int                       resolv_init(void);
static void                      resolv_decode(void);
static int                       resolv_error(void);
static void                      resolv_get_txt_data(void);
static void                      resolv_txt_reset(void);
static void                      resolve_process_txt(uchar_t *, int);
static int                       resolv_search(void);
static void                      resolv_destroy(void);
static uchar_t                  *resolv_skip_rr(uchar_t *, uchar_t *);
static void                      domain_sync(cb_t *, char *);
static int                       get_mtime(const char *, timestruc_t *);
static void                      get_nfs_domain(void);
static void                      get_dns_domain(void);
static void                      get_dns_txt_domain(cb_t *);
void                             _lib_init(void);

#ifdef  DEBUG
bool_t                           nfsmapid_debug = FALSE;
#endif  /* DEBUG */

/*
 * mapid_domain_lock:   rwlock used to serialize access/changes
 *                      to the library's mapid_domain global var.
 *
 * mapid_domain:        Library variable used to store the current
 *                      domain configured for use in decoding/encoding
 *                      outbound and inbound attr strings, accordingly.
 *
 * nfs_domain:          If nfsmapid_domain var in SMF
 *                      has been set, nfs_domain will hold this
 *                      value for the duration of the instance;
 *                      If the value ever changes, the change is
 *                      detected via the use of nfs_mtime and
 *                      nfs_domain is updated accordingly.
 *
 * dns_domain:          If the system's resolver (/etc/resolv.conf)
 *                      has been configured, dns_domain will hold
 *                      the configured DNS domain as reported by the
 *                      res_ninit() resolver interface. If the system's
 *                      /etc/resolv.conf file is updated, the change
 *                      is detected via the use of dns_mtime and
 *                      dns_domain is updated accordingly.
 */
rwlock_t                        mapid_domain_lock = DEFAULTRWLOCK;
uint32_t                        mapid_domain_len = 0;
char                            mapid_domain[DNAMEMAX] = {0};

timestruc_t                     nfs_mtime = {0};
uint32_t                        nfs_domain_len = 0;
char                            nfs_domain[DNAMEMAX] = {0};

timestruc_t                     dns_mtime = {0};
uint32_t                        dns_domain_len = 0;
char                            dns_domain[DNAMEMAX] = {0};

int                             dns_txt_cached = 0;
uint32_t                        dns_txt_domain_len = 0;
char                            dns_txt_domain[DNAMEMAX] = {0};
char                            sysdns_domain[DNAMEMAX] = {0};

timestruc_t                     zapped_mtime = {0};

#define ZAP_DOMAIN(which)                       \
        {                                       \
                bzero(which##_domain, DNAMEMAX);\
                which##_domain_len = 0;         \
                which##_mtime = zapped_mtime;   \
        }

#define TIMESTRUC_EQ(a, b)                      \
                (((a).tv_sec == (b).tv_sec) &&  \
                ((a).tv_nsec == (b).tv_nsec))



#endif  /* __LIBMAPID_IMPL */

/*
 * PSARC 2005/487 Consolidation Private Interfaces
 * mapid_reeval_domain(), mapid_get_domain()
 * Changes must be reviewed by Solaris File Sharing
 */
extern void                      mapid_reeval_domain(cb_t *);
extern char                     *mapid_get_domain(void);

/*
 * PSARC 2005/487 Contracted Sun Private Interface
 * mapid_derive_domain(), mapid_stdchk_domain()
 * Changes must be reviewed by Solaris File Sharing
 * Changes must be communicated to contract-2005-487-01@sun.com
 */
extern int                       mapid_stdchk_domain(const char *);
extern char                     *mapid_derive_domain(void);

#ifdef  __cplusplus
}
#endif

#endif  /* _MAPID_H */