/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright  2008 Sun Microsystems, Inc. All rights reserved
 * Use is subject to license terms.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#ifndef EXPORT_SYMTAB
#define EXPORT_SYMTAB
#endif
#define DEBUG_SUBSYSTEM S_SEC

#include <libcfs/libcfs.h>
#ifndef __KERNEL__
#include <liblustre.h>
#include <libcfs/list.h>
#else
#include <linux/crypto.h>
#include <linux/key.h>
#endif

#include <obd.h>
#include <obd_class.h>
#include <obd_support.h>
#include <lustre_net.h>
#include <lustre_import.h>
#include <lustre_log.h>
#include <lustre_disk.h>
#include <lustre_dlm.h>
#include <lustre_param.h>
#include <lustre_sec.h>

#include "ptlrpc_internal.h"

const char *sptlrpc_part2name(enum lustre_sec_part part)
{
        switch (part) {
        case LUSTRE_SP_CLI:
                return "cli";
        case LUSTRE_SP_MDT:
                return "mdt";
        case LUSTRE_SP_OST:
                return "ost";
        case LUSTRE_SP_MGC:
                return "mgc";
        case LUSTRE_SP_MGS:
                return "mgs";
        case LUSTRE_SP_ANY:
                return "any";
        default:
                return "err";
        }
}
EXPORT_SYMBOL(sptlrpc_part2name);

enum lustre_sec_part sptlrpc_target_sec_part(struct obd_device *obd)
{
        const char *type = obd->obd_type->typ_name;

        if (!strcmp(type, LUSTRE_MDT_NAME))
                return LUSTRE_SP_MDT;
        if (!strcmp(type, LUSTRE_OST_NAME))
                return LUSTRE_SP_OST;
        if (!strcmp(type, LUSTRE_MGS_NAME))
                return LUSTRE_SP_MGS;

        CERROR("unknown target %p(%s)\n", obd, type);
        return LUSTRE_SP_ANY;
}
EXPORT_SYMBOL(sptlrpc_target_sec_part);

/****************************************
 * user supplied flavor string parsing  *
 ****************************************/

/*
 * format: <base_flavor>[-<bulk_type:alg_spec>]
 */
int sptlrpc_parse_flavor(const char *str, struct sptlrpc_flavor *flvr)
{
        char            buf[32];
        char           *bulk, *alg;

        memset(flvr, 0, sizeof(*flvr));

        if (str == NULL || str[0] == '\0') {
                flvr->sf_rpc = SPTLRPC_FLVR_INVALID;
                return 0;
        }

        strncpy(buf, str, sizeof(buf));
        buf[sizeof(buf) - 1] = '\0';

        bulk = strchr(buf, '-');
        if (bulk)
                *bulk++ = '\0';

        flvr->sf_rpc = sptlrpc_name2flavor_base(buf);
        if (flvr->sf_rpc == SPTLRPC_FLVR_INVALID)
                goto err_out;

        /*
         * currently only base flavor "plain" can have bulk specification.
         */
        if (flvr->sf_rpc == SPTLRPC_FLVR_PLAIN) {
                flvr->u_bulk.hash.hash_alg = BULK_HASH_ALG_ADLER32;
                if (bulk) {
                        /*
                         * format: plain-hash:<hash_alg>
                         */
                        alg = strchr(bulk, ':');
                        if (alg == NULL)
                                goto err_out;
                        *alg++ = '\0';

                        if (strcmp(bulk, "hash"))
                                goto err_out;

                        flvr->u_bulk.hash.hash_alg = sptlrpc_get_hash_alg(alg);
                        if (flvr->u_bulk.hash.hash_alg >= BULK_HASH_ALG_MAX)
                                goto err_out;
                }

                if (flvr->u_bulk.hash.hash_alg == BULK_HASH_ALG_NULL)
                        flvr_set_bulk_svc(&flvr->sf_rpc, SPTLRPC_BULK_SVC_NULL);
                else
                        flvr_set_bulk_svc(&flvr->sf_rpc, SPTLRPC_BULK_SVC_INTG);
        } else {
                if (bulk)
                        goto err_out;
        }

        flvr->sf_flags = 0;
        return 0;

err_out:
        CERROR("invalid flavor string: %s\n", str);
        return -EINVAL;
}
EXPORT_SYMBOL(sptlrpc_parse_flavor);

/****************************************
 * configure rules                      *
 ****************************************/

static void get_default_flavor(struct sptlrpc_flavor *sf)
{
        memset(sf, 0, sizeof(*sf));

        sf->sf_rpc = SPTLRPC_FLVR_NULL;
        sf->sf_flags = 0;
}

static void sptlrpc_rule_init(struct sptlrpc_rule *rule)
{
        rule->sr_netid = LNET_NIDNET(LNET_NID_ANY);
        rule->sr_from = LUSTRE_SP_ANY;
        rule->sr_to = LUSTRE_SP_ANY;
        rule->sr_padding = 0;

        get_default_flavor(&rule->sr_flvr);
}

/*
 * format: network[.direction]=flavor
 */
int sptlrpc_parse_rule(char *param, struct sptlrpc_rule *rule)
{
        char           *flavor, *dir;
        int             rc;

        sptlrpc_rule_init(rule);

        flavor = strchr(param, '=');
        if (flavor == NULL) {
                CERROR("invalid param, no '='\n");
                RETURN(-EINVAL);
        }
        *flavor++ = '\0';

        dir = strchr(param, '.');
        if (dir)
                *dir++ = '\0';

        /* 1.1 network */
        if (strcmp(param, "default")) {
                rule->sr_netid = libcfs_str2net(param);
                if (rule->sr_netid == LNET_NIDNET(LNET_NID_ANY)) {
                        CERROR("invalid network name: %s\n", param);
                        RETURN(-EINVAL);
                }
        }

        /* 1.2 direction */
        if (dir) {
                if (!strcmp(dir, "mdt2ost")) {
                        rule->sr_from = LUSTRE_SP_MDT;
                        rule->sr_to = LUSTRE_SP_OST;
                } else if (!strcmp(dir, "mdt2mdt")) {
                        rule->sr_from = LUSTRE_SP_MDT;
                        rule->sr_to = LUSTRE_SP_MDT;
                } else if (!strcmp(dir, "cli2ost")) {
                        rule->sr_from = LUSTRE_SP_CLI;
                        rule->sr_to = LUSTRE_SP_OST;
                } else if (!strcmp(dir, "cli2mdt")) {
                        rule->sr_from = LUSTRE_SP_CLI;
                        rule->sr_to = LUSTRE_SP_MDT;
                } else {
                        CERROR("invalid rule dir segment: %s\n", dir);
                        RETURN(-EINVAL);
                }
        }

        /* 2.1 flavor */
        rc = sptlrpc_parse_flavor(flavor, &rule->sr_flvr);
        if (rc)
                RETURN(-EINVAL);

        RETURN(0);
}
EXPORT_SYMBOL(sptlrpc_parse_rule);

void sptlrpc_rule_set_free(struct sptlrpc_rule_set *rset)
{
        LASSERT(rset->srs_nslot ||
                (rset->srs_nrule == 0 && rset->srs_rules == NULL));

        if (rset->srs_nslot) {
                OBD_FREE(rset->srs_rules,
                         rset->srs_nslot * sizeof(*rset->srs_rules));
                sptlrpc_rule_set_init(rset);
        }
}
EXPORT_SYMBOL(sptlrpc_rule_set_free);

/*
 * return 0 if the rule set could accomodate one more rule.
 */
int sptlrpc_rule_set_expand(struct sptlrpc_rule_set *rset)
{
        struct sptlrpc_rule *rules;
        int nslot;

        cfs_might_sleep();

        if (rset->srs_nrule < rset->srs_nslot)
                return 0; 

        nslot = rset->srs_nslot + 8;

        /* better use realloc() if available */
        OBD_ALLOC(rules, nslot * sizeof(*rset->srs_rules));
        if (rules == NULL)
                return -ENOMEM;

        if (rset->srs_nrule) {
                LASSERT(rset->srs_nslot && rset->srs_rules);
                memcpy(rules, rset->srs_rules,
                       rset->srs_nrule * sizeof(*rset->srs_rules));

                OBD_FREE(rset->srs_rules,
                         rset->srs_nslot * sizeof(*rset->srs_rules));
        }

        rset->srs_rules = rules;
        rset->srs_nslot = nslot;
        return 0;
}
EXPORT_SYMBOL(sptlrpc_rule_set_expand);

static inline int rule_spec_dir(struct sptlrpc_rule *rule)
{
        return (rule->sr_from != LUSTRE_SP_ANY ||
                rule->sr_to != LUSTRE_SP_ANY);
}
static inline int rule_spec_net(struct sptlrpc_rule *rule)
{
        return (rule->sr_netid != LNET_NIDNET(LNET_NID_ANY));
}
static inline int rule_match_dir(struct sptlrpc_rule *r1,
                                 struct sptlrpc_rule *r2)
{
        return (r1->sr_from == r2->sr_from && r1->sr_to == r2->sr_to);
}
static inline int rule_match_net(struct sptlrpc_rule *r1,
                                 struct sptlrpc_rule *r2)
{
        return (r1->sr_netid == r2->sr_netid);
}

/*
 * merge @rule into @rset.
 * the @rset slots might be expanded.
 */
int sptlrpc_rule_set_merge(struct sptlrpc_rule_set *rset, 
                           struct sptlrpc_rule *rule)
{
        struct sptlrpc_rule      *p = rset->srs_rules;
        int                       spec_dir, spec_net;
        int                       rc, n, match = 0;

        cfs_might_sleep();

        spec_net = rule_spec_net(rule);
        spec_dir = rule_spec_dir(rule);

        for (n = 0; n < rset->srs_nrule; n++) {
                p = &rset->srs_rules[n]; 

                /* test network match, if failed:
                 * - spec rule: skip rules which is also spec rule match, until
                 *   we hit a wild rule, which means no more chance
                 * - wild rule: skip until reach the one which is also wild
                 *   and matches
                 */
                if (!rule_match_net(p, rule)) {
                        if (spec_net) {
                                if (rule_spec_net(p))
                                        continue;
                                else
                                        break;
                        } else {
                                continue;
                        }
                }

                /* test dir match, same logic as net matching */
                if (!rule_match_dir(p, rule)) {
                        if (spec_dir) {
                                if (rule_spec_dir(p))
                                        continue;
                                else
                                        break;
                        } else {
                                continue;
                        }
                }

                /* find a match */
                match = 1;
                break;
        }

        if (match) {
                LASSERT(n >= 0 && n < rset->srs_nrule);

                if (rule->sr_flvr.sf_rpc == SPTLRPC_FLVR_INVALID) {
                        /* remove this rule */
                        if (n < rset->srs_nrule - 1)
                                memmove(&rset->srs_rules[n],
                                        &rset->srs_rules[n + 1],
                                        (rset->srs_nrule - n - 1) *
                                        sizeof(*rule));
                        rset->srs_nrule--;
                } else {
                        /* override the rule */
                        memcpy(&rset->srs_rules[n], rule, sizeof(*rule));
                }
        } else {
                LASSERT(n >= 0 && n <= rset->srs_nrule);

                if (rule->sr_flvr.sf_rpc != SPTLRPC_FLVR_INVALID) {
                        rc = sptlrpc_rule_set_expand(rset);
                        if (rc)
                                return rc;

                        if (n < rset->srs_nrule)
                                memmove(&rset->srs_rules[n + 1],
                                        &rset->srs_rules[n],
                                        (rset->srs_nrule - n) * sizeof(*rule));
                        memcpy(&rset->srs_rules[n], rule, sizeof(*rule));
                        rset->srs_nrule++;
                } else {
                        CDEBUG(D_CONFIG, "ignore the unmatched deletion\n");
                }
        }

        return 0;
}
EXPORT_SYMBOL(sptlrpc_rule_set_merge);

/**
 * given from/to/nid, determine a matching flavor in ruleset.
 * return 1 if a match found, otherwise return 0.
 */
int sptlrpc_rule_set_choose(struct sptlrpc_rule_set *rset,
                            enum lustre_sec_part from,
                            enum lustre_sec_part to,
                            lnet_nid_t nid,
                            struct sptlrpc_flavor *sf)
{
        struct sptlrpc_rule    *r;
        int                     n;

        for (n = 0; n < rset->srs_nrule; n++) {
                r = &rset->srs_rules[n];

                if (LNET_NIDNET(nid) != LNET_NIDNET(LNET_NID_ANY) &&
                    r->sr_netid != LNET_NIDNET(LNET_NID_ANY) &&
                    LNET_NIDNET(nid) != r->sr_netid)
                        continue;

                if (from != LUSTRE_SP_ANY && r->sr_from != LUSTRE_SP_ANY &&
                    from != r->sr_from)
                        continue;

                if (to != LUSTRE_SP_ANY && r->sr_to != LUSTRE_SP_ANY &&
                    to != r->sr_to)
                        continue;

                *sf = r->sr_flvr;
                return 1;
        }

        return 0;
}
EXPORT_SYMBOL(sptlrpc_rule_set_choose);

void sptlrpc_rule_set_dump(struct sptlrpc_rule_set *rset)
{
        struct sptlrpc_rule *r;
        int     n;

        for (n = 0; n < rset->srs_nrule; n++) {
                r = &rset->srs_rules[n];
                CWARN("<%02d> from %x to %x, net %x, rpc %x\n", n,
                      r->sr_from, r->sr_to, r->sr_netid, r->sr_flvr.sf_rpc);
        }
}
EXPORT_SYMBOL(sptlrpc_rule_set_dump);

static int sptlrpc_rule_set_extract(struct sptlrpc_rule_set *gen,
                                    struct sptlrpc_rule_set *tgt,
                                    enum lustre_sec_part from,
                                    enum lustre_sec_part to,
                                    struct sptlrpc_rule_set *rset)
{
        struct sptlrpc_rule_set *src[2] = { gen, tgt };
        struct sptlrpc_rule     *rule;
        int                      i, n, rc;

        cfs_might_sleep();

        /* merge general rules firstly, then target-specific rules */
        for (i = 0; i < 2; i++) {
                if (src[i] == NULL)
                        continue;

                for (n = 0; n < src[i]->srs_nrule; n++) {
                        rule = &src[i]->srs_rules[n];

                        if (from != LUSTRE_SP_ANY &&
                            rule->sr_from != LUSTRE_SP_ANY &&
                            rule->sr_from != from)
                                continue;
                        if (to != LUSTRE_SP_ANY &&
                            rule->sr_to != LUSTRE_SP_ANY &&
                            rule->sr_to != to)
                                continue;

                        rc = sptlrpc_rule_set_merge(rset, rule);
                        if (rc) {
                                CERROR("can't merge: %d\n", rc);
                                return rc;
                        }
                }
        }

        return 0;
}

/**********************************
 * sptlrpc configuration support  *
 **********************************/

struct sptlrpc_conf_tgt {
        cfs_list_t              sct_list;
        char                    sct_name[MAX_OBD_NAME];
        struct sptlrpc_rule_set sct_rset;
};

struct sptlrpc_conf {
        cfs_list_t              sc_list;
        char                    sc_fsname[MTI_NAME_MAXLEN];
        unsigned int            sc_modified;  /* modified during updating */
        unsigned int            sc_updated:1, /* updated copy from MGS */
                                sc_local:1;   /* local copy from target */
        struct sptlrpc_rule_set sc_rset;      /* fs general rules */
        cfs_list_t              sc_tgts;      /* target-specific rules */
};

static cfs_mutex_t sptlrpc_conf_lock;
static CFS_LIST_HEAD(sptlrpc_confs);

static inline int is_hex(char c)
{
        return ((c >= '0' && c <= '9') ||
                (c >= 'a' && c <= 'f'));
}

static void target2fsname(const char *tgt, char *fsname, int buflen)
{
        const char     *ptr;
        int             len;

        ptr = strrchr(tgt, '-');
        if (ptr) {
                if ((strncmp(ptr, "-MDT", 4) != 0 &&
                     strncmp(ptr, "-OST", 4) != 0) ||
                    !is_hex(ptr[4]) || !is_hex(ptr[5]) ||
                    !is_hex(ptr[6]) || !is_hex(ptr[7]))
                        ptr = NULL;
        }

        /* if we didn't find the pattern, treat the whole string as fsname */
        if (ptr == NULL)
                len = strlen(tgt);
        else
                len = ptr - tgt;

        len = min(len, buflen - 1);
        memcpy(fsname, tgt, len);
        fsname[len] = '\0';
}

static void sptlrpc_conf_free_rsets(struct sptlrpc_conf *conf)
{
        struct sptlrpc_conf_tgt *conf_tgt, *conf_tgt_next;

        sptlrpc_rule_set_free(&conf->sc_rset);

        cfs_list_for_each_entry_safe(conf_tgt, conf_tgt_next,
                                     &conf->sc_tgts, sct_list) {
                sptlrpc_rule_set_free(&conf_tgt->sct_rset);
                cfs_list_del(&conf_tgt->sct_list);
                OBD_FREE_PTR(conf_tgt);
        }
        LASSERT(cfs_list_empty(&conf->sc_tgts));

        conf->sc_updated = 0;
        conf->sc_local = 0;
}

static void sptlrpc_conf_free(struct sptlrpc_conf *conf)
{
        CDEBUG(D_SEC, "free sptlrpc conf %s\n", conf->sc_fsname);

        sptlrpc_conf_free_rsets(conf);
        cfs_list_del(&conf->sc_list);
        OBD_FREE_PTR(conf);
}

static
struct sptlrpc_conf_tgt *sptlrpc_conf_get_tgt(struct sptlrpc_conf *conf,
                                              const char *name,
                                              int create)
{
        struct sptlrpc_conf_tgt *conf_tgt;

        cfs_list_for_each_entry(conf_tgt, &conf->sc_tgts, sct_list) {
                if (strcmp(conf_tgt->sct_name, name) == 0)
                        return conf_tgt;
        }

        if (!create)
                return NULL;

        OBD_ALLOC_PTR(conf_tgt);
        if (conf_tgt) {
                strncpy(conf_tgt->sct_name, name, sizeof(conf_tgt->sct_name));
                sptlrpc_rule_set_init(&conf_tgt->sct_rset);
                cfs_list_add(&conf_tgt->sct_list, &conf->sc_tgts);
        }

        return conf_tgt;
}

static
struct sptlrpc_conf *sptlrpc_conf_get(const char *fsname,
                                      int create)
{
        struct sptlrpc_conf *conf;

        cfs_list_for_each_entry(conf, &sptlrpc_confs, sc_list) {
                if (strcmp(conf->sc_fsname, fsname) == 0)
                        return conf;
        }

        if (!create)
                return NULL;

        OBD_ALLOC_PTR(conf);
        if (conf == NULL)
                return NULL;

        strcpy(conf->sc_fsname, fsname);
        sptlrpc_rule_set_init(&conf->sc_rset);
        CFS_INIT_LIST_HEAD(&conf->sc_tgts);
        cfs_list_add(&conf->sc_list, &sptlrpc_confs);

        CDEBUG(D_SEC, "create sptlrpc conf %s\n", conf->sc_fsname);
        return conf;
}

/**
 * caller must hold conf_lock already.
 */
static int sptlrpc_conf_merge_rule(struct sptlrpc_conf *conf,
                                   const char *target,
                                   struct sptlrpc_rule *rule)
{
        struct sptlrpc_conf_tgt  *conf_tgt;
        struct sptlrpc_rule_set  *rule_set;

        /* fsname == target means general rules for the whole fs */
        if (strcmp(conf->sc_fsname, target) == 0) {
                rule_set = &conf->sc_rset;
        } else {
                conf_tgt = sptlrpc_conf_get_tgt(conf, target, 1);
                if (conf_tgt) {
                        rule_set = &conf_tgt->sct_rset;
                } else {
                        CERROR("out of memory, can't merge rule!\n");
                        return -ENOMEM;
                }
        }

        return sptlrpc_rule_set_merge(rule_set, rule);
}

/**
 * process one LCFG_SPTLRPC_CONF record. if \a conf is NULL, we
 * find one through the target name in the record inside conf_lock;
 * otherwise means caller already hold conf_lock.
 */
static int __sptlrpc_process_config(struct lustre_cfg *lcfg,
                                    struct sptlrpc_conf *conf)
{
        char                   *target, *param;
        char                    fsname[MTI_NAME_MAXLEN];
        struct sptlrpc_rule     rule;
        int                     rc;
        ENTRY;

        target = lustre_cfg_string(lcfg, 1);
        if (target == NULL) {
                CERROR("missing target name\n");
                RETURN(-EINVAL);
        }

        param = lustre_cfg_string(lcfg, 2);
        if (param == NULL) {
                CERROR("missing parameter\n");
                RETURN(-EINVAL);
        }

        CDEBUG(D_SEC, "processing rule: %s.%s\n", target, param);

        /* parse rule to make sure the format is correct */
        if (strncmp(param, PARAM_SRPC_FLVR, sizeof(PARAM_SRPC_FLVR) - 1) != 0) {
                CERROR("Invalid sptlrpc parameter: %s\n", param);
                RETURN(-EINVAL);
        }
        param += sizeof(PARAM_SRPC_FLVR) - 1;

        rc = sptlrpc_parse_rule(param, &rule);
        if (rc)
                RETURN(-EINVAL);

        if (conf == NULL) {
                target2fsname(target, fsname, sizeof(fsname));

                cfs_mutex_lock(&sptlrpc_conf_lock);
                conf = sptlrpc_conf_get(fsname, 0);
                if (conf == NULL) {
                        CERROR("can't find conf\n");
                        rc = -ENOMEM;
                } else {
                        rc = sptlrpc_conf_merge_rule(conf, target, &rule);
                }
                cfs_mutex_unlock(&sptlrpc_conf_lock);
        } else {
                LASSERT(cfs_mutex_is_locked(&sptlrpc_conf_lock));
                rc = sptlrpc_conf_merge_rule(conf, target, &rule);
        }

        if (rc == 0)
                conf->sc_modified++;

        RETURN(rc);
}

int sptlrpc_process_config(struct lustre_cfg *lcfg)
{
        return __sptlrpc_process_config(lcfg, NULL);
}
EXPORT_SYMBOL(sptlrpc_process_config);

static int logname2fsname(const char *logname, char *buf, int buflen)
{
        char   *ptr;
        int     len;

        ptr = strrchr(logname, '-');
        if (ptr == NULL || strcmp(ptr, "-sptlrpc")) {
                CERROR("%s is not a sptlrpc config log\n", logname);
                return -EINVAL;
        }

        len = min((int) (ptr - logname), buflen - 1);

        memcpy(buf, logname, len);
        buf[len] = '\0';
        return 0;
}

void sptlrpc_conf_log_update_begin(const char *logname)
{
        struct sptlrpc_conf *conf;
        char                 fsname[16];

        if (logname2fsname(logname, fsname, sizeof(fsname)))
                return;

        cfs_mutex_lock(&sptlrpc_conf_lock);

        conf = sptlrpc_conf_get(fsname, 0);
        if (conf && conf->sc_local) {
                LASSERT(conf->sc_updated == 0);
                sptlrpc_conf_free_rsets(conf);
        }
        conf->sc_modified = 0;

        cfs_mutex_unlock(&sptlrpc_conf_lock);
}
EXPORT_SYMBOL(sptlrpc_conf_log_update_begin);

/**
 * mark a config log has been updated
 */
void sptlrpc_conf_log_update_end(const char *logname)
{
        struct sptlrpc_conf *conf;
        char                 fsname[16];

        if (logname2fsname(logname, fsname, sizeof(fsname)))
                return;

        cfs_mutex_lock(&sptlrpc_conf_lock);

        conf = sptlrpc_conf_get(fsname, 0);
        if (conf) {
                /*
                 * if original state is not updated, make sure the
                 * modified counter > 0 to enforce updating local copy.
                 */
                if (conf->sc_updated == 0)
                        conf->sc_modified++;

                conf->sc_updated = 1;
        }

        cfs_mutex_unlock(&sptlrpc_conf_lock);
}
EXPORT_SYMBOL(sptlrpc_conf_log_update_end);

void sptlrpc_conf_log_start(const char *logname)
{
        struct sptlrpc_conf *conf;
        char                 fsname[16];

        if (logname2fsname(logname, fsname, sizeof(fsname)))
                return;

        cfs_mutex_lock(&sptlrpc_conf_lock);
        conf = sptlrpc_conf_get(fsname, 1);
        cfs_mutex_unlock(&sptlrpc_conf_lock);
}
EXPORT_SYMBOL(sptlrpc_conf_log_start);

void sptlrpc_conf_log_stop(const char *logname)
{
        struct sptlrpc_conf *conf;
        char                 fsname[16];

        if (logname2fsname(logname, fsname, sizeof(fsname)))
                return;

        cfs_mutex_lock(&sptlrpc_conf_lock);
        conf = sptlrpc_conf_get(fsname, 0);
        if (conf)
                sptlrpc_conf_free(conf);
        cfs_mutex_unlock(&sptlrpc_conf_lock);
}
EXPORT_SYMBOL(sptlrpc_conf_log_stop);

static void inline flavor_set_flags(struct sptlrpc_flavor *sf,
                                    enum lustre_sec_part from,
                                    enum lustre_sec_part to,
                                    unsigned int fl_udesc)
{
        /*
         * null flavor doesn't need to set any flavor, and in fact
         * we'd better not do that because everybody share a single sec.
         */
        if (sf->sf_rpc == SPTLRPC_FLVR_NULL)
                return;

        if (from == LUSTRE_SP_MDT) {
                /* MDT->MDT; MDT->OST */
                sf->sf_flags |= PTLRPC_SEC_FL_ROOTONLY;
        } else if (from == LUSTRE_SP_CLI && to == LUSTRE_SP_OST) {
                /* CLI->OST */
                sf->sf_flags |= PTLRPC_SEC_FL_ROOTONLY | PTLRPC_SEC_FL_BULK;
        } else if (from == LUSTRE_SP_CLI && to == LUSTRE_SP_MDT) {
                /* CLI->MDT */
                if (fl_udesc && sf->sf_rpc != SPTLRPC_FLVR_NULL)
                        sf->sf_flags |= PTLRPC_SEC_FL_UDESC;
        }
}

void sptlrpc_conf_choose_flavor(enum lustre_sec_part from,
                                enum lustre_sec_part to,
                                struct obd_uuid *target,
                                lnet_nid_t nid,
                                struct sptlrpc_flavor *sf)
{
        struct sptlrpc_conf     *conf;
        struct sptlrpc_conf_tgt *conf_tgt;
        char                     name[MTI_NAME_MAXLEN];
        int                      len, rc = 0;

        target2fsname(target->uuid, name, sizeof(name));

        cfs_mutex_lock(&sptlrpc_conf_lock);

        conf = sptlrpc_conf_get(name, 0);
        if (conf == NULL)
                goto out;

        /* convert uuid name (supposed end with _UUID) to target name */
        len = strlen(target->uuid);
        LASSERT(len > 5);
        memcpy(name, target->uuid, len - 5);
        name[len - 5] = '\0';

        conf_tgt = sptlrpc_conf_get_tgt(conf, name, 0);
        if (conf_tgt) {
                rc = sptlrpc_rule_set_choose(&conf_tgt->sct_rset,
                                             from, to, nid, sf);
                if (rc)
                        goto out;
        }

        rc = sptlrpc_rule_set_choose(&conf->sc_rset, from, to, nid, sf);
out:
        cfs_mutex_unlock(&sptlrpc_conf_lock);

        if (rc == 0)
                get_default_flavor(sf);

        flavor_set_flags(sf, from, to, 1);
}

/**
 * called by target devices, determine the expected flavor from
 * certain peer (from, nid).
 */
void sptlrpc_target_choose_flavor(struct sptlrpc_rule_set *rset,
                                  enum lustre_sec_part from,
                                  lnet_nid_t nid,
                                  struct sptlrpc_flavor *sf)
{
        if (sptlrpc_rule_set_choose(rset, from, LUSTRE_SP_ANY, nid, sf) == 0)
                get_default_flavor(sf);
}
EXPORT_SYMBOL(sptlrpc_target_choose_flavor);

#define SEC_ADAPT_DELAY         (10)

/**
 * called by client devices, notify the sptlrpc config has changed and
 * do import_sec_adapt later.
 */
void sptlrpc_conf_client_adapt(struct obd_device *obd)
{
        struct obd_import  *imp;
        ENTRY;

        LASSERT(strcmp(obd->obd_type->typ_name, LUSTRE_MDC_NAME) == 0 ||
                strcmp(obd->obd_type->typ_name, LUSTRE_OSC_NAME) ==0);
        CDEBUG(D_SEC, "obd %s\n", obd->u.cli.cl_target_uuid.uuid);

        /* serialize with connect/disconnect import */
        cfs_down_read(&obd->u.cli.cl_sem);

        imp = obd->u.cli.cl_import;
        if (imp) {
                cfs_spin_lock(&imp->imp_lock);
                if (imp->imp_sec)
                        imp->imp_sec_expire = cfs_time_current_sec() +
                                              SEC_ADAPT_DELAY;
                cfs_spin_unlock(&imp->imp_lock);
        }

        cfs_up_read(&obd->u.cli.cl_sem);
        EXIT;
}
EXPORT_SYMBOL(sptlrpc_conf_client_adapt);

#ifdef __KERNEL__

static void rule2string(struct sptlrpc_rule *r, char *buf, int buflen)
{
        char    dirbuf[8];
        char   *net;
        char   *ptr = buf;

        if (r->sr_netid == LNET_NIDNET(LNET_NID_ANY))
                net = "default";
        else
                net = libcfs_net2str(r->sr_netid);

        if (r->sr_from == LUSTRE_SP_ANY && r->sr_to == LUSTRE_SP_ANY)
                dirbuf[0] = '\0';
        else
                snprintf(dirbuf, sizeof(dirbuf), ".%s2%s",
                         sptlrpc_part2name(r->sr_from),
                         sptlrpc_part2name(r->sr_to));

        ptr += snprintf(buf, buflen, "srpc.flavor.%s%s=", net, dirbuf);

        sptlrpc_flavor2name(&r->sr_flvr, ptr, buflen - (ptr - buf));
        buf[buflen - 1] = '\0';
}

static int sptlrpc_record_rule_set(struct llog_handle *llh,
                                   char *target,
                                   struct sptlrpc_rule_set *rset)
{
        struct lustre_cfg_bufs  bufs;
        struct lustre_cfg      *lcfg;
        struct llog_rec_hdr     rec;
        int                     buflen;
        char                    param[48];
        int                     i, rc;

        for (i = 0; i < rset->srs_nrule; i++) {
                rule2string(&rset->srs_rules[i], param, sizeof(param));

                lustre_cfg_bufs_reset(&bufs, NULL);
                lustre_cfg_bufs_set_string(&bufs, 1, target);
                lustre_cfg_bufs_set_string(&bufs, 2, param);
                lcfg = lustre_cfg_new(LCFG_SPTLRPC_CONF, &bufs);
                LASSERT(lcfg);

                buflen = lustre_cfg_len(lcfg->lcfg_bufcount,
                                        lcfg->lcfg_buflens);
                rec.lrh_len = llog_data_len(buflen);
                rec.lrh_type = OBD_CFG_REC;
                rc = llog_write_rec(llh, &rec, NULL, 0, (void *)lcfg, -1);
                if (rc)
                        CERROR("failed to write a rec: rc = %d\n", rc);
                lustre_cfg_free(lcfg);
        }
        return 0;
}

static int sptlrpc_record_rules(struct llog_handle *llh,
                                struct sptlrpc_conf *conf)
{
        struct sptlrpc_conf_tgt *conf_tgt;

        sptlrpc_record_rule_set(llh, conf->sc_fsname, &conf->sc_rset);

        cfs_list_for_each_entry(conf_tgt, &conf->sc_tgts, sct_list) {
                sptlrpc_record_rule_set(llh, conf_tgt->sct_name,
                                        &conf_tgt->sct_rset);
        }
        return 0;
}

#define LOG_SPTLRPC_TMP "sptlrpc.tmp"
#define LOG_SPTLRPC     "sptlrpc"

static
int sptlrpc_target_local_copy_conf(struct obd_device *obd,
                                   struct sptlrpc_conf *conf)
{
        struct llog_handle   *llh = NULL;
        struct llog_ctxt     *ctxt;
        struct lvfs_run_ctxt  saved;
        struct dentry        *dentry;
        int                   rc;
        ENTRY;

        ctxt = llog_get_context(obd, LLOG_CONFIG_ORIG_CTXT);
        if (ctxt == NULL) {
                CERROR("missing llog context\n");
                RETURN(-EINVAL);
        }

        push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);

        dentry = lookup_one_len(MOUNT_CONFIGS_DIR, cfs_fs_pwd(current->fs),
                                strlen(MOUNT_CONFIGS_DIR));
        if (IS_ERR(dentry)) {
                rc = PTR_ERR(dentry);
                CERROR("cannot lookup %s directory: rc = %d\n",
                       MOUNT_CONFIGS_DIR, rc);
                GOTO(out_ctx, rc);
        }

        /* erase the old tmp log */
        rc = llog_create(ctxt, &llh, NULL, LOG_SPTLRPC_TMP);
        if (rc == 0) {
                rc = llog_init_handle(llh, LLOG_F_IS_PLAIN, NULL);
                if (rc == 0) {
                        rc = llog_destroy(llh);
                        llog_free_handle(llh);
                } else {
                        llog_close(llh);
                }
        }

        if (rc) {
                CERROR("target %s: cannot erase temporary sptlrpc log: "
                       "rc = %d\n", obd->obd_name, rc);
                GOTO(out_dput, rc);
        }

        /* write temporary log */
        rc = llog_create(ctxt, &llh, NULL, LOG_SPTLRPC_TMP);
        if (rc)
                GOTO(out_dput, rc);
        rc = llog_init_handle(llh, LLOG_F_IS_PLAIN, NULL);
        if (rc)
                GOTO(out_close, rc);

        rc = sptlrpc_record_rules(llh, conf);

out_close:
        llog_close(llh);

        if (rc == 0) {
                rc = lustre_rename(dentry, obd->obd_lvfs_ctxt.pwdmnt,
                                   LOG_SPTLRPC_TMP, LOG_SPTLRPC);
        }

out_dput:
        l_dput(dentry);
out_ctx:
        pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
        llog_ctxt_put(ctxt);
        CDEBUG(D_SEC, "target %s: write local sptlrpc conf: rc = %d\n",
               obd->obd_name, rc);
        RETURN(rc);
}

static int local_read_handler(struct llog_handle *llh,
                              struct llog_rec_hdr *rec,
                              void *data)
{
        struct sptlrpc_conf  *conf = (struct sptlrpc_conf *) data;
        struct lustre_cfg    *lcfg = (struct lustre_cfg *)(rec + 1);
        int                   cfg_len, rc;
        ENTRY;

        if (rec->lrh_type != OBD_CFG_REC) {
                CERROR("unhandled lrh_type: %#x\n", rec->lrh_type);
                RETURN(-EINVAL);
        }

        cfg_len = rec->lrh_len - sizeof(struct llog_rec_hdr) -
                  sizeof(struct llog_rec_tail);

        rc = lustre_cfg_sanity_check(lcfg, cfg_len);
        if (rc) {
                CERROR("Insane cfg\n");
                RETURN(rc);
        }

        if (lcfg->lcfg_command != LCFG_SPTLRPC_CONF) {
                CERROR("invalid command (%x)\n", lcfg->lcfg_command);
                RETURN(-EINVAL);
        }

        RETURN(__sptlrpc_process_config(lcfg, conf));
}

static
int sptlrpc_target_local_read_conf(struct obd_device *obd,
                                   struct sptlrpc_conf *conf)
{
        struct llog_handle    *llh = NULL;
        struct llog_ctxt      *ctxt;
        struct lvfs_run_ctxt   saved;
        int                    rc;
        ENTRY;

        LASSERT(conf->sc_updated == 0 && conf->sc_local == 0);

        ctxt = llog_get_context(obd, LLOG_CONFIG_ORIG_CTXT);
        if (ctxt == NULL) {
                CERROR("missing llog context\n");
                RETURN(-EINVAL);
        }

        push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);

        rc = llog_create(ctxt, &llh, NULL, LOG_SPTLRPC);
        if (rc)
                GOTO(out_pop, rc);

        rc = llog_init_handle(llh, LLOG_F_IS_PLAIN, NULL);
        if (rc)
                GOTO(out_close, rc);

        if (llog_get_size(llh) <= 1) {
                CDEBUG(D_SEC, "no local sptlrpc copy found\n");
                GOTO(out_close, rc = 0);
        }

        rc = llog_process(llh, local_read_handler, (void *) conf, NULL);

        if (rc == 0) {
                conf->sc_local = 1;
        } else {
                sptlrpc_conf_free_rsets(conf);
        }

out_close:
        llog_close(llh);
out_pop:
        pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
        llog_ctxt_put(ctxt);
        CDEBUG(D_SEC, "target %s: read local sptlrpc conf: rc = %d\n",
               obd->obd_name, rc);
        RETURN(rc);
}

#endif /* __KRENEL__ */

/**
 * called by target devices, extract sptlrpc rules which applies to
 * this target, to be used for future rpc flavor checking.
 */
int sptlrpc_conf_target_get_rules(struct obd_device *obd,
                                  struct sptlrpc_rule_set *rset,
                                  int initial)
{
        struct sptlrpc_conf      *conf;
        struct sptlrpc_conf_tgt  *conf_tgt;
        enum lustre_sec_part      sp_dst;
        char                      fsname[MTI_NAME_MAXLEN];
        int                       rc = 0;
        ENTRY;

        if (strcmp(obd->obd_type->typ_name, LUSTRE_MDT_NAME) == 0) {
                sp_dst = LUSTRE_SP_MDT;
        } else if (strcmp(obd->obd_type->typ_name, LUSTRE_OST_NAME) == 0) {
                sp_dst = LUSTRE_SP_OST;
        } else {
                CERROR("unexpected obd type %s\n", obd->obd_type->typ_name);
                RETURN(-EINVAL);
        }
        CDEBUG(D_SEC, "get rules for target %s\n", obd->obd_uuid.uuid);

        target2fsname(obd->obd_uuid.uuid, fsname, sizeof(fsname));

        cfs_mutex_lock(&sptlrpc_conf_lock);

        conf = sptlrpc_conf_get(fsname, 0);
        if (conf == NULL) {
                CERROR("missing sptlrpc config log\n");
                GOTO(out, rc);
        }

#ifdef __KERNEL__
        if (conf->sc_updated  == 0) {
                /*
                 * always read from local copy. here another option is
                 * if we already have a local copy (read from another
                 * target device hosted on the same node) we simply use that.
                 */
                if (conf->sc_local)
                        sptlrpc_conf_free_rsets(conf);

                sptlrpc_target_local_read_conf(obd, conf);
        } else {
                LASSERT(conf->sc_local == 0);

                /* write a local copy */
                if (initial || conf->sc_modified)
                        sptlrpc_target_local_copy_conf(obd, conf);
                else
                        CDEBUG(D_SEC, "unchanged, skip updating local copy\n");
        }
#endif

        /* extract rule set for this target */
        conf_tgt = sptlrpc_conf_get_tgt(conf, obd->obd_name, 0);

        rc = sptlrpc_rule_set_extract(&conf->sc_rset,
                                      conf_tgt ? &conf_tgt->sct_rset: NULL,
                                      LUSTRE_SP_ANY, sp_dst, rset);
out:
        cfs_mutex_unlock(&sptlrpc_conf_lock);
        RETURN(rc);
}
EXPORT_SYMBOL(sptlrpc_conf_target_get_rules);

int  sptlrpc_conf_init(void)
{
        cfs_mutex_init(&sptlrpc_conf_lock);
        return 0;
}

void sptlrpc_conf_fini(void)
{
        struct sptlrpc_conf  *conf, *conf_next;

        cfs_mutex_lock(&sptlrpc_conf_lock);
        cfs_list_for_each_entry_safe(conf, conf_next, &sptlrpc_confs, sc_list) {
                sptlrpc_conf_free(conf);
        }
        LASSERT(cfs_list_empty(&sptlrpc_confs));
        cfs_mutex_unlock(&sptlrpc_conf_lock);
}