/*
    SSSD

    Async LDAP Helper routines - retrieving users

    Copyright (C) Simo Sorce <ssorce@redhat.com> - 2009
    Copyright (C) 2010, Ralf Haferkamp <rhafer@suse.de>, Novell Inc.
    Copyright (C) Jan Zeleny <jzeleny@redhat.com> - 2011

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    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 for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "util/util.h"
#include "db/sysdb.h"
#include "providers/ldap/sdap_async_private.h"
#include "providers/ldap/ldap_common.h"
#include "providers/ldap/sdap_idmap.h"

/* ==Save-User-Entry====================================================== */

/* FIXME: support storing additional attributes */
int sdap_save_user(TALLOC_CTX *memctx,
                   struct sysdb_ctx *ctx,
                   struct sdap_options *opts,
                   struct sss_domain_info *dom,
                   struct sysdb_attrs *attrs,
                   bool is_initgr,
                   char **_usn_value,
                   time_t now)
{
    struct ldb_message_element *el;
    int ret;
    const char *name = NULL;
    const char *fullname = NULL;
    const char *pwd;
    const char *gecos;
    const char *homedir;
    const char *shell;
    const char *orig_dn = NULL;
    uid_t uid;
    gid_t gid, primary_gid;
    struct sysdb_attrs *user_attrs;
    char *upn = NULL;
    size_t i;
    int cache_timeout;
    char *usn_value = NULL;
    char **missing = NULL;
    TALLOC_CTX *tmpctx = NULL;
    bool use_id_mapping = dp_opt_get_bool(opts->basic, SDAP_ID_MAPPING);
    char *sid_str;
    char *dom_sid_str = NULL;
    char *group_sid_str;

    DEBUG(9, ("Save user\n"));

    tmpctx = talloc_new(NULL);
    if (!tmpctx) {
        ret = ENOMEM;
        goto fail;
    }

    user_attrs = sysdb_new_attrs(tmpctx);
    if (user_attrs == NULL) {
        ret = ENOMEM;
        goto fail;
    }

    ret = sysdb_attrs_primary_name(ctx, attrs,
                                   opts->user_map[SDAP_AT_USER_NAME].name,
                                   &name);
    if (ret != EOK) {
        DEBUG(1, ("Failed to save the user - entry has no name attribute\n"));
        goto fail;
    }

    if (opts->schema_type == SDAP_SCHEMA_AD) {
        ret = sysdb_attrs_get_string(attrs,
                    opts->user_map[SDAP_AT_USER_FULLNAME].sys_name, &fullname);
        if (ret == EOK) {
            ret = sysdb_attrs_add_string(user_attrs, SYSDB_FULLNAME, fullname);
            if (ret != EOK) {
                goto fail;
            }
        } else if (ret != ENOENT) {
            goto fail;
        }
    }

    ret = sysdb_attrs_get_el(attrs,
                             opts->user_map[SDAP_AT_USER_PWD].sys_name, &el);
    if (ret) goto fail;
    if (el->num_values == 0) pwd = NULL;
    else pwd = (const char *)el->values[0].data;

    ret = sysdb_attrs_get_el(attrs,
                             opts->user_map[SDAP_AT_USER_GECOS].sys_name, &el);
    if (ret) goto fail;
    if (el->num_values == 0) gecos = NULL;
    else gecos = (const char *)el->values[0].data;

    if (!gecos) {
        /* Fall back to the user's full name */
        ret = sysdb_attrs_get_el(
                attrs,
                opts->user_map[SDAP_AT_USER_FULLNAME].sys_name, &el);
        if (ret) goto fail;
        if (el->num_values > 0) gecos = (const char *)el->values[0].data;
    }

    ret = sysdb_attrs_get_el(attrs,
                             opts->user_map[SDAP_AT_USER_HOME].sys_name, &el);
    if (ret) goto fail;
    if (el->num_values == 0) homedir = NULL;
    else homedir = (const char *)el->values[0].data;

    ret = sysdb_attrs_get_el(attrs,
                             opts->user_map[SDAP_AT_USER_SHELL].sys_name, &el);
    if (ret) goto fail;
    if (el->num_values == 0) shell = NULL;
    else shell = (const char *)el->values[0].data;

    /* Retrieve or map the UID as appropriate */
    if (use_id_mapping) {
        DEBUG(SSSDBG_TRACE_LIBS,
              ("Mapping user [%s] objectSID to unix ID\n", name));

        ret = sdap_attrs_get_sid_str(
                tmpctx, opts->idmap_ctx, attrs,
                opts->user_map[SDAP_AT_USER_OBJECTSID].sys_name,
                &sid_str);
        if (ret != EOK) goto fail;

        /* Add string representation to the cache for easier
         * debugging
         */
        ret = sysdb_attrs_add_string(user_attrs, SYSDB_SID_STR, sid_str);
        if (ret != EOK) goto fail;

        /* Convert the SID into a UNIX user ID */
        ret = sdap_idmap_sid_to_unix(opts->idmap_ctx, sid_str, &uid);
        if (ret != EOK) goto fail;

        /* Store the UID in the ldap_attrs so it doesn't get
         * treated as a missing attribute from LDAP and removed.
         */
        ret = sysdb_attrs_add_uint32(attrs, SYSDB_UIDNUM, uid);
        if (ret != EOK) goto fail;
    } else {
        ret = sysdb_attrs_get_uint32_t(attrs,
                                       opts->user_map[SDAP_AT_USER_UID].sys_name,
                                       &uid);
        if (ret != EOK) {
            DEBUG(1, ("no uid provided for [%s] in domain [%s].\n",
                      name, dom->name));
            ret = EINVAL;
            goto fail;
        }
    }
    /* check that the uid is valid for this domain */
    if (OUT_OF_ID_RANGE(uid, dom->id_min, dom->id_max)) {
            DEBUG(2, ("User [%s] filtered out! (uid out of range)\n",
                      name));
        ret = EINVAL;
        goto fail;
    }

    if (use_id_mapping) {
        ret = sysdb_attrs_get_uint32_t(
                attrs,
                opts->user_map[SDAP_AT_USER_PRIMARY_GROUP].sys_name,
                &primary_gid);
        if (ret != EOK) {
            DEBUG(SSSDBG_MINOR_FAILURE,
                  ("no primary group ID provided for [%s] in domain [%s].\n",
                   name, dom->name));
            ret = EINVAL;
            goto fail;
        }

        /* The primary group ID is just the RID part of the objectSID
         * of the group. Generate the GID by adding this to the domain
         * SID value.
         */

        /* First, get the domain SID if we didn't do so above */
        if (!dom_sid_str) {
            ret = sdap_idmap_get_dom_sid_from_object(tmpctx, sid_str,
                                                     &dom_sid_str);
            if (ret != EOK) {
                DEBUG(SSSDBG_MINOR_FAILURE,
                      ("Could not parse domain SID from [%s]\n", sid_str));
                goto fail;
            }
        }

        /* Add the RID to the end */
        group_sid_str = talloc_asprintf(tmpctx, "%s-%lu",
                                        dom_sid_str,
                                        (unsigned long)primary_gid);
        if (!group_sid_str) {
            ret = ENOMEM;
            goto fail;
        }

        /* Convert the SID into a UNIX group ID */
        ret = sdap_idmap_sid_to_unix(opts->idmap_ctx, group_sid_str, &gid);
        if (ret != EOK) goto fail;

        /* Store the GID in the ldap_attrs so it doesn't get
         * treated as a missing attribute from LDAP and removed.
         */
        ret = sysdb_attrs_add_uint32(attrs, SYSDB_GIDNUM, gid);
        if (ret != EOK) goto fail;
    } else {
        ret = sysdb_attrs_get_uint32_t(attrs,
                                       opts->user_map[SDAP_AT_USER_GID].sys_name,
                                       &gid);
        if (ret != EOK) {
            DEBUG(1, ("no gid provided for [%s] in domain [%s].\n",
                      name, dom->name));
            ret = EINVAL;
            goto fail;
        }
    }

    /* check that the gid is valid for this domain */
    if (OUT_OF_ID_RANGE(gid, dom->id_min, dom->id_max)) {
            DEBUG(2, ("User [%s] filtered out! (primary gid out of range)\n",
                      name));
        ret = EINVAL;
        goto fail;
    }

    ret = sysdb_attrs_get_el(attrs, SYSDB_ORIG_DN, &el);
    if (ret) {
        goto fail;
    }
    if (!el || el->num_values == 0) {
        DEBUG(SSSDBG_MINOR_FAILURE,
              ("originalDN is not available for [%s].\n", name));
    } else {
        orig_dn = (const char *) el->values[0].data;
        DEBUG(SSSDBG_TRACE_INTERNAL, ("Adding originalDN [%s] to attributes "
                "of [%s].\n", orig_dn, name));

        ret = sysdb_attrs_add_string(user_attrs, SYSDB_ORIG_DN, orig_dn);
        if (ret) {
            goto fail;
        }
    }

    ret = sysdb_attrs_get_el(attrs, SYSDB_MEMBEROF, &el);
    if (ret) {
        goto fail;
    }
    if (el->num_values == 0) {
        DEBUG(7, ("Original memberOf is not available for [%s].\n",
                    name));
    } else {
        DEBUG(7, ("Adding original memberOf attributes to [%s].\n",
                    name));
        for (i = 0; i < el->num_values; i++) {
            ret = sysdb_attrs_add_string(user_attrs, SYSDB_ORIG_MEMBEROF,
                    (const char *) el->values[i].data);
            if (ret) {
                goto fail;
            }
        }
    }

    ret = sdap_attrs_add_string(attrs,
                            opts->user_map[SDAP_AT_USER_MODSTAMP].sys_name,
                            "original mod-Timestamp",
                            name, user_attrs);
    if (ret != EOK) {
        goto fail;
    }

    ret = sysdb_attrs_get_el(attrs,
                      opts->user_map[SDAP_AT_USER_USN].sys_name, &el);
    if (ret) {
        goto fail;
    }
    if (el->num_values == 0) {
        DEBUG(7, ("Original USN value is not available for [%s].\n",
                  name));
    } else {
        ret = sysdb_attrs_add_string(user_attrs,
                          opts->user_map[SDAP_AT_USER_USN].sys_name,
                          (const char*)el->values[0].data);
        if (ret) {
            goto fail;
        }
        usn_value = talloc_strdup(tmpctx, (const char*)el->values[0].data);
        if (!usn_value) {
            ret = ENOMEM;
            goto fail;
        }
    }

    ret = sysdb_attrs_get_el(attrs,
                             opts->user_map[SDAP_AT_USER_PRINC].sys_name, &el);
    if (ret) {
        goto fail;
    }
    if (el->num_values == 0) {
        DEBUG(7, ("User principal is not available for [%s].\n", name));
    } else {
        upn = talloc_strdup(user_attrs, (const char*) el->values[0].data);
        if (!upn) {
            ret = ENOMEM;
            goto fail;
        }
        if (dp_opt_get_bool(opts->basic, SDAP_FORCE_UPPER_CASE_REALM)) {
            make_realm_upper_case(upn);
        }
        DEBUG(7, ("Adding user principal [%s] to attributes of [%s].\n",
                  upn, name));
        ret = sysdb_attrs_add_string(user_attrs, SYSDB_UPN, upn);
        if (ret) {
            goto fail;
        }
    }

    for (i = SDAP_FIRST_EXTRA_USER_AT; i < SDAP_OPTS_USER; i++) {
        ret = sdap_attrs_add_list(attrs, opts->user_map[i].sys_name,
                                  NULL, name, user_attrs);
        if (ret) {
            goto fail;
        }
    }

    cache_timeout = dom->user_timeout;

    if (is_initgr) {
        ret = sysdb_attrs_add_time_t(user_attrs, SYSDB_INITGR_EXPIRE,
                                     (cache_timeout ?
                                      (time(NULL) + cache_timeout) : 0));
        if (ret) {
            goto fail;
        }
    }

    ret = sdap_save_all_names(name, attrs, !dom->case_sensitive, user_attrs);
    if (ret != EOK) {
        DEBUG(1, ("Failed to save user names\n"));
        goto fail;
    }

    /* Make sure that any attributes we requested from LDAP that we
     * did not receive are also removed from the sysdb
     */
    ret = list_missing_attrs(user_attrs, opts->user_map, SDAP_OPTS_USER,
                             attrs, &missing);
    if (ret != EOK) {
        goto fail;
    }

    DEBUG(6, ("Storing info for user %s\n", name));

    ret = sysdb_store_user(ctx, name, pwd, uid, gid, gecos, homedir, shell,
                           orig_dn, user_attrs, missing, cache_timeout, now);
    if (ret) goto fail;

    if (_usn_value) {
        *_usn_value = talloc_steal(memctx, usn_value);
    }

    talloc_steal(memctx, user_attrs);
    talloc_free(tmpctx);
    return EOK;

fail:
    DEBUG(2, ("Failed to save user [%s]\n",
              name ? name : "Unknown"));
    talloc_free(tmpctx);
    return ret;
}


/* ==Generic-Function-to-save-multiple-users============================= */

int sdap_save_users(TALLOC_CTX *memctx,
                    struct sysdb_ctx *sysdb,
                    struct sss_domain_info *dom,
                    struct sdap_options *opts,
                    struct sysdb_attrs **users,
                    int num_users,
                    char **_usn_value)
{
    TALLOC_CTX *tmpctx;
    char *higher_usn = NULL;
    char *usn_value;
    int ret;
    errno_t sret;
    int i;
    time_t now;
    bool in_transaction = false;

    if (num_users == 0) {
        /* Nothing to do if there are no users */
        return EOK;
    }

    tmpctx = talloc_new(memctx);
    if (!tmpctx) {
        return ENOMEM;
    }

    ret = sysdb_transaction_start(sysdb);
    if (ret) {
        DEBUG(SSSDBG_CRIT_FAILURE, ("Failed to start transaction\n"));
        goto done;
    }
    in_transaction = true;

    now = time(NULL);
    for (i = 0; i < num_users; i++) {
        usn_value = NULL;

        ret = sdap_save_user(tmpctx, sysdb, opts, dom,
                             users[i], false,
                             &usn_value, now);

        /* Do not fail completely on errors.
         * Just report the failure to save and go on */
        if (ret) {
            DEBUG(2, ("Failed to store user %d. Ignoring.\n", i));
        } else {
            DEBUG(9, ("User %d processed!\n", i));
        }

        if (usn_value) {
            if (higher_usn) {
                if ((strlen(usn_value) > strlen(higher_usn)) ||
                    (strcmp(usn_value, higher_usn) > 0)) {
                    talloc_zfree(higher_usn);
                    higher_usn = usn_value;
                } else {
                    talloc_zfree(usn_value);
                }
            } else {
                higher_usn = usn_value;
            }
        }
    }

    ret = sysdb_transaction_commit(sysdb);
    if (ret) {
        DEBUG(SSSDBG_CRIT_FAILURE, ("Failed to commit transaction!\n"));
        goto done;
    }
    in_transaction = false;

    if (_usn_value) {
        *_usn_value = talloc_steal(memctx, higher_usn);
    }

done:
    if (in_transaction) {
        sret = sysdb_transaction_cancel(sysdb);
        if (sret != EOK) {
            DEBUG(SSSDBG_CRIT_FAILURE, ("Failed to cancel transaction\n"));
        }
    }
    talloc_zfree(tmpctx);
    return ret;
}


/* ==Search-Users-with-filter============================================= */

struct sdap_get_users_state {
    struct tevent_context *ev;
    struct sdap_options *opts;
    struct sdap_handle *sh;
    struct sss_domain_info *dom;
    struct sysdb_ctx *sysdb;
    const char **attrs;
    const char *base_filter;
    char *filter;
    int timeout;
    bool enumeration;

    char *higher_usn;
    struct sysdb_attrs **users;
    size_t count;

    size_t base_iter;
    struct sdap_search_base **search_bases;
};

static errno_t sdap_get_users_next_base(struct tevent_req *req);
static void sdap_get_users_process(struct tevent_req *subreq);

struct tevent_req *sdap_get_users_send(TALLOC_CTX *memctx,
                                       struct tevent_context *ev,
                                       struct sss_domain_info *dom,
                                       struct sysdb_ctx *sysdb,
                                       struct sdap_options *opts,
                                       struct sdap_search_base **search_bases,
                                       struct sdap_handle *sh,
                                       const char **attrs,
                                       const char *filter,
                                       int timeout,
                                       bool enumeration)
{
    errno_t ret;
    struct tevent_req *req;
    struct sdap_get_users_state *state;

    req = tevent_req_create(memctx, &state, struct sdap_get_users_state);
    if (!req) return NULL;

    state->ev = ev;
    state->opts = opts;
    state->dom = dom;
    state->sh = sh;
    state->sysdb = sysdb;
    state->attrs = attrs;
    state->higher_usn = NULL;
    state->users =  NULL;
    state->count = 0;
    state->timeout = timeout;
    state->base_filter = filter;
    state->base_iter = 0;
    state->search_bases = search_bases;
    state->enumeration = enumeration;

    if (!state->search_bases) {
        DEBUG(SSSDBG_CRIT_FAILURE,
              ("User lookup request without a search base\n"));
        ret = EINVAL;
        goto done;
    }

    ret = sdap_get_users_next_base(req);

done:
    if (ret != EOK) {
        tevent_req_error(req, ret);
        tevent_req_post(req, state->ev);
    }

    return req;
}

static errno_t sdap_get_users_next_base(struct tevent_req *req)
{
    struct tevent_req *subreq;
    struct sdap_get_users_state *state;

    state = tevent_req_data(req, struct sdap_get_users_state);

    talloc_zfree(state->filter);
    state->filter = sdap_get_id_specific_filter(state,
                        state->base_filter,
                        state->search_bases[state->base_iter]->filter);
    if (!state->filter) {
        return ENOMEM;
    }

    DEBUG(SSSDBG_TRACE_FUNC,
          ("Searching for users with base [%s]\n",
           state->search_bases[state->base_iter]->basedn));

    subreq = sdap_get_generic_send(
            state, state->ev, state->opts, state->sh,
            state->search_bases[state->base_iter]->basedn,
            state->search_bases[state->base_iter]->scope,
            state->filter, state->attrs,
            state->opts->user_map, SDAP_OPTS_USER,
            state->timeout,
            state->enumeration); /* If we're enumerating, we need paging */
    if (!subreq) {
        return ENOMEM;
    }
    tevent_req_set_callback(subreq, sdap_get_users_process, req);

    return EOK;
}

static void sdap_get_users_process(struct tevent_req *subreq)
{
    struct tevent_req *req = tevent_req_callback_data(subreq,
                                                      struct tevent_req);
    struct sdap_get_users_state *state = tevent_req_data(req,
                                            struct sdap_get_users_state);
    int ret;
    size_t count, i;
    struct sysdb_attrs **users;
    bool next_base = false;

    ret = sdap_get_generic_recv(subreq, state,
                                &count, &users);
    talloc_zfree(subreq);
    if (ret) {
        tevent_req_error(req, ret);
        return;
    }

    DEBUG(6, ("Search for users, returned %d results.\n", count));

    if (state->enumeration || count == 0) {
        /* No users found in this search or enumerating */
        next_base = true;
    }

    /* Add this batch of users to the list */
    if (count > 0) {
        state->users =
                talloc_realloc(state,
                               state->users,
                               struct sysdb_attrs *,
                               state->count + count + 1);
        if (!state->users) {
            tevent_req_error(req, ENOMEM);
            return;
        }

        /* Copy the new users into the list
         * They're already allocated on 'state'
         */
        for (i = 0; i < count; i++) {
            state->users[state->count + i] =
                talloc_steal(state->users, users[i]);
        }

        state->count += count;
        state->users[state->count] = NULL;
    }

    if (next_base) {
        state->base_iter++;
        if (state->search_bases[state->base_iter]) {
            /* There are more search bases to try */
            ret = sdap_get_users_next_base(req);
            if (ret != EOK) {
                tevent_req_error(req, ret);
            }
            return;
        }
    }

    /* No more search bases
     * Return ENOENT if no users were found
     */
    if (state->count == 0) {
        tevent_req_error(req, ENOENT);
        return;
    }

    ret = sdap_save_users(state, state->sysdb,
                          state->dom, state->opts,
                          state->users, state->count,
                          &state->higher_usn);
    if (ret) {
        DEBUG(2, ("Failed to store users.\n"));
        tevent_req_error(req, ret);
        return;
    }

    DEBUG(9, ("Saving %d Users - Done\n", state->count));

    tevent_req_done(req);
}

int sdap_get_users_recv(struct tevent_req *req,
                        TALLOC_CTX *mem_ctx, char **usn_value)
{
    struct sdap_get_users_state *state = tevent_req_data(req,
                                            struct sdap_get_users_state);

    TEVENT_REQ_RETURN_ON_ERROR(req);

    if (usn_value) {
        *usn_value = talloc_steal(mem_ctx, state->higher_usn);
    }

    return EOK;
}