/*
   SSSD

   sss_groupmod

   Copyright (C) Jakub Hrozek <jhrozek@redhat.com>        2009

   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 <stdio.h>
#include <stdlib.h>
#include <talloc.h>
#include <popt.h>
#include <errno.h>
#include <grp.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "util/util.h"
#include "db/sysdb.h"
#include "tools/tools_util.h"

#ifndef GROUPMOD
#define GROUPMOD SHADOW_UTILS_PATH"/groupmod "
#endif

#ifndef GROUPMOD_GID
#define GROUPMOD_GID "-g %u "
#endif

#ifndef GROUPMOD_GROUPNAME
#define GROUPMOD_GROUPNAME "%s "
#endif

static void mod_group_req_done(struct tevent_req *req)
{
    struct ops_ctx *data = tevent_req_callback_data(req, struct ops_ctx);

    data->error = sysdb_transaction_commit_recv(req);
    data->done = true;
}

static void mod_group_done(struct ops_ctx *data, int error)
{
    struct tevent_req *req;

    if (error != EOK) {
        goto fail;
    }

    req = sysdb_transaction_commit_send(data, data->ev, data->handle);
    if (!req) {
        error = ENOMEM;
        goto fail;
    }
    tevent_req_set_callback(req, mod_group_req_done, data);

    return;

fail:
    /* free transaction */
    talloc_zfree(data->handle);

    data->error = error;
    data->done = true;
}

static void mod_group_attr_done(struct tevent_req *req);
static void mod_group_cont(struct ops_ctx *data);
static void remove_from_groups(struct ops_ctx *data);
static void remove_from_groups_done(struct tevent_req *req);
static void add_to_groups(struct ops_ctx *data);
static void add_to_groups_done(struct tevent_req *req);

static void mod_group(struct tevent_req *req)
{
    struct ops_ctx *data;
    struct tevent_req *subreq;
    struct sysdb_attrs *attrs;
    int ret;

    data = tevent_req_callback_data(req, struct ops_ctx);

    ret = sysdb_transaction_recv(req, data, &data->handle);
    if (ret != EOK) {
        return mod_group_done(data, ret);
    }
    talloc_zfree(req);

    if (data->gid != 0) {
        attrs = sysdb_new_attrs(data);
        if (!attrs) {
            mod_group_done(data, ENOMEM);
        }
        ret = sysdb_attrs_add_uint32(attrs, SYSDB_GIDNUM, data->gid);
        if (ret) {
            mod_group_done(data, ret);
        }

        subreq = sysdb_set_group_attr_send(data, data->ev, data->handle,
                                           data->domain, data->name,
                                           attrs, SYSDB_MOD_REP);
        if (!subreq) {
            return mod_group_done(data, ENOMEM);
        }
        tevent_req_set_callback(subreq, mod_group_attr_done, data);
        return;
    }

    return mod_group_cont(data);
}

static void mod_group_attr_done(struct tevent_req *subreq)
{
    struct ops_ctx *data = tevent_req_callback_data(subreq, struct ops_ctx);
    int ret;

    ret = sysdb_set_group_attr_recv(subreq);
    talloc_zfree(subreq);
    if (ret != EOK) {
        return mod_group_done(data, ret);
    }

    mod_group_cont(data);
}

static void mod_group_cont(struct ops_ctx *data)
{
    if (data->rmgroups != NULL) {
        return remove_from_groups(data);
    }

    if (data->addgroups != NULL) {
        return add_to_groups(data);
    }

    return mod_group_done(data, EOK);
}

static void remove_from_groups(struct ops_ctx *data)
{
    struct ldb_dn *parent_dn;
    struct ldb_dn *member_dn;
    struct tevent_req *req;

    parent_dn = sysdb_group_dn(data->ctx->sysdb, data,
                               data->domain->name, data->name);
    if (!parent_dn) {
        return mod_group_done(data, ENOMEM);
    }

    member_dn = sysdb_group_dn(data->ctx->sysdb, data,
                               data->domain->name,
                               data->rmgroups[data->cur]);
    if (!member_dn) {
        return mod_group_done(data, ENOMEM);
    }

    req = sysdb_mod_group_member_send(data,
                                      data->ev,
                                      data->handle,
                                      member_dn,
                                      parent_dn,
                                      LDB_FLAG_MOD_DELETE);
    if (!req) {
        return mod_group_done(data, ENOMEM);
    }
    tevent_req_set_callback(req, remove_from_groups_done, data);
}

static void remove_from_groups_done(struct tevent_req *req)
{
    struct ops_ctx *data = tevent_req_callback_data(req, struct ops_ctx);
    int ret;

    ret = sysdb_mod_group_member_recv(req);
    if (ret) {
        return mod_group_done(data, ret);
    }
    talloc_zfree(req);

    /* go on to next group */
    data->cur++;

    /* check if we added all of them */
    if (data->rmgroups[data->cur] == NULL) {
        data->cur = 0;
        if (data->addgroups != NULL) {
            return remove_from_groups(data);
        }
        return mod_group_done(data, EOK);
    }

    return remove_from_groups(data);
}

static void add_to_groups(struct ops_ctx *data)
{
    struct ldb_dn *parent_dn;
    struct ldb_dn *member_dn;
    struct tevent_req *req;

    parent_dn = sysdb_group_dn(data->ctx->sysdb, data,
                               data->domain->name, data->name);
    if (!parent_dn) {
        return mod_group_done(data, ENOMEM);
    }

    member_dn = sysdb_group_dn(data->ctx->sysdb, data,
                               data->domain->name,
                               data->addgroups[data->cur]);
    if (!member_dn) {
        return mod_group_done(data, ENOMEM);
    }

    req = sysdb_mod_group_member_send(data,
                                      data->ev,
                                      data->handle,
                                      member_dn,
                                      parent_dn,
                                      LDB_FLAG_MOD_ADD);
    if (!req) {
        return mod_group_done(data, ENOMEM);
    }
    tevent_req_set_callback(req, add_to_groups_done, data);
}

static void add_to_groups_done(struct tevent_req *req)
{
    struct ops_ctx *data = tevent_req_callback_data(req, struct ops_ctx);
    int ret;

    ret = sysdb_mod_group_member_recv(req);
    if (ret) {
        return mod_group_done(data, ret);
    }
    talloc_zfree(req);

    /* go on to next group */
    data->cur++;

    /* check if we added all of them */
    if (data->addgroups[data->cur] == NULL) {
        return mod_group_done(data, EOK);
    }

    return add_to_groups(data);
}

static int groupmod_legacy(struct tools_ctx *tools_ctx,
                           struct ops_ctx *ctx,
                           struct sss_domain_info *old_domain)
{
    int ret = EOK;
    char *command = NULL;
    struct sss_domain_info *dom = NULL;

    APPEND_STRING(command, GROUPMOD);

    if (ctx->addgroups || ctx->rmgroups) {
        ERROR("Group nesting is not supported in this domain\n");
        talloc_free(command);
        return EINVAL;
    }

    if (ctx->gid) {
        ret = get_domain_by_id(tools_ctx, ctx->gid, &dom);
        if (ret != EOK) {
            ERROR("Cannot get domain info\n");
            talloc_free(command);
            return EINVAL;
        }
        if (dom == old_domain) {
            APPEND_PARAM(command, GROUPMOD_GID, ctx->gid);
        } else {
            ERROR("Changing gid only allowed inside the same domain\n");
            talloc_free(command);
            return EINVAL;
        }
    }

    APPEND_PARAM(command, GROUPMOD_GROUPNAME, ctx->name);

    ret = system(command);
    if (ret) {
        if (ret == -1) {
            DEBUG(1, ("system(3) failed\n"));
        } else {
            DEBUG(1, ("Could not exec '%s', return code: %d\n",
                      command, WEXITSTATUS(ret)));
        }
        talloc_free(command);
        return EFAULT;
    }

    talloc_free(command);
    return ret;
}

int main(int argc, const char **argv)
{
    gid_t pc_gid = 0;
    int pc_debug = 0;
    struct poptOption long_options[] = {
        POPT_AUTOHELP
        { "debug", '\0', POPT_ARG_INT | POPT_ARGFLAG_DOC_HIDDEN, &pc_debug,
                            0, _("The debug level to run with"), NULL },
        { "append-group", 'a', POPT_ARG_STRING, NULL,
                            'a', _("Groups to add this group to"), NULL },
        { "remove-group", 'r', POPT_ARG_STRING, NULL,
                            'r', _("Groups to remove this group from"), NULL },
        { "gid",   'g', POPT_ARG_INT | POPT_ARGFLAG_DOC_HIDDEN, &pc_gid,
                            0, _("The GID of the group"), NULL },
        POPT_TABLEEND
    };
    poptContext pc = NULL;
    struct sss_domain_info *dom;
    struct ops_ctx *data = NULL;
    struct tools_ctx *ctx = NULL;
    struct tevent_req *req;
    char *groups;
    int ret;
    struct group *grp_info;
    gid_t old_gid = 0;
    const char *pc_groupname = NULL;

    debug_prg_name = argv[0];

    ret = set_locale();
    if (ret != EOK) {
        DEBUG(1, ("set_locale failed (%d): %s\n", ret, strerror(ret)));
        ERROR("Error setting the locale\n");
        ret = EXIT_FAILURE;
        goto fini;
    }
    CHECK_ROOT(ret, debug_prg_name);

    ret = init_sss_tools(&ctx);
    if (ret != EOK) {
        DEBUG(1, ("init_sss_tools failed (%d): %s\n", ret, strerror(ret)));
        ERROR("Error initializing the tools\n");
        ret = EXIT_FAILURE;
        goto fini;
    }

    data = talloc_zero(ctx, struct ops_ctx);
    if (data == NULL) {
        DEBUG(1, ("Could not allocate memory for data context\n"));
        ERROR("Out of memory\n");
        return ENOMEM;
    }
    data->ctx = ctx;
    data->ev = ctx->ev;

    /* parse ops_ctx */
    pc = poptGetContext(NULL, argc, argv, long_options, 0);
    poptSetOtherOptionHelp(pc, "USERNAME");
    while ((ret = poptGetNextOpt(pc)) > 0) {
        if (ret == 'a' || ret == 'r') {
            groups = poptGetOptArg(pc);
            if (!groups) {
                ret = -1;
                break;
            }

            ret = parse_groups(ctx,
                    groups,
                    (ret == 'a') ? (&data->addgroups) : (&data->rmgroups));

            free(groups);
            if (ret != EOK) {
                break;
            }
        }
    }

    debug_level = pc_debug;

    if (ret != -1) {
        usage(pc, poptStrerror(ret));
        ret = EXIT_FAILURE;
        goto fini;
    }

    /* groupname is an argument without --option */
    pc_groupname = poptGetArg(pc);
    if (pc_groupname == NULL) {
        usage(pc, _("Specify group to modify\n"));
        ret = EXIT_FAILURE;
        goto fini;
    }

    ret = parse_name_domain(data, pc_groupname);
    if (ret != EOK) {
        ret = EXIT_FAILURE;
        goto fini;
    }

    data->gid = pc_gid;

    /* arguments processed, go on to actual work */
    grp_info = getgrnam(data->name);
    if (grp_info) {
       old_gid = grp_info->gr_gid;
    }

    ret = get_domain_by_id(data->ctx, data->gid, &dom);
    if (ret != EOK) {
        ERROR("Cannot get domain info\n");
        ret = EXIT_FAILURE;
        goto fini;
    }
    if (data->domain && data->gid && data->domain != dom) {
        ERROR("Selected domain %s conflicts with selected GID %llu\n",
                data->domain->name, (unsigned long long int) data->gid);
        ret = EXIT_FAILURE;
        goto fini;
    }
    if (data->domain == NULL && dom) {
        data->domain = dom;
    }

    ret = get_domain_type(data->ctx, data->domain);
    switch (ret) {
        case ID_IN_LOCAL:
            break;

        case ID_IN_LEGACY_LOCAL:
        case ID_OUTSIDE:
            ret = groupmod_legacy(ctx, data, data->domain);
            if(ret != EOK) {
                ERROR("Cannot delete group from domain using the legacy tools\n");
            }
            goto fini;

        case ID_IN_OTHER:
            DEBUG(1, ("Cannot modify group from domain %s\n", dom->name));
            ERROR("Unsupported domain type\n");
            ret = EXIT_FAILURE;
            goto fini;

        default:
            DEBUG(1, ("Unknown return code %d from get_domain_type\n", ret));
            ERROR("Error looking up domain\n");
            ret = EXIT_FAILURE;
            goto fini;
    }

    req = sysdb_transaction_send(ctx, ctx->ev, ctx->sysdb);
    if (!req) {
        DEBUG(1, ("Could not start transaction (%d)[%s]\n", ret, strerror(ret)));
        ERROR("Transaction error. Could not modify group.\n");
        ret = EXIT_FAILURE;
        goto fini;
    }
    tevent_req_set_callback(req, mod_group, data);

    while (!data->done) {
        tevent_loop_once(ctx->ev);
    }

    if (data->error) {
        ret = data->error;
        DEBUG(1, ("sysdb operation failed (%d)[%s]\n", ret, strerror(ret)));
        switch (ret) {
            case ENOENT:
                ERROR("Could not modify group - check if member group names are correct\n");
                break;

            case EFAULT:
                ERROR("Could not modify group - check if groupname is correct\n");
                break;

            default:
                ERROR("Transaction error. Could not modify group.\n");
                break;
        }

        ret = EXIT_FAILURE;
        goto fini;
    }

    ret = EXIT_SUCCESS;

fini:
    poptFreeContext(pc);
    talloc_free(ctx);
    exit(ret);
}