/*
 * 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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2013, 2015 by Delphix. All rights reserved.
 * Copyright (c) 2012 Pawel Jakub Dawidek. All rights reserved.
 * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
 */

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <stddef.h>
#include <libintl.h>
#include <libzfs.h>
#include <libzutil.h>

#include "libzfs_impl.h"

int
zfs_iter_clones(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
        nvlist_t *nvl = zfs_get_clones_nvl(zhp);
        nvpair_t *pair;

        if (nvl == NULL)
                return (0);

        for (pair = nvlist_next_nvpair(nvl, NULL); pair != NULL;
            pair = nvlist_next_nvpair(nvl, pair)) {
                zfs_handle_t *clone = zfs_open(zhp->zfs_hdl, nvpair_name(pair),
                    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME);
                if (clone != NULL) {
                        int err = func(clone, data);
                        if (err != 0)
                                return (err);
                }
        }
        return (0);
}

static int
zfs_do_list_ioctl(zfs_handle_t *zhp, int arg, zfs_cmd_t *zc)
{
        int rc;
        uint64_t        orig_cookie;

        orig_cookie = zc->zc_cookie;
top:
        (void) strlcpy(zc->zc_name, zhp->zfs_name, sizeof (zc->zc_name));
        rc = ioctl(zhp->zfs_hdl->libzfs_fd, arg, zc);

        if (rc == -1) {
                switch (errno) {
                case ENOMEM:
                        /* expand nvlist memory and try again */
                        if (zcmd_expand_dst_nvlist(zhp->zfs_hdl, zc) != 0) {
                                zcmd_free_nvlists(zc);
                                return (-1);
                        }
                        zc->zc_cookie = orig_cookie;
                        goto top;
                /*
                 * An errno value of ESRCH indicates normal completion.
                 * If ENOENT is returned, then the underlying dataset
                 * has been removed since we obtained the handle.
                 */
                case ESRCH:
                case ENOENT:
                        rc = 1;
                        break;
                default:
                        rc = zfs_standard_error(zhp->zfs_hdl, errno,
                            dgettext(TEXT_DOMAIN,
                            "cannot iterate filesystems"));
                        break;
                }
        }
        return (rc);
}

/*
 * Iterate over all child filesystems
 */
int
zfs_iter_filesystems(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
        zfs_cmd_t zc = { 0 };
        zfs_handle_t *nzhp;
        int ret;

        if (zhp->zfs_type != ZFS_TYPE_FILESYSTEM)
                return (0);

        if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
                return (-1);

        while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_DATASET_LIST_NEXT,
            &zc)) == 0) {
                /*
                 * Silently ignore errors, as the only plausible explanation is
                 * that the pool has since been removed.
                 */
                if ((nzhp = make_dataset_handle_zc(zhp->zfs_hdl,
                    &zc)) == NULL) {
                        continue;
                }

                if ((ret = func(nzhp, data)) != 0) {
                        zcmd_free_nvlists(&zc);
                        return (ret);
                }
        }
        zcmd_free_nvlists(&zc);
        return ((ret < 0) ? ret : 0);
}

/*
 * Iterate over all snapshots
 */
int
zfs_iter_snapshots(zfs_handle_t *zhp, boolean_t simple, zfs_iter_f func,
    void *data)
{
        zfs_cmd_t zc = { 0 };
        zfs_handle_t *nzhp;
        int ret;

        if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT ||
            zhp->zfs_type == ZFS_TYPE_BOOKMARK)
                return (0);

        zc.zc_simple = simple;

        if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
                return (-1);
        while ((ret = zfs_do_list_ioctl(zhp, ZFS_IOC_SNAPSHOT_LIST_NEXT,
            &zc)) == 0) {

                if (simple)
                        nzhp = make_dataset_simple_handle_zc(zhp, &zc);
                else
                        nzhp = make_dataset_handle_zc(zhp->zfs_hdl, &zc);
                if (nzhp == NULL)
                        continue;

                if ((ret = func(nzhp, data)) != 0) {
                        zcmd_free_nvlists(&zc);
                        return (ret);
                }
        }
        zcmd_free_nvlists(&zc);
        return ((ret < 0) ? ret : 0);
}

/*
 * Iterate over all bookmarks
 */
int
zfs_iter_bookmarks(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
        zfs_handle_t *nzhp;
        nvlist_t *props = NULL;
        nvlist_t *bmarks = NULL;
        int err;

        if ((zfs_get_type(zhp) & (ZFS_TYPE_SNAPSHOT | ZFS_TYPE_BOOKMARK)) != 0)
                return (0);

        /* Setup the requested properties nvlist. */
        props = fnvlist_alloc();
        fnvlist_add_boolean(props, zfs_prop_to_name(ZFS_PROP_GUID));
        fnvlist_add_boolean(props, zfs_prop_to_name(ZFS_PROP_CREATETXG));
        fnvlist_add_boolean(props, zfs_prop_to_name(ZFS_PROP_CREATION));
        fnvlist_add_boolean(props, zfs_prop_to_name(ZFS_PROP_IVSET_GUID));

        if ((err = lzc_get_bookmarks(zhp->zfs_name, props, &bmarks)) != 0)
                goto out;

        for (nvpair_t *pair = nvlist_next_nvpair(bmarks, NULL);
            pair != NULL; pair = nvlist_next_nvpair(bmarks, pair)) {
                char name[ZFS_MAX_DATASET_NAME_LEN];
                char *bmark_name;
                nvlist_t *bmark_props;

                bmark_name = nvpair_name(pair);
                bmark_props = fnvpair_value_nvlist(pair);

                (void) snprintf(name, sizeof (name), "%s#%s", zhp->zfs_name,
                    bmark_name);

                nzhp = make_bookmark_handle(zhp, name, bmark_props);
                if (nzhp == NULL)
                        continue;

                if ((err = func(nzhp, data)) != 0)
                        goto out;
        }

out:
        fnvlist_free(props);
        fnvlist_free(bmarks);

        return (err);
}

/*
 * Routines for dealing with the sorted snapshot functionality
 */
typedef struct zfs_node {
        zfs_handle_t    *zn_handle;
        avl_node_t      zn_avlnode;
} zfs_node_t;

static int
zfs_sort_snaps(zfs_handle_t *zhp, void *data)
{
        avl_tree_t *avl = data;
        zfs_node_t *node;
        zfs_node_t search;

        search.zn_handle = zhp;
        node = avl_find(avl, &search, NULL);
        if (node) {
                /*
                 * If this snapshot was renamed while we were creating the
                 * AVL tree, it's possible that we already inserted it under
                 * its old name. Remove the old handle before adding the new
                 * one.
                 */
                zfs_close(node->zn_handle);
                avl_remove(avl, node);
                free(node);
        }

        node = zfs_alloc(zhp->zfs_hdl, sizeof (zfs_node_t));
        node->zn_handle = zhp;
        avl_add(avl, node);

        return (0);
}

static int
zfs_snapshot_compare(const void *larg, const void *rarg)
{
        zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle;
        zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle;
        uint64_t lcreate, rcreate;

        /*
         * Sort them according to creation time.  We use the hidden
         * CREATETXG property to get an absolute ordering of snapshots.
         */
        lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG);
        rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG);

        if (lcreate < rcreate)
                return (-1);
        if (lcreate > rcreate)
                return (+1);
        return (0);
}

int
zfs_iter_snapshots_sorted(zfs_handle_t *zhp, zfs_iter_f callback, void *data)
{
        int ret = 0;
        zfs_node_t *node;
        avl_tree_t avl;
        void *cookie = NULL;

        avl_create(&avl, zfs_snapshot_compare,
            sizeof (zfs_node_t), offsetof(zfs_node_t, zn_avlnode));

        ret = zfs_iter_snapshots(zhp, B_FALSE, zfs_sort_snaps, &avl);

        for (node = avl_first(&avl); node != NULL; node = AVL_NEXT(&avl, node))
                ret |= callback(node->zn_handle, data);

        while ((node = avl_destroy_nodes(&avl, &cookie)) != NULL)
                free(node);

        avl_destroy(&avl);

        return (ret);
}

typedef struct {
        char *ssa_first;
        char *ssa_last;
        boolean_t ssa_seenfirst;
        boolean_t ssa_seenlast;
        zfs_iter_f ssa_func;
        void *ssa_arg;
} snapspec_arg_t;

static int
snapspec_cb(zfs_handle_t *zhp, void *arg)
{
        snapspec_arg_t *ssa = arg;
        const char *shortsnapname;
        int err = 0;

        if (ssa->ssa_seenlast)
                return (0);

        shortsnapname = strchr(zfs_get_name(zhp), '@') + 1;
        if (!ssa->ssa_seenfirst && strcmp(shortsnapname, ssa->ssa_first) == 0)
                ssa->ssa_seenfirst = B_TRUE;
        if (strcmp(shortsnapname, ssa->ssa_last) == 0)
                ssa->ssa_seenlast = B_TRUE;

        if (ssa->ssa_seenfirst) {
                err = ssa->ssa_func(zhp, ssa->ssa_arg);
        } else {
                zfs_close(zhp);
        }

        return (err);
}

/*
 * spec is a string like "A,B%C,D"
 *
 * <snaps>, where <snaps> can be:
 *      <snap>          (single snapshot)
 *      <snap>%<snap>   (range of snapshots, inclusive)
 *      %<snap>         (range of snapshots, starting with earliest)
 *      <snap>%         (range of snapshots, ending with last)
 *      %               (all snapshots)
 *      <snaps>[,...]   (comma separated list of the above)
 *
 * If a snapshot can not be opened, continue trying to open the others, but
 * return ENOENT at the end.
 */
int
zfs_iter_snapspec(zfs_handle_t *fs_zhp, const char *spec_orig,
    zfs_iter_f func, void *arg)
{
        char *buf, *comma_separated, *cp;
        int err = 0;
        int ret = 0;

        buf = zfs_strdup(fs_zhp->zfs_hdl, spec_orig);
        cp = buf;

        while ((comma_separated = strsep(&cp, ",")) != NULL) {
                char *pct = strchr(comma_separated, '%');
                if (pct != NULL) {
                        snapspec_arg_t ssa = { 0 };
                        ssa.ssa_func = func;
                        ssa.ssa_arg = arg;

                        if (pct == comma_separated)
                                ssa.ssa_seenfirst = B_TRUE;
                        else
                                ssa.ssa_first = comma_separated;
                        *pct = '\0';
                        ssa.ssa_last = pct + 1;

                        /*
                         * If there is a lastname specified, make sure it
                         * exists.
                         */
                        if (ssa.ssa_last[0] != '\0') {
                                char snapname[ZFS_MAX_DATASET_NAME_LEN];
                                (void) snprintf(snapname, sizeof (snapname),
                                    "%s@%s", zfs_get_name(fs_zhp),
                                    ssa.ssa_last);
                                if (!zfs_dataset_exists(fs_zhp->zfs_hdl,
                                    snapname, ZFS_TYPE_SNAPSHOT)) {
                                        ret = ENOENT;
                                        continue;
                                }
                        }

                        err = zfs_iter_snapshots_sorted(fs_zhp,
                            snapspec_cb, &ssa);
                        if (ret == 0)
                                ret = err;
                        if (ret == 0 && (!ssa.ssa_seenfirst ||
                            (ssa.ssa_last[0] != '\0' && !ssa.ssa_seenlast))) {
                                ret = ENOENT;
                        }
                } else {
                        char snapname[ZFS_MAX_DATASET_NAME_LEN];
                        zfs_handle_t *snap_zhp;
                        (void) snprintf(snapname, sizeof (snapname), "%s@%s",
                            zfs_get_name(fs_zhp), comma_separated);
                        snap_zhp = make_dataset_handle(fs_zhp->zfs_hdl,
                            snapname);
                        if (snap_zhp == NULL) {
                                ret = ENOENT;
                                continue;
                        }
                        err = func(snap_zhp, arg);
                        if (ret == 0)
                                ret = err;
                }
        }

        free(buf);
        return (ret);
}

/*
 * Iterate over all children, snapshots and filesystems
 * Process snapshots before filesystems because they are nearer the input
 * handle: this is extremely important when used with zfs_iter_f functions
 * looking for data, following the logic that we would like to find it as soon
 * and as close as possible.
 */
int
zfs_iter_children(zfs_handle_t *zhp, zfs_iter_f func, void *data)
{
        int ret;

        if ((ret = zfs_iter_snapshots(zhp, B_FALSE, func, data)) != 0)
                return (ret);

        return (zfs_iter_filesystems(zhp, func, data));
}


typedef struct iter_stack_frame {
        struct iter_stack_frame *next;
        zfs_handle_t *zhp;
} iter_stack_frame_t;

typedef struct iter_dependents_arg {
        boolean_t first;
        boolean_t allowrecursion;
        iter_stack_frame_t *stack;
        zfs_iter_f func;
        void *data;
} iter_dependents_arg_t;

static int
iter_dependents_cb(zfs_handle_t *zhp, void *arg)
{
        iter_dependents_arg_t *ida = arg;
        int err = 0;
        boolean_t first = ida->first;
        ida->first = B_FALSE;

        if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT) {
                err = zfs_iter_clones(zhp, iter_dependents_cb, ida);
        } else if (zhp->zfs_type != ZFS_TYPE_BOOKMARK) {
                iter_stack_frame_t isf;
                iter_stack_frame_t *f;

                /*
                 * check if there is a cycle by seeing if this fs is already
                 * on the stack.
                 */
                for (f = ida->stack; f != NULL; f = f->next) {
                        if (f->zhp->zfs_dmustats.dds_guid ==
                            zhp->zfs_dmustats.dds_guid) {
                                if (ida->allowrecursion) {
                                        zfs_close(zhp);
                                        return (0);
                                } else {
                                        zfs_error_aux(zhp->zfs_hdl,
                                            dgettext(TEXT_DOMAIN,
                                            "recursive dependency at '%s'"),
                                            zfs_get_name(zhp));
                                        err = zfs_error(zhp->zfs_hdl,
                                            EZFS_RECURSIVE,
                                            dgettext(TEXT_DOMAIN,
                                            "cannot determine dependent "
                                            "datasets"));
                                        zfs_close(zhp);
                                        return (err);
                                }
                        }
                }

                isf.zhp = zhp;
                isf.next = ida->stack;
                ida->stack = &isf;
                err = zfs_iter_filesystems(zhp, iter_dependents_cb, ida);
                if (err == 0) {
                        err = zfs_iter_snapshots(zhp, B_FALSE,
                            iter_dependents_cb, ida);
                }
                ida->stack = isf.next;
        }

        if (!first && err == 0)
                err = ida->func(zhp, ida->data);
        else
                zfs_close(zhp);

        return (err);
}

int
zfs_iter_dependents(zfs_handle_t *zhp, boolean_t allowrecursion,
    zfs_iter_f func, void *data)
{
        iter_dependents_arg_t ida;
        ida.allowrecursion = allowrecursion;
        ida.stack = NULL;
        ida.func = func;
        ida.data = data;
        ida.first = B_TRUE;
        return (iter_dependents_cb(zfs_handle_dup(zhp), &ida));
}