Rename server/ directory to src/

Also update BUILD.txt

1 files changed, 3612 insertions, 0 deletions

diff --git a/src/ldb_modules/memberof.c b/src/ldb_modules/memberof.c
new file mode 100644
index 00000000..e0a241a5
--- /dev/null
+++ b/src/ldb_modules/memberof.c
@@ -0,0 +1,3612 @@
+/*
+   SSSD memberof module
+
+   Copyright (C) Simo Sorce <idra@samba.org> 2008
+
+   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 <string.h>
+#include "ldb_module.h"
+#include "util/util.h"
+#include "dhash.h"
+
+#define DB_MEMBER "member"
+#define DB_MEMBEROF "memberof"
+#define DB_MEMBERUID "memberuid"
+#define DB_NAME "name"
+#define DB_USER_CLASS "user"
+#define DB_OC "objectClass"
+
+#ifndef talloc_zfree
+#define talloc_zfree(ptr) do { talloc_free(ptr); ptr = NULL; } while(0)
+#endif
+
+#ifndef MAX
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+#endif
+
+struct mbof_dn_array {
+    struct ldb_dn **dns;
+    int num;
+};
+
+struct mbof_dn {
+    struct mbof_dn *next;
+    struct ldb_dn *dn;
+};
+
+struct mbof_ctx {
+    struct ldb_module *module;
+    struct ldb_request *req;
+
+    struct ldb_control **ret_ctrls;
+    struct ldb_extended *ret_resp;
+};
+
+struct mbof_add_operation {
+    struct mbof_add_ctx *add_ctx;
+    struct mbof_add_operation *next;
+
+    struct mbof_dn_array *parents;
+    struct ldb_dn *entry_dn;
+
+    struct ldb_message *entry;
+};
+
+struct mbof_memberuid_op {
+    struct ldb_dn *dn;
+    struct ldb_message_element *el;
+};
+
+struct mbof_add_ctx {
+    struct mbof_ctx *ctx;
+
+    struct mbof_add_operation *add_list;
+    struct mbof_add_operation *current_op;
+
+    struct ldb_message *msg;
+    struct ldb_dn *msg_dn;
+    bool terminate;
+
+    struct mbof_dn *missing;
+
+    struct mbof_memberuid_op *muops;
+    int num_muops;
+    int cur_muop;
+};
+
+struct mbof_del_ancestors_ctx {
+    struct mbof_dn_array *new_list;
+    int num_direct;
+    int cur;
+
+    struct ldb_message *entry;
+};
+
+struct mbof_del_operation {
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_del_operation *parent;
+    struct mbof_del_operation **children;
+    int num_children;
+    int next_child;
+
+    struct ldb_dn *entry_dn;
+
+    struct ldb_message *entry;
+    struct ldb_message **parents;
+    int num_parents;
+    int cur_parent;
+
+    struct mbof_del_ancestors_ctx *anc_ctx;
+};
+
+struct mbof_mod_ctx;
+
+struct mbof_del_ctx {
+    struct mbof_ctx *ctx;
+
+    struct mbof_del_operation *first;
+    struct mbof_dn *history;
+
+    struct ldb_message **mus;
+    int num_mus;
+
+    struct mbof_memberuid_op *muops;
+    int num_muops;
+    int cur_muop;
+
+    struct mbof_mod_ctx *follow_mod;
+    bool is_mod;
+};
+
+struct mbof_mod_ctx {
+    struct mbof_ctx *ctx;
+
+    const struct ldb_message_element *membel;
+    struct ldb_message *entry;
+
+    struct mbof_dn_array *to_add;
+
+    struct ldb_message *msg;
+    bool terminate;
+};
+
+static struct mbof_ctx *mbof_init(struct ldb_module *module,
+                                  struct ldb_request *req)
+{
+    struct mbof_ctx *ctx;
+
+    ctx = talloc_zero(req, struct mbof_ctx);
+    if (!ctx) {
+        return NULL;
+    }
+
+    ctx->module = module;
+    ctx->req = req;
+
+    return ctx;
+}
+
+static int entry_is_user_object(struct ldb_message *entry)
+{
+    struct ldb_message_element *el;
+    struct ldb_val *val;
+    int i;
+
+    el = ldb_msg_find_element(entry, DB_OC);
+    if (!el) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    /* see if this is a user */
+    for (i = 0; i < el->num_values; i++) {
+        val = &(el->values[i]);
+        if (strncasecmp(DB_USER_CLASS, (char *)val->data, val->length) == 0) {
+            return LDB_SUCCESS;
+        }
+    }
+
+    return LDB_ERR_NO_SUCH_ATTRIBUTE;
+}
+
+static int mbof_append_muop(TALLOC_CTX *memctx,
+                            struct mbof_memberuid_op **_muops,
+                            int *_num_muops,
+                            int flags,
+                            struct ldb_dn *parent,
+                            const char *name)
+{
+    struct mbof_memberuid_op *muops = *_muops;
+    int num_muops = *_num_muops;
+    struct mbof_memberuid_op *op;
+    struct ldb_val *val;
+    int i;
+
+    op = NULL;
+    if (muops) {
+        for (i = 0; i < num_muops; i++) {
+            if (ldb_dn_compare(parent, muops[i].dn) == 0) {
+                op = &muops[i];
+                break;
+            }
+        }
+    }
+    if (!op) {
+        muops = talloc_realloc(memctx, muops,
+                               struct mbof_memberuid_op,
+                               num_muops + 1);
+        if (!muops) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+        op = &muops[num_muops];
+        num_muops++;
+        *_muops = muops;
+        *_num_muops = num_muops;
+
+        op->dn = parent;
+        op->el = NULL;
+    }
+
+    if (!op->el) {
+        op->el = talloc_zero(muops, struct ldb_message_element);
+        if (!op->el) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+        op->el->name = talloc_strdup(op->el, DB_MEMBERUID);
+        if (!op->el->name) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+        op->el->flags = flags;
+    }
+
+    for (i = 0; i < op->el->num_values; i++) {
+        if (strcmp((char *)op->el->values[i].data, name) == 0) {
+            /* we already have this value, get out*/
+            return LDB_SUCCESS;
+        }
+    }
+
+    val = talloc_realloc(op->el, op->el->values,
+                         struct ldb_val, op->el->num_values + 1);
+    if (!val) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    val[op->el->num_values].data = (uint8_t *)talloc_strdup(val, name);
+    if (!val[op->el->num_values].data) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    val[op->el->num_values].length = strlen(name);
+
+    op->el->values = val;
+    op->el->num_values++;
+
+    return LDB_SUCCESS;
+}
+
+
+/* add operation */
+
+/* An add operation is quite simple.
+ * First of all a new object cannot yet have parents, so the only memberof
+ * attribute that can be added to any member contains just one object DN.
+ *
+ * The real add operation is done first, to assure nothing else fails.
+ * Then we list all members of the object just created, and for each member
+ * we create an "add operation" and we pass it a parent list of one member
+ * (the object we just added again).
+ *
+ * For each add operation we lookup the object we want to operate on.
+ * We take the list of memberof attributes and sort out which parents are
+ * still missing from the parent list we have provided.
+ * We modify the object memberof attributes to reflect the new memberships.
+ * Then we list all members of this object, and for each once again we create
+ * an "add operation" as we did in the initial object.
+ *
+ * Processing stops when the target object does not have members or when it
+ * already has all the parents (can happen if nested groups create loops).
+ *
+ * Group cache unrolling:
+ * Every time we add a memberof attribute to an actual user object,
+ * we proceed to store the user name.
+ *
+ * At the end we will add a memberuid attribute to our new object that
+ * includes all direct and indeirect user members names.
+ */
+
+static int mbof_append_addop(struct mbof_add_ctx *add_ctx,
+                             struct mbof_dn_array *parents,
+                             struct ldb_dn *entry_dn)
+{
+    struct mbof_add_operation *lastop = NULL;
+    struct mbof_add_operation *addop;
+
+    /* test if this is a duplicate */
+    /* FIXME: this is not efficient */
+    if (add_ctx->add_list) {
+        do {
+            if (lastop) {
+                lastop = lastop->next;
+            } else {
+                lastop = add_ctx->add_list;
+            }
+
+            /* FIXME: check if this is right, might have to compare parents */
+            if (ldb_dn_compare(lastop->entry_dn, entry_dn) == 0) {
+                /* duplicate found */
+                return LDB_SUCCESS;
+            }
+        } while (lastop->next);
+    }
+
+    addop = talloc_zero(add_ctx, struct mbof_add_operation);
+    if (!addop) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    addop->add_ctx = add_ctx;
+    addop->parents = parents;
+    addop->entry_dn = entry_dn;
+
+    if (add_ctx->add_list) {
+        lastop->next = addop;
+    } else {
+        add_ctx->add_list = addop;
+    }
+
+    return LDB_SUCCESS;
+}
+
+static int memberof_recompute_task(struct ldb_module *module,
+                                   struct ldb_request *req);
+
+static int mbof_add_callback(struct ldb_request *req,
+                             struct ldb_reply *ares);
+static int mbof_next_add(struct mbof_add_operation *addop);
+static int mbof_next_add_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares);
+static int mbof_add_operation(struct mbof_add_operation *addop);
+static int mbof_add_missing(struct mbof_add_ctx *add_ctx, struct ldb_dn *dn);
+static int mbof_add_cleanup(struct mbof_add_ctx *add_ctx);
+static int mbof_add_cleanup_callback(struct ldb_request *req,
+                                     struct ldb_reply *ares);
+static int mbof_add_muop(struct mbof_add_ctx *add_ctx);
+static int mbof_add_muop_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares);
+
+static int memberof_add(struct ldb_module *module, struct ldb_request *req)
+{
+    struct ldb_context *ldb = ldb_module_get_ctx(module);
+    struct mbof_add_ctx *add_ctx;
+    struct mbof_ctx *ctx;
+    struct ldb_request *add_req;
+    struct ldb_message_element *el;
+    struct mbof_dn_array *parents;
+    struct ldb_dn *valdn;
+    int i, ret;
+
+    if (ldb_dn_is_special(req->op.add.message->dn)) {
+
+        if (strcmp("@MEMBEROF-REBUILD",
+                   ldb_dn_get_linearized(req->op.add.message->dn)) == 0) {
+            return memberof_recompute_task(module, req);
+        }
+
+        /* do not manipulate other control entries */
+        return ldb_next_request(module, req);
+    }
+
+    /* check if memberof is specified */
+    el = ldb_msg_find_element(req->op.add.message, DB_MEMBEROF);
+    if (el) {
+        ldb_debug(ldb, LDB_DEBUG_ERROR,
+                  "Error: the memberof attribute is readonly.");
+        return LDB_ERR_UNWILLING_TO_PERFORM;
+    }
+
+    /* check if memberuid is specified */
+    el = ldb_msg_find_element(req->op.add.message, DB_MEMBERUID);
+    if (el) {
+        ldb_debug(ldb, LDB_DEBUG_ERROR,
+                  "Error: the memberuid attribute is readonly.");
+        return LDB_ERR_UNWILLING_TO_PERFORM;
+    }
+
+    ctx = mbof_init(module, req);
+    if (!ctx) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    add_ctx = talloc_zero(ctx, struct mbof_add_ctx);
+    if (!add_ctx) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    add_ctx->ctx = ctx;
+
+    add_ctx->msg = ldb_msg_copy(add_ctx, req->op.add.message);
+    if (!add_ctx->msg) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    add_ctx->msg_dn = add_ctx->msg->dn;
+
+    /* continue with normal ops if there are no members */
+    el = ldb_msg_find_element(add_ctx->msg, DB_MEMBER);
+    if (!el) {
+        add_ctx->terminate = true;
+        goto done;
+    }
+
+    parents = talloc_zero(add_ctx, struct mbof_dn_array);
+    if (!parents) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    parents->dns = talloc_array(parents, struct ldb_dn *, 1);
+    if (!parents->dns) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    parents->dns[0] = add_ctx->msg_dn;
+    parents->num = 1;
+
+    /* process new members */
+    /* check we are not adding ourselves as member as well */
+    for (i = 0; i < el->num_values; i++) {
+        valdn = ldb_dn_from_ldb_val(add_ctx, ldb, &el->values[i]);
+        if (!valdn || !ldb_dn_validate(valdn)) {
+            ldb_debug(ldb, LDB_DEBUG_ERROR, "Invalid dn value: [%s]",
+                                            (const char *)el->values[i].data);
+            return LDB_ERR_INVALID_DN_SYNTAX;
+        }
+        if (ldb_dn_compare(valdn, req->op.add.message->dn) == 0) {
+            ldb_debug(ldb, LDB_DEBUG_ERROR,
+                      "Adding self as member is not permitted! Skipping");
+            continue;
+        }
+        ret = mbof_append_addop(add_ctx, parents, valdn);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+    }
+
+done:
+    /* add original object */
+    ret = ldb_build_add_req(&add_req, ldb, add_ctx,
+                            add_ctx->msg, req->controls,
+                            add_ctx, mbof_add_callback,
+                            req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_next_request(module, add_req);
+}
+
+static int mbof_add_callback(struct ldb_request *req,
+                             struct ldb_reply *ares)
+{
+    struct mbof_add_ctx *add_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    add_ctx = talloc_get_type(req->context, struct mbof_add_ctx);
+    ctx = add_ctx->ctx;
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        /* shouldn't happen */
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        if (add_ctx->terminate) {
+            return ldb_module_done(ctx->req,
+                                   ctx->ret_ctrls,
+                                   ctx->ret_resp,
+                                   LDB_SUCCESS);
+        }
+
+        if (add_ctx->current_op == NULL) {
+            /* first operation */
+            ctx->ret_ctrls = talloc_steal(ctx, ares->controls);
+            ctx->ret_resp = talloc_steal(ctx, ares->response);
+            ret = mbof_next_add(add_ctx->add_list);
+        }
+        else if (add_ctx->current_op->next) {
+            /* next operation */
+            ret = mbof_next_add(add_ctx->current_op->next);
+        }
+        else {
+            /* no more operations */
+            if (add_ctx->missing) {
+                ret = mbof_add_cleanup(add_ctx);
+            }
+            else if (add_ctx->muops) {
+                ret = mbof_add_muop(add_ctx);
+            }
+            else {
+                return ldb_module_done(ctx->req,
+                                       ctx->ret_ctrls,
+                                       ctx->ret_resp,
+                                       LDB_SUCCESS);
+            }
+        }
+
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_next_add(struct mbof_add_operation *addop)
+{
+    static const char *attrs[] = { DB_OC, DB_NAME,
+                                   DB_MEMBER, DB_MEMBEROF, NULL };
+    struct ldb_context *ldb;
+    struct ldb_request *req;
+    struct mbof_add_ctx *add_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    add_ctx = addop->add_ctx;
+    ctx = add_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    /* mark the operation as being handled */
+    add_ctx->current_op = addop;
+
+    ret = ldb_build_search_req(&req, ldb, ctx,
+                               addop->entry_dn, LDB_SCOPE_BASE,
+                               NULL, attrs, NULL,
+                               addop, mbof_next_add_callback,
+                               ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_request(ldb, req);
+}
+
+static int mbof_next_add_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares)
+{
+    struct mbof_add_operation *addop;
+    struct mbof_add_ctx *add_ctx;
+    struct ldb_context *ldb;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    addop = talloc_get_type(req->context, struct mbof_add_operation);
+    add_ctx = addop->add_ctx;
+    ctx = add_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        if (addop->entry != NULL) {
+            ldb_debug(ldb, LDB_DEBUG_TRACE,
+                           "Found multiple entries for (%s)",
+                           ldb_dn_get_linearized(addop->entry_dn));
+            /* more than one entry per dn ?? db corrupted ? */
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        addop->entry = talloc_steal(addop, ares->message);
+        if (addop->entry == NULL) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        break;
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        talloc_zfree(ares);
+        if (addop->entry == NULL) {
+            ldb_debug(ldb, LDB_DEBUG_TRACE, "Entry not found (%s)",
+                           ldb_dn_get_linearized(addop->entry_dn));
+
+            /* this target does not exists, save as missing */
+            ret = mbof_add_missing(add_ctx, addop->entry_dn);
+            if (ret != LDB_SUCCESS) {
+                return ldb_module_done(ctx->req, NULL, NULL, ret);
+            }
+            /* now try the next operation */
+            if (add_ctx->current_op->next) {
+                ret = mbof_next_add(add_ctx->current_op->next);
+            }
+            else {
+                /* no more operations */
+                if (add_ctx->missing) {
+                    ret = mbof_add_cleanup(add_ctx);
+                }
+                else if (add_ctx->muops) {
+                    ret = mbof_add_muop(add_ctx);
+                }
+                else {
+                    return ldb_module_done(ctx->req,
+                                           ctx->ret_ctrls,
+                                           ctx->ret_resp,
+                                           LDB_SUCCESS);
+                }
+            }
+            if (ret != LDB_SUCCESS) {
+                return ldb_module_done(ctx->req, NULL, NULL, ret);
+            }
+        }
+        else {
+            ret = mbof_add_operation(addop);
+            if (ret != LDB_SUCCESS) {
+                return ldb_module_done(ctx->req, NULL, NULL, ret);
+            }
+        }
+        return LDB_SUCCESS;
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+/* if it is a group, add all members for cascade effect
+ * add memberof attribute to this entry
+ */
+static int mbof_add_operation(struct mbof_add_operation *addop)
+{
+
+    TALLOC_CTX *tmp_ctx;
+    struct mbof_ctx *ctx;
+    struct mbof_add_ctx *add_ctx;
+    struct ldb_context *ldb;
+    struct ldb_message_element *el;
+    struct ldb_request *mod_req;
+    struct ldb_message *msg;
+    struct ldb_dn *elval_dn;
+    struct ldb_dn *valdn;
+    struct mbof_dn_array *parents;
+    int i, j, ret;
+    const char *val;
+    const char *name;
+
+    add_ctx = addop->add_ctx;
+    ctx = add_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    parents = talloc_zero(add_ctx, struct mbof_dn_array);
+    if (!parents) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    /* can't be more than the immediate parent */
+    parents->dns = talloc_array(parents, struct ldb_dn *,
+                                addop->parents->num);
+    if (!parents->dns) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    /* create new parent set for this entry */
+    for (i = 0; i < addop->parents->num; i++) {
+        /* never add yourself as memberof */
+        if (ldb_dn_compare(addop->parents->dns[i], addop->entry_dn) == 0) {
+            continue;
+        }
+        parents->dns[parents->num] = addop->parents->dns[i];
+        parents->num++;
+    }
+
+    /* remove entries that are already there */
+    el = ldb_msg_find_element(addop->entry, DB_MEMBEROF);
+    if (el) {
+
+        tmp_ctx = talloc_new(addop);
+        if (!tmp_ctx) return LDB_ERR_OPERATIONS_ERROR;
+
+        for (i = 0; i < el->num_values; i++) {
+            elval_dn = ldb_dn_from_ldb_val(tmp_ctx, ldb, &el->values[i]);
+            if (!elval_dn) {
+                ldb_debug(ldb, LDB_DEBUG_TRACE, "Invalid DN in memberof [%s]",
+                                            (const char *)el->values[i].data);
+                talloc_free(tmp_ctx);
+                return LDB_ERR_OPERATIONS_ERROR;
+            }
+            for (j = 0; j < parents->num; j++) {
+                if (ldb_dn_compare(parents->dns[j], elval_dn) == 0) {
+                    /* duplicate found */
+                    break;
+                }
+            }
+            if (j < parents->num) {
+                /* remove duplicate */
+                for (;j+1 < parents->num; j++) {
+                    parents->dns[j] = parents->dns[j+1];
+                }
+                parents->num--;
+            }
+        }
+
+        if (parents->num == 0) {
+            /* already contains all parents as memberof, skip to next */
+            talloc_free(tmp_ctx);
+            talloc_free(addop->entry);
+            addop->entry = NULL;
+
+            if (addop->next) {
+                return mbof_next_add(addop->next);
+            }
+            else if (add_ctx->muops) {
+                return mbof_add_muop(add_ctx);
+            }
+            else {
+                /* that was the last entry, get out */
+                return ldb_module_done(ctx->req,
+                                       ctx->ret_ctrls,
+                                       ctx->ret_resp,
+                                       LDB_SUCCESS);
+            }
+        }
+        talloc_free(tmp_ctx);
+    }
+
+    /* if it is a group add all members */
+    el = ldb_msg_find_element(addop->entry, DB_MEMBER);
+    if (el) {
+        for (i = 0; i < el->num_values; i++) {
+            valdn = ldb_dn_from_ldb_val(add_ctx, ldb, &el->values[i]);
+            if (!valdn) {
+                ldb_debug(ldb, LDB_DEBUG_TRACE, "Invalid DN in member [%s]",
+                                            (const char *)el->values[i].data);
+                return LDB_ERR_OPERATIONS_ERROR;
+            }
+            if (!ldb_dn_validate(valdn)) {
+                ldb_debug(ldb, LDB_DEBUG_TRACE,
+                               "Invalid DN syntax for member [%s]",
+                                            (const char *)el->values[i].data);
+                return LDB_ERR_INVALID_DN_SYNTAX;
+            }
+            ret = mbof_append_addop(add_ctx, parents, valdn);
+            if (ret != LDB_SUCCESS) {
+                return ret;
+            }
+        }
+    }
+
+    /* check if we need to store memberuid ops for this entry */
+    ret = entry_is_user_object(addop->entry);
+    switch (ret) {
+    case LDB_SUCCESS:
+        /* it's a user object  */
+        name = ldb_msg_find_attr_as_string(addop->entry, DB_NAME, NULL);
+        if (!name) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+
+        for (i = 0; i < parents->num; i++) {
+            ret = mbof_append_muop(add_ctx, &add_ctx->muops,
+                                   &add_ctx->num_muops,
+                                   LDB_FLAG_MOD_ADD,
+                                   parents->dns[i], name);
+            if (ret != LDB_SUCCESS) {
+                return ret;
+            }
+        }
+
+        break;
+
+    case LDB_ERR_NO_SUCH_ATTRIBUTE:
+        /* it is not a user object, continue */
+        break;
+
+    default:
+        /* an error occured, return */
+        return ret;
+    }
+
+    /* we are done with the entry now */
+    talloc_free(addop->entry);
+    addop->entry = NULL;
+
+    /* add memberof to entry */
+    msg = ldb_msg_new(addop);
+    if (!msg) return LDB_ERR_OPERATIONS_ERROR;
+
+    msg->dn = addop->entry_dn;
+
+    ret = ldb_msg_add_empty(msg, DB_MEMBEROF, LDB_FLAG_MOD_ADD, &el);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+    el->values = talloc_array(msg, struct ldb_val, parents->num);
+    if (!el->values) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    for (i = 0, j = 0; i < parents->num; i++) {
+        if (ldb_dn_compare(parents->dns[i], msg->dn) == 0) continue;
+        val = ldb_dn_get_linearized(parents->dns[i]);
+        el->values[j].length = strlen(val);
+        el->values[j].data = (uint8_t *)talloc_strdup(el->values, val);
+        if (!el->values[j].data) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+        j++;
+    }
+    el->num_values = j;
+
+    ret = ldb_build_mod_req(&mod_req, ldb, add_ctx,
+                            msg, NULL,
+                            add_ctx, mbof_add_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+    talloc_steal(mod_req, msg);
+
+    return ldb_next_request(ctx->module, mod_req);
+}
+
+static int mbof_add_missing(struct mbof_add_ctx *add_ctx, struct ldb_dn *dn)
+{
+    struct mbof_dn *mdn;
+
+    mdn = talloc(add_ctx, struct mbof_dn);
+    if (!mdn) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    mdn->dn = talloc_steal(mdn, dn);
+
+    /* add to the list */
+    mdn->next = add_ctx->missing;
+    add_ctx->missing = mdn;
+
+    return LDB_SUCCESS;
+}
+
+/* remove unexisting members and add memberuid attribute */
+static int mbof_add_cleanup(struct mbof_add_ctx *add_ctx)
+{
+    struct ldb_context *ldb;
+    struct ldb_message *msg;
+    struct ldb_request *mod_req;
+    struct ldb_message_element *el;
+    struct mbof_ctx *ctx;
+    struct mbof_dn *iter;
+    const char *val;
+    int ret, i, num;
+
+    ctx = add_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    num = 0;
+    for (iter = add_ctx->missing; iter; iter = iter->next) {
+        num++;
+    }
+    if (num == 0) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    msg = ldb_msg_new(add_ctx);
+    if (!msg) return LDB_ERR_OPERATIONS_ERROR;
+
+    msg->dn = add_ctx->msg_dn;
+
+    ret = ldb_msg_add_empty(msg, DB_MEMBER, LDB_FLAG_MOD_DELETE, &el);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+    el->values = talloc_array(msg, struct ldb_val, num);
+    if (!el->values) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    el->num_values = num;
+    for (i = 0, iter = add_ctx->missing; iter; iter = iter->next, i++) {
+        val = ldb_dn_get_linearized(iter->dn);
+        el->values[i].length = strlen(val);
+        el->values[i].data = (uint8_t *)talloc_strdup(el->values, val);
+        if (!el->values[i].data) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+    }
+
+    ret = ldb_build_mod_req(&mod_req, ldb, add_ctx,
+                            msg, NULL,
+                            add_ctx, mbof_add_cleanup_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_next_request(ctx->module, mod_req);
+}
+
+static int mbof_add_cleanup_callback(struct ldb_request *req,
+                                     struct ldb_reply *ares)
+{
+    struct mbof_add_ctx *add_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    add_ctx = talloc_get_type(req->context, struct mbof_add_ctx);
+    ctx = add_ctx->ctx;
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        /* shouldn't happen */
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        if (add_ctx->muops) {
+            ret = mbof_add_muop(add_ctx);
+        }
+        else {
+            return ldb_module_done(ctx->req,
+                                   ctx->ret_ctrls,
+                                   ctx->ret_resp,
+                                   LDB_SUCCESS);
+        }
+
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+/* add memberuid attributes to parent groups */
+static int mbof_add_muop(struct mbof_add_ctx *add_ctx)
+{
+    struct ldb_context *ldb;
+    struct ldb_message *msg;
+    struct ldb_request *mod_req;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    ctx = add_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    msg = ldb_msg_new(add_ctx);
+    if (!msg) return LDB_ERR_OPERATIONS_ERROR;
+
+    msg->dn = add_ctx->muops[add_ctx->cur_muop].dn;
+    msg->elements = add_ctx->muops[add_ctx->cur_muop].el;
+    msg->num_elements = 1;
+
+    ret = ldb_build_mod_req(&mod_req, ldb, add_ctx,
+                            msg, NULL,
+                            add_ctx, mbof_add_muop_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_next_request(ctx->module, mod_req);
+}
+
+static int mbof_add_muop_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares)
+{
+    struct mbof_add_ctx *add_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    add_ctx = talloc_get_type(req->context, struct mbof_add_ctx);
+    ctx = add_ctx->ctx;
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        /* shouldn't happen */
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        add_ctx->cur_muop++;
+        if (add_ctx->cur_muop < add_ctx->num_muops) {
+            ret = mbof_add_muop(add_ctx);
+        }
+        else {
+            return ldb_module_done(ctx->req,
+                                   ctx->ret_ctrls,
+                                   ctx->ret_resp,
+                                   LDB_SUCCESS);
+        }
+
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+
+
+
+/* delete operations */
+
+/* The implementation of delete operations is a bit more complex than an add
+ * operation. This is because we need to recompute memberships of potentially
+ * quite far descendants and we also have to account for loops and how to
+ * break them without ending in an endless loop ourselves.
+ * The difficulty is in the fact that while the member -> memberof link is
+ * direct, memberof -> member is not as membership is transitive.
+ *
+ * Ok, first of all, contrary to the add operation, a delete operation
+ * involves an existing object that may have existing parents. So, first, we
+ * search  the object itself to get the original membership lists (member and
+ * memberof) for this object, and we also search for any object that has it as
+ * one of its members.
+ * Once we have the results, we store object and parents and proceed with the
+ * original operation to make sure it is valid.
+ *
+ * Once the original op returns we proceed fixing parents (parents being each
+ * object that has the delete operation target object as member), if any.
+ *
+ * For each parent we retrieved we proceed to delete the member attribute that
+ * points to the object we just deleted. Once done for all parents (or if no
+ * parents exists), we proceed with the children and descendants.
+ *
+ * To handle the children we create a first ancestor operation that reflects
+ * the delete we just made. We set as parents of this object the parents just
+ * retrieved with the first search. Then we create a remove list.
+ *
+ * The remove list contains all objects in the original memberof list and the
+ * object dn itself of the original delete operation target object (the first
+ * ancestor).
+ *
+ * An operation is identified by an object that contains a tree of
+ * descendants:
+ * The remove list for the children, the immediate parent, and the dn and
+ * entry of the object this operation is about.
+ *
+ * We now proceed with adding a new operation for each original member of the
+ * first ancestor.
+ *
+ * In each operation we must first lookup the target object and each immediate
+ * parent (all the objects in the tree that have target as a "member").
+ *
+ * Then we proceed to calculate the new memberof list that we are going to set
+ * on the target object.
+ * The new memberof list starts with including all the objects that have the
+ * target as their direct member.
+ * Finally for each entry in this provisional new memberof list we add all its
+ * memberof elements to the new memberof list (taking care of excluding
+ * duplicates). This way we are certain all direct and indirect membership are
+ * accounted for.
+ *
+ * At this point we have the final new memberof list for this operation and we
+ * can proceed to modify the entry.
+ *
+ * Once the entry has been modified we proceed again to check if there are any
+ * children of this entry (the entry has "member"s).
+ * We create a new remove list that is the difference between the original
+ * entry memberof list and the new memberof list we just stored back in the
+ * object.
+ * Then for each member we create a new operation.
+ *
+ * We continue to process operations until no new operations need to be
+ * performed.
+ *
+ * Ordering is important here, se the mbof_del_get_next() function to
+ * understand how we proceed to select which new operation to process.
+ *
+ * As a final operation remove any memberuid corresponding to a removal of
+ * a memberof field from a user entry
+ */
+
+static int mbof_del_search_callback(struct ldb_request *req,
+                                    struct ldb_reply *ares);
+static int mbof_orig_del(struct mbof_del_ctx *ctx);
+static int mbof_orig_del_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares);
+static int mbof_del_cleanup_parents(struct mbof_del_ctx *del_ctx);
+static int mbof_del_clean_par_callback(struct ldb_request *req,
+                                       struct ldb_reply *ares);
+static int mbof_del_cleanup_children(struct mbof_del_ctx *del_ctx);
+static int mbof_append_delop(struct mbof_del_operation *parent,
+                             struct ldb_dn *entry_dn);
+static int mbof_del_execute_op(struct mbof_del_operation *delop);
+static int mbof_del_exop_search_callback(struct ldb_request *req,
+                                         struct ldb_reply *ares);
+static int mbof_del_execute_cont(struct mbof_del_operation *delop);
+static int mbof_del_ancestors(struct mbof_del_operation *delop);
+static int mbof_del_anc_callback(struct ldb_request *req,
+                                 struct ldb_reply *ares);
+static int mbof_del_mod_entry(struct mbof_del_operation *delop);
+static int mbof_del_mod_callback(struct ldb_request *req,
+                                 struct ldb_reply *ares);
+static int mbof_del_progeny(struct mbof_del_operation *delop);
+static int mbof_del_get_next(struct mbof_del_operation *delop,
+                             struct mbof_del_operation **nextop);
+static int mbof_del_fill_muop(struct mbof_del_ctx *del_ctx,
+                              struct ldb_message *entry);
+static int mbof_del_muop(struct mbof_del_ctx *ctx);
+static int mbof_del_muop_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares);
+
+
+static int memberof_del(struct ldb_module *module, struct ldb_request *req)
+{
+    static const char *attrs[] = { DB_OC, DB_NAME,
+                                   DB_MEMBER, DB_MEMBEROF, NULL };
+    struct ldb_context *ldb = ldb_module_get_ctx(module);
+    struct mbof_del_operation *first;
+    struct ldb_request *search;
+    char *expression;
+    const char *dn;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    if (ldb_dn_is_special(req->op.del.dn)) {
+        /* do not manipulate our control entries */
+        return ldb_next_request(module, req);
+    }
+
+    ctx = mbof_init(module, req);
+    if (!ctx) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    del_ctx = talloc_zero(ctx, struct mbof_del_ctx);
+    if (!del_ctx) {
+        talloc_free(ctx);
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    del_ctx->ctx = ctx;
+
+    /* create first entry */
+    /* the first entry is the parent of all entries and the one where we remove
+     * member from, it does not get the same treatment as others */
+    first = talloc_zero(del_ctx, struct mbof_del_operation);
+    if (!first) {
+        talloc_free(ctx);
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    del_ctx->first = first;
+
+    first->del_ctx = del_ctx;
+    first->entry_dn = req->op.del.dn;
+
+    dn = ldb_dn_get_linearized(req->op.del.dn);
+    if (!dn) {
+        talloc_free(ctx);
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    expression = talloc_asprintf(del_ctx,
+                                 "(|(distinguishedName=%s)(%s=%s))",
+                                 dn, DB_MEMBER, dn);
+    if (!expression) {
+        talloc_free(ctx);
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    ret = ldb_build_search_req(&search, ldb, del_ctx,
+                               NULL, LDB_SCOPE_SUBTREE,
+                               expression, attrs, NULL,
+                               first, mbof_del_search_callback,
+                               req);
+    if (ret != LDB_SUCCESS) {
+        talloc_free(ctx);
+        return ret;
+    }
+
+    return ldb_request(ldb, search);
+}
+
+static int mbof_del_search_callback(struct ldb_request *req,
+                                    struct ldb_reply *ares)
+{
+    struct mbof_del_operation *first;
+    struct ldb_context *ldb;
+    struct ldb_message *msg;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    first = talloc_get_type(req->context, struct mbof_del_operation);
+    del_ctx = first->del_ctx;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        msg = ares->message;
+
+        if (ldb_dn_compare(msg->dn, ctx->req->op.del.dn) == 0) {
+
+            if (first->entry != NULL) {
+                /* more than one entry per dn ?? db corrupted ? */
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+
+            first->entry = talloc_steal(first, msg);
+            if (first->entry == NULL) {
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+        } else {
+            first->parents = talloc_realloc(first, first->parents,
+                                             struct ldb_message *,
+                                             first->num_parents + 1);
+            if (!first->parents) {
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+            msg = talloc_steal(first->parents, ares->message);
+            if (!msg) {
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+            first->parents[first->num_parents] = msg;
+            first->num_parents++;
+        }
+        break;
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        if (first->entry == NULL) {
+            /* this target does not exists, too bad! */
+            ldb_debug(ldb, LDB_DEBUG_TRACE,
+                           "Target entry (%s) not found",
+                           ldb_dn_get_linearized(first->entry_dn));
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_NO_SUCH_OBJECT);
+        }
+
+        /* now perform the requested delete, before proceeding further */
+        ret =  mbof_orig_del(del_ctx);
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_orig_del(struct mbof_del_ctx *del_ctx)
+{
+    struct ldb_request *del_req;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    ctx = del_ctx->ctx;
+
+    ret = ldb_build_del_req(&del_req, ldb_module_get_ctx(ctx->module),
+                            ctx->req, ctx->req->op.del.dn, NULL,
+                            del_ctx, mbof_orig_del_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_next_request(ctx->module, del_req);
+}
+
+static int mbof_orig_del_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares)
+{
+    struct ldb_context *ldb;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    del_ctx = talloc_get_type(req->context, struct mbof_del_ctx);
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    if (ares->type != LDB_REPLY_DONE) {
+        talloc_zfree(ares);
+        ldb_set_errstring(ldb, "Invalid reply type!");
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+
+    /* save real call stuff */
+    ctx->ret_ctrls = talloc_steal(ctx, ares->controls);
+    ctx->ret_resp = talloc_steal(ctx, ares->response);
+
+    /* prep following clean ops */
+    if (del_ctx->first->num_parents) {
+
+        /* if there are parents there may be memberuids to remove */
+        ret = mbof_del_fill_muop(del_ctx, del_ctx->first->entry);
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+
+        /* if there are any parents, fire a removal sequence */
+        ret = mbof_del_cleanup_parents(del_ctx);
+    }
+    else if (ldb_msg_find_element(del_ctx->first->entry, DB_MEMBER)) {
+        /* if there are any children, fire a removal sequence */
+        ret = mbof_del_cleanup_children(del_ctx);
+    }
+    /* see if there are memberuid operations to perform */
+    else if (del_ctx->muops) {
+        return mbof_del_muop(del_ctx);
+    }
+    else {
+        /* no parents nor children, end ops */
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               LDB_SUCCESS);
+    }
+    if (ret != LDB_SUCCESS) {
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req, NULL, NULL, ret);
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_del_cleanup_parents(struct mbof_del_ctx *del_ctx)
+{
+    struct mbof_del_operation *first;
+    struct mbof_ctx *ctx;
+    struct ldb_context *ldb;
+    struct ldb_request *mod_req;
+    struct ldb_message *msg;
+    struct ldb_message_element *el;
+    const char *val;
+    int ret;
+
+    first = del_ctx->first;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    msg = ldb_msg_new(first->parents);
+    if (!msg) return LDB_ERR_OPERATIONS_ERROR;
+
+    msg->dn = first->parents[first->cur_parent]->dn;
+    first->cur_parent++;
+
+    ret = ldb_msg_add_empty(msg, DB_MEMBER, LDB_FLAG_MOD_DELETE, &el);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+    el->values = talloc_array(msg, struct ldb_val, 1);
+    if (!el->values) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    val = ldb_dn_get_linearized(first->entry_dn);
+    el->values[0].length = strlen(val);
+    el->values[0].data = (uint8_t *)talloc_strdup(el->values, val);
+    if (!el->values[0].data) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    el->num_values = 1;
+
+    ret = ldb_build_mod_req(&mod_req, ldb, first->parents,
+                            msg, NULL,
+                            del_ctx, mbof_del_clean_par_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_next_request(ctx->module, mod_req);
+}
+
+static int mbof_del_clean_par_callback(struct ldb_request *req,
+                                       struct ldb_reply *ares)
+{
+    struct mbof_del_operation *first;
+    struct ldb_context *ldb;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    del_ctx = talloc_get_type(req->context, struct mbof_del_ctx);
+    first = del_ctx->first;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    if (ares->type != LDB_REPLY_DONE) {
+        talloc_zfree(ares);
+        ldb_set_errstring(ldb, "Invalid reply type!");
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+
+    if (first->num_parents > first->cur_parent) {
+        /* still parents to cleanup, go on */
+        ret = mbof_del_cleanup_parents(del_ctx);
+    }
+    else {
+        /* continue */
+        if (ldb_msg_find_element(first->entry, DB_MEMBER)) {
+            /* if there are any children, fire a removal sequence */
+            ret = mbof_del_cleanup_children(del_ctx);
+        }
+        /* see if there are memberuid operations to perform */
+        else if (del_ctx->muops) {
+            return mbof_del_muop(del_ctx);
+        }
+        else {
+            /* no children, end ops */
+            return ldb_module_done(ctx->req,
+                                   ctx->ret_ctrls,
+                                   ctx->ret_resp,
+                                   LDB_SUCCESS);
+        }
+    }
+
+    if (ret != LDB_SUCCESS) {
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req, NULL, NULL, ret);
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_del_cleanup_children(struct mbof_del_ctx *del_ctx)
+{
+    struct mbof_del_operation *first;
+    struct mbof_ctx *ctx;
+    struct ldb_context *ldb;
+    const struct ldb_message_element *el;
+    struct ldb_dn *valdn;
+    int i, ret;
+
+    first = del_ctx->first;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    el = ldb_msg_find_element(first->entry, DB_MEMBER);
+
+    /* prepare del sets */
+    for (i = 0; i < el->num_values; i++) {
+        valdn = ldb_dn_from_ldb_val(first, ldb, &el->values[i]);
+        if (!valdn || !ldb_dn_validate(valdn)) {
+            ldb_debug(ldb, LDB_DEBUG_TRACE,
+                           "Invalid dn syntax for member [%s]",
+                                        (const char *)el->values[i].data);
+            return LDB_ERR_INVALID_DN_SYNTAX;
+        }
+        ret = mbof_append_delop(first, valdn);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+    }
+
+    /* now that sets are built, start processing */
+    return mbof_del_execute_op(first->children[0]);
+}
+
+static int mbof_append_delop(struct mbof_del_operation *parent,
+                             struct ldb_dn *entry_dn)
+{
+    struct mbof_del_operation *delop;
+
+    delop = talloc_zero(parent, struct mbof_del_operation);
+    if (!delop) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    delop->del_ctx = parent->del_ctx;
+    delop->parent = parent;
+    delop->entry_dn = entry_dn;
+
+    parent->children = talloc_realloc(parent, parent->children,
+                                      struct mbof_del_operation *,
+                                      parent->num_children +1);
+    if (!parent->children) {
+        talloc_free(delop);
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    parent->children[parent->num_children] = delop;
+    parent->num_children++;
+
+    return LDB_SUCCESS;
+}
+
+static int mbof_del_execute_op(struct mbof_del_operation *delop)
+{
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    struct ldb_context *ldb;
+    struct ldb_request *search;
+    char *expression;
+    const char *dn;
+    static const char *attrs[] = { DB_OC, DB_NAME,
+                                   DB_MEMBER, DB_MEMBEROF, NULL };
+    int ret;
+
+    del_ctx = delop->del_ctx;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    /* load entry */
+    dn = ldb_dn_get_linearized(delop->entry_dn);
+    if (!dn) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    expression = talloc_asprintf(del_ctx,
+                                 "(|(distinguishedName=%s)(%s=%s))",
+                                 dn, DB_MEMBER, dn);
+    if (!expression) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    ret = ldb_build_search_req(&search, ldb, delop,
+                               NULL, LDB_SCOPE_SUBTREE,
+                               expression, attrs, NULL,
+                               delop, mbof_del_exop_search_callback,
+                               ctx->req);
+    if (ret != LDB_SUCCESS) {
+        talloc_free(ctx);
+        return ret;
+    }
+
+    return ldb_request(ldb, search);
+}
+
+static int mbof_del_exop_search_callback(struct ldb_request *req,
+                                         struct ldb_reply *ares)
+{
+    struct mbof_del_operation *delop;
+    struct mbof_del_ctx *del_ctx;
+    struct ldb_context *ldb;
+    struct mbof_ctx *ctx;
+    struct ldb_message *msg;
+    int ret;
+
+    delop = talloc_get_type(req->context, struct mbof_del_operation);
+    del_ctx = delop->del_ctx;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        msg = ares->message;
+
+        if (ldb_dn_compare(msg->dn, delop->entry_dn) == 0) {
+
+            if (delop->entry != NULL) {
+                ldb_debug(ldb, LDB_DEBUG_TRACE,
+                               "Found multiple entries for (%s)",
+                               ldb_dn_get_linearized(delop->entry_dn));
+                /* more than one entry per dn ?? db corrupted ? */
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+
+            delop->entry = talloc_steal(delop, msg);
+            if (delop->entry == NULL) {
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+        } else {
+            delop->parents = talloc_realloc(delop, delop->parents,
+                                            struct ldb_message *,
+                                            delop->num_parents + 1);
+            if (!delop->parents) {
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+            msg = talloc_steal(delop->parents, msg);
+            if (!msg) {
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+            delop->parents[delop->num_parents] = msg;
+            delop->num_parents++;
+        }
+        break;
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        if (delop->entry == NULL) {
+            /* no target, no party! */
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        /* ok process the entry */
+        ret = mbof_del_execute_cont(delop);
+
+        if (ret != LDB_SUCCESS) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_del_execute_cont(struct mbof_del_operation *delop)
+{
+    struct mbof_del_ancestors_ctx *anc_ctx;
+    struct mbof_del_operation *parent;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    struct ldb_context *ldb;
+    struct mbof_dn_array *new_list;
+    int i;
+
+    del_ctx = delop->del_ctx;
+    parent = delop->parent;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    anc_ctx = talloc_zero(delop, struct mbof_del_ancestors_ctx);
+    if (!anc_ctx) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    delop->anc_ctx = anc_ctx;
+
+    new_list = talloc_zero(anc_ctx, struct mbof_dn_array);
+    if (!new_list) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    /* at the very least we have a number of memberof elements
+     * equal to the number of objects that have this entry as
+     * direct member */
+    new_list->num = delop->num_parents;
+
+    /* attach the list to the operation */
+    delop->anc_ctx->new_list = new_list;
+    delop->anc_ctx->num_direct = new_list->num;
+
+    /* do we have any direct parent at all ? */
+    if (new_list->num == 0) {
+        /* no entries at all, entry ended up being orphaned */
+        /* skip to directly set the new memberof list for this entry */
+
+        return mbof_del_mod_entry(delop);
+    }
+
+    /* fill in the list if we have parents */
+    new_list->dns = talloc_zero_array(new_list,
+                                      struct ldb_dn *,
+                                      new_list->num);
+    if (!new_list->dns) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    for (i = 0; i < delop->num_parents; i++) {
+        new_list->dns[i] = delop->parents[i]->dn;
+    }
+
+    /* before proceeding we also need to fetch the ancestors (anew as some may
+     * have changed by preceeding operations) */
+    return mbof_del_ancestors(delop);
+}
+
+static int mbof_del_ancestors(struct mbof_del_operation *delop)
+{
+    struct mbof_del_ancestors_ctx *anc_ctx;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    struct ldb_context *ldb;
+    struct mbof_dn_array *new_list;
+    static const char *attrs[] = { DB_MEMBEROF, NULL };
+    struct ldb_request *search;
+    int ret;
+
+    del_ctx = delop->del_ctx;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+    anc_ctx = delop->anc_ctx;
+    new_list = anc_ctx->new_list;
+
+    ret = ldb_build_search_req(&search, ldb, anc_ctx,
+                               new_list->dns[anc_ctx->cur],
+                               LDB_SCOPE_BASE, NULL, attrs, NULL,
+                               delop, mbof_del_anc_callback,
+                               ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_request(ldb, search);
+}
+
+static int mbof_del_anc_callback(struct ldb_request *req,
+                                 struct ldb_reply *ares)
+{
+    struct mbof_del_ancestors_ctx *anc_ctx;
+    struct mbof_del_operation *delop;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    struct ldb_context *ldb;
+    struct ldb_message *msg;
+    const struct ldb_message_element *el;
+    struct mbof_dn_array *new_list;
+    struct ldb_dn *valdn;
+    int i, j, ret;
+
+    delop = talloc_get_type(req->context, struct mbof_del_operation);
+    del_ctx = delop->del_ctx;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+    anc_ctx = delop->anc_ctx;
+    new_list = anc_ctx->new_list;
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        msg = ares->message;
+
+        if (anc_ctx->entry != NULL) {
+            ldb_debug(ldb, LDB_DEBUG_TRACE,
+                           "Found multiple entries for (%s)",
+                           ldb_dn_get_linearized(anc_ctx->entry->dn));
+            /* more than one entry per dn ?? db corrupted ? */
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        anc_ctx->entry = talloc_steal(anc_ctx, msg);
+        if (anc_ctx->entry == NULL) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+        break;
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        if (anc_ctx->entry == NULL) {
+            /* no target, no party! */
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        /* check entry */
+        el = ldb_msg_find_element(anc_ctx->entry, DB_MEMBEROF);
+        if (el) {
+            for (i = 0; i < el->num_values; i++) {
+                valdn = ldb_dn_from_ldb_val(new_list, ldb, &el->values[i]);
+                if (!valdn) {
+                    ldb_debug(ldb, LDB_DEBUG_TRACE,
+                                   "Invalid dn for memberof: (%s)",
+                                   (const char *)el->values[i].data);
+                    return ldb_module_done(ctx->req, NULL, NULL,
+                                           LDB_ERR_OPERATIONS_ERROR);
+                }
+                for (j = 0; j < new_list->num; j++) {
+                    if (ldb_dn_compare(valdn, new_list->dns[j]) == 0)
+                        break;
+                }
+                if (j < new_list->num) {
+                    talloc_free(valdn);
+                    continue;
+                }
+                new_list->dns = talloc_realloc(new_list,
+                                               new_list->dns,
+                                               struct ldb_dn *,
+                                               new_list->num + 1);
+                if (!new_list->dns) {
+                    return ldb_module_done(ctx->req, NULL, NULL,
+                                           LDB_ERR_OPERATIONS_ERROR);
+                }
+                new_list->dns[new_list->num] = valdn;
+                new_list->num++;
+            }
+        }
+
+        /* done with this one */
+        talloc_free(anc_ctx->entry);
+        anc_ctx->entry = NULL;
+        anc_ctx->cur++;
+
+        /* check if we need to process any more */
+        if (anc_ctx->cur < anc_ctx->num_direct) {
+            /* ok process the next one */
+            ret = mbof_del_ancestors(delop);
+        } else {
+            /* ok, end of the story, proceed to modify the entry */
+            ret = mbof_del_mod_entry(delop);
+        }
+
+        if (ret != LDB_SUCCESS) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_del_mod_entry(struct mbof_del_operation *delop)
+{
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    struct ldb_context *ldb;
+    struct mbof_dn_array *new_list;
+    struct ldb_request *mod_req;
+    struct ldb_message *msg;
+    struct ldb_message_element *el;
+    struct ldb_dn **diff = NULL;
+    const char *name;
+    const char *val;
+    int i, j, k;
+    bool is_user;
+    int ret;
+
+    del_ctx = delop->del_ctx;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+    new_list = delop->anc_ctx->new_list;
+
+    /* if this is a user we need to find out which entries have been
+     * removed so that we can later schedule removal of memberuid
+     * attributes from these entries */
+    ret = entry_is_user_object(delop->entry);
+    switch (ret) {
+    case LDB_SUCCESS:
+        /* it's a user object  */
+        is_user = true;
+        break;
+    case LDB_ERR_NO_SUCH_ATTRIBUTE:
+        /* it is not a user object, continue */
+        is_user = false;
+        break;
+    default:
+        /* an error occured, return */
+        return ret;
+    }
+
+    if (is_user) {
+        /* prepare memberuid delete list */
+        /* copy all original memberof entries, and then later remove
+         * the ones that will survive in the entry */
+        el = ldb_msg_find_element(delop->entry, DB_MEMBEROF);
+        if (!el || !el->num_values) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+        diff = talloc_array(del_ctx->muops, struct ldb_dn *,
+                            el->num_values + 1);
+        if (!diff) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+        for (i = 0, j = 0; i < el->num_values; i++) {
+            diff[j] = ldb_dn_from_ldb_val(diff, ldb, &el->values[i]);
+            if (!diff[j]) {
+                return LDB_ERR_OPERATIONS_ERROR;
+            }
+            /* skip the deleted entry if this is a delete op */
+            if (!del_ctx->is_mod) {
+                if (ldb_dn_compare(del_ctx->first->entry_dn, diff[j]) == 0) {
+                    continue;
+                }
+            }
+            j++;
+        }
+        /* zero terminate array */
+        diff[j] = NULL;
+    }
+
+    /* change memberof on entry */
+    msg = ldb_msg_new(delop);
+    if (!msg) return LDB_ERR_OPERATIONS_ERROR;
+
+    msg->dn = delop->entry_dn;
+
+    if (new_list->num) {
+        ret = ldb_msg_add_empty(msg, DB_MEMBEROF, LDB_FLAG_MOD_REPLACE, &el);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+
+        el->values = talloc_array(el, struct ldb_val, new_list->num);
+        if (!el->values) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+        for (i = 0, j = 0; i < new_list->num; i++) {
+            if (ldb_dn_compare(new_list->dns[i], msg->dn) == 0)
+                continue;
+            val = ldb_dn_get_linearized(new_list->dns[i]);
+            if (!val) {
+                return LDB_ERR_OPERATIONS_ERROR;
+            }
+            el->values[j].length = strlen(val);
+            el->values[j].data = (uint8_t *)talloc_strdup(el->values, val);
+            if (!el->values[j].data) {
+                return LDB_ERR_OPERATIONS_ERROR;
+            }
+            j++;
+
+            if (is_user) {
+                /* compare the entry's original memberof list with the new
+                 * one and for each missing entry add a memberuid removal
+                 * operation */
+                for (k = 0; diff[k]; k++) {
+                    if (ldb_dn_compare(new_list->dns[i], diff[k]) == 0) {
+                        break;
+                    }
+                }
+                if (diff[k]) {
+                    talloc_zfree(diff[k]);
+                    for (; diff[k + 1]; k++) {
+                        diff[k] = diff[k + 1];
+                    }
+                    diff[k] = NULL;
+                }
+            }
+        }
+        el->num_values = j;
+
+    }
+    else {
+        ret = ldb_msg_add_empty(msg, DB_MEMBEROF, LDB_FLAG_MOD_DELETE, &el);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+    }
+
+    if (is_user && diff[0]) {
+        /* file memberuid removal operations */
+        name = ldb_msg_find_attr_as_string(delop->entry, DB_NAME, NULL);
+        if (!name) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+
+        for (i = 0; diff[i]; i++) {
+            ret = mbof_append_muop(del_ctx, &del_ctx->muops,
+                                   &del_ctx->num_muops,
+                                   LDB_FLAG_MOD_DELETE,
+                                   diff[i], name);
+            if (ret != LDB_SUCCESS) {
+                return ret;
+            }
+        }
+    }
+
+    ret = ldb_build_mod_req(&mod_req, ldb, delop,
+                            msg, NULL,
+                            delop, mbof_del_mod_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+    talloc_steal(mod_req, msg);
+
+    return ldb_next_request(ctx->module, mod_req);
+}
+
+static int mbof_del_mod_callback(struct ldb_request *req,
+                                 struct ldb_reply *ares)
+{
+    struct mbof_del_operation *delop;
+    struct mbof_del_ctx *del_ctx;
+    struct ldb_context *ldb;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    delop = talloc_get_type(req->context, struct mbof_del_operation);
+    del_ctx = delop->del_ctx;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        ldb_debug(ldb, LDB_DEBUG_TRACE, "Got an entry on a non search op ?!");
+        /* shouldn't happen */
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        talloc_zfree(ares);
+        break;
+
+    case LDB_REPLY_DONE:
+
+        ret = mbof_del_progeny(delop);
+
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+    }
+
+    return LDB_SUCCESS;
+}
+
+static int mbof_mod_add(struct mbof_mod_ctx *mod_ctx,
+                        struct mbof_dn_array *ael);
+
+static int mbof_del_progeny(struct mbof_del_operation *delop)
+{
+    struct mbof_ctx *ctx;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_del_operation *nextop;
+    const struct ldb_message_element *el;
+    struct ldb_context *ldb;
+    struct ldb_dn *valdn;
+    int i, ret;
+
+    del_ctx = delop->del_ctx;
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    /* now verify if this entry is a group and members need to be processed as
+     * well */
+
+    el = ldb_msg_find_element(delop->entry, DB_MEMBER);
+    if (el) {
+        for (i = 0; i < el->num_values; i++) {
+            valdn = ldb_dn_from_ldb_val(delop, ldb, &el->values[i]);
+            if (!valdn || !ldb_dn_validate(valdn)) {
+                ldb_debug(ldb, LDB_DEBUG_TRACE,
+                               "Invalid DN for member: (%s)",
+                               (const char *)el->values[i].data);
+                return LDB_ERR_INVALID_DN_SYNTAX;
+            }
+            ret = mbof_append_delop(delop, valdn);
+            if (ret != LDB_SUCCESS) {
+                return ret;
+            }
+        }
+    }
+
+    /* finally find the next entry to handle */
+    ret = mbof_del_get_next(delop, &nextop);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    if (nextop) {
+        return mbof_del_execute_op(nextop);
+    }
+
+    /* see if there are memberuid operations to perform */
+    if (del_ctx->muops) {
+        return mbof_del_muop(del_ctx);
+    }
+    /* see if there are follow functions to run */
+    if (del_ctx->follow_mod) {
+        return mbof_mod_add(del_ctx->follow_mod,
+                            del_ctx->follow_mod->to_add);
+    }
+
+    /* ok, no more ops, this means our job is done */
+    return ldb_module_done(ctx->req,
+                           ctx->ret_ctrls,
+                           ctx->ret_resp,
+                           LDB_SUCCESS);
+}
+
+static int mbof_del_get_next(struct mbof_del_operation *delop,
+                             struct mbof_del_operation **nextop)
+{
+    struct mbof_del_operation *top, *cop;
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    struct mbof_dn *save, *tmp;
+
+    del_ctx = delop->del_ctx;
+    ctx = del_ctx->ctx;
+
+    /* first of all, save the current delop in the history */
+    save = talloc_zero(del_ctx, struct mbof_dn);
+    if (!save) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    save->dn = delop->entry_dn;
+
+    if (del_ctx->history) {
+        tmp = del_ctx->history;
+        while (tmp->next) tmp = tmp->next;
+        tmp->next = save;
+    } else {
+        del_ctx->history = save;
+    }
+
+    /* Find next one */
+    for (top = delop; top; top = top->parent) {
+        if (top->num_children == 0 || top->next_child >= top->num_children) {
+            /* no children, go for next one */
+            continue;
+        }
+
+        while (top->next_child < top->num_children) {
+            cop = top->children[top->next_child];
+            top->next_child++;
+
+            /* verify this operation has not already been performed */
+            for (tmp = del_ctx->history; tmp; tmp = tmp->next) {
+                if (ldb_dn_compare(tmp->dn, cop->entry_dn) == 0) {
+                    break;
+                }
+            }
+            if (tmp == NULL) {
+                /* and return the current one */
+                *nextop = cop;
+                return LDB_SUCCESS;
+            }
+        }
+    }
+
+    /* we have no more ops */
+    *nextop = NULL;
+    return LDB_SUCCESS;
+}
+
+static int mbof_del_fill_muop(struct mbof_del_ctx *del_ctx,
+                              struct ldb_message *entry)
+{
+    struct ldb_message_element *el;
+    char *name;
+    int ret;
+    int i;
+
+    el = ldb_msg_find_element(entry, DB_MEMBEROF);
+    if (!el || el->num_values == 0) {
+        /* no memberof attributes ... */
+        return LDB_SUCCESS;
+    }
+
+    ret = entry_is_user_object(entry);
+    switch (ret) {
+    case LDB_SUCCESS:
+        /* it's a user object, continue */
+        break;
+
+    case LDB_ERR_NO_SUCH_ATTRIBUTE:
+        /* it is not a user object, just return */
+        return LDB_SUCCESS;
+
+    default:
+        /* an error occured, return */
+        return ret;
+    }
+
+    name = talloc_strdup(del_ctx,
+                         ldb_msg_find_attr_as_string(entry, DB_NAME, NULL));
+    if (!name) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    for (i = 0; i < el->num_values; i++) {
+        struct ldb_dn *valdn;
+
+        valdn = ldb_dn_from_ldb_val(del_ctx->muops,
+                                    ldb_module_get_ctx(del_ctx->ctx->module),
+                                    &el->values[i]);
+        if (!valdn || !ldb_dn_validate(valdn)) {
+            ldb_debug(ldb_module_get_ctx(del_ctx->ctx->module),
+                      LDB_DEBUG_ERROR,
+                      "Invalid dn value: [%s]",
+                      (const char *)el->values[i].data);
+        }
+
+        ret = mbof_append_muop(del_ctx, &del_ctx->muops,
+                               &del_ctx->num_muops,
+                               LDB_FLAG_MOD_DELETE,
+                               valdn, name);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+    }
+
+    return LDB_SUCCESS;
+}
+
+/* del memberuid attributes to parent groups */
+static int mbof_del_muop(struct mbof_del_ctx *del_ctx)
+{
+    struct ldb_context *ldb;
+    struct ldb_message *msg;
+    struct ldb_request *mod_req;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    ctx = del_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    msg = ldb_msg_new(del_ctx);
+    if (!msg) return LDB_ERR_OPERATIONS_ERROR;
+
+    msg->dn = del_ctx->muops[del_ctx->cur_muop].dn;
+    msg->elements = del_ctx->muops[del_ctx->cur_muop].el;
+    msg->num_elements = 1;
+
+    ret = ldb_build_mod_req(&mod_req, ldb, del_ctx,
+                            msg, NULL,
+                            del_ctx, mbof_del_muop_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_next_request(ctx->module, mod_req);
+}
+
+static int mbof_del_muop_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares)
+{
+    struct mbof_del_ctx *del_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    del_ctx = talloc_get_type(req->context, struct mbof_del_ctx);
+    ctx = del_ctx->ctx;
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        /* shouldn't happen */
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        del_ctx->cur_muop++;
+        if (del_ctx->cur_muop < del_ctx->num_muops) {
+            ret = mbof_del_muop(del_ctx);
+        }
+        /* see if there are follow functions to run */
+        else if (del_ctx->follow_mod) {
+            return mbof_mod_add(del_ctx->follow_mod,
+                                del_ctx->follow_mod->to_add);
+        }
+        else {
+            return ldb_module_done(ctx->req,
+                                   ctx->ret_ctrls,
+                                   ctx->ret_resp,
+                                   LDB_SUCCESS);
+        }
+
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+
+
+/* mod operation */
+
+/* A modify operation just implements either an add operation, or a delete
+ * operation or both (replace) in turn.
+ * The only difference between a modify and a pure add or a pure delete is that
+ * the object is not created a new or not completely removed, but the setup just
+ * treats it in the same way children objects are treated in a pure add or delete
+ * operation. A list of appropriate parents and objects to modify is built, then
+ * we jump directly in the add or delete code.
+ * If both add and delete are necessary, delete operations are performed first
+ * and then a followup add operation is concatenated */
+
+static int mbof_mod_callback(struct ldb_request *req,
+                             struct ldb_reply *ares);
+static int mbof_orig_mod(struct mbof_mod_ctx *mod_ctx);
+static int mbof_orig_mod_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares);
+static int mbof_mod_process(struct mbof_mod_ctx *mod_ctx, bool *done);
+static int mbof_mod_delete(struct mbof_mod_ctx *mod_ctx,
+                           struct mbof_dn_array *del);
+static int mbof_fill_dn_array(TALLOC_CTX *memctx,
+                              struct ldb_context *ldb,
+                              const struct ldb_message_element *el,
+                              struct mbof_dn_array **dn_array);
+
+static int memberof_mod(struct ldb_module *module, struct ldb_request *req)
+{
+    struct ldb_message_element *el;
+    struct mbof_mod_ctx *mod_ctx;
+    struct mbof_ctx *ctx;
+    static const char *attrs[] = {DB_MEMBER, DB_MEMBEROF, NULL};
+    struct ldb_context *ldb = ldb_module_get_ctx(module);
+    struct ldb_request *search;
+    int ret;
+
+    if (ldb_dn_is_special(req->op.mod.message->dn)) {
+        /* do not manipulate our control entries */
+        return ldb_next_request(module, req);
+    }
+
+    /* check if memberof is specified */
+    el = ldb_msg_find_element(req->op.mod.message, DB_MEMBEROF);
+    if (el) {
+        ldb_debug(ldb, LDB_DEBUG_ERROR,
+                  "Error: the memberof attribute is readonly.");
+        return LDB_ERR_UNWILLING_TO_PERFORM;
+    }
+
+    /* check if memberuid is specified */
+    el = ldb_msg_find_element(req->op.mod.message, DB_MEMBERUID);
+    if (el) {
+        ldb_debug(ldb, LDB_DEBUG_ERROR,
+                  "Error: the memberuid attribute is readonly.");
+        return LDB_ERR_UNWILLING_TO_PERFORM;
+    }
+
+    ctx = mbof_init(module, req);
+    if (!ctx) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    mod_ctx = talloc_zero(ctx, struct mbof_mod_ctx);
+    if (!mod_ctx) {
+        talloc_free(ctx);
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    mod_ctx->ctx = ctx;
+
+    mod_ctx->msg = ldb_msg_copy(mod_ctx, req->op.mod.message);
+    if (!mod_ctx->msg) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    /* continue with normal ops if there are no members */
+    el = ldb_msg_find_element(mod_ctx->msg, DB_MEMBER);
+    if (!el) {
+        mod_ctx->terminate = true;
+        return mbof_orig_mod(mod_ctx);
+    }
+
+    mod_ctx->membel = el;
+
+    /* can't do anything,
+     * must check first what's on the entry */
+    ret = ldb_build_search_req(&search, ldb, mod_ctx,
+                               mod_ctx->msg->dn, LDB_SCOPE_BASE,
+                               NULL, attrs, NULL,
+                               mod_ctx, mbof_mod_callback,
+                               req);
+    if (ret != LDB_SUCCESS) {
+        talloc_free(ctx);
+        return ret;
+    }
+
+    return ldb_request(ldb, search);
+}
+
+
+static int mbof_mod_callback(struct ldb_request *req,
+                             struct ldb_reply *ares)
+{
+    struct mbof_mod_ctx *mod_ctx;
+    struct ldb_context *ldb;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    mod_ctx = talloc_get_type(req->context, struct mbof_mod_ctx);
+    ctx = mod_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        if (mod_ctx->entry != NULL) {
+            ldb_debug(ldb, LDB_DEBUG_TRACE,
+                           "Found multiple entries for (%s)",
+                           ldb_dn_get_linearized(mod_ctx->msg->dn));
+            /* more than one entry per dn ?? db corrupted ? */
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        mod_ctx->entry = talloc_steal(mod_ctx, ares->message);
+        if (mod_ctx->entry == NULL) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+        break;
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        if (mod_ctx->entry == NULL) {
+            ldb_debug(ldb, LDB_DEBUG_TRACE, "Entry not found (%s)",
+                           ldb_dn_get_linearized(mod_ctx->msg->dn));
+            /* this target does not exists, too bad! */
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_NO_SUCH_OBJECT);
+        }
+
+        ret = mbof_orig_mod(mod_ctx);
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_orig_mod(struct mbof_mod_ctx *mod_ctx)
+{
+    struct ldb_request *mod_req;
+    struct ldb_context *ldb;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    ctx = mod_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    ret = ldb_build_mod_req(&mod_req, ldb, ctx->req,
+                            mod_ctx->msg, ctx->req->controls,
+                            mod_ctx, mbof_orig_mod_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_next_request(ctx->module, mod_req);
+}
+
+static int mbof_orig_mod_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares)
+{
+    struct ldb_context *ldb;
+    struct mbof_mod_ctx *mod_ctx;
+    struct mbof_ctx *ctx;
+    int ret;
+
+    mod_ctx = talloc_get_type(req->context, struct mbof_mod_ctx);
+    ctx = mod_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    if (ares->type != LDB_REPLY_DONE) {
+        talloc_zfree(ares);
+        ldb_debug(ldb, LDB_DEBUG_TRACE, "Invalid reply type!");
+        ldb_set_errstring(ldb, "Invalid reply type!");
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+
+    /* save real call stuff */
+    ctx->ret_ctrls = talloc_steal(ctx, ares->controls);
+    ctx->ret_resp = talloc_steal(ctx, ares->response);
+
+    if (!mod_ctx->terminate) {
+        /* next step */
+        ret = mbof_mod_process(mod_ctx, &mod_ctx->terminate);
+        if (ret != LDB_SUCCESS) {
+            talloc_zfree(ares);
+            return ldb_module_done(ctx->req, NULL, NULL, ret);
+        }
+    }
+
+    if (mod_ctx->terminate) {
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req,
+                               ctx->ret_ctrls,
+                               ctx->ret_resp,
+                               LDB_SUCCESS);
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_mod_process(struct mbof_mod_ctx *mod_ctx, bool *done)
+{
+    const struct ldb_message_element *el;
+    struct ldb_context *ldb;
+    struct mbof_ctx *ctx;
+    struct mbof_dn_array *removed;
+    struct mbof_dn_array *added;
+    int i, j, ret;
+
+    ctx = mod_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    switch (mod_ctx->membel->flags) {
+    case LDB_FLAG_MOD_ADD:
+
+        ret = mbof_fill_dn_array(mod_ctx, ldb, mod_ctx->membel, &added);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+
+        return mbof_mod_add(mod_ctx, added);
+
+    case LDB_FLAG_MOD_DELETE:
+
+        if (mod_ctx->membel->num_values == 0) {
+            el = ldb_msg_find_element(mod_ctx->entry, DB_MEMBER);
+        } else {
+            el = mod_ctx->membel;
+        }
+
+        if (!el) {
+            /* nothing to do really */
+            *done = true;
+            return LDB_SUCCESS;
+        }
+
+        ret = mbof_fill_dn_array(mod_ctx, ldb, el, &removed);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+
+        return mbof_mod_delete(mod_ctx, removed);
+
+    case LDB_FLAG_MOD_REPLACE:
+
+        removed = NULL;
+        el = ldb_msg_find_element(mod_ctx->entry, DB_MEMBER);
+        if (el) {
+            ret = mbof_fill_dn_array(mod_ctx, ldb, el, &removed);
+            if (ret != LDB_SUCCESS) {
+                return ret;
+            }
+        }
+
+        added = NULL;
+        el = mod_ctx->membel;
+        if (el) {
+            ret = mbof_fill_dn_array(mod_ctx, ldb, el, &added);
+            if (ret != LDB_SUCCESS) {
+                return ret;
+            }
+        }
+
+        /* remove from arrays values that ended up unchanged */
+        if (removed && removed->num && added && added->num) {
+            for (i = 0; i < added->num; i++) {
+                for (j = 0; j < removed->num; j++) {
+                    if (ldb_dn_compare(added->dns[i], removed->dns[j]) == 0) {
+                        break;
+                    }
+                }
+                if (j < removed->num) {
+                    /* preexisting one, not removed, nor added */
+                    for (; j+1 < removed->num; j++) {
+                        removed->dns[j] = removed->dns[j+1];
+                    }
+                    removed->num--;
+                    for (j = i; j+1 < added->num; j++) {
+                        added->dns[j] = added->dns[j+1];
+                    }
+                    added->num--;
+                }
+            }
+        }
+
+        /* if we need to add something put it away so that it
+         * can be done after all delete operations are over */
+        if (added && added->num) {
+            mod_ctx->to_add = added;
+        }
+
+        /* if we have something to remove do it first */
+        if (removed && removed->num) {
+            return mbof_mod_delete(mod_ctx, removed);
+        }
+
+        /* if there is nothing to remove and we have stuff to add
+         * do it right away */
+        if (mod_ctx->to_add) {
+            return mbof_mod_add(mod_ctx, added);
+        }
+
+        /* the replacement function resulted in a null op,
+         * nothing to do, return happily */
+        *done = true;
+        return LDB_SUCCESS;
+    }
+
+    return LDB_ERR_OPERATIONS_ERROR;
+}
+
+static int mbof_mod_add(struct mbof_mod_ctx *mod_ctx,
+                        struct mbof_dn_array *ael)
+{
+    const struct ldb_message_element *el;
+    struct mbof_dn_array *parents;
+    struct mbof_add_ctx *add_ctx;
+    struct ldb_context *ldb;
+    struct mbof_ctx *ctx;
+    int i, ret;
+
+    ctx = mod_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    el = ldb_msg_find_element(mod_ctx->entry, DB_MEMBEROF);
+
+    /* all the parents + itself */
+    ret = mbof_fill_dn_array(mod_ctx, ldb, el, &parents);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    parents->dns = talloc_realloc(parents, parents->dns,
+                                  struct ldb_dn *, parents->num + 1);
+    if (!parents->dns) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    parents->dns[parents->num] = mod_ctx->entry->dn;
+    parents->num++;
+
+    add_ctx = talloc_zero(mod_ctx, struct mbof_add_ctx);
+    if (!add_ctx) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    add_ctx->ctx = ctx;
+    add_ctx->msg_dn = mod_ctx->msg->dn;
+
+    for (i = 0; i < ael->num; i++) {
+        ret = mbof_append_addop(add_ctx, parents, ael->dns[i]);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+    }
+
+    return mbof_next_add(add_ctx->add_list);
+}
+
+static int mbof_mod_delete(struct mbof_mod_ctx *mod_ctx,
+                           struct mbof_dn_array *del)
+{
+    struct mbof_del_operation *first;
+    struct mbof_del_ctx *del_ctx;
+    struct ldb_context *ldb;
+    struct mbof_ctx *ctx;
+    int i, ret;
+
+    ctx = mod_ctx->ctx;
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    del_ctx = talloc_zero(mod_ctx, struct mbof_del_ctx);
+    if (!del_ctx) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    del_ctx->ctx = ctx;
+    del_ctx->is_mod = true;
+
+    /* create first entry */
+    /* the first entry is the parent of all entries and the one where we
+     * remove member from, it does not get the same treatment as others */
+    first = talloc_zero(del_ctx, struct mbof_del_operation);
+    if (!first) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    del_ctx->first = first;
+
+    first->del_ctx = del_ctx;
+    first->entry = mod_ctx->entry;
+    first->entry_dn = mod_ctx->entry->dn;
+
+    /* prepare del sets */
+    for (i = 0; i < del->num; i++) {
+        ret = mbof_append_delop(first, del->dns[i]);
+        if (ret != LDB_SUCCESS) {
+            return ret;
+        }
+    }
+
+    /* add followup function if we also have stuff to add */
+    if (mod_ctx->to_add) {
+        del_ctx->follow_mod = mod_ctx;
+    }
+
+    /* now that sets are built, start processing */
+    return mbof_del_execute_op(first->children[0]);
+}
+
+static int mbof_fill_dn_array(TALLOC_CTX *memctx,
+                              struct ldb_context *ldb,
+                              const struct ldb_message_element *el,
+                              struct mbof_dn_array **dn_array)
+{
+    struct mbof_dn_array *ar;
+    struct ldb_dn *valdn;
+    int i;
+
+    ar = talloc_zero(memctx, struct mbof_dn_array);
+    if (!ar) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    *dn_array = ar;
+
+    if (!el || el->num_values == 0) {
+        return LDB_SUCCESS;
+    }
+
+    ar->dns = talloc_array(ar, struct ldb_dn *, el->num_values);
+    if (!ar->dns) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    ar->num = el->num_values;
+
+    for (i = 0; i < ar->num; i++) {
+        valdn = ldb_dn_from_ldb_val(ar, ldb, &el->values[i]);
+        if (!valdn || !ldb_dn_validate(valdn)) {
+            ldb_debug(ldb, LDB_DEBUG_TRACE, "Invalid dn value: [%s]",
+                                            (const char *)el->values[i].data);
+            return LDB_ERR_INVALID_DN_SYNTAX;
+        }
+        ar->dns[i] = valdn;
+    }
+
+    return LDB_SUCCESS;
+}
+
+
+/*************************
+ * Cleanup task routines *
+ *************************/
+
+struct mbof_member {
+    struct mbof_member *prev;
+    struct mbof_member *next;
+
+    struct ldb_dn *dn;
+    const char *name;
+    bool orig_has_memberof;
+    bool orig_has_memberuid;
+    struct ldb_message_element *orig_members;
+
+    struct mbof_member **members;
+
+    hash_table_t *memberofs;
+
+    struct ldb_message_element *memuids;
+
+    enum { MBOF_GROUP_TO_DO = 0,
+           MBOF_GROUP_DONE,
+           MBOF_USER,
+           MBOF_ITER_ERROR } status;
+};
+
+struct mbof_rcmp_context {
+    struct ldb_module *module;
+    struct ldb_request *req;
+
+    struct mbof_member *user_list;
+    hash_table_t *user_table;
+
+    struct mbof_member *group_list;
+    hash_table_t *group_table;
+};
+
+static void *hash_alloc(const size_t size, void *pvt)
+{
+    return talloc_size(pvt, size);
+}
+
+static void hash_free(void *ptr, void *pvt)
+{
+    talloc_free(ptr);
+}
+
+static int mbof_steal_msg_el(TALLOC_CTX *memctx,
+                             const char *name,
+                             struct ldb_message *msg,
+                             struct ldb_message_element **_dest)
+{
+    struct ldb_message_element *src;
+    struct ldb_message_element *dest;
+
+    src = ldb_msg_find_element(msg, name);
+    if (!src) {
+        return LDB_ERR_NO_SUCH_ATTRIBUTE;
+    }
+
+    dest = talloc_zero(memctx, struct ldb_message_element);
+    if (!dest) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    *dest = *src;
+    talloc_steal(dest, dest->name);
+    talloc_steal(dest, dest->values);
+
+    *_dest = dest;
+    return LDB_SUCCESS;
+}
+
+static int mbof_rcmp_usr_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares);
+static int mbof_rcmp_search_groups(struct mbof_rcmp_context *ctx);
+static int mbof_rcmp_grp_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares);
+static int mbof_member_update(struct mbof_rcmp_context *ctx,
+                              struct mbof_member *parent,
+                              struct mbof_member *mem);
+static bool mbof_member_iter(hash_entry_t *item, void *user_data);
+static int mbof_add_memuid(struct mbof_member *grp, const char *user);
+static int mbof_rcmp_update(struct mbof_rcmp_context *ctx);
+static int mbof_rcmp_mod_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares);
+
+static int memberof_recompute_task(struct ldb_module *module,
+                                   struct ldb_request *req)
+{
+    struct ldb_context *ldb = ldb_module_get_ctx(module);
+    static const char *attrs[] = { DB_NAME, DB_MEMBEROF, NULL };
+    static const char *filter = "(objectclass=user)";
+    struct mbof_rcmp_context *ctx;
+    struct ldb_request *src_req;
+    int ret;
+
+    ctx = talloc_zero(req, struct mbof_rcmp_context);
+    if (!ctx) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+    ctx->module = module;
+    ctx->req = req;
+
+    ret = hash_create_ex(1024, &ctx->user_table, 0, 0, 0, 0,
+                         hash_alloc, hash_free, ctx, NULL, NULL);
+    if (ret != HASH_SUCCESS) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    ret = ldb_build_search_req(&src_req, ldb, ctx,
+                               NULL, LDB_SCOPE_SUBTREE,
+                               filter, attrs, NULL,
+                               ctx, mbof_rcmp_usr_callback, ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_request(ldb, src_req);
+}
+
+static int mbof_rcmp_usr_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares)
+{
+    struct mbof_rcmp_context *ctx;
+    struct mbof_member *usr;
+    hash_value_t value;
+    hash_key_t key;
+    const char *name;
+    int ret;
+
+    ctx = talloc_get_type(req->context, struct mbof_rcmp_context);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+
+        usr = talloc_zero(ctx, struct mbof_member);
+        if (!usr) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        usr->status = MBOF_USER;
+        usr->dn = talloc_steal(usr, ares->message->dn);
+        name = ldb_msg_find_attr_as_string(ares->message, DB_NAME, NULL);
+        if (name) {
+            usr->name = talloc_steal(usr, name);
+        }
+
+        if (ldb_msg_find_element(ares->message, DB_MEMBEROF)) {
+            usr->orig_has_memberof = true;
+        }
+
+        DLIST_ADD(ctx->user_list, usr);
+
+        key.type = HASH_KEY_STRING;
+        key.str = discard_const(ldb_dn_get_linearized(usr->dn));
+        value.type = HASH_VALUE_PTR;
+        value.ptr = usr;
+
+        ret = hash_enter(ctx->user_table, &key, &value);
+        if (ret != HASH_SUCCESS) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        break;
+
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        talloc_zfree(ares);
+
+        /* and now search groups */
+        return mbof_rcmp_search_groups(ctx);
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_rcmp_search_groups(struct mbof_rcmp_context *ctx)
+{
+    struct ldb_context *ldb = ldb_module_get_ctx(ctx->module);
+    static const char *attrs[] = { DB_MEMBEROF, DB_MEMBERUID,
+                                   DB_NAME, DB_MEMBER, NULL };
+    static const char *filter = "(objectclass=group)";
+    struct ldb_request *req;
+    int ret;
+
+    ret = hash_create_ex(1024, &ctx->group_table, 0, 0, 0, 0,
+                         hash_alloc, hash_free, ctx, NULL, NULL);
+    if (ret != HASH_SUCCESS) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+
+    ret = ldb_build_search_req(&req, ldb, ctx,
+                               NULL, LDB_SCOPE_SUBTREE,
+                               filter, attrs, NULL,
+                               ctx, mbof_rcmp_grp_callback, ctx->req);
+    if (ret != LDB_SUCCESS) {
+        return ret;
+    }
+
+    return ldb_request(ldb, req);
+}
+
+static int mbof_rcmp_grp_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares)
+{
+    struct ldb_context *ldb;
+    struct mbof_rcmp_context *ctx;
+    struct ldb_message_element *el;
+    struct mbof_member *iter;
+    struct mbof_member *grp;
+    hash_value_t value;
+    hash_key_t key;
+    const char *name;
+    int i, j;
+    int ret;
+
+    ctx = talloc_get_type(req->context, struct mbof_rcmp_context);
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+
+        grp = talloc_zero(ctx, struct mbof_member);
+        if (!grp) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        grp->status = MBOF_GROUP_TO_DO;
+        grp->dn = talloc_steal(grp, ares->message->dn);
+        grp->name = ldb_msg_find_attr_as_string(ares->message, DB_NAME, NULL);
+        name = ldb_msg_find_attr_as_string(ares->message, DB_NAME, NULL);
+        if (name) {
+            grp->name = talloc_steal(grp, name);
+        }
+
+        if (ldb_msg_find_element(ares->message, DB_MEMBEROF)) {
+            grp->orig_has_memberof = true;
+        }
+
+        if (ldb_msg_find_element(ares->message, DB_MEMBERUID)) {
+            grp->orig_has_memberuid = true;
+        }
+
+        ret = mbof_steal_msg_el(grp, DB_MEMBER,
+                                ares->message, &grp->orig_members);
+        if (ret != LDB_SUCCESS && ret != LDB_ERR_NO_SUCH_ATTRIBUTE) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        DLIST_ADD(ctx->group_list, grp);
+
+        key.type = HASH_KEY_STRING;
+        key.str = discard_const(ldb_dn_get_linearized(grp->dn));
+        value.type = HASH_VALUE_PTR;
+        value.ptr = grp;
+
+        ret = hash_enter(ctx->group_table, &key, &value);
+        if (ret != HASH_SUCCESS) {
+            return ldb_module_done(ctx->req, NULL, NULL,
+                                   LDB_ERR_OPERATIONS_ERROR);
+        }
+
+        break;
+
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        break;
+
+    case LDB_REPLY_DONE:
+        talloc_zfree(ares);
+
+        if (!ctx->group_list) {
+            /* no groups ? */
+            return ldb_module_done(ctx->req, NULL, NULL, LDB_SUCCESS);
+        }
+
+        /* for each group compute the members list */
+        for (iter = ctx->group_list; iter; iter = iter->next) {
+
+            el = iter->orig_members;
+            if (!el || el->num_values == 0) {
+                /* no members */
+                continue;
+            }
+
+            /* we have at most num_values group members */
+            iter->members = talloc_array(iter, struct mbof_member *,
+                                         el->num_values +1);
+            if (!iter->members) {
+                return ldb_module_done(ctx->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+            }
+
+            for (i = 0, j = 0; i < el->num_values; i++) {
+                key.type = HASH_KEY_STRING;
+                key.str = (char *)el->values[i].data;
+
+                ret = hash_lookup(ctx->user_table, &key, &value);
+                switch (ret) {
+                case HASH_SUCCESS:
+                    iter->members[j] = (struct mbof_member *)value.ptr;
+                    j++;
+                    break;
+
+                case HASH_ERROR_KEY_NOT_FOUND:
+                    /* not a user, see if it is a group */
+
+                    ret = hash_lookup(ctx->group_table, &key, &value);
+                    if (ret != HASH_SUCCESS) {
+                        if (ret != HASH_ERROR_KEY_NOT_FOUND) {
+                            return ldb_module_done(ctx->req, NULL, NULL,
+                                                   LDB_ERR_OPERATIONS_ERROR);
+                        }
+                    }
+                    if (ret == HASH_ERROR_KEY_NOT_FOUND) {
+                        /* not a known user, nor a known group ?
+                           give a warning an continue */
+                        ldb_debug(ldb, LDB_DEBUG_ERROR,
+                                  "member attribute [%s] has no corresponding"
+                                  " entry!", key.str);
+                        break;
+                    }
+
+                    iter->members[j] = (struct mbof_member *)value.ptr;
+                    j++;
+                    break;
+
+                default:
+                    return ldb_module_done(ctx->req, NULL, NULL,
+                                           LDB_ERR_OPERATIONS_ERROR);
+                }
+            }
+            /* terminate */
+            iter->members[j] = NULL;
+
+            talloc_zfree(iter->orig_members);
+        }
+
+        /* now generate correct memberof tables */
+        while (ctx->group_list->status == MBOF_GROUP_TO_DO) {
+
+            grp = ctx->group_list;
+
+            /* move to end of list and mark as done.
+             * NOTE: this is not efficient, but will do for now */
+            DLIST_DEMOTE(ctx->group_list, grp, struct mbof_member *);
+            grp->status = MBOF_GROUP_DONE;
+
+            /* verify if members need updating */
+            if (!grp->members) {
+                continue;
+            }
+            for (i = 0; grp->members[i]; i++) {
+                ret = mbof_member_update(ctx, grp, grp->members[i]);
+                if (ret != LDB_SUCCESS) {
+                    return ldb_module_done(ctx->req, NULL, NULL,
+                                           LDB_ERR_OPERATIONS_ERROR);
+                }
+            }
+        }
+
+        /* ok all done, now go on and modify the tree */
+        return mbof_rcmp_update(ctx);
+    }
+
+    talloc_zfree(ares);
+    return LDB_SUCCESS;
+}
+
+static int mbof_member_update(struct mbof_rcmp_context *ctx,
+                              struct mbof_member *parent,
+                              struct mbof_member *mem)
+{
+    hash_value_t value;
+    hash_key_t key;
+    int ret;
+
+    /* ignore loops */
+    if (parent == mem) return LDB_SUCCESS;
+
+    key.type = HASH_KEY_STRING;
+    key.str = discard_const(ldb_dn_get_linearized(parent->dn));
+
+    if (!mem->memberofs) {
+        ret = hash_create_ex(32, &mem->memberofs, 0, 0, 0, 0,
+                             hash_alloc, hash_free, mem, NULL, NULL);
+        if (ret != HASH_SUCCESS) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+
+        ret = HASH_ERROR_KEY_NOT_FOUND;
+
+    } else {
+
+        ret = hash_lookup(mem->memberofs, &key, &value);
+        if (ret != HASH_SUCCESS) {
+            if (ret != HASH_ERROR_KEY_NOT_FOUND) {
+                /* fatal error */
+                return LDB_ERR_OPERATIONS_ERROR;
+            }
+        }
+    }
+
+    if (ret == HASH_ERROR_KEY_NOT_FOUND) {
+
+        /* it's missing, update member */
+        value.type = HASH_VALUE_PTR;
+        value.ptr = parent;
+
+        ret = hash_enter(mem->memberofs, &key, &value);
+        if (ret != HASH_SUCCESS) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+
+        if (mem->status == MBOF_USER) {
+            /* add corresponding memuid to the group */
+            ret = mbof_add_memuid(parent, mem->name);
+            if (ret != LDB_SUCCESS) {
+                return ret;
+            }
+        }
+
+        /* if we updated a group, mark it as TO DO again */
+        if (mem->status == MBOF_GROUP_DONE) {
+            mem->status = MBOF_GROUP_TO_DO;
+        }
+    }
+
+    /* now see if the parent has memberofs to pass down */
+    if (parent->memberofs) {
+        ret = hash_iterate(parent->memberofs, mbof_member_iter, mem);
+        if (ret != HASH_SUCCESS) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+        if (mem->status == MBOF_ITER_ERROR) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+    }
+
+    /* finally, if it was made TO DO move it to the head */
+    if (mem->status == MBOF_GROUP_TO_DO) {
+        DLIST_PROMOTE(ctx->group_list, mem);
+    }
+
+    return LDB_SUCCESS;
+}
+
+static bool mbof_member_iter(hash_entry_t *item, void *user_data)
+{
+    struct mbof_member *parent;
+    struct mbof_member *mem;
+    hash_value_t value;
+    int ret;
+
+    mem = talloc_get_type(user_data, struct mbof_member);
+
+    /* exclude self */
+    if (strcmp(item->key.str, ldb_dn_get_linearized(mem->dn)) == 0) {
+        return true;
+    }
+
+    /* check if we already have it */
+    ret = hash_lookup(mem->memberofs, &item->key, &value);
+    if (ret != HASH_SUCCESS) {
+        if (ret != HASH_ERROR_KEY_NOT_FOUND) {
+            /* fatal error */
+            mem->status = MBOF_ITER_ERROR;
+            return false;
+        }
+
+        /* was not already here, add it and mark group as TO DO */
+        ret = hash_enter(mem->memberofs, &item->key, &item->value);
+        if (ret != HASH_SUCCESS) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+
+        if (mem->status == MBOF_GROUP_DONE) {
+            mem->status = MBOF_GROUP_TO_DO;
+        }
+
+        if (mem->status == MBOF_USER) {
+            /* add corresponding memuid to the group */
+            parent = (struct mbof_member *)item->value.ptr;
+            ret = mbof_add_memuid(parent, mem->name);
+            if (ret != LDB_SUCCESS) {
+                mem->status = MBOF_ITER_ERROR;
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+static int mbof_add_memuid(struct mbof_member *grp, const char *user)
+{
+    struct ldb_val *vals;
+    int n;
+
+    if (!grp->memuids) {
+        grp->memuids = talloc_zero(grp, struct ldb_message_element);
+        if (!grp->memuids) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+
+        grp->memuids->name = talloc_strdup(grp->memuids, DB_MEMBERUID);
+        if (!grp->memuids->name) {
+            return LDB_ERR_OPERATIONS_ERROR;
+        }
+    }
+
+    n = grp->memuids->num_values;
+    vals = talloc_realloc(grp->memuids,
+                          grp->memuids->values,
+                          struct ldb_val, n + 1);
+    if (!vals) {
+        return LDB_ERR_OPERATIONS_ERROR;
+    }
+
+    vals[n].data = (uint8_t *)talloc_strdup(vals, user);
+    vals[n].length = strlen(user);
+
+    grp->memuids->values = vals;
+    grp->memuids->num_values = n + 1;
+
+    return LDB_SUCCESS;
+}
+
+static int mbof_rcmp_update(struct mbof_rcmp_context *ctx)
+{
+    struct ldb_context *ldb = ldb_module_get_ctx(ctx->module);
+    struct ldb_message_element *el;
+    struct ldb_message *msg = NULL;
+    struct ldb_request *req;
+    struct mbof_member *x = NULL;
+    hash_key_t *keys;
+    unsigned long count;
+    int flags;
+    int ret, i;
+
+    /* we process all users first and then all groups */
+    if (ctx->user_list) {
+        /* take the next entry and remove it from the list */
+        x = ctx->user_list;
+        DLIST_REMOVE(ctx->user_list, x);
+    }
+    else if (ctx->group_list) {
+        /* take the next entry and remove it from the list */
+        x = ctx->group_list;
+        DLIST_REMOVE(ctx->group_list, x);
+    }
+    else {
+        /* processing terminated, return */
+        ret = LDB_SUCCESS;
+        goto done;
+    }
+
+    msg = ldb_msg_new(ctx);
+    if (!msg) {
+        ret = LDB_ERR_OPERATIONS_ERROR;
+        goto done;
+    }
+
+    msg->dn = x->dn;
+
+    /* process memberof */
+    if (x->memberofs) {
+        ret = hash_keys(x->memberofs, &count, &keys);
+        if (ret != HASH_SUCCESS) {
+            ret = LDB_ERR_OPERATIONS_ERROR;
+            goto done;
+        }
+
+        if (x->orig_has_memberof) {
+            flags = LDB_FLAG_MOD_REPLACE;
+        } else {
+            flags = LDB_FLAG_MOD_ADD;
+        }
+
+        ret = ldb_msg_add_empty(msg, DB_MEMBEROF, flags, &el);
+        if (ret != LDB_SUCCESS) {
+            goto done;
+        }
+
+        el->values = talloc_array(el, struct ldb_val, count);
+        if (!el->values) {
+            ret = LDB_ERR_OPERATIONS_ERROR;
+            goto done;
+        }
+        el->num_values = count;
+
+        for (i = 0; i < count; i++) {
+            el->values[i].data = (uint8_t *)keys[i].str;
+            el->values[i].length = strlen(keys[i].str);
+        }
+    } else if (x->orig_has_memberof) {
+        ret = ldb_msg_add_empty(msg, DB_MEMBEROF, LDB_FLAG_MOD_DELETE, NULL);
+        if (ret != LDB_SUCCESS) {
+            goto done;
+        }
+    }
+
+    /* process memberuid */
+    if (x->memuids) {
+        if (x->orig_has_memberuid) {
+            flags = LDB_FLAG_MOD_REPLACE;
+        } else {
+            flags = LDB_FLAG_MOD_ADD;
+        }
+
+        ret = ldb_msg_add(msg, x->memuids, flags);
+        if (ret != LDB_SUCCESS) {
+            goto done;
+        }
+    }
+    else if (x->orig_has_memberuid) {
+        ret = ldb_msg_add_empty(msg, DB_MEMBERUID, LDB_FLAG_MOD_DELETE, NULL);
+        if (ret != LDB_SUCCESS) {
+            goto done;
+        }
+    }
+
+    ret = ldb_build_mod_req(&req, ldb, ctx, msg, NULL,
+                            ctx, mbof_rcmp_mod_callback,
+                            ctx->req);
+    if (ret != LDB_SUCCESS) {
+        goto done;
+    }
+    talloc_steal(req, msg);
+
+    /* fire next call */
+    return ldb_next_request(ctx->module, req);
+
+done:
+    /* all users and groups have been processed */
+    return ldb_module_done(ctx->req, NULL, NULL, ret);
+}
+
+static int mbof_rcmp_mod_callback(struct ldb_request *req,
+                                  struct ldb_reply *ares)
+{
+    struct ldb_context *ldb;
+    struct mbof_rcmp_context *ctx;
+
+    ctx = talloc_get_type(req->context, struct mbof_rcmp_context);
+    ldb = ldb_module_get_ctx(ctx->module);
+
+    if (!ares) {
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    }
+    if (ares->error != LDB_SUCCESS) {
+        return ldb_module_done(ctx->req,
+                               ares->controls,
+                               ares->response,
+                               ares->error);
+    }
+
+    switch (ares->type) {
+    case LDB_REPLY_ENTRY:
+        ldb_debug(ldb, LDB_DEBUG_TRACE, "Got an entry on a non search op ?!");
+        /* shouldn't happen */
+        talloc_zfree(ares);
+        return ldb_module_done(ctx->req, NULL, NULL,
+                               LDB_ERR_OPERATIONS_ERROR);
+    case LDB_REPLY_REFERRAL:
+        /* ignore */
+        talloc_zfree(ares);
+        break;
+
+    case LDB_REPLY_DONE:
+        talloc_zfree(ares);
+
+        /* update the next one */
+        return mbof_rcmp_update(ctx);
+    }
+
+    return LDB_SUCCESS;
+}
+
+
+
+/* module init code */
+
+static int memberof_init(struct ldb_module *module)
+{
+    struct ldb_context *ldb = ldb_module_get_ctx(module);
+    int ret;
+
+    /* set syntaxes for member and memberof so that comparisons in filters and
+     * such are done right */
+    ret = ldb_schema_attribute_add(ldb, DB_MEMBER, 0, LDB_SYNTAX_DN);
+    ret = ldb_schema_attribute_add(ldb, DB_MEMBEROF, 0, LDB_SYNTAX_DN);
+
+    return ldb_next_init(module);
+}
+
+const struct ldb_module_ops ldb_memberof_module_ops = {
+    .name = "memberof",
+    .init_context = memberof_init,
+    .add = memberof_add,
+    .modify = memberof_mod,
+    .del = memberof_del,
+};