source: trunk/server/source3/winbindd/wb_lookupsids.c

/*
   Unix SMB/CIFS implementation.
   async lookupsids
   Copyright (C) Volker Lendecke 2011

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

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

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

#include "includes.h"
#include "winbindd.h"
#include "librpc/gen_ndr/ndr_wbint_c.h"
#include "../libcli/security/security.h"
#include "passdb/machine_sid.h"

struct wb_lookupsids_domain {
        struct dom_sid sid;
        struct winbindd_domain *domain;

        /*
         * Array of sids to be passed into wbint_LookupSids. Preallocated with
         * num_sids.
         */
        struct lsa_SidArray sids;

        /*
         * Indexes into wb_lookupsids_state->sids and thus
         * wb_lookupsids_state->res_names. Preallocated with num_sids.
         */
        uint32_t *sid_indexes;
};

struct wb_translated_name {
        const char *domain_name;
        const char *name;
        enum lsa_SidType type;
};

static struct wb_lookupsids_domain *wb_lookupsids_get_domain(
        const struct dom_sid *sid, TALLOC_CTX *mem_ctx,
        struct wb_lookupsids_domain **domains, uint32_t num_sids);

struct wb_lookupsids_state {
        struct tevent_context *ev;

        /*
         * SIDs passed in
         */
        struct dom_sid *sids;
        uint32_t num_sids;

        /*
         * The domains we're using for bulk lookup via wbint_LookupRids or
         * wbint_LookupSids. We expect very few domains, so we do a
         * talloc_realloc and rely on talloc_array_length.
         */
        struct wb_lookupsids_domain *domains;
        uint32_t domains_done;

        /*
         * These SIDs are looked up individually via
         * wbint_LookupSid. Preallocated with num_sids.
         */
        uint32_t *single_sids;
        uint32_t num_single_sids;
        uint32_t single_sids_done;

        /*
         * Intermediate store for wbint_LookupRids to passdb. These are
         * spliced into res_domains/res_names in wb_lookupsids_move_name.
         */
        struct wbint_RidArray rids;
        const char *domain_name;
        struct wbint_Principals rid_names;

        /*
         * Intermediate results for wbint_LookupSids. These results are
         * spliced into res_domains/res_names in wb_lookupsids_move_name.
         */
        struct lsa_RefDomainList tmp_domains;
        struct lsa_TransNameArray tmp_names;

        /*
         * Results
         */
        struct lsa_RefDomainList *res_domains;
        /*
         * Indexed as "sids" in this structure
         */
        struct lsa_TransNameArray *res_names;
};

static bool wb_lookupsids_next(struct tevent_req *req,
                               struct wb_lookupsids_state *state);
static void wb_lookupsids_single_done(struct tevent_req *subreq);
static void wb_lookupsids_lookuprids_done(struct tevent_req *subreq);
static void wb_lookupsids_done(struct tevent_req *subreq);

struct tevent_req *wb_lookupsids_send(TALLOC_CTX *mem_ctx,
                                      struct tevent_context *ev,
                                      struct dom_sid *sids,
                                      uint32_t num_sids)
{
        struct tevent_req *req;
        struct wb_lookupsids_state *state;
        uint32_t i;

        req = tevent_req_create(mem_ctx, &state, struct wb_lookupsids_state);
        if (req == NULL) {
                return NULL;
        }
        state->ev = ev;
        state->sids = sids;
        state->num_sids = num_sids;

        state->single_sids = TALLOC_ARRAY(state, uint32_t, num_sids);
        if (tevent_req_nomem(state->single_sids, req)) {
                return tevent_req_post(req, ev);
        }

        state->res_domains = TALLOC_ZERO_P(state, struct lsa_RefDomainList);
        if (tevent_req_nomem(state->res_domains, req)) {
                return tevent_req_post(req, ev);
        }
        state->res_domains->domains = TALLOC_ARRAY(
                state->res_domains, struct lsa_DomainInfo, num_sids);
        if (tevent_req_nomem(state->res_domains->domains, req)) {
                return tevent_req_post(req, ev);
        }

        state->res_names = TALLOC_ZERO_P(state, struct lsa_TransNameArray);
        if (tevent_req_nomem(state->res_names, req)) {
                return tevent_req_post(req, ev);
        }
        state->res_names->names = TALLOC_ARRAY(
                state->res_names, struct lsa_TranslatedName, num_sids);
        if (tevent_req_nomem(state->res_names->names, req)) {
                return tevent_req_post(req, ev);
        }

        if (num_sids == 0) {
                tevent_req_done(req);
                return tevent_req_post(req, ev);
        }

        for (i=0; i<num_sids; i++) {
                struct wb_lookupsids_domain *d;

                d = wb_lookupsids_get_domain(&sids[i], state, &state->domains,
                                             num_sids);
                if (d != NULL) {
                        d->sids.sids[d->sids.num_sids].sid = &sids[i];
                        d->sid_indexes[d->sids.num_sids] = i;
                        d->sids.num_sids += 1;
                } else {
                        state->single_sids[state->num_single_sids] = i;
                        state->num_single_sids += 1;
                }
        }

        if (!wb_lookupsids_next(req, state)) {
                return tevent_req_post(req, ev);
        }
        return req;
}

static bool wb_lookupsids_next(struct tevent_req *req,
                               struct wb_lookupsids_state *state)
{
        struct tevent_req *subreq;

        if (state->domains_done < talloc_array_length(state->domains)) {
                struct wb_lookupsids_domain *d;
                uint32_t i;

                d = &state->domains[state->domains_done];

                if (sid_check_is_domain(&d->sid)) {
                        state->rids.num_rids = d->sids.num_sids;
                        state->rids.rids = TALLOC_ARRAY(state, uint32_t,
                                                        state->rids.num_rids);
                        if (tevent_req_nomem(state->rids.rids, req)) {
                                return false;
                        }
                        for (i=0; i<state->rids.num_rids; i++) {
                                sid_peek_rid(d->sids.sids[i].sid,
                                             &state->rids.rids[i]);
                        }
                        subreq = dcerpc_wbint_LookupRids_send(
                                state, state->ev, dom_child_handle(d->domain),
                                &d->sid, &state->rids, &state->domain_name,
                                &state->rid_names);
                        if (tevent_req_nomem(subreq, req)) {
                                return false;
                        }
                        tevent_req_set_callback(
                                subreq, wb_lookupsids_lookuprids_done, req);
                        return true;
                }

                subreq = dcerpc_wbint_LookupSids_send(
                        state, state->ev, dom_child_handle(d->domain),
                        &d->sids, &state->tmp_domains,  &state->tmp_names);
                if (tevent_req_nomem(subreq, req)) {
                        return false;
                }
                tevent_req_set_callback(subreq, wb_lookupsids_done, req);
                return true;
        }

        if (state->single_sids_done < state->num_single_sids) {
                uint32_t sid_idx;
                const struct dom_sid *sid;

                sid_idx = state->single_sids[state->single_sids_done];
                sid = &state->sids[sid_idx];

                subreq = wb_lookupsid_send(state, state->ev, sid);
                if (tevent_req_nomem(subreq, req)) {
                        return false;
                }
                tevent_req_set_callback(subreq, wb_lookupsids_single_done,
                                        req);
                return true;
        }

        tevent_req_done(req);
        return false;
}

/*
 * Decide whether to do bulk lookupsids. We have optimizations for
 * passdb via lookuprids and to remote DCs via lookupsids.
 */

static bool wb_lookupsids_bulk(const struct dom_sid *sid)
{
        if (sid->num_auths != 5) {
                /*
                 * Only do "S-1-5-21-x-y-z-rid" domains via bulk
                 * lookup
                 */
                DEBUG(10, ("No bulk setup for SID %s with %d subauths\n",
                           sid_string_dbg(sid), sid->num_auths));
                return false;
        }

        if (sid_check_is_in_our_domain(sid)) {
                /*
                 * Passdb lookup via lookuprids
                 */
                DEBUG(10, ("%s is in our domain\n", sid_string_tos(sid)));
                return true;
        }

        if ((lp_server_role() == ROLE_DOMAIN_PDC) ||
            (lp_server_role() == ROLE_DOMAIN_BDC)) {
                /*
                 * Bulk lookups to trusted DCs
                 */
                return (find_domain_from_sid_noinit(sid) != NULL);
        }

        if (lp_server_role() != ROLE_DOMAIN_MEMBER) {
                /*
                 * Don't do bulk lookups as standalone, the only bulk
                 * lookup left is for domain members.
                 */
                return false;
        }

        if (sid_check_is_in_unix_groups(sid) ||
            sid_check_is_unix_groups(sid) ||
            sid_check_is_in_unix_users(sid) ||
            sid_check_is_unix_users(sid) ||
            sid_check_is_in_builtin(sid) ||
            sid_check_is_builtin(sid)) {
                /*
                 * These are locally done piece by piece anyway, no
                 * need for bulk optimizations.
                 */
                return false;
        }

        /*
         * All other SIDs are sent to the DC we're connected to as
         * member via a single lsa_lookupsids call.
         */
        return true;
}

static struct wb_lookupsids_domain *wb_lookupsids_get_domain(
        const struct dom_sid *sid, TALLOC_CTX *mem_ctx,
        struct wb_lookupsids_domain **pdomains, uint32_t num_sids)
{
        struct wb_lookupsids_domain *domains, *domain;
        struct winbindd_domain *wb_domain;
        uint32_t i, num_domains;

        if (!wb_lookupsids_bulk(sid)) {
                return NULL;
        }

        domains = *pdomains;
        num_domains = talloc_array_length(domains);

        for (i=0; i<num_domains; i++) {
                if (dom_sid_compare_domain(sid, &domains[i].sid) == 0) {
                        return &domains[i];
                }
        }

        wb_domain = find_domain_from_sid_noinit(sid);
        if (wb_domain == NULL) {
                return NULL;
        }

        domains = TALLOC_REALLOC_ARRAY(
                mem_ctx, domains, struct wb_lookupsids_domain, num_domains+1);
        if (domains == NULL) {
                return NULL;
        }
        *pdomains = domains;

        domain = &domains[num_domains];
        sid_copy(&domain->sid, sid);
        sid_split_rid(&domain->sid, NULL);
        domain->domain = wb_domain;

        domain->sids.sids = TALLOC_ARRAY(domains, struct lsa_SidPtr, num_sids);
        if (domains->sids.sids == NULL) {
                goto fail;
        }
        domain->sids.num_sids = 0;

        domain->sid_indexes = TALLOC_ARRAY(domains, uint32_t, num_sids);
        if (domain->sid_indexes == NULL) {
                TALLOC_FREE(domain->sids.sids);
                goto fail;
        }
        return domain;

fail:
        /*
         * Realloc to the state it was in before
         */
        *pdomains = TALLOC_REALLOC_ARRAY(
                mem_ctx, domains, struct wb_lookupsids_domain, num_domains);
        return NULL;
}

static bool wb_lookupsids_find_dom_idx(struct lsa_DomainInfo *domain,
                                       struct lsa_RefDomainList *list,
                                       uint32_t *idx)
{
        uint32_t i;
        struct lsa_DomainInfo *new_domain;

        for (i=0; i<list->count; i++) {
                if (sid_equal(domain->sid, list->domains[i].sid)) {
                        *idx = i;
                        return true;
                }
        }

        new_domain = &list->domains[list->count];

        new_domain->name.string = talloc_strdup(
                list->domains, domain->name.string);
        if (new_domain->name.string == NULL) {
                return false;
        }

        new_domain->sid = dom_sid_dup(list->domains, domain->sid);
        if (new_domain->sid == NULL) {
                return false;
        }

        *idx = list->count;
        list->count += 1;
        return true;
}

static bool wb_lookupsids_move_name(struct lsa_RefDomainList *src_domains,
                                    struct lsa_TranslatedName *src_name,
                                    struct lsa_RefDomainList *dst_domains,
                                    struct lsa_TransNameArray *dst_names,
                                    uint32_t dst_name_index)
{
        struct lsa_TranslatedName *dst_name;
        struct lsa_DomainInfo *src_domain;
        uint32_t src_domain_index, dst_domain_index;

        src_domain_index = src_name->sid_index;
        if (src_domain_index >= src_domains->count) {
                return false;
        }
        src_domain = &src_domains->domains[src_domain_index];

        if (!wb_lookupsids_find_dom_idx(
                    src_domain, dst_domains, &dst_domain_index)) {
                return false;
        }

        dst_name = &dst_names->names[dst_name_index];

        dst_name->sid_type = src_name->sid_type;
        dst_name->name.string = talloc_move(dst_names->names,
                                            &src_name->name.string);
        dst_name->sid_index = dst_domain_index;
        dst_names->count += 1;

        return true;
}

static void wb_lookupsids_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct wb_lookupsids_state *state = tevent_req_data(
                req, struct wb_lookupsids_state);
        struct wb_lookupsids_domain *d;
        uint32_t i;
        bool fallback = false;

        NTSTATUS status, result;

        status = dcerpc_wbint_LookupSids_recv(subreq, state, &result);
        TALLOC_FREE(subreq);
        if (tevent_req_nterror(req, status)) {
                return;
        }

        d = &state->domains[state->domains_done];

        if (NT_STATUS_IS_ERR(result)) {
                fallback = true;
        } else if (state->tmp_names.count != d->sids.num_sids) {
                fallback = true;
        }

        if (fallback) {
                for (i=0; i < d->sids.num_sids; i++) {
                        uint32_t res_sid_index = d->sid_indexes[i];

                        state->single_sids[state->num_single_sids] =
                                res_sid_index;
                        state->num_single_sids += 1;
                }
                state->domains_done += 1;
                wb_lookupsids_next(req, state);
                return;
        }

        /*
         * Look at the individual states in the translated names.
         */

        for (i=0; i<state->tmp_names.count; i++) {

                uint32_t res_sid_index = d->sid_indexes[i];

                if (state->tmp_names.names[i].sid_type == SID_NAME_UNKNOWN) {
                        /*
                         * Make unknown SIDs go through
                         * wb_lookupsid. This retries the forest root.
                         */
                        state->single_sids[state->num_single_sids] =
                                res_sid_index;
                        state->num_single_sids += 1;
                        continue;
                }
                if (!wb_lookupsids_move_name(
                            &state->tmp_domains, &state->tmp_names.names[i],
                            state->res_domains, state->res_names,
                            res_sid_index)) {
                        tevent_req_nomem(NULL, req);
                        return;
                }
        }
        state->domains_done += 1;
        wb_lookupsids_next(req, state);
}

static void wb_lookupsids_single_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct wb_lookupsids_state *state = tevent_req_data(
                req, struct wb_lookupsids_state);
        const char *domain_name, *name;
        enum lsa_SidType type;
        uint32_t res_sid_index;
        uint32_t src_rid;

        struct dom_sid src_domain_sid;
        struct lsa_DomainInfo src_domain;
        struct lsa_RefDomainList src_domains;
        struct lsa_TranslatedName src_name;

        NTSTATUS status;

        status = wb_lookupsid_recv(subreq, talloc_tos(), &type,
                                   &domain_name, &name);
        TALLOC_FREE(subreq);
        if (!NT_STATUS_IS_OK(status)) {
                type = SID_NAME_UNKNOWN;

                domain_name = talloc_strdup(talloc_tos(), "");
                if (tevent_req_nomem(domain_name, req)) {
                        return;
                }
                name = talloc_strdup(talloc_tos(), "");
                if (tevent_req_nomem(name, req)) {
                        return;
                }
        }

        /*
         * Fake up structs for wb_lookupsids_move_name
         */
        res_sid_index = state->single_sids[state->single_sids_done];

        sid_copy(&src_domain_sid, &state->sids[res_sid_index]);
        sid_split_rid(&src_domain_sid, &src_rid);
        src_domain.name.string = domain_name;
        src_domain.sid = &src_domain_sid;

        src_domains.count = 1;
        src_domains.domains = &src_domain;

        src_name.sid_type = type;
        src_name.name.string = name;
        src_name.sid_index = 0;

        if (!wb_lookupsids_move_name(
                    &src_domains, &src_name,
                    state->res_domains, state->res_names,
                    res_sid_index)) {
                tevent_req_nomem(NULL, req);
                return;
        }
        state->single_sids_done += 1;
        wb_lookupsids_next(req, state);
}

static void wb_lookupsids_lookuprids_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct wb_lookupsids_state *state = tevent_req_data(
                req, struct wb_lookupsids_state);
        struct dom_sid src_domain_sid;
        struct lsa_DomainInfo src_domain;
        struct lsa_RefDomainList src_domains;
        NTSTATUS status, result;
        struct wb_lookupsids_domain *d;
        uint32_t i;
        bool fallback = false;

        status = dcerpc_wbint_LookupRids_recv(subreq, state, &result);
        TALLOC_FREE(subreq);
        if (tevent_req_nterror(req, status)) {
                return;
        }

        d = &state->domains[state->domains_done];

        if (NT_STATUS_IS_ERR(result)) {
                fallback = true;
        } else if (state->rid_names.num_principals != d->sids.num_sids) {
                fallback = true;
        }

        if (fallback) {
                for (i=0; i < d->sids.num_sids; i++) {
                        uint32_t res_sid_index = d->sid_indexes[i];

                        state->single_sids[state->num_single_sids] =
                                res_sid_index;
                        state->num_single_sids += 1;
                }
                state->domains_done += 1;
                wb_lookupsids_next(req, state);
                return;
        }

        /*
         * Look at the individual states in the translated names.
         */

        sid_copy(&src_domain_sid, get_global_sam_sid());
        src_domain.name.string = get_global_sam_name();
        src_domain.sid = &src_domain_sid;
        src_domains.count = 1;
        src_domains.domains = &src_domain;

        for (i=0; i<state->rid_names.num_principals; i++) {
                struct lsa_TranslatedName src_name;
                uint32_t res_sid_index;

                /*
                 * Fake up structs for wb_lookupsids_move_name
                 */
                res_sid_index = d->sid_indexes[i];

                src_name.sid_type = state->rid_names.principals[i].type;
                src_name.name.string = state->rid_names.principals[i].name;
                src_name.sid_index = 0;

                if (!wb_lookupsids_move_name(
                            &src_domains, &src_name,
                            state->res_domains, state->res_names,
                            res_sid_index)) {
                        tevent_req_nomem(NULL, req);
                        return;
                }
        }

        state->domains_done += 1;
        wb_lookupsids_next(req, state);
}

NTSTATUS wb_lookupsids_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                            struct lsa_RefDomainList **domains,
                            struct lsa_TransNameArray **names)
{
        struct wb_lookupsids_state *state = tevent_req_data(
                req, struct wb_lookupsids_state);
        NTSTATUS status;

        if (tevent_req_is_nterror(req, &status)) {
                return status;
        }

        /*
         * The returned names need to match the given sids,
         * if not we have a bug in the code!
         *
         */
        SMB_ASSERT(state->res_names->count == state->num_sids);

        /*
         * Not strictly needed, but it might make debugging in the callers
         * easier in future, if the talloc_array_length() returns the
         * expected result...
         */
        state->res_domains->domains = talloc_realloc(state->res_domains,
                                                     state->res_domains->domains,
                                                     struct lsa_DomainInfo,
                                                     state->res_domains->count);

        *domains = talloc_move(mem_ctx, &state->res_domains);
        *names = talloc_move(mem_ctx, &state->res_names);
        return NT_STATUS_OK;
}