nsswitch/winbind_nss_aix: reimplement fetching the SID of a user

[Samba.git] / source4 / lib / messaging / messaging.c

/*
   Unix SMB/CIFS implementation.

   Samba internal messaging functions

   Copyright (C) Andrew Tridgell 2004

   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 "lib/events/events.h"
#include "lib/util/server_id.h"
#include "system/filesys.h"
#include "messaging/messaging.h"
#include "messaging/messaging_internal.h"
#include "../lib/util/dlinklist.h"
#include "lib/socket/socket.h"
#include "librpc/gen_ndr/ndr_irpc.h"
#include "lib/messaging/irpc.h"
#include "../lib/util/unix_privs.h"
#include "librpc/rpc/dcerpc.h"
#include "cluster/cluster.h"
#include "../lib/util/tevent_ntstatus.h"
#include "lib/param/param.h"
#include "lib/util/server_id_db.h"
#include "lib/util/talloc_report.h"
#include "../source3/lib/messages_dgm.h"
#include "../source3/lib/messages_dgm_ref.h"
#include "../source3/lib/messages_util.h"
#include <tdb.h>

/* change the message version with any incompatible changes in the protocol */
#define IMESSAGING_VERSION 1

/*
  a pending irpc call
*/
struct irpc_request {
        struct imessaging_context *msg_ctx;
        int callid;
        struct {
                void (*handler)(struct irpc_request *irpc, struct irpc_message *m);
                void *private_data;
        } incoming;
};

/* we have a linked list of dispatch handlers for each msg_type that
   this messaging server can deal with */
struct dispatch_fn {
        struct dispatch_fn *next, *prev;
        uint32_t msg_type;
        void *private_data;
        msg_callback_t fn;
};

/* an individual message */

static void irpc_handler(struct imessaging_context *, void *,
                         uint32_t, struct server_id, DATA_BLOB *);


/*
 A useful function for testing the message system.
*/
static void ping_message(struct imessaging_context *msg, void *private_data,
                         uint32_t msg_type, struct server_id src, DATA_BLOB *data)
{
        struct server_id_buf idbuf;
        DEBUG(1,("INFO: Received PING message from server %s [%.*s]\n",
                 server_id_str_buf(src, &idbuf), (int)data->length,
                 data->data?(const char *)data->data:""));
        imessaging_send(msg, src, MSG_PONG, data);
}

static void pool_message(struct imessaging_context *msg, void *private_data,
                         uint32_t msg_type, struct server_id src,
                         DATA_BLOB *data)
{
        char *report;

        report = talloc_report_str(msg, NULL);

        if (report != NULL) {
                DATA_BLOB blob = { .data = (uint8_t *)report,
                                   .length = talloc_get_size(report) - 1};
                imessaging_send(msg, src, MSG_POOL_USAGE, &blob);
        }
        talloc_free(report);
}

static void ringbuf_log_msg(struct imessaging_context *msg,
                            void *private_data,
                            uint32_t msg_type,
                            struct server_id src,
                            DATA_BLOB *data)
{
        char *log = debug_get_ringbuf();
        size_t logsize = debug_get_ringbuf_size();
        DATA_BLOB blob;

        if (log == NULL) {
                log = discard_const_p(char, "*disabled*\n");
                logsize = strlen(log) + 1;
        }

        blob.data = (uint8_t *)log;
        blob.length = logsize;

        imessaging_send(msg, src, MSG_RINGBUF_LOG, &blob);
}

/*
  return uptime of messaging server via irpc
*/
static NTSTATUS irpc_uptime(struct irpc_message *msg,
                            struct irpc_uptime *r)
{
        struct imessaging_context *ctx = talloc_get_type(msg->private_data, struct imessaging_context);
        *r->out.start_time = timeval_to_nttime(&ctx->start_time);
        return NT_STATUS_OK;
}

static struct dispatch_fn *imessaging_find_dispatch(
        struct imessaging_context *msg, uint32_t msg_type)
{
        /* temporary IDs use an idtree, the rest use a array of pointers */
        if (msg_type >= MSG_TMP_BASE) {
                return (struct dispatch_fn *)idr_find(msg->dispatch_tree,
                                                      msg_type);
        }
        if (msg_type < msg->num_types) {
                return msg->dispatch[msg_type];
        }
        return NULL;
}

/*
  Register a dispatch function for a particular message type.
*/
NTSTATUS imessaging_register(struct imessaging_context *msg, void *private_data,
                            uint32_t msg_type, msg_callback_t fn)
{
        struct dispatch_fn *d;

        /* possibly expand dispatch array */
        if (msg_type >= msg->num_types) {
                struct dispatch_fn **dp;
                uint32_t i;
                dp = talloc_realloc(msg, msg->dispatch, struct dispatch_fn *, msg_type+1);
                NT_STATUS_HAVE_NO_MEMORY(dp);
                msg->dispatch = dp;
                for (i=msg->num_types;i<=msg_type;i++) {
                        msg->dispatch[i] = NULL;
                }
                msg->num_types = msg_type+1;
        }

        d = talloc_zero(msg->dispatch, struct dispatch_fn);
        NT_STATUS_HAVE_NO_MEMORY(d);
        d->msg_type = msg_type;
        d->private_data = private_data;
        d->fn = fn;

        DLIST_ADD(msg->dispatch[msg_type], d);

        return NT_STATUS_OK;
}

/*
  register a temporary message handler. The msg_type is allocated
  above MSG_TMP_BASE
*/
NTSTATUS imessaging_register_tmp(struct imessaging_context *msg, void *private_data,
                                msg_callback_t fn, uint32_t *msg_type)
{
        struct dispatch_fn *d;
        int id;

        d = talloc_zero(msg->dispatch, struct dispatch_fn);
        NT_STATUS_HAVE_NO_MEMORY(d);
        d->private_data = private_data;
        d->fn = fn;

        id = idr_get_new_above(msg->dispatch_tree, d, MSG_TMP_BASE, UINT16_MAX);
        if (id == -1) {
                talloc_free(d);
                return NT_STATUS_TOO_MANY_CONTEXT_IDS;
        }

        d->msg_type = (uint32_t)id;
        (*msg_type) = d->msg_type;

        return NT_STATUS_OK;
}

/*
  De-register the function for a particular message type.
*/
void imessaging_deregister(struct imessaging_context *msg, uint32_t msg_type, void *private_data)
{
        struct dispatch_fn *d, *next;

        if (msg_type >= msg->num_types) {
                d = (struct dispatch_fn *)idr_find(msg->dispatch_tree,
                                                   msg_type);
                if (!d) return;
                idr_remove(msg->dispatch_tree, msg_type);
                talloc_free(d);
                return;
        }

        for (d = msg->dispatch[msg_type]; d; d = next) {
                next = d->next;
                if (d->private_data == private_data) {
                        DLIST_REMOVE(msg->dispatch[msg_type], d);
                        talloc_free(d);
                }
        }
}

/*
*/
int imessaging_cleanup(struct imessaging_context *msg)
{
        if (!msg) {
                return 0;
        }
        return 0;
}

static void imessaging_dgm_recv(struct tevent_context *ev,
                                const uint8_t *buf, size_t buf_len,
                                int *fds, size_t num_fds,
                                void *private_data);

/* Keep a list of imessaging contexts */
static struct imessaging_context *msg_ctxs;

/*
 * A process has terminated, clean-up any names it has registered.
 */
NTSTATUS imessaging_process_cleanup(
        struct imessaging_context *msg_ctx,
        pid_t pid)
{
        struct irpc_name_records *names = NULL;
        int i = 0;
        int j = 0;
        TALLOC_CTX *mem_ctx = talloc_new(NULL);

        if (mem_ctx == NULL) {
                DBG_ERR("OOM unable to clean up messaging for process (%d)\n",
                        pid);
                return NT_STATUS_NO_MEMORY;
        }

        names = irpc_all_servers(msg_ctx, mem_ctx);
        if (names == NULL) {
                TALLOC_FREE(mem_ctx);
                return NT_STATUS_OK;
        }
        for (i = 0; i < names->num_records; i++) {
                for (j = 0; j < names->names[i]->count; j++) {
                        if (names->names[i]->ids[j].pid == pid) {
                                int ret = server_id_db_prune_name(
                                        msg_ctx->names,
                                        names->names[i]->name,
                                        names->names[i]->ids[j]);
                                if (ret != 0 && ret != ENOENT) {
                                        TALLOC_FREE(mem_ctx);
                                        return map_nt_error_from_unix_common(
                                            ret);
                                }
                        }
                }
        }
        TALLOC_FREE(mem_ctx);
        return NT_STATUS_OK;
}

static int imessaging_context_destructor(struct imessaging_context *msg)
{
        DLIST_REMOVE(msg_ctxs, msg);
        TALLOC_FREE(msg->msg_dgm_ref);
        return 0;
}

/*
 * Cleanup messaging dgm contexts on a specific event context.
 *
 * We must make sure to unref all messaging_dgm_ref's *before* the
 * tevent context goes away. Only when the last ref is freed, the
 * refcounted messaging dgm context will be freed.
 */
void imessaging_dgm_unref_ev(struct tevent_context *ev)
{
        struct imessaging_context *msg = NULL;

        for (msg = msg_ctxs; msg != NULL; msg = msg->next) {
                if (msg->ev == ev) {
                        TALLOC_FREE(msg->msg_dgm_ref);
                }
        }
}

static NTSTATUS imessaging_reinit(struct imessaging_context *msg)
{
        int ret = -1;

        TALLOC_FREE(msg->msg_dgm_ref);

        msg->server_id.pid = getpid();

        msg->msg_dgm_ref = messaging_dgm_ref(msg,
                                msg->ev,
                                &msg->server_id.unique_id,
                                msg->sock_dir,
                                msg->lock_dir,
                                imessaging_dgm_recv,
                                msg,
                                &ret);

        if (msg->msg_dgm_ref == NULL) {
                DEBUG(2, ("messaging_dgm_ref failed: %s\n",
                        strerror(ret)));
                return map_nt_error_from_unix_common(ret);
        }

        server_id_db_reinit(msg->names, msg->server_id);
        return NT_STATUS_OK;
}

/*
 * Must be called after a fork.
 */
NTSTATUS imessaging_reinit_all(void)
{
        struct imessaging_context *msg = NULL;

        for (msg = msg_ctxs; msg != NULL; msg = msg->next) {
                NTSTATUS status = imessaging_reinit(msg);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }
        }
        return NT_STATUS_OK;
}

/*
  create the listening socket and setup the dispatcher
*/
static struct imessaging_context *imessaging_init_internal(TALLOC_CTX *mem_ctx,
                                           struct loadparm_context *lp_ctx,
                                           struct server_id server_id,
                                           struct tevent_context *ev)
{
        NTSTATUS status;
        struct imessaging_context *msg;
        bool ok;
        int ret;
        const char *lock_dir = NULL;
        int tdb_flags = TDB_INCOMPATIBLE_HASH | TDB_CLEAR_IF_FIRST;

        if (ev == NULL) {
                return NULL;
        }

        msg = talloc_zero(mem_ctx, struct imessaging_context);
        if (msg == NULL) {
                return NULL;
        }
        msg->ev = ev;

        talloc_set_destructor(msg, imessaging_context_destructor);

        /* create the messaging directory if needed */

        lock_dir = lpcfg_lock_directory(lp_ctx);
        if (lock_dir == NULL) {
                goto fail;
        }

        msg->sock_dir = lpcfg_private_path(msg, lp_ctx, "msg.sock");
        if (msg->sock_dir == NULL) {
                goto fail;
        }
        ok = directory_create_or_exist_strict(msg->sock_dir, geteuid(), 0700);
        if (!ok) {
                goto fail;
        }

        msg->lock_dir = lpcfg_lock_path(msg, lp_ctx, "msg.lock");
        if (msg->lock_dir == NULL) {
                goto fail;
        }
        ok = directory_create_or_exist_strict(msg->lock_dir, geteuid(), 0755);
        if (!ok) {
                goto fail;
        }

        msg->msg_dgm_ref = messaging_dgm_ref(
                msg, ev, &server_id.unique_id, msg->sock_dir, msg->lock_dir,
                imessaging_dgm_recv, msg, &ret);

        if (msg->msg_dgm_ref == NULL) {
                goto fail;
        }

        msg->server_id     = server_id;
        msg->idr           = idr_init(msg);
        if (msg->idr == NULL) {
                goto fail;
        }

        msg->dispatch_tree = idr_init(msg);
        if (msg->dispatch_tree == NULL) {
                goto fail;
        }

        msg->start_time    = timeval_current();

        tdb_flags |= lpcfg_tdb_flags(lp_ctx, 0);

        /*
         * This context holds a destructor that cleans up any names
         * registered on this context on talloc_free()
         */
        msg->names = server_id_db_init(msg, server_id, lock_dir, 0, tdb_flags);
        if (msg->names == NULL) {
                goto fail;
        }

        status = imessaging_register(msg, NULL, MSG_PING, ping_message);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }
        status = imessaging_register(msg, NULL, MSG_REQ_POOL_USAGE,
                                     pool_message);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }
        status = imessaging_register(msg, NULL, MSG_IRPC, irpc_handler);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }
        status = imessaging_register(msg, NULL, MSG_REQ_RINGBUF_LOG,
                                     ringbuf_log_msg);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }
        status = IRPC_REGISTER(msg, irpc, IRPC_UPTIME, irpc_uptime, msg);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }
#if defined(DEVELOPER) || defined(ENABLE_SELFTEST)
        /*
         * Register handlers for messages specific to developer and
         * self test builds
         */
        status = imessaging_register_extra_handlers(msg);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }
#endif /* defined(DEVELOPER) || defined(ENABLE_SELFTEST) */

        DLIST_ADD(msg_ctxs, msg);

        return msg;
fail:
        talloc_free(msg);
        return NULL;
}

struct imessaging_post_state {
        struct imessaging_context *msg_ctx;
        struct imessaging_post_state **busy_ref;
        size_t buf_len;
        uint8_t buf[];
};

static int imessaging_post_state_destructor(struct imessaging_post_state *state)
{
        if (state->busy_ref != NULL) {
                *state->busy_ref = NULL;
                state->busy_ref = NULL;
        }
        return 0;
}

static void imessaging_post_handler(struct tevent_context *ev,
                                    struct tevent_immediate *ti,
                                    void *private_data)
{
        struct imessaging_post_state *state = talloc_get_type_abort(
                private_data, struct imessaging_post_state);

        /*
         * In usecases like using messaging_client_init() with irpc processing
         * we may free the imessaging_context during the messaging handler.
         * imessaging_post_state is a child of imessaging_context and
         * might be implicitly free'ed before the explicit TALLOC_FREE(state).
         *
         * The busy_ref pointer makes sure the destructor clears
         * the local 'state' variable.
         */

        SMB_ASSERT(state->busy_ref == NULL);
        state->busy_ref = &state;

        imessaging_dgm_recv(ev, state->buf, state->buf_len, NULL, 0,
                            state->msg_ctx);

        if (state == NULL) {
                return;
        }

        state->busy_ref = NULL;
        TALLOC_FREE(state);
}

static int imessaging_post_self(struct imessaging_context *msg,
                                const uint8_t *buf, size_t buf_len)
{
        struct tevent_immediate *ti;
        struct imessaging_post_state *state;

        state = talloc_size(
                msg, offsetof(struct imessaging_post_state, buf) + buf_len);
        if (state == NULL) {
                return ENOMEM;
        }
        talloc_set_name_const(state, "struct imessaging_post_state");

        talloc_set_destructor(state, imessaging_post_state_destructor);

        ti = tevent_create_immediate(state);
        if (ti == NULL) {
                TALLOC_FREE(state);
                return ENOMEM;
        }

        state->msg_ctx = msg;
        state->busy_ref = NULL;
        state->buf_len = buf_len;
        memcpy(state->buf, buf, buf_len);

        tevent_schedule_immediate(ti, msg->ev, imessaging_post_handler,
                                  state);

        return 0;
}

static void imessaging_dgm_recv(struct tevent_context *ev,
                                const uint8_t *buf, size_t buf_len,
                                int *fds, size_t num_fds,
                                void *private_data)
{
        struct imessaging_context *msg = talloc_get_type_abort(
                private_data, struct imessaging_context);
        uint32_t msg_type;
        struct server_id src, dst;
        struct server_id_buf srcbuf, dstbuf;
        DATA_BLOB data;

        if (buf_len < MESSAGE_HDR_LENGTH) {
                /* Invalid message, ignore */
                return;
        }

        if (num_fds != 0) {
                /*
                 * Source4 based messaging does not expect fd's yet
                 */
                return;
        }

        if (ev != msg->ev) {
                int ret;
                ret = imessaging_post_self(msg, buf, buf_len);
                if (ret != 0) {
                        DBG_WARNING("imessaging_post_self failed: %s\n",
                                    strerror(ret));
                }
                return;
        }

        message_hdr_get(&msg_type, &src, &dst, buf);

        data.data = discard_const_p(uint8_t, buf + MESSAGE_HDR_LENGTH);
        data.length = buf_len - MESSAGE_HDR_LENGTH;

        if ((cluster_id_equal(&dst, &msg->server_id)) ||
            ((dst.task_id == 0) && (msg->server_id.pid == 0))) {
                struct dispatch_fn *d, *next;

                DEBUG(10, ("%s: dst %s matches my id: %s, type=0x%x\n",
                           __func__,
                           server_id_str_buf(dst, &dstbuf),
                           server_id_str_buf(msg->server_id, &srcbuf),
                           (unsigned)msg_type));

                d = imessaging_find_dispatch(msg, msg_type);

                for (; d; d = next) {
                        next = d->next;
                        d->fn(msg, d->private_data, d->msg_type, src, &data);
                }
        } else {
                DEBUG(10, ("%s: Ignoring type=0x%x dst %s, I am %s, \n",
                           __func__, (unsigned)msg_type,
                           server_id_str_buf(dst, &dstbuf),
                           server_id_str_buf(msg->server_id, &srcbuf)));
        }
}

struct imessaging_context *imessaging_init(TALLOC_CTX *mem_ctx,
                                           struct loadparm_context *lp_ctx,
                                           struct server_id server_id,
                                           struct tevent_context *ev)
{
        if (ev == NULL) {
                return NULL;
        }

        if (tevent_context_is_wrapper(ev)) {
                /*
                 * This is really a programmer error!
                 *
                 * The main/raw tevent context should
                 * have been registered first!
                 */
                DBG_ERR("Should not be used with a wrapper tevent context\n");
                errno = EINVAL;
                return NULL;
        }

        return imessaging_init_internal(mem_ctx, lp_ctx, server_id, ev);
}

/*
   A hack, for the short term until we get 'client only' messaging in place
*/
struct imessaging_context *imessaging_client_init(TALLOC_CTX *mem_ctx,
                                                  struct loadparm_context *lp_ctx,
                                                struct tevent_context *ev)
{
        struct server_id id;
        ZERO_STRUCT(id);
        id.pid = getpid();
        id.task_id = generate_random();
        id.vnn = NONCLUSTER_VNN;

        /* This is because we are not in the s3 serverid database */
        id.unique_id = SERVERID_UNIQUE_ID_NOT_TO_VERIFY;

        return imessaging_init_internal(mem_ctx, lp_ctx, id, ev);
}
/*
  a list of registered irpc server functions
*/
struct irpc_list {
        struct irpc_list *next, *prev;
        struct GUID uuid;
        const struct ndr_interface_table *table;
        int callnum;
        irpc_function_t fn;
        void *private_data;
};


/*
  register a irpc server function
*/
NTSTATUS irpc_register(struct imessaging_context *msg_ctx,
                       const struct ndr_interface_table *table,
                       int callnum, irpc_function_t fn, void *private_data)
{
        struct irpc_list *irpc;

        /* override an existing handler, if any */
        for (irpc=msg_ctx->irpc; irpc; irpc=irpc->next) {
                if (irpc->table == table && irpc->callnum == callnum) {
                        break;
                }
        }
        if (irpc == NULL) {
                irpc = talloc(msg_ctx, struct irpc_list);
                NT_STATUS_HAVE_NO_MEMORY(irpc);
                DLIST_ADD(msg_ctx->irpc, irpc);
        }

        irpc->table   = table;
        irpc->callnum = callnum;
        irpc->fn      = fn;
        irpc->private_data = private_data;
        irpc->uuid = irpc->table->syntax_id.uuid;

        return NT_STATUS_OK;
}


/*
  handle an incoming irpc reply message
*/
static void irpc_handler_reply(struct imessaging_context *msg_ctx, struct irpc_message *m)
{
        struct irpc_request *irpc;

        irpc = (struct irpc_request *)idr_find(msg_ctx->idr, m->header.callid);
        if (irpc == NULL) return;

        irpc->incoming.handler(irpc, m);
}

/*
  send a irpc reply
*/
NTSTATUS irpc_send_reply(struct irpc_message *m, NTSTATUS status)
{
        struct ndr_push *push;
        DATA_BLOB packet;
        enum ndr_err_code ndr_err;

        m->header.status = status;

        /* setup the reply */
        push = ndr_push_init_ctx(m->ndr);
        if (push == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto failed;
        }

        m->header.flags |= IRPC_FLAG_REPLY;
        m->header.creds.token= NULL;

        /* construct the packet */
        ndr_err = ndr_push_irpc_header(push, NDR_SCALARS|NDR_BUFFERS, &m->header);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                status = ndr_map_error2ntstatus(ndr_err);
                goto failed;
        }

        ndr_err = m->irpc->table->calls[m->irpc->callnum].ndr_push(push, NDR_OUT, m->data);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                status = ndr_map_error2ntstatus(ndr_err);
                goto failed;
        }

        /* send the reply message */
        packet = ndr_push_blob(push);
        status = imessaging_send(m->msg_ctx, m->from, MSG_IRPC, &packet);
        if (!NT_STATUS_IS_OK(status)) goto failed;

failed:
        talloc_free(m);
        return status;
}

/*
  handle an incoming irpc request message
*/
static void irpc_handler_request(struct imessaging_context *msg_ctx,
                                 struct irpc_message *m)
{
        struct irpc_list *i;
        void *r;
        enum ndr_err_code ndr_err;

        for (i=msg_ctx->irpc; i; i=i->next) {
                if (GUID_equal(&i->uuid, &m->header.uuid) &&
                    i->table->syntax_id.if_version == m->header.if_version &&
                    i->callnum == m->header.callnum) {
                        break;
                }
        }

        if (i == NULL) {
                /* no registered handler for this message */
                talloc_free(m);
                return;
        }

        /* allocate space for the structure */
        r = talloc_zero_size(m->ndr, i->table->calls[m->header.callnum].struct_size);
        if (r == NULL) goto failed;

        m->ndr->flags |= LIBNDR_FLAG_REF_ALLOC;

        /* parse the request data */
        ndr_err = i->table->calls[i->callnum].ndr_pull(m->ndr, NDR_IN, r);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) goto failed;

        /* make the call */
        m->private_data= i->private_data;
        m->defer_reply = false;
        m->no_reply    = false;
        m->msg_ctx     = msg_ctx;
        m->irpc        = i;
        m->data        = r;

        m->header.status = i->fn(m, r);

        if (m->no_reply) {
                /* the server function won't ever be replying to this request */
                talloc_free(m);
                return;
        }

        if (m->defer_reply) {
                /* the server function has asked to defer the reply to later */
                talloc_steal(msg_ctx, m);
                return;
        }

        irpc_send_reply(m, m->header.status);
        return;

failed:
        talloc_free(m);
}

/*
  handle an incoming irpc message
*/
static void irpc_handler(struct imessaging_context *msg_ctx, void *private_data,
                         uint32_t msg_type, struct server_id src, DATA_BLOB *packet)
{
        struct irpc_message *m;
        enum ndr_err_code ndr_err;

        m = talloc(msg_ctx, struct irpc_message);
        if (m == NULL) goto failed;

        m->from = src;

        m->ndr = ndr_pull_init_blob(packet, m);
        if (m->ndr == NULL) goto failed;

        m->ndr->flags |= LIBNDR_FLAG_REF_ALLOC;

        ndr_err = ndr_pull_irpc_header(m->ndr, NDR_BUFFERS|NDR_SCALARS, &m->header);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) goto failed;

        if (m->header.flags & IRPC_FLAG_REPLY) {
                irpc_handler_reply(msg_ctx, m);
        } else {
                irpc_handler_request(msg_ctx, m);
        }
        return;

failed:
        talloc_free(m);
}


/*
  destroy a irpc request
*/
static int irpc_destructor(struct irpc_request *irpc)
{
        if (irpc->callid != -1) {
                idr_remove(irpc->msg_ctx->idr, irpc->callid);
                irpc->callid = -1;
        }

        return 0;
}

/*
  add a string name that this irpc server can be called on

  It will be removed from the DB either via irpc_remove_name or on
  talloc_free(msg_ctx->names).
*/
NTSTATUS irpc_add_name(struct imessaging_context *msg_ctx, const char *name)
{
        int ret;

        ret = server_id_db_add(msg_ctx->names, name);
        if (ret != 0) {
                return map_nt_error_from_unix_common(ret);
        }
        return NT_STATUS_OK;
}

static int all_servers_func(const char *name, unsigned num_servers,
                            const struct server_id *servers,
                            void *private_data)
{
        struct irpc_name_records *name_records = talloc_get_type(
                private_data, struct irpc_name_records);
        struct irpc_name_record *name_record;
        uint32_t i;

        name_records->names
                = talloc_realloc(name_records, name_records->names,
                                 struct irpc_name_record *, name_records->num_records+1);
        if (!name_records->names) {
                return -1;
        }

        name_records->names[name_records->num_records] = name_record
                = talloc(name_records->names,
                         struct irpc_name_record);
        if (!name_record) {
                return -1;
        }

        name_records->num_records++;

        name_record->name = talloc_strdup(name_record, name);
        if (!name_record->name) {
                return -1;
        }

        name_record->count = num_servers;
        name_record->ids = talloc_array(name_record, struct server_id,
                                        num_servers);
        if (name_record->ids == NULL) {
                return -1;
        }
        for (i=0;i<name_record->count;i++) {
                name_record->ids[i] = servers[i];
        }
        return 0;
}

/*
  return a list of server ids for a server name
*/
struct irpc_name_records *irpc_all_servers(struct imessaging_context *msg_ctx,
                                           TALLOC_CTX *mem_ctx)
{
        int ret;
        struct irpc_name_records *name_records = talloc_zero(mem_ctx, struct irpc_name_records);
        if (name_records == NULL) {
                return NULL;
        }

        ret = server_id_db_traverse_read(msg_ctx->names, all_servers_func,
                                         name_records);
        if (ret == -1) {
                TALLOC_FREE(name_records);
                return NULL;
        }

        return name_records;
}

/*
  remove a name from a messaging context
*/
void irpc_remove_name(struct imessaging_context *msg_ctx, const char *name)
{
        server_id_db_remove(msg_ctx->names, name);
}

struct server_id imessaging_get_server_id(struct imessaging_context *msg_ctx)
{
        return msg_ctx->server_id;
}

struct irpc_bh_state {
        struct imessaging_context *msg_ctx;
        struct server_id server_id;
        const struct ndr_interface_table *table;
        uint32_t timeout;
        struct security_token *token;
};

static bool irpc_bh_is_connected(struct dcerpc_binding_handle *h)
{
        struct irpc_bh_state *hs = dcerpc_binding_handle_data(h,
                                   struct irpc_bh_state);

        if (!hs->msg_ctx) {
                return false;
        }

        return true;
}

static uint32_t irpc_bh_set_timeout(struct dcerpc_binding_handle *h,
                                    uint32_t timeout)
{
        struct irpc_bh_state *hs = dcerpc_binding_handle_data(h,
                                   struct irpc_bh_state);
        uint32_t old = hs->timeout;

        hs->timeout = timeout;

        return old;
}

struct irpc_bh_raw_call_state {
        struct irpc_request *irpc;
        uint32_t opnum;
        DATA_BLOB in_data;
        DATA_BLOB in_packet;
        DATA_BLOB out_data;
};

static void irpc_bh_raw_call_incoming_handler(struct irpc_request *irpc,
                                              struct irpc_message *m);

static struct tevent_req *irpc_bh_raw_call_send(TALLOC_CTX *mem_ctx,
                                                struct tevent_context *ev,
                                                struct dcerpc_binding_handle *h,
                                                const struct GUID *object,
                                                uint32_t opnum,
                                                uint32_t in_flags,
                                                const uint8_t *in_data,
                                                size_t in_length)
{
        struct irpc_bh_state *hs =
                dcerpc_binding_handle_data(h,
                struct irpc_bh_state);
        struct tevent_req *req;
        struct irpc_bh_raw_call_state *state;
        bool ok;
        struct irpc_header header;
        struct ndr_push *ndr;
        NTSTATUS status;
        enum ndr_err_code ndr_err;

        req = tevent_req_create(mem_ctx, &state,
                                struct irpc_bh_raw_call_state);
        if (req == NULL) {
                return NULL;
        }
        state->opnum = opnum;
        state->in_data.data = discard_const_p(uint8_t, in_data);
        state->in_data.length = in_length;

        ok = irpc_bh_is_connected(h);
        if (!ok) {
                tevent_req_nterror(req, NT_STATUS_CONNECTION_DISCONNECTED);
                return tevent_req_post(req, ev);
        }

        state->irpc = talloc_zero(state, struct irpc_request);
        if (tevent_req_nomem(state->irpc, req)) {
                return tevent_req_post(req, ev);
        }

        state->irpc->msg_ctx  = hs->msg_ctx;
        state->irpc->callid   = idr_get_new(hs->msg_ctx->idr,
                                            state->irpc, UINT16_MAX);
        if (state->irpc->callid == -1) {
                tevent_req_nterror(req, NT_STATUS_INSUFFICIENT_RESOURCES);
                return tevent_req_post(req, ev);
        }
        state->irpc->incoming.handler = irpc_bh_raw_call_incoming_handler;
        state->irpc->incoming.private_data = req;

        talloc_set_destructor(state->irpc, irpc_destructor);

        /* setup the header */
        header.uuid = hs->table->syntax_id.uuid;

        header.if_version = hs->table->syntax_id.if_version;
        header.callid     = state->irpc->callid;
        header.callnum    = state->opnum;
        header.flags      = 0;
        header.status     = NT_STATUS_OK;
        header.creds.token= hs->token;

        /* construct the irpc packet */
        ndr = ndr_push_init_ctx(state->irpc);
        if (tevent_req_nomem(ndr, req)) {
                return tevent_req_post(req, ev);
        }

        ndr_err = ndr_push_irpc_header(ndr, NDR_SCALARS|NDR_BUFFERS, &header);
        status = ndr_map_error2ntstatus(ndr_err);
        if (!NT_STATUS_IS_OK(status)) {
                tevent_req_nterror(req, status);
                return tevent_req_post(req, ev);
        }

        ndr_err = ndr_push_bytes(ndr, in_data, in_length);
        status = ndr_map_error2ntstatus(ndr_err);
        if (!NT_STATUS_IS_OK(status)) {
                tevent_req_nterror(req, status);
                return tevent_req_post(req, ev);
        }

        /* and send it */
        state->in_packet = ndr_push_blob(ndr);
        status = imessaging_send(hs->msg_ctx, hs->server_id,
                                MSG_IRPC, &state->in_packet);
        if (!NT_STATUS_IS_OK(status)) {
                tevent_req_nterror(req, status);
                return tevent_req_post(req, ev);
        }

        if (hs->timeout != IRPC_CALL_TIMEOUT_INF) {
                /* set timeout-callback in case caller wants that */
                ok = tevent_req_set_endtime(req, ev, timeval_current_ofs(hs->timeout, 0));
                if (!ok) {
                        return tevent_req_post(req, ev);
                }
        }

        return req;
}

static void irpc_bh_raw_call_incoming_handler(struct irpc_request *irpc,
                                              struct irpc_message *m)
{
        struct tevent_req *req =
                talloc_get_type_abort(irpc->incoming.private_data,
                struct tevent_req);
        struct irpc_bh_raw_call_state *state =
                tevent_req_data(req,
                struct irpc_bh_raw_call_state);

        talloc_steal(state, m);

        if (!NT_STATUS_IS_OK(m->header.status)) {
                tevent_req_nterror(req, m->header.status);
                return;
        }

        state->out_data = data_blob_talloc(state,
                m->ndr->data + m->ndr->offset,
                m->ndr->data_size - m->ndr->offset);
        if ((m->ndr->data_size - m->ndr->offset) > 0 && !state->out_data.data) {
                tevent_req_oom(req);
                return;
        }

        tevent_req_done(req);
}

static NTSTATUS irpc_bh_raw_call_recv(struct tevent_req *req,
                                        TALLOC_CTX *mem_ctx,
                                        uint8_t **out_data,
                                        size_t *out_length,
                                        uint32_t *out_flags)
{
        struct irpc_bh_raw_call_state *state =
                tevent_req_data(req,
                struct irpc_bh_raw_call_state);
        NTSTATUS status;

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

        *out_data = talloc_move(mem_ctx, &state->out_data.data);
        *out_length = state->out_data.length;
        *out_flags = 0;
        tevent_req_received(req);
        return NT_STATUS_OK;
}

struct irpc_bh_disconnect_state {
        uint8_t _dummy;
};

static struct tevent_req *irpc_bh_disconnect_send(TALLOC_CTX *mem_ctx,
                                                struct tevent_context *ev,
                                                struct dcerpc_binding_handle *h)
{
        struct irpc_bh_state *hs = dcerpc_binding_handle_data(h,
                                     struct irpc_bh_state);
        struct tevent_req *req;
        struct irpc_bh_disconnect_state *state;
        bool ok;

        req = tevent_req_create(mem_ctx, &state,
                                struct irpc_bh_disconnect_state);
        if (req == NULL) {
                return NULL;
        }

        ok = irpc_bh_is_connected(h);
        if (!ok) {
                tevent_req_nterror(req, NT_STATUS_CONNECTION_DISCONNECTED);
                return tevent_req_post(req, ev);
        }

        hs->msg_ctx = NULL;

        tevent_req_done(req);
        return tevent_req_post(req, ev);
}

static NTSTATUS irpc_bh_disconnect_recv(struct tevent_req *req)
{
        NTSTATUS status;

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

        tevent_req_received(req);
        return NT_STATUS_OK;
}

static bool irpc_bh_ref_alloc(struct dcerpc_binding_handle *h)
{
        return true;
}

static const struct dcerpc_binding_handle_ops irpc_bh_ops = {
        .name                   = "wbint",
        .is_connected           = irpc_bh_is_connected,
        .set_timeout            = irpc_bh_set_timeout,
        .raw_call_send          = irpc_bh_raw_call_send,
        .raw_call_recv          = irpc_bh_raw_call_recv,
        .disconnect_send        = irpc_bh_disconnect_send,
        .disconnect_recv        = irpc_bh_disconnect_recv,

        .ref_alloc              = irpc_bh_ref_alloc,
};

/* initialise a irpc binding handle */
struct dcerpc_binding_handle *irpc_binding_handle(TALLOC_CTX *mem_ctx,
                                                  struct imessaging_context *msg_ctx,
                                                  struct server_id server_id,
                                                  const struct ndr_interface_table *table)
{
        struct dcerpc_binding_handle *h;
        struct irpc_bh_state *hs;

        h = dcerpc_binding_handle_create(mem_ctx,
                                         &irpc_bh_ops,
                                         NULL,
                                         table,
                                         &hs,
                                         struct irpc_bh_state,
                                         __location__);
        if (h == NULL) {
                return NULL;
        }
        hs->msg_ctx = msg_ctx;
        hs->server_id = server_id;
        hs->table = table;
        hs->timeout = IRPC_CALL_TIMEOUT;

        return h;
}

struct dcerpc_binding_handle *irpc_binding_handle_by_name(TALLOC_CTX *mem_ctx,
                                                          struct imessaging_context *msg_ctx,
                                                          const char *dest_task,
                                                          const struct ndr_interface_table *table)
{
        struct dcerpc_binding_handle *h;
        unsigned num_sids;
        struct server_id *sids;
        struct server_id sid;
        NTSTATUS status;

        /* find the server task */

        status = irpc_servers_byname(msg_ctx, mem_ctx, dest_task,
                                     &num_sids, &sids);
        if (!NT_STATUS_IS_OK(status)) {
                errno = EADDRNOTAVAIL;
                return NULL;
        }
        sid = sids[0];
        talloc_free(sids);

        h = irpc_binding_handle(mem_ctx, msg_ctx,
                                sid, table);
        if (h == NULL) {
                return NULL;
        }

        return h;
}

void irpc_binding_handle_add_security_token(struct dcerpc_binding_handle *h,
                                            struct security_token *token)
{
        struct irpc_bh_state *hs =
                dcerpc_binding_handle_data(h,
                struct irpc_bh_state);

        hs->token = token;
}