s3:rpc_server: call reopen_logs before we print the copyright notice

[Samba.git] / source3 / rpc_server / rpc_host.c

/*
 *  RPC host
 *
 *  Implements samba-dcerpcd service.
 *
 *  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/>.
 */

/*
 * This binary has two usage modes:
 *
 * In the normal case when invoked from smbd or winbind it is given a
 * directory to scan via --libexec-rpcds and will invoke on demand any
 * binaries it finds there starting with rpcd_ when a named pipe
 * connection is requested.
 *
 * In the second mode it can be started explicitly from system startup
 * scripts.
 *
 * When Samba is set up as an Active Directory Domain Controller the
 * normal samba binary overrides and provides DCERPC services, whilst
 * allowing samba-dcerpcd to provide the services that smbd used to
 * provide in that set-up, such as SRVSVC.
 *
 * The second mode can also be useful for use outside of the Samba framework,
 * for example, use with the Linux kernel SMB2 server ksmbd. In this mode
 * it behaves like inetd and listens on sockets on behalf of RPC server
 * implementations.
 */

#include "replace.h"
#include <fnmatch.h>
#include "lib/cmdline/cmdline.h"
#include "lib/cmdline/closefrom_except.h"
#include "source3/include/includes.h"
#include "source3/include/auth.h"
#include "rpc_sock_helper.h"
#include "messages.h"
#include "lib/util_file.h"
#include "lib/util/tevent_unix.h"
#include "lib/util/tevent_ntstatus.h"
#include "lib/util/smb_strtox.h"
#include "lib/util/debug.h"
#include "lib/util/server_id.h"
#include "lib/util/util_tdb.h"
#include "lib/tdb_wrap/tdb_wrap.h"
#include "lib/async_req/async_sock.h"
#include "librpc/rpc/dcerpc_util.h"
#include "lib/tsocket/tsocket.h"
#include "libcli/named_pipe_auth/npa_tstream.h"
#include "librpc/gen_ndr/ndr_rpc_host.h"
#include "source3/param/loadparm.h"
#include "source3/lib/global_contexts.h"
#include "lib/util/strv.h"
#include "lib/util/pidfile.h"
#include "source3/rpc_client/cli_pipe.h"
#include "librpc/gen_ndr/ndr_epmapper.h"
#include "librpc/gen_ndr/ndr_epmapper_c.h"
#include "nsswitch/winbind_client.h"
#include "libcli/security/dom_sid.h"
#include "libcli/security/security_token.h"

extern bool override_logfile;

struct rpc_server;
struct rpc_work_process;

/*
 * samba-dcerpcd state to keep track of rpcd_* servers.
 */
struct rpc_host {
        struct messaging_context *msg_ctx;
        struct rpc_server **servers;
        struct tdb_wrap *epmdb;

        int worker_stdin[2];

        bool np_helper;

        /*
         * If we're started with --np-helper but nobody contacts us,
         * we need to exit after a while. This will be deleted once
         * the first real client connects and our self-exit mechanism
         * when we don't have any worker processes left kicks in.
         */
        struct tevent_timer *np_helper_shutdown;
};

/*
 * Map a RPC interface to a name. Used when filling the endpoint
 * mapper database
 */
struct rpc_host_iface_name {
        struct ndr_syntax_id iface;
        char *name;
};

/*
 * rpc_host representation for listening sockets. ncacn_ip_tcp might
 * listen on multiple explicit IPs, all with the same port.
 */
struct rpc_host_endpoint {
        struct rpc_server *server;
        struct dcerpc_binding *binding;
        struct ndr_syntax_id *interfaces;
        int *fds;
        size_t num_fds;
};

/*
 * Staging area until we sent the socket plus bind to the helper
 */
struct rpc_host_pending_client {
        struct rpc_host_pending_client *prev, *next;

        /*
         * Pointer for the destructor to remove us from the list of
         * pending clients
         */
        struct rpc_server *server;

        /*
         * Waiter for client exit before a helper accepted the request
         */
        struct tevent_req *hangup_wait;

        /*
         * Info to pick the worker
         */
        struct ncacn_packet *bind_pkt;

        /*
         * This is what we send down to the worker
         */
        int sock;
        struct rpc_host_client *client;
};

/*
 * Representation of one worker process. For each rpcd_* executable
 * there will be more of than one of these.
 */
struct rpc_work_process {
        pid_t pid;

        /*
         * !available means:
         *
         * Worker forked but did not send its initial status yet (not
         * yet initialized)
         *
         * Worker died, but we did not receive SIGCHLD yet. We noticed
         * it because we couldn't send it a message.
         */
        bool available;

        /*
         * Incremented by us when sending a client, decremented by
         * MSG_RPC_HOST_WORKER_STATUS sent by workers whenever a
         * client exits.
         */
        uint32_t num_clients;

        /*
         * Send SHUTDOWN to an idle child after a while
         */
        struct tevent_timer *exit_timer;
};

/*
 * State for a set of running instances of an rpcd_* server executable
 */
struct rpc_server {
        struct rpc_host *host;
        /*
         * Index into the rpc_host_state->servers array
         */
        uint32_t server_index;

        const char *rpc_server_exe;

        struct rpc_host_endpoint **endpoints;
        struct rpc_host_iface_name *iface_names;

        size_t max_workers;
        size_t idle_seconds;

        /*
         * "workers" can be larger than "max_workers": Internal
         * connections require an idle worker to avoid deadlocks
         * between RPC servers: netlogon requires samr, everybody
         * requires winreg. And if a deep call in netlogon asks for a
         * samr connection, this must never end up in the same
         * process. named_pipe_auth_req_info7->need_idle_server is set
         * in those cases.
         */
        struct rpc_work_process *workers;

        struct rpc_host_pending_client *pending_clients;
};

struct rpc_server_get_endpoints_state {
        char **argl;
        char *ncalrpc_endpoint;
        enum dcerpc_transport_t only_transport;

        struct rpc_host_iface_name *iface_names;
        struct rpc_host_endpoint **endpoints;

        unsigned long num_workers;
        unsigned long idle_seconds;
};

static void rpc_server_get_endpoints_done(struct tevent_req *subreq);

/**
 * @brief Query interfaces from an rpcd helper
 *
 * Spawn a rpcd helper, ask it for the interfaces it serves via
 * --list-interfaces, parse the output
 *
 * @param[in] mem_ctx Memory context for the tevent_req
 * @param[in] ev Event context to run this on
 * @param[in] rpc_server_exe Binary to ask with --list-interfaces
 * @param[in] only_transport Filter out anything but this
 * @return The tevent_req representing this process
 */

static struct tevent_req *rpc_server_get_endpoints_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        const char *rpc_server_exe,
        enum dcerpc_transport_t only_transport)
{
        struct tevent_req *req = NULL, *subreq = NULL;
        struct rpc_server_get_endpoints_state *state = NULL;
        const char *progname = NULL;

        req = tevent_req_create(
                mem_ctx, &state, struct rpc_server_get_endpoints_state);
        if (req == NULL) {
                return NULL;
        }
        state->only_transport = only_transport;

        progname = strrchr(rpc_server_exe, '/');
        if (progname != NULL) {
                progname += 1;
        } else {
                progname = rpc_server_exe;
        }

        state->ncalrpc_endpoint = talloc_strdup(state, progname);
        if (tevent_req_nomem(state->ncalrpc_endpoint, req)) {
                return tevent_req_post(req, ev);
        }

        state->argl = talloc_array(state, char *, 4);
        if (tevent_req_nomem(state->argl, req)) {
                return tevent_req_post(req, ev);
        }

        state->argl = str_list_make_empty(state);
        str_list_add_printf(&state->argl, "%s", rpc_server_exe);
        str_list_add_printf(&state->argl, "--list-interfaces");
        str_list_add_printf(
                &state->argl, "--configfile=%s", get_dyn_CONFIGFILE());

        if (tevent_req_nomem(state->argl, req)) {
                return tevent_req_post(req, ev);
        }

        subreq = file_ploadv_send(state, ev, state->argl, 65536);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, rpc_server_get_endpoints_done, req);
        return req;
}

/*
 * Parse a line of format
 *
 * 338cd001-2244-31f1-aaaa-900038001003/0x00000001 winreg
 *
 * and add it to the "piface_names" array.
 */

static struct rpc_host_iface_name *rpc_exe_parse_iface_line(
        TALLOC_CTX *mem_ctx,
        struct rpc_host_iface_name **piface_names,
        const char *line)
{
        struct rpc_host_iface_name *iface_names = *piface_names;
        struct rpc_host_iface_name *tmp = NULL, *result = NULL;
        size_t i, num_ifaces = talloc_array_length(iface_names);
        struct ndr_syntax_id iface;
        char *name = NULL;
        bool ok;

        ok = ndr_syntax_id_from_string(line, &iface);
        if (!ok) {
                DBG_WARNING("ndr_syntax_id_from_string() failed for: [%s]\n",
                            line);
                return NULL;
        }

        name = strchr(line, ' ');
        if (name == NULL) {
                return NULL;
        }
        name += 1;

        for (i=0; i<num_ifaces; i++) {
                result = &iface_names[i];

                if (ndr_syntax_id_equal(&result->iface, &iface)) {
                        return result;
                }
        }

        if (num_ifaces + 1 < num_ifaces) {
                return NULL;
        }

        name = talloc_strdup(mem_ctx, name);
        if (name == NULL) {
                return NULL;
        }

        tmp = talloc_realloc(
                mem_ctx,
                iface_names,
                struct rpc_host_iface_name,
                num_ifaces + 1);
        if (tmp == NULL) {
                TALLOC_FREE(name);
                return NULL;
        }
        iface_names = tmp;

        result = &iface_names[num_ifaces];

        *result = (struct rpc_host_iface_name) {
                .iface = iface,
                .name = talloc_move(iface_names, &name),
        };

        *piface_names = iface_names;

        return result;
}

static struct rpc_host_iface_name *rpc_host_iface_names_find(
        struct rpc_host_iface_name *iface_names,
        const struct ndr_syntax_id *iface)
{
        size_t i, num_iface_names = talloc_array_length(iface_names);

        for (i=0; i<num_iface_names; i++) {
                struct rpc_host_iface_name *iface_name = &iface_names[i];

                if (ndr_syntax_id_equal(iface, &iface_name->iface)) {
                        return iface_name;
                }
        }

        return NULL;
}

static bool dcerpc_binding_same_endpoint(
        const struct dcerpc_binding *b1, const struct dcerpc_binding *b2)
{
        enum dcerpc_transport_t t1 = dcerpc_binding_get_transport(b1);
        enum dcerpc_transport_t t2 = dcerpc_binding_get_transport(b2);
        const char *e1 = NULL, *e2 = NULL;
        int cmp;

        if (t1 != t2) {
                return false;
        }

        e1 = dcerpc_binding_get_string_option(b1, "endpoint");
        e2 = dcerpc_binding_get_string_option(b2, "endpoint");

        if ((e1 == NULL) && (e2 == NULL)) {
                return true;
        }
        if ((e1 == NULL) || (e2 == NULL)) {
                return false;
        }
        cmp = strcmp(e1, e2);
        return (cmp == 0);
}

/**
 * @brief Filter whether we want to serve an endpoint
 *
 * samba-dcerpcd might want to serve all endpoints a rpcd reported to
 * us via --list-interfaces.
 *
 * In member mode, we only serve named pipes. Indicated by NCACN_NP
 * passed in via "only_transport".
 *
 * @param[in] binding Which binding is in question?
 * @param[in] only_transport Exclusive transport to serve
 * @return Do we want to serve "binding" from samba-dcerpcd?
 */

static bool rpc_host_serve_endpoint(
        struct dcerpc_binding *binding,
        enum dcerpc_transport_t only_transport)
{
        enum dcerpc_transport_t transport =
                dcerpc_binding_get_transport(binding);

        if (only_transport == NCA_UNKNOWN) {
                /* no filter around */
                return true;
        }

        if (transport != only_transport) {
                /* filter out */
                return false;
        }

        return true;
}

static struct rpc_host_endpoint *rpc_host_endpoint_find(
        struct rpc_server_get_endpoints_state *state,
        const char *binding_string)
{
        size_t i, num_endpoints = talloc_array_length(state->endpoints);
        struct rpc_host_endpoint **tmp = NULL, *ep = NULL;
        enum dcerpc_transport_t transport;
        NTSTATUS status;
        bool serve_this;

        ep = talloc_zero(state, struct rpc_host_endpoint);
        if (ep == NULL) {
                goto fail;
        }

        status = dcerpc_parse_binding(ep, binding_string, &ep->binding);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("dcerpc_parse_binding(%s) failed: %s\n",
                          binding_string,
                          nt_errstr(status));
                goto fail;
        }

        serve_this = rpc_host_serve_endpoint(
                ep->binding, state->only_transport);
        if (!serve_this) {
                goto fail;
        }

        transport = dcerpc_binding_get_transport(ep->binding);

        if (transport == NCALRPC) {
                const char *ncalrpc_sock = dcerpc_binding_get_string_option(
                        ep->binding, "endpoint");

                if (ncalrpc_sock == NULL) {
                        /*
                         * generic ncalrpc:, set program-specific
                         * socket name. epmapper will redirect clients
                         * properly.
                         */
                        status = dcerpc_binding_set_string_option(
                                ep->binding,
                                "endpoint",
                                state->ncalrpc_endpoint);
                        if (!NT_STATUS_IS_OK(status)) {
                                DBG_DEBUG("dcerpc_binding_set_string_option "
                                          "failed: %s\n",
                                          nt_errstr(status));
                                goto fail;
                        }
                }
        }

        for (i=0; i<num_endpoints; i++) {

                bool ok = dcerpc_binding_same_endpoint(
                        ep->binding, state->endpoints[i]->binding);

                if (ok) {
                        TALLOC_FREE(ep);
                        return state->endpoints[i];
                }
        }

        if (num_endpoints + 1 < num_endpoints) {
                goto fail;
        }

        tmp = talloc_realloc(
                state,
                state->endpoints,
                struct rpc_host_endpoint *,
                num_endpoints + 1);
        if (tmp == NULL) {
                goto fail;
        }
        state->endpoints = tmp;
        state->endpoints[num_endpoints] = talloc_move(state->endpoints, &ep);

        return state->endpoints[num_endpoints];
fail:
        TALLOC_FREE(ep);
        return NULL;
}

static bool ndr_interfaces_add_unique(
        TALLOC_CTX *mem_ctx,
        struct ndr_syntax_id **pifaces,
        const struct ndr_syntax_id *iface)
{
        struct ndr_syntax_id *ifaces = *pifaces;
        size_t i, num_ifaces = talloc_array_length(ifaces);

        for (i=0; i<num_ifaces; i++) {
                if (ndr_syntax_id_equal(iface, &ifaces[i])) {
                        return true;
                }
        }

        if (num_ifaces + 1 < num_ifaces) {
                return false;
        }
        ifaces = talloc_realloc(
                mem_ctx,
                ifaces,
                struct ndr_syntax_id,
                num_ifaces + 1);
        if (ifaces == NULL) {
                return false;
        }
        ifaces[num_ifaces] = *iface;

        *pifaces = ifaces;
        return true;
}

/*
 * Read the text reply from the rpcd_* process telling us what
 * endpoints it will serve when asked with --list-interfaces.
 */
static void rpc_server_get_endpoints_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct rpc_server_get_endpoints_state *state = tevent_req_data(
                req, struct rpc_server_get_endpoints_state);
        struct rpc_host_iface_name *iface = NULL;
        uint8_t *buf = NULL;
        size_t buflen;
        char **lines = NULL;
        int ret, i, num_lines;

        ret = file_ploadv_recv(subreq, state, &buf);
        TALLOC_FREE(subreq);
        if (tevent_req_error(req, ret)) {
                return;
        }

        buflen = talloc_get_size(buf);
        if (buflen == 0) {
                tevent_req_done(req);
                return;
        }

        lines = file_lines_parse((char *)buf, buflen, &num_lines, state);
        if (tevent_req_nomem(lines, req)) {
                return;
        }

        if (num_lines < 2) {
                DBG_DEBUG("Got %d lines, expected at least 2\n", num_lines);
                tevent_req_error(req, EINVAL);
                return;
        }

        state->num_workers = smb_strtoul(
                lines[0], NULL, 10, &ret, SMB_STR_FULL_STR_CONV);
        if (ret != 0) {
                DBG_DEBUG("Could not parse num_workers(%s): %s\n",
                          lines[0],
                          strerror(ret));
                tevent_req_error(req, ret);
                return;
        }

        state->idle_seconds = smb_strtoul(
                lines[1], NULL, 10, &ret, SMB_STR_FULL_STR_CONV);
        if (ret != 0) {
                DBG_DEBUG("Could not parse idle_seconds (%s): %s\n",
                          lines[1],
                          strerror(ret));
                tevent_req_error(req, ret);
                return;
        }

        DBG_DEBUG("num_workers=%lu, idle_seconds=%lu for %s\n",
                  state->num_workers,
                  state->idle_seconds,
                  state->argl[0]);

        for (i=2; i<num_lines; i++) {
                char *line = lines[i];
                struct rpc_host_endpoint *endpoint = NULL;
                bool ok;

                if (line[0] != ' ') {
                        iface = rpc_exe_parse_iface_line(
                                state, &state->iface_names, line);
                        if (iface == NULL) {
                                DBG_WARNING(
                                        "rpc_exe_parse_iface_line failed "
                                        "for: [%s] from %s\n",
                                        line,
                                        state->argl[0]);
                                tevent_req_oom(req);
                                return;
                        }
                        continue;
                }

                if (iface == NULL) {
                        DBG_DEBUG("Interface GUID line missing\n");
                        tevent_req_error(req, EINVAL);
                        return;
                }

                endpoint = rpc_host_endpoint_find(state, line+1);
                if (endpoint == NULL) {
                        DBG_DEBUG("rpc_host_endpoint_find for %s failed\n",
                                  line+1);
                        continue;
                }

                ok = ndr_interfaces_add_unique(
                        endpoint,
                        &endpoint->interfaces,
                        &iface->iface);
                if (!ok) {
                        DBG_DEBUG("ndr_interfaces_add_unique failed\n");
                        tevent_req_oom(req);
                        return;
                }
        }

        tevent_req_done(req);
}

/**
 * @brief Receive output from --list-interfaces
 *
 * @param[in] req The async req that just finished
 * @param[in] mem_ctx Where to put the output on
 * @param[out] endpoints The endpoints to be listened on
 * @param[out] iface_names Annotation for epm_Lookup's epm_entry_t
 * @return 0/errno
 */
static int rpc_server_get_endpoints_recv(
        struct tevent_req *req,
        TALLOC_CTX *mem_ctx,
        struct rpc_host_endpoint ***endpoints,
        struct rpc_host_iface_name **iface_names,
        size_t *num_workers,
        size_t *idle_seconds)
{
        struct rpc_server_get_endpoints_state *state = tevent_req_data(
                req, struct rpc_server_get_endpoints_state);
        int err;

        if (tevent_req_is_unix_error(req, &err)) {
                tevent_req_received(req);
                return err;
        }

        *endpoints = talloc_move(mem_ctx, &state->endpoints);
        *iface_names = talloc_move(mem_ctx, &state->iface_names);
        *num_workers = state->num_workers;
        *idle_seconds = state->idle_seconds;
        tevent_req_received(req);
        return 0;
}

/*
 * For NCACN_NP we get the named pipe auth info from smbd, if a client
 * comes in via TCP or NCALPRC we need to invent it ourselves with
 * anonymous session info.
 */

static NTSTATUS rpc_host_generate_npa_info7_from_sock(
        TALLOC_CTX *mem_ctx,
        enum dcerpc_transport_t transport,
        int sock,
        const struct samba_sockaddr *peer_addr,
        struct named_pipe_auth_req_info7 **pinfo7)
{
        struct named_pipe_auth_req_info7 *info7 = NULL;
        struct samba_sockaddr local_addr = {
                .sa_socklen = sizeof(struct sockaddr_storage),
        };
        struct tsocket_address *taddr = NULL;
        char *remote_client_name = NULL;
        char *remote_client_addr = NULL;
        char *local_server_name = NULL;
        char *local_server_addr = NULL;
        char *(*tsocket_address_to_name_fn)(
                const struct tsocket_address *addr,
                TALLOC_CTX *mem_ctx) = NULL;
        NTSTATUS status = NT_STATUS_NO_MEMORY;
        int ret;

        /*
         * For NCACN_NP we get the npa info from smbd
         */
        SMB_ASSERT((transport == NCACN_IP_TCP) || (transport == NCALRPC));

        tsocket_address_to_name_fn = (transport == NCACN_IP_TCP) ?
                tsocket_address_inet_addr_string : tsocket_address_unix_path;

        info7 = talloc_zero(mem_ctx, struct named_pipe_auth_req_info7);
        if (info7 == NULL) {
                goto fail;
        }
        info7->session_info =
                talloc_zero(info7, struct auth_session_info_transport);
        if (info7->session_info == NULL) {
                goto fail;
        }

        status = make_session_info_anonymous(
                info7->session_info,
                &info7->session_info->session_info);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("make_session_info_anonymous failed: %s\n",
                          nt_errstr(status));
                goto fail;
        }

        ret = tsocket_address_bsd_from_samba_sockaddr(info7,
                                                      peer_addr,
                                                      &taddr);
        if (ret == -1) {
                status = map_nt_error_from_unix(errno);
                DBG_DEBUG("tsocket_address_bsd_from_samba_sockaddr failed: "
                          "%s\n",
                          strerror(errno));
                goto fail;
        }
        remote_client_addr = tsocket_address_to_name_fn(taddr, info7);
        if (remote_client_addr == NULL) {
                DBG_DEBUG("tsocket_address_to_name_fn failed\n");
                goto nomem;
        }
        TALLOC_FREE(taddr);

        remote_client_name = talloc_strdup(info7, remote_client_addr);
        if (remote_client_name == NULL) {
                DBG_DEBUG("talloc_strdup failed\n");
                goto nomem;
        }

        if (transport == NCACN_IP_TCP) {
                bool ok = samba_sockaddr_get_port(peer_addr,
                                                  &info7->remote_client_port);
                if (!ok) {
                        DBG_DEBUG("samba_sockaddr_get_port failed\n");
                        status = NT_STATUS_INVALID_PARAMETER;
                        goto fail;
                }
        }

        ret = getsockname(sock, &local_addr.u.sa, &local_addr.sa_socklen);
        if (ret == -1) {
                status = map_nt_error_from_unix(errno);
                DBG_DEBUG("getsockname failed: %s\n", strerror(errno));
                goto fail;
        }

        ret = tsocket_address_bsd_from_samba_sockaddr(info7,
                                                      &local_addr,
                                                      &taddr);
        if (ret == -1) {
                status = map_nt_error_from_unix(errno);
                DBG_DEBUG("tsocket_address_bsd_from_samba_sockaddr failed: "
                          "%s\n",
                          strerror(errno));
                goto fail;
        }
        local_server_addr = tsocket_address_to_name_fn(taddr, info7);
        if (local_server_addr == NULL) {
                DBG_DEBUG("tsocket_address_to_name_fn failed\n");
                goto nomem;
        }
        TALLOC_FREE(taddr);

        local_server_name = talloc_strdup(info7, local_server_addr);
        if (local_server_name == NULL) {
                DBG_DEBUG("talloc_strdup failed\n");
                goto nomem;
        }

        if (transport == NCACN_IP_TCP) {
                bool ok = samba_sockaddr_get_port(&local_addr,
                                                  &info7->local_server_port);
                if (!ok) {
                        DBG_DEBUG("samba_sockaddr_get_port failed\n");
                        status = NT_STATUS_INVALID_PARAMETER;
                        goto fail;
                }
        }

        if (transport == NCALRPC) {
                uid_t uid;
                gid_t gid;

                ret = getpeereid(sock, &uid, &gid);
                if (ret < 0) {
                        status = map_nt_error_from_unix(errno);
                        DBG_DEBUG("getpeereid failed: %s\n", strerror(errno));
                        goto fail;
                }

                if (uid == sec_initial_uid()) {

                        /*
                         * Indicate "root" to gensec
                         */

                        TALLOC_FREE(remote_client_addr);
                        TALLOC_FREE(remote_client_name);

                        ret = tsocket_address_unix_from_path(
                                info7,
                                AS_SYSTEM_MAGIC_PATH_TOKEN,
                                &taddr);
                        if (ret == -1) {
                                DBG_DEBUG("tsocket_address_unix_from_path "
                                          "failed\n");
                                goto nomem;
                        }

                        remote_client_addr =
                                tsocket_address_unix_path(taddr, info7);
                        if (remote_client_addr == NULL) {
                                DBG_DEBUG("tsocket_address_unix_path "
                                          "failed\n");
                                goto nomem;
                        }
                        remote_client_name =
                                talloc_strdup(info7, remote_client_addr);
                        if (remote_client_name == NULL) {
                                DBG_DEBUG("talloc_strdup failed\n");
                                goto nomem;
                        }
                }
        }

        info7->remote_client_addr = remote_client_addr;
        info7->remote_client_name = remote_client_name;
        info7->local_server_addr = local_server_addr;
        info7->local_server_name = local_server_name;

        *pinfo7 = info7;
        return NT_STATUS_OK;

nomem:
        status = NT_STATUS_NO_MEMORY;
fail:
        TALLOC_FREE(info7);
        return status;
}

struct rpc_host_bind_read_state {
        struct tevent_context *ev;

        int sock;
        struct tstream_context *plain;
        struct tstream_context *npa_stream;

        struct ncacn_packet *pkt;
        struct rpc_host_client *client;
};

static void rpc_host_bind_read_cleanup(
        struct tevent_req *req, enum tevent_req_state req_state);
static void rpc_host_bind_read_got_npa(struct tevent_req *subreq);
static void rpc_host_bind_read_got_bind(struct tevent_req *subreq);

/*
 * Wait for a bind packet from a client.
 */
static struct tevent_req *rpc_host_bind_read_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        enum dcerpc_transport_t transport,
        int *psock,
        const struct samba_sockaddr *peer_addr)
{
        struct tevent_req *req = NULL, *subreq = NULL;
        struct rpc_host_bind_read_state *state = NULL;
        int rc, sock_dup;
        NTSTATUS status;

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

        state->sock = *psock;
        *psock = -1;

        tevent_req_set_cleanup_fn(req, rpc_host_bind_read_cleanup);

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

        /*
         * Dup the socket to read the first RPC packet:
         * tstream_bsd_existing_socket() takes ownership with
         * autoclose, but we need to send "sock" down to our worker
         * process later.
         */
        sock_dup = dup(state->sock);
        if (sock_dup == -1) {
                tevent_req_error(req, errno);
                return tevent_req_post(req, ev);
        }

        rc = tstream_bsd_existing_socket(state, sock_dup, &state->plain);
        if (rc == -1) {
                DBG_DEBUG("tstream_bsd_existing_socket failed: %s\n",
                          strerror(errno));
                tevent_req_error(req, errno);
                close(sock_dup);
                return tevent_req_post(req, ev);
        }

        if (transport == NCACN_NP) {
                subreq = tstream_npa_accept_existing_send(
                        state,
                        ev,
                        state->plain,
                        FILE_TYPE_MESSAGE_MODE_PIPE,
                        0xff | 0x0400 | 0x0100,
                        4096);
                if (tevent_req_nomem(subreq, req)) {
                        return tevent_req_post(req, ev);
                }
                tevent_req_set_callback(
                        subreq, rpc_host_bind_read_got_npa, req);
                return req;
        }

        status = rpc_host_generate_npa_info7_from_sock(
                state->client,
                transport,
                state->sock,
                peer_addr,
                &state->client->npa_info7);
        if (!NT_STATUS_IS_OK(status)) {
                tevent_req_oom(req);
                return tevent_req_post(req, ev);
        }

        subreq = dcerpc_read_ncacn_packet_send(state, ev, state->plain);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, rpc_host_bind_read_got_bind, req);
        return req;
}

static void rpc_host_bind_read_cleanup(
        struct tevent_req *req, enum tevent_req_state req_state)
{
        struct rpc_host_bind_read_state *state = tevent_req_data(
                req, struct rpc_host_bind_read_state);

        if ((req_state == TEVENT_REQ_RECEIVED) && (state->sock != -1)) {
                close(state->sock);
                state->sock = -1;
        }
}

static void rpc_host_bind_read_got_npa(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct rpc_host_bind_read_state *state = tevent_req_data(
                req, struct rpc_host_bind_read_state);
        struct named_pipe_auth_req_info7 *info7 = NULL;
        int ret, err;

        ret = tstream_npa_accept_existing_recv(subreq,
                                               &err,
                                               state,
                                               &state->npa_stream,
                                               &info7,
                                               NULL,  /* transport */
                                               NULL,  /* remote_client_addr */
                                               NULL,  /* remote_client_name */
                                               NULL,  /* local_server_addr */
                                               NULL,  /* local_server_name */
                                               NULL); /* session_info */
        if (ret == -1) {
                tevent_req_error(req, err);
                return;
        }

        state->client->npa_info7 = talloc_move(state->client, &info7);

        subreq = dcerpc_read_ncacn_packet_send(
                state, state->ev, state->npa_stream);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
        tevent_req_set_callback(subreq, rpc_host_bind_read_got_bind, req);
}

static void rpc_host_bind_read_got_bind(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct rpc_host_bind_read_state *state = tevent_req_data(
                req, struct rpc_host_bind_read_state);
        struct ncacn_packet *pkt = NULL;
        NTSTATUS status;

        status = dcerpc_read_ncacn_packet_recv(
                subreq,
                state->client,
                &pkt,
                &state->client->bind_packet);
        TALLOC_FREE(subreq);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("dcerpc_read_ncacn_packet_recv failed: %s\n",
                          nt_errstr(status));
                tevent_req_error(req, EINVAL); /* TODO */
                return;
        }
        state->pkt = talloc_move(state, &pkt);

        tevent_req_done(req);
}

static int rpc_host_bind_read_recv(
        struct tevent_req *req,
        TALLOC_CTX *mem_ctx,
        int *sock,
        struct rpc_host_client **client,
        struct ncacn_packet **bind_pkt)
{
        struct rpc_host_bind_read_state *state = tevent_req_data(
                req, struct rpc_host_bind_read_state);
        int err;

        if (tevent_req_is_unix_error(req, &err)) {
                tevent_req_received(req);
                return err;
        }

        *sock = state->sock;
        state->sock = -1;

        *client = talloc_move(mem_ctx, &state->client);
        *bind_pkt = talloc_move(mem_ctx, &state->pkt);
        tevent_req_received(req);
        return 0;
}

/*
 * Start the given rpcd_* binary.
 */
static int rpc_host_exec_worker(struct rpc_server *server, size_t idx)
{
        struct rpc_work_process *worker = &server->workers[idx];
        char **argv = NULL;
        int ret = ENOMEM;

        argv = str_list_make_empty(server);
        str_list_add_printf(
                &argv, "%s", server->rpc_server_exe);
        str_list_add_printf(
                &argv, "--configfile=%s", get_dyn_CONFIGFILE());
        str_list_add_printf(
                &argv, "--worker-group=%"PRIu32, server->server_index);
        str_list_add_printf(
                &argv, "--worker-index=%zu", idx);
        str_list_add_printf(
                &argv, "--debuglevel=%d", debuglevel_get_class(DBGC_RPC_SRV));
        if (!is_default_dyn_LOGFILEBASE()) {
                str_list_add_printf(
                        &argv, "--log-basename=%s", get_dyn_LOGFILEBASE());
        }
        if (argv == NULL) {
                ret = ENOMEM;
                goto fail;
        }

        worker->pid = fork();
        if (worker->pid == -1) {
                ret = errno;
                goto fail;
        }
        if (worker->pid == 0) {
                /* Child. */
                close(server->host->worker_stdin[1]);
                ret = dup2(server->host->worker_stdin[0], 0);
                if (ret != 0) {
                        exit(1);
                }
                execv(argv[0], argv);
                _exit(1);
        }

        DBG_DEBUG("Creating worker %s for index %zu: pid=%d\n",
                  server->rpc_server_exe,
                  idx,
                  (int)worker->pid);

        ret = 0;
fail:
        TALLOC_FREE(argv);
        return ret;
}

/*
 * Find an rpcd_* worker for an external client, respect server->max_workers
 */
static struct rpc_work_process *rpc_host_find_worker(struct rpc_server *server)
{
        struct rpc_work_process *worker = NULL;
        size_t i;
        size_t empty_slot = SIZE_MAX;

        uint32_t min_clients = UINT32_MAX;
        size_t min_worker = server->max_workers;

        for (i=0; i<server->max_workers; i++) {
                worker = &server->workers[i];

                if (worker->pid == -1) {
                        empty_slot = MIN(empty_slot, i);
                        continue;
                }
                if (!worker->available) {
                        continue;
                }
                if (worker->num_clients < min_clients) {
                        min_clients = worker->num_clients;
                        min_worker = i;
                }
        }

        if (min_clients == 0) {
                return &server->workers[min_worker];
        }

        if (empty_slot < SIZE_MAX) {
                int ret = rpc_host_exec_worker(server, empty_slot);
                if (ret != 0) {
                        DBG_WARNING("Could not fork worker: %s\n",
                                    strerror(ret));
                }
                return NULL;
        }

        if (min_worker < server->max_workers) {
                return &server->workers[min_worker];
        }

        return NULL;
}

/*
 * Find an rpcd_* worker for an internal connection, possibly go beyond
 * server->max_workers
 */
static struct rpc_work_process *rpc_host_find_idle_worker(
        struct rpc_server *server)
{
        struct rpc_work_process *worker = NULL, *tmp = NULL;
        size_t i, num_workers = talloc_array_length(server->workers);
        size_t empty_slot = SIZE_MAX;
        int ret;

        for (i=server->max_workers; i<num_workers; i++) {
                worker = &server->workers[i];

                if (worker->pid == -1) {
                        empty_slot = MIN(empty_slot, i);
                        continue;
                }
                if (!worker->available) {
                        continue;
                }
                if (worker->num_clients == 0) {
                        return &server->workers[i];
                }
        }

        if (empty_slot < SIZE_MAX) {
                ret = rpc_host_exec_worker(server, empty_slot);
                if (ret != 0) {
                        DBG_WARNING("Could not fork worker: %s\n",
                                    strerror(ret));
                }
                return NULL;
        }

        /*
         * All workers are busy. We need to expand the number of
         * workers because we were asked for an idle worker.
         */
        if (num_workers+1 < num_workers) {
                return NULL;
        }
        tmp = talloc_realloc(
                server,
                server->workers,
                struct rpc_work_process,
                num_workers+1);
        if (tmp == NULL) {
                return NULL;
        }
        server->workers = tmp;

        server->workers[num_workers] = (struct rpc_work_process) { .pid=-1, };

        ret = rpc_host_exec_worker(server, num_workers);
        if (ret != 0) {
                DBG_WARNING("Could not exec worker: %s\n", strerror(ret));
        }

        return NULL;
}

/*
 * Find an rpcd_* process to talk to. Start a new one if necessary.
 */
static void rpc_host_distribute_clients(struct rpc_server *server)
{
        struct rpc_work_process *worker = NULL;
        struct rpc_host_pending_client *pending_client = NULL;
        uint32_t assoc_group_id;
        DATA_BLOB blob;
        struct iovec iov;
        enum ndr_err_code ndr_err;
        NTSTATUS status;

again:
        pending_client = server->pending_clients;
        if (pending_client == NULL) {
                DBG_DEBUG("No pending clients\n");
                return;
        }

        assoc_group_id = pending_client->bind_pkt->u.bind.assoc_group_id;

        if (assoc_group_id != 0) {
                size_t num_workers = talloc_array_length(server->workers);
                uint8_t worker_index = assoc_group_id >> 24;

                if (worker_index >= num_workers) {
                        DBG_DEBUG("Invalid assoc group id %"PRIu32"\n",
                                  assoc_group_id);
                        goto done;
                }
                worker = &server->workers[worker_index];

                if ((worker->pid == -1) || !worker->available) {
                        DBG_DEBUG("Requested worker index %"PRIu8": "
                                  "pid=%d, available=%d",
                                  worker_index,
                                  (int)worker->pid,
                                  (int)worker->available);
                        /*
                         * Pick a random one for a proper bind nack
                         */
                        worker = rpc_host_find_worker(server);
                }
        } else {
                struct auth_session_info_transport *session_info =
                        pending_client->client->npa_info7->session_info;
                uint32_t flags = 0;
                bool found;

                found = security_token_find_npa_flags(
                        session_info->session_info->security_token,
                        &flags);

                /* fresh assoc group requested */
                if (found & (flags & SAMBA_NPA_FLAGS_NEED_IDLE)) {
                        worker = rpc_host_find_idle_worker(server);
                } else {
                        worker = rpc_host_find_worker(server);
                }
        }

        if (worker == NULL) {
                DBG_DEBUG("No worker found\n");
                return;
        }

        DLIST_REMOVE(server->pending_clients, pending_client);

        ndr_err = ndr_push_struct_blob(
                &blob,
                pending_client,
                pending_client->client,
                (ndr_push_flags_fn_t)ndr_push_rpc_host_client);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DBG_WARNING("ndr_push_rpc_host_client failed: %s\n",
                            ndr_errstr(ndr_err));
                goto done;
        }

        DBG_INFO("Sending new client %s to %d with %"PRIu32" clients\n",
                 server->rpc_server_exe,
                 worker->pid,
                 worker->num_clients);

        iov = (struct iovec) {
                .iov_base = blob.data, .iov_len = blob.length,
        };

        status = messaging_send_iov(
                server->host->msg_ctx,
                pid_to_procid(worker->pid),
                MSG_RPC_HOST_NEW_CLIENT,
                &iov,
                1,
                &pending_client->sock,
                1);
        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
                DBG_DEBUG("worker %d died, sigchld not yet received?\n",
                          worker->pid);
                DLIST_ADD(server->pending_clients, pending_client);
                worker->available = false;
                goto again;
        }
        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("messaging_send_iov failed: %s\n",
                          nt_errstr(status));
                goto done;
        }
        worker->num_clients += 1;
        TALLOC_FREE(worker->exit_timer);

        TALLOC_FREE(server->host->np_helper_shutdown);

done:
        TALLOC_FREE(pending_client);
}

static int rpc_host_pending_client_destructor(
        struct rpc_host_pending_client *p)
{
        TALLOC_FREE(p->hangup_wait);
        if (p->sock != -1) {
                close(p->sock);
                p->sock = -1;
        }
        DLIST_REMOVE(p->server->pending_clients, p);
        return 0;
}

/*
 * Exception condition handler before rpcd_* worker
 * is handling the socket. Either the client exited or
 * sent unexpected data after the initial bind.
 */
static void rpc_host_client_exited(struct tevent_req *subreq)
{
        struct rpc_host_pending_client *pending = tevent_req_callback_data(
                subreq, struct rpc_host_pending_client);
        bool ok;
        int err;

        ok = wait_for_read_recv(subreq, &err);

        TALLOC_FREE(subreq);
        pending->hangup_wait = NULL;

        if (ok) {
                DBG_DEBUG("client on sock %d sent data\n", pending->sock);
        } else {
                DBG_DEBUG("client exited with %s\n", strerror(err));
        }
        TALLOC_FREE(pending);
}

struct rpc_iface_binding_map {
        struct ndr_syntax_id iface;
        char *bindings;
};

static bool rpc_iface_binding_map_add_endpoint(
        TALLOC_CTX *mem_ctx,
        const struct rpc_host_endpoint *ep,
        struct rpc_host_iface_name *iface_names,
        struct rpc_iface_binding_map **pmaps)
{
        const struct ndr_syntax_id mgmt_iface = {
                {0xafa8bd80,
                 0x7d8a,
                 0x11c9,
                 {0xbe,0xf4},
                 {0x08,0x00,0x2b,0x10,0x29,0x89}
                },
                1.0};

        struct rpc_iface_binding_map *maps = *pmaps;
        size_t i, num_ifaces = talloc_array_length(ep->interfaces);
        char *binding_string = NULL;
        bool ok = false;

        binding_string = dcerpc_binding_string(mem_ctx, ep->binding);
        if (binding_string == NULL) {
                return false;
        }

        for (i=0; i<num_ifaces; i++) {
                const struct ndr_syntax_id *iface = &ep->interfaces[i];
                size_t j, num_maps = talloc_array_length(maps);
                struct rpc_iface_binding_map *map = NULL;
                char *p = NULL;

                if (ndr_syntax_id_equal(iface, &mgmt_iface)) {
                        /*
                         * mgmt is offered everywhere, don't put it
                         * into epmdb.tdb.
                         */
                        continue;
                }

                for (j=0; j<num_maps; j++) {
                        map = &maps[j];
                        if (ndr_syntax_id_equal(&map->iface, iface)) {
                                break;
                        }
                }

                if (j == num_maps) {
                        struct rpc_iface_binding_map *tmp = NULL;
                        struct rpc_host_iface_name *iface_name = NULL;

                        iface_name = rpc_host_iface_names_find(
                                iface_names, iface);
                        if (iface_name == NULL) {
                                goto fail;
                        }

                        tmp = talloc_realloc(
                                mem_ctx,
                                maps,
                                struct rpc_iface_binding_map,
                                num_maps+1);
                        if (tmp == NULL) {
                                goto fail;
                        }
                        maps = tmp;

                        map = &maps[num_maps];
                        *map = (struct rpc_iface_binding_map) {
                                .iface = *iface,
                                .bindings = talloc_move(
                                        maps, &iface_name->name),
                        };
                }

                p = strv_find(map->bindings, binding_string);
                if (p == NULL) {
                        int ret = strv_add(
                                maps, &map->bindings, binding_string);
                        if (ret != 0) {
                                goto fail;
                        }
                }
        }

        ok = true;
fail:
        *pmaps = maps;
        return ok;
}

static bool rpc_iface_binding_map_add_endpoints(
        TALLOC_CTX *mem_ctx,
        struct rpc_host_endpoint **endpoints,
        struct rpc_host_iface_name *iface_names,
        struct rpc_iface_binding_map **pbinding_maps)
{
        size_t i, num_endpoints = talloc_array_length(endpoints);

        for (i=0; i<num_endpoints; i++) {
                bool ok = rpc_iface_binding_map_add_endpoint(
                        mem_ctx, endpoints[i], iface_names, pbinding_maps);
                if (!ok) {
                        return false;
                }
        }
        return true;
}

static bool rpc_host_fill_epm_db(
        struct tdb_wrap *db,
        struct rpc_host_endpoint **endpoints,
        struct rpc_host_iface_name *iface_names)
{
        struct rpc_iface_binding_map *maps = NULL;
        size_t i, num_maps;
        bool ret = false;
        bool ok;

        ok = rpc_iface_binding_map_add_endpoints(
                talloc_tos(), endpoints, iface_names, &maps);
        if (!ok) {
                goto fail;
        }

        num_maps = talloc_array_length(maps);

        for (i=0; i<num_maps; i++) {
                struct rpc_iface_binding_map *map = &maps[i];
                struct ndr_syntax_id_buf buf;
                char *keystr = ndr_syntax_id_buf_string(&map->iface, &buf);
                TDB_DATA value = {
                        .dptr = (uint8_t *)map->bindings,
                        .dsize = talloc_array_length(map->bindings),
                };
                int rc;

                rc = tdb_store(
                        db->tdb, string_term_tdb_data(keystr), value, 0);
                if (rc == -1) {
                        DBG_DEBUG("tdb_store() failed: %s\n",
                                  tdb_errorstr(db->tdb));
                        goto fail;
                }
        }

        ret = true;
fail:
        TALLOC_FREE(maps);
        return ret;
}

struct rpc_server_setup_state {
        struct rpc_server *server;
};

static void rpc_server_setup_got_endpoints(struct tevent_req *subreq);

/*
 * Async initialize state for all possible rpcd_* servers.
 * Note this does not start them.
 */
static struct tevent_req *rpc_server_setup_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct rpc_host *host,
        const char *rpc_server_exe)
{
        struct tevent_req *req = NULL, *subreq = NULL;
        struct rpc_server_setup_state *state = NULL;
        struct rpc_server *server = NULL;

        req = tevent_req_create(
                mem_ctx, &state, struct rpc_server_setup_state);
        if (req == NULL) {
                return NULL;
        }
        state->server = talloc_zero(state, struct rpc_server);
        if (tevent_req_nomem(state->server, req)) {
                return tevent_req_post(req, ev);
        }

        server = state->server;

        *server = (struct rpc_server) {
                .host = host,
                .server_index = UINT32_MAX,
                .rpc_server_exe = talloc_strdup(server, rpc_server_exe),
        };
        if (tevent_req_nomem(server->rpc_server_exe, req)) {
                return tevent_req_post(req, ev);
        }

        subreq = rpc_server_get_endpoints_send(
                state,
                ev,
                rpc_server_exe,
                host->np_helper ? NCACN_NP : NCA_UNKNOWN);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
        tevent_req_set_callback(subreq, rpc_server_setup_got_endpoints, req);
        return req;
}

static void rpc_server_setup_got_endpoints(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct rpc_server_setup_state *state = tevent_req_data(
                req, struct rpc_server_setup_state);
        struct rpc_server *server = state->server;
        int ret;
        size_t i, num_endpoints;
        bool ok;

        ret = rpc_server_get_endpoints_recv(
                subreq,
                server,
                &server->endpoints,
                &server->iface_names,
                &server->max_workers,
                &server->idle_seconds);
        TALLOC_FREE(subreq);
        if (ret != 0) {
                tevent_req_nterror(req, map_nt_error_from_unix(ret));
                return;
        }

        server->workers = talloc_array(
                server, struct rpc_work_process, server->max_workers);
        if (tevent_req_nomem(server->workers, req)) {
                return;
        }

        for (i=0; i<server->max_workers; i++) {
                /* mark as not yet created */
                server->workers[i] = (struct rpc_work_process) { .pid=-1, };
        }

        num_endpoints = talloc_array_length(server->endpoints);

        for (i=0; i<num_endpoints; i++) {
                struct rpc_host_endpoint *e = server->endpoints[i];
                NTSTATUS status;
                size_t j;

                e->server = server;

                status = dcesrv_create_binding_sockets(
                        e->binding, e, &e->num_fds, &e->fds);
                if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_SUPPORTED)) {
                        continue;
                }
                if (tevent_req_nterror(req, status)) {
                        DBG_DEBUG("dcesrv_create_binding_sockets failed: %s\n",
                                  nt_errstr(status));
                        return;
                }

                for (j=0; j<e->num_fds; j++) {
                        ret = listen(e->fds[j], 256);
                        if (ret == -1) {
                                tevent_req_nterror(
                                        req, map_nt_error_from_unix(errno));
                                return;
                        }
                }
        }

        ok = rpc_host_fill_epm_db(
                server->host->epmdb, server->endpoints, server->iface_names);
        if (!ok) {
                DBG_DEBUG("rpc_host_fill_epm_db failed\n");
        }

        tevent_req_done(req);
}

static NTSTATUS rpc_server_setup_recv(
        struct tevent_req *req, TALLOC_CTX *mem_ctx, struct rpc_server **server)
{
        struct rpc_server_setup_state *state = tevent_req_data(
                req, struct rpc_server_setup_state);
        NTSTATUS status;

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

        *server = talloc_move(mem_ctx, &state->server);
        tevent_req_received(req);
        return NT_STATUS_OK;
}

/*
 * rpcd_* died. Called from SIGCHLD handler.
 */
static void rpc_worker_exited(struct rpc_host *host, pid_t pid)
{
        size_t i, num_servers = talloc_array_length(host->servers);
        struct rpc_work_process *worker = NULL;
        bool found_pid = false;
        bool have_active_worker = false;

        for (i=0; i<num_servers; i++) {
                struct rpc_server *server = host->servers[i];
                size_t j, num_workers;

                if (server == NULL) {
                        /* SIGCHLD for --list-interfaces run */
                        continue;
                }

                num_workers = talloc_array_length(server->workers);

                for (j=0; j<num_workers; j++) {
                        worker = &server->workers[j];
                        if (worker->pid == pid) {
                                found_pid = true;
                                worker->pid = -1;
                                worker->available = false;
                        }

                        if (worker->pid != -1) {
                                have_active_worker = true;
                        }
                }
        }

        if (!found_pid) {
                DBG_WARNING("No worker with PID %d\n", (int)pid);
                return;
        }

        if (!have_active_worker && host->np_helper) {
                /*
                 * We have nothing left to do as an np_helper.
                 * Terminate ourselves (samba-dcerpcd). We will
                 * be restarted on demand anyway.
                 */
                DBG_DEBUG("Exiting idle np helper\n");
                exit(0);
        }
}

/*
 * rpcd_* died.
 */
static void rpc_host_sigchld(
        struct tevent_context *ev,
        struct tevent_signal *se,
        int signum,
        int count,
        void *siginfo,
        void *private_data)
{
        struct rpc_host *state = talloc_get_type_abort(
                private_data, struct rpc_host);
        pid_t pid;
        int wstatus;

        while ((pid = waitpid(-1, &wstatus, WNOHANG)) > 0) {
                DBG_DEBUG("pid=%d, wstatus=%d\n", (int)pid, wstatus);
                rpc_worker_exited(state, pid);
        }
}

/*
 * Idle timer fired for a rcpd_* worker. Ask it to terminate.
 */
static void rpc_host_exit_worker(
        struct tevent_context *ev,
        struct tevent_timer *te,
        struct timeval current_time,
        void *private_data)
{
        struct rpc_server *server = talloc_get_type_abort(
                private_data, struct rpc_server);
        size_t i, num_workers = talloc_array_length(server->workers);

        /*
         * Scan for the right worker. We don't have too many of those,
         * and maintaining an index would be more data structure effort.
         */

        for (i=0; i<num_workers; i++) {
                struct rpc_work_process *w = &server->workers[i];
                NTSTATUS status;

                if (w->exit_timer != te) {
                        continue;
                }
                w->exit_timer = NULL;

                SMB_ASSERT(w->num_clients == 0);

                status = messaging_send(
                        server->host->msg_ctx,
                        pid_to_procid(w->pid),
                        MSG_SHUTDOWN,
                        NULL);
                if (!NT_STATUS_IS_OK(status)) {
                        DBG_DEBUG("Could not send SHUTDOWN msg: %s\n",
                                  nt_errstr(status));
                }

                w->available = false;
                break;
        }
}

/*
 * rcpd_* worker replied with its status.
 */
static void rpc_host_child_status_recv(
        struct messaging_context *msg,
        void *private_data,
        uint32_t msg_type,
        struct server_id server_id,
        DATA_BLOB *data)
{
        struct rpc_host *host = talloc_get_type_abort(
                private_data, struct rpc_host);
        size_t num_servers = talloc_array_length(host->servers);
        struct rpc_server *server = NULL;
        size_t num_workers;
        pid_t src_pid = procid_to_pid(&server_id);
        struct rpc_work_process *worker = NULL;
        struct rpc_worker_status status_message;
        enum ndr_err_code ndr_err;

        ndr_err = ndr_pull_struct_blob_all_noalloc(
                data,
                &status_message,
                (ndr_pull_flags_fn_t)ndr_pull_rpc_worker_status);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                struct server_id_buf buf;
                DBG_WARNING("Got invalid message from pid %s\n",
                            server_id_str_buf(server_id, &buf));
                return;
        }
        if (DEBUGLEVEL >= 10) {
                NDR_PRINT_DEBUG(rpc_worker_status, &status_message);
        }

        if (status_message.server_index >= num_servers) {
                DBG_WARNING("Got invalid server_index=%"PRIu32", "
                            "num_servers=%zu\n",
                            status_message.server_index,
                            num_servers);
                return;
        }

        server = host->servers[status_message.server_index];

        num_workers = talloc_array_length(server->workers);
        if (status_message.worker_index >= num_workers) {
                DBG_WARNING("Got invalid worker_index=%"PRIu32", "
                            "num_workers=%zu\n",
                            status_message.worker_index,
                            num_workers);
                return;
        }
        worker = &server->workers[status_message.worker_index];

        if (src_pid != worker->pid) {
                DBG_WARNING("Got idx=%"PRIu32" from %d, expected %d\n",
                            status_message.worker_index,
                            (int)src_pid,
                            worker->pid);
                return;
        }

        worker->available = true;
        worker->num_clients = status_message.num_clients;

        if (worker->num_clients != 0) {
                TALLOC_FREE(worker->exit_timer);
        } else {
                worker->exit_timer = tevent_add_timer(
                        messaging_tevent_context(msg),
                        server->workers,
                        tevent_timeval_current_ofs(server->idle_seconds, 0),
                        rpc_host_exit_worker,
                        server);
                /* No NULL check, it's not fatal if this does not work */
        }

        rpc_host_distribute_clients(server);
}

/*
 * samba-dcerpcd has been asked to shutdown.
 * Mark the initial tevent_req as done so we
 * exit the event loop.
 */
static void rpc_host_msg_shutdown(
        struct messaging_context *msg,
        void *private_data,
        uint32_t msg_type,
        struct server_id server_id,
        DATA_BLOB *data)
{
        struct tevent_req *req = talloc_get_type_abort(
                private_data, struct tevent_req);
        tevent_req_done(req);
}

/*
 * Only match directory entries starting in rpcd_
 */
static int rpcd_filter(const struct dirent *d)
{
        int match = fnmatch("rpcd_*", d->d_name, 0);
        return (match == 0) ? 1 : 0;
}

/*
 * Scan the given libexecdir for rpcd_* services
 * and return them as a strv list.
 */
static int rpc_host_list_servers(
        const char *libexecdir, TALLOC_CTX *mem_ctx, char **pservers)
{
        char *servers = NULL;
        struct dirent **namelist = NULL;
        int i, num_servers;
        int ret = ENOMEM;

        num_servers = scandir(libexecdir, &namelist, rpcd_filter, alphasort);
        if (num_servers == -1) {
                DBG_DEBUG("scandir failed: %s\n", strerror(errno));
                return errno;
        }

        for (i=0; i<num_servers; i++) {
                char *exe = talloc_asprintf(
                        mem_ctx, "%s/%s", libexecdir, namelist[i]->d_name);
                if (exe == NULL) {
                        goto fail;
                }

                ret = strv_add(mem_ctx, &servers, exe);
                TALLOC_FREE(exe);
                if (ret != 0) {
                        goto fail;
                }
        }
fail:
        for (i=0; i<num_servers; i++) {
                SAFE_FREE(namelist[i]);
        }
        SAFE_FREE(namelist);

        if (ret != 0) {
                TALLOC_FREE(servers);
                return ret;
        }
        *pservers = servers;
        return 0;
}

struct rpc_host_endpoint_accept_state {
        struct tevent_context *ev;
        struct rpc_host_endpoint *endpoint;
};

static void rpc_host_endpoint_accept_accepted(struct tevent_req *subreq);
static void rpc_host_endpoint_accept_got_bind(struct tevent_req *subreq);

/*
 * Asynchronously wait for a DCERPC connection from a client.
 */
static struct tevent_req *rpc_host_endpoint_accept_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct rpc_host_endpoint *endpoint)
{
        struct tevent_req *req = NULL;
        struct rpc_host_endpoint_accept_state *state = NULL;
        size_t i;

        req = tevent_req_create(
                mem_ctx, &state, struct rpc_host_endpoint_accept_state);
        if (req == NULL) {
                return NULL;
        }
        state->ev = ev;
        state->endpoint = endpoint;

        for (i=0; i<endpoint->num_fds; i++) {
                struct tevent_req *subreq = NULL;

                subreq = accept_send(state, ev, endpoint->fds[i]);
                if (tevent_req_nomem(subreq, req)) {
                        return tevent_req_post(req, ev);
                }
                tevent_req_set_callback(
                        subreq, rpc_host_endpoint_accept_accepted, req);
        }

        return req;
}

/*
 * Accept a DCERPC connection from a client.
 */
static void rpc_host_endpoint_accept_accepted(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct rpc_host_endpoint_accept_state *state = tevent_req_data(
                req, struct rpc_host_endpoint_accept_state);
        struct rpc_host_endpoint *endpoint = state->endpoint;
        int sock, listen_sock, err;
        struct samba_sockaddr peer_addr;

        sock = accept_recv(subreq, &listen_sock, &peer_addr, &err);
        TALLOC_FREE(subreq);
        if (sock == -1) {
                /* What to do here? Just ignore the error and retry? */
                DBG_DEBUG("accept_recv failed: %s\n", strerror(err));
                tevent_req_error(req, err);
                return;
        }

        subreq = accept_send(state, state->ev, listen_sock);
        if (tevent_req_nomem(subreq, req)) {
                close(sock);
                sock = -1;
                return;
        }
        tevent_req_set_callback(
                subreq, rpc_host_endpoint_accept_accepted, req);

        subreq = rpc_host_bind_read_send(
                state,
                state->ev,
                dcerpc_binding_get_transport(endpoint->binding),
                &sock,
                &peer_addr);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
        tevent_req_set_callback(
                subreq, rpc_host_endpoint_accept_got_bind, req);
}

/*
 * Client sent us a DCERPC bind packet.
 */
static void rpc_host_endpoint_accept_got_bind(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct rpc_host_endpoint_accept_state *state = tevent_req_data(
                req, struct rpc_host_endpoint_accept_state);
        struct rpc_host_endpoint *endpoint = state->endpoint;
        struct rpc_server *server = endpoint->server;
        struct rpc_host_pending_client *pending = NULL;
        struct rpc_host_client *client = NULL;
        struct ncacn_packet *bind_pkt = NULL;
        int ret;
        int sock=-1;

        ret = rpc_host_bind_read_recv(
                subreq, state, &sock, &client, &bind_pkt);
        TALLOC_FREE(subreq);
        if (ret != 0) {
                DBG_DEBUG("rpc_host_bind_read_recv returned %s\n",
                          strerror(ret));
                goto fail;
        }

        client->binding = dcerpc_binding_string(client, endpoint->binding);
        if (client->binding == NULL) {
                DBG_WARNING("dcerpc_binding_string failed, dropping client\n");
                goto fail;
        }

        pending = talloc_zero(server, struct rpc_host_pending_client);
        if (pending == NULL) {
                DBG_WARNING("talloc failed, dropping client\n");
                goto fail;
        }
        pending->server = server;
        pending->sock = sock;
        pending->bind_pkt = talloc_move(pending, &bind_pkt);
        pending->client = talloc_move(pending, &client);
        talloc_set_destructor(pending, rpc_host_pending_client_destructor);
        sock = -1;

        pending->hangup_wait = wait_for_read_send(
                pending, state->ev, pending->sock, true);
        if (pending->hangup_wait == NULL) {
                DBG_WARNING("wait_for_read_send failed, dropping client\n");
                TALLOC_FREE(pending);
                return;
        }
        tevent_req_set_callback(
                pending->hangup_wait, rpc_host_client_exited, pending);

        DLIST_ADD_END(server->pending_clients, pending);
        rpc_host_distribute_clients(server);
        return;

fail:
        TALLOC_FREE(client);
        if (sock != -1) {
                close(sock);
        }
}

static int rpc_host_endpoint_accept_recv(
        struct tevent_req *req, struct rpc_host_endpoint **ep)
{
        struct rpc_host_endpoint_accept_state *state = tevent_req_data(
                req, struct rpc_host_endpoint_accept_state);

        *ep = state->endpoint;

        return tevent_req_simple_recv_unix(req);
}

/*
 * Full state for samba-dcerpcd. Everything else
 * is hung off this.
 */
struct rpc_host_state {
        struct tevent_context *ev;
        struct rpc_host *host;

        bool is_ready;
        const char *daemon_ready_progname;
        struct tevent_immediate *ready_signal_immediate;
        int *ready_signal_fds;

        size_t num_servers;
        size_t num_prepared;
};

/*
 * Tell whoever invoked samba-dcerpcd we're ready to
 * serve.
 */
static void rpc_host_report_readiness(
        struct tevent_context *ev,
        struct tevent_immediate *im,
        void *private_data)
{
        struct rpc_host_state *state = talloc_get_type_abort(
                private_data, struct rpc_host_state);
        size_t i, num_fds = talloc_array_length(state->ready_signal_fds);

        if (!state->is_ready) {
                DBG_DEBUG("Not yet ready\n");
                return;
        }

        for (i=0; i<num_fds; i++) {
                uint8_t byte = 0;
                ssize_t nwritten;

                do {
                        nwritten = write(
                                state->ready_signal_fds[i],
                                (void *)&byte,
                                sizeof(byte));
                } while ((nwritten == -1) && (errno == EINTR));

                close(state->ready_signal_fds[i]);
        }

        TALLOC_FREE(state->ready_signal_fds);
}

/*
 * Respond to a "are you ready" message.
 */
static bool rpc_host_ready_signal_filter(
        struct messaging_rec *rec, void *private_data)
{
        struct rpc_host_state *state = talloc_get_type_abort(
                private_data, struct rpc_host_state);
        size_t num_fds = talloc_array_length(state->ready_signal_fds);
        int *tmp = NULL;

        if (rec->msg_type != MSG_DAEMON_READY_FD) {
                return false;
        }
        if (rec->num_fds != 1) {
                DBG_DEBUG("Got %"PRIu8" fds\n", rec->num_fds);
                return false;
        }

        if (num_fds + 1 < num_fds) {
                return false;
        }
        tmp = talloc_realloc(state, state->ready_signal_fds, int, num_fds+1);
        if (tmp == NULL) {
                return false;
        }
        state->ready_signal_fds = tmp;

        state->ready_signal_fds[num_fds] = rec->fds[0];
        rec->fds[0] = -1;

        tevent_schedule_immediate(
                state->ready_signal_immediate,
                state->ev,
                rpc_host_report_readiness,
                state);

        return false;
}

/*
 * Respond to a "what is your status" message.
 */
static bool rpc_host_dump_status_filter(
        struct messaging_rec *rec, void *private_data)
{
        struct rpc_host_state *state = talloc_get_type_abort(
                private_data, struct rpc_host_state);
        struct rpc_host *host = state->host;
        struct rpc_server **servers = host->servers;
        size_t i, num_servers = talloc_array_length(servers);
        FILE *f = NULL;
        int fd;

        if (rec->msg_type != MSG_RPC_DUMP_STATUS) {
                return false;
        }
        if (rec->num_fds != 1) {
                DBG_DEBUG("Got %"PRIu8" fds\n", rec->num_fds);
                return false;
        }

        fd = dup(rec->fds[0]);
        if (fd == -1) {
                DBG_DEBUG("dup(%"PRIi64") failed: %s\n",
                          rec->fds[0],
                          strerror(errno));
                return false;
        }

        f = fdopen(fd, "w");
        if (f == NULL) {
                DBG_DEBUG("fdopen failed: %s\n", strerror(errno));
                close(fd);
                return false;
        }

        for (i=0; i<num_servers; i++) {
                struct rpc_server *server = servers[i];
                size_t j, num_workers = talloc_array_length(server->workers);
                size_t active_workers = 0;

                for (j=0; j<num_workers; j++) {
                        if (server->workers[j].pid != -1) {
                                active_workers += 1;
                        }
                }

                fprintf(f,
                        "%s: active_workers=%zu\n",
                        server->rpc_server_exe,
                        active_workers);

                for (j=0; j<num_workers; j++) {
                        struct rpc_work_process *w = &server->workers[j];

                        if (w->pid == (pid_t)-1) {
                                continue;
                        }

                        fprintf(f,
                                " worker[%zu]: pid=%d, num_clients=%"PRIu32"\n",
                                j,
                                (int)w->pid,
                                w->num_clients);
                }
        }

        fclose(f);

        return false;
}

static void rpc_host_server_setup_done(struct tevent_req *subreq);
static void rpc_host_endpoint_failed(struct tevent_req *subreq);

/*
 * Async startup for samba-dcerpcd.
 */
static struct tevent_req *rpc_host_send(
        TALLOC_CTX *mem_ctx,
        struct tevent_context *ev,
        struct messaging_context *msg_ctx,
        char *servers,
        int ready_signal_fd,
        const char *daemon_ready_progname,
        bool is_np_helper)
{
        struct tevent_req *req = NULL, *subreq = NULL;
        struct rpc_host_state *state = NULL;
        struct rpc_host *host = NULL;
        struct tevent_signal *se = NULL;
        char *epmdb_path = NULL;
        char *exe = NULL;
        size_t i, num_servers = strv_count(servers);
        NTSTATUS status;
        int ret;

        req = tevent_req_create(req, &state, struct rpc_host_state);
        if (req == NULL) {
                return NULL;
        }
        state->ev = ev;
        state->daemon_ready_progname = daemon_ready_progname;

        state->ready_signal_immediate = tevent_create_immediate(state);
        if (tevent_req_nomem(state->ready_signal_immediate, req)) {
                return tevent_req_post(req, ev);
        }

        if (ready_signal_fd != -1) {
                state->ready_signal_fds = talloc_array(state, int, 1);
                if (tevent_req_nomem(state->ready_signal_fds, req)) {
                        return tevent_req_post(req, ev);
                }
                state->ready_signal_fds[0] = ready_signal_fd;
        }

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

        host->msg_ctx = msg_ctx;
        host->np_helper = is_np_helper;

        ret = pipe(host->worker_stdin);
        if (ret == -1) {
                tevent_req_nterror(req, map_nt_error_from_unix(errno));
                return tevent_req_post(req, ev);
        }

        host->servers = talloc_zero_array(
                host, struct rpc_server *, num_servers);
        if (tevent_req_nomem(host->servers, req)) {
                return tevent_req_post(req, ev);
        }

        se = tevent_add_signal(ev, state, SIGCHLD, 0, rpc_host_sigchld, host);
        if (tevent_req_nomem(se, req)) {
                return tevent_req_post(req, ev);
        }
        BlockSignals(false, SIGCHLD);

        status = messaging_register(
                msg_ctx,
                host,
                MSG_RPC_WORKER_STATUS,
                rpc_host_child_status_recv);
        if (tevent_req_nterror(req, status)) {
                return tevent_req_post(req, ev);
        }

        status = messaging_register(
                msg_ctx, req, MSG_SHUTDOWN, rpc_host_msg_shutdown);
        if (tevent_req_nterror(req, status)) {
                return tevent_req_post(req, ev);
        }

        subreq = messaging_filtered_read_send(
                state, ev, msg_ctx, rpc_host_ready_signal_filter, state);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }

        subreq = messaging_filtered_read_send(
                state, ev, msg_ctx, rpc_host_dump_status_filter, state);
        if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }

        epmdb_path = lock_path(state, "epmdb.tdb");
        if (tevent_req_nomem(epmdb_path, req)) {
                return tevent_req_post(req, ev);
        }

        host->epmdb = tdb_wrap_open(
                host,
                epmdb_path,
                0,
                TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
                O_RDWR|O_CREAT,
                0644);
        if (host->epmdb == NULL) {
                DBG_DEBUG("tdb_wrap_open(%s) failed: %s\n",
                          epmdb_path,
                          strerror(errno));
                tevent_req_nterror(req, map_nt_error_from_unix(errno));
                return tevent_req_post(req, ev);
        }
        TALLOC_FREE(epmdb_path);

        for (exe = strv_next(servers, exe), i = 0;
             exe != NULL;
             exe = strv_next(servers, exe), i++) {

                DBG_DEBUG("server_setup for %s index %zu\n", exe, i);

                subreq = rpc_server_setup_send(
                        state,
                        ev,
                        host,
                        exe);
                if (tevent_req_nomem(subreq, req)) {
                        return tevent_req_post(req, ev);
                }
                tevent_req_set_callback(
                        subreq, rpc_host_server_setup_done, req);
        }

        return req;
}

/*
 * Timer function called after we were initialized but no one
 * connected. Shutdown.
 */
static void rpc_host_shutdown(
        struct tevent_context *ev,
        struct tevent_timer *te,
        struct timeval current_time,
        void *private_data)
{
        struct tevent_req *req = talloc_get_type_abort(
                private_data, struct tevent_req);
        DBG_DEBUG("Nobody connected -- shutting down\n");
        tevent_req_done(req);
}

static void rpc_host_server_setup_done(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct rpc_host_state *state = tevent_req_data(
                req, struct rpc_host_state);
        struct rpc_server *server = NULL;
        struct rpc_host *host = state->host;
        size_t i, num_servers = talloc_array_length(host->servers);
        NTSTATUS status;

        status = rpc_server_setup_recv(subreq, host, &server);
        TALLOC_FREE(subreq);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("rpc_server_setup_recv returned %s, ignoring\n",
                          nt_errstr(status));
                host->servers = talloc_realloc(
                        host,
                        host->servers,
                        struct rpc_server *,
                        num_servers-1);
                return;
        }

        server->server_index = state->num_prepared;
        host->servers[state->num_prepared] = server;

        state->num_prepared += 1;

        if (state->num_prepared < num_servers) {
                return;
        }

        for (i=0; i<num_servers; i++) {
                size_t j, num_endpoints;

                server = host->servers[i];
                num_endpoints = talloc_array_length(server->endpoints);

                for (j=0; j<num_endpoints; j++) {
                        subreq = rpc_host_endpoint_accept_send(
                                state, state->ev, server->endpoints[j]);
                        if (tevent_req_nomem(subreq, req)) {
                                return;
                        }
                        tevent_req_set_callback(
                                subreq, rpc_host_endpoint_failed, req);
                }
        }

        state->is_ready = true;

        if (state->daemon_ready_progname != NULL) {
                daemon_ready(state->daemon_ready_progname);
        }

        if (host->np_helper) {
                /*
                 * If we're started as an np helper, and no one talks to
                 * us within 10 seconds, just shut ourselves down.
                 */
                host->np_helper_shutdown = tevent_add_timer(
                        state->ev,
                        state,
                        timeval_current_ofs(10, 0),
                        rpc_host_shutdown,
                        req);
                if (tevent_req_nomem(host->np_helper_shutdown, req)) {
                        return;
                }
        }

        tevent_schedule_immediate(
                state->ready_signal_immediate,
                state->ev,
                rpc_host_report_readiness,
                state);
}

/*
 * Log accept fail on an endpoint.
 */
static void rpc_host_endpoint_failed(struct tevent_req *subreq)
{
        struct tevent_req *req = tevent_req_callback_data(
                subreq, struct tevent_req);
        struct rpc_host_state *state = tevent_req_data(
                req, struct rpc_host_state);
        struct rpc_host_endpoint *endpoint = NULL;
        char *binding_string = NULL;
        int ret;

        ret = rpc_host_endpoint_accept_recv(subreq, &endpoint);
        TALLOC_FREE(subreq);

        binding_string = dcerpc_binding_string(state, endpoint->binding);
        DBG_DEBUG("rpc_host_endpoint_accept_recv for %s returned %s\n",
                  binding_string,
                  strerror(ret));
        TALLOC_FREE(binding_string);
}

static NTSTATUS rpc_host_recv(struct tevent_req *req)
{
        return tevent_req_simple_recv_ntstatus(req);
}

static int rpc_host_pidfile_create(
        struct messaging_context *msg_ctx,
        const char *progname,
        int ready_signal_fd)
{
        const char *piddir = lp_pid_directory();
        size_t len = strlen(piddir) + strlen(progname) + 6;
        char pidFile[len];
        pid_t existing_pid;
        int fd, ret;

        snprintf(pidFile,
                 sizeof(pidFile),
                 "%s/%s.pid",
                 piddir, progname);

        ret = pidfile_path_create(pidFile, &fd, &existing_pid);
        if (ret == 0) {
                /* leak fd */
                return 0;
        }

        if (ret != EAGAIN) {
                DBG_DEBUG("pidfile_path_create() failed: %s\n",
                          strerror(ret));
                return ret;
        }

        DBG_DEBUG("%s pid %d exists\n", progname, (int)existing_pid);

        if (ready_signal_fd != -1) {
                NTSTATUS status = messaging_send_iov(
                        msg_ctx,
                        pid_to_procid(existing_pid),
                        MSG_DAEMON_READY_FD,
                        NULL,
                        0,
                        &ready_signal_fd,
                        1);
                if (!NT_STATUS_IS_OK(status)) {
                        DBG_DEBUG("Could not send ready_signal_fd: %s\n",
                                  nt_errstr(status));
                }
        }

        return EAGAIN;
}

static void samba_dcerpcd_stdin_handler(
        struct tevent_context *ev,
        struct tevent_fd *fde,
        uint16_t flags,
        void *private_data)
{
        struct tevent_req *req = talloc_get_type_abort(
                private_data, struct tevent_req);
        char c;

        if (read(0, &c, 1) != 1) {
                /* we have reached EOF on stdin, which means the
                   parent has exited. Shutdown the server */
                tevent_req_done(req);
        }
}

/*
 * samba-dcerpcd microservice startup !
 */
int main(int argc, const char *argv[])
{
        const struct loadparm_substitution *lp_sub =
                loadparm_s3_global_substitution();
        const char *progname = getprogname();
        TALLOC_CTX *frame = NULL;
        struct tevent_context *ev_ctx = NULL;
        struct messaging_context *msg_ctx = NULL;
        struct tevent_req *req = NULL;
        char *servers = NULL;
        const char *arg = NULL;
        size_t num_servers;
        poptContext pc;
        int ret, err;
        NTSTATUS status;
        bool log_stdout;
        bool ok;

        int libexec_rpcds = 0;
        int np_helper = 0;
        int ready_signal_fd = -1;

        struct samba_cmdline_daemon_cfg *cmdline_daemon_cfg = NULL;
        struct poptOption long_options[] = {
                POPT_AUTOHELP
                {
                        .longName   = "libexec-rpcds",
                        .argInfo    = POPT_ARG_NONE,
                        .arg        = &libexec_rpcds,
                        .descrip    = "Use all rpcds in libexec",
                },
                {
                        .longName   = "ready-signal-fd",
                        .argInfo    = POPT_ARG_INT,
                        .arg        = &ready_signal_fd,
                        .descrip    = "fd to close when initialized",
                },
                {
                        .longName   = "np-helper",
                        .argInfo    = POPT_ARG_NONE,
                        .arg        = &np_helper,
                        .descrip    = "Internal named pipe server",
                },
                POPT_COMMON_SAMBA
                POPT_COMMON_DAEMON
                POPT_COMMON_VERSION
                POPT_TABLEEND
        };

        {
                const char *fd_params[] = { "ready-signal-fd", };

                closefrom_except_fd_params(
                        3, ARRAY_SIZE(fd_params), fd_params, argc, argv);
        }

        talloc_enable_null_tracking();
        frame = talloc_stackframe();
        umask(0);
        sec_init();
        smb_init_locale();

        ok = samba_cmdline_init(frame,
                                SAMBA_CMDLINE_CONFIG_SERVER,
                                true /* require_smbconf */);
        if (!ok) {
                DBG_ERR("Failed to init cmdline parser!\n");
                TALLOC_FREE(frame);
                exit(ENOMEM);
        }

        pc = samba_popt_get_context(getprogname(),
                                    argc,
                                    argv,
                                    long_options,
                                    0);
        if (pc == NULL) {
                DBG_ERR("Failed to setup popt context!\n");
                TALLOC_FREE(frame);
                exit(1);
        }

        poptSetOtherOptionHelp(
                pc, "[OPTIONS] [SERVICE_1 SERVICE_2 .. SERVICE_N]");

        ret = poptGetNextOpt(pc);

        if (ret != -1) {
                if (ret >= 0) {
                        fprintf(stderr,
                                "\nGot unexpected option %d\n",
                                ret);
                } else if (ret == POPT_ERROR_BADOPT) {
                        fprintf(stderr,
                                "\nInvalid option %s: %s\n\n",
                                poptBadOption(pc, 0),
                                poptStrerror(ret));
                } else {
                        fprintf(stderr,
                                "\npoptGetNextOpt returned %s\n",
                                poptStrerror(ret));
                }

                poptFreeContext(pc);
                TALLOC_FREE(frame);
                exit(1);
        }

        while ((arg = poptGetArg(pc)) != NULL) {
                ret = strv_add(frame, &servers, arg);
                if (ret != 0) {
                        DBG_ERR("strv_add() failed\n");
                        poptFreeContext(pc);
                        TALLOC_FREE(frame);
                        exit(1);
                }
        }

        log_stdout = (debug_get_log_type() == DEBUG_STDOUT);
        if (log_stdout) {
                setup_logging(progname, DEBUG_STDOUT);
        } else {
                setup_logging(progname, DEBUG_FILE);
        }

        /*
         * If "rpc start on demand helpers = true" in smb.conf we must
         * not start as standalone, only on demand from
         * local_np_connect() functions. Log an error message telling
         * the admin how to fix and then exit.
         */
        if (lp_rpc_start_on_demand_helpers() && np_helper == 0) {
                DBG_ERR("Cannot start in standalone mode if smb.conf "
                        "[global] setting "
                        "\"rpc start on demand helpers = true\" - "
                        "exiting\n");
                        TALLOC_FREE(frame);
                        exit(1);
        }

        if (libexec_rpcds != 0) {
                ret = rpc_host_list_servers(
                        dyn_SAMBA_LIBEXECDIR, frame, &servers);
                if (ret != 0) {
                        DBG_ERR("Could not list libexec: %s\n",
                                strerror(ret));
                        poptFreeContext(pc);
                        TALLOC_FREE(frame);
                        exit(1);
                }
        }

        num_servers = strv_count(servers);
        if (num_servers == 0) {
                poptPrintUsage(pc, stderr, 0);
                poptFreeContext(pc);
                TALLOC_FREE(frame);
                exit(1);
        }

        poptFreeContext(pc);

        cmdline_daemon_cfg = samba_cmdline_get_daemon_cfg();

        if (log_stdout && cmdline_daemon_cfg->fork) {
                DBG_ERR("Can't log to stdout unless in foreground\n");
                TALLOC_FREE(frame);
                exit(1);
        }

        msg_ctx = global_messaging_context();
        if (msg_ctx == NULL) {
                DBG_ERR("messaging_init() failed\n");
                TALLOC_FREE(frame);
                exit(1);
        }
        ev_ctx = messaging_tevent_context(msg_ctx);

        if (cmdline_daemon_cfg->fork) {
                become_daemon(
                        true,
                        cmdline_daemon_cfg->no_process_group,
                        log_stdout);

                status = reinit_after_fork(msg_ctx, ev_ctx, false);
                if (!NT_STATUS_IS_OK(status)) {
                        exit_daemon("reinit_after_fork() failed",
                                    map_errno_from_nt_status(status));
                }
        } else {
                DBG_DEBUG("Calling daemon_status\n");
                daemon_status(progname, "Starting process ... ");
        }

        BlockSignals(true, SIGPIPE);

        dump_core_setup(progname, lp_logfile(frame, lp_sub));

        reopen_logs();

        DEBUG(0, ("%s version %s started.\n",
                  progname,
                  samba_version_string()));
        DEBUGADD(0,("%s\n", COPYRIGHT_STARTUP_MESSAGE));

        (void)winbind_off();
        ok = init_guest_session_info(frame);
        (void)winbind_on();
        if (!ok) {
                DBG_ERR("init_guest_session_info failed\n");
                global_messaging_context_free();
                TALLOC_FREE(frame);
                exit(1);
        }

        ret = rpc_host_pidfile_create(msg_ctx, progname, ready_signal_fd);
        if (ret != 0) {
                DBG_DEBUG("rpc_host_pidfile_create failed: %s\n",
                          strerror(ret));
                global_messaging_context_free();
                TALLOC_FREE(frame);
                exit(1);
        }

        req = rpc_host_send(
                ev_ctx,
                ev_ctx,
                msg_ctx,
                servers,
                ready_signal_fd,
                cmdline_daemon_cfg->fork ? NULL : progname,
                np_helper != 0);
        if (req == NULL) {
                DBG_ERR("rpc_host_send failed\n");
                global_messaging_context_free();
                TALLOC_FREE(frame);
                exit(1);
        }

        if (!cmdline_daemon_cfg->fork) {
                struct stat st;
                if (fstat(0, &st) != 0) {
                        DBG_DEBUG("fstat(0) failed: %s\n",
                                  strerror(errno));
                        global_messaging_context_free();
                        TALLOC_FREE(frame);
                        exit(1);
                }
                if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode)) {
                        tevent_add_fd(
                                ev_ctx,
                                ev_ctx,
                                0,
                                TEVENT_FD_READ,
                                samba_dcerpcd_stdin_handler,
                                req);
                }
        }

        ok = tevent_req_poll_unix(req, ev_ctx, &err);
        if (!ok) {
                DBG_ERR("tevent_req_poll_unix failed: %s\n",
                        strerror(err));
                global_messaging_context_free();
                TALLOC_FREE(frame);
                exit(1);
        }

        status = rpc_host_recv(req);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_ERR("rpc_host_recv returned %s\n", nt_errstr(status));
                global_messaging_context_free();
                TALLOC_FREE(frame);
                exit(1);
        }

        TALLOC_FREE(frame);

        return 0;
}