libdns: Add dns_cli_request

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

/*
 *  Unix SMB/CIFS implementation.
 *
 *  mds service daemon
 *
 *  Copyright (c) 2014      Ralph Boehme <rb@sernet.de>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "includes.h"
#include "messages.h"
#include "ntdomain.h"

#include "lib/id_cache.h"

#include "../lib/tsocket/tsocket.h"
#include "lib/server_prefork.h"
#include "lib/server_prefork_util.h"
#include "librpc/rpc/dcerpc_ep.h"

#include "rpc_server/rpc_server.h"
#include "rpc_server/rpc_ep_register.h"
#include "rpc_server/rpc_sock_helper.h"
#include "rpc_server/rpc_modules.h"

#include "librpc/gen_ndr/srv_mdssvc.h"
#include "rpc_server/mdssvc/srv_mdssvc_nt.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_RPC_SRV

#define DAEMON_NAME "mdssd"
#define MDSSD_MAX_SOCKETS 64

static struct server_id parent_id;
static struct prefork_pool *mdssd_pool = NULL;
static int mdssd_child_id = 0;

static struct pf_daemon_config default_pf_mdssd_cfg = {
        .prefork_status = PFH_INIT,
        .min_children = 5,
        .max_children = 25,
        .spawn_rate = 5,
        .max_allowed_clients = 1000,
        .child_min_life = 60 /* 1 minute minimum life time */
};
static struct pf_daemon_config pf_mdssd_cfg = { 0 };

void start_mdssd(struct tevent_context *ev_ctx,
                 struct messaging_context *msg_ctx);

static void mdssd_smb_conf_updated(struct messaging_context *msg,
                                   void *private_data,
                                   uint32_t msg_type,
                                   struct server_id server_id,
                                   DATA_BLOB *data)
{
        struct tevent_context *ev_ctx;

        DEBUG(10, ("Got message saying smb.conf was updated. Reloading.\n"));
        ev_ctx = talloc_get_type_abort(private_data, struct tevent_context);

        change_to_root_user();
        lp_load_global(get_dyn_CONFIGFILE());

        reopen_logs();
        if (mdssd_child_id == 0) {
                pfh_daemon_config(DAEMON_NAME,
                                  &pf_mdssd_cfg,
                                  &default_pf_mdssd_cfg);
                pfh_manage_pool(ev_ctx, msg, &pf_mdssd_cfg, mdssd_pool);
        }
}

static void mdssd_sig_term_handler(struct tevent_context *ev,
                                   struct tevent_signal *se,
                                   int signum,
                                   int count,
                                   void *siginfo,
                                   void *private_data)
{
        shutdown_rpc_module("mdssvc");

        DEBUG(0, ("termination signal\n"));
        exit(0);
}

static void mdssd_setup_sig_term_handler(struct tevent_context *ev_ctx)
{
        struct tevent_signal *se;

        se = tevent_add_signal(ev_ctx,
                               ev_ctx,
                               SIGTERM, 0,
                               mdssd_sig_term_handler,
                               NULL);
        if (!se) {
                DEBUG(0, ("failed to setup SIGTERM handler\n"));
                exit(1);
        }
}

static void mdssd_sig_hup_handler(struct tevent_context *ev,
                                  struct tevent_signal *se,
                                  int signum,
                                  int count,
                                  void *siginfo,
                                  void *pvt)
{

        change_to_root_user();
        lp_load_global(get_dyn_CONFIGFILE());

        reopen_logs();
        pfh_daemon_config(DAEMON_NAME,
                          &pf_mdssd_cfg,
                          &default_pf_mdssd_cfg);

        /* relay to all children */
        prefork_send_signal_to_all(mdssd_pool, SIGHUP);
}

static void mdssd_setup_sig_hup_handler(struct tevent_context *ev_ctx)
{
        struct tevent_signal *se;

        se = tevent_add_signal(ev_ctx,
                               ev_ctx,
                               SIGHUP, 0,
                               mdssd_sig_hup_handler,
                               NULL);
        if (!se) {
                DEBUG(0, ("failed to setup SIGHUP handler\n"));
                exit(1);
        }
}

/**********************************************************
 * Children
 **********************************************************/

static void mdssd_chld_sig_hup_handler(struct tevent_context *ev,
                                       struct tevent_signal *se,
                                       int signum,
                                       int count,
                                       void *siginfo,
                                       void *pvt)
{
        change_to_root_user();
        reopen_logs();
}

static bool mdssd_setup_chld_hup_handler(struct tevent_context *ev_ctx)
{
        struct tevent_signal *se;

        se = tevent_add_signal(ev_ctx,
                               ev_ctx,
                               SIGHUP, 0,
                               mdssd_chld_sig_hup_handler,
                               NULL);
        if (!se) {
                DEBUG(1, ("failed to setup SIGHUP handler"));
                return false;
        }

        return true;
}

static void parent_ping(struct messaging_context *msg_ctx,
                        void *private_data,
                        uint32_t msg_type,
                        struct server_id server_id,
                        DATA_BLOB *data)
{
        /*
         * The fact we received this message is enough to let make the
         * event loop if it was idle. mdssd_children_main will cycle
         * through mdssd_next_client at least once. That function will
         * take whatever action is necessary
         */
        DEBUG(10, ("Got message that the parent changed status.\n"));
        return;
}

static bool mdssd_child_init(struct tevent_context *ev_ctx,
                             int child_id,
                             struct pf_worker_data *pf)
{
        NTSTATUS status;
        struct messaging_context *msg_ctx = server_messaging_context();
        bool ok;

        status = reinit_after_fork(msg_ctx, ev_ctx,
                                   true, "mdssd-child");
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0,("reinit_after_fork() failed\n"));
                smb_panic("reinit_after_fork() failed");
        }

        mdssd_child_id = child_id;
        reopen_logs();

        ok = mdssd_setup_chld_hup_handler(ev_ctx);
        if (!ok) {
                return false;
        }

        messaging_register(msg_ctx, ev_ctx,
                           MSG_SMB_CONF_UPDATED, mdssd_smb_conf_updated);
        messaging_register(msg_ctx, ev_ctx,
                           MSG_PREFORK_PARENT_EVENT, parent_ping);

        ok = init_rpc_module("mdssvc", NULL);
        if (!ok) {
                DBG_ERR("Failed to de-intialize RPC\n");
                return false;
        }

        return true;
}

struct mdssd_children_data {
        struct tevent_context *ev_ctx;
        struct messaging_context *msg_ctx;
        struct pf_worker_data *pf;
        int listen_fd_size;
        int *listen_fds;
};

static void mdssd_next_client(void *pvt);

static int mdssd_children_main(struct tevent_context *ev_ctx,
                               struct messaging_context *msg_ctx,
                               struct pf_worker_data *pf,
                               int child_id,
                               int listen_fd_size,
                               int *listen_fds,
                               void *private_data)
{
        struct mdssd_children_data *data;
        bool ok;
        int ret = 0;

        ok = mdssd_child_init(ev_ctx, child_id, pf);
        if (!ok) {
                return 1;
        }

        data = talloc(ev_ctx, struct mdssd_children_data);
        if (!data) {
                return 1;
        }
        data->pf = pf;
        data->ev_ctx = ev_ctx;
        data->msg_ctx = msg_ctx;
        data->listen_fd_size = listen_fd_size;
        data->listen_fds = listen_fds;

        /* loop until it is time to exit */
        while (pf->status != PF_WORKER_EXITING) {
                /* try to see if it is time to schedule the next client */
                mdssd_next_client(data);

                ret = tevent_loop_once(ev_ctx);
                if (ret != 0) {
                        DEBUG(0, ("tevent_loop_once() exited with %d: %s\n",
                                  ret, strerror(errno)));
                        pf->status = PF_WORKER_EXITING;
                }
        }

        return ret;
}

static void mdssd_client_terminated(void *pvt)
{
        struct mdssd_children_data *data;

        data = talloc_get_type_abort(pvt, struct mdssd_children_data);

        pfh_client_terminated(data->pf);

        mdssd_next_client(pvt);
}

struct mdssd_new_client {
        struct mdssd_children_data *data;
};

static void mdssd_handle_client(struct tevent_req *req);

static void mdssd_next_client(void *pvt)
{
        struct tevent_req *req;
        struct mdssd_children_data *data;
        struct mdssd_new_client *next;

        data = talloc_get_type_abort(pvt, struct mdssd_children_data);

        if (!pfh_child_allowed_to_accept(data->pf)) {
                /* nothing to do for now we are already listening
                 * or we are not allowed to listen further */
                return;
        }

        next = talloc_zero(data, struct mdssd_new_client);
        if (!next) {
                DEBUG(1, ("Out of memory!?\n"));
                return;
        }
        next->data = data;

        req = prefork_listen_send(next,
                                  data->ev_ctx,
                                  data->pf,
                                  data->listen_fd_size,
                                  data->listen_fds);
        if (!req) {
                DEBUG(1, ("Failed to make listening request!?\n"));
                talloc_free(next);
                return;
        }
        tevent_req_set_callback(req, mdssd_handle_client, next);
}

static void mdssd_handle_client(struct tevent_req *req)
{
        struct mdssd_children_data *data;
        struct mdssd_new_client *client;
        const DATA_BLOB ping = data_blob_null;
        int rc;
        int sd;
        TALLOC_CTX *tmp_ctx;
        struct tsocket_address *srv_addr;
        struct tsocket_address *cli_addr;

        client = tevent_req_callback_data(req, struct mdssd_new_client);
        data = client->data;

        tmp_ctx = talloc_stackframe();
        if (tmp_ctx == NULL) {
                DEBUG(1, ("Failed to allocate stackframe!\n"));
                return;
        }

        rc = prefork_listen_recv(req,
                                 tmp_ctx,
                                 &sd,
                                 &srv_addr,
                                 &cli_addr);

        /* this will free the request too */
        talloc_free(client);

        if (rc != 0) {
                DEBUG(6, ("No client connection was available after all!\n"));
                goto done;
        }

        /* Warn parent that our status changed */
        messaging_send(data->msg_ctx, parent_id,
                        MSG_PREFORK_CHILD_EVENT, &ping);

        DEBUG(2, ("mdssd preforked child %d got client connection!\n",
                  (int)(data->pf->pid)));

        if (tsocket_address_is_inet(srv_addr, "ip")) {
                DEBUG(3, ("Got a tcpip client connection from %s on inteface %s\n",
                           tsocket_address_string(cli_addr, tmp_ctx),
                           tsocket_address_string(srv_addr, tmp_ctx)));

                dcerpc_ncacn_accept(data->ev_ctx,
                                    data->msg_ctx,
                                    NCACN_IP_TCP,
                                    "IP",
                                    cli_addr,
                                    srv_addr,
                                    sd,
                                    NULL);
        } else if (tsocket_address_is_unix(srv_addr)) {
                const char *p;
                const char *b;

                p = tsocket_address_unix_path(srv_addr, tmp_ctx);
                if (p == NULL) {
                        talloc_free(tmp_ctx);
                        return;
                }

                b = strrchr(p, '/');
                if (b != NULL) {
                        b++;
                } else {
                        b = p;
                }

                if (strstr(p, "/np/")) {
                        named_pipe_accept_function(data->ev_ctx,
                                                   data->msg_ctx,
                                                   b,
                                                   sd,
                                                   mdssd_client_terminated,
                                                   data);
                } else {
                        dcerpc_ncacn_accept(data->ev_ctx,
                                            data->msg_ctx,
                                            NCALRPC,
                                            b,
                                            cli_addr,
                                            srv_addr,
                                            sd,
                                            NULL);
                }
        } else {
                DEBUG(0, ("ERROR: Unsupported socket!\n"));
        }

done:
        talloc_free(tmp_ctx);
}

/*
 * MAIN
 */

static void child_ping(struct messaging_context *msg_ctx,
                        void *private_data,
                        uint32_t msg_type,
                        struct server_id server_id,
                        DATA_BLOB *data)
{
        struct tevent_context *ev_ctx;

        ev_ctx = talloc_get_type_abort(private_data, struct tevent_context);

        DEBUG(10, ("Got message that a child changed status.\n"));
        pfh_manage_pool(ev_ctx, msg_ctx, &pf_mdssd_cfg, mdssd_pool);
}

static bool mdssd_schedule_check(struct tevent_context *ev_ctx,
                                 struct messaging_context *msg_ctx,
                                 struct timeval current_time);

static void mdssd_check_children(struct tevent_context *ev_ctx,
                                    struct tevent_timer *te,
                                    struct timeval current_time,
                                    void *pvt);

static void mdssd_sigchld_handler(struct tevent_context *ev_ctx,
                                  struct prefork_pool *pfp,
                                  void *pvt)
{
        struct messaging_context *msg_ctx;

        msg_ctx = talloc_get_type_abort(pvt, struct messaging_context);

        /* run pool management so we can fork/retire or increase
         * the allowed connections per child based on load */
        pfh_manage_pool(ev_ctx, msg_ctx, &pf_mdssd_cfg, mdssd_pool);
}

static bool mdssd_setup_children_monitor(struct tevent_context *ev_ctx,
                                         struct messaging_context *msg_ctx)
{
        bool ok;

        /* add our oun sigchld callback */
        prefork_set_sigchld_callback(mdssd_pool, mdssd_sigchld_handler, msg_ctx);

        ok = mdssd_schedule_check(ev_ctx, msg_ctx, tevent_timeval_current());

        return ok;
}

static bool mdssd_schedule_check(struct tevent_context *ev_ctx,
                                 struct messaging_context *msg_ctx,
                                 struct timeval current_time)
{
        struct tevent_timer *te;
        struct timeval next_event;

        /* check situation again in 10 seconds */
        next_event = tevent_timeval_current_ofs(10, 0);

        /* TODO: check when the socket becomes readable, so that children
         * are checked only when there is some activity ? */
        te = tevent_add_timer(ev_ctx, mdssd_pool, next_event,
                              mdssd_check_children, msg_ctx);
        if (!te) {
                DEBUG(2, ("Failed to set up children monitoring!\n"));
                return false;
        }

        return true;
}

static void mdssd_check_children(struct tevent_context *ev_ctx,
                                 struct tevent_timer *te,
                                 struct timeval current_time,
                                 void *pvt)
{
        struct messaging_context *msg_ctx;

        msg_ctx = talloc_get_type_abort(pvt, struct messaging_context);

        pfh_manage_pool(ev_ctx, msg_ctx, &pf_mdssd_cfg, mdssd_pool);

        mdssd_schedule_check(ev_ctx, msg_ctx, current_time);
}

/*
 * start it up
 */

static bool mdssd_create_sockets(struct tevent_context *ev_ctx,
                                 struct messaging_context *msg_ctx,
                                 int *listen_fd,
                                 int *listen_fd_size)
{
        struct dcerpc_binding_vector *v, *v_orig;
        TALLOC_CTX *tmp_ctx;
        NTSTATUS status;
        int fd = -1;
        int rc;
        bool ok = false;

        tmp_ctx = talloc_stackframe();
        if (tmp_ctx == NULL) {
                return false;
        }

        status = dcerpc_binding_vector_new(tmp_ctx, &v_orig);
        if (!NT_STATUS_IS_OK(status)) {
                goto done;
        }

        /* mdssvc */
        fd = create_named_pipe_socket("mdssvc");
        if (fd < 0) {
                goto done;
        }

        rc = listen(fd, pf_mdssd_cfg.max_allowed_clients);
        if (rc == -1) {
                goto done;
        }
        listen_fd[*listen_fd_size] = fd;
        (*listen_fd_size)++;

        fd = create_dcerpc_ncalrpc_socket("mdssvc");
        if (fd < 0) {
                goto done;
        }

        rc = listen(fd, pf_mdssd_cfg.max_allowed_clients);
        if (rc == -1) {
                goto done;
        }
        listen_fd[*listen_fd_size] = fd;
        (*listen_fd_size)++;
        fd = -1;

        v = dcerpc_binding_vector_dup(tmp_ctx, v_orig);
        if (v == NULL) {
                goto done;
        }

        status = dcerpc_binding_vector_replace_iface(&ndr_table_mdssvc, v);
        if (!NT_STATUS_IS_OK(status)) {
                goto done;
        }

        status = dcerpc_binding_vector_add_np_default(&ndr_table_mdssvc, v);
        if (!NT_STATUS_IS_OK(status)) {
                goto done;
        }

        status = dcerpc_binding_vector_add_unix(&ndr_table_mdssvc, v, "mdssvc");
        if (!NT_STATUS_IS_OK(status)) {
                goto done;
        }

        ok = true;
done:
        if (fd != -1) {
                close(fd);
        }
        talloc_free(tmp_ctx);
        return ok;
}

void start_mdssd(struct tevent_context *ev_ctx,
                 struct messaging_context *msg_ctx)
{
        NTSTATUS status;
        int listen_fd[MDSSD_MAX_SOCKETS];
        int listen_fd_size = 0;
        pid_t pid;
        int rc;
        bool ok;

        DEBUG(1, ("Forking Metadata Service Daemon\n"));

        /*
         * Block signals before forking child as it will have to
         * set its own handlers. Child will re-enable SIGHUP as
         * soon as the handlers are set up.
         */
        BlockSignals(true, SIGTERM);
        BlockSignals(true, SIGHUP);

        pid = fork();
        if (pid == -1) {
                DEBUG(0, ("Failed to fork mdssd [%s], aborting ...\n",
                           strerror(errno)));
                exit(1);
        }

        /* parent or error */
        if (pid != 0) {

                /* Re-enable SIGHUP before returnig */
                BlockSignals(false, SIGTERM);
                BlockSignals(false, SIGHUP);

                return;
        }

        status = smbd_reinit_after_fork(msg_ctx, ev_ctx, true, "mdssd-master");
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0,("reinit_after_fork() failed\n"));
                smb_panic("reinit_after_fork() failed");
        }

        reopen_logs();

        /* save the parent process id so the children can use it later */
        parent_id = messaging_server_id(msg_ctx);

        pfh_daemon_config(DAEMON_NAME,
                          &pf_mdssd_cfg,
                          &default_pf_mdssd_cfg);

        mdssd_setup_sig_term_handler(ev_ctx);
        mdssd_setup_sig_hup_handler(ev_ctx);

        BlockSignals(false, SIGTERM);
        BlockSignals(false, SIGHUP);

        ok = mdssd_create_sockets(ev_ctx, msg_ctx, listen_fd, &listen_fd_size);
        if (!ok) {
                exit(1);
        }

        /* start children before any more initialization is done */
        ok = prefork_create_pool(ev_ctx, /* mem_ctx */
                                 ev_ctx,
                                 msg_ctx,
                                 listen_fd_size,
                                 listen_fd,
                                 pf_mdssd_cfg.min_children,
                                 pf_mdssd_cfg.max_children,
                                 &mdssd_children_main,
                                 NULL,
                                 &mdssd_pool);
        if (!ok) {
                exit(1);
        }

        messaging_register(msg_ctx,
                           ev_ctx,
                           MSG_SMB_CONF_UPDATED,
                           mdssd_smb_conf_updated);
        messaging_register(msg_ctx, ev_ctx,
                           MSG_PREFORK_CHILD_EVENT, child_ping);

        ok = setup_rpc_module(ev_ctx, msg_ctx, "mdssvc");
        if (!ok) {
                exit(1);
        }

        ok = mdssd_setup_children_monitor(ev_ctx, msg_ctx);
        if (!ok) {
                exit(1);
        }

        DEBUG(1, ("mdssd Daemon Started (%u)\n", (unsigned int)getpid()));

        /* loop forever */
        rc = tevent_loop_wait(ev_ctx);

        /* should not be reached */
        DEBUG(0,("mdssd: tevent_loop_wait() exited with %d - %s\n",
                 rc, (rc == 0) ? "out of events" : strerror(errno)));
        exit(1);
}