/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2018 Nexenta Systems, Inc.  All rights reserved.
 * Copyright 2023 RackTop Systems, Inc.
 * Copyright 2025 Bill Sommerfeld
 */


/*
 * main() of idmapd(8)
 */

#include "idmapd.h"
#include <atomic.h>
#include <signal.h>
#include <rpc/pmap_clnt.h> /* for pmap_unset */
#include <string.h> /* strcmp */
#include <unistd.h> /* setsid */
#include <sys/types.h>
#include <memory.h>
#include <stropts.h>
#include <netconfig.h>
#include <sys/resource.h> /* rlimit */
#include <rpcsvc/daemon_utils.h> /* DAEMON_UID and DAEMON_GID */
#include <priv_utils.h> /* privileges */
#include <locale.h>
#include <sys/systeminfo.h>
#include <errno.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <zone.h>
#include <door.h>
#include <port.h>
#include <tsol/label.h>
#include <sys/resource.h>
#include <sys/sid.h>
#include <sys/idmap.h>
#include <pthread.h>
#include <stdarg.h>
#include <assert.h>
#include <note.h>

#define CBUFSIZ 26      /* ctime(3c) */

static void     term_handler(int);
static void     init_idmapd();
static void     fini_idmapd();

/* The DC Locator lives inside idmap (for now). */
extern void     init_dc_locator(void);
extern void     fini_dc_locator(void);

idmapd_state_t  _idmapdstate;
mutex_t _svcstate_lock = ERRORCHECKMUTEX;

SVCXPRT *xprt = NULL;

static int dfd = -1;            /* our door server fildes, for unregistration */
static boolean_t degraded = B_FALSE;


static uint32_t         num_threads = 0;
static pthread_key_t    create_threads_key;
static uint32_t         max_threads = 40;

/*
 * Server door thread start routine.
 *
 * Set a TSD value to the door thread. This enables the destructor to
 * be called when this thread exits. Note that we need a non-NULL
 * value for this or the TSD destructor is not called.
 */
/*ARGSUSED*/
static void *
idmapd_door_thread_start(void *arg)
{
        static void *value = "NON-NULL TSD";

        /*
         * Disable cancellation to avoid memory leaks from not running
         * the thread cleanup code.
         */
        (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
        (void) pthread_setspecific(create_threads_key, value);
        (void) door_return(NULL, 0, NULL, 0);

        /* make lint happy */
        return (NULL);
}

/*
 * Server door threads creation
 */
/*ARGSUSED*/
static void
idmapd_door_thread_create(door_info_t *dip)
{
        int             num;
        pthread_t       thread_id;

        if ((num = atomic_inc_32_nv(&num_threads)) > max_threads) {
                atomic_dec_32(&num_threads);
                idmapdlog(LOG_DEBUG,
                    "thread creation refused - %d threads currently active",
                    num - 1);
                return;
        }
        (void) pthread_create(&thread_id, NULL, idmapd_door_thread_start, NULL);
        idmapdlog(LOG_DEBUG,
            "created thread ID %d - %d threads currently active",
            thread_id, num);
}

/*
 * Server door thread cleanup
 */
/*ARGSUSED*/
static void
idmapd_door_thread_cleanup(void *arg)
{
        int num;

        /* set TSD to NULL so we don't loop infinitely */
        (void) pthread_setspecific(create_threads_key, NULL);
        num = atomic_dec_32_nv(&num_threads);
        idmapdlog(LOG_DEBUG,
            "exiting thread ID %d - %d threads currently active",
            pthread_self(), num);
}

/*
 * This is needed for mech_krb5 -- we run as daemon, yes, but we want
 * mech_krb5 to think we're root so it can get host/nodename.fqdn
 * tickets for us so we can authenticate to AD as the machine account
 * that we are.  For more details look at the entry point in mech_krb5
 * corresponding to gss_init_sec_context().
 *
 * As a side effect of faking our effective UID to mech_krb5 we will use
 * root's default ccache (/tmp/krb5cc_0).  But if that's created by
 * another process then we won't have access to it: we run as daemon and
 * keep PRIV_FILE_DAC_READ, which is insufficient to share the ccache
 * with others.  We putenv("KRB5CCNAME=/var/run/idmap/ccache") in main()
 * to avoid this issue; see main().
 *
 * Someday we'll have gss/mech_krb5 extensions for acquiring initiator
 * creds with keytabs/raw keys, and someday we'll have extensions to
 * libsasl to specify creds/name to use on the initiator side, and
 * someday we'll have extensions to libldap to pass those through to
 * libsasl.  Until then this interposer will have to do.
 *
 * Also, we have to tell lint to shut up: it thinks app_krb5_user_uid()
 * is defined but not used.
 */
/*LINTLIBRARY*/
uid_t
app_krb5_user_uid(void)
{
        return (0);
}

/*ARGSUSED*/
static void
term_handler(int sig)
{
        idmapdlog(LOG_INFO, "Terminating.");
        fini_dc_locator();
        fini_idmapd();
        _exit(0);
}

/*ARGSUSED*/
static void
usr1_handler(int sig)
{
        NOTE(ARGUNUSED(sig))
        print_idmapdstate();
}

static int pipe_fd = -1;

static void
daemonize_ready(void)
{
        char data = '\0';
        /*
         * wake the parent
         */
        (void) write(pipe_fd, &data, 1);
        (void) close(pipe_fd);
}

static int
daemonize_start(void)
{
        char    data;
        int     status;
        int     devnull;
        int     filedes[2];
        pid_t   pid;

        (void) sigset(SIGPIPE, SIG_IGN);
        devnull = open("/dev/null", O_RDONLY);
        if (devnull < 0)
                return (-1);
        (void) dup2(devnull, 0);
        (void) dup2(2, 1);      /* stderr only */
        if (pipe(filedes) < 0)
                return (-1);
        if ((pid = fork1()) < 0)
                return (-1);
        if (pid != 0) {
                /*
                 * parent
                 */
                (void) close(filedes[1]);
                if (read(filedes[0], &data, 1) == 1) {
                        /* presume success */
                        _exit(0);
                }
                status = -1;
                (void) wait4(pid, &status, 0, NULL);
                if (WIFEXITED(status))
                        _exit(WEXITSTATUS(status));
                else
                        _exit(-1);
        }

        /*
         * child
         */
        pipe_fd = filedes[1];
        (void) close(filedes[0]);
        (void) setsid();
        (void) umask(0077);
        openlog("idmap", LOG_PID, LOG_DAEMON);

        return (0);
}


int
main(int argc, char **argv)
{
        int c;
        struct rlimit rl;

        if (rwlock_init(&_idmapdstate.rwlk_cfg, USYNC_THREAD, NULL) != 0)
                return (-1);
        if (mutex_init(&_idmapdstate.addisc_lk, USYNC_THREAD, NULL) != 0)
                return (-1);
        if (cond_init(&_idmapdstate.addisc_cv, USYNC_THREAD, NULL) != 0)
                return (-1);

        _idmapdstate.daemon_mode = TRUE;
        while ((c = getopt(argc, argv, "d")) != -1) {
                switch (c) {
                        case 'd':
                                _idmapdstate.daemon_mode = FALSE;
                                break;
                        default:
                                (void) fprintf(stderr,
                                    "Usage: /usr/lib/idmapd [-d]\n");
                                return (SMF_EXIT_ERR_CONFIG);
                }
        }

        /* set locale and domain for internationalization */
        (void) setlocale(LC_ALL, "");
        (void) textdomain(TEXT_DOMAIN);

        idmap_set_logger(idmapdlog);
        adutils_set_logger(idmapdlog);

        if (is_system_labeled() && getzoneid() != GLOBAL_ZONEID) {
                idmapdlog(LOG_ERR,
                    "with Trusted Extensions idmapd runs only in the "
                    "global zone");
                exit(1);
        }

        /*
         * Raise the fd limit to max
         */
        if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
                idmapdlog(LOG_ERR, "getrlimit failed");
        } else if (rl.rlim_cur < rl.rlim_max) {
                rl.rlim_cur = rl.rlim_max;
                if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
                        idmapdlog(LOG_ERR,
                            "Unable to raise RLIMIT_NOFILE to %d",
                            rl.rlim_cur);
        }

        if (_idmapdstate.daemon_mode == TRUE) {
                if (daemonize_start() < 0) {
                        idmapdlog(LOG_ERR, "unable to daemonize");
                        exit(-1);
                }
        } else
                (void) umask(0077);

        idmap_init_tsd_key();

        init_idmapd();
        init_dc_locator();

        /* signal handlers that should run only after we're initialized */
        (void) sigset(SIGTERM, term_handler);
        (void) sigset(SIGUSR1, usr1_handler);
        (void) sigset(SIGHUP, idmap_cfg_hup_handler);

        if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
            DAEMON_UID, DAEMON_GID,
            PRIV_PROC_AUDIT, PRIV_FILE_DAC_READ,
            (char *)NULL) == -1) {
                idmapdlog(LOG_ERR, "unable to drop privileges");
                exit(1);
        }

        __fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
            PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);

        if (_idmapdstate.daemon_mode == TRUE)
                daemonize_ready();

        /* With doors RPC this just wastes this thread, oh well */
        svc_run();
        return (0);
}

static void
init_idmapd()
{
        int     error;
        int     connmaxrec = IDMAP_MAX_DOOR_RPC;


        /* create directories as root and chown to daemon uid */
        if (create_directory(IDMAP_DBDIR, DAEMON_UID, DAEMON_GID) < 0)
                exit(1);
        if (create_directory(IDMAP_CACHEDIR, DAEMON_UID, DAEMON_GID) < 0)
                exit(1);

        /*
         * Set KRB5CCNAME in the environment.  See app_krb5_user_uid()
         * for more details.  We blow away the existing one, if there is
         * one.
         */
        (void) unlink(IDMAP_CACHEDIR "/ccache");
        (void) putenv("KRB5CCNAME=" IDMAP_CACHEDIR "/ccache");
        (void) putenv("MS_INTEROP=1");

        if (sysinfo(SI_HOSTNAME, _idmapdstate.hostname,
            sizeof (_idmapdstate.hostname)) == -1) {
                error = errno;
                idmapdlog(LOG_ERR, "unable to determine hostname, error: %d",
                    error);
                exit(1);
        }

        if ((error = init_mapping_system()) < 0) {
                idmapdlog(LOG_ERR, "unable to initialize mapping system");
                exit(error < -2 ? SMF_EXIT_ERR_CONFIG : 1);
        }

        /*
         * This means max_threads can't be updated without restarting idmap.
         */
        RDLOCK_CONFIG();
        max_threads = _idmapdstate.cfg->pgcfg.max_threads;
        UNLOCK_CONFIG();

        (void) door_server_create(idmapd_door_thread_create);
        if ((error = pthread_key_create(&create_threads_key,
            idmapd_door_thread_cleanup)) != 0) {
                idmapdlog(LOG_ERR, "unable to create threads key (%s)",
                    strerror(error));
                goto errout;
        }

        xprt = svc_door_create(idmap_prog_1, IDMAP_PROG, IDMAP_V1, connmaxrec);
        if (xprt == NULL) {
                idmapdlog(LOG_ERR, "unable to create door RPC service");
                goto errout;
        }

        if (!svc_control(xprt, SVCSET_CONNMAXREC, &connmaxrec)) {
                idmapdlog(LOG_ERR, "unable to limit RPC request size");
                goto errout;
        }

        dfd = xprt->xp_fd;

        if (dfd == -1) {
                idmapdlog(LOG_ERR, "unable to register door");
                goto errout;
        }
        if ((error = __idmap_reg(dfd)) != 0) {
                idmapdlog(LOG_ERR, "unable to register door (%s)",
                    strerror(errno));
                goto errout;
        }

        pthread_mutex_init(&_idmapdstate.id_lock, NULL);

        if ((error = allocids(_idmapdstate.new_eph_db,
            8192, &_idmapdstate.next_uid,
            8192, &_idmapdstate.next_gid)) != 0) {
                idmapdlog(LOG_ERR, "unable to allocate ephemeral IDs (%s)",
                    strerror(errno));
                _idmapdstate.next_uid = IDMAP_SENTINEL_PID;
                _idmapdstate.limit_uid = IDMAP_SENTINEL_PID;
                _idmapdstate.next_gid = IDMAP_SENTINEL_PID;
                _idmapdstate.limit_gid = IDMAP_SENTINEL_PID;
        } else {
                _idmapdstate.limit_uid = _idmapdstate.next_uid + 8192;
                _idmapdstate.limit_gid = _idmapdstate.next_gid + 8192;
        }

        if (DBG(CONFIG, 1))
                print_idmapdstate();

        return;

errout:
        fini_idmapd();
        exit(1);
}

static void
fini_idmapd()
{
        (void) __idmap_unreg(dfd);
        fini_mapping_system();
        if (xprt != NULL)
                svc_destroy(xprt);
}

static
const char *
get_fmri(void)
{
        static char *fmri = NULL;
        static char buf[60];
        char *s;

        membar_consumer();
        s = fmri;
        if (s != NULL && *s == '\0')
                return (NULL);
        else if (s != NULL)
                return (s);

        if ((s = getenv("SMF_FMRI")) == NULL || strlen(s) >= sizeof (buf))
                buf[0] = '\0';
        else
                (void) strlcpy(buf, s, sizeof (buf));

        membar_producer();
        fmri = buf;

        return (get_fmri());
}

/*
 * Wrappers for smf_degrade/restore_instance()
 *
 * smf_restore_instance() is too heavy duty to be calling every time we
 * have a successful AD name<->SID lookup.
 */
void
degrade_svc(int poke_discovery, const char *reason)
{
        const char *fmri;

        membar_consumer();
        if (degraded)
                return;

        idmapdlog(LOG_ERR, "Degraded operation (%s).", reason);

        membar_producer();
        degraded = B_TRUE;

        if ((fmri = get_fmri()) != NULL)
                (void) smf_degrade_instance(fmri, 0);

        /*
         * If the config update thread is in a state where auto-discovery could
         * be re-tried, then this will make it try it -- a sort of auto-refresh.
         */
        if (poke_discovery)
                idmap_cfg_poke_updates();
}

void
restore_svc(void)
{
        const char *fmri;

        membar_consumer();
        if (!degraded)
                return;

        if ((fmri = get_fmri()) == NULL)
                (void) smf_restore_instance(fmri);

        membar_producer();
        degraded = B_FALSE;

        idmapdlog(LOG_NOTICE, "Normal operation restored");
}


/* printflike */
void
idmapdlog(int pri, const char *format, ...)
{
        static time_t prev_ts;
        va_list args;
        char cbuf[CBUFSIZ];
        time_t ts;

        ts = time(NULL);
        if (prev_ts != ts) {
                prev_ts = ts;
                /* NB: cbuf has \n */
                (void) fprintf(stderr, "@ %s",
                    ctime_r(&ts, cbuf, sizeof (cbuf)));
        }

        va_start(args, format);
        (void) vfprintf(stderr, format, args);
        (void) fprintf(stderr, "\n");
        va_end(args);

        /*
         * We don't want to fill up the logs with useless messages when
         * we're degraded, but we still want to log.
         */
        if (degraded)
                pri = LOG_DEBUG;

        va_start(args, format);
        vsyslog(pri, format, args);
        va_end(args);
}

static void
trace_str(nvlist_t *entry, char *n1, char *n2, char *str)
{
        char name[IDMAP_TRACE_NAME_MAX+1];      /* Max used is only about 11 */

        (void) strlcpy(name, n1, sizeof (name));
        if (n2 != NULL)
                (void) strlcat(name, n2, sizeof (name));

        (void) nvlist_add_string(entry, name, str);
}

static void
trace_int(nvlist_t *entry, char *n1, char *n2, int64_t i)
{
        char name[IDMAP_TRACE_NAME_MAX+1];      /* Max used is only about 11 */

        (void) strlcpy(name, n1, sizeof (name));
        if (n2 != NULL)
                (void) strlcat(name, n2, sizeof (name));

        (void) nvlist_add_int64(entry, name, i);
}

static void
trace_sid(nvlist_t *entry, char *n1, char *n2, idmap_sid *sid)
{
        char *str;

        (void) asprintf(&str, "%s-%u", sid->prefix, sid->rid);
        if (str == NULL)
                return;

        trace_str(entry, n1, n2, str);
        free(str);
}

static void
trace_id(nvlist_t *entry, char *fromto, idmap_id *id, char *name, char *domain)
{
        trace_int(entry, fromto, IDMAP_TRACE_TYPE, (int64_t)id->idtype);
        if (IS_ID_SID(*id)) {
                if (name != NULL) {
                        char *str;

                        (void) asprintf(&str, "%s%s%s", name,
                            domain == NULL ? "" : "@",
                            domain == NULL ? "" : domain);
                        if (str != NULL) {
                                trace_str(entry, fromto, IDMAP_TRACE_NAME, str);
                                free(str);
                        }
                }
                if (id->idmap_id_u.sid.prefix != NULL) {
                        trace_sid(entry, fromto, IDMAP_TRACE_SID,
                            &id->idmap_id_u.sid);
                }
        } else if (IS_ID_POSIX(*id)) {
                if (name != NULL)
                        trace_str(entry, fromto, IDMAP_TRACE_NAME, name);
                if (id->idmap_id_u.uid != IDMAP_SENTINEL_PID) {
                        trace_int(entry, fromto, IDMAP_TRACE_UNIXID,
                            (int64_t)id->idmap_id_u.uid);
                }
        }
}

/*
 * Record a trace event.  TRACE() has already decided whether or not
 * tracing is required; what we do here is collect the data and send it
 * to its destination - to the trace log in the response, if
 * IDMAP_REQ_FLG_TRACE is set, and to the SMF service log, if debug/mapping
 * is greater than zero.
 */
int
trace(idmap_mapping *req, idmap_id_res *res, char *fmt, ...)
{
        va_list va;
        char *buf;
        int err;
        nvlist_t *entry;

        assert(req != NULL);
        assert(res != NULL);

        err = nvlist_alloc(&entry, NV_UNIQUE_NAME, 0);
        if (err != 0) {
                (void) fprintf(stderr, "trace nvlist_alloc(entry):  %s\n",
                    strerror(err));
                return (0);
        }

        trace_id(entry, "from", &req->id1, req->id1name, req->id1domain);
        trace_id(entry, "to", &res->id, req->id2name, req->id2domain);

        if (IDMAP_ERROR(res->retcode)) {
                trace_int(entry, IDMAP_TRACE_ERROR, NULL,
                    (int64_t)res->retcode);
        }

        va_start(va, fmt);
        (void) vasprintf(&buf, fmt, va);
        va_end(va);
        if (buf != NULL) {
                trace_str(entry, IDMAP_TRACE_MESSAGE, NULL, buf);
                free(buf);
        }

        if (DBG(MAPPING, 1))
                idmap_trace_print_1(stderr, "", entry);

        if (req->flag & IDMAP_REQ_FLG_TRACE) {
                /* Lazily allocate the trace list */
                if (res->info.trace == NULL) {
                        err = nvlist_alloc(&res->info.trace, 0, 0);
                        if (err != 0) {
                                res->info.trace = NULL; /* just in case */
                                (void) fprintf(stderr,
                                    "trace nvlist_alloc(trace):  %s\n",
                                    strerror(err));
                                nvlist_free(entry);
                                return (0);
                        }
                }
                (void) nvlist_add_nvlist(res->info.trace, "", entry);
                /* Note that entry is copied, so we must still free our copy */
        }

        nvlist_free(entry);

        return (0);
}

/*
 * Enable libumem debugging by default on DEBUG builds.
 * idmapd uses rpcgen, so we can't use #ifdef DEBUG without causing
 * undesirable behavior.
 */
#ifdef IDMAPD_DEBUG
const char *
_umem_debug_init(void)
{
        return ("default,verbose"); /* $UMEM_DEBUG setting */
}

const char *
_umem_logging_init(void)
{
        return ("fail,contents"); /* $UMEM_LOGGING setting */
}
#endif