nfs/statd/sm_proc.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2015 Nexenta Systems, Inc.  All rights reserved.
 */

/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright (c) 2012 by Delphix. All rights reserved.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <syslog.h>
#include <rpc/rpc.h>
#include <rpcsvc/sm_inter.h>
#include <rpcsvc/nsm_addr.h>
#include <memory.h>
#include <net/if.h>
#include <sys/sockio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <netdir.h>
#include <synch.h>
#include <thread.h>
#include <ifaddrs.h>
#include <errno.h>
#include <assert.h>
#include "sm_statd.h"

static int local_state;     /* fake local sm state */
                /* client name-to-address translation table */
static name_addr_entry_t *name_addr = NULL;


#define LOGHOST "loghost"

static void delete_mon(char *mon_name, my_id *my_idp);
static void insert_mon(mon *monp);
static void pr_mon(char *);
static int statd_call_lockd(mon *monp, int state);
static int hostname_eq(char *host1, char *host2);
static char *get_system_id(char *hostname);
static void add_aliases(struct hostent *phost);
static void *thr_send_notice(void *);
static void delete_onemon(char *mon_name, my_id *my_idp,
                mon_entry **monitor_q);
static void send_notice(char *mon_name, int state);
static void add_to_host_array(char *host);
static int in_host_array(char *host);
static void pr_name_addr(name_addr_entry_t *name_addr);

extern int self_check(char *hostname);
extern struct lifconf *getmyaddrs(void);

/* ARGSUSED */
void
sm_stat_svc(sm_name *namep, sm_stat_res *resp)
{

    if (debug)
        (void) printf("proc sm_stat: mon_name = %s\n",
            namep->mon_name);

    resp->res_stat = stat_succ;
    resp->state = LOCAL_STATE;
}

/* ARGSUSED */
void
sm_mon_svc(mon *monp, sm_stat_res *resp)
{
    mon_id *monidp;
    monidp = &monp->mon_id;

    rw_rdlock(&thr_rwlock);
    if (debug) {
        (void) printf("proc sm_mon: mon_name = %s, id = %d\n",
            monidp->mon_name, *((int *)monp->priv));
        pr_mon(monp->mon_id.mon_name);
    }

    /* only monitor other hosts */
    if (self_check(monp->mon_id.mon_name) == 0) {
        /* store monitor request into monitor_q */
        insert_mon(monp);
    }

    pr_mon(monp->mon_id.mon_name);
    resp->res_stat = stat_succ;
    resp->state = local_state;
    rw_unlock(&thr_rwlock);
}

/* ARGSUSED */
void
sm_unmon_svc(mon_id *monidp, sm_stat *resp)
{
    rw_rdlock(&thr_rwlock);
    if (debug) {
        (void) printf(
            "proc sm_unmon: mon_name = %s, [%s, %d, %d, %d]\n",
            monidp->mon_name, monidp->my_id.my_name,
            monidp->my_id.my_prog, monidp->my_id.my_vers,
            monidp->my_id.my_proc);
        pr_mon(monidp->mon_name);
    }

    delete_mon(monidp->mon_name, &monidp->my_id);
    pr_mon(monidp->mon_name);
    resp->state = local_state;
    rw_unlock(&thr_rwlock);
}

/* ARGSUSED */
void
sm_unmon_all_svc(my_id *myidp, sm_stat *resp)
{
    rw_rdlock(&thr_rwlock);
    if (debug)
        (void) printf("proc sm_unmon_all: [%s, %d, %d, %d]\n",
            myidp->my_name,
            myidp->my_prog, myidp->my_vers,
            myidp->my_proc);
    delete_mon(NULL, myidp);
    pr_mon(NULL);
    resp->state = local_state;
    rw_unlock(&thr_rwlock);
}

/*
 * Notifies lockd specified by name that state has changed for this server.
 */
void
sm_notify_svc(stat_chge *ntfp)
{
    rw_rdlock(&thr_rwlock);
    if (debug)
        (void) printf("sm_notify: %s state =%d\n",
            ntfp->mon_name, ntfp->state);
    send_notice(ntfp->mon_name, ntfp->state);
    rw_unlock(&thr_rwlock);
}

/* ARGSUSED */
void
sm_simu_crash_svc(void *myidp)
{
    int i;
    struct mon_entry *monitor_q;
    int found = 0;

    if (debug)
        (void) printf("proc sm_simu_crash\n");

    /* Only one crash should be running at a time. */
    mutex_lock(&crash_lock);
    if (in_crash != 0) {
        mutex_unlock(&crash_lock);
        return;
    }
    in_crash = 1;
    mutex_unlock(&crash_lock);

    for (i = 0; i < MAX_HASHSIZE; i++) {
        mutex_lock(&mon_table[i].lock);
        monitor_q = mon_table[i].sm_monhdp;
        if (monitor_q != NULL) {
            mutex_unlock(&mon_table[i].lock);
            found = 1;
            break;
        }
        mutex_unlock(&mon_table[i].lock);
    }
    /*
     * If there are entries found in the monitor table,
     * initiate a crash, else zero out the in_crash variable.
     */
    if (found) {
        mutex_lock(&crash_lock);
        die = 1;
        /* Signal sm_try() thread if sleeping. */
        cond_signal(&retrywait);
        mutex_unlock(&crash_lock);
        rw_wrlock(&thr_rwlock);
        sm_crash();
        rw_unlock(&thr_rwlock);
    } else {
        mutex_lock(&crash_lock);
        in_crash = 0;
        mutex_unlock(&crash_lock);
    }
}

/* ARGSUSED */
void
nsmaddrproc1_reg(reg1args *regargs, reg1res *regresp)
{
    nsm_addr_res status;
    name_addr_entry_t *entry;
    char *tmp_n_bytes;
    addr_entry_t *addr;

    rw_rdlock(&thr_rwlock);
    if (debug) {
        int i;

        (void) printf("nap1_reg: fam= %d, name= %s, len= %d\n",
            regargs->family, regargs->name, regargs->address.n_len);
        (void) printf("address is: ");
        for (i = 0; i < regargs->address.n_len; i++) {
            (void) printf("%d.",
                (unsigned char)regargs->address.n_bytes[i]);
        }
        (void) printf("\n");
    }

    /*
     * Locate the entry with the name in the NSM_ADDR_REG request if
     * it exists.  If it doesn't, create a new entry to hold this name.
     * The first time through this code, name_addr starts out as NULL.
     */
    mutex_lock(&name_addrlock);
    for (entry = name_addr; entry; entry = entry->next) {
        if (strcmp(regargs->name, entry->name) == 0) {
            if (debug) {
                (void) printf("nap1_reg: matched name %s\n",
                    entry->name);
            }
            break;
        }
    }

    if (entry == NULL) {
        entry = (name_addr_entry_t *)malloc(sizeof (*entry));
        if (entry == NULL) {
            if (debug) {
                (void) printf(
                "nsmaddrproc1_reg: no memory for entry\n");
            }
            status = nsm_addr_fail;
            goto done;
        }

        entry->name = strdup(regargs->name);
        if (entry->name == NULL) {
            if (debug) {
                (void) printf(
                "nsmaddrproc1_reg: no memory for name\n");
            }
            free(entry);
            status = nsm_addr_fail;
            goto done;
        }
        entry->addresses = NULL;

        /*
         * Link the new entry onto the *head* of the name_addr
         * table.
         *
         * Note: there is code below in the address maintenance
         * section that assumes this behavior.
         */
        entry->next = name_addr;
        name_addr = entry;
    }

    /*
     * Try to match the address in the request; if it doesn't match,
     * add it to the entry's address list.
     */
    for (addr = entry->addresses; addr; addr = addr->next) {
        if (addr->family == (sa_family_t)regargs->family &&
            addr->ah.n_len == regargs->address.n_len &&
            memcmp(addr->ah.n_bytes, regargs->address.n_bytes,
            addr->ah.n_len) == 0) {
            if (debug) {
                int i;

                (void) printf("nap1_reg: matched addr ");
                for (i = 0; i < addr->ah.n_len; i++) {
                    (void) printf("%d.",
                        (unsigned char)addr->ah.n_bytes[i]);
                }
                (void) printf(" family %d for name %s\n",
                    addr->family, entry->name);
            }
            break;
        }
    }

    if (addr == NULL) {
        addr = (addr_entry_t *)malloc(sizeof (*addr));
        tmp_n_bytes = (char *)malloc(regargs->address.n_len);
        if (addr == NULL || tmp_n_bytes == NULL) {
            if (debug) {
                (void) printf("nap1_reg: no memory for addr\n");
            }

            /*
             * If this name entry was just newly made in the
             * table, back it out now that we can't register
             * an address with it anyway.
             *
             * Note: we are making an assumption about how
             * names are added to (the head of) name_addr here.
             */
            if (entry == name_addr && entry->addresses == NULL) {
                name_addr = name_addr->next;
                free(entry->name);
                free(entry);
                if (tmp_n_bytes)
                    free(tmp_n_bytes);
                if (addr)
                    free(addr);
                status = nsm_addr_fail;
                goto done;
            }
        }

        /*
         * Note:  this check for address family assumes that we
         *    will get something different here someday for
         *    other supported address types, such as IPv6.
         */
        addr->ah.n_len = regargs->address.n_len;
        addr->ah.n_bytes = tmp_n_bytes;
        addr->family = regargs->family;
        if (debug) {
            if ((addr->family != AF_INET) &&
                (addr->family != AF_INET6)) {
                (void) printf(
                    "nap1_reg: unknown addr family %d\n",
                    addr->family);
            }
        }
        (void) memcpy(addr->ah.n_bytes, regargs->address.n_bytes,
            addr->ah.n_len);

        addr->next = entry->addresses;
        entry->addresses = addr;
    }

    status = nsm_addr_succ;

done:
    regresp->status = status;
    if (debug) {
        pr_name_addr(name_addr);
    }
    mutex_unlock(&name_addrlock);
    rw_unlock(&thr_rwlock);
}

/*
 * Insert an entry into the monitor_q.  Space for the entry is allocated
 * here.  It is then filled in from the information passed in.
 */
static void
insert_mon(mon *monp)
{
    mon_entry *new, *found;
    my_id *my_idp, *nl_idp;
    mon_entry *monitor_q;
    unsigned int hash;
    name_addr_entry_t *entry;
    addr_entry_t *addr;

    /* Allocate entry for new */
    if ((new = (mon_entry *) malloc(sizeof (mon_entry))) == 0) {
        syslog(LOG_ERR,
            "statd: insert_mon: malloc error on mon %s (id=%d)\n",
            monp->mon_id.mon_name, *((int *)monp->priv));
        return;
    }

    /* Initialize and copy contents of monp to new */
    (void) memset(new, 0, sizeof (mon_entry));
    (void) memcpy(&new->id, monp, sizeof (mon));

    /* Allocate entry for new mon_name */
    if ((new->id.mon_id.mon_name = strdup(monp->mon_id.mon_name)) == 0) {
        syslog(LOG_ERR,
            "statd: insert_mon: malloc error on mon %s (id=%d)\n",
            monp->mon_id.mon_name, *((int *)monp->priv));
        free(new);
        return;
    }


    /* Allocate entry for new my_name */
    if ((new->id.mon_id.my_id.my_name =
        strdup(monp->mon_id.my_id.my_name)) == 0) {
        syslog(LOG_ERR,
            "statd: insert_mon: malloc error on mon %s (id=%d)\n",
            monp->mon_id.mon_name, *((int *)monp->priv));
        free(new->id.mon_id.mon_name);
        free(new);
        return;
    }

    if (debug)
        (void) printf("add_mon(%x) %s (id=%d)\n",
            (int)new, new->id.mon_id.mon_name, *((int *)new->id.priv));

    /*
     * Record the name, and all addresses which have been registered
     * for this name, in the filesystem name space.
     */
    record_name(new->id.mon_id.mon_name, 1);
    if (regfiles_only == 0) {
        mutex_lock(&name_addrlock);
        for (entry = name_addr; entry; entry = entry->next) {
            if (strcmp(new->id.mon_id.mon_name, entry->name) != 0) {
                continue;
            }

            for (addr = entry->addresses; addr; addr = addr->next) {
                record_addr(new->id.mon_id.mon_name,
                    addr->family, &addr->ah);
            }
            break;
        }
        mutex_unlock(&name_addrlock);
    }

    SMHASH(new->id.mon_id.mon_name, hash);
    mutex_lock(&mon_table[hash].lock);
    monitor_q = mon_table[hash].sm_monhdp;

    /* If mon_table hash list is empty. */
    if (monitor_q == NULL) {
        if (debug)
            (void) printf("\nAdding to monitor_q hash %d\n", hash);
        new->nxt = new->prev = NULL;
        mon_table[hash].sm_monhdp = new;
        mutex_unlock(&mon_table[hash].lock);
        return;
    } else {
        found = 0;
        my_idp = &new->id.mon_id.my_id;
        while (monitor_q != NULL)  {
            /*
             * This list is searched sequentially for the
             * tuple (hostname, prog, vers, proc). The tuples
             * are inserted in the beginning of the monitor_q,
             * if the hostname is not already present in the list.
             * If the hostname is found in the list, the incoming
             * tuple is inserted just after all the tuples with the
             * same hostname. However, if the tuple matches exactly
             * with an entry in the list, space allocated for the
             * new entry is released and nothing is inserted in the
             * list.
             */

            if (str_cmp_unqual_hostname(
                monitor_q->id.mon_id.mon_name,
                new->id.mon_id.mon_name) == 0) {
                /* found */
                nl_idp = &monitor_q->id.mon_id.my_id;
                if ((str_cmp_unqual_hostname(my_idp->my_name,
                    nl_idp->my_name) == 0) &&
                    my_idp->my_prog == nl_idp->my_prog &&
                    my_idp->my_vers == nl_idp->my_vers &&
                    my_idp->my_proc == nl_idp->my_proc) {
                    /*
                     * already exists an identical one,
                     * release the space allocated for the
                     * mon_entry
                     */
                    free(new->id.mon_id.mon_name);
                    free(new->id.mon_id.my_id.my_name);
                    free(new);
                    mutex_unlock(&mon_table[hash].lock);
                    return;
                } else {
                    /*
                     * mark the last callback that is
                     * not matching; new is inserted
                     * after this
                     */
                    found = monitor_q;
                }
            } else if (found)
                break;
            monitor_q = monitor_q->nxt;
        }
        if (found) {
            /*
             * insert just after the entry having matching tuple.
             */
            new->nxt = found->nxt;
            new->prev = found;
            if (found->nxt != NULL)
                found->nxt->prev = new;
            found->nxt = new;
        } else {
            /*
             * not found, insert in front of list.
             */
            new->nxt = mon_table[hash].sm_monhdp;
            new->prev = (mon_entry *) NULL;
            if (new->nxt != (mon_entry *) NULL)
                new->nxt->prev = new;
            mon_table[hash].sm_monhdp = new;
        }
        mutex_unlock(&mon_table[hash].lock);
        return;
    }
}

/*
 * Deletes a specific monitor name or deletes all monitors with same id
 * in hash table.
 */
static void
delete_mon(char *mon_name, my_id *my_idp)
{
    unsigned int hash;

    if (mon_name != NULL) {
        record_name(mon_name, 0);
        SMHASH(mon_name, hash);
        mutex_lock(&mon_table[hash].lock);
        delete_onemon(mon_name, my_idp, &mon_table[hash].sm_monhdp);
        mutex_unlock(&mon_table[hash].lock);
    } else {
        for (hash = 0; hash < MAX_HASHSIZE; hash++) {
            mutex_lock(&mon_table[hash].lock);
            delete_onemon(mon_name, my_idp,
                &mon_table[hash].sm_monhdp);
            mutex_unlock(&mon_table[hash].lock);
        }
    }
}

/*
 * Deletes a monitor in list.
 * IF mon_name is NULL, delete all mon_names that have the same id,
 * else delete specific monitor.
 */
void
delete_onemon(char *mon_name, my_id *my_idp, mon_entry **monitor_q)
{

    mon_entry *next, *nl;
    my_id *nl_idp;

    next = *monitor_q;
    while ((nl = next) != NULL) {
        next = next->nxt;
        if (mon_name == NULL || (mon_name != NULL &&
            str_cmp_unqual_hostname(nl->id.mon_id.mon_name,
            mon_name) == 0)) {
            nl_idp = &nl->id.mon_id.my_id;
            if ((str_cmp_unqual_hostname(my_idp->my_name,
                nl_idp->my_name) == 0) &&
                my_idp->my_prog == nl_idp->my_prog &&
                my_idp->my_vers == nl_idp->my_vers &&
                my_idp->my_proc == nl_idp->my_proc) {
                /* found */
                if (debug)
                    (void) printf("delete_mon(%x): %s\n",
                        (int)nl, mon_name ?
                        mon_name : "<NULL>");
                /*
                 * Remove the monitor name from the
                 * record_q, if id matches.
                 */
                record_name(nl->id.mon_id.mon_name, 0);
                /* if nl is not the first entry on list */
                if (nl->prev != NULL)
                    nl->prev->nxt = nl->nxt;
                else {
                    *monitor_q = nl->nxt;
                }
                if (nl->nxt != NULL)
                    nl->nxt->prev = nl->prev;
                free(nl->id.mon_id.mon_name);
                free(nl_idp->my_name);
                free(nl);
            }
        } /* end of if mon */
    }

}
/*
 * Notify lockd of host specified by mon_name that the specified state
 * has changed.
 */
static void
send_notice(char *mon_name, int state)
{
    struct mon_entry *next;
    mon_entry *monitor_q;
    unsigned int hash;
    moninfo_t *minfop;
    mon *monp;

    SMHASH(mon_name, hash);
    mutex_lock(&mon_table[hash].lock);
    monitor_q = mon_table[hash].sm_monhdp;

    next = monitor_q;
    while (next != NULL) {
        if (hostname_eq(next->id.mon_id.mon_name, mon_name)) {
            monp = &next->id;
            /*
             * Prepare the minfop structure to pass to
             * thr_create(). This structure is a copy of
             * mon info and state.
             */
            if ((minfop =
                (moninfo_t *)xmalloc(sizeof (moninfo_t))) != NULL) {
                (void) memcpy(&minfop->id, monp, sizeof (mon));
                /* Allocate entry for mon_name */
                if ((minfop->id.mon_id.mon_name =
                    strdup(monp->mon_id.mon_name)) == 0) {
                    syslog(LOG_ERR, "statd: send_notice: "
                        "malloc error on mon %s (id=%d)\n",
                        monp->mon_id.mon_name,
                        *((int *)monp->priv));
                    free(minfop);
                    continue;
                }
                /* Allocate entry for my_name */
                if ((minfop->id.mon_id.my_id.my_name =
                    strdup(monp->mon_id.my_id.my_name)) == 0) {
                    syslog(LOG_ERR, "statd: send_notice: "
                        "malloc error on mon %s (id=%d)\n",
                        monp->mon_id.mon_name,
                        *((int *)monp->priv));
                    free(minfop->id.mon_id.mon_name);
                    free(minfop);
                    continue;
                }
                minfop->state = state;
                /*
                 * Create detached threads to process each host
                 * to notify.  If error, print out msg, free
                 * resources and continue.
                 */
                if (thr_create(NULL, NULL, thr_send_notice,
                    minfop, THR_DETACHED, NULL)) {
                    syslog(LOG_ERR, "statd: unable to "
                        "create thread to send_notice to "
                        "%s.\n", mon_name);
                    free(minfop->id.mon_id.mon_name);
                    free(minfop->id.mon_id.my_id.my_name);
                    free(minfop);
                    continue;
                }
            }
        }
        next = next->nxt;
    }
    mutex_unlock(&mon_table[hash].lock);
}

/*
 * Work thread created to do the actual statd_call_lockd
 */
static void *
thr_send_notice(void *arg)
{
    moninfo_t *minfop;

    minfop = (moninfo_t *)arg;
    if (statd_call_lockd(&minfop->id, minfop->state) == -1) {
        if (debug && minfop->id.mon_id.mon_name)
            (void) printf("problem with notifying %s failure, "
                "give up\n", minfop->id.mon_id.mon_name);
    } else {
        if (debug)
            (void) printf("send_notice: %s, %d notified.\n",
                minfop->id.mon_id.mon_name, minfop->state);
    }

    free(minfop->id.mon_id.mon_name);
    free(minfop->id.mon_id.my_id.my_name);
    free(minfop);

    thr_exit((void *) 0);
#ifdef lint
    /*NOTREACHED*/
    return ((void *)0);
#endif
}

/*
 * Contact lockd specified by monp.
 */
static int
statd_call_lockd(mon *monp, int state)
{
    enum clnt_stat clnt_stat;
    struct timeval tottimeout;
    struct sm_status stat;
    my_id *my_idp;
    char *mon_name;
    int i;
    int rc = 0;
    CLIENT *clnt;

    mon_name = monp->mon_id.mon_name;
    my_idp = &monp->mon_id.my_id;
    (void) memset(&stat, 0, sizeof (stat));
    stat.mon_name = mon_name;
    stat.state = state;
    for (i = 0; i < 16; i++) {
        stat.priv[i] = monp->priv[i];
    }
    if (debug)
        (void) printf("statd_call_lockd: %s state = %d\n",
            stat.mon_name, stat.state);

    tottimeout.tv_sec = SM_RPC_TIMEOUT;
    tottimeout.tv_usec = 0;

    clnt = create_client(my_idp->my_name, my_idp->my_prog, my_idp->my_vers,
        "ticotsord", &tottimeout);
    if (clnt == NULL) {
        return (-1);
    }

    clnt_stat = clnt_call(clnt, my_idp->my_proc, xdr_sm_status,
        (char *)&stat, xdr_void, NULL, tottimeout);
    if (debug) {
        (void) printf("clnt_stat=%s(%d)\n",
            clnt_sperrno(clnt_stat), clnt_stat);
    }
    if (clnt_stat != (int)RPC_SUCCESS) {
        syslog(LOG_WARNING,
            "statd: cannot talk to lockd at %s, %s(%d)\n",
            my_idp->my_name, clnt_sperrno(clnt_stat), clnt_stat);
        rc = -1;
    }

    clnt_destroy(clnt);
    return (rc);

}

/*
 * Client handle created.
 */
CLIENT *
create_client(char *host, int prognum, int versnum, char *netid,
    struct timeval *utimeout)
{
    int     fd;
    struct timeval  timeout;
    CLIENT      *client;
    struct t_info   tinfo;

    if (netid == NULL) {
        client = clnt_create_timed(host, prognum, versnum,
            "netpath", utimeout);
    } else {
        struct netconfig *nconf;

        nconf = getnetconfigent(netid);
        if (nconf == NULL) {
            return (NULL);
        }

        client = clnt_tp_create_timed(host, prognum, versnum, nconf,
            utimeout);

        freenetconfigent(nconf);
    }

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

    (void) CLNT_CONTROL(client, CLGET_FD, (caddr_t)&fd);
    if (t_getinfo(fd, &tinfo) != -1) {
        if (tinfo.servtype == T_CLTS) {
            /*
             * Set time outs for connectionless case
             */
            timeout.tv_usec = 0;
            timeout.tv_sec = SM_CLTS_TIMEOUT;
            (void) CLNT_CONTROL(client,
                CLSET_RETRY_TIMEOUT, (caddr_t)&timeout);
        }
    } else
        return (NULL);

    return (client);
}

/*
 * ONLY for debugging.
 * Debug messages which prints out the monitor table information.
 * If name is specified, just print out the hash list corresponding
 * to name, otherwise print out the entire monitor table.
 */
static void
pr_mon(char *name)
{
    mon_entry *nl;
    int hash;

    if (!debug)
        return;

    /* print all */
    if (name == NULL) {
        for (hash = 0; hash < MAX_HASHSIZE; hash++) {
            mutex_lock(&mon_table[hash].lock);
            nl = mon_table[hash].sm_monhdp;
            if (nl == NULL) {
                (void) printf(
                    "*****monitor_q = NULL hash %d\n", hash);
                mutex_unlock(&mon_table[hash].lock);
                continue;
            }
            (void) printf("*****monitor_q:\n ");
            while (nl != NULL) {
                (void) printf("%s:(%x), ",
                    nl->id.mon_id.mon_name, (int)nl);
                nl = nl->nxt;
            }
            mutex_unlock(&mon_table[hash].lock);
            (void) printf("\n");
        }
    } else { /* print one hash list */
        SMHASH(name, hash);
        mutex_lock(&mon_table[hash].lock);
        nl = mon_table[hash].sm_monhdp;
        if (nl == NULL) {
            (void) printf("*****monitor_q = NULL hash %d\n", hash);
        } else {
            (void) printf("*****monitor_q:\n ");
            while (nl != NULL) {
                (void) printf("%s:(%x), ",
                    nl->id.mon_id.mon_name, (int)nl);
                nl = nl->nxt;
            }
            (void) printf("\n");
        }
        mutex_unlock(&mon_table[hash].lock);
    }
}

/*
 * Only for debugging.
 * Dump the host name-to-address translation table passed in `name_addr'.
 */
static void
pr_name_addr(name_addr_entry_t *name_addr)
{
    name_addr_entry_t *entry;
    addr_entry_t *addr;
    struct in_addr ipv4_addr;
    char *ipv6_addr;
    char abuf[INET6_ADDRSTRLEN];

    assert(MUTEX_HELD(&name_addrlock));
    (void) printf("name-to-address translation table:\n");
    for (entry = name_addr; entry != NULL; entry = entry->next) {
        (void) printf("\t%s: ",
            (entry->name ? entry->name : "(null)"));
        for (addr = entry->addresses; addr; addr = addr->next) {
            switch (addr->family) {
            case AF_INET:
                ipv4_addr = *(struct in_addr *)addr->ah.n_bytes;
                (void) printf(" %s (fam %d)",
                    inet_ntoa(ipv4_addr), addr->family);
                break;
            case AF_INET6:
                ipv6_addr = (char *)addr->ah.n_bytes;
                (void) printf(" %s (fam %d)",
                    inet_ntop(addr->family, ipv6_addr, abuf,
                    sizeof (abuf)), addr->family);
                break;
            default:
                return;
            }
        }
        printf("\n");
    }
}

/*
 * First, try to compare the hostnames as strings.  If the hostnames does not
 * match we might deal with the hostname aliases.  In this case two different
 * aliases for the same machine don't match each other when using strcmp.  To
 * deal with this, the hostnames must be translated into some sort of universal
 * identifier.  These identifiers can be compared.  Universal network addresses
 * are currently used for this identifier because it is general and easy to do.
 * Other schemes are possible and this routine could be converted if required.
 *
 * If it can't find an address for some reason, 0 is returned.
 */
static int
hostname_eq(char *host1, char *host2)
{
    char *sysid1;
    char *sysid2;
    int rv;

    /* Compare hostnames as strings */
    if (host1 != NULL && host2 != NULL && strcmp(host1, host2) == 0)
        return (1);

    /* Try harder if hostnames do not match */
    sysid1 = get_system_id(host1);
    sysid2 = get_system_id(host2);
    if ((sysid1 == NULL) || (sysid2 == NULL))
        rv = 0;
    else
        rv = (strcmp(sysid1, sysid2) == 0);
    free(sysid1);
    free(sysid2);
    return (rv);
}

/*
 * Convert a hostname character string into its network address.
 * A network address is found by searching through all the entries
 * in /etc/netconfig and doing a netdir_getbyname() for each inet
 * entry found.  The netbuf structure returned is converted into
 * a universal address format.
 *
 * If a NULL hostname is given, then the name of the current host
 * is used.  If the hostname doesn't map to an address, a NULL
 * pointer is returned.
 *
 * N.B. the character string returned is allocated in taddr2uaddr()
 * and should be freed by the caller using free().
 */
static char *
get_system_id(char *hostname)
{
    void *hp;
    struct netconfig *ncp;
    struct nd_hostserv service;
    struct nd_addrlist *addrs;
    char *uaddr;
    int rv;

    if (hostname == NULL)
        service.h_host = HOST_SELF;
    else
        service.h_host = hostname;
    service.h_serv = NULL;
    hp = setnetconfig();
    if (hp == (void *) NULL) {
        return (NULL);
    }
    while ((ncp = getnetconfig(hp)) != NULL) {
        if ((strcmp(ncp->nc_protofmly, NC_INET) == 0) ||
            (strcmp(ncp->nc_protofmly, NC_INET6) == 0)) {
            addrs = NULL;
            rv = netdir_getbyname(ncp, &service, &addrs);
            if (rv != 0) {
                continue;
            }
            if (addrs) {
                uaddr = taddr2uaddr(ncp, addrs->n_addrs);
                netdir_free(addrs, ND_ADDRLIST);
                endnetconfig(hp);
                return (uaddr);
            }
        }
        else
            continue;
    }
    endnetconfig(hp);
    return (NULL);
}

void
merge_hosts(void)
{
    struct lifconf *lifc = NULL;
    int sock = -1;
    struct lifreq *lifrp;
    struct lifreq lifr;
    int n;
    struct sockaddr_in *sin;
    struct sockaddr_in6 *sin6;
    struct sockaddr_storage *sa;
    int af;
    struct hostent *phost;
    char *addr;
    size_t alen;
    int errnum;

    /*
     * This function will enumerate all the interfaces for
     * this platform, then get the hostent for each i/f.
     * With the hostent structure, we can get all of the
     * aliases for the i/f. Then we'll merge all the aliases
     * with the existing host_name[] list to come up with
     * all of the known names for each interface. This solves
     * the problem of a multi-homed host not knowing which
     * name to publish when statd is started. All the aliases
     * will be stored in the array, host_name.
     *
     * NOTE: Even though we will use all of the aliases we
     * can get from the i/f hostent, the receiving statd
     * will still need to handle aliases with hostname_eq.
     * This is because the sender's aliases may not match
     * those of the receiver.
     */
    lifc = getmyaddrs();
    if (lifc == NULL) {
        goto finish;
    }
    lifrp = lifc->lifc_req;
    for (n = lifc->lifc_len / sizeof (struct lifreq); n > 0; n--, lifrp++) {

        (void) strncpy(lifr.lifr_name, lifrp->lifr_name,
            sizeof (lifr.lifr_name));

        af = lifrp->lifr_addr.ss_family;
        sock = socket(af, SOCK_DGRAM, 0);
        if (sock == -1) {
            syslog(LOG_ERR, "statd: socket failed\n");
            goto finish;
        }

        /* If it's the loopback interface, ignore */
        if (ioctl(sock, SIOCGLIFFLAGS, (caddr_t)&lifr) < 0) {
            syslog(LOG_ERR,
                "statd: SIOCGLIFFLAGS failed, error: %m\n");
            goto finish;
        }
        if (lifr.lifr_flags & IFF_LOOPBACK)
            continue;

        if (ioctl(sock, SIOCGLIFADDR, (caddr_t)&lifr) < 0) {
            syslog(LOG_ERR,
                "statd: SIOCGLIFADDR failed, error: %m\n");
            goto finish;
        }
        sa = (struct sockaddr_storage *)&(lifr.lifr_addr);

        if (sa->ss_family == AF_INET) {
            sin = (struct sockaddr_in *)&lifr.lifr_addr;
            addr = (char *)(&sin->sin_addr);
            alen = sizeof (struct in_addr);
        } else if (sa->ss_family == AF_INET6) {
            sin6 = (struct sockaddr_in6 *)&lifr.lifr_addr;
            addr = (char *)(&sin6->sin6_addr);
            alen = sizeof (struct in6_addr);
        } else {
            syslog(LOG_WARNING,
                "unexpected address family (%d)",
                sa->ss_family);
            continue;
        }

        phost = getipnodebyaddr(addr, alen, sa->ss_family, &errnum);

        if (phost)
            add_aliases(phost);
    }
    /*
     * Now, just in case we didn't get them all byaddr,
     * let's look by name.
     */
    phost = getipnodebyname(hostname, AF_INET6, AI_ALL, &errnum);

    if (phost)
        add_aliases(phost);

finish:
    if (sock != -1)
        (void) close(sock);
    if (lifc) {
        free(lifc->lifc_buf);
        free(lifc);
    }
}

/*
 * add_aliases traverses a hostent alias list, compares
 * the aliases to the contents of host_name, and if an
 * alias is not already present, adds it to host_name[].
 */

static void
add_aliases(struct hostent *phost)
{
    char **aliases;

    if (!in_host_array(phost->h_name)) {
        add_to_host_array(phost->h_name);
    }

    if (phost->h_aliases == NULL)
        return;         /* no aliases to register */

    for (aliases = phost->h_aliases; *aliases != NULL; aliases++) {
        if (!in_host_array(*aliases)) {
            add_to_host_array(*aliases);
        }
    }
}

/*
 * in_host_array checks if the given hostname exists in the host_name
 * array. Returns 0 if the host doesn't exist, and 1 if it does exist
 */
static int
in_host_array(char *host)
{
    int i;

    if (debug)
        (void) printf("%s ", host);

    if ((strcmp(hostname, host) == 0) || (strcmp(LOGHOST, host) == 0))
        return (1);

    for (i = 0; i < addrix; i++) {
        if (strcmp(host_name[i], host) == 0)
            return (1);
    }

    return (0);
}

/*
 * add_to_host_array adds a hostname to the host_name array. But if
 * the array is already full, then it first reallocates the array with
 * HOST_NAME_INCR extra elements. If the realloc fails, then it does
 * nothing and leaves host_name the way it was previous to the call.
 */
static void
add_to_host_array(char *host) {

    void *new_block = NULL;

    /* Make sure we don't overrun host_name. */
    if (addrix >= host_name_count) {
        host_name_count += HOST_NAME_INCR;
        new_block = realloc((void *)host_name,
                    host_name_count*sizeof (char *));
        if (new_block != NULL)
            host_name = new_block;
        else {
            host_name_count -= HOST_NAME_INCR;
            return;
        }
    }

    if ((host_name[addrix] = strdup(host)) != NULL)
        addrix++;
}

/*
 * Compares the unqualified hostnames for hosts. Returns 0 if the
 * names match, and 1 if the names fail to match.
 */
int
str_cmp_unqual_hostname(char *rawname1, char *rawname2)
{
    size_t unq_len1, unq_len2;
    char *domain;

    if (debug) {
        (void) printf("str_cmp_unqual: rawname1= %s, rawname2= %s\n",
            rawname1, rawname2);
    }

    unq_len1 = strcspn(rawname1, ".");
    unq_len2 = strcspn(rawname2, ".");
    domain = strchr(rawname1, '.');
    if (domain != NULL) {
        if ((strncmp(rawname1, SM_ADDR_IPV4, unq_len1) == 0) ||
            (strncmp(rawname1, SM_ADDR_IPV6, unq_len1) == 0))
        return (1);
    }

    if ((unq_len1 == unq_len2) &&
        (strncmp(rawname1, rawname2, unq_len1) == 0)) {
        return (0);
    }

    return (1);
}

/*
 * Compares <family>.<address-specifier> ASCII names for hosts.  Returns
 * 0 if the addresses match, and 1 if the addresses fail to match.
 * If the args are indeed specifiers, they should look like this:
 *
 *  ipv4.192.9.200.1 or ipv6.::C009:C801
 */
int
str_cmp_address_specifier(char *specifier1, char *specifier2)
{
    size_t unq_len1, unq_len2;
    char *rawaddr1, *rawaddr2;
    int af1, af2, len;

    if (debug) {
        (void) printf("str_cmp_addr: specifier1= %s, specifier2= %s\n",
            specifier1, specifier2);
    }

    /*
     * Verify that:
     *  1. The family tokens match;
     *  2. The IP addresses following the `.' are legal; and
     *  3. These addresses match.
     */
    unq_len1 = strcspn(specifier1, ".");
    unq_len2 = strcspn(specifier2, ".");
    rawaddr1 = strchr(specifier1, '.');
    rawaddr2 = strchr(specifier2, '.');

    if (strncmp(specifier1, SM_ADDR_IPV4, unq_len1) == 0) {
        af1 = AF_INET;
        len = 4;
    } else if (strncmp(specifier1, SM_ADDR_IPV6, unq_len1) == 0) {
        af1 = AF_INET6;
        len = 16;
    }
    else
        return (1);

    if (strncmp(specifier2, SM_ADDR_IPV4, unq_len2) == 0)
        af2 = AF_INET;
    else if (strncmp(specifier2, SM_ADDR_IPV6, unq_len2) == 0)
        af2 = AF_INET6;
    else
        return (1);

    if (af1 != af2)
        return (1);

    if (rawaddr1 != NULL && rawaddr2 != NULL) {
        char dst1[16];
        char dst2[16];
        ++rawaddr1;
        ++rawaddr2;

        if (inet_pton(af1, rawaddr1, dst1) == 1 &&
            inet_pton(af2, rawaddr1, dst2) == 1 &&
            memcmp(dst1, dst2, len) == 0) {
            return (0);
        }
    }
    return (1);
}

/*
 * Add IP address strings to the host_name list.
 */
void
merge_ips(void)
{
    struct ifaddrs *ifap, *cifap;
    int error;

    error = getifaddrs(&ifap);
    if (error) {
        syslog(LOG_WARNING, "getifaddrs error: '%s'",
            strerror(errno));
        return;
    }

    for (cifap = ifap; cifap != NULL; cifap = cifap->ifa_next) {
        struct sockaddr *sa = cifap->ifa_addr;
        char addr_str[INET6_ADDRSTRLEN];
        void *addr = NULL;

        switch (sa->sa_family) {
        case AF_INET: {
            struct sockaddr_in *sin = (struct sockaddr_in *)sa;

            /* Skip loopback addresses. */
            if (sin->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) {
                continue;
            }

            addr = &sin->sin_addr;
            break;
        }

        case AF_INET6: {
            struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;

            /* Skip loopback addresses. */
            if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) {
                continue;
            }

            addr = &sin6->sin6_addr;
            break;
        }

        default:
            syslog(LOG_WARNING, "Unknown address family %d for "
                "interface %s", sa->sa_family, cifap->ifa_name);
            continue;
        }

        if (inet_ntop(sa->sa_family, addr, addr_str, sizeof (addr_str))
            == NULL) {
            syslog(LOG_WARNING, "Failed to convert address into "
                "string representation for interface '%s' "
                "address family %d", cifap->ifa_name,
                sa->sa_family);
            continue;
        }

        if (!in_host_array(addr_str)) {
            add_to_host_array(addr_str);
        }
    }

    freeifaddrs(ifap);
}