cmd/rpcbind/check_bound.c

	check_bound.c revision 8f6d9dae92449b59bdafcb7777bc32f1b2726e48
/*
 * 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 2002 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
 */

/* Copyright (c) 1983, 1984, 1985, 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.
 */

/*
 * check_bound.c
 * Checks to see whether the program is still bound to the
 * claimed address and returns the univeral merged address
 *
 */

#include <stdio.h>
#include <rpc/rpc.h>
#include <netconfig.h>
#include <netdir.h>
#include <sys/syslog.h>
#include <stdlib.h>
#include "rpcbind.h"
#include <string.h>
/* the following just to get my address */
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <thread.h>
#include <synch.h>
#include <syslog.h>

struct fdlist {
    int fd;
    mutex_t fd_lock;    /* protects fd */
    struct netconfig *nconf;
    struct fdlist *next;
    int check_binding;
};

static struct fdlist *fdhead;   /* Link list of the check fd's */
static struct fdlist *fdtail;
static char *nullstring = "";

/*
 * Returns 1 if the given address is bound for the given addr & transport
 * For all error cases, we assume that the address is bound
 * Returns 0 for success.
 *
 * fdl: My FD list
 * uaddr: the universal address
 */
static bool_t
check_bound(struct fdlist *fdl, char *uaddr)
{
    int fd;
    struct netbuf *na;
    struct t_bind taddr, *baddr;
    int ans;

    if (fdl->check_binding == FALSE)
        return (TRUE);

    na = uaddr2taddr(fdl->nconf, uaddr);
    if (!na)
        return (TRUE); /* punt, should never happen */

    taddr.addr = *na;
    taddr.qlen = 1;
    (void) mutex_lock(&fdl->fd_lock);
    fd = fdl->fd;
    baddr = (struct t_bind *)t_alloc(fd, T_BIND, T_ADDR);
    if (baddr == NULL) {
        (void) mutex_unlock(&fdl->fd_lock);
        netdir_free((char *)na, ND_ADDR);
        return (TRUE);
    }
    if (t_bind(fd, &taddr, baddr) != 0) {
        (void) mutex_unlock(&fdl->fd_lock);
        netdir_free((char *)na, ND_ADDR);
        (void) t_free((char *)baddr, T_BIND);
        return (TRUE);
    }
    if (t_unbind(fd) != 0) {
        /* Bad fd. Purge this fd */
        (void) t_close(fd);
        fdl->fd = t_open(fdl->nconf->nc_device, O_RDWR, NULL);
        if (fdl->fd == -1)
            fdl->check_binding = FALSE;
    }
    (void) mutex_unlock(&fdl->fd_lock);
    ans = memcmp(taddr.addr.buf, baddr->addr.buf, baddr->addr.len);
    netdir_free((char *)na, ND_ADDR);
    (void) t_free((char *)baddr, T_BIND);
    return (ans == 0 ? FALSE : TRUE);
}

/*
 * Keep open one more file descriptor for this transport, which
 * will be used to determine whether the given service is up
 * or not by trying to bind to the registered address.
 * We are ignoring errors here. It trashes taddr and baddr;
 * but that perhaps should not matter.
 *
 * We check for the following conditions:
 *  1. Is it possible for t_bind to fail in the case where
 *      we bind to an already bound address and have any
 *      other error number besides TNOADDR.
 *  2. If an address is specified in bind addr, can I bind to
 *      the same address.
 *  3. If NULL is specified in bind addr, can I bind to the
 *      address to which the fd finally got bound.
 */
int
add_bndlist(struct netconfig *nconf, struct t_bind *taddr, struct t_bind *baddr)
{
    int fd;
    struct fdlist *fdl;
    struct netconfig *newnconf;
    struct t_info tinfo;
    struct t_bind tmpaddr;

    newnconf = getnetconfigent(nconf->nc_netid);
    if (newnconf == NULL)
        return (-1);
    fdl = (struct fdlist *)malloc((uint_t)sizeof (struct fdlist));
    if (fdl == NULL) {
        freenetconfigent(newnconf);
        syslog(LOG_ERR, "no memory!");
        return (-1);
    }
    (void) mutex_init(&fdl->fd_lock, USYNC_THREAD, NULL);
    fdl->nconf = newnconf;
    fdl->next = NULL;
    if (fdhead == NULL) {
        fdhead = fdl;
        fdtail = fdl;
    } else {
        fdtail->next = fdl;
        fdtail = fdl;
    }
    fdl->check_binding = FALSE;
    if ((fdl->fd = t_open(nconf->nc_device, O_RDWR, &tinfo)) < 0) {
        /*
         * Note that we haven't dequeued this entry nor have we freed
         * the netconfig structure.
         */
        if (debugging) {
            fprintf(stderr,
                "%s: add_bndlist cannot open connection: %s",
                nconf->nc_netid, t_errlist[t_errno]);
        }
        return (-1);
    }

    /* Set the qlen only for cots transports */
    switch (tinfo.servtype) {
    case T_COTS:
    case T_COTS_ORD:
        taddr->qlen = 1;
        break;
    case T_CLTS:
        taddr->qlen = 0;
        break;
    default:
        goto error;
    }

    if (t_bind(fdl->fd, taddr, baddr) != 0) {
        if (t_errno == TNOADDR) {
            fdl->check_binding = TRUE;
            return (0); /* All is fine */
        }
        /* Perhaps condition #1 */
        if (debugging) {
            fprintf(stderr, "%s: add_bndlist cannot bind (1): %s",
                nconf->nc_netid, t_errlist[t_errno]);
        }
        goto not_bound;
    }

    /* Condition #2 */
    if (!memcmp(taddr->addr.buf, baddr->addr.buf,
        (int)baddr->addr.len)) {
        goto not_bound;
    }

    /* Condition #3 */
    t_unbind(fdl->fd);
    /* Set the qlen only for cots transports */
    switch (tinfo.servtype) {
    case T_COTS:
    case T_COTS_ORD:
        tmpaddr.qlen = 1;
        break;
    case T_CLTS:
        tmpaddr.qlen = 0;
        break;
    default:
        goto error;
    }
    tmpaddr.addr.len = tmpaddr.addr.maxlen = 0;
    tmpaddr.addr.buf = NULL;
    if (t_bind(fdl->fd, &tmpaddr, taddr) != 0) {
        if (debugging) {
            fprintf(stderr, "%s: add_bndlist cannot bind (2): %s",
                nconf->nc_netid, t_errlist[t_errno]);
        }
        goto error;
    }
    /* Now fdl->fd is bound to a transport chosen address */
    if ((fd = t_open(nconf->nc_device, O_RDWR, &tinfo)) < 0) {
        if (debugging) {
            fprintf(stderr,
                "%s: add_bndlist cannot open connection: %s",
                nconf->nc_netid, t_errlist[t_errno]);
        }
        goto error;
    }
    if (t_bind(fd, taddr, baddr) != 0) {
        if (t_errno == TNOADDR) {
            /*
             * This transport is schizo.  Previously it handled a
             * request to bind to an already bound transport by
             * returning a different bind address, and now it's
             * returning a TNOADDR for essentially the same
             * request.  The spec may allow this behavior, so
             * we'll just assume we can't do bind checking with
             * this transport.
             */
            t_close(fd);
            goto not_bound;
        }
        if (debugging) {
            fprintf(stderr, "%s: add_bndlist cannot bind (3): %s",
                nconf->nc_netid, t_errlist[t_errno]);
        }
        t_close(fd);
        goto error;
    }
    t_close(fd);
    if (!memcmp(taddr->addr.buf, baddr->addr.buf,
        (int)baddr->addr.len)) {
        switch (tinfo.servtype) {
        case T_COTS:
        case T_COTS_ORD:
            if (baddr->qlen == 1) {
                goto not_bound;
            }
            break;
        case T_CLTS:
            goto not_bound;
        default:
            goto error;
        }
    }

    t_unbind(fdl->fd);
    fdl->check_binding = TRUE;
    return (0);

not_bound:
    t_close(fdl->fd);
    fdl->fd = -1;
    return (1);

error:
    t_close(fdl->fd);
    fdl->fd = -1;
    return (-1);
}

bool_t
is_bound(char *netid, char *uaddr)
{
    struct fdlist *fdl;

    for (fdl = fdhead; fdl; fdl = fdl->next)
        if (strcmp(fdl->nconf->nc_netid, netid) == 0)
            break;
    if (fdl == NULL)
        return (TRUE);
    return (check_bound(fdl, uaddr));
}

/* Return pointer to port string in the universal address */
#define UADDR_PRT_INDX(UADDR, PORT) { \
    PORT = strrchr(UADDR, '.'); \
    while (*--PORT != '.'); }
/*
 * Returns NULL if there was some system error.
 * Returns "" if the address was not bound, i.e the server crashed.
 * Returns the merged address otherwise.
 */
char *
mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
{
    struct fdlist *fdl;
    struct nd_mergearg ma;
    int stat;

    for (fdl = fdhead; fdl; fdl = fdl->next)
        if (strcmp(fdl->nconf->nc_netid, netid) == 0)
            break;
    if (fdl == NULL)
        return (NULL);
    if (check_bound(fdl, uaddr) == FALSE)
        /* that server died */
        return (nullstring);
    /*
     * If saddr is not NULL, the remote client may have included the
     * address by which it contacted us.  Use that for the "client" uaddr,
     * otherwise use the info from the SVCXPRT.
     */
    if (saddr != NULL) {
        ma.c_uaddr = saddr;
    } else {

        /* retrieve the client's address */
        ma.c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
        if (ma.c_uaddr == NULL) {
            syslog(LOG_ERR, "taddr2uaddr failed for %s: %s",
                fdl->nconf->nc_netid, netdir_sperror());
            return (NULL);
        }

    }

    /* Not an INET address? */
    if ((strcmp(fdl->nconf->nc_protofmly, NC_INET) != 0) &&
        (strcmp(fdl->nconf->nc_protofmly, NC_INET6) != 0)) {
        ma.s_uaddr = uaddr;
        stat = netdir_options(fdl->nconf, ND_MERGEADDR, 0, (char *)&ma);
    }
    /* Inet address, but no xp_ltaddr */
    else if ((ma.s_uaddr = taddr2uaddr(fdl->nconf,
        &(xprt)->xp_ltaddr)) == NULL) {
        ma.s_uaddr = uaddr;
        stat = netdir_options(fdl->nconf, ND_MERGEADDR, 0, (char *)&ma);
    } else {
        /*
         * (xprt)->xp_ltaddr contains portmap's port address.
         * Overwrite this with actual application's port address
         * before returning to the caller.
         */
        char *s_uport, *uport;

        /* Get the INET/INET6 address part from ma.s_uaddr */
        UADDR_PRT_INDX(ma.s_uaddr, s_uport);
        *s_uport = '\0';

        /* Get the port info from uaddr */
        UADDR_PRT_INDX(uaddr, uport);

        ma.m_uaddr = malloc(strlen(ma.s_uaddr) + strlen(uport) + 1);
        if (ma.m_uaddr == NULL) {
            syslog(LOG_ERR, "mergeaddr: no memory!");
            free(ma.s_uaddr);
            if (saddr == NULL)
                free(ma.c_uaddr);
            return (NULL);
        }

        /* Copy IP address into the Universal address holder */
        strcpy(ma.m_uaddr, ma.s_uaddr);
        /* Append port info to the Universal address holder */
        strcat(ma.m_uaddr, uport);
        free(ma.s_uaddr);
        stat = 0;
    }
    if (saddr == NULL) {
        free(ma.c_uaddr);
    }
    if (stat) {
        syslog(LOG_ERR, "netdir_merge failed for %s: %s",
            fdl->nconf->nc_netid, netdir_sperror());
        return (NULL);
    }

    return (ma.m_uaddr);
}

/*
 * Returns a netconf structure from its internal list.  This
 * structure should not be freed.
 */
struct netconfig *
rpcbind_get_conf(char *netid)
{
    struct fdlist *fdl;

    for (fdl = fdhead; fdl; fdl = fdl->next)
        if (strcmp(fdl->nconf->nc_netid, netid) == 0)
            break;
    if (fdl == NULL)
        return (NULL);
    return (fdl->nconf);
}