libmlsvc/common/mlsvc_client.c

	mlsvc_client.c revision 9fb67ea305c66b6a297583b9b0db6796b0dfe497
/*
 * 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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Client NDR RPC interface.
 */

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/tzfile.h>
#include <time.h>
#include <strings.h>
#include <assert.h>
#include <thread.h>
#include <unistd.h>
#include <syslog.h>
#include <synch.h>
#include <smbsrv/libsmb.h>
#include <smbsrv/libsmbrdr.h>
#include <smbsrv/libmlrpc.h>
#include <smbsrv/libmlsvc.h>
#include <smbsrv/ndl/srvsvc.ndl>
#include <mlsvc.h>

/*
 * Server info cache entry expiration in seconds.
 */
#define NDR_SVINFO_TIMEOUT  1800

typedef struct ndr_svinfo {
    list_node_t     svi_lnd;
    time_t          svi_tcached;
    char            svi_server[MAXNAMELEN];
    char            svi_domain[MAXNAMELEN];
    srvsvc_server_info_t    svi_svinfo;
} ndr_svinfo_t;

typedef struct ndr_svlist {
    list_t      svl_list;
    mutex_t     svl_mtx;
    boolean_t   svl_init;
} ndr_svlist_t;

static ndr_svlist_t ndr_svlist;

static int ndr_xa_init(ndr_client_t *, ndr_xa_t *);
static int ndr_xa_exchange(ndr_client_t *, ndr_xa_t *);
static int ndr_xa_read(ndr_client_t *, ndr_xa_t *);
static void ndr_xa_preserve(ndr_client_t *, ndr_xa_t *);
static void ndr_xa_destruct(ndr_client_t *, ndr_xa_t *);
static void ndr_xa_release(ndr_client_t *);

static int ndr_svinfo_lookup(char *, char *, srvsvc_server_info_t *);
static boolean_t ndr_svinfo_match(const char *, const char *, const
    ndr_svinfo_t *);
static boolean_t ndr_svinfo_expired(ndr_svinfo_t *);

/*
 * Initialize the RPC client interface: create the server info cache.
 */
void
ndr_rpc_init(void)
{
    (void) mutex_lock(&ndr_svlist.svl_mtx);

    if (!ndr_svlist.svl_init) {
        list_create(&ndr_svlist.svl_list, sizeof (ndr_svinfo_t),
            offsetof(ndr_svinfo_t, svi_lnd));
        ndr_svlist.svl_init = B_TRUE;
    }

    (void) mutex_unlock(&ndr_svlist.svl_mtx);
}

/*
 * Terminate the RPC client interface: flush and destroy the server info
 * cache.
 */
void
ndr_rpc_fini(void)
{
    ndr_svinfo_t *svi;

    (void) mutex_lock(&ndr_svlist.svl_mtx);

    if (ndr_svlist.svl_init) {
        while ((svi = list_head(&ndr_svlist.svl_list)) != NULL) {
            list_remove(&ndr_svlist.svl_list, svi);
            free(svi->svi_svinfo.sv_name);
            free(svi->svi_svinfo.sv_comment);
            free(svi);
        }

        list_destroy(&ndr_svlist.svl_list);
        ndr_svlist.svl_init = B_FALSE;
    }

    (void) mutex_unlock(&ndr_svlist.svl_mtx);
}

/*
 * This call must be made to initialize an RPC client structure and bind
 * to the remote service before any RPCs can be exchanged with that service.
 *
 * The mlsvc_handle_t is a wrapper that is used to associate an RPC handle
 * with the client context for an instance of the interface.  The handle
 * is zeroed to ensure that it doesn't look like a valid handle -
 * handle content is provided by the remove service.
 *
 * The client points to this top-level handle so that we know when to
 * unbind and teardown the connection.  As each handle is initialized it
 * will inherit a reference to the client context.
 */
int
ndr_rpc_bind(mlsvc_handle_t *handle, char *server, char *domain,
    char *username, const char *service)
{
    ndr_client_t        *clnt;
    ndr_service_t       *svc;
    srvsvc_server_info_t    svinfo;
    int         fid;
    int         rc;

    if (handle == NULL || server == NULL ||
        domain == NULL || username == NULL)
        return (-1);

    if ((svc = ndr_svc_lookup_name(service)) == NULL)
        return (-1);

    /*
     * Set the default based on the assumption that most
     * servers will be Windows 2000 or later.
     * Don't lookup the svinfo if this is a SRVSVC request
     * because the SRVSVC is used to get the server info.
     * None of the SRVSVC calls depend on the server info.
     */
    bzero(&svinfo, sizeof (srvsvc_server_info_t));
    svinfo.sv_platform_id = SV_PLATFORM_ID_NT;
    svinfo.sv_version_major = 5;
    svinfo.sv_version_minor = 0;
    svinfo.sv_type = SV_TYPE_DEFAULT;
    svinfo.sv_os = NATIVE_OS_WIN2000;

    if (strcasecmp(service, "SRVSVC") != 0)
        (void) ndr_svinfo_lookup(server, domain, &svinfo);

    if ((clnt = malloc(sizeof (ndr_client_t))) == NULL)
        return (-1);

    fid = smbrdr_open_pipe(server, domain, username, svc->endpoint);
    if (fid < 0) {
        free(clnt);
        return (-1);
    }

    bzero(clnt, sizeof (ndr_client_t));
    clnt->handle = &handle->handle;
    clnt->fid = fid;

    ndr_svc_binding_pool_init(&clnt->binding_list,
        clnt->binding_pool, NDR_N_BINDING_POOL);

    clnt->xa_init = ndr_xa_init;
    clnt->xa_exchange = ndr_xa_exchange;
    clnt->xa_read = ndr_xa_read;
    clnt->xa_preserve = ndr_xa_preserve;
    clnt->xa_destruct = ndr_xa_destruct;
    clnt->xa_release = ndr_xa_release;

    bzero(&handle->handle, sizeof (ndr_hdid_t));
    handle->clnt = clnt;
    bcopy(&svinfo, &handle->svinfo, sizeof (srvsvc_server_info_t));

    if (ndr_rpc_get_heap(handle) == NULL) {
        free(clnt);
        return (-1);
    }

    rc = ndr_clnt_bind(clnt, service, &clnt->binding);
    if (NDR_DRC_IS_FAULT(rc)) {
        (void) smbrdr_close_pipe(fid);
        ndr_heap_destroy(clnt->heap);
        free(clnt);
        handle->clnt = NULL;
        return (-1);
    }

    return (0);
}

/*
 * Unbind and close the pipe to an RPC service.
 *
 * If the heap has been preserved we need to go through an xa release.
 * The heap is preserved during an RPC call because that's where data
 * returned from the server is stored.
 *
 * Otherwise we destroy the heap directly.
 */
void
ndr_rpc_unbind(mlsvc_handle_t *handle)
{
    ndr_client_t *clnt = handle->clnt;

    if (clnt->heap_preserved)
        ndr_clnt_free_heap(clnt);
    else
        ndr_heap_destroy(clnt->heap);

    (void) smbrdr_close_pipe(clnt->fid);
    free(handle->clnt);
    bzero(handle, sizeof (mlsvc_handle_t));
}

/*
 * Call the RPC function identified by opnum.  The remote service is
 * identified by the handle, which should have been initialized by
 * ndr_rpc_bind.
 *
 * If the RPC call is successful (returns 0), the caller must call
 * ndr_rpc_release to release the heap.  Otherwise, we release the
 * heap here.
 */
int
ndr_rpc_call(mlsvc_handle_t *handle, int opnum, void *params)
{
    ndr_client_t *clnt = handle->clnt;
    int rc;

    if (ndr_rpc_get_heap(handle) == NULL)
        return (-1);

    rc = ndr_clnt_call(clnt->binding, opnum, params);

    /*
     * Always clear the nonull flag to ensure
     * it is not applied to subsequent calls.
     */
    clnt->nonull = B_FALSE;

    if (NDR_DRC_IS_FAULT(rc)) {
        ndr_rpc_release(handle);
        return (-1);
    }

    return (0);
}

/*
 * Outgoing strings should not be null terminated.
 */
void
ndr_rpc_set_nonull(mlsvc_handle_t *handle)
{
    handle->clnt->nonull = B_TRUE;
}

/*
 * Return a reference to the server info.
 */
const srvsvc_server_info_t *
ndr_rpc_server_info(mlsvc_handle_t *handle)
{
    return (&handle->svinfo);
}

/*
 * Return the RPC server OS level.
 */
uint32_t
ndr_rpc_server_os(mlsvc_handle_t *handle)
{
    return (handle->svinfo.sv_os);
}

/*
 * Get the session key from a bound RPC client handle.
 *
 * The key returned is the 16-byte "user session key"
 * established by the underlying authentication protocol
 * (either Kerberos or NTLM).  This key is needed for
 * SAM RPC calls such as SamrSetInformationUser, etc.
 * See [MS-SAMR] sections: 2.2.3.3, 2.2.7.21, 2.2.7.25.
 *
 * Returns zero (success) or an errno.
 */
int
ndr_rpc_get_ssnkey(mlsvc_handle_t *handle,
    unsigned char *ssn_key, size_t len)
{
    ndr_client_t *clnt = handle->clnt;
    int rc;

    if (clnt == NULL)
        return (EINVAL);

    rc = smbrdr_get_ssnkey(clnt->fid, ssn_key, len);
    return (rc);
}

void *
ndr_rpc_malloc(mlsvc_handle_t *handle, size_t size)
{
    ndr_heap_t *heap;

    if ((heap = ndr_rpc_get_heap(handle)) == NULL)
        return (NULL);

    return (ndr_heap_malloc(heap, size));
}

ndr_heap_t *
ndr_rpc_get_heap(mlsvc_handle_t *handle)
{
    ndr_client_t *clnt = handle->clnt;

    if (clnt->heap == NULL)
        clnt->heap = ndr_heap_create();

    return (clnt->heap);
}

/*
 * Must be called by RPC clients to free the heap after a successful RPC
 * call, i.e. ndr_rpc_call returned 0.  The caller should take a copy
 * of any data returned by the RPC prior to calling this function because
 * returned data is in the heap.
 */
void
ndr_rpc_release(mlsvc_handle_t *handle)
{
    ndr_client_t *clnt = handle->clnt;

    if (clnt->heap_preserved)
        ndr_clnt_free_heap(clnt);
    else
        ndr_heap_destroy(clnt->heap);

    clnt->heap = NULL;
}

/*
 * Returns true if the handle is null.
 * Otherwise returns false.
 */
boolean_t
ndr_is_null_handle(mlsvc_handle_t *handle)
{
    static ndr_hdid_t zero_handle;

    if (handle == NULL || handle->clnt == NULL)
        return (B_TRUE);

    if (!memcmp(&handle->handle, &zero_handle, sizeof (ndr_hdid_t)))
        return (B_TRUE);

    return (B_FALSE);
}

/*
 * Returns true if the handle is the top level bind handle.
 * Otherwise returns false.
 */
boolean_t
ndr_is_bind_handle(mlsvc_handle_t *handle)
{
    return (handle->clnt->handle == &handle->handle);
}

/*
 * Pass the client reference from parent to child.
 */
void
ndr_inherit_handle(mlsvc_handle_t *child, mlsvc_handle_t *parent)
{
    child->clnt = parent->clnt;
    bcopy(&parent->svinfo, &child->svinfo, sizeof (srvsvc_server_info_t));
}

void
ndr_rpc_status(mlsvc_handle_t *handle, int opnum, DWORD status)
{
    ndr_service_t *svc;
    char *name = "NDR RPC";
    char *s = "unknown";

    if (status == 0)
        s = "success";
    else if (NT_SC_IS_ERROR(status))
        s = "error";
    else if (NT_SC_IS_WARNING(status))
        s = "warning";
    else if (NT_SC_IS_INFO(status))
        s = "info";

    if (handle) {
        svc = handle->clnt->binding->service;
        name = svc->name;
    }

    smb_tracef("%s[0x%02x]: %s: %s (0x%08x)",
        name, opnum, s, xlate_nt_status(status), status);
}

/*
 * The following functions provide the client callback interface.
 * If the caller hasn't provided a heap, create one here.
 */
static int
ndr_xa_init(ndr_client_t *clnt, ndr_xa_t *mxa)
{
    ndr_stream_t    *recv_nds = &mxa->recv_nds;
    ndr_stream_t    *send_nds = &mxa->send_nds;
    ndr_heap_t  *heap = clnt->heap;
    int     rc;

    if (heap == NULL) {
        if ((heap = ndr_heap_create()) == NULL)
            return (-1);

        clnt->heap = heap;
    }

    mxa->heap = heap;

    rc = nds_initialize(send_nds, 0, NDR_MODE_CALL_SEND, heap);
    if (rc == 0)
        rc = nds_initialize(recv_nds, NDR_PDU_SIZE_HINT_DEFAULT,
            NDR_MODE_RETURN_RECV, heap);

    if (rc != 0) {
        nds_destruct(&mxa->recv_nds);
        nds_destruct(&mxa->send_nds);
        ndr_heap_destroy(mxa->heap);
        mxa->heap = NULL;
        clnt->heap = NULL;
        return (-1);
    }

    if (clnt->nonull)
        NDS_SETF(send_nds, NDS_F_NONULL);

    return (0);
}

/*
 * This is the entry pointy for an RPC client call exchange with
 * a server, which will result in an smbrdr SmbTransact request.
 *
 * SmbTransact should return the number of bytes received, which
 * we record as the PDU size, or a negative error code.
 */
static int
ndr_xa_exchange(ndr_client_t *clnt, ndr_xa_t *mxa)
{
    ndr_stream_t *recv_nds = &mxa->recv_nds;
    ndr_stream_t *send_nds = &mxa->send_nds;
    int nbytes;

    nbytes = smbrdr_transact(clnt->fid,
        (char *)send_nds->pdu_base_offset, send_nds->pdu_size,
        (char *)recv_nds->pdu_base_offset, recv_nds->pdu_max_size);

    if (nbytes < 0) {
        recv_nds->pdu_size = 0;
        return (-1);
    }

    recv_nds->pdu_size = nbytes;
    return (nbytes);
}

/*
 * This entry point will be invoked if the xa-exchange response contained
 * only the first fragment of a multi-fragment response.  The RPC client
 * code will then make repeated xa-read requests to obtain the remaining
 * fragments, which will result in smbrdr SmbReadX requests.
 *
 * SmbReadX should return the number of bytes received, in which case we
 * expand the PDU size to include the received data, or a negative error
 * code.
 */
static int
ndr_xa_read(ndr_client_t *clnt, ndr_xa_t *mxa)
{
    ndr_stream_t *nds = &mxa->recv_nds;
    int len;
    int nbytes;

    if ((len = (nds->pdu_max_size - nds->pdu_size)) < 0)
        return (-1);

    nbytes = smbrdr_readx(clnt->fid,
        (char *)nds->pdu_base_offset + nds->pdu_size, len);

    if (nbytes < 0)
        return (-1);

    nds->pdu_size += nbytes;

    if (nds->pdu_size > nds->pdu_max_size) {
        nds->pdu_size = nds->pdu_max_size;
        return (-1);
    }

    return (nbytes);
}

/*
 * Preserve the heap so that the client application has access to data
 * returned from the server after an RPC call.
 */
static void
ndr_xa_preserve(ndr_client_t *clnt, ndr_xa_t *mxa)
{
    assert(clnt->heap == mxa->heap);

    clnt->heap_preserved = B_TRUE;
    mxa->heap = NULL;
}

/*
 * Dispose of the transaction streams.  If the heap has not been
 * preserved, we can destroy it here.
 */
static void
ndr_xa_destruct(ndr_client_t *clnt, ndr_xa_t *mxa)
{
    nds_destruct(&mxa->recv_nds);
    nds_destruct(&mxa->send_nds);

    if (!clnt->heap_preserved) {
        ndr_heap_destroy(mxa->heap);
        mxa->heap = NULL;
        clnt->heap = NULL;
    }
}

/*
 * Dispose of a preserved heap.
 */
static void
ndr_xa_release(ndr_client_t *clnt)
{
    if (clnt->heap_preserved) {
        ndr_heap_destroy(clnt->heap);
        clnt->heap = NULL;
        clnt->heap_preserved = B_FALSE;
    }
}

/*
 * Lookup platform, type and version information about a server.
 * If the cache doesn't already contain the data, contact the server and
 * cache the response before returning the server info to the caller.
 *
 * We don't provide the name or comment for now, which avoids the need
 * to deal with unnecessary memory management.
 */
static int
ndr_svinfo_lookup(char *server, char *domain, srvsvc_server_info_t *svinfo)
{
    static boolean_t    timechecked = B_FALSE;
    ndr_svinfo_t *svi;

    (void) mutex_lock(&ndr_svlist.svl_mtx);
    if (!ndr_svlist.svl_init)
        return (-1);

    svi = list_head(&ndr_svlist.svl_list);
    while (svi != NULL) {
        if (ndr_svinfo_expired(svi)) {
            svi = list_head(&ndr_svlist.svl_list);
            continue;
        }

        if (ndr_svinfo_match(server, domain, svi)) {
            bcopy(&svi->svi_svinfo, svinfo,
                sizeof (srvsvc_server_info_t));
            svinfo->sv_name = NULL;
            svinfo->sv_comment = NULL;
            (void) mutex_unlock(&ndr_svlist.svl_mtx);
            return (0);
        }

        svi = list_next(&ndr_svlist.svl_list, svi);
    }

    if ((svi = malloc(sizeof (ndr_svinfo_t))) == NULL) {
        (void) mutex_unlock(&ndr_svlist.svl_mtx);
        return (-1);
    }

    if (srvsvc_net_server_getinfo(server, domain, &svi->svi_svinfo) < 0) {
        (void) mutex_unlock(&ndr_svlist.svl_mtx);
        free(svi);
        return (-1);
    }

    (void) time(&svi->svi_tcached);
    (void) strlcpy(svi->svi_server, server, MAXNAMELEN);
    (void) strlcpy(svi->svi_domain, domain, MAXNAMELEN);
    list_insert_tail(&ndr_svlist.svl_list, svi);
    bcopy(&svi->svi_svinfo, svinfo, sizeof (srvsvc_server_info_t));
    svinfo->sv_name = NULL;
    svinfo->sv_comment = NULL;

    if (!timechecked) {
        timechecked = B_TRUE;
        ndr_srvsvc_timecheck(server, domain);
    }

    (void) mutex_unlock(&ndr_svlist.svl_mtx);
    return (0);
}

static boolean_t
ndr_svinfo_match(const char *server, const char *domain,
    const ndr_svinfo_t *svi)
{
    if ((smb_strcasecmp(server, svi->svi_server, 0) == 0) &&
        (smb_strcasecmp(domain, svi->svi_domain, 0) == 0)) {
        return (B_TRUE);
    }

    return (B_FALSE);
}

/*
 * If the server info in the cache has expired, discard it and return true.
 * Otherwise return false.
 *
 * This is a private function to support ndr_svinfo_lookup() that assumes
 * the list mutex is held.
 */
static boolean_t
ndr_svinfo_expired(ndr_svinfo_t *svi)
{
    time_t  tnow;

    (void) time(&tnow);

    if (difftime(tnow, svi->svi_tcached) > NDR_SVINFO_TIMEOUT) {
        list_remove(&ndr_svlist.svl_list, svi);
        free(svi->svi_svinfo.sv_name);
        free(svi->svi_svinfo.sv_comment);
        free(svi);
        return (B_TRUE);
    }

    return (B_FALSE);
}

/*
 * Compare the time here with the remote time on the server
 * and report clock skew.
 */
void
ndr_srvsvc_timecheck(char *server, char *domain)
{
    char            hostname[MAXHOSTNAMELEN];
    struct timeval      dc_tv;
    struct tm       dc_tm;
    struct tm       *tm;
    time_t          tnow;
    time_t          tdiff;
    int         priority;

    if (srvsvc_net_remote_tod(server, domain, &dc_tv, &dc_tm) < 0) {
        syslog(LOG_DEBUG, "srvsvc_net_remote_tod failed");
        return;
    }

    tnow = time(NULL);

    if (tnow > dc_tv.tv_sec)
        tdiff = (tnow - dc_tv.tv_sec) / SECSPERMIN;
    else
        tdiff = (dc_tv.tv_sec - tnow) / SECSPERMIN;

    if (tdiff != 0) {
        (void) strlcpy(hostname, "localhost", MAXHOSTNAMELEN);
        (void) gethostname(hostname, MAXHOSTNAMELEN);

        priority = (tdiff > 2) ? LOG_NOTICE : LOG_DEBUG;
        syslog(priority, "DC [%s] clock skew detected: %u minutes",
            server, tdiff);

        tm = gmtime(&dc_tv.tv_sec);
        syslog(priority, "%-8s  UTC: %s", server, asctime(tm));
        tm = gmtime(&tnow);
        syslog(priority, "%-8s  UTC: %s", hostname, asctime(tm));
    }
}