source: vendor/current/source3/smbd/error.c

/* 
   Unix SMB/CIFS implementation.
   error packet handling
   Copyright (C) Andrew Tridgell 1992-1998

   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 "smbd/smbd.h"
#include "smbd/globals.h"

bool use_nt_status(void)
{
        return lp_nt_status_support() && (global_client_caps & CAP_STATUS32);
}

/****************************************************************************
 Create an error packet. Normally called using the ERROR() macro.

 Setting eclass and ecode to zero and status to a valid NT error will
 reply with an NT error if the client supports CAP_STATUS32, otherwise
 it maps to and returns a DOS error if the client doesn't support CAP_STATUS32.
 This is the normal mode of calling this function via reply_nterror(req, status).

 Setting eclass and ecode to non-zero and status to NT_STATUS_OK (0) will map
 from a DOS error to an NT error and reply with an NT error if the client
 supports CAP_STATUS32, otherwise it replies with the given DOS error.
 This mode is currently not used in the server.

 Setting both eclass, ecode and status to non-zero values allows a non-default
 mapping from NT error codes to DOS error codes, and will return one or the
 other depending on the client supporting CAP_STATUS32 or not. This is the
 path taken by calling reply_botherror(req, eclass, ecode, status);

 Setting status to NT_STATUS_DOS(eclass, ecode) forces DOS errors even if the
 client supports CAP_STATUS32. This is the path taken to force a DOS error
 reply by calling reply_force_doserror(req, eclass, ecode).

 Setting status only and eclass to -1 forces NT errors even if the client
 doesn't support CAP_STATUS32. This mode is currently never used in the
 server.
****************************************************************************/

void error_packet_set(char *outbuf, uint8_t eclass, uint32_t ecode, NTSTATUS ntstatus, int line, const char *file)
{
        bool force_nt_status = False;
        bool force_dos_status = False;

        if (eclass == (uint8_t)-1) {
                force_nt_status = True;
        } else if (NT_STATUS_IS_DOS(ntstatus)) {
                force_dos_status = True;
        }

        if (force_nt_status || (!force_dos_status && lp_nt_status_support() && (global_client_caps & CAP_STATUS32))) {
                /* We're returning an NT error. */
                if (NT_STATUS_V(ntstatus) == 0 && eclass) {
                        ntstatus = dos_to_ntstatus(eclass, ecode);
                }
                SIVAL(outbuf,smb_rcls,NT_STATUS_V(ntstatus));
                SSVAL(outbuf,smb_flg2, SVAL(outbuf,smb_flg2)|FLAGS2_32_BIT_ERROR_CODES);
                /* This must not start with the word 'error', as this
                 * is reserved in the subunit stream protocol, causing
                 * false errors to show up when debugging is turned
                 * on */
                DEBUG(3,("NT error packet at %s(%d) cmd=%d (%s) %s\n",
                         file, line,
                         (int)CVAL(outbuf,smb_com),
                         smb_fn_name(CVAL(outbuf,smb_com)),
                         nt_errstr(ntstatus)));
        } else {
                /* We're returning a DOS error only,
                 * nt_status_to_dos() pulls DOS error codes out of the
                 * NTSTATUS */
                if (NT_STATUS_IS_DOS(ntstatus) || (eclass == 0 && NT_STATUS_V(ntstatus))) {
                        ntstatus_to_dos(ntstatus, &eclass, &ecode);
                }

                SSVAL(outbuf,smb_flg2, SVAL(outbuf,smb_flg2)&~FLAGS2_32_BIT_ERROR_CODES);
                SSVAL(outbuf,smb_rcls,eclass);
                SSVAL(outbuf,smb_err,ecode);  

                /* This must not start with the word 'error', as this
                 * is reserved in the subunit stream protocol, causing
                 * false errors to show up when debugging is turned
                 * on */
                DEBUG(3,("DOS error packet at %s(%d) cmd=%d (%s) eclass=%d ecode=%d\n",
                          file, line,
                          (int)CVAL(outbuf,smb_com),
                          smb_fn_name(CVAL(outbuf,smb_com)),
                          eclass,
                          ecode));
        }
}

int error_packet(char *outbuf, uint8_t eclass, uint32_t ecode, NTSTATUS ntstatus, int line, const char *file)
{
        int outsize = srv_set_message(outbuf,0,0,True);
        error_packet_set(outbuf, eclass, ecode, ntstatus, line, file);
        return outsize;
}

void reply_nt_error(struct smb_request *req, NTSTATUS ntstatus,
                    int line, const char *file)
{
        TALLOC_FREE(req->outbuf);
        reply_outbuf(req, 0, 0);
        error_packet_set((char *)req->outbuf, 0, 0, ntstatus, line, file);
}

/****************************************************************************
 Forces a DOS error on the wire.
****************************************************************************/

void reply_force_dos_error(struct smb_request *req, uint8_t eclass, uint32_t ecode,
                    int line, const char *file)
{
        TALLOC_FREE(req->outbuf);
        reply_outbuf(req, 0, 0);
        error_packet_set((char *)req->outbuf,
                        eclass, ecode,
                        NT_STATUS_DOS(eclass, ecode),
                        line,
                        file);
}

void reply_both_error(struct smb_request *req, uint8_t eclass, uint32_t ecode,
                      NTSTATUS status, int line, const char *file)
{
        TALLOC_FREE(req->outbuf);
        reply_outbuf(req, 0, 0);
        error_packet_set((char *)req->outbuf, eclass, ecode, status,
                         line, file);
}

void reply_openerror(struct smb_request *req, NTSTATUS status)
{
        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_COLLISION)) {
                /*
                 * We hit an existing file, and if we're returning DOS
                 * error codes OBJECT_NAME_COLLISION would map to
                 * ERRDOS/183, we need to return ERRDOS/80, see bug
                 * 4852.
                 */
                reply_botherror(req, NT_STATUS_OBJECT_NAME_COLLISION,
                        ERRDOS, ERRfilexists);
        } else if (NT_STATUS_EQUAL(status, NT_STATUS_TOO_MANY_OPENED_FILES)) {
                /* EMFILE always seems to be returned as a DOS error.
                 * See bug 6837. NOTE this forces a DOS error on the wire
                 * even though it's calling reply_nterror(). */
                reply_force_doserror(req, ERRDOS, ERRnofids);
        } else {
                reply_nterror(req, status);
        }
}