libsmb/clientgen.c

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/* 
   Unix SMB/CIFS implementation.
   SMB client generic functions
   Copyright (C) Andrew Tridgell 1994-1998
   
   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

extern int smb_read_error;

/****************************************************************************
 Change the timeout (in milliseconds).
****************************************************************************/

unsigned int cli_set_timeout(struct cli_state *cli, unsigned int timeout)
{
        unsigned int old_timeout = cli->timeout;
        cli->timeout = timeout;
        return old_timeout;
}

/****************************************************************************
 Change the port number used to call on.
****************************************************************************/

int cli_set_port(struct cli_state *cli, int port)
{
        cli->port = port;
        return port;
}

/****************************************************************************
 Read an smb from a fd ignoring all keepalive packets.
 The timeout is in milliseconds

 This is exactly the same as receive_smb except that it never returns
 a session keepalive packet (just as receive_smb used to do).
 receive_smb was changed to return keepalives as the oplock processing means this call
 should never go into a blocking read.
****************************************************************************/

static BOOL client_receive_smb(int fd,char *buffer, size_t bufsize, unsigned int timeout)
{
        BOOL ret;

        for(;;) {
                ret = receive_smb_raw(fd, buffer, bufsize, timeout);

                if (!ret) {
                        DEBUG(10,("client_receive_smb failed\n"));
                        show_msg(buffer);
                        return ret;
                }

                /* Ignore session keepalive packets. */
                if(CVAL(buffer,0) != SMBkeepalive)
                        break;
        }
        show_msg(buffer);
        return ret;
}

/****************************************************************************
 Recv an smb.
****************************************************************************/

BOOL cli_receive_smb(struct cli_state *cli)
{
        BOOL ret;

        /* fd == -1 causes segfaults -- Tom (tom@ninja.nl) */
        if (cli->fd == -1)
                return False; 

 again:
        ret = client_receive_smb(cli->fd,cli->inbuf, cli->bufsize, cli->timeout);
        
        if (ret) {
                /* it might be an oplock break request */
                if (!(CVAL(cli->inbuf, smb_flg) & FLAG_REPLY) &&
                    CVAL(cli->inbuf,smb_com) == SMBlockingX &&
                    SVAL(cli->inbuf,smb_vwv6) == 0 &&
                    SVAL(cli->inbuf,smb_vwv7) == 0) {
                        if (cli->oplock_handler) {
                                int fnum = SVAL(cli->inbuf,smb_vwv2);
                                unsigned char level = CVAL(cli->inbuf,smb_vwv3+1);
                                if (!cli->oplock_handler(cli, fnum, level)) return False;
                        }
                        /* try to prevent loops */
                        SCVAL(cli->inbuf,smb_com,0xFF);
                        goto again;
                }
        }

        /* If the server is not responding, note that now */
        if (!ret) {
                DEBUG(0, ("Receiving SMB: Server stopped responding\n"));
                cli->smb_rw_error = smb_read_error;
                close(cli->fd);
                cli->fd = -1;
                return ret;
        }

        if (!cli_check_sign_mac(cli)) {
                /*
                 * If we get a signature failure in sessionsetup, then
                 * the server sometimes just reflects the sent signature
                 * back to us. Detect this and allow the upper layer to
                 * retrieve the correct Windows error message.
                 */
                if (CVAL(cli->outbuf,smb_com) == SMBsesssetupX &&
                        (smb_len(cli->inbuf) > (smb_ss_field + 8 - 4)) &&
                        (SVAL(cli->inbuf,smb_flg2) & FLAGS2_SMB_SECURITY_SIGNATURES) &&
                        memcmp(&cli->outbuf[smb_ss_field],&cli->inbuf[smb_ss_field],8) == 0 &&
                        cli_is_error(cli)) {

                        /*
                         * Reflected signature on login error. 
                         * Set bad sig but don't close fd.
                         */
                        cli->smb_rw_error = READ_BAD_SIG;
                        return True;
                }

                DEBUG(0, ("SMB Signature verification failed on incoming packet!\n"));
                cli->smb_rw_error = READ_BAD_SIG;
                close(cli->fd);
                cli->fd = -1;
                return False;
        };
        return True;
}

static ssize_t write_socket(int fd, const char *buf, size_t len)
{
        ssize_t ret=0;
                                                                                                                                            
        DEBUG(6,("write_socket(%d,%d)\n",fd,(int)len));
        ret = write_data(fd,buf,len);
                                                                                                                                            
        DEBUG(6,("write_socket(%d,%d) wrote %d\n",fd,(int)len,(int)ret));
        if(ret <= 0)
                DEBUG(0,("write_socket: Error writing %d bytes to socket %d: ERRNO = %s\n",
                        (int)len, fd, strerror(errno) ));
                                                                                                                                            
        return(ret);
}

/****************************************************************************
 Send an smb to a fd.
****************************************************************************/

BOOL cli_send_smb(struct cli_state *cli)
{
        size_t len;
        size_t nwritten=0;
        ssize_t ret;

        /* fd == -1 causes segfaults -- Tom (tom@ninja.nl) */
        if (cli->fd == -1)
                return False;

        cli_calculate_sign_mac(cli);

        len = smb_len(cli->outbuf) + 4;

        while (nwritten < len) {
                ret = write_socket(cli->fd,cli->outbuf+nwritten,len - nwritten);
                if (ret <= 0) {
                        close(cli->fd);
                        cli->fd = -1;
                        cli->smb_rw_error = WRITE_ERROR;
                        DEBUG(0,("Error writing %d bytes to client. %d (%s)\n",
                                (int)len,(int)ret, strerror(errno) ));
                        return False;
                }
                nwritten += ret;
        }
        /* Increment the mid so we can tell between responses. */
        cli->mid++;
        if (!cli->mid)
                cli->mid++;
        return True;
}

/****************************************************************************
 Setup basics in a outgoing packet.
****************************************************************************/

void cli_setup_packet(struct cli_state *cli)
{
        cli->rap_error = 0;
        SSVAL(cli->outbuf,smb_pid,cli->pid);
        SSVAL(cli->outbuf,smb_uid,cli->vuid);
        SSVAL(cli->outbuf,smb_mid,cli->mid);
        if (cli->protocol > PROTOCOL_CORE) {
                uint16 flags2;
                if (cli->case_sensitive) {
                        SCVAL(cli->outbuf,smb_flg,0x0);
                } else {
                        /* Default setting, case insensitive. */
                        SCVAL(cli->outbuf,smb_flg,0x8);
                }
                flags2 = FLAGS2_LONG_PATH_COMPONENTS;
                if (cli->capabilities & CAP_UNICODE)
                        flags2 |= FLAGS2_UNICODE_STRINGS;
                if ((cli->capabilities & CAP_DFS) && cli->dfsroot)
                        flags2 |= FLAGS2_DFS_PATHNAMES;
                if (cli->capabilities & CAP_STATUS32)
                        flags2 |= FLAGS2_32_BIT_ERROR_CODES;
                if (cli->use_spnego)
                        flags2 |= FLAGS2_EXTENDED_SECURITY;
                SSVAL(cli->outbuf,smb_flg2, flags2);
        }
}

/****************************************************************************
 Setup the bcc length of the packet from a pointer to the end of the data.
****************************************************************************/

void cli_setup_bcc(struct cli_state *cli, void *p)
{
        set_message_bcc(cli->outbuf, PTR_DIFF(p, smb_buf(cli->outbuf)));
}

/****************************************************************************
 Initialise credentials of a client structure.
****************************************************************************/

void cli_init_creds(struct cli_state *cli, const char *username, const char *domain, const char *password)
{
        fstrcpy(cli->domain, domain);
        fstrcpy(cli->user_name, username);
        pwd_set_cleartext(&cli->pwd, password);
        if (!*username) {
                cli->pwd.null_pwd = True;
        }

        DEBUG(10,("cli_init_creds: user %s domain %s\n", cli->user_name, cli->domain));
}

/****************************************************************************
 Set the signing state (used from the command line).
****************************************************************************/

void cli_setup_signing_state(struct cli_state *cli, int signing_state)
{
        if (signing_state == Undefined)
                return;

        if (signing_state == False) {
                cli->sign_info.allow_smb_signing = False;
                cli->sign_info.mandatory_signing = False;
                return;
        }

        cli->sign_info.allow_smb_signing = True;

        if (signing_state == Required) 
                cli->sign_info.mandatory_signing = True;
}

/****************************************************************************
 Initialise a client structure. Always returns a malloc'ed struct.
****************************************************************************/

struct cli_state *cli_initialise(void)
{
        struct cli_state *cli = NULL;

        /* Check the effective uid - make sure we are not setuid */
        if (is_setuid_root()) {
                DEBUG(0,("libsmb based programs must *NOT* be setuid root.\n"));
                return NULL;
        }

        cli = SMB_MALLOC_P(struct cli_state);
        if (!cli) {
                return NULL;
        }

        ZERO_STRUCTP(cli);

        cli->port = 0;
        cli->fd = -1;
        cli->cnum = -1;
        cli->pid = (uint16)sys_getpid();
        cli->mid = 1;
        cli->vuid = UID_FIELD_INVALID;
        cli->protocol = PROTOCOL_NT1;
        cli->timeout = 20000; /* Timeout is in milliseconds. */
        cli->bufsize = CLI_BUFFER_SIZE+4;
        cli->max_xmit = cli->bufsize;
        cli->outbuf = (char *)SMB_MALLOC(cli->bufsize+SAFETY_MARGIN);
        cli->inbuf = (char *)SMB_MALLOC(cli->bufsize+SAFETY_MARGIN);
        cli->oplock_handler = cli_oplock_ack;
        cli->case_sensitive = False;
        cli->smb_rw_error = 0;

        cli->use_spnego = lp_client_use_spnego();

        cli->capabilities = CAP_UNICODE | CAP_STATUS32 | CAP_DFS;

        /* Set the CLI_FORCE_DOSERR environment variable to test
           client routines using DOS errors instead of STATUS32
           ones.  This intended only as a temporary hack. */    
        if (getenv("CLI_FORCE_DOSERR"))
                cli->force_dos_errors = True;

        if (lp_client_signing()) 
                cli->sign_info.allow_smb_signing = True;

        if (lp_client_signing() == Required) 
                cli->sign_info.mandatory_signing = True;
                                   
        if (!cli->outbuf || !cli->inbuf)
                goto error;

        if ((cli->mem_ctx = talloc_init("cli based talloc")) == NULL)
                goto error;

        memset(cli->outbuf, 0, cli->bufsize);
        memset(cli->inbuf, 0, cli->bufsize);


#if defined(DEVELOPER)
        /* just because we over-allocate, doesn't mean it's right to use it */
        clobber_region(FUNCTION_MACRO, __LINE__, cli->outbuf+cli->bufsize, SAFETY_MARGIN);
        clobber_region(FUNCTION_MACRO, __LINE__, cli->inbuf+cli->bufsize, SAFETY_MARGIN);
#endif

        /* initialise signing */
        cli_null_set_signing(cli);

        cli->initialised = 1;

        return cli;

        /* Clean up after malloc() error */

 error:

        SAFE_FREE(cli->inbuf);
        SAFE_FREE(cli->outbuf);
        SAFE_FREE(cli);
        return NULL;
}

/****************************************************************************
 External interface.
 Close an open named pipe over SMB. Free any authentication data.
 Returns False if the cli_close call failed.
 ****************************************************************************/

BOOL cli_rpc_pipe_close(struct rpc_pipe_client *cli)
{
        BOOL ret;

        if (!cli) {
                return False;
        }

        ret = cli_close(cli->cli, cli->fnum);

        if (!ret) {
                DEBUG(1,("cli_rpc_pipe_close: cli_close failed on pipe %s, "
                         "fnum 0x%x "
                         "to machine %s.  Error was %s\n",
                         cli->pipe_name,
                         (int) cli->fnum,
                         cli->cli->desthost,
                         cli_errstr(cli->cli)));
        }

        if (cli->auth.cli_auth_data_free_func) {
                (*cli->auth.cli_auth_data_free_func)(&cli->auth);
        }

        DEBUG(10,("cli_rpc_pipe_close: closed pipe %s to machine %s\n",
                cli->pipe_name, cli->cli->desthost ));

        DLIST_REMOVE(cli->cli->pipe_list, cli);
        talloc_destroy(cli->mem_ctx);
        return ret;
}

/****************************************************************************
 Close all pipes open on this session.
****************************************************************************/

void cli_nt_pipes_close(struct cli_state *cli)
{
        struct rpc_pipe_client *cp, *next;

        for (cp = cli->pipe_list; cp; cp = next) {
                next = cp->next;
                cli_rpc_pipe_close(cp);
        }
}

/****************************************************************************
 Shutdown a client structure.
****************************************************************************/

void cli_shutdown(struct cli_state *cli)
{
        cli_nt_pipes_close(cli);

        /*
         * tell our peer to free his resources.  Wihtout this, when an
         * application attempts to do a graceful shutdown and calls
         * smbc_free_context() to clean up all connections, some connections
         * can remain active on the peer end, until some (long) timeout period
         * later.  This tree disconnect forces the peer to clean up, since the
         * connection will be going away.
         *
         * Also, do not do tree disconnect when cli->smb_rw_error is DO_NOT_DO_TDIS
         * the only user for this so far is smbmount which passes opened connection
         * down to kernel's smbfs module.
         */
        if ( (cli->cnum != (uint16)-1) && (cli->smb_rw_error != DO_NOT_DO_TDIS ) ) {
                cli_tdis(cli);
        }
        
        SAFE_FREE(cli->outbuf);
        SAFE_FREE(cli->inbuf);

        cli_free_signing_context(cli);
        data_blob_free(&cli->secblob);
        data_blob_free(&cli->user_session_key);

        if (cli->mem_ctx) {
                talloc_destroy(cli->mem_ctx);
                cli->mem_ctx = NULL;
        }

        if (cli->fd != -1) {
                close(cli->fd);
        }
        cli->fd = -1;
        cli->smb_rw_error = 0;

        SAFE_FREE(cli);
}

/****************************************************************************
 Set socket options on a open connection.
****************************************************************************/

void cli_sockopt(struct cli_state *cli, const char *options)
{
        set_socket_options(cli->fd, options);
}

/****************************************************************************
 Set the PID to use for smb messages. Return the old pid.
****************************************************************************/

uint16 cli_setpid(struct cli_state *cli, uint16 pid)
{
        uint16 ret = cli->pid;
        cli->pid = pid;
        return ret;
}

/****************************************************************************
 Set the case sensitivity flag on the packets. Returns old state.
****************************************************************************/

BOOL cli_set_case_sensitive(struct cli_state *cli, BOOL case_sensitive)
{
        BOOL ret = cli->case_sensitive;
        cli->case_sensitive = case_sensitive;
        return ret;
}

/****************************************************************************
Send a keepalive packet to the server
****************************************************************************/

BOOL cli_send_keepalive(struct cli_state *cli)
{
        if (cli->fd == -1) {
                DEBUG(3, ("cli_send_keepalive: fd == -1\n"));
                return False;
        }
        if (!send_keepalive(cli->fd)) {
                close(cli->fd);
                cli->fd = -1;
                DEBUG(0,("Error sending keepalive packet to client.\n"));
                return False;
        }
        return True;
}

/****************************************************************************
 Send/receive a SMBecho command: ping the server
****************************************************************************/

BOOL cli_echo(struct cli_state *cli, unsigned char *data, size_t length)
{
        char *p;

        SMB_ASSERT(length < 1024);

        memset(cli->outbuf,'\0',smb_size);
        set_message(cli->outbuf,1,length,True);
        SCVAL(cli->outbuf,smb_com,SMBecho);
        SSVAL(cli->outbuf,smb_tid,65535);
        SSVAL(cli->outbuf,smb_vwv0,1);
        cli_setup_packet(cli);
        p = smb_buf(cli->outbuf);
        memcpy(p, data, length);
        p += length;

        cli_setup_bcc(cli, p);

        cli_send_smb(cli);
        if (!cli_receive_smb(cli)) {
                return False;
        }

        if (cli_is_error(cli)) {
                return False;
        }
        return True;
}

---