/* 
   Unix SMB/CIFS implementation.
   SMB backend for the Common UNIX Printing System ("CUPS")
   Copyright 1999 by Easy Software Products
   Copyright Andrew Tridgell 1994-1998
   Copyright Andrew Bartlett 2002
   Copyright Rodrigo Fernandez-Vizarra 2005 
   
   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"

#define PW_MAX_BUF_SIZE          sysconf(_SC_GETPW_R_SIZE_MAX)
#define TICKET_CC_DIR            "/tmp"
#define CC_PREFIX                "krb5cc_" /* prefix of the ticket cache */
#define CC_MAX_FILE_LEN          24   
#define CC_MAX_FILE_PATH_LEN     (sizeof(TICKET_CC_DIR)-1)+ CC_MAX_FILE_LEN+2   
#define OVERWRITE                1   
#define KRB5CCNAME               "KRB5CCNAME"


/*
 * Globals...
 */

extern BOOL		in_client;	/* Boolean for client library */


/*
 * Local functions...
 */

static void		list_devices(void);
static struct cli_state *smb_complete_connection(const char *, const char *,int , const char *, const char *, const char *, const char *, int);
static struct cli_state	*smb_connect(const char *, const char *, int, const char *, const char *, const char *, const char *);
static int		smb_print(struct cli_state *, char *, FILE *);


/*
 * 'main()' - Main entry for SMB backend.
 */

 int				/* O - Exit status */
 main(int  argc,			/* I - Number of command-line arguments */
     char *argv[])		/* I - Command-line arguments */
{
  int		i;		/* Looping var */
  int		copies;		/* Number of copies */
  int 		port;		/* Port number */
  char		uri[1024],	/* URI */
		*sep,		/* Pointer to separator */
		*password;	/* Password */
  const char	*username,	/* Username */
		*server,	/* Server name */
		*printer;	/* Printer name */
  const char	*workgroup;	/* Workgroup */
  FILE		*fp;		/* File to print */
  int		status=0;		/* Status of LPD job */
  struct cli_state *cli;	/* SMB interface */

  /* we expect the URI in argv[0]. Detect the case where it is in argv[1] and cope */
  if (argc > 2 && strncmp(argv[0],"smb://", 6) && !strncmp(argv[1],"smb://", 6)) {
	  argv++;
	  argc--;
  }

  if (argc == 1)
  {
   /*
    * NEW!  In CUPS 1.1 the backends are run with no arguments to list the
    *       available devices.  These can be devices served by this backend
    *       or any other backends (i.e. you can have an SNMP backend that
    *       is only used to enumerate the available network printers... :)
    */

    list_devices();
    return (0);
  }

  if (argc < 6 || argc > 7)
  {
    fprintf(stderr, "Usage: %s [DEVICE_URI] job-id user title copies options [file]\n",
            argv[0]);
    fputs("       The DEVICE_URI environment variable can also contain the\n", stderr);
    fputs("       destination printer:\n", stderr);
    fputs("\n", stderr);
    fputs("           smb://[username:password@][workgroup/]server[:port]/printer\n", stderr);
    return (1);
  }

 /*
  * If we have 7 arguments, print the file named on the command-line.
  * Otherwise, print data from stdin...
  */


  if (argc == 6)
  {
   /*
    * Print from Copy stdin to a temporary file...
    */

    fp     = stdin;
    copies = 1;
  }
  else if ((fp = fopen(argv[6], "rb")) == NULL)
  {
    perror("ERROR: Unable to open print file");
    return (1);
  }
  else
    copies = atoi(argv[4]);

 /*
  * Find the URI...
  */

  if (getenv("DEVICE_URI") != NULL)
    strncpy(uri, getenv("DEVICE_URI"), sizeof(uri) - 1);
  else if (strncmp(argv[0], "smb://", 6) == 0)
    strncpy(uri, argv[0], sizeof(uri) - 1);
  else
  {
    fputs("ERROR: No device URI found in DEVICE_URI environment variable or argv[0] !\n", stderr);
    return (1);
  }

  uri[sizeof(uri) - 1] = '\0';

 /*
  * Extract the destination from the URI...
  */

  if ((sep = strrchr_m(uri, '@')) != NULL)
  {
    username = uri + 6;
    *sep++ = '\0';

    server = sep;

   /*
    * Extract password as needed...
    */

    if ((password = strchr_m(username, ':')) != NULL)
      *password++ = '\0';
    else
      password = "";
  }
  else
  {
    username = "";
    password = "";
    server   = uri + 6;
  }

  if ((sep = strchr_m(server, '/')) == NULL)
  {
    fputs("ERROR: Bad URI - need printer name!\n", stderr);
    return (1);
  }

  *sep++ = '\0';
  printer = sep;

  if ((sep = strchr_m(printer, '/')) != NULL)
  {
   /*
    * Convert to smb://[username:password@]workgroup/server/printer...
    */

    *sep++ = '\0';

    workgroup = server;
    server    = printer;
    printer   = sep;
  }
  else
    workgroup = NULL;
  
  if ((sep = strrchr_m(server, ':')) != NULL)
  {
    *sep++ = '\0';

    port=atoi(sep);
  }
  else
  	port=0;
	
 
 /*
  * Setup the SAMBA server state...
  */

  setup_logging("smbspool", True);

  in_client = True;   /* Make sure that we tell lp_load we are */

  if (!lp_load(dyn_CONFIGFILE, True, False, False))
  {
    fprintf(stderr, "ERROR: Can't load %s - run testparm to debug it\n", dyn_CONFIGFILE);
    return (1);
  }

  if (workgroup == NULL)
    workgroup = lp_workgroup();

  load_interfaces();

  do
  {
    if ((cli = smb_connect(workgroup, server, port, printer, username, password, argv[2])) == NULL)
    {
      if (getenv("CLASS") == NULL)
      {
        fprintf(stderr, "ERROR: Unable to connect to CIFS host, will retry in 60 seconds...");
        sleep (60); /* should just waiting and retrying fix authentication  ??? */
      }
      else
      {
        fprintf(stderr, "ERROR: Unable to connect to CIFS host, trying next printer...");
        return (1);
      }
    }
  }
  while (cli == NULL);

 /*
  * Now that we are connected to the server, ignore SIGTERM so that we
  * can finish out any page data the driver sends (e.g. to eject the
  * current page...  Only ignore SIGTERM if we are printing data from
  * stdin (otherwise you can't cancel raw jobs...)
  */

  if (argc < 7)
    CatchSignal(SIGTERM, SIG_IGN);

 /*
  * Queue the job...
  */

  for (i = 0; i < copies; i ++)
    if ((status = smb_print(cli, argv[3] /* title */, fp)) != 0)
      break;

  cli_shutdown(cli);

 /*
  * Return the queue status...
  */

  return (status);
}


/*
 * 'list_devices()' - List the available printers seen on the network...
 */

static void
list_devices(void)
{
 /*
  * Eventually, search the local workgroup for available hosts and printers.
  */

  puts("network smb \"Unknown\" \"Windows Printer via SAMBA\"");
}


/*
 * get the name of the newest ticket cache for the uid user.
 * pam_krb5 defines a non default ticket cache for each user
 */
static
char * get_ticket_cache( uid_t uid )
{
  SMB_STRUCT_DIR *tcdir;                  /* directory where ticket caches are stored */
  SMB_STRUCT_DIRENT *dirent;   /* directory entry */
  char *filename = NULL;       /* holds file names on the tmp directory */
  SMB_STRUCT_STAT buf;        
  char user_cache_prefix[CC_MAX_FILE_LEN];
  char file_path[CC_MAX_FILE_PATH_LEN];
  char *ticket_file = NULL;
  time_t t = 0;
  
  snprintf(user_cache_prefix, CC_MAX_FILE_LEN, "%s%d", CC_PREFIX, uid );
  tcdir = sys_opendir( TICKET_CC_DIR );
  if ( tcdir == NULL ) 
    return NULL; 
  
  while ( (dirent = sys_readdir( tcdir ) ) ) 
  { 
    filename = dirent->d_name;
    snprintf(file_path, CC_MAX_FILE_PATH_LEN,"%s/%s", TICKET_CC_DIR, filename); 
    if (sys_stat(file_path, &buf) == 0 ) 
    {
      if ( ( buf.st_uid == uid ) && ( S_ISREG(buf.st_mode) ) ) 
      {
        /*
         * check the user id of the file to prevent denial of
         * service attacks by creating fake ticket caches for the 
         * user
         */
        if ( strstr( filename, user_cache_prefix ) ) 
        {
          if ( buf.st_mtime > t ) 
          { 
            /*
             * a newer ticket cache found 
             */
            free(ticket_file);
            ticket_file=SMB_STRDUP(file_path);
            t = buf.st_mtime;
          }
        }
      }
    }
  }

  sys_closedir(tcdir);

  if ( ticket_file == NULL )
  {
#ifdef DEVELOPER
    /* no ticket cache found */
    fprintf(stderr, "ERROR: No ticket cache found for userid=%d\n", uid);
#endif
    return NULL;
  }

  return ticket_file;
}

static struct cli_state 
*smb_complete_connection(const char *myname,
            const char *server,
            int port,
            const char *username, 
            const char *password, 
            const char *workgroup, 
            const char *share,
            int flags)
{
  struct cli_state  *cli;    /* New connection */    
  NTSTATUS nt_status;
  
  /* Start the SMB connection */
  nt_status = cli_start_connection( &cli, myname, server, NULL, port, 
                                    Undefined, flags, NULL);
  if (!NT_STATUS_IS_OK(nt_status)) 
  {
    return NULL;      
  }
    
    
  if ( (username) && (*username) && 
      ((!password) || ((password) && (strlen(password) == 0 ))) && 
       (cli->use_kerberos) ) 
  {
    /* Use kerberos authentication */
    struct passwd *pw;
    char *cache_file;
    
    
    if ( !(pw = sys_getpwnam(username)) ) {
      fprintf(stderr,"ERROR Can not get %s uid\n", username);
      cli_shutdown(cli);
      return NULL;
    }

    /*
     * Get the ticket cache of the user to set KRB5CCNAME env
     * variable
     */
    cache_file = get_ticket_cache( pw->pw_uid );
    if ( cache_file == NULL ) 
    {
      fprintf(stderr, "ERROR: Can not get the ticket cache for %s\n", username);
      cli_shutdown(cli);
      return NULL;
    }

    if ( setenv(KRB5CCNAME, cache_file, OVERWRITE) < 0 ) 
    {
      fprintf(stderr, "ERROR: Can not add KRB5CCNAME to the environment");
      cli_shutdown(cli);
      free(cache_file);
      return NULL;
    }
    free(cache_file);

    /*
     * Change the UID of the process to be able to read the kerberos
     * ticket cache
     */
    setuid(pw->pw_uid);

  }
   
   
  if (!cli_session_setup(cli, username, password, strlen(password)+1, 
                         password, strlen(password)+1,
                         workgroup)) 
  {
    fprintf(stderr,"ERROR: Session setup failed: %s\n", cli_errstr(cli));
    if (NT_STATUS_V(cli_nt_error(cli)) == 
        NT_STATUS_V(NT_STATUS_MORE_PROCESSING_REQUIRED))
    {
      fprintf(stderr, "did you forget to run kinit?\n");
    }
    cli_shutdown(cli);

    return NULL;
  }
    
  if (!cli_send_tconX(cli, share, "?????", password, strlen(password)+1)) 
  {
    fprintf(stderr, "ERROR: Tree connect failed (%s)\n", cli_errstr(cli));
    cli_shutdown(cli);
    return NULL;
  }
    
  return cli;
}

/*
 * 'smb_connect()' - Return a connection to a server.
 */

static struct cli_state *    /* O - SMB connection */
smb_connect(const char *workgroup,    /* I - Workgroup */
            const char *server,    /* I - Server */
            const int port,    /* I - Port */
            const char *share,    /* I - Printer */
            const char *username,    /* I - Username */
            const char *password,    /* I - Password */
      const char *jobusername)   /* I - User who issued the print job */
{
  struct cli_state  *cli;    /* New connection */
  pstring    myname;    /* Client name */

 /*
  * Get the names and addresses of the client and server...
  */

  get_myname(myname);  

  /* See if we have a username first.  This is for backwards compatible 
     behavior with 3.0.14a */

  if ( username &&  *username )
  {
      cli = smb_complete_connection(myname, server, port, username, 
                                    password, workgroup, share, 0 );
      if (cli) 
        return cli;
  }
  
  /* 
   * Try to use the user kerberos credentials (if any) to authenticate
   */
  cli = smb_complete_connection(myname, server, port, jobusername, "", 
                                workgroup, share, 
                                CLI_FULL_CONNECTION_USE_KERBEROS );

  if (cli ) { return cli; }

  /*
   * last try. Use anonymous authentication
   */
  cli = smb_complete_connection(myname, server, port, "", "", 
                                workgroup, share, 0);

  /*
   * Return the new connection...
   */
  
  return (cli);
}


/*
 * 'smb_print()' - Queue a job for printing using the SMB protocol.
 */

static int				/* O - 0 = success, non-0 = failure */
smb_print(struct cli_state *cli,	/* I - SMB connection */
          char             *title,	/* I - Title/job name */
          FILE             *fp)		/* I - File to print */
{
  int	fnum;		/* File number */
  int	nbytes,		/* Number of bytes read */
	tbytes;		/* Total bytes read */
  char	buffer[8192],	/* Buffer for copy */
	*ptr;		/* Pointer into tile */


 /*
  * Sanitize the title...
  */

  for (ptr = title; *ptr; ptr ++)
    if (!isalnum((int)*ptr) && !isspace((int)*ptr))
      *ptr = '_';

 /*
  * Open the printer device...
  */

  if ((fnum = cli_open(cli, title, O_RDWR | O_CREAT | O_TRUNC, DENY_NONE)) == -1)
  {
    fprintf(stderr, "ERROR: %s opening remote spool %s\n",
            cli_errstr(cli), title);
    return (1);
  }

 /*
  * Copy the file to the printer...
  */

  if (fp != stdin)
    rewind(fp);

  tbytes = 0;

  while ((nbytes = fread(buffer, 1, sizeof(buffer), fp)) > 0)
  {
    if (cli_write(cli, fnum, 0, buffer, tbytes, nbytes) != nbytes)
    {
      fprintf(stderr, "ERROR: Error writing spool: %s\n", cli_errstr(cli));
      break;
    }

    tbytes += nbytes;
  } 

  if (!cli_close(cli, fnum))
  {
    fprintf(stderr, "ERROR: %s closing remote spool %s\n",
            cli_errstr(cli), title);
    return (1);
  }
  else
    return (0);
}