backend/scsi-linux.c

   1 /*
   2  * "$Id: scsi-linux.c 4703 2005-09-26 19:33:58Z mike $"
   3  *
   4  *   Linux SCSI printer support for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 2003-2005 by Easy Software Products, all rights reserved.
   7  *
   8  *   Redistribution and use in source and binary forms, with or
   9  *   without modification, are permitted provided that the
  10  *   following conditions are met:
  11  *
  12  *     1. Redistributions of source code must retain the above
  13  *        copyright notice, this list of conditions and the
  14  *        following disclaimer.
  15  *
  16  *     2. Redistributions in binary form must reproduce the
  17  *        above copyright notice, this list of conditions and
  18  *        the following disclaimer in the documentation and/or
  19  *        other materials provided with the distribution.
  20  *
  21  *     3. All advertising materials mentioning features or use
  22  *        of this software must display the following
  23  *        acknowledgement:
  24  *
  25  *          This product includes software developed by Easy
  26  *          Software Products.
  27  *
  28  *     4. The name of Easy Software Products may not be used to
  29  *        endorse or promote products derived from this software
  30  *        without specific prior written permission.
  31  *
  32  *   THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS
  33  *   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
  34  *   BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  35  *   MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  36  *   DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS
  37  *   BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  38  *   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  39  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  40  *   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  41  *   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  42  *   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  43  *   OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  44  *   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  45  *   DAMAGE.
  46  *
  47  * Contents:
  48  *
  49  *   list_devices() - List the available SCSI printer devices.
  50  *   print_device() - Print a file to a SCSI device.
  51  */
  52
  53 /*
  54  * Include necessary headers.
  55  */
  56
  57 #include <scsi/sg.h>
  58
  59
  60 /*
  61  * We currently only support the Linux 2.4 generic SCSI interface.
  62  */
  63
  64 #ifndef SG_DXFER_TO_DEV
  65 /*
  66  * Dummy functions that do nothing on unsupported platforms...
  67  */
  68 void    list_devices(void) {}
  69 int     print_device(const char *resource, int fd, int copies) { return (1); }
  70 #else
  71
  72
  73 /*
  74  * 'list_devices()' - List the available SCSI printer devices.
  75  */
  76
  77 void
  78 list_devices(void)
  79 {
  80   puts("direct scsi \"Unknown\" \"SCSI Printer\"");
  81 }
  82
  83
  84 /*
  85  * 'print_device()' - Print a file to a SCSI device.
  86  */
  87
  88 int                                     /* O - Print status */
  89 print_device(const char *resource,      /* I - SCSI device */
  90              int        fd,             /* I - File to print */
  91              int        copies)         /* I - Number of copies to print */
  92 {
  93   int           scsi_fd;                /* SCSI file descriptor */
  94   char          buffer[8192];           /* Data buffer */
  95   int           bytes;                  /* Number of bytes */
  96   int           try;                    /* Current try */
  97   sg_io_hdr_t   scsi_req;               /* SCSI request */
  98   unsigned char scsi_cmd[6],            /* SCSI command data */
  99                 scsi_sense[32];         /* SCSI sense data */
 100 #  if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
 101   struct sigaction action;              /* Actions for POSIX signals */
 102 #  endif /* HAVE_SIGACTION && !HAVE_SIGSET */
 103
 104
 105  /*
 106   * Make sure we have a valid resource name...
 107   */
 108
 109   if (strncmp(resource, "/dev/sg", 7) != 0)
 110   {
 111     fprintf(stderr, "ERROR: Bad SCSI device file \"%s\"!\n", resource);
 112     return (CUPS_BACKEND_STOP);
 113   }
 114
 115  /*
 116   * Open the SCSI device file...
 117   */
 118
 119   do
 120   {
 121     if ((scsi_fd = open(resource, O_RDWR | O_EXCL)) == -1)
 122     {
 123       if (getenv("CLASS") != NULL)
 124       {
 125        /*
 126         * If the CLASS environment variable is set, the job was submitted
 127         * to a class and not to a specific queue.  In this case, we want
 128         * to abort immediately so that the job can be requeued on the next
 129         * available printer in the class.
 130         */
 131
 132         fputs("INFO: Unable to open SCSI device, queuing on next printer in class...\n",
 133               stderr);
 134
 135        /*
 136         * Sleep 5 seconds to keep the job from requeuing too rapidly...
 137         */
 138
 139         sleep(5);
 140
 141         return (CUPS_BACKEND_FAILED);
 142       }
 143
 144       if (errno != EAGAIN && errno != EBUSY)
 145       {
 146         fprintf(stderr, "ERROR: Unable to open SCSI device \"%s\" - %s\n",
 147                 resource, strerror(errno));
 148         return (CUPS_BACKEND_FAILED);
 149       }
 150       else
 151       {
 152         fprintf(stderr, "INFO: SCSI device \"%s\" busy; retrying...\n",
 153                 resource);
 154         sleep(30);
 155       }
 156     }
 157   }
 158   while (scsi_fd == -1);
 159
 160  /*
 161   * Now that we are "connected" to the port, ignore SIGTERM so that we
 162   * can finish out any page data the driver sends (e.g. to eject the
 163   * current page...  Only ignore SIGTERM if we are printing data from
 164   * stdin (otherwise you can't cancel raw jobs...)
 165   */
 166
 167   if (fd != 0)
 168   {
 169 #  ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
 170     sigset(SIGTERM, SIG_IGN);
 171 #  elif defined(HAVE_SIGACTION)
 172     memset(&action, 0, sizeof(action));
 173
 174     sigemptyset(&action.sa_mask);
 175     action.sa_handler = SIG_IGN;
 176     sigaction(SIGTERM, &action, NULL);
 177 #  else
 178     signal(SIGTERM, SIG_IGN);
 179 #  endif /* HAVE_SIGSET */
 180   }
 181
 182  /*
 183   * Copy the print file to the device...
 184   */
 185
 186   while (copies > 0)
 187   {
 188     if (fd != 0)
 189       lseek(fd, 0, SEEK_SET);
 190
 191     while ((bytes = read(fd, buffer, sizeof(buffer))) > 0)
 192     {
 193       memset(&scsi_req, 0, sizeof(scsi_req));
 194
 195       scsi_req.interface_id    = 'S';
 196       scsi_req.dxfer_direction = SG_DXFER_TO_DEV;
 197       scsi_req.cmd_len         = 6;
 198       scsi_req.mx_sb_len       = sizeof(scsi_sense);
 199       scsi_req.iovec_count     = 0;
 200       scsi_req.dxfer_len       = bytes;
 201       scsi_req.dxferp          = buffer;
 202       scsi_req.cmdp            = scsi_cmd;
 203       scsi_req.sbp             = scsi_sense;
 204       scsi_req.timeout         = 60 * 1000;
 205
 206       scsi_cmd[0] = 0x0a;       /* Group 0 print command */
 207       scsi_cmd[1] = 0x00;
 208       scsi_cmd[2] = bytes / 65536;
 209       scsi_cmd[3] = bytes / 256;
 210       scsi_cmd[4] = bytes;
 211       scsi_cmd[5] = 0x00;
 212
 213       for (try = 0; try < 10; try ++)
 214         if (ioctl(scsi_fd, SG_IO, &scsi_req) < 0 ||
 215             scsi_req.status != 0)
 216         {
 217           fprintf(stderr, "WARNING: SCSI command timed out (%d); retrying...\n",
 218                   scsi_req.status);
 219           sleep(try + 1);
 220         }
 221         else
 222           break;
 223
 224       if (try >= 10)
 225       {
 226         fprintf(stderr, "ERROR: Unable to send print data (%d)\n",
 227                 scsi_req.status);
 228         close(scsi_fd);
 229         return (CUPS_BACKEND_FAILED);
 230       }
 231     }
 232
 233     copies --;
 234   }
 235
 236  /*
 237   * Close the device and return...
 238   */
 239
 240   close(fd);
 241
 242   return (CUPS_BACKEND_OK);
 243 }
 244 #endif /* !SG_DXFER_TO_DEV */
 245
 246
 247 /*
 248  * End of "$Id: scsi-linux.c 4703 2005-09-26 19:33:58Z mike $".
 249  */