One "usb" CUPS backend for both libusb-based and usblp-based access

[michaelrsweet]

Version: -feature CUPS.org User: till.kamppeter

On Linux (and perhaps some other Unixes), the "usb" backend can currently be either compiled to access the printers through the "usblp" kernel module (/dev/usb/lp*) or through libusb (low-level USB), but one cannot have one backend which uses both access methods.

This causes a problem when transferring Linux distributions from the use of the kernel module to the use of libusb. Reasons why to switch libusb are:

1. HPLIP (and soon perhaps more manufacturer-supplied backends) is libusb-based, it grabs the device and takes it away from the usblip-based usb backend of. This causes some confusion, especially the UDEV scripts must always check both the low-level signals and the usblp signals coming from the printer to reliably determine when a printer appears and when it disappears.
2. The usblp-based backend disables bi-di access for several important manufacturers, as usblp does not work with most printers of them.
3. The libusb-based backend supports also some more general access, for example to allow printing and non-printing functions on an MF device to be done in parallel. This allows to drop many manufacturer-supplied CUPS backends in the future.
4. The possibility to get the serial number from every printer, even if the device ID does not contain it.

Problems of the switchover are caused by the absence of the usblp kernel module, for example printer firmware upload through /dev/usb/lp*, ecputil, libinklevel, ... Also URIs have changed and so printers created with the usb backend of CUPS 1.3.x will not work with the new 1ibusb-based backend.

The attached patch make one "usb" backend out of the two. This new backend

• Uses both access methods: libusb and the usblp kernel module
• Discovers always all printers independent which ones are attached to the kernel module and which ones has to get accessed directly through libusb
• Algorithms to generate the make and model part of the URIs are identical now for both access methods, serial number and interface is added to the URI if available
• As an URI determined via libusb can have additional serial number and interface parts the URI matching for printing a file is made more tolerant now. URIs which only differ by the presence of an interface part or URIs with and without serial number are considered equal. So on a printer discovered through the usblp module one can print when the kernel module is detached or not loaded. This is especially important for print queues which were created with CUPS 1.3.x or older. They simply keep working now, even when unloading the kernel module.
• Linux distributions will have the possibility to let the user work with or without usblp kernel module, without needing two different CUPS packages.

The attached patch is done in a somehow minimum invasive way, keeping the changes small. Probably one can simplify the code. It was also not tested whether whether it works with all possibilities of conditional compiling. I have tested on both the HP LaserJet 3390 and the HP PhotoSmart C8100. On both printers one can print with and without "usblp" loaded and without needing to re-create the print queues.

The patch is for CUPS 1.4.1.

[michaelrsweet]

CUPS.org User: till.kamppeter

Updated the patch for CUPS 1.4.3.

[michaelrsweet]

CUPS.org User: till.kamppeter

As talked about with Mike Sweet on the OpenPrinting Summit 2010 I have updated the patch. With this an easy transition between usblp and libusb without need to change the URIs of existing queues is possible and users of binary packages in distributions can choose whether they want to use usblp or libusb.

The patch is already in use in the Debian and Ubuntu distributions for several months and there are no user complaints about it.

[michaelrsweet]

CUPS.org User: sbd

Great patch, but there's no allowance made for "--disable-libusb", so I've posted a revison that does.

[michaelrsweet]

CUPS.org User: mike

Sorry, we have decided this issue will not be addressed in a CUPS release.

[michaelrsweet]

"usb-backend-both-usblp-and-libusb.patch":

--- backend/Makefile.orig 2009-09-29 14:22:59.000000000 +0200 +++ backend/Makefile 2009-09-29 14:24:47.000000000 +0200 @@ -267,7 +267,7 @@ echo Linking $@... $(CC) $(LDFLAGS) -o usb usb.o libbackend.a $(LIBUSB) \ $(BACKLIBS) $(LIBS) -usb.o: usb.c usb-darwin.c usb-libusb.c usb-unix.c +usb.o: usb.c usb-darwin.c usb-hybrid.c usb-libusb.c usb-unix.c

# --- backend/ieee1284.c.orig 2009-09-29 16:53:31.000000000 +0200 +++ backend/ieee1284.c 2009-09-29 17:01:15.000000000 +0200 @@ -275,6 +275,7 @@ cups_option_t values; / Keys and values in device ID / const char *mfg, / Manufacturer / *mdl, / Model */

• des, / Description / *sern; / Serial number / char temp[256], / Temporary manufacturer string / *tempptr; / Pointer into temp string */ @@ -305,10 +306,20 @@ } else {
• strlcpy(temp, make_model, sizeof(temp));
• /*
• * No manufacturer? Use the model string or description...
• */ +
• if (mdl)
• _ppdNormalizeMakeAndModel(mdl, temp, sizeof(temp));
• else if ((des = cupsGetOption("DESCRIPTION", num_values, values)) != NULL ||
• (des = cupsGetOption("DES", num_values, values)) != NULL)
• _ppdNormalizeMakeAndModel(des, temp, sizeof(temp));
• else

• strlcpy(temp, "Unknown", sizeof(temp));

  if ((tempptr = strchr(temp, ' ')) != NULL)

• *tempptr = '\0';

• *tempptr = '\0';

  mfg = temp; } --- backend/usb-hybrid.c.orig 2009-09-30 10:11:29.000000000 +0200 +++ backend/usb-hybrid.c 2009-09-30 09:29:52.000000000 +0200 @@ -0,0 +1,87 @@ +/*

• * "$Id: usb-hybrid.c 8807 2009-08-31 18:45:43Z mike $"
• *
• * USB port backend for the Common UNIX Printing System (CUPS).
• *
• * This file is included from "usb.c" when compiled on Linux.
• *
• * Copyright 2007-2008 by Apple Inc.
• * Copyright 1997-2007 by Easy Software Products, all rights reserved.
• *
• * These coded instructions, statements, and computer programs are the
• * property of Apple Inc. and are protected by Federal copyright
• * law. Distribution and use rights are outlined in the file "LICENSE.txt"
• * "LICENSE" which should have been included with this file. If this
• * file is missing or damaged, see the license at "http://www.cups.org/".
• *
• * This file is subject to the Apple OS-Developed Software exception.
• *
• * Contents:
• *
• * print_device() - Print a file to a USB device.
• * list_devices() - List all USB devices.
• / + +/
• * Include necessary headers.
• / + +#include <sys/select.h> + +/
• * Include the two USB implementations used under Linux ...
• / + +#include "usb-libusb.c" +#include "usb-unix.c" + +/
• * 'print_device()' - Print a file to a USB device.
• / + +int / O - Exit status _/ +printdevice(const char *uri, / I - Device URI */
• const char hostname, / I - Hostname/manufacturer */
• const char resource, / I - Resource/modelname */
• char options, / I - Device options/serial number */
• int print_fd, /* I - File descriptor to print */
• int copies, /* I - Copies to print */
• int argc, /* I - Number of command-line arguments (6 or 7) */
• char argv[]) / I - Command-line arguments */ +{
• int result;
• for(;;)
• {
• result = print_device_unix(uri, hostname, resource, options, print_fd,
• copies, argc, argv);
• if (result == -1)
• {
• result = print_device_libusb(uri, hostname, resource, options, print_fd,
• copies, argc, argv);
• if (result == -1)
• sleep(5);
• else
• return(result);
• }
• else
• return(result);
• } +} + +/*
• * 'list_devices()' - List all USB devices.
• */ + +void +list_devices(void) +{
• /* Try both discovery methods, each device will appear only under one
• of them */
• list_devices_libusb();
• list_devices_unix(); +} + + +/*
• * End of "$Id: usb-hybrid.c 8807 2009-08-31 18:45:43Z mike $".
• / --- backend/usb-libusb.c.orig 2009-09-29 14:06:05.000000000 +0200 +++ backend/usb-libusb.c 2009-09-30 10:40:43.000000000 +0200 @@ -13,16 +13,16 @@
  • Contents:
• * list_devices() - List the available printers.
• * print_device() - Print a file to a USB device.
• * list_devices_libusb() - List the available printers.
• * print_device_libusb() - Print a file to a USB device.
  • close_device() - Close the connection to the USB printer.
  • find_device() - Find or enumerate USB printers.
  • get_device_id() - Get the IEEE-1284 device ID for the printer.
  • list_cb() - List USB printers for discovery.
  • make_device_uri() - Create a device URI for a USB printer.
• * open_device() - Open a connection to the USB printer.
• * open_device_libusb() - Open a connection to the USB printer.
  • print_cb() - Find a USB printer for printing.
• * side_cb() - Handle side-channel requests.
• • side_cb_libusb() - Handle side-channel requests. */

  / @@ -65,30 +65,30 @@ static char make_device_uri(usb_printer_t printer, const char device_id, char uri, size_t uri_size); -static int open_device(usb_printer_t printer, int verbose); +static int open_device_libusb(usb_printer_t printer, int verbose); static int print_cb(usb_printer_t printer, const char device_uri, const char device_id, const void data); -static ssize_t side_cb(usb_printer_t printer, int print_fd); +static ssize_t side_cb_libusb(usb_printer_t *printer, int print_fd);

  /*

• * 'list_devices()' - List the available printers.
• • 'list_devices_libusb()' - List the available printers. */

  void -list_devices(void) +list_devices_libusb(void) {

• fputs("DEBUG: list_devices\n", stderr);

• fputs("DEBUG: list_devices_libusb\n", stderr); find_device(list_cb, NULL); }

  /*

• * 'print_device()' - Print a file to a USB device.
• • 'print_device_libusb()' - Print a file to a USB device. */

  int /* O - Exit status _/ -printdevice(const char *uri, / I - Device URI _/ +print_devicelibusb(const char *uri, / I - Device URI / const char *hostname, / I - Hostname/manufacturer / const char *resource, / I - Resource/modelname / char *options, / I - Device options/serial number / @@ -105,19 +105,23 @@ struct pollfd pfds[2]; / Poll descriptors */

• fputs("DEBUG: print_device\n", stderr);

• fputs("DEBUG: print_device_libusb\n", stderr);

  /*

  • Connect to the printer... */

+#if defined(linux) || defined(sun) || defined(FreeBSD) || defined(NetBSD) || defined(OpenBSD) || defined(DragonFly) || defined(FreeBSD_kernel)

• if ((printer = find_device(print_cb, uri)) == NULL)

• return(-1); +#else while ((printer = find_device(print_cb, uri)) == NULL) { cupsLangPuts(stderr, ("INFO: Waiting for printer to become available...\n")); sleep(5);

  }

  +#endif

  /*

  • If we are printing data from a print driver on stdin, ignore SIGTERM @@ -189,7 +193,7 @@

  if (pfds[1].revents & (POLLIN | POLLHUP)) {

• if ((bytes = side_cb(printer, print_fd)) < 0)

•  if ((bytes = side_cb_libusb(printer, print_fd)) < 0)

  pfds[1].events = 0; /* Filter has gone away... */ else tbytes += bytes; @@ -359,12 +363,13 @@ printer.iface = iface; printer.handle = NULL;

•      if (!open_device(&printer, data != NULL))

• if (!open_device_libusb(&printer, data != NULL)) { if (!get_device_id(&printer, device_id, sizeof(device_id))) { make_device_uri(&printer, device_id, device_uri, sizeof(device_uri));

• fprintf(stderr, "XXX 1 |%s|\n", device_uri);
  
    if ((*cb)(&printer, device_uri, device_id, data))
  {

  @@ -583,6 +588,14 @@ mfg = tempmfg; }

• if (!strncasecmp(mdl, mfg, strlen(mfg)))
• {
• mdl += strlen(mfg); +
• while (isspace(*mdl & 255))
• mdl ++;

• } + /*

  • Generate the device URI from the manufacturer, model, serial number,
  • and interface number... @@ -611,11 +624,11 @@

  /*

• * 'open_device()' - Open a connection to the USB printer.
• • 'open_device_libusb()' - Open a connection to the USB printer. */

  static int /* O - 0 on success, -1 on error _/ -open_device(usb_printert *printer, / I - Printer _/ +open_device_libusb(usb_printert *printer, / I - Printer / int verbose) / I - Update connecting-to-device state? / { int number; / Configuration/interface/altset numbers _/ @@ -733,16 +746,54 @@ const char deviceid, / I - IEEE-1284 device ID _/ const void data) /_ I - User data (make, model, S/N) */ {

• return (!strcmp((char *)data, device_uri));
• char uri = (char )data,
• *str1,
• *str2,
• buf[255]; +
• /*
• * libusb-discovered URIs can have an "interface" specification and this
• * never happens for usblp-discovered URIs, so remove the "interface"
• * specification from the URI which we are checking currently. This way a
• * queue for a usblp-discovered printer can now be accessed via libusb
• */
• if (((str1 = strstr(uri, "interface=")) == NULL) &&
• ((str2 = strstr(device_uri, "interface=")) != NULL))
• {
• *(str2 - 1) = '\0';
• } +
• /*
• * libusb-discovered URIs can have a "serial" specification when the
• * usblp-discovered URI for the same printer does not have one, as
• * with libusb we can discover serial numbers also with other methods
• * than only via the device ID. Therefore we accept also a
• * usblp-discovered printer without serial number as a match. This we
• * do by removing the serial number from the queue's (libusb-discovered)
• * URI before comparing. Also warn the user because of the incapability
• * of the usblp-based access to distinguish printers by the serial
• * number.
• */
• if (((str1 = strstr(uri, "serial=")) == NULL) &&
• ((str2 = strstr(device_uri, "serial=")) != NULL))
• {
• *(str2 - 1) = '\0';
• if (backendGetMakeModel(device_id, buf, sizeof(buf)) == 0)
• fprintf(stderr, "WARNING: If you have more than one %s printer connected to this machine, please make sure that the \"usblp\" kernel module is always unloaded (and blacklisted) and re-create the queues for these printers. Otherwise CUPS will not be able to distinguish them.\n",
• buf);
• } +
• fprintf(stderr, "XXX L |%s|%s|\n", uri, device_uri);

• return (!strcmp(uri, device_uri)); }

  /*

• * 'side_cb()' - Handle side-channel requests.
• • 'side_cb_libusb()' - Handle side-channel requests. */

  static ssizet /* O - Number of bytes written / -side_cb(usb_printert *printer, / I - Printer _/ +side_cb_libusb(usb_printert *printer, / I - Printer _/ int printfd) / I - File to print _/ { ssizet bytes, / Bytes read/written / --- backend/usb-unix.c.orig 2009-09-29 14:06:25.000000000 +0200 +++ backend/usb-unix.c 2009-09-30 10:35:23.000000000 +0200 @@ -18,10 +18,10 @@

  • Contents:
• * print_device() - Print a file to a USB device.
• * list_devices() - List all USB devices.
• * open_device() - Open a USB device...
• * side_cb() - Handle side-channel requests...
• * print_device_unix() - Print a file to a USB device.
• * list_devices_unix() - List all USB devices.
• * open_device_unix() - Open a USB device...
• • side_cb_unix() - Handle side-channel requests... */

  /* @@ -35,17 +35,17 @@

  • Local functions... */

-static int open_device(const char uri, int use_bc); -static int side_cb(int print_fd, int device_fd, int snmp_fd, +static int open_device_unix(const char uri, int use_bc); +static int side_cb_unix(int print_fd, int device_fd, int snmp_fd, http_addr_t *addr, int use_bc);

/*

• * 'print_device()' - Print a file to a USB device.
• • 'print_device_unix()' - Print a file to a USB device. */

  int /* O - Exit status _/ -printdevice(const char *uri, / I - Device URI _/ +print_deviceunix(const char *uri, / I - Device URI / const char *hostname, / I - Hostname/manufacturer / const char *resource, / I - Resource/modelname / char *options, / I - Device options/serial number _/ @@ -102,7 +102,7 @@ strncasecmp(hostname, "Minolta", 7);

  endif /_ FreeBSD || NetBSD || OpenBSD || DragonFly */

• if ((device_fd = open_device(uri, &use_bc)) == -1)
• if ((device_fd = open_device_unix(uri, &usebc)) == -1) { if (getenv("CLASS") != NULL) { @@ -132,6 +132,10 @@ ("INFO: Printer busy; will retry in 10 seconds...\n")); sleep(10); } +#ifdef HAVE_USB_H
• else

• return (-1); +#else else if (errno == ENXIO || errno == EIO || errno == ENOENT || errno == ENODEV) { @@ -147,6 +151,7 @@ resource, strerror(errno)); return (CUPS_BACKEND_FAILED); } +#endif } } while (device_fd < 0); @@ -190,7 +195,7 @@ tbytes = backendRunLoop(print_fd, device_fd, -1, NULL, use_bc, NULL);

  else

• tbytes = backendRunLoop(print_fd, device_fd, -1, NULL, use_bc, side_cb);

• tbytes = backendRunLoop(print_fd, device_fd, -1, NULL, use_bc, side_cb_unix);

  endif /* __sun */

  if (print_fd != 0 && tbytes >= 0) @@ -214,11 +219,11 @@

  /*

• * 'list_devices()' - List all USB devices.
• • 'list_devices_unix()' - List all USB devices. */

  void -list_devices(void) +list_devices_unix(void) {

  ifdef __linux

  int i; /* Looping var */ @@ -320,11 +325,11 @@

  /*

• * 'open_device()' - Open a USB device...
• • 'open_device_unix()' - Open a USB device... */

  static int /* O - File descriptor or -1 on error _/ -opendevice(const char *uri, / I - Device URI _/ +open_deviceunix(const char *uri, / I - Device URI _/ int usebc) / O - Set to 0 for unidirectional / { int fd; / File descriptor / @@ -357,8 +362,21 @@ char device[255], / Device filename _/ deviceid[1024], / Device ID string _/ makemodel[1024], / Make and model /

• device_uri[1024]; /* Device URI string */
• device_uri[1024], /* Device URI string */
• *str1,

• *str2;

• / +` \ libusb-discovered URIs can have an "interface" specification and this
• * never happens for usblp-discovered URIs, so remove the "interface"
• * specification from the URI of the print queue. This way a queue for
• * a libusb-discovered printer can now be accessed via the usblip kernel
• * module
• */
• if ((str1 = strstr(uri, "interface=")) != NULL)
• {
• *(str1 - 1) = '\0';

• }

  /*

  • Find the correct USB device... @@ -407,6 +425,26 @@ device_uri[0] = '\0'; }
• /*
• * libusb-discovered URIs can have a "serial" specification when the
• * usblp-discovered URI for the same printer does not have one, as
• * with libusb we can discover serial numbers also with other methods
• * than only via the device ID. Therefore we accept also a
• * usblp-discovered printer without serial number as a match. This we
• * do by removing the serial number from the queue's (libusb-discovered)
• * URI before comparing. Also warn the user because of the incapability
• * of the usblp-based access to distinguish printers by the serial
• * number.
• */
• if (((str1 = strstr(uri, "serial=")) != NULL) &&
• ((str2 = strstr(device_uri, "serial=")) == NULL))
• {
• *(str1 - 1) = '\0';
• fprintf(stderr, "WARNING: If you have more than one %s printer connected to this machine, please unload (and blacklist) the \"usblp\" kernel module as otherwise CUPS will not be able to distinguish your printers.\n",
• make_model);
• } +

• fprintf(stderr, "XXX U |%s|%s|\n", uri, device_uri); if (!strcmp(uri, device_uri)) { / @@ -433,10 +471,14 @@ /

  if (busy)

• {

  cupsLangPuts(stderr, ("INFO: Printer busy; will retry in 5 seconds...\n"));

• sleep(5);

• sleep(5);
• }
• else

• return -1; } }

  elif defined(__sun) && defined(ECPPIOC_GETDEVID)

  @@ -557,11 +599,11 @@

  /*

• * 'side_cb()' - Handle side-channel requests...
• * 'side_cb_unix()' - Handle side-channel requests... */

-static void -side_cb(int printfd, /* I - Print file / +static int +side_cb_unix(int printfd, / I - Print file _/ int devicefd, / I - Device file _/ int snmpfd, / I - SNMP socket (unused) _/ http_addrt *addr, / I - Device address (unused) / --- backend/usb.c.orig 2008-06-24 03:28:36.000000000 +0200 +++ backend/usb.c 2009-09-29 14:21:51.000000000 +0200 @@ -56,7 +56,7 @@ /

ifdef HAVE_USB_H

-# include "usb-libusb.c" +# include "usb-hybrid.c"

elif defined(APPLE)

include "usb-darwin.c"

elif defined(linux) || defined(sun) || defined(FreeBSD) || defined(NetBSD) || defined(OpenBSD) || defined(DragonFly) || defined(FreeBSD_kernel)

[michaelrsweet]

"usb-backend-both-usblp-and-libusb-2.diff":

diff -up -rN cups-1.4.3.orig/backend/Makefile cups-1.4.3/backend/Makefile --- cups-1.4.3.orig/backend/Makefile 2010-06-09 20:58:19.641591399 +1200 +++ cups-1.4.3/backend/Makefile 2010-06-09 20:51:06.025595868 +1200 @@ -267,7 +267,7 @@ usb: usb.o ../cups/$(LIBCUPS) libbackend echo Linking $@... $(CC) $(LDFLAGS) -o usb usb.o libbackend.a $(LIBUSB) \ $(BACKLIBS) $(LIBS) -usb.o: usb.c usb-darwin.c usb-libusb.c usb-unix.c +usb.o: usb.c usb-darwin.c usb-hybrid.c usb-libusb.c usb-unix.c

# diff -up -rN cups-1.4.3.orig/backend/ieee1284.c cups-1.4.3/backend/ieee1284.c --- cups-1.4.3.orig/backend/ieee1284.c 2009-12-08 15:13:42.000000000 +1300 +++ cups-1.4.3/backend/ieee1284.c 2010-06-09 20:51:06.357598941 +1200 @@ -255,6 +255,7 @@ backendGetDeviceID( cups_option_t values; / Keys and values in device ID / const char *mfg, / Manufacturer / *mdl, / Model */

• des, / Description / *sern; / Serial number / char temp[256], / Temporary manufacturer string / *tempptr; / Pointer into temp string */ @@ -285,10 +286,20 @@ backendGetDeviceID( } else {
• strlcpy(temp, make_model, sizeof(temp));
• /*
• * No manufacturer? Use the model string or description...
• */ +
• if (mdl)
• _ppdNormalizeMakeAndModel(mdl, temp, sizeof(temp));
• else if ((des = cupsGetOption("DESCRIPTION", num_values, values)) != NULL ||
• (des = cupsGetOption("DES", num_values, values)) != NULL)
• _ppdNormalizeMakeAndModel(des, temp, sizeof(temp));
• else

• strlcpy(temp, "Unknown", sizeof(temp));

  if ((tempptr = strchr(temp, ' ')) != NULL)

• *tempptr = '\0';

• *tempptr = '\0';

  mfg = temp; } diff -up -rN cups-1.4.3.orig/backend/usb-hybrid.c cups-1.4.3/backend/usb-hybrid.c --- cups-1.4.3.orig/backend/usb-hybrid.c 1970-01-01 12:00:00.000000000 +1200 +++ cups-1.4.3/backend/usb-hybrid.c 2010-06-09 20:51:06.441597823 +1200 @@ -0,0 +1,88 @@ +/*

• * "Id: usb-hybrid.c 8807 2009-08-31 18:45:43Z mike "
• *
• * USB port backend for the Common UNIX Printing System (CUPS).
• *
• * This file is included from "usb.c" when compiled on Linux.
• *
• * Copyright 2007-2008 by Apple Inc.
• * Copyright 1997-2007 by Easy Software Products, all rights reserved.
• *
• * These coded instructions, statements, and computer programs are the
• * property of Apple Inc. and are protected by Federal copyright
• * law. Distribution and use rights are outlined in the file "LICENSE.txt"
• * "LICENSE" which should have been included with this file. If this
• * file is missing or damaged, see the license at "http://www.cups.org/".
• *
• * This file is subject to the Apple OS-Developed Software exception.
• *
• * Contents:
• *
• * print_device() - Print a file to a USB device.
• * list_devices() - List all USB devices.
• / + +/
• * Include necessary headers.
• / + +#include <sys/select.h> + +/
• * Include the two USB implementations used under Linux ...
• _/ + +#define USBHYBRID 1 +#include "usb-libusb.c" +#include "usb-unix.c" + +/
• * 'print_device()' - Print a file to a USB device.
• / + +int / O - Exit status _/ +printdevice(const char *uri, / I - Device URI */
• const char hostname, / I - Hostname/manufacturer */
• const char resource, / I - Resource/modelname */
• char options, / I - Device options/serial number */
• int print_fd, /* I - File descriptor to print */
• int copies, /* I - Copies to print */
• int argc, /* I - Number of command-line arguments (6 or 7) */
• char argv[]) / I - Command-line arguments */ +{
• int result;
• for(;;)
• {
• result = print_device_unix(uri, hostname, resource, options, print_fd,
• copies, argc, argv);
• if (result == -1)
• {
• result = print_device_libusb(uri, hostname, resource, options, print_fd,
• copies, argc, argv);
• if (result == -1)
• sleep(5);
• else
• return(result);
• }
• else
• return(result);
• } +} + +/*
• * 'list_devices()' - List all USB devices.
• */ + +void +list_devices(void) +{
• /* Try both discovery methods, each device will appear only under one
• of them */
• list_devices_libusb();
• list_devices_unix(); +} + + +/*
• * End of "Id: usb-hybrid.c 8807 2009-08-31 18:45:43Z mike ".
• / diff -up -rN cups-1.4.3.orig/backend/usb-libusb.c cups-1.4.3/backend/usb-libusb.c --- cups-1.4.3.orig/backend/usb-libusb.c 2009-09-12 08:03:31.000000000 +1200 +++ cups-1.4.3/backend/usb-libusb.c 2010-06-09 20:51:06.533598662 +1200 @@ -13,16 +13,16 @@
  • Contents:
• * list_devices() - List the available printers.
• * print_device() - Print a file to a USB device.
• * list_devices_libusb() - List the available printers.
• * print_device_libusb() - Print a file to a USB device.
  • close_device() - Close the connection to the USB printer.
  • find_device() - Find or enumerate USB printers.
  • get_device_id() - Get the IEEE-1284 device ID for the printer.
  • list_cb() - List USB printers for discovery.
  • make_device_uri() - Create a device URI for a USB printer.
• * open_device() - Open a connection to the USB printer.
• * open_device_libusb() - Open a connection to the USB printer.
  • print_cb() - Find a USB printer for printing.
• * side_cb() - Handle side-channel requests.
• • side_cb_libusb() - Handle side-channel requests. */

  / @@ -65,30 +65,30 @@ static int list_cb(usb_printer_t print static char make_device_uri(usb_printer_t printer, const char device_id, char uri, size_t uri_size); -static int open_device(usb_printer_t printer, int verbose); +static int open_device_libusb(usb_printer_t printer, int verbose); static int print_cb(usb_printer_t printer, const char device_uri, const char device_id, const void data); -static ssize_t side_cb(usb_printer_t printer, int print_fd); +static ssize_t side_cb_libusb(usb_printer_t printer, int print_fd);

  /*

• * 'list_devices()' - List the available printers.
• • 'list_devices_libusb()' - List the available printers. */

  void -list_devices(void) +list_devices_libusb(void) {

• fputs("DEBUG: list_devices\n", stderr);

• fputs("DEBUG: list_devices_libusb\n", stderr); find_device(list_cb, NULL); }

  /*

• * 'print_device()' - Print a file to a USB device.
• • 'print_device_libusb()' - Print a file to a USB device. */

  int /* O - Exit status _/ -printdevice(const char *uri, / I - Device URI _/ +print_devicelibusb(const char *uri, / I - Device URI / const char *hostname, / I - Hostname/manufacturer / const char *resource, / I - Resource/modelname / char *options, / I - Device options/serial number _/ @@ -105,19 +105,23 @@ printdevice(const char *uri, / I - De struct pollfd pfds[2]; /* Poll descriptors */

• fputs("DEBUG: print_device\n", stderr);

• fputs("DEBUG: print_device_libusb\n", stderr);

  /*

  • Connect to the printer... */

+#if defined(linux) || defined(sun) || defined(FreeBSD) || defined(NetBSD) || defined(OpenBSD) || defined(DragonFly) || defined(FreeBSD_kernel)

• if ((printer = find_device(print_cb, uri)) == NULL)

• return(-1); +#else while ((printer = find_device(print_cb, uri)) == NULL) { cupsLangPuts(stderr, ("INFO: Waiting for printer to become available...\n")); sleep(5);

  }

  +#endif

  /*

  • If we are printing data from a print driver on stdin, ignore SIGTERM @@ -189,7 +193,7 @@ print_device(const char uri, / I - De

  if (pfds[1].revents & (POLLIN | POLLHUP)) {

• if ((bytes = side_cb(printer, print_fd)) < 0)

•  if ((bytes = side_cb_libusb(printer, print_fd)) < 0)

  pfds[1].events = 0; /* Filter has gone away... _/ else tbytes += bytes; @@ -359,7 +363,7 @@ find_device(usb_cbt cb, / I - Callb printer.iface = iface; printer.handle = NULL;

•      if (!open_device(&printer, data != NULL))

•      if (!open_device_libusb(&printer, data != NULL))
  {
  if (!get_device_id(&printer, device_id, sizeof(device_id)))
  {

  @@ -583,6 +587,14 @@ make_device_uri( mfg = tempmfg; }

• if (!strncasecmp(mdl, mfg, strlen(mfg)))
• {
• mdl += strlen(mfg); +
• while (isspace(*mdl & 255))
• mdl ++;

• } + /*

  • Generate the device URI from the manufacturer, model, serial number,
  • and interface number... @@ -611,11 +623,11 @@ make_device_uri(

  /*

• * 'open_device()' - Open a connection to the USB printer.
• • 'open_device_libusb()' - Open a connection to the USB printer. */

  static int /* O - 0 on success, -1 on error _/ -open_device(usb_printert *printer, / I - Printer _/ +open_device_libusb(usb_printert *printer, / I - Printer / int verbose) / I - Update connecting-to-device state? / { int number; / Configuration/interface/altset numbers _/ @@ -733,16 +745,73 @@ print_cb(usb_printert *printer, / I - const char _deviceid, / I - IEEE-1284 device ID / const void *data) / I - User data (make, model, S/N) */ {

• return (!strcmp((char *)data, device_uri));
• char uri = (char )data,
• *str1,
• *str2,
• buf[255],
• requested_uri[1024]; +
• /* Work on a copy of uri */
• strncpy(requested_uri, uri, sizeof(requested_uri));
• requested_uri[sizeof(requested_uri) - 1] = '\0'; +
• /*
• * libusb-discovered URIs can have an "interface" specification and this
• * never happens for usblp-discovered URIs, so remove the "interface"
• * specification from the URI which we are checking currently. This way a
• * queue for a usblp-discovered printer can now be accessed via libusb
• */
• if (((str1 = strstr(requested_uri, "interface=")) == NULL) &&
• ((str2 = strstr(device_uri, "interface=")) != NULL))
• {
• *(str2 - 1) = '\0';
• } +
• /*
• * Old URI with "serial=?". Cut this part off and consider this as
• * an URI without serial number
• */
• if ((str1 = strstr(requested_uri, "serial=?")) != NULL)
• *(str1 - 1) = '\0'; +
• /*
• * Old URI without serial number. Match it also with URIs with serial
• * number
• */
• if (((str1 = strstr(requested_uri, "serial=")) == NULL) &&
• ((str2 = strstr(device_uri, "serial=")) != NULL))
• *(str2 - 1) = '\0'; +
• /*
• * libusb-discovered URIs can have a "serial" specification when the
• * usblp-discovered URI for the same printer does not have one, as
• * with libusb we can discover serial numbers also with other methods
• * than only via the device ID. Therefore we accept also a
• * usblp-discovered printer without serial number as a match. This we
• * do by removing the serial number from the queue's (libusb-discovered)
• * URI before comparing. Also warn the user because of the incapability
• * of the usblp-based access to distinguish printers by the serial
• * number.
• */
• if (((str1 = strstr(requested_uri, "serial=")) == NULL) &&
• ((str2 = strstr(device_uri, "serial=")) != NULL))
• {
• *(str2 - 1) = '\0';
• if (backendGetMakeModel(device_id, buf, sizeof(buf)) == 0)
• fprintf(stderr, "WARNING: If you have more than one %s printer connected to this machine, please make sure that the \"usblp\" kernel module is always unloaded (and blacklisted) and re-create the queues for these printers. Otherwise CUPS will not be able to distinguish them.\n",
• buf);
• } +

• return (!strcmp(requested_uri, device_uri)); }

  /*

• * 'side_cb()' - Handle side-channel requests.
• • 'side_cb_libusb()' - Handle side-channel requests. */

  static ssizet /* O - Number of bytes written / -side_cb(usb_printert *printer, / I - Printer _/ +side_cb_libusb(usb_printert *printer, / I - Printer _/ int printfd) / I - File to print _/ { ssizet bytes, / Bytes read/written / diff -up -rN cups-1.4.3.orig/backend/usb-unix.c cups-1.4.3/backend/usb-unix.c --- cups-1.4.3.orig/backend/usb-unix.c 2009-12-08 15:13:42.000000000 +1300 +++ cups-1.4.3/backend/usb-unix.c 2010-06-09 20:51:06.613600058 +1200 @@ -25,6 +25,16 @@ /

  /*

• * If USB_HYBRID is define append "_unix" to functions.
• _/ +#ifdef USB_HYBRID +# define print_device print_device_unix +# define list_devices list_devices_unix +# define open_device open_device_unix +# define side_cb side_cbunix +#endif + +/
  • Include necessary headers. */

@@ -132,6 +142,10 @@ print_device(const char uri, / I - De _("INFO: Printer busy; will retry in 10 seconds...\n")); sleep(10); } +#ifdef HAVE_USB_H

• else
• return (-1); +#else else if (errno == ENXIO || errno == EIO || errno == ENOENT || errno == ENODEV) { @@ -147,6 +161,7 @@ print_device(const char uri, / I - De resource, strerror(errno)); return (CUPS_BACKEND_FAILED); } +#endif } } while (device_fd < 0); @@ -357,8 +372,10 @@ open_device(const char uri, / I - Dev char device[255], /* Device filename _/ deviceid[1024], / Device ID string _/ makemodel[1024], / Make and model */

- device_uri[1024]; /* Device URI string */

• device_uri[1024], /* Device URI string */
• requested_uri[1024], /* Device URI string */
• *str1,

• *str2;

  /*

  • Find the correct USB device... @@ -407,7 +424,55 @@ open_device(const char uri, / I - Dev device_uri[0] = '\0'; }

•  if (!strcmp(uri, device_uri))

• /* Work on a copy of uri */
• strncpy(requested_uri, uri, sizeof(requested_uri));
• requested_uri[sizeof(requested_uri) - 1] = '\0'; +
• /*
• * libusb-discovered URIs can have an "interface" specification and this
• * never happens for usblp-discovered URIs, so remove the "interface"
• * specification from the URI of the print queue. This way a queue for
• * a libusb-discovered printer can now be accessed via the usblip kernel
• * module
• */
• if ((str1 = strstr(requested_uri, "interface=")) != NULL)
• *(str1 - 1) = '\0'; +
• /*
• * Old URI with "serial=?". Cut this part off and consider this as
• * an URI without serial number
• */
• if ((str1 = strstr(requested_uri, "serial=?")) != NULL)
• *(str1 - 1) = '\0'; +
• /*
• * Old URI without serial number. Match it also with URIs with serial
• * number
• */
• if (((str1 = strstr(requested_uri, "serial=")) == NULL) &&
• ((str2 = strstr(device_uri, "serial=")) != NULL))
• *(str2 - 1) = '\0'; +
• /*
• * libusb-discovered URIs can have a "serial" specification when the
• * usblp-discovered URI for the same printer does not have one, as
• * with libusb we can discover serial numbers also with other methods
• * than only via the device ID. Therefore we accept also a
• * usblp-discovered printer without serial number as a match. This we
• * do by removing the serial number from the queue's (libusb-discovered)
• * URI before comparing. Also warn the user because of the incapability
• * of the usblp-based access to distinguish printers by the serial
• * number.
• */
• if (((str1 = strstr(requested_uri, "serial=")) != NULL) &&
• ((str2 = strstr(device_uri, "serial=")) == NULL))
• {
• *(str1 - 1) = '\0';
• fprintf(stderr, "WARNING: If you have more than one %s printer connected to this machine, please unload (and blacklist) the \"usblp\" kernel module as otherwise CUPS will not be able to distinguish your printers.\n",
• make_model);
• } +

•  if (!strcmp(requested_uri, device_uri))

  { /*

  • Yes, return this file descriptor... @@ -433,10 +498,14 @@ open_device(const char uri, / I - Dev */

  if (busy)

• {

  cupsLangPuts(stderr, ("INFO: Printer busy; will retry in 5 seconds...\n"));

• sleep(5);

• sleep(5);
• }
• else
• return -1; } }

  elif defined(__sun) && defined(ECPPIOC_GETDEVID)

  @@ -625,6 +694,10 @@ side_cb(int print_fd, /* I - Pr return (cupsSideChannelWrite(command, status, data, datalen, 1.0)); }

+#undef print_device +#undef list_devices +#undef open_device +#undef side_cb

/*

• End of "$Id: usb-unix.c 8912 2009-12-08 02:13:42Z mike $". diff -up -rN cups-1.4.3.orig/backend/usb.c cups-1.4.3/backend/usb.c --- cups-1.4.3.orig/backend/usb.c 2008-06-24 13:28:36.000000000 +1200 +++ cups-1.4.3/backend/usb.c 2010-06-09 20:51:06.801599220 +1200 @@ -56,7 +56,7 @@ int print_device(const char uri, const /

  ifdef HAVE_USB_H

  -# include "usb-libusb.c" +# include "usb-hybrid.c"

  elif defined(APPLE)

  include "usb-darwin.c"

  elif defined(linux) || defined(sun) || defined(FreeBSD) || defined(NetBSD) || defined(OpenBSD) || defined(DragonFly) || defined(FreeBSD_kernel)