libburnia
/
libburn
2
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
libburn/libburn/sg-linux.c

1105 lines
30 KiB
C
Raw Blame History

/* -*- indent-tabs-mode: t; tab-width: 8; c-basic-offset: 8; -*- */
/*
This is the main operating system dependent SCSI part of libburn. It implements
the transport level aspects of SCSI control and command i/o.
Present implementation: Linux SCSI Generic (sg)
PORTING:
Porting libburn typically will consist of adding a new operating system case
to the following switcher files:
os.h Operating system specific libburn definitions and declarations.
sg.c Operating system dependent transport level modules.
and of deriving the following system specific files from existing examples:
os-*.h Included by os.h. You will need some general system knowledge
about signals and knowledge about the storage object needs of your
transport level module sg-*.c.
sg-*.c This source module. You will need special system knowledge about
how to detect all potentially available drives, how to open them,
eventually how to exclusively reserve them, how to perform
SCSI transactions, how to inquire the (pseudo-)SCSI driver.
You will not need to care about CD burning, MMC or other high-level
SCSI aspects.
Said sg-*.c operations are defined by a public function interface, which has
to be implemented in a way that provides libburn with the desired services:
sg_give_next_adr() iterates over the set of potentially useful drive
address strings.
scsi_enumerate_drives() brings all available, not-whitelist-banned, and
accessible drives into libburn's list of drives.
sg_drive_is_open() tells wether libburn has the given drive in use.
sg_grab() opens the drive for SCSI commands and ensures
undisturbed access.
sg_release() closes a drive opened by sg_grab()
sg_issue_command() sends a SCSI command to the drive, receives reply,
and evaluates wether the command succeeded or shall
be retried or finally failed.
sg_obtain_scsi_adr() tries to obtain SCSI address parameters.
Porting hints are marked by the text "PORTING:".
Send feedback to libburn-hackers@pykix.org .
Hint: You should also look into sg-freebsd-port.c, which is a younger and
in some aspects more straightforward implementation of this interface.
*/
/** PORTING : ------- OS dependent headers and definitions ------ */
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <string.h>
#include <sys/poll.h>
#include <linux/hdreg.h>
#include <stdlib.h>
#include <scsi/sg.h>
#include <scsi/scsi.h>
/* ts A61211 : to recognize CD devices on /dev/sr* */
#include <linux/cdrom.h>
/* ts A61211 : preparing for exploration of recent Linux ATA adventures */
/** PORTING : Device file families for bus scanning and drive access.
Both device families must support the following ioctls:
SG_IO,
SG_GET_SCSI_ID
SCSI_IOCTL_GET_BUS_NUMBER
SCSI_IOCTL_GET_IDLUN
as well as mutual exclusively locking with open(O_EXCL).
If a device family is left empty, then it will not be used.
To avoid misunderstandings: both families are used via identical
transport methods as soon as a device file is accepted as CD drive
by the family specific function <family>_enumerate().
One difference remains throughout usage: Host,Channel,Id,Lun and Bus
address parameters of ATA devices are considered invalid.
*/
/* Set this to 1 in order to get on stderr messages from sg_enumerate() */
static int linux_sg_enumerate_debug = 0;
/* The device file family to use for (emulated) generic SCSI transport.
This must be a printf formatter with one single placeholder for int
in the range of 0 to 31 . The resulting addresses must provide SCSI
address parameters Host, Channel, Id, Lun and also Bus.
E.g.: "/dev/sg%d"
*/
/* NEW INFO: If hard disks at /dev/sr allow ioctl(CDROM_DRIVE_STATUS), they
are in danger.
If you want it less dangerous:
#undef CDROM_DRIVE_STATUS
but then you might need linux_sg_accept_any_type = 1 which
is _more dangerous_.
*/
/* !!! DO NOT SET TO sr%d UNLESS YOU PROTECTED ALL INDISPENSIBLE DEVICES
by chmod -rw . A test wether non-CD devices are properly excluded would
be well needed though. Heroic disks, scanners, etc. wanted !!! */
static char linux_sg_device_family[80] = {"/dev/sg%d"};
/* Set this to 1 in order to accept any TYPE_* (see scsi/scsi.h) */
/* NEW INFO: Try with 0 first. There is hope via CDROM_DRIVE_STATUS. */
/* !!! DO NOT SET TO 1 UNLESS YOU PROTECTED ALL INDISPENSIBLE DEVICES
chmod -rw !!! */
static int linux_sg_accept_any_type = 0;
/* The device file family to use for SCSI transport over ATA.
This must be a printf formatter with one single placeholder for a
_single_ char in the range of 'a' to 'z'. This placeholder _must_ be
at the end of the formatter string.
E.g. "/dev/hd%c"
*/
static char linux_ata_device_family[80] = {"/dev/hd%c"};
/* Set this to 1 in order to get on stderr messages from ata_enumerate()
*/
static int linux_ata_enumerate_verbous = 0;
/** PORTING : ------ libburn portable headers and definitions ----- */
#include "transport.h"
#include "drive.h"
#include "sg.h"
#include "spc.h"
#include "mmc.h"
#include "sbc.h"
#include "debug.h"
#include "toc.h"
#include "util.h"
#include "libdax_msgs.h"
extern struct libdax_msgs *libdax_messenger;
/* ts A51221 */
int burn_drive_is_banned(char *device_address);
/* ------------------------------------------------------------------------ */
/* PORTING: Private definitions. Port only if needed by public functions. */
/* (Public functions are listed below) */
/* ------------------------------------------------------------------------ */
static void enumerate_common(char *fname, int bus_no, int host_no,
int channel_no, int target_no, int lun_no);
/* >>> ts A61115 : this needs mending. A Linux aspect shows up in cdrskin. */
/* ts A60813 : storage objects are in libburn/init.c
wether to use O_EXCL
wether to use O_NOBLOCK with open(2) on devices
wether to take O_EXCL rejection as fatal error */
extern int burn_sg_open_o_excl;
extern int burn_sg_open_o_nonblock;
extern int burn_sg_open_abort_busy;
/* ts A60821
<<< debug: for tracing calls which might use open drive fds */
int mmc_function_spy(char * text);
/* ------------------------------------------------------------------------ */
/* PORTING: Private functions. Port only if needed by public functions */
/* (Public functions are listed below) */
/* ------------------------------------------------------------------------ */
static int sgio_test(int fd)
{
unsigned char test_ops[] = { 0, 0, 0, 0, 0, 0 };
sg_io_hdr_t s;
memset(&s, 0, sizeof(sg_io_hdr_t));
s.interface_id = 'S';
s.dxfer_direction = SG_DXFER_NONE;
s.cmd_len = 6;
s.cmdp = test_ops;
s.timeout = 12345;
return ioctl(fd, SG_IO, &s);
}
/* ts A60924 */
static int sg_handle_busy_device(char *fname, int os_errno)
{
char msg[4096];
/* ts A60814 : i saw no way to do this more nicely */
if (burn_sg_open_abort_busy) {
fprintf(stderr,
"\nlibburn: FATAL : Application triggered abort on busy device '%s'\n",
fname);
/* ts A61007 */
abort();
/* a ssert("drive busy" == "non fatal"); */
}
/* ts A60924 : now reporting to libdax_msgs */
sprintf(msg, "Cannot open busy device '%s'", fname);
libdax_msgs_submit(libdax_messenger, -1, 0x00020001,
LIBDAX_MSGS_SEV_SORRY, LIBDAX_MSGS_PRIO_LOW,
msg, os_errno, 0);
return 1;
}
/* ts A60926 */
static int sg_open_drive_fd(char *fname, int scan_mode)
{
int open_mode = O_RDWR, fd;
char msg[81];
/* ts A60813 - A60927
O_EXCL with devices is a non-POSIX feature
of Linux kernels. Possibly introduced 2002.
Mentioned in "The Linux SCSI Generic (sg) HOWTO" */
if(burn_sg_open_o_excl)
open_mode |= O_EXCL;
/* ts A60813
O_NONBLOCK was already hardcoded in ata_ but not in sg_.
There must be some reason for this. So O_NONBLOCK is
default mode for both now. Disable on own risk. */
if(burn_sg_open_o_nonblock)
open_mode |= O_NONBLOCK;
/* <<< debugging
fprintf(stderr,
"\nlibburn: experimental: o_excl= %d , o_nonblock= %d, abort_on_busy= %d\n",
burn_sg_open_o_excl,burn_sg_open_o_nonblock,burn_sg_open_abort_busy);
fprintf(stderr,
"libburn: experimental: O_EXCL= %d , O_NONBLOCK= %d\n",
!!(open_mode&O_EXCL),!!(open_mode&O_NONBLOCK));
*/
fd = open(fname, open_mode);
if (fd == -1) {
/* <<< debugging
fprintf(stderr,
"\nlibburn: experimental: fname= %s , errno= %d\n",
fname,errno);
*/
if (errno == EBUSY) {
sg_handle_busy_device(fname, errno);
return -1;
}
if (scan_mode)
return -1;
sprintf(msg, "Failed to open device '%s'",fname);
libdax_msgs_submit(libdax_messenger, -1, 0x00020005,
LIBDAX_MSGS_SEV_FATAL, LIBDAX_MSGS_PRIO_HIGH,
msg, errno, 0);
return -1;
}
return fd;
}
/* ts A60925 : ticket 74 */
static int sg_close_drive_fd(char *fname, int driveno, int *fd, int sorry)
{
int ret, os_errno, sevno= LIBDAX_MSGS_SEV_DEBUG;
char msg[4096+100];
if(*fd < 0)
return(0);
ret = close(*fd);
*fd = -1337;
if(ret != -1)
return 1;
os_errno= errno;
if (fname != NULL)
sprintf(msg, "Encountered error when closing drive '%s'",
fname);
else
sprintf(msg, "Encountered error when closing drive");
if (sorry)
sevno = LIBDAX_MSGS_SEV_SORRY;
libdax_msgs_submit(libdax_messenger, driveno, 0x00020002,
sevno, LIBDAX_MSGS_PRIO_HIGH, msg, os_errno, 0);
return 0;
}
/* ts A60926 */
static int sg_release_siblings(int sibling_fds[], int *sibling_count)
{
int i;
char msg[81];
for(i= 0; i < *sibling_count; i++)
sg_close_drive_fd(NULL, -1, &(sibling_fds[i]), 0);
if(*sibling_count > 0) {
sprintf(msg, "Closed %d O_EXCL scsi siblings", *sibling_count);
libdax_msgs_submit(libdax_messenger, -1, 0x00020007,
LIBDAX_MSGS_SEV_NOTE, LIBDAX_MSGS_PRIO_HIGH, msg, 0,0);
}
*sibling_count = 0;
return 1;
}
/* ts A60926 */
static int sg_close_drive(struct burn_drive *d)
{
int ret;
if (!burn_drive_is_open(d))
return 0;
sg_release_siblings(d->sibling_fds, &(d->sibling_count));
ret = sg_close_drive_fd(d->devname, d->global_index, &(d->fd), 0);
return ret;
}
/* ts A60926 */
static int sg_open_scsi_siblings(char *path, int driveno,
int sibling_fds[], int *sibling_count,
int host_no, int channel_no, int id_no, int lun_no)
{
int tld, i, ret, fd, i_bus_no = -1;
int i_host_no = -1, i_channel_no = -1, i_target_no = -1, i_lun_no = -1;
char msg[161], fname[81];
static char tldev[][81]= {"/dev/sr%d", "/dev/scd%d", "/dev/st%d",
"/dev/sg%d", ""};
if (linux_sg_device_family[0] == 0)
return 1;
if(host_no < 0 || id_no < 0 || channel_no < 0 || lun_no < 0)
return(2);
if(*sibling_count > 0)
sg_release_siblings(sibling_fds, sibling_count);
for (tld = 0; tldev[tld][0] != 0; tld++) {
if (strcmp(tldev[tld], linux_sg_device_family)==0)
continue;
for (i = 0; i < 32; i++) {
sprintf(fname, tldev[tld], i);
ret = sg_obtain_scsi_adr(fname, &i_bus_no, &i_host_no,
&i_channel_no, &i_target_no, &i_lun_no);
if (ret <= 0)
continue;
if (i_host_no != host_no || i_channel_no != channel_no)
continue;
if (i_target_no != id_no || i_lun_no != lun_no)
continue;
fd = sg_open_drive_fd(fname, 0);
if (fd < 0)
goto failed;
if (*sibling_count>=LIBBURN_SG_MAX_SIBLINGS) {
sprintf(msg, "Too many scsi siblings of '%s'",
path);
libdax_msgs_submit(libdax_messenger,
driveno, 0x00020006,
LIBDAX_MSGS_SEV_FATAL,
LIBDAX_MSGS_PRIO_HIGH, msg, 0, 0);
goto failed;
}
sprintf(msg, "Opened O_EXCL scsi sibling '%s' of '%s'",
fname, path);
libdax_msgs_submit(libdax_messenger, driveno,
0x00020004,
LIBDAX_MSGS_SEV_NOTE, LIBDAX_MSGS_PRIO_HIGH,
msg, 0, 0);
sibling_fds[*sibling_count] = fd;
(*sibling_count)++;
}
}
return 1;
failed:;
sg_release_siblings(sibling_fds, sibling_count);
return 0;
}
/** Speciality of Linux: detect non-SCSI ATAPI (EIDE) which will from
then on used used via generic SCSI as is done with (emulated) SCSI drives */
static void ata_enumerate(void)
{
struct hd_driveid tm;
int i, fd;
char fname[10];
if (linux_ata_enumerate_verbous)
fprintf(stderr, "libburn_debug: linux_ata_device_family = %s\n",
linux_ata_device_family);
if (linux_ata_device_family[0] == 0)
return;
for (i = 0; i < 26; i++) {
sprintf(fname, linux_ata_device_family, 'a' + i);
if (linux_ata_enumerate_verbous)
fprintf(stderr, "libburn_debug: %s : ", fname);
/* ts A51221 */
if (burn_drive_is_banned(fname)) {
if (linux_ata_enumerate_verbous)
fprintf(stderr, "not in whitelist\n");
continue;
}
fd = sg_open_drive_fd(fname, 1);
if (fd == -1) {
if (linux_ata_enumerate_verbous)
fprintf(stderr,"open failed, errno=%d '%s'\n",
errno, strerror(errno));
continue;
}
/* found a drive */
ioctl(fd, HDIO_GET_IDENTITY, &tm);
/* not atapi */
if (!(tm.config & 0x8000) || (tm.config & 0x4000)) {
if (linux_ata_enumerate_verbous)
fprintf(stderr, "not marked as ATAPI\n");
sg_close_drive_fd(fname, -1, &fd, 0);
continue;
}
/* if SG_IO fails on an atapi device, we should stop trying to
use hd* devices */
if (sgio_test(fd) == -1) {
if (linux_ata_enumerate_verbous)
fprintf(stderr,
"FATAL: sgio_test() failed: errno=%d '%s'\n",
errno, strerror(errno));
sg_close_drive_fd(fname, -1, &fd, 0);
return;
}
if (sg_close_drive_fd(fname, -1, &fd, 1) <= 0) {
if (linux_ata_enumerate_verbous)
fprintf(stderr,
"cannot close properly, errno=%d '%s'\n",
errno, strerror(errno));
continue;
}
if (linux_ata_enumerate_verbous)
fprintf(stderr, "accepting as drive without SCSI address\n");
enumerate_common(fname, -1, -1, -1, -1, -1);
}
}
/** Detects (probably emulated) SCSI drives */
static void sg_enumerate(void)
{
struct sg_scsi_id sid;
int i, fd, sibling_fds[LIBBURN_SG_MAX_SIBLINGS], sibling_count= 0, ret;
int sid_ret = 0;
int bus_no= -1, host_no= -1, channel_no= -1, target_no= -1, lun_no= -1;
char fname[10];
if (linux_sg_enumerate_debug)
fprintf(stderr, "libburn_debug: linux_sg_device_family = %s\n",
linux_sg_device_family);
if (linux_sg_device_family[0] == 0)
return;
for (i = 0; i < 32; i++) {
sprintf(fname, linux_sg_device_family, i);
if (linux_sg_enumerate_debug)
fprintf(stderr, "libburn_debug: %s : ", fname);
/* ts A51221 */
if (burn_drive_is_banned(fname)) {
if (linux_sg_enumerate_debug)
fprintf(stderr, "not in whitelist\n");
continue;
}
/* ts A60927 */
fd = sg_open_drive_fd(fname, 1);
if (fd == -1) {
if (linux_sg_enumerate_debug)
fprintf(stderr, "open failed, errno=%d '%s'\n",
errno, strerror(errno));
continue;
}
/* found a drive */
sid_ret = ioctl(fd, SG_GET_SCSI_ID, &sid);
if (sid_ret == -1) {
sid.scsi_id = -1; /* mark SCSI address as invalid */
if(linux_sg_enumerate_debug)
fprintf(stderr,
"ioctl(SG_GET_SCSI_ID) failed, errno=%d '%s' , ",
errno, strerror(errno));
#ifdef CDROM_DRIVE_STATUS
/* ts A61211 : not widening old acceptance range */
if (strcmp(linux_sg_device_family,"/dev/sg%d") != 0) {
/* http://developer.osdl.org/dev/robustmutexes/
src/fusyn.hg/Documentation/ioctl/cdrom.txt */
sid_ret = ioctl(fd, CDROM_DRIVE_STATUS, 0);
if(linux_sg_enumerate_debug)
fprintf(stderr,
"ioctl(CDROM_DRIVE_STATUS) = %d , ",
sid_ret);
if (sid_ret != -1 && sid_ret != CDS_NO_INFO)
sid.scsi_type = TYPE_ROM;
else
sid_ret = -1;
}
#endif /* CDROM_DRIVE_STATUS */
}
#ifdef SCSI_IOCTL_GET_BUS_NUMBER
/* Hearsay A61005 */
if (ioctl(fd, SCSI_IOCTL_GET_BUS_NUMBER, &bus_no) == -1)
bus_no = -1;
#endif
if (sg_close_drive_fd(fname, -1, &fd,
sid.scsi_type == TYPE_ROM ) <= 0) {
if (linux_sg_enumerate_debug)
fprintf(stderr,
"cannot close properly, errno=%d '%s'\n",
errno, strerror(errno));
continue;
}
if ( (sid_ret == -1 || sid.scsi_type != TYPE_ROM)
&& !linux_sg_accept_any_type) {
if (linux_sg_enumerate_debug)
fprintf(stderr, "sid.scsi_type = %d (!= TYPE_ROM)\n",
sid.scsi_type);
continue;
}
if (sid_ret == -1 || sid.scsi_id < 0) {
/* ts A61211 : employ a more general ioctl */
ret = sg_obtain_scsi_adr(fname, &bus_no, &host_no,
&channel_no, &target_no, &lun_no);
if (ret>0) {
sid.host_no = host_no;
sid.channel = channel_no;
sid.scsi_id = target_no;
sid.lun = lun_no;
} else {
if (linux_sg_enumerate_debug)
fprintf(stderr,
"sg_obtain_scsi_adr() failed\n");
continue;
}
}
/* ts A60927 : trying to do locking with growisofs */
if(burn_sg_open_o_excl>1) {
ret = sg_open_scsi_siblings(
fname, -1, sibling_fds, &sibling_count,
sid.host_no, sid.channel,
sid.scsi_id, sid.lun);
if (ret<=0) {
if (linux_sg_enumerate_debug)
fprintf(stderr, "cannot lock siblings\n");
sg_handle_busy_device(fname, 0);
continue;
}
/* the final occupation will be done in sg_grab() */
sg_release_siblings(sibling_fds, &sibling_count);
}
#ifdef SCSI_IOCTL_GET_BUS_NUMBER
if(bus_no == -1)
bus_no = 1000 * (sid.host_no + 1) + sid.channel;
#else
bus_no = sid.host_no;
#endif
if (linux_sg_enumerate_debug)
fprintf(stderr, "accepting as SCSI %d,%d,%d,%d bus=%d\n",
sid.host_no, sid.channel, sid.scsi_id, sid.lun,
bus_no);
enumerate_common(fname, bus_no, sid.host_no, sid.channel,
sid.scsi_id, sid.lun);
}
}
/* ts A61115 */
/* ----------------------------------------------------------------------- */
/* PORTING: Private functions which contain publicly needed functionality. */
/* Their portable part must be performed. So it is probably best */
/* to replace the non-portable part and to call these functions */
/* in your port, too. */
/* ----------------------------------------------------------------------- */
/** Wraps a detected drive into libburn structures and hands it over to
libburn drive list.
*/
/* ts A60923 - A61005 : introduced new SCSI parameters */
/* ts A61021 : moved non os-specific code to spc,sbc,mmc,drive */
static void enumerate_common(char *fname, int bus_no, int host_no,
int channel_no, int target_no, int lun_no)
{
int ret, i;
struct burn_drive out;
/* General libburn drive setup */
burn_setup_drive(&out, fname);
/* This transport adapter uses SCSI-family commands and models
(seems the adapter would know better than its boss, if ever) */
ret = burn_scsi_setup_drive(&out, bus_no, host_no, channel_no,
target_no, lun_no, 0);
if (ret<=0)
return;
/* PORTING: ------------------- non portable part --------------- */
/* Operating system adapter is Linux Generic SCSI (sg) */
/* Adapter specific handles and data */
out.fd = -1337;
out.sibling_count = 0;
for(i= 0; i<LIBBURN_SG_MAX_SIBLINGS; i++)
out.sibling_fds[i] = -1337;
/* PORTING: ---------------- end of non portable part ------------ */
/* Adapter specific functions with standardized names */
out.grab = sg_grab;
out.release = sg_release;
out.drive_is_open= sg_drive_is_open;
out.issue_command = sg_issue_command;
/* Finally register drive and inquire drive information */
burn_drive_finish_enum(&out);
}
/* ts A61115 */
/* ------------------------------------------------------------------------ */
/* PORTING: Public functions. These MUST be ported. */
/* ------------------------------------------------------------------------ */
/** PORTING:
In this Linux implementation, this function mirrors the enumeration
done in sg_enumerate and ata_enumerate(). It would be better to base those
functions on this sg_give_next_adr() but the situation is not inviting.
*/
/* ts A60922 ticket 33 : called from drive.c */
/** Returns the next index number and the next enumerated drive address.
The enumeration has to cover all available and accessible drives. It is
allowed to return addresses of drives which are not available but under
some (even exotic) circumstances could be available. It is on the other
hand allowed, only to hand out addresses which can really be used right
in the moment of this call. (This implementation chooses the former.)
@param idx An opaque handle. Make no own theories about it.
@param adr Takes the reply
@param adr_size Gives maximum size of reply including final 0
@param initialize 1 = start new,
0 = continue, use no other values for now
-1 = finish
@return 1 = reply is a valid address , 0 = no further address available
-1 = severe error (e.g. adr_size too small)
*/
int sg_give_next_adr(burn_drive_enumerator_t *idx,
char adr[], int adr_size, int initialize)
{
/* os-linux.h : typedef int burn_drive_enumerator_t; */
static int sg_limit = 32, ata_limit = 26;
int baseno = 0;
if (initialize == -1)
return 0;
if (linux_sg_device_family[0] == 0)
sg_limit = 0;
if (linux_ata_device_family[0] == 0)
ata_limit = 0;
if (initialize == 1)
*idx = -1;
(*idx)++;
if (*idx >= sg_limit)
goto next_ata;
if (adr_size < 10)
return -1;
sprintf(adr, linux_sg_device_family, *idx);
return 1;
next_ata:;
baseno += sg_limit;
if (*idx - baseno >= ata_limit)
goto next_nothing;
if (adr_size < 9)
return -1;
sprintf(adr, linux_ata_device_family, 'a' + (*idx - baseno));
return 1;
next_nothing:;
baseno += ata_limit;
return 0;
}
/** Brings all available, not-whitelist-banned, and accessible drives into
libburn's list of drives.
*/
/** PORTING:
If not stricken with an incompletely unified situation like in Linux
one would rather implement this by a loop calling sg_give_next_adr().
If needed with your sg_give_next_adr() results, do a test for existence
and accessability. If burn activities are prone to external interference
on your system it is also necessary to obtain exclusive access locks on
the drives.
Hand over each accepted drive to enumerate_common() resp. its replacement
within your port.
See FreeBSD port sketch sg-freebsd-port.c for such an implementation.
*/
/* ts A61115: replacing call to sg-implementation internals from drive.c */
int scsi_enumerate_drives(void)
{
sg_enumerate();
ata_enumerate();
return 1;
}
/** Tells wether libburn has the given drive in use or exclusively reserved.
If it is "open" then libburn will eventually call sg_release() on it when
it is time to give up usage resp. reservation.
*/
/** Published as burn_drive.drive_is_open() */
int sg_drive_is_open(struct burn_drive * d)
{
/* a bit more detailed case distinction than needed */
if (d->fd == -1337)
return 0;
if (d->fd < 0)
return 0;
return 1;
}
/** Opens the drive for SCSI commands and - if burn activities are prone
to external interference on your system - obtains an exclusive access lock
on the drive. (Note: this is not physical tray locking.)
A drive that has been opened with sg_grab() will eventually be handed
over to sg_release() for closing and unreserving.
*/
int sg_grab(struct burn_drive *d)
{
int fd, os_errno= 0, ret;
/* ts A60813 */
int open_mode = O_RDWR;
/* ts A60821
<<< debug: for tracing calls which might use open drive fds */
mmc_function_spy("sg_grab");
/* ts A60813 - A60927
O_EXCL with devices is a non-POSIX feature
of Linux kernels. Possibly introduced 2002.
Mentioned in "The Linux SCSI Generic (sg) HOWTO".
*/
if(burn_sg_open_o_excl)
open_mode |= O_EXCL;
/* ts A60813
O_NONBLOCK was hardcoded here. So it should stay default mode. */
if(burn_sg_open_o_nonblock)
open_mode |= O_NONBLOCK;
/* ts A60813 - A60822
After enumeration the drive fd is probably still open.
-1337 is the initial value of burn_drive.fd and the value after
relase of drive. Unclear why not the official error return
value -1 of open(2) war used. */
if(! burn_drive_is_open(d)) {
/* ts A60821
<<< debug: for tracing calls which might use open drive fds */
mmc_function_spy("sg_grab ----------- opening");
/* ts A60926 */
if(burn_sg_open_o_excl>1) {
fd = -1;
ret = sg_open_scsi_siblings(d->devname,
d->global_index,d->sibling_fds,
&(d->sibling_count),
d->host, d->channel, d->id, d->lun);
if(ret <= 0)
goto drive_is_in_use;
}
fd = open(d->devname, open_mode);
os_errno = errno;
} else
fd= d->fd;
if (fd >= 0) {
d->fd = fd;
fcntl(fd, F_SETOWN, getpid());
d->released = 0;
return 1;
}
libdax_msgs_submit(libdax_messenger, d->global_index, 0x00020003,
LIBDAX_MSGS_SEV_SORRY, LIBDAX_MSGS_PRIO_HIGH,
"Could not grab drive", os_errno, 0);
return 0;
drive_is_in_use:;
libdax_msgs_submit(libdax_messenger, d->global_index,
0x00020003,
LIBDAX_MSGS_SEV_SORRY, LIBDAX_MSGS_PRIO_HIGH,
"Could not grab drive - already in use", 0, 0);
sg_close_drive(d);
d->fd = -1337;
return 0;
}
/** PORTING: Is mainly about the call to sg_close_drive() and wether it
implements the demanded functionality.
*/
/** Gives up the drive for SCSI commands and releases eventual access locks.
(Note: this is not physical tray locking.)
*/
int sg_release(struct burn_drive *d)
{
/* ts A60821
<<< debug: for tracing calls which might use open drive fds */
mmc_function_spy("sg_release");
if (d->fd < 1) {
burn_print(1, "release an ungrabbed drive. die\n");
return 0;
}
/* ts A60821
<<< debug: for tracing calls which might use open drive fds */
mmc_function_spy("sg_release ----------- closing");
sg_close_drive(d);
return 0;
}
/** Sends a SCSI command to the drive, receives reply and evaluates wether
the command succeeded or shall be retried or finally failed.
Returned SCSI errors shall not lead to a return value indicating failure.
The callers get notified by c->error. An SCSI failure which leads not to
a retry shall be notified via scsi_notify_error().
The Libburn_log_sg_commandS facility might be of help when problems with
a drive have to be examined. It shall stay disabled for normal use.
@return: 1 success , <=0 failure
*/
int sg_issue_command(struct burn_drive *d, struct command *c)
{
int done = 0, no_c_page = 0;
int err;
sg_io_hdr_t s;
/*
#define Libburn_log_sg_commandS 1
*/
#ifdef Libburn_log_sg_commandS
/* ts A61030 */
static FILE *fp= NULL;
static int fpcount= 0;
int i;
#endif /* Libburn_log_sg_commandS */
/* <<< ts A60821
debug: for tracing calls which might use open drive fds */
char buf[161];
sprintf(buf,"sg_issue_command d->fd= %d d->released= %d\n",
d->fd,d->released);
mmc_function_spy(buf);
#ifdef Libburn_log_sg_commandS
/* ts A61030 */
if(fp==NULL) {
fp= fopen("/tmp/libburn_sg_command_log","a");
fprintf(fp,"\n-----------------------------------------\n");
}
if(fp!=NULL) {
for(i=0;i<10;i++)
fprintf(fp,"%2.2x ", c->opcode[i]);
fprintf(fp,"\n");
fpcount++;
}
#endif /* Libburn_log_sg_commandS */
/* ts A61010 : with no fd there is no chance to send an ioctl */
if (d->fd < 0) {
c->error = 1;
return 0;
}
c->error = 0;
memset(&s, 0, sizeof(sg_io_hdr_t));
s.interface_id = 'S';
if (c->dir == TO_DRIVE)
s.dxfer_direction = SG_DXFER_TO_DEV;
else if (c->dir == FROM_DRIVE)
s.dxfer_direction = SG_DXFER_FROM_DEV;
else if (c->dir == NO_TRANSFER) {
s.dxfer_direction = SG_DXFER_NONE;
/* ts A61007 */
/* a ssert(!c->page); */
no_c_page = 1;
}
s.cmd_len = c->oplen;
s.cmdp = c->opcode;
s.mx_sb_len = 32;
s.sbp = c->sense;
memset(c->sense, 0, sizeof(c->sense));
s.timeout = 200000;
if (c->page && !no_c_page) {
s.dxferp = c->page->data;
if (c->dir == FROM_DRIVE) {
s.dxfer_len = BUFFER_SIZE;
/* touch page so we can use valgrind */
memset(c->page->data, 0, BUFFER_SIZE);
} else {
/* ts A61010 */
/* a ssert(c->page->bytes > 0); */
if (c->page->bytes <= 0) {
c->error = 1;
return 0;
}
s.dxfer_len = c->page->bytes;
}
} else {
s.dxferp = NULL;
s.dxfer_len = 0;
}
s.usr_ptr = c;
do {
err = ioctl(d->fd, SG_IO, &s);
/* ts A61010 */
/* a ssert(err != -1); */
if (err == -1) {
libdax_msgs_submit(libdax_messenger,
d->global_index, 0x0002010c,
LIBDAX_MSGS_SEV_FATAL, LIBDAX_MSGS_PRIO_HIGH,
"Failed to transfer command to drive",
errno, 0);
sg_close_drive(d);
d->released = 1;
d->busy = BURN_DRIVE_IDLE;
c->error = 1;
return -1;
}
if (s.sb_len_wr) {
if (!c->retry) {
c->error = 1;
/* A61106: rather than : return 1 */
goto ex;
}
switch (scsi_error(d, s.sbp, s.sb_len_wr)) {
case RETRY:
done = 0;
break;
case FAIL:
done = 1;
c->error = 1;
break;
}
} else {
done = 1;
}
} while (!done);
/* ts A61106 */
ex:;
if (c->error) {
scsi_notify_error(d, c, s.sbp, s.sb_len_wr, 0);
#ifdef Libburn_log_sg_commandS
if(fp!=NULL) {
fprintf(fp,"+++ key=%X asc=%2.2Xh ascq=%2.2Xh\n",
s.sbp[2], s.sbp[12], s.sbp[13]);
fpcount++;
}
#endif /* Libburn_log_sg_commandS */
}
return 1;
}
/* ts A60922 */
/** Tries to obtain SCSI address parameters.
@return 1 is success , 0 is failure
*/
int sg_obtain_scsi_adr(char *path, int *bus_no, int *host_no, int *channel_no,
int *target_no, int *lun_no)
{
int fd, ret, l;
struct my_scsi_idlun {
int x;
int host_unique_id;
};
struct my_scsi_idlun idlun;
l = strlen(linux_ata_device_family) - 2;
if (l > 0 && strncmp(path, linux_ata_device_family, l) == 0
&& path[7] >= 'a' && path[7] <= 'z' && path[8] == 0)
return 0; /* on RIP 14 all hdx return SCSI adr 0,0,0,0 */
fd = open(path, O_RDONLY | O_NONBLOCK);
if(fd < 0)
return 0;
#ifdef SCSI_IOCTL_GET_BUS_NUMBER
/* Hearsay A61005 */
if (ioctl(fd, SCSI_IOCTL_GET_BUS_NUMBER, bus_no) == -1)
*bus_no = -1;
#endif
/* http://www.tldp.org/HOWTO/SCSI-Generic-HOWTO/scsi_g_idlun.html */
ret = ioctl(fd, SCSI_IOCTL_GET_IDLUN, &idlun);
sg_close_drive_fd(path, -1, &fd, 0);
if (ret == -1)
return(0);
*host_no= (idlun.x>>24)&255;
*channel_no= (idlun.x>>16)&255;
*target_no= (idlun.x)&255;
*lun_no= (idlun.x>>8)&255;
#ifdef SCSI_IOCTL_GET_BUS_NUMBER
if(*bus_no == -1)
*bus_no = 1000 * (*host_no + 1) + *channel_no;
#else
*bus_no= *host_no;
#endif
return 1;
}
/* ts A60922 ticket 33 : called from drive.c */
/** Tells wether a text is a persistent address as listed by the enumeration
functions.
*/
int sg_is_enumerable_adr(char *adr)
{
char fname[4096];
int ret = 0, first = 1;
burn_drive_enumerator_t idx;
while (1) {
ret= sg_give_next_adr(&idx, fname, sizeof(fname), first);
if(ret <= 0)
break;
first = 0;
if (strcmp(adr, fname) == 0) {
sg_give_next_adr(&idx, fname, sizeof(fname), -1);
return 1;
}
}
sg_give_next_adr(&idx, fname, sizeof(fname), -1);
return(0);
}
Reference in New Issue View Git Blame Copy Permalink