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/*
* Handling of scsi devices - this is needed to find the
* scsi generic device corresponding to e.g. a CD writer
* on Linux.
*
* Copyright (C) 2002, Olaf Kirch <okir@lst.de>
*/
#include <sys/ioctl.h>
#include <scsi/scsi.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <ctype.h>
#include "resmgrd.h"
typedef struct scsi_id {
u_int32_t id;
u_int32_t mask;
} scsi_id_t;
typedef struct res_scsi_name res_scsi_name_t;
struct res_scsi_name {
res_name_t base;
scsi_id_t scsi_id;
};
static res_name_t * res_scsi_parse_name(const char *);
static const char * res_scsi_print_name(res_name_t *);
static void res_scsi_free_name(res_name_t *);
static int res_scsi_match(res_name_t *, res_device_t *);
static int res_scsi_open(res_name_t *, int);
static int get_scsi_id(const char *, scsi_id_t *);
#define scsi_id_match(namep, idp) \
((namep)->scsi_id.id == ((idp)->id & ((namep)->scsi_id.mask)))
res_family_t res_family_scsi = {
"scsi",
DEV_FLAGS_SCSI, /* devices must have this flag set
* otherwise we will not allow access
* to the raw SCSI device */
res_scsi_parse_name,
res_scsi_print_name,
res_scsi_free_name,
res_scsi_match,
res_scsi_open
};
/*
* SCSI devices can be named
* scsi:/dev/foobar
* scsi:bus.target.lun
* scsi:target.lun
* scsi:bus.target.lun:/dev/foobar
* scsi:target.lun:/dev/foobar
*/
res_name_t *
res_scsi_parse_name(const char *name)
{
res_scsi_name_t *sp;
scsi_id_t scsi_id;
if (name[0] == '/') {
if (get_scsi_id(name, &scsi_id) < 0)
return 0;
} else {
unsigned int n = 0, val;
scsi_id.mask = scsi_id.id = 0;
while (n < 3 && isdigit(name[0])) {
val = strtoul(name, (char **) &name, 0);
if (*name == '.' || *name == ',')
name++;
scsi_id.mask = (scsi_id.mask << 8) | 0xFF;
scsi_id.id = (scsi_id.id << 8) | (val & 0xFF);
}
if (*name != '\0' && *name != ':')
return NULL;
}
sp = (res_scsi_name_t *) calloc(1, sizeof(*sp));
sp->base.ops = &res_family_scsi;
sp->scsi_id = scsi_id;
return (res_name_t *) sp;
}
void
res_scsi_free_name(res_name_t *np)
{
free(np);
}
const char *
res_scsi_print_name(res_name_t *np)
{
static char namebuf[64];
u_int32_t id;
id = ((res_scsi_name_t *) np)->scsi_id.id;
snprintf(namebuf, sizeof(namebuf), "scsi:%u,%u,%u",
id >> 16, (id >> 8) & 0xFF, id & 0xFF);
return namebuf;
}
int
res_scsi_match(res_name_t *np, res_device_t *dev)
{
res_scsi_name_t *sp = (res_scsi_name_t *) np;
scsi_id_t dev_id;
if (get_scsi_id(dev->name, &dev_id) < 0)
return 0;
return scsi_id_match(sp, &dev_id);
}
int
res_scsi_open(res_name_t *np, int flags)
{
res_scsi_name_t *sp = (res_scsi_name_t *) np;
scsi_id_t sg_id;
static char sg_name[64];
unsigned int num;
int fd = -1;
for (num = 0; num < 64; num++) {
snprintf(sg_name, sizeof(sg_name), "/dev/sg%u", num);
if (get_scsi_id(sg_name, &sg_id) >= 0
&& scsi_id_match(sp, &sg_id)) {
/* Open the sg device */
if ((np = res_name_parse(sg_name)) != NULL)
fd = res_name_open(np, flags);
res_name_free(np);
if (fd >= 0)
return fd;
}
}
errno = EACCES;
return -1;
}
int
get_scsi_id(const char *name, struct scsi_id *idp)
{
u_int32_t ident[2];
int fd, res, bus;
if ((fd = open(name, O_RDONLY|O_NONBLOCK)) < 0)
return -1;
res = ioctl(fd, SCSI_IOCTL_GET_IDLUN, ident);
if (res >= 0)
res = ioctl(fd, SCSI_IOCTL_GET_BUS_NUMBER, &bus);
close(fd);
/* build the bus,target,lun triple.
* This is the format cdrecord uses */
if (res >= 0) {
idp->id = ident[0] & 0xFFFF; /* target,lun */
idp->id |= (bus & 0xFF) << 16;
idp->mask = 0xFFFFFF;
}
return res;
}
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