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staging: usbip: userspace: usbip_bind.c: major rewrite of the impleme…
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…ntation

Rewrite functions in terms of libsysfs, which eliminates a lot of
helper functions simplifying the file layout. Now, the two processes
taking place here, an unbind of the old driver and a bind of
usbip-host, are single functions and have been renamed along with the
controlling function. A check to see if the device is already bound to
usbip-host is now included.

Signed-off-by: matt mooney <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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@mfmooney @gregkh
mfmooney authored and gregkh committed Jul 6, 2011
1 parent 30f0554 commit 06c465f
Showing 1 changed file with 158 additions and 145 deletions.
303 changes: 158 additions & 145 deletions drivers/staging/usbip/userspace/src/usbip_bind.c
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Original file line number Diff line number Diff line change
Expand Up @@ -18,18 +18,23 @@

#include <sysfs/libsysfs.h>

#include <limits.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <fcntl.h>
#include <getopt.h>
#include <unistd.h>

#include "usbip_common.h"
#include "utils.h"
#include "usbip.h"

enum unbind_status {
UNBIND_ST_OK,
UNBIND_ST_USBIP_HOST,
UNBIND_ST_FAILED
};

static const char usbip_bind_usage_string[] =
"usbip bind <args>\n"
" -b, --busid=<busid> Bind " USBIP_HOST_DRV_NAME ".ko to device "
Expand All @@ -40,195 +45,202 @@ void usbip_bind_usage(void)
printf("usage: %s", usbip_bind_usage_string);
}

static const char unbind_path_format[] = "/sys/bus/usb/devices/%s/driver/unbind";

/* buggy driver may cause dead lock */
static int unbind_interface_busid(char *busid)
/* call at unbound state */
static int bind_usbip(char *busid)
{
char unbind_path[SYSFS_PATH_MAX];
int fd;
int ret;

snprintf(unbind_path, sizeof(unbind_path), unbind_path_format, busid);

fd = open(unbind_path, O_WRONLY);
if (fd < 0) {
dbg("opening unbind_path failed: %d", fd);
char bus_type[] = "usb";
char attr_name[] = "bind";
char sysfs_mntpath[SYSFS_PATH_MAX];
char bind_attr_path[SYSFS_PATH_MAX];
char intf_busid[SYSFS_BUS_ID_SIZE];
struct sysfs_device *busid_dev;
struct sysfs_attribute *bind_attr;
struct sysfs_attribute *bConfValue;
struct sysfs_attribute *bNumIntfs;
int i, failed = 0;
int rc, ret = -1;

rc = sysfs_get_mnt_path(sysfs_mntpath, SYSFS_PATH_MAX);
if (rc < 0) {
err("sysfs must be mounted: %s", strerror(errno));
return -1;
}

ret = write(fd, busid, strnlen(busid, SYSFS_BUS_ID_SIZE));
if (ret < 0) {
dbg("write to unbind_path failed: %d", ret);
close(fd);
return -1;
}

close(fd);

return 0;
}

static int unbind_interface(char *busid, int configvalue, int interface)
{
char inf_busid[SYSFS_BUS_ID_SIZE];
dbg("unbinding interface");

snprintf(inf_busid, SYSFS_BUS_ID_SIZE, "%s:%d.%d", busid, configvalue,
interface);
snprintf(bind_attr_path, sizeof(bind_attr_path), "%s/%s/%s/%s/%s/%s",
sysfs_mntpath, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
USBIP_HOST_DRV_NAME, attr_name);

return unbind_interface_busid(inf_busid);
}

static int unbind(char *busid)
{
int configvalue = 0;
int ninterface = 0;
int devclass = 0;
int i;
int failed = 0;

configvalue = read_bConfigurationValue(busid);
ninterface = read_bNumInterfaces(busid);
devclass = read_bDeviceClass(busid);

if (configvalue < 0 || ninterface < 0 || devclass < 0) {
dbg("read config and ninf value, removed?");
bind_attr = sysfs_open_attribute(bind_attr_path);
if (!bind_attr) {
dbg("problem getting bind attribute: %s", strerror(errno));
return -1;
}

if (devclass == 0x09) {
dbg("skip unbinding of hub");
return -1;
busid_dev = sysfs_open_device(bus_type, busid);
if (!busid_dev) {
dbg("sysfs_open_device %s failed: %s", busid, strerror(errno));
goto err_close_bind_attr;
}

for (i = 0; i < ninterface; i++) {
char driver[PATH_MAX];
int ret;

memset(&driver, 0, sizeof(driver));

getdriver(busid, configvalue, i, driver, PATH_MAX-1);
bConfValue = sysfs_get_device_attr(busid_dev, "bConfigurationValue");
bNumIntfs = sysfs_get_device_attr(busid_dev, "bNumInterfaces");

dbg(" %s:%d.%d -> %s ", busid, configvalue, i, driver);

if (!strncmp("none", driver, PATH_MAX))
continue; /* unbound interface */
if (!bConfValue || !bNumIntfs) {
dbg("problem getting device attributes: %s",
strerror(errno));
goto err_close_busid_dev;
}

#if 0
if (!strncmp("usbip", driver, PATH_MAX))
continue; /* already bound to usbip */
#endif
for (i = 0; i < atoi(bNumIntfs->value); i++) {
snprintf(intf_busid, SYSFS_BUS_ID_SIZE, "%s:%.1s.%d", busid,
bConfValue->value, i);

/* unbinding */
ret = unbind_interface(busid, configvalue, i);
if (ret < 0) {
dbg("unbind driver at %s:%d.%d failed",
busid, configvalue, i);
rc = sysfs_write_attribute(bind_attr, intf_busid,
SYSFS_BUS_ID_SIZE);
if (rc < 0) {
dbg("bind driver at %s failed", intf_busid);
failed = 1;
}
}

if (failed)
return -1;
else
return 0;
}

static const char bind_path_format[] = "/sys/bus/usb/drivers/%s/bind";
if (!failed)
ret = 0;

static int bind_interface_busid(char *busid, char *driver)
{
char bind_path[PATH_MAX];
int fd;
int ret;
err_close_busid_dev:
sysfs_close_device(busid_dev);
err_close_bind_attr:
sysfs_close_attribute(bind_attr);

snprintf(bind_path, sizeof(bind_path), bind_path_format, driver);
return ret;
}

fd = open(bind_path, O_WRONLY);
if (fd < 0)
/* buggy driver may cause dead lock */
static int unbind_other(char *busid)
{
char bus_type[] = "usb";
char intf_busid[SYSFS_BUS_ID_SIZE];
struct sysfs_device *busid_dev;
struct sysfs_device *intf_dev;
struct sysfs_driver *intf_drv;
struct sysfs_attribute *unbind_attr;
struct sysfs_attribute *bConfValue;
struct sysfs_attribute *bDevClass;
struct sysfs_attribute *bNumIntfs;
int i, rc;
enum unbind_status status = UNBIND_ST_OK;

busid_dev = sysfs_open_device(bus_type, busid);
if (!busid_dev) {
dbg("sysfs_open_device %s failed: %s", busid, strerror(errno));
return -1;
}

ret = write(fd, busid, strnlen(busid, SYSFS_BUS_ID_SIZE));
if (ret < 0) {
close(fd);
return -1;
bConfValue = sysfs_get_device_attr(busid_dev, "bConfigurationValue");
bDevClass = sysfs_get_device_attr(busid_dev, "bDeviceClass");
bNumIntfs = sysfs_get_device_attr(busid_dev, "bNumInterfaces");
if (!bConfValue || !bDevClass || !bNumIntfs) {
dbg("problem getting device attributes: %s",
strerror(errno));
goto err_close_busid_dev;
}

close(fd);
if (!strncmp(bDevClass->value, "09", bDevClass->len)) {
dbg("skip unbinding of hub");
goto err_close_busid_dev;
}

return 0;
}
for (i = 0; i < atoi(bNumIntfs->value); i++) {
snprintf(intf_busid, SYSFS_BUS_ID_SIZE, "%s:%.1s.%d", busid,
bConfValue->value, i);
intf_dev = sysfs_open_device(bus_type, intf_busid);
if (!intf_dev) {
dbg("could not open interface device: %s",
strerror(errno));
goto err_close_busid_dev;
}

static int bind_interface(char *busid, int configvalue, int interface, char *driver)
{
char inf_busid[SYSFS_BUS_ID_SIZE];
dbg("%s -> %s", intf_dev->name, intf_dev->driver_name);

snprintf(inf_busid, SYSFS_BUS_ID_SIZE, "%s:%d.%d", busid, configvalue,
interface);
if (!strncmp("unknown", intf_dev->driver_name, SYSFS_NAME_LEN))
/* unbound interface */
continue;

return bind_interface_busid(inf_busid, driver);
}
if (!strncmp(USBIP_HOST_DRV_NAME, intf_dev->driver_name,
SYSFS_NAME_LEN)) {
/* already bound to usbip-host */
status = UNBIND_ST_USBIP_HOST;
continue;
}

/* call at unbound state */
static int bind_to_usbip(char *busid)
{
int configvalue = 0;
int ninterface = 0;
int i;
int failed = 0;
/* unbinding */
intf_drv = sysfs_open_driver(bus_type, intf_dev->driver_name);
if (!intf_drv) {
dbg("could not open interface driver on %s: %s",
intf_dev->name, strerror(errno));
goto err_close_intf_dev;
}

configvalue = read_bConfigurationValue(busid);
ninterface = read_bNumInterfaces(busid);
unbind_attr = sysfs_get_driver_attr(intf_drv, "unbind");
if (!unbind_attr) {
dbg("problem getting interface driver attribute: %s",
strerror(errno));
goto err_close_intf_drv;
}

if (configvalue < 0 || ninterface < 0) {
dbg("read config and ninf value, removed?");
return -1;
rc = sysfs_write_attribute(unbind_attr, intf_dev->bus_id,
SYSFS_BUS_ID_SIZE);
if (rc < 0) {
/* NOTE: why keep unbinding other interfaces? */
dbg("unbind driver at %s failed", intf_dev->bus_id);
status = UNBIND_ST_FAILED;
}

sysfs_close_driver(intf_drv);
sysfs_close_device(intf_dev);
}

for (i = 0; i < ninterface; i++) {
int ret;
goto out;

ret = bind_interface(busid, configvalue, i,
USBIP_HOST_DRV_NAME);
if (ret < 0) {
dbg("bind usbip at %s:%d.%d, failed",
busid, configvalue, i);
failed = 1;
/* need to contine binding at other interfaces */
}
}
err_close_intf_drv:
sysfs_close_driver(intf_drv);
err_close_intf_dev:
sysfs_close_device(intf_dev);
err_close_busid_dev:
status = UNBIND_ST_FAILED;
out:
sysfs_close_device(busid_dev);

if (failed)
return -1;
else
return 0;
return status;
}

static int use_device_by_usbip(char *busid)
static int bind_device(char *busid)
{
int ret;
int rc;

ret = unbind(busid);
if (ret < 0) {
dbg("unbind drivers of %s, failed", busid);
rc = unbind_other(busid);
if (rc == UNBIND_ST_FAILED) {
err("could not unbind driver from device on busid %s", busid);
return -1;
} else if (rc == UNBIND_ST_USBIP_HOST) {
err("device on busid %s is already bound to %s", busid,
USBIP_HOST_DRV_NAME);
return -1;
}

ret = modify_match_busid(busid, 1);
if (ret < 0) {
dbg("add %s to match_busid, failed", busid);
rc = modify_match_busid(busid, 1);
if (rc < 0) {
err("unable to bind device on %s", busid);
return -1;
}

ret = bind_to_usbip(busid);
if (ret < 0) {
dbg("bind usbip to %s, failed", busid);
rc = bind_usbip(busid);
if (rc < 0) {
err("could not bind device to %s", USBIP_HOST_DRV_NAME);
modify_match_busid(busid, 0);
return -1;
}

dbg("bind %s complete!", busid);
printf("bind device on busid %s: complete\n", busid);

return 0;
}
Expand All @@ -237,8 +249,9 @@ int usbip_bind(int argc, char *argv[])
{
static const struct option opts[] = {
{ "busid", required_argument, NULL, 'b' },
{ NULL, 0, NULL, 0 }
{ NULL, 0, NULL, 0 }
};

int opt;
int ret = -1;

Expand All @@ -250,7 +263,7 @@ int usbip_bind(int argc, char *argv[])

switch (opt) {
case 'b':
ret = use_device_by_usbip(optarg);
ret = bind_device(optarg);
goto out;
default:
goto err_out;
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