staging: usbip: userspace: usbip_bind.c: major rewrite of the implementation

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 <mfm@muteddisk.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/usbip/userspace/src/usbip_bind.c b/drivers/staging/usbip/userspace/src/usbip_bind.c
index 978b7aa..9ecaf6e 100644 (file)
--- a/drivers/staging/usbip/userspace/src/usbip_bind.c
+++ b/drivers/staging/usbip/userspace/src/usbip_bind.c
@@ -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 "
@@ -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;
 }
@@ -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;
 
@@ -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;