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1#!/usr/bin/python2
2
3# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
4# Use of this source code is governed by a BSD-style license that can be
5# found in the LICENSE file.
6
7"""This is a module to scan /sys/block/ virtual FS, query udev
8
9It provides a list of all removable or USB devices connected to the machine on
10which the module is running.
11It can be used from command line or from a python script.
12
13To use it as python module it's enough to call the get_all() function.
14@see |get_all| documentation for the output format
15|get_all()| output is human readable (as oppposite to python's data structures)
16"""
17
18import logging, os, re
19
20# this script can be run at command line on DUT (ie /usr/local/autotest
21# contains only the client/ subtree), on a normal autotest
22# installation/repository or as a python module used on a client-side test.
23import common
24
25from autotest_lib.client.common_lib import error
26from autotest_lib.client.common_lib import utils
27
28INFO_PATH = "/sys/block"
29UDEV_CMD_FOR_SERIAL_NUMBER = "udevadm info -a -n %s | grep -iE 'ATTRS{" \
30                             "serial}' | head -n 1"
31LSUSB_CMD = "lsusb -v | grep -iE '^Device Desc|bcdUSB|iSerial'"
32DESC_PATTERN = r'Device Descriptor:'
33BCDUSB_PATTERN = r'bcdUSB\s+(\d+\.\d+)'
34ISERIAL_PATTERN = r'iSerial\s+\d\s(\S*)'
35UDEV_SERIAL_PATTERN = r'=="(.*)"'
36
37
38def read_file(path_to_file, host=None):
39    """Reads the file and returns the file content
40    @param path_to_file: Full path to the file
41    @param host: DUT object
42    @return: Returns the content of file
43    """
44    if host:
45        if not host.path_exists(path_to_file):
46            raise error.TestError("No such file or directory %s" % path_to_file)
47        return host.run('cat %s' % path_to_file).stdout.strip()
48
49    if not os.path.isfile(path_to_file):
50        raise error.TestError("No such file or directory %s" % path_to_file)
51    return utils.read_file(path_to_file).strip()
52
53
54def system_output(command, host=None, ignore_status=False):
55    """Executes command on client
56
57    @param host: DUT object
58    @param command: command to execute
59    @return: output of command
60    """
61    if host:
62        return host.run(command, ignore_status=ignore_status).stdout.strip()
63
64    return utils.system_output(command, ignore_status=ignore_status)
65
66
67def get_udev_info(blockdev, method='udev', host=None):
68    """Get information about |blockdev|
69
70    @param blockdev: a block device, e.g., /dev/sda1 or /dev/sda
71    @param method: either 'udev' (default) or 'blkid'
72    @param host: DUT object
73
74    @return a dictionary with two or more of the followig keys:
75        "ID_BUS", "ID_MODEL": always present
76        "ID_FS_UUID", "ID_FS_TYPE", "ID_FS_LABEL": present only if those info
77         are meaningul and present for the queried device
78    """
79    ret = {}
80    cmd = None
81    ignore_status = False
82
83    if method == "udev":
84        cmd = "udevadm info --name %s --query=property" % blockdev
85    elif method == "blkid":
86        # this script is run as root in a normal autotest run,
87        # so this works: It doesn't have access to the necessary info
88        # when run as a non-privileged user
89        cmd = "blkid -c /dev/null -o udev %s" % blockdev
90        ignore_status = True
91
92    if cmd:
93        output = system_output(cmd, host, ignore_status=ignore_status)
94
95        udev_keys = ("ID_BUS", "ID_MODEL", "ID_FS_UUID", "ID_FS_TYPE",
96                     "ID_FS_LABEL")
97        for line in output.splitlines():
98            udev_key, udev_val = line.split('=')
99
100            if udev_key in udev_keys:
101                ret[udev_key] = udev_val
102
103    return ret
104
105
106def get_lsusb_info(host=None):
107    """Get lsusb info in list format
108
109    @param host: DUT object
110    @return: Returns lsusb output in list format
111    """
112
113    usb_info_list = []
114    # Getting the USB type and Serial number info using 'lsusb -v'. Sample
115    # output is shown in below
116    # Device Descriptor:
117    #      bcdUSB               2.00
118    #      iSerial                 3 131BC7
119    #      bcdUSB               2.00
120    # Device Descriptor:
121    #      bcdUSB               2.10
122    #      iSerial                 3 001A4D5E8634B03169273995
123
124    lsusb_output = system_output(LSUSB_CMD, host)
125    # we are parsing each line and getting the usb info
126    for line in lsusb_output.splitlines():
127        desc_matched = re.search(DESC_PATTERN, line)
128        bcdusb_matched = re.search(BCDUSB_PATTERN, line)
129        iserial_matched = re.search(ISERIAL_PATTERN, line)
130        if desc_matched:
131            usb_info = {}
132        elif bcdusb_matched:
133            # bcdUSB may appear multiple time. Drop the remaining.
134            usb_info['bcdUSB'] = bcdusb_matched.group(1)
135        elif iserial_matched:
136            usb_info['iSerial'] = iserial_matched.group(1)
137            usb_info_list.append(usb_info)
138    logging.debug('lsusb output is %s', usb_info_list)
139    return usb_info_list
140
141
142def get_usbdevice_type_and_serial(device, lsusb_info, host=None):
143    """Get USB device type and Serial number
144
145    @param device: USB device mount point Example: /dev/sda or /dev/sdb
146    @param lsusb_info: lsusb info
147    @param host: DUT object
148    @return: Returns the information about USB type and the serial number
149            of the device
150    """
151
152    # Comparing the lsusb serial number with udev output serial number
153    # Both serial numbers should be same. Sample udev command output is
154    # shown in below.
155    # ATTRS{serial}=="001A4D5E8634B03169273995"
156    udev_serial_output = system_output(UDEV_CMD_FOR_SERIAL_NUMBER % device,
157                                       host)
158    udev_serial_matched = re.search(UDEV_SERIAL_PATTERN, udev_serial_output)
159    if udev_serial_matched:
160        udev_serial = udev_serial_matched.group(1)
161        logging.debug("udev serial number is %s", udev_serial)
162        for usb_details in lsusb_info:
163            if usb_details['iSerial'] == udev_serial:
164                return usb_details.get('bcdUSB'), udev_serial
165    return None, None
166
167def get_partition_info(part_path, bus, model, partid=None, fstype=None,
168                       label=None, block_size=0, is_removable=False,
169                       lsusb_info=[], host=None):
170    """Return information about a device as a list of dictionaries
171
172    Normally a single device described by the passed parameters will match a
173    single device on the system, and thus a single element list as return
174    value; although it's possible that a single block device is associated with
175    several mountpoints, this scenario will lead to a dictionary for each
176    mountpoint.
177
178    @param part_path: full partition path under |INFO_PATH|
179                      e.g., /sys/block/sda or /sys/block/sda/sda1
180    @param bus: bus, e.g., 'usb' or 'ata', according to udev
181    @param model: device moduel, e.g., according to udev
182    @param partid: partition id, if present
183    @param fstype: filesystem type, if present
184    @param label: filesystem label, if present
185    @param block_size: filesystem block size
186    @param is_removable: whether it is a removable device
187    @param host: DUT object
188    @param lsusb_info: lsusb info
189
190    @return a list of dictionaries contaning each a partition info.
191            An empty list can be returned if no matching device is found
192    """
193    ret = []
194    # take the partitioned device name from the /sys/block/ path name
195    part = part_path.split('/')[-1]
196    device = "/dev/%s" % part
197
198    if not partid:
199        info = get_udev_info(device, "blkid", host=host)
200        partid = info.get('ID_FS_UUID', None)
201        if not fstype:
202            fstype = info.get('ID_FS_TYPE', None)
203        if not label:
204            label = partid
205
206    readonly = read_file("%s/ro" % part_path, host)
207    if not int(readonly):
208        partition_blocks = read_file("%s/size" % part_path, host)
209        size = block_size * int(partition_blocks)
210
211        stub = {}
212        stub['device'] = device
213        stub['bus'] = bus
214        stub['model'] = model
215        stub['size'] = size
216
217        # look for it among the mounted devices first
218        mounts = read_file("/proc/mounts", host).splitlines()
219        seen = False
220        for line in mounts:
221            dev, mount, proc_fstype, flags = line.split(' ', 3)
222
223            if device == dev:
224                if 'rw' in flags.split(','):
225                    seen = True # at least one match occurred
226
227                    # Sorround mountpoint with quotes, to make it parsable in
228                    # case of spaces. Also information retrieved from
229                    # /proc/mount override the udev passed ones (e.g.,
230                    # proc_fstype instead of fstype)
231                    dev = stub.copy()
232                    dev['fs_uuid'] = partid
233                    dev['fstype'] = proc_fstype
234                    dev['is_mounted'] = True
235                    # When USB device is mounted automatically after login a
236                    # non-labelled drive is mounted to:
237                    # '/media/removable/USB Drive'
238                    # Here an octal unicode '\040' is added to the path
239                    # replacing ' ' (space).
240                    # Following '.decode('unicode-escape')' handles the same
241                    dev['mountpoint'] = mount.decode('unicode-escape')
242                    dev['is_removable'] = is_removable
243                    dev['usb_type'], dev['serial'] = \
244                            get_usbdevice_type_and_serial(dev['device'],
245                                                          lsusb_info=lsusb_info,
246                                                          host=host)
247                    ret.append(dev)
248
249        # If not among mounted devices, it's just attached, print about the
250        # same information but suggest a place where the user can mount the
251        # device instead
252        if not seen:
253            # we consider it if it's removable and and a partition id
254            # OR it's on the USB bus or ATA bus.
255            # Some USB HD do not get announced as removable, but they should be
256            # showed.
257            # There are good changes that if it's on a USB bus it's removable
258            # and thus interesting for us, independently whether it's declared
259            # removable
260            if (is_removable and partid) or bus in ['usb', 'ata']:
261                if not label:
262                    info = get_udev_info(device, 'blkid', host=host)
263                    label = info.get('ID_FS_LABEL', partid)
264
265                dev = stub.copy()
266                dev['fs_uuid'] = partid
267                dev['fstype'] = fstype
268                dev['is_mounted'] = False
269                dev['mountpoint'] = "/media/removable/%s" % label
270                dev['is_removable'] = is_removable
271                dev['usb_type'], dev['serial'] = \
272                        get_usbdevice_type_and_serial(dev['device'],
273                                                      lsusb_info=lsusb_info,
274                                                      host=host)
275                ret.append(dev)
276        return ret
277
278
279def get_device_info(blockdev, lsusb_info, host=None):
280    """Retrieve information about |blockdev|
281
282    @see |get_partition_info()| doc for the dictionary format
283
284    @param blockdev: a block device name, e.g., "sda".
285    @param host: DUT object
286    @param lsusb_info: lsusb info
287    @return a list of dictionary, with each item representing a found device
288    """
289    ret = []
290
291    spath = "%s/%s" % (INFO_PATH, blockdev)
292    block_size = int(read_file("%s/queue/physical_block_size" % spath,
293                                   host))
294    is_removable = bool(int(read_file("%s/removable" % spath, host)))
295
296    info = get_udev_info(blockdev, "udev", host=host)
297    dev_bus = info['ID_BUS']
298    dev_model = info['ID_MODEL']
299    dev_fs = info.get('ID_FS_TYPE', None)
300    dev_uuid = info.get('ID_FS_UUID', None)
301    dev_label = info.get('ID_FS_LABEL', dev_uuid)
302
303    has_partitions = False
304    for basename in system_output('ls %s' % spath, host).splitlines():
305        partition_path = "%s/%s" % (spath, basename)
306        # we want to check if within |spath| there are subdevices with
307        # partitions
308        # e.g., if within /sys/block/sda sda1 and other partition are present
309        if not re.match("%s[0-9]+" % blockdev, basename):
310            continue # ignore what is not a subdevice
311
312        # |blockdev| has subdevices: get info for them
313        has_partitions = True
314        devs = get_partition_info(partition_path, dev_bus, dev_model,
315                                  block_size=block_size,
316                                  is_removable=is_removable,
317                                  lsusb_info=lsusb_info, host=host)
318        ret.extend(devs)
319
320    if not has_partitions:
321        devs = get_partition_info(spath, dev_bus, dev_model, dev_uuid, dev_fs,
322                                  dev_label, block_size=block_size,
323                                  is_removable=is_removable,
324                                  lsusb_info=lsusb_info, host=host)
325        ret.extend(devs)
326
327    return ret
328
329
330def get_all(host=None):
331    """Return all removable or USB storage devices attached
332
333    @param host: DUT object
334    @return a list of dictionaries, each list element describing a device
335    """
336    ret = []
337    lsusb_info = get_lsusb_info(host)
338    for dev in system_output('ls %s' % INFO_PATH, host).splitlines():
339        # Among block devices we need to filter out what are virtual
340        if re.match("s[a-z]+", dev):
341            # for each of them try to obtain some info
342            ret.extend(get_device_info(dev, lsusb_info, host=host))
343    return ret
344
345
346def main():
347    for device in get_all():
348        print ("%(device)s %(bus)s %(model)s %(size)d %(fs_uuid)s %(fstype)s "
349               "%(is_mounted)d %(mountpoint)s %(usb_type)s %(serial)s" %
350               device)
351
352
353if __name__ == "__main__":
354    main()
355