[PATCH] nfs-utils: add new tool nfsd4-show to parse output from proc files

[Achilles Gaikwad <agaikwad@redhat.com>]

This tool parses the output from the following files

 /proc/fs/nfsd/clients/*/{states,info}

- Tool has the following parameters so far:

~~~
$ /usr/sbin/nfsd4-show -h
usage: nfsd4-show [-h] [-t type] [--clientinfo] [--hostname] [-q]

Parse the nfsd states and clientinfo files.

optional arguments:
  -h, --help            show this help message and exit
  -t type, --type type  Input the type that you want to be printed: open,
                        lock, deleg, layout, all
  --clientinfo          output clients information, --hostname is implied.
  --hostname            print hostname of client instead of its ip address.
                        Longer hostnames are truncated.
  -q, --quiet           don't print the header information
~~~

- This tool enables the output to have both ip address and filaname[1]

~~~
Inode number | Type   | ip address            | Filename
33811576     | lock   | [::1]:682             | foobar
~~~

- You can also display just the open files

~~~
Inode number | Type   | Access | Deny | ip address            | Filename
:::
226493407    | open   | r-     | --   | 10.65.211.137:708     | 999
226493409    | open   | r-     | --   | 10.65.211.137:708     | ff
226493410    | open   | r-     | --   | 10.65.211.137:708     | foo
226493413    | open   | r-     | --   | 10.65.211.137:708     | open_lock.py
33811575     | open   | r-     | --   | [::1]:682             | file
33811576     | open   | rw     | --   | [::1]:682             | foobar
:::
~~~

- Handles disconnected dentries from userspace by showing filename as :

~~~
Inode number | Type   | Access | Deny | ip address            | Filename
:::
226493409    | open   | r-     | --   | 10.65.211.66:867      | disconnected dentry
226493409    | deleg  | r      |      | 10.65.211.66:867      | disconnected dentry
226493410    | open   | r-     | --   | 10.65.211.66:867      | disconnected dentry
226493410    | deleg  | r      |      | 10.65.211.66:867      | disconnected dentry
~~~

- Automatically drop the deny column for delegation

~~~
Inode number | Type   | Access | ip address            | Filename
226726004    | deleg  | r      | 10.65.211.137:708     | foo
226726013    | deleg  | r      | 10.65.211.137:708     | bar
~~~

- clientinfo would show the version of nfs that the client has mounted the share with

  the client id.

~~~
Inode number | Type   | Access | Deny | ip address            | Client ID           | vers | Filename
226726004    | open   | r-     | --   | 10.65.211.137:708     | 0xf2924e155ea84ae8  | 4.2  | foo
226726004    | deleg  | r      |      | 10.65.211.137:708     | 0xf2924e155ea84ae8  | 4.2  | foo
~~~

- hostname option would show the hostname instead of ip addresses

~~~
Inode number | Type   | Access | Deny | Hostname              | Filename
227054876    | open   | r-     | --   | vm137                 | fubar
~~~

If you do not like the header, please use the -q option.

Your feedback and review is highly apprecaited!

You will need the following patch for filename to be displayed:
[1] https://www.spinics.net/lists/linux-nfs/msg77332.html

Signed-off-by: Achilles Gaikwad <agaikwad@redhat.com>
Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
---
 configure.ac                   |   1 +
 tools/Makefile.am              |   2 +-
 tools/nfsd4-show/Makefile.am   |   9 ++
 tools/nfsd4-show/nfsd4-show.py | 219 +++++++++++++++++++++++++++++++++
 4 files changed, 230 insertions(+), 1 deletion(-)
 create mode 100644 tools/nfsd4-show/Makefile.am
 create mode 100755 tools/nfsd4-show/nfsd4-show.py

diff --git a/configure.ac b/configure.ac
index 00b32800..366f9b7c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -689,6 +689,7 @@ AC_CONFIG_FILES([
 	tools/rpcgen/Makefile
 	tools/mountstats/Makefile
 	tools/nfs-iostat/Makefile
+	tools/nfsd4-show/Makefile
 	tools/nfsconf/Makefile
 	tools/clddb-tool/Makefile
 	utils/Makefile
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 53e61170..3cebbe95 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -12,6 +12,6 @@ if CONFIG_NFSDCLD
 OPTDIRS += clddb-tool
 endif
 
-SUBDIRS = locktest rpcdebug nlmtest mountstats nfs-iostat $(OPTDIRS)
+SUBDIRS = nfsd4-show locktest rpcdebug nlmtest mountstats nfs-iostat $(OPTDIRS)
 
 MAINTAINERCLEANFILES = Makefile.in
diff --git a/tools/nfsd4-show/Makefile.am b/tools/nfsd4-show/Makefile.am
new file mode 100644
index 00000000..1b57cfb2
--- /dev/null
+++ b/tools/nfsd4-show/Makefile.am
@@ -0,0 +1,9 @@
+## Process this file with automake to produce Makefile.in
+PYTHON_FILES =  nfsd4-show.py
+
+all-local: $(PYTHON_FILES)
+
+install-data-hook:
+	$(INSTALL) -m 755 nfsd4-show.py $(DESTDIR)$(sbindir)/nfsd4-show
+
+MAINTAINERCLEANFILES=Makefile.in
\ No newline at end of file
diff --git a/tools/nfsd4-show/nfsd4-show.py b/tools/nfsd4-show/nfsd4-show.py
new file mode 100755
index 00000000..52775e66
--- /dev/null
+++ b/tools/nfsd4-show/nfsd4-show.py
@@ -0,0 +1,219 @@
+#!/bin/python3
+# -*- python-mode -*-
+'''
+    Copyright (C) 2020
+    Authors:    Achilles Gaikwad <agaikwad@redhat.com>
+                Kenneth  D'souza <kdsouza@redhat.com>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+'''
+
+import multiprocessing as mp
+import os
+import signal
+import sys
+
+try:
+    import argparse
+except ImportError:
+    print('%s:  Failed to import argparse - make sure argparse is installed!'
+        % sys.argv[0])
+    sys.exit(1)
+try:
+    import yaml
+except ImportError:
+    print('%s:  Failed to import yaml - make sure python3-pyyaml is installed!'
+        % sys.argv[0])
+    sys.exit(1)
+
+BBOLD = '\033[1;30;47m' #Bold black text with white background.
+ENDC = '\033[m' #Rest to defaults
+
+def init_worker():
+    signal.signal(signal.SIGINT, signal.SIG_IGN)
+
+# this function converts the info file to a dictionary format, sorta. :)
+def file_to_dict(path):
+    client_info = {}
+    with open(path) as f:
+        for line in f:
+            try:
+                (key, val) = line.split(':')
+                client_info[key] = val
+    # FIXME: There has to be a better way of converting tscrews he info file to a dictionary.
+            except ValueError:
+                try:
+                    (key, val) = line.split()
+                    client_info[key] = val
+                except:
+                    pass
+    return client_info
+
+# this functino gets the paths from /proc/fs/nfsd/clients/
+# returns a list of paths for each client which has nfs-share mounted.
+def getpaths():
+    path = []
+    try:
+        dirs = os.listdir('/proc/fs/nfsd/clients/')
+    except OSError as reason:
+        exit('%s' % reason)
+    if len(dirs) !=0:
+	    for i in dirs:
+		    path.append('/proc/fs/nfsd/clients/' + i + '/states')
+	    return (path)
+    else:
+	    exit('Nothing to process')
+
+# A single function to rule them all, in this function we gather all the data
+# from already populated data_list and client_info.
+def printer(data_list, argument):
+    client_info_path = data_list.pop()
+    client_info = file_to_dict(client_info_path)
+    for i in data_list:
+        for key in i:
+            inode = i[key]['superblock'].split(':')[-1]
+            # get the ip address from client_info as 'address:' note the extra
+            # ':' as a suffix to address. If there is a better way to convert
+            # the file to dictionary, please change the following value too.
+            client_ip = client_info['address:']
+            # The ip address is quoted, so we dequote it.
+            client_ip = client_ip[1:-1]
+            try:
+                # if the nfs-server reboots while the nfs-client holds the files open,
+                # the nfs-server would print the filename as '/'. For such instaces we
+                # print the output as disconnected dentry instead of '/'.
+                if(i[key]['filename']=='/'):
+                    fname = 'disconnected dentry'
+                else:
+                    fname = i[key]['filename'].split('/')[-1]
+            except KeyError:
+                # for older kernels which do not have the fname patch in kernel, they
+                # won't be able to see the fname field. Therefore post it as N/A.
+                fname = "N/A"
+            otype = i[key]['type']
+            try:
+                access = i[key]['access']
+            except:
+                access = ''
+            try:
+                deny = i[key]['deny']
+            except:
+                deny = ''
+            hostname = client_info['name'].split()[-1].split('"')[0]
+            hostname =  hostname.split('.')[0]
+            otype = i[key]['type']
+            # if the hostname is too long, it messes up with the output being in columns,
+            # therefore we truncate the hostname followed by two '..' as suffix.
+            if len(hostname) > 20:
+                hostname = hostname[0:20] + '..'
+            clientid = client_info['clientid'].strip()
+            minorversion = client_info['minor version'].rstrip().rsplit()[0]
+            # since some fields do not have deny column, we drop those if -t is either
+            # layout or lock.
+            drop = ['layout', 'lock']
+
+            # Printing the output this way instead of a single string which is concatenated
+            # this makes it better to quickly add more columns in future.
+            if(otype == argument.type or  argument.type == 'all'):
+                print('%-13s' %inode, end='| ')
+                print('%-7s' %otype, end='| ')
+                if (argument.type not in drop):
+                    print('%-7s' %access, end='| ')
+                if (argument.type not in drop and argument.type !='deleg'):
+                    print('%-5s' %deny, end='| ')
+                if (argument.hostname == True):
+                    print('%-22s' %hostname, end='| ')
+                else:
+                   print('%-22s' %client_ip, end='| ')
+                if (argument.clientinfo == True) :
+                    print('%-20s' %clientid, end='| ')
+                    print('4.%-3s' %minorversion, end='| ')
+                print(fname)
+
+def opener(path):
+    try:
+        with open(path, 'r') as nfsdata:
+            data = yaml.load(nfsdata, Loader = yaml.BaseLoader)
+            if data is not None:
+                clientinfo = path.rsplit('/', 1)[0] + '/info'
+                data.append(clientinfo)
+                return data
+
+    except OSError as reason:
+        print('%s' % reason)
+
+def print_cols(argument):
+    title_inode = 'Inode number'
+    title_otype = 'Type'
+    title_access = 'Access'
+    title_deny = 'Deny'
+    title_fname = 'Filename'
+    title_clientID = 'Client ID'
+    title_hostname = 'Hostname'
+    title_ip = 'ip address'
+    title_nfsvers = 'vers'
+
+    drop = ['lock', 'layout']
+    print(BBOLD, end='')
+    print('%-13s' %title_inode, end='| ')
+    print('%-7s' %title_otype, end='| ')
+    if (argument.type not in drop):
+        print('%-7s' %title_access, end='| ')
+    if (argument.type not in drop and argument.type !='deleg'):
+        print('%-5s' %title_deny, end='| ')
+    if (argument.hostname == True):
+        print('%-22s' %title_hostname, end='| ')
+    else:
+        print('%-22s' %title_ip, end='| ')
+    if (argument.clientinfo == True):
+        print('%-20s' %title_clientID, end='| ')
+        print('%-5s' %title_nfsvers, end='| ')
+    print(title_fname, end='')
+    print(ENDC)
+
+def nfsd4_show():
+
+    parser = argparse.ArgumentParser(description = 'Parse the nfsd states and clientinfo files.')
+    parser.add_argument('-t', '--type', metavar = 'type', type = str, choices = ['open',
+        'deleg', 'lock', 'layout', 'all'],
+        default = 'all',
+        help = 'Input the type that you want to be printed: open, lock, deleg, layout, all')
+    parser.add_argument('--clientinfo', action = 'store_true',
+        help = 'output clients information, --hostname is implied.')
+    parser.add_argument('--hostname', action = 'store_true',
+        help = 'print hostname of client instead of its ip address. Longer hostnames are truncated.')
+    parser.add_argument('-q', '--quiet', action = 'store_true',
+        help = 'don\'t print the header information')
+
+    args = parser.parse_args()
+    paths = getpaths()
+    p = mp.Pool(mp.cpu_count(), init_worker)
+    try:
+        result = p.map(opener, paths)
+        p.close()
+        p.join()
+        if len(result) !=0 and not args.quiet and result[0] is not None:
+            print_cols(args)
+
+        for i in result:
+            if i is not None:
+                printer(i, args)
+
+    except KeyboardInterrupt:
+        print('Caught KeyboardInterrupt, terminating workers')
+        p.terminate()
+        p.join()
+
+if __name__ == "__main__":
+    nfsd4_show()
-- 
2.25.4