import os
import sys
-#from optparse import OptionParser
-
-drop_capabilities='cap_sys_admin,cap_net_admin,cap_sys_boot,cap_sys_module'.split(',')
-
-"""
-parser = OptionParser()
-parser.add_option("-n", "--net",
- action="store_true", dest="netns", default=False,
- help="Enter network namespace")
-parser.add_option("-m", "--mnt",
- action="store_true", dest="mntns", default=False,
- help="Enter mount namespace")
-parser.add_option("-p", "--pid",
- action="store_true", dest="pidns", default=False,
- help="Enter pid namespace")
-
-(options, args) = parser.parse_args()
-"""
-args = sys.argv[1:]
-
-try:
- slice_name = args[0]
-except IndexError:
- print "You must specify a vm name"
- exit(1)
-
-try:
- cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name
- output = os.popen(cmd).readlines()
-except:
- print "Error finding slice %s"%slice_name
- exit(1)
-
-slice_spec = None
-for e in output:
- try:
- l = e.rstrip()
- path = l.split(':')[0]
- comp = l.rsplit(':')[-1]
- slice_name_check = comp.rsplit('/')[-1]
-
- if (slice_name_check == slice_name):
- slice_path = path
- pid = slice_path.split('/')[2]
- cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00')
- if (cmdline == '/sbin/init'):
- slice_spec = slice_path
- break
- except:
- break
-
-if (not slice_spec or not pid):
- print "Not started: %s"%slice_name
- exit(1)
-
-# Enter cgroups
-try:
- for subsystem in ['cpuset','memory','blkio']:
- open('/sys/fs/cgroup/%s/libvirt/lxc/%s/tasks'%(subsystem,slice_name),'w').write(str(os.getpid()))
-
-except:
- print "Error assigning resources: %s"%slice_name
- exit(1)
-
-r1 = setns.chcontext('/proc/%s/ns/utc'%pid)
-r2 = setns.chcontext('/proc/%s/ns/ipc'%pid)
-path = '/proc/%s/ns/net'%pid
-r3 = setns.chcontext(path)
-
-open('/proc/lxcsu','w').write(pid)
-open('/proc/pidsu','w').write(pid)
-
-
-
-pid = os.fork()
-
-cap_args = map(lambda c:'--drop='+c, drop_capabilities)
-
-if (pid == 0):
- os.execv('/usr/sbin/capsh',cap_args+['--']+args[1:])
-else:
- os.waitpid(pid,0)
+from argparse import ArgumentParser
+
+drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module'
+
+debug = False
+
+def getarch(f):
+ output = os.popen('readelf -h %s 2>&1'%f).readlines()
+ if debug: print "readelf output %s lines"%len(output)
+ classlines = [x for x in output if ('Class' in x.split(':')[0])]
+ line = classlines[0]
+ c = line.split(':')[1]
+ if ('ELF64' in c):
+ return 'x86_64'
+ elif ('ELF32' in c):
+ return 'i686'
+ else:
+ raise Exception('Could not determine architecture')
+
+def umount(fs_dir):
+ output = os.popen('/bin/umount %s 2>&1'%fs_dir).read()
+ return ('device is busy' not in fs_dir)
+
+def main ():
+ parser = ArgumentParser()
+ parser.add_argument("-n", "--nonet",
+ action="store_true", dest="netns", default=False,
+ help="Don't enter network namespace")
+ parser.add_argument("-m", "--nomnt",
+ action="store_true", dest="mntns", default=False,
+ help="Don't enter mount namespace")
+ parser.add_argument("-p", "--nopid",
+ action="store_true", dest="pidns", default=False,
+ help="Don't enter pid namespace")
+ parser.add_argument("-r", "--root",
+ action="store_true", dest="root", default=False,
+ help="Enter as root: be careful")
+ parser.add_argument("-d","--debug",
+ action='store_true', dest='debug', default=False,
+ help="debug option")
+ parser.add_argument ("slice_name")
+ parser.add_argument ("command_to_run",nargs="*")
+
+ options = parser.parse_args()
+ slice_name=options.slice_name
+ global debug
+ debug=options.debug
+
+ try:
+ cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name
+ output = os.popen(cmd).readlines()
+ if debug: print "output of grep freezer has %s lines"%len(output)
+ except:
+ print "Error finding slice %s"%slice_name
+ exit(1)
+
+ slice_spec = None
+
+ # provide a default as this is not always properly computed
+ arch = None
+
+ for e in output:
+ try:
+ l = e.rstrip()
+ path = l.split(':')[0]
+ comp = l.rsplit(':')[-1]
+ slice_name_check = comp.rsplit('/')[-1]
+ if debug: print "dealing with >%s<"%slice_name_check
+
+ if (slice_name_check == slice_name):
+ if debug: print "found %s"%slice_name
+ slice_path = path
+ pid = slice_path.split('/')[2]
+ cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00')
+ if (cmdline == '/sbin/init'):
+ slice_spec = slice_path
+ arch = getarch('/proc/%s/exe'%pid)
+ if debug: print "setting arch",arch
+ break
+ except Exception,e:
+ if debug:
+ import traceback
+ print "BEG lxcsu - ignoring exception"
+ traceback.print_exc()
+ print "END lxcsu - ignoring exception"
+ pass
+
+ if (not slice_spec or not pid):
+ print "Not started: %s"%slice_name
+ exit(1)
+
+ if arch is None:
+ arch = 'x86_64'
+ if debug: print "WARNING: setting arch to default x86_64"
+
+ # Enter cgroups
+ try:
+ for subsystem in ['cpuset','memory','blkio']:
+ open('/sys/fs/cgroup/%s/libvirt/lxc/%s/tasks'%(subsystem,slice_name),'w').write(str(os.getpid()))
+
+ except:
+ print "Error assigning resources: %s"%slice_name
+ exit(1)
+
+ try:
+ open('/sys/fs/cgroup/cpuacct/system/libvirtd.service/libvirt/lxc/%s/tasks'%slice_name,'w').write(str(os.getpid()))
+ except:
+ print "Error assigning cpuacct: %s" % slice_name
+ exit(1)
+
+ # If the slice is frozen, then we'll get an EBUSY when trying to write to the task
+ # list for the freezer cgroup. Since the user couldn't do anything anyway, it's best
+ # in this case to error out the shell. (an alternative would be to un-freeze it,
+ # add the task, and re-freeze it)
+ try:
+ f=open('/sys/fs/cgroup/freezer/libvirt/lxc/%s/tasks'%(slice_name),'w')
+ f.write(str(os.getpid()))
+ # note: we need to call f.close() explicitly, or we'll get an exception in
+ # the object destructor, which will not be caught
+ f.close()
+ except:
+ print "Error adding task to freezer cgroup. Slice is probably frozen: %s" % slice_name
+ exit(1)
+
+ setns.chcontext('/proc/%s/ns/uts'%pid)
+ setns.chcontext('/proc/%s/ns/ipc'%pid)
+
+ if (not options.netns):
+ setns.chcontext('/proc/%s/ns/net'%pid)
+
+ if (not options.mntns):
+ setns.chcontext('/proc/%s/ns/mnt'%pid)
+
+ if (not options.pidns):
+ setns.chcontext('/proc/%s/ns/pid'%pid)
+
+ if (not os.access('/proc/self',0)):
+ setns.proc_mount()
+
+ # cgroups is not yet LXC-safe, so we need to use the course grained access control
+ # strategy of unmounting the filesystem
+
+ umount_result = True
+ for subsystem in ['cpuset','cpu,cpuacct','memory','devices','freezer','net_cls','blkio','perf_event']:
+ fs_path = '/sys/fs/cgroup/%s'%subsystem
+ if (not umount(fs_path)):
+ print "Error disabling cgroup access"
+ exit(1)
+
+ if (not umount('/sys/fs/cgroup')):
+ print "Error disabling cgroup access"
+ exit(1)
+
+ pid = os.fork()
+
+ if (pid == 0):
+ cap_arg = '--drop='+drop_capabilities
+
+ if (not options.root):
+ exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--','--login']+options.command_to_run
+ else:
+ exec_args = [arch,'/usr/sbin/capsh','--','--login']+options.command_to_run
+
+ if debug:
+ print "exec'ing"
+ for arg in exec_args: print ">%s<"%arg
+ os.environ['SHELL'] = '/bin/sh'
+ os.execv('/usr/bin/setarch',exec_args)
+ else:
+ _,status = os.waitpid(pid,0)
+ exit(os.WEXITSTATUS(status))
+
+if __name__ == '__main__':
+ main()