-#!/usr/bin/python
+#!/usr/bin/python3
import sys
import os
import setns
+import pwd
from argparse import ArgumentParser
-drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module'
-
# can set to True here, but also use the -d option
debug = False
-def getarch(f):
- output = os.popen('readelf -h %s 2>&1'%f).readlines()
+
+def getarch(pid):
+ exe_filename = '/proc/%s/exe' % pid
+ output = os.popen('readelf -h %s 2>&1' % exe_filename).readlines()
classlines = [x for x in output if ('Class' in x.split(':')[0])]
line = classlines[0]
c = line.split(':')[1]
elif ('ELF32' in c):
return 'i686'
else:
- raise Exception('Could not determine architecture')
+ raise Exception('Could not determine architecture for pid %s' % pid)
+
+
+def get_cgroup_subdirs_for_pid(pid):
+ cgroup_info_file = '/proc/%s/cgroup' % pid
+ cgroup_lines = open(cgroup_info_file).read().splitlines()
+
+ subdirs = {}
+ for line in cgroup_lines:
+ try:
+ _, cgroup_name, subdir = line.split(':')
+ subdirs[cgroup_name] = subdir
+ except Exception as e:
+ print("Error reading cgroup info: %s" % str(e))
+ pass
-def umount(fs_dir):
- output = os.popen('/bin/umount %s 2>&1'%fs_dir).read()
+ return subdirs
+
+
+def umount(fs_dir, opts=''):
+ output = os.popen('/bin/umount %s %s 2>&1' % (opts, fs_dir)).read()
return ('device is busy' not in output)
-def main ():
+
+def main():
parser = ArgumentParser()
parser.add_argument("-n", "--nonet",
- action="store_true", dest="netns", default=False,
+ action="store_true", dest="no_netns", default=False,
help="Don't enter network namespace")
parser.add_argument("-m", "--nomnt",
- action="store_true", dest="mntns", default=False,
+ action="store_true", dest="no_mntns", default=False,
help="Don't enter mount namespace")
parser.add_argument("-p", "--nopid",
- action="store_true", dest="pidns", default=False,
+ action="store_true", dest="no_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("-i","--internal",
+ parser.add_argument("-i", "--internal",
action="store_true", dest="internal", default=False,
help="does *not* prepend '-- -c' to arguments - or invoke lxcsu-internal")
- parser.add_argument("-d","--debug",
+ parser.add_argument("-d", "--debug",
action='store_true', dest='debug', default=False,
help="debug option")
- parser.add_argument("-s","--nosliceuid", dest="nosliceuid", default=False,
+ parser.add_argument("-s", "--nosliceuid",
+ action='store_true', dest="nosliceuid", default=False,
help="do not change to slice uid inside of slice")
- parser.add_argument ("slice_name")
- parser.add_argument ("command_to_run",nargs="*")
+ parser.add_argument("-o", "--noslicehome",
+ action='store_true', dest="noslicehome", default=False,
+ help="do not change to slice home directory inside of slice")
+
+ if os.path.exists("/etc/lxcsu_default"):
+ defaults = parser.parse_args(
+ file("/etc/lxcsu_default", "r").read().split())
+ parser.set_defaults(**defaults.__dict__)
+
+ parser.add_argument("slice_name")
+ parser.add_argument("command_to_run", nargs="*")
args = parser.parse_args()
- slice_name=args.slice_name
+ slice_name = args.slice_name
+
+ # support for either setting debug at the top of this file, or on the command-line
+ if args.debug:
+ global debug
+ debug = True
+
+ # somehow some older nodes won't be able to find the login name in /etc/passwd
+ # when this is done down the road, so compute slice_uid while in a safe env
+ # even though we don't use the slice_uid any more, this is still
+ # checked later on as a means to ensure existence of the slice account
+ try:
+ slice_uid = pwd.getpwnam(slice_name).pw_uid
+ except Exception as e:
+ if debug:
+ import traceback
+ print('error while computing slice_uid', e)
+ traceback.print_exc()
+ slice_uid = None
# unless we run the symlink 'lxcsu-internal', or we specify the -i option, prepend '--' '-c'
- if sys.argv[0].find('internal')>=0: args.internal=True
+ if sys.argv[0].find('internal') >= 0:
+ args.internal = True
- if len(args.command_to_run)>0 and (args.command_to_run[0] == "/sbin/service"):
+ if len(args.command_to_run) > 0 and (args.command_to_run[0] == "/sbin/service"):
# A quick hack to support nodemanager interfaces.py when restarting
# networking in a slice.
args.nosliceuid = True
# plain lxcsu
if not args.internal:
# no command given: enter interactive shell
- if not args.command_to_run: args.command_to_run=['/bin/sh']
- args.command_to_run = [ '-c' ] + [" ".join(args.command_to_run)]
-
- # support for either setting debug at the top of this file, or on the command-line
- if args.debug:
- global debug
- debug=True
+ if not args.command_to_run:
+ args.command_to_run = ['/bin/sh']
+ args.command_to_run = ['-c'] + [" ".join(args.command_to_run)]
try:
- cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name
- output = os.popen(cmd).readlines()
+ cmd = '/usr/bin/virsh --connect lxc:/// domid %s' % slice_name
+ # convert to int as a minimal raincheck
+ driver_pid = int(os.popen(cmd).read().strip())
+ # locate the pid for the - expected - single child, that would be the init for that VM
+ #init_pid = int(open("/proc/%s/task/%s/children"%(driver_pid,driver_pid)).read().strip())
+ init_pid = int(os.popen('pgrep -P %s' %
+ driver_pid).readlines()[0].strip())
+ # Thierry: I am changing the code below to use init_pid instead of driver_pid
+ # for the namespace handling features, that I was able to check
+ # I've left the other ones as they were, i.e. using driver_pid, but I suspect
+ # some should be changed as well
+
except:
- print "Error finding slice %s"%slice_name
+ print("Domain %s not found" % 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') or (cmdline.startswith("init [")):
- slice_spec = slice_path
- arch = getarch('/proc/%s/exe'%pid)
- 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
+ if not driver_pid or not init_pid:
+ print("Domain %s not started" % slice_name)
exit(1)
- if arch is None:
- arch = 'x86_64'
+ if debug:
+ print("Found driver_pid", driver_pid, 'and init_pid=', init_pid)
+ # driver_pid is always x86_64, we need to look at the VM's init process here
+ arch = getarch(init_pid)
# Set sysctls specific to slice
sysctls = []
- sysctl_dir = '/etc/planetlab/vsys-attributes/%s'%slice_name
- if (os.access(sysctl_dir,0)):
+ sysctl_dir = '/etc/planetlab/vsys-attributes/%s' % slice_name
+ if (os.access(sysctl_dir, 0)):
entries = os.listdir(sysctl_dir)
for e in entries:
prefix = 'vsys_sysctl.'
if (e.startswith(prefix)):
- sysctl_file = '/'.join([sysctl_dir,e])
+ sysctl_file = '/'.join([sysctl_dir, e])
sysctl_name = e[len(prefix):]
sysctl_val = open(sysctl_file).read()
sysctls.append((sysctl_file, sysctl_name, sysctl_val))
- # 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)
+ # xxx probably init_pid here too
+ subdirs = get_cgroup_subdirs_for_pid(driver_pid)
+ sysfs_root = '/sys/fs/cgroup'
# 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 args.pidns):
- setns.chcontext('/proc/%s/ns/pid'%pid)
-
- if (not args.netns):
- setns.chcontext('/proc/%s/ns/net'%pid)
-
- if (not args.mntns):
- setns.chcontext('/proc/%s/ns/mnt'%pid)
+ # Enter cgroups
+ current_cgroup = ''
+ for subsystem in ['cpuset', 'memory', 'blkio', 'cpuacct', 'cpuacct,cpu', 'freezer']:
+ try:
+ current_cgroup = subsystem
+
+ # There seems to be a bug in the cgroup schema: cpuacct,cpu can become cpu,cpuacct
+ # We need to handle both
+ task_path_alt = None
+ try:
+ subsystem_comps = subsystem.split(',')
+ subsystem_comps.reverse()
+ subsystem_alt = ','.join(subsystem_comps)
+ tasks_path_alt = [sysfs_root, subsystem_alt,
+ subdirs[subsystem], 'tasks']
+ except Exception as e:
+ pass
+
+ tasks_path = [sysfs_root, subsystem, subdirs[subsystem], 'tasks']
+ tasks_path_str = '/'.join(tasks_path)
+
+ try:
+ f = open(tasks_path_str, 'w')
+ except:
+ tasks_path_alt_str = '/'.join(tasks_path_alt)
+ f = open(tasks_path_alt_str, 'w')
+
+ f.write(str(os.getpid()))
+ if (subsystem == 'freezer'):
+ f.close()
+
+ except Exception as e:
+ if (subsystem not in subdirs):
+ pass
+ else:
+ if debug:
+ print(e)
+ print("Error assigning cgroup %s (pid=%s) for slice %s" %
+ (current_cgroup, driver_pid, slice_name))
+ exit(1)
+
+ def chcontext(path):
+ retcod = setns.chcontext(path)
+ if retcod != 0:
+ print('WARNING - setns(%s)=>%s (ignored)' % (path, retcod))
+ return retcod
+
+ # Use init_pid and not driver_pid to locate reference namespaces
+ ref_ns = "/proc/%s/ns/" % init_pid
+
+ if True:
+ chcontext(ref_ns+'uts')
+ if True:
+ chcontext(ref_ns+'ipc')
+
+ if (not args.no_pidns):
+ chcontext(ref_ns+'pid')
+ if (not args.no_netns):
+ chcontext(ref_ns+'net')
+ if (not args.no_mntns):
+ chcontext(ref_ns+'mnt')
proc_mounted = False
- if (not os.access('/proc/self',0)):
+ if (not os.access('/proc/self', 0)):
proc_mounted = True
setns.proc_mount()
for (sysctl_file, sysctl_name, sysctl_val) in sysctls:
- for fn in ["/sbin/sysctl", "/usr/sbin/sysctl", "/bin/sysctl", "/usr/bin/sysctl"]:
- if os.path.exists(fn):
- os.system("mount -o remount,rw none /proc/sys")
- os.system('%s -w %s=%s'%(fn, sysctl_name,sysctl_val))
- os.system("mount -o remount,ro none /proc/sys")
- break
- else:
- print "Error: image does not have a sysctl binary"
+ for fn in ["/sbin/sysctl", "/usr/sbin/sysctl", "/bin/sysctl", "/usr/bin/sysctl"]:
+ if os.path.exists(fn):
+ os.system('%s -w %s=%s >/dev/null 2>&1' %
+ (fn, sysctl_name, sysctl_val))
+ break
+ else:
+ print("Error: image does not have a sysctl binary")
# cgroups is not yet LXC-safe, so we need to use the coarse 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)
+ for subsystem in ['cpuset', 'cpu,cpuacct', 'memory', 'devices', 'freezer', 'net_cls', 'blkio', 'perf_event', 'systemd']:
+ fs_path = '/sys/fs/cgroup/%s' % subsystem
+ if (not umount(fs_path, '-l')):
+ print('WARNING - umount failed (ignored) with path=', fs_path)
+ pass
+ # Leaving these comments for historical reference
+ # print "Error disabling cgroup access"
+ # exit(1) - Don't need this because failure here implies failure in the call to umount /sys/fs/cgroup
if (not umount('/sys/fs/cgroup')):
- print "Error disabling cgroup access"
+ print("Error disabling cgroup access")
exit(1)
- pid = os.fork()
-
- # capsh has a --user option starting with f14
- # so if only for f12 we need to fake this one
- #
- # capsh.c does essentially the following when invoked with --user:
- # pwd = getpwnam(user); ...
- # ngroups = MAX_GROUPS;
- # status = getgrouplist(user, pwd->pw_gid, groups, &ngroups); ...
- # status = setgroups(ngroups, groups); ...
- # status = setgid(pwd->pw_gid); ...
- # status = setuid(pwd->pw_uid); ...
- # however we cannot simulate that ourselves because if we did in this process then
- # capsh could not be allowed to mess with caps any more
-
- def getuid (slicename):
- import pwd
- try:
- return pwd.getpwnam(slicename).pw_uid
- except:
- return
-
- if (pid == 0):
- cap_arg = '--drop='+drop_capabilities
+ fork_pid = os.fork()
+ if (fork_pid == 0):
if (not args.root):
+ setns.drop_caps()
if (args.nosliceuid):
# we still want to drop capabilities, but don't want to switch UIDs
- exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--','--login',]+args.command_to_run
+ exec_args = [arch, '/bin/sh', '--login', ]+args.command_to_run
else:
- uid = getuid (slice_name)
- if not uid:
- print "lxcsu could not spot %s in /etc/passwd - exiting"%slice_name
+ if not slice_uid:
+ print("lxcsu could not spot %s in /etc/passwd - exiting" %
+ slice_name)
exit(1)
- exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--uid=%s'%uid,'--','--login',]+args.command_to_run
+ exec_args = [arch, '/usr/bin/sudo', '-u', slice_name,
+ '/bin/sh', '--login', ]+args.command_to_run
# once we can drop f12, it would be nicer to instead go for
-# exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--user=%s'%slice_name,'--','--login',]+args.command_to_run
+# exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--user=%s'%slice_name,'--login',]+args.command_to_run
else:
- exec_args = [arch,'/usr/sbin/capsh','--','--login']+args.command_to_run
+ exec_args = [arch, '/bin/sh', '--login']+args.command_to_run
os.environ['SHELL'] = '/bin/sh'
- os.environ['HOME'] = '/home/%s'%slice_name
- os.environ['LD_PRELOAD'] = '/etc/planetlab/lib/bind_public.so'
- os.chdir("/home/%s"%(slice_name))
- if debug: print 'lxcsu:execv:','/usr/bin/setarch',exec_args
- os.execv('/usr/bin/setarch',exec_args)
+ if os.path.exists('/etc/planetlab/lib/bind_public.so'):
+ os.environ['LD_PRELOAD'] = '/etc/planetlab/lib/bind_public.so'
+ if not args.noslicehome:
+ os.environ['HOME'] = '/home/%s' % slice_name
+ os.chdir("/home/%s" % (slice_name))
+ if debug:
+ print('lxcsu:execv:', '/usr/bin/setarch', exec_args)
+ os.execv('/usr/bin/setarch', exec_args)
else:
setns.proc_umount()
- _,status = os.waitpid(pid,0)
+ _, status = os.waitpid(fork_pid, 0)
exit(os.WEXITSTATUS(status))
+
if __name__ == '__main__':
main()
git://git.onelab.eu / lxc-userspace.git / blobdiff