-#!/usr/bin/python
+#!/usr/bin/python3
import sys
import os
import setns
-import pdb
+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, e:
- print "Error reading cgroup info: %s"%str(e)
+ except Exception as e:
+ print("Error reading cgroup info: %s"%str(e))
pass
-
+
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 ():
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,
args = parser.parse_args()
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 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
-
try:
cmd = '/usr/bin/virsh --connect lxc:/// domid %s'%slice_name
- pidnum = int(os.popen(cmd).read().rstrip())
+ # 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 "Domain %s not found"%slice_name
+ print("Domain %s not found"%slice_name)
exit(1)
- pid = '%s'%pidnum
- if debug: print "Found pidnum",pidnum
- cmdline = open('/proc/%s/cmdline'%pidnum).read().rstrip('\n\x00')
- arch = getarch('/proc/%s/exe'%pid)
-
- if (not pid):
- print "Domain %s not started"%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_val = open(sysctl_file).read()
sysctls.append((sysctl_file, sysctl_name, sysctl_val))
- subdirs = get_cgroup_subdirs_for_pid(pid)
+ # 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
subsystem_comps.reverse()
subsystem_alt = ','.join(subsystem_comps)
tasks_path_alt = [sysfs_root, subsystem_alt, subdirs[subsystem], 'tasks']
- except Exception,e:
+ 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:
if (subsystem=='freezer'):
f.close()
- except Exception,e:
- if (not subdirs.has_key(subsystem)):
+ except Exception as e:
+ if (subsystem not in subdirs):
pass
else:
- if debug: print e
- print "Error assigning cgroup %s (%s) for slice %s"%(current_cgroup,pid, slice_name)
+ 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)
+ print('WARNING - setns(%s)=>%s (ignored)'%(path,retcod))
return retcod
- chcontext('/proc/%s/ns/uts'%pid)
- chcontext('/proc/%s/ns/ipc'%pid)
-
- if (not args.pidns):
- chcontext('/proc/%s/ns/pid'%pid)
+ # Use init_pid and not driver_pid to locate reference namespaces
+ ref_ns = "/proc/%s/ns/"%init_pid
- if (not args.netns):
- chcontext('/proc/%s/ns/net'%pid)
+ if True: chcontext(ref_ns+'uts')
+ if True: chcontext(ref_ns+'ipc')
- if (not args.mntns):
- chcontext('/proc/%s/ns/mnt'%pid)
+ 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)):
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"
+ 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
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
+ 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'
if os.path.exists('/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
+ 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__':
git://git.onelab.eu / lxc-userspace.git / blobdiff