#!/usr/bin/python
-
-import setns
-import os
import sys
+import os
+import setns
+import pdb
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()
- 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]
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 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)
+ 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,
- help="Don't enter network namespace")
+ 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")
+ 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")
+ 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")
+ action="store_true", dest="root", default=False,
+ help="Enter as root: be careful")
+ 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",
- action='store_true', dest='debug', default=False,
- help="debug option")
+ action='store_true', dest='debug', default=False,
+ help="debug option")
+ 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("-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="*")
- options = parser.parse_args()
- slice_name=options.slice_name
- global debug
- debug=options.debug
+ args = parser.parse_args()
+ slice_name=args.slice_name
- 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)
+ # 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
- slice_spec = None
+ 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
- # provide a default as this is not always properly computed
- arch = None
+ # 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)]
- 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
+ # 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 slice_spec or not pid):
- print "Not started: %s"%slice_name
- exit(1)
+ try:
+ cmd = '/usr/bin/virsh --connect lxc:/// domid %s'%slice_name
+ pidnum = int(os.popen(cmd).read().rstrip())
+ except:
+ print "Domain %s not found"%slice_name
+ exit(1)
- if arch is None:
- arch = 'x86_64'
- if debug: print "WARNING: setting arch to default x86_64"
+ 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)
- # 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()))
+ if (not pid):
+ print "Domain %s not started"%slice_name
+ exit(1)
- except:
- print "Error assigning resources: %s"%slice_name
- exit(1)
+ if arch is None:
+ arch = 'x86_64'
- 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)
+ # Set sysctls specific to slice
+ sysctls = []
+ 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_name = e[len(prefix):]
+ sysctl_val = open(sysctl_file).read()
+ sysctls.append((sysctl_file, sysctl_name, sysctl_val))
+
+ subdirs = get_cgroup_subdirs_for_pid(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)
+ # Enter cgroups
+ current_cgroup = ''
+ for subsystem in ['cpuset','memory','blkio','cpuacct','cpuacct,cpu','freezer']:
+ try:
+ current_cgroup = subsystem
- setns.chcontext('/proc/%s/ns/uts'%pid)
- setns.chcontext('/proc/%s/ns/ipc'%pid)
+ # 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,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')
- if (not options.netns):
- setns.chcontext('/proc/%s/ns/net'%pid)
+ f.write(str(os.getpid()))
+ if (subsystem=='freezer'):
+ f.close()
- if (not options.mntns):
- open('/proc/lxcsu','w').write(pid)
+ except Exception,e:
+ if (not subdirs.has_key(subsystem)):
+ pass
+ else:
+ if debug: print e
+ print "Error assigning cgroup %s (%s) for slice %s"%(current_cgroup,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
+
+ chcontext('/proc/%s/ns/uts'%pid)
+ chcontext('/proc/%s/ns/ipc'%pid)
+
+ if (not args.pidns):
+ chcontext('/proc/%s/ns/pid'%pid)
+
+ if (not args.netns):
+ chcontext('/proc/%s/ns/net'%pid)
- if (not options.pidns):
- open('/proc/pidsu','w').write(pid)
+ if (not args.mntns):
+ chcontext('/proc/%s/ns/mnt'%pid)
- # cgroups is not yet LXC-safe, so we need to use the course grained access control
+ proc_mounted = False
+ 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('%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"
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
- if (not options.root):
- exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--','--login']+options.command_to_run
+ if (not args.root):
+ 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
+ else:
+ uid = getuid (slice_name)
+ if not 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
+# 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
else:
- exec_args = [arch,'/usr/sbin/capsh','--','--login']+options.command_to_run
+ exec_args = [arch,'/usr/sbin/capsh','--','--login']+args.command_to_run
- if debug:
- print "exec'ing"
- for arg in exec_args: print ">%s<"%arg
os.environ['SHELL'] = '/bin/sh'
+ 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)
exit(os.WEXITSTATUS(status))
if __name__ == '__main__':
- main()
+ main()
git://git.onelab.eu / lxc-userspace.git / blobdiff