#!/usr/bin/python
-
-import setns
-import os
import sys
+import os
+import setns
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]
def umount(fs_dir):
output = os.popen('/bin/umount %s 2>&1'%fs_dir).read()
- return ('device is busy' not in fs_dir)
+ return ('device is busy' not in output)
def main ():
parser = ArgumentParser()
parser.add_argument("-r", "--root",
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")
+ 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
+
+ # 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 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
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_path = path
pid = slice_path.split('/')[2]
cmdline = open('/proc/%s/cmdline'%pid).read().rstrip('\n\x00')
- if (cmdline == '/sbin/init'):
+ if (cmdline == '/sbin/init') or (cmdline.startswith("init [")):
slice_spec = slice_path
arch = getarch('/proc/%s/exe'%pid)
- if debug: print "setting arch",arch
break
except Exception,e:
if debug:
if arch is None:
arch = 'x86_64'
- if debug: print "WARNING: setting arch to default x86_64"
+
+ # 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))
# Enter cgroups
try:
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 options.netns):
+ if (not args.netns):
setns.chcontext('/proc/%s/ns/net'%pid)
- if (not options.mntns):
+ if (not args.mntns):
setns.chcontext('/proc/%s/ns/mnt'%pid)
- if (not options.pidns):
- setns.chcontext('/proc/%s/ns/pid'%pid)
-
+ proc_mounted = False
if (not os.access('/proc/self',0)):
+ proc_mounted = True
setns.proc_mount()
- # cgroups is not yet LXC-safe, so we need to use the course grained access control
+ 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'%(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
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))
git://git.onelab.eu / lxc-userspace.git / blobdiff