#!/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()
classlines = [x for x in output if ('Class' in x.split(':')[0])]
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 ("slice",dest="slice_name",nargs=1)
-
- options = parser.parse_args()
- slice_name=options.slice_name
+ 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 ("slice_name")
+ parser.add_argument ("command_to_run",nargs="*")
+
+ 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
+
+ # 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' ] + 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
slice_spec = None
- # xxx fixme xxx - provide a default as this is not always properly computed
- arch = 'x86_64'
+ # provide a default as this is not always properly computed
+ arch = None
for e in output:
try:
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'):
+ if (cmdline == '/sbin/init') or (cmdline.startswith("init [")):
slice_spec = slice_path
arch = getarch('/proc/%s/exe'%pid)
break
- except:
- 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'
+
+ # 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:
for subsystem in ['cpuset','memory','blkio']:
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):
- open('/proc/lxcsu','w').write(pid)
-
- if (not options.pidns):
- open('/proc/pidsu','w').write(pid)
-
- # cgroups is not yet LXC-safe, so we need to use the course grained access control
+ if (not args.mntns):
+ setns.chcontext('/proc/%s/ns/mnt'%pid)
+
+ 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("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"
+
+ # 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']+args[1:]
+ if (not args.root):
+ 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']+args[1:]
+ exec_args = [arch,'/usr/sbin/capsh','--','--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)
else:
+ setns.proc_umount()
_,status = os.waitpid(pid,0)
exit(os.WEXITSTATUS(status))
git://git.onelab.eu / lxc-userspace.git / blobdiff