X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lxcsu;h=97600cf6b4b60ee7f68c3e9da93585554eb4d089;hb=5851c34c3ae60491401eed467fcc39273c0b738e;hp=ea63d1822234e6c9f2505c6983bf631aabf1cf49;hpb=5890874ae327145958ce7ad96ddc83441823ffb4;p=lxc-userspace.git diff --git a/lxcsu b/lxcsu index ea63d18..97600cf 100644 --- a/lxcsu +++ b/lxcsu @@ -3,72 +3,151 @@ import setns import os +import sys from optparse import OptionParser -drop_capabilities='cap_sys_admin,cap_net_admin,cap_sys_boot,cap_sys_module'.split(',') +drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module' + +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])] + line = classlines[0] + c = line.split(':')[1] + if ('ELF64' in c): + return 'x86_64' + elif ('ELF32' in c): + return 'i686' + 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) parser = OptionParser() -parser.add_option("-n", "--net", +parser.add_option("-n", "--nonet", action="store_true", dest="netns", default=False, - help="Enter network namespace") -parser.add_option("-m", "--mnt", + help="Don't enter network namespace") +parser.add_option("-m", "--nomnt", action="store_true", dest="mntns", default=False, - help="Enter mount namespace") -parser.add_option("-p", "--pid", + help="Don't enter mount namespace") +parser.add_option("-p", "--nopid", action="store_true", dest="pidns", default=False, - help="Enter pid namespace") + help="Don't enter pid namespace") +parser.add_option("-r", "--root", + action="store_true", dest="root", default=False, + help="Enter as root: be careful") (options, args) = parser.parse_args() try: - slice_name = args[0] + slice_name = args[0] except IndexError: - print "You must specify a vm name" - exit(1) + print "You must specify a vm name" + exit(1) try: - cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name - output = os.popen(cmd).readlines() + cmd = 'grep %s /proc/*/cgroup | grep freezer'%slice_name + output = os.popen(cmd).readlines() except: - print "Error finding slice %s"%slice_name - exit(1) + print "Error finding slice %s"%slice_name + exit(1) slice_spec = None + +# xxx fixme xxx - provide a default as this is not always properly computed +arch = 'x86_64' + for e in output: - try: - l = e.rstrip() - path = l.split(':')[0] - comp = l.rsplit(':')[-1] - slice_name_check = comp.rsplit('/')[-1] - - if (slice_name_check == 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 - break - except: - break + try: + l = e.rstrip() + path = l.split(':')[0] + comp = l.rsplit(':')[-1] + slice_name_check = comp.rsplit('/')[-1] + + if (slice_name_check == 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) + break + except: + break if (not slice_spec or not pid): print "Not started: %s"%slice_name exit(1) -r1 = setns.chcontext('/proc/%s/ns/utc'%pid) -r2 = setns.chcontext('/proc/%s/ns/ipc'%pid) -path = '/proc/%s/ns/net'%pid -r3 = setns.chcontext(path) +# 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) + +# 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 options.netns): + setns.chcontext('/proc/%s/ns/net'%pid) -open('/proc/lxcsu','w').write(pid) -open('/proc/pidsu','w').write(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 +# 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) + +if (not umount('/sys/fs/cgroup')): + print "Error disabling cgroup access" + exit(1) pid = os.fork() -cap_args = map(lambda c:'--drop='+c, drop_capabilities) - if (pid == 0): - os.execv('/usr/sbin/capsh',cap_args+['--']) + cap_arg = '--drop='+drop_capabilities + + if (not options.root): + exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--','--login']+args[1:] + else: + exec_args = [arch,'/usr/sbin/capsh','--','--login']+args[1:] + + os.environ['SHELL'] = '/bin/sh' + os.execv('/usr/bin/setarch',exec_args) else: - os.waitpid(pid,0) + _,status = os.waitpid(pid,0) + exit(os.WEXITSTATUS(status))