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
-#################### should go into a separate libvirtsystemd.py
-# but we want to keep packaging simple for now
-
-# reproducing libvirt's systemd-oriented escaping mechanism
-# http://code.metager.de/source/xref/lib/virt/src/util/virsystemd.c
-# (see original code at the end of this file)
-
-def virSystemdEscapeName (name):
- result=''
- def ESCAPE(c,s):
- # replace hex's output '0x..' into '\x..'
- return s+hex(ord(c)).replace('0','\\',1)
- VALID_CHARS = \
- "0123456789" + \
- "abcdefghijklmnopqrstuvwxyz" + \
- "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + \
- ":-_.\\"
- for c in name:
- if c=='/':
- result += '-'
- elif c in '-\\' or c not in VALID_CHARS:
- result=ESCAPE(c,result)
- else:
- result += c
- return result
-
-#35static void virSystemdEscapeName(virBufferPtr buf,
-#36 const char *name)
-#37{
-#38 static const char hextable[16] = "0123456789abcdef";
-#39
-#40#define ESCAPE(c) \
-#41 do { \
-#42 virBufferAddChar(buf, '\\'); \
-#43 virBufferAddChar(buf, 'x'); \
-#44 virBufferAddChar(buf, hextable[(c >> 4) & 15]); \
-#45 virBufferAddChar(buf, hextable[c & 15]); \
-#46 } while (0)
-#47
-#48#define VALID_CHARS \
-#49 "0123456789" \
-#50 "abcdefghijklmnopqrstuvwxyz" \
-#51 "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
-#52 ":-_.\\"
-#53
-#54 if (*name == '.') {
-#55 ESCAPE(*name);
-#56 name++;
-#57 }
-#58
-#59 while (*name) {
-#60 if (*name == '/')
-#61 virBufferAddChar(buf, '-');
-#62 else if (*name == '-' ||
-#63 *name == '\\' ||
-#64 !strchr(VALID_CHARS, *name))
-#65 ESCAPE(*name);
-#66 else
-#67 virBufferAddChar(buf, *name);
-#68 name++;
-#69 }
-#70
-#71#undef ESCAPE
-#72#undef VALID_CHARS
-#73}
-
-def virSystemdMakeScopeName (name, drivername, partition):
- result=''
- result += virSystemdEscapeName (partition)
- result += '-'
- result += virSystemdEscapeName (drivername)
- result += '\\x2d'
- result += virSystemdEscapeName (name)
- result += '.scope'
- return result
-
-#76char *virSystemdMakeScopeName(const char *name,
-#77 const char *drivername,
-#78 const char *partition)
-#79{
-#80 virBuffer buf = VIR_BUFFER_INITIALIZER;
-#81
-#82 if (*partition == '/')
-#83 partition++;
-#84
-#85 virSystemdEscapeName(&buf, partition);
-#86 virBufferAddChar(&buf, '-');
-#87 virSystemdEscapeName(&buf, drivername);
-#88 virBufferAddLit(&buf, "\\x2d");
-#89 virSystemdEscapeName(&buf, name);
-#90 virBufferAddLit(&buf, ".scope");
-#91
-#92 if (virBufferError(&buf)) {
-#93 virReportOOMError();
-#94 return NULL;
-#95 }
-#96
-#97 return virBufferContentAndReset(&buf);
-#98}
-
-### our own additions
-import os.path
-def find_first_dir (candidates):
- for candidate in candidates:
- if os.path.isdir(candidate): return candidate
- raise Exception,"Cannot find valid dir among %s"%'\n'.join(candidates)
-
-def find_sysfs_scope (subsystem, slice_name):
- subsystem1=subsystem
- subsystem2=subsystem
- if subsystem=='cpuacct':
- subsystem2='cpu,cpuacct'
- candidates = [
- # for f16 and our locally brewed libvirt 1.0.4
- "/sys/fs/cgroup/%s/libvirt/lxc/%s"%(subsystem1, slice_name),
- # f20 and libvirt 1.1.3
- "/sys/fs/cgroup/%s/machine.slice/%s"%(subsystem2,
- virSystemdMakeScopeName(slice_name,'lxc','machine')),
- ]
- return find_first_dir (candidates)
-
-#################### end of libvirtsystemd.py
-
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])]
else:
raise Exception('Could not determine architecture')
+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,
+ 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,
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 child_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
+ # they chould be changed as well
+
except:
- print "Error finding slice %s"%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 "Not started: %s"%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
+ # xxx probably init_pid here too
+ arch = getarch('/proc/%s/exe'%driver_pid)
# Set sysctls specific to slice
sysctls = []
sysctl_val = open(sysctl_file).read()
sysctls.append((sysctl_file, sysctl_name, sysctl_val))
- # Enter cgroups
- try:
- for subsystem in ['cpuset','memory','blkio']:
- open( find_sysfs_scope (subsystem, slice_name)+"/tasks", 'w').write(str(os.getpid()))
-
- except Exception,e:
- if debug: print e
- print "Error assigning resources: %s"%slice_name
- exit(1)
-
- try:
- open ( find_sysfs_scope ('cpuacct', slice_name)+"/tasks", 'w').write(str(os.getpid()))
- except Exception,e:
- if debug: print e
- print "Error assigning cpuacct: %s" % slice_name
- exit(1)
+ # 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
# 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( find_sysfs_scope ('freezer', slice_name)+"/tasks", '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 Exception,e:
- if debug: print e
- 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
+
+ # 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')
+
+ f.write(str(os.getpid()))
+ if (subsystem=='freezer'):
+ f.close()
+
+ except Exception,e:
+ if (not subdirs.has_key(subsystem)):
+ pass
+ else:
+ if debug: print e
+ print "Error assigning cgroup %s (pid=%s) for slice %s"%(current_cgroup,driver_pid, slice_name)
+ exit(1)
- 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 args.netns):
- setns.chcontext('/proc/%s/ns/net'%pid)
+ def chcontext (path):
+ retcod = setns.chcontext (path)
+ if retcod != 0:
+ print 'WARNING - setns(%s)=>%s (ignored)'%(path,retcod)
+ return retcod
- if (not args.mntns):
- setns.chcontext('/proc/%s/ns/mnt'%pid)
+ # Use init_pid and not driver_pid to locate reference namespaces
+ ref_ns = "/proc/%s/ns/"%init_pid
+
+ if True: chcontext(ref_ns+'uts')
+ if True: chcontext(ref_ns+'ipc')
+
+ 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)):
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"
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
+ fork_pid = os.fork()
def getuid (slicename):
import pwd
except:
return
- if (pid == 0):
- cap_arg = '--drop='+drop_capabilities
-
+ 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
exit(1)
- exec_args = [arch,'/usr/sbin/capsh',cap_arg,'--uid=%s'%uid,'--','--login',]+args.command_to_run
+ exec_args = [arch,'/bin/sh','--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
+# 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'):
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