[PATCHv2 5/6] useradd-staticids.bbclass: Read passwd/group files before parsing

Peter Kjellerstedt
2015-12-18T23:54:05Z

Read and merge the passwd/group files before parsing the user and
group definitions. This means they will only be read once per
recipe. This solves a problem where if a user was definied in multiple
files, it could generate group definitions for groups that should not
be created. E.g., if the first passwd file read defines a user as:

foobar::1234::::

and the second passwd file defines it as:

foobar:::nogroup:The foobar user:/:/bin/sh

then a foobar group would be created even if the user will use the
nogroup as its primary group.

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
---
meta/classes/useradd-staticids.bbclass | 164 ++++++++++++++++++---------------
1 file changed, 91 insertions(+), 73 deletions(-)

diff --git a/meta/classes/useradd-staticids.bbclass b/meta/classes/useradd-staticids.bbclass
index df4902e..4e0ab1b 100644
--- a/meta/classes/useradd-staticids.bbclass
+++ b/meta/classes/useradd-staticids.bbclass
@@ -22,6 +22,30 @@ def update_useradd_static_config(d):
and return it as a list"""
return list(itertools.islice(itertools.chain(iterable, itertools.repeat(obj)), length))

+ def merge_files(file_list, exp_fields):
+ """Read each passwd/group file in file_list, split each line and create
+ a dictionary with the user/group names as keys and the split lines as
+ values. If the user/group name already exists in the dictionary, then
+ update any fields in the list with the values from the new list (if they
+ are set)."""
+ id_table = dict()
+ for conf in file_list.split():
+ if os.path.exists(conf):
+ f = open(conf, "r")
+ for line in f:
+ if line.startswith('#'):
+ continue
+ # Make sure there always are at least exp_fields elements in
+ # the field list. This allows for leaving out trailing
+ # colons in the files.
+ fields = list_extend(line.rstrip().split(":"), exp_fields)
+ if fields[0] not in id_table:
+ id_table[fields[0]] = fields
+ else:
+ id_table[fields[0]] = list(itertools.imap(lambda x, y: x or y, fields, id_table[fields[0]]))
+
+ return id_table
+
# We parse and rewrite the useradd components
def rewrite_useradd(params):
# The following comes from --help on useradd from shadow
@@ -63,6 +87,7 @@ def update_useradd_static_config(d):
return str

newparams = []
+ users = None
for param in re.split('''[ \t]*;[ \t]*(?=(?:[^'"]|'[^']*'|"[^"]*")*$)''', params):
param = param.strip()
if not param:
@@ -72,10 +97,9 @@ def update_useradd_static_config(d):
except:
raise bb.build.FuncFailed("%s: Unable to parse arguments for USERADD_PARAM_%s: '%s'" % (d.getVar('PN', True), pkg, param))

- # files/passwd or the contents of USERADD_UID_TABLES
+ # Read all passwd files specified in USERADD_UID_TABLES or files/passwd
# Use the standard passwd layout:
# username:password:user_id:group_id:comment:home_directory:login_shell
- # (we want to process in reverse order, as 'last found' in the list wins)
#
# If a field is left blank, the original value will be used. The 'username'
# field is required.
@@ -84,61 +108,57 @@ def update_useradd_static_config(d):
# in the useradd command may introduce a security hole. It's assumed that
# all new users get the default ('*' which prevents login) until the user is
# specifically configured by the system admin.
- for conf in get_passwd_list(d).split()[::-1]:
- if os.path.exists(conf):
- f = open(conf, "r")
- for line in f:
- if line.startswith('#'):
- continue
- # Make sure there always are at least seven elements in
- # the field list. This allows for leaving out trailing
- # colons in the passwd file.
- field = list_extend(line.rstrip().split(":"), 7)
- if field[0] == uaargs.LOGIN:
- if uaargs.uid and field[2] and (uaargs.uid != field[2]):
- bb.warn("%s: Changing username %s's uid from (%s) to (%s), verify configuration files!" % (d.getVar('PN', True), uaargs.LOGIN, uaargs.uid, field[2]))
- uaargs.uid = field[2] or uaargs.uid
-
- # Determine the possible groupname
- # Unless the group name (or gid) is specified, we assume that the LOGIN is the groupname
- #
- # By default the system has creation of the matching groups enabled
- # So if the implicit username-group creation is on, then the implicit groupname (LOGIN)
- # is used, and we disable the user_group option.
- #
- user_group = uaargs.user_group is None or uaargs.user_group is True
- uaargs.groupname = uaargs.LOGIN if user_group else uaargs.gid
- uaargs.groupid = field[3] or uaargs.gid or uaargs.groupname
-
- if uaargs.groupid and uaargs.gid != uaargs.groupid:
- newgroup = None
- if not uaargs.groupid.isdigit():
- # We don't have a group number, so we have to add a name
- bb.debug(1, "Adding group %s!" % uaargs.groupid)
- newgroup = "%s %s" % (' --system' if uaargs.system else '', uaargs.groupid)
- elif uaargs.groupname and not uaargs.groupname.isdigit():
- # We have a group name and a group number to assign it to
- bb.debug(1, "Adding group %s (gid %s)!" % (uaargs.groupname, uaargs.groupid))
- newgroup = "-g %s %s" % (uaargs.groupid, uaargs.groupname)
- else:
- # We want to add a group, but we don't know it's name... so we can't add the group...
- # We have to assume the group has previously been added or we'll fail on the adduser...
- # Note: specifying the actual gid is very rare in OE, usually the group name is specified.
- bb.warn("%s: Changing gid for login %s to %s, verify configuration files!" % (d.getVar('PN', True), uaargs.LOGIN, uaargs.groupid))
-
- uaargs.gid = uaargs.groupid
- uaargs.user_group = None
- if newgroup:
- groupadd = d.getVar("GROUPADD_PARAM_%s" % pkg, True)
- if groupadd:
- d.setVar("GROUPADD_PARAM_%s" % pkg, "%s ; %s" % (groupadd, newgroup))
- else:
- d.setVar("GROUPADD_PARAM_%s" % pkg, newgroup)
-
- uaargs.comment = "'%s'" % field[4] if field[4] else uaargs.comment
- uaargs.home_dir = field[5] or uaargs.home_dir
- uaargs.shell = field[6] or uaargs.shell
- break
+ if not users:
+ users = merge_files(get_passwd_list(d), 7)
+
+ if uaargs.LOGIN not in users:
+ continue
+
+ field = users[uaargs.LOGIN]
+
+ if uaargs.uid and field[2] and (uaargs.uid != field[2]):
+ bb.warn("%s: Changing username %s's uid from (%s) to (%s), verify configuration files!" % (d.getVar('PN', True), uaargs.LOGIN, uaargs.uid, field[2]))
+ uaargs.uid = field[2] or uaargs.uid
+
+ # Determine the possible groupname
+ # Unless the group name (or gid) is specified, we assume that the LOGIN is the groupname
+ #
+ # By default the system has creation of the matching groups enabled
+ # So if the implicit username-group creation is on, then the implicit groupname (LOGIN)
+ # is used, and we disable the user_group option.
+ #
+ user_group = uaargs.user_group is None or uaargs.user_group is True
+ uaargs.groupname = uaargs.LOGIN if user_group else uaargs.gid
+ uaargs.groupid = field[3] or uaargs.gid or uaargs.groupname
+
+ if uaargs.groupid and uaargs.gid != uaargs.groupid:
+ newgroup = None
+ if not uaargs.groupid.isdigit():
+ # We don't have a group number, so we have to add a name
+ bb.debug(1, "Adding group %s!" % uaargs.groupid)
+ newgroup = "%s %s" % (' --system' if uaargs.system else '', uaargs.groupid)
+ elif uaargs.groupname and not uaargs.groupname.isdigit():
+ # We have a group name and a group number to assign it to
+ bb.debug(1, "Adding group %s (gid %s)!" % (uaargs.groupname, uaargs.groupid))
+ newgroup = "-g %s %s" % (uaargs.groupid, uaargs.groupname)
+ else:
+ # We want to add a group, but we don't know it's name... so we can't add the group...
+ # We have to assume the group has previously been added or we'll fail on the adduser...
+ # Note: specifying the actual gid is very rare in OE, usually the group name is specified.
+ bb.warn("%s: Changing gid for login %s to %s, verify configuration files!" % (d.getVar('PN', True), uaargs.LOGIN, uaargs.groupid))
+
+ uaargs.gid = uaargs.groupid
+ uaargs.user_group = None
+ if newgroup:
+ groupadd = d.getVar("GROUPADD_PARAM_%s" % pkg, True)
+ if groupadd:
+ d.setVar("GROUPADD_PARAM_%s" % pkg, "%s ; %s" % (groupadd, newgroup))
+ else:
+ d.setVar("GROUPADD_PARAM_%s" % pkg, newgroup)
+
+ uaargs.comment = "'%s'" % field[4] if field[4] else uaargs.comment
+ uaargs.home_dir = field[5] or uaargs.home_dir
+ uaargs.shell = field[6] or uaargs.shell

# Should be an error if a specific option is set...
if d.getVar('USERADD_ERROR_DYNAMIC', True) == '1' and not ((uaargs.uid and uaargs.uid.isdigit()) and uaargs.gid):
@@ -200,6 +220,7 @@ def update_useradd_static_config(d):
return str

newparams = []
+ groups = None
for param in re.split('''[ \t]*;[ \t]*(?=(?:[^'"]|'[^']*'|"[^"]*")*$)''', params):
param = param.strip()
if not param:
@@ -210,7 +231,7 @@ def update_useradd_static_config(d):
except:
raise bb.build.FuncFailed("%s: Unable to parse arguments for GROUPADD_PARAM_%s: '%s'" % (d.getVar('PN', True), pkg, param))

- # Need to iterate over layers and open the right file(s)
+ # Read all group files specified in USERADD_GID_TABLES or files/group
# Use the standard group layout:
# groupname:password:group_id:group_members
#
@@ -219,21 +240,18 @@ def update_useradd_static_config(d):
#
# Note: similar to the passwd file, the 'password' filed is ignored
# Note: group_members is ignored, group members must be configured with the GROUPMEMS_PARAM
- for conf in get_group_list(d).split()[::-1]:
- if os.path.exists(conf):
- f = open(conf, "r")
- for line in f:
- if line.startswith('#'):
- continue
- # Make sure there always are at least four elements in
- # the field list. This allows for leaving out trailing
- # colons in the group file.
- field = list_extend(line.rstrip().split(":"), 4)
- if field[0] == gaargs.GROUP and field[2]:
- if gaargs.gid and (gaargs.gid != field[2]):
- bb.warn("%s: Changing groupname %s's gid from (%s) to (%s), verify configuration files!" % (d.getVar('PN', True), gaargs.GROUP, gaargs.gid, field[2]))
- gaargs.gid = field[2]
- break
+ if not groups:
+ groups = merge_files(get_group_list(d), 4)
+
+ if gaargs.GROUP not in groups:
+ continue
+
+ field = groups[gaargs.GROUP]
+
+ if field[2]:
+ if gaargs.gid and (gaargs.gid != field[2]):
+ bb.warn("%s: Changing groupname %s's gid from (%s) to (%s), verify configuration files!" % (d.getVar('PN', True), gaargs.GROUP, gaargs.gid, field[2]))
+ gaargs.gid = field[2]

if d.getVar('USERADD_ERROR_DYNAMIC', True) == '1' and not (gaargs.gid and gaargs.gid.isdigit()):
#bb.error("Skipping recipe %s, package %s which adds groupname %s does not have a static gid defined." % (d.getVar('PN', True), pkg, gaargs.GROUP))
--
2.1.0