selinux-refpolicy/support/genhomedircon.py
Adam Duskett 6c9cc47e6c fix regex escape sequence error.
python3.6 will error out with the message "invalid escape sequence"
in genhomedircon.py.  This patch fixes these errors by turning the string
in the into a raw string.
2017-10-10 18:00:30 -04:00

495 lines
17 KiB
Python

#!/usr/bin/env python3
# Copyright (C) 2004 Tresys Technology, LLC
# see file 'COPYING' for use and warranty information
#
# genhomedircon - this script is used to generate file context
# configuration entries for user home directories based on their
# default roles and is run when building the policy. Specifically, we
# replace HOME_ROOT, HOME_DIR, and ROLE macros in .fc files with
# generic and user-specific values.
#
# Based off original script by Dan Walsh, <dwalsh@redhat.com>
#
# ASSUMPTIONS:
#
# The file CONTEXTDIR/files/homedir_template exists. This file is used to
# set up the home directory context for each real user.
#
# If a user has more than one role in CONTEXTDIR/local.users, genhomedircon uses
# the first role in the list.
#
# If a user is not listed in CONTEXTDIR/local.users, he will default to user_u, role user
#
# "Real" users (as opposed to system users) are those whose UID is greater than
# or equal STARTING_UID (usually 500) and whose login is not a member of
# EXCLUDE_LOGINS. Users who are explicitly defined in CONTEXTDIR/local.users
# are always "real" (including root, in the default configuration).
#
#
# Old ASSUMPTIONS:
#
# If a user has more than one role in FILECONTEXTDIR/users, genhomedircon uses
# the first role in the list.
#
# If a user is not listed in FILECONTEXTDIR/users, genhomedircon assumes that
# the user's home dir will be found in one of the HOME_ROOTs.
#
# "Real" users (as opposed to system users) are those whose UID is greater than
# or equal STARTING_UID (usually 500) and whose login is not a member of
# EXCLUDE_LOGINS. Users who are explicitly defined in FILECONTEXTDIR/users
# are always "real" (including root, in the default configuration).
#
import sys, os, pwd, getopt, re
EXCLUDE_LOGINS=["/sbin/nologin", "/bin/false"]
# Python 2/3 wrapper
def getstatusoutput_wrapper(cmd):
if sys.version_info.major is 2:
import commands
return commands.getstatusoutput(cmd)
elif sys.version_info.major is 3:
import subprocess
return subprocess.getstatusoutput(cmd)
else:
print("Unsupported Python major version: " + sys.version_info.major)
exit(1)
def getStartingUID():
starting_uid = 99999
rc=getstatusoutput_wrapper("grep -h '^UID_MIN' /etc/login.defs")
if rc[0] == 0:
uid_min = re.sub("^UID_MIN[^0-9]*", "", rc[1])
#stip any comment from the end of the line
uid_min = uid_min.split("#")[0]
uid_min = uid_min.strip()
if int(uid_min) < starting_uid:
starting_uid = int(uid_min)
rc=getstatusoutput_wrapper("grep -h '^LU_UIDNUMBER' /etc/libuser.conf")
if rc[0] == 0:
lu_uidnumber = re.sub("^LU_UIDNUMBER[^0-9]*", "", rc[1])
#stip any comment from the end of the line
lu_uidnumber = re.sub("[ \t].*", "", lu_uidnumber)
lu_uidnumber = lu_uidnumber.split("#")[0]
lu_uidnumber = lu_uidnumber.strip()
if int(lu_uidnumber) < starting_uid:
starting_uid = int(lu_uidnumber)
if starting_uid == 99999:
starting_uid = 500
return starting_uid
#############################################################################
#
# This section is just for backwards compatability
#
#############################################################################
def getPrefixes():
ulist = pwd.getpwall()
STARTING_UID=getStartingUID()
prefixes = {}
for u in ulist:
if u[2] >= STARTING_UID and \
not u[6] in EXCLUDE_LOGINS and \
u[5] != "/" and \
u[5].count("/") > 1:
prefix = u[5][:u[5].rfind("/")]
if not prefix in prefixes:
prefixes[prefix] = ""
return prefixes
def getUsers(filecontextdir):
rc = getstatusoutput_wrapper("grep ^user %s/users" % filecontextdir)
udict = {}
if rc[0] == 0:
ulist = rc[1].strip().split("\n")
for u in ulist:
user = u.split()
try:
if user[1] == "user_u" or user[1] == "system_u":
continue
# !!! chooses first role in the list to use in the file context !!!
role = user[3]
if role == "{":
role = user[4]
role = role.split("_r")[0]
home = pwd.getpwnam(user[1])[5]
if home == "/":
continue
prefs = {}
prefs["role"] = role
prefs["home"] = home
udict[user[1]] = prefs
except KeyError:
sys.stderr.write("The user \"%s\" is not present in the passwd file, skipping...\n" % user[1])
return udict
def update(filecontext, user, prefs):
rc=getstatusoutput_wrapper("grep -h '^HOME_DIR' %s | grep -v vmware | sed -e 's|HOME_DIR|%s|' -e 's/ROLE/%s/' -e 's/system_u/%s/'" % (filecontext, prefs["home"], prefs["role"], user))
if rc[0] == 0:
print(rc[1])
else:
errorExit("grep/sed error " + rc[1])
return rc
def oldgenhomedircon(filecontextdir, filecontext):
sys.stderr.flush()
if os.path.isdir(filecontextdir) == 0:
sys.stderr.write("New usage is the following\n")
usage()
#We are going to define home directory used by libuser and show-utils as a home directory root
prefixes = {}
rc=getstatusoutput_wrapper("grep -h '^HOME' /etc/default/useradd")
if rc[0] == 0:
homedir = rc[1].split("=")[1]
homedir = homedir.split("#")[0]
homedir = homedir.strip()
if not homedir in prefixes:
prefixes[homedir] = ""
else:
#rc[0] == 256 means the file was there, we read it, but the grep didn't match
if rc[0] != 256:
sys.stderr.write("%s\n" % rc[1])
sys.stderr.write("You do not have access to /etc/default/useradd HOME=\n")
sys.stderr.flush()
rc=getstatusoutput_wrapper("grep -h '^LU_HOMEDIRECTORY' /etc/libuser.conf")
if rc[0] == 0:
homedir = rc[1].split("=")[1]
homedir = homedir.split("#")[0]
homedir = homedir.strip()
homedir = re.sub(r"[^/a-zA-Z0-9].*$", "", homedir)
if not homedir in prefixes:
prefixes[homedir] = ""
#the idea is that we need to find all of the home_root_t directories we do this by just accepting
#any default home directory defined by either /etc/libuser.conf or /etc/default/useradd
#we then get the potential home directory roots from /etc/passwd or nis or wherever and look at
#the defined homedir for all users with UID > STARTING_UID. This list of possible root homedirs
#is then checked to see if it has an explicite context defined in the file_contexts. Explicit
#is any regex that would match it which does not end with .*$ or .+$ since those are general
#recursive matches. We then take any regex which ends with [pattern](/.*)?$ and just check against
#[pattern]
potential_prefixes = getPrefixes()
prefix_regex = {}
#this works by grepping the file_contexts for
# 1. ^/ makes sure this is not a comment
# 2. prints only the regex in the first column first cut on \t then on space
rc=getstatusoutput_wrapper("grep \"^/\" %s | cut -f 1 | cut -f 1 -d \" \" " % (sys.argv[2]) )
if rc[0] == 0:
prefix_regex = rc[1].split("\n")
else:
sys.stderr.write("%s\n" % rc[1])
sys.stderr.write("You do not have access to grep/cut/the file contexts\n")
sys.stderr.flush()
for potential in potential_prefixes.keys():
addme = 1
for regex in prefix_regex:
#match a trailing (/*)? which is actually a bug in rpc_pipefs
regex = re.sub(r"\(/\*\)\?$", "", regex)
#match a trailing .+
regex = re.sub(r"\.+$", "", regex)
#match a trailing .*
regex = re.sub(r"\.\*$", "", regex)
#strip a (/.*)? which matches anything trailing to a /*$ which matches trailing /'s
regex = re.sub(r"\(\/\.\*\)\?", "", regex)
regex = regex + "/*$"
if re.search(regex, potential, 0):
addme = 0
if addme == 1:
if not potential in prefixes:
prefixes[potential] = ""
if prefixes.__eq__({}):
sys.stderr.write("LU_HOMEDIRECTORY not set in /etc/libuser.conf\n")
sys.stderr.write("HOME= not set in /etc/default/useradd\n")
sys.stderr.write("And no users with a reasonable homedir found in passwd/nis/ldap/etc...\n")
sys.stderr.write("Assuming /home is the root of home directories\n")
sys.stderr.flush()
prefixes["/home"] = ""
# There may be a more elegant sed script to expand a macro to multiple lines, but this works
sed_root = "h; s|^HOME_ROOT|%s|" % (prefixes.keys() + "|; p; g; s|^HOME_ROOT|")
sed_dir = "h; s|^HOME_DIR|%s/[^/]+|; s|ROLE_|user_|" % (prefixes.keys() + "/[^/]+|; s|ROLE_|user_|; p; g; s|^HOME_DIR|")
# Fill in HOME_ROOT, HOME_DIR, and ROLE for users not explicitly defined in /etc/security/selinux/src/policy/users
rc=getstatusoutput_wrapper("sed -e \"/^HOME_ROOT/{%s}\" -e \"/^HOME_DIR/{%s}\" %s" % (sed_root, sed_dir, filecontext))
if rc[0] == 0:
print(rc[1])
else:
errorExit("sed error " + rc[1])
users = getUsers(filecontextdir)
print("\n#\n# User-specific file contexts\n#\n")
# Fill in HOME and ROLE for users that are defined
for u in users.keys():
update(filecontext, u, users[u])
#############################################################################
#
# End of backwards compatability section
#
#############################################################################
def getDefaultHomeDir():
ret = []
rc=getstatusoutput_wrapper("grep -h '^HOME' /etc/default/useradd")
if rc[0] == 0:
homedir = rc[1].split("=")[1]
homedir = homedir.split("#")[0]
homedir = homedir.strip()
if not homedir in ret:
ret.append(homedir)
else:
#rc[0] == 256 means the file was there, we read it, but the grep didn't match
if rc[0] != 256:
sys.stderr.write("%s\n" % rc[1])
sys.stderr.write("You do not have access to /etc/default/useradd HOME=\n")
sys.stderr.flush()
rc=getstatusoutput_wrapper("grep -h '^LU_HOMEDIRECTORY' /etc/libuser.conf")
if rc[0] == 0:
homedir = rc[1].split("=")[1]
homedir = homedir.split("#")[0]
homedir = homedir.strip()
if not homedir in ret:
ret.append(homedir)
else:
#rc[0] == 256 means the file was there, we read it, but the grep didn't match
if rc[0] != 256:
sys.stderr.write("%s\n" % rc[1])
sys.stderr.write("You do not have access to /etc/libuser.conf LU_HOMEDIRECTORY=\n")
sys.stderr.flush()
if ret == []:
ret.append("/home")
return ret
def getSELinuxType(directory):
rc=getstatusoutput_wrapper("grep ^SELINUXTYPE= %s/config" % directory)
if rc[0]==0:
return rc[1].split("=")[-1].strip()
return "targeted"
def usage(error = ""):
if error != "":
sys.stderr.write("%s\n" % error)
sys.stderr.write("Usage: %s [ -d selinuxdir ] [-n | --nopasswd] [-t selinuxtype ]\n" % sys.argv[0])
sys.stderr.flush()
sys.exit(1)
def warning(warning = ""):
sys.stderr.write("%s\n" % warning)
sys.stderr.flush()
def errorExit(error):
sys.stderr.write("%s exiting for: " % sys.argv[0])
sys.stderr.write("%s\n" % error)
sys.stderr.flush()
sys.exit(1)
class selinuxConfig:
def __init__(self, selinuxdir="/etc/selinux", setype="targeted", usepwd=1):
self.setype=setype
self.selinuxdir=selinuxdir +"/"
self.contextdir="/contexts"
self.filecontextdir=self.contextdir+"/files"
self.usepwd=usepwd
def getFileContextDir(self):
return self.selinuxdir+self.setype+self.filecontextdir
def getFileContextFile(self):
return self.getFileContextDir()+"/file_contexts"
def getContextDir(self):
return self.selinuxdir+self.setype+self.contextdir
def getHomeDirTemplate(self):
return self.getFileContextDir()+"/homedir_template"
def getHomeRootContext(self, homedir):
rc=getstatusoutput_wrapper("grep HOME_ROOT %s | sed -e \"s|^HOME_ROOT|%s|\"" % ( self.getHomeDirTemplate(), homedir))
if rc[0] == 0:
return rc[1]+"\n"
else:
errorExit("sed error " + rc[1])
def getUsersFile(self):
return self.selinuxdir+self.setype+"/users/local.users"
def getSystemUsersFile(self):
return self.selinuxdir+self.setype+"/users/system.users"
def heading(self):
ret = "\n#\n#\n# User-specific file contexts, generated via %s\n" % sys.argv[0]
ret += "# edit %s to change file_context\n#\n#\n" % self.getUsersFile()
return ret
def getUsers(self):
users=""
rc = getstatusoutput_wrapper('grep "^user" %s' % self.getSystemUsersFile())
if rc[0] == 0:
users+=rc[1]+"\n"
rc = getstatusoutput_wrapper("grep ^user %s" % self.getUsersFile())
if rc[0] == 0:
users+=rc[1]
udict = {}
prefs = {}
if users != "":
ulist = users.split("\n")
for u in ulist:
user = u.split()
try:
if len(user)==0 or user[1] == "user_u" or user[1] == "system_u":
continue
# !!! chooses first role in the list to use in the file context !!!
role = user[3]
if role == "{":
role = user[4]
role = role.split("_r")[0]
home = pwd.getpwnam(user[1])[5]
if home == "/":
continue
prefs = {}
prefs["role"] = role
prefs["home"] = home
udict[user[1]] = prefs
except KeyError:
sys.stderr.write("The user \"%s\" is not present in the passwd file, skipping...\n" % user[1])
return udict
def getHomeDirContext(self, user, home, role):
ret="\n\n#\n# Context for user %s\n#\n\n" % user
rc=getstatusoutput_wrapper("grep '^HOME_DIR' %s | sed -e 's|HOME_DIR|%s|' -e 's/ROLE/%s/' -e 's/system_u/%s/'" % (self.getHomeDirTemplate(), home, role, user))
return ret + rc[1] + "\n"
def genHomeDirContext(self):
users = self.getUsers()
ret=""
# Fill in HOME and ROLE for users that are defined
for u in users.keys():
ret += self.getHomeDirContext (u, users[u]["home"], users[u]["role"])
return ret+"\n"
def checkExists(self, home):
if getstatusoutput_wrapper("grep -E '^%s[^[:alnum:]_-]' %s" % (home, self.getFileContextFile()))[0] == 0:
return 0
#this works by grepping the file_contexts for
# 1. ^/ makes sure this is not a comment
# 2. prints only the regex in the first column first cut on \t then on space
rc=getstatusoutput_wrapper("grep \"^/\" %s | cut -f 1 | cut -f 1 -d \" \" " % self.getFileContextFile() )
if rc[0] == 0:
prefix_regex = rc[1].split("\n")
else:
sys.stderr.write("%s\n" % rc[1])
sys.stderr.write("You do not have access to grep/cut/the file contexts\n")
sys.stderr.flush()
exists=1
for regex in prefix_regex:
#match a trailing (/*)? which is actually a bug in rpc_pipefs
regex = re.sub(r"\(/\*\)\?$", "", regex)
#match a trailing .+
regex = re.sub(r"\.+$", "", regex)
#match a trailing .*
regex = re.sub(r"\.\*$", "", regex)
#strip a (/.*)? which matches anything trailing to a /*$ which matches trailing /'s
regex = re.sub(r"\(\/\.\*\)\?", "", regex)
regex = regex + "/*$"
if re.search(regex, home, 0):
exists = 0
break
if exists == 1:
return 1
else:
return 0
def getHomeDirs(self):
homedirs = []
homedirs = homedirs + getDefaultHomeDir()
starting_uid=getStartingUID()
if self.usepwd==0:
return homedirs
ulist = pwd.getpwall()
for u in ulist:
if u[2] >= starting_uid and \
not u[6] in EXCLUDE_LOGINS and \
u[5] != "/" and \
u[5].count("/") > 1:
homedir = u[5][:u[5].rfind("/")]
if not homedir in homedirs:
if self.checkExists(homedir)==0:
warning("%s is already defined in %s,\n%s will not create a new context." % (homedir, self.getFileContextFile(), sys.argv[0]))
else:
homedirs.append(homedir)
homedirs.sort()
return homedirs
def genoutput(self):
ret= self.heading()
for h in self.getHomeDirs():
ret += self.getHomeDirContext ("user_u" , h+'/[^/]*', "user")
ret += self.getHomeRootContext(h)
ret += self.genHomeDirContext()
return ret
def printout(self):
print(self.genoutput())
def write(self):
try:
fd = open(self.getFileContextDir()+"/file_contexts.homedirs", "w")
fd.write(self.genoutput())
fd.close()
except IOError as error:
sys.stderr.write("%s: %s\n" % ( sys.argv[0], error ))
#
# This script will generate home dir file context
# based off the homedir_template file, entries in the password file, and
#
try:
usepwd=1
directory="/etc/selinux"
setype=None
gopts, cmds = getopt.getopt(sys.argv[1:], 'nd:t:', ['help',
'type=',
'nopasswd',
'dir='])
for o,a in gopts:
if o == '--type' or o == "-t":
setype=a
if o == '--nopasswd' or o == "-n":
usepwd=0
if o == '--dir' or o == "-d":
directory=a
if o == '--help':
usage()
if setype is None:
setype=getSELinuxType(directory)
if len(cmds) == 2:
oldgenhomedircon(cmds[0], cmds[1])
sys.exit(0)
if len(cmds) != 0:
usage()
selconf=selinuxConfig(directory, setype, usepwd)
selconf.write()
except getopt.error as error:
errorExit("Options Error " + error)
except ValueError as error:
errorExit("ValueError " + error)
except IndexError:
errorExit("IndexError")