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Diffstat (limited to 'support/genhomedircon.py')
| -rw-r--r-- | support/genhomedircon.py | 481 |
1 files changed, 481 insertions, 0 deletions
diff --git a/support/genhomedircon.py b/support/genhomedircon.py new file mode 100644 index 000000000..e14f9fbf3 --- /dev/null +++ b/support/genhomedircon.py @@ -0,0 +1,481 @@ +#!/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 subprocess, sys, os, pwd, getopt, re + +EXCLUDE_LOGINS=["/sbin/nologin", "/bin/false"] + +def getStartingUID(): + starting_uid = 99999 + rc=subprocess.getstatusoutput("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=subprocess.getstatusoutput("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 = subprocess.getstatusoutput("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=subprocess.getstatusoutput("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=subprocess.getstatusoutput("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=subprocess.getstatusoutput("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=subprocess.getstatusoutput("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("\(/\*\)\?$", "", regex) + #match a trailing .+ + regex = re.sub("\.+$", "", regex) + #match a trailing .* + regex = re.sub("\.\*$", "", regex) + #strip a (/.*)? which matches anything trailing to a /*$ which matches trailing /'s + regex = re.sub("\(\/\.\*\)\?", "", 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=subprocess.getstatusoutput("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=subprocess.getstatusoutput("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=subprocess.getstatusoutput("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=subprocess.getstatusoutput("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=subprocess.getstatusoutput("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 = subprocess.getstatusoutput('grep "^user" %s' % self.getSystemUsersFile()) + if rc[0] == 0: + users+=rc[1]+"\n" + rc = subprocess.getstatusoutput("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=subprocess.getstatusoutput("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 subprocess.getstatusoutput("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=subprocess.getstatusoutput("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("\(/\*\)\?$", "", regex) + #match a trailing .+ + regex = re.sub("\.+$", "", regex) + #match a trailing .* + regex = re.sub("\.\*$", "", regex) + #strip a (/.*)? which matches anything trailing to a /*$ which matches trailing /'s + regex = re.sub("\(\/\.\*\)\?", "", 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") |