init: split security functions out of init.cpp

This change splits out the selinux initialization and supporting
functionality into selinux.cpp and splits the security related
initialization of the rng, etc to security.cpp.  It also provides
additional documentation for SEPolicy loading as this has been
requested by some teams.

It additionally cleans up sehandle and sehandle_prop.  The former is
static within selinux.cpp and new wrapper functions are created around
selabel_lookup*() to better serve the users.  The latter is moved to
property_service.cpp as it is isolated to that file for its usage.

Test: boot bullhead
Merged-In: Idc95d493cebc681fbe686b5160502f36af149f60
Change-Id: Idc95d493cebc681fbe686b5160502f36af149f60
(cherry picked from commit 9afb86b25d8675927cb37c86119a7ecf19f74819)

1 files changed, 12 insertions, 25 deletions

diff --git a/init/builtins.cpp b/init/builtins.cpp
index 5335608bc..fa93dfd34 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -224,23 +224,22 @@ static int do_insmod(const std::vector<std::string>& args) {
     return insmod(filename.c_str(), options.c_str(), flags);
 }
 
+// mkdir <path> [mode] [owner] [group]
 static int do_mkdir(const std::vector<std::string>& args) {
     mode_t mode = 0755;
-    int ret;
-
-    /* mkdir <path> [mode] [owner] [group] */
-
     if (args.size() >= 3) {
         mode = std::strtoul(args[2].c_str(), 0, 8);
     }
 
-    ret = make_dir(args[1].c_str(), mode, sehandle);
-    /* chmod in case the directory already exists */
-    if (ret == -1 && errno == EEXIST) {
-        ret = fchmodat(AT_FDCWD, args[1].c_str(), mode, AT_SYMLINK_NOFOLLOW);
-    }
-    if (ret == -1) {
-        return -errno;
+    if (!make_dir(args[1], mode)) {
+        /* chmod in case the directory already exists */
+        if (errno == EEXIST) {
+            if (fchmodat(AT_FDCWD, args[1].c_str(), mode, AT_SYMLINK_NOFOLLOW) == -1) {
+                return -errno;
+            }
+        } else {
+            return -errno;
+        }
     }
 
     if (args.size() >= 4) {
@@ -265,8 +264,7 @@ static int do_mkdir(const std::vector<std::string>& args) {
 
         /* chown may have cleared S_ISUID and S_ISGID, chmod again */
         if (mode & (S_ISUID | S_ISGID)) {
-            ret = fchmodat(AT_FDCWD, args[1].c_str(), mode, AT_SYMLINK_NOFOLLOW);
-            if (ret == -1) {
+            if (fchmodat(AT_FDCWD, args[1].c_str(), mode, AT_SYMLINK_NOFOLLOW) == -1) {
                 return -errno;
             }
         }
@@ -834,17 +832,6 @@ static int do_wait_for_prop(const std::vector<std::string>& args) {
     return 0;
 }
 
-/*
- * Callback to make a directory from the ext4 code
- */
-static int do_installkeys_ensure_dir_exists(const char* dir) {
-    if (make_dir(dir, 0700, sehandle) && errno != EEXIST) {
-        return -1;
-    }
-
-    return 0;
-}
-
 static bool is_file_crypto() {
     return android::base::GetProperty("ro.crypto.type", "") == "file";
 }
@@ -854,7 +841,7 @@ static int do_installkey(const std::vector<std::string>& args) {
         return 0;
     }
     auto unencrypted_dir = args[1] + e4crypt_unencrypted_folder;
-    if (do_installkeys_ensure_dir_exists(unencrypted_dir.c_str())) {
+    if (!make_dir(unencrypted_dir, 0700) && errno != EEXIST) {
         PLOG(ERROR) << "Failed to create " << unencrypted_dir;
         return -1;
     }