From 8d387ee1ecbcde6d7435a909476e50afc9bed464 Mon Sep 17 00:00:00 2001
From: Mark Salyzyn <salyzyn@google.com>
Date: Tue, 5 Apr 2016 09:24:59 -0700
Subject: [PATCH] fix oem_XXXX ids to incorporate both ranges

The XXXX now lines up to the underlying uid and has no offset.
Work with AID_OEM_RESERVED uids.

Test uses hard coded values to catch changes in the API expectations
that may occur in private/android_filesystem_config.h.

SideEffects: names change, some product dependencies.

Bug: 27999086
Change-Id: Ic2b4c36de74ae009a44e14711c75834293828207
---
 libc/bionic/grp_pwd.cpp | 25 ++++++++++++++++---------
 tests/grp_pwd_test.cpp  | 32 ++++++++++++++++++++++++--------
 2 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/libc/bionic/grp_pwd.cpp b/libc/bionic/grp_pwd.cpp
index 1cabab47f..d75b94dac 100644
--- a/libc/bionic/grp_pwd.cpp
+++ b/libc/bionic/grp_pwd.cpp
@@ -312,27 +312,34 @@ static void print_app_name_from_gid(const gid_t gid, char* buffer, const int buf
   }
 }
 
+// oem_XXXX -> uid
+//  Supported ranges:
+//   AID_OEM_RESERVED_START to AID_OEM_RESERVED_END (2900-2999)
+//   AID_OEM_RESERVED_2_START to AID_OEM_RESERVED_2_END (5000-5999)
+// Check OEM id is within range.
+static bool is_oem_id(id_t id) {
+  return (((id >= AID_OEM_RESERVED_START) && (id <= AID_OEM_RESERVED_END)) ||
+      ((id >= AID_OEM_RESERVED_2_START) && (id <= AID_OEM_RESERVED_2_END)));
+}
+
 // Translate an OEM name to the corresponding user/group id.
-// oem_XXX -> AID_OEM_RESERVED_2_START + XXX, iff XXX is within range.
 static id_t oem_id_from_name(const char* name) {
   unsigned int id;
   if (sscanf(name, "oem_%u", &id) != 1) {
     return 0;
   }
-  // Check OEM id is within range.
-  if (id > (AID_OEM_RESERVED_2_END - AID_OEM_RESERVED_2_START)) {
+  if (!is_oem_id(id)) {
     return 0;
   }
-  return AID_OEM_RESERVED_2_START + static_cast<id_t>(id);
+  return static_cast<id_t>(id);
 }
 
 static passwd* oem_id_to_passwd(uid_t uid, passwd_state_t* state) {
-  if (uid < AID_OEM_RESERVED_2_START || uid > AID_OEM_RESERVED_2_END) {
+  if (!is_oem_id(uid)) {
     return NULL;
   }
 
-  snprintf(state->name_buffer_, sizeof(state->name_buffer_), "oem_%u",
-           uid - AID_OEM_RESERVED_2_START);
+  snprintf(state->name_buffer_, sizeof(state->name_buffer_), "oem_%u", uid);
   snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/");
   snprintf(state->sh_buffer_, sizeof(state->sh_buffer_), "/system/bin/sh");
 
@@ -346,12 +353,12 @@ static passwd* oem_id_to_passwd(uid_t uid, passwd_state_t* state) {
 }
 
 static group* oem_id_to_group(gid_t gid, group_state_t* state) {
-  if (gid < AID_OEM_RESERVED_2_START || gid > AID_OEM_RESERVED_2_END) {
+  if (!is_oem_id(gid)) {
     return NULL;
   }
 
   snprintf(state->group_name_buffer_, sizeof(state->group_name_buffer_),
-           "oem_%u", gid - AID_OEM_RESERVED_2_START);
+           "oem_%u", gid);
 
   group* gr = &state->group_;
   gr->gr_name   = state->group_name_buffer_;
diff --git a/tests/grp_pwd_test.cpp b/tests/grp_pwd_test.cpp
index c81ca5803..29cd907d2 100644
--- a/tests/grp_pwd_test.cpp
+++ b/tests/grp_pwd_test.cpp
@@ -122,12 +122,20 @@ TEST(getpwnam, app_id_radio) {
   check_get_passwd("radio", 1001, TYPE_SYSTEM);
 }
 
-TEST(getpwnam, oem_id_0) {
-  check_get_passwd("oem_0", 5000, TYPE_SYSTEM);
+TEST(getpwnam, oem_id_5000) {
+  check_get_passwd("oem_5000", 5000, TYPE_SYSTEM);
 }
 
-TEST(getpwnam, oem_id_999) {
-  check_get_passwd("oem_999", 5999, TYPE_SYSTEM);
+TEST(getpwnam, oem_id_5999) {
+  check_get_passwd("oem_5999", 5999, TYPE_SYSTEM);
+}
+
+TEST(getpwnam, oem_id_2900) {
+  check_get_passwd("oem_2900", 2900, TYPE_SYSTEM);
+}
+
+TEST(getpwnam, oem_id_2999) {
+  check_get_passwd("oem_2999", 2999, TYPE_SYSTEM);
 }
 
 TEST(getpwnam, app_id_nobody) {
@@ -255,12 +263,20 @@ TEST(getgrnam, app_id_radio) {
   check_get_group("radio", 1001);
 }
 
-TEST(getgrnam, oem_id_0) {
-  check_get_group("oem_0", 5000);
+TEST(getgrnam, oem_id_5000) {
+  check_get_group("oem_5000", 5000);
 }
 
-TEST(getgrnam, oem_id_999) {
-  check_get_group("oem_999", 5999);
+TEST(getgrnam, oem_id_5999) {
+  check_get_group("oem_5999", 5999);
+}
+
+TEST(getgrnam, oem_id_2900) {
+  check_get_group("oem_2900", 2900);
+}
+
+TEST(getgrnam, oem_id_2999) {
+  check_get_group("oem_2999", 2999);
 }
 
 TEST(getgrnam, app_id_nobody) {