commit bddd3ef5c1ab6e21e0e3e49fb2b410c9dabe5edc
author Colin Cross <ccross@android.com> Thu Sep 06 11:53:17 2018 -0700
committer Colin Cross <ccross@android.com> Thu Sep 06 15:55:28 2018 -0700
tree 9f285c76b408fde93771f4fa198e7486df5a1327
parent 9666cb415d7d44a86cfb0b7ec1df6e6317fe3259

Use getpwnam and getgrnam in libwifi_hal

libwifi_hal is a vendor module, but it was accidentally getting
the core version of the libcutils headers which included
private/android_filesystem_config.h.  Change it to using
getpwnam("wifi") and getgrnam("wifi") instead of AID_WIFI.

Test: m checkbuild
Bug: 63135587
Bug: 114238698
Change-Id: I28f20fd9f4868c0d1e25fda64f477f6d551cc1dd

libwifi_hal/driver_tool.cpp

diff --git a/libwifi_hal/driver_tool.cpp b/libwifi_hal/driver_tool.cpp
index 3089ee0..0b393d7 100644
--- a/libwifi_hal/driver_tool.cpp
+++ b/libwifi_hal/driver_tool.cpp
@@ -14,10 +14,13 @@
  * limitations under the License.
  */
 
+#include <grp.h>
+#include <pwd.h>
+#include <sys/types.h>
+
 #include "wifi_hal/driver_tool.h"
 
 #include <android-base/logging.h>
-#include <private/android_filesystem_config.h>
 
 #include "hardware_legacy/wifi.h"
 
@@ -35,7 +38,29 @@
     return true;  // HAL doesn't think we need to load firmware for any mode.
   }
 
-  if (chown(WIFI_DRIVER_FW_PATH_PARAM, AID_WIFI, AID_WIFI) != 0) {
+  errno = 0;
+  struct passwd *pwd = getpwnam("wifi");
+  if (pwd == nullptr) {
+    if (errno == 0) {
+      PLOG(ERROR) << "No user 'wifi' found";
+    } else {
+      PLOG(ERROR) << "Error getting uid for wifi: " << strerror(errno);
+    }
+    return false;
+  }
+
+  errno = 0;
+  struct group *grp = getgrnam("wifi");
+  if (grp == nullptr) {
+    if (errno == 0) {
+      PLOG(ERROR) << "No group 'wifi' found";
+    } else {
+      PLOG(ERROR) << "Error getting gid for wifi: " << strerror(errno);
+    }
+    return false;
+  }
+
+  if (chown(WIFI_DRIVER_FW_PATH_PARAM, pwd->pw_uid, grp->gr_gid) != 0) {
     PLOG(ERROR) << "Error changing ownership of '" << WIFI_DRIVER_FW_PATH_PARAM
                 << "' to wifi:wifi";
     return false;