1 files changed, 48 insertions, 0 deletions
diff --git a/toolbox/uid_from_user.c b/toolbox/uid_from_user.c
new file mode 100644
index 0000000..d70f410
--- /dev/null
+++ b/toolbox/uid_from_user.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2014, The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <limits.h>
+#include <pwd.h>
+#include <stdlib.h>
+#include <sys/types.h>
+
+int uid_from_user(const char* name, uid_t* uid) {
+  struct passwd* pw = getpwnam(name);
+  if (pw != NULL) {
+    *uid = pw->pw_uid;
+    return 0;
+  }
+  // Try to parse as an integer.
+  char* end_ptr;
+  unsigned long number = strtoul(name, &end_ptr, 0);
+  if (end_ptr == name || *end_ptr != '\0' || number > INT_MAX) {
+    return -1;
+  }
+  *uid = (int) number;
+  return 0;
+}