1 files changed, 82 insertions, 0 deletions
diff --git a/mysys/my_setuser.c b/mysys/my_setuser.c
new file mode 100644
index 00000000..e35d6602
--- /dev/null
+++ b/mysys/my_setuser.c
@@ -0,0 +1,82 @@
+#include <my_global.h>
+#include <m_string.h>
+#include <my_sys.h>
+#include <my_pthread.h>
+#ifdef HAVE_PWD_H
+#include <pwd.h>
+#endif
+#ifdef HAVE_GRP_H
+#include <grp.h>
+#endif
+
+struct passwd *my_check_user(const char *user, myf MyFlags)
+{
+  struct passwd *user_info;
+  uid_t user_id= geteuid();
+  DBUG_ENTER("my_check_user");
+
+  // Don't bother if we aren't superuser
+  if (user_id)
+  {
+    if (user)
+    {
+      /* Don't give a warning, if real user is same as given with --user */
+      user_info= getpwnam(user);
+      if (!user_info || user_id != user_info->pw_uid)
+      {
+        my_errno= EPERM;
+        if (MyFlags & MY_WME)
+          my_printf_error(my_errno, "One can only use the --user switch if "
+                         "running as root", MYF(ME_WARNING|ME_ERROR_LOG));
+      }
+    }
+    DBUG_RETURN(NULL);
+  }
+  if (!user)
+  {
+    if (MyFlags & MY_FAE)
+    {
+      my_errno= EINVAL;
+      my_printf_error(my_errno, "Please consult the Knowledge Base to find "
+                      "out how to run mysqld as root!", MYF(ME_ERROR_LOG));
+    }
+    DBUG_RETURN(NULL);
+  }
+  if (!strcmp(user,"root"))
+    DBUG_RETURN(NULL);
+
+  if (!(user_info= getpwnam(user)))
+  {
+    // Allow a numeric uid to be used
+    int err= 0;
+    user_id= my_strtoll10(user, NULL, &err);
+    if (err || !(user_info= getpwuid(user_id)))
+    {
+      my_errno= EINVAL;
+      my_printf_error(my_errno, "Can't change to run as user '%s'.  Please "
+                      "check that the user exists!", MYF(ME_ERROR_LOG), user);
+      DBUG_RETURN(NULL);
+    }
+  }
+  DBUG_ASSERT(user_info);
+  DBUG_RETURN(user_info);
+}
+
+int my_set_user(const char *user, struct passwd *user_info, myf MyFlags)
+{
+  DBUG_ENTER("my_set_user");
+
+  DBUG_ASSERT(user_info != 0);
+#ifdef HAVE_INITGROUPS
+  initgroups(user, user_info->pw_gid);
+#endif
+  if (setgid(user_info->pw_gid) == -1 || setuid(user_info->pw_uid) == -1)
+  {
+    my_errno= errno;
+    if (MyFlags & MY_WME)
+      my_printf_error(errno, "Cannot change uid/gid (errno: %d)", MYF(ME_ERROR_LOG),
+                      errno);
+    DBUG_RETURN(my_errno);
+  }
+  DBUG_RETURN(0);
+}