privs: move drop_privileges out of xutils

Again, also to be able to maintain this more easily.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/privs.c b/privs.c
new file mode 100644
index 0000000..ac4ad25
--- /dev/null
+++ b/privs.c
@@ -0,0 +1,19 @@
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "privs.h"
+#include "die.h"
+
+void drop_privileges(bool enforce, uid_t uid, gid_t gid)
+{
+	if (enforce) {
+		if (uid == getuid())
+			panic("Uid cannot be the same as the current user!\n");
+		if (gid == getgid())
+			panic("Gid cannot be the same as the current user!\n");
+	}
+	if (setgid(gid) != 0)
+		panic("Unable to drop group privileges: %s!\n", strerror(errno));
+	if (setuid(uid) != 0)
+		panic("Unable to drop user privileges: %s!\n", strerror(errno));
+}