From 815f1670961bee0f8104f87feae89835249d51a6 Mon Sep 17 00:00:00 2001
From: Nathan Holstein <nathan.holstein@gmail.com>
Date: Sun, 2 Aug 2015 15:52:15 -0400
Subject: [PATCH] Implement the semantics of setusercontext().

---
 libopenbsd/setusercontext.c | 37 ++++++++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/libopenbsd/setusercontext.c b/libopenbsd/setusercontext.c
index 692b51a..7a477b6 100644
--- a/libopenbsd/setusercontext.c
+++ b/libopenbsd/setusercontext.c
@@ -1,15 +1,21 @@
 /* Copyright 2015 Nathan Holstein */
 
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <errno.h>
-#include <stdio.h>
+#include <pwd.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #include "openbsd.h"
 
 int
-setusercontext(login_cap_t *lc, struct passwd *pwd, uid_t uid, unsigned int flags)
+setusercontext(login_cap_t *lc, struct passwd *pw, uid_t uid, unsigned int flags)
 {
-	if (lc != NULL || pwd == NULL ||
+	int ret;
+
+	if (lc != NULL || pw == NULL ||
 			(flags & ~(LOGIN_SETGROUP | LOGIN_SETPRIORITY |
 			           LOGIN_SETRESOURCES | LOGIN_SETUMASK |
 			           LOGIN_SETUSER)) != 0) {
@@ -17,8 +23,29 @@ setusercontext(login_cap_t *lc, struct passwd *pwd, uid_t uid, unsigned int flag
 		return -1;
 	}
 
-	fprintf(stderr, "failing setusercontext() for %d\n", (int) uid);
+	if (flags & LOGIN_SETGROUP) {
+		if ((ret = setgid(pw->pw_gid)) != 0)
+			return ret;
+		if ((ret = initgroups(pw->pw_name, pw->pw_gid)) != 0)
+			return ret;
+	}
+
+	if (flags & LOGIN_SETPRIORITY) {
+		if ((ret = setpriority(PRIO_PROCESS, getpid(), 0)) != 0)
+			return ret;
+		if ((ret = setpriority(PRIO_USER, uid, 0)) != 0)
+			return ret;
+	}
+
+	if (flags & LOGIN_SETRESOURCES) {
+	}
+
+	if (flags & LOGIN_SETUMASK)
+		umask(S_IWGRP | S_IWOTH);
+
+	if (flags & LOGIN_SETUSER)
+		return setuid(uid);
 
-	return -1;
+	return 0;
 }
 
-- 
2.39.2