deluser: 2nd attempt at deluser/delgroup size reduction and improvements

Signed-off-by: Tito Ragusa <farmatito@tiscali.it>
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

1 files changed, 70 insertions, 29 deletions

diff --git a/loginutils/deluser.c b/loginutils/deluser.c
index 08ca266..5a159b2 100644
--- a/loginutils/deluser.c
+++ b/loginutils/deluser.c
@@ -14,41 +14,82 @@
 int deluser_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int deluser_main(int argc, char **argv)
 {
-	if (argc != 2
-	 && (!ENABLE_FEATURE_DEL_USER_FROM_GROUP
-	    || applet_name[3] != 'g'
-	    || argc != 3)
-	) {
-		bb_show_usage();
-	}
+	/* User or group name */
+	char *name;
+	/* Username (non-NULL only in "delgroup USER GROUP" case) */
+	char *member;
+	/* Name of passwd or group file */
+	const char *pfile;
+	/* Name of shadow or gshadow file */
+	const char *sfile;
+	/* Are we deluser or delgroup? */
+	bool do_deluser = (ENABLE_DELUSER && (!ENABLE_DELGROUP || applet_name[3] == 'u'));
 
-	if (geteuid())
+	if (geteuid() != 0)
 		bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
 
-	if (ENABLE_DELUSER && applet_name[3] == 'u') {
-		/* deluser USER */
-		if (update_passwd(bb_path_passwd_file, argv[1], NULL, NULL) < 0)
-			return EXIT_FAILURE;
-		if (ENABLE_FEATURE_SHADOWPASSWDS)
-			if (update_passwd(bb_path_shadow_file, argv[1], NULL, NULL) < 0)
-				return EXIT_FAILURE;
-	} else if (ENABLE_DELGROUP) {
-		/* delgroup ... */
-		if (!ENABLE_FEATURE_DEL_USER_FROM_GROUP || argc != 3) {
-			/* delgroup GROUP */
-			if (update_passwd(bb_path_group_file, argv[1], NULL, NULL) < 0)
-				return EXIT_FAILURE;
+	name = argv[1];
+	member = NULL;
+
+	switch (argc) {
+	case 3:
+		if (!ENABLE_FEATURE_DEL_USER_FROM_GROUP || do_deluser)
+			break;
+		/* It's "delgroup USER GROUP" */
+		member = name;
+		name = argv[2];
+		/* Fallthrough */
+
+	case 2:
+		if (do_deluser) {
+			/* "deluser USER" */
+			xgetpwnam(name); /* bail out if USER is wrong */
+			pfile = bb_path_passwd_file;
 			if (ENABLE_FEATURE_SHADOWPASSWDS)
-				if (update_passwd(bb_path_gshadow_file, argv[1], NULL, NULL) < 0)
-					return EXIT_FAILURE;
+				sfile = bb_path_shadow_file;
 		} else {
-			/* delgroup USER GROUP */
-			if (update_passwd(bb_path_group_file, argv[2], NULL, argv[1]) < 0)
-				return EXIT_FAILURE;
+ do_delgroup:
+			/* "delgroup GROUP" or "delgroup USER GROUP" */
+			xgetgrnam(name); /* bail out if GROUP is wrong */
+			if (!member) {
+				/* "delgroup GROUP".
+				 * If user with tha same name exists,
+				 * bail out.
+				 */
+//BUG: check should be done by GID, not by matching name!
+//1. find GROUP's GID
+//2. check that /etc/passwd doesn't have lines of the form
+//   user:pwd:uid:GID:...
+//3. bail out if at least one such line exists
+				if (getpwnam(name) != NULL)
+					bb_error_msg_and_die("'%s' still has '%s' as their primary group!", name, name);
+			}
+			pfile = bb_path_group_file;
 			if (ENABLE_FEATURE_SHADOWPASSWDS)
-				if (update_passwd(bb_path_gshadow_file, argv[2], NULL, argv[1]) < 0)
-					return EXIT_FAILURE;
+				sfile = bb_path_gshadow_file;
+		}
+
+		/* Modify pfile, then sfile */
+		do {
+			if (update_passwd(pfile, name, NULL, member) == -1)
+				return EXIT_FAILURE;
+			if (ENABLE_FEATURE_SHADOWPASSWDS) {
+				pfile = sfile;
+				sfile = NULL;
+			}
+		} while (ENABLE_FEATURE_SHADOWPASSWDS && pfile);
+
+		if (ENABLE_DELGROUP && do_deluser) {
+			/* "deluser USER" also should try to delete
+			 * same-named group. IOW: do "delgroup USER"
+			 */
+//TODO: check how it actually works in upstream.
+//I suspect it is only done if group has no more members.
+			do_deluser = 0;
+			goto do_delgroup;
 		}
+		return EXIT_SUCCESS;
 	}
-	return EXIT_SUCCESS;
+	/* Reached only if number of command line args is wrong */
+	bb_show_usage();
 }