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 08ca266d0..5a159b205 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();
 }