From 011694ae838bf1ee9002c81f7db72f9b4ff8de6b Mon Sep 17 00:00:00 2001
From: Ikey Doherty <ikey@solus-project.com>
Date: Sun, 3 Dec 2017 10:35:22 +0000
Subject: [PATCH] migrations: Add 03_users_group_gid

This migration will fix the dynamically assigned gid of `users` group
from the 900 range to the static 100.

Signed-off-by: Ikey Doherty <ikey@solus-project.com>
---
 src/cli/migrate.c                   |  1 +
 src/meson.build                     |  1 +
 src/migrations/03_users_group_gid.c | 42 +++++++++++++++++++++++++++++
 src/migrations/declared.h           | 12 +++++++++
 src/migrations/shared.c             | 25 +++++++++++++++++
 5 files changed, 81 insertions(+)
 create mode 100644 src/migrations/03_users_group_gid.c

diff --git a/src/cli/migrate.c b/src/cli/migrate.c
index 121a318..6bb02d9 100644
--- a/src/cli/migrate.c
+++ b/src/cli/migrate.c
@@ -37,6 +37,7 @@
 static QolMigration migration_table[] = {
         MIGRATION("Add users to scanner group", 01_scanner_group),
         MIGRATION("Add users to plugdev group", 02_plugdev_group),
+        MIGRATION("Set static gid for 'users' group", 03_users_group_gid),
 };
 
 /**
diff --git a/src/meson.build b/src/meson.build
index 39036ca..64c2ddb 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -20,6 +20,7 @@ endif
 migrations = [
     '01_scanner_group',
     '02_plugdev_group',
+    '03_users_group_gid',
 ]
 
 # Insert into sources
diff --git a/src/migrations/03_users_group_gid.c b/src/migrations/03_users_group_gid.c
new file mode 100644
index 0000000..702f297
--- /dev/null
+++ b/src/migrations/03_users_group_gid.c
@@ -0,0 +1,42 @@
+/*
+ * This file is part of qol-assist.
+ *
+ * Copyright © 2017 Solus Project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+
+#include "declared.h"
+
+/**
+ * Fix the users group GID.
+ *
+ * Solus never used this group before, however by the time we needed it for
+ * SAMBA, a systemd update had created a 'users' group with a bogus GID in
+ * the 900 range, so we forcibly set it back to 100 here before using it
+ * for anything.
+ */
+bool qol_migration_03_users_group_gid(QolContext *context)
+{
+        return qol_migration_update_group_id(context, "users", 100);
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=8 tabstop=8 expandtab:
+ * :indentSize=8:tabSize=8:noTabs=true:
+ */
diff --git a/src/migrations/declared.h b/src/migrations/declared.h
index 2a3bbf5..6f80b27 100644
--- a/src/migrations/declared.h
+++ b/src/migrations/declared.h
@@ -23,10 +23,22 @@
  */
 bool qol_migration_push_active_admin_group(QolContext *context, const char *group);
 
+/**
+ * Update the group id for the given group name if it does not currently
+ * match the given ID
+ *
+ * @param context Pointer to a valid QolContext
+ * @param group Name for the group in question
+ *
+ * @returns True if the operation succeeded
+ */
+bool qol_migration_update_group_id(QolContext *context, const char *group, int gid);
+
 /* Migrations follow */
 
 bool qol_migration_01_scanner_group(QolContext *context);
 bool qol_migration_02_plugdev_group(QolContext *context);
+bool qol_migration_03_users_group_gid(QolContext *context);
 
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
diff --git a/src/migrations/shared.c b/src/migrations/shared.c
index 9b6e1b3..ec908fe 100644
--- a/src/migrations/shared.c
+++ b/src/migrations/shared.c
@@ -11,7 +11,9 @@
 
 #define _GNU_SOURCE
 
+#include <errno.h>
 #include <stdio.h>
+#include <string.h>
 
 #include "declared.h"
 
@@ -39,6 +41,29 @@ bool qol_migration_push_active_admin_group(QolContext *context, const char *grou
         return true;
 }
 
+bool qol_migration_update_group_id(QolContext *context, const char *group, int gid)
+{
+        int current_id = 1;
+
+        current_id = qol_user_manager_get_group_id(context->user_manager, group);
+        if (current_id < 0) {
+                fprintf(stderr, "Failed to find '%s' group: %s\n", group, strerror(errno));
+                return false;
+        }
+
+        /* No need to perform an update here, it's been done */
+        if (current_id == gid) {
+                return true;
+        }
+
+        fprintf(stderr, "Changing group '%s' ID from %d to %d\n", group, current_id, gid);
+        if (!qol_user_manager_change_group_id(context->user_manager, group, gid)) {
+                fprintf(stderr, "Failed to change group id: %s\n", strerror(errno));
+                return false;
+        }
+        return true;
+}
+
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *