NetworkManager/src/core/nm-checkpoint-manager.c

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2016 Red Hat, Inc.
 */

#include "src/core/nm-default-daemon.h"

#include "nm-checkpoint-manager.h"

#include "nm-checkpoint.h"
#include "nm-connection.h"
#include "nm-core-utils.h"
#include "devices/nm-device.h"
#include "nm-manager.h"
#include "nm-utils.h"
#include "c-list/src/c-list.h"

/*****************************************************************************/

struct _NMCheckpointManager {
    NMManager  *_manager;
    GParamSpec *property_spec;
    CList       checkpoints_lst_head;
};

#define GET_MANAGER(self)                               \
    ({                                                  \
        typeof(self) _self = (self);                    \
                                                        \
        _nm_unused NMCheckpointManager *_self2 = _self; \
                                                        \
        nm_assert(_self);                               \
        nm_assert(NM_IS_MANAGER(_self->_manager));      \
        _self->_manager;                                \
    })

/*****************************************************************************/

#define _NMLOG_DOMAIN      LOGD_CORE
#define _NMLOG(level, ...) __NMLOG_DEFAULT(level, _NMLOG_DOMAIN, "checkpoint", __VA_ARGS__)

/*****************************************************************************/

static void
notify_checkpoints(NMCheckpointManager *self)
{
    g_object_notify_by_pspec((GObject *) GET_MANAGER(self), self->property_spec);
}

static void
destroy_checkpoint(NMCheckpointManager *self, NMCheckpoint *checkpoint, gboolean log_destroy)
{
    nm_assert(NM_IS_CHECKPOINT(checkpoint));
    nm_assert(nm_dbus_object_is_exported(NM_DBUS_OBJECT(checkpoint)));
    nm_assert(c_list_contains(&self->checkpoints_lst_head, &checkpoint->checkpoints_lst));

    nm_checkpoint_set_timeout_callback(checkpoint, NULL, NULL);

    c_list_unlink(&checkpoint->checkpoints_lst);

    if (log_destroy)
        nm_checkpoint_log_destroy(checkpoint);

    notify_checkpoints(self);

    nm_dbus_object_unexport(NM_DBUS_OBJECT(checkpoint));
    g_object_unref(checkpoint);
}

static GVariant *
rollback_checkpoint(NMCheckpointManager *self, NMCheckpoint *checkpoint)
{
    GVariant    *result;
    const CList *iter;

    nm_assert(c_list_contains(&self->checkpoints_lst_head, &checkpoint->checkpoints_lst));

    /* we destroy first all overlapping checkpoints that are younger/newer. */
    for (iter = checkpoint->checkpoints_lst.next; iter != &self->checkpoints_lst_head;) {
        NMCheckpoint *cp = c_list_entry(iter, NMCheckpoint, checkpoints_lst);

        iter = iter->next;
        if (nm_checkpoint_includes_devices_of(cp, checkpoint)) {
            /* the younger checkpoint has overlapping devices and gets obsoleted.
             * Destroy it. */
            destroy_checkpoint(self, cp, TRUE);
        }
    }

    result = nm_checkpoint_rollback(checkpoint);
    destroy_checkpoint(self, checkpoint, FALSE);
    return result;
}

static void
rollback_timeout_cb(NMCheckpoint *checkpoint, gpointer user_data)
{
    NMCheckpointManager       *self   = user_data;
    gs_unref_variant GVariant *result = NULL;

    result = rollback_checkpoint(self, checkpoint);
}

NMCheckpoint *
nm_checkpoint_manager_create(NMCheckpointManager    *self,
                             const char *const      *device_paths,
                             guint32                 rollback_timeout,
                             NMCheckpointCreateFlags flags,
                             GError                **error)
{
    NMManager                   *manager;
    NMCheckpoint                *checkpoint;
    gs_unref_ptrarray GPtrArray *devices = NULL;
    NMDevice                    *device;

    g_return_val_if_fail(self, FALSE);
    g_return_val_if_fail(!error || !*error, FALSE);
    manager = GET_MANAGER(self);

    devices = g_ptr_array_new();

    if (!device_paths || !device_paths[0]) {
        const CList *tmp_lst;

        nm_manager_for_each_device (manager, device, tmp_lst) {
            /* FIXME: there is no strong reason to skip over unrealized devices.
             *        Also, NMCheckpoint anticipates to handle them (in parts). */
            if (!nm_device_is_real(device))
                continue;
            nm_assert(nm_dbus_object_get_path(NM_DBUS_OBJECT(device)));
            g_ptr_array_add(devices, device);
        }
    } else if (NM_FLAGS_HAS(flags, NM_CHECKPOINT_CREATE_FLAG_DISCONNECT_NEW_DEVICES)) {
        g_set_error_literal(
            error,
            NM_MANAGER_ERROR,
            NM_MANAGER_ERROR_INVALID_ARGUMENTS,
            "the DISCONNECT_NEW_DEVICES flag can only be used with an empty device list");
        return NULL;
    } else {
        for (; *device_paths; device_paths++) {
            device = nm_manager_get_device_by_path(manager, *device_paths);
            if (!device) {
                g_set_error(error,
                            NM_MANAGER_ERROR,
                            NM_MANAGER_ERROR_UNKNOWN_DEVICE,
                            "device %s does not exist",
                            *device_paths);
                return NULL;
            }
            if (!nm_device_is_real(device)) {
                g_set_error(error,
                            NM_MANAGER_ERROR,
                            NM_MANAGER_ERROR_UNKNOWN_DEVICE,
                            "device %s is not realized",
                            *device_paths);
                return NULL;
            }
            g_ptr_array_add(devices, device);
        }
    }

    if (!devices->len) {
        g_set_error_literal(error,
                            NM_MANAGER_ERROR,
                            NM_MANAGER_ERROR_INVALID_ARGUMENTS,
                            "no device available");
        return NULL;
    }

    if (NM_FLAGS_HAS(flags, NM_CHECKPOINT_CREATE_FLAG_DESTROY_ALL))
        nm_checkpoint_manager_destroy_all(self);
    else if (!NM_FLAGS_HAS(flags, NM_CHECKPOINT_CREATE_FLAG_ALLOW_OVERLAPPING)) {
        c_list_for_each_entry (checkpoint, &self->checkpoints_lst_head, checkpoints_lst) {
            device = nm_checkpoint_includes_devices(checkpoint,
                                                    (NMDevice *const *) devices->pdata,
                                                    devices->len);
            if (device) {
                g_set_error(error,
                            NM_MANAGER_ERROR,
                            NM_MANAGER_ERROR_INVALID_ARGUMENTS,
                            "device '%s' is already included in checkpoint %s",
                            nm_device_get_iface(device),
                            nm_dbus_object_get_path(NM_DBUS_OBJECT(checkpoint)));
                return NULL;
            }
        }
    }

    checkpoint = nm_checkpoint_new(manager, devices, rollback_timeout, flags);

    nm_dbus_object_export(NM_DBUS_OBJECT(checkpoint));

    nm_checkpoint_set_timeout_callback(checkpoint, rollback_timeout_cb, self);
    c_list_link_tail(&self->checkpoints_lst_head, &checkpoint->checkpoints_lst);
    notify_checkpoints(self);
    return checkpoint;
}

void
nm_checkpoint_manager_destroy_all(NMCheckpointManager *self)
{
    NMCheckpoint *checkpoint;

    g_return_if_fail(self);

    while ((checkpoint =
                c_list_first_entry(&self->checkpoints_lst_head, NMCheckpoint, checkpoints_lst)))
        destroy_checkpoint(self, checkpoint, TRUE);
}

gboolean
nm_checkpoint_manager_destroy(NMCheckpointManager *self, const char *path, GError **error)
{
    NMCheckpoint *checkpoint;

    g_return_val_if_fail(self, FALSE);
    g_return_val_if_fail(path && path[0] == '/', FALSE);
    g_return_val_if_fail(!error || !*error, FALSE);

    if (!nm_dbus_path_not_empty(path)) {
        nm_checkpoint_manager_destroy_all(self);
        return TRUE;
    }

    checkpoint = nm_checkpoint_manager_lookup_by_path(self, path, error);
    if (!checkpoint)
        return FALSE;

    destroy_checkpoint(self, checkpoint, TRUE);
    return TRUE;
}

gboolean
nm_checkpoint_manager_rollback(NMCheckpointManager *self,
                               const char          *path,
                               GVariant           **results,
                               GError             **error)
{
    NMCheckpoint *checkpoint;

    g_return_val_if_fail(self, FALSE);
    g_return_val_if_fail(path && path[0] == '/', FALSE);
    g_return_val_if_fail(results, FALSE);
    g_return_val_if_fail(!error || !*error, FALSE);

    checkpoint = nm_checkpoint_manager_lookup_by_path(self, path, error);
    if (!checkpoint)
        return FALSE;

    *results = rollback_checkpoint(self, checkpoint);
    return TRUE;
}

NMCheckpoint *
nm_checkpoint_manager_lookup_by_path(NMCheckpointManager *self, const char *path, GError **error)
{
    NMCheckpoint *checkpoint;

    g_return_val_if_fail(self, NULL);

    checkpoint = nm_dbus_manager_lookup_object_with_type(
        nm_dbus_object_get_manager(NM_DBUS_OBJECT(GET_MANAGER(self))),
        NM_TYPE_CHECKPOINT,
        path);
    if (!checkpoint) {
        g_set_error(error,
                    NM_MANAGER_ERROR,
                    NM_MANAGER_ERROR_INVALID_ARGUMENTS,
                    "checkpoint %s does not exist",
                    path);
        return NULL;
    }

    nm_assert(c_list_contains(&self->checkpoints_lst_head, &checkpoint->checkpoints_lst));
    return checkpoint;
}

const char **
nm_checkpoint_manager_get_checkpoint_paths(NMCheckpointManager *self, guint *out_length)
{
    NMCheckpoint *checkpoint;
    const char  **strv;
    guint         num, i = 0;

    num = c_list_length(&self->checkpoints_lst_head);
    NM_SET_OUT(out_length, num);
    if (!num)
        return NULL;

    strv = g_new(const char *, num + 1);
    c_list_for_each_entry (checkpoint, &self->checkpoints_lst_head, checkpoints_lst)
        strv[i++] = nm_dbus_object_get_path(NM_DBUS_OBJECT(checkpoint));
    nm_assert(i == num);
    strv[i] = NULL;
    return strv;
}

gboolean
nm_checkpoint_manager_adjust_rollback_timeout(NMCheckpointManager *self,
                                              const char          *path,
                                              guint32              add_timeout,
                                              GError             **error)
{
    NMCheckpoint *checkpoint;

    g_return_val_if_fail(self, FALSE);
    g_return_val_if_fail(path && path[0] == '/', FALSE);
    g_return_val_if_fail(!error || !*error, FALSE);

    checkpoint = nm_checkpoint_manager_lookup_by_path(self, path, error);
    if (!checkpoint)
        return FALSE;

    nm_checkpoint_adjust_rollback_timeout(checkpoint, add_timeout);
    return TRUE;
}

/*****************************************************************************/

NMCheckpointManager *
nm_checkpoint_manager_new(NMManager *manager, GParamSpec *spec)
{
    NMCheckpointManager *self;

    g_return_val_if_fail(NM_IS_MANAGER(manager), FALSE);

    self = g_slice_new0(NMCheckpointManager);

    /* the NMCheckpointManager instance is actually owned by NMManager.
     * Thus, we cannot take a reference to it, and we also don't bother
     * taking a weak-reference. Instead let GET_MANAGER() assert that
     * self->_manager is alive -- which we always expect as the lifetime
     * of NMManager shall surpass the lifetime of the NMCheckpointManager
     * instance. */
    self->_manager      = manager;
    self->property_spec = spec;
    c_list_init(&self->checkpoints_lst_head);
    return self;
}

void
nm_checkpoint_manager_free(NMCheckpointManager *self)
{
    if (!self)
        return;

    nm_checkpoint_manager_destroy_all(self);
    g_slice_free(NMCheckpointManager, self);
}