/* Copyright (C) 2010-2017  B.A.T.M.A.N. contributors:
 *
 * Marek Lindner
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "debugfs.h"
#include "main.h"

#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/netdevice.h>
#include <linux/printk.h>
#include <linux/sched.h> /* for linux/wait.h */
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/stddef.h>
#include <linux/stringify.h>
#include <linux/sysfs.h>
#include <net/net_namespace.h>

#include "bat_algo.h"
#include "bridge_loop_avoidance.h"
#include "distributed-arp-table.h"
#include "gateway_client.h"
#include "icmp_socket.h"
#include "log.h"
#include "multicast.h"
#include "network-coding.h"
#include "originator.h"
#include "translation-table.h"

static struct dentry *batadv_debugfs;

static int batadv_algorithms_open(struct inode *inode, struct file *file)
{
        return single_open(file, batadv_algo_seq_print_text, NULL);
}

static int neighbors_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_hardif_neigh_seq_print_text, net_dev);
}

static int batadv_originators_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_orig_seq_print_text, net_dev);
}

/**
 * batadv_originators_hardif_open - handles debugfs output for the
 *  originator table of an hard interface
 * @inode: inode pointer to debugfs file
 * @file: pointer to the seq_file
 *
 * Return: 0 on success or negative error number in case of failure
 */
static int batadv_originators_hardif_open(struct inode *inode,
                                          struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_orig_hardif_seq_print_text, net_dev);
}

static int batadv_gateways_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_gw_client_seq_print_text, net_dev);
}

static int batadv_transtable_global_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_tt_global_seq_print_text, net_dev);
}

#ifdef CONFIG_BATMAN_ADV_BLA
static int batadv_bla_claim_table_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_bla_claim_table_seq_print_text,
                           net_dev);
}

static int batadv_bla_backbone_table_open(struct inode *inode,
                                          struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_bla_backbone_table_seq_print_text,
                           net_dev);
}

#endif

#ifdef CONFIG_BATMAN_ADV_DAT
/**
 * batadv_dat_cache_open - Prepare file handler for reads from dat_chache
 * @inode: inode which was opened
 * @file: file handle to be initialized
 *
 * Return: 0 on success or negative error number in case of failure
 */
static int batadv_dat_cache_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_dat_cache_seq_print_text, net_dev);
}
#endif

static int batadv_transtable_local_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_tt_local_seq_print_text, net_dev);
}

struct batadv_debuginfo {
        struct attribute attr;
        const struct file_operations fops;
};

#ifdef CONFIG_BATMAN_ADV_NC
static int batadv_nc_nodes_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_nc_nodes_seq_print_text, net_dev);
}
#endif

#ifdef CONFIG_BATMAN_ADV_MCAST
/**
 * batadv_mcast_flags_open - prepare file handler for reads from mcast_flags
 * @inode: inode which was opened
 * @file: file handle to be initialized
 *
 * Return: 0 on success or negative error number in case of failure
 */
static int batadv_mcast_flags_open(struct inode *inode, struct file *file)
{
        struct net_device *net_dev = (struct net_device *)inode->i_private;

        return single_open(file, batadv_mcast_flags_seq_print_text, net_dev);
}
#endif

#define BATADV_DEBUGINFO(_name, _mode, _open)           \
struct batadv_debuginfo batadv_debuginfo_##_name = {    \
        .attr = {                                       \
                .name = __stringify(_name),             \
                .mode = _mode,                          \
        },                                              \
        .fops = {                                       \
                .owner = THIS_MODULE,                   \
                .open = _open,                          \
                .read   = seq_read,                     \
                .llseek = seq_lseek,                    \
                .release = single_release,              \
        },                                              \
}

/* the following attributes are general and therefore they will be directly
 * placed in the BATADV_DEBUGFS_SUBDIR subdirectory of debugfs
 */
static BATADV_DEBUGINFO(routing_algos, 0444, batadv_algorithms_open);

static struct batadv_debuginfo *batadv_general_debuginfos[] = {
        &batadv_debuginfo_routing_algos,
        NULL,
};

/* The following attributes are per soft interface */
static BATADV_DEBUGINFO(neighbors, 0444, neighbors_open);
static BATADV_DEBUGINFO(originators, 0444, batadv_originators_open);
static BATADV_DEBUGINFO(gateways, 0444, batadv_gateways_open);
static BATADV_DEBUGINFO(transtable_global, 0444, batadv_transtable_global_open);
#ifdef CONFIG_BATMAN_ADV_BLA
static BATADV_DEBUGINFO(bla_claim_table, 0444, batadv_bla_claim_table_open);
static BATADV_DEBUGINFO(bla_backbone_table, 0444,
                        batadv_bla_backbone_table_open);
#endif
#ifdef CONFIG_BATMAN_ADV_DAT
static BATADV_DEBUGINFO(dat_cache, 0444, batadv_dat_cache_open);
#endif
static BATADV_DEBUGINFO(transtable_local, 0444, batadv_transtable_local_open);
#ifdef CONFIG_BATMAN_ADV_NC
static BATADV_DEBUGINFO(nc_nodes, 0444, batadv_nc_nodes_open);
#endif
#ifdef CONFIG_BATMAN_ADV_MCAST
static BATADV_DEBUGINFO(mcast_flags, 0444, batadv_mcast_flags_open);
#endif

static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
        &batadv_debuginfo_neighbors,
        &batadv_debuginfo_originators,
        &batadv_debuginfo_gateways,
        &batadv_debuginfo_transtable_global,
#ifdef CONFIG_BATMAN_ADV_BLA
        &batadv_debuginfo_bla_claim_table,
        &batadv_debuginfo_bla_backbone_table,
#endif
#ifdef CONFIG_BATMAN_ADV_DAT
        &batadv_debuginfo_dat_cache,
#endif
        &batadv_debuginfo_transtable_local,
#ifdef CONFIG_BATMAN_ADV_NC
        &batadv_debuginfo_nc_nodes,
#endif
#ifdef CONFIG_BATMAN_ADV_MCAST
        &batadv_debuginfo_mcast_flags,
#endif
        NULL,
};

#define BATADV_HARDIF_DEBUGINFO(_name, _mode, _open)            \
struct batadv_debuginfo batadv_hardif_debuginfo_##_name = {     \
        .attr = {                                               \
                .name = __stringify(_name),                     \
                .mode = _mode,                                  \
        },                                                      \
        .fops = {                                               \
                .owner = THIS_MODULE,                           \
                .open = _open,                                  \
                .read   = seq_read,                             \
                .llseek = seq_lseek,                            \
                .release = single_release,                      \
        },                                                      \
}

static BATADV_HARDIF_DEBUGINFO(originators, 0444,
                               batadv_originators_hardif_open);

static struct batadv_debuginfo *batadv_hardif_debuginfos[] = {
        &batadv_hardif_debuginfo_originators,
        NULL,
};

void batadv_debugfs_init(void)
{
        struct batadv_debuginfo **bat_debug;
        struct dentry *file;

        batadv_debugfs = debugfs_create_dir(BATADV_DEBUGFS_SUBDIR, NULL);
        if (batadv_debugfs == ERR_PTR(-ENODEV))
                batadv_debugfs = NULL;

        if (!batadv_debugfs)
                goto err;

        for (bat_debug = batadv_general_debuginfos; *bat_debug; ++bat_debug) {
                file = debugfs_create_file(((*bat_debug)->attr).name,
                                           S_IFREG | ((*bat_debug)->attr).mode,
                                           batadv_debugfs, NULL,
                                           &(*bat_debug)->fops);
                if (!file) {
                        pr_err("Can't add general debugfs file: %s\n",
                               ((*bat_debug)->attr).name);
                        goto err;
                }
        }

        return;
err:
        debugfs_remove_recursive(batadv_debugfs);
        batadv_debugfs = NULL;
}

void batadv_debugfs_destroy(void)
{
        debugfs_remove_recursive(batadv_debugfs);
        batadv_debugfs = NULL;
}

/**
 * batadv_debugfs_add_hardif - creates the base directory for a hard interface
 *  in debugfs.
 * @hard_iface: hard interface which should be added.
 *
 * Return: 0 on success or negative error number in case of failure
 */
int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface)
{
        struct net *net = dev_net(hard_iface->net_dev);
        struct batadv_debuginfo **bat_debug;
        struct dentry *file;

        if (!batadv_debugfs)
                goto out;

        if (net != &init_net)
                return 0;

        hard_iface->debug_dir = debugfs_create_dir(hard_iface->net_dev->name,
                                                   batadv_debugfs);
        if (!hard_iface->debug_dir)
                goto out;

        for (bat_debug = batadv_hardif_debuginfos; *bat_debug; ++bat_debug) {
                file = debugfs_create_file(((*bat_debug)->attr).name,
                                           S_IFREG | ((*bat_debug)->attr).mode,
                                           hard_iface->debug_dir,
                                           hard_iface->net_dev,
                                           &(*bat_debug)->fops);
                if (!file)
                        goto rem_attr;
        }

        return 0;
rem_attr:
        debugfs_remove_recursive(hard_iface->debug_dir);
        hard_iface->debug_dir = NULL;
out:
        return -ENOMEM;
}

/**
 * batadv_debugfs_del_hardif - delete the base directory for a hard interface
 *  in debugfs.
 * @hard_iface: hard interface which is deleted.
 */
void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface)
{
        struct net *net = dev_net(hard_iface->net_dev);

        if (net != &init_net)
                return;

        if (batadv_debugfs) {
                debugfs_remove_recursive(hard_iface->debug_dir);
                hard_iface->debug_dir = NULL;
        }
}

int batadv_debugfs_add_meshif(struct net_device *dev)
{
        struct batadv_priv *bat_priv = netdev_priv(dev);
        struct batadv_debuginfo **bat_debug;
        struct net *net = dev_net(dev);
        struct dentry *file;

        if (!batadv_debugfs)
                goto out;

        if (net != &init_net)
                return 0;

        bat_priv->debug_dir = debugfs_create_dir(dev->name, batadv_debugfs);
        if (!bat_priv->debug_dir)
                goto out;

        if (batadv_socket_setup(bat_priv) < 0)
                goto rem_attr;

        if (batadv_debug_log_setup(bat_priv) < 0)
                goto rem_attr;

        for (bat_debug = batadv_mesh_debuginfos; *bat_debug; ++bat_debug) {
                file = debugfs_create_file(((*bat_debug)->attr).name,
                                           S_IFREG | ((*bat_debug)->attr).mode,
                                           bat_priv->debug_dir,
                                           dev, &(*bat_debug)->fops);
                if (!file) {
                        batadv_err(dev, "Can't add debugfs file: %s/%s\n",
                                   dev->name, ((*bat_debug)->attr).name);
                        goto rem_attr;
                }
        }

        if (batadv_nc_init_debugfs(bat_priv) < 0)
                goto rem_attr;

        return 0;
rem_attr:
        debugfs_remove_recursive(bat_priv->debug_dir);
        bat_priv->debug_dir = NULL;
out:
        return -ENOMEM;
}

void batadv_debugfs_del_meshif(struct net_device *dev)
{
        struct batadv_priv *bat_priv = netdev_priv(dev);
        struct net *net = dev_net(dev);

        if (net != &init_net)
                return;

        batadv_debug_log_cleanup(bat_priv);

        if (batadv_debugfs) {
                debugfs_remove_recursive(bat_priv->debug_dir);
                bat_priv->debug_dir = NULL;
        }
}