// SPDX-License-Identifier: GPL-2.0-or-later
/******************************************************************************
 * vlanproc.c   VLAN Module. /proc filesystem interface.
 *
 *              This module is completely hardware-independent and provides
 *              access to the router using Linux /proc filesystem.
 *
 * Author:      Ben Greear, <greearb@candelatech.com> coppied from wanproc.c
 *               by: Gene Kozin <genek@compuserve.com>
 *
 * Copyright:   (c) 1998 Ben Greear
 *
 * ============================================================================
 * Jan 20, 1998        Ben Greear     Initial Version
 *****************************************************************************/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/fs.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include "vlanproc.h"
#include "vlan.h"

/****** Function Prototypes *************************************************/

/* Methods for preparing data for reading proc entries */
static int vlan_seq_show(struct seq_file *seq, void *v);
static void *vlan_seq_start(struct seq_file *seq, loff_t *pos);
static void *vlan_seq_next(struct seq_file *seq, void *v, loff_t *pos);
static void vlan_seq_stop(struct seq_file *seq, void *);
static int vlandev_seq_show(struct seq_file *seq, void *v);

/*
 *      Global Data
 */


/*
 *      Names of the proc directory entries
 */

static const char name_root[]    = "vlan";
static const char name_conf[]    = "config";

/*
 *      Structures for interfacing with the /proc filesystem.
 *      VLAN creates its own directory /proc/net/vlan with the following
 *      entries:
 *      config          device status/configuration
 *      <device>        entry for each  device
 */

/*
 *      Generic /proc/net/vlan/<file> file and inode operations
 */

static const struct seq_operations vlan_seq_ops = {
        .start = vlan_seq_start,
        .next = vlan_seq_next,
        .stop = vlan_seq_stop,
        .show = vlan_seq_show,
};

/*
 * Proc filesystem directory entries.
 */

/* Strings */
static const char *const vlan_name_type_str[VLAN_NAME_TYPE_HIGHEST] = {
    [VLAN_NAME_TYPE_RAW_PLUS_VID]        = "VLAN_NAME_TYPE_RAW_PLUS_VID",
    [VLAN_NAME_TYPE_PLUS_VID_NO_PAD]     = "VLAN_NAME_TYPE_PLUS_VID_NO_PAD",
    [VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD] = "VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD",
    [VLAN_NAME_TYPE_PLUS_VID]            = "VLAN_NAME_TYPE_PLUS_VID",
};
/*
 *      Interface functions
 */

/*
 *      Clean up /proc/net/vlan entries
 */

void vlan_proc_cleanup(struct net *net)
{
        struct vlan_net *vn = net_generic(net, vlan_net_id);

        if (vn->proc_vlan_conf)
                remove_proc_entry(name_conf, vn->proc_vlan_dir);

        if (vn->proc_vlan_dir)
                remove_proc_entry(name_root, net->proc_net);

        /* Dynamically added entries should be cleaned up as their vlan_device
         * is removed, so we should not have to take care of it here...
         */
}

/*
 *      Create /proc/net/vlan entries
 */

int __net_init vlan_proc_init(struct net *net)
{
        struct vlan_net *vn = net_generic(net, vlan_net_id);

        vn->proc_vlan_dir = proc_net_mkdir(net, name_root, net->proc_net);
        if (!vn->proc_vlan_dir)
                goto err;

        vn->proc_vlan_conf = proc_create_net(name_conf, S_IFREG | 0600,
                        vn->proc_vlan_dir, &vlan_seq_ops,
                        sizeof(struct seq_net_private));
        if (!vn->proc_vlan_conf)
                goto err;
        return 0;

err:
        pr_err("can't create entry in proc filesystem!\n");
        vlan_proc_cleanup(net);
        return -ENOBUFS;
}

/*
 *      Add directory entry for VLAN device.
 */

int vlan_proc_add_dev(struct net_device *vlandev)
{
        struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);
        struct vlan_net *vn = net_generic(dev_net(vlandev), vlan_net_id);

        if (!strcmp(vlandev->name, name_conf))
                return -EINVAL;
        vlan->dent = proc_create_single_data(vlandev->name, S_IFREG | 0600,
                        vn->proc_vlan_dir, vlandev_seq_show, vlandev);
        if (!vlan->dent)
                return -ENOBUFS;
        return 0;
}

/*
 *      Delete directory entry for VLAN device.
 */
void vlan_proc_rem_dev(struct net_device *vlandev)
{
        /** NOTE:  This will consume the memory pointed to by dent, it seems. */
        proc_remove(vlan_dev_priv(vlandev)->dent);
        vlan_dev_priv(vlandev)->dent = NULL;
}

/****** Proc filesystem entry points ****************************************/

/*
 * The following few functions build the content of /proc/net/vlan/config
 */

/* start read of /proc/net/vlan/config */
static void *vlan_seq_start(struct seq_file *seq, loff_t *pos)
        __acquires(rcu)
{
        struct net_device *dev;
        struct net *net = seq_file_net(seq);
        loff_t i = 1;

        rcu_read_lock();
        if (*pos == 0)
                return SEQ_START_TOKEN;

        for_each_netdev_rcu(net, dev) {
                if (!is_vlan_dev(dev))
                        continue;

                if (i++ == *pos)
                        return dev;
        }

        return  NULL;
}

static void *vlan_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
        struct net_device *dev;
        struct net *net = seq_file_net(seq);

        ++*pos;

        dev = v;
        if (v == SEQ_START_TOKEN)
                dev = net_device_entry(&net->dev_base_head);

        for_each_netdev_continue_rcu(net, dev) {
                if (!is_vlan_dev(dev))
                        continue;

                return dev;
        }

        return NULL;
}

static void vlan_seq_stop(struct seq_file *seq, void *v)
        __releases(rcu)
{
        rcu_read_unlock();
}

static int vlan_seq_show(struct seq_file *seq, void *v)
{
        struct net *net = seq_file_net(seq);
        struct vlan_net *vn = net_generic(net, vlan_net_id);

        if (v == SEQ_START_TOKEN) {
                const char *nmtype = NULL;

                seq_puts(seq, "VLAN Dev name     | VLAN ID\n");

                if (vn->name_type < ARRAY_SIZE(vlan_name_type_str))
                    nmtype =  vlan_name_type_str[vn->name_type];

                seq_printf(seq, "Name-Type: %s\n",
                           nmtype ? nmtype :  "UNKNOWN");
        } else {
                const struct net_device *vlandev = v;
                const struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);

                seq_printf(seq, "%-15s| %d  | %s\n",  vlandev->name,
                           vlan->vlan_id,    vlan->real_dev->name);
        }
        return 0;
}

static int vlandev_seq_show(struct seq_file *seq, void *offset)
{
        struct net_device *vlandev = (struct net_device *) seq->private;
        const struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);
        struct rtnl_link_stats64 temp;
        const struct rtnl_link_stats64 *stats;
        static const char fmt64[] = "%30s %12llu\n";
        int i;

        if (!is_vlan_dev(vlandev))
                return 0;

        stats = dev_get_stats(vlandev, &temp);
        seq_printf(seq,
                   "%s  VID: %d  REORDER_HDR: %i  dev->priv_flags: %hx\n",
                   vlandev->name, vlan->vlan_id,
                   (int)(vlan->flags & 1), vlandev->priv_flags);

        seq_printf(seq, fmt64, "total frames received", stats->rx_packets);
        seq_printf(seq, fmt64, "total bytes received", stats->rx_bytes);
        seq_printf(seq, fmt64, "Broadcast/Multicast Rcvd", stats->multicast);
        seq_puts(seq, "\n");
        seq_printf(seq, fmt64, "total frames transmitted", stats->tx_packets);
        seq_printf(seq, fmt64, "total bytes transmitted", stats->tx_bytes);
        seq_printf(seq, "Device: %s", vlan->real_dev->name);
        /* now show all PRIORITY mappings relating to this VLAN */
        seq_printf(seq, "\nINGRESS priority mappings: "
                        "0:%u  1:%u  2:%u  3:%u  4:%u  5:%u  6:%u 7:%u\n",
                   vlan->ingress_priority_map[0],
                   vlan->ingress_priority_map[1],
                   vlan->ingress_priority_map[2],
                   vlan->ingress_priority_map[3],
                   vlan->ingress_priority_map[4],
                   vlan->ingress_priority_map[5],
                   vlan->ingress_priority_map[6],
                   vlan->ingress_priority_map[7]);

        seq_printf(seq, " EGRESS priority mappings: ");
        for (i = 0; i < 16; i++) {
                const struct vlan_priority_tci_mapping *mp
                        = vlan->egress_priority_map[i];
                while (mp) {
                        seq_printf(seq, "%u:%hu ",
                                   mp->priority, ((mp->vlan_qos >> 13) & 0x7));
                        mp = mp->next;
                }
        }
        seq_puts(seq, "\n");

        return 0;
}