root/drivers/net/netdevsim/udp_tunnels.c
// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2020 Facebook Inc.

#include <linux/debugfs.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <net/udp_tunnel.h>

#include "netdevsim.h"

static int
nsim_udp_tunnel_set_port(struct net_device *dev, unsigned int table,
                         unsigned int entry, struct udp_tunnel_info *ti)
{
        struct netdevsim *ns = netdev_priv(dev);
        int ret;

        ret = -ns->udp_ports.inject_error;
        ns->udp_ports.inject_error = 0;

        if (!ret) {
                if (ns->udp_ports.ports[table][entry]) {
                        WARN(1, "entry already in use\n");
                        ret = -EBUSY;
                } else {
                        ns->udp_ports.ports[table][entry] =
                                be16_to_cpu(ti->port) << 16 | ti->type;
                }
        }

        netdev_info(dev, "set [%d, %d] type %d family %d port %d - %d\n",
                    table, entry, ti->type, ti->sa_family, ntohs(ti->port),
                    ret);
        return ret;
}

static int
nsim_udp_tunnel_unset_port(struct net_device *dev, unsigned int table,
                           unsigned int entry, struct udp_tunnel_info *ti)
{
        struct netdevsim *ns = netdev_priv(dev);
        int ret;

        ret = -ns->udp_ports.inject_error;
        ns->udp_ports.inject_error = 0;

        if (!ret) {
                u32 val = be16_to_cpu(ti->port) << 16 | ti->type;

                if (val == ns->udp_ports.ports[table][entry]) {
                        ns->udp_ports.ports[table][entry] = 0;
                } else {
                        WARN(1, "entry not installed %x vs %x\n",
                             val, ns->udp_ports.ports[table][entry]);
                        ret = -ENOENT;
                }
        }

        netdev_info(dev, "unset [%d, %d] type %d family %d port %d - %d\n",
                    table, entry, ti->type, ti->sa_family, ntohs(ti->port),
                    ret);
        return ret;
}

static int
nsim_udp_tunnel_sync_table(struct net_device *dev, unsigned int table)
{
        struct netdevsim *ns = netdev_priv(dev);
        struct udp_tunnel_info ti;
        unsigned int i;
        int ret;

        ret = -ns->udp_ports.inject_error;
        ns->udp_ports.inject_error = 0;

        for (i = 0; i < NSIM_UDP_TUNNEL_N_PORTS; i++) {
                udp_tunnel_nic_get_port(dev, table, i, &ti);
                ns->udp_ports.ports[table][i] =
                        be16_to_cpu(ti.port) << 16 | ti.type;
        }

        return ret;
}

static const struct udp_tunnel_nic_info nsim_udp_tunnel_info = {
        .set_port       = nsim_udp_tunnel_set_port,
        .unset_port     = nsim_udp_tunnel_unset_port,
        .sync_table     = nsim_udp_tunnel_sync_table,

        .tables = {
                {
                        .n_entries      = NSIM_UDP_TUNNEL_N_PORTS,
                        .tunnel_types   = UDP_TUNNEL_TYPE_VXLAN,
                },
                {
                        .n_entries      = NSIM_UDP_TUNNEL_N_PORTS,
                        .tunnel_types   = UDP_TUNNEL_TYPE_GENEVE |
                                          UDP_TUNNEL_TYPE_VXLAN_GPE,
                },
        },
};

static ssize_t
nsim_udp_tunnels_info_reset_write(struct file *file, const char __user *data,
                                  size_t count, loff_t *ppos)
{
        struct net_device *dev = file->private_data;
        struct netdevsim *ns = netdev_priv(dev);

        if (dev->reg_state == NETREG_REGISTERED) {
                memset(ns->udp_ports.ports, 0, sizeof(ns->udp_ports.__ports));
                udp_tunnel_nic_reset_ntf(dev);
        }

        return count;
}

static const struct file_operations nsim_udp_tunnels_info_reset_fops = {
        .open = simple_open,
        .write = nsim_udp_tunnels_info_reset_write,
        .llseek = generic_file_llseek,
        .owner = THIS_MODULE,
};

int nsim_udp_tunnels_info_create(struct nsim_dev *nsim_dev,
                                 struct net_device *dev)
{
        struct netdevsim *ns = netdev_priv(dev);
        struct udp_tunnel_nic_info *info;

        if (nsim_dev->udp_ports.shared && nsim_dev->udp_ports.open_only) {
                dev_err(&nsim_dev->nsim_bus_dev->dev,
                        "shared can't be used in conjunction with open_only\n");
                return -EINVAL;
        }

        if (!nsim_dev->udp_ports.shared)
                ns->udp_ports.ports = ns->udp_ports.__ports;
        else
                ns->udp_ports.ports = nsim_dev->udp_ports.__ports;

        ns->udp_ports.ddir = debugfs_create_dir("udp_ports",
                                                ns->nsim_dev_port->ddir);

        debugfs_create_u32("inject_error", 0600, ns->udp_ports.ddir,
                           &ns->udp_ports.inject_error);

        ns->udp_ports.dfs_ports[0].array = ns->udp_ports.ports[0];
        ns->udp_ports.dfs_ports[0].n_elements = NSIM_UDP_TUNNEL_N_PORTS;
        debugfs_create_u32_array("table0", 0400, ns->udp_ports.ddir,
                                 &ns->udp_ports.dfs_ports[0]);

        ns->udp_ports.dfs_ports[1].array = ns->udp_ports.ports[1];
        ns->udp_ports.dfs_ports[1].n_elements = NSIM_UDP_TUNNEL_N_PORTS;
        debugfs_create_u32_array("table1", 0400, ns->udp_ports.ddir,
                                 &ns->udp_ports.dfs_ports[1]);

        debugfs_create_file("reset", 0200, ns->udp_ports.ddir,
                            dev, &nsim_udp_tunnels_info_reset_fops);

        /* Note: it's not normal to allocate the info struct like this!
         * Drivers are expected to use a static const one, here we're testing.
         */
        info = kmemdup(&nsim_udp_tunnel_info, sizeof(nsim_udp_tunnel_info),
                       GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        if (nsim_dev->udp_ports.sync_all) {
                info->set_port = NULL;
                info->unset_port = NULL;
        } else {
                info->sync_table = NULL;
        }

        if (nsim_dev->udp_ports.open_only)
                info->flags |= UDP_TUNNEL_NIC_INFO_OPEN_ONLY;
        if (nsim_dev->udp_ports.ipv4_only)
                info->flags |= UDP_TUNNEL_NIC_INFO_IPV4_ONLY;
        if (nsim_dev->udp_ports.shared)
                info->shared = &nsim_dev->udp_ports.utn_shared;
        if (nsim_dev->udp_ports.static_iana_vxlan)
                info->flags |= UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN;

        dev->udp_tunnel_nic_info = info;
        return 0;
}

void nsim_udp_tunnels_info_destroy(struct net_device *dev)
{
        struct netdevsim *ns = netdev_priv(dev);

        debugfs_remove_recursive(ns->udp_ports.ddir);
        kfree(dev->udp_tunnel_nic_info);
        dev->udp_tunnel_nic_info = NULL;
}

void nsim_udp_tunnels_debugfs_create(struct nsim_dev *nsim_dev)
{
        debugfs_create_bool("udp_ports_sync_all", 0600, nsim_dev->ddir,
                            &nsim_dev->udp_ports.sync_all);
        debugfs_create_bool("udp_ports_open_only", 0600, nsim_dev->ddir,
                            &nsim_dev->udp_ports.open_only);
        debugfs_create_bool("udp_ports_ipv4_only", 0600, nsim_dev->ddir,
                            &nsim_dev->udp_ports.ipv4_only);
        debugfs_create_bool("udp_ports_shared", 0600, nsim_dev->ddir,
                            &nsim_dev->udp_ports.shared);
        debugfs_create_bool("udp_ports_static_iana_vxlan", 0600, nsim_dev->ddir,
                            &nsim_dev->udp_ports.static_iana_vxlan);
}