#include <linux/kmod.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/net_tstamp.h>
#include <linux/wireless.h>
#include <net/wext.h>

/*
 *      Map an interface index to its name (SIOCGIFNAME)
 */

/*
 *      We need this ioctl for efficient implementation of the
 *      if_indextoname() function required by the IPv6 API.  Without
 *      it, we would have to search all the interfaces to find a
 *      match.  --pb
 */

static int dev_ifname(struct net *net, struct ifreq __user *arg)
{
        struct ifreq ifr;
        int error;

        /*
         *      Fetch the caller's info block.
         */

        if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
                return -EFAULT;

        error = netdev_get_name(net, ifr.ifr_name, ifr.ifr_ifindex);
        if (error)
                return error;

        if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
                return -EFAULT;
        return 0;
}

static gifconf_func_t *gifconf_list[NPROTO];

/**
 *      register_gifconf        -       register a SIOCGIF handler
 *      @family: Address family
 *      @gifconf: Function handler
 *
 *      Register protocol dependent address dumping routines. The handler
 *      that is passed must not be freed or reused until it has been replaced
 *      by another handler.
 */
int register_gifconf(unsigned int family, gifconf_func_t *gifconf)
{
        if (family >= NPROTO)
                return -EINVAL;
        gifconf_list[family] = gifconf;
        return 0;
}
EXPORT_SYMBOL(register_gifconf);

/*
 *      Perform a SIOCGIFCONF call. This structure will change
 *      size eventually, and there is nothing I can do about it.
 *      Thus we will need a 'compatibility mode'.
 */

static int dev_ifconf(struct net *net, char __user *arg)
{
        struct ifconf ifc;
        struct net_device *dev;
        char __user *pos;
        int len;
        int total;
        int i;

        /*
         *      Fetch the caller's info block.
         */

        if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
                return -EFAULT;

        pos = ifc.ifc_buf;
        len = ifc.ifc_len;

        /*
         *      Loop over the interfaces, and write an info block for each.
         */

        total = 0;
        for_each_netdev(net, dev) {
                for (i = 0; i < NPROTO; i++) {
                        if (gifconf_list[i]) {
                                int done;
                                if (!pos)
                                        done = gifconf_list[i](dev, NULL, 0);
                                else
                                        done = gifconf_list[i](dev, pos + total,
                                                               len - total);
                                if (done < 0)
                                        return -EFAULT;
                                total += done;
                        }
                }
        }

        /*
         *      All done.  Write the updated control block back to the caller.
         */
        ifc.ifc_len = total;

        /*
         *      Both BSD and Solaris return 0 here, so we do too.
         */
        return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
}

/*
 *      Perform the SIOCxIFxxx calls, inside rcu_read_lock()
 */
static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
{
        int err;
        struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);

        if (!dev)
                return -ENODEV;

        switch (cmd) {
        case SIOCGIFFLAGS:      /* Get interface flags */
                ifr->ifr_flags = (short) dev_get_flags(dev);
                return 0;

        case SIOCGIFMETRIC:     /* Get the metric on the interface
                                   (currently unused) */
                ifr->ifr_metric = 0;
                return 0;

        case SIOCGIFMTU:        /* Get the MTU of a device */
                ifr->ifr_mtu = dev->mtu;
                return 0;

        case SIOCGIFHWADDR:
                if (!dev->addr_len)
                        memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
                else
                        memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
                               min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
                ifr->ifr_hwaddr.sa_family = dev->type;
                return 0;

        case SIOCGIFSLAVE:
                err = -EINVAL;
                break;

        case SIOCGIFMAP:
                ifr->ifr_map.mem_start = dev->mem_start;
                ifr->ifr_map.mem_end   = dev->mem_end;
                ifr->ifr_map.base_addr = dev->base_addr;
                ifr->ifr_map.irq       = dev->irq;
                ifr->ifr_map.dma       = dev->dma;
                ifr->ifr_map.port      = dev->if_port;
                return 0;

        case SIOCGIFINDEX:
                ifr->ifr_ifindex = dev->ifindex;
                return 0;

        case SIOCGIFTXQLEN:
                ifr->ifr_qlen = dev->tx_queue_len;
                return 0;

        default:
                /* dev_ioctl() should ensure this case
                 * is never reached
                 */
                WARN_ON(1);
                err = -ENOTTY;
                break;

        }
        return err;
}

static int net_hwtstamp_validate(struct ifreq *ifr)
{
        struct hwtstamp_config cfg;
        enum hwtstamp_tx_types tx_type;
        enum hwtstamp_rx_filters rx_filter;
        int tx_type_valid = 0;
        int rx_filter_valid = 0;

        if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
                return -EFAULT;

        if (cfg.flags) /* reserved for future extensions */
                return -EINVAL;

        tx_type = cfg.tx_type;
        rx_filter = cfg.rx_filter;

        switch (tx_type) {
        case HWTSTAMP_TX_OFF:
        case HWTSTAMP_TX_ON:
        case HWTSTAMP_TX_ONESTEP_SYNC:
                tx_type_valid = 1;
                break;
        }

        switch (rx_filter) {
        case HWTSTAMP_FILTER_NONE:
        case HWTSTAMP_FILTER_ALL:
        case HWTSTAMP_FILTER_SOME:
        case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
        case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
        case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
        case HWTSTAMP_FILTER_PTP_V2_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
                rx_filter_valid = 1;
                break;
        }

        if (!tx_type_valid || !rx_filter_valid)
                return -ERANGE;

        return 0;
}

/*
 *      Perform the SIOCxIFxxx calls, inside rtnl_lock()
 */
static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
{
        int err;
        struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
        const struct net_device_ops *ops;

        if (!dev)
                return -ENODEV;

        ops = dev->netdev_ops;

        switch (cmd) {
        case SIOCSIFFLAGS:      /* Set interface flags */
                return dev_change_flags(dev, ifr->ifr_flags);

        case SIOCSIFMETRIC:     /* Set the metric on the interface
                                   (currently unused) */
                return -EOPNOTSUPP;

        case SIOCSIFMTU:        /* Set the MTU of a device */
                return dev_set_mtu(dev, ifr->ifr_mtu);

        case SIOCSIFHWADDR:
                return dev_set_mac_address(dev, &ifr->ifr_hwaddr);

        case SIOCSIFHWBROADCAST:
                if (ifr->ifr_hwaddr.sa_family != dev->type)
                        return -EINVAL;
                memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
                       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
                call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
                return 0;

        case SIOCSIFMAP:
                if (ops->ndo_set_config) {
                        if (!netif_device_present(dev))
                                return -ENODEV;
                        return ops->ndo_set_config(dev, &ifr->ifr_map);
                }
                return -EOPNOTSUPP;

        case SIOCADDMULTI:
                if (!ops->ndo_set_rx_mode ||
                    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
                        return -EINVAL;
                if (!netif_device_present(dev))
                        return -ENODEV;
                return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);

        case SIOCDELMULTI:
                if (!ops->ndo_set_rx_mode ||
                    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
                        return -EINVAL;
                if (!netif_device_present(dev))
                        return -ENODEV;
                return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);

        case SIOCSIFTXQLEN:
                if (ifr->ifr_qlen < 0)
                        return -EINVAL;
                dev->tx_queue_len = ifr->ifr_qlen;
                return 0;

        case SIOCSIFNAME:
                ifr->ifr_newname[IFNAMSIZ-1] = '\0';
                return dev_change_name(dev, ifr->ifr_newname);

        case SIOCSHWTSTAMP:
                err = net_hwtstamp_validate(ifr);
                if (err)
                        return err;
                /* fall through */

        /*
         *      Unknown or private ioctl
         */
        default:
                if ((cmd >= SIOCDEVPRIVATE &&
                    cmd <= SIOCDEVPRIVATE + 15) ||
                    cmd == SIOCBONDENSLAVE ||
                    cmd == SIOCBONDRELEASE ||
                    cmd == SIOCBONDSETHWADDR ||
                    cmd == SIOCBONDSLAVEINFOQUERY ||
                    cmd == SIOCBONDINFOQUERY ||
                    cmd == SIOCBONDCHANGEACTIVE ||
                    cmd == SIOCGMIIPHY ||
                    cmd == SIOCGMIIREG ||
                    cmd == SIOCSMIIREG ||
                    cmd == SIOCBRADDIF ||
                    cmd == SIOCBRDELIF ||
                    cmd == SIOCSHWTSTAMP ||
                    cmd == SIOCWANDEV) {
                        err = -EOPNOTSUPP;
                        if (ops->ndo_do_ioctl) {
                                if (netif_device_present(dev))
                                        err = ops->ndo_do_ioctl(dev, ifr, cmd);
                                else
                                        err = -ENODEV;
                        }
                } else
                        err = -EINVAL;

        }
        return err;
}

/**
 *      dev_load        - load a network module
 *      @net: the applicable net namespace
 *      @name: name of interface
 *
 *      If a network interface is not present and the process has suitable
 *      privileges this function loads the module. If module loading is not
 *      available in this kernel then it becomes a nop.
 */

void dev_load(struct net *net, const char *name)
{
        struct net_device *dev;
        int no_module;

        rcu_read_lock();
        dev = dev_get_by_name_rcu(net, name);
        rcu_read_unlock();

        no_module = !dev;
        if (no_module && capable(CAP_NET_ADMIN))
                no_module = request_module("netdev-%s", name);
        if (no_module && capable(CAP_SYS_MODULE)) {
                if (!request_module("%s", name))
                        pr_warn("Loading kernel module for a network device with CAP_SYS_MODULE (deprecated).  Use CAP_NET_ADMIN and alias netdev-%s instead.\n",
                                name);
        }
}
EXPORT_SYMBOL(dev_load);

/*
 *      This function handles all "interface"-type I/O control requests. The actual
 *      'doing' part of this is dev_ifsioc above.
 */

/**
 *      dev_ioctl       -       network device ioctl
 *      @net: the applicable net namespace
 *      @cmd: command to issue
 *      @arg: pointer to a struct ifreq in user space
 *
 *      Issue ioctl functions to devices. This is normally called by the
 *      user space syscall interfaces but can sometimes be useful for
 *      other purposes. The return value is the return from the syscall if
 *      positive or a negative errno code on error.
 */

int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
{
        struct ifreq ifr;
        int ret;
        char *colon;

        /* One special case: SIOCGIFCONF takes ifconf argument
           and requires shared lock, because it sleeps writing
           to user space.
         */

        if (cmd == SIOCGIFCONF) {
                rtnl_lock();
                ret = dev_ifconf(net, (char __user *) arg);
                rtnl_unlock();
                return ret;
        }
        if (cmd == SIOCGIFNAME)
                return dev_ifname(net, (struct ifreq __user *)arg);

        if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
                return -EFAULT;

        ifr.ifr_name[IFNAMSIZ-1] = 0;

        colon = strchr(ifr.ifr_name, ':');
        if (colon)
                *colon = 0;

        /*
         *      See which interface the caller is talking about.
         */

        switch (cmd) {
        /*
         *      These ioctl calls:
         *      - can be done by all.
         *      - atomic and do not require locking.
         *      - return a value
         */
        case SIOCGIFFLAGS:
        case SIOCGIFMETRIC:
        case SIOCGIFMTU:
        case SIOCGIFHWADDR:
        case SIOCGIFSLAVE:
        case SIOCGIFMAP:
        case SIOCGIFINDEX:
        case SIOCGIFTXQLEN:
                dev_load(net, ifr.ifr_name);
                rcu_read_lock();
                ret = dev_ifsioc_locked(net, &ifr, cmd);
                rcu_read_unlock();
                if (!ret) {
                        if (colon)
                                *colon = ':';
                        if (copy_to_user(arg, &ifr,
                                         sizeof(struct ifreq)))
                                ret = -EFAULT;
                }
                return ret;

        case SIOCETHTOOL:
                dev_load(net, ifr.ifr_name);
                rtnl_lock();
                ret = dev_ethtool(net, &ifr);
                rtnl_unlock();
                if (!ret) {
                        if (colon)
                                *colon = ':';
                        if (copy_to_user(arg, &ifr,
                                         sizeof(struct ifreq)))
                                ret = -EFAULT;
                }
                return ret;

        /*
         *      These ioctl calls:
         *      - require superuser power.
         *      - require strict serialization.
         *      - return a value
         */
        case SIOCGMIIPHY:
        case SIOCGMIIREG:
        case SIOCSIFNAME:
                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
                        return -EPERM;
                dev_load(net, ifr.ifr_name);
                rtnl_lock();
                ret = dev_ifsioc(net, &ifr, cmd);
                rtnl_unlock();
                if (!ret) {
                        if (colon)
                                *colon = ':';
                        if (copy_to_user(arg, &ifr,
                                         sizeof(struct ifreq)))
                                ret = -EFAULT;
                }
                return ret;

        /*
         *      These ioctl calls:
         *      - require superuser power.
         *      - require strict serialization.
         *      - do not return a value
         */
        case SIOCSIFMAP:
        case SIOCSIFTXQLEN:
                if (!capable(CAP_NET_ADMIN))
                        return -EPERM;
                /* fall through */
        /*
         *      These ioctl calls:
         *      - require local superuser power.
         *      - require strict serialization.
         *      - do not return a value
         */
        case SIOCSIFFLAGS:
        case SIOCSIFMETRIC:
        case SIOCSIFMTU:
        case SIOCSIFHWADDR:
        case SIOCSIFSLAVE:
        case SIOCADDMULTI:
        case SIOCDELMULTI:
        case SIOCSIFHWBROADCAST:
        case SIOCSMIIREG:
        case SIOCBONDENSLAVE:
        case SIOCBONDRELEASE:
        case SIOCBONDSETHWADDR:
        case SIOCBONDCHANGEACTIVE:
        case SIOCBRADDIF:
        case SIOCBRDELIF:
        case SIOCSHWTSTAMP:
                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
                        return -EPERM;
                /* fall through */
        case SIOCBONDSLAVEINFOQUERY:
        case SIOCBONDINFOQUERY:
                dev_load(net, ifr.ifr_name);
                rtnl_lock();
                ret = dev_ifsioc(net, &ifr, cmd);
                rtnl_unlock();
                return ret;

        case SIOCGIFMEM:
                /* Get the per device memory space. We can add this but
                 * currently do not support it */
        case SIOCSIFMEM:
                /* Set the per device memory buffer space.
                 * Not applicable in our case */
        case SIOCSIFLINK:
                return -ENOTTY;

        /*
         *      Unknown or private ioctl.
         */
        default:
                if (cmd == SIOCWANDEV ||
                    (cmd >= SIOCDEVPRIVATE &&
                     cmd <= SIOCDEVPRIVATE + 15)) {
                        dev_load(net, ifr.ifr_name);
                        rtnl_lock();
                        ret = dev_ifsioc(net, &ifr, cmd);
                        rtnl_unlock();
                        if (!ret && copy_to_user(arg, &ifr,
                                                 sizeof(struct ifreq)))
                                ret = -EFAULT;
                        return ret;
                }
                /* Take care of Wireless Extensions */
                if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
                        return wext_handle_ioctl(net, &ifr, cmd, arg);
                return -ENOTTY;
        }
}