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rtnetlink.c

/*
 * INET           An implementation of the TCP/IP protocol suite for the LINUX
 *          operating system.  INET is implemented using the  BSD Socket
 *          interface as the means of communication with the user level.
 *
 *          Routing netlink socket interface: protocol independent part.
 *
 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *          This program is free software; you can redistribute it and/or
 *          modify it under the terms of the GNU General Public License
 *          as published by the Free Software Foundation; either version
 *          2 of the License, or (at your option) any later version.
 *
 *    Fixes:
 *    Vitaly E. Lavrov        RTA_OK arithmetics was wrong.
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/capability.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/security.h>
#include <linux/mutex.h>
#include <linux/if_addr.h>
#include <linux/nsproxy.h>

#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/string.h>

#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/arp.h>
#include <net/route.h>
#include <net/udp.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
#include <net/fib_rules.h>
#include <net/rtnetlink.h>

struct rtnl_link
{
      rtnl_doit_func          doit;
      rtnl_dumpit_func  dumpit;
};

static DEFINE_MUTEX(rtnl_mutex);
static struct sock *rtnl;

void rtnl_lock(void)
{
      mutex_lock(&rtnl_mutex);
}

void __rtnl_unlock(void)
{
      mutex_unlock(&rtnl_mutex);
}

void rtnl_unlock(void)
{
      mutex_unlock(&rtnl_mutex);
      netdev_run_todo();
}

int rtnl_trylock(void)
{
      return mutex_trylock(&rtnl_mutex);
}

int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
{
      memset(tb, 0, sizeof(struct rtattr*)*maxattr);

      while (RTA_OK(rta, len)) {
            unsigned flavor = rta->rta_type;
            if (flavor && flavor <= maxattr)
                  tb[flavor-1] = rta;
            rta = RTA_NEXT(rta, len);
      }
      return 0;
}

int __rtattr_parse_nested_compat(struct rtattr *tb[], int maxattr,
                         struct rtattr *rta, int len)
{
      if (RTA_PAYLOAD(rta) < len)
            return -1;
      if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
            rta = RTA_DATA(rta) + RTA_ALIGN(len);
            return rtattr_parse_nested(tb, maxattr, rta);
      }
      memset(tb, 0, sizeof(struct rtattr *) * maxattr);
      return 0;
}

static struct rtnl_link *rtnl_msg_handlers[NPROTO];

static inline int rtm_msgindex(int msgtype)
{
      int msgindex = msgtype - RTM_BASE;

      /*
       * msgindex < 0 implies someone tried to register a netlink
       * control code. msgindex >= RTM_NR_MSGTYPES may indicate that
       * the message type has not been added to linux/rtnetlink.h
       */
      BUG_ON(msgindex < 0 || msgindex >= RTM_NR_MSGTYPES);

      return msgindex;
}

static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
{
      struct rtnl_link *tab;

      tab = rtnl_msg_handlers[protocol];
      if (tab == NULL || tab[msgindex].doit == NULL)
            tab = rtnl_msg_handlers[PF_UNSPEC];

      return tab ? tab[msgindex].doit : NULL;
}

static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
{
      struct rtnl_link *tab;

      tab = rtnl_msg_handlers[protocol];
      if (tab == NULL || tab[msgindex].dumpit == NULL)
            tab = rtnl_msg_handlers[PF_UNSPEC];

      return tab ? tab[msgindex].dumpit : NULL;
}

/**
 * __rtnl_register - Register a rtnetlink message type
 * @protocol: Protocol family or PF_UNSPEC
 * @msgtype: rtnetlink message type
 * @doit: Function pointer called for each request message
 * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
 *
 * Registers the specified function pointers (at least one of them has
 * to be non-NULL) to be called whenever a request message for the
 * specified protocol family and message type is received.
 *
 * The special protocol family PF_UNSPEC may be used to define fallback
 * function pointers for the case when no entry for the specific protocol
 * family exists.
 *
 * Returns 0 on success or a negative error code.
 */
int __rtnl_register(int protocol, int msgtype,
                rtnl_doit_func doit, rtnl_dumpit_func dumpit)
{
      struct rtnl_link *tab;
      int msgindex;

      BUG_ON(protocol < 0 || protocol >= NPROTO);
      msgindex = rtm_msgindex(msgtype);

      tab = rtnl_msg_handlers[protocol];
      if (tab == NULL) {
            tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL);
            if (tab == NULL)
                  return -ENOBUFS;

            rtnl_msg_handlers[protocol] = tab;
      }

      if (doit)
            tab[msgindex].doit = doit;

      if (dumpit)
            tab[msgindex].dumpit = dumpit;

      return 0;
}

EXPORT_SYMBOL_GPL(__rtnl_register);

/**
 * rtnl_register - Register a rtnetlink message type
 *
 * Identical to __rtnl_register() but panics on failure. This is useful
 * as failure of this function is very unlikely, it can only happen due
 * to lack of memory when allocating the chain to store all message
 * handlers for a protocol. Meant for use in init functions where lack
 * of memory implies no sense in continueing.
 */
void rtnl_register(int protocol, int msgtype,
               rtnl_doit_func doit, rtnl_dumpit_func dumpit)
{
      if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
            panic("Unable to register rtnetlink message handler, "
                  "protocol = %d, message type = %d\n",
                  protocol, msgtype);
}

EXPORT_SYMBOL_GPL(rtnl_register);

/**
 * rtnl_unregister - Unregister a rtnetlink message type
 * @protocol: Protocol family or PF_UNSPEC
 * @msgtype: rtnetlink message type
 *
 * Returns 0 on success or a negative error code.
 */
int rtnl_unregister(int protocol, int msgtype)
{
      int msgindex;

      BUG_ON(protocol < 0 || protocol >= NPROTO);
      msgindex = rtm_msgindex(msgtype);

      if (rtnl_msg_handlers[protocol] == NULL)
            return -ENOENT;

      rtnl_msg_handlers[protocol][msgindex].doit = NULL;
      rtnl_msg_handlers[protocol][msgindex].dumpit = NULL;

      return 0;
}

EXPORT_SYMBOL_GPL(rtnl_unregister);

/**
 * rtnl_unregister_all - Unregister all rtnetlink message type of a protocol
 * @protocol : Protocol family or PF_UNSPEC
 *
 * Identical to calling rtnl_unregster() for all registered message types
 * of a certain protocol family.
 */
void rtnl_unregister_all(int protocol)
{
      BUG_ON(protocol < 0 || protocol >= NPROTO);

      kfree(rtnl_msg_handlers[protocol]);
      rtnl_msg_handlers[protocol] = NULL;
}

EXPORT_SYMBOL_GPL(rtnl_unregister_all);

static LIST_HEAD(link_ops);

/**
 * __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
 * @ops: struct rtnl_link_ops * to register
 *
 * The caller must hold the rtnl_mutex. This function should be used
 * by drivers that create devices during module initialization. It
 * must be called before registering the devices.
 *
 * Returns 0 on success or a negative error code.
 */
int __rtnl_link_register(struct rtnl_link_ops *ops)
{
      if (!ops->dellink)
            ops->dellink = unregister_netdevice;

      list_add_tail(&ops->list, &link_ops);
      return 0;
}

EXPORT_SYMBOL_GPL(__rtnl_link_register);

/**
 * rtnl_link_register - Register rtnl_link_ops with rtnetlink.
 * @ops: struct rtnl_link_ops * to register
 *
 * Returns 0 on success or a negative error code.
 */
int rtnl_link_register(struct rtnl_link_ops *ops)
{
      int err;

      rtnl_lock();
      err = __rtnl_link_register(ops);
      rtnl_unlock();
      return err;
}

EXPORT_SYMBOL_GPL(rtnl_link_register);

/**
 * __rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
 * @ops: struct rtnl_link_ops * to unregister
 *
 * The caller must hold the rtnl_mutex.
 */
void __rtnl_link_unregister(struct rtnl_link_ops *ops)
{
      struct net_device *dev, *n;
      struct net *net;

      for_each_net(net) {
restart:
            for_each_netdev_safe(net, dev, n) {
                  if (dev->rtnl_link_ops == ops) {
                        ops->dellink(dev);
                        goto restart;
                  }
            }
      }
      list_del(&ops->list);
}

EXPORT_SYMBOL_GPL(__rtnl_link_unregister);

/**
 * rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
 * @ops: struct rtnl_link_ops * to unregister
 */
void rtnl_link_unregister(struct rtnl_link_ops *ops)
{
      rtnl_lock();
      __rtnl_link_unregister(ops);
      rtnl_unlock();
}

EXPORT_SYMBOL_GPL(rtnl_link_unregister);

static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
{
      const struct rtnl_link_ops *ops;

      list_for_each_entry(ops, &link_ops, list) {
            if (!strcmp(ops->kind, kind))
                  return ops;
      }
      return NULL;
}

static size_t rtnl_link_get_size(const struct net_device *dev)
{
      const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
      size_t size;

      if (!ops)
            return 0;

      size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */
             nlmsg_total_size(strlen(ops->kind) + 1);  /* IFLA_INFO_KIND */

      if (ops->get_size)
            /* IFLA_INFO_DATA + nested data */
            size += nlmsg_total_size(sizeof(struct nlattr)) +
                  ops->get_size(dev);

      if (ops->get_xstats_size)
            size += ops->get_xstats_size(dev);  /* IFLA_INFO_XSTATS */

      return size;
}

static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
{
      const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
      struct nlattr *linkinfo, *data;
      int err = -EMSGSIZE;

      linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
      if (linkinfo == NULL)
            goto out;

      if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
            goto err_cancel_link;
      if (ops->fill_xstats) {
            err = ops->fill_xstats(skb, dev);
            if (err < 0)
                  goto err_cancel_link;
      }
      if (ops->fill_info) {
            data = nla_nest_start(skb, IFLA_INFO_DATA);
            if (data == NULL)
                  goto err_cancel_link;
            err = ops->fill_info(skb, dev);
            if (err < 0)
                  goto err_cancel_data;
            nla_nest_end(skb, data);
      }

      nla_nest_end(skb, linkinfo);
      return 0;

err_cancel_data:
      nla_nest_cancel(skb, data);
err_cancel_link:
      nla_nest_cancel(skb, linkinfo);
out:
      return err;
}

static const int rtm_min[RTM_NR_FAMILIES] =
{
      [RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
      [RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
      [RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
      [RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
      [RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
      [RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
      [RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
      [RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
      [RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
      [RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
};

static const int rta_max[RTM_NR_FAMILIES] =
{
      [RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
      [RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
      [RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
      [RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
      [RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
      [RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
      [RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
      [RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
};

void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
{
      struct rtattr *rta;
      int size = RTA_LENGTH(attrlen);

      rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
      rta->rta_type = attrtype;
      rta->rta_len = size;
      memcpy(RTA_DATA(rta), data, attrlen);
      memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
}

size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
{
      size_t ret = RTA_PAYLOAD(rta);
      char *src = RTA_DATA(rta);

      if (ret > 0 && src[ret - 1] == '\0')
            ret--;
      if (size > 0) {
            size_t len = (ret >= size) ? size - 1 : ret;
            memset(dest, 0, size);
            memcpy(dest, src, len);
      }
      return ret;
}

int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
{
      int err = 0;

      NETLINK_CB(skb).dst_group = group;
      if (echo)
            atomic_inc(&skb->users);
      netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
      if (echo)
            err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
      return err;
}

int rtnl_unicast(struct sk_buff *skb, u32 pid)
{
      return nlmsg_unicast(rtnl, skb, pid);
}

int rtnl_notify(struct sk_buff *skb, u32 pid, u32 group,
            struct nlmsghdr *nlh, gfp_t flags)
{
      int report = 0;

      if (nlh)
            report = nlmsg_report(nlh);

      return nlmsg_notify(rtnl, skb, pid, group, report, flags);
}

void rtnl_set_sk_err(u32 group, int error)
{
      netlink_set_err(rtnl, 0, group, error);
}

int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
{
      struct nlattr *mx;
      int i, valid = 0;

      mx = nla_nest_start(skb, RTA_METRICS);
      if (mx == NULL)
            return -ENOBUFS;

      for (i = 0; i < RTAX_MAX; i++) {
            if (metrics[i]) {
                  valid++;
                  NLA_PUT_U32(skb, i+1, metrics[i]);
            }
      }

      if (!valid) {
            nla_nest_cancel(skb, mx);
            return 0;
      }

      return nla_nest_end(skb, mx);

nla_put_failure:
      return nla_nest_cancel(skb, mx);
}

int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
                   u32 ts, u32 tsage, long expires, u32 error)
{
      struct rta_cacheinfo ci = {
            .rta_lastuse = jiffies_to_clock_t(jiffies - dst->lastuse),
            .rta_used = dst->__use,
            .rta_clntref = atomic_read(&(dst->__refcnt)),
            .rta_error = error,
            .rta_id =  id,
            .rta_ts = ts,
            .rta_tsage = tsage,
      };

      if (expires)
            ci.rta_expires = jiffies_to_clock_t(expires);

      return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
}

EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo);

static void set_operstate(struct net_device *dev, unsigned char transition)
{
      unsigned char operstate = dev->operstate;

      switch(transition) {
      case IF_OPER_UP:
            if ((operstate == IF_OPER_DORMANT ||
                 operstate == IF_OPER_UNKNOWN) &&
                !netif_dormant(dev))
                  operstate = IF_OPER_UP;
            break;

      case IF_OPER_DORMANT:
            if (operstate == IF_OPER_UP ||
                operstate == IF_OPER_UNKNOWN)
                  operstate = IF_OPER_DORMANT;
            break;
      }

      if (dev->operstate != operstate) {
            write_lock_bh(&dev_base_lock);
            dev->operstate = operstate;
            write_unlock_bh(&dev_base_lock);
            netdev_state_change(dev);
      }
}

static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
                         struct net_device_stats *b)
{
      a->rx_packets = b->rx_packets;
      a->tx_packets = b->tx_packets;
      a->rx_bytes = b->rx_bytes;
      a->tx_bytes = b->tx_bytes;
      a->rx_errors = b->rx_errors;
      a->tx_errors = b->tx_errors;
      a->rx_dropped = b->rx_dropped;
      a->tx_dropped = b->tx_dropped;

      a->multicast = b->multicast;
      a->collisions = b->collisions;

      a->rx_length_errors = b->rx_length_errors;
      a->rx_over_errors = b->rx_over_errors;
      a->rx_crc_errors = b->rx_crc_errors;
      a->rx_frame_errors = b->rx_frame_errors;
      a->rx_fifo_errors = b->rx_fifo_errors;
      a->rx_missed_errors = b->rx_missed_errors;

      a->tx_aborted_errors = b->tx_aborted_errors;
      a->tx_carrier_errors = b->tx_carrier_errors;
      a->tx_fifo_errors = b->tx_fifo_errors;
      a->tx_heartbeat_errors = b->tx_heartbeat_errors;
      a->tx_window_errors = b->tx_window_errors;

      a->rx_compressed = b->rx_compressed;
      a->tx_compressed = b->tx_compressed;
};

static inline size_t if_nlmsg_size(const struct net_device *dev)
{
      return NLMSG_ALIGN(sizeof(struct ifinfomsg))
             + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
             + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
             + nla_total_size(sizeof(struct rtnl_link_ifmap))
             + nla_total_size(sizeof(struct rtnl_link_stats))
             + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
             + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
             + nla_total_size(4) /* IFLA_TXQLEN */
             + nla_total_size(4) /* IFLA_WEIGHT */
             + nla_total_size(4) /* IFLA_MTU */
             + nla_total_size(4) /* IFLA_LINK */
             + nla_total_size(4) /* IFLA_MASTER */
             + nla_total_size(1) /* IFLA_OPERSTATE */
             + nla_total_size(1) /* IFLA_LINKMODE */
             + rtnl_link_get_size(dev); /* IFLA_LINKINFO */
}

static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
                      int type, u32 pid, u32 seq, u32 change,
                      unsigned int flags)
{
      struct ifinfomsg *ifm;
      struct nlmsghdr *nlh;

      nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
      if (nlh == NULL)
            return -EMSGSIZE;

      ifm = nlmsg_data(nlh);
      ifm->ifi_family = AF_UNSPEC;
      ifm->__ifi_pad = 0;
      ifm->ifi_type = dev->type;
      ifm->ifi_index = dev->ifindex;
      ifm->ifi_flags = dev_get_flags(dev);
      ifm->ifi_change = change;

      NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
      NLA_PUT_U32(skb, IFLA_TXQLEN, dev->tx_queue_len);
      NLA_PUT_U8(skb, IFLA_OPERSTATE,
               netif_running(dev) ? dev->operstate : IF_OPER_DOWN);
      NLA_PUT_U8(skb, IFLA_LINKMODE, dev->link_mode);
      NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);

      if (dev->ifindex != dev->iflink)
            NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);

      if (dev->master)
            NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);

      if (dev->qdisc_sleeping)
            NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc_sleeping->ops->id);

      if (1) {
            struct rtnl_link_ifmap map = {
                  .mem_start   = dev->mem_start,
                  .mem_end     = dev->mem_end,
                  .base_addr   = dev->base_addr,
                  .irq         = dev->irq,
                  .dma         = dev->dma,
                  .port        = dev->if_port,
            };
            NLA_PUT(skb, IFLA_MAP, sizeof(map), &map);
      }

      if (dev->addr_len) {
            NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
            NLA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
      }

      if (dev->get_stats) {
            struct net_device_stats *stats = dev->get_stats(dev);
            if (stats) {
                  struct nlattr *attr;

                  attr = nla_reserve(skb, IFLA_STATS,
                                 sizeof(struct rtnl_link_stats));
                  if (attr == NULL)
                        goto nla_put_failure;

                  copy_rtnl_link_stats(nla_data(attr), stats);
            }
      }

      if (dev->rtnl_link_ops) {
            if (rtnl_link_fill(skb, dev) < 0)
                  goto nla_put_failure;
      }

      return nlmsg_end(skb, nlh);

nla_put_failure:
      nlmsg_cancel(skb, nlh);
      return -EMSGSIZE;
}

static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
{
      struct net *net = skb->sk->sk_net;
      int idx;
      int s_idx = cb->args[0];
      struct net_device *dev;

      idx = 0;
      for_each_netdev(net, dev) {
            if (idx < s_idx)
                  goto cont;
            if (rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
                             NETLINK_CB(cb->skb).pid,
                             cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
                  break;
cont:
            idx++;
      }
      cb->args[0] = idx;

      return skb->len;
}

const struct nla_policy ifla_policy[IFLA_MAX+1] = {
      [IFLA_IFNAME]           = { .type = NLA_STRING, .len = IFNAMSIZ-1 },
      [IFLA_ADDRESS]          = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
      [IFLA_BROADCAST]  = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
      [IFLA_MAP]        = { .len = sizeof(struct rtnl_link_ifmap) },
      [IFLA_MTU]        = { .type = NLA_U32 },
      [IFLA_TXQLEN]           = { .type = NLA_U32 },
      [IFLA_WEIGHT]           = { .type = NLA_U32 },
      [IFLA_OPERSTATE]  = { .type = NLA_U8 },
      [IFLA_LINKMODE]         = { .type = NLA_U8 },
      [IFLA_NET_NS_PID] = { .type = NLA_U32 },
};

static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
      [IFLA_INFO_KIND]  = { .type = NLA_STRING },
      [IFLA_INFO_DATA]  = { .type = NLA_NESTED },
};

static struct net *get_net_ns_by_pid(pid_t pid)
{
      struct task_struct *tsk;
      struct net *net;

      /* Lookup the network namespace */
      net = ERR_PTR(-ESRCH);
      rcu_read_lock();
      tsk = find_task_by_vpid(pid);
      if (tsk) {
            struct nsproxy *nsproxy;
            nsproxy = task_nsproxy(tsk);
            if (nsproxy)
                  net = get_net(nsproxy->net_ns);
      }
      rcu_read_unlock();
      return net;
}

static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
                  struct nlattr **tb, char *ifname, int modified)
{
      int send_addr_notify = 0;
      int err;

      if (tb[IFLA_NET_NS_PID]) {
            struct net *net;
            net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
            if (IS_ERR(net)) {
                  err = PTR_ERR(net);
                  goto errout;
            }
            err = dev_change_net_namespace(dev, net, ifname);
            put_net(net);
            if (err)
                  goto errout;
            modified = 1;
      }

      if (tb[IFLA_MAP]) {
            struct rtnl_link_ifmap *u_map;
            struct ifmap k_map;

            if (!dev->set_config) {
                  err = -EOPNOTSUPP;
                  goto errout;
            }

            if (!netif_device_present(dev)) {
                  err = -ENODEV;
                  goto errout;
            }

            u_map = nla_data(tb[IFLA_MAP]);
            k_map.mem_start = (unsigned long) u_map->mem_start;
            k_map.mem_end = (unsigned long) u_map->mem_end;
            k_map.base_addr = (unsigned short) u_map->base_addr;
            k_map.irq = (unsigned char) u_map->irq;
            k_map.dma = (unsigned char) u_map->dma;
            k_map.port = (unsigned char) u_map->port;

            err = dev->set_config(dev, &k_map);
            if (err < 0)
                  goto errout;

            modified = 1;
      }

      if (tb[IFLA_ADDRESS]) {
            struct sockaddr *sa;
            int len;

            if (!dev->set_mac_address) {
                  err = -EOPNOTSUPP;
                  goto errout;
            }

            if (!netif_device_present(dev)) {
                  err = -ENODEV;
                  goto errout;
            }

            len = sizeof(sa_family_t) + dev->addr_len;
            sa = kmalloc(len, GFP_KERNEL);
            if (!sa) {
                  err = -ENOMEM;
                  goto errout;
            }
            sa->sa_family = dev->type;
            memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]),
                   dev->addr_len);
            err = dev->set_mac_address(dev, sa);
            kfree(sa);
            if (err)
                  goto errout;
            send_addr_notify = 1;
            modified = 1;
      }

      if (tb[IFLA_MTU]) {
            err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
            if (err < 0)
                  goto errout;
            modified = 1;
      }

      /*
       * Interface selected by interface index but interface
       * name provided implies that a name change has been
       * requested.
       */
      if (ifm->ifi_index > 0 && ifname[0]) {
            err = dev_change_name(dev, ifname);
            if (err < 0)
                  goto errout;
            modified = 1;
      }

      if (tb[IFLA_BROADCAST]) {
            nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
            send_addr_notify = 1;
      }

      if (ifm->ifi_flags || ifm->ifi_change) {
            unsigned int flags = ifm->ifi_flags;

            /* bugwards compatibility: ifi_change == 0 is treated as ~0 */
            if (ifm->ifi_change)
                  flags = (flags & ifm->ifi_change) |
                        (dev->flags & ~ifm->ifi_change);
            dev_change_flags(dev, flags);
      }

      if (tb[IFLA_TXQLEN])
            dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);

      if (tb[IFLA_OPERSTATE])
            set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));

      if (tb[IFLA_LINKMODE]) {
            write_lock_bh(&dev_base_lock);
            dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
            write_unlock_bh(&dev_base_lock);
      }

      err = 0;

errout:
      if (err < 0 && modified && net_ratelimit())
            printk(KERN_WARNING "A link change request failed with "
                   "some changes comitted already. Interface %s may "
                   "have been left with an inconsistent configuration, "
                   "please check.\n", dev->name);

      if (send_addr_notify)
            call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
      return err;
}

static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
      struct net *net = skb->sk->sk_net;
      struct ifinfomsg *ifm;
      struct net_device *dev;
      int err;
      struct nlattr *tb[IFLA_MAX+1];
      char ifname[IFNAMSIZ];

      err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
      if (err < 0)
            goto errout;

      if (tb[IFLA_IFNAME])
            nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
      else
            ifname[0] = '\0';

      err = -EINVAL;
      ifm = nlmsg_data(nlh);
      if (ifm->ifi_index > 0)
            dev = dev_get_by_index(net, ifm->ifi_index);
      else if (tb[IFLA_IFNAME])
            dev = dev_get_by_name(net, ifname);
      else
            goto errout;

      if (dev == NULL) {
            err = -ENODEV;
            goto errout;
      }

      if (tb[IFLA_ADDRESS] &&
          nla_len(tb[IFLA_ADDRESS]) < dev->addr_len)
            goto errout_dev;

      if (tb[IFLA_BROADCAST] &&
          nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
            goto errout_dev;

      err = do_setlink(dev, ifm, tb, ifname, 0);
errout_dev:
      dev_put(dev);
errout:
      return err;
}

static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
      struct net *net = skb->sk->sk_net;
      const struct rtnl_link_ops *ops;
      struct net_device *dev;
      struct ifinfomsg *ifm;
      char ifname[IFNAMSIZ];
      struct nlattr *tb[IFLA_MAX+1];
      int err;

      err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
      if (err < 0)
            return err;

      if (tb[IFLA_IFNAME])
            nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);

      ifm = nlmsg_data(nlh);
      if (ifm->ifi_index > 0)
            dev = __dev_get_by_index(net, ifm->ifi_index);
      else if (tb[IFLA_IFNAME])
            dev = __dev_get_by_name(net, ifname);
      else
            return -EINVAL;

      if (!dev)
            return -ENODEV;

      ops = dev->rtnl_link_ops;
      if (!ops)
            return -EOPNOTSUPP;

      ops->dellink(dev);
      return 0;
}

struct net_device *rtnl_create_link(struct net *net, char *ifname,
            const struct rtnl_link_ops *ops, struct nlattr *tb[])
{
      int err;
      struct net_device *dev;

      err = -ENOMEM;
      dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
      if (!dev)
            goto err;

      if (strchr(dev->name, '%')) {
            err = dev_alloc_name(dev, dev->name);
            if (err < 0)
                  goto err_free;
      }

      dev->nd_net = net;
      dev->rtnl_link_ops = ops;

      if (tb[IFLA_MTU])
            dev->mtu = nla_get_u32(tb[IFLA_MTU]);
      if (tb[IFLA_ADDRESS])
            memcpy(dev->dev_addr, nla_data(tb[IFLA_ADDRESS]),
                        nla_len(tb[IFLA_ADDRESS]));
      if (tb[IFLA_BROADCAST])
            memcpy(dev->broadcast, nla_data(tb[IFLA_BROADCAST]),
                        nla_len(tb[IFLA_BROADCAST]));
      if (tb[IFLA_TXQLEN])
            dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
      if (tb[IFLA_OPERSTATE])
            set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
      if (tb[IFLA_LINKMODE])
            dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);

      return dev;

err_free:
      free_netdev(dev);
err:
      return ERR_PTR(err);
}

static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
      struct net *net = skb->sk->sk_net;
      const struct rtnl_link_ops *ops;
      struct net_device *dev;
      struct ifinfomsg *ifm;
      char kind[MODULE_NAME_LEN];
      char ifname[IFNAMSIZ];
      struct nlattr *tb[IFLA_MAX+1];
      struct nlattr *linkinfo[IFLA_INFO_MAX+1];
      int err;

#ifdef CONFIG_KMOD
replay:
#endif
      err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
      if (err < 0)
            return err;

      if (tb[IFLA_IFNAME])
            nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
      else
            ifname[0] = '\0';

      ifm = nlmsg_data(nlh);
      if (ifm->ifi_index > 0)
            dev = __dev_get_by_index(net, ifm->ifi_index);
      else if (ifname[0])
            dev = __dev_get_by_name(net, ifname);
      else
            dev = NULL;

      if (tb[IFLA_LINKINFO]) {
            err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
                               tb[IFLA_LINKINFO], ifla_info_policy);
            if (err < 0)
                  return err;
      } else
            memset(linkinfo, 0, sizeof(linkinfo));

      if (linkinfo[IFLA_INFO_KIND]) {
            nla_strlcpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
            ops = rtnl_link_ops_get(kind);
      } else {
            kind[0] = '\0';
            ops = NULL;
      }

      if (1) {
            struct nlattr *attr[ops ? ops->maxtype + 1 : 0], **data = NULL;

            if (ops) {
                  if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
                        err = nla_parse_nested(attr, ops->maxtype,
                                           linkinfo[IFLA_INFO_DATA],
                                           ops->policy);
                        if (err < 0)
                              return err;
                        data = attr;
                  }
                  if (ops->validate) {
                        err = ops->validate(tb, data);
                        if (err < 0)
                              return err;
                  }
            }

            if (dev) {
                  int modified = 0;

                  if (nlh->nlmsg_flags & NLM_F_EXCL)
                        return -EEXIST;
                  if (nlh->nlmsg_flags & NLM_F_REPLACE)
                        return -EOPNOTSUPP;

                  if (linkinfo[IFLA_INFO_DATA]) {
                        if (!ops || ops != dev->rtnl_link_ops ||
                            !ops->changelink)
                              return -EOPNOTSUPP;

                        err = ops->changelink(dev, tb, data);
                        if (err < 0)
                              return err;
                        modified = 1;
                  }

                  return do_setlink(dev, ifm, tb, ifname, modified);
            }

            if (!(nlh->nlmsg_flags & NLM_F_CREATE))
                  return -ENODEV;

            if (ifm->ifi_index || ifm->ifi_flags || ifm->ifi_change)
                  return -EOPNOTSUPP;
            if (tb[IFLA_MAP] || tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
                  return -EOPNOTSUPP;

            if (!ops) {
#ifdef CONFIG_KMOD
                  if (kind[0]) {
                        __rtnl_unlock();
                        request_module("rtnl-link-%s", kind);
                        rtnl_lock();
                        ops = rtnl_link_ops_get(kind);
                        if (ops)
                              goto replay;
                  }
#endif
                  return -EOPNOTSUPP;
            }

            if (!ifname[0])
                  snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);

            dev = rtnl_create_link(net, ifname, ops, tb);

            if (IS_ERR(dev))
                  err = PTR_ERR(dev);
            else if (ops->newlink)
                  err = ops->newlink(dev, tb, data);
            else
                  err = register_netdevice(dev);

            if (err < 0 && !IS_ERR(dev))
                  free_netdev(dev);
            return err;
      }
}

static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
      struct net *net = skb->sk->sk_net;
      struct ifinfomsg *ifm;
      struct nlattr *tb[IFLA_MAX+1];
      struct net_device *dev = NULL;
      struct sk_buff *nskb;
      int err;

      err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
      if (err < 0)
            return err;

      ifm = nlmsg_data(nlh);
      if (ifm->ifi_index > 0) {
            dev = dev_get_by_index(net, ifm->ifi_index);
            if (dev == NULL)
                  return -ENODEV;
      } else
            return -EINVAL;

      nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
      if (nskb == NULL) {
            err = -ENOBUFS;
            goto errout;
      }

      err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid,
                         nlh->nlmsg_seq, 0, 0);
      if (err < 0) {
            /* -EMSGSIZE implies BUG in if_nlmsg_size */
            WARN_ON(err == -EMSGSIZE);
            kfree_skb(nskb);
            goto errout;
      }
      err = rtnl_unicast(nskb, NETLINK_CB(skb).pid);
errout:
      dev_put(dev);

      return err;
}

static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
{
      int idx;
      int s_idx = cb->family;

      if (s_idx == 0)
            s_idx = 1;
      for (idx=1; idx<NPROTO; idx++) {
            int type = cb->nlh->nlmsg_type-RTM_BASE;
            if (idx < s_idx || idx == PF_PACKET)
                  continue;
            if (rtnl_msg_handlers[idx] == NULL ||
                rtnl_msg_handlers[idx][type].dumpit == NULL)
                  continue;
            if (idx > s_idx)
                  memset(&cb->args[0], 0, sizeof(cb->args));
            if (rtnl_msg_handlers[idx][type].dumpit(skb, cb))
                  break;
      }
      cb->family = idx;

      return skb->len;
}

void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
{
      struct sk_buff *skb;
      int err = -ENOBUFS;

      skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
      if (skb == NULL)
            goto errout;

      err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0);
      if (err < 0) {
            /* -EMSGSIZE implies BUG in if_nlmsg_size() */
            WARN_ON(err == -EMSGSIZE);
            kfree_skb(skb);
            goto errout;
      }
      err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
errout:
      if (err < 0)
            rtnl_set_sk_err(RTNLGRP_LINK, err);
}

/* Protected by RTNL sempahore.  */
static struct rtattr **rta_buf;
static int rtattr_max;

/* Process one rtnetlink message. */

static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
      rtnl_doit_func doit;
      int sz_idx, kind;
      int min_len;
      int family;
      int type;
      int err;

      type = nlh->nlmsg_type;
      if (type > RTM_MAX)
            return -EOPNOTSUPP;

      type -= RTM_BASE;

      /* All the messages must have at least 1 byte length */
      if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
            return 0;

      family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
      if (family >= NPROTO)
            return -EAFNOSUPPORT;

      sz_idx = type>>2;
      kind = type&3;

      if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
            return -EPERM;

      if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
            rtnl_dumpit_func dumpit;

            dumpit = rtnl_get_dumpit(family, type);
            if (dumpit == NULL)
                  return -EOPNOTSUPP;

            __rtnl_unlock();
            err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
            rtnl_lock();
            return err;
      }

      memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));

      min_len = rtm_min[sz_idx];
      if (nlh->nlmsg_len < min_len)
            return -EINVAL;

      if (nlh->nlmsg_len > min_len) {
            int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
            struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);

            while (RTA_OK(attr, attrlen)) {
                  unsigned flavor = attr->rta_type;
                  if (flavor) {
                        if (flavor > rta_max[sz_idx])
                              return -EINVAL;
                        rta_buf[flavor-1] = attr;
                  }
                  attr = RTA_NEXT(attr, attrlen);
            }
      }

      doit = rtnl_get_doit(family, type);
      if (doit == NULL)
            return -EOPNOTSUPP;

      return doit(skb, nlh, (void *)&rta_buf[0]);
}

static void rtnetlink_rcv(struct sk_buff *skb)
{
      rtnl_lock();
      netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
      rtnl_unlock();
}

static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
{
      struct net_device *dev = ptr;

      if (dev->nd_net != &init_net)
            return NOTIFY_DONE;

      switch (event) {
      case NETDEV_UNREGISTER:
            rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
            break;
      case NETDEV_REGISTER:
            rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
            break;
      case NETDEV_UP:
      case NETDEV_DOWN:
            rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
            break;
      case NETDEV_CHANGE:
      case NETDEV_GOING_DOWN:
            break;
      default:
            rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
            break;
      }
      return NOTIFY_DONE;
}

static struct notifier_block rtnetlink_dev_notifier = {
      .notifier_call    = rtnetlink_event,
};

void __init rtnetlink_init(void)
{
      int i;

      rtattr_max = 0;
      for (i = 0; i < ARRAY_SIZE(rta_max); i++)
            if (rta_max[i] > rtattr_max)
                  rtattr_max = rta_max[i];
      rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
      if (!rta_buf)
            panic("rtnetlink_init: cannot allocate rta_buf\n");

      rtnl = netlink_kernel_create(&init_net, NETLINK_ROUTE, RTNLGRP_MAX,
                             rtnetlink_rcv, &rtnl_mutex, THIS_MODULE);
      if (rtnl == NULL)
            panic("rtnetlink_init: cannot initialize rtnetlink\n");
      netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
      register_netdevice_notifier(&rtnetlink_dev_notifier);

      rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
      rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
      rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
      rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);

      rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
      rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
}

EXPORT_SYMBOL(__rta_fill);
EXPORT_SYMBOL(rtattr_strlcpy);
EXPORT_SYMBOL(rtattr_parse);
EXPORT_SYMBOL(__rtattr_parse_nested_compat);
EXPORT_SYMBOL(rtnetlink_put_metrics);
EXPORT_SYMBOL(rtnl_lock);
EXPORT_SYMBOL(rtnl_trylock);
EXPORT_SYMBOL(rtnl_unlock);
EXPORT_SYMBOL(rtnl_unicast);
EXPORT_SYMBOL(rtnl_notify);
EXPORT_SYMBOL(rtnl_set_sk_err);
EXPORT_SYMBOL(rtnl_create_link);
EXPORT_SYMBOL(ifla_policy);

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