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link.c

/*
 * lib/route/link.c     Links (Interfaces)
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation version 2.1
 *    of the License.
 *
 * Copyright (c) 2003-2006 Thomas Graf <tgraf@suug.ch>
 */

/**
 * @ingroup rtnl
 * @defgroup link Links (Interfaces)
 * @brief
 *
 * @par Link Identification
 * A link can be identified by either its interface index or by its
 * name. The kernel favours the interface index but falls back to the
 * interface name if the interface index is lesser-than 0 for kernels
 * >= 2.6.11. Therefore you can request changes without mapping a
 * interface name to the corresponding index first.
 *
 * @par Changeable Attributes
 * @anchor link_changeable
 *  - Link layer address
 *  - Link layer broadcast address
 *  - device mapping (ifmap) (>= 2.6.9)
 *  - MTU (>= 2.6.9)
 *  - Transmission queue length (>= 2.6.9)
 *  - Weight (>= 2.6.9)
 *  - Link name (only via access through interface index) (>= 2.6.9)
 *  - Flags (>= 2.6.9)
 *    - IFF_DEBUG
 *    - IFF_NOTRAILERS
 *    - IFF_NOARP
 *    - IFF_DYNAMIC
 *    - IFF_MULTICAST
 *    - IFF_PORTSEL
 *    - IFF_AUTOMEDIA
 *    - IFF_UP
 *    - IFF_PROMISC
 *    - IFF_ALLMULTI
 *
 * @par Link Flags (linux/if.h)
 * @anchor link_flags
 * @code
 *   IFF_UP            Status of link (up|down)
 *   IFF_BROADCAST     Indicates this link allows broadcasting
 *   IFF_MULTICAST     Indicates this link allows multicasting
 *   IFF_ALLMULTI      Indicates this link is doing multicast routing
 *   IFF_DEBUG         Tell the driver to do debugging (currently unused)
 *   IFF_LOOPBACK      This is the loopback link
 *   IFF_POINTOPOINT   Point-to-point link
 *   IFF_NOARP         Link is unable to perform ARP
 *   IFF_PROMISC       Status of promiscious mode flag
 *   IFF_MASTER        Used by teql
 *   IFF_SLAVE         Used by teql
 *   IFF_PORTSEL       Indicates this link allows port selection
 *   IFF_AUTOMEDIA     Indicates this link selects port automatically
 *   IFF_DYNAMIC       Indicates the address of this link is dynamic
 *   IFF_RUNNING       Link is running and carrier is ok.
 *   IFF_NOTRAILERS    Unused, BSD compat.
 * @endcode
 *
 * @par Notes on IFF_PROMISC and IFF_ALLMULTI flags
 * Although you can query the status of IFF_PROMISC and IFF_ALLMULTI
 * they do not represent the actual state in the kernel but rather
 * whether the flag has been enabled/disabled by userspace. The link
 * may be in promiscious mode even if IFF_PROMISC is not set in a link
 * dump request response because promiscity might be needed by the driver
 * for a period of time.
 *
 * @note The unit of the transmission queue length depends on the
 *       link type, a common unit is \a packets.
 *
 * @par 1) Retrieving information about available links
 * @code
 * // The first step is to retrieve a list of all available interfaces within
 * // the kernel and put them into a cache.
 * struct nl_cache *cache = rtnl_link_alloc_cache(nl_handle);
 *
 * // In a second step, a specific link may be looked up by either interface
 * // index or interface name.
 * struct rtnl_link *link = rtnl_link_get_by_name(cache, "lo");
 *
 * // rtnl_link_get_by_name() is the short version for translating the
 * // interface name to an interface index first like this:
 * int ifindex = rtnl_link_name2i(cache, "lo");
 * struct rtnl_link *link = rtnl_link_get(cache, ifindex);
 *
 * // After successful usage, the object must be given back to the cache
 * rtnl_link_put(link);
 * @endcode
 *
 * @par 2) Changing link attributes
 * @code
 * // In order to change any attributes of an existing link, we must allocate
 * // a new link to hold the change requests:
 * struct rtnl_link *request = rtnl_link_alloc();
 *
 * // Now we can go on and specify the attributes we want to change:
 * rtnl_link_set_weight(request, 300);
 * rtnl_link_set_mtu(request, 1360);
 *
 * // We can also shut an interface down administratively
 * rtnl_link_unset_flags(request, rtnl_link_str2flags("up"));
 *
 * // Actually, we should know which link to change, so let's look it up
 * struct rtnl_link *old = rtnl_link_get(cache, "eth0");
 *
 * // Two ways exist to commit this change request, the first one is to
 * // build the required netlink message and send it out in one single
 * // step:
 * rtnl_link_change(nl_handle, old, request);
 *
 * // An alternative way is to build the netlink message and send it
 * // out yourself using nl_send_auto_complete()
 * struct nl_msg *msg = rtnl_link_build_change_request(old, request);
 * nl_send_auto_complete(nl_handle, nlmsg_hdr(msg));
 * nlmsg_free(msg);
 *
 * // Don't forget to give back the link object ;->
 * rtnl_link_put(old);
 * @endcode
 *
 * @par 3) Link Type Specific Attributes
 * @code
 * // Some link types offer additional parameters and statistics specific
 * // to their type. F.e. a VLAN link can be configured like this:
 * //
 * // Allocate a new link and set the info type to "vlan". This is required
 * // to prepare the link to hold vlan specific attributes.
 * struct rtnl_link *request = rtnl_link_alloc();
 * rtnl_link_set_info_type(request, "vlan");
 *
 * // Now vlan specific attributes can be set:
 * rtnl_link_vlan_set_id(request, 10);
 * rtnl_link_vlan_set_ingress_map(request, 2, 8);
 *
 * // Of course the attributes can also be read, check the info type
 * // to make sure you are using the right access functions:
 * char *type = rtnl_link_get_info_type(link);
 * if (!strcmp(type, "vlan"))
 *    int id = rtnl_link_vlan_get_id(link);
 * @endcode
 * @{
 */

#include <netlink-local.h>
#include <netlink/netlink.h>
#include <netlink/attr.h>
#include <netlink/utils.h>
#include <netlink/object.h>
#include <netlink/route/rtnl.h>
#include <netlink/route/link.h>
#include <netlink/route/link/info-api.h>

/** @cond SKIP */
#define LINK_ATTR_MTU     0x0001
#define LINK_ATTR_LINK    0x0002
#define LINK_ATTR_TXQLEN  0x0004
#define LINK_ATTR_WEIGHT  0x0008
#define LINK_ATTR_MASTER  0x0010
#define LINK_ATTR_QDISC   0x0020
#define LINK_ATTR_MAP     0x0040
#define LINK_ATTR_ADDR    0x0080
#define LINK_ATTR_BRD     0x0100
#define LINK_ATTR_FLAGS   0x0200
#define LINK_ATTR_IFNAME  0x0400
#define LINK_ATTR_IFINDEX 0x0800
#define LINK_ATTR_FAMILY  0x1000
#define LINK_ATTR_ARPTYPE 0x2000
#define LINK_ATTR_STATS   0x4000
#define LINK_ATTR_CHANGE  0x8000
#define LINK_ATTR_OPERSTATE 0x10000
#define LINK_ATTR_LINKMODE  0x20000
#define LINK_ATTR_LINKINFO  0x40000

static struct nl_cache_ops rtnl_link_ops;
static struct nl_object_ops link_obj_ops;
/** @endcond */

00184 static void release_link_info(struct rtnl_link *link)
{
      struct rtnl_link_info_ops *io = link->l_info_ops;

      if (io != NULL) {
            io->io_refcnt--;
            io->io_free(link);
            link->l_info_ops = NULL;
      }
}

static void link_free_data(struct nl_object *c)
{
      struct rtnl_link *link = nl_object_priv(c);

      if (link) {
            struct rtnl_link_info_ops *io;

            if ((io = link->l_info_ops) != NULL)
                  release_link_info(link);

            nl_addr_put(link->l_addr);
            nl_addr_put(link->l_bcast);
      }
}

static int link_clone(struct nl_object *_dst, struct nl_object *_src)
{
      struct rtnl_link *dst = nl_object_priv(_dst);
      struct rtnl_link *src = nl_object_priv(_src);
      int err;

      if (src->l_addr)
            if (!(dst->l_addr = nl_addr_clone(src->l_addr)))
                  goto errout;

      if (src->l_bcast)
            if (!(dst->l_bcast = nl_addr_clone(src->l_bcast)))
                  goto errout;

      if (src->l_info_ops && src->l_info_ops->io_clone) {
            err = src->l_info_ops->io_clone(dst, src);
            if (err < 0)
                  goto errout;
      }

      return 0;
errout:
      return nl_get_errno();
}

static struct nla_policy link_policy[IFLA_MAX+1] = {
      [IFLA_IFNAME]     = { .type = NLA_STRING,
                      .maxlen = IFNAMSIZ },
      [IFLA_MTU]  = { .type = NLA_U32 },
      [IFLA_TXQLEN]     = { .type = NLA_U32 },
      [IFLA_LINK] = { .type = NLA_U32 },
      [IFLA_WEIGHT]     = { .type = NLA_U32 },
      [IFLA_MASTER]     = { .type = NLA_U32 },
      [IFLA_OPERSTATE]= { .type = NLA_U8 },
      [IFLA_LINKMODE] = { .type = NLA_U8 },
      [IFLA_LINKINFO]   = { .type = NLA_NESTED },
      [IFLA_QDISC]      = { .type = NLA_STRING,
                      .maxlen = IFQDISCSIZ },
      [IFLA_STATS]      = { .minlen = sizeof(struct rtnl_link_stats) },
      [IFLA_MAP]  = { .minlen = sizeof(struct rtnl_link_ifmap) },
};

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

static int link_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
                     struct nlmsghdr *n, struct nl_parser_param *pp)
{
      struct rtnl_link *link;
      struct ifinfomsg *ifi;
      struct nlattr *tb[IFLA_MAX+1];
      int err;

      link = rtnl_link_alloc();
      if (link == NULL) {
            err = nl_errno(ENOMEM);
            goto errout;
      }
            
      link->ce_msgtype = n->nlmsg_type;

      err = nlmsg_parse(n, sizeof(*ifi), tb, IFLA_MAX, link_policy);
      if (err < 0)
            goto errout;

      if (tb[IFLA_IFNAME] == NULL) {
            err = nl_error(EINVAL, "Missing link name TLV");
            goto errout;
      }

      nla_strlcpy(link->l_name, tb[IFLA_IFNAME], IFNAMSIZ);

      ifi = nlmsg_data(n);
      link->l_family = ifi->ifi_family;
      link->l_arptype = ifi->ifi_type;
      link->l_index = ifi->ifi_index;
      link->l_flags = ifi->ifi_flags;
      link->l_change = ifi->ifi_change;
      link->ce_mask = (LINK_ATTR_IFNAME | LINK_ATTR_FAMILY |
                    LINK_ATTR_ARPTYPE| LINK_ATTR_IFINDEX |
                    LINK_ATTR_FLAGS | LINK_ATTR_CHANGE);

      if (tb[IFLA_STATS]) {
            struct rtnl_link_stats *st = nla_data(tb[IFLA_STATS]);
            
            link->l_stats[RTNL_LINK_RX_PACKETS] = st->rx_packets;
            link->l_stats[RTNL_LINK_RX_BYTES]   = st->rx_bytes;
            link->l_stats[RTNL_LINK_RX_ERRORS]  = st->rx_errors;
            link->l_stats[RTNL_LINK_RX_DROPPED] = st->rx_dropped;
            link->l_stats[RTNL_LINK_RX_COMPRESSED]    = st->rx_compressed;
            link->l_stats[RTNL_LINK_RX_FIFO_ERR]      = st->rx_fifo_errors;
            link->l_stats[RTNL_LINK_TX_PACKETS] = st->tx_packets;
            link->l_stats[RTNL_LINK_TX_BYTES]   = st->tx_bytes;
            link->l_stats[RTNL_LINK_TX_ERRORS]  = st->tx_errors;
            link->l_stats[RTNL_LINK_TX_DROPPED] = st->tx_dropped;
            link->l_stats[RTNL_LINK_TX_COMPRESSED]    = st->tx_compressed;
            link->l_stats[RTNL_LINK_TX_FIFO_ERR]      = st->tx_fifo_errors;
            link->l_stats[RTNL_LINK_RX_LEN_ERR] = st->rx_length_errors;
            link->l_stats[RTNL_LINK_RX_OVER_ERR]      = st->rx_over_errors;
            link->l_stats[RTNL_LINK_RX_CRC_ERR] = st->rx_crc_errors;
            link->l_stats[RTNL_LINK_RX_FRAME_ERR]     = st->rx_frame_errors;
            link->l_stats[RTNL_LINK_RX_MISSED_ERR]    = st->rx_missed_errors;
            link->l_stats[RTNL_LINK_TX_ABORT_ERR]     = st->tx_aborted_errors;
            link->l_stats[RTNL_LINK_TX_CARRIER_ERR]   = st->tx_carrier_errors;
            link->l_stats[RTNL_LINK_TX_HBEAT_ERR]     = st->tx_heartbeat_errors;
            link->l_stats[RTNL_LINK_TX_WIN_ERR] = st->tx_window_errors;
            link->l_stats[RTNL_LINK_MULTICAST]  = st->multicast;

            link->ce_mask |= LINK_ATTR_STATS;
      }

      if (tb[IFLA_TXQLEN]) {
            link->l_txqlen = nla_get_u32(tb[IFLA_TXQLEN]);
            link->ce_mask |= LINK_ATTR_TXQLEN;
      }

      if (tb[IFLA_MTU]) {
            link->l_mtu = nla_get_u32(tb[IFLA_MTU]);
            link->ce_mask |= LINK_ATTR_MTU;
      }

      if (tb[IFLA_ADDRESS]) {
            link->l_addr = nla_get_addr(tb[IFLA_ADDRESS], AF_UNSPEC);
            if (link->l_addr == NULL)
                  goto errout;
            nl_addr_set_family(link->l_addr,
                           nl_addr_guess_family(link->l_addr));
            link->ce_mask |= LINK_ATTR_ADDR;
      }

      if (tb[IFLA_BROADCAST]) {
            link->l_bcast = nla_get_addr(tb[IFLA_BROADCAST], AF_UNSPEC);
            if (link->l_bcast == NULL)
                  goto errout;
            nl_addr_set_family(link->l_bcast,
                           nl_addr_guess_family(link->l_bcast));
            link->ce_mask |= LINK_ATTR_BRD;
      }

      if (tb[IFLA_LINK]) {
            link->l_link = nla_get_u32(tb[IFLA_LINK]);
            link->ce_mask |= LINK_ATTR_LINK;
      }

      if (tb[IFLA_WEIGHT]) {
            link->l_weight = nla_get_u32(tb[IFLA_WEIGHT]);
            link->ce_mask |= LINK_ATTR_WEIGHT;
      }

      if (tb[IFLA_QDISC]) {
            nla_strlcpy(link->l_qdisc, tb[IFLA_QDISC], IFQDISCSIZ);
            link->ce_mask |= LINK_ATTR_QDISC;
      }

      if (tb[IFLA_MAP]) {
            struct rtnl_link_ifmap *map =  nla_data(tb[IFLA_MAP]);
            link->l_map.lm_mem_start = map->mem_start;
            link->l_map.lm_mem_end   = map->mem_end;
            link->l_map.lm_base_addr = map->base_addr;
            link->l_map.lm_irq       = map->irq;
            link->l_map.lm_dma       = map->dma;
            link->l_map.lm_port      = map->port;
            link->ce_mask |= LINK_ATTR_MAP;
      }

      if (tb[IFLA_MASTER]) {
            link->l_master = nla_get_u32(tb[IFLA_MASTER]);
            link->ce_mask |= LINK_ATTR_MASTER;
      }

      if (tb[IFLA_OPERSTATE]) {
            link->l_operstate = nla_get_u8(tb[IFLA_OPERSTATE]);
            link->ce_mask |= LINK_ATTR_OPERSTATE;
      }

      if (tb[IFLA_LINKMODE]) {
            link->l_linkmode = nla_get_u8(tb[IFLA_LINKMODE]);
            link->ce_mask |= LINK_ATTR_LINKMODE;
      }

      if (tb[IFLA_LINKINFO]) {
            struct nlattr *li[IFLA_INFO_MAX+1];

            err = nla_parse_nested(li, IFLA_INFO_MAX, tb[IFLA_LINKINFO],
                               link_info_policy);
            if (err < 0)
                  goto errout;

            if (li[IFLA_INFO_KIND] &&
                (li[IFLA_INFO_DATA] || li[IFLA_INFO_XSTATS])) {
                  struct rtnl_link_info_ops *ops;
                  char *kind;

                  kind = nla_get_string(li[IFLA_INFO_KIND]);
                  ops = rtnl_link_info_ops_lookup(kind);
                  if (ops != NULL) {
                        ops->io_refcnt++;
                        link->l_info_ops = ops;
                        err = ops->io_parse(link, li[IFLA_INFO_DATA],
                                        li[IFLA_INFO_XSTATS]);
                        if (err < 0)
                              goto errout;
                  } else {
                        /* XXX: Warn about unparsed info? */
                  }
            }
      }

      err = pp->pp_cb((struct nl_object *) link, pp);
      if (err < 0)
            goto errout;

      err = P_ACCEPT;

errout:
      rtnl_link_put(link);
      return err;
}

static int link_request_update(struct nl_cache *c, struct nl_handle *h)
{
      return nl_rtgen_request(h, RTM_GETLINK, AF_UNSPEC, NLM_F_DUMP);
}

static int link_dump_brief(struct nl_object *obj, struct nl_dump_params *p)
{
      char buf[128];
      struct nl_cache *cache = dp_cache(obj);
      struct rtnl_link *link = (struct rtnl_link *) obj;
      int line = 1;

      dp_dump(p, "%s %s ", link->l_name,
                       nl_llproto2str(link->l_arptype, buf, sizeof(buf)));

      if (link->l_addr && !nl_addr_iszero(link->l_addr))
            dp_dump(p, "%s ", nl_addr2str(link->l_addr, buf, sizeof(buf)));

      if (link->ce_mask & LINK_ATTR_MASTER) {
            struct rtnl_link *master = rtnl_link_get(cache, link->l_master);
            dp_dump(p, "master %s ", master ? master->l_name : "inv");
            if (master)
                  rtnl_link_put(master);
      }

      rtnl_link_flags2str(link->l_flags, buf, sizeof(buf));
      if (buf[0])
            dp_dump(p, "<%s> ", buf);

      if (link->ce_mask & LINK_ATTR_LINK) {
            struct rtnl_link *ll = rtnl_link_get(cache, link->l_link);
            dp_dump(p, "slave-of %s ", ll ? ll->l_name : "NONE");
            if (ll)
                  rtnl_link_put(ll);
      }

      if (link->l_info_ops && link->l_info_ops->io_dump[NL_DUMP_BRIEF])
            line = link->l_info_ops->io_dump[NL_DUMP_BRIEF](link, p, line);

      dp_dump(p, "\n");

      return line;
}

static int link_dump_full(struct nl_object *obj, struct nl_dump_params *p)
{
      struct rtnl_link *link = (struct rtnl_link *) obj;
      char buf[64];
      int line;

      line = link_dump_brief(obj, p);
      dp_new_line(p, line++);

      dp_dump(p, "    mtu %u ", link->l_mtu);
      dp_dump(p, "txqlen %u weight %u ", link->l_txqlen, link->l_weight);

      if (link->ce_mask & LINK_ATTR_QDISC)
            dp_dump(p, "qdisc %s ", link->l_qdisc);

      if (link->ce_mask & LINK_ATTR_MAP && link->l_map.lm_irq)
            dp_dump(p, "irq %u ", link->l_map.lm_irq);

      if (link->ce_mask & LINK_ATTR_IFINDEX)
            dp_dump(p, "index %u ", link->l_index);


      dp_dump(p, "\n");
      dp_new_line(p, line++);

      dp_dump(p, "    ");

      if (link->ce_mask & LINK_ATTR_BRD)
            dp_dump(p, "brd %s ", nl_addr2str(link->l_bcast, buf,
                                       sizeof(buf)));

      if ((link->ce_mask & LINK_ATTR_OPERSTATE) &&
          link->l_operstate != IF_OPER_UNKNOWN) {
            rtnl_link_operstate2str(link->l_operstate, buf, sizeof(buf));
            dp_dump(p, "state %s ", buf);
      }

      dp_dump(p, "mode %s\n",
            rtnl_link_mode2str(link->l_linkmode, buf, sizeof(buf)));

      if (link->l_info_ops && link->l_info_ops->io_dump[NL_DUMP_FULL])
            line = link->l_info_ops->io_dump[NL_DUMP_FULL](link, p, line);

      return line;
}

static int link_dump_stats(struct nl_object *obj, struct nl_dump_params *p)
{
      struct rtnl_link *link = (struct rtnl_link *) obj;
      char *unit, fmt[64];
      float res;
      int line;
      
      line = link_dump_full(obj, p);

      dp_dump_line(p, line++, "    Stats:    bytes    packets     errors "
                        "   dropped   fifo-err compressed\n");

      res = nl_cancel_down_bytes(link->l_stats[RTNL_LINK_RX_BYTES], &unit);

      strcpy(fmt, "    RX  %X.2f %s %10llu %10llu %10llu %10llu %10llu\n");
      fmt[9] = *unit == 'B' ? '9' : '7';
      
      dp_dump_line(p, line++, fmt,
            res, unit,
            link->l_stats[RTNL_LINK_RX_PACKETS],
            link->l_stats[RTNL_LINK_RX_ERRORS],
            link->l_stats[RTNL_LINK_RX_DROPPED],
            link->l_stats[RTNL_LINK_RX_FIFO_ERR],
            link->l_stats[RTNL_LINK_RX_COMPRESSED]);

      res = nl_cancel_down_bytes(link->l_stats[RTNL_LINK_TX_BYTES], &unit);

      strcpy(fmt, "    TX  %X.2f %s %10llu %10llu %10llu %10llu %10llu\n");
      fmt[9] = *unit == 'B' ? '9' : '7';
      
      dp_dump_line(p, line++, fmt,
            res, unit,
            link->l_stats[RTNL_LINK_TX_PACKETS],
            link->l_stats[RTNL_LINK_TX_ERRORS],
            link->l_stats[RTNL_LINK_TX_DROPPED],
            link->l_stats[RTNL_LINK_TX_FIFO_ERR],
            link->l_stats[RTNL_LINK_TX_COMPRESSED]);

      dp_dump_line(p, line++, "    Errors:  length       over        crc "
                        "     frame     missed  multicast\n");

      dp_dump_line(p, line++, "    RX   %10" PRIu64 " %10" PRIu64 " %10"
                        PRIu64 " %10" PRIu64 " %10" PRIu64 " %10"
                        PRIu64 "\n",
            link->l_stats[RTNL_LINK_RX_LEN_ERR],
            link->l_stats[RTNL_LINK_RX_OVER_ERR],
            link->l_stats[RTNL_LINK_RX_CRC_ERR],
            link->l_stats[RTNL_LINK_RX_FRAME_ERR],
            link->l_stats[RTNL_LINK_RX_MISSED_ERR],
            link->l_stats[RTNL_LINK_MULTICAST]);

      dp_dump_line(p, line++, "    Errors: aborted    carrier  heartbeat "
                        "    window  collision\n");
      
      dp_dump_line(p, line++, "    TX   %10" PRIu64 " %10" PRIu64 " %10"
                        PRIu64 " %10" PRIu64 " %10" PRIu64 "\n",
            link->l_stats[RTNL_LINK_TX_ABORT_ERR],
            link->l_stats[RTNL_LINK_TX_CARRIER_ERR],
            link->l_stats[RTNL_LINK_TX_HBEAT_ERR],
            link->l_stats[RTNL_LINK_TX_WIN_ERR],
            link->l_stats[RTNL_LINK_TX_COLLISIONS]);

      if (link->l_info_ops && link->l_info_ops->io_dump[NL_DUMP_STATS])
            line = link->l_info_ops->io_dump[NL_DUMP_STATS](link, p, line);

      return line;
}

static int link_dump_xml(struct nl_object *obj, struct nl_dump_params *p)
{
      struct rtnl_link *link = (struct rtnl_link *) obj;
      struct nl_cache *cache = dp_cache(obj);
      char buf[128];
      int i, line = 0;

      dp_dump_line(p, line++, "<link name=\"%s\" index=\"%u\">\n",
                 link->l_name, link->l_index);
      dp_dump_line(p, line++, "  <family>%s</family>\n",
                 nl_af2str(link->l_family, buf, sizeof(buf)));
      dp_dump_line(p, line++, "  <arptype>%s</arptype>\n",
                 nl_llproto2str(link->l_arptype, buf, sizeof(buf)));
      dp_dump_line(p, line++, "  <address>%s</address>\n",
                 nl_addr2str(link->l_addr, buf, sizeof(buf)));
      dp_dump_line(p, line++, "  <mtu>%u</mtu>\n", link->l_mtu);
      dp_dump_line(p, line++, "  <txqlen>%u</txqlen>\n", link->l_txqlen);
      dp_dump_line(p, line++, "  <weight>%u</weight>\n", link->l_weight);

      rtnl_link_flags2str(link->l_flags, buf, sizeof(buf));
      if (buf[0])
            dp_dump_line(p, line++, "  <flags>%s</flags>\n", buf);

      if (link->ce_mask & LINK_ATTR_QDISC)
            dp_dump_line(p, line++, "  <qdisc>%s</qdisc>\n", link->l_qdisc);

      if (link->ce_mask & LINK_ATTR_LINK) {
            struct rtnl_link *ll = rtnl_link_get(cache, link->l_link);
            dp_dump_line(p, line++, "  <link>%s</link>\n",
                       ll ? ll->l_name : "none");
            if (ll)
                  rtnl_link_put(ll);
      }

      if (link->ce_mask & LINK_ATTR_MASTER) {
            struct rtnl_link *master = rtnl_link_get(cache, link->l_master);
            dp_dump_line(p, line++, "  <master>%s</master>\n",
                       master ? master->l_name : "none");
            if (master)
                  rtnl_link_put(master);
      }

      if (link->ce_mask & LINK_ATTR_BRD)
            dp_dump_line(p, line++, "  <broadcast>%s</broadcast>\n",
                       nl_addr2str(link->l_bcast, buf, sizeof(buf)));

      if (link->ce_mask & LINK_ATTR_STATS) {
            dp_dump_line(p, line++, "  <stats>\n");
            for (i = 0; i <= RTNL_LINK_STATS_MAX; i++) {
                  rtnl_link_stat2str(i, buf, sizeof(buf));
                  dp_dump_line(p, line++,
                             "    <%s>%" PRIu64 "</%s>\n",
                             buf, link->l_stats[i], buf);
            }
            dp_dump_line(p, line++, "  </stats>\n");
      }

      if (link->l_info_ops && link->l_info_ops->io_dump[NL_DUMP_XML]) {
            dp_dump_line(p, line++, "  <info>\n");
            line = link->l_info_ops->io_dump[NL_DUMP_XML](link, p, line);
            dp_dump_line(p, line++, "  </info>\n");
      }

      dp_dump_line(p, line++, "</link>\n");

#if 0
      uint32_t    l_change;   /**< Change mask */
      struct rtnl_lifmap l_map;     /**< Interface device mapping */
#endif

      return line;
}

static int link_dump_env(struct nl_object *obj, struct nl_dump_params *p)
{
      struct rtnl_link *link = (struct rtnl_link *) obj;
      struct nl_cache *cache = dp_cache(obj);
      char buf[128];
      int i, line = 0;

      dp_dump_line(p, line++, "LINK_NAME=%s\n", link->l_name);
      dp_dump_line(p, line++, "LINK_IFINDEX=%u\n", link->l_index);
      dp_dump_line(p, line++, "LINK_FAMILY=%s\n",
                 nl_af2str(link->l_family, buf, sizeof(buf)));
      dp_dump_line(p, line++, "LINK_TYPE=%s\n",
                 nl_llproto2str(link->l_arptype, buf, sizeof(buf)));
      if (link->ce_mask & LINK_ATTR_ADDR)
            dp_dump_line(p, line++, "LINK_ADDRESS=%s\n",
                       nl_addr2str(link->l_addr, buf, sizeof(buf)));
      dp_dump_line(p, line++, "LINK_MTU=%u\n", link->l_mtu);
      dp_dump_line(p, line++, "LINK_TXQUEUELEN=%u\n", link->l_txqlen);
      dp_dump_line(p, line++, "LINK_WEIGHT=%u\n", link->l_weight);

      rtnl_link_flags2str(link->l_flags & ~IFF_RUNNING, buf, sizeof(buf));
      if (buf[0])
            dp_dump_line(p, line++, "LINK_FLAGS=%s\n", buf);

      if (link->ce_mask & LINK_ATTR_QDISC)
            dp_dump_line(p, line++, "LINK_QDISC=%s\n", link->l_qdisc);

      if (link->ce_mask & LINK_ATTR_LINK) {
            struct rtnl_link *ll = rtnl_link_get(cache, link->l_link);

            dp_dump_line(p, line++, "LINK_LINK_IFINDEX=%d\n", link->l_link);
            if (ll) {
                  dp_dump_line(p, line++, "LINK_LINK_IFNAME=%s\n",
                             ll->l_name);
                  rtnl_link_put(ll);
            }
      }

      if (link->ce_mask & LINK_ATTR_MASTER) {
            struct rtnl_link *master = rtnl_link_get(cache, link->l_master);
            dp_dump_line(p, line++, "LINK_MASTER=%s\n",
                       master ? master->l_name : "none");
            if (master)
                  rtnl_link_put(master);
      }

      if (link->ce_mask & LINK_ATTR_BRD)
            dp_dump_line(p, line++, "LINK_BROADCAST=%s\n",
                       nl_addr2str(link->l_bcast, buf, sizeof(buf)));

      if (link->ce_mask & LINK_ATTR_STATS) {
            for (i = 0; i <= RTNL_LINK_STATS_MAX; i++) {
                  char *c = buf;

                  sprintf(buf, "LINK_");
                  rtnl_link_stat2str(i, buf + 5, sizeof(buf) - 5);
                  while (*c) {
                        *c = toupper(*c);
                        c++;
                  }
                  dp_dump_line(p, line++,
                             "%s=%" PRIu64 "\n", buf, link->l_stats[i]);
            }
      }

      if (link->l_info_ops && link->l_info_ops->io_dump[NL_DUMP_ENV])
            line = link->l_info_ops->io_dump[NL_DUMP_ENV](link, p, line);

      return line;
}

#if 0
static int link_handle_event(struct nl_object *a, struct rtnl_link_event_cb *cb)
{
      struct rtnl_link *l = (struct rtnl_link *) a;
      struct nl_cache *c = dp_cache(a);
      int nevents = 0;

      if (l->l_change == ~0U) {
            if (l->ce_msgtype == RTM_NEWLINK)
                  cb->le_register(l);
            else
                  cb->le_unregister(l);

            return 1;
      }

      if (l->l_change & IFF_SLAVE) {
            if (l->l_flags & IFF_SLAVE) {
                  struct rtnl_link *m = rtnl_link_get(c, l->l_master);
                  cb->le_new_bonding(l, m);
                  if (m)
                        rtnl_link_put(m);
            } else
                  cb->le_cancel_bonding(l);
      }

#if 0
      if (l->l_change & IFF_UP && l->l_change & IFF_RUNNING)
            dp_dump_line(p, line++, "link %s changed state to %s.\n",
                  l->l_name, l->l_flags & IFF_UP ? "up" : "down");

      if (l->l_change & IFF_PROMISC) {
            dp_new_line(p, line++);
            dp_dump(p, "link %s %s promiscuous mode.\n",
                l->l_name, l->l_flags & IFF_PROMISC ? "entered" : "left");
      }

      if (line == 0)
            dp_dump_line(p, line++, "link %s sent unknown event.\n",
                       l->l_name);
#endif

      return nevents;
}
#endif

static int link_compare(struct nl_object *_a, struct nl_object *_b,
                  uint32_t attrs, int flags)
{
      struct rtnl_link *a = (struct rtnl_link *) _a;
      struct rtnl_link *b = (struct rtnl_link *) _b;
      int diff = 0;

#define LINK_DIFF(ATTR, EXPR) ATTR_DIFF(attrs, LINK_ATTR_##ATTR, a, b, EXPR)

      diff |= LINK_DIFF(IFINDEX,    a->l_index != b->l_index);
      diff |= LINK_DIFF(MTU,        a->l_mtu != b->l_mtu);
      diff |= LINK_DIFF(LINK,       a->l_link != b->l_link);
      diff |= LINK_DIFF(TXQLEN,     a->l_txqlen != b->l_txqlen);
      diff |= LINK_DIFF(WEIGHT,     a->l_weight != b->l_weight);
      diff |= LINK_DIFF(MASTER,     a->l_master != b->l_master);
      diff |= LINK_DIFF(FAMILY,     a->l_family != b->l_family);
      diff |= LINK_DIFF(OPERSTATE,  a->l_operstate != b->l_operstate);
      diff |= LINK_DIFF(LINKMODE,   a->l_linkmode != b->l_linkmode);
      diff |= LINK_DIFF(QDISC,      strcmp(a->l_qdisc, b->l_qdisc));
      diff |= LINK_DIFF(IFNAME,     strcmp(a->l_name, b->l_name));
      diff |= LINK_DIFF(ADDR,       nl_addr_cmp(a->l_addr, b->l_addr));
      diff |= LINK_DIFF(BRD,        nl_addr_cmp(a->l_bcast, b->l_bcast));

      if (flags & LOOSE_FLAG_COMPARISON)
            diff |= LINK_DIFF(FLAGS,
                          (a->l_flags ^ b->l_flags) & b->l_flag_mask);
      else
            diff |= LINK_DIFF(FLAGS, a->l_flags != b->l_flags);

#undef LINK_DIFF

      return diff;
}

static struct trans_tbl link_attrs[] = {
      __ADD(LINK_ATTR_MTU, mtu)
      __ADD(LINK_ATTR_LINK, link)
      __ADD(LINK_ATTR_TXQLEN, txqlen)
      __ADD(LINK_ATTR_WEIGHT, weight)
      __ADD(LINK_ATTR_MASTER, master)
      __ADD(LINK_ATTR_QDISC, qdisc)
      __ADD(LINK_ATTR_MAP, map)
      __ADD(LINK_ATTR_ADDR, address)
      __ADD(LINK_ATTR_BRD, broadcast)
      __ADD(LINK_ATTR_FLAGS, flags)
      __ADD(LINK_ATTR_IFNAME, name)
      __ADD(LINK_ATTR_IFINDEX, ifindex)
      __ADD(LINK_ATTR_FAMILY, family)
      __ADD(LINK_ATTR_ARPTYPE, arptype)
      __ADD(LINK_ATTR_STATS, stats)
      __ADD(LINK_ATTR_CHANGE, change)
      __ADD(LINK_ATTR_OPERSTATE, operstate)
      __ADD(LINK_ATTR_LINKMODE, linkmode)
};

static char *link_attrs2str(int attrs, char *buf, size_t len)
{
      return __flags2str(attrs, buf, len, link_attrs,
                     ARRAY_SIZE(link_attrs));
}

/**
 * @name Allocation/Freeing
 * @{
 */

struct rtnl_link *rtnl_link_alloc(void)
{
      return (struct rtnl_link *) nl_object_alloc(&link_obj_ops);
}

void rtnl_link_put(struct rtnl_link *link)
{
      nl_object_put((struct nl_object *) link);
}

/** @} */

/**
 * @name Cache Management
 * @{
 */


/**
 * Allocate link cache and fill in all configured links.
 * @arg handle          Netlink handle.
 *
 * Allocates a new link cache, initializes it properly and updates it
 * to include all links currently configured in the kernel.
 *
 * @note Free the memory after usage.
 * @return Newly allocated cache or NULL if an error occured.
 */
00874 struct nl_cache *rtnl_link_alloc_cache(struct nl_handle *handle)
{
      struct nl_cache * cache;
      
      cache = nl_cache_alloc(&rtnl_link_ops);
      if (cache == NULL)
            return NULL;
      
      if (handle && nl_cache_refill(handle, cache) < 0) {
            nl_cache_free(cache);
            return NULL;
      }

      return cache;
}

/**
 * Look up link by interface index in the provided cache
 * @arg cache           link cache
 * @arg ifindex         link interface index
 *
 * The caller owns a reference on the returned object and
 * must give the object back via rtnl_link_put().
 *
 * @return pointer to link inside the cache or NULL if no match was found.
 */
00900 struct rtnl_link *rtnl_link_get(struct nl_cache *cache, int ifindex)
{
      struct rtnl_link *link;

      if (cache->c_ops != &rtnl_link_ops)
            return NULL;

      nl_list_for_each_entry(link, &cache->c_items, ce_list) {
            if (link->l_index == ifindex) {
                  nl_object_get((struct nl_object *) link);
                  return link;
            }
      }

      return NULL;
}

/**
 * Look up link by link name in the provided cache
 * @arg cache           link cache
 * @arg name            link name
 *
 * The caller owns a reference on the returned object and
 * must give the object back via rtnl_link_put().
 *
 * @return pointer to link inside the cache or NULL if no match was found.
 */
00927 struct rtnl_link *rtnl_link_get_by_name(struct nl_cache *cache,
                               const char *name)
{
      struct rtnl_link *link;

      if (cache->c_ops != &rtnl_link_ops)
            return NULL;

      nl_list_for_each_entry(link, &cache->c_items, ce_list) {
            if (!strcmp(name, link->l_name)) {
                  nl_object_get((struct nl_object *) link);
                  return link;
            }
      }

      return NULL;
}

/** @} */

/**
 * @name Link Modifications
 * @{
 */

/**
 * Builds a netlink change request message to change link attributes
 * @arg old       link to be changed
 * @arg tmpl            template with requested changes
 * @arg flags           additional netlink message flags
 *
 * Builds a new netlink message requesting a change of link attributes.
 * The netlink message header isn't fully equipped with all relevant
 * fields and must be sent out via nl_send_auto_complete() or
 * supplemented as needed.
 * \a old must point to a link currently configured in the kernel
 * and \a tmpl must contain the attributes to be changed set via
 * \c rtnl_link_set_* functions.
 *
 * @return New netlink message
 * @note Not all attributes can be changed, see
 *       \ref link_changeable "Changeable Attributes" for more details.
 */
00970 struct nl_msg * rtnl_link_build_change_request(struct rtnl_link *old,
                                     struct rtnl_link *tmpl,
                                     int flags)
{
      struct nl_msg *msg;
      struct ifinfomsg ifi = {
            .ifi_family = old->l_family,
            .ifi_index = old->l_index,
      };

      if (tmpl->ce_mask & LINK_ATTR_FLAGS) {
            ifi.ifi_flags = old->l_flags & ~tmpl->l_flag_mask;
            ifi.ifi_flags |= tmpl->l_flags;
      }

      msg = nlmsg_alloc_simple(RTM_SETLINK, flags);
      if (!msg)
            goto nla_put_failure;

      if (nlmsg_append(msg, &ifi, sizeof(ifi), NLMSG_ALIGNTO) < 0)
            goto nla_put_failure;

      if (tmpl->ce_mask & LINK_ATTR_ADDR)
            NLA_PUT_ADDR(msg, IFLA_ADDRESS, tmpl->l_addr);

      if (tmpl->ce_mask & LINK_ATTR_BRD)
            NLA_PUT_ADDR(msg, IFLA_BROADCAST, tmpl->l_bcast);

      if (tmpl->ce_mask & LINK_ATTR_MTU)
            NLA_PUT_U32(msg, IFLA_MTU, tmpl->l_mtu);

      if (tmpl->ce_mask & LINK_ATTR_TXQLEN)
            NLA_PUT_U32(msg, IFLA_TXQLEN, tmpl->l_txqlen);

      if (tmpl->ce_mask & LINK_ATTR_WEIGHT)
            NLA_PUT_U32(msg, IFLA_WEIGHT, tmpl->l_weight);

      if (tmpl->ce_mask & LINK_ATTR_IFNAME)
            NLA_PUT_STRING(msg, IFLA_IFNAME, tmpl->l_name);

      if (tmpl->ce_mask & LINK_ATTR_OPERSTATE)
            NLA_PUT_U8(msg, IFLA_OPERSTATE, tmpl->l_operstate);

      if (tmpl->ce_mask & LINK_ATTR_LINKMODE)
            NLA_PUT_U8(msg, IFLA_LINKMODE, tmpl->l_linkmode);

      if ((tmpl->ce_mask & LINK_ATTR_LINKINFO) && tmpl->l_info_ops &&
          tmpl->l_info_ops->io_put_attrs) {
            struct nlattr *info;

            if (!(info = nla_nest_start(msg, IFLA_LINKINFO)))
                  goto nla_put_failure;

            NLA_PUT_STRING(msg, IFLA_INFO_KIND, tmpl->l_info_ops->io_name);

            if (tmpl->l_info_ops->io_put_attrs(msg, tmpl) < 0)
                  goto nla_put_failure;

            nla_nest_end(msg, info);
      }

      return msg;

nla_put_failure:
      nlmsg_free(msg);
      return NULL;
}

/**
 * Change link attributes
 * @arg handle          netlink handle
 * @arg old       link to be changed
 * @arg tmpl            template with requested changes
 * @arg flags           additional netlink message flags
 *
 * Builds a new netlink message by calling rtnl_link_build_change_request(),
 * sends the request to the kernel and waits for the next ACK to be
 * received, i.e. blocks until the request has been processed.
 *
 * @return 0 on success or a negative error code
 * @note Not all attributes can be changed, see
 *       \ref link_changeable "Changeable Attributes" for more details.
 */
01053 int rtnl_link_change(struct nl_handle *handle, struct rtnl_link *old,
                 struct rtnl_link *tmpl, int flags)
{
      int err;
      struct nl_msg *msg;
      
      msg = rtnl_link_build_change_request(old, tmpl, flags);
      if (!msg)
            return nl_errno(ENOMEM);
      
      err = nl_send_auto_complete(handle, msg);
      if (err < 0)
            return err;

      nlmsg_free(msg);
      return nl_wait_for_ack(handle);
}

/** @} */

/**
 * @name Name <-> Index Translations
 * @{
 */

/**
 * Translate an interface index to the corresponding link name
 * @arg cache           link cache
 * @arg ifindex         link interface index
 * @arg dst       destination buffer
 * @arg len       length of destination buffer
 *
 * Translates the specified interface index to the corresponding
 * link name and stores the name in the destination buffer.
 *
 * @return link name or NULL if no match was found.
 */
01090 char * rtnl_link_i2name(struct nl_cache *cache, int ifindex, char *dst,
                  size_t len)
{
      struct rtnl_link *link = rtnl_link_get(cache, ifindex);

      if (link) {
            strncpy(dst, link->l_name, len - 1);
            rtnl_link_put(link);
            return dst;
      }

      return NULL;
}

/**
 * Translate a link name to the corresponding interface index
 * @arg cache           link cache
 * @arg name            link name
 *
 * @return interface index or RTNL_LINK_NOT_FOUND if no match was found.
 */
01111 int rtnl_link_name2i(struct nl_cache *cache, const char *name)
{
      int ifindex = RTNL_LINK_NOT_FOUND;
      struct rtnl_link *link;
      
      link = rtnl_link_get_by_name(cache, name);
      if (link) {
            ifindex = link->l_index;
            rtnl_link_put(link);
      }

      return ifindex;
}

/** @} */

/**
 * @name Link Flags Translations
 * @{
 */

static struct trans_tbl link_flags[] = {
      __ADD(IFF_LOOPBACK, loopback)
      __ADD(IFF_BROADCAST, broadcast)
      __ADD(IFF_POINTOPOINT, pointopoint)
      __ADD(IFF_MULTICAST, multicast)
      __ADD(IFF_NOARP, noarp)
      __ADD(IFF_ALLMULTI, allmulti)
      __ADD(IFF_PROMISC, promisc)
      __ADD(IFF_MASTER, master)
      __ADD(IFF_SLAVE, slave)
      __ADD(IFF_DEBUG, debug)
      __ADD(IFF_DYNAMIC, dynamic)
      __ADD(IFF_AUTOMEDIA, automedia)
      __ADD(IFF_PORTSEL, portsel)
      __ADD(IFF_NOTRAILERS, notrailers)
      __ADD(IFF_UP, up)
      __ADD(IFF_RUNNING, running)
      __ADD(IFF_LOWER_UP, lowerup)
      __ADD(IFF_DORMANT, dormant)
      __ADD(IFF_ECHO, echo)
};

char * rtnl_link_flags2str(int flags, char *buf, size_t len)
{
      return __flags2str(flags, buf, len, link_flags,
                     ARRAY_SIZE(link_flags));
}

int rtnl_link_str2flags(const char *name)
{
      return __str2flags(name, link_flags, ARRAY_SIZE(link_flags));
}

/** @} */

/**
 * @name Link Statistics Translations
 * @{
 */

static struct trans_tbl link_stats[] = {
      __ADD(RTNL_LINK_RX_PACKETS, rx_packets)
      __ADD(RTNL_LINK_TX_PACKETS, tx_packets)
      __ADD(RTNL_LINK_RX_BYTES, rx_bytes)
      __ADD(RTNL_LINK_TX_BYTES, tx_bytes)
      __ADD(RTNL_LINK_RX_ERRORS, rx_errors)
      __ADD(RTNL_LINK_TX_ERRORS, tx_errors)
      __ADD(RTNL_LINK_RX_DROPPED, rx_dropped)
      __ADD(RTNL_LINK_TX_DROPPED, tx_dropped)
      __ADD(RTNL_LINK_RX_COMPRESSED, rx_compressed)
      __ADD(RTNL_LINK_TX_COMPRESSED, tx_compressed)
      __ADD(RTNL_LINK_RX_FIFO_ERR, rx_fifo_err)
      __ADD(RTNL_LINK_TX_FIFO_ERR, tx_fifo_err)
      __ADD(RTNL_LINK_RX_LEN_ERR, rx_len_err)
      __ADD(RTNL_LINK_RX_OVER_ERR, rx_over_err)
      __ADD(RTNL_LINK_RX_CRC_ERR, rx_crc_err)
      __ADD(RTNL_LINK_RX_FRAME_ERR, rx_frame_err)
      __ADD(RTNL_LINK_RX_MISSED_ERR, rx_missed_err)
      __ADD(RTNL_LINK_TX_ABORT_ERR, tx_abort_err)
      __ADD(RTNL_LINK_TX_CARRIER_ERR, tx_carrier_err)
      __ADD(RTNL_LINK_TX_HBEAT_ERR, tx_hbeat_err)
      __ADD(RTNL_LINK_TX_WIN_ERR, tx_win_err)
      __ADD(RTNL_LINK_TX_COLLISIONS, tx_collision)
      __ADD(RTNL_LINK_MULTICAST, multicast)
};

char *rtnl_link_stat2str(int st, char *buf, size_t len)
{
      return __type2str(st, buf, len, link_stats, ARRAY_SIZE(link_stats));
}

int rtnl_link_str2stat(const char *name)
{
      return __str2type(name, link_stats, ARRAY_SIZE(link_stats));
}

/** @} */

/**
 * @name Link Operstate Translations
 * @{
 */

static struct trans_tbl link_operstates[] = {
      __ADD(IF_OPER_UNKNOWN, unknown)
      __ADD(IF_OPER_NOTPRESENT, notpresent)
      __ADD(IF_OPER_DOWN, down)
      __ADD(IF_OPER_LOWERLAYERDOWN, lowerlayerdown)
      __ADD(IF_OPER_TESTING, testing)
      __ADD(IF_OPER_DORMANT, dormant)
      __ADD(IF_OPER_UP, up)
};

char *rtnl_link_operstate2str(int st, char *buf, size_t len)
{
      return __type2str(st, buf, len, link_operstates,
                    ARRAY_SIZE(link_operstates));
}

int rtnl_link_str2operstate(const char *name)
{
      return __str2type(name, link_operstates,
                    ARRAY_SIZE(link_operstates));
}

/** @} */

/**
 * @name Link Mode Translations
 * @{
 */

static struct trans_tbl link_modes[] = {
      __ADD(IF_LINK_MODE_DEFAULT, default)
      __ADD(IF_LINK_MODE_DORMANT, dormant)
};

char *rtnl_link_mode2str(int st, char *buf, size_t len)
{
      return __type2str(st, buf, len, link_modes, ARRAY_SIZE(link_modes));
}

int rtnl_link_str2mode(const char *name)
{
      return __str2type(name, link_modes, ARRAY_SIZE(link_modes));
}

/** @} */

/**
 * @name Attributes
 * @{
 */

void rtnl_link_set_qdisc(struct rtnl_link *link, const char *qdisc)
{
      strncpy(link->l_qdisc, qdisc, sizeof(link->l_qdisc) - 1);
      link->ce_mask |= LINK_ATTR_QDISC;
}

char *rtnl_link_get_qdisc(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_QDISC)
            return link->l_qdisc;
      else
            return NULL;
}

void rtnl_link_set_name(struct rtnl_link *link, const char *name)
{
      strncpy(link->l_name, name, sizeof(link->l_name) - 1);
      link->ce_mask |= LINK_ATTR_IFNAME;
}

char *rtnl_link_get_name(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_IFNAME)
            return link->l_name;
      else
            return NULL;
}

static inline void __assign_addr(struct rtnl_link *link, struct nl_addr **pos,
                         struct nl_addr *new, int flag)
{
      if (*pos)
            nl_addr_put(*pos);

      nl_addr_get(new);
      *pos = new;

      link->ce_mask |= flag;
}

void rtnl_link_set_addr(struct rtnl_link *link, struct nl_addr *addr)
{
      __assign_addr(link, &link->l_addr, addr, LINK_ATTR_ADDR);
}

struct nl_addr *rtnl_link_get_addr(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_ADDR)
            return link->l_addr;
      else
            return NULL;
}

void rtnl_link_set_broadcast(struct rtnl_link *link, struct nl_addr *brd)
{
      __assign_addr(link, &link->l_bcast, brd, LINK_ATTR_BRD);
}

struct nl_addr *rtnl_link_get_broadcast(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_BRD)
            return link->l_bcast;
      else
            return NULL;
}

void rtnl_link_set_flags(struct rtnl_link *link, unsigned int flags)
{
      link->l_flag_mask |= flags;
      link->l_flags |= flags;
      link->ce_mask |= LINK_ATTR_FLAGS;
}

void rtnl_link_unset_flags(struct rtnl_link *link, unsigned int flags)
{
      link->l_flag_mask |= flags;
      link->l_flags &= ~flags;
      link->ce_mask |= LINK_ATTR_FLAGS;
}

unsigned int rtnl_link_get_flags(struct rtnl_link *link)
{
      return link->l_flags;
}

void rtnl_link_set_family(struct rtnl_link *link, int family)
{
      link->l_family = family;
      link->ce_mask |= LINK_ATTR_FAMILY;
}

int rtnl_link_get_family(struct rtnl_link *link)
{
      if (link->l_family & LINK_ATTR_FAMILY)
            return link->l_family;
      else
            return AF_UNSPEC;
}

void rtnl_link_set_arptype(struct rtnl_link *link, unsigned int arptype)
{
      link->l_arptype = arptype;
}

unsigned int rtnl_link_get_arptype(struct rtnl_link *link)
{
      return link->l_arptype;
}

void rtnl_link_set_ifindex(struct rtnl_link *link, int ifindex)
{
      link->l_index = ifindex;
      link->ce_mask |= LINK_ATTR_IFINDEX;
}

int rtnl_link_get_ifindex(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_IFINDEX)
            return link->l_index;
      else
            return RTNL_LINK_NOT_FOUND;
}

void rtnl_link_set_mtu(struct rtnl_link *link, unsigned int mtu)
{
      link->l_mtu = mtu;
      link->ce_mask |= LINK_ATTR_MTU;
}

unsigned int rtnl_link_get_mtu(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_MTU)
            return link->l_mtu;
      else
            return 0;
}

void rtnl_link_set_txqlen(struct rtnl_link *link, unsigned int txqlen)
{
      link->l_txqlen = txqlen;
      link->ce_mask |= LINK_ATTR_TXQLEN;
}

unsigned int rtnl_link_get_txqlen(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_TXQLEN)
            return link->l_txqlen;
      else
            return UINT_MAX;
}

void rtnl_link_set_weight(struct rtnl_link *link, unsigned int weight)
{
      link->l_weight = weight;
      link->ce_mask |= LINK_ATTR_WEIGHT;
}

unsigned int rtnl_link_get_weight(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_WEIGHT)
            return link->l_weight;
      else
            return UINT_MAX;
}

void rtnl_link_set_link(struct rtnl_link *link, int ifindex)
{
      link->l_link = ifindex;
      link->ce_mask |= LINK_ATTR_LINK;
}

int rtnl_link_get_link(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_LINK)
            return link->l_link;
      else
            return RTNL_LINK_NOT_FOUND;
}

void rtnl_link_set_master(struct rtnl_link *link, int ifindex)
{
      link->l_master = ifindex;
      link->ce_mask |= LINK_ATTR_MASTER;
}

int rtnl_link_get_master(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_MASTER)
            return link->l_master;
      else
            return RTNL_LINK_NOT_FOUND;
}

void rtnl_link_set_operstate(struct rtnl_link *link, uint8_t operstate)
{
      link->l_operstate = operstate;
      link->ce_mask |= LINK_ATTR_OPERSTATE;
}

uint8_t rtnl_link_get_operstate(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_OPERSTATE)
            return link->l_operstate;
      else
            return IF_OPER_UNKNOWN;
}

void rtnl_link_set_linkmode(struct rtnl_link *link, uint8_t linkmode)
{
      link->l_linkmode = linkmode;
      link->ce_mask |= LINK_ATTR_LINKMODE;
}

uint8_t rtnl_link_get_linkmode(struct rtnl_link *link)
{
      if (link->ce_mask & LINK_ATTR_LINKMODE)
            return link->l_linkmode;
      else
            return IF_LINK_MODE_DEFAULT;
}

uint64_t rtnl_link_get_stat(struct rtnl_link *link, int id)
{
      if (id < 0 || id > RTNL_LINK_STATS_MAX)
            return 0;

      return link->l_stats[id];
}

/**
 * Specify the info type of a link
 * @arg link      link object
 * @arg type      info type
 *
 * Looks up the info type and prepares the link to store info type
 * specific attributes. If an info type has been assigned already
 * it will be released with all changes lost.
 *
 * @return 0 on success or a negative errror code.
 */
01506 int rtnl_link_set_info_type(struct rtnl_link *link, const char *type)
{
      struct rtnl_link_info_ops *io;
      int err;

      if ((io = rtnl_link_info_ops_lookup(type)) == NULL)
            return nl_error(ENOENT, "No such link info type exists");

      if (link->l_info_ops)
            release_link_info(link);

      if ((err = io->io_alloc(link)) < 0)
            return err;

      link->l_info_ops = io;

      return 0;
}

/**
 * Return info type of a link
 * @arg link      link object
 *
 * @note The returned pointer is only valid as long as the link exists
 * @return Info type name or NULL if unknown.
 */
01532 char *rtnl_link_get_info_type(struct rtnl_link *link)
{
      if (link->l_info_ops)
            return link->l_info_ops->io_name;
      else
            return NULL;
}

/** @} */

static struct nl_object_ops link_obj_ops = {
      .oo_name          = "route/link",
      .oo_size          = sizeof(struct rtnl_link),
      .oo_free_data           = link_free_data,
      .oo_clone         = link_clone,
      .oo_dump[NL_DUMP_BRIEF] = link_dump_brief,
      .oo_dump[NL_DUMP_FULL]  = link_dump_full,
      .oo_dump[NL_DUMP_STATS] = link_dump_stats,
      .oo_dump[NL_DUMP_XML]   = link_dump_xml,
      .oo_dump[NL_DUMP_ENV]   = link_dump_env,
      .oo_compare       = link_compare,
      .oo_attrs2str           = link_attrs2str,
      .oo_id_attrs            = LINK_ATTR_IFINDEX,
};

static struct nl_af_group link_groups[] = {
      { AF_UNSPEC,      RTNLGRP_LINK },
      { END_OF_GROUP_LIST },
};

static struct nl_cache_ops rtnl_link_ops = {
      .co_name          = "route/link",
      .co_hdrsize       = sizeof(struct ifinfomsg),
      .co_msgtypes            = {
                              { RTM_NEWLINK, NL_ACT_NEW, "new" },
                              { RTM_DELLINK, NL_ACT_DEL, "del" },
                              { RTM_GETLINK, NL_ACT_GET, "get" },
                              END_OF_MSGTYPES_LIST,
                          },
      .co_protocol            = NETLINK_ROUTE,
      .co_groups        = link_groups,
      .co_request_update      = link_request_update,
      .co_msg_parser          = link_msg_parser,
      .co_obj_ops       = &link_obj_ops,
};

static void __init link_init(void)
{
      nl_cache_mngt_register(&rtnl_link_ops);
}

static void __exit link_exit(void)
{
      nl_cache_mngt_unregister(&rtnl_link_ops);
}

/** @} */

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