addr.c

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * Copyright (c) 2003-2012 Thomas Graf <tgraf@suug.ch>
 * Copyright (c) 2003-2006 Baruch Even <baruch@ev-en.org>
 * Copyright (c) 2003-2006 Mediatrix Telecom, inc. <ericb@mediatrix.com>
 */
 
/**
 * @ingroup rtnl
 * @defgroup rtaddr Addresses
 * @brief
 *
 * @note The maximum size of an address label is IFNAMSIZ.
 *
 * @note The address may not contain a prefix length if the peer address
 *       has been specified already.
 *
 * @par 1) Address Addition
 * @code
 * // Allocate an empty address object to be filled out with the attributes
 * // of the new address.
 * struct rtnl_addr *addr = rtnl_addr_alloc();
 *
 * // Fill out the mandatory attributes of the new address. Setting the
 * // local address will automatically set the address family and the
 * // prefix length to the correct values.
 * rtnl_addr_set_ifindex(addr, ifindex);
 * rtnl_addr_set_local(addr, local_addr);
 *
 * // The label of the address can be specified, currently only supported
 * // by IPv4 and DECnet.
 * rtnl_addr_set_label(addr, "mylabel");
 *
 * // The peer address can be specified if necessary, in either case a peer
 * // address will be sent to the kernel in order to fullfil the interface
 * // requirements. If none is set, it will equal the local address.
 * // Note: Real peer addresses are only supported by IPv4 for now.
 * rtnl_addr_set_peer(addr, peer_addr);
 *
 * // In case you want to have the address have a scope other than global
 * // it may be overwritten using rtnl_addr_set_scope(). The scope currently
 * // cannot be set for IPv6 addresses.
 * rtnl_addr_set_scope(addr, rtnl_str2scope("site"));
 *
 * // Broadcast address may be specified using the relevant
 * // functions, the address family will be verified if one of the other
 * // addresses has been set already. Currently only works for IPv4.
 * rtnl_addr_set_broadcast(addr, broadcast_addr);
 *
 * // Build the netlink message and send it to the kernel, the operation will
 * // block until the operation has been completed. Alternatively the required
 * // netlink message can be built using rtnl_addr_build_add_request() to be
 * // sent out using nl_send_auto_complete().
 * rtnl_addr_add(sk, addr, 0);
 *
 * // Free the memory
 * rtnl_addr_put(addr);
 * @endcode
 *
 * @par 2) Address Deletion
 * @code
 * // Allocate an empty address object to be filled out with the attributes
 * // matching the address to be deleted. Alternatively a fully equipped
 * // address object out of a cache can be used instead.
 * struct rtnl_addr *addr = rtnl_addr_alloc();
 *
 * // The only mandatory parameter besides the address family is the interface
 * // index the address is on, i.e. leaving out all other parameters will
 * // result in all addresses of the specified address family interface tuple
 * // to be deleted.
 * rtnl_addr_set_ifindex(addr, ifindex);
 *
 * // Specyfing the address family manually is only required if neither the
 * // local nor peer address have been specified.
 * rtnl_addr_set_family(addr, AF_INET);
 *
 * // Specyfing the local address is optional but the best choice to delete
 * // specific addresses.
 * rtnl_addr_set_local(addr, local_addr);
 *
 * // The label of the address can be specified, currently only supported
 * // by IPv4 and DECnet.
 * rtnl_addr_set_label(addr, "mylabel");
 *
 * // The peer address can be specified if necessary, in either case a peer
 * // address will be sent to the kernel in order to fullfil the interface
 * // requirements. If none is set, it will equal the local address.
 * // Note: Real peer addresses are only supported by IPv4 for now.
 * rtnl_addr_set_peer(addr, peer_addr);
 *
 * // Build the netlink message and send it to the kernel, the operation will
 * // block until the operation has been completed. Alternatively the required
 * // netlink message can be built using rtnl_addr_build_delete_request()
 * // to be sent out using nl_send_auto_complete().
 * rtnl_addr_delete(sk, addr, 0);
 *
 * // Free the memory
 * rtnl_addr_put(addr);
 * @endcode
 * @{
 */
 
#include <netlink-private/netlink.h>
#include <netlink/netlink.h>
#include <netlink/route/rtnl.h>
#include <netlink/route/addr.h>
#include <netlink/route/route.h>
#include <netlink/route/link.h>
#include <netlink/utils.h>
 
/** @cond SKIP */
#define ADDR_ATTR_FAMILY        0x0001
#define ADDR_ATTR_PREFIXLEN     0x0002
#define ADDR_ATTR_FLAGS         0x0004
#define ADDR_ATTR_SCOPE         0x0008
#define ADDR_ATTR_IFINDEX       0x0010
#define ADDR_ATTR_LABEL         0x0020
#define ADDR_ATTR_CACHEINFO     0x0040
#define ADDR_ATTR_PEER          0x0080
#define ADDR_ATTR_LOCAL         0x0100
#define ADDR_ATTR_BROADCAST     0x0200
#define ADDR_ATTR_MULTICAST     0x0400
#define ADDR_ATTR_ANYCAST       0x0800
 
static struct nl_cache_ops rtnl_addr_ops;
static struct nl_object_ops addr_obj_ops;
/** @endcond */
 
static void addr_constructor(struct nl_object *obj)
{
        struct rtnl_addr *addr = nl_object_priv(obj);
 
        addr->a_scope = RT_SCOPE_NOWHERE;
}
 
static void addr_free_data(struct nl_object *obj)
{
        struct rtnl_addr *addr = nl_object_priv(obj);
 
        if (!addr)
                return;
 
        nl_addr_put(addr->a_peer);
        nl_addr_put(addr->a_local);
        nl_addr_put(addr->a_bcast);
        nl_addr_put(addr->a_multicast);
        nl_addr_put(addr->a_anycast);
        rtnl_link_put(addr->a_link);
}
 
static int addr_clone(struct nl_object *_dst, struct nl_object *_src)
{
        struct rtnl_addr *dst = nl_object_priv(_dst);
        struct rtnl_addr *src = nl_object_priv(_src);
 
        dst->a_peer = NULL;
        dst->a_local = NULL;
        dst->a_bcast = NULL;
        dst->a_anycast = NULL;
        dst->a_multicast = NULL;
        dst->a_link = NULL;
 
        if (src->a_link) {
                nl_object_get(OBJ_CAST(src->a_link));
                dst->a_link = src->a_link;
        }
 
        if (src->a_peer)
                if (!(dst->a_peer = nl_addr_clone(src->a_peer)))
                        return -NLE_NOMEM;
 
        if (src->a_local)
                if (!(dst->a_local = nl_addr_clone(src->a_local)))
                        return -NLE_NOMEM;
 
        if (src->a_bcast)
                if (!(dst->a_bcast = nl_addr_clone(src->a_bcast)))
                        return -NLE_NOMEM;
 
        if (src->a_multicast)
                if (!(dst->a_multicast = nl_addr_clone(src->a_multicast)))
                        return -NLE_NOMEM;
 
        if (src->a_anycast)
                if (!(dst->a_anycast = nl_addr_clone(src->a_anycast)))
                        return -NLE_NOMEM;
 
        return 0;
}
 
static struct nla_policy addr_policy[IFA_MAX+1] = {
        [IFA_LABEL]     = { .type = NLA_STRING,
                            .maxlen = IFNAMSIZ },
        [IFA_CACHEINFO] = { .minlen = sizeof(struct ifa_cacheinfo) },
};
 
static int addr_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
                           struct nlmsghdr *nlh, struct nl_parser_param *pp)
{
        struct rtnl_addr *addr;
        struct ifaddrmsg *ifa;
        struct nlattr *tb[IFA_MAX+1];
        int err, family;
        struct nl_cache *link_cache;
        struct nl_addr *plen_addr = NULL;
 
        addr = rtnl_addr_alloc();
        if (!addr)
                return -NLE_NOMEM;
 
        addr->ce_msgtype = nlh->nlmsg_type;
 
        err = nlmsg_parse(nlh, sizeof(*ifa), tb, IFA_MAX, addr_policy);
        if (err < 0)
                goto errout;
 
        ifa = nlmsg_data(nlh);
        addr->a_family = family = ifa->ifa_family;
        addr->a_prefixlen = ifa->ifa_prefixlen;
        addr->a_scope = ifa->ifa_scope;
        addr->a_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) :
                                        ifa->ifa_flags;
        addr->a_ifindex = ifa->ifa_index;
 
        addr->ce_mask = (ADDR_ATTR_FAMILY | ADDR_ATTR_PREFIXLEN |
                         ADDR_ATTR_FLAGS | ADDR_ATTR_SCOPE | ADDR_ATTR_IFINDEX);
 
        if (tb[IFA_LABEL]) {
                nla_strlcpy(addr->a_label, tb[IFA_LABEL], IFNAMSIZ);
                addr->ce_mask |= ADDR_ATTR_LABEL;
        }
 
        /* IPv6 only */
        if (tb[IFA_CACHEINFO]) {
                struct ifa_cacheinfo *ca;
                
                ca = nla_data(tb[IFA_CACHEINFO]);
                addr->a_cacheinfo.aci_prefered = ca->ifa_prefered;
                addr->a_cacheinfo.aci_valid = ca->ifa_valid;
                addr->a_cacheinfo.aci_cstamp = ca->cstamp;
                addr->a_cacheinfo.aci_tstamp = ca->tstamp;
                addr->ce_mask |= ADDR_ATTR_CACHEINFO;
        }
 
        if (family == AF_INET) {
                uint32_t null = 0;
 
                /* for IPv4/AF_INET, kernel always sets IFA_LOCAL and IFA_ADDRESS, unless it
                 * is effectively 0.0.0.0. */
                if (tb[IFA_LOCAL])
                        addr->a_local = nl_addr_alloc_attr(tb[IFA_LOCAL], family);
                else
                        addr->a_local = nl_addr_build(family, &null, sizeof (null));
                if (!addr->a_local)
                        goto errout_nomem;
                addr->ce_mask |= ADDR_ATTR_LOCAL;
 
                if (tb[IFA_ADDRESS])
                        addr->a_peer = nl_addr_alloc_attr(tb[IFA_ADDRESS], family);
                else
                        addr->a_peer = nl_addr_build(family, &null, sizeof (null));
                if (!addr->a_peer)
                        goto errout_nomem;
 
                if (!nl_addr_cmp (addr->a_local, addr->a_peer)) {
                        /* having IFA_ADDRESS equal to IFA_LOCAL does not really mean
                         * there is no peer. It means the peer is equal to the local address,
                         * which is the case for "normal" addresses.
                         *
                         * Still, clear the peer and pretend it is unset for backward
                         * compatibility. */
                        nl_addr_put(addr->a_peer);
                        addr->a_peer = NULL;
                } else
                        addr->ce_mask |= ADDR_ATTR_PEER;
 
                plen_addr = addr->a_local;
        } else {
                if (tb[IFA_LOCAL]) {
                        addr->a_local = nl_addr_alloc_attr(tb[IFA_LOCAL], family);
                        if (!addr->a_local)
                                goto errout_nomem;
                        addr->ce_mask |= ADDR_ATTR_LOCAL;
                        plen_addr = addr->a_local;
                }
 
                if (tb[IFA_ADDRESS]) {
                        struct nl_addr *a;
 
                        a = nl_addr_alloc_attr(tb[IFA_ADDRESS], family);
                        if (!a)
                                goto errout_nomem;
 
                        /* IPv6 sends the local address as IFA_ADDRESS with
                         * no IFA_LOCAL, IPv4 sends both IFA_LOCAL and IFA_ADDRESS
                         * with IFA_ADDRESS being the peer address if they differ */
                        if (!tb[IFA_LOCAL] || !nl_addr_cmp(a, addr->a_local)) {
                                nl_addr_put(addr->a_local);
                                addr->a_local = a;
                                addr->ce_mask |= ADDR_ATTR_LOCAL;
                        } else {
                                addr->a_peer = a;
                                addr->ce_mask |= ADDR_ATTR_PEER;
                        }
 
                        plen_addr = a;
                }
        }
 
        if (plen_addr)
                nl_addr_set_prefixlen(plen_addr, addr->a_prefixlen);
 
        /* IPv4 only */
        if (tb[IFA_BROADCAST]) {
                addr->a_bcast = nl_addr_alloc_attr(tb[IFA_BROADCAST], family);
                if (!addr->a_bcast)
                        goto errout_nomem;
 
                addr->ce_mask |= ADDR_ATTR_BROADCAST;
        }
 
        /* IPv6 only */
        if (tb[IFA_MULTICAST]) {
                addr->a_multicast = nl_addr_alloc_attr(tb[IFA_MULTICAST],
                                                       family);
                if (!addr->a_multicast)
                        goto errout_nomem;
 
                addr->ce_mask |= ADDR_ATTR_MULTICAST;
        }
 
        /* IPv6 only */
        if (tb[IFA_ANYCAST]) {
                addr->a_anycast = nl_addr_alloc_attr(tb[IFA_ANYCAST],
                                                       family);
                if (!addr->a_anycast)
                        goto errout_nomem;
 
                addr->ce_mask |= ADDR_ATTR_ANYCAST;
        }
 
        if ((link_cache = __nl_cache_mngt_require("route/link"))) {
                struct rtnl_link *link;
 
                if ((link = rtnl_link_get(link_cache, addr->a_ifindex))) {
                        rtnl_addr_set_link(addr, link);
 
                        /* rtnl_addr_set_link incs refcnt */
                        rtnl_link_put(link);
                }
        }
 
        err = pp->pp_cb((struct nl_object *) addr, pp);
errout:
        rtnl_addr_put(addr);
 
        return err;
 
errout_nomem:
        err = -NLE_NOMEM;
        goto errout;
}
 
static int addr_request_update(struct nl_cache *cache, struct nl_sock *sk)
{
        return nl_rtgen_request(sk, RTM_GETADDR, AF_UNSPEC, NLM_F_DUMP);
}
 
static void addr_dump_line(struct nl_object *obj, struct nl_dump_params *p)
{
        struct rtnl_addr *addr = (struct rtnl_addr *) obj;
        struct nl_cache *link_cache;
        char buf[128];
 
        link_cache = nl_cache_mngt_require_safe("route/link");
 
        if (addr->ce_mask & ADDR_ATTR_LOCAL)
                nl_dump_line(p, "%s",
                        nl_addr2str(addr->a_local, buf, sizeof(buf)));
        else
                nl_dump_line(p, "none");
 
        if (addr->ce_mask & ADDR_ATTR_PEER)
                nl_dump(p, " peer %s",
                        nl_addr2str(addr->a_peer, buf, sizeof(buf)));
 
        nl_dump(p, " %s ", nl_af2str(addr->a_family, buf, sizeof(buf)));
 
        if (link_cache)
                nl_dump(p, "dev %s ",
                        rtnl_link_i2name(link_cache, addr->a_ifindex,
                                         buf, sizeof(buf)));
        else
                nl_dump(p, "dev %d ", addr->a_ifindex);
 
        nl_dump(p, "scope %s",
                rtnl_scope2str(addr->a_scope, buf, sizeof(buf)));
 
        rtnl_addr_flags2str(addr->a_flags, buf, sizeof(buf));
        if (buf[0])
                nl_dump(p, " <%s>", buf);
 
        nl_dump(p, "\n");
 
        if (link_cache)
                nl_cache_put(link_cache);
}
 
static void addr_dump_details(struct nl_object *obj, struct nl_dump_params *p)
{
        struct rtnl_addr *addr = (struct rtnl_addr *) obj;
        char buf[128];
 
        addr_dump_line(obj, p);
 
        if (addr->ce_mask & (ADDR_ATTR_LABEL | ADDR_ATTR_BROADCAST |
                             ADDR_ATTR_MULTICAST)) {
                nl_dump_line(p, "  ");
 
                if (addr->ce_mask & ADDR_ATTR_LABEL)
                        nl_dump(p, " label %s", addr->a_label);
 
                if (addr->ce_mask & ADDR_ATTR_BROADCAST)
                        nl_dump(p, " broadcast %s",
                                nl_addr2str(addr->a_bcast, buf, sizeof(buf)));
 
                if (addr->ce_mask & ADDR_ATTR_MULTICAST)
                        nl_dump(p, " multicast %s",
                                nl_addr2str(addr->a_multicast, buf,
                                              sizeof(buf)));
 
                if (addr->ce_mask & ADDR_ATTR_ANYCAST)
                        nl_dump(p, " anycast %s",
                                nl_addr2str(addr->a_anycast, buf,
                                              sizeof(buf)));
 
                nl_dump(p, "\n");
        }
 
        if (addr->ce_mask & ADDR_ATTR_CACHEINFO) {
                struct rtnl_addr_cacheinfo *ci = &addr->a_cacheinfo;
 
                nl_dump_line(p, "   valid-lifetime %s",
                             ci->aci_valid == 0xFFFFFFFFU ? "forever" :
                             nl_msec2str(ci->aci_valid * 1000,
                                           buf, sizeof(buf)));
 
                nl_dump(p, " preferred-lifetime %s\n",
                        ci->aci_prefered == 0xFFFFFFFFU ? "forever" :
                        nl_msec2str(ci->aci_prefered * 1000,
                                      buf, sizeof(buf)));
 
                nl_dump_line(p, "   created boot-time+%s ",
                             nl_msec2str(addr->a_cacheinfo.aci_cstamp * 10,
                                           buf, sizeof(buf)));
                    
                nl_dump(p, "last-updated boot-time+%s\n",
                        nl_msec2str(addr->a_cacheinfo.aci_tstamp * 10,
                                      buf, sizeof(buf)));
        }
}
 
static void addr_dump_stats(struct nl_object *obj, struct nl_dump_params *p)
{
        addr_dump_details(obj, p);
}
 
static uint32_t addr_id_attrs_get(struct nl_object *obj)
{
        struct rtnl_addr *addr = (struct rtnl_addr *)obj;
        uint32_t rv;
 
        switch (addr->a_family) {
        case AF_INET:
                rv = (ADDR_ATTR_FAMILY | ADDR_ATTR_IFINDEX |
                      ADDR_ATTR_LOCAL | ADDR_ATTR_PREFIXLEN);
                if (addr->a_peer)
                        rv |= ADDR_ATTR_PEER;
                return rv;
        case AF_INET6:
                return (ADDR_ATTR_FAMILY | ADDR_ATTR_IFINDEX |
                        ADDR_ATTR_LOCAL);
        default:
                return (ADDR_ATTR_FAMILY | ADDR_ATTR_IFINDEX |
                        ADDR_ATTR_LOCAL | ADDR_ATTR_PREFIXLEN);
        }
}
 
static uint64_t addr_compare(struct nl_object *_a, struct nl_object *_b,
                             uint64_t attrs, int flags)
{
        struct rtnl_addr *a = (struct rtnl_addr *) _a;
        struct rtnl_addr *b = (struct rtnl_addr *) _b;
        uint64_t diff = 0;
 
#define ADDR_DIFF(ATTR, EXPR) ATTR_DIFF(attrs, ADDR_ATTR_##ATTR, a, b, EXPR)
 
        diff |= ADDR_DIFF(IFINDEX,      a->a_ifindex != b->a_ifindex);
        diff |= ADDR_DIFF(FAMILY,       a->a_family != b->a_family);
        diff |= ADDR_DIFF(SCOPE,        a->a_scope != b->a_scope);
        diff |= ADDR_DIFF(LABEL,        strcmp(a->a_label, b->a_label));
        if (attrs & ADDR_ATTR_PEER) {
                if (   (flags & ID_COMPARISON)
                    && a->a_family == AF_INET
                    && b->a_family == AF_INET
                    && a->a_peer
                    && b->a_peer
                    && a->a_prefixlen == b->a_prefixlen) {
                        /* when comparing two IPv4 addresses for id-equality, the network part
                         * of the PEER address shall be compared.
                         */
                        diff |= ADDR_DIFF(PEER, nl_addr_cmp_prefix(a->a_peer, b->a_peer));
                } else
                        diff |= ADDR_DIFF(PEER, nl_addr_cmp(a->a_peer, b->a_peer));
        }
        diff |= ADDR_DIFF(LOCAL,        nl_addr_cmp(a->a_local, b->a_local));
        diff |= ADDR_DIFF(MULTICAST,    nl_addr_cmp(a->a_multicast,
                                                    b->a_multicast));
        diff |= ADDR_DIFF(BROADCAST,    nl_addr_cmp(a->a_bcast, b->a_bcast));
        diff |= ADDR_DIFF(ANYCAST,      nl_addr_cmp(a->a_anycast, b->a_anycast));
        diff |= ADDR_DIFF(CACHEINFO,    memcmp(&a->a_cacheinfo, &b->a_cacheinfo,
                                               sizeof (a->a_cacheinfo)));
 
        if (flags & LOOSE_COMPARISON)
                diff |= ADDR_DIFF(FLAGS,
                                  (a->a_flags ^ b->a_flags) & b->a_flag_mask);
        else
                diff |= ADDR_DIFF(FLAGS, a->a_flags != b->a_flags);
 
#undef ADDR_DIFF
 
        return diff;
}
 
static const struct trans_tbl addr_attrs[] = {
        __ADD(ADDR_ATTR_FAMILY, family),
        __ADD(ADDR_ATTR_PREFIXLEN, prefixlen),
        __ADD(ADDR_ATTR_FLAGS, flags),
        __ADD(ADDR_ATTR_SCOPE, scope),
        __ADD(ADDR_ATTR_IFINDEX, ifindex),
        __ADD(ADDR_ATTR_LABEL, label),
        __ADD(ADDR_ATTR_CACHEINFO, cacheinfo),
        __ADD(ADDR_ATTR_PEER, peer),
        __ADD(ADDR_ATTR_LOCAL, local),
        __ADD(ADDR_ATTR_BROADCAST, broadcast),
        __ADD(ADDR_ATTR_MULTICAST, multicast),
};
 
static char *addr_attrs2str(int attrs, char *buf, size_t len)
{
        return __flags2str(attrs, buf, len, addr_attrs,
                           ARRAY_SIZE(addr_attrs));
}
 
/**
 * @name Allocation/Freeing
 * @{
 */
 
struct rtnl_addr *rtnl_addr_alloc(void)
{
        return (struct rtnl_addr *) nl_object_alloc(&addr_obj_ops);
}
 
void rtnl_addr_put(struct rtnl_addr *addr)
{
        nl_object_put((struct nl_object *) addr);
}
 
/** @} */
 
/**
 * @name Cache Management
 * @{
 */
 
int rtnl_addr_alloc_cache(struct nl_sock *sk, struct nl_cache **result)
{
        return nl_cache_alloc_and_fill(&rtnl_addr_ops, sk, result);
}
 
/**
 * Search address in cache
 * @arg cache           Address cache
 * @arg ifindex         Interface index of address
 * @arg addr            Local address part
 *
 * Searches address cache previously allocated with rtnl_addr_alloc_cache()
 * for an address with a matching local address.
 *
 * The reference counter is incremented before returning the address, therefore
 * the reference must be given back with rtnl_addr_put() after usage.
 *
 * @return Address object or NULL if no match was found.
 */
struct rtnl_addr *rtnl_addr_get(struct nl_cache *cache, int ifindex,
                                struct nl_addr *addr)
{
        struct rtnl_addr *a;
 
        if (cache->c_ops != &rtnl_addr_ops)
                return NULL;
 
        nl_list_for_each_entry(a, &cache->c_items, ce_list) {
                if (ifindex && a->a_ifindex != ifindex)
                        continue;
 
                if (a->ce_mask & ADDR_ATTR_LOCAL &&
                    !nl_addr_cmp(a->a_local, addr)) {
                        nl_object_get((struct nl_object *) a);
                        return a;
                }
        }
 
        return NULL;
}
 
/** @} */
 
static int build_addr_msg(struct rtnl_addr *tmpl, int cmd, int flags,
                          struct nl_msg **result)
{
        struct nl_msg *msg;
        struct ifaddrmsg am = {
                .ifa_family = tmpl->a_family,
                .ifa_index = tmpl->a_ifindex,
                .ifa_prefixlen = tmpl->a_prefixlen,
                .ifa_flags = tmpl->a_flags,
        };
 
        if (tmpl->ce_mask & ADDR_ATTR_SCOPE)
                am.ifa_scope = tmpl->a_scope;
        else {
                /* compatibility hack */
                if (tmpl->a_family == AF_INET &&
                    tmpl->ce_mask & ADDR_ATTR_LOCAL &&
                    *((char *) nl_addr_get_binary_addr(tmpl->a_local)) == 127)
                        am.ifa_scope = RT_SCOPE_HOST;
                else
                        am.ifa_scope = RT_SCOPE_UNIVERSE;
        }
 
        msg = nlmsg_alloc_simple(cmd, flags);
        if (!msg)
                return -NLE_NOMEM;
 
        if (nlmsg_append(msg, &am, sizeof(am), NLMSG_ALIGNTO) < 0)
                goto nla_put_failure;
 
        if (tmpl->ce_mask & ADDR_ATTR_LOCAL)
                NLA_PUT_ADDR(msg, IFA_LOCAL, tmpl->a_local);
 
        if (tmpl->ce_mask & ADDR_ATTR_PEER)
                NLA_PUT_ADDR(msg, IFA_ADDRESS, tmpl->a_peer);
        else if (tmpl->ce_mask & ADDR_ATTR_LOCAL)
                NLA_PUT_ADDR(msg, IFA_ADDRESS, tmpl->a_local);
 
        if (tmpl->ce_mask & ADDR_ATTR_LABEL)
                NLA_PUT_STRING(msg, IFA_LABEL, tmpl->a_label);
 
        if (tmpl->ce_mask & ADDR_ATTR_BROADCAST)
                NLA_PUT_ADDR(msg, IFA_BROADCAST, tmpl->a_bcast);
 
        if (tmpl->ce_mask & ADDR_ATTR_CACHEINFO) {
                struct ifa_cacheinfo ca = {
                        .ifa_valid = tmpl->a_cacheinfo.aci_valid,
                        .ifa_prefered = tmpl->a_cacheinfo.aci_prefered,
                };
 
                NLA_PUT(msg, IFA_CACHEINFO, sizeof(ca), &ca);
        }
 
        if (tmpl->a_flags & ~0xFF) {
                /* only set the IFA_FLAGS attribute, if they actually contain additional
                 * flags that are not already set to am.ifa_flags.
                 *
                 * Older kernels refuse RTM_NEWADDR and RTM_NEWROUTE messages with EINVAL
                 * if they contain unknown netlink attributes. See net/core/rtnetlink.c, which
                 * was fixed by kernel commit 661d2967b3f1b34eeaa7e212e7b9bbe8ee072b59.
                 *
                 * With this workaround, libnl will function correctly with older kernels,
                 * unless there is a new libnl user that wants to set these flags. In this
                 * case it's up to the user to workaround this issue. */
                NLA_PUT_U32(msg, IFA_FLAGS, tmpl->a_flags);
        }
 
        *result = msg;
        return 0;
 
nla_put_failure:
        nlmsg_free(msg);
        return -NLE_MSGSIZE;
}
 
/**
 * @name Addition
 * @{
 */
 
/**
 * Build netlink request message to request addition of new address
 * @arg addr            Address object representing the new address.
 * @arg flags           Additional netlink message flags.
 * @arg result          Pointer to store resulting message.
 *
 * Builds a new netlink message requesting the addition of a new
 * address. The netlink message header isn't fully equipped with
 * all relevant fields and must thus be sent out via nl_send_auto_complete()
 * or supplemented as needed.
 *
 * Minimal required attributes:
 *   - interface index (rtnl_addr_set_ifindex())
 *   - local address (rtnl_addr_set_local())
 *
 * The scope will default to universe except for loopback addresses in
 * which case a host scope is used if not specified otherwise.
 *
 * @note Free the memory after usage using nlmsg_free().
 *
 * @return 0 on success or a negative error code.
 */
int rtnl_addr_build_add_request(struct rtnl_addr *addr, int flags,
                                struct nl_msg **result)
{
        uint32_t required = ADDR_ATTR_IFINDEX | ADDR_ATTR_FAMILY |
                       ADDR_ATTR_PREFIXLEN | ADDR_ATTR_LOCAL;
 
        if ((addr->ce_mask & required) != required)
                return -NLE_MISSING_ATTR;
        
        return build_addr_msg(addr, RTM_NEWADDR, NLM_F_CREATE | flags, result);
}
 
/**
 * Request addition of new address
 * @arg sk              Netlink socket.
 * @arg addr            Address object representing the new address.
 * @arg flags           Additional netlink message flags.
 *
 * Builds a netlink message by calling rtnl_addr_build_add_request(),
 * sends the request to the kernel and waits for the next ACK to be
 * received and thus blocks until the request has been fullfilled.
 *
 * @see rtnl_addr_build_add_request()
 *
 * @return 0 on success or a negative error if an error occured.
 */
int rtnl_addr_add(struct nl_sock *sk, struct rtnl_addr *addr, int flags)
{
        struct nl_msg *msg;
        int err;
 
        if ((err = rtnl_addr_build_add_request(addr, flags, &msg)) < 0)
                return err;
 
        err = nl_send_auto_complete(sk, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;
 
        return wait_for_ack(sk);
}
 
/** @} */
 
/**
 * @name Deletion
 * @{
 */
 
/**
 * Build a netlink request message to request deletion of an address
 * @arg addr            Address object to be deleteted.
 * @arg flags           Additional netlink message flags.
 * @arg result          Pointer to store resulting message.
 *
 * Builds a new netlink message requesting a deletion of an address.
 * The netlink message header isn't fully equipped with all relevant
 * fields and must thus be sent out via nl_send_auto_complete()
 * or supplemented as needed.
 *
 * Minimal required attributes:
 *   - interface index (rtnl_addr_set_ifindex())
 *   - address family (rtnl_addr_set_family())
 *
 * Optional attributes:
 *   - local address (rtnl_addr_set_local())
 *   - label (rtnl_addr_set_label(), IPv4/DECnet only)
 *   - peer address (rtnl_addr_set_peer(), IPv4 only)
 *
 * @note Free the memory after usage using nlmsg_free().
 *
 * @return 0 on success or a negative error code.
 */
int rtnl_addr_build_delete_request(struct rtnl_addr *addr, int flags,
                                   struct nl_msg **result)
{
        uint32_t required = ADDR_ATTR_IFINDEX | ADDR_ATTR_FAMILY;
 
        if ((addr->ce_mask & required) != required)
                return -NLE_MISSING_ATTR;
 
        return build_addr_msg(addr, RTM_DELADDR, flags, result);
}
 
/**
 * Request deletion of an address
 * @arg sk              Netlink socket.
 * @arg addr            Address object to be deleted.
 * @arg flags           Additional netlink message flags.
 *
 * Builds a netlink message by calling rtnl_addr_build_delete_request(),
 * sends the request to the kernel and waits for the next ACK to be
 * received and thus blocks until the request has been fullfilled.
 *
 * @see rtnl_addr_build_delete_request();
 *
 * @return 0 on success or a negative error if an error occured.
 */
int rtnl_addr_delete(struct nl_sock *sk, struct rtnl_addr *addr, int flags)
{
        struct nl_msg *msg;
        int err;
 
        if ((err = rtnl_addr_build_delete_request(addr, flags, &msg)) < 0)
                return err;
 
        err = nl_send_auto_complete(sk, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;
 
        return wait_for_ack(sk);
}
 
/** @} */
 
/**
 * @name Attributes
 * @{
 */
 
int rtnl_addr_set_label(struct rtnl_addr *addr, const char *label)
{
        if (strlen(label) > sizeof(addr->a_label) - 1)
                return -NLE_RANGE;
 
        strcpy(addr->a_label, label);
        addr->ce_mask |= ADDR_ATTR_LABEL;
 
        return 0;
}
 
char *rtnl_addr_get_label(struct rtnl_addr *addr)
{
        if (addr->ce_mask & ADDR_ATTR_LABEL)
                return addr->a_label;
        else
                return NULL;
}
 
void rtnl_addr_set_ifindex(struct rtnl_addr *addr, int ifindex)
{
        addr->a_ifindex = ifindex;
        addr->ce_mask |= ADDR_ATTR_IFINDEX;
}
 
int rtnl_addr_get_ifindex(struct rtnl_addr *addr)
{
        return addr->a_ifindex;
}
 
void rtnl_addr_set_link(struct rtnl_addr *addr, struct rtnl_link *link)
{
        rtnl_link_put(addr->a_link);
 
        if (!link)
                return;
 
        nl_object_get(OBJ_CAST(link));
        addr->a_link = link;
        addr->a_ifindex = link->l_index;
        addr->ce_mask |= ADDR_ATTR_IFINDEX;
}
 
struct rtnl_link *rtnl_addr_get_link(struct rtnl_addr *addr)
{
        if (addr->a_link) {
                nl_object_get(OBJ_CAST(addr->a_link));
                return addr->a_link;
        }
 
        return NULL;
}
 
void rtnl_addr_set_family(struct rtnl_addr *addr, int family)
{
        addr->a_family = family;
        addr->ce_mask |= ADDR_ATTR_FAMILY;
}
 
int rtnl_addr_get_family(struct rtnl_addr *addr)
{
        return addr->a_family;
}
 
/**
 * Set the prefix length / netmask
 * @arg addr            Address
 * @arg prefixlen       Length of prefix (netmask)
 *
 * Modifies the length of the prefix. If the address object contains a peer
 * address the prefix length will apply to it, otherwise the prefix length
 * will apply to the local address of the address.
 *
 * If the address object contains a peer or local address the corresponding
 * `struct nl_addr` will be updated with the new prefix length.
 *
 * @note Specifying a length of 0 will remove the prefix length alltogether.
 *
 * @see rtnl_addr_get_prefixlen()
 */
void rtnl_addr_set_prefixlen(struct rtnl_addr *addr, int prefixlen)
{
        addr->a_prefixlen = prefixlen;
 
        if (prefixlen)
                addr->ce_mask |= ADDR_ATTR_PREFIXLEN;
        else
                addr->ce_mask &= ~ADDR_ATTR_PREFIXLEN;
 
        /*
         * The prefix length always applies to the peer address if
         * a peer address is present.
         */
        if (addr->a_peer)
                nl_addr_set_prefixlen(addr->a_peer, prefixlen);
        else if (addr->a_local)
                nl_addr_set_prefixlen(addr->a_local, prefixlen);
}
 
int rtnl_addr_get_prefixlen(struct rtnl_addr *addr)
{
        return addr->a_prefixlen;
}
 
void rtnl_addr_set_scope(struct rtnl_addr *addr, int scope)
{
        addr->a_scope = scope;
        addr->ce_mask |= ADDR_ATTR_SCOPE;
}
 
int rtnl_addr_get_scope(struct rtnl_addr *addr)
{
        return addr->a_scope;
}
 
void rtnl_addr_set_flags(struct rtnl_addr *addr, unsigned int flags)
{
        addr->a_flag_mask |= flags;
        addr->a_flags |= flags;
        addr->ce_mask |= ADDR_ATTR_FLAGS;
}
 
void rtnl_addr_unset_flags(struct rtnl_addr *addr, unsigned int flags)
{
        addr->a_flag_mask |= flags;
        addr->a_flags &= ~flags;
        addr->ce_mask |= ADDR_ATTR_FLAGS;
}
 
unsigned int rtnl_addr_get_flags(struct rtnl_addr *addr)
{
        return addr->a_flags;
}
 
static inline int __assign_addr(struct rtnl_addr *addr, struct nl_addr **pos,
                                struct nl_addr *new, int flag)
{
        if (new) {
                if (addr->ce_mask & ADDR_ATTR_FAMILY) {
                        if (new->a_family != addr->a_family)
                                return -NLE_AF_MISMATCH;
                } else
                        addr->a_family = new->a_family;
 
                if (*pos)
                        nl_addr_put(*pos);
 
                *pos = nl_addr_get(new);
                addr->ce_mask |= (flag | ADDR_ATTR_FAMILY);
        } else {
                if (*pos)
                        nl_addr_put(*pos);
 
                *pos = NULL;
                addr->ce_mask &= ~flag;
        }
 
        return 0;
}
 
int rtnl_addr_set_local(struct rtnl_addr *addr, struct nl_addr *local)
{
        int err;
 
        /* Prohibit local address with prefix length if peer address is present */
        if ((addr->ce_mask & ADDR_ATTR_PEER) && local &&
            nl_addr_get_prefixlen(local))
                return -NLE_INVAL;
 
        err = __assign_addr(addr, &addr->a_local, local, ADDR_ATTR_LOCAL);
        if (err < 0)
                return err;
 
        /* Never overwrite the prefix length if a peer address is present */
        if (!(addr->ce_mask & ADDR_ATTR_PEER))
                rtnl_addr_set_prefixlen(addr, local ? nl_addr_get_prefixlen(local) : 0);
 
        return 0;
}
 
struct nl_addr *rtnl_addr_get_local(struct rtnl_addr *addr)
{
        return addr->a_local;
}
 
int rtnl_addr_set_peer(struct rtnl_addr *addr, struct nl_addr *peer)
{
        int err;
 
        if (peer && peer->a_family != AF_INET)
                return -NLE_AF_NOSUPPORT;
 
        err = __assign_addr(addr, &addr->a_peer, peer, ADDR_ATTR_PEER);
        if (err < 0)
                return err;
 
        rtnl_addr_set_prefixlen(addr, peer ? nl_addr_get_prefixlen(peer) : 0);
 
        return 0;
}
 
struct nl_addr *rtnl_addr_get_peer(struct rtnl_addr *addr)
{
        return addr->a_peer;
}
 
int rtnl_addr_set_broadcast(struct rtnl_addr *addr, struct nl_addr *bcast)
{
        if (bcast && bcast->a_family != AF_INET)
                return -NLE_AF_NOSUPPORT;
 
        return __assign_addr(addr, &addr->a_bcast, bcast, ADDR_ATTR_BROADCAST);
}
 
struct nl_addr *rtnl_addr_get_broadcast(struct rtnl_addr *addr)
{
        return addr->a_bcast;
}
 
int rtnl_addr_set_multicast(struct rtnl_addr *addr, struct nl_addr *multicast)
{
        if (multicast && multicast->a_family != AF_INET6)
                return -NLE_AF_NOSUPPORT;
 
        return __assign_addr(addr, &addr->a_multicast, multicast,
                             ADDR_ATTR_MULTICAST);
}
 
struct nl_addr *rtnl_addr_get_multicast(struct rtnl_addr *addr)
{
        return addr->a_multicast;
}
 
int rtnl_addr_set_anycast(struct rtnl_addr *addr, struct nl_addr *anycast)
{
        if (anycast && anycast->a_family != AF_INET6)
                return -NLE_AF_NOSUPPORT;
 
        return __assign_addr(addr, &addr->a_anycast, anycast,
                             ADDR_ATTR_ANYCAST);
}
 
struct nl_addr *rtnl_addr_get_anycast(struct rtnl_addr *addr)
{
        return addr->a_anycast;
}
 
uint32_t rtnl_addr_get_valid_lifetime(struct rtnl_addr *addr)
{
        if (addr->ce_mask & ADDR_ATTR_CACHEINFO)
                return addr->a_cacheinfo.aci_valid;
        else
                return 0xFFFFFFFFU;
}
 
void rtnl_addr_set_valid_lifetime(struct rtnl_addr *addr, uint32_t lifetime)
{
        addr->a_cacheinfo.aci_valid = lifetime;
        addr->ce_mask |= ADDR_ATTR_CACHEINFO;
}
 
uint32_t rtnl_addr_get_preferred_lifetime(struct rtnl_addr *addr)
{
        if (addr->ce_mask & ADDR_ATTR_CACHEINFO)
                return addr->a_cacheinfo.aci_prefered;
        else
                return 0xFFFFFFFFU;
}
 
void rtnl_addr_set_preferred_lifetime(struct rtnl_addr *addr, uint32_t lifetime)
{
        addr->a_cacheinfo.aci_prefered = lifetime;
        addr->ce_mask |= ADDR_ATTR_CACHEINFO;
}
 
uint32_t rtnl_addr_get_create_time(struct rtnl_addr *addr)
{
        return addr->a_cacheinfo.aci_cstamp;
}
 
uint32_t rtnl_addr_get_last_update_time(struct rtnl_addr *addr)
{
        return addr->a_cacheinfo.aci_tstamp;
}
 
/** @} */
 
/**
 * @name Flags Translations
 * @{
 */
 
static const struct trans_tbl addr_flags[] = {
        __ADD(IFA_F_SECONDARY, secondary),
        __ADD(IFA_F_NODAD, nodad),
        __ADD(IFA_F_OPTIMISTIC, optimistic),
        __ADD(IFA_F_DADFAILED, dadfailed),
        __ADD(IFA_F_HOMEADDRESS, homeaddress),
        __ADD(IFA_F_DEPRECATED, deprecated),
        __ADD(IFA_F_TENTATIVE, tentative),
        __ADD(IFA_F_PERMANENT, permanent),
        __ADD(IFA_F_MANAGETEMPADDR, mngtmpaddr),
        __ADD(IFA_F_NOPREFIXROUTE, noprefixroute),
};
 
char *rtnl_addr_flags2str(int flags, char *buf, size_t size)
{
        return __flags2str(flags, buf, size, addr_flags,
                           ARRAY_SIZE(addr_flags));
}
 
int rtnl_addr_str2flags(const char *name)
{
        return __str2flags(name, addr_flags, ARRAY_SIZE(addr_flags));
}
 
/** @} */
 
static struct nl_object_ops addr_obj_ops = {
        .oo_name                = "route/addr",
        .oo_size                = sizeof(struct rtnl_addr),
        .oo_constructor         = addr_constructor,
        .oo_free_data           = addr_free_data,
        .oo_clone               = addr_clone,
        .oo_dump = {
            [NL_DUMP_LINE]      = addr_dump_line,
            [NL_DUMP_DETAILS]   = addr_dump_details,
            [NL_DUMP_STATS]     = addr_dump_stats,
        },
        .oo_compare             = addr_compare,
        .oo_attrs2str           = addr_attrs2str,
        .oo_id_attrs_get        = addr_id_attrs_get,
        .oo_id_attrs            = (ADDR_ATTR_FAMILY | ADDR_ATTR_IFINDEX |
                                   ADDR_ATTR_LOCAL | ADDR_ATTR_PREFIXLEN),
};
 
static struct nl_af_group addr_groups[] = {
        { AF_INET,      RTNLGRP_IPV4_IFADDR },
        { AF_INET6,     RTNLGRP_IPV6_IFADDR },
        { END_OF_GROUP_LIST },
};
 
static struct nl_cache_ops rtnl_addr_ops = {
        .co_name                = "route/addr",
        .co_hdrsize             = sizeof(struct ifaddrmsg),
        .co_msgtypes            = {
                                        { RTM_NEWADDR, NL_ACT_NEW, "new" },
                                        { RTM_DELADDR, NL_ACT_DEL, "del" },
                                        { RTM_GETADDR, NL_ACT_GET, "get" },
                                        END_OF_MSGTYPES_LIST,
                                  },
        .co_protocol            = NETLINK_ROUTE,
        .co_groups              = addr_groups,
        .co_request_update      = addr_request_update,
        .co_msg_parser          = addr_msg_parser,
        .co_obj_ops             = &addr_obj_ops,
};
 
static void __init addr_init(void)
{
        nl_cache_mngt_register(&rtnl_addr_ops);
}
 
static void __exit addr_exit(void)
{
        nl_cache_mngt_unregister(&rtnl_addr_ops);
}
 
/** @} */