xref: /aosp_15_r20/external/libnl/lib/route/cls/u32.c (revision 4dc78e53d49367fa8e61b07018507c90983a077d)

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * Copyright (c) 2003-2013 Thomas Graf <[email protected]>
 * Copyright (c) 2005-2006 Petr Gotthard <[email protected]>
 * Copyright (c) 2005-2006 Siemens AG Oesterreich
 */

/**
 * @ingroup cls
 * @defgroup cls_u32 Universal 32-bit Classifier
 *
 * @{
 */

#include "nl-default.h"

#include <netlink/netlink.h>
#include <netlink/attr.h>
#include <netlink/utils.h>
#include <netlink/route/classifier.h>
#include <netlink/route/cls/u32.h>
#include <netlink/route/action.h>

#include "tc-api.h"
#include "nl-aux-route/nl-route.h"

/** @cond SKIP */
struct rtnl_u32 {
	uint32_t cu_divisor;
	uint32_t cu_hash;
	uint32_t cu_classid;
	uint32_t cu_link;
	struct nl_data *cu_pcnt;
	struct nl_data *cu_selector;
	struct nl_data *cu_mark;
	struct rtnl_act *cu_act;
	struct nl_data *cu_police;
	char cu_indev[IFNAMSIZ];
	int cu_mask;
};

#define U32_ATTR_DIVISOR      0x001
#define U32_ATTR_HASH         0x002
#define U32_ATTR_CLASSID      0x004
#define U32_ATTR_LINK         0x008
#define U32_ATTR_PCNT         0x010
#define U32_ATTR_SELECTOR     0x020
#define U32_ATTR_ACTION       0x040
#define U32_ATTR_POLICE       0x080
#define U32_ATTR_INDEV        0x100
#define U32_ATTR_MARK	      0x200
/** @endcond */

static inline struct tc_u32_sel *u32_selector(struct rtnl_u32 *u)
{
	return (struct tc_u32_sel *) u->cu_selector->d_data;
}

static inline struct tc_u32_sel *u32_selector_alloc(struct rtnl_u32 *u)
{
	if (!u->cu_selector)
		u->cu_selector = nl_data_alloc(NULL, sizeof(struct tc_u32_sel));

	return u32_selector(u);
}

static inline struct tc_u32_mark *u32_mark_alloc(struct rtnl_u32 *u)
{
	if (!u->cu_mark)
		u->cu_mark = nl_data_alloc(NULL, sizeof(struct tc_u32_mark));

	return (struct tc_u32_mark *) u->cu_mark->d_data;
}

static struct nla_policy u32_policy[TCA_U32_MAX+1] = {
	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
	[TCA_U32_HASH]		= { .type = NLA_U32 },
	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
	[TCA_U32_LINK]		= { .type = NLA_U32 },
	[TCA_U32_INDEV]		= { .type = NLA_STRING,
				    .maxlen = IFNAMSIZ },
	[TCA_U32_SEL]		= { .minlen = sizeof(struct tc_u32_sel) },
	[TCA_U32_PCNT]		= { .minlen = sizeof(struct tc_u32_pcnt) },
	[TCA_U32_MARK]		= { .minlen = sizeof(struct tc_u32_mark) }
};

static int u32_msg_parser(struct rtnl_tc *tc, void *data)
{
	struct rtnl_u32 *u = data;
	struct nlattr *tb[TCA_U32_MAX + 1];
	int err;

	err = tca_parse(tb, TCA_U32_MAX, tc, u32_policy);
	if (err < 0)
		return err;

	if (tb[TCA_U32_DIVISOR]) {
		u->cu_divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
		u->cu_mask |= U32_ATTR_DIVISOR;
	}

	if (tb[TCA_U32_SEL]) {
		u->cu_selector = nl_data_alloc_attr(tb[TCA_U32_SEL]);
		if (!u->cu_selector)
			goto errout_nomem;
		u->cu_mask |= U32_ATTR_SELECTOR;
	}

	if (tb[TCA_U32_MARK]) {
		u->cu_mark = nl_data_alloc_attr(tb[TCA_U32_MARK]);
		if (!u->cu_mark)
			goto errout_nomem;
		u->cu_mask |= U32_ATTR_MARK;
	}

	if (tb[TCA_U32_HASH]) {
		u->cu_hash = nla_get_u32(tb[TCA_U32_HASH]);
		u->cu_mask |= U32_ATTR_HASH;
	}

	if (tb[TCA_U32_CLASSID]) {
		u->cu_classid = nla_get_u32(tb[TCA_U32_CLASSID]);
		u->cu_mask |= U32_ATTR_CLASSID;
	}

	if (tb[TCA_U32_LINK]) {
		u->cu_link = nla_get_u32(tb[TCA_U32_LINK]);
		u->cu_mask |= U32_ATTR_LINK;
	}

	if (tb[TCA_U32_ACT]) {
		u->cu_mask |= U32_ATTR_ACTION;
		err = rtnl_act_parse(&u->cu_act, tb[TCA_U32_ACT]);
		if (err < 0)
			return err;
	}

	if (tb[TCA_U32_POLICE]) {
		u->cu_police = nl_data_alloc_attr(tb[TCA_U32_POLICE]);
		if (!u->cu_police)
			goto errout_nomem;
		u->cu_mask |= U32_ATTR_POLICE;
	}

	if (tb[TCA_U32_PCNT]) {
		struct tc_u32_sel *sel;
		size_t pcnt_size;

		if (!tb[TCA_U32_SEL]) {
			err = -NLE_MISSING_ATTR;
			goto errout;
		}

		sel = u->cu_selector->d_data;
		pcnt_size = sizeof(struct tc_u32_pcnt) +
				(sel->nkeys * sizeof(uint64_t));
		if (_nla_len(tb[TCA_U32_PCNT]) < pcnt_size) {
			err = -NLE_INVAL;
			goto errout;
		}

		u->cu_pcnt = nl_data_alloc_attr(tb[TCA_U32_PCNT]);
		if (!u->cu_pcnt)
			goto errout_nomem;
		u->cu_mask |= U32_ATTR_PCNT;
	}

	if (tb[TCA_U32_INDEV]) {
		nla_strlcpy(u->cu_indev, tb[TCA_U32_INDEV], IFNAMSIZ);
		u->cu_mask |= U32_ATTR_INDEV;
	}

	return 0;

errout_nomem:
	err = -NLE_NOMEM;
errout:
	return err;
}

static void u32_free_data(struct rtnl_tc *tc, void *data)
{
	struct rtnl_u32 *u = data;

	if (u->cu_act)
		rtnl_act_put_all(&u->cu_act);
	nl_data_free(u->cu_mark);
	nl_data_free(u->cu_selector);
	nl_data_free(u->cu_police);
	nl_data_free(u->cu_pcnt);
}

static int u32_clone(void *_dst, void *_src)
{
	struct rtnl_u32 *dst = _dst, *src = _src;
	_nl_auto_nl_data struct nl_data *selector = NULL;
	_nl_auto_nl_data struct nl_data *mark = NULL;
	_nl_auto_nl_data struct nl_data *police = NULL;
	_nl_auto_nl_data struct nl_data *pcnt = NULL;
	_nl_auto_nl_data struct nl_data *opts = NULL;
	_nl_auto_nl_data struct nl_data *xstats = NULL;
	_nl_auto_nl_data struct nl_data *subdata = NULL;
	_nl_auto_rtnl_act struct rtnl_act *act = NULL;

	dst->cu_pcnt = NULL;
	dst->cu_selector = NULL;
	dst->cu_mark = NULL;
	dst->cu_act = NULL;
	dst->cu_police = NULL;

	if (src->cu_selector) {
		if (!(selector = nl_data_clone(src->cu_selector)))
			return -NLE_NOMEM;
	}

	if (src->cu_mark) {
		if (!(mark = nl_data_clone(src->cu_mark)))
			return -NLE_NOMEM;
	}

	if (src->cu_act) {
		if (!(act = rtnl_act_alloc()))
			return -NLE_NOMEM;

		if (src->cu_act->c_opts) {
			if (!(opts = nl_data_clone(src->cu_act->c_opts)))
				return -NLE_NOMEM;
		}

		if (src->cu_act->c_xstats) {
			if (!(xstats = nl_data_clone(src->cu_act->c_xstats)))
				return -NLE_NOMEM;
		}

		if (src->cu_act->c_subdata) {
			if (!(subdata = nl_data_clone(src->cu_act->c_subdata)))
				return -NLE_NOMEM;
		}
	}

	if (src->cu_police) {
		if (!(police = nl_data_clone(src->cu_police)))
			return -NLE_NOMEM;
	}

	if (src->cu_pcnt) {
		if (!(pcnt = nl_data_clone(src->cu_pcnt)))
			return -NLE_NOMEM;
	}

	/* we've passed the critical point and its safe to proceed */

	if (selector)
		dst->cu_selector = _nl_steal_pointer(&selector);

	if (mark)
		dst->cu_mark = _nl_steal_pointer(&mark);

	if (police)
		dst->cu_police = _nl_steal_pointer(&police);

	if (pcnt)
		dst->cu_pcnt = _nl_steal_pointer(&pcnt);

	if (act) {
		dst->cu_act = _nl_steal_pointer(&act);

		/* action nl list next and prev pointers must be updated */
		nl_init_list_head(&dst->cu_act->ce_list);

		if (opts)
			dst->cu_act->c_opts = _nl_steal_pointer(&opts);

		if (xstats)
			dst->cu_act->c_xstats = _nl_steal_pointer(&xstats);

		if (subdata)
			dst->cu_act->c_subdata = _nl_steal_pointer(&subdata);

		if (dst->cu_act->c_link) {
			nl_object_get(OBJ_CAST(dst->cu_act->c_link));
		}

		dst->cu_act->a_next = NULL;   /* Only clone first in chain */
	}

	return 0;
}

static void u32_dump_line(struct rtnl_tc *tc, void *data,
			  struct nl_dump_params *p)
{
	struct rtnl_u32 *u = data;
	char buf[32];

	if (!u)
		return;

	if (u->cu_mask & U32_ATTR_DIVISOR)
		nl_dump(p, " divisor %u", u->cu_divisor);
	else if (u->cu_mask & U32_ATTR_CLASSID)
		nl_dump(p, " target %s",
			rtnl_tc_handle2str(u->cu_classid, buf, sizeof(buf)));
}

static void print_selector(struct nl_dump_params *p, struct tc_u32_sel *sel,
			   struct rtnl_u32 *u)
{
	int i;
	struct tc_u32_key *key;

	if (sel->hmask || sel->hoff) {
		/* I guess this will never be used since the kernel only
		 * exports the selector if no divisor is set but hash offset
		 * and hash mask make only sense in hash filters with divisor
		 * set */
		nl_dump(p, " hash at %u & 0x%x", sel->hoff, sel->hmask);
	}

	if (sel->flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
		nl_dump(p, " offset at %u", sel->off);

		if (sel->flags & TC_U32_VAROFFSET)
			nl_dump(p, " variable (at %u & 0x%x) >> %u",
				sel->offoff, ntohs(sel->offmask), sel->offshift);
	}

	if (sel->flags) {
		int flags = sel->flags;
		nl_dump(p, " <");

#define PRINT_FLAG(f) if (flags & TC_U32_##f) { \
	flags &= ~TC_U32_##f; nl_dump(p, #f "%s", flags ? "," : ""); }

		PRINT_FLAG(TERMINAL);
		PRINT_FLAG(OFFSET);
		PRINT_FLAG(VAROFFSET);
		PRINT_FLAG(EAT);
#undef PRINT_FLAG

		nl_dump(p, ">");
	}


	for (i = 0; i < sel->nkeys; i++) {
		key = &sel->keys[i];

		nl_dump(p, "\n");
		nl_dump_line(p, "      match key at %s%u ",
			key->offmask ? "nexthdr+" : "", key->off);

		if (key->offmask)
			nl_dump(p, "[0x%u] ", key->offmask);

		nl_dump(p, "& 0x%08x == 0x%08x", ntohl(key->mask), ntohl(key->val));

		if (p->dp_type == NL_DUMP_STATS &&
		    (u->cu_mask & U32_ATTR_PCNT)) {
			struct tc_u32_pcnt *pcnt = u->cu_pcnt->d_data;

			nl_dump(p, " successful %llu",
				(long long unsigned)pcnt->kcnts[i]);
		}
	}
}

static void u32_dump_details(struct rtnl_tc *tc, void *data,
			     struct nl_dump_params *p)
{
	struct rtnl_u32 *u = data;
	struct tc_u32_sel *s = NULL;
	struct tc_u32_mark *m;

	if (!u)
		return;

	if (!(u->cu_mask & U32_ATTR_SELECTOR)) {
		nl_dump(p, "no-selector");
	} else {
		s = u->cu_selector->d_data;
		nl_dump(p, "nkeys %u", s->nkeys);
	}

	if (!(u->cu_mask & U32_ATTR_MARK)) {
		nl_dump(p, " no-mark");
	} else {
		m = u->cu_mark->d_data;
		nl_dump(p, " mark 0x%u 0x%u", m->val, m->mask);
	}

	if (u->cu_mask & U32_ATTR_HASH)
		nl_dump(p, " ht key 0x%x hash 0x%u",
			TC_U32_USERHTID(u->cu_hash), TC_U32_HASH(u->cu_hash));

	if (u->cu_mask & U32_ATTR_LINK)
		nl_dump(p, " link %u", u->cu_link);

	if (u->cu_mask & U32_ATTR_INDEV)
		nl_dump(p, " indev %s", u->cu_indev);

	if (u->cu_mask & U32_ATTR_SELECTOR)
		print_selector(p, s, u);

	nl_dump(p, "\n");
}

static void u32_dump_stats(struct rtnl_tc *tc, void *data,
			   struct nl_dump_params *p)
{
	struct rtnl_u32 *u = data;

	if (!u)
		return;

	if (u->cu_mask & U32_ATTR_PCNT) {
		struct tc_u32_pcnt *pc = u->cu_pcnt->d_data;

		nl_dump(p, "\n");
		nl_dump_line(p, "    hit %8llu count %8llu\n",
			     (long long unsigned)pc->rhit,
			     (long long unsigned)pc->rcnt);
	}
}

static int u32_msg_fill(struct rtnl_tc *tc, void *data, struct nl_msg *msg)
{
	struct rtnl_u32 *u = data;

	if (!u)
		return 0;

	if (u->cu_mask & U32_ATTR_DIVISOR)
		NLA_PUT_U32(msg, TCA_U32_DIVISOR, u->cu_divisor);

	if (u->cu_mask & U32_ATTR_HASH)
		NLA_PUT_U32(msg, TCA_U32_HASH, u->cu_hash);

	if (u->cu_mask & U32_ATTR_CLASSID)
		NLA_PUT_U32(msg, TCA_U32_CLASSID, u->cu_classid);

	if (u->cu_mask & U32_ATTR_LINK)
		NLA_PUT_U32(msg, TCA_U32_LINK, u->cu_link);

	if (u->cu_mask & U32_ATTR_SELECTOR)
		NLA_PUT_DATA(msg, TCA_U32_SEL, u->cu_selector);

	if (u->cu_mask & U32_ATTR_MARK)
		NLA_PUT_DATA(msg, TCA_U32_MARK, u->cu_mark);

	if (u->cu_mask & U32_ATTR_ACTION) {
		int err;

		err = rtnl_act_fill(msg, TCA_U32_ACT, u->cu_act);
		if (err < 0)
			return err;
	}

	if (u->cu_mask & U32_ATTR_POLICE)
		NLA_PUT_DATA(msg, TCA_U32_POLICE, u->cu_police);

	if (u->cu_mask & U32_ATTR_INDEV)
		NLA_PUT_STRING(msg, TCA_U32_INDEV, u->cu_indev);

	return 0;

nla_put_failure:
	return -NLE_NOMEM;
}

/**
 * @name Attribute Modifications
 * @{
 */

void rtnl_u32_set_handle(struct rtnl_cls *cls, int htid, int hash,
			 int nodeid)
{
	uint32_t handle = (htid << 20) | (hash << 12) | nodeid;

	rtnl_tc_set_handle((struct rtnl_tc *) cls, handle );
}

int rtnl_u32_set_classid(struct rtnl_cls *cls, uint32_t classid)
{
	struct rtnl_u32 *u;

	if (!(u = rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	u->cu_classid = classid;
	u->cu_mask |= U32_ATTR_CLASSID;

	return 0;
}

int rtnl_u32_get_classid(struct rtnl_cls *cls, uint32_t *classid)
{
	struct rtnl_u32 *u;

	if (!(u = rtnl_tc_data_peek(TC_CAST(cls))))
		return -NLE_INVAL;

	if (!(u->cu_mask & U32_ATTR_CLASSID))
		return -NLE_INVAL;

	*classid = u->cu_classid;
	return 0;
}

int rtnl_u32_set_divisor(struct rtnl_cls *cls, uint32_t divisor)
{
	struct rtnl_u32 *u;

	if (!(u = (struct rtnl_u32 *) rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	u->cu_divisor = divisor;
	u->cu_mask |= U32_ATTR_DIVISOR;
	return 0;
}

int rtnl_u32_set_link(struct rtnl_cls *cls, uint32_t link)
{
	struct rtnl_u32 *u;

	if (!(u = (struct rtnl_u32 *) rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	u->cu_link = link;
	u->cu_mask |= U32_ATTR_LINK;
	return 0;
}

int rtnl_u32_set_hashtable(struct rtnl_cls *cls, uint32_t ht)
{
	struct rtnl_u32 *u;

	if (!(u = (struct rtnl_u32 *) rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	u->cu_hash = ht;
	u->cu_mask |= U32_ATTR_HASH;
	return 0;
}

int rtnl_u32_set_hashmask(struct rtnl_cls *cls, uint32_t hashmask, uint32_t offset)
{
	struct rtnl_u32 *u;
	struct tc_u32_sel *sel;

	hashmask = htonl(hashmask);

	if (!(u = (struct rtnl_u32 *) rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	sel = u32_selector_alloc(u);
	if (!sel)
		return -NLE_NOMEM;

	sel->hmask = hashmask;
	sel->hoff = offset;
	return 0;
}

int rtnl_u32_set_selector(struct rtnl_cls *cls, int offoff, uint32_t offmask, char offshift, uint16_t off, char flags)
{
	struct rtnl_u32 *u;
	struct tc_u32_sel *sel;

	offmask = ntohs(offmask);

	if (!(u = (struct rtnl_u32 *) rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	sel = u32_selector_alloc(u);
	if (!sel)
		return -NLE_NOMEM;

	sel->offoff = offoff;
	sel->offmask = offmask;
	sel->offshift = offshift;
	sel->flags |= TC_U32_VAROFFSET;
	sel->off = off;
	sel->flags |= flags;
	return 0;
}

int rtnl_u32_set_cls_terminal(struct rtnl_cls *cls)
{
	struct rtnl_u32 *u;
	struct tc_u32_sel *sel;

	if (!(u = (struct rtnl_u32 *) rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	sel = u32_selector_alloc(u);
	if (!sel)
		return -NLE_NOMEM;

	sel->flags |= TC_U32_TERMINAL;
	return 0;
}

int rtnl_u32_add_action(struct rtnl_cls *cls, struct rtnl_act *act)
{
	struct rtnl_u32 *u;
	int err;

	if (!act)
		return 0;

	if (!(u = rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	if ((err = _rtnl_act_append_get(&u->cu_act, act)) < 0)
		return err;

	u->cu_mask |= U32_ATTR_ACTION;
	return 0;
}

struct rtnl_act* rtnl_u32_get_action(struct rtnl_cls *cls)
{
    struct rtnl_u32 *u;

    if (!(u = rtnl_tc_data_peek(TC_CAST(cls))))
        return NULL;

    if (!(u->cu_mask & U32_ATTR_ACTION))
        return NULL;

    return u->cu_act;
}

int rtnl_u32_del_action(struct rtnl_cls *cls, struct rtnl_act *act)
{
	struct rtnl_u32 *u;
	int ret;

	if (!act)
		return 0;

	if (!(u = rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	if (!(u->cu_mask & U32_ATTR_ACTION))
		return -NLE_INVAL;

	ret = rtnl_act_remove(&u->cu_act, act);
	if (ret)
		return ret;

	if (!u->cu_act)
		u->cu_mask &= ~U32_ATTR_ACTION;
	rtnl_act_put(act);
	return 0;
}
/** @} */

/**
 * @name Selector Modifications
 * @{
 */

int rtnl_u32_set_flags(struct rtnl_cls *cls, int flags)
{
	struct tc_u32_sel *sel;
	struct rtnl_u32 *u;

	if (!(u = rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	sel = u32_selector_alloc(u);
	if (!sel)
		return -NLE_NOMEM;

	sel->flags |= flags;
	u->cu_mask |= U32_ATTR_SELECTOR;

	return 0;
}

/**
 * Append new 32-bit key to the selector
 *
 * @arg cls	classifier to be modifier
 * @arg val	value to be matched (network byte-order)
 * @arg mask	mask to be applied before matching (network byte-order)
 * @arg off	offset, in bytes, to start matching
 * @arg offmask	offset mask
 *
 * General selectors define the pattern, mask and offset the pattern will be
 * matched to the packet contents. Using the general selectors you can match
 * virtually any single bit in the IP (or upper layer) header.
 *
*/
int rtnl_u32_add_key(struct rtnl_cls *cls, uint32_t val, uint32_t mask,
		     int off, int offmask)
{
	struct tc_u32_sel *sel;
	struct rtnl_u32 *u;
	int err;

	if (!(u = rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	sel = u32_selector_alloc(u);
	if (!sel)
		return -NLE_NOMEM;

	if (sel->nkeys == UCHAR_MAX)
		return -NLE_NOMEM;

	err = nl_data_append(u->cu_selector, NULL, sizeof(struct tc_u32_key));
	if (err < 0)
		return err;

	/* the selector might have been moved by realloc */
	sel = u32_selector(u);

	sel->keys[sel->nkeys].mask = mask;
	sel->keys[sel->nkeys].val = val & mask;
	sel->keys[sel->nkeys].off = off;
	sel->keys[sel->nkeys].offmask = offmask;
	sel->nkeys++;
	u->cu_mask |= U32_ATTR_SELECTOR;

	return 0;
}

int rtnl_u32_add_mark(struct rtnl_cls *cls, uint32_t val, uint32_t mask)
{
	struct tc_u32_mark *mark;
	struct rtnl_u32 *u;

	if (!(u = rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	mark = u32_mark_alloc(u);
	if (!mark)
		return -NLE_NOMEM;

	mark->mask = mask;
	mark->val = val;

	u->cu_mask |= U32_ATTR_MARK;

	return 0;
}

int rtnl_u32_del_mark(struct rtnl_cls *cls)
{
	struct rtnl_u32 *u;

	if (!(u = rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	if (!(u->cu_mask))
		return -NLE_INVAL;

	if (!(u->cu_mask & U32_ATTR_MARK))
		return -NLE_INVAL;

	nl_data_free(u->cu_mark);
	u->cu_mark = NULL;
	u->cu_mask &= ~U32_ATTR_MARK;

	return 0;
}

/**
 * Get the 32-bit key from the selector
 *
 * @arg cls	classifier to be retrieve
 * @arg index	the index of the array of keys, start with 0
 * @arg val	pointer to store value after masked (network byte-order)
 * @arg mask	pointer to store the mask (network byte-order)
 * @arg off	pointer to store the offset
 * @arg offmask	pointer to store offset mask
 *
*/
int rtnl_u32_get_key(struct rtnl_cls *cls, uint8_t index,
		     uint32_t *val, uint32_t *mask, int *off, int *offmask)
{
	struct tc_u32_sel *sel;
	struct rtnl_u32 *u;

	if (!(u = rtnl_tc_data(TC_CAST(cls))))
		return -NLE_NOMEM;

	if (!(u->cu_mask & U32_ATTR_SELECTOR))
		return -NLE_INVAL;

	sel = u32_selector(u);
	if (index >= sel->nkeys)
		return -NLE_RANGE;

	*mask = sel->keys[index].mask;
	*val = sel->keys[index].val;
	*off = sel->keys[index].off;
	*offmask = sel->keys[index].offmask;
	return 0;
}


int rtnl_u32_add_key_uint8(struct rtnl_cls *cls, uint8_t val, uint8_t mask,
			   int off, int offmask)
{
	int shift = 24 - 8 * (off & 3);

	return rtnl_u32_add_key(cls, htonl((uint32_t)val << shift),
				htonl((uint32_t)mask << shift),
				off & ~3, offmask);
}

/**
 * Append new selector key to match a 16-bit number
 *
 * @arg cls	classifier to be modified
 * @arg val	value to be matched (host byte-order)
 * @arg mask	mask to be applied before matching (host byte-order)
 * @arg off	offset, in bytes, to start matching
 * @arg offmask	offset mask
*/
int rtnl_u32_add_key_uint16(struct rtnl_cls *cls, uint16_t val, uint16_t mask,
			    int off, int offmask)
{
	int shift = ((off & 3) == 0 ? 16 : 0);
	if (off % 2)
		return -NLE_INVAL;

	return rtnl_u32_add_key(cls, htonl((uint32_t)val << shift),
				htonl((uint32_t)mask << shift),
				off & ~3, offmask);
}

/**
 * Append new selector key to match a 32-bit number
 *
 * @arg cls	classifier to be modified
 * @arg val	value to be matched (host byte-order)
 * @arg mask	mask to be applied before matching (host byte-order)
 * @arg off	offset, in bytes, to start matching
 * @arg offmask	offset mask
*/
int rtnl_u32_add_key_uint32(struct rtnl_cls *cls, uint32_t val, uint32_t mask,
			    int off, int offmask)
{
	return rtnl_u32_add_key(cls, htonl(val), htonl(mask),
				off & ~3, offmask);
}

int rtnl_u32_add_key_in_addr(struct rtnl_cls *cls, const struct in_addr *addr,
			     uint8_t bitmask, int off, int offmask)
{
	uint32_t mask = 0xFFFFFFFF << (32 - bitmask);
	return rtnl_u32_add_key(cls, addr->s_addr, htonl(mask), off, offmask);
}

int rtnl_u32_add_key_in6_addr(struct rtnl_cls *cls, const struct in6_addr *addr,
			      uint8_t bitmask, int off, int offmask)
{
	int i, err;

	for (i = 1; i <= 4; i++) {
		if (32 * i - bitmask <= 0) {
			if ((err = rtnl_u32_add_key(cls, addr->s6_addr32[i-1],
						0xFFFFFFFF, off+4*(i-1), offmask)) < 0)
				return err;
		}
		else if (32 * i - bitmask < 32) {
			uint32_t mask = 0xFFFFFFFF << (32 * i - bitmask);
			if ((err = rtnl_u32_add_key(cls, addr->s6_addr32[i-1],
						htonl(mask), off+4*(i-1), offmask)) < 0)
				return err;
		}
		/* otherwise, if (32*i - bitmask >= 32) no key is generated */
	}

	return 0;
}

/** @} */

static struct rtnl_tc_ops u32_ops = {
	.to_kind		= "u32",
	.to_type		= RTNL_TC_TYPE_CLS,
	.to_size		= sizeof(struct rtnl_u32),
	.to_msg_parser		= u32_msg_parser,
	.to_free_data		= u32_free_data,
	.to_clone		= u32_clone,
	.to_msg_fill		= u32_msg_fill,
	.to_dump = {
	    [NL_DUMP_LINE]	= u32_dump_line,
	    [NL_DUMP_DETAILS]	= u32_dump_details,
	    [NL_DUMP_STATS]	= u32_dump_stats,
	},
};

static void _nl_init u32_init(void)
{
	rtnl_tc_register(&u32_ops);
}

static void _nl_exit u32_exit(void)
{
	rtnl_tc_unregister(&u32_ops);
}

/** @} */