meta.c

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * Copyright (c) 2010-2013 Thomas Graf <tgraf@suug.ch>
 */
 
/**
 * @ingroup ematch
 * @defgroup em_meta Metadata Match
 *
 * @{
 */
 
#include <netlink-private/netlink.h>
#include <netlink-private/tc.h>
#include <netlink/netlink.h>
#include <netlink/route/cls/ematch.h>
#include <netlink/route/cls/ematch/meta.h>
#include <linux/tc_ematch/tc_em_meta.h>
 
struct rtnl_meta_value
{
        uint8_t                 mv_type;
        uint8_t                 mv_shift;
        uint16_t                mv_id;
        size_t                  mv_len;
};
 
struct meta_data
{
        struct rtnl_meta_value *        left;
        struct rtnl_meta_value *        right;
        uint8_t                         opnd;
};
 
static struct rtnl_meta_value *meta_alloc(uint8_t type, uint16_t id,
                                          uint8_t shift, void *data,
                                          size_t len)
{
        struct rtnl_meta_value *value;
 
        if (!(value = calloc(1, sizeof(*value) + len)))
                return NULL;
 
        value->mv_type = type;
        value->mv_id = id;
        value->mv_shift = shift;
        value->mv_len = len;
 
        if (len)
                memcpy(value + 1, data, len);
 
        return value;
}
 
struct rtnl_meta_value *rtnl_meta_value_alloc_int(uint64_t value)
{
        return meta_alloc(TCF_META_TYPE_INT, TCF_META_ID_VALUE, 0, &value, 8);
}
 
struct rtnl_meta_value *rtnl_meta_value_alloc_var(void *data, size_t len)
{
        return meta_alloc(TCF_META_TYPE_VAR, TCF_META_ID_VALUE, 0, data, len);
}
 
struct rtnl_meta_value *rtnl_meta_value_alloc_id(uint8_t type, uint16_t id,
                                                 uint8_t shift, uint64_t mask)
{
        size_t masklen = 0;
 
        if (id > TCF_META_ID_MAX)
                return NULL;
 
        if (mask) {
                if (type == TCF_META_TYPE_VAR)
                        return NULL;
 
                masklen = 8;
        }
 
        return meta_alloc(type, id, shift, &mask, masklen);
}
 
void rtnl_meta_value_put(struct rtnl_meta_value *mv)
{
        free(mv);
}
 
void rtnl_ematch_meta_set_lvalue(struct rtnl_ematch *e, struct rtnl_meta_value *v)
{
        struct meta_data *m = rtnl_ematch_data(e);
        m->left = v;
}
 
void rtnl_ematch_meta_set_rvalue(struct rtnl_ematch *e, struct rtnl_meta_value *v)
{
        struct meta_data *m = rtnl_ematch_data(e);
        m->right = v;
}
 
void rtnl_ematch_meta_set_operand(struct rtnl_ematch *e, uint8_t opnd)
{
        struct meta_data *m = rtnl_ematch_data(e);
        m->opnd = opnd;
}
 
static struct nla_policy meta_policy[TCA_EM_META_MAX+1] = {
        [TCA_EM_META_HDR]       = { .minlen = sizeof(struct tcf_meta_hdr) },
        [TCA_EM_META_LVALUE]    = { .minlen = 1, },
        [TCA_EM_META_RVALUE]    = { .minlen = 1, },
};
 
static int meta_parse(struct rtnl_ematch *e, void *data, size_t len)
{
        struct meta_data *m = rtnl_ematch_data(e);
        struct nlattr *tb[TCA_EM_META_MAX+1];
        struct rtnl_meta_value *v;
        struct tcf_meta_hdr *hdr;
        void *vdata = NULL;
        size_t vlen = 0;
        int err;
 
        if ((err = nla_parse(tb, TCA_EM_META_MAX, data, len, meta_policy)) < 0)
                return err;
 
        if (!tb[TCA_EM_META_HDR])
                return -NLE_MISSING_ATTR;
 
        hdr = nla_data(tb[TCA_EM_META_HDR]);
 
        if (tb[TCA_EM_META_LVALUE]) {
                vdata = nla_data(tb[TCA_EM_META_LVALUE]);
                vlen = nla_len(tb[TCA_EM_META_LVALUE]);
        }
 
        v = meta_alloc(TCF_META_TYPE(hdr->left.kind),
                       TCF_META_ID(hdr->left.kind),
                       hdr->left.shift, vdata, vlen);
        if (!v)
                return -NLE_NOMEM;
 
        m->left = v;
 
        vlen = 0;
        if (tb[TCA_EM_META_RVALUE]) {
                vdata = nla_data(tb[TCA_EM_META_RVALUE]);
                vlen = nla_len(tb[TCA_EM_META_RVALUE]);
        }
 
        v = meta_alloc(TCF_META_TYPE(hdr->right.kind),
                       TCF_META_ID(hdr->right.kind),
                       hdr->right.shift, vdata, vlen);
        if (!v) {
                rtnl_meta_value_put(m->left);
                return -NLE_NOMEM;
        }
 
        m->right = v;
        m->opnd = hdr->left.op;
 
        return 0;
}
 
static const struct trans_tbl meta_int[] = {
        __ADD(TCF_META_ID_RANDOM, random),
        __ADD(TCF_META_ID_LOADAVG_0, loadavg_0),
        __ADD(TCF_META_ID_LOADAVG_1, loadavg_1),
        __ADD(TCF_META_ID_LOADAVG_2, loadavg_2),
        __ADD(TCF_META_ID_DEV, dev),
        __ADD(TCF_META_ID_PRIORITY, prio),
        __ADD(TCF_META_ID_PROTOCOL, proto),
        __ADD(TCF_META_ID_PKTTYPE, pkttype),
        __ADD(TCF_META_ID_PKTLEN, pktlen),
        __ADD(TCF_META_ID_DATALEN, datalen),
        __ADD(TCF_META_ID_MACLEN, maclen),
        __ADD(TCF_META_ID_NFMARK, mark),
        __ADD(TCF_META_ID_TCINDEX, tcindex),
        __ADD(TCF_META_ID_RTCLASSID, rtclassid),
        __ADD(TCF_META_ID_RTIIF, rtiif),
        __ADD(TCF_META_ID_SK_FAMILY, sk_family),
        __ADD(TCF_META_ID_SK_STATE, sk_state),
        __ADD(TCF_META_ID_SK_REUSE, sk_reuse),
        __ADD(TCF_META_ID_SK_REFCNT, sk_refcnt),
        __ADD(TCF_META_ID_SK_RCVBUF, sk_rcvbuf),
        __ADD(TCF_META_ID_SK_SNDBUF, sk_sndbuf),
        __ADD(TCF_META_ID_SK_SHUTDOWN, sk_sutdown),
        __ADD(TCF_META_ID_SK_PROTO, sk_proto),
        __ADD(TCF_META_ID_SK_TYPE, sk_type),
        __ADD(TCF_META_ID_SK_RMEM_ALLOC, sk_rmem_alloc),
        __ADD(TCF_META_ID_SK_WMEM_ALLOC, sk_wmem_alloc),
        __ADD(TCF_META_ID_SK_WMEM_QUEUED, sk_wmem_queued),
        __ADD(TCF_META_ID_SK_RCV_QLEN, sk_rcv_qlen),
        __ADD(TCF_META_ID_SK_SND_QLEN, sk_snd_qlen),
        __ADD(TCF_META_ID_SK_ERR_QLEN, sk_err_qlen),
        __ADD(TCF_META_ID_SK_FORWARD_ALLOCS, sk_forward_allocs),
        __ADD(TCF_META_ID_SK_ALLOCS, sk_allocs),
        __ADD(__TCF_META_ID_SK_ROUTE_CAPS, sk_route_caps),
        __ADD(TCF_META_ID_SK_HASH, sk_hash),
        __ADD(TCF_META_ID_SK_LINGERTIME, sk_lingertime),
        __ADD(TCF_META_ID_SK_ACK_BACKLOG, sk_ack_backlog),
        __ADD(TCF_META_ID_SK_MAX_ACK_BACKLOG, sk_max_ack_backlog),
        __ADD(TCF_META_ID_SK_PRIO, sk_prio),
        __ADD(TCF_META_ID_SK_RCVLOWAT, sk_rcvlowat),
        __ADD(TCF_META_ID_SK_RCVTIMEO, sk_rcvtimeo),
        __ADD(TCF_META_ID_SK_SNDTIMEO, sk_sndtimeo),
        __ADD(TCF_META_ID_SK_SENDMSG_OFF, sk_sendmsg_off),
        __ADD(TCF_META_ID_SK_WRITE_PENDING, sk_write_pending),
        __ADD(TCF_META_ID_VLAN_TAG, vlan),
        __ADD(TCF_META_ID_RXHASH, rxhash),
};
 
static char *int_id2str(int id, char *buf, size_t size)
{
        return __type2str(id, buf, size, meta_int, ARRAY_SIZE(meta_int));
}
 
static const struct trans_tbl meta_var[] = {
        __ADD(TCF_META_ID_DEV,devname),
        __ADD(TCF_META_ID_SK_BOUND_IF,sk_bound_if),
};
 
static char *var_id2str(int id, char *buf, size_t size)
{
        return __type2str(id, buf, size, meta_var, ARRAY_SIZE(meta_var));
}
 
static void dump_value(struct rtnl_meta_value *v, struct nl_dump_params *p)
{
        char buf[32];
 
        switch (v->mv_type) {
                case TCF_META_TYPE_INT:
                        if (v->mv_id == TCF_META_ID_VALUE) {
                                nl_dump(p, "%u",
                                        *(uint32_t *) (v + 1));
                        } else {
                                nl_dump(p, "%s",
                                        int_id2str(v->mv_id, buf, sizeof(buf)));
 
                                if (v->mv_shift)
                                        nl_dump(p, " >> %u", v->mv_shift);
 
                                if (v->mv_len == 4)
                                        nl_dump(p, " & %#lx", (long unsigned) *(uint32_t *) (v + 1));
                                else if (v->mv_len == 8)
                                        nl_dump(p, " & %#llx", (long long unsigned) (*(uint64_t *) (v + 1)));
                        }
                break;
 
                case TCF_META_TYPE_VAR:
                        if (v->mv_id == TCF_META_ID_VALUE) {
                                nl_dump(p, "%s", (char *) (v + 1));
                        } else {
                                nl_dump(p, "%s",
                                        var_id2str(v->mv_id, buf, sizeof(buf)));
 
                                if (v->mv_shift)
                                        nl_dump(p, " >> %u", v->mv_shift);
                        }
                break;
        }
}
 
static void meta_dump(struct rtnl_ematch *e, struct nl_dump_params *p)
{
        struct meta_data *m = rtnl_ematch_data(e);
        char buf[32];
 
        nl_dump(p, "meta(");
        dump_value(m->left, p);
 
        nl_dump(p, " %s ", rtnl_ematch_opnd2txt(m->opnd, buf, sizeof(buf)));
 
        dump_value(m->right, p);
        nl_dump(p, ")");
}
 
static int meta_fill(struct rtnl_ematch *e, struct nl_msg *msg)
{
        struct meta_data *m = rtnl_ematch_data(e);
        struct tcf_meta_hdr hdr;
 
        if (!(m->left && m->right))
                return -NLE_MISSING_ATTR;
 
        memset(&hdr, 0, sizeof(hdr));
        hdr.left.kind = (m->left->mv_type << 12) & TCF_META_TYPE_MASK;
        hdr.left.kind |= m->left->mv_id & TCF_META_ID_MASK;
        hdr.left.shift = m->left->mv_shift;
        hdr.left.op = m->opnd;
        hdr.right.kind = (m->right->mv_type << 12) & TCF_META_TYPE_MASK;
        hdr.right.kind |= m->right->mv_id & TCF_META_ID_MASK;
 
        NLA_PUT(msg, TCA_EM_META_HDR, sizeof(hdr), &hdr);
 
        if (m->left->mv_len)
                NLA_PUT(msg, TCA_EM_META_LVALUE, m->left->mv_len, (m->left + 1));
        
        if (m->right->mv_len)
                NLA_PUT(msg, TCA_EM_META_RVALUE, m->right->mv_len, (m->right + 1));
 
        return 0;
 
nla_put_failure:
        return -NLE_NOMEM;
}
 
static void meta_free(struct rtnl_ematch *e)
{
        struct meta_data *m = rtnl_ematch_data(e);
        free(m->left);
        free(m->right);
}
 
static struct rtnl_ematch_ops meta_ops = {
        .eo_kind        = TCF_EM_META,
        .eo_name        = "meta",
        .eo_minlen      = sizeof(struct tcf_meta_hdr),
        .eo_datalen     = sizeof(struct meta_data),
        .eo_parse       = meta_parse,
        .eo_dump        = meta_dump,
        .eo_fill        = meta_fill,
        .eo_free        = meta_free,
};
 
static void __init meta_init(void)
{
        rtnl_ematch_register(&meta_ops);
}
 
/** @} */