nbyte.c

/*
 * lib/route/cls/ematch/nbyte.c         Nbyte comparison
 *
 *      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) 2010-2013 Thomas Graf <tgraf@suug.ch>
 */

/**
 * @ingroup ematch
 * @defgroup em_nbyte N-Byte Comparison
 *
 * @{
 */

#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/nbyte.h>

struct nbyte_data
{
        struct tcf_em_nbyte     cfg;
        uint8_t *               pattern;
};

void rtnl_ematch_nbyte_set_offset(struct rtnl_ematch *e, uint8_t layer,
                                  uint16_t offset)
{
        struct nbyte_data *n = rtnl_ematch_data(e);
        n->cfg.off = offset;
        n->cfg.layer = layer;
}

uint16_t rtnl_ematch_nbyte_get_offset(struct rtnl_ematch *e)
{
        return ((struct nbyte_data *) rtnl_ematch_data(e))->cfg.off;
}

uint8_t rtnl_ematch_nbyte_get_layer(struct rtnl_ematch *e)
{
        return ((struct nbyte_data *) rtnl_ematch_data(e))->cfg.layer;
}

void rtnl_ematch_nbyte_set_pattern(struct rtnl_ematch *e,
                                   uint8_t *pattern, size_t len)
{
        struct nbyte_data *n = rtnl_ematch_data(e);

        if (n->pattern)
                free(n->pattern);

        n->pattern = pattern;
        n->cfg.len = len;
}

uint8_t *rtnl_ematch_nbyte_get_pattern(struct rtnl_ematch *e)
{
        return ((struct nbyte_data *) rtnl_ematch_data(e))->pattern;
}

size_t rtnl_ematch_nbyte_get_len(struct rtnl_ematch *e)
{
        return ((struct nbyte_data *) rtnl_ematch_data(e))->cfg.len;
}

static const char *layer_txt(struct tcf_em_nbyte *nbyte)
{
        switch (nbyte->layer) {
        case TCF_LAYER_LINK:
                return "link";
        case TCF_LAYER_NETWORK:
                return "net";
        case TCF_LAYER_TRANSPORT:
                return "trans";
        default:
                return "?";
        }
}

static int nbyte_parse(struct rtnl_ematch *e, void *data, size_t len)
{
        struct nbyte_data *n = rtnl_ematch_data(e);
        size_t hdrlen = sizeof(struct tcf_em_nbyte);
        size_t plen = len - hdrlen;

        memcpy(&n->cfg, data, hdrlen);
        if (plen > 0) {
                if (!(n->pattern = calloc(1, plen)))
                        return -NLE_NOMEM;

                memcpy(n->pattern, data + hdrlen, plen);
        }

        return 0;
}

static void nbyte_dump(struct rtnl_ematch *e, struct nl_dump_params *p)
{
        struct nbyte_data *n = rtnl_ematch_data(e);
        int i;

        nl_dump(p, "pattern(%u:[", n->cfg.len);

        for (i = 0; i < n->cfg.len; i++) {
                nl_dump(p, "%02x", n->pattern[i]);
                if (i+1 < n->cfg.len)
                        nl_dump(p, " ");
        }

        nl_dump(p, "] at %s+%u)", layer_txt(&n->cfg), n->cfg.off);
}

static void nbyte_free(struct rtnl_ematch *e)
{
        struct nbyte_data *n = rtnl_ematch_data(e);
        free(n->pattern);
}

static struct rtnl_ematch_ops nbyte_ops = {
        .eo_kind        = TCF_EM_NBYTE,
        .eo_name        = "nbyte",
        .eo_minlen      = sizeof(struct tcf_em_nbyte),
        .eo_datalen     = sizeof(struct nbyte_data),
        .eo_parse       = nbyte_parse,
        .eo_dump        = nbyte_dump,
        .eo_free        = nbyte_free,
};

static void __init nbyte_init(void)
{
        rtnl_ematch_register(&nbyte_ops);
}

/** @} */