lib/isc/portset.c

/*
 * Copyright (C) 2008  Internet Systems Consortium, Inc. ("ISC")
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: portset.c,v 1.4 2008/06/24 23:24:35 marka Exp $ */

/*! \file */

#include <config.h>

#include <isc/mem.h>
#include <isc/portset.h>
#include <isc/string.h>
#include <isc/types.h>
#include <isc/util.h>

#define ISC_PORTSET_BUFSIZE (65536 / (sizeof(isc_uint32_t) * 8))

/*%
 * Internal representation of portset.  It's an array of 32-bit integers, each
 * bit corresponding to a single port in the ascending order.  For example,
 * the second most significant bit of buf[0] corresponds to port 1.
 */
struct isc_portset {
    unsigned int nports;    /*%< number of ports in the set */
    isc_uint32_t buf[ISC_PORTSET_BUFSIZE];
};

static inline isc_boolean_t
portset_isset(isc_portset_t *portset, in_port_t port) {
    return (ISC_TF((portset->buf[port >> 5] & (1 << (port & 31))) != 0));
}

static inline void
portset_add(isc_portset_t *portset, in_port_t port) {
    if (!portset_isset(portset, port)) {
        portset->nports++;
        portset->buf[port >> 5] |= (1 << (port & 31));
    }
}

static inline void
portset_remove(isc_portset_t *portset, in_port_t port) {
    if (portset_isset(portset, port)) {
        portset->nports--;
        portset->buf[port >> 5] &= ~(1 << (port & 31));
    }
}

isc_result_t
isc_portset_create(isc_mem_t *mctx, isc_portset_t **portsetp) {
    isc_portset_t *portset;

    REQUIRE(portsetp != NULL && *portsetp == NULL);

    portset = isc_mem_get(mctx, sizeof(*portset));
    if (portset == NULL)
        return (ISC_R_NOMEMORY);

    /* Make the set 'empty' by default */
    memset(portset, 0, sizeof(*portset));
    *portsetp = portset;

    return (ISC_R_SUCCESS);
}

void
isc_portset_destroy(isc_mem_t *mctx, isc_portset_t **portsetp) {
    isc_portset_t *portset;

    REQUIRE(portsetp != NULL);
    portset = *portsetp;

    isc_mem_put(mctx, portset, sizeof(*portset));
}

isc_boolean_t
isc_portset_isset(isc_portset_t *portset, in_port_t port) {
    REQUIRE(portset != NULL);

    return (portset_isset(portset, port));
}

unsigned int
isc_portset_nports(isc_portset_t *portset) {
    REQUIRE(portset != NULL);

    return (portset->nports);
}

void
isc_portset_add(isc_portset_t *portset, in_port_t port) {
    REQUIRE(portset != NULL);

    portset_add(portset, port);
}

void
isc_portset_remove(isc_portset_t *portset, in_port_t port) {
    portset_remove(portset, port);
}

void
isc_portset_addrange(isc_portset_t *portset, in_port_t port_lo,
             in_port_t port_hi)
{
    in_port_t p;

    REQUIRE(portset != NULL);
    REQUIRE(port_lo <= port_hi);

    p = port_lo;
    do {
        portset_add(portset, p);
    } while (p++ < port_hi);
}

void
isc_portset_removerange(isc_portset_t *portset, in_port_t port_lo,
            in_port_t port_hi)
{
    in_port_t p;

    REQUIRE(portset != NULL);
    REQUIRE(port_lo <= port_hi);

    p = port_lo;
    do {
        portset_remove(portset, p);
    } while (p++ < port_hi);
}