ip_set_bitmap_port.c

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/* Copyright (C) 2003-2011 Jozsef Kadlecsik <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/* Kernel module implementing an IP set type: the bitmap:port type */

#include <linux/module.h>
#include <linux/ip.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/netlink.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <net/netlink.h>

#include <linux/netfilter/ipset/ip_set.h>
#include <linux/netfilter/ipset/ip_set_bitmap.h>
#include <linux/netfilter/ipset/ip_set_getport.h>
#define IP_SET_BITMAP_TIMEOUT
#include <linux/netfilter/ipset/ip_set_timeout.h>

#define REVISION_MIN    0
#define REVISION_MAX    0

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jozsef Kadlecsik <[email protected]>");
IP_SET_MODULE_DESC("bitmap:port", REVISION_MIN, REVISION_MAX);
MODULE_ALIAS("ip_set_bitmap:port");

/* Type structure */
struct bitmap_port {
    void *members;      /* the set members */
    u16 first_port;     /* host byte order, included in range */
    u16 last_port;      /* host byte order, included in range */
    size_t memsize;     /* members size */
    u32 timeout;        /* timeout parameter */
    struct timer_list gc;   /* garbage collection */
};

/* Base variant */

static int
bitmap_port_test(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
    const struct bitmap_port *map = set->data;
    u16 id = *(u16 *)value;

    return !!test_bit(id, map->members);
}

static int
bitmap_port_add(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
    struct bitmap_port *map = set->data;
    u16 id = *(u16 *)value;

    if (test_and_set_bit(id, map->members))
        return -IPSET_ERR_EXIST;

    return 0;
}

static int
bitmap_port_del(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
    struct bitmap_port *map = set->data;
    u16 id = *(u16 *)value;

    if (!test_and_clear_bit(id, map->members))
        return -IPSET_ERR_EXIST;

    return 0;
}

static int
bitmap_port_list(const struct ip_set *set,
         struct sk_buff *skb, struct netlink_callback *cb)
{
    const struct bitmap_port *map = set->data;
    struct nlattr *atd, *nested;
    u16 id, first = cb->args[2];
    u16 last = map->last_port - map->first_port;

    atd = ipset_nest_start(skb, IPSET_ATTR_ADT);
    if (!atd)
        return -EMSGSIZE;
    for (; cb->args[2] <= last; cb->args[2]++) {
        id = cb->args[2];
        if (!test_bit(id, map->members))
            continue;
        nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
        if (!nested) {
            if (id == first) {
                nla_nest_cancel(skb, atd);
                return -EMSGSIZE;
            } else
                goto nla_put_failure;
        }
        if (nla_put_net16(skb, IPSET_ATTR_PORT,
                  htons(map->first_port + id)))
            goto nla_put_failure;
        ipset_nest_end(skb, nested);
    }
    ipset_nest_end(skb, atd);
    /* Set listing finished */
    cb->args[2] = 0;

    return 0;

nla_put_failure:
    nla_nest_cancel(skb, nested);
    ipset_nest_end(skb, atd);
    if (unlikely(id == first)) {
        cb->args[2] = 0;
        return -EMSGSIZE;
    }
    return 0;
}

/* Timeout variant */

static int
bitmap_port_ttest(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
    const struct bitmap_port *map = set->data;
    const unsigned long *members = map->members;
    u16 id = *(u16 *)value;

    return ip_set_timeout_test(members[id]);
}

static int
bitmap_port_tadd(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
    struct bitmap_port *map = set->data;
    unsigned long *members = map->members;
    u16 id = *(u16 *)value;

    if (ip_set_timeout_test(members[id]) && !(flags & IPSET_FLAG_EXIST))
        return -IPSET_ERR_EXIST;

    members[id] = ip_set_timeout_set(timeout);

    return 0;
}

static int
bitmap_port_tdel(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
    struct bitmap_port *map = set->data;
    unsigned long *members = map->members;
    u16 id = *(u16 *)value;
    int ret = -IPSET_ERR_EXIST;

    if (ip_set_timeout_test(members[id]))
        ret = 0;

    members[id] = IPSET_ELEM_UNSET;
    return ret;
}

static int
bitmap_port_tlist(const struct ip_set *set,
          struct sk_buff *skb, struct netlink_callback *cb)
{
    const struct bitmap_port *map = set->data;
    struct nlattr *adt, *nested;
    u16 id, first = cb->args[2];
    u16 last = map->last_port - map->first_port;
    const unsigned long *members = map->members;

    adt = ipset_nest_start(skb, IPSET_ATTR_ADT);
    if (!adt)
        return -EMSGSIZE;
    for (; cb->args[2] <= last; cb->args[2]++) {
        id = cb->args[2];
        if (!ip_set_timeout_test(members[id]))
            continue;
        nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
        if (!nested) {
            if (id == first) {
                nla_nest_cancel(skb, adt);
                return -EMSGSIZE;
            } else
                goto nla_put_failure;
        }
        if (nla_put_net16(skb, IPSET_ATTR_PORT,
                  htons(map->first_port + id)) ||
            nla_put_net32(skb, IPSET_ATTR_TIMEOUT,
                  htonl(ip_set_timeout_get(members[id]))))
            goto nla_put_failure;
        ipset_nest_end(skb, nested);
    }
    ipset_nest_end(skb, adt);

    /* Set listing finished */
    cb->args[2] = 0;

    return 0;

nla_put_failure:
    nla_nest_cancel(skb, nested);
    ipset_nest_end(skb, adt);
    if (unlikely(id == first)) {
        cb->args[2] = 0;
        return -EMSGSIZE;
    }
    return 0;
}

static int
bitmap_port_kadt(struct ip_set *set, const struct sk_buff *skb,
         const struct xt_action_param *par,
         enum ipset_adt adt, const struct ip_set_adt_opt *opt)
{
    struct bitmap_port *map = set->data;
    ipset_adtfn adtfn = set->variant->adt[adt];
    __be16 __port;
    u16 port = 0;

    if (!ip_set_get_ip_port(skb, opt->family,
                opt->flags & IPSET_DIM_ONE_SRC, &__port))
        return -EINVAL;

    port = ntohs(__port);

    if (port < map->first_port || port > map->last_port)
        return -IPSET_ERR_BITMAP_RANGE;

    port -= map->first_port;

    return adtfn(set, &port, opt_timeout(opt, map), opt->cmdflags);
}

static int
bitmap_port_uadt(struct ip_set *set, struct nlattr *tb[],
         enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
{
    struct bitmap_port *map = set->data;
    ipset_adtfn adtfn = set->variant->adt[adt];
    u32 timeout = map->timeout;
    u32 port;   /* wraparound */
    u16 id, port_to;
    int ret = 0;

    if (unlikely(!ip_set_attr_netorder(tb, IPSET_ATTR_PORT) ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_PORT_TO) ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT)))
        return -IPSET_ERR_PROTOCOL;

    if (tb[IPSET_ATTR_LINENO])
        *lineno = nla_get_u32(tb[IPSET_ATTR_LINENO]);

    port = ip_set_get_h16(tb[IPSET_ATTR_PORT]);
    if (port < map->first_port || port > map->last_port)
        return -IPSET_ERR_BITMAP_RANGE;

    if (tb[IPSET_ATTR_TIMEOUT]) {
        if (!with_timeout(map->timeout))
            return -IPSET_ERR_TIMEOUT;
        timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
    }

    if (adt == IPSET_TEST) {
        id = port - map->first_port;
        return adtfn(set, &id, timeout, flags);
    }

    if (tb[IPSET_ATTR_PORT_TO]) {
        port_to = ip_set_get_h16(tb[IPSET_ATTR_PORT_TO]);
        if (port > port_to) {
            swap(port, port_to);
            if (port < map->first_port)
                return -IPSET_ERR_BITMAP_RANGE;
        }
    } else
        port_to = port;

    if (port_to > map->last_port)
        return -IPSET_ERR_BITMAP_RANGE;

    for (; port <= port_to; port++) {
        id = port - map->first_port;
        ret = adtfn(set, &id, timeout, flags);

        if (ret && !ip_set_eexist(ret, flags))
            return ret;
        else
            ret = 0;
    }
    return ret;
}

static void
bitmap_port_destroy(struct ip_set *set)
{
    struct bitmap_port *map = set->data;

    if (with_timeout(map->timeout))
        del_timer_sync(&map->gc);

    ip_set_free(map->members);
    kfree(map);

    set->data = NULL;
}

static void
bitmap_port_flush(struct ip_set *set)
{
    struct bitmap_port *map = set->data;

    memset(map->members, 0, map->memsize);
}

static int
bitmap_port_head(struct ip_set *set, struct sk_buff *skb)
{
    const struct bitmap_port *map = set->data;
    struct nlattr *nested;

    nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
    if (!nested)
        goto nla_put_failure;
    if (nla_put_net16(skb, IPSET_ATTR_PORT, htons(map->first_port)) ||
        nla_put_net16(skb, IPSET_ATTR_PORT_TO, htons(map->last_port)) ||
        nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1)) ||
        nla_put_net32(skb, IPSET_ATTR_MEMSIZE,
              htonl(sizeof(*map) + map->memsize)) ||
        (with_timeout(map->timeout) &&
         nla_put_net32(skb, IPSET_ATTR_TIMEOUT, htonl(map->timeout))))
        goto nla_put_failure;
    ipset_nest_end(skb, nested);

    return 0;
nla_put_failure:
    return -EMSGSIZE;
}

static bool
bitmap_port_same_set(const struct ip_set *a, const struct ip_set *b)
{
    const struct bitmap_port *x = a->data;
    const struct bitmap_port *y = b->data;

    return x->first_port == y->first_port &&
           x->last_port == y->last_port &&
           x->timeout == y->timeout;
}

static const struct ip_set_type_variant bitmap_port = {
    .kadt   = bitmap_port_kadt,
    .uadt   = bitmap_port_uadt,
    .adt    = {
        [IPSET_ADD] = bitmap_port_add,
        [IPSET_DEL] = bitmap_port_del,
        [IPSET_TEST] = bitmap_port_test,
    },
    .destroy = bitmap_port_destroy,
    .flush  = bitmap_port_flush,
    .head   = bitmap_port_head,
    .list   = bitmap_port_list,
    .same_set = bitmap_port_same_set,
};

static const struct ip_set_type_variant bitmap_tport = {
    .kadt   = bitmap_port_kadt,
    .uadt   = bitmap_port_uadt,
    .adt    = {
        [IPSET_ADD] = bitmap_port_tadd,
        [IPSET_DEL] = bitmap_port_tdel,
        [IPSET_TEST] = bitmap_port_ttest,
    },
    .destroy = bitmap_port_destroy,
    .flush  = bitmap_port_flush,
    .head   = bitmap_port_head,
    .list   = bitmap_port_tlist,
    .same_set = bitmap_port_same_set,
};

static void
bitmap_port_gc(unsigned long ul_set)
{
    struct ip_set *set = (struct ip_set *) ul_set;
    struct bitmap_port *map = set->data;
    unsigned long *table = map->members;
    u32 id; /* wraparound */
    u16 last = map->last_port - map->first_port;

    /* We run parallel with other readers (test element)
     * but adding/deleting new entries is locked out */
    read_lock_bh(&set->lock);
    for (id = 0; id <= last; id++)
        if (ip_set_timeout_expired(table[id]))
            table[id] = IPSET_ELEM_UNSET;
    read_unlock_bh(&set->lock);

    map->gc.expires = jiffies + IPSET_GC_PERIOD(map->timeout) * HZ;
    add_timer(&map->gc);
}

static void
bitmap_port_gc_init(struct ip_set *set)
{
    struct bitmap_port *map = set->data;

    init_timer(&map->gc);
    map->gc.data = (unsigned long) set;
    map->gc.function = bitmap_port_gc;
    map->gc.expires = jiffies + IPSET_GC_PERIOD(map->timeout) * HZ;
    add_timer(&map->gc);
}

/* Create bitmap:ip type of sets */

static bool
init_map_port(struct ip_set *set, struct bitmap_port *map,
          u16 first_port, u16 last_port)
{
    map->members = ip_set_alloc(map->memsize);
    if (!map->members)
        return false;
    map->first_port = first_port;
    map->last_port = last_port;
    map->timeout = IPSET_NO_TIMEOUT;

    set->data = map;
    set->family = NFPROTO_UNSPEC;

    return true;
}

static int
bitmap_port_create(struct ip_set *set, struct nlattr *tb[],
         u32 flags)
{
    struct bitmap_port *map;
    u16 first_port, last_port;

    if (unlikely(!ip_set_attr_netorder(tb, IPSET_ATTR_PORT) ||
             !ip_set_attr_netorder(tb, IPSET_ATTR_PORT_TO) ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT)))
        return -IPSET_ERR_PROTOCOL;

    first_port = ip_set_get_h16(tb[IPSET_ATTR_PORT]);
    last_port = ip_set_get_h16(tb[IPSET_ATTR_PORT_TO]);
    if (first_port > last_port) {
        u16 tmp = first_port;

        first_port = last_port;
        last_port = tmp;
    }

    map = kzalloc(sizeof(*map), GFP_KERNEL);
    if (!map)
        return -ENOMEM;

    if (tb[IPSET_ATTR_TIMEOUT]) {
        map->memsize = (last_port - first_port + 1)
                   * sizeof(unsigned long);

        if (!init_map_port(set, map, first_port, last_port)) {
            kfree(map);
            return -ENOMEM;
        }

        map->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);
        set->variant = &bitmap_tport;

        bitmap_port_gc_init(set);
    } else {
        map->memsize = bitmap_bytes(0, last_port - first_port);
        pr_debug("memsize: %zu\n", map->memsize);
        if (!init_map_port(set, map, first_port, last_port)) {
            kfree(map);
            return -ENOMEM;
        }

        set->variant = &bitmap_port;
    }
    return 0;
}

static struct ip_set_type bitmap_port_type = {
    .name       = "bitmap:port",
    .protocol   = IPSET_PROTOCOL,
    .features   = IPSET_TYPE_PORT,
    .dimension  = IPSET_DIM_ONE,
    .family     = NFPROTO_UNSPEC,
    .revision_min   = REVISION_MIN,
    .revision_max   = REVISION_MAX,
    .create     = bitmap_port_create,
    .create_policy  = {
        [IPSET_ATTR_PORT]   = { .type = NLA_U16 },
        [IPSET_ATTR_PORT_TO]    = { .type = NLA_U16 },
        [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
    },
    .adt_policy = {
        [IPSET_ATTR_PORT]   = { .type = NLA_U16 },
        [IPSET_ATTR_PORT_TO]    = { .type = NLA_U16 },
        [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
        [IPSET_ATTR_LINENO] = { .type = NLA_U32 },
    },
    .me     = THIS_MODULE,
};

static int __init
bitmap_port_init(void)
{
    return ip_set_type_register(&bitmap_port_type);
}

static void __exit
bitmap_port_fini(void)
{
    ip_set_type_unregister(&bitmap_port_type);
}

module_init(bitmap_port_init);
module_exit(bitmap_port_fini);