ip_set_hash_net.c

Go to the documentation of this file.

/* 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 hash:net type */

#include <linux/jhash.h>
#include <linux/module.h>
#include <linux/ip.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/netlink.h>

#include <linux/netfilter.h>
#include <linux/netfilter/ipset/pfxlen.h>
#include <linux/netfilter/ipset/ip_set.h>
#include <linux/netfilter/ipset/ip_set_timeout.h>
#include <linux/netfilter/ipset/ip_set_hash.h>

#define REVISION_MIN    0
/*          1    Range as input support for IPv4 added */
#define REVISION_MAX    2 /* nomatch flag support added */

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jozsef Kadlecsik <[email protected]>");
IP_SET_MODULE_DESC("hash:net", REVISION_MIN, REVISION_MAX);
MODULE_ALIAS("ip_set_hash:net");

/* Type specific function prefix */
#define TYPE        hash_net

static bool
hash_net_same_set(const struct ip_set *a, const struct ip_set *b);

#define hash_net4_same_set  hash_net_same_set
#define hash_net6_same_set  hash_net_same_set

/* The type variant functions: IPv4 */

/* Member elements without timeout */
struct hash_net4_elem {
    __be32 ip;
    u16 padding0;
    u8 nomatch;
    u8 cidr;
};

/* Member elements with timeout support */
struct hash_net4_telem {
    __be32 ip;
    u16 padding0;
    u8 nomatch;
    u8 cidr;
    unsigned long timeout;
};

static inline bool
hash_net4_data_equal(const struct hash_net4_elem *ip1,
             const struct hash_net4_elem *ip2,
             u32 *multi)
{
    return ip1->ip == ip2->ip &&
           ip1->cidr == ip2->cidr;
}

static inline bool
hash_net4_data_isnull(const struct hash_net4_elem *elem)
{
    return elem->cidr == 0;
}

static inline void
hash_net4_data_copy(struct hash_net4_elem *dst,
            const struct hash_net4_elem *src)
{
    dst->ip = src->ip;
    dst->cidr = src->cidr;
    dst->nomatch = src->nomatch;
}

static inline void
hash_net4_data_flags(struct hash_net4_elem *dst, u32 flags)
{
    dst->nomatch = flags & IPSET_FLAG_NOMATCH;
}

static inline int
hash_net4_data_match(const struct hash_net4_elem *elem)
{
    return elem->nomatch ? -ENOTEMPTY : 1;
}

static inline void
hash_net4_data_netmask(struct hash_net4_elem *elem, u8 cidr)
{
    elem->ip &= ip_set_netmask(cidr);
    elem->cidr = cidr;
}

/* Zero CIDR values cannot be stored */
static inline void
hash_net4_data_zero_out(struct hash_net4_elem *elem)
{
    elem->cidr = 0;
}

static bool
hash_net4_data_list(struct sk_buff *skb, const struct hash_net4_elem *data)
{
    u32 flags = data->nomatch ? IPSET_FLAG_NOMATCH : 0;

    if (nla_put_ipaddr4(skb, IPSET_ATTR_IP, data->ip) ||
        nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
        (flags &&
         nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
        goto nla_put_failure;
    return 0;

nla_put_failure:
    return 1;
}

static bool
hash_net4_data_tlist(struct sk_buff *skb, const struct hash_net4_elem *data)
{
    const struct hash_net4_telem *tdata =
        (const struct hash_net4_telem *)data;
    u32 flags = data->nomatch ? IPSET_FLAG_NOMATCH : 0;

    if (nla_put_ipaddr4(skb, IPSET_ATTR_IP, tdata->ip) ||
        nla_put_u8(skb, IPSET_ATTR_CIDR, tdata->cidr) ||
        nla_put_net32(skb, IPSET_ATTR_TIMEOUT,
              htonl(ip_set_timeout_get(tdata->timeout))) ||
        (flags &&
         nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
        goto nla_put_failure;
    return 0;

nla_put_failure:
    return 1;
}

#define IP_SET_HASH_WITH_NETS

#define PF      4
#define HOST_MASK   32
#include <linux/netfilter/ipset/ip_set_ahash.h>

static inline void
hash_net4_data_next(struct ip_set_hash *h,
            const struct hash_net4_elem *d)
{
    h->next.ip = d->ip;
}

static int
hash_net4_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)
{
    const struct ip_set_hash *h = set->data;
    ipset_adtfn adtfn = set->variant->adt[adt];
    struct hash_net4_elem data = {
        .cidr = h->nets[0].cidr ? h->nets[0].cidr : HOST_MASK
    };

    if (data.cidr == 0)
        return -EINVAL;
    if (adt == IPSET_TEST)
        data.cidr = HOST_MASK;

    ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &data.ip);
    data.ip &= ip_set_netmask(data.cidr);

    return adtfn(set, &data, opt_timeout(opt, h), opt->cmdflags);
}

static int
hash_net4_uadt(struct ip_set *set, struct nlattr *tb[],
           enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
{
    const struct ip_set_hash *h = set->data;
    ipset_adtfn adtfn = set->variant->adt[adt];
    struct hash_net4_elem data = { .cidr = HOST_MASK };
    u32 timeout = h->timeout;
    u32 ip = 0, ip_to, last;
    int ret;

    if (unlikely(!tb[IPSET_ATTR_IP] ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
        return -IPSET_ERR_PROTOCOL;

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

    ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP], &ip);
    if (ret)
        return ret;

    if (tb[IPSET_ATTR_CIDR]) {
        data.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
        if (!data.cidr || data.cidr > HOST_MASK)
            return -IPSET_ERR_INVALID_CIDR;
    }

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

    if (tb[IPSET_ATTR_CADT_FLAGS] && adt == IPSET_ADD) {
        u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
        if (cadt_flags & IPSET_FLAG_NOMATCH)
            flags |= (cadt_flags << 16);
    }

    if (adt == IPSET_TEST || !tb[IPSET_ATTR_IP_TO]) {
        data.ip = htonl(ip & ip_set_hostmask(data.cidr));
        ret = adtfn(set, &data, timeout, flags);
        return ip_set_eexist(ret, flags) ? 0 : ret;
    }

    ip_to = ip;
    if (tb[IPSET_ATTR_IP_TO]) {
        ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
        if (ret)
            return ret;
        if (ip_to < ip)
            swap(ip, ip_to);
        if (ip + UINT_MAX == ip_to)
            return -IPSET_ERR_HASH_RANGE;
    }
    if (retried)
        ip = ntohl(h->next.ip);
    while (!after(ip, ip_to)) {
        data.ip = htonl(ip);
        last = ip_set_range_to_cidr(ip, ip_to, &data.cidr);
        ret = adtfn(set, &data, timeout, flags);
        if (ret && !ip_set_eexist(ret, flags))
            return ret;
        else
            ret = 0;
        ip = last + 1;
    }
    return ret;
}

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

    /* Resizing changes htable_bits, so we ignore it */
    return x->maxelem == y->maxelem &&
           x->timeout == y->timeout;
}

/* The type variant functions: IPv6 */

struct hash_net6_elem {
    union nf_inet_addr ip;
    u16 padding0;
    u8 nomatch;
    u8 cidr;
};

struct hash_net6_telem {
    union nf_inet_addr ip;
    u16 padding0;
    u8 nomatch;
    u8 cidr;
    unsigned long timeout;
};

static inline bool
hash_net6_data_equal(const struct hash_net6_elem *ip1,
             const struct hash_net6_elem *ip2,
             u32 *multi)
{
    return ipv6_addr_cmp(&ip1->ip.in6, &ip2->ip.in6) == 0 &&
           ip1->cidr == ip2->cidr;
}

static inline bool
hash_net6_data_isnull(const struct hash_net6_elem *elem)
{
    return elem->cidr == 0;
}

static inline void
hash_net6_data_copy(struct hash_net6_elem *dst,
            const struct hash_net6_elem *src)
{
    dst->ip.in6 = src->ip.in6;
    dst->cidr = src->cidr;
    dst->nomatch = src->nomatch;
}

static inline void
hash_net6_data_flags(struct hash_net6_elem *dst, u32 flags)
{
    dst->nomatch = flags & IPSET_FLAG_NOMATCH;
}

static inline int
hash_net6_data_match(const struct hash_net6_elem *elem)
{
    return elem->nomatch ? -ENOTEMPTY : 1;
}

static inline void
hash_net6_data_zero_out(struct hash_net6_elem *elem)
{
    elem->cidr = 0;
}

static inline void
ip6_netmask(union nf_inet_addr *ip, u8 prefix)
{
    ip->ip6[0] &= ip_set_netmask6(prefix)[0];
    ip->ip6[1] &= ip_set_netmask6(prefix)[1];
    ip->ip6[2] &= ip_set_netmask6(prefix)[2];
    ip->ip6[3] &= ip_set_netmask6(prefix)[3];
}

static inline void
hash_net6_data_netmask(struct hash_net6_elem *elem, u8 cidr)
{
    ip6_netmask(&elem->ip, cidr);
    elem->cidr = cidr;
}

static bool
hash_net6_data_list(struct sk_buff *skb, const struct hash_net6_elem *data)
{
    u32 flags = data->nomatch ? IPSET_FLAG_NOMATCH : 0;

    if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &data->ip.in6) ||
        nla_put_u8(skb, IPSET_ATTR_CIDR, data->cidr) ||
        (flags &&
         nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
        goto nla_put_failure;
    return 0;

nla_put_failure:
    return 1;
}

static bool
hash_net6_data_tlist(struct sk_buff *skb, const struct hash_net6_elem *data)
{
    const struct hash_net6_telem *e =
        (const struct hash_net6_telem *)data;
    u32 flags = data->nomatch ? IPSET_FLAG_NOMATCH : 0;

    if (nla_put_ipaddr6(skb, IPSET_ATTR_IP, &e->ip.in6) ||
        nla_put_u8(skb, IPSET_ATTR_CIDR, e->cidr) ||
        nla_put_net32(skb, IPSET_ATTR_TIMEOUT,
              htonl(ip_set_timeout_get(e->timeout))) ||
        (flags &&
         nla_put_net32(skb, IPSET_ATTR_CADT_FLAGS, htonl(flags))))
        goto nla_put_failure;
    return 0;

nla_put_failure:
    return 1;
}

#undef PF
#undef HOST_MASK

#define PF      6
#define HOST_MASK   128
#include <linux/netfilter/ipset/ip_set_ahash.h>

static inline void
hash_net6_data_next(struct ip_set_hash *h,
            const struct hash_net6_elem *d)
{
}

static int
hash_net6_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)
{
    const struct ip_set_hash *h = set->data;
    ipset_adtfn adtfn = set->variant->adt[adt];
    struct hash_net6_elem data = {
        .cidr = h->nets[0].cidr ? h->nets[0].cidr : HOST_MASK
    };

    if (data.cidr == 0)
        return -EINVAL;
    if (adt == IPSET_TEST)
        data.cidr = HOST_MASK;

    ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &data.ip.in6);
    ip6_netmask(&data.ip, data.cidr);

    return adtfn(set, &data, opt_timeout(opt, h), opt->cmdflags);
}

static int
hash_net6_uadt(struct ip_set *set, struct nlattr *tb[],
           enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
{
    const struct ip_set_hash *h = set->data;
    ipset_adtfn adtfn = set->variant->adt[adt];
    struct hash_net6_elem data = { .cidr = HOST_MASK };
    u32 timeout = h->timeout;
    int ret;

    if (unlikely(!tb[IPSET_ATTR_IP] ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT) ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_CADT_FLAGS)))
        return -IPSET_ERR_PROTOCOL;
    if (unlikely(tb[IPSET_ATTR_IP_TO]))
        return -IPSET_ERR_HASH_RANGE_UNSUPPORTED;

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

    ret = ip_set_get_ipaddr6(tb[IPSET_ATTR_IP], &data.ip);
    if (ret)
        return ret;

    if (tb[IPSET_ATTR_CIDR])
        data.cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);

    if (!data.cidr || data.cidr > HOST_MASK)
        return -IPSET_ERR_INVALID_CIDR;

    ip6_netmask(&data.ip, data.cidr);

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

    if (tb[IPSET_ATTR_CADT_FLAGS] && adt == IPSET_ADD) {
        u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
        if (cadt_flags & IPSET_FLAG_NOMATCH)
            flags |= (cadt_flags << 16);
    }

    ret = adtfn(set, &data, timeout, flags);

    return ip_set_eexist(ret, flags) ? 0 : ret;
}

/* Create hash:ip type of sets */

static int
hash_net_create(struct ip_set *set, struct nlattr *tb[], u32 flags)
{
    u32 hashsize = IPSET_DEFAULT_HASHSIZE, maxelem = IPSET_DEFAULT_MAXELEM;
    struct ip_set_hash *h;
    u8 hbits;
    size_t hsize;

    if (!(set->family == NFPROTO_IPV4 || set->family == NFPROTO_IPV6))
        return -IPSET_ERR_INVALID_FAMILY;

    if (unlikely(!ip_set_optattr_netorder(tb, IPSET_ATTR_HASHSIZE) ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_MAXELEM) ||
             !ip_set_optattr_netorder(tb, IPSET_ATTR_TIMEOUT)))
        return -IPSET_ERR_PROTOCOL;

    if (tb[IPSET_ATTR_HASHSIZE]) {
        hashsize = ip_set_get_h32(tb[IPSET_ATTR_HASHSIZE]);
        if (hashsize < IPSET_MIMINAL_HASHSIZE)
            hashsize = IPSET_MIMINAL_HASHSIZE;
    }

    if (tb[IPSET_ATTR_MAXELEM])
        maxelem = ip_set_get_h32(tb[IPSET_ATTR_MAXELEM]);

    h = kzalloc(sizeof(*h)
            + sizeof(struct ip_set_hash_nets)
              * (set->family == NFPROTO_IPV4 ? 32 : 128), GFP_KERNEL);
    if (!h)
        return -ENOMEM;

    h->maxelem = maxelem;
    get_random_bytes(&h->initval, sizeof(h->initval));
    h->timeout = IPSET_NO_TIMEOUT;

    hbits = htable_bits(hashsize);
    hsize = htable_size(hbits);
    if (hsize == 0) {
        kfree(h);
        return -ENOMEM;
    }
    h->table = ip_set_alloc(hsize);
    if (!h->table) {
        kfree(h);
        return -ENOMEM;
    }
    h->table->htable_bits = hbits;

    set->data = h;

    if (tb[IPSET_ATTR_TIMEOUT]) {
        h->timeout = ip_set_timeout_uget(tb[IPSET_ATTR_TIMEOUT]);

        set->variant = set->family == NFPROTO_IPV4
            ? &hash_net4_tvariant : &hash_net6_tvariant;

        if (set->family == NFPROTO_IPV4)
            hash_net4_gc_init(set);
        else
            hash_net6_gc_init(set);
    } else {
        set->variant = set->family == NFPROTO_IPV4
            ? &hash_net4_variant : &hash_net6_variant;
    }

    pr_debug("create %s hashsize %u (%u) maxelem %u: %p(%p)\n",
         set->name, jhash_size(h->table->htable_bits),
         h->table->htable_bits, h->maxelem, set->data, h->table);

    return 0;
}

static struct ip_set_type hash_net_type __read_mostly = {
    .name       = "hash:net",
    .protocol   = IPSET_PROTOCOL,
    .features   = IPSET_TYPE_IP | IPSET_TYPE_NOMATCH,
    .dimension  = IPSET_DIM_ONE,
    .family     = NFPROTO_UNSPEC,
    .revision_min   = REVISION_MIN,
    .revision_max   = REVISION_MAX,
    .create     = hash_net_create,
    .create_policy  = {
        [IPSET_ATTR_HASHSIZE]   = { .type = NLA_U32 },
        [IPSET_ATTR_MAXELEM]    = { .type = NLA_U32 },
        [IPSET_ATTR_PROBES] = { .type = NLA_U8 },
        [IPSET_ATTR_RESIZE] = { .type = NLA_U8  },
        [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
    },
    .adt_policy = {
        [IPSET_ATTR_IP]     = { .type = NLA_NESTED },
        [IPSET_ATTR_IP_TO]  = { .type = NLA_NESTED },
        [IPSET_ATTR_CIDR]   = { .type = NLA_U8 },
        [IPSET_ATTR_TIMEOUT]    = { .type = NLA_U32 },
        [IPSET_ATTR_CADT_FLAGS] = { .type = NLA_U32 },
    },
    .me     = THIS_MODULE,
};

static int __init
hash_net_init(void)
{
    return ip_set_type_register(&hash_net_type);
}

static void __exit
hash_net_fini(void)
{
    ip_set_type_unregister(&hash_net_type);
}

module_init(hash_net_init);
module_exit(hash_net_fini);