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ip_set_ipportiphash.c

/* Copyright (C) 2008 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
 *
 * 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+port+ip hash set */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/skbuff.h>
#include "ip_set_jhash.h"
#include <linux/errno.h>
#include <asm/uaccess.h>
#include <asm/bitops.h>
#include <linux/spinlock.h>
#include <linux/random.h>

#include <net/ip.h>

#include "ip_set_ipportiphash.h"
#include "ip_set_getport.h"

static int limit = MAX_RANGE;

#define jhash_ip2(map, i, ipport, ip1)          \
      jhash_2words(ipport, ip1, *(map->initval + i))

static inline __u32
ipportiphash_id(struct ip_set *set,
            ip_set_ip_t ip, ip_set_ip_t port, ip_set_ip_t ip1)
{
      struct ip_set_ipportiphash *map = set->data;
      __u32 id;
      u_int16_t i;
      struct ipportip *elem;

      ip = pack_ip_port(map, ip, port);
      if (!(ip || ip1))
            return UINT_MAX;
      
      for (i = 0; i < map->probes; i++) {
            id = jhash_ip2(map, i, ip, ip1) % map->hashsize;
            DP("hash key: %u", id);
            elem = HARRAY_ELEM(map->members, struct ipportip *, id);
            if (elem->ip == ip && elem->ip1 == ip1)
                  return id;
            /* No shortcut - there can be deleted entries. */
      }
      return UINT_MAX;
}

static inline int
ipportiphash_test(struct ip_set *set,
              ip_set_ip_t ip, ip_set_ip_t port, ip_set_ip_t ip1)
{
      struct ip_set_ipportiphash *map = set->data;
      
      if (ip < map->first_ip || ip > map->last_ip)
            return -ERANGE;

      return (ipportiphash_id(set, ip, port, ip1) != UINT_MAX);
}

#define KADT_CONDITION                                \
      ip_set_ip_t port, ip1;                          \
                                                \
      if (flags[2] == 0)                              \
            return 0;                           \
                                                \
      port = get_port(skb, flags++);                        \
      ip1 = ipaddr(skb, flags++);                     \
                                                \
      if (port == INVALID_PORT)                       \
            return 0;

UADT(ipportiphash, test, req->port, req->ip1)
KADT(ipportiphash, test, ipaddr, port, ip1)

static inline int
__ipportip_add(struct ip_set_ipportiphash *map,
             ip_set_ip_t ip, ip_set_ip_t ip1)
{
      __u32 probe;
      u_int16_t i;
      struct ipportip *elem, *slot = NULL;

      for (i = 0; i < map->probes; i++) {
            probe = jhash_ip2(map, i, ip, ip1) % map->hashsize;
            elem = HARRAY_ELEM(map->members, struct ipportip *, probe);
            if (elem->ip == ip && elem->ip1 == ip1)
                  return -EEXIST;
            if (!(slot || elem->ip || elem->ip1))
                  slot = elem;
            /* There can be deleted entries, must check all slots */
      }
      if (slot) {
            slot->ip = ip;
            slot->ip1 = ip1;
            map->elements++;
            return 0;
      }
      /* Trigger rehashing */
      return -EAGAIN;
}

static inline int
__ipportiphash_add(struct ip_set_ipportiphash *map,
               struct ipportip *elem)
{
      return __ipportip_add(map, elem->ip, elem->ip1);
}

static inline int
ipportiphash_add(struct ip_set *set,
             ip_set_ip_t ip, ip_set_ip_t port, ip_set_ip_t ip1)
{
      struct ip_set_ipportiphash *map = set->data;
      
      if (map->elements > limit)
            return -ERANGE;
      if (ip < map->first_ip || ip > map->last_ip)
            return -ERANGE;

      ip = pack_ip_port(map, ip, port);
      if (!(ip || ip1))
            return -ERANGE;
      
      return __ipportip_add(map, ip, ip1);
}

UADT(ipportiphash, add, req->port, req->ip1)
KADT(ipportiphash, add, ipaddr, port, ip1)

static inline void
__ipportiphash_retry(struct ip_set_ipportiphash *tmp,
                 struct ip_set_ipportiphash *map)
{
      tmp->first_ip = map->first_ip;
      tmp->last_ip = map->last_ip;
}

HASH_RETRY2(ipportiphash, struct ipportip)

static inline int
ipportiphash_del(struct ip_set *set,
             ip_set_ip_t ip, ip_set_ip_t port, ip_set_ip_t ip1)
{
      struct ip_set_ipportiphash *map = set->data;
      ip_set_ip_t id;
      struct ipportip *elem;

      if (ip < map->first_ip || ip > map->last_ip)
            return -ERANGE;

      id = ipportiphash_id(set, ip, port, ip1);

      if (id == UINT_MAX)
            return -EEXIST;
            
      elem = HARRAY_ELEM(map->members, struct ipportip *, id);
      elem->ip = elem->ip1 = 0;
      map->elements--;

      return 0;
}

UADT(ipportiphash, del, req->port, req->ip1)
KADT(ipportiphash, del, ipaddr, port, ip1)

static inline int
__ipportiphash_create(const struct ip_set_req_ipportiphash_create *req,
                  struct ip_set_ipportiphash *map)
{
      if (req->to - req->from > MAX_RANGE) {
            ip_set_printk("range too big, %d elements (max %d)",
                        req->to - req->from + 1, MAX_RANGE+1);
            return -ENOEXEC;
      }
      map->first_ip = req->from;
      map->last_ip = req->to;
      return 0;
}

HASH_CREATE(ipportiphash, struct ipportip)
HASH_DESTROY(ipportiphash)
HASH_FLUSH(ipportiphash, struct ipportip)

static inline void
__ipportiphash_list_header(const struct ip_set_ipportiphash *map,
                     struct ip_set_req_ipportiphash_create *header)
{
      header->from = map->first_ip;
      header->to = map->last_ip;
}

HASH_LIST_HEADER(ipportiphash)
HASH_LIST_MEMBERS_SIZE(ipportiphash, struct ipportip)
HASH_LIST_MEMBERS_MEMCPY(ipportiphash, struct ipportip,
                   (elem->ip || elem->ip1))

IP_SET_RTYPE(ipportiphash, IPSET_TYPE_IP | IPSET_TYPE_PORT
                     | IPSET_TYPE_IP1 | IPSET_DATA_TRIPLE)

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
MODULE_DESCRIPTION("ipportiphash type of IP sets");
module_param(limit, int, 0600);
MODULE_PARM_DESC(limit, "maximal number of elements stored in the sets");

REGISTER_MODULE(ipportiphash)

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