nf_conntrack_tuple.h

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/*
 * Definitions and Declarations for tuple.
 *
 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <[email protected]>
 *  - generalize L3 protocol dependent part.
 *
 * Derived from include/linux/netfiter_ipv4/ip_conntrack_tuple.h
 */

#ifndef _NF_CONNTRACK_TUPLE_H
#define _NF_CONNTRACK_TUPLE_H

#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/nf_conntrack_tuple_common.h>
#include <linux/list_nulls.h>

/* A `tuple' is a structure containing the information to uniquely
  identify a connection.  ie. if two packets have the same tuple, they
  are in the same connection; if not, they are not.

  We divide the structure along "manipulatable" and
  "non-manipulatable" lines, for the benefit of the NAT code.
*/

#define NF_CT_TUPLE_L3SIZE  ARRAY_SIZE(((union nf_inet_addr *)NULL)->all)

/* The manipulable part of the tuple. */
struct nf_conntrack_man {
    union nf_inet_addr u3;
    union nf_conntrack_man_proto u;
    /* Layer 3 protocol */
    u_int16_t l3num;
};

/* This contains the information to distinguish a connection. */
struct nf_conntrack_tuple {
    struct nf_conntrack_man src;

    /* These are the parts of the tuple which are fixed. */
    struct {
        union nf_inet_addr u3;
        union {
            /* Add other protocols here. */
            __be16 all;

            struct {
                __be16 port;
            } tcp;
            struct {
                __be16 port;
            } udp;
            struct {
                u_int8_t type, code;
            } icmp;
            struct {
                __be16 port;
            } dccp;
            struct {
                __be16 port;
            } sctp;
            struct {
                __be16 key;
            } gre;
        } u;

        /* The protocol. */
        u_int8_t protonum;

        /* The direction (for tuplehash) */
        u_int8_t dir;
    } dst;
};

struct nf_conntrack_tuple_mask {
    struct {
        union nf_inet_addr u3;
        union nf_conntrack_man_proto u;
    } src;
};

static inline void nf_ct_dump_tuple_ip(const struct nf_conntrack_tuple *t)
{
#ifdef DEBUG
    printk("tuple %p: %u %pI4:%hu -> %pI4:%hu\n",
           t, t->dst.protonum,
           &t->src.u3.ip, ntohs(t->src.u.all),
           &t->dst.u3.ip, ntohs(t->dst.u.all));
#endif
}

static inline void nf_ct_dump_tuple_ipv6(const struct nf_conntrack_tuple *t)
{
#ifdef DEBUG
    printk("tuple %p: %u %pI6 %hu -> %pI6 %hu\n",
           t, t->dst.protonum,
           t->src.u3.all, ntohs(t->src.u.all),
           t->dst.u3.all, ntohs(t->dst.u.all));
#endif
}

static inline void nf_ct_dump_tuple(const struct nf_conntrack_tuple *t)
{
    switch (t->src.l3num) {
    case AF_INET:
        nf_ct_dump_tuple_ip(t);
        break;
    case AF_INET6:
        nf_ct_dump_tuple_ipv6(t);
        break;
    }
}

/* If we're the first tuple, it's the original dir. */
#define NF_CT_DIRECTION(h)                      \
    ((enum ip_conntrack_dir)(h)->tuple.dst.dir)

/* Connections have two entries in the hash table: one for each way */
struct nf_conntrack_tuple_hash {
    struct hlist_nulls_node hnnode;
    struct nf_conntrack_tuple tuple;
};

static inline bool __nf_ct_tuple_src_equal(const struct nf_conntrack_tuple *t1,
                       const struct nf_conntrack_tuple *t2)
{ 
    return (nf_inet_addr_cmp(&t1->src.u3, &t2->src.u3) &&
        t1->src.u.all == t2->src.u.all &&
        t1->src.l3num == t2->src.l3num);
}

static inline bool __nf_ct_tuple_dst_equal(const struct nf_conntrack_tuple *t1,
                       const struct nf_conntrack_tuple *t2)
{
    return (nf_inet_addr_cmp(&t1->dst.u3, &t2->dst.u3) &&
        t1->dst.u.all == t2->dst.u.all &&
        t1->dst.protonum == t2->dst.protonum);
}

static inline bool nf_ct_tuple_equal(const struct nf_conntrack_tuple *t1,
                     const struct nf_conntrack_tuple *t2)
{
    return __nf_ct_tuple_src_equal(t1, t2) &&
           __nf_ct_tuple_dst_equal(t1, t2);
}

static inline bool
nf_ct_tuple_mask_equal(const struct nf_conntrack_tuple_mask *m1,
               const struct nf_conntrack_tuple_mask *m2)
{
    return (nf_inet_addr_cmp(&m1->src.u3, &m2->src.u3) &&
        m1->src.u.all == m2->src.u.all);
}

static inline bool
nf_ct_tuple_src_mask_cmp(const struct nf_conntrack_tuple *t1,
             const struct nf_conntrack_tuple *t2,
             const struct nf_conntrack_tuple_mask *mask)
{
    int count;

    for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++) {
        if ((t1->src.u3.all[count] ^ t2->src.u3.all[count]) &
            mask->src.u3.all[count])
            return false;
    }

    if ((t1->src.u.all ^ t2->src.u.all) & mask->src.u.all)
        return false;

    if (t1->src.l3num != t2->src.l3num ||
        t1->dst.protonum != t2->dst.protonum)
        return false;

    return true;
}

static inline bool
nf_ct_tuple_mask_cmp(const struct nf_conntrack_tuple *t,
             const struct nf_conntrack_tuple *tuple,
             const struct nf_conntrack_tuple_mask *mask)
{
    return nf_ct_tuple_src_mask_cmp(t, tuple, mask) &&
           __nf_ct_tuple_dst_equal(t, tuple);
}

#endif /* _NF_CONNTRACK_TUPLE_H */