nf_conntrack_tuple.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Definitions and Declarations for tuple.
  4 *
  5 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
  6 *	- generalize L3 protocol dependent part.
  7 *
  8 * Derived from include/linux/netfiter_ipv4/ip_conntrack_tuple.h
  9 */
 10
 11#ifndef _NF_CONNTRACK_TUPLE_H
 12#define _NF_CONNTRACK_TUPLE_H
 13
 14#include <linux/netfilter/x_tables.h>
 15#include <linux/netfilter/nf_conntrack_tuple_common.h>
 16#include <linux/list_nulls.h>
 17
 18/* A `tuple' is a structure containing the information to uniquely
 19  identify a connection.  ie. if two packets have the same tuple, they
 20  are in the same connection; if not, they are not.
 21
 22  We divide the structure along "manipulatable" and
 23  "non-manipulatable" lines, for the benefit of the NAT code.
 24*/
 25
 26#define NF_CT_TUPLE_L3SIZE	ARRAY_SIZE(((union nf_inet_addr *)NULL)->all)
 27
 28/* The manipulable part of the tuple. */
 29struct nf_conntrack_man {
 30	union nf_inet_addr u3;
 31	union nf_conntrack_man_proto u;
 32	/* Layer 3 protocol */
 33	u_int16_t l3num;
 34};
 35
 36/* This contains the information to distinguish a connection. */
 37struct nf_conntrack_tuple {
 38	struct nf_conntrack_man src;
 39
 40	/* These are the parts of the tuple which are fixed. */
 41	struct {
 42		union nf_inet_addr u3;
 43		union {
 44			/* Add other protocols here. */
 45			__be16 all;
 46
 47			struct {
 48				__be16 port;
 49			} tcp;
 50			struct {
 51				__be16 port;
 52			} udp;
 53			struct {
 54				u_int8_t type, code;
 55			} icmp;
 56			struct {
 57				__be16 port;
 58			} dccp;
 59			struct {
 60				__be16 port;
 61			} sctp;
 62			struct {
 63				__be16 key;
 64			} gre;
 65		} u;
 66
 67		/* The protocol. */
 68		u_int8_t protonum;
 69
 70		/* The direction must be ignored for the tuplehash */
 71		struct { } __nfct_hash_offsetend;
 72
 73		/* The direction (for tuplehash) */
 74		u_int8_t dir;
 75	} dst;
 76};
 77
 78struct nf_conntrack_tuple_mask {
 79	struct {
 80		union nf_inet_addr u3;
 81		union nf_conntrack_man_proto u;
 82	} src;
 83};
 84
 85static inline void nf_ct_dump_tuple_ip(const struct nf_conntrack_tuple *t)
 86{
 87#ifdef DEBUG
 88	printk("tuple %p: %u %pI4:%hu -> %pI4:%hu\n",
 89	       t, t->dst.protonum,
 90	       &t->src.u3.ip, ntohs(t->src.u.all),
 91	       &t->dst.u3.ip, ntohs(t->dst.u.all));
 92#endif
 93}
 94
 95static inline void nf_ct_dump_tuple_ipv6(const struct nf_conntrack_tuple *t)
 96{
 97#ifdef DEBUG
 98	printk("tuple %p: %u %pI6 %hu -> %pI6 %hu\n",
 99	       t, t->dst.protonum,
100	       t->src.u3.all, ntohs(t->src.u.all),
101	       t->dst.u3.all, ntohs(t->dst.u.all));
102#endif
103}
104
105static inline void nf_ct_dump_tuple(const struct nf_conntrack_tuple *t)
106{
107	switch (t->src.l3num) {
108	case AF_INET:
109		nf_ct_dump_tuple_ip(t);
110		break;
111	case AF_INET6:
112		nf_ct_dump_tuple_ipv6(t);
113		break;
114	}
115}
116
117/* If we're the first tuple, it's the original dir. */
118#define NF_CT_DIRECTION(h)						\
119	((enum ip_conntrack_dir)(h)->tuple.dst.dir)
120
121/* Connections have two entries in the hash table: one for each way */
122struct nf_conntrack_tuple_hash {
123	struct hlist_nulls_node hnnode;
124	struct nf_conntrack_tuple tuple;
125};
126
127static inline bool __nf_ct_tuple_src_equal(const struct nf_conntrack_tuple *t1,
128					   const struct nf_conntrack_tuple *t2)
129{
130	return (nf_inet_addr_cmp(&t1->src.u3, &t2->src.u3) &&
131		t1->src.u.all == t2->src.u.all &&
132		t1->src.l3num == t2->src.l3num);
133}
134
135static inline bool __nf_ct_tuple_dst_equal(const struct nf_conntrack_tuple *t1,
136					   const struct nf_conntrack_tuple *t2)
137{
138	return (nf_inet_addr_cmp(&t1->dst.u3, &t2->dst.u3) &&
139		t1->dst.u.all == t2->dst.u.all &&
140		t1->dst.protonum == t2->dst.protonum);
141}
142
143static inline bool nf_ct_tuple_equal(const struct nf_conntrack_tuple *t1,
144				     const struct nf_conntrack_tuple *t2)
145{
146	return __nf_ct_tuple_src_equal(t1, t2) &&
147	       __nf_ct_tuple_dst_equal(t1, t2);
148}
149
150static inline bool
151nf_ct_tuple_mask_equal(const struct nf_conntrack_tuple_mask *m1,
152		       const struct nf_conntrack_tuple_mask *m2)
153{
154	return (nf_inet_addr_cmp(&m1->src.u3, &m2->src.u3) &&
155		m1->src.u.all == m2->src.u.all);
156}
157
158static inline bool
159nf_ct_tuple_src_mask_cmp(const struct nf_conntrack_tuple *t1,
160			 const struct nf_conntrack_tuple *t2,
161			 const struct nf_conntrack_tuple_mask *mask)
162{
163	int count;
164
165	for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++) {
166		if ((t1->src.u3.all[count] ^ t2->src.u3.all[count]) &
167		    mask->src.u3.all[count])
168			return false;
169	}
170
171	if ((t1->src.u.all ^ t2->src.u.all) & mask->src.u.all)
172		return false;
173
174	if (t1->src.l3num != t2->src.l3num ||
175	    t1->dst.protonum != t2->dst.protonum)
176		return false;
177
178	return true;
179}
180
181static inline bool
182nf_ct_tuple_mask_cmp(const struct nf_conntrack_tuple *t,
183		     const struct nf_conntrack_tuple *tuple,
184		     const struct nf_conntrack_tuple_mask *mask)
185{
186	return nf_ct_tuple_src_mask_cmp(t, tuple, mask) &&
187	       __nf_ct_tuple_dst_equal(t, tuple);
188}
189
190#endif /* _NF_CONNTRACK_TUPLE_H */