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. */
29 struct 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. */
37 struct 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 
78 struct nf_conntrack_tuple_mask {
79 	struct {
80 		union nf_inet_addr u3;
81 		union nf_conntrack_man_proto u;
82 	} src;
83 };
84 
85 static 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 
95 static 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 
105 static 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 */
122 struct nf_conntrack_tuple_hash {
123 	struct hlist_nulls_node hnnode;
124 	struct nf_conntrack_tuple tuple;
125 };
126 
127 static 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 
135 static 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 
143 static 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 
150 static inline bool
151 nf_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 
158 static inline bool
159 nf_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 
181 static inline bool
182 nf_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 */
191