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inet.h
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1 /*-------------------------------------------------------------------------
2  *
3  * inet.h
4  * Declarations for operations on INET datatypes.
5  *
6  *
7  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/utils/inet.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef INET_H
15 #define INET_H
16 
17 #include "fmgr.h"
18 
19 /*
20  * This is the internal storage format for IP addresses
21  * (both INET and CIDR datatypes):
22  */
23 typedef struct
24 {
25  unsigned char family; /* PGSQL_AF_INET or PGSQL_AF_INET6 */
26  unsigned char bits; /* number of bits in netmask */
27  unsigned char ipaddr[16]; /* up to 128 bits of address */
28 } inet_struct;
29 
30 /*
31  * We use these values for the "family" field.
32  *
33  * Referencing all of the non-AF_INET types to AF_INET lets us work on
34  * machines which may not have the appropriate address family (like
35  * inet6 addresses when AF_INET6 isn't present) but doesn't cause a
36  * dump/reload requirement. Pre-7.4 databases used AF_INET for the family
37  * type on disk.
38  */
39 #define PGSQL_AF_INET (AF_INET + 0)
40 #define PGSQL_AF_INET6 (AF_INET + 1)
41 
42 /*
43  * Both INET and CIDR addresses are represented within Postgres as varlena
44  * objects, ie, there is a varlena header in front of the struct type
45  * depicted above. This struct depicts what we actually have in memory
46  * in "uncompressed" cases. Note that since the maximum data size is only
47  * 18 bytes, INET/CIDR will invariably be stored into tuples using the
48  * 1-byte-header varlena format. However, we have to be prepared to cope
49  * with the 4-byte-header format too, because various code may helpfully
50  * try to "decompress" 1-byte-header datums.
51  */
52 typedef struct
53 {
54  char vl_len_[4]; /* Do not touch this field directly! */
56 } inet;
57 
58 /*
59  * Access macros. We use VARDATA_ANY so that we can process short-header
60  * varlena values without detoasting them. This requires a trick:
61  * VARDATA_ANY assumes the varlena header is already filled in, which is
62  * not the case when constructing a new value (until SET_INET_VARSIZE is
63  * called, which we typically can't do till the end). Therefore, we
64  * always initialize the newly-allocated value to zeroes (using palloc0).
65  * A zero length word will look like the not-1-byte case to VARDATA_ANY,
66  * and so we correctly construct an uncompressed value.
67  *
68  * Note that ip_addrsize(), ip_maxbits(), and SET_INET_VARSIZE() require
69  * the family field to be set correctly.
70  */
71 #define ip_family(inetptr) \
72  (((inet_struct *) VARDATA_ANY(inetptr))->family)
73 
74 #define ip_bits(inetptr) \
75  (((inet_struct *) VARDATA_ANY(inetptr))->bits)
76 
77 #define ip_addr(inetptr) \
78  (((inet_struct *) VARDATA_ANY(inetptr))->ipaddr)
79 
80 #define ip_addrsize(inetptr) \
81  (ip_family(inetptr) == PGSQL_AF_INET ? 4 : 16)
82 
83 #define ip_maxbits(inetptr) \
84  (ip_family(inetptr) == PGSQL_AF_INET ? 32 : 128)
85 
86 #define SET_INET_VARSIZE(dst) \
87  SET_VARSIZE(dst, VARHDRSZ + offsetof(inet_struct, ipaddr) + \
88  ip_addrsize(dst))
89 
90 
91 /*
92  * This is the internal storage format for MAC addresses:
93  */
94 typedef struct macaddr
95 {
96  unsigned char a;
97  unsigned char b;
98  unsigned char c;
99  unsigned char d;
100  unsigned char e;
101  unsigned char f;
102 } macaddr;
103 
104 /*
105  * This is the internal storage format for MAC8 addresses:
106  */
107 typedef struct macaddr8
108 {
109  unsigned char a;
110  unsigned char b;
111  unsigned char c;
112  unsigned char d;
113  unsigned char e;
114  unsigned char f;
115  unsigned char g;
116  unsigned char h;
117 } macaddr8;
118 
119 /*
120  * fmgr interface macros
121  */
122 #define DatumGetInetPP(X) ((inet *) PG_DETOAST_DATUM_PACKED(X))
123 #define InetPGetDatum(X) PointerGetDatum(X)
124 #define PG_GETARG_INET_PP(n) DatumGetInetPP(PG_GETARG_DATUM(n))
125 #define PG_RETURN_INET_P(x) return InetPGetDatum(x)
126 /* obsolescent variants */
127 #define DatumGetInetP(X) ((inet *) PG_DETOAST_DATUM(X))
128 #define PG_GETARG_INET_P(n) DatumGetInetP(PG_GETARG_DATUM(n))
129 
130 /* macaddr is a fixed-length pass-by-reference datatype */
131 #define DatumGetMacaddrP(X) ((macaddr *) DatumGetPointer(X))
132 #define MacaddrPGetDatum(X) PointerGetDatum(X)
133 #define PG_GETARG_MACADDR_P(n) DatumGetMacaddrP(PG_GETARG_DATUM(n))
134 #define PG_RETURN_MACADDR_P(x) return MacaddrPGetDatum(x)
135 
136 /* macaddr8 is a fixed-length pass-by-reference datatype */
137 #define DatumGetMacaddr8P(X) ((macaddr8 *) DatumGetPointer(X))
138 #define Macaddr8PGetDatum(X) PointerGetDatum(X)
139 #define PG_GETARG_MACADDR8_P(n) DatumGetMacaddr8P(PG_GETARG_DATUM(n))
140 #define PG_RETURN_MACADDR8_P(x) return Macaddr8PGetDatum(x)
141 
142 /*
143  * Support functions in network.c
144  */
145 extern inet *cidr_set_masklen_internal(const inet *src, int bits);
146 extern int bitncmp(const unsigned char *l, const unsigned char *r, int n);
147 extern int bitncommon(const unsigned char *l, const unsigned char *r, int n);
148 
149 #endif /* INET_H */
inet * cidr_set_masklen_internal(const inet *src, int bits)
Definition: network.c:327
unsigned char f
Definition: inet.h:101
unsigned char family
Definition: inet.h:25
struct macaddr8 macaddr8
unsigned char h
Definition: inet.h:116
unsigned char f
Definition: inet.h:114
unsigned char g
Definition: inet.h:115
struct macaddr macaddr
unsigned char c
Definition: inet.h:98
unsigned char a
Definition: inet.h:109
unsigned char a
Definition: inet.h:96
Definition: inet.h:107
unsigned char d
Definition: inet.h:99
inet_struct inet_data
Definition: inet.h:55
unsigned char b
Definition: inet.h:110
Definition: inet.h:52
unsigned char e
Definition: inet.h:113
unsigned char c
Definition: inet.h:111
unsigned char b
Definition: inet.h:97
unsigned char e
Definition: inet.h:100
int bitncmp(const unsigned char *l, const unsigned char *r, int n)
Definition: network.c:980
Definition: inet.h:94
unsigned char d
Definition: inet.h:112
int bitncommon(const unsigned char *l, const unsigned char *r, int n)
Definition: network.c:1014
unsigned char bits
Definition: inet.h:26