Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * pqcomm.h
4 : : * Definitions common to frontends and backends.
5 : : *
6 : : * NOTE: for historical reasons, this does not correspond to pqcomm.c.
7 : : * pqcomm.c's routines are declared in libpq.h.
8 : : *
9 : : * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
10 : : * Portions Copyright (c) 1994, Regents of the University of California
11 : : *
12 : : * src/include/libpq/pqcomm.h
13 : : *
14 : : *-------------------------------------------------------------------------
15 : : */
16 : : #ifndef PQCOMM_H
17 : : #define PQCOMM_H
18 : :
19 : : #include <sys/socket.h>
20 : : #include <sys/un.h>
21 : : #include <netdb.h>
22 : : #include <netinet/in.h>
23 : :
24 : : /*
25 : : * The definitions for the request/response codes are kept in a separate file
26 : : * for ease of use in third party programs.
27 : : */
28 : : #include "libpq/protocol.h"
29 : :
30 : : typedef struct
31 : : {
32 : : struct sockaddr_storage addr;
33 : : socklen_t salen;
34 : : } SockAddr;
35 : :
36 : : typedef struct
37 : : {
38 : : int family;
39 : : SockAddr addr;
40 : : } AddrInfo;
41 : :
42 : : /* Configure the UNIX socket location for the well known port. */
43 : :
44 : : #define UNIXSOCK_PATH(path, port, sockdir) \
45 : : (AssertMacro(sockdir), \
46 : : AssertMacro(*(sockdir) != '\0'), \
47 : : snprintf(path, sizeof(path), "%s/.s.PGSQL.%d", \
48 : : (sockdir), (port)))
49 : :
50 : : /*
51 : : * The maximum workable length of a socket path is what will fit into
52 : : * struct sockaddr_un. This is usually only 100 or so bytes :-(.
53 : : *
54 : : * For consistency, always pass a MAXPGPATH-sized buffer to UNIXSOCK_PATH(),
55 : : * then complain if the resulting string is >= UNIXSOCK_PATH_BUFLEN bytes.
56 : : * (Because the standard API for getaddrinfo doesn't allow it to complain in
57 : : * a useful way when the socket pathname is too long, we have to test for
58 : : * this explicitly, instead of just letting the subroutine return an error.)
59 : : */
60 : : #define UNIXSOCK_PATH_BUFLEN sizeof(((struct sockaddr_un *) NULL)->sun_path)
61 : :
62 : : /*
63 : : * A host that looks either like an absolute path or starts with @ is
64 : : * interpreted as a Unix-domain socket address.
65 : : */
66 : : static inline bool
1236 peter@eisentraut.org 67 :CBC 23787 : is_unixsock_path(const char *path)
68 : : {
69 [ + + - + ]: 23787 : return is_absolute_path(path) || path[0] == '@';
70 : : }
71 : :
72 : : /*
73 : : * These manipulate the frontend/backend protocol version number.
74 : : *
75 : : * The major number should be incremented for incompatible changes. The minor
76 : : * number should be incremented for compatible changes (eg. additional
77 : : * functionality).
78 : : *
79 : : * If a backend supports version m.n of the protocol it must actually support
80 : : * versions m.[0..n]. Backend support for version m-1 can be dropped after a
81 : : * `reasonable' length of time.
82 : : *
83 : : * A frontend isn't required to support anything other than the current
84 : : * version.
85 : : */
86 : :
87 : : #define PG_PROTOCOL_MAJOR(v) ((v) >> 16)
88 : : #define PG_PROTOCOL_MINOR(v) ((v) & 0x0000ffff)
89 : : #define PG_PROTOCOL(m,n) (((m) << 16) | (n))
90 : :
91 : : /*
92 : : * The earliest and latest frontend/backend protocol version supported.
93 : : * (Only protocol version 3 is currently supported)
94 : : */
95 : :
96 : : #define PG_PROTOCOL_EARLIEST PG_PROTOCOL(3,0)
97 : : #define PG_PROTOCOL_LATEST PG_PROTOCOL(3,0)
98 : :
99 : : typedef uint32 ProtocolVersion; /* FE/BE protocol version number */
100 : :
101 : : typedef ProtocolVersion MsgType;
102 : :
103 : :
104 : : /*
105 : : * Packet lengths are 4 bytes in network byte order.
106 : : *
107 : : * The initial length is omitted from the packet layouts appearing below.
108 : : */
109 : :
110 : : typedef uint32 PacketLen;
111 : :
112 : : /*
113 : : * In protocol 3.0 and later, the startup packet length is not fixed, but
114 : : * we set an arbitrary limit on it anyway. This is just to prevent simple
115 : : * denial-of-service attacks via sending enough data to run the server
116 : : * out of memory.
117 : : */
118 : : #define MAX_STARTUP_PACKET_LENGTH 10000
119 : :
120 : :
121 : : typedef uint32 AuthRequest;
122 : :
123 : :
124 : : /*
125 : : * A client can also send a cancel-current-operation request to the postmaster.
126 : : * This is uglier than sending it directly to the client's backend, but it
127 : : * avoids depending on out-of-band communication facilities.
128 : : *
129 : : * The cancel request code must not match any protocol version number
130 : : * we're ever likely to use. This random choice should do.
131 : : */
132 : : #define CANCEL_REQUEST_CODE PG_PROTOCOL(1234,5678)
133 : :
134 : : typedef struct CancelRequestPacket
135 : : {
136 : : /* Note that each field is stored in network byte order! */
137 : : MsgType cancelRequestCode; /* code to identify a cancel request */
138 : : uint32 backendPID; /* PID of client's backend */
139 : : uint32 cancelAuthCode; /* secret key to authorize cancel */
140 : : } CancelRequestPacket;
141 : :
142 : : /* Application-Layer Protocol Negotiation is required for direct connections
143 : : * to avoid protocol confusion attacks (e.g https://alpaca-attack.com/).
144 : : *
145 : : * ALPN is specified in RFC 7301
146 : : *
147 : : * This string should be registered at:
148 : : * https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml#alpn-protocol-ids
149 : : *
150 : : * OpenSSL uses this wire-format for the list of alpn protocols even in the
151 : : * API. Both server and client take the same format parameter but the client
152 : : * actually sends it to the server as-is and the server it specifies the
153 : : * preference order to use to choose the one selected to send back.
154 : : *
155 : : * c.f. https://www.openssl.org/docs/manmaster/man3/SSL_CTX_set_alpn_select_cb.html
156 : : *
157 : : * The #define can be used to initialize a char[] vector to use directly in the API
158 : : */
159 : : #define PG_ALPN_PROTOCOL "TBD-pgsql"
160 : : #define PG_ALPN_PROTOCOL_VECTOR { 9, 'T','B','D','-','p','g','s','q','l' }
161 : :
162 : : /*
163 : : * A client can also start by sending a SSL or GSSAPI negotiation request to
164 : : * get a secure channel.
165 : : */
166 : : #define NEGOTIATE_SSL_CODE PG_PROTOCOL(1234,5679)
167 : : #define NEGOTIATE_GSS_CODE PG_PROTOCOL(1234,5680)
168 : :
169 : : #endif /* PQCOMM_H */
|
