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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) 1996-2023, 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 67 41412 : is_unixsock_path(const char *path) 68 : { 69 41412 : 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 : 143 : /* 144 : * A client can also start by sending a SSL or GSSAPI negotiation request to 145 : * get a secure channel. 146 : */ 147 : #define NEGOTIATE_SSL_CODE PG_PROTOCOL(1234,5679) 148 : #define NEGOTIATE_GSS_CODE PG_PROTOCOL(1234,5680) 149 : 150 : #endif /* PQCOMM_H */