Age         Owner                  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) 1996-2023, 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                 : typedef struct
 7188 bruce                      25 ECB             : {
                                 26                 :     struct sockaddr_storage addr;
                                 27                 :     socklen_t   salen;
                                 28                 : } SockAddr;
                                 29                 : 
                                 30                 : typedef struct
                                 31                 : {
                                 32                 :     int         family;
                                 33                 :     SockAddr    addr;
                                 34                 : } AddrInfo;
                                 35                 : 
                                 36                 : /* Configure the UNIX socket location for the well known port. */
                                 37                 : 
                                 38                 : #define UNIXSOCK_PATH(path, port, sockdir) \
                                 39                 :        (AssertMacro(sockdir), \
                                 40                 :         AssertMacro(*(sockdir) != '\0'), \
                                 41                 :         snprintf(path, sizeof(path), "%s/.s.PGSQL.%d", \
                                 42                 :                  (sockdir), (port)))
                                 43                 : 
                                 44                 : /*
                                 45                 :  * The maximum workable length of a socket path is what will fit into
                                 46                 :  * struct sockaddr_un.  This is usually only 100 or so bytes :-(.
                                 47                 :  *
                                 48                 :  * For consistency, always pass a MAXPGPATH-sized buffer to UNIXSOCK_PATH(),
                                 49                 :  * then complain if the resulting string is >= UNIXSOCK_PATH_BUFLEN bytes.
                                 50                 :  * (Because the standard API for getaddrinfo doesn't allow it to complain in
                                 51                 :  * a useful way when the socket pathname is too long, we have to test for
                                 52                 :  * this explicitly, instead of just letting the subroutine return an error.)
                                 53                 :  */
                                 54                 : #define UNIXSOCK_PATH_BUFLEN sizeof(((struct sockaddr_un *) NULL)->sun_path)
                                 55                 : 
                                 56                 : /*
                                 57                 :  * A host that looks either like an absolute path or starts with @ is
                                 58                 :  * interpreted as a Unix-domain socket address.
                                 59                 :  */
                                 60                 : static inline bool
  865 peter                      61 GIC       18475 : is_unixsock_path(const char *path)
                                 62                 : {
                                 63           18475 :     return is_absolute_path(path) || path[0] == '@';
                                 64                 : }
                                 65                 : 
                                 66                 : /*
                                 67                 :  * These manipulate the frontend/backend protocol version number.
                                 68                 :  *
                                 69                 :  * The major number should be incremented for incompatible changes.  The minor
                                 70                 :  * number should be incremented for compatible changes (eg. additional
                                 71                 :  * functionality).
                                 72                 :  *
                                 73                 :  * If a backend supports version m.n of the protocol it must actually support
                                 74                 :  * versions m.[0..n].  Backend support for version m-1 can be dropped after a
                                 75                 :  * `reasonable' length of time.
                                 76                 :  *
                                 77                 :  * A frontend isn't required to support anything other than the current
                                 78                 :  * version.
                                 79                 :  */
                                 80                 : 
                                 81                 : #define PG_PROTOCOL_MAJOR(v)    ((v) >> 16)
                                 82                 : #define PG_PROTOCOL_MINOR(v)    ((v) & 0x0000ffff)
                                 83                 : #define PG_PROTOCOL(m,n)    (((m) << 16) | (n))
                                 84                 : 
                                 85                 : /*
                                 86                 :  * The earliest and latest frontend/backend protocol version supported.
                                 87                 :  * (Only protocol version 3 is currently supported)
                                 88                 :  */
                                 89                 : 
                                 90                 : #define PG_PROTOCOL_EARLIEST    PG_PROTOCOL(3,0)
                                 91                 : #define PG_PROTOCOL_LATEST      PG_PROTOCOL(3,0)
                                 92                 : 
                                 93                 : typedef uint32 ProtocolVersion; /* FE/BE protocol version number */
                                 94                 : 
                                 95                 : typedef ProtocolVersion MsgType;
                                 96                 : 
                                 97                 : 
                                 98                 : /*
                                 99                 :  * Packet lengths are 4 bytes in network byte order.
                                100                 :  *
                                101                 :  * The initial length is omitted from the packet layouts appearing below.
                                102                 :  */
                                103                 : 
                                104                 : typedef uint32 PacketLen;
                                105                 : 
                                106                 : extern PGDLLIMPORT bool Db_user_namespace;
                                107                 : 
                                108                 : /*
                                109                 :  * In protocol 3.0 and later, the startup packet length is not fixed, but
                                110                 :  * we set an arbitrary limit on it anyway.  This is just to prevent simple
                                111                 :  * denial-of-service attacks via sending enough data to run the server
                                112                 :  * out of memory.
                                113                 :  */
                                114                 : #define MAX_STARTUP_PACKET_LENGTH 10000
                                115                 : 
                                116                 : 
                                117                 : /* These are the authentication request codes sent by the backend. */
                                118                 : 
                                119                 : #define AUTH_REQ_OK         0   /* User is authenticated  */
                                120                 : #define AUTH_REQ_KRB4       1   /* Kerberos V4. Not supported any more. */
                                121                 : #define AUTH_REQ_KRB5       2   /* Kerberos V5. Not supported any more. */
                                122                 : #define AUTH_REQ_PASSWORD   3   /* Password */
                                123                 : #define AUTH_REQ_CRYPT      4   /* crypt password. Not supported any more. */
                                124                 : #define AUTH_REQ_MD5        5   /* md5 password */
                                125                 : /* 6 is available.  It was used for SCM creds, not supported any more. */
                                126                 : #define AUTH_REQ_GSS        7   /* GSSAPI without wrap() */
                                127                 : #define AUTH_REQ_GSS_CONT   8   /* Continue GSS exchanges */
                                128                 : #define AUTH_REQ_SSPI       9   /* SSPI negotiate without wrap() */
                                129                 : #define AUTH_REQ_SASL      10   /* Begin SASL authentication */
                                130                 : #define AUTH_REQ_SASL_CONT 11   /* Continue SASL authentication */
                                131                 : #define AUTH_REQ_SASL_FIN  12   /* Final SASL message */
                                132                 : #define AUTH_REQ_MAX       AUTH_REQ_SASL_FIN    /* maximum AUTH_REQ_* value */
                                133                 : 
                                134                 : typedef uint32 AuthRequest;
                                135                 : 
                                136                 : 
                                137                 : /*
                                138                 :  * A client can also send a cancel-current-operation request to the postmaster.
                                139                 :  * This is uglier than sending it directly to the client's backend, but it
                                140                 :  * avoids depending on out-of-band communication facilities.
                                141                 :  *
                                142                 :  * The cancel request code must not match any protocol version number
                                143                 :  * we're ever likely to use.  This random choice should do.
                                144                 :  */
                                145                 : #define CANCEL_REQUEST_CODE PG_PROTOCOL(1234,5678)
                                146                 : 
                                147                 : typedef struct CancelRequestPacket
                                148                 : {
                                149                 :     /* Note that each field is stored in network byte order! */
                                150                 :     MsgType     cancelRequestCode;  /* code to identify a cancel request */
                                151                 :     uint32      backendPID;     /* PID of client's backend */
                                152                 :     uint32      cancelAuthCode; /* secret key to authorize cancel */
                                153                 : } CancelRequestPacket;
                                154                 : 
                                155                 : 
                                156                 : /*
                                157                 :  * A client can also start by sending a SSL or GSSAPI negotiation request to
                                158                 :  * get a secure channel.
                                159                 :  */
                                160                 : #define NEGOTIATE_SSL_CODE PG_PROTOCOL(1234,5679)
                                161                 : #define NEGOTIATE_GSS_CODE PG_PROTOCOL(1234,5680)
                                162                 : 
                                163                 : #endif                          /* PQCOMM_H */