/*------------------------------------------------------------------------- * * pqcomm.h * Definitions common to frontends and backends. * * NOTE: for historical reasons, this does not correspond to pqcomm.c. * pqcomm.c's routines are declared in libpq.h. * * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * src/include/libpq/pqcomm.h * *------------------------------------------------------------------------- */ #ifndef PQCOMM_H #define PQCOMM_H #include #include #ifdef HAVE_SYS_UN_H #include #endif #include #ifdef HAVE_STRUCT_SOCKADDR_STORAGE #ifndef HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY #ifdef HAVE_STRUCT_SOCKADDR_STORAGE___SS_FAMILY #define ss_family __ss_family #else #error struct sockaddr_storage does not provide an ss_family member #endif #endif #ifdef HAVE_STRUCT_SOCKADDR_STORAGE___SS_LEN #define ss_len __ss_len #define HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN 1 #endif #else /* !HAVE_STRUCT_SOCKADDR_STORAGE */ /* Define a struct sockaddr_storage if we don't have one. */ struct sockaddr_storage { union { struct sockaddr sa; /* get the system-dependent fields */ int64 ss_align; /* ensures struct is properly aligned */ char ss_pad[128]; /* ensures struct has desired size */ } ss_stuff; }; #define ss_family ss_stuff.sa.sa_family /* It should have an ss_len field if sockaddr has sa_len. */ #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN #define ss_len ss_stuff.sa.sa_len #define HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN 1 #endif #endif /* HAVE_STRUCT_SOCKADDR_STORAGE */ typedef struct { struct sockaddr_storage addr; ACCEPT_TYPE_ARG3 salen; } SockAddr; /* Configure the UNIX socket location for the well known port. */ #define UNIXSOCK_PATH(path, port, sockdir) \ snprintf(path, sizeof(path), "%s/.s.PGSQL.%d", \ ((sockdir) && *(sockdir) != '\0') ? (sockdir) : \ DEFAULT_PGSOCKET_DIR, \ (port)) /* * The maximum workable length of a socket path is what will fit into * struct sockaddr_un. This is usually only 100 or so bytes :-(. * * For consistency, always pass a MAXPGPATH-sized buffer to UNIXSOCK_PATH(), * then complain if the resulting string is >= UNIXSOCK_PATH_BUFLEN bytes. * (Because the standard API for getaddrinfo doesn't allow it to complain in * a useful way when the socket pathname is too long, we have to test for * this explicitly, instead of just letting the subroutine return an error.) */ #define UNIXSOCK_PATH_BUFLEN sizeof(((struct sockaddr_un *) NULL)->sun_path) /* * These manipulate the frontend/backend protocol version number. * * The major number should be incremented for incompatible changes. The minor * number should be incremented for compatible changes (eg. additional * functionality). * * If a backend supports version m.n of the protocol it must actually support * versions m.[0..n]. Backend support for version m-1 can be dropped after a * `reasonable' length of time. * * A frontend isn't required to support anything other than the current * version. */ #define PG_PROTOCOL_MAJOR(v) ((v) >> 16) #define PG_PROTOCOL_MINOR(v) ((v) & 0x0000ffff) #define PG_PROTOCOL(m,n) (((m) << 16) | (n)) /* The earliest and latest frontend/backend protocol version supported. */ #define PG_PROTOCOL_EARLIEST PG_PROTOCOL(2,0) #define PG_PROTOCOL_LATEST PG_PROTOCOL(3,0) typedef uint32 ProtocolVersion; /* FE/BE protocol version number */ typedef ProtocolVersion MsgType; /* * Packet lengths are 4 bytes in network byte order. * * The initial length is omitted from the packet layouts appearing below. */ typedef uint32 PacketLen; /* * Old-style startup packet layout with fixed-width fields. This is used in * protocol 1.0 and 2.0, but not in later versions. Note that the fields * in this layout are '\0' terminated only if there is room. */ #define SM_DATABASE 64 #define SM_USER 32 /* We append database name if db_user_namespace true. */ #define SM_DATABASE_USER (SM_DATABASE+SM_USER+1) /* +1 for @ */ #define SM_OPTIONS 64 #define SM_UNUSED 64 #define SM_TTY 64 typedef struct StartupPacket { ProtocolVersion protoVersion; /* Protocol version */ char database[SM_DATABASE]; /* Database name */ /* Db_user_namespace appends dbname */ char user[SM_USER]; /* User name */ char options[SM_OPTIONS]; /* Optional additional args */ char unused[SM_UNUSED]; /* Unused */ char tty[SM_TTY]; /* Tty for debug output */ } StartupPacket; extern bool Db_user_namespace; /* * In protocol 3.0 and later, the startup packet length is not fixed, but * we set an arbitrary limit on it anyway. This is just to prevent simple * denial-of-service attacks via sending enough data to run the server * out of memory. */ #define MAX_STARTUP_PACKET_LENGTH 10000 /* These are the authentication request codes sent by the backend. */ #define AUTH_REQ_OK 0 /* User is authenticated */ #define AUTH_REQ_KRB4 1 /* Kerberos V4. Not supported any more. */ #define AUTH_REQ_KRB5 2 /* Kerberos V5. Not supported any more. */ #define AUTH_REQ_PASSWORD 3 /* Password */ #define AUTH_REQ_CRYPT 4 /* crypt password. Not supported any more. */ #define AUTH_REQ_MD5 5 /* md5 password */ #define AUTH_REQ_SCM_CREDS 6 /* transfer SCM credentials */ #define AUTH_REQ_GSS 7 /* GSSAPI without wrap() */ #define AUTH_REQ_GSS_CONT 8 /* Continue GSS exchanges */ #define AUTH_REQ_SSPI 9 /* SSPI negotiate without wrap() */ #define AUTH_REQ_SASL 10 /* Begin SASL authentication */ #define AUTH_REQ_SASL_CONT 11 /* Continue SASL authentication */ #define AUTH_REQ_SASL_FIN 12 /* Final SASL message */ typedef uint32 AuthRequest; /* * A client can also send a cancel-current-operation request to the postmaster. * This is uglier than sending it directly to the client's backend, but it * avoids depending on out-of-band communication facilities. * * The cancel request code must not match any protocol version number * we're ever likely to use. This random choice should do. */ #define CANCEL_REQUEST_CODE PG_PROTOCOL(1234,5678) typedef struct CancelRequestPacket { /* Note that each field is stored in network byte order! */ MsgType cancelRequestCode; /* code to identify a cancel request */ uint32 backendPID; /* PID of client's backend */ uint32 cancelAuthCode; /* secret key to authorize cancel */ } CancelRequestPacket; /* * A client can also start by sending a SSL or GSSAPI negotiation request to * get a secure channel. */ #define NEGOTIATE_SSL_CODE PG_PROTOCOL(1234,5679) #define NEGOTIATE_GSS_CODE PG_PROTOCOL(1234,5680) #endif /* PQCOMM_H */