#include <sys/socket.h>
#include <sys/un.h>
#include <netdb.h>
#include <netinet/in.h>
#include "libpq/protocol.h"

Include dependency graph for pqcomm.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	SockAddr

struct	AddrInfo

struct	CancelRequestPacket

Macros
#define	UNIXSOCK_PATH(path, port, sockdir)

#define	UNIXSOCK_PATH_BUFLEN sizeof(((struct sockaddr_un *) NULL)->sun_path)

#define	PG_PROTOCOL_MAJOR(v) ((v) >> 16)

#define	PG_PROTOCOL_MINOR(v) ((v) & 0x0000ffff)

#define	PG_PROTOCOL_FULL(v) (PG_PROTOCOL_MAJOR(v) * 10000 + PG_PROTOCOL_MINOR(v))

#define	PG_PROTOCOL(m, n) (((m) << 16) \| (n))

#define	PG_PROTOCOL_EARLIEST PG_PROTOCOL(3,0)

#define	PG_PROTOCOL_LATEST PG_PROTOCOL(3,2)

#define	PG_PROTOCOL_RESERVED_31 PG_PROTOCOL(3,1)

#define	PG_PROTOCOL_GREASE PG_PROTOCOL(3,9999)

#define	CANCEL_REQUEST_CODE PG_PROTOCOL(1234,5678)

#define	NEGOTIATE_SSL_CODE PG_PROTOCOL(1234,5679)

#define	NEGOTIATE_GSS_CODE PG_PROTOCOL(1234,5680)

#define	MAX_STARTUP_PACKET_LENGTH 10000

#define	PG_ALPN_PROTOCOL "postgresql"

#define	PG_ALPN_PROTOCOL_VECTOR { 10, 'p','o','s','t','g','r','e','s','q','l' }

Typedefs
typedef uint32	ProtocolVersion

typedef uint32	PacketLen

typedef uint32	AuthRequest

typedef struct CancelRequestPacket	CancelRequestPacket

Functions
static bool	is_unixsock_path (const char *path)

Macro Definition Documentation

◆ CANCEL_REQUEST_CODE

#define CANCEL_REQUEST_CODE PG_PROTOCOL(1234,5678)

Definition at line 122 of file pqcomm.h.

◆ MAX_STARTUP_PACKET_LENGTH

#define MAX_STARTUP_PACKET_LENGTH 10000

Definition at line 148 of file pqcomm.h.

◆ NEGOTIATE_GSS_CODE

#define NEGOTIATE_GSS_CODE PG_PROTOCOL(1234,5680)

Definition at line 129 of file pqcomm.h.

◆ NEGOTIATE_SSL_CODE

#define NEGOTIATE_SSL_CODE PG_PROTOCOL(1234,5679)

Definition at line 128 of file pqcomm.h.

◆ PG_ALPN_PROTOCOL

#define PG_ALPN_PROTOCOL "postgresql"

Definition at line 189 of file pqcomm.h.

◆ PG_ALPN_PROTOCOL_VECTOR

#define PG_ALPN_PROTOCOL_VECTOR { 10, 'p','o','s','t','g','r','e','s','q','l' }

Definition at line 190 of file pqcomm.h.

◆ PG_PROTOCOL

#define PG_PROTOCOL	(	m,
		n
	)	(((m) << 16) \| (n))

Definition at line 89 of file pqcomm.h.

◆ PG_PROTOCOL_EARLIEST

#define PG_PROTOCOL_EARLIEST PG_PROTOCOL(3,0)

Definition at line 94 of file pqcomm.h.

◆ PG_PROTOCOL_FULL

#define PG_PROTOCOL_FULL ( v ) (PG_PROTOCOL_MAJOR(v) * 10000 + PG_PROTOCOL_MINOR(v))

Definition at line 88 of file pqcomm.h.

◆ PG_PROTOCOL_GREASE

#define PG_PROTOCOL_GREASE PG_PROTOCOL(3,9999)

Definition at line 115 of file pqcomm.h.

◆ PG_PROTOCOL_LATEST

#define PG_PROTOCOL_LATEST PG_PROTOCOL(3,2)

Definition at line 95 of file pqcomm.h.

◆ PG_PROTOCOL_MAJOR

#define PG_PROTOCOL_MAJOR ( v ) ((v) >> 16)

Definition at line 86 of file pqcomm.h.

◆ PG_PROTOCOL_MINOR

#define PG_PROTOCOL_MINOR ( v ) ((v) & 0x0000ffff)

Definition at line 87 of file pqcomm.h.

◆ PG_PROTOCOL_RESERVED_31

#define PG_PROTOCOL_RESERVED_31 PG_PROTOCOL(3,1)

Definition at line 105 of file pqcomm.h.

◆ UNIXSOCK_PATH

#define UNIXSOCK_PATH	(	path,
		port,
		sockdir
	)

Value:

       (AssertMacro(sockdir), \
		AssertMacro(*(sockdir) != '\0'), \
		snprintf(path, sizeof(path), "%s/.s.PGSQL.%d", \
                 (sockdir), (port)))

Definition at line 43 of file pqcomm.h.

{
    return is_absolute_path(path) || path[0] == '@';
}
 
 
/*
 * 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_FULL(v) (PG_PROTOCOL_MAJOR(v) * 10000 + PG_PROTOCOL_MINOR(v))
#define PG_PROTOCOL(m,n)    (((m) << 16) | (n))
 
/*
 * The earliest and latest frontend/backend protocol version supported.
 */
#define PG_PROTOCOL_EARLIEST    PG_PROTOCOL(3,0)
#define PG_PROTOCOL_LATEST      PG_PROTOCOL(3,2)
 
/*
 * Reserved protocol numbers, which have special semantics:
 */
 
/*
 * 3.1 would have collided with old pgbouncer deployments, and was skipped. We
 * neither emit it nor accept it on the wire.
 */
#define PG_PROTOCOL_RESERVED_31     PG_PROTOCOL(3,1)
 
/*
 * PG_PROTOCOL_GREASE is an intentionally unsupported protocol version used
 * for "greasing" (the practice of sending valid, but extraneous or otherwise
 * unusual, messages to keep peer implementations honest). This helps ensure
 * that servers properly implement protocol version negotiation. Version 3.9999
 * was chosen since it is safely within the valid range, it is representable
 * via PQfullProtocolVersion, and it is unlikely to ever be needed in practice.
 */
#define PG_PROTOCOL_GREASE      PG_PROTOCOL(3,9999)
 
/*
 * A client can 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.
 */
#define CANCEL_REQUEST_CODE     PG_PROTOCOL(1234,5678)
 
/*
 * 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)
 
 
typedef uint32 ProtocolVersion; /* FE/BE protocol version number */
 
 
/*
 * Packet lengths are 4 bytes in network byte order.
 *
 * The initial length is omitted from the packet layouts appearing below.
 */
typedef uint32 PacketLen;
 
/*
 * 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
 
 
typedef uint32 AuthRequest;     /* an AUTH_REQ_* code */
 
 
/*
 * The packet used with a CANCEL_REQUEST_CODE.
 *
 * Before PostgreSQL v18 and the protocol version bump from 3.0 to 3.2, the
 * cancel key was always 4 bytes.  With protocol version 3.2, it's variable
 * length.
 */
typedef struct CancelRequestPacket
{
    /* Note that each field is stored in network byte order! */
    ProtocolVersion cancelRequestCode;  /* code to identify a cancel request */
    uint32      backendPID;     /* PID of client's backend */
    uint8       cancelAuthCode[FLEXIBLE_ARRAY_MEMBER];  /* secret key to
                                                         * authorize cancel */
} CancelRequestPacket;
 
 
/*
 * Application-Layer Protocol Negotiation is required for direct connections
 * to avoid protocol confusion attacks (e.g https://alpaca-attack.com/).
 *
 * ALPN is specified in RFC 7301
 *
 * This string should be registered at:
 * https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml#alpn-protocol-ids
 *
 * OpenSSL uses this wire-format for the list of alpn protocols even in the
 * API. Both server and client take the same format parameter but the client
 * actually sends it to the server as-is and the server it specifies the
 * preference order to use to choose the one selected to send back.
 *
 * c.f. https://www.openssl.org/docs/manmaster/man3/SSL_CTX_set_alpn_select_cb.html
 *
 * The #define can be used to initialize a char[] vector to use directly in the API
 */
#define PG_ALPN_PROTOCOL "postgresql"
#define PG_ALPN_PROTOCOL_VECTOR { 10, 'p','o','s','t','g','r','e','s','q','l' }
 
#endif                          /* PQCOMM_H */

◆ UNIXSOCK_PATH_BUFLEN

#define UNIXSOCK_PATH_BUFLEN sizeof(((struct sockaddr_un *) NULL)->sun_path)

Definition at line 59 of file pqcomm.h.

Typedef Documentation

◆ AuthRequest

typedef uint32 AuthRequest

Definition at line 151 of file pqcomm.h.

◆ CancelRequestPacket

typedef struct CancelRequestPacket CancelRequestPacket

◆ PacketLen

typedef uint32 PacketLen

Definition at line 140 of file pqcomm.h.

◆ ProtocolVersion

typedef uint32 ProtocolVersion

Definition at line 132 of file pqcomm.h.

Function Documentation

◆ is_unixsock_path()

static bool is_unixsock_path ( const char * path )

inlinestatic

Definition at line 66 of file pqcomm.h.

{
    return is_absolute_path(path) || path[0] == '@';
}

References is_absolute_path.

Referenced by check_pghost_envvar(), do_connect(), exec_command_conninfo(), get_prompt(), passwordFromFile(), and pqConnectOptions2().

Data Structures

Macros

Typedefs

Functions