#include "postgres.h"
#include <signal.h>
#include <fcntl.h>
#include <grp.h>
#include <unistd.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "libpq/ip.h"
#include "libpq/libpq.h"
#include "miscadmin.h"
#include "storage/ipc.h"
#include "utils/guc.h"
#include "utils/memutils.h"

Include dependency graph for pqcomm.c:

Defines
#define	PQ_SEND_BUFFER_SIZE 8192
#define	PQ_RECV_BUFFER_SIZE 8192
Functions
static void	pq_close (int code, Datum arg)
static int	internal_putbytes (const char *s, size_t len)
static int	internal_flush (void)
static void	pq_set_nonblocking (bool nonblocking)
void	pq_init (void)
void	pq_comm_reset (void)
int	StreamServerPort (int family, char hostName, unsigned short portNumber, char unixSocketDir, pgsocket ListenSocket[], int MaxListen)
int	StreamConnection (pgsocket server_fd, Port *port)
void	StreamClose (pgsocket sock)
void	TouchSocketFiles (void)
static int	pq_recvbuf (void)
int	pq_getbyte (void)
int	pq_peekbyte (void)
int	pq_getbyte_if_available (unsigned char *c)
int	pq_getbytes (char *s, size_t len)
static int	pq_discardbytes (size_t len)
int	pq_getstring (StringInfo s)
int	pq_getmessage (StringInfo s, int maxlen)
int	pq_putbytes (const char *s, size_t len)
int	pq_flush (void)
int	pq_flush_if_writable (void)
bool	pq_is_send_pending (void)
int	pq_putmessage (char msgtype, const char *s, size_t len)
void	pq_putmessage_noblock (char msgtype, const char *s, size_t len)
void	pq_startcopyout (void)
void	pq_endcopyout (bool errorAbort)
int	pq_getkeepalivesidle (Port *port)
int	pq_setkeepalivesidle (int idle, Port *port)
int	pq_getkeepalivesinterval (Port *port)
int	pq_setkeepalivesinterval (int interval, Port *port)
int	pq_getkeepalivescount (Port *port)
int	pq_setkeepalivescount (int count, Port *port)
Variables
int	Unix_socket_permissions
char *	Unix_socket_group
static List *	sock_paths = NIL
static char *	PqSendBuffer
static int	PqSendBufferSize
static int	PqSendPointer
static int	PqSendStart
static char	PqRecvBuffer [PQ_RECV_BUFFER_SIZE]
static int	PqRecvPointer
static int	PqRecvLength
static bool	PqCommBusy
static bool	DoingCopyOut

Define Documentation

#define PQ_RECV_BUFFER_SIZE 8192

Definition at line 118 of file pqcomm.c.

Referenced by pq_recvbuf().

#define PQ_SEND_BUFFER_SIZE 8192

Definition at line 117 of file pqcomm.c.

Referenced by StreamConnection().

Function Documentation

static int internal_flush ( void ) [static]

Definition at line 1241 of file pqcomm.c.

References ClientConnectionLost, COMMERROR, EAGAIN, EINTR, ereport, errcode_for_socket_access(), errmsg(), EWOULDBLOCK, InterruptPending, MyProcPort, PqSendBuffer, PqSendPointer, PqSendStart, and secure_write().

Referenced by internal_putbytes(), pq_flush(), and pq_flush_if_writable().

{
    static int  last_reported_send_errno = 0;

    char       *bufptr = PqSendBuffer + PqSendStart;
    char       *bufend = PqSendBuffer + PqSendPointer;

    while (bufptr < bufend)
    {
        int         r;

        r = secure_write(MyProcPort, bufptr, bufend - bufptr);

        if (r <= 0)
        {
            if (errno == EINTR)
                continue;       /* Ok if we were interrupted */

            /*
             * Ok if no data writable without blocking, and the socket is in
             * non-blocking mode.
             */
            if (errno == EAGAIN ||
                errno == EWOULDBLOCK)
            {
                return 0;
            }

            /*
             * Careful: an ereport() that tries to write to the client would
             * cause recursion to here, leading to stack overflow and core
             * dump!  This message must go *only* to the postmaster log.
             *
             * If a client disconnects while we're in the midst of output, we
             * might write quite a bit of data before we get to a safe query
             * abort point.  So, suppress duplicate log messages.
             */
            if (errno != last_reported_send_errno)
            {
                last_reported_send_errno = errno;
                ereport(COMMERROR,
                        (errcode_for_socket_access(),
                         errmsg("could not send data to client: %m")));
            }

            /*
             * We drop the buffered data anyway so that processing can
             * continue, even though we'll probably quit soon. We also set a
             * flag that'll cause the next CHECK_FOR_INTERRUPTS to terminate
             * the connection.
             */
            PqSendStart = PqSendPointer = 0;
            ClientConnectionLost = 1;
            InterruptPending = 1;
            return EOF;
        }

        last_reported_send_errno = 0;   /* reset after any successful send */
        bufptr += r;
        PqSendStart += r;
    }

    PqSendStart = PqSendPointer = 0;
    return 0;
}

static int internal_putbytes	(	const char *	s,
		size_t	len
	)			`[static]`

Definition at line 1188 of file pqcomm.c.

References internal_flush(), pq_set_nonblocking(), PqSendBuffer, PqSendBufferSize, and PqSendPointer.

Referenced by pq_putbytes(), and pq_putmessage().

{
    size_t      amount;

    while (len > 0)
    {
        /* If buffer is full, then flush it out */
        if (PqSendPointer >= PqSendBufferSize)
        {
            pq_set_nonblocking(false);
            if (internal_flush())
                return EOF;
        }
        amount = PqSendBufferSize - PqSendPointer;
        if (amount > len)
            amount = len;
        memcpy(PqSendBuffer + PqSendPointer, s, amount);
        PqSendPointer += amount;
        s += amount;
        len -= amount;
    }
    return 0;
}

static void pq_close	(	int	code,
		Datum	arg
	)			`[static]`

Definition at line 188 of file pqcomm.c.

References free, Port::gss, MyProcPort, NULL, secure_close(), and Port::sock.

Referenced by pq_init().

{
    if (MyProcPort != NULL)
    {
#if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
#ifdef ENABLE_GSS
        OM_uint32   min_s;

        /* Shutdown GSSAPI layer */
        if (MyProcPort->gss->ctx != GSS_C_NO_CONTEXT)
            gss_delete_sec_context(&min_s, &MyProcPort->gss->ctx, NULL);

        if (MyProcPort->gss->cred != GSS_C_NO_CREDENTIAL)
            gss_release_cred(&min_s, &MyProcPort->gss->cred);
#endif   /* ENABLE_GSS */
        /* GSS and SSPI share the port->gss struct */

        free(MyProcPort->gss);
#endif   /* ENABLE_GSS || ENABLE_SSPI */

        /* Cleanly shut down SSL layer */
        secure_close(MyProcPort);

        /*
         * Formerly we did an explicit close() here, but it seems better to
         * leave the socket open until the process dies.  This allows clients
         * to perform a "synchronous close" if they care --- wait till the
         * transport layer reports connection closure, and you can be sure the
         * backend has exited.
         *
         * We do set sock to PGINVALID_SOCKET to prevent any further I/O,
         * though.
         */
        MyProcPort->sock = PGINVALID_SOCKET;
    }
}

void pq_comm_reset ( void )

Definition at line 172 of file pqcomm.c.

References pq_endcopyout(), and PqCommBusy.

Referenced by PostgresMain().

{
    /* Do not throw away pending data, but do reset the busy flag */
    PqCommBusy = false;
    /* We can abort any old-style COPY OUT, too */
    pq_endcopyout(true);
}

static int pq_discardbytes ( size_t len ) [static]

Definition at line 1011 of file pqcomm.c.

References pq_recvbuf(), PqRecvLength, and PqRecvPointer.

Referenced by pq_getmessage().

{
    size_t      amount;

    while (len > 0)
    {
        while (PqRecvPointer >= PqRecvLength)
        {
            if (pq_recvbuf())   /* If nothing in buffer, then recv some */
                return EOF;     /* Failed to recv data */
        }
        amount = PqRecvLength - PqRecvPointer;
        if (amount > len)
            amount = len;
        PqRecvPointer += amount;
        len -= amount;
    }
    return 0;
}

void pq_endcopyout ( bool errorAbort )

Definition at line 1455 of file pqcomm.c.

References DoingCopyOut, and pq_putbytes().

Referenced by DoCopyTo(), errfinish(), pq_comm_reset(), and SendCopyEnd().

{
    if (!DoingCopyOut)
        return;
    if (errorAbort)
        pq_putbytes("\n\n\\.\n", 5);
    /* in non-error case, copy.c will have emitted the terminator line */
    DoingCopyOut = false;
}

int pq_flush ( void )

Definition at line 1219 of file pqcomm.c.

References internal_flush(), pq_set_nonblocking(), and PqCommBusy.

Referenced by PostgresMain(), ProcessIncomingNotify(), ReadyForQuery(), ReceiveCopyBegin(), send_message_to_frontend(), sendAuthRequest(), StartReplication(), and WalSndLoop().

{
    int         res;

    /* No-op if reentrant call */
    if (PqCommBusy)
        return 0;
    PqCommBusy = true;
    pq_set_nonblocking(false);
    res = internal_flush();
    PqCommBusy = false;
    return res;
}

int pq_flush_if_writable ( void )

Definition at line 1314 of file pqcomm.c.

References internal_flush(), pq_set_nonblocking(), PqCommBusy, PqSendPointer, and PqSendStart.

Referenced by WalSndLoop().

{
    int         res;

    /* Quick exit if nothing to do */
    if (PqSendPointer == PqSendStart)
        return 0;

    /* No-op if reentrant call */
    if (PqCommBusy)
        return 0;

    /* Temporarily put the socket into non-blocking mode */
    pq_set_nonblocking(true);

    PqCommBusy = true;
    res = internal_flush();
    PqCommBusy = false;
    return res;
}

int pq_getbyte ( void )

Definition at line 891 of file pqcomm.c.

References pq_recvbuf(), PqRecvBuffer, PqRecvLength, and PqRecvPointer.

Referenced by CopyGetData(), recv_password_packet(), and SocketBackend().

{
    while (PqRecvPointer >= PqRecvLength)
    {
        if (pq_recvbuf())       /* If nothing in buffer, then recv some */
            return EOF;         /* Failed to recv data */
    }
    return (unsigned char) PqRecvBuffer[PqRecvPointer++];
}

int pq_getbyte_if_available ( unsigned char * c )

Definition at line 927 of file pqcomm.c.

References COMMERROR, EAGAIN, EINTR, ereport, errcode_for_socket_access(), errmsg(), EWOULDBLOCK, MyProcPort, pq_set_nonblocking(), PqRecvBuffer, PqRecvLength, PqRecvPointer, and secure_read().

Referenced by ProcessRepliesIfAny().

{
    int         r;

    if (PqRecvPointer < PqRecvLength)
    {
        *c = PqRecvBuffer[PqRecvPointer++];
        return 1;
    }

    /* Put the socket into non-blocking mode */
    pq_set_nonblocking(true);

    r = secure_read(MyProcPort, c, 1);
    if (r < 0)
    {
        /*
         * Ok if no data available without blocking or interrupted (though
         * EINTR really shouldn't happen with a non-blocking socket). Report
         * other errors.
         */
        if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
            r = 0;
        else
        {
            /*
             * Careful: an ereport() that tries to write to the client would
             * cause recursion to here, leading to stack overflow and core
             * dump!  This message must go *only* to the postmaster log.
             */
            ereport(COMMERROR,
                    (errcode_for_socket_access(),
                     errmsg("could not receive data from client: %m")));
            r = EOF;
        }
    }
    else if (r == 0)
    {
        /* EOF detected */
        r = EOF;
    }

    return r;
}

int pq_getbytes	(	char *	s,
		size_t	len
	)

Definition at line 979 of file pqcomm.c.

References pq_recvbuf(), PqRecvBuffer, PqRecvLength, and PqRecvPointer.

Referenced by CopyGetData(), GetOldFunctionMessage(), pq_getmessage(), and ProcessStartupPacket().

{
    size_t      amount;

    while (len > 0)
    {
        while (PqRecvPointer >= PqRecvLength)
        {
            if (pq_recvbuf())   /* If nothing in buffer, then recv some */
                return EOF;     /* Failed to recv data */
        }
        amount = PqRecvLength - PqRecvPointer;
        if (amount > len)
            amount = len;
        memcpy(s, PqRecvBuffer + PqRecvPointer, amount);
        PqRecvPointer += amount;
        s += amount;
        len -= amount;
    }
    return 0;
}

int pq_getkeepalivescount ( Port * port )

Definition at line 1696 of file pqcomm.c.

References SockAddr::addr, Port::default_keepalives_count, elog, IS_AF_UNIX, Port::keepalives_count, Port::laddr, LOG, NULL, and Port::sock.

Referenced by pq_setkeepalivescount(), and show_tcp_keepalives_count().

{
#ifdef TCP_KEEPCNT
    if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
        return 0;

    if (port->keepalives_count != 0)
        return port->keepalives_count;

    if (port->default_keepalives_count == 0)
    {
        ACCEPT_TYPE_ARG3 size = sizeof(port->default_keepalives_count);

        if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
                       (char *) &port->default_keepalives_count,
                       &size) < 0)
        {
            elog(LOG, "getsockopt(TCP_KEEPCNT) failed: %m");
            port->default_keepalives_count = -1;        /* don't know */
        }
    }

    return port->default_keepalives_count;
#else
    return 0;
#endif
}

int pq_getkeepalivesidle ( Port * port )

Definition at line 1516 of file pqcomm.c.

References SockAddr::addr, Port::default_keepalives_idle, elog, IS_AF_UNIX, Port::keepalives_idle, Port::laddr, LOG, NULL, and Port::sock.

Referenced by pq_setkeepalivesidle(), and show_tcp_keepalives_idle().

{
#if defined(TCP_KEEPIDLE) || defined(TCP_KEEPALIVE) || defined(WIN32)
    if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
        return 0;

    if (port->keepalives_idle != 0)
        return port->keepalives_idle;

    if (port->default_keepalives_idle == 0)
    {
#ifndef WIN32
        ACCEPT_TYPE_ARG3 size = sizeof(port->default_keepalives_idle);

#ifdef TCP_KEEPIDLE
        if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPIDLE,
                       (char *) &port->default_keepalives_idle,
                       &size) < 0)
        {
            elog(LOG, "getsockopt(TCP_KEEPIDLE) failed: %m");
            port->default_keepalives_idle = -1; /* don't know */
        }
#else
        if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPALIVE,
                       (char *) &port->default_keepalives_idle,
                       &size) < 0)
        {
            elog(LOG, "getsockopt(TCP_KEEPALIVE) failed: %m");
            port->default_keepalives_idle = -1; /* don't know */
        }
#endif   /* TCP_KEEPIDLE */
#else                           /* WIN32 */
        /* We can't get the defaults on Windows, so return "don't know" */
        port->default_keepalives_idle = -1;
#endif   /* WIN32 */
    }

    return port->default_keepalives_idle;
#else
    return 0;
#endif
}

int pq_getkeepalivesinterval ( Port * port )

Definition at line 1615 of file pqcomm.c.

References SockAddr::addr, Port::default_keepalives_interval, elog, IS_AF_UNIX, Port::keepalives_interval, Port::laddr, LOG, NULL, and Port::sock.

Referenced by pq_setkeepalivesinterval(), and show_tcp_keepalives_interval().

{
#if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
    if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
        return 0;

    if (port->keepalives_interval != 0)
        return port->keepalives_interval;

    if (port->default_keepalives_interval == 0)
    {
#ifndef WIN32
        ACCEPT_TYPE_ARG3 size = sizeof(port->default_keepalives_interval);

        if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
                       (char *) &port->default_keepalives_interval,
                       &size) < 0)
        {
            elog(LOG, "getsockopt(TCP_KEEPINTVL) failed: %m");
            port->default_keepalives_interval = -1;     /* don't know */
        }
#else
        /* We can't get the defaults on Windows, so return "don't know" */
        port->default_keepalives_interval = -1;
#endif   /* WIN32 */
    }

    return port->default_keepalives_interval;
#else
    return 0;
#endif
}

int pq_getmessage	(	StringInfo	s,
		int	maxlen
	)

Definition at line 1099 of file pqcomm.c.

References COMMERROR, StringInfoData::data, enlargeStringInfo(), ereport, errcode(), errmsg(), StringInfoData::len, PG_CATCH, PG_END_TRY, PG_RE_THROW, PG_TRY, pq_discardbytes(), pq_getbytes(), and resetStringInfo().

Referenced by CopyGetData(), ProcessRepliesIfAny(), ProcessStandbyMessage(), recv_password_packet(), and SocketBackend().

{
    int32       len;

    resetStringInfo(s);

    /* Read message length word */
    if (pq_getbytes((char *) &len, 4) == EOF)
    {
        ereport(COMMERROR,
                (errcode(ERRCODE_PROTOCOL_VIOLATION),
                 errmsg("unexpected EOF within message length word")));
        return EOF;
    }

    len = ntohl(len);

    if (len < 4 ||
        (maxlen > 0 && len > maxlen))
    {
        ereport(COMMERROR,
                (errcode(ERRCODE_PROTOCOL_VIOLATION),
                 errmsg("invalid message length")));
        return EOF;
    }

    len -= 4;                   /* discount length itself */

    if (len > 0)
    {
        /*
         * Allocate space for message.  If we run out of room (ridiculously
         * large message), we will elog(ERROR), but we want to discard the
         * message body so as not to lose communication sync.
         */
        PG_TRY();
        {
            enlargeStringInfo(s, len);
        }
        PG_CATCH();
        {
            if (pq_discardbytes(len) == EOF)
                ereport(COMMERROR,
                        (errcode(ERRCODE_PROTOCOL_VIOLATION),
                         errmsg("incomplete message from client")));
            PG_RE_THROW();
        }
        PG_END_TRY();

        /* And grab the message */
        if (pq_getbytes(s->data, len) == EOF)
        {
            ereport(COMMERROR,
                    (errcode(ERRCODE_PROTOCOL_VIOLATION),
                     errmsg("incomplete message from client")));
            return EOF;
        }
        s->len = len;
        /* Place a trailing null per StringInfo convention */
        s->data[len] = '\0';
    }

    return 0;
}

int pq_getstring ( StringInfo s )

Definition at line 1047 of file pqcomm.c.

References appendBinaryStringInfo(), i, pq_recvbuf(), PqRecvBuffer, PqRecvLength, PqRecvPointer, and resetStringInfo().

Referenced by GetOldFunctionMessage(), and SocketBackend().

{
    int         i;

    resetStringInfo(s);

    /* Read until we get the terminating '\0' */
    for (;;)
    {
        while (PqRecvPointer >= PqRecvLength)
        {
            if (pq_recvbuf())   /* If nothing in buffer, then recv some */
                return EOF;     /* Failed to recv data */
        }

        for (i = PqRecvPointer; i < PqRecvLength; i++)
        {
            if (PqRecvBuffer[i] == '\0')
            {
                /* include the '\0' in the copy */
                appendBinaryStringInfo(s, PqRecvBuffer + PqRecvPointer,
                                       i - PqRecvPointer + 1);
                PqRecvPointer = i + 1;  /* advance past \0 */
                return 0;
            }
        }

        /* If we're here we haven't got the \0 in the buffer yet. */
        appendBinaryStringInfo(s, PqRecvBuffer + PqRecvPointer,
                               PqRecvLength - PqRecvPointer);
        PqRecvPointer = PqRecvLength;
    }
}

void pq_init ( void )

Definition at line 153 of file pqcomm.c.

References DoingCopyOut, MemoryContextAlloc(), on_proc_exit(), pq_close(), PqCommBusy, PqRecvLength, PqRecvPointer, PqSendBuffer, PqSendBufferSize, PqSendPointer, PqSendStart, and TopMemoryContext.

Referenced by BackendInitialize().

{
    PqSendBufferSize = PQ_SEND_BUFFER_SIZE;
    PqSendBuffer = MemoryContextAlloc(TopMemoryContext, PqSendBufferSize);
    PqSendPointer = PqSendStart = PqRecvPointer = PqRecvLength = 0;
    PqCommBusy = false;
    DoingCopyOut = false;
    on_proc_exit(pq_close, 0);
}

bool pq_is_send_pending ( void )

Definition at line 1340 of file pqcomm.c.

References PqSendPointer, and PqSendStart.

Referenced by WalSndLoop().

{
    return (PqSendStart < PqSendPointer);
}

int pq_peekbyte ( void )

Definition at line 908 of file pqcomm.c.

References pq_recvbuf(), PqRecvBuffer, PqRecvLength, and PqRecvPointer.

Referenced by recv_password_packet().

{
    while (PqRecvPointer >= PqRecvLength)
    {
        if (pq_recvbuf())       /* If nothing in buffer, then recv some */
            return EOF;         /* Failed to recv data */
    }
    return (unsigned char) PqRecvBuffer[PqRecvPointer];
}

int pq_putbytes	(	const char *	s,
		size_t	len
	)

Definition at line 1172 of file pqcomm.c.

References Assert, DoingCopyOut, internal_putbytes(), and PqCommBusy.

Referenced by CopySendEndOfRow(), and pq_endcopyout().

{
    int         res;

    /* Should only be called by old-style COPY OUT */
    Assert(DoingCopyOut);
    /* No-op if reentrant call */
    if (PqCommBusy)
        return 0;
    PqCommBusy = true;
    res = internal_putbytes(s, len);
    PqCommBusy = false;
    return res;
}

int pq_putmessage	(	char	msgtype,
		const char *	s,
		size_t	len
	)

Definition at line 1379 of file pqcomm.c.

References DoingCopyOut, FrontendProtocol, internal_putbytes(), PG_PROTOCOL_MAJOR, and PqCommBusy.

Referenced by _tarWriteHeader(), CopySendEndOfRow(), EndCommand(), NullCommand(), perform_base_backup(), pq_endmessage(), pq_putemptymessage(), pq_putmessage_noblock(), pq_puttextmessage(), sendFile(), and sendFileWithContent().

{
    if (DoingCopyOut || PqCommBusy)
        return 0;
    PqCommBusy = true;
    if (msgtype)
        if (internal_putbytes(&msgtype, 1))
            goto fail;
    if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
    {
        uint32      n32;

        n32 = htonl((uint32) (len + 4));
        if (internal_putbytes((char *) &n32, 4))
            goto fail;
    }
    if (internal_putbytes(s, len))
        goto fail;
    PqCommBusy = false;
    return 0;

fail:
    PqCommBusy = false;
    return EOF;
}

void pq_putmessage_noblock	(	char	msgtype,
		const char *	s,
		size_t	len
	)

Definition at line 1412 of file pqcomm.c.

References Assert, pq_putmessage(), PqSendBuffer, PqSendBufferSize, PqSendPointer, and repalloc().

Referenced by ProcessRepliesIfAny(), WalSndKeepalive(), and XLogSend().

{
    int res     PG_USED_FOR_ASSERTS_ONLY;
    int         required;

    /*
     * Ensure we have enough space in the output buffer for the message header
     * as well as the message itself.
     */
    required = PqSendPointer + 1 + 4 + len;
    if (required > PqSendBufferSize)
    {
        PqSendBuffer = repalloc(PqSendBuffer, required);
        PqSendBufferSize = required;
    }
    res = pq_putmessage(msgtype, s, len);
    Assert(res == 0);           /* should not fail when the message fits in
                                 * buffer */
}

static int pq_recvbuf ( void ) [static]

Definition at line 830 of file pqcomm.c.

References COMMERROR, EINTR, ereport, errcode_for_socket_access(), errmsg(), memmove, MyProcPort, PQ_RECV_BUFFER_SIZE, pq_set_nonblocking(), PqRecvBuffer, PqRecvLength, PqRecvPointer, and secure_read().

Referenced by pq_discardbytes(), pq_getbyte(), pq_getbytes(), pq_getstring(), and pq_peekbyte().

{
    if (PqRecvPointer > 0)
    {
        if (PqRecvLength > PqRecvPointer)
        {
            /* still some unread data, left-justify it in the buffer */
            memmove(PqRecvBuffer, PqRecvBuffer + PqRecvPointer,
                    PqRecvLength - PqRecvPointer);
            PqRecvLength -= PqRecvPointer;
            PqRecvPointer = 0;
        }
        else
            PqRecvLength = PqRecvPointer = 0;
    }

    /* Ensure that we're in blocking mode */
    pq_set_nonblocking(false);

    /* Can fill buffer from PqRecvLength and upwards */
    for (;;)
    {
        int         r;

        r = secure_read(MyProcPort, PqRecvBuffer + PqRecvLength,
                        PQ_RECV_BUFFER_SIZE - PqRecvLength);

        if (r < 0)
        {
            if (errno == EINTR)
                continue;       /* Ok if interrupted */

            /*
             * Careful: an ereport() that tries to write to the client would
             * cause recursion to here, leading to stack overflow and core
             * dump!  This message must go *only* to the postmaster log.
             */
            ereport(COMMERROR,
                    (errcode_for_socket_access(),
                     errmsg("could not receive data from client: %m")));
            return EOF;
        }
        if (r == 0)
        {
            /*
             * EOF detected.  We used to write a log message here, but it's
             * better to expect the ultimate caller to do that.
             */
            return EOF;
        }
        /* r contains number of bytes read, so just incr length */
        PqRecvLength += r;
        return 0;
    }
}

static void pq_set_nonblocking ( bool nonblocking ) [static]

Definition at line 793 of file pqcomm.c.

References COMMERROR, ereport, errmsg(), MyProcPort, Port::noblock, pg_set_block(), pg_set_noblock(), pgwin32_noblock, and Port::sock.

Referenced by internal_putbytes(), pq_flush(), pq_flush_if_writable(), pq_getbyte_if_available(), and pq_recvbuf().

{
    if (MyProcPort->noblock == nonblocking)
        return;

#ifdef WIN32
    pgwin32_noblock = nonblocking ? 1 : 0;
#else

    /*
     * Use COMMERROR on failure, because ERROR would try to send the error to
     * the client, which might require changing the mode again, leading to
     * infinite recursion.
     */
    if (nonblocking)
    {
        if (!pg_set_noblock(MyProcPort->sock))
            ereport(COMMERROR,
                  (errmsg("could not set socket to nonblocking mode: %m")));
    }
    else
    {
        if (!pg_set_block(MyProcPort->sock))
            ereport(COMMERROR,
                    (errmsg("could not set socket to blocking mode: %m")));
    }
#endif
    MyProcPort->noblock = nonblocking;
}

int pq_setkeepalivescount	(	int	count,
		Port *	port
	)

Definition at line 1725 of file pqcomm.c.

References SockAddr::addr, Port::default_keepalives_count, elog, IS_AF_UNIX, Port::keepalives_count, Port::laddr, LOG, NULL, pq_getkeepalivescount(), and Port::sock.

Referenced by assign_tcp_keepalives_count(), and StreamConnection().

{
    if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
        return STATUS_OK;

#ifdef TCP_KEEPCNT
    if (count == port->keepalives_count)
        return STATUS_OK;

    if (port->default_keepalives_count <= 0)
    {
        if (pq_getkeepalivescount(port) < 0)
        {
            if (count == 0)
                return STATUS_OK;       /* default is set but unknown */
            else
                return STATUS_ERROR;
        }
    }

    if (count == 0)
        count = port->default_keepalives_count;

    if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
                   (char *) &count, sizeof(count)) < 0)
    {
        elog(LOG, "setsockopt(TCP_KEEPCNT) failed: %m");
        return STATUS_ERROR;
    }

    port->keepalives_count = count;
#else
    if (count != 0)
    {
        elog(LOG, "setsockopt(TCP_KEEPCNT) not supported");
        return STATUS_ERROR;
    }
#endif

    return STATUS_OK;
}

int pq_setkeepalivesidle	(	int	idle,
		Port *	port
	)

Definition at line 1560 of file pqcomm.c.

References SockAddr::addr, Port::default_keepalives_idle, elog, IS_AF_UNIX, Port::keepalives_idle, Port::keepalives_interval, Port::laddr, LOG, NULL, pq_getkeepalivesidle(), and Port::sock.

Referenced by assign_tcp_keepalives_idle(), and StreamConnection().

{
    if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
        return STATUS_OK;

#if defined(TCP_KEEPIDLE) || defined(TCP_KEEPALIVE) || defined(SIO_KEEPALIVE_VALS)
    if (idle == port->keepalives_idle)
        return STATUS_OK;

#ifndef WIN32
    if (port->default_keepalives_idle <= 0)
    {
        if (pq_getkeepalivesidle(port) < 0)
        {
            if (idle == 0)
                return STATUS_OK;       /* default is set but unknown */
            else
                return STATUS_ERROR;
        }
    }

    if (idle == 0)
        idle = port->default_keepalives_idle;

#ifdef TCP_KEEPIDLE
    if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPIDLE,
                   (char *) &idle, sizeof(idle)) < 0)
    {
        elog(LOG, "setsockopt(TCP_KEEPIDLE) failed: %m");
        return STATUS_ERROR;
    }
#else
    if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPALIVE,
                   (char *) &idle, sizeof(idle)) < 0)
    {
        elog(LOG, "setsockopt(TCP_KEEPALIVE) failed: %m");
        return STATUS_ERROR;
    }
#endif

    port->keepalives_idle = idle;
#else                           /* WIN32 */
    return pq_setkeepaliveswin32(port, idle, port->keepalives_interval);
#endif
#else                           /* TCP_KEEPIDLE || SIO_KEEPALIVE_VALS */
    if (idle != 0)
    {
        elog(LOG, "setting the keepalive idle time is not supported");
        return STATUS_ERROR;
    }
#endif
    return STATUS_OK;
}

int pq_setkeepalivesinterval	(	int	interval,
		Port *	port
	)

Definition at line 1649 of file pqcomm.c.

References SockAddr::addr, Port::default_keepalives_interval, elog, IS_AF_UNIX, Port::keepalives_idle, Port::keepalives_interval, Port::laddr, LOG, NULL, pq_getkeepalivesinterval(), and Port::sock.

Referenced by assign_tcp_keepalives_interval(), and StreamConnection().

{
    if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
        return STATUS_OK;

#if defined(TCP_KEEPINTVL) || defined (SIO_KEEPALIVE_VALS)
    if (interval == port->keepalives_interval)
        return STATUS_OK;

#ifndef WIN32
    if (port->default_keepalives_interval <= 0)
    {
        if (pq_getkeepalivesinterval(port) < 0)
        {
            if (interval == 0)
                return STATUS_OK;       /* default is set but unknown */
            else
                return STATUS_ERROR;
        }
    }

    if (interval == 0)
        interval = port->default_keepalives_interval;

    if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
                   (char *) &interval, sizeof(interval)) < 0)
    {
        elog(LOG, "setsockopt(TCP_KEEPINTVL) failed: %m");
        return STATUS_ERROR;
    }

    port->keepalives_interval = interval;
#else                           /* WIN32 */
    return pq_setkeepaliveswin32(port, port->keepalives_idle, interval);
#endif
#else
    if (interval != 0)
    {
        elog(LOG, "setsockopt(TCP_KEEPINTVL) not supported");
        return STATUS_ERROR;
    }
#endif

    return STATUS_OK;
}

void pq_startcopyout ( void )

Definition at line 1439 of file pqcomm.c.

References DoingCopyOut.

Referenced by SendCopyBegin().

{
    DoingCopyOut = true;
}

void StreamClose ( pgsocket sock )

Definition at line 735 of file pqcomm.c.

References closesocket.

Referenced by ClosePostmasterPorts(), ConnCreate(), and ServerLoop().

{
    closesocket(sock);
}

int StreamConnection	(	pgsocket	server_fd,
		Port *	port
	)

Definition at line 629 of file pqcomm.c.

References accept, SockAddr::addr, elog, ereport, errcode_for_socket_access(), errmsg(), IS_AF_UNIX, Port::laddr, LOG, pg_usleep(), PQ_SEND_BUFFER_SIZE, pq_setkeepalivescount(), pq_setkeepalivesidle(), pq_setkeepalivesinterval(), Port::raddr, SockAddr::salen, Port::sock, tcp_keepalives_count, tcp_keepalives_idle, and tcp_keepalives_interval.

Referenced by ConnCreate().

{
    /* accept connection and fill in the client (remote) address */
    port->raddr.salen = sizeof(port->raddr.addr);
    if ((port->sock = accept(server_fd,
                             (struct sockaddr *) & port->raddr.addr,
                             &port->raddr.salen)) < 0)
    {
        ereport(LOG,
                (errcode_for_socket_access(),
                 errmsg("could not accept new connection: %m")));

        /*
         * If accept() fails then postmaster.c will still see the server
         * socket as read-ready, and will immediately try again.  To avoid
         * uselessly sucking lots of CPU, delay a bit before trying again.
         * (The most likely reason for failure is being out of kernel file
         * table slots; we can do little except hope some will get freed up.)
         */
        pg_usleep(100000L);     /* wait 0.1 sec */
        return STATUS_ERROR;
    }

#ifdef SCO_ACCEPT_BUG

    /*
     * UnixWare 7+ and OpenServer 5.0.4 are known to have this bug, but it
     * shouldn't hurt to catch it for all versions of those platforms.
     */
    if (port->raddr.addr.ss_family == 0)
        port->raddr.addr.ss_family = AF_UNIX;
#endif

    /* fill in the server (local) address */
    port->laddr.salen = sizeof(port->laddr.addr);
    if (getsockname(port->sock,
                    (struct sockaddr *) & port->laddr.addr,
                    &port->laddr.salen) < 0)
    {
        elog(LOG, "getsockname() failed: %m");
        return STATUS_ERROR;
    }

    /* select NODELAY and KEEPALIVE options if it's a TCP connection */
    if (!IS_AF_UNIX(port->laddr.addr.ss_family))
    {
        int         on;

#ifdef  TCP_NODELAY
        on = 1;
        if (setsockopt(port->sock, IPPROTO_TCP, TCP_NODELAY,
                       (char *) &on, sizeof(on)) < 0)
        {
            elog(LOG, "setsockopt(TCP_NODELAY) failed: %m");
            return STATUS_ERROR;
        }
#endif
        on = 1;
        if (setsockopt(port->sock, SOL_SOCKET, SO_KEEPALIVE,
                       (char *) &on, sizeof(on)) < 0)
        {
            elog(LOG, "setsockopt(SO_KEEPALIVE) failed: %m");
            return STATUS_ERROR;
        }

#ifdef WIN32

        /*
         * This is a Win32 socket optimization.  The ideal size is 32k.
         * http://support.microsoft.com/kb/823764/EN-US/
         */
        on = PQ_SEND_BUFFER_SIZE * 4;
        if (setsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &on,
                       sizeof(on)) < 0)
        {
            elog(LOG, "setsockopt(SO_SNDBUF) failed: %m");
            return STATUS_ERROR;
        }
#endif

        /*
         * Also apply the current keepalive parameters.  If we fail to set a
         * parameter, don't error out, because these aren't universally
         * supported.  (Note: you might think we need to reset the GUC
         * variables to 0 in such a case, but it's not necessary because the
         * show hooks for these variables report the truth anyway.)
         */
        (void) pq_setkeepalivesidle(tcp_keepalives_idle, port);
        (void) pq_setkeepalivesinterval(tcp_keepalives_interval, port);
        (void) pq_setkeepalivescount(tcp_keepalives_count, port);
    }

    return STATUS_OK;
}

int StreamServerPort	(	int	family,
		char *	hostName,
		unsigned short	portNumber,
		char *	unixSocketDir,
		pgsocket	ListenSocket[],
		int	MaxListen
	)

Definition at line 272 of file pqcomm.c.

References _, addrinfo::ai_family, addrinfo::ai_flags, addrinfo::ai_next, addrinfo::ai_socktype, closesocket, ereport, errcode_for_socket_access(), errhint(), errmsg(), gai_strerror, IS_AF_UNIX, LOG, MaxBackends, MemSet, pg_freeaddrinfo_all(), pg_getaddrinfo_all(), PG_SOMAXCONN, PGINVALID_SOCKET, snprintf(), socket, STATUS_OK, UNIXSOCK_PATH, and UNIXSOCK_PATH_BUFLEN.

Referenced by PostmasterMain().

{
    pgsocket    fd;
    int         err;
    int         maxconn;
    int         ret;
    char        portNumberStr[32];
    const char *familyDesc;
    char        familyDescBuf[64];
    char       *service;
    struct addrinfo *addrs = NULL,
               *addr;
    struct addrinfo hint;
    int         listen_index = 0;
    int         added = 0;

#ifdef HAVE_UNIX_SOCKETS
    char        unixSocketPath[MAXPGPATH];
#endif
#if !defined(WIN32) || defined(IPV6_V6ONLY)
    int         one = 1;
#endif

    /* Initialize hint structure */
    MemSet(&hint, 0, sizeof(hint));
    hint.ai_family = family;
    hint.ai_flags = AI_PASSIVE;
    hint.ai_socktype = SOCK_STREAM;

#ifdef HAVE_UNIX_SOCKETS
    if (family == AF_UNIX)
    {
        /*
         * Create unixSocketPath from portNumber and unixSocketDir and lock
         * that file path
         */
        UNIXSOCK_PATH(unixSocketPath, portNumber, unixSocketDir);
        if (strlen(unixSocketPath) >= UNIXSOCK_PATH_BUFLEN)
        {
            ereport(LOG,
                    (errmsg("Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
                            unixSocketPath,
                            (int) (UNIXSOCK_PATH_BUFLEN - 1))));
            return STATUS_ERROR;
        }
        if (Lock_AF_UNIX(unixSocketDir, unixSocketPath) != STATUS_OK)
            return STATUS_ERROR;
        service = unixSocketPath;
    }
    else
#endif   /* HAVE_UNIX_SOCKETS */
    {
        snprintf(portNumberStr, sizeof(portNumberStr), "%d", portNumber);
        service = portNumberStr;
    }

    ret = pg_getaddrinfo_all(hostName, service, &hint, &addrs);
    if (ret || !addrs)
    {
        if (hostName)
            ereport(LOG,
                    (errmsg("could not translate host name \"%s\", service \"%s\" to address: %s",
                            hostName, service, gai_strerror(ret))));
        else
            ereport(LOG,
                 (errmsg("could not translate service \"%s\" to address: %s",
                         service, gai_strerror(ret))));
        if (addrs)
            pg_freeaddrinfo_all(hint.ai_family, addrs);
        return STATUS_ERROR;
    }

    for (addr = addrs; addr; addr = addr->ai_next)
    {
        if (!IS_AF_UNIX(family) && IS_AF_UNIX(addr->ai_family))
        {
            /*
             * Only set up a unix domain socket when they really asked for it.
             * The service/port is different in that case.
             */
            continue;
        }

        /* See if there is still room to add 1 more socket. */
        for (; listen_index < MaxListen; listen_index++)
        {
            if (ListenSocket[listen_index] == PGINVALID_SOCKET)
                break;
        }
        if (listen_index >= MaxListen)
        {
            ereport(LOG,
                    (errmsg("could not bind to all requested addresses: MAXLISTEN (%d) exceeded",
                            MaxListen)));
            break;
        }

        /* set up family name for possible error messages */
        switch (addr->ai_family)
        {
            case AF_INET:
                familyDesc = _("IPv4");
                break;
#ifdef HAVE_IPV6
            case AF_INET6:
                familyDesc = _("IPv6");
                break;
#endif
#ifdef HAVE_UNIX_SOCKETS
            case AF_UNIX:
                familyDesc = _("Unix");
                break;
#endif
            default:
                snprintf(familyDescBuf, sizeof(familyDescBuf),
                         _("unrecognized address family %d"),
                         addr->ai_family);
                familyDesc = familyDescBuf;
                break;
        }

        if ((fd = socket(addr->ai_family, SOCK_STREAM, 0)) < 0)
        {
            ereport(LOG,
                    (errcode_for_socket_access(),
            /* translator: %s is IPv4, IPv6, or Unix */
                     errmsg("could not create %s socket: %m",
                            familyDesc)));
            continue;
        }

#ifndef WIN32

        /*
         * Without the SO_REUSEADDR flag, a new postmaster can't be started
         * right away after a stop or crash, giving "address already in use"
         * error on TCP ports.
         *
         * On win32, however, this behavior only happens if the
         * SO_EXLUSIVEADDRUSE is set. With SO_REUSEADDR, win32 allows multiple
         * servers to listen on the same address, resulting in unpredictable
         * behavior. With no flags at all, win32 behaves as Unix with
         * SO_REUSEADDR.
         */
        if (!IS_AF_UNIX(addr->ai_family))
        {
            if ((setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
                            (char *) &one, sizeof(one))) == -1)
            {
                ereport(LOG,
                        (errcode_for_socket_access(),
                         errmsg("setsockopt(SO_REUSEADDR) failed: %m")));
                closesocket(fd);
                continue;
            }
        }
#endif

#ifdef IPV6_V6ONLY
        if (addr->ai_family == AF_INET6)
        {
            if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
                           (char *) &one, sizeof(one)) == -1)
            {
                ereport(LOG,
                        (errcode_for_socket_access(),
                         errmsg("setsockopt(IPV6_V6ONLY) failed: %m")));
                closesocket(fd);
                continue;
            }
        }
#endif

        /*
         * Note: This might fail on some OS's, like Linux older than
         * 2.4.21-pre3, that don't have the IPV6_V6ONLY socket option, and map
         * ipv4 addresses to ipv6.  It will show ::ffff:ipv4 for all ipv4
         * connections.
         */
        err = bind(fd, addr->ai_addr, addr->ai_addrlen);
        if (err < 0)
        {
            ereport(LOG,
                    (errcode_for_socket_access(),
            /* translator: %s is IPv4, IPv6, or Unix */
                     errmsg("could not bind %s socket: %m",
                            familyDesc),
                     (IS_AF_UNIX(addr->ai_family)) ?
                  errhint("Is another postmaster already running on port %d?"
                          " If not, remove socket file \"%s\" and retry.",
                          (int) portNumber, service) :
                  errhint("Is another postmaster already running on port %d?"
                          " If not, wait a few seconds and retry.",
                          (int) portNumber)));
            closesocket(fd);
            continue;
        }

#ifdef HAVE_UNIX_SOCKETS
        if (addr->ai_family == AF_UNIX)
        {
            if (Setup_AF_UNIX(service) != STATUS_OK)
            {
                closesocket(fd);
                break;
            }
        }
#endif

        /*
         * Select appropriate accept-queue length limit.  PG_SOMAXCONN is only
         * intended to provide a clamp on the request on platforms where an
         * overly large request provokes a kernel error (are there any?).
         */
        maxconn = MaxBackends * 2;
        if (maxconn > PG_SOMAXCONN)
            maxconn = PG_SOMAXCONN;

        err = listen(fd, maxconn);
        if (err < 0)
        {
            ereport(LOG,
                    (errcode_for_socket_access(),
            /* translator: %s is IPv4, IPv6, or Unix */
                     errmsg("could not listen on %s socket: %m",
                            familyDesc)));
            closesocket(fd);
            continue;
        }
        ListenSocket[listen_index] = fd;
        added++;
    }

    pg_freeaddrinfo_all(hint.ai_family, addrs);

    if (!added)
        return STATUS_ERROR;

    return STATUS_OK;
}

void TouchSocketFiles ( void )

Definition at line 750 of file pqcomm.c.

References lfirst, and NULL.

Referenced by ServerLoop().

{
    ListCell   *l;

    /* Loop through all created sockets... */
    foreach(l, sock_paths)
    {
        char       *sock_path = (char *) lfirst(l);

        /*
         * utime() is POSIX standard, utimes() is a common alternative. If we
         * have neither, there's no way to affect the mod or access time of
         * the socket :-(
         *
         * In either path, we ignore errors; there's no point in complaining.
         */
#ifdef HAVE_UTIME
        utime(sock_path, NULL);
#else                           /* !HAVE_UTIME */
#ifdef HAVE_UTIMES
        utimes(sock_path, NULL);
#endif   /* HAVE_UTIMES */
#endif   /* HAVE_UTIME */
    }
}