* the backend's "backend/libpq" is quite separate from "interfaces/libpq".
* All that remains is similarities of names to trap the unwary...
*
- * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/backend/libpq/pqcomm.c
#ifdef HAVE_UTIME_H
#include <utime.h>
#endif
-#ifdef WIN32_ONLY_COMPILER /* mstcpip.h is missing on mingw */
+#ifdef _MSC_VER /* mstcpip.h is missing on mingw */
#include <mstcpip.h>
#endif
-#include "libpq/ip.h"
+#include "common/ip.h"
#include "libpq/libpq.h"
#include "miscadmin.h"
#include "storage/ipc.h"
int Unix_socket_permissions;
char *Unix_socket_group;
-
/* Where the Unix socket files are (list of palloc'd strings) */
static List *sock_paths = NIL;
-
/*
* Buffers for low-level I/O.
*
/*
* Message status
*/
-static bool PqCommBusy;
-static bool DoingCopyOut;
+static bool PqCommBusy; /* busy sending data to the client */
+static bool PqCommReadingMsg; /* in the middle of reading a message */
+static bool DoingCopyOut; /* in old-protocol COPY OUT processing */
/* Internal functions */
-static void pq_close(int code, Datum arg);
+static void socket_comm_reset(void);
+static void socket_close(int code, Datum arg);
+static void socket_set_nonblocking(bool nonblocking);
+static int socket_flush(void);
+static int socket_flush_if_writable(void);
+static bool socket_is_send_pending(void);
+static int socket_putmessage(char msgtype, const char *s, size_t len);
+static void socket_putmessage_noblock(char msgtype, const char *s, size_t len);
+static void socket_startcopyout(void);
+static void socket_endcopyout(bool errorAbort);
static int internal_putbytes(const char *s, size_t len);
static int internal_flush(void);
-static void pq_set_nonblocking(bool nonblocking);
#ifdef HAVE_UNIX_SOCKETS
static int Lock_AF_UNIX(char *unixSocketDir, char *unixSocketPath);
static int Setup_AF_UNIX(char *sock_path);
#endif /* HAVE_UNIX_SOCKETS */
+static PQcommMethods PqCommSocketMethods = {
+ socket_comm_reset,
+ socket_flush,
+ socket_flush_if_writable,
+ socket_is_send_pending,
+ socket_putmessage,
+ socket_putmessage_noblock,
+ socket_startcopyout,
+ socket_endcopyout
+};
+
+PQcommMethods *PqCommMethods = &PqCommSocketMethods;
+
+WaitEventSet *FeBeWaitSet;
+
/* --------------------------------
* pq_init - initialize libpq at backend startup
void
pq_init(void)
{
+ /* initialize state variables */
PqSendBufferSize = PQ_SEND_BUFFER_SIZE;
PqSendBuffer = MemoryContextAlloc(TopMemoryContext, PqSendBufferSize);
PqSendPointer = PqSendStart = PqRecvPointer = PqRecvLength = 0;
PqCommBusy = false;
+ PqCommReadingMsg = false;
DoingCopyOut = false;
- on_proc_exit(pq_close, 0);
+
+ /* set up process-exit hook to close the socket */
+ on_proc_exit(socket_close, 0);
+
+ /*
+ * In backends (as soon as forked) we operate the underlying socket in
+ * nonblocking mode and use latches to implement blocking semantics if
+ * needed. That allows us to provide safely interruptible reads and
+ * writes.
+ *
+ * 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.
+ */
+#ifndef WIN32
+ if (!pg_set_noblock(MyProcPort->sock))
+ ereport(COMMERROR,
+ (errmsg("could not set socket to nonblocking mode: %m")));
+#endif
+
+ FeBeWaitSet = CreateWaitEventSet(TopMemoryContext, 3);
+ AddWaitEventToSet(FeBeWaitSet, WL_SOCKET_WRITEABLE, MyProcPort->sock,
+ NULL, NULL);
+ AddWaitEventToSet(FeBeWaitSet, WL_LATCH_SET, -1, MyLatch, NULL);
+ AddWaitEventToSet(FeBeWaitSet, WL_POSTMASTER_DEATH, -1, NULL, NULL);
}
/* --------------------------------
- * pq_comm_reset - reset libpq during error recovery
+ * socket_comm_reset - reset libpq during error recovery
*
* This is called from error recovery at the outer idle loop. It's
* just to get us out of trouble if we somehow manage to elog() from
* inside a pqcomm.c routine (which ideally will never happen, but...)
* --------------------------------
*/
-void
-pq_comm_reset(void)
+static void
+socket_comm_reset(void)
{
/* Do not throw away pending data, but do reset the busy flag */
PqCommBusy = false;
}
/* --------------------------------
- * pq_close - shutdown libpq at backend exit
+ * socket_close - shutdown libpq at backend exit
*
- * Note: in a standalone backend MyProcPort will be null,
- * don't crash during exit...
+ * This is the one pg_on_exit_callback in place during BackendInitialize().
+ * That function's unusual signal handling constrains that this callback be
+ * safe to run at any instant.
* --------------------------------
*/
static void
-pq_close(int code, Datum arg)
+socket_close(int code, Datum arg)
{
+ /* Nothing to do in a standalone backend, where MyProcPort is NULL. */
if (MyProcPort != NULL)
{
#if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
#ifdef ENABLE_GSS
OM_uint32 min_s;
- /* Shutdown GSSAPI layer */
+ /*
+ * Shutdown GSSAPI layer. This section does nothing when interrupting
+ * BackendInitialize(), because pg_GSS_recvauth() makes first use of
+ * "ctx" and "cred".
+ */
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 */
+ /*
+ * GSS and SSPI share the port->gss struct. Since nowhere else does a
+ * postmaster child free this, doing so is safe when interrupting
+ * BackendInitialize().
+ */
free(MyProcPort->gss);
#endif /* ENABLE_GSS || ENABLE_SSPI */
- /* Cleanly shut down SSL layer */
+ /*
+ * Cleanly shut down SSL layer. Nowhere else does a postmaster child
+ * call this, so this is safe when interrupting BackendInitialize().
+ */
secure_close(MyProcPort);
/*
*/
-/* StreamDoUnlink()
- * Shutdown routine for backend connection
- * If any Unix sockets are used for communication, explicitly close them.
- */
-#ifdef HAVE_UNIX_SOCKETS
-static void
-StreamDoUnlink(int code, Datum arg)
-{
- ListCell *l;
-
- /* Loop through all created sockets... */
- foreach(l, sock_paths)
- {
- char *sock_path = (char *) lfirst(l);
-
- unlink(sock_path);
- }
- /* Since we're about to exit, no need to reclaim storage */
- sock_paths = NIL;
-}
-#endif /* HAVE_UNIX_SOCKETS */
-
/*
* StreamServerPort -- open a "listening" port to accept connections.
*
char portNumberStr[32];
const char *familyDesc;
char familyDescBuf[64];
+ const char *addrDesc;
+ char addrBuf[NI_MAXHOST];
char *service;
struct addrinfo *addrs = NULL,
*addr;
break;
}
- /* set up family name for possible error messages */
+ /* set up address family name for log messages */
switch (addr->ai_family)
{
case AF_INET:
break;
}
- if ((fd = socket(addr->ai_family, SOCK_STREAM, 0)) < 0)
+ /* set up text form of address for log messages */
+#ifdef HAVE_UNIX_SOCKETS
+ if (addr->ai_family == AF_UNIX)
+ addrDesc = unixSocketPath;
+ else
+#endif
+ {
+ pg_getnameinfo_all((const struct sockaddr_storage *) addr->ai_addr,
+ addr->ai_addrlen,
+ addrBuf, sizeof(addrBuf),
+ NULL, 0,
+ NI_NUMERICHOST);
+ addrDesc = addrBuf;
+ }
+
+ if ((fd = socket(addr->ai_family, SOCK_STREAM, 0)) == PGINVALID_SOCKET)
{
ereport(LOG,
(errcode_for_socket_access(),
- /* translator: %s is IPv4, IPv6, or Unix */
- errmsg("could not create %s socket: %m",
- familyDesc)));
+ /* translator: first %s is IPv4, IPv6, or Unix */
+ errmsg("could not create %s socket for address \"%s\": %m",
+ familyDesc, addrDesc)));
continue;
}
{
ereport(LOG,
(errcode_for_socket_access(),
- errmsg("setsockopt(SO_REUSEADDR) failed: %m")));
+ /* translator: first %s is IPv4, IPv6, or Unix */
+ errmsg("setsockopt(SO_REUSEADDR) failed for %s address \"%s\": %m",
+ familyDesc, addrDesc)));
closesocket(fd);
continue;
}
{
ereport(LOG,
(errcode_for_socket_access(),
- errmsg("setsockopt(IPV6_V6ONLY) failed: %m")));
+ /* translator: first %s is IPv4, IPv6, or Unix */
+ errmsg("setsockopt(IPV6_V6ONLY) failed for %s address \"%s\": %m",
+ familyDesc, addrDesc)));
closesocket(fd);
continue;
}
/*
* 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
+ * ipv4 addresses to ipv6. It will show ::ffff:ipv4 for all ipv4
* connections.
*/
err = bind(fd, addr->ai_addr, addr->ai_addrlen);
{
ereport(LOG,
(errcode_for_socket_access(),
- /* translator: %s is IPv4, IPv6, or Unix */
- errmsg("could not bind %s socket: %m",
- familyDesc),
+ /* translator: first %s is IPv4, IPv6, or Unix */
+ errmsg("could not bind %s address \"%s\": %m",
+ familyDesc, addrDesc),
(IS_AF_UNIX(addr->ai_family)) ?
errhint("Is another postmaster already running on port %d?"
" If not, remove socket file \"%s\" and retry.",
{
ereport(LOG,
(errcode_for_socket_access(),
- /* translator: %s is IPv4, IPv6, or Unix */
- errmsg("could not listen on %s socket: %m",
- familyDesc)));
+ /* translator: first %s is IPv4, IPv6, or Unix */
+ errmsg("could not listen on %s address \"%s\": %m",
+ familyDesc, addrDesc)));
closesocket(fd);
continue;
}
+
+#ifdef HAVE_UNIX_SOCKETS
+ if (addr->ai_family == AF_UNIX)
+ ereport(LOG,
+ (errmsg("listening on Unix socket \"%s\"",
+ addrDesc)));
+ else
+#endif
+ ereport(LOG,
+ /* translator: first %s is IPv4 or IPv6 */
+ (errmsg("listening on %s address \"%s\", port %d",
+ familyDesc, addrDesc, (int) portNumber)));
+
ListenSocket[listen_index] = fd;
added++;
}
* Once we have the interlock, we can safely delete any pre-existing
* socket file to avoid failure at bind() time.
*/
- unlink(unixSocketPath);
+ (void) unlink(unixSocketPath);
/*
- * Arrange to unlink the socket file(s) at proc_exit. If this is the
- * first one, set up the on_proc_exit function to do it; then add this
- * socket file to the list of files to unlink.
+ * Remember socket file pathnames for later maintenance.
*/
- if (sock_paths == NIL)
- on_proc_exit(StreamDoUnlink, 0);
-
sock_paths = lappend(sock_paths, pstrdup(unixSocketPath));
return STATUS_OK;
port->raddr.salen = sizeof(port->raddr.addr);
if ((port->sock = accept(server_fd,
(struct sockaddr *) & port->raddr.addr,
- &port->raddr.salen)) < 0)
+ &port->raddr.salen)) == PGINVALID_SOCKET)
{
ereport(LOG,
(errcode_for_socket_access(),
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,
if (!IS_AF_UNIX(port->laddr.addr.ss_family))
{
int on;
+#ifdef WIN32
+ int oldopt;
+ int optlen;
+ int newopt;
+#endif
#ifdef TCP_NODELAY
on = 1;
#ifdef WIN32
/*
- * This is a Win32 socket optimization. The ideal size is 32k.
- * http://support.microsoft.com/kb/823764/EN-US/
+ * This is a Win32 socket optimization. The OS send buffer should be
+ * large enough to send the whole Postgres send buffer in one go, or
+ * performance suffers. The Postgres send buffer can be enlarged if a
+ * very large message needs to be sent, but we won't attempt to
+ * enlarge the OS buffer if that happens, so somewhat arbitrarily
+ * ensure that the OS buffer is at least PQ_SEND_BUFFER_SIZE * 4.
+ * (That's 32kB with the current default).
+ *
+ * The default OS buffer size used to be 8kB in earlier Windows
+ * versions, but was raised to 64kB in Windows 2012. So it shouldn't
+ * be necessary to change it in later versions anymore. Changing it
+ * unnecessarily can even reduce performance, because setting
+ * SO_SNDBUF in the application disables the "dynamic send buffering"
+ * feature that was introduced in Windows 7. So before fiddling with
+ * SO_SNDBUF, check if the current buffer size is already large enough
+ * and only increase it if necessary.
+ *
+ * See https://support.microsoft.com/kb/823764/EN-US/ and
+ * https://msdn.microsoft.com/en-us/library/bb736549%28v=vs.85%29.aspx
*/
- on = PQ_SEND_BUFFER_SIZE * 4;
- if (setsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &on,
- sizeof(on)) < 0)
+ optlen = sizeof(oldopt);
+ if (getsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &oldopt,
+ &optlen) < 0)
{
- elog(LOG, "setsockopt(SO_SNDBUF) failed: %m");
+ elog(LOG, "getsockopt(SO_SNDBUF) failed: %m");
return STATUS_ERROR;
}
+ newopt = PQ_SEND_BUFFER_SIZE * 4;
+ if (oldopt < newopt)
+ {
+ if (setsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &newopt,
+ sizeof(newopt)) < 0)
+ {
+ elog(LOG, "setsockopt(SO_SNDBUF) failed: %m");
+ return STATUS_ERROR;
+ }
+ }
#endif
/*
}
}
+/*
+ * RemoveSocketFiles -- unlink socket files at postmaster shutdown
+ */
+void
+RemoveSocketFiles(void)
+{
+ ListCell *l;
+
+ /* Loop through all created sockets... */
+ foreach(l, sock_paths)
+ {
+ char *sock_path = (char *) lfirst(l);
+
+ /* Ignore any error. */
+ (void) unlink(sock_path);
+ }
+ /* Since we're about to exit, no need to reclaim storage */
+ sock_paths = NIL;
+}
+
/* --------------------------------
* Low-level I/O routines begin here.
*/
/* --------------------------------
- * pq_set_nonblocking - set socket blocking/non-blocking
+ * socket_set_nonblocking - set socket blocking/non-blocking
*
* Sets the socket non-blocking if nonblocking is TRUE, or sets it
* blocking otherwise.
* --------------------------------
*/
static void
-pq_set_nonblocking(bool nonblocking)
+socket_set_nonblocking(bool nonblocking)
{
- if (MyProcPort->noblock == nonblocking)
- return;
-
-#ifdef WIN32
- pgwin32_noblock = nonblocking ? 1 : 0;
-#else
+ if (MyProcPort == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
+ errmsg("there is no client connection")));
- /*
- * 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 non-blocking mode: %m")));
- }
- else
- {
- if (!pg_set_block(MyProcPort->sock))
- ereport(COMMERROR,
- (errmsg("could not set socket to blocking mode: %m")));
- }
-#endif
MyProcPort->noblock = nonblocking;
}
}
/* Ensure that we're in blocking mode */
- pq_set_nonblocking(false);
+ socket_set_nonblocking(false);
/* Can fill buffer from PqRecvLength and upwards */
for (;;)
int
pq_getbyte(void)
{
+ Assert(PqCommReadingMsg);
+
while (PqRecvPointer >= PqRecvLength)
{
if (pq_recvbuf()) /* If nothing in buffer, then recv some */
int
pq_peekbyte(void)
{
+ Assert(PqCommReadingMsg);
+
while (PqRecvPointer >= PqRecvLength)
{
if (pq_recvbuf()) /* If nothing in buffer, then recv some */
{
int r;
+ Assert(PqCommReadingMsg);
+
if (PqRecvPointer < PqRecvLength)
{
*c = PqRecvBuffer[PqRecvPointer++];
}
/* Put the socket into non-blocking mode */
- pq_set_nonblocking(true);
+ socket_set_nonblocking(true);
r = secure_read(MyProcPort, c, 1);
if (r < 0)
{
size_t amount;
+ Assert(PqCommReadingMsg);
+
while (len > 0)
{
while (PqRecvPointer >= PqRecvLength)
{
size_t amount;
+ Assert(PqCommReadingMsg);
+
while (len > 0)
{
while (PqRecvPointer >= PqRecvLength)
{
int i;
+ Assert(PqCommReadingMsg);
+
resetStringInfo(s);
/* Read until we get the terminating '\0' */
}
+/* --------------------------------
+ * pq_startmsgread - begin reading a message from the client.
+ *
+ * This must be called before any of the pq_get* functions.
+ * --------------------------------
+ */
+void
+pq_startmsgread(void)
+{
+ /*
+ * There shouldn't be a read active already, but let's check just to be
+ * sure.
+ */
+ if (PqCommReadingMsg)
+ ereport(FATAL,
+ (errcode(ERRCODE_PROTOCOL_VIOLATION),
+ errmsg("terminating connection because protocol synchronization was lost")));
+
+ PqCommReadingMsg = true;
+}
+
+
+/* --------------------------------
+ * pq_endmsgread - finish reading message.
+ *
+ * This must be called after reading a V2 protocol message with
+ * pq_getstring() and friends, to indicate that we have read the whole
+ * message. In V3 protocol, pq_getmessage() does this implicitly.
+ * --------------------------------
+ */
+void
+pq_endmsgread(void)
+{
+ Assert(PqCommReadingMsg);
+
+ PqCommReadingMsg = false;
+}
+
+/* --------------------------------
+ * pq_is_reading_msg - are we currently reading a message?
+ *
+ * This is used in error recovery at the outer idle loop to detect if we have
+ * lost protocol sync, and need to terminate the connection. pq_startmsgread()
+ * will check for that too, but it's nicer to detect it earlier.
+ * --------------------------------
+ */
+bool
+pq_is_reading_msg(void)
+{
+ return PqCommReadingMsg;
+}
+
/* --------------------------------
* pq_getmessage - get a message with length word from connection
*
{
int32 len;
+ Assert(PqCommReadingMsg);
+
resetStringInfo(s);
/* Read message length word */
if (len > 0)
{
/*
- * Allocate space for message. If we run out of room (ridiculously
+ * 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.
*/
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("incomplete message from client")));
+
+ /* we discarded the rest of the message so we're back in sync. */
+ PqCommReadingMsg = false;
PG_RE_THROW();
}
PG_END_TRY();
s->data[len] = '\0';
}
+ /* finished reading the message. */
+ PqCommReadingMsg = false;
+
return 0;
}
/* If buffer is full, then flush it out */
if (PqSendPointer >= PqSendBufferSize)
{
- pq_set_nonblocking(false);
+ socket_set_nonblocking(false);
if (internal_flush())
return EOF;
}
}
/* --------------------------------
- * pq_flush - flush pending output
+ * socket_flush - flush pending output
*
* returns 0 if OK, EOF if trouble
* --------------------------------
*/
-int
-pq_flush(void)
+static int
+socket_flush(void)
{
int res;
if (PqCommBusy)
return 0;
PqCommBusy = true;
- pq_set_nonblocking(false);
+ socket_set_nonblocking(false);
res = internal_flush();
PqCommBusy = false;
return res;
* Returns 0 if OK, or EOF if trouble.
* --------------------------------
*/
-int
-pq_flush_if_writable(void)
+static int
+socket_flush_if_writable(void)
{
int res;
return 0;
/* Temporarily put the socket into non-blocking mode */
- pq_set_nonblocking(true);
+ socket_set_nonblocking(true);
PqCommBusy = true;
res = internal_flush();
}
/* --------------------------------
- * pq_is_send_pending - is there any pending data in the output buffer?
+ * socket_is_send_pending - is there any pending data in the output buffer?
* --------------------------------
*/
-bool
-pq_is_send_pending(void)
+static bool
+socket_is_send_pending(void)
{
return (PqSendStart < PqSendPointer);
}
/* --------------------------------
- * pq_putmessage - send a normal message (suppressed in COPY OUT mode)
+ * socket_putmessage - send a normal message (suppressed in COPY OUT mode)
*
* If msgtype is not '\0', it is a message type code to place before
* the message body. If msgtype is '\0', then the message has no type
* returns 0 if OK, EOF if trouble
* --------------------------------
*/
-int
-pq_putmessage(char msgtype, const char *s, size_t len)
+static int
+socket_putmessage(char msgtype, const char *s, size_t len)
{
if (DoingCopyOut || PqCommBusy)
return 0;
* If the output buffer is too small to hold the message, the buffer
* is enlarged.
*/
-void
-pq_putmessage_noblock(char msgtype, const char *s, size_t len)
+static void
+socket_putmessage_noblock(char msgtype, const char *s, size_t len)
{
int res PG_USED_FOR_ASSERTS_ONLY;
int required;
/* --------------------------------
- * pq_startcopyout - inform libpq that an old-style COPY OUT transfer
+ * socket_startcopyout - inform libpq that an old-style COPY OUT transfer
* is beginning
* --------------------------------
*/
-void
-pq_startcopyout(void)
+static void
+socket_startcopyout(void)
{
DoingCopyOut = true;
}
/* --------------------------------
- * pq_endcopyout - end an old-style COPY OUT transfer
+ * socket_endcopyout - end an old-style COPY OUT transfer
*
* If errorAbort is indicated, we are aborting a COPY OUT due to an error,
* and must send a terminator line. Since a partial data line might have
* not allow binary transfers, so a textual terminator is always correct.
* --------------------------------
*/
-void
-pq_endcopyout(bool errorAbort)
+static void
+socket_endcopyout(bool errorAbort)
{
if (!DoingCopyOut)
return;
DoingCopyOut = false;
}
-
/*
* Support for TCP Keepalive parameters
*/
/*
* On Windows, we need to set both idle and interval at the same time.
* We also cannot reset them to the default (setting to zero will
- * actually set them to zero, not default), therefor we fallback to
+ * actually set them to zero, not default), therefore we fallback to
* the out-of-the-box default instead.
*/
#if defined(WIN32) && defined(SIO_KEEPALIVE_VALS)
projects / postgresql / blobdiff