PostgreSQL Source Code  git master
pqcomm.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pqcomm.c
4  * Communication functions between the Frontend and the Backend
5  *
6  * These routines handle the low-level details of communication between
7  * frontend and backend. They just shove data across the communication
8  * channel, and are ignorant of the semantics of the data.
9  *
10  * To emit an outgoing message, use the routines in pqformat.c to construct
11  * the message in a buffer and then emit it in one call to pq_putmessage.
12  * There are no functions to send raw bytes or partial messages; this
13  * ensures that the channel will not be clogged by an incomplete message if
14  * execution is aborted by ereport(ERROR) partway through the message.
15  *
16  * At one time, libpq was shared between frontend and backend, but now
17  * the backend's "backend/libpq" is quite separate from "interfaces/libpq".
18  * All that remains is similarities of names to trap the unwary...
19  *
20  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
21  * Portions Copyright (c) 1994, Regents of the University of California
22  *
23  * src/backend/libpq/pqcomm.c
24  *
25  *-------------------------------------------------------------------------
26  */
27 
28 /*------------------------
29  * INTERFACE ROUTINES
30  *
31  * setup/teardown:
32  * StreamServerPort - Open postmaster's server port
33  * StreamConnection - Create new connection with client
34  * StreamClose - Close a client/backend connection
35  * TouchSocketFiles - Protect socket files against /tmp cleaners
36  * pq_init - initialize libpq at backend startup
37  * socket_comm_reset - reset libpq during error recovery
38  * socket_close - shutdown libpq at backend exit
39  *
40  * low-level I/O:
41  * pq_getbytes - get a known number of bytes from connection
42  * pq_getmessage - get a message with length word from connection
43  * pq_getbyte - get next byte from connection
44  * pq_peekbyte - peek at next byte from connection
45  * pq_flush - flush pending output
46  * pq_flush_if_writable - flush pending output if writable without blocking
47  * pq_getbyte_if_available - get a byte if available without blocking
48  *
49  * message-level I/O
50  * pq_putmessage - send a normal message (suppressed in COPY OUT mode)
51  * pq_putmessage_noblock - buffer a normal message (suppressed in COPY OUT)
52  *
53  *------------------------
54  */
55 #include "postgres.h"
56 
57 #ifdef HAVE_POLL_H
58 #include <poll.h>
59 #endif
60 #include <signal.h>
61 #include <fcntl.h>
62 #include <grp.h>
63 #include <unistd.h>
64 #include <sys/file.h>
65 #include <sys/socket.h>
66 #include <sys/stat.h>
67 #include <sys/time.h>
68 #include <netdb.h>
69 #include <netinet/in.h>
70 #include <netinet/tcp.h>
71 #include <utime.h>
72 #ifdef WIN32
73 #include <mstcpip.h>
74 #endif
75 
76 #include "common/ip.h"
77 #include "libpq/libpq.h"
78 #include "miscadmin.h"
79 #include "port/pg_bswap.h"
80 #include "storage/ipc.h"
81 #include "utils/guc_hooks.h"
82 #include "utils/memutils.h"
83 
84 /*
85  * Cope with the various platform-specific ways to spell TCP keepalive socket
86  * options. This doesn't cover Windows, which as usual does its own thing.
87  */
88 #if defined(TCP_KEEPIDLE)
89 /* TCP_KEEPIDLE is the name of this option on Linux and *BSD */
90 #define PG_TCP_KEEPALIVE_IDLE TCP_KEEPIDLE
91 #define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPIDLE"
92 #elif defined(TCP_KEEPALIVE_THRESHOLD)
93 /* TCP_KEEPALIVE_THRESHOLD is the name of this option on Solaris >= 11 */
94 #define PG_TCP_KEEPALIVE_IDLE TCP_KEEPALIVE_THRESHOLD
95 #define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPALIVE_THRESHOLD"
96 #elif defined(TCP_KEEPALIVE) && defined(__darwin__)
97 /* TCP_KEEPALIVE is the name of this option on macOS */
98 /* Caution: Solaris has this symbol but it means something different */
99 #define PG_TCP_KEEPALIVE_IDLE TCP_KEEPALIVE
100 #define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPALIVE"
101 #endif
102 
103 /*
104  * Configuration options
105  */
108 
109 /* Where the Unix socket files are (list of palloc'd strings) */
110 static List *sock_paths = NIL;
111 
112 /*
113  * Buffers for low-level I/O.
114  *
115  * The receive buffer is fixed size. Send buffer is usually 8k, but can be
116  * enlarged by pq_putmessage_noblock() if the message doesn't fit otherwise.
117  */
118 
119 #define PQ_SEND_BUFFER_SIZE 8192
120 #define PQ_RECV_BUFFER_SIZE 8192
121 
122 static char *PqSendBuffer;
123 static int PqSendBufferSize; /* Size send buffer */
124 static int PqSendPointer; /* Next index to store a byte in PqSendBuffer */
125 static int PqSendStart; /* Next index to send a byte in PqSendBuffer */
126 
128 static int PqRecvPointer; /* Next index to read a byte from PqRecvBuffer */
129 static int PqRecvLength; /* End of data available in PqRecvBuffer */
130 
131 /*
132  * Message status
133  */
134 static bool PqCommBusy; /* busy sending data to the client */
135 static bool PqCommReadingMsg; /* in the middle of reading a message */
136 
137 
138 /* Internal functions */
139 static void socket_comm_reset(void);
140 static void socket_close(int code, Datum arg);
141 static void socket_set_nonblocking(bool nonblocking);
142 static int socket_flush(void);
143 static int socket_flush_if_writable(void);
144 static bool socket_is_send_pending(void);
145 static int socket_putmessage(char msgtype, const char *s, size_t len);
146 static void socket_putmessage_noblock(char msgtype, const char *s, size_t len);
147 static int internal_putbytes(const char *s, size_t len);
148 static int internal_flush(void);
149 
150 static int Lock_AF_UNIX(const char *unixSocketDir, const char *unixSocketPath);
151 static int Setup_AF_UNIX(const char *sock_path);
152 
155  .flush = socket_flush,
156  .flush_if_writable = socket_flush_if_writable,
157  .is_send_pending = socket_is_send_pending,
158  .putmessage = socket_putmessage,
159  .putmessage_noblock = socket_putmessage_noblock
160 };
161 
163 
165 
166 
167 /* --------------------------------
168  * pq_init - initialize libpq at backend startup
169  * --------------------------------
170  */
171 void
172 pq_init(void)
173 {
174  int socket_pos PG_USED_FOR_ASSERTS_ONLY;
175  int latch_pos PG_USED_FOR_ASSERTS_ONLY;
176 
177  /* initialize state variables */
181  PqCommBusy = false;
182  PqCommReadingMsg = false;
183 
184  /* set up process-exit hook to close the socket */
186 
187  /*
188  * In backends (as soon as forked) we operate the underlying socket in
189  * nonblocking mode and use latches to implement blocking semantics if
190  * needed. That allows us to provide safely interruptible reads and
191  * writes.
192  *
193  * Use COMMERROR on failure, because ERROR would try to send the error to
194  * the client, which might require changing the mode again, leading to
195  * infinite recursion.
196  */
197 #ifndef WIN32
200  (errmsg("could not set socket to nonblocking mode: %m")));
201 #endif
202 
203 #ifndef WIN32
204 
205  /* Don't give the socket to any subprograms we execute. */
206  if (fcntl(MyProcPort->sock, F_SETFD, FD_CLOEXEC) < 0)
207  elog(FATAL, "fcntl(F_SETFD) failed on socket: %m");
208 #endif
209 
212  MyProcPort->sock, NULL, NULL);
214  MyLatch, NULL);
216  NULL, NULL);
217 
218  /*
219  * The event positions match the order we added them, but let's sanity
220  * check them to be sure.
221  */
222  Assert(socket_pos == FeBeWaitSetSocketPos);
223  Assert(latch_pos == FeBeWaitSetLatchPos);
224 }
225 
226 /* --------------------------------
227  * socket_comm_reset - reset libpq during error recovery
228  *
229  * This is called from error recovery at the outer idle loop. It's
230  * just to get us out of trouble if we somehow manage to elog() from
231  * inside a pqcomm.c routine (which ideally will never happen, but...)
232  * --------------------------------
233  */
234 static void
236 {
237  /* Do not throw away pending data, but do reset the busy flag */
238  PqCommBusy = false;
239 }
240 
241 /* --------------------------------
242  * socket_close - shutdown libpq at backend exit
243  *
244  * This is the one pg_on_exit_callback in place during BackendInitialize().
245  * That function's unusual signal handling constrains that this callback be
246  * safe to run at any instant.
247  * --------------------------------
248  */
249 static void
251 {
252  /* Nothing to do in a standalone backend, where MyProcPort is NULL. */
253  if (MyProcPort != NULL)
254  {
255 #ifdef ENABLE_GSS
256  /*
257  * Shutdown GSSAPI layer. This section does nothing when interrupting
258  * BackendInitialize(), because pg_GSS_recvauth() makes first use of
259  * "ctx" and "cred".
260  *
261  * Note that we don't bother to free MyProcPort->gss, since we're
262  * about to exit anyway.
263  */
264  if (MyProcPort->gss)
265  {
266  OM_uint32 min_s;
267 
268  if (MyProcPort->gss->ctx != GSS_C_NO_CONTEXT)
269  gss_delete_sec_context(&min_s, &MyProcPort->gss->ctx, NULL);
270 
271  if (MyProcPort->gss->cred != GSS_C_NO_CREDENTIAL)
272  gss_release_cred(&min_s, &MyProcPort->gss->cred);
273  }
274 #endif /* ENABLE_GSS */
275 
276  /*
277  * Cleanly shut down SSL layer. Nowhere else does a postmaster child
278  * call this, so this is safe when interrupting BackendInitialize().
279  */
281 
282  /*
283  * Formerly we did an explicit close() here, but it seems better to
284  * leave the socket open until the process dies. This allows clients
285  * to perform a "synchronous close" if they care --- wait till the
286  * transport layer reports connection closure, and you can be sure the
287  * backend has exited.
288  *
289  * We do set sock to PGINVALID_SOCKET to prevent any further I/O,
290  * though.
291  */
293  }
294 }
295 
296 
297 
298 /*
299  * Streams -- wrapper around Unix socket system calls
300  *
301  *
302  * Stream functions are used for vanilla TCP connection protocol.
303  */
304 
305 
306 /*
307  * StreamServerPort -- open a "listening" port to accept connections.
308  *
309  * family should be AF_UNIX or AF_UNSPEC; portNumber is the port number.
310  * For AF_UNIX ports, hostName should be NULL and unixSocketDir must be
311  * specified. For TCP ports, hostName is either NULL for all interfaces or
312  * the interface to listen on, and unixSocketDir is ignored (can be NULL).
313  *
314  * Successfully opened sockets are appended to the ListenSockets[] array. On
315  * entry, *NumListenSockets holds the number of elements currently in the
316  * array, and it is updated to reflect the opened sockets. MaxListen is the
317  * allocated size of the array.
318  *
319  * RETURNS: STATUS_OK or STATUS_ERROR
320  */
321 int
322 StreamServerPort(int family, const char *hostName, unsigned short portNumber,
323  const char *unixSocketDir,
324  pgsocket ListenSockets[], int *NumListenSockets, int MaxListen)
325 {
326  pgsocket fd;
327  int err;
328  int maxconn;
329  int ret;
330  char portNumberStr[32];
331  const char *familyDesc;
332  char familyDescBuf[64];
333  const char *addrDesc;
334  char addrBuf[NI_MAXHOST];
335  char *service;
336  struct addrinfo *addrs = NULL,
337  *addr;
338  struct addrinfo hint;
339  int added = 0;
340  char unixSocketPath[MAXPGPATH];
341 #if !defined(WIN32) || defined(IPV6_V6ONLY)
342  int one = 1;
343 #endif
344 
345  /* Initialize hint structure */
346  MemSet(&hint, 0, sizeof(hint));
347  hint.ai_family = family;
348  hint.ai_flags = AI_PASSIVE;
349  hint.ai_socktype = SOCK_STREAM;
350 
351  if (family == AF_UNIX)
352  {
353  /*
354  * Create unixSocketPath from portNumber and unixSocketDir and lock
355  * that file path
356  */
357  UNIXSOCK_PATH(unixSocketPath, portNumber, unixSocketDir);
358  if (strlen(unixSocketPath) >= UNIXSOCK_PATH_BUFLEN)
359  {
360  ereport(LOG,
361  (errmsg("Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
362  unixSocketPath,
363  (int) (UNIXSOCK_PATH_BUFLEN - 1))));
364  return STATUS_ERROR;
365  }
366  if (Lock_AF_UNIX(unixSocketDir, unixSocketPath) != STATUS_OK)
367  return STATUS_ERROR;
368  service = unixSocketPath;
369  }
370  else
371  {
372  snprintf(portNumberStr, sizeof(portNumberStr), "%d", portNumber);
373  service = portNumberStr;
374  }
375 
376  ret = pg_getaddrinfo_all(hostName, service, &hint, &addrs);
377  if (ret || !addrs)
378  {
379  if (hostName)
380  ereport(LOG,
381  (errmsg("could not translate host name \"%s\", service \"%s\" to address: %s",
382  hostName, service, gai_strerror(ret))));
383  else
384  ereport(LOG,
385  (errmsg("could not translate service \"%s\" to address: %s",
386  service, gai_strerror(ret))));
387  if (addrs)
388  pg_freeaddrinfo_all(hint.ai_family, addrs);
389  return STATUS_ERROR;
390  }
391 
392  for (addr = addrs; addr; addr = addr->ai_next)
393  {
394  if (family != AF_UNIX && addr->ai_family == AF_UNIX)
395  {
396  /*
397  * Only set up a unix domain socket when they really asked for it.
398  * The service/port is different in that case.
399  */
400  continue;
401  }
402 
403  /* See if there is still room to add 1 more socket. */
404  if (*NumListenSockets == MaxListen)
405  {
406  ereport(LOG,
407  (errmsg("could not bind to all requested addresses: MAXLISTEN (%d) exceeded",
408  MaxListen)));
409  break;
410  }
411 
412  /* set up address family name for log messages */
413  switch (addr->ai_family)
414  {
415  case AF_INET:
416  familyDesc = _("IPv4");
417  break;
418  case AF_INET6:
419  familyDesc = _("IPv6");
420  break;
421  case AF_UNIX:
422  familyDesc = _("Unix");
423  break;
424  default:
425  snprintf(familyDescBuf, sizeof(familyDescBuf),
426  _("unrecognized address family %d"),
427  addr->ai_family);
428  familyDesc = familyDescBuf;
429  break;
430  }
431 
432  /* set up text form of address for log messages */
433  if (addr->ai_family == AF_UNIX)
434  addrDesc = unixSocketPath;
435  else
436  {
437  pg_getnameinfo_all((const struct sockaddr_storage *) addr->ai_addr,
438  addr->ai_addrlen,
439  addrBuf, sizeof(addrBuf),
440  NULL, 0,
441  NI_NUMERICHOST);
442  addrDesc = addrBuf;
443  }
444 
445  if ((fd = socket(addr->ai_family, SOCK_STREAM, 0)) == PGINVALID_SOCKET)
446  {
447  ereport(LOG,
449  /* translator: first %s is IPv4, IPv6, or Unix */
450  errmsg("could not create %s socket for address \"%s\": %m",
451  familyDesc, addrDesc)));
452  continue;
453  }
454 
455 #ifndef WIN32
456  /* Don't give the listen socket to any subprograms we execute. */
457  if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0)
458  elog(FATAL, "fcntl(F_SETFD) failed on socket: %m");
459 
460  /*
461  * Without the SO_REUSEADDR flag, a new postmaster can't be started
462  * right away after a stop or crash, giving "address already in use"
463  * error on TCP ports.
464  *
465  * On win32, however, this behavior only happens if the
466  * SO_EXCLUSIVEADDRUSE is set. With SO_REUSEADDR, win32 allows
467  * multiple servers to listen on the same address, resulting in
468  * unpredictable behavior. With no flags at all, win32 behaves as Unix
469  * with SO_REUSEADDR.
470  */
471  if (addr->ai_family != AF_UNIX)
472  {
473  if ((setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
474  (char *) &one, sizeof(one))) == -1)
475  {
476  ereport(LOG,
478  /* translator: third %s is IPv4, IPv6, or Unix */
479  errmsg("%s(%s) failed for %s address \"%s\": %m",
480  "setsockopt", "SO_REUSEADDR",
481  familyDesc, addrDesc)));
482  closesocket(fd);
483  continue;
484  }
485  }
486 #endif
487 
488 #ifdef IPV6_V6ONLY
489  if (addr->ai_family == AF_INET6)
490  {
491  if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
492  (char *) &one, sizeof(one)) == -1)
493  {
494  ereport(LOG,
496  /* translator: third %s is IPv4, IPv6, or Unix */
497  errmsg("%s(%s) failed for %s address \"%s\": %m",
498  "setsockopt", "IPV6_V6ONLY",
499  familyDesc, addrDesc)));
500  closesocket(fd);
501  continue;
502  }
503  }
504 #endif
505 
506  /*
507  * Note: This might fail on some OS's, like Linux older than
508  * 2.4.21-pre3, that don't have the IPV6_V6ONLY socket option, and map
509  * ipv4 addresses to ipv6. It will show ::ffff:ipv4 for all ipv4
510  * connections.
511  */
512  err = bind(fd, addr->ai_addr, addr->ai_addrlen);
513  if (err < 0)
514  {
515  int saved_errno = errno;
516 
517  ereport(LOG,
519  /* translator: first %s is IPv4, IPv6, or Unix */
520  errmsg("could not bind %s address \"%s\": %m",
521  familyDesc, addrDesc),
522  saved_errno == EADDRINUSE ?
523  (addr->ai_family == AF_UNIX ?
524  errhint("Is another postmaster already running on port %d?",
525  (int) portNumber) :
526  errhint("Is another postmaster already running on port %d?"
527  " If not, wait a few seconds and retry.",
528  (int) portNumber)) : 0));
529  closesocket(fd);
530  continue;
531  }
532 
533  if (addr->ai_family == AF_UNIX)
534  {
535  if (Setup_AF_UNIX(service) != STATUS_OK)
536  {
537  closesocket(fd);
538  break;
539  }
540  }
541 
542  /*
543  * Select appropriate accept-queue length limit. It seems reasonable
544  * to use a value similar to the maximum number of child processes
545  * that the postmaster will permit.
546  */
547  maxconn = MaxConnections * 2;
548 
549  err = listen(fd, maxconn);
550  if (err < 0)
551  {
552  ereport(LOG,
554  /* translator: first %s is IPv4, IPv6, or Unix */
555  errmsg("could not listen on %s address \"%s\": %m",
556  familyDesc, addrDesc)));
557  closesocket(fd);
558  continue;
559  }
560 
561  if (addr->ai_family == AF_UNIX)
562  ereport(LOG,
563  (errmsg("listening on Unix socket \"%s\"",
564  addrDesc)));
565  else
566  ereport(LOG,
567  /* translator: first %s is IPv4 or IPv6 */
568  (errmsg("listening on %s address \"%s\", port %d",
569  familyDesc, addrDesc, (int) portNumber)));
570 
572  (*NumListenSockets)++;
573  added++;
574  }
575 
576  pg_freeaddrinfo_all(hint.ai_family, addrs);
577 
578  if (!added)
579  return STATUS_ERROR;
580 
581  return STATUS_OK;
582 }
583 
584 
585 /*
586  * Lock_AF_UNIX -- configure unix socket file path
587  */
588 static int
589 Lock_AF_UNIX(const char *unixSocketDir, const char *unixSocketPath)
590 {
591  /* no lock file for abstract sockets */
592  if (unixSocketPath[0] == '@')
593  return STATUS_OK;
594 
595  /*
596  * Grab an interlock file associated with the socket file.
597  *
598  * Note: there are two reasons for using a socket lock file, rather than
599  * trying to interlock directly on the socket itself. First, it's a lot
600  * more portable, and second, it lets us remove any pre-existing socket
601  * file without race conditions.
602  */
603  CreateSocketLockFile(unixSocketPath, true, unixSocketDir);
604 
605  /*
606  * Once we have the interlock, we can safely delete any pre-existing
607  * socket file to avoid failure at bind() time.
608  */
609  (void) unlink(unixSocketPath);
610 
611  /*
612  * Remember socket file pathnames for later maintenance.
613  */
614  sock_paths = lappend(sock_paths, pstrdup(unixSocketPath));
615 
616  return STATUS_OK;
617 }
618 
619 
620 /*
621  * Setup_AF_UNIX -- configure unix socket permissions
622  */
623 static int
624 Setup_AF_UNIX(const char *sock_path)
625 {
626  /* no file system permissions for abstract sockets */
627  if (sock_path[0] == '@')
628  return STATUS_OK;
629 
630  /*
631  * Fix socket ownership/permission if requested. Note we must do this
632  * before we listen() to avoid a window where unwanted connections could
633  * get accepted.
634  */
636  if (Unix_socket_group[0] != '\0')
637  {
638 #ifdef WIN32
639  elog(WARNING, "configuration item unix_socket_group is not supported on this platform");
640 #else
641  char *endptr;
642  unsigned long val;
643  gid_t gid;
644 
645  val = strtoul(Unix_socket_group, &endptr, 10);
646  if (*endptr == '\0')
647  { /* numeric group id */
648  gid = val;
649  }
650  else
651  { /* convert group name to id */
652  struct group *gr;
653 
654  gr = getgrnam(Unix_socket_group);
655  if (!gr)
656  {
657  ereport(LOG,
658  (errmsg("group \"%s\" does not exist",
660  return STATUS_ERROR;
661  }
662  gid = gr->gr_gid;
663  }
664  if (chown(sock_path, -1, gid) == -1)
665  {
666  ereport(LOG,
668  errmsg("could not set group of file \"%s\": %m",
669  sock_path)));
670  return STATUS_ERROR;
671  }
672 #endif
673  }
674 
675  if (chmod(sock_path, Unix_socket_permissions) == -1)
676  {
677  ereport(LOG,
679  errmsg("could not set permissions of file \"%s\": %m",
680  sock_path)));
681  return STATUS_ERROR;
682  }
683  return STATUS_OK;
684 }
685 
686 
687 /*
688  * StreamConnection -- create a new connection with client using
689  * server port. Set port->sock to the FD of the new connection.
690  *
691  * ASSUME: that this doesn't need to be non-blocking because
692  * the Postmaster waits for the socket to be ready to accept().
693  *
694  * RETURNS: STATUS_OK or STATUS_ERROR
695  */
696 int
698 {
699  /* accept connection and fill in the client (remote) address */
700  port->raddr.salen = sizeof(port->raddr.addr);
701  if ((port->sock = accept(server_fd,
702  (struct sockaddr *) &port->raddr.addr,
703  &port->raddr.salen)) == PGINVALID_SOCKET)
704  {
705  ereport(LOG,
707  errmsg("could not accept new connection: %m")));
708 
709  /*
710  * If accept() fails then postmaster.c will still see the server
711  * socket as read-ready, and will immediately try again. To avoid
712  * uselessly sucking lots of CPU, delay a bit before trying again.
713  * (The most likely reason for failure is being out of kernel file
714  * table slots; we can do little except hope some will get freed up.)
715  */
716  pg_usleep(100000L); /* wait 0.1 sec */
717  return STATUS_ERROR;
718  }
719 
720  /* fill in the server (local) address */
721  port->laddr.salen = sizeof(port->laddr.addr);
722  if (getsockname(port->sock,
723  (struct sockaddr *) &port->laddr.addr,
724  &port->laddr.salen) < 0)
725  {
726  ereport(LOG,
727  (errmsg("%s() failed: %m", "getsockname")));
728  return STATUS_ERROR;
729  }
730 
731  /* select NODELAY and KEEPALIVE options if it's a TCP connection */
732  if (port->laddr.addr.ss_family != AF_UNIX)
733  {
734  int on;
735 #ifdef WIN32
736  int oldopt;
737  int optlen;
738  int newopt;
739 #endif
740 
741 #ifdef TCP_NODELAY
742  on = 1;
743  if (setsockopt(port->sock, IPPROTO_TCP, TCP_NODELAY,
744  (char *) &on, sizeof(on)) < 0)
745  {
746  ereport(LOG,
747  (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_NODELAY")));
748  return STATUS_ERROR;
749  }
750 #endif
751  on = 1;
752  if (setsockopt(port->sock, SOL_SOCKET, SO_KEEPALIVE,
753  (char *) &on, sizeof(on)) < 0)
754  {
755  ereport(LOG,
756  (errmsg("%s(%s) failed: %m", "setsockopt", "SO_KEEPALIVE")));
757  return STATUS_ERROR;
758  }
759 
760 #ifdef WIN32
761 
762  /*
763  * This is a Win32 socket optimization. The OS send buffer should be
764  * large enough to send the whole Postgres send buffer in one go, or
765  * performance suffers. The Postgres send buffer can be enlarged if a
766  * very large message needs to be sent, but we won't attempt to
767  * enlarge the OS buffer if that happens, so somewhat arbitrarily
768  * ensure that the OS buffer is at least PQ_SEND_BUFFER_SIZE * 4.
769  * (That's 32kB with the current default).
770  *
771  * The default OS buffer size used to be 8kB in earlier Windows
772  * versions, but was raised to 64kB in Windows 2012. So it shouldn't
773  * be necessary to change it in later versions anymore. Changing it
774  * unnecessarily can even reduce performance, because setting
775  * SO_SNDBUF in the application disables the "dynamic send buffering"
776  * feature that was introduced in Windows 7. So before fiddling with
777  * SO_SNDBUF, check if the current buffer size is already large enough
778  * and only increase it if necessary.
779  *
780  * See https://support.microsoft.com/kb/823764/EN-US/ and
781  * https://msdn.microsoft.com/en-us/library/bb736549%28v=vs.85%29.aspx
782  */
783  optlen = sizeof(oldopt);
784  if (getsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &oldopt,
785  &optlen) < 0)
786  {
787  ereport(LOG,
788  (errmsg("%s(%s) failed: %m", "getsockopt", "SO_SNDBUF")));
789  return STATUS_ERROR;
790  }
791  newopt = PQ_SEND_BUFFER_SIZE * 4;
792  if (oldopt < newopt)
793  {
794  if (setsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &newopt,
795  sizeof(newopt)) < 0)
796  {
797  ereport(LOG,
798  (errmsg("%s(%s) failed: %m", "setsockopt", "SO_SNDBUF")));
799  return STATUS_ERROR;
800  }
801  }
802 #endif
803 
804  /*
805  * Also apply the current keepalive parameters. If we fail to set a
806  * parameter, don't error out, because these aren't universally
807  * supported. (Note: you might think we need to reset the GUC
808  * variables to 0 in such a case, but it's not necessary because the
809  * show hooks for these variables report the truth anyway.)
810  */
815  }
816 
817  return STATUS_OK;
818 }
819 
820 /*
821  * StreamClose -- close a client/backend connection
822  *
823  * NOTE: this is NOT used to terminate a session; it is just used to release
824  * the file descriptor in a process that should no longer have the socket
825  * open. (For example, the postmaster calls this after passing ownership
826  * of the connection to a child process.) It is expected that someone else
827  * still has the socket open. So, we only want to close the descriptor,
828  * we do NOT want to send anything to the far end.
829  */
830 void
832 {
833  if (closesocket(sock) != 0)
834  elog(LOG, "could not close client or listen socket: %m");
835 }
836 
837 /*
838  * TouchSocketFiles -- mark socket files as recently accessed
839  *
840  * This routine should be called every so often to ensure that the socket
841  * files have a recent mod date (ordinary operations on sockets usually won't
842  * change the mod date). That saves them from being removed by
843  * overenthusiastic /tmp-directory-cleaner daemons. (Another reason we should
844  * never have put the socket file in /tmp...)
845  */
846 void
848 {
849  ListCell *l;
850 
851  /* Loop through all created sockets... */
852  foreach(l, sock_paths)
853  {
854  char *sock_path = (char *) lfirst(l);
855 
856  /* Ignore errors; there's no point in complaining */
857  (void) utime(sock_path, NULL);
858  }
859 }
860 
861 /*
862  * RemoveSocketFiles -- unlink socket files at postmaster shutdown
863  */
864 void
866 {
867  ListCell *l;
868 
869  /* Loop through all created sockets... */
870  foreach(l, sock_paths)
871  {
872  char *sock_path = (char *) lfirst(l);
873 
874  /* Ignore any error. */
875  (void) unlink(sock_path);
876  }
877  /* Since we're about to exit, no need to reclaim storage */
878  sock_paths = NIL;
879 }
880 
881 
882 /* --------------------------------
883  * Low-level I/O routines begin here.
884  *
885  * These routines communicate with a frontend client across a connection
886  * already established by the preceding routines.
887  * --------------------------------
888  */
889 
890 /* --------------------------------
891  * socket_set_nonblocking - set socket blocking/non-blocking
892  *
893  * Sets the socket non-blocking if nonblocking is true, or sets it
894  * blocking otherwise.
895  * --------------------------------
896  */
897 static void
898 socket_set_nonblocking(bool nonblocking)
899 {
900  if (MyProcPort == NULL)
901  ereport(ERROR,
902  (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
903  errmsg("there is no client connection")));
904 
905  MyProcPort->noblock = nonblocking;
906 }
907 
908 /* --------------------------------
909  * pq_recvbuf - load some bytes into the input buffer
910  *
911  * returns 0 if OK, EOF if trouble
912  * --------------------------------
913  */
914 static int
916 {
917  if (PqRecvPointer > 0)
918  {
920  {
921  /* still some unread data, left-justify it in the buffer */
925  PqRecvPointer = 0;
926  }
927  else
929  }
930 
931  /* Ensure that we're in blocking mode */
932  socket_set_nonblocking(false);
933 
934  /* Can fill buffer from PqRecvLength and upwards */
935  for (;;)
936  {
937  int r;
938 
941 
942  if (r < 0)
943  {
944  if (errno == EINTR)
945  continue; /* Ok if interrupted */
946 
947  /*
948  * Careful: an ereport() that tries to write to the client would
949  * cause recursion to here, leading to stack overflow and core
950  * dump! This message must go *only* to the postmaster log.
951  */
954  errmsg("could not receive data from client: %m")));
955  return EOF;
956  }
957  if (r == 0)
958  {
959  /*
960  * EOF detected. We used to write a log message here, but it's
961  * better to expect the ultimate caller to do that.
962  */
963  return EOF;
964  }
965  /* r contains number of bytes read, so just incr length */
966  PqRecvLength += r;
967  return 0;
968  }
969 }
970 
971 /* --------------------------------
972  * pq_getbyte - get a single byte from connection, or return EOF
973  * --------------------------------
974  */
975 int
977 {
979 
980  while (PqRecvPointer >= PqRecvLength)
981  {
982  if (pq_recvbuf()) /* If nothing in buffer, then recv some */
983  return EOF; /* Failed to recv data */
984  }
985  return (unsigned char) PqRecvBuffer[PqRecvPointer++];
986 }
987 
988 /* --------------------------------
989  * pq_peekbyte - peek at next byte from connection
990  *
991  * Same as pq_getbyte() except we don't advance the pointer.
992  * --------------------------------
993  */
994 int
996 {
998 
999  while (PqRecvPointer >= PqRecvLength)
1000  {
1001  if (pq_recvbuf()) /* If nothing in buffer, then recv some */
1002  return EOF; /* Failed to recv data */
1003  }
1004  return (unsigned char) PqRecvBuffer[PqRecvPointer];
1005 }
1006 
1007 /* --------------------------------
1008  * pq_getbyte_if_available - get a single byte from connection,
1009  * if available
1010  *
1011  * The received byte is stored in *c. Returns 1 if a byte was read,
1012  * 0 if no data was available, or EOF if trouble.
1013  * --------------------------------
1014  */
1015 int
1017 {
1018  int r;
1019 
1021 
1023  {
1025  return 1;
1026  }
1027 
1028  /* Put the socket into non-blocking mode */
1029  socket_set_nonblocking(true);
1030 
1031  r = secure_read(MyProcPort, c, 1);
1032  if (r < 0)
1033  {
1034  /*
1035  * Ok if no data available without blocking or interrupted (though
1036  * EINTR really shouldn't happen with a non-blocking socket). Report
1037  * other errors.
1038  */
1039  if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
1040  r = 0;
1041  else
1042  {
1043  /*
1044  * Careful: an ereport() that tries to write to the client would
1045  * cause recursion to here, leading to stack overflow and core
1046  * dump! This message must go *only* to the postmaster log.
1047  */
1050  errmsg("could not receive data from client: %m")));
1051  r = EOF;
1052  }
1053  }
1054  else if (r == 0)
1055  {
1056  /* EOF detected */
1057  r = EOF;
1058  }
1059 
1060  return r;
1061 }
1062 
1063 /* --------------------------------
1064  * pq_getbytes - get a known number of bytes from connection
1065  *
1066  * returns 0 if OK, EOF if trouble
1067  * --------------------------------
1068  */
1069 int
1070 pq_getbytes(char *s, size_t len)
1071 {
1072  size_t amount;
1073 
1075 
1076  while (len > 0)
1077  {
1078  while (PqRecvPointer >= PqRecvLength)
1079  {
1080  if (pq_recvbuf()) /* If nothing in buffer, then recv some */
1081  return EOF; /* Failed to recv data */
1082  }
1083  amount = PqRecvLength - PqRecvPointer;
1084  if (amount > len)
1085  amount = len;
1086  memcpy(s, PqRecvBuffer + PqRecvPointer, amount);
1087  PqRecvPointer += amount;
1088  s += amount;
1089  len -= amount;
1090  }
1091  return 0;
1092 }
1093 
1094 /* --------------------------------
1095  * pq_discardbytes - throw away a known number of bytes
1096  *
1097  * same as pq_getbytes except we do not copy the data to anyplace.
1098  * this is used for resynchronizing after read errors.
1099  *
1100  * returns 0 if OK, EOF if trouble
1101  * --------------------------------
1102  */
1103 static int
1105 {
1106  size_t amount;
1107 
1109 
1110  while (len > 0)
1111  {
1112  while (PqRecvPointer >= PqRecvLength)
1113  {
1114  if (pq_recvbuf()) /* If nothing in buffer, then recv some */
1115  return EOF; /* Failed to recv data */
1116  }
1117  amount = PqRecvLength - PqRecvPointer;
1118  if (amount > len)
1119  amount = len;
1120  PqRecvPointer += amount;
1121  len -= amount;
1122  }
1123  return 0;
1124 }
1125 
1126 /* --------------------------------
1127  * pq_buffer_has_data - is any buffered data available to read?
1128  *
1129  * This will *not* attempt to read more data.
1130  * --------------------------------
1131  */
1132 bool
1134 {
1135  return (PqRecvPointer < PqRecvLength);
1136 }
1137 
1138 
1139 /* --------------------------------
1140  * pq_startmsgread - begin reading a message from the client.
1141  *
1142  * This must be called before any of the pq_get* functions.
1143  * --------------------------------
1144  */
1145 void
1147 {
1148  /*
1149  * There shouldn't be a read active already, but let's check just to be
1150  * sure.
1151  */
1152  if (PqCommReadingMsg)
1153  ereport(FATAL,
1154  (errcode(ERRCODE_PROTOCOL_VIOLATION),
1155  errmsg("terminating connection because protocol synchronization was lost")));
1156 
1157  PqCommReadingMsg = true;
1158 }
1159 
1160 
1161 /* --------------------------------
1162  * pq_endmsgread - finish reading message.
1163  *
1164  * This must be called after reading a message with pq_getbytes()
1165  * and friends, to indicate that we have read the whole message.
1166  * pq_getmessage() does this implicitly.
1167  * --------------------------------
1168  */
1169 void
1171 {
1173 
1174  PqCommReadingMsg = false;
1175 }
1176 
1177 /* --------------------------------
1178  * pq_is_reading_msg - are we currently reading a message?
1179  *
1180  * This is used in error recovery at the outer idle loop to detect if we have
1181  * lost protocol sync, and need to terminate the connection. pq_startmsgread()
1182  * will check for that too, but it's nicer to detect it earlier.
1183  * --------------------------------
1184  */
1185 bool
1187 {
1188  return PqCommReadingMsg;
1189 }
1190 
1191 /* --------------------------------
1192  * pq_getmessage - get a message with length word from connection
1193  *
1194  * The return value is placed in an expansible StringInfo, which has
1195  * already been initialized by the caller.
1196  * Only the message body is placed in the StringInfo; the length word
1197  * is removed. Also, s->cursor is initialized to zero for convenience
1198  * in scanning the message contents.
1199  *
1200  * maxlen is the upper limit on the length of the
1201  * message we are willing to accept. We abort the connection (by
1202  * returning EOF) if client tries to send more than that.
1203  *
1204  * returns 0 if OK, EOF if trouble
1205  * --------------------------------
1206  */
1207 int
1209 {
1210  int32 len;
1211 
1213 
1214  resetStringInfo(s);
1215 
1216  /* Read message length word */
1217  if (pq_getbytes((char *) &len, 4) == EOF)
1218  {
1220  (errcode(ERRCODE_PROTOCOL_VIOLATION),
1221  errmsg("unexpected EOF within message length word")));
1222  return EOF;
1223  }
1224 
1225  len = pg_ntoh32(len);
1226 
1227  if (len < 4 || len > maxlen)
1228  {
1230  (errcode(ERRCODE_PROTOCOL_VIOLATION),
1231  errmsg("invalid message length")));
1232  return EOF;
1233  }
1234 
1235  len -= 4; /* discount length itself */
1236 
1237  if (len > 0)
1238  {
1239  /*
1240  * Allocate space for message. If we run out of room (ridiculously
1241  * large message), we will elog(ERROR), but we want to discard the
1242  * message body so as not to lose communication sync.
1243  */
1244  PG_TRY();
1245  {
1246  enlargeStringInfo(s, len);
1247  }
1248  PG_CATCH();
1249  {
1250  if (pq_discardbytes(len) == EOF)
1252  (errcode(ERRCODE_PROTOCOL_VIOLATION),
1253  errmsg("incomplete message from client")));
1254 
1255  /* we discarded the rest of the message so we're back in sync. */
1256  PqCommReadingMsg = false;
1257  PG_RE_THROW();
1258  }
1259  PG_END_TRY();
1260 
1261  /* And grab the message */
1262  if (pq_getbytes(s->data, len) == EOF)
1263  {
1265  (errcode(ERRCODE_PROTOCOL_VIOLATION),
1266  errmsg("incomplete message from client")));
1267  return EOF;
1268  }
1269  s->len = len;
1270  /* Place a trailing null per StringInfo convention */
1271  s->data[len] = '\0';
1272  }
1273 
1274  /* finished reading the message. */
1275  PqCommReadingMsg = false;
1276 
1277  return 0;
1278 }
1279 
1280 
1281 static int
1282 internal_putbytes(const char *s, size_t len)
1283 {
1284  size_t amount;
1285 
1286  while (len > 0)
1287  {
1288  /* If buffer is full, then flush it out */
1290  {
1291  socket_set_nonblocking(false);
1292  if (internal_flush())
1293  return EOF;
1294  }
1295  amount = PqSendBufferSize - PqSendPointer;
1296  if (amount > len)
1297  amount = len;
1298  memcpy(PqSendBuffer + PqSendPointer, s, amount);
1299  PqSendPointer += amount;
1300  s += amount;
1301  len -= amount;
1302  }
1303  return 0;
1304 }
1305 
1306 /* --------------------------------
1307  * socket_flush - flush pending output
1308  *
1309  * returns 0 if OK, EOF if trouble
1310  * --------------------------------
1311  */
1312 static int
1314 {
1315  int res;
1316 
1317  /* No-op if reentrant call */
1318  if (PqCommBusy)
1319  return 0;
1320  PqCommBusy = true;
1321  socket_set_nonblocking(false);
1322  res = internal_flush();
1323  PqCommBusy = false;
1324  return res;
1325 }
1326 
1327 /* --------------------------------
1328  * internal_flush - flush pending output
1329  *
1330  * Returns 0 if OK (meaning everything was sent, or operation would block
1331  * and the socket is in non-blocking mode), or EOF if trouble.
1332  * --------------------------------
1333  */
1334 static int
1336 {
1337  static int last_reported_send_errno = 0;
1338 
1339  char *bufptr = PqSendBuffer + PqSendStart;
1340  char *bufend = PqSendBuffer + PqSendPointer;
1341 
1342  while (bufptr < bufend)
1343  {
1344  int r;
1345 
1346  r = secure_write(MyProcPort, bufptr, bufend - bufptr);
1347 
1348  if (r <= 0)
1349  {
1350  if (errno == EINTR)
1351  continue; /* Ok if we were interrupted */
1352 
1353  /*
1354  * Ok if no data writable without blocking, and the socket is in
1355  * non-blocking mode.
1356  */
1357  if (errno == EAGAIN ||
1358  errno == EWOULDBLOCK)
1359  {
1360  return 0;
1361  }
1362 
1363  /*
1364  * Careful: an ereport() that tries to write to the client would
1365  * cause recursion to here, leading to stack overflow and core
1366  * dump! This message must go *only* to the postmaster log.
1367  *
1368  * If a client disconnects while we're in the midst of output, we
1369  * might write quite a bit of data before we get to a safe query
1370  * abort point. So, suppress duplicate log messages.
1371  */
1372  if (errno != last_reported_send_errno)
1373  {
1374  last_reported_send_errno = errno;
1377  errmsg("could not send data to client: %m")));
1378  }
1379 
1380  /*
1381  * We drop the buffered data anyway so that processing can
1382  * continue, even though we'll probably quit soon. We also set a
1383  * flag that'll cause the next CHECK_FOR_INTERRUPTS to terminate
1384  * the connection.
1385  */
1386  PqSendStart = PqSendPointer = 0;
1388  InterruptPending = 1;
1389  return EOF;
1390  }
1391 
1392  last_reported_send_errno = 0; /* reset after any successful send */
1393  bufptr += r;
1394  PqSendStart += r;
1395  }
1396 
1397  PqSendStart = PqSendPointer = 0;
1398  return 0;
1399 }
1400 
1401 /* --------------------------------
1402  * pq_flush_if_writable - flush pending output if writable without blocking
1403  *
1404  * Returns 0 if OK, or EOF if trouble.
1405  * --------------------------------
1406  */
1407 static int
1409 {
1410  int res;
1411 
1412  /* Quick exit if nothing to do */
1413  if (PqSendPointer == PqSendStart)
1414  return 0;
1415 
1416  /* No-op if reentrant call */
1417  if (PqCommBusy)
1418  return 0;
1419 
1420  /* Temporarily put the socket into non-blocking mode */
1421  socket_set_nonblocking(true);
1422 
1423  PqCommBusy = true;
1424  res = internal_flush();
1425  PqCommBusy = false;
1426  return res;
1427 }
1428 
1429 /* --------------------------------
1430  * socket_is_send_pending - is there any pending data in the output buffer?
1431  * --------------------------------
1432  */
1433 static bool
1435 {
1436  return (PqSendStart < PqSendPointer);
1437 }
1438 
1439 /* --------------------------------
1440  * Message-level I/O routines begin here.
1441  * --------------------------------
1442  */
1443 
1444 
1445 /* --------------------------------
1446  * socket_putmessage - send a normal message (suppressed in COPY OUT mode)
1447  *
1448  * msgtype is a message type code to place before the message body.
1449  *
1450  * len is the length of the message body data at *s. A message length
1451  * word (equal to len+4 because it counts itself too) is inserted by this
1452  * routine.
1453  *
1454  * We suppress messages generated while pqcomm.c is busy. This
1455  * avoids any possibility of messages being inserted within other
1456  * messages. The only known trouble case arises if SIGQUIT occurs
1457  * during a pqcomm.c routine --- quickdie() will try to send a warning
1458  * message, and the most reasonable approach seems to be to drop it.
1459  *
1460  * returns 0 if OK, EOF if trouble
1461  * --------------------------------
1462  */
1463 static int
1464 socket_putmessage(char msgtype, const char *s, size_t len)
1465 {
1466  uint32 n32;
1467 
1468  Assert(msgtype != 0);
1469 
1470  if (PqCommBusy)
1471  return 0;
1472  PqCommBusy = true;
1473  if (internal_putbytes(&msgtype, 1))
1474  goto fail;
1475 
1476  n32 = pg_hton32((uint32) (len + 4));
1477  if (internal_putbytes((char *) &n32, 4))
1478  goto fail;
1479 
1480  if (internal_putbytes(s, len))
1481  goto fail;
1482  PqCommBusy = false;
1483  return 0;
1484 
1485 fail:
1486  PqCommBusy = false;
1487  return EOF;
1488 }
1489 
1490 /* --------------------------------
1491  * pq_putmessage_noblock - like pq_putmessage, but never blocks
1492  *
1493  * If the output buffer is too small to hold the message, the buffer
1494  * is enlarged.
1495  */
1496 static void
1497 socket_putmessage_noblock(char msgtype, const char *s, size_t len)
1498 {
1500  int required;
1501 
1502  /*
1503  * Ensure we have enough space in the output buffer for the message header
1504  * as well as the message itself.
1505  */
1506  required = PqSendPointer + 1 + 4 + len;
1507  if (required > PqSendBufferSize)
1508  {
1511  }
1512  res = pq_putmessage(msgtype, s, len);
1513  Assert(res == 0); /* should not fail when the message fits in
1514  * buffer */
1515 }
1516 
1517 /* --------------------------------
1518  * pq_putmessage_v2 - send a message in protocol version 2
1519  *
1520  * msgtype is a message type code to place before the message body.
1521  *
1522  * We no longer support protocol version 2, but we have kept this
1523  * function so that if a client tries to connect with protocol version 2,
1524  * as a courtesy we can still send the "unsupported protocol version"
1525  * error to the client in the old format.
1526  *
1527  * Like in pq_putmessage(), we suppress messages generated while
1528  * pqcomm.c is busy.
1529  *
1530  * returns 0 if OK, EOF if trouble
1531  * --------------------------------
1532  */
1533 int
1534 pq_putmessage_v2(char msgtype, const char *s, size_t len)
1535 {
1536  Assert(msgtype != 0);
1537 
1538  if (PqCommBusy)
1539  return 0;
1540  PqCommBusy = true;
1541  if (internal_putbytes(&msgtype, 1))
1542  goto fail;
1543 
1544  if (internal_putbytes(s, len))
1545  goto fail;
1546  PqCommBusy = false;
1547  return 0;
1548 
1549 fail:
1550  PqCommBusy = false;
1551  return EOF;
1552 }
1553 
1554 /*
1555  * Support for TCP Keepalive parameters
1556  */
1557 
1558 /*
1559  * On Windows, we need to set both idle and interval at the same time.
1560  * We also cannot reset them to the default (setting to zero will
1561  * actually set them to zero, not default), therefore we fallback to
1562  * the out-of-the-box default instead.
1563  */
1564 #if defined(WIN32) && defined(SIO_KEEPALIVE_VALS)
1565 static int
1566 pq_setkeepaliveswin32(Port *port, int idle, int interval)
1567 {
1568  struct tcp_keepalive ka;
1569  DWORD retsize;
1570 
1571  if (idle <= 0)
1572  idle = 2 * 60 * 60; /* default = 2 hours */
1573  if (interval <= 0)
1574  interval = 1; /* default = 1 second */
1575 
1576  ka.onoff = 1;
1577  ka.keepalivetime = idle * 1000;
1578  ka.keepaliveinterval = interval * 1000;
1579 
1580  if (WSAIoctl(port->sock,
1581  SIO_KEEPALIVE_VALS,
1582  (LPVOID) &ka,
1583  sizeof(ka),
1584  NULL,
1585  0,
1586  &retsize,
1587  NULL,
1588  NULL)
1589  != 0)
1590  {
1591  ereport(LOG,
1592  (errmsg("%s(%s) failed: error code %d",
1593  "WSAIoctl", "SIO_KEEPALIVE_VALS", WSAGetLastError())));
1594  return STATUS_ERROR;
1595  }
1596  if (port->keepalives_idle != idle)
1597  port->keepalives_idle = idle;
1598  if (port->keepalives_interval != interval)
1599  port->keepalives_interval = interval;
1600  return STATUS_OK;
1601 }
1602 #endif
1603 
1604 int
1606 {
1607 #if defined(PG_TCP_KEEPALIVE_IDLE) || defined(SIO_KEEPALIVE_VALS)
1608  if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1609  return 0;
1610 
1611  if (port->keepalives_idle != 0)
1612  return port->keepalives_idle;
1613 
1614  if (port->default_keepalives_idle == 0)
1615  {
1616 #ifndef WIN32
1617  socklen_t size = sizeof(port->default_keepalives_idle);
1618 
1619  if (getsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
1620  (char *) &port->default_keepalives_idle,
1621  &size) < 0)
1622  {
1623  ereport(LOG,
1624  (errmsg("%s(%s) failed: %m", "getsockopt", PG_TCP_KEEPALIVE_IDLE_STR)));
1625  port->default_keepalives_idle = -1; /* don't know */
1626  }
1627 #else /* WIN32 */
1628  /* We can't get the defaults on Windows, so return "don't know" */
1629  port->default_keepalives_idle = -1;
1630 #endif /* WIN32 */
1631  }
1632 
1633  return port->default_keepalives_idle;
1634 #else
1635  return 0;
1636 #endif
1637 }
1638 
1639 int
1641 {
1642  if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1643  return STATUS_OK;
1644 
1645 /* check SIO_KEEPALIVE_VALS here, not just WIN32, as some toolchains lack it */
1646 #if defined(PG_TCP_KEEPALIVE_IDLE) || defined(SIO_KEEPALIVE_VALS)
1647  if (idle == port->keepalives_idle)
1648  return STATUS_OK;
1649 
1650 #ifndef WIN32
1651  if (port->default_keepalives_idle <= 0)
1652  {
1653  if (pq_getkeepalivesidle(port) < 0)
1654  {
1655  if (idle == 0)
1656  return STATUS_OK; /* default is set but unknown */
1657  else
1658  return STATUS_ERROR;
1659  }
1660  }
1661 
1662  if (idle == 0)
1663  idle = port->default_keepalives_idle;
1664 
1665  if (setsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
1666  (char *) &idle, sizeof(idle)) < 0)
1667  {
1668  ereport(LOG,
1669  (errmsg("%s(%s) failed: %m", "setsockopt", PG_TCP_KEEPALIVE_IDLE_STR)));
1670  return STATUS_ERROR;
1671  }
1672 
1673  port->keepalives_idle = idle;
1674 #else /* WIN32 */
1675  return pq_setkeepaliveswin32(port, idle, port->keepalives_interval);
1676 #endif
1677 #else
1678  if (idle != 0)
1679  {
1680  ereport(LOG,
1681  (errmsg("setting the keepalive idle time is not supported")));
1682  return STATUS_ERROR;
1683  }
1684 #endif
1685 
1686  return STATUS_OK;
1687 }
1688 
1689 int
1691 {
1692 #if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
1693  if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1694  return 0;
1695 
1696  if (port->keepalives_interval != 0)
1697  return port->keepalives_interval;
1698 
1699  if (port->default_keepalives_interval == 0)
1700  {
1701 #ifndef WIN32
1702  socklen_t size = sizeof(port->default_keepalives_interval);
1703 
1704  if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
1705  (char *) &port->default_keepalives_interval,
1706  &size) < 0)
1707  {
1708  ereport(LOG,
1709  (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_KEEPINTVL")));
1710  port->default_keepalives_interval = -1; /* don't know */
1711  }
1712 #else
1713  /* We can't get the defaults on Windows, so return "don't know" */
1714  port->default_keepalives_interval = -1;
1715 #endif /* WIN32 */
1716  }
1717 
1718  return port->default_keepalives_interval;
1719 #else
1720  return 0;
1721 #endif
1722 }
1723 
1724 int
1726 {
1727  if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1728  return STATUS_OK;
1729 
1730 #if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
1731  if (interval == port->keepalives_interval)
1732  return STATUS_OK;
1733 
1734 #ifndef WIN32
1735  if (port->default_keepalives_interval <= 0)
1736  {
1737  if (pq_getkeepalivesinterval(port) < 0)
1738  {
1739  if (interval == 0)
1740  return STATUS_OK; /* default is set but unknown */
1741  else
1742  return STATUS_ERROR;
1743  }
1744  }
1745 
1746  if (interval == 0)
1747  interval = port->default_keepalives_interval;
1748 
1749  if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
1750  (char *) &interval, sizeof(interval)) < 0)
1751  {
1752  ereport(LOG,
1753  (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_KEEPINTVL")));
1754  return STATUS_ERROR;
1755  }
1756 
1757  port->keepalives_interval = interval;
1758 #else /* WIN32 */
1759  return pq_setkeepaliveswin32(port, port->keepalives_idle, interval);
1760 #endif
1761 #else
1762  if (interval != 0)
1763  {
1764  ereport(LOG,
1765  (errmsg("%s(%s) not supported", "setsockopt", "TCP_KEEPINTVL")));
1766  return STATUS_ERROR;
1767  }
1768 #endif
1769 
1770  return STATUS_OK;
1771 }
1772 
1773 int
1775 {
1776 #ifdef TCP_KEEPCNT
1777  if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1778  return 0;
1779 
1780  if (port->keepalives_count != 0)
1781  return port->keepalives_count;
1782 
1783  if (port->default_keepalives_count == 0)
1784  {
1785  socklen_t size = sizeof(port->default_keepalives_count);
1786 
1787  if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
1788  (char *) &port->default_keepalives_count,
1789  &size) < 0)
1790  {
1791  ereport(LOG,
1792  (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_KEEPCNT")));
1793  port->default_keepalives_count = -1; /* don't know */
1794  }
1795  }
1796 
1797  return port->default_keepalives_count;
1798 #else
1799  return 0;
1800 #endif
1801 }
1802 
1803 int
1805 {
1806  if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1807  return STATUS_OK;
1808 
1809 #ifdef TCP_KEEPCNT
1810  if (count == port->keepalives_count)
1811  return STATUS_OK;
1812 
1813  if (port->default_keepalives_count <= 0)
1814  {
1815  if (pq_getkeepalivescount(port) < 0)
1816  {
1817  if (count == 0)
1818  return STATUS_OK; /* default is set but unknown */
1819  else
1820  return STATUS_ERROR;
1821  }
1822  }
1823 
1824  if (count == 0)
1825  count = port->default_keepalives_count;
1826 
1827  if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
1828  (char *) &count, sizeof(count)) < 0)
1829  {
1830  ereport(LOG,
1831  (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_KEEPCNT")));
1832  return STATUS_ERROR;
1833  }
1834 
1835  port->keepalives_count = count;
1836 #else
1837  if (count != 0)
1838  {
1839  ereport(LOG,
1840  (errmsg("%s(%s) not supported", "setsockopt", "TCP_KEEPCNT")));
1841  return STATUS_ERROR;
1842  }
1843 #endif
1844 
1845  return STATUS_OK;
1846 }
1847 
1848 int
1850 {
1851 #ifdef TCP_USER_TIMEOUT
1852  if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1853  return 0;
1854 
1855  if (port->tcp_user_timeout != 0)
1856  return port->tcp_user_timeout;
1857 
1858  if (port->default_tcp_user_timeout == 0)
1859  {
1860  socklen_t size = sizeof(port->default_tcp_user_timeout);
1861 
1862  if (getsockopt(port->sock, IPPROTO_TCP, TCP_USER_TIMEOUT,
1863  (char *) &port->default_tcp_user_timeout,
1864  &size) < 0)
1865  {
1866  ereport(LOG,
1867  (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_USER_TIMEOUT")));
1868  port->default_tcp_user_timeout = -1; /* don't know */
1869  }
1870  }
1871 
1872  return port->default_tcp_user_timeout;
1873 #else
1874  return 0;
1875 #endif
1876 }
1877 
1878 int
1880 {
1881  if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1882  return STATUS_OK;
1883 
1884 #ifdef TCP_USER_TIMEOUT
1885  if (timeout == port->tcp_user_timeout)
1886  return STATUS_OK;
1887 
1888  if (port->default_tcp_user_timeout <= 0)
1889  {
1890  if (pq_gettcpusertimeout(port) < 0)
1891  {
1892  if (timeout == 0)
1893  return STATUS_OK; /* default is set but unknown */
1894  else
1895  return STATUS_ERROR;
1896  }
1897  }
1898 
1899  if (timeout == 0)
1900  timeout = port->default_tcp_user_timeout;
1901 
1902  if (setsockopt(port->sock, IPPROTO_TCP, TCP_USER_TIMEOUT,
1903  (char *) &timeout, sizeof(timeout)) < 0)
1904  {
1905  ereport(LOG,
1906  (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_USER_TIMEOUT")));
1907  return STATUS_ERROR;
1908  }
1909 
1910  port->tcp_user_timeout = timeout;
1911 #else
1912  if (timeout != 0)
1913  {
1914  ereport(LOG,
1915  (errmsg("%s(%s) not supported", "setsockopt", "TCP_USER_TIMEOUT")));
1916  return STATUS_ERROR;
1917  }
1918 #endif
1919 
1920  return STATUS_OK;
1921 }
1922 
1923 /*
1924  * GUC assign_hook for tcp_keepalives_idle
1925  */
1926 void
1928 {
1929  /*
1930  * The kernel API provides no way to test a value without setting it; and
1931  * once we set it we might fail to unset it. So there seems little point
1932  * in fully implementing the check-then-assign GUC API for these
1933  * variables. Instead we just do the assignment on demand.
1934  * pq_setkeepalivesidle reports any problems via ereport(LOG).
1935  *
1936  * This approach means that the GUC value might have little to do with the
1937  * actual kernel value, so we use a show_hook that retrieves the kernel
1938  * value rather than trusting GUC's copy.
1939  */
1941 }
1942 
1943 /*
1944  * GUC show_hook for tcp_keepalives_idle
1945  */
1946 const char *
1948 {
1949  /* See comments in assign_tcp_keepalives_idle */
1950  static char nbuf[16];
1951 
1952  snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
1953  return nbuf;
1954 }
1955 
1956 /*
1957  * GUC assign_hook for tcp_keepalives_interval
1958  */
1959 void
1961 {
1962  /* See comments in assign_tcp_keepalives_idle */
1964 }
1965 
1966 /*
1967  * GUC show_hook for tcp_keepalives_interval
1968  */
1969 const char *
1971 {
1972  /* See comments in assign_tcp_keepalives_idle */
1973  static char nbuf[16];
1974 
1975  snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
1976  return nbuf;
1977 }
1978 
1979 /*
1980  * GUC assign_hook for tcp_keepalives_count
1981  */
1982 void
1984 {
1985  /* See comments in assign_tcp_keepalives_idle */
1987 }
1988 
1989 /*
1990  * GUC show_hook for tcp_keepalives_count
1991  */
1992 const char *
1994 {
1995  /* See comments in assign_tcp_keepalives_idle */
1996  static char nbuf[16];
1997 
1998  snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
1999  return nbuf;
2000 }
2001 
2002 /*
2003  * GUC assign_hook for tcp_user_timeout
2004  */
2005 void
2007 {
2008  /* See comments in assign_tcp_keepalives_idle */
2010 }
2011 
2012 /*
2013  * GUC show_hook for tcp_user_timeout
2014  */
2015 const char *
2017 {
2018  /* See comments in assign_tcp_keepalives_idle */
2019  static char nbuf[16];
2020 
2021  snprintf(nbuf, sizeof(nbuf), "%d", pq_gettcpusertimeout(MyProcPort));
2022  return nbuf;
2023 }
2024 
2025 /*
2026  * Check if the client is still connected.
2027  */
2028 bool
2030 {
2031  WaitEvent events[FeBeWaitSetNEvents];
2032  int rc;
2033 
2034  /*
2035  * It's OK to modify the socket event filter without restoring, because
2036  * all FeBeWaitSet socket wait sites do the same.
2037  */
2039 
2040 retry:
2041  rc = WaitEventSetWait(FeBeWaitSet, 0, events, lengthof(events), 0);
2042  for (int i = 0; i < rc; ++i)
2043  {
2044  if (events[i].events & WL_SOCKET_CLOSED)
2045  return false;
2046  if (events[i].events & WL_LATCH_SET)
2047  {
2048  /*
2049  * A latch event might be preventing other events from being
2050  * reported. Reset it and poll again. No need to restore it
2051  * because no code should expect latches to survive across
2052  * CHECK_FOR_INTERRUPTS().
2053  */
2055  goto retry;
2056  }
2057  }
2058 
2059  return true;
2060 }
ssize_t secure_write(Port *port, void *ptr, size_t len)
Definition: be-secure.c:258
void secure_close(Port *port)
Definition: be-secure.c:133
ssize_t secure_read(Port *port, void *ptr, size_t len)
Definition: be-secure.c:145
unsigned int uint32
Definition: c.h:495
#define STATUS_OK
Definition: c.h:1182
signed int int32
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#define PG_USED_FOR_ASSERTS_ONLY
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#define lengthof(array)
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#define MemSet(start, val, len)
Definition: c.h:1009
#define STATUS_ERROR
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int errcode_for_socket_access(void)
Definition: elog.c:952
int errcode_for_file_access(void)
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int errhint(const char *fmt,...)
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int errcode(int sqlerrcode)
Definition: elog.c:858
int errmsg(const char *fmt,...)
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#define _(x)
Definition: elog.c:91
#define LOG
Definition: elog.h:31
#define PG_RE_THROW()
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#define COMMERROR
Definition: elog.h:33
#define FATAL
Definition: elog.h:41
#define PG_TRY(...)
Definition: elog.h:370
#define WARNING
Definition: elog.h:36
#define PG_END_TRY(...)
Definition: elog.h:395
#define ERROR
Definition: elog.h:39
#define PG_CATCH(...)
Definition: elog.h:380
#define ereport(elevel,...)
Definition: elog.h:149
void err(int eval, const char *fmt,...)
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volatile sig_atomic_t InterruptPending
Definition: globals.c:30
int MaxConnections
Definition: globals.c:139
volatile sig_atomic_t ClientConnectionLost
Definition: globals.c:34
struct Port * MyProcPort
Definition: globals.c:47
struct Latch * MyLatch
Definition: globals.c:58
#define newval
int tcp_keepalives_idle
Definition: guc_tables.c:543
int tcp_keepalives_interval
Definition: guc_tables.c:544
int tcp_keepalives_count
Definition: guc_tables.c:545
int tcp_user_timeout
Definition: guc_tables.c:546
long val
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int pg_getnameinfo_all(const struct sockaddr_storage *addr, int salen, char *node, int nodelen, char *service, int servicelen, int flags)
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int pg_getaddrinfo_all(const char *hostname, const char *servname, const struct addrinfo *hintp, struct addrinfo **result)
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void on_proc_exit(pg_on_exit_callback function, Datum arg)
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int i
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void ModifyWaitEvent(WaitEventSet *set, int pos, uint32 events, Latch *latch)
Definition: latch.c:1050
WaitEventSet * CreateWaitEventSet(ResourceOwner resowner, int nevents)
Definition: latch.c:752
int AddWaitEventToSet(WaitEventSet *set, uint32 events, pgsocket fd, Latch *latch, void *user_data)
Definition: latch.c:964
int WaitEventSetWait(WaitEventSet *set, long timeout, WaitEvent *occurred_events, int nevents, uint32 wait_event_info)
Definition: latch.c:1425
void ResetLatch(Latch *latch)
Definition: latch.c:725
#define WL_SOCKET_CLOSED
Definition: latch.h:139
#define WL_LATCH_SET
Definition: latch.h:127
#define WL_POSTMASTER_DEATH
Definition: latch.h:131
#define WL_SOCKET_WRITEABLE
Definition: latch.h:129
#define pq_putmessage(msgtype, s, len)
Definition: libpq.h:49
#define FeBeWaitSetLatchPos
Definition: libpq.h:64
#define FeBeWaitSetNEvents
Definition: libpq.h:65
#define FeBeWaitSetSocketPos
Definition: libpq.h:63
Assert(fmt[strlen(fmt) - 1] !='\n')
List * lappend(List *list, void *datum)
Definition: list.c:338
char * pstrdup(const char *in)
Definition: mcxt.c:1644
MemoryContext TopMemoryContext
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void * repalloc(void *pointer, Size size)
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void * MemoryContextAlloc(MemoryContext context, Size size)
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void CreateSocketLockFile(const char *socketfile, bool amPostmaster, const char *socketDir)
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void * arg
#define pg_ntoh32(x)
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#define pg_hton32(x)
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#define MAXPGPATH
const void size_t len
#define lfirst(lc)
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#define NIL
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static int port
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bool pg_set_noblock(pgsocket sock)
Definition: noblock.c:25
int pgsocket
Definition: port.h:29
#define snprintf
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unsigned int socklen_t
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#define PGINVALID_SOCKET
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#define closesocket
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uintptr_t Datum
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static pgsocket * ListenSockets
Definition: postmaster.c:231
static int NumListenSockets
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static int PqRecvLength
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int pq_setkeepalivesinterval(int interval, Port *port)
Definition: pqcomm.c:1725
void assign_tcp_keepalives_count(int newval, void *extra)
Definition: pqcomm.c:1983
const PQcommMethods * PqCommMethods
Definition: pqcomm.c:162
static int pq_recvbuf(void)
Definition: pqcomm.c:915
static int PqSendStart
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int Unix_socket_permissions
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static int internal_flush(void)
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static void socket_set_nonblocking(bool nonblocking)
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int pq_peekbyte(void)
Definition: pqcomm.c:995
int pq_getbyte_if_available(unsigned char *c)
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static int socket_flush_if_writable(void)
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int pq_getkeepalivescount(Port *port)
Definition: pqcomm.c:1774
#define PQ_RECV_BUFFER_SIZE
Definition: pqcomm.c:120
int pq_getkeepalivesinterval(Port *port)
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static int PqSendPointer
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static int pq_discardbytes(size_t len)
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int pq_getmessage(StringInfo s, int maxlen)
Definition: pqcomm.c:1208
static const PQcommMethods PqCommSocketMethods
Definition: pqcomm.c:153
const char * show_tcp_keepalives_interval(void)
Definition: pqcomm.c:1970
int pq_getbytes(char *s, size_t len)
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static bool PqCommReadingMsg
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Definition: pqcomm.c:322
const char * show_tcp_user_timeout(void)
Definition: pqcomm.c:2016
#define PQ_SEND_BUFFER_SIZE
Definition: pqcomm.c:119
int pq_setkeepalivesidle(int idle, Port *port)
Definition: pqcomm.c:1640
static void socket_comm_reset(void)
Definition: pqcomm.c:235
WaitEventSet * FeBeWaitSet
Definition: pqcomm.c:164
static char * PqSendBuffer
Definition: pqcomm.c:122
static int Lock_AF_UNIX(const char *unixSocketDir, const char *unixSocketPath)
Definition: pqcomm.c:589
int pq_getkeepalivesidle(Port *port)
Definition: pqcomm.c:1605
void pq_endmsgread(void)
Definition: pqcomm.c:1170
static List * sock_paths
Definition: pqcomm.c:110
void TouchSocketFiles(void)
Definition: pqcomm.c:847
static bool PqCommBusy
Definition: pqcomm.c:134
int pq_getbyte(void)
Definition: pqcomm.c:976
static bool socket_is_send_pending(void)
Definition: pqcomm.c:1434
void assign_tcp_keepalives_idle(int newval, void *extra)
Definition: pqcomm.c:1927
static int socket_putmessage(char msgtype, const char *s, size_t len)
Definition: pqcomm.c:1464
static void socket_putmessage_noblock(char msgtype, const char *s, size_t len)
Definition: pqcomm.c:1497
bool pq_buffer_has_data(void)
Definition: pqcomm.c:1133
static char PqRecvBuffer[PQ_RECV_BUFFER_SIZE]
Definition: pqcomm.c:127
static int PqRecvPointer
Definition: pqcomm.c:128
void pq_init(void)
Definition: pqcomm.c:172
static void socket_close(int code, Datum arg)
Definition: pqcomm.c:250
void assign_tcp_user_timeout(int newval, void *extra)
Definition: pqcomm.c:2006
int pq_putmessage_v2(char msgtype, const char *s, size_t len)
Definition: pqcomm.c:1534
const char * show_tcp_keepalives_idle(void)
Definition: pqcomm.c:1947
static int Setup_AF_UNIX(const char *sock_path)
Definition: pqcomm.c:624
bool pq_is_reading_msg(void)
Definition: pqcomm.c:1186
void RemoveSocketFiles(void)
Definition: pqcomm.c:865
int pq_gettcpusertimeout(Port *port)
Definition: pqcomm.c:1849
bool pq_check_connection(void)
Definition: pqcomm.c:2029
static int PqSendBufferSize
Definition: pqcomm.c:123
const char * show_tcp_keepalives_count(void)
Definition: pqcomm.c:1993
void assign_tcp_keepalives_interval(int newval, void *extra)
Definition: pqcomm.c:1960
void pq_startmsgread(void)
Definition: pqcomm.c:1146
int pq_setkeepalivescount(int count, Port *port)
Definition: pqcomm.c:1804
int StreamConnection(pgsocket server_fd, Port *port)
Definition: pqcomm.c:697
static int internal_putbytes(const char *s, size_t len)
Definition: pqcomm.c:1282
#define UNIXSOCK_PATH(path, port, sockdir)
Definition: pqcomm.h:44
#define UNIXSOCK_PATH_BUFLEN
Definition: pqcomm.h:60
char * c
static int fd(const char *x, int i)
Definition: preproc-init.c:105
void pg_usleep(long microsec)
Definition: signal.c:53
void resetStringInfo(StringInfo str)
Definition: stringinfo.c:78
void enlargeStringInfo(StringInfo str, int needed)
Definition: stringinfo.c:289
Definition: pg_list.h:54
void(* comm_reset)(void)
Definition: libpq.h:35
Definition: libpq-be.h:147
void * gss
Definition: libpq-be.h:211
pgsocket sock
Definition: libpq-be.h:148
bool noblock
Definition: libpq-be.h:149
#define bind(s, addr, addrlen)
Definition: win32_port.h:491
#define EINTR
Definition: win32_port.h:374
#define EWOULDBLOCK
Definition: win32_port.h:380
#define EADDRINUSE
Definition: win32_port.h:400
int gid_t
Definition: win32_port.h:245
#define socket(af, type, protocol)
Definition: win32_port.h:490
#define accept(s, addr, addrlen)
Definition: win32_port.h:493
#define listen(s, backlog)
Definition: win32_port.h:492
#define EAGAIN
Definition: win32_port.h:372