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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) 1996-2024, 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 * ListenServerPort - Open postmaster's server port
33 * AcceptConnection - Accept new connection with client
34 * TouchSocketFiles - Protect socket files against /tmp cleaners
35 * pq_init - initialize libpq at backend startup
36 * socket_comm_reset - reset libpq during error recovery
37 * socket_close - shutdown libpq at backend exit
38 *
39 * low-level I/O:
40 * pq_getbytes - get a known number of bytes from connection
41 * pq_getmessage - get a message with length word from connection
42 * pq_getbyte - get next byte from connection
43 * pq_peekbyte - peek at next byte from connection
44 * pq_flush - flush pending output
45 * pq_flush_if_writable - flush pending output if writable without blocking
46 * pq_getbyte_if_available - get a byte if available without blocking
47 *
48 * message-level I/O
49 * pq_putmessage - send a normal message (suppressed in COPY OUT mode)
50 * pq_putmessage_noblock - buffer a normal message (suppressed in COPY OUT)
51 *
52 *------------------------
53 */
54#include "postgres.h"
55
56#ifdef HAVE_POLL_H
57#include <poll.h>
58#endif
59#include <signal.h>
60#include <fcntl.h>
61#include <grp.h>
62#include <unistd.h>
63#include <sys/file.h>
64#include <sys/socket.h>
65#include <sys/stat.h>
66#include <sys/time.h>
67#include <netdb.h>
68#include <netinet/in.h>
69#include <netinet/tcp.h>
70#include <utime.h>
71#ifdef WIN32
72#include <mstcpip.h>
73#endif
74
75#include "common/ip.h"
76#include "libpq/libpq.h"
77#include "miscadmin.h"
78#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) */
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
122static char *PqSendBuffer;
123static int PqSendBufferSize; /* Size send buffer */
124static size_t PqSendPointer; /* Next index to store a byte in PqSendBuffer */
125static size_t PqSendStart; /* Next index to send a byte in PqSendBuffer */
126
128static int PqRecvPointer; /* Next index to read a byte from PqRecvBuffer */
129static int PqRecvLength; /* End of data available in PqRecvBuffer */
130
131/*
132 * Message status
133 */
134static bool PqCommBusy; /* busy sending data to the client */
135static bool PqCommReadingMsg; /* in the middle of reading a message */
136
137
138/* Internal functions */
139static void socket_comm_reset(void);
140static void socket_close(int code, Datum arg);
141static void socket_set_nonblocking(bool nonblocking);
142static int socket_flush(void);
143static int socket_flush_if_writable(void);
144static bool socket_is_send_pending(void);
145static int socket_putmessage(char msgtype, const char *s, size_t len);
146static void socket_putmessage_noblock(char msgtype, const char *s, size_t len);
147static inline int internal_putbytes(const char *s, size_t len);
148static inline int internal_flush(void);
149static pg_noinline int internal_flush_buffer(const char *buf, size_t *start,
150 size_t *end);
151
152static int Lock_AF_UNIX(const char *unixSocketDir, const char *unixSocketPath);
153static int Setup_AF_UNIX(const char *sock_path);
154
157 .flush = socket_flush,
158 .flush_if_writable = socket_flush_if_writable,
159 .is_send_pending = socket_is_send_pending,
160 .putmessage = socket_putmessage,
161 .putmessage_noblock = socket_putmessage_noblock
162};
163
165
167
168
169/* --------------------------------
170 * pq_init - initialize libpq at backend startup
171 * --------------------------------
172 */
173Port *
175{
176 Port *port;
177 int socket_pos PG_USED_FOR_ASSERTS_ONLY;
178 int latch_pos PG_USED_FOR_ASSERTS_ONLY;
179
180 /* allocate the Port struct and copy the ClientSocket contents to it */
181 port = palloc0(sizeof(Port));
182 port->sock = client_sock->sock;
183 memcpy(&port->raddr.addr, &client_sock->raddr.addr, client_sock->raddr.salen);
184 port->raddr.salen = client_sock->raddr.salen;
185
186 /* fill in the server (local) address */
187 port->laddr.salen = sizeof(port->laddr.addr);
188 if (getsockname(port->sock,
189 (struct sockaddr *) &port->laddr.addr,
190 &port->laddr.salen) < 0)
191 {
193 (errmsg("%s() failed: %m", "getsockname")));
194 }
195
196 /* select NODELAY and KEEPALIVE options if it's a TCP connection */
197 if (port->laddr.addr.ss_family != AF_UNIX)
198 {
199 int on;
200#ifdef WIN32
201 int oldopt;
202 int optlen;
203 int newopt;
204#endif
205
206#ifdef TCP_NODELAY
207 on = 1;
208 if (setsockopt(port->sock, IPPROTO_TCP, TCP_NODELAY,
209 (char *) &on, sizeof(on)) < 0)
210 {
212 (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_NODELAY")));
213 }
214#endif
215 on = 1;
216 if (setsockopt(port->sock, SOL_SOCKET, SO_KEEPALIVE,
217 (char *) &on, sizeof(on)) < 0)
218 {
220 (errmsg("%s(%s) failed: %m", "setsockopt", "SO_KEEPALIVE")));
221 }
222
223#ifdef WIN32
224
225 /*
226 * This is a Win32 socket optimization. The OS send buffer should be
227 * large enough to send the whole Postgres send buffer in one go, or
228 * performance suffers. The Postgres send buffer can be enlarged if a
229 * very large message needs to be sent, but we won't attempt to
230 * enlarge the OS buffer if that happens, so somewhat arbitrarily
231 * ensure that the OS buffer is at least PQ_SEND_BUFFER_SIZE * 4.
232 * (That's 32kB with the current default).
233 *
234 * The default OS buffer size used to be 8kB in earlier Windows
235 * versions, but was raised to 64kB in Windows 2012. So it shouldn't
236 * be necessary to change it in later versions anymore. Changing it
237 * unnecessarily can even reduce performance, because setting
238 * SO_SNDBUF in the application disables the "dynamic send buffering"
239 * feature that was introduced in Windows 7. So before fiddling with
240 * SO_SNDBUF, check if the current buffer size is already large enough
241 * and only increase it if necessary.
242 *
243 * See https://support.microsoft.com/kb/823764/EN-US/ and
244 * https://msdn.microsoft.com/en-us/library/bb736549%28v=vs.85%29.aspx
245 */
246 optlen = sizeof(oldopt);
247 if (getsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &oldopt,
248 &optlen) < 0)
249 {
251 (errmsg("%s(%s) failed: %m", "getsockopt", "SO_SNDBUF")));
252 }
253 newopt = PQ_SEND_BUFFER_SIZE * 4;
254 if (oldopt < newopt)
255 {
256 if (setsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &newopt,
257 sizeof(newopt)) < 0)
258 {
260 (errmsg("%s(%s) failed: %m", "setsockopt", "SO_SNDBUF")));
261 }
262 }
263#endif
264
265 /*
266 * Also apply the current keepalive parameters. If we fail to set a
267 * parameter, don't error out, because these aren't universally
268 * supported. (Note: you might think we need to reset the GUC
269 * variables to 0 in such a case, but it's not necessary because the
270 * show hooks for these variables report the truth anyway.)
271 */
276 }
277
278 /* initialize state variables */
282 PqCommBusy = false;
283 PqCommReadingMsg = false;
284
285 /* set up process-exit hook to close the socket */
287
288 /*
289 * In backends (as soon as forked) we operate the underlying socket in
290 * nonblocking mode and use latches to implement blocking semantics if
291 * needed. That allows us to provide safely interruptible reads and
292 * writes.
293 */
294#ifndef WIN32
295 if (!pg_set_noblock(port->sock))
297 (errmsg("could not set socket to nonblocking mode: %m")));
298#endif
299
300#ifndef WIN32
301
302 /* Don't give the socket to any subprograms we execute. */
303 if (fcntl(port->sock, F_SETFD, FD_CLOEXEC) < 0)
304 elog(FATAL, "fcntl(F_SETFD) failed on socket: %m");
305#endif
306
309 port->sock, NULL, NULL);
311 MyLatch, NULL);
313 NULL, NULL);
314
315 /*
316 * The event positions match the order we added them, but let's sanity
317 * check them to be sure.
318 */
319 Assert(socket_pos == FeBeWaitSetSocketPos);
320 Assert(latch_pos == FeBeWaitSetLatchPos);
321
322 return port;
323}
324
325/* --------------------------------
326 * socket_comm_reset - reset libpq during error recovery
327 *
328 * This is called from error recovery at the outer idle loop. It's
329 * just to get us out of trouble if we somehow manage to elog() from
330 * inside a pqcomm.c routine (which ideally will never happen, but...)
331 * --------------------------------
332 */
333static void
335{
336 /* Do not throw away pending data, but do reset the busy flag */
337 PqCommBusy = false;
338}
339
340/* --------------------------------
341 * socket_close - shutdown libpq at backend exit
342 *
343 * This is the one pg_on_exit_callback in place during BackendInitialize().
344 * That function's unusual signal handling constrains that this callback be
345 * safe to run at any instant.
346 * --------------------------------
347 */
348static void
350{
351 /* Nothing to do in a standalone backend, where MyProcPort is NULL. */
352 if (MyProcPort != NULL)
353 {
354#ifdef ENABLE_GSS
355 /*
356 * Shutdown GSSAPI layer. This section does nothing when interrupting
357 * BackendInitialize(), because pg_GSS_recvauth() makes first use of
358 * "ctx" and "cred".
359 *
360 * Note that we don't bother to free MyProcPort->gss, since we're
361 * about to exit anyway.
362 */
363 if (MyProcPort->gss)
364 {
365 OM_uint32 min_s;
366
367 if (MyProcPort->gss->ctx != GSS_C_NO_CONTEXT)
368 gss_delete_sec_context(&min_s, &MyProcPort->gss->ctx, NULL);
369
370 if (MyProcPort->gss->cred != GSS_C_NO_CREDENTIAL)
371 gss_release_cred(&min_s, &MyProcPort->gss->cred);
372 }
373#endif /* ENABLE_GSS */
374
375 /*
376 * Cleanly shut down SSL layer. Nowhere else does a postmaster child
377 * call this, so this is safe when interrupting BackendInitialize().
378 */
380
381 /*
382 * Formerly we did an explicit close() here, but it seems better to
383 * leave the socket open until the process dies. This allows clients
384 * to perform a "synchronous close" if they care --- wait till the
385 * transport layer reports connection closure, and you can be sure the
386 * backend has exited.
387 *
388 * We do set sock to PGINVALID_SOCKET to prevent any further I/O,
389 * though.
390 */
392 }
393}
394
395
396
397/* --------------------------------
398 * Postmaster functions to handle sockets.
399 * --------------------------------
400 */
401
402/*
403 * ListenServerPort -- open a "listening" port to accept connections.
404 *
405 * family should be AF_UNIX or AF_UNSPEC; portNumber is the port number.
406 * For AF_UNIX ports, hostName should be NULL and unixSocketDir must be
407 * specified. For TCP ports, hostName is either NULL for all interfaces or
408 * the interface to listen on, and unixSocketDir is ignored (can be NULL).
409 *
410 * Successfully opened sockets are appended to the ListenSockets[] array. On
411 * entry, *NumListenSockets holds the number of elements currently in the
412 * array, and it is updated to reflect the opened sockets. MaxListen is the
413 * allocated size of the array.
414 *
415 * RETURNS: STATUS_OK or STATUS_ERROR
416 */
417int
418ListenServerPort(int family, const char *hostName, unsigned short portNumber,
419 const char *unixSocketDir,
420 pgsocket ListenSockets[], int *NumListenSockets, int MaxListen)
421{
422 pgsocket fd;
423 int err;
424 int maxconn;
425 int ret;
426 char portNumberStr[32];
427 const char *familyDesc;
428 char familyDescBuf[64];
429 const char *addrDesc;
430 char addrBuf[NI_MAXHOST];
431 char *service;
432 struct addrinfo *addrs = NULL,
433 *addr;
434 struct addrinfo hint;
435 int added = 0;
436 char unixSocketPath[MAXPGPATH];
437#if !defined(WIN32) || defined(IPV6_V6ONLY)
438 int one = 1;
439#endif
440
441 /* Initialize hint structure */
442 MemSet(&hint, 0, sizeof(hint));
443 hint.ai_family = family;
444 hint.ai_flags = AI_PASSIVE;
445 hint.ai_socktype = SOCK_STREAM;
446
447 if (family == AF_UNIX)
448 {
449 /*
450 * Create unixSocketPath from portNumber and unixSocketDir and lock
451 * that file path
452 */
453 UNIXSOCK_PATH(unixSocketPath, portNumber, unixSocketDir);
454 if (strlen(unixSocketPath) >= UNIXSOCK_PATH_BUFLEN)
455 {
456 ereport(LOG,
457 (errmsg("Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
458 unixSocketPath,
459 (int) (UNIXSOCK_PATH_BUFLEN - 1))));
460 return STATUS_ERROR;
461 }
462 if (Lock_AF_UNIX(unixSocketDir, unixSocketPath) != STATUS_OK)
463 return STATUS_ERROR;
464 service = unixSocketPath;
465 }
466 else
467 {
468 snprintf(portNumberStr, sizeof(portNumberStr), "%d", portNumber);
469 service = portNumberStr;
470 }
471
472 ret = pg_getaddrinfo_all(hostName, service, &hint, &addrs);
473 if (ret || !addrs)
474 {
475 if (hostName)
476 ereport(LOG,
477 (errmsg("could not translate host name \"%s\", service \"%s\" to address: %s",
478 hostName, service, gai_strerror(ret))));
479 else
480 ereport(LOG,
481 (errmsg("could not translate service \"%s\" to address: %s",
482 service, gai_strerror(ret))));
483 if (addrs)
484 pg_freeaddrinfo_all(hint.ai_family, addrs);
485 return STATUS_ERROR;
486 }
487
488 for (addr = addrs; addr; addr = addr->ai_next)
489 {
490 if (family != AF_UNIX && addr->ai_family == AF_UNIX)
491 {
492 /*
493 * Only set up a unix domain socket when they really asked for it.
494 * The service/port is different in that case.
495 */
496 continue;
497 }
498
499 /* See if there is still room to add 1 more socket. */
500 if (*NumListenSockets == MaxListen)
501 {
502 ereport(LOG,
503 (errmsg("could not bind to all requested addresses: MAXLISTEN (%d) exceeded",
504 MaxListen)));
505 break;
506 }
507
508 /* set up address family name for log messages */
509 switch (addr->ai_family)
510 {
511 case AF_INET:
512 familyDesc = _("IPv4");
513 break;
514 case AF_INET6:
515 familyDesc = _("IPv6");
516 break;
517 case AF_UNIX:
518 familyDesc = _("Unix");
519 break;
520 default:
521 snprintf(familyDescBuf, sizeof(familyDescBuf),
522 _("unrecognized address family %d"),
523 addr->ai_family);
524 familyDesc = familyDescBuf;
525 break;
526 }
527
528 /* set up text form of address for log messages */
529 if (addr->ai_family == AF_UNIX)
530 addrDesc = unixSocketPath;
531 else
532 {
533 pg_getnameinfo_all((const struct sockaddr_storage *) addr->ai_addr,
534 addr->ai_addrlen,
535 addrBuf, sizeof(addrBuf),
536 NULL, 0,
537 NI_NUMERICHOST);
538 addrDesc = addrBuf;
539 }
540
541 if ((fd = socket(addr->ai_family, SOCK_STREAM, 0)) == PGINVALID_SOCKET)
542 {
543 ereport(LOG,
545 /* translator: first %s is IPv4, IPv6, or Unix */
546 errmsg("could not create %s socket for address \"%s\": %m",
547 familyDesc, addrDesc)));
548 continue;
549 }
550
551#ifndef WIN32
552 /* Don't give the listen socket to any subprograms we execute. */
553 if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0)
554 elog(FATAL, "fcntl(F_SETFD) failed on socket: %m");
555
556 /*
557 * Without the SO_REUSEADDR flag, a new postmaster can't be started
558 * right away after a stop or crash, giving "address already in use"
559 * error on TCP ports.
560 *
561 * On win32, however, this behavior only happens if the
562 * SO_EXCLUSIVEADDRUSE is set. With SO_REUSEADDR, win32 allows
563 * multiple servers to listen on the same address, resulting in
564 * unpredictable behavior. With no flags at all, win32 behaves as Unix
565 * with SO_REUSEADDR.
566 */
567 if (addr->ai_family != AF_UNIX)
568 {
569 if ((setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
570 (char *) &one, sizeof(one))) == -1)
571 {
572 ereport(LOG,
574 /* translator: third %s is IPv4, IPv6, or Unix */
575 errmsg("%s(%s) failed for %s address \"%s\": %m",
576 "setsockopt", "SO_REUSEADDR",
577 familyDesc, addrDesc)));
579 continue;
580 }
581 }
582#endif
583
584#ifdef IPV6_V6ONLY
585 if (addr->ai_family == AF_INET6)
586 {
587 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
588 (char *) &one, sizeof(one)) == -1)
589 {
590 ereport(LOG,
592 /* translator: third %s is IPv4, IPv6, or Unix */
593 errmsg("%s(%s) failed for %s address \"%s\": %m",
594 "setsockopt", "IPV6_V6ONLY",
595 familyDesc, addrDesc)));
597 continue;
598 }
599 }
600#endif
601
602 /*
603 * Note: This might fail on some OS's, like Linux older than
604 * 2.4.21-pre3, that don't have the IPV6_V6ONLY socket option, and map
605 * ipv4 addresses to ipv6. It will show ::ffff:ipv4 for all ipv4
606 * connections.
607 */
608 err = bind(fd, addr->ai_addr, addr->ai_addrlen);
609 if (err < 0)
610 {
611 int saved_errno = errno;
612
613 ereport(LOG,
615 /* translator: first %s is IPv4, IPv6, or Unix */
616 errmsg("could not bind %s address \"%s\": %m",
617 familyDesc, addrDesc),
618 saved_errno == EADDRINUSE ?
619 (addr->ai_family == AF_UNIX ?
620 errhint("Is another postmaster already running on port %d?",
621 (int) portNumber) :
622 errhint("Is another postmaster already running on port %d?"
623 " If not, wait a few seconds and retry.",
624 (int) portNumber)) : 0));
626 continue;
627 }
628
629 if (addr->ai_family == AF_UNIX)
630 {
631 if (Setup_AF_UNIX(service) != STATUS_OK)
632 {
634 break;
635 }
636 }
637
638 /*
639 * Select appropriate accept-queue length limit. It seems reasonable
640 * to use a value similar to the maximum number of child processes
641 * that the postmaster will permit.
642 */
643 maxconn = MaxConnections * 2;
644
645 err = listen(fd, maxconn);
646 if (err < 0)
647 {
648 ereport(LOG,
650 /* translator: first %s is IPv4, IPv6, or Unix */
651 errmsg("could not listen on %s address \"%s\": %m",
652 familyDesc, addrDesc)));
654 continue;
655 }
656
657 if (addr->ai_family == AF_UNIX)
658 ereport(LOG,
659 (errmsg("listening on Unix socket \"%s\"",
660 addrDesc)));
661 else
662 ereport(LOG,
663 /* translator: first %s is IPv4 or IPv6 */
664 (errmsg("listening on %s address \"%s\", port %d",
665 familyDesc, addrDesc, (int) portNumber)));
666
668 (*NumListenSockets)++;
669 added++;
670 }
671
672 pg_freeaddrinfo_all(hint.ai_family, addrs);
673
674 if (!added)
675 return STATUS_ERROR;
676
677 return STATUS_OK;
678}
679
680
681/*
682 * Lock_AF_UNIX -- configure unix socket file path
683 */
684static int
685Lock_AF_UNIX(const char *unixSocketDir, const char *unixSocketPath)
686{
687 /* no lock file for abstract sockets */
688 if (unixSocketPath[0] == '@')
689 return STATUS_OK;
690
691 /*
692 * Grab an interlock file associated with the socket file.
693 *
694 * Note: there are two reasons for using a socket lock file, rather than
695 * trying to interlock directly on the socket itself. First, it's a lot
696 * more portable, and second, it lets us remove any pre-existing socket
697 * file without race conditions.
698 */
699 CreateSocketLockFile(unixSocketPath, true, unixSocketDir);
700
701 /*
702 * Once we have the interlock, we can safely delete any pre-existing
703 * socket file to avoid failure at bind() time.
704 */
705 (void) unlink(unixSocketPath);
706
707 /*
708 * Remember socket file pathnames for later maintenance.
709 */
710 sock_paths = lappend(sock_paths, pstrdup(unixSocketPath));
711
712 return STATUS_OK;
713}
714
715
716/*
717 * Setup_AF_UNIX -- configure unix socket permissions
718 */
719static int
720Setup_AF_UNIX(const char *sock_path)
721{
722 /* no file system permissions for abstract sockets */
723 if (sock_path[0] == '@')
724 return STATUS_OK;
725
726 /*
727 * Fix socket ownership/permission if requested. Note we must do this
728 * before we listen() to avoid a window where unwanted connections could
729 * get accepted.
730 */
732 if (Unix_socket_group[0] != '\0')
733 {
734#ifdef WIN32
735 elog(WARNING, "configuration item \"unix_socket_group\" is not supported on this platform");
736#else
737 char *endptr;
738 unsigned long val;
739 gid_t gid;
740
741 val = strtoul(Unix_socket_group, &endptr, 10);
742 if (*endptr == '\0')
743 { /* numeric group id */
744 gid = val;
745 }
746 else
747 { /* convert group name to id */
748 struct group *gr;
749
750 gr = getgrnam(Unix_socket_group);
751 if (!gr)
752 {
753 ereport(LOG,
754 (errmsg("group \"%s\" does not exist",
756 return STATUS_ERROR;
757 }
758 gid = gr->gr_gid;
759 }
760 if (chown(sock_path, -1, gid) == -1)
761 {
762 ereport(LOG,
764 errmsg("could not set group of file \"%s\": %m",
765 sock_path)));
766 return STATUS_ERROR;
767 }
768#endif
769 }
770
771 if (chmod(sock_path, Unix_socket_permissions) == -1)
772 {
773 ereport(LOG,
775 errmsg("could not set permissions of file \"%s\": %m",
776 sock_path)));
777 return STATUS_ERROR;
778 }
779 return STATUS_OK;
780}
781
782
783/*
784 * AcceptConnection -- accept a new connection with client using
785 * server port. Fills *client_sock with the FD and endpoint info
786 * of the new connection.
787 *
788 * ASSUME: that this doesn't need to be non-blocking because
789 * the Postmaster waits for the socket to be ready to accept().
790 *
791 * RETURNS: STATUS_OK or STATUS_ERROR
792 */
793int
794AcceptConnection(pgsocket server_fd, ClientSocket *client_sock)
795{
796 /* accept connection and fill in the client (remote) address */
797 client_sock->raddr.salen = sizeof(client_sock->raddr.addr);
798 if ((client_sock->sock = accept(server_fd,
799 (struct sockaddr *) &client_sock->raddr.addr,
800 &client_sock->raddr.salen)) == PGINVALID_SOCKET)
801 {
802 ereport(LOG,
804 errmsg("could not accept new connection: %m")));
805
806 /*
807 * If accept() fails then postmaster.c will still see the server
808 * socket as read-ready, and will immediately try again. To avoid
809 * uselessly sucking lots of CPU, delay a bit before trying again.
810 * (The most likely reason for failure is being out of kernel file
811 * table slots; we can do little except hope some will get freed up.)
812 */
813 pg_usleep(100000L); /* wait 0.1 sec */
814 return STATUS_ERROR;
815 }
816
817 return STATUS_OK;
818}
819
820/*
821 * TouchSocketFiles -- mark socket files as recently accessed
822 *
823 * This routine should be called every so often to ensure that the socket
824 * files have a recent mod date (ordinary operations on sockets usually won't
825 * change the mod date). That saves them from being removed by
826 * overenthusiastic /tmp-directory-cleaner daemons. (Another reason we should
827 * never have put the socket file in /tmp...)
828 */
829void
831{
832 ListCell *l;
833
834 /* Loop through all created sockets... */
835 foreach(l, sock_paths)
836 {
837 char *sock_path = (char *) lfirst(l);
838
839 /* Ignore errors; there's no point in complaining */
840 (void) utime(sock_path, NULL);
841 }
842}
843
844/*
845 * RemoveSocketFiles -- unlink socket files at postmaster shutdown
846 */
847void
849{
850 ListCell *l;
851
852 /* Loop through all created sockets... */
853 foreach(l, sock_paths)
854 {
855 char *sock_path = (char *) lfirst(l);
856
857 /* Ignore any error. */
858 (void) unlink(sock_path);
859 }
860 /* Since we're about to exit, no need to reclaim storage */
861 sock_paths = NIL;
862}
863
864
865/* --------------------------------
866 * Low-level I/O routines begin here.
867 *
868 * These routines communicate with a frontend client across a connection
869 * already established by the preceding routines.
870 * --------------------------------
871 */
872
873/* --------------------------------
874 * socket_set_nonblocking - set socket blocking/non-blocking
875 *
876 * Sets the socket non-blocking if nonblocking is true, or sets it
877 * blocking otherwise.
878 * --------------------------------
879 */
880static void
881socket_set_nonblocking(bool nonblocking)
882{
883 if (MyProcPort == NULL)
885 (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
886 errmsg("there is no client connection")));
887
888 MyProcPort->noblock = nonblocking;
889}
890
891/* --------------------------------
892 * pq_recvbuf - load some bytes into the input buffer
893 *
894 * returns 0 if OK, EOF if trouble
895 * --------------------------------
896 */
897static int
899{
900 if (PqRecvPointer > 0)
901 {
903 {
904 /* still some unread data, left-justify it in the buffer */
908 PqRecvPointer = 0;
909 }
910 else
912 }
913
914 /* Ensure that we're in blocking mode */
916
917 /* Can fill buffer from PqRecvLength and upwards */
918 for (;;)
919 {
920 int r;
921
922 errno = 0;
923
926
927 if (r < 0)
928 {
929 if (errno == EINTR)
930 continue; /* Ok if interrupted */
931
932 /*
933 * Careful: an ereport() that tries to write to the client would
934 * cause recursion to here, leading to stack overflow and core
935 * dump! This message must go *only* to the postmaster log.
936 *
937 * If errno is zero, assume it's EOF and let the caller complain.
938 */
939 if (errno != 0)
942 errmsg("could not receive data from client: %m")));
943 return EOF;
944 }
945 if (r == 0)
946 {
947 /*
948 * EOF detected. We used to write a log message here, but it's
949 * better to expect the ultimate caller to do that.
950 */
951 return EOF;
952 }
953 /* r contains number of bytes read, so just incr length */
954 PqRecvLength += r;
955 return 0;
956 }
957}
958
959/* --------------------------------
960 * pq_getbyte - get a single byte from connection, or return EOF
961 * --------------------------------
962 */
963int
965{
967
968 while (PqRecvPointer >= PqRecvLength)
969 {
970 if (pq_recvbuf()) /* If nothing in buffer, then recv some */
971 return EOF; /* Failed to recv data */
972 }
973 return (unsigned char) PqRecvBuffer[PqRecvPointer++];
974}
975
976/* --------------------------------
977 * pq_peekbyte - peek at next byte from connection
978 *
979 * Same as pq_getbyte() except we don't advance the pointer.
980 * --------------------------------
981 */
982int
984{
986
987 while (PqRecvPointer >= PqRecvLength)
988 {
989 if (pq_recvbuf()) /* If nothing in buffer, then recv some */
990 return EOF; /* Failed to recv data */
991 }
992 return (unsigned char) PqRecvBuffer[PqRecvPointer];
993}
994
995/* --------------------------------
996 * pq_getbyte_if_available - get a single byte from connection,
997 * if available
998 *
999 * The received byte is stored in *c. Returns 1 if a byte was read,
1000 * 0 if no data was available, or EOF if trouble.
1001 * --------------------------------
1002 */
1003int
1005{
1006 int r;
1007
1009
1011 {
1013 return 1;
1014 }
1015
1016 /* Put the socket into non-blocking mode */
1018
1019 errno = 0;
1020
1021 r = secure_read(MyProcPort, c, 1);
1022 if (r < 0)
1023 {
1024 /*
1025 * Ok if no data available without blocking or interrupted (though
1026 * EINTR really shouldn't happen with a non-blocking socket). Report
1027 * other errors.
1028 */
1029 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
1030 r = 0;
1031 else
1032 {
1033 /*
1034 * Careful: an ereport() that tries to write to the client would
1035 * cause recursion to here, leading to stack overflow and core
1036 * dump! This message must go *only* to the postmaster log.
1037 *
1038 * If errno is zero, assume it's EOF and let the caller complain.
1039 */
1040 if (errno != 0)
1043 errmsg("could not receive data from client: %m")));
1044 r = EOF;
1045 }
1046 }
1047 else if (r == 0)
1048 {
1049 /* EOF detected */
1050 r = EOF;
1051 }
1052
1053 return r;
1054}
1055
1056/* --------------------------------
1057 * pq_getbytes - get a known number of bytes from connection
1058 *
1059 * returns 0 if OK, EOF if trouble
1060 * --------------------------------
1061 */
1062int
1063pq_getbytes(char *s, size_t len)
1064{
1065 size_t amount;
1066
1068
1069 while (len > 0)
1070 {
1071 while (PqRecvPointer >= PqRecvLength)
1072 {
1073 if (pq_recvbuf()) /* If nothing in buffer, then recv some */
1074 return EOF; /* Failed to recv data */
1075 }
1076 amount = PqRecvLength - PqRecvPointer;
1077 if (amount > len)
1078 amount = len;
1079 memcpy(s, PqRecvBuffer + PqRecvPointer, amount);
1080 PqRecvPointer += amount;
1081 s += amount;
1082 len -= amount;
1083 }
1084 return 0;
1085}
1086
1087/* --------------------------------
1088 * pq_discardbytes - throw away a known number of bytes
1089 *
1090 * same as pq_getbytes except we do not copy the data to anyplace.
1091 * this is used for resynchronizing after read errors.
1092 *
1093 * returns 0 if OK, EOF if trouble
1094 * --------------------------------
1095 */
1096static int
1098{
1099 size_t amount;
1100
1102
1103 while (len > 0)
1104 {
1105 while (PqRecvPointer >= PqRecvLength)
1106 {
1107 if (pq_recvbuf()) /* If nothing in buffer, then recv some */
1108 return EOF; /* Failed to recv data */
1109 }
1110 amount = PqRecvLength - PqRecvPointer;
1111 if (amount > len)
1112 amount = len;
1113 PqRecvPointer += amount;
1114 len -= amount;
1115 }
1116 return 0;
1117}
1118
1119/* --------------------------------
1120 * pq_buffer_remaining_data - return number of bytes in receive buffer
1121 *
1122 * This will *not* attempt to read more data. And reading up to that number of
1123 * bytes should not cause reading any more data either.
1124 * --------------------------------
1125 */
1126ssize_t
1128{
1130 return (PqRecvLength - PqRecvPointer);
1131}
1132
1133
1134/* --------------------------------
1135 * pq_startmsgread - begin reading a message from the client.
1136 *
1137 * This must be called before any of the pq_get* functions.
1138 * --------------------------------
1139 */
1140void
1142{
1143 /*
1144 * There shouldn't be a read active already, but let's check just to be
1145 * sure.
1146 */
1147 if (PqCommReadingMsg)
1148 ereport(FATAL,
1149 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1150 errmsg("terminating connection because protocol synchronization was lost")));
1151
1152 PqCommReadingMsg = true;
1153}
1154
1155
1156/* --------------------------------
1157 * pq_endmsgread - finish reading message.
1158 *
1159 * This must be called after reading a message with pq_getbytes()
1160 * and friends, to indicate that we have read the whole message.
1161 * pq_getmessage() does this implicitly.
1162 * --------------------------------
1163 */
1164void
1166{
1168
1169 PqCommReadingMsg = false;
1170}
1171
1172/* --------------------------------
1173 * pq_is_reading_msg - are we currently reading a message?
1174 *
1175 * This is used in error recovery at the outer idle loop to detect if we have
1176 * lost protocol sync, and need to terminate the connection. pq_startmsgread()
1177 * will check for that too, but it's nicer to detect it earlier.
1178 * --------------------------------
1179 */
1180bool
1182{
1183 return PqCommReadingMsg;
1184}
1185
1186/* --------------------------------
1187 * pq_getmessage - get a message with length word from connection
1188 *
1189 * The return value is placed in an expansible StringInfo, which has
1190 * already been initialized by the caller.
1191 * Only the message body is placed in the StringInfo; the length word
1192 * is removed. Also, s->cursor is initialized to zero for convenience
1193 * in scanning the message contents.
1194 *
1195 * maxlen is the upper limit on the length of the
1196 * message we are willing to accept. We abort the connection (by
1197 * returning EOF) if client tries to send more than that.
1198 *
1199 * returns 0 if OK, EOF if trouble
1200 * --------------------------------
1201 */
1202int
1204{
1205 int32 len;
1206
1208
1209 resetStringInfo(s);
1210
1211 /* Read message length word */
1212 if (pq_getbytes((char *) &len, 4) == EOF)
1213 {
1215 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1216 errmsg("unexpected EOF within message length word")));
1217 return EOF;
1218 }
1219
1220 len = pg_ntoh32(len);
1221
1222 if (len < 4 || len > maxlen)
1223 {
1225 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1226 errmsg("invalid message length")));
1227 return EOF;
1228 }
1229
1230 len -= 4; /* discount length itself */
1231
1232 if (len > 0)
1233 {
1234 /*
1235 * Allocate space for message. If we run out of room (ridiculously
1236 * large message), we will elog(ERROR), but we want to discard the
1237 * message body so as not to lose communication sync.
1238 */
1239 PG_TRY();
1240 {
1242 }
1243 PG_CATCH();
1244 {
1245 if (pq_discardbytes(len) == EOF)
1247 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1248 errmsg("incomplete message from client")));
1249
1250 /* we discarded the rest of the message so we're back in sync. */
1251 PqCommReadingMsg = false;
1252 PG_RE_THROW();
1253 }
1254 PG_END_TRY();
1255
1256 /* And grab the message */
1257 if (pq_getbytes(s->data, len) == EOF)
1258 {
1260 (errcode(ERRCODE_PROTOCOL_VIOLATION),
1261 errmsg("incomplete message from client")));
1262 return EOF;
1263 }
1264 s->len = len;
1265 /* Place a trailing null per StringInfo convention */
1266 s->data[len] = '\0';
1267 }
1268
1269 /* finished reading the message. */
1270 PqCommReadingMsg = false;
1271
1272 return 0;
1273}
1274
1275
1276static inline int
1277internal_putbytes(const char *s, size_t len)
1278{
1279 while (len > 0)
1280 {
1281 /* If buffer is full, then flush it out */
1283 {
1285 if (internal_flush())
1286 return EOF;
1287 }
1288
1289 /*
1290 * If the buffer is empty and data length is larger than the buffer
1291 * size, send it without buffering. Otherwise, copy as much data as
1292 * possible into the buffer.
1293 */
1295 {
1296 size_t start = 0;
1297
1299 if (internal_flush_buffer(s, &start, &len))
1300 return EOF;
1301 }
1302 else
1303 {
1304 size_t amount = PqSendBufferSize - PqSendPointer;
1305
1306 if (amount > len)
1307 amount = len;
1308 memcpy(PqSendBuffer + PqSendPointer, s, amount);
1309 PqSendPointer += amount;
1310 s += amount;
1311 len -= amount;
1312 }
1313 }
1314
1315 return 0;
1316}
1317
1318/* --------------------------------
1319 * socket_flush - flush pending output
1320 *
1321 * returns 0 if OK, EOF if trouble
1322 * --------------------------------
1323 */
1324static int
1326{
1327 int res;
1328
1329 /* No-op if reentrant call */
1330 if (PqCommBusy)
1331 return 0;
1332 PqCommBusy = true;
1334 res = internal_flush();
1335 PqCommBusy = false;
1336 return res;
1337}
1338
1339/* --------------------------------
1340 * internal_flush - flush pending output
1341 *
1342 * Returns 0 if OK (meaning everything was sent, or operation would block
1343 * and the socket is in non-blocking mode), or EOF if trouble.
1344 * --------------------------------
1345 */
1346static inline int
1348{
1350}
1351
1352/* --------------------------------
1353 * internal_flush_buffer - flush the given buffer content
1354 *
1355 * Returns 0 if OK (meaning everything was sent, or operation would block
1356 * and the socket is in non-blocking mode), or EOF if trouble.
1357 * --------------------------------
1358 */
1359static pg_noinline int
1360internal_flush_buffer(const char *buf, size_t *start, size_t *end)
1361{
1362 static int last_reported_send_errno = 0;
1363
1364 const char *bufptr = buf + *start;
1365 const char *bufend = buf + *end;
1366
1367 while (bufptr < bufend)
1368 {
1369 int r;
1370
1371 r = secure_write(MyProcPort, (char *) bufptr, bufend - bufptr);
1372
1373 if (r <= 0)
1374 {
1375 if (errno == EINTR)
1376 continue; /* Ok if we were interrupted */
1377
1378 /*
1379 * Ok if no data writable without blocking, and the socket is in
1380 * non-blocking mode.
1381 */
1382 if (errno == EAGAIN ||
1383 errno == EWOULDBLOCK)
1384 {
1385 return 0;
1386 }
1387
1388 /*
1389 * Careful: an ereport() that tries to write to the client would
1390 * cause recursion to here, leading to stack overflow and core
1391 * dump! This message must go *only* to the postmaster log.
1392 *
1393 * If a client disconnects while we're in the midst of output, we
1394 * might write quite a bit of data before we get to a safe query
1395 * abort point. So, suppress duplicate log messages.
1396 */
1397 if (errno != last_reported_send_errno)
1398 {
1399 last_reported_send_errno = errno;
1402 errmsg("could not send data to client: %m")));
1403 }
1404
1405 /*
1406 * We drop the buffered data anyway so that processing can
1407 * continue, even though we'll probably quit soon. We also set a
1408 * flag that'll cause the next CHECK_FOR_INTERRUPTS to terminate
1409 * the connection.
1410 */
1411 *start = *end = 0;
1413 InterruptPending = 1;
1414 return EOF;
1415 }
1416
1417 last_reported_send_errno = 0; /* reset after any successful send */
1418 bufptr += r;
1419 *start += r;
1420 }
1421
1422 *start = *end = 0;
1423 return 0;
1424}
1425
1426/* --------------------------------
1427 * pq_flush_if_writable - flush pending output if writable without blocking
1428 *
1429 * Returns 0 if OK, or EOF if trouble.
1430 * --------------------------------
1431 */
1432static int
1434{
1435 int res;
1436
1437 /* Quick exit if nothing to do */
1439 return 0;
1440
1441 /* No-op if reentrant call */
1442 if (PqCommBusy)
1443 return 0;
1444
1445 /* Temporarily put the socket into non-blocking mode */
1447
1448 PqCommBusy = true;
1449 res = internal_flush();
1450 PqCommBusy = false;
1451 return res;
1452}
1453
1454/* --------------------------------
1455 * socket_is_send_pending - is there any pending data in the output buffer?
1456 * --------------------------------
1457 */
1458static bool
1460{
1461 return (PqSendStart < PqSendPointer);
1462}
1463
1464/* --------------------------------
1465 * Message-level I/O routines begin here.
1466 * --------------------------------
1467 */
1468
1469
1470/* --------------------------------
1471 * socket_putmessage - send a normal message (suppressed in COPY OUT mode)
1472 *
1473 * msgtype is a message type code to place before the message body.
1474 *
1475 * len is the length of the message body data at *s. A message length
1476 * word (equal to len+4 because it counts itself too) is inserted by this
1477 * routine.
1478 *
1479 * We suppress messages generated while pqcomm.c is busy. This
1480 * avoids any possibility of messages being inserted within other
1481 * messages. The only known trouble case arises if SIGQUIT occurs
1482 * during a pqcomm.c routine --- quickdie() will try to send a warning
1483 * message, and the most reasonable approach seems to be to drop it.
1484 *
1485 * returns 0 if OK, EOF if trouble
1486 * --------------------------------
1487 */
1488static int
1489socket_putmessage(char msgtype, const char *s, size_t len)
1490{
1491 uint32 n32;
1492
1493 Assert(msgtype != 0);
1494
1495 if (PqCommBusy)
1496 return 0;
1497 PqCommBusy = true;
1498 if (internal_putbytes(&msgtype, 1))
1499 goto fail;
1500
1501 n32 = pg_hton32((uint32) (len + 4));
1502 if (internal_putbytes((char *) &n32, 4))
1503 goto fail;
1504
1505 if (internal_putbytes(s, len))
1506 goto fail;
1507 PqCommBusy = false;
1508 return 0;
1509
1510fail:
1511 PqCommBusy = false;
1512 return EOF;
1513}
1514
1515/* --------------------------------
1516 * pq_putmessage_noblock - like pq_putmessage, but never blocks
1517 *
1518 * If the output buffer is too small to hold the message, the buffer
1519 * is enlarged.
1520 */
1521static void
1522socket_putmessage_noblock(char msgtype, const char *s, size_t len)
1523{
1525 int required;
1526
1527 /*
1528 * Ensure we have enough space in the output buffer for the message header
1529 * as well as the message itself.
1530 */
1531 required = PqSendPointer + 1 + 4 + len;
1533 {
1536 }
1537 res = pq_putmessage(msgtype, s, len);
1538 Assert(res == 0); /* should not fail when the message fits in
1539 * buffer */
1540}
1541
1542/* --------------------------------
1543 * pq_putmessage_v2 - send a message in protocol version 2
1544 *
1545 * msgtype is a message type code to place before the message body.
1546 *
1547 * We no longer support protocol version 2, but we have kept this
1548 * function so that if a client tries to connect with protocol version 2,
1549 * as a courtesy we can still send the "unsupported protocol version"
1550 * error to the client in the old format.
1551 *
1552 * Like in pq_putmessage(), we suppress messages generated while
1553 * pqcomm.c is busy.
1554 *
1555 * returns 0 if OK, EOF if trouble
1556 * --------------------------------
1557 */
1558int
1559pq_putmessage_v2(char msgtype, const char *s, size_t len)
1560{
1561 Assert(msgtype != 0);
1562
1563 if (PqCommBusy)
1564 return 0;
1565 PqCommBusy = true;
1566 if (internal_putbytes(&msgtype, 1))
1567 goto fail;
1568
1569 if (internal_putbytes(s, len))
1570 goto fail;
1571 PqCommBusy = false;
1572 return 0;
1573
1574fail:
1575 PqCommBusy = false;
1576 return EOF;
1577}
1578
1579/*
1580 * Support for TCP Keepalive parameters
1581 */
1582
1583/*
1584 * On Windows, we need to set both idle and interval at the same time.
1585 * We also cannot reset them to the default (setting to zero will
1586 * actually set them to zero, not default), therefore we fallback to
1587 * the out-of-the-box default instead.
1588 */
1589#if defined(WIN32) && defined(SIO_KEEPALIVE_VALS)
1590static int
1591pq_setkeepaliveswin32(Port *port, int idle, int interval)
1592{
1593 struct tcp_keepalive ka;
1594 DWORD retsize;
1595
1596 if (idle <= 0)
1597 idle = 2 * 60 * 60; /* default = 2 hours */
1598 if (interval <= 0)
1599 interval = 1; /* default = 1 second */
1600
1601 ka.onoff = 1;
1602 ka.keepalivetime = idle * 1000;
1603 ka.keepaliveinterval = interval * 1000;
1604
1605 if (WSAIoctl(port->sock,
1606 SIO_KEEPALIVE_VALS,
1607 (LPVOID) &ka,
1608 sizeof(ka),
1609 NULL,
1610 0,
1611 &retsize,
1612 NULL,
1613 NULL)
1614 != 0)
1615 {
1616 ereport(LOG,
1617 (errmsg("%s(%s) failed: error code %d",
1618 "WSAIoctl", "SIO_KEEPALIVE_VALS", WSAGetLastError())));
1619 return STATUS_ERROR;
1620 }
1621 if (port->keepalives_idle != idle)
1622 port->keepalives_idle = idle;
1623 if (port->keepalives_interval != interval)
1624 port->keepalives_interval = interval;
1625 return STATUS_OK;
1626}
1627#endif
1628
1629int
1631{
1632#if defined(PG_TCP_KEEPALIVE_IDLE) || defined(SIO_KEEPALIVE_VALS)
1633 if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1634 return 0;
1635
1636 if (port->keepalives_idle != 0)
1637 return port->keepalives_idle;
1638
1639 if (port->default_keepalives_idle == 0)
1640 {
1641#ifndef WIN32
1642 socklen_t size = sizeof(port->default_keepalives_idle);
1643
1644 if (getsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
1645 (char *) &port->default_keepalives_idle,
1646 &size) < 0)
1647 {
1648 ereport(LOG,
1649 (errmsg("%s(%s) failed: %m", "getsockopt", PG_TCP_KEEPALIVE_IDLE_STR)));
1650 port->default_keepalives_idle = -1; /* don't know */
1651 }
1652#else /* WIN32 */
1653 /* We can't get the defaults on Windows, so return "don't know" */
1654 port->default_keepalives_idle = -1;
1655#endif /* WIN32 */
1656 }
1657
1658 return port->default_keepalives_idle;
1659#else
1660 return 0;
1661#endif
1662}
1663
1664int
1666{
1667 if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1668 return STATUS_OK;
1669
1670/* check SIO_KEEPALIVE_VALS here, not just WIN32, as some toolchains lack it */
1671#if defined(PG_TCP_KEEPALIVE_IDLE) || defined(SIO_KEEPALIVE_VALS)
1672 if (idle == port->keepalives_idle)
1673 return STATUS_OK;
1674
1675#ifndef WIN32
1676 if (port->default_keepalives_idle <= 0)
1677 {
1678 if (pq_getkeepalivesidle(port) < 0)
1679 {
1680 if (idle == 0)
1681 return STATUS_OK; /* default is set but unknown */
1682 else
1683 return STATUS_ERROR;
1684 }
1685 }
1686
1687 if (idle == 0)
1688 idle = port->default_keepalives_idle;
1689
1690 if (setsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
1691 (char *) &idle, sizeof(idle)) < 0)
1692 {
1693 ereport(LOG,
1694 (errmsg("%s(%s) failed: %m", "setsockopt", PG_TCP_KEEPALIVE_IDLE_STR)));
1695 return STATUS_ERROR;
1696 }
1697
1698 port->keepalives_idle = idle;
1699#else /* WIN32 */
1700 return pq_setkeepaliveswin32(port, idle, port->keepalives_interval);
1701#endif
1702#else
1703 if (idle != 0)
1704 {
1705 ereport(LOG,
1706 (errmsg("setting the keepalive idle time is not supported")));
1707 return STATUS_ERROR;
1708 }
1709#endif
1710
1711 return STATUS_OK;
1712}
1713
1714int
1716{
1717#if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
1718 if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1719 return 0;
1720
1721 if (port->keepalives_interval != 0)
1722 return port->keepalives_interval;
1723
1724 if (port->default_keepalives_interval == 0)
1725 {
1726#ifndef WIN32
1727 socklen_t size = sizeof(port->default_keepalives_interval);
1728
1729 if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
1730 (char *) &port->default_keepalives_interval,
1731 &size) < 0)
1732 {
1733 ereport(LOG,
1734 (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_KEEPINTVL")));
1735 port->default_keepalives_interval = -1; /* don't know */
1736 }
1737#else
1738 /* We can't get the defaults on Windows, so return "don't know" */
1739 port->default_keepalives_interval = -1;
1740#endif /* WIN32 */
1741 }
1742
1743 return port->default_keepalives_interval;
1744#else
1745 return 0;
1746#endif
1747}
1748
1749int
1751{
1752 if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1753 return STATUS_OK;
1754
1755#if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
1756 if (interval == port->keepalives_interval)
1757 return STATUS_OK;
1758
1759#ifndef WIN32
1760 if (port->default_keepalives_interval <= 0)
1761 {
1763 {
1764 if (interval == 0)
1765 return STATUS_OK; /* default is set but unknown */
1766 else
1767 return STATUS_ERROR;
1768 }
1769 }
1770
1771 if (interval == 0)
1772 interval = port->default_keepalives_interval;
1773
1774 if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
1775 (char *) &interval, sizeof(interval)) < 0)
1776 {
1777 ereport(LOG,
1778 (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_KEEPINTVL")));
1779 return STATUS_ERROR;
1780 }
1781
1782 port->keepalives_interval = interval;
1783#else /* WIN32 */
1784 return pq_setkeepaliveswin32(port, port->keepalives_idle, interval);
1785#endif
1786#else
1787 if (interval != 0)
1788 {
1789 ereport(LOG,
1790 (errmsg("%s(%s) not supported", "setsockopt", "TCP_KEEPINTVL")));
1791 return STATUS_ERROR;
1792 }
1793#endif
1794
1795 return STATUS_OK;
1796}
1797
1798int
1800{
1801#ifdef TCP_KEEPCNT
1802 if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1803 return 0;
1804
1805 if (port->keepalives_count != 0)
1806 return port->keepalives_count;
1807
1808 if (port->default_keepalives_count == 0)
1809 {
1810 socklen_t size = sizeof(port->default_keepalives_count);
1811
1812 if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
1813 (char *) &port->default_keepalives_count,
1814 &size) < 0)
1815 {
1816 ereport(LOG,
1817 (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_KEEPCNT")));
1818 port->default_keepalives_count = -1; /* don't know */
1819 }
1820 }
1821
1822 return port->default_keepalives_count;
1823#else
1824 return 0;
1825#endif
1826}
1827
1828int
1830{
1831 if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1832 return STATUS_OK;
1833
1834#ifdef TCP_KEEPCNT
1835 if (count == port->keepalives_count)
1836 return STATUS_OK;
1837
1838 if (port->default_keepalives_count <= 0)
1839 {
1840 if (pq_getkeepalivescount(port) < 0)
1841 {
1842 if (count == 0)
1843 return STATUS_OK; /* default is set but unknown */
1844 else
1845 return STATUS_ERROR;
1846 }
1847 }
1848
1849 if (count == 0)
1850 count = port->default_keepalives_count;
1851
1852 if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
1853 (char *) &count, sizeof(count)) < 0)
1854 {
1855 ereport(LOG,
1856 (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_KEEPCNT")));
1857 return STATUS_ERROR;
1858 }
1859
1860 port->keepalives_count = count;
1861#else
1862 if (count != 0)
1863 {
1864 ereport(LOG,
1865 (errmsg("%s(%s) not supported", "setsockopt", "TCP_KEEPCNT")));
1866 return STATUS_ERROR;
1867 }
1868#endif
1869
1870 return STATUS_OK;
1871}
1872
1873int
1875{
1876#ifdef TCP_USER_TIMEOUT
1877 if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1878 return 0;
1879
1880 if (port->tcp_user_timeout != 0)
1881 return port->tcp_user_timeout;
1882
1883 if (port->default_tcp_user_timeout == 0)
1884 {
1885 socklen_t size = sizeof(port->default_tcp_user_timeout);
1886
1887 if (getsockopt(port->sock, IPPROTO_TCP, TCP_USER_TIMEOUT,
1888 (char *) &port->default_tcp_user_timeout,
1889 &size) < 0)
1890 {
1891 ereport(LOG,
1892 (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_USER_TIMEOUT")));
1893 port->default_tcp_user_timeout = -1; /* don't know */
1894 }
1895 }
1896
1897 return port->default_tcp_user_timeout;
1898#else
1899 return 0;
1900#endif
1901}
1902
1903int
1905{
1906 if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
1907 return STATUS_OK;
1908
1909#ifdef TCP_USER_TIMEOUT
1910 if (timeout == port->tcp_user_timeout)
1911 return STATUS_OK;
1912
1913 if (port->default_tcp_user_timeout <= 0)
1914 {
1915 if (pq_gettcpusertimeout(port) < 0)
1916 {
1917 if (timeout == 0)
1918 return STATUS_OK; /* default is set but unknown */
1919 else
1920 return STATUS_ERROR;
1921 }
1922 }
1923
1924 if (timeout == 0)
1925 timeout = port->default_tcp_user_timeout;
1926
1927 if (setsockopt(port->sock, IPPROTO_TCP, TCP_USER_TIMEOUT,
1928 (char *) &timeout, sizeof(timeout)) < 0)
1929 {
1930 ereport(LOG,
1931 (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_USER_TIMEOUT")));
1932 return STATUS_ERROR;
1933 }
1934
1935 port->tcp_user_timeout = timeout;
1936#else
1937 if (timeout != 0)
1938 {
1939 ereport(LOG,
1940 (errmsg("%s(%s) not supported", "setsockopt", "TCP_USER_TIMEOUT")));
1941 return STATUS_ERROR;
1942 }
1943#endif
1944
1945 return STATUS_OK;
1946}
1947
1948/*
1949 * GUC assign_hook for tcp_keepalives_idle
1950 */
1951void
1953{
1954 /*
1955 * The kernel API provides no way to test a value without setting it; and
1956 * once we set it we might fail to unset it. So there seems little point
1957 * in fully implementing the check-then-assign GUC API for these
1958 * variables. Instead we just do the assignment on demand.
1959 * pq_setkeepalivesidle reports any problems via ereport(LOG).
1960 *
1961 * This approach means that the GUC value might have little to do with the
1962 * actual kernel value, so we use a show_hook that retrieves the kernel
1963 * value rather than trusting GUC's copy.
1964 */
1966}
1967
1968/*
1969 * GUC show_hook for tcp_keepalives_idle
1970 */
1971const char *
1973{
1974 /* See comments in assign_tcp_keepalives_idle */
1975 static char nbuf[16];
1976
1977 snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
1978 return nbuf;
1979}
1980
1981/*
1982 * GUC assign_hook for tcp_keepalives_interval
1983 */
1984void
1986{
1987 /* See comments in assign_tcp_keepalives_idle */
1989}
1990
1991/*
1992 * GUC show_hook for tcp_keepalives_interval
1993 */
1994const char *
1996{
1997 /* See comments in assign_tcp_keepalives_idle */
1998 static char nbuf[16];
1999
2000 snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
2001 return nbuf;
2002}
2003
2004/*
2005 * GUC assign_hook for tcp_keepalives_count
2006 */
2007void
2009{
2010 /* See comments in assign_tcp_keepalives_idle */
2012}
2013
2014/*
2015 * GUC show_hook for tcp_keepalives_count
2016 */
2017const char *
2019{
2020 /* See comments in assign_tcp_keepalives_idle */
2021 static char nbuf[16];
2022
2023 snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
2024 return nbuf;
2025}
2026
2027/*
2028 * GUC assign_hook for tcp_user_timeout
2029 */
2030void
2032{
2033 /* See comments in assign_tcp_keepalives_idle */
2035}
2036
2037/*
2038 * GUC show_hook for tcp_user_timeout
2039 */
2040const char *
2042{
2043 /* See comments in assign_tcp_keepalives_idle */
2044 static char nbuf[16];
2045
2046 snprintf(nbuf, sizeof(nbuf), "%d", pq_gettcpusertimeout(MyProcPort));
2047 return nbuf;
2048}
2049
2050/*
2051 * Check if the client is still connected.
2052 */
2053bool
2055{
2057 int rc;
2058
2059 /*
2060 * It's OK to modify the socket event filter without restoring, because
2061 * all FeBeWaitSet socket wait sites do the same.
2062 */
2064
2065retry:
2066 rc = WaitEventSetWait(FeBeWaitSet, 0, events, lengthof(events), 0);
2067 for (int i = 0; i < rc; ++i)
2068 {
2069 if (events[i].events & WL_SOCKET_CLOSED)
2070 return false;
2071 if (events[i].events & WL_LATCH_SET)
2072 {
2073 /*
2074 * A latch event might be preventing other events from being
2075 * reported. Reset it and poll again. No need to restore it
2076 * because no code should expect latches to survive across
2077 * CHECK_FOR_INTERRUPTS().
2078 */
2080 goto retry;
2081 }
2082 }
2083
2084 return true;
2085}
ssize_t secure_write(Port *port, void *ptr, size_t len)
Definition: be-secure.c:305
void secure_close(Port *port)
Definition: be-secure.c:167
ssize_t secure_read(Port *port, void *ptr, size_t len)
Definition: be-secure.c:179
#define pg_noinline
Definition: c.h:269
#define STATUS_OK
Definition: c.h:1123
#define PG_USED_FOR_ASSERTS_ONLY
Definition: c.h:201
#define Assert(condition)
Definition: c.h:812
int32_t int32
Definition: c.h:481
uint32_t uint32
Definition: c.h:485
#define lengthof(array)
Definition: c.h:742
#define MemSet(start, val, len)
Definition: c.h:974
#define STATUS_ERROR
Definition: c.h:1124
int errcode_for_socket_access(void)
Definition: elog.c:953
int errcode_for_file_access(void)
Definition: elog.c:876
int errhint(const char *fmt,...)
Definition: elog.c:1317
int errcode(int sqlerrcode)
Definition: elog.c:853
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define _(x)
Definition: elog.c:90
#define LOG
Definition: elog.h:31
#define PG_RE_THROW()
Definition: elog.h:412
#define COMMERROR
Definition: elog.h:33
#define FATAL
Definition: elog.h:41
#define PG_TRY(...)
Definition: elog.h:371
#define WARNING
Definition: elog.h:36
#define PG_END_TRY(...)
Definition: elog.h:396
#define ERROR
Definition: elog.h:39
#define PG_CATCH(...)
Definition: elog.h:381
#define elog(elevel,...)
Definition: elog.h:225
#define ereport(elevel,...)
Definition: elog.h:149
void err(int eval, const char *fmt,...)
Definition: err.c:43
volatile sig_atomic_t InterruptPending
Definition: globals.c:31
int MaxConnections
Definition: globals.c:142
volatile sig_atomic_t ClientConnectionLost
Definition: globals.c:35
struct Port * MyProcPort
Definition: globals.c:50
struct Latch * MyLatch
Definition: globals.c:62
#define newval
int tcp_keepalives_idle
Definition: guc_tables.c:545
int tcp_keepalives_interval
Definition: guc_tables.c:546
int tcp_keepalives_count
Definition: guc_tables.c:547
int tcp_user_timeout
Definition: guc_tables.c:548
return str start
long val
Definition: informix.c:689
void pg_freeaddrinfo_all(int hint_ai_family, struct addrinfo *ai)
Definition: ip.c:82
int pg_getnameinfo_all(const struct sockaddr_storage *addr, int salen, char *node, int nodelen, char *service, int servicelen, int flags)
Definition: ip.c:114
int pg_getaddrinfo_all(const char *hostname, const char *servname, const struct addrinfo *hintp, struct addrinfo **result)
Definition: ip.c:53
void on_proc_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:309
int i
Definition: isn.c:72
void ModifyWaitEvent(WaitEventSet *set, int pos, uint32 events, Latch *latch)
Definition: latch.c:1043
int AddWaitEventToSet(WaitEventSet *set, uint32 events, pgsocket fd, Latch *latch, void *user_data)
Definition: latch.c:957
int WaitEventSetWait(WaitEventSet *set, long timeout, WaitEvent *occurred_events, int nevents, uint32 wait_event_info)
Definition: latch.c:1418
WaitEventSet * CreateWaitEventSet(ResourceOwner resowner, int nevents)
Definition: latch.c:751
void ResetLatch(Latch *latch)
Definition: latch.c:724
#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
List * lappend(List *list, void *datum)
Definition: list.c:339
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:1181
char * pstrdup(const char *in)
Definition: mcxt.c:1696
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1541
void * palloc0(Size size)
Definition: mcxt.c:1347
MemoryContext TopMemoryContext
Definition: mcxt.c:149
void CreateSocketLockFile(const char *socketfile, bool amPostmaster, const char *socketDir)
Definition: miscinit.c:1520
void * arg
#define pg_ntoh32(x)
Definition: pg_bswap.h:125
#define pg_hton32(x)
Definition: pg_bswap.h:121
#define MAXPGPATH
const void size_t len
#define lfirst(lc)
Definition: pg_list.h:172
#define NIL
Definition: pg_list.h:68
static int port
Definition: pg_regress.c:115
static char * buf
Definition: pg_test_fsync.c:72
bool pg_set_noblock(pgsocket sock)
Definition: noblock.c:25
int pgsocket
Definition: port.h:29
#define snprintf
Definition: port.h:238
unsigned int socklen_t
Definition: port.h:40
#define PGINVALID_SOCKET
Definition: port.h:31
#define closesocket
Definition: port.h:349
uintptr_t Datum
Definition: postgres.h:64
static pgsocket * ListenSockets
Definition: postmaster.c:227
static int NumListenSockets
Definition: postmaster.c:226
static int PqRecvLength
Definition: pqcomm.c:129
int pq_setkeepalivesinterval(int interval, Port *port)
Definition: pqcomm.c:1750
Port * pq_init(ClientSocket *client_sock)
Definition: pqcomm.c:174
void assign_tcp_keepalives_count(int newval, void *extra)
Definition: pqcomm.c:2008
const PQcommMethods * PqCommMethods
Definition: pqcomm.c:164
static int pq_recvbuf(void)
Definition: pqcomm.c:898
const char * show_tcp_keepalives_interval(void)
Definition: pqcomm.c:1995
int Unix_socket_permissions
Definition: pqcomm.c:106
static int internal_flush(void)
Definition: pqcomm.c:1347
static void socket_set_nonblocking(bool nonblocking)
Definition: pqcomm.c:881
int pq_peekbyte(void)
Definition: pqcomm.c:983
static size_t PqSendPointer
Definition: pqcomm.c:124
const char * show_tcp_keepalives_count(void)
Definition: pqcomm.c:2018
int pq_getbyte_if_available(unsigned char *c)
Definition: pqcomm.c:1004
static int socket_flush_if_writable(void)
Definition: pqcomm.c:1433
int pq_getkeepalivescount(Port *port)
Definition: pqcomm.c:1799
#define PQ_RECV_BUFFER_SIZE
Definition: pqcomm.c:120
int pq_getkeepalivesinterval(Port *port)
Definition: pqcomm.c:1715
static int pq_discardbytes(size_t len)
Definition: pqcomm.c:1097
int pq_settcpusertimeout(int timeout, Port *port)
Definition: pqcomm.c:1904
int pq_getmessage(StringInfo s, int maxlen)
Definition: pqcomm.c:1203
static const PQcommMethods PqCommSocketMethods
Definition: pqcomm.c:155
int pq_getbytes(char *s, size_t len)
Definition: pqcomm.c:1063
static bool PqCommReadingMsg
Definition: pqcomm.c:135
char * Unix_socket_group
Definition: pqcomm.c:107
static int socket_flush(void)
Definition: pqcomm.c:1325
ssize_t pq_buffer_remaining_data(void)
Definition: pqcomm.c:1127
#define PQ_SEND_BUFFER_SIZE
Definition: pqcomm.c:119
const char * show_tcp_keepalives_idle(void)
Definition: pqcomm.c:1972
int pq_setkeepalivesidle(int idle, Port *port)
Definition: pqcomm.c:1665
int ListenServerPort(int family, const char *hostName, unsigned short portNumber, const char *unixSocketDir, pgsocket ListenSockets[], int *NumListenSockets, int MaxListen)
Definition: pqcomm.c:418
static void socket_comm_reset(void)
Definition: pqcomm.c:334
WaitEventSet * FeBeWaitSet
Definition: pqcomm.c:166
static char * PqSendBuffer
Definition: pqcomm.c:122
static int Lock_AF_UNIX(const char *unixSocketDir, const char *unixSocketPath)
Definition: pqcomm.c:685
int pq_getkeepalivesidle(Port *port)
Definition: pqcomm.c:1630
void pq_endmsgread(void)
Definition: pqcomm.c:1165
static List * sock_paths
Definition: pqcomm.c:110
int AcceptConnection(pgsocket server_fd, ClientSocket *client_sock)
Definition: pqcomm.c:794
void TouchSocketFiles(void)
Definition: pqcomm.c:830
static bool PqCommBusy
Definition: pqcomm.c:134
int pq_getbyte(void)
Definition: pqcomm.c:964
static bool socket_is_send_pending(void)
Definition: pqcomm.c:1459
void assign_tcp_keepalives_idle(int newval, void *extra)
Definition: pqcomm.c:1952
static int socket_putmessage(char msgtype, const char *s, size_t len)
Definition: pqcomm.c:1489
static void socket_putmessage_noblock(char msgtype, const char *s, size_t len)
Definition: pqcomm.c:1522
static char PqRecvBuffer[PQ_RECV_BUFFER_SIZE]
Definition: pqcomm.c:127
static int PqRecvPointer
Definition: pqcomm.c:128
const char * show_tcp_user_timeout(void)
Definition: pqcomm.c:2041
static void socket_close(int code, Datum arg)
Definition: pqcomm.c:349
void assign_tcp_user_timeout(int newval, void *extra)
Definition: pqcomm.c:2031
int pq_putmessage_v2(char msgtype, const char *s, size_t len)
Definition: pqcomm.c:1559
static int Setup_AF_UNIX(const char *sock_path)
Definition: pqcomm.c:720
bool pq_is_reading_msg(void)
Definition: pqcomm.c:1181
void RemoveSocketFiles(void)
Definition: pqcomm.c:848
int pq_gettcpusertimeout(Port *port)
Definition: pqcomm.c:1874
bool pq_check_connection(void)
Definition: pqcomm.c:2054
static int PqSendBufferSize
Definition: pqcomm.c:123
void assign_tcp_keepalives_interval(int newval, void *extra)
Definition: pqcomm.c:1985
void pq_startmsgread(void)
Definition: pqcomm.c:1141
int pq_setkeepalivescount(int count, Port *port)
Definition: pqcomm.c:1829
static pg_noinline int internal_flush_buffer(const char *buf, size_t *start, size_t *end)
Definition: pqcomm.c:1360
static size_t PqSendStart
Definition: pqcomm.c:125
static int internal_putbytes(const char *s, size_t len)
Definition: pqcomm.c:1277
#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
static pg_noinline void Size size
Definition: slab.c:607
const char * gai_strerror(int ecode)
void resetStringInfo(StringInfo str)
Definition: stringinfo.c:75
void enlargeStringInfo(StringInfo str, int needed)
Definition: stringinfo.c:286
SockAddr raddr
Definition: libpq-be.h:245
pgsocket sock
Definition: libpq-be.h:244
Definition: pg_list.h:54
void(* comm_reset)(void)
Definition: libpq.h:35
Definition: libpq-be.h:133
void * gss
Definition: libpq-be.h:196
pgsocket sock
Definition: libpq-be.h:134
bool noblock
Definition: libpq-be.h:135
struct sockaddr_storage addr
Definition: pqcomm.h:32
socklen_t salen
Definition: pqcomm.h:33
#define bind(s, addr, addrlen)
Definition: win32_port.h:509
#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:508
#define accept(s, addr, addrlen)
Definition: win32_port.h:511
#define listen(s, backlog)
Definition: win32_port.h:510
#define EAGAIN
Definition: win32_port.h:372