LCOV - code coverage report
Current view: top level - src/backend/libpq - pqcomm.c (source / functions) Hit Total Coverage
Test: PostgreSQL 13devel Lines: 301 514 58.6 %
Date: 2019-09-19 02:07:14 Functions: 34 40 85.0 %
Legend: Lines: hit not hit

          Line data    Source code
       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 --- or would be,
       9             :  * except for major brain damage in the design of the old COPY OUT protocol.
      10             :  * Unfortunately, COPY OUT was designed to commandeer the communication
      11             :  * channel (it just transfers data without wrapping it into messages).
      12             :  * No other messages can be sent while COPY OUT is in progress; and if the
      13             :  * copy is aborted by an ereport(ERROR), we need to close out the copy so that
      14             :  * the frontend gets back into sync.  Therefore, these routines have to be
      15             :  * aware of COPY OUT state.  (New COPY-OUT is message-based and does *not*
      16             :  * set the DoingCopyOut flag.)
      17             :  *
      18             :  * NOTE: generally, it's a bad idea to emit outgoing messages directly with
      19             :  * pq_putbytes(), especially if the message would require multiple calls
      20             :  * to send.  Instead, use the routines in pqformat.c to construct the message
      21             :  * in a buffer and then emit it in one call to pq_putmessage.  This ensures
      22             :  * that the channel will not be clogged by an incomplete message if execution
      23             :  * is aborted by ereport(ERROR) partway through the message.  The only
      24             :  * non-libpq code that should call pq_putbytes directly is old-style COPY OUT.
      25             :  *
      26             :  * At one time, libpq was shared between frontend and backend, but now
      27             :  * the backend's "backend/libpq" is quite separate from "interfaces/libpq".
      28             :  * All that remains is similarities of names to trap the unwary...
      29             :  *
      30             :  * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
      31             :  * Portions Copyright (c) 1994, Regents of the University of California
      32             :  *
      33             :  *  src/backend/libpq/pqcomm.c
      34             :  *
      35             :  *-------------------------------------------------------------------------
      36             :  */
      37             : 
      38             : /*------------------------
      39             :  * INTERFACE ROUTINES
      40             :  *
      41             :  * setup/teardown:
      42             :  *      StreamServerPort    - Open postmaster's server port
      43             :  *      StreamConnection    - Create new connection with client
      44             :  *      StreamClose         - Close a client/backend connection
      45             :  *      TouchSocketFiles    - Protect socket files against /tmp cleaners
      46             :  *      pq_init         - initialize libpq at backend startup
      47             :  *      socket_comm_reset   - reset libpq during error recovery
      48             :  *      socket_close        - shutdown libpq at backend exit
      49             :  *
      50             :  * low-level I/O:
      51             :  *      pq_getbytes     - get a known number of bytes from connection
      52             :  *      pq_getstring    - get a null terminated string from connection
      53             :  *      pq_getmessage   - get a message with length word from connection
      54             :  *      pq_getbyte      - get next byte from connection
      55             :  *      pq_peekbyte     - peek at next byte from connection
      56             :  *      pq_putbytes     - send bytes to connection (not flushed until pq_flush)
      57             :  *      pq_flush        - flush pending output
      58             :  *      pq_flush_if_writable - flush pending output if writable without blocking
      59             :  *      pq_getbyte_if_available - get a byte if available without blocking
      60             :  *
      61             :  * message-level I/O (and old-style-COPY-OUT cruft):
      62             :  *      pq_putmessage   - send a normal message (suppressed in COPY OUT mode)
      63             :  *      pq_putmessage_noblock - buffer a normal message (suppressed in COPY OUT)
      64             :  *      pq_startcopyout - inform libpq that a COPY OUT transfer is beginning
      65             :  *      pq_endcopyout   - end a COPY OUT transfer
      66             :  *
      67             :  *------------------------
      68             :  */
      69             : #include "postgres.h"
      70             : 
      71             : #include <signal.h>
      72             : #include <fcntl.h>
      73             : #include <grp.h>
      74             : #include <unistd.h>
      75             : #include <sys/file.h>
      76             : #include <sys/socket.h>
      77             : #include <sys/stat.h>
      78             : #include <sys/time.h>
      79             : #include <netdb.h>
      80             : #include <netinet/in.h>
      81             : #ifdef HAVE_NETINET_TCP_H
      82             : #include <netinet/tcp.h>
      83             : #endif
      84             : #ifdef HAVE_UTIME_H
      85             : #include <utime.h>
      86             : #endif
      87             : #ifdef _MSC_VER                 /* mstcpip.h is missing on mingw */
      88             : #include <mstcpip.h>
      89             : #endif
      90             : 
      91             : #include "common/ip.h"
      92             : #include "libpq/libpq.h"
      93             : #include "miscadmin.h"
      94             : #include "port/pg_bswap.h"
      95             : #include "storage/ipc.h"
      96             : #include "utils/guc.h"
      97             : #include "utils/memutils.h"
      98             : 
      99             : /*
     100             :  * Cope with the various platform-specific ways to spell TCP keepalive socket
     101             :  * options.  This doesn't cover Windows, which as usual does its own thing.
     102             :  */
     103             : #if defined(TCP_KEEPIDLE)
     104             : /* TCP_KEEPIDLE is the name of this option on Linux and *BSD */
     105             : #define PG_TCP_KEEPALIVE_IDLE TCP_KEEPIDLE
     106             : #define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPIDLE"
     107             : #elif defined(TCP_KEEPALIVE_THRESHOLD)
     108             : /* TCP_KEEPALIVE_THRESHOLD is the name of this option on Solaris >= 11 */
     109             : #define PG_TCP_KEEPALIVE_IDLE TCP_KEEPALIVE_THRESHOLD
     110             : #define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPALIVE_THRESHOLD"
     111             : #elif defined(TCP_KEEPALIVE) && defined(__darwin__)
     112             : /* TCP_KEEPALIVE is the name of this option on macOS */
     113             : /* Caution: Solaris has this symbol but it means something different */
     114             : #define PG_TCP_KEEPALIVE_IDLE TCP_KEEPALIVE
     115             : #define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPALIVE"
     116             : #endif
     117             : 
     118             : /*
     119             :  * Configuration options
     120             :  */
     121             : int         Unix_socket_permissions;
     122             : char       *Unix_socket_group;
     123             : 
     124             : /* Where the Unix socket files are (list of palloc'd strings) */
     125             : static List *sock_paths = NIL;
     126             : 
     127             : /*
     128             :  * Buffers for low-level I/O.
     129             :  *
     130             :  * The receive buffer is fixed size. Send buffer is usually 8k, but can be
     131             :  * enlarged by pq_putmessage_noblock() if the message doesn't fit otherwise.
     132             :  */
     133             : 
     134             : #define PQ_SEND_BUFFER_SIZE 8192
     135             : #define PQ_RECV_BUFFER_SIZE 8192
     136             : 
     137             : static char *PqSendBuffer;
     138             : static int  PqSendBufferSize;   /* Size send buffer */
     139             : static int  PqSendPointer;      /* Next index to store a byte in PqSendBuffer */
     140             : static int  PqSendStart;        /* Next index to send a byte in PqSendBuffer */
     141             : 
     142             : static char PqRecvBuffer[PQ_RECV_BUFFER_SIZE];
     143             : static int  PqRecvPointer;      /* Next index to read a byte from PqRecvBuffer */
     144             : static int  PqRecvLength;       /* End of data available in PqRecvBuffer */
     145             : 
     146             : /*
     147             :  * Message status
     148             :  */
     149             : static bool PqCommBusy;         /* busy sending data to the client */
     150             : static bool PqCommReadingMsg;   /* in the middle of reading a message */
     151             : static bool DoingCopyOut;       /* in old-protocol COPY OUT processing */
     152             : 
     153             : 
     154             : /* Internal functions */
     155             : static void socket_comm_reset(void);
     156             : static void socket_close(int code, Datum arg);
     157             : static void socket_set_nonblocking(bool nonblocking);
     158             : static int  socket_flush(void);
     159             : static int  socket_flush_if_writable(void);
     160             : static bool socket_is_send_pending(void);
     161             : static int  socket_putmessage(char msgtype, const char *s, size_t len);
     162             : static void socket_putmessage_noblock(char msgtype, const char *s, size_t len);
     163             : static void socket_startcopyout(void);
     164             : static void socket_endcopyout(bool errorAbort);
     165             : static int  internal_putbytes(const char *s, size_t len);
     166             : static int  internal_flush(void);
     167             : 
     168             : #ifdef HAVE_UNIX_SOCKETS
     169             : static int  Lock_AF_UNIX(char *unixSocketDir, char *unixSocketPath);
     170             : static int  Setup_AF_UNIX(char *sock_path);
     171             : #endif                          /* HAVE_UNIX_SOCKETS */
     172             : 
     173             : static const PQcommMethods PqCommSocketMethods = {
     174             :     socket_comm_reset,
     175             :     socket_flush,
     176             :     socket_flush_if_writable,
     177             :     socket_is_send_pending,
     178             :     socket_putmessage,
     179             :     socket_putmessage_noblock,
     180             :     socket_startcopyout,
     181             :     socket_endcopyout
     182             : };
     183             : 
     184             : const PQcommMethods *PqCommMethods = &PqCommSocketMethods;
     185             : 
     186             : WaitEventSet *FeBeWaitSet;
     187             : 
     188             : 
     189             : /* --------------------------------
     190             :  *      pq_init - initialize libpq at backend startup
     191             :  * --------------------------------
     192             :  */
     193             : void
     194        6790 : pq_init(void)
     195             : {
     196             :     /* initialize state variables */
     197        6790 :     PqSendBufferSize = PQ_SEND_BUFFER_SIZE;
     198        6790 :     PqSendBuffer = MemoryContextAlloc(TopMemoryContext, PqSendBufferSize);
     199        6790 :     PqSendPointer = PqSendStart = PqRecvPointer = PqRecvLength = 0;
     200        6790 :     PqCommBusy = false;
     201        6790 :     PqCommReadingMsg = false;
     202        6790 :     DoingCopyOut = false;
     203             : 
     204             :     /* set up process-exit hook to close the socket */
     205        6790 :     on_proc_exit(socket_close, 0);
     206             : 
     207             :     /*
     208             :      * In backends (as soon as forked) we operate the underlying socket in
     209             :      * nonblocking mode and use latches to implement blocking semantics if
     210             :      * needed. That allows us to provide safely interruptible reads and
     211             :      * writes.
     212             :      *
     213             :      * Use COMMERROR on failure, because ERROR would try to send the error to
     214             :      * the client, which might require changing the mode again, leading to
     215             :      * infinite recursion.
     216             :      */
     217             : #ifndef WIN32
     218        6790 :     if (!pg_set_noblock(MyProcPort->sock))
     219           0 :         ereport(COMMERROR,
     220             :                 (errmsg("could not set socket to nonblocking mode: %m")));
     221             : #endif
     222             : 
     223        6790 :     FeBeWaitSet = CreateWaitEventSet(TopMemoryContext, 3);
     224        6790 :     AddWaitEventToSet(FeBeWaitSet, WL_SOCKET_WRITEABLE, MyProcPort->sock,
     225             :                       NULL, NULL);
     226        6790 :     AddWaitEventToSet(FeBeWaitSet, WL_LATCH_SET, -1, MyLatch, NULL);
     227        6790 :     AddWaitEventToSet(FeBeWaitSet, WL_POSTMASTER_DEATH, -1, NULL, NULL);
     228        6790 : }
     229             : 
     230             : /* --------------------------------
     231             :  *      socket_comm_reset - reset libpq during error recovery
     232             :  *
     233             :  * This is called from error recovery at the outer idle loop.  It's
     234             :  * just to get us out of trouble if we somehow manage to elog() from
     235             :  * inside a pqcomm.c routine (which ideally will never happen, but...)
     236             :  * --------------------------------
     237             :  */
     238             : static void
     239       17894 : socket_comm_reset(void)
     240             : {
     241             :     /* Do not throw away pending data, but do reset the busy flag */
     242       17894 :     PqCommBusy = false;
     243             :     /* We can abort any old-style COPY OUT, too */
     244       17894 :     pq_endcopyout(true);
     245       17894 : }
     246             : 
     247             : /* --------------------------------
     248             :  *      socket_close - shutdown libpq at backend exit
     249             :  *
     250             :  * This is the one pg_on_exit_callback in place during BackendInitialize().
     251             :  * That function's unusual signal handling constrains that this callback be
     252             :  * safe to run at any instant.
     253             :  * --------------------------------
     254             :  */
     255             : static void
     256        6790 : socket_close(int code, Datum arg)
     257             : {
     258             :     /* Nothing to do in a standalone backend, where MyProcPort is NULL. */
     259        6790 :     if (MyProcPort != NULL)
     260             :     {
     261             : #if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
     262             : #ifdef ENABLE_GSS
     263             :         OM_uint32   min_s;
     264             : 
     265             :         /*
     266             :          * Shutdown GSSAPI layer.  This section does nothing when interrupting
     267             :          * BackendInitialize(), because pg_GSS_recvauth() makes first use of
     268             :          * "ctx" and "cred".
     269             :          */
     270             :         if (MyProcPort->gss->ctx != GSS_C_NO_CONTEXT)
     271             :             gss_delete_sec_context(&min_s, &MyProcPort->gss->ctx, NULL);
     272             : 
     273             :         if (MyProcPort->gss->cred != GSS_C_NO_CREDENTIAL)
     274             :             gss_release_cred(&min_s, &MyProcPort->gss->cred);
     275             : #endif                          /* ENABLE_GSS */
     276             : 
     277             :         /*
     278             :          * GSS and SSPI share the port->gss struct.  Since nowhere else does a
     279             :          * postmaster child free this, doing so is safe when interrupting
     280             :          * BackendInitialize().
     281             :          */
     282             :         free(MyProcPort->gss);
     283             : #endif                          /* ENABLE_GSS || ENABLE_SSPI */
     284             : 
     285             :         /*
     286             :          * Cleanly shut down SSL layer.  Nowhere else does a postmaster child
     287             :          * call this, so this is safe when interrupting BackendInitialize().
     288             :          */
     289        6790 :         secure_close(MyProcPort);
     290             : 
     291             :         /*
     292             :          * Formerly we did an explicit close() here, but it seems better to
     293             :          * leave the socket open until the process dies.  This allows clients
     294             :          * to perform a "synchronous close" if they care --- wait till the
     295             :          * transport layer reports connection closure, and you can be sure the
     296             :          * backend has exited.
     297             :          *
     298             :          * We do set sock to PGINVALID_SOCKET to prevent any further I/O,
     299             :          * though.
     300             :          */
     301        6790 :         MyProcPort->sock = PGINVALID_SOCKET;
     302             :     }
     303        6790 : }
     304             : 
     305             : 
     306             : 
     307             : /*
     308             :  * Streams -- wrapper around Unix socket system calls
     309             :  *
     310             :  *
     311             :  *      Stream functions are used for vanilla TCP connection protocol.
     312             :  */
     313             : 
     314             : 
     315             : /*
     316             :  * StreamServerPort -- open a "listening" port to accept connections.
     317             :  *
     318             :  * family should be AF_UNIX or AF_UNSPEC; portNumber is the port number.
     319             :  * For AF_UNIX ports, hostName should be NULL and unixSocketDir must be
     320             :  * specified.  For TCP ports, hostName is either NULL for all interfaces or
     321             :  * the interface to listen on, and unixSocketDir is ignored (can be NULL).
     322             :  *
     323             :  * Successfully opened sockets are added to the ListenSocket[] array (of
     324             :  * length MaxListen), at the first position that isn't PGINVALID_SOCKET.
     325             :  *
     326             :  * RETURNS: STATUS_OK or STATUS_ERROR
     327             :  */
     328             : 
     329             : int
     330         594 : StreamServerPort(int family, char *hostName, unsigned short portNumber,
     331             :                  char *unixSocketDir,
     332             :                  pgsocket ListenSocket[], int MaxListen)
     333             : {
     334             :     pgsocket    fd;
     335             :     int         err;
     336             :     int         maxconn;
     337             :     int         ret;
     338             :     char        portNumberStr[32];
     339             :     const char *familyDesc;
     340             :     char        familyDescBuf[64];
     341             :     const char *addrDesc;
     342             :     char        addrBuf[NI_MAXHOST];
     343             :     char       *service;
     344         594 :     struct addrinfo *addrs = NULL,
     345             :                *addr;
     346             :     struct addrinfo hint;
     347         594 :     int         listen_index = 0;
     348         594 :     int         added = 0;
     349             : 
     350             : #ifdef HAVE_UNIX_SOCKETS
     351             :     char        unixSocketPath[MAXPGPATH];
     352             : #endif
     353             : #if !defined(WIN32) || defined(IPV6_V6ONLY)
     354         594 :     int         one = 1;
     355             : #endif
     356             : 
     357             :     /* Initialize hint structure */
     358         594 :     MemSet(&hint, 0, sizeof(hint));
     359         594 :     hint.ai_family = family;
     360         594 :     hint.ai_flags = AI_PASSIVE;
     361         594 :     hint.ai_socktype = SOCK_STREAM;
     362             : 
     363             : #ifdef HAVE_UNIX_SOCKETS
     364         594 :     if (family == AF_UNIX)
     365             :     {
     366             :         /*
     367             :          * Create unixSocketPath from portNumber and unixSocketDir and lock
     368             :          * that file path
     369             :          */
     370         570 :         UNIXSOCK_PATH(unixSocketPath, portNumber, unixSocketDir);
     371         570 :         if (strlen(unixSocketPath) >= UNIXSOCK_PATH_BUFLEN)
     372             :         {
     373           0 :             ereport(LOG,
     374             :                     (errmsg("Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
     375             :                             unixSocketPath,
     376             :                             (int) (UNIXSOCK_PATH_BUFLEN - 1))));
     377           0 :             return STATUS_ERROR;
     378             :         }
     379         570 :         if (Lock_AF_UNIX(unixSocketDir, unixSocketPath) != STATUS_OK)
     380           0 :             return STATUS_ERROR;
     381         570 :         service = unixSocketPath;
     382             :     }
     383             :     else
     384             : #endif                          /* HAVE_UNIX_SOCKETS */
     385             :     {
     386          24 :         snprintf(portNumberStr, sizeof(portNumberStr), "%d", portNumber);
     387          24 :         service = portNumberStr;
     388             :     }
     389             : 
     390         594 :     ret = pg_getaddrinfo_all(hostName, service, &hint, &addrs);
     391         594 :     if (ret || !addrs)
     392             :     {
     393           0 :         if (hostName)
     394           0 :             ereport(LOG,
     395             :                     (errmsg("could not translate host name \"%s\", service \"%s\" to address: %s",
     396             :                             hostName, service, gai_strerror(ret))));
     397             :         else
     398           0 :             ereport(LOG,
     399             :                     (errmsg("could not translate service \"%s\" to address: %s",
     400             :                             service, gai_strerror(ret))));
     401           0 :         if (addrs)
     402           0 :             pg_freeaddrinfo_all(hint.ai_family, addrs);
     403           0 :         return STATUS_ERROR;
     404             :     }
     405             : 
     406        1190 :     for (addr = addrs; addr; addr = addr->ai_next)
     407             :     {
     408         596 :         if (!IS_AF_UNIX(family) && IS_AF_UNIX(addr->ai_family))
     409             :         {
     410             :             /*
     411             :              * Only set up a unix domain socket when they really asked for it.
     412             :              * The service/port is different in that case.
     413             :              */
     414           0 :             continue;
     415             :         }
     416             : 
     417             :         /* See if there is still room to add 1 more socket. */
     418         620 :         for (; listen_index < MaxListen; listen_index++)
     419             :         {
     420         620 :             if (ListenSocket[listen_index] == PGINVALID_SOCKET)
     421         596 :                 break;
     422             :         }
     423         596 :         if (listen_index >= MaxListen)
     424             :         {
     425           0 :             ereport(LOG,
     426             :                     (errmsg("could not bind to all requested addresses: MAXLISTEN (%d) exceeded",
     427             :                             MaxListen)));
     428           0 :             break;
     429             :         }
     430             : 
     431             :         /* set up address family name for log messages */
     432         596 :         switch (addr->ai_family)
     433             :         {
     434             :             case AF_INET:
     435          24 :                 familyDesc = _("IPv4");
     436          24 :                 break;
     437             : #ifdef HAVE_IPV6
     438             :             case AF_INET6:
     439           2 :                 familyDesc = _("IPv6");
     440           2 :                 break;
     441             : #endif
     442             : #ifdef HAVE_UNIX_SOCKETS
     443             :             case AF_UNIX:
     444         570 :                 familyDesc = _("Unix");
     445         570 :                 break;
     446             : #endif
     447             :             default:
     448           0 :                 snprintf(familyDescBuf, sizeof(familyDescBuf),
     449           0 :                          _("unrecognized address family %d"),
     450             :                          addr->ai_family);
     451           0 :                 familyDesc = familyDescBuf;
     452           0 :                 break;
     453             :         }
     454             : 
     455             :         /* set up text form of address for log messages */
     456             : #ifdef HAVE_UNIX_SOCKETS
     457         596 :         if (addr->ai_family == AF_UNIX)
     458         570 :             addrDesc = unixSocketPath;
     459             :         else
     460             : #endif
     461             :         {
     462          26 :             pg_getnameinfo_all((const struct sockaddr_storage *) addr->ai_addr,
     463          26 :                                addr->ai_addrlen,
     464             :                                addrBuf, sizeof(addrBuf),
     465             :                                NULL, 0,
     466             :                                NI_NUMERICHOST);
     467          26 :             addrDesc = addrBuf;
     468             :         }
     469             : 
     470         596 :         if ((fd = socket(addr->ai_family, SOCK_STREAM, 0)) == PGINVALID_SOCKET)
     471             :         {
     472           0 :             ereport(LOG,
     473             :                     (errcode_for_socket_access(),
     474             :             /* translator: first %s is IPv4, IPv6, or Unix */
     475             :                      errmsg("could not create %s socket for address \"%s\": %m",
     476             :                             familyDesc, addrDesc)));
     477           0 :             continue;
     478             :         }
     479             : 
     480             : #ifndef WIN32
     481             : 
     482             :         /*
     483             :          * Without the SO_REUSEADDR flag, a new postmaster can't be started
     484             :          * right away after a stop or crash, giving "address already in use"
     485             :          * error on TCP ports.
     486             :          *
     487             :          * On win32, however, this behavior only happens if the
     488             :          * SO_EXCLUSIVEADDRUSE is set. With SO_REUSEADDR, win32 allows
     489             :          * multiple servers to listen on the same address, resulting in
     490             :          * unpredictable behavior. With no flags at all, win32 behaves as Unix
     491             :          * with SO_REUSEADDR.
     492             :          */
     493         596 :         if (!IS_AF_UNIX(addr->ai_family))
     494             :         {
     495          26 :             if ((setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
     496             :                             (char *) &one, sizeof(one))) == -1)
     497             :             {
     498           0 :                 ereport(LOG,
     499             :                         (errcode_for_socket_access(),
     500             :                 /* translator: first %s is IPv4, IPv6, or Unix */
     501             :                          errmsg("setsockopt(SO_REUSEADDR) failed for %s address \"%s\": %m",
     502             :                                 familyDesc, addrDesc)));
     503           0 :                 closesocket(fd);
     504           0 :                 continue;
     505             :             }
     506             :         }
     507             : #endif
     508             : 
     509             : #ifdef IPV6_V6ONLY
     510         596 :         if (addr->ai_family == AF_INET6)
     511             :         {
     512           2 :             if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
     513             :                            (char *) &one, sizeof(one)) == -1)
     514             :             {
     515           0 :                 ereport(LOG,
     516             :                         (errcode_for_socket_access(),
     517             :                 /* translator: first %s is IPv4, IPv6, or Unix */
     518             :                          errmsg("setsockopt(IPV6_V6ONLY) failed for %s address \"%s\": %m",
     519             :                                 familyDesc, addrDesc)));
     520           0 :                 closesocket(fd);
     521           0 :                 continue;
     522             :             }
     523             :         }
     524             : #endif
     525             : 
     526             :         /*
     527             :          * Note: This might fail on some OS's, like Linux older than
     528             :          * 2.4.21-pre3, that don't have the IPV6_V6ONLY socket option, and map
     529             :          * ipv4 addresses to ipv6.  It will show ::ffff:ipv4 for all ipv4
     530             :          * connections.
     531             :          */
     532         596 :         err = bind(fd, addr->ai_addr, addr->ai_addrlen);
     533         596 :         if (err < 0)
     534             :         {
     535           0 :             ereport(LOG,
     536             :                     (errcode_for_socket_access(),
     537             :             /* translator: first %s is IPv4, IPv6, or Unix */
     538             :                      errmsg("could not bind %s address \"%s\": %m",
     539             :                             familyDesc, addrDesc),
     540             :                      (IS_AF_UNIX(addr->ai_family)) ?
     541             :                      errhint("Is another postmaster already running on port %d?"
     542             :                              " If not, remove socket file \"%s\" and retry.",
     543             :                              (int) portNumber, service) :
     544             :                      errhint("Is another postmaster already running on port %d?"
     545             :                              " If not, wait a few seconds and retry.",
     546             :                              (int) portNumber)));
     547           0 :             closesocket(fd);
     548           0 :             continue;
     549             :         }
     550             : 
     551             : #ifdef HAVE_UNIX_SOCKETS
     552         596 :         if (addr->ai_family == AF_UNIX)
     553             :         {
     554         570 :             if (Setup_AF_UNIX(service) != STATUS_OK)
     555             :             {
     556           0 :                 closesocket(fd);
     557           0 :                 break;
     558             :             }
     559             :         }
     560             : #endif
     561             : 
     562             :         /*
     563             :          * Select appropriate accept-queue length limit.  PG_SOMAXCONN is only
     564             :          * intended to provide a clamp on the request on platforms where an
     565             :          * overly large request provokes a kernel error (are there any?).
     566             :          */
     567         596 :         maxconn = MaxBackends * 2;
     568         596 :         if (maxconn > PG_SOMAXCONN)
     569           0 :             maxconn = PG_SOMAXCONN;
     570             : 
     571         596 :         err = listen(fd, maxconn);
     572         596 :         if (err < 0)
     573             :         {
     574           0 :             ereport(LOG,
     575             :                     (errcode_for_socket_access(),
     576             :             /* translator: first %s is IPv4, IPv6, or Unix */
     577             :                      errmsg("could not listen on %s address \"%s\": %m",
     578             :                             familyDesc, addrDesc)));
     579           0 :             closesocket(fd);
     580           0 :             continue;
     581             :         }
     582             : 
     583             : #ifdef HAVE_UNIX_SOCKETS
     584         596 :         if (addr->ai_family == AF_UNIX)
     585         570 :             ereport(LOG,
     586             :                     (errmsg("listening on Unix socket \"%s\"",
     587             :                             addrDesc)));
     588             :         else
     589             : #endif
     590          26 :             ereport(LOG,
     591             :             /* translator: first %s is IPv4 or IPv6 */
     592             :                     (errmsg("listening on %s address \"%s\", port %d",
     593             :                             familyDesc, addrDesc, (int) portNumber)));
     594             : 
     595         596 :         ListenSocket[listen_index] = fd;
     596         596 :         added++;
     597             :     }
     598             : 
     599         594 :     pg_freeaddrinfo_all(hint.ai_family, addrs);
     600             : 
     601         594 :     if (!added)
     602           0 :         return STATUS_ERROR;
     603             : 
     604         594 :     return STATUS_OK;
     605             : }
     606             : 
     607             : 
     608             : #ifdef HAVE_UNIX_SOCKETS
     609             : 
     610             : /*
     611             :  * Lock_AF_UNIX -- configure unix socket file path
     612             :  */
     613             : static int
     614         570 : Lock_AF_UNIX(char *unixSocketDir, char *unixSocketPath)
     615             : {
     616             :     /*
     617             :      * Grab an interlock file associated with the socket file.
     618             :      *
     619             :      * Note: there are two reasons for using a socket lock file, rather than
     620             :      * trying to interlock directly on the socket itself.  First, it's a lot
     621             :      * more portable, and second, it lets us remove any pre-existing socket
     622             :      * file without race conditions.
     623             :      */
     624         570 :     CreateSocketLockFile(unixSocketPath, true, unixSocketDir);
     625             : 
     626             :     /*
     627             :      * Once we have the interlock, we can safely delete any pre-existing
     628             :      * socket file to avoid failure at bind() time.
     629             :      */
     630         570 :     (void) unlink(unixSocketPath);
     631             : 
     632             :     /*
     633             :      * Remember socket file pathnames for later maintenance.
     634             :      */
     635         570 :     sock_paths = lappend(sock_paths, pstrdup(unixSocketPath));
     636             : 
     637         570 :     return STATUS_OK;
     638             : }
     639             : 
     640             : 
     641             : /*
     642             :  * Setup_AF_UNIX -- configure unix socket permissions
     643             :  */
     644             : static int
     645         570 : Setup_AF_UNIX(char *sock_path)
     646             : {
     647             :     /*
     648             :      * Fix socket ownership/permission if requested.  Note we must do this
     649             :      * before we listen() to avoid a window where unwanted connections could
     650             :      * get accepted.
     651             :      */
     652             :     Assert(Unix_socket_group);
     653         570 :     if (Unix_socket_group[0] != '\0')
     654             :     {
     655             : #ifdef WIN32
     656             :         elog(WARNING, "configuration item unix_socket_group is not supported on this platform");
     657             : #else
     658             :         char       *endptr;
     659             :         unsigned long val;
     660             :         gid_t       gid;
     661             : 
     662           0 :         val = strtoul(Unix_socket_group, &endptr, 10);
     663           0 :         if (*endptr == '\0')
     664             :         {                       /* numeric group id */
     665           0 :             gid = val;
     666             :         }
     667             :         else
     668             :         {                       /* convert group name to id */
     669             :             struct group *gr;
     670             : 
     671           0 :             gr = getgrnam(Unix_socket_group);
     672           0 :             if (!gr)
     673             :             {
     674           0 :                 ereport(LOG,
     675             :                         (errmsg("group \"%s\" does not exist",
     676             :                                 Unix_socket_group)));
     677           0 :                 return STATUS_ERROR;
     678             :             }
     679           0 :             gid = gr->gr_gid;
     680             :         }
     681           0 :         if (chown(sock_path, -1, gid) == -1)
     682             :         {
     683           0 :             ereport(LOG,
     684             :                     (errcode_for_file_access(),
     685             :                      errmsg("could not set group of file \"%s\": %m",
     686             :                             sock_path)));
     687           0 :             return STATUS_ERROR;
     688             :         }
     689             : #endif
     690             :     }
     691             : 
     692         570 :     if (chmod(sock_path, Unix_socket_permissions) == -1)
     693             :     {
     694           0 :         ereport(LOG,
     695             :                 (errcode_for_file_access(),
     696             :                  errmsg("could not set permissions of file \"%s\": %m",
     697             :                         sock_path)));
     698           0 :         return STATUS_ERROR;
     699             :     }
     700         570 :     return STATUS_OK;
     701             : }
     702             : #endif                          /* HAVE_UNIX_SOCKETS */
     703             : 
     704             : 
     705             : /*
     706             :  * StreamConnection -- create a new connection with client using
     707             :  *      server port.  Set port->sock to the FD of the new connection.
     708             :  *
     709             :  * ASSUME: that this doesn't need to be non-blocking because
     710             :  *      the Postmaster uses select() to tell when the server master
     711             :  *      socket is ready for accept().
     712             :  *
     713             :  * RETURNS: STATUS_OK or STATUS_ERROR
     714             :  */
     715             : int
     716        6906 : StreamConnection(pgsocket server_fd, Port *port)
     717             : {
     718             :     /* accept connection and fill in the client (remote) address */
     719        6906 :     port->raddr.salen = sizeof(port->raddr.addr);
     720       13812 :     if ((port->sock = accept(server_fd,
     721        6906 :                              (struct sockaddr *) &port->raddr.addr,
     722             :                              &port->raddr.salen)) == PGINVALID_SOCKET)
     723             :     {
     724           0 :         ereport(LOG,
     725             :                 (errcode_for_socket_access(),
     726             :                  errmsg("could not accept new connection: %m")));
     727             : 
     728             :         /*
     729             :          * If accept() fails then postmaster.c will still see the server
     730             :          * socket as read-ready, and will immediately try again.  To avoid
     731             :          * uselessly sucking lots of CPU, delay a bit before trying again.
     732             :          * (The most likely reason for failure is being out of kernel file
     733             :          * table slots; we can do little except hope some will get freed up.)
     734             :          */
     735           0 :         pg_usleep(100000L);     /* wait 0.1 sec */
     736           0 :         return STATUS_ERROR;
     737             :     }
     738             : 
     739             :     /* fill in the server (local) address */
     740        6906 :     port->laddr.salen = sizeof(port->laddr.addr);
     741       13812 :     if (getsockname(port->sock,
     742        6906 :                     (struct sockaddr *) &port->laddr.addr,
     743             :                     &port->laddr.salen) < 0)
     744             :     {
     745           0 :         elog(LOG, "getsockname() failed: %m");
     746           0 :         return STATUS_ERROR;
     747             :     }
     748             : 
     749             :     /* select NODELAY and KEEPALIVE options if it's a TCP connection */
     750        6906 :     if (!IS_AF_UNIX(port->laddr.addr.ss_family))
     751             :     {
     752             :         int         on;
     753             : #ifdef WIN32
     754             :         int         oldopt;
     755             :         int         optlen;
     756             :         int         newopt;
     757             : #endif
     758             : 
     759             : #ifdef  TCP_NODELAY
     760         390 :         on = 1;
     761         390 :         if (setsockopt(port->sock, IPPROTO_TCP, TCP_NODELAY,
     762             :                        (char *) &on, sizeof(on)) < 0)
     763             :         {
     764           0 :             elog(LOG, "setsockopt(%s) failed: %m", "TCP_NODELAY");
     765           0 :             return STATUS_ERROR;
     766             :         }
     767             : #endif
     768         390 :         on = 1;
     769         390 :         if (setsockopt(port->sock, SOL_SOCKET, SO_KEEPALIVE,
     770             :                        (char *) &on, sizeof(on)) < 0)
     771             :         {
     772           0 :             elog(LOG, "setsockopt(%s) failed: %m", "SO_KEEPALIVE");
     773           0 :             return STATUS_ERROR;
     774             :         }
     775             : 
     776             : #ifdef WIN32
     777             : 
     778             :         /*
     779             :          * This is a Win32 socket optimization.  The OS send buffer should be
     780             :          * large enough to send the whole Postgres send buffer in one go, or
     781             :          * performance suffers.  The Postgres send buffer can be enlarged if a
     782             :          * very large message needs to be sent, but we won't attempt to
     783             :          * enlarge the OS buffer if that happens, so somewhat arbitrarily
     784             :          * ensure that the OS buffer is at least PQ_SEND_BUFFER_SIZE * 4.
     785             :          * (That's 32kB with the current default).
     786             :          *
     787             :          * The default OS buffer size used to be 8kB in earlier Windows
     788             :          * versions, but was raised to 64kB in Windows 2012.  So it shouldn't
     789             :          * be necessary to change it in later versions anymore.  Changing it
     790             :          * unnecessarily can even reduce performance, because setting
     791             :          * SO_SNDBUF in the application disables the "dynamic send buffering"
     792             :          * feature that was introduced in Windows 7.  So before fiddling with
     793             :          * SO_SNDBUF, check if the current buffer size is already large enough
     794             :          * and only increase it if necessary.
     795             :          *
     796             :          * See https://support.microsoft.com/kb/823764/EN-US/ and
     797             :          * https://msdn.microsoft.com/en-us/library/bb736549%28v=vs.85%29.aspx
     798             :          */
     799             :         optlen = sizeof(oldopt);
     800             :         if (getsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &oldopt,
     801             :                        &optlen) < 0)
     802             :         {
     803             :             elog(LOG, "getsockopt(%s) failed: %m", "SO_SNDBUF");
     804             :             return STATUS_ERROR;
     805             :         }
     806             :         newopt = PQ_SEND_BUFFER_SIZE * 4;
     807             :         if (oldopt < newopt)
     808             :         {
     809             :             if (setsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &newopt,
     810             :                            sizeof(newopt)) < 0)
     811             :             {
     812             :                 elog(LOG, "setsockopt(%s) failed: %m", "SO_SNDBUF");
     813             :                 return STATUS_ERROR;
     814             :             }
     815             :         }
     816             : #endif
     817             : 
     818             :         /*
     819             :          * Also apply the current keepalive parameters.  If we fail to set a
     820             :          * parameter, don't error out, because these aren't universally
     821             :          * supported.  (Note: you might think we need to reset the GUC
     822             :          * variables to 0 in such a case, but it's not necessary because the
     823             :          * show hooks for these variables report the truth anyway.)
     824             :          */
     825         390 :         (void) pq_setkeepalivesidle(tcp_keepalives_idle, port);
     826         390 :         (void) pq_setkeepalivesinterval(tcp_keepalives_interval, port);
     827         390 :         (void) pq_setkeepalivescount(tcp_keepalives_count, port);
     828         390 :         (void) pq_settcpusertimeout(tcp_user_timeout, port);
     829             :     }
     830             : 
     831        6906 :     return STATUS_OK;
     832             : }
     833             : 
     834             : /*
     835             :  * StreamClose -- close a client/backend connection
     836             :  *
     837             :  * NOTE: this is NOT used to terminate a session; it is just used to release
     838             :  * the file descriptor in a process that should no longer have the socket
     839             :  * open.  (For example, the postmaster calls this after passing ownership
     840             :  * of the connection to a child process.)  It is expected that someone else
     841             :  * still has the socket open.  So, we only want to close the descriptor,
     842             :  * we do NOT want to send anything to the far end.
     843             :  */
     844             : void
     845       19872 : StreamClose(pgsocket sock)
     846             : {
     847       19872 :     closesocket(sock);
     848       19872 : }
     849             : 
     850             : /*
     851             :  * TouchSocketFiles -- mark socket files as recently accessed
     852             :  *
     853             :  * This routine should be called every so often to ensure that the socket
     854             :  * files have a recent mod date (ordinary operations on sockets usually won't
     855             :  * change the mod date).  That saves them from being removed by
     856             :  * overenthusiastic /tmp-directory-cleaner daemons.  (Another reason we should
     857             :  * never have put the socket file in /tmp...)
     858             :  */
     859             : void
     860           0 : TouchSocketFiles(void)
     861             : {
     862             :     ListCell   *l;
     863             : 
     864             :     /* Loop through all created sockets... */
     865           0 :     foreach(l, sock_paths)
     866             :     {
     867           0 :         char       *sock_path = (char *) lfirst(l);
     868             : 
     869             :         /*
     870             :          * utime() is POSIX standard, utimes() is a common alternative. If we
     871             :          * have neither, there's no way to affect the mod or access time of
     872             :          * the socket :-(
     873             :          *
     874             :          * In either path, we ignore errors; there's no point in complaining.
     875             :          */
     876             : #ifdef HAVE_UTIME
     877           0 :         utime(sock_path, NULL);
     878             : #else                           /* !HAVE_UTIME */
     879             : #ifdef HAVE_UTIMES
     880             :         utimes(sock_path, NULL);
     881             : #endif                          /* HAVE_UTIMES */
     882             : #endif                          /* HAVE_UTIME */
     883             :     }
     884           0 : }
     885             : 
     886             : /*
     887             :  * RemoveSocketFiles -- unlink socket files at postmaster shutdown
     888             :  */
     889             : void
     890         566 : RemoveSocketFiles(void)
     891             : {
     892             :     ListCell   *l;
     893             : 
     894             :     /* Loop through all created sockets... */
     895        1130 :     foreach(l, sock_paths)
     896             :     {
     897         564 :         char       *sock_path = (char *) lfirst(l);
     898             : 
     899             :         /* Ignore any error. */
     900         564 :         (void) unlink(sock_path);
     901             :     }
     902             :     /* Since we're about to exit, no need to reclaim storage */
     903         566 :     sock_paths = NIL;
     904         566 : }
     905             : 
     906             : 
     907             : /* --------------------------------
     908             :  * Low-level I/O routines begin here.
     909             :  *
     910             :  * These routines communicate with a frontend client across a connection
     911             :  * already established by the preceding routines.
     912             :  * --------------------------------
     913             :  */
     914             : 
     915             : /* --------------------------------
     916             :  *            socket_set_nonblocking - set socket blocking/non-blocking
     917             :  *
     918             :  * Sets the socket non-blocking if nonblocking is true, or sets it
     919             :  * blocking otherwise.
     920             :  * --------------------------------
     921             :  */
     922             : static void
     923     1045162 : socket_set_nonblocking(bool nonblocking)
     924             : {
     925     1045162 :     if (MyProcPort == NULL)
     926           0 :         ereport(ERROR,
     927             :                 (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
     928             :                  errmsg("there is no client connection")));
     929             : 
     930     1045162 :     MyProcPort->noblock = nonblocking;
     931     1045162 : }
     932             : 
     933             : /* --------------------------------
     934             :  *      pq_recvbuf - load some bytes into the input buffer
     935             :  *
     936             :  *      returns 0 if OK, EOF if trouble
     937             :  * --------------------------------
     938             :  */
     939             : static int
     940      321434 : pq_recvbuf(void)
     941             : {
     942      321434 :     if (PqRecvPointer > 0)
     943             :     {
     944      314646 :         if (PqRecvLength > PqRecvPointer)
     945             :         {
     946             :             /* still some unread data, left-justify it in the buffer */
     947           0 :             memmove(PqRecvBuffer, PqRecvBuffer + PqRecvPointer,
     948           0 :                     PqRecvLength - PqRecvPointer);
     949           0 :             PqRecvLength -= PqRecvPointer;
     950           0 :             PqRecvPointer = 0;
     951             :         }
     952             :         else
     953      314646 :             PqRecvLength = PqRecvPointer = 0;
     954             :     }
     955             : 
     956             :     /* Ensure that we're in blocking mode */
     957      321434 :     socket_set_nonblocking(false);
     958             : 
     959             :     /* Can fill buffer from PqRecvLength and upwards */
     960             :     for (;;)
     961           0 :     {
     962             :         int         r;
     963             : 
     964      321434 :         r = secure_read(MyProcPort, PqRecvBuffer + PqRecvLength,
     965      321434 :                         PQ_RECV_BUFFER_SIZE - PqRecvLength);
     966             : 
     967      321418 :         if (r < 0)
     968             :         {
     969           2 :             if (errno == EINTR)
     970           0 :                 continue;       /* Ok if interrupted */
     971             : 
     972             :             /*
     973             :              * Careful: an ereport() that tries to write to the client would
     974             :              * cause recursion to here, leading to stack overflow and core
     975             :              * dump!  This message must go *only* to the postmaster log.
     976             :              */
     977           2 :             ereport(COMMERROR,
     978             :                     (errcode_for_socket_access(),
     979             :                      errmsg("could not receive data from client: %m")));
     980           2 :             return EOF;
     981             :         }
     982      321416 :         if (r == 0)
     983             :         {
     984             :             /*
     985             :              * EOF detected.  We used to write a log message here, but it's
     986             :              * better to expect the ultimate caller to do that.
     987             :              */
     988          52 :             return EOF;
     989             :         }
     990             :         /* r contains number of bytes read, so just incr length */
     991      321364 :         PqRecvLength += r;
     992      321364 :         return 0;
     993             :     }
     994             : }
     995             : 
     996             : /* --------------------------------
     997             :  *      pq_getbyte  - get a single byte from connection, or return EOF
     998             :  * --------------------------------
     999             :  */
    1000             : int
    1001     1070314 : pq_getbyte(void)
    1002             : {
    1003             :     Assert(PqCommReadingMsg);
    1004             : 
    1005     2451598 :     while (PqRecvPointer >= PqRecvLength)
    1006             :     {
    1007      311030 :         if (pq_recvbuf())       /* If nothing in buffer, then recv some */
    1008          44 :             return EOF;         /* Failed to recv data */
    1009             :     }
    1010     1070254 :     return (unsigned char) PqRecvBuffer[PqRecvPointer++];
    1011             : }
    1012             : 
    1013             : /* --------------------------------
    1014             :  *      pq_peekbyte     - peek at next byte from connection
    1015             :  *
    1016             :  *   Same as pq_getbyte() except we don't advance the pointer.
    1017             :  * --------------------------------
    1018             :  */
    1019             : int
    1020           0 : pq_peekbyte(void)
    1021             : {
    1022             :     Assert(PqCommReadingMsg);
    1023             : 
    1024           0 :     while (PqRecvPointer >= PqRecvLength)
    1025             :     {
    1026           0 :         if (pq_recvbuf())       /* If nothing in buffer, then recv some */
    1027           0 :             return EOF;         /* Failed to recv data */
    1028             :     }
    1029           0 :     return (unsigned char) PqRecvBuffer[PqRecvPointer];
    1030             : }
    1031             : 
    1032             : /* --------------------------------
    1033             :  *      pq_getbyte_if_available - get a single byte from connection,
    1034             :  *          if available
    1035             :  *
    1036             :  * The received byte is stored in *c. Returns 1 if a byte was read,
    1037             :  * 0 if no data was available, or EOF if trouble.
    1038             :  * --------------------------------
    1039             :  */
    1040             : int
    1041       29338 : pq_getbyte_if_available(unsigned char *c)
    1042             : {
    1043             :     int         r;
    1044             : 
    1045             :     Assert(PqCommReadingMsg);
    1046             : 
    1047       29338 :     if (PqRecvPointer < PqRecvLength)
    1048             :     {
    1049         272 :         *c = PqRecvBuffer[PqRecvPointer++];
    1050         272 :         return 1;
    1051             :     }
    1052             : 
    1053             :     /* Put the socket into non-blocking mode */
    1054       29066 :     socket_set_nonblocking(true);
    1055             : 
    1056       29066 :     r = secure_read(MyProcPort, c, 1);
    1057       29066 :     if (r < 0)
    1058             :     {
    1059             :         /*
    1060             :          * Ok if no data available without blocking or interrupted (though
    1061             :          * EINTR really shouldn't happen with a non-blocking socket). Report
    1062             :          * other errors.
    1063             :          */
    1064       27790 :         if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
    1065       27784 :             r = 0;
    1066             :         else
    1067             :         {
    1068             :             /*
    1069             :              * Careful: an ereport() that tries to write to the client would
    1070             :              * cause recursion to here, leading to stack overflow and core
    1071             :              * dump!  This message must go *only* to the postmaster log.
    1072             :              */
    1073           6 :             ereport(COMMERROR,
    1074             :                     (errcode_for_socket_access(),
    1075             :                      errmsg("could not receive data from client: %m")));
    1076           6 :             r = EOF;
    1077             :         }
    1078             :     }
    1079        1276 :     else if (r == 0)
    1080             :     {
    1081             :         /* EOF detected */
    1082          14 :         r = EOF;
    1083             :     }
    1084             : 
    1085       29066 :     return r;
    1086             : }
    1087             : 
    1088             : /* --------------------------------
    1089             :  *      pq_getbytes     - get a known number of bytes from connection
    1090             :  *
    1091             :  *      returns 0 if OK, EOF if trouble
    1092             :  * --------------------------------
    1093             :  */
    1094             : int
    1095     2128036 : pq_getbytes(char *s, size_t len)
    1096             : {
    1097             :     size_t      amount;
    1098             : 
    1099             :     Assert(PqCommReadingMsg);
    1100             : 
    1101     6386068 :     while (len > 0)
    1102             :     {
    1103     4270406 :         while (PqRecvPointer >= PqRecvLength)
    1104             :         {
    1105       10404 :             if (pq_recvbuf())   /* If nothing in buffer, then recv some */
    1106          10 :                 return EOF;     /* Failed to recv data */
    1107             :         }
    1108     2129996 :         amount = PqRecvLength - PqRecvPointer;
    1109     2129996 :         if (amount > len)
    1110     1808684 :             amount = len;
    1111     2129996 :         memcpy(s, PqRecvBuffer + PqRecvPointer, amount);
    1112     2129996 :         PqRecvPointer += amount;
    1113     2129996 :         s += amount;
    1114     2129996 :         len -= amount;
    1115             :     }
    1116     2128026 :     return 0;
    1117             : }
    1118             : 
    1119             : /* --------------------------------
    1120             :  *      pq_discardbytes     - throw away a known number of bytes
    1121             :  *
    1122             :  *      same as pq_getbytes except we do not copy the data to anyplace.
    1123             :  *      this is used for resynchronizing after read errors.
    1124             :  *
    1125             :  *      returns 0 if OK, EOF if trouble
    1126             :  * --------------------------------
    1127             :  */
    1128             : static int
    1129           0 : pq_discardbytes(size_t len)
    1130             : {
    1131             :     size_t      amount;
    1132             : 
    1133             :     Assert(PqCommReadingMsg);
    1134             : 
    1135           0 :     while (len > 0)
    1136             :     {
    1137           0 :         while (PqRecvPointer >= PqRecvLength)
    1138             :         {
    1139           0 :             if (pq_recvbuf())   /* If nothing in buffer, then recv some */
    1140           0 :                 return EOF;     /* Failed to recv data */
    1141             :         }
    1142           0 :         amount = PqRecvLength - PqRecvPointer;
    1143           0 :         if (amount > len)
    1144           0 :             amount = len;
    1145           0 :         PqRecvPointer += amount;
    1146           0 :         len -= amount;
    1147             :     }
    1148           0 :     return 0;
    1149             : }
    1150             : 
    1151             : /* --------------------------------
    1152             :  *      pq_getstring    - get a null terminated string from connection
    1153             :  *
    1154             :  *      The return value is placed in an expansible StringInfo, which has
    1155             :  *      already been initialized by the caller.
    1156             :  *
    1157             :  *      This is used only for dealing with old-protocol clients.  The idea
    1158             :  *      is to produce a StringInfo that looks the same as we would get from
    1159             :  *      pq_getmessage() with a newer client; we will then process it with
    1160             :  *      pq_getmsgstring.  Therefore, no character set conversion is done here,
    1161             :  *      even though this is presumably useful only for text.
    1162             :  *
    1163             :  *      returns 0 if OK, EOF if trouble
    1164             :  * --------------------------------
    1165             :  */
    1166             : int
    1167           0 : pq_getstring(StringInfo s)
    1168             : {
    1169             :     int         i;
    1170             : 
    1171             :     Assert(PqCommReadingMsg);
    1172             : 
    1173           0 :     resetStringInfo(s);
    1174             : 
    1175             :     /* Read until we get the terminating '\0' */
    1176             :     for (;;)
    1177             :     {
    1178           0 :         while (PqRecvPointer >= PqRecvLength)
    1179             :         {
    1180           0 :             if (pq_recvbuf())   /* If nothing in buffer, then recv some */
    1181           0 :                 return EOF;     /* Failed to recv data */
    1182             :         }
    1183             : 
    1184           0 :         for (i = PqRecvPointer; i < PqRecvLength; i++)
    1185             :         {
    1186           0 :             if (PqRecvBuffer[i] == '\0')
    1187             :             {
    1188             :                 /* include the '\0' in the copy */
    1189           0 :                 appendBinaryStringInfo(s, PqRecvBuffer + PqRecvPointer,
    1190           0 :                                        i - PqRecvPointer + 1);
    1191           0 :                 PqRecvPointer = i + 1;  /* advance past \0 */
    1192           0 :                 return 0;
    1193             :             }
    1194             :         }
    1195             : 
    1196             :         /* If we're here we haven't got the \0 in the buffer yet. */
    1197           0 :         appendBinaryStringInfo(s, PqRecvBuffer + PqRecvPointer,
    1198             :                                PqRecvLength - PqRecvPointer);
    1199           0 :         PqRecvPointer = PqRecvLength;
    1200             :     }
    1201             : }
    1202             : 
    1203             : 
    1204             : /* --------------------------------
    1205             :  *      pq_startmsgread - begin reading a message from the client.
    1206             :  *
    1207             :  *      This must be called before any of the pq_get* functions.
    1208             :  * --------------------------------
    1209             :  */
    1210             : void
    1211     1106794 : pq_startmsgread(void)
    1212             : {
    1213             :     /*
    1214             :      * There shouldn't be a read active already, but let's check just to be
    1215             :      * sure.
    1216             :      */
    1217     1106794 :     if (PqCommReadingMsg)
    1218           0 :         ereport(FATAL,
    1219             :                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
    1220             :                  errmsg("terminating connection because protocol synchronization was lost")));
    1221             : 
    1222     1106794 :     PqCommReadingMsg = true;
    1223     1106794 : }
    1224             : 
    1225             : 
    1226             : /* --------------------------------
    1227             :  *      pq_endmsgread   - finish reading message.
    1228             :  *
    1229             :  *      This must be called after reading a V2 protocol message with
    1230             :  *      pq_getstring() and friends, to indicate that we have read the whole
    1231             :  *      message. In V3 protocol, pq_getmessage() does this implicitly.
    1232             :  * --------------------------------
    1233             :  */
    1234             : void
    1235       34916 : pq_endmsgread(void)
    1236             : {
    1237             :     Assert(PqCommReadingMsg);
    1238             : 
    1239       34916 :     PqCommReadingMsg = false;
    1240       34916 : }
    1241             : 
    1242             : /* --------------------------------
    1243             :  *      pq_is_reading_msg - are we currently reading a message?
    1244             :  *
    1245             :  * This is used in error recovery at the outer idle loop to detect if we have
    1246             :  * lost protocol sync, and need to terminate the connection. pq_startmsgread()
    1247             :  * will check for that too, but it's nicer to detect it earlier.
    1248             :  * --------------------------------
    1249             :  */
    1250             : bool
    1251       17894 : pq_is_reading_msg(void)
    1252             : {
    1253       17894 :     return PqCommReadingMsg;
    1254             : }
    1255             : 
    1256             : /* --------------------------------
    1257             :  *      pq_getmessage   - get a message with length word from connection
    1258             :  *
    1259             :  *      The return value is placed in an expansible StringInfo, which has
    1260             :  *      already been initialized by the caller.
    1261             :  *      Only the message body is placed in the StringInfo; the length word
    1262             :  *      is removed.  Also, s->cursor is initialized to zero for convenience
    1263             :  *      in scanning the message contents.
    1264             :  *
    1265             :  *      If maxlen is not zero, it is an upper limit on the length of the
    1266             :  *      message we are willing to accept.  We abort the connection (by
    1267             :  *      returning EOF) if client tries to send more than that.
    1268             :  *
    1269             :  *      returns 0 if OK, EOF if trouble
    1270             :  * --------------------------------
    1271             :  */
    1272             : int
    1273     1071788 : pq_getmessage(StringInfo s, int maxlen)
    1274             : {
    1275             :     int32       len;
    1276             : 
    1277             :     Assert(PqCommReadingMsg);
    1278             : 
    1279     1071788 :     resetStringInfo(s);
    1280             : 
    1281             :     /* Read message length word */
    1282     1071788 :     if (pq_getbytes((char *) &len, 4) == EOF)
    1283             :     {
    1284           0 :         ereport(COMMERROR,
    1285             :                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
    1286             :                  errmsg("unexpected EOF within message length word")));
    1287           0 :         return EOF;
    1288             :     }
    1289             : 
    1290     1071788 :     len = pg_ntoh32(len);
    1291             : 
    1292     1071788 :     if (len < 4 ||
    1293         110 :         (maxlen > 0 && len > maxlen))
    1294             :     {
    1295           0 :         ereport(COMMERROR,
    1296             :                 (errcode(ERRCODE_PROTOCOL_VIOLATION),
    1297             :                  errmsg("invalid message length")));
    1298           0 :         return EOF;
    1299             :     }
    1300             : 
    1301     1071788 :     len -= 4;                   /* discount length itself */
    1302             : 
    1303     1071788 :     if (len > 0)
    1304             :     {
    1305             :         /*
    1306             :          * Allocate space for message.  If we run out of room (ridiculously
    1307             :          * large message), we will elog(ERROR), but we want to discard the
    1308             :          * message body so as not to lose communication sync.
    1309             :          */
    1310     1034842 :         PG_TRY();
    1311             :         {
    1312     1034842 :             enlargeStringInfo(s, len);
    1313             :         }
    1314           0 :         PG_CATCH();
    1315             :         {
    1316           0 :             if (pq_discardbytes(len) == EOF)
    1317           0 :                 ereport(COMMERROR,
    1318             :                         (errcode(ERRCODE_PROTOCOL_VIOLATION),
    1319             :                          errmsg("incomplete message from client")));
    1320             : 
    1321             :             /* we discarded the rest of the message so we're back in sync. */
    1322           0 :             PqCommReadingMsg = false;
    1323           0 :             PG_RE_THROW();
    1324             :         }
    1325     1034842 :         PG_END_TRY();
    1326             : 
    1327             :         /* And grab the message */
    1328     1034842 :         if (pq_getbytes(s->data, len) == EOF)
    1329             :         {
    1330           0 :             ereport(COMMERROR,
    1331             :                     (errcode(ERRCODE_PROTOCOL_VIOLATION),
    1332             :                      errmsg("incomplete message from client")));
    1333           0 :             return EOF;
    1334             :         }
    1335     1034842 :         s->len = len;
    1336             :         /* Place a trailing null per StringInfo convention */
    1337     1034842 :         s->data[len] = '\0';
    1338             :     }
    1339             : 
    1340             :     /* finished reading the message. */
    1341     1071788 :     PqCommReadingMsg = false;
    1342             : 
    1343     1071788 :     return 0;
    1344             : }
    1345             : 
    1346             : 
    1347             : /* --------------------------------
    1348             :  *      pq_putbytes     - send bytes to connection (not flushed until pq_flush)
    1349             :  *
    1350             :  *      returns 0 if OK, EOF if trouble
    1351             :  * --------------------------------
    1352             :  */
    1353             : int
    1354           0 : pq_putbytes(const char *s, size_t len)
    1355             : {
    1356             :     int         res;
    1357             : 
    1358             :     /* Should only be called by old-style COPY OUT */
    1359             :     Assert(DoingCopyOut);
    1360             :     /* No-op if reentrant call */
    1361           0 :     if (PqCommBusy)
    1362           0 :         return 0;
    1363           0 :     PqCommBusy = true;
    1364           0 :     res = internal_putbytes(s, len);
    1365           0 :     PqCommBusy = false;
    1366           0 :     return res;
    1367             : }
    1368             : 
    1369             : static int
    1370    12621474 : internal_putbytes(const char *s, size_t len)
    1371             : {
    1372             :     size_t      amount;
    1373             : 
    1374    38164556 :     while (len > 0)
    1375             :     {
    1376             :         /* If buffer is full, then flush it out */
    1377    12921612 :         if (PqSendPointer >= PqSendBufferSize)
    1378             :         {
    1379      347150 :             socket_set_nonblocking(false);
    1380      347150 :             if (internal_flush())
    1381           4 :                 return EOF;
    1382             :         }
    1383    12921608 :         amount = PqSendBufferSize - PqSendPointer;
    1384    12921608 :         if (amount > len)
    1385    12571640 :             amount = len;
    1386    12921608 :         memcpy(PqSendBuffer + PqSendPointer, s, amount);
    1387    12921608 :         PqSendPointer += amount;
    1388    12921608 :         s += amount;
    1389    12921608 :         len -= amount;
    1390             :     }
    1391    12621470 :     return 0;
    1392             : }
    1393             : 
    1394             : /* --------------------------------
    1395             :  *      socket_flush        - flush pending output
    1396             :  *
    1397             :  *      returns 0 if OK, EOF if trouble
    1398             :  * --------------------------------
    1399             :  */
    1400             : static int
    1401      340948 : socket_flush(void)
    1402             : {
    1403             :     int         res;
    1404             : 
    1405             :     /* No-op if reentrant call */
    1406      340948 :     if (PqCommBusy)
    1407           0 :         return 0;
    1408      340948 :     PqCommBusy = true;
    1409      340948 :     socket_set_nonblocking(false);
    1410      340948 :     res = internal_flush();
    1411      340948 :     PqCommBusy = false;
    1412      340948 :     return res;
    1413             : }
    1414             : 
    1415             : /* --------------------------------
    1416             :  *      internal_flush - flush pending output
    1417             :  *
    1418             :  * Returns 0 if OK (meaning everything was sent, or operation would block
    1419             :  * and the socket is in non-blocking mode), or EOF if trouble.
    1420             :  * --------------------------------
    1421             :  */
    1422             : static int
    1423      694662 : internal_flush(void)
    1424             : {
    1425             :     static int  last_reported_send_errno = 0;
    1426             : 
    1427      694662 :     char       *bufptr = PqSendBuffer + PqSendStart;
    1428      694662 :     char       *bufend = PqSendBuffer + PqSendPointer;
    1429             : 
    1430     2083722 :     while (bufptr < bufend)
    1431             :     {
    1432             :         int         r;
    1433             : 
    1434      695786 :         r = secure_write(MyProcPort, bufptr, bufend - bufptr);
    1435             : 
    1436      695786 :         if (r <= 0)
    1437             :         {
    1438        1388 :             if (errno == EINTR)
    1439           0 :                 continue;       /* Ok if we were interrupted */
    1440             : 
    1441             :             /*
    1442             :              * Ok if no data writable without blocking, and the socket is in
    1443             :              * non-blocking mode.
    1444             :              */
    1445        1406 :             if (errno == EAGAIN ||
    1446          18 :                 errno == EWOULDBLOCK)
    1447             :             {
    1448        1370 :                 return 0;
    1449             :             }
    1450             : 
    1451             :             /*
    1452             :              * Careful: an ereport() that tries to write to the client would
    1453             :              * cause recursion to here, leading to stack overflow and core
    1454             :              * dump!  This message must go *only* to the postmaster log.
    1455             :              *
    1456             :              * If a client disconnects while we're in the midst of output, we
    1457             :              * might write quite a bit of data before we get to a safe query
    1458             :              * abort point.  So, suppress duplicate log messages.
    1459             :              */
    1460          18 :             if (errno != last_reported_send_errno)
    1461             :             {
    1462          10 :                 last_reported_send_errno = errno;
    1463          10 :                 ereport(COMMERROR,
    1464             :                         (errcode_for_socket_access(),
    1465             :                          errmsg("could not send data to client: %m")));
    1466             :             }
    1467             : 
    1468             :             /*
    1469             :              * We drop the buffered data anyway so that processing can
    1470             :              * continue, even though we'll probably quit soon. We also set a
    1471             :              * flag that'll cause the next CHECK_FOR_INTERRUPTS to terminate
    1472             :              * the connection.
    1473             :              */
    1474          18 :             PqSendStart = PqSendPointer = 0;
    1475          18 :             ClientConnectionLost = 1;
    1476          18 :             InterruptPending = 1;
    1477          18 :             return EOF;
    1478             :         }
    1479             : 
    1480      694398 :         last_reported_send_errno = 0;   /* reset after any successful send */
    1481      694398 :         bufptr += r;
    1482      694398 :         PqSendStart += r;
    1483             :     }
    1484             : 
    1485      693274 :     PqSendStart = PqSendPointer = 0;
    1486      693274 :     return 0;
    1487             : }
    1488             : 
    1489             : /* --------------------------------
    1490             :  *      pq_flush_if_writable - flush pending output if writable without blocking
    1491             :  *
    1492             :  * Returns 0 if OK, or EOF if trouble.
    1493             :  * --------------------------------
    1494             :  */
    1495             : static int
    1496       29094 : socket_flush_if_writable(void)
    1497             : {
    1498             :     int         res;
    1499             : 
    1500             :     /* Quick exit if nothing to do */
    1501       29094 :     if (PqSendPointer == PqSendStart)
    1502       22530 :         return 0;
    1503             : 
    1504             :     /* No-op if reentrant call */
    1505        6564 :     if (PqCommBusy)
    1506           0 :         return 0;
    1507             : 
    1508             :     /* Temporarily put the socket into non-blocking mode */
    1509        6564 :     socket_set_nonblocking(true);
    1510             : 
    1511        6564 :     PqCommBusy = true;
    1512        6564 :     res = internal_flush();
    1513        6564 :     PqCommBusy = false;
    1514        6564 :     return res;
    1515             : }
    1516             : 
    1517             : /* --------------------------------
    1518             :  *  socket_is_send_pending  - is there any pending data in the output buffer?
    1519             :  * --------------------------------
    1520             :  */
    1521             : static bool
    1522       61770 : socket_is_send_pending(void)
    1523             : {
    1524       61770 :     return (PqSendStart < PqSendPointer);
    1525             : }
    1526             : 
    1527             : /* --------------------------------
    1528             :  * Message-level I/O routines begin here.
    1529             :  *
    1530             :  * These routines understand about the old-style COPY OUT protocol.
    1531             :  * --------------------------------
    1532             :  */
    1533             : 
    1534             : 
    1535             : /* --------------------------------
    1536             :  *      socket_putmessage - send a normal message (suppressed in COPY OUT mode)
    1537             :  *
    1538             :  *      If msgtype is not '\0', it is a message type code to place before
    1539             :  *      the message body.  If msgtype is '\0', then the message has no type
    1540             :  *      code (this is only valid in pre-3.0 protocols).
    1541             :  *
    1542             :  *      len is the length of the message body data at *s.  In protocol 3.0
    1543             :  *      and later, a message length word (equal to len+4 because it counts
    1544             :  *      itself too) is inserted by this routine.
    1545             :  *
    1546             :  *      All normal messages are suppressed while old-style COPY OUT is in
    1547             :  *      progress.  (In practice only a few notice messages might get emitted
    1548             :  *      then; dropping them is annoying, but at least they will still appear
    1549             :  *      in the postmaster log.)
    1550             :  *
    1551             :  *      We also suppress messages generated while pqcomm.c is busy.  This
    1552             :  *      avoids any possibility of messages being inserted within other
    1553             :  *      messages.  The only known trouble case arises if SIGQUIT occurs
    1554             :  *      during a pqcomm.c routine --- quickdie() will try to send a warning
    1555             :  *      message, and the most reasonable approach seems to be to drop it.
    1556             :  *
    1557             :  *      returns 0 if OK, EOF if trouble
    1558             :  * --------------------------------
    1559             :  */
    1560             : static int
    1561     4207158 : socket_putmessage(char msgtype, const char *s, size_t len)
    1562             : {
    1563     4207158 :     if (DoingCopyOut || PqCommBusy)
    1564           0 :         return 0;
    1565     4207158 :     PqCommBusy = true;
    1566     4207158 :     if (msgtype)
    1567     4207158 :         if (internal_putbytes(&msgtype, 1))
    1568           0 :             goto fail;
    1569     4207158 :     if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
    1570             :     {
    1571             :         uint32      n32;
    1572             : 
    1573     4207158 :         n32 = pg_hton32((uint32) (len + 4));
    1574     4207158 :         if (internal_putbytes((char *) &n32, 4))
    1575           0 :             goto fail;
    1576             :     }
    1577     4207158 :     if (internal_putbytes(s, len))
    1578           4 :         goto fail;
    1579     4207154 :     PqCommBusy = false;
    1580     4207154 :     return 0;
    1581             : 
    1582             : fail:
    1583           4 :     PqCommBusy = false;
    1584           4 :     return EOF;
    1585             : }
    1586             : 
    1587             : /* --------------------------------
    1588             :  *      pq_putmessage_noblock   - like pq_putmessage, but never blocks
    1589             :  *
    1590             :  *      If the output buffer is too small to hold the message, the buffer
    1591             :  *      is enlarged.
    1592             :  */
    1593             : static void
    1594        5252 : socket_putmessage_noblock(char msgtype, const char *s, size_t len)
    1595             : {
    1596             :     int         res PG_USED_FOR_ASSERTS_ONLY;
    1597             :     int         required;
    1598             : 
    1599             :     /*
    1600             :      * Ensure we have enough space in the output buffer for the message header
    1601             :      * as well as the message itself.
    1602             :      */
    1603        5252 :     required = PqSendPointer + 1 + 4 + len;
    1604        5252 :     if (required > PqSendBufferSize)
    1605             :     {
    1606         306 :         PqSendBuffer = repalloc(PqSendBuffer, required);
    1607         306 :         PqSendBufferSize = required;
    1608             :     }
    1609        5252 :     res = pq_putmessage(msgtype, s, len);
    1610             :     Assert(res == 0);           /* should not fail when the message fits in
    1611             :                                  * buffer */
    1612        5252 : }
    1613             : 
    1614             : 
    1615             : /* --------------------------------
    1616             :  *      socket_startcopyout - inform libpq that an old-style COPY OUT transfer
    1617             :  *          is beginning
    1618             :  * --------------------------------
    1619             :  */
    1620             : static void
    1621           0 : socket_startcopyout(void)
    1622             : {
    1623           0 :     DoingCopyOut = true;
    1624           0 : }
    1625             : 
    1626             : /* --------------------------------
    1627             :  *      socket_endcopyout   - end an old-style COPY OUT transfer
    1628             :  *
    1629             :  *      If errorAbort is indicated, we are aborting a COPY OUT due to an error,
    1630             :  *      and must send a terminator line.  Since a partial data line might have
    1631             :  *      been emitted, send a couple of newlines first (the first one could
    1632             :  *      get absorbed by a backslash...)  Note that old-style COPY OUT does
    1633             :  *      not allow binary transfers, so a textual terminator is always correct.
    1634             :  * --------------------------------
    1635             :  */
    1636             : static void
    1637       18002 : socket_endcopyout(bool errorAbort)
    1638             : {
    1639       18002 :     if (!DoingCopyOut)
    1640       18002 :         return;
    1641           0 :     if (errorAbort)
    1642           0 :         pq_putbytes("\n\n\\.\n", 5);
    1643             :     /* in non-error case, copy.c will have emitted the terminator line */
    1644           0 :     DoingCopyOut = false;
    1645             : }
    1646             : 
    1647             : /*
    1648             :  * Support for TCP Keepalive parameters
    1649             :  */
    1650             : 
    1651             : /*
    1652             :  * On Windows, we need to set both idle and interval at the same time.
    1653             :  * We also cannot reset them to the default (setting to zero will
    1654             :  * actually set them to zero, not default), therefore we fallback to
    1655             :  * the out-of-the-box default instead.
    1656             :  */
    1657             : #if defined(WIN32) && defined(SIO_KEEPALIVE_VALS)
    1658             : static int
    1659             : pq_setkeepaliveswin32(Port *port, int idle, int interval)
    1660             : {
    1661             :     struct tcp_keepalive ka;
    1662             :     DWORD       retsize;
    1663             : 
    1664             :     if (idle <= 0)
    1665             :         idle = 2 * 60 * 60;     /* default = 2 hours */
    1666             :     if (interval <= 0)
    1667             :         interval = 1;           /* default = 1 second */
    1668             : 
    1669             :     ka.onoff = 1;
    1670             :     ka.keepalivetime = idle * 1000;
    1671             :     ka.keepaliveinterval = interval * 1000;
    1672             : 
    1673             :     if (WSAIoctl(port->sock,
    1674             :                  SIO_KEEPALIVE_VALS,
    1675             :                  (LPVOID) &ka,
    1676             :                  sizeof(ka),
    1677             :                  NULL,
    1678             :                  0,
    1679             :                  &retsize,
    1680             :                  NULL,
    1681             :                  NULL)
    1682             :         != 0)
    1683             :     {
    1684             :         elog(LOG, "WSAIoctl(SIO_KEEPALIVE_VALS) failed: %ui",
    1685             :              WSAGetLastError());
    1686             :         return STATUS_ERROR;
    1687             :     }
    1688             :     if (port->keepalives_idle != idle)
    1689             :         port->keepalives_idle = idle;
    1690             :     if (port->keepalives_interval != interval)
    1691             :         port->keepalives_interval = interval;
    1692             :     return STATUS_OK;
    1693             : }
    1694             : #endif
    1695             : 
    1696             : int
    1697          32 : pq_getkeepalivesidle(Port *port)
    1698             : {
    1699             : #if defined(PG_TCP_KEEPALIVE_IDLE) || defined(SIO_KEEPALIVE_VALS)
    1700          32 :     if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
    1701          32 :         return 0;
    1702             : 
    1703           0 :     if (port->keepalives_idle != 0)
    1704           0 :         return port->keepalives_idle;
    1705             : 
    1706           0 :     if (port->default_keepalives_idle == 0)
    1707             :     {
    1708             : #ifndef WIN32
    1709           0 :         ACCEPT_TYPE_ARG3 size = sizeof(port->default_keepalives_idle);
    1710             : 
    1711           0 :         if (getsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
    1712           0 :                        (char *) &port->default_keepalives_idle,
    1713             :                        &size) < 0)
    1714             :         {
    1715           0 :             elog(LOG, "getsockopt(%s) failed: %m", PG_TCP_KEEPALIVE_IDLE_STR);
    1716           0 :             port->default_keepalives_idle = -1; /* don't know */
    1717             :         }
    1718             : #else                           /* WIN32 */
    1719             :         /* We can't get the defaults on Windows, so return "don't know" */
    1720             :         port->default_keepalives_idle = -1;
    1721             : #endif                          /* WIN32 */
    1722             :     }
    1723             : 
    1724           0 :     return port->default_keepalives_idle;
    1725             : #else
    1726             :     return 0;
    1727             : #endif
    1728             : }
    1729             : 
    1730             : int
    1731        2252 : pq_setkeepalivesidle(int idle, Port *port)
    1732             : {
    1733        2252 :     if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
    1734        1862 :         return STATUS_OK;
    1735             : 
    1736             : /* check SIO_KEEPALIVE_VALS here, not just WIN32, as some toolchains lack it */
    1737             : #if defined(PG_TCP_KEEPALIVE_IDLE) || defined(SIO_KEEPALIVE_VALS)
    1738         390 :     if (idle == port->keepalives_idle)
    1739         390 :         return STATUS_OK;
    1740             : 
    1741             : #ifndef WIN32
    1742           0 :     if (port->default_keepalives_idle <= 0)
    1743             :     {
    1744           0 :         if (pq_getkeepalivesidle(port) < 0)
    1745             :         {
    1746           0 :             if (idle == 0)
    1747           0 :                 return STATUS_OK;   /* default is set but unknown */
    1748             :             else
    1749           0 :                 return STATUS_ERROR;
    1750             :         }
    1751             :     }
    1752             : 
    1753           0 :     if (idle == 0)
    1754           0 :         idle = port->default_keepalives_idle;
    1755             : 
    1756           0 :     if (setsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
    1757             :                    (char *) &idle, sizeof(idle)) < 0)
    1758             :     {
    1759           0 :         elog(LOG, "setsockopt(%s) failed: %m", PG_TCP_KEEPALIVE_IDLE_STR);
    1760           0 :         return STATUS_ERROR;
    1761             :     }
    1762             : 
    1763           0 :     port->keepalives_idle = idle;
    1764             : #else                           /* WIN32 */
    1765             :     return pq_setkeepaliveswin32(port, idle, port->keepalives_interval);
    1766             : #endif
    1767             : #else
    1768             :     if (idle != 0)
    1769             :     {
    1770             :         elog(LOG, "setting the keepalive idle time is not supported");
    1771             :         return STATUS_ERROR;
    1772             :     }
    1773             : #endif
    1774             : 
    1775           0 :     return STATUS_OK;
    1776             : }
    1777             : 
    1778             : int
    1779          32 : pq_getkeepalivesinterval(Port *port)
    1780             : {
    1781             : #if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
    1782          32 :     if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
    1783          32 :         return 0;
    1784             : 
    1785           0 :     if (port->keepalives_interval != 0)
    1786           0 :         return port->keepalives_interval;
    1787             : 
    1788           0 :     if (port->default_keepalives_interval == 0)
    1789             :     {
    1790             : #ifndef WIN32
    1791           0 :         ACCEPT_TYPE_ARG3 size = sizeof(port->default_keepalives_interval);
    1792             : 
    1793           0 :         if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
    1794           0 :                        (char *) &port->default_keepalives_interval,
    1795             :                        &size) < 0)
    1796             :         {
    1797           0 :             elog(LOG, "getsockopt(%s) failed: %m", "TCP_KEEPINTVL");
    1798           0 :             port->default_keepalives_interval = -1; /* don't know */
    1799             :         }
    1800             : #else
    1801             :         /* We can't get the defaults on Windows, so return "don't know" */
    1802             :         port->default_keepalives_interval = -1;
    1803             : #endif                          /* WIN32 */
    1804             :     }
    1805             : 
    1806           0 :     return port->default_keepalives_interval;
    1807             : #else
    1808             :     return 0;
    1809             : #endif
    1810             : }
    1811             : 
    1812             : int
    1813        2252 : pq_setkeepalivesinterval(int interval, Port *port)
    1814             : {
    1815        2252 :     if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
    1816        1862 :         return STATUS_OK;
    1817             : 
    1818             : #if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
    1819         390 :     if (interval == port->keepalives_interval)
    1820         390 :         return STATUS_OK;
    1821             : 
    1822             : #ifndef WIN32
    1823           0 :     if (port->default_keepalives_interval <= 0)
    1824             :     {
    1825           0 :         if (pq_getkeepalivesinterval(port) < 0)
    1826             :         {
    1827           0 :             if (interval == 0)
    1828           0 :                 return STATUS_OK;   /* default is set but unknown */
    1829             :             else
    1830           0 :                 return STATUS_ERROR;
    1831             :         }
    1832             :     }
    1833             : 
    1834           0 :     if (interval == 0)
    1835           0 :         interval = port->default_keepalives_interval;
    1836             : 
    1837           0 :     if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
    1838             :                    (char *) &interval, sizeof(interval)) < 0)
    1839             :     {
    1840           0 :         elog(LOG, "setsockopt(%s) failed: %m", "TCP_KEEPINTVL");
    1841           0 :         return STATUS_ERROR;
    1842             :     }
    1843             : 
    1844           0 :     port->keepalives_interval = interval;
    1845             : #else                           /* WIN32 */
    1846             :     return pq_setkeepaliveswin32(port, port->keepalives_idle, interval);
    1847             : #endif
    1848             : #else
    1849             :     if (interval != 0)
    1850             :     {
    1851             :         elog(LOG, "setsockopt(%s) not supported", "TCP_KEEPINTVL");
    1852             :         return STATUS_ERROR;
    1853             :     }
    1854             : #endif
    1855             : 
    1856           0 :     return STATUS_OK;
    1857             : }
    1858             : 
    1859             : int
    1860          32 : pq_getkeepalivescount(Port *port)
    1861             : {
    1862             : #ifdef TCP_KEEPCNT
    1863          32 :     if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
    1864          32 :         return 0;
    1865             : 
    1866           0 :     if (port->keepalives_count != 0)
    1867           0 :         return port->keepalives_count;
    1868             : 
    1869           0 :     if (port->default_keepalives_count == 0)
    1870             :     {
    1871           0 :         ACCEPT_TYPE_ARG3 size = sizeof(port->default_keepalives_count);
    1872             : 
    1873           0 :         if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
    1874           0 :                        (char *) &port->default_keepalives_count,
    1875             :                        &size) < 0)
    1876             :         {
    1877           0 :             elog(LOG, "getsockopt(%s) failed: %m", "TCP_KEEPCNT");
    1878           0 :             port->default_keepalives_count = -1; /* don't know */
    1879             :         }
    1880             :     }
    1881             : 
    1882           0 :     return port->default_keepalives_count;
    1883             : #else
    1884             :     return 0;
    1885             : #endif
    1886             : }
    1887             : 
    1888             : int
    1889        2252 : pq_setkeepalivescount(int count, Port *port)
    1890             : {
    1891        2252 :     if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
    1892        1862 :         return STATUS_OK;
    1893             : 
    1894             : #ifdef TCP_KEEPCNT
    1895         390 :     if (count == port->keepalives_count)
    1896         390 :         return STATUS_OK;
    1897             : 
    1898           0 :     if (port->default_keepalives_count <= 0)
    1899             :     {
    1900           0 :         if (pq_getkeepalivescount(port) < 0)
    1901             :         {
    1902           0 :             if (count == 0)
    1903           0 :                 return STATUS_OK;   /* default is set but unknown */
    1904             :             else
    1905           0 :                 return STATUS_ERROR;
    1906             :         }
    1907             :     }
    1908             : 
    1909           0 :     if (count == 0)
    1910           0 :         count = port->default_keepalives_count;
    1911             : 
    1912           0 :     if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
    1913             :                    (char *) &count, sizeof(count)) < 0)
    1914             :     {
    1915           0 :         elog(LOG, "setsockopt(%s) failed: %m", "TCP_KEEPCNT");
    1916           0 :         return STATUS_ERROR;
    1917             :     }
    1918             : 
    1919           0 :     port->keepalives_count = count;
    1920             : #else
    1921             :     if (count != 0)
    1922             :     {
    1923             :         elog(LOG, "setsockopt(%s) not supported", "TCP_KEEPCNT");
    1924             :         return STATUS_ERROR;
    1925             :     }
    1926             : #endif
    1927             : 
    1928           0 :     return STATUS_OK;
    1929             : }
    1930             : 
    1931             : int
    1932          32 : pq_gettcpusertimeout(Port *port)
    1933             : {
    1934             : #ifdef TCP_USER_TIMEOUT
    1935          32 :     if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
    1936          32 :         return 0;
    1937             : 
    1938           0 :     if (port->tcp_user_timeout != 0)
    1939           0 :         return port->tcp_user_timeout;
    1940             : 
    1941           0 :     if (port->default_tcp_user_timeout == 0)
    1942             :     {
    1943           0 :         ACCEPT_TYPE_ARG3 size = sizeof(port->default_tcp_user_timeout);
    1944             : 
    1945           0 :         if (getsockopt(port->sock, IPPROTO_TCP, TCP_USER_TIMEOUT,
    1946           0 :                        (char *) &port->default_tcp_user_timeout,
    1947             :                        &size) < 0)
    1948             :         {
    1949           0 :             elog(LOG, "getsockopt(%s) failed: %m", "TCP_USER_TIMEOUT");
    1950           0 :             port->default_tcp_user_timeout = -1; /* don't know */
    1951             :         }
    1952             :     }
    1953             : 
    1954           0 :     return port->default_tcp_user_timeout;
    1955             : #else
    1956             :     return 0;
    1957             : #endif
    1958             : }
    1959             : 
    1960             : int
    1961        2252 : pq_settcpusertimeout(int timeout, Port *port)
    1962             : {
    1963        2252 :     if (port == NULL || IS_AF_UNIX(port->laddr.addr.ss_family))
    1964        1862 :         return STATUS_OK;
    1965             : 
    1966             : #ifdef TCP_USER_TIMEOUT
    1967         390 :     if (timeout == port->tcp_user_timeout)
    1968         390 :         return STATUS_OK;
    1969             : 
    1970           0 :     if (port->default_tcp_user_timeout <= 0)
    1971             :     {
    1972           0 :         if (pq_gettcpusertimeout(port) < 0)
    1973             :         {
    1974           0 :             if (timeout == 0)
    1975           0 :                 return STATUS_OK;   /* default is set but unknown */
    1976             :             else
    1977           0 :                 return STATUS_ERROR;
    1978             :         }
    1979             :     }
    1980             : 
    1981           0 :     if (timeout == 0)
    1982           0 :         timeout = port->default_tcp_user_timeout;
    1983             : 
    1984           0 :     if (setsockopt(port->sock, IPPROTO_TCP, TCP_USER_TIMEOUT,
    1985             :                    (char *) &timeout, sizeof(timeout)) < 0)
    1986             :     {
    1987           0 :         elog(LOG, "setsockopt(%s) failed: %m", "TCP_USER_TIMEOUT");
    1988           0 :         return STATUS_ERROR;
    1989             :     }
    1990             : 
    1991           0 :     port->tcp_user_timeout = timeout;
    1992             : #else
    1993             :     if (timeout != 0)
    1994             :     {
    1995             :         elog(LOG, "setsockopt(%s) not supported", "TCP_USER_TIMEOUT");
    1996             :         return STATUS_ERROR;
    1997             :     }
    1998             : #endif
    1999             : 
    2000           0 :     return STATUS_OK;
    2001             : }

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