1032 lines
28 KiB
C++
1032 lines
28 KiB
C++
/* -------------------------------------------------------------------------
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*
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* FILE
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* fe-misc.c
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*
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* DESCRIPTION
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* miscellaneous useful functions
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*
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* The communication routines here are analogous to the ones in
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* backend/libpq/pqcomm.c and backend/libpq/pqcomprim.c, but operate
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* in the considerably different environment of the frontend libpq.
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* In particular, we work with a bare nonblock-mode socket, rather than
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* a stdio stream, so that we can avoid unwanted blocking of the application.
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*
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* XXX: MOVE DEBUG PRINTOUT TO HIGHER LEVEL. As is, block and restart
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* will cause repeat printouts.
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*
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* We must speak the same transmitted data representations as the backend
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* routines.
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*
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*
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* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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* Portions Copyright (c) 2010-2012 Postgres-XC Development Group
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/interfaces/libpq/fe-misc.c,v 1.137 2008/12/11 07:34:09 petere Exp $
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*
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* -------------------------------------------------------------------------
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*/
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#include "gtm/gtm_c.h"
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#include <signal.h>
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#include <time.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <unistd.h>
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#include <sys/time.h>
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#include <poll.h>
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#include <sys/poll.h>
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#include <sys/select.h>
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#include "gtm/libpq-fe.h"
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#include "gtm/libpq-int.h"
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static int gtmpqPutMsgBytes(const void* buf, size_t len, GTM_Conn* conn);
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static int gtmpqSendSome(GTM_Conn* conn, int len);
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static int gtmpqSocketCheck(GTM_Conn* conn, int forRead, int forWrite, time_t end_time);
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static int gtmpqSocketPoll(int sock, int forRead, int forWrite, time_t end_time);
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/*
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* gtmpqGetc: get 1 character from the connection
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*
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* All these routines return 0 on success, EOF on error.
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* Note that for the Get routines, EOF only means there is not enough
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* data in the buffer, not that there is necessarily a hard error.
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*/
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int gtmpqGetc(char* result, GTM_Conn* conn)
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{
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if (conn->inCursor >= conn->inEnd) {
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return EOF;
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}
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*result = conn->inBuffer[conn->inCursor++];
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if (conn->Pfdebug) {
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fprintf(conn->Pfdebug, "From backend> %c\n", *result);
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}
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return 0;
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}
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/*
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* gtmpqPutc: write 1 char to the current message
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*/
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int gtmpqPutc(char c, GTM_Conn* conn)
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{
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if (gtmpqPutMsgBytes(&c, 1, conn)) {
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return EOF;
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}
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if (conn->Pfdebug) {
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fprintf(conn->Pfdebug, "To backend> %c\n", c);
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}
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return 0;
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}
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/*
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* gtmpqGets[_append]:
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* get a null-terminated string from the connection,
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* and store it in an expansible PQExpBuffer.
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* If we run out of memory, all of the string is still read,
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* but the excess characters are silently discarded.
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*/
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static int gtmpqGets_internal(PQExpBuffer buf, GTM_Conn* conn, bool resetbuffer)
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{
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/* Copy conn data to locals for faster search loop */
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char* inBuffer = conn->inBuffer;
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int inCursor = conn->inCursor;
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int inEnd = conn->inEnd;
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int slen;
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while (inCursor < inEnd && inBuffer[inCursor]) {
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inCursor++;
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}
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if (inCursor >= inEnd) {
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return EOF;
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}
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slen = inCursor - conn->inCursor;
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if (resetbuffer) {
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resetGTMPQExpBuffer(buf);
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}
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appendBinaryGTMPQExpBuffer(buf, inBuffer + conn->inCursor, slen);
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conn->inCursor = ++inCursor;
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if (conn->Pfdebug) {
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fprintf(conn->Pfdebug, "From backend> \"%s\"\n", buf->data);
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}
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return 0;
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}
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int gtmpqGets(PQExpBuffer buf, GTM_Conn* conn)
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{
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return gtmpqGets_internal(buf, conn, true);
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}
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int gtmpqGets_append(PQExpBuffer buf, GTM_Conn* conn)
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{
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return gtmpqGets_internal(buf, conn, false);
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}
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/*
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* gtmpqPuts: write a null-terminated string to the current message
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*/
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int gtmpqPuts(const char* s, GTM_Conn* conn)
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{
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if (gtmpqPutMsgBytes(s, strlen(s) + 1, conn)) {
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return EOF;
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}
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if (conn->Pfdebug) {
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fprintf(conn->Pfdebug, "To backend> \"%s\"\n", s);
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}
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return 0;
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}
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/*
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* gtmpqGetnchar:
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* get a string of exactly len bytes in buffer s, no null termination
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*/
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int gtmpqGetnchar(char* s, size_t len, GTM_Conn* conn)
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{
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errno_t rc = EOK;
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if (len < 0 || len > (size_t)(conn->inEnd - conn->inCursor)) {
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return EOF;
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}
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rc = memcpy_s(s, len, conn->inBuffer + conn->inCursor, len);
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securec_check(rc, "\0", "\0");
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/* no terminating null */
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conn->inCursor += len;
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if (conn->Pfdebug) {
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fprintf(conn->Pfdebug, "From backend (%lu)> %.*s\n", (unsigned long)len, (int)len, s);
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}
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return 0;
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}
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/*
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* gtmpqPutnchar:
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* write exactly len bytes to the current message
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*/
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int gtmpqPutnchar(const char* s, size_t len, GTM_Conn* conn)
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{
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if (gtmpqPutMsgBytes(s, len, conn)) {
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return EOF;
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}
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if (conn->Pfdebug) {
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fprintf(conn->Pfdebug, "To backend> %.*s\n", (int)len, s);
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}
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return 0;
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}
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/*
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* gtmpqGetInt
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* read a 2 or 4 byte integer and convert from network byte order
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* to local byte order
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*/
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int gtmpqGetInt(int* result, size_t bytes, GTM_Conn* conn)
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{
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uint16 tmp2;
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uint32 tmp4;
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errno_t rc = EOK;
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switch (bytes) {
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case 2:
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if (conn->inCursor + 2 > conn->inEnd) {
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return EOF;
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}
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rc = memcpy_s(&tmp2, 2, conn->inBuffer + conn->inCursor, 2);
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securec_check(rc, "\0", "\0");
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conn->inCursor += 2;
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*result = (int)ntohs(tmp2);
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break;
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case 4:
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if (conn->inCursor + 4 > conn->inEnd) {
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return EOF;
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}
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rc = memcpy_s(&tmp4, 4, conn->inBuffer + conn->inCursor, 4);
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securec_check(rc, "\0", "\0");
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conn->inCursor += 4;
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*result = (int)ntohl(tmp4);
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break;
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default:
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fprintf(conn->Pfdebug, "Integer size of (%ld) bytes not supported", bytes);
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return EOF;
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}
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if (conn->Pfdebug) {
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fprintf(conn->Pfdebug, "From backend (#%lu)> %d\n", (unsigned long)bytes, *result);
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}
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return 0;
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}
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/*
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* gtmpqPutInt
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* write an integer of 2 or 4 bytes, converting from host byte order
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* to network byte order.
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*/
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int gtmpqPutInt(int value, size_t bytes, GTM_Conn* conn)
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{
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uint16 tmp2;
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uint32 tmp4;
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switch (bytes) {
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case 2:
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tmp2 = htons((uint16)value);
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if (gtmpqPutMsgBytes((const char*)&tmp2, 2, conn))
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return EOF;
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break;
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case 4:
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tmp4 = htonl((uint32)value);
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if (gtmpqPutMsgBytes((const char*)&tmp4, 4, conn))
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return EOF;
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break;
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default:
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fprintf(conn->Pfdebug, "Integer size of (%ld) bytes not supported", bytes);
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return EOF;
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}
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if (conn->Pfdebug) {
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fprintf(conn->Pfdebug, "To backend (%lu#)> %d\n", (unsigned long)bytes, value);
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}
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return 0;
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}
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/*
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* Make sure conn's output buffer can hold bytes_needed bytes (caller must
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* include already-stored data into the value!)
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*
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* Returns 0 on success, EOF if failed to enlarge buffer
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*/
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int gtmpqCheckOutBufferSpace(size_t bytes_needed, GTM_Conn* conn)
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{
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int newsize = conn->outBufSize;
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char* newbuf;
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if (bytes_needed <= (size_t)newsize) {
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return 0;
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}
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/*
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* If we need to enlarge the buffer, we first try to double it in size; if
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* that doesn't work, enlarge in multiples of 8K. This avoids thrashing
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* the malloc pool by repeated small enlargements.
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*
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* Note: tests for newsize > 0 are to catch integer overflow.
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*/
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do {
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newsize *= 2;
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} while (newsize > 0 && bytes_needed > (size_t)newsize);
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if (newsize > 0 && bytes_needed <= (size_t)newsize) {
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newbuf = realloc(conn->outBuffer, newsize);
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if (newbuf) {
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/* realloc succeeded */
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conn->outBuffer = newbuf;
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conn->outBufSize = newsize;
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return 0;
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}
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}
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newsize = conn->outBufSize;
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do {
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newsize += 8192;
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} while (newsize > 0 && bytes_needed > (size_t)newsize);
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if (newsize > 0 && bytes_needed <= (size_t)newsize) {
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newbuf = realloc(conn->outBuffer, newsize);
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if (newbuf) {
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/* realloc succeeded */
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conn->outBuffer = newbuf;
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conn->outBufSize = newsize;
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return 0;
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}
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}
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/* realloc failed. Probably out of memory */
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printfGTMPQExpBuffer(&conn->errorMessage, "cannot allocate memory for output buffer\n");
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return EOF;
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}
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/*
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* Make sure conn's input buffer can hold bytes_needed bytes (caller must
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* include already-stored data into the value!)
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*
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* Returns 0 on success, EOF if failed to enlarge buffer
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*/
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int gtmpqCheckInBufferSpace(size_t bytes_needed, GTM_Conn* conn)
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{
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int newsize = conn->inBufSize;
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char* newbuf;
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if (bytes_needed <= (size_t)newsize) {
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return 0;
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}
|
|
|
|
/*
|
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* If we need to enlarge the buffer, we first try to double it in size; if
|
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* that doesn't work, enlarge in multiples of 8K. This avoids thrashing
|
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* the malloc pool by repeated small enlargements.
|
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*
|
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* Note: tests for newsize > 0 are to catch integer overflow.
|
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*/
|
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do {
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newsize *= 2;
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} while (newsize > 0 && bytes_needed > (size_t)newsize);
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if (newsize > 0 && bytes_needed <= (size_t)newsize) {
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newbuf = realloc(conn->inBuffer, newsize);
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if (newbuf) {
|
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/* realloc succeeded */
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conn->inBuffer = newbuf;
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conn->inBufSize = newsize;
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return 0;
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}
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}
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newsize = conn->inBufSize;
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do {
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newsize += 8192;
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} while (newsize > 0 && bytes_needed > (size_t)newsize);
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if (newsize > 0 && bytes_needed <= (size_t)newsize) {
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newbuf = realloc(conn->inBuffer, newsize);
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if (newbuf) {
|
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/* realloc succeeded */
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conn->inBuffer = newbuf;
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conn->inBufSize = newsize;
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return 0;
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}
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}
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/* realloc failed. Probably out of memory */
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printfGTMPQExpBuffer(&conn->errorMessage, "cannot allocate memory for input buffer\n");
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return EOF;
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}
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|
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/*
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* gtmpqPutMsgStart: begin construction of a message to the server
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*
|
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* msg_type is the message type byte, or 0 for a message without type byte
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* (only startup messages have no type byte)
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*
|
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* force_len forces the message to have a length word; otherwise, we add
|
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* a length word if protocol 3.
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*
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* Returns 0 on success, EOF on error
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*
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* The idea here is that we construct the message in conn->outBuffer,
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* beginning just past any data already in outBuffer (ie, at
|
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* outBuffer+outCount). We enlarge the buffer as needed to hold the message.
|
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* When the message is complete, we fill in the length word (if needed) and
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* then advance outCount past the message, making it eligible to send.
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*
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* The state variable conn->outMsgStart points to the incomplete message's
|
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* length word: it is either outCount or outCount+1 depending on whether
|
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* there is a type byte. If we are sending a message without length word
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* (pre protocol 3.0 only), then outMsgStart is -1. The state variable
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* conn->outMsgEnd is the end of the data collected so far.
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*/
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int gtmpqPutMsgStart(char msg_type, bool force_len, GTM_Conn* conn)
|
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{
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int lenPos;
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int endPos;
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|
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/* allow room for message type byte */
|
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if (msg_type) {
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endPos = conn->outCount + 1;
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} else {
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endPos = conn->outCount;
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}
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|
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/* do we want a length word? */
|
|
if (force_len) {
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lenPos = endPos;
|
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/* allow room for message length */
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endPos += 4;
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} else {
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lenPos = -1;
|
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}
|
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|
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/* make sure there is room for message header */
|
|
if (gtmpqCheckOutBufferSpace(endPos, conn)) {
|
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return EOF;
|
|
}
|
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|
|
/* okay, save the message type byte if any */
|
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if (msg_type) {
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conn->outBuffer[conn->outCount] = msg_type;
|
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}
|
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|
|
/* set up the message pointers */
|
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conn->outMsgStart = lenPos;
|
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conn->outMsgEnd = endPos;
|
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|
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/* length word, if needed, will be filled in by gtmpqPutMsgEnd */
|
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if (conn->Pfdebug) {
|
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fprintf(conn->Pfdebug, "To backend> Msg %c\n", msg_type ? msg_type : ' ');
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* gtmpqPutMsgBytes: add bytes to a partially-constructed message
|
|
*
|
|
* Returns 0 on success, EOF on error
|
|
*/
|
|
static int gtmpqPutMsgBytes(const void* buf, size_t len, GTM_Conn* conn)
|
|
{
|
|
errno_t rc = EOK;
|
|
/* make sure there is room for it */
|
|
if (gtmpqCheckOutBufferSpace(conn->outMsgEnd + len, conn)) {
|
|
return EOF;
|
|
}
|
|
|
|
/* okay, save the data */
|
|
rc = memcpy_s(conn->outBuffer + conn->outMsgEnd, len, buf, len);
|
|
securec_check(rc, "\0", "\0");
|
|
conn->outMsgEnd += len;
|
|
|
|
/* no Pfdebug call here, caller should do it */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* gtmpqPutMsgEnd: finish constructing a message and possibly send it
|
|
*
|
|
* Returns 0 on success, EOF on error
|
|
*
|
|
* We don't actually send anything here unless we've accumulated at least
|
|
* 8K worth of data (the typical size of a pipe buffer on Unix systems).
|
|
* This avoids sending small partial packets. The caller must use gtmpqFlush
|
|
* when it's important to flush all the data out to the server.
|
|
*/
|
|
int gtmpqPutMsgEnd(GTM_Conn* conn)
|
|
{
|
|
errno_t rc = EOK;
|
|
if (conn->Pfdebug) {
|
|
fprintf(conn->Pfdebug, "To backend> Msg complete, length %d\n", conn->outMsgEnd - conn->outCount);
|
|
}
|
|
|
|
/* Fill in length word if needed */
|
|
if (conn->outMsgStart >= 0) {
|
|
uint32 msgLen = conn->outMsgEnd - conn->outMsgStart;
|
|
|
|
msgLen = htonl(msgLen);
|
|
rc = memcpy_s(conn->outBuffer + conn->outMsgStart, 4, &msgLen, 4);
|
|
securec_check(rc, "\0", "\0");
|
|
}
|
|
|
|
/* Make message eligible to send */
|
|
conn->outCount = conn->outMsgEnd;
|
|
|
|
if (conn->outCount >= 8192) {
|
|
int toSend = conn->outCount - (conn->outCount % 8192);
|
|
|
|
/* in nonblock mode, don't complain if unable to send it all */
|
|
if (gtmpqSendSome(conn, toSend) < 0) {
|
|
return EOF;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* ----------
|
|
* gtmpqReadData: read more data, if any is available
|
|
* Possible return values:
|
|
* 1: successfully loaded at least one more byte
|
|
* 0: no data is presently available, but no error detected
|
|
* -1: error detected (including EOF = connection closure);
|
|
* conn->errorMessage set
|
|
* NOTE: callers must not assume that pointers or indexes into conn->inBuffer
|
|
* remain valid across this call!
|
|
* ----------
|
|
*/
|
|
int gtmpqReadData(GTM_Conn* conn)
|
|
{
|
|
int someread = 0;
|
|
int nread;
|
|
errno_t rc = EOK;
|
|
|
|
if (conn->sock < 0) {
|
|
printfGTMPQExpBuffer(&conn->errorMessage, "connection not open\n");
|
|
return -1;
|
|
}
|
|
|
|
/* Left-justify any data in the buffer to make room */
|
|
if (conn->inStart < conn->inEnd) {
|
|
if (conn->inStart > 0) {
|
|
rc = memmove_s(conn->inBuffer, conn->inEnd - conn->inStart, conn->inBuffer + conn->inStart,
|
|
conn->inEnd - conn->inStart);
|
|
securec_check(rc, "\0", "\0");
|
|
conn->inEnd -= conn->inStart;
|
|
conn->inCursor -= conn->inStart;
|
|
conn->inStart = 0;
|
|
}
|
|
} else {
|
|
/* buffer is logically empty, reset it */
|
|
conn->inStart = conn->inCursor = conn->inEnd = 0;
|
|
}
|
|
|
|
/*
|
|
* If the buffer is fairly full, enlarge it. We need to be able to enlarge
|
|
* the buffer in case a single message exceeds the initial buffer size. We
|
|
* enlarge before filling the buffer entirely so as to avoid asking the
|
|
* kernel for a partial packet. The magic constant here should be large
|
|
* enough for a TCP packet or Unix pipe bufferload. 8K is the usual pipe
|
|
* buffer size, so...
|
|
* We don't insist that the enlarge worked, but we need some room
|
|
* errorMessage already set
|
|
*/
|
|
if (conn->inBufSize - conn->inEnd < 8192) {
|
|
if (gtmpqCheckInBufferSpace(conn->inEnd + (size_t)8192, conn)) {
|
|
if (conn->inBufSize - conn->inEnd < 100) {
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* OK, try to read some data */
|
|
retry3:
|
|
nread = recv(conn->sock, conn->inBuffer + conn->inEnd, conn->inBufSize - conn->inEnd, 0);
|
|
conn->last_call = GTM_LastCall_RECV;
|
|
if (nread < 0) {
|
|
conn->last_errno = SOCK_ERRNO;
|
|
|
|
if (SOCK_ERRNO == EINTR) {
|
|
goto retry3;
|
|
}
|
|
|
|
#ifdef EAGAIN
|
|
/* Some systems return EAGAIN/EWOULDBLOCK for no data */
|
|
if (SOCK_ERRNO == EAGAIN) {
|
|
return someread;
|
|
}
|
|
#endif
|
|
|
|
#if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
|
|
if (SOCK_ERRNO == EWOULDBLOCK) {
|
|
return someread;
|
|
}
|
|
#endif
|
|
|
|
#ifdef ECONNRESET
|
|
/* We might get ECONNRESET here if using TCP and backend died */
|
|
if (SOCK_ERRNO == ECONNRESET) {
|
|
goto definitelyFailed;
|
|
}
|
|
#endif
|
|
|
|
printfGTMPQExpBuffer(&conn->errorMessage, "could not receive data from server:\n");
|
|
return -1;
|
|
} else {
|
|
conn->last_errno = 0;
|
|
}
|
|
|
|
if (nread > 0) {
|
|
conn->inEnd += nread;
|
|
|
|
/*
|
|
* Hack to deal with the fact that some kernels will only give us back
|
|
* 1 packet per recv() call, even if we asked for more and there is
|
|
* more available. If it looks like we are reading a long message,
|
|
* loop back to recv() again immediately, until we run out of data or
|
|
* buffer space. Without this, the block-and-restart behavior of
|
|
* libpq's higher levels leads to O(N^2) performance on long messages.
|
|
*
|
|
* Since we left-justified the data above, conn->inEnd gives the
|
|
* amount of data already read in the current message. We consider
|
|
* the message "long" once we have acquired 32k ...
|
|
*/
|
|
#ifdef NOT_USED
|
|
if (conn->inEnd > 32768 && (conn->inBufSize - conn->inEnd) >= 8192) {
|
|
someread = 1;
|
|
goto retry3;
|
|
}
|
|
#endif
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* got a zero read after successful tries */
|
|
if (someread) {
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* A return value of 0 could mean just that no data is now available, or
|
|
* it could mean EOF --- that is, the server has closed the connection.
|
|
* Since we have the socket in nonblock mode, the only way to tell the
|
|
* difference is to see if select() is saying that the file is ready.
|
|
* Grumble. Fortunately, we don't expect this path to be taken much,
|
|
* since in normal practice we should not be trying to read data unless
|
|
* the file selected for reading already.
|
|
*
|
|
* In SSL mode it's even worse: SSL_read() could say WANT_READ and then
|
|
* data could arrive before we make the gtmpqReadReady() test. So we must
|
|
* play dumb and assume there is more data, relying on the SSL layer to
|
|
* detect true EOF.
|
|
*/
|
|
|
|
switch (gtmpqReadReady(conn)) {
|
|
case 0:
|
|
/* definitely no data available */
|
|
return 0;
|
|
case 1:
|
|
/* ready for read */
|
|
break;
|
|
default:
|
|
goto definitelyFailed;
|
|
}
|
|
|
|
/*
|
|
* Still not sure that it's EOF, because some data could have just
|
|
* arrived.
|
|
*/
|
|
retry4:
|
|
nread = recv(conn->sock, conn->inBuffer + conn->inEnd, conn->inBufSize - conn->inEnd, 0);
|
|
conn->last_call = GTM_LastCall_RECV;
|
|
if (nread < 0) {
|
|
conn->last_errno = SOCK_ERRNO;
|
|
|
|
/* Some systems return EAGAIN/EWOULDBLOCK for no data */
|
|
if (SOCK_ERRNO == EINTR) {
|
|
goto retry4;
|
|
}
|
|
|
|
#ifdef EAGAIN
|
|
if (SOCK_ERRNO == EAGAIN) {
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
|
|
if (SOCK_ERRNO == EWOULDBLOCK) {
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifdef ECONNRESET
|
|
/* We might get ECONNRESET here if using TCP and backend died */
|
|
if (SOCK_ERRNO == ECONNRESET) {
|
|
goto definitelyFailed;
|
|
}
|
|
#endif
|
|
printfGTMPQExpBuffer(&conn->errorMessage, "could not receive data from server: \n");
|
|
return -1;
|
|
} else {
|
|
conn->last_errno = 0;
|
|
}
|
|
|
|
if (nread > 0) {
|
|
conn->inEnd += nread;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* OK, we are getting a zero read even though select() says ready. This
|
|
* means the connection has been closed. Cope.
|
|
*/
|
|
definitelyFailed:
|
|
printfGTMPQExpBuffer(&conn->errorMessage,
|
|
"server closed the connection unexpectedly\n"
|
|
"\tThis probably means the server terminated abnormally\n"
|
|
"\tbefore or while processing the request.\n");
|
|
conn->status = CONNECTION_BAD; /* No more connection to backend */
|
|
close(conn->sock);
|
|
conn->sock = -1;
|
|
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* gtmpqSendSome: send data waiting in the output buffer.
|
|
*
|
|
* len is how much to try to send (typically equal to outCount, but may
|
|
* be less).
|
|
*
|
|
* Return 0 on success, -1 on failure and 1 when not all data could be sent
|
|
* because the socket would block and the connection is non-blocking.
|
|
*/
|
|
static int gtmpqSendSome(GTM_Conn* conn, int len)
|
|
{
|
|
char* ptr = conn->outBuffer;
|
|
int remaining = conn->outCount;
|
|
int result = 0;
|
|
errno_t rc = EOK;
|
|
|
|
if (conn->sock < 0) {
|
|
printfGTMPQExpBuffer(&conn->errorMessage, "connection not open\n");
|
|
return -1;
|
|
}
|
|
|
|
/* while there's still data to send */
|
|
while (len > 0) {
|
|
int sent;
|
|
|
|
sent = send(conn->sock, ptr, len, 0);
|
|
conn->last_call = GTM_LastCall_SEND;
|
|
|
|
if (sent < 0) {
|
|
conn->last_errno = SOCK_ERRNO;
|
|
/*
|
|
* Anything except EAGAIN/EWOULDBLOCK/EINTR is trouble. If it's
|
|
* EPIPE or ECONNRESET, assume we've lost the backend connection
|
|
* permanently.
|
|
*/
|
|
switch (SOCK_ERRNO) {
|
|
#ifdef EAGAIN
|
|
case EAGAIN:
|
|
break;
|
|
#endif
|
|
|
|
#if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
|
|
case EWOULDBLOCK:
|
|
break;
|
|
#endif
|
|
case EINTR:
|
|
continue;
|
|
|
|
case EPIPE:
|
|
#ifdef ECONNRESET
|
|
case ECONNRESET:
|
|
#endif
|
|
printfGTMPQExpBuffer(&conn->errorMessage,
|
|
"server closed the connection unexpectedly\n"
|
|
"\tThis probably means the server terminated abnormally\n"
|
|
"\tbefore or while processing the request.\n");
|
|
|
|
/*
|
|
* We used to close the socket here, but that's a bad idea
|
|
* since there might be unread data waiting (typically, a
|
|
* NOTICE message from the backend telling us it's
|
|
* committing hara-kiri...). Leave the socket open until
|
|
* gtmpqReadData finds no more data can be read. But abandon
|
|
* attempt to send data.
|
|
*/
|
|
conn->outCount = 0;
|
|
return -1;
|
|
|
|
default:
|
|
printfGTMPQExpBuffer(&conn->errorMessage, "could not send data to server: \n");
|
|
/* We don't assume it's a fatal error... */
|
|
conn->outCount = 0;
|
|
return -1;
|
|
}
|
|
} else {
|
|
ptr += sent;
|
|
len -= sent;
|
|
remaining -= sent;
|
|
conn->last_errno = 0;
|
|
}
|
|
|
|
if (len > 0) {
|
|
/*
|
|
* We didn't send it all, wait till we can send more.
|
|
*
|
|
* If the connection is in non-blocking mode we don't wait, but
|
|
* return 1 to indicate that data is still pending.
|
|
*/
|
|
result = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* shift the remaining contents of the buffer */
|
|
if (remaining > 0) {
|
|
rc = memmove_s(conn->outBuffer, remaining, ptr, remaining);
|
|
securec_check(rc, "\0", "\0");
|
|
}
|
|
|
|
conn->outCount = remaining;
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* gtmpqFlush: send any data waiting in the output buffer
|
|
*
|
|
* Return 0 on success, -1 on failure and 1 when not all data could be sent
|
|
* because the socket would block and the connection is non-blocking.
|
|
*/
|
|
int gtmpqFlush(GTM_Conn* conn)
|
|
{
|
|
if (conn->Pfdebug) {
|
|
fflush(conn->Pfdebug);
|
|
}
|
|
|
|
if (conn->outCount > 0) {
|
|
return gtmpqSendSome(conn, conn->outCount);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* gtmpqWait: wait until we can read or write the connection socket
|
|
*
|
|
* JAB: If SSL enabled and used and forRead, buffered bytes short-circuit the
|
|
* call to select().
|
|
*
|
|
* We also stop waiting and return if the kernel flags an exception condition
|
|
* on the socket. The actual error condition will be detected and reported
|
|
* when the caller tries to read or write the socket.
|
|
*/
|
|
int gtmpqWait(int forRead, int forWrite, GTM_Conn* conn)
|
|
{
|
|
return gtmpqWaitTimed(forRead, forWrite, conn, (time_t)-1);
|
|
}
|
|
|
|
/*
|
|
* gtmpqWaitTimed: wait, but not past finish_time.
|
|
*
|
|
* If finish_time is exceeded then we return failure (EOF). This is like
|
|
* the response for a kernel exception because we don't want the caller
|
|
* to try to read/write in that case.
|
|
*
|
|
* finish_time = ((time_t) -1) disables the wait limit.
|
|
*/
|
|
int gtmpqWaitTimed(int forRead, int forWrite, GTM_Conn* conn, time_t finish_time)
|
|
{
|
|
int result;
|
|
|
|
result = gtmpqSocketCheck(conn, forRead, forWrite, finish_time);
|
|
|
|
/* errorMessage is already set */
|
|
if (result < 0) {
|
|
return EOF;
|
|
}
|
|
|
|
if (result == 0) {
|
|
printfGTMPQExpBuffer(&conn->errorMessage, "timeout expired\n");
|
|
return EOF;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* gtmpqReadReady: is select() saying the file is ready to read?
|
|
* Returns -1 on failure, 0 if not ready, 1 if ready.
|
|
*/
|
|
int gtmpqReadReady(GTM_Conn* conn)
|
|
{
|
|
return gtmpqSocketCheck(conn, 1, 0, (time_t)0);
|
|
}
|
|
|
|
/*
|
|
* gtmpqWriteReady: is select() saying the file is ready to write?
|
|
* Returns -1 on failure, 0 if not ready, 1 if ready.
|
|
*/
|
|
int gtmpqWriteReady(GTM_Conn* conn)
|
|
{
|
|
return gtmpqSocketCheck(conn, 0, 1, (time_t)0);
|
|
}
|
|
|
|
/*
|
|
* Checks a socket, using poll or select, for data to be read, written,
|
|
* or both. Returns >0 if one or more conditions are met, 0 if it timed
|
|
* out, -1 if an error occurred.
|
|
*
|
|
* If SSL is in use, the SSL buffer is checked prior to checking the socket
|
|
* for read data directly.
|
|
*/
|
|
static int gtmpqSocketCheck(GTM_Conn* conn, int forRead, int forWrite, time_t end_time)
|
|
{
|
|
int result;
|
|
|
|
if (!conn) {
|
|
return -1;
|
|
}
|
|
|
|
if (conn->sock < 0) {
|
|
printfGTMPQExpBuffer(&conn->errorMessage, "socket not open\n");
|
|
return -1;
|
|
}
|
|
|
|
/* We will retry as long as we get EINTR */
|
|
do {
|
|
result = gtmpqSocketPoll(conn->sock, forRead, forWrite, end_time);
|
|
} while (result < 0 && SOCK_ERRNO == EINTR);
|
|
|
|
if (result < 0) {
|
|
printfGTMPQExpBuffer(&conn->errorMessage, "select() failed: \n");
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Check a file descriptor for read and/or write data, possibly waiting.
|
|
* If neither forRead nor forWrite are set, immediately return a timeout
|
|
* condition (without waiting). Return >0 if condition is met, 0
|
|
* if a timeout occurred, -1 if an error or interrupt occurred.
|
|
*
|
|
* Timeout is infinite if end_time is -1. Timeout is immediate (no blocking)
|
|
* if end_time is 0 (or indeed, any time before now).
|
|
*/
|
|
static int gtmpqSocketPoll(int sock, int forRead, int forWrite, time_t end_time)
|
|
{
|
|
/* We use poll(2) if available, otherwise select(2) */
|
|
#ifdef HAVE_POLL
|
|
struct pollfd input_fd;
|
|
int timeout_ms;
|
|
|
|
if (!forRead && !forWrite) {
|
|
return 0;
|
|
}
|
|
|
|
input_fd.fd = sock;
|
|
input_fd.events = POLLERR;
|
|
input_fd.revents = 0;
|
|
|
|
if (forRead) {
|
|
input_fd.events |= POLLIN;
|
|
}
|
|
|
|
if (forWrite) {
|
|
input_fd.events |= POLLOUT;
|
|
}
|
|
|
|
/* Compute appropriate timeout interval */
|
|
if (end_time == ((time_t)-1)) {
|
|
timeout_ms = -1;
|
|
} else {
|
|
time_t now = time(NULL);
|
|
|
|
if (end_time > now) {
|
|
timeout_ms = (end_time - now) * 1000;
|
|
} else {
|
|
timeout_ms = 0;
|
|
}
|
|
}
|
|
|
|
return poll(&input_fd, 1, timeout_ms);
|
|
#else /* !HAVE_POLL */
|
|
|
|
fd_set input_mask;
|
|
fd_set output_mask;
|
|
fd_set except_mask;
|
|
struct timeval timeout;
|
|
struct timeval* ptr_timeout;
|
|
|
|
if (!forRead && !forWrite) {
|
|
return 0;
|
|
}
|
|
|
|
FD_ZERO(&input_mask);
|
|
FD_ZERO(&output_mask);
|
|
FD_ZERO(&except_mask);
|
|
|
|
if (forRead) {
|
|
FD_SET(sock, &input_mask);
|
|
}
|
|
|
|
if (forWrite) {
|
|
FD_SET(sock, &output_mask);
|
|
}
|
|
|
|
FD_SET(sock, &except_mask);
|
|
|
|
/* Compute appropriate timeout interval */
|
|
if (end_time == ((time_t)-1)) {
|
|
ptr_timeout = NULL;
|
|
} else {
|
|
time_t now = time(NULL);
|
|
|
|
if (end_time > now) {
|
|
timeout.tv_sec = end_time - now;
|
|
} else {
|
|
timeout.tv_sec = 0;
|
|
}
|
|
|
|
timeout.tv_usec = 0;
|
|
ptr_timeout = &timeout;
|
|
}
|
|
|
|
return select(sock + 1, &input_mask, &output_mask, &except_mask, ptr_timeout);
|
|
#endif /* HAVE_POLL */
|
|
}
|