* Copyright (c) 2021 Huawei Technologies Co.,Ltd.
*
* CM is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2.
* You may obtain a copy of Mulan PSL v2 at:
*
* http://license.coscl.org.cn/MulanPSL2
*
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
* See the Mulan PSL v2 for more details.
* -------------------------------------------------------------------------
*
* fe-misc.cpp
*
*
* IDENTIFICATION
* src/cm_communication/cm_feconnect/fe-misc.cpp
*
* -------------------------------------------------------------------------
*/
#include "cm/cm_c.h"
#include <signal.h>
#include <time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/time.h>
#include <poll.h>
#include <sys/poll.h>
#include <sys/select.h>
#include "cm/libpq-fe.h"
#include "cm/libpq-int.h"
#include "cs_ssl.h"
#include "cm/cm_elog.h"
static int cmpqPutMsgBytes(const void* buf, size_t len, CM_Conn* conn);
static int cmpqSendSome(CM_Conn* conn, int len);
static int cmpqSocketCheck(CM_Conn* conn, int forRead, int forWrite, time_t end_time);
static int cmpqSocketPoll(int sock, int forRead, int forWrite, time_t end_time);
#define BYTES2 2
#define BYTES4 4
* cmpqGetc: get 1 character from the connection
*
* All these routines return 0 on success, EOF on error.
* Note that for the Get routines, EOF only means there is not enough
* data in the buffer, not that there is necessarily a hard error.
*/
int cmpqGetc(char* result, CM_Conn* conn)
{
if (conn->inCursor >= conn->inEnd) {
return EOF;
}
*result = conn->inBuffer[conn->inCursor++];
if (conn->Pfdebug != NULL) {
(void)fprintf(conn->Pfdebug, "From backend> %c\n", *result);
}
return 0;
}
* cmpqGets[_append]:
* get a null-terminated string from the connection,
* and store it in an expansible PQExpBuffer.
* If we run out of memory, all of the string is still read,
* but the excess characters are silently discarded.
*/
static int cmpqGets_internal(PQExpBuffer buf, CM_Conn* conn, bool resetbuffer)
{
char* inBuffer = conn->inBuffer;
int inCursor = conn->inCursor;
int inEnd = conn->inEnd;
int slen;
while (inCursor < inEnd && inBuffer[inCursor]) {
inCursor++;
}
if (inCursor >= inEnd) {
return EOF;
}
slen = inCursor - conn->inCursor;
if (resetbuffer) {
resetCMPQExpBuffer(buf);
}
appendBinaryCMPQExpBuffer(buf, inBuffer + conn->inCursor, (size_t)slen);
inCursor++;
conn->inCursor = inCursor;
if (conn->Pfdebug != NULL) {
(void)fprintf(conn->Pfdebug, "From backend> \"%s\"\n", buf->data);
}
return 0;
}
int cmpqGets(PQExpBuffer buf, CM_Conn* conn)
{
return cmpqGets_internal(buf, conn, true);
}
int cmpqGets_append(PQExpBuffer buf, CM_Conn* conn)
{
return cmpqGets_internal(buf, conn, false);
}
* cmpqPutnchar:
* write exactly len bytes to the current message
*/
int cmpqPutnchar(const char* s, size_t len, CM_Conn* conn)
{
if (cmpqPutMsgBytes(s, len, conn)) {
return EOF;
}
if (conn->Pfdebug != NULL) {
(void)fprintf(conn->Pfdebug, "To backend> %.*s\n", (int)len, s);
}
return 0;
}
* cmpqGetnchar:
* get a string of exactly len bytes in buffer s, no null termination
*/
int cmpqGetnchar(char* s, size_t len, CM_Conn* conn)
{
if (len > (size_t)(conn->inEnd - conn->inCursor)) {
return EOF;
}
errno_t rc = memcpy_s(s, len, conn->inBuffer + conn->inCursor, len);
securec_check_errno(rc, (void)rc);
conn->inCursor += (int)len;
if (conn->Pfdebug != NULL) {
(void)fprintf(conn->Pfdebug, "From backend (%lu)> %.*s\n", (unsigned long)len, (int)len, s);
}
return 0;
}
* cmpqGetInt
* read a 2 or 4 byte integer and convert from network byte order
* to local byte order
*/
int cmpqGetInt(int* result, size_t bytes, CM_Conn* conn)
{
uint16 tmp2;
uint32 tmp4;
errno_t rc;
switch (bytes) {
case 2:
if (conn->inCursor + BYTES2 > conn->inEnd) {
return EOF;
}
rc = memcpy_s(&tmp2, BYTES2, conn->inBuffer + conn->inCursor, BYTES2);
securec_check_errno(rc, (void)rc);
conn->inCursor += BYTES2;
*result = (int)ntohs(tmp2);
break;
case 4:
if (conn->inCursor + BYTES4 > conn->inEnd) {
return EOF;
}
rc = memcpy_s(&tmp4, BYTES4, conn->inBuffer + conn->inCursor, BYTES4);
securec_check_errno(rc, (void)rc);
conn->inCursor += BYTES4;
*result = (int)ntohl(tmp4);
break;
default:
if (conn->Pfdebug != NULL) {
(void)fprintf(conn->Pfdebug, "Integer size of (%lu) bytes not supported", bytes);
}
return EOF;
}
if (conn->Pfdebug != NULL) {
(void)fprintf(conn->Pfdebug, "From backend (#%lu)> %d\n", (unsigned long)bytes, *result);
}
return 0;
}
bool cmConnSetting(CM_Conn* conn, size_t bytes_needed, bool multi)
{
const int sizeDouble = 2;
const int size8K = 8192;
int newsize = conn->outBufSize;
char* newbuf = NULL;
if (multi) {
do {
newsize *= sizeDouble;
} while (newsize > 0 && bytes_needed > (size_t)newsize);
} else {
do {
newsize += size8K;
} while (newsize > 0 && bytes_needed > (size_t)newsize);
}
if (newsize > 0 && bytes_needed <= (size_t)newsize) {
newbuf = (char*)malloc((size_t)newsize);
if (newbuf != NULL) {
if (conn->outBuffer != NULL) {
errno_t rc = memcpy_s(newbuf, (size_t)newsize, conn->outBuffer, (size_t)conn->outBufSize);
securec_check_errno(rc, (void)rc);
FREE_AND_RESET(conn->outBuffer);
}
conn->outBuffer = newbuf;
conn->outBufSize = newsize;
return true;
}
}
return false;
}
* Make sure conn's output buffer can hold bytes_needed bytes (caller must
* include already-stored data into the value!)
*
* Returns 0 on success, EOF if failed to enlarge buffer
*/
int cmpqCheckOutBufferSpace(size_t bytes_needed, CM_Conn* conn)
{
if (bytes_needed <= (size_t)(conn->outBufSize)) {
return 0;
}
* If we need to enlarge the buffer, we first try to double it in size; if
* that doesn't work, enlarge in multiples of 8K. This avoids thrashing
* the malloc pool by repeated small enlargements.
*
* Note: tests for newsize > 0 are to catch integer overflow.
*/
if (cmConnSetting(conn, bytes_needed, true) || cmConnSetting(conn, bytes_needed, false)) {
return 0;
}
printfCMPQExpBuffer(&conn->errorMessage, "cannot allocate memory for output buffer\n");
return EOF;
}
* Make sure conn's input buffer can hold bytes_needed bytes (caller must
* include already-stored data into the value!)
*
* Returns 0 on success, EOF if failed to enlarge buffer
*/
int cmpqCheckInBufferSpace(size_t bytes_needed, CM_Conn* conn)
{
int newsize = conn->inBufSize;
char* newbuf = NULL;
if (bytes_needed <= (size_t)newsize) {
return 0;
}
do {
newsize *= 2;
} while (newsize > 0 && bytes_needed > (size_t)newsize);
if (newsize > 0 && bytes_needed <= (size_t)newsize) {
newbuf = (char*)malloc((size_t)newsize);
if (newbuf != NULL) {
if (conn->inBuffer != NULL) {
errno_t rc = memcpy_s(newbuf, (size_t)newsize, conn->inBuffer, (size_t)conn->inBufSize);
securec_check_errno(rc, (void)rc);
FREE_AND_RESET(conn->inBuffer);
}
conn->inBuffer = newbuf;
conn->inBufSize = newsize;
return 0;
}
}
newsize = conn->inBufSize;
do {
newsize += 8192;
} while (newsize > 0 && bytes_needed > (size_t)newsize);
if (newsize > 0 && bytes_needed <= (size_t)newsize) {
newbuf = (char*)malloc((size_t)newsize);
if (newbuf != NULL) {
if (conn->inBuffer != NULL) {
errno_t rc = memcpy_s(newbuf, (size_t)newsize, conn->inBuffer, (size_t)conn->inBufSize);
securec_check_errno(rc, (void)rc);
FREE_AND_RESET(conn->inBuffer);
}
conn->inBuffer = newbuf;
conn->inBufSize = newsize;
return 0;
}
}
printfCMPQExpBuffer(&conn->errorMessage, "cannot allocate memory for input buffer\n");
return EOF;
}
* cmpqPutMsgStart: begin construction of a message to the server
*
* msg_type is the message type byte, or 0 for a message without type byte
* (only startup messages have no type byte)
*
* force_len forces the message to have a length word; otherwise, we add
* a length word if protocol 3.
*
* Returns 0 on success, EOF on error
*
* The idea here is that we construct the message in conn->outBuffer,
* beginning just past any data already in outBuffer (ie, at
* outBuffer+outCount). We enlarge the buffer as needed to hold the message.
* When the message is complete, we fill in the length word (if needed) and
* then advance outCount past the message, making it eligible to send.
*
* The state variable conn->outMsgStart points to the incomplete message's
* length word: it is either outCount or outCount+1 depending on whether
* there is a type byte. If we are sending a message without length word
* (pre protocol 3.0 only), then outMsgStart is -1. The state variable
* conn->outMsgEnd is the end of the data collected so far.
*/
int cmpqPutMsgStart(char msg_type, bool force_len, CM_Conn* conn)
{
int lenPos;
int endPos;
if (msg_type) {
endPos = conn->outCount + 1;
} else {
endPos = conn->outCount;
}
if (force_len) {
lenPos = endPos;
endPos += 4;
} else {
lenPos = -1;
}
if (cmpqCheckOutBufferSpace((size_t)endPos, conn)) {
return EOF;
}
if (msg_type) {
conn->outBuffer[conn->outCount] = msg_type;
}
conn->outMsgStart = lenPos;
conn->outMsgEnd = endPos;
if (conn->Pfdebug != NULL) {
(void)fprintf(conn->Pfdebug, "To backend> Msg %c\n", msg_type ? msg_type : ' ');
}
return 0;
}
* cmpqPutMsgBytes: add bytes to a partially-constructed message
*
* Returns 0 on success, EOF on error
*/
static int cmpqPutMsgBytes(const void* buf, size_t len, CM_Conn* conn)
{
errno_t rc;
if (cmpqCheckOutBufferSpace((size_t)conn->outMsgEnd + len, conn)) {
return EOF;
}
rc = memcpy_s(conn->outBuffer + conn->outMsgEnd, (size_t)(conn->outBufSize - conn->outMsgEnd), buf, len);
securec_check_errno(rc, (void)rc);
conn->outMsgEnd += (int)len;
return 0;
}
* cmpqPutMsgEnd: 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 cmpqFlush
* when it's important to flush all the data out to the server.
*/
int cmpqPutMsgEnd(CM_Conn* conn)
{
if (conn->Pfdebug != NULL) {
(void)fprintf(conn->Pfdebug, "To backend> Msg complete, length %d\n", conn->outMsgEnd - conn->outCount);
}
if (conn->outMsgStart >= 0) {
uint32 msgLen = (uint32)(conn->outMsgEnd - conn->outMsgStart);
msgLen = htonl(msgLen);
errno_t rc = memcpy_s(conn->outBuffer + conn->outMsgStart, (size_t)(conn->outBufSize - conn->outMsgStart),
&msgLen, sizeof(uint32));
securec_check_errno(rc, (void)rc);
}
conn->outCount = conn->outMsgEnd;
if (conn->outCount >= 8192) {
int toSend = conn->outCount - (conn->outCount % 8192);
if (cmpqSendSome(conn, toSend) < 0) {
return EOF;
}
}
return 0;
}
* cmpqReadData: 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 cmpqReadData(CM_Conn* conn)
{
int someread = 0;
int nread = 0;
if (conn->sock < 0) {
printfCMPQExpBuffer(&conn->errorMessage, "connection not open\n");
return TCP_SOCKET_ERROR_EPIPE;
}
if (conn->inStart < conn->inEnd) {
if (conn->inStart > 0) {
errno_t rc;
rc = memmove_s(conn->inBuffer, (size_t)conn->inBufSize, conn->inBuffer + conn->inStart,
(size_t)(conn->inEnd - conn->inStart));
securec_check_errno(rc, (void)rc);
conn->inEnd -= conn->inStart;
conn->inCursor -= conn->inStart;
conn->inStart = 0;
}
} else {
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...
*/
if (conn->inBufSize - conn->inEnd < 8192) {
if (cmpqCheckInBufferSpace((size_t)(conn->inEnd + 8192), conn)) {
* We don't insist that the enlarge worked, but we need some room
*/
if (conn->inBufSize - conn->inEnd < 100) {
return TCP_SOCKET_ERROR_EPIPE;
}
}
}
retry3:
if (conn->pipe.type == CS_TYPE_SSL) {
uint32 event = 0;
status_t ret = cm_cs_ssl_recv(&conn->pipe.link.ssl, conn->inBuffer + conn->inEnd,
(uint32)(conn->inBufSize - conn->inEnd), &nread, &event);
if (ret != CM_SUCCESS) {
printfCMPQExpBuffer(&conn->errorMessage, "cm_cs_ssl_recv error, time is %ld.\n", time(NULL));
return -1;
}
conn->last_errno = 0;
conn->inEnd += nread;
conn->last_call = (int)CM_LastCall_RECV;
if (nread == 0) {
return 0;
} else {
return 1;
}
} else {
nread = (int)recv(conn->sock, conn->inBuffer + conn->inEnd, (size_t)(conn->inBufSize - conn->inEnd),
(int)MSG_DONTWAIT);
}
conn->last_call = (int)CM_LastCall_RECV;
if (nread < 0) {
conn->last_errno = SOCK_ERRNO;
if (SOCK_ERRNO == EINTR) {
goto retry3;
}
#ifdef EAGAIN
if (SOCK_ERRNO == EAGAIN) {
return someread;
}
#endif
#if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
if (SOCK_ERRNO == EWOULDBLOCK) {
return someread;
}
#endif
#ifdef ECONNRESET
if (SOCK_ERRNO == ECONNRESET) {
goto definitelyFailed;
}
#endif
printfCMPQExpBuffer(&conn->errorMessage, "could not receive data from server:\n");
return TCP_SOCKET_ERROR_EPIPE;
} 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;
}
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 cmpqReadReady() test. So we must
* play dumb and assume there is more data, relying on the SSL layer to
* detect true EOF.
*/
switch (cmpqReadReady(conn)) {
case 0:
return 0;
case 1:
break;
default:
goto definitelyFailed;
}
* Still not sure that it's EOF, because some data could have just
* arrived.
*/
retry4:
if (conn->pipe.type == CS_TYPE_SSL) {
uint32 event = 0;
status_t ret = cm_cs_ssl_recv(&conn->pipe.link.ssl, conn->inBuffer + conn->inEnd,
(uint32)(conn->inBufSize - conn->inEnd), &nread, &event);
if (ret != CM_SUCCESS) {
printfCMPQExpBuffer(&conn->errorMessage, "cm_cs_ssl_recv error, time is %ld.\n", time(NULL));
return -1;
}
conn->last_errno = 0;
conn->inEnd += nread;
conn->last_call = (int)CM_LastCall_RECV;
return 1;
} else {
nread = (int)recv(conn->sock, conn->inBuffer + conn->inEnd, (size_t)(conn->inBufSize - conn->inEnd),
(int)MSG_DONTWAIT);
}
conn->last_call = (int)CM_LastCall_RECV;
if (nread < 0) {
conn->last_errno = SOCK_ERRNO;
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
if (SOCK_ERRNO == ECONNRESET) {
goto definitelyFailed;
}
#endif
printfCMPQExpBuffer(&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:
printfCMPQExpBuffer(&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;
(void)close(conn->sock);
conn->sock = -1;
return TCP_SOCKET_ERROR_EPIPE;
}
* cmpqSendSome: 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 cmpqSendSome(CM_Conn* conn, int len)
{
char* ptr = conn->outBuffer;
int remaining = conn->outCount;
int result = 0;
if (conn->sock < 0) {
printfCMPQExpBuffer(&conn->errorMessage, "connection not open\n");
return TCP_SOCKET_ERROR_EPIPE;
}
while (len > 0) {
int sent;
if (conn->pipe.type == CS_TYPE_SSL) {
status_t ret = cm_cs_ssl_send_timed(&conn->pipe.link.ssl, ptr, (uint32)len, CM_NETWORK_SEND_TIMEOUT);
if (ret != CM_SUCCESS) {
printfCMPQExpBuffer(&conn->errorMessage, "cm_cs_ssl_send_timed error, time is %ld.\n", time(NULL));
return -1;
}
conn->outCount = 0;
conn->last_errno = 0;
conn->last_call = (int)CM_LastCall_SEND;
return 0;
} else {
sent = (int)send(conn->sock, ptr, (size_t)len, (int)MSG_DONTWAIT);
}
conn->last_call = (int)CM_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
printfCMPQExpBuffer(&conn->errorMessage,
"server closed the connection unexpectedly\n"
"\tThis probably means the server terminated abnormally\n"
"\tbefore or while processing the request. errno:%d\n",
SOCK_ERRNO);
* 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
* cmpqReadData finds no more data can be read. But abandon
* attempt to send data.
*/
conn->outCount = 0;
return TCP_SOCKET_ERROR_EPIPE;
default:
printfCMPQExpBuffer(&conn->errorMessage, "could not send data to server: \n");
conn->outCount = 0;
return TCP_SOCKET_ERROR_EPIPE;
}
} 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;
}
}
if (remaining > 0) {
errno_t rc = memmove_s(conn->outBuffer, (size_t)conn->outBufSize, ptr, (size_t)remaining);
securec_check_errno(rc, (void)rc);
}
conn->outCount = remaining;
return result;
}
* cmpqFlush: 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 cmpqFlush(CM_Conn* conn)
{
if (conn->Pfdebug != NULL) {
(void)fflush(conn->Pfdebug);
}
if (conn->outCount > 0) {
return cmpqSendSome(conn, conn->outCount);
}
return 0;
}
* cmpqWait: 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 cmpqWait(int forRead, int forWrite, CM_Conn* conn)
{
return cmpqWaitTimed(forRead, forWrite, conn, time(NULL) + 5);
}
* cmpqWaitTimed: 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 cmpqWaitTimed(int forRead, int forWrite, CM_Conn* conn, time_t finish_time)
{
int result = cmpqSocketCheck(conn, forRead, forWrite, finish_time);
if (result < 0) {
return EOF;
}
if (result == 0) {
printfCMPQExpBuffer(&conn->errorMessage, "timeout expired\n");
return EOF;
}
return 0;
}
* cmpqReadReady: is select() saying the file is ready to read?
* Returns -1 on failure, 0 if not ready, 1 if ready.
*/
int cmpqReadReady(CM_Conn* conn)
{
return cmpqSocketCheck(conn, 1, 0, (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 cmpqSocketCheck(CM_Conn* conn, int forRead, int forWrite, time_t end_time)
{
int result;
if (conn == NULL) {
return TCP_SOCKET_ERROR_EPIPE;
}
if (conn->sock < 0) {
printfCMPQExpBuffer(&conn->errorMessage, "socket not open\n");
return TCP_SOCKET_ERROR_EPIPE;
}
do {
result = cmpqSocketPoll(conn->sock, forRead, forWrite, end_time);
} while (result < 0 && SOCK_ERRNO == EINTR);
if (result < 0) {
printfCMPQExpBuffer(&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 cmpqSocketPoll(int sock, int forRead, int forWrite, time_t end_time)
{
#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;
}
if (end_time == ((time_t)-1)) {
timeout_ms = -1;
} else {
time_t now = time(NULL);
if (end_time > now) {
timeout_ms = (int)(end_time - now) * 1000;
} else {
timeout_ms = 0;
}
}
return poll(&input_fd, 1, timeout_ms);
#else
fd_set input_mask;
fd_set output_mask;
fd_set except_mask;
struct timeval timeout;
struct timeval* ptr_timeout = NULL;
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);
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
}