| /*------------------------------------------------------------------------- |
| * |
| * FILE |
| * fe-misc.c |
| * |
| * DESCRIPTION |
| * miscellaneous useful functions |
| * |
| * The communication routines here are analogous to the ones in |
| * backend/libpq/pqcomm.c and backend/libpq/pqcomprim.c, but operate |
| * in the considerably different environment of the frontend libpq. |
| * In particular, we work with a bare nonblock-mode socket, rather than |
| * a stdio stream, so that we can avoid unwanted blocking of the application. |
| * |
| * XXX: MOVE DEBUG PRINTOUT TO HIGHER LEVEL. As is, block and restart |
| * will cause repeat printouts. |
| * |
| * We must speak the same transmitted data representations as the backend |
| * routines. |
| * |
| * |
| * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group |
| * Portions Copyright (c) 1994, Regents of the University of California |
| * |
| * IDENTIFICATION |
| * $PostgreSQL: pgsql/src/interfaces/libpq/fe-misc.c,v 1.144 2010/07/06 19:19:01 momjian Exp $ |
| * |
| *------------------------------------------------------------------------- |
| */ |
| |
| #include "postgres_fe.h" |
| |
| #include <signal.h> |
| #include <time.h> |
| |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| |
| #ifdef WIN32 |
| #include "win32.h" |
| #else |
| #include <unistd.h> |
| #include <sys/time.h> |
| #endif |
| |
| #ifdef HAVE_POLL_H |
| #include <poll.h> |
| #endif |
| #ifdef HAVE_SYS_POLL_H |
| #include <sys/poll.h> |
| #endif |
| #ifdef HAVE_SYS_SELECT_H |
| #include <sys/select.h> |
| #endif |
| |
| #include "libpq-fe.h" |
| #include "libpq-int.h" |
| #include "pqsignal.h" |
| #include "mb/pg_wchar.h" |
| #include "pg_config_paths.h" |
| |
| |
| static int pqPutMsgBytes(const void *buf, size_t len, PGconn *conn); |
| static int pqSendSome(PGconn *conn, int len); |
| static int pqSocketCheck(PGconn *conn, int forRead, int forWrite, |
| time_t end_time); |
| static int pqSocketPoll(int sock, int forRead, int forWrite, time_t end_time); |
| |
| |
| /* |
| * fputnbytes: print exactly N bytes to a file |
| * |
| * We avoid using %.*s here because it can misbehave if the data |
| * is not valid in what libc thinks is the prevailing encoding. |
| */ |
| static void |
| fputnbytes(FILE *f, const char *str, size_t n) |
| { |
| while (n-- > 0) |
| fputc(*str++, f); |
| } |
| |
| |
| /* |
| * pqGetc: 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 |
| pqGetc(char *result, PGconn *conn) |
| { |
| if (conn->inCursor >= conn->inEnd) |
| return EOF; |
| |
| *result = conn->inBuffer[conn->inCursor++]; |
| |
| if (conn->Pfdebug) |
| fprintf(conn->Pfdebug, "From backend> %c\n", *result); |
| |
| return 0; |
| } |
| |
| |
| /* |
| * pqPutc: write 1 char to the current message |
| */ |
| int |
| pqPutc(char c, PGconn *conn) |
| { |
| if (pqPutMsgBytes(&c, 1, conn)) |
| return EOF; |
| |
| if (conn->Pfdebug) |
| fprintf(conn->Pfdebug, "To backend> %c\n", c); |
| |
| return 0; |
| } |
| |
| |
| /* |
| * pqGets[_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 |
| pqGets_internal(PQExpBuffer buf, PGconn *conn, bool resetbuffer) |
| { |
| /* Copy conn data to locals for faster search loop */ |
| 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) |
| resetPQExpBuffer(buf); |
| |
| appendBinaryPQExpBuffer(buf, inBuffer + conn->inCursor, slen); |
| |
| conn->inCursor = ++inCursor; |
| |
| if (conn->Pfdebug) |
| fprintf(conn->Pfdebug, "From backend> \"%s\"\n", |
| buf->data); |
| |
| return 0; |
| } |
| |
| int |
| pqGets(PQExpBuffer buf, PGconn *conn) |
| { |
| return pqGets_internal(buf, conn, true); |
| } |
| |
| int |
| pqGets_append(PQExpBuffer buf, PGconn *conn) |
| { |
| return pqGets_internal(buf, conn, false); |
| } |
| |
| |
| /* |
| * pqPuts: write a null-terminated string to the current message |
| */ |
| int |
| pqPuts(const char *s, PGconn *conn) |
| { |
| if (pqPutMsgBytes(s, strlen(s) + 1, conn)) |
| return EOF; |
| |
| if (conn->Pfdebug) |
| fprintf(conn->Pfdebug, "To backend> \"%s\"\n", s); |
| |
| return 0; |
| } |
| |
| /* |
| * pqGetnchar: |
| * get a string of exactly len bytes in buffer s, no null termination |
| */ |
| int |
| pqGetnchar(char *s, size_t len, PGconn *conn) |
| { |
| if (len > (size_t) (conn->inEnd - conn->inCursor)) |
| return EOF; |
| |
| memcpy(s, conn->inBuffer + conn->inCursor, len); |
| /* no terminating null */ |
| |
| conn->inCursor += len; |
| |
| if (conn->Pfdebug) |
| { |
| fprintf(conn->Pfdebug, "From backend (%lu)> ", (unsigned long) len); |
| fputnbytes(conn->Pfdebug, s, len); |
| fprintf(conn->Pfdebug, "\n"); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * pqPutnchar: |
| * write exactly len bytes to the current message |
| */ |
| int |
| pqPutnchar(const char *s, size_t len, PGconn *conn) |
| { |
| if (pqPutMsgBytes(s, len, conn)) |
| return EOF; |
| |
| if (conn->Pfdebug) |
| { |
| fprintf(conn->Pfdebug, "To backend> "); |
| fputnbytes(conn->Pfdebug, s, len); |
| fprintf(conn->Pfdebug, "\n"); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * pqGetInt |
| * read a 2 or 4 byte integer and convert from network byte order |
| * to local byte order |
| */ |
| int |
| pqGetInt(int *result, size_t bytes, PGconn *conn) |
| { |
| uint16 tmp2; |
| uint32 tmp4; |
| |
| switch (bytes) |
| { |
| case 2: |
| if (conn->inCursor + 2 > conn->inEnd) |
| return EOF; |
| memcpy(&tmp2, conn->inBuffer + conn->inCursor, 2); |
| conn->inCursor += 2; |
| *result = (int) ntohs(tmp2); |
| break; |
| case 4: |
| if (conn->inCursor + 4 > conn->inEnd) |
| return EOF; |
| memcpy(&tmp4, conn->inBuffer + conn->inCursor, 4); |
| conn->inCursor += 4; |
| *result = (int) ntohl(tmp4); |
| break; |
| default: |
| pqInternalNotice(&conn->noticeHooks, |
| "integer of size %lu not supported by pqGetInt", |
| (unsigned long) bytes); |
| return EOF; |
| } |
| |
| if (conn->Pfdebug) |
| fprintf(conn->Pfdebug, "From backend (#%lu)> %d\n", (unsigned long) bytes, *result); |
| |
| return 0; |
| } |
| |
| /* |
| * pqPutInt |
| * write an integer of 2 or 4 bytes, converting from host byte order |
| * to network byte order. |
| */ |
| int |
| pqPutInt(int value, size_t bytes, PGconn *conn) |
| { |
| uint16 tmp2; |
| uint32 tmp4; |
| |
| switch (bytes) |
| { |
| case 2: |
| tmp2 = htons((uint16) value); |
| if (pqPutMsgBytes((const char *) &tmp2, 2, conn)) |
| return EOF; |
| break; |
| case 4: |
| tmp4 = htonl((uint32) value); |
| if (pqPutMsgBytes((const char *) &tmp4, 4, conn)) |
| return EOF; |
| break; |
| default: |
| pqInternalNotice(&conn->noticeHooks, |
| "integer of size %lu not supported by pqPutInt", |
| (unsigned long) bytes); |
| return EOF; |
| } |
| |
| if (conn->Pfdebug) |
| fprintf(conn->Pfdebug, "To backend (%lu#)> %d\n", (unsigned long) bytes, value); |
| |
| return 0; |
| } |
| |
| /* |
| * 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 |
| pqCheckOutBufferSpace(size_t bytes_needed, PGconn *conn) |
| { |
| int newsize = conn->outBufSize; |
| char *newbuf; |
| |
| if (bytes_needed <= (size_t) newsize) |
| 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. |
| */ |
| do |
| { |
| newsize *= 2; |
| } while (newsize > 0 && bytes_needed > (size_t) newsize); |
| |
| if (newsize > 0 && bytes_needed <= (size_t) newsize) |
| { |
| newbuf = realloc(conn->outBuffer, newsize); |
| if (newbuf) |
| { |
| /* realloc succeeded */ |
| conn->outBuffer = newbuf; |
| conn->outBufSize = newsize; |
| return 0; |
| } |
| } |
| |
| newsize = conn->outBufSize; |
| do |
| { |
| newsize += 8192; |
| } while (newsize > 0 && bytes_needed > (size_t) newsize); |
| |
| if (newsize > 0 && bytes_needed <= (size_t) newsize) |
| { |
| newbuf = realloc(conn->outBuffer, newsize); |
| if (newbuf) |
| { |
| /* realloc succeeded */ |
| conn->outBuffer = newbuf; |
| conn->outBufSize = newsize; |
| return 0; |
| } |
| } |
| |
| /* realloc failed. Probably out of memory */ |
| printfPQExpBuffer(&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 |
| pqCheckInBufferSpace(size_t bytes_needed, PGconn *conn) |
| { |
| int newsize = conn->inBufSize; |
| char *newbuf; |
| |
| if (bytes_needed <= (size_t) newsize) |
| 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. |
| */ |
| do |
| { |
| newsize *= 2; |
| } while (newsize > 0 && bytes_needed > (size_t) newsize); |
| |
| if (newsize > 0 && bytes_needed <= (size_t) newsize) |
| { |
| newbuf = realloc(conn->inBuffer, newsize); |
| if (newbuf) |
| { |
| /* realloc succeeded */ |
| 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 = realloc(conn->inBuffer, newsize); |
| if (newbuf) |
| { |
| /* realloc succeeded */ |
| conn->inBuffer = newbuf; |
| conn->inBufSize = newsize; |
| return 0; |
| } |
| } |
| |
| /* realloc failed. Probably out of memory */ |
| printfPQExpBuffer(&conn->errorMessage, |
| "cannot allocate memory for input buffer\n"); |
| return EOF; |
| } |
| |
| /* |
| * pqPutMsgStart: 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 |
| pqPutMsgStart(char msg_type, bool force_len, PGconn *conn) |
| { |
| int lenPos; |
| int endPos; |
| |
| /* allow room for message type byte */ |
| if (msg_type) |
| endPos = conn->outCount + 1; |
| else |
| endPos = conn->outCount; |
| |
| /* do we want a length word? */ |
| if (force_len || PG_PROTOCOL_MAJOR(conn->pversion) >= 3) |
| { |
| lenPos = endPos; |
| /* allow room for message length */ |
| endPos += 4; |
| } |
| else |
| lenPos = -1; |
| |
| /* make sure there is room for message header */ |
| if (pqCheckOutBufferSpace(endPos, conn)) |
| return EOF; |
| /* okay, save the message type byte if any */ |
| if (msg_type) |
| conn->outBuffer[conn->outCount] = msg_type; |
| /* set up the message pointers */ |
| conn->outMsgStart = lenPos; |
| conn->outMsgEnd = endPos; |
| /* length word, if needed, will be filled in by pqPutMsgEnd */ |
| |
| if (conn->Pfdebug) |
| fprintf(conn->Pfdebug, "To backend> Msg %c\n", |
| msg_type ? msg_type : ' '); |
| |
| return 0; |
| } |
| |
| /* |
| * pqPutMsgBytes: add bytes to a partially-constructed message |
| * |
| * Returns 0 on success, EOF on error |
| */ |
| static int |
| pqPutMsgBytes(const void *buf, size_t len, PGconn *conn) |
| { |
| /* make sure there is room for it */ |
| if (pqCheckOutBufferSpace(conn->outMsgEnd + len, conn)) |
| return EOF; |
| /* okay, save the data */ |
| memcpy(conn->outBuffer + conn->outMsgEnd, buf, len); |
| conn->outMsgEnd += len; |
| /* no Pfdebug call here, caller should do it */ |
| return 0; |
| } |
| |
| /* |
| * pqPutMsgEnd: 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 pqFlush |
| * when it's important to flush all the data out to the server. |
| */ |
| int |
| pqPutMsgEnd(PGconn *conn) |
| { |
| if (conn->Pfdebug) |
| fprintf(conn->Pfdebug, "To backend> Msg complete, length %u\n", |
| conn->outMsgEnd - conn->outCount); |
| |
| /* Fill in length word if needed */ |
| if (conn->outMsgStart >= 0) |
| { |
| uint32 msgLen = conn->outMsgEnd - conn->outMsgStart; |
| |
| msgLen = htonl(msgLen); |
| memcpy(conn->outBuffer + conn->outMsgStart, &msgLen, 4); |
| } |
| |
| /* Make message eligible to send */ |
| conn->outCount = conn->outMsgEnd; |
| |
| if (conn->outCount >= 8192) |
| { |
| int toSend = conn->outCount - (conn->outCount % 8192); |
| |
| if (pqSendSome(conn, toSend) < 0) |
| return EOF; |
| /* in nonblock mode, don't complain if unable to send it all */ |
| } |
| |
| return 0; |
| } |
| |
| /* ---------- |
| * pqReadData: 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 |
| pqReadData(PGconn *conn) |
| { |
| int someread = 0; |
| int nread; |
| char sebuf[256]; |
| |
| if (conn->sock < 0) |
| { |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext("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) |
| { |
| memmove(conn->inBuffer, conn->inBuffer + conn->inStart, |
| conn->inEnd - conn->inStart); |
| 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... |
| */ |
| if (conn->inBufSize - conn->inEnd < 8192) |
| { |
| if (pqCheckInBufferSpace(conn->inEnd + (size_t) 8192, conn)) |
| { |
| /* |
| * We don't insist that the enlarge worked, but we need some room |
| */ |
| if (conn->inBufSize - conn->inEnd < 100) |
| return -1; /* errorMessage already set */ |
| } |
| } |
| |
| /* OK, try to read some data */ |
| retry3: |
| nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd, |
| conn->inBufSize - conn->inEnd); |
| if (nread < 0) |
| { |
| if (SOCK_ERRNO == EINTR) |
| goto retry3; |
| /* Some systems return EAGAIN/EWOULDBLOCK for no data */ |
| #ifdef EAGAIN |
| if (SOCK_ERRNO == EAGAIN) |
| return someread; |
| #endif |
| #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN)) |
| if (SOCK_ERRNO == EWOULDBLOCK) |
| return someread; |
| #endif |
| /* We might get ECONNRESET here if using TCP and backend died */ |
| #ifdef ECONNRESET |
| if (SOCK_ERRNO == ECONNRESET) |
| goto definitelyFailed; |
| #endif |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext("could not receive data from server: %s\n"), |
| SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); |
| return -1; |
| } |
| 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 ... |
| */ |
| if (conn->inEnd > 32768 && |
| (conn->inBufSize - conn->inEnd) >= 8192) |
| { |
| someread = 1; |
| goto retry3; |
| } |
| return 1; |
| } |
| |
| if (someread) |
| return 1; /* got a zero read after successful tries */ |
| |
| /* |
| * 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 pqReadReady() test. So we must |
| * play dumb and assume there is more data, relying on the SSL layer to |
| * detect true EOF. |
| */ |
| |
| #ifdef USE_SSL |
| if (conn->ssl) |
| return 0; |
| #endif |
| |
| switch (pqReadReady(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 = pqsecure_read(conn, conn->inBuffer + conn->inEnd, |
| conn->inBufSize - conn->inEnd); |
| if (nread < 0) |
| { |
| if (SOCK_ERRNO == EINTR) |
| goto retry4; |
| /* Some systems return EAGAIN/EWOULDBLOCK for no data */ |
| #ifdef EAGAIN |
| if (SOCK_ERRNO == EAGAIN) |
| return 0; |
| #endif |
| #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN)) |
| if (SOCK_ERRNO == EWOULDBLOCK) |
| return 0; |
| #endif |
| /* We might get ECONNRESET here if using TCP and backend died */ |
| #ifdef ECONNRESET |
| if (SOCK_ERRNO == ECONNRESET) |
| goto definitelyFailed; |
| #endif |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext("could not receive data from server: %s\n"), |
| SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); |
| return -1; |
| } |
| 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: |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext( |
| "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 */ |
| pqsecure_close(conn); |
| closesocket(conn->sock); |
| conn->sock = -1; |
| |
| return -1; |
| } |
| |
| /* |
| * pqSendSome: 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 |
| pqSendSome(PGconn *conn, int len) |
| { |
| char *ptr = conn->outBuffer; |
| int remaining = conn->outCount; |
| int result = 0; |
| |
| if (conn->sock < 0) |
| { |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext("connection not open\n")); |
| return -1; |
| } |
| |
| /* while there's still data to send */ |
| while (len > 0) |
| { |
| int sent; |
| char sebuf[256]; |
| |
| #ifndef WIN32 |
| sent = pqsecure_write(conn, ptr, len); |
| #else |
| |
| /* |
| * Windows can fail on large sends, per KB article Q201213. The |
| * failure-point appears to be different in different versions of |
| * Windows, but 64k should always be safe. |
| */ |
| sent = pqsecure_write(conn, ptr, Min(len, 65536)); |
| #endif |
| |
| if (sent < 0) |
| { |
| /* |
| * 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 |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext( |
| "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 |
| * pqReadData finds no more data can be read. But abandon |
| * attempt to send data. |
| */ |
| conn->outCount = 0; |
| return -1; |
| |
| default: |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext("could not send data to server: %s\n"), |
| SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); |
| /* We don't assume it's a fatal error... */ |
| conn->outCount = 0; |
| return -1; |
| } |
| } |
| else |
| { |
| ptr += sent; |
| len -= sent; |
| remaining -= sent; |
| } |
| |
| 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. |
| */ |
| if (pqIsnonblocking(conn)) |
| { |
| result = 1; |
| break; |
| } |
| |
| /* |
| * There are scenarios in which we can't send data because the |
| * communications channel is full, but we cannot expect the server |
| * to clear the channel eventually because it's blocked trying to |
| * send data to us. (This can happen when we are sending a large |
| * amount of COPY data, and the server has generated lots of |
| * NOTICE responses.) To avoid a deadlock situation, we must be |
| * prepared to accept and buffer incoming data before we try |
| * again. Furthermore, it is possible that such incoming data |
| * might not arrive until after we've gone to sleep. Therefore, |
| * we wait for either read ready or write ready. |
| */ |
| if (pqReadData(conn) < 0) |
| { |
| result = -1; /* error message already set up */ |
| break; |
| } |
| if (pqWait(TRUE, TRUE, conn)) |
| { |
| result = -1; |
| break; |
| } |
| } |
| } |
| |
| /* shift the remaining contents of the buffer */ |
| if (remaining > 0) |
| memmove(conn->outBuffer, ptr, remaining); |
| conn->outCount = remaining; |
| |
| return result; |
| } |
| |
| |
| /* |
| * pqFlush: 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 |
| pqFlush(PGconn *conn) |
| { |
| if (conn->Pfdebug) |
| fflush(conn->Pfdebug); |
| |
| if (conn->outCount > 0) |
| return pqSendSome(conn, conn->outCount); |
| |
| return 0; |
| } |
| |
| |
| /* |
| * pqWait: 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 |
| pqWait(int forRead, int forWrite, PGconn *conn) |
| { |
| return pqWaitTimed(forRead, forWrite, conn, (time_t) -1); |
| } |
| |
| /* |
| * pqWaitTimed: 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 |
| pqWaitTimed(int forRead, int forWrite, PGconn *conn, time_t finish_time) |
| { |
| int result; |
| |
| result = pqSocketCheck(conn, forRead, forWrite, finish_time); |
| |
| if (result < 0) |
| return EOF; /* errorMessage is already set */ |
| |
| if (result == 0) |
| { |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext("timeout expired\n")); |
| return EOF; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * pqReadReady: is select() saying the file is ready to read? |
| * Returns -1 on failure, 0 if not ready, 1 if ready. |
| */ |
| int |
| pqReadReady(PGconn *conn) |
| { |
| return pqSocketCheck(conn, 1, 0, (time_t) 0); |
| } |
| |
| /* |
| * pqWriteReady: is select() saying the file is ready to write? |
| * Returns -1 on failure, 0 if not ready, 1 if ready. |
| */ |
| int |
| pqWriteReady(PGconn *conn) |
| { |
| return pqSocketCheck(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 |
| pqSocketCheck(PGconn *conn, int forRead, int forWrite, time_t end_time) |
| { |
| int result; |
| |
| if (!conn) |
| return -1; |
| if (conn->sock < 0) |
| { |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext("socket not open\n")); |
| return -1; |
| } |
| |
| #ifdef USE_SSL |
| /* Check for SSL library buffering read bytes */ |
| if (forRead && conn->ssl && SSL_pending(conn->ssl) > 0) |
| { |
| /* short-circuit the select */ |
| return 1; |
| } |
| #endif |
| |
| /* We will retry as long as we get EINTR */ |
| do |
| result = pqSocketPoll(conn->sock, forRead, forWrite, end_time); |
| while (result < 0 && SOCK_ERRNO == EINTR); |
| |
| if (result < 0) |
| { |
| char sebuf[256]; |
| |
| printfPQExpBuffer(&conn->errorMessage, |
| libpq_gettext("select() failed: %s\n"), |
| SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); |
| } |
| |
| 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 |
| pqSocketPoll(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 */ |
| } |
| |
| |
| /* |
| * A couple of "miscellaneous" multibyte related functions. They used |
| * to be in fe-print.c but that file is doomed. |
| */ |
| |
| /* |
| * returns the byte length of the word beginning s, using the |
| * specified encoding. |
| */ |
| int |
| PQmblen(const char *s, int encoding) |
| { |
| return pg_encoding_mblen(encoding, s); |
| } |
| |
| /* |
| * returns the display length of the word beginning s, using the |
| * specified encoding. |
| */ |
| int |
| PQdsplen(const char *s, int encoding) |
| { |
| return pg_encoding_dsplen(encoding, s); |
| } |
| |
| /* |
| * Get encoding id from environment variable PGCLIENTENCODING. |
| */ |
| int |
| PQenv2encoding(void) |
| { |
| char *str; |
| int encoding = PG_SQL_ASCII; |
| |
| str = getenv("PGCLIENTENCODING"); |
| if (str && *str != '\0') |
| { |
| encoding = pg_char_to_encoding(str); |
| if (encoding < 0) |
| encoding = PG_SQL_ASCII; |
| } |
| return encoding; |
| } |
| |
| |
| #ifdef ENABLE_NLS |
| |
| char * |
| libpq_gettext(const char *msgid) |
| { |
| static bool already_bound = false; |
| |
| if (!already_bound) |
| { |
| /* dgettext() preserves errno, but bindtextdomain() doesn't */ |
| #ifdef WIN32 |
| int save_errno = GetLastError(); |
| #else |
| int save_errno = errno; |
| #endif |
| const char *ldir; |
| |
| already_bound = true; |
| /* No relocatable lookup here because the binary could be anywhere */ |
| ldir = getenv("PGLOCALEDIR"); |
| if (!ldir) |
| ldir = LOCALEDIR; |
| bindtextdomain(PG_TEXTDOMAIN("libpq"), ldir); |
| #ifdef WIN32 |
| SetLastError(save_errno); |
| #else |
| errno = save_errno; |
| #endif |
| } |
| |
| return dgettext(PG_TEXTDOMAIN("libpq"), msgid); |
| } |
| |
| #endif /* ENABLE_NLS */ |