/*------------------------------------------------------------------------- * * fe-protocol3.c * functions that are specific to frontend/backend protocol version 3 * * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/interfaces/libpq/fe-protocol3.c * *------------------------------------------------------------------------- */ #include "postgres_fe.h" #include #include #include "libpq-fe.h" #include "libpq-int.h" #include "mb/pg_wchar.h" #ifdef WIN32 #include "win32.h" #else #include #include #ifdef HAVE_NETINET_TCP_H #include #endif #include #endif /* * This macro lists the backend message types that could be "long" (more * than a couple of kilobytes). */ #define VALID_LONG_MESSAGE_TYPE(id) \ ((id) == 'T' || (id) == 'D' || (id) == 'd' || (id) == 'V' || \ (id) == 'E' || (id) == 'N' || (id) == 'A') static void handleSyncLoss(PGconn *conn, char id, int msgLength); static int getRowDescriptions(PGconn *conn, int msgLength); static int getParamDescriptions(PGconn *conn, int msgLength); static int getAnotherTuple(PGconn *conn, int msgLength); static int getParameterStatus(PGconn *conn); static int getNotify(PGconn *conn); static int getCopyStart(PGconn *conn, ExecStatusType copytype); static int getReadyForQuery(PGconn *conn); static void reportErrorPosition(PQExpBuffer msg, const char *query, int loc, int encoding); static int build_startup_packet(const PGconn *conn, char *packet, const PQEnvironmentOption *options); /* * parseInput: if appropriate, parse input data from backend * until input is exhausted or a stopping state is reached. * Note that this function will NOT attempt to read more data from the backend. */ void pqParseInput3(PGconn *conn) { char id; int msgLength; int avail; /* * Loop to parse successive complete messages available in the buffer. */ for (;;) { /* * Try to read a message. First get the type code and length. Return * if not enough data. */ conn->inCursor = conn->inStart; if (pqGetc(&id, conn)) return; if (pqGetInt(&msgLength, 4, conn)) return; /* * Try to validate message type/length here. A length less than 4 is * definitely broken. Large lengths should only be believed for a few * message types. */ if (msgLength < 4) { handleSyncLoss(conn, id, msgLength); return; } if (msgLength > 30000 && !VALID_LONG_MESSAGE_TYPE(id)) { handleSyncLoss(conn, id, msgLength); return; } /* * Can't process if message body isn't all here yet. */ msgLength -= 4; avail = conn->inEnd - conn->inCursor; if (avail < msgLength) { /* * Before returning, enlarge the input buffer if needed to hold * the whole message. This is better than leaving it to * pqReadData because we can avoid multiple cycles of realloc() * when the message is large; also, we can implement a reasonable * recovery strategy if we are unable to make the buffer big * enough. */ if (pqCheckInBufferSpace(conn->inCursor + (size_t) msgLength, conn)) { /* * XXX add some better recovery code... plan is to skip over * the message using its length, then report an error. For the * moment, just treat this like loss of sync (which indeed it * might be!) */ handleSyncLoss(conn, id, msgLength); } return; } /* * NOTIFY and NOTICE messages can happen in any state; always process * them right away. * * Most other messages should only be processed while in BUSY state. * (In particular, in READY state we hold off further parsing until * the application collects the current PGresult.) * * However, if the state is IDLE then we got trouble; we need to deal * with the unexpected message somehow. * * ParameterStatus ('S') messages are a special case: in IDLE state we * must process 'em (this case could happen if a new value was adopted * from config file due to SIGHUP), but otherwise we hold off until * BUSY state. */ if (id == 'A') { if (getNotify(conn)) return; } else if (id == 'N') { if (pqGetErrorNotice3(conn, false)) return; } else if (conn->asyncStatus != PGASYNC_BUSY) { /* If not IDLE state, just wait ... */ if (conn->asyncStatus != PGASYNC_IDLE) return; /* * Unexpected message in IDLE state; need to recover somehow. * ERROR messages are handled using the notice processor; * ParameterStatus is handled normally; anything else is just * dropped on the floor after displaying a suitable warning * notice. (An ERROR is very possibly the backend telling us why * it is about to close the connection, so we don't want to just * discard it...) */ if (id == 'E') { if (pqGetErrorNotice3(conn, false /* treat as notice */ )) return; } else if (id == 'S') { if (getParameterStatus(conn)) return; } else { pqInternalNotice(&conn->noticeHooks, "message type 0x%02x arrived from server while idle", id); /* Discard the unexpected message */ conn->inCursor += msgLength; } } else { /* * In BUSY state, we can process everything. */ switch (id) { case 'C': /* command complete */ if (pqGets(&conn->workBuffer, conn)) return; if (conn->result == NULL) { conn->result = PQmakeEmptyPGresult(conn, PGRES_COMMAND_OK); if (!conn->result) { printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory")); pqSaveErrorResult(conn); } } if (conn->result) strlcpy(conn->result->cmdStatus, conn->workBuffer.data, CMDSTATUS_LEN); conn->asyncStatus = PGASYNC_READY; break; case 'E': /* error return */ if (pqGetErrorNotice3(conn, true)) return; conn->asyncStatus = PGASYNC_READY; break; case 'Z': /* backend is ready for new query */ if (getReadyForQuery(conn)) return; conn->asyncStatus = PGASYNC_IDLE; break; case 'I': /* empty query */ if (conn->result == NULL) { conn->result = PQmakeEmptyPGresult(conn, PGRES_EMPTY_QUERY); if (!conn->result) { printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory")); pqSaveErrorResult(conn); } } conn->asyncStatus = PGASYNC_READY; break; case '1': /* Parse Complete */ /* If we're doing PQprepare, we're done; else ignore */ if (conn->queryclass == PGQUERY_PREPARE) { if (conn->result == NULL) { conn->result = PQmakeEmptyPGresult(conn, PGRES_COMMAND_OK); if (!conn->result) { printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory")); pqSaveErrorResult(conn); } } conn->asyncStatus = PGASYNC_READY; } break; case '2': /* Bind Complete */ case '3': /* Close Complete */ /* Nothing to do for these message types */ break; case 'S': /* parameter status */ if (getParameterStatus(conn)) return; break; case 'K': /* secret key data from the backend */ /* * This is expected only during backend startup, but it's * just as easy to handle it as part of the main loop. * Save the data and continue processing. */ if (pqGetInt(&(conn->be_pid), 4, conn)) return; if (pqGetInt(&(conn->be_key), 4, conn)) return; break; case 'T': /* Row Description */ if (conn->result != NULL && conn->result->resultStatus == PGRES_FATAL_ERROR) { /* * We've already choked for some reason. Just discard * the data till we get to the end of the query. */ conn->inCursor += msgLength; } else if (conn->result == NULL || conn->queryclass == PGQUERY_DESCRIBE) { /* First 'T' in a query sequence */ if (getRowDescriptions(conn, msgLength)) return; /* getRowDescriptions() moves inStart itself */ continue; } else { /* * A new 'T' message is treated as the start of * another PGresult. (It is not clear that this is * really possible with the current backend.) We stop * parsing until the application accepts the current * result. */ conn->asyncStatus = PGASYNC_READY; return; } break; case 'n': /* No Data */ /* * NoData indicates that we will not be seeing a * RowDescription message because the statement or portal * inquired about doesn't return rows. * * If we're doing a Describe, we have to pass something * back to the client, so set up a COMMAND_OK result, * instead of TUPLES_OK. Otherwise we can just ignore * this message. */ if (conn->queryclass == PGQUERY_DESCRIBE) { if (conn->result == NULL) { conn->result = PQmakeEmptyPGresult(conn, PGRES_COMMAND_OK); if (!conn->result) { printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory")); pqSaveErrorResult(conn); } } conn->asyncStatus = PGASYNC_READY; } break; case 't': /* Parameter Description */ if (getParamDescriptions(conn, msgLength)) return; /* getParamDescriptions() moves inStart itself */ continue; case 'D': /* Data Row */ if (conn->result != NULL && conn->result->resultStatus == PGRES_TUPLES_OK) { /* Read another tuple of a normal query response */ if (getAnotherTuple(conn, msgLength)) return; /* getAnotherTuple() moves inStart itself */ continue; } else if (conn->result != NULL && conn->result->resultStatus == PGRES_FATAL_ERROR) { /* * We've already choked for some reason. Just discard * tuples till we get to the end of the query. */ conn->inCursor += msgLength; } else { /* Set up to report error at end of query */ printfPQExpBuffer(&conn->errorMessage, libpq_gettext("server sent data (\"D\" message) without prior row description (\"T\" message)\n")); pqSaveErrorResult(conn); /* Discard the unexpected message */ conn->inCursor += msgLength; } break; case 'G': /* Start Copy In */ if (getCopyStart(conn, PGRES_COPY_IN)) return; conn->asyncStatus = PGASYNC_COPY_IN; break; case 'H': /* Start Copy Out */ if (getCopyStart(conn, PGRES_COPY_OUT)) return; conn->asyncStatus = PGASYNC_COPY_OUT; conn->copy_already_done = 0; break; case 'W': /* Start Copy Both */ if (getCopyStart(conn, PGRES_COPY_BOTH)) return; conn->asyncStatus = PGASYNC_COPY_BOTH; conn->copy_already_done = 0; break; case 'd': /* Copy Data */ /* * If we see Copy Data, just silently drop it. This would * only occur if application exits COPY OUT mode too * early. */ conn->inCursor += msgLength; break; case 'c': /* Copy Done */ /* * If we see Copy Done, just silently drop it. This is * the normal case during PQendcopy. We will keep * swallowing data, expecting to see command-complete for * the COPY command. */ break; default: printfPQExpBuffer(&conn->errorMessage, libpq_gettext( "unexpected response from server; first received character was \"%c\"\n"), id); /* build an error result holding the error message */ pqSaveErrorResult(conn); /* not sure if we will see more, so go to ready state */ conn->asyncStatus = PGASYNC_READY; /* Discard the unexpected message */ conn->inCursor += msgLength; break; } /* switch on protocol character */ } /* Successfully consumed this message */ if (conn->inCursor == conn->inStart + 5 + msgLength) { /* Normal case: parsing agrees with specified length */ conn->inStart = conn->inCursor; } else { /* Trouble --- report it */ printfPQExpBuffer(&conn->errorMessage, libpq_gettext("message contents do not agree with length in message type \"%c\"\n"), id); /* build an error result holding the error message */ pqSaveErrorResult(conn); conn->asyncStatus = PGASYNC_READY; /* trust the specified message length as what to skip */ conn->inStart += 5 + msgLength; } } } /* * handleSyncLoss: clean up after loss of message-boundary sync * * There isn't really a lot we can do here except abandon the connection. */ static void handleSyncLoss(PGconn *conn, char id, int msgLength) { printfPQExpBuffer(&conn->errorMessage, libpq_gettext( "lost synchronization with server: got message type \"%c\", length %d\n"), id, msgLength); /* build an error result holding the error message */ pqSaveErrorResult(conn); conn->asyncStatus = PGASYNC_READY; /* drop out of GetResult wait loop */ /* flush input data since we're giving up on processing it */ pqDropConnection(conn, true); conn->status = CONNECTION_BAD; /* No more connection to backend */ } /* * parseInput subroutine to read a 'T' (row descriptions) message. * We'll build a new PGresult structure (unless called for a Describe * command for a prepared statement) containing the attribute data. * Returns: 0 if processed message successfully, EOF to suspend parsing * (the latter case is not actually used currently). * In the former case, conn->inStart has been advanced past the message. */ static int getRowDescriptions(PGconn *conn, int msgLength) { PGresult *result; int nfields; const char *errmsg; int i; /* * When doing Describe for a prepared statement, there'll already be a * PGresult created by getParamDescriptions, and we should fill data into * that. Otherwise, create a new, empty PGresult. */ if (conn->queryclass == PGQUERY_DESCRIBE) { if (conn->result) result = conn->result; else result = PQmakeEmptyPGresult(conn, PGRES_COMMAND_OK); } else result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK); if (!result) { errmsg = NULL; /* means "out of memory", see below */ goto advance_and_error; } /* parseInput already read the 'T' label and message length. */ /* the next two bytes are the number of fields */ if (pqGetInt(&(result->numAttributes), 2, conn)) { /* We should not run out of data here, so complain */ errmsg = libpq_gettext("insufficient data in \"T\" message"); goto advance_and_error; } nfields = result->numAttributes; /* allocate space for the attribute descriptors */ if (nfields > 0) { result->attDescs = (PGresAttDesc *) pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE); if (!result->attDescs) { errmsg = NULL; /* means "out of memory", see below */ goto advance_and_error; } MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc)); } /* result->binary is true only if ALL columns are binary */ result->binary = (nfields > 0) ? 1 : 0; /* get type info */ for (i = 0; i < nfields; i++) { int tableid; int columnid; int typid; int typlen; int atttypmod; int format; if (pqGets(&conn->workBuffer, conn) || pqGetInt(&tableid, 4, conn) || pqGetInt(&columnid, 2, conn) || pqGetInt(&typid, 4, conn) || pqGetInt(&typlen, 2, conn) || pqGetInt(&atttypmod, 4, conn) || pqGetInt(&format, 2, conn)) { /* We should not run out of data here, so complain */ errmsg = libpq_gettext("insufficient data in \"T\" message"); goto advance_and_error; } /* * Since pqGetInt treats 2-byte integers as unsigned, we need to * coerce these results to signed form. */ columnid = (int) ((int16) columnid); typlen = (int) ((int16) typlen); format = (int) ((int16) format); result->attDescs[i].name = pqResultStrdup(result, conn->workBuffer.data); if (!result->attDescs[i].name) { errmsg = NULL; /* means "out of memory", see below */ goto advance_and_error; } result->attDescs[i].tableid = tableid; result->attDescs[i].columnid = columnid; result->attDescs[i].format = format; result->attDescs[i].typid = typid; result->attDescs[i].typlen = typlen; result->attDescs[i].atttypmod = atttypmod; if (format != 1) result->binary = 0; } /* Sanity check that we absorbed all the data */ if (conn->inCursor != conn->inStart + 5 + msgLength) { errmsg = libpq_gettext("extraneous data in \"T\" message"); goto advance_and_error; } /* Success! */ conn->result = result; /* Advance inStart to show that the "T" message has been processed. */ conn->inStart = conn->inCursor; /* * If we're doing a Describe, we're done, and ready to pass the result * back to the client. */ if (conn->queryclass == PGQUERY_DESCRIBE) { conn->asyncStatus = PGASYNC_READY; return 0; } /* * We could perform additional setup for the new result set here, but for * now there's nothing else to do. */ /* And we're done. */ return 0; advance_and_error: /* Discard unsaved result, if any */ if (result && result != conn->result) PQclear(result); /* Discard the failed message by pretending we read it */ conn->inStart += 5 + msgLength; /* * Replace partially constructed result with an error result. First * discard the old result to try to win back some memory. */ pqClearAsyncResult(conn); /* * If preceding code didn't provide an error message, assume "out of * memory" was meant. The advantage of having this special case is that * freeing the old result first greatly improves the odds that gettext() * will succeed in providing a translation. */ if (!errmsg) errmsg = libpq_gettext("out of memory for query result"); printfPQExpBuffer(&conn->errorMessage, "%s\n", errmsg); pqSaveErrorResult(conn); /* * Return zero to allow input parsing to continue. Subsequent "D" * messages will be ignored until we get to end of data, since an error * result is already set up. */ return 0; } /* * parseInput subroutine to read a 't' (ParameterDescription) message. * We'll build a new PGresult structure containing the parameter data. * Returns: 0 if completed message, EOF if not enough data yet. * In the former case, conn->inStart has been advanced past the message. * * Note that if we run out of data, we have to release the partially * constructed PGresult, and rebuild it again next time. Fortunately, * that shouldn't happen often, since 't' messages usually fit in a packet. */ static int getParamDescriptions(PGconn *conn, int msgLength) { PGresult *result; const char *errmsg = NULL; /* means "out of memory", see below */ int nparams; int i; result = PQmakeEmptyPGresult(conn, PGRES_COMMAND_OK); if (!result) goto advance_and_error; /* parseInput already read the 't' label and message length. */ /* the next two bytes are the number of parameters */ if (pqGetInt(&(result->numParameters), 2, conn)) goto not_enough_data; nparams = result->numParameters; /* allocate space for the parameter descriptors */ if (nparams > 0) { result->paramDescs = (PGresParamDesc *) pqResultAlloc(result, nparams * sizeof(PGresParamDesc), TRUE); if (!result->paramDescs) goto advance_and_error; MemSet(result->paramDescs, 0, nparams * sizeof(PGresParamDesc)); } /* get parameter info */ for (i = 0; i < nparams; i++) { int typid; if (pqGetInt(&typid, 4, conn)) goto not_enough_data; result->paramDescs[i].typid = typid; } /* Sanity check that we absorbed all the data */ if (conn->inCursor != conn->inStart + 5 + msgLength) { errmsg = libpq_gettext("extraneous data in \"t\" message"); goto advance_and_error; } /* Success! */ conn->result = result; /* Advance inStart to show that the "t" message has been processed. */ conn->inStart = conn->inCursor; return 0; not_enough_data: PQclear(result); return EOF; advance_and_error: /* Discard unsaved result, if any */ if (result && result != conn->result) PQclear(result); /* Discard the failed message by pretending we read it */ conn->inStart += 5 + msgLength; /* * Replace partially constructed result with an error result. First * discard the old result to try to win back some memory. */ pqClearAsyncResult(conn); /* * If preceding code didn't provide an error message, assume "out of * memory" was meant. The advantage of having this special case is that * freeing the old result first greatly improves the odds that gettext() * will succeed in providing a translation. */ if (!errmsg) errmsg = libpq_gettext("out of memory"); printfPQExpBuffer(&conn->errorMessage, "%s\n", errmsg); pqSaveErrorResult(conn); /* * Return zero to allow input parsing to continue. Essentially, we've * replaced the COMMAND_OK result with an error result, but since this * doesn't affect the protocol state, it's fine. */ return 0; } /* * parseInput subroutine to read a 'D' (row data) message. * We fill rowbuf with column pointers and then call the row processor. * Returns: 0 if processed message successfully, EOF to suspend parsing * (the latter case is not actually used currently). * In the former case, conn->inStart has been advanced past the message. */ static int getAnotherTuple(PGconn *conn, int msgLength) { PGresult *result = conn->result; int nfields = result->numAttributes; const char *errmsg; PGdataValue *rowbuf; int tupnfields; /* # fields from tuple */ int vlen; /* length of the current field value */ int i; /* Get the field count and make sure it's what we expect */ if (pqGetInt(&tupnfields, 2, conn)) { /* We should not run out of data here, so complain */ errmsg = libpq_gettext("insufficient data in \"D\" message"); goto advance_and_error; } if (tupnfields != nfields) { errmsg = libpq_gettext("unexpected field count in \"D\" message"); goto advance_and_error; } /* Resize row buffer if needed */ rowbuf = conn->rowBuf; if (nfields > conn->rowBufLen) { rowbuf = (PGdataValue *) realloc(rowbuf, nfields * sizeof(PGdataValue)); if (!rowbuf) { errmsg = NULL; /* means "out of memory", see below */ goto advance_and_error; } conn->rowBuf = rowbuf; conn->rowBufLen = nfields; } /* Scan the fields */ for (i = 0; i < nfields; i++) { /* get the value length */ if (pqGetInt(&vlen, 4, conn)) { /* We should not run out of data here, so complain */ errmsg = libpq_gettext("insufficient data in \"D\" message"); goto advance_and_error; } rowbuf[i].len = vlen; /* * rowbuf[i].value always points to the next address in the data * buffer even if the value is NULL. This allows row processors to * estimate data sizes more easily. */ rowbuf[i].value = conn->inBuffer + conn->inCursor; /* Skip over the data value */ if (vlen > 0) { if (pqSkipnchar(vlen, conn)) { /* We should not run out of data here, so complain */ errmsg = libpq_gettext("insufficient data in \"D\" message"); goto advance_and_error; } } } /* Sanity check that we absorbed all the data */ if (conn->inCursor != conn->inStart + 5 + msgLength) { errmsg = libpq_gettext("extraneous data in \"D\" message"); goto advance_and_error; } /* Advance inStart to show that the "D" message has been processed. */ conn->inStart = conn->inCursor; /* Process the collected row */ errmsg = NULL; if (pqRowProcessor(conn, &errmsg)) return 0; /* normal, successful exit */ goto set_error_result; /* pqRowProcessor failed, report it */ advance_and_error: /* Discard the failed message by pretending we read it */ conn->inStart += 5 + msgLength; set_error_result: /* * Replace partially constructed result with an error result. First * discard the old result to try to win back some memory. */ pqClearAsyncResult(conn); /* * If preceding code didn't provide an error message, assume "out of * memory" was meant. The advantage of having this special case is that * freeing the old result first greatly improves the odds that gettext() * will succeed in providing a translation. */ if (!errmsg) errmsg = libpq_gettext("out of memory for query result"); printfPQExpBuffer(&conn->errorMessage, "%s\n", errmsg); pqSaveErrorResult(conn); /* * Return zero to allow input parsing to continue. Subsequent "D" * messages will be ignored until we get to end of data, since an error * result is already set up. */ return 0; } /* * Attempt to read an Error or Notice response message. * This is possible in several places, so we break it out as a subroutine. * Entry: 'E' or 'N' message type and length have already been consumed. * Exit: returns 0 if successfully consumed message. * returns EOF if not enough data. */ int pqGetErrorNotice3(PGconn *conn, bool isError) { PGresult *res = NULL; bool have_position = false; PQExpBufferData workBuf; char id; /* * Since the fields might be pretty long, we create a temporary * PQExpBuffer rather than using conn->workBuffer. workBuffer is intended * for stuff that is expected to be short. We shouldn't use * conn->errorMessage either, since this might be only a notice. */ initPQExpBuffer(&workBuf); /* * Make a PGresult to hold the accumulated fields. We temporarily lie * about the result status, so that PQmakeEmptyPGresult doesn't uselessly * copy conn->errorMessage. * * NB: This allocation can fail, if you run out of memory. The rest of the * function handles that gracefully, and we still try to set the error * message as the connection's error message. */ res = PQmakeEmptyPGresult(conn, PGRES_EMPTY_QUERY); if (res) res->resultStatus = isError ? PGRES_FATAL_ERROR : PGRES_NONFATAL_ERROR; /* * Read the fields and save into res. * * While at it, save the SQLSTATE in conn->last_sqlstate, and note whether * we saw a PG_DIAG_STATEMENT_POSITION field. */ for (;;) { if (pqGetc(&id, conn)) goto fail; if (id == '\0') break; /* terminator found */ if (pqGets(&workBuf, conn)) goto fail; pqSaveMessageField(res, id, workBuf.data); if (id == PG_DIAG_SQLSTATE) strlcpy(conn->last_sqlstate, workBuf.data, sizeof(conn->last_sqlstate)); else if (id == PG_DIAG_STATEMENT_POSITION) have_position = true; } /* * Save the active query text, if any, into res as well; but only if we * might need it for an error cursor display, which is only true if there * is a PG_DIAG_STATEMENT_POSITION field. */ if (have_position && conn->last_query && res) res->errQuery = pqResultStrdup(res, conn->last_query); /* * Now build the "overall" error message for PQresultErrorMessage. */ resetPQExpBuffer(&workBuf); pqBuildErrorMessage3(&workBuf, res, conn->verbosity, conn->show_context); /* * Either save error as current async result, or just emit the notice. */ if (isError) { if (res) res->errMsg = pqResultStrdup(res, workBuf.data); pqClearAsyncResult(conn); conn->result = res; if (PQExpBufferDataBroken(workBuf)) printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory")); else appendPQExpBufferStr(&conn->errorMessage, workBuf.data); } else { /* if we couldn't allocate the result set, just discard the NOTICE */ if (res) { /* We can cheat a little here and not copy the message. */ res->errMsg = workBuf.data; if (res->noticeHooks.noticeRec != NULL) (*res->noticeHooks.noticeRec) (res->noticeHooks.noticeRecArg, res); PQclear(res); } } termPQExpBuffer(&workBuf); return 0; fail: PQclear(res); termPQExpBuffer(&workBuf); return EOF; } /* * Construct an error message from the fields in the given PGresult, * appending it to the contents of "msg". */ void pqBuildErrorMessage3(PQExpBuffer msg, const PGresult *res, PGVerbosity verbosity, PGContextVisibility show_context) { const char *val; const char *querytext = NULL; int querypos = 0; /* If we couldn't allocate a PGresult, just say "out of memory" */ if (res == NULL) { appendPQExpBuffer(msg, libpq_gettext("out of memory\n")); return; } /* * If we don't have any broken-down fields, just return the base message. * This mainly applies if we're given a libpq-generated error result. */ if (res->errFields == NULL) { if (res->errMsg && res->errMsg[0]) appendPQExpBufferStr(msg, res->errMsg); else appendPQExpBuffer(msg, libpq_gettext("no error message available\n")); return; } /* Else build error message from relevant fields */ val = PQresultErrorField(res, PG_DIAG_SEVERITY); if (val) appendPQExpBuffer(msg, "%s: ", val); if (verbosity == PQERRORS_VERBOSE) { val = PQresultErrorField(res, PG_DIAG_SQLSTATE); if (val) appendPQExpBuffer(msg, "%s: ", val); } val = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY); if (val) appendPQExpBufferStr(msg, val); val = PQresultErrorField(res, PG_DIAG_STATEMENT_POSITION); if (val) { if (verbosity != PQERRORS_TERSE && res->errQuery != NULL) { /* emit position as a syntax cursor display */ querytext = res->errQuery; querypos = atoi(val); } else { /* emit position as text addition to primary message */ /* translator: %s represents a digit string */ appendPQExpBuffer(msg, libpq_gettext(" at character %s"), val); } } else { val = PQresultErrorField(res, PG_DIAG_INTERNAL_POSITION); if (val) { querytext = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY); if (verbosity != PQERRORS_TERSE && querytext != NULL) { /* emit position as a syntax cursor display */ querypos = atoi(val); } else { /* emit position as text addition to primary message */ /* translator: %s represents a digit string */ appendPQExpBuffer(msg, libpq_gettext(" at character %s"), val); } } } appendPQExpBufferChar(msg, '\n'); if (verbosity != PQERRORS_TERSE) { if (querytext && querypos > 0) reportErrorPosition(msg, querytext, querypos, res->client_encoding); val = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL); if (val) appendPQExpBuffer(msg, libpq_gettext("DETAIL: %s\n"), val); val = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT); if (val) appendPQExpBuffer(msg, libpq_gettext("HINT: %s\n"), val); val = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY); if (val) appendPQExpBuffer(msg, libpq_gettext("QUERY: %s\n"), val); if (show_context == PQSHOW_CONTEXT_ALWAYS || (show_context == PQSHOW_CONTEXT_ERRORS && res->resultStatus == PGRES_FATAL_ERROR)) { val = PQresultErrorField(res, PG_DIAG_CONTEXT); if (val) appendPQExpBuffer(msg, libpq_gettext("CONTEXT: %s\n"), val); } } if (verbosity == PQERRORS_VERBOSE) { val = PQresultErrorField(res, PG_DIAG_SCHEMA_NAME); if (val) appendPQExpBuffer(msg, libpq_gettext("SCHEMA NAME: %s\n"), val); val = PQresultErrorField(res, PG_DIAG_TABLE_NAME); if (val) appendPQExpBuffer(msg, libpq_gettext("TABLE NAME: %s\n"), val); val = PQresultErrorField(res, PG_DIAG_COLUMN_NAME); if (val) appendPQExpBuffer(msg, libpq_gettext("COLUMN NAME: %s\n"), val); val = PQresultErrorField(res, PG_DIAG_DATATYPE_NAME); if (val) appendPQExpBuffer(msg, libpq_gettext("DATATYPE NAME: %s\n"), val); val = PQresultErrorField(res, PG_DIAG_CONSTRAINT_NAME); if (val) appendPQExpBuffer(msg, libpq_gettext("CONSTRAINT NAME: %s\n"), val); } if (verbosity == PQERRORS_VERBOSE) { const char *valf; const char *vall; valf = PQresultErrorField(res, PG_DIAG_SOURCE_FILE); vall = PQresultErrorField(res, PG_DIAG_SOURCE_LINE); val = PQresultErrorField(res, PG_DIAG_SOURCE_FUNCTION); if (val || valf || vall) { appendPQExpBufferStr(msg, libpq_gettext("LOCATION: ")); if (val) appendPQExpBuffer(msg, libpq_gettext("%s, "), val); if (valf && vall) /* unlikely we'd have just one */ appendPQExpBuffer(msg, libpq_gettext("%s:%s"), valf, vall); appendPQExpBufferChar(msg, '\n'); } } } /* * Add an error-location display to the error message under construction. * * The cursor location is measured in logical characters; the query string * is presumed to be in the specified encoding. */ static void reportErrorPosition(PQExpBuffer msg, const char *query, int loc, int encoding) { #define DISPLAY_SIZE 60 /* screen width limit, in screen cols */ #define MIN_RIGHT_CUT 10 /* try to keep this far away from EOL */ char *wquery; int slen, cno, i, *qidx, *scridx, qoffset, scroffset, ibeg, iend, loc_line; bool mb_encoding, beg_trunc, end_trunc; /* Convert loc from 1-based to 0-based; no-op if out of range */ loc--; if (loc < 0) return; /* Need a writable copy of the query */ wquery = strdup(query); if (wquery == NULL) return; /* fail silently if out of memory */ /* * Each character might occupy multiple physical bytes in the string, and * in some Far Eastern character sets it might take more than one screen * column as well. We compute the starting byte offset and starting * screen column of each logical character, and store these in qidx[] and * scridx[] respectively. */ /* we need a safe allocation size... */ slen = strlen(wquery) + 1; qidx = (int *) malloc(slen * sizeof(int)); if (qidx == NULL) { free(wquery); return; } scridx = (int *) malloc(slen * sizeof(int)); if (scridx == NULL) { free(qidx); free(wquery); return; } /* We can optimize a bit if it's a single-byte encoding */ mb_encoding = (pg_encoding_max_length(encoding) != 1); /* * Within the scanning loop, cno is the current character's logical * number, qoffset is its offset in wquery, and scroffset is its starting * logical screen column (all indexed from 0). "loc" is the logical * character number of the error location. We scan to determine loc_line * (the 1-based line number containing loc) and ibeg/iend (first character * number and last+1 character number of the line containing loc). Note * that qidx[] and scridx[] are filled only as far as iend. */ qoffset = 0; scroffset = 0; loc_line = 1; ibeg = 0; iend = -1; /* -1 means not set yet */ for (cno = 0; wquery[qoffset] != '\0'; cno++) { char ch = wquery[qoffset]; qidx[cno] = qoffset; scridx[cno] = scroffset; /* * Replace tabs with spaces in the writable copy. (Later we might * want to think about coping with their variable screen width, but * not today.) */ if (ch == '\t') wquery[qoffset] = ' '; /* * If end-of-line, count lines and mark positions. Each \r or \n * counts as a line except when \r \n appear together. */ else if (ch == '\r' || ch == '\n') { if (cno < loc) { if (ch == '\r' || cno == 0 || wquery[qidx[cno - 1]] != '\r') loc_line++; /* extract beginning = last line start before loc. */ ibeg = cno + 1; } else { /* set extract end. */ iend = cno; /* done scanning. */ break; } } /* Advance */ if (mb_encoding) { int w; w = pg_encoding_dsplen(encoding, &wquery[qoffset]); /* treat any non-tab control chars as width 1 */ if (w <= 0) w = 1; scroffset += w; qoffset += pg_encoding_mblen(encoding, &wquery[qoffset]); } else { /* We assume wide chars only exist in multibyte encodings */ scroffset++; qoffset++; } } /* Fix up if we didn't find an end-of-line after loc */ if (iend < 0) { iend = cno; /* query length in chars, +1 */ qidx[iend] = qoffset; scridx[iend] = scroffset; } /* Print only if loc is within computed query length */ if (loc <= cno) { /* If the line extracted is too long, we truncate it. */ beg_trunc = false; end_trunc = false; if (scridx[iend] - scridx[ibeg] > DISPLAY_SIZE) { /* * We first truncate right if it is enough. This code might be * off a space or so on enforcing MIN_RIGHT_CUT if there's a wide * character right there, but that should be okay. */ if (scridx[ibeg] + DISPLAY_SIZE >= scridx[loc] + MIN_RIGHT_CUT) { while (scridx[iend] - scridx[ibeg] > DISPLAY_SIZE) iend--; end_trunc = true; } else { /* Truncate right if not too close to loc. */ while (scridx[loc] + MIN_RIGHT_CUT < scridx[iend]) { iend--; end_trunc = true; } /* Truncate left if still too long. */ while (scridx[iend] - scridx[ibeg] > DISPLAY_SIZE) { ibeg++; beg_trunc = true; } } } /* truncate working copy at desired endpoint */ wquery[qidx[iend]] = '\0'; /* Begin building the finished message. */ i = msg->len; appendPQExpBuffer(msg, libpq_gettext("LINE %d: "), loc_line); if (beg_trunc) appendPQExpBufferStr(msg, "..."); /* * While we have the prefix in the msg buffer, compute its screen * width. */ scroffset = 0; for (; i < msg->len; i += pg_encoding_mblen(encoding, &msg->data[i])) { int w = pg_encoding_dsplen(encoding, &msg->data[i]); if (w <= 0) w = 1; scroffset += w; } /* Finish up the LINE message line. */ appendPQExpBufferStr(msg, &wquery[qidx[ibeg]]); if (end_trunc) appendPQExpBufferStr(msg, "..."); appendPQExpBufferChar(msg, '\n'); /* Now emit the cursor marker line. */ scroffset += scridx[loc] - scridx[ibeg]; for (i = 0; i < scroffset; i++) appendPQExpBufferChar(msg, ' '); appendPQExpBufferChar(msg, '^'); appendPQExpBufferChar(msg, '\n'); } /* Clean up. */ free(scridx); free(qidx); free(wquery); } /* * Attempt to read a ParameterStatus message. * This is possible in several places, so we break it out as a subroutine. * Entry: 'S' message type and length have already been consumed. * Exit: returns 0 if successfully consumed message. * returns EOF if not enough data. */ static int getParameterStatus(PGconn *conn) { PQExpBufferData valueBuf; /* Get the parameter name */ if (pqGets(&conn->workBuffer, conn)) return EOF; /* Get the parameter value (could be large) */ initPQExpBuffer(&valueBuf); if (pqGets(&valueBuf, conn)) { termPQExpBuffer(&valueBuf); return EOF; } /* And save it */ pqSaveParameterStatus(conn, conn->workBuffer.data, valueBuf.data); termPQExpBuffer(&valueBuf); return 0; } /* * Attempt to read a Notify response message. * This is possible in several places, so we break it out as a subroutine. * Entry: 'A' message type and length have already been consumed. * Exit: returns 0 if successfully consumed Notify message. * returns EOF if not enough data. */ static int getNotify(PGconn *conn) { int be_pid; char *svname; int nmlen; int extralen; PGnotify *newNotify; if (pqGetInt(&be_pid, 4, conn)) return EOF; if (pqGets(&conn->workBuffer, conn)) return EOF; /* must save name while getting extra string */ svname = strdup(conn->workBuffer.data); if (!svname) return EOF; if (pqGets(&conn->workBuffer, conn)) { free(svname); return EOF; } /* * Store the strings right after the PQnotify structure so it can all be * freed at once. We don't use NAMEDATALEN because we don't want to tie * this interface to a specific server name length. */ nmlen = strlen(svname); extralen = strlen(conn->workBuffer.data); newNotify = (PGnotify *) malloc(sizeof(PGnotify) + nmlen + extralen + 2); if (newNotify) { newNotify->relname = (char *) newNotify + sizeof(PGnotify); strcpy(newNotify->relname, svname); newNotify->extra = newNotify->relname + nmlen + 1; strcpy(newNotify->extra, conn->workBuffer.data); newNotify->be_pid = be_pid; newNotify->next = NULL; if (conn->notifyTail) conn->notifyTail->next = newNotify; else conn->notifyHead = newNotify; conn->notifyTail = newNotify; } free(svname); return 0; } /* * getCopyStart - process CopyInResponse, CopyOutResponse or * CopyBothResponse message * * parseInput already read the message type and length. */ static int getCopyStart(PGconn *conn, ExecStatusType copytype) { PGresult *result; int nfields; int i; result = PQmakeEmptyPGresult(conn, copytype); if (!result) goto failure; if (pqGetc(&conn->copy_is_binary, conn)) goto failure; result->binary = conn->copy_is_binary; /* the next two bytes are the number of fields */ if (pqGetInt(&(result->numAttributes), 2, conn)) goto failure; nfields = result->numAttributes; /* allocate space for the attribute descriptors */ if (nfields > 0) { result->attDescs = (PGresAttDesc *) pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE); if (!result->attDescs) goto failure; MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc)); } for (i = 0; i < nfields; i++) { int format; if (pqGetInt(&format, 2, conn)) goto failure; /* * Since pqGetInt treats 2-byte integers as unsigned, we need to * coerce these results to signed form. */ format = (int) ((int16) format); result->attDescs[i].format = format; } /* Success! */ conn->result = result; return 0; failure: PQclear(result); return EOF; } /* * getReadyForQuery - process ReadyForQuery message */ static int getReadyForQuery(PGconn *conn) { char xact_status; if (pqGetc(&xact_status, conn)) return EOF; switch (xact_status) { case 'I': conn->xactStatus = PQTRANS_IDLE; break; case 'T': conn->xactStatus = PQTRANS_INTRANS; break; case 'E': conn->xactStatus = PQTRANS_INERROR; break; default: conn->xactStatus = PQTRANS_UNKNOWN; break; } return 0; } /* * getCopyDataMessage - fetch next CopyData message, process async messages * * Returns length word of CopyData message (> 0), or 0 if no complete * message available, -1 if end of copy, -2 if error. */ static int getCopyDataMessage(PGconn *conn) { char id; int msgLength; int avail; for (;;) { /* * Do we have the next input message? To make life simpler for async * callers, we keep returning 0 until the next message is fully * available, even if it is not Copy Data. */ conn->inCursor = conn->inStart; if (pqGetc(&id, conn)) return 0; if (pqGetInt(&msgLength, 4, conn)) return 0; if (msgLength < 4) { handleSyncLoss(conn, id, msgLength); return -2; } avail = conn->inEnd - conn->inCursor; if (avail < msgLength - 4) { /* * Before returning, enlarge the input buffer if needed to hold * the whole message. See notes in parseInput. */ if (pqCheckInBufferSpace(conn->inCursor + (size_t) msgLength - 4, conn)) { /* * XXX add some better recovery code... plan is to skip over * the message using its length, then report an error. For the * moment, just treat this like loss of sync (which indeed it * might be!) */ handleSyncLoss(conn, id, msgLength); return -2; } return 0; } /* * If it's a legitimate async message type, process it. (NOTIFY * messages are not currently possible here, but we handle them for * completeness.) Otherwise, if it's anything except Copy Data, * report end-of-copy. */ switch (id) { case 'A': /* NOTIFY */ if (getNotify(conn)) return 0; break; case 'N': /* NOTICE */ if (pqGetErrorNotice3(conn, false)) return 0; break; case 'S': /* ParameterStatus */ if (getParameterStatus(conn)) return 0; break; case 'd': /* Copy Data, pass it back to caller */ return msgLength; case 'c': /* * If this is a CopyDone message, exit COPY_OUT mode and let * caller read status with PQgetResult(). If we're in * COPY_BOTH mode, return to COPY_IN mode. */ if (conn->asyncStatus == PGASYNC_COPY_BOTH) conn->asyncStatus = PGASYNC_COPY_IN; else conn->asyncStatus = PGASYNC_BUSY; return -1; default: /* treat as end of copy */ /* * Any other message terminates either COPY_IN or COPY_BOTH * mode. */ conn->asyncStatus = PGASYNC_BUSY; return -1; } /* Drop the processed message and loop around for another */ conn->inStart = conn->inCursor; } } /* * PQgetCopyData - read a row of data from the backend during COPY OUT * or COPY BOTH * * If successful, sets *buffer to point to a malloc'd row of data, and * returns row length (always > 0) as result. * Returns 0 if no row available yet (only possible if async is true), * -1 if end of copy (consult PQgetResult), or -2 if error (consult * PQerrorMessage). */ int pqGetCopyData3(PGconn *conn, char **buffer, int async) { int msgLength; for (;;) { /* * Collect the next input message. To make life simpler for async * callers, we keep returning 0 until the next message is fully * available, even if it is not Copy Data. */ msgLength = getCopyDataMessage(conn); if (msgLength < 0) return msgLength; /* end-of-copy or error */ if (msgLength == 0) { /* Don't block if async read requested */ if (async) return 0; /* Need to load more data */ if (pqWait(TRUE, FALSE, conn) || pqReadData(conn) < 0) return -2; continue; } /* * Drop zero-length messages (shouldn't happen anyway). Otherwise * pass the data back to the caller. */ msgLength -= 4; if (msgLength > 0) { *buffer = (char *) malloc(msgLength + 1); if (*buffer == NULL) { printfPQExpBuffer(&conn->errorMessage, libpq_gettext("out of memory\n")); return -2; } memcpy(*buffer, &conn->inBuffer[conn->inCursor], msgLength); (*buffer)[msgLength] = '\0'; /* Add terminating null */ /* Mark message consumed */ conn->inStart = conn->inCursor + msgLength; return msgLength; } /* Empty, so drop it and loop around for another */ conn->inStart = conn->inCursor; } } /* * PQgetline - gets a newline-terminated string from the backend. * * See fe-exec.c for documentation. */ int pqGetline3(PGconn *conn, char *s, int maxlen) { int status; if (conn->sock == PGINVALID_SOCKET || (conn->asyncStatus != PGASYNC_COPY_OUT && conn->asyncStatus != PGASYNC_COPY_BOTH) || conn->copy_is_binary) { printfPQExpBuffer(&conn->errorMessage, libpq_gettext("PQgetline: not doing text COPY OUT\n")); *s = '\0'; return EOF; } while ((status = PQgetlineAsync(conn, s, maxlen - 1)) == 0) { /* need to load more data */ if (pqWait(TRUE, FALSE, conn) || pqReadData(conn) < 0) { *s = '\0'; return EOF; } } if (status < 0) { /* End of copy detected; gin up old-style terminator */ strcpy(s, "\\."); return 0; } /* Add null terminator, and strip trailing \n if present */ if (s[status - 1] == '\n') { s[status - 1] = '\0'; return 0; } else { s[status] = '\0'; return 1; } } /* * PQgetlineAsync - gets a COPY data row without blocking. * * See fe-exec.c for documentation. */ int pqGetlineAsync3(PGconn *conn, char *buffer, int bufsize) { int msgLength; int avail; if (conn->asyncStatus != PGASYNC_COPY_OUT && conn->asyncStatus != PGASYNC_COPY_BOTH) return -1; /* we are not doing a copy... */ /* * Recognize the next input message. To make life simpler for async * callers, we keep returning 0 until the next message is fully available * even if it is not Copy Data. This should keep PQendcopy from blocking. * (Note: unlike pqGetCopyData3, we do not change asyncStatus here.) */ msgLength = getCopyDataMessage(conn); if (msgLength < 0) return -1; /* end-of-copy or error */ if (msgLength == 0) return 0; /* no data yet */ /* * Move data from libpq's buffer to the caller's. In the case where a * prior call found the caller's buffer too small, we use * conn->copy_already_done to remember how much of the row was already * returned to the caller. */ conn->inCursor += conn->copy_already_done; avail = msgLength - 4 - conn->copy_already_done; if (avail <= bufsize) { /* Able to consume the whole message */ memcpy(buffer, &conn->inBuffer[conn->inCursor], avail); /* Mark message consumed */ conn->inStart = conn->inCursor + avail; /* Reset state for next time */ conn->copy_already_done = 0; return avail; } else { /* We must return a partial message */ memcpy(buffer, &conn->inBuffer[conn->inCursor], bufsize); /* The message is NOT consumed from libpq's buffer */ conn->copy_already_done += bufsize; return bufsize; } } /* * PQendcopy * * See fe-exec.c for documentation. */ int pqEndcopy3(PGconn *conn) { PGresult *result; if (conn->asyncStatus != PGASYNC_COPY_IN && conn->asyncStatus != PGASYNC_COPY_OUT && conn->asyncStatus != PGASYNC_COPY_BOTH) { printfPQExpBuffer(&conn->errorMessage, libpq_gettext("no COPY in progress\n")); return 1; } /* Send the CopyDone message if needed */ if (conn->asyncStatus == PGASYNC_COPY_IN || conn->asyncStatus == PGASYNC_COPY_BOTH) { if (pqPutMsgStart('c', false, conn) < 0 || pqPutMsgEnd(conn) < 0) return 1; /* * If we sent the COPY command in extended-query mode, we must issue a * Sync as well. */ if (conn->queryclass != PGQUERY_SIMPLE) { if (pqPutMsgStart('S', false, conn) < 0 || pqPutMsgEnd(conn) < 0) return 1; } } /* * make sure no data is waiting to be sent, abort if we are non-blocking * and the flush fails */ if (pqFlush(conn) && pqIsnonblocking(conn)) return 1; /* Return to active duty */ conn->asyncStatus = PGASYNC_BUSY; resetPQExpBuffer(&conn->errorMessage); /* * Non blocking connections may have to abort at this point. If everyone * played the game there should be no problem, but in error scenarios the * expected messages may not have arrived yet. (We are assuming that the * backend's packetizing will ensure that CommandComplete arrives along * with the CopyDone; are there corner cases where that doesn't happen?) */ if (pqIsnonblocking(conn) && PQisBusy(conn)) return 1; /* Wait for the completion response */ result = PQgetResult(conn); /* Expecting a successful result */ if (result && result->resultStatus == PGRES_COMMAND_OK) { PQclear(result); return 0; } /* * Trouble. For backwards-compatibility reasons, we issue the error * message as if it were a notice (would be nice to get rid of this * silliness, but too many apps probably don't handle errors from * PQendcopy reasonably). Note that the app can still obtain the error * status from the PGconn object. */ if (conn->errorMessage.len > 0) { /* We have to strip the trailing newline ... pain in neck... */ char svLast = conn->errorMessage.data[conn->errorMessage.len - 1]; if (svLast == '\n') conn->errorMessage.data[conn->errorMessage.len - 1] = '\0'; pqInternalNotice(&conn->noticeHooks, "%s", conn->errorMessage.data); conn->errorMessage.data[conn->errorMessage.len - 1] = svLast; } PQclear(result); return 1; } /* * PQfn - Send a function call to the POSTGRES backend. * * See fe-exec.c for documentation. */ PGresult * pqFunctionCall3(PGconn *conn, Oid fnid, int *result_buf, int *actual_result_len, int result_is_int, const PQArgBlock *args, int nargs) { bool needInput = false; ExecStatusType status = PGRES_FATAL_ERROR; char id; int msgLength; int avail; int i; /* PQfn already validated connection state */ if (pqPutMsgStart('F', false, conn) < 0 || /* function call msg */ pqPutInt(fnid, 4, conn) < 0 || /* function id */ pqPutInt(1, 2, conn) < 0 || /* # of format codes */ pqPutInt(1, 2, conn) < 0 || /* format code: BINARY */ pqPutInt(nargs, 2, conn) < 0) /* # of args */ { pqHandleSendFailure(conn); return NULL; } for (i = 0; i < nargs; ++i) { /* len.int4 + contents */ if (pqPutInt(args[i].len, 4, conn)) { pqHandleSendFailure(conn); return NULL; } if (args[i].len == -1) continue; /* it's NULL */ if (args[i].isint) { if (pqPutInt(args[i].u.integer, args[i].len, conn)) { pqHandleSendFailure(conn); return NULL; } } else { if (pqPutnchar((char *) args[i].u.ptr, args[i].len, conn)) { pqHandleSendFailure(conn); return NULL; } } } if (pqPutInt(1, 2, conn) < 0) /* result format code: BINARY */ { pqHandleSendFailure(conn); return NULL; } if (pqPutMsgEnd(conn) < 0 || pqFlush(conn)) { pqHandleSendFailure(conn); return NULL; } for (;;) { if (needInput) { /* Wait for some data to arrive (or for the channel to close) */ if (pqWait(TRUE, FALSE, conn) || pqReadData(conn) < 0) break; } /* * Scan the message. If we run out of data, loop around to try again. */ needInput = true; conn->inCursor = conn->inStart; if (pqGetc(&id, conn)) continue; if (pqGetInt(&msgLength, 4, conn)) continue; /* * Try to validate message type/length here. A length less than 4 is * definitely broken. Large lengths should only be believed for a few * message types. */ if (msgLength < 4) { handleSyncLoss(conn, id, msgLength); break; } if (msgLength > 30000 && !VALID_LONG_MESSAGE_TYPE(id)) { handleSyncLoss(conn, id, msgLength); break; } /* * Can't process if message body isn't all here yet. */ msgLength -= 4; avail = conn->inEnd - conn->inCursor; if (avail < msgLength) { /* * Before looping, enlarge the input buffer if needed to hold the * whole message. See notes in parseInput. */ if (pqCheckInBufferSpace(conn->inCursor + (size_t) msgLength, conn)) { /* * XXX add some better recovery code... plan is to skip over * the message using its length, then report an error. For the * moment, just treat this like loss of sync (which indeed it * might be!) */ handleSyncLoss(conn, id, msgLength); break; } continue; } /* * We should see V or E response to the command, but might get N * and/or A notices first. We also need to swallow the final Z before * returning. */ switch (id) { case 'V': /* function result */ if (pqGetInt(actual_result_len, 4, conn)) continue; if (*actual_result_len != -1) { if (result_is_int) { if (pqGetInt(result_buf, *actual_result_len, conn)) continue; } else { if (pqGetnchar((char *) result_buf, *actual_result_len, conn)) continue; } } /* correctly finished function result message */ status = PGRES_COMMAND_OK; break; case 'E': /* error return */ if (pqGetErrorNotice3(conn, true)) continue; status = PGRES_FATAL_ERROR; break; case 'A': /* notify message */ /* handle notify and go back to processing return values */ if (getNotify(conn)) continue; break; case 'N': /* notice */ /* handle notice and go back to processing return values */ if (pqGetErrorNotice3(conn, false)) continue; break; case 'Z': /* backend is ready for new query */ if (getReadyForQuery(conn)) continue; /* consume the message and exit */ conn->inStart += 5 + msgLength; /* if we saved a result object (probably an error), use it */ if (conn->result) return pqPrepareAsyncResult(conn); return PQmakeEmptyPGresult(conn, status); case 'S': /* parameter status */ if (getParameterStatus(conn)) continue; break; default: /* The backend violates the protocol. */ printfPQExpBuffer(&conn->errorMessage, libpq_gettext("protocol error: id=0x%x\n"), id); pqSaveErrorResult(conn); /* trust the specified message length as what to skip */ conn->inStart += 5 + msgLength; return pqPrepareAsyncResult(conn); } /* Completed this message, keep going */ /* trust the specified message length as what to skip */ conn->inStart += 5 + msgLength; needInput = false; } /* * We fall out of the loop only upon failing to read data. * conn->errorMessage has been set by pqWait or pqReadData. We want to * append it to any already-received error message. */ pqSaveErrorResult(conn); return pqPrepareAsyncResult(conn); } /* * Construct startup packet * * Returns a malloc'd packet buffer, or NULL if out of memory */ char * pqBuildStartupPacket3(PGconn *conn, int *packetlen, const PQEnvironmentOption *options) { char *startpacket; *packetlen = build_startup_packet(conn, NULL, options); startpacket = (char *) malloc(*packetlen); if (!startpacket) return NULL; *packetlen = build_startup_packet(conn, startpacket, options); return startpacket; } /* * Build a startup packet given a filled-in PGconn structure. * * We need to figure out how much space is needed, then fill it in. * To avoid duplicate logic, this routine is called twice: the first time * (with packet == NULL) just counts the space needed, the second time * (with packet == allocated space) fills it in. Return value is the number * of bytes used. */ static int build_startup_packet(const PGconn *conn, char *packet, const PQEnvironmentOption *options) { int packet_len = 0; const PQEnvironmentOption *next_eo; const char *val; /* Protocol version comes first. */ if (packet) { ProtocolVersion pv = htonl(conn->pversion); memcpy(packet + packet_len, &pv, sizeof(ProtocolVersion)); } packet_len += sizeof(ProtocolVersion); /* Add user name, database name, options */ #define ADD_STARTUP_OPTION(optname, optval) \ do { \ if (packet) \ strcpy(packet + packet_len, optname); \ packet_len += strlen(optname) + 1; \ if (packet) \ strcpy(packet + packet_len, optval); \ packet_len += strlen(optval) + 1; \ } while(0) if (conn->pguser && conn->pguser[0]) ADD_STARTUP_OPTION("user", conn->pguser); if (conn->dbName && conn->dbName[0]) ADD_STARTUP_OPTION("database", conn->dbName); if (conn->replication && conn->replication[0]) ADD_STARTUP_OPTION("replication", conn->replication); if (conn->pgoptions && conn->pgoptions[0]) ADD_STARTUP_OPTION("options", conn->pgoptions); if (conn->send_appname) { /* Use appname if present, otherwise use fallback */ val = conn->appname ? conn->appname : conn->fbappname; if (val && val[0]) ADD_STARTUP_OPTION("application_name", val); } if (conn->client_encoding_initial && conn->client_encoding_initial[0]) ADD_STARTUP_OPTION("client_encoding", conn->client_encoding_initial); /* Add any environment-driven GUC settings needed */ for (next_eo = options; next_eo->envName; next_eo++) { if ((val = getenv(next_eo->envName)) != NULL) { if (pg_strcasecmp(val, "default") != 0) ADD_STARTUP_OPTION(next_eo->pgName, val); } } /* Add trailing terminator */ if (packet) packet[packet_len] = '\0'; packet_len++; return packet_len; }