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Improve libpq's handling of OOM during error message construction.
[pgsql.git] / src / interfaces / libpq / fe-protocol3.c
blob9ab3bf1fcb61a7105bb5ca5f233dd2e2f8568662
1 /*-------------------------------------------------------------------------
2 *
3 * fe-protocol3.c
4 * functions that are specific to frontend/backend protocol version 3
5 *
6 * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 *
10 * IDENTIFICATION
11 * src/interfaces/libpq/fe-protocol3.c
12 *
13 *-------------------------------------------------------------------------
14 */
15 #include "postgres_fe.h"
16
17 #include <ctype.h>
18 #include <fcntl.h>
19
20 #ifdef WIN32
21 #include "win32.h"
22 #else
23 #include <unistd.h>
24 #ifdef HAVE_NETINET_TCP_H
25 #include <netinet/tcp.h>
26 #endif
27 #endif
28
29 #include "libpq-fe.h"
30 #include "libpq-int.h"
31 #include "mb/pg_wchar.h"
32 #include "port/pg_bswap.h"
33
34 /*
35 * This macro lists the backend message types that could be "long" (more
36 * than a couple of kilobytes).
37 */
38 #define VALID_LONG_MESSAGE_TYPE(id) \
39 ((id) == 'T' || (id) == 'D' || (id) == 'd' || (id) == 'V' || \
40 (id) == 'E' || (id) == 'N' || (id) == 'A')
41
42
43 static void handleSyncLoss(PGconn *conn, char id, int msgLength);
44 static int getRowDescriptions(PGconn *conn, int msgLength);
45 static int getParamDescriptions(PGconn *conn, int msgLength);
46 static int getAnotherTuple(PGconn *conn, int msgLength);
47 static int getParameterStatus(PGconn *conn);
48 static int getNotify(PGconn *conn);
49 static int getCopyStart(PGconn *conn, ExecStatusType copytype);
50 static int getReadyForQuery(PGconn *conn);
51 static void reportErrorPosition(PQExpBuffer msg, const char *query,
52 int loc, int encoding);
53 static int build_startup_packet(const PGconn *conn, char *packet,
54 const PQEnvironmentOption *options);
55
56
57 /*
58 * parseInput: if appropriate, parse input data from backend
59 * until input is exhausted or a stopping state is reached.
60 * Note that this function will NOT attempt to read more data from the backend.
61 */
62 void
63 pqParseInput3(PGconn *conn)
64 {
65 char id;
66 int msgLength;
67 int avail;
68
69 /*
70 * Loop to parse successive complete messages available in the buffer.
71 */
72 for (;;)
73 {
74 /*
75 * Try to read a message. First get the type code and length. Return
76 * if not enough data.
77 */
78 conn->inCursor = conn->inStart;
79 if (pqGetc(&id, conn))
80 return;
81 if (pqGetInt(&msgLength, 4, conn))
82 return;
83
84 /*
85 * Try to validate message type/length here. A length less than 4 is
86 * definitely broken. Large lengths should only be believed for a few
87 * message types.
88 */
89 if (msgLength < 4)
90 {
91 handleSyncLoss(conn, id, msgLength);
92 return;
93 }
94 if (msgLength > 30000 && !VALID_LONG_MESSAGE_TYPE(id))
95 {
96 handleSyncLoss(conn, id, msgLength);
97 return;
98 }
99
100 /*
101 * Can't process if message body isn't all here yet.
102 */
103 msgLength -= 4;
104 avail = conn->inEnd - conn->inCursor;
105 if (avail < msgLength)
106 {
107 /*
108 * Before returning, enlarge the input buffer if needed to hold
109 * the whole message. This is better than leaving it to
110 * pqReadData because we can avoid multiple cycles of realloc()
111 * when the message is large; also, we can implement a reasonable
112 * recovery strategy if we are unable to make the buffer big
113 * enough.
114 */
115 if (pqCheckInBufferSpace(conn->inCursor + (size_t) msgLength,
116 conn))
117 {
118 /*
119 * XXX add some better recovery code... plan is to skip over
120 * the message using its length, then report an error. For the
121 * moment, just treat this like loss of sync (which indeed it
122 * might be!)
123 */
124 handleSyncLoss(conn, id, msgLength);
125 }
126 return;
127 }
128
129 /*
130 * NOTIFY and NOTICE messages can happen in any state; always process
131 * them right away.
132 *
133 * Most other messages should only be processed while in BUSY state.
134 * (In particular, in READY state we hold off further parsing until
135 * the application collects the current PGresult.)
136 *
137 * However, if the state is IDLE then we got trouble; we need to deal
138 * with the unexpected message somehow.
139 *
140 * ParameterStatus ('S') messages are a special case: in IDLE state we
141 * must process 'em (this case could happen if a new value was adopted
142 * from config file due to SIGHUP), but otherwise we hold off until
143 * BUSY state.
144 */
145 if (id == 'A')
146 {
147 if (getNotify(conn))
148 return;
149 }
150 else if (id == 'N')
151 {
152 if (pqGetErrorNotice3(conn, false))
153 return;
154 }
155 else if (conn->asyncStatus != PGASYNC_BUSY)
156 {
157 /* If not IDLE state, just wait ... */
158 if (conn->asyncStatus != PGASYNC_IDLE)
159 return;
160
161 /*
162 * We're also notionally not-IDLE when in pipeline mode the state
163 * says "idle" (so we have completed receiving the results of one
164 * query from the server and dispatched them to the application)
165 * but another query is queued; yield back control to caller so
166 * that they can initiate processing of the next query in the
167 * queue.
168 */
169 if (conn->pipelineStatus != PQ_PIPELINE_OFF &&
170 conn->cmd_queue_head != NULL)
171 return;
172
173 /*
174 * Unexpected message in IDLE state; need to recover somehow.
175 * ERROR messages are handled using the notice processor;
176 * ParameterStatus is handled normally; anything else is just
177 * dropped on the floor after displaying a suitable warning
178 * notice. (An ERROR is very possibly the backend telling us why
179 * it is about to close the connection, so we don't want to just
180 * discard it...)
181 */
182 if (id == 'E')
183 {
184 if (pqGetErrorNotice3(conn, false /* treat as notice */ ))
185 return;
186 }
187 else if (id == 'S')
188 {
189 if (getParameterStatus(conn))
190 return;
191 }
192 else
193 {
194 /* Any other case is unexpected and we summarily skip it */
195 pqInternalNotice(&conn->noticeHooks,
196 "message type 0x%02x arrived from server while idle",
197 id);
198 /* Discard the unexpected message */
199 conn->inCursor += msgLength;
200 }
201 }
202 else
203 {
204 /*
205 * In BUSY state, we can process everything.
206 */
207 switch (id)
208 {
209 case 'C': /* command complete */
210 if (pqGets(&conn->workBuffer, conn))
211 return;
212 if (conn->result == NULL)
213 {
214 conn->result = PQmakeEmptyPGresult(conn,
215 PGRES_COMMAND_OK);
216 if (!conn->result)
217 {
218 appendPQExpBufferStr(&conn->errorMessage,
219 libpq_gettext("out of memory"));
220 pqSaveErrorResult(conn);
221 }
222 }
223 if (conn->result)
224 strlcpy(conn->result->cmdStatus, conn->workBuffer.data,
225 CMDSTATUS_LEN);
226 conn->asyncStatus = PGASYNC_READY;
227 break;
228 case 'E': /* error return */
229 if (pqGetErrorNotice3(conn, true))
230 return;
231 conn->asyncStatus = PGASYNC_READY;
232 break;
233 case 'Z': /* sync response, backend is ready for new
234 * query */
235 if (getReadyForQuery(conn))
236 return;
237 if (conn->pipelineStatus != PQ_PIPELINE_OFF)
238 {
239 conn->result = PQmakeEmptyPGresult(conn,
240 PGRES_PIPELINE_SYNC);
241 if (!conn->result)
242 {
243 appendPQExpBufferStr(&conn->errorMessage,
244 libpq_gettext("out of memory"));
245 pqSaveErrorResult(conn);
246 }
247 else
248 {
249 conn->pipelineStatus = PQ_PIPELINE_ON;
250 conn->asyncStatus = PGASYNC_READY;
251 }
252 }
253 else
254 {
255 /*
256 * In simple query protocol, advance the command queue
257 * (see PQgetResult).
258 */
259 if (conn->cmd_queue_head &&
260 conn->cmd_queue_head->queryclass == PGQUERY_SIMPLE)
261 pqCommandQueueAdvance(conn);
262 conn->asyncStatus = PGASYNC_IDLE;
263 }
264 break;
265 case 'I': /* empty query */
266 if (conn->result == NULL)
267 {
268 conn->result = PQmakeEmptyPGresult(conn,
269 PGRES_EMPTY_QUERY);
270 if (!conn->result)
271 {
272 appendPQExpBufferStr(&conn->errorMessage,
273 libpq_gettext("out of memory"));
274 pqSaveErrorResult(conn);
275 }
276 }
277 conn->asyncStatus = PGASYNC_READY;
278 break;
279 case '1': /* Parse Complete */
280 /* If we're doing PQprepare, we're done; else ignore */
281 if (conn->cmd_queue_head &&
282 conn->cmd_queue_head->queryclass == PGQUERY_PREPARE)
283 {
284 if (conn->result == NULL)
285 {
286 conn->result = PQmakeEmptyPGresult(conn,
287 PGRES_COMMAND_OK);
288 if (!conn->result)
289 {
290 appendPQExpBufferStr(&conn->errorMessage,
291 libpq_gettext("out of memory"));
292 pqSaveErrorResult(conn);
293 }
294 }
295 conn->asyncStatus = PGASYNC_READY;
296 }
297 break;
298 case '2': /* Bind Complete */
299 case '3': /* Close Complete */
300 /* Nothing to do for these message types */
301 break;
302 case 'S': /* parameter status */
303 if (getParameterStatus(conn))
304 return;
305 break;
306 case 'K': /* secret key data from the backend */
307
308 /*
309 * This is expected only during backend startup, but it's
310 * just as easy to handle it as part of the main loop.
311 * Save the data and continue processing.
312 */
313 if (pqGetInt(&(conn->be_pid), 4, conn))
314 return;
315 if (pqGetInt(&(conn->be_key), 4, conn))
316 return;
317 break;
318 case 'T': /* Row Description */
319 if (conn->result != NULL &&
320 conn->result->resultStatus == PGRES_FATAL_ERROR)
321 {
322 /*
323 * We've already choked for some reason. Just discard
324 * the data till we get to the end of the query.
325 */
326 conn->inCursor += msgLength;
327 }
328 else if (conn->result == NULL ||
329 (conn->cmd_queue_head &&
330 conn->cmd_queue_head->queryclass == PGQUERY_DESCRIBE))
331 {
332 /* First 'T' in a query sequence */
333 if (getRowDescriptions(conn, msgLength))
334 return;
335 }
336 else
337 {
338 /*
339 * A new 'T' message is treated as the start of
340 * another PGresult. (It is not clear that this is
341 * really possible with the current backend.) We stop
342 * parsing until the application accepts the current
343 * result.
344 */
345 conn->asyncStatus = PGASYNC_READY;
346 return;
347 }
348 break;
349 case 'n': /* No Data */
350
351 /*
352 * NoData indicates that we will not be seeing a
353 * RowDescription message because the statement or portal
354 * inquired about doesn't return rows.
355 *
356 * If we're doing a Describe, we have to pass something
357 * back to the client, so set up a COMMAND_OK result,
358 * instead of PGRES_TUPLES_OK. Otherwise we can just
359 * ignore this message.
360 */
361 if (conn->cmd_queue_head &&
362 conn->cmd_queue_head->queryclass == PGQUERY_DESCRIBE)
363 {
364 if (conn->result == NULL)
365 {
366 conn->result = PQmakeEmptyPGresult(conn,
367 PGRES_COMMAND_OK);
368 if (!conn->result)
369 {
370 appendPQExpBufferStr(&conn->errorMessage,
371 libpq_gettext("out of memory"));
372 pqSaveErrorResult(conn);
373 }
374 }
375 conn->asyncStatus = PGASYNC_READY;
376 }
377 break;
378 case 't': /* Parameter Description */
379 if (getParamDescriptions(conn, msgLength))
380 return;
381 break;
382 case 'D': /* Data Row */
383 if (conn->result != NULL &&
384 conn->result->resultStatus == PGRES_TUPLES_OK)
385 {
386 /* Read another tuple of a normal query response */
387 if (getAnotherTuple(conn, msgLength))
388 return;
389 }
390 else if (conn->result != NULL &&
391 conn->result->resultStatus == PGRES_FATAL_ERROR)
392 {
393 /*
394 * We've already choked for some reason. Just discard
395 * tuples till we get to the end of the query.
396 */
397 conn->inCursor += msgLength;
398 }
399 else
400 {
401 /* Set up to report error at end of query */
402 appendPQExpBufferStr(&conn->errorMessage,
403 libpq_gettext("server sent data (\"D\" message) without prior row description (\"T\" message)\n"));
404 pqSaveErrorResult(conn);
405 /* Discard the unexpected message */
406 conn->inCursor += msgLength;
407 }
408 break;
409 case 'G': /* Start Copy In */
410 if (getCopyStart(conn, PGRES_COPY_IN))
411 return;
412 conn->asyncStatus = PGASYNC_COPY_IN;
413 break;
414 case 'H': /* Start Copy Out */
415 if (getCopyStart(conn, PGRES_COPY_OUT))
416 return;
417 conn->asyncStatus = PGASYNC_COPY_OUT;
418 conn->copy_already_done = 0;
419 break;
420 case 'W': /* Start Copy Both */
421 if (getCopyStart(conn, PGRES_COPY_BOTH))
422 return;
423 conn->asyncStatus = PGASYNC_COPY_BOTH;
424 conn->copy_already_done = 0;
425 break;
426 case 'd': /* Copy Data */
427
428 /*
429 * If we see Copy Data, just silently drop it. This would
430 * only occur if application exits COPY OUT mode too
431 * early.
432 */
433 conn->inCursor += msgLength;
434 break;
435 case 'c': /* Copy Done */
436
437 /*
438 * If we see Copy Done, just silently drop it. This is
439 * the normal case during PQendcopy. We will keep
440 * swallowing data, expecting to see command-complete for
441 * the COPY command.
442 */
443 break;
444 default:
445 appendPQExpBuffer(&conn->errorMessage,
446 libpq_gettext("unexpected response from server; first received character was \"%c\"\n"),
447 id);
448 /* build an error result holding the error message */
449 pqSaveErrorResult(conn);
450 /* not sure if we will see more, so go to ready state */
451 conn->asyncStatus = PGASYNC_READY;
452 /* Discard the unexpected message */
453 conn->inCursor += msgLength;
454 break;
455 } /* switch on protocol character */
456 }
457 /* Successfully consumed this message */
458 if (conn->inCursor == conn->inStart + 5 + msgLength)
459 {
460 /* trace server-to-client message */
461 if (conn->Pfdebug)
462 pqTraceOutputMessage(conn, conn->inBuffer + conn->inStart, false);
463
464 /* Normal case: parsing agrees with specified length */
465 conn->inStart = conn->inCursor;
466 }
467 else
468 {
469 /* Trouble --- report it */
470 appendPQExpBuffer(&conn->errorMessage,
471 libpq_gettext("message contents do not agree with length in message type \"%c\"\n"),
472 id);
473 /* build an error result holding the error message */
474 pqSaveErrorResult(conn);
475 conn->asyncStatus = PGASYNC_READY;
476 /* trust the specified message length as what to skip */
477 conn->inStart += 5 + msgLength;
478 }
479 }
480 }
481
482 /*
483 * handleSyncLoss: clean up after loss of message-boundary sync
484 *
485 * There isn't really a lot we can do here except abandon the connection.
486 */
487 static void
488 handleSyncLoss(PGconn *conn, char id, int msgLength)
489 {
490 appendPQExpBuffer(&conn->errorMessage,
491 libpq_gettext("lost synchronization with server: got message type \"%c\", length %d\n"),
492 id, msgLength);
493 /* build an error result holding the error message */
494 pqSaveErrorResult(conn);
495 conn->asyncStatus = PGASYNC_READY; /* drop out of PQgetResult wait loop */
496 /* flush input data since we're giving up on processing it */
497 pqDropConnection(conn, true);
498 conn->status = CONNECTION_BAD; /* No more connection to backend */
499 }
500
501 /*
502 * parseInput subroutine to read a 'T' (row descriptions) message.
503 * We'll build a new PGresult structure (unless called for a Describe
504 * command for a prepared statement) containing the attribute data.
505 * Returns: 0 if processed message successfully, EOF to suspend parsing
506 * (the latter case is not actually used currently).
507 */
508 static int
509 getRowDescriptions(PGconn *conn, int msgLength)
510 {
511 PGresult *result;
512 int nfields;
513 const char *errmsg;
514 int i;
515
516 /*
517 * When doing Describe for a prepared statement, there'll already be a
518 * PGresult created by getParamDescriptions, and we should fill data into
519 * that. Otherwise, create a new, empty PGresult.
520 */
521 if (!conn->cmd_queue_head ||
522 (conn->cmd_queue_head &&
523 conn->cmd_queue_head->queryclass == PGQUERY_DESCRIBE))
524 {
525 if (conn->result)
526 result = conn->result;
527 else
528 result = PQmakeEmptyPGresult(conn, PGRES_COMMAND_OK);
529 }
530 else
531 result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
532 if (!result)
533 {
534 errmsg = NULL; /* means "out of memory", see below */
535 goto advance_and_error;
536 }
537
538 /* parseInput already read the 'T' label and message length. */
539 /* the next two bytes are the number of fields */
540 if (pqGetInt(&(result->numAttributes), 2, conn))
541 {
542 /* We should not run out of data here, so complain */
543 errmsg = libpq_gettext("insufficient data in \"T\" message");
544 goto advance_and_error;
545 }
546 nfields = result->numAttributes;
547
548 /* allocate space for the attribute descriptors */
549 if (nfields > 0)
550 {
551 result->attDescs = (PGresAttDesc *)
552 pqResultAlloc(result, nfields * sizeof(PGresAttDesc), true);
553 if (!result->attDescs)
554 {
555 errmsg = NULL; /* means "out of memory", see below */
556 goto advance_and_error;
557 }
558 MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc));
559 }
560
561 /* result->binary is true only if ALL columns are binary */
562 result->binary = (nfields > 0) ? 1 : 0;
563
564 /* get type info */
565 for (i = 0; i < nfields; i++)
566 {
567 int tableid;
568 int columnid;
569 int typid;
570 int typlen;
571 int atttypmod;
572 int format;
573
574 if (pqGets(&conn->workBuffer, conn) ||
575 pqGetInt(&tableid, 4, conn) ||
576 pqGetInt(&columnid, 2, conn) ||
577 pqGetInt(&typid, 4, conn) ||
578 pqGetInt(&typlen, 2, conn) ||
579 pqGetInt(&atttypmod, 4, conn) ||
580 pqGetInt(&format, 2, conn))
581 {
582 /* We should not run out of data here, so complain */
583 errmsg = libpq_gettext("insufficient data in \"T\" message");
584 goto advance_and_error;
585 }
586
587 /*
588 * Since pqGetInt treats 2-byte integers as unsigned, we need to
589 * coerce these results to signed form.
590 */
591 columnid = (int) ((int16) columnid);
592 typlen = (int) ((int16) typlen);
593 format = (int) ((int16) format);
594
595 result->attDescs[i].name = pqResultStrdup(result,
596 conn->workBuffer.data);
597 if (!result->attDescs[i].name)
598 {
599 errmsg = NULL; /* means "out of memory", see below */
600 goto advance_and_error;
601 }
602 result->attDescs[i].tableid = tableid;
603 result->attDescs[i].columnid = columnid;
604 result->attDescs[i].format = format;
605 result->attDescs[i].typid = typid;
606 result->attDescs[i].typlen = typlen;
607 result->attDescs[i].atttypmod = atttypmod;
608
609 if (format != 1)
610 result->binary = 0;
611 }
612
613 /* Success! */
614 conn->result = result;
615
616 /*
617 * If we're doing a Describe, we're done, and ready to pass the result
618 * back to the client.
619 */
620 if ((!conn->cmd_queue_head) ||
621 (conn->cmd_queue_head &&
622 conn->cmd_queue_head->queryclass == PGQUERY_DESCRIBE))
623 {
624 conn->asyncStatus = PGASYNC_READY;
625 return 0;
626 }
627
628 /*
629 * We could perform additional setup for the new result set here, but for
630 * now there's nothing else to do.
631 */
632
633 /* And we're done. */
634 return 0;
635
636 advance_and_error:
637 /* Discard unsaved result, if any */
638 if (result && result != conn->result)
639 PQclear(result);
640
641 /*
642 * Replace partially constructed result with an error result. First
643 * discard the old result to try to win back some memory.
644 */
645 pqClearAsyncResult(conn);
646
647 /*
648 * If preceding code didn't provide an error message, assume "out of
649 * memory" was meant. The advantage of having this special case is that
650 * freeing the old result first greatly improves the odds that gettext()
651 * will succeed in providing a translation.
652 */
653 if (!errmsg)
654 errmsg = libpq_gettext("out of memory for query result");
655
656 appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
657 pqSaveErrorResult(conn);
658
659 /*
660 * Show the message as fully consumed, else pqParseInput3 will overwrite
661 * our error with a complaint about that.
662 */
663 conn->inCursor = conn->inStart + 5 + msgLength;
664
665 /*
666 * Return zero to allow input parsing to continue. Subsequent "D"
667 * messages will be ignored until we get to end of data, since an error
668 * result is already set up.
669 */
670 return 0;
671 }
672
673 /*
674 * parseInput subroutine to read a 't' (ParameterDescription) message.
675 * We'll build a new PGresult structure containing the parameter data.
676 * Returns: 0 if processed message successfully, EOF to suspend parsing
677 * (the latter case is not actually used currently).
678 */
679 static int
680 getParamDescriptions(PGconn *conn, int msgLength)
681 {
682 PGresult *result;
683 const char *errmsg = NULL; /* means "out of memory", see below */
684 int nparams;
685 int i;
686
687 result = PQmakeEmptyPGresult(conn, PGRES_COMMAND_OK);
688 if (!result)
689 goto advance_and_error;
690
691 /* parseInput already read the 't' label and message length. */
692 /* the next two bytes are the number of parameters */
693 if (pqGetInt(&(result->numParameters), 2, conn))
694 goto not_enough_data;
695 nparams = result->numParameters;
696
697 /* allocate space for the parameter descriptors */
698 if (nparams > 0)
699 {
700 result->paramDescs = (PGresParamDesc *)
701 pqResultAlloc(result, nparams * sizeof(PGresParamDesc), true);
702 if (!result->paramDescs)
703 goto advance_and_error;
704 MemSet(result->paramDescs, 0, nparams * sizeof(PGresParamDesc));
705 }
706
707 /* get parameter info */
708 for (i = 0; i < nparams; i++)
709 {
710 int typid;
711
712 if (pqGetInt(&typid, 4, conn))
713 goto not_enough_data;
714 result->paramDescs[i].typid = typid;
715 }
716
717 /* Success! */
718 conn->result = result;
719
720 return 0;
721
722 not_enough_data:
723 errmsg = libpq_gettext("insufficient data in \"t\" message");
724
725 advance_and_error:
726 /* Discard unsaved result, if any */
727 if (result && result != conn->result)
728 PQclear(result);
729
730 /*
731 * Replace partially constructed result with an error result. First
732 * discard the old result to try to win back some memory.
733 */
734 pqClearAsyncResult(conn);
735
736 /*
737 * If preceding code didn't provide an error message, assume "out of
738 * memory" was meant. The advantage of having this special case is that
739 * freeing the old result first greatly improves the odds that gettext()
740 * will succeed in providing a translation.
741 */
742 if (!errmsg)
743 errmsg = libpq_gettext("out of memory");
744 appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
745 pqSaveErrorResult(conn);
746
747 /*
748 * Show the message as fully consumed, else pqParseInput3 will overwrite
749 * our error with a complaint about that.
750 */
751 conn->inCursor = conn->inStart + 5 + msgLength;
752
753 /*
754 * Return zero to allow input parsing to continue. Essentially, we've
755 * replaced the COMMAND_OK result with an error result, but since this
756 * doesn't affect the protocol state, it's fine.
757 */
758 return 0;
759 }
760
761 /*
762 * parseInput subroutine to read a 'D' (row data) message.
763 * We fill rowbuf with column pointers and then call the row processor.
764 * Returns: 0 if processed message successfully, EOF to suspend parsing
765 * (the latter case is not actually used currently).
766 */
767 static int
768 getAnotherTuple(PGconn *conn, int msgLength)
769 {
770 PGresult *result = conn->result;
771 int nfields = result->numAttributes;
772 const char *errmsg;
773 PGdataValue *rowbuf;
774 int tupnfields; /* # fields from tuple */
775 int vlen; /* length of the current field value */
776 int i;
777
778 /* Get the field count and make sure it's what we expect */
779 if (pqGetInt(&tupnfields, 2, conn))
780 {
781 /* We should not run out of data here, so complain */
782 errmsg = libpq_gettext("insufficient data in \"D\" message");
783 goto advance_and_error;
784 }
785
786 if (tupnfields != nfields)
787 {
788 errmsg = libpq_gettext("unexpected field count in \"D\" message");
789 goto advance_and_error;
790 }
791
792 /* Resize row buffer if needed */
793 rowbuf = conn->rowBuf;
794 if (nfields > conn->rowBufLen)
795 {
796 rowbuf = (PGdataValue *) realloc(rowbuf,
797 nfields * sizeof(PGdataValue));
798 if (!rowbuf)
799 {
800 errmsg = NULL; /* means "out of memory", see below */
801 goto advance_and_error;
802 }
803 conn->rowBuf = rowbuf;
804 conn->rowBufLen = nfields;
805 }
806
807 /* Scan the fields */
808 for (i = 0; i < nfields; i++)
809 {
810 /* get the value length */
811 if (pqGetInt(&vlen, 4, conn))
812 {
813 /* We should not run out of data here, so complain */
814 errmsg = libpq_gettext("insufficient data in \"D\" message");
815 goto advance_and_error;
816 }
817 rowbuf[i].len = vlen;
818
819 /*
820 * rowbuf[i].value always points to the next address in the data
821 * buffer even if the value is NULL. This allows row processors to
822 * estimate data sizes more easily.
823 */
824 rowbuf[i].value = conn->inBuffer + conn->inCursor;
825
826 /* Skip over the data value */
827 if (vlen > 0)
828 {
829 if (pqSkipnchar(vlen, conn))
830 {
831 /* We should not run out of data here, so complain */
832 errmsg = libpq_gettext("insufficient data in \"D\" message");
833 goto advance_and_error;
834 }
835 }
836 }
837
838 /* Process the collected row */
839 errmsg = NULL;
840 if (pqRowProcessor(conn, &errmsg))
841 return 0; /* normal, successful exit */
842
843 /* pqRowProcessor failed, fall through to report it */
844
845 advance_and_error:
846
847 /*
848 * Replace partially constructed result with an error result. First
849 * discard the old result to try to win back some memory.
850 */
851 pqClearAsyncResult(conn);
852
853 /*
854 * If preceding code didn't provide an error message, assume "out of
855 * memory" was meant. The advantage of having this special case is that
856 * freeing the old result first greatly improves the odds that gettext()
857 * will succeed in providing a translation.
858 */
859 if (!errmsg)
860 errmsg = libpq_gettext("out of memory for query result");
861
862 appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
863 pqSaveErrorResult(conn);
864
865 /*
866 * Show the message as fully consumed, else pqParseInput3 will overwrite
867 * our error with a complaint about that.
868 */
869 conn->inCursor = conn->inStart + 5 + msgLength;
870
871 /*
872 * Return zero to allow input parsing to continue. Subsequent "D"
873 * messages will be ignored until we get to end of data, since an error
874 * result is already set up.
875 */
876 return 0;
877 }
878
879
880 /*
881 * Attempt to read an Error or Notice response message.
882 * This is possible in several places, so we break it out as a subroutine.
883 * Entry: 'E' or 'N' message type and length have already been consumed.
884 * Exit: returns 0 if successfully consumed message.
885 * returns EOF if not enough data.
886 */
887 int
888 pqGetErrorNotice3(PGconn *conn, bool isError)
889 {
890 PGresult *res = NULL;
891 bool have_position = false;
892 PQExpBufferData workBuf;
893 char id;
894
895 /* If in pipeline mode, set error indicator for it */
896 if (isError && conn->pipelineStatus != PQ_PIPELINE_OFF)
897 conn->pipelineStatus = PQ_PIPELINE_ABORTED;
898
899 /*
900 * If this is an error message, pre-emptively clear any incomplete query
901 * result we may have. We'd just throw it away below anyway, and
902 * releasing it before collecting the error might avoid out-of-memory.
903 */
904 if (isError)
905 pqClearAsyncResult(conn);
906
907 /*
908 * Since the fields might be pretty long, we create a temporary
909 * PQExpBuffer rather than using conn->workBuffer. workBuffer is intended
910 * for stuff that is expected to be short. We shouldn't use
911 * conn->errorMessage either, since this might be only a notice.
912 */
913 initPQExpBuffer(&workBuf);
914
915 /*
916 * Make a PGresult to hold the accumulated fields. We temporarily lie
917 * about the result status, so that PQmakeEmptyPGresult doesn't uselessly
918 * copy conn->errorMessage.
919 *
920 * NB: This allocation can fail, if you run out of memory. The rest of the
921 * function handles that gracefully, and we still try to set the error
922 * message as the connection's error message.
923 */
924 res = PQmakeEmptyPGresult(conn, PGRES_EMPTY_QUERY);
925 if (res)
926 res->resultStatus = isError ? PGRES_FATAL_ERROR : PGRES_NONFATAL_ERROR;
927
928 /*
929 * Read the fields and save into res.
930 *
931 * While at it, save the SQLSTATE in conn->last_sqlstate, and note whether
932 * we saw a PG_DIAG_STATEMENT_POSITION field.
933 */
934 for (;;)
935 {
936 if (pqGetc(&id, conn))
937 goto fail;
938 if (id == '\0')
939 break; /* terminator found */
940 if (pqGets(&workBuf, conn))
941 goto fail;
942 pqSaveMessageField(res, id, workBuf.data);
943 if (id == PG_DIAG_SQLSTATE)
944 strlcpy(conn->last_sqlstate, workBuf.data,
945 sizeof(conn->last_sqlstate));
946 else if (id == PG_DIAG_STATEMENT_POSITION)
947 have_position = true;
948 }
949
950 /*
951 * Save the active query text, if any, into res as well; but only if we
952 * might need it for an error cursor display, which is only true if there
953 * is a PG_DIAG_STATEMENT_POSITION field.
954 */
955 if (have_position && res && conn->cmd_queue_head && conn->cmd_queue_head->query)
956 res->errQuery = pqResultStrdup(res, conn->cmd_queue_head->query);
957
958 /*
959 * Now build the "overall" error message for PQresultErrorMessage.
960 */
961 resetPQExpBuffer(&workBuf);
962 pqBuildErrorMessage3(&workBuf, res, conn->verbosity, conn->show_context);
963
964 /*
965 * Either save error as current async result, or just emit the notice.
966 */
967 if (isError)
968 {
969 if (res)
970 pqSetResultError(res, &workBuf);
971 pqClearAsyncResult(conn); /* redundant, but be safe */
972 conn->result = res;
973 if (PQExpBufferDataBroken(workBuf))
974 appendPQExpBufferStr(&conn->errorMessage,
975 libpq_gettext("out of memory\n"));
976 else
977 appendPQExpBufferStr(&conn->errorMessage, workBuf.data);
978 }
979 else
980 {
981 /* if we couldn't allocate the result set, just discard the NOTICE */
982 if (res)
983 {
984 /*
985 * We can cheat a little here and not copy the message. But if we
986 * were unlucky enough to run out of memory while filling workBuf,
987 * insert "out of memory", as in pqSetResultError.
988 */
989 if (PQExpBufferDataBroken(workBuf))
990 res->errMsg = libpq_gettext("out of memory\n");
991 else
992 res->errMsg = workBuf.data;
993 if (res->noticeHooks.noticeRec != NULL)
994 res->noticeHooks.noticeRec(res->noticeHooks.noticeRecArg, res);
995 PQclear(res);
996 }
997 }
998
999 termPQExpBuffer(&workBuf);
1000 return 0;
1001
1002 fail:
1003 PQclear(res);
1004 termPQExpBuffer(&workBuf);
1005 return EOF;
1006 }
1007
1008 /*
1009 * Construct an error message from the fields in the given PGresult,
1010 * appending it to the contents of "msg".
1011 */
1012 void
1013 pqBuildErrorMessage3(PQExpBuffer msg, const PGresult *res,
1014 PGVerbosity verbosity, PGContextVisibility show_context)
1015 {
1016 const char *val;
1017 const char *querytext = NULL;
1018 int querypos = 0;
1019
1020 /* If we couldn't allocate a PGresult, just say "out of memory" */
1021 if (res == NULL)
1022 {
1023 appendPQExpBufferStr(msg, libpq_gettext("out of memory\n"));
1024 return;
1025 }
1026
1027 /*
1028 * If we don't have any broken-down fields, just return the base message.
1029 * This mainly applies if we're given a libpq-generated error result.
1030 */
1031 if (res->errFields == NULL)
1032 {
1033 if (res->errMsg && res->errMsg[0])
1034 appendPQExpBufferStr(msg, res->errMsg);
1035 else
1036 appendPQExpBufferStr(msg, libpq_gettext("no error message available\n"));
1037 return;
1038 }
1039
1040 /* Else build error message from relevant fields */
1041 val = PQresultErrorField(res, PG_DIAG_SEVERITY);
1042 if (val)
1043 appendPQExpBuffer(msg, "%s: ", val);
1044
1045 if (verbosity == PQERRORS_SQLSTATE)
1046 {
1047 /*
1048 * If we have a SQLSTATE, print that and nothing else. If not (which
1049 * shouldn't happen for server-generated errors, but might possibly
1050 * happen for libpq-generated ones), fall back to TERSE format, as
1051 * that seems better than printing nothing at all.
1052 */
1053 val = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1054 if (val)
1055 {
1056 appendPQExpBuffer(msg, "%s\n", val);
1057 return;
1058 }
1059 verbosity = PQERRORS_TERSE;
1060 }
1061
1062 if (verbosity == PQERRORS_VERBOSE)
1063 {
1064 val = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1065 if (val)
1066 appendPQExpBuffer(msg, "%s: ", val);
1067 }
1068 val = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1069 if (val)
1070 appendPQExpBufferStr(msg, val);
1071 val = PQresultErrorField(res, PG_DIAG_STATEMENT_POSITION);
1072 if (val)
1073 {
1074 if (verbosity != PQERRORS_TERSE && res->errQuery != NULL)
1075 {
1076 /* emit position as a syntax cursor display */
1077 querytext = res->errQuery;
1078 querypos = atoi(val);
1079 }
1080 else
1081 {
1082 /* emit position as text addition to primary message */
1083 /* translator: %s represents a digit string */
1084 appendPQExpBuffer(msg, libpq_gettext(" at character %s"),
1085 val);
1086 }
1087 }
1088 else
1089 {
1090 val = PQresultErrorField(res, PG_DIAG_INTERNAL_POSITION);
1091 if (val)
1092 {
1093 querytext = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
1094 if (verbosity != PQERRORS_TERSE && querytext != NULL)
1095 {
1096 /* emit position as a syntax cursor display */
1097 querypos = atoi(val);
1098 }
1099 else
1100 {
1101 /* emit position as text addition to primary message */
1102 /* translator: %s represents a digit string */
1103 appendPQExpBuffer(msg, libpq_gettext(" at character %s"),
1104 val);
1105 }
1106 }
1107 }
1108 appendPQExpBufferChar(msg, '\n');
1109 if (verbosity != PQERRORS_TERSE)
1110 {
1111 if (querytext && querypos > 0)
1112 reportErrorPosition(msg, querytext, querypos,
1113 res->client_encoding);
1114 val = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL);
1115 if (val)
1116 appendPQExpBuffer(msg, libpq_gettext("DETAIL: %s\n"), val);
1117 val = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT);
1118 if (val)
1119 appendPQExpBuffer(msg, libpq_gettext("HINT: %s\n"), val);
1120 val = PQresultErrorField(res, PG_DIAG_INTERNAL_QUERY);
1121 if (val)
1122 appendPQExpBuffer(msg, libpq_gettext("QUERY: %s\n"), val);
1123 if (show_context == PQSHOW_CONTEXT_ALWAYS ||
1124 (show_context == PQSHOW_CONTEXT_ERRORS &&
1125 res->resultStatus == PGRES_FATAL_ERROR))
1126 {
1127 val = PQresultErrorField(res, PG_DIAG_CONTEXT);
1128 if (val)
1129 appendPQExpBuffer(msg, libpq_gettext("CONTEXT: %s\n"),
1130 val);
1131 }
1132 }
1133 if (verbosity == PQERRORS_VERBOSE)
1134 {
1135 val = PQresultErrorField(res, PG_DIAG_SCHEMA_NAME);
1136 if (val)
1137 appendPQExpBuffer(msg,
1138 libpq_gettext("SCHEMA NAME: %s\n"), val);
1139 val = PQresultErrorField(res, PG_DIAG_TABLE_NAME);
1140 if (val)
1141 appendPQExpBuffer(msg,
1142 libpq_gettext("TABLE NAME: %s\n"), val);
1143 val = PQresultErrorField(res, PG_DIAG_COLUMN_NAME);
1144 if (val)
1145 appendPQExpBuffer(msg,
1146 libpq_gettext("COLUMN NAME: %s\n"), val);
1147 val = PQresultErrorField(res, PG_DIAG_DATATYPE_NAME);
1148 if (val)
1149 appendPQExpBuffer(msg,
1150 libpq_gettext("DATATYPE NAME: %s\n"), val);
1151 val = PQresultErrorField(res, PG_DIAG_CONSTRAINT_NAME);
1152 if (val)
1153 appendPQExpBuffer(msg,
1154 libpq_gettext("CONSTRAINT NAME: %s\n"), val);
1155 }
1156 if (verbosity == PQERRORS_VERBOSE)
1157 {
1158 const char *valf;
1159 const char *vall;
1160
1161 valf = PQresultErrorField(res, PG_DIAG_SOURCE_FILE);
1162 vall = PQresultErrorField(res, PG_DIAG_SOURCE_LINE);
1163 val = PQresultErrorField(res, PG_DIAG_SOURCE_FUNCTION);
1164 if (val || valf || vall)
1165 {
1166 appendPQExpBufferStr(msg, libpq_gettext("LOCATION: "));
1167 if (val)
1168 appendPQExpBuffer(msg, libpq_gettext("%s, "), val);
1169 if (valf && vall) /* unlikely we'd have just one */
1170 appendPQExpBuffer(msg, libpq_gettext("%s:%s"),
1171 valf, vall);
1172 appendPQExpBufferChar(msg, '\n');
1173 }
1174 }
1175 }
1176
1177 /*
1178 * Add an error-location display to the error message under construction.
1179 *
1180 * The cursor location is measured in logical characters; the query string
1181 * is presumed to be in the specified encoding.
1182 */
1183 static void
1184 reportErrorPosition(PQExpBuffer msg, const char *query, int loc, int encoding)
1185 {
1186 #define DISPLAY_SIZE 60 /* screen width limit, in screen cols */
1187 #define MIN_RIGHT_CUT 10 /* try to keep this far away from EOL */
1188
1189 char *wquery;
1190 int slen,
1191 cno,
1192 i,
1193 *qidx,
1194 *scridx,
1195 qoffset,
1196 scroffset,
1197 ibeg,
1198 iend,
1199 loc_line;
1200 bool mb_encoding,
1201 beg_trunc,
1202 end_trunc;
1203
1204 /* Convert loc from 1-based to 0-based; no-op if out of range */
1205 loc--;
1206 if (loc < 0)
1207 return;
1208
1209 /* Need a writable copy of the query */
1210 wquery = strdup(query);
1211 if (wquery == NULL)
1212 return; /* fail silently if out of memory */
1213
1214 /*
1215 * Each character might occupy multiple physical bytes in the string, and
1216 * in some Far Eastern character sets it might take more than one screen
1217 * column as well. We compute the starting byte offset and starting
1218 * screen column of each logical character, and store these in qidx[] and
1219 * scridx[] respectively.
1220 */
1221
1222 /* we need a safe allocation size... */
1223 slen = strlen(wquery) + 1;
1224
1225 qidx = (int *) malloc(slen * sizeof(int));
1226 if (qidx == NULL)
1227 {
1228 free(wquery);
1229 return;
1230 }
1231 scridx = (int *) malloc(slen * sizeof(int));
1232 if (scridx == NULL)
1233 {
1234 free(qidx);
1235 free(wquery);
1236 return;
1237 }
1238
1239 /* We can optimize a bit if it's a single-byte encoding */
1240 mb_encoding = (pg_encoding_max_length(encoding) != 1);
1241
1242 /*
1243 * Within the scanning loop, cno is the current character's logical
1244 * number, qoffset is its offset in wquery, and scroffset is its starting
1245 * logical screen column (all indexed from 0). "loc" is the logical
1246 * character number of the error location. We scan to determine loc_line
1247 * (the 1-based line number containing loc) and ibeg/iend (first character
1248 * number and last+1 character number of the line containing loc). Note
1249 * that qidx[] and scridx[] are filled only as far as iend.
1250 */
1251 qoffset = 0;
1252 scroffset = 0;
1253 loc_line = 1;
1254 ibeg = 0;
1255 iend = -1; /* -1 means not set yet */
1256
1257 for (cno = 0; wquery[qoffset] != '\0'; cno++)
1258 {
1259 char ch = wquery[qoffset];
1260
1261 qidx[cno] = qoffset;
1262 scridx[cno] = scroffset;
1263
1264 /*
1265 * Replace tabs with spaces in the writable copy. (Later we might
1266 * want to think about coping with their variable screen width, but
1267 * not today.)
1268 */
1269 if (ch == '\t')
1270 wquery[qoffset] = ' ';
1271
1272 /*
1273 * If end-of-line, count lines and mark positions. Each \r or \n
1274 * counts as a line except when \r \n appear together.
1275 */
1276 else if (ch == '\r' || ch == '\n')
1277 {
1278 if (cno < loc)
1279 {
1280 if (ch == '\r' ||
1281 cno == 0 ||
1282 wquery[qidx[cno - 1]] != '\r')
1283 loc_line++;
1284 /* extract beginning = last line start before loc. */
1285 ibeg = cno + 1;
1286 }
1287 else
1288 {
1289 /* set extract end. */
1290 iend = cno;
1291 /* done scanning. */
1292 break;
1293 }
1294 }
1295
1296 /* Advance */
1297 if (mb_encoding)
1298 {
1299 int w;
1300
1301 w = pg_encoding_dsplen(encoding, &wquery[qoffset]);
1302 /* treat any non-tab control chars as width 1 */
1303 if (w <= 0)
1304 w = 1;
1305 scroffset += w;
1306 qoffset += PQmblenBounded(&wquery[qoffset], encoding);
1307 }
1308 else
1309 {
1310 /* We assume wide chars only exist in multibyte encodings */
1311 scroffset++;
1312 qoffset++;
1313 }
1314 }
1315 /* Fix up if we didn't find an end-of-line after loc */
1316 if (iend < 0)
1317 {
1318 iend = cno; /* query length in chars, +1 */
1319 qidx[iend] = qoffset;
1320 scridx[iend] = scroffset;
1321 }
1322
1323 /* Print only if loc is within computed query length */
1324 if (loc <= cno)
1325 {
1326 /* If the line extracted is too long, we truncate it. */
1327 beg_trunc = false;
1328 end_trunc = false;
1329 if (scridx[iend] - scridx[ibeg] > DISPLAY_SIZE)
1330 {
1331 /*
1332 * We first truncate right if it is enough. This code might be
1333 * off a space or so on enforcing MIN_RIGHT_CUT if there's a wide
1334 * character right there, but that should be okay.
1335 */
1336 if (scridx[ibeg] + DISPLAY_SIZE >= scridx[loc] + MIN_RIGHT_CUT)
1337 {
1338 while (scridx[iend] - scridx[ibeg] > DISPLAY_SIZE)
1339 iend--;
1340 end_trunc = true;
1341 }
1342 else
1343 {
1344 /* Truncate right if not too close to loc. */
1345 while (scridx[loc] + MIN_RIGHT_CUT < scridx[iend])
1346 {
1347 iend--;
1348 end_trunc = true;
1349 }
1350
1351 /* Truncate left if still too long. */
1352 while (scridx[iend] - scridx[ibeg] > DISPLAY_SIZE)
1353 {
1354 ibeg++;
1355 beg_trunc = true;
1356 }
1357 }
1358 }
1359
1360 /* truncate working copy at desired endpoint */
1361 wquery[qidx[iend]] = '\0';
1362
1363 /* Begin building the finished message. */
1364 i = msg->len;
1365 appendPQExpBuffer(msg, libpq_gettext("LINE %d: "), loc_line);
1366 if (beg_trunc)
1367 appendPQExpBufferStr(msg, "...");
1368
1369 /*
1370 * While we have the prefix in the msg buffer, compute its screen
1371 * width.
1372 */
1373 scroffset = 0;
1374 for (; i < msg->len; i += PQmblenBounded(&msg->data[i], encoding))
1375 {
1376 int w = pg_encoding_dsplen(encoding, &msg->data[i]);
1377
1378 if (w <= 0)
1379 w = 1;
1380 scroffset += w;
1381 }
1382
1383 /* Finish up the LINE message line. */
1384 appendPQExpBufferStr(msg, &wquery[qidx[ibeg]]);
1385 if (end_trunc)
1386 appendPQExpBufferStr(msg, "...");
1387 appendPQExpBufferChar(msg, '\n');
1388
1389 /* Now emit the cursor marker line. */
1390 scroffset += scridx[loc] - scridx[ibeg];
1391 for (i = 0; i < scroffset; i++)
1392 appendPQExpBufferChar(msg, ' ');
1393 appendPQExpBufferChar(msg, '^');
1394 appendPQExpBufferChar(msg, '\n');
1395 }
1396
1397 /* Clean up. */
1398 free(scridx);
1399 free(qidx);
1400 free(wquery);
1401 }
1402
1403
1404 /*
1405 * Attempt to read a ParameterStatus message.
1406 * This is possible in several places, so we break it out as a subroutine.
1407 * Entry: 'S' message type and length have already been consumed.
1408 * Exit: returns 0 if successfully consumed message.
1409 * returns EOF if not enough data.
1410 */
1411 static int
1412 getParameterStatus(PGconn *conn)
1413 {
1414 PQExpBufferData valueBuf;
1415
1416 /* Get the parameter name */
1417 if (pqGets(&conn->workBuffer, conn))
1418 return EOF;
1419 /* Get the parameter value (could be large) */
1420 initPQExpBuffer(&valueBuf);
1421 if (pqGets(&valueBuf, conn))
1422 {
1423 termPQExpBuffer(&valueBuf);
1424 return EOF;
1425 }
1426 /* And save it */
1427 pqSaveParameterStatus(conn, conn->workBuffer.data, valueBuf.data);
1428 termPQExpBuffer(&valueBuf);
1429 return 0;
1430 }
1431
1432
1433 /*
1434 * Attempt to read a Notify response message.
1435 * This is possible in several places, so we break it out as a subroutine.
1436 * Entry: 'A' message type and length have already been consumed.
1437 * Exit: returns 0 if successfully consumed Notify message.
1438 * returns EOF if not enough data.
1439 */
1440 static int
1441 getNotify(PGconn *conn)
1442 {
1443 int be_pid;
1444 char *svname;
1445 int nmlen;
1446 int extralen;
1447 PGnotify *newNotify;
1448
1449 if (pqGetInt(&be_pid, 4, conn))
1450 return EOF;
1451 if (pqGets(&conn->workBuffer, conn))
1452 return EOF;
1453 /* must save name while getting extra string */
1454 svname = strdup(conn->workBuffer.data);
1455 if (!svname)
1456 return EOF;
1457 if (pqGets(&conn->workBuffer, conn))
1458 {
1459 free(svname);
1460 return EOF;
1461 }
1462
1463 /*
1464 * Store the strings right after the PQnotify structure so it can all be
1465 * freed at once. We don't use NAMEDATALEN because we don't want to tie
1466 * this interface to a specific server name length.
1467 */
1468 nmlen = strlen(svname);
1469 extralen = strlen(conn->workBuffer.data);
1470 newNotify = (PGnotify *) malloc(sizeof(PGnotify) + nmlen + extralen + 2);
1471 if (newNotify)
1472 {
1473 newNotify->relname = (char *) newNotify + sizeof(PGnotify);
1474 strcpy(newNotify->relname, svname);
1475 newNotify->extra = newNotify->relname + nmlen + 1;
1476 strcpy(newNotify->extra, conn->workBuffer.data);
1477 newNotify->be_pid = be_pid;
1478 newNotify->next = NULL;
1479 if (conn->notifyTail)
1480 conn->notifyTail->next = newNotify;
1481 else
1482 conn->notifyHead = newNotify;
1483 conn->notifyTail = newNotify;
1484 }
1485
1486 free(svname);
1487 return 0;
1488 }
1489
1490 /*
1491 * getCopyStart - process CopyInResponse, CopyOutResponse or
1492 * CopyBothResponse message
1493 *
1494 * parseInput already read the message type and length.
1495 */
1496 static int
1497 getCopyStart(PGconn *conn, ExecStatusType copytype)
1498 {
1499 PGresult *result;
1500 int nfields;
1501 int i;
1502
1503 result = PQmakeEmptyPGresult(conn, copytype);
1504 if (!result)
1505 goto failure;
1506
1507 if (pqGetc(&conn->copy_is_binary, conn))
1508 goto failure;
1509 result->binary = conn->copy_is_binary;
1510 /* the next two bytes are the number of fields */
1511 if (pqGetInt(&(result->numAttributes), 2, conn))
1512 goto failure;
1513 nfields = result->numAttributes;
1514
1515 /* allocate space for the attribute descriptors */
1516 if (nfields > 0)
1517 {
1518 result->attDescs = (PGresAttDesc *)
1519 pqResultAlloc(result, nfields * sizeof(PGresAttDesc), true);
1520 if (!result->attDescs)
1521 goto failure;
1522 MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc));
1523 }
1524
1525 for (i = 0; i < nfields; i++)
1526 {
1527 int format;
1528
1529 if (pqGetInt(&format, 2, conn))
1530 goto failure;
1531
1532 /*
1533 * Since pqGetInt treats 2-byte integers as unsigned, we need to
1534 * coerce these results to signed form.
1535 */
1536 format = (int) ((int16) format);
1537 result->attDescs[i].format = format;
1538 }
1539
1540 /* Success! */
1541 conn->result = result;
1542 return 0;
1543
1544 failure:
1545 PQclear(result);
1546 return EOF;
1547 }
1548
1549 /*
1550 * getReadyForQuery - process ReadyForQuery message
1551 */
1552 static int
1553 getReadyForQuery(PGconn *conn)
1554 {
1555 char xact_status;
1556
1557 if (pqGetc(&xact_status, conn))
1558 return EOF;
1559 switch (xact_status)
1560 {
1561 case 'I':
1562 conn->xactStatus = PQTRANS_IDLE;
1563 break;
1564 case 'T':
1565 conn->xactStatus = PQTRANS_INTRANS;
1566 break;
1567 case 'E':
1568 conn->xactStatus = PQTRANS_INERROR;
1569 break;
1570 default:
1571 conn->xactStatus = PQTRANS_UNKNOWN;
1572 break;
1573 }
1574
1575 return 0;
1576 }
1577
1578 /*
1579 * getCopyDataMessage - fetch next CopyData message, process async messages
1580 *
1581 * Returns length word of CopyData message (> 0), or 0 if no complete
1582 * message available, -1 if end of copy, -2 if error.
1583 */
1584 static int
1585 getCopyDataMessage(PGconn *conn)
1586 {
1587 char id;
1588 int msgLength;
1589 int avail;
1590
1591 for (;;)
1592 {
1593 /*
1594 * Do we have the next input message? To make life simpler for async
1595 * callers, we keep returning 0 until the next message is fully
1596 * available, even if it is not Copy Data.
1597 */
1598 conn->inCursor = conn->inStart;
1599 if (pqGetc(&id, conn))
1600 return 0;
1601 if (pqGetInt(&msgLength, 4, conn))
1602 return 0;
1603 if (msgLength < 4)
1604 {
1605 handleSyncLoss(conn, id, msgLength);
1606 return -2;
1607 }
1608 avail = conn->inEnd - conn->inCursor;
1609 if (avail < msgLength - 4)
1610 {
1611 /*
1612 * Before returning, enlarge the input buffer if needed to hold
1613 * the whole message. See notes in parseInput.
1614 */
1615 if (pqCheckInBufferSpace(conn->inCursor + (size_t) msgLength - 4,
1616 conn))
1617 {
1618 /*
1619 * XXX add some better recovery code... plan is to skip over
1620 * the message using its length, then report an error. For the
1621 * moment, just treat this like loss of sync (which indeed it
1622 * might be!)
1623 */
1624 handleSyncLoss(conn, id, msgLength);
1625 return -2;
1626 }
1627 return 0;
1628 }
1629
1630 /*
1631 * If it's a legitimate async message type, process it. (NOTIFY
1632 * messages are not currently possible here, but we handle them for
1633 * completeness.) Otherwise, if it's anything except Copy Data,
1634 * report end-of-copy.
1635 */
1636 switch (id)
1637 {
1638 case 'A': /* NOTIFY */
1639 if (getNotify(conn))
1640 return 0;
1641 break;
1642 case 'N': /* NOTICE */
1643 if (pqGetErrorNotice3(conn, false))
1644 return 0;
1645 break;
1646 case 'S': /* ParameterStatus */
1647 if (getParameterStatus(conn))
1648 return 0;
1649 break;
1650 case 'd': /* Copy Data, pass it back to caller */
1651 return msgLength;
1652 case 'c':
1653
1654 /*
1655 * If this is a CopyDone message, exit COPY_OUT mode and let
1656 * caller read status with PQgetResult(). If we're in
1657 * COPY_BOTH mode, return to COPY_IN mode.
1658 */
1659 if (conn->asyncStatus == PGASYNC_COPY_BOTH)
1660 conn->asyncStatus = PGASYNC_COPY_IN;
1661 else
1662 conn->asyncStatus = PGASYNC_BUSY;
1663 return -1;
1664 default: /* treat as end of copy */
1665
1666 /*
1667 * Any other message terminates either COPY_IN or COPY_BOTH
1668 * mode.
1669 */
1670 conn->asyncStatus = PGASYNC_BUSY;
1671 return -1;
1672 }
1673
1674 /* trace server-to-client message */
1675 if (conn->Pfdebug)
1676 pqTraceOutputMessage(conn, conn->inBuffer + conn->inStart, false);
1677
1678 /* Drop the processed message and loop around for another */
1679 conn->inStart = conn->inCursor;
1680 }
1681 }
1682
1683 /*
1684 * PQgetCopyData - read a row of data from the backend during COPY OUT
1685 * or COPY BOTH
1686 *
1687 * If successful, sets *buffer to point to a malloc'd row of data, and
1688 * returns row length (always > 0) as result.
1689 * Returns 0 if no row available yet (only possible if async is true),
1690 * -1 if end of copy (consult PQgetResult), or -2 if error (consult
1691 * PQerrorMessage).
1692 */
1693 int
1694 pqGetCopyData3(PGconn *conn, char **buffer, int async)
1695 {
1696 int msgLength;
1697
1698 for (;;)
1699 {
1700 /*
1701 * Collect the next input message. To make life simpler for async
1702 * callers, we keep returning 0 until the next message is fully
1703 * available, even if it is not Copy Data.
1704 */
1705 msgLength = getCopyDataMessage(conn);
1706 if (msgLength < 0)
1707 return msgLength; /* end-of-copy or error */
1708 if (msgLength == 0)
1709 {
1710 /* Don't block if async read requested */
1711 if (async)
1712 return 0;
1713 /* Need to load more data */
1714 if (pqWait(true, false, conn) ||
1715 pqReadData(conn) < 0)
1716 return -2;
1717 continue;
1718 }
1719
1720 /*
1721 * Drop zero-length messages (shouldn't happen anyway). Otherwise
1722 * pass the data back to the caller.
1723 */
1724 msgLength -= 4;
1725 if (msgLength > 0)
1726 {
1727 *buffer = (char *) malloc(msgLength + 1);
1728 if (*buffer == NULL)
1729 {
1730 appendPQExpBufferStr(&conn->errorMessage,
1731 libpq_gettext("out of memory\n"));
1732 return -2;
1733 }
1734 memcpy(*buffer, &conn->inBuffer[conn->inCursor], msgLength);
1735 (*buffer)[msgLength] = '\0'; /* Add terminating null */
1736
1737 /* Mark message consumed */
1738 conn->inStart = conn->inCursor + msgLength;
1739
1740 return msgLength;
1741 }
1742
1743 /* Empty, so drop it and loop around for another */
1744 conn->inStart = conn->inCursor;
1745 }
1746 }
1747
1748 /*
1749 * PQgetline - gets a newline-terminated string from the backend.
1750 *
1751 * See fe-exec.c for documentation.
1752 */
1753 int
1754 pqGetline3(PGconn *conn, char *s, int maxlen)
1755 {
1756 int status;
1757
1758 if (conn->sock == PGINVALID_SOCKET ||
1759 (conn->asyncStatus != PGASYNC_COPY_OUT &&
1760 conn->asyncStatus != PGASYNC_COPY_BOTH) ||
1761 conn->copy_is_binary)
1762 {
1763 appendPQExpBufferStr(&conn->errorMessage,
1764 libpq_gettext("PQgetline: not doing text COPY OUT\n"));
1765 *s = '\0';
1766 return EOF;
1767 }
1768
1769 while ((status = PQgetlineAsync(conn, s, maxlen - 1)) == 0)
1770 {
1771 /* need to load more data */
1772 if (pqWait(true, false, conn) ||
1773 pqReadData(conn) < 0)
1774 {
1775 *s = '\0';
1776 return EOF;
1777 }
1778 }
1779
1780 if (status < 0)
1781 {
1782 /* End of copy detected; gin up old-style terminator */
1783 strcpy(s, "\\.");
1784 return 0;
1785 }
1786
1787 /* Add null terminator, and strip trailing \n if present */
1788 if (s[status - 1] == '\n')
1789 {
1790 s[status - 1] = '\0';
1791 return 0;
1792 }
1793 else
1794 {
1795 s[status] = '\0';
1796 return 1;
1797 }
1798 }
1799
1800 /*
1801 * PQgetlineAsync - gets a COPY data row without blocking.
1802 *
1803 * See fe-exec.c for documentation.
1804 */
1805 int
1806 pqGetlineAsync3(PGconn *conn, char *buffer, int bufsize)
1807 {
1808 int msgLength;
1809 int avail;
1810
1811 if (conn->asyncStatus != PGASYNC_COPY_OUT
1812 && conn->asyncStatus != PGASYNC_COPY_BOTH)
1813 return -1; /* we are not doing a copy... */
1814
1815 /*
1816 * Recognize the next input message. To make life simpler for async
1817 * callers, we keep returning 0 until the next message is fully available
1818 * even if it is not Copy Data. This should keep PQendcopy from blocking.
1819 * (Note: unlike pqGetCopyData3, we do not change asyncStatus here.)
1820 */
1821 msgLength = getCopyDataMessage(conn);
1822 if (msgLength < 0)
1823 return -1; /* end-of-copy or error */
1824 if (msgLength == 0)
1825 return 0; /* no data yet */
1826
1827 /*
1828 * Move data from libpq's buffer to the caller's. In the case where a
1829 * prior call found the caller's buffer too small, we use
1830 * conn->copy_already_done to remember how much of the row was already
1831 * returned to the caller.
1832 */
1833 conn->inCursor += conn->copy_already_done;
1834 avail = msgLength - 4 - conn->copy_already_done;
1835 if (avail <= bufsize)
1836 {
1837 /* Able to consume the whole message */
1838 memcpy(buffer, &conn->inBuffer[conn->inCursor], avail);
1839 /* Mark message consumed */
1840 conn->inStart = conn->inCursor + avail;
1841 /* Reset state for next time */
1842 conn->copy_already_done = 0;
1843 return avail;
1844 }
1845 else
1846 {
1847 /* We must return a partial message */
1848 memcpy(buffer, &conn->inBuffer[conn->inCursor], bufsize);
1849 /* The message is NOT consumed from libpq's buffer */
1850 conn->copy_already_done += bufsize;
1851 return bufsize;
1852 }
1853 }
1854
1855 /*
1856 * PQendcopy
1857 *
1858 * See fe-exec.c for documentation.
1859 */
1860 int
1861 pqEndcopy3(PGconn *conn)
1862 {
1863 PGresult *result;
1864
1865 if (conn->asyncStatus != PGASYNC_COPY_IN &&
1866 conn->asyncStatus != PGASYNC_COPY_OUT &&
1867 conn->asyncStatus != PGASYNC_COPY_BOTH)
1868 {
1869 appendPQExpBufferStr(&conn->errorMessage,
1870 libpq_gettext("no COPY in progress\n"));
1871 return 1;
1872 }
1873
1874 /* Send the CopyDone message if needed */
1875 if (conn->asyncStatus == PGASYNC_COPY_IN ||
1876 conn->asyncStatus == PGASYNC_COPY_BOTH)
1877 {
1878 if (pqPutMsgStart('c', conn) < 0 ||
1879 pqPutMsgEnd(conn) < 0)
1880 return 1;
1881
1882 /*
1883 * If we sent the COPY command in extended-query mode, we must issue a
1884 * Sync as well.
1885 */
1886 if (conn->cmd_queue_head &&
1887 conn->cmd_queue_head->queryclass != PGQUERY_SIMPLE)
1888 {
1889 if (pqPutMsgStart('S', conn) < 0 ||
1890 pqPutMsgEnd(conn) < 0)
1891 return 1;
1892 }
1893 }
1894
1895 /*
1896 * make sure no data is waiting to be sent, abort if we are non-blocking
1897 * and the flush fails
1898 */
1899 if (pqFlush(conn) && pqIsnonblocking(conn))
1900 return 1;
1901
1902 /* Return to active duty */
1903 conn->asyncStatus = PGASYNC_BUSY;
1904
1905 /*
1906 * Non blocking connections may have to abort at this point. If everyone
1907 * played the game there should be no problem, but in error scenarios the
1908 * expected messages may not have arrived yet. (We are assuming that the
1909 * backend's packetizing will ensure that CommandComplete arrives along
1910 * with the CopyDone; are there corner cases where that doesn't happen?)
1911 */
1912 if (pqIsnonblocking(conn) && PQisBusy(conn))
1913 return 1;
1914
1915 /* Wait for the completion response */
1916 result = PQgetResult(conn);
1917
1918 /* Expecting a successful result */
1919 if (result && result->resultStatus == PGRES_COMMAND_OK)
1920 {
1921 PQclear(result);
1922 return 0;
1923 }
1924
1925 /*
1926 * Trouble. For backwards-compatibility reasons, we issue the error
1927 * message as if it were a notice (would be nice to get rid of this
1928 * silliness, but too many apps probably don't handle errors from
1929 * PQendcopy reasonably). Note that the app can still obtain the error
1930 * status from the PGconn object.
1931 */
1932 if (conn->errorMessage.len > 0)
1933 {
1934 /* We have to strip the trailing newline ... pain in neck... */
1935 char svLast = conn->errorMessage.data[conn->errorMessage.len - 1];
1936
1937 if (svLast == '\n')
1938 conn->errorMessage.data[conn->errorMessage.len - 1] = '\0';
1939 pqInternalNotice(&conn->noticeHooks, "%s", conn->errorMessage.data);
1940 conn->errorMessage.data[conn->errorMessage.len - 1] = svLast;
1941 }
1942
1943 PQclear(result);
1944
1945 return 1;
1946 }
1947
1948
1949 /*
1950 * PQfn - Send a function call to the POSTGRES backend.
1951 *
1952 * See fe-exec.c for documentation.
1953 */
1954 PGresult *
1955 pqFunctionCall3(PGconn *conn, Oid fnid,
1956 int *result_buf, int *actual_result_len,
1957 int result_is_int,
1958 const PQArgBlock *args, int nargs)
1959 {
1960 bool needInput = false;
1961 ExecStatusType status = PGRES_FATAL_ERROR;
1962 char id;
1963 int msgLength;
1964 int avail;
1965 int i;
1966
1967 /* already validated by PQfn */
1968 Assert(conn->pipelineStatus == PQ_PIPELINE_OFF);
1969
1970 /* PQfn already validated connection state */
1971
1972 if (pqPutMsgStart('F', conn) < 0 || /* function call msg */
1973 pqPutInt(fnid, 4, conn) < 0 || /* function id */
1974 pqPutInt(1, 2, conn) < 0 || /* # of format codes */
1975 pqPutInt(1, 2, conn) < 0 || /* format code: BINARY */
1976 pqPutInt(nargs, 2, conn) < 0) /* # of args */
1977 {
1978 /* error message should be set up already */
1979 return NULL;
1980 }
1981
1982 for (i = 0; i < nargs; ++i)
1983 { /* len.int4 + contents */
1984 if (pqPutInt(args[i].len, 4, conn))
1985 return NULL;
1986 if (args[i].len == -1)
1987 continue; /* it's NULL */
1988
1989 if (args[i].isint)
1990 {
1991 if (pqPutInt(args[i].u.integer, args[i].len, conn))
1992 return NULL;
1993 }
1994 else
1995 {
1996 if (pqPutnchar((char *) args[i].u.ptr, args[i].len, conn))
1997 return NULL;
1998 }
1999 }
2000
2001 if (pqPutInt(1, 2, conn) < 0) /* result format code: BINARY */
2002 return NULL;
2003
2004 if (pqPutMsgEnd(conn) < 0 ||
2005 pqFlush(conn))
2006 return NULL;
2007
2008 for (;;)
2009 {
2010 if (needInput)
2011 {
2012 /* Wait for some data to arrive (or for the channel to close) */
2013 if (pqWait(true, false, conn) ||
2014 pqReadData(conn) < 0)
2015 break;
2016 }
2017
2018 /*
2019 * Scan the message. If we run out of data, loop around to try again.
2020 */
2021 needInput = true;
2022
2023 conn->inCursor = conn->inStart;
2024 if (pqGetc(&id, conn))
2025 continue;
2026 if (pqGetInt(&msgLength, 4, conn))
2027 continue;
2028
2029 /*
2030 * Try to validate message type/length here. A length less than 4 is
2031 * definitely broken. Large lengths should only be believed for a few
2032 * message types.
2033 */
2034 if (msgLength < 4)
2035 {
2036 handleSyncLoss(conn, id, msgLength);
2037 break;
2038 }
2039 if (msgLength > 30000 && !VALID_LONG_MESSAGE_TYPE(id))
2040 {
2041 handleSyncLoss(conn, id, msgLength);
2042 break;
2043 }
2044
2045 /*
2046 * Can't process if message body isn't all here yet.
2047 */
2048 msgLength -= 4;
2049 avail = conn->inEnd - conn->inCursor;
2050 if (avail < msgLength)
2051 {
2052 /*
2053 * Before looping, enlarge the input buffer if needed to hold the
2054 * whole message. See notes in parseInput.
2055 */
2056 if (pqCheckInBufferSpace(conn->inCursor + (size_t) msgLength,
2057 conn))
2058 {
2059 /*
2060 * XXX add some better recovery code... plan is to skip over
2061 * the message using its length, then report an error. For the
2062 * moment, just treat this like loss of sync (which indeed it
2063 * might be!)
2064 */
2065 handleSyncLoss(conn, id, msgLength);
2066 break;
2067 }
2068 continue;
2069 }
2070
2071 /*
2072 * We should see V or E response to the command, but might get N
2073 * and/or A notices first. We also need to swallow the final Z before
2074 * returning.
2075 */
2076 switch (id)
2077 {
2078 case 'V': /* function result */
2079 if (pqGetInt(actual_result_len, 4, conn))
2080 continue;
2081 if (*actual_result_len != -1)
2082 {
2083 if (result_is_int)
2084 {
2085 if (pqGetInt(result_buf, *actual_result_len, conn))
2086 continue;
2087 }
2088 else
2089 {
2090 if (pqGetnchar((char *) result_buf,
2091 *actual_result_len,
2092 conn))
2093 continue;
2094 }
2095 }
2096 /* correctly finished function result message */
2097 status = PGRES_COMMAND_OK;
2098 break;
2099 case 'E': /* error return */
2100 if (pqGetErrorNotice3(conn, true))
2101 continue;
2102 status = PGRES_FATAL_ERROR;
2103 break;
2104 case 'A': /* notify message */
2105 /* handle notify and go back to processing return values */
2106 if (getNotify(conn))
2107 continue;
2108 break;
2109 case 'N': /* notice */
2110 /* handle notice and go back to processing return values */
2111 if (pqGetErrorNotice3(conn, false))
2112 continue;
2113 break;
2114 case 'Z': /* backend is ready for new query */
2115 if (getReadyForQuery(conn))
2116 continue;
2117 /* consume the message and exit */
2118 conn->inStart += 5 + msgLength;
2119 /* if we saved a result object (probably an error), use it */
2120 if (conn->result)
2121 return pqPrepareAsyncResult(conn);
2122 return PQmakeEmptyPGresult(conn, status);
2123 case 'S': /* parameter status */
2124 if (getParameterStatus(conn))
2125 continue;
2126 break;
2127 default:
2128 /* The backend violates the protocol. */
2129 appendPQExpBuffer(&conn->errorMessage,
2130 libpq_gettext("protocol error: id=0x%x\n"),
2131 id);
2132 pqSaveErrorResult(conn);
2133 /* trust the specified message length as what to skip */
2134 conn->inStart += 5 + msgLength;
2135 return pqPrepareAsyncResult(conn);
2136 }
2137
2138 /* trace server-to-client message */
2139 if (conn->Pfdebug)
2140 pqTraceOutputMessage(conn, conn->inBuffer + conn->inStart, false);
2141
2142 /* Completed this message, keep going */
2143 /* trust the specified message length as what to skip */
2144 conn->inStart += 5 + msgLength;
2145 needInput = false;
2146 }
2147
2148 /*
2149 * We fall out of the loop only upon failing to read data.
2150 * conn->errorMessage has been set by pqWait or pqReadData. We want to
2151 * append it to any already-received error message.
2152 */
2153 pqSaveErrorResult(conn);
2154 return pqPrepareAsyncResult(conn);
2155 }
2156
2157
2158 /*
2159 * Construct startup packet
2160 *
2161 * Returns a malloc'd packet buffer, or NULL if out of memory
2162 */
2163 char *
2164 pqBuildStartupPacket3(PGconn *conn, int *packetlen,
2165 const PQEnvironmentOption *options)
2166 {
2167 char *startpacket;
2168
2169 *packetlen = build_startup_packet(conn, NULL, options);
2170 startpacket = (char *) malloc(*packetlen);
2171 if (!startpacket)
2172 return NULL;
2173 *packetlen = build_startup_packet(conn, startpacket, options);
2174 return startpacket;
2175 }
2176
2177 /*
2178 * Build a startup packet given a filled-in PGconn structure.
2179 *
2180 * We need to figure out how much space is needed, then fill it in.
2181 * To avoid duplicate logic, this routine is called twice: the first time
2182 * (with packet == NULL) just counts the space needed, the second time
2183 * (with packet == allocated space) fills it in. Return value is the number
2184 * of bytes used.
2185 */
2186 static int
2187 build_startup_packet(const PGconn *conn, char *packet,
2188 const PQEnvironmentOption *options)
2189 {
2190 int packet_len = 0;
2191 const PQEnvironmentOption *next_eo;
2192 const char *val;
2193
2194 /* Protocol version comes first. */
2195 if (packet)
2196 {
2197 ProtocolVersion pv = pg_hton32(conn->pversion);
2198
2199 memcpy(packet + packet_len, &pv, sizeof(ProtocolVersion));
2200 }
2201 packet_len += sizeof(ProtocolVersion);
2202
2203 /* Add user name, database name, options */
2204
2205 #define ADD_STARTUP_OPTION(optname, optval) \
2206 do { \
2207 if (packet) \
2208 strcpy(packet + packet_len, optname); \
2209 packet_len += strlen(optname) + 1; \
2210 if (packet) \
2211 strcpy(packet + packet_len, optval); \
2212 packet_len += strlen(optval) + 1; \
2213 } while(0)
2214
2215 if (conn->pguser && conn->pguser[0])
2216 ADD_STARTUP_OPTION("user", conn->pguser);
2217 if (conn->dbName && conn->dbName[0])
2218 ADD_STARTUP_OPTION("database", conn->dbName);
2219 if (conn->replication && conn->replication[0])
2220 ADD_STARTUP_OPTION("replication", conn->replication);
2221 if (conn->pgoptions && conn->pgoptions[0])
2222 ADD_STARTUP_OPTION("options", conn->pgoptions);
2223 if (conn->send_appname)
2224 {
2225 /* Use appname if present, otherwise use fallback */
2226 val = conn->appname ? conn->appname : conn->fbappname;
2227 if (val && val[0])
2228 ADD_STARTUP_OPTION("application_name", val);
2229 }
2230
2231 if (conn->client_encoding_initial && conn->client_encoding_initial[0])
2232 ADD_STARTUP_OPTION("client_encoding", conn->client_encoding_initial);
2233
2234 /* Add any environment-driven GUC settings needed */
2235 for (next_eo = options; next_eo->envName; next_eo++)
2236 {
2237 if ((val = getenv(next_eo->envName)) != NULL)
2238 {
2239 if (pg_strcasecmp(val, "default") != 0)
2240 ADD_STARTUP_OPTION(next_eo->pgName, val);
2241 }
2242 }
2243
2244 /* Add trailing terminator */
2245 if (packet)
2246 packet[packet_len] = '\0';
2247 packet_len++;
2248
2249 return packet_len;
2250 }
Postgresql Clone from git://git.postgresql.org/git/postgresql.git