Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * fe-protocol2.c
4 : * functions that are specific to frontend/backend protocol version 2
5 : *
6 : * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/interfaces/libpq/fe-protocol2.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 : #include "postgres_fe.h"
16 :
17 : #include <ctype.h>
18 : #include <fcntl.h>
19 :
20 : #include "libpq-fe.h"
21 : #include "libpq-int.h"
22 :
23 :
24 : #ifdef WIN32
25 : #include "win32.h"
26 : #else
27 : #include <unistd.h>
28 : #include <netinet/in.h>
29 : #ifdef HAVE_NETINET_TCP_H
30 : #include <netinet/tcp.h>
31 : #endif
32 : #include <arpa/inet.h>
33 : #endif
34 :
35 :
36 : static int getRowDescriptions(PGconn *conn);
37 : static int getAnotherTuple(PGconn *conn, bool binary);
38 : static int pqGetErrorNotice2(PGconn *conn, bool isError);
39 : static void checkXactStatus(PGconn *conn, const char *cmdTag);
40 : static int getNotify(PGconn *conn);
41 :
42 :
43 : /*
44 : * pqSetenvPoll
45 : *
46 : * Polls the process of passing the values of a standard set of environment
47 : * variables to the backend.
48 : */
49 : PostgresPollingStatusType
50 0 : pqSetenvPoll(PGconn *conn)
51 : {
52 : PGresult *res;
53 :
54 0 : if (conn == NULL || conn->status == CONNECTION_BAD)
55 0 : return PGRES_POLLING_FAILED;
56 :
57 : /* Check whether there are any data for us */
58 0 : switch (conn->setenv_state)
59 : {
60 : /* These are reading states */
61 : case SETENV_STATE_CLIENT_ENCODING_WAIT:
62 : case SETENV_STATE_OPTION_WAIT:
63 : case SETENV_STATE_QUERY1_WAIT:
64 : case SETENV_STATE_QUERY2_WAIT:
65 : {
66 : /* Load waiting data */
67 0 : int n = pqReadData(conn);
68 :
69 0 : if (n < 0)
70 0 : goto error_return;
71 0 : if (n == 0)
72 0 : return PGRES_POLLING_READING;
73 :
74 0 : break;
75 : }
76 :
77 : /* These are writing states, so we just proceed. */
78 : case SETENV_STATE_CLIENT_ENCODING_SEND:
79 : case SETENV_STATE_OPTION_SEND:
80 : case SETENV_STATE_QUERY1_SEND:
81 : case SETENV_STATE_QUERY2_SEND:
82 0 : break;
83 :
84 : /* Should we raise an error if called when not active? */
85 : case SETENV_STATE_IDLE:
86 0 : return PGRES_POLLING_OK;
87 :
88 : default:
89 0 : printfPQExpBuffer(&conn->errorMessage,
90 : libpq_gettext(
91 : "invalid setenv state %c, "
92 : "probably indicative of memory corruption\n"
93 : ),
94 0 : conn->setenv_state);
95 0 : goto error_return;
96 : }
97 :
98 : /* We will loop here until there is nothing left to do in this call. */
99 : for (;;)
100 : {
101 0 : switch (conn->setenv_state)
102 : {
103 : /*
104 : * The _CLIENT_ENCODING_SEND code is slightly different from
105 : * _OPTION_SEND below (e.g., no getenv() call), which is why a
106 : * different state is used.
107 : */
108 : case SETENV_STATE_CLIENT_ENCODING_SEND:
109 : {
110 : char setQuery[100]; /* note length limit in
111 : * sprintf below */
112 0 : const char *val = conn->client_encoding_initial;
113 :
114 0 : if (val)
115 : {
116 0 : if (pg_strcasecmp(val, "default") == 0)
117 0 : sprintf(setQuery, "SET client_encoding = DEFAULT");
118 : else
119 0 : sprintf(setQuery, "SET client_encoding = '%.60s'",
120 : val);
121 : #ifdef CONNECTDEBUG
122 : fprintf(stderr,
123 : "Sending client_encoding with %s\n",
124 : setQuery);
125 : #endif
126 0 : if (!PQsendQuery(conn, setQuery))
127 0 : goto error_return;
128 :
129 0 : conn->setenv_state = SETENV_STATE_CLIENT_ENCODING_WAIT;
130 : }
131 : else
132 0 : conn->setenv_state = SETENV_STATE_OPTION_SEND;
133 0 : break;
134 : }
135 :
136 : case SETENV_STATE_OPTION_SEND:
137 : {
138 : /*
139 : * Send SET commands for stuff directed by Environment
140 : * Options. Note: we assume that SET commands won't start
141 : * transaction blocks, even in a 7.3 server with
142 : * autocommit off.
143 : */
144 : char setQuery[100]; /* note length limit in
145 : * sprintf below */
146 :
147 0 : if (conn->next_eo->envName)
148 : {
149 : const char *val;
150 :
151 0 : if ((val = getenv(conn->next_eo->envName)))
152 : {
153 0 : if (pg_strcasecmp(val, "default") == 0)
154 0 : sprintf(setQuery, "SET %s = DEFAULT",
155 0 : conn->next_eo->pgName);
156 : else
157 0 : sprintf(setQuery, "SET %s = '%.60s'",
158 0 : conn->next_eo->pgName, val);
159 : #ifdef CONNECTDEBUG
160 : fprintf(stderr,
161 : "Use environment variable %s to send %s\n",
162 : conn->next_eo->envName, setQuery);
163 : #endif
164 0 : if (!PQsendQuery(conn, setQuery))
165 0 : goto error_return;
166 :
167 0 : conn->setenv_state = SETENV_STATE_OPTION_WAIT;
168 : }
169 : else
170 0 : conn->next_eo++;
171 : }
172 : else
173 : {
174 : /* No more options to send, so move on to querying */
175 0 : conn->setenv_state = SETENV_STATE_QUERY1_SEND;
176 : }
177 0 : break;
178 : }
179 :
180 : case SETENV_STATE_CLIENT_ENCODING_WAIT:
181 : {
182 0 : if (PQisBusy(conn))
183 0 : return PGRES_POLLING_READING;
184 :
185 0 : res = PQgetResult(conn);
186 :
187 0 : if (res)
188 : {
189 0 : if (PQresultStatus(res) != PGRES_COMMAND_OK)
190 : {
191 0 : PQclear(res);
192 0 : goto error_return;
193 : }
194 0 : PQclear(res);
195 : /* Keep reading until PQgetResult returns NULL */
196 : }
197 : else
198 : {
199 : /* Query finished, so send the next option */
200 0 : conn->setenv_state = SETENV_STATE_OPTION_SEND;
201 : }
202 0 : break;
203 : }
204 :
205 : case SETENV_STATE_OPTION_WAIT:
206 : {
207 0 : if (PQisBusy(conn))
208 0 : return PGRES_POLLING_READING;
209 :
210 0 : res = PQgetResult(conn);
211 :
212 0 : if (res)
213 : {
214 0 : if (PQresultStatus(res) != PGRES_COMMAND_OK)
215 : {
216 0 : PQclear(res);
217 0 : goto error_return;
218 : }
219 0 : PQclear(res);
220 : /* Keep reading until PQgetResult returns NULL */
221 : }
222 : else
223 : {
224 : /* Query finished, so send the next option */
225 0 : conn->next_eo++;
226 0 : conn->setenv_state = SETENV_STATE_OPTION_SEND;
227 : }
228 0 : break;
229 : }
230 :
231 : case SETENV_STATE_QUERY1_SEND:
232 : {
233 : /*
234 : * Issue query to get information we need. Here we must
235 : * use begin/commit in case autocommit is off by default
236 : * in a 7.3 server.
237 : *
238 : * Note: version() exists in all protocol-2.0-supporting
239 : * backends. In 7.3 it would be safer to write
240 : * pg_catalog.version(), but we can't do that without
241 : * causing problems on older versions.
242 : */
243 0 : if (!PQsendQuery(conn, "begin; select version(); end"))
244 0 : goto error_return;
245 :
246 0 : conn->setenv_state = SETENV_STATE_QUERY1_WAIT;
247 0 : return PGRES_POLLING_READING;
248 : }
249 :
250 : case SETENV_STATE_QUERY1_WAIT:
251 : {
252 0 : if (PQisBusy(conn))
253 0 : return PGRES_POLLING_READING;
254 :
255 0 : res = PQgetResult(conn);
256 :
257 0 : if (res)
258 : {
259 : char *val;
260 :
261 0 : if (PQresultStatus(res) == PGRES_COMMAND_OK)
262 : {
263 : /* ignore begin/commit command results */
264 0 : PQclear(res);
265 0 : continue;
266 : }
267 :
268 0 : if (PQresultStatus(res) != PGRES_TUPLES_OK ||
269 0 : PQntuples(res) != 1)
270 : {
271 0 : PQclear(res);
272 0 : goto error_return;
273 : }
274 :
275 : /*
276 : * Extract server version and save as if
277 : * ParameterStatus
278 : */
279 0 : val = PQgetvalue(res, 0, 0);
280 0 : if (val && strncmp(val, "PostgreSQL ", 11) == 0)
281 : {
282 : char *ptr;
283 :
284 : /* strip off PostgreSQL part */
285 0 : val += 11;
286 :
287 : /*
288 : * strip off platform part (scribbles on result,
289 : * naughty naughty)
290 : */
291 0 : ptr = strchr(val, ' ');
292 0 : if (ptr)
293 0 : *ptr = '\0';
294 :
295 0 : pqSaveParameterStatus(conn, "server_version",
296 : val);
297 : }
298 :
299 0 : PQclear(res);
300 : /* Keep reading until PQgetResult returns NULL */
301 : }
302 : else
303 : {
304 : /* Query finished, move to next */
305 0 : conn->setenv_state = SETENV_STATE_QUERY2_SEND;
306 : }
307 0 : break;
308 : }
309 :
310 : case SETENV_STATE_QUERY2_SEND:
311 : {
312 : const char *query;
313 :
314 : /*
315 : * pg_client_encoding does not exist in pre-7.2 servers.
316 : * So we need to be prepared for an error here. Do *not*
317 : * start a transaction block, except in 7.3 servers where
318 : * we need to prevent autocommit-off from starting a
319 : * transaction anyway.
320 : */
321 0 : if (conn->sversion >= 70300 &&
322 0 : conn->sversion < 70400)
323 0 : query = "begin; select pg_catalog.pg_client_encoding(); end";
324 : else
325 0 : query = "select pg_client_encoding()";
326 0 : if (!PQsendQuery(conn, query))
327 0 : goto error_return;
328 :
329 0 : conn->setenv_state = SETENV_STATE_QUERY2_WAIT;
330 0 : return PGRES_POLLING_READING;
331 : }
332 :
333 : case SETENV_STATE_QUERY2_WAIT:
334 : {
335 0 : if (PQisBusy(conn))
336 0 : return PGRES_POLLING_READING;
337 :
338 0 : res = PQgetResult(conn);
339 :
340 0 : if (res)
341 : {
342 : const char *val;
343 :
344 0 : if (PQresultStatus(res) == PGRES_COMMAND_OK)
345 : {
346 : /* ignore begin/commit command results */
347 0 : PQclear(res);
348 0 : continue;
349 : }
350 :
351 0 : if (PQresultStatus(res) == PGRES_TUPLES_OK &&
352 0 : PQntuples(res) == 1)
353 : {
354 : /* Extract client encoding and save it */
355 0 : val = PQgetvalue(res, 0, 0);
356 0 : if (val && *val) /* null should not happen, but */
357 0 : pqSaveParameterStatus(conn, "client_encoding",
358 : val);
359 : }
360 : else
361 : {
362 : /*
363 : * Error: presumably function not available, so
364 : * use PGCLIENTENCODING or SQL_ASCII as the
365 : * fallback.
366 : */
367 0 : val = getenv("PGCLIENTENCODING");
368 0 : if (val && *val)
369 0 : pqSaveParameterStatus(conn, "client_encoding",
370 : val);
371 : else
372 0 : pqSaveParameterStatus(conn, "client_encoding",
373 : "SQL_ASCII");
374 : }
375 :
376 0 : PQclear(res);
377 : /* Keep reading until PQgetResult returns NULL */
378 : }
379 : else
380 : {
381 : /* Query finished, so we're done */
382 0 : conn->setenv_state = SETENV_STATE_IDLE;
383 0 : return PGRES_POLLING_OK;
384 : }
385 0 : break;
386 : }
387 :
388 : default:
389 0 : printfPQExpBuffer(&conn->errorMessage,
390 : libpq_gettext("invalid state %c, "
391 : "probably indicative of memory corruption\n"),
392 0 : conn->setenv_state);
393 0 : goto error_return;
394 : }
395 0 : }
396 :
397 : /* Unreachable */
398 :
399 : error_return:
400 0 : conn->setenv_state = SETENV_STATE_IDLE;
401 0 : return PGRES_POLLING_FAILED;
402 : }
403 :
404 :
405 : /*
406 : * parseInput: if appropriate, parse input data from backend
407 : * until input is exhausted or a stopping state is reached.
408 : * Note that this function will NOT attempt to read more data from the backend.
409 : */
410 : void
411 0 : pqParseInput2(PGconn *conn)
412 : {
413 : char id;
414 :
415 : /*
416 : * Loop to parse successive complete messages available in the buffer.
417 : */
418 : for (;;)
419 : {
420 : /*
421 : * Quit if in COPY_OUT state: we expect raw data from the server until
422 : * PQendcopy is called. Don't try to parse it according to the normal
423 : * protocol. (This is bogus. The data lines ought to be part of the
424 : * protocol and have identifying leading characters.)
425 : */
426 0 : if (conn->asyncStatus == PGASYNC_COPY_OUT)
427 0 : return;
428 :
429 : /*
430 : * OK to try to read a message type code.
431 : */
432 0 : conn->inCursor = conn->inStart;
433 0 : if (pqGetc(&id, conn))
434 0 : return;
435 :
436 : /*
437 : * NOTIFY and NOTICE messages can happen in any state besides COPY
438 : * OUT; always process them right away.
439 : *
440 : * Most other messages should only be processed while in BUSY state.
441 : * (In particular, in READY state we hold off further parsing until
442 : * the application collects the current PGresult.)
443 : *
444 : * However, if the state is IDLE then we got trouble; we need to deal
445 : * with the unexpected message somehow.
446 : */
447 0 : if (id == 'A')
448 : {
449 0 : if (getNotify(conn))
450 0 : return;
451 : }
452 0 : else if (id == 'N')
453 : {
454 0 : if (pqGetErrorNotice2(conn, false))
455 0 : return;
456 : }
457 0 : else if (conn->asyncStatus != PGASYNC_BUSY)
458 : {
459 : /* If not IDLE state, just wait ... */
460 0 : if (conn->asyncStatus != PGASYNC_IDLE)
461 0 : return;
462 :
463 : /*
464 : * Unexpected message in IDLE state; need to recover somehow.
465 : * ERROR messages are displayed using the notice processor;
466 : * anything else is just dropped on the floor after displaying a
467 : * suitable warning notice. (An ERROR is very possibly the
468 : * backend telling us why it is about to close the connection, so
469 : * we don't want to just discard it...)
470 : */
471 0 : if (id == 'E')
472 : {
473 0 : if (pqGetErrorNotice2(conn, false /* treat as notice */ ))
474 0 : return;
475 : }
476 : else
477 : {
478 0 : pqInternalNotice(&conn->noticeHooks,
479 : "message type 0x%02x arrived from server while idle",
480 : id);
481 : /* Discard the unexpected message; good idea?? */
482 0 : conn->inStart = conn->inEnd;
483 0 : break;
484 : }
485 : }
486 : else
487 : {
488 : /*
489 : * In BUSY state, we can process everything.
490 : */
491 0 : switch (id)
492 : {
493 : case 'C': /* command complete */
494 0 : if (pqGets(&conn->workBuffer, conn))
495 0 : return;
496 0 : if (conn->result == NULL)
497 : {
498 0 : conn->result = PQmakeEmptyPGresult(conn,
499 : PGRES_COMMAND_OK);
500 0 : if (!conn->result)
501 : {
502 0 : printfPQExpBuffer(&conn->errorMessage,
503 : libpq_gettext("out of memory"));
504 0 : pqSaveErrorResult(conn);
505 : }
506 : }
507 0 : if (conn->result)
508 : {
509 0 : strlcpy(conn->result->cmdStatus, conn->workBuffer.data,
510 : CMDSTATUS_LEN);
511 : }
512 0 : checkXactStatus(conn, conn->workBuffer.data);
513 0 : conn->asyncStatus = PGASYNC_READY;
514 0 : break;
515 : case 'E': /* error return */
516 0 : if (pqGetErrorNotice2(conn, true))
517 0 : return;
518 0 : conn->asyncStatus = PGASYNC_READY;
519 0 : break;
520 : case 'Z': /* backend is ready for new query */
521 0 : conn->asyncStatus = PGASYNC_IDLE;
522 0 : break;
523 : case 'I': /* empty query */
524 : /* read and throw away the closing '\0' */
525 0 : if (pqGetc(&id, conn))
526 0 : return;
527 0 : if (id != '\0')
528 0 : pqInternalNotice(&conn->noticeHooks,
529 : "unexpected character %c following empty query response (\"I\" message)",
530 : id);
531 0 : if (conn->result == NULL)
532 : {
533 0 : conn->result = PQmakeEmptyPGresult(conn,
534 : PGRES_EMPTY_QUERY);
535 0 : if (!conn->result)
536 : {
537 0 : printfPQExpBuffer(&conn->errorMessage,
538 : libpq_gettext("out of memory"));
539 0 : pqSaveErrorResult(conn);
540 : }
541 : }
542 0 : conn->asyncStatus = PGASYNC_READY;
543 0 : break;
544 : case 'K': /* secret key data from the backend */
545 :
546 : /*
547 : * This is expected only during backend startup, but it's
548 : * just as easy to handle it as part of the main loop.
549 : * Save the data and continue processing.
550 : */
551 0 : if (pqGetInt(&(conn->be_pid), 4, conn))
552 0 : return;
553 0 : if (pqGetInt(&(conn->be_key), 4, conn))
554 0 : return;
555 0 : break;
556 : case 'P': /* synchronous (normal) portal */
557 0 : if (pqGets(&conn->workBuffer, conn))
558 0 : return;
559 : /* We pretty much ignore this message type... */
560 0 : break;
561 : case 'T': /* row descriptions (start of query results) */
562 0 : if (conn->result == NULL)
563 : {
564 : /* First 'T' in a query sequence */
565 0 : if (getRowDescriptions(conn))
566 0 : return;
567 : /* getRowDescriptions() moves inStart itself */
568 0 : continue;
569 : }
570 : else
571 : {
572 : /*
573 : * A new 'T' message is treated as the start of
574 : * another PGresult. (It is not clear that this is
575 : * really possible with the current backend.) We stop
576 : * parsing until the application accepts the current
577 : * result.
578 : */
579 0 : conn->asyncStatus = PGASYNC_READY;
580 0 : return;
581 : }
582 : break;
583 : case 'D': /* ASCII data tuple */
584 0 : if (conn->result != NULL)
585 : {
586 : /* Read another tuple of a normal query response */
587 0 : if (getAnotherTuple(conn, FALSE))
588 0 : return;
589 : /* getAnotherTuple() moves inStart itself */
590 0 : continue;
591 : }
592 : else
593 : {
594 0 : pqInternalNotice(&conn->noticeHooks,
595 : "server sent data (\"D\" message) without prior row description (\"T\" message)");
596 : /* Discard the unexpected message; good idea?? */
597 0 : conn->inStart = conn->inEnd;
598 0 : return;
599 : }
600 : break;
601 : case 'B': /* Binary data tuple */
602 0 : if (conn->result != NULL)
603 : {
604 : /* Read another tuple of a normal query response */
605 0 : if (getAnotherTuple(conn, TRUE))
606 0 : return;
607 : /* getAnotherTuple() moves inStart itself */
608 0 : continue;
609 : }
610 : else
611 : {
612 0 : pqInternalNotice(&conn->noticeHooks,
613 : "server sent binary data (\"B\" message) without prior row description (\"T\" message)");
614 : /* Discard the unexpected message; good idea?? */
615 0 : conn->inStart = conn->inEnd;
616 0 : return;
617 : }
618 : break;
619 : case 'G': /* Start Copy In */
620 0 : conn->asyncStatus = PGASYNC_COPY_IN;
621 0 : break;
622 : case 'H': /* Start Copy Out */
623 0 : conn->asyncStatus = PGASYNC_COPY_OUT;
624 0 : break;
625 :
626 : /*
627 : * Don't need to process CopyBothResponse here because it
628 : * never arrives from the server during protocol 2.0.
629 : */
630 : default:
631 0 : printfPQExpBuffer(&conn->errorMessage,
632 : libpq_gettext(
633 : "unexpected response from server; first received character was \"%c\"\n"),
634 : id);
635 : /* build an error result holding the error message */
636 0 : pqSaveErrorResult(conn);
637 : /* Discard the unexpected message; good idea?? */
638 0 : conn->inStart = conn->inEnd;
639 0 : conn->asyncStatus = PGASYNC_READY;
640 0 : return;
641 : } /* switch on protocol character */
642 : }
643 : /* Successfully consumed this message */
644 0 : conn->inStart = conn->inCursor;
645 0 : }
646 : }
647 :
648 : /*
649 : * parseInput subroutine to read a 'T' (row descriptions) message.
650 : * We build a PGresult structure containing the attribute data.
651 : * Returns: 0 if completed message, EOF if error or not enough data
652 : * received yet.
653 : *
654 : * Note that if we run out of data, we have to suspend and reprocess
655 : * the message after more data is received. Otherwise, conn->inStart
656 : * must get advanced past the processed data.
657 : */
658 : static int
659 0 : getRowDescriptions(PGconn *conn)
660 : {
661 : PGresult *result;
662 : int nfields;
663 : const char *errmsg;
664 : int i;
665 :
666 0 : result = PQmakeEmptyPGresult(conn, PGRES_TUPLES_OK);
667 0 : if (!result)
668 : {
669 0 : errmsg = NULL; /* means "out of memory", see below */
670 0 : goto advance_and_error;
671 : }
672 :
673 : /* parseInput already read the 'T' label. */
674 : /* the next two bytes are the number of fields */
675 0 : if (pqGetInt(&(result->numAttributes), 2, conn))
676 0 : goto EOFexit;
677 0 : nfields = result->numAttributes;
678 :
679 : /* allocate space for the attribute descriptors */
680 0 : if (nfields > 0)
681 : {
682 0 : result->attDescs = (PGresAttDesc *)
683 0 : pqResultAlloc(result, nfields * sizeof(PGresAttDesc), TRUE);
684 0 : if (!result->attDescs)
685 : {
686 0 : errmsg = NULL; /* means "out of memory", see below */
687 0 : goto advance_and_error;
688 : }
689 0 : MemSet(result->attDescs, 0, nfields * sizeof(PGresAttDesc));
690 : }
691 :
692 : /* get type info */
693 0 : for (i = 0; i < nfields; i++)
694 : {
695 : int typid;
696 : int typlen;
697 : int atttypmod;
698 :
699 0 : if (pqGets(&conn->workBuffer, conn) ||
700 0 : pqGetInt(&typid, 4, conn) ||
701 0 : pqGetInt(&typlen, 2, conn) ||
702 0 : pqGetInt(&atttypmod, 4, conn))
703 : goto EOFexit;
704 :
705 : /*
706 : * Since pqGetInt treats 2-byte integers as unsigned, we need to
707 : * coerce the result to signed form.
708 : */
709 0 : typlen = (int) ((int16) typlen);
710 :
711 0 : result->attDescs[i].name = pqResultStrdup(result,
712 0 : conn->workBuffer.data);
713 0 : if (!result->attDescs[i].name)
714 : {
715 0 : errmsg = NULL; /* means "out of memory", see below */
716 0 : goto advance_and_error;
717 : }
718 0 : result->attDescs[i].tableid = 0;
719 0 : result->attDescs[i].columnid = 0;
720 0 : result->attDescs[i].format = 0;
721 0 : result->attDescs[i].typid = typid;
722 0 : result->attDescs[i].typlen = typlen;
723 0 : result->attDescs[i].atttypmod = atttypmod;
724 : }
725 :
726 : /* Success! */
727 0 : conn->result = result;
728 :
729 : /* Advance inStart to show that the "T" message has been processed. */
730 0 : conn->inStart = conn->inCursor;
731 :
732 : /*
733 : * We could perform additional setup for the new result set here, but for
734 : * now there's nothing else to do.
735 : */
736 :
737 : /* And we're done. */
738 0 : return 0;
739 :
740 : advance_and_error:
741 :
742 : /*
743 : * Discard the failed message. Unfortunately we don't know for sure where
744 : * the end is, so just throw away everything in the input buffer. This is
745 : * not very desirable but it's the best we can do in protocol v2.
746 : */
747 0 : conn->inStart = conn->inEnd;
748 :
749 : /*
750 : * Replace partially constructed result with an error result. First
751 : * discard the old result to try to win back some memory.
752 : */
753 0 : pqClearAsyncResult(conn);
754 :
755 : /*
756 : * If preceding code didn't provide an error message, assume "out of
757 : * memory" was meant. The advantage of having this special case is that
758 : * freeing the old result first greatly improves the odds that gettext()
759 : * will succeed in providing a translation.
760 : */
761 0 : if (!errmsg)
762 0 : errmsg = libpq_gettext("out of memory for query result");
763 :
764 0 : printfPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
765 :
766 : /*
767 : * XXX: if PQmakeEmptyPGresult() fails, there's probably not much we can
768 : * do to recover...
769 : */
770 0 : conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
771 0 : conn->asyncStatus = PGASYNC_READY;
772 :
773 : EOFexit:
774 0 : if (result && result != conn->result)
775 0 : PQclear(result);
776 0 : return EOF;
777 : }
778 :
779 : /*
780 : * parseInput subroutine to read a 'B' or 'D' (row data) message.
781 : * We fill rowbuf with column pointers and then call the row processor.
782 : * Returns: 0 if completed message, EOF if error or not enough data
783 : * received yet.
784 : *
785 : * Note that if we run out of data, we have to suspend and reprocess
786 : * the message after more data is received. Otherwise, conn->inStart
787 : * must get advanced past the processed data.
788 : */
789 : static int
790 0 : getAnotherTuple(PGconn *conn, bool binary)
791 : {
792 0 : PGresult *result = conn->result;
793 0 : int nfields = result->numAttributes;
794 : const char *errmsg;
795 : PGdataValue *rowbuf;
796 :
797 : /* the backend sends us a bitmap of which attributes are null */
798 : char std_bitmap[64]; /* used unless it doesn't fit */
799 0 : char *bitmap = std_bitmap;
800 : int i;
801 : size_t nbytes; /* the number of bytes in bitmap */
802 : char bmap; /* One byte of the bitmap */
803 : int bitmap_index; /* Its index */
804 : int bitcnt; /* number of bits examined in current byte */
805 : int vlen; /* length of the current field value */
806 :
807 : /* Resize row buffer if needed */
808 0 : rowbuf = conn->rowBuf;
809 0 : if (nfields > conn->rowBufLen)
810 : {
811 0 : rowbuf = (PGdataValue *) realloc(rowbuf,
812 : nfields * sizeof(PGdataValue));
813 0 : if (!rowbuf)
814 : {
815 0 : errmsg = NULL; /* means "out of memory", see below */
816 0 : goto advance_and_error;
817 : }
818 0 : conn->rowBuf = rowbuf;
819 0 : conn->rowBufLen = nfields;
820 : }
821 :
822 : /* Save format specifier */
823 0 : result->binary = binary;
824 :
825 : /*
826 : * If it's binary, fix the column format indicators. We assume the
827 : * backend will consistently send either B or D, not a mix.
828 : */
829 0 : if (binary)
830 : {
831 0 : for (i = 0; i < nfields; i++)
832 0 : result->attDescs[i].format = 1;
833 : }
834 :
835 : /* Get the null-value bitmap */
836 0 : nbytes = (nfields + BITS_PER_BYTE - 1) / BITS_PER_BYTE;
837 : /* malloc() only for unusually large field counts... */
838 0 : if (nbytes > sizeof(std_bitmap))
839 : {
840 0 : bitmap = (char *) malloc(nbytes);
841 0 : if (!bitmap)
842 : {
843 0 : errmsg = NULL; /* means "out of memory", see below */
844 0 : goto advance_and_error;
845 : }
846 : }
847 :
848 0 : if (pqGetnchar(bitmap, nbytes, conn))
849 0 : goto EOFexit;
850 :
851 : /* Scan the fields */
852 0 : bitmap_index = 0;
853 0 : bmap = bitmap[bitmap_index];
854 0 : bitcnt = 0;
855 :
856 0 : for (i = 0; i < nfields; i++)
857 : {
858 : /* get the value length */
859 0 : if (!(bmap & 0200))
860 0 : vlen = NULL_LEN;
861 0 : else if (pqGetInt(&vlen, 4, conn))
862 0 : goto EOFexit;
863 : else
864 : {
865 0 : if (!binary)
866 0 : vlen = vlen - 4;
867 0 : if (vlen < 0)
868 0 : vlen = 0;
869 : }
870 0 : rowbuf[i].len = vlen;
871 :
872 : /*
873 : * rowbuf[i].value always points to the next address in the data
874 : * buffer even if the value is NULL. This allows row processors to
875 : * estimate data sizes more easily.
876 : */
877 0 : rowbuf[i].value = conn->inBuffer + conn->inCursor;
878 :
879 : /* Skip over the data value */
880 0 : if (vlen > 0)
881 : {
882 0 : if (pqSkipnchar(vlen, conn))
883 0 : goto EOFexit;
884 : }
885 :
886 : /* advance the bitmap stuff */
887 0 : bitcnt++;
888 0 : if (bitcnt == BITS_PER_BYTE)
889 : {
890 0 : bitmap_index++;
891 0 : bmap = bitmap[bitmap_index];
892 0 : bitcnt = 0;
893 : }
894 : else
895 0 : bmap <<= 1;
896 : }
897 :
898 : /* Release bitmap now if we allocated it */
899 0 : if (bitmap != std_bitmap)
900 0 : free(bitmap);
901 0 : bitmap = NULL;
902 :
903 : /* Advance inStart to show that the "D" message has been processed. */
904 0 : conn->inStart = conn->inCursor;
905 :
906 : /* Process the collected row */
907 0 : errmsg = NULL;
908 0 : if (pqRowProcessor(conn, &errmsg))
909 0 : return 0; /* normal, successful exit */
910 :
911 0 : goto set_error_result; /* pqRowProcessor failed, report it */
912 :
913 : advance_and_error:
914 :
915 : /*
916 : * Discard the failed message. Unfortunately we don't know for sure where
917 : * the end is, so just throw away everything in the input buffer. This is
918 : * not very desirable but it's the best we can do in protocol v2.
919 : */
920 0 : conn->inStart = conn->inEnd;
921 :
922 : set_error_result:
923 :
924 : /*
925 : * Replace partially constructed result with an error result. First
926 : * discard the old result to try to win back some memory.
927 : */
928 0 : pqClearAsyncResult(conn);
929 :
930 : /*
931 : * If preceding code didn't provide an error message, assume "out of
932 : * memory" was meant. The advantage of having this special case is that
933 : * freeing the old result first greatly improves the odds that gettext()
934 : * will succeed in providing a translation.
935 : */
936 0 : if (!errmsg)
937 0 : errmsg = libpq_gettext("out of memory for query result");
938 :
939 0 : printfPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
940 :
941 : /*
942 : * XXX: if PQmakeEmptyPGresult() fails, there's probably not much we can
943 : * do to recover...
944 : */
945 0 : conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
946 0 : conn->asyncStatus = PGASYNC_READY;
947 :
948 : EOFexit:
949 0 : if (bitmap != NULL && bitmap != std_bitmap)
950 0 : free(bitmap);
951 0 : return EOF;
952 : }
953 :
954 :
955 : /*
956 : * Attempt to read an Error or Notice response message.
957 : * This is possible in several places, so we break it out as a subroutine.
958 : * Entry: 'E' or 'N' message type has already been consumed.
959 : * Exit: returns 0 if successfully consumed message.
960 : * returns EOF if not enough data.
961 : */
962 : static int
963 0 : pqGetErrorNotice2(PGconn *conn, bool isError)
964 : {
965 0 : PGresult *res = NULL;
966 : PQExpBufferData workBuf;
967 : char *startp;
968 : char *splitp;
969 :
970 : /*
971 : * Since the message might be pretty long, we create a temporary
972 : * PQExpBuffer rather than using conn->workBuffer. workBuffer is intended
973 : * for stuff that is expected to be short.
974 : */
975 0 : initPQExpBuffer(&workBuf);
976 0 : if (pqGets(&workBuf, conn))
977 0 : goto failure;
978 :
979 : /*
980 : * Make a PGresult to hold the message. We temporarily lie about the
981 : * result status, so that PQmakeEmptyPGresult doesn't uselessly copy
982 : * conn->errorMessage.
983 : *
984 : * NB: This allocation can fail, if you run out of memory. The rest of the
985 : * function handles that gracefully, and we still try to set the error
986 : * message as the connection's error message.
987 : */
988 0 : res = PQmakeEmptyPGresult(conn, PGRES_EMPTY_QUERY);
989 0 : if (res)
990 : {
991 0 : res->resultStatus = isError ? PGRES_FATAL_ERROR : PGRES_NONFATAL_ERROR;
992 0 : res->errMsg = pqResultStrdup(res, workBuf.data);
993 : }
994 :
995 : /*
996 : * Break the message into fields. We can't do very much here, but we can
997 : * split the severity code off, and remove trailing newlines. Also, we use
998 : * the heuristic that the primary message extends only to the first
999 : * newline --- anything after that is detail message. (In some cases it'd
1000 : * be better classed as hint, but we can hardly be expected to guess that
1001 : * here.)
1002 : */
1003 0 : while (workBuf.len > 0 && workBuf.data[workBuf.len - 1] == '\n')
1004 0 : workBuf.data[--workBuf.len] = '\0';
1005 0 : splitp = strstr(workBuf.data, ": ");
1006 0 : if (splitp)
1007 : {
1008 : /* what comes before the colon is severity */
1009 0 : *splitp = '\0';
1010 0 : pqSaveMessageField(res, PG_DIAG_SEVERITY, workBuf.data);
1011 0 : startp = splitp + 3;
1012 : }
1013 : else
1014 : {
1015 : /* can't find a colon? oh well... */
1016 0 : startp = workBuf.data;
1017 : }
1018 0 : splitp = strchr(startp, '\n');
1019 0 : if (splitp)
1020 : {
1021 : /* what comes before the newline is primary message */
1022 0 : *splitp++ = '\0';
1023 0 : pqSaveMessageField(res, PG_DIAG_MESSAGE_PRIMARY, startp);
1024 : /* the rest is detail; strip any leading whitespace */
1025 0 : while (*splitp && isspace((unsigned char) *splitp))
1026 0 : splitp++;
1027 0 : pqSaveMessageField(res, PG_DIAG_MESSAGE_DETAIL, splitp);
1028 : }
1029 : else
1030 : {
1031 : /* single-line message, so all primary */
1032 0 : pqSaveMessageField(res, PG_DIAG_MESSAGE_PRIMARY, startp);
1033 : }
1034 :
1035 : /*
1036 : * Either save error as current async result, or just emit the notice.
1037 : * Also, if it's an error and we were in a transaction block, assume the
1038 : * server has now gone to error-in-transaction state.
1039 : */
1040 0 : if (isError)
1041 : {
1042 0 : pqClearAsyncResult(conn);
1043 0 : conn->result = res;
1044 0 : resetPQExpBuffer(&conn->errorMessage);
1045 0 : if (res && !PQExpBufferDataBroken(workBuf) && res->errMsg)
1046 0 : appendPQExpBufferStr(&conn->errorMessage, res->errMsg);
1047 : else
1048 0 : printfPQExpBuffer(&conn->errorMessage,
1049 : libpq_gettext("out of memory"));
1050 0 : if (conn->xactStatus == PQTRANS_INTRANS)
1051 0 : conn->xactStatus = PQTRANS_INERROR;
1052 : }
1053 : else
1054 : {
1055 0 : if (res)
1056 : {
1057 0 : if (res->noticeHooks.noticeRec != NULL)
1058 0 : (*res->noticeHooks.noticeRec) (res->noticeHooks.noticeRecArg, res);
1059 0 : PQclear(res);
1060 : }
1061 : }
1062 :
1063 0 : termPQExpBuffer(&workBuf);
1064 0 : return 0;
1065 :
1066 : failure:
1067 0 : if (res)
1068 0 : PQclear(res);
1069 0 : termPQExpBuffer(&workBuf);
1070 0 : return EOF;
1071 : }
1072 :
1073 : /*
1074 : * checkXactStatus - attempt to track transaction-block status of server
1075 : *
1076 : * This is called each time we receive a command-complete message. By
1077 : * watching for messages from BEGIN/COMMIT/ROLLBACK commands, we can do
1078 : * a passable job of tracking the server's xact status. BUT: this does
1079 : * not work at all on 7.3 servers with AUTOCOMMIT OFF. (Man, was that
1080 : * feature ever a mistake.) Caveat user.
1081 : *
1082 : * The tags known here are all those used as far back as 7.0; is it worth
1083 : * adding those from even-older servers?
1084 : */
1085 : static void
1086 0 : checkXactStatus(PGconn *conn, const char *cmdTag)
1087 : {
1088 0 : if (strcmp(cmdTag, "BEGIN") == 0)
1089 0 : conn->xactStatus = PQTRANS_INTRANS;
1090 0 : else if (strcmp(cmdTag, "COMMIT") == 0)
1091 0 : conn->xactStatus = PQTRANS_IDLE;
1092 0 : else if (strcmp(cmdTag, "ROLLBACK") == 0)
1093 0 : conn->xactStatus = PQTRANS_IDLE;
1094 0 : else if (strcmp(cmdTag, "START TRANSACTION") == 0) /* 7.3 only */
1095 0 : conn->xactStatus = PQTRANS_INTRANS;
1096 :
1097 : /*
1098 : * Normally we get into INERROR state by detecting an Error message.
1099 : * However, if we see one of these tags then we know for sure the server
1100 : * is in abort state ...
1101 : */
1102 0 : else if (strcmp(cmdTag, "*ABORT STATE*") == 0) /* pre-7.3 only */
1103 0 : conn->xactStatus = PQTRANS_INERROR;
1104 0 : }
1105 :
1106 : /*
1107 : * Attempt to read a Notify response message.
1108 : * This is possible in several places, so we break it out as a subroutine.
1109 : * Entry: 'A' message type and length have already been consumed.
1110 : * Exit: returns 0 if successfully consumed Notify message.
1111 : * returns EOF if not enough data.
1112 : */
1113 : static int
1114 0 : getNotify(PGconn *conn)
1115 : {
1116 : int be_pid;
1117 : int nmlen;
1118 : PGnotify *newNotify;
1119 :
1120 0 : if (pqGetInt(&be_pid, 4, conn))
1121 0 : return EOF;
1122 0 : if (pqGets(&conn->workBuffer, conn))
1123 0 : return EOF;
1124 :
1125 : /*
1126 : * Store the relation name right after the PQnotify structure so it can
1127 : * all be freed at once. We don't use NAMEDATALEN because we don't want
1128 : * to tie this interface to a specific server name length.
1129 : */
1130 0 : nmlen = strlen(conn->workBuffer.data);
1131 0 : newNotify = (PGnotify *) malloc(sizeof(PGnotify) + nmlen + 1);
1132 0 : if (newNotify)
1133 : {
1134 0 : newNotify->relname = (char *) newNotify + sizeof(PGnotify);
1135 0 : strcpy(newNotify->relname, conn->workBuffer.data);
1136 : /* fake up an empty-string extra field */
1137 0 : newNotify->extra = newNotify->relname + nmlen;
1138 0 : newNotify->be_pid = be_pid;
1139 0 : newNotify->next = NULL;
1140 0 : if (conn->notifyTail)
1141 0 : conn->notifyTail->next = newNotify;
1142 : else
1143 0 : conn->notifyHead = newNotify;
1144 0 : conn->notifyTail = newNotify;
1145 : }
1146 :
1147 0 : return 0;
1148 : }
1149 :
1150 :
1151 : /*
1152 : * PQgetCopyData - read a row of data from the backend during COPY OUT
1153 : *
1154 : * If successful, sets *buffer to point to a malloc'd row of data, and
1155 : * returns row length (always > 0) as result.
1156 : * Returns 0 if no row available yet (only possible if async is true),
1157 : * -1 if end of copy (consult PQgetResult), or -2 if error (consult
1158 : * PQerrorMessage).
1159 : */
1160 : int
1161 0 : pqGetCopyData2(PGconn *conn, char **buffer, int async)
1162 : {
1163 : bool found;
1164 : int msgLength;
1165 :
1166 : for (;;)
1167 : {
1168 : /*
1169 : * Do we have a complete line of data?
1170 : */
1171 0 : conn->inCursor = conn->inStart;
1172 0 : found = false;
1173 0 : while (conn->inCursor < conn->inEnd)
1174 : {
1175 0 : char c = conn->inBuffer[conn->inCursor++];
1176 :
1177 0 : if (c == '\n')
1178 : {
1179 0 : found = true;
1180 0 : break;
1181 : }
1182 : }
1183 0 : if (!found)
1184 0 : goto nodata;
1185 0 : msgLength = conn->inCursor - conn->inStart;
1186 :
1187 : /*
1188 : * If it's the end-of-data marker, consume it, exit COPY_OUT mode, and
1189 : * let caller read status with PQgetResult().
1190 : */
1191 0 : if (msgLength == 3 &&
1192 0 : strncmp(&conn->inBuffer[conn->inStart], "\\.\n", 3) == 0)
1193 : {
1194 0 : conn->inStart = conn->inCursor;
1195 0 : conn->asyncStatus = PGASYNC_BUSY;
1196 0 : return -1;
1197 : }
1198 :
1199 : /*
1200 : * Pass the line back to the caller.
1201 : */
1202 0 : *buffer = (char *) malloc(msgLength + 1);
1203 0 : if (*buffer == NULL)
1204 : {
1205 0 : printfPQExpBuffer(&conn->errorMessage,
1206 : libpq_gettext("out of memory\n"));
1207 0 : return -2;
1208 : }
1209 0 : memcpy(*buffer, &conn->inBuffer[conn->inStart], msgLength);
1210 0 : (*buffer)[msgLength] = '\0'; /* Add terminating null */
1211 :
1212 : /* Mark message consumed */
1213 0 : conn->inStart = conn->inCursor;
1214 :
1215 0 : return msgLength;
1216 :
1217 : nodata:
1218 : /* Don't block if async read requested */
1219 0 : if (async)
1220 0 : return 0;
1221 : /* Need to load more data */
1222 0 : if (pqWait(TRUE, FALSE, conn) ||
1223 0 : pqReadData(conn) < 0)
1224 0 : return -2;
1225 0 : }
1226 : }
1227 :
1228 :
1229 : /*
1230 : * PQgetline - gets a newline-terminated string from the backend.
1231 : *
1232 : * See fe-exec.c for documentation.
1233 : */
1234 : int
1235 0 : pqGetline2(PGconn *conn, char *s, int maxlen)
1236 : {
1237 0 : int result = 1; /* return value if buffer overflows */
1238 :
1239 0 : if (conn->sock == PGINVALID_SOCKET ||
1240 0 : conn->asyncStatus != PGASYNC_COPY_OUT)
1241 : {
1242 0 : *s = '\0';
1243 0 : return EOF;
1244 : }
1245 :
1246 : /*
1247 : * Since this is a purely synchronous routine, we don't bother to maintain
1248 : * conn->inCursor; there is no need to back up.
1249 : */
1250 0 : while (maxlen > 1)
1251 : {
1252 0 : if (conn->inStart < conn->inEnd)
1253 : {
1254 0 : char c = conn->inBuffer[conn->inStart++];
1255 :
1256 0 : if (c == '\n')
1257 : {
1258 0 : result = 0; /* success exit */
1259 0 : break;
1260 : }
1261 0 : *s++ = c;
1262 0 : maxlen--;
1263 : }
1264 : else
1265 : {
1266 : /* need to load more data */
1267 0 : if (pqWait(TRUE, FALSE, conn) ||
1268 0 : pqReadData(conn) < 0)
1269 : {
1270 0 : result = EOF;
1271 0 : break;
1272 : }
1273 : }
1274 : }
1275 0 : *s = '\0';
1276 :
1277 0 : return result;
1278 : }
1279 :
1280 : /*
1281 : * PQgetlineAsync - gets a COPY data row without blocking.
1282 : *
1283 : * See fe-exec.c for documentation.
1284 : */
1285 : int
1286 0 : pqGetlineAsync2(PGconn *conn, char *buffer, int bufsize)
1287 : {
1288 : int avail;
1289 :
1290 0 : if (conn->asyncStatus != PGASYNC_COPY_OUT)
1291 0 : return -1; /* we are not doing a copy... */
1292 :
1293 : /*
1294 : * Move data from libpq's buffer to the caller's. We want to accept data
1295 : * only in units of whole lines, not partial lines. This ensures that we
1296 : * can recognize the terminator line "\\.\n". (Otherwise, if it happened
1297 : * to cross a packet/buffer boundary, we might hand the first one or two
1298 : * characters off to the caller, which we shouldn't.)
1299 : */
1300 :
1301 0 : conn->inCursor = conn->inStart;
1302 :
1303 0 : avail = bufsize;
1304 0 : while (avail > 0 && conn->inCursor < conn->inEnd)
1305 : {
1306 0 : char c = conn->inBuffer[conn->inCursor++];
1307 :
1308 0 : *buffer++ = c;
1309 0 : --avail;
1310 0 : if (c == '\n')
1311 : {
1312 : /* Got a complete line; mark the data removed from libpq */
1313 0 : conn->inStart = conn->inCursor;
1314 : /* Is it the endmarker line? */
1315 0 : if (bufsize - avail == 3 && buffer[-3] == '\\' && buffer[-2] == '.')
1316 0 : return -1;
1317 : /* No, return the data line to the caller */
1318 0 : return bufsize - avail;
1319 : }
1320 : }
1321 :
1322 : /*
1323 : * We don't have a complete line. We'd prefer to leave it in libpq's
1324 : * buffer until the rest arrives, but there is a special case: what if the
1325 : * line is longer than the buffer the caller is offering us? In that case
1326 : * we'd better hand over a partial line, else we'd get into an infinite
1327 : * loop. Do this in a way that ensures we can't misrecognize a terminator
1328 : * line later: leave last 3 characters in libpq buffer.
1329 : */
1330 0 : if (avail == 0 && bufsize > 3)
1331 : {
1332 0 : conn->inStart = conn->inCursor - 3;
1333 0 : return bufsize - 3;
1334 : }
1335 0 : return 0;
1336 : }
1337 :
1338 : /*
1339 : * PQendcopy
1340 : *
1341 : * See fe-exec.c for documentation.
1342 : */
1343 : int
1344 0 : pqEndcopy2(PGconn *conn)
1345 : {
1346 : PGresult *result;
1347 :
1348 0 : if (conn->asyncStatus != PGASYNC_COPY_IN &&
1349 0 : conn->asyncStatus != PGASYNC_COPY_OUT)
1350 : {
1351 0 : printfPQExpBuffer(&conn->errorMessage,
1352 : libpq_gettext("no COPY in progress\n"));
1353 0 : return 1;
1354 : }
1355 :
1356 : /*
1357 : * make sure no data is waiting to be sent, abort if we are non-blocking
1358 : * and the flush fails
1359 : */
1360 0 : if (pqFlush(conn) && pqIsnonblocking(conn))
1361 0 : return 1;
1362 :
1363 : /* non blocking connections may have to abort at this point. */
1364 0 : if (pqIsnonblocking(conn) && PQisBusy(conn))
1365 0 : return 1;
1366 :
1367 : /* Return to active duty */
1368 0 : conn->asyncStatus = PGASYNC_BUSY;
1369 0 : resetPQExpBuffer(&conn->errorMessage);
1370 :
1371 : /* Wait for the completion response */
1372 0 : result = PQgetResult(conn);
1373 :
1374 : /* Expecting a successful result */
1375 0 : if (result && result->resultStatus == PGRES_COMMAND_OK)
1376 : {
1377 0 : PQclear(result);
1378 0 : return 0;
1379 : }
1380 :
1381 : /*
1382 : * Trouble. For backwards-compatibility reasons, we issue the error
1383 : * message as if it were a notice (would be nice to get rid of this
1384 : * silliness, but too many apps probably don't handle errors from
1385 : * PQendcopy reasonably). Note that the app can still obtain the error
1386 : * status from the PGconn object.
1387 : */
1388 0 : if (conn->errorMessage.len > 0)
1389 : {
1390 : /* We have to strip the trailing newline ... pain in neck... */
1391 0 : char svLast = conn->errorMessage.data[conn->errorMessage.len - 1];
1392 :
1393 0 : if (svLast == '\n')
1394 0 : conn->errorMessage.data[conn->errorMessage.len - 1] = '\0';
1395 0 : pqInternalNotice(&conn->noticeHooks, "%s", conn->errorMessage.data);
1396 0 : conn->errorMessage.data[conn->errorMessage.len - 1] = svLast;
1397 : }
1398 :
1399 0 : PQclear(result);
1400 :
1401 : /*
1402 : * The worst case is that we've lost sync with the backend entirely due to
1403 : * application screwup of the copy in/out protocol. To recover, reset the
1404 : * connection (talk about using a sledgehammer...)
1405 : */
1406 0 : pqInternalNotice(&conn->noticeHooks,
1407 : "lost synchronization with server, resetting connection");
1408 :
1409 : /*
1410 : * Users doing non-blocking connections need to handle the reset
1411 : * themselves, they'll need to check the connection status if we return an
1412 : * error.
1413 : */
1414 0 : if (pqIsnonblocking(conn))
1415 0 : PQresetStart(conn);
1416 : else
1417 0 : PQreset(conn);
1418 :
1419 0 : return 1;
1420 : }
1421 :
1422 :
1423 : /*
1424 : * PQfn - Send a function call to the POSTGRES backend.
1425 : *
1426 : * See fe-exec.c for documentation.
1427 : */
1428 : PGresult *
1429 0 : pqFunctionCall2(PGconn *conn, Oid fnid,
1430 : int *result_buf, int *actual_result_len,
1431 : int result_is_int,
1432 : const PQArgBlock *args, int nargs)
1433 : {
1434 0 : bool needInput = false;
1435 0 : ExecStatusType status = PGRES_FATAL_ERROR;
1436 : char id;
1437 : int i;
1438 :
1439 : /* PQfn already validated connection state */
1440 :
1441 0 : if (pqPutMsgStart('F', false, conn) < 0 || /* function call msg */
1442 0 : pqPuts(" ", conn) < 0 || /* dummy string */
1443 0 : pqPutInt(fnid, 4, conn) != 0 || /* function id */
1444 0 : pqPutInt(nargs, 4, conn) != 0) /* # of args */
1445 : {
1446 0 : pqHandleSendFailure(conn);
1447 0 : return NULL;
1448 : }
1449 :
1450 0 : for (i = 0; i < nargs; ++i)
1451 : { /* len.int4 + contents */
1452 0 : if (pqPutInt(args[i].len, 4, conn))
1453 : {
1454 0 : pqHandleSendFailure(conn);
1455 0 : return NULL;
1456 : }
1457 :
1458 0 : if (args[i].isint)
1459 : {
1460 0 : if (pqPutInt(args[i].u.integer, 4, conn))
1461 : {
1462 0 : pqHandleSendFailure(conn);
1463 0 : return NULL;
1464 : }
1465 : }
1466 : else
1467 : {
1468 0 : if (pqPutnchar((char *) args[i].u.ptr, args[i].len, conn))
1469 : {
1470 0 : pqHandleSendFailure(conn);
1471 0 : return NULL;
1472 : }
1473 : }
1474 : }
1475 :
1476 0 : if (pqPutMsgEnd(conn) < 0 ||
1477 0 : pqFlush(conn))
1478 : {
1479 0 : pqHandleSendFailure(conn);
1480 0 : return NULL;
1481 : }
1482 :
1483 : for (;;)
1484 : {
1485 0 : if (needInput)
1486 : {
1487 : /* Wait for some data to arrive (or for the channel to close) */
1488 0 : if (pqWait(TRUE, FALSE, conn) ||
1489 0 : pqReadData(conn) < 0)
1490 : break;
1491 : }
1492 :
1493 : /*
1494 : * Scan the message. If we run out of data, loop around to try again.
1495 : */
1496 0 : conn->inCursor = conn->inStart;
1497 0 : needInput = true;
1498 :
1499 0 : if (pqGetc(&id, conn))
1500 0 : continue;
1501 :
1502 : /*
1503 : * We should see V or E response to the command, but might get N
1504 : * and/or A notices first. We also need to swallow the final Z before
1505 : * returning.
1506 : */
1507 0 : switch (id)
1508 : {
1509 : case 'V': /* function result */
1510 0 : if (pqGetc(&id, conn))
1511 0 : continue;
1512 0 : if (id == 'G')
1513 : {
1514 : /* function returned nonempty value */
1515 0 : if (pqGetInt(actual_result_len, 4, conn))
1516 0 : continue;
1517 0 : if (result_is_int)
1518 : {
1519 0 : if (pqGetInt(result_buf, 4, conn))
1520 0 : continue;
1521 : }
1522 : else
1523 : {
1524 0 : if (pqGetnchar((char *) result_buf,
1525 0 : *actual_result_len,
1526 : conn))
1527 0 : continue;
1528 : }
1529 0 : if (pqGetc(&id, conn)) /* get the last '0' */
1530 0 : continue;
1531 : }
1532 0 : if (id == '0')
1533 : {
1534 : /* correctly finished function result message */
1535 0 : status = PGRES_COMMAND_OK;
1536 : }
1537 : else
1538 : {
1539 : /* The backend violates the protocol. */
1540 0 : printfPQExpBuffer(&conn->errorMessage,
1541 : libpq_gettext("protocol error: id=0x%x\n"),
1542 : id);
1543 0 : pqSaveErrorResult(conn);
1544 0 : conn->inStart = conn->inCursor;
1545 0 : return pqPrepareAsyncResult(conn);
1546 : }
1547 0 : break;
1548 : case 'E': /* error return */
1549 0 : if (pqGetErrorNotice2(conn, true))
1550 0 : continue;
1551 0 : status = PGRES_FATAL_ERROR;
1552 0 : break;
1553 : case 'A': /* notify message */
1554 : /* handle notify and go back to processing return values */
1555 0 : if (getNotify(conn))
1556 0 : continue;
1557 0 : break;
1558 : case 'N': /* notice */
1559 : /* handle notice and go back to processing return values */
1560 0 : if (pqGetErrorNotice2(conn, false))
1561 0 : continue;
1562 0 : break;
1563 : case 'Z': /* backend is ready for new query */
1564 : /* consume the message and exit */
1565 0 : conn->inStart = conn->inCursor;
1566 : /* if we saved a result object (probably an error), use it */
1567 0 : if (conn->result)
1568 0 : return pqPrepareAsyncResult(conn);
1569 0 : return PQmakeEmptyPGresult(conn, status);
1570 : default:
1571 : /* The backend violates the protocol. */
1572 0 : printfPQExpBuffer(&conn->errorMessage,
1573 : libpq_gettext("protocol error: id=0x%x\n"),
1574 : id);
1575 0 : pqSaveErrorResult(conn);
1576 0 : conn->inStart = conn->inCursor;
1577 0 : return pqPrepareAsyncResult(conn);
1578 : }
1579 : /* Completed this message, keep going */
1580 0 : conn->inStart = conn->inCursor;
1581 0 : needInput = false;
1582 0 : }
1583 :
1584 : /*
1585 : * We fall out of the loop only upon failing to read data.
1586 : * conn->errorMessage has been set by pqWait or pqReadData. We want to
1587 : * append it to any already-received error message.
1588 : */
1589 0 : pqSaveErrorResult(conn);
1590 0 : return pqPrepareAsyncResult(conn);
1591 : }
1592 :
1593 :
1594 : /*
1595 : * Construct startup packet
1596 : *
1597 : * Returns a malloc'd packet buffer, or NULL if out of memory
1598 : */
1599 : char *
1600 0 : pqBuildStartupPacket2(PGconn *conn, int *packetlen,
1601 : const PQEnvironmentOption *options)
1602 : {
1603 : StartupPacket *startpacket;
1604 :
1605 0 : *packetlen = sizeof(StartupPacket);
1606 0 : startpacket = (StartupPacket *) malloc(sizeof(StartupPacket));
1607 0 : if (!startpacket)
1608 0 : return NULL;
1609 :
1610 0 : MemSet(startpacket, 0, sizeof(StartupPacket));
1611 :
1612 0 : startpacket->protoVersion = htonl(conn->pversion);
1613 :
1614 : /* strncpy is safe here: postmaster will handle full fields correctly */
1615 0 : strncpy(startpacket->user, conn->pguser, SM_USER);
1616 0 : strncpy(startpacket->database, conn->dbName, SM_DATABASE);
1617 0 : strncpy(startpacket->tty, conn->pgtty, SM_TTY);
1618 :
1619 0 : if (conn->pgoptions)
1620 0 : strncpy(startpacket->options, conn->pgoptions, SM_OPTIONS);
1621 :
1622 0 : return (char *) startpacket;
1623 : }
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