Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * FILE
4 : * fe-misc.c
5 : *
6 : * DESCRIPTION
7 : * miscellaneous useful functions
8 : *
9 : * The communication routines here are analogous to the ones in
10 : * backend/libpq/pqcomm.c and backend/libpq/pqformat.c, but operate
11 : * in the considerably different environment of the frontend libpq.
12 : * In particular, we work with a bare nonblock-mode socket, rather than
13 : * a stdio stream, so that we can avoid unwanted blocking of the application.
14 : *
15 : * XXX: MOVE DEBUG PRINTOUT TO HIGHER LEVEL. As is, block and restart
16 : * will cause repeat printouts.
17 : *
18 : * We must speak the same transmitted data representations as the backend
19 : * routines.
20 : *
21 : *
22 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
23 : * Portions Copyright (c) 1994, Regents of the University of California
24 : *
25 : * IDENTIFICATION
26 : * src/interfaces/libpq/fe-misc.c
27 : *
28 : *-------------------------------------------------------------------------
29 : */
30 :
31 : #include "postgres_fe.h"
32 :
33 : #include <signal.h>
34 : #include <time.h>
35 :
36 : #ifdef WIN32
37 : #include "win32.h"
38 : #else
39 : #include <unistd.h>
40 : #include <sys/select.h>
41 : #include <sys/time.h>
42 : #endif
43 :
44 : #ifdef HAVE_POLL_H
45 : #include <poll.h>
46 : #endif
47 :
48 : #include "libpq-fe.h"
49 : #include "libpq-int.h"
50 : #include "mb/pg_wchar.h"
51 : #include "pg_config_paths.h"
52 : #include "port/pg_bswap.h"
53 :
54 : static int pqPutMsgBytes(const void *buf, size_t len, PGconn *conn);
55 : static int pqSendSome(PGconn *conn, int len);
56 : static int pqSocketCheck(PGconn *conn, int forRead, int forWrite,
57 : pg_usec_time_t end_time);
58 :
59 : /*
60 : * PQlibVersion: return the libpq version number
61 : */
62 : int
63 0 : PQlibVersion(void)
64 : {
65 0 : return PG_VERSION_NUM;
66 : }
67 :
68 :
69 : /*
70 : * pqGetc: read 1 character from the connection
71 : *
72 : * All these routines return 0 on success, EOF on error.
73 : * Note that for the Get routines, EOF only means there is not enough
74 : * data in the buffer, not that there is necessarily a hard error.
75 : */
76 : int
77 25582998 : pqGetc(char *result, PGconn *conn)
78 : {
79 25582998 : if (conn->inCursor >= conn->inEnd)
80 3441206 : return EOF;
81 :
82 22141792 : *result = conn->inBuffer[conn->inCursor++];
83 :
84 22141792 : return 0;
85 : }
86 :
87 :
88 : /*
89 : * pqPutc: write 1 char to the current message
90 : */
91 : int
92 22266 : pqPutc(char c, PGconn *conn)
93 : {
94 22266 : if (pqPutMsgBytes(&c, 1, conn))
95 0 : return EOF;
96 :
97 22266 : return 0;
98 : }
99 :
100 :
101 : /*
102 : * pqGets[_append]:
103 : * read a null-terminated string from the connection,
104 : * and store it in an expansible PQExpBuffer.
105 : * If we run out of memory, all of the string is still read,
106 : * but the excess characters are silently discarded.
107 : */
108 : static int
109 4183510 : pqGets_internal(PQExpBuffer buf, PGconn *conn, bool resetbuffer)
110 : {
111 : /* Copy conn data to locals for faster search loop */
112 4183510 : char *inBuffer = conn->inBuffer;
113 4183510 : int inCursor = conn->inCursor;
114 4183510 : int inEnd = conn->inEnd;
115 : int slen;
116 :
117 79508728 : while (inCursor < inEnd && inBuffer[inCursor])
118 75325218 : inCursor++;
119 :
120 4183510 : if (inCursor >= inEnd)
121 0 : return EOF;
122 :
123 4183510 : slen = inCursor - conn->inCursor;
124 :
125 4183510 : if (resetbuffer)
126 4183510 : resetPQExpBuffer(buf);
127 :
128 4183510 : appendBinaryPQExpBuffer(buf, inBuffer + conn->inCursor, slen);
129 :
130 4183510 : conn->inCursor = ++inCursor;
131 :
132 4183510 : return 0;
133 : }
134 :
135 : int
136 4183510 : pqGets(PQExpBuffer buf, PGconn *conn)
137 : {
138 4183510 : return pqGets_internal(buf, conn, true);
139 : }
140 :
141 : int
142 0 : pqGets_append(PQExpBuffer buf, PGconn *conn)
143 : {
144 0 : return pqGets_internal(buf, conn, false);
145 : }
146 :
147 :
148 : /*
149 : * pqPuts: write a null-terminated string to the current message
150 : */
151 : int
152 752046 : pqPuts(const char *s, PGconn *conn)
153 : {
154 752046 : if (pqPutMsgBytes(s, strlen(s) + 1, conn))
155 0 : return EOF;
156 :
157 752046 : return 0;
158 : }
159 :
160 : /*
161 : * pqGetnchar:
162 : * read exactly len bytes in buffer s, no null termination
163 : */
164 : int
165 26974 : pqGetnchar(void *s, size_t len, PGconn *conn)
166 : {
167 26974 : if (len > (size_t) (conn->inEnd - conn->inCursor))
168 0 : return EOF;
169 :
170 26974 : memcpy(s, conn->inBuffer + conn->inCursor, len);
171 : /* no terminating null */
172 :
173 26974 : conn->inCursor += len;
174 :
175 26974 : return 0;
176 : }
177 :
178 : /*
179 : * pqSkipnchar:
180 : * skip over len bytes in input buffer.
181 : *
182 : * Note: this is primarily useful for its debug output, which should
183 : * be exactly the same as for pqGetnchar. We assume the data in question
184 : * will actually be used, but just isn't getting copied anywhere as yet.
185 : */
186 : int
187 40911696 : pqSkipnchar(size_t len, PGconn *conn)
188 : {
189 40911696 : if (len > (size_t) (conn->inEnd - conn->inCursor))
190 0 : return EOF;
191 :
192 40911696 : conn->inCursor += len;
193 :
194 40911696 : return 0;
195 : }
196 :
197 : /*
198 : * pqPutnchar:
199 : * write exactly len bytes to the current message
200 : */
201 : int
202 675604 : pqPutnchar(const void *s, size_t len, PGconn *conn)
203 : {
204 675604 : if (pqPutMsgBytes(s, len, conn))
205 0 : return EOF;
206 :
207 675604 : return 0;
208 : }
209 :
210 : /*
211 : * pqGetInt
212 : * read a 2 or 4 byte integer and convert from network byte order
213 : * to local byte order
214 : */
215 : int
216 79456448 : pqGetInt(int *result, size_t bytes, PGconn *conn)
217 : {
218 : uint16 tmp2;
219 : uint32 tmp4;
220 :
221 79456448 : switch (bytes)
222 : {
223 12308438 : case 2:
224 12308438 : if (conn->inCursor + 2 > conn->inEnd)
225 0 : return EOF;
226 12308438 : memcpy(&tmp2, conn->inBuffer + conn->inCursor, 2);
227 12308438 : conn->inCursor += 2;
228 12308438 : *result = (int) pg_ntoh16(tmp2);
229 12308438 : break;
230 67148010 : case 4:
231 67148010 : if (conn->inCursor + 4 > conn->inEnd)
232 5868 : return EOF;
233 67142142 : memcpy(&tmp4, conn->inBuffer + conn->inCursor, 4);
234 67142142 : conn->inCursor += 4;
235 67142142 : *result = (int) pg_ntoh32(tmp4);
236 67142142 : break;
237 0 : default:
238 0 : pqInternalNotice(&conn->noticeHooks,
239 : "integer of size %lu not supported by pqGetInt",
240 : (unsigned long) bytes);
241 0 : return EOF;
242 : }
243 :
244 79450580 : return 0;
245 : }
246 :
247 : /*
248 : * pqPutInt
249 : * write an integer of 2 or 4 bytes, converting from host byte order
250 : * to network byte order.
251 : */
252 : int
253 176414 : pqPutInt(int value, size_t bytes, PGconn *conn)
254 : {
255 : uint16 tmp2;
256 : uint32 tmp4;
257 :
258 176414 : switch (bytes)
259 : {
260 115186 : case 2:
261 115186 : tmp2 = pg_hton16((uint16) value);
262 115186 : if (pqPutMsgBytes((const char *) &tmp2, 2, conn))
263 0 : return EOF;
264 115186 : break;
265 61228 : case 4:
266 61228 : tmp4 = pg_hton32((uint32) value);
267 61228 : if (pqPutMsgBytes((const char *) &tmp4, 4, conn))
268 0 : return EOF;
269 61228 : break;
270 0 : default:
271 0 : pqInternalNotice(&conn->noticeHooks,
272 : "integer of size %lu not supported by pqPutInt",
273 : (unsigned long) bytes);
274 0 : return EOF;
275 : }
276 :
277 176414 : return 0;
278 : }
279 :
280 : /*
281 : * Make sure conn's output buffer can hold bytes_needed bytes (caller must
282 : * include already-stored data into the value!)
283 : *
284 : * Returns 0 on success, EOF if failed to enlarge buffer
285 : */
286 : int
287 3044996 : pqCheckOutBufferSpace(size_t bytes_needed, PGconn *conn)
288 : {
289 3044996 : int newsize = conn->outBufSize;
290 : char *newbuf;
291 :
292 : /* Quick exit if we have enough space */
293 3044996 : if (bytes_needed <= (size_t) newsize)
294 3044930 : return 0;
295 :
296 : /*
297 : * If we need to enlarge the buffer, we first try to double it in size; if
298 : * that doesn't work, enlarge in multiples of 8K. This avoids thrashing
299 : * the malloc pool by repeated small enlargements.
300 : *
301 : * Note: tests for newsize > 0 are to catch integer overflow.
302 : */
303 : do
304 : {
305 158 : newsize *= 2;
306 158 : } while (newsize > 0 && bytes_needed > (size_t) newsize);
307 :
308 66 : if (newsize > 0 && bytes_needed <= (size_t) newsize)
309 : {
310 66 : newbuf = realloc(conn->outBuffer, newsize);
311 66 : if (newbuf)
312 : {
313 : /* realloc succeeded */
314 66 : conn->outBuffer = newbuf;
315 66 : conn->outBufSize = newsize;
316 66 : return 0;
317 : }
318 : }
319 :
320 0 : newsize = conn->outBufSize;
321 : do
322 : {
323 0 : newsize += 8192;
324 0 : } while (newsize > 0 && bytes_needed > (size_t) newsize);
325 :
326 0 : if (newsize > 0 && bytes_needed <= (size_t) newsize)
327 : {
328 0 : newbuf = realloc(conn->outBuffer, newsize);
329 0 : if (newbuf)
330 : {
331 : /* realloc succeeded */
332 0 : conn->outBuffer = newbuf;
333 0 : conn->outBufSize = newsize;
334 0 : return 0;
335 : }
336 : }
337 :
338 : /* realloc failed. Probably out of memory */
339 0 : appendPQExpBufferStr(&conn->errorMessage,
340 : "cannot allocate memory for output buffer\n");
341 0 : return EOF;
342 : }
343 :
344 : /*
345 : * Make sure conn's input buffer can hold bytes_needed bytes (caller must
346 : * include already-stored data into the value!)
347 : *
348 : * Returns 0 on success, EOF if failed to enlarge buffer
349 : */
350 : int
351 514790 : pqCheckInBufferSpace(size_t bytes_needed, PGconn *conn)
352 : {
353 514790 : int newsize = conn->inBufSize;
354 : char *newbuf;
355 :
356 : /* Quick exit if we have enough space */
357 514790 : if (bytes_needed <= (size_t) newsize)
358 294840 : return 0;
359 :
360 : /*
361 : * Before concluding that we need to enlarge the buffer, left-justify
362 : * whatever is in it and recheck. The caller's value of bytes_needed
363 : * includes any data to the left of inStart, but we can delete that in
364 : * preference to enlarging the buffer. It's slightly ugly to have this
365 : * function do this, but it's better than making callers worry about it.
366 : */
367 219950 : bytes_needed -= conn->inStart;
368 :
369 219950 : if (conn->inStart < conn->inEnd)
370 : {
371 219950 : if (conn->inStart > 0)
372 : {
373 219444 : memmove(conn->inBuffer, conn->inBuffer + conn->inStart,
374 219444 : conn->inEnd - conn->inStart);
375 219444 : conn->inEnd -= conn->inStart;
376 219444 : conn->inCursor -= conn->inStart;
377 219444 : conn->inStart = 0;
378 : }
379 : }
380 : else
381 : {
382 : /* buffer is logically empty, reset it */
383 0 : conn->inStart = conn->inCursor = conn->inEnd = 0;
384 : }
385 :
386 : /* Recheck whether we have enough space */
387 219950 : if (bytes_needed <= (size_t) newsize)
388 218722 : return 0;
389 :
390 : /*
391 : * If we need to enlarge the buffer, we first try to double it in size; if
392 : * that doesn't work, enlarge in multiples of 8K. This avoids thrashing
393 : * the malloc pool by repeated small enlargements.
394 : *
395 : * Note: tests for newsize > 0 are to catch integer overflow.
396 : */
397 : do
398 : {
399 2602 : newsize *= 2;
400 2602 : } while (newsize > 0 && bytes_needed > (size_t) newsize);
401 :
402 1228 : if (newsize > 0 && bytes_needed <= (size_t) newsize)
403 : {
404 1228 : newbuf = realloc(conn->inBuffer, newsize);
405 1228 : if (newbuf)
406 : {
407 : /* realloc succeeded */
408 1228 : conn->inBuffer = newbuf;
409 1228 : conn->inBufSize = newsize;
410 1228 : return 0;
411 : }
412 : }
413 :
414 0 : newsize = conn->inBufSize;
415 : do
416 : {
417 0 : newsize += 8192;
418 0 : } while (newsize > 0 && bytes_needed > (size_t) newsize);
419 :
420 0 : if (newsize > 0 && bytes_needed <= (size_t) newsize)
421 : {
422 0 : newbuf = realloc(conn->inBuffer, newsize);
423 0 : if (newbuf)
424 : {
425 : /* realloc succeeded */
426 0 : conn->inBuffer = newbuf;
427 0 : conn->inBufSize = newsize;
428 0 : return 0;
429 : }
430 : }
431 :
432 : /* realloc failed. Probably out of memory */
433 0 : appendPQExpBufferStr(&conn->errorMessage,
434 : "cannot allocate memory for input buffer\n");
435 0 : return EOF;
436 : }
437 :
438 : /*
439 : * pqParseDone: after a server-to-client message has successfully
440 : * been parsed, advance conn->inStart to account for it.
441 : */
442 : void
443 18303140 : pqParseDone(PGconn *conn, int newInStart)
444 : {
445 : /* trace server-to-client message */
446 18303140 : if (conn->Pfdebug)
447 434 : pqTraceOutputMessage(conn, conn->inBuffer + conn->inStart, false);
448 :
449 : /* Mark message as done */
450 18303140 : conn->inStart = newInStart;
451 18303140 : }
452 :
453 : /*
454 : * pqPutMsgStart: begin construction of a message to the server
455 : *
456 : * msg_type is the message type byte, or 0 for a message without type byte
457 : * (only startup messages have no type byte)
458 : *
459 : * Returns 0 on success, EOF on error
460 : *
461 : * The idea here is that we construct the message in conn->outBuffer,
462 : * beginning just past any data already in outBuffer (ie, at
463 : * outBuffer+outCount). We enlarge the buffer as needed to hold the message.
464 : * When the message is complete, we fill in the length word (if needed) and
465 : * then advance outCount past the message, making it eligible to send.
466 : *
467 : * The state variable conn->outMsgStart points to the incomplete message's
468 : * length word: it is either outCount or outCount+1 depending on whether
469 : * there is a type byte. The state variable conn->outMsgEnd is the end of
470 : * the data collected so far.
471 : */
472 : int
473 1418624 : pqPutMsgStart(char msg_type, PGconn *conn)
474 : {
475 : int lenPos;
476 : int endPos;
477 :
478 : /* allow room for message type byte */
479 1418624 : if (msg_type)
480 1391344 : endPos = conn->outCount + 1;
481 : else
482 27280 : endPos = conn->outCount;
483 :
484 : /* do we want a length word? */
485 1418624 : lenPos = endPos;
486 : /* allow room for message length */
487 1418624 : endPos += 4;
488 :
489 : /* make sure there is room for message header */
490 1418624 : if (pqCheckOutBufferSpace(endPos, conn))
491 0 : return EOF;
492 : /* okay, save the message type byte if any */
493 1418624 : if (msg_type)
494 1391344 : conn->outBuffer[conn->outCount] = msg_type;
495 : /* set up the message pointers */
496 1418624 : conn->outMsgStart = lenPos;
497 1418624 : conn->outMsgEnd = endPos;
498 : /* length word, if needed, will be filled in by pqPutMsgEnd */
499 :
500 1418624 : return 0;
501 : }
502 :
503 : /*
504 : * pqPutMsgBytes: add bytes to a partially-constructed message
505 : *
506 : * Returns 0 on success, EOF on error
507 : */
508 : static int
509 1626330 : pqPutMsgBytes(const void *buf, size_t len, PGconn *conn)
510 : {
511 : /* make sure there is room for it */
512 1626330 : if (pqCheckOutBufferSpace(conn->outMsgEnd + len, conn))
513 0 : return EOF;
514 : /* okay, save the data */
515 1626330 : memcpy(conn->outBuffer + conn->outMsgEnd, buf, len);
516 1626330 : conn->outMsgEnd += len;
517 : /* no Pfdebug call here, caller should do it */
518 1626330 : return 0;
519 : }
520 :
521 : /*
522 : * pqPutMsgEnd: finish constructing a message and possibly send it
523 : *
524 : * Returns 0 on success, EOF on error
525 : *
526 : * We don't actually send anything here unless we've accumulated at least
527 : * 8K worth of data (the typical size of a pipe buffer on Unix systems).
528 : * This avoids sending small partial packets. The caller must use pqFlush
529 : * when it's important to flush all the data out to the server.
530 : */
531 : int
532 1418624 : pqPutMsgEnd(PGconn *conn)
533 : {
534 : /* Fill in length word if needed */
535 1418624 : if (conn->outMsgStart >= 0)
536 : {
537 1418624 : uint32 msgLen = conn->outMsgEnd - conn->outMsgStart;
538 :
539 1418624 : msgLen = pg_hton32(msgLen);
540 1418624 : memcpy(conn->outBuffer + conn->outMsgStart, &msgLen, 4);
541 : }
542 :
543 : /* trace client-to-server message */
544 1418624 : if (conn->Pfdebug)
545 : {
546 394 : if (conn->outCount < conn->outMsgStart)
547 394 : pqTraceOutputMessage(conn, conn->outBuffer + conn->outCount, true);
548 : else
549 0 : pqTraceOutputNoTypeByteMessage(conn,
550 0 : conn->outBuffer + conn->outMsgStart);
551 : }
552 :
553 : /* Make message eligible to send */
554 1418624 : conn->outCount = conn->outMsgEnd;
555 :
556 : /* If appropriate, try to push out some data */
557 1418624 : if (conn->outCount >= 8192)
558 : {
559 4960 : int toSend = conn->outCount;
560 :
561 : /*
562 : * On Unix-pipe connections, it seems profitable to prefer sending
563 : * pipe-buffer-sized packets not randomly-sized ones, so retain the
564 : * last partial-8K chunk in our buffer for now. On TCP connections,
565 : * the advantage of that is far less clear. Moreover, it flat out
566 : * isn't safe when using SSL or GSSAPI, because those code paths have
567 : * API stipulations that if they fail to send all the data that was
568 : * offered in the previous write attempt, we mustn't offer less data
569 : * in this write attempt. The previous write attempt might've been
570 : * pqFlush attempting to send everything in the buffer, so we mustn't
571 : * offer less now. (Presently, we won't try to use SSL or GSSAPI on
572 : * Unix connections, so those checks are just Asserts. They'll have
573 : * to become part of the regular if-test if we ever change that.)
574 : */
575 4960 : if (conn->raddr.addr.ss_family == AF_UNIX)
576 : {
577 : #ifdef USE_SSL
578 : Assert(!conn->ssl_in_use);
579 : #endif
580 : #ifdef ENABLE_GSS
581 : Assert(!conn->gssenc);
582 : #endif
583 4960 : toSend -= toSend % 8192;
584 : }
585 :
586 4960 : if (pqSendSome(conn, toSend) < 0)
587 0 : return EOF;
588 : /* in nonblock mode, don't complain if unable to send it all */
589 : }
590 :
591 1418624 : return 0;
592 : }
593 :
594 : /* ----------
595 : * pqReadData: read more data, if any is available
596 : * Possible return values:
597 : * 1: successfully loaded at least one more byte
598 : * 0: no data is presently available, but no error detected
599 : * -1: error detected (including EOF = connection closure);
600 : * conn->errorMessage set
601 : * NOTE: callers must not assume that pointers or indexes into conn->inBuffer
602 : * remain valid across this call!
603 : * ----------
604 : */
605 : int
606 2130434 : pqReadData(PGconn *conn)
607 : {
608 2130434 : int someread = 0;
609 : int nread;
610 :
611 2130434 : if (conn->sock == PGINVALID_SOCKET)
612 : {
613 4 : libpq_append_conn_error(conn, "connection not open");
614 4 : return -1;
615 : }
616 :
617 : /* Left-justify any data in the buffer to make room */
618 2130430 : if (conn->inStart < conn->inEnd)
619 : {
620 426318 : if (conn->inStart > 0)
621 : {
622 130736 : memmove(conn->inBuffer, conn->inBuffer + conn->inStart,
623 130736 : conn->inEnd - conn->inStart);
624 130736 : conn->inEnd -= conn->inStart;
625 130736 : conn->inCursor -= conn->inStart;
626 130736 : conn->inStart = 0;
627 : }
628 : }
629 : else
630 : {
631 : /* buffer is logically empty, reset it */
632 1704112 : conn->inStart = conn->inCursor = conn->inEnd = 0;
633 : }
634 :
635 : /*
636 : * If the buffer is fairly full, enlarge it. We need to be able to enlarge
637 : * the buffer in case a single message exceeds the initial buffer size. We
638 : * enlarge before filling the buffer entirely so as to avoid asking the
639 : * kernel for a partial packet. The magic constant here should be large
640 : * enough for a TCP packet or Unix pipe bufferload. 8K is the usual pipe
641 : * buffer size, so...
642 : */
643 2130430 : if (conn->inBufSize - conn->inEnd < 8192)
644 : {
645 14 : if (pqCheckInBufferSpace(conn->inEnd + (size_t) 8192, conn))
646 : {
647 : /*
648 : * We don't insist that the enlarge worked, but we need some room
649 : */
650 0 : if (conn->inBufSize - conn->inEnd < 100)
651 0 : return -1; /* errorMessage already set */
652 : }
653 : }
654 :
655 : /* OK, try to read some data */
656 2341380 : retry3:
657 4682760 : nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
658 2341380 : conn->inBufSize - conn->inEnd);
659 2341380 : if (nread < 0)
660 : {
661 761006 : switch (SOCK_ERRNO)
662 : {
663 0 : case EINTR:
664 0 : goto retry3;
665 :
666 : /* Some systems return EAGAIN/EWOULDBLOCK for no data */
667 : #ifdef EAGAIN
668 760968 : case EAGAIN:
669 760968 : return someread;
670 : #endif
671 : #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
672 : case EWOULDBLOCK:
673 : return someread;
674 : #endif
675 :
676 : /* We might get ECONNRESET etc here if connection failed */
677 38 : case ALL_CONNECTION_FAILURE_ERRNOS:
678 38 : goto definitelyFailed;
679 :
680 0 : default:
681 : /* pqsecure_read set the error message for us */
682 0 : return -1;
683 : }
684 : }
685 1580374 : if (nread > 0)
686 : {
687 1580038 : conn->inEnd += nread;
688 :
689 : /*
690 : * Hack to deal with the fact that some kernels will only give us back
691 : * 1 packet per recv() call, even if we asked for more and there is
692 : * more available. If it looks like we are reading a long message,
693 : * loop back to recv() again immediately, until we run out of data or
694 : * buffer space. Without this, the block-and-restart behavior of
695 : * libpq's higher levels leads to O(N^2) performance on long messages.
696 : *
697 : * Since we left-justified the data above, conn->inEnd gives the
698 : * amount of data already read in the current message. We consider
699 : * the message "long" once we have acquired 32k ...
700 : */
701 1580038 : if (conn->inEnd > 32768 &&
702 399600 : (conn->inBufSize - conn->inEnd) >= 8192)
703 : {
704 210950 : someread = 1;
705 210950 : goto retry3;
706 : }
707 1369088 : return 1;
708 : }
709 :
710 336 : if (someread)
711 0 : return 1; /* got a zero read after successful tries */
712 :
713 : /*
714 : * A return value of 0 could mean just that no data is now available, or
715 : * it could mean EOF --- that is, the server has closed the connection.
716 : * Since we have the socket in nonblock mode, the only way to tell the
717 : * difference is to see if select() is saying that the file is ready.
718 : * Grumble. Fortunately, we don't expect this path to be taken much,
719 : * since in normal practice we should not be trying to read data unless
720 : * the file selected for reading already.
721 : *
722 : * In SSL mode it's even worse: SSL_read() could say WANT_READ and then
723 : * data could arrive before we make the pqReadReady() test, but the second
724 : * SSL_read() could still say WANT_READ because the data received was not
725 : * a complete SSL record. So we must play dumb and assume there is more
726 : * data, relying on the SSL layer to detect true EOF.
727 : */
728 :
729 : #ifdef USE_SSL
730 336 : if (conn->ssl_in_use)
731 168 : return 0;
732 : #endif
733 :
734 168 : switch (pqReadReady(conn))
735 : {
736 0 : case 0:
737 : /* definitely no data available */
738 0 : return 0;
739 168 : case 1:
740 : /* ready for read */
741 168 : break;
742 0 : default:
743 : /* we override pqReadReady's message with something more useful */
744 0 : goto definitelyEOF;
745 : }
746 :
747 : /*
748 : * Still not sure that it's EOF, because some data could have just
749 : * arrived.
750 : */
751 168 : retry4:
752 336 : nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
753 168 : conn->inBufSize - conn->inEnd);
754 168 : if (nread < 0)
755 : {
756 0 : switch (SOCK_ERRNO)
757 : {
758 0 : case EINTR:
759 0 : goto retry4;
760 :
761 : /* Some systems return EAGAIN/EWOULDBLOCK for no data */
762 : #ifdef EAGAIN
763 0 : case EAGAIN:
764 0 : return 0;
765 : #endif
766 : #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
767 : case EWOULDBLOCK:
768 : return 0;
769 : #endif
770 :
771 : /* We might get ECONNRESET etc here if connection failed */
772 0 : case ALL_CONNECTION_FAILURE_ERRNOS:
773 0 : goto definitelyFailed;
774 :
775 0 : default:
776 : /* pqsecure_read set the error message for us */
777 0 : return -1;
778 : }
779 : }
780 168 : if (nread > 0)
781 : {
782 0 : conn->inEnd += nread;
783 0 : return 1;
784 : }
785 :
786 : /*
787 : * OK, we are getting a zero read even though select() says ready. This
788 : * means the connection has been closed. Cope.
789 : */
790 168 : definitelyEOF:
791 168 : libpq_append_conn_error(conn, "server closed the connection unexpectedly\n"
792 : "\tThis probably means the server terminated abnormally\n"
793 : "\tbefore or while processing the request.");
794 :
795 : /* Come here if lower-level code already set a suitable errorMessage */
796 206 : definitelyFailed:
797 : /* Do *not* drop any already-read data; caller still wants it */
798 206 : pqDropConnection(conn, false);
799 206 : conn->status = CONNECTION_BAD; /* No more connection to backend */
800 206 : return -1;
801 : }
802 :
803 : /*
804 : * pqSendSome: send data waiting in the output buffer.
805 : *
806 : * len is how much to try to send (typically equal to outCount, but may
807 : * be less).
808 : *
809 : * Return 0 on success, -1 on failure and 1 when not all data could be sent
810 : * because the socket would block and the connection is non-blocking.
811 : *
812 : * Note that this is also responsible for consuming data from the socket
813 : * (putting it in conn->inBuffer) in any situation where we can't send
814 : * all the specified data immediately.
815 : *
816 : * If a socket-level write failure occurs, conn->write_failed is set and the
817 : * error message is saved in conn->write_err_msg, but we clear the output
818 : * buffer and return zero anyway; this is because callers should soldier on
819 : * until we have read what we can from the server and checked for an error
820 : * message. write_err_msg should be reported only when we are unable to
821 : * obtain a server error first. Much of that behavior is implemented at
822 : * lower levels, but this function deals with some edge cases.
823 : */
824 : static int
825 940272 : pqSendSome(PGconn *conn, int len)
826 : {
827 940272 : char *ptr = conn->outBuffer;
828 940272 : int remaining = conn->outCount;
829 940272 : int result = 0;
830 :
831 : /*
832 : * If we already had a write failure, we will never again try to send data
833 : * on that connection. Even if the kernel would let us, we've probably
834 : * lost message boundary sync with the server. conn->write_failed
835 : * therefore persists until the connection is reset, and we just discard
836 : * all data presented to be written. However, as long as we still have a
837 : * valid socket, we should continue to absorb data from the backend, so
838 : * that we can collect any final error messages.
839 : */
840 940272 : if (conn->write_failed)
841 : {
842 : /* conn->write_err_msg should be set up already */
843 0 : conn->outCount = 0;
844 : /* Absorb input data if any, and detect socket closure */
845 0 : if (conn->sock != PGINVALID_SOCKET)
846 : {
847 0 : if (pqReadData(conn) < 0)
848 0 : return -1;
849 : }
850 0 : return 0;
851 : }
852 :
853 940272 : if (conn->sock == PGINVALID_SOCKET)
854 : {
855 0 : conn->write_failed = true;
856 : /* Store error message in conn->write_err_msg, if possible */
857 : /* (strdup failure is OK, we'll cope later) */
858 0 : conn->write_err_msg = strdup(libpq_gettext("connection not open\n"));
859 : /* Discard queued data; no chance it'll ever be sent */
860 0 : conn->outCount = 0;
861 0 : return 0;
862 : }
863 :
864 : /* while there's still data to send */
865 1885008 : while (len > 0)
866 : {
867 : int sent;
868 :
869 : #ifndef WIN32
870 944742 : sent = pqsecure_write(conn, ptr, len);
871 : #else
872 :
873 : /*
874 : * Windows can fail on large sends, per KB article Q201213. The
875 : * failure-point appears to be different in different versions of
876 : * Windows, but 64k should always be safe.
877 : */
878 : sent = pqsecure_write(conn, ptr, Min(len, 65536));
879 : #endif
880 :
881 944742 : if (sent < 0)
882 : {
883 : /* Anything except EAGAIN/EWOULDBLOCK/EINTR is trouble */
884 4476 : switch (SOCK_ERRNO)
885 : {
886 : #ifdef EAGAIN
887 4476 : case EAGAIN:
888 4476 : break;
889 : #endif
890 : #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
891 : case EWOULDBLOCK:
892 : break;
893 : #endif
894 0 : case EINTR:
895 0 : continue;
896 :
897 0 : default:
898 : /* Discard queued data; no chance it'll ever be sent */
899 0 : conn->outCount = 0;
900 :
901 : /* Absorb input data if any, and detect socket closure */
902 0 : if (conn->sock != PGINVALID_SOCKET)
903 : {
904 0 : if (pqReadData(conn) < 0)
905 0 : return -1;
906 : }
907 :
908 : /*
909 : * Lower-level code should already have filled
910 : * conn->write_err_msg (and set conn->write_failed) or
911 : * conn->errorMessage. In the former case, we pretend
912 : * there's no problem; the write_failed condition will be
913 : * dealt with later. Otherwise, report the error now.
914 : */
915 0 : if (conn->write_failed)
916 0 : return 0;
917 : else
918 0 : return -1;
919 : }
920 : }
921 : else
922 : {
923 940266 : ptr += sent;
924 940266 : len -= sent;
925 940266 : remaining -= sent;
926 : }
927 :
928 944742 : if (len > 0)
929 : {
930 : /*
931 : * We didn't send it all, wait till we can send more.
932 : *
933 : * There are scenarios in which we can't send data because the
934 : * communications channel is full, but we cannot expect the server
935 : * to clear the channel eventually because it's blocked trying to
936 : * send data to us. (This can happen when we are sending a large
937 : * amount of COPY data, and the server has generated lots of
938 : * NOTICE responses.) To avoid a deadlock situation, we must be
939 : * prepared to accept and buffer incoming data before we try
940 : * again. Furthermore, it is possible that such incoming data
941 : * might not arrive until after we've gone to sleep. Therefore,
942 : * we wait for either read ready or write ready.
943 : *
944 : * In non-blocking mode, we don't wait here directly, but return 1
945 : * to indicate that data is still pending. The caller should wait
946 : * for both read and write ready conditions, and call
947 : * PQconsumeInput() on read ready, but just in case it doesn't, we
948 : * call pqReadData() ourselves before returning. That's not
949 : * enough if the data has not arrived yet, but it's the best we
950 : * can do, and works pretty well in practice. (The documentation
951 : * used to say that you only need to wait for write-ready, so
952 : * there are still plenty of applications like that out there.)
953 : *
954 : * Note that errors here don't result in write_failed becoming
955 : * set.
956 : */
957 4476 : if (pqReadData(conn) < 0)
958 : {
959 0 : result = -1; /* error message already set up */
960 0 : break;
961 : }
962 :
963 4476 : if (pqIsnonblocking(conn))
964 : {
965 6 : result = 1;
966 6 : break;
967 : }
968 :
969 4470 : if (pqWait(true, true, conn))
970 : {
971 0 : result = -1;
972 0 : break;
973 : }
974 : }
975 : }
976 :
977 : /* shift the remaining contents of the buffer */
978 940272 : if (remaining > 0)
979 4960 : memmove(conn->outBuffer, ptr, remaining);
980 940272 : conn->outCount = remaining;
981 :
982 940272 : return result;
983 : }
984 :
985 :
986 : /*
987 : * pqFlush: send any data waiting in the output buffer
988 : *
989 : * Return 0 on success, -1 on failure and 1 when not all data could be sent
990 : * because the socket would block and the connection is non-blocking.
991 : * (See pqSendSome comments about how failure should be handled.)
992 : */
993 : int
994 1751108 : pqFlush(PGconn *conn)
995 : {
996 1751108 : if (conn->outCount > 0)
997 : {
998 935312 : if (conn->Pfdebug)
999 108 : fflush(conn->Pfdebug);
1000 :
1001 935312 : return pqSendSome(conn, conn->outCount);
1002 : }
1003 :
1004 815796 : return 0;
1005 : }
1006 :
1007 :
1008 : /*
1009 : * pqWait: wait until we can read or write the connection socket
1010 : *
1011 : * JAB: If SSL enabled and used and forRead, buffered bytes short-circuit the
1012 : * call to select().
1013 : *
1014 : * We also stop waiting and return if the kernel flags an exception condition
1015 : * on the socket. The actual error condition will be detected and reported
1016 : * when the caller tries to read or write the socket.
1017 : */
1018 : int
1019 1064458 : pqWait(int forRead, int forWrite, PGconn *conn)
1020 : {
1021 1064458 : return pqWaitTimed(forRead, forWrite, conn, -1);
1022 : }
1023 :
1024 : /*
1025 : * pqWaitTimed: wait, but not past end_time.
1026 : *
1027 : * Returns -1 on failure, 0 if the socket is readable/writable, 1 if it timed out.
1028 : *
1029 : * The timeout is specified by end_time, which is the int64 number of
1030 : * microseconds since the Unix epoch (that is, time_t times 1 million).
1031 : * Timeout is infinite if end_time is -1. Timeout is immediate (no blocking)
1032 : * if end_time is 0 (or indeed, any time before now).
1033 : */
1034 : int
1035 1115008 : pqWaitTimed(int forRead, int forWrite, PGconn *conn, pg_usec_time_t end_time)
1036 : {
1037 : int result;
1038 :
1039 1115008 : result = pqSocketCheck(conn, forRead, forWrite, end_time);
1040 :
1041 1115008 : if (result < 0)
1042 74 : return -1; /* errorMessage is already set */
1043 :
1044 1114934 : if (result == 0)
1045 : {
1046 0 : libpq_append_conn_error(conn, "timeout expired");
1047 0 : return 1;
1048 : }
1049 :
1050 1114934 : return 0;
1051 : }
1052 :
1053 : /*
1054 : * pqReadReady: is select() saying the file is ready to read?
1055 : * Returns -1 on failure, 0 if not ready, 1 if ready.
1056 : */
1057 : int
1058 168 : pqReadReady(PGconn *conn)
1059 : {
1060 168 : return pqSocketCheck(conn, 1, 0, 0);
1061 : }
1062 :
1063 : /*
1064 : * pqWriteReady: is select() saying the file is ready to write?
1065 : * Returns -1 on failure, 0 if not ready, 1 if ready.
1066 : */
1067 : int
1068 0 : pqWriteReady(PGconn *conn)
1069 : {
1070 0 : return pqSocketCheck(conn, 0, 1, 0);
1071 : }
1072 :
1073 : /*
1074 : * Checks a socket, using poll or select, for data to be read, written,
1075 : * or both. Returns >0 if one or more conditions are met, 0 if it timed
1076 : * out, -1 if an error occurred.
1077 : *
1078 : * If an altsock is set for asynchronous authentication, that will be used in
1079 : * preference to the "server" socket. Otherwise, if SSL is in use, the SSL
1080 : * buffer is checked prior to checking the socket for read data directly.
1081 : */
1082 : static int
1083 1115176 : pqSocketCheck(PGconn *conn, int forRead, int forWrite, pg_usec_time_t end_time)
1084 : {
1085 : int result;
1086 : pgsocket sock;
1087 :
1088 1115176 : if (!conn)
1089 0 : return -1;
1090 :
1091 1115176 : if (conn->altsock != PGINVALID_SOCKET)
1092 0 : sock = conn->altsock;
1093 : else
1094 : {
1095 1115176 : sock = conn->sock;
1096 1115176 : if (sock == PGINVALID_SOCKET)
1097 : {
1098 74 : libpq_append_conn_error(conn, "invalid socket");
1099 74 : return -1;
1100 : }
1101 :
1102 : #ifdef USE_SSL
1103 : /* Check for SSL library buffering read bytes */
1104 1115102 : if (forRead && conn->ssl_in_use && pgtls_read_pending(conn))
1105 : {
1106 : /* short-circuit the select */
1107 0 : return 1;
1108 : }
1109 : #endif
1110 : }
1111 :
1112 : /* We will retry as long as we get EINTR */
1113 : do
1114 1115106 : result = PQsocketPoll(sock, forRead, forWrite, end_time);
1115 1115106 : while (result < 0 && SOCK_ERRNO == EINTR);
1116 :
1117 1115102 : if (result < 0)
1118 : {
1119 : char sebuf[PG_STRERROR_R_BUFLEN];
1120 :
1121 0 : libpq_append_conn_error(conn, "%s() failed: %s", "select",
1122 0 : SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
1123 : }
1124 :
1125 1115102 : return result;
1126 : }
1127 :
1128 :
1129 : /*
1130 : * Check a file descriptor for read and/or write data, possibly waiting.
1131 : * If neither forRead nor forWrite are set, immediately return a timeout
1132 : * condition (without waiting). Return >0 if condition is met, 0
1133 : * if a timeout occurred, -1 if an error or interrupt occurred.
1134 : *
1135 : * The timeout is specified by end_time, which is the int64 number of
1136 : * microseconds since the Unix epoch (that is, time_t times 1 million).
1137 : * Timeout is infinite if end_time is -1. Timeout is immediate (no blocking)
1138 : * if end_time is 0 (or indeed, any time before now).
1139 : */
1140 : int
1141 1115810 : PQsocketPoll(int sock, int forRead, int forWrite, pg_usec_time_t end_time)
1142 : {
1143 : /* We use poll(2) if available, otherwise select(2) */
1144 : #ifdef HAVE_POLL
1145 : struct pollfd input_fd;
1146 : int timeout_ms;
1147 :
1148 1115810 : if (!forRead && !forWrite)
1149 0 : return 0;
1150 :
1151 1115810 : input_fd.fd = sock;
1152 1115810 : input_fd.events = POLLERR;
1153 1115810 : input_fd.revents = 0;
1154 :
1155 1115810 : if (forRead)
1156 1090158 : input_fd.events |= POLLIN;
1157 1115810 : if (forWrite)
1158 30122 : input_fd.events |= POLLOUT;
1159 :
1160 : /* Compute appropriate timeout interval */
1161 1115810 : if (end_time == -1)
1162 1114910 : timeout_ms = -1;
1163 900 : else if (end_time == 0)
1164 168 : timeout_ms = 0;
1165 : else
1166 : {
1167 732 : pg_usec_time_t now = PQgetCurrentTimeUSec();
1168 :
1169 732 : if (end_time > now)
1170 732 : timeout_ms = (end_time - now) / 1000;
1171 : else
1172 0 : timeout_ms = 0;
1173 : }
1174 :
1175 1115810 : return poll(&input_fd, 1, timeout_ms);
1176 : #else /* !HAVE_POLL */
1177 :
1178 : fd_set input_mask;
1179 : fd_set output_mask;
1180 : fd_set except_mask;
1181 : struct timeval timeout;
1182 : struct timeval *ptr_timeout;
1183 :
1184 : if (!forRead && !forWrite)
1185 : return 0;
1186 :
1187 : FD_ZERO(&input_mask);
1188 : FD_ZERO(&output_mask);
1189 : FD_ZERO(&except_mask);
1190 : if (forRead)
1191 : FD_SET(sock, &input_mask);
1192 :
1193 : if (forWrite)
1194 : FD_SET(sock, &output_mask);
1195 : FD_SET(sock, &except_mask);
1196 :
1197 : /* Compute appropriate timeout interval */
1198 : if (end_time == -1)
1199 : ptr_timeout = NULL;
1200 : else if (end_time == 0)
1201 : {
1202 : timeout.tv_sec = 0;
1203 : timeout.tv_usec = 0;
1204 : ptr_timeout = &timeout;
1205 : }
1206 : else
1207 : {
1208 : pg_usec_time_t now = PQgetCurrentTimeUSec();
1209 :
1210 : if (end_time > now)
1211 : {
1212 : timeout.tv_sec = (end_time - now) / 1000000;
1213 : timeout.tv_usec = (end_time - now) % 1000000;
1214 : }
1215 : else
1216 : {
1217 : timeout.tv_sec = 0;
1218 : timeout.tv_usec = 0;
1219 : }
1220 : ptr_timeout = &timeout;
1221 : }
1222 :
1223 : return select(sock + 1, &input_mask, &output_mask,
1224 : &except_mask, ptr_timeout);
1225 : #endif /* HAVE_POLL */
1226 : }
1227 :
1228 : /*
1229 : * PQgetCurrentTimeUSec: get current time with microsecond precision
1230 : *
1231 : * This provides a platform-independent way of producing a reference
1232 : * value for PQsocketPoll's timeout parameter.
1233 : */
1234 : pg_usec_time_t
1235 1444 : PQgetCurrentTimeUSec(void)
1236 : {
1237 : struct timeval tval;
1238 :
1239 1444 : gettimeofday(&tval, NULL);
1240 1444 : return (pg_usec_time_t) tval.tv_sec * 1000000 + tval.tv_usec;
1241 : }
1242 :
1243 :
1244 : /*
1245 : * A couple of "miscellaneous" multibyte related functions. They used
1246 : * to be in fe-print.c but that file is doomed.
1247 : */
1248 :
1249 : /*
1250 : * Like pg_encoding_mblen(). Use this in callers that want the
1251 : * dynamically-linked libpq's stance on encodings, even if that means
1252 : * different behavior in different startups of the executable.
1253 : */
1254 : int
1255 53585666 : PQmblen(const char *s, int encoding)
1256 : {
1257 53585666 : return pg_encoding_mblen(encoding, s);
1258 : }
1259 :
1260 : /*
1261 : * Like pg_encoding_mblen_bounded(). Use this in callers that want the
1262 : * dynamically-linked libpq's stance on encodings, even if that means
1263 : * different behavior in different startups of the executable.
1264 : */
1265 : int
1266 781794 : PQmblenBounded(const char *s, int encoding)
1267 : {
1268 781794 : return strnlen(s, pg_encoding_mblen(encoding, s));
1269 : }
1270 :
1271 : /*
1272 : * Returns the display length of the character beginning at s, using the
1273 : * specified encoding.
1274 : */
1275 : int
1276 53585442 : PQdsplen(const char *s, int encoding)
1277 : {
1278 53585442 : return pg_encoding_dsplen(encoding, s);
1279 : }
1280 :
1281 : /*
1282 : * Get encoding id from environment variable PGCLIENTENCODING.
1283 : */
1284 : int
1285 17810 : PQenv2encoding(void)
1286 : {
1287 : char *str;
1288 17810 : int encoding = PG_SQL_ASCII;
1289 :
1290 17810 : str = getenv("PGCLIENTENCODING");
1291 17810 : if (str && *str != '\0')
1292 : {
1293 12 : encoding = pg_char_to_encoding(str);
1294 12 : if (encoding < 0)
1295 0 : encoding = PG_SQL_ASCII;
1296 : }
1297 17810 : return encoding;
1298 : }
1299 :
1300 :
1301 : #ifdef ENABLE_NLS
1302 :
1303 : static void
1304 187048 : libpq_binddomain(void)
1305 : {
1306 : /*
1307 : * At least on Windows, there are gettext implementations that fail if
1308 : * multiple threads call bindtextdomain() concurrently. Use a mutex and
1309 : * flag variable to ensure that we call it just once per process. It is
1310 : * not known that similar bugs exist on non-Windows platforms, but we
1311 : * might as well do it the same way everywhere.
1312 : */
1313 : static volatile bool already_bound = false;
1314 : static pthread_mutex_t binddomain_mutex = PTHREAD_MUTEX_INITIALIZER;
1315 :
1316 187048 : if (!already_bound)
1317 : {
1318 : /* bindtextdomain() does not preserve errno */
1319 : #ifdef WIN32
1320 : int save_errno = GetLastError();
1321 : #else
1322 22424 : int save_errno = errno;
1323 : #endif
1324 :
1325 22424 : (void) pthread_mutex_lock(&binddomain_mutex);
1326 :
1327 22424 : if (!already_bound)
1328 : {
1329 : const char *ldir;
1330 :
1331 : /*
1332 : * No relocatable lookup here because the calling executable could
1333 : * be anywhere
1334 : */
1335 22424 : ldir = getenv("PGLOCALEDIR");
1336 22424 : if (!ldir)
1337 244 : ldir = LOCALEDIR;
1338 22424 : bindtextdomain(PG_TEXTDOMAIN("libpq"), ldir);
1339 22424 : already_bound = true;
1340 : }
1341 :
1342 22424 : (void) pthread_mutex_unlock(&binddomain_mutex);
1343 :
1344 : #ifdef WIN32
1345 : SetLastError(save_errno);
1346 : #else
1347 22424 : errno = save_errno;
1348 : #endif
1349 : }
1350 187048 : }
1351 :
1352 : char *
1353 187034 : libpq_gettext(const char *msgid)
1354 : {
1355 187034 : libpq_binddomain();
1356 187034 : return dgettext(PG_TEXTDOMAIN("libpq"), msgid);
1357 : }
1358 :
1359 : char *
1360 14 : libpq_ngettext(const char *msgid, const char *msgid_plural, unsigned long n)
1361 : {
1362 14 : libpq_binddomain();
1363 14 : return dngettext(PG_TEXTDOMAIN("libpq"), msgid, msgid_plural, n);
1364 : }
1365 :
1366 : #endif /* ENABLE_NLS */
1367 :
1368 :
1369 : /*
1370 : * Append a formatted string to the given buffer, after translating it. A
1371 : * newline is automatically appended; the format should not end with a
1372 : * newline.
1373 : */
1374 : void
1375 64 : libpq_append_error(PQExpBuffer errorMessage, const char *fmt,...)
1376 : {
1377 64 : int save_errno = errno;
1378 : bool done;
1379 : va_list args;
1380 :
1381 : Assert(fmt[strlen(fmt) - 1] != '\n');
1382 :
1383 64 : if (PQExpBufferBroken(errorMessage))
1384 0 : return; /* already failed */
1385 :
1386 : /* Loop in case we have to retry after enlarging the buffer. */
1387 : do
1388 : {
1389 64 : errno = save_errno;
1390 64 : va_start(args, fmt);
1391 64 : done = appendPQExpBufferVA(errorMessage, libpq_gettext(fmt), args);
1392 64 : va_end(args);
1393 64 : } while (!done);
1394 :
1395 64 : appendPQExpBufferChar(errorMessage, '\n');
1396 : }
1397 :
1398 : /*
1399 : * Append a formatted string to the error message buffer of the given
1400 : * connection, after translating it. A newline is automatically appended; the
1401 : * format should not end with a newline.
1402 : */
1403 : void
1404 1272 : libpq_append_conn_error(PGconn *conn, const char *fmt,...)
1405 : {
1406 1272 : int save_errno = errno;
1407 : bool done;
1408 : va_list args;
1409 :
1410 : Assert(fmt[strlen(fmt) - 1] != '\n');
1411 :
1412 1272 : if (PQExpBufferBroken(&conn->errorMessage))
1413 0 : return; /* already failed */
1414 :
1415 : /* Loop in case we have to retry after enlarging the buffer. */
1416 : do
1417 : {
1418 1282 : errno = save_errno;
1419 1282 : va_start(args, fmt);
1420 1282 : done = appendPQExpBufferVA(&conn->errorMessage, libpq_gettext(fmt), args);
1421 1282 : va_end(args);
1422 1282 : } while (!done);
1423 :
1424 1272 : appendPQExpBufferChar(&conn->errorMessage, '\n');
1425 : }
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