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) 1996-2024, 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 : 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: get 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 17740386 : pqGetc(char *result, PGconn *conn)
78 : {
79 17740386 : if (conn->inCursor >= conn->inEnd)
80 2983270 : return EOF;
81 :
82 14757116 : *result = conn->inBuffer[conn->inCursor++];
83 :
84 14757116 : return 0;
85 : }
86 :
87 :
88 : /*
89 : * pqPutc: write 1 char to the current message
90 : */
91 : int
92 20310 : pqPutc(char c, PGconn *conn)
93 : {
94 20310 : if (pqPutMsgBytes(&c, 1, conn))
95 0 : return EOF;
96 :
97 20310 : return 0;
98 : }
99 :
100 :
101 : /*
102 : * pqGets[_append]:
103 : * get 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 2507822 : pqGets_internal(PQExpBuffer buf, PGconn *conn, bool resetbuffer)
110 : {
111 : /* Copy conn data to locals for faster search loop */
112 2507822 : char *inBuffer = conn->inBuffer;
113 2507822 : int inCursor = conn->inCursor;
114 2507822 : int inEnd = conn->inEnd;
115 : int slen;
116 :
117 30740740 : while (inCursor < inEnd && inBuffer[inCursor])
118 28232918 : inCursor++;
119 :
120 2507822 : if (inCursor >= inEnd)
121 0 : return EOF;
122 :
123 2507822 : slen = inCursor - conn->inCursor;
124 :
125 2507822 : if (resetbuffer)
126 2507822 : resetPQExpBuffer(buf);
127 :
128 2507822 : appendBinaryPQExpBuffer(buf, inBuffer + conn->inCursor, slen);
129 :
130 2507822 : conn->inCursor = ++inCursor;
131 :
132 2507822 : return 0;
133 : }
134 :
135 : int
136 2507822 : pqGets(PQExpBuffer buf, PGconn *conn)
137 : {
138 2507822 : 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 640280 : pqPuts(const char *s, PGconn *conn)
153 : {
154 640280 : if (pqPutMsgBytes(s, strlen(s) + 1, conn))
155 0 : return EOF;
156 :
157 640280 : return 0;
158 : }
159 :
160 : /*
161 : * pqGetnchar:
162 : * get a string of exactly len bytes in buffer s, no null termination
163 : */
164 : int
165 874 : pqGetnchar(char *s, size_t len, PGconn *conn)
166 : {
167 874 : if (len > (size_t) (conn->inEnd - conn->inCursor))
168 0 : return EOF;
169 :
170 874 : memcpy(s, conn->inBuffer + conn->inCursor, len);
171 : /* no terminating null */
172 :
173 874 : conn->inCursor += len;
174 :
175 874 : 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 27527180 : pqSkipnchar(size_t len, PGconn *conn)
188 : {
189 27527180 : if (len > (size_t) (conn->inEnd - conn->inCursor))
190 0 : return EOF;
191 :
192 27527180 : conn->inCursor += len;
193 :
194 27527180 : return 0;
195 : }
196 :
197 : /*
198 : * pqPutnchar:
199 : * write exactly len bytes to the current message
200 : */
201 : int
202 623142 : pqPutnchar(const char *s, size_t len, PGconn *conn)
203 : {
204 623142 : if (pqPutMsgBytes(s, len, conn))
205 0 : return EOF;
206 :
207 623142 : 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 54583036 : pqGetInt(int *result, size_t bytes, PGconn *conn)
217 : {
218 : uint16 tmp2;
219 : uint32 tmp4;
220 :
221 54583036 : switch (bytes)
222 : {
223 9153350 : case 2:
224 9153350 : if (conn->inCursor + 2 > conn->inEnd)
225 0 : return EOF;
226 9153350 : memcpy(&tmp2, conn->inBuffer + conn->inCursor, 2);
227 9153350 : conn->inCursor += 2;
228 9153350 : *result = (int) pg_ntoh16(tmp2);
229 9153350 : break;
230 45429686 : case 4:
231 45429686 : if (conn->inCursor + 4 > conn->inEnd)
232 3948 : return EOF;
233 45425738 : memcpy(&tmp4, conn->inBuffer + conn->inCursor, 4);
234 45425738 : conn->inCursor += 4;
235 45425738 : *result = (int) pg_ntoh32(tmp4);
236 45425738 : 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 54579088 : 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 163346 : pqPutInt(int value, size_t bytes, PGconn *conn)
254 : {
255 : uint16 tmp2;
256 : uint32 tmp4;
257 :
258 163346 : switch (bytes)
259 : {
260 105982 : case 2:
261 105982 : tmp2 = pg_hton16((uint16) value);
262 105982 : if (pqPutMsgBytes((const char *) &tmp2, 2, conn))
263 0 : return EOF;
264 105982 : break;
265 57364 : case 4:
266 57364 : tmp4 = pg_hton32((uint32) value);
267 57364 : if (pqPutMsgBytes((const char *) &tmp4, 4, conn))
268 0 : return EOF;
269 57364 : 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 163346 : 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 2698312 : pqCheckOutBufferSpace(size_t bytes_needed, PGconn *conn)
288 : {
289 2698312 : int newsize = conn->outBufSize;
290 : char *newbuf;
291 :
292 : /* Quick exit if we have enough space */
293 2698312 : if (bytes_needed <= (size_t) newsize)
294 2698274 : 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 98 : newsize *= 2;
306 98 : } while (newsize > 0 && bytes_needed > (size_t) newsize);
307 :
308 38 : if (newsize > 0 && bytes_needed <= (size_t) newsize)
309 : {
310 38 : newbuf = realloc(conn->outBuffer, newsize);
311 38 : if (newbuf)
312 : {
313 : /* realloc succeeded */
314 38 : conn->outBuffer = newbuf;
315 38 : conn->outBufSize = newsize;
316 38 : 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 231058 : pqCheckInBufferSpace(size_t bytes_needed, PGconn *conn)
352 : {
353 231058 : int newsize = conn->inBufSize;
354 : char *newbuf;
355 :
356 : /* Quick exit if we have enough space */
357 231058 : if (bytes_needed <= (size_t) newsize)
358 102372 : 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 128686 : bytes_needed -= conn->inStart;
368 :
369 128686 : if (conn->inStart < conn->inEnd)
370 : {
371 128686 : if (conn->inStart > 0)
372 : {
373 128188 : memmove(conn->inBuffer, conn->inBuffer + conn->inStart,
374 128188 : conn->inEnd - conn->inStart);
375 128188 : conn->inEnd -= conn->inStart;
376 128188 : conn->inCursor -= conn->inStart;
377 128188 : 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 128686 : if (bytes_needed <= (size_t) newsize)
388 127436 : 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 2250 : newsize *= 2;
400 2250 : } while (newsize > 0 && bytes_needed > (size_t) newsize);
401 :
402 1250 : if (newsize > 0 && bytes_needed <= (size_t) newsize)
403 : {
404 1250 : newbuf = realloc(conn->inBuffer, newsize);
405 1250 : if (newbuf)
406 : {
407 : /* realloc succeeded */
408 1250 : conn->inBuffer = newbuf;
409 1250 : conn->inBufSize = newsize;
410 1250 : 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 : * pqPutMsgStart: begin construction of a message to the server
440 : *
441 : * msg_type is the message type byte, or 0 for a message without type byte
442 : * (only startup messages have no type byte)
443 : *
444 : * Returns 0 on success, EOF on error
445 : *
446 : * The idea here is that we construct the message in conn->outBuffer,
447 : * beginning just past any data already in outBuffer (ie, at
448 : * outBuffer+outCount). We enlarge the buffer as needed to hold the message.
449 : * When the message is complete, we fill in the length word (if needed) and
450 : * then advance outCount past the message, making it eligible to send.
451 : *
452 : * The state variable conn->outMsgStart points to the incomplete message's
453 : * length word: it is either outCount or outCount+1 depending on whether
454 : * there is a type byte. The state variable conn->outMsgEnd is the end of
455 : * the data collected so far.
456 : */
457 : int
458 1251204 : pqPutMsgStart(char msg_type, PGconn *conn)
459 : {
460 : int lenPos;
461 : int endPos;
462 :
463 : /* allow room for message type byte */
464 1251204 : if (msg_type)
465 1228542 : endPos = conn->outCount + 1;
466 : else
467 22662 : endPos = conn->outCount;
468 :
469 : /* do we want a length word? */
470 1251204 : lenPos = endPos;
471 : /* allow room for message length */
472 1251204 : endPos += 4;
473 :
474 : /* make sure there is room for message header */
475 1251204 : if (pqCheckOutBufferSpace(endPos, conn))
476 0 : return EOF;
477 : /* okay, save the message type byte if any */
478 1251204 : if (msg_type)
479 1228542 : conn->outBuffer[conn->outCount] = msg_type;
480 : /* set up the message pointers */
481 1251204 : conn->outMsgStart = lenPos;
482 1251204 : conn->outMsgEnd = endPos;
483 : /* length word, if needed, will be filled in by pqPutMsgEnd */
484 :
485 1251204 : return 0;
486 : }
487 :
488 : /*
489 : * pqPutMsgBytes: add bytes to a partially-constructed message
490 : *
491 : * Returns 0 on success, EOF on error
492 : */
493 : static int
494 1447078 : pqPutMsgBytes(const void *buf, size_t len, PGconn *conn)
495 : {
496 : /* make sure there is room for it */
497 1447078 : if (pqCheckOutBufferSpace(conn->outMsgEnd + len, conn))
498 0 : return EOF;
499 : /* okay, save the data */
500 1447078 : memcpy(conn->outBuffer + conn->outMsgEnd, buf, len);
501 1447078 : conn->outMsgEnd += len;
502 : /* no Pfdebug call here, caller should do it */
503 1447078 : return 0;
504 : }
505 :
506 : /*
507 : * pqPutMsgEnd: finish constructing a message and possibly send it
508 : *
509 : * Returns 0 on success, EOF on error
510 : *
511 : * We don't actually send anything here unless we've accumulated at least
512 : * 8K worth of data (the typical size of a pipe buffer on Unix systems).
513 : * This avoids sending small partial packets. The caller must use pqFlush
514 : * when it's important to flush all the data out to the server.
515 : */
516 : int
517 1251204 : pqPutMsgEnd(PGconn *conn)
518 : {
519 : /* Fill in length word if needed */
520 1251204 : if (conn->outMsgStart >= 0)
521 : {
522 1251204 : uint32 msgLen = conn->outMsgEnd - conn->outMsgStart;
523 :
524 1251204 : msgLen = pg_hton32(msgLen);
525 1251204 : memcpy(conn->outBuffer + conn->outMsgStart, &msgLen, 4);
526 : }
527 :
528 : /* trace client-to-server message */
529 1251204 : if (conn->Pfdebug)
530 : {
531 394 : if (conn->outCount < conn->outMsgStart)
532 394 : pqTraceOutputMessage(conn, conn->outBuffer + conn->outCount, true);
533 : else
534 0 : pqTraceOutputNoTypeByteMessage(conn,
535 0 : conn->outBuffer + conn->outMsgStart);
536 : }
537 :
538 : /* Make message eligible to send */
539 1251204 : conn->outCount = conn->outMsgEnd;
540 :
541 1251204 : if (conn->outCount >= 8192)
542 : {
543 2010 : int toSend = conn->outCount - (conn->outCount % 8192);
544 :
545 2010 : if (pqSendSome(conn, toSend) < 0)
546 0 : return EOF;
547 : /* in nonblock mode, don't complain if unable to send it all */
548 : }
549 :
550 1251204 : return 0;
551 : }
552 :
553 : /* ----------
554 : * pqReadData: read more data, if any is available
555 : * Possible return values:
556 : * 1: successfully loaded at least one more byte
557 : * 0: no data is presently available, but no error detected
558 : * -1: error detected (including EOF = connection closure);
559 : * conn->errorMessage set
560 : * NOTE: callers must not assume that pointers or indexes into conn->inBuffer
561 : * remain valid across this call!
562 : * ----------
563 : */
564 : int
565 1668120 : pqReadData(PGconn *conn)
566 : {
567 1668120 : int someread = 0;
568 : int nread;
569 :
570 1668120 : if (conn->sock == PGINVALID_SOCKET)
571 : {
572 4 : libpq_append_conn_error(conn, "connection not open");
573 4 : return -1;
574 : }
575 :
576 : /* Left-justify any data in the buffer to make room */
577 1668116 : if (conn->inStart < conn->inEnd)
578 : {
579 227186 : if (conn->inStart > 0)
580 : {
581 79328 : memmove(conn->inBuffer, conn->inBuffer + conn->inStart,
582 79328 : conn->inEnd - conn->inStart);
583 79328 : conn->inEnd -= conn->inStart;
584 79328 : conn->inCursor -= conn->inStart;
585 79328 : conn->inStart = 0;
586 : }
587 : }
588 : else
589 : {
590 : /* buffer is logically empty, reset it */
591 1440930 : conn->inStart = conn->inCursor = conn->inEnd = 0;
592 : }
593 :
594 : /*
595 : * If the buffer is fairly full, enlarge it. We need to be able to enlarge
596 : * the buffer in case a single message exceeds the initial buffer size. We
597 : * enlarge before filling the buffer entirely so as to avoid asking the
598 : * kernel for a partial packet. The magic constant here should be large
599 : * enough for a TCP packet or Unix pipe bufferload. 8K is the usual pipe
600 : * buffer size, so...
601 : */
602 1668116 : if (conn->inBufSize - conn->inEnd < 8192)
603 : {
604 2 : if (pqCheckInBufferSpace(conn->inEnd + (size_t) 8192, conn))
605 : {
606 : /*
607 : * We don't insist that the enlarge worked, but we need some room
608 : */
609 0 : if (conn->inBufSize - conn->inEnd < 100)
610 0 : return -1; /* errorMessage already set */
611 : }
612 : }
613 :
614 : /* OK, try to read some data */
615 1668116 : retry3:
616 3413424 : nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
617 1706712 : conn->inBufSize - conn->inEnd);
618 1706712 : if (nread < 0)
619 : {
620 566328 : switch (SOCK_ERRNO)
621 : {
622 0 : case EINTR:
623 0 : goto retry3;
624 :
625 : /* Some systems return EAGAIN/EWOULDBLOCK for no data */
626 : #ifdef EAGAIN
627 566316 : case EAGAIN:
628 566316 : return someread;
629 : #endif
630 : #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
631 : case EWOULDBLOCK:
632 : return someread;
633 : #endif
634 :
635 : /* We might get ECONNRESET etc here if connection failed */
636 12 : case ALL_CONNECTION_FAILURE_ERRNOS:
637 12 : goto definitelyFailed;
638 :
639 0 : default:
640 : /* pqsecure_read set the error message for us */
641 0 : return -1;
642 : }
643 : }
644 1140384 : if (nread > 0)
645 : {
646 1139830 : conn->inEnd += nread;
647 :
648 : /*
649 : * Hack to deal with the fact that some kernels will only give us back
650 : * 1 packet per recv() call, even if we asked for more and there is
651 : * more available. If it looks like we are reading a long message,
652 : * loop back to recv() again immediately, until we run out of data or
653 : * buffer space. Without this, the block-and-restart behavior of
654 : * libpq's higher levels leads to O(N^2) performance on long messages.
655 : *
656 : * Since we left-justified the data above, conn->inEnd gives the
657 : * amount of data already read in the current message. We consider
658 : * the message "long" once we have acquired 32k ...
659 : */
660 1139830 : if (conn->inEnd > 32768 &&
661 153238 : (conn->inBufSize - conn->inEnd) >= 8192)
662 : {
663 38596 : someread = 1;
664 38596 : goto retry3;
665 : }
666 1101234 : return 1;
667 : }
668 :
669 554 : if (someread)
670 0 : return 1; /* got a zero read after successful tries */
671 :
672 : /*
673 : * A return value of 0 could mean just that no data is now available, or
674 : * it could mean EOF --- that is, the server has closed the connection.
675 : * Since we have the socket in nonblock mode, the only way to tell the
676 : * difference is to see if select() is saying that the file is ready.
677 : * Grumble. Fortunately, we don't expect this path to be taken much,
678 : * since in normal practice we should not be trying to read data unless
679 : * the file selected for reading already.
680 : *
681 : * In SSL mode it's even worse: SSL_read() could say WANT_READ and then
682 : * data could arrive before we make the pqReadReady() test, but the second
683 : * SSL_read() could still say WANT_READ because the data received was not
684 : * a complete SSL record. So we must play dumb and assume there is more
685 : * data, relying on the SSL layer to detect true EOF.
686 : */
687 :
688 : #ifdef USE_SSL
689 554 : if (conn->ssl_in_use)
690 368 : return 0;
691 : #endif
692 :
693 186 : switch (pqReadReady(conn))
694 : {
695 0 : case 0:
696 : /* definitely no data available */
697 0 : return 0;
698 186 : case 1:
699 : /* ready for read */
700 186 : break;
701 0 : default:
702 : /* we override pqReadReady's message with something more useful */
703 0 : goto definitelyEOF;
704 : }
705 :
706 : /*
707 : * Still not sure that it's EOF, because some data could have just
708 : * arrived.
709 : */
710 186 : retry4:
711 372 : nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
712 186 : conn->inBufSize - conn->inEnd);
713 186 : if (nread < 0)
714 : {
715 0 : switch (SOCK_ERRNO)
716 : {
717 0 : case EINTR:
718 0 : goto retry4;
719 :
720 : /* Some systems return EAGAIN/EWOULDBLOCK for no data */
721 : #ifdef EAGAIN
722 0 : case EAGAIN:
723 0 : return 0;
724 : #endif
725 : #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
726 : case EWOULDBLOCK:
727 : return 0;
728 : #endif
729 :
730 : /* We might get ECONNRESET etc here if connection failed */
731 0 : case ALL_CONNECTION_FAILURE_ERRNOS:
732 0 : goto definitelyFailed;
733 :
734 0 : default:
735 : /* pqsecure_read set the error message for us */
736 0 : return -1;
737 : }
738 : }
739 186 : if (nread > 0)
740 : {
741 0 : conn->inEnd += nread;
742 0 : return 1;
743 : }
744 :
745 : /*
746 : * OK, we are getting a zero read even though select() says ready. This
747 : * means the connection has been closed. Cope.
748 : */
749 186 : definitelyEOF:
750 186 : libpq_append_conn_error(conn, "server closed the connection unexpectedly\n"
751 : "\tThis probably means the server terminated abnormally\n"
752 : "\tbefore or while processing the request.");
753 :
754 : /* Come here if lower-level code already set a suitable errorMessage */
755 198 : definitelyFailed:
756 : /* Do *not* drop any already-read data; caller still wants it */
757 198 : pqDropConnection(conn, false);
758 198 : conn->status = CONNECTION_BAD; /* No more connection to backend */
759 198 : return -1;
760 : }
761 :
762 : /*
763 : * pqSendSome: send data waiting in the output buffer.
764 : *
765 : * len is how much to try to send (typically equal to outCount, but may
766 : * be less).
767 : *
768 : * Return 0 on success, -1 on failure and 1 when not all data could be sent
769 : * because the socket would block and the connection is non-blocking.
770 : *
771 : * Note that this is also responsible for consuming data from the socket
772 : * (putting it in conn->inBuffer) in any situation where we can't send
773 : * all the specified data immediately.
774 : *
775 : * If a socket-level write failure occurs, conn->write_failed is set and the
776 : * error message is saved in conn->write_err_msg, but we clear the output
777 : * buffer and return zero anyway; this is because callers should soldier on
778 : * until we have read what we can from the server and checked for an error
779 : * message. write_err_msg should be reported only when we are unable to
780 : * obtain a server error first. Much of that behavior is implemented at
781 : * lower levels, but this function deals with some edge cases.
782 : */
783 : static int
784 783936 : pqSendSome(PGconn *conn, int len)
785 : {
786 783936 : char *ptr = conn->outBuffer;
787 783936 : int remaining = conn->outCount;
788 783936 : int result = 0;
789 :
790 : /*
791 : * If we already had a write failure, we will never again try to send data
792 : * on that connection. Even if the kernel would let us, we've probably
793 : * lost message boundary sync with the server. conn->write_failed
794 : * therefore persists until the connection is reset, and we just discard
795 : * all data presented to be written. However, as long as we still have a
796 : * valid socket, we should continue to absorb data from the backend, so
797 : * that we can collect any final error messages.
798 : */
799 783936 : if (conn->write_failed)
800 : {
801 : /* conn->write_err_msg should be set up already */
802 0 : conn->outCount = 0;
803 : /* Absorb input data if any, and detect socket closure */
804 0 : if (conn->sock != PGINVALID_SOCKET)
805 : {
806 0 : if (pqReadData(conn) < 0)
807 0 : return -1;
808 : }
809 0 : return 0;
810 : }
811 :
812 783936 : if (conn->sock == PGINVALID_SOCKET)
813 : {
814 0 : conn->write_failed = true;
815 : /* Store error message in conn->write_err_msg, if possible */
816 : /* (strdup failure is OK, we'll cope later) */
817 0 : conn->write_err_msg = strdup(libpq_gettext("connection not open\n"));
818 : /* Discard queued data; no chance it'll ever be sent */
819 0 : conn->outCount = 0;
820 0 : return 0;
821 : }
822 :
823 : /* while there's still data to send */
824 1567902 : while (len > 0)
825 : {
826 : int sent;
827 :
828 : #ifndef WIN32
829 783972 : sent = pqsecure_write(conn, ptr, len);
830 : #else
831 :
832 : /*
833 : * Windows can fail on large sends, per KB article Q201213. The
834 : * failure-point appears to be different in different versions of
835 : * Windows, but 64k should always be safe.
836 : */
837 : sent = pqsecure_write(conn, ptr, Min(len, 65536));
838 : #endif
839 :
840 783972 : if (sent < 0)
841 : {
842 : /* Anything except EAGAIN/EWOULDBLOCK/EINTR is trouble */
843 42 : switch (SOCK_ERRNO)
844 : {
845 : #ifdef EAGAIN
846 42 : case EAGAIN:
847 42 : break;
848 : #endif
849 : #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
850 : case EWOULDBLOCK:
851 : break;
852 : #endif
853 0 : case EINTR:
854 0 : continue;
855 :
856 0 : default:
857 : /* Discard queued data; no chance it'll ever be sent */
858 0 : conn->outCount = 0;
859 :
860 : /* Absorb input data if any, and detect socket closure */
861 0 : if (conn->sock != PGINVALID_SOCKET)
862 : {
863 0 : if (pqReadData(conn) < 0)
864 0 : return -1;
865 : }
866 :
867 : /*
868 : * Lower-level code should already have filled
869 : * conn->write_err_msg (and set conn->write_failed) or
870 : * conn->errorMessage. In the former case, we pretend
871 : * there's no problem; the write_failed condition will be
872 : * dealt with later. Otherwise, report the error now.
873 : */
874 0 : if (conn->write_failed)
875 0 : return 0;
876 : else
877 0 : return -1;
878 : }
879 : }
880 : else
881 : {
882 783930 : ptr += sent;
883 783930 : len -= sent;
884 783930 : remaining -= sent;
885 : }
886 :
887 783972 : if (len > 0)
888 : {
889 : /*
890 : * We didn't send it all, wait till we can send more.
891 : *
892 : * There are scenarios in which we can't send data because the
893 : * communications channel is full, but we cannot expect the server
894 : * to clear the channel eventually because it's blocked trying to
895 : * send data to us. (This can happen when we are sending a large
896 : * amount of COPY data, and the server has generated lots of
897 : * NOTICE responses.) To avoid a deadlock situation, we must be
898 : * prepared to accept and buffer incoming data before we try
899 : * again. Furthermore, it is possible that such incoming data
900 : * might not arrive until after we've gone to sleep. Therefore,
901 : * we wait for either read ready or write ready.
902 : *
903 : * In non-blocking mode, we don't wait here directly, but return 1
904 : * to indicate that data is still pending. The caller should wait
905 : * for both read and write ready conditions, and call
906 : * PQconsumeInput() on read ready, but just in case it doesn't, we
907 : * call pqReadData() ourselves before returning. That's not
908 : * enough if the data has not arrived yet, but it's the best we
909 : * can do, and works pretty well in practice. (The documentation
910 : * used to say that you only need to wait for write-ready, so
911 : * there are still plenty of applications like that out there.)
912 : *
913 : * Note that errors here don't result in write_failed becoming
914 : * set.
915 : */
916 42 : if (pqReadData(conn) < 0)
917 : {
918 0 : result = -1; /* error message already set up */
919 0 : break;
920 : }
921 :
922 42 : if (pqIsnonblocking(conn))
923 : {
924 6 : result = 1;
925 6 : break;
926 : }
927 :
928 36 : if (pqWait(true, true, conn))
929 : {
930 0 : result = -1;
931 0 : break;
932 : }
933 : }
934 : }
935 :
936 : /* shift the remaining contents of the buffer */
937 783936 : if (remaining > 0)
938 2010 : memmove(conn->outBuffer, ptr, remaining);
939 783936 : conn->outCount = remaining;
940 :
941 783936 : return result;
942 : }
943 :
944 :
945 : /*
946 : * pqFlush: send any data waiting in the output buffer
947 : *
948 : * Return 0 on success, -1 on failure and 1 when not all data could be sent
949 : * because the socket would block and the connection is non-blocking.
950 : * (See pqSendSome comments about how failure should be handled.)
951 : */
952 : int
953 1413694 : pqFlush(PGconn *conn)
954 : {
955 1413694 : if (conn->outCount > 0)
956 : {
957 781926 : if (conn->Pfdebug)
958 108 : fflush(conn->Pfdebug);
959 :
960 781926 : return pqSendSome(conn, conn->outCount);
961 : }
962 :
963 631768 : return 0;
964 : }
965 :
966 :
967 : /*
968 : * pqWait: wait until we can read or write the connection socket
969 : *
970 : * JAB: If SSL enabled and used and forRead, buffered bytes short-circuit the
971 : * call to select().
972 : *
973 : * We also stop waiting and return if the kernel flags an exception condition
974 : * on the socket. The actual error condition will be detected and reported
975 : * when the caller tries to read or write the socket.
976 : */
977 : int
978 790210 : pqWait(int forRead, int forWrite, PGconn *conn)
979 : {
980 790210 : return pqWaitTimed(forRead, forWrite, conn, (time_t) -1);
981 : }
982 :
983 : /*
984 : * pqWaitTimed: wait, but not past finish_time.
985 : *
986 : * finish_time = ((time_t) -1) disables the wait limit.
987 : *
988 : * Returns -1 on failure, 0 if the socket is readable/writable, 1 if it timed out.
989 : */
990 : int
991 833390 : pqWaitTimed(int forRead, int forWrite, PGconn *conn, time_t finish_time)
992 : {
993 : int result;
994 :
995 833390 : result = pqSocketCheck(conn, forRead, forWrite, finish_time);
996 :
997 833390 : if (result < 0)
998 4 : return -1; /* errorMessage is already set */
999 :
1000 833386 : if (result == 0)
1001 : {
1002 0 : libpq_append_conn_error(conn, "timeout expired");
1003 0 : return 1;
1004 : }
1005 :
1006 833386 : return 0;
1007 : }
1008 :
1009 : /*
1010 : * pqReadReady: is select() saying the file is ready to read?
1011 : * Returns -1 on failure, 0 if not ready, 1 if ready.
1012 : */
1013 : int
1014 186 : pqReadReady(PGconn *conn)
1015 : {
1016 186 : return pqSocketCheck(conn, 1, 0, (time_t) 0);
1017 : }
1018 :
1019 : /*
1020 : * pqWriteReady: is select() saying the file is ready to write?
1021 : * Returns -1 on failure, 0 if not ready, 1 if ready.
1022 : */
1023 : int
1024 0 : pqWriteReady(PGconn *conn)
1025 : {
1026 0 : return pqSocketCheck(conn, 0, 1, (time_t) 0);
1027 : }
1028 :
1029 : /*
1030 : * Checks a socket, using poll or select, for data to be read, written,
1031 : * or both. Returns >0 if one or more conditions are met, 0 if it timed
1032 : * out, -1 if an error occurred.
1033 : *
1034 : * If SSL is in use, the SSL buffer is checked prior to checking the socket
1035 : * for read data directly.
1036 : */
1037 : static int
1038 833576 : pqSocketCheck(PGconn *conn, int forRead, int forWrite, time_t end_time)
1039 : {
1040 : int result;
1041 :
1042 833576 : if (!conn)
1043 0 : return -1;
1044 833576 : if (conn->sock == PGINVALID_SOCKET)
1045 : {
1046 4 : libpq_append_conn_error(conn, "invalid socket");
1047 4 : return -1;
1048 : }
1049 :
1050 : #ifdef USE_SSL
1051 : /* Check for SSL library buffering read bytes */
1052 833572 : if (forRead && conn->ssl_in_use && pgtls_read_pending(conn))
1053 : {
1054 : /* short-circuit the select */
1055 0 : return 1;
1056 : }
1057 : #endif
1058 :
1059 : /* We will retry as long as we get EINTR */
1060 : do
1061 833576 : result = PQsocketPoll(conn->sock, forRead, forWrite, end_time);
1062 833576 : while (result < 0 && SOCK_ERRNO == EINTR);
1063 :
1064 833572 : if (result < 0)
1065 : {
1066 : char sebuf[PG_STRERROR_R_BUFLEN];
1067 :
1068 0 : libpq_append_conn_error(conn, "%s() failed: %s", "select",
1069 0 : SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
1070 : }
1071 :
1072 833572 : return result;
1073 : }
1074 :
1075 :
1076 : /*
1077 : * Check a file descriptor for read and/or write data, possibly waiting.
1078 : * If neither forRead nor forWrite are set, immediately return a timeout
1079 : * condition (without waiting). Return >0 if condition is met, 0
1080 : * if a timeout occurred, -1 if an error or interrupt occurred.
1081 : *
1082 : * Timeout is infinite if end_time is -1. Timeout is immediate (no blocking)
1083 : * if end_time is 0 (or indeed, any time before now).
1084 : */
1085 : int
1086 834180 : PQsocketPoll(int sock, int forRead, int forWrite, time_t end_time)
1087 : {
1088 : /* We use poll(2) if available, otherwise select(2) */
1089 : #ifdef HAVE_POLL
1090 : struct pollfd input_fd;
1091 : int timeout_ms;
1092 :
1093 834180 : if (!forRead && !forWrite)
1094 0 : return 0;
1095 :
1096 834180 : input_fd.fd = sock;
1097 834180 : input_fd.events = POLLERR;
1098 834180 : input_fd.revents = 0;
1099 :
1100 834180 : if (forRead)
1101 812488 : input_fd.events |= POLLIN;
1102 834180 : if (forWrite)
1103 21728 : input_fd.events |= POLLOUT;
1104 :
1105 : /* Compute appropriate timeout interval */
1106 834180 : if (end_time == ((time_t) -1))
1107 833362 : timeout_ms = -1;
1108 : else
1109 : {
1110 818 : time_t now = time(NULL);
1111 :
1112 818 : if (end_time > now)
1113 632 : timeout_ms = (end_time - now) * 1000;
1114 : else
1115 186 : timeout_ms = 0;
1116 : }
1117 :
1118 834180 : return poll(&input_fd, 1, timeout_ms);
1119 : #else /* !HAVE_POLL */
1120 :
1121 : fd_set input_mask;
1122 : fd_set output_mask;
1123 : fd_set except_mask;
1124 : struct timeval timeout;
1125 : struct timeval *ptr_timeout;
1126 :
1127 : if (!forRead && !forWrite)
1128 : return 0;
1129 :
1130 : FD_ZERO(&input_mask);
1131 : FD_ZERO(&output_mask);
1132 : FD_ZERO(&except_mask);
1133 : if (forRead)
1134 : FD_SET(sock, &input_mask);
1135 :
1136 : if (forWrite)
1137 : FD_SET(sock, &output_mask);
1138 : FD_SET(sock, &except_mask);
1139 :
1140 : /* Compute appropriate timeout interval */
1141 : if (end_time == ((time_t) -1))
1142 : ptr_timeout = NULL;
1143 : else
1144 : {
1145 : time_t now = time(NULL);
1146 :
1147 : if (end_time > now)
1148 : timeout.tv_sec = end_time - now;
1149 : else
1150 : timeout.tv_sec = 0;
1151 : timeout.tv_usec = 0;
1152 : ptr_timeout = &timeout;
1153 : }
1154 :
1155 : return select(sock + 1, &input_mask, &output_mask,
1156 : &except_mask, ptr_timeout);
1157 : #endif /* HAVE_POLL */
1158 : }
1159 :
1160 :
1161 : /*
1162 : * A couple of "miscellaneous" multibyte related functions. They used
1163 : * to be in fe-print.c but that file is doomed.
1164 : */
1165 :
1166 : /*
1167 : * Returns the byte length of the character beginning at s, using the
1168 : * specified encoding.
1169 : *
1170 : * Caution: when dealing with text that is not certainly valid in the
1171 : * specified encoding, the result may exceed the actual remaining
1172 : * string length. Callers that are not prepared to deal with that
1173 : * should use PQmblenBounded() instead.
1174 : */
1175 : int
1176 50245574 : PQmblen(const char *s, int encoding)
1177 : {
1178 50245574 : return pg_encoding_mblen(encoding, s);
1179 : }
1180 :
1181 : /*
1182 : * Returns the byte length of the character beginning at s, using the
1183 : * specified encoding; but not more than the distance to end of string.
1184 : */
1185 : int
1186 743074 : PQmblenBounded(const char *s, int encoding)
1187 : {
1188 743074 : return strnlen(s, pg_encoding_mblen(encoding, s));
1189 : }
1190 :
1191 : /*
1192 : * Returns the display length of the character beginning at s, using the
1193 : * specified encoding.
1194 : */
1195 : int
1196 50246796 : PQdsplen(const char *s, int encoding)
1197 : {
1198 50246796 : return pg_encoding_dsplen(encoding, s);
1199 : }
1200 :
1201 : /*
1202 : * Get encoding id from environment variable PGCLIENTENCODING.
1203 : */
1204 : int
1205 14894 : PQenv2encoding(void)
1206 : {
1207 : char *str;
1208 14894 : int encoding = PG_SQL_ASCII;
1209 :
1210 14894 : str = getenv("PGCLIENTENCODING");
1211 14894 : if (str && *str != '\0')
1212 : {
1213 12 : encoding = pg_char_to_encoding(str);
1214 12 : if (encoding < 0)
1215 0 : encoding = PG_SQL_ASCII;
1216 : }
1217 14894 : return encoding;
1218 : }
1219 :
1220 :
1221 : #ifdef ENABLE_NLS
1222 :
1223 : static void
1224 49720 : libpq_binddomain(void)
1225 : {
1226 : /*
1227 : * At least on Windows, there are gettext implementations that fail if
1228 : * multiple threads call bindtextdomain() concurrently. Use a mutex and
1229 : * flag variable to ensure that we call it just once per process. It is
1230 : * not known that similar bugs exist on non-Windows platforms, but we
1231 : * might as well do it the same way everywhere.
1232 : */
1233 : static volatile bool already_bound = false;
1234 : static pthread_mutex_t binddomain_mutex = PTHREAD_MUTEX_INITIALIZER;
1235 :
1236 49720 : if (!already_bound)
1237 : {
1238 : /* bindtextdomain() does not preserve errno */
1239 : #ifdef WIN32
1240 : int save_errno = GetLastError();
1241 : #else
1242 18810 : int save_errno = errno;
1243 : #endif
1244 :
1245 18810 : (void) pthread_mutex_lock(&binddomain_mutex);
1246 :
1247 18810 : if (!already_bound)
1248 : {
1249 : const char *ldir;
1250 :
1251 : /*
1252 : * No relocatable lookup here because the calling executable could
1253 : * be anywhere
1254 : */
1255 18810 : ldir = getenv("PGLOCALEDIR");
1256 18810 : if (!ldir)
1257 210 : ldir = LOCALEDIR;
1258 18810 : bindtextdomain(PG_TEXTDOMAIN("libpq"), ldir);
1259 18810 : already_bound = true;
1260 : }
1261 :
1262 18810 : (void) pthread_mutex_unlock(&binddomain_mutex);
1263 :
1264 : #ifdef WIN32
1265 : SetLastError(save_errno);
1266 : #else
1267 18810 : errno = save_errno;
1268 : #endif
1269 : }
1270 49720 : }
1271 :
1272 : char *
1273 49706 : libpq_gettext(const char *msgid)
1274 : {
1275 49706 : libpq_binddomain();
1276 49706 : return dgettext(PG_TEXTDOMAIN("libpq"), msgid);
1277 : }
1278 :
1279 : char *
1280 14 : libpq_ngettext(const char *msgid, const char *msgid_plural, unsigned long n)
1281 : {
1282 14 : libpq_binddomain();
1283 14 : return dngettext(PG_TEXTDOMAIN("libpq"), msgid, msgid_plural, n);
1284 : }
1285 :
1286 : #endif /* ENABLE_NLS */
1287 :
1288 :
1289 : /*
1290 : * Append a formatted string to the given buffer, after translating it. A
1291 : * newline is automatically appended; the format should not end with a
1292 : * newline.
1293 : */
1294 : void
1295 50 : libpq_append_error(PQExpBuffer errorMessage, const char *fmt,...)
1296 : {
1297 50 : int save_errno = errno;
1298 : bool done;
1299 : va_list args;
1300 :
1301 : Assert(fmt[strlen(fmt) - 1] != '\n');
1302 :
1303 50 : if (PQExpBufferBroken(errorMessage))
1304 0 : return; /* already failed */
1305 :
1306 : /* Loop in case we have to retry after enlarging the buffer. */
1307 : do
1308 : {
1309 50 : errno = save_errno;
1310 50 : va_start(args, fmt);
1311 50 : done = appendPQExpBufferVA(errorMessage, libpq_gettext(fmt), args);
1312 50 : va_end(args);
1313 50 : } while (!done);
1314 :
1315 50 : appendPQExpBufferChar(errorMessage, '\n');
1316 : }
1317 :
1318 : /*
1319 : * Append a formatted string to the error message buffer of the given
1320 : * connection, after translating it. A newline is automatically appended; the
1321 : * format should not end with a newline.
1322 : */
1323 : void
1324 840 : libpq_append_conn_error(PGconn *conn, const char *fmt,...)
1325 : {
1326 840 : int save_errno = errno;
1327 : bool done;
1328 : va_list args;
1329 :
1330 : Assert(fmt[strlen(fmt) - 1] != '\n');
1331 :
1332 840 : if (PQExpBufferBroken(&conn->errorMessage))
1333 0 : return; /* already failed */
1334 :
1335 : /* Loop in case we have to retry after enlarging the buffer. */
1336 : do
1337 : {
1338 850 : errno = save_errno;
1339 850 : va_start(args, fmt);
1340 850 : done = appendPQExpBufferVA(&conn->errorMessage, libpq_gettext(fmt), args);
1341 850 : va_end(args);
1342 850 : } while (!done);
1343 :
1344 840 : appendPQExpBufferChar(&conn->errorMessage, '\n');
1345 : }
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