Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * connection.c
4 : : * Connection management functions for postgres_fdw
5 : : *
6 : : * Portions Copyright (c) 2012-2026, PostgreSQL Global Development Group
7 : : *
8 : : * IDENTIFICATION
9 : : * contrib/postgres_fdw/connection.c
10 : : *
11 : : *-------------------------------------------------------------------------
12 : : */
13 : : #include "postgres.h"
14 : :
15 : : #if HAVE_POLL_H
16 : : #include <poll.h>
17 : : #endif
18 : :
19 : : #include "access/htup_details.h"
20 : : #include "access/xact.h"
21 : : #include "catalog/pg_user_mapping.h"
22 : : #include "commands/defrem.h"
23 : : #include "common/base64.h"
24 : : #include "funcapi.h"
25 : : #include "libpq/libpq-be.h"
26 : : #include "libpq/libpq-be-fe-helpers.h"
27 : : #include "mb/pg_wchar.h"
28 : : #include "miscadmin.h"
29 : : #include "pgstat.h"
30 : : #include "postgres_fdw.h"
31 : : #include "storage/latch.h"
32 : : #include "utils/builtins.h"
33 : : #include "utils/hsearch.h"
34 : : #include "utils/inval.h"
35 : : #include "utils/syscache.h"
36 : : #include "utils/tuplestore.h"
37 : :
38 : : /*
39 : : * Connection cache hash table entry
40 : : *
41 : : * The lookup key in this hash table is the user mapping OID. We use just one
42 : : * connection per user mapping ID, which ensures that all the scans use the
43 : : * same snapshot during a query. Using the user mapping OID rather than
44 : : * the foreign server OID + user OID avoids creating multiple connections when
45 : : * the public user mapping applies to all user OIDs.
46 : : *
47 : : * The "conn" pointer can be NULL if we don't currently have a live connection.
48 : : * When we do have a connection, xact_depth tracks the current depth of
49 : : * transactions and subtransactions open on the remote side. We need to issue
50 : : * commands at the same nesting depth on the remote as we're executing at
51 : : * ourselves, so that rolling back a subtransaction will kill the right
52 : : * queries and not the wrong ones.
53 : : */
54 : : typedef Oid ConnCacheKey;
55 : :
56 : : typedef struct ConnCacheEntry
57 : : {
58 : : ConnCacheKey key; /* hash key (must be first) */
59 : : PGconn *conn; /* connection to foreign server, or NULL */
60 : : /* Remaining fields are invalid when conn is NULL: */
61 : : int xact_depth; /* 0 = no xact open, 1 = main xact open, 2 =
62 : : * one level of subxact open, etc */
63 : : bool xact_read_only; /* xact r/o state */
64 : : bool have_prep_stmt; /* have we prepared any stmts in this xact? */
65 : : bool have_error; /* have any subxacts aborted in this xact? */
66 : : bool changing_xact_state; /* xact state change in process */
67 : : bool parallel_commit; /* do we commit (sub)xacts in parallel? */
68 : : bool parallel_abort; /* do we abort (sub)xacts in parallel? */
69 : : bool invalidated; /* true if reconnect is pending */
70 : : bool keep_connections; /* setting value of keep_connections
71 : : * server option */
72 : : Oid serverid; /* foreign server OID used to get server name */
73 : : uint32 server_hashvalue; /* hash value of foreign server OID */
74 : : uint32 mapping_hashvalue; /* hash value of user mapping OID */
75 : : PgFdwConnState state; /* extra per-connection state */
76 : : } ConnCacheEntry;
77 : :
78 : : /*
79 : : * Connection cache (initialized on first use)
80 : : */
81 : : static HTAB *ConnectionHash = NULL;
82 : :
83 : : /* for assigning cursor numbers and prepared statement numbers */
84 : : static unsigned int cursor_number = 0;
85 : : static unsigned int prep_stmt_number = 0;
86 : :
87 : : /* tracks whether any work is needed in callback functions */
88 : : static bool xact_got_connection = false;
89 : :
90 : : /*
91 : : * tracks the topmost read-only local transaction's nesting level determined
92 : : * by GetTopReadOnlyTransactionNestLevel()
93 : : */
94 : : static int read_only_level = 0;
95 : :
96 : : /* custom wait event values, retrieved from shared memory */
97 : : static uint32 pgfdw_we_cleanup_result = 0;
98 : : static uint32 pgfdw_we_connect = 0;
99 : : static uint32 pgfdw_we_get_result = 0;
100 : :
101 : : /*
102 : : * Milliseconds to wait to cancel an in-progress query or execute a cleanup
103 : : * query; if it takes longer than 30 seconds to do these, we assume the
104 : : * connection is dead.
105 : : */
106 : : #define CONNECTION_CLEANUP_TIMEOUT 30000
107 : :
108 : : /*
109 : : * Milliseconds to wait before issuing another cancel request. This covers
110 : : * the race condition where the remote session ignored our cancel request
111 : : * because it arrived while idle.
112 : : */
113 : : #define RETRY_CANCEL_TIMEOUT 1000
114 : :
115 : : /*
116 : : * Macro for constructing commit command to be sent
117 : : *
118 : : * We synchronize the read/write mode before committing remote transactions
119 : : * so deferred triggers on remote servers can run in the right mode.
120 : : */
121 : : #define CONSTRUCT_COMMIT_COMMAND(sql, entry) \
122 : : do { \
123 : : if ((read_only_level > 0) && !(entry)->xact_read_only) \
124 : : strcpy((sql), "SET TRANSACTION READ ONLY; COMMIT TRANSACTION"); \
125 : : else \
126 : : strcpy((sql), "COMMIT TRANSACTION"); \
127 : : } while(0)
128 : :
129 : : /* Macro for constructing abort command to be sent */
130 : : #define CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel) \
131 : : do { \
132 : : if (toplevel) \
133 : : snprintf((sql), sizeof(sql), \
134 : : "ABORT TRANSACTION"); \
135 : : else \
136 : : snprintf((sql), sizeof(sql), \
137 : : "ROLLBACK TO SAVEPOINT s%d; RELEASE SAVEPOINT s%d", \
138 : : (entry)->xact_depth, (entry)->xact_depth); \
139 : : } while(0)
140 : :
141 : : /*
142 : : * Extension version number, for supporting older extension versions' objects
143 : : */
144 : : enum pgfdwVersion
145 : : {
146 : : PGFDW_V1_1 = 0,
147 : : PGFDW_V1_2,
148 : : };
149 : :
150 : : /*
151 : : * SQL functions
152 : : */
2093 fujii@postgresql.org 153 :CBC 6 : PG_FUNCTION_INFO_V1(postgres_fdw_get_connections);
808 154 : 7 : PG_FUNCTION_INFO_V1(postgres_fdw_get_connections_1_2);
2085 155 : 7 : PG_FUNCTION_INFO_V1(postgres_fdw_disconnect);
156 : 7 : PG_FUNCTION_INFO_V1(postgres_fdw_disconnect_all);
220 jdavis@postgresql.or 157 : 14 : PG_FUNCTION_INFO_V1(postgres_fdw_connection);
158 : :
159 : : /* prototypes of private functions */
160 : : static void make_new_connection(ConnCacheEntry *entry, UserMapping *user);
161 : : static PGconn *connect_pg_server(ForeignServer *server, UserMapping *user);
162 : : static void disconnect_pg_server(ConnCacheEntry *entry);
163 : : static void check_conn_params(const char **keywords, const char **values, UserMapping *user);
164 : : static void configure_remote_session(PGconn *conn);
165 : : static void do_sql_command_begin(PGconn *conn, const char *sql);
166 : : static void do_sql_command_end(PGconn *conn, const char *sql,
167 : : bool consume_input);
168 : : static void begin_remote_xact(ConnCacheEntry *entry);
169 : : static void pgfdw_report_internal(int elevel, PGresult *res, PGconn *conn,
170 : : const char *sql);
171 : : static void pgfdw_xact_callback(XactEvent event, void *arg);
172 : : static void pgfdw_subxact_callback(SubXactEvent event,
173 : : SubTransactionId mySubid,
174 : : SubTransactionId parentSubid,
175 : : void *arg);
176 : : static void pgfdw_inval_callback(Datum arg, SysCacheIdentifier cacheid,
177 : : uint32 hashvalue);
178 : : static void pgfdw_reject_incomplete_xact_state_change(ConnCacheEntry *entry);
179 : : static void pgfdw_reset_xact_state(ConnCacheEntry *entry, bool toplevel);
180 : : static bool pgfdw_cancel_query(PGconn *conn);
181 : : static bool pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime);
182 : : static bool pgfdw_cancel_query_end(PGconn *conn, TimestampTz endtime,
183 : : TimestampTz retrycanceltime,
184 : : bool consume_input);
185 : : static bool pgfdw_exec_cleanup_query(PGconn *conn, const char *query,
186 : : bool ignore_errors);
187 : : static bool pgfdw_exec_cleanup_query_begin(PGconn *conn, const char *query);
188 : : static bool pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query,
189 : : TimestampTz endtime,
190 : : bool consume_input,
191 : : bool ignore_errors);
192 : : static bool pgfdw_get_cleanup_result(PGconn *conn, TimestampTz endtime,
193 : : TimestampTz retrycanceltime,
194 : : PGresult **result, bool *timed_out);
195 : : static void pgfdw_abort_cleanup(ConnCacheEntry *entry, bool toplevel);
196 : : static bool pgfdw_abort_cleanup_begin(ConnCacheEntry *entry, bool toplevel,
197 : : List **pending_entries,
198 : : List **cancel_requested);
199 : : static void pgfdw_finish_pre_commit_cleanup(List *pending_entries);
200 : : static void pgfdw_finish_pre_subcommit_cleanup(List *pending_entries,
201 : : int curlevel);
202 : : static void pgfdw_finish_abort_cleanup(List *pending_entries,
203 : : List *cancel_requested,
204 : : bool toplevel);
205 : : static void pgfdw_security_check(const char **keywords, const char **values,
206 : : UserMapping *user, PGconn *conn);
207 : : static bool UserMappingPasswordRequired(UserMapping *user);
208 : : static bool UseScramPassthrough(ForeignServer *server, UserMapping *user);
209 : : static bool disconnect_cached_connections(Oid serverid);
210 : : static void postgres_fdw_get_connections_internal(FunctionCallInfo fcinfo,
211 : : enum pgfdwVersion api_version);
212 : : static int pgfdw_conn_check(PGconn *conn);
213 : : static bool pgfdw_conn_checkable(void);
214 : : static bool pgfdw_has_required_scram_options(const char **keywords, const char **values);
215 : :
216 : : /*
217 : : * Get a PGconn which can be used to execute queries on the remote PostgreSQL
218 : : * server with the user's authorization. A new connection is established
219 : : * if we don't already have a suitable one, and a transaction is opened at
220 : : * the right subtransaction nesting depth if we didn't do that already.
221 : : *
222 : : * will_prep_stmt must be true if caller intends to create any prepared
223 : : * statements. Since those don't go away automatically at transaction end
224 : : * (not even on error), we need this flag to cue manual cleanup.
225 : : *
226 : : * If state is not NULL, *state receives the per-connection state associated
227 : : * with the PGconn.
228 : : */
229 : : PGconn *
2021 efujita@postgresql.o 230 : 2344 : GetConnection(UserMapping *user, bool will_prep_stmt, PgFdwConnState **state)
231 : : {
232 : : bool found;
2187 fujii@postgresql.org 233 : 2344 : bool retry = false;
234 : : ConnCacheEntry *entry;
235 : : ConnCacheKey key;
236 : 2344 : MemoryContext ccxt = CurrentMemoryContext;
237 : :
238 : : /* First time through, initialize connection cache hashtable */
4981 tgl@sss.pgh.pa.us 239 [ + + ]: 2344 : if (ConnectionHash == NULL)
240 : : {
241 : : HASHCTL ctl;
242 : :
1008 noah@leadboat.com 243 [ + - ]: 11 : if (pgfdw_we_get_result == 0)
244 : 11 : pgfdw_we_get_result =
245 : 11 : WaitEventExtensionNew("PostgresFdwGetResult");
246 : :
4981 tgl@sss.pgh.pa.us 247 : 11 : ctl.keysize = sizeof(ConnCacheKey);
248 : 11 : ctl.entrysize = sizeof(ConnCacheEntry);
249 : 11 : ConnectionHash = hash_create("postgres_fdw connections", 8,
250 : : &ctl,
251 : : HASH_ELEM | HASH_BLOBS);
252 : :
253 : : /*
254 : : * Register some callback functions that manage connection cleanup.
255 : : * This should be done just once in each backend.
256 : : */
257 : 11 : RegisterXactCallback(pgfdw_xact_callback, NULL);
258 : 11 : RegisterSubXactCallback(pgfdw_subxact_callback, NULL);
3370 259 : 11 : CacheRegisterSyscacheCallback(FOREIGNSERVEROID,
260 : : pgfdw_inval_callback, (Datum) 0);
261 : 11 : CacheRegisterSyscacheCallback(USERMAPPINGOID,
262 : : pgfdw_inval_callback, (Datum) 0);
263 : : }
264 : :
265 : : /* Set flag that we did GetConnection during the current transaction */
4981 266 : 2344 : xact_got_connection = true;
267 : :
268 : : /* Create hash key for the entry. Assume no pad bytes in key struct */
3910 rhaas@postgresql.org 269 : 2344 : key = user->umid;
270 : :
271 : : /*
272 : : * Find or create cached entry for requested connection.
273 : : */
4981 tgl@sss.pgh.pa.us 274 : 2344 : entry = hash_search(ConnectionHash, &key, HASH_ENTER, &found);
275 [ + + ]: 2344 : if (!found)
276 : : {
277 : : /*
278 : : * We need only clear "conn" here; remaining fields will be filled
279 : : * later when "conn" is set.
280 : : */
281 : 22 : entry->conn = NULL;
282 : : }
283 : :
284 : : /* Reject further use of connections which failed abort cleanup. */
3414 rhaas@postgresql.org 285 : 2344 : pgfdw_reject_incomplete_xact_state_change(entry);
286 : :
287 : : /*
288 : : * If the connection needs to be remade due to invalidation, disconnect as
289 : : * soon as we're out of all transactions.
290 : : */
2187 fujii@postgresql.org 291 [ + + - + : 2342 : if (entry->conn != NULL && entry->invalidated && entry->xact_depth == 0)
- - ]
292 : : {
2187 fujii@postgresql.org 293 [ # # ]:UBC 0 : elog(DEBUG3, "closing connection %p for option changes to take effect",
294 : : entry->conn);
3370 tgl@sss.pgh.pa.us 295 : 0 : disconnect_pg_server(entry);
296 : : }
297 : :
298 : : /*
299 : : * If cache entry doesn't have a connection, we have to establish a new
300 : : * connection. (If connect_pg_server throws an error, the cache entry
301 : : * will remain in a valid empty state, ie conn == NULL.)
302 : : */
4981 tgl@sss.pgh.pa.us 303 [ + + ]:CBC 2342 : if (entry->conn == NULL)
2187 fujii@postgresql.org 304 : 87 : make_new_connection(entry, user);
305 : :
306 : : /*
307 : : * We check the health of the cached connection here when using it. In
308 : : * cases where we're out of all transactions, if a broken connection is
309 : : * detected, we try to reestablish a new connection later.
310 : : */
2197 311 [ + + ]: 2335 : PG_TRY();
312 : : {
313 : : /* Process a pending asynchronous request if any. */
2021 efujita@postgresql.o 314 [ - + ]: 2335 : if (entry->state.pendingAreq)
2021 efujita@postgresql.o 315 :UBC 0 : process_pending_request(entry->state.pendingAreq);
316 : : /* Start a new transaction or subtransaction if needed. */
2197 fujii@postgresql.org 317 :CBC 2335 : begin_remote_xact(entry);
318 : : }
319 : 2 : PG_CATCH();
320 : : {
2187 321 : 2 : MemoryContext ecxt = MemoryContextSwitchTo(ccxt);
322 : 2 : ErrorData *errdata = CopyErrorData();
323 : :
324 : : /*
325 : : * Determine whether to try to reestablish the connection.
326 : : *
327 : : * After a broken connection is detected in libpq, any error other
328 : : * than connection failure (e.g., out-of-memory) can be thrown
329 : : * somewhere between return from libpq and the expected ereport() call
330 : : * in pgfdw_report_error(). In this case, since PQstatus() indicates
331 : : * CONNECTION_BAD, checking only PQstatus() causes the false detection
332 : : * of connection failure. To avoid this, we also verify that the
333 : : * error's sqlstate is ERRCODE_CONNECTION_FAILURE. Note that also
334 : : * checking only the sqlstate can cause another false detection
335 : : * because pgfdw_report_error() may report ERRCODE_CONNECTION_FAILURE
336 : : * for any libpq-originated error condition.
337 : : */
338 [ + - ]: 2 : if (errdata->sqlerrcode != ERRCODE_CONNECTION_FAILURE ||
339 [ + - ]: 2 : PQstatus(entry->conn) != CONNECTION_BAD ||
340 [ + + ]: 2 : entry->xact_depth > 0)
341 : : {
342 : 1 : MemoryContextSwitchTo(ecxt);
2197 343 : 1 : PG_RE_THROW();
344 : : }
345 : :
346 : : /* Clean up the error state */
2187 347 : 1 : FlushErrorState();
348 : 1 : FreeErrorData(errdata);
349 : 1 : errdata = NULL;
350 : :
351 : 1 : retry = true;
352 : : }
2197 353 [ - + ]: 2334 : PG_END_TRY();
354 : :
355 : : /*
356 : : * If a broken connection is detected, disconnect it, reestablish a new
357 : : * connection and retry a new remote transaction. If connection failure is
358 : : * reported again, we give up getting a connection.
359 : : */
2187 360 [ + + ]: 2334 : if (retry)
361 : : {
362 [ - + ]: 1 : Assert(entry->xact_depth == 0);
363 : :
2197 364 [ - + ]: 1 : ereport(DEBUG3,
365 : : (errmsg_internal("could not start remote transaction on connection %p",
366 : : entry->conn)),
367 : : errdetail_internal("%s", pchomp(PQerrorMessage(entry->conn))));
368 : :
2187 369 [ - + ]: 1 : elog(DEBUG3, "closing connection %p to reestablish a new one",
370 : : entry->conn);
371 : 1 : disconnect_pg_server(entry);
372 : :
1305 efujita@postgresql.o 373 : 1 : make_new_connection(entry, user);
374 : :
2187 fujii@postgresql.org 375 : 1 : begin_remote_xact(entry);
376 : : }
377 : :
378 : : /* Remember if caller will prepare statements */
4964 tgl@sss.pgh.pa.us 379 : 2334 : entry->have_prep_stmt |= will_prep_stmt;
380 : :
381 : : /* If caller needs access to the per-connection state, return it. */
2021 efujita@postgresql.o 382 [ + + ]: 2334 : if (state)
383 : 809 : *state = &entry->state;
384 : :
4981 tgl@sss.pgh.pa.us 385 : 2334 : return entry->conn;
386 : : }
387 : :
388 : : /*
389 : : * Reset all transient state fields in the cached connection entry and
390 : : * establish new connection to the remote server.
391 : : */
392 : : static void
2187 fujii@postgresql.org 393 : 88 : make_new_connection(ConnCacheEntry *entry, UserMapping *user)
394 : : {
395 : 88 : ForeignServer *server = GetForeignServer(user->serverid);
396 : : ListCell *lc;
397 : :
398 [ - + ]: 88 : Assert(entry->conn == NULL);
399 : :
400 : : /* Reset all transient state fields, to be sure all are clean */
401 : 88 : entry->xact_depth = 0;
190 efujita@postgresql.o 402 : 88 : entry->xact_read_only = false;
2187 fujii@postgresql.org 403 : 88 : entry->have_prep_stmt = false;
404 : 88 : entry->have_error = false;
405 : 88 : entry->changing_xact_state = false;
406 : 88 : entry->invalidated = false;
2096 407 : 88 : entry->serverid = server->serverid;
2187 408 : 88 : entry->server_hashvalue =
409 : 88 : GetSysCacheHashValue1(FOREIGNSERVEROID,
410 : : ObjectIdGetDatum(server->serverid));
411 : 88 : entry->mapping_hashvalue =
412 : 88 : GetSysCacheHashValue1(USERMAPPINGOID,
413 : : ObjectIdGetDatum(user->umid));
2021 efujita@postgresql.o 414 : 88 : memset(&entry->state, 0, sizeof(entry->state));
415 : :
416 : : /*
417 : : * Determine whether to keep the connection that we're about to make here
418 : : * open even after the transaction using it ends, so that the subsequent
419 : : * transactions can re-use it.
420 : : *
421 : : * By default, all the connections to any foreign servers are kept open.
422 : : *
423 : : * Also determine whether to commit/abort (sub)transactions opened on the
424 : : * remote server in parallel at (sub)transaction end, which is disabled by
425 : : * default.
426 : : *
427 : : * Note: it's enough to determine these only when making a new connection
428 : : * because if these settings for it are changed, it will be closed and
429 : : * re-made later.
430 : : */
2019 fujii@postgresql.org 431 : 88 : entry->keep_connections = true;
1691 efujita@postgresql.o 432 : 88 : entry->parallel_commit = false;
1285 433 : 88 : entry->parallel_abort = false;
2019 fujii@postgresql.org 434 [ + - + + : 413 : foreach(lc, server->options)
+ + ]
435 : : {
436 : 325 : DefElem *def = (DefElem *) lfirst(lc);
437 : :
438 [ + + ]: 325 : if (strcmp(def->defname, "keep_connections") == 0)
439 : 18 : entry->keep_connections = defGetBoolean(def);
1691 efujita@postgresql.o 440 [ + + ]: 307 : else if (strcmp(def->defname, "parallel_commit") == 0)
441 : 2 : entry->parallel_commit = defGetBoolean(def);
1285 442 [ + + ]: 305 : else if (strcmp(def->defname, "parallel_abort") == 0)
443 : 2 : entry->parallel_abort = defGetBoolean(def);
444 : : }
445 : :
446 : : /* Now try to make the connection */
2187 fujii@postgresql.org 447 : 88 : entry->conn = connect_pg_server(server, user);
448 : :
449 [ - + ]: 81 : elog(DEBUG3, "new postgres_fdw connection %p for server \"%s\" (user mapping oid %u, userid %u)",
450 : : entry->conn, server->servername, user->umid, user->userid);
451 : 81 : }
452 : :
453 : : /*
454 : : * Check that non-superuser has used password or delegated credentials
455 : : * to establish connection; otherwise, he's piggybacking on the
456 : : * postgres server's user identity. See also dblink_security_check()
457 : : * in contrib/dblink and check_conn_params.
458 : : */
459 : : static void
1278 sfrost@snowman.net 460 : 83 : pgfdw_security_check(const char **keywords, const char **values, UserMapping *user, PGconn *conn)
461 : : {
462 : : /* Superusers bypass the check */
463 [ + + ]: 83 : if (superuser_arg(user->userid))
464 : 75 : return;
465 : :
466 : : #ifdef ENABLE_GSS
467 : : /* Connected via GSSAPI with delegated credentials- all good. */
1241 bruce@momjian.us 468 [ - + - - ]: 8 : if (PQconnectionUsedGSSAPI(conn) && be_gssapi_get_delegation(MyProcPort))
1278 sfrost@snowman.net 469 :UBC 0 : return;
470 : : #endif
471 : :
472 : : /* Ok if superuser set PW required false. */
1278 sfrost@snowman.net 473 [ + + ]:CBC 8 : if (!UserMappingPasswordRequired(user))
474 : 2 : return;
475 : :
476 : : /* Connected via PW, with PW required true, and provided non-empty PW. */
477 [ + + ]: 6 : if (PQconnectionUsedPassword(conn))
478 : : {
479 : : /* ok if params contain a non-empty password */
480 [ + + ]: 40 : for (int i = 0; keywords[i] != NULL; i++)
481 : : {
482 [ - + - - ]: 36 : if (strcmp(keywords[i], "password") == 0 && values[i][0] != '\0')
1278 sfrost@snowman.net 483 :UBC 0 : return;
484 : : }
485 : : }
486 : :
487 : : /*
488 : : * Ok if SCRAM pass-through is being used and all required SCRAM options
489 : : * are set correctly. If pgfdw_has_required_scram_options returns true we
490 : : * assume that UseScramPassthrough is also true since SCRAM options are
491 : : * only set when UseScramPassthrough is enabled.
492 : : */
430 peter@eisentraut.org 493 [ + - + + :CBC 6 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && pgfdw_has_required_scram_options(keywords, values))
+ - ]
567 494 : 4 : return;
495 : :
1278 sfrost@snowman.net 496 [ + - ]: 2 : ereport(ERROR,
497 : : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
498 : : errmsg("password or GSSAPI delegated credentials required"),
499 : : errdetail("Non-superuser cannot connect if the server does not request a password or use GSSAPI with delegated credentials."),
500 : : errhint("Target server's authentication method must be changed or password_required=false set in the user mapping attributes.")));
501 : : }
502 : :
503 : : /*
504 : : * Construct connection params from generic options of ForeignServer and
505 : : * UserMapping. (Some of them might not be libpq options, in which case we'll
506 : : * just waste a few array slots.)
507 : : */
508 : : static void
220 jdavis@postgresql.or 509 : 95 : construct_connection_params(ForeignServer *server, UserMapping *user,
510 : : const char ***p_keywords, const char ***p_values,
511 : : char **p_appname)
512 : : {
513 : : const char **keywords;
514 : : const char **values;
515 : 95 : char *appname = NULL;
516 : : int n;
517 : :
518 : : /*
519 : : * Add 4 extra slots for application_name, fallback_application_name,
520 : : * client_encoding, end marker, and 3 extra slots for scram keys and
521 : : * required scram pass-through options.
522 : : */
523 : 95 : n = list_length(server->options) + list_length(user->options) + 4 + 3;
56 michael@paquier.xyz 524 :GNC 95 : keywords = palloc_array(const char *, n);
525 : 95 : values = palloc_array(const char *, n);
526 : :
220 jdavis@postgresql.or 527 :CBC 95 : n = 0;
528 : 190 : n += ExtractConnectionOptions(server->options,
529 : 95 : keywords + n, values + n);
530 : 190 : n += ExtractConnectionOptions(user->options,
531 : 95 : keywords + n, values + n);
532 : :
533 : : /*
534 : : * Use pgfdw_application_name as application_name if set.
535 : : *
536 : : * PQconnectdbParams() processes the parameter arrays from start to end.
537 : : * If any key word is repeated, the last value is used. Therefore note
538 : : * that pgfdw_application_name must be added to the arrays after options
539 : : * of ForeignServer are, so that it can override application_name set in
540 : : * ForeignServer.
541 : : */
542 [ + + + - ]: 95 : if (pgfdw_application_name && *pgfdw_application_name != '\0')
543 : : {
544 : 1 : keywords[n] = "application_name";
545 : 1 : values[n] = pgfdw_application_name;
546 : 1 : n++;
547 : : }
548 : :
549 : : /*
550 : : * Search the parameter arrays to find application_name setting, and
551 : : * replace escape sequences in it with status information if found. The
552 : : * arrays are searched backwards because the last value is used if
553 : : * application_name is repeatedly set.
554 : : */
555 [ + + ]: 250 : for (int i = n - 1; i >= 0; i--)
556 : : {
557 [ + + ]: 183 : if (strcmp(keywords[i], "application_name") == 0 &&
558 [ + - ]: 28 : *(values[i]) != '\0')
559 : : {
560 : : /*
561 : : * Use this application_name setting if it's not empty string even
562 : : * after any escape sequences in it are replaced.
563 : : */
564 : 28 : appname = process_pgfdw_appname(values[i]);
565 [ + - ]: 28 : if (appname[0] != '\0')
566 : : {
567 : 28 : values[i] = appname;
568 : 28 : break;
569 : : }
570 : :
571 : : /*
572 : : * This empty application_name is not used, so we set values[i] to
573 : : * NULL and keep searching the array to find the next one.
574 : : */
220 jdavis@postgresql.or 575 :UBC 0 : values[i] = NULL;
576 : 0 : pfree(appname);
577 : 0 : appname = NULL;
578 : : }
579 : : }
580 : :
220 jdavis@postgresql.or 581 :CBC 95 : *p_appname = appname;
582 : :
583 : : /* Use "postgres_fdw" as fallback_application_name */
584 : 95 : keywords[n] = "fallback_application_name";
585 : 95 : values[n] = "postgres_fdw";
586 : 95 : n++;
587 : :
588 : : /* Set client_encoding so that libpq can convert encoding properly. */
589 : 95 : keywords[n] = "client_encoding";
590 : 95 : values[n] = GetDatabaseEncodingName();
591 : 95 : n++;
592 : :
593 : : /* Add required SCRAM pass-through connection options if it's enabled. */
594 [ + + + + : 95 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && UseScramPassthrough(server, user))
+ + ]
595 : : {
596 : : int len;
597 : : char *encoded;
598 : : int encoded_len;
599 : :
600 : 4 : keywords[n] = "scram_client_key";
601 : 4 : len = pg_b64_enc_len(sizeof(MyProcPort->scram_ClientKey));
602 : : /* don't forget the zero-terminator */
55 peter@eisentraut.org 603 :GNC 4 : encoded = palloc0(len + 1);
220 jdavis@postgresql.or 604 :CBC 4 : encoded_len = pg_b64_encode(MyProcPort->scram_ClientKey,
605 : : sizeof(MyProcPort->scram_ClientKey),
606 : : encoded, len);
607 [ - + ]: 4 : if (encoded_len < 0)
220 jdavis@postgresql.or 608 [ # # ]:UBC 0 : elog(ERROR, "could not encode SCRAM client key");
55 peter@eisentraut.org 609 :GNC 4 : values[n] = encoded;
4981 tgl@sss.pgh.pa.us 610 :CBC 4 : n++;
611 : :
220 jdavis@postgresql.or 612 : 4 : keywords[n] = "scram_server_key";
613 : 4 : len = pg_b64_enc_len(sizeof(MyProcPort->scram_ServerKey));
614 : : /* don't forget the zero-terminator */
55 peter@eisentraut.org 615 :GNC 4 : encoded = palloc0(len + 1);
220 jdavis@postgresql.or 616 :CBC 4 : encoded_len = pg_b64_encode(MyProcPort->scram_ServerKey,
617 : : sizeof(MyProcPort->scram_ServerKey),
618 : : encoded, len);
619 [ - + ]: 4 : if (encoded_len < 0)
220 jdavis@postgresql.or 620 [ # # ]:UBC 0 : elog(ERROR, "could not encode SCRAM server key");
55 peter@eisentraut.org 621 :GNC 4 : values[n] = encoded;
4981 tgl@sss.pgh.pa.us 622 :CBC 4 : n++;
623 : :
624 : : /*
625 : : * Require scram-sha-256 to ensure that no other auth method is used
626 : : * when connecting with foreign server.
627 : : */
220 jdavis@postgresql.or 628 : 4 : keywords[n] = "require_auth";
629 : 4 : values[n] = "scram-sha-256";
630 : 4 : n++;
631 : : }
632 : :
633 : 95 : keywords[n] = values[n] = NULL;
634 : :
635 : : /* Verify the set of connection parameters. */
636 : 95 : check_conn_params(keywords, values, user);
637 : :
638 : 92 : *p_keywords = keywords;
639 : 92 : *p_values = values;
640 : 92 : }
641 : :
642 : : /*
643 : : * Connect to remote server using specified server and user mapping properties.
644 : : */
645 : : static PGconn *
646 : 88 : connect_pg_server(ForeignServer *server, UserMapping *user)
647 : : {
648 : 88 : PGconn *volatile conn = NULL;
649 : :
650 : : /*
651 : : * Use PG_TRY block to ensure closing connection on error.
652 : : */
653 [ + + ]: 88 : PG_TRY();
654 : : {
655 : : const char **keywords;
656 : : const char **values;
657 : : char *appname;
658 : : PGconn *start_conn;
659 : :
660 : 88 : construct_connection_params(server, user, &keywords, &values, &appname);
661 : :
662 : : /* first time, allocate or get the custom wait event */
1103 michael@paquier.xyz 663 [ + + ]: 85 : if (pgfdw_we_connect == 0)
664 : 10 : pgfdw_we_connect = WaitEventExtensionNew("PostgresFdwConnect");
665 : :
666 : : /* OK to make connection */
667 : : start_conn =
137 fujii@postgresql.org 668 : 85 : libpqsrv_connect_params_start(keywords, values,
669 : : /* expand_dbname = */ false);
142 670 : 85 : PQsetNoticeReceiver(start_conn, libpqsrv_notice_receiver,
671 : : "received message via remote connection");
672 : 85 : libpqsrv_connect_complete(start_conn, pgfdw_we_connect);
673 : 85 : conn = start_conn;
674 : :
4981 tgl@sss.pgh.pa.us 675 [ + - + + ]: 85 : if (!conn || PQstatus(conn) != CONNECTION_OK)
676 [ + - ]: 2 : ereport(ERROR,
677 : : (errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
678 : : errmsg("could not connect to server \"%s\"",
679 : : server->servername),
680 : : errdetail_internal("%s", pchomp(PQerrorMessage(conn)))));
681 : :
682 : : /* Perform post-connection security checks. */
567 peter@eisentraut.org 683 : 83 : pgfdw_security_check(keywords, values, user, conn);
684 : :
685 : : /* Prepare new session for use */
4980 tgl@sss.pgh.pa.us 686 : 81 : configure_remote_session(conn);
687 : :
1753 fujii@postgresql.org 688 [ + + ]: 81 : if (appname != NULL)
689 : 28 : pfree(appname);
4981 tgl@sss.pgh.pa.us 690 : 81 : pfree(keywords);
691 : 81 : pfree(values);
692 : : }
693 : 7 : PG_CATCH();
694 : : {
1358 andres@anarazel.de 695 : 7 : libpqsrv_disconnect(conn);
4981 tgl@sss.pgh.pa.us 696 : 7 : PG_RE_THROW();
697 : : }
698 [ - + ]: 81 : PG_END_TRY();
699 : :
700 : 81 : return conn;
701 : : }
702 : :
703 : : /*
704 : : * Disconnect any open connection for a connection cache entry.
705 : : */
706 : : static void
3370 707 : 72 : disconnect_pg_server(ConnCacheEntry *entry)
708 : : {
709 [ + - ]: 72 : if (entry->conn != NULL)
710 : : {
1358 andres@anarazel.de 711 : 72 : libpqsrv_disconnect(entry->conn);
3370 tgl@sss.pgh.pa.us 712 : 72 : entry->conn = NULL;
713 : : }
714 : 72 : }
715 : :
716 : : /*
717 : : * Check and return the value of password_required, if defined; otherwise,
718 : : * return true, which is the default value of it. The mapping has been
719 : : * pre-validated.
720 : : */
721 : : static bool
2488 andrew@dunslane.net 722 : 16 : UserMappingPasswordRequired(UserMapping *user)
723 : : {
724 : : ListCell *cell;
725 : :
726 [ + + + + : 29 : foreach(cell, user->options)
+ + ]
727 : : {
728 : 16 : DefElem *def = (DefElem *) lfirst(cell);
729 : :
730 [ + + ]: 16 : if (strcmp(def->defname, "password_required") == 0)
731 : 3 : return defGetBoolean(def);
732 : : }
733 : :
734 : 13 : return true;
735 : : }
736 : :
737 : : /*
738 : : * Return whether SCRAM pass-through is enabled.
739 : : *
740 : : * If use_scram_passthrough is specified in both the foreign server
741 : : * and the user mapping, the user mapping setting takes precedence.
742 : : */
743 : : static bool
635 peter@eisentraut.org 744 : 13 : UseScramPassthrough(ForeignServer *server, UserMapping *user)
745 : : {
746 : : ListCell *cell;
747 : :
139 fujii@postgresql.org 748 [ + + + + : 18 : foreach(cell, user->options)
+ + ]
749 : : {
635 peter@eisentraut.org 750 : 7 : DefElem *def = (DefElem *) lfirst(cell);
751 : :
752 [ + + ]: 7 : if (strcmp(def->defname, "use_scram_passthrough") == 0)
753 : 2 : return defGetBoolean(def);
754 : : }
755 : :
139 fujii@postgresql.org 756 [ + - + + : 44 : foreach(cell, server->options)
+ + ]
757 : : {
635 peter@eisentraut.org 758 : 37 : DefElem *def = (DefElem *) lfirst(cell);
759 : :
760 [ + + ]: 37 : if (strcmp(def->defname, "use_scram_passthrough") == 0)
761 : 4 : return defGetBoolean(def);
762 : : }
763 : :
764 : 7 : return false;
765 : : }
766 : :
767 : : /*
768 : : * For non-superusers, insist that the connstr specify a password or that the
769 : : * user provided their own GSSAPI delegated credentials. This
770 : : * prevents a password from being picked up from .pgpass, a service file, the
771 : : * environment, etc. We don't want the postgres user's passwords,
772 : : * certificates, etc to be accessible to non-superusers. (See also
773 : : * dblink_connstr_check in contrib/dblink.)
774 : : */
775 : : static void
3233 rhaas@postgresql.org 776 : 95 : check_conn_params(const char **keywords, const char **values, UserMapping *user)
777 : : {
778 : : int i;
779 : :
780 : : /* no check required if superuser */
781 [ + + ]: 95 : if (superuser_arg(user->userid))
4981 tgl@sss.pgh.pa.us 782 : 84 : return;
783 : :
784 : : #ifdef ENABLE_GSS
785 : : /* ok if the user provided their own delegated credentials */
1241 bruce@momjian.us 786 [ - + ]: 11 : if (be_gssapi_get_delegation(MyProcPort))
1278 sfrost@snowman.net 787 :UBC 0 : return;
788 : : #endif
789 : :
790 : : /* ok if params contain a non-empty password */
4981 tgl@sss.pgh.pa.us 791 [ + + ]:CBC 71 : for (i = 0; keywords[i] != NULL; i++)
792 : : {
793 [ + + + - ]: 63 : if (strcmp(keywords[i], "password") == 0 && values[i][0] != '\0')
794 : 3 : return;
795 : : }
796 : :
797 : : /* ok if the superuser explicitly said so at user mapping creation time */
2488 andrew@dunslane.net 798 [ + + ]: 8 : if (!UserMappingPasswordRequired(user))
799 : 1 : return;
800 : :
801 : : /*
802 : : * Ok if SCRAM pass-through is being used and all required scram options
803 : : * are set correctly. If pgfdw_has_required_scram_options returns true we
804 : : * assume that UseScramPassthrough is also true since SCRAM options are
805 : : * only set when UseScramPassthrough is enabled.
806 : : */
430 peter@eisentraut.org 807 [ + - + + : 7 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && pgfdw_has_required_scram_options(keywords, values))
+ + ]
567 808 : 4 : return;
809 : :
4981 tgl@sss.pgh.pa.us 810 [ + - ]: 3 : ereport(ERROR,
811 : : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
812 : : errmsg("password or GSSAPI delegated credentials required"),
813 : : errdetail("Non-superusers must delegate GSSAPI credentials, provide a password, or enable SCRAM pass-through in user mapping.")));
814 : : }
815 : :
816 : : /*
817 : : * Issue SET commands to make sure remote session is configured properly.
818 : : *
819 : : * We do this just once at connection, assuming nothing will change the
820 : : * values later. Since we'll never send volatile function calls to the
821 : : * remote, there shouldn't be any way to break this assumption from our end.
822 : : * It's possible to think of ways to break it at the remote end, eg making
823 : : * a foreign table point to a view that includes a set_config call ---
824 : : * but once you admit the possibility of a malicious view definition,
825 : : * there are any number of ways to break things.
826 : : */
827 : : static void
4980 828 : 81 : configure_remote_session(PGconn *conn)
829 : : {
4963 830 : 81 : int remoteversion = PQserverVersion(conn);
831 : :
832 : : /* Force the search path to contain only pg_catalog (see deparse.c) */
833 : 81 : do_sql_command(conn, "SET search_path = pg_catalog");
834 : :
835 : : /*
836 : : * Set remote timezone; this is basically just cosmetic, since all
837 : : * transmitted and returned timestamptzs should specify a zone explicitly
838 : : * anyway. However it makes the regression test outputs more predictable.
839 : : *
840 : : * We don't risk setting remote zone equal to ours, since the remote
841 : : * server might use a different timezone database. Instead, use GMT
842 : : * (quoted, because very old servers are picky about case). That's
843 : : * guaranteed to work regardless of the remote's timezone database,
844 : : * because pg_tzset() hard-wires it (at least in PG 9.2 and later).
845 : : */
904 846 : 81 : do_sql_command(conn, "SET timezone = 'GMT'");
847 : :
848 : : /*
849 : : * Set values needed to ensure unambiguous data output from remote. (This
850 : : * logic should match what pg_dump does. See also set_transmission_modes
851 : : * in postgres_fdw.c.)
852 : : */
4963 853 : 81 : do_sql_command(conn, "SET datestyle = ISO");
854 [ + - ]: 81 : if (remoteversion >= 80400)
855 : 81 : do_sql_command(conn, "SET intervalstyle = postgres");
856 [ + - ]: 81 : if (remoteversion >= 90000)
857 : 81 : do_sql_command(conn, "SET extra_float_digits = 3");
858 : : else
4963 tgl@sss.pgh.pa.us 859 :UBC 0 : do_sql_command(conn, "SET extra_float_digits = 2");
4963 tgl@sss.pgh.pa.us 860 :CBC 81 : }
861 : :
862 : : /*
863 : : * Convenience subroutine to issue a non-data-returning SQL command to remote
864 : : */
865 : : void
866 : 1987 : do_sql_command(PGconn *conn, const char *sql)
867 : : {
1691 efujita@postgresql.o 868 : 1987 : do_sql_command_begin(conn, sql);
869 : 1987 : do_sql_command_end(conn, sql, false);
870 : 1983 : }
871 : :
872 : : static void
873 : 2005 : do_sql_command_begin(PGconn *conn, const char *sql)
874 : : {
3414 rhaas@postgresql.org 875 [ - + ]: 2005 : if (!PQsendQuery(conn, sql))
440 tgl@sss.pgh.pa.us 876 :UBC 0 : pgfdw_report_error(NULL, conn, sql);
1691 efujita@postgresql.o 877 :CBC 2005 : }
878 : :
879 : : static void
880 : 2005 : do_sql_command_end(PGconn *conn, const char *sql, bool consume_input)
881 : : {
882 : : PGresult *res;
883 : :
884 : : /*
885 : : * If requested, consume whatever data is available from the socket. (Note
886 : : * that if all data is available, this allows pgfdw_get_result to call
887 : : * PQgetResult without forcing the overhead of WaitLatchOrSocket, which
888 : : * would be large compared to the overhead of PQconsumeInput.)
889 : : */
890 [ + + - + ]: 2005 : if (consume_input && !PQconsumeInput(conn))
440 tgl@sss.pgh.pa.us 891 :UBC 0 : pgfdw_report_error(NULL, conn, sql);
1008 noah@leadboat.com 892 :CBC 2005 : res = pgfdw_get_result(conn);
4980 tgl@sss.pgh.pa.us 893 [ + + ]: 2005 : if (PQresultStatus(res) != PGRES_COMMAND_OK)
440 894 : 4 : pgfdw_report_error(res, conn, sql);
4980 895 : 2001 : PQclear(res);
896 : 2001 : }
897 : :
898 : : /*
899 : : * Start remote transaction or subtransaction, if needed.
900 : : *
901 : : * Note that we always use at least REPEATABLE READ in the remote session.
902 : : * This is so that, if a query initiates multiple scans of the same or
903 : : * different foreign tables, we will get snapshot-consistent results from
904 : : * those scans. A disadvantage is that we can't provide sane emulation of
905 : : * READ COMMITTED behavior --- it would be nice if we had some other way to
906 : : * control which remote queries share a snapshot.
907 : : *
908 : : * Note also that we always start the remote transaction with the same
909 : : * read/write and deferrable properties as the local transaction, and start
910 : : * the remote subtransaction with the same read/write property as the local
911 : : * subtransaction.
912 : : */
913 : : static void
4981 914 : 2336 : begin_remote_xact(ConnCacheEntry *entry)
915 : : {
916 : 2336 : int curlevel = GetCurrentTransactionNestLevel();
917 : :
918 : : /*
919 : : * If the current local (sub)transaction is read-only, set the topmost
920 : : * read-only local transaction's nesting level if we haven't yet.
921 : : *
922 : : * Note: once it's set, it's retained until the topmost read-only local
923 : : * transaction is committed/aborted (see pgfdw_xact_callback and
924 : : * pgfdw_subxact_callback).
925 : : */
190 efujita@postgresql.o 926 [ + + ]: 2336 : if (XactReadOnly)
927 : : {
928 [ + + ]: 10 : if (read_only_level == 0)
929 : 9 : read_only_level = GetTopReadOnlyTransactionNestLevel();
930 [ - + ]: 10 : Assert(read_only_level > 0);
931 : : }
932 : : else
933 [ - + ]: 2326 : Assert(read_only_level == 0);
934 : :
935 : : /*
936 : : * Start main transaction if we haven't yet; otherwise, change the current
937 : : * remote (sub)transaction's read/write mode if needed.
938 : : */
4981 tgl@sss.pgh.pa.us 939 [ + + ]: 2336 : if (entry->xact_depth <= 0)
940 : : {
941 : : /*
942 : : * This is the case when we haven't yet started a main transaction.
943 : : */
944 : : StringInfoData sql;
190 efujita@postgresql.o 945 : 808 : bool ro = (read_only_level == 1);
946 : :
4981 tgl@sss.pgh.pa.us 947 [ - + ]: 808 : elog(DEBUG3, "starting remote transaction on connection %p",
948 : : entry->conn);
949 : :
190 efujita@postgresql.o 950 : 808 : initStringInfo(&sql);
951 : 808 : appendStringInfoString(&sql, "START TRANSACTION ISOLATION LEVEL ");
4981 tgl@sss.pgh.pa.us 952 [ + + ]: 808 : if (IsolationIsSerializable())
190 efujita@postgresql.o 953 : 3 : appendStringInfoString(&sql, "SERIALIZABLE");
954 : : else
955 : 805 : appendStringInfoString(&sql, "REPEATABLE READ");
956 [ + + ]: 808 : if (ro)
957 : 3 : appendStringInfoString(&sql, " READ ONLY");
7 958 [ + + + - ]: 808 : if (XactDeferrable && PQserverVersion(entry->conn) >= 90100)
190 959 : 2 : appendStringInfoString(&sql, " DEFERRABLE");
3414 rhaas@postgresql.org 960 : 808 : entry->changing_xact_state = true;
190 efujita@postgresql.o 961 : 808 : do_sql_command(entry->conn, sql.data);
4981 tgl@sss.pgh.pa.us 962 : 807 : entry->xact_depth = 1;
190 efujita@postgresql.o 963 [ + + ]: 807 : if (ro)
964 : : {
965 [ - + ]: 3 : Assert(!entry->xact_read_only);
966 : 3 : entry->xact_read_only = true;
967 : : }
3414 rhaas@postgresql.org 968 : 807 : entry->changing_xact_state = false;
969 : : }
190 efujita@postgresql.o 970 [ + + ]: 1528 : else if (!entry->xact_read_only)
971 : : {
972 : : /*
973 : : * The remote (sub)transaction has been opened in read-write mode.
974 : : */
975 [ + + - + ]: 1527 : Assert(read_only_level == 0 ||
976 : : entry->xact_depth <= read_only_level);
977 : :
978 : : /*
979 : : * If its nesting depth matches read_only_level, it means that the
980 : : * local read-write (sub)transaction that started it has changed to
981 : : * read-only after that; in which case change it to read-only as well.
982 : : * Otherwise, the local (sub)transaction is still read-write, so there
983 : : * is no need to do anything.
984 : : */
985 [ + + ]: 1527 : if (entry->xact_depth == read_only_level)
986 : : {
987 : 4 : entry->changing_xact_state = true;
7 988 : 4 : do_sql_command(entry->conn, "SET TRANSACTION READ ONLY");
190 989 : 4 : entry->xact_read_only = true;
990 : 4 : entry->changing_xact_state = false;
991 : : }
992 : : }
993 : : else
994 : : {
995 : : /*
996 : : * The remote (sub)transaction has been opened in read-only mode.
997 : : */
998 [ + - - + ]: 1 : Assert(read_only_level > 0 &&
999 : : entry->xact_depth >= read_only_level);
1000 : :
1001 : : /*
1002 : : * The local read-only (sub)transaction that started it is guaranteed
1003 : : * to be still read-only (see check_transaction_read_only), so there
1004 : : * is no need to do anything.
1005 : : */
1006 : : }
1007 : :
1008 : : /*
1009 : : * If we're in a subtransaction, stack up savepoints to match our level.
1010 : : * This ensures we can rollback just the desired effects when a
1011 : : * subtransaction aborts.
1012 : : */
4981 tgl@sss.pgh.pa.us 1013 [ + + ]: 2356 : while (entry->xact_depth < curlevel)
1014 : : {
1015 : : StringInfoData sql;
190 efujita@postgresql.o 1016 : 22 : bool ro = (entry->xact_depth + 1 == read_only_level);
1017 : :
1018 : 22 : initStringInfo(&sql);
1019 : 22 : appendStringInfo(&sql, "SAVEPOINT s%d", entry->xact_depth + 1);
1020 [ + + ]: 22 : if (ro)
7 1021 : 2 : appendStringInfoString(&sql, "; SET TRANSACTION READ ONLY");
3414 rhaas@postgresql.org 1022 : 22 : entry->changing_xact_state = true;
190 efujita@postgresql.o 1023 : 22 : do_sql_command(entry->conn, sql.data);
4981 tgl@sss.pgh.pa.us 1024 : 21 : entry->xact_depth++;
190 efujita@postgresql.o 1025 [ + + ]: 21 : if (ro)
1026 : : {
1027 [ - + ]: 2 : Assert(!entry->xact_read_only);
1028 : 2 : entry->xact_read_only = true;
1029 : : }
3414 rhaas@postgresql.org 1030 : 21 : entry->changing_xact_state = false;
1031 : : }
4981 tgl@sss.pgh.pa.us 1032 : 2334 : }
1033 : :
1034 : : /*
1035 : : * Release connection reference count created by calling GetConnection.
1036 : : */
1037 : : void
1038 : 2259 : ReleaseConnection(PGconn *conn)
1039 : : {
1040 : : /*
1041 : : * Currently, we don't actually track connection references because all
1042 : : * cleanup is managed on a transaction or subtransaction basis instead. So
1043 : : * there's nothing to do here.
1044 : : */
1045 : 2259 : }
1046 : :
1047 : : /*
1048 : : * Assign a "unique" number for a cursor.
1049 : : *
1050 : : * These really only need to be unique per connection within a transaction.
1051 : : * For the moment we ignore the per-connection point and assign them across
1052 : : * all connections in the transaction, but we ask for the connection to be
1053 : : * supplied in case we want to refine that.
1054 : : *
1055 : : * Note that even if wraparound happens in a very long transaction, actual
1056 : : * collisions are highly improbable; just be sure to use %u not %d to print.
1057 : : */
1058 : : unsigned int
1059 : 604 : GetCursorNumber(PGconn *conn)
1060 : : {
1061 : 604 : return ++cursor_number;
1062 : : }
1063 : :
1064 : : /*
1065 : : * Assign a "unique" number for a prepared statement.
1066 : : *
1067 : : * This works much like GetCursorNumber, except that we never reset the counter
1068 : : * within a session. That's because we can't be 100% sure we've gotten rid
1069 : : * of all prepared statements on all connections, and it's not really worth
1070 : : * increasing the risk of prepared-statement name collisions by resetting.
1071 : : */
1072 : : unsigned int
4964 1073 : 190 : GetPrepStmtNumber(PGconn *conn)
1074 : : {
1075 : 190 : return ++prep_stmt_number;
1076 : : }
1077 : :
1078 : : /*
1079 : : * Submit a query and wait for the result.
1080 : : *
1081 : : * Since we don't use non-blocking mode, this can't process interrupts while
1082 : : * pushing the query text to the server. That risk is relatively small, so we
1083 : : * ignore that for now.
1084 : : *
1085 : : * Caller is responsible for the error handling on the result.
1086 : : */
1087 : : PGresult *
2021 efujita@postgresql.o 1088 : 4328 : pgfdw_exec_query(PGconn *conn, const char *query, PgFdwConnState *state)
1089 : : {
1090 : : /* First, process a pending asynchronous request, if any. */
1091 [ + + + + ]: 4328 : if (state && state->pendingAreq)
1092 : 5 : process_pending_request(state->pendingAreq);
1093 : :
3826 rhaas@postgresql.org 1094 [ + + ]: 4328 : if (!PQsendQuery(conn, query))
1008 noah@leadboat.com 1095 : 1 : return NULL;
1096 : 4327 : return pgfdw_get_result(conn);
1097 : : }
1098 : :
1099 : : /*
1100 : : * Wrap libpqsrv_get_result_last(), adding wait event.
1101 : : *
1102 : : * Caller is responsible for the error handling on the result.
1103 : : */
1104 : : PGresult *
1105 : 8722 : pgfdw_get_result(PGconn *conn)
1106 : : {
1107 : 8722 : return libpqsrv_get_result_last(conn, pgfdw_we_get_result);
1108 : : }
1109 : :
1110 : : /*
1111 : : * Report an error we got from the remote server.
1112 : : *
1113 : : * Callers should use pgfdw_report_error() to throw an error, or use
1114 : : * pgfdw_report() for lesser message levels. (We make this distinction
1115 : : * so that pgfdw_report_error() can be marked noreturn.)
1116 : : *
1117 : : * res: PGresult containing the error (might be NULL)
1118 : : * conn: connection we did the query on
1119 : : * sql: NULL, or text of remote command we tried to execute
1120 : : *
1121 : : * If "res" is not NULL, it'll be PQclear'ed here (unless we throw error,
1122 : : * in which case memory context cleanup will clear it eventually).
1123 : : *
1124 : : * Note: callers that choose not to throw ERROR for a remote error are
1125 : : * responsible for making sure that the associated ConnCacheEntry gets
1126 : : * marked with have_error = true.
1127 : : */
1128 : : void
440 tgl@sss.pgh.pa.us 1129 : 27 : pgfdw_report_error(PGresult *res, PGconn *conn, const char *sql)
1130 : : {
1131 : 27 : pgfdw_report_internal(ERROR, res, conn, sql);
440 tgl@sss.pgh.pa.us 1132 :UBC 0 : pg_unreachable();
1133 : : }
1134 : :
1135 : : void
440 tgl@sss.pgh.pa.us 1136 :CBC 3 : pgfdw_report(int elevel, PGresult *res, PGconn *conn, const char *sql)
1137 : : {
1138 [ - + ]: 3 : Assert(elevel < ERROR); /* use pgfdw_report_error for that */
1139 : 3 : pgfdw_report_internal(elevel, res, conn, sql);
1140 : 3 : }
1141 : :
1142 : : static void
1143 : 30 : pgfdw_report_internal(int elevel, PGresult *res, PGconn *conn,
1144 : : const char *sql)
1145 : : {
444 1146 : 30 : char *diag_sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1147 : 30 : char *message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1148 : 30 : char *message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL);
1149 : 30 : char *message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT);
1150 : 30 : char *message_context = PQresultErrorField(res, PG_DIAG_CONTEXT);
1151 : : int sqlstate;
1152 : :
1153 [ + + ]: 30 : if (diag_sqlstate)
1154 : 23 : sqlstate = MAKE_SQLSTATE(diag_sqlstate[0],
1155 : : diag_sqlstate[1],
1156 : : diag_sqlstate[2],
1157 : : diag_sqlstate[3],
1158 : : diag_sqlstate[4]);
1159 : : else
1160 : 7 : sqlstate = ERRCODE_CONNECTION_FAILURE;
1161 : :
1162 : : /*
1163 : : * If we don't get a message from the PGresult, try the PGconn. This is
1164 : : * needed because for connection-level failures, PQgetResult may just
1165 : : * return NULL, not a PGresult at all.
1166 : : */
1167 [ + + ]: 30 : if (message_primary == NULL)
1168 : 7 : message_primary = pchomp(PQerrorMessage(conn));
1169 : :
1170 [ + - + - : 30 : ereport(elevel,
+ - + + +
+ + + +
- ]
1171 : : (errcode(sqlstate),
1172 : : (message_primary != NULL && message_primary[0] != '\0') ?
1173 : : errmsg_internal("%s", message_primary) :
1174 : : errmsg("could not obtain message string for remote error"),
1175 : : message_detail ? errdetail_internal("%s", message_detail) : 0,
1176 : : message_hint ? errhint("%s", message_hint) : 0,
1177 : : message_context ? errcontext("%s", message_context) : 0,
1178 : : sql ? errcontext("remote SQL command: %s", sql) : 0));
1179 : 3 : PQclear(res);
4981 1180 : 3 : }
1181 : :
1182 : : /*
1183 : : * pgfdw_xact_callback --- cleanup at main-transaction end.
1184 : : *
1185 : : * This runs just late enough that it must not enter user-defined code
1186 : : * locally. (Entering such code on the remote side is fine. Its remote
1187 : : * COMMIT TRANSACTION may run deferred triggers.)
1188 : : */
1189 : : static void
1190 : 4514 : pgfdw_xact_callback(XactEvent event, void *arg)
1191 : : {
1192 : : HASH_SEQ_STATUS scan;
1193 : : ConnCacheEntry *entry;
1691 efujita@postgresql.o 1194 : 4514 : List *pending_entries = NIL;
1285 1195 : 4514 : List *cancel_requested = NIL;
1196 : :
1197 : : /* Quick exit if no connections were touched in this transaction. */
4981 tgl@sss.pgh.pa.us 1198 [ + + ]: 4514 : if (!xact_got_connection)
1199 : 3739 : return;
1200 : :
1201 : : /*
1202 : : * If we are called for pre-commit cleanup, ensure read_only_level is set
1203 : : * for later processing. Note that we need to do this because the local
1204 : : * transaction may have become read-only since the last remote operation.
1205 : : */
7 efujita@postgresql.o 1206 [ + - + + ]: 775 : if (event == XACT_EVENT_PARALLEL_PRE_COMMIT ||
1207 : : event == XACT_EVENT_PRE_COMMIT)
1208 : : {
1209 [ + + ]: 710 : if (XactReadOnly)
1210 : : {
1211 [ + + ]: 3 : if (read_only_level == 0)
1212 : 1 : read_only_level = 1;
1213 [ - + ]: 3 : Assert(read_only_level == 1);
1214 : : }
1215 : : else
1216 [ - + ]: 707 : Assert(read_only_level == 0);
1217 : : }
1218 : :
1219 : : /*
1220 : : * Scan all connection cache entries to find open remote transactions, and
1221 : : * close them.
1222 : : */
4981 tgl@sss.pgh.pa.us 1223 : 775 : hash_seq_init(&scan, ConnectionHash);
1224 [ + + ]: 4095 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1225 : : {
1226 : : PGresult *res;
1227 : :
1228 : : /* Ignore cache entry if no open connection right now */
4634 1229 [ + + ]: 3322 : if (entry->conn == NULL)
4981 1230 : 1929 : continue;
1231 : :
1232 : : /* If it has an open remote transaction, try to close it */
4634 1233 [ + + ]: 1393 : if (entry->xact_depth > 0)
1234 : : {
1235 : : char sql[100];
1236 : :
1237 [ - + ]: 809 : elog(DEBUG3, "closing remote transaction on connection %p",
1238 : : entry->conn);
1239 : :
1240 [ + + - + : 809 : switch (event)
- ]
1241 : : {
4183 rhaas@postgresql.org 1242 : 747 : case XACT_EVENT_PARALLEL_PRE_COMMIT:
1243 : : case XACT_EVENT_PRE_COMMIT:
1244 : :
1245 : : /*
1246 : : * If abort cleanup previously failed for this connection,
1247 : : * we can't issue any more commands against it.
1248 : : */
3414 1249 : 747 : pgfdw_reject_incomplete_xact_state_change(entry);
1250 : :
1251 : : /* Commit all remote transactions during pre-commit */
7 efujita@postgresql.o 1252 [ + + + + ]: 747 : CONSTRUCT_COMMIT_COMMAND(sql, entry);
3414 rhaas@postgresql.org 1253 : 747 : entry->changing_xact_state = true;
1691 efujita@postgresql.o 1254 [ + + ]: 747 : if (entry->parallel_commit)
1255 : : {
7 1256 : 16 : do_sql_command_begin(entry->conn, sql);
1691 1257 : 16 : pending_entries = lappend(pending_entries, entry);
1258 : 20 : continue;
1259 : : }
7 1260 : 731 : do_sql_command(entry->conn, sql);
1261 [ + + - + ]: 730 : if ((read_only_level > 0) && !entry->xact_read_only)
7 efujita@postgresql.o 1262 :UBC 0 : entry->xact_read_only = true;
3414 rhaas@postgresql.org 1263 :CBC 730 : entry->changing_xact_state = false;
1264 : :
1265 : : /*
1266 : : * If there were any errors in subtransactions, and we
1267 : : * made prepared statements, do a DEALLOCATE ALL to make
1268 : : * sure we get rid of all prepared statements. This is
1269 : : * annoying and not terribly bulletproof, but it's
1270 : : * probably not worth trying harder.
1271 : : *
1272 : : * DEALLOCATE ALL only exists in 8.3 and later, so this
1273 : : * constrains how old a server postgres_fdw can
1274 : : * communicate with. We intentionally ignore errors in
1275 : : * the DEALLOCATE, so that we can hobble along to some
1276 : : * extent with older servers (leaking prepared statements
1277 : : * as we go; but we don't really support update operations
1278 : : * pre-8.3 anyway).
1279 : : */
4964 tgl@sss.pgh.pa.us 1280 [ + + - + ]: 730 : if (entry->have_prep_stmt && entry->have_error)
1281 : : {
1008 noah@leadboat.com 1282 :UBC 0 : res = pgfdw_exec_query(entry->conn, "DEALLOCATE ALL",
1283 : : NULL);
4964 tgl@sss.pgh.pa.us 1284 : 0 : PQclear(res);
1285 : : }
4964 tgl@sss.pgh.pa.us 1286 :CBC 730 : entry->have_prep_stmt = false;
1287 : 730 : entry->have_error = false;
4634 1288 : 730 : break;
1289 : 1 : case XACT_EVENT_PRE_PREPARE:
1290 : :
1291 : : /*
1292 : : * We disallow any remote transactions, since it's not
1293 : : * very reasonable to hold them open until the prepared
1294 : : * transaction is committed. For the moment, throw error
1295 : : * unconditionally; later we might allow read-only cases.
1296 : : * Note that the error will cause us to come right back
1297 : : * here with event == XACT_EVENT_ABORT, so we'll clean up
1298 : : * the connection state at that point.
1299 : : */
1300 [ + - ]: 1 : ereport(ERROR,
1301 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1302 : : errmsg("cannot PREPARE a transaction that has operated on postgres_fdw foreign tables")));
1303 : : break;
4183 rhaas@postgresql.org 1304 :UBC 0 : case XACT_EVENT_PARALLEL_COMMIT:
1305 : : case XACT_EVENT_COMMIT:
1306 : : case XACT_EVENT_PREPARE:
1307 : : /* Pre-commit should have closed the open transaction */
4634 tgl@sss.pgh.pa.us 1308 [ # # ]: 0 : elog(ERROR, "missed cleaning up connection during pre-commit");
1309 : : break;
4183 rhaas@postgresql.org 1310 :CBC 61 : case XACT_EVENT_PARALLEL_ABORT:
1311 : : case XACT_EVENT_ABORT:
1312 : : /* Rollback all remote transactions during abort */
1285 efujita@postgresql.o 1313 [ + + ]: 61 : if (entry->parallel_abort)
1314 : : {
1315 [ + - ]: 4 : if (pgfdw_abort_cleanup_begin(entry, true,
1316 : : &pending_entries,
1317 : : &cancel_requested))
1318 : 4 : continue;
1319 : : }
1320 : : else
1321 : 57 : pgfdw_abort_cleanup(entry, true);
4634 tgl@sss.pgh.pa.us 1322 : 57 : break;
1323 : : }
1324 : : }
1325 : :
1326 : : /* Reset state to show we're out of a transaction */
1691 efujita@postgresql.o 1327 : 1371 : pgfdw_reset_xact_state(entry, true);
1328 : : }
1329 : :
1330 : : /* If there are any pending connections, finish cleaning them up */
1285 1331 [ + + - + ]: 773 : if (pending_entries || cancel_requested)
1332 : : {
1333 [ + - + + ]: 15 : if (event == XACT_EVENT_PARALLEL_PRE_COMMIT ||
1334 : : event == XACT_EVENT_PRE_COMMIT)
1335 : : {
1336 [ - + ]: 13 : Assert(cancel_requested == NIL);
1337 : 13 : pgfdw_finish_pre_commit_cleanup(pending_entries);
1338 : : }
1339 : : else
1340 : : {
1341 [ + - - + ]: 2 : Assert(event == XACT_EVENT_PARALLEL_ABORT ||
1342 : : event == XACT_EVENT_ABORT);
1343 : 2 : pgfdw_finish_abort_cleanup(pending_entries, cancel_requested,
1344 : : true);
1345 : : }
1346 : : }
1347 : :
1348 : : /*
1349 : : * Regardless of the event type, we can now mark ourselves as out of the
1350 : : * transaction. (Note: if we are here during PRE_COMMIT or PRE_PREPARE,
1351 : : * this saves a useless scan of the hashtable during COMMIT or PREPARE.)
1352 : : */
4981 tgl@sss.pgh.pa.us 1353 : 773 : xact_got_connection = false;
1354 : :
1355 : : /* Also reset cursor numbering for next transaction */
1356 : 773 : cursor_number = 0;
1357 : :
1358 : : /* Likewise for read_only_level */
190 efujita@postgresql.o 1359 : 773 : read_only_level = 0;
1360 : : }
1361 : :
1362 : : /*
1363 : : * pgfdw_subxact_callback --- cleanup at subtransaction end.
1364 : : */
1365 : : static void
4981 tgl@sss.pgh.pa.us 1366 : 72 : pgfdw_subxact_callback(SubXactEvent event, SubTransactionId mySubid,
1367 : : SubTransactionId parentSubid, void *arg)
1368 : : {
1369 : : HASH_SEQ_STATUS scan;
1370 : : ConnCacheEntry *entry;
1371 : : int curlevel;
1691 efujita@postgresql.o 1372 : 72 : List *pending_entries = NIL;
1285 1373 : 72 : List *cancel_requested = NIL;
1374 : :
1375 : : /* Nothing to do at subxact start, nor after commit. */
4981 tgl@sss.pgh.pa.us 1376 [ + + + + ]: 72 : if (!(event == SUBXACT_EVENT_PRE_COMMIT_SUB ||
1377 : : event == SUBXACT_EVENT_ABORT_SUB))
1378 : 43 : return;
1379 : :
1380 : : /* Quick exit if no connections were touched in this transaction. */
1381 [ - + ]: 29 : if (!xact_got_connection)
4981 tgl@sss.pgh.pa.us 1382 :UBC 0 : return;
1383 : :
1384 : : /*
1385 : : * Scan all connection cache entries to find open remote subtransactions
1386 : : * of the current level, and close them.
1387 : : */
4981 tgl@sss.pgh.pa.us 1388 :CBC 29 : curlevel = GetCurrentTransactionNestLevel();
1389 : 29 : hash_seq_init(&scan, ConnectionHash);
1390 [ + + ]: 242 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1391 : : {
1392 : : char sql[100];
1393 : :
1394 : : /*
1395 : : * We only care about connections with open remote subtransactions of
1396 : : * the current level.
1397 : : */
1398 [ + + + + ]: 213 : if (entry->conn == NULL || entry->xact_depth < curlevel)
1399 : 198 : continue;
1400 : :
1401 [ - + ]: 21 : if (entry->xact_depth > curlevel)
4981 tgl@sss.pgh.pa.us 1402 [ # # ]:UBC 0 : elog(ERROR, "missed cleaning up remote subtransaction at level %d",
1403 : : entry->xact_depth);
1404 : :
4981 tgl@sss.pgh.pa.us 1405 [ + + ]:CBC 21 : if (event == SUBXACT_EVENT_PRE_COMMIT_SUB)
1406 : : {
1407 : : /*
1408 : : * If abort cleanup previously failed for this connection, we
1409 : : * can't issue any more commands against it.
1410 : : */
3414 rhaas@postgresql.org 1411 : 7 : pgfdw_reject_incomplete_xact_state_change(entry);
1412 : :
1413 : : /* Commit all remote subtransactions during pre-commit */
4981 tgl@sss.pgh.pa.us 1414 : 7 : snprintf(sql, sizeof(sql), "RELEASE SAVEPOINT s%d", curlevel);
3414 rhaas@postgresql.org 1415 : 7 : entry->changing_xact_state = true;
1691 efujita@postgresql.o 1416 [ + + ]: 7 : if (entry->parallel_commit)
1417 : : {
1418 : 2 : do_sql_command_begin(entry->conn, sql);
1419 : 2 : pending_entries = lappend(pending_entries, entry);
1420 : 2 : continue;
1421 : : }
4963 tgl@sss.pgh.pa.us 1422 : 5 : do_sql_command(entry->conn, sql);
3414 rhaas@postgresql.org 1423 : 5 : entry->changing_xact_state = false;
1424 : : }
1425 : : else
1426 : : {
1427 : : /* Rollback all remote subtransactions during abort */
1285 efujita@postgresql.o 1428 [ + + ]: 14 : if (entry->parallel_abort)
1429 : : {
1430 [ + - ]: 4 : if (pgfdw_abort_cleanup_begin(entry, false,
1431 : : &pending_entries,
1432 : : &cancel_requested))
1433 : 4 : continue;
1434 : : }
1435 : : else
1436 : 10 : pgfdw_abort_cleanup(entry, false);
1437 : : }
1438 : :
1439 : : /* OK, we're outta that level of subtransaction */
1691 1440 : 15 : pgfdw_reset_xact_state(entry, false);
1441 : : }
1442 : :
1443 : : /* If there are any pending connections, finish cleaning them up */
1285 1444 [ + + - + ]: 29 : if (pending_entries || cancel_requested)
1445 : : {
1446 [ + + ]: 3 : if (event == SUBXACT_EVENT_PRE_COMMIT_SUB)
1447 : : {
1448 [ - + ]: 1 : Assert(cancel_requested == NIL);
1449 : 1 : pgfdw_finish_pre_subcommit_cleanup(pending_entries, curlevel);
1450 : : }
1451 : : else
1452 : : {
1453 [ - + ]: 2 : Assert(event == SUBXACT_EVENT_ABORT_SUB);
1454 : 2 : pgfdw_finish_abort_cleanup(pending_entries, cancel_requested,
1455 : : false);
1456 : : }
1457 : : }
1458 : :
1459 : : /* If in read_only_level, reset it */
190 1460 [ + + ]: 29 : if (curlevel == read_only_level)
1461 : 3 : read_only_level = 0;
1462 : : }
1463 : :
1464 : : /*
1465 : : * Connection invalidation callback function
1466 : : *
1467 : : * After a change to a pg_foreign_server or pg_user_mapping catalog entry,
1468 : : * close connections depending on that entry immediately if current transaction
1469 : : * has not used those connections yet. Otherwise, mark those connections as
1470 : : * invalid and then make pgfdw_xact_callback() close them at the end of current
1471 : : * transaction, since they cannot be closed in the midst of the transaction
1472 : : * using them. Closed connections will be remade at the next opportunity if
1473 : : * necessary.
1474 : : *
1475 : : * Although most cache invalidation callbacks blow away all the related stuff
1476 : : * regardless of the given hashvalue, connections are expensive enough that
1477 : : * it's worth trying to avoid that.
1478 : : *
1479 : : * NB: We could avoid unnecessary disconnection more strictly by examining
1480 : : * individual option values, but it seems too much effort for the gain.
1481 : : */
1482 : : static void
236 michael@paquier.xyz 1483 : 188 : pgfdw_inval_callback(Datum arg, SysCacheIdentifier cacheid, uint32 hashvalue)
1484 : : {
1485 : : HASH_SEQ_STATUS scan;
1486 : : ConnCacheEntry *entry;
1487 : :
3370 tgl@sss.pgh.pa.us 1488 [ + + - + ]: 188 : Assert(cacheid == FOREIGNSERVEROID || cacheid == USERMAPPINGOID);
1489 : :
1490 : : /* ConnectionHash must exist already, if we're registered */
1491 : 188 : hash_seq_init(&scan, ConnectionHash);
1492 [ + + ]: 1222 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1493 : : {
1494 : : /* Ignore invalid entries */
1495 [ + + ]: 1034 : if (entry->conn == NULL)
1496 : 838 : continue;
1497 : :
1498 : : /* hashvalue == 0 means a cache reset, must clear all state */
1499 [ + - + + ]: 196 : if (hashvalue == 0 ||
1500 : 140 : (cacheid == FOREIGNSERVEROID &&
1501 [ + + + + ]: 196 : entry->server_hashvalue == hashvalue) ||
1502 : 56 : (cacheid == USERMAPPINGOID &&
1503 [ + + ]: 56 : entry->mapping_hashvalue == hashvalue))
1504 : : {
1505 : : /*
1506 : : * Close the connection immediately if it's not used yet in this
1507 : : * transaction. Otherwise mark it as invalid so that
1508 : : * pgfdw_xact_callback() can close it at the end of this
1509 : : * transaction.
1510 : : */
2114 fujii@postgresql.org 1511 [ + + ]: 59 : if (entry->xact_depth == 0)
1512 : : {
1513 [ - + ]: 56 : elog(DEBUG3, "discarding connection %p", entry->conn);
1514 : 56 : disconnect_pg_server(entry);
1515 : : }
1516 : : else
1517 : 3 : entry->invalidated = true;
1518 : : }
1519 : : }
3370 tgl@sss.pgh.pa.us 1520 : 188 : }
1521 : :
1522 : : /*
1523 : : * Raise an error if the given connection cache entry is marked as being
1524 : : * in the middle of an xact state change. This should be called at which no
1525 : : * such change is expected to be in progress; if one is found to be in
1526 : : * progress, it means that we aborted in the middle of a previous state change
1527 : : * and now don't know what the remote transaction state actually is.
1528 : : * Such connections can't safely be further used. Re-establishing the
1529 : : * connection would change the snapshot and roll back any writes already
1530 : : * performed, so that's not an option, either. Thus, we must abort.
1531 : : *
1532 : : * Note: there might be open cursors that use the connection, so even if the
1533 : : * connection cache entry is marked as such, we will retain it until abort
1534 : : * cleanup of the main transaction, to ensure such open cursors can safely
1535 : : * refer to the PGconn for the connection.
1536 : : */
1537 : : static void
3414 rhaas@postgresql.org 1538 : 3098 : pgfdw_reject_incomplete_xact_state_change(ConnCacheEntry *entry)
1539 : : {
1540 : : ForeignServer *server;
1541 : :
1542 : : /* nothing to do for inactive entries and entries of sane state */
3370 tgl@sss.pgh.pa.us 1543 [ + + + + ]: 3098 : if (entry->conn == NULL || !entry->changing_xact_state)
3414 rhaas@postgresql.org 1544 : 3096 : return;
1545 : :
1546 : : /* find server name to be shown in the message below */
2096 fujii@postgresql.org 1547 : 2 : server = GetForeignServer(entry->serverid);
1548 : :
3414 rhaas@postgresql.org 1549 [ + - ]: 2 : ereport(ERROR,
1550 : : (errcode(ERRCODE_CONNECTION_EXCEPTION),
1551 : : errmsg("connection to server \"%s\" cannot be used due to abort cleanup failure",
1552 : : server->servername)));
1553 : : }
1554 : :
1555 : : /*
1556 : : * Reset state to show we're out of a (sub)transaction.
1557 : : */
1558 : : static void
1691 efujita@postgresql.o 1559 : 1412 : pgfdw_reset_xact_state(ConnCacheEntry *entry, bool toplevel)
1560 : : {
1561 [ + + ]: 1412 : if (toplevel)
1562 : : {
1563 : : /* Reset state to show we're out of a transaction */
1564 : 1391 : entry->xact_depth = 0;
1565 : :
1566 : : /* Reset xact r/o state */
190 1567 : 1391 : entry->xact_read_only = false;
1568 : :
1569 : : /*
1570 : : * If the connection isn't in a good idle state, it is marked as
1571 : : * invalid or keep_connections option of its server is disabled, then
1572 : : * discard it to recover. Next GetConnection will open a new
1573 : : * connection.
1574 : : */
1691 1575 [ + + + - ]: 2778 : if (PQstatus(entry->conn) != CONNECTION_OK ||
1576 : 1387 : PQtransactionStatus(entry->conn) != PQTRANS_IDLE ||
1577 [ + + ]: 1387 : entry->changing_xact_state ||
1578 [ + + ]: 1386 : entry->invalidated ||
1579 [ + + ]: 1384 : !entry->keep_connections)
1580 : : {
1581 [ - + ]: 8 : elog(DEBUG3, "discarding connection %p", entry->conn);
1582 : 8 : disconnect_pg_server(entry);
1583 : : }
1584 : : }
1585 : : else
1586 : : {
1587 : : /* Reset state to show we're out of a subtransaction */
1588 : 21 : entry->xact_depth--;
1589 : :
1590 : : /* If in read_only_level, reset xact r/o state */
190 1591 [ + + ]: 21 : if (entry->xact_depth + 1 == read_only_level)
1592 : 4 : entry->xact_read_only = false;
1593 : : }
1691 1594 : 1412 : }
1595 : :
1596 : : /*
1597 : : * Cancel the currently-in-progress query (whose query text we do not have)
1598 : : * and ignore the result. Returns true if we successfully cancel the query
1599 : : * and discard any pending result, and false if not.
1600 : : *
1601 : : * It's not a huge problem if we throw an ERROR here, but if we get into error
1602 : : * recursion trouble, we'll end up slamming the connection shut, which will
1603 : : * necessitate failing the entire toplevel transaction even if subtransactions
1604 : : * were used. Try to use WARNING where we can.
1605 : : *
1606 : : * XXX: if the query was one sent by fetch_more_data_begin(), we could get the
1607 : : * query text from the pendingAreq saved in the per-connection state, then
1608 : : * report the query using it.
1609 : : */
1610 : : static bool
3414 rhaas@postgresql.org 1611 : 2 : pgfdw_cancel_query(PGconn *conn)
1612 : : {
658 tgl@sss.pgh.pa.us 1613 : 2 : TimestampTz now = GetCurrentTimestamp();
1614 : : TimestampTz endtime;
1615 : : TimestampTz retrycanceltime;
1616 : :
1617 : : /*
1618 : : * If it takes too long to cancel the query and discard the result, assume
1619 : : * the connection is dead.
1620 : : */
1621 : 2 : endtime = TimestampTzPlusMilliseconds(now, CONNECTION_CLEANUP_TIMEOUT);
1622 : :
1623 : : /*
1624 : : * Also, lose patience and re-issue the cancel request after a little bit.
1625 : : * (This serves to close some race conditions.)
1626 : : */
1627 : 2 : retrycanceltime = TimestampTzPlusMilliseconds(now, RETRY_CANCEL_TIMEOUT);
1628 : :
928 alvherre@alvh.no-ip. 1629 [ - + ]: 2 : if (!pgfdw_cancel_query_begin(conn, endtime))
1285 efujita@postgresql.o 1630 :UBC 0 : return false;
658 tgl@sss.pgh.pa.us 1631 :CBC 2 : return pgfdw_cancel_query_end(conn, endtime, retrycanceltime, false);
1632 : : }
1633 : :
1634 : : /*
1635 : : * Submit a cancel request to the given connection, waiting only until
1636 : : * the given time.
1637 : : *
1638 : : * We sleep interruptibly until we receive confirmation that the cancel
1639 : : * request has been accepted, and if it is, return true; if the timeout
1640 : : * lapses without that, or the request fails for whatever reason, return
1641 : : * false.
1642 : : */
1643 : : static bool
928 alvherre@alvh.no-ip. 1644 : 2 : pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime)
1645 : : {
920 1646 : 2 : const char *errormsg = libpqsrv_cancel(conn, endtime);
1647 : :
928 1648 [ - + ]: 2 : if (errormsg != NULL)
928 alvherre@alvh.no-ip. 1649 [ # # ]:UBC 0 : ereport(WARNING,
1650 : : errcode(ERRCODE_CONNECTION_FAILURE),
1651 : : errmsg("could not send cancel request: %s", errormsg));
1652 : :
928 alvherre@alvh.no-ip. 1653 :CBC 2 : return errormsg == NULL;
1654 : : }
1655 : :
1656 : : static bool
658 tgl@sss.pgh.pa.us 1657 : 2 : pgfdw_cancel_query_end(PGconn *conn, TimestampTz endtime,
1658 : : TimestampTz retrycanceltime, bool consume_input)
1659 : : {
1660 : : PGresult *result;
1661 : : bool timed_out;
1662 : :
1663 : : /*
1664 : : * If requested, consume whatever data is available from the socket. (Note
1665 : : * that if all data is available, this allows pgfdw_get_cleanup_result to
1666 : : * call PQgetResult without forcing the overhead of WaitLatchOrSocket,
1667 : : * which would be large compared to the overhead of PQconsumeInput.)
1668 : : */
1285 efujita@postgresql.o 1669 [ - + - - ]: 2 : if (consume_input && !PQconsumeInput(conn))
1670 : : {
1285 efujita@postgresql.o 1671 [ # # ]:UBC 0 : ereport(WARNING,
1672 : : (errcode(ERRCODE_CONNECTION_FAILURE),
1673 : : errmsg("could not get result of cancel request: %s",
1674 : : pchomp(PQerrorMessage(conn)))));
1675 : 0 : return false;
1676 : : }
1677 : :
1678 : : /* Get and discard the result of the query. */
658 tgl@sss.pgh.pa.us 1679 [ - + ]:CBC 2 : if (pgfdw_get_cleanup_result(conn, endtime, retrycanceltime,
1680 : : &result, &timed_out))
1681 : : {
1769 fujii@postgresql.org 1682 [ # # ]:UBC 0 : if (timed_out)
1683 [ # # ]: 0 : ereport(WARNING,
1684 : : (errmsg("could not get result of cancel request due to timeout")));
1685 : : else
1686 [ # # ]: 0 : ereport(WARNING,
1687 : : (errcode(ERRCODE_CONNECTION_FAILURE),
1688 : : errmsg("could not get result of cancel request: %s",
1689 : : pchomp(PQerrorMessage(conn)))));
1690 : :
3414 rhaas@postgresql.org 1691 : 0 : return false;
1692 : : }
3414 rhaas@postgresql.org 1693 :CBC 2 : PQclear(result);
1694 : :
1695 : 2 : return true;
1696 : : }
1697 : :
1698 : : /*
1699 : : * Submit a query during (sub)abort cleanup and wait up to 30 seconds for the
1700 : : * result. If the query is executed without error, the return value is true.
1701 : : * If the query is executed successfully but returns an error, the return
1702 : : * value is true if and only if ignore_errors is set. If the query can't be
1703 : : * sent or times out, the return value is false.
1704 : : *
1705 : : * It's not a huge problem if we throw an ERROR here, but if we get into error
1706 : : * recursion trouble, we'll end up slamming the connection shut, which will
1707 : : * necessitate failing the entire toplevel transaction even if subtransactions
1708 : : * were used. Try to use WARNING where we can.
1709 : : */
1710 : : static bool
1711 : 88 : pgfdw_exec_cleanup_query(PGconn *conn, const char *query, bool ignore_errors)
1712 : : {
1713 : : TimestampTz endtime;
1714 : :
1715 : : /*
1716 : : * If it takes too long to execute a cleanup query, assume the connection
1717 : : * is dead. It's fairly likely that this is why we aborted in the first
1718 : : * place (e.g. statement timeout, user cancel), so the timeout shouldn't
1719 : : * be too long.
1720 : : */
1285 efujita@postgresql.o 1721 : 88 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
1722 : : CONNECTION_CLEANUP_TIMEOUT);
1723 : :
1724 [ - + ]: 88 : if (!pgfdw_exec_cleanup_query_begin(conn, query))
1285 efujita@postgresql.o 1725 :UBC 0 : return false;
1285 efujita@postgresql.o 1726 :CBC 88 : return pgfdw_exec_cleanup_query_end(conn, query, endtime,
1727 : : false, ignore_errors);
1728 : : }
1729 : :
1730 : : static bool
1731 : 100 : pgfdw_exec_cleanup_query_begin(PGconn *conn, const char *query)
1732 : : {
921 1733 [ - + ]: 100 : Assert(query != NULL);
1734 : :
1735 : : /*
1736 : : * Submit a query. Since we don't use non-blocking mode, this also can
1737 : : * block. But its risk is relatively small, so we ignore that for now.
1738 : : */
3414 rhaas@postgresql.org 1739 [ - + ]: 100 : if (!PQsendQuery(conn, query))
1740 : : {
440 tgl@sss.pgh.pa.us 1741 :UBC 0 : pgfdw_report(WARNING, NULL, conn, query);
3414 rhaas@postgresql.org 1742 : 0 : return false;
1743 : : }
1744 : :
1285 efujita@postgresql.o 1745 :CBC 100 : return true;
1746 : : }
1747 : :
1748 : : static bool
1749 : 100 : pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query,
1750 : : TimestampTz endtime, bool consume_input,
1751 : : bool ignore_errors)
1752 : : {
1753 : : PGresult *result;
1754 : : bool timed_out;
1755 : :
921 1756 [ - + ]: 100 : Assert(query != NULL);
1757 : :
1758 : : /*
1759 : : * If requested, consume whatever data is available from the socket. (Note
1760 : : * that if all data is available, this allows pgfdw_get_cleanup_result to
1761 : : * call PQgetResult without forcing the overhead of WaitLatchOrSocket,
1762 : : * which would be large compared to the overhead of PQconsumeInput.)
1763 : : */
1285 1764 [ + + - + ]: 100 : if (consume_input && !PQconsumeInput(conn))
1765 : : {
440 tgl@sss.pgh.pa.us 1766 :UBC 0 : pgfdw_report(WARNING, NULL, conn, query);
1285 efujita@postgresql.o 1767 : 0 : return false;
1768 : : }
1769 : :
1770 : : /* Get the result of the query. */
658 tgl@sss.pgh.pa.us 1771 [ + + ]:CBC 100 : if (pgfdw_get_cleanup_result(conn, endtime, endtime, &result, &timed_out))
1772 : : {
1769 fujii@postgresql.org 1773 [ - + ]: 3 : if (timed_out)
1769 fujii@postgresql.org 1774 [ # # ]:UBC 0 : ereport(WARNING,
1775 : : (errmsg("could not get query result due to timeout"),
1776 : : errcontext("remote SQL command: %s", query)));
1777 : : else
440 tgl@sss.pgh.pa.us 1778 :CBC 3 : pgfdw_report(WARNING, NULL, conn, query);
1779 : :
3414 rhaas@postgresql.org 1780 : 3 : return false;
1781 : : }
1782 : :
1783 : : /* Issue a warning if not successful. */
1784 [ - + ]: 97 : if (PQresultStatus(result) != PGRES_COMMAND_OK)
1785 : : {
440 tgl@sss.pgh.pa.us 1786 :UBC 0 : pgfdw_report(WARNING, result, conn, query);
3414 rhaas@postgresql.org 1787 : 0 : return ignore_errors;
1788 : : }
3406 tgl@sss.pgh.pa.us 1789 :CBC 97 : PQclear(result);
1790 : :
3414 rhaas@postgresql.org 1791 : 97 : return true;
1792 : : }
1793 : :
1794 : : /*
1795 : : * Get, during abort cleanup, the result of a query that is in progress.
1796 : : * This might be a query that is being interrupted by a cancel request or by
1797 : : * transaction abort, or it might be a query that was initiated as part of
1798 : : * transaction abort to get the remote side back to the appropriate state.
1799 : : *
1800 : : * endtime is the time at which we should give up and assume the remote side
1801 : : * is dead. retrycanceltime is the time at which we should issue a fresh
1802 : : * cancel request (pass the same value as endtime if this is not wanted).
1803 : : *
1804 : : * Returns true if the timeout expired or connection trouble occurred,
1805 : : * false otherwise. Sets *result except in case of a true result.
1806 : : * Sets *timed_out to true only when the timeout expired.
1807 : : */
1808 : : static bool
658 tgl@sss.pgh.pa.us 1809 : 102 : pgfdw_get_cleanup_result(PGconn *conn, TimestampTz endtime,
1810 : : TimestampTz retrycanceltime,
1811 : : PGresult **result,
1812 : : bool *timed_out)
1813 : : {
444 1814 : 102 : bool failed = false;
1815 : 102 : PGresult *last_res = NULL;
1816 : 102 : int canceldelta = RETRY_CANCEL_TIMEOUT * 2;
1817 : :
658 1818 : 102 : *result = NULL;
1769 fujii@postgresql.org 1819 : 102 : *timed_out = false;
1820 : : for (;;)
444 tgl@sss.pgh.pa.us 1821 : 114 : {
1822 : : PGresult *res;
1823 : :
1824 [ + + ]: 306 : while (PQisBusy(conn))
1825 : : {
1826 : : int wc;
1827 : 93 : TimestampTz now = GetCurrentTimestamp();
1828 : : long cur_timeout;
1829 : :
1830 : : /* If timeout has expired, give up. */
1831 [ - + ]: 93 : if (now >= endtime)
1832 : : {
444 tgl@sss.pgh.pa.us 1833 :UBC 0 : *timed_out = true;
1834 : 0 : failed = true;
1835 : 0 : goto exit;
1836 : : }
1837 : :
1838 : : /* If we need to re-issue the cancel request, do that. */
444 tgl@sss.pgh.pa.us 1839 [ - + ]:CBC 93 : if (now >= retrycanceltime)
1840 : : {
1841 : : /* We ignore failure to issue the repeated request. */
444 tgl@sss.pgh.pa.us 1842 :UBC 0 : (void) libpqsrv_cancel(conn, endtime);
1843 : :
1844 : : /* Recompute "now" in case that took measurable time. */
1845 : 0 : now = GetCurrentTimestamp();
1846 : :
1847 : : /* Adjust re-cancel timeout in increasing steps. */
1848 : 0 : retrycanceltime = TimestampTzPlusMilliseconds(now,
1849 : : canceldelta);
1850 : 0 : canceldelta += canceldelta;
1851 : : }
1852 : :
1853 : : /* If timeout has expired, give up, else get sleep time. */
444 tgl@sss.pgh.pa.us 1854 :CBC 93 : cur_timeout = TimestampDifferenceMilliseconds(now,
1855 : : Min(endtime,
1856 : : retrycanceltime));
1857 [ - + ]: 93 : if (cur_timeout <= 0)
1858 : : {
444 tgl@sss.pgh.pa.us 1859 :UBC 0 : *timed_out = true;
1860 : 0 : failed = true;
1861 : 0 : goto exit;
1862 : : }
1863 : :
1864 : : /* first time, allocate or get the custom wait event */
444 tgl@sss.pgh.pa.us 1865 [ + + ]:CBC 93 : if (pgfdw_we_cleanup_result == 0)
1866 : 2 : pgfdw_we_cleanup_result = WaitEventExtensionNew("PostgresFdwCleanupResult");
1867 : :
1868 : : /* Sleep until there's something to do */
1869 : 93 : wc = WaitLatchOrSocket(MyLatch,
1870 : : WL_LATCH_SET | WL_SOCKET_READABLE |
1871 : : WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
1872 : : PQsocket(conn),
1873 : : cur_timeout, pgfdw_we_cleanup_result);
1874 : 93 : ResetLatch(MyLatch);
1875 : :
1876 [ - + ]: 93 : CHECK_FOR_INTERRUPTS();
1877 : :
1878 : : /* Data available in socket? */
1879 [ + - ]: 93 : if (wc & WL_SOCKET_READABLE)
1880 : : {
1881 [ + + ]: 93 : if (!PQconsumeInput(conn))
1882 : : {
1883 : : /* connection trouble */
1884 : 3 : failed = true;
1885 : 3 : goto exit;
1886 : : }
1887 : : }
1888 : : }
1889 : :
1890 : 213 : res = PQgetResult(conn);
1891 [ + + ]: 213 : if (res == NULL)
1892 : 99 : break; /* query is complete */
1893 : :
1894 : 114 : PQclear(last_res);
1895 : 114 : last_res = res;
1896 : : }
1897 : 102 : exit:
1769 fujii@postgresql.org 1898 [ + + ]: 102 : if (failed)
3406 tgl@sss.pgh.pa.us 1899 : 3 : PQclear(last_res);
1900 : : else
1901 : 99 : *result = last_res;
1769 fujii@postgresql.org 1902 : 102 : return failed;
1903 : : }
1904 : :
1905 : : /*
1906 : : * Abort remote transaction or subtransaction.
1907 : : *
1908 : : * "toplevel" should be set to true if toplevel (main) transaction is
1909 : : * rollbacked, false otherwise.
1910 : : *
1911 : : * Set entry->changing_xact_state to false on success, true on failure.
1912 : : */
1913 : : static void
1662 efujita@postgresql.o 1914 : 67 : pgfdw_abort_cleanup(ConnCacheEntry *entry, bool toplevel)
1915 : : {
1916 : : char sql[100];
1917 : :
1918 : : /*
1919 : : * Don't try to clean up the connection if we're already in error
1920 : : * recursion trouble.
1921 : : */
1846 fujii@postgresql.org 1922 [ - + ]: 67 : if (in_error_recursion_trouble())
1846 fujii@postgresql.org 1923 :UBC 0 : entry->changing_xact_state = true;
1924 : :
1925 : : /*
1926 : : * If connection is already unsalvageable, don't touch it further.
1927 : : */
1846 fujii@postgresql.org 1928 [ + + ]:CBC 67 : if (entry->changing_xact_state)
1929 : 7 : return;
1930 : :
1931 : : /*
1932 : : * Mark this connection as in the process of changing transaction state.
1933 : : */
1934 : 63 : entry->changing_xact_state = true;
1935 : :
1936 : : /* Assume we might have lost track of prepared statements */
1937 : 63 : entry->have_error = true;
1938 : :
1939 : : /*
1940 : : * If a command has been submitted to the remote server by using an
1941 : : * asynchronous execution function, the command might not have yet
1942 : : * completed. Check to see if a command is still being processed by the
1943 : : * remote server, and if so, request cancellation of the command.
1944 : : */
1945 [ + + ]: 63 : if (PQtransactionStatus(entry->conn) == PQTRANS_ACTIVE &&
1946 [ - + ]: 2 : !pgfdw_cancel_query(entry->conn))
1846 fujii@postgresql.org 1947 :UBC 0 : return; /* Unable to cancel running query */
1948 : :
1285 efujita@postgresql.o 1949 [ + + ]:CBC 63 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
1846 fujii@postgresql.org 1950 [ + + ]: 63 : if (!pgfdw_exec_cleanup_query(entry->conn, sql, false))
1662 efujita@postgresql.o 1951 : 3 : return; /* Unable to abort remote (sub)transaction */
1952 : :
1846 fujii@postgresql.org 1953 [ + + ]: 60 : if (toplevel)
1954 : : {
1955 [ + + + - ]: 52 : if (entry->have_prep_stmt && entry->have_error &&
1956 [ - + ]: 25 : !pgfdw_exec_cleanup_query(entry->conn,
1957 : : "DEALLOCATE ALL",
1958 : : true))
1846 fujii@postgresql.org 1959 :UBC 0 : return; /* Trouble clearing prepared statements */
1960 : :
1846 fujii@postgresql.org 1961 :CBC 52 : entry->have_prep_stmt = false;
1962 : 52 : entry->have_error = false;
1963 : : }
1964 : :
1965 : : /*
1966 : : * If pendingAreq of the per-connection state is not NULL, it means that
1967 : : * an asynchronous fetch begun by fetch_more_data_begin() was not done
1968 : : * successfully and thus the per-connection state was not reset in
1969 : : * fetch_more_data(); in that case reset the per-connection state here.
1970 : : */
1725 efujita@postgresql.o 1971 [ + + ]: 60 : if (entry->state.pendingAreq)
1725 efujita@postgresql.o 1972 :GBC 1 : memset(&entry->state, 0, sizeof(entry->state));
1973 : :
1974 : : /* Disarm changing_xact_state if it all worked */
1846 fujii@postgresql.org 1975 :CBC 60 : entry->changing_xact_state = false;
1976 : : }
1977 : :
1978 : : /*
1979 : : * Like pgfdw_abort_cleanup, submit an abort command or cancel request, but
1980 : : * don't wait for the result.
1981 : : *
1982 : : * Returns true if the abort command or cancel request is successfully issued,
1983 : : * false otherwise. If the abort command is successfully issued, the given
1984 : : * connection cache entry is appended to *pending_entries. Otherwise, if the
1985 : : * cancel request is successfully issued, it is appended to *cancel_requested.
1986 : : */
1987 : : static bool
1285 efujita@postgresql.o 1988 : 8 : pgfdw_abort_cleanup_begin(ConnCacheEntry *entry, bool toplevel,
1989 : : List **pending_entries, List **cancel_requested)
1990 : : {
1991 : : /*
1992 : : * Don't try to clean up the connection if we're already in error
1993 : : * recursion trouble.
1994 : : */
1995 [ - + ]: 8 : if (in_error_recursion_trouble())
1285 efujita@postgresql.o 1996 :UBC 0 : entry->changing_xact_state = true;
1997 : :
1998 : : /*
1999 : : * If connection is already unsalvageable, don't touch it further.
2000 : : */
1285 efujita@postgresql.o 2001 [ - + ]:CBC 8 : if (entry->changing_xact_state)
1285 efujita@postgresql.o 2002 :UBC 0 : return false;
2003 : :
2004 : : /*
2005 : : * Mark this connection as in the process of changing transaction state.
2006 : : */
1285 efujita@postgresql.o 2007 :CBC 8 : entry->changing_xact_state = true;
2008 : :
2009 : : /* Assume we might have lost track of prepared statements */
2010 : 8 : entry->have_error = true;
2011 : :
2012 : : /*
2013 : : * If a command has been submitted to the remote server by using an
2014 : : * asynchronous execution function, the command might not have yet
2015 : : * completed. Check to see if a command is still being processed by the
2016 : : * remote server, and if so, request cancellation of the command.
2017 : : */
2018 [ - + ]: 8 : if (PQtransactionStatus(entry->conn) == PQTRANS_ACTIVE)
2019 : : {
2020 : : TimestampTz endtime;
2021 : :
928 alvherre@alvh.no-ip. 2022 :UBC 0 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
2023 : : CONNECTION_CLEANUP_TIMEOUT);
2024 [ # # ]: 0 : if (!pgfdw_cancel_query_begin(entry->conn, endtime))
1285 efujita@postgresql.o 2025 : 0 : return false; /* Unable to cancel running query */
2026 : 0 : *cancel_requested = lappend(*cancel_requested, entry);
2027 : : }
2028 : : else
2029 : : {
2030 : : char sql[100];
2031 : :
1285 efujita@postgresql.o 2032 [ + + ]:CBC 8 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
2033 [ - + ]: 8 : if (!pgfdw_exec_cleanup_query_begin(entry->conn, sql))
1285 efujita@postgresql.o 2034 :UBC 0 : return false; /* Unable to abort remote transaction */
1285 efujita@postgresql.o 2035 :CBC 8 : *pending_entries = lappend(*pending_entries, entry);
2036 : : }
2037 : :
2038 : 8 : return true;
2039 : : }
2040 : :
2041 : : /*
2042 : : * Finish pre-commit cleanup of connections on each of which we've sent a
2043 : : * COMMIT command to the remote server.
2044 : : */
2045 : : static void
1691 2046 : 13 : pgfdw_finish_pre_commit_cleanup(List *pending_entries)
2047 : : {
2048 : : ConnCacheEntry *entry;
2049 : 13 : List *pending_deallocs = NIL;
2050 : : ListCell *lc;
2051 : :
2052 [ - + ]: 13 : Assert(pending_entries);
2053 : :
2054 : : /*
2055 : : * Get the result of the COMMIT command for each of the pending entries
2056 : : */
2057 [ + - + + : 29 : foreach(lc, pending_entries)
+ + ]
2058 : : {
2059 : : char sql[100];
2060 : :
2061 : 16 : entry = (ConnCacheEntry *) lfirst(lc);
2062 : :
2063 [ - + ]: 16 : Assert(entry->changing_xact_state);
2064 : :
2065 : : /*
2066 : : * We might already have received the result on the socket, so pass
2067 : : * consume_input=true to try to consume it first
2068 : : */
7 2069 [ - + - - ]: 16 : CONSTRUCT_COMMIT_COMMAND(sql, entry);
2070 : 16 : do_sql_command_end(entry->conn, sql, true);
2071 [ - + - - ]: 16 : if ((read_only_level > 0) && !(entry)->xact_read_only)
7 efujita@postgresql.o 2072 :UBC 0 : entry->xact_read_only = true;
1691 efujita@postgresql.o 2073 :CBC 16 : entry->changing_xact_state = false;
2074 : :
2075 : : /* Do a DEALLOCATE ALL in parallel if needed */
2076 [ + + + + ]: 16 : if (entry->have_prep_stmt && entry->have_error)
2077 : : {
2078 : : /* Ignore errors (see notes in pgfdw_xact_callback) */
2079 [ + - ]: 2 : if (PQsendQuery(entry->conn, "DEALLOCATE ALL"))
2080 : : {
2081 : 2 : pending_deallocs = lappend(pending_deallocs, entry);
2082 : 2 : continue;
2083 : : }
2084 : : }
2085 : 14 : entry->have_prep_stmt = false;
2086 : 14 : entry->have_error = false;
2087 : :
2088 : 14 : pgfdw_reset_xact_state(entry, true);
2089 : : }
2090 : :
2091 : : /* No further work if no pending entries */
2092 [ + + ]: 13 : if (!pending_deallocs)
2093 : 12 : return;
2094 : :
2095 : : /*
2096 : : * Get the result of the DEALLOCATE command for each of the pending
2097 : : * entries
2098 : : */
2099 [ + - + + : 3 : foreach(lc, pending_deallocs)
+ + ]
2100 : : {
2101 : : PGresult *res;
2102 : :
2103 : 2 : entry = (ConnCacheEntry *) lfirst(lc);
2104 : :
2105 : : /* Ignore errors (see notes in pgfdw_xact_callback) */
2106 [ + + ]: 4 : while ((res = PQgetResult(entry->conn)) != NULL)
2107 : : {
2108 : 2 : PQclear(res);
2109 : : /* Stop if the connection is lost (else we'll loop infinitely) */
2110 [ - + ]: 2 : if (PQstatus(entry->conn) == CONNECTION_BAD)
1691 efujita@postgresql.o 2111 :UBC 0 : break;
2112 : : }
1691 efujita@postgresql.o 2113 :CBC 2 : entry->have_prep_stmt = false;
2114 : 2 : entry->have_error = false;
2115 : :
2116 : 2 : pgfdw_reset_xact_state(entry, true);
2117 : : }
2118 : : }
2119 : :
2120 : : /*
2121 : : * Finish pre-subcommit cleanup of connections on each of which we've sent a
2122 : : * RELEASE command to the remote server.
2123 : : */
2124 : : static void
2125 : 1 : pgfdw_finish_pre_subcommit_cleanup(List *pending_entries, int curlevel)
2126 : : {
2127 : : ConnCacheEntry *entry;
2128 : : char sql[100];
2129 : : ListCell *lc;
2130 : :
2131 [ - + ]: 1 : Assert(pending_entries);
2132 : :
2133 : : /*
2134 : : * Get the result of the RELEASE command for each of the pending entries
2135 : : */
2136 : 1 : snprintf(sql, sizeof(sql), "RELEASE SAVEPOINT s%d", curlevel);
2137 [ + - + + : 3 : foreach(lc, pending_entries)
+ + ]
2138 : : {
2139 : 2 : entry = (ConnCacheEntry *) lfirst(lc);
2140 : :
2141 [ - + ]: 2 : Assert(entry->changing_xact_state);
2142 : :
2143 : : /*
2144 : : * We might already have received the result on the socket, so pass
2145 : : * consume_input=true to try to consume it first
2146 : : */
2147 : 2 : do_sql_command_end(entry->conn, sql, true);
2148 : 2 : entry->changing_xact_state = false;
2149 : :
2150 : 2 : pgfdw_reset_xact_state(entry, false);
2151 : : }
2152 : 1 : }
2153 : :
2154 : : /*
2155 : : * Finish abort cleanup of connections on each of which we've sent an abort
2156 : : * command or cancel request to the remote server.
2157 : : */
2158 : : static void
1285 2159 : 4 : pgfdw_finish_abort_cleanup(List *pending_entries, List *cancel_requested,
2160 : : bool toplevel)
2161 : : {
2162 : 4 : List *pending_deallocs = NIL;
2163 : : ListCell *lc;
2164 : :
2165 : : /*
2166 : : * For each of the pending cancel requests (if any), get and discard the
2167 : : * result of the query, and submit an abort command to the remote server.
2168 : : */
2169 [ - + ]: 4 : if (cancel_requested)
2170 : : {
1285 efujita@postgresql.o 2171 [ # # # # :UBC 0 : foreach(lc, cancel_requested)
# # ]
2172 : : {
2173 : 0 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
658 tgl@sss.pgh.pa.us 2174 : 0 : TimestampTz now = GetCurrentTimestamp();
2175 : : TimestampTz endtime;
2176 : : TimestampTz retrycanceltime;
2177 : : char sql[100];
2178 : :
1285 efujita@postgresql.o 2179 [ # # ]: 0 : Assert(entry->changing_xact_state);
2180 : :
2181 : : /*
2182 : : * Set end time. You might think we should do this before issuing
2183 : : * cancel request like in normal mode, but that is problematic,
2184 : : * because if, for example, it took longer than 30 seconds to
2185 : : * process the first few entries in the cancel_requested list, it
2186 : : * would cause a timeout error when processing each of the
2187 : : * remaining entries in the list, leading to slamming that entry's
2188 : : * connection shut.
2189 : : */
658 tgl@sss.pgh.pa.us 2190 : 0 : endtime = TimestampTzPlusMilliseconds(now,
2191 : : CONNECTION_CLEANUP_TIMEOUT);
2192 : 0 : retrycanceltime = TimestampTzPlusMilliseconds(now,
2193 : : RETRY_CANCEL_TIMEOUT);
2194 : :
2195 [ # # ]: 0 : if (!pgfdw_cancel_query_end(entry->conn, endtime,
2196 : : retrycanceltime, true))
2197 : : {
2198 : : /* Unable to cancel running query */
1285 efujita@postgresql.o 2199 : 0 : pgfdw_reset_xact_state(entry, toplevel);
2200 : 0 : continue;
2201 : : }
2202 : :
2203 : : /* Send an abort command in parallel if needed */
2204 [ # # ]: 0 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
2205 [ # # ]: 0 : if (!pgfdw_exec_cleanup_query_begin(entry->conn, sql))
2206 : : {
2207 : : /* Unable to abort remote (sub)transaction */
2208 : 0 : pgfdw_reset_xact_state(entry, toplevel);
2209 : : }
2210 : : else
2211 : 0 : pending_entries = lappend(pending_entries, entry);
2212 : : }
2213 : : }
2214 : :
2215 : : /* No further work if no pending entries */
1285 efujita@postgresql.o 2216 [ - + ]:CBC 4 : if (!pending_entries)
1285 efujita@postgresql.o 2217 :UBC 0 : return;
2218 : :
2219 : : /*
2220 : : * Get the result of the abort command for each of the pending entries
2221 : : */
1285 efujita@postgresql.o 2222 [ + - + + :CBC 12 : foreach(lc, pending_entries)
+ + ]
2223 : : {
2224 : 8 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
2225 : : TimestampTz endtime;
2226 : : char sql[100];
2227 : :
2228 [ - + ]: 8 : Assert(entry->changing_xact_state);
2229 : :
2230 : : /*
2231 : : * Set end time. We do this now, not before issuing the command like
2232 : : * in normal mode, for the same reason as for the cancel_requested
2233 : : * entries.
2234 : : */
2235 : 8 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
2236 : : CONNECTION_CLEANUP_TIMEOUT);
2237 : :
2238 [ + + ]: 8 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
2239 [ - + ]: 8 : if (!pgfdw_exec_cleanup_query_end(entry->conn, sql, endtime,
2240 : : true, false))
2241 : : {
2242 : : /* Unable to abort remote (sub)transaction */
1285 efujita@postgresql.o 2243 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
1285 efujita@postgresql.o 2244 :CBC 4 : continue;
2245 : : }
2246 : :
2247 [ + + ]: 8 : if (toplevel)
2248 : : {
2249 : : /* Do a DEALLOCATE ALL in parallel if needed */
2250 [ + - + - ]: 4 : if (entry->have_prep_stmt && entry->have_error)
2251 : : {
2252 [ - + ]: 4 : if (!pgfdw_exec_cleanup_query_begin(entry->conn,
2253 : : "DEALLOCATE ALL"))
2254 : : {
2255 : : /* Trouble clearing prepared statements */
1285 efujita@postgresql.o 2256 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
2257 : : }
2258 : : else
1285 efujita@postgresql.o 2259 :CBC 4 : pending_deallocs = lappend(pending_deallocs, entry);
2260 : 4 : continue;
2261 : : }
1285 efujita@postgresql.o 2262 :UBC 0 : entry->have_prep_stmt = false;
2263 : 0 : entry->have_error = false;
2264 : : }
2265 : :
2266 : : /* Reset the per-connection state if needed */
1285 efujita@postgresql.o 2267 [ - + ]:CBC 4 : if (entry->state.pendingAreq)
1285 efujita@postgresql.o 2268 :UBC 0 : memset(&entry->state, 0, sizeof(entry->state));
2269 : :
2270 : : /* We're done with this entry; unset the changing_xact_state flag */
1285 efujita@postgresql.o 2271 :CBC 4 : entry->changing_xact_state = false;
2272 : 4 : pgfdw_reset_xact_state(entry, toplevel);
2273 : : }
2274 : :
2275 : : /* No further work if no pending entries */
2276 [ + + ]: 4 : if (!pending_deallocs)
2277 : 2 : return;
2278 [ - + ]: 2 : Assert(toplevel);
2279 : :
2280 : : /*
2281 : : * Get the result of the DEALLOCATE command for each of the pending
2282 : : * entries
2283 : : */
2284 [ + - + + : 6 : foreach(lc, pending_deallocs)
+ + ]
2285 : : {
2286 : 4 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
2287 : : TimestampTz endtime;
2288 : :
2289 [ - + ]: 4 : Assert(entry->changing_xact_state);
2290 [ - + ]: 4 : Assert(entry->have_prep_stmt);
2291 [ - + ]: 4 : Assert(entry->have_error);
2292 : :
2293 : : /*
2294 : : * Set end time. We do this now, not before issuing the command like
2295 : : * in normal mode, for the same reason as for the cancel_requested
2296 : : * entries.
2297 : : */
2298 : 4 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
2299 : : CONNECTION_CLEANUP_TIMEOUT);
2300 : :
2301 [ - + ]: 4 : if (!pgfdw_exec_cleanup_query_end(entry->conn, "DEALLOCATE ALL",
2302 : : endtime, true, true))
2303 : : {
2304 : : /* Trouble clearing prepared statements */
1285 efujita@postgresql.o 2305 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
2306 : 0 : continue;
2307 : : }
1285 efujita@postgresql.o 2308 :CBC 4 : entry->have_prep_stmt = false;
2309 : 4 : entry->have_error = false;
2310 : :
2311 : : /* Reset the per-connection state if needed */
2312 [ - + ]: 4 : if (entry->state.pendingAreq)
1285 efujita@postgresql.o 2313 :UBC 0 : memset(&entry->state, 0, sizeof(entry->state));
2314 : :
2315 : : /* We're done with this entry; unset the changing_xact_state flag */
1285 efujita@postgresql.o 2316 :CBC 4 : entry->changing_xact_state = false;
2317 : 4 : pgfdw_reset_xact_state(entry, toplevel);
2318 : : }
2319 : : }
2320 : :
2321 : : /* Number of output arguments (columns) for various API versions */
2322 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_1 2
2323 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_2 6
2324 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS 6 /* maximum of above */
2325 : :
2326 : : /*
2327 : : * Internal function used by postgres_fdw_get_connections variants.
2328 : : *
2329 : : * For API version 1.1, this function takes no input parameter and
2330 : : * returns a set of records with the following values:
2331 : : *
2332 : : * - server_name - server name of active connection. In case the foreign server
2333 : : * is dropped but still the connection is active, then the server name will
2334 : : * be NULL in output.
2335 : : * - valid - true/false representing whether the connection is valid or not.
2336 : : * Note that connections can become invalid in pgfdw_inval_callback.
2337 : : *
2338 : : * For API version 1.2 and later, this function takes an input parameter
2339 : : * to check a connection status and returns the following
2340 : : * additional values along with the four values from version 1.1:
2341 : : *
2342 : : * - user_name - the local user name of the active connection. In case the
2343 : : * user mapping is dropped but the connection is still active, then the
2344 : : * user name will be NULL in the output.
2345 : : * - used_in_xact - true if the connection is used in the current transaction.
2346 : : * - closed - true if the connection is closed.
2347 : : * - remote_backend_pid - process ID of the remote backend, on the foreign
2348 : : * server, handling the connection.
2349 : : *
2350 : : * No records are returned when there are no cached connections at all.
2351 : : */
2352 : : static void
808 fujii@postgresql.org 2353 : 14 : postgres_fdw_get_connections_internal(FunctionCallInfo fcinfo,
2354 : : enum pgfdwVersion api_version)
2355 : : {
2093 2356 : 14 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
2357 : : HASH_SEQ_STATUS scan;
2358 : : ConnCacheEntry *entry;
2359 : :
1455 michael@paquier.xyz 2360 : 14 : InitMaterializedSRF(fcinfo, 0);
2361 : :
2362 : : /* If cache doesn't exist, we return no records */
2093 fujii@postgresql.org 2363 [ - + ]: 14 : if (!ConnectionHash)
808 fujii@postgresql.org 2364 :UBC 0 : return;
2365 : :
2366 : : /* Check we have the expected number of output arguments */
808 fujii@postgresql.org 2367 [ - + - ]:CBC 14 : switch (rsinfo->setDesc->natts)
2368 : : {
808 fujii@postgresql.org 2369 :UBC 0 : case POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_1:
2370 [ # # ]: 0 : if (api_version != PGFDW_V1_1)
2371 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
2372 : 0 : break;
808 fujii@postgresql.org 2373 :CBC 14 : case POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_2:
2374 [ - + ]: 14 : if (api_version != PGFDW_V1_2)
808 fujii@postgresql.org 2375 [ # # ]:UBC 0 : elog(ERROR, "incorrect number of output arguments");
808 fujii@postgresql.org 2376 :CBC 14 : break;
808 fujii@postgresql.org 2377 :UBC 0 : default:
2378 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
2379 : : }
2380 : :
2093 fujii@postgresql.org 2381 :CBC 14 : hash_seq_init(&scan, ConnectionHash);
2382 [ + + ]: 123 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
2383 : : {
2384 : : ForeignServer *server;
1549 peter@eisentraut.org 2385 : 109 : Datum values[POSTGRES_FDW_GET_CONNECTIONS_COLS] = {0};
2386 : 109 : bool nulls[POSTGRES_FDW_GET_CONNECTIONS_COLS] = {0};
754 fujii@postgresql.org 2387 : 109 : int i = 0;
2388 : :
2389 : : /* We only look for open remote connections */
2093 2390 [ + + ]: 109 : if (!entry->conn)
2391 : 95 : continue;
2392 : :
2393 : 14 : server = GetForeignServerExtended(entry->serverid, FSV_MISSING_OK);
2394 : :
2395 : : /*
2396 : : * The foreign server may have been dropped in current explicit
2397 : : * transaction. It is not possible to drop the server from another
2398 : : * session when the connection associated with it is in use in the
2399 : : * current transaction, if tried so, the drop query in another session
2400 : : * blocks until the current transaction finishes.
2401 : : *
2402 : : * Even though the server is dropped in the current transaction, the
2403 : : * cache can still have associated active connection entry, say we
2404 : : * call such connections dangling. Since we can not fetch the server
2405 : : * name from system catalogs for dangling connections, instead we show
2406 : : * NULL value for server name in output.
2407 : : *
2408 : : * We could have done better by storing the server name in the cache
2409 : : * entry instead of server oid so that it could be used in the output.
2410 : : * But the server name in each cache entry requires 64 bytes of
2411 : : * memory, which is huge, when there are many cached connections and
2412 : : * the use case i.e. dropping the foreign server within the explicit
2413 : : * current transaction seems rare. So, we chose to show NULL value for
2414 : : * server name in output.
2415 : : *
2416 : : * Such dangling connections get closed either in next use or at the
2417 : : * end of current explicit transaction in pgfdw_xact_callback.
2418 : : */
2419 [ + + ]: 14 : if (!server)
2420 : : {
2421 : : /*
2422 : : * If the server has been dropped in the current explicit
2423 : : * transaction, then this entry would have been invalidated in
2424 : : * pgfdw_inval_callback at the end of drop server command. Note
2425 : : * that this connection would not have been closed in
2426 : : * pgfdw_inval_callback because it is still being used in the
2427 : : * current explicit transaction. So, assert that here.
2428 : : */
2429 [ + - + - : 1 : Assert(entry->conn && entry->xact_depth > 0 && entry->invalidated);
- + ]
2430 : :
2431 : : /* Show null, if no server name was found */
754 2432 : 1 : nulls[i++] = true;
2433 : : }
2434 : : else
2435 : 13 : values[i++] = CStringGetTextDatum(server->servername);
2436 : :
2437 [ + - ]: 14 : if (api_version >= PGFDW_V1_2)
2438 : : {
2439 : : HeapTuple tp;
2440 : :
2441 : : /* Use the system cache to obtain the user mapping */
2442 : 14 : tp = SearchSysCache1(USERMAPPINGOID, ObjectIdGetDatum(entry->key));
2443 : :
2444 : : /*
2445 : : * Just like in the foreign server case, user mappings can also be
2446 : : * dropped in the current explicit transaction. Therefore, the
2447 : : * similar check as in the server case is required.
2448 : : */
2449 [ + + ]: 14 : if (!HeapTupleIsValid(tp))
2450 : : {
2451 : : /*
2452 : : * If we reach here, this entry must have been invalidated in
2453 : : * pgfdw_inval_callback, same as in the server case.
2454 : : */
2455 [ + - + - : 1 : Assert(entry->conn && entry->xact_depth > 0 &&
- + ]
2456 : : entry->invalidated);
2457 : :
2458 : 1 : nulls[i++] = true;
2459 : : }
2460 : : else
2461 : : {
2462 : : Oid userid;
2463 : :
2464 : 13 : userid = ((Form_pg_user_mapping) GETSTRUCT(tp))->umuser;
2465 [ + + ]: 13 : values[i++] = CStringGetTextDatum(MappingUserName(userid));
2466 : 13 : ReleaseSysCache(tp);
2467 : : }
2468 : : }
2469 : :
2470 : 14 : values[i++] = BoolGetDatum(!entry->invalidated);
2471 : :
808 2472 [ + - ]: 14 : if (api_version >= PGFDW_V1_2)
2473 : : {
2474 : 14 : bool check_conn = PG_GETARG_BOOL(0);
2475 : :
2476 : : /* Is this connection used in the current transaction? */
754 2477 : 14 : values[i++] = BoolGetDatum(entry->xact_depth > 0);
2478 : :
2479 : : /*
2480 : : * If a connection status check is requested and supported, return
2481 : : * whether the connection is closed. Otherwise, return NULL.
2482 : : */
808 2483 [ + + + - ]: 14 : if (check_conn && pgfdw_conn_checkable())
754 2484 : 3 : values[i++] = BoolGetDatum(pgfdw_conn_check(entry->conn) != 0);
2485 : : else
2486 : 11 : nulls[i++] = true;
2487 : :
2488 : : /* Return process ID of remote backend */
588 2489 : 14 : values[i++] = Int32GetDatum(PQbackendPID(entry->conn));
2490 : : }
2491 : :
1679 michael@paquier.xyz 2492 : 14 : tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
2493 : : }
2494 : : }
2495 : :
2496 : : /*
2497 : : * Values in connection strings must be enclosed in single quotes. Single
2498 : : * quotes and backslashes must be escaped with backslash. NB: these rules are
2499 : : * different from the rules for escaping a SQL literal.
2500 : : */
2501 : : static void
220 jdavis@postgresql.or 2502 : 35 : appendEscapedValue(StringInfo str, const char *val)
2503 : : {
2504 : 35 : appendStringInfoChar(str, '\'');
2505 [ + + ]: 343 : for (int i = 0; val[i] != '\0'; i++)
2506 : : {
2507 [ + - - + ]: 308 : if (val[i] == '\\' || val[i] == '\'')
220 jdavis@postgresql.or 2508 :UBC 0 : appendStringInfoChar(str, '\\');
220 jdavis@postgresql.or 2509 :CBC 308 : appendStringInfoChar(str, val[i]);
2510 : : }
2511 : 35 : appendStringInfoChar(str, '\'');
2512 : 35 : }
2513 : :
2514 : : Datum
2515 : 8 : postgres_fdw_connection(PG_FUNCTION_ARGS)
2516 : : {
2517 : 8 : Oid userid = PG_GETARG_OID(0);
2518 : 8 : Oid serverid = PG_GETARG_OID(1);
2519 : 8 : ForeignServer *server = GetForeignServer(serverid);
2520 : 8 : UserMapping *user = GetUserMapping(userid, serverid);
2521 : : StringInfoData str;
2522 : : const char **keywords;
2523 : : const char **values;
2524 : : char *appname;
2525 : 8 : char *sep = "";
2526 : :
2527 : : /*
2528 : : * SCRAM pass-through cannot work for subscriptions because the connection
2529 : : * happens in a worker process.
2530 : : */
70 2531 [ + + ]: 8 : if (UseScramPassthrough(server, user))
2532 [ + - ]: 1 : ereport(ERROR,
2533 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2534 : : errmsg("SCRAM pass-through authentication is not supported for subscription connections"),
2535 : : errdetail("The foreign server or user mapping for user \"%s\" has \"use_scram_passthrough\" enabled.",
2536 : : GetUserNameFromId(userid, false)),
2537 : : errhint("Store a password in the user mapping instead.")));
2538 : :
220 2539 : 7 : construct_connection_params(server, user, &keywords, &values, &appname);
2540 : :
2541 : 7 : initStringInfo(&str);
2542 [ + + ]: 42 : for (int i = 0; keywords[i] != NULL; i++)
2543 : : {
2544 [ - + ]: 35 : if (values[i] == NULL)
220 jdavis@postgresql.or 2545 :UBC 0 : continue;
220 jdavis@postgresql.or 2546 :CBC 35 : appendStringInfo(&str, "%s%s = ", sep, keywords[i]);
2547 : 35 : appendEscapedValue(&str, values[i]);
2548 : 35 : sep = " ";
2549 : : }
2550 : :
2551 [ - + ]: 7 : if (appname != NULL)
220 jdavis@postgresql.or 2552 :UBC 0 : pfree(appname);
220 jdavis@postgresql.or 2553 :CBC 7 : pfree(keywords);
2554 : 7 : pfree(values);
2555 : 7 : PG_RETURN_TEXT_P(cstring_to_text(str.data));
2556 : : }
2557 : :
2558 : : /*
2559 : : * List active foreign server connections.
2560 : : *
2561 : : * The SQL API of this function has changed multiple times, and will likely
2562 : : * do so again in future. To support the case where a newer version of this
2563 : : * loadable module is being used with an old SQL declaration of the function,
2564 : : * we continue to support the older API versions.
2565 : : */
2566 : : Datum
808 fujii@postgresql.org 2567 : 14 : postgres_fdw_get_connections_1_2(PG_FUNCTION_ARGS)
2568 : : {
2569 : 14 : postgres_fdw_get_connections_internal(fcinfo, PGFDW_V1_2);
2570 : :
2571 : 14 : PG_RETURN_VOID();
2572 : : }
2573 : :
2574 : : Datum
808 fujii@postgresql.org 2575 :UBC 0 : postgres_fdw_get_connections(PG_FUNCTION_ARGS)
2576 : : {
2577 : 0 : postgres_fdw_get_connections_internal(fcinfo, PGFDW_V1_1);
2578 : :
2093 2579 : 0 : PG_RETURN_VOID();
2580 : : }
2581 : :
2582 : : /*
2583 : : * Disconnect the specified cached connections.
2584 : : *
2585 : : * This function discards the open connections that are established by
2586 : : * postgres_fdw from the local session to the foreign server with
2587 : : * the given name. Note that there can be multiple connections to
2588 : : * the given server using different user mappings. If the connections
2589 : : * are used in the current local transaction, they are not disconnected
2590 : : * and warning messages are reported. This function returns true
2591 : : * if it disconnects at least one connection, otherwise false. If no
2592 : : * foreign server with the given name is found, an error is reported.
2593 : : */
2594 : : Datum
2085 fujii@postgresql.org 2595 :CBC 4 : postgres_fdw_disconnect(PG_FUNCTION_ARGS)
2596 : : {
2597 : : ForeignServer *server;
2598 : : char *servername;
2599 : :
2600 : 4 : servername = text_to_cstring(PG_GETARG_TEXT_PP(0));
2601 : 4 : server = GetForeignServerByName(servername, false);
2602 : :
2603 : 3 : PG_RETURN_BOOL(disconnect_cached_connections(server->serverid));
2604 : : }
2605 : :
2606 : : /*
2607 : : * Disconnect all the cached connections.
2608 : : *
2609 : : * This function discards all the open connections that are established by
2610 : : * postgres_fdw from the local session to the foreign servers.
2611 : : * If the connections are used in the current local transaction, they are
2612 : : * not disconnected and warning messages are reported. This function
2613 : : * returns true if it disconnects at least one connection, otherwise false.
2614 : : */
2615 : : Datum
2616 : 6 : postgres_fdw_disconnect_all(PG_FUNCTION_ARGS)
2617 : : {
2618 : 6 : PG_RETURN_BOOL(disconnect_cached_connections(InvalidOid));
2619 : : }
2620 : :
2621 : : /*
2622 : : * Workhorse to disconnect cached connections.
2623 : : *
2624 : : * This function scans all the connection cache entries and disconnects
2625 : : * the open connections whose foreign server OID matches with
2626 : : * the specified one. If InvalidOid is specified, it disconnects all
2627 : : * the cached connections.
2628 : : *
2629 : : * This function emits a warning for each connection that's used in
2630 : : * the current transaction and doesn't close it. It returns true if
2631 : : * it disconnects at least one connection, otherwise false.
2632 : : *
2633 : : * Note that this function disconnects even the connections that are
2634 : : * established by other users in the same local session using different
2635 : : * user mappings. This leads even non-superuser to be able to close
2636 : : * the connections established by superusers in the same local session.
2637 : : *
2638 : : * XXX As of now we don't see any security risk doing this. But we should
2639 : : * set some restrictions on that, for example, prevent non-superuser
2640 : : * from closing the connections established by superusers even
2641 : : * in the same session?
2642 : : */
2643 : : static bool
2644 : 9 : disconnect_cached_connections(Oid serverid)
2645 : : {
2646 : : HASH_SEQ_STATUS scan;
2647 : : ConnCacheEntry *entry;
2648 : 9 : bool all = !OidIsValid(serverid);
2649 : 9 : bool result = false;
2650 : :
2651 : : /*
2652 : : * Connection cache hashtable has not been initialized yet in this
2653 : : * session, so return false.
2654 : : */
2655 [ - + ]: 9 : if (!ConnectionHash)
2085 fujii@postgresql.org 2656 :UBC 0 : return false;
2657 : :
2085 fujii@postgresql.org 2658 :CBC 9 : hash_seq_init(&scan, ConnectionHash);
2659 [ + + ]: 77 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
2660 : : {
2661 : : /* Ignore cache entry if no open connection right now. */
2662 [ + + ]: 68 : if (!entry->conn)
2663 : 55 : continue;
2664 : :
2665 [ + + + + ]: 13 : if (all || entry->serverid == serverid)
2666 : : {
2667 : : /*
2668 : : * Emit a warning because the connection to close is used in the
2669 : : * current transaction and cannot be disconnected right now.
2670 : : */
2671 [ + + ]: 10 : if (entry->xact_depth > 0)
2672 : : {
2673 : : ForeignServer *server;
2674 : :
2675 : 3 : server = GetForeignServerExtended(entry->serverid,
2676 : : FSV_MISSING_OK);
2677 : :
2678 [ - + ]: 3 : if (!server)
2679 : : {
2680 : : /*
2681 : : * If the foreign server was dropped while its connection
2682 : : * was used in the current transaction, the connection
2683 : : * must have been marked as invalid by
2684 : : * pgfdw_inval_callback at the end of DROP SERVER command.
2685 : : */
2085 fujii@postgresql.org 2686 [ # # ]:UBC 0 : Assert(entry->invalidated);
2687 : :
2688 [ # # ]: 0 : ereport(WARNING,
2689 : : (errmsg("cannot close dropped server connection because it is still in use")));
2690 : : }
2691 : : else
2085 fujii@postgresql.org 2692 [ + - ]:CBC 3 : ereport(WARNING,
2693 : : (errmsg("cannot close connection for server \"%s\" because it is still in use",
2694 : : server->servername)));
2695 : : }
2696 : : else
2697 : : {
2698 [ - + ]: 7 : elog(DEBUG3, "discarding connection %p", entry->conn);
2699 : 7 : disconnect_pg_server(entry);
2700 : 7 : result = true;
2701 : : }
2702 : : }
2703 : : }
2704 : :
2705 : 9 : return result;
2706 : : }
2707 : :
2708 : : /*
2709 : : * Check if the remote server closed the connection.
2710 : : *
2711 : : * Returns 1 if the connection is closed, -1 if an error occurred,
2712 : : * and 0 if it's not closed or if the connection check is unavailable
2713 : : * on this platform.
2714 : : */
2715 : : static int
808 2716 : 3 : pgfdw_conn_check(PGconn *conn)
2717 : : {
2718 : 3 : int sock = PQsocket(conn);
2719 : :
2720 [ + - - + ]: 3 : if (PQstatus(conn) != CONNECTION_OK || sock == -1)
808 fujii@postgresql.org 2721 :UBC 0 : return -1;
2722 : :
2723 : : #if (defined(HAVE_POLL) && defined(POLLRDHUP))
2724 : : {
2725 : : struct pollfd input_fd;
2726 : : int result;
2727 : :
808 fujii@postgresql.org 2728 :CBC 3 : input_fd.fd = sock;
2729 : 3 : input_fd.events = POLLRDHUP;
2730 : 3 : input_fd.revents = 0;
2731 : :
2732 : : do
2733 : 3 : result = poll(&input_fd, 1, 0);
2734 [ - + - - ]: 3 : while (result < 0 && errno == EINTR);
2735 : :
2736 [ - + ]: 3 : if (result < 0)
808 fujii@postgresql.org 2737 :UBC 0 : return -1;
2738 : :
807 fujii@postgresql.org 2739 :CBC 3 : return (input_fd.revents &
2740 : 3 : (POLLRDHUP | POLLHUP | POLLERR | POLLNVAL)) ? 1 : 0;
2741 : : }
2742 : : #else
2743 : : return 0;
2744 : : #endif
2745 : : }
2746 : :
2747 : : /*
2748 : : * Check if connection status checking is available on this platform.
2749 : : *
2750 : : * Returns true if available, false otherwise.
2751 : : */
2752 : : static bool
808 2753 : 3 : pgfdw_conn_checkable(void)
2754 : : {
2755 : : #if (defined(HAVE_POLL) && defined(POLLRDHUP))
2756 : 3 : return true;
2757 : : #else
2758 : : return false;
2759 : : #endif
2760 : : }
2761 : :
2762 : : /*
2763 : : * Ensure that require_auth and SCRAM keys are correctly set on values. SCRAM
2764 : : * keys used to pass-through are coming from the initial connection from the
2765 : : * client with the server.
2766 : : *
2767 : : * All required SCRAM options are set by postgres_fdw, so we just need to
2768 : : * ensure that these options are not overwritten by the user.
2769 : : */
2770 : : static bool
567 peter@eisentraut.org 2771 : 9 : pgfdw_has_required_scram_options(const char **keywords, const char **values)
2772 : : {
2773 : 9 : bool has_scram_server_key = false;
2774 : 9 : bool has_scram_client_key = false;
2775 : 9 : bool has_require_auth = false;
2776 : 9 : bool has_scram_keys = false;
2777 : :
2778 : : /*
2779 : : * Continue iterating even if we found the keys that we need to validate
2780 : : * to make sure that there is no other declaration of these keys that can
2781 : : * overwrite the first.
2782 : : */
2783 [ + + ]: 87 : for (int i = 0; keywords[i] != NULL; i++)
2784 : : {
2785 [ + + ]: 78 : if (strcmp(keywords[i], "scram_client_key") == 0)
2786 : : {
2787 [ + - + - ]: 8 : if (values[i] != NULL && values[i][0] != '\0')
2788 : 8 : has_scram_client_key = true;
2789 : : else
567 peter@eisentraut.org 2790 :UBC 0 : has_scram_client_key = false;
2791 : : }
2792 : :
567 peter@eisentraut.org 2793 [ + + ]:CBC 78 : if (strcmp(keywords[i], "scram_server_key") == 0)
2794 : : {
2795 [ + - + - ]: 8 : if (values[i] != NULL && values[i][0] != '\0')
2796 : 8 : has_scram_server_key = true;
2797 : : else
567 peter@eisentraut.org 2798 :UBC 0 : has_scram_server_key = false;
2799 : : }
2800 : :
567 peter@eisentraut.org 2801 [ + + ]:CBC 78 : if (strcmp(keywords[i], "require_auth") == 0)
2802 : : {
2803 [ + - + - ]: 8 : if (values[i] != NULL && strcmp(values[i], "scram-sha-256") == 0)
2804 : 8 : has_require_auth = true;
2805 : : else
567 peter@eisentraut.org 2806 :UBC 0 : has_require_auth = false;
2807 : : }
2808 : : }
2809 : :
430 peter@eisentraut.org 2810 [ + + + - :CBC 9 : has_scram_keys = has_scram_client_key && has_scram_server_key && MyProcPort != NULL && MyProcPort->has_scram_keys;
+ - + - ]
2811 : :
567 2812 [ + + + - ]: 9 : return (has_scram_keys && has_require_auth);
2813 : : }
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