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 : : /* Macro for constructing abort command to be sent */
116 : : #define CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel) \
117 : : do { \
118 : : if (toplevel) \
119 : : snprintf((sql), sizeof(sql), \
120 : : "ABORT TRANSACTION"); \
121 : : else \
122 : : snprintf((sql), sizeof(sql), \
123 : : "ROLLBACK TO SAVEPOINT s%d; RELEASE SAVEPOINT s%d", \
124 : : (entry)->xact_depth, (entry)->xact_depth); \
125 : : } while(0)
126 : :
127 : : /*
128 : : * Extension version number, for supporting older extension versions' objects
129 : : */
130 : : enum pgfdwVersion
131 : : {
132 : : PGFDW_V1_1 = 0,
133 : : PGFDW_V1_2,
134 : : };
135 : :
136 : : /*
137 : : * SQL functions
138 : : */
1933 fujii@postgresql.org 139 :CBC 5 : PG_FUNCTION_INFO_V1(postgres_fdw_get_connections);
648 140 : 6 : PG_FUNCTION_INFO_V1(postgres_fdw_get_connections_1_2);
1925 141 : 6 : PG_FUNCTION_INFO_V1(postgres_fdw_disconnect);
142 : 6 : PG_FUNCTION_INFO_V1(postgres_fdw_disconnect_all);
60 jdavis@postgresql.or 143 :GNC 13 : PG_FUNCTION_INFO_V1(postgres_fdw_connection);
144 : :
145 : : /* prototypes of private functions */
146 : : static void make_new_connection(ConnCacheEntry *entry, UserMapping *user);
147 : : static PGconn *connect_pg_server(ForeignServer *server, UserMapping *user);
148 : : static void disconnect_pg_server(ConnCacheEntry *entry);
149 : : static void check_conn_params(const char **keywords, const char **values, UserMapping *user);
150 : : static void configure_remote_session(PGconn *conn);
151 : : static void do_sql_command_begin(PGconn *conn, const char *sql);
152 : : static void do_sql_command_end(PGconn *conn, const char *sql,
153 : : bool consume_input);
154 : : static void begin_remote_xact(ConnCacheEntry *entry);
155 : : static void pgfdw_report_internal(int elevel, PGresult *res, PGconn *conn,
156 : : const char *sql);
157 : : static void pgfdw_xact_callback(XactEvent event, void *arg);
158 : : static void pgfdw_subxact_callback(SubXactEvent event,
159 : : SubTransactionId mySubid,
160 : : SubTransactionId parentSubid,
161 : : void *arg);
162 : : static void pgfdw_inval_callback(Datum arg, SysCacheIdentifier cacheid,
163 : : uint32 hashvalue);
164 : : static void pgfdw_reject_incomplete_xact_state_change(ConnCacheEntry *entry);
165 : : static void pgfdw_reset_xact_state(ConnCacheEntry *entry, bool toplevel);
166 : : static bool pgfdw_cancel_query(PGconn *conn);
167 : : static bool pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime);
168 : : static bool pgfdw_cancel_query_end(PGconn *conn, TimestampTz endtime,
169 : : TimestampTz retrycanceltime,
170 : : bool consume_input);
171 : : static bool pgfdw_exec_cleanup_query(PGconn *conn, const char *query,
172 : : bool ignore_errors);
173 : : static bool pgfdw_exec_cleanup_query_begin(PGconn *conn, const char *query);
174 : : static bool pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query,
175 : : TimestampTz endtime,
176 : : bool consume_input,
177 : : bool ignore_errors);
178 : : static bool pgfdw_get_cleanup_result(PGconn *conn, TimestampTz endtime,
179 : : TimestampTz retrycanceltime,
180 : : PGresult **result, bool *timed_out);
181 : : static void pgfdw_abort_cleanup(ConnCacheEntry *entry, bool toplevel);
182 : : static bool pgfdw_abort_cleanup_begin(ConnCacheEntry *entry, bool toplevel,
183 : : List **pending_entries,
184 : : List **cancel_requested);
185 : : static void pgfdw_finish_pre_commit_cleanup(List *pending_entries);
186 : : static void pgfdw_finish_pre_subcommit_cleanup(List *pending_entries,
187 : : int curlevel);
188 : : static void pgfdw_finish_abort_cleanup(List *pending_entries,
189 : : List *cancel_requested,
190 : : bool toplevel);
191 : : static void pgfdw_security_check(const char **keywords, const char **values,
192 : : UserMapping *user, PGconn *conn);
193 : : static bool UserMappingPasswordRequired(UserMapping *user);
194 : : static bool UseScramPassthrough(ForeignServer *server, UserMapping *user);
195 : : static bool disconnect_cached_connections(Oid serverid);
196 : : static void postgres_fdw_get_connections_internal(FunctionCallInfo fcinfo,
197 : : enum pgfdwVersion api_version);
198 : : static int pgfdw_conn_check(PGconn *conn);
199 : : static bool pgfdw_conn_checkable(void);
200 : : static bool pgfdw_has_required_scram_options(const char **keywords, const char **values);
201 : :
202 : : /*
203 : : * Get a PGconn which can be used to execute queries on the remote PostgreSQL
204 : : * server with the user's authorization. A new connection is established
205 : : * if we don't already have a suitable one, and a transaction is opened at
206 : : * the right subtransaction nesting depth if we didn't do that already.
207 : : *
208 : : * will_prep_stmt must be true if caller intends to create any prepared
209 : : * statements. Since those don't go away automatically at transaction end
210 : : * (not even on error), we need this flag to cue manual cleanup.
211 : : *
212 : : * If state is not NULL, *state receives the per-connection state associated
213 : : * with the PGconn.
214 : : */
215 : : PGconn *
1861 efujita@postgresql.o 216 :CBC 2289 : GetConnection(UserMapping *user, bool will_prep_stmt, PgFdwConnState **state)
217 : : {
218 : : bool found;
2027 fujii@postgresql.org 219 : 2289 : bool retry = false;
220 : : ConnCacheEntry *entry;
221 : : ConnCacheKey key;
222 : 2289 : MemoryContext ccxt = CurrentMemoryContext;
223 : :
224 : : /* First time through, initialize connection cache hashtable */
4821 tgl@sss.pgh.pa.us 225 [ + + ]: 2289 : if (ConnectionHash == NULL)
226 : : {
227 : : HASHCTL ctl;
228 : :
848 noah@leadboat.com 229 [ + - ]: 16 : if (pgfdw_we_get_result == 0)
230 : 16 : pgfdw_we_get_result =
231 : 16 : WaitEventExtensionNew("PostgresFdwGetResult");
232 : :
4821 tgl@sss.pgh.pa.us 233 : 16 : ctl.keysize = sizeof(ConnCacheKey);
234 : 16 : ctl.entrysize = sizeof(ConnCacheEntry);
235 : 16 : ConnectionHash = hash_create("postgres_fdw connections", 8,
236 : : &ctl,
237 : : HASH_ELEM | HASH_BLOBS);
238 : :
239 : : /*
240 : : * Register some callback functions that manage connection cleanup.
241 : : * This should be done just once in each backend.
242 : : */
243 : 16 : RegisterXactCallback(pgfdw_xact_callback, NULL);
244 : 16 : RegisterSubXactCallback(pgfdw_subxact_callback, NULL);
3210 245 : 16 : CacheRegisterSyscacheCallback(FOREIGNSERVEROID,
246 : : pgfdw_inval_callback, (Datum) 0);
247 : 16 : CacheRegisterSyscacheCallback(USERMAPPINGOID,
248 : : pgfdw_inval_callback, (Datum) 0);
249 : : }
250 : :
251 : : /* Set flag that we did GetConnection during the current transaction */
4821 252 : 2289 : xact_got_connection = true;
253 : :
254 : : /* Create hash key for the entry. Assume no pad bytes in key struct */
3750 rhaas@postgresql.org 255 : 2289 : key = user->umid;
256 : :
257 : : /*
258 : : * Find or create cached entry for requested connection.
259 : : */
4821 tgl@sss.pgh.pa.us 260 : 2289 : entry = hash_search(ConnectionHash, &key, HASH_ENTER, &found);
261 [ + + ]: 2289 : if (!found)
262 : : {
263 : : /*
264 : : * We need only clear "conn" here; remaining fields will be filled
265 : : * later when "conn" is set.
266 : : */
267 : 27 : entry->conn = NULL;
268 : : }
269 : :
270 : : /* Reject further use of connections which failed abort cleanup. */
3254 rhaas@postgresql.org 271 : 2289 : pgfdw_reject_incomplete_xact_state_change(entry);
272 : :
273 : : /*
274 : : * If the connection needs to be remade due to invalidation, disconnect as
275 : : * soon as we're out of all transactions.
276 : : */
2027 fujii@postgresql.org 277 [ + + - + : 2289 : if (entry->conn != NULL && entry->invalidated && entry->xact_depth == 0)
- - ]
278 : : {
2027 fujii@postgresql.org 279 [ # # ]:UBC 0 : elog(DEBUG3, "closing connection %p for option changes to take effect",
280 : : entry->conn);
3210 tgl@sss.pgh.pa.us 281 : 0 : disconnect_pg_server(entry);
282 : : }
283 : :
284 : : /*
285 : : * If cache entry doesn't have a connection, we have to establish a new
286 : : * connection. (If connect_pg_server throws an error, the cache entry
287 : : * will remain in a valid empty state, ie conn == NULL.)
288 : : */
4821 tgl@sss.pgh.pa.us 289 [ + + ]:CBC 2289 : if (entry->conn == NULL)
2027 fujii@postgresql.org 290 : 88 : make_new_connection(entry, user);
291 : :
292 : : /*
293 : : * We check the health of the cached connection here when using it. In
294 : : * cases where we're out of all transactions, if a broken connection is
295 : : * detected, we try to reestablish a new connection later.
296 : : */
2037 297 [ + + ]: 2279 : PG_TRY();
298 : : {
299 : : /* Process a pending asynchronous request if any. */
1861 efujita@postgresql.o 300 [ - + ]: 2279 : if (entry->state.pendingAreq)
1861 efujita@postgresql.o 301 :UBC 0 : process_pending_request(entry->state.pendingAreq);
302 : : /* Start a new transaction or subtransaction if needed. */
2037 fujii@postgresql.org 303 :CBC 2279 : begin_remote_xact(entry);
304 : : }
305 : 2 : PG_CATCH();
306 : : {
2027 307 : 2 : MemoryContext ecxt = MemoryContextSwitchTo(ccxt);
308 : 2 : ErrorData *errdata = CopyErrorData();
309 : :
310 : : /*
311 : : * Determine whether to try to reestablish the connection.
312 : : *
313 : : * After a broken connection is detected in libpq, any error other
314 : : * than connection failure (e.g., out-of-memory) can be thrown
315 : : * somewhere between return from libpq and the expected ereport() call
316 : : * in pgfdw_report_error(). In this case, since PQstatus() indicates
317 : : * CONNECTION_BAD, checking only PQstatus() causes the false detection
318 : : * of connection failure. To avoid this, we also verify that the
319 : : * error's sqlstate is ERRCODE_CONNECTION_FAILURE. Note that also
320 : : * checking only the sqlstate can cause another false detection
321 : : * because pgfdw_report_error() may report ERRCODE_CONNECTION_FAILURE
322 : : * for any libpq-originated error condition.
323 : : */
324 [ + - ]: 2 : if (errdata->sqlerrcode != ERRCODE_CONNECTION_FAILURE ||
325 [ + - ]: 2 : PQstatus(entry->conn) != CONNECTION_BAD ||
326 [ + + ]: 2 : entry->xact_depth > 0)
327 : : {
328 : 1 : MemoryContextSwitchTo(ecxt);
2037 329 : 1 : PG_RE_THROW();
330 : : }
331 : :
332 : : /* Clean up the error state */
2027 333 : 1 : FlushErrorState();
334 : 1 : FreeErrorData(errdata);
335 : 1 : errdata = NULL;
336 : :
337 : 1 : retry = true;
338 : : }
2037 339 [ - + ]: 2278 : PG_END_TRY();
340 : :
341 : : /*
342 : : * If a broken connection is detected, disconnect it, reestablish a new
343 : : * connection and retry a new remote transaction. If connection failure is
344 : : * reported again, we give up getting a connection.
345 : : */
2027 346 [ + + ]: 2278 : if (retry)
347 : : {
348 [ - + ]: 1 : Assert(entry->xact_depth == 0);
349 : :
2037 350 [ - + ]: 1 : ereport(DEBUG3,
351 : : (errmsg_internal("could not start remote transaction on connection %p",
352 : : entry->conn)),
353 : : errdetail_internal("%s", pchomp(PQerrorMessage(entry->conn))));
354 : :
2027 355 [ - + ]: 1 : elog(DEBUG3, "closing connection %p to reestablish a new one",
356 : : entry->conn);
357 : 1 : disconnect_pg_server(entry);
358 : :
1145 efujita@postgresql.o 359 : 1 : make_new_connection(entry, user);
360 : :
2027 fujii@postgresql.org 361 : 1 : begin_remote_xact(entry);
362 : : }
363 : :
364 : : /* Remember if caller will prepare statements */
4804 tgl@sss.pgh.pa.us 365 : 2278 : entry->have_prep_stmt |= will_prep_stmt;
366 : :
367 : : /* If caller needs access to the per-connection state, return it. */
1861 efujita@postgresql.o 368 [ + + ]: 2278 : if (state)
369 : 777 : *state = &entry->state;
370 : :
4821 tgl@sss.pgh.pa.us 371 : 2278 : return entry->conn;
372 : : }
373 : :
374 : : /*
375 : : * Reset all transient state fields in the cached connection entry and
376 : : * establish new connection to the remote server.
377 : : */
378 : : static void
2027 fujii@postgresql.org 379 : 89 : make_new_connection(ConnCacheEntry *entry, UserMapping *user)
380 : : {
381 : 89 : ForeignServer *server = GetForeignServer(user->serverid);
382 : : ListCell *lc;
383 : :
384 [ - + ]: 89 : Assert(entry->conn == NULL);
385 : :
386 : : /* Reset all transient state fields, to be sure all are clean */
387 : 89 : entry->xact_depth = 0;
30 efujita@postgresql.o 388 :GNC 89 : entry->xact_read_only = false;
2027 fujii@postgresql.org 389 :CBC 89 : entry->have_prep_stmt = false;
390 : 89 : entry->have_error = false;
391 : 89 : entry->changing_xact_state = false;
392 : 89 : entry->invalidated = false;
1936 393 : 89 : entry->serverid = server->serverid;
2027 394 : 89 : entry->server_hashvalue =
395 : 89 : GetSysCacheHashValue1(FOREIGNSERVEROID,
396 : : ObjectIdGetDatum(server->serverid));
397 : 89 : entry->mapping_hashvalue =
398 : 89 : GetSysCacheHashValue1(USERMAPPINGOID,
399 : : ObjectIdGetDatum(user->umid));
1861 efujita@postgresql.o 400 : 89 : memset(&entry->state, 0, sizeof(entry->state));
401 : :
402 : : /*
403 : : * Determine whether to keep the connection that we're about to make here
404 : : * open even after the transaction using it ends, so that the subsequent
405 : : * transactions can re-use it.
406 : : *
407 : : * By default, all the connections to any foreign servers are kept open.
408 : : *
409 : : * Also determine whether to commit/abort (sub)transactions opened on the
410 : : * remote server in parallel at (sub)transaction end, which is disabled by
411 : : * default.
412 : : *
413 : : * Note: it's enough to determine these only when making a new connection
414 : : * because if these settings for it are changed, it will be closed and
415 : : * re-made later.
416 : : */
1859 fujii@postgresql.org 417 : 89 : entry->keep_connections = true;
1531 efujita@postgresql.o 418 : 89 : entry->parallel_commit = false;
1125 419 : 89 : entry->parallel_abort = false;
1859 fujii@postgresql.org 420 [ + - + + : 409 : foreach(lc, server->options)
+ + ]
421 : : {
422 : 320 : DefElem *def = (DefElem *) lfirst(lc);
423 : :
424 [ + + ]: 320 : if (strcmp(def->defname, "keep_connections") == 0)
425 : 14 : entry->keep_connections = defGetBoolean(def);
1531 efujita@postgresql.o 426 [ + + ]: 306 : else if (strcmp(def->defname, "parallel_commit") == 0)
427 : 2 : entry->parallel_commit = defGetBoolean(def);
1125 428 [ + + ]: 304 : else if (strcmp(def->defname, "parallel_abort") == 0)
429 : 2 : entry->parallel_abort = defGetBoolean(def);
430 : : }
431 : :
432 : : /* Now try to make the connection */
2027 fujii@postgresql.org 433 : 89 : entry->conn = connect_pg_server(server, user);
434 : :
435 [ - + ]: 79 : elog(DEBUG3, "new postgres_fdw connection %p for server \"%s\" (user mapping oid %u, userid %u)",
436 : : entry->conn, server->servername, user->umid, user->userid);
437 : 79 : }
438 : :
439 : : /*
440 : : * Check that non-superuser has used password or delegated credentials
441 : : * to establish connection; otherwise, he's piggybacking on the
442 : : * postgres server's user identity. See also dblink_security_check()
443 : : * in contrib/dblink and check_conn_params.
444 : : */
445 : : static void
1118 sfrost@snowman.net 446 : 82 : pgfdw_security_check(const char **keywords, const char **values, UserMapping *user, PGconn *conn)
447 : : {
448 : : /* Superusers bypass the check */
449 [ + + ]: 82 : if (superuser_arg(user->userid))
450 : 71 : return;
451 : :
452 : : #ifdef ENABLE_GSS
453 : : /* Connected via GSSAPI with delegated credentials- all good. */
1081 bruce@momjian.us 454 [ + + + - ]: 11 : if (PQconnectionUsedGSSAPI(conn) && be_gssapi_get_delegation(MyProcPort))
1118 sfrost@snowman.net 455 : 2 : return;
456 : : #endif
457 : :
458 : : /* Ok if superuser set PW required false. */
459 [ + + ]: 9 : if (!UserMappingPasswordRequired(user))
460 : 2 : return;
461 : :
462 : : /* Connected via PW, with PW required true, and provided non-empty PW. */
463 [ + + ]: 7 : if (PQconnectionUsedPassword(conn))
464 : : {
465 : : /* ok if params contain a non-empty password */
466 [ + + ]: 47 : for (int i = 0; keywords[i] != NULL; i++)
467 : : {
468 [ - + - - ]: 42 : if (strcmp(keywords[i], "password") == 0 && values[i][0] != '\0')
1118 sfrost@snowman.net 469 :UBC 0 : return;
470 : : }
471 : : }
472 : :
473 : : /*
474 : : * Ok if SCRAM pass-through is being used and all required SCRAM options
475 : : * are set correctly. If pgfdw_has_required_scram_options returns true we
476 : : * assume that UseScramPassthrough is also true since SCRAM options are
477 : : * only set when UseScramPassthrough is enabled.
478 : : */
270 peter@eisentraut.org 479 [ + - + + :CBC 7 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && pgfdw_has_required_scram_options(keywords, values))
+ - ]
407 480 : 4 : return;
481 : :
1118 sfrost@snowman.net 482 [ + - ]: 3 : ereport(ERROR,
483 : : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
484 : : errmsg("password or GSSAPI delegated credentials required"),
485 : : errdetail("Non-superuser cannot connect if the server does not request a password or use GSSAPI with delegated credentials."),
486 : : errhint("Target server's authentication method must be changed or password_required=false set in the user mapping attributes.")));
487 : : }
488 : :
489 : : /*
490 : : * Construct connection params from generic options of ForeignServer and
491 : : * UserMapping. (Some of them might not be libpq options, in which case we'll
492 : : * just waste a few array slots.)
493 : : */
494 : : static void
60 jdavis@postgresql.or 495 :GNC 98 : construct_connection_params(ForeignServer *server, UserMapping *user,
496 : : const char ***p_keywords, const char ***p_values,
497 : : char **p_appname)
498 : : {
499 : : const char **keywords;
500 : : const char **values;
501 : 98 : char *appname = NULL;
502 : : int n;
503 : :
504 : : /*
505 : : * Add 4 extra slots for application_name, fallback_application_name,
506 : : * client_encoding, end marker, and 3 extra slots for scram keys and
507 : : * required scram pass-through options.
508 : : */
509 : 98 : n = list_length(server->options) + list_length(user->options) + 4 + 3;
510 : 98 : keywords = (const char **) palloc(n * sizeof(char *));
511 : 98 : values = (const char **) palloc(n * sizeof(char *));
512 : :
513 : 98 : n = 0;
514 : 196 : n += ExtractConnectionOptions(server->options,
515 : 98 : keywords + n, values + n);
516 : 196 : n += ExtractConnectionOptions(user->options,
517 : 98 : keywords + n, values + n);
518 : :
519 : : /*
520 : : * Use pgfdw_application_name as application_name if set.
521 : : *
522 : : * PQconnectdbParams() processes the parameter arrays from start to end.
523 : : * If any key word is repeated, the last value is used. Therefore note
524 : : * that pgfdw_application_name must be added to the arrays after options
525 : : * of ForeignServer are, so that it can override application_name set in
526 : : * ForeignServer.
527 : : */
528 [ + + + - ]: 98 : if (pgfdw_application_name && *pgfdw_application_name != '\0')
529 : : {
530 : 1 : keywords[n] = "application_name";
531 : 1 : values[n] = pgfdw_application_name;
532 : 1 : n++;
533 : : }
534 : :
535 : : /*
536 : : * Search the parameter arrays to find application_name setting, and
537 : : * replace escape sequences in it with status information if found. The
538 : : * arrays are searched backwards because the last value is used if
539 : : * application_name is repeatedly set.
540 : : */
541 [ + + ]: 308 : for (int i = n - 1; i >= 0; i--)
542 : : {
543 [ + + ]: 236 : if (strcmp(keywords[i], "application_name") == 0 &&
544 [ + - ]: 26 : *(values[i]) != '\0')
545 : : {
546 : : /*
547 : : * Use this application_name setting if it's not empty string even
548 : : * after any escape sequences in it are replaced.
549 : : */
550 : 26 : appname = process_pgfdw_appname(values[i]);
551 [ + - ]: 26 : if (appname[0] != '\0')
552 : : {
553 : 26 : values[i] = appname;
554 : 26 : break;
555 : : }
556 : :
557 : : /*
558 : : * This empty application_name is not used, so we set values[i] to
559 : : * NULL and keep searching the array to find the next one.
560 : : */
60 jdavis@postgresql.or 561 :UNC 0 : values[i] = NULL;
562 : 0 : pfree(appname);
563 : 0 : appname = NULL;
564 : : }
565 : : }
566 : :
60 jdavis@postgresql.or 567 :GNC 98 : *p_appname = appname;
568 : :
569 : : /* Use "postgres_fdw" as fallback_application_name */
570 : 98 : keywords[n] = "fallback_application_name";
571 : 98 : values[n] = "postgres_fdw";
572 : 98 : n++;
573 : :
574 : : /* Set client_encoding so that libpq can convert encoding properly. */
575 : 98 : keywords[n] = "client_encoding";
576 : 98 : values[n] = GetDatabaseEncodingName();
577 : 98 : n++;
578 : :
579 : : /* Add required SCRAM pass-through connection options if it's enabled. */
580 [ + + + + : 98 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && UseScramPassthrough(server, user))
+ - ]
581 : : {
582 : : int len;
583 : : int encoded_len;
584 : :
585 : 5 : keywords[n] = "scram_client_key";
586 : 5 : len = pg_b64_enc_len(sizeof(MyProcPort->scram_ClientKey));
587 : : /* don't forget the zero-terminator */
588 : 5 : values[n] = palloc0(len + 1);
589 : 5 : encoded_len = pg_b64_encode(MyProcPort->scram_ClientKey,
590 : : sizeof(MyProcPort->scram_ClientKey),
591 : 5 : (char *) values[n], len);
592 [ - + ]: 5 : if (encoded_len < 0)
60 jdavis@postgresql.or 593 [ # # ]:UNC 0 : elog(ERROR, "could not encode SCRAM client key");
4821 tgl@sss.pgh.pa.us 594 :CBC 5 : n++;
595 : :
60 jdavis@postgresql.or 596 :GNC 5 : keywords[n] = "scram_server_key";
597 : 5 : len = pg_b64_enc_len(sizeof(MyProcPort->scram_ServerKey));
598 : : /* don't forget the zero-terminator */
599 : 5 : values[n] = palloc0(len + 1);
600 : 5 : encoded_len = pg_b64_encode(MyProcPort->scram_ServerKey,
601 : : sizeof(MyProcPort->scram_ServerKey),
602 : 5 : (char *) values[n], len);
603 [ - + ]: 5 : if (encoded_len < 0)
60 jdavis@postgresql.or 604 [ # # ]:UNC 0 : elog(ERROR, "could not encode SCRAM server key");
4821 tgl@sss.pgh.pa.us 605 :CBC 5 : n++;
606 : :
607 : : /*
608 : : * Require scram-sha-256 to ensure that no other auth method is used
609 : : * when connecting with foreign server.
610 : : */
60 jdavis@postgresql.or 611 :GNC 5 : keywords[n] = "require_auth";
612 : 5 : values[n] = "scram-sha-256";
613 : 5 : n++;
614 : : }
615 : :
616 : 98 : keywords[n] = values[n] = NULL;
617 : :
618 : : /* Verify the set of connection parameters. */
619 : 98 : check_conn_params(keywords, values, user);
620 : :
621 : 94 : *p_keywords = keywords;
622 : 94 : *p_values = values;
623 : 94 : }
624 : :
625 : : /*
626 : : * Connect to remote server using specified server and user mapping properties.
627 : : */
628 : : static PGconn *
629 : 89 : connect_pg_server(ForeignServer *server, UserMapping *user)
630 : : {
631 : 89 : PGconn *volatile conn = NULL;
632 : :
633 : : /*
634 : : * Use PG_TRY block to ensure closing connection on error.
635 : : */
636 [ + + ]: 89 : PG_TRY();
637 : : {
638 : : const char **keywords;
639 : : const char **values;
640 : : char *appname;
641 : :
642 : 89 : construct_connection_params(server, user, &keywords, &values, &appname);
643 : :
644 : : /* first time, allocate or get the custom wait event */
943 michael@paquier.xyz 645 [ + + ]:CBC 85 : if (pgfdw_we_connect == 0)
646 : 14 : pgfdw_we_connect = WaitEventExtensionNew("PostgresFdwConnect");
647 : :
648 : : /* OK to make connection */
1198 andres@anarazel.de 649 : 85 : conn = libpqsrv_connect_params(keywords, values,
650 : : false, /* expand_dbname */
651 : : pgfdw_we_connect);
652 : :
4821 tgl@sss.pgh.pa.us 653 [ + - + + ]: 85 : if (!conn || PQstatus(conn) != CONNECTION_OK)
654 [ + - ]: 3 : ereport(ERROR,
655 : : (errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
656 : : errmsg("could not connect to server \"%s\"",
657 : : server->servername),
658 : : errdetail_internal("%s", pchomp(PQerrorMessage(conn)))));
659 : :
287 fujii@postgresql.org 660 :GNC 82 : PQsetNoticeReceiver(conn, libpqsrv_notice_receiver,
661 : : "received message via remote connection");
662 : :
663 : : /* Perform post-connection security checks. */
407 peter@eisentraut.org 664 :CBC 82 : pgfdw_security_check(keywords, values, user, conn);
665 : :
666 : : /* Prepare new session for use */
4820 tgl@sss.pgh.pa.us 667 : 79 : configure_remote_session(conn);
668 : :
1593 fujii@postgresql.org 669 [ + + ]: 79 : if (appname != NULL)
670 : 24 : pfree(appname);
4821 tgl@sss.pgh.pa.us 671 : 79 : pfree(keywords);
672 : 79 : pfree(values);
673 : : }
674 : 10 : PG_CATCH();
675 : : {
1198 andres@anarazel.de 676 : 10 : libpqsrv_disconnect(conn);
4821 tgl@sss.pgh.pa.us 677 : 10 : PG_RE_THROW();
678 : : }
679 [ - + ]: 79 : PG_END_TRY();
680 : :
681 : 79 : return conn;
682 : : }
683 : :
684 : : /*
685 : : * Disconnect any open connection for a connection cache entry.
686 : : */
687 : : static void
3210 688 : 67 : disconnect_pg_server(ConnCacheEntry *entry)
689 : : {
690 [ + - ]: 67 : if (entry->conn != NULL)
691 : : {
1198 andres@anarazel.de 692 : 67 : libpqsrv_disconnect(entry->conn);
3210 tgl@sss.pgh.pa.us 693 : 67 : entry->conn = NULL;
694 : : }
695 : 67 : }
696 : :
697 : : /*
698 : : * Check and return the value of password_required, if defined; otherwise,
699 : : * return true, which is the default value of it. The mapping has been
700 : : * pre-validated.
701 : : */
702 : : static bool
2328 andrew@dunslane.net 703 : 19 : UserMappingPasswordRequired(UserMapping *user)
704 : : {
705 : : ListCell *cell;
706 : :
707 [ + + + + : 34 : foreach(cell, user->options)
+ + ]
708 : : {
709 : 18 : DefElem *def = (DefElem *) lfirst(cell);
710 : :
711 [ + + ]: 18 : if (strcmp(def->defname, "password_required") == 0)
712 : 3 : return defGetBoolean(def);
713 : : }
714 : :
715 : 16 : return true;
716 : : }
717 : :
718 : : static bool
475 peter@eisentraut.org 719 : 5 : UseScramPassthrough(ForeignServer *server, UserMapping *user)
720 : : {
721 : : ListCell *cell;
722 : :
723 [ + - + - : 20 : foreach(cell, server->options)
+ - ]
724 : : {
725 : 20 : DefElem *def = (DefElem *) lfirst(cell);
726 : :
727 [ + + ]: 20 : if (strcmp(def->defname, "use_scram_passthrough") == 0)
728 : 5 : return defGetBoolean(def);
729 : : }
730 : :
475 peter@eisentraut.org 731 [ # # # # :UBC 0 : foreach(cell, user->options)
# # ]
732 : : {
733 : 0 : DefElem *def = (DefElem *) lfirst(cell);
734 : :
735 [ # # ]: 0 : if (strcmp(def->defname, "use_scram_passthrough") == 0)
736 : 0 : return defGetBoolean(def);
737 : : }
738 : :
739 : 0 : return false;
740 : : }
741 : :
742 : : /*
743 : : * For non-superusers, insist that the connstr specify a password or that the
744 : : * user provided their own GSSAPI delegated credentials. This
745 : : * prevents a password from being picked up from .pgpass, a service file, the
746 : : * environment, etc. We don't want the postgres user's passwords,
747 : : * certificates, etc to be accessible to non-superusers. (See also
748 : : * dblink_connstr_check in contrib/dblink.)
749 : : */
750 : : static void
3073 rhaas@postgresql.org 751 :CBC 98 : check_conn_params(const char **keywords, const char **values, UserMapping *user)
752 : : {
753 : : int i;
754 : :
755 : : /* no check required if superuser */
756 [ + + ]: 98 : if (superuser_arg(user->userid))
4821 tgl@sss.pgh.pa.us 757 : 82 : return;
758 : :
759 : : #ifdef ENABLE_GSS
760 : : /* ok if the user provided their own delegated credentials */
1081 bruce@momjian.us 761 [ + + ]: 16 : if (be_gssapi_get_delegation(MyProcPort))
1118 sfrost@snowman.net 762 : 3 : return;
763 : : #endif
764 : :
765 : : /* ok if params contain a non-empty password */
4821 tgl@sss.pgh.pa.us 766 [ + + ]: 89 : for (i = 0; keywords[i] != NULL; i++)
767 : : {
768 [ + + + - ]: 79 : if (strcmp(keywords[i], "password") == 0 && values[i][0] != '\0')
769 : 3 : return;
770 : : }
771 : :
772 : : /* ok if the superuser explicitly said so at user mapping creation time */
2328 andrew@dunslane.net 773 [ + + ]: 10 : if (!UserMappingPasswordRequired(user))
774 : 1 : return;
775 : :
776 : : /*
777 : : * Ok if SCRAM pass-through is being used and all required scram options
778 : : * are set correctly. If pgfdw_has_required_scram_options returns true we
779 : : * assume that UseScramPassthrough is also true since SCRAM options are
780 : : * only set when UseScramPassthrough is enabled.
781 : : */
270 peter@eisentraut.org 782 [ + - + + : 9 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && pgfdw_has_required_scram_options(keywords, values))
+ - ]
407 783 : 5 : return;
784 : :
4821 tgl@sss.pgh.pa.us 785 [ + - ]: 4 : ereport(ERROR,
786 : : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
787 : : errmsg("password or GSSAPI delegated credentials required"),
788 : : errdetail("Non-superusers must delegate GSSAPI credentials, provide a password, or enable SCRAM pass-through in user mapping.")));
789 : : }
790 : :
791 : : /*
792 : : * Issue SET commands to make sure remote session is configured properly.
793 : : *
794 : : * We do this just once at connection, assuming nothing will change the
795 : : * values later. Since we'll never send volatile function calls to the
796 : : * remote, there shouldn't be any way to break this assumption from our end.
797 : : * It's possible to think of ways to break it at the remote end, eg making
798 : : * a foreign table point to a view that includes a set_config call ---
799 : : * but once you admit the possibility of a malicious view definition,
800 : : * there are any number of ways to break things.
801 : : */
802 : : static void
4820 803 : 79 : configure_remote_session(PGconn *conn)
804 : : {
4803 805 : 79 : int remoteversion = PQserverVersion(conn);
806 : :
807 : : /* Force the search path to contain only pg_catalog (see deparse.c) */
808 : 79 : do_sql_command(conn, "SET search_path = pg_catalog");
809 : :
810 : : /*
811 : : * Set remote timezone; this is basically just cosmetic, since all
812 : : * transmitted and returned timestamptzs should specify a zone explicitly
813 : : * anyway. However it makes the regression test outputs more predictable.
814 : : *
815 : : * We don't risk setting remote zone equal to ours, since the remote
816 : : * server might use a different timezone database. Instead, use GMT
817 : : * (quoted, because very old servers are picky about case). That's
818 : : * guaranteed to work regardless of the remote's timezone database,
819 : : * because pg_tzset() hard-wires it (at least in PG 9.2 and later).
820 : : */
744 821 : 79 : do_sql_command(conn, "SET timezone = 'GMT'");
822 : :
823 : : /*
824 : : * Set values needed to ensure unambiguous data output from remote. (This
825 : : * logic should match what pg_dump does. See also set_transmission_modes
826 : : * in postgres_fdw.c.)
827 : : */
4803 828 : 79 : do_sql_command(conn, "SET datestyle = ISO");
829 [ + - ]: 79 : if (remoteversion >= 80400)
830 : 79 : do_sql_command(conn, "SET intervalstyle = postgres");
831 [ + - ]: 79 : if (remoteversion >= 90000)
832 : 79 : do_sql_command(conn, "SET extra_float_digits = 3");
833 : : else
4803 tgl@sss.pgh.pa.us 834 :UBC 0 : do_sql_command(conn, "SET extra_float_digits = 2");
4803 tgl@sss.pgh.pa.us 835 :CBC 79 : }
836 : :
837 : : /*
838 : : * Convenience subroutine to issue a non-data-returning SQL command to remote
839 : : */
840 : : void
841 : 1918 : do_sql_command(PGconn *conn, const char *sql)
842 : : {
1531 efujita@postgresql.o 843 : 1918 : do_sql_command_begin(conn, sql);
844 : 1918 : do_sql_command_end(conn, sql, false);
845 : 1915 : }
846 : :
847 : : static void
848 : 1936 : do_sql_command_begin(PGconn *conn, const char *sql)
849 : : {
3254 rhaas@postgresql.org 850 [ - + ]: 1936 : if (!PQsendQuery(conn, sql))
280 tgl@sss.pgh.pa.us 851 :UNC 0 : pgfdw_report_error(NULL, conn, sql);
1531 efujita@postgresql.o 852 :CBC 1936 : }
853 : :
854 : : static void
855 : 1936 : do_sql_command_end(PGconn *conn, const char *sql, bool consume_input)
856 : : {
857 : : PGresult *res;
858 : :
859 : : /*
860 : : * If requested, consume whatever data is available from the socket. (Note
861 : : * that if all data is available, this allows pgfdw_get_result to call
862 : : * PQgetResult without forcing the overhead of WaitLatchOrSocket, which
863 : : * would be large compared to the overhead of PQconsumeInput.)
864 : : */
865 [ + + - + ]: 1936 : if (consume_input && !PQconsumeInput(conn))
280 tgl@sss.pgh.pa.us 866 :UNC 0 : pgfdw_report_error(NULL, conn, sql);
848 noah@leadboat.com 867 :CBC 1936 : res = pgfdw_get_result(conn);
4820 tgl@sss.pgh.pa.us 868 [ + + ]: 1936 : if (PQresultStatus(res) != PGRES_COMMAND_OK)
280 tgl@sss.pgh.pa.us 869 :GNC 3 : pgfdw_report_error(res, conn, sql);
4820 tgl@sss.pgh.pa.us 870 :CBC 1933 : PQclear(res);
871 : 1933 : }
872 : :
873 : : /*
874 : : * Start remote transaction or subtransaction, if needed.
875 : : *
876 : : * Note that we always use at least REPEATABLE READ in the remote session.
877 : : * This is so that, if a query initiates multiple scans of the same or
878 : : * different foreign tables, we will get snapshot-consistent results from
879 : : * those scans. A disadvantage is that we can't provide sane emulation of
880 : : * READ COMMITTED behavior --- it would be nice if we had some other way to
881 : : * control which remote queries share a snapshot.
882 : : *
883 : : * Note also that we always start the remote transaction with the same
884 : : * read/write and deferrable properties as the local transaction, and start
885 : : * the remote subtransaction with the same read/write property as the local
886 : : * subtransaction.
887 : : */
888 : : static void
4821 889 : 2280 : begin_remote_xact(ConnCacheEntry *entry)
890 : : {
891 : 2280 : int curlevel = GetCurrentTransactionNestLevel();
892 : :
893 : : /*
894 : : * If the current local (sub)transaction is read-only, set the topmost
895 : : * read-only local transaction's nesting level if we haven't yet.
896 : : *
897 : : * Note: once it's set, it's retained until the topmost read-only local
898 : : * transaction is committed/aborted (see pgfdw_xact_callback and
899 : : * pgfdw_subxact_callback).
900 : : */
30 efujita@postgresql.o 901 [ + + ]:GNC 2280 : if (XactReadOnly)
902 : : {
903 [ + + ]: 10 : if (read_only_level == 0)
904 : 9 : read_only_level = GetTopReadOnlyTransactionNestLevel();
905 [ - + ]: 10 : Assert(read_only_level > 0);
906 : : }
907 : : else
908 [ - + ]: 2270 : Assert(read_only_level == 0);
909 : :
910 : : /*
911 : : * Start main transaction if we haven't yet; otherwise, change the current
912 : : * remote (sub)transaction's read/write mode if needed.
913 : : */
4821 tgl@sss.pgh.pa.us 914 [ + + ]:CBC 2280 : if (entry->xact_depth <= 0)
915 : : {
916 : : /*
917 : : * This is the case when we haven't yet started a main transaction.
918 : : */
919 : : StringInfoData sql;
30 efujita@postgresql.o 920 :GNC 778 : bool ro = (read_only_level == 1);
921 : :
4821 tgl@sss.pgh.pa.us 922 [ - + ]:CBC 778 : elog(DEBUG3, "starting remote transaction on connection %p",
923 : : entry->conn);
924 : :
30 efujita@postgresql.o 925 :GNC 778 : initStringInfo(&sql);
926 : 778 : appendStringInfoString(&sql, "START TRANSACTION ISOLATION LEVEL ");
4821 tgl@sss.pgh.pa.us 927 [ + + ]:CBC 778 : if (IsolationIsSerializable())
30 efujita@postgresql.o 928 :GNC 3 : appendStringInfoString(&sql, "SERIALIZABLE");
929 : : else
930 : 775 : appendStringInfoString(&sql, "REPEATABLE READ");
931 [ + + ]: 778 : if (ro)
932 : 3 : appendStringInfoString(&sql, " READ ONLY");
933 [ + + ]: 778 : if (XactDeferrable)
934 : 2 : appendStringInfoString(&sql, " DEFERRABLE");
3254 rhaas@postgresql.org 935 :CBC 778 : entry->changing_xact_state = true;
30 efujita@postgresql.o 936 :GNC 778 : do_sql_command(entry->conn, sql.data);
4821 tgl@sss.pgh.pa.us 937 :CBC 777 : entry->xact_depth = 1;
30 efujita@postgresql.o 938 [ + + ]:GNC 777 : if (ro)
939 : : {
940 [ - + ]: 3 : Assert(!entry->xact_read_only);
941 : 3 : entry->xact_read_only = true;
942 : : }
3254 rhaas@postgresql.org 943 :CBC 777 : entry->changing_xact_state = false;
944 : : }
30 efujita@postgresql.o 945 [ + + ]:GNC 1502 : else if (!entry->xact_read_only)
946 : : {
947 : : /*
948 : : * The remote (sub)transaction has been opened in read-write mode.
949 : : */
950 [ + + - + ]: 1501 : Assert(read_only_level == 0 ||
951 : : entry->xact_depth <= read_only_level);
952 : :
953 : : /*
954 : : * If its nesting depth matches read_only_level, it means that the
955 : : * local read-write (sub)transaction that started it has changed to
956 : : * read-only after that; in which case change it to read-only as well.
957 : : * Otherwise, the local (sub)transaction is still read-write, so there
958 : : * is no need to do anything.
959 : : */
960 [ + + ]: 1501 : if (entry->xact_depth == read_only_level)
961 : : {
962 : 4 : entry->changing_xact_state = true;
963 : 4 : do_sql_command(entry->conn, "SET transaction_read_only = on");
964 : 4 : entry->xact_read_only = true;
965 : 4 : entry->changing_xact_state = false;
966 : : }
967 : : }
968 : : else
969 : : {
970 : : /*
971 : : * The remote (sub)transaction has been opened in read-only mode.
972 : : */
973 [ + - - + ]: 1 : Assert(read_only_level > 0 &&
974 : : entry->xact_depth >= read_only_level);
975 : :
976 : : /*
977 : : * The local read-only (sub)transaction that started it is guaranteed
978 : : * to be still read-only (see check_transaction_read_only), so there
979 : : * is no need to do anything.
980 : : */
981 : : }
982 : :
983 : : /*
984 : : * If we're in a subtransaction, stack up savepoints to match our level.
985 : : * This ensures we can rollback just the desired effects when a
986 : : * subtransaction aborts.
987 : : */
4821 tgl@sss.pgh.pa.us 988 [ + + ]:CBC 2298 : while (entry->xact_depth < curlevel)
989 : : {
990 : : StringInfoData sql;
30 efujita@postgresql.o 991 :GNC 20 : bool ro = (entry->xact_depth + 1 == read_only_level);
992 : :
993 : 20 : initStringInfo(&sql);
994 : 20 : appendStringInfo(&sql, "SAVEPOINT s%d", entry->xact_depth + 1);
995 [ + + ]: 20 : if (ro)
996 : 2 : appendStringInfoString(&sql, "; SET transaction_read_only = on");
3254 rhaas@postgresql.org 997 :CBC 20 : entry->changing_xact_state = true;
30 efujita@postgresql.o 998 :GNC 20 : do_sql_command(entry->conn, sql.data);
4821 tgl@sss.pgh.pa.us 999 :CBC 19 : entry->xact_depth++;
30 efujita@postgresql.o 1000 [ + + ]:GNC 19 : if (ro)
1001 : : {
1002 [ - + ]: 2 : Assert(!entry->xact_read_only);
1003 : 2 : entry->xact_read_only = true;
1004 : : }
3254 rhaas@postgresql.org 1005 :CBC 19 : entry->changing_xact_state = false;
1006 : : }
4821 tgl@sss.pgh.pa.us 1007 : 2278 : }
1008 : :
1009 : : /*
1010 : : * Release connection reference count created by calling GetConnection.
1011 : : */
1012 : : void
1013 : 2205 : ReleaseConnection(PGconn *conn)
1014 : : {
1015 : : /*
1016 : : * Currently, we don't actually track connection references because all
1017 : : * cleanup is managed on a transaction or subtransaction basis instead. So
1018 : : * there's nothing to do here.
1019 : : */
1020 : 2205 : }
1021 : :
1022 : : /*
1023 : : * Assign a "unique" number for a cursor.
1024 : : *
1025 : : * These really only need to be unique per connection within a transaction.
1026 : : * For the moment we ignore the per-connection point and assign them across
1027 : : * all connections in the transaction, but we ask for the connection to be
1028 : : * supplied in case we want to refine that.
1029 : : *
1030 : : * Note that even if wraparound happens in a very long transaction, actual
1031 : : * collisions are highly improbable; just be sure to use %u not %d to print.
1032 : : */
1033 : : unsigned int
1034 : 575 : GetCursorNumber(PGconn *conn)
1035 : : {
1036 : 575 : return ++cursor_number;
1037 : : }
1038 : :
1039 : : /*
1040 : : * Assign a "unique" number for a prepared statement.
1041 : : *
1042 : : * This works much like GetCursorNumber, except that we never reset the counter
1043 : : * within a session. That's because we can't be 100% sure we've gotten rid
1044 : : * of all prepared statements on all connections, and it's not really worth
1045 : : * increasing the risk of prepared-statement name collisions by resetting.
1046 : : */
1047 : : unsigned int
4804 1048 : 187 : GetPrepStmtNumber(PGconn *conn)
1049 : : {
1050 : 187 : return ++prep_stmt_number;
1051 : : }
1052 : :
1053 : : /*
1054 : : * Submit a query and wait for the result.
1055 : : *
1056 : : * Since we don't use non-blocking mode, this can't process interrupts while
1057 : : * pushing the query text to the server. That risk is relatively small, so we
1058 : : * ignore that for now.
1059 : : *
1060 : : * Caller is responsible for the error handling on the result.
1061 : : */
1062 : : PGresult *
1861 efujita@postgresql.o 1063 : 4181 : pgfdw_exec_query(PGconn *conn, const char *query, PgFdwConnState *state)
1064 : : {
1065 : : /* First, process a pending asynchronous request, if any. */
1066 [ + + + + ]: 4181 : if (state && state->pendingAreq)
1067 : 4 : process_pending_request(state->pendingAreq);
1068 : :
3666 rhaas@postgresql.org 1069 [ - + ]: 4181 : if (!PQsendQuery(conn, query))
848 noah@leadboat.com 1070 :UBC 0 : return NULL;
848 noah@leadboat.com 1071 :CBC 4181 : return pgfdw_get_result(conn);
1072 : : }
1073 : :
1074 : : /*
1075 : : * Wrap libpqsrv_get_result_last(), adding wait event.
1076 : : *
1077 : : * Caller is responsible for the error handling on the result.
1078 : : */
1079 : : PGresult *
1080 : 8436 : pgfdw_get_result(PGconn *conn)
1081 : : {
1082 : 8436 : return libpqsrv_get_result_last(conn, pgfdw_we_get_result);
1083 : : }
1084 : :
1085 : : /*
1086 : : * Report an error we got from the remote server.
1087 : : *
1088 : : * Callers should use pgfdw_report_error() to throw an error, or use
1089 : : * pgfdw_report() for lesser message levels. (We make this distinction
1090 : : * so that pgfdw_report_error() can be marked noreturn.)
1091 : : *
1092 : : * res: PGresult containing the error (might be NULL)
1093 : : * conn: connection we did the query on
1094 : : * sql: NULL, or text of remote command we tried to execute
1095 : : *
1096 : : * If "res" is not NULL, it'll be PQclear'ed here (unless we throw error,
1097 : : * in which case memory context cleanup will clear it eventually).
1098 : : *
1099 : : * Note: callers that choose not to throw ERROR for a remote error are
1100 : : * responsible for making sure that the associated ConnCacheEntry gets
1101 : : * marked with have_error = true.
1102 : : */
1103 : : void
280 tgl@sss.pgh.pa.us 1104 :GNC 24 : pgfdw_report_error(PGresult *res, PGconn *conn, const char *sql)
1105 : : {
1106 : 24 : pgfdw_report_internal(ERROR, res, conn, sql);
280 tgl@sss.pgh.pa.us 1107 :UNC 0 : pg_unreachable();
1108 : : }
1109 : :
1110 : : void
1111 : 0 : pgfdw_report(int elevel, PGresult *res, PGconn *conn, const char *sql)
1112 : : {
1113 [ # # ]: 0 : Assert(elevel < ERROR); /* use pgfdw_report_error for that */
1114 : 0 : pgfdw_report_internal(elevel, res, conn, sql);
1115 : 0 : }
1116 : :
1117 : : static void
280 tgl@sss.pgh.pa.us 1118 :GNC 24 : pgfdw_report_internal(int elevel, PGresult *res, PGconn *conn,
1119 : : const char *sql)
1120 : : {
284 1121 : 24 : char *diag_sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1122 : 24 : char *message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1123 : 24 : char *message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL);
1124 : 24 : char *message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT);
1125 : 24 : char *message_context = PQresultErrorField(res, PG_DIAG_CONTEXT);
1126 : : int sqlstate;
1127 : :
1128 [ + + ]: 24 : if (diag_sqlstate)
1129 : 22 : sqlstate = MAKE_SQLSTATE(diag_sqlstate[0],
1130 : : diag_sqlstate[1],
1131 : : diag_sqlstate[2],
1132 : : diag_sqlstate[3],
1133 : : diag_sqlstate[4]);
1134 : : else
1135 : 2 : sqlstate = ERRCODE_CONNECTION_FAILURE;
1136 : :
1137 : : /*
1138 : : * If we don't get a message from the PGresult, try the PGconn. This is
1139 : : * needed because for connection-level failures, PQgetResult may just
1140 : : * return NULL, not a PGresult at all.
1141 : : */
1142 [ + + ]: 24 : if (message_primary == NULL)
1143 : 2 : message_primary = pchomp(PQerrorMessage(conn));
1144 : :
1145 [ + - + - : 24 : ereport(elevel,
+ - + + +
+ + + +
- ]
1146 : : (errcode(sqlstate),
1147 : : (message_primary != NULL && message_primary[0] != '\0') ?
1148 : : errmsg_internal("%s", message_primary) :
1149 : : errmsg("could not obtain message string for remote error"),
1150 : : message_detail ? errdetail_internal("%s", message_detail) : 0,
1151 : : message_hint ? errhint("%s", message_hint) : 0,
1152 : : message_context ? errcontext("%s", message_context) : 0,
1153 : : sql ? errcontext("remote SQL command: %s", sql) : 0));
284 tgl@sss.pgh.pa.us 1154 :UNC 0 : PQclear(res);
4821 tgl@sss.pgh.pa.us 1155 :UBC 0 : }
1156 : :
1157 : : /*
1158 : : * pgfdw_xact_callback --- cleanup at main-transaction end.
1159 : : *
1160 : : * This runs just late enough that it must not enter user-defined code
1161 : : * locally. (Entering such code on the remote side is fine. Its remote
1162 : : * COMMIT TRANSACTION may run deferred triggers.)
1163 : : */
1164 : : static void
4821 tgl@sss.pgh.pa.us 1165 :CBC 4200 : pgfdw_xact_callback(XactEvent event, void *arg)
1166 : : {
1167 : : HASH_SEQ_STATUS scan;
1168 : : ConnCacheEntry *entry;
1531 efujita@postgresql.o 1169 : 4200 : List *pending_entries = NIL;
1125 1170 : 4200 : List *cancel_requested = NIL;
1171 : :
1172 : : /* Quick exit if no connections were touched in this transaction. */
4821 tgl@sss.pgh.pa.us 1173 [ + + ]: 4200 : if (!xact_got_connection)
1174 : 3451 : return;
1175 : :
1176 : : /*
1177 : : * Scan all connection cache entries to find open remote transactions, and
1178 : : * close them.
1179 : : */
1180 : 749 : hash_seq_init(&scan, ConnectionHash);
1181 [ + + ]: 3926 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1182 : : {
1183 : : PGresult *res;
1184 : :
1185 : : /* Ignore cache entry if no open connection right now */
4474 1186 [ + + ]: 3178 : if (entry->conn == NULL)
4821 1187 : 1854 : continue;
1188 : :
1189 : : /* If it has an open remote transaction, try to close it */
4474 1190 [ + + ]: 1324 : if (entry->xact_depth > 0)
1191 : : {
1192 [ - + ]: 778 : elog(DEBUG3, "closing remote transaction on connection %p",
1193 : : entry->conn);
1194 : :
1195 [ + + - + : 778 : switch (event)
- ]
1196 : : {
4023 rhaas@postgresql.org 1197 : 720 : case XACT_EVENT_PARALLEL_PRE_COMMIT:
1198 : : case XACT_EVENT_PRE_COMMIT:
1199 : :
1200 : : /*
1201 : : * If abort cleanup previously failed for this connection,
1202 : : * we can't issue any more commands against it.
1203 : : */
3254 1204 : 720 : pgfdw_reject_incomplete_xact_state_change(entry);
1205 : :
1206 : : /* Commit all remote transactions during pre-commit */
1207 : 720 : entry->changing_xact_state = true;
1531 efujita@postgresql.o 1208 [ + + ]: 720 : if (entry->parallel_commit)
1209 : : {
1210 : 16 : do_sql_command_begin(entry->conn, "COMMIT TRANSACTION");
1211 : 16 : pending_entries = lappend(pending_entries, entry);
1212 : 16 : continue;
1213 : : }
4474 tgl@sss.pgh.pa.us 1214 : 704 : do_sql_command(entry->conn, "COMMIT TRANSACTION");
3254 rhaas@postgresql.org 1215 : 704 : entry->changing_xact_state = false;
1216 : :
1217 : : /*
1218 : : * If there were any errors in subtransactions, and we
1219 : : * made prepared statements, do a DEALLOCATE ALL to make
1220 : : * sure we get rid of all prepared statements. This is
1221 : : * annoying and not terribly bulletproof, but it's
1222 : : * probably not worth trying harder.
1223 : : *
1224 : : * DEALLOCATE ALL only exists in 8.3 and later, so this
1225 : : * constrains how old a server postgres_fdw can
1226 : : * communicate with. We intentionally ignore errors in
1227 : : * the DEALLOCATE, so that we can hobble along to some
1228 : : * extent with older servers (leaking prepared statements
1229 : : * as we go; but we don't really support update operations
1230 : : * pre-8.3 anyway).
1231 : : */
4804 tgl@sss.pgh.pa.us 1232 [ + + - + ]: 704 : if (entry->have_prep_stmt && entry->have_error)
1233 : : {
848 noah@leadboat.com 1234 :UBC 0 : res = pgfdw_exec_query(entry->conn, "DEALLOCATE ALL",
1235 : : NULL);
4804 tgl@sss.pgh.pa.us 1236 : 0 : PQclear(res);
1237 : : }
4804 tgl@sss.pgh.pa.us 1238 :CBC 704 : entry->have_prep_stmt = false;
1239 : 704 : entry->have_error = false;
4474 1240 : 704 : break;
1241 : 1 : case XACT_EVENT_PRE_PREPARE:
1242 : :
1243 : : /*
1244 : : * We disallow any remote transactions, since it's not
1245 : : * very reasonable to hold them open until the prepared
1246 : : * transaction is committed. For the moment, throw error
1247 : : * unconditionally; later we might allow read-only cases.
1248 : : * Note that the error will cause us to come right back
1249 : : * here with event == XACT_EVENT_ABORT, so we'll clean up
1250 : : * the connection state at that point.
1251 : : */
1252 [ + - ]: 1 : ereport(ERROR,
1253 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1254 : : errmsg("cannot PREPARE a transaction that has operated on postgres_fdw foreign tables")));
1255 : : break;
4023 rhaas@postgresql.org 1256 :UBC 0 : case XACT_EVENT_PARALLEL_COMMIT:
1257 : : case XACT_EVENT_COMMIT:
1258 : : case XACT_EVENT_PREPARE:
1259 : : /* Pre-commit should have closed the open transaction */
4474 tgl@sss.pgh.pa.us 1260 [ # # ]: 0 : elog(ERROR, "missed cleaning up connection during pre-commit");
1261 : : break;
4023 rhaas@postgresql.org 1262 :CBC 57 : case XACT_EVENT_PARALLEL_ABORT:
1263 : : case XACT_EVENT_ABORT:
1264 : : /* Rollback all remote transactions during abort */
1125 efujita@postgresql.o 1265 [ + + ]: 57 : if (entry->parallel_abort)
1266 : : {
1267 [ + - ]: 4 : if (pgfdw_abort_cleanup_begin(entry, true,
1268 : : &pending_entries,
1269 : : &cancel_requested))
1270 : 4 : continue;
1271 : : }
1272 : : else
1273 : 53 : pgfdw_abort_cleanup(entry, true);
4474 tgl@sss.pgh.pa.us 1274 : 53 : break;
1275 : : }
1276 : : }
1277 : :
1278 : : /* Reset state to show we're out of a transaction */
1531 efujita@postgresql.o 1279 : 1303 : pgfdw_reset_xact_state(entry, true);
1280 : : }
1281 : :
1282 : : /* If there are any pending connections, finish cleaning them up */
1125 1283 [ + + - + ]: 748 : if (pending_entries || cancel_requested)
1284 : : {
1285 [ + - + + ]: 15 : if (event == XACT_EVENT_PARALLEL_PRE_COMMIT ||
1286 : : event == XACT_EVENT_PRE_COMMIT)
1287 : : {
1288 [ - + ]: 13 : Assert(cancel_requested == NIL);
1289 : 13 : pgfdw_finish_pre_commit_cleanup(pending_entries);
1290 : : }
1291 : : else
1292 : : {
1293 [ + - - + ]: 2 : Assert(event == XACT_EVENT_PARALLEL_ABORT ||
1294 : : event == XACT_EVENT_ABORT);
1295 : 2 : pgfdw_finish_abort_cleanup(pending_entries, cancel_requested,
1296 : : true);
1297 : : }
1298 : : }
1299 : :
1300 : : /*
1301 : : * Regardless of the event type, we can now mark ourselves as out of the
1302 : : * transaction. (Note: if we are here during PRE_COMMIT or PRE_PREPARE,
1303 : : * this saves a useless scan of the hashtable during COMMIT or PREPARE.)
1304 : : */
4821 tgl@sss.pgh.pa.us 1305 : 748 : xact_got_connection = false;
1306 : :
1307 : : /* Also reset cursor numbering for next transaction */
1308 : 748 : cursor_number = 0;
1309 : :
1310 : : /* Likewise for read_only_level */
30 efujita@postgresql.o 1311 :GNC 748 : read_only_level = 0;
1312 : : }
1313 : :
1314 : : /*
1315 : : * pgfdw_subxact_callback --- cleanup at subtransaction end.
1316 : : */
1317 : : static void
4821 tgl@sss.pgh.pa.us 1318 :CBC 58 : pgfdw_subxact_callback(SubXactEvent event, SubTransactionId mySubid,
1319 : : SubTransactionId parentSubid, void *arg)
1320 : : {
1321 : : HASH_SEQ_STATUS scan;
1322 : : ConnCacheEntry *entry;
1323 : : int curlevel;
1531 efujita@postgresql.o 1324 : 58 : List *pending_entries = NIL;
1125 1325 : 58 : List *cancel_requested = NIL;
1326 : :
1327 : : /* Nothing to do at subxact start, nor after commit. */
4821 tgl@sss.pgh.pa.us 1328 [ + + + + ]: 58 : if (!(event == SUBXACT_EVENT_PRE_COMMIT_SUB ||
1329 : : event == SUBXACT_EVENT_ABORT_SUB))
1330 : 35 : return;
1331 : :
1332 : : /* Quick exit if no connections were touched in this transaction. */
1333 [ - + ]: 23 : if (!xact_got_connection)
4821 tgl@sss.pgh.pa.us 1334 :UBC 0 : return;
1335 : :
1336 : : /*
1337 : : * Scan all connection cache entries to find open remote subtransactions
1338 : : * of the current level, and close them.
1339 : : */
4821 tgl@sss.pgh.pa.us 1340 :CBC 23 : curlevel = GetCurrentTransactionNestLevel();
1341 : 23 : hash_seq_init(&scan, ConnectionHash);
1342 [ + + ]: 182 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1343 : : {
1344 : : char sql[100];
1345 : :
1346 : : /*
1347 : : * We only care about connections with open remote subtransactions of
1348 : : * the current level.
1349 : : */
1350 [ + + + + ]: 159 : if (entry->conn == NULL || entry->xact_depth < curlevel)
1351 : 146 : continue;
1352 : :
1353 [ - + ]: 19 : if (entry->xact_depth > curlevel)
4821 tgl@sss.pgh.pa.us 1354 [ # # ]:UBC 0 : elog(ERROR, "missed cleaning up remote subtransaction at level %d",
1355 : : entry->xact_depth);
1356 : :
4821 tgl@sss.pgh.pa.us 1357 [ + + ]:CBC 19 : if (event == SUBXACT_EVENT_PRE_COMMIT_SUB)
1358 : : {
1359 : : /*
1360 : : * If abort cleanup previously failed for this connection, we
1361 : : * can't issue any more commands against it.
1362 : : */
3254 rhaas@postgresql.org 1363 : 7 : pgfdw_reject_incomplete_xact_state_change(entry);
1364 : :
1365 : : /* Commit all remote subtransactions during pre-commit */
4821 tgl@sss.pgh.pa.us 1366 : 7 : snprintf(sql, sizeof(sql), "RELEASE SAVEPOINT s%d", curlevel);
3254 rhaas@postgresql.org 1367 : 7 : entry->changing_xact_state = true;
1531 efujita@postgresql.o 1368 [ + + ]: 7 : if (entry->parallel_commit)
1369 : : {
1370 : 2 : do_sql_command_begin(entry->conn, sql);
1371 : 2 : pending_entries = lappend(pending_entries, entry);
1372 : 2 : continue;
1373 : : }
4803 tgl@sss.pgh.pa.us 1374 : 5 : do_sql_command(entry->conn, sql);
3254 rhaas@postgresql.org 1375 : 5 : entry->changing_xact_state = false;
1376 : : }
1377 : : else
1378 : : {
1379 : : /* Rollback all remote subtransactions during abort */
1125 efujita@postgresql.o 1380 [ + + ]: 12 : if (entry->parallel_abort)
1381 : : {
1382 [ + - ]: 4 : if (pgfdw_abort_cleanup_begin(entry, false,
1383 : : &pending_entries,
1384 : : &cancel_requested))
1385 : 4 : continue;
1386 : : }
1387 : : else
1388 : 8 : pgfdw_abort_cleanup(entry, false);
1389 : : }
1390 : :
1391 : : /* OK, we're outta that level of subtransaction */
1531 1392 : 13 : pgfdw_reset_xact_state(entry, false);
1393 : : }
1394 : :
1395 : : /* If there are any pending connections, finish cleaning them up */
1125 1396 [ + + - + ]: 23 : if (pending_entries || cancel_requested)
1397 : : {
1398 [ + + ]: 3 : if (event == SUBXACT_EVENT_PRE_COMMIT_SUB)
1399 : : {
1400 [ - + ]: 1 : Assert(cancel_requested == NIL);
1401 : 1 : pgfdw_finish_pre_subcommit_cleanup(pending_entries, curlevel);
1402 : : }
1403 : : else
1404 : : {
1405 [ - + ]: 2 : Assert(event == SUBXACT_EVENT_ABORT_SUB);
1406 : 2 : pgfdw_finish_abort_cleanup(pending_entries, cancel_requested,
1407 : : false);
1408 : : }
1409 : : }
1410 : :
1411 : : /* If in read_only_level, reset it */
30 efujita@postgresql.o 1412 [ + + ]:GNC 23 : if (curlevel == read_only_level)
1413 : 3 : read_only_level = 0;
1414 : : }
1415 : :
1416 : : /*
1417 : : * Connection invalidation callback function
1418 : : *
1419 : : * After a change to a pg_foreign_server or pg_user_mapping catalog entry,
1420 : : * close connections depending on that entry immediately if current transaction
1421 : : * has not used those connections yet. Otherwise, mark those connections as
1422 : : * invalid and then make pgfdw_xact_callback() close them at the end of current
1423 : : * transaction, since they cannot be closed in the midst of the transaction
1424 : : * using them. Closed connections will be remade at the next opportunity if
1425 : : * necessary.
1426 : : *
1427 : : * Although most cache invalidation callbacks blow away all the related stuff
1428 : : * regardless of the given hashvalue, connections are expensive enough that
1429 : : * it's worth trying to avoid that.
1430 : : *
1431 : : * NB: We could avoid unnecessary disconnection more strictly by examining
1432 : : * individual option values, but it seems too much effort for the gain.
1433 : : */
1434 : : static void
76 michael@paquier.xyz 1435 : 188 : pgfdw_inval_callback(Datum arg, SysCacheIdentifier cacheid, uint32 hashvalue)
1436 : : {
1437 : : HASH_SEQ_STATUS scan;
1438 : : ConnCacheEntry *entry;
1439 : :
3210 tgl@sss.pgh.pa.us 1440 [ + + - + ]:CBC 188 : Assert(cacheid == FOREIGNSERVEROID || cacheid == USERMAPPINGOID);
1441 : :
1442 : : /* ConnectionHash must exist already, if we're registered */
1443 : 188 : hash_seq_init(&scan, ConnectionHash);
1444 [ + + ]: 1222 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1445 : : {
1446 : : /* Ignore invalid entries */
1447 [ + + ]: 1034 : if (entry->conn == NULL)
1448 : 838 : continue;
1449 : :
1450 : : /* hashvalue == 0 means a cache reset, must clear all state */
1451 [ + - + + ]: 196 : if (hashvalue == 0 ||
1452 : 140 : (cacheid == FOREIGNSERVEROID &&
1453 [ + + + + ]: 196 : entry->server_hashvalue == hashvalue) ||
1454 : 56 : (cacheid == USERMAPPINGOID &&
1455 [ + + ]: 56 : entry->mapping_hashvalue == hashvalue))
1456 : : {
1457 : : /*
1458 : : * Close the connection immediately if it's not used yet in this
1459 : : * transaction. Otherwise mark it as invalid so that
1460 : : * pgfdw_xact_callback() can close it at the end of this
1461 : : * transaction.
1462 : : */
1954 fujii@postgresql.org 1463 [ + + ]: 59 : if (entry->xact_depth == 0)
1464 : : {
1465 [ - + ]: 56 : elog(DEBUG3, "discarding connection %p", entry->conn);
1466 : 56 : disconnect_pg_server(entry);
1467 : : }
1468 : : else
1469 : 3 : entry->invalidated = true;
1470 : : }
1471 : : }
3210 tgl@sss.pgh.pa.us 1472 : 188 : }
1473 : :
1474 : : /*
1475 : : * Raise an error if the given connection cache entry is marked as being
1476 : : * in the middle of an xact state change. This should be called at which no
1477 : : * such change is expected to be in progress; if one is found to be in
1478 : : * progress, it means that we aborted in the middle of a previous state change
1479 : : * and now don't know what the remote transaction state actually is.
1480 : : * Such connections can't safely be further used. Re-establishing the
1481 : : * connection would change the snapshot and roll back any writes already
1482 : : * performed, so that's not an option, either. Thus, we must abort.
1483 : : */
1484 : : static void
3254 rhaas@postgresql.org 1485 : 3016 : pgfdw_reject_incomplete_xact_state_change(ConnCacheEntry *entry)
1486 : : {
1487 : : ForeignServer *server;
1488 : :
1489 : : /* nothing to do for inactive entries and entries of sane state */
3210 tgl@sss.pgh.pa.us 1490 [ + + + - ]: 3016 : if (entry->conn == NULL || !entry->changing_xact_state)
3254 rhaas@postgresql.org 1491 : 3016 : return;
1492 : :
1493 : : /* make sure this entry is inactive */
3210 tgl@sss.pgh.pa.us 1494 :UBC 0 : disconnect_pg_server(entry);
1495 : :
1496 : : /* find server name to be shown in the message below */
1936 fujii@postgresql.org 1497 : 0 : server = GetForeignServer(entry->serverid);
1498 : :
3254 rhaas@postgresql.org 1499 [ # # ]: 0 : ereport(ERROR,
1500 : : (errcode(ERRCODE_CONNECTION_EXCEPTION),
1501 : : errmsg("connection to server \"%s\" was lost",
1502 : : server->servername)));
1503 : : }
1504 : :
1505 : : /*
1506 : : * Reset state to show we're out of a (sub)transaction.
1507 : : */
1508 : : static void
1531 efujita@postgresql.o 1509 :CBC 1342 : pgfdw_reset_xact_state(ConnCacheEntry *entry, bool toplevel)
1510 : : {
1511 [ + + ]: 1342 : if (toplevel)
1512 : : {
1513 : : /* Reset state to show we're out of a transaction */
1514 : 1323 : entry->xact_depth = 0;
1515 : :
1516 : : /* Reset xact r/o state */
30 efujita@postgresql.o 1517 :GNC 1323 : entry->xact_read_only = false;
1518 : :
1519 : : /*
1520 : : * If the connection isn't in a good idle state, it is marked as
1521 : : * invalid or keep_connections option of its server is disabled, then
1522 : : * discard it to recover. Next GetConnection will open a new
1523 : : * connection.
1524 : : */
1531 efujita@postgresql.o 1525 [ + + + - ]:CBC 2645 : if (PQstatus(entry->conn) != CONNECTION_OK ||
1526 : 1322 : PQtransactionStatus(entry->conn) != PQTRANS_IDLE ||
1527 [ + - ]: 1322 : entry->changing_xact_state ||
1528 [ + + ]: 1322 : entry->invalidated ||
1529 [ + + ]: 1320 : !entry->keep_connections)
1530 : : {
1531 [ - + ]: 4 : elog(DEBUG3, "discarding connection %p", entry->conn);
1532 : 4 : disconnect_pg_server(entry);
1533 : : }
1534 : : }
1535 : : else
1536 : : {
1537 : : /* Reset state to show we're out of a subtransaction */
1538 : 19 : entry->xact_depth--;
1539 : :
1540 : : /* If in read_only_level, reset xact r/o state */
30 efujita@postgresql.o 1541 [ + + ]:GNC 19 : if (entry->xact_depth + 1 == read_only_level)
1542 : 4 : entry->xact_read_only = false;
1543 : : }
1531 efujita@postgresql.o 1544 :CBC 1342 : }
1545 : :
1546 : : /*
1547 : : * Cancel the currently-in-progress query (whose query text we do not have)
1548 : : * and ignore the result. Returns true if we successfully cancel the query
1549 : : * and discard any pending result, and false if not.
1550 : : *
1551 : : * It's not a huge problem if we throw an ERROR here, but if we get into error
1552 : : * recursion trouble, we'll end up slamming the connection shut, which will
1553 : : * necessitate failing the entire toplevel transaction even if subtransactions
1554 : : * were used. Try to use WARNING where we can.
1555 : : *
1556 : : * XXX: if the query was one sent by fetch_more_data_begin(), we could get the
1557 : : * query text from the pendingAreq saved in the per-connection state, then
1558 : : * report the query using it.
1559 : : */
1560 : : static bool
3254 rhaas@postgresql.org 1561 : 2 : pgfdw_cancel_query(PGconn *conn)
1562 : : {
498 tgl@sss.pgh.pa.us 1563 : 2 : TimestampTz now = GetCurrentTimestamp();
1564 : : TimestampTz endtime;
1565 : : TimestampTz retrycanceltime;
1566 : :
1567 : : /*
1568 : : * If it takes too long to cancel the query and discard the result, assume
1569 : : * the connection is dead.
1570 : : */
1571 : 2 : endtime = TimestampTzPlusMilliseconds(now, CONNECTION_CLEANUP_TIMEOUT);
1572 : :
1573 : : /*
1574 : : * Also, lose patience and re-issue the cancel request after a little bit.
1575 : : * (This serves to close some race conditions.)
1576 : : */
1577 : 2 : retrycanceltime = TimestampTzPlusMilliseconds(now, RETRY_CANCEL_TIMEOUT);
1578 : :
768 alvherre@alvh.no-ip. 1579 [ - + ]: 2 : if (!pgfdw_cancel_query_begin(conn, endtime))
1125 efujita@postgresql.o 1580 :UBC 0 : return false;
498 tgl@sss.pgh.pa.us 1581 :CBC 2 : return pgfdw_cancel_query_end(conn, endtime, retrycanceltime, false);
1582 : : }
1583 : :
1584 : : /*
1585 : : * Submit a cancel request to the given connection, waiting only until
1586 : : * the given time.
1587 : : *
1588 : : * We sleep interruptibly until we receive confirmation that the cancel
1589 : : * request has been accepted, and if it is, return true; if the timeout
1590 : : * lapses without that, or the request fails for whatever reason, return
1591 : : * false.
1592 : : */
1593 : : static bool
768 alvherre@alvh.no-ip. 1594 : 2 : pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime)
1595 : : {
760 1596 : 2 : const char *errormsg = libpqsrv_cancel(conn, endtime);
1597 : :
768 1598 [ - + ]: 2 : if (errormsg != NULL)
768 alvherre@alvh.no-ip. 1599 [ # # ]:UBC 0 : ereport(WARNING,
1600 : : errcode(ERRCODE_CONNECTION_FAILURE),
1601 : : errmsg("could not send cancel request: %s", errormsg));
1602 : :
768 alvherre@alvh.no-ip. 1603 :CBC 2 : return errormsg == NULL;
1604 : : }
1605 : :
1606 : : static bool
498 tgl@sss.pgh.pa.us 1607 : 2 : pgfdw_cancel_query_end(PGconn *conn, TimestampTz endtime,
1608 : : TimestampTz retrycanceltime, bool consume_input)
1609 : : {
1610 : : PGresult *result;
1611 : : bool timed_out;
1612 : :
1613 : : /*
1614 : : * If requested, consume whatever data is available from the socket. (Note
1615 : : * that if all data is available, this allows pgfdw_get_cleanup_result to
1616 : : * call PQgetResult without forcing the overhead of WaitLatchOrSocket,
1617 : : * which would be large compared to the overhead of PQconsumeInput.)
1618 : : */
1125 efujita@postgresql.o 1619 [ - + - - ]: 2 : if (consume_input && !PQconsumeInput(conn))
1620 : : {
1125 efujita@postgresql.o 1621 [ # # ]:UBC 0 : ereport(WARNING,
1622 : : (errcode(ERRCODE_CONNECTION_FAILURE),
1623 : : errmsg("could not get result of cancel request: %s",
1624 : : pchomp(PQerrorMessage(conn)))));
1625 : 0 : return false;
1626 : : }
1627 : :
1628 : : /* Get and discard the result of the query. */
498 tgl@sss.pgh.pa.us 1629 [ - + ]:CBC 2 : if (pgfdw_get_cleanup_result(conn, endtime, retrycanceltime,
1630 : : &result, &timed_out))
1631 : : {
1609 fujii@postgresql.org 1632 [ # # ]:UBC 0 : if (timed_out)
1633 [ # # ]: 0 : ereport(WARNING,
1634 : : (errmsg("could not get result of cancel request due to timeout")));
1635 : : else
1636 [ # # ]: 0 : ereport(WARNING,
1637 : : (errcode(ERRCODE_CONNECTION_FAILURE),
1638 : : errmsg("could not get result of cancel request: %s",
1639 : : pchomp(PQerrorMessage(conn)))));
1640 : :
3254 rhaas@postgresql.org 1641 : 0 : return false;
1642 : : }
3254 rhaas@postgresql.org 1643 :CBC 2 : PQclear(result);
1644 : :
1645 : 2 : return true;
1646 : : }
1647 : :
1648 : : /*
1649 : : * Submit a query during (sub)abort cleanup and wait up to 30 seconds for the
1650 : : * result. If the query is executed without error, the return value is true.
1651 : : * If the query is executed successfully but returns an error, the return
1652 : : * value is true if and only if ignore_errors is set. If the query can't be
1653 : : * sent or times out, the return value is false.
1654 : : *
1655 : : * It's not a huge problem if we throw an ERROR here, but if we get into error
1656 : : * recursion trouble, we'll end up slamming the connection shut, which will
1657 : : * necessitate failing the entire toplevel transaction even if subtransactions
1658 : : * were used. Try to use WARNING where we can.
1659 : : */
1660 : : static bool
1661 : 85 : pgfdw_exec_cleanup_query(PGconn *conn, const char *query, bool ignore_errors)
1662 : : {
1663 : : TimestampTz endtime;
1664 : :
1665 : : /*
1666 : : * If it takes too long to execute a cleanup query, assume the connection
1667 : : * is dead. It's fairly likely that this is why we aborted in the first
1668 : : * place (e.g. statement timeout, user cancel), so the timeout shouldn't
1669 : : * be too long.
1670 : : */
1125 efujita@postgresql.o 1671 : 85 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
1672 : : CONNECTION_CLEANUP_TIMEOUT);
1673 : :
1674 [ - + ]: 85 : if (!pgfdw_exec_cleanup_query_begin(conn, query))
1125 efujita@postgresql.o 1675 :UBC 0 : return false;
1125 efujita@postgresql.o 1676 :CBC 85 : return pgfdw_exec_cleanup_query_end(conn, query, endtime,
1677 : : false, ignore_errors);
1678 : : }
1679 : :
1680 : : static bool
1681 : 97 : pgfdw_exec_cleanup_query_begin(PGconn *conn, const char *query)
1682 : : {
761 1683 [ - + ]: 97 : Assert(query != NULL);
1684 : :
1685 : : /*
1686 : : * Submit a query. Since we don't use non-blocking mode, this also can
1687 : : * block. But its risk is relatively small, so we ignore that for now.
1688 : : */
3254 rhaas@postgresql.org 1689 [ - + ]: 97 : if (!PQsendQuery(conn, query))
1690 : : {
280 tgl@sss.pgh.pa.us 1691 :UNC 0 : pgfdw_report(WARNING, NULL, conn, query);
3254 rhaas@postgresql.org 1692 :UBC 0 : return false;
1693 : : }
1694 : :
1125 efujita@postgresql.o 1695 :CBC 97 : return true;
1696 : : }
1697 : :
1698 : : static bool
1699 : 97 : pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query,
1700 : : TimestampTz endtime, bool consume_input,
1701 : : bool ignore_errors)
1702 : : {
1703 : : PGresult *result;
1704 : : bool timed_out;
1705 : :
761 1706 [ - + ]: 97 : Assert(query != NULL);
1707 : :
1708 : : /*
1709 : : * If requested, consume whatever data is available from the socket. (Note
1710 : : * that if all data is available, this allows pgfdw_get_cleanup_result to
1711 : : * call PQgetResult without forcing the overhead of WaitLatchOrSocket,
1712 : : * which would be large compared to the overhead of PQconsumeInput.)
1713 : : */
1125 1714 [ + + - + ]: 97 : if (consume_input && !PQconsumeInput(conn))
1715 : : {
280 tgl@sss.pgh.pa.us 1716 :UNC 0 : pgfdw_report(WARNING, NULL, conn, query);
1125 efujita@postgresql.o 1717 :UBC 0 : return false;
1718 : : }
1719 : :
1720 : : /* Get the result of the query. */
498 tgl@sss.pgh.pa.us 1721 [ - + ]:CBC 97 : if (pgfdw_get_cleanup_result(conn, endtime, endtime, &result, &timed_out))
1722 : : {
1609 fujii@postgresql.org 1723 [ # # ]:UBC 0 : if (timed_out)
1724 [ # # ]: 0 : ereport(WARNING,
1725 : : (errmsg("could not get query result due to timeout"),
1726 : : errcontext("remote SQL command: %s", query)));
1727 : : else
280 tgl@sss.pgh.pa.us 1728 :UNC 0 : pgfdw_report(WARNING, NULL, conn, query);
1729 : :
3254 rhaas@postgresql.org 1730 :UBC 0 : return false;
1731 : : }
1732 : :
1733 : : /* Issue a warning if not successful. */
3254 rhaas@postgresql.org 1734 [ - + ]:CBC 97 : if (PQresultStatus(result) != PGRES_COMMAND_OK)
1735 : : {
280 tgl@sss.pgh.pa.us 1736 :UNC 0 : pgfdw_report(WARNING, result, conn, query);
3254 rhaas@postgresql.org 1737 :UBC 0 : return ignore_errors;
1738 : : }
3246 tgl@sss.pgh.pa.us 1739 :CBC 97 : PQclear(result);
1740 : :
3254 rhaas@postgresql.org 1741 : 97 : return true;
1742 : : }
1743 : :
1744 : : /*
1745 : : * Get, during abort cleanup, the result of a query that is in progress.
1746 : : * This might be a query that is being interrupted by a cancel request or by
1747 : : * transaction abort, or it might be a query that was initiated as part of
1748 : : * transaction abort to get the remote side back to the appropriate state.
1749 : : *
1750 : : * endtime is the time at which we should give up and assume the remote side
1751 : : * is dead. retrycanceltime is the time at which we should issue a fresh
1752 : : * cancel request (pass the same value as endtime if this is not wanted).
1753 : : *
1754 : : * Returns true if the timeout expired or connection trouble occurred,
1755 : : * false otherwise. Sets *result except in case of a true result.
1756 : : * Sets *timed_out to true only when the timeout expired.
1757 : : */
1758 : : static bool
498 tgl@sss.pgh.pa.us 1759 : 99 : pgfdw_get_cleanup_result(PGconn *conn, TimestampTz endtime,
1760 : : TimestampTz retrycanceltime,
1761 : : PGresult **result,
1762 : : bool *timed_out)
1763 : : {
284 tgl@sss.pgh.pa.us 1764 :GNC 99 : bool failed = false;
1765 : 99 : PGresult *last_res = NULL;
1766 : 99 : int canceldelta = RETRY_CANCEL_TIMEOUT * 2;
1767 : :
498 tgl@sss.pgh.pa.us 1768 :CBC 99 : *result = NULL;
1609 fujii@postgresql.org 1769 : 99 : *timed_out = false;
1770 : : for (;;)
284 tgl@sss.pgh.pa.us 1771 :GIC 111 : {
1772 : : PGresult *res;
1773 : :
284 tgl@sss.pgh.pa.us 1774 [ + + ]:GNC 304 : while (PQisBusy(conn))
3254 rhaas@postgresql.org 1775 :ECB (96) : {
1776 : : int wc;
284 tgl@sss.pgh.pa.us 1777 :GNC 94 : TimestampTz now = GetCurrentTimestamp();
1778 : : long cur_timeout;
1779 : :
1780 : : /* If timeout has expired, give up. */
1781 [ - + ]: 94 : if (now >= endtime)
1782 : : {
284 tgl@sss.pgh.pa.us 1783 :UNC 0 : *timed_out = true;
1784 : 0 : failed = true;
1785 : 0 : goto exit;
1786 : : }
1787 : :
1788 : : /* If we need to re-issue the cancel request, do that. */
284 tgl@sss.pgh.pa.us 1789 [ - + ]:GNC 94 : if (now >= retrycanceltime)
1790 : : {
1791 : : /* We ignore failure to issue the repeated request. */
284 tgl@sss.pgh.pa.us 1792 :UNC 0 : (void) libpqsrv_cancel(conn, endtime);
1793 : :
1794 : : /* Recompute "now" in case that took measurable time. */
1795 : 0 : now = GetCurrentTimestamp();
1796 : :
1797 : : /* Adjust re-cancel timeout in increasing steps. */
1798 : 0 : retrycanceltime = TimestampTzPlusMilliseconds(now,
1799 : : canceldelta);
1800 : 0 : canceldelta += canceldelta;
1801 : : }
1802 : :
1803 : : /* If timeout has expired, give up, else get sleep time. */
284 tgl@sss.pgh.pa.us 1804 :GNC 94 : cur_timeout = TimestampDifferenceMilliseconds(now,
1805 : : Min(endtime,
1806 : : retrycanceltime));
1807 [ - + ]: 94 : if (cur_timeout <= 0)
1808 : : {
284 tgl@sss.pgh.pa.us 1809 :UNC 0 : *timed_out = true;
1810 : 0 : failed = true;
1811 : 0 : goto exit;
1812 : : }
1813 : :
1814 : : /* first time, allocate or get the custom wait event */
284 tgl@sss.pgh.pa.us 1815 [ + + ]:GNC 94 : if (pgfdw_we_cleanup_result == 0)
1816 : 2 : pgfdw_we_cleanup_result = WaitEventExtensionNew("PostgresFdwCleanupResult");
1817 : :
1818 : : /* Sleep until there's something to do */
1819 : 94 : wc = WaitLatchOrSocket(MyLatch,
1820 : : WL_LATCH_SET | WL_SOCKET_READABLE |
1821 : : WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
1822 : : PQsocket(conn),
1823 : : cur_timeout, pgfdw_we_cleanup_result);
1824 : 94 : ResetLatch(MyLatch);
1825 : :
1826 [ - + ]: 94 : CHECK_FOR_INTERRUPTS();
1827 : :
1828 : : /* Data available in socket? */
1829 [ + - ]: 94 : if (wc & WL_SOCKET_READABLE)
1830 : : {
1831 [ - + ]: 94 : if (!PQconsumeInput(conn))
1832 : : {
1833 : : /* connection trouble */
284 tgl@sss.pgh.pa.us 1834 :UNC 0 : failed = true;
1835 : 0 : goto exit;
1836 : : }
1837 : : }
1838 : : }
1839 : :
284 tgl@sss.pgh.pa.us 1840 :GNC 210 : res = PQgetResult(conn);
1841 [ + + ]: 210 : if (res == NULL)
1842 : 99 : break; /* query is complete */
1843 : :
284 tgl@sss.pgh.pa.us 1844 :GBC 111 : PQclear(last_res);
284 tgl@sss.pgh.pa.us 1845 :GNC 111 : last_res = res;
1846 : : }
1847 : 99 : exit:
1609 fujii@postgresql.org 1848 [ - + ]:CBC 99 : if (failed)
3246 tgl@sss.pgh.pa.us 1849 :UBC 0 : PQclear(last_res);
1850 : : else
3246 tgl@sss.pgh.pa.us 1851 :CBC 99 : *result = last_res;
1609 fujii@postgresql.org 1852 : 99 : return failed;
1853 : : }
1854 : :
1855 : : /*
1856 : : * Abort remote transaction or subtransaction.
1857 : : *
1858 : : * "toplevel" should be set to true if toplevel (main) transaction is
1859 : : * rollbacked, false otherwise.
1860 : : *
1861 : : * Set entry->changing_xact_state to false on success, true on failure.
1862 : : */
1863 : : static void
1502 efujita@postgresql.o 1864 : 61 : pgfdw_abort_cleanup(ConnCacheEntry *entry, bool toplevel)
1865 : : {
1866 : : char sql[100];
1867 : :
1868 : : /*
1869 : : * Don't try to clean up the connection if we're already in error
1870 : : * recursion trouble.
1871 : : */
1686 fujii@postgresql.org 1872 [ - + ]: 61 : if (in_error_recursion_trouble())
1686 fujii@postgresql.org 1873 :UBC 0 : entry->changing_xact_state = true;
1874 : :
1875 : : /*
1876 : : * If connection is already unsalvageable, don't touch it further.
1877 : : */
1686 fujii@postgresql.org 1878 [ + + ]:CBC 61 : if (entry->changing_xact_state)
1879 : 1 : return;
1880 : :
1881 : : /*
1882 : : * Mark this connection as in the process of changing transaction state.
1883 : : */
1884 : 60 : entry->changing_xact_state = true;
1885 : :
1886 : : /* Assume we might have lost track of prepared statements */
1887 : 60 : entry->have_error = true;
1888 : :
1889 : : /*
1890 : : * If a command has been submitted to the remote server by using an
1891 : : * asynchronous execution function, the command might not have yet
1892 : : * completed. Check to see if a command is still being processed by the
1893 : : * remote server, and if so, request cancellation of the command.
1894 : : */
1895 [ + + ]: 60 : if (PQtransactionStatus(entry->conn) == PQTRANS_ACTIVE &&
1896 [ - + ]: 2 : !pgfdw_cancel_query(entry->conn))
1686 fujii@postgresql.org 1897 :UBC 0 : return; /* Unable to cancel running query */
1898 : :
1125 efujita@postgresql.o 1899 [ + + ]:CBC 60 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
1686 fujii@postgresql.org 1900 [ - + ]: 60 : if (!pgfdw_exec_cleanup_query(entry->conn, sql, false))
1502 efujita@postgresql.o 1901 :UBC 0 : return; /* Unable to abort remote (sub)transaction */
1902 : :
1686 fujii@postgresql.org 1903 [ + + ]:CBC 60 : if (toplevel)
1904 : : {
1905 [ + + + - ]: 52 : if (entry->have_prep_stmt && entry->have_error &&
1906 [ - + ]: 25 : !pgfdw_exec_cleanup_query(entry->conn,
1907 : : "DEALLOCATE ALL",
1908 : : true))
1686 fujii@postgresql.org 1909 :UBC 0 : return; /* Trouble clearing prepared statements */
1910 : :
1686 fujii@postgresql.org 1911 :CBC 52 : entry->have_prep_stmt = false;
1912 : 52 : entry->have_error = false;
1913 : : }
1914 : :
1915 : : /*
1916 : : * If pendingAreq of the per-connection state is not NULL, it means that
1917 : : * an asynchronous fetch begun by fetch_more_data_begin() was not done
1918 : : * successfully and thus the per-connection state was not reset in
1919 : : * fetch_more_data(); in that case reset the per-connection state here.
1920 : : */
1565 efujita@postgresql.o 1921 [ + + ]: 60 : if (entry->state.pendingAreq)
1922 : 1 : memset(&entry->state, 0, sizeof(entry->state));
1923 : :
1924 : : /* Disarm changing_xact_state if it all worked */
1686 fujii@postgresql.org 1925 : 60 : entry->changing_xact_state = false;
1926 : : }
1927 : :
1928 : : /*
1929 : : * Like pgfdw_abort_cleanup, submit an abort command or cancel request, but
1930 : : * don't wait for the result.
1931 : : *
1932 : : * Returns true if the abort command or cancel request is successfully issued,
1933 : : * false otherwise. If the abort command is successfully issued, the given
1934 : : * connection cache entry is appended to *pending_entries. Otherwise, if the
1935 : : * cancel request is successfully issued, it is appended to *cancel_requested.
1936 : : */
1937 : : static bool
1125 efujita@postgresql.o 1938 : 8 : pgfdw_abort_cleanup_begin(ConnCacheEntry *entry, bool toplevel,
1939 : : List **pending_entries, List **cancel_requested)
1940 : : {
1941 : : /*
1942 : : * Don't try to clean up the connection if we're already in error
1943 : : * recursion trouble.
1944 : : */
1945 [ - + ]: 8 : if (in_error_recursion_trouble())
1125 efujita@postgresql.o 1946 :UBC 0 : entry->changing_xact_state = true;
1947 : :
1948 : : /*
1949 : : * If connection is already unsalvageable, don't touch it further.
1950 : : */
1125 efujita@postgresql.o 1951 [ - + ]:CBC 8 : if (entry->changing_xact_state)
1125 efujita@postgresql.o 1952 :UBC 0 : return false;
1953 : :
1954 : : /*
1955 : : * Mark this connection as in the process of changing transaction state.
1956 : : */
1125 efujita@postgresql.o 1957 :CBC 8 : entry->changing_xact_state = true;
1958 : :
1959 : : /* Assume we might have lost track of prepared statements */
1960 : 8 : entry->have_error = true;
1961 : :
1962 : : /*
1963 : : * If a command has been submitted to the remote server by using an
1964 : : * asynchronous execution function, the command might not have yet
1965 : : * completed. Check to see if a command is still being processed by the
1966 : : * remote server, and if so, request cancellation of the command.
1967 : : */
1968 [ - + ]: 8 : if (PQtransactionStatus(entry->conn) == PQTRANS_ACTIVE)
1969 : : {
1970 : : TimestampTz endtime;
1971 : :
768 alvherre@alvh.no-ip. 1972 :UBC 0 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
1973 : : CONNECTION_CLEANUP_TIMEOUT);
1974 [ # # ]: 0 : if (!pgfdw_cancel_query_begin(entry->conn, endtime))
1125 efujita@postgresql.o 1975 : 0 : return false; /* Unable to cancel running query */
1976 : 0 : *cancel_requested = lappend(*cancel_requested, entry);
1977 : : }
1978 : : else
1979 : : {
1980 : : char sql[100];
1981 : :
1125 efujita@postgresql.o 1982 [ + + ]:CBC 8 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
1983 [ - + ]: 8 : if (!pgfdw_exec_cleanup_query_begin(entry->conn, sql))
1125 efujita@postgresql.o 1984 :UBC 0 : return false; /* Unable to abort remote transaction */
1125 efujita@postgresql.o 1985 :CBC 8 : *pending_entries = lappend(*pending_entries, entry);
1986 : : }
1987 : :
1988 : 8 : return true;
1989 : : }
1990 : :
1991 : : /*
1992 : : * Finish pre-commit cleanup of connections on each of which we've sent a
1993 : : * COMMIT command to the remote server.
1994 : : */
1995 : : static void
1531 1996 : 13 : pgfdw_finish_pre_commit_cleanup(List *pending_entries)
1997 : : {
1998 : : ConnCacheEntry *entry;
1999 : 13 : List *pending_deallocs = NIL;
2000 : : ListCell *lc;
2001 : :
2002 [ - + ]: 13 : Assert(pending_entries);
2003 : :
2004 : : /*
2005 : : * Get the result of the COMMIT command for each of the pending entries
2006 : : */
2007 [ + - + + : 29 : foreach(lc, pending_entries)
+ + ]
2008 : : {
2009 : 16 : entry = (ConnCacheEntry *) lfirst(lc);
2010 : :
2011 [ - + ]: 16 : Assert(entry->changing_xact_state);
2012 : :
2013 : : /*
2014 : : * We might already have received the result on the socket, so pass
2015 : : * consume_input=true to try to consume it first
2016 : : */
2017 : 16 : do_sql_command_end(entry->conn, "COMMIT TRANSACTION", true);
2018 : 16 : entry->changing_xact_state = false;
2019 : :
2020 : : /* Do a DEALLOCATE ALL in parallel if needed */
2021 [ + + + + ]: 16 : if (entry->have_prep_stmt && entry->have_error)
2022 : : {
2023 : : /* Ignore errors (see notes in pgfdw_xact_callback) */
2024 [ + - ]: 2 : if (PQsendQuery(entry->conn, "DEALLOCATE ALL"))
2025 : : {
2026 : 2 : pending_deallocs = lappend(pending_deallocs, entry);
2027 : 2 : continue;
2028 : : }
2029 : : }
2030 : 14 : entry->have_prep_stmt = false;
2031 : 14 : entry->have_error = false;
2032 : :
2033 : 14 : pgfdw_reset_xact_state(entry, true);
2034 : : }
2035 : :
2036 : : /* No further work if no pending entries */
2037 [ + + ]: 13 : if (!pending_deallocs)
2038 : 12 : return;
2039 : :
2040 : : /*
2041 : : * Get the result of the DEALLOCATE command for each of the pending
2042 : : * entries
2043 : : */
2044 [ + - + + : 3 : foreach(lc, pending_deallocs)
+ + ]
2045 : : {
2046 : : PGresult *res;
2047 : :
2048 : 2 : entry = (ConnCacheEntry *) lfirst(lc);
2049 : :
2050 : : /* Ignore errors (see notes in pgfdw_xact_callback) */
2051 [ + + ]: 4 : while ((res = PQgetResult(entry->conn)) != NULL)
2052 : : {
2053 : 2 : PQclear(res);
2054 : : /* Stop if the connection is lost (else we'll loop infinitely) */
2055 [ - + ]: 2 : if (PQstatus(entry->conn) == CONNECTION_BAD)
1531 efujita@postgresql.o 2056 :UBC 0 : break;
2057 : : }
1531 efujita@postgresql.o 2058 :CBC 2 : entry->have_prep_stmt = false;
2059 : 2 : entry->have_error = false;
2060 : :
2061 : 2 : pgfdw_reset_xact_state(entry, true);
2062 : : }
2063 : : }
2064 : :
2065 : : /*
2066 : : * Finish pre-subcommit cleanup of connections on each of which we've sent a
2067 : : * RELEASE command to the remote server.
2068 : : */
2069 : : static void
2070 : 1 : pgfdw_finish_pre_subcommit_cleanup(List *pending_entries, int curlevel)
2071 : : {
2072 : : ConnCacheEntry *entry;
2073 : : char sql[100];
2074 : : ListCell *lc;
2075 : :
2076 [ - + ]: 1 : Assert(pending_entries);
2077 : :
2078 : : /*
2079 : : * Get the result of the RELEASE command for each of the pending entries
2080 : : */
2081 : 1 : snprintf(sql, sizeof(sql), "RELEASE SAVEPOINT s%d", curlevel);
2082 [ + - + + : 3 : foreach(lc, pending_entries)
+ + ]
2083 : : {
2084 : 2 : entry = (ConnCacheEntry *) lfirst(lc);
2085 : :
2086 [ - + ]: 2 : Assert(entry->changing_xact_state);
2087 : :
2088 : : /*
2089 : : * We might already have received the result on the socket, so pass
2090 : : * consume_input=true to try to consume it first
2091 : : */
2092 : 2 : do_sql_command_end(entry->conn, sql, true);
2093 : 2 : entry->changing_xact_state = false;
2094 : :
2095 : 2 : pgfdw_reset_xact_state(entry, false);
2096 : : }
2097 : 1 : }
2098 : :
2099 : : /*
2100 : : * Finish abort cleanup of connections on each of which we've sent an abort
2101 : : * command or cancel request to the remote server.
2102 : : */
2103 : : static void
1125 2104 : 4 : pgfdw_finish_abort_cleanup(List *pending_entries, List *cancel_requested,
2105 : : bool toplevel)
2106 : : {
2107 : 4 : List *pending_deallocs = NIL;
2108 : : ListCell *lc;
2109 : :
2110 : : /*
2111 : : * For each of the pending cancel requests (if any), get and discard the
2112 : : * result of the query, and submit an abort command to the remote server.
2113 : : */
2114 [ - + ]: 4 : if (cancel_requested)
2115 : : {
1125 efujita@postgresql.o 2116 [ # # # # :UBC 0 : foreach(lc, cancel_requested)
# # ]
2117 : : {
2118 : 0 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
498 tgl@sss.pgh.pa.us 2119 : 0 : TimestampTz now = GetCurrentTimestamp();
2120 : : TimestampTz endtime;
2121 : : TimestampTz retrycanceltime;
2122 : : char sql[100];
2123 : :
1125 efujita@postgresql.o 2124 [ # # ]: 0 : Assert(entry->changing_xact_state);
2125 : :
2126 : : /*
2127 : : * Set end time. You might think we should do this before issuing
2128 : : * cancel request like in normal mode, but that is problematic,
2129 : : * because if, for example, it took longer than 30 seconds to
2130 : : * process the first few entries in the cancel_requested list, it
2131 : : * would cause a timeout error when processing each of the
2132 : : * remaining entries in the list, leading to slamming that entry's
2133 : : * connection shut.
2134 : : */
498 tgl@sss.pgh.pa.us 2135 : 0 : endtime = TimestampTzPlusMilliseconds(now,
2136 : : CONNECTION_CLEANUP_TIMEOUT);
2137 : 0 : retrycanceltime = TimestampTzPlusMilliseconds(now,
2138 : : RETRY_CANCEL_TIMEOUT);
2139 : :
2140 [ # # ]: 0 : if (!pgfdw_cancel_query_end(entry->conn, endtime,
2141 : : retrycanceltime, true))
2142 : : {
2143 : : /* Unable to cancel running query */
1125 efujita@postgresql.o 2144 : 0 : pgfdw_reset_xact_state(entry, toplevel);
2145 : 0 : continue;
2146 : : }
2147 : :
2148 : : /* Send an abort command in parallel if needed */
2149 [ # # ]: 0 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
2150 [ # # ]: 0 : if (!pgfdw_exec_cleanup_query_begin(entry->conn, sql))
2151 : : {
2152 : : /* Unable to abort remote (sub)transaction */
2153 : 0 : pgfdw_reset_xact_state(entry, toplevel);
2154 : : }
2155 : : else
2156 : 0 : pending_entries = lappend(pending_entries, entry);
2157 : : }
2158 : : }
2159 : :
2160 : : /* No further work if no pending entries */
1125 efujita@postgresql.o 2161 [ - + ]:CBC 4 : if (!pending_entries)
1125 efujita@postgresql.o 2162 :UBC 0 : return;
2163 : :
2164 : : /*
2165 : : * Get the result of the abort command for each of the pending entries
2166 : : */
1125 efujita@postgresql.o 2167 [ + - + + :CBC 12 : foreach(lc, pending_entries)
+ + ]
2168 : : {
2169 : 8 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
2170 : : TimestampTz endtime;
2171 : : char sql[100];
2172 : :
2173 [ - + ]: 8 : Assert(entry->changing_xact_state);
2174 : :
2175 : : /*
2176 : : * Set end time. We do this now, not before issuing the command like
2177 : : * in normal mode, for the same reason as for the cancel_requested
2178 : : * entries.
2179 : : */
2180 : 8 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
2181 : : CONNECTION_CLEANUP_TIMEOUT);
2182 : :
2183 [ + + ]: 8 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
2184 [ - + ]: 8 : if (!pgfdw_exec_cleanup_query_end(entry->conn, sql, endtime,
2185 : : true, false))
2186 : : {
2187 : : /* Unable to abort remote (sub)transaction */
1125 efujita@postgresql.o 2188 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
1125 efujita@postgresql.o 2189 :CBC 4 : continue;
2190 : : }
2191 : :
2192 [ + + ]: 8 : if (toplevel)
2193 : : {
2194 : : /* Do a DEALLOCATE ALL in parallel if needed */
2195 [ + - + - ]: 4 : if (entry->have_prep_stmt && entry->have_error)
2196 : : {
2197 [ - + ]: 4 : if (!pgfdw_exec_cleanup_query_begin(entry->conn,
2198 : : "DEALLOCATE ALL"))
2199 : : {
2200 : : /* Trouble clearing prepared statements */
1125 efujita@postgresql.o 2201 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
2202 : : }
2203 : : else
1125 efujita@postgresql.o 2204 :CBC 4 : pending_deallocs = lappend(pending_deallocs, entry);
2205 : 4 : continue;
2206 : : }
1125 efujita@postgresql.o 2207 :UBC 0 : entry->have_prep_stmt = false;
2208 : 0 : entry->have_error = false;
2209 : : }
2210 : :
2211 : : /* Reset the per-connection state if needed */
1125 efujita@postgresql.o 2212 [ - + ]:CBC 4 : if (entry->state.pendingAreq)
1125 efujita@postgresql.o 2213 :UBC 0 : memset(&entry->state, 0, sizeof(entry->state));
2214 : :
2215 : : /* We're done with this entry; unset the changing_xact_state flag */
1125 efujita@postgresql.o 2216 :CBC 4 : entry->changing_xact_state = false;
2217 : 4 : pgfdw_reset_xact_state(entry, toplevel);
2218 : : }
2219 : :
2220 : : /* No further work if no pending entries */
2221 [ + + ]: 4 : if (!pending_deallocs)
2222 : 2 : return;
2223 [ - + ]: 2 : Assert(toplevel);
2224 : :
2225 : : /*
2226 : : * Get the result of the DEALLOCATE command for each of the pending
2227 : : * entries
2228 : : */
2229 [ + - + + : 6 : foreach(lc, pending_deallocs)
+ + ]
2230 : : {
2231 : 4 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
2232 : : TimestampTz endtime;
2233 : :
2234 [ - + ]: 4 : Assert(entry->changing_xact_state);
2235 [ - + ]: 4 : Assert(entry->have_prep_stmt);
2236 [ - + ]: 4 : Assert(entry->have_error);
2237 : :
2238 : : /*
2239 : : * Set end time. We do this now, not before issuing the command like
2240 : : * in normal mode, for the same reason as for the cancel_requested
2241 : : * entries.
2242 : : */
2243 : 4 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
2244 : : CONNECTION_CLEANUP_TIMEOUT);
2245 : :
2246 [ - + ]: 4 : if (!pgfdw_exec_cleanup_query_end(entry->conn, "DEALLOCATE ALL",
2247 : : endtime, true, true))
2248 : : {
2249 : : /* Trouble clearing prepared statements */
1125 efujita@postgresql.o 2250 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
2251 : 0 : continue;
2252 : : }
1125 efujita@postgresql.o 2253 :CBC 4 : entry->have_prep_stmt = false;
2254 : 4 : entry->have_error = false;
2255 : :
2256 : : /* Reset the per-connection state if needed */
2257 [ - + ]: 4 : if (entry->state.pendingAreq)
1125 efujita@postgresql.o 2258 :UBC 0 : memset(&entry->state, 0, sizeof(entry->state));
2259 : :
2260 : : /* We're done with this entry; unset the changing_xact_state flag */
1125 efujita@postgresql.o 2261 :CBC 4 : entry->changing_xact_state = false;
2262 : 4 : pgfdw_reset_xact_state(entry, toplevel);
2263 : : }
2264 : : }
2265 : :
2266 : : /* Number of output arguments (columns) for various API versions */
2267 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_1 2
2268 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_2 6
2269 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS 6 /* maximum of above */
2270 : :
2271 : : /*
2272 : : * Internal function used by postgres_fdw_get_connections variants.
2273 : : *
2274 : : * For API version 1.1, this function takes no input parameter and
2275 : : * returns a set of records with the following values:
2276 : : *
2277 : : * - server_name - server name of active connection. In case the foreign server
2278 : : * is dropped but still the connection is active, then the server name will
2279 : : * be NULL in output.
2280 : : * - valid - true/false representing whether the connection is valid or not.
2281 : : * Note that connections can become invalid in pgfdw_inval_callback.
2282 : : *
2283 : : * For API version 1.2 and later, this function takes an input parameter
2284 : : * to check a connection status and returns the following
2285 : : * additional values along with the four values from version 1.1:
2286 : : *
2287 : : * - user_name - the local user name of the active connection. In case the
2288 : : * user mapping is dropped but the connection is still active, then the
2289 : : * user name will be NULL in the output.
2290 : : * - used_in_xact - true if the connection is used in the current transaction.
2291 : : * - closed - true if the connection is closed.
2292 : : * - remote_backend_pid - process ID of the remote backend, on the foreign
2293 : : * server, handling the connection.
2294 : : *
2295 : : * No records are returned when there are no cached connections at all.
2296 : : */
2297 : : static void
648 fujii@postgresql.org 2298 : 13 : postgres_fdw_get_connections_internal(FunctionCallInfo fcinfo,
2299 : : enum pgfdwVersion api_version)
2300 : : {
1933 2301 : 13 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
2302 : : HASH_SEQ_STATUS scan;
2303 : : ConnCacheEntry *entry;
2304 : :
1295 michael@paquier.xyz 2305 : 13 : InitMaterializedSRF(fcinfo, 0);
2306 : :
2307 : : /* If cache doesn't exist, we return no records */
1933 fujii@postgresql.org 2308 [ - + ]: 13 : if (!ConnectionHash)
648 fujii@postgresql.org 2309 :UBC 0 : return;
2310 : :
2311 : : /* Check we have the expected number of output arguments */
648 fujii@postgresql.org 2312 [ - + - ]:CBC 13 : switch (rsinfo->setDesc->natts)
2313 : : {
648 fujii@postgresql.org 2314 :UBC 0 : case POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_1:
2315 [ # # ]: 0 : if (api_version != PGFDW_V1_1)
2316 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
2317 : 0 : break;
648 fujii@postgresql.org 2318 :CBC 13 : case POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_2:
2319 [ - + ]: 13 : if (api_version != PGFDW_V1_2)
648 fujii@postgresql.org 2320 [ # # ]:UBC 0 : elog(ERROR, "incorrect number of output arguments");
648 fujii@postgresql.org 2321 :CBC 13 : break;
648 fujii@postgresql.org 2322 :UBC 0 : default:
2323 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
2324 : : }
2325 : :
1933 fujii@postgresql.org 2326 :CBC 13 : hash_seq_init(&scan, ConnectionHash);
2327 [ + + ]: 113 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
2328 : : {
2329 : : ForeignServer *server;
1389 peter@eisentraut.org 2330 : 100 : Datum values[POSTGRES_FDW_GET_CONNECTIONS_COLS] = {0};
2331 : 100 : bool nulls[POSTGRES_FDW_GET_CONNECTIONS_COLS] = {0};
594 fujii@postgresql.org 2332 : 100 : int i = 0;
2333 : :
2334 : : /* We only look for open remote connections */
1933 2335 [ + + ]: 100 : if (!entry->conn)
2336 : 87 : continue;
2337 : :
2338 : 13 : server = GetForeignServerExtended(entry->serverid, FSV_MISSING_OK);
2339 : :
2340 : : /*
2341 : : * The foreign server may have been dropped in current explicit
2342 : : * transaction. It is not possible to drop the server from another
2343 : : * session when the connection associated with it is in use in the
2344 : : * current transaction, if tried so, the drop query in another session
2345 : : * blocks until the current transaction finishes.
2346 : : *
2347 : : * Even though the server is dropped in the current transaction, the
2348 : : * cache can still have associated active connection entry, say we
2349 : : * call such connections dangling. Since we can not fetch the server
2350 : : * name from system catalogs for dangling connections, instead we show
2351 : : * NULL value for server name in output.
2352 : : *
2353 : : * We could have done better by storing the server name in the cache
2354 : : * entry instead of server oid so that it could be used in the output.
2355 : : * But the server name in each cache entry requires 64 bytes of
2356 : : * memory, which is huge, when there are many cached connections and
2357 : : * the use case i.e. dropping the foreign server within the explicit
2358 : : * current transaction seems rare. So, we chose to show NULL value for
2359 : : * server name in output.
2360 : : *
2361 : : * Such dangling connections get closed either in next use or at the
2362 : : * end of current explicit transaction in pgfdw_xact_callback.
2363 : : */
2364 [ + + ]: 13 : if (!server)
2365 : : {
2366 : : /*
2367 : : * If the server has been dropped in the current explicit
2368 : : * transaction, then this entry would have been invalidated in
2369 : : * pgfdw_inval_callback at the end of drop server command. Note
2370 : : * that this connection would not have been closed in
2371 : : * pgfdw_inval_callback because it is still being used in the
2372 : : * current explicit transaction. So, assert that here.
2373 : : */
2374 [ + - + - : 1 : Assert(entry->conn && entry->xact_depth > 0 && entry->invalidated);
- + ]
2375 : :
2376 : : /* Show null, if no server name was found */
594 2377 : 1 : nulls[i++] = true;
2378 : : }
2379 : : else
2380 : 12 : values[i++] = CStringGetTextDatum(server->servername);
2381 : :
2382 [ + - ]: 13 : if (api_version >= PGFDW_V1_2)
2383 : : {
2384 : : HeapTuple tp;
2385 : :
2386 : : /* Use the system cache to obtain the user mapping */
2387 : 13 : tp = SearchSysCache1(USERMAPPINGOID, ObjectIdGetDatum(entry->key));
2388 : :
2389 : : /*
2390 : : * Just like in the foreign server case, user mappings can also be
2391 : : * dropped in the current explicit transaction. Therefore, the
2392 : : * similar check as in the server case is required.
2393 : : */
2394 [ + + ]: 13 : if (!HeapTupleIsValid(tp))
2395 : : {
2396 : : /*
2397 : : * If we reach here, this entry must have been invalidated in
2398 : : * pgfdw_inval_callback, same as in the server case.
2399 : : */
2400 [ + - + - : 1 : Assert(entry->conn && entry->xact_depth > 0 &&
- + ]
2401 : : entry->invalidated);
2402 : :
2403 : 1 : nulls[i++] = true;
2404 : : }
2405 : : else
2406 : : {
2407 : : Oid userid;
2408 : :
2409 : 12 : userid = ((Form_pg_user_mapping) GETSTRUCT(tp))->umuser;
2410 [ + + ]: 12 : values[i++] = CStringGetTextDatum(MappingUserName(userid));
2411 : 12 : ReleaseSysCache(tp);
2412 : : }
2413 : : }
2414 : :
2415 : 13 : values[i++] = BoolGetDatum(!entry->invalidated);
2416 : :
648 2417 [ + - ]: 13 : if (api_version >= PGFDW_V1_2)
2418 : : {
2419 : 13 : bool check_conn = PG_GETARG_BOOL(0);
2420 : :
2421 : : /* Is this connection used in the current transaction? */
594 2422 : 13 : values[i++] = BoolGetDatum(entry->xact_depth > 0);
2423 : :
2424 : : /*
2425 : : * If a connection status check is requested and supported, return
2426 : : * whether the connection is closed. Otherwise, return NULL.
2427 : : */
648 2428 [ + + + - ]: 13 : if (check_conn && pgfdw_conn_checkable())
594 2429 : 2 : values[i++] = BoolGetDatum(pgfdw_conn_check(entry->conn) != 0);
2430 : : else
2431 : 11 : nulls[i++] = true;
2432 : :
2433 : : /* Return process ID of remote backend */
428 2434 : 13 : values[i++] = Int32GetDatum(PQbackendPID(entry->conn));
2435 : : }
2436 : :
1519 michael@paquier.xyz 2437 : 13 : tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
2438 : : }
2439 : : }
2440 : :
2441 : : /*
2442 : : * Values in connection strings must be enclosed in single quotes. Single
2443 : : * quotes and backslashes must be escaped with backslash. NB: these rules are
2444 : : * different from the rules for escaping a SQL literal.
2445 : : */
2446 : : static void
60 jdavis@postgresql.or 2447 :GNC 85 : appendEscapedValue(StringInfo str, const char *val)
2448 : : {
2449 : 85 : appendStringInfoChar(str, '\'');
2450 [ + + ]: 655 : for (int i = 0; val[i] != '\0'; i++)
2451 : : {
2452 [ + - - + ]: 570 : if (val[i] == '\\' || val[i] == '\'')
60 jdavis@postgresql.or 2453 :UNC 0 : appendStringInfoChar(str, '\\');
60 jdavis@postgresql.or 2454 :GNC 570 : appendStringInfoChar(str, val[i]);
2455 : : }
2456 : 85 : appendStringInfoChar(str, '\'');
2457 : 85 : }
2458 : :
2459 : : Datum
2460 : 9 : postgres_fdw_connection(PG_FUNCTION_ARGS)
2461 : : {
2462 : 9 : Oid userid = PG_GETARG_OID(0);
2463 : 9 : Oid serverid = PG_GETARG_OID(1);
2464 : 9 : ForeignServer *server = GetForeignServer(serverid);
2465 : 9 : UserMapping *user = GetUserMapping(userid, serverid);
2466 : : StringInfoData str;
2467 : : const char **keywords;
2468 : : const char **values;
2469 : : char *appname;
2470 : 9 : char *sep = "";
2471 : :
2472 : 9 : construct_connection_params(server, user, &keywords, &values, &appname);
2473 : :
2474 : 9 : initStringInfo(&str);
2475 [ + + ]: 94 : for (int i = 0; keywords[i] != NULL; i++)
2476 : : {
2477 [ - + ]: 85 : if (values[i] == NULL)
60 jdavis@postgresql.or 2478 :UNC 0 : continue;
60 jdavis@postgresql.or 2479 :GNC 85 : appendStringInfo(&str, "%s%s = ", sep, keywords[i]);
2480 : 85 : appendEscapedValue(&str, values[i]);
2481 : 85 : sep = " ";
2482 : : }
2483 : :
2484 [ + + ]: 9 : if (appname != NULL)
2485 : 2 : pfree(appname);
2486 : 9 : pfree(keywords);
2487 : 9 : pfree(values);
2488 : 9 : PG_RETURN_TEXT_P(cstring_to_text(str.data));
2489 : : }
2490 : :
2491 : : /*
2492 : : * List active foreign server connections.
2493 : : *
2494 : : * The SQL API of this function has changed multiple times, and will likely
2495 : : * do so again in future. To support the case where a newer version of this
2496 : : * loadable module is being used with an old SQL declaration of the function,
2497 : : * we continue to support the older API versions.
2498 : : */
2499 : : Datum
648 fujii@postgresql.org 2500 :CBC 13 : postgres_fdw_get_connections_1_2(PG_FUNCTION_ARGS)
2501 : : {
2502 : 13 : postgres_fdw_get_connections_internal(fcinfo, PGFDW_V1_2);
2503 : :
2504 : 13 : PG_RETURN_VOID();
2505 : : }
2506 : :
2507 : : Datum
648 fujii@postgresql.org 2508 :UBC 0 : postgres_fdw_get_connections(PG_FUNCTION_ARGS)
2509 : : {
2510 : 0 : postgres_fdw_get_connections_internal(fcinfo, PGFDW_V1_1);
2511 : :
1933 2512 : 0 : PG_RETURN_VOID();
2513 : : }
2514 : :
2515 : : /*
2516 : : * Disconnect the specified cached connections.
2517 : : *
2518 : : * This function discards the open connections that are established by
2519 : : * postgres_fdw from the local session to the foreign server with
2520 : : * the given name. Note that there can be multiple connections to
2521 : : * the given server using different user mappings. If the connections
2522 : : * are used in the current local transaction, they are not disconnected
2523 : : * and warning messages are reported. This function returns true
2524 : : * if it disconnects at least one connection, otherwise false. If no
2525 : : * foreign server with the given name is found, an error is reported.
2526 : : */
2527 : : Datum
1925 fujii@postgresql.org 2528 :CBC 4 : postgres_fdw_disconnect(PG_FUNCTION_ARGS)
2529 : : {
2530 : : ForeignServer *server;
2531 : : char *servername;
2532 : :
2533 : 4 : servername = text_to_cstring(PG_GETARG_TEXT_PP(0));
2534 : 4 : server = GetForeignServerByName(servername, false);
2535 : :
2536 : 3 : PG_RETURN_BOOL(disconnect_cached_connections(server->serverid));
2537 : : }
2538 : :
2539 : : /*
2540 : : * Disconnect all the cached connections.
2541 : : *
2542 : : * This function discards all the open connections that are established by
2543 : : * postgres_fdw from the local session to the foreign servers.
2544 : : * If the connections are used in the current local transaction, they are
2545 : : * not disconnected and warning messages are reported. This function
2546 : : * returns true if it disconnects at least one connection, otherwise false.
2547 : : */
2548 : : Datum
2549 : 5 : postgres_fdw_disconnect_all(PG_FUNCTION_ARGS)
2550 : : {
2551 : 5 : PG_RETURN_BOOL(disconnect_cached_connections(InvalidOid));
2552 : : }
2553 : :
2554 : : /*
2555 : : * Workhorse to disconnect cached connections.
2556 : : *
2557 : : * This function scans all the connection cache entries and disconnects
2558 : : * the open connections whose foreign server OID matches with
2559 : : * the specified one. If InvalidOid is specified, it disconnects all
2560 : : * the cached connections.
2561 : : *
2562 : : * This function emits a warning for each connection that's used in
2563 : : * the current transaction and doesn't close it. It returns true if
2564 : : * it disconnects at least one connection, otherwise false.
2565 : : *
2566 : : * Note that this function disconnects even the connections that are
2567 : : * established by other users in the same local session using different
2568 : : * user mappings. This leads even non-superuser to be able to close
2569 : : * the connections established by superusers in the same local session.
2570 : : *
2571 : : * XXX As of now we don't see any security risk doing this. But we should
2572 : : * set some restrictions on that, for example, prevent non-superuser
2573 : : * from closing the connections established by superusers even
2574 : : * in the same session?
2575 : : */
2576 : : static bool
2577 : 8 : disconnect_cached_connections(Oid serverid)
2578 : : {
2579 : : HASH_SEQ_STATUS scan;
2580 : : ConnCacheEntry *entry;
2581 : 8 : bool all = !OidIsValid(serverid);
2582 : 8 : bool result = false;
2583 : :
2584 : : /*
2585 : : * Connection cache hashtable has not been initialized yet in this
2586 : : * session, so return false.
2587 : : */
2588 [ - + ]: 8 : if (!ConnectionHash)
1925 fujii@postgresql.org 2589 :UBC 0 : return false;
2590 : :
1925 fujii@postgresql.org 2591 :CBC 8 : hash_seq_init(&scan, ConnectionHash);
2592 [ + + ]: 67 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
2593 : : {
2594 : : /* Ignore cache entry if no open connection right now. */
2595 [ + + ]: 59 : if (!entry->conn)
2596 : 47 : continue;
2597 : :
2598 [ + + + + ]: 12 : if (all || entry->serverid == serverid)
2599 : : {
2600 : : /*
2601 : : * Emit a warning because the connection to close is used in the
2602 : : * current transaction and cannot be disconnected right now.
2603 : : */
2604 [ + + ]: 9 : if (entry->xact_depth > 0)
2605 : : {
2606 : : ForeignServer *server;
2607 : :
2608 : 3 : server = GetForeignServerExtended(entry->serverid,
2609 : : FSV_MISSING_OK);
2610 : :
2611 [ - + ]: 3 : if (!server)
2612 : : {
2613 : : /*
2614 : : * If the foreign server was dropped while its connection
2615 : : * was used in the current transaction, the connection
2616 : : * must have been marked as invalid by
2617 : : * pgfdw_inval_callback at the end of DROP SERVER command.
2618 : : */
1925 fujii@postgresql.org 2619 [ # # ]:UBC 0 : Assert(entry->invalidated);
2620 : :
2621 [ # # ]: 0 : ereport(WARNING,
2622 : : (errmsg("cannot close dropped server connection because it is still in use")));
2623 : : }
2624 : : else
1925 fujii@postgresql.org 2625 [ + - ]:CBC 3 : ereport(WARNING,
2626 : : (errmsg("cannot close connection for server \"%s\" because it is still in use",
2627 : : server->servername)));
2628 : : }
2629 : : else
2630 : : {
2631 [ - + ]: 6 : elog(DEBUG3, "discarding connection %p", entry->conn);
2632 : 6 : disconnect_pg_server(entry);
2633 : 6 : result = true;
2634 : : }
2635 : : }
2636 : : }
2637 : :
2638 : 8 : return result;
2639 : : }
2640 : :
2641 : : /*
2642 : : * Check if the remote server closed the connection.
2643 : : *
2644 : : * Returns 1 if the connection is closed, -1 if an error occurred,
2645 : : * and 0 if it's not closed or if the connection check is unavailable
2646 : : * on this platform.
2647 : : */
2648 : : static int
648 2649 : 2 : pgfdw_conn_check(PGconn *conn)
2650 : : {
2651 : 2 : int sock = PQsocket(conn);
2652 : :
2653 [ + - - + ]: 2 : if (PQstatus(conn) != CONNECTION_OK || sock == -1)
648 fujii@postgresql.org 2654 :UBC 0 : return -1;
2655 : :
2656 : : #if (defined(HAVE_POLL) && defined(POLLRDHUP))
2657 : : {
2658 : : struct pollfd input_fd;
2659 : : int result;
2660 : :
648 fujii@postgresql.org 2661 :CBC 2 : input_fd.fd = sock;
2662 : 2 : input_fd.events = POLLRDHUP;
2663 : 2 : input_fd.revents = 0;
2664 : :
2665 : : do
2666 : 2 : result = poll(&input_fd, 1, 0);
2667 [ - + - - ]: 2 : while (result < 0 && errno == EINTR);
2668 : :
2669 [ - + ]: 2 : if (result < 0)
648 fujii@postgresql.org 2670 :UBC 0 : return -1;
2671 : :
647 fujii@postgresql.org 2672 :CBC 2 : return (input_fd.revents &
2673 : 2 : (POLLRDHUP | POLLHUP | POLLERR | POLLNVAL)) ? 1 : 0;
2674 : : }
2675 : : #else
2676 : : return 0;
2677 : : #endif
2678 : : }
2679 : :
2680 : : /*
2681 : : * Check if connection status checking is available on this platform.
2682 : : *
2683 : : * Returns true if available, false otherwise.
2684 : : */
2685 : : static bool
648 2686 : 2 : pgfdw_conn_checkable(void)
2687 : : {
2688 : : #if (defined(HAVE_POLL) && defined(POLLRDHUP))
2689 : 2 : return true;
2690 : : #else
2691 : : return false;
2692 : : #endif
2693 : : }
2694 : :
2695 : : /*
2696 : : * Ensure that require_auth and SCRAM keys are correctly set on values. SCRAM
2697 : : * keys used to pass-through are coming from the initial connection from the
2698 : : * client with the server.
2699 : : *
2700 : : * All required SCRAM options are set by postgres_fdw, so we just need to
2701 : : * ensure that these options are not overwritten by the user.
2702 : : */
2703 : : static bool
407 peter@eisentraut.org 2704 : 9 : pgfdw_has_required_scram_options(const char **keywords, const char **values)
2705 : : {
2706 : 9 : bool has_scram_server_key = false;
2707 : 9 : bool has_scram_client_key = false;
2708 : 9 : bool has_require_auth = false;
2709 : 9 : bool has_scram_keys = false;
2710 : :
2711 : : /*
2712 : : * Continue iterating even if we found the keys that we need to validate
2713 : : * to make sure that there is no other declaration of these keys that can
2714 : : * overwrite the first.
2715 : : */
2716 [ + + ]: 90 : for (int i = 0; keywords[i] != NULL; i++)
2717 : : {
2718 [ + + ]: 81 : if (strcmp(keywords[i], "scram_client_key") == 0)
2719 : : {
2720 [ + - + - ]: 9 : if (values[i] != NULL && values[i][0] != '\0')
2721 : 9 : has_scram_client_key = true;
2722 : : else
407 peter@eisentraut.org 2723 :UBC 0 : has_scram_client_key = false;
2724 : : }
2725 : :
407 peter@eisentraut.org 2726 [ + + ]:CBC 81 : if (strcmp(keywords[i], "scram_server_key") == 0)
2727 : : {
2728 [ + - + - ]: 9 : if (values[i] != NULL && values[i][0] != '\0')
2729 : 9 : has_scram_server_key = true;
2730 : : else
407 peter@eisentraut.org 2731 :UBC 0 : has_scram_server_key = false;
2732 : : }
2733 : :
407 peter@eisentraut.org 2734 [ + + ]:CBC 81 : if (strcmp(keywords[i], "require_auth") == 0)
2735 : : {
2736 [ + - + - ]: 9 : if (values[i] != NULL && strcmp(values[i], "scram-sha-256") == 0)
2737 : 9 : has_require_auth = true;
2738 : : else
407 peter@eisentraut.org 2739 :UBC 0 : has_require_auth = false;
2740 : : }
2741 : : }
2742 : :
270 peter@eisentraut.org 2743 [ + - + - :CBC 9 : has_scram_keys = has_scram_client_key && has_scram_server_key && MyProcPort != NULL && MyProcPort->has_scram_keys;
+ - + - ]
2744 : :
407 2745 [ + - + - ]: 9 : return (has_scram_keys && has_require_auth);
2746 : : }
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