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) 2012-2025, 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/xact.h"
20 : : #include "catalog/pg_user_mapping.h"
21 : : #include "commands/defrem.h"
22 : : #include "common/base64.h"
23 : : #include "funcapi.h"
24 : : #include "libpq/libpq-be.h"
25 : : #include "libpq/libpq-be-fe-helpers.h"
26 : : #include "mb/pg_wchar.h"
27 : : #include "miscadmin.h"
28 : : #include "pgstat.h"
29 : : #include "postgres_fdw.h"
30 : : #include "storage/latch.h"
31 : : #include "utils/builtins.h"
32 : : #include "utils/hsearch.h"
33 : : #include "utils/inval.h"
34 : : #include "utils/syscache.h"
35 : :
36 : : /*
37 : : * Connection cache hash table entry
38 : : *
39 : : * The lookup key in this hash table is the user mapping OID. We use just one
40 : : * connection per user mapping ID, which ensures that all the scans use the
41 : : * same snapshot during a query. Using the user mapping OID rather than
42 : : * the foreign server OID + user OID avoids creating multiple connections when
43 : : * the public user mapping applies to all user OIDs.
44 : : *
45 : : * The "conn" pointer can be NULL if we don't currently have a live connection.
46 : : * When we do have a connection, xact_depth tracks the current depth of
47 : : * transactions and subtransactions open on the remote side. We need to issue
48 : : * commands at the same nesting depth on the remote as we're executing at
49 : : * ourselves, so that rolling back a subtransaction will kill the right
50 : : * queries and not the wrong ones.
51 : : */
52 : : typedef Oid ConnCacheKey;
53 : :
54 : : typedef struct ConnCacheEntry
55 : : {
56 : : ConnCacheKey key; /* hash key (must be first) */
57 : : PGconn *conn; /* connection to foreign server, or NULL */
58 : : /* Remaining fields are invalid when conn is NULL: */
59 : : int xact_depth; /* 0 = no xact open, 1 = main xact open, 2 =
60 : : * one level of subxact open, etc */
61 : : bool have_prep_stmt; /* have we prepared any stmts in this xact? */
62 : : bool have_error; /* have any subxacts aborted in this xact? */
63 : : bool changing_xact_state; /* xact state change in process */
64 : : bool parallel_commit; /* do we commit (sub)xacts in parallel? */
65 : : bool parallel_abort; /* do we abort (sub)xacts in parallel? */
66 : : bool invalidated; /* true if reconnect is pending */
67 : : bool keep_connections; /* setting value of keep_connections
68 : : * server option */
69 : : Oid serverid; /* foreign server OID used to get server name */
70 : : uint32 server_hashvalue; /* hash value of foreign server OID */
71 : : uint32 mapping_hashvalue; /* hash value of user mapping OID */
72 : : PgFdwConnState state; /* extra per-connection state */
73 : : } ConnCacheEntry;
74 : :
75 : : /*
76 : : * Connection cache (initialized on first use)
77 : : */
78 : : static HTAB *ConnectionHash = NULL;
79 : :
80 : : /* for assigning cursor numbers and prepared statement numbers */
81 : : static unsigned int cursor_number = 0;
82 : : static unsigned int prep_stmt_number = 0;
83 : :
84 : : /* tracks whether any work is needed in callback functions */
85 : : static bool xact_got_connection = false;
86 : :
87 : : /* custom wait event values, retrieved from shared memory */
88 : : static uint32 pgfdw_we_cleanup_result = 0;
89 : : static uint32 pgfdw_we_connect = 0;
90 : : static uint32 pgfdw_we_get_result = 0;
91 : :
92 : : /*
93 : : * Milliseconds to wait to cancel an in-progress query or execute a cleanup
94 : : * query; if it takes longer than 30 seconds to do these, we assume the
95 : : * connection is dead.
96 : : */
97 : : #define CONNECTION_CLEANUP_TIMEOUT 30000
98 : :
99 : : /*
100 : : * Milliseconds to wait before issuing another cancel request. This covers
101 : : * the race condition where the remote session ignored our cancel request
102 : : * because it arrived while idle.
103 : : */
104 : : #define RETRY_CANCEL_TIMEOUT 1000
105 : :
106 : : /* Macro for constructing abort command to be sent */
107 : : #define CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel) \
108 : : do { \
109 : : if (toplevel) \
110 : : snprintf((sql), sizeof(sql), \
111 : : "ABORT TRANSACTION"); \
112 : : else \
113 : : snprintf((sql), sizeof(sql), \
114 : : "ROLLBACK TO SAVEPOINT s%d; RELEASE SAVEPOINT s%d", \
115 : : (entry)->xact_depth, (entry)->xact_depth); \
116 : : } while(0)
117 : :
118 : : /*
119 : : * Extension version number, for supporting older extension versions' objects
120 : : */
121 : : enum pgfdwVersion
122 : : {
123 : : PGFDW_V1_1 = 0,
124 : : PGFDW_V1_2,
125 : : };
126 : :
127 : : /*
128 : : * SQL functions
129 : : */
1692 fujii@postgresql.org 130 :CBC 3 : PG_FUNCTION_INFO_V1(postgres_fdw_get_connections);
407 131 : 4 : PG_FUNCTION_INFO_V1(postgres_fdw_get_connections_1_2);
1684 132 : 4 : PG_FUNCTION_INFO_V1(postgres_fdw_disconnect);
133 : 4 : PG_FUNCTION_INFO_V1(postgres_fdw_disconnect_all);
134 : :
135 : : /* prototypes of private functions */
136 : : static void make_new_connection(ConnCacheEntry *entry, UserMapping *user);
137 : : static PGconn *connect_pg_server(ForeignServer *server, UserMapping *user);
138 : : static void disconnect_pg_server(ConnCacheEntry *entry);
139 : : static void check_conn_params(const char **keywords, const char **values, UserMapping *user);
140 : : static void configure_remote_session(PGconn *conn);
141 : : static void do_sql_command_begin(PGconn *conn, const char *sql);
142 : : static void do_sql_command_end(PGconn *conn, const char *sql,
143 : : bool consume_input);
144 : : static void begin_remote_xact(ConnCacheEntry *entry);
145 : : static void pgfdw_report_internal(int elevel, PGresult *res, PGconn *conn,
146 : : const char *sql);
147 : : static void pgfdw_xact_callback(XactEvent event, void *arg);
148 : : static void pgfdw_subxact_callback(SubXactEvent event,
149 : : SubTransactionId mySubid,
150 : : SubTransactionId parentSubid,
151 : : void *arg);
152 : : static void pgfdw_inval_callback(Datum arg, int cacheid, uint32 hashvalue);
153 : : static void pgfdw_reject_incomplete_xact_state_change(ConnCacheEntry *entry);
154 : : static void pgfdw_reset_xact_state(ConnCacheEntry *entry, bool toplevel);
155 : : static bool pgfdw_cancel_query(PGconn *conn);
156 : : static bool pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime);
157 : : static bool pgfdw_cancel_query_end(PGconn *conn, TimestampTz endtime,
158 : : TimestampTz retrycanceltime,
159 : : bool consume_input);
160 : : static bool pgfdw_exec_cleanup_query(PGconn *conn, const char *query,
161 : : bool ignore_errors);
162 : : static bool pgfdw_exec_cleanup_query_begin(PGconn *conn, const char *query);
163 : : static bool pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query,
164 : : TimestampTz endtime,
165 : : bool consume_input,
166 : : bool ignore_errors);
167 : : static bool pgfdw_get_cleanup_result(PGconn *conn, TimestampTz endtime,
168 : : TimestampTz retrycanceltime,
169 : : PGresult **result, bool *timed_out);
170 : : static void pgfdw_abort_cleanup(ConnCacheEntry *entry, bool toplevel);
171 : : static bool pgfdw_abort_cleanup_begin(ConnCacheEntry *entry, bool toplevel,
172 : : List **pending_entries,
173 : : List **cancel_requested);
174 : : static void pgfdw_finish_pre_commit_cleanup(List *pending_entries);
175 : : static void pgfdw_finish_pre_subcommit_cleanup(List *pending_entries,
176 : : int curlevel);
177 : : static void pgfdw_finish_abort_cleanup(List *pending_entries,
178 : : List *cancel_requested,
179 : : bool toplevel);
180 : : static void pgfdw_security_check(const char **keywords, const char **values,
181 : : UserMapping *user, PGconn *conn);
182 : : static bool UserMappingPasswordRequired(UserMapping *user);
183 : : static bool UseScramPassthrough(ForeignServer *server, UserMapping *user);
184 : : static bool disconnect_cached_connections(Oid serverid);
185 : : static void postgres_fdw_get_connections_internal(FunctionCallInfo fcinfo,
186 : : enum pgfdwVersion api_version);
187 : : static int pgfdw_conn_check(PGconn *conn);
188 : : static bool pgfdw_conn_checkable(void);
189 : : static bool pgfdw_has_required_scram_options(const char **keywords, const char **values);
190 : :
191 : : /*
192 : : * Get a PGconn which can be used to execute queries on the remote PostgreSQL
193 : : * server with the user's authorization. A new connection is established
194 : : * if we don't already have a suitable one, and a transaction is opened at
195 : : * the right subtransaction nesting depth if we didn't do that already.
196 : : *
197 : : * will_prep_stmt must be true if caller intends to create any prepared
198 : : * statements. Since those don't go away automatically at transaction end
199 : : * (not even on error), we need this flag to cue manual cleanup.
200 : : *
201 : : * If state is not NULL, *state receives the per-connection state associated
202 : : * with the PGconn.
203 : : */
204 : : PGconn *
1620 efujita@postgresql.o 205 : 2205 : GetConnection(UserMapping *user, bool will_prep_stmt, PgFdwConnState **state)
206 : : {
207 : : bool found;
1786 fujii@postgresql.org 208 : 2205 : bool retry = false;
209 : : ConnCacheEntry *entry;
210 : : ConnCacheKey key;
211 : 2205 : MemoryContext ccxt = CurrentMemoryContext;
212 : :
213 : : /* First time through, initialize connection cache hashtable */
4580 tgl@sss.pgh.pa.us 214 [ + + ]: 2205 : if (ConnectionHash == NULL)
215 : : {
216 : : HASHCTL ctl;
217 : :
607 noah@leadboat.com 218 [ + - ]: 14 : if (pgfdw_we_get_result == 0)
219 : 14 : pgfdw_we_get_result =
220 : 14 : WaitEventExtensionNew("PostgresFdwGetResult");
221 : :
4580 tgl@sss.pgh.pa.us 222 : 14 : ctl.keysize = sizeof(ConnCacheKey);
223 : 14 : ctl.entrysize = sizeof(ConnCacheEntry);
224 : 14 : ConnectionHash = hash_create("postgres_fdw connections", 8,
225 : : &ctl,
226 : : HASH_ELEM | HASH_BLOBS);
227 : :
228 : : /*
229 : : * Register some callback functions that manage connection cleanup.
230 : : * This should be done just once in each backend.
231 : : */
232 : 14 : RegisterXactCallback(pgfdw_xact_callback, NULL);
233 : 14 : RegisterSubXactCallback(pgfdw_subxact_callback, NULL);
2969 234 : 14 : CacheRegisterSyscacheCallback(FOREIGNSERVEROID,
235 : : pgfdw_inval_callback, (Datum) 0);
236 : 14 : CacheRegisterSyscacheCallback(USERMAPPINGOID,
237 : : pgfdw_inval_callback, (Datum) 0);
238 : : }
239 : :
240 : : /* Set flag that we did GetConnection during the current transaction */
4580 241 : 2205 : xact_got_connection = true;
242 : :
243 : : /* Create hash key for the entry. Assume no pad bytes in key struct */
3509 rhaas@postgresql.org 244 : 2205 : key = user->umid;
245 : :
246 : : /*
247 : : * Find or create cached entry for requested connection.
248 : : */
4580 tgl@sss.pgh.pa.us 249 : 2205 : entry = hash_search(ConnectionHash, &key, HASH_ENTER, &found);
250 [ + + ]: 2205 : if (!found)
251 : : {
252 : : /*
253 : : * We need only clear "conn" here; remaining fields will be filled
254 : : * later when "conn" is set.
255 : : */
256 : 22 : entry->conn = NULL;
257 : : }
258 : :
259 : : /* Reject further use of connections which failed abort cleanup. */
3013 rhaas@postgresql.org 260 : 2205 : pgfdw_reject_incomplete_xact_state_change(entry);
261 : :
262 : : /*
263 : : * If the connection needs to be remade due to invalidation, disconnect as
264 : : * soon as we're out of all transactions.
265 : : */
1786 fujii@postgresql.org 266 [ + + - + : 2205 : if (entry->conn != NULL && entry->invalidated && entry->xact_depth == 0)
- - ]
267 : : {
1786 fujii@postgresql.org 268 [ # # ]:UBC 0 : elog(DEBUG3, "closing connection %p for option changes to take effect",
269 : : entry->conn);
2969 tgl@sss.pgh.pa.us 270 : 0 : disconnect_pg_server(entry);
271 : : }
272 : :
273 : : /*
274 : : * If cache entry doesn't have a connection, we have to establish a new
275 : : * connection. (If connect_pg_server throws an error, the cache entry
276 : : * will remain in a valid empty state, ie conn == NULL.)
277 : : */
4580 tgl@sss.pgh.pa.us 278 [ + + ]:CBC 2205 : if (entry->conn == NULL)
1786 fujii@postgresql.org 279 : 82 : make_new_connection(entry, user);
280 : :
281 : : /*
282 : : * We check the health of the cached connection here when using it. In
283 : : * cases where we're out of all transactions, if a broken connection is
284 : : * detected, we try to reestablish a new connection later.
285 : : */
1796 286 [ + + ]: 2196 : PG_TRY();
287 : : {
288 : : /* Process a pending asynchronous request if any. */
1620 efujita@postgresql.o 289 [ - + ]: 2196 : if (entry->state.pendingAreq)
1620 efujita@postgresql.o 290 :UBC 0 : process_pending_request(entry->state.pendingAreq);
291 : : /* Start a new transaction or subtransaction if needed. */
1796 fujii@postgresql.org 292 :CBC 2196 : begin_remote_xact(entry);
293 : : }
294 : 2 : PG_CATCH();
295 : : {
1786 296 : 2 : MemoryContext ecxt = MemoryContextSwitchTo(ccxt);
297 : 2 : ErrorData *errdata = CopyErrorData();
298 : :
299 : : /*
300 : : * Determine whether to try to reestablish the connection.
301 : : *
302 : : * After a broken connection is detected in libpq, any error other
303 : : * than connection failure (e.g., out-of-memory) can be thrown
304 : : * somewhere between return from libpq and the expected ereport() call
305 : : * in pgfdw_report_error(). In this case, since PQstatus() indicates
306 : : * CONNECTION_BAD, checking only PQstatus() causes the false detection
307 : : * of connection failure. To avoid this, we also verify that the
308 : : * error's sqlstate is ERRCODE_CONNECTION_FAILURE. Note that also
309 : : * checking only the sqlstate can cause another false detection
310 : : * because pgfdw_report_error() may report ERRCODE_CONNECTION_FAILURE
311 : : * for any libpq-originated error condition.
312 : : */
313 [ + - ]: 2 : if (errdata->sqlerrcode != ERRCODE_CONNECTION_FAILURE ||
314 [ + - ]: 2 : PQstatus(entry->conn) != CONNECTION_BAD ||
315 [ + + ]: 2 : entry->xact_depth > 0)
316 : : {
317 : 1 : MemoryContextSwitchTo(ecxt);
1796 318 : 1 : PG_RE_THROW();
319 : : }
320 : :
321 : : /* Clean up the error state */
1786 322 : 1 : FlushErrorState();
323 : 1 : FreeErrorData(errdata);
324 : 1 : errdata = NULL;
325 : :
326 : 1 : retry = true;
327 : : }
1796 328 [ - + ]: 2195 : PG_END_TRY();
329 : :
330 : : /*
331 : : * If a broken connection is detected, disconnect it, reestablish a new
332 : : * connection and retry a new remote transaction. If connection failure is
333 : : * reported again, we give up getting a connection.
334 : : */
1786 335 [ + + ]: 2195 : if (retry)
336 : : {
337 [ - + ]: 1 : Assert(entry->xact_depth == 0);
338 : :
1796 339 [ - + ]: 1 : ereport(DEBUG3,
340 : : (errmsg_internal("could not start remote transaction on connection %p",
341 : : entry->conn)),
342 : : errdetail_internal("%s", pchomp(PQerrorMessage(entry->conn))));
343 : :
1786 344 [ - + ]: 1 : elog(DEBUG3, "closing connection %p to reestablish a new one",
345 : : entry->conn);
346 : 1 : disconnect_pg_server(entry);
347 : :
904 efujita@postgresql.o 348 : 1 : make_new_connection(entry, user);
349 : :
1786 fujii@postgresql.org 350 : 1 : begin_remote_xact(entry);
351 : : }
352 : :
353 : : /* Remember if caller will prepare statements */
4563 tgl@sss.pgh.pa.us 354 : 2195 : entry->have_prep_stmt |= will_prep_stmt;
355 : :
356 : : /* If caller needs access to the per-connection state, return it. */
1620 efujita@postgresql.o 357 [ + + ]: 2195 : if (state)
358 : 748 : *state = &entry->state;
359 : :
4580 tgl@sss.pgh.pa.us 360 : 2195 : return entry->conn;
361 : : }
362 : :
363 : : /*
364 : : * Reset all transient state fields in the cached connection entry and
365 : : * establish new connection to the remote server.
366 : : */
367 : : static void
1786 fujii@postgresql.org 368 : 83 : make_new_connection(ConnCacheEntry *entry, UserMapping *user)
369 : : {
370 : 83 : ForeignServer *server = GetForeignServer(user->serverid);
371 : : ListCell *lc;
372 : :
373 [ - + ]: 83 : Assert(entry->conn == NULL);
374 : :
375 : : /* Reset all transient state fields, to be sure all are clean */
376 : 83 : entry->xact_depth = 0;
377 : 83 : entry->have_prep_stmt = false;
378 : 83 : entry->have_error = false;
379 : 83 : entry->changing_xact_state = false;
380 : 83 : entry->invalidated = false;
1695 381 : 83 : entry->serverid = server->serverid;
1786 382 : 83 : entry->server_hashvalue =
383 : 83 : GetSysCacheHashValue1(FOREIGNSERVEROID,
384 : : ObjectIdGetDatum(server->serverid));
385 : 83 : entry->mapping_hashvalue =
386 : 83 : GetSysCacheHashValue1(USERMAPPINGOID,
387 : : ObjectIdGetDatum(user->umid));
1620 efujita@postgresql.o 388 : 83 : memset(&entry->state, 0, sizeof(entry->state));
389 : :
390 : : /*
391 : : * Determine whether to keep the connection that we're about to make here
392 : : * open even after the transaction using it ends, so that the subsequent
393 : : * transactions can re-use it.
394 : : *
395 : : * By default, all the connections to any foreign servers are kept open.
396 : : *
397 : : * Also determine whether to commit/abort (sub)transactions opened on the
398 : : * remote server in parallel at (sub)transaction end, which is disabled by
399 : : * default.
400 : : *
401 : : * Note: it's enough to determine these only when making a new connection
402 : : * because if these settings for it are changed, it will be closed and
403 : : * re-made later.
404 : : */
1618 fujii@postgresql.org 405 : 83 : entry->keep_connections = true;
1290 efujita@postgresql.o 406 : 83 : entry->parallel_commit = false;
884 407 : 83 : entry->parallel_abort = false;
1618 fujii@postgresql.org 408 [ + - + + : 382 : foreach(lc, server->options)
+ + ]
409 : : {
410 : 299 : DefElem *def = (DefElem *) lfirst(lc);
411 : :
412 [ + + ]: 299 : if (strcmp(def->defname, "keep_connections") == 0)
413 : 13 : entry->keep_connections = defGetBoolean(def);
1290 efujita@postgresql.o 414 [ + + ]: 286 : else if (strcmp(def->defname, "parallel_commit") == 0)
415 : 2 : entry->parallel_commit = defGetBoolean(def);
884 416 [ + + ]: 284 : else if (strcmp(def->defname, "parallel_abort") == 0)
417 : 2 : entry->parallel_abort = defGetBoolean(def);
418 : : }
419 : :
420 : : /* Now try to make the connection */
1786 fujii@postgresql.org 421 : 83 : entry->conn = connect_pg_server(server, user);
422 : :
423 [ - + ]: 74 : elog(DEBUG3, "new postgres_fdw connection %p for server \"%s\" (user mapping oid %u, userid %u)",
424 : : entry->conn, server->servername, user->umid, user->userid);
425 : 74 : }
426 : :
427 : : /*
428 : : * Check that non-superuser has used password or delegated credentials
429 : : * to establish connection; otherwise, he's piggybacking on the
430 : : * postgres server's user identity. See also dblink_security_check()
431 : : * in contrib/dblink and check_conn_params.
432 : : */
433 : : static void
877 sfrost@snowman.net 434 : 77 : pgfdw_security_check(const char **keywords, const char **values, UserMapping *user, PGconn *conn)
435 : : {
436 : : /* Superusers bypass the check */
437 [ + + ]: 77 : if (superuser_arg(user->userid))
438 : 66 : return;
439 : :
440 : : #ifdef ENABLE_GSS
441 : : /* Connected via GSSAPI with delegated credentials- all good. */
840 bruce@momjian.us 442 [ + + + - ]: 11 : if (PQconnectionUsedGSSAPI(conn) && be_gssapi_get_delegation(MyProcPort))
877 sfrost@snowman.net 443 : 2 : return;
444 : : #endif
445 : :
446 : : /* Ok if superuser set PW required false. */
447 [ + + ]: 9 : if (!UserMappingPasswordRequired(user))
448 : 2 : return;
449 : :
450 : : /* Connected via PW, with PW required true, and provided non-empty PW. */
451 [ + + ]: 7 : if (PQconnectionUsedPassword(conn))
452 : : {
453 : : /* ok if params contain a non-empty password */
454 [ + + ]: 47 : for (int i = 0; keywords[i] != NULL; i++)
455 : : {
456 [ - + - - ]: 42 : if (strcmp(keywords[i], "password") == 0 && values[i][0] != '\0')
877 sfrost@snowman.net 457 :UBC 0 : return;
458 : : }
459 : : }
460 : :
461 : : /*
462 : : * Ok if SCRAM pass-through is being used and all required SCRAM options
463 : : * are set correctly. If pgfdw_has_required_scram_options returns true we
464 : : * assume that UseScramPassthrough is also true since SCRAM options are
465 : : * only set when UseScramPassthrough is enabled.
466 : : */
29 peter@eisentraut.org 467 [ + - + + :CBC 7 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && pgfdw_has_required_scram_options(keywords, values))
+ - ]
166 468 : 4 : return;
469 : :
877 sfrost@snowman.net 470 [ + - ]: 3 : ereport(ERROR,
471 : : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
472 : : errmsg("password or GSSAPI delegated credentials required"),
473 : : errdetail("Non-superuser cannot connect if the server does not request a password or use GSSAPI with delegated credentials."),
474 : : errhint("Target server's authentication method must be changed or password_required=false set in the user mapping attributes.")));
475 : : }
476 : :
477 : : /*
478 : : * Connect to remote server using specified server and user mapping properties.
479 : : */
480 : : static PGconn *
4580 tgl@sss.pgh.pa.us 481 : 83 : connect_pg_server(ForeignServer *server, UserMapping *user)
482 : : {
483 : 83 : PGconn *volatile conn = NULL;
484 : :
485 : : /*
486 : : * Use PG_TRY block to ensure closing connection on error.
487 : : */
488 [ + + ]: 83 : PG_TRY();
489 : : {
490 : : const char **keywords;
491 : : const char **values;
1352 fujii@postgresql.org 492 : 83 : char *appname = NULL;
493 : : int n;
494 : :
495 : : /*
496 : : * Construct connection params from generic options of ForeignServer
497 : : * and UserMapping. (Some of them might not be libpq options, in
498 : : * which case we'll just waste a few array slots.) Add 4 extra slots
499 : : * for application_name, fallback_application_name, client_encoding,
500 : : * end marker, and 3 extra slots for scram keys and required scram
501 : : * pass-through options.
502 : : */
166 peter@eisentraut.org 503 : 83 : n = list_length(server->options) + list_length(user->options) + 4 + 3;
4580 tgl@sss.pgh.pa.us 504 : 83 : keywords = (const char **) palloc(n * sizeof(char *));
505 : 83 : values = (const char **) palloc(n * sizeof(char *));
506 : :
507 : 83 : n = 0;
508 : 166 : n += ExtractConnectionOptions(server->options,
509 : 83 : keywords + n, values + n);
510 : 166 : n += ExtractConnectionOptions(user->options,
511 : 83 : keywords + n, values + n);
512 : :
513 : : /*
514 : : * Use pgfdw_application_name as application_name if set.
515 : : *
516 : : * PQconnectdbParams() processes the parameter arrays from start to
517 : : * end. If any key word is repeated, the last value is used. Therefore
518 : : * note that pgfdw_application_name must be added to the arrays after
519 : : * options of ForeignServer are, so that it can override
520 : : * application_name set in ForeignServer.
521 : : */
1460 fujii@postgresql.org 522 [ + + + - ]: 83 : if (pgfdw_application_name && *pgfdw_application_name != '\0')
523 : : {
524 : 1 : keywords[n] = "application_name";
525 : 1 : values[n] = pgfdw_application_name;
526 : 1 : n++;
527 : : }
528 : :
529 : : /*
530 : : * Search the parameter arrays to find application_name setting, and
531 : : * replace escape sequences in it with status information if found.
532 : : * The arrays are searched backwards because the last value is used if
533 : : * application_name is repeatedly set.
534 : : */
1352 535 [ + + ]: 228 : for (int i = n - 1; i >= 0; i--)
536 : : {
537 [ + + ]: 168 : if (strcmp(keywords[i], "application_name") == 0 &&
538 [ + - ]: 23 : *(values[i]) != '\0')
539 : : {
540 : : /*
541 : : * Use this application_name setting if it's not empty string
542 : : * even after any escape sequences in it are replaced.
543 : : */
544 : 23 : appname = process_pgfdw_appname(values[i]);
545 [ + - ]: 23 : if (appname[0] != '\0')
546 : : {
547 : 23 : values[i] = appname;
548 : 23 : break;
549 : : }
550 : :
551 : : /*
552 : : * This empty application_name is not used, so we set
553 : : * values[i] to NULL and keep searching the array to find the
554 : : * next one.
555 : : */
1352 fujii@postgresql.org 556 :UBC 0 : values[i] = NULL;
557 : 0 : pfree(appname);
558 : 0 : appname = NULL;
559 : : }
560 : : }
561 : :
562 : : /* Use "postgres_fdw" as fallback_application_name */
4580 tgl@sss.pgh.pa.us 563 :CBC 83 : keywords[n] = "fallback_application_name";
564 : 83 : values[n] = "postgres_fdw";
565 : 83 : n++;
566 : :
567 : : /* Set client_encoding so that libpq can convert encoding properly. */
568 : 83 : keywords[n] = "client_encoding";
569 : 83 : values[n] = GetDatabaseEncodingName();
570 : 83 : n++;
571 : :
572 : : /* Add required SCRAM pass-through connection options if it's enabled. */
29 peter@eisentraut.org 573 [ + - + + : 83 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && UseScramPassthrough(server, user))
+ - ]
574 : : {
575 : : int len;
576 : : int encoded_len;
577 : :
234 578 : 4 : keywords[n] = "scram_client_key";
579 : 4 : len = pg_b64_enc_len(sizeof(MyProcPort->scram_ClientKey));
580 : : /* don't forget the zero-terminator */
581 : 4 : values[n] = palloc0(len + 1);
121 heikki.linnakangas@i 582 : 8 : encoded_len = pg_b64_encode(MyProcPort->scram_ClientKey,
583 : : sizeof(MyProcPort->scram_ClientKey),
233 peter@eisentraut.org 584 : 4 : (char *) values[n], len);
585 [ - + ]: 4 : if (encoded_len < 0)
233 peter@eisentraut.org 586 [ # # ]:UBC 0 : elog(ERROR, "could not encode SCRAM client key");
234 peter@eisentraut.org 587 :CBC 4 : n++;
588 : :
589 : 4 : keywords[n] = "scram_server_key";
590 : 4 : len = pg_b64_enc_len(sizeof(MyProcPort->scram_ServerKey));
591 : : /* don't forget the zero-terminator */
592 : 4 : values[n] = palloc0(len + 1);
121 heikki.linnakangas@i 593 : 8 : encoded_len = pg_b64_encode(MyProcPort->scram_ServerKey,
594 : : sizeof(MyProcPort->scram_ServerKey),
233 peter@eisentraut.org 595 : 4 : (char *) values[n], len);
596 [ - + ]: 4 : if (encoded_len < 0)
233 peter@eisentraut.org 597 [ # # ]:UBC 0 : elog(ERROR, "could not encode SCRAM server key");
234 peter@eisentraut.org 598 :CBC 4 : n++;
599 : :
600 : : /*
601 : : * Require scram-sha-256 to ensure that no other auth method is
602 : : * used when connecting with foreign server.
603 : : */
166 604 : 4 : keywords[n] = "require_auth";
605 : 4 : values[n] = "scram-sha-256";
606 : 4 : n++;
607 : : }
608 : :
4580 tgl@sss.pgh.pa.us 609 : 83 : keywords[n] = values[n] = NULL;
610 : :
611 : : /* Verify the set of connection parameters. */
166 peter@eisentraut.org 612 : 83 : check_conn_params(keywords, values, user);
613 : :
614 : : /* first time, allocate or get the custom wait event */
702 michael@paquier.xyz 615 [ + + ]: 79 : if (pgfdw_we_connect == 0)
616 : 12 : pgfdw_we_connect = WaitEventExtensionNew("PostgresFdwConnect");
617 : :
618 : : /* OK to make connection */
957 andres@anarazel.de 619 : 79 : conn = libpqsrv_connect_params(keywords, values,
620 : : false, /* expand_dbname */
621 : : pgfdw_we_connect);
622 : :
4580 tgl@sss.pgh.pa.us 623 [ + - + + ]: 79 : if (!conn || PQstatus(conn) != CONNECTION_OK)
624 [ + - ]: 2 : ereport(ERROR,
625 : : (errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
626 : : errmsg("could not connect to server \"%s\"",
627 : : server->servername),
628 : : errdetail_internal("%s", pchomp(PQerrorMessage(conn)))));
629 : :
46 fujii@postgresql.org 630 :GNC 77 : PQsetNoticeReceiver(conn, libpqsrv_notice_receiver,
631 : : "received message via remote connection");
632 : :
633 : : /* Perform post-connection security checks. */
166 peter@eisentraut.org 634 :CBC 77 : pgfdw_security_check(keywords, values, user, conn);
635 : :
636 : : /* Prepare new session for use */
4579 tgl@sss.pgh.pa.us 637 : 74 : configure_remote_session(conn);
638 : :
1352 fujii@postgresql.org 639 [ + + ]: 74 : if (appname != NULL)
640 : 23 : pfree(appname);
4580 tgl@sss.pgh.pa.us 641 : 74 : pfree(keywords);
642 : 74 : pfree(values);
643 : : }
644 : 9 : PG_CATCH();
645 : : {
957 andres@anarazel.de 646 : 9 : libpqsrv_disconnect(conn);
4580 tgl@sss.pgh.pa.us 647 : 9 : PG_RE_THROW();
648 : : }
649 [ - + ]: 74 : PG_END_TRY();
650 : :
651 : 74 : return conn;
652 : : }
653 : :
654 : : /*
655 : : * Disconnect any open connection for a connection cache entry.
656 : : */
657 : : static void
2969 658 : 63 : disconnect_pg_server(ConnCacheEntry *entry)
659 : : {
660 [ + - ]: 63 : if (entry->conn != NULL)
661 : : {
957 andres@anarazel.de 662 : 63 : libpqsrv_disconnect(entry->conn);
2969 tgl@sss.pgh.pa.us 663 : 63 : entry->conn = NULL;
664 : : }
665 : 63 : }
666 : :
667 : : /*
668 : : * Return true if the password_required is defined and false for this user
669 : : * mapping, otherwise false. The mapping has been pre-validated.
670 : : */
671 : : static bool
2087 andrew@dunslane.net 672 : 18 : UserMappingPasswordRequired(UserMapping *user)
673 : : {
674 : : ListCell *cell;
675 : :
676 [ + + + + : 32 : foreach(cell, user->options)
+ + ]
677 : : {
678 : 17 : DefElem *def = (DefElem *) lfirst(cell);
679 : :
680 [ + + ]: 17 : if (strcmp(def->defname, "password_required") == 0)
681 : 3 : return defGetBoolean(def);
682 : : }
683 : :
684 : 15 : return true;
685 : : }
686 : :
687 : : static bool
234 peter@eisentraut.org 688 : 4 : UseScramPassthrough(ForeignServer *server, UserMapping *user)
689 : : {
690 : : ListCell *cell;
691 : :
692 [ + - + - : 16 : foreach(cell, server->options)
+ - ]
693 : : {
694 : 16 : DefElem *def = (DefElem *) lfirst(cell);
695 : :
696 [ + + ]: 16 : if (strcmp(def->defname, "use_scram_passthrough") == 0)
697 : 4 : return defGetBoolean(def);
698 : : }
699 : :
234 peter@eisentraut.org 700 [ # # # # :UBC 0 : foreach(cell, user->options)
# # ]
701 : : {
702 : 0 : DefElem *def = (DefElem *) lfirst(cell);
703 : :
704 [ # # ]: 0 : if (strcmp(def->defname, "use_scram_passthrough") == 0)
705 : 0 : return defGetBoolean(def);
706 : : }
707 : :
708 : 0 : return false;
709 : : }
710 : :
711 : : /*
712 : : * For non-superusers, insist that the connstr specify a password or that the
713 : : * user provided their own GSSAPI delegated credentials. This
714 : : * prevents a password from being picked up from .pgpass, a service file, the
715 : : * environment, etc. We don't want the postgres user's passwords,
716 : : * certificates, etc to be accessible to non-superusers. (See also
717 : : * dblink_connstr_check in contrib/dblink.)
718 : : */
719 : : static void
2832 rhaas@postgresql.org 720 :CBC 83 : check_conn_params(const char **keywords, const char **values, UserMapping *user)
721 : : {
722 : : int i;
723 : :
724 : : /* no check required if superuser */
725 [ + + ]: 83 : if (superuser_arg(user->userid))
4580 tgl@sss.pgh.pa.us 726 : 68 : return;
727 : :
728 : : #ifdef ENABLE_GSS
729 : : /* ok if the user provided their own delegated credentials */
840 bruce@momjian.us 730 [ + + ]: 15 : if (be_gssapi_get_delegation(MyProcPort))
877 sfrost@snowman.net 731 : 3 : return;
732 : : #endif
733 : :
734 : : /* ok if params contain a non-empty password */
4580 tgl@sss.pgh.pa.us 735 [ + + ]: 79 : for (i = 0; keywords[i] != NULL; i++)
736 : : {
737 [ + + + - ]: 70 : if (strcmp(keywords[i], "password") == 0 && values[i][0] != '\0')
738 : 3 : return;
739 : : }
740 : :
741 : : /* ok if the superuser explicitly said so at user mapping creation time */
2087 andrew@dunslane.net 742 [ + + ]: 9 : if (!UserMappingPasswordRequired(user))
743 : 1 : return;
744 : :
745 : : /*
746 : : * Ok if SCRAM pass-through is being used and all required scram options
747 : : * are set correctly. If pgfdw_has_required_scram_options returns true we
748 : : * assume that UseScramPassthrough is also true since SCRAM options are
749 : : * only set when UseScramPassthrough is enabled.
750 : : */
29 peter@eisentraut.org 751 [ + - + + : 8 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && pgfdw_has_required_scram_options(keywords, values))
+ - ]
166 752 : 4 : return;
753 : :
4580 tgl@sss.pgh.pa.us 754 [ + - ]: 4 : ereport(ERROR,
755 : : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
756 : : errmsg("password or GSSAPI delegated credentials required"),
757 : : errdetail("Non-superusers must delegate GSSAPI credentials, provide a password, or enable SCRAM pass-through in user mapping.")));
758 : : }
759 : :
760 : : /*
761 : : * Issue SET commands to make sure remote session is configured properly.
762 : : *
763 : : * We do this just once at connection, assuming nothing will change the
764 : : * values later. Since we'll never send volatile function calls to the
765 : : * remote, there shouldn't be any way to break this assumption from our end.
766 : : * It's possible to think of ways to break it at the remote end, eg making
767 : : * a foreign table point to a view that includes a set_config call ---
768 : : * but once you admit the possibility of a malicious view definition,
769 : : * there are any number of ways to break things.
770 : : */
771 : : static void
4579 772 : 74 : configure_remote_session(PGconn *conn)
773 : : {
4562 774 : 74 : int remoteversion = PQserverVersion(conn);
775 : :
776 : : /* Force the search path to contain only pg_catalog (see deparse.c) */
777 : 74 : do_sql_command(conn, "SET search_path = pg_catalog");
778 : :
779 : : /*
780 : : * Set remote timezone; this is basically just cosmetic, since all
781 : : * transmitted and returned timestamptzs should specify a zone explicitly
782 : : * anyway. However it makes the regression test outputs more predictable.
783 : : *
784 : : * We don't risk setting remote zone equal to ours, since the remote
785 : : * server might use a different timezone database. Instead, use GMT
786 : : * (quoted, because very old servers are picky about case). That's
787 : : * guaranteed to work regardless of the remote's timezone database,
788 : : * because pg_tzset() hard-wires it (at least in PG 9.2 and later).
789 : : */
503 790 : 74 : do_sql_command(conn, "SET timezone = 'GMT'");
791 : :
792 : : /*
793 : : * Set values needed to ensure unambiguous data output from remote. (This
794 : : * logic should match what pg_dump does. See also set_transmission_modes
795 : : * in postgres_fdw.c.)
796 : : */
4562 797 : 74 : do_sql_command(conn, "SET datestyle = ISO");
798 [ + - ]: 74 : if (remoteversion >= 80400)
799 : 74 : do_sql_command(conn, "SET intervalstyle = postgres");
800 [ + - ]: 74 : if (remoteversion >= 90000)
801 : 74 : do_sql_command(conn, "SET extra_float_digits = 3");
802 : : else
4562 tgl@sss.pgh.pa.us 803 :UBC 0 : do_sql_command(conn, "SET extra_float_digits = 2");
4562 tgl@sss.pgh.pa.us 804 :CBC 74 : }
805 : :
806 : : /*
807 : : * Convenience subroutine to issue a non-data-returning SQL command to remote
808 : : */
809 : : void
810 : 1839 : do_sql_command(PGconn *conn, const char *sql)
811 : : {
1290 efujita@postgresql.o 812 : 1839 : do_sql_command_begin(conn, sql);
813 : 1839 : do_sql_command_end(conn, sql, false);
814 : 1836 : }
815 : :
816 : : static void
817 : 1857 : do_sql_command_begin(PGconn *conn, const char *sql)
818 : : {
3013 rhaas@postgresql.org 819 [ - + ]: 1857 : if (!PQsendQuery(conn, sql))
39 tgl@sss.pgh.pa.us 820 :UNC 0 : pgfdw_report_error(NULL, conn, sql);
1290 efujita@postgresql.o 821 :CBC 1857 : }
822 : :
823 : : static void
824 : 1857 : do_sql_command_end(PGconn *conn, const char *sql, bool consume_input)
825 : : {
826 : : PGresult *res;
827 : :
828 : : /*
829 : : * If requested, consume whatever data is available from the socket. (Note
830 : : * that if all data is available, this allows pgfdw_get_result to call
831 : : * PQgetResult without forcing the overhead of WaitLatchOrSocket, which
832 : : * would be large compared to the overhead of PQconsumeInput.)
833 : : */
834 [ + + - + ]: 1857 : if (consume_input && !PQconsumeInput(conn))
39 tgl@sss.pgh.pa.us 835 :UNC 0 : pgfdw_report_error(NULL, conn, sql);
607 noah@leadboat.com 836 :CBC 1857 : res = pgfdw_get_result(conn);
4579 tgl@sss.pgh.pa.us 837 [ + + ]: 1857 : if (PQresultStatus(res) != PGRES_COMMAND_OK)
39 tgl@sss.pgh.pa.us 838 :GNC 3 : pgfdw_report_error(res, conn, sql);
4579 tgl@sss.pgh.pa.us 839 :CBC 1854 : PQclear(res);
840 : 1854 : }
841 : :
842 : : /*
843 : : * Start remote transaction or subtransaction, if needed.
844 : : *
845 : : * Note that we always use at least REPEATABLE READ in the remote session.
846 : : * This is so that, if a query initiates multiple scans of the same or
847 : : * different foreign tables, we will get snapshot-consistent results from
848 : : * those scans. A disadvantage is that we can't provide sane emulation of
849 : : * READ COMMITTED behavior --- it would be nice if we had some other way to
850 : : * control which remote queries share a snapshot.
851 : : */
852 : : static void
4580 853 : 2197 : begin_remote_xact(ConnCacheEntry *entry)
854 : : {
855 : 2197 : int curlevel = GetCurrentTransactionNestLevel();
856 : :
857 : : /* Start main transaction if we haven't yet */
858 [ + + ]: 2197 : if (entry->xact_depth <= 0)
859 : : {
860 : : const char *sql;
861 : :
862 [ - + ]: 753 : elog(DEBUG3, "starting remote transaction on connection %p",
863 : : entry->conn);
864 : :
865 [ - + ]: 753 : if (IsolationIsSerializable())
90 efujita@postgresql.o 866 :UBC 0 : sql = "START TRANSACTION ISOLATION LEVEL SERIALIZABLE";
867 : : else
90 efujita@postgresql.o 868 :CBC 753 : sql = "START TRANSACTION ISOLATION LEVEL REPEATABLE READ";
3013 rhaas@postgresql.org 869 : 753 : entry->changing_xact_state = true;
90 efujita@postgresql.o 870 : 753 : do_sql_command(entry->conn, sql);
4580 tgl@sss.pgh.pa.us 871 : 752 : entry->xact_depth = 1;
3013 rhaas@postgresql.org 872 : 752 : entry->changing_xact_state = false;
873 : : }
874 : :
875 : : /*
876 : : * If we're in a subtransaction, stack up savepoints to match our level.
877 : : * This ensures we can rollback just the desired effects when a
878 : : * subtransaction aborts.
879 : : */
4580 tgl@sss.pgh.pa.us 880 [ + + ]: 2210 : while (entry->xact_depth < curlevel)
881 : : {
882 : : char sql[64];
883 : :
90 efujita@postgresql.o 884 : 15 : snprintf(sql, sizeof(sql), "SAVEPOINT s%d", entry->xact_depth + 1);
3013 rhaas@postgresql.org 885 : 15 : entry->changing_xact_state = true;
90 efujita@postgresql.o 886 : 15 : do_sql_command(entry->conn, sql);
4580 tgl@sss.pgh.pa.us 887 : 14 : entry->xact_depth++;
3013 rhaas@postgresql.org 888 : 14 : entry->changing_xact_state = false;
889 : : }
4580 tgl@sss.pgh.pa.us 890 : 2195 : }
891 : :
892 : : /*
893 : : * Release connection reference count created by calling GetConnection.
894 : : */
895 : : void
896 : 2130 : ReleaseConnection(PGconn *conn)
897 : : {
898 : : /*
899 : : * Currently, we don't actually track connection references because all
900 : : * cleanup is managed on a transaction or subtransaction basis instead. So
901 : : * there's nothing to do here.
902 : : */
903 : 2130 : }
904 : :
905 : : /*
906 : : * Assign a "unique" number for a cursor.
907 : : *
908 : : * These really only need to be unique per connection within a transaction.
909 : : * For the moment we ignore the per-connection point and assign them across
910 : : * all connections in the transaction, but we ask for the connection to be
911 : : * supplied in case we want to refine that.
912 : : *
913 : : * Note that even if wraparound happens in a very long transaction, actual
914 : : * collisions are highly improbable; just be sure to use %u not %d to print.
915 : : */
916 : : unsigned int
917 : 541 : GetCursorNumber(PGconn *conn)
918 : : {
919 : 541 : return ++cursor_number;
920 : : }
921 : :
922 : : /*
923 : : * Assign a "unique" number for a prepared statement.
924 : : *
925 : : * This works much like GetCursorNumber, except that we never reset the counter
926 : : * within a session. That's because we can't be 100% sure we've gotten rid
927 : : * of all prepared statements on all connections, and it's not really worth
928 : : * increasing the risk of prepared-statement name collisions by resetting.
929 : : */
930 : : unsigned int
4563 931 : 187 : GetPrepStmtNumber(PGconn *conn)
932 : : {
933 : 187 : return ++prep_stmt_number;
934 : : }
935 : :
936 : : /*
937 : : * Submit a query and wait for the result.
938 : : *
939 : : * Since we don't use non-blocking mode, this can't process interrupts while
940 : : * pushing the query text to the server. That risk is relatively small, so we
941 : : * ignore that for now.
942 : : *
943 : : * Caller is responsible for the error handling on the result.
944 : : */
945 : : PGresult *
1620 efujita@postgresql.o 946 : 4074 : pgfdw_exec_query(PGconn *conn, const char *query, PgFdwConnState *state)
947 : : {
948 : : /* First, process a pending asynchronous request, if any. */
949 [ + + + + ]: 4074 : if (state && state->pendingAreq)
950 : 4 : process_pending_request(state->pendingAreq);
951 : :
3425 rhaas@postgresql.org 952 [ - + ]: 4074 : if (!PQsendQuery(conn, query))
607 noah@leadboat.com 953 :UBC 0 : return NULL;
607 noah@leadboat.com 954 :CBC 4074 : return pgfdw_get_result(conn);
955 : : }
956 : :
957 : : /*
958 : : * Wrap libpqsrv_get_result_last(), adding wait event.
959 : : *
960 : : * Caller is responsible for the error handling on the result.
961 : : */
962 : : PGresult *
963 : 8228 : pgfdw_get_result(PGconn *conn)
964 : : {
965 : 8228 : return libpqsrv_get_result_last(conn, pgfdw_we_get_result);
966 : : }
967 : :
968 : : /*
969 : : * Report an error we got from the remote server.
970 : : *
971 : : * Callers should use pgfdw_report_error() to throw an error, or use
972 : : * pgfdw_report() for lesser message levels. (We make this distinction
973 : : * so that pgfdw_report_error() can be marked noreturn.)
974 : : *
975 : : * res: PGresult containing the error (might be NULL)
976 : : * conn: connection we did the query on
977 : : * sql: NULL, or text of remote command we tried to execute
978 : : *
979 : : * If "res" is not NULL, it'll be PQclear'ed here (unless we throw error,
980 : : * in which case memory context cleanup will clear it eventually).
981 : : *
982 : : * Note: callers that choose not to throw ERROR for a remote error are
983 : : * responsible for making sure that the associated ConnCacheEntry gets
984 : : * marked with have_error = true.
985 : : */
986 : : void
39 tgl@sss.pgh.pa.us 987 :GNC 16 : pgfdw_report_error(PGresult *res, PGconn *conn, const char *sql)
988 : : {
989 : 16 : pgfdw_report_internal(ERROR, res, conn, sql);
39 tgl@sss.pgh.pa.us 990 :UNC 0 : pg_unreachable();
991 : : }
992 : :
993 : : void
994 : 0 : pgfdw_report(int elevel, PGresult *res, PGconn *conn, const char *sql)
995 : : {
996 [ # # ]: 0 : Assert(elevel < ERROR); /* use pgfdw_report_error for that */
997 : 0 : pgfdw_report_internal(elevel, res, conn, sql);
998 : 0 : }
999 : :
1000 : : static void
39 tgl@sss.pgh.pa.us 1001 :GNC 16 : pgfdw_report_internal(int elevel, PGresult *res, PGconn *conn,
1002 : : const char *sql)
1003 : : {
43 1004 : 16 : char *diag_sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
1005 : 16 : char *message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
1006 : 16 : char *message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL);
1007 : 16 : char *message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT);
1008 : 16 : char *message_context = PQresultErrorField(res, PG_DIAG_CONTEXT);
1009 : : int sqlstate;
1010 : :
1011 [ + + ]: 16 : if (diag_sqlstate)
1012 : 14 : sqlstate = MAKE_SQLSTATE(diag_sqlstate[0],
1013 : : diag_sqlstate[1],
1014 : : diag_sqlstate[2],
1015 : : diag_sqlstate[3],
1016 : : diag_sqlstate[4]);
1017 : : else
1018 : 2 : sqlstate = ERRCODE_CONNECTION_FAILURE;
1019 : :
1020 : : /*
1021 : : * If we don't get a message from the PGresult, try the PGconn. This is
1022 : : * needed because for connection-level failures, PQgetResult may just
1023 : : * return NULL, not a PGresult at all.
1024 : : */
1025 [ + + ]: 16 : if (message_primary == NULL)
1026 : 2 : message_primary = pchomp(PQerrorMessage(conn));
1027 : :
1028 [ + - + - : 16 : ereport(elevel,
+ - + + +
+ - + +
- ]
1029 : : (errcode(sqlstate),
1030 : : (message_primary != NULL && message_primary[0] != '\0') ?
1031 : : errmsg_internal("%s", message_primary) :
1032 : : errmsg("could not obtain message string for remote error"),
1033 : : message_detail ? errdetail_internal("%s", message_detail) : 0,
1034 : : message_hint ? errhint("%s", message_hint) : 0,
1035 : : message_context ? errcontext("%s", message_context) : 0,
1036 : : sql ? errcontext("remote SQL command: %s", sql) : 0));
43 tgl@sss.pgh.pa.us 1037 :UNC 0 : PQclear(res);
4580 tgl@sss.pgh.pa.us 1038 :UBC 0 : }
1039 : :
1040 : : /*
1041 : : * pgfdw_xact_callback --- cleanup at main-transaction end.
1042 : : *
1043 : : * This runs just late enough that it must not enter user-defined code
1044 : : * locally. (Entering such code on the remote side is fine. Its remote
1045 : : * COMMIT TRANSACTION may run deferred triggers.)
1046 : : */
1047 : : static void
4580 tgl@sss.pgh.pa.us 1048 :CBC 4034 : pgfdw_xact_callback(XactEvent event, void *arg)
1049 : : {
1050 : : HASH_SEQ_STATUS scan;
1051 : : ConnCacheEntry *entry;
1290 efujita@postgresql.o 1052 : 4034 : List *pending_entries = NIL;
884 1053 : 4034 : List *cancel_requested = NIL;
1054 : :
1055 : : /* Quick exit if no connections were touched in this transaction. */
4580 tgl@sss.pgh.pa.us 1056 [ + + ]: 4034 : if (!xact_got_connection)
1057 : 3310 : return;
1058 : :
1059 : : /*
1060 : : * Scan all connection cache entries to find open remote transactions, and
1061 : : * close them.
1062 : : */
1063 : 724 : hash_seq_init(&scan, ConnectionHash);
1064 [ + + ]: 3719 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1065 : : {
1066 : : PGresult *res;
1067 : :
1068 : : /* Ignore cache entry if no open connection right now */
4233 1069 [ + + ]: 2996 : if (entry->conn == NULL)
4580 1070 : 1706 : continue;
1071 : :
1072 : : /* If it has an open remote transaction, try to close it */
4233 1073 [ + + ]: 1290 : if (entry->xact_depth > 0)
1074 : : {
1075 [ - + ]: 753 : elog(DEBUG3, "closing remote transaction on connection %p",
1076 : : entry->conn);
1077 : :
1078 [ + + - + : 753 : switch (event)
- ]
1079 : : {
3782 rhaas@postgresql.org 1080 : 700 : case XACT_EVENT_PARALLEL_PRE_COMMIT:
1081 : : case XACT_EVENT_PRE_COMMIT:
1082 : :
1083 : : /*
1084 : : * If abort cleanup previously failed for this connection,
1085 : : * we can't issue any more commands against it.
1086 : : */
3013 1087 : 700 : pgfdw_reject_incomplete_xact_state_change(entry);
1088 : :
1089 : : /* Commit all remote transactions during pre-commit */
1090 : 700 : entry->changing_xact_state = true;
1290 efujita@postgresql.o 1091 [ + + ]: 700 : if (entry->parallel_commit)
1092 : : {
1093 : 16 : do_sql_command_begin(entry->conn, "COMMIT TRANSACTION");
1094 : 16 : pending_entries = lappend(pending_entries, entry);
1095 : 16 : continue;
1096 : : }
4233 tgl@sss.pgh.pa.us 1097 : 684 : do_sql_command(entry->conn, "COMMIT TRANSACTION");
3013 rhaas@postgresql.org 1098 : 684 : entry->changing_xact_state = false;
1099 : :
1100 : : /*
1101 : : * If there were any errors in subtransactions, and we
1102 : : * made prepared statements, do a DEALLOCATE ALL to make
1103 : : * sure we get rid of all prepared statements. This is
1104 : : * annoying and not terribly bulletproof, but it's
1105 : : * probably not worth trying harder.
1106 : : *
1107 : : * DEALLOCATE ALL only exists in 8.3 and later, so this
1108 : : * constrains how old a server postgres_fdw can
1109 : : * communicate with. We intentionally ignore errors in
1110 : : * the DEALLOCATE, so that we can hobble along to some
1111 : : * extent with older servers (leaking prepared statements
1112 : : * as we go; but we don't really support update operations
1113 : : * pre-8.3 anyway).
1114 : : */
4563 tgl@sss.pgh.pa.us 1115 [ + + - + ]: 684 : if (entry->have_prep_stmt && entry->have_error)
1116 : : {
607 noah@leadboat.com 1117 :UBC 0 : res = pgfdw_exec_query(entry->conn, "DEALLOCATE ALL",
1118 : : NULL);
4563 tgl@sss.pgh.pa.us 1119 : 0 : PQclear(res);
1120 : : }
4563 tgl@sss.pgh.pa.us 1121 :CBC 684 : entry->have_prep_stmt = false;
1122 : 684 : entry->have_error = false;
4233 1123 : 684 : break;
1124 : 1 : case XACT_EVENT_PRE_PREPARE:
1125 : :
1126 : : /*
1127 : : * We disallow any remote transactions, since it's not
1128 : : * very reasonable to hold them open until the prepared
1129 : : * transaction is committed. For the moment, throw error
1130 : : * unconditionally; later we might allow read-only cases.
1131 : : * Note that the error will cause us to come right back
1132 : : * here with event == XACT_EVENT_ABORT, so we'll clean up
1133 : : * the connection state at that point.
1134 : : */
1135 [ + - ]: 1 : ereport(ERROR,
1136 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1137 : : errmsg("cannot PREPARE a transaction that has operated on postgres_fdw foreign tables")));
1138 : : break;
3782 rhaas@postgresql.org 1139 :UBC 0 : case XACT_EVENT_PARALLEL_COMMIT:
1140 : : case XACT_EVENT_COMMIT:
1141 : : case XACT_EVENT_PREPARE:
1142 : : /* Pre-commit should have closed the open transaction */
4233 tgl@sss.pgh.pa.us 1143 [ # # ]: 0 : elog(ERROR, "missed cleaning up connection during pre-commit");
1144 : : break;
3782 rhaas@postgresql.org 1145 :CBC 52 : case XACT_EVENT_PARALLEL_ABORT:
1146 : : case XACT_EVENT_ABORT:
1147 : : /* Rollback all remote transactions during abort */
884 efujita@postgresql.o 1148 [ + + ]: 52 : if (entry->parallel_abort)
1149 : : {
1150 [ + - ]: 4 : if (pgfdw_abort_cleanup_begin(entry, true,
1151 : : &pending_entries,
1152 : : &cancel_requested))
1153 : 4 : continue;
1154 : : }
1155 : : else
1156 : 48 : pgfdw_abort_cleanup(entry, true);
4233 tgl@sss.pgh.pa.us 1157 : 48 : break;
1158 : : }
1159 : : }
1160 : :
1161 : : /* Reset state to show we're out of a transaction */
1290 efujita@postgresql.o 1162 : 1269 : pgfdw_reset_xact_state(entry, true);
1163 : : }
1164 : :
1165 : : /* If there are any pending connections, finish cleaning them up */
884 1166 [ + + - + ]: 723 : if (pending_entries || cancel_requested)
1167 : : {
1168 [ + - + + ]: 15 : if (event == XACT_EVENT_PARALLEL_PRE_COMMIT ||
1169 : : event == XACT_EVENT_PRE_COMMIT)
1170 : : {
1171 [ - + ]: 13 : Assert(cancel_requested == NIL);
1172 : 13 : pgfdw_finish_pre_commit_cleanup(pending_entries);
1173 : : }
1174 : : else
1175 : : {
1176 [ + - - + ]: 2 : Assert(event == XACT_EVENT_PARALLEL_ABORT ||
1177 : : event == XACT_EVENT_ABORT);
1178 : 2 : pgfdw_finish_abort_cleanup(pending_entries, cancel_requested,
1179 : : true);
1180 : : }
1181 : : }
1182 : :
1183 : : /*
1184 : : * Regardless of the event type, we can now mark ourselves as out of the
1185 : : * transaction. (Note: if we are here during PRE_COMMIT or PRE_PREPARE,
1186 : : * this saves a useless scan of the hashtable during COMMIT or PREPARE.)
1187 : : */
4580 tgl@sss.pgh.pa.us 1188 : 723 : xact_got_connection = false;
1189 : :
1190 : : /* Also reset cursor numbering for next transaction */
1191 : 723 : cursor_number = 0;
1192 : : }
1193 : :
1194 : : /*
1195 : : * pgfdw_subxact_callback --- cleanup at subtransaction end.
1196 : : */
1197 : : static void
1198 : 38 : pgfdw_subxact_callback(SubXactEvent event, SubTransactionId mySubid,
1199 : : SubTransactionId parentSubid, void *arg)
1200 : : {
1201 : : HASH_SEQ_STATUS scan;
1202 : : ConnCacheEntry *entry;
1203 : : int curlevel;
1290 efujita@postgresql.o 1204 : 38 : List *pending_entries = NIL;
884 1205 : 38 : List *cancel_requested = NIL;
1206 : :
1207 : : /* Nothing to do at subxact start, nor after commit. */
4580 tgl@sss.pgh.pa.us 1208 [ + + + + ]: 38 : if (!(event == SUBXACT_EVENT_PRE_COMMIT_SUB ||
1209 : : event == SUBXACT_EVENT_ABORT_SUB))
1210 : 23 : return;
1211 : :
1212 : : /* Quick exit if no connections were touched in this transaction. */
1213 [ - + ]: 15 : if (!xact_got_connection)
4580 tgl@sss.pgh.pa.us 1214 :UBC 0 : return;
1215 : :
1216 : : /*
1217 : : * Scan all connection cache entries to find open remote subtransactions
1218 : : * of the current level, and close them.
1219 : : */
4580 tgl@sss.pgh.pa.us 1220 :CBC 15 : curlevel = GetCurrentTransactionNestLevel();
1221 : 15 : hash_seq_init(&scan, ConnectionHash);
1222 [ + + ]: 102 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1223 : : {
1224 : : char sql[100];
1225 : :
1226 : : /*
1227 : : * We only care about connections with open remote subtransactions of
1228 : : * the current level.
1229 : : */
1230 [ + + + + ]: 87 : if (entry->conn == NULL || entry->xact_depth < curlevel)
1231 : 79 : continue;
1232 : :
1233 [ - + ]: 14 : if (entry->xact_depth > curlevel)
4580 tgl@sss.pgh.pa.us 1234 [ # # ]:UBC 0 : elog(ERROR, "missed cleaning up remote subtransaction at level %d",
1235 : : entry->xact_depth);
1236 : :
4580 tgl@sss.pgh.pa.us 1237 [ + + ]:CBC 14 : if (event == SUBXACT_EVENT_PRE_COMMIT_SUB)
1238 : : {
1239 : : /*
1240 : : * If abort cleanup previously failed for this connection, we
1241 : : * can't issue any more commands against it.
1242 : : */
3013 rhaas@postgresql.org 1243 : 7 : pgfdw_reject_incomplete_xact_state_change(entry);
1244 : :
1245 : : /* Commit all remote subtransactions during pre-commit */
4580 tgl@sss.pgh.pa.us 1246 : 7 : snprintf(sql, sizeof(sql), "RELEASE SAVEPOINT s%d", curlevel);
3013 rhaas@postgresql.org 1247 : 7 : entry->changing_xact_state = true;
1290 efujita@postgresql.o 1248 [ + + ]: 7 : if (entry->parallel_commit)
1249 : : {
1250 : 2 : do_sql_command_begin(entry->conn, sql);
1251 : 2 : pending_entries = lappend(pending_entries, entry);
1252 : 2 : continue;
1253 : : }
4562 tgl@sss.pgh.pa.us 1254 : 5 : do_sql_command(entry->conn, sql);
3013 rhaas@postgresql.org 1255 : 5 : entry->changing_xact_state = false;
1256 : : }
1257 : : else
1258 : : {
1259 : : /* Rollback all remote subtransactions during abort */
884 efujita@postgresql.o 1260 [ + + ]: 7 : if (entry->parallel_abort)
1261 : : {
1262 [ + - ]: 4 : if (pgfdw_abort_cleanup_begin(entry, false,
1263 : : &pending_entries,
1264 : : &cancel_requested))
1265 : 4 : continue;
1266 : : }
1267 : : else
1268 : 3 : pgfdw_abort_cleanup(entry, false);
1269 : : }
1270 : :
1271 : : /* OK, we're outta that level of subtransaction */
1290 1272 : 8 : pgfdw_reset_xact_state(entry, false);
1273 : : }
1274 : :
1275 : : /* If there are any pending connections, finish cleaning them up */
884 1276 [ + + - + ]: 15 : if (pending_entries || cancel_requested)
1277 : : {
1278 [ + + ]: 3 : if (event == SUBXACT_EVENT_PRE_COMMIT_SUB)
1279 : : {
1280 [ - + ]: 1 : Assert(cancel_requested == NIL);
1281 : 1 : pgfdw_finish_pre_subcommit_cleanup(pending_entries, curlevel);
1282 : : }
1283 : : else
1284 : : {
1285 [ - + ]: 2 : Assert(event == SUBXACT_EVENT_ABORT_SUB);
1286 : 2 : pgfdw_finish_abort_cleanup(pending_entries, cancel_requested,
1287 : : false);
1288 : : }
1289 : : }
1290 : : }
1291 : :
1292 : : /*
1293 : : * Connection invalidation callback function
1294 : : *
1295 : : * After a change to a pg_foreign_server or pg_user_mapping catalog entry,
1296 : : * close connections depending on that entry immediately if current transaction
1297 : : * has not used those connections yet. Otherwise, mark those connections as
1298 : : * invalid and then make pgfdw_xact_callback() close them at the end of current
1299 : : * transaction, since they cannot be closed in the midst of the transaction
1300 : : * using them. Closed connections will be remade at the next opportunity if
1301 : : * necessary.
1302 : : *
1303 : : * Although most cache invalidation callbacks blow away all the related stuff
1304 : : * regardless of the given hashvalue, connections are expensive enough that
1305 : : * it's worth trying to avoid that.
1306 : : *
1307 : : * NB: We could avoid unnecessary disconnection more strictly by examining
1308 : : * individual option values, but it seems too much effort for the gain.
1309 : : */
1310 : : static void
2969 tgl@sss.pgh.pa.us 1311 : 176 : pgfdw_inval_callback(Datum arg, int cacheid, uint32 hashvalue)
1312 : : {
1313 : : HASH_SEQ_STATUS scan;
1314 : : ConnCacheEntry *entry;
1315 : :
1316 [ + + - + ]: 176 : Assert(cacheid == FOREIGNSERVEROID || cacheid == USERMAPPINGOID);
1317 : :
1318 : : /* ConnectionHash must exist already, if we're registered */
1319 : 176 : hash_seq_init(&scan, ConnectionHash);
1320 [ + + ]: 1186 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
1321 : : {
1322 : : /* Ignore invalid entries */
1323 [ + + ]: 1010 : if (entry->conn == NULL)
1324 : 818 : continue;
1325 : :
1326 : : /* hashvalue == 0 means a cache reset, must clear all state */
1327 [ + - + + ]: 192 : if (hashvalue == 0 ||
1328 : 139 : (cacheid == FOREIGNSERVEROID &&
1329 [ + + + + ]: 192 : entry->server_hashvalue == hashvalue) ||
1330 : 53 : (cacheid == USERMAPPINGOID &&
1331 [ + + ]: 53 : entry->mapping_hashvalue == hashvalue))
1332 : : {
1333 : : /*
1334 : : * Close the connection immediately if it's not used yet in this
1335 : : * transaction. Otherwise mark it as invalid so that
1336 : : * pgfdw_xact_callback() can close it at the end of this
1337 : : * transaction.
1338 : : */
1713 fujii@postgresql.org 1339 [ + + ]: 55 : if (entry->xact_depth == 0)
1340 : : {
1341 [ - + ]: 52 : elog(DEBUG3, "discarding connection %p", entry->conn);
1342 : 52 : disconnect_pg_server(entry);
1343 : : }
1344 : : else
1345 : 3 : entry->invalidated = true;
1346 : : }
1347 : : }
2969 tgl@sss.pgh.pa.us 1348 : 176 : }
1349 : :
1350 : : /*
1351 : : * Raise an error if the given connection cache entry is marked as being
1352 : : * in the middle of an xact state change. This should be called at which no
1353 : : * such change is expected to be in progress; if one is found to be in
1354 : : * progress, it means that we aborted in the middle of a previous state change
1355 : : * and now don't know what the remote transaction state actually is.
1356 : : * Such connections can't safely be further used. Re-establishing the
1357 : : * connection would change the snapshot and roll back any writes already
1358 : : * performed, so that's not an option, either. Thus, we must abort.
1359 : : */
1360 : : static void
3013 rhaas@postgresql.org 1361 : 2912 : pgfdw_reject_incomplete_xact_state_change(ConnCacheEntry *entry)
1362 : : {
1363 : : ForeignServer *server;
1364 : :
1365 : : /* nothing to do for inactive entries and entries of sane state */
2969 tgl@sss.pgh.pa.us 1366 [ + + + - ]: 2912 : if (entry->conn == NULL || !entry->changing_xact_state)
3013 rhaas@postgresql.org 1367 : 2912 : return;
1368 : :
1369 : : /* make sure this entry is inactive */
2969 tgl@sss.pgh.pa.us 1370 :UBC 0 : disconnect_pg_server(entry);
1371 : :
1372 : : /* find server name to be shown in the message below */
1695 fujii@postgresql.org 1373 : 0 : server = GetForeignServer(entry->serverid);
1374 : :
3013 rhaas@postgresql.org 1375 [ # # ]: 0 : ereport(ERROR,
1376 : : (errcode(ERRCODE_CONNECTION_EXCEPTION),
1377 : : errmsg("connection to server \"%s\" was lost",
1378 : : server->servername)));
1379 : : }
1380 : :
1381 : : /*
1382 : : * Reset state to show we're out of a (sub)transaction.
1383 : : */
1384 : : static void
1290 efujita@postgresql.o 1385 :CBC 1303 : pgfdw_reset_xact_state(ConnCacheEntry *entry, bool toplevel)
1386 : : {
1387 [ + + ]: 1303 : if (toplevel)
1388 : : {
1389 : : /* Reset state to show we're out of a transaction */
1390 : 1289 : entry->xact_depth = 0;
1391 : :
1392 : : /*
1393 : : * If the connection isn't in a good idle state, it is marked as
1394 : : * invalid or keep_connections option of its server is disabled, then
1395 : : * discard it to recover. Next GetConnection will open a new
1396 : : * connection.
1397 : : */
1398 [ + + + - ]: 2577 : if (PQstatus(entry->conn) != CONNECTION_OK ||
1399 : 1288 : PQtransactionStatus(entry->conn) != PQTRANS_IDLE ||
1400 [ + - ]: 1288 : entry->changing_xact_state ||
1401 [ + + ]: 1288 : entry->invalidated ||
1402 [ + + ]: 1286 : !entry->keep_connections)
1403 : : {
1404 [ - + ]: 4 : elog(DEBUG3, "discarding connection %p", entry->conn);
1405 : 4 : disconnect_pg_server(entry);
1406 : : }
1407 : : }
1408 : : else
1409 : : {
1410 : : /* Reset state to show we're out of a subtransaction */
1411 : 14 : entry->xact_depth--;
1412 : : }
1413 : 1303 : }
1414 : :
1415 : : /*
1416 : : * Cancel the currently-in-progress query (whose query text we do not have)
1417 : : * and ignore the result. Returns true if we successfully cancel the query
1418 : : * and discard any pending result, and false if not.
1419 : : *
1420 : : * It's not a huge problem if we throw an ERROR here, but if we get into error
1421 : : * recursion trouble, we'll end up slamming the connection shut, which will
1422 : : * necessitate failing the entire toplevel transaction even if subtransactions
1423 : : * were used. Try to use WARNING where we can.
1424 : : *
1425 : : * XXX: if the query was one sent by fetch_more_data_begin(), we could get the
1426 : : * query text from the pendingAreq saved in the per-connection state, then
1427 : : * report the query using it.
1428 : : */
1429 : : static bool
3013 rhaas@postgresql.org 1430 : 2 : pgfdw_cancel_query(PGconn *conn)
1431 : : {
257 tgl@sss.pgh.pa.us 1432 : 2 : TimestampTz now = GetCurrentTimestamp();
1433 : : TimestampTz endtime;
1434 : : TimestampTz retrycanceltime;
1435 : :
1436 : : /*
1437 : : * If it takes too long to cancel the query and discard the result, assume
1438 : : * the connection is dead.
1439 : : */
1440 : 2 : endtime = TimestampTzPlusMilliseconds(now, CONNECTION_CLEANUP_TIMEOUT);
1441 : :
1442 : : /*
1443 : : * Also, lose patience and re-issue the cancel request after a little bit.
1444 : : * (This serves to close some race conditions.)
1445 : : */
1446 : 2 : retrycanceltime = TimestampTzPlusMilliseconds(now, RETRY_CANCEL_TIMEOUT);
1447 : :
527 alvherre@alvh.no-ip. 1448 [ - + ]: 2 : if (!pgfdw_cancel_query_begin(conn, endtime))
884 efujita@postgresql.o 1449 :UBC 0 : return false;
257 tgl@sss.pgh.pa.us 1450 :CBC 2 : return pgfdw_cancel_query_end(conn, endtime, retrycanceltime, false);
1451 : : }
1452 : :
1453 : : /*
1454 : : * Submit a cancel request to the given connection, waiting only until
1455 : : * the given time.
1456 : : *
1457 : : * We sleep interruptibly until we receive confirmation that the cancel
1458 : : * request has been accepted, and if it is, return true; if the timeout
1459 : : * lapses without that, or the request fails for whatever reason, return
1460 : : * false.
1461 : : */
1462 : : static bool
527 alvherre@alvh.no-ip. 1463 : 2 : pgfdw_cancel_query_begin(PGconn *conn, TimestampTz endtime)
1464 : : {
519 1465 : 2 : const char *errormsg = libpqsrv_cancel(conn, endtime);
1466 : :
527 1467 [ - + ]: 2 : if (errormsg != NULL)
527 alvherre@alvh.no-ip. 1468 [ # # ]:UBC 0 : ereport(WARNING,
1469 : : errcode(ERRCODE_CONNECTION_FAILURE),
1470 : : errmsg("could not send cancel request: %s", errormsg));
1471 : :
527 alvherre@alvh.no-ip. 1472 :CBC 2 : return errormsg == NULL;
1473 : : }
1474 : :
1475 : : static bool
257 tgl@sss.pgh.pa.us 1476 : 2 : pgfdw_cancel_query_end(PGconn *conn, TimestampTz endtime,
1477 : : TimestampTz retrycanceltime, bool consume_input)
1478 : : {
1479 : : PGresult *result;
1480 : : bool timed_out;
1481 : :
1482 : : /*
1483 : : * If requested, consume whatever data is available from the socket. (Note
1484 : : * that if all data is available, this allows pgfdw_get_cleanup_result to
1485 : : * call PQgetResult without forcing the overhead of WaitLatchOrSocket,
1486 : : * which would be large compared to the overhead of PQconsumeInput.)
1487 : : */
884 efujita@postgresql.o 1488 [ - + - - ]: 2 : if (consume_input && !PQconsumeInput(conn))
1489 : : {
884 efujita@postgresql.o 1490 [ # # ]:UBC 0 : ereport(WARNING,
1491 : : (errcode(ERRCODE_CONNECTION_FAILURE),
1492 : : errmsg("could not get result of cancel request: %s",
1493 : : pchomp(PQerrorMessage(conn)))));
1494 : 0 : return false;
1495 : : }
1496 : :
1497 : : /* Get and discard the result of the query. */
257 tgl@sss.pgh.pa.us 1498 [ - + ]:CBC 2 : if (pgfdw_get_cleanup_result(conn, endtime, retrycanceltime,
1499 : : &result, &timed_out))
1500 : : {
1368 fujii@postgresql.org 1501 [ # # ]:UBC 0 : if (timed_out)
1502 [ # # ]: 0 : ereport(WARNING,
1503 : : (errmsg("could not get result of cancel request due to timeout")));
1504 : : else
1505 [ # # ]: 0 : ereport(WARNING,
1506 : : (errcode(ERRCODE_CONNECTION_FAILURE),
1507 : : errmsg("could not get result of cancel request: %s",
1508 : : pchomp(PQerrorMessage(conn)))));
1509 : :
3013 rhaas@postgresql.org 1510 : 0 : return false;
1511 : : }
3013 rhaas@postgresql.org 1512 :CBC 2 : PQclear(result);
1513 : :
1514 : 2 : return true;
1515 : : }
1516 : :
1517 : : /*
1518 : : * Submit a query during (sub)abort cleanup and wait up to 30 seconds for the
1519 : : * result. If the query is executed without error, the return value is true.
1520 : : * If the query is executed successfully but returns an error, the return
1521 : : * value is true if and only if ignore_errors is set. If the query can't be
1522 : : * sent or times out, the return value is false.
1523 : : *
1524 : : * It's not a huge problem if we throw an ERROR here, but if we get into error
1525 : : * recursion trouble, we'll end up slamming the connection shut, which will
1526 : : * necessitate failing the entire toplevel transaction even if subtransactions
1527 : : * were used. Try to use WARNING where we can.
1528 : : */
1529 : : static bool
1530 : 75 : pgfdw_exec_cleanup_query(PGconn *conn, const char *query, bool ignore_errors)
1531 : : {
1532 : : TimestampTz endtime;
1533 : :
1534 : : /*
1535 : : * If it takes too long to execute a cleanup query, assume the connection
1536 : : * is dead. It's fairly likely that this is why we aborted in the first
1537 : : * place (e.g. statement timeout, user cancel), so the timeout shouldn't
1538 : : * be too long.
1539 : : */
884 efujita@postgresql.o 1540 : 75 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
1541 : : CONNECTION_CLEANUP_TIMEOUT);
1542 : :
1543 [ - + ]: 75 : if (!pgfdw_exec_cleanup_query_begin(conn, query))
884 efujita@postgresql.o 1544 :UBC 0 : return false;
884 efujita@postgresql.o 1545 :CBC 75 : return pgfdw_exec_cleanup_query_end(conn, query, endtime,
1546 : : false, ignore_errors);
1547 : : }
1548 : :
1549 : : static bool
1550 : 87 : pgfdw_exec_cleanup_query_begin(PGconn *conn, const char *query)
1551 : : {
520 1552 [ - + ]: 87 : Assert(query != NULL);
1553 : :
1554 : : /*
1555 : : * Submit a query. Since we don't use non-blocking mode, this also can
1556 : : * block. But its risk is relatively small, so we ignore that for now.
1557 : : */
3013 rhaas@postgresql.org 1558 [ - + ]: 87 : if (!PQsendQuery(conn, query))
1559 : : {
39 tgl@sss.pgh.pa.us 1560 :UNC 0 : pgfdw_report(WARNING, NULL, conn, query);
3013 rhaas@postgresql.org 1561 :UBC 0 : return false;
1562 : : }
1563 : :
884 efujita@postgresql.o 1564 :CBC 87 : return true;
1565 : : }
1566 : :
1567 : : static bool
1568 : 87 : pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query,
1569 : : TimestampTz endtime, bool consume_input,
1570 : : bool ignore_errors)
1571 : : {
1572 : : PGresult *result;
1573 : : bool timed_out;
1574 : :
520 1575 [ - + ]: 87 : Assert(query != NULL);
1576 : :
1577 : : /*
1578 : : * If requested, consume whatever data is available from the socket. (Note
1579 : : * that if all data is available, this allows pgfdw_get_cleanup_result to
1580 : : * call PQgetResult without forcing the overhead of WaitLatchOrSocket,
1581 : : * which would be large compared to the overhead of PQconsumeInput.)
1582 : : */
884 1583 [ + + - + ]: 87 : if (consume_input && !PQconsumeInput(conn))
1584 : : {
39 tgl@sss.pgh.pa.us 1585 :UNC 0 : pgfdw_report(WARNING, NULL, conn, query);
884 efujita@postgresql.o 1586 :UBC 0 : return false;
1587 : : }
1588 : :
1589 : : /* Get the result of the query. */
257 tgl@sss.pgh.pa.us 1590 [ - + ]:CBC 87 : if (pgfdw_get_cleanup_result(conn, endtime, endtime, &result, &timed_out))
1591 : : {
1368 fujii@postgresql.org 1592 [ # # ]:UBC 0 : if (timed_out)
1593 [ # # ]: 0 : ereport(WARNING,
1594 : : (errmsg("could not get query result due to timeout"),
1595 : : errcontext("remote SQL command: %s", query)));
1596 : : else
39 tgl@sss.pgh.pa.us 1597 :UNC 0 : pgfdw_report(WARNING, NULL, conn, query);
1598 : :
3013 rhaas@postgresql.org 1599 :UBC 0 : return false;
1600 : : }
1601 : :
1602 : : /* Issue a warning if not successful. */
3013 rhaas@postgresql.org 1603 [ - + ]:CBC 87 : if (PQresultStatus(result) != PGRES_COMMAND_OK)
1604 : : {
39 tgl@sss.pgh.pa.us 1605 :UNC 0 : pgfdw_report(WARNING, result, conn, query);
3013 rhaas@postgresql.org 1606 :UBC 0 : return ignore_errors;
1607 : : }
3005 tgl@sss.pgh.pa.us 1608 :CBC 87 : PQclear(result);
1609 : :
3013 rhaas@postgresql.org 1610 : 87 : return true;
1611 : : }
1612 : :
1613 : : /*
1614 : : * Get, during abort cleanup, the result of a query that is in progress.
1615 : : * This might be a query that is being interrupted by a cancel request or by
1616 : : * transaction abort, or it might be a query that was initiated as part of
1617 : : * transaction abort to get the remote side back to the appropriate state.
1618 : : *
1619 : : * endtime is the time at which we should give up and assume the remote side
1620 : : * is dead. retrycanceltime is the time at which we should issue a fresh
1621 : : * cancel request (pass the same value as endtime if this is not wanted).
1622 : : *
1623 : : * Returns true if the timeout expired or connection trouble occurred,
1624 : : * false otherwise. Sets *result except in case of a true result.
1625 : : * Sets *timed_out to true only when the timeout expired.
1626 : : */
1627 : : static bool
257 tgl@sss.pgh.pa.us 1628 : 89 : pgfdw_get_cleanup_result(PGconn *conn, TimestampTz endtime,
1629 : : TimestampTz retrycanceltime,
1630 : : PGresult **result,
1631 : : bool *timed_out)
1632 : : {
43 tgl@sss.pgh.pa.us 1633 :GNC 89 : bool failed = false;
1634 : 89 : PGresult *last_res = NULL;
1635 : 89 : int canceldelta = RETRY_CANCEL_TIMEOUT * 2;
1636 : :
257 tgl@sss.pgh.pa.us 1637 :CBC 89 : *result = NULL;
1368 fujii@postgresql.org 1638 : 89 : *timed_out = false;
1639 : : for (;;)
43 tgl@sss.pgh.pa.us 1640 :GIC 96 : {
1641 : : PGresult *res;
1642 : :
43 tgl@sss.pgh.pa.us 1643 [ + + ]:GNC 267 : while (PQisBusy(conn))
3013 rhaas@postgresql.org 1644 :ECB (96) : {
1645 : : int wc;
43 tgl@sss.pgh.pa.us 1646 :GNC 82 : TimestampTz now = GetCurrentTimestamp();
1647 : : long cur_timeout;
1648 : :
1649 : : /* If timeout has expired, give up. */
1650 [ - + ]: 82 : if (now >= endtime)
1651 : : {
43 tgl@sss.pgh.pa.us 1652 :UNC 0 : *timed_out = true;
1653 : 0 : failed = true;
1654 : 0 : goto exit;
1655 : : }
1656 : :
1657 : : /* If we need to re-issue the cancel request, do that. */
43 tgl@sss.pgh.pa.us 1658 [ - + ]:GNC 82 : if (now >= retrycanceltime)
1659 : : {
1660 : : /* We ignore failure to issue the repeated request. */
43 tgl@sss.pgh.pa.us 1661 :UNC 0 : (void) libpqsrv_cancel(conn, endtime);
1662 : :
1663 : : /* Recompute "now" in case that took measurable time. */
1664 : 0 : now = GetCurrentTimestamp();
1665 : :
1666 : : /* Adjust re-cancel timeout in increasing steps. */
1667 : 0 : retrycanceltime = TimestampTzPlusMilliseconds(now,
1668 : : canceldelta);
1669 : 0 : canceldelta += canceldelta;
1670 : : }
1671 : :
1672 : : /* If timeout has expired, give up, else get sleep time. */
43 tgl@sss.pgh.pa.us 1673 :GNC 82 : cur_timeout = TimestampDifferenceMilliseconds(now,
1674 : : Min(endtime,
1675 : : retrycanceltime));
1676 [ - + ]: 82 : if (cur_timeout <= 0)
1677 : : {
43 tgl@sss.pgh.pa.us 1678 :UNC 0 : *timed_out = true;
1679 : 0 : failed = true;
1680 : 0 : goto exit;
1681 : : }
1682 : :
1683 : : /* first time, allocate or get the custom wait event */
43 tgl@sss.pgh.pa.us 1684 [ + + ]:GNC 82 : if (pgfdw_we_cleanup_result == 0)
1685 : 2 : pgfdw_we_cleanup_result = WaitEventExtensionNew("PostgresFdwCleanupResult");
1686 : :
1687 : : /* Sleep until there's something to do */
1688 : 82 : wc = WaitLatchOrSocket(MyLatch,
1689 : : WL_LATCH_SET | WL_SOCKET_READABLE |
1690 : : WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
1691 : : PQsocket(conn),
1692 : : cur_timeout, pgfdw_we_cleanup_result);
1693 : 82 : ResetLatch(MyLatch);
1694 : :
1695 [ - + ]: 82 : CHECK_FOR_INTERRUPTS();
1696 : :
1697 : : /* Data available in socket? */
1698 [ + - ]: 82 : if (wc & WL_SOCKET_READABLE)
1699 : : {
1700 [ - + ]: 82 : if (!PQconsumeInput(conn))
1701 : : {
1702 : : /* connection trouble */
43 tgl@sss.pgh.pa.us 1703 :UNC 0 : failed = true;
1704 : 0 : goto exit;
1705 : : }
1706 : : }
1707 : : }
1708 : :
43 tgl@sss.pgh.pa.us 1709 :GNC 185 : res = PQgetResult(conn);
1710 [ + + ]: 185 : if (res == NULL)
1711 : 89 : break; /* query is complete */
1712 : :
43 tgl@sss.pgh.pa.us 1713 :GBC 96 : PQclear(last_res);
43 tgl@sss.pgh.pa.us 1714 :GNC 96 : last_res = res;
1715 : : }
1716 : 89 : exit:
1368 fujii@postgresql.org 1717 [ - + ]:CBC 89 : if (failed)
3005 tgl@sss.pgh.pa.us 1718 :UBC 0 : PQclear(last_res);
1719 : : else
3005 tgl@sss.pgh.pa.us 1720 :CBC 89 : *result = last_res;
1368 fujii@postgresql.org 1721 : 89 : return failed;
1722 : : }
1723 : :
1724 : : /*
1725 : : * Abort remote transaction or subtransaction.
1726 : : *
1727 : : * "toplevel" should be set to true if toplevel (main) transaction is
1728 : : * rollbacked, false otherwise.
1729 : : *
1730 : : * Set entry->changing_xact_state to false on success, true on failure.
1731 : : */
1732 : : static void
1261 efujita@postgresql.o 1733 : 51 : pgfdw_abort_cleanup(ConnCacheEntry *entry, bool toplevel)
1734 : : {
1735 : : char sql[100];
1736 : :
1737 : : /*
1738 : : * Don't try to clean up the connection if we're already in error
1739 : : * recursion trouble.
1740 : : */
1445 fujii@postgresql.org 1741 [ - + ]: 51 : if (in_error_recursion_trouble())
1445 fujii@postgresql.org 1742 :UBC 0 : entry->changing_xact_state = true;
1743 : :
1744 : : /*
1745 : : * If connection is already unsalvageable, don't touch it further.
1746 : : */
1445 fujii@postgresql.org 1747 [ + + ]:CBC 51 : if (entry->changing_xact_state)
1748 : 1 : return;
1749 : :
1750 : : /*
1751 : : * Mark this connection as in the process of changing transaction state.
1752 : : */
1753 : 50 : entry->changing_xact_state = true;
1754 : :
1755 : : /* Assume we might have lost track of prepared statements */
1756 : 50 : entry->have_error = true;
1757 : :
1758 : : /*
1759 : : * If a command has been submitted to the remote server by using an
1760 : : * asynchronous execution function, the command might not have yet
1761 : : * completed. Check to see if a command is still being processed by the
1762 : : * remote server, and if so, request cancellation of the command.
1763 : : */
1764 [ + + ]: 50 : if (PQtransactionStatus(entry->conn) == PQTRANS_ACTIVE &&
1765 [ - + ]: 2 : !pgfdw_cancel_query(entry->conn))
1445 fujii@postgresql.org 1766 :UBC 0 : return; /* Unable to cancel running query */
1767 : :
884 efujita@postgresql.o 1768 [ + + ]:CBC 50 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
1445 fujii@postgresql.org 1769 [ - + ]: 50 : if (!pgfdw_exec_cleanup_query(entry->conn, sql, false))
1261 efujita@postgresql.o 1770 :UBC 0 : return; /* Unable to abort remote (sub)transaction */
1771 : :
1445 fujii@postgresql.org 1772 [ + + ]:CBC 50 : if (toplevel)
1773 : : {
1774 [ + + + - ]: 47 : if (entry->have_prep_stmt && entry->have_error &&
1775 [ - + ]: 25 : !pgfdw_exec_cleanup_query(entry->conn,
1776 : : "DEALLOCATE ALL",
1777 : : true))
1445 fujii@postgresql.org 1778 :UBC 0 : return; /* Trouble clearing prepared statements */
1779 : :
1445 fujii@postgresql.org 1780 :CBC 47 : entry->have_prep_stmt = false;
1781 : 47 : entry->have_error = false;
1782 : : }
1783 : :
1784 : : /*
1785 : : * If pendingAreq of the per-connection state is not NULL, it means that
1786 : : * an asynchronous fetch begun by fetch_more_data_begin() was not done
1787 : : * successfully and thus the per-connection state was not reset in
1788 : : * fetch_more_data(); in that case reset the per-connection state here.
1789 : : */
1324 efujita@postgresql.o 1790 [ + + ]: 50 : if (entry->state.pendingAreq)
1791 : 1 : memset(&entry->state, 0, sizeof(entry->state));
1792 : :
1793 : : /* Disarm changing_xact_state if it all worked */
1445 fujii@postgresql.org 1794 : 50 : entry->changing_xact_state = false;
1795 : : }
1796 : :
1797 : : /*
1798 : : * Like pgfdw_abort_cleanup, submit an abort command or cancel request, but
1799 : : * don't wait for the result.
1800 : : *
1801 : : * Returns true if the abort command or cancel request is successfully issued,
1802 : : * false otherwise. If the abort command is successfully issued, the given
1803 : : * connection cache entry is appended to *pending_entries. Otherwise, if the
1804 : : * cancel request is successfully issued, it is appended to *cancel_requested.
1805 : : */
1806 : : static bool
884 efujita@postgresql.o 1807 : 8 : pgfdw_abort_cleanup_begin(ConnCacheEntry *entry, bool toplevel,
1808 : : List **pending_entries, List **cancel_requested)
1809 : : {
1810 : : /*
1811 : : * Don't try to clean up the connection if we're already in error
1812 : : * recursion trouble.
1813 : : */
1814 [ - + ]: 8 : if (in_error_recursion_trouble())
884 efujita@postgresql.o 1815 :UBC 0 : entry->changing_xact_state = true;
1816 : :
1817 : : /*
1818 : : * If connection is already unsalvageable, don't touch it further.
1819 : : */
884 efujita@postgresql.o 1820 [ - + ]:CBC 8 : if (entry->changing_xact_state)
884 efujita@postgresql.o 1821 :UBC 0 : return false;
1822 : :
1823 : : /*
1824 : : * Mark this connection as in the process of changing transaction state.
1825 : : */
884 efujita@postgresql.o 1826 :CBC 8 : entry->changing_xact_state = true;
1827 : :
1828 : : /* Assume we might have lost track of prepared statements */
1829 : 8 : entry->have_error = true;
1830 : :
1831 : : /*
1832 : : * If a command has been submitted to the remote server by using an
1833 : : * asynchronous execution function, the command might not have yet
1834 : : * completed. Check to see if a command is still being processed by the
1835 : : * remote server, and if so, request cancellation of the command.
1836 : : */
1837 [ - + ]: 8 : if (PQtransactionStatus(entry->conn) == PQTRANS_ACTIVE)
1838 : : {
1839 : : TimestampTz endtime;
1840 : :
527 alvherre@alvh.no-ip. 1841 :UBC 0 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
1842 : : CONNECTION_CLEANUP_TIMEOUT);
1843 [ # # ]: 0 : if (!pgfdw_cancel_query_begin(entry->conn, endtime))
884 efujita@postgresql.o 1844 : 0 : return false; /* Unable to cancel running query */
1845 : 0 : *cancel_requested = lappend(*cancel_requested, entry);
1846 : : }
1847 : : else
1848 : : {
1849 : : char sql[100];
1850 : :
884 efujita@postgresql.o 1851 [ + + ]:CBC 8 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
1852 [ - + ]: 8 : if (!pgfdw_exec_cleanup_query_begin(entry->conn, sql))
884 efujita@postgresql.o 1853 :UBC 0 : return false; /* Unable to abort remote transaction */
884 efujita@postgresql.o 1854 :CBC 8 : *pending_entries = lappend(*pending_entries, entry);
1855 : : }
1856 : :
1857 : 8 : return true;
1858 : : }
1859 : :
1860 : : /*
1861 : : * Finish pre-commit cleanup of connections on each of which we've sent a
1862 : : * COMMIT command to the remote server.
1863 : : */
1864 : : static void
1290 1865 : 13 : pgfdw_finish_pre_commit_cleanup(List *pending_entries)
1866 : : {
1867 : : ConnCacheEntry *entry;
1868 : 13 : List *pending_deallocs = NIL;
1869 : : ListCell *lc;
1870 : :
1871 [ - + ]: 13 : Assert(pending_entries);
1872 : :
1873 : : /*
1874 : : * Get the result of the COMMIT command for each of the pending entries
1875 : : */
1876 [ + - + + : 29 : foreach(lc, pending_entries)
+ + ]
1877 : : {
1878 : 16 : entry = (ConnCacheEntry *) lfirst(lc);
1879 : :
1880 [ - + ]: 16 : Assert(entry->changing_xact_state);
1881 : :
1882 : : /*
1883 : : * We might already have received the result on the socket, so pass
1884 : : * consume_input=true to try to consume it first
1885 : : */
1886 : 16 : do_sql_command_end(entry->conn, "COMMIT TRANSACTION", true);
1887 : 16 : entry->changing_xact_state = false;
1888 : :
1889 : : /* Do a DEALLOCATE ALL in parallel if needed */
1890 [ + + + + ]: 16 : if (entry->have_prep_stmt && entry->have_error)
1891 : : {
1892 : : /* Ignore errors (see notes in pgfdw_xact_callback) */
1893 [ + - ]: 2 : if (PQsendQuery(entry->conn, "DEALLOCATE ALL"))
1894 : : {
1895 : 2 : pending_deallocs = lappend(pending_deallocs, entry);
1896 : 2 : continue;
1897 : : }
1898 : : }
1899 : 14 : entry->have_prep_stmt = false;
1900 : 14 : entry->have_error = false;
1901 : :
1902 : 14 : pgfdw_reset_xact_state(entry, true);
1903 : : }
1904 : :
1905 : : /* No further work if no pending entries */
1906 [ + + ]: 13 : if (!pending_deallocs)
1907 : 12 : return;
1908 : :
1909 : : /*
1910 : : * Get the result of the DEALLOCATE command for each of the pending
1911 : : * entries
1912 : : */
1913 [ + - + + : 3 : foreach(lc, pending_deallocs)
+ + ]
1914 : : {
1915 : : PGresult *res;
1916 : :
1917 : 2 : entry = (ConnCacheEntry *) lfirst(lc);
1918 : :
1919 : : /* Ignore errors (see notes in pgfdw_xact_callback) */
1920 [ + + ]: 4 : while ((res = PQgetResult(entry->conn)) != NULL)
1921 : : {
1922 : 2 : PQclear(res);
1923 : : /* Stop if the connection is lost (else we'll loop infinitely) */
1924 [ - + ]: 2 : if (PQstatus(entry->conn) == CONNECTION_BAD)
1290 efujita@postgresql.o 1925 :UBC 0 : break;
1926 : : }
1290 efujita@postgresql.o 1927 :CBC 2 : entry->have_prep_stmt = false;
1928 : 2 : entry->have_error = false;
1929 : :
1930 : 2 : pgfdw_reset_xact_state(entry, true);
1931 : : }
1932 : : }
1933 : :
1934 : : /*
1935 : : * Finish pre-subcommit cleanup of connections on each of which we've sent a
1936 : : * RELEASE command to the remote server.
1937 : : */
1938 : : static void
1939 : 1 : pgfdw_finish_pre_subcommit_cleanup(List *pending_entries, int curlevel)
1940 : : {
1941 : : ConnCacheEntry *entry;
1942 : : char sql[100];
1943 : : ListCell *lc;
1944 : :
1945 [ - + ]: 1 : Assert(pending_entries);
1946 : :
1947 : : /*
1948 : : * Get the result of the RELEASE command for each of the pending entries
1949 : : */
1950 : 1 : snprintf(sql, sizeof(sql), "RELEASE SAVEPOINT s%d", curlevel);
1951 [ + - + + : 3 : foreach(lc, pending_entries)
+ + ]
1952 : : {
1953 : 2 : entry = (ConnCacheEntry *) lfirst(lc);
1954 : :
1955 [ - + ]: 2 : Assert(entry->changing_xact_state);
1956 : :
1957 : : /*
1958 : : * We might already have received the result on the socket, so pass
1959 : : * consume_input=true to try to consume it first
1960 : : */
1961 : 2 : do_sql_command_end(entry->conn, sql, true);
1962 : 2 : entry->changing_xact_state = false;
1963 : :
1964 : 2 : pgfdw_reset_xact_state(entry, false);
1965 : : }
1966 : 1 : }
1967 : :
1968 : : /*
1969 : : * Finish abort cleanup of connections on each of which we've sent an abort
1970 : : * command or cancel request to the remote server.
1971 : : */
1972 : : static void
884 1973 : 4 : pgfdw_finish_abort_cleanup(List *pending_entries, List *cancel_requested,
1974 : : bool toplevel)
1975 : : {
1976 : 4 : List *pending_deallocs = NIL;
1977 : : ListCell *lc;
1978 : :
1979 : : /*
1980 : : * For each of the pending cancel requests (if any), get and discard the
1981 : : * result of the query, and submit an abort command to the remote server.
1982 : : */
1983 [ - + ]: 4 : if (cancel_requested)
1984 : : {
884 efujita@postgresql.o 1985 [ # # # # :UBC 0 : foreach(lc, cancel_requested)
# # ]
1986 : : {
1987 : 0 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
257 tgl@sss.pgh.pa.us 1988 : 0 : TimestampTz now = GetCurrentTimestamp();
1989 : : TimestampTz endtime;
1990 : : TimestampTz retrycanceltime;
1991 : : char sql[100];
1992 : :
884 efujita@postgresql.o 1993 [ # # ]: 0 : Assert(entry->changing_xact_state);
1994 : :
1995 : : /*
1996 : : * Set end time. You might think we should do this before issuing
1997 : : * cancel request like in normal mode, but that is problematic,
1998 : : * because if, for example, it took longer than 30 seconds to
1999 : : * process the first few entries in the cancel_requested list, it
2000 : : * would cause a timeout error when processing each of the
2001 : : * remaining entries in the list, leading to slamming that entry's
2002 : : * connection shut.
2003 : : */
257 tgl@sss.pgh.pa.us 2004 : 0 : endtime = TimestampTzPlusMilliseconds(now,
2005 : : CONNECTION_CLEANUP_TIMEOUT);
2006 : 0 : retrycanceltime = TimestampTzPlusMilliseconds(now,
2007 : : RETRY_CANCEL_TIMEOUT);
2008 : :
2009 [ # # ]: 0 : if (!pgfdw_cancel_query_end(entry->conn, endtime,
2010 : : retrycanceltime, true))
2011 : : {
2012 : : /* Unable to cancel running query */
884 efujita@postgresql.o 2013 : 0 : pgfdw_reset_xact_state(entry, toplevel);
2014 : 0 : continue;
2015 : : }
2016 : :
2017 : : /* Send an abort command in parallel if needed */
2018 [ # # ]: 0 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
2019 [ # # ]: 0 : if (!pgfdw_exec_cleanup_query_begin(entry->conn, sql))
2020 : : {
2021 : : /* Unable to abort remote (sub)transaction */
2022 : 0 : pgfdw_reset_xact_state(entry, toplevel);
2023 : : }
2024 : : else
2025 : 0 : pending_entries = lappend(pending_entries, entry);
2026 : : }
2027 : : }
2028 : :
2029 : : /* No further work if no pending entries */
884 efujita@postgresql.o 2030 [ - + ]:CBC 4 : if (!pending_entries)
884 efujita@postgresql.o 2031 :UBC 0 : return;
2032 : :
2033 : : /*
2034 : : * Get the result of the abort command for each of the pending entries
2035 : : */
884 efujita@postgresql.o 2036 [ + - + + :CBC 12 : foreach(lc, pending_entries)
+ + ]
2037 : : {
2038 : 8 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
2039 : : TimestampTz endtime;
2040 : : char sql[100];
2041 : :
2042 [ - + ]: 8 : Assert(entry->changing_xact_state);
2043 : :
2044 : : /*
2045 : : * Set end time. We do this now, not before issuing the command like
2046 : : * in normal mode, for the same reason as for the cancel_requested
2047 : : * entries.
2048 : : */
2049 : 8 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
2050 : : CONNECTION_CLEANUP_TIMEOUT);
2051 : :
2052 [ + + ]: 8 : CONSTRUCT_ABORT_COMMAND(sql, entry, toplevel);
2053 [ - + ]: 8 : if (!pgfdw_exec_cleanup_query_end(entry->conn, sql, endtime,
2054 : : true, false))
2055 : : {
2056 : : /* Unable to abort remote (sub)transaction */
884 efujita@postgresql.o 2057 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
884 efujita@postgresql.o 2058 :CBC 4 : continue;
2059 : : }
2060 : :
2061 [ + + ]: 8 : if (toplevel)
2062 : : {
2063 : : /* Do a DEALLOCATE ALL in parallel if needed */
2064 [ + - + - ]: 4 : if (entry->have_prep_stmt && entry->have_error)
2065 : : {
2066 [ - + ]: 4 : if (!pgfdw_exec_cleanup_query_begin(entry->conn,
2067 : : "DEALLOCATE ALL"))
2068 : : {
2069 : : /* Trouble clearing prepared statements */
884 efujita@postgresql.o 2070 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
2071 : : }
2072 : : else
884 efujita@postgresql.o 2073 :CBC 4 : pending_deallocs = lappend(pending_deallocs, entry);
2074 : 4 : continue;
2075 : : }
884 efujita@postgresql.o 2076 :UBC 0 : entry->have_prep_stmt = false;
2077 : 0 : entry->have_error = false;
2078 : : }
2079 : :
2080 : : /* Reset the per-connection state if needed */
884 efujita@postgresql.o 2081 [ - + ]:CBC 4 : if (entry->state.pendingAreq)
884 efujita@postgresql.o 2082 :UBC 0 : memset(&entry->state, 0, sizeof(entry->state));
2083 : :
2084 : : /* We're done with this entry; unset the changing_xact_state flag */
884 efujita@postgresql.o 2085 :CBC 4 : entry->changing_xact_state = false;
2086 : 4 : pgfdw_reset_xact_state(entry, toplevel);
2087 : : }
2088 : :
2089 : : /* No further work if no pending entries */
2090 [ + + ]: 4 : if (!pending_deallocs)
2091 : 2 : return;
2092 [ - + ]: 2 : Assert(toplevel);
2093 : :
2094 : : /*
2095 : : * Get the result of the DEALLOCATE command for each of the pending
2096 : : * entries
2097 : : */
2098 [ + - + + : 6 : foreach(lc, pending_deallocs)
+ + ]
2099 : : {
2100 : 4 : ConnCacheEntry *entry = (ConnCacheEntry *) lfirst(lc);
2101 : : TimestampTz endtime;
2102 : :
2103 [ - + ]: 4 : Assert(entry->changing_xact_state);
2104 [ - + ]: 4 : Assert(entry->have_prep_stmt);
2105 [ - + ]: 4 : Assert(entry->have_error);
2106 : :
2107 : : /*
2108 : : * Set end time. We do this now, not before issuing the command like
2109 : : * in normal mode, for the same reason as for the cancel_requested
2110 : : * entries.
2111 : : */
2112 : 4 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
2113 : : CONNECTION_CLEANUP_TIMEOUT);
2114 : :
2115 [ - + ]: 4 : if (!pgfdw_exec_cleanup_query_end(entry->conn, "DEALLOCATE ALL",
2116 : : endtime, true, true))
2117 : : {
2118 : : /* Trouble clearing prepared statements */
884 efujita@postgresql.o 2119 :UBC 0 : pgfdw_reset_xact_state(entry, toplevel);
2120 : 0 : continue;
2121 : : }
884 efujita@postgresql.o 2122 :CBC 4 : entry->have_prep_stmt = false;
2123 : 4 : entry->have_error = false;
2124 : :
2125 : : /* Reset the per-connection state if needed */
2126 [ - + ]: 4 : if (entry->state.pendingAreq)
884 efujita@postgresql.o 2127 :UBC 0 : memset(&entry->state, 0, sizeof(entry->state));
2128 : :
2129 : : /* We're done with this entry; unset the changing_xact_state flag */
884 efujita@postgresql.o 2130 :CBC 4 : entry->changing_xact_state = false;
2131 : 4 : pgfdw_reset_xact_state(entry, toplevel);
2132 : : }
2133 : : }
2134 : :
2135 : : /* Number of output arguments (columns) for various API versions */
2136 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_1 2
2137 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_2 6
2138 : : #define POSTGRES_FDW_GET_CONNECTIONS_COLS 6 /* maximum of above */
2139 : :
2140 : : /*
2141 : : * Internal function used by postgres_fdw_get_connections variants.
2142 : : *
2143 : : * For API version 1.1, this function takes no input parameter and
2144 : : * returns a set of records with the following values:
2145 : : *
2146 : : * - server_name - server name of active connection. In case the foreign server
2147 : : * is dropped but still the connection is active, then the server name will
2148 : : * be NULL in output.
2149 : : * - valid - true/false representing whether the connection is valid or not.
2150 : : * Note that connections can become invalid in pgfdw_inval_callback.
2151 : : *
2152 : : * For API version 1.2 and later, this function takes an input parameter
2153 : : * to check a connection status and returns the following
2154 : : * additional values along with the four values from version 1.1:
2155 : : *
2156 : : * - user_name - the local user name of the active connection. In case the
2157 : : * user mapping is dropped but the connection is still active, then the
2158 : : * user name will be NULL in the output.
2159 : : * - used_in_xact - true if the connection is used in the current transaction.
2160 : : * - closed - true if the connection is closed.
2161 : : * - remote_backend_pid - process ID of the remote backend, on the foreign
2162 : : * server, handling the connection.
2163 : : *
2164 : : * No records are returned when there are no cached connections at all.
2165 : : */
2166 : : static void
407 fujii@postgresql.org 2167 : 13 : postgres_fdw_get_connections_internal(FunctionCallInfo fcinfo,
2168 : : enum pgfdwVersion api_version)
2169 : : {
1692 2170 : 13 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
2171 : : HASH_SEQ_STATUS scan;
2172 : : ConnCacheEntry *entry;
2173 : :
1054 michael@paquier.xyz 2174 : 13 : InitMaterializedSRF(fcinfo, 0);
2175 : :
2176 : : /* If cache doesn't exist, we return no records */
1692 fujii@postgresql.org 2177 [ - + ]: 13 : if (!ConnectionHash)
407 fujii@postgresql.org 2178 :UBC 0 : return;
2179 : :
2180 : : /* Check we have the expected number of output arguments */
407 fujii@postgresql.org 2181 [ - + - ]:CBC 13 : switch (rsinfo->setDesc->natts)
2182 : : {
407 fujii@postgresql.org 2183 :UBC 0 : case POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_1:
2184 [ # # ]: 0 : if (api_version != PGFDW_V1_1)
2185 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
2186 : 0 : break;
407 fujii@postgresql.org 2187 :CBC 13 : case POSTGRES_FDW_GET_CONNECTIONS_COLS_V1_2:
2188 [ - + ]: 13 : if (api_version != PGFDW_V1_2)
407 fujii@postgresql.org 2189 [ # # ]:UBC 0 : elog(ERROR, "incorrect number of output arguments");
407 fujii@postgresql.org 2190 :CBC 13 : break;
407 fujii@postgresql.org 2191 :UBC 0 : default:
2192 [ # # ]: 0 : elog(ERROR, "incorrect number of output arguments");
2193 : : }
2194 : :
1692 fujii@postgresql.org 2195 :CBC 13 : hash_seq_init(&scan, ConnectionHash);
2196 [ + + ]: 113 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
2197 : : {
2198 : : ForeignServer *server;
1148 peter@eisentraut.org 2199 : 100 : Datum values[POSTGRES_FDW_GET_CONNECTIONS_COLS] = {0};
2200 : 100 : bool nulls[POSTGRES_FDW_GET_CONNECTIONS_COLS] = {0};
353 fujii@postgresql.org 2201 : 100 : int i = 0;
2202 : :
2203 : : /* We only look for open remote connections */
1692 2204 [ + + ]: 100 : if (!entry->conn)
2205 : 87 : continue;
2206 : :
2207 : 13 : server = GetForeignServerExtended(entry->serverid, FSV_MISSING_OK);
2208 : :
2209 : : /*
2210 : : * The foreign server may have been dropped in current explicit
2211 : : * transaction. It is not possible to drop the server from another
2212 : : * session when the connection associated with it is in use in the
2213 : : * current transaction, if tried so, the drop query in another session
2214 : : * blocks until the current transaction finishes.
2215 : : *
2216 : : * Even though the server is dropped in the current transaction, the
2217 : : * cache can still have associated active connection entry, say we
2218 : : * call such connections dangling. Since we can not fetch the server
2219 : : * name from system catalogs for dangling connections, instead we show
2220 : : * NULL value for server name in output.
2221 : : *
2222 : : * We could have done better by storing the server name in the cache
2223 : : * entry instead of server oid so that it could be used in the output.
2224 : : * But the server name in each cache entry requires 64 bytes of
2225 : : * memory, which is huge, when there are many cached connections and
2226 : : * the use case i.e. dropping the foreign server within the explicit
2227 : : * current transaction seems rare. So, we chose to show NULL value for
2228 : : * server name in output.
2229 : : *
2230 : : * Such dangling connections get closed either in next use or at the
2231 : : * end of current explicit transaction in pgfdw_xact_callback.
2232 : : */
2233 [ + + ]: 13 : if (!server)
2234 : : {
2235 : : /*
2236 : : * If the server has been dropped in the current explicit
2237 : : * transaction, then this entry would have been invalidated in
2238 : : * pgfdw_inval_callback at the end of drop server command. Note
2239 : : * that this connection would not have been closed in
2240 : : * pgfdw_inval_callback because it is still being used in the
2241 : : * current explicit transaction. So, assert that here.
2242 : : */
2243 [ + - + - : 1 : Assert(entry->conn && entry->xact_depth > 0 && entry->invalidated);
- + ]
2244 : :
2245 : : /* Show null, if no server name was found */
353 2246 : 1 : nulls[i++] = true;
2247 : : }
2248 : : else
2249 : 12 : values[i++] = CStringGetTextDatum(server->servername);
2250 : :
2251 [ + - ]: 13 : if (api_version >= PGFDW_V1_2)
2252 : : {
2253 : : HeapTuple tp;
2254 : :
2255 : : /* Use the system cache to obtain the user mapping */
2256 : 13 : tp = SearchSysCache1(USERMAPPINGOID, ObjectIdGetDatum(entry->key));
2257 : :
2258 : : /*
2259 : : * Just like in the foreign server case, user mappings can also be
2260 : : * dropped in the current explicit transaction. Therefore, the
2261 : : * similar check as in the server case is required.
2262 : : */
2263 [ + + ]: 13 : if (!HeapTupleIsValid(tp))
2264 : : {
2265 : : /*
2266 : : * If we reach here, this entry must have been invalidated in
2267 : : * pgfdw_inval_callback, same as in the server case.
2268 : : */
2269 [ + - + - : 1 : Assert(entry->conn && entry->xact_depth > 0 &&
- + ]
2270 : : entry->invalidated);
2271 : :
2272 : 1 : nulls[i++] = true;
2273 : : }
2274 : : else
2275 : : {
2276 : : Oid userid;
2277 : :
2278 : 12 : userid = ((Form_pg_user_mapping) GETSTRUCT(tp))->umuser;
2279 [ + + ]: 12 : values[i++] = CStringGetTextDatum(MappingUserName(userid));
2280 : 12 : ReleaseSysCache(tp);
2281 : : }
2282 : : }
2283 : :
2284 : 13 : values[i++] = BoolGetDatum(!entry->invalidated);
2285 : :
407 2286 [ + - ]: 13 : if (api_version >= PGFDW_V1_2)
2287 : : {
2288 : 13 : bool check_conn = PG_GETARG_BOOL(0);
2289 : :
2290 : : /* Is this connection used in the current transaction? */
353 2291 : 13 : values[i++] = BoolGetDatum(entry->xact_depth > 0);
2292 : :
2293 : : /*
2294 : : * If a connection status check is requested and supported, return
2295 : : * whether the connection is closed. Otherwise, return NULL.
2296 : : */
407 2297 [ + + + - ]: 13 : if (check_conn && pgfdw_conn_checkable())
353 2298 : 2 : values[i++] = BoolGetDatum(pgfdw_conn_check(entry->conn) != 0);
2299 : : else
2300 : 11 : nulls[i++] = true;
2301 : :
2302 : : /* Return process ID of remote backend */
187 2303 : 13 : values[i++] = Int32GetDatum(PQbackendPID(entry->conn));
2304 : : }
2305 : :
1278 michael@paquier.xyz 2306 : 13 : tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
2307 : : }
2308 : : }
2309 : :
2310 : : /*
2311 : : * List active foreign server connections.
2312 : : *
2313 : : * The SQL API of this function has changed multiple times, and will likely
2314 : : * do so again in future. To support the case where a newer version of this
2315 : : * loadable module is being used with an old SQL declaration of the function,
2316 : : * we continue to support the older API versions.
2317 : : */
2318 : : Datum
407 fujii@postgresql.org 2319 : 13 : postgres_fdw_get_connections_1_2(PG_FUNCTION_ARGS)
2320 : : {
2321 : 13 : postgres_fdw_get_connections_internal(fcinfo, PGFDW_V1_2);
2322 : :
2323 : 13 : PG_RETURN_VOID();
2324 : : }
2325 : :
2326 : : Datum
407 fujii@postgresql.org 2327 :UBC 0 : postgres_fdw_get_connections(PG_FUNCTION_ARGS)
2328 : : {
2329 : 0 : postgres_fdw_get_connections_internal(fcinfo, PGFDW_V1_1);
2330 : :
1692 2331 : 0 : PG_RETURN_VOID();
2332 : : }
2333 : :
2334 : : /*
2335 : : * Disconnect the specified cached connections.
2336 : : *
2337 : : * This function discards the open connections that are established by
2338 : : * postgres_fdw from the local session to the foreign server with
2339 : : * the given name. Note that there can be multiple connections to
2340 : : * the given server using different user mappings. If the connections
2341 : : * are used in the current local transaction, they are not disconnected
2342 : : * and warning messages are reported. This function returns true
2343 : : * if it disconnects at least one connection, otherwise false. If no
2344 : : * foreign server with the given name is found, an error is reported.
2345 : : */
2346 : : Datum
1684 fujii@postgresql.org 2347 :CBC 4 : postgres_fdw_disconnect(PG_FUNCTION_ARGS)
2348 : : {
2349 : : ForeignServer *server;
2350 : : char *servername;
2351 : :
2352 : 4 : servername = text_to_cstring(PG_GETARG_TEXT_PP(0));
2353 : 4 : server = GetForeignServerByName(servername, false);
2354 : :
2355 : 3 : PG_RETURN_BOOL(disconnect_cached_connections(server->serverid));
2356 : : }
2357 : :
2358 : : /*
2359 : : * Disconnect all the cached connections.
2360 : : *
2361 : : * This function discards all the open connections that are established by
2362 : : * postgres_fdw from the local session to the foreign servers.
2363 : : * If the connections are used in the current local transaction, they are
2364 : : * not disconnected and warning messages are reported. This function
2365 : : * returns true if it disconnects at least one connection, otherwise false.
2366 : : */
2367 : : Datum
2368 : 5 : postgres_fdw_disconnect_all(PG_FUNCTION_ARGS)
2369 : : {
2370 : 5 : PG_RETURN_BOOL(disconnect_cached_connections(InvalidOid));
2371 : : }
2372 : :
2373 : : /*
2374 : : * Workhorse to disconnect cached connections.
2375 : : *
2376 : : * This function scans all the connection cache entries and disconnects
2377 : : * the open connections whose foreign server OID matches with
2378 : : * the specified one. If InvalidOid is specified, it disconnects all
2379 : : * the cached connections.
2380 : : *
2381 : : * This function emits a warning for each connection that's used in
2382 : : * the current transaction and doesn't close it. It returns true if
2383 : : * it disconnects at least one connection, otherwise false.
2384 : : *
2385 : : * Note that this function disconnects even the connections that are
2386 : : * established by other users in the same local session using different
2387 : : * user mappings. This leads even non-superuser to be able to close
2388 : : * the connections established by superusers in the same local session.
2389 : : *
2390 : : * XXX As of now we don't see any security risk doing this. But we should
2391 : : * set some restrictions on that, for example, prevent non-superuser
2392 : : * from closing the connections established by superusers even
2393 : : * in the same session?
2394 : : */
2395 : : static bool
2396 : 8 : disconnect_cached_connections(Oid serverid)
2397 : : {
2398 : : HASH_SEQ_STATUS scan;
2399 : : ConnCacheEntry *entry;
2400 : 8 : bool all = !OidIsValid(serverid);
2401 : 8 : bool result = false;
2402 : :
2403 : : /*
2404 : : * Connection cache hashtable has not been initialized yet in this
2405 : : * session, so return false.
2406 : : */
2407 [ - + ]: 8 : if (!ConnectionHash)
1684 fujii@postgresql.org 2408 :UBC 0 : return false;
2409 : :
1684 fujii@postgresql.org 2410 :CBC 8 : hash_seq_init(&scan, ConnectionHash);
2411 [ + + ]: 67 : while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
2412 : : {
2413 : : /* Ignore cache entry if no open connection right now. */
2414 [ + + ]: 59 : if (!entry->conn)
2415 : 47 : continue;
2416 : :
2417 [ + + + + ]: 12 : if (all || entry->serverid == serverid)
2418 : : {
2419 : : /*
2420 : : * Emit a warning because the connection to close is used in the
2421 : : * current transaction and cannot be disconnected right now.
2422 : : */
2423 [ + + ]: 9 : if (entry->xact_depth > 0)
2424 : : {
2425 : : ForeignServer *server;
2426 : :
2427 : 3 : server = GetForeignServerExtended(entry->serverid,
2428 : : FSV_MISSING_OK);
2429 : :
2430 [ - + ]: 3 : if (!server)
2431 : : {
2432 : : /*
2433 : : * If the foreign server was dropped while its connection
2434 : : * was used in the current transaction, the connection
2435 : : * must have been marked as invalid by
2436 : : * pgfdw_inval_callback at the end of DROP SERVER command.
2437 : : */
1684 fujii@postgresql.org 2438 [ # # ]:UBC 0 : Assert(entry->invalidated);
2439 : :
2440 [ # # ]: 0 : ereport(WARNING,
2441 : : (errmsg("cannot close dropped server connection because it is still in use")));
2442 : : }
2443 : : else
1684 fujii@postgresql.org 2444 [ + - ]:CBC 3 : ereport(WARNING,
2445 : : (errmsg("cannot close connection for server \"%s\" because it is still in use",
2446 : : server->servername)));
2447 : : }
2448 : : else
2449 : : {
2450 [ - + ]: 6 : elog(DEBUG3, "discarding connection %p", entry->conn);
2451 : 6 : disconnect_pg_server(entry);
2452 : 6 : result = true;
2453 : : }
2454 : : }
2455 : : }
2456 : :
2457 : 8 : return result;
2458 : : }
2459 : :
2460 : : /*
2461 : : * Check if the remote server closed the connection.
2462 : : *
2463 : : * Returns 1 if the connection is closed, -1 if an error occurred,
2464 : : * and 0 if it's not closed or if the connection check is unavailable
2465 : : * on this platform.
2466 : : */
2467 : : static int
407 2468 : 2 : pgfdw_conn_check(PGconn *conn)
2469 : : {
2470 : 2 : int sock = PQsocket(conn);
2471 : :
2472 [ + - - + ]: 2 : if (PQstatus(conn) != CONNECTION_OK || sock == -1)
407 fujii@postgresql.org 2473 :UBC 0 : return -1;
2474 : :
2475 : : #if (defined(HAVE_POLL) && defined(POLLRDHUP))
2476 : : {
2477 : : struct pollfd input_fd;
2478 : : int result;
2479 : :
407 fujii@postgresql.org 2480 :CBC 2 : input_fd.fd = sock;
2481 : 2 : input_fd.events = POLLRDHUP;
2482 : 2 : input_fd.revents = 0;
2483 : :
2484 : : do
2485 : 2 : result = poll(&input_fd, 1, 0);
2486 [ - + - - ]: 2 : while (result < 0 && errno == EINTR);
2487 : :
2488 [ - + ]: 2 : if (result < 0)
407 fujii@postgresql.org 2489 :UBC 0 : return -1;
2490 : :
406 fujii@postgresql.org 2491 :CBC 2 : return (input_fd.revents &
2492 : 2 : (POLLRDHUP | POLLHUP | POLLERR | POLLNVAL)) ? 1 : 0;
2493 : : }
2494 : : #else
2495 : : return 0;
2496 : : #endif
2497 : : }
2498 : :
2499 : : /*
2500 : : * Check if connection status checking is available on this platform.
2501 : : *
2502 : : * Returns true if available, false otherwise.
2503 : : */
2504 : : static bool
407 2505 : 2 : pgfdw_conn_checkable(void)
2506 : : {
2507 : : #if (defined(HAVE_POLL) && defined(POLLRDHUP))
2508 : 2 : return true;
2509 : : #else
2510 : : return false;
2511 : : #endif
2512 : : }
2513 : :
2514 : : /*
2515 : : * Ensure that require_auth and SCRAM keys are correctly set on values. SCRAM
2516 : : * keys used to pass-through are coming from the initial connection from the
2517 : : * client with the server.
2518 : : *
2519 : : * All required SCRAM options are set by postgres_fdw, so we just need to
2520 : : * ensure that these options are not overwritten by the user.
2521 : : */
2522 : : static bool
166 peter@eisentraut.org 2523 : 8 : pgfdw_has_required_scram_options(const char **keywords, const char **values)
2524 : : {
2525 : 8 : bool has_scram_server_key = false;
2526 : 8 : bool has_scram_client_key = false;
2527 : 8 : bool has_require_auth = false;
2528 : 8 : bool has_scram_keys = false;
2529 : :
2530 : : /*
2531 : : * Continue iterating even if we found the keys that we need to validate
2532 : : * to make sure that there is no other declaration of these keys that can
2533 : : * overwrite the first.
2534 : : */
2535 [ + + ]: 80 : for (int i = 0; keywords[i] != NULL; i++)
2536 : : {
2537 [ + + ]: 72 : if (strcmp(keywords[i], "scram_client_key") == 0)
2538 : : {
2539 [ + - + - ]: 8 : if (values[i] != NULL && values[i][0] != '\0')
2540 : 8 : has_scram_client_key = true;
2541 : : else
166 peter@eisentraut.org 2542 :UBC 0 : has_scram_client_key = false;
2543 : : }
2544 : :
166 peter@eisentraut.org 2545 [ + + ]:CBC 72 : if (strcmp(keywords[i], "scram_server_key") == 0)
2546 : : {
2547 [ + - + - ]: 8 : if (values[i] != NULL && values[i][0] != '\0')
2548 : 8 : has_scram_server_key = true;
2549 : : else
166 peter@eisentraut.org 2550 :UBC 0 : has_scram_server_key = false;
2551 : : }
2552 : :
166 peter@eisentraut.org 2553 [ + + ]:CBC 72 : if (strcmp(keywords[i], "require_auth") == 0)
2554 : : {
2555 [ + - + - ]: 8 : if (values[i] != NULL && strcmp(values[i], "scram-sha-256") == 0)
2556 : 8 : has_require_auth = true;
2557 : : else
166 peter@eisentraut.org 2558 :UBC 0 : has_require_auth = false;
2559 : : }
2560 : : }
2561 : :
29 peter@eisentraut.org 2562 [ + - + - :CBC 8 : has_scram_keys = has_scram_client_key && has_scram_server_key && MyProcPort != NULL && MyProcPort->has_scram_keys;
+ - + - ]
2563 : :
166 2564 [ + - + - ]: 8 : return (has_scram_keys && has_require_auth);
2565 : : }
|
