1 /*-------------------------------------------------------------------------
4 * This file contains internal definitions meant to be used only by
5 * the frontend libpq library, not by applications that call it.
7 * An application can include this file if it wants to bypass the
8 * official API defined by libpq-fe.h, but code that does so is much
9 * more likely to break across PostgreSQL releases than code that uses
10 * only the official API.
12 * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
13 * Portions Copyright (c) 1994, Regents of the University of California
15 * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.85 2004/03/05 01:53:59 tgl Exp $
17 *-------------------------------------------------------------------------
23 /* We assume libpq-fe.h has already been included. */
24 #include "postgres_fe.h"
27 #include <sys/types.h>
32 #ifdef ENABLE_THREAD_SAFETY
36 #if defined(WIN32) && (!defined(ssize_t))
37 typedef int ssize_t; /* ssize_t doesn't exist in VC (at least
41 /* include stuff common to fe and be */
42 #include "getaddrinfo.h"
43 #include "libpq/pqcomm.h"
44 #include "lib/dllist.h"
45 /* include stuff found in fe only */
46 #include "pqexpbuffer.h"
49 #include <openssl/ssl.h>
50 #include <openssl/err.h>
54 * POSTGRES backend dependent Constants.
56 #define PQERRORMSG_LENGTH 1024
57 #define CMDSTATUS_LEN 40
60 * PGresult and the subsidiary types PGresAttDesc, PGresAttValue
61 * represent the result of a query (or more precisely, of a single SQL
62 * command --- a query string given to PQexec can contain multiple commands).
63 * Note we assume that a single command can return at most one tuple group,
64 * hence there is no need for multiple descriptor sets.
67 /* Subsidiary-storage management structure for PGresult.
68 * See space management routines in fe-exec.c for details.
69 * Note that space[k] refers to the k'th byte starting from the physical
70 * head of the block --- it's a union, not a struct!
72 typedef union pgresult_data PGresult_data;
76 PGresult_data *next; /* link to next block, or NULL */
77 char space[1]; /* dummy for accessing block as bytes */
80 /* Data about a single attribute (column) of a query result */
82 typedef struct pgresAttDesc
84 char *name; /* column name */
85 Oid tableid; /* source table, if known */
86 int columnid; /* source column, if known */
87 int format; /* format code for value (text/binary) */
88 Oid typid; /* type id */
89 int typlen; /* type size */
90 int atttypmod; /* type-specific modifier info */
94 * Data for a single attribute of a single tuple
96 * We use char* for Attribute values.
98 * The value pointer always points to a null-terminated area; we add a
99 * null (zero) byte after whatever the backend sends us. This is only
100 * particularly useful for text values ... with a binary value, the
101 * value might have embedded nulls, so the application can't use C string
102 * operators on it. But we add a null anyway for consistency.
103 * Note that the value itself does not contain a length word.
105 * A NULL attribute is a special case in two ways: its len field is NULL_LEN
106 * and its value field points to null_field in the owning PGresult. All the
107 * NULL attributes in a query result point to the same place (there's no need
108 * to store a null string separately for each one).
111 #define NULL_LEN (-1) /* pg_result len for NULL value */
113 typedef struct pgresAttValue
115 int len; /* length in bytes of the value */
116 char *value; /* actual value, plus terminating zero
120 /* Typedef for message-field list entries */
121 typedef struct pgMessageField
123 struct pgMessageField *next; /* list link */
124 char code; /* field code */
125 char contents[1]; /* field value (VARIABLE LENGTH) */
128 /* Fields needed for notice handling */
131 PQnoticeReceiver noticeRec; /* notice message receiver */
133 PQnoticeProcessor noticeProc; /* notice message processor */
141 PGresAttDesc *attDescs;
142 PGresAttValue **tuples; /* each PGresTuple is an array of
144 int tupArrSize; /* allocated size of tuples array */
145 ExecStatusType resultStatus;
146 char cmdStatus[CMDSTATUS_LEN]; /* cmd status from the
148 int binary; /* binary tuple values if binary == 1,
152 * These fields are copied from the originating PGconn, so that
153 * operations on the PGresult don't have to reference the PGconn.
155 PGNoticeHooks noticeHooks;
156 int client_encoding; /* encoding id */
159 * Error information (all NULL if not an error result). errMsg is the
160 * "overall" error message returned by PQresultErrorMessage. If we
161 * have per-field info then it is stored in a linked list.
163 char *errMsg; /* error message, or NULL if no error */
164 PGMessageField *errFields; /* message broken into fields */
166 /* All NULL attributes in the query result point to this null string */
170 * Space management information. Note that attDescs and error stuff,
171 * if not null, point into allocated blocks. But tuples points to a
172 * separately malloc'd block, so that we can realloc it.
174 PGresult_data *curBlock; /* most recently allocated block */
175 int curOffset; /* start offset of free space in block */
176 int spaceLeft; /* number of free bytes remaining in block */
179 /* PGAsyncStatusType defines the state of the query-execution state machine */
182 PGASYNC_IDLE, /* nothing's happening, dude */
183 PGASYNC_BUSY, /* query in progress */
184 PGASYNC_READY, /* result ready for PQgetResult */
185 PGASYNC_COPY_IN, /* Copy In data transfer in progress */
186 PGASYNC_COPY_OUT /* Copy Out data transfer in progress */
189 /* PGSetenvStatusType defines the state of the PQSetenv state machine */
190 /* (this is used only for 2.0-protocol connections) */
193 SETENV_STATE_OPTION_SEND, /* About to send an Environment Option */
194 SETENV_STATE_OPTION_WAIT, /* Waiting for above send to complete */
195 SETENV_STATE_QUERY1_SEND, /* About to send a status query */
196 SETENV_STATE_QUERY1_WAIT, /* Waiting for query to complete */
197 SETENV_STATE_QUERY2_SEND, /* About to send a status query */
198 SETENV_STATE_QUERY2_WAIT, /* Waiting for query to complete */
200 } PGSetenvStatusType;
202 /* Typedef for the EnvironmentOptions[] array */
203 typedef struct PQEnvironmentOption
205 const char *envName, /* name of an environment variable */
206 *pgName; /* name of corresponding SET variable */
207 } PQEnvironmentOption;
209 /* Typedef for parameter-status list entries */
210 typedef struct pgParameterStatus
212 struct pgParameterStatus *next; /* list link */
213 char *name; /* parameter name */
214 char *value; /* parameter value */
215 /* Note: name and value are stored in same malloc block as struct is */
218 /* large-object-access data ... allocated only if large-object code is used. */
219 typedef struct pgLobjfuncs
221 Oid fn_lo_open; /* OID of backend function lo_open */
222 Oid fn_lo_close; /* OID of backend function lo_close */
223 Oid fn_lo_creat; /* OID of backend function lo_creat */
224 Oid fn_lo_unlink; /* OID of backend function lo_unlink */
225 Oid fn_lo_lseek; /* OID of backend function lo_lseek */
226 Oid fn_lo_tell; /* OID of backend function lo_tell */
227 Oid fn_lo_read; /* OID of backend function LOread */
228 Oid fn_lo_write; /* OID of backend function LOwrite */
232 * PGconn stores all the state data associated with a single connection
237 /* Saved values of connection options */
238 char *pghost; /* the machine on which the server is
240 char *pghostaddr; /* the IPv4 address of the machine on
241 * which the server is running, in IPv4
242 * numbers-and-dots notation. Takes
243 * precedence over above. */
244 char *pgport; /* the server's communication port */
245 char *pgunixsocket; /* the Unix-domain socket that the server
246 * is listening on; if NULL, uses a
247 * default constructed from pgport */
248 char *pgtty; /* tty on which the backend messages is
249 * displayed (OBSOLETE, NOT USED) */
250 char *connect_timeout; /* connection timeout (numeric string) */
251 char *pgoptions; /* options to start the backend with */
252 char *dbName; /* database name */
253 char *pguser; /* Postgres username and password, if any */
255 char *sslmode; /* SSL mode (require,prefer,allow,disable) */
257 /* Optional file to write trace info to */
260 /* Callback procedures for notice message processing */
261 PGNoticeHooks noticeHooks;
263 /* Status indicators */
264 ConnStatusType status;
265 PGAsyncStatusType asyncStatus;
266 PGTransactionStatusType xactStatus;
267 /* note: xactStatus never changes to ACTIVE */
268 bool nonblocking; /* whether this connection is using
269 * nonblock sending semantics */
270 bool ext_query; /* was our last query sent with extended
272 char copy_is_binary; /* 1 = copy binary, 0 = copy text */
273 int copy_already_done; /* # bytes already returned in
275 Dllist *notifyList; /* Notify msgs not yet handed to
278 /* Connection data */
279 int sock; /* Unix FD for socket, -1 if not connected */
280 SockAddr laddr; /* Local address */
281 SockAddr raddr; /* Remote address */
282 ProtocolVersion pversion; /* FE/BE protocol version in use */
283 int sversion; /* server version, e.g. 70401 for 7.4.1 */
285 /* Transient state needed while establishing connection */
286 struct addrinfo *addrlist; /* list of possible backend addresses */
287 struct addrinfo *addr_cur; /* the one currently being tried */
288 int addrlist_family; /* needed to know how to free addrlist */
289 PGSetenvStatusType setenv_state; /* for 2.0 protocol only */
290 const PQEnvironmentOption *next_eo;
292 /* Miscellaneous stuff */
293 int be_pid; /* PID of backend --- needed for cancels */
294 int be_key; /* key of backend --- needed for cancels */
295 char md5Salt[4]; /* password salt received from backend */
296 char cryptSalt[2]; /* password salt received from backend */
297 pgParameterStatus *pstatus; /* ParameterStatus data */
298 int client_encoding; /* encoding id */
299 PGVerbosity verbosity; /* error/notice message verbosity */
300 PGlobjfuncs *lobjfuncs; /* private state for large-object access
303 /* Buffer for data received from backend and not yet processed */
304 char *inBuffer; /* currently allocated buffer */
305 int inBufSize; /* allocated size of buffer */
306 int inStart; /* offset to first unconsumed data in
308 int inCursor; /* next byte to tentatively consume */
309 int inEnd; /* offset to first position after avail
312 /* Buffer for data not yet sent to backend */
313 char *outBuffer; /* currently allocated buffer */
314 int outBufSize; /* allocated size of buffer */
315 int outCount; /* number of chars waiting in buffer */
317 /* State for constructing messages in outBuffer */
318 int outMsgStart; /* offset to msg start (length word); if
319 * -1, msg has no length word */
320 int outMsgEnd; /* offset to msg end (so far) */
322 /* Status for asynchronous result construction */
323 PGresult *result; /* result being constructed */
324 PGresAttValue *curTuple; /* tuple currently being read */
327 bool allow_ssl_try; /* Allowed to try SSL negotiation */
328 bool wait_ssl_try; /* Delay SSL negotiation until after
329 * attempting normal connection */
330 SSL *ssl; /* SSL status, if have SSL connection */
331 X509 *peer; /* X509 cert of server */
332 char peer_dn[256 + 1]; /* peer distinguished name */
333 char peer_cn[SM_USER + 1]; /* peer common name */
336 /* Buffer for current error message */
337 PQExpBufferData errorMessage; /* expansible string */
339 /* Buffer for receiving various parts of messages */
340 PQExpBufferData workBuffer; /* expansible string */
343 /* String descriptions of the ExecStatusTypes.
344 * direct use of this array is deprecated; call PQresStatus() instead.
346 extern char *const pgresStatus[];
349 * Internal functions of libpq
350 * Functions declared here need to be visible across files of libpq,
351 * but are not intended to be called by applications. We use the
352 * convention "pqXXX" for internal functions, vs. the "PQxxx" names
353 * used for application-visible routines.
357 /* === in fe-connect.c === */
359 extern int pqPacketSend(PGconn *conn, char pack_type,
360 const void *buf, size_t buf_len);
362 /* === in fe-exec.c === */
364 extern void pqSetResultError(PGresult *res, const char *msg);
365 extern void pqCatenateResultError(PGresult *res, const char *msg);
366 extern void *pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary);
367 extern char *pqResultStrdup(PGresult *res, const char *str);
368 extern void pqClearAsyncResult(PGconn *conn);
369 extern void pqSaveErrorResult(PGconn *conn);
370 extern PGresult *pqPrepareAsyncResult(PGconn *conn);
372 pqInternalNotice(const PGNoticeHooks * hooks, const char *fmt,...)
373 /* This lets gcc check the format string for consistency. */
374 __attribute__((format(printf, 2, 3)));
375 extern int pqAddTuple(PGresult *res, PGresAttValue * tup);
376 extern void pqSaveMessageField(PGresult *res, char code,
378 extern void pqSaveParameterStatus(PGconn *conn, const char *name,
380 extern void pqHandleSendFailure(PGconn *conn);
382 /* === in fe-protocol2.c === */
384 extern PostgresPollingStatusType pqSetenvPoll(PGconn *conn);
386 extern char *pqBuildStartupPacket2(PGconn *conn, int *packetlen,
387 const PQEnvironmentOption * options);
388 extern void pqParseInput2(PGconn *conn);
389 extern int pqGetCopyData2(PGconn *conn, char **buffer, int async);
390 extern int pqGetline2(PGconn *conn, char *s, int maxlen);
391 extern int pqGetlineAsync2(PGconn *conn, char *buffer, int bufsize);
392 extern int pqEndcopy2(PGconn *conn);
393 extern PGresult *pqFunctionCall2(PGconn *conn, Oid fnid,
394 int *result_buf, int *actual_result_len,
396 const PQArgBlock *args, int nargs);
398 /* === in fe-protocol3.c === */
400 extern char *pqBuildStartupPacket3(PGconn *conn, int *packetlen,
401 const PQEnvironmentOption * options);
402 extern void pqParseInput3(PGconn *conn);
403 extern int pqGetErrorNotice3(PGconn *conn, bool isError);
404 extern int pqGetCopyData3(PGconn *conn, char **buffer, int async);
405 extern int pqGetline3(PGconn *conn, char *s, int maxlen);
406 extern int pqGetlineAsync3(PGconn *conn, char *buffer, int bufsize);
407 extern int pqEndcopy3(PGconn *conn);
408 extern PGresult *pqFunctionCall3(PGconn *conn, Oid fnid,
409 int *result_buf, int *actual_result_len,
411 const PQArgBlock *args, int nargs);
413 /* === in fe-misc.c === */
416 * "Get" and "Put" routines return 0 if successful, EOF if not. Note that
417 * for Get, EOF merely means the buffer is exhausted, not that there is
418 * necessarily any error.
420 extern int pqCheckOutBufferSpace(int bytes_needed, PGconn *conn);
421 extern int pqCheckInBufferSpace(int bytes_needed, PGconn *conn);
422 extern int pqGetc(char *result, PGconn *conn);
423 extern int pqPutc(char c, PGconn *conn);
424 extern int pqGets(PQExpBuffer buf, PGconn *conn);
425 extern int pqPuts(const char *s, PGconn *conn);
426 extern int pqGetnchar(char *s, size_t len, PGconn *conn);
427 extern int pqPutnchar(const char *s, size_t len, PGconn *conn);
428 extern int pqGetInt(int *result, size_t bytes, PGconn *conn);
429 extern int pqPutInt(int value, size_t bytes, PGconn *conn);
430 extern int pqPutMsgStart(char msg_type, bool force_len, PGconn *conn);
431 extern int pqPutMsgEnd(PGconn *conn);
432 extern int pqReadData(PGconn *conn);
433 extern int pqFlush(PGconn *conn);
434 extern int pqWait(int forRead, int forWrite, PGconn *conn);
435 extern int pqWaitTimed(int forRead, int forWrite, PGconn *conn,
437 extern int pqReadReady(PGconn *conn);
438 extern int pqWriteReady(PGconn *conn);
440 /* === in fe-secure.c === */
442 extern int pqsecure_initialize(PGconn *);
443 extern void pqsecure_destroy(void);
444 extern PostgresPollingStatusType pqsecure_open_client(PGconn *);
445 extern void pqsecure_close(PGconn *);
446 extern ssize_t pqsecure_read(PGconn *, void *ptr, size_t len);
447 extern ssize_t pqsecure_write(PGconn *, const void *ptr, size_t len);
448 #ifdef ENABLE_THREAD_SAFETY
449 extern void check_sigpipe_handler(void);
450 extern pthread_key_t thread_in_send;
454 * this is so that we can check if a connection is non-blocking internally
455 * without the overhead of a function call
457 #define pqIsnonblocking(conn) ((conn)->nonblocking)
461 libpq_gettext(const char *msgid)
462 __attribute__((format_arg(1)));
465 #define libpq_gettext(x) (x)
469 * These macros are needed to let error-handling code be portable between
470 * Unix and Windows. (ugh)
473 #define SOCK_ERRNO (WSAGetLastError())
474 #define SOCK_STRERROR winsock_strerror
475 #define SOCK_ERRNO_SET(e) WSASetLastError(e)
477 #define SOCK_ERRNO errno
478 #define SOCK_STRERROR pqStrerror
479 #define SOCK_ERRNO_SET(e) errno=e
482 #endif /* LIBPQ_INT_H */