1 /*-------------------------------------------------------------------------
4 * functions related to setting up a connection to the backend
6 * Copyright (c) 1994, Regents of the University of California
10 * $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.20 1996/11/26 03:20:35 bryanh Exp $
12 *-------------------------------------------------------------------------
16 #include <sys/types.h>
17 #include <sys/socket.h>
26 #include <ctype.h> /* for isspace() */
29 #include "libpq/pqcomm.h" /* for decls of MsgType, PacketBuf, StartupInfo */
33 #include <port-protos.h> /* for strdup() */
35 #if defined(ultrix4) || defined(next)
36 /* ultrix is lame and doesn't have strdup in libc for some reason */
37 /* [TRH] So doesn't NEXTSTEP. But whaddaya expect for a non-ANSI
38 standard function? (My, my. Touchy today, are we?) */
40 strdup(const char *string)
44 if ((nstr = malloc(strlen(string)+1)) != NULL)
50 /* use a local version instead of the one found in pqpacket.c */
51 static ConnStatusType connectDB(PGconn *conn);
53 static int packetSend(Port *port, PacketBuf *buf, PacketLen len,
55 static void startup2PacketBuf(StartupInfo* s, PacketBuf* res);
56 static void freePGconn(PGconn *conn);
57 static void closePGconn(PGconn *conn);
58 static int conninfo_parse(const char *conninfo, char *errorMessage);
59 static char *conninfo_getval(char *keyword);
60 static void conninfo_free(void);
62 #define NOTIFYLIST_INITIAL_SIZE 10
63 #define NOTIFYLIST_GROWBY 10
67 * Definition of the conninfo parameters and their fallback resources.
68 * If Environment-Var and Compiled-in are specified as NULL, no
69 * fallback is available. If after all no value can be determined
70 * for an option, an error is returned.
72 * The values for dbname and user are treated special in conninfo_parse.
73 * If the Compiled-in resource is specified as a NULL value, the
74 * user is determined by fe_getauthname() and for dbname the user
77 * The Label and Disp-Char entries are provided for applications that
78 * want to use PQconndefaults() to create a generic database connection
79 * dialog. Disp-Char is defined as follows:
80 * "" Normal input field
83 static PQconninfoOption PQconninfoOptions[] = {
84 /* ----------------------------------------------------------------- */
85 /* Option-name Environment-Var Compiled-in Current value */
87 /* ----------------- --------------- --------------- --------------- */
88 { "user", "PGUSER", NULL, NULL,
89 "Database-User", "", 20 },
91 { "dbname", "PGDATABASE", NULL, NULL,
92 "Database-Name", "", 20 },
94 { "host", "PGHOST", DefaultHost, NULL,
95 "Database-Host", "", 40 },
97 { "port", "PGPORT", DEF_PGPORT, NULL,
98 "Database-Port", "", 6 },
100 { "tty", "PGTTY", DefaultTty, NULL,
101 "Backend-Debug-TTY", "D", 40 },
103 { "options", "PGOPTIONS", DefaultOption, NULL,
104 "Backend-Debug-Options", "D", 40 },
105 /* ----------------- --------------- --------------- --------------- */
106 { NULL, NULL, NULL, NULL,
113 * establishes a connectin to a postgres backend through the postmaster
114 * using connection information in a string.
116 * The conninfo string is a list of
120 * definitions. Value might be a single value containing no whitespaces
121 * or a single quoted string. If a single quote should appear everywhere
122 * in the value, it must be escaped with a backslash like \'
124 * Returns a PGconn* which is needed for all subsequent libpq calls
125 * if the status field of the connection returned is CONNECTION_BAD,
126 * then some fields may be null'ed out instead of having valid values
130 PQconnectdb(const char *conninfo)
133 PQconninfoOption *option;
134 char errorMessage[ERROR_MSG_LENGTH];
137 * Allocate memory for the conn structure
140 conn = (PGconn*)malloc(sizeof(PGconn));
143 "FATAL: PQsetdb() -- unable to allocate memory for a PGconn");
144 return (PGconn*)NULL;
146 memset((char *)conn, 0, sizeof(PGconn));
149 * Parse the conninfo string and get the fallback resources
152 if(conninfo_parse(conninfo, errorMessage) < 0) {
153 conn->status = CONNECTION_BAD;
154 strcpy(conn->errorMessage, errorMessage);
160 * Check that we have all connection parameters
163 for(option = PQconninfoOptions; option->keyword != NULL; option++) {
164 if(option->val != NULL) continue; /* Value was in conninfo */
167 * No value was found for this option. Return an error.
170 conn->status = CONNECTION_BAD;
171 sprintf(conn->errorMessage,
172 "ERROR: PQconnectdb(): Cannot determine a value for option '%s'.\n",
174 strcat(conn->errorMessage,
175 "Option not specified in conninfo string");
176 if(option->environ) {
177 strcat(conn->errorMessage,
178 ", environment variable ");
179 strcat(conn->errorMessage, option->environ);
180 strcat(conn->errorMessage, "\nnot set");
182 strcat(conn->errorMessage, " and no compiled in default value.\n");
188 * Setup the conn structure
193 conn->Pfdebug = NULL;
195 conn->notifyList = DLNewList();
197 conn->pghost = strdup(conninfo_getval("host"));
198 conn->pgport = strdup(conninfo_getval("port"));
199 conn->pgtty = strdup(conninfo_getval("tty"));
200 conn->pgoptions = strdup(conninfo_getval("options"));
201 conn->pguser = strdup(conninfo_getval("user"));
202 conn->dbName = strdup(conninfo_getval("dbname"));
205 * Free the connection info - all is in conn now
211 * Connect to the database
214 conn->status = connectDB(conn);
215 if (conn->status == CONNECTION_OK) {
217 /* Send a blank query to make sure everything works; in particular, that
220 res = PQexec(conn," ");
221 if (res == NULL || res->resultStatus != PGRES_EMPTY_QUERY) {
222 /* PQexec has put error message in conn->errorMessage */
234 * Parse an empty string like PQconnectdb() would do and return the
235 * address of the connection options structure. Using this function
236 * an application might determine all possible options and their
237 * current default values.
243 char errorMessage[ERROR_MSG_LENGTH];
245 conninfo_parse("", errorMessage);
246 return PQconninfoOptions;
252 * establishes a connection to a postgres backend through the postmaster
253 * at the specified host and port.
255 * returns a PGconn* which is needed for all subsequent libpq calls
256 * if the status field of the connection returned is CONNECTION_BAD,
257 * then some fields may be null'ed out instead of having valid values
259 * Uses these environment variables:
261 * PGHOST identifies host to which to connect if <pghost> argument
262 * is NULL or a null string.
264 * PGPORT identifies TCP port to which to connect if <pgport> argument
265 * is NULL or a null string.
267 * PGTTY identifies tty to which to send messages if <pgtty> argument
268 * is NULL or a null string.
270 * PGOPTIONS identifies connection options if <pgoptions> argument is
271 * NULL or a null string.
273 * PGUSER Postgres username to associate with the connection.
275 * PGDATABASE name of database to which to connect if <pgdatabase>
276 * argument is NULL or a null string
278 * None of the above need be defined. There are defaults for all of them.
283 PQsetdb(const char *pghost, const char* pgport, const char* pgoptions, const char* pgtty, const char* dbName)
287 char errorMessage[ERROR_MSG_LENGTH];
288 /* An error message from some service we call. */
290 /* We encountered an error that prevents successful completion */
292 conn = (PGconn*)malloc(sizeof(PGconn));
296 "FATAL: PQsetdb() -- unable to allocate memory for a PGconn");
300 conn->Pfdebug = NULL;
302 conn->notifyList = DLNewList();
304 if (!pghost || pghost[0] == '\0') {
305 if (!(tmp = getenv("PGHOST"))) {
308 conn->pghost = strdup(tmp);
310 conn->pghost = strdup(pghost);
312 if (!pgport || pgport[0] == '\0') {
313 if (!(tmp = getenv("PGPORT"))) {
316 conn->pgport = strdup(tmp);
318 conn->pgport = strdup(pgport);
320 if (!pgtty || pgtty[0] == '\0') {
321 if (!(tmp = getenv("PGTTY"))) {
324 conn->pgtty = strdup(tmp);
326 conn->pgtty = strdup(pgtty);
328 if (!pgoptions || pgoptions[0] == '\0') {
329 if (!(tmp = getenv("PGOPTIONS"))) {
332 conn->pgoptions = strdup(tmp);
334 conn->pgoptions = strdup(pgoptions);
336 if ((tmp = getenv("PGUSER"))) {
338 conn->pguser = strdup(tmp);
340 tmp = fe_getauthname(errorMessage);
343 sprintf(conn->errorMessage,
344 "FATAL: PQsetdb: Unable to determine a Postgres username!\n");
352 if (((tmp = (char *)dbName) && (dbName[0] != '\0')) ||
353 ((tmp = getenv("PGDATABASE")))) {
354 conn->dbName = strdup(tmp);
355 } else conn->dbName = strdup(conn->pguser);
356 } else conn->dbName = NULL;
358 if (error) conn->status = CONNECTION_BAD;
360 conn->status = connectDB(conn);
361 /* Puts message in conn->errorMessage */
362 if (conn->status == CONNECTION_OK) {
364 /* Send a blank query to make sure everything works;
365 in particular, that the database exists.
367 res = PQexec(conn," ");
368 if (res == NULL || res->resultStatus != PGRES_EMPTY_QUERY) {
369 /* PQexec has put error message in conn->errorMessage */
382 * make a connection to the backend so it is ready to receive queries.
383 * return CONNECTION_OK if successful, CONNECTION_BAD if not.
386 static ConnStatusType
387 connectDB(PGconn *conn)
395 int laddrlen = sizeof(struct sockaddr);
396 Port *port = conn->port;
401 // Initialize the startup packet.
403 // This data structure is used for the seq-packet protocol. It
404 // describes the frontend-backend connection.
408 strncpy(startup.user,conn->pguser,sizeof(startup.user));
409 strncpy(startup.database,conn->dbName,sizeof(startup.database));
410 strncpy(startup.tty,conn->pgtty,sizeof(startup.tty));
411 if (conn->pgoptions) {
412 strncpy(startup.options,conn->pgoptions, sizeof(startup.options));
415 startup.options[0]='\0';
416 startup.execFile[0]='\0'; /* not used */
420 // Open a connection to postmaster/backend.
423 port = (Port *) malloc(sizeof(Port));
424 memset((char *) port, 0, sizeof(Port));
426 if (!(hp = gethostbyname(conn->pghost)) || hp->h_addrtype != AF_INET) {
427 (void) sprintf(conn->errorMessage,
428 "connectDB() -- unknown hostname: %s\n",
430 goto connect_errReturn;
432 memset((char *) &port->raddr, 0, sizeof(port->raddr));
433 memmove((char *) &(port->raddr.sin_addr),
436 port->raddr.sin_family = AF_INET;
437 portno = atoi(conn->pgport);
438 port->raddr.sin_port = htons((unsigned short)(portno));
440 /* connect to the server */
441 if ((port->sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
442 (void) sprintf(conn->errorMessage,
443 "connectDB() -- socket() failed: errno=%d\n%s\n",
444 errno, strerror(errno));
445 goto connect_errReturn;
447 if (connect(port->sock, (struct sockaddr *)&port->raddr,
448 sizeof(port->raddr)) < 0) {
449 (void) sprintf(conn->errorMessage,
450 "connectDB() failed: Is the postmaster running at '%s' on port '%s'?\n",
451 conn->pghost,conn->pgport);
452 goto connect_errReturn;
456 /* fill in the client address */
457 if (getsockname(port->sock, (struct sockaddr *) &port->laddr,
459 (void) sprintf(conn->errorMessage,
460 "connectDB() -- getsockname() failed: errno=%d\n%s\n",
461 errno, strerror(errno));
462 goto connect_errReturn;
465 /* by this point, connection has been opened */
466 msgtype = fe_getauthsvc(conn->errorMessage);
468 /* pacBuf = startup2PacketBuf(&startup);*/
469 startup2PacketBuf(&startup, &pacBuf);
470 pacBuf.msgtype = (MsgType) htonl(msgtype);
471 status = packetSend(port, &pacBuf, sizeof(PacketBuf), BLOCKING);
473 if (status == STATUS_ERROR)
475 sprintf(conn->errorMessage,
476 "connectDB() -- couldn't send complete packet: errno=%d\n%s\n", errno,strerror(errno));
477 goto connect_errReturn;
480 /* authenticate as required*/
481 if (fe_sendauth(msgtype, port, conn->pghost,
482 conn->errorMessage) != STATUS_OK) {
483 (void) sprintf(conn->errorMessage,
484 "connectDB() -- authentication failed with %s\n",
486 goto connect_errReturn;
489 /* set up the socket file descriptors */
490 conn->Pfout = fdopen(port->sock, "w");
491 conn->Pfin = fdopen(dup(port->sock), "r");
492 if (!conn->Pfout || !conn->Pfin) {
493 (void) sprintf(conn->errorMessage,
494 "connectDB() -- fdopen() failed: errno=%d\n%s\n",
495 errno, strerror(errno));
496 goto connect_errReturn;
501 return CONNECTION_OK;
504 return CONNECTION_BAD;
510 * - free the PGconn data structure
514 freePGconn(PGconn *conn)
516 if (conn->pghost) free(conn->pghost);
517 if (conn->pgtty) free(conn->pgtty);
518 if (conn->pgoptions) free(conn->pgoptions);
519 if (conn->pgport) free(conn->pgport);
520 if (conn->dbName) free(conn->dbName);
521 if (conn->pguser) free(conn->pguser);
522 if (conn->notifyList) DLFreeList(conn->notifyList);
528 - properly close a connection to the backend
531 closePGconn(PGconn *conn)
533 struct sigaction ignore_action;
534 /* This is used as a constant, but not declared as such because the
535 sigaction structure is defined differently on different systems */
536 struct sigaction oldaction;
538 /* If connection is already gone, that's cool. No reason for kernel
539 to kill us when we try to write to it. So ignore SIGPIPE signals.
541 ignore_action.sa_handler = SIG_IGN;
542 sigemptyset(&ignore_action.sa_mask);
543 ignore_action.sa_flags = 0;
544 sigaction(SIGPIPE, (struct sigaction *) &ignore_action, &oldaction);
546 fputs("X\0", conn->Pfout);
548 sigaction(SIGPIPE, &oldaction, NULL);
549 if (conn->Pfout) fclose(conn->Pfout);
550 if (conn->Pfin) fclose(conn->Pfin);
551 if (conn->Pfdebug) fclose(conn->Pfdebug);
552 conn->status = CONNECTION_BAD; /* Well, not really _bad_ - just absent */
557 properly close a connection to the backend
558 also frees the PGconn data structure so it shouldn't be re-used
562 PQfinish(PGconn *conn)
565 fprintf(stderr,"PQfinish() -- pointer to PGconn is null");
567 if (conn->status == CONNECTION_OK)
574 resets the connection to the backend
575 closes the existing connection and makes a new one
578 PQreset(PGconn *conn)
581 fprintf(stderr,"PQreset() -- pointer to PGconn is null");
584 conn->status = connectDB(conn);
591 this is just like PacketSend(), defined in backend/libpq/pqpacket.c
592 but we define it here to avoid linking in all of libpq.a
594 * packetSend -- send a single-packet message.
596 * RETURNS: STATUS_ERROR if the write fails, STATUS_OK otherwise.
597 * SIDE_EFFECTS: may block.
598 * NOTES: Non-blocking writes would significantly complicate
599 * buffer management. For now, we're not going to do it.
603 packetSend(Port *port,
609 int addrLen = sizeof(struct sockaddr_in);
613 len = sendto(port->sock, (Addr) buf, totalLen, /* flags */ 0,
614 (struct sockaddr *)&(port->raddr), addrLen);
616 if (len < totalLen) {
617 return(STATUS_ERROR);
624 * startup2PacketBuf()
626 * this is just like StartupInfo2Packet(), defined in backend/libpq/pqpacket.c
627 * but we repeat it here so we don't have to link in libpq.a
629 * converts a StartupInfo structure to a PacketBuf
632 startup2PacketBuf(StartupInfo* s, PacketBuf* res)
636 /* res = (PacketBuf*)malloc(sizeof(PacketBuf)); */
637 res->len = htonl(sizeof(PacketBuf));
638 /* use \n to delimit the strings */
643 strncpy(tmp, s->database, sizeof(s->database));
644 tmp += sizeof(s->database);
645 strncpy(tmp, s->user, sizeof(s->user));
646 tmp += sizeof(s->user);
647 strncpy(tmp, s->options, sizeof(s->options));
648 tmp += sizeof(s->options);
649 strncpy(tmp, s->execFile, sizeof(s->execFile));
650 tmp += sizeof(s->execFile);
651 strncpy(tmp, s->tty, sizeof(s->execFile));
655 * Conninfo parser routine
658 static int conninfo_parse(const char *conninfo, char *errorMessage)
666 PQconninfoOption *option;
667 char errortmp[ERROR_MSG_LENGTH];
671 if((buf = strdup(conninfo)) == NULL) {
673 "FATAL: cannot allocate memory for copy of conninfo string\n");
679 /* Skip blanks before the parameter name */
685 /* Get the parameter name */
704 /* Check that there is a following '=' */
706 sprintf(errorMessage,
707 "ERROR: PQconnectdb() - Missing '=' after '%s' in conninfo\n",
714 /* Skip blanks after the '=' */
746 sprintf(errorMessage,
747 "ERROR: PQconnectdb() - unterminated quoted string in conninfo\n");
768 * Now we have the name and the value. Search
769 * for the param record.
772 for(option = PQconninfoOptions; option->keyword != NULL; option++) {
773 if(!strcmp(option->keyword, pname)) {
777 if(option->keyword == NULL) {
778 sprintf(errorMessage,
779 "ERROR: PQconnectdb() - unknown option '%s'\n",
789 option->val = strdup(pval);
795 * Get the fallback resources for parameters not specified
796 * in the conninfo string.
799 for(option = PQconninfoOptions; option->keyword != NULL; option++) {
800 if(option->val != NULL) continue; /* Value was in conninfo */
803 * Try to get the environment variable fallback
806 if(option->environ != NULL) {
807 if((tmp = getenv(option->environ)) != NULL) {
808 option->val = strdup(tmp);
814 * No environment variable specified or this one isn't set -
818 if(option->compiled != NULL) {
819 option->val = strdup(option->compiled);
824 * Special handling for user
827 if(!strcmp(option->keyword, "user")) {
828 tmp = fe_getauthname(errortmp);
830 option->val = strdup(tmp);
835 * Special handling for dbname
838 if(!strcmp(option->keyword, "dbname")) {
839 tmp = conninfo_getval("user");
841 option->val = strdup(tmp);
851 conninfo_getval(char *keyword)
853 PQconninfoOption *option;
855 for(option = PQconninfoOptions; option->keyword != NULL; option++) {
856 if (!strcmp(option->keyword, keyword)) {
868 PQconninfoOption *option;
870 for(option = PQconninfoOptions; option->keyword != NULL; option++) {
871 if(option->val != NULL) {
878 /* =========== accessor functions for PGconn ========= */
883 fprintf(stderr,"PQdb() -- pointer to PGconn is null");
893 fprintf(stderr,"PQuser() -- pointer to PGconn is null");
903 fprintf(stderr,"PQhost() -- pointer to PGconn is null");
911 PQoptions(PGconn* conn)
914 fprintf(stderr,"PQoptions() -- pointer to PGconn is null");
917 return conn->pgoptions;
924 fprintf(stderr,"PQtty() -- pointer to PGconn is null");
934 fprintf(stderr,"PQport() -- pointer to PGconn is null");
941 PQstatus(PGconn* conn)
944 fprintf(stderr,"PQstatus() -- pointer to PGconn is null");
945 return CONNECTION_BAD;
951 PQerrorMessage(PGconn* conn)
954 fprintf(stderr,"PQerrorMessage() -- pointer to PGconn is null");
957 return conn->errorMessage;
961 PQtrace(PGconn *conn, FILE* debug_port)
964 conn->status == CONNECTION_BAD) {
968 conn->Pfdebug = debug_port;
972 PQuntrace(PGconn *conn)
975 conn->status == CONNECTION_BAD) {
979 fflush(conn->Pfdebug);
980 fclose(conn->Pfdebug);
981 conn->Pfdebug = NULL;