/*-------------------------------------------------------------------------
*
* fe-connect.c--
* functions related to setting up a connection to the backend
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.13 1996/11/03 07:14:31 scrappy Exp $
*
*-------------------------------------------------------------------------
*/
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <netdb.h>
#include <errno.h>
#include <signal.h>
#include "postgres.h"
#include "libpq/pqcomm.h" /* for decls of MsgType, PacketBuf, StartupInfo */
#include "fe-auth.h"
#include "libpq-fe.h"
#if defined(PORTNAME_ultrix4) || defined(PORTNAME_next)
/* ultrix is lame and doesn't have strdup in libc for some reason */
/* [TRH] So doesn't NEXTSTEP. But whaddaya expect for a non-ANSI
standard function? (My, my. Touchy today, are we?) */
static
char *
strdup(const char *string)
{
char *nstr;
if ((nstr = malloc(strlen(string)+1)) != NULL)
strcpy(nstr, string);
return nstr;
}
#endif
/* use a local version instead of the one found in pqpacket.c */
static ConnStatusType connectDB(PGconn *conn);
static int packetSend(Port *port, PacketBuf *buf, PacketLen len,
bool nonBlocking);
static void startup2PacketBuf(StartupInfo* s, PacketBuf* res);
static void freePGconn(PGconn *conn);
static void closePGconn(PGconn *conn);
#define NOTIFYLIST_INITIAL_SIZE 10
#define NOTIFYLIST_GROWBY 10
/* ----------------
* PQsetdb
*
* establishes a connection to a postgres backend through the postmaster
* at the specified host and port.
*
* returns a PGconn* which is needed for all subsequent libpq calls
* if the status field of the connection returned is CONNECTION_BAD,
* then some fields may be null'ed out instead of having valid values
*
* Uses these environment variables:
*
* PGHOST identifies host to which to connect if <pghost> argument
* is NULL or a null string.
*
* PGPORT identifies TCP port to which to connect if <pgport> argument
* is NULL or a null string.
*
* PGTTY identifies tty to which to send messages if <pgtty> argument
* is NULL or a null string.
*
* PGOPTIONS identifies connection options if <pgoptions> argument is
* NULL or a null string.
*
* PGUSER Postgres username to associate with the connection.
*
* PGDATABASE name of database to which to connect if <pgdatabase>
* argument is NULL or a null string
*
* None of the above need be defined. There are defaults for all of them.
*
* ----------------
*/
PGconn*
PQsetdb(const char *pghost, const char* pgport, const char* pgoptions, const char* pgtty, const char* dbName)
{
PGconn *conn;
char *tmp;
char errorMessage[ERROR_MSG_LENGTH];
/* An error message from some service we call. */
bool error;
/* We encountered an error that prevents successful completion */
conn = (PGconn*)malloc(sizeof(PGconn));
if (conn == NULL)
fprintf(stderr,
"FATAL: PQsetdb() -- unable to allocate memory for a PGconn");
else {
conn->Pfout = NULL;
conn->Pfin = NULL;
conn->Pfdebug = NULL;
conn->port = NULL;
conn->notifyList = DLNewList();
if (!pghost || pghost[0] == '\0') {
if (!(tmp = getenv("PGHOST"))) {
tmp = DefaultHost;
}
conn->pghost = strdup(tmp);
} else
conn->pghost = strdup(pghost);
if (!pgport || pgport[0] == '\0') {
if (!(tmp = getenv("PGPORT"))) {
tmp = POSTPORT;
}
conn->pgport = strdup(tmp);
} else
conn->pgport = strdup(pgport);
if (!pgtty || pgtty[0] == '\0') {
if (!(tmp = getenv("PGTTY"))) {
tmp = DefaultTty;
}
conn->pgtty = strdup(tmp);
} else
conn->pgtty = strdup(pgtty);
if (!pgoptions || pgoptions[0] == '\0') {
if (!(tmp = getenv("PGOPTIONS"))) {
tmp = DefaultOption;
}
conn->pgoptions = strdup(tmp);
} else
conn->pgoptions = strdup(pgoptions);
if ((tmp = getenv("PGUSER"))) {
error = FALSE;
conn->pguser = strdup(tmp);
} else {
tmp = fe_getauthname(errorMessage);
if (tmp == 0) {
error = TRUE;
sprintf(conn->errorMessage,
"FATAL: PQsetdb: Unable to determine a Postgres username!\n");
} else {
error = FALSE;
conn->pguser = tmp;
}
}
if (!error) {
if (((tmp = (char *)dbName) && (dbName[0] != '\0')) ||
((tmp = getenv("PGDATABASE")))) {
conn->dbName = strdup(tmp);
} else conn->dbName = conn->pguser;
} else conn->dbName = NULL;
if (error) conn->status = CONNECTION_BAD;
else {
conn->status = connectDB(conn);
/* Puts message in conn->errorMessage */
if (conn->status == CONNECTION_OK) {
PGresult *res;
/* Send a blank query to make sure everything works;
in particular, that the database exists.
*/
res = PQexec(conn," ");
if (res == NULL || res->resultStatus != PGRES_EMPTY_QUERY) {
/* PQexec has put error message in conn->errorMessage */
closePGconn(conn);
}
PQclear(res);
}
}
}
return conn;
}
/*
* connectDB -
* make a connection to the backend so it is ready to receive queries.
* return CONNECTION_OK if successful, CONNECTION_BAD if not.
*
*/
static ConnStatusType
connectDB(PGconn *conn)
{
struct hostent *hp;
StartupInfo startup;
PacketBuf pacBuf;
int status;
MsgType msgtype;
int laddrlen = sizeof(struct sockaddr);
Port *port = conn->port;
int portno;
/*
//
// Initialize the startup packet.
//
// This data structure is used for the seq-packet protocol. It
// describes the frontend-backend connection.
//
//
*/
strncpy(startup.user,conn->pguser,sizeof(startup.user));
strncpy(startup.database,conn->dbName,sizeof(startup.database));
strncpy(startup.tty,conn->pgtty,sizeof(startup.tty));
if (conn->pgoptions) {
strncpy(startup.options,conn->pgoptions, sizeof(startup.options));
}
else
startup.options[0]='\0';
startup.execFile[0]='\0'; /* not used */
/*
//
// Open a connection to postmaster/backend.
//
*/
port = (Port *) malloc(sizeof(Port));
memset((char *) port, 0, sizeof(Port));
if (!(hp = gethostbyname(conn->pghost)) || hp->h_addrtype != AF_INET) {
(void) sprintf(conn->errorMessage,
"connectDB() -- unknown hostname: %s\n",
conn->pghost);
goto connect_errReturn;
}
memset((char *) &port->raddr, 0, sizeof(port->raddr));
memmove((char *) &(port->raddr.sin_addr),
(char *) hp->h_addr,
hp->h_length);
port->raddr.sin_family = AF_INET;
portno = atoi(conn->pgport);
port->raddr.sin_port = htons((unsigned short)(portno));
/* connect to the server */
if ((port->sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
(void) sprintf(conn->errorMessage,
"connectDB() -- socket() failed: errno=%d\n%s\n",
errno, strerror(errno));
goto connect_errReturn;
}
if (connect(port->sock, (struct sockaddr *)&port->raddr,
sizeof(port->raddr)) < 0) {
(void) sprintf(conn->errorMessage,
"connectDB() failed: Is the postmaster running at '%s' on port '%s'?\n",
conn->pghost,conn->pgport);
goto connect_errReturn;
}
/* fill in the client address */
if (getsockname(port->sock, (struct sockaddr *) &port->laddr,
&laddrlen) < 0) {
(void) sprintf(conn->errorMessage,
"connectDB() -- getsockname() failed: errno=%d\n%s\n",
errno, strerror(errno));
goto connect_errReturn;
}
/* by this point, connection has been opened */
msgtype = fe_getauthsvc(conn->errorMessage);
/* pacBuf = startup2PacketBuf(&startup);*/
startup2PacketBuf(&startup, &pacBuf);
pacBuf.msgtype = (MsgType) htonl(msgtype);
status = packetSend(port, &pacBuf, sizeof(PacketBuf), BLOCKING);
if (status == STATUS_ERROR)
{
sprintf(conn->errorMessage,
"connectDB() -- couldn't send complete packet: errno=%d\n%s\n", errno,strerror(errno));
goto connect_errReturn;
}
/* authenticate as required*/
if (fe_sendauth(msgtype, port, conn->pghost,
conn->errorMessage) != STATUS_OK) {
(void) sprintf(conn->errorMessage,
"connectDB() -- authentication failed with %s\n",
conn->pghost);
goto connect_errReturn;
}
/* set up the socket file descriptors */
conn->Pfout = fdopen(port->sock, "w");
conn->Pfin = fdopen(dup(port->sock), "r");
if (!conn->Pfout || !conn->Pfin) {
(void) sprintf(conn->errorMessage,
"connectDB() -- fdopen() failed: errno=%d\n%s\n",
errno, strerror(errno));
goto connect_errReturn;
}
conn->port = port;
return CONNECTION_OK;
connect_errReturn:
return CONNECTION_BAD;
}
/*
* freePGconn
* - free the PGconn data structure
*
*/
static void
freePGconn(PGconn *conn)
{
if (conn->pghost) free(conn->pghost);
if (conn->pgtty) free(conn->pgtty);
if (conn->pgoptions) free(conn->pgoptions);
if (conn->pgport) free(conn->pgport);
if (conn->dbName) free(conn->dbName);
if (conn->pguser) free(conn->pguser);
if (conn->notifyList) DLFreeList(conn->notifyList);
free(conn);
}
/*
closePGconn
- properly close a connection to the backend
*/
static void
closePGconn(PGconn *conn)
{
struct sigaction ignore_action;
/* This is used as a constant, but not declared as such because the
sigaction structure is defined differently on different systems */
struct sigaction oldaction;
/* If connection is already gone, that's cool. No reason for kernel
to kill us when we try to write to it. So ignore SIGPIPE signals.
*/
ignore_action.sa_handler = SIG_IGN;
sigemptyset(&ignore_action.sa_mask);
ignore_action.sa_flags = 0;
sigaction(SIGPIPE, (struct sigaction *) &ignore_action, &oldaction);
fputs("X\0", conn->Pfout);
fflush(conn->Pfout);
sigaction(SIGPIPE, &oldaction, NULL);
if (conn->Pfout) fclose(conn->Pfout);
if (conn->Pfin) fclose(conn->Pfin);
if (conn->Pfdebug) fclose(conn->Pfdebug);
conn->status = CONNECTION_BAD; /* Well, not really _bad_ - just absent */
}
/*
PQfinish:
properly close a connection to the backend
also frees the PGconn data structure so it shouldn't be re-used
after this
*/
void
PQfinish(PGconn *conn)
{
if (!conn) {
fprintf(stderr,"PQfinish() -- pointer to PGconn is null");
} else {
if (conn->status == CONNECTION_OK)
closePGconn(conn);
freePGconn(conn);
}
}
/* PQreset :
resets the connection to the backend
closes the existing connection and makes a new one
*/
void
PQreset(PGconn *conn)
{
if (!conn) {
fprintf(stderr,"PQreset() -- pointer to PGconn is null");
} else {
closePGconn(conn);
conn->status = connectDB(conn);
}
}
/*
* PacketSend()
*
this is just like PacketSend(), defined in backend/libpq/pqpacket.c
but we define it here to avoid linking in all of libpq.a
* packetSend -- send a single-packet message.
*
* RETURNS: STATUS_ERROR if the write fails, STATUS_OK otherwise.
* SIDE_EFFECTS: may block.
* NOTES: Non-blocking writes would significantly complicate
* buffer management. For now, we're not going to do it.
*
*/
static int
packetSend(Port *port,
PacketBuf *buf,
PacketLen len,
bool nonBlocking)
{
PacketLen totalLen;
int addrLen = sizeof(struct sockaddr_in);
totalLen = len;
len = sendto(port->sock, (Addr) buf, totalLen, /* flags */ 0,
(struct sockaddr *)&(port->raddr), addrLen);
if (len < totalLen) {
return(STATUS_ERROR);
}
return(STATUS_OK);
}
/*
* startup2PacketBuf()
*
* this is just like StartupInfo2Packet(), defined in backend/libpq/pqpacket.c
* but we repeat it here so we don't have to link in libpq.a
*
* converts a StartupInfo structure to a PacketBuf
*/
static void
startup2PacketBuf(StartupInfo* s, PacketBuf* res)
{
char* tmp;
/* res = (PacketBuf*)malloc(sizeof(PacketBuf)); */
res->len = htonl(sizeof(PacketBuf));
/* use \n to delimit the strings */
res->data[0] = '\0';
tmp= res->data;
strncpy(tmp, s->database, sizeof(s->database));
tmp += sizeof(s->database);
strncpy(tmp, s->user, sizeof(s->user));
tmp += sizeof(s->user);
strncpy(tmp, s->options, sizeof(s->options));
tmp += sizeof(s->options);
strncpy(tmp, s->execFile, sizeof(s->execFile));
tmp += sizeof(s->execFile);
strncpy(tmp, s->tty, sizeof(s->execFile));
}
/* =========== accessor functions for PGconn ========= */
char*
PQdb(PGconn* conn)
{
if (!conn) {
fprintf(stderr,"PQdb() -- pointer to PGconn is null");
return (char *)NULL;
}
return conn->dbName;
}
char*
PQhost(PGconn* conn)
{
if (!conn) {
fprintf(stderr,"PQhost() -- pointer to PGconn is null");
return (char *)NULL;
}
return conn->pghost;
}
char*
PQoptions(PGconn* conn)
{
if (!conn) {
fprintf(stderr,"PQoptions() -- pointer to PGconn is null");
return (char *)NULL;
}
return conn->pgoptions;
}
char*
PQtty(PGconn* conn)
{
if (!conn) {
fprintf(stderr,"PQtty() -- pointer to PGconn is null");
return (char *)NULL;
}
return conn->pgtty;
}
char*
PQport(PGconn* conn)
{
if (!conn) {
fprintf(stderr,"PQport() -- pointer to PGconn is null");
return (char *)NULL;
}
return conn->pgport;
}
ConnStatusType
PQstatus(PGconn* conn)
{
if (!conn) {
fprintf(stderr,"PQstatus() -- pointer to PGconn is null");
return CONNECTION_BAD;
}
return conn->status;
}
char*
PQerrorMessage(PGconn* conn)
{
if (!conn) {
fprintf(stderr,"PQerrorMessage() -- pointer to PGconn is null");
return (char *)NULL;
}
return conn->errorMessage;
}
void
PQtrace(PGconn *conn, FILE* debug_port)
{
if (conn == NULL ||
conn->status == CONNECTION_BAD) {
return;
}
PQuntrace(conn);
conn->Pfdebug = debug_port;
}
void
PQuntrace(PGconn *conn)
{
if (conn == NULL ||
conn->status == CONNECTION_BAD) {
return;
}
if (conn->Pfdebug) {
fflush(conn->Pfdebug);
fclose(conn->Pfdebug);
conn->Pfdebug = NULL;
}
}