streamutil.c

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/*-------------------------------------------------------------------------
 *
 * streamutil.c - utility functions for pg_basebackup and pg_receivelog
 *
 * Author: Magnus Hagander <[email protected]>
 *
 * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *        src/bin/pg_basebackup/streamutil.c
 *-------------------------------------------------------------------------
 */

#include "postgres_fe.h"
#include "streamutil.h"

#include <stdio.h>
#include <string.h>

const char *progname;
char       *connection_string = NULL;
char       *dbhost = NULL;
char       *dbuser = NULL;
char       *dbport = NULL;
int         dbgetpassword = 0;  /* 0=auto, -1=never, 1=always */
static char *dbpassword = NULL;
PGconn     *conn = NULL;

/*
 * Connect to the server. Returns a valid PGconn pointer if connected,
 * or NULL on non-permanent error. On permanent error, the function will
 * call exit(1) directly.
 */
PGconn *
GetConnection(void)
{
    PGconn     *tmpconn;
    int         argcount = 7;   /* dbname, replication, fallback_app_name,
                                 * host, user, port, password */
    int         i;
    const char **keywords;
    const char **values;
    char       *password = NULL;
    const char *tmpparam;
    PQconninfoOption *conn_opts = NULL;
    PQconninfoOption *conn_opt;
    char       *err_msg = NULL;

    /*
     * Merge the connection info inputs given in form of connection string,
     * options and default values (dbname=replication, replication=true,
     * etc.)
     */
    i = 0;
    if (connection_string)
    {
        conn_opts = PQconninfoParse(connection_string, &err_msg);
        if (conn_opts == NULL)
        {
            fprintf(stderr, "%s: %s\n", progname, err_msg);
            return NULL;
        }

        for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++)
        {
            if (conn_opt->val != NULL && conn_opt->val[0] != '\0')
                argcount++;
        }

        keywords = pg_malloc0((argcount + 1) * sizeof(*keywords));
        values = pg_malloc0((argcount + 1) * sizeof(*values));

        for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++)
        {
            if (conn_opt->val != NULL && conn_opt->val[0] != '\0')
            {
                keywords[i] = conn_opt->keyword;
                values[i] = conn_opt->val;
                i++;
            }
        }
    }
    else
    {
        keywords = pg_malloc0((argcount + 1) * sizeof(*keywords));
        values = pg_malloc0((argcount + 1) * sizeof(*values));
    }

    keywords[i] = "dbname";
    values[i] = "replication";
    i++;
    keywords[i] = "replication";
    values[i] = "true";
    i++;
    keywords[i] = "fallback_application_name";
    values[i] = progname;
    i++;

    if (dbhost)
    {
        keywords[i] = "host";
        values[i] = dbhost;
        i++;
    }
    if (dbuser)
    {
        keywords[i] = "user";
        values[i] = dbuser;
        i++;
    }
    if (dbport)
    {
        keywords[i] = "port";
        values[i] = dbport;
        i++;
    }

    while (true)
    {
        if (password)
            free(password);

        if (dbpassword)
        {
            /*
             * We've saved a password when a previous connection succeeded,
             * meaning this is the call for a second session to the same
             * database, so just forcibly reuse that password.
             */
            keywords[i] = "password";
            values[i] = dbpassword;
            dbgetpassword = -1; /* Don't try again if this fails */
        }
        else if (dbgetpassword == 1)
        {
            password = simple_prompt(_("Password: "), 100, false);
            keywords[i] = "password";
            values[i] = password;
        }

        tmpconn = PQconnectdbParams(keywords, values, true);

        /*
         * If there is too little memory even to allocate the PGconn object
         * and PQconnectdbParams returns NULL, we call exit(1) directly.
         */
        if (!tmpconn)
        {
            fprintf(stderr, _("%s: could not connect to server\n"),
                    progname);
            exit(1);
        }

        if (PQstatus(tmpconn) == CONNECTION_BAD &&
            PQconnectionNeedsPassword(tmpconn) &&
            dbgetpassword != -1)
        {
            dbgetpassword = 1;  /* ask for password next time */
            PQfinish(tmpconn);
            continue;
        }

        if (PQstatus(tmpconn) != CONNECTION_OK)
        {
            fprintf(stderr, _("%s: could not connect to server: %s\n"),
                    progname, PQerrorMessage(tmpconn));
            PQfinish(tmpconn);
            free(values);
            free(keywords);
            if (conn_opts)
                PQconninfoFree(conn_opts);
            return NULL;
        }

        /* Connection ok! */
        free(values);
        free(keywords);
        if (conn_opts)
            PQconninfoFree(conn_opts);

        /*
         * Ensure we have the same value of integer timestamps as the server
         * we are connecting to.
         */
        tmpparam = PQparameterStatus(tmpconn, "integer_datetimes");
        if (!tmpparam)
        {
            fprintf(stderr,
                    _("%s: could not determine server setting for integer_datetimes\n"),
                    progname);
            PQfinish(tmpconn);
            exit(1);
        }

#ifdef HAVE_INT64_TIMESTAMP
        if (strcmp(tmpparam, "on") != 0)
#else
        if (strcmp(tmpparam, "off") != 0)
#endif
        {
            fprintf(stderr,
             _("%s: integer_datetimes compile flag does not match server\n"),
                    progname);
            PQfinish(tmpconn);
            exit(1);
        }

        /* Store the password for next run */
        if (password)
            dbpassword = password;
        return tmpconn;
    }
}