postgresql-bug #18210 reproducer

bug-gssapi-caller.c

/*
 * Run this program in a Kerberos capable environment and it should fail like so:
 *   $ gcc -I /usr/include/postgresql  bug-gssapi-caller.c -o bug-gssapi-caller -l pq
 *   $ ./bug-gssapi-caller
 *   PQputCopyData text2 command failed: GSSAPI caller failed to retransmit all data needing to be retried
 */

#ifdef WIN32
#include <windows.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/types.h>

#include <libpq-fe.h>

static void
exit_nicely(PGconn *conn)
{
    PQfinish(conn);
    exit(1);
}

static void
wait_socket(PGconn *conn)
{
    /* Quit after four notifies are received. */
    while (PQisBusy(conn)) {
        int         sock;
        fd_set      input_mask;

        PQflush(conn);

        sock = PQsocket(conn);
        if (sock < 0)
            break;              /* shouldn't happen */

        FD_ZERO(&input_mask);
        FD_SET(sock, &input_mask);

        if (select(sock + 1, &input_mask, NULL, NULL, NULL) < 0)
        {
            fprintf(stderr, "select() failed: %s\n", strerror(errno));
            exit_nicely(conn);
        }

        /* Now check for input */
        PQconsumeInput(conn);
    }
}

int
main(int argc, char **argv)
{
    PGconn     *conn;
    PGresult   *res;
    PGnotify   *notify;
    int         nnotifies;

    /* Make a connection to the database
     * With gssencmode=disable the program finishes.
     * With gssencmode=require it fails after some loops.
     */
    conn = PQconnectdb("host=comdb2 dbname=Entwicklung gssencmode=require");

    /* Check to see that the backend connection was successfully made */
    if (PQstatus(conn) != CONNECTION_OK) {
        fprintf(stderr, "%s", PQerrorMessage(conn));
        exit_nicely(conn);
    }

    res = PQexec(conn,
        "CREATE TEMP TABLE mycopy (id SERIAL PRIMARY KEY, data TEXT)");
    if (PQresultStatus(res) != PGRES_COMMAND_OK) {
        fprintf(stderr, "CREATE TABLE failed: %s", PQerrorMessage(conn));
        PQclear(res);
        exit_nicely(conn);
    }
    PQclear(res);

    if(PQsetnonblocking(conn, 1) == -1) {
        fprintf(stderr, "PQsetnonblocking failed: %s", PQerrorMessage(conn));
        PQclear(res);
        exit_nicely(conn);
    }

    PQsendQuery(conn, "COPY mycopy (data) FROM STDIN");
    /* wait_socket is called for completeness only.
     * Otherwise PQgetResult() just blocks even in nonblocking mode. */
    wait_socket(conn);
    res = PQgetResult(conn);
    if (PQresultStatus(res) != PGRES_COPY_IN) {
        fprintf(stderr, "COPY command failed: %s", PQerrorMessage(conn));
        PQclear(res);
        exit_nicely(conn);
    }
    PQclear(res);

    char *text1 = malloc(27000);
    char *text2 = malloc(180);
    for(int i = 0; i < 100000; i++) {
        if( PQputCopyData(conn, text1, 27000) != 1) {
            fprintf(stderr, "PQputCopyData text1 command failed: %s", PQerrorMessage(conn));
            exit_nicely(conn);
        }
        if( PQputCopyData(conn, text2, 180) != 1) {
            fprintf(stderr, "PQputCopyData text2 command failed: %s", PQerrorMessage(conn));
            exit_nicely(conn);
        }
    }

    fprintf(stderr, "Done.\n");

    /* close the connection to the database and cleanup */
    PQfinish(conn);

    return 0;
}