/* posix-io.c - Posix I/O functions
 *	Copyright (C) 2000 Werner Koch (dd9jn)
 *      Copyright (C) 2001 g10 Code GmbH
 *
 * This file is part of GPGME.
 *
 * GPGME is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * GPGME is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include <config.h>
#ifndef HAVE_DOSISH_SYSTEM

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <fcntl.h>
#include "syshdr.h"

#include "util.h"
#include "io.h"

static struct {
    void (*handler)(int,void*);
    void *value;
} notify_table[256];


int
_gpgme_io_read ( int fd, void *buffer, size_t count )
{
    int nread;

    DEBUG2 ("fd %d: about to read %d bytes\n", fd, (int)count );
    do {
        nread = read (fd, buffer, count);
    } while (nread == -1 && errno == EINTR );
    DEBUG2 ("fd %d: got %d bytes\n", fd, nread );
    if ( nread > 0 ) {
        _gpgme_debug (2, "fd %d: got `%.*s'\n", fd, nread, buffer );
    }
    return nread;
}


int
_gpgme_io_write ( int fd, const void *buffer, size_t count )
{
    int nwritten;

    DEBUG2 ("fd %d: about to write %d bytes\n", fd, (int)count );
    _gpgme_debug (2, "fd %d: write `%.*s'\n", fd, (int)count, buffer );
    do {
        nwritten = write (fd, buffer, count);
    } while (nwritten == -1 && errno == EINTR );
    DEBUG2 ("fd %d:          wrote %d bytes\n", fd, (int)nwritten );
    return nwritten;
}

int
_gpgme_io_pipe (int filedes[2], int inherit_idx)
{
  int err;

  err = pipe (filedes);
  if (err < 0)
    return err;
  /* FIXME: Should get the old flags first.  */
  err = fcntl (filedes[1 - inherit_idx], F_SETFD, FD_CLOEXEC);
  if (err < 0)
    {
      close (filedes[0]);
      close (filedes[1]);
    }
  return err;
}

int
_gpgme_io_close ( int fd )
{
    if ( fd == -1 )
        return -1;
    /* first call the notify handler */
    DEBUG1 ("closing fd %d", fd );
    if ( fd >= 0 && fd < DIM (notify_table) ) {
        if (notify_table[fd].handler) {
            notify_table[fd].handler (fd, notify_table[fd].value);
            notify_table[fd].handler = NULL;
            notify_table[fd].value = NULL;
        }
    }
    /* then do the close */    
    return close (fd);
}

int
_gpgme_io_set_close_notify (int fd, void (*handler)(int, void*), void *value)
{
    assert (fd != -1);

    if ( fd < 0 || fd >= DIM (notify_table) )
        return -1;
    DEBUG1 ("set notification for fd %d", fd );
    notify_table[fd].handler = handler;
    notify_table[fd].value = value;
    return 0;
}


int
_gpgme_io_set_nonblocking ( int fd )
{
    int flags;

    flags = fcntl (fd, F_GETFL, 0);
    if (flags == -1)
        return -1;
    flags |= O_NONBLOCK;
    return fcntl (fd, F_SETFL, flags);
}


int
_gpgme_io_spawn ( const char *path, char **argv,
                  struct spawn_fd_item_s *fd_child_list,
                  struct spawn_fd_item_s *fd_parent_list )
{
    static volatile int fixed_signals;
    pid_t pid;
    int i;

    if ( !fixed_signals ) { 
        struct sigaction act;
        
        sigaction( SIGPIPE, NULL, &act );
        if( act.sa_handler == SIG_DFL ) {
            act.sa_handler = SIG_IGN;
            sigemptyset( &act.sa_mask );
            act.sa_flags = 0;
            sigaction( SIGPIPE, &act, NULL);
        }
        fixed_signals = 1;
        /* fixme: This is not really MT safe */
    }

    
    pid = fork ();
    if (pid == -1) 
        return -1;

    if ( !pid ) { /* child */
        int duped_stdin = 0;
        int duped_stderr = 0;

        /* first close all fds which will not be duped */
        for (i=0; fd_child_list[i].fd != -1; i++ ) {
            if (fd_child_list[i].dup_to == -1 )
                close (fd_child_list[i].fd);
        }
        /* and now dup and close the rest */
        for (i=0; fd_child_list[i].fd != -1; i++ ) {
            if (fd_child_list[i].dup_to != -1 ) {
                if ( dup2 (fd_child_list[i].fd,
                           fd_child_list[i].dup_to ) == -1 ) {
                    DEBUG1 ("dup2 failed in child: %s\n", strerror (errno));
                    _exit (8);
                }
                if ( fd_child_list[i].dup_to == 0 )
                    duped_stdin=1;
                if ( fd_child_list[i].dup_to == 2 )
                    duped_stderr=1;
                close (fd_child_list[i].fd);
            }
        }

        if( !duped_stdin || !duped_stderr ) {
            int fd = open ( "/dev/null", O_RDWR );
            if ( fd == -1 ) {
                DEBUG1 ("can't open `/dev/null': %s\n", strerror (errno) );
                _exit (8);
            }
            /* Make sure that the process has a connected stdin */
            if ( !duped_stdin ) {
                if ( dup2 ( fd, 0 ) == -1 ) {
                    DEBUG1("dup2(/dev/null, 0) failed: %s\n",
                             strerror (errno) );
                    _exit (8);
                }
            }
            if ( !duped_stderr ) {
                if ( dup2 ( fd, 2 ) == -1 ) {
                    DEBUG1 ("dup2(dev/null, 2) failed: %s\n", strerror (errno));
                    _exit (8);
                }
            }
            close (fd);
        }

        execv ( path, argv );
        /* Hmm: in that case we could write a special status code to the
         * status-pipe */
        DEBUG1 ("exec of `%s' failed\n", path );
        _exit (8);
    } /* end child */
    
    /* .dup_to is not used in the parent list */
    for (i=0; fd_parent_list[i].fd != -1; i++ ) {
        close (fd_parent_list[i].fd);
    }

    return (int)pid;
}


int
_gpgme_io_waitpid ( int pid, int hang, int *r_status, int *r_signal )
{
    int status;

    *r_status = 0;
    *r_signal = 0;
    if ( waitpid ( pid, &status, hang? 0 : WNOHANG ) == pid ) {
        if ( WIFSIGNALED (status) ) {
            *r_status = 4; /* Need some value here */
            *r_signal = WTERMSIG (status);
        }
        else if ( WIFEXITED (status) ) {
            *r_status = WEXITSTATUS (status);
        }
        else {
            *r_status = 4; /* oops */
        }
        return 1;
    }
    return 0;
}

int
_gpgme_io_kill ( int pid, int hard )
{
    return kill ( pid, hard? SIGKILL : SIGTERM );
}


/*
 * Select on the list of fds.
 * Returns: -1 = error
 *           0 = timeout or nothing to select
 *          >0 = number of signaled fds
 */
int
_gpgme_io_select ( struct io_select_fd_s *fds, size_t nfds )
{
    static fd_set readfds;
    static fd_set writefds;
    int any, i, max_fd, n, count;
    struct timeval timeout = { 1, 0 }; /* Use a 1s timeout */
    void *dbg_help = NULL;
    
    FD_ZERO ( &readfds );
    FD_ZERO ( &writefds );
    max_fd = 0;

    if ( _gpgme_debug_level () > 2 )
        DEBUG_BEGIN (dbg_help, "gpgme:select on [ ");
    any = 0;
    for ( i=0; i < nfds; i++ ) {
        if ( fds[i].fd == -1 ) 
            continue;
        if ( fds[i].frozen ) {
            DEBUG_ADD1 (dbg_help, "f%d ", fds[i].fd );
        }
        else if ( fds[i].for_read ) {
            assert ( !FD_ISSET ( fds[i].fd, &readfds ) );
            FD_SET ( fds[i].fd, &readfds );
            if ( fds[i].fd > max_fd )
                max_fd = fds[i].fd;
            DEBUG_ADD1 (dbg_help, "r%d ", fds[i].fd );
            any = 1;
        }
        else if ( fds[i].for_write ) {
            assert ( !FD_ISSET ( fds[i].fd, &writefds ) );
            FD_SET ( fds[i].fd, &writefds );
            if ( fds[i].fd > max_fd )
                max_fd = fds[i].fd;
            DEBUG_ADD1 (dbg_help, "w%d ", fds[i].fd );
            any = 1;
        }
        fds[i].signaled = 0;
    }
    DEBUG_END (dbg_help, "]" ); 
    if ( !any )
        return 0;

    do {
        count = select ( max_fd+1, &readfds, &writefds, NULL, &timeout );
    } while ( count < 0 && errno == EINTR);
    if ( count < 0 ) {
        DEBUG1 ("_gpgme_io_select failed: %s\n", strerror (errno) );
        return -1; /* error */
    }

    if ( _gpgme_debug_level () > 2 )
        DEBUG_BEGIN (dbg_help, "select OK [ " );
    if (DEBUG_ENABLED(dbg_help)) {
        for (i=0; i <= max_fd; i++ ) {
            if (FD_ISSET (i, &readfds) )
                DEBUG_ADD1 (dbg_help, "r%d ", i );
            if (FD_ISSET (i, &writefds) )
                DEBUG_ADD1 (dbg_help, "w%d ", i );
        }
        DEBUG_END (dbg_help, "]" );
    }
    
    /* n is used to optimize it a little bit */
    for ( n=count, i=0; i < nfds && n ; i++ ) {
        if ( fds[i].fd == -1 ) 
            ;
        else if ( fds[i].for_read ) {
            if ( FD_ISSET ( fds[i].fd, &readfds ) ) {
                fds[i].signaled = 1;
                n--;
            }
        }
        else if ( fds[i].for_write ) {
            if ( FD_ISSET ( fds[i].fd, &writefds ) ) {
                fds[i].signaled = 1;
                n--;
            }
        }
    }
    return count;
}


#endif /*!HAVE_DOSISH_SYSTEM*/