/* assuan-pipe-connect.c - Establish a pipe connection (client)
* Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
*
* This file is part of Assuan.
*
* Assuan is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Assuan 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "assuan-defs.h"
#ifdef _POSIX_OPEN_MAX
#define MAX_OPEN_FDS _POSIX_OPEN_MAX
#else
#define MAX_OPEN_FDS 20
#endif
#define LOG(format, args...) \
fprintf (assuan_get_assuan_log_stream (), \
assuan_get_assuan_log_prefix (), \
"%s" format , ## args)
static int
writen (int fd, const char *buffer, size_t length)
{
while (length)
{
int nwritten = write (fd, buffer, length);
if (nwritten < 0)
{
if (errno == EINTR)
continue;
return -1; /* write error */
}
length -= nwritten;
buffer += nwritten;
}
return 0; /* okay */
}
static int
do_finish (ASSUAN_CONTEXT ctx)
{
if (ctx->inbound.fd != -1)
{
close (ctx->inbound.fd);
ctx->inbound.fd = -1;
}
if (ctx->outbound.fd != -1)
{
close (ctx->outbound.fd);
ctx->outbound.fd = -1;
}
if (ctx->pid != -1)
{
waitpid (ctx->pid, NULL, 0); /* FIXME Check return value. */
ctx->pid = -1;
}
return 0;
}
static void
do_deinit (ASSUAN_CONTEXT ctx)
{
do_finish (ctx);
}
/* Connect to a server over a pipe, creating the assuan context and
returning it in CTX. The server filename is NAME, the argument
vector in ARGV. FD_CHILD_LIST is a -1 terminated list of file
descriptors not to close in the child. */
AssuanError
assuan_pipe_connect (ASSUAN_CONTEXT *ctx, const char *name, char *const argv[],
int *fd_child_list)
{
#ifndef _ASSUAN_IN_GPGME
static int fixed_signals = 0;
#endif
AssuanError err;
int rp[2];
int wp[2];
if (!ctx || !name || !argv || !argv[0])
return ASSUAN_Invalid_Value;
#ifndef _ASSUAN_IN_GPGME
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 MT safe */
}
#endif
if (pipe (rp) < 0)
return ASSUAN_General_Error;
if (pipe (wp) < 0)
{
close (rp[0]);
close (rp[1]);
return ASSUAN_General_Error;
}
err = _assuan_new_context (ctx);
if (err)
{
close (rp[0]);
close (rp[1]);
close (wp[0]);
close (wp[1]);
return err;
}
(*ctx)->pipe_mode = 1;
(*ctx)->inbound.fd = rp[0]; /* Our inbound is read end of read pipe. */
(*ctx)->outbound.fd = wp[1]; /* Our outbound is write end of write pipe. */
(*ctx)->deinit_handler = do_deinit;
(*ctx)->finish_handler = do_finish;
(*ctx)->pid = fork ();
if ((*ctx)->pid < 0)
{
close (rp[0]);
close (rp[1]);
close (wp[0]);
close (wp[1]);
_assuan_release_context (*ctx);
return ASSUAN_General_Error;
}
if ((*ctx)->pid == 0)
{
int i, n;
char errbuf[512];
int *fdp;
/* Dup handles to stdin/stdout. */
if (rp[1] != STDOUT_FILENO)
{
if (dup2 (rp[1], STDOUT_FILENO) == -1)
{
LOG ("dup2 failed in child: %s\n", strerror (errno));
_exit (4);
}
}
if (wp[0] != STDIN_FILENO)
{
if (dup2 (wp[0], STDIN_FILENO) == -1)
{
LOG ("dup2 failed in child: %s\n", strerror (errno));
_exit (4);
}
}
/* Dup stderr to /dev/null unless it is in the list of FDs to be
passed to the child. */
fdp = fd_child_list;
if (fdp)
{
for (; *fdp != -1 && *fdp != STDERR_FILENO; fdp++)
;
}
if (!fdp || *fdp == -1)
{
int fd = open ("/dev/null", O_WRONLY);
if (fd == -1)
{
LOG ("can't open `/dev/null': %s\n", strerror (errno));
_exit (4);
}
if (dup2 (fd, STDERR_FILENO) == -1)
{
LOG ("dup2(dev/null, 2) failed: %s\n", strerror (errno));
_exit (4);
}
}
/* Close all files which will not be duped and are not in the
fd_child_list. */
n = sysconf (_SC_OPEN_MAX);
if (n < 0)
n = MAX_OPEN_FDS;
for (i=0; i < n; i++)
{
if ( i == STDIN_FILENO || i == STDOUT_FILENO || i == STDERR_FILENO)
continue;
fdp = fd_child_list;
if (fdp)
{
while (*fdp != -1 && *fdp != i)
fdp++;
}
if (!(fdp && *fdp != -1))
close(i);
}
errno = 0;
execv (name, argv);
/* oops - use the pipe to tell the parent about it */
snprintf (errbuf, sizeof(errbuf)-1, "ERR %d can't exec `%s': %.50s\n",
ASSUAN_Problem_Starting_Server, name, strerror (errno));
errbuf[sizeof(errbuf)-1] = 0;
writen (1, errbuf, strlen (errbuf));
_exit (4);
}
close (rp[1]);
close (wp[0]);
/* initial handshake */
{
int okay, off;
err = _assuan_read_from_server (*ctx, &okay, &off);
if (err)
LOG ("can't connect server: %s\n", assuan_strerror (err));
else if (okay != 1)
{
LOG ("can't connect server: `%s'\n", (*ctx)->inbound.line);
err = ASSUAN_Connect_Failed;
}
}
if (err)
{
assuan_disconnect (*ctx);
*ctx = NULL;
}
return err;
}