qubes-linux-utils/qrexec-lib/txrx-vchan.c
2017-12-15 20:20:15 +01:00

106 lines
2.7 KiB
C

/*
* The Qubes OS Project, http://www.qubes-os.org
*
* Copyright (C) 2010 Rafal Wojtczuk <rafal@invisiblethingslab.com>
*
* This program 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.
*
* This program 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <errno.h>
#include <sys/select.h>
#include <libvchan.h>
int wait_for_vchan_or_argfd_once(libvchan_t *ctrl, int max, fd_set * rdset, fd_set * wrset)
{
int vfd, ret;
struct timespec tv = { 1, 100000000 };
sigset_t empty_set;
sigemptyset(&empty_set);
vfd = libvchan_fd_for_select(ctrl);
FD_SET(vfd, rdset);
if (vfd > max)
max = vfd;
max++;
ret = pselect(max, rdset, wrset, NULL, &tv, &empty_set);
if (ret < 0) {
if (errno != EINTR) {
perror("select");
exit(1);
} else {
FD_ZERO(rdset);
FD_ZERO(wrset);
fprintf(stderr, "eintr\n");
return 1;
}
}
if (!libvchan_is_open(ctrl)) {
fprintf(stderr, "libvchan_is_eof\n");
exit(0);
}
if (FD_ISSET(vfd, rdset))
// the following will never block; we need to do this to
// clear libvchan_fd pending state
libvchan_wait(ctrl);
if (libvchan_data_ready(ctrl))
return 1;
return ret;
}
void wait_for_vchan_or_argfd(libvchan_t *ctrl, int max, fd_set * rdset, fd_set * wrset)
{
fd_set r = *rdset, w = *wrset;
do {
*rdset = r;
*wrset = w;
}
while (wait_for_vchan_or_argfd_once(ctrl, max, rdset, wrset) == 0);
}
int write_vchan_all(libvchan_t *vchan, const void *data, size_t size) {
size_t pos;
int ret;
pos = 0;
while (pos < size) {
ret = libvchan_write(vchan, data+pos, size-pos);
if (ret < 0)
return 0;
pos += ret;
}
return 1;
}
int read_vchan_all(libvchan_t *vchan, void *data, size_t size) {
size_t pos;
int ret;
pos = 0;
while (pos < size) {
ret = libvchan_read(vchan, data+pos, size-pos);
if (ret < 0)
return 0;
pos += ret;
}
return 1;
}