core-admin/vchan/node-select.c
2011-03-08 12:24:47 +01:00

134 lines
3.2 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 "libvchan.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
int libvchan_write_all(struct libvchan *ctrl, char *buf, int size)
{
int written = 0;
int ret;
while (written < size) {
ret = libvchan_write(ctrl, buf + written, size - written);
if (ret <= 0) {
perror("write");
exit(1);
}
written += ret;
}
return size;
}
int write_all(int fd, char *buf, int size)
{
int written = 0;
int ret;
while (written < size) {
ret = write(fd, buf + written, size - written);
if (ret <= 0) {
perror("write");
exit(1);
}
written += ret;
}
return size;
}
void usage()
{
fprintf(stderr, "usage:\n\tnode-select server nodeid\n"
"or\n" "\tnode-select client domainid nodeid\n");
exit(1);
}
#define BUFSIZE 5000
char buf[BUFSIZE];
/**
Simple libvchan application, both client and server.
Both sides may write and read, both from the libvchan and from
stdin/stdout (just like netcat). More code is required to avoid
deadlock when both sides write, and noone reads.
*/
int main(int argc, char **argv)
{
int ret;
int libvchan_fd;
struct libvchan *ctrl = 0;
if (argc < 3)
usage();
if (!strcmp(argv[1], "server"))
ctrl = libvchan_server_init(atoi(argv[2]));
else if (!strcmp(argv[1], "client"))
ctrl = libvchan_client_init(atoi(argv[2]), atoi(argv[3]));
else
usage();
if (!ctrl) {
perror("libvchan_*_init");
exit(1);
}
libvchan_fd = libvchan_fd_for_select(ctrl);
for (;;) {
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(0, &rfds);
FD_SET(libvchan_fd, &rfds);
// libvchan_prepare_to_select(ctrl);
ret = select(libvchan_fd + 1, &rfds, NULL, NULL, NULL);
if (ret < 0) {
perror("select");
exit(1);
}
if (libvchan_is_eof(ctrl))
exit(0);
if (FD_ISSET(libvchan_fd, &rfds))
// we don't care about the result, but we need to do the read to
// clear libvchan_fd pendind state
libvchan_wait(ctrl);
while (libvchan_data_ready(ctrl) > 0) {
ret = libvchan_read(ctrl, buf, BUFSIZE);
if (ret < 0)
exit(0);
write_all(1, buf, ret);
}
if (FD_ISSET(0, &rfds)) {
ret = read(0, buf, BUFSIZE);
if (ret == 0) {
libvchan_close(ctrl);
exit(0);
}
if (ret < 0) {
perror("read 0");
exit(1);
}
// libvchan_write_all can block; so if both sides write a lot,
// we can deadlock. Need higher level solution; would libvchan_write be ok ?
libvchan_write_all(ctrl, buf, ret);
}
}
}