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libssh/examples/sshnetcat.c
2013-07-23 10:44:51 +02:00

255 строки
5.6 KiB
C

/*
Copyright 2010 Aris Adamantiadis
This file is part of the SSH Library
You are free to copy this file, modify it in any way, consider it being public
domain. This does not apply to the rest of the library though, but it is
allowed to cut-and-paste working code from this file to any license of
program.
The goal is to show the API in action. It's not a reference on how terminal
clients must be made or how a client should react.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_TERMIOS_H
#include <termios.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <sys/select.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <libssh/callbacks.h>
#include <libssh/libssh.h>
#include <libssh/sftp.h>
#include <fcntl.h>
#include "examples_common.h"
char *host;
const char *desthost="localhost";
const char *port="22";
#ifdef WITH_PCAP
#include <libssh/pcap.h>
char *pcap_file=NULL;
#endif
static void usage(){
fprintf(stderr,"Usage : sshnetcat [user@]host forwarded_host forwarded_port\n");
exit(1);
}
static int opts(int argc, char **argv){
int i;
while((i=getopt(argc,argv,"P:"))!=-1){
switch(i){
#ifdef WITH_PCAP
case 'P':
pcap_file=optarg;
break;
#endif
default:
fprintf(stderr,"unknown option %c\n",optopt);
usage();
}
}
if(optind < argc)
host=argv[optind++];
if(optind < argc)
desthost=argv[optind++];
if(optind < argc)
port=argv[optind++];
if(host==NULL)
usage();
return 0;
}
static void select_loop(ssh_session session,ssh_channel channel){
fd_set fds;
struct timeval timeout;
char buffer[4096];
/* channels will be set to the channels to poll.
* outchannels will contain the result of the poll
*/
ssh_channel channels[2], outchannels[2];
int lus;
int eof=0;
int maxfd;
int ret;
while(channel){
do{
FD_ZERO(&fds);
if(!eof)
FD_SET(0,&fds);
timeout.tv_sec=30;
timeout.tv_usec=0;
FD_SET(ssh_get_fd(session),&fds);
maxfd=ssh_get_fd(session)+1;
channels[0]=channel; // set the first channel we want to read from
channels[1]=NULL;
ret=ssh_select(channels,outchannels,maxfd,&fds,&timeout);
if(ret==EINTR)
continue;
if(FD_ISSET(0,&fds)){
lus=read(0,buffer,sizeof(buffer));
if(lus)
channel_write(channel,buffer,lus);
else {
eof=1;
channel_send_eof(channel);
}
}
if(channel && channel_is_closed(channel)){
channel_free(channel);
channel=NULL;
channels[0]=NULL;
}
if(outchannels[0]){
while(channel && channel_is_open(channel) && channel_poll(channel,0)){
lus=channel_read(channel,buffer,sizeof(buffer),0);
if(lus==-1){
fprintf(stderr, "Error reading channel: %s\n",
ssh_get_error(session));
return;
}
if(lus==0){
channel_free(channel);
channel=channels[0]=NULL;
} else {
ret = write(1, buffer, lus);
if (ret < 0) {
fprintf(stderr, "Error writing to stdin: %s",
strerror(errno));
return;
}
}
}
while(channel && channel_is_open(channel) && channel_poll(channel,1)){ /* stderr */
lus=channel_read(channel,buffer,sizeof(buffer),1);
if(lus==-1){
fprintf(stderr, "Error reading channel: %s\n",
ssh_get_error(session));
return;
}
if(lus==0){
channel_free(channel);
channel=channels[0]=NULL;
} else
ret = write(2, buffer, lus);
if (ret < 0) {
fprintf(stderr, "Error writing to stderr: %s",
strerror(errno));
return;
}
}
}
if(channel && channel_is_closed(channel)){
channel_free(channel);
channel=NULL;
}
} while (ret==EINTR || ret==SSH_EINTR);
}
}
static void forwarding(ssh_session session){
ssh_channel channel;
int r;
channel=channel_new(session);
r=channel_open_forward(channel,desthost,atoi(port),"localhost",22);
if(r<0) {
printf("error forwarding port : %s\n",ssh_get_error(session));
return;
}
select_loop(session,channel);
}
static int client(ssh_session session){
int auth=0;
char *banner;
int state;
if (ssh_options_set(session, SSH_OPTIONS_HOST ,host) < 0)
return -1;
ssh_options_parse_config(session, NULL);
if(ssh_connect(session)){
fprintf(stderr,"Connection failed : %s\n",ssh_get_error(session));
return -1;
}
state=verify_knownhost(session);
if (state != 0)
return -1;
ssh_userauth_none(session, NULL);
banner=ssh_get_issue_banner(session);
if(banner){
printf("%s\n",banner);
free(banner);
}
auth=authenticate_console(session);
if(auth != SSH_AUTH_SUCCESS){
return -1;
}
forwarding(session);
return 0;
}
#ifdef WITH_PCAP
ssh_pcap_file pcap;
void set_pcap(ssh_session session);
void set_pcap(ssh_session session){
if(!pcap_file)
return;
pcap=ssh_pcap_file_new();
if(ssh_pcap_file_open(pcap,pcap_file) == SSH_ERROR){
printf("Error opening pcap file\n");
ssh_pcap_file_free(pcap);
pcap=NULL;
return;
}
ssh_set_pcap_file(session,pcap);
}
void cleanup_pcap(void);
void cleanup_pcap(){
ssh_pcap_file_free(pcap);
pcap=NULL;
}
#endif
int main(int argc, char **argv){
ssh_session session;
session = ssh_new();
if(ssh_options_getopt(session, &argc, argv)) {
fprintf(stderr, "error parsing command line :%s\n",
ssh_get_error(session));
usage();
}
opts(argc,argv);
#ifdef WITH_PCAP
set_pcap(session);
#endif
client(session);
ssh_disconnect(session);
ssh_free(session);
#ifdef WITH_PCAP
cleanup_pcap();
#endif
ssh_finalize();
return 0;
}