/*


Sample showing how to use libssh2 to execute a command remotely.
*
The sample code has fixed values for host name, user name, password
and command to run.
*
Run it like this:
*
$ ./ssh2_exec 127.0.0.1 user password "uptime"
/

include "libssh2_config.h"
include <libssh2.h>
ifdef HAVE_WINSOCK2_H
include <winsock2.h>
endif
ifdef HAVE_SYS_SOCKET_H
include <sys/socket.h>
endif
ifdef HAVE_NETINET_IN_H
include <netinet/in.h>
endif
ifdef HAVE_SYS_SELECT_H
include <sys/select.h>
endif
ifdef HAVE_UNISTD_H
include <unistd.h>
endif
ifdef HAVE_ARPA_INET_H
include <arpa/inet.h>
endif
include <sys/time.h>
include <sys/types.h>
include <stdlib.h>
include <fcntl.h>
include <errno.h>
include <stdio.h>
include <ctype.h>
static int waitsocket(int socket_fd, LIBSSH2_SESSION session)
{
    struct timeval timeout;
    int rc;
    fd_set fd;
    fd_set writefd = NULL;
    fd_set *readfd = NULL;
    int dir;

timeout.tv_sec = 10;
timeout.tv_usec = 0;

FD_ZERO(&fd);

FD_SET(socket_fd, &fd);

/* now make sure we wait in the correct direction */
dir = libssh2_session_block_directions(session);


if(dir & LIBSSH2_SESSION_BLOCK_INBOUND)
    readfd = &fd;

if(dir & LIBSSH2_SESSION_BLOCK_OUTBOUND)
    writefd = &fd;

rc = select(socket_fd + 1, readfd, writefd, NULL, &timeout);

return rc;

}
int main(int argc, char argv[])
{
    const char hostname = "127.0.0.1";
    const char commandline = "uptime";
    const char username    = "user";
    const char password    = "password";
    unsigned long hostaddr;
    int sock;
    struct sockaddr_in sin;
    const char fingerprint;
    LIBSSH2_SESSION session;
    LIBSSH2_CHANNEL channel;
    int rc;
    int exitcode;
    char exitsignal=(char )"none";
    int bytecount = 0;
    size_t len;
    LIBSSH2_KNOWNHOSTS *nh;
    int type;
ifdef WIN32

WSADATA wsadata;
WSAStartup(MAKEWORD(2,0), &wsadata);

endif

if (argc > 1)
    /* must be ip address only */
    hostname = argv[1];

if (argc > 2) {
    username = argv[2];
}
if (argc > 3) {
    password = argv[3];
}
if (argc > 4) {
    commandline = argv[4];
}

rc = libssh2_init (0);

if (rc != 0) {
    fprintf (stderr, "libssh2 initialization failed (%d)\n", rc);
    return 1;
}

hostaddr = inet_addr(hostname);

/* Ultra basic "connect to port 22 on localhost"
 * Your code is responsible for creating the socket establishing the
 * connection
 */
sock = socket(AF_INET, SOCK_STREAM, 0);

sin.sin_family = AF_INET;
sin.sin_port = htons(22);
sin.sin_addr.s_addr = hostaddr;
if (connect(sock, (struct sockaddr*)(&sin),
            sizeof(struct sockaddr_in)) != 0) {
    fprintf(stderr, "failed to connect!\n");
    return -1;
}

/* Create a session instance */
session = libssh2_session_init();

if (!session)
    return -1;

/* tell libssh2 we want it all done non-blocking */
libssh2_session_set_blocking(session, 0);


/* ... start it up. This will trade welcome banners, exchange keys,
 * and setup crypto, compression, and MAC layers
 */
while ((rc = libssh2_session_handshake(session, sock)) ==

       LIBSSH2_ERROR_EAGAIN);
if (rc) {
    fprintf(stderr, "Failure establishing SSH session: %d\n", rc);
    return -1;
}

nh = libssh2_knownhost_init(session);

if(!nh) {
    /* eeek, do cleanup here */
    return 2;
}

/* read all hosts from here */
libssh2_knownhost_readfile(nh, "known_hosts",

                           LIBSSH2_KNOWNHOST_FILE_OPENSSH);

/* store all known hosts to here */
libssh2_knownhost_writefile(nh, "dumpfile",

                            LIBSSH2_KNOWNHOST_FILE_OPENSSH);

fingerprint = libssh2_session_hostkey(session, &len, &type);

if(fingerprint) {
    struct libssh2_knownhost *host;

if LIBSSH2_VERSION_NUM >= 0x010206

    /* introduced in 1.2.6 */
    int check = libssh2_knownhost_checkp(nh, hostname, 22,

                                         fingerprint, len,
                                         LIBSSH2_KNOWNHOST_TYPE_PLAIN|
                                         LIBSSH2_KNOWNHOST_KEYENC_RAW,
                                         &host);

else

    /* 1.2.5 or older */
    int check = libssh2_knownhost_check(nh, hostname,

                                        fingerprint, len,
                                        LIBSSH2_KNOWNHOST_TYPE_PLAIN|
                                        LIBSSH2_KNOWNHOST_KEYENC_RAW,
                                        &host);

endif

    fprintf(stderr, "Host check: %d, key: %s\n", check,
            (check <= LIBSSH2_KNOWNHOST_CHECK_MISMATCH)?
            host->key:"<none>");

    /*****
     * At this point, we could verify that 'check' tells us the key is
     * fine or bail out.
     *****/
}
else {
    /* eeek, do cleanup here */
    return 3;
}
libssh2_knownhost_free(nh);


if ( strlen(password) != 0 ) {
    /* We could authenticate via password */
    while ((rc = libssh2_userauth_password(session, username, password)) ==

           LIBSSH2_ERROR_EAGAIN);
    if (rc) {
        fprintf(stderr, "Authentication by password failed.\n");
        goto shutdown;
    }
}
else {
    /* Or by public key */
    while ((rc = libssh2_userauth_publickey_fromfile(session, username,

                                                     "/home/user/"
                                                     ".ssh/id_rsa.pub",
                                                     "/home/user/"
                                                     ".ssh/id_rsa",
                                                     password)) ==
           LIBSSH2_ERROR_EAGAIN);
    if (rc) {
        fprintf(stderr, "\tAuthentication by public key failed\n");
        goto shutdown;
    }
}


if 0

libssh2_trace(session, ~0 );


endif

/* Exec non-blocking on the remove host */
while( (channel = libssh2_channel_open_session(session)) == NULL &&

       libssh2_session_last_error(session,NULL,NULL,0) ==

       LIBSSH2_ERROR_EAGAIN )
{
    waitsocket(sock, session);
}
if( channel == NULL )
{
    fprintf(stderr,"Error\n");
    exit( 1 );
}
while( (rc = libssh2_channel_exec(channel, commandline)) ==

       LIBSSH2_ERROR_EAGAIN )
{
    waitsocket(sock, session);
}
if( rc != 0 )
{
    fprintf(stderr,"Error\n");
    exit( 1 );
}
for( ;; )
{
    /* loop until we block */
    int rc;
    do
    {
        char buffer[0x4000];
        rc = libssh2_channel_read( channel, buffer, sizeof(buffer) );

        if( rc > 0 )
        {
            int i;
            bytecount += rc;
            fprintf(stderr, "We read:\n");
            for( i=0; i < rc; ++i )
                fputc( buffer[i], stderr);
            fprintf(stderr, "\n");
        }
        else {
            if( rc != LIBSSH2_ERROR_EAGAIN )
                /* no need to output this for the EAGAIN case */
                fprintf(stderr, "libssh2_channel_read returned %d\n", rc);
        }
    }
    while( rc > 0 );

    /* this is due to blocking that would occur otherwise so we loop on
       this condition */
    if( rc == LIBSSH2_ERROR_EAGAIN )
    {
        waitsocket(sock, session);
    }
    else
        break;
}
exitcode = 127;
while( (rc = libssh2_channel_close(channel)) == LIBSSH2_ERROR_EAGAIN )

    waitsocket(sock, session);

if( rc == 0 )
{
    exitcode = libssh2_channel_get_exit_status( channel );

    libssh2_channel_get_exit_signal(channel, &exitsignal,

                                    NULL, NULL, NULL, NULL, NULL);
}

if (exitsignal)
    printf("\nGot signal: %s\n", exitsignal);
else
    printf("\nEXIT: %d bytecount: %d\n", exitcode, bytecount);

libssh2_channel_free(channel);

channel = NULL;


shutdown:

libssh2_session_disconnect(session,

                           "Normal Shutdown, Thank you for playing");
libssh2_session_free(session);



ifdef WIN32

closesocket(sock);

else

close(sock);

endif

fprintf(stderr, "all done\n");

libssh2_exit();


return 0;

}</pre>