example/ssh2_exec.c - third_party/libssh2 - Git at Google

 /*
  * 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)
         fprintf(stderr, "\nGot signal: %s\n", exitsignal);
     else
         fprintf(stderr, "\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;
 }
	/*
	* 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)
	fprintf(stderr, "\nGot signal: %s\n", exitsignal);
	else
	fprintf(stderr, "\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;
	}