example/ssh2_echo.c - third_party/libssh2 - Git at Google

 /*
  * Run it like this:
  *
  * $ ./ssh2_echo 127.0.0.1 user password
  *
  * The code sends a 'cat' command, and then writes a lot of data to it only to
  * check that reading the returned data sums up to the same amount.
  *
  */

 #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;
 }

 #define BUFSIZE 32000

 int main(int argc, char *argv[])
 {
     const char *hostname = "127.0.0.1";
     const char *commandline = "cat";
     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 = 0;
     char *exitsignal=(char *)"none";
     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];
     }

     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;
         int check = libssh2_knownhost_checkp(nh, hostname, 22,
                                              fingerprint, len,
                                              LIBSSH2_KNOWNHOST_TYPE_PLAIN|
                                              LIBSSH2_KNOWNHOST_KEYENC_RAW,
                                              &host);

         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");
             exit(1);
         }
     }

     libssh2_trace(session, LIBSSH2_TRACE_SOCKET);

     /* 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, "exec error\n");
         exit( 1 );
     }
     else {
         LIBSSH2_POLLFD *fds = NULL;
         int running = 1;
         int bufsize = BUFSIZE;
         char buffer[BUFSIZE];
         int totsize = 1500000;
         int totwritten = 0;
         int totread = 0;
         int partials = 0;
         int rereads = 0;
         int rewrites = 0;
         int i;

         for (i = 0; i < BUFSIZE; i++)
             buffer[i] = 'A';

         if ((fds = malloc (sizeof (LIBSSH2_POLLFD))) == NULL) {
             fprintf(stderr, "malloc failed\n");
             exit(1);
         }

         fds[0].type = LIBSSH2_POLLFD_CHANNEL;
         fds[0].fd.channel = channel;
         fds[0].events = LIBSSH2_POLLFD_POLLIN | LIBSSH2_POLLFD_POLLOUT;

         do {
             int rc = (libssh2_poll(fds, 1, 10));
             int act = 0;

             if (rc < 1)
                 continue;

             if (fds[0].revents & LIBSSH2_POLLFD_POLLIN) {
                 int n = libssh2_channel_read(channel, buffer, sizeof(buffer));
                 act++;

                 if (n == LIBSSH2_ERROR_EAGAIN) {
                     rereads++;
                     fprintf(stderr, "will read again\n");
                 }
                 else if (n < 0) {
                     fprintf(stderr, "read failed\n");
                     exit(1);
                 }
                 else {
                     totread += n;
                     fprintf(stderr, "read %d bytes (%d in total)\n",
                             n, totread);
                 }
             }

             if (fds[0].revents & LIBSSH2_POLLFD_POLLOUT) {
                 act++;

                 if (totwritten < totsize) {
                     /* we have not written all data yet */
                     int left = totsize - totwritten;
                     int size = (left < bufsize) ? left : bufsize;
                     int n = libssh2_channel_write_ex(channel, 0, buffer, size);

                     if (n == LIBSSH2_ERROR_EAGAIN) {
                         rewrites++;
                         fprintf(stderr, "will write again\n");
                     }
                     else if (n < 0) {
                         fprintf(stderr, "write failed\n");
                         exit(1);
                     }
                     else {
                         totwritten += n;
                         fprintf(stderr, "wrote %d bytes (%d in total)",
                                 n, totwritten);
                         if (left >= bufsize && n != bufsize) {
                             partials++;
                             fprintf(stderr, " PARTIAL");
                         }
                         fprintf(stderr, "\n");
                     }
                 } else {
                     /* all data written, send EOF */
                     rc = libssh2_channel_send_eof(channel);

                     if (rc == LIBSSH2_ERROR_EAGAIN) {
                         fprintf(stderr, "will send eof again\n");
                     }
                     else if (rc < 0) {
                         fprintf(stderr, "send eof failed\n");
                         exit(1);
                     }
                     else {
                         fprintf(stderr, "sent eof\n");
                         /* we're done writing, stop listening for OUT events */
                         fds[0].events &= ~LIBSSH2_POLLFD_POLLOUT;
                     }
                 }
             }

             if (fds[0].revents & LIBSSH2_POLLFD_CHANNEL_CLOSED) {
                 if (!act) /* don't leave loop until we have read all data */
                     running = 0;
             }
         } while(running);

         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);

         libssh2_channel_free(channel);
         channel = NULL;

         fprintf(stderr, "\nrereads: %d rewrites: %d totwritten %d\n",
                 rereads, rewrites, totwritten);

         if (totwritten != totread) {
             fprintf(stderr, "\n*** FAIL bytes written: %d bytes "
                     "read: %d ***\n", totwritten, totread);
             exit(1);
         }
     }

     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 exitcode;
 }
	/*
	* Run it like this:
	*
	* $ ./ssh2_echo 127.0.0.1 user password
	*
	* The code sends a 'cat' command, and then writes a lot of data to it only to
	* check that reading the returned data sums up to the same amount.
	*
	*/

	#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;
	}

	#define BUFSIZE 32000

	int main(int argc, char *argv[])
	{
	const char *hostname = "127.0.0.1";
	const char *commandline = "cat";
	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 = 0;
	char exitsignal=(char )"none";
	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];
	}

	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;
	int check = libssh2_knownhost_checkp(nh, hostname, 22,
	fingerprint, len,
	LIBSSH2_KNOWNHOST_TYPE_PLAIN\|
	LIBSSH2_KNOWNHOST_KEYENC_RAW,
	&host);

	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");
	exit(1);
	}
	}

	libssh2_trace(session, LIBSSH2_TRACE_SOCKET);

	/* 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, "exec error\n");
	exit( 1 );
	}
	else {
	LIBSSH2_POLLFD *fds = NULL;
	int running = 1;
	int bufsize = BUFSIZE;
	char buffer[BUFSIZE];
	int totsize = 1500000;
	int totwritten = 0;
	int totread = 0;
	int partials = 0;
	int rereads = 0;
	int rewrites = 0;
	int i;

	for (i = 0; i < BUFSIZE; i++)
	buffer[i] = 'A';

	if ((fds = malloc (sizeof (LIBSSH2_POLLFD))) == NULL) {
	fprintf(stderr, "malloc failed\n");
	exit(1);
	}

	fds[0].type = LIBSSH2_POLLFD_CHANNEL;
	fds[0].fd.channel = channel;
	fds[0].events = LIBSSH2_POLLFD_POLLIN \| LIBSSH2_POLLFD_POLLOUT;

	do {
	int rc = (libssh2_poll(fds, 1, 10));
	int act = 0;

	if (rc < 1)
	continue;

	if (fds[0].revents & LIBSSH2_POLLFD_POLLIN) {
	int n = libssh2_channel_read(channel, buffer, sizeof(buffer));
	act++;

	if (n == LIBSSH2_ERROR_EAGAIN) {
	rereads++;
	fprintf(stderr, "will read again\n");
	}
	else if (n < 0) {
	fprintf(stderr, "read failed\n");
	exit(1);
	}
	else {
	totread += n;
	fprintf(stderr, "read %d bytes (%d in total)\n",
	n, totread);
	}
	}

	if (fds[0].revents & LIBSSH2_POLLFD_POLLOUT) {
	act++;

	if (totwritten < totsize) {
	/* we have not written all data yet */
	int left = totsize - totwritten;
	int size = (left < bufsize) ? left : bufsize;
	int n = libssh2_channel_write_ex(channel, 0, buffer, size);

	if (n == LIBSSH2_ERROR_EAGAIN) {
	rewrites++;
	fprintf(stderr, "will write again\n");
	}
	else if (n < 0) {
	fprintf(stderr, "write failed\n");
	exit(1);
	}
	else {
	totwritten += n;
	fprintf(stderr, "wrote %d bytes (%d in total)",
	n, totwritten);
	if (left >= bufsize && n != bufsize) {
	partials++;
	fprintf(stderr, " PARTIAL");
	}
	fprintf(stderr, "\n");
	}
	} else {
	/* all data written, send EOF */
	rc = libssh2_channel_send_eof(channel);

	if (rc == LIBSSH2_ERROR_EAGAIN) {
	fprintf(stderr, "will send eof again\n");
	}
	else if (rc < 0) {
	fprintf(stderr, "send eof failed\n");
	exit(1);
	}
	else {
	fprintf(stderr, "sent eof\n");
	/* we're done writing, stop listening for OUT events */
	fds[0].events &= ~LIBSSH2_POLLFD_POLLOUT;
	}
	}
	}

	if (fds[0].revents & LIBSSH2_POLLFD_CHANNEL_CLOSED) {
	if (!act) /* don't leave loop until we have read all data */
	running = 0;
	}
	} while(running);

	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);

	libssh2_channel_free(channel);
	channel = NULL;

	fprintf(stderr, "\nrereads: %d rewrites: %d totwritten %d\n",
	rereads, rewrites, totwritten);

	if (totwritten != totread) {
	fprintf(stderr, "\n*** FAIL bytes written: %d bytes "
	"read: %d ***\n", totwritten, totread);
	exit(1);
	}
	}

	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 exitcode;
	}