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

 /*
  * Sample showing how to do SCP transfers in a non-blocking manner.
  *
  * The sample code has default values for host name, user name, password
  * and path to copy, but you can specify them on the command line like:
  *
  * "scp_nonblock 192.168.0.1 user password /tmp/secrets"
  */

 #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
 #ifdef HAVE_SYS_TIME_H
 # include <sys/time.h>
 #endif

 #include <sys/types.h>
 #include <fcntl.h>
 #include <errno.h>
 #include <stdio.h>
 #include <ctype.h>

 /* diff in ms */
 static long tvdiff(struct timeval newer, struct timeval older)
 {
   return (newer.tv_sec-older.tv_sec)*1000+
       (newer.tv_usec-older.tv_usec)/1000;
 }

 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[])
 {
     unsigned long hostaddr;
     int sock, i, auth_pw = 1;
     struct sockaddr_in sin;
     const char *fingerprint;
     LIBSSH2_SESSION *session;
     LIBSSH2_CHANNEL *channel;
     const char *username="username";
     const char *password="password";
     const char *scppath="/tmp/TEST";
     struct stat fileinfo;
     struct timeval start;
     struct timeval end;
     int rc;
     int total = 0;
     long time_ms;
     int spin = 0;
     off_t got=0;

 #ifdef WIN32
     WSADATA wsadata;

     WSAStartup(MAKEWORD(2,0), &wsadata);
 #endif

     if (argc > 1) {
         hostaddr = inet_addr(argv[1]);
     } else {
         hostaddr = htonl(0x7F000001);
     }
     if (argc > 2) {
         username = argv[2];
     }
     if (argc > 3) {
         password = argv[3];
     }
     if (argc > 4) {
         scppath = argv[4];
     }

     rc = libssh2_init (0);
     if (rc != 0) {
         fprintf (stderr, "libssh2 initialization failed (%d)\n", rc);
         return 1;
     }

     /* 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;

     /* Since we have set non-blocking, tell libssh2 we are non-blocking */
     libssh2_session_set_blocking(session, 0);

     gettimeofday(&start, NULL);

     /* ... 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;
     }

     /* At this point we havn't yet authenticated.  The first thing to do
         * is check the hostkey's fingerprint against our known hosts Your app
         * may have it hard coded, may go to a file, may present it to the
         * user, that's your call
         */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
     fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
         fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
     fprintf(stderr, "\n");

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

 #if 0
     libssh2_trace(session, LIBSSH2_TRACE_CONN);
 #endif

     /* Request a file via SCP */
     fprintf(stderr, "libssh2_scp_recv()!\n");
     do {
         channel = libssh2_scp_recv(session, scppath, &fileinfo);

         if (!channel) {
             if(libssh2_session_last_errno(session) != LIBSSH2_ERROR_EAGAIN) {
                 char *err_msg;

                 libssh2_session_last_error(session, &err_msg, NULL, 0);
                 fprintf(stderr, "%s\n", err_msg);
                 goto shutdown;
             }
             else {
                 fprintf(stderr, "libssh2_scp_recv() spin\n");
                 waitsocket(sock, session);
             }
         }
     } while (!channel);
     fprintf(stderr, "libssh2_scp_recv() is done, now receive data!\n");

     while(got < fileinfo.st_size) {
         char mem[1024*24];
         int rc;

         do {
             int amount=sizeof(mem);

             if ((fileinfo.st_size -got) < amount) {
                 amount = fileinfo.st_size - got;
             }

             /* loop until we block */
             rc = libssh2_channel_read(channel, mem, amount);
             if (rc > 0) {
                 write(1, mem, rc);
                 got += rc;
                 total += rc;
             }
         } while (rc > 0);

         if ((rc == LIBSSH2_ERROR_EAGAIN) && (got < fileinfo.st_size)) {
             /* this is due to blocking that would occur otherwise
             so we loop on this condition */

             spin++;
             waitsocket(sock, session); /* now we wait */
             continue;
         }
         break;
     }

     gettimeofday(&end, NULL);

     time_ms = tvdiff(end, start);
     fprintf(stderr, "Got %d bytes in %ld ms = %.1f bytes/sec spin: %d\n", total,
            time_ms, total/(time_ms/1000.0), spin );

     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 do SCP transfers in a non-blocking manner.
	*
	* The sample code has default values for host name, user name, password
	* and path to copy, but you can specify them on the command line like:
	*
	* "scp_nonblock 192.168.0.1 user password /tmp/secrets"
	*/

	#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
	#ifdef HAVE_SYS_TIME_H
	# include <sys/time.h>
	#endif

	#include <sys/types.h>
	#include <fcntl.h>
	#include <errno.h>
	#include <stdio.h>
	#include <ctype.h>

	/* diff in ms */
	static long tvdiff(struct timeval newer, struct timeval older)
	{
	return (newer.tv_sec-older.tv_sec)*1000+
	(newer.tv_usec-older.tv_usec)/1000;
	}

	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[])
	{
	unsigned long hostaddr;
	int sock, i, auth_pw = 1;
	struct sockaddr_in sin;
	const char *fingerprint;
	LIBSSH2_SESSION *session;
	LIBSSH2_CHANNEL *channel;
	const char *username="username";
	const char *password="password";
	const char *scppath="/tmp/TEST";
	struct stat fileinfo;
	struct timeval start;
	struct timeval end;
	int rc;
	int total = 0;
	long time_ms;
	int spin = 0;
	off_t got=0;

	#ifdef WIN32
	WSADATA wsadata;

	WSAStartup(MAKEWORD(2,0), &wsadata);
	#endif

	if (argc > 1) {
	hostaddr = inet_addr(argv[1]);
	} else {
	hostaddr = htonl(0x7F000001);
	}
	if (argc > 2) {
	username = argv[2];
	}
	if (argc > 3) {
	password = argv[3];
	}
	if (argc > 4) {
	scppath = argv[4];
	}

	rc = libssh2_init (0);
	if (rc != 0) {
	fprintf (stderr, "libssh2 initialization failed (%d)\n", rc);
	return 1;
	}

	/* 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;

	/* Since we have set non-blocking, tell libssh2 we are non-blocking */
	libssh2_session_set_blocking(session, 0);

	gettimeofday(&start, NULL);

	/* ... 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;
	}

	/* At this point we havn't yet authenticated. The first thing to do
	* is check the hostkey's fingerprint against our known hosts Your app
	* may have it hard coded, may go to a file, may present it to the
	* user, that's your call
	*/
	fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
	fprintf(stderr, "Fingerprint: ");
	for(i = 0; i < 20; i++) {
	fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
	}
	fprintf(stderr, "\n");

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

	#if 0
	libssh2_trace(session, LIBSSH2_TRACE_CONN);
	#endif

	/* Request a file via SCP */
	fprintf(stderr, "libssh2_scp_recv()!\n");
	do {
	channel = libssh2_scp_recv(session, scppath, &fileinfo);

	if (!channel) {
	if(libssh2_session_last_errno(session) != LIBSSH2_ERROR_EAGAIN) {
	char *err_msg;

	libssh2_session_last_error(session, &err_msg, NULL, 0);
	fprintf(stderr, "%s\n", err_msg);
	goto shutdown;
	}
	else {
	fprintf(stderr, "libssh2_scp_recv() spin\n");
	waitsocket(sock, session);
	}
	}
	} while (!channel);
	fprintf(stderr, "libssh2_scp_recv() is done, now receive data!\n");

	while(got < fileinfo.st_size) {
	char mem[1024*24];
	int rc;

	do {
	int amount=sizeof(mem);

	if ((fileinfo.st_size -got) < amount) {
	amount = fileinfo.st_size - got;
	}

	/* loop until we block */
	rc = libssh2_channel_read(channel, mem, amount);
	if (rc > 0) {
	write(1, mem, rc);
	got += rc;
	total += rc;
	}
	} while (rc > 0);

	if ((rc == LIBSSH2_ERROR_EAGAIN) && (got < fileinfo.st_size)) {
	/* this is due to blocking that would occur otherwise
	so we loop on this condition */

	spin++;
	waitsocket(sock, session); /* now we wait */
	continue;
	}
	break;
	}

	gettimeofday(&end, NULL);

	time_ms = tvdiff(end, start);
	fprintf(stderr, "Got %d bytes in %ld ms = %.1f bytes/sec spin: %d\n", total,
	time_ms, total/(time_ms/1000.0), spin );

	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;
	}