/* * 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; }
